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Biomedical subjects

E Unger

Publications and source records attributed to E Unger.

At least 145 records · Page 8Linked to original sources
PubMed1980

Modification of toxicity of violamycin BI (VBI) by complex formation with DNA, metal ions, and by pretreatment with alpha-tocopherol.

In connection with studies on lowering the toxicity of violamycin BI (VBI) the intravenous (i.v.) LD50 values were determined in mice for VBI, VBI complexed with DNA, Fe3+ or Pt2+, and after pretreatment with alpha-tocopherol. The results indicate that the toxicity of VBI is reduced by complex formation with DNA or ferric ions including a partial decrease of the antimicrobial and antiviral activity.

Aminoglycosides↗
PubMed1980

Histological effects of low-dose-rate gamma-irradiation. 1. Observations in rats after 1000 rd total-dose irradiation.

Concerning the effect of 1000 rd low-dose-rate (0.64 to 0.73 rd/min) gamma-irradiation generally a lesser degree of histological damage is observed in radiosensitive rat organs 7 days after irradiation than after the same dose of acute irradiation at the same interval. The evaluation of experimental results indicated that the cause of this phenomenon mainly is not reduced cell damage but the early initation of the regeneration and its accelerated rate as against the acute irradiation.

Animals↗
PubMed1980

Histological effects of low dose-rate gamma-irradiation. II. Observations in rats after 400 rad total-dose irradiation.

Several days after 400 rad low (0.59 to 0.63 rad/min) dose-rate gamma-irradiation, minor histological injuries are observed in some of the radiosensitive organs of rats in contrast to the same dose of acute irradiation after the same interval. The earlier initiation and the more accelerated pace of regeneration, as against acute irradiation, are playing a role in the less severity of injuries, though its significance is not so unequivocal as at higher radiation doses.

Animals↗
PubMed1980

Histological effects of low-dose-rate gamma irradiation. III. Electron-microscopic observations in rat spleen.

As an effect of 400 and 1000 rd low (0.59 to 0.73 rd/min) and high (60 to 78 rd/min) dose-rate gamma irradiation an expressive accumulation of autophagous vacuoles can be observed in electron-microscopic sections of rat spleen. The number of autophagous vacuoles seemed higher in the group exposed to lower dose-rate of irradiation. This observation is in agreement with the results of the former experiments which indicated that after low-dose-rate irradiation the damaged cells show an increased tendency to repair.

Animals↗
PubMed1979

Ultracytochemical characterization of non-specific acid phosphatase activities in Saccharomyces cerevisiae.

Glutaraldehyde prefixation causes a considerable inactivation of the acid phosphatase of yeast protoplasts in dependence on the duration of aldehyde influence. Lead ions necessary for ultracytochemical demonstration effect a still stronger inhibition of enzymatic activity. Prefixation, however, protects the enzyme from further inhibition by lead. At pH 4.4 in intact cells acid phosphatase activities are mainly localized in the periplasmic space and in vesicles fused with the plasma membrane. The cell wall and cytoplasm usually remain free of reaction products. On the cell surface activities are found in form of globular lead deposits. At pH 5.2 and 6.3 the periplasmic activity appears decreased compared to that at lower pH values and the intracellular activity is increased. The plasma membrane of protoplasts is completely free of precipitates. The intracellular activity sites of protoplasts (cisternae of endoplasmic reticulum and/or Golgi-like system, small vesicles, central vacuole, nuclear envelope) are the same as for intact cells. The occurrence of at least two forms of acid phosphatase in S. cerevisiae id deduced.

Acid Phosphatase↗
PubMed1978

In vitro induction of cell-mediated immunity to murine leukemia cells. III. Effect of methanol extraction residue fraction of BCG on the generation of cytotoxic lymphocytes against leukemia.

Effects of the methanol extraction residue (MER) fraction of tubercle bacilli (BCG) on the generation of cytotoxic lymphoid cells were studied in vitro with the use of unidirectional mixed lymphocyte-tumor cell cultures. These cultures consisted of splenocytes of lymph node cells from normal donor C57BL/6, BALB/c, and strain A mice and mitomycin C-inactivated leukemia cells of both syngeneic and allogeneic origin. Addition of small amounts of MER (0.2-5 microgram/ml) to the cultures potentiated appreciably the elicitation of cytotoxic reactivity (as measured by the 51Cr-release assay) of the sensitized cells, whereas higher quantities (10-40 microgram/ml) had a strong suppressive effect. MER also induced some cytotoxic capacity in normal murine and human lymphoid cells not exposed to specific tumor cell stimulation. The stimulatory and suppressive effects were noted only when MER was present during the initial 24-48 hours of the 6-day culture. With the nylon wool fractionation technique, it was apparent that MER affected primarily the nonadherent cell population. MER could also prevent the generation of nonspecific suppressor cells by splenocytes maintained for 3-6 days in tissue culture.

