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Biomedical subjects

A Wachtel

Publications and source records attributed to A Wachtel.

11 recordsLinked to original sources
PubMed1991

Germ cell tumors in children: gonadal and extragonadal.

Sixty-three pediatric patients with germ cell tumors are presented with details of symptoms, histological findings, staging, serological markers, treatment, and response to therapy. The primary sites were: ovarian 32, testicular 17, presacral 7, mediastinal 3, intraabdominal 2, vaginal 1, and right inguinal canal 1. These patients were treated with T2 (sequential use of dactinomycin, doxorubicin, vincristine, and cyclophosphamide, with or without radiation), T6 (combination chemotherapy with cyclophosphamide, bleomycin, dactinomycin, doxorubicin, methotrexate, vincristine), or VAB treatment protocols (velban, dactinomycin, bleomycin, cisplatin). The cure rate for stage I ovarian and testicular germ cell tumors was 100%; for stage III, all primary sites, 82% and for stage IV, all primary sites, 75%. Histology was prognostic in ovarian tumors of the immature malignant teratoma type; the neural type immature teratoma, grades II and III, had the worst prognosis. Initial debulking surgery in combination with chemotherapy and radiation plays an important role in germ cell tumors. Stages II, III, and IV germ cell tumors require aggressive treatment with surgery, radiation, and chemotherapy. For stage I patients, with primary ovarian malignant tumor, cure with surgery alone can be achieved in 50% of the cases and in testicular tumors in about 70% of the patients. For those with stage I and elevated serological markers, it is feasible to follow these markers and give no treatment until there is evidence of persistent elevation or a rise in titers after an initial fall. In those without elevated serological markers, one should take into consideration the size of the tumor and the histological type before taking the "wait and see" approach. These stage I tumors are highly curable when they first present but, if allowed to recur, chemotherapy may not offer the patient such a favorable response and cure rate.

Adolescent↗
PubMed1984

Canine transmissible venereal sarcoma: tumor cell and infiltrating leukocyte ultrastructure at different growth stages.

Electron microscopic study of the canine transmissible venereal sarcoma (N = 26) at different stages of growth showed that tumors in a progressive phase of growth (N = 12) were comprised mostly of large, round cells with prominent nuclei and nucleoli, a few spindle-shaped cells and collagen fibers, focal areas of necrosis, and lymphocyte infiltrates. Regressing tumors (N = 9) had the fewest viable round cells, greater numbers of infiltrating leukocytes, and were comprised almost entirely of connective tissue (collagen bundles) in the latest stages of regression. The infiltrating leukocytes consisted primarily of lymphocytes, some eosinophils, and neutrophils, but very few macrophages. Round-cell nuclei contained numerous perichromatin and interchromatin granules. Their cytoplasm often had annulate lamellae complexes and large deposits of glycogen. Loosely packed tumor cells had extensive proliferation and elongation of cytoplasmic extensions (filopodia). Evidence for cell-mediated tumor cell lysis was demonstrated by degenerative changes in tumor cells which were closely apposed to lymphocytes. Spindle-shaped cells in regressing tumors had intravacuolar collagen fragments, suggesting a possible degradative capacity by these cells.

Animals↗
PubMed1977

Evaluation of a psychiatric clerkship by videotape.

The authors used a videotape-based objective examination ingeneral psychiatry to assess the clinical competence of medical students who had completed their third-year clerkship. The test has been shown to be a reliable, valid measure of clinical competence. Subjective faculty grading related positively to test scores. Students on one ward had significantly lower overall test scores, with particularly low scores on clinical judgement questions. However, faculty grades for these students were not significantly different. This suggests that the faculty was unable to assess the relative efficacy of its own teaching. The test can provide objective assessment of student clinical competence and is a means of program evaluation.

Clinical Competence↗
PubMed1967

Histochemical localization of phosphatases in Mycoplasma gallisepticum.

Histochemical studies of adenosine triphosphatase and acid phosphatase activity were performed on Mycoplasma gallisepticum. The adenosine triphosphatase activity appears to be localized in the bleb and infrableb regions exclusively and is associated with the cell membrane; acid phosphatase activity is localized in the infrableb region and does not appear to be membrane-associated. These findings are consistent with data from biochemical studies of Mycoplasma cell fractions but, unlike them, reveal that adenosine triphosphatase activity is restricted to a particular part of the cell membrane.

Acid Phosphatase↗
PubMedDate not supplied

Leukemic hypopyon.

A seven-year-old girl was successfully treated for acute lymphoblastic leukemia. Despite clinical remission she developed a monocular hypopyon which was treated successfully with topical and subtenons steroids. When the hypopyon reappeared, a diagnostic paracentesis revealed leukemic cells and a normal aqueous lactate dehydrogenase. Leukemic ocular infiltration may clinically mimic both neoplastic and inflammatory ocular conditions. The combination of paracentesis and lactate dehydrogenase assay greatly aid in the correct diagnosis.

Anterior Chamber↗