The venous plasma free amino acid levels of mother and child during delivery. 3. In a lower socio-economic group of a refugee area in Karachi, West Pakistan, with special reference to the "small for dates" syndrome

Boosting of secretory IgA antibody responses in man by parenteral cholera vaccination

The occurrence of specific antibodies to Vibrio cholerae lipopolysaccharide in serum, milk, and saliva of Pakistani women from a very low socioeconomic group was studied before and after a single subcutaneous cholera vaccination. Before immunization all women had low levels of specific antibodies in serum, primarily of IgM class, and in many cases cholera IgA angibodies were found in milk and saliva as well, indicating earlier natural exposure. The vaccination consistently induced a marked rise in serum antibody titer, and notably also produced significant titer increases in 70% of the milk and in 45% of the saliva samples. Whereas the serum antibodies induced were predominantly of the IgG class, secretory IgA was responsible for most of the titer increase in the secretions. The results indicate that parenteral cholera vaccination can boost local secretory IgA antibody responses in intestinally primed individuals.

Overt and hidden forms of chronic malnutrition in the rat and their relevance to man

We have examined the physiological weight changes seen in rat dams and their offspring as sequelae of either an overt or a hidden form of chronic protein malnutrition. In the overt model, which was produced by feeding dams a very low protein diet (6% casein) starting 5 weeks prior to conception and continued through lactation, the females showed significant weight losses at all ages compared to dams maintained on a normal diet (25% casein). This caused the malnourished 6% dams to have offspring that were categorized as small-for-date at birth in terms of their weight indices and peripheral metabolic profiles. Also, the inadequate milk production of these dams resulted in their pups displaying the almost total failure of growth (greater than 60% decreases in body weights) and peripheral imbalances characteristic of infantile marasmus by day 8 of lactation. Consequently, at all times examined the 6% dams and pups showed most of the typical responses seen in the more severe forms of in utero and lactational malnutrition of mankind. In contrast, the hidden form of malnutrition produced by feeding dams a somewhat higher protein diet (8% casein) throughout the same time periods caused no marked weight losses by these females during their pregnancy compared to the normal dams. Although the 8% pups had the same birth weight indices as the normal offspring, previous data from our group have indicated that the 8% progeny show many metabolic imbalances at birth which are indicators of severe gestational malnutrition in humans. Moreover, while the 8% dams displayed lactational insufficiencies as noted by their pups retarded postnatal growth, nursing of these offspring by 25% dams allowed them to maintain a normal lactational growth curve. However, not only was this cross-fostering unable to rehabilitate most of the prenatally determined biochemical alterations affecting the 8% pups but, additionally, this form of malnutrition will remain undetected if weight indices alone are used as assessors of normalcy. Thus, it appears that the 8% rats may serve as a useful model for the hidden forms of malnutrition in man.

Anthropometric and biochemical changes during pregnancy in Asian and European mothers having well grown babies

At this hospital, about a third of all mothers are Asian. Although generally they have smaller and lighter babies, many Asian mothers achieve similar standards of intrauterine growth to the European mother. This paper describes the nutritional status of Asian and European mothers having well grown babies. Twenty eight European and 11 Asian mothers, who had a normal past obstetric history and a normal present pregnancy resulting in a well grown baby, were studied throughout pregnancy. At each visit, weight, skinfold thickness, and mid-upper arm circumference were measured and biochemical measurements of nutritional status were performed (serum albumin, transferrin and alkaline ribonuclease, plasma amino acids and nitrogen partition of urine). Asian mothers were fatter than European mothers at booking and put on more fat during the second trimester. At the same time, the biochemical tests suggested that the Asian mothers had a higher plane of nutrition. It seems that if the Asian mothers are well nourished in the second trimester, they can achieve a standard of intrauterine growth comparable to the Europeans.

Plasma free amino acid levels during the initial rehabilitation of protein-energy malnutrtion with protracted diarrhoea using a free amino acid--glucose diet

This study intends to assess, by ion-exchange chromatography of free amino acid levels of peripheral blood plasma, the amino acid absorption of severely growth retarded infants with protracted diarrhoea, during the initial period of rehabilitation. Eleven infants from a very low socio-economic group of a developing country, with nutritional marasmic growth retardation and prolonged diarrhoea, were treated for a period of 10 days with a commercially available free amino acid--glucose diet (Vivonex, Pfrimmer Co., Erlangen, Germany). Excessive hyperprolinaemia characterized the plasma aminogram before treatment. After initial rehabilitation with this diet, the plasma analyses showed very low branch-chained and cystine levels, and marginally high alanine, glycine, and proline levels. It seemed that the free amino acids could not be absorbed quickly enough to meet with the high supply of glucose. Furthermore, this investigation supports the assumption that cystine is an essential amino acid in malnourished infants. In spite of normal or high human growth hormone levels, somatomedin was not detectable in pooled samples from these severely growth retarded infants.

Subclinical protein-energy malnutrition in under-privileged Ethiopian mothers and their newborn infants

An increased glycine/valine ratio in the maternal and cord vein plasma was observed in under-privileged women and their newborn babies in Ethiopia. There was a delay in the decrease of branch-chained amino acids during the immediate neonatal period. These findings indicate malnutrition in utero and are identical with those of a previous study in an under-privileged group in Pakistan. A reduced cord/maternal ratio of tyrosine and methionine was found in the Ethiopian material, indicating placental dysfunction of unknown origin.

Influence of jejunoileal bypass on protein metabolism during pregnancy

Management of the pregnant patient who has undergone operation for jejunoileal bypass poses many problems for the attending obstetrician. Several recent studies have broadened our knowledge of this group of patients. Unfortunately, the significance of this form of weight loss upon the developing fetus is at best only poorly understood. In our study, amino acid chromatography was performed at 34 weeks' gestation and at delivery in order to assess the impact of this procedure upon maternal and fetal (cord blood) amino acid concentrations. Results suggest that protein metabolism in the patient who has had intestinal bypass without resulting complications and in her fetus is comparable to that in normal pregnancy. Altered amino acid profiles were observed in one twin gestation and in one patient who continued to lose weight throughout pregnancy. The significance of these observations is discussed with respect to the relationship of protein deprivation to neonatal development.

Escherichia coli O antibody content in milk from healthy Swedish mothers and mothers from a very low socio-economic group of a developing country

The antibody content of milk from healthy Swedish mothers was compared with that of milk from mothers of a very low socio-economic group in a developing country. Antibodies of various immunoglobulin classes against E. coli O antigens were determined with the enzyme-linked immunosorbent assay (ELISA). The milk antibodies which mainly belonged to the secretory IgA class appeared in similar concentrations in milk from the two groups using E. coli antigens of Swedish as well as Pakistani origin. The secretory IgA antibodies could be demonstrated in the stool of the breast-fed infants of the undernourished mothers. Also the concentration of serum IgG and IgA antibodies to E. coli O antigens were similar in the Pakistani and Swedish mothers. The serum IgM antibody levels of the Pakistani mothers were higher, however, presumably due to a higher frequency of infections. It was noted that the milk production decreased considerably upon the hospitalization of the healthy and well-to-do Swedish mothers. The small milk volumes of the undernourished Pakistani mothers suggest that the lactation failure observed was mainly due to inadequate milk flow and not to decreased milk quality. The results indicate the necessity of studying the nutritional, psychological and social factors responsible for low milk yield and add yet another reason to stimulate prolonged breastfeeding.

Amino acid metabolism during starvation in human pregnancy

To evaluate the factors regulating gluconeogenesis in pregnancy, plasma amino acid levels were determined during the course of an 84-90 hr fast in physically healthy women studied during wk 16-22 of gestation (before undergoing therapeutic abortion), and in nonpregnant controls. The effect of pregnancy on the glycemic response to exogenous alanine administration during starvation was also investigated. In the nonpregnant group fasting resulted in a 2- to 3-fold increase in the levels of plasma valine, leucine, isoleucine, and alpha-aminobutyrate, while the concentration of alanine and glycine fell. In the pregnant group, the levels of most amino acids were significantly reduced in the postabsorptive state. With starvation, the plasma concentration of alanine fell more rapidly in the pregnant group and was significantly below that of the nonpregnant subjects for the first 60 hr of the fast. In contrast, a significant elevation in plasma glycine, serine, and threonine was observed in the pregnant group after 84 hr of fasting, whereas similar increments were not demonstrable until after 10 days of fasting in previously studied nonpregnant obese subjects. Paralleling the changes in maternal plasma, amniotic fluid levels of valine, leucine, and isoleucine increased while that of alanine fell during the fast. Although the plasma glucose concentration was lower in the pregnant group at termination of the fast, intravenous alanine administration (0.15 g/kg), resulted in a prompt, comparable increase (20-25 mg/100 ml) in plasma glucose in both groups of subjects. It is concluded that (a) pregnancy accelerates and exaggerates the hypoalaninemic and hyperglycinemic effects of starvation; (b) lack of key endogenous substrate rather than altered intrahepatic processes may limit hepatic gluconeogenesis in pregnancy and contribute to gestational hypoglycemia; (c) maternal caloric deprivation profoundly alters the levels of amino acids in amniotic fluid.