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Biomedical subjects

M Bopp

Publications and source records attributed to M Bopp.

14 recordsLinked to original sources
PubMed1991

Cloning and expression in Escherichia coli of opc, the gene for an unusual class 5 outer membrane protein from Neisseria meningitidis (meningococci/surface antigen).

A genomic library was constructed in a lambda gt11 vector using chromosomal DNA from a meningococcal serogroup A strain and plaques expressing the class 5C protein were recognized by screening with specific monoclonal antibodies. The opc insert was subcloned into a multicopy plasmid which induced expression of that protein in Escherichia coli as a surface-exposed major outer membrane protein. The nucleotide sequence of opc is typical of an outer membrane protein with a promoter and terminator region, a leader peptide which is cleaved during expression and a complete open reading frame. Unlike other meningococcal class 5 proteins or gonococcal P.II proteins, the sequence did not contain any pentanucleotide repeats and the sequence showed little homology to these other functionally related proteins. However, the predicted amino acid sequence of the mature protein for opc showed 27% similarity to that for a second opa gene cloned from the same meningococcal strain. This is the first report of cloning and expression of a functional meningococcal gene encoding a class 5 outer membrane protein in E. coli.

Amino Acid Sequence↗
PubMed1991

Variation in class 5 protein expression by serogroup A meningococci during a meningitis epidemic.

Serogroup A meningococci were isolated from patients and healthy carriers in The Gambia between 1982 and 1988. The class 5 proteins expressed by these bacteria were identified by electrophoretic migration and by serologic tests. Three protein serologic groupings (seroclasses) called A (protein 5a), B (proteins 5b, 5d, or 5e), and C (protein 5c or 5C) were found among 331 bacterial isolates. The number of class 5 proteins expressed per isolate varied from none to four, with a median of two. The class 5 protein composition differed for certain paired isolates obtained from the nasopharynx, blood, and cerebrospinal fluid of diseased patients and for certain pairs of sequential isolates from the nasopharynx of healthy carriers; the medical relevance of this variation remains unclear, although the 5C protein was preferentially isolated from the nasopharynx and the 5a protein from diseased patients. The data show that a large proportion of healthy carriers in The Gambia were exposed to bacteria expressing each of the three seroclasses and that many people were exposed to bacteria expressing each of the three seroclasses and that many people were exposed to two or all three seroclasses during the epidemic of 1982-1983.

Antibodies, Monoclonal↗
PubMed1989

[Cartography as an instrument in epidemiology: methodologic considerations for the new Swiss cancer atlas].

Maps not following the syntactical rules of the graphical language entail the risk of being misunderstood. Maps aim at demonstrating spatial patterns and visualizing dividing lines. Representation of tabular values is not a principal goal. Maps should be "seen" as a whole, not be "read" element by element. Some technical aspects of cartography are discussed (distortion of information, grouping of data, adequacy and use of colour). The guidelines for the new Swiss cancer atlas are based on these general principles. A continuous-shading technique avoiding class intervals is being used. It allows the combination of maps and diagrams of different aggregations of the same data using a common shading scale. Indications of significance are integrated into all figures. Geographical maps are enriched by diagrams showing data for 9 cities, 5 language regions, for a grouping by size of community and for a socioeconomical classification of regions. The universal shading scale enables to compare the figures separately and crossways. Relationships not apparent in a traditional map might be revealed.

Atlases as Topic↗
PubMed1988

[New findings in Oguchi disease].

The authors report on clinical and electrophysiological studies of a patient with Type I Oguchi's disease. Numerous small pigmentations of the retinal pigment epithelium (RPE) causing focal disruption of the Oguchi reflex were observed, a phenomenon which has not previously been reported. Consistent with reports of pathologic changes in the RPE, an abnormal electro-oculogram (EOG) was recorded in this patient. On the basis of this information, the pigmentations were interpreted as dysplastic changes.

Adolescent↗
PubMed1986

[Pattern ERG in X-chromosome juvenile retinoschisis].

Typical electroretinographic findings in x-chromosomal juvenile retinoschisis are a normal a-wave and a reduced b-wave suggesting that the primary defect is located at the level of the bipolar cell layer whereas deeper retinal structures are not basically affected. The marked amplitude reduction in the pattern-ERG suggests to look for the origin of response in the inner retinal layer or in subsequent structures.

Child↗
PubMed1985

[Autosomal dominant infantile optic atrophy: ascending or descending degeneration?].

All patients with autosomal dominant infantile optic atrophy had a normal electro-oculogram (EOG) and a normal luminance electroretinogram (L-ERG). Patients with a typical blue sensitivity defect at the time of investigation had a normal pattern electroretinogram (P-ERG), while the visually evoked cortical potentials to pattern stimuli (P-VECP) showed a delayed latency and a decreased amplitude. Only in severe cases of the disease where the blue sensitivity defect was masked by a progressive concomitant colour blindness was there a reduced amplitude in the P-ERG. The P-VECP in these cases was not recordable. The findings suggest that the primary process in autosomal dominant infantile optic atrophy is in the optic nerve, the inner layers of the retina being affected secondarily.

Adult↗
PubMedDate not supplied

Lung cancer patterns in Switzerland: a search for geographical and occupational patterns.

Simple descriptive methods (geographical correlation, variance and covariance analysis; gradients of mortality by quantiles; proportionate ratio methods) have been used to characterize the distribution patterns of lung cancer in Switzerland since 1969: Geographical patterns. In males, the temporo-spatial distribution of lung cancer mortality indicates that male smoking became prevalent earlier in the conurbations than in the countryside. The culturolinguistic gap between the German and French/Italian-speaking parts is mirrored by higher lung cancer rates in the latter. For female lung cancer the urban-rural gradient overshadows differences between the linguistic regions. Occupational patterns. The consistency of occupationally associated lung cancer risks within Switzerland is remarkable, even in small occupational groups with only a few deaths, and parallels the patterns known from international statistics. An analysis of lung cancer incidence within the Zurich cancer registry by histological types reveals the same consistent patterns with high risks in blue-collar trades.

Adolescent↗