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Biomedical subjects

M M Webber

Publications and source records attributed to M M Webber.

At least 73 records · Page 4Linked to original sources
PubMed1977

Ultrastructure of human prostatic epithelium. Secretion granules or virus particles?

The objective of this report is to demonstrate that only slight and superficial similarities exist between true virus particles and secretion granules in human prostatic epithelium. In spite of this, secretion granules have sometimes been called virus or virus-like particles. With the current interest in the possible role of viruses in the etiology of some human cancers, many investigations are in progress in search of human tumor viruses. The presence of RNA virus particles in normal as well as tumor tissues derived from animals and man, further complicates the picture. Also, in view of the fact that recent studies indicate an association between herpes simplex type 2 virus and cervical cancer, the possibility of the involvement of the same virus, which has a venereal mode of transmission, in prostatic and other genitourinary cancers in the human male has been considered. Investigators with peripheral interests in such studies are cautioned against making quick decisions on the nature of the "virus-like particles" often observed in secretory cells because these particles often happen to be cell organelles.

Cell Nucleus↗
PubMed1977

Present status of MA-160 cell line. Prostatic epithelium or HeLa cells.

This report reviews the background and the present status of the MA-160 cell line. This cell line was reported to have arisen from tissue cultures of a human, benign prostatic adenoma and consequently has been used for investigations on the prostat and on hormone-dependent cells. Recent studies using chromosome analysis by banding techniques, glucose-6-phosphate dehydrogenase (G6D) electrophoretic mobility, and a specific prostatic acid phosphatase test indicate that MA-160 is not of prostatic origin but a HeLa cell contaminant, arising as a result of intraspecies cell contamination. It is suggested that whenever spontaneous transformation is observed in vitro and established cell lines are being used in the laboratory, the cells in question be thoroughly checked with the currently available chromosomal, biochemical, and cytochemical methods in order to establish their origin and to rule out interspecies and intraspecies cell contamination.

Adenoma↗
PubMed1977

Fibrinogen uptake test. Criteria for interpretation of results in patients with venous thrombosis.

Accurate detection of active deep venous thrombosis with the fibrinogen uptake test (FUT) requires adherence to rigid criteria for interpretation of results of the tests. In a series of 56 patients, only detection of serial increase of per cent uptake at the same position correlated with presence of active venous thrombosis in all cases. Other investigated criteria, which were based on the analysis of single FUT results, showed a 21% incidence of false positive results. Accordingly, active venous thrombosis investigation by FUT requires performance of serial tests and analysis of the curve of uptake at each position to detect serial increasing per cent uptake.

Fibrinogen↗
PubMed1977

Arterial scan versus radiographic angiography in detection of shallow arterial ulcers.

A comparison of 99m-technetium albumin aggregated arterial scan and radiographic angiography for detection of shallow intimal carotid artery ulcerations was made in a series of 12 anesthetized dogs, having a total of 16 acute arterial ulcerations. Radiographic angiography showed positive findings related to presence of stenosis or mural thrombosis in 12 instances. Direct visualization of ulceration was only exceptionally encountered. Arterial scan detected 14 of 16 intimal ulcers. The radionuclide method was reliable even in absence of stenosis or when only minimal mural thrombosis was present. Moreover, autopsy scan of the isolated arterial segments detected all 16 intimal lesions. These results indicate that the arterial scan was a more reliable method for detection of shallow arterial ulcers in this experimental model than radiographic angiography, especially when arterial lumen stenosis or mural thrombosis were minimal or absent.

Angiography↗
PubMed1976

Thrombosis detection using radionuclide techniques.

Radionuclides have been used in the evaluation of intravascular thrombosis for several years. The most widely accepted nonimaging technique is I-125 labeled fibrinogen. It is commonly used for patients who have a high probability of developing a thrombus (e.g., those undergoing surgery). Other techniques are emerging as having value in thrombosis detection. These techniques include radionuclide venography and clot localization scanning techniques utilizing the affinity of clot for small radiolabeled particles, as well as imaging techniques using I-131 labeled fibrinogen. More recently, a number of the above-mentioned techniques have been applied to patient problems. The FDA ban on commercial radiolabeled fibrinogen in the United States has promoted the development of alternative techniques and the use of autologous fibrinogen. A number of other techniques for thrombosis detection have also been explored on a more experimental basis. They include the use of thrombolytic agents such as streptokinase, urokinase, and white blood cells, as well as platelets. The common lung or pulmonary perfusion scan using macroaggregates of albumin or microspheres radiolabeled also gives information as to the presence of thrombosis of embolus within the pulmonary arteries, by showing the effect upon the perfusion pattern. This review will explore in detail the principles, as well as the present and prospective usefulness of the techniques currently available.

Antibodies↗
PubMed1976

Cytopathic effects in primary epithelial cultures derived from the human prostate.

Normal, benign, and malignant human prostatic tissue was cultivated in vitro. Cytopathic effects in derived epithelial cells were examined. Light microscopy revealed polykaryocyte formation, vacuolation, cytoplasmic bridges and processes, nuclear inclusions, increased acid phosphatase activity at the cell membrane of polykaryocytes as compared to mononuclear cells, and cell rounding and clumping. Electron microscopy of the polykaryocytes showed nuclear membrane proliferation and protrusion, scarlike nuclear inclusions containing microfibrils, and virus-like particles similiar to viral nucleoids and nucleocapsids. The latter were also observed in the cytoplasm. The above alterations are similar to those induced by known herpesviruses. The significance of these changes, the possibility of the presence of a latent herpesvirus in the prostate, and its role in neoplastic disease are postulated.

