Its good news for people with neurological conditions
Andrew Fletcher
gravitystudy at hotmail.com
Mon May 31 11:14:04 EST 1999
Hi James
Thank you for responding to my post.
-----Original Message-----
From: Millennial Dragon <james.teo at chch.ox.ac.uk>
Newsgroups: bionet.neuroscience
Date: 31 May 1999 14:57
Subject: Re: Its good news for people with neurological conditions
>Translation: Not a professional scientist nor doctor
Translation: Paid Scientist or Paid Doctor
>Translation: Not peer reviewed
Translation Peer review unavailable
John and Jean Simkins are respected throughout the World for their work in
multiple sclerosis. as for peer review, this appears to be a luxury which
eludes me despite trying to involve many professional people.
At the end of the day does it really matter who one is? All than matters is
what one achieves in this pathetically short existence!
Judge me by what appears on the message board and conclude that there is
either a mass international conspiracy to promote an unknown nobody's
theory, or that the people posting might actually be experiencing what they
post.
>>When the first two people with complete spinal cord injuries raised their
be
>>ds and recovered an unprecedented amount of bodily functions, I thought I
>>had done enough, and even when I helped another five people with the same
>>condition to improve their lives, I was confronted by the usual
closed-shop
>>stone wall attitude in Science and Medicine.
>
>So what you're saying is that what you do is not science and medicine?
Can't remember saying this?
My science is sound repeatable science which may be conducted at infant
level and understood.
>>You have not answered this simple question. Who told you to sleep on a
flat
>>bed? I will answer it for you.
>
>>NO ONE! People sleep flat for no other reason than, because beds are made
>>flat.
>
>Sure, I can live with that: there is no reason, and that sleeping
>upright might have positive effects to general wellbeing, but adding
>pseudoscience does not legitimise it. If sleeping upright is good for
>the health, why don't you just state the facts: "Sleeping upright is
>good for the health, and so far we don't know why"
SEE abstracts below
>>Once it is realised that gravity plays the key roll in circulation of
>>fluids, and that the circulation is a non-living physical force, it
becomes
>>apparent that this circulation has no respect for the vessel that contains
>>it, be it the ocean or a single cell, the circulation exists.
>
>speaks for itself, doesn't it?
Take gravity away and there would be no life on Earth. Only Mankind could
surmise that he is independent of the force of gravity, despite everywhere
one looks life appears to benefit from its influence. The Atlantic conveyor
System operates on the same flow and return system!
>>Next time you take a "P" observe the hot urine as it flows directly to the
>>bottom of the toilet and ponder this.
>>
>>The urine flows to the bottom of the toilet and in order to do so fresh
>>water had to flow up to replace it. (Flow and Return). The urine reached
the
>>bottom of the pan because it contained heavy substances. Therefore it is
>>logical that the urine flowed into the bladder under the same influence.
>>
>>Now ask yourself how the urine became concentrated in the first place?
>
>The counter-current flow mechanism in the cortex and medulla of the
>kidney. The epithelia on the loop of Henle contains all manner of
>ATPases, channels and transporters to accomplish this. Also, the
>aquaporin channels in the collecting duct is involved in regulating
>the concentration of the urine. This is in ANY physiology
>undergraduate textbook; methinks you haven't read any.
Perhaps you would like to explain how the specific gravity of urine drops to
a zero level when you sleep with your head down and your feet up? Yet the
opposite is observed when the bed is inclined. How does that fit with your
text book?
Authors--------Hargens AR.
Institution----- Life Sciences Division, NASA Ames Research Centre, Moffet
Field, California 94035-1000.
Title------------Recent bed rest results and countermeasures development at
NASA. [review]
Source---------Acta Physiologica Scandinavica. Supplementum. 616:103-14,
1994
Abstract-------Bedrest studies of normal subjects provide opportunities to
understand physiologic responses to supine posture and inactivity.
Furthermore, head down tilt has been a valuable procedure to investigate
adaptation to microgravity and development of countermeasures to maintain
the health and well being of humans during space flight. Recent bedrest
experiments at NASA have ranged in duration from a few hours to 17 weeks.
Acute studies of 6 degrees head down tilt indicate that elevation of
capillary blood pressure from 28 to 34 mm Hg and increased capillary
perfusion in tissues of the head cause facial and intracranial oedema.
Intracranial pressure increases from 2 to 17 mm Hg going from upright
posture to 6 degrees head down tilt. Microvessels of the head have a low
capacity to constrict and diminish local perfusion. Elevation of blood and
tissue fluid pressures /floe in the head may also explain the
higher-head-ward bone density associated with prolonged head down tilt.
These mechanistic studies of head down tilt along with a better
understanding of the relative stresses involved with upright posture and
lower body negative pressure, have facilitated development of suitable
physiologic countermeasures to maintain astronaut health during
microgravity. Presently no exercise hardware is available to provide a blood
pressure gradient from head to feet in space. However, recent studies in our
laboratory suggest that treadmill exercise using a graded lower body
compression suit and 100 mm Hg lower body negative pressure provides
equivalent or greater physiologic stress than similar upright exercise on
Earth. Therefore Exercise within a lower body negative pressure chamber may
provide a cost effective and simple countermeasure to maintain the
cardiovascular and neuro-musculoskeletal systems of astronauts during
long-duration space flights. [references: 47).
Authors-------- Curry K. Casady L.
Institution----- Tampa General Hospital, Florida 33601
Title------------The relationship between extended periods of immobility and
decibuitis ulcer formation in the acutely spinal cordinjured individual.
Source---------Journal of Neuroscience nursing. 24(4):185-9, 1992 Aug.
Abstract-------Several variables may influence the development of decubitis
ulcers during the acute treatment phase following spinal cord injury,
completeness of injury and length of time immobilised. Of these, length of
immobilisation exceeding six hours was associated with subsequent
development of sacral or occipital decubitis ulcer at a significant level
(p= .0094). The presence of a complete injury was associated with an
increased rate of decubitis formation. Results suggest that initial
treatment of acute spinal cord injuries should include the use of pressure
relieving manoeuvres or devices as soon as possible, especially in patients
with anticipated extensive immobilisation. Recognising that risk of
decubitis ulcer formation increases with immobilisation time, the period of
time involved in initial diagnosis and intervention should be kept to a
minimum. This is particularly true in patients with complete spinal
injuries.
Authors--------le Blank A. Shneider V. Spector E. Evans H. Rowe R. Lane
H. Demers L. Lipton A.
Institution----- Department of medicine, Baylor College of Medicine, Houston
TX, USA.
Title------------Calcium absorption, endogenous excretion, and endocrine
changes during and after long term bedrest.
Source---------Bone. 16(4 Supplement):3016-3045, 1995 Apr
Abstract-------Negative calcium balance is a known consequence of bedrest,
and is manifested in elevated urine and faecal calcium (Ca). Elevated faecal
Ca can result from either decreased absorption, increased endogenous faecal
excretion, or both. We measured the Ca absorption and endogenous faecal
excretion in eight healthy male volunteers before and during four months of
bedrest. Dual Isotope (n =A) or single isotope (n = 2 methods in conjunction
with Ca Balance were used to calculate true and net Ca absorption and
endogenous faecal excretion. Stool Ca increased from 797 mg/day (mean intake
991 mg/day) to 911 mg/day during bedrest, whereas urine excretion increased
from 31=/-7% of Ca intake pre-bedrest to 24 =/- 2% during bedrest, (p <0.05)
and returned toward pre-bedrest values within 5-6 weeks following
reambulation. Endogenous faecal excretion did not change significantly, and
therefore, most of the increased faecal Ca resulted from changes in
absorption. However, in one individual, endogenous faecal Ca excretion was
the major contributor to Ca loss. Ionised Ca and pyridinium cross links
increased and 1,25 (OH)2 vitamin D decreased during bedrest, similar to the
decrease in Ca absorption; parathyroid hormone (PTH), calcitonin, serum
albumin, phosphorus, and total serum Ca were unchanged. Although alkaline
phosphatase, osteocalcin, and PTH were unchanged during bedrest, they were
elevated during
reambulation. These changes accompanied by increased Ca absorption and
balance and decreased ionised and total serum Ca suggest a rebound in bone
formation following immobilisation.
Authors--------Taylor SB. Shelton JE.
Institution----- Department of physical Medicine, Norfolk 23507, USA.
Title------------Caloric requirements of a spastic immobile cerebral palsy
patient: a case report
Source---------Archives of Physical Medicine and Rehabilitation. 76 (3)
:281-3, 1995 Mar.
