Biomedical subjects

M Gebre-Medhin

Publications and source records attributed to M Gebre-Medhin.

At least 73 records · Page 4Linked to original sources

PubMed1990

Amino acid transport across the placenta measured by positron emission tomography and analyzed by compartment modelling.

The materno-fetal transfer of methionine in the Rhesus monkey was investigated using positron emission tomography, a non-invasive in vivo tracer technique based on short-lived radionuclides. A bolus dose of [11CH3]-l-methionine was administered intravenously and the radioactivity concentrations in the placenta, the fetus and the maternal arterial blood were measured as functions of time and fitted to an equation derived from a four compartment model of the feto-placental complex. Rate constants were calculated describing maternal placental blood flow, the transfer of [11CH3]-l-methionine to the placental tissue and the fetus. The transfer rate of methionine to the fetus was estimated as 0.8-1.5 nmol/min/g placenta and was similar to the transfer to the placental tissue. An approximate blood flow through the intervillous space of 128 ml/min was found. The correlation between placental transfer to the fetus and the maternal blood flow in the intervillous space was low.

Animals↗

PubMed1989

A study of antenatal care at village level in rural Tanzania.

Antenatal care is an acknowledged measure for the reduction of maternal and perinatal mortality. In the rural village of Ilula, Tanzania, the possible impact of antenatal care on mortality was studied longitudinally on the basis of the 707 women delivered in the study period. Ninety-five percent of the antenatal records were available. Anemia, malaria and anticipated obstetric problems were the most frequent reasons for interventions. Among the women from the area who were delivered in hospital, 90% had been referred there. No relationship was found between the number of antenatal visits and the pregnancy outcome, but perinatal mortality was correlated to a low birth weight. Even with a mean attendance rate of six visits and full coverage by antenatal care maternal and perinatal mortality remains high.

Female↗

PubMed1989

Maternal weight, weight gain and birthweight at term in the rural Tanzanian village of Ilula.

In an area-based study in a rural Tanzanian village, the relations of maternal weight and weight gain during pregnancy to birthweight were analysed for 331 term deliveries. The distribution of body-mass index, used as an indicator of maternal nutritional status, was similar to the pattern seen in Sweden, although mean maternal height (156 cm) was 9 cm below that of Swedish women. Mean initial weight measured at week 14 was 53 kg and total pregnancy weight gain was 6 kg. Women weighing greater than or equal to 60 kg in early pregnancy gained less weight (0.16 kg/week) than those weighing less than 50 kg (0.22 kg/week). Birthweight was correlated both with maternal weight in early pregnancy and with weight gain during pregnancy, but only 10% of the variation in birthweight was explained by these maternal factors. Mean maternal weight 24 h postpartum was equal to the weight at 14 weeks of pregnancy, implying, on the average, no net weight gain. Women with a positive net weight gain had heavier babies than women with a negative net weight gain. Maternal anthropometric characteristics are important underlying determinants of intrauterine growth and birthweight, but they explain only a minor part of the variation and are of little value for screening purposes in individual women.

Adult↗

PubMed1989

Placental hormones and maternal glucose metabolism. A study of fetal growth in normal pregnancy.

The interrelations between three placental hormones (oestradiol, progesterone and hPL), maternal glucose metabolism, maternal anthropometry and fetal growth were studied in a sample of 52 carefully selected pregnant women. A relation was found between infant birthweight and both fasting blood glucose and t1/2 of glucose of an intravenous glucose tolerance test at week 37 of pregnancy. The serum concentrations of the placental hormones were not significantly related to the glucose variables. The correlation between birthweight and the maternal levels of hPL in late pregnancy (r = 0.60) persisted when fasting blood glucose and t1/2 of glucose were taken into account. Maternal fat mass was found to explain more of the variation in basal insulin levels around week 37 than did the placental hormones.

Adipose Tissue↗

PubMed1989

Selected trace elements and proteins in serum of apparently healthy newborn infants of mothers who smoked during pregnancy.

The serum concentrations of selected trace elements and proteins in cord blood from 17 newborn infants whose mothers were habitual smokers were compared with values from 22 infants of non-smoking mothers. All the mothers were healthy with normal pregnancies and deliveries. Cigarette smoke exposure was verified by determinations of nicotine, cotinine and thiocyanate concentrations in cord blood. Infants of smoking mothers had a slightly lower mean birth weight (3490 +/- 430 g) than control infants (3780 +/- 460 g). Infants of smokers had lower serum iron (p = 0.05) and prealbumin (p less than 0.05), but higher serum copper (p less than 0.05) and ceruloplasmin (p less than 0.01) levels than the controls. Infants of smoking mothers tended to have higher levels of the acute-phase reactants alpha-2-macroglobulin and orosomucoid, but lower levels of albumin, transferrin and retinol-binding-protein, although differences were not statistically significant.

