An autoradiographic analysis of [3H]alpha-bungarotoxin distribution in the rat brain after intraventricular injection

Purified alpha-bungarotoxin was isolated by chromatography and made radioactive with tritium ([3H]acetamidino-alpha-bungarotoxin). Infusions of [3H]alpha-bungarotoxin alone or preceded by tubocurarine or atropine were given into the third ventricle. 2. 12, or 24 h after injection the brains were prepared for autoradiography. Injections of alpha-bungarotoxin (radioinert) in buffer, or of [3H]parathyroid hormone in buffer, served as controls. The various patterns of labeling suggest the presence of nicotinic-cholinergic neurons within the arcuate and basolateral regions of the hypothalamus including the supraoptic and suprachiasmatic nuclei and, in addition, the central nucleus of the amygdala.

Pyorrhoea as cause of pyrexia

Three patients with fever and malaise, one of whom also had joint pains, were extensively investigated before their condition was attributed to dental sepsis. Each patient recovered fully after appropriate dental treatment. Dental sepsis should be added to the list of possible causes of pyrexia of undetermined origin, and a routine dental examination should be carried out in each case.

A study of some factors concerned in the schooling of visually handicapped children

Sixty children integrated into the fully-sighted school system and 34 children attending partially-sighted schools were assessed. All were using low vision aids. It was found that there was little difference in acuity, parental or school support, but the integrated children tended to be more intelligent and came from a higher socioeconomic group. More children could avoid special schools if given appropriate services at an early age and assessment should be by a multidisciplinary team.

Structure and evolution of transplantation antigens: partial amino-acid sequences of H-2K and H-2D alloantigens

Techniques for the amino acid sequence analysis of subnanomole quantities of polypeptides have been applied to characterize beta2-microglobulin and transplantation antigens of the mouse isolated from spleen cells by indirect immunoprecipitation. Eleven residues were identified throughout the NH2-terminal 27 residues of the beta2-microglobulin; all were identical to residues seen at the corresponding positions of beta2-microglobulins from other species. Two K and two D transplantation antigens were examined and the following generalizations emerged from the limited partial amino-acid sequence data: (1) the K and D molecules are homologous to one another; (2) they do not show amino acid sequence homology with immunoglobulins; (3) the two K and two D molecules differ from one another by multiple amino acid substitutions; and (4) the K molecules as a class cannot be distinguished from the D molecules as a class. The genetic and evolutionary implications of these observations are discussed.

Preliminary amino acid sequences of transplantation antigens: genetic and evolutionary implications

Preliminary amino acid sequence data on the transplantation antigens of mouse and man have led to provocative hypotheses about the genetic organization and evolution of genes coded by the major histocompatibility complex of mammals. New microsequencing techniques should permit a detailed analysis of these gene products and an eventual choice among the alternative hypotheses now posed. These data have made it apparent that the H-2 complex is a fascinating and complicated chromosomal region which will continue for some time to intrigue immunologists, geneticists, biochemists, and cell biologists.

The surrogate functions of lines in visual perception: evidence from antipodal rock and cave artwork sources

Lines in outline pictures may function as surrogates for features of the visible environment, without explicit tutoring in a convention (unlike representation in words). This interpretation of line representation is supported by the finding that drawings from ancient sources—in antipodal regions of the world—contain outline depiction of the same features as are found in modern outline sketches.

Prevalence and treatment of vitamin D deficiency in children on anticonvulsant drugs

Bone metabolism was studied in a group of adolescent epileptic children given anticonvulsant drugs and compared with a matched group of nonepileptic children living in the same institutional environment. Biochemical evidence of vitamin D deficiency was more common in treated children than in controls, and 3 out of 60 children taking anticonvulsants had radiological evidence of rickets. The signs of vitamin D deficiency could not be corrected by giving 5 μg (200 IU) cholecalciferol daily for 12 weeks, but disappeared after treatment with 75 μg (3000 IU) cholecalciferol weekly for a further 12 weeks. Thus, in a residential home in southeast England the increased nutritional requirement for vitamin D caused by the administration of anticonvulsants to adolescent epileptic children was of the order of 10 μg cholecalciferol per day. It is likely that all epileptic subjects on anticonvulsants have increased needs for vitamin D and we advise regular supplementation of their diets. It is also shown that serum concentrations of γ-glutamyl transpeptidase, 5′nucleotidase, and leucine aminopeptidase are raised in children taking anticonvulsants. It seems likely that this is caused by drug induction of membrane-bound enzymes in the liver.

Effect of phenobarbitone treatment on vitamin D metabolism in mammals

1. The metabolism of radioactive cholecalciferol was studied in control and phenobarbitone-treated rats and pigs.

2. Treatment with phenobarbitone enhanced the appearance in plasma of 25-hydroxycholecalciferol (peak IV on silicic acid chromatography), and of more-polar metabolites (peak V), but not of the most-polar metabolites (peak VI). Peak IV had the chromatographic properties of authentic 25-hydroxycholecalciferol (25-HCC) and had biological activity.

3. There was no effect on the appearance of peaks V and VI in plasma after an injection of radioactive 25-HCC.

4. Treatment with phenobarbitone enhanced the excretion of metabolites of radioactive vitamin D3 in bile. These metabolites were largely water-soluble conjugates of peaks IV, V and VI, which included glucuronides. Peak IV in bile was not identical with 25-HCC.

5. Prolonged treatment with phenobarbitone depleted the tissue radioactivity of rats given radioactive vitamin D3.