Abstract-------This article documents the reduced caloric requirements for a
spastic, immobile, cerebral palsy patient. We report an 11 year old
immobile, spastic, quadriplegic patient, who remained obese despite
receiving less than one half of the recommended basal caloric requirements
for age. Basal metabolic rate was determined by indirect calorimetry using a
sensor medics 2900 instrument. Standard reference sources indicate that an
able bodied 11 year old child of comparable height requires 1,493 kcal/d
for support of basal metabolic functions. Our patient was followed for 8
weeks on reduced calories and assessed for adequacy of diet by nitrogen
balance studies and other appropriate parameters. Our data suggests that a
sub set of severely impaired children with cerebral palsy may require much
less in total kilocalories per day for nutitional support than previous
studies would indicate.
Authors-------Dittmer D K.
Institution----- Department of Physical Medicine and rehabilitation,
University of Western Ontario, London,
Title------------Complications of Immobilisation and bed rest. Part 1:
Musculoskeletal and Cardiovascular complications. [Review]
Source---------Canadian Family Physician. 39:1428-32, 1435-7, 1993 June.
Abstract-------Prolonged bed rest and immobilisation inevitably lead to
complications. Such complications are much easier to prevent than to treat.
Musculoskeletal complications include loss of muscle strength and endurance,
contractures and soft tissue changes, disuse osteoporosis, and degenerative
joint disease. Cardiovascular complications include an increase in heart
rate, decreased cardiac reserve, orthostatic hypotension, and venous
thromboembolism.
[References: 48]
Authors--------Lathers CM. Charles JB. Shneider VS. Frey MA. Fortney S.
Title------------Use of lower body negative pressure to assess changes in
heart rate response to orthostaticlike stress during 17 weeks of bed rest.
Source---------Journal of clinical pharmacology. 34(6):563-70, 1994 Jun.
Abstract-------This study examined the heart rate response to lower body
negative pressure (LNNP) during 17 weeks of horizontal bedrest to estimate
the development and duration of orthostatic instability elicited by this
model for space flight. Based on data from Skylab, the authors hypothesised
that orthostatic (LBNP) instability would appear during the first three to
four weeks, and would then remain constant for the duration of bedrest.
Heart rate of four healthy adult male subjects were monitored at rest and
during LBNP for 1 week of ambulatory control, 17 weeks of horizontal
bedrest, and 5 weeks of recovery. The LBNP protocol consisted of 10 minutes
of control (atmospheric pressure) and 5 minutes each at 5, 10, 20, 30,
40,and 50 mm Hg decompression, followed by a ten minute recovery period:
this protocol was repeated weekly to document the progressive changes in
heart rate response to LBNP. Lower body negative pressure was terminated
early if symptoms compatible with the onset of syncope occurred. Throughout
the study, heart rate was unchanged at 5, 10, and 20 mm Hg, but increased at
30, 40, and 50 mm Hg LBNP.
During the prebedrest period, peak heart rate was 97 +/-10 beats per minute
( mean +/- SE), occurring at 50 mm Hg for all four subjects. After 3 days
of bedrest, all monitored heart rate responses, including values after
release of LBNP were slightly elevated (NS) above pre-bedrest level. Peak
heart rate was 118 =/-21 beats/min at 50 mm Hg decompression (NS; N = 3).
Authors--------Haruna Y. Suzuki Y. Kawakubo K. Gunji A.
Institution----- Department of Health Administration, faculty of medicine,
University of Tokyo, Japan.
Title------------Orthostatic tolerance and autonomous nervous functions
before and after 20 days bedrest.
Source---------Acta Physiologica Scandinavica. Supplementum. 616:71-81,
1994.
Abstract-------To determine the critical factor that induces tachycardia
during orthostasis after bedrest, we tested some autonomous nervous
functions and the reaction to lower body negative pressure before and after
20 days of horizontal bedrest Subjects were five young healthy males and
one female. Carotid vagal baroreflex sensitivity was evaluated by cardiac
response to a gradual increase in carotid distended pressure of 150 mm Hg
within 10s by neck suction after neck positive pressure. Combined effects of
cardiopulmonary and aortic baroreflexes were assessed by the cardiovascular
responses during valsalva manoeuvre. Sympathetic reactivity was evaluated by
a cold pressor test. The carotid vagal baroreflex tended to be diminished
after bed rest in supine rest, But unchanged in seated position. Cardiac
responses to valsalva manoeuvre did not change after bed rest, although
blood pressures decreased more during the manoeuvre Cold pressor response
did not change after bed rest. Heart rate response during lower body
negative pressure was increased after bedrest. In conclusion combining our
results from several autonomous nervous functions suggested that the
exaggerated orthostatic tachycardia after bed rest could not be explained by
the changes in sensitivity of carotid, aortic, and cardiopulmonary reflexes
and sympathetic reactivity to cold stress.
Authors--------Takanaka K. Suzuki Y. Kawakubo K. Haruna Y. Yanagibori
R. Kashihara H Igarashi T. Watanabe F. Omata M. Bond-petersen F. et
al.
Institution----- Department of Laboratory Medicine, Faculty of Medicine,
University of Tokyo, Japan.
Title------------Cardiovascular effects of 20 days bedrest in healthy young
subjects.
Source---------Acta Physiologica Scandanavica. Supplementum. 616:59-63,
1994.
Abstract-------To evaluate the effects of inactivity on the cardiovascular
system in normal subjects, left ventricular echocardiography and vascular
ultrasound of the common carotid artery, abdominal aorta and femoral artery,
and lower body negative pressure tests were performed in fourteen healthy
volunteers ( mean age: 22 years) before and after 20 days of strict
bedrest. Cardiac output was calculated from echocardiographic measurements
and peripheral arterial flows multiplying cross-sectional area of artery by
heart rate and time velocity. Integrally measured by pulsed dopplar
ultrasound with angle correction. Systemic vascular resistance, lower body
vascular resistance, leg vascular resistance, lower body vascular
resistance, leg vascular resistance and head vascular resistance were also
calculated. After bed rest, heart rate increased (69 +/-2 to 79 +/-3
bpm), while left ventricular diastolic dimension (49 +/-1 mm), systolic
blood pressure (137 +/-5 to 116 +/- 4 mm Hg) Cardiac output (6.2 +/-
0.3 to 5.4 +/- 0.3 1.min-1), abdominal aortic flow (4.1 +/- 0.4 to 3.1
+/- 0.3 1.min-1), Femoral artery flow (0.66 +/- 0.07 to 0.33 +/- 0.04
1-min-1), and lower body negative pressure test tolerance time (750 +/- 71
to 582 +/-48 s) decreased significantly (p < o.05). However, common carotid
artery flow (0.97 +/-0.09 to 1.03 +/- 0.08 to 1.min-1) did not change.
Although no significant changes in systemic vascular resistance, lower body
vascular resistance, or head vascular resistance were observed, leg vascular
resistance increased significantly after 20 days of bed rest (6933 +/- 2905
to 13991 +/- 2606 dyn, s. cm-1) (p < 0.05.)
Authors--------Yanagibori R. Suzuki Y. Kawakubo K. Makita Y. Gunji A.
Institution----- Department of Health Administration, University of Tokyo.
Japan
Title------------Carbohydrate metabolism after 20 days of Bed rest.
Source---------Acta Physiologica Scandinavica. Supplementum. 616:51-7,
1994
Abstract-------To test the hypothesis that physical inactivity affects
Carbohydrate and lipid metabolism, we studied the influence of 20 days bed
rest in 14 young subjects (9 men and 5 women). There were no changes in
body weight or estimated per cent body fat after 20 days bed rest. Total
cholesterol, trygliceride, high density lipoprotein cholesterol, and
apolipoprotein B levels did not change statistically during bed rest. But
apolipoprotein A1 levels were significantly lower during and immediately
after bed rest compared with control values (p < 0.05). On the third day
of bed rest a decrease was found in hight density lipoprotein-2 cholesterol
(p < 0.05) and an increase in high density lipoprotein-3 cholesterol -- (p
< 0.01 compared with control level. To evaluate the carbohydrate metabolism,
each subject underwent a 75g oral glucose tolerance test. The glucose
concentration in response to glucose ingestion did not change during bed
rest, but insulin concentrations increased. The insulin response curve to
glucose ingestion tended to shift to the right during bed rest. From the
third day of bed rest an increase (p < 0.05) of total insulin and a decrease
(p < 0.05) in blood glucose/insulin ratio were found during the glucose
tolerance test which suggests a decrease in insulin sensitivity. These
results suggested that physical inactivity impaired carbohydrate-and lipid
metabolism.
Authors--------Nishimura Y. Fukuoka H. Kiryama M. Suzuki Y. Ikawa S.
Higurashi M. Gunji A.
Institution----- Department of Maternal and Child Health, Faculty of
Medicine, University of Tokyo. Japan.
