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Biomedical subjects

L G Koss

Publications and source records attributed to L G Koss.

At least 163 records · Page 9Linked to original sources
PubMed1980

Computer-based diagnostic analysis of cells in the urinary sediment.

Evaluation of images of cells from the urinary sediment by a computer-based microscope has yielded important preliminary results. Computer identification of benign and malignant urothelial cells can now be accomplished with a small margin of error. Furthermore, 2 categories of atypical urothelial cells can be identified. This information has been applied successfully to the study of 12 patients with bladder cancer, including 3 with non-papillary carcinoma in situ. Computer-generated diagnostic profiles based on a relatively modest number of urothelial cells (60 to 150 per patient) proved to be of diagnostic value. It is anticipated that within a few years a practical computerized system of identification of cells in the urinary sediment can be made available for general laboratory use.

Computers↗
PubMed1980

Desmosome development in an in vitro model.

A model has been devised to study the in vitro formation of desmonsomes. The model is based on the differential labeling of two subpopulations of a desmosome-forming human cancer line (C4I). The labeled subpopulations are dispersed, preincubated separately on a shaking water bath for 24 h to allow the internalization of desmosome fragments and the repair of the cell surface, and then mixed, and allowed to aggregate. Aliquots of the mixed suspension are fixed at various intervals. The time between mixing and fixation represents the maximum age of any junction between dissimilarly labeled cells. The beginnings of desmosome formation were observed within a few minutes after the beginning of aggregation. Close apposition of cell membranes was seen immediately after mixing, followed within 15 min by the appearance of a submembrane density in one or both of the interacting cells. Intracytoplasmic filament formation takes place at between 15 and 30 min. Desmosome formation is complete by 90 min. The process is accompanied by a progressive widening of the extracellular space and the desification and organization of the extracellular material and the submembrane plaques.

Cell Adhesion↗
PubMed1980

Activation of human polyomavirus infection-detection by cytologic technics.

Human polyomaviruses produce characteristic large basophilic nuclear inclusions in urothelial cells. Cytologic screening of urinary sediment for inclusion-bearing cells permits the identification of persons who are actively excreting these viruses. The human polyomavirus-induced changes may be differentiated from changes induced by other viruses and from cancer by transmission electron microscopy of infected cells. Cytologic evidence of virus infection was detected in five of 37 cancer patients receiving various treatments, two of whom were also diabetic, and in two of 84 adult patients who had diabetes mellitus. The monitoring of 3,648 urine samples sent for routine cytologic examination revealed 12 additional patients to have cytologic changes of human polyomavirus infection. Electron microscopy confirmed the presence of polyomavirus particles in seven of the 19 cytologically positive specimens. Previous reports of human polyomavirus excretion have been confined to describing patients whose immunity may have been impaired by drug therapy, congenital disease, or pregnancy. This study indicates that cytologic evidence of active human polyomavirus infection may be found among patients receiving various treatments for a number of medical disorders not usually associated with immunologic defects. Further studies to identify factors concerned in the reactivation of human polyomavirus are indicated.

Adult↗
PubMed1980

Surface configuration of human tumor cells obtained by fine needle aspiration biopsy.

Surface configuration of viable cancer cells freshly aspirated from various malignant tumors such as mammary carcinoma, renal carcinoma, malignant melanoma and oat cell carcinoma were described. Various aspects of surface configuration of tumor cells ranging from numerous microvilli, blebs or ridges, to almost entirely smooth surfaces were found. Microvilli were most commonly seen on surfaces of tumor cells from carcinoma of the breast and from malignant melanoma. There were no specific surface features for any of the tumor cells studied except for oat cell carcinoma. This is in contradistinction to the configuration of cancer cells in effusions wherein most cancer cells are covered by dense, irregular microvilli.

Adult↗
PubMed1980

Configuration of surfaces of human cancer cells in effusions. A review.

This is a report of SEM studies of several cell types observed in pleural and ascitic fluids of patients with a variety of disorders. Prior to scanning, the identity of the cells was determined by light microscopic studies performed by a simple and inexpensive method developed by the authors. Differences in surface configuration of mesothelial cells, macrophages, leukocytes, and cancer cells were described and discussed. Irregular surface microvilli of high density were the predominant surface feature of cells of metastatic cancers of various origins and types, except for oat-cell carcinoma. Mesothelial cells had variable surface configuration with the majority of cells covered by blebs. Macrophages were primarily characterized by veil-like ridges. Detailed description of the various cell types under various circumstances and a discussion of the possible significance of the surface features in reference to cell biology conclude this review.

Ascitic Fluid↗
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

Surface configuration of mesothelial cells in effusions. A comparative light microscopic and scanning electron microscopic study.

Surface configuration of mesothelial cells identified by light microscopy (LM) has been studied by scanning electron microscopy (SEM). It has been shown that mesothelial cells may have a variable SEM appearance. The surfaces of a small proportion of mesothelial cells are covered by regular microvilli (MV) and show openings of the pinocytotic vesicles. The surfaces of the majority of these cells are covered by vesicles or blebs. An intermediate population of mesothelial cells, i.e., cells displaying side-by-side blebs and MV, has also been observed. The latter cells no longer display pinocytotic vesicles. Occasional mesothelial cells have smooth surfaces. It has been shown by LM and transmission electron microscopy that cells with blebs are viable and capable of mitotic activity. It is concluded that mesothelial cells, detached from their epithelial setting, lose microvilli and pinocytotic vesicles and acquire surface blebs. The possible relationship between mesothelial cells and macrophages based on surface features has been discussed.

