Percentage Change In Body Weight Research Articles

Food availability affects neural estrogen receptor immunoreactivity in prepubertal mice.

How underfeeding delays maturation of the central mechanisms affecting GnRH release at the onset of puberty, and why females are more sensitive to underfeeding than males are not well understood. We tested the hypothesis that the sexually dimorphic effects of underfeeding on GnRH release are mediated in part through the estrogen receptor (ER). We investigated the influence of underfeeding on the number of ER-immunoreactive (ER-ir) cells in the medial preoptic area (mPOA), ventromedial nucleus (VMN), and arcuate nucleus (ARH) of prepubertal CF-1 mice, neural areas known to influence GnRH release. In females, 7 days of underfeeding reduced detectable ER-ir cells in the mPOA and VMN, but not in the ARH. Also, we noted a direct relationship between the percent body weight change the last 24 h before perfusion and the numbers of ER-ir cells in the mPOA (r = 0.69; P = 0.0008) and VMN (r = 0.56; P = 0.01). In males, 17 days of underfeeding did not affect ER-ir cell numbers in any region. A subsequent investigation of the time course of alterations in ER immunoreactivity revealed that in female mice ER-ir cell numbers were reduced within 48 h of underfeeding in the mPOA, VMN, and ARH. ER-ir cell number was not changed in male mice. When female mice were underfed for 48 h and then refed, ER-ir cell numbers normalized by 24 h in the mPOA, VMN, and ARH. For the time-course experiments, the percent body weight change the last 24 h before perfusion and the number of ER-ir cells were related in the mPOA (r = 0.47; P < 0.001) and VMN (r = 0.49; P < 0.001), but not in the the ARH (r = 0.23; P < 0.12) in female mice, and in the mPOA (r = 0.66; P < 0.001), VMN (r = 0.33; P = 0.06), and ARH (r = 0.45; P = 0.007) in male mice. Thus, despite no significant change in ER-ir cell number in the male mice, there was a relationship between the percent body weight change during the last 24 h before perfusion and the number of ER-ir cells. We conclude that in male mice, correlation analyses between the percent body weight change before perfusion and ER-ir cell number may be a more sensitive marker of the metabolic condition at the time of perfusion. In female mice, underfeeding may stall puberty by reducing the number of ER-ir cells in brain areas important for signal transmission of GnRH release.

Food Availability Affects Neural Estrogen Receptor Immunoreactivity in Prepubertal Mice

How underfeeding delays maturation of the central mechanisms affecting GnRH release at the onset of puberty, and why females are more sensitive to underfeeding than males are not well understood. We tested the hypothesis that the sexually dimorphic effects of underfeeding on GnRH release are mediated in part through the estrogen receptor (ER). We investigated the influence of underfeeding on the number of ER-immunoreactive (ER-ir) cells in the medial preoptic area (mPOA), ventromedial nucleus (VMN), and arcuate nucleus (ARH) of prepubertal CF-1 mice, neural areas known to influence GnRH release. In females, 7 days of underfeeding reduced detectable ER-ir cells in the mPOA and VMN, but not in the ARH. Also, we noted a direct relationship between the percent body weight change the last 24 h before perfusion and the numbers of ER-ir cells in the mPOA (r = 0.69; P = 0.0008) and VMN (r = 0.56; P = 0.01). In males, 17 days of underfeeding did not affect ER-ir cell numbers in any region. A subsequent investigation of the time course of alterations in ER immunoreactivity revealed that in female mice ER-ir cell numbers were reduced within 48 h of underfeeding in the mPOA, VMN, and ARH. ER-ir cell number was not changed in male mice. When female mice were underfed for 48 h and then refed, ER-ir cell numbers normalized by 24 h in the mPOA, VMN, and ARH. For the time-course experiments, the percent body weight change the last 24 h before perfusion and the number of ER-ir cells were related in the mPOA (r = 0.47; P < 0.001) and VMN (r = 0.49; P < 0.001), but not in the the ARH (r = 0.23; P < 0.12) in female mice, and in the mPOA (r = 0.66; P < 0.001), VMN (r = 0.33; P = 0.06), and ARH (r = 0.45; P = 0.007) in male mice. Thus, despite no significant change in ER-ir cell number in the male mice, there was a relationship between the percent body weight change during the last 24 h before perfusion and the number of ER-ir cells. We conclude that in male mice, correlation analyses between the percent body weight change before perfusion and ER-ir cell number may be a more sensitive marker of the metabolic condition at the time of perfusion. In female mice, underfeeding may stall puberty by reducing the number of ER-ir cells in brain areas important for signal transmission of GnRH release.

