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Biomedical subjects

P Schulze

Publications and source records attributed to P Schulze.

At least 19 recordsLinked to original sources
PubMed1990

[Predictive value of electron microscopy studies in virological diagnosis].

The negative staining techniques in transmission electron microscopy have been used as a routine tool in viral diagnosis since 30 years. In a short review, different preparation techniques, fields of application, advantages and disadvantages of electron microscopy in rapid diagnostic are discussed. The application of electron microscopy depends on availability of other more effective methods. Some viruses, specially in faecal samples, are identifiable only by electron microscopy till now. Sensitivity and specificity are improved by immune electron microscopy comprising suspension, immunosorbent and immunogold techniques. Using rapid embedding techniques, ultrahistology is a valuable tool in identifying viruses in biopsy samples, too.

Histological Techniques↗
PubMed1978

[Interrelations between environmental factors and skin].

The interrelations between environment-factors, especially microorganisms (fungi, bacteria and viruses) and human skin are discussed. Besides different local disturbances of the skin, the following ways of sensitisation are explained. It is pointed out that new drugs and/or substances must be tested before they can be used in human skin. The most frequent parasites and skin diseases caused by these and their epidemiological situations are mentioned.

Anti-Bacterial Agents↗
PubMed1976

[Physico-chemical properties of swine vesicular disease virus].

Titration of SVDV on primary pig kidney cell cultures revealed a plating efficiency of less than or equal to 0,9 X 10(-3). Concentration and purification of the SVD-Virus propagated on pig kidney cell cultures were done by chloroform treatment, adsorption, differential- and density gradient centrifugation. The following physical parameters were found: SVDV is an isometrical RNA-virus having a diameter of 25,1 +/- 1,0 nm. It is resistent to the action of chloroform, ether and pH. The virus has a sedimentation coefficient of 156 +/- 3S and a bouyant density in CsCl of 1,33 +/- 0,01 g/ml. Within the family of picornaviruses the SVDV belongs to the subgroup of enteroviruses and can be distinguished from the foot-and-mouth disease virus by the difference in pH-sensitivity and bouyant density in CsCl.

Animals↗
PubMed1976

[Various physical and chemical properties of the 73s unit of the foot-and-mouth disease virus].

At all 3 studied FMD-viruses typs O2, A5 and C we could show the 73S unit in the analytical ultracentrifuge and in the electron microscope. 73S unit is found in the normal cycle of purification of virus and by density gradient centrifugation separated and purified. In CsCl pH 7.6 its density is 1.308 +/- 0,005 g/ml. Its sedimentation coefficient has a value of 72.7 +/- 1,5S. In electron microscope it show itself as a empty virus capsid. Its diameter is in partial purified preparations with 25 +/- 1 nm the same as of the virion. Its wall diameter is 2 to 3 nm. Further purification induced defiguration of particles and increase of its diameter. 73S unit dissociates in 19S and 12S units and shows a typical protein-UV-absorption spectrum with a maximum at 276 to 278 nm and a minimum at 250 nm. Emax/Emin is 2.3. Extinction coefficient E276nm is 1,4 mg/cm2. By sucrose density gradient centrifugation and titration of fractions in the complement fixation test it was detected, that croude virus solution contained already the 73S unit.

Antigens, Viral↗
PubMed1975

[Electron microscopy studies on proliferation of foot-and-mouth disease virus in cell cultures. I. Morphologic changes in cell nucleus].

The first morphological indication of FMD infection of a cell culture was in the nucleus. Components of nucleoli became segregated and were finally present only as remnants. It was not possible to distinguish different stages of segregation, as in the case of entero-virus infections, because of the rapidity of FMD virus proliferation. Following changes in nucleoli there was margination of chromatin. Particularly striking was an increase in interchromatin granules. Changes in the nuclear membrane seemed to facilitate the transfer of nuclear material to the cytoplasm. Strongly pronounced dilatation of the peri-nuclear cleft, like that seen in aphthae and other tissues, were rarely visible in infected cell cultures.

Animals↗
PubMed1975

[Electron microscopy studies on the proliferation of foot-and-mouth disease virus in cell cultures. II. Changes in nucleic acid metabolism of the cell nucleus].

BHK cells were infected with FMD virus and treated with tritium-labelled thymidine and uridine for examination by autoradiography under the electron microscope. Labelling of the DNA, examined by autoradiography under the optical microscope, showed inhibition of 3H-thymidine incorporation. For demonstrating RNA labelling of nuclei, some cells were treated with actinomycin D and others were left untreated. Under the lectron microscope there was no evidence of increased 3H-uridine incorporation in the untreated cells after virus infection, but actinomycin treatment increased RNA labelling in extranucleolar parts of the nucleus, evidently RNA synthesis independent of DNA. There was evidence of some synthesis of virus-specific RNA in the nuclei. The extent of virus-specific RNA synthesis in the cytoplasm was less extensive than in the nucleus.

Animals↗
PubMed1975

[Electron microscopy studies on the proliferation of foot-and-mouth disease virus in cell cultures. III. Morphogenesis in cytoplasm].

The previous parts have been concerned with the participation of the cell nucleus in the formation of the RNA of FMD virus. However, the actual morphogenesis of the virus takes place in cytoplasm. In BHK cells, changes attributable to virus infection were visible by the second hour, with the formation of threads and large polysome complexes near the nucleus. Viral particles soon appeared between these structures. There were no pronounced foci of viroplasma, and it seemed that they were not necessary. Simultaneously new membranes formed in the cell. Clumps of viral particles were next visible in the cxtoplasma. The clumps became enveloped and were transported in this way to the periphery of the cell. Elsewhere there was uptake of particles in autophagic vacuoles, an expression of cellular defensive processes. In ultra-thin sections the virions measured 21-25 nm. Within vacuoles the inner part of the virus, the nucleoid, showed greater contrast than the periphery, the capsid. At first there were only slight changes in mitochondria. Liberation of virus by cell rupture occurred only after severe damage to the cell, particularly the lysosome membranes.

Animals↗