SEARCH · PubMed Health

Results for “MICRO-ORGANISMS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

PubMed1979

Irgasan-induced pigmentation in Serratia marcescens and Pseudomonas aeruginosa.

Two irgasan-resistant micro-organisms (P. aeruginosa and S. marcescens) were used to study the effects of various antibiotic and chemotherapeutic agents on pigment production. These agents included streptomycin, thallium acetate, polymyxin B, hexachlorophene, irgasan, prodigiosin and DMSO (dimethyl sulphoxide). Only irgasan, compared to other drugs and membrane-active agents showed the unique property of inducing pigmentation in both P. aeruginosa and S. marcescens, i.e. prodigiosin in S. marcescens and pyocyanin in P. aeruginosa.

Dose-Response Relationship, Drug↗

PubMed1979

[Suitability of chemical neutralizers applied for disinfection control on commercial animal husbandry objects].

A study on the effect of various neutralizers of the most widely spread means of disinfection applied in animal rearing was made. For that purpose twin lecytine was tested for quadruple ammonium compounds: twin--for phenolic compounds, natrium thiosulfate--for iodoformium and chlor-containing compounds, as well as natrium sulfite--for formalin. As test micro-organisms were used Staph. aureus Sg 511, E. coli 078, and Ps. aeruginosa. The investigations were performed after the suspension method with dilutions in geometrical progressions. It was established that for the disinfection by quadruple ammonium compounds 3% twin-80 plus 0.3% lecytine is suitable as neutralizer. In disinfection with phenolic compounds the 1% twin-80 solution gives good results. As neutralizer of formalin disinfection 2% natrium sulfite solution can be successfully used. For iodoformium disinfection or disinfection with chlor-containing compounds good neutralizing effect can be achieved by 1% solution of natrium thiosulfate.

Animal Husbandry↗

PubMedDate not supplied

[Effect of growth medium composition of glucoamylase and glycosyltransferase activity of Endomyces fibuliger].

Production of glucoamylase and glycosyltransferase by Endomyces fibuliger was found to depend on sources of carbon and nitrogen nutrition. Starch at a concentration above 0.5% in the medium stimulated biosynthesis of glycosyltransferase but inhibited production of glucoamylase by End. fibuliger 20-9. The rate of growth of the micro-organism increased by a factor of 3.3 with an increase of starch concentration from 0.5 to 6%. Synthesis of glycosyltransferase was repressed by glucose, lactose, sucrose and maltose. Synthesis of glucoamylase was repressed by lactose, sorbose and galactose. Synthesis of glycosyltransferase was stimulated by xylose, sorbose and galactose. Production of glucoamylase was stimulated by xylose and arabinose. Growth of the culture and synthesis of glucoamylase and maltase in the cultural broth were stimulated by an increase in the concentration of maize extract. Biosynthesis of glucoamylase and glycosyltransferase was stimulated by NH4H2PO4.

Ascomycota↗

PubMed1975

[Survey of the sensitivity of the strains Neisseria gonorrhoeae to antibioticas in the CSSR during 1957-1973 (authors transl)].

Although the preponderant majority of gonococcal strains is belonging to the most susceptible micro-organisms in respect of the action of antibiotics, certain variations of sensitivity which might be of importance not only for the genetics of microbes, but also for biochemistry and, above all, for therapy may occur also among them, perhaps as a consequence of along-time pressure by antibiotics. In a preceding study (J. Hyg. Epidem. Microb. Immunol. (Prague) 12,296, 1968), the authors analyzed the situation in Czechoslovakia from 1957 to 1967 by means of 911 strains of N. gonorrhoeae isolated from male patients suffering from gonorrhoea. It was also pointed out that there was a certain tendency towards reduced efficacy of penicillin G and a presence of streptomycin-resistant strains. In later years, the studies were extended to include also strains isolated from female patients and sensitivity to some more modern antibiotics was tested. In the present report, a survey is given of the state of antibiotics resistance among gonococci in Czechoslovakia in a chronological order of 17 years which is intended to serve as a basic information for those who are dealing with this subject.