Title------------Bone turn over and calcium metabolism during 20 days of Bed
rest in young healthy males and females
Source---------Acta Physiologica Scandinavica. Supplementum. 616:27:-35,
1994
Abstract-------Bone is a dynamic tissue that functions not only as a
mechanical support, but also as a major component of the metabolic and
endocrine systems maintaining homeostasis. It has to been shown that
immobilisation induces decalcification of the bone. To evaluate the effect
of immobilisation on bone mineral density and calcium metabolism, we
investigated 9 young healthy males and females during 20 days of bed rest.
Three methods for measuring bone mineral density were performed to quantify
whole body and regional bone changes: 1) dual energy x-ray absorptiometry,
2) Quantitative computed tomography, and 3) multiple scanning x-ray
photodesitometry, respectively. Bone mineral density showed a rapid
decreasing tendency, especially in both lumbar and metacarpal bones (mean
+/- SE: 4,6 +/- 0.6% and 3.6 +/- 0.4%, respectively). Urinary daily
excretion of deoxypyridinoline, a sensitive marker of bone matrix resorption
tended to increase by day 10, and to decline by day 20 (mean +/- SE: 42.2
+/- 1.4, 27.6 +/- 2.2 nmol day-1, respectively). However, neither alkaline
phosphatase nor tartate-resistant acid phosphatase, both markers of
osteoclast and mature osteoblast function changed. These results showed that
in the early stage of immobilisation, bone matrix might be resorbed without
any activation of osteoclasts, resulting in rapid decalcification of
vertebral and cortical bones without any discernible changes in anatomical
structure.
Authors-------- Suzuki Y. Murakami T. Haruna Y. Kawakubo K. Goto S.
Makita Y. Ikawa S. Gunji A.
Institution----- Department of Health Administration, Faculty of
Medicine,University of Tokyo, Japan
Title------------Effects of 10 and 20 days of Bed rest on leg muscle mass
and strength in young subjects.
Source---------Acta Physiologica Scandinavica. Supplementum. 616:5-15,
1994
Abstract-------Sedentary voluntary students were exposed to 10 (numbers =
8) and 20 (n = 14) days of bed rest, to study the effects of prolonged bed
rest on isometric strength of knee extension and flexion, total leg
strength, right hand grip and elbow flexion using different dynamometers.
Further, muscle mass of right leg and arm was measured by dual energy x-ray
absorptiometry, and cross sectional areas of right thigh by x-ray computed
tomography, before and after bed rest and after 4 ort 8 weeks of recovery.
After 10 days bed rest, these variables tended to decrease except for the
muscle mass of right arm which increased. After 20 days of bed rest, a
similar trend was observed, but at a statistically significant level of
(p < 0.05), However, no correlation was observed between the decrease in
knee extensor strength and cross sectional area of the thigh. Nor was a
correlation observed between the sum total of isometric strength of the leg
and the total muscle mass measured. The 24 hour urinary excretion of N2 and
creatinine was not changed through these experiments. During recovery, the
variables measured had reached the initial levels after 4 or 8 weeks. These
changes were not affected by mild supine exercise training. The results
suggest that isometric muscle strength was decreased in non-antigravity
muscles as well as antigravity muscles by prolonged bed rest, but the rate
of changes did not correlate to the corresponding changes in muscle mass.
The decreases in maximum voluntary strength are probably not only due to the
decrease in muscle mass, but also due to reductions of neuromuscular
functions.
Authors--------Federson BJ. Schlemmer A. Hassager C. Christiansen C.
Institution----- Centre for Clinical and Basic Research, Ballerup, Denmark.
Title------------Changes in the carboxyl-terminal propeptide of type I
Procollagen and other markers of bone formation upon five days of bedrest.
Source---------Bone, 17(1):91-5, 1995 Jul.
Abstract-------This study was performed in order to investigate the
influence of skeletal unloading on the serum concentration of the
carboxylterminal peptide of type I procollagen= (sPICP) and other markers
of bone formation. Blood samples were taken every third hour from nine
healthy pre-menopausal women (22-29 years) in two 24 hour studies, before
and at the end of five days of bedrest. Furthermore, a set of samples were
taken 12 hours apart after three days of bedrest. We measured sPICP, the
serum concentration of intact and N-terminalMid fragment osteocalcin =(sOC)
and the serum concentration of alkaline phosphatase =(sAP). During the five
days of bedrest increase in sOC was observed, while sPICP gradually
decreased. sAP was unchanged. Five days of bedrest resul
ted in the following overall changes in the 24 hour mean values : sPICP -14%
(p = 0.002); sOC =9% (p = 0.009); sAP -1% (not significant).
The circadean patterns did not change significantly after bedrest. It is
puzzling that the changes in the bone formation markers are of different
magnitude and for sPICP and sOC even in opposite directions. The increase in
sOC may be caused by an increase in sOC osteoblasts or a release of bone
incorporated OC from resorbing sites; the accompanying decrease in sPICP may
indicate that bone formation is actually transiently decreased after short
term bedrest.
Authors-------Maloni J A.
Institution----- University of Winsconsin-Madison, School of Nursing, 600
Highland Ava, Madison, W153792-2455.
Title------------Bed rest and high-risk pregnancy: differentiating the
effects of diagnosis, setting, and treatment.
Source---------Nursing Clinics of North America. 31 (2):313-25, 1996 June.
(35 ref)
Abstract-------Current research on high-risk pregnancy has confounded the
effects of diagnosis, setting and treatment. Studies of pregnancy bed rest
have demonstrated a beginning attempt to differentiate the influences of
confounding variables and, similar to high-risk studies, have found that
depression, anxiety, other disturbing emotions, and separation from family
are common side effects. It is likely that some of the effects previously
attributed to high risk pregnancy may be either caused or heightened by
activity restriction. This article identifies the major issues to be
considered when studying high-risk pregnant women. Furthermore, it suggests
that, if activity restriction must be prescribed, the adverse effects of
treatment upon both the woman and her child should be considered in the
decision making process.
Copyright © 96 by W B Saunders Company (35 ref)
Authors-------Hangartner T N.
Institution----- BioMedical Imaging Laboratory, Wright State University, 504
E Blgd, One Wyoming St, Daytona, OH 45409
Title------------Osteoporosis due to disuse.
Source---------Physical Medicine & Rehabilitation Clinics of North America.
6(3):579-94, 1995, AUG. (34ref)
Authors-------Kardong-Edgren S.
Institution-----University of Texas, Arlington School of nursing, Arlington,
TX.
Title------------Research for Practice. Rethinking the wisdom of antepartum
bed rest
Source---------American Journal of Nursing. 96 (1 Contin Care Extra Ed) :53,
1996 Jan.
Authors------- St. Pierre B A. Flaskerud JH.
Institution----- Pennsylvania State University, Noll \physiological
Research Centre, University Park, PA 16802-6900.
Title------------Clinical nursing implications for the recovery of atrophied
skeletal muscle following bed rest
Source---------Rehabilitation Nursing. 20(6):314-7,345, 1995 Nov-Dec.
(17ref)
Abstract-------Atrophied skeletal muscle is a common clinical manifestation
of bed rest that occurs primarily because of a lack of weight-bearing
activity on the muscle. Findings from several studies using an animal model
to simulate the effects of bed rest on muscles indicate that when atrophied
muscle is used again for weight bearing activity , it undergoes a series of
physiological changes, such as muscle fibre (myofibre) damage, death, and
regeneration. Also, in the recovering muscle, the inflammatory white blood
cells, called macrophages, accumulate and shift in hype in relation to the
ongoing myofibre changes. Similar processes may occur in the muscles of a
patient resuming normal physical activity following bed rest.
Authors-------Anonymous.
Title------------Bed rest considered unhealthy for pregnant women, study
finds.
Source---------Nursing News (New Hampshire). 44(2):9, 1994 Apr.
Authors-------Brown M. Hasser E M.
Institution----- Program in Physical Therapy, Box 8052, Washington
University School of Medicine, 660 S Euclid Ave, St Louis MO 63110.
Title------------Weight Bearing effects on skeletal muscle during and after
simulated bed rest.
Source---------Archives of Physical Medicine & Rehabilitation. 76(6):541-6,
1995 June. (28ref)
Abstract-------The detrimental consequences of bed rest include a rapid loss
of muscle mass and strength. Yet, the utility of treatment to offset the
effects of bed rest has not been well established. It was the purpose of
this study to examine the effects of therapeutic intervention of simulated
bed rest in rats.
Simulated bed rest was accomplished by unweighting the hind limbs of rats
for 2 weeks. The rats were allowed one week of cage recovery.
Results strongly support early intervention, particularly weight bearing,
during a period of bed rest to modify the decline in strength and muscle
mass in postural muscles such as the soleus. Further, results suggest that
simply sending a patient home from the hospital to recover from bed rest
delays return of strength unnecessarily. © 1995.
Authors-------Dean E.