Adult↗

PubMed1989

Increased plasma and erythrocyte selenium concentrations but decreased erythrocyte glutathione peroxidase activity after selenium supplementation in children with Down syndrome.

An investigation was made of the activity of glutathione peroxidase (GSH-Px) in erythrocytes and the levels of selenium in plasma and erythrocytes before, during and after selenium supplementation in children with Down syndrome (DS). This subject is of interest since it has been suggested that selenium supplementation could enhance the GSH-Px activity in erythrocytes, probably leading to improved protection against oxygen radicals, which might cause damage by lipid peroxidation, especially in the brain. Forty-eight children with DS were treated with selenium-rich yeast tablets (10 micrograms/kg body weight/day) for 6 months. The supplementation was well tolerated and no side effects were observed. Selenium supplementation resulted in increased concentrations of selenium both in plasma and erythrocytes, but decreased GSH-Px-activity in erythrocytes. Plasma and erythrocyte selenium levels but almost regained the initial values 12 months after termination of the supplementation. Erythrocyte GSH-Px activity, on the other hand, remained reduced and did not return to the presupplementation levels. Until we gain more knowledge about the biological functions of selenium in man and the role of oxygen metabolism in the development of presenile dementia in DS, universal selenium supplementation in DS patients cannot be recommended.

Adolescent↗

PubMed1989

A prospective area-based study of the outcome of pregnancy in rural Tanzania.

A prospective area-based study on the outcome of pregnancy was carried out in the rural village of Ilula in Tanzania. A coverage of 99% (n = 719) regarding the ultimate outcome for mother and child was achieved, including deliveries that took place in hospital (9%), at the dispensary (67%) and at home (23%). There were four maternal deaths (6/1,000). The mean birth weight for singletons was 3,070 g and the low birth weight (less than 2,500 g) rate 13%. From a gestational age of 37 weeks onwards there was a definite slowing of fetal growth. Perinatal mortality rate was 82 per 1,000 born, half of the deaths occurring in low birth weight babies. Twinning occurred in 3.5% and the mean length of gestation at delivery for these pregnancies was 35.5 weeks. Twins constituted 6.8% of newborns but accounted for 23.0% of perinatal losses, making twin pregnancy a major contributor to perinatal mortality. Post-term pregnancies carried no significant increase in mortality. It is concluded that reliable area-based data on the outcome of pregnancy in Tanzania can be obtained at village level, with good coverage of the study population, by properly instructed and motivated local staff with moderate supervisory support.

Delivery, Obstetric↗

PubMed1988

Serum albumin, retinol-binding protein, thyroxin-binding prealbumin and acute phase reactants as indicators of undernutrition in children with undue susceptibility to acute infections.

This study was conducted in order to test the usefulness of measuring the concentrations of selected serum proteins and acute phase reactants in assessing the nutritional status of children with undue susceptibility to acute infections. The concentrations of serum proteins were determined by an immunodiffusion technique in 28 children with undue susceptibility to infections and were compared with those in healthy children. The patients were grouped according to the clinical pattern, i.e. into children with mainly upper respiratory tract infections, with frequent middle ear infections and with lower respiratory tract infections. The total group and all three subgroups of patients had not only significantly lower (p less than 0.001 or p less than 0.01) mean serum levels of albumin and retinol-binding protein, but also of the acute phase reactants alpha 2-macroglobulin and ceruloplasmin (p less than 0.01) than the controls. No differences were observed between the patients and the controls in respect of the acute phase reactant orosomucoid. This study indicates that the concentrations of albumin and RBP along with selected acute phase reactants are rapidly influenced by altered nutritional status in children with undue susceptibility to acute infections.

Acute Disease↗

PubMed1988

Childhood mortality in relation to nutritional status and water supply--a prospective study from rural Malawi.

In connection with the introduction of an improved method of water supply in rural Malawi, the nutritional status, morbidity, and mortality among 1,178 children under five were studied during three rainy and three dry seasons. Data were collected at fortnightly home interviews. Nutritional assessment was made twice a year. One hundred and thirty-seven of the children died during the study period, and the probability of dying before the age of five was estimated to 270 per 1,000 children. The mortality risk was related to weight for height (p less than 0.001) and height for age (p less than 0.01) as well as to upper arm circumference (p less than 0.001) and triceps skinfold (p less than 0.05). Mortality among children living in households using the new, piped-water supply tended to be lower than mortality for those using traditional water sources, although the difference was not statistically significant (relative risk 0.4, 95% confidence interval 0.1-1.3).

