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Biomedical subjects

A Sherman

Publications and source records attributed to A Sherman.

At least 91 records · Page 5Linked to original sources
PubMed1980

Hierarchic classification of multiple types of urothelial cells by computer.

A two-level hierarchic classification of 915 urothelial cell images from the urinary sediment was performed by computer using the TICAS programs. The purpose of the analysis was to determine whether adequate discrimination could be obtained among several classes of cells, such as degenerated (DG), multinucleated (MN) and mononucleated well-preserved (WP) ones. The first level in the classification hierarchy showed that the three classes of cells could be identified by computer and that the identification of the group of WP cells was particularly satisfactory, the analysis of WP cells, using training and object sets, documented once again that the identification of diagnostically significant subgroups could be achieved with a very small misclassification error, which was less than 1% for benign (NEG) and malignant (POS) cells. In view of the prior successful application of the classification of images of WP cells to establish patient profiles, the results of the hierarchic classification support the concept of automated analysis of cells in the urinary sediment by computer.

Computers↗
PubMed1980

Computer identification of degenerated urothelial cells.

Computer algorithms were developed to identify very poorly preserved, degenerated urothelial cells from the urinary sediment. Cell images were analyzed by two methods: the first one based on nucleus-finding algorithms (determination of nuclear boundaries) and the second based on the analysis of histograms of optical density. Discrimination between benign and malignant degenerated cells could be accomplished by both methods, although the misclassification of cells rose from +/- 10% by the first approach to +/- 15% by the second approach. Most important, however, useful algorithms were obtained and incorporated into the TICAS file for the identification of this large group of urothelial cells as a significant step in the automated analysis of the cells in thr urinary sediment.

Cells↗
PubMed1980

Computer identification of multinucleated urothelial cells.

Computer analysis of multinucleated urothelial cells from the urinary sediment is reported. The cell images were analyzed by two methods: the first based on nucleus-finding algorithms (determination of nuclear boundaries) and the second based on algorithms derived from the histograms of optical density. Both approaches resulted in good discrimination between benign and malignant cells, although the misclassification rate rose slightly from +/- 7% by the first approach to +/- 10% by the second approach. Algorithms identifying multinucleated cells are now a part of the TICAS file as an important step in automated analysis of cells in the urinary sediment.

Cell Nucleus↗
PubMed1979

Suppressor of deoxythmidine monophosphate uptake in Saccharomyces cerevisiae.

Although yeast cannot normally incorporate exogenous deoxythymidine 5'-monophosphate (dTMP) into deoxyribonucleic acid, mutants able to do so have been isolated. We have characterized a recessive suppressor of dTMP uptake (sot1) that prevents strains carrying either tup1, tup2, or tup4 from growing on selective medium. The sot1 mutation maps between rad1 and the centromere of chromosome XVI, and is unlinked to any of the tup mutations. The sot1 mutation does not suppress the other pleiotropic effects of the tup1 mutant, notably the lack of mating of tup1 MATalpha strains. The sot1 mutation specifically blocks the uptake of dTMP into tup strains. After growing a sot1 strain in medium containing [3H]dTMP, we showed that the medium still contained more than 90% of the original [3H]dTMP and that this medium could support the incorporation of [3H]dTMP by a tup2 strain. Therefore, sot1 strains do not degrade dTMP in the medium. The sot1 mutation had no effect on the uptake of other nutrients essential for growth, including several amino acids, adenine, and uracil.

Chromosome Mapping↗
PubMed1978

Measurement of multiple simultaneous small dimensions and study of arterial pressure-dimension relations in conscious animals.

This paper describes the development of several important modifications that were incorporated into the ultrasonic, transit-time dimension system in order to obtain multiple simultaneous, instantaneous, and continuous measurements of the external dimensions of the aorta and its major branches in conscious, unrestrained animals. At operation a pair of small piezoelectric crystals was sutured to arterial adventitia, and a miniature pressure gauge was implanted in the vessel at the same cross-sectional plane. After recovery from surgery, wall motion was not altered appreciably and scarring was minimal. This technique allows long-term monitoring of aortic pressure-dimension relations and is applicable for small (fetal and neonatal) as well as large (adult dogs and sheep) animals. When vessel wall thickness is measured, stress-radius analysis can be performed so as to compute vascular elastic stiffness as a function of stress. Moreover, the suitability for radiotelemetry of the pressure and dimension signals measured with this technique enables the study of these parameters in unrestrained animals, e.g., during spontaneous severe exercise.

Angiotensins↗