Animals↗
PubMed1979

Flow cytometric analysis of the DNA distribution in human brain tumors.

Flow cytofluorometric analysis was used to determine the distribution of the DNA content in cells from selected areas of normal human brain and in benign and malignant brain tumors. Propidium iodide was employed as DNA fluorochrome and the analysis was carried out on a suspension of single cells. Normal, nonstimulated human lymphocytes were used as diploid controls. With nonneoplastic tissue an average of 91% of the cells were diploid (presumably in G0 or G1 stage of the cell cycle). The cells of most benign tumors were mainly diploid (77-98%), nine specimens of pituitary adenomas had large numbers of aneuploid cells. In glioblastoma multiforme the proportion of diploid cells was significantly diminished and polyploid cells were frequently seen. Similar results were obtained in other malignant tumors, with metastatic tumors showing the greatest ploidy variation, which included triploid, tetraploid, and hypertetraploid cells. The analytical method used provides valuable information of significant clinical importance on the DNA distribution in brain tumor cells.

Aneuploidy↗
PubMed1979

The prevalence and significance of Brunn's nests, cystitis cystica and squamous metaplasia in normal bladders.

The frequency of Brunn's nests, cystitis cystica and squamous metaplasia was studied by multiple histologic sections in 100 grossly normal bladders obtained at postmortem examination. Of the 100 bladders 93 per cent had at least 1 of the 3 proliferative changes. Brunn's nests and cystitis cystica were seen in 89 and 60 per cent of the bladders, respectively, most often at the bladder neck and trigone. Non-keratinizing squamous metaplasia of the vaginal type was seen almost exclusively on the trigone and bladder neck in 46 per cent of the premenopausal and postmenopausal women but in only 7 per cent of the men. There was no satisfactory evidence that inflammation was casually associated with these changes. These findings suggest that Brunn's nests, cystitis cystica and squamous metaplasia of the vaginal type in women are normal variants of bladder urothelium and have no precancerous potential.

Adolescent↗
PubMed1979

Mapping of the urinary bladder: its impact on the concepts of bladder cancer.

The results of mapping of the urinary bladder are reported and discussed. It has been shown that Brunn's nests, cystitis cystica, and the vaginal type of squamous metaplasia are commonly found in normal bladders and thus cannot be considered as precancerous lesions. Mapping of cancerous bladders and related histologic and clinical observations strongly suggests that there are two distinct pathways in bladder neoplasia: the papillary pathway and the nonpapillary pathway. Papillary tumors with thin stalks must be considered as a focal expression of the proliferative potential of the urothelium. They are per se quite harmless but may be followed by other manifestations of neoplasia. Broad based papillary tumors, regardless of grade, may have "pushy borders," which extend into the lamina propria but rarely invade the muscularis. Nonpapillary flat lesions, notably atypical hyperplasia and carcinoma in situ, appear to be the principal source of invasive and metastasizing bladder cancer. The presence of the flat lesions puts the patient at high risk for the development of invasive carcinoma. Methods of assessment of the cancerous bladder are suggested and discussed.

Adolescent↗
PubMed1979

Comparison of the diagnostic values of biopsies of the pleura and cytologic evaluation of pleural fluids.

Results of a comparison of the diagnostic efficacy of percutaneous needle biopsy of the parietal pleura with that of cytologic examination of pleural fluid sediment obtained concurrently from 166 patients with benign or cancerous pleural disorders are reported. Of 44 patients with confirmatory evidence of cancer involving the pleural surfaces, 43 had positive cytologic findings, whereas pleural biopsies were diagnostic in only 16 cases. Of a total of 122 patients with benign pleural diseases, cytology provided the diagnosis in two cases of eosinophilic pleurisy, and pleural biopsy contributed the diagnosis in four of ten cases of tuberculosis. The data indicate that percutaneous needle biopsy of the parietal pleura is less efficacious in the diagnosis of malignant pleural disease than is cytologic evaluation of the fluid sediment, whereas in the diagnosis of tuberculous pleurisy, pleural biopsy proved superior.

Adult↗
PubMed1978

Flow-through cytometry of meningiomas and cultured meningioma cells.

Flow cytometric techniques were used to compare the DNA content, size and viability of meningioma cells obtained directly from surgical specimens with the same cells after a period of culture. Cells isolated from the original meningiomas and cells in primary culture was similar with regard to size and DNA content, regardless of the histologic subclassification of tumor. The cell populations were essentially diploid with a small proportion of tetraploid cells. Viable cells were smaller and more uniform in size than the nonviable cells. An increase in the number of cells having an elevated DNA content was seen with cultures repeatedly transferred. The latter results suggest that any transfer of information from long-term cultured meningioma cells to the in vivo situation must be done with caution.

Aged↗
PubMed1978

Distribution of T-lymphocytes and B-lymphocytes in peripheral blood and effusions of patients with cancer.

The relative distribution of T- and B-lymphocytes in the blood and in pleural or abdominal effusions was compared among 24 patients with fluid accumulation due to metastatic cancer and 8 patients without evidence of cancer. The data obtained indicated that the mean percentage of T-lymphocytes in malignant effusions was significantly greater than that in the peripheral blood of the same patients. At the same time, the mean eprcentage of B-lymphocytes was decreased in malignant effusions when compared with peripheral blood. Neither of these differences was observed when effusions and blood of patients with nonmalignant effusions were compared. In addition, patients with both types of effusions had fewer total lymphocytes in their blood than did normal control patients, whereas those with cancer-associated effusions had an increased proportion of active T-lymphocytes in their blood.

Aged↗