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Biomedical subjects

G Burger

Publications and source records attributed to G Burger.

At least 91 records · Page 5Linked to original sources
PubMed1982

Subunit 1 of cytochrome oxidase from Neurospora crassa: nucleotide sequence of the coding gene and partial amino acid sequence of the protein.

A partial protein sequence (223 residues) of cytochrome oxidase subunit 1 from Neurospora crassa has been established. The nucleotide sequence of a cloned mitochondrial DNA segment, including the structural gene coding for the mature subunit 1 (CO I locus) was determined. In contrast to the situation in yeast, the CO I locus in N. crassa is not interrupted by long intervening sequences. A polypeptide of 555 residues with a mol. wt. of 61 000 has been deduced from the reading frame established by protein sequencing. With the exception of the C-terminal part of the polypeptide, the proposed sequences for subunit 1 of N. crassa, yeast, and man are largely homologous. Protein sequencing reveals that a region of low homology close to the C-terminal portion belongs to the structural gene in N. crassa. The DNA sequence coding for the prepiece , which characterizes the polypeptide precursor of the N. crassa subunit 1, has not yet been localized. A RNA species of approximately 6.8 kb has been identified as the CO I transcript. There is no indication of splicing of this large transcript.

Amino Acid Sequence↗
PubMed1982

Ethnicity as a variable in responses to California Psychological Inventory items.

The responses of Black and White subjects to the California Psychological Inventory items were compared. On the average, 34% in each of the 18 scales showed significant differences. Approximately two-thirds of the significant items for the males were also significant for the females. Blacks responded in the keyed direction for over 23% of the items. The results of this study were consistent with the results of previous studies. The implications of the results of this research are discussed. It is suggested that future development of tests of this nature carefully consider the socio-cultural factors that might contribute to differential responses to test items on objective personality tests as assessment devices. Scores obtained by Blacks on the CPI should be interpreted against the background of the results of this study.

Journal Article↗
PubMed1981

Computer recognition of ectocervical cells: image features.

Machine recognition of ectocervical cells has been achieved with good classification success by a number of research groups. Even though a substantial number of cell image features have been introduced, only a moderate number are required for classification. For them, definitions and measures of their discriminatory potential are presented.

Cell Nucleus↗
PubMed1981

Changes in benign cell populations in cases of cervical cancer and its precursors.

In two totally independent experiments, typical intermediate cells were visually selected by experienced cytotechnicians trained in the analysis of monodisperse Papanicolaou-stained ectocervical smears. The smears were carefully diagnosed per se and in correlation with routine smears from the same patients. For specimens of classes exhibiting tumor cells, the diagnosis was histologically verified. About 20 cells per specimen were selected from at least ten specimens per Papanicolaou class, amounting to total sample sizes of about 1,000 cells. In the first experiment, only cell nuclei were SMP scanned; in the second experiment, the whole cells were TV scanned. Correlation and classification analyses were performed; these resulted in the clear demonstration that intermediate cell populations in ectocervical smears are different in patients with different neoplastic gradings.

Female↗
PubMed1980

Estimation of the performance of an array-processor oriented system for automatic Pap smear analysis.

The rapid progress in computer technology makes possible the automatic analysis of thousands of cells on a slide in the field of automatic uterine cancer cytology. Our approach starts with the high-resolution scanning of visually selected and classified single cells determining the training set for discriminant analysis. On the basis of more than 15 morphologic and textural features measured, correct classification results of 95% are reached. Our aim is to speed up our image processing system by means of an Array-Processor, the model AP 120 B from Floating Point Systems. In this study a realistic time estimation of the scanning, segmentation, feature extraction and classification of about 40,000 cells on a slide is performed.

Computers↗
PubMed1980

Binding and inhibitory effect of 2-heptyl-4-hydroxyquinoline-N-oxide in the presence of ubiquinone-3 in Saccharomyces cerevisiae.

1. 2-Heptyl-4-hydroxyquinoline-N-oxide (HpHOQnO) binds to oxidized mitochondria of Saccharomyces cerevisiae with a dissociation constant of 5 x 10(-8) M and with a ratio of 1 mol per mol cytochrome b. 2. After addition of 171 micro M ubiquinone-3 to oxidized mitochondria, 0.3 mol HpHOQnO bind to 1 mol cytochrome b. The binding strength of the inhibitor is not essentially affected. 3. Reduction of mitochondria with succinate results in a strong decrease of the HpHOQnO binding. The dissociation constant could not be calculated on the basis of the applied method. 4. On the basis of the inhibitory effect of HpHOQnO on reduced mitochondria, a dissociation constant of 5 x 10(-6) M is calculated. 5. The respiratory electron flow to oxygen is about 100 times as sensitive to HpHOQnO as the electron flow to cytochrome c. 6. Ubiquinone-3 reverses the inhibition by HpHOQnO and stimulates the electron flow. 7. The different influence of ubiquinone-3 in binding and in inhibition experiments is discussed as a result of redox conditions.

Binding Sites↗
PubMed1980

Oral cholecystography: is the fatty meal always necessary?

In our study we have collected 1000 consecutive cases of oral cholecystographic opacification of the gall-bladder and common bile duct; occasionally a complimentary intra-venous cholangiography had also been carried out. In 360 cases there was disease of the gall-bladder or a faint opacification of the common bile duct was abnormal in only three cases, which is a rate of 0,47%. Therefore the fatty meal after oral cholecystography should not be done in each case but only if there is a presumptive diagnosis of pancreatic disease, if there is pancreatic calcification, or if surgery has been previously performed on the biliary tract or duodenum.

Adult↗
PubMed1979

Progress report of the TUDAB project for automated cancer cell detection.

Two methods for high resolution cell image data acquisition are applied routinely. Cells are either scanned by a computer controlled fast scanning microscope photometer (SMP) or a TV-camera. The software system for digital image analysis was completely revised and implemented on the PR 330 minicomputer. The system contains codes for primary cell data acquisition, segmentation of cells, cell feature extraction and statistical cell analysis. With this system, SMP and TV scanned cell data bases of PAP stained cells in vaginal smears, grouped into several classes, have been built up. Each data base contains 34 primary features and 20 feature combinations for each cell. A linear discriminant analysis is applied routinely for cell classification. The present state of the system and its operation are described, cell features and classification results are shown, and future steps for a prescreening strategy are discussed.

Computers↗
PubMed1977

Extrachromosomal inheritance in Schizosaccharomyces pombe. III. Isolation and characterization of paromomycin-resistant mutants.

In the antimycin--resistant mutant anar-8 of the fission yeast Schizosaccharomyces pombe (Sch.p.) spontaneous mutants were isolated showing high resistance to the aminoglycoside antibiotic paromomycin. All mutants were resistant to the structurally related antibiotic neomycin. Tetrad analysis, mitotic segregation analysis, and mitotic haploidization revealed extrachromosomal, very likely mitochondrial inheritance. In contrast to the rapid segregation of mitochondrial markers in zygotic clones of Saccharomyces cerevisiae (S.c.) the heteroplasmic state of diploids proved to persist for at least 50 generations after zygote formation. Stationary cultures of the paromomycin-resistant mutants parr-106 and parr-112 contain up to 6% respiratory-deficient mutants, but no reversion to paromomycin-sensitivity was observed among 1700-1800 colonies tested. The ability of mutant anar-8 to produce spontaneously respiratory-deficient mutants could be separated from the antimycin-resistant phenotype of anar-8.

Ascomycota↗