[Electron microscopic observations on the existence of "deflagellation tolerance" processes capable of explaining the selective isolation of vibrios in semisolid agar]. / Observatii electronomicroscopice cu privire la existenta unor procese de "deflagelare-toleranta", capabile sa explice izolarea selectiva a vibrionilor în agar semisolid.

The authors identified a group of substances (flagellar depression factors--FDF) which suppress the mobility of enterobacteria (immobilization) but do not influence the Vibrio movements (tolerance). FDF do not affect the vital processes, multiplication and formation of colonies. Electron microscopic interpretation showed that, in the usual media, enterobacteria have characteristic peritrichous cilia, whereas in media with FDF they are denuded of their flagellation formation. As such a process of flagellation depletion seems to be not known, we suggest the term "deflagellation" to name it. In a completely different way, the vibrios keep their single cilium located apically and implicitly their moving ability. These behaviour differences are evident in semisolid agar with FDF. The deflagellated enterobacteria are, therefore, immobilized, and multiply, forming small punctual colonies, of 0.5-1 mm phi, whereas the vibrios tolerating FDF develop and at the same time move in the liquid agar, mass, forming large colonies, of 8-14 mm phi. The electron microscopic observations presented show the existence of a "deflagellation tolerance" process and also explain the specific typology of the colonies of vibrios and enterobacteria formed in liquid agar with FDF.

HBsAg positive secondary autoimmune active chronic hepatitis. Immunogenetic aspects.

Observations were made in a group of 120 patients with active chronic hepatitis (ACH), using demonstration of HBsAg presence, structural study of the peripheral blood mononuclear cell population by means of scanning electron microscopy (SEM) and typing of HLA-A, B and C antigens. From the whole group 22 patients were proved to have an autoimmune form of ACH secondary to infection with hepatitis B virus (HBV). The authors consider that the diagnostic value of the ratio between B and T lymphocytes (studied by SEM) is relative but the demonstration of an increased percentage of monocytomacrophage cells and the presence of "killing phenomenon" clearly reflect a more severe hepatic inflammation. A higher incidence of the HLA-Bw35-Cw4 was observed particularly in the HBsAg positive forms of ACH and in the HBsAg positive secondary autoimmune forms. The authors discuss the utility of these observations when the opportunity of corticotherapy has to be established.

Animal DNA viruses analyzed by colour electron microscopy.

Black-and-white and colour transmission electron micrographs of three DNA viruses (infectious bovine rhinotracheitis virus, bovine adenovirus type 5 and Molluscum contagiosum) are comparatively presented. The colour images have been obtained by an original method of computer-assisted analogic processing of black-and-white micrographs, using the Romanian electronic device OPTIMISCOP. A comparative analysis of the two types of images demonstrates the variety of additional information provided by the new processing technique.

Changes concerning the external structure of peritoneal macrophages, due to the DQ-12 standard dust.

The cytotoxic activity of the DQ-12 standard dust on the external structure of peritoneal macrophages, after intraperitoneal introduction, was investigated, vs nontreated macrophages, and kept in in vitro cultures for 3, 6, and 24 hr. The alterations related to the external structure were investigated by scanning electron microscopy (SEM), clearly showing that cell damage can take place when the dust contacts the external surface of the cell, as already shown by the work of Johnson and Davies (paper presented at the International Workshop on the in Vitro Effects of Mineral Dusts, South Wales, U.K., 1979) and Miller (Environ. Res. 20, 162-182, 1979).

Relationship between the lead concentration in hair and occupational exposure.

The lead content of hair in workers occupationally exposed was correlated with the blood lead concentration. Determinations of lead in blood and hair were performed by electrothermal atomic absorption spectrophotometry in two exposed groups and a control group. A significant correlation was observed between the blood lead and hair lead concentrations, and a regression analysis showed an exponential accumulation of the lead content in hair, simultaneously with the increase of the values in blood. The colour of the hair and the age of the subject did not influence the lead accumulation in hair in the occupationally exposed subjects. The assessment of lead in hair is considered a useful screening test in estimating occupational exposure.

Changes of human platelets studied by scanning electron microscopy in acute myocardial infarction.

The formation of platelet aggregates has been suggested to be the initial step in coronary occlusion and the subsequent myocardial infarction (AMI). By scanning electron microscopy we followed: the platelet morphology and aggregation, the macrophage (M) morphology and the lymphocyte (T, B) count and structure in 11 patients with AMI and in 18 patients with unstable angina (UA). Generally, in the patients with AMI, most of the platelets presented relatively frequent (42.5%) or very frequent pseudopodia (35.27%) and the network of surface extensions was associated with several huge platelet aggregates in 6 patients. The mean lymphocyte count was: T = 40.36 +/- 23.95%; B = 28.09 +/- 7.38%; M = 31.54 +/- 21.25%. In the patients with unstable angina the proportion of platelets with pseudopodia was more reduced, namely, that of platelets with relatively frequent pseudopodia was 33.8% and with very frequent pseudopodia was 27.8%. The mean lymphocyte count was: T = 40.30 +/- 20.24%; B = 34.6 +/- 14.39%; M = 25 +/- 10.50%. These data indicate that platelet changes and the formation of aggregates can be an important factor in the occurrence of AMI. The change of immunocompetent cell count in both groups of coronary patients suggests the association of an immunologic process in coronary atherosclerosis.

