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Biomedical subjects

J Leichter

Publications and source records attributed to J Leichter.

At least 37 records · Page 2Linked to original sources
PubMed1984

Does dehydration contribute to retarded fetal growth in rats exposed to alcohol during gestation?

An earlier study showed that pregnant rats given ethanol in drinking water exhibited a significant degree of dehydration. The objective of the present study was to determine whether dehydration alone contributes to fetal growth retardation in alcohol treated rats. Female Sprague-Dawley rats were divided into 4 dietary groups. Group 1 (alcohol) received 20% ethanol in drinking water for four weeks prior to mating and 30% alcohol in drinking water throughout pregnancy and a stock diet ad libitum. Group 2 (pair-fed) was given an amount of food equal to that consumed by the alcohol group with the alcohol isocalorically substituted by corn starch. Water was available ad libitum. Group 3 (pair-water) was given an amount of food and water equal to that consumed by the alcohol animals. Group 4 (ad libitum) was given food and water ad libitum. On day 21 of gestation body weights of the alcohol exposed fetuses were significantly lower than those of the other three treatment groups. The difference in fetal body weights between the pair-fed and pair-water groups was not significant. Placentas were significantly heavier in the alcohol group than in the pair-fed and pair-water groups. Maternal plasma osmolality was significantly higher in the alcohol treated rats when compared to the pair-fed and ad libitum controls but not the pair-water group. No significant differences were seen in fetal plasma osmolality among the four treatment groups. It is concluded that dehydration does not contribute significantly to retarded fetal growth in rats given alcohol in drinking water as the sole source of fluid prior to and during gestation.

Animals↗
PubMed1984

Relation between dietary-induced increase of intestinal lactase activity and lactose digestion and absorption in adult rats.

To study the relation between dietary-induced increase of intestinal lactase activity and lactose absorption, 11-wk-old rats were fed either a high-starch (70 cal%), low-fat (7 cal%) diet or a low-starch (5 cal%), high-fat (73 cal%) diet for 7 days. Food intake and body weight changes were similar in the two dietary groups. In the first experiment, lactose absorption was studied in vivo after oral administration of 600 mg lactose (10% solution in water with added [3H]PEG) to rats fasted for 16 h. Groups of rats were killed at time 0 and at 1-h intervals for the next 3 h. Lactase activity and lactose absorption were significantly higher (P less than 0.01) in the high-starch group than in the low-starch group. In the subsequent experiment, 9-wk-old rats were fed the two isocaloric diets for 3 days. By use of the everted sac technique, we have demonstrated a significantly higher absorption of monosaccharides from lactose in the high-starch diet group; also, glucose transport was higher in the high-starch diet-fed animals. When Tris, an inhibitor of lactase, was added into the mucosal fluid, absorption of lactose was abolished and no effect was seen on glucose absorption (in vivo and in vitro). In both experiments, significant linear regression was established between lactase activity and lactose absorption. Our results thus show that the increase in lactase activity, induced by feeding a high-starch diet to adult rats, is accompanied by an increased capacity to hydrolyze lactose and absorb the constituent monosaccharides.

Absorption↗
PubMed1984

Plasma amino acids and glucose levels in the rat fetus and dam after chronic maternal alcohol consumption.

To evaluate the effect of chronic maternal alcohol consumption on plasma amino acid and glucose levels in both the fetus and the mother, female Sprague-Dawley rats were divided into 3 dietary treatment groups. Group 1 (alcohol) was fed ad libitum a stock diet plus 20% alcohol in drinking water for at least 4 weeks before mating and 30% alcohol during gestation. Group 2 was pair-fed the stock diet plus corn starch calorically equivalent to the amount of alcohol consumed by group 1 animals. Group 3 (control) received the stock diet and water ad libitum. On day 21 of gestation the fetuses of alcohol-treated dams weighed significantly less than those of the control and pair-fed groups. Fetal plasma glucose levels were significantly lower in the alcohol group when compared to those of the pair-fed and control groups, while the maternal glucose levels were similar in all three treatment groups. Plasma amino acid concentrations showed no corresponding trends in mother and fetus. Only proline was significantly reduced and alpha-amino-n-butyric acid elevated in the alcohol-treated dams when compared to the pair-fed and control rats. In the fetal plasma, only aspartic acid was significantly lower in the alcohol group when compared to the other two groups. A moderate degree of dehydration occurred in the alcohol-treated dams, but plasma albumin was within normal levels. It is concluded that the marked decrease in the concentration of plasma glucose in alcohol-exposed fetuses may be partially responsible for their retarded growth.

