Search PubMed⌕ Search

Biomedical subjects

R Simon

Publications and source records attributed to R Simon.

At least 469 records · Page 26Linked to original sources
PubMed1977

Prognostic factors for advanced diffuse histiocytic lymphoma following treatment with combination chemotherapy.

Combination chemotherapy can dramatically improve the survival of those patients with advanced diffuse histiocytic lymphoma who enter complete remission. The age, sex, stage, constitutional symptoms, sites of disease and tumor mass of 56 consecutive patients with advanced diffuse histiocytic lymphoma were analyzed as prognostic factors. Twenty-four patients received cytoxan, vincristine, procarbazine and prednisone (C-MOPP) and 32 patients received bleomycin, adriamycin, cytoxan, vincristine and prednisone (BACOP). In 26 of 56 (46 per cent) a complete remission was achieved, in 21 of 56 (38 per cent) a partial remission and in nine of 56 (16 per cent) no response. Median survival with a complete remission was not reached at three years with 82 per cent still alive, but was significantly greater than with a partial remission (7.6 months median) or no response (3.2 months median). Survival of those with a partial remission and no response did not differ statistically. Stage IV disease, bone marrow involvement, gastrointestinal involvement and a tumor mass greater than 10 cm in diameter in a single location were all poor prognostic factors. No other analyzed factor significantly affected survival in this study. Complete response rates and survival curves for patients treated with C-MOPP were similar to those treated with BACOP.

Adult↗
PubMed1977

Growth curve of an experimental solid tumor following radiotherapy.

Because it has long been recognized that the growth of most untreated tumors is well described by Gompertzian or exponential growth curves but that the growth of treated tumors has never been well characterized mathematically, we developed and applied an equation that, while not dependent on restrictive assumptions or unmeasurable variables, was nevertheless capable of describing perturbed as well as unperturbed growth. For the 3964A rat hepatoma, a functional relationship between dose level of radiotherapy and growth-curve response was derived and used for predictive purposes. An implied relationship between tumor size and sensitivity to therapy and some clinical implications were examined.

Animals↗
PubMed1977

Cardiac metastases in lung cancer.

Cardiac metastases from bronchogenic carcinoma are not commonly diagnosed prior to death. This study isolates factors associated wtih the development of cardiac involvement. Four hundred eighteen consecutive patients with lung cancer who had autopsies were studied. Twenty-five percent of these patients had cardiac involvement. Factors associated with cardiac metastases were (1) histologic cell type of the tumor, (2) aggressive therapy, (3) extent of disease, and (4) tumor differentiation. The presence of cardiac metatases was not related to the length of survival. Clinical signs of cardiac involvement included an enlarging heart on the chest x-ray film, development of congestive heart failure, or electrocardiographic changes. Suspicion of cardiac metastases in high-risk individuals, prompt diagnostic evaluation, and rapid institution of therapy may improve the outlook for many patients, since reaccumulation of fluid was generally slow.

Adenocarcinoma↗
PubMed1977

Adaptive treatment assignment methods and clinical trials.

This paper provides a general review of adaptive experimental designs which utilize accumulating information for assigning the best treatment to the most patients in clinical trials. The historical development of such methods is traced. Though the statistical literture on adaptive designs has developed rapidly and continues to grow, the methods are almost totally unused in practice. An extensive evaluation of why adaptive designs are rarely used in clinical trials is presented. It is asserted that most published methods have important deficiencies that render them unsuitable for application. Suggestions are offered for reorienting this area of research into directions that are potentially more useful for clinical trials.

Biometry↗
PubMed1977

Evaluation of adriamycin and dibromodulcitol in metastatic breast carcinoma.

A phase 1 to 2 evaluation of a combination of adriamycin (ADR) and dibromodulcitol (DBD) was performed in patients with progressive, metastatic breast carcinoma. All but one patient had been treated previously with chemotherapy. ADR was given on Day 1 or Days 1 and 8, and DBD was given on Days 1 to 10 of each 21- to 28-day treatment cycle. Side effects were evaluable in 54 patients, and 50 patients were evaluable for therapeutic response. The dose-limiting toxicities were leukopenia and thrombocytopenia. The severity of both toxicities increased as both the ADR and DBD doses increased; however, the effect of increases in DBD dose was much more profound. The mean white blood cell count and platelet nadirs occurred, respectively, on Days 15.3 and 15.9; both nadirs were delayed for 0.6 day by each 30-mg/sq m/day increase in the DBD dose and delayed for 1.7 to 3.9 days using the Day 1, 8 rather than the Day 1 ADR schedule Recovery of the peripheral counts by Day 29 was prolonged by the Day 1, 8 ADR schedule and by increasing the DBD dose. A tolerable dose schedule for previously treated patients was considered to be ADR, 40 mg/sq m on Day 1, and DBD, 135 mg/sq m on Days 1 to 10 repeated every 28 days. Responses were observed in 46% (23 of 50) of the patients. There were 1 complete remission, 19 partial remissions, and 3 improvements. Thirteen patients showed no change and 14 developed progressive disease. There were responses in 13 of 37 (36%) with visceral dominant disease as compared to 7 of 8 (87%) with osseous and 3 of 5 (60%) with soft tissue-dominant disease. There were 22 of 48 (46%) responses in patients previously exposed to alkylating agent therapy. Twnety-two patients had responded and 19 had failed to respond to prior alkylating agent-containing regimens; the response rates to DBD in these groups were respectively, 45 and 42%. The median time to remission was 29 days. The median time to therapeutic failure was 5.1 months for responders, 2.3 months for patients with no change, and 29 days for progressors. The combination of ADR and DBD appears to be an active and well-tolerated program in patients with previously treated metastatic breast carcinoma.

Adult↗
PubMed1976

Efficacy of selected diagnostic tests for sexually transmitted diseases.

Direct urethral and cervical smears for gonorrhea in women are useful because of their high specificity. Male rectal smears are less efficacious. Direct tests for candidiasis and trichomoniasis are also specific, but less sensitive than generally thought. Most tests exhibit only moderate month-to-month variability. No association between infection with trichomonads and gonococci was demonstrated. The gonococcal tests all perform best under conditions of high prevalence, such as those that obtain in venereal disease clinics in the United States.

Candidiasis↗
PubMed1976

Combination chemotherapy of advanced lung cancer: a randomized trial.

A controlled clinical trial comparing two-drug and three-drug combination chemotherapy was performed in 206 patients with advanced bronchogenic carcinoma, comprised of 26.2% with epidermoid carcinoma, 30.1% with small cell anaplastic carcinoma, 27.2% with adenocarcinoma, and 15.6% with large cell carcinoma. Each drug combination consisted of agents with different modes of action and included a cell-cycle-stage nonsensitive and a cell-cycle-state-sensitive agent. The overall response rate was highest for small cell carcinoma (48.2%) and adenocarcinoma (23.6%); it was less than 10% in epidermoid and large cell carcinoma. Similarly, the overall median survival was twice as long for the first two cell types (7 months) as compared with that recorded for the other two cell types (3 1/2 months). The combination of 1 (2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), cyclophosphamide, and methotrexate was shown to be statistically superior to cyclophosphamide and methotrexate with regard to objective respones rate, duration of response, and median survival for adenocarcinoma. Responders lived significantly longer than nonresponders (254 versus 90 days for small cell anaplastic carcinoma patients and 244 versus 184 days for adenocarcinoma patients). No difference in survival or objective response rate was observed between the different treatments for the other two cell types of lung cancer.

Adenