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PubMed2002

Effect of physical feed restriction during rearing on Large White turkey breeder hens: 3. Body and carcass composition.

Large White turkey breeder hens were used to evaluate the effect of three different levels of physical feed restriction on subsequent body and carcass composition. The four feed treatments were 1) ad libitum fed throughout the study (CC), 2) feed restricted from 16 to 24 wk (CR), 3) feed restricted from 3 to 16 wk (RC), and 4) feed restricted from 3 to 24 wk (RR). Feed restriction was implemented so that RC and RR hens achieved a 45% reduction in BW compared to CC hens at 16 wk. From 16 to 24 wk, feed was allotted to RR and CR hens to maintain a slight increase in BW. At the completion of each restriction period, hens were gradually returned to ad libitum feeding. At 30 wk, hens were photostimulated for a 20-wk summer season egg production cycle. Restricted fed hens had increased moisture levels at 16 and 30 wk and decreased fat levels at 16, 30, 39, and 54 wk (P < or = 0.05). Absolute and relative weights of the pectoralis major muscle were greater in hens fed ad libitum through 43 wk (P < or = 0.05). There were no differences in the number of maturing yellow follicles due to treatment. However, restricted fed hens had higher peak egg production during early lay but decreased subsequent and cumulative egg production. Changes in egg production were associated with changes in breast muscle weight. Prolactin levels were greater in hens in-production compared to hens out-of-production; however, there were no differences due to feed treatment. In conclusion, further research on quantitative feed-restriction programs, which result in body weight reductions as described in this study, should address specific physiological and nutritional requirements and not be implemented as general programs.

Adipose Tissue↗

PubMed2003

Effect of early feed restriction on reproductive performance in Japanese quail (Coturnix coturnix japonica).

Reproductive performance of quail (Coturnix coturnix japonica) was evaluated following feed restriction (100, 85, and 70% of ad libitum) between 2 to 5 wk of age with three replicates of 12, 2-wk-old chicks per replicate. Body weight, feed conversion, and leucocyte distribution were measured during feed restriction. After experimental feed treatment, BW, age at first egg, egg production, fertility, hatchability, and embryonic mortality were evaluated from five replicates of two females and one male per treatment. Feed-restricted female chicks had lower BW from 3 to 5 wk of age, but male weights were depressed only during the most severe restriction at 4 and 5 wk. No treatment differences were observed among BW within a sex from 6 to 13 wk. Body weights at first egg were significantly heavier for females fed 70% ad libitum than for birds on other treatments. Fertility, age at first egg, feed conversion, egg production, and egg weight were unaffected by feed restriction. Although hatchability was unaffected by feed restriction, percentage of late dead and total dead embryos were significantly reduced in eggs from restricted quail. Thirty quail fed 70% of ad libitum control intake had significantly increased egg specific gravity. Feed restriction increased the percentage of heterophils and basophils and the heterophil/lymphocyte ratio, whereas the percentage of lymphocytes and eosinophils decreased. Feed can be restricted to 85 or 70% of ad libitum feed intake from 2 to 5 wk of age without detrimentally affecting reproductive parameters between 6 to 13 wk of age.

Aging↗

PubMed2004

Effect of maternal nutrient restriction in sheep on the development of fetal skeletal muscle.

The effect of maternal nutrient restriction on mTOR (mammalian target of rapamyosin) signaling and the ubiquitin system as well as their possible relation to growth of fetal muscle was determined. Ewes were fed to 50% (nutrient-restricted) or 100% (control-fed) of total digestible nutrients (National Research Council requirement) from Days 28 to 78 of gestation. Ewes were killed at Day 78 of gestation, and the fetal longissimus dorsi muscle was sampled for the measurement of mTOR, ribosomal protein S6, AMP-activated protein kinase (AMPK), calpastatin, and protein ubiquitylation. No difference was observed in the content of mTOR and ribosomal protein S6, but the phosphorylation of mTOR at Ser2448 and ribosomal protein S6 at Ser235/336 were reduced (P <0.05) in muscle from nutrient-restricted fetuses. Because phosphorylation of mTOR and ribosomal protein S6 up-regulates protein translation, these results show that nutrient restriction down-regulates protein synthesis in fetal muscle. No difference in AMPK activity was detected. The lack of difference in calpastatin and ubiquitylized protein content shows that nutrient restriction did not affect degradation of myofibrillar proteins in fetal muscle. Fetuses of nutrient-restricted ewes showed retarded development of muscles and skeleton. Muscle from nutrient-restricted fetuses contained fewer secondary myofibers than muscle from control fetuses, and the average area of fasciculi was smaller (P <0.05). The decreased number of secondary myofibers in nutrient-restricted fetuses may result from the decreased mTOR signaling. Lower activation of mTOR signaling in nutrient-restricted fetuses may reduce the proliferation of myoblasts and, thus, reduce the formation of secondary myofibers. This decrease in secondary myofibers in fetuses may predispose fetuses to metabolic diseases, such as diabetes and obesity, in their postnatal lives.

Animal Nutritional Physiological Phenomena↗

PubMed1992

Characteristics of the carotid baroreflex in man during normal and flow-restricted exercise.

Eight subjects were studied in the supine position at rest, during normal dynamic leg exercise (control exercise) and with blood-flow restriction in the working legs (flow-restricted exercise). Graded muscle blood-flow restriction was accomplished by applying a supra-atmospheric pressure of 50 mmHg to the working legs. During incremental-load exercise, flow restriction reduced exercise performance and peak heart rate by 36% and 13%, respectively. The function of the cardiac branch of the carotid baroreflex was studied over its full operational range, at rest and during constant-load control and flow-restricted exercise, by measuring R-R intervals during application of pulse-synchronous graded pressures (40 to -65 mmHg) in a neck-chamber device. Heart rate and arterial pressure were higher during flow-restricted than control exercise, indicating that the flow restriction activated the muscle chemoreflex. Raising the carotid transmural pressure (systolic arterial pressure minus neck-chamber pressure) was accompanied by increasing R-R intervals in all conditions. The set point (point of baseline carotid transmural pressure and R-R interval) coincided with the midportion of the pressure-response curve at rest and with the threshold point of the curve during exercise. The maximal rate of change in relative R-R intervals and the corresponding carotid transmural pressure range were higher during control exercise than at rest and highest during flow-restricted exercise, indicating that exercise and especially flow-restricted exercise increased carotid baroflex sensitivity, and shifted the carotid baroreflex optimal buffering range to higher pressures. The results suggest that the carotid baroflex attenuates exercise heart rate increases mediated by the muscle chemoreflex and/or by central command.

Adult↗

PubMed2005

Type III restriction is alleviated by bacteriophage (RecE) homologous recombination function but enhanced by bacterial (RecBCD) function.

Previous works have demonstrated that DNA breaks generated by restriction enzymes stimulate, and are repaired by, homologous recombination with an intact, homologous DNA region through the function of lambdoid bacteriophages lambda and Rac. In the present work, we examined the effect of bacteriophage functions, expressed in bacterial cells, on restriction of an infecting tester phage in a simple plaque formation assay. The efficiency of plaque formation on an Escherichia coli host carrying EcoRI, a type II restriction system, is not increased by the presence of Rac prophage-presumably because, under the single-infection conditions of the plaque assay, a broken phage DNA cannot find a homologue with which to recombine. To our surprise, however, we found that the efficiency of plaque formation in the presence of a type III restriction system, EcoP1 or EcoP15, is increased by the bacteriophage-mediated homologous recombination functions recE and recT of Rac prophage. This type III restriction alleviation does not depend on lar on Rac, unlike type I restriction alleviation. On the other hand, bacterial RecBCD-homologous recombination function enhances type III restriction. These results led us to hypothesize that the action of type III restriction enzymes takes place on replicated or replicating DNA in vivo and leaves daughter DNAs with breaks at nonallelic sites, that bacteriophage-mediated homologous recombination reconstitutes an intact DNA from them, and that RecBCD exonuclease blocks this repair by degradation from the restriction breaks.

Bacteriophage lambda↗

PubMed2005

Restriction of feline immunodeficiency virus by Ref1, Lv1, and primate TRIM5alpha proteins.

