Positive after-image, PAI: early erasure by saccadic eye movement or Jendrassik manoeuvre

Positive after-images (PAIs) evoked by low intensity stroboscopic flash are erased by voluntary large amplitude saccadic eye movements. The duration of the PAI is shortened by a Jendrassik manoeuvre. The results suggest that muscle spindle afferent impulses conducted centrally are involved in the erasure phenomenon. The duration of the PAI is modifiable by drugs. The social implications of PAI are considered briefly.     

The effect of glycine on serum luteinizing hormone in adult female rats

The response of serum luteinizing hormone to glycine has been studied during the estrous cycle in adult female rats. I.p. administration of 200 mg of glycine significantly elevated serum luteinizing hormone levels at all stages of the estrous cycle.     

Further characterization of the effects of ultraviolet irradiation of the amphibian egg

UV-irradiation of the vegetal hemisphere of amphibian eggs leads to developmental abnormalities in neural morphogenesis. The possibility that the egg's transient sensitivity to irradiation could be due to pigmentation changes was examined in albino eggs. The tissue specificity of the effects of irradiation was analyzed by exchanging the ectoderm between irradiated and control embryos.     

Distribution of calcitonin cells in the thyroid glands of normal adult rhesus monkey Macaca mulatta.

The calcitonin cells of adult rhesus monkey Macaca mulatta are located in the central region of thyroid along the median axis. The anterior and posterior poles, the isthmus and peripheral regions of thyroid are completely devoid of C cells. The parathyroid also lacks C cells.     

Lipofuscin accumulation in squirrel monkey spinal cord consequent to protein malnutrition during gestation.

The formation of lipofuscin pigment in the anterior horn cells of the cervical spinal cord has shown in the fetuses and neonates under the extrinsic influence of maternal protein deprivation during the gestation period in the squirrel monkeys.     

Somatostatin inhibits the mitogenic effect of thyroliberin.

The effect of somatostatin and of thyroliberin on the mitotic incidence in the organ-cultured anterior pituitary lobe of the rat was investigated, using the colchicine metaphase-arrest technique. It was found that somatostatin added to the culture medium, together with thyroliberin, blocked the mitogenic effect of the latter.     

Quantitative studies on in vitro transformation of hamster chondrocytes.

Hamster chondrocytes could be transformed in a quantitative assay system which used X-irradiated feeder layer cells. Morphological transformation occurred on addition of, 4NQO, but not in control cultures. Differentiation was classified into 3 types (good, poor and none); normal and transformed colonies contained similar proportions of the 3 types.     

Construction of a thin film PO2-electrode using gold paste

A thin film gold electrode for biological oxygen consumption was constructed using gold paste. This electrode is easy to construct, has high sensitivity and is disturbed only slightly by bubbling of the surrounding fluid. As an application, the electrode was used to measure oxygen consumption of the skin and yielded a reasonable value.