Ampicillin↗

PubMed1977

Leukocyte phagocytic function and dysfunction.

Although some species of bacteria are killed in vitro by humoral factors in cell-free serum, the in vivo experience with leukopenic patients illustrates the critical role played by phagocytic leukocytes in host resistance to infection. Effective ingestion and killing of micro-organisms requires the sequential and integrated function of the elements of the phagocytic system. Each step in the phagocytic process is also a potential crack in the armor of host defense, and an increasing number of clinically significant disorders of phagocytic function are being recognized and described (5). The phagocytic leukocytes are equipped with a variety of intracellular microbicidal mechanisms which provide a degree of overkill capacity and allow these cells to meet the challenges posed by the many and varied microbial transfressors. Undoubtedly, other phagocytic disorders will be discovered and other important aspects of the intraleukocyte killing mechanisms will be elucidated. For instance, little is known about the function of leukocytes within the relatively hypoxic environment of injured tissue where so many bacterial infections begin. As our understanding of phagocytic function develops, new ways may be found to augment host resistance by preservation or stimulation of the phagocytes.

Animals↗

PubMed1976

[Synovial fluid. Review of international literature from 1972 to 1975 (author's transl)].

The tremendous increase in the number of articles from the world scientific literature dealing with the synovial fluid in recent years, reflects the growing interest of research on that subject. The current review summarizes the scientific works published during the period of 1972 to 1975. This review deals with fundamental as well as applied research or clinical reports adding some diagnostic hints in the knowledge of diseases involving joints. The content of the review is divided in two major chapters. 1) The Physico-Chemical Properties of the Synovial Fluid (viscosity, pH,...); 2) The Composition of the Synovial Fluid (proteins, carbohydrates, lipids, prostaglandins, cells, crystals, micro-organisms).

Antibodies, Antinuclear↗

PubMed1978

The breeding and use of specific pathogen-free (SPF) rats.

Bronchiectasis is common in older rats and is a serious complication when the lungs are repuired for research purposes. SPF rats do not develop this complication, but special isolated accommodation must be provided and care of the animals must avoid introduction of outside micro-organisms. Animals removed from the isolated accommodation for experimental work are not returned, but can be kept in the general animal house provided there are no conventionally-bred rats.

Animal Husbandry↗

PubMed1975

[Isolation of "Neisseria elongata" and "Moraxella urethralis" (author's transl)].

A strain of Neisseria elongata and a strain of Moraxella urethralis have been recently isolated from pathological material in the course of a systematic search for rodshaped oxidase positive and Gram negative micro-organisms. The morphological, cultural and biochemical characters of these fewly known strains of which pathogenicity is not clearly defined, are reported in the present paper together with some comments.

Acetates↗

PubMed1976

[Anatomo-clinical and experimental studies on pneumocystis carinii. Preliminary note].

The authors have been interested over the last year in the detection of pneumocystis carinii in patients with immune deficiencies, whether natural or artificial. After a brief historical and general introduction, they discuss their procedures, the pathological substances available, the staining techniques and the examination of autopsy specimens. They undertook experimental work on this micro-organism, e.g. the development of the germ in immuno-depressed rats and, from this material, numerous varied trials of culture and inoculation in new-born animals, chick embryos and cell cultures. Microphotographs illustrate this work which is still in progress.

Animals↗

PubMedDate not supplied

Clinical and virological findings in patients with cytologically diagnosed gynecologic herpes simplex infections.