The Ref1 and Lv1 postentry restrictions in human and monkey cells have been analyzed for lentiviruses in the primate and ungulate groups, but no data exist for the third (feline) group. We compared feline immunodeficiency virus (FIV) to other restricted (human immunodeficiency virus type 1 [HIV-1], equine infectious anemia virus [EIAV]) and unrestricted (NB-tropic murine leukemia virus [NB-MLV]) retroviruses across wide ranges of viral inputs in cells from multiple primate and nonprimate species. We also characterized restrictions conferred to permissive feline and canine cells engineered to express rhesus and human TRIM5alpha proteins and performed RNA interference (RNAi) against endogenous TRIM5alpha. We find that expression of rhesus or human TRIM5alpha proteins in feline cells restricts FIV, impairing pseudotyped vector transduction and viral replication, but rhesus TRIM5alpha is more restricting than human TRIM5alpha. Notably, however, canine cells did not support restriction by human TRIM5alpha and supported minimal restriction by rhesus TRIM5alpha, suggesting that these proteins may not function autonomously or that a canine factor interferes. Stable RNAi knockdown of endogenous rhesus TRIM5alpha resulted in marked increases in FIV and HIV-1 infectivities while having no effect on NB-MLV. A panel of nonprimate cell lines varied widely in susceptibility to lentiviral vector transduction, but normalized FIV and HIV-1 vectors varied concordantly. In contrast, in human and monkey cells, relative restriction of FIV compared to HIV-1 varied from none to substantial, with the greatest relative infectivity deficit for FIV vectors observed in human T-cell lines. Endogenous and introduced TRIM5alpha restrictions of FIV could be titrated by coinfections with FIV, HIV-1, or EIAV virus-like particles. Arsenic trioxide had complex and TRIM5alpha-independent enhancing effects on lentiviral but not NB-MLV infection. Implications for human gene therapy are discussed.

Animals↗

PubMed1992

Effect of acute food restriction on pulmonary growth and protein turnover in preterm guinea pigs.

The effects of food restriction on the growth and protein turnover of the immature lung were investigated. Preterm guinea pigs, delivered by cesarean section at 65 days gestation (term = 68 days), were given free access to a lactating dam or restricted from feeding for 48 h. Food restriction resulted in significantly reduced body and lung (P less than 0.05) weight compared with fed controls. The rate of pulmonary protein synthesis determined in vivo was reduced by 33% in the food-restricted pups (28.9 +/- 10.2 vs. 19.4 +/- 4.5%, P less than 0.05 for control and food-restricted pups, respectively), whereas the calculated rate of protein breakdown remained unchanged. The inhibition of protein synthesis was accounted for by a 36% decrease in ribosomal efficiency (11.03 +/- 2.61 vs. 7.04 +/- 1.26%, P less than 0.01 for control and food-restricted pups, respectively), whereas ribosomal capacity was unaltered. Polyribosomal analysis indicated an increase in the proportion of RNA present in polysomes and a fall in the free monomer pool (26%), suggesting that food restriction blocked translation by reducing the rate of peptide chain elongation. This finding was confirmed by the analysis of ribosome transit times, which indicated a significant increase in the elongation rate in the lungs from food-restricted pups (0.51 +/- 0.11 vs. 0.94 +/- 0.19 min, P less than 0.05 for control and food-restricted pups, respectively). These results imply that nutrient supply plays an important role in protein deposition and hence growth and repair capacity of the immature lung.

Animals↗

PubMed1992

Long-term calorie restriction enhances baroreflex responsiveness in Fischer 344 rats.

Diet influences many aspects of cardiovascular function. Restriction of caloric intake represents a major nonpharmacological means of reducing blood pressure. The aim of the present work was to determine the effects of long-term calorie restriction on mean arterial pressure (MAP) and baroreflex responsiveness of the conscious, normotensive, nonobese Fischer 344 male rat. From 6 wk of age rats ate either ad libitum or 60% of the amount consumed by those eating ad libitum. Calorie restriction had no effect on MAP of rats 12-14 mo of age; the MAP for the ad libitum fed and calorie-restricted groups were 114.6 +/- 1.6 and 111.6 +/- 0.8 mmHg, respectively. Basal heart rate (HR), however, was reduced from 396 +/- 6 beats/min in the libitum-fed group to 333 +/- 5 beats/min in the calorie-restricted group. Administration of sodium nitroprusside (SNP) (both as bolus and constant infusion) and phenylephrine (PE) (bolus alone) elicited tachycardia and bradycardia in both groups. The calorie-restricted group exhibited greater baroreflex responsiveness to hypotensive stress than did the ad libitum-fed group. For constant infusion of SNP, the baroreflex gain of the calorie-restricted group (-5.43 +/- 0.56 beats.min-1.mmHg-1) was significantly greater than that of the ad libitum-fed group (-2.14 +/- 0.19 beats.min-1.mmHg-1). Bolus injections of SNP elicited similar results. Calorie restriction only minimally altered the baroreflex responsiveness to hypertensive stress elicited by bolus injections of PE, although the relationship between HR and MAP was shifted to the left in the calorie-restricted group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2004

Effects of dietary calcium restriction and acute exercise on the antioxidant enzyme system and oxidative stress in rat diaphragm.

