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Biomedical subjects

A Kirksey

Publications and source records attributed to A Kirksey.

At least 55 records · Page 3Linked to original sources
PubMed1979

Vitamin B6 nutriture during pregnancy and lactation. I. Vitamin B6 intake, levels of the vitamin in biological fluids, and condition of the infant at birth.

Vitamin B6 nutriture was assessed during pregnancy and lactation to determine possible relationships among vitamin B6 intake, levels of the vitamin in biological fluids and the condition of the infant at birth. Vitamin B6 levels were measured in maternal serum and in urine at 5 and 7 months gestation and at delivery, in cord serum and in milk at 3 and 14 days postpartum. Intake of vitamin B6, less than the Recommended Dietary Allowances (1974) for pregnancy and lactation, 2.5 mg/day, resulted in lower levels of the vitamin in maternal serum at delivery and in cord serum than higher intakes. Mothers whose infants had unsatisfactory Apgar scores at 1 min, (less than 7) had significantly low intakes of vitamin B6 and lower levels of the vitamin in both serum and milk than mothers whose infants had satisfactory scores, (greater than or equal to 7). At 5 months gestation, levels of vitamin B6 in maternal serum were significantly correlated with levels of the vitamin in cord serum and in milk at 14 days postpartum. This stage of gestation precedes the period of rapid growth of the central nervous system of the fetus, and is, therefore, a critical time for the assessment of maternal vitamin B6 nutriture.

Adolescent↗
PubMed1979

Vitamin B6 nutriture during pregnancy and lactation. II. The effect of long-term use of oral contraceptives.

Vitamin B6 nutriture was assessed during pregnancy and lactation to determine whether previous use of oral contraceptive agents (OCA) resulted in reduced reserves of the vitamin. Vitamin B6 levels were measured in maternal serum and urine at 5 and 7 months gestation and at delivery, in cord serum and in milk at 3 and 14 days postpartum. Long-term use of OCA (greater than 30 months) resulted in low levels of vitamin B6 in maternal serum at 5 months gestation and at delivery and in milk compared with values for short-term (1 to 30 months) and nonusers of OCA. Levels of vitamin B6 were also lower in the cord serum of long-term users of OCA as compared to nonusers.

Adolescent↗
PubMed1979

Influence of dietary pyridoxine on selected immune capacities of rat dams and pups.

The influence of dietary pyridoxine on passive antibody transfer from dams to pups and on active humoral antibody formation by the pups was studied. Rats were fed diets containing 20.0, 0.6, 0.45, or 0.3 mg pyridoxine-HCl/kg during gestation and 20.0, 0.4, 0.3, or 0.2 mg/kg during lactation (diets A, B, C, and D). Diets B, C, and D contained 100, 75, and 50% of the NRC requirement for pyridoxine during gestation and lactation. After pups in groups B, C, and D developed signs of pyridoxine deficiency, all dams were fed diet A on days 9 to 21 of lactation. On day 9 vitamin B-6 levels were lower in spleens and thymuses of pups and in milk in groups B, C, and D. However, IgG in sera of dams and pups and in milk indicated that passive antibody transfer was similar for all groups. After weaning, pups in groups A, B, C, and D were fed diets containing 20.0, 0.4, 0.2, and 0 mg vitamin B-6/kg, respectively. On day 35 vitamin B-6 levels were lower in spleens and thymuses of pups fed inadequate pyridoxine (groups B, C, and D). These pups had fewer spleen cells and splenic antibody-forming cells (AFC) and lower levels of humoral antibody. The reduction in spleen cells and splenic AFC resulted in part from lower food intake but was intensified by pyridoxine deprivation.

Aging↗
PubMed1979

Reversal of protein-energy malnutrition in children during treatment of advanced neoplastic disease.

The effectiveness of enteral and parenteral feeding in supporting a satisfactory nutritional status and/or reversing protein-energy malnutrition was evaluated in 28 children, ages 1-19 (14 female) with advanced malignant disease (21 solid tumors, 7 leukemia-lymphoma). At the onset of treatment, 21 patients received intensive nutritional counseling (INC) and oral supplementation while seven received total parenteral nutrition (TPN). Sixteen of 21 patients who received INC had a decreased intake (x 48 +/- 24%) Recommended Dietary Allowances (RDA) for kilocalories and dramatic weight loss (x 16.4 +/- 12.4%). A total of 18 patients received TPN for a mean of 24 days (7-60); kcal averaged 90 +/- 26% RDA during weight gain. At onset of TPN, the mean serum albumin, transferrin and total lymphocyte counts were 3.06 +/- 0.38 g/dl, 175 +/- 62 mg/dl, and 1102 +/- 966/mm3 respectively, 15/18 children had subnormal anthropometric measurements and 17/18 patients were anergic to recall skin test antigens. TPN for less than 9-14 days neither repleted weight, skinfold reserves, nor serum albumin concentrations (greater than 3.2 g/dl) although an early increase (p less than .02) in transferrin concentration was observed. However, TPN for 28 days supported weight gain (3.27 kg, 16 +/- 6%), increased serum albumin (0.62 +/- 0.43 g/dl, p less than .001) and transferrin (62 +/- 42, p less than .002) to normal concentrations and reversed anergy in 7/11 patients retested. This study documents the severity of protein energy malnutrition which accompanies intense treatment of children with cancer and the nutritional and immunological benefits of a 28 day course of TPN.