Acid Phosphatase↗
PubMed1975

Radioisotope detection of venous thrombosis. Venous scan vs fibrinogen uptake test.

Experience with the fibrinogen uptake test and the technetium Tc 99m albumin aggregated venous scan in 89 patients showed the latter to be adequate for simultaneous screening for plumonary embolism and venous thrombosis of the lower extremities and pelvis. Because the fibrinogen uptake test differentiated active from inactive venous thrombosis, it is indicated when anticoagulation is considered for patients with a history of thrombophlebitis and equivocal clinical findings of acute activity. It can also be used to monitor high-risk patients and to detect proximal propagation of thrombi. The results of the technetium venous scan were abnormal in 97% of patients with venous thrombosis and the fibrinogen uptake test detected 100% of patients with acute activity. Both tests react to different aspects of the thrombotic disease, thus complementing each other. Because of their reliability, indications for phlebography are now less frequent.

Albumins↗
PubMed1975

Inferior vena cava interruption: a new indication?

Propagating illofemoral venous thrombosis that occurs despite adequate anticoagulation can be detected by the serial fibrinogen uptake test. Twenty-three patients who were receiving heparin sodium for confirmed iliofemoral thrombophlebitis underwent the serial fibrinogen uptake test. There was an increasing percentage of isotope uptake at the groin and the upper part of the thigh in eight of these patients, three of whom subsequently developed clinical signs, perfusion, and ventiliation lung scan findings compatible with the occurrence of pulmonary embolism. The remaining 15 patients had decreasing serial fibrinogen uptake during heparin therapy and no sequelas indicative of pulmonary embolism. Progressive thrombosis in adequately heparinized patients indicates failure of anticoagulation therapy and, when this occurs, we believe that interior vena cava interruption should be considered before a first, but potentially lethal, pulmonary embolus develops.

Femoral Vein↗
PubMed1975

Stromal hypocellularity and encapsulation in organ cultures of human prostate: application in epithelial cell isolation.

The primary objective of our study was to obtain pure cultures of prostatic epithelium. The phenomena of encapsulation by epithelial cells and hypocellularity in stroma occurred when explants of human prostatic tissue were maintained in suspension cultures. Hypocellularity progressed with time and was more pronounced in encapsulated explants. When encapsulated explants were allowed to attach to the substrate they formed an outgrowth of epithelial cells in a monolayer. The significance of these findings is in the use of the described changes in isolating and establishing epithelial cultures of human prostatic epithelium. These cultures are required for studies on the biology of prostatic epithelium and the etiology and treatment of prostatic neoplasia.

Aged↗
PubMed1975

Long-term persistence of cytomegalovirus genome in cultured human cells of prostatic origin.

Cells from prostatic tissue obtained from a 3-year-old male donor exhibited scattered foci of cytopathology on primary culture. A virus was isolated and shown by serological analysis to be cytomegalovirus (CMV). After a number of cell culture passages, a cell line (disignated CMV-Mj-P) was obtained in which foci of infection could no longer be demonstrated, nor could virus be rescued. On continued passage the doubling time of the cells decreased markedly, and the fibroblastoid cells ceased to demonstrate contact inhibition. CMV-specific antigen(s) was detected on the surface of the cells by indirect immunofluorescence techniques after exposure of the cultures to iododeoxyuridine. Microcytotoxocity tests established that CMV-Mj-P cells, but not control human prostate cells or human embryonic lung cells, share a membrane antigen with hamster cells transformed by CMV. Nucleic acid hybridization studies revealed that virus genetic information was carried by the human prostate cells and that the cells contained an average of about 10 to 15 genome equivalents of CMV DNA. Karyotypic analysis confirmed that the CMV-Mj-P cells were of human male origin. These results indicate that the cells either have been transformed by CMV or are chronically infected with CMV and releasing virus at levels below detection.

Antigens, Viral↗
PubMed1975

Ultrastructural changes in human prepubertal prostatic epithelium grown in vitro.

Ultrastructural changes in the prepubertal human prostatic epithelium maintained in vitro are described and are compared with the ultrastructure of the same tissue before culture. In cultured cells, rough endoplasmic reticulum and Golgi complex are poorly represented and the latter also loses its polarity. Increase in cytoplasmic microfilaments is discussed in relation to possible vitamin A deficiency. Primary and secondary lysosomes, arising from autophagy and endocytosis, occur in large numbers as autophagosomes, myelin figures, residual bodies, and multivesicular bodies. Prostatic acid phosphatase activity, an important secondary sex characteristic, is influenced by sex hormones and malignancy; since this enzyme is lysosome-associated, special emphasis is placed on lysosomal changes. Some ultrastructural changes in rough endoplasmic reticulum, Golgi complex, and the lysosomal system are similar to those observed after castration. This study presents ultrastructure of cultured cells which form the basis for studies involving neoplastic transformation, aging, and hormonal manipulation using an in vitro model. This is necessitated by the absence of an in vivo animal model for prostatic neoplasia; hence studies on prostatic oncogenesis, and age-related phenomenon, must be done on cells in vitro. Significance of this study is enhanced by the fact that normal human prepubertal prostate has not been studied before and normal viable prostate is generally not available for investigations.

Acid Phosphatase↗