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Department of Human Genetics and Teratology, National Institute of Public Health WHO Collaborating Centre for the Community Control of Hereditary Diseases, Budapest
Summary
The objective of the study was to determine the human teratogenic
risk of vitamin A supplementation during pregnancy. Paired analysis
of cases with congenital abnormalities and matched healthy controls
was performed in the large population-based data set of the Hungarian
Case-Control Surveillance of Congenital Abnormalities,
19801994. Of 35727 pregnant women who had control infants
without defects, 3399 (9.5%) were treated with vitamin A. Of 20830
pregnant women who had case offspring with congenital abnormalities,
1642 (7.9%) were treated with vitamin A, a rate that is significantly
lower than that of the control group (p < 0.001). The case-control
pair analysis also showed a lower rate of vitamin A treatment during
pregnancy and in the first trimester of gestation in most congenital
abnormality groups.
Thus, use of low or moderate doses of vitamin A (< 10,000 IU)
during the first trimester of pregnancy (i.e., organogenesis) is not
teratogenic but presents some protective effect to the fetus.
Keywords
Vitamin A, Case-Control study, Teratogenic effect, Congenital abnormalities, Antiteratogenic effect
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber AG, Bern
Department of Biochemistry & Biophysics, 3252 Molecular Biology Building, Iowa State University, Ames, IA 50011, USA
Summary
In keeping with the in vivo observation that the conversion of retinoyl b-glucuronide (RBG) to retinoic acid (RA) is enhanced in vitamin A-deficient (A) rats, the relative rates of hydrolysis of RBG to RA by various organelles of liver, kidney and intestine were found to be higher in A rats than in vitamin A-sufficient (A+) rats (mean ratio 1.28; range 1.051.63). The lysosomal fraction of kidney and the microsomal fraction of liver showed the highest ratios for RBG hydrolysis; namely, 1.63 and 1.57, respectively (p < 0.005). The rates of hydrolysis of an ether glucuronide, p-nitrophenyl-b-D-glucosiduronate (pNPG), were also enhanced in A rats. The ratios of activities were again highest in kidney lysosomes and in liver microsomes; namely, 1.51 (p < 0.005) and 1.42 (p < 0.05), respectively. The non-ionic detergent, Triton X-100, increased RBG hydrolysis in organelles of A+ (1927%) more than in those of A rats (814%). The ratios of activities ± SEM with 0.02% Triton X-100 in organelles of kidney, liver and intestine were 1.25 ± 0.03, 1.22 ± 0.03 and 1.24 ± 0.03 in A+ rats and were 1.11 ± 0.02, 1.07 ± 0.02 and 1.13 ± 0.03, respectively, in A rats. Thus, Triton X-100 had a significantly greater effect (p < 0.005) on the membranes of A+ rats than on those of A rats. In conclusion, the increased appearance of RA in the plasma after RBG administration in vivo seems to be caused by enhanced activity of b-glucuronidases in tissue organelles, augmented in part by better access of the substrate to the membrane-bound enzymes.
Keywords
Retinol, Vitamin A deficiency, Retinoyl b-glucuronide, Retinoic acid, Rats, Lysosomes, Microsomes
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber, Bern
Department of Physiology, Veterinary Faculty,
University of Leipzig, 04103 Leipzig, Germany
1 present address: Institute of Nutritional Sciences,
University of Potsdam
Summary
The effect of age on plasma levels and tissue distribution (liver, kidney) of retinol and retinyl esters was studied in dogs from birth to the age of 18 months. In newborn dogs vitamin A in plasma was low and increased within four weeks to levels found in adult dogs. At four weeks retinyl esters (stearate > palmitate) dominated over retinol in plasma. Liver levels increased over 400 times from 10 mg/g at birth within six months. At all times retinyl esters represented the majority of vitamin A (> 70%). In kidneys, highest levels were observed not before 18 months after birth. Results indicate obvious quantitative and qualitative differences concerning vitamin A accumulation in plasma and tissue possibly associated with changes from fetal development to suckling stage and later to the uptake of feed.
