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Biomedical subjects

B Strauss

Publications and source records attributed to B Strauss.

At least 145 records · Page 8Linked to original sources
PubMed1970

Repair of alkylation damage: stability of methyl groups in Bacillus subtilis treated with methyl methanesulfonate.

Bacillus subtilis was not inactivated and was able to replicate even though approximately 3 x 10(4) methyl groups added by methyl methanesulfonate (MMS) were bound to the deoxyribonucleic acid (DNA) of each organism. No significant loss of methyl groups from the DNA occurred for several generations upon incubation of methylated wild-type or MMS-sensitive cells. Single-strand breaks were not observed in the DNA from cells treated at this low MMS dose. Higher doses of MMS resulted in significant killing of both wild-type and MMS-sensitive strains, and the DNA extracted from such treated cells sedimented more slowly than control DNA through alkaline sucrose gradients, indicating the presence of breaks or apurinic sites (or both). These breaks were repaired upon incubation of wild-type but not of MMS-sensitive strains. Repair of damage induced by alkylating agents is probably the repair of breaks which occur as a consequence of high levels of alkylation.

Alkylating Agents↗
PubMed1970

Observations on a model of prolifer- ative lung disease. I. Transpulmonary arteriovenous differences of lactate, pyruvate, and glucose.

Intravenous injections of complete Freund's adjuvant, used by others to stimulate the reticuloendothelial system of small laboratory animals, produced granulomas resembling sarcoid in the lung of the dog. At the height of the disease, when granulomas occupied more than half of the alveolar tissues, transpulmonary arteriovenous (A-[unk]V) differences of lactate, pyruvate, and glucose were measured. When the diseased dogs breathed room air, the A-[unk]V differences of lactate and pyruvate were greater than normal; and when the dogs breathed an hypoxic mixture, the differences increased further. Hence the model affords the opportunity for studying the in vivo metabolism of diseased lungs. It may also prove useful for studying other aspects of granulomatous disease which cannot be easily approached in man.

Animals↗
PubMed1967

Nature of the repair of methyl methanesulfonate-induced damage in Bacillus subtilis.

A nuclease present in extracts of Bacillus subtilis inserts breaks in deoxyribonucleic acid (DNA) treated with the monofunctional alkylating agent, methyl methanesulfonate (MMS), but the nature of the sites within the alkylated macromolecule at which these breaks occur is not known. DNA extracted from B. subtilis cells that have recovered from MMS damage has lost its susceptibility to enzyme action. The recovery process is accompanied by some DNA breakdown and by the incorporation of thymidine. Some recovery from ultraviolet irradiation (UV) and MMS occurred in organisms starved for thymine or adenine, but UV recovery was stimulated by their addition. It is possible that MMS recovery proceeds by a process of excision and repair similar to, but not identical with, UV repair.

Alkylating Agents↗
PubMedDate not supplied

Methylation-induced blocks to in vitro DNA replication.

Single-stranded primed M13mp2 templates and double-stranded templates were treated with either dimethyl sulfate (DMS) or N-methyl-N'-nitro-N-nitrosoguanidine and used for DNA synthesis in vitro. Methylation inhibits the ability of the molecules to serve as templates. When either E. coli DNA polymerase I or AMV reverse transcriptase were used as polymerases, DNA synthesis terminated one nucleotide 3' to the site of adenine residues in the template. Heating of the templates resulted in the appearance of additional termination bands one nucleotide before the site of G's in the template. We assume that methylated A's but not methylated G's are blocks to in vitro DNA synthesis and that heating converts a portion of the sites of methylated G to AP sites which are blocks to synthesis.

Adenine↗
PubMedDate not supplied

The role of DNA polymerase in base substitution mutagenesis on non-instructional templates.

In vitro DNA synthesis on phi X174 or M13 templates with non-instructional lesions such as UV dimers or AP (apurinic/apyrimidinic) sites terminates one base before the site of the lesion when synthesis is catalyzed by T4 DNA polymerase or E. coli polymerase I. E. Coli polymerase I also produces termination bands at the site of AP lesions. Substitution of Mn2+ for Mg2+ and increasing the concentration of dNTP's results in elongation of the newly synthesized strand opposite the site of the lesion and beyond. Purine deoxynucleoside triphosphates are utilized for insertion opposite lesions to a greater extent than are pyrimidine deoxynucleoside triphosphates. Deoxy ATP is used almost exclusively for elongation opposite AP sites with pol I-Klenow fragment in the presence of Mg2+. We suppose that these results illustrate the previously observed greater affinity of polymerases under template-free conditions for purine nucleotides. We also suppose that the results can be used to account for mutagenic base selection on noninstructional DNA templates. If purines are preferentially selected by polymerases, then treatments which inactivate pyrimidines will lead to an excess of transitions whereas inactivation of purines will produce more transversions. Data in the literature support this hypothesis.

Bacteriophage phi X 174↗
PubMedDate not supplied

[The Roemer Award of the German College of Psychosomatic Medicine (1976-1998): quantitative data and contents].

The Roemer-Award of the German College of Psychosomatic Medicine might be the most attractive research award in the German Psychosomatic field. This review starts with an appreciation of its namer, Hans Roemer. Then the award winners between 1976 and 1998 are summarized. Quantitative analyses of the material reveal interesting data about the number of applications during these years and about how the applications and the awarded work are distributed over the different issues of the research field. It is shown that studies dealing with psychosomatic aspects in internal medicine were submitted and awarded most frequently.

Awards and Prizes↗