Alcoholism↗
PubMed1984

Intestinal folate conjugase activity and folate absorption in the ethanol-fed pregnant rat.

The effect of chronic alcohol consumption on intestinal folate conjugase activity and on the absorption of both mono- and polyglutamyl folates was evaluated in pregnant rats. Female rats were given either 20% ethanol in drinking water and rat chow ad libitum (alcohol group) or were fed rat chow and water ad libitum (controls). After four weeks on this regimen all animals were bred and the alcohol group was changed to 30% ethanol in water. Conjugase activity, in vivo folate absorption, and fetal and placental weights were measured on day 20 of gestation. The controls consumed more food than the alcohol group, which was reflected in significantly higher body weights of the control group. Fetal weights of the alcohol group were significantly lower than those of the controls, but litter size and placental weights were not significantly different. No significant differences were found in intestinal conjugase activity between the two groups of animals, but the intestinal absorption of both folate mono- and pentaglutamate were significantly higher in the alcohol than in the control group. The absorption of folate pentaglutamate was higher than that of folate monoglutamate in both groups of animals but the differences were not significant. These findings indicate that ethanol ingestion during pregnancy does not seem to interfere with either folate polyglutamate hydrolysis or folate absorption.

Animals↗
PubMed1983

Skeletal development in fetuses of rats consuming alcohol during gestation.

Sprague-Dawley female rats were fed either 20% ethanol in drinking water and rat chow ad libitum (alcohol group) or were pair-fed to the alcohol group, with starch substituted isocalorically for ethanol (pair-fed group) or were fed rat chow and tap water ad libitum. After 4 weeks they were bred and the alcohol group was changed to 30% ethanol in water. On day 20 of gestation the fetuses were removed and stained with Alcian Blue and Alizarin Red S. The skeletons were examined for the appearance of ossification centers and the ossification centers in the fore- and hindlimbs were measured. Fetuses from the alcohol group weighed significantly less than those of the two control groups. Ossification centers expected to appear in the skull on day 20 were absent in most of the alcohol group fetuses, but present in the control fetuses. There were fewer ossification centers in the sternum and in the limbs, and the ossification of vertebral centra has progressed less (both anteriorly and posteriorly) in the alcohol fetuses than in the controls. Dimensions of the ossification centers in the limbs were less in the alcohol fetuses than in the controls. No gross malformations were seen in any of the fetuses. It is concluded that by day 20 of gestation skeletal development is retarded by approximately one day in the fetuses of rats given alcohol prior to and throughout gestation.

Animals↗
PubMed1983

Effect of oral contraceptives on intestinal folate conjugase activity and folate absorption in rats.

To study whether oral contraceptive agents (OCA) may interfere with intestinal absorption of folate polyglutamates by inhibiting the activity of intestinal folate conjugase, female rats weighing on the average 230 gm received either a stock diet and OCA daily for a 6-week period or the stock diet without OCA. The animals receiving the OCA gained 50% less of their original body weight than the controls. There were no significant differences in the in vivo absorption of either folate monoglutamate or folate pentaglutamate between the controls and the OCA-administered animals. The absorption of folate pentaglutamate was lower than that of folate monoglutamate in both groups of rats, but the difference was not statistically significant (p greater than 0.05). As in the case of the two forms of folate absorption, no significant difference was found in intestinal folate conjugase activity between the two groups of animals. These findings indicate that intestinal folate conjugase activity and the absorption of both folate monoglutamate and pentaglutamate are not altered by oral contraceptive administration to female rats.

