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Biomedical subjects

H Krause

Publications and source records attributed to H Krause.

At least 109 records · Page 6Linked to original sources

Comparison of microscopy, culture and enzyme immunoassay (Gonozyme) for the detection of Neisseria gonorrhoeae in urogenital specimens.

Urogenital specimens of male patients and female prostitutes were examined for gonorrhoea in a gonococcal antigen enzyme immunoassay (Gonozyme), by microscopic examination of stained smears and by bacterial culture. Out of 18 male patients, 14 showed positive reactions (all 14 by Gonozyme and by microscopy, but only eight by culture also). The sensitivity and specificity of Gonozyme was 100% in reference to microscopy. The predictive value for a positive test and for a negative test was 100%. The sensitivity of Gonozyme in reference to culture was also 100%, but the specificity was only 40%, because of the low yield of positive cultures. The predictive value for a positive test was 57% and for a negative test 100%. Out of 189 female prostitutes, 41 (22%) had a positive reaction in at least one test (Gonozyme, microscopy and culture were positive in 10; Gonozyme and culture in three; Gonozyme and microscopy in 14; Gonozyme alone in 11; culture alone in three). The sensitivity of Gonozyme was 100% and specificity 92% in reference to microscopy. The predictive value for a positive test was 63% and for a negative test 100%. In reference to culture, the sensitivity was 81% and specificity 86%. The predictive value for a positive test was 34% and for a negative test 98%. In prostitutes, the rate of asymptomatic infections was 14%, if one assumed that all Gonozyme-positive results were truly positive. Gonozyme proved to be the most sensitive method for screening female patients. To discriminate possibly false positive reactions, Gonozyme-positive specimens should be corroborated, preferably by bacterial cultivation.

Antigens, Bacterial↗

Characterization of the DNA of the hamster papovavirus: I. Genom length and molecular cloning.

The complete genome of the hamster papovavirus (HaPV) which was isolated from virions found in multiple skin tumors of the Syrian hamsters was measured by electron microscopy and cloned in Escherichia coli using the certified plasmid vector pBR322. The cloned viral DNA were characterized by digestion of the recombinant DNA with various restriction enzymes followed by comparison of their electrophoretic mobilities in agarose gels with that of similarly digested uncloned DNA and by electron microscopy to determine the genome size of cloned HaPV DNA. The restriction enzyme analysis of the cloned HaPV DNA showed the same cleavage pattern as the corresponding fragments from the uncloned DNA. No major insertions or deletions could be detected by heteroduplex analysis between cloned HaPV DNA and the starting material. The estimated genome size of 5.52 kb for HaPV DNA is approx. 300 bases larger than those determined for other known papovaviruses as SV40 or polyoma.

Animals↗

Studies on the SV40-like papovavirus SV40-GBM. II. Molecular cloning in Escherichia coli of variant DNA molecules from glioblastoma-derived virus.

The complete DNA genomes of the SV40-like GBM virus (GBM1), isolated from a human glioblastoma multiforme, and of two discrete classes of GBM DNA molecules that appear following three passages in CV-1 monkey cells at low multiplicities (GBM3-H and GBM3-L), were cloned in Escherichia coli using plasmid vector pBR322. The cloned viral DNAs were characterized (i) by digestion of the chimeric plasmid DNAs with various restriction enzymes followed by comparison of their electrophoretic mobilities in agarose with that of similarly digested uncloned DNA, (ii) by hybridization of digested chimeric plasmid DNAs to 32P-labeled uncloned GBM DNA, and (iii) by electron microscopy. In restriction enzyme analysis the cloned GBM DNAs showed the same cleavage pattern as the uncloned DNAs, indicating that no major insertions or deletions were present. The electrophoretic data were confirmed by electron microscopic heteroduplex analysis.

Cloning, Molecular↗

Studies on the SV40-like papovavirus SV40-GBM. I. Genomic analysis by restriction endonucleases and electron microscopy after propagation in CV-1 monkey cells.

Infection of CV-1 monkey cells with SV40-GBM, a papovavirus isolated from a human glioblastoma multiforme, resulted in the appearance of defective viral DNA molecules. In contrast to SV40 wild-type, two main types of variant DNA molecules could be found after three viral passages at multiplicities of infection of about 10. The molecules of one variant DNA (GBM3-L) were about 19% shorter than the GBM3-H DNA molecules and the DNA of the original GBM isolate, as demonstrated by electron microscopy. Restriction enzyme analysis revealed that GBM3-L DNA had lost both the EcoRI and the HpaII cleavage sites which are located in the late viral genome region. Furthermore, SV40 GBM3-L did not possess the two PvuII sites which are located in the late genome region, and a portion of the GBM3-H and GBM3-L DNA molecules had lost the unique KpnI site. Heteroduplex analysis verified that the rearrangements in the GBM3-L DNA are located only in the late region of this DNA. The possible differences between SV40 wild-type and SV40-GBM are discussed on the basis of these results.

Animals↗

Evolutionary relationships between papovaviruses and their hosts.