Institution----- School of Rehabilitation Medicine, University of British
Columbia, 2211 Westbrook Mall, Vancouver, BC V6T 2BS
Title------------Bedrest and deconditioning
Source---------Neurology Report. 17(1):6-9, 1993 Mar. (47ref)
Authors-------Vorhies D. Riley B E.
Institution----- Portland VA Medical Center, Dept Veterans Affairs, 3710
S.W. US Veterans Hospital Road, P O Box 1034, Portland, OR 97204.
Title------------Deconditioning
..Changes in organ system
physiology
.induced by inactivity and reversed be activity.
Source---------Clinics in Geriatric Medicine. 9(4):745-63, 1993 Nov.
(21ref)
Authors-------Anonymous
Title------------Side effects of bed rest.
Source---------Childbirth Instructors Magazine. 4(4): 1994 Autumn.
Authors-------Beck C T.
Title------------ Critique of Physical and psychosocial side effects of
antepartum hospital bedrest [Original article by Maloni J et al appears in
NURS RES 1993; 42(4):197-203].
Source--------- Nursing scan in research. 7(2)19, 1994 Mar-Apr.
Abstract-------SYNOPSIS: Bed rest either at home or in the hospital has been
proscribed extensively to manage women with prenatal complications. Little
is known, however, about the effects of bedrest on the women themselves. The
purposes of this study were to (1) to describe the physical and psychosocial
effects of prenatal bed rest in the hospital on pregnant woman, and (2) to
investigate whether the symptoms differed from those exhibited by pregnant
women not on bed rest. The sample consisted of three groups of pregnant
women10 on complete bed rest, 7 on partial bed rest, and 18 not on bed rest
(normal).
Result indicated that pregnant women on complete bed rest needed greater
time to re-oxygenate muscle tissue after exercise, gained less weight, and
experienced greater dysphoria than pregnant women on partial bed rest. The
greatest hospital stress or for women on complete bed rest was separation
from family. Postpartum symptom severity decreased for mothers who had not
been on antepartum bed rest. But not for women in the partial and complete
bed rest groups. During the postpartum period, women on bed rest experienced
more shortness of breath on exertion and deep muscle soreness, specially of
the back and legs, than women who had not been on antepartum bed rest.
Authors-------Mackey MC.
Title------------ Commentary on Physical and psychosocial side effects of
antepartum hospital bed rest [Original article by Maloni J et al appears in
NURS RES 1993;42(4):197-203].
Source---------AWHONNs Womens Health Nursing Scan. 8(1):9 1994 Jan-Feb.
Abstract-------SYNOPSIS: Researchers studied women on complete bed rest
(numbers=10), partial bed rest (n=7), and no bed rest (n=18) from 28to 32
weeks gestation until 2 to 6 weeks postpartum. Women on complete bed rest
had decreased muscle function, greater weight loss and greater antepartum
dysphoria(anxiety, hostility, depression) than the women on partial or no
bedrest. Separation from the family was the most stressful of the antepartum
stressors. The number and severity of physical and psychosocial symptoms
showed a significant decrease postpartum for the non-bed rest (normal)
group, but not in the two bed rest groups. Women on bed rest reported
antepartum boredom and postpartum shortness of breath on exertion and deep
muscle soreness. Bed rest groups had difficulty and delays in assuming
ambulation and activities of daily living.
Authors-------Terribilini C
Title------------Can rest actually prolong low back pain?
Source---------Jems: Journal of Emergency Medical Services. 18(7):101-2,
1993 Jul. (4ref)
Authors-------Maloni J A.
Institution----- School Nurs, Univ Wisconsin-Madison, 600 Highland Ave,
Madison W153792.
Title------------Bed rest during pregnancy: Implications for nursing.
Source---------JOGNN-Journal of Obstetric, Gynecologic, & Neonatal Nursing.
22 (5):422-6,1993 Sep-Oct. (22ref)
Abstract-------Research on non-pregnant individuals reveal that bed rest
produces numerous adverse physical and psychosocial effects. Evidence shows
that bed rest effects pregnant women in the same manner. This article
provides an overview of the history of bed rest, research on the side
effects of bed rest, and a discussion of the research that has been
conducted on these side effects during pregnancy. Also discussed are
implications for providing antepartum, intrapartum and postpartum nursing
care. (22ref)
Authors------- Maloni J A. Chance B. Zhang C. Cohen AW. Betts D. Gange
S J.
Institution----- School of Nurs, Univ Winsconsin-Madison, Madison, W153792
Title------------NLM Unique identifier: 93330822. Name unknown
Source--------- Antepartum hospital stressors Inventory (ASHI) (White).
Antepartum/Postpartum Symptoms Checklist (APSC).
Abstract-------Women on complete bed rest (n=10) had greater gastrocnemius
muscle dysfunction, weight loss, and dysphoria than women on partial bed
rest (n=7) or no bed rest (n=18). The severity of the side effects appeared
to be directly related to the degree of severity restriction. (42ref).
Authors-------Maloni J A. Kasper C E.
Institution----- Asst Prof, School Nurs, Univ Winscon-Madison, 600 Highland
Ave, Madison, W153792
Title------------Physical and psychosocial effects of antepartum hospital
bed rest: A review of the literature.
Source---------ImageThe Journal of Nursing Scholarship. 23(3):187-92,
1991 Fall. (91ref)
Abstract-------Despite the relative disuse of bed rest among hospital
patients in general, prolonged bed rest is a common obstetrical modality for
treatment of premature labour, premature rupture of membranes, placenta
previa, incompetent cervix, intrauterine foetal growth retardation, and
pregnancy induced hypertension.
It is believed that bedrest improves uterine perfusion and decreases the
physical forces that stimulate cervical effacement and dilation, thereby
providing rest and recovery for the mother while prolonging foetal time in
utero for maturation (Bedrest in Obstetrics, 1981; Cunningham MacDonald &
Gant, 1989; Gabbe Neibyl & Simpson, 1986). However, the exact mechanism by
which bed rest facilitates these effects is unclear (Cunningham et al.,
1989). Investigations into the efficacy of bed rest as a treatment for woman
with high risk pregnancy are limited; The majority have been conducted in
Europe on twin pregnancies. There are relatively few controlled studies and
the results are conflicting. (Cunningham et al., 1989; Iams, Johnson &
Creasy, 1988). The purpose of this article is to review the current research
on bed rest in pregnant and non pregnant populations and to discuss the
possible interaction of the physical and psychosocial effects of bed rest in
the anepartum and postpartum periods. (91) ref
Authors-------Gogia P P. Scneider V S. LeBlanc A D. Krebs J. Kasson C.
Pientok C.
Title------------Bed rest effect on extremity muscle torque in healthy men.
Source---------Archives of Physical Medicine & Rehabilitation.
69(12):1030-2, 1988 Dec. (27ref)
Authors-------Anonymous
Title------------How bed rest changes perseption.
Source---------American Journal of Nursing. 88(1):55-8, 1988 Jan. (10ref)
Authors-------Rubin M
Title------------The physiology of bed rest
Source---------American Journal of Nursing. 88(1):50-5, 57-8, 1988 Jan.
(25ref)
Authors-------Caplin M.
Title------------Early mobilisation of uncomplicated myocardial infarction
patients
Source---------Focus on Critical Care. 13(2):36-40, 1986 Apr. (31ref)
Authors-------Winslow E H.
Title------------Cardiovascular consequences of bed rest.
Source---------Heart & Lung : Journal of Critical Care. 14(3):236-46, 1985
May. (51 ref)
Authors-------Chuman M A.
Title------------Risk factors associated with ulnar nerve compression in
bedridden patients
Source---------Journal of Neurosurgical Nursing. 17(6):338-42, 1985 Dec.
(17ref)
Authors-------Asher R A J.
Title------------The dangers of going to bed
Source---------Critical care update. 10(5):40-1,51, 1983 May.
Sudden infant Death Syndrome (cot death)
cot death
or sudden infant death syndrome (SIDS)
the death of an apparently healthy baby, almost always during sleep. It is
most common in the winter months, and strikes more boys than girls. The
cause is not known but risk factors that have been identified include
prematurity, respiratory infection, overheating and sleeping position.
Hutchinson Science Library
Copyright (c) 1996 Helicon Publishing
Authors-------Willinger M.
Title------------Sleep position and sudden infant death syndrome.
Source---------Jama: Journal of The American Medical Association.
273(10):818-9, 1995 Mar 8. (15ref)
Authors-------Klonoff-Cohen H S. Edlestein S L.
Institution----- Dept of Family and Preventitive Medicine, Division of
Epidemiology, 9500 Gilmore Drive, 0607, La Jolla, CA 92037-0607.
Title------------A case control study of routine and death scene sleep
position and sudden infant death syndrome in Southern California.
