Biomedical subjects
Publications and source records attributed to G Randall.
Malaria continues to present staggering morbidity and mortality statistics. In this well-detailed article, the authors examine the increased incidence of malaria in many areas, describe the malarial parasites, discuss the clinical course, pathogenesis, diagnosis, and treatment, and address the issues of transfusion malaria, congenital malaria, immunity, chemoprophylaxis, and vaccine.
Cyclosporin-A levels were determined by radioimmunoassay in plasma or whole blood, using split samples collected from patients receiving this agent as the only form of immunosuppression following allogeneic bone marrow transplantation. In the plasma assay the temperature at which centrifugation took place was critical since the mean levels were approximately 30% higher with separation at 37 degrees C in comparison to 20 degrees C or lower. Furthermore, the level in whole blood samples was 2.4 times higher than that from the matching serum. In addition, anticoagulated blood that had been frozen and then thawed was technically more difficult to pipette and resulted in a recovery of only 83% of the cyclosporin when compared with assay using fresh blood. In contrast, consistent measurements were obtained either when whole blood was stored at 4 degrees C and then well mixed and diluted in buffer immediately prior to use or when such buffered samples were frozen and thawed immediately before analysis. The latter modifications render the whole blood assay a practical and reliable means for monitoring cyclosporin-A concentrations and may avoid excessive and the potentially nephrotoxic levels achieved when plasma levels are held in ranges previously considered therapeutic.
A 31-year-old man had a maxillary sinus infection and osteomyelitis. In vitro lymphocyte transformation studies indicated that he had a specific immune tolerance to Alternaria organisms. The etiologic agent was recovered and was identified as Alternaria alternata.
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Phototherapy has been widely used in the treatment of neonatal hyperbilirubinemia. Recent reports, however, have indicated that fluorescent light may be toxic and mutagenic to mammalian cells. these findings suggest possible long-term side effects with the use of phototherapy. This study was undertaken to determine the effects of phototherapy on hepatic microsomal enzyme activity. The exposure of Sprague-Dawley and Gunn rats to special blue fluorescent light at an average irradiance of 1,200 microW/cm2 resulted in no significant changes in liver microsomal enzyme activity for aniline hydroxylase, p-nitroanisole-O-demethylase, ethylmorphine-N-demethylase, cytochrome c reductase or the quantity of cytochrome P-450. A significant decrease in aniline hydroxylase and p-nitroanisole-O-demethylase activity was observed when liver microsomes were exposed in vitro to special blue fluorescent light. Photoactivated bilirubin did not effect the activity of the mixed-function oxidase enzymes measured under the conditions of this study.
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The in vitro cloning of haematopoietic progenitor cells derived from blood or bone marrow is now an established technique for the study of normal and abnormal blood formation. In semi-solid agar the results are conventionally recorded as the number of clusters or colonies that grow on the plate under controlled culture conditions. However, the demonstration of detailed morphology within these cellular aggregates remains unsatisfactory. Aspiration techniques are cumbersome and invariably disturb cellular relationships within the supporting matrix while supravital staining is limited by variable uptake of dye by the agar. We describe a method in which the entire cell-containing layer is removed from the Petri dish, fixed, and after mounting on a glass-slide, is air-dried. This preparation stains well with a wide variety of biological dyes, is minimally influenced by background colouration of the culture medium and excellent demonstration of morphologic detail is possible. A permanent record of the cellular composition of the culture is easily obtained by mounting the stained agar disc.
Infusion of functional allogeneic granulocytes is rational therapy in pyrexial patients with severe neutropenia when combined with appropriate antibiotic administration. On the basis of our first year's experience we endorse this approach, but emphasise the need for further critical evaluation of these cells, and present an approach to placing this procedure on a more scientific basis.
"Pseudosarcoma", initially considered a benign response of connective tissue to an adjacent squamous carcinoma, is now regarded as a spindle cell variant of epidermoid carcinoma. Nine cases of spindle cell carcinoma of the larynx are presented. Characteristically, the lesion appears as a large, gray, polypoid tumor. In contrast to other reports, a correlation between gross morphology and prognosis could not be made. The prognosis is more closely related to the size and location of the tumor. Biopsy specimens of the tumors in seven of the nine cases showed only the spindle cell pattern. This may be confused with granulation tissue. Spindle cell carcinoma was metastatic to the neck and lungs in three patients. Our average follow-up time was 3.8 years with two of the nine patients dying of recurrent disease. Most of our patients were successfully treated with conservation surgery.
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