Biomedical subjects

D J Debono

Publications and source records attributed to D J Debono.

4 recordsLinked to original sources

PubMed1997

Decision analysis for avoiding postchemotherapy surgery in patients with disseminated nonseminomatous germ cell tumors.

PURPOSE: This retrospective study was undertaken to assess the outcome of patients with disseminated nonseminomatous germ cell tumor (NSGCT) managed under a postchemotherapy strategy developed at Indiana University. PATIENTS AND METHODS: This is a retrospective analysis of 295 consecutive patients with disseminated NSGCT treated with primary chemotherapy at Indiana University from 1987 to 1994. The patients were placed into five groups based on response to primary chemotherapy and the presence or absence of teratoma in the primary tumor. The 295 patients were divided as follows: group A (complete remission [CR]) n = 78; group B (unresectable), n = 50; group C (serologic CR, teratoma-positive primary tumor, resectable partial remission [PR]), n = 90; group D [serologic CR, teratoma-negative primary tumor, < 90% radiographic PR], n = 50; and group E (serologic CR, teratoma-negative primary tumor, > or = 90% radiographic PR), n = 27. Groups A, B, and E patients were routinely observed after chemotherapy, whereas groups C and D patients were routinely taken to postchemotherapy surgery. RESULTS: The percent of patients who continuously had no evidence of disease (NED) were as follows: group A, 92%; group B, 40%; group C, 87%; group D, 86%; and group E, 74%. In assessing group A patients, the bulk of retroperitoneal disease at presentation had no influence on ultimate outcome. CONCLUSION: Patients with NSGCT who achieve a serologic and radiographic CR with primary chemotherapy (group A) can be safely observed without surgical intervention, regardless of initial tumor bulk. Patients with a teratoma-negative primary tumor who achieve a serologic CR and a > or = 90% radiographic remission and are followed-up without surgical resection (group E) are at an increased risk of relapsed NSGCT. Decisions about postchemotherapy resection in this group remain complicated and controversial. Options include observation with serial radiologic evaluation or surgical resection of persistent mass or masses.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1996

Thymic neoplasms.

Thymic carcinomas and thymomas are neoplasms of the epithelial cells of the thymus. Extensive study of the histopathology of these tumors has provided insight into the clinical behavior of various pathological subtypes. Establishment of a uniform staging system has facilitated the prospective study of thymic tumors, and it has helped to provide the necessary framework for international cooperation in the study of these diseases. This review explains the pathological nomenclature used in the classification of these tumors, examines the prospective clinical trials that have been completed to date, and discusses the interesting paraneoplastic phenomena associated with thymomas.

Clinical Trials as Topic↗

PubMed1987

Relationship of phosphatidylinositol bisphosphate hydrolysis to calcium mobilization and functional activation in fluoride-treated neutrophils.

Sodium fluoride (20 mM) effected rapid hydrolysis of phosphatidylinositol bisphosphate (PIP2) in human neutrophils. Intracellular free Ca2+ levels increased after PIP2 hydrolysis but before respiratory burst activation. Both the increase in intracellular free Ca2+ levels and the extent of functional activation were dependent on the availability of extracellular Ca2+. The rate of F(-)-stimulated PIP2 hydrolysis, however, was not affected when the rise in cytosolic Ca2+ was severely limited by depletion of extracellular Ca2+. Fluoride caused the specific hydrolysis of PIP2 in isolated neutrophil plasma membranes. This effect occurred in the presence of low levels of available Ca2+ and was accompanied by the release of inositol phosphates. We conclude that PIP2 hydrolysis is an early event in the response of neutrophils to F-. This response is not Ca2+-regulated but may lead to an influx of Ca2+ from the extracellular medium. Activation of a PIP2-specific phospholipase independent of a change in cytosolic free Ca2+ levels may be the initial event in the stimulus-response pathway triggered by fluoride.

Calcium↗

PubMedDate not supplied

Reduced urinary aldosterone excretion rates with normal plasma concentrations of aldosterone in the very elderly.

Although aldosterone production declines with age, so does the aldosterone metabolic clearance rate (MCR), and the net effect of age on the circulating level of aldosterone may be less than can be predicted from production rates alone. The effect of age on aldosterone production and plasma levels was studied in a group of elderly individuals at a very advanced age when susceptibility to the impacts of age might be particularly pronounced. Seventeen nursing home patients, ages 75-99 (mean age 86 years), had aldosterone production assessed from the urinary excretion rate of the acid hydrolyzable 18-glucuronide conjugate of aldosterone. Aldosterone excretion was low in the elderly when compared to a group of healthy, young to middle-aged subjects: 123 +/- 19 (SEM) vs. 234 +/- 18 ng/h (P less than 0.001). However, plasma aldosterone concentrations in the elderly were well within a range observed in much younger and fully ambulatory subjects: 14.1 +/- 1.3 in the elderly vs. 15.9 +/- 1.8 ng/dL in the young. The plasma aldosterone concentration was apparently maintained at a normal level by a coincident decrease in both the metabolic clearance rate and the aldosterone production rate. In conclusion, an aldosterone deficiency state resulting from an age-correlated reduction in aldosterone production is probably uncommon in the elderly.

Aged↗