Amoung 57,117 routinely collected Papanicolaou smears from the female genital tract there were 90 slides (0.16%) from 85 patients on which a cytologic diagnosis of herpes simplex virus (HSV) infection was made. The characteristic cytologic changes occurred predominantly on the ectocervical part of the smears. The changes were transient but occasionally remained detectable on the corresponding histologic specimens up to 2.5 months. Viral isolation was successful in a majority of cases when performed simultaneously with or less than a week after the cytologic diagnosis. The rate of success rapidly decreased thereafter. Positive fluorescent antibody assays of viral antigens on cytologic smears behaved similarly. Cases with apparent primary infection as well as with secondary infection (recurrences) were included in the material but no differences in the morphology of virally altered cells and be found, indicating that primary and secondary infections could not be distinguished on this basis. There were significantly more cytologic dysplastic changes as well as assorted micro-organism infections in the HSV group as compared to the controls.

Adolescent↗

PubMed1977

[Pz peptidase activity in serum (author's transl)].

Synthetic PZ peptide, synthesized by Wünsch and Heidrich, was used as substrate to determine PZ peptidase activities in the sera of man, rabbit, guinea pig and mouse. The PZ peptidase from rabbit serum was purified 200 fold and characterized. The enzyme has an isoelectric point of 5.0 and pH optima at pH 7.2 and pH 7.9. Its behaviour on gel filtration points to a molecular weight of 60.000 dalton. The peptidase is inhibited by heavy metal ions, SH reagents and serum. Ca ions are EDTA are without any effect. In contrast to collagen peptidases from micro-organisms, the enzyme from rabbit serum does not attack native, but only denatured collagen. The results suggest that PZ peptidases participate in collagen breakdown by cleaving the collagen fragments which are released by the collagenases.

Adult↗

PubMed1978

Cell composition and drug resistance in Escherichia coli.

Resistance of micro-organisms to antibacterial drugs which cannot be attributed to a genetic change may often be traced to phenotypic changes in cell composition caused by differing growth conditions. To investigate an aspect of this attribute E. coli NCTC 86 was grown on a simple synthetic media containing alanine or cystine and, as a control, in nutrient broth. Cells grown on the media containing alanine and cystine showed a depleted total extractable lipid and phospholipid content. Phosphatidylethanolamine was notably reduced in both cases. Electrophoretic studies revealed a reduction in the surface lipid of cells grown on the simple synthetic media, while electron microscopy revealed defects in the cell wall of the cells grown on alanine. The total protein content of cells grown on alanine was reduced, whereas cells grown on the cystine showed an enhanced total carbohydrate content. Lipopolysaccharide synthesis was possibly also affected as judged by 2-keto-3-desoxy-D-manno-octonic aid content. The action of p-tertiary amylphenol, cetrimide and polymyxin B sulphate, showed that cells grown on the media containing alanine were most susceptible to the action of the phenol and cetrimide, whilst cells grown on the media containing cystine were most resistant to the action of polymyxin.

Bacterial Proteins↗

PubMed1979

[Pathology of the polymorphonuclears in dermatology. Methods of investigation. Clinical pictures (author's transl)].

A remarkable increase in the number of recognized clinical abnormalities of neutrophil function has occurred within the 8 years past. Of major importance in the delineation of these disorders is the establishment of appropriate methodology of their characterization. This review discusses phagocytosis and its disorders by dividing it into stages that encompass the way in which phagocytes ferret out injection, how they recognize pathogens and the intracellular events leading to engulfment and killing of micro-organisms. The pathology of chemotaxis and random mobility is described: the lazy leukocyte syndrome, the Chediak-Higashi syndrome, the familial chemotaxis pecular dermatosis, and a variety of serum abnormalities of the serum complement system associated with deficient generation of chemotactic activity. The second part of these disorders is dailing with the inherited abnormalities of the oxygen dependent killing mechanisms of phagocytes, the chronic granulomatous disease, the glucose-6-phosphate deshydrogenase deficiency, the myeloperoxydase deficiency and the glutathione peroxydase deficiency.

Adolescent↗

PubMed1975

[Glass fibre HEPA filters. II. Communication: Microbiological and physico-chemical researchs on used and unusued, hydrophilic and hydrophobic filter materials in an air conditioning plant (author's transl)].