Hyponatremia and weight changes in an ultradistance triathlon.

To describe the weight changes and the incidence of hyponatremia during an ultradistance triathlon in the athletes who attend medical care after the race. Descriptive research. The 1996 New Zealand Ironman Triathlon in which each athlete swam 3.8 km, cycled 180 km, and ran 42 km. Ninety-five athletes attending for medical care after the race were studied. One hundred sixty-nine athletes who did not attend for medical care were also weighed before and after the race. Weights were measured at race registration and on finishing the race. Whole-blood sodium concentration was measured in those athletes with clinical evidence of fluid or electrolyte disturbances. Weights were significantly decreased at the end of the race in the athletes seeking medical care (n = 48, mean % delta wt = -2.5%, p < 0.001) and also in the athletes who did not seek medical care (n = 169, mean % delta wt = -2.9%, p < 0.001). Seventeen percent of race starters sought medical attention. Dehydration accounted for 26% of primary diagnoses and hyponatremia for 9%. One athlete with hyponatremia (Na 130 mEq/L) is described who drank 16 L over the course of the race, with a weight gain of 2.5 kg. This is consistent with the hypothesis of fluid overload as the cause of his hyponatremia. Hyponatremia accounted for four of five admissions to the hospital after the race. An inverse relationship between postrace sodium concentrations and percentage change in body weight was observed (r = -0.63). Hyponatremia is an important risk to the health of athletes competing in an ultradistance triathlon, with fluid overload the likely aetiology.

Pregnancy-related changes in fat mass and total DDT in breast milk and maternal adipose tissue.

Changes in body fat mass during pregnancy and its effects on total DDT concentration i.e. the, sum of pp'-DDT (pp'-dichlorodiphenyltrichloroethane), and pp'-DDE (pp'-dichlorophenyldichloroethylene), in maternal milk and abdominal fat were studied in humans. Forty mothers that delivered by Caesarean section and chose to breast feed consented in providing samples (abdominal fat and breast milk) for determination of organochlorine pesticides. Constitutional variables, such as the number of children, and estimators of body fat mass, based on height and body weight (before and after pregnancy), were measured. Body mass index before and after pregnancy, as well as percent change in body weight, showed no significant difference in total DDT concentration in abdominal fat or breast milk. The only variable to significantly affect either body load of pesticides (abdominal fat) or its excretion (milk fat) was the number of children (p = 0.0117 and p = 0.0324, respectively). Correlation coefficients between DDT (in adipose tissue and milk fat) and variables related to body fatness (body mass index) were low and not significant. However, a close relationship was found between total DDT in adipose tissue and milk fat (r = 0.709; p = 0.0001).

Dilution kinetics of H(2)18O for the measurement of total body water in preterm babies in the first week after birth.

The aim of this study was to determine the kinetics of H(2)18O equilibration and elimination in preterm babies for the estimation of total body water. Thirteen, clinically stable, preterm babies of less than 32 weeks' gestation were studied in the first week after birth. Blood and urine samples were obtained for baseline measurement of 18O:16O ratio and 1 ml/kg of 10% H(2)18O (0.1 g/kg isotope) administered orally. Eleven blood samples were obtained over the next six hours and between one and four over the next 18 hours. During the same 24 hour period between three and eight urine samples were also obtained. The dilution space at zero time (volume of distribution or total body water) was estimated using double exponential curve fitting using all available points, from single samples and from linear regression on the log data using two or three samples. Equilibration time was variable and showed a significant correlation with percentage change in body weight from birth. For blood samples, the median time to equilibrium was 81 minutes (range 2 to 191). A plateau phase was not detected, with H(2)18O enrichment declining after the point of maximum enrichment. The median volume of distribution at time 0, based on double exponential curve fit analysis, was 859 ml/kg (range 755 to 995). The volume of distribution, estimated from linear regression on the log data using two serum samples obtained at three and six hours, approximated most closely to that based on exponential curve fit analysis with a median difference of -4 ml/kg (range -41 to 73). It was concluded that in most situations blood sampling at three and six hours may be acceptable. However, as equilibration time is variable and influenced by the state of expansion or depletion of body water compartments, when studying overhydration states, multiple sampling is advised in order to be certain that the elimination phase has been reached.