Calcium deficiency is considered to increase intracellular calcium level; thus the aim of the current study was to elucidate whether dietary calcium restriction enhanced exercise-induced oxidative stress in rat diaphragm. Twenty male Wistar rats were randomly assigned to either a control group or a group subjected to 1 mo of calcium restriction. In addition, each group was subsequently subdivided into rested or acutely exercised group. Dietary calcium restriction significantly (P < 0.05) upregulated the activities of manganese-superoxide dismutase (Mn-SOD), copper-zinc-superoxide dismutase (Cu-Zn-SOD), and glutathione peroxidase (Gpx) but not catalase. Acute exercise, in addition to calcium restriction, decreased both SOD isoenzymes in the diaphragm of calcium-restricted rats (P < 0.05). On the other hand, calcium restriction resulted in increased Gpx mRNA expression (P < 0.05). In control rats, acute exercise significantly (P < 0.05) increased the expressions of both SOD mRNAs, whereas in the calcium-restricted rats, it increased that of Mn-SOD mRNA (P < 0.05) but decreased that of Gpx mRNA (P < 0.05). Furthermore, reactive carbonyl derivative, a marker of protein oxidation, was significantly greater in the calcium-restricted rats than in the control rats after acute exercise (P < 0.05). The results suggest that antioxidant enzymes in rat diaphragm were upregulated in response to an increased oxidative stress by dietary calcium restriction but that upregulation is not enough to cope with exercise-induced further increase of oxidative stress.

Animals↗

PubMed2001

Parasite infection and caloric restriction induce physiological and morphological plasticity.

To investigate the effects of parasitism and caloric restriction on morphology (body composition, organ mass) and physiology (resting metabolism, intestinal glucose transport capacity), we gave laboratory mice intestinal parasites (Heligmosomoides polygyrus, Nematoda), 30% caloric restriction, or both. Calorically restricted mice had smaller body mass, enhanced glucose transport capacity, and lower resting metabolism than ad libitum-fed mice. Parasitized mice maintained body mass, had diminished intestinal glucose transport capacity, and greater resting metabolism than unparasitized mice. Parasitized, calorically restricted mice had smaller organ masses than parasitized, ad libitum-fed mice and did not increase their glucose uptake rate as much as unparasitized, calorically restricted mice. There was a significant interaction between caloric restriction and parasite status for morphological variables but not for physiological variables. Knowing the types of phenotypic changes that occur with simultaneous parasitism and caloric restriction will provide insight into understanding human helminthiasis in food-restricted communities and also how wild animals cope with environments where parasitism and seasonal food restriction are common.

Animals↗

PubMed1991

Interaction between exercise and food restriction: effects on longevity of male rats.

Male rats that exercise in running wheels have a longer average survival than freely eating sedentary controls but, in contrast to food-restricted sedentary controls of the same weight, show no extension of maximal life span (J. Appl. Physiol. 59: 826-831, 1985). To test the possibility that exercise may counteract a life-extending effect of decreased availability of energy for certain biological processes such as cell proliferation, we examined the combined effects of exercise and food restriction on longevity of male rats. As before, wheel running improved average length of life, 978 +/- 172 vs. 875 +/- 175 (SD) days, for the sedentary controls (P less than 0.01) without increasing maximal life span. Paired-weight controls, food restricted (approximately 30% below ad libitum) to weight the same as the runners, showed increases in both average (1,056 +/- 144 days) and maximal life span. Food-restricted runners, with intake restricted to the same extent (approximately 30%), had an increased mortality rate over the first approximately 50% of their survival curve up to approximately 900 days of age; their average life span (995 +/- 226) was similar to that of the control group of runners and shorter than that of their paired-weight food-restricted sedentary controls (1,088 +/- 159 days, P less than 0.05). However, after approximately 900 days of age the food-restricted runners' survival became similar to that of the food-restricted sedentary groups, with a comparable increase in maximal life span. Thus the exercise did not counteract the increase in maximal life span induced by food restriction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1995

Right ventricular diastolic function 15 to 35 years after repair of tetralogy of Fallot. Restrictive physiology predicts superior exercise performance.