Adolescent↗
PubMed1978

Nutritional status of adolescent girls in regard to zinc, copper, and iron.

Adolescent girls in the sixth through eight grades were surveyed for dietary intake and nutritional status in regard to zinc, copper, and iron in both the fall of 1975 and the spring of 1976. The adolescents (183 girls in the fall and 184 girls in the spring) consumed on the average 60 and 75% of the Recommended Dietary Allowances for iron and zinc, respectively. The mean concentration of zinc in hair samples was 216 +/- 64 microgram/g in the fall and 191 +/- 36 microgram/g in the spring. The mean concentration of copper in hair samples was 31 +/- 23 microgram/g. None of the girls had a concentration of zinc in their hair samples of less than 100 microgram/g. Hair concentrations of zinc anc copper were significantly correlated, but serum and hair concentrations of zinc were inversely correlated. However, in subsample of 102 girls, 3% has serum zinc levels below 70 microgram/100 ml and 4% had serum copper levels below 70 microgram/100 ml. Only 1% of the subjects had a hematocrit below 36%. No significant difference in any of these parameters was noted between girls who had experienced menarche and those who had not.

Adolescent↗
PubMed1978

Influence of different levels of dietary pyridoxine on milk composition in the rat.

The effects of five different levels of dietary pyridoxine on milk composition were studied in the rat. Sprague-Dawley strain rats received diets containing 1.2, 2.4, 4.8, 9.6 or 19.2 mg pyridoxine-HCl/kg diet throughout growth, gestation and lactation. Milk samples obtained on days 10, 11, and 12 of lactation were similar in concentrations of total fat, solids-not-fat, carbohydrate, casein and non-casein protein for rats fed the five levels of pyridoxine. The level of vitamin B-6 in milk was significantly higher for rats fed 9.6 or 19.2 mg pyridoxine.HCl/kg diet compared to values for rats fed the three lower levels of vitamin. A higher level of dietary pyridoxine (9.6 mg/kg diet) was required to increase the levels of the vitamin in mammary gland and milk than was needed for maternal liver (4.8 mg/kg) or muscle tissue (2.4 mg/kg). The findings indicated that as the level of pyridoxine was decreased in the diet from an apparently adequate level, the concentration of the vitamin in milk decreased before that in liver or muscle tissue. This suggested that the concentration of the vitamin in milk was an indicator of marginal deficiency of vitamin B-6.

Animals↗
PubMed1978

Effects of vitamin B-6 deficiency on the developing central nervous system of the rat. Gross measurements and cytoarchitectural alterations.

The effects of different levels of dietary pyridoxine (1.0, 1.2, 1.4, and 20.0 mg/kg diet) fed to dams from weaning through lactation on gross measurements and cytoarchitectural alterations of brains of progeny were investigated. Progeny of the 1.0 and 1.2 groups died between 15 and 21 days of age due to the severe vitamin deficit. Differences were observed in brain and body weights and brain: body weight ratios. Vitamin B-6 concentrations in brain ranged from 498 to 713 ng/g in the three lower groups and were markedly lower than for the 20.0 group (2,256 ng/g). Protein concentrations were not different. Changes in cytoarchitecture, as seen by light microscopy, included reduced area in the neocortex and, to a greater extent, in the cerebellum of the deficient groups. Molecular and granular layers, but not medullary layer, of the cerebellum were significantly reduced. Significantly greater granular layer/molecular layer area ratios (GMR) in the 1.2 and 1.4 groups indicated that the molecular layer was more affected in these groups while both layers were affected in the 1.0 group. Purkinje cells were dispersed from the usual monocellular layer in the 1.0 and 1.2 groups. The results indicated that central nervous system development in the progeny is altered parallel to the maternal vitamin B-6 intake levels.

Animals↗
PubMed1978

Effects of vitamin B-6 deficiency on the developing central nervous system of the rat. Myelination.

