200 Asian 300 African, Chinese, or Scottish children were examined for clinical, biochemical, and radiological evidence of vitamin-D deficiency. Among the Asians there were 10 with florid rickets and 15 with subclinical rickets. Among the African, Chinese, and Scottish children there were no cases of florid rickets and only 7 cases of subclinical rickets (3 African, 3 Chinese, and 1 Scottish). Loss of metaphyseal definition is considered to be the radiological pattern of minimal active rickets and metaphyseal bands to represent the healing stage. Serum 25-hydroxycholecalciferol concentrations were low in clinical and subclinical minimal active rickets although there was some overlap with the wide range found in the "normal" group. Elevated serum-alkaline-phosphatase levels alone should not be regarded as indicating vitamin-D deficiency. The continuing prevalence of rickets in Asian children and in particular among schoolchildren warrants immediate action, which is long overdue.

Africa↗

PubMed1976

Marginal and extramarginal cortical lesions and visual discrimination by cats.

Seventy-five cats learned a shape discrimination with zero, one, or two irrelevant cues. They were then subjected to sham operations (n = 34), ablation of the marginal and splenial gyri (n = 9), or lesions in the extramarginal (EM) cortex. The 32 EM cats comprised four groups, three with small (EM1, n = 9), intermediate (EM2, n = 10), and large (EM3, n = 9) decortications, and a fourth group with both EM lesions and heavy degeneration in the lateral geniculate nucleus (LGN, n = 4). The cats with marginal or extensive extramarginal lesions were severely impaired in shape and size discrimination. Two lines of evidence indicate that their behavioral defects resulted from different neural dysfunctions. (a) The errors made by marginal gyrus cases increased sharply as a function of the number of irrelevant cues present in shape discrimination training; no other group, including Group EM3, was affected by this variable. (b) Cats with extramarginal ablations and strong LGN degeneration were no more severely impaired than were subjects with comparable extramarginal damage and little or no LGN degeneration. While the nature of the two kinds of deficits remains unclear, they seem parallel to those following posterior cortical lesions in monkeys.

Animals↗

PubMed1976

The search for cerebral dominance in monkeys.

Twelve monkeys with statistically significant and consistent manual preferences on three handedness tests were subjected to unilateral ablations in the association cortex. Eight received lesions in the foveal prestriate cortex, and four lesions in the dorsolateral frontal cortex; half the subjects in each group were operated on the dominant, and half on the nondominant hemisphere for handedness. The unilateral posterior preparations were significantly inferior to the control group of four unilateral frontals and five sham operated monkeys on three series of visual pattern discrimination problems. No evidence was obtained that lesions in the nondominant hemisphere. The results of this and four other experiments indicate that there is no cerebral dominance for problem-solving in monkeys. Recent research indicates that handedness in rhesus monkeys is only superficially similar to handedness in humans; thus, monkeys appear to lack cerebral dominance for handedness as well as for cognitive behavior.

Animals↗

PubMed1976

Use of embryo-transfer technique in the diagnosis of bovine uterine-tube pathology.

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Animals↗