Animals↗
PubMed1982

Method of ethanol administration as a confounding factor in studies of fetal alcohol syndrome.

Female Sprague-Dawley rats were fed a complete liquid diet containing either 5.5% ethanol (mean daily intake of about 9g of ethanol per kg body weight) or an isocaloric amount of dextrose (control group), with additional water available ad libitum. The diets were fed for four weeks prior to and throughout pregnancy. On day 20 of gestation cardiac output and blood flow to the the placenta, heart, kidneys and uterus were measured and plasma osmolality and muscle dry weight were determined. No significant differences were seen between alcohol and control groups with respect to litter size, fetal weight, maternal cardiac output, blood flow to the placenta or other organs, plasma osmolality, or muscle dry weight. This contrasts with previous experiments in which a similar quantity of alcohol (as % calories) was offered in drinking water (equivalent to a mean daily ethanol intake of 10g/kg body weight). Under those conditions fetal weight was reduced, blood flow to the placenta was reduced, and plasma osmolality and muscle dry weight were increased, indicating a moderate degree of dehydration. It is concluded that the effect of ethanol ingestion is influenced by the mode of administration of the ethanol. Dehydration may be a confounding factor in studies of animal models of fetal alcohol syndrome, although it is not possible to rule out a differential metabolic response to alcohol, depending on the mode of administration.

Animals↗
PubMed1980

Effect of litter size on the physical growth and maturation of the offspring of rats given alcohol during gestation.

A study was conducted to determine if retarded postnatal growth and maturation of the offspring of rats receiving alcohol prior to and during gestation could be corrected by adjusting litter size at birth to 3 pups. Female Sprague-Dawley rats (200 to 220 g) were divided into 3 dietary treatment groups. Group 1 (alcohol) was fed ad libitum a stock diet (Purina Rat Chow) plus 20% alcohol in drinking water for at least 4 weeks before mating and 30% alcohol throughout gestation. Group 2 was pair-fed the stock diet and corn starch calorically equivalent to the amount of alcohol consumed. Group 3 (control) received the stock diet and water ad libitum. In each group litters were reduced to 3 or 8 pups on the first day of birth. After birth all animals had free access to water and stock diet until day 51 post conception. In agreement with previously reported studies, the offspring of alcohol-fed rats were lighter in body weight and smaller in body and tail length at all ages than were the controls. However, animals maintained in litters of 3 were not significantly different in weight and length from those raised in litters of 8, either for alcohol group or the controls. The pair-fed litters were not significantly different from the ad libitum controls. Skeletal measurements and calf muscle widths of alcohol fed rats at day 51 post conception were significantly less than those of ad libitum controls of the same litter size, with the pair-fed animals lying somewhere in between. However, in no case did alcohol or control animals raised in litters of 3 differ from the same group maintained in litters of eight. Total bone maturity scores of alcohol-fed offspring were significantly retarded, relative to pair-fed and ad libitum controls, but within any group, litters of 3 did not differ from litters of eight. The results of this study indicate that retarded postnatal growth and maturation of the offspring of rats receiving alcohol prior to and during gestation represents a direct effect of alcohol and is not a consequence of underfeeding.

Animal Nutritional Physiological Phenomena↗
PubMed1979

Folate conjugase activity in fresh vegetables and its effect on the determination of free folate content.

The levels of naturally-occurring folate conjugates in fresh asparagus, broccoli, Brussels sprouts, cabbage, cauliflower lettuce, and spinach were determined together with the effect on the hydrolysis of pteroylpolyglutamates during the extraction phase of the Lactobacillus casei assay. The levels of conjugate activity vary widely among the vegetables tested, from a low of 0.30 +/- 0.21 in lettuce to a high of 106.2 +/- 6.6 mumoles/hr per 100 mg of fresh weight in spinach. The free folate values (L. casei activity before chicken pancreas conjugase treatment) in the fresh vegetables boiled 1 hr after homogenization were significantly higher than those in vegetables boiled before homogenization, while there were no significant differences in total folate (L. casei activity after treatment with conjugase from chicken pancreas). The increase in free folate values must have been due to the action of endogenous conjugases on the pteroylpolyglutamates from the time the vegetables were homogenized until the conjugase was inactivated by heat. It is concluded that reliable free folate values in fresh vegetables can be obtained only if the naturally present conjugases are inactivated before homogenization of sample in order to prevent the hydrolysis of the pteroylpolyglutamates in the vegetables.