Differential effect of fasting on hypothalamic expression of genes encoding neuropeptide Y, galanin, and glutamic acid decarboxylase

The effect of caloric deprivation to stimulate hypothalamic neuropeptide Y (NPY) gene expression is hypothesized to represent a physiologically important adaptation in body weight homeostasis. To evaluate the specificity of this response, we used in situ hybridization histochemistry to measure hypothalamic expression of mRNA encoding NPY, galanin, and the two isoforms of glutamic acid decarboxylase (GAD 67 and GAD 65) in male Wistar rats either fed ad lib or deprived of food for 24 or 48 h. As expected, food deprivation for 24 and 48 h increased preproNPY mRNA levels in the arcuate nucleus by 43 ± 13% ( p = NS) and 127 ± 29% ( p < 0.05 vs. both fed and 24-h fasted groups) when compared to ad lib-fed controls, and hypothalamic preproNPY mRNA levels were significantly correlated to the percent change in body weight over the three groups of rats ( r = −0.72; p < 0.05). In contrast, no significant effects of either 24 or 48 h of fasting were observed on hypothalamic levels of preprogalanin, GAD 67, or GAD 65 mRNA, and no relationship between percent change in body weight and expression of any of these mRNA species could be demonstrated. In conclusion, fasting increases preproNPY mRNA levels in the arcuate nucleus but does not alter expression of other hypothalamic mRNA species pertinent to feeding behavior. This supports the hypothesis that stimulation of NPY gene expression represents an important component of the hypothalamic response to caloric deprivation.

Performance of Piezodorus guildinii on four species of Indigofera legumes

Piezodorus guildinii (Westwood) (Heteroptera: Pentatomidae), a major pest of soybean in South America, feeds on alternative legume hosts, and four species of Indigofera were tested. Nymphal survival was 88% on I. endecaphylla Jacq. (IE), 15% on I. suffruticosa Mill. (IS), 70% on I. hirsuta L. (IH) and 40% on I. truxilliensis H.B.K. (IT)). From stadia 2 through 5, fastest development (22 days) occurred on IE and IT, and the slowest (29 days) on IS. Fresh body weight at emergence was higher for nymphs fed on IE and IT. Adult survival of P. guildinii after 40 days, was greater than 70% on IT and IE, and less than 20% on IS. Females oviposited on all Indigofera species, but < 30% were observed to lay eggs on IS. Body weight gain during the first week was greater for adults feeding on IE and IH. Insects lost weight on IS; at the end of day 15 no differences in percent change in body weight, among the food plants tested, were observed. Field surveys conducted on IT and IS, the two most abundant species in northern Paraná, indicated a greater number of nymphs, adults, and egg masses on the former host. On both hosts P. guildinii was more abundant during April/May, after soybean harvest, suggesting movement of the populations from soybean to Indigofera.

Epidermal growth factor in the healing of corneal wounds, epidermal wounds, and partial-thickness scalds. A controlled animal study

The effects of the topical application and the intraperitoneal administration of epidermal growth factor (EGF) on the healing of epidermal wounds, and of partial-thickness scalds in rats and of corneal wounds in rabbits were evaluated. The parameters measured were the daily percentage body weight change, time to complete healing of the wounds, the evaporative water loss from the wound surface and the rate of new formation of epithelial cell layers on the epidermal and corneal wounds. Wounded animals treated with 0.9% NaCl were used as controls. After removal of the corneal epithelium the local application of EGF stimulated the regeneration process appreciably. No significant healing advantage from the treatment with EGF was observed, however, in epidermal wounds and partial-thickness scalds. The result does not warrant any clinical evaluation.