"Killer"-type phenomena in the immune pathology of some chronic internal diseases. (Scanning electron microscopy studies).

Aspects of cytotoxicity followed by cytolysis have been described by many authors in neoplasias. Using scanning electron microscopy, the authors have investigated the cellular population from 179 patients with various chronic internal diseases such as: chronic hepatitis, diabetes mellitus, systemic lupus erythematosus, scleroderma, chronic lymphocytic leukemia. In some of the forms of disease with severe clinical and biological phenomena, they have detected the presence of "killer" type phenomena, having as target cells either the monocytomacrophage or the T or B lymphocytes. Iconographic aspects are demonstrating the presence of this phenomenon, observed particularly in the peripheral blood. Detection of such phenomena is assumed to provide information on prognosis of the chronic disease investigated and on the effects of therapy at cellular level.

Some ultrastructural aspect of T and B lymphocytes and their significance in chronic internal diseases with immune component.

Some peculiar aspects of T and B lymphocytes from patients with chronic internal diseases with immune component such as: chronic hepatitis (CH), rheumatoid arthritis (RA), diabetes mellitus (DM), systemic lupus erythematosus (SLE), chronic lymphocytic leukemia (CLL) and others, could be detected using transmission electron microscopy (TEM) or scanning electron microscopy (SEM) in association with cytomorphologic, cytoenzymochemical and/or cytoimmunologic methods. Among the more frequent aspects observed were the change of the T and B lymphocyte balance and the presence of giant nucleoli associated with RNA hyposynthesis. This latter aspect was proved to be a sign of unfavourable prognosis and of resistance to immunosuppressive treatments in diseases such as: RA, SLE and CLL.

Electron optic investigations on influenza virus A(H1N1) interacted with some aromatic compounds.

The morphological changes caused by the interaction of influenza virus A(H1N1) with three fluorescent aromatic compounds (a vinyl-sulfonic and an isocyano naphthalic acid derivative and the 4-acetylamino-naphthalene-1,8-dicarboxylic acid) were studied in the electron microscope. The intensity and type of the alterations depend on the chemical structure of the compounds and can be correlated with their effect on the biological activities of influenza virus.

[Isolation of a Pasteurella multocida bacteriophage]. / Isolierung eines Pasteurella-multocida-Bakteriophagen.

Lysogenesis testing of 84 Pasteurella multocida strains resulted in detection of one lysogenic strain from which phage B225 was isolated. B225 lysed only one Pasteurella multocida strain isolated from cattle. The Pasteurella phage, when examined by electron microscopy, showed a hexagonal head and a non-contractile, Flexible tail, It could be attached, consequently, to Group B according to Bradley (1967).

Propagation of equine infectious anemia virus in horse cell cultures.

The Wyoming strain of equine infectious anemia virus was adapted to cell cultures by 7 passages in horse leukocytes and 14 passages in fetal equine dermal and kidney cells. The virus was made evident by electron microscopy and immunodiffusion tests with antigens prepared from culture fluids.

Aspects of the T and B lymphocyte surface architecture in chronic internal diseases with immune component. Scanning electron microscopy studies.

Investigations on the T and B lymphocyte surface architecture were carried out by means of scanning electron microscopy (SEM) in 102 patients with various chronic internal diseases such as chronic hepatitis, diabetes mellitus, systemic lupus erythematosus, chronic lymphocytic leukemia, a.o. The clinical and biological examination performed in these cases reveled also some cytochemical, biochemical and immune disturbances. Emphasis is laid on the superiority of SEM, as compared with the E and EAC rosette tests, for the identification of T and B lymphocytes. Moreover, by detecting certain cellular anomalies, SEM can provide useful indications regarding the diagnosis, prognosis and therapy of the above mentioned diseases. Association of SEM with other clinical and laboratory investigations can either confirm, disapprove or even enhance the value of the morphological findings by electron microscopy.

Examination of human and animal leukemic cells by high contrast scanning electron microscopy.

Investigation of human or animal (sheep and ox) leukemic cells by scanning electron microscopy enabled the identification and study of some ultrastructural details of the cell surface. A more detailed visualization by the high contrast technique of the same cell surface was obtained, in this work, for the first time in the biological field. This technique allows a better interpretation of any zone of the preparation examined, irrespective of the species from which the cells are collected.

Identification and study of the various leukocytes, particularly of the leukemic ones. (Principles and some technical details).

Based on the main data from the specialty literature and on their own experience in the field, the authors present the principles and some details of the classical and the modern techniques used to identify and study the various leukocytes and especially the leukemic ones. These different methods of investigation are included into the wide categories of histologic, cytomorphologic, cytochemical, cytoenzymatic, cytoimmunological, cytogenetic, cell culture and other complementary techniques. The great progress achieved in this domain was favoured by the development of light, contrast phase and fluorescent microscopy and of the new techniques of transmission and scanning electron microscopy--whose utility for the study of the white blood cells, and particularly of the leukemic ones, is demonstrated in this paper by numerous suggestive illustrations.