Child Nutritional Physiological Phenomena↗

PubMed1988

Serum selenium is related to low-density lipoproteins in healthy children but not in children with diabetes.

The serum concentrations of selenium in 13 healthy children and 27 children with type 1 diabetes mellitus were evaluated in relation to serum lipoprotein and apolipoprotein concentrations. In healthy children a correlation was found between serum selenium and both serum cholesterol (r = 0.56; p less than 0.05) and serum triglycerides (r = 0.56; less than 0.05) and their low-density lipoprotein (LDL) + very low-density lipoprotein (VLDL) fractions (r = 0.60 and 0.56 respectively; p less than 0.05), but not their high-density lipoprotein fractions. Associations were also found between selenium and apolipoproteins, especially A II and C II (r = 0.57; p less than 0.05). In diabetic children serum selenium was significantly correlated with apolipoproteins A II and Apo C II, but not with any lipoprotein or lipid or any of their fractions. This study supports the hypothesis that serum selenium is an integral part of the defence system against degradation products associated with LDL and VLDL in young healthy humans. These associations were not found in diabetes, which might suggest that the defence system against lipid peroxidation is less effective in this disease.

Adolescent↗

PubMed1988

Maternal glucose metabolism and infant birth weight: a study in healthy pregnant women.

An intravenous glucose tolerance test (IVGTT) with serum insulin determinations was performed at week 37 of pregnancy in 52 healthy primiparae, selected to provide an increased variation in infant birth weight. A significant relationship was found between infant birth weight and both fasting blood glucose and t1/2 of glucose. Infant skinfold thickness, however, was not correlated independently to any of the parameters of the IVGTT. There was a significant correlation between maternal lean body mass and glucose metabolism, but this could not fully explain the relation between lean body mass and infant birth weight. Maternal fat mass was not significantly correlated to infant birth weight, though it was correlated with serum insulin levels. In the investigated population, fasting blood glucose, t1/2 of glucose, and maternal lean body mass accounted for 27% of the variation in infant birth weight.

Adult↗

PubMed1987

Relative effect of parental birth weight on infant birth weight at term.

The relations between some hereditary and environmental factors and the variation in infant birth weight were estimated by multiple linear regression analyses on a sample of 276 Scandinavian single term pregnancies. Gestational age explained 10.9%, fetal factors (maternal and paternal birth weights and fetal sex) 7.9%, maternal factors (parity, pre-pregnancy weight and height) 5.5% and external factors (adjusted weight gain and smoking) 5.8% of the variation in infant birth weight. It is concluded that maternal and paternal birth weights are rather poor predictors of infant birth weight. Together they explain only 5.6% of the variation in infant birth weight at term.

Analysis of Variance↗

PubMed1987

Maternal fat stores and fat accretion during pregnancy in relation to infant birthweight.

Maternal fat stores and fat accretion during pregnancy were estimated from body weight and skinfold thicknesses and by the factorial method in a sample of 56 Swedish women in their second pregnancies who gave birth to singletons at term. Prepregnancy lean body mass, and not fat mass, were strongly correlated with infant birthweight. Total weight gain was significantly correlated with infant birthweight. A wide range of maternal fat accretion during pregnancy was observed, and the amount of fat accumulated was related to the total weight gain. In spite of this, maternal fat accretion during pregnancy was found to have little bearing on the infant birthweight at term.

Adult↗

PubMed1987

Energy intake and physical activity during pregnancy in relation to maternal fat accretion and infant birthweight.

During the second pregnancy of 56 Swedish women resulting in a term birth, energy intake and physical activity were measured for 3 days at weeks 17 and 33. The values were related to maternal lean body mass, pregnancy weight gain, maternal fat accretion and infant birthweight by multiple linear regression analyses. A significant regression coefficient was found for energy intake at week 17 on maternal fat accretion. Energy intake was not significantly correlated with infant birthweight, not even when physical activity and maternal lean body mass were taken into account. Thus in a well-nourished Swedish population, energy intake is positively related to maternal fat accretion but not to the birthweight of term infants.

Birth Weight↗

PubMed1987

Trace elements and transport proteins in serum of children with Down syndrome and of healthy siblings living in the same environment.

