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Biomedical subjects

M R Thomas

Publications and source records attributed to M R Thomas.

At least 145 records · Page 8Linked to original sources
PubMed1981

Vitamin A and vitamin E concentration of the milk from mothers of pre-term infants and milk of mothers of full term infants.

The vitamin E, vitamin A and beta carotene concentrations of milk, from eight mothers delivering premature infants and ten mothers delivering full term infants were determined and compared. Milk samples were collected three times per day on days 3, 9, 15, 21, 27 and 33 postpartum. Dietary records were kept on days 2-3, 14-15, and 32-33. There was no significant difference in vitamin E, vitamin A and beta carotene levels between the two groups. The mean retinol concentration was higher in the milk of mothers of premature infants on all days except day three. The highest mean carotene and retinol concentrations in the milk of mothers of full terms infants were on day three: but the peak occurred in the preterm group on day nine and did not drop as rapidly as the milk retinol of the full term group. The milk of mothers of fullterm infants, day 3 vitamin E concentration was significantly higher than days, 15, 21, 27 and 33 postpartum. There were no significant differences in the dietary intake of the full term and preterm groups. The amount of vitamin E in the milk was not affected by dietary vitamin E intake of the subjects regardless of gestational age of the infant. More research is needed to determine the exact quantity of vitamin A and E ingested by the premature infants if breastfed by their respective mothers.

Adult↗
PubMed1980

The effects of vitamin C, vitamin B6, vitamin B12, folic acid, riboflavin, and thiamin on the breast milk and maternal status of well-nourished women at 6 months postpartum.

The effects of vitamin supplements and/or diet on the vitamin levels in milk of women were determined at 6 months postpartum. Six subjects consumed a daily supplement (Natalins, Mead-Johnson) in addition to a well-balanced diet--supplemented group, and six subjects consumed only a well-balanced diet--nonsupplemented group. The subjects expressed milk for 3 days at 4-hr intervals, 0, 4, 8, and 12 hr after awakening or taking their vitamin supplement. A 4-day diet record, fasting blood sample, and 24-hr urine samples were collected on each subject at 6 months postpartum. Nutrient intake from diet alone did not differ significantly between the two groups except for riboflavin intake which was significantly higher in the supplemented group. The nutritional status of all women indicated excellent dietary intakes, which vitamin supplementation did not alter significantly. Milk concentration of vitamin B6, vitamin B12, folate, thiamin, riboflavin, and vitamin C, did not differ significntly between groups. Thiamin, vitamin B12, and vitamin B6 concentration in the milk did appear to plateau during the day. Vitamin supplementatin at 6 months postpartum did not affect the breast milk concentration or the nutritional status of well-nourished women.

Ascorbic Acid↗
PubMed1980

The effect of thiamin and riboflavin supplementation on the level of those vitamins in human breast milk and urine.

Thiamin and riboflavin concentrations in urine and breast milk were measured to see if vitamin supplementation during lactation is beneficial to healthy well-nourished women. seven supplemented subjects and five nonsupplemented subjects expressed milk four times per day for 3 days at 1 and 6 weeks postpartum. Dietary intakes were recorded for 1 day before milk collection and the 3 days of milk collection. A 24-hr urine sample was collected at 1 and 6 weeks postpartum. Mean thiamin concentration in the milk increased significantly in both groups between 1 and 6 weeks postpartum, although there were no significant differences between groups. Riboflavin values reflected in the milk were significantly lower in the nonsupplemented group of women both at 1 and 6 weeks postpartum, but values did not change significantly in either groups as the milk matured from 1 to 6 weeks postpartum. Urinary excretion of thiamin and riboflavin was proportionally higher in the supplemented group of women. Riboflavin and thiamin status of both groups of women depicted normal intakes and the milk concentration of thiamin and riboflavin either met or exceeded established norms in both groups of women.

Adolescent↗
PubMed1980

Effects of a glandless cottonseed protein diet on fasting plasma amino acid levels in college women.

Plasma amino acids were determined and correlated to the level of dietary amino acids consumed over a 42-day period. Six college women, ages 19 to 23, were fed meals in which 99% of the dietary protein was supplied by glandless cottonseed flour. The protein content was decreased weekly from 14.6 to 9.9, 8.7, 7.5, 6.9, and 6.3 g nitrogen per day, until that amount was found that would not maintain nitrogen equilibrium. Fasting blood samples were obtained after subjects had consumed a specific protein level for 1 week. Significant (P less than 0.05) decreases in fasting plasma free amino acid levels occurred from day 0 to 7 of the study for threonine, proline, isoleucine, leucine, tyrosine, and lysine. There were no significant differences in these plasma amino acids thereafter. Of the essential amino acids, leucine, valine, histidine, and lysine appeared to have similar graphical trends between the plasma and dietary amino acid concentrations over the entire 6-week period. However, only leucine had a significant (P less than 0.05) correlation. Results indicated that fasting plasma free amino acid concentrations of young women on a cottonseed protein diet appear to drop initially, but rarely fall beyond the realms of normal values during nitrogen equilibrium.

