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J Bollmann

Publications and source records attributed to J Bollmann.

10 recordsLinked to original sources
PubMed1991

Allelic interactions at the nivea locus of Antirrhinum.

Most null alleles at the nivea (niv) locus are recessive to Niv+ and, when homozygous, give white flowers rather than the red of the wild type. In contrast, the niv-571 allele is semidominant; although it gives white flowers when homozygous, very pale flowers result when this allele is heterozygous with NIV+. We showed that in heterozygotes, niv-571 acts in trans to inhibit expression of its Niv+ homology 25-fold to 50-fold. The inhibition is reversible after meiosis and partially reversible somatically. The niv-571 allele carries a transposable element Tam3 insertion and three truncated copies of the niv gene, one copy being in inverse orientation. Analysis of two further niv alleles, niv-572 and niv-527, showed that excision of Tam3 from niv-571 does not affect the ability of the allele to repress Niv+ and that one truncated niv copy alone is insufficient to confer semidominance. The detailed structures of various semidominant niv alleles suggest that their effects in trans are not readily explained by production of antisense RNA but are more easily reconciled with a direct recognition/interaction between homologous genes, reminiscent of cosuppression and transvection phenomena described in other systems.

Acyltransferases↗
PubMed1986

Rapid activation by fungal elicitor of genes encoding "pathogenesis-related" proteins in cultured parsley cells.

Administration of a cell-wall preparation from the fungus Phytophthora megasperma f. sp. glycinea, which acts as an elicitor of phytoalexin production in cell suspension cultures of parsley (Petroselinum crispum), also results in a rapid and dramatic increase in the relative amounts of mRNAs coding for a number of small proteins having low isoelectric points. According to various operational criteria, the translation products are classified as "pathogenesis-related" (PR) proteins. Here we report that the cDNA inserts of two pBR322-derived plasmids, pcPR1 and pcPR2, are homologous to mRNAs coding for one (PR1) and three (PR2) of these proteins in hybrid-selected in vitro translation experiments. Nuclear run-off transcription studies show that activation of the corresponding genes is extremely rapid; we observed a 4-fold increase in the transcription rate of the PR1 gene within 5 min and a 3-fold increase for the PR2 gene within 20 min following elicitation. Subsequent increases in the amounts of PR1 and PR2 mRNAs indicate that regulation of PR protein synthesis occurs at the transcriptional level.

Journal Article↗
PubMed1980

[Computer tomography in the investigation of the suprarenal gland (author's transl)].

The computer tomographic appearances of pathological processes in the suprarenal were evaluated in 55 patients; consideration is given to individual normal variations and to various sources of error. It is concluded that adrenal computer tomography is the primary radiological means of diagnosis, particularly for diseases which deform the contours of the glands. Usually angiography is unnecessary. The structure and density of various adrenal masses, and their behaviour after intravenous contrast, usually provide a fairly accurate diagnosis. Nevertheless, exact evaluation of the findings can only be made in the clinical context and decisions regarding treatment should be the result of an interdisciplinary approach.

Adrenal Gland Neoplasms↗
PubMed1979

[Computer tomography and retroperitoneal fibrosis (Ormond's disease) (author's transl)].

Four patients with retroperitoneal fibrosis (Ormond's disease) were examined by computer tomography; the appearances are described and the differential diagnosis discussed. Computer tomography clearly defines the proliferative-inflammatory process and together with conventional radiology, angiography and lymphangiography it permits a presumptive diagnosis of retroperitoneal fibrosis. The non-invasive nature of computer tomography makes it the method of choice for follow-up of this disease.

Aged↗
PubMed1979

[Drainage following urological surgery].

Prolonged leakage of urine and infection are the most troublesome complications following surgical exposure of the lumen of the urinary tract. The available methods of wound and urinary drainage are discussed. Careful attention should be paid to the material from which the drain is manufactured, because of long periods of drainage in a closed system.

Drainage↗