Hydrophobic and hydrophilic, used and unused HEPA filters from various manufacturers, inoculated with vegetative bacteria, bacterial and fungal spores, were exposed to clean outside air for up to 17 weeks in an air conditioning plant. With relative humidities up to 60%, an increase in germ count could not be found. The rate of killing the micro-organisms inoculated were different and were generally higher on used filters. The low water content of the filter material was apparently not sufficient for microbial growth. In addition, the increase in electric conductivity and reduction of pH value resulting from deposition of substances from the outside air with an acid reaction ascertained in the aqueous filter extracts had a negative effect on the living conditions of the microorganisms.

Air Conditioning↗

PubMedDate not supplied

[Problem of "biological compatibility" of crew members during prolonged space flight and possible directions for its solution].

The concept of biological compatibility of men can be defined as a phenomenon which includes an effect (that might be favorable or unfavorable) of one individuum on the other via trace amounts of chemicals released into their environment and micro-organisms. The paper presents the main results of studies of biological compatibility of crewmembers of space vehicles and outlines possible directions of research to be carried out in this area.

Bacteria↗

PubMed1976

Mycoplasma in tissue culture: overview of detection methods.

Mycoplasma contamination of tissue cultures is too costly, scientifically damaging and inappropriate, and perhaps, even medically hazardous to be ignored. Prevention by continuous surveillance demands adequate mycoplasma testing procedures. Despite a proliferation of indirect methods, the present consensus indicates that careful and extensive microbiological testing is still the cornerstone of any mycoplasma detection program. The finding of 'non-cultivable' or possible tissue-adapted micro-organisms plus the variability in microbiological expertise of many laboratories, makes the selection of at least one additional method imperative. At the present, though no one test will prove 100% satisfactory and selection should partly depend on available expertise, the method based on the ratio of the specific activities of incorporated radio-labelled uridine to uracil into RNA appears to be an acceptable choice due to its simplicity and general validity.

Bacteriological Techniques↗

PubMed1977

Microbial secondary metabolites with potential use in cancer treatment. (Plasmid involvement in biosynthesis and compounds.

Antibiotics and small molecular enzyme inhibitors produced by micro-organisms are microbial secondary metabolites which have no obvious function in the growth of microorganisms. Involvement of plasmids in their biosyntheses has been studied and the structure of the microbial world where various compounds with widely varying structures have been found has been shown to be due to the presence of a great variety of plasmids. On the basis of this structure of microbial world, the author has found the microbial products which have various activities useful in treatment of cancer or in suppression of carcinogenesis. In this paper, the author reviewed his following studies: the plasmid involvement in biosyntheses of bioactive microbial secondary metabolites; the mechanism of therapeutic effect of bleomycin, and the development of useful analogs and derivatives of bleomycin and anthracyclic antibiotics; the screening method to find compounds affecting immune system, and the action of bestatin in enhancing delayed-type hypersensitivity and therapeutic effects of anticancer agents; enzyme inhibitors with potential utility in treatment or prevention of cancer.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed1979

[Immunotherapy of malignant growths (author's transl)].

Our knowledge of antigens which are associated with different types of malignant tumours is steadily increasing. These antigens exist in considerable numbers, but, so far with few exceptions, only their presence can be demonstrated by certain methods; to isolate and identify them has not yet been possible. These antigens are, therefore, suitable not so much for the primary diagnosis, but rather, like the carcinoembryonic antigen, the tissue-polypeptide antigen or the alpha-feto-protein, for assessing the success of treatment. Active immunization has recently received a fresh impulse by the use of the enzyme neuraminidase, derived from Vibrio cholerae, in the treatment of tumour cells. There is no passive specific immunotherapy in human cancer. As to specific active immunotherapy BCG, Corynebacterium parvum and preparations of these and other micro-organisms together with polynucleotides, levamisol, statolon, tilorone have been employed. Although the results are not uniform they are promising. Attempts at cellular transfer of immunity are not very encouraging. It should be emphasized that the findings apply to human cancer. Experimental studies have produced very interesting results.

Animals↗