Source---------Jama: Journal of American Medical Association.
273(10):790-4, 1995 Mar 8. (32ref)
Authors-------Dwyer T. Ponsonby A. Blizzard L. Newman N M. Cochrane J A.
Institution-----Menzies Centre for Population Health Research, GPO Box
252C, Hobart 7000, Tasmania, Australia.
Title------------The contribution of changes in the prevelance of prone
sleeping position to the decline in sudden infant death syndrome in Tasmania
Source---------Jama: 273(10):783-9, 1995 Mar *. (36ref)
Authors-------Anonymous
Title------------ Reserve findings
.sudden infant death syndrome among
native Americans
Source---------Nursing Times. 90(46):18, 1994 Nov 16-22
Authors--------Yelland J. Gifford S. Macintyre M.
Title------------ Explanatory models about maternal and infant health IN:
Asian mothers, Australian birth. Pregnancy, Childbirth and childbearing: the
Asian experience in an English-speaking country (Rice PL).
Source---------Ausmed Publ (Melbourne, Victoria, AUSTRALIA) ** 1994 (pp
175-90)
Authors-------Millar WJ. Hill G B
Institution-----Canadian Ctr Health Information, Statistics Canada, 18th
Floor, RH Coast Building, Tunneys Pasture, Ottawa ON K1A 0T6 Canada..
Title------------ Prevelances of sudden infant death syndrome in Canada.
Source---------Canadian Medical Association Journal. 149(5):629-35, 1993
Sep1. (29REF)
Authors-------Gantney M. Davies D.
Title------------ Ethinic variations in the incidences of SIDS.
Source---------Proffessional Care of Mother and Child. 3(7):208-11, 1993
Jul-Aug. (19ref)
Authors-------Gilbert-Barness E F. Barness L A.
Title------------ Sudden Infant Death Syndrome
Is it a cause of death?
Source---------Archeives of Pathology & Laboratory Medicine. 117(12):12
46-8, 1993 Dec. (26ref)
Authors-------Campen J M.
Title------------ SIDS: There are no answers
only victims.
Source---------Childbirth Instructor. 3(1): 43-7, 1993 Winter. (19ref)
Authors------- Anonymous
Institution----- Corporate Author New South Wales Health Department.
Title------------ Infant Mortality and SIDS in NSW 1969-1987.
Source---------Paediatric Nursing Review. 5(2):5-6, 1992 June. (4ref)
Authors-------Brooks JG
Institution----- Dept Paediatrics, Univ Rochester School of Med, 601 Elmwood
Ave, Rochester, NY 14642.
Title------------Unravelling The mysteries of Sudden Infant Death Syndrome.
Source---------Current Opinion in Paediatrics. 5(3):266-72, 1993 Jun.
(39ref)
Authors-------Campen J.
Title------------ Statistics corner
in the quiet of the night: SIDS.
Source---------International Journal of Childbirth Education. 7(3):5-8,
1992 Aug. (20ref)
Authors-------Malloy M H. Hoffman H J. Peterson D R.
Institution----- Dept Paediatrics, Rte E-26, Univ Texas Med Branch,
Galveston, TX 77550.
Title------------ Sudden Infand Death Syndrome and maternal smoking
Source---------American Journal of Public Health. 82(10):1380-2, 1992 Oct.
(8ref)
Abstract-------Data from Missouri for the period 1980to 1985 suggest a dose
response relationship between smoking during pregnancy and the incidence of
sudden infant death syndrome (SIDS).
However, Data from the National Institute of Child and Human Development
SIDS Cooperative Epidemiological study did not support a dose-response
relationship. Neither did the Missouri data support a relationship between
the age of occurance of SIDS and smoking during pregnancy. (8ref)
Authors--------Jackson S.
Title------------ Sudden Infant Death Syndrome: Definition and
classification of SIDS
part1.
Source---------Midwives Chronicle. 105(1255):240-3, 1992 Aug.
Authors--------Guntheroth W G. Lohmann R. Spiers PS.
Institution----- UNIV Washington Dept Paediatrics, RD-20, Seattle, WA 98195.
Title------------ A Seasonal assosiation between SIDS deaths and
Kindergarten absences.
Source---------Public Health Reports. 107(3):319-23, 1992 May-Jun. (28ref)
Abstract-------Data from linked birth and death cirtificates from the State
of Oregon were used to determine the monthly distribution of deaths from
sudden infant death syndrome (SIDS) for the years 1976 through 1984. The
monthly number of SIDS deaths increased in winter and decreased in summer,
when schools usually are not in session. 1979-84. School abscences from
kindergarten were determined from school records for the period. 1979-84.
School absences, previously shown to reflect incidence of predominantly
infectious diseases, were found to be positively correlated with occurrences
of SIDS. The role of ordinarily non-lethal infections in occurrences of SIDS
has been established by history, histology, and viral isolation. The authors
conclude that the seasonality of SIDS is related to the seasonality of
respiratory infections and that the seasonality is influenced by respiratory
infections being spread from school children to infants during periods when
schools are in session. (28ref)
Authors--------Germain F. Guell A. Marini J.F.
Institution----- Aix-Marseille 11 Universite, UFR STAPS 163, Marseille,
France
Title------------ Muscle strength during bedrest, with and without exercise
as a countermeasure.
Source---------European Journal of Applied Physiology and Occupational
Physiology. 71(4):342-8,1995.
Abstract-------Bedrest is known to be a useful experimental model for
simulating weightlessness and studying its effect on human skeletal muscle
activity. We therefore conducted a study in which 12 healthy male subjects
underwent 28 days of continuous exposure to a 6 degrees head down bedrest.
Our main objective was to test a set of preventative countermeasures for
maintaining the stability of the human body. Of the subjects 6 performed
deadlifts in the supine position for 30 to 45 minutes each day. The
isometric were performed for 530 s at 90, 120 and 150 degrees knee angles
and isokinetic training at speeds of at 30 and 150 degrees,, s1. In vivo
quadriceps muscle strength was measured under controlled experimental
conditions with a commercial dynamometer. The hypothesis that intense daily
isometric and isokinetic leg exercise and lower body negative pressure
(LBNP) might serve to maintain muscle strength under conditions of
weightlessness was tested. Of the subjects 6, who did not perform any
exercise, served as the control population under conditions of simulated
weightlessness.
The results showed that a significant reduction (p < or = 0.0001) in the
muscle force [ -10. 3 (SD 6.7%)] occurred in the control group, whereas no
significant changes were observed in the trained group [+3.9 (6.8%)]. From
these studies we conclude that intense muscle training and LBNP constitute
efficient countermeasures to compensate for the biomechanical effects of
weightlessness on human lower limbs and to limit other factors such as
cardiovascular deconditioning.
Authors--------Traon A.P. Vassuer P. Arbaeille P. Guelle A. Bes A.
Gharib C.
Institution----- MEDES, Institut de Medecine et de Physiologic Spatials,
Toulouse, France.
Title------------ Effects of 28 day head down tilt with and without
countermeasures on lower body negative pressure responses
Source---------Aviation Space & Environmental Medicine. 66(10:952-91, 1995
Oct.
Abstract------- This study was performed to determine the effects of 28 day
head down tilt = (HDT)- (simulated weightlessness) on cardiovascular
responses to orthostatic stress induced by lower body negative pressure =
(LBNP) (before during and after HDT) and + 60 degrees head up tilt (before
and after HDT ) in 12 subjects. Half of them underwent counter measures =
(CM) of regular muscular exercise Isometric and isokinetic training) and
LBNP sessions (-30 mm Hg) as generally performed during spaceflight; the
other six were a control group (C). The countermeasure effect on the
orthostatic responses to LBNP and tilt test was assessed by studying the
changes after HDT in the two groups.
Essentially, blood pressure was maintained in group (CM) in the tilt test
after HDT (MBP at the end of the tilt vs . baseline value: + 16% (CM). LBNP
and muscular exercise may have contributed to this improvement. One of the
probable contributing factors is the relative conservation of plasma volume,
at the end of HDT, in group (CM) (-2.2%), compared to group (C) (-11.2%).
Transcranial dopplar (TDC) recordings of middle cerebral artery (MCA)
velocities permitted indirect evaluation of cerebral blood flow changes
during the orthostatic tests. MCA velocities decreased significantly
although slightly (-7 to -12%) during LBNP sessions without changes along
the HDT showing that the cerebral circulation was well preserved in each
group. On the other hand, subjects undergoing presyncopal symptoms presented
a drop in MCA velocities, suggesting a decrease in cerebral blood flow.
Authors-------Durnova G.N. Burkovskaia TE. Voraotnikova E.V. Kaplanskil
A.S. Arustamov O.V.