BACKGROUND: We have shown previously that transient right ventricular restriction after tetralogy of Fallot repair prolongs postoperative course. This is a prospective study of right ventricular diastolic performance in late follow-up patients. METHODS AND RESULTS: We studied biventricular function, using Doppler echocardiographic examination. Pulmonary arterial, tricuspid, and mitral valves and superior vena cava Doppler spectrals were obtained in 41 patients (mean age, 28.8 years), 15 to 35 years (mean, 23.6) after complete repair of tetralogy of Fallot. Patients were considered to have evidence of right ventricular restriction if antegrade diastolic flow was detected in the main pulmonary artery, coinciding with atrial systole (A wave), throughout the respiratory cycle. Exercise function was measured by graded treadmill testing with respiratory mass spectrometry. Three patients were excluded because of pulmonary outflow obstruction (Doppler gradient > 40 mm Hg) or residual intracardiac shunts. Of the 38 patients, 37 were in sinus rhythm. Twenty (52.6%) had definite evidence of restriction with an A wave in the pulmonary artery, augmented during inspiration. In all 20 cases, there was superior vena caval flow reversal with atrial systole. Both inspiratory and expiratory transtricuspid E-wave deceleration time was significantly shorter in the restrictive group (P < .003 and P < .03, respectively). All patients had Doppler evidence of pulmonary regurgitation, but its duration was shorter in the restrictive group (P < .01) during inspiration. Cardiothoracic ratio was significantly lower in the restrictive group (P < .01), suggesting less severe pulmonary regurgitation. Both restrictive and nonrestrictive groups had reduced exercise MVO2 compared with healthy age- and sex-matched control subjects, but those with restrictive physiology had significantly better maximum oxygen uptake than the nonrestrictive group (P < .001). CONCLUSIONS: Isolated right ventricular restriction late after tetralogy of Fallot repair is common. Although it reflects abnormal hemodynamics, the A wave contributes to forward pulmonary arterial flow and shortens the duration of pulmonary regurgitation. Consequently, there is less cardiomegaly and improved exercise performance in those patients.

Adolescent↗

PubMed2004

Effects of the group I metabotropic glutamate receptor agonist, DHPG, and injection stress on striatal cell signaling in food-restricted and ad libitum fed rats.

BACKGROUND: Chronic food restriction augments the rewarding effect of centrally administered psychostimulant drugs and this effect may involve a previously documented upregulation of D-1 dopamine receptor-mediated MAP kinase signaling in nucleus accumbens (NAc) and caudate-putamen (CPu). Psychostimulants are known to induce striatal glutamate release, and group I metabotropic glutamate receptors (mGluR) have been implicated in the cellular and behavioral responses to amphetamine. The purpose of the present study was to evaluate whether chronic food restriction increases striatal MAP kinase signaling in response to the group I mGluR agonist, DHPG. RESULTS: Western immunoblotting was used to demonstrate that intracerebroventricular (i.c.v.) injection of DHPG (500 nmol) produces greater activation of ERK1/2 and CREB in CPu and NAc of food-restricted as compared to ad libitum fed rats. Fos-immunostaining induced by DHPG was also stronger in CPu and NAc core of food-restricted relative to ad libitum fed rats. However, i.c.v. injection of saline-vehicle produced greater activation of ERK1/2 and CREB in CPu and NAc of food-restricted relative to ad libitum fed rats, and this difference was not seen when subjects received no i.c.v. injection prior to sacrifice. In addition, although DHPG activated Akt, there was no difference in Akt activation between feeding groups. To probe whether the augmented ERK1/2 and CREB activation in vehicle-injected food-restricted rats are mediated by one or more GluR types, effects of an NMDA antagonist (MK-801, 100 nmol), AMPA antagonist (DNQX, 10 nmol), and group I mGluR antagonist (AIDA, 100 nmol) were compared to saline-vehicle. Antagonist injections did not diminish activation of ERK1/2 or CREB. CONCLUSIONS: These results indicate that a group I mGluR agonist induces phosphorylation of Akt, ERK1/2 and CREB in both CPu and NAc. However, group I mGluR-mediated signaling may not be upregulated in food-restricted rats. Rather, a physiological response to "i.c.v. injection stress" is augmented by food restriction and appears to summate with effects of the group I mGluR agonist in activating ERK1/2 and CREB. While the augmented cellular response of food-restricted rats to i.c.v. injection treatment represents additional evidence of enhanced CNS responsiveness in these subjects, the functional significance and underlying mechanism(s) of this effect remain to be elucidated.

