Down regulation of bcl-2 by p53 in nasopharyngeal carcinoma and lack of detection of its specific t(14;18) chromosomal translocation in fixed tissues

High levels of bcl-2 protein have been found in a wide variety of human cancers. Since p53 gene inactivation occurs in over half of human cancers, it is possible that loss of p53-mediated repression of bcl-2 gene expression accounts, at least in part, for the frequent abnormalities in bcl-2 protein production seen in tumours. By using immunohistochemical methods, we have analysed thirty-three nasopharyngeal carcinomas for p53 and bcl-2 expression. We found an inverse correlation between the expression of these two proteins ( P  < 0.001). Moreover, we utilized universal oligonucelotide primers of a region 5' to the bcl-2 MBR and at the 3' end of J_H segments to initiate a DNA polymerase chain reaction that amplified these bcl-2-J_H junctures. Of the twelve nasopharyngeal carcinomas expressing bcl-2, none showed a t(14;18) chromosome translocation. These findings may indicate potential mechanisms by which bcl-2 regulates apoptosis.     

Hydroxocobalamin. II. Absorption from the Site of Injection and Uptake by the Liver and Calf Muscle in Man

Labeled hydroxocobalamin, administered intramuscularly in man, is absorbed more slowly from the site of injection and deposited in the liver andcalf muscle to a degree equal to or higher than that of cyanocobalamin at anequivalent dose. These findings, together with those reported in Part I ofthis paper, suggest the applicability of hydroxocobalamin as a long-actingvitamin B₁₂ in man. These conclusions, however, require the support to be obtained from long-range observations on patients with vitamin B₁₂ depletion.

Submitted on June 6, 1961 Accepted on August 1, 1961     

Solubility in amide-water cosolvent systems: a thermodynamic view

The solubility of methyl p-hydroxybenzoate was determined in a series of amide-water cosolvents in the temperature range 25–40 °C. Thermodynamic values for the transfer of the ester between the cosolvent system were calculated using a method which permits a focus on the effects of amide alkylation. The results are interpreted in terms of hydrophobic bonding principles which suggest that the alkyl groups on the amide detract from amide-water interaction and enhance amide-ester interaction.     

PHARMACOKINETICS OF ALCURONIUM IN ELDERLY PATIENTS UNDERGOING TOTAL HIP REPLACEMENT OR AORTIC RECONSTRUCTIVE SURGERY

The pharmacokinetic behaviour of alcuronium was studied in threepatients undergoing resection of an aortic aneurysm, and inanother two patients undergoing total hip replacement (groupI). A control group of five elderly patients undergoing relativelyminor surgery was included (group II). In group I patients,the values of the pharmacokinetic parameters such as plasmaclearance, elimination half-life and the apparent volume ofdistribution of the drug were found to be comparable to thoseobtained in normal young patients in previous studies. The groupII patients, however, were found to have a prolonged eliminationhalf-life as a result of reduced plasma clearance, possiblyan age-related effect. The differences between these two groupsof patients may be explained by the differences in the extentof haemorrhage and fluid replacement or changes in blood circulation,or both. However, alcuronium must still be used cautiously inboth groups of patients, especially in the light of a recentfinding that patients undergoing aortic reconstructive surgeryhave a high frequency of functional renal failure after operation.     

Pigmented carcinoid tumour of the thymus

An asymptomatic thymic tumour, classified as a carcinoid tumour on the basis of its light and electron-microscopic appearances, is described. This tumour was atypical in having foci of melanin pigmentation, the pigment being contained in dendritic melanocytes and melanophages. We suggest that the pigmented cells are not neoplastic and represent latent thymic melanoblasts stimulated in some way by the carcinoid tumour. Alternative explanations are discussed.