Animals↗
PubMed1978

Migratory traumatic cardiovascular foreign bodies.

Six cases of cardiovascular foreign bodies secondary to trauma are presented. The various modes of entry and travel within the vascular are reviewed. Routine radiographic examination and angiography are shown to be the most useful techniques in defining the location and subsequent course of the foreign body in the vascular system.

Adult↗
PubMed1978

[Accumulation of phosphate ions in biological materials, phosphate ion diffusion and electron microscopical investigations of phosphohydrolases (author's transl)].

Isolated unfixed nuclei of mouse liver accumulate different amounts of phosphate ions dependent on pH, temperature and concentration of phosphate ions. At 37 degrees C and pH = 7.2, 8.5 X 10(9) binding places and a stability constant of 2.0 +/- 0,5 . 10(4) l/mol were calculated, the data at 30 degrees C and pH = 6.5 are 4 X 10(9) Nucleus-1 and 6 X 10(3) l/mol. Nuclei fixed by formaldehyde-ethanol or glutaraldehyde do not accumulated phosphate ions. Under conditions of nearly undisturbed diffusion phosphate ions taken up by the nuclei and precipitated by the help of lead ions are detected electron microscopically in the nuclear envelope, preferently in intracisternal space. Nucleoprotein structures do not show enrichments of crystals. These structures are also not stained after precipitation of phosphate ions under conditions of diminuation of diffusion. A possible mode of phosphate binding in cell nuclei and the influence of adsorbed phosphate ions on localization of enzymatic activities are discussed.

Animals↗
PubMed1978

[Essay of proteins after aldehyde treatment in biological objects (author's transl)].

Following fixation with formalin or glutaraldehyde, the protein content of bovine serum albumin, lysozyme, non-disintegrated yeast cells and liver nuclei of mice is determined by means of a brom-phenol blue staining procedure and the widely used Lowry-technique. The bromphenol blue technique permits determinations of soluble as well as particulate proteins or protein mixtures fixed with up to 6% formalin or 2% glutaraldehyde. Recovery rates differ no more than 20% as related to unfixed controls. Using the bromphenol blue method it is not necessary to separate aldehyde or any interfering material by additional steps prior to determination. Factors for correcting protein content of biological material after aldehyde treatment are available. In this way, comparative biochemical as well as cyto- and histochemical investigations of enzymatic activities after aldehyde fixation are possible. Some advantages of the bromphenol blue technique with special reference to the analysis of particulate and/or aldehyde-fixed specimens are discussed.

Animals↗
PubMed1977

[Concanavalin A-binding to cyclic reassembled microtubules from pig brain-tubulin (author's transl)].

Concanavalin A reacts to cyclic reassembled microtubules. The results were analysed morphometrically and topochemically. Concanavalin A can be observed mainly on the outer part of the microtubules and also partly in the lumen. After Concanavalin A reaction the diameters of microtubules are significantly higher than in the controls. It is shown that the saccharide component does not disappear during cyclic reassembly of microtubules. This compoenent is seen as a glycoprotein and as a part of at least one of their protein fractions or as a constitutive factor of microtubules.

Animals↗
PubMed1976

In vitro induction of cell-mediated immunity to murine leukemia cells. I. Optimization of tissue culture conditions for the generation of cytotoxic lymphocytes.

Cytotoxic lymphocytes (CTL) to allogeneic and syngeneic murine leukemia cells were generated in vitro in "one way" mixed lymphocyte-tumor cell cultures carried out under a variety of conditions. In an attempt to define the optimal culture conditions for sensitization, the following parameters were analyzed: culture vessel, culture volume, responder: stimulator (R:S) cell ratio, lymphoid cell density, source of lymphoid cells, duration of culture, fetal calf serum (FCS) concentration, 2-mercaptoethanol (2-ME) concentration, concentration of amino acids, and buffering system. Of the many variables examined, of particular importance were the R:S cell ratio, the cell density, the FCS concentration, the presence of 2-ME, and the time of harvesting. These factors exerted various effects, both quantitatively and qualitatively, on the magnitude and kinetics of the responses induced in microcultures (5 X 10(6) lymphocytes) and macrocultures (25 X 10(6) lymphocytes). Moreover, optimal sensitization in syngeneic cultures required different conditions than those for allogeneic cultures. Cytotoxic activity was assessed in vitro by a quantitative 51Cr-release assay. The sensitized lymphocytes demonstrated the characteristics ofT lymphocytes and reacted specifically with the sensitizing leukemia cells.

Animals↗