Brassica↗
PubMed1979

Effect of maternal ethanol administration on physical growth of the offspring in rats.

To study the effects of maternal alcohol consumption on the postnatal growth and physical development of the offspring, female Sprague-Dawley rats (200-220 g) were assigned to one of 3 groups. Group I (alcohol) received alcohol in drinking water (up to 20% v/v) for at least 4 weeks prior to mating, and 30% (v/v) throughout gestation. Purina Lab Chow was ad libitum. Group II (pair-fed) received the same amount of chow as was consumed by alcohol-fed animals, and an amount of corn starch calorically equivalent to the amount of alcohol consumed. Group III (ad libitum) were given chow and water ad libitum. Postnatally all animals were given chow and water ad libitum until day 51 post conception (PC). During pregnancy alcohol provided about 28% of the calories in group I, and the total calorie intakes of the alcohol and pair-fed groups were approximately 60% of that of the ad libitum controls. Weights at birth of offspring of pair-fed and ad libitum control mothers are not significantly different, but the offspring of animals given alcohol show a weight deficit of 28%, compared to the ad libitum controls. During the ensuing four weeks weight shows no indication of catching up to the controls. Total length shows the same pattern as body weight. Skeletal and muscle measurements are significantly less (p less than 0.01) in young of alcohol treated mothers than in those of the ad libitum control mothers. Skeletal maturity in the alcohol group lags behind (p less than 0.01) that of the pair-fed and ad libitum control groups and catch-up is not evident to day 51 PC. It is concluded that young born to animals given alcohol prior to and throughout gestation are physically and developmentally retarded and fail to catch up to the controls during the first four weeks after birth, although not exposed to alcohol postnatally.

Animals↗
PubMed1978

Nutritional status of a select group of free-living elderly people in Vancouver.

A study was conducted to determine the nutritional status of the free-living elderly population in Vancouver. The response rate of the sample was low. Dietary information from 104 single men and women and 23 couples was collected by the 24-hour recall method. Biochemical tests in 56 single individuals and 13 couples included measurement of hemoglobin concentration and hematocrit, plasma analysis for concentrations of total protein, iron, carotene, vitamin A, ascorbic acid, vitamin E and cholesterol and for transferrin saturation, and urine analysis for concentrations of creatinine, thiamin, riboflavin and N(1)-methylnicotinamide.Mean energy intakes were considerably below the Dietary Standard for Canada. However, mean intakes of individual nutrients were similar to or in excess of the Dietary Standard for Canada for single men and women and for married men. Married women had low average intakes of calcium, iron, thiamin and riboflavin but adequate intakes of other nutrients. Mean values for biochemical variables were within the accepted range as defined by the Interdepartmental Committee of Nutrition for National Defense in the United States. According to the Nutrition Canada definitions of "high risk" there were no individuals in high-risk categories for any biochemical variable except plasma cholesterol concentration and transferrin saturation. The dietary and biochemical data indicated that the nutritional status in this select group of elderly persons was good except for intake of total energy and, in married women, of calcium, iron, thiamin and riboflavin.

Aged↗
PubMed1978

HbAlc--an indicator of diabetic control.