Keywords
Vitamin A, Tissue Distribution, Dog, Development
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber, Bern
1 Hospital Düren gemeinnützige
GmbH, Düren, Germany
2 Arkansas Children's Hospital Research Institute, Dept.
of Pediatrics (Gastroenterology), Little Rock, Arkansas
3 Justus-Liebig-University Giessen, Institute of
Nutritional Science, Giessen, Germany
Summary
In thirteen preterm infants, 45 full-term infants, and their
mothers thiamin was analyzed in plasma from maternal veins, umbilical
arteries, umbilical veins, and placental tissue. The blood flow in
the umbilical veins was determined by pulsed Doppler ultrasonography.
Thiamin-dependent transketolase was measured in erythrocytes from
full-term infants and their mothers. Plasma thiamin
concentrations in umbilical veins from preterm infants (227.0 ±
85.0 nmol/L) and full-term infants (121.3 ± 103.3 nmol/L) were
seven times greater than maternal concentrations (p < 0.005).
Maternal and umbilical thiamin concentrations were lower in the
full-term group compared to the preterm group (p < 0.05).
Arteriovenous concentration gradients were not feasible. The blood
flow in the umbilical veins was higher in full-term compared to
preterm infants (p < 0.05). However, intrauterine thiamin supply
(plasma thiamin concentration times umbilical plasma flow) and
placental thiamin concentrations were not different between preterm
and full-term infants. Thiamin saturation of transketolase was
greater in fetal than in maternal erythrocytes (p < 0.005); severe
thiamin deficiency was not observed.
Our findings suggest that thiamin turnover is similar in early and
late pregnancy. Fetal tissue uptake of thiamin is not substantial.
Transketolase activities suggest that thiamin status is sufficient
even in late pregnancy.
Keywords
Thiamin, Intrauterine turnover, Erythrocytic transketolase, Placenta, Full-term infants, Preterm infants
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber, Bern
Institute of Nutrition and Food Science, University of Perugia, PO Box 333, 06100 Perugia, Italy
Summary
b-Carotene, retinol, niacin, riboflavin, thiamin intake and blood
nutritional status (b-carotene, retinol, and a-tocopherol) were
investigated in a group of 79 subjects (35 males and 44 females) of
30 years and over, living in three rural hamlets in the Gubbio area
(Central Italy) to see if there were any differences in nutrient
intake using different methods of dietary assessment and if there was
a relationship between vitamin intake and status.
Vitamin intakes were assessed by three different methods: dietary
history, two-day weighed record and two-day duplicate-portion
chemical analysis. Vitamin content of duplicate diets was assessed by
semiautomated HPLC methods. Plasma vitamin status was assessed by
semiautomated isocratic straight-phase HPLC methods.
The three methods of dietary assessment were compared using the
Student's paired t-test and Wilcoxon-Mann-Whitney test. Between the
two days weighed record and diet history, significant differences
were observed for b-carotene and thiamin. Between the two-day weighed
record and chemical analysis, significant differences were found for
b-carotene, riboflavin and thiamin. Between diet history and chemical
analysis, significant differences were obtained for b-carotene,
riboflavin and thiamin. The t-test analysis showed different results
according to sex and age. Plasma vitamin status using the current
cut-off criteria showed some deficiencies for b-carotene. As on other
occasions no correlation was observed between data from diet history,
weighed record and chemical analysis of duplicate portions and the
corresponding blood vitamin levels for the whole group of subjects.
Keywords
Vitamin intake, Vitamin status, Vitamin methodology
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber, Bern
1 Departamento de Nutrición,
Facultad de Farmacia, Universidad Complutense, 28040-Madrid
(España)
2 Servicio de Análisis Clínicos, Hospital
Universitario Príncipe de Asturias, Alcalá de Henares,
Madrid (España)
3 Laboratorio de Técnicas Instrumentales, Facultad
de Farmacia, Universidad Complutense, 28040-Madrid (España)
Summary
In a group of 130 women of fertile age (24.5 ± 2.7 years),
the consumption of meat and meat products was evaluated in order to
determine the effect of this food group on blood and biochemical
parameters that act as indicators of iron status, and on a range of
serum lipid parameters that indicate cardiovascular risk. Food intake
was monitored using a "Food Record" for seven days, including a
Sunday. Subjects were divided into two groups: those who took >
100 g/day of meat (25th percentile) (high consumption HC) (n =
102), and those with lesser intakes (low consumption LC) (n =
28). Dietary data were adjusted to take into account differences in
discrepancies in reporting between the two groups.