The papovaviridae family consists of two genera, the papillomaviruses (PV) and the polyomaviruses (Py-V). Both genera are distinguished by morphological (larger sizes of the PV) and several biological characteristics. The genomes of either of the two genera share highly conserved DNA regions and a common antigenic determinant, located in their major capsid polypeptides. On the basis of these data an evolutionary relationship among the members of PV and Py-V, respectively, has been suggested. No homology has been found for either DNA- or protein sequences between PV and Py-V and the question of a common ancestor for both viral genera remains open. We have started to characterize the genome of a papilloma producing papovavirus of the Syrian hamster (HaPV). Most of the known biological characteristics of the HaPV suggest it should be classified as a papilloma-like virus. However, the molecular weight of about 3.5 X 10(6) daltons found for the circular duplex DNA lies within the range given for SV 40 and polyoma virus (Py). Analysis of the HaPV genome by cleavage with 21 different restriction endonucleases, location of specific binding sites of phage T 4 gene 32 protein and E. coli RNA polymerase on the viral DNA demonstrated that the HaPV differed distinctly from all other currently known papovaviruses. The HaPV genome was also analyzed by filter hybridization and electron microscopy under conditions of varied stringency for nucleotide sequence homology with the genomes of different papovaviruses of both genera. Whereas no homologous DNA regions could be found between the genomes of HaPV and the human PV types 1 and 4, only under nonstringent conditions (Tm-43 degrees C) stable hybrids were formed between HaPV-, SV 40- and the DNA of a PV isolated from Mastomys natalensis (MnPV). On the other hand extensive homology was detected between the genomes of HaPV and Py even under stringent hybridization conditions (Tm-28 degrees C). The homologous DNA segments mapped on the Py and partially on the SV 40 genome were found to be the most strongly conserved DNA regions among the Py-V genus. These results are discussed with respect to a classification of the HaPV within the papovaviridae family.

Animals↗

[Present aspects of syphilis: 2. Serology, therapy].

The actual aspect of syphilis in the Federal Republic of Germany is determined by epidemiology, treponemal specific serodiagnosis and modern therapy. Compared with the frequency after the last war, syphilis diminished to a level of 5-10 per cent at present. In particular, connatal, tertiary and neuro-syphilis have decreased absolutely and relatively. In serodiagnostics of lues venerea the first tests to be used are the indirect hemagglutination-test TPHA and the quantitative lipoidal test VDRL. In case of reactive results in one of these methods, the FTA-ABS-test and furthermore the TPI-test are applied for verification. The treponemal specific IgM-diagnosis (IgM-FTA-ABS, IgM-19 S-FTA) permits a statement on the acuteness of the syphilitic process and control of the course after treatment. In current chemotherapy of syphilis penicillin ranges in the first place followed by tetracyclines and erythromycin.

Erythromycin↗

[The effect of molsidomin on the arterial windkessel (author's transl)].

The antianginal effect of Molsidomin is due to a reduction of preload. The decrease of aortic pressure is interpreted by the diminuation of the cardiac output. It is not yet known whether there is an additional primary reduction of afterload, caused by a change of the elastic properties of the arterial windkessel. Therefore in ten patients the effects of Molsidomin were investigated. After Molsidomin the pulmonary capillary pressure decreased by 58%, and the cardiac index by 12%. Mean aortic pressure was diminished by 12%, too, The capacity of the windkessel C was determined from the diastolic pressure decay in the thoracic descending aorta. After Molsidomin there was a decrease of C by 21%. This decrease was due to a reduction in the filling-state but not to altered elastic properties of the arterial windkessel.

Angina Pectoris↗

Evidence for complexed plastocyanin as the immediate electron donor of P-700.

The reduction of P-700 by its electron donors shows two fast phases with half-times of 20 and 200 mus in isolated spinach chloroplasts. We have studied this electron transfer and the oxidation kinetics of cytochrome f. Incubation of chloroplasts with KCN or HgCl2 decreased the amplitude of the 20 mus phase. This provides evidence for a function of plastocyanin as the immediate electron donor of P-700. At low concentrations of salt and sugar the fast phases of P-700+ reduction were largely inhibited. Increasing concentrations of MgCl2, KCl and sorbitol (up to 5, 150 and 200 mM, respectively) were found to increase the relative amplitudes of the fast phases to about one-third of the total P-700 signal. Addition of both 3 mM MgCl2 and 200 mM sorbitol increased the relative amplitude of the 20 mus phase to 70%. The interaction between P-700 and plastocyanin is concluded to be favoured by a low internal volume of the thylakoids and compensation of surface charges of the membrane. The half-time of 20 mus was not changed when the amplitude of this phase was altered either by salt and sorbitol, or by inhibition of plastocyanin. This is evidence for the existence of a complex between plastocyanin and P-700 with a lifetime long compared to the measuring time. The 200 mus phase exhibited changes in its half-time that indicated the participation of a more mobile pool of plastocyanin. Cytochrome f was oxidized with a biphasic time course with half-times of 70--130 mus and 440--860 mus at different salt and sorbitol concentrations. The half-time of the faster phase and a short lag of 30--50 mus in the beginning of the kinetics indicate an oxidation of cytochrome f via the 20 mus electron transfer to P-700. An inhibition of this oxidation by MgCl2 suggests that the electron transfer from cytochrome f to complexed plastocyanin is not controlled by negative charges in contrast to that from plastocyanin to P-700.

Chlorophyll↗