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B Neumann

Publications and source records attributed to B Neumann.

At least 19 recordsLinked to original sources
PubMed1992

Size and stability of the genomes of the myxobacteria Stigmatella aurantiaca and Stigmatella erecta.

Genomic DNA of Stigmatella aurantiaca DW 4/3.1 was restricted with the rare-cutting endonucleases AseI and SpeI. The restriction pattern derived is composed of 33 AseI and 25 SpeI fragments, whose total size amounts to approximately 9,350 kbp. Genomic fingerprint analysis of chromosomal DNA from several S. aurantiaca isolates further revealed five completely different SpeI and AseI fingerprints and one distinct fingerprint for Stigmatella erecta. In addition, minor variations between the genome sizes of these isolates were observed.

Chromosome Mapping↗
PubMed1991

Immunoblot for densitometric estimation of antibodies (IDEA): a useful method for quantification of intrathecally produced antibodies against individual antigens in infectious diseases of the central nervous system.

Intrathecally produced antibodies specific for the infectious agent can be shown by immunoblot. A quantification is practicable by titration. Densitometric evaluation of the immunoblot by a new technique, IDEA (immunoblot for densitometric estimation of antibodies), does not only render titration unnecessary, but also has the advantage of presenting the differentiated local immune response against individual antigens of the infectious agent. Preliminary studies for the densitometric evaluation were performed with a measles virus immunoblot which had been developed with a cerebrospinal fluid (CSF) sample of a patient suffering from multiple sclerosis containing high antibody titers. A peroxidase-labeled anti-immunoglobulin antibody had been added. The intensity of the color reaction on the membrane dependent on the antibody concentration follows a saturation kinetics comparable to the Michaelis-Menten kinetics in enzymology. Thus, indices for the intrathecal antibody synthesis of each individual viral antigen can be calculated by taking the permeability of the blood-CSF barrier into consideration. This method is illustrated in a patient with zoster meningoencephalitis.

Antibodies, Viral↗
PubMed1991

Second generation biosensors.

Enzyme-membrane electrodes using glucose oxidase in combination with peroxide detection dominate in the field of laboratory analyzers for diluted samples. Using the same indication principle, extremely fast responding glucose sensors have been fabricated by covering thin metal electrodes with a porous enzyme layer. In the second generation auxiliary enzymes and/or co-reactants are coimmobilized with the analyte converting enzyme in order to improve the analytical quality and to simplify the performance. Following this line oxidizable interferences are suppressed by using a glucose oxidase/peroxidase complex which communicates with the electrode at a low working potential. Furthermore, fluctuations of pH or buffer capacity are ineffective when using a glucose oxidase/peroxidase layer covered fluoride FET in the potentiometric glucose determination. Enzymatic recycling of the analyte and/or accumulation of intermediates increase the sensitivity by several orders of magnitude. Inclusion of NAD bound to PEG in the glucose dehydrogenase layer allows a reagentless glucose measurement.

Biosensing Techniques↗
PubMed1991

Brief treatment for alcohol dependence: level of dependence and treatment outcome.

The relationship between level of alcohol dependence and treatment outcome was examined by comparing the success rates of severely dependent and not severely dependent males treated briefly in Toronto and Brazil. Treatment involved three 1-hour sessions of training in methods for achieving abstinence or moderate drinking. During the year following treatment, the severely dependent clients were more frequently rated as "successful"--56% of them achieved abstinence or moderate drinking, compared to about 30% of those who were not severely dependent. Although this difference is not statistically significant, the finding is clearly of clinical relevance.

Adult↗
PubMed1990

Detection of HIV RNA by in situ hybridization in peripheral blood mononuclear cells of seronegative children born to HIV-infected mothers.

Of 44 children born to human immunodeficiency virus (type 1) (HIV)-infected mothers, 11 have become seronegative. After the loss of maternal antibodies all children were analysed for several immunological functions and virological parameters in order to determine their HIV status. All children to date are clinically healthy and have normal immune functions. HIV-1 was detected by p24 antigen in one child, by in situ hybridization in nine children while viral cultures were all negative. These data suggest that the rate of vertical transmission of HIV-1 may be underestimated if seronegative children are considered to be not infected. They also suggest that molecular biological techniques are more sensitive than HIV antigen assay or viral cultures.