Adult↗
PubMed1979

The effects of vitamin C, vitamin B6, and vitamin B12 supplementation on the breast milk and maternal status of well-nourished women.

The effects of vitamin supplements and/or diet on the levels of vitamin C, vitamin B6, and vitamin B12 in milk and blood of lactating women were determined. At the end of gestation, subjects were divided into two lactation groups: supplemented (10 subjects) and nonsupplemented (seven subjects). Milk samples were collected from 5 to 7 days and 43 to 45 days postpartum. Fasting blood samples were drawn at 8 and 46 days postpartum for vitamin C, B6, and B12 status measurements. Dietary records of all foods consumed by the subject were kept for 4 days at 1 and 6 weeks postpartum. The vitamin B6 level in breast milk of the unsupplemented group of mothers was significantly lower (P less than 0.05) than the supplemented group of women at 5 to 7 days postpartum. Vitamin B12 concentration in milk of nonsupplemented mothers at 43 to 45 days postpartum was significantly lower (P less than 0.05) than the supplemented group of women at 43 to 45 days postpartum. None of the milk values or the maternal blood levels measured in the women was less than published norms for vitamin C, vitamin B6, and vitamin B12.

Ascorbic Acid↗
PubMed1979

Minimum nitrogen requirement from glandless cottonseed protein for nitrogen balance in college women.

Seven women, 18 to 23 years of age, were fed cooked cottonseed products for 42 days in order to determine the minimum nitrogen requirements for glandless cottonseen flour after baking. The women consumed from 81 to 213 mg N/kg body weight from cottonseed protein. Nitrogen intake from each experimental period was calculated from the average nitrogen content of the cottonseed products consumed each day of the experiment period. Nitrogen excretion was determined from the measurement of nitrogen in a total collection of urine and feces for each experimental period plus an obligatory loss of 5 mg/kg body weight. Fasting blood samples were taken prior to the study and at the end of each 7-day experimental period thereafter. The minimum requirement for cottonseed protein to maintain a positive nitrogen balance was 106 mg N/kg body weight. For the "reference woman," weighing 58 kg, at least 6.1 g of cottonseed flour nitrogen would be required to maintain nitrogen equilibrium. Plasma amino acid values of threonine, proline, valine, isoleucine, leucine, tyrosine, and lysine decreased significantly from day 0 to day 7 of the study. There were no significant differences in these plasma amino acids thereafter. Cottonseed flour incorporated into baked products maintained nitrogen balance in college women with no change in their nutritional status.

Adolescent↗
PubMed1977

Function of lateral reticular nucleus in central cardiovascular regulation in the cat.

The role of the lateral reticular nucleus (LRN) in central cardiovascular regulation was investigated in cats. In 15 cerebellectomized and nine intact chloralosed cats stimulation of 115 histologically verified sites in the LRN elicited increases in arterial pressure and heart rate; the latter was abolished by propranolol but not by bilateral cervical vagotomy. The pressor response was significantly greater in intact animals. Electrical activity was recorded from the right inferior cardiac nerve (ICN) during stimulation fo the LRN and of a vasomotor region in the posteromedial hypothalamus (PMH). Stimulation of sites in the LRN and in the PMH, on both sides, elicited a response in the right ICN that was consistently abolished during baroreceptor excitation. Medullary transection 3 mm rostral to the LRN did not abolish the ICN response to LRN stimulation. The conclusions are drawn that stimulation of the LRN elicits cardiovascular responses probably due to excitation of groups of neurons in this nucleus located in a descending sympathetic pathway originating in the PMH and that these responses can be inhibited by excitation of baroreceptors. In view of the known functional connections of the LRN with the somatomotor system it is suggested that this nucleus may play a major role in somatosympathetic reflexes.

Animals↗
PubMed1976

Development of a diagnostic checklist for low back pain patients.

The study of psychosomatic disorders implies that environmental variables, as well as attitudes and personality, can influence an individual's physical health. The present study developed a checklist composed of demographic and psychological variables to help to make diagnostic decisions related to chronic low-back pain. The need for the checklist stems from the situation that medical clinical evidence is often inconclusive to identify the etiology of patient complaints of low back pain. Cut-off scores on the checklist were able to discriminate with greater than 80% accuracy patients who received a specific medical diagnosis from patients who received a non-specific medical diagnosis. The findings provide additional support for procedures used to make difficult diagnoses of low back pain.

Adult↗
PubMed1976

Comparison of verbal reinforcement with information feedback in analogue psychotherapy.