Title------------[The effect of weightlessness on fracture healing of rats
flown on Biosatellite Cosmos-2044]. [Russian]
Original title-Vliianie nevesomosti na zazhivienie perelomov kostei ukrys,
eksponirovannkyh na biosputnike Kosmos -2044
Source---------Kosmicheskaia Biologiia I Aviakosmosmicheskaia Meditsina.
25(5):29-33, 1991 Sep-Oct.
Abstract-------Two days before launch of the biosatellite Cosmos -2044 five
rats were exposed to surgical intervention: their fibulas were cut
bilaterally. The purpose was to study the effect of microgravity on bone
fracture healing. Histologically and histomorphometrically it was
demonstrated that haling was inhibited: as a result, bone callus was poorly
developed and bone fragment consolidation was inadequate. An increase in the
relative volume of osteoid and a simultaneous decrease in the number and
activity of osteoblasts point to mineral disorders of newly formed bone in
microgravity. Study of untreated tibia showed that exposure to microgravity
led to osteoporosis of proximal metaphyses. This osteoporosis was produced
by inhibited neoformation and enhanced resorption of bone. Comparative
analysis of injured fibula and untreated tibia of rats exposed to real
microgravity for 14 days or tail suspended demonstrated similarity of
changes. This indicates that tail suspension can be viewed as an adequate
simulation of microgravity with respect to changes in hind limb bones.
Authors--------Natochin IuV. Serova LV.
Institution-----
Title------------ [Water salt Homeostasis in Rats during spaceflight].
[Russian]
Original titleVodno-solevoi gomeostaz u krys v usloviiakh kosmicheskogo
polets.
Source---------Aviakosmicheskaia I Ekologicheskaia Meditsina. 29(4):41-7,
1995.
Abstract-------The paper generalised the results of a series experiments
aimed at studying liquid and electrolytes contents in various organs and
tissues of rats following three-week space flights (SF). The results
ascertain high reliability of the water-salt homeostasis maintaining system,
which ensures stable water and electrolytes amounts in the majority of
animal tissues in SF. The following alterations appear to be of great
significance : deduced potassium levels in the heart ventricle tissues in
male rats after short-duration (7-9days) exposure in SF, zero-G-induced
degradation of the body ability to bind potassium at injection of isotonic
solution (KC) into the stomach; redistribution of potassium ions between
mother and developing foetuses in space experiments with pregnant animals.
Simulated experiments showed similar shifting of potassium ions in the
mother foetus system may be due not to weightlessness exclusively but other
impacts, I.E. they are not specific.
Authors--------Drummer C. Heer M, Dressendorfer RA. Strasburger CJ.
Gerzer R.
Institution----- Medizinishe Klinik, Klinikum Innenstadt, Universitat
Munchen.
Title------------ Reduced natriuresis during weightlessness.
Source---------Clinical Investigator. 71 (9):678-86, 1993 Sep.
Abstract-------The kidney response to weightlessness was measured in one
volunteer during a one week space mission. Shortly after entering
microgravity and later during the mission, consecutive urine sampling
periods were monitored, covering in total about fifty percent of the
inflight time. Preflight references were a sequence of ground-based
experiments, which evaluated body fluid metabolism with different degrees of
standardisation. Additional variables, such as circadian rhythms and
cortisolassociated stress; were also monitored. In contrast to current
hypotheses, the volunteer showed a pronounced reduction in natriuresis and
diuresis during the entire spaceflight, despite a considerable weight loss.
For the first time, the urinary excretion of the renal natriuretic peptide
urodilatin was also measured. Both, during the preflight experiments and
during weightlessness, close correlations between urodilatin excretion and
sodium excretion were observed. However, the correlation between natriuresis
and urodilatin was considerably altered during weightlessness. We conclude
that the loss of body weight during spaceflight is not related to an
increased renal fluid loss and that urodilatin might counteract the decrease
in renal excretion observed in weightlessness.
Authors--------Bernardi M. Trevisani F. Fornale L. Di Marco C.
Gasbarrini A. Baraldini M. Ligabue A. Gasbarrini G.
Institution---- Patalogia Spaciale Medica I, University of Bologna, Italy.
Title------------Renal sodium handling in cirrhosis with assites: mechanisms
of impaired natriuretic response to reclining.
Source---------Journal of Hepatology. 21(6): 1116-22, 1994 Dec.
Abstract-------We recently showed that patients with compensated cirrhosis
can dispose of their fluid overload while reclining. In contrast, patients
with ascites fail to develop supine-induced natriuresis. To assess the
effect of reclining on renal sodium handling in patients with advanced
cirrhosis and the mechanisms blunting natriuresis in this situation, renal
function and plasma concentrations of atrial natriuretic factor, aldosterone
and norepinephrine were evaluated in 10 nonazotemic patients with cirrhosis
and ascites and 10 healthy controls standing for 2 hours and reclining for 2
hours. While standing, all patients showed marked sodium retention and
significantly elevated plasma atrial natriuretic factor levels, aldosterone
and norapinephrine. Glomerular filtration rate did not differ from healthy
controls. The reclining increased renal sodium excretion in both groups, but
this change was far less marked in patients: Natriuresis only rose to the
control range in two of them. An increase in atrial natriuretic factor and a
depression of plasma aldosterone and norepinephrine was seen in both
controls and patients. In the latter despite the greater change in atrial
natriuretic factor aldosterone, the aldosterone to atrial natriuretic factor
ratio, which was inversely correlated with natriuresis during both standing
and reclining remained significantly elevate. In the two patients who
achieved normal natriuresis during reclining, reclining was associated with
both the normalisation of the aldosterone/atrial natriuretic factor ratio,
and with an increase in glomerular filtration rate. The supine-induced
increase in atrial natriuretic factor was not only preserved but was even
enhanced in cirrhosis with ascites.
Registry numbers 51-41-2 (Norepinephrine. 52-39-1 (Aldosterone).
&440-23-5 (Sodium). 85637-73-6 (Atrial Natriuretic Factor).
Authors--------Gerbes AL. Pliz A. Wernze H. Jungst D.
Institution----- Medizinische Klinik II, Klinikum Grosshadern,
LudwigMaximiliansUniversitat Munchen.
Title----------- Renal sodium handling, neurohumoral systems in patients
with cirrhosis in sitting posture : effects of spironolactone and water
immersion.
Source---------Clincal Investigator. 71 (11):894-7, 1993 Nov.
Abstract--------Renal sodium handling, neurohumoral systems, and systemic
hemodynamics were investigated under baseline conditions in sitting posture
in 10 healthy subjects, 11 patients with cirrhosis without, 10 patients with
cirrhosis with ascites. Furthermore, the effects of head out of water
immersion, 1 week spironolactone administration, on the combination was
assessed in the two groups of patients. Patients Without ascites exhibited a
significant increase in plasma norapinephrine concentration and a tendency
towards an increase in plasma aldosterone concentration. Patients with
ascites had a significantly lower mean arterial blood pressure despite
significant reduction of urinary sodium excretion and fractional sodium
excretion as well as an increase in plasma aldosterone, and norepinephrine
concentration. In patients with ascites the increase in renal sodium
excretion and fractional sodium excretion following water immersion or
spironolactone was clearley augmented by the combination of the two
maneuvers. The same pattern was observed in patients without ascites. Our
findings (a) underscore the importance of studying hemodynamics, renal
function, and neurohumoral systems also in upright posture, (b) suggest a
role of sympaticoadrenergic activation and proximal sodium retention in
preascetic patients, and (c) are compatible with vasodilation hypothesis of
ascites formation.
Registry numbers 0 (Neurotransmitters). 51-41-2 (Norepinephrine).
52-01-7 (Spironolactone). 7732-18-5 (water).
Authors--------
Institution-----
Title------------
Source---------
Abstract-------
Authors--------Frey MA. Maeder TH. Bagian JP. Charles JB. MeshanRT.
Institution----- US Army, Madigan Army Medical Centre, Tacoma, Washington
98493.
Title------------ Cerebral blood velocity and other cardiovascular responses
to 2 days head down tilt.
Source---------Journal of Applied Physiology. 74(1) :319-25, 1993 Jan.
Abstract-------Spaceflight induces a cephalad redistribution of fluid volume
and blood flow within the human body, and space motion sickness, which is a
problem during the first few days of spaceflight, could be related to these
changes in fluid status and in blood flow of the cerebrum and vestibular
system. To evaluate possible changes in cerebral blood flow during simulated
weightlessness, we measured blood velocity in the middle cerebral artery
(MCA) along with retinal diameters, intracellular pressure, impedance
cardiography, and sphygmomanometry on nine men (26.2 +/-6.6 yr) morning and
evening for two days during continuous ten degrees head down tilt (HDT).