Growth patterns in sheep: wool growth during weight loss and subsequent compensatory growth

SummaryWool growth rates (WGR) of individual sheep were measured by a patch-sampling technique, during periods of developmental growth, body-weight loss (which ranged from 21 to 34% of original body weight, at rates between 60 and 150g/day) and subsequent compensatory growth under ad libitum feeding.There was a ‘lag phase’ of about 30 days before WGR appeared to be affected by changes in direction of the animals' growth paths.During body-weight loss WGR declined about 300% more than the percentage change in body weight, with the duration of nutritional stress exerting a greater influence than the rate of body-weight loss.During compensatory growth in body weight, the relationship between WGR and rate of body-weight change was initially negative. Sheep required between 11 and 14 weeks to reach the WGR of 21 g/day found during developmental growth. Compensatory growth of wool did not occur.Duration of the nutritional stress, rather than its severity (as indicated by rate of body-weight loss), was the more important determinant of the time taken for the sheep to regain normal levels of wool growth after the commencement of ad libitum feeding.

Epidermal growth factor in the healing of corneal wounds, epidermal wounds and partial-thickness scalds. A controlled animal study.

The effects of the topical application and the intraperitoneal administration of epidermal growth factor (EGF) on the healing of epidermal wounds, and of partial-thickness scalds in rats and of corneal wounds in rabbits were evaluated. The parameters measured were the daily percentage body weight change, time to complete healing of the wounds, the evaporative water loss from the wound surface and the rate of new formation of epithelial cell layers on the epidermal and corneal wounds. Wounded animals treated with 0.9% NaCl were used as controls. After removal of the corneal epithelium the local application of EGF stimulated the regeneration process appreciably. No significant healing advantage from the treatment with EGF was observed, however, in epidermal wounds and partial-thickness scalds. The result does not warrant any clinical evaluation.

Abnormal relationship between sodium intake and sympathetic nervous system activity in salt-sensitive patients with essential hypertension

To examine the mechanisms underlying the sensitivity to sodium intake in a subset of patients with essential hypertension, we studied the effects of different sodium intake (10, 100, 200 mEq/day) on blood pressure, the function of the renin-angiotensin-aldosterone system, and on blood levels of catecholamines in 20 patients with essential hypertension and 10 normal subjects. Mean blood pressure (MBP) was not different in hypertensive and normal subjects during low sodium diet. But, with high sodium intake, MBP increased by at least 10% in 12 patients (salt-sensitive), whereas in the remaining 8 patients (salt-resistant) and in normal subjects, MBP did not change significantly. This phenomenon cannot be attributed to differences in sodium retention because the percent change in body weight ad the urinary sodium excretion in the salt-sensitive patients was not different than it was in salt-resistant patients or in normal subjects. The observed difference in blood pressure response to high sodium intake in salt-sensitive patients is also not dependent on an impaired suppressibility of the renin-angiotensin-aldosterone system because there were no significant differences in the basal levels of PRA and aldosterone between the groups, and because the orthostatic increments in PRA were significantly lower in salt sensitive than they were in the salt-resistant patients and in normal subjects. Plasma norepinephrine (NE) levels were not significantly different between normal subjects or hypertensive patients while on low sodium intake. But during high sodium intake, they decreased significantly (P less than 0.05) in normal subjects (from 22 +/- 3.4 to 12 +/- 2.3 ng/dl) and in salt-resistant patients (from 17 +/- 4.5 to 13 +/- 2.4 ng/dl) but not in salt-sensitive patients (from 20 +/- 1.9 to 22 +/- 3.2 ng/dl). Furthermore, the majority of salt-sensitive patients displayed inappropriately high plasma NE in relation to their urine excretion of sodium during high sodium intake. Finally, the increments in plasma NE after 5 min of standing were significantly greater in salt-sensitive patients than they were in salt-resistant patients and normal subjects during both low or high sodium intake. These data indicate that a subset of patients with essential hypertension may have impaired suppressibility of plasma NE during high sodium intake, which suggests hyperactivity of the sympathetic nervous system in these patients. These aberrations may be responsible for the increase in MBP in the salt-sensitive patients during high sodium intake.