The greater consumption of meat observed in HC subjects, despite its
association with greater intakes of lipids (both in g/day and % of
energy) and cholesterol (in mg/day and mg/1000 Kcal), did not seem to
be related to any impairment of blood lipid profiles. Neither was it
seen to be related to increased bodyweight nor raised blood pressure.
It should not, therefore, bring about any increased risk of
cardiovascular disease. However, the greater intake of thiamine,
niacin, zinc and iron (total and haem) in HC subjects suggests that
these may have a better nutritive status (with respect to certain
nutrients) than do LC subjects. In relation to iron status, HC
subjects showed higher levels of haemoglobin, haematocrit and mean
corpuscular haemoglobin concentration (MCHC). These results show that
restrictive criteria, with respect to the consumption of meat and
meat products, could have negative repercussions on the nutritive
status and health of certain groups within the population. In the
female population, such criteria may be associated with impairment of
iron status, without affording any greater level of protection
against cardiovascular disease, or be of any help in the control of
bodyweight.
Keywords
Meat consumption, Iron status, Lipid parameters, Young women, Cardiovascular risk
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber, Bern
1 Lipides Membranaires et Fonctions
Cardiovasculaires, INRA, Faculté des Sciences Pharmaceutiques
et Biologiques, 4 Avenue de l'Observatoire, 75270 Paris cedex 06,
France
2 Unité de Nutrition Lipidique, INRA, 17 rue Sully
21034 Dijon, France
Summary
We studied the influence of membrane polyunsaturated fatty acids (PUFA) on prostanoid metabolism in the vascular endothelium, in pathophysiological conditions. Two models of cultured endothelial cells were used, from bovine aorta (BAEC) and human umbilical vein (HUVEC). In physiological conditions, the main prostanoids were prostacyclin and PGE2 in the BAEC and prostacyclin and PGF2a in the HUVEC. Reoxygenation (2.5 hours) but not hypoxia (2.5 hours) enhanced prostanoid synthesis in both models. Cell enrichment with arachidonic acid (AA, n-6 cells) increased both AA and C22:4 n-6 and decreased n-3 PUFAs in the phospholipids. Conversely enrichment with eicosapentaenoic and docosahexaenoic acids (EPA and DHA, n-3 cells) increased the n-3 PUFAs and decreased the n-6 PUFAs. The BAEC incorporated more PUFA in the phospholipids than the HUVEC. Moreover in the n-3 cells, EPA incorporation was higher than that of DHA. Increasing AA increased the production of both prostacyclin and PGF2a by the BAEC and only that of PGF2a by the HUVEC. Increasing n-3 PUFA decreased the release of PGE2 and TxA2 by the BAEC and only that of prostacyclin by the HUVEC. In the n-6 cells, hypoxia became a stimulus for prostanoid production and the stimulating effect of reoxygenation was reinforced in the HUVEC whereas it was abolished in the BAEC. N-3 PUFA blocked the reoxygenation-stimulated production. These results suggest a strong importance of dietary PUFA in the response of vascular endothelium to pathological conditions.
Keywords
Cell culture, Endothelium, Hypoxia-Reoxygenation, Polyunsaturated Fatty Acid, Prostanoid
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber, Bern
1 National Food Research Institute, 2-1-2,
Kannondai, Tsukuba, Ibaraki 305, Japan
2 Food Research Laboratories, Mitsui Norin Co., Ltd.,
223-1, Miyahara, Fujieda, Shizuoka 426-01, Japan
Summary
Cholesterol-free diets, which contain 0.003% tea catechins with perilla oil rich in a-linolenic acid, were given to male mice for periods of 6 and 15 months. Cholesterol levels decreased significantly in mice fed the catechin diet for 6 and 15 months compared to the animals fed the control diet. The phospholipid level of mice fed the catechin diet for 15 months was lower than that of animals fed the control diet. No marked difference in triglyceride levels between the catechin and control diet groups was observed. Hardly any enhancing effects of catechins on the percentages of n-3 polyunsaturated fatty acids in plasma lipids were found, although the eicosapentaenoic acid level at 15 months was reduced in the catechin diet group.
Keywords
Tea catechins, Plasma lipids, Perilla oil, Polyunsaturated fatty acids
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 4, © Verlag Hans Huber AG, Bern