The effects of different levels of dietary pyridoxine (1.0, 1.2, 1.4, and 20.0 mg/kg diet) fed to dams during growth, gestation and lactation on myelination in progeny were investigated. Degree of myelination at 15 days, postnatally, was determined from closely matched micrographs of the four dietary treatment groups. Electron micrographs showed markedly less myelination in the 1.0 group as compared with the 1.4 and 20.0 groups with the 1.2 group appearing intermediate in the number of myelinated axons. Some myelinated axons of the 1.0 group exhibited an "unusual" appearance of whorls of lamina separated by cytoplasmic space occupied by widely separated lamina. The results indicate that brain development, particularly myelination, was affected by a deficiency of vitamin B-6 prior to and including the period of rapid myelination.

Animals↗
PubMed1976

Influence of vitamin B6 intake on the content of the vitamin in human milk.

The influence of the level of vitamin B6 intake on the content of the vitamin in milk was studied in 19 healthy subjects whose stages of lactation ranged from 3 weeks to 30 months. Total vitamin B6 intakes, including extra-dietary sources of the vitamin, ranged from 1.3 to 12.5 mg per day with six subjects consuming less than the recommended allowance of 2.5 mg per day (RDA, 1974). Subjects consuming less than 2.5 mg of vitamin B6 per day had significantly less vitamin B6/liter milk (129 mug) than groups consuming 2.5 to 5.0 or greater than 5.0 mg per day (239 and 314 mug, respectively). Among subjects consuming greater than 2.5 mg of vitamin per day the stage of lactation did not influence the levels of protein or vitamin B6 in milk. Vitamin B6 intakes two to five times the recommended allowance did not significantly elevate the level of the vitamin in milk compared to values for subjects whose intakes approximated the allowance. The vitamin B6/protein ratio in milk of subjects consuming less than 2.5 mg vitamin B6 per day was 13 mug/g and was significantly lower than that observed for the other two groups (23 and 28 mug/g). Daily and weekly variations of the vitamin B6 and protein content in milk of individuals were small. However, marked diurnal variations in the vitamin B6 content were found in milk of individuals taking daily supplements of the vitamin with peak levels occurring in the afternoon 3 to 5 hr after supplements were taken in the morning.

Adult↗
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↗
PubMed1976

Effects of different levels of dietary iron on pregnancy superimposed upon growth in the rat.

The effects of feeding four levels of dietary iron, 10, 50, 250 and 1.250 mg/kg were studied during pregnancy in growing and adult rats. Hematological measurements, plasma iron and total iron binding capacity, and iron content in liver, spleen and tibia were compared relative to pregnancy, diet and growth. Iron content in fetuses and fetal livers were compared relative to diet and growth of the dams. All parameters were lowest in rats fed the 10 mg Fe/kg diet. The highest level of iron fed, 1,250 mg/kg, resulted in increased iron content in liver, spleen and tibia of all treatment groups but did not alter hematological values or fetal iron content. Pregnant rats fed any of the four levels of iron had significantly lower Hb, Ht, total and storage iron concentration and ferritin and hemosiderin iron in liver than nonpregnant rats fed the same levels. The level of dietary iron needed by growing pregnant rats for maximal iron content in fetuses and fetal livers was between 50 and 250 mg Fe/kg which was fivefold that needed to obtain maximal hemoglobin concentration in dams. However, adult pregnant rats only needed between 10 to 50 mg Fe/kg for both maximal iron stores in fetal tissues and maximal hemoglobin concentration.

Animals↗
PubMed1976

Influence of different levels of dietary pyridoxine on certain parameters of developing and mature brains in rats.

The influence of different levels of dietary pyridoxine-HC1 (1.2, 2.4, 4.8, 9.6, 19.2, 38.4, 76.8 and 153.6 mg/kg diet) fed to dams on certain parameters of developing and mature brain was studied in rats. Brain weights and alanine aminotransferase (ALAT) activities (initial and following in vitro addition of pyridoxal phosphate, PLP) were significantly reduced in brains of 12-day-old pups of dams fed the lowest level of pyridoxine compared to other treatments; in vitro addition of PLP significantly stimulated the activities of glutamic acid decarboxylase (GAD) and ALAT. Vitamin B-6 concentrations in brain were higher for 2-day-old pups of dams fed 38.4 or 76.8 mg vitamin/kg diet and for 12-day-old pups of dams fed 2.4 to 153.6 mg compared to the 1.2 mg groups; at weaning, values were greater in groups fed 76.8 or 153.6 mg compared to the 1.2 mg group. As brain developed during the suckling period, the content of bitamin B-6 and protein increased in all groups, except the 1.2 mg group in which values remained the same. The vitamin and protein content in brain had not reached chemical maturity at weaning as evidenced by greater concentrations of each in brains of dams as compared with values for 21-day-old progeny. As brain developed, ALAT activity increased about 30 times from age 2 to 21 days when activities were similar to those observed in mature brains of dams. Activity of GAD in brain increased about four times from age 12 to 21 days.

Age Factors↗