Twenty-two children with Down syndrome (DS), 8 boys and 14 girls, in the age range 5 to 15 years were investigated and compared with a control group of 22 healthy children, 9 boys and 13 girls of the same age group, 9 of them being siblings of patients with DS. Concentrations of iron, copper and zinc in serum were determined by atomic absorption spectrophotometry and serum proteins were quantitated by the radial immunodiffusion technique. The subjects with DS had significantly lower mean serum iron (P less than 0.01) and zinc (P less than 0.001) than the healthy controls. Four DS children had serum iron values that fell below the normal range. In more than 60 per cent of the DS patients the zinc concentration fell below the normal range. The children with DS had significantly higher mean serum copper (P less than 0.05) but lower serum iron (P less than 0.05) and zinc (P less than 0.05) levels than their healthy siblings living in the same family at the time of examination. The DS patients as a group had higher levels of caeruloplasmin (P less than 0.01), haptoglobin (P less than 0.001), orosomucoid (P less than 0.001) and alpha 2-macroglobulin (P less than 0.001) than the healthy controls and compared with their siblings. Except for prealbumin and retinol-binding protein (RBP), no age-related variation in the serum concentrations of the studied proteins was found in the DS patients. Albumin, prealbumin, RBP and transferrin levels were similar in the two study groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1987

Child health and household water supply: a longitudinal study of growth and its environmental determinants in rural Malawi.

The growth of 1029 children under 5 years of age, in rural Malawi, was studied during 1 year before and 1 year after the introduction of a piped water supply system. The study was performed to evaluate the effect of socio-economic and environmental factors, especially water supply, on growth. In general, the first 2 years of life were highly liable to nutritional impairment. The seasonal variation of growth rate was most pronounced in children under 2 years. It was found that crowding, measured both as population density and as members per household, had a negative impact on the growth of younger children. In households utilizing piped water, children did not display significantly better growth when compared with children in households using traditional water sources. Although clean water in itself is vital, it was not enough to improve the growth of young children under the conditions that we have studied. It is suggested that, when providing an improved water supply, sanitation and hygiene education are necessary additions. Other ways of reducing recurrent infections, in combination with effective nutrition during and after episodes of disease, should also be given increased consideration in order to improve growth.

Anthropometry↗

PubMed1985

Selenium supplementation in X-linked muscular dystrophy. Effects on erythrocyte and serum selenium and on erythrocyte glutathione peroxidase activity.

The selenium concentrations in serum and erythrocytes and the erythrocyte glutathione peroxidase activity were determined in 15 boys with the Duchenne type and in 5 boys with the Becker type of X-linked muscular dystrophy before and during long-term selenium and alpha-tocopherol supplementation and compared with values in unsupplemented controls. The purpose of the treatment was to improve the muscular strength. Twelve of the 20 patients had pretreatment levels of selenium in serum that were within the 95% confidence limit of the unsupplemented control children. The values in 2 patients, both with the Duchenne type of muscular dystrophy, fell below this level. Selenium supplementation in a daily dose of 6 micrograms/kg/day for 6 months caused a substantial rise in both serum and erythrocyte selenium, suggesting suboptimal pretreatment body contents of selenium. The greatest increases in both serum and erythrocyte selenium were observed in subjects with initially low selenium levels. Only in 4 of the 20 patients did the selenium supplementation result in a significant rise in erythrocyte glutathione peroxidase activity. As no sure improvement was noted in muscular strength during this treatment period, the Se dose was increased to 20 micrograms/kg/day. This resulted in a further rise in both serum and erythrocyte selenium, but not in erythrocyte glutathione peroxidase activity.

Adolescent↗

PubMed1985

Reduced serum proteins in diabetic children on a twice-daily insulin schedule.

The concentrations of selected proteins of transport and nutrition were investigated in 27 diabetic children and 13 healthy controls by an immunodiffusion technique. The diabetic children had significantly lower mean pre-albumin (p less than 0.001), albumin (p less than 0.01) and orosomucoid levels (p less than 0.05) than the healthy controls. No correlation was observed between age or sex and the blood concentrations of the specific proteins analyzed in this series. Haptoglobin and hemopexin showed positive correlations with serum triglycerides (both p less than 0.01) and slight positive correlations with some of the variables of carbohydrate control. The reduced levels of prealbumin and albumin were not correlated to diabetic control as measured by HbA1, fasting plasma glucose or urinary glucose excretion. The non-physiological distribution site and the abnormal temporal pattern of insulin offered to diabetic children might be the reason for the protein abnormalities found in this study. This is seemingly the first time reduced serum levels of proteins have been reported in diabetic children.

Adolescent↗