AIDS Serodiagnosis↗
PubMed1990

Fine specificities of antibodies in sera and cerebrospinal fluid in herpes virus infections of the central nervous system as detected by the antigen variable immunoblot technique.

Applying the immunoblot technique a sensitive and specific method was developed for the detection of intrathecally synthesized antibodies against individual specific proteins that are antigens of various infectious agents causing encephalitis. Paired serum and cerebrospinal fluid (CSF) samples from five patients with herpes virus infections of the central nervous system (CNS) (three herpes simplex virus encephalitis, one varicella zoster virus encephalitis, one zoster ganglionitis) were investigated for the presence of locally produced IgG against the electrophoretically separated antigens of herpes simplex virus (HSV), varicella zoster virus (VZV) and human cytomegalovirus (HCMV), as well as for IgM antibodies in one case of HSV encephalitis. In two cases (HSV encephalitis and VZV encephalitis) four and one antibody, respectively, were found that were synthesized intrathecally only. In the other cases the patterns of sera and CSF antibodies were similar, the CSF antibodies showing an all-over stronger reaction, at identical IgG concentrations. In contrast to the conception of a 'limited heterogeneity' of intrathecal antibody synthesis in encephalitis, we thus found an 'expanded heterogeneity' of the intrathecally synthesized antibodies in comparison to the corresponding serum antibodies.

Adult↗
PubMed1990

[Serologic studies in the diagnosis of pneumonia].

The importance of serological determination procedures for the diagnosis of pathogens was investigated in 207 episodes of pneumonia. The pathogenic organisms were detected in 138 cases; in 40 cases serological analysis helped to establish the diagnosis, while in 11 cases of pneumonia, the diagnosis was possible only with serology. The organisms most commonly found by serological investigations were Cytomegalovirus (n = 10), Aspergillus fumigatus (n = 7), and the influenza B virus (n = 7). Multiple infections, usually triggered by bacterial pathogens, were found in 48% of the cases of pneumonia with serological evidence of pathogens. In 71 episodes of pneumonia, the patients were immunosuppressed; in 11 cases, the causative organism was detected serologically.

Adult↗
PubMed1989

Clonal and variable properties of Neisseria meningitidis isolated from cases and carriers during and after an epidemic in The Gambia, West Africa.

A representative collection of meningococci was isolated from cases and healthy carriers in The Gambia between 1982 and 1988, during and after an epidemic of meningococcal meningitis. These bacteria were subjected to a clonal analysis. All serogroup A bacteria from both cases and carriers were of one clone (A IV-1). Several unrelated clones were observed among serogroup 29E and serogroup Y carrier strains. The serogroup A strains were uniform for serotype and subtype antigens (serotype 4, subtype P1.7) and antibiotic sensitivity pattern. Occasional strains varied in their lipopolysaccharide (LPS), DNA fingerprint pattern, and/or the quantitative expression of the class 1 protein. A high degree of strain-specific variation was found for the expression of class 5 proteins, pili, and sulfonamide sensitivity. The frequency of strains expressing reduced amounts of the class 1 protein, altered LPS, and/or increased amounts of capsular polysaccharide rose among case strains obtained after the epidemic had ceased. These strains seem to be generally resistant to antibody-mediated bactericidal activity.

Antibodies, Monoclonal↗
PubMed1989

[Hemostasis monitoring in intensive therapy--studies using resonance thrombography].

The resonance-thrombogram (RTG) is the result of a new investigation method verifying the clotting process as a whole. It provides a far reaching breakdown of the main factors of coagulation and thus a means for diagnosing and treating coagulation disorders. A special field of application is indication and control of therapy in cases of disseminated intravascular clotting and hyperfibrinolysis in intensive care. Simple operation, relatively quick results and the possibility of rapid diagnosis using the RTG curve appear to make it suitable as a bed-side method of investigating blood coagulation.