Animals↗

PubMed1996

Parenchymal scarring is associated with restrictive spirometric defects in patients with chronic thromboembolic pulmonary hypertension.

UNLABELLED: The finding of a restrictive pulmonary defect may divert clinicians from considering the diagnosis of chronic thromboembolic pulmonary hypertension because lung volumes are usually normal in this disorder. We have, however, encountered a significant number of these patients with reduced lung volumes. Furthermore, we have observed many patients who have developed parenchymal scars and/or pleural thickening. To determine whether such findings are associated with lung volume restriction, we analyzed patients evaluated at our institution for chronic thromboembolic pulmonary hypertension over a 20-month period in whom thoracic high-resolution CT scans and pulmonary function testing had been performed. Patients with obstructive or restrictive lung disease from another cause were excluded. We compared the presence of lung restriction (total lung capacity below 80% of predicted) with the extent of parenchymal scarring, pleural thickening, and pulmonary artery diameter on CT scans. Of 191 patients evaluated, 51 met criteria for entry. Eleven patients (22%) had lung restriction. Parenchymal scarring was highly associated with lung restriction (p = 0.01). Neither pleural thickening (p = 0.08) nor pulmonary artery diameter (p = 0.80) was associated with lung restriction. CONCLUSIONS: A significant number of patients with chronic thromboembolic pulmonary hypertension may have restrictive lung defects. The restriction may be due to parenchymal scarring.

Adult↗

PubMed2004

Alterations in placental 11 beta-hydroxysteroid dehydrogenase (11 betaHSD) activities and fetal cortisol:cortisone ratios induced by nutritional restriction prior to conception and at defined stages of gestation in ewes.

In the placenta, cortisol is inactivated by NADP(+)- and NAD(+)-dependent isoforms of 11beta-hydroxysteroid dehydrogenase (11betaHSD). Decreased placental 11betaHSD activities have been implicated in intrauterine growth restriction (IUGR) and fetal programming of adult diseases. The objective of this study was to investigate whether placental 11betaHSD activities and fetal plasma cortisol:cortisone ratios could be affected by nutritional restriction of ewes (70% maintenance diet) throughout gestation, for specific stages of gestation, or prior to mating. Chronic nutritional restriction from day 26 of gestation onwards decreased NAD(+)-dependent 11betaHSD activities by 52 +/- 4% and 45 +/- 6% on days 90 and 135 of gestation respectively. Although the decreases in enzyme activities were associated with fetal IUGR, the cortisol:cortisone ratio in fetal plasma was unaffected by chronic nutritional restriction throughout pregnancy. Nutritional restriction confined to early (days 26-45), mid- (days 46-90) and late gestation (days 91-135), or the 30 days prior to mating, had no significant effect on NAD(+)-dependent, placental 11betaHSD activities, nor was there evidence of IUGR. However, nutritional restriction at each stage of pregnancy and prior to mating was associated with significant decreases in the fetal plasma cortisol:cortisone ratio (3.2 +/- 0.7 in control fetuses; 1.0 to 1.6 in fetuses carried by nutritionally restricted ewes). We conclude that nutritional restriction of pregnant ewes for more than 45 consecutive days can significantly decrease NAD(+)-dependent placental 11betaHSD activities in association with IUGR. While the cortisol:cortisone ratio in fetal plasma is sensitive to relatively acute restriction of nutrient intake, even prior to mating, this ratio does not reflect direct ex vivo measurements of placental 11betaHSD activities.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed2005

The role of patient restrictions in reducing the prevalence of early dislocation following total hip arthroplasty. A randomized, prospective study.