Effects of sex of subject and spouse involvement on weight loss in a behavioral treatment program: A retrospective investigation

A subject × treatment model was used to examine the effects on weight loss of sex of subject and spouse involvement in behavioral treatment. Eleven males and 9 females who had completed a 12-week session of behavioral obesity treatment with their spouses, and individually matched male and female subjects who had completed treatment without their spouses, were assessed at follow-up 9–14 months after treatment. Males demonstrated a significantly greater weight,loss than did females on absolute body weight, weight change, percent change in body weight, and the Reduction Index. Males also appeared to maintain weight loss better than females. Spouse involvement had no effect on weight loss during treatment or over follow-up. Differences in weight loss between sexes could not be attributed to differences in age, initial percent overweight, age of onset of obesity, socioeconomic status, number of previous behavioral treatment sessions, self-reported activity level, or self-reported inappropriate eating patterns. Possible explanations of male-female differences in response to treatment are examined, and methodological implications of findings for obesity treatment outcome studies are discussed.

Effect of relaxin and somatotropin in combination with ovarian steroids on mammary glands in rats.

Hypophysectomized-ovariectomized rats were injected sc daily for 19 days. Nine treatment groups (N = 10) included a sham control, bovine somatotropin (STH, 1 mg/day) alone or in various combinations with porcine relaxin (K, 90 GPU/day), estradiol benzoate (EB, 1 ag/day) and progesterone (P, 3 mg/day). Percent increase in body weights ranged from 3.0 percent for controls to 34.3 percent for the STH + R + P group, with the STH + R group (27.5 percent) significantly higher than STH alone (16.6 percent). In all cases, the addition of R to the treatment regimen significantly increased the percent change in body weight for that respective regimen. Indices for response of six abdominal-inguinal mammary glands included percent dry fat-free tissue, DNA and RNA weights, the latter two by chemical methods. Dry fat-free tissue weight as a percentage of wet weight was 4.6 percent in controls. All treatment groups were significantly higher than controls with ranges from 5.5 percent (STH) to 7.9 percent (STH + R + EB + P). DNA per 100 g body weight indicated’ that STH alone was mammogenic. Compared to control DNA (2.71 mg), STH alone (4.07 mg) and STH + R (4.35 mg) showed stimulatory responses of 1.5 and 1.6-fold, respectively. Highest observed DNA per 100 g body weight (5.58 mg) was in the combination of four hormones. Mammary RNA per 100 g body weight was increased significantly above controls (.70 mg) in all groups except STH + LB and STH + EB + R. Results indicated that STH + R had the ability to synergize with EB + P to grow the mammary gland.

Practical, Raw-Soybean Diets for Egg-Type Pullets

Egg-type pullets, when 11 wk. old, were fed one of these practical-type diets: 14% protein corn, sorghum grain and oat-alfalfa meal-soybean meal diet (SBM); 12% protein sorghum grain-raw, unextracted soybean meal diet with supplemental methionine (RSBM + M) or without (RSBM). One group was fed the SMB diet from 11 to 22 wk. Two groups were fed the SBM diet from 11 to 14 wk., then from 15 to 22 wk., one group was fed the RSBM + M diet and the other the RSBM diet. At 23 wk. of age, half the pullets on each growing diet were switched to an 18% protein layer diet containing soybean meal (SBM); the other half, to an 18% protein diet containing raw, unextracted soybeans (RSBM).Pullets fed the SBM diet had the highest percent change in body weight between 11 and 22 wk.; those fed RSBM diet, the lowest (106.4 to 88.4%). Supplemental methionine partially reduced the depressing effect of raw, unextracted soybean meal on growth. Both growing and laying diets significantly affected sexual maturity (age at 50% production) and hen-day rate of lay. Ages at sexual maturity were 26.1, 25.1, and 24.7 wk., respectively, for birds fed RSBM, RSBM + M, or SBM growing diets.Hen-day production percentages were 56.8, 60.3, and 64.0, respectively, for birds fed RSBM, RSBM + M, or SBM growing diets; the percentages for birds reared on RSBM + M diet and switched to SBM layer diet nearly equaled that of birds fed SBM diet during both growing and laying periods (68.3 to 70.3).