Thirty Ss were assigned randomly to one of the two experimental analogue psychotherapy groups and a control group. In the experimental psychotherapy groups two different psychotherapy techniques were used for eight sessions. The two psychotherapy techniques employed were one-word verbal reinforcement (VR) and lengthy verbal information feedback (IF). Three therapists each demonstrated significant differences (P less than .001) in their verbal interactions with the Ss when they used the two different psychotherapy techniques. The results indicated that both treatment techniques were significantly effective (p less than .05) in improving self-ratings of self-concept. However, the two psychotherapy techniques were differentially effective in improving social skills as measured by behavioral ratings.

Adolescent↗
PubMed1976

Postnatal patterns of brain lipids in progeny of vitamin B-6 deficient rats before and after pyridoxine supplementation.

The influence of deficient and adequate maternal intakes of pyridoxine on lipid profiles in brains of progeny at 5, 10, 15, 25 and 50 days of age was studied. The effects of supplementing deficient dams at two different times with pyridoxine on the brain development of progeny were also examined. Three groups of weanling, female rats were fed diets deficient in pyridoxine (1.2 mg pyridoxine-HC1/kg diet) and another group received a control diet (30.0 mg pyridoxine-HC1/kg diet). One deficient group and the control group were fed their diets throughout growth, gestation and lactation. Two groups of dams were fed the deficient diet through growth, gestation and until 5 or 10 days postpartum when pyridoxine was supplemented by feeding the control diet. Body and brain weights were significantly lower in 15, 25 and 50 day-old progeny of deficient dams and deficient dams supplemented at 10 days postpartum. Cerebroside content at 15 days and ganglioside content at 15 and 25 days were significantly lower in brains of pups from unsupplemented deficient dams and deficient dams supplemented at 10 days postpartum. The postnatal development of cerebroside and ganglioside levels in brain was delayed or retarded in brain of pups from unsupplemented deficient dams. Supplementation of dams fed a low level of pyridoxine (1.2 mg/kg diet) with the vitamin beginning at 5 days postpartum reversed all observed effects of the low vitamin intake on brain lipids in progeny.

Age Factors↗
PubMed1976

Postnatal patterns of fatty acids in brain of progeny from vitamin B-6 deficient rats before and after pyridoxine supplementation.

The influence of deficient and adequate maternal intakes of pyridoxine on fatty acid profiles in brains of progeny at 5, 10, and 15 days of age was studied. The effects of two different times of initiating rehabilitation of deficient dams on the brain development of progeny at 5, 10, 15, 25, and 50 days of age were also examined. Three groups of weanling, female rats were fed diets deficient in pyridoxine (1.2 mg pyridoxine-HC1/kg diet) and a fourth group received a control diet (30.0 mg pyridoxine-HC1/kg diet) throughout growth, gestation and until 5 and 10 days postpartum. Supplementation with 30.0 mg pyridoxine-HC1/kg was begun in two deficient groups at 5 and 10 days postpartum. Fatty acids C18:2, C20:4, and C22:6 in cerebellum were significantly lower in brains of 15 day-old pups from unsupplemented deficient dams compared to values for pups of control dams. Significant reductions in the omega6 fatty acids (C18:2, C20:4, and C22:4) were evident in cerebellum of 15 day-old progeny of unsupplemented deficient dams. Fatty acids C20:1 and C24:0 were not detectable in cerebellum or cerebrum of the deficient group at 15 days but were evident in other groups. Supplementation of deficient dams with vitamin B-6 at 5 and 10 days postpartum prevented the reduction of omega6 fatty acids found in deficient progeny.

Age Factors↗
PubMed1976

Influence of pyridoxine supplementation on vitamin B-6 levels in milk of rats deficient in the vitamin.

Levels of vitamin B-6 in milk from pyridoxine deficient dams were used as an indicator of the ability of pyridoxine to protect offspring against the effects of the deficiency. Sprague Dawley rats were fed a basal diet containing 30.0 (control) or 1.2 (deficient) mg pyridoxine-HC1/kg diet from weaning throughout growth, gestation and until 5 days postpartum. At this time, deficient dams were supplemented by a single intraperitoneal injection of 600 mug pyridoxine-HC1, or by adding 30 or 60 mg pyridoxine-HC1/kg to the diet. The vitamin B-6 content in milk form the group supplemented by injection exceeded the control level of 38.8 mug/100 ml milk 30 minutes after the injection, and reached a peak level of 110.7 mug/100 ml at 4 hours with a subsequent decline to 27mug/100 ml at 20 hours. In rats supplemented orally with 30 or 60 mg pyridoxine-HC1/kg diet, the vitamin B-6 level in the milk reached the control value in 24 and 6 hours, respectively. At 120 hours, orally supplemented dams had significantly higher levels of vitamin B-6 in the milk than control animals. Vitamin supplementation of dams by a single injection of pyridoxine-HC1 was sufficient to overcome the pyridoxine deficiency syndrome in the pups, but was not adequate for optimum growth.

Animals↗