When subjects went from seated to head down bed rest, their heart rate and
retinal diameters decreased, and intravaocular pressures increased. After 48
h of HDT, blood flow velocity in the MCA was decreased and thoracic
impedance was increased, indicating less fluid in the thorax. Percent
changes in blood flow velocities in the MCA after 48 h HDT were inversely
correlated with percentage changes in retinal vascular diameters. Blood flow
velocities in the MCA were inversely correlated (intersubject) with arterial
pressures and retinal vascular diameters. Heart rate, stroke volume, cardiac
output, systolic arterial pressure, and at times pulse pressure and blood
flow velocities in the MCA were greater in the evening. Although cerebral
blood velocity is reduced after subjects are head down for 2 days, the
inverse relationship with retinal vessel diameters, which have control
analogous to that of cerebral vessels, indicates cerebral blood flow is not
reduced.
Authors--------Yamaguchi M. Hoshi T.
Institution----- Laboratory of metabolism and Endocrinology, Graduate School
of Nutritional Sciences, University of Shizuoka, Japan.
Title------------ Simulated weightlessness and bone metabolism:
Gravitational stimulation enhances insulin sensitivity.
Source---------Research in Experimental Medicine. 192(5):345-53, 1992.
Abstract-------The effect of simulated weightlessness on bone metabolism was
investigated in skeletal unloading for 4 days. Skeletal unloading was
designed using the model for hind limb hang in rats.
Skeletal unloading with hind lib hang caused a significant decrease of
alkaline phosphatase activity, deoxyribonucleic acid (DNA) content, and
glucose consumption in the femoral-diaphyseal tissues were cultured in the
presence of insulin (10(-8) M), the hormone produced a significant increase
of alkaline phosphatase activity and decrease of glucose consumption in the
femoral -diaphyseal tissues obtained from normal rats. This hormonal effect
was not seen in the femoral diaphysis but in the calvaria of rats with
skeletal unloading. However, insulin effect was seen in the femoral
diaphysis obtained at 3 days after the removal of skeletal unloading.
Meanwhile, the presence of other bone-regulating factors (10(-8) M
parathyroid hormone [1-34] and 10(-4) M zinc sulphate) revealed an
appreciable effect on alkaline phosphatase activity in the femoral diaphysis
from rats with skeletal unloading. These results suggest that gravitational
stimulation can directly enhance a specific insulin sensitivity in the
regulation of bone metabolism.
Authors--------Englemann U. Krassnigg F. Schill WB.
Institution----- Department of Dermatology and Andrology, Justus Liebig
University Glessen, Germany,
Title------------ Sperm motility under conditions of weightlessness
Source---------Journal of Andrology. 13(%):433-6, 1992 Sep-Oct.
Abstract-------The aim of this study was to determine the differences in
motility of frozen and thawed bull spermatozoa under conditions of
weightlessness compared with ground conditions. The tests were performed
within a series of scientific and technological experiments under
microgravity using sounding rockets in the technologische Experiments Unter
Schwerelosigkeit (TEXUS) program launched in Kiruna, North Sweden. Using a
computerised sperm motility analyser, significant differences were found in
sperm motility under microgravity, compared with sperm under gravitational
conditions on earth. Computer analysis showed alterations in straight line
and curvilinear velocity, as well as in linear values. The amount of
progressively motile spermatozoa, including all spermatozoa with a velocity
>20 microns/second, increased significantly from 24% +/- 7.6% in the
microgravity test. In conclusion, there is strong evidence that gravity
influences sperm motility.
Authors--------Sulzman FM. Ferrero JS. Fuller CA. Moor-Ede MC. Klimovitsky
V. Alpatov AM.
Institution----- Division of Life Sciences, National Aeronautics and Space
Administration, Washington, DC 20546.
Title------------Thermoregulatory responses of rhesus monkeys during
spaceflight.
Source---------Physiology & Behaviour. 51(3):585-91, 1992 Mar.
Abstract-------This study examines the activity, auxiliary temperature
(T(ax)), and ankle skin temperature (Tsk of two male rhesus monkeys exposed
to microgravity in space, The animals were flown on a Soviet biosatellite
mission (COSMOS 1514). Measurements on the flight animals, as well as
synchronous flight controls, were performed in the Soviet Union. Additional
control studies were performed in the U.S. to examine he possible role of
metabolic heat production in the T(ax) response, observed during the
spaceflight. All moneys were exposed to a 24 h light -dark cycle (LD 16:8)
throughout these studies. During weightlessness, T(ax) in both flight
animals was lower that on earth. The largest difference (0.75 degree C)
occurred during the night. There was a reduction in mean heart rate and Tsk
during flight. This suggests a reduction in both heat loss and metabolic
rate during spaceflight. Although circadian rhythms in all variables were
present during flight, some differences were noted. For example, the
amplitude of the rhythms in Tsk and activity were attenuated. Furthermore,
the T(ax) and activity rhythms did not have precise 24.0hour periods and may
have been externally desynchronised from the 24-h LD cycle. These data
suggest a weakening of the coupling between the internal circadian
pacemaker and the external LD.
Authors--------Shultz H. Hillebrecht A. Keremaker JM. Ten Harkel AD.
Beck L. Baisch F. Meyer M.
Institution----- Max-Planck-Institute for Experimental Medicine, Gottingan,
Germany.
Title------------ Cardiopulmonaryfunction during ten days of head down tilt
bedrest.
Source---------Acta Physiologica Scandinavica. Supplimentum. 604:23-32,
1992
Abstract-------Pulmonary and cardiovascular responses to simulated
weightlessness, i.e. six degrees head down tilt bedrest (HDT) were
investigated in six healthy male volunteers (mean age 26 years). Pulmonary
diffusing capacity, functional; residual capacity, pulmanary capillary blood
flow, and lung tissue volume were measured by inert gas re-breathing. Heart
rate and mean arterial blood pressure were obtained from finger blood
pressure readings using a plethysmographic technique (Finapress). The short
term (20 min) response to HDT consisted of a 22% increase in pulmonary blood
flow, and 13 % and 31% falls in blood pressure and heart rate relative to
standing. Functional residual capacity fell by 33%, while lung tissue volume
increased insignificantly. Subsequent measurements during ten days of HDT
and 5 days of recovery revealed no further changes in lung volume, lung
tissue volume, or blood pressure. However, diffusing capacity fell gradually
and remained 4%-5% below baseline values after the 7th day of bedrest and
during recovery (p less than 0.05). Pulmonary blood flow decreased by 16%
during HDT and recovered partially within the following five days (p less
than 0.05). We conclude that during and after simulated weightlessness,
marked alterations in cardiovascular function and marginal affections of
gass exchange can be demonstrated already at rest. They may be considered as
contributing factors to orthostatic and exercise intolerance observed after
space flight.
Authors-------- ten Harkel AD. Baisch F. Karemaker JM.
Institution----- Department of Medicine, Univ. of Amsterdam Academic Medical
Centre, Netherlands.
Title------------ Increased orthostatic blood pressure variability after
prolonged head down tilt.
Source---------Acta Physiologica Scandinavica. Supplementum. 604:89-99,
1992
Abstract-------The effect of simulated weightlessness on orthostatic blood
pressure regulation was evaluated with passive 70 degrees head up tilt (HUT)
after 10 days of six degree head down tilt (HDT). Six healthy male
volunteers were studied. Continuous recording of finger blood pressure (BP)
was obtained non invasively with a Finapress TM edice. Instantaneous heart
rate (HR) was derived from the electrocardiogram. To Quantify orthostatic BP
variability, a fast fourier transform (FFT) of the beat by beat BP-and
RR-interval values was performed. Control HR before HUT after the 10-day HDT
period was increased, probably due to an arousal state of the test subjects.
The change in BP induced by HUT was not influenced by 10 days HDT, in
contrast to the HR rise which increased from 24 + /-2 Beats /min to 41 +/-7
beats/min (p less than 0.05). After HDT the total variance can be ascribed
to BP oscillations with a frequency of around 0.1Hz. In three subjects
transient HR decelerations during HUT after HDT were observed. Analysis of
the relationship between BP and HR in the transients showed that each HR
decrease was preceded by a BP increase above normal, these HR decelerations
seemed therefore, to be an effect of the vagal part of the arterial
baroreflex and did not necessarily signal an impending vasovagal syncope.
The present study indicates that although 10 days of HDT did not influence
absolute blood pressure ,responses to 70 degrees HUT, BP was maintained by
an increased sympathetic activity, reflected by an increased HR response and
an augmented variance in BP around 0.1Hz.
Authors--------Lathers CM. Charles JB.
Institution----- NASA/Johnson Space Centre, Space Biomedical Research
Institute, Houston, Texas.
Title------------Orthostatic hypotension in patients, bed rest subjects, and
astronauts. [review]
Source---------Journal of Clinical pharmacology. 34(5) ; 403-17, 1994 May.
