Renal Failure After Radiological Contrast Media

Over a 12-month period four patients developed acute renal failure after undergoing radiological investigations using contrast media. Though the incidence of serious complications is low, the possibility of adverse side effects must be weighed against the usefulness of the information provided by these techniques.     

Seasonal changes in radioiodine uptake and epithelial cell height of the thyroid gland in the freshwater teleosts Esomus danricus (Ham.) and Mystus vittatus (bloch) under varying conditions of illumination

Summary The thyroid gland of Mystus vittatus and Esomus danricus showed seasonal activity in its epithelial cell height and radioiodine uptake. These two indices of activity agree in E. danricus. Under normal photoperiods both species exhibited two phases of optimum activity, one in April through May, the other in September. The active periods were characterized by high iodine uptake and increased follicular cell height. These peaks of activity alternated with more quiescent phases, minimal iodine uptake and low follicular epithelium. In specimens exposed to constant illumination the active and quiescent phases were advanced by two months. But for this change the general pattern of activity was the same as that in animals kept under normal photoperiodic conditions. Specimens subjected to total darkness showed a higher level of activity throughout the year in comparison to the other two groups. However, a distinct seasonal cycle, which was evident with normal photoperiods and continuous illumination, was absent in total darkness.I am greatly indebted to Dr. A. G. Sathyanesan, Banaras Hindu University, for his encouragement, and to Professor S. P. Ray-Chaudhuri, Banaras Hindu University, for providing laboratory facilities.     

Studies with bovine parainfluenza - 3 virus in u.a.R. (Egypt)

A bovine strain of myxovirus parainfluenza-3 (MP3) virus, designated S virus, was isolated from lung tissue collected from cattle with respiratory illness in 1963. The virus agglutinates mammalian and avian erythrocytes, and is sensitive to ether, sodium desoxycholate and trypsin. It grows in primary calf kidney, buffalo kidney, dog kidney, camel kidney and MS cell cultures. The S virus forms well-defined plaques in buffalo and calf kidney cells on the 5th or 6th day after inoculation. Examination of cell cultures following inoculation with S virus revealed giant cell formation, and introcytoplasmic and intranuclear inclusions. At 37 degrees C the virus titer dropped from 10(10.4) to 10(2.6) in 3 days. Virus was completely inactivated at 56 degrees C within 15 minutes. Growth-curve studies in tissue culture monolayer cells revealed a latent period of 10 hours. The intracellular virus titer was slightly lower than that of extracellular virus. The isolate was identified as MP3 virus by serum neutralization and hemagglutination-inhibition tests. Antibodies (HI) to S virus were shown to be present in a significant proportion of Egyptian cattle. The epidemiological significance of MP3 (bovine strain) virus in U.A.R. is discussed.     

Argyrophile and argentaffin reactions in individual granules of enterochromaffin cells of reserpine treated guinea pigs

Summary The individual granules of enterochromaffin cells of normal and reserpine treated guinea pigs have been studied by staining slides of the duodenum first by an argentaffin method and subsequently by an argyrophile method. Some argentaffin cells can be shown to contain not only argentaffin granules, but also granules that are purely argyrophile. The relative number of such argentaffin cells is greatly increased following administration of reserpine, as depletion of their 5-hydroxytryptamine content converts argentaffin granules into purely argyrophile ones. On the basis of this finding it is confirmed that the argyrophile granule is merely an argentaffin granule depleted of its 5-HT content, and that the argyrophile (nonargentaffin) and the argentaffin cells represent different phases of a secretory cycle.This investigation was supported by a grant from the Indian Council of Medical Research. I am grateful to Ms. Ciba of India Ltd. for making available reserpine (Serpasil) and solvent for reserpine. It is a pleasure to thank Mr. Anand Parkash for technical assistance and Mr. M. L. Sharma for the photographs.     

Methionine-oxidized horse heart cytochromec. III. Ascorbate reduction and the methionine-80-sulfur-iron linkage

The ascorbate reduction of the CT-cytochromes—two chemically generated forms of horse heart cytochrome c, F^III and F^II, with both methionines, 80 and 65, as methionine sulfoxides, no iron-sulfur linkage, and potentiometric and physiological oxidoreduction properties distinct from those of the native protein and one another (J. Pande et al., 1987)—has been investigated using a stopped-flow technique. The reaction was monitored at 550 nm, and studies were conducted in 10 mM phosphate +0.17 M NaCl buffer,pH 7.4. Both CT-cytochromes are reduced by triphasic profiles, a faster and an intermediate ascorbate-dependent reaction and a slow, ascorbate-independent process. Both CT-cytochromes contain three molecular forms in slow equilibrium, two reducing directly by reaction with ascorbate and a third through conversion to one of the reducible forms. Like the reaction of the native protein, the ascorbate dependence of both the rapid and the intermediate process is nonlinear, approaching saturation values at high concentrations. The ascorbate profiles of the pseudo-first-order reduction constants are typical of the model for the reduction reaction of the unmodified protein, binding followed by a first-order reduction reaction (Myer et al., 1980; Myer and Kumar, 1984), but with distinct kinetic parameters, the first-order reduction constants and the protein-ascorbate stability constants. It has been concluded that the functional-conformational differences between the two CT-cytochromes are not operational to any significant extent in the reduction reaction with ascorbate. The methionine-80-sulfur-iron linkage of the protein is not a crucial requirement for the ascorbate reduction of the protein. The mechanism of the reaction in the main is also insensitive to the replacement of Met-80-S from heme coordination and/or the associated conformational-oxidoreduction properties of the protein. Of the two aspects of the reaction, the efficiency of the electron-transfer reaction and the stability of the ascorbate dianion-protein complex, the former is dependent on the integrity of the structural-conformational state of the molecule.     

Cloning and expression of ovine placental lactogen

Ovine placental lactogen (oPL) is active in a wide range of GH and PRL assays, a property that it shares with human GH (hGH). In addition, oPL is one of a small number of hormones that bind the human GH receptor with high affinity. In order to compare the sequence of oPL to the sequences of other members of the GH family, full-length cDNA clones have been isolated. These clones predict that the full sequence of oPL contains 198 amino acids preceded by a 38 amino acid signal sequence. The mature oPL sequence includes six cysteine and two tryptophan residues and shows substantially more identity to bovine PL (67%) and oPL (49%) than to mouse (31%) or human (25%) PL or to oGH (28%) or (26%) hGH. Like the natural hormone, oPL expressed in mammalian tissue cells binds with high affinity to a soluble form of the recombinant hGH receptor. Thus, oPL binds to the human receptor in spite of having a sequence that is considerably divergent from hGH. Interestingly, the sequence of oPL differs from hGH at most of the amino acids recently found by mutagenesis studies to be important residues in the binding of hGH to the human receptor.