Granule formation in rat myeloid cells

Summary Rat bone marrow was fixed in glutaraldehyde, postfixed in osmium tetroxide, and processed for electron microscopy. The myeloid cells were arranged in order of maturation according to their successive compartments.On the basis of their differences in form, substructure, volume, and density five morphologically distinct types of developing granules are to be observed in neutrophil, two in eosinophil, and four in basophil, cells. Primordial granules appear in the interphase of the myeloblast, respectively in the early promyelocytes. The first granules in the neutrophils are pale, of homogeneous structure. These granules grow gradually denser with increasing condensation. In the myelocyte stage polymorphism is more pronounced. In the granulocytes, vacuoles and dense-cored vacuoles indicate the sites of granules. In the eosinophil line, the basophilic bodies decrease in number during differentiation. The eosinophil granules show fewer variations in the course of maturation than the neutrophils. The immature forms of the basophil granules are relatively large, pale, and of globular structure; they undergo condensation and show gradually higher density.Sites of granulogenesis in the rat are first of all the Golgi apparatus and, possibly, the cisternae in the endoplasmic reticulum. On occasion, bodies in a transitional stage between a mitochondrium and a granule can be observed, but whether they may have a bearing on the problem of granulogenesis is an open question.     

Nuclear activity during oogenesis in sea urchins

Summary Early meiotic stages of Arbacia punctulata oocytes have revealed the presence of synaptinemal complexes in the chromosomes, which persist through zygotene-pachytene. The synaptinemal complexes conform broadly to the usual tripartite structures found in other higher forms. In addition, nuclei at these stages consist of a small nucleolus and dense bodies of varying sizes. The nucleolus is fibrillar in texture throughout and does not seem to incorporate Uridine-5-³H after pulse labeling, whereas the chromosomes are labeled. The nucleolar label is visualized at diplotene stages and onwards. The nuclear envelope differentiates by the appearance of numerous nuclear pore complexes with dense material in the annuli, and the chromosomes become markedly diffused. At vitellogenesis stage the nucleolus and chromatin become highly labeled after pulse incorporation of Uridine, indicating synthesis of ribosomal and chromosomal RNAs.This investigation was supported by grants No. A-5049, A-3624 and D-17 from National Research Council, Canada, grant No. DRB-9340-05 (U6) from Defense Research Board, Canada, and grant No. DRG-918 AT from Damon Runyon Memorial Fund for Cancer Research.     

A differential molecualr topography of the Pr and Pfr forms of native oat phytochrome as probed by fluoresence quenching

Tryptophan (Trp) surface topography of the red- and far-red-absorbing forms of phytochrome (Pr, Pfr) ofAvena sativa L. has been investigated by analyzing quenching of the two components of Trp fluorescence decay, in order to understand the differences in the two forms at the molecular level. Stern-Volmer kinetic analysis of the quenching data for two cationic surface quenchers, Cs⁺ and Tl⁺, showed strong quenching of the short component of the Pr fluorescence (Stern-Volmer constants,K _sv , 27.2 and 21.4 M⁻¹, respectively) relative to that of Pfr fluorescenceK _sv , 10.4 and 12.3 M⁻¹, respectively). The long component of the Trp fluorescence was quenched differentially by Cs⁺ and Tl⁺, withK _sv of 9.0 and 19.8 M⁻¹, respectively, for the Pr fluorescence andK _sv of 13.7 and 8.7 M⁻¹, respectively, for the Pfr fluorescence. The results indicate that the phytochrome Trp residues with short fluorescence lifetime are more accessible to the cationic surface quenchers than those with long fluorescence lifetime. The data, taken together with our earlier study (Singh et al. 1988, Biochim, Biophys. Acta936, 395–405), indicate that most, if not all the ten Trp residues of phytochrome, are fluorescent and exist in distinct groups differing in their topography and microenvironment, and the peptide segment containing Trp-774 and Trp-778 within the 55-kilodalton C-terminal domain of phytochrome also undergoes a subtle alteration in its surface topography during Pr→Pfr phototransformation. This paper is dedicated to Professor Hans Mohr in commemoration of his 60th birthday     

Comparative morphology of the stomach of some laboratory mammals

Histomorphology of the stomach of mouse, rat, hamster, guineapig, gerbil, and rabbit was studied. Although a common structural basis existed in the stomach between these species, the occurrence and distribution of various cells in gastric glands differed considerably between them. In mice, rats, hamsters and gerbils, the lower one-third of the glandular lamina propria was seemingly occupied by a varying proportion of parietal and chief cells. In rabbits, the predominantly occurring chief cells were distributed in the lower three-quarters of the glands intermingling with parietal cells, but in guinea-pigs the chief cells were not discernible. In hamsters, there was, however, a gradual increase of chief cells from the junction between nonglandular-glandular stomach toward the pyloric region. In all these species, parietal cells were the predominant cell type in the upper half to upper one-third of the gastric glands, often extending up to the neck of the glands interspersing between mucus neck cells and occasionally between chief cells.     

The frequency of mutations in exon 11 of the CF gene in Polish cystic fibrosis patients.

Results of mutation analysis in exon 11 of the CF gene have been presented. Using the SSCP technique 18 mutations (of four different types) were detected in cystic fibrosis patients of Polish origin. Thus, we were able to detect in exon 11 about 10% of all CF mutations occurring in the affected population examined.     

Environmental influences on the sensitization by drugs measured in peripheral blood lymphocyte chromatin

An "allergo-kinetic" method was introduced, which measures early changes of nuclear chromatin structure of lymphocyte subpopulations. The method is used as an in vitro test for drug allergy. The comparison of data from two sampling places (Budapest-Esztergom) shows the following results: The drug allergy scores (obtained from T-cells) may reflect environmental influences on the population under study. During the 13 months period after Atomic Reactor accident in Chernobyl, both the frequency of severe skin manifestations and that of organ manifestations (without skin lesions) increased. The ratio of negative test results decreased in both of drug allergic patient groups (small town = Esztergom, large city = Budapest)--tendency to polysensibilization. The scores obtained in drug related groups of generalized urticaria and Quincke's oedema increased significantly within 13 months after accident followed by a normalization in the subsequent year.