Abstract-------Orthostatic hypotension after even short space flights has
affected a significant number of astronauts. Earlier treatment used oral
sympathomimetic ephedrine hydrochloride alone or with Headup bed rest.
Authors--------Grigoriev AT. Morukov BV. Vorobiev DV.
Institution----- Institute of Biomedical Problems, Ministry of Health,
Moscow, Rusia.
Title------------ Water and electrolyte studies during long term missions
onboard the space stations SALUT and MIR. [Reveiw]
Source---------Clinical Investigator. 72(3):169-89, 1994 Feb.
Abstract-------This contribution summarises the results of investigations of
water-electrolyte metabolism and its hormonal regulation conducted in
cosmonauts who performed long term space flights (from 18 to 366 days)
aboard the space stations SALUT and MIR and compares them with the results
obtained during various NASA flights. The role of the kidneys in ion
metabolism regulation was assessed by various salt-load tests before and
after flights. In addition, the results of a five year long space flight and
of medical experiments performed during the 237 day-and 241 day missions by
the physicians and cosmonaut researchers Atkov and Polyakov are reviewed in
detail. In spite of interindividual variations, metabolic, and endocrine
studies during prolonged space flights showed a reduction in body mass,
usually with a reduction in body water and electrolytes and considerable
changes in hormone concentrations and urinary hormone excretion. These
changes reflect the process of extended adaptation to a new environment. It
is likely that shifts in electrolyte metabolism in weightlessness are
primarily due to metabolic changes, that diminish the tissue ability for
ion retention, and to concomitant changes in the endocrine status. The
postflight examinations revealed changes in fluid-electrolyte metabolism and
in the function of the kidneys which indicated a hypohydration status and a
stimulation of hormonal systems responsible for homeostasis in order to
readapt to the normal gravitation . Postflight decline in osmotic
concentration of urine in cosmonauts was accompanied by an altered response
to antidiuretic hormone and was probably caused by changes in the functional
state of the kidneys. We conclude that detailed knowledge of the alterations
in water-electrolyte metabolism and its hormonal regulation on different
stages of space flight are important prerequisites for the development of
countermeasures to space deconditioning and thus for increased human
efficiency in space.
Authors--------Krasnov IB.
Institution----- Institute of Biomedical Problems, Moscow, Russia.
Title------------ Gravitational neuromorphology. [review]
Source---------Advances in Space Biology and Medicine. 4:85-110, 1994.
Abstract-------This review shows that morphological studies of the central,
peripheral and autonomic nervous system of animals exposed to altered
gravity yield data which are extremely significant for our understanding of
the mechanisms of adaptation of the nervous system, and of the mammalian
organism as a whole, to increased and decreased loading Neuromorphological
studies, correlating structure and function, indicate a decreased activity
in weightlessness for spinal ganglia neurons of the hypothalamic nuclei
producing arginine vasopressin and growth hormone releasing factor.
Structural changes of the somatosensory cortex and spinal ganglia suggest a
decreased afferant flow to the somatosensory cortex in microgravity. The
results characterise the mechanisms of structural adaptation to a decreased
afferant flow in microgravity by the neurons in the hemisphere cortex and
brain stem nuclei. There is also morphological evidence for an increased
sensitivity of the otolith apparatus and for the development of a
hyponoradrenergic syndrome in weightlessness. These studies have shown that
both microgravity and the simulation of microgravity effects by tail
suspension -induced structural changes in the large neurons of lumbar spinal
ganglia and motoneurons of the lumbar spinal cord, which occur under
conditions of nerve cell hypoactivity. The structural changes, and
consequently the development of neuron hypoactivity, are expressed more
extensively after microgravity than after tail suspension for the same
length of time. The influences of microgravity and hypergravity on animals
is expressed by opposing changes in nervous tissue structure in the spinal
ganglia, spinal cord, and nodulus of cerebellar vermis. These changes
indicate neuron hypoactivity under microgravity and neuron hyperactivity
under (2 G.) Morphological assessment of the functional state of other
structures of the brain under hypergravity will require further study. Can
all structural changes which occurr in nerve tissue under microgravity or
under hypergravity be explained on the basis of increased or decreased
activity of its structural elements? The Presently available data regarding
the correlation of structure and functional state of cells in brain and
spinal cord suggest an affirmative answer. Ultrastructural studies of the
nodular cortex of the cerebellum in rats after different duration of space
flights provide what appears to be a convincing example. However, it should
be pointed out that the criteria for the morphological assessment of the
functional state of single nerve cells will certainly be different from
those groups of neurons connected in a nerve cell network.
[references: 69]
Authors--------Gerstenbrand F. Muigg A.
Institution----- Universitatsklinik fur Neurologie, Innsbruck.
Title------------Raumfahrtmedizin und life sciences in space
Source---------Weiner Medizinische Wachenschrift. 143(23-24):582-4, 1993
Abstract-------These results are important for medical application on
patients. In real microgravity, disturbances of motor performances,
co-ordination of movements, accuracy of movements, muscle function as well
as structural changes in muscles, Spinal reflexes and the control of
vestibular system on eye movements are also afflicted. Higher brain
functions, especially associative reactions, critical abilities, memory, as
well as high control, geometric and arithmetic analysis and its
reproduction, at last speech production, writing and reading are decreased,
vegetative disorders, bone decalcification, primary muscular atrophy occurr
as well as changes in sleepwake regulation and diminishing of vigility.
Disturbances of blood and body fluid circulation are further effects of
manned space flight.
Several problems of space adaptation can be studied using the bed rest model
in special labartories.
Authors--------Cogoli A. Bechler B. Cogoli-Greuter M. Criswell SB.
Joller H. Joller P. Hunzinger E. Muller O.
Institution------Space Biology Group, ETH Technopark, Zurich, Switzerland.
Title------------Mitogenic signal transduction in T lymphocytes in
microgravity.
Source---------Journal of Leukocyte Biology. 53(5):569-75, 1993 May.
Abstract-------The activation of cononavalin A Con A of human peripheral
blood lymphocytes (PBLs) in the presence of monocytes as accessory cells was
investigated in cultures exposed to microgravity conditions in Spacelab.
Activation of T cells was measured as incorporation of [3H]thymidine into
DNA, secretion of interleukin-2 (IL-2), and interferon -gamma, and
expression of IL-2 receptors. Whereas, as discovered in earlier experiments,
the activation of re-suspended T cells is strongly inhibited, activation of
cells attached to microcarrier beads is more than doubled in microgravity.
The results suggest that the depression of the activation in re-suspended
cells may be attributed to a malfunction of monocytes acting as accessory
cells. In fact, although the ultrastructure of re-suspended monocytes is not
altered in microgravity, the secretion of IL-1 is strongly inhibited. Our
data suggests that (1) IL-2 is produced independantly of IL-1, (2) IL-1
production is triggered only when monocytes (and lymphocytes?) adhere to
microcarriers, (3) the expression of IL-2 receptors depends on IL-1, and
(4) provided sufficient IL-1 is available, activation is enhanced in
microgravity. Finally, cultures of re-suspended PBLs and monocytes in
microgravity constitute a complete and natural system in which monocytes are
not operational. This may be useful for studies of the role of accessory
cells and celll-cell interactions in T lymphocyte activation.
Authors--------Le Blanc A. Rowe R. Schneider V. Evans H. Hedrick T.
Institution----- Baylor College of Medicine, Houston, TX 77030, USA.
Title------------Regional muscle loss after short duration spaceflight.
Source---------Aviation Space & Environmental Medicine, 66(12):1151-4, 1995
Dec
Abstract-------BACGROUND : Muscle strength and limb girth measurements
during Skylab and Appollo missions suggest that loss of muscle mass may
occur as a result of spaceflight. Extended duration spaceflight is important
for the economical and practical use of space. The loss of muscle mass
during spaceflight is a medical concern for long duration flights to the
planets, or extended stays aboard space stations. Understanding the extent
and temporal relationships of muscle is important for the development of
effective spaceflight countermeasures. HYPOTHESIS. We hypothesized that
significant measurable changes in muscle volume would occur in Shuttle crew
members following 8 days of weightlessness. METHODS : MRI was used to obtain
the muscle volumes of the calf, thigh and lower back before and after the
ATS-47 Shuttle mission. RESULTS : Statistical analysis demonstrated that the
soleus-gastrocnemius (-6.3%), anterior calf (-3.9%), hamstrings (-8.3%),
Quadriceps (-6.0%) and intrinsic back (=10.3%) Muscles were decreased, p <
0.05, compared to baseline, 24 hours after landing. At 2 weeks post
recovery, the hamstrings and intrinsic lower back muscles were still below
baseline, p < 0.05.
CONCLUSIONS : These results demonstrate that even short duration spaceflight
can result in significant muscle attrophy.
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