BACKGROUND: It is currently unknown whether functional restrictions following total hip arthroplasty can reduce the prevalence of early postoperative dislocation. Our hypothesis was that dislocation was more likely to occur in patients who were not placed on these restrictions. METHODS: We performed a prospective, randomized study to evaluate the role of postoperative functional restrictions on the prevalence of dislocation following uncemented total hip arthroplasty through an anterolateral approach. Of the 630 eligible consecutive patients, 265 patients (303 hips) consented to be randomized into one of two groups (the "restricted" group or the "unrestricted" group). The patients in both groups were asked to limit the range of motion of the hip to <90 degrees of flexion and 45 degrees of external and internal rotation and to avoid adduction for the first six weeks after the procedure. The patients in the restricted group were instructed to comply with additional hip precautions during the first six weeks postoperatively. Specifically, these patients were managed with the placement of an abduction pillow in the operating room before bed transfer and used pillows to maintain abduction while in bed; used elevated toilet seats and elevated chairs in the hospital, in the rehabilitation facility, and at home; and were prevented from sleeping on the side, from driving, and from being a passenger in an automobile. All patients were followed for a minimum of six months postoperatively. RESULTS: There was one dislocation in the entire cohort (prevalence, 0.33%). This dislocation occurred in a patient in the restricted group during transfer from the operating table to a bed with an abduction pillow in place. Patients in the unrestricted group were found to return to side-sleeping sooner (p < 0.001), to ride in automobiles more often (p < 0.026), to drive automobiles more often (p < 0.001), to return to work sooner (p < 0.001), and to have a higher level of satisfaction with the pace of their recovery (p < 0.001) than those in the restricted group. There was an additional expenditure of approximately $655 per patient in the restricted group. CONCLUSIONS: Total hip arthroplasty through an anterolateral approach is likely to be associated with a low dislocation rate. Removal of several restrictions did not increase the prevalence of dislocation following primary hip arthroplasty at our institution. However, it did promote substantially lower costs and was associated with a higher level of patient satisfaction as patients achieved a faster return to daily functions in the early postoperative period.

Adolescent↗

PubMed2006

Pulmonary responses to nutritional restriction and hyperoxia in premature rabbits.

OBJECTIVES: To analyze the effects of nutritional restriction and hyperoxia on lung weight and pulmonary morphometry in premature rabbits during the first 11 days of life. METHODS: New Zealand White rabbits were delivered by C-section at 28 days' gestational age and randomized into four groups: control diet and room air, control diet and hyperoxia (> or = 95% O2), nutritional restriction and room air and nutritional restriction and hyperoxia (> or = 95% O2). Nutritional restriction was achieved by reducing all nutrients by 30% in comparison with the control diet. Lung tissue slides were stained with hematoxylin-eosin, modified resorcin-orcein and picrosirius, before morphometric analysis was performed. RESULTS: From the fourth day onwards, less weight was gained by the nutritional restriction and hyperoxia group (p < 0.001), and from the sixth day on, by the nutritional restriction and room air group (p < 0.001), in comparison with their respective control groups. Nutritional restriction decreased alveoli number (p < 0.001) and collagen deposition (p < 0.001). Hyperoxia was responsible for reductions in number of alveoli (p < 0.001) and collagen deposition (p < 0.001), in addition to higher mean linear intercept values (p < 0.05) and thickening of alveolar septa (p < 0.001). When nutritional restriction was associated with hyperoxia, the reductions in number of alveoli (p < 0.001) and of collagen deposition (p < 0.001) intensified. CONCLUSIONS: Nutritional restriction intensified the changes of pulmonary architecture findings caused by hyperoxia, in particular through alterations to alveolarization and collagen deposition.

Animals↗

PubMed1997

Effects of restricted knee flexion and walking speed on the vertical ground reaction force during gait.

Although lower extremity immobilization, including restricted knee flexion, is commonly used in rehabilitation, the effect of angle of knee restriction and walking speed on the vertical ground reaction forces during gait is unclear. Force plate measurements were made on 36 healthy males walking at three different speeds when knee flexion was unrestricted and restricted to both 10 and 25 degrees. Analysis of variance and post hoc analyses showed significant increases in four characteristics of the vertical ground reaction force in the restricted leg and in two characteristics in the unrestricted leg during walking with restricted knee flexion. Loading rate and unloading rate for the restricted leg and peak force for both legs showed significant speed-knee flexion restriction interactions. At the fast walking speed, two significant differences were found between knee flexion restrictions of 10 and 25 degrees. The clinical implications of these findings are that restricted knee flexion during gait may significantly alter the forces applied to both lower limbs.

Adolescent↗