Zinc levels and blood enzyme activities in Egyptian male subjects with retarded growth and sexual development

Human zinc deficiency: discovery to initial translation

Ananda S Prasad first suspected zinc deficiency in 1958 after he, at the request of James A Halsted, evaluated a patient with severe iron deficiency. In addition to iron deficiency, the patient appeared ∼10 y old and was severely stunted and prepubertal, though his chronological and bone age were much older. He also had hepatosplenomegaly and ate clay. The condition was not rare in that 11 cases were reported. In 1961 Prasad joined the Vanderbilt Nutrition Group led by William J. Darby at the US Naval Medical Research Unit-3, Cairo, Egypt. Prasad et al. studied 40 males similar to the index case. Contrasts with the index case included no clay eating and infection with schistosomiasis and hookworm. Zinc kinetics confirmed the zinc deficiency. Endocrine studies showed hypopituitarism. Treatment with zinc and an omnivorous diet was more efficacious for growth than no treatment, diet alone, or iron and diet. Later, Halsted et al. confirmed these findings in stunted Iranian farmers. The key role of diet in the illness became evident when Prasad found 16 severely stunted farmers from 2 oases who were not infected with schistosomiasis or hookworm. Later, Reinhold et al., in Halsted's group, reported that phytate and other indigestible zinc-binding ligands in unleavened bread prepared from high-extraction wheat flour suppress zinc absorption.

Origins of the Interdepartmental Committee on Nutrition for National Defense, and a Brief Note Concerning Its Demise

The Interdepartmental Committee on Nutrition for National Defense was established in 1955 after malnutrition was found common among troops of the Republic of Korea and of the Republic of China (Taiwan). The initial purpose was identification of nutrition problems among military personnel (later, and among civilians) of countries of "special interest." Surveys measured status, assisted with the establishment of nutrition resources, and facilitated investigator learning and research. A major initial accomplishment was the preparation of a manual of procedures, which evolved into the 1963 Manual for Nutrition Surveys. The first 3 surveys, conducted in 1956, were of the armies of Iran, Pakistan, and Korea. They identified poor nutrition status in some troops, provided a basis for improving rations, and confirmed the effectiveness of the methodology. These surveys were followed by surveys of 30 additional countries that in nearly all instances included civilians and provided a basis for programs and the institutions for improvement of nutrition. On August 1, 1967, the program was reorganized and the Nutrition Program, CDC, based at NIH, was created. This occurred in response to the 1967 Partnership for Health Amendments "to make a comprehensive survey of the incidence and location of serious hunger and malnutrition, and health problems incident thereto, in the United States and to report these conditions to the Congress." The Ten State Nutrition Survey was done in response. Findings of malnutrition, especially in populations of low-income states were politically unwelcome in some quarters. Consequently the program was redirected, and, according to 2 observers, the survey findings were suppressed.

Effect of urinary bilharzial infection on male pubertal development and endocrine functions

One hundred seventy-five males aged 9-20 years were selected. The subjects comprised two groups; controls and patients infected with urinary bilharziasis not associated with any other parasite. Pubertal development was assessed. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and progesterone were determined by radioimmunoassay procedure. Delay in pubertal development was evident in the normal control group as indicated by higher chronological age mean values at the various stages as compared to other world norms. Urinary bilharziasis exaggerated the delay in pubertal development as compared to that in the control group. In relation to the control group, the group with urinary bilharziasis had higher levels of serum FSH and LH, which were significant only at stages III and IV. No significant difference was noted between the two groups for serum testosterone and progesterone levels, except for the high progesterone mean value at stage V in the group with urinary bilharziasis.

Sexual maturation and growth pattern in Egyptian boys

The mean ages of attainment of successive stages of puberty were estimated in a cross-sectional sample of 453 Egyptian schoolboys from a semi-urban area of Cairo, ranging in age from 9 to 17 years. The stages of puberty were as defined by Tanner (1962). The mean age of onset of puberty (stage 2) was 11.1 years, assessed either by genitalia or by pubic hair. Stage 5 occurred at 16.2 years, again both for genitalia and pubic hair. The time interval between these ages, 5.1 years, was 2 years longer than for British or Chinese boys. There was a highly significant effect of social class on the mean ages of attainment, and the heights and weights of the boys were also related to social class, the class 1 boys being taller and heavier than Tanner's British boys.

Effect of kwashiorkor on absorption and excretion of N, fat, and minerals

Balance experiments were carried out on 6 children being treated for kwashiorkor. The intakes and excretions of N, fat, Na, K, Ca, Mg, P, Cu, Zn, Mn, and Cr were measured. The absorptions were all thought to be in the normal range and the retentions were high. The stools were bulky and contained much undetermined matter, probably unavailable carbohydrate derived from the matooke which formed part of their diet. In the light of previous and present findings the ratios of K/N and Mg/N retained, though higher than those found in muscle or in the whole body, cannot be taken to mean that the children were K or Mg deficient.

Increased retention of orally administered zinc and raised blood cell zinc concentrations in iron-deficient rats

1. Rats were made severely iron-deficient by feeding with Fe-deficient diets, which contained adequate amounts of zinc.

2. Ten days after an oral dose of 250 μg65Zn the Fe-deficient rats had retained 17% whereas control rats had retained only 8% of the dose.

3. When unlabelled Zn was given intravenously to the Fe-deficient and control rats there was a reduction in retention of the orally administered 65Zn. This effect was not produced when Fe was given before the oral dose of 65Zn.

4. Total body Zn, whole blood Zn and plasma Zn concentrations of the rats were measured by atomic absorption spectrophotometry. Both the Fe-deficient rats and the control rats had the same total body Zn calculated as a proportion of body-weight. The plasma Zn concentrations were normal in all the animals. Blood cell Zn concentrations in the Fe-deficient animals were raised.

5. The blood cell Zn concentration was directly related to the reticulocyte count in all the rats.

6. It was concluded that Fe and Zn are absorbed by different metabolic pathways, and that there is an increased turnover of Zn in the Fe-deficient rats, possibly related to the short lifespan and increased Zn concentration of Fe-deficient rat erythrocytes. In the rat abnormalities of Zn concentration can only be considered significant if Fe status is also known.