Hemoglobin Alc levels were determined on 16 nondiabetic and 115 diabetic subjects. Twelve of the diabetic patients were newly diagnosed and 12 were in the remission phase. The mean percentage of HbAlc in the nondiabetic subjects was 4.33 +/- 0.39 (SE), in those with long-standing diabetes 8.34 +/- 0.23 SE, in newly diagnosed diabetic patients 8.99 +/- 0.50 SE, and in those undergoing partial remission 5.16 +/- 0.18 SE. The mean HbAlc levels of these four groups differed significantly (0.001 less than P less than 0.025). Among the diabetic subjects there was a good correlation between HbAlc level and such measures as fasting blood sugar, urinary sugar, and degree of diabetic control, whereas the correlations between HbAlc and age, sex, or duration of the disease were not significant. The obtained data show that HbAlc measurement can serve as an objective measure of glucose control in diabetic subjects.

Adolescent↗
PubMed1977

Dietary folate intake and concentration of folate in serum and erythrocytes in women using oral contraceptives.

Conflicting reports regarding the possible effect of oral contraceptives agents (OCA's) on folate status prompted us to evaluate the relationship between dietary folate intake and the concentration of folate in serum and erythrocytes among users and nonsuers of OCA's during two consecutive menstrual cycles. Twenty-two women (ages 19 to 28) had been on combination type OCA's for 4 months or more and a control group of 18 women (ages 18 to 29) had not used OCA's for at least 6 months prior to this study. The serum folate levels were lower in the OCA users than in the controls and the difference was statistically significant on day 5 of the menstrual cycle (P less t-an 0.05) but not on day 20. However, the differences in the erythrocyte folate levels and dietary folate intakes were not statistically significant between the two groups of subjects. There was a consistently higher degree of correlation between serum folate and folate intake among the control women than among the OCA users. Hematological parameters such as hemoglobin, hematocrit, mean corpuscular volume, mean corpusclar hemoglobin, mean corpuscular hemoglobin concentration and red cell count were similar in the two groups. It is concluded that the use of OCA's produces significantly lower serum folate levels during the first week of the menstrual cycle in spite of adequate folate intake.

Adult↗
PubMed1975

Effect of dietary lactose on the absorption of protein, fat and calcium in the postweaning rat.

To assess the effect of dietary lactose on the intestinal absorption of protein, fat and calcium in lactose intolerance due to low levels of intestinal lactase, balance studies were carried out on postweaning rats (initial weight 164 g) for a period of 10 days. The experimental diets contained either 10% or 30% lactose, while in the control diets the lactose was replaced with equivalent amounts of sucrose. The excretions of fecal and urinary nitrogen, calcium and fat are expressed as precent of intake over the 10-day period. The fecal excretion of nitrogen and fat was significantly higher in the lactose groups (P less than 0.05). The fecal calcium excretion, however, was lower in the lactose groups, the difference being significantly only in the case of the 30% lactose diet (P less than 0.001). There was no difference in urinary nitrogen excretion between the lactose and sucrose groups, but urinary calcium excretion was significantly higher in the rats fed the 30% lactose diet (P less than 0.01). These findings suggest that dietary lactose may reduce the absorption of protein and fat, but not of calcium, in individuals with low levels of intestinal lactase activity.

Animal Nutritional Physiological Phenomena↗
PubMed1975

Effect of oral administration of large quantities of ascorbic acid on blood levels and urinary excretion of ascorbic acid in healthy men.

The influence of the daily ingestion of 1, 2, 3, and 5 grams of ascorbic acid on whole blood and plasma ascorbic acid levels and on the urinary excretion of ascorbic acid has been investigated. The ingestion of one gram of ascorbic acid per day for one week significantly increases plasma and whole blood levels over presupplementation levels, but larger amounts of ascorbic acid do not further increase plasma and whole blood ascorbic acid levels. Urinary excretion increases with intake, up to intakes of 3 grams per day but does not increase further when 5 grams of ascorbic acid is ingested per day. Upon discontinuing ascorbic acid supplementation the plasma and whole blood levels decline rapidly and the urinary excretion of ascorbic acid falls to presupplementation values within a few days. The results suggest that there is need for a detailed study of the routes of excretion of ascorbic acid at high levels of intake and that the safety of ingesting large quantities of ascorbic acid may be questioned.

Adult↗