Blood Coagulation Tests↗
PubMed1988

Cell-cycle-related metabolic and enzymatic events in proliferating rat thymocytes.

Cell-cycle progression of rat thymocytes stimulated with concanavalin A and interleukin 2 was monitored at 12-h intervals by pulse labeling aliquots of the cell culture with [3H]thymidine, by measuring cellular DNA and protein content and by counting the number of cells in the cultures. The cell cycle was completed after 96 h of culture with the S phase peaking at 48 h. Early events in thymocyte activation were enhanced phosphatidylinositol turnover and the induction of ornithine decarboxylase. Concomitant changes were observed in the rates of DNA synthesis and glycolysis accompanied by a 20-fold increase in glucose uptake 48 h after stimulation. However, the maximal increment in the glycolytic rate preceded that of DNA synthesis by 12 h. Apart from the quantitative changes which occurred during the cell-cycle progression, there was also a change from partial aerobic glucose degradation to CO2 (26%) to almost complete anaerobic conversion of glucose to lactate (85%) and less than 3% to CO2. Glycolytic enzyme levels increased fourfold to tenfold and reached their maxima 48 h after mitogenic stimulation. Maximal increments of glycolytic enzyme activities preceded or coincided with the maximal increments of the glycolytic rate. Actinomycin D (1.5 ng/ml) completely inhibited DNA and RNA synthesis but did not show any inhibitory effect either on glycolytic enzyme induction or on enhanced glycolysis. During mitosis and return of the cells to the non-proliferative state, all of the enhanced metabolic rates returned to their initial levels and the elevated enzyme activities were decreased also. The marked changes of metabolic rates and enzyme activities observed at the various phases of the cell cycle suggest that these biochemical events may also serve as suitable parameters for evaluating the response of lymphocytes towards mitogens and lymphokines.

Animals↗
PubMed1988

[Seasonal occurrence of Dicrocoelium dendriticum in intermediate hosts].

Epizootiological questions were studied on a permanent pasture of a farm situated in one of the dicrocoeliasis areas in the GDR during the 1986 grazing season. Helicella obvia snails and Formica fusca ants were found to be first and second intermediate hosts respectively. A total of 1,121 snails and 70 ants were dissected. The infestation rate with Dicrocoelium dendriticum stages in snails decreased in summer after the high spring peak and increased again in autumn. Paralysed ants were found only at temperatures below 20 degrees C. Parthenogenetic stages in snails were identified morphologically according to the structure of cercariae; the metacercariae isolated from the ants' body cavity were determined in animal experiments.

Animals↗
PubMed1987

A clonal analysis of Neisseria meningitidis serogroup A.

A typing scheme has recently been developed for Neisseria meningitidis serogroup A based on the clonal population structure of these bacteria. An international strain collection consisting of 423 group A strains isolated from 23 epidemics or outbreaks since 1963, as well as from older epidemics and numerous non-epidemic situations was used in the analysis. Strains were first segregated into electrophoretic types, depending on the combined score for the electrophoretic mobilities of 7 cytoplasmic isoenzymes resolved by starch gel electrophoresis and of 2 outer membrane proteins resolved by sodium dodecyl sulphate polyacrylamide gel electrophoresis. The bacteria were subsequently assigned to one of 21 clones after numerical analysis of their electrophoretic types. The epidemiological value of the typing scheme was assessed by examining case and carrier strains isolated during (1982-83) and subsequent to (1984-85) an epidemic in the Gambia, West Africa. The case isolates, all of which were serogroup A, were of a single clonal type. All serogroup A carrier isolates were also of this clone, while carrier strains of other serogroups showed greater clonal diversity. These results indicate that case strains during an epidemic show little clonal diversity and thus that the typing scheme is of value in distinguishing the etiology of epidemics. A retrospective epidemiological analysis of the strains in the international collection showed that most serogroup A epidemics were associated with a single or predominant clone, although some epidemics were of mixed etiology.(ABSTRACT TRUNCATED AT 250 WORDS)

Africa↗