Ethics: responsible scientific conduct

Body composition and measures of obesity were evaluated in 59 subjects with myelomeningocele (MMC), aged 0.3-29 y, by anthropometry and measures of body cell mass (BCM) and intra- and extracellular water (ICW and ECW), derived from total body potassium and deuterium-isotope dilution; these results were compared with reference data. Body composition was normal in preambulatory children with MMC. Beyond ages 3-4 y there was significant depletion of BCM and total body water, with maldistribution of water (increased ECW and decreased ICW) and increased percentage body fat above that expected for age and sex. These findings were more pronounced in females and in those with high lesions, and were less pronounced in those who remained ambulatory. These changes may result in metabolic and nutritional maladaption during stress. The relation of BCM, total body water depletion and increased ECW to decreasing ambulatory activity suggests that early nutritional and mobility programs warrant further study.     

Zinc deficiency. A public health problem?

Zinc deficiency occurs in individuals and populations whose diets are low in sources of readily bioavailable zinc such as red meat, and high in unrefined cereals that are rich in phytate and dietary fibers. Dietary zinc deficiency was described nearly three decades ago among the poor of the Middle East. It is now known to occur in children and adolescents from widely diverse areas including Egypt, Iran, Turkey, China, Yugoslavia, Canada, and the United States; and among pregnant women from Iran, Turkey, the United Kingdom, Australia, and the United States. Major manifestations include retarded growth and development and an increased incidence of pregnancy complications. Other manifestations may include suppressed immunity, poor healing, dermatitis, and impairments in neuropsychological functions. Precise information as to the numbers of people affected by dietary zinc deficiency is not available. Even so the nature of diets associated with zinc deficiency suggests that mild deficiency is common in some populations.     

Learning and memory impairment in adult rats due to severe zinc deficiency during lactation

In a series of three experiments, adult rats who suffered severe zinc deficiency and/or undernutrition during lactation were tested in a 17-arm radial maze for working memory, reference memory, forgetting and learning. In Experiment 1, eight out of 17 arms were baited. The zinc deficient (ZD) and undernourished (PF) rats revealed a learning deficit when compared to adequately nourished rats (AL). ZD rats also appeared to display a loss of working memory. No evidence of loss of reference memory was observed among any of the groups. A reverse learning procedure was used in Experiment 2 to test the same rats used in Experiment 1. ZD rats were significantly inferior in performance of the reverse learning task compared to the AL and PF rats. No significant differences in performance were noted between the AL and PF rats. Although all groups displayed forgetfulness from Experiment 1 to Experiment 2, no significant differences in forgetfulness were evidenced among the groups. In Experiment 3, all 17 arms were baited. The ZD rats displayed a significant working memory deficit as compared to the AL and PF rats. No significant differences in working memory between the AL and PF rats occurred. The possibility that the differences in performance were due to differences in food motivation or attention was considered and rejected. It was concluded that ZD rats experienced a severe learning deficit and some working memory deficit while the PF rats experienced a mild learning deficit as compared to the AL rats.     

Spectral electroencephalographic correlates of iron status: Tired blood revisited

For some time, clinical reports have described impairment of affective and cognitive functions in iron deficient persons. Recent studies suggest that both brain biochemistry and cognitive performance capacity may be disrupted by inadequate intake of dietary iron, but the relationship of the possible neurophysiological effects to psychological ones is unclear. To examine the relationship of iron status to simultaneous measures of cortical activation and cognitive performance, 8 channels of electroencephalographic (EEG) data were recorded during a resting period and during the performance of several cognitive tasks in two groups of men. The EEG data were spectrally analyzed, and measures of total power and frequency of peak power in each of several bands of the power spectrum for each channel were used as predictors in multiple regression analyses with serum iron and serum ferritin as alternative criteria. Measures of power in the delta frequency in the resting period appeared relevant to iron status in both groups, perhaps indicating alertness or arousal level. Consistently in these regressions, the asymmetry of the EEG appeared relevant to iron and ferritin. These findings suggest that the combination of EEG and performance measures may help characterize the neuropsychological effects of trace element nutrition.     

Zinc deficiency during the latter third of pregnancy: effects on fetal rat brain, liver, and placenta.

The effects of zinc deficiency during the last third of gestation on the growth and development of the fetal rat at term were investigated. Zinc deficiency resulted in anorexia and weight loss of the pregnant dams. Fetuses from such dams displayed intrauterine growth retardation when compared with fetuses from pair-fed or ad libitum-fed controls given adequate zinc. Although the brains of the zinc-deficient fetuses were smaller than those of the controls, the brain was relatively spared while the liver was severely affected. The total cell number was reduced and there was an apparent increase in cell size in the brains of zinc-deficient fetuses in comparison with the brains of the controls. The growth failure of the zinc-deficient liver resulted in a smaller complement of total DNA, RNA, protein, and lipid, and there was less incorporation of [3H]thymidine into DNA in the liver. The placenta appeared to be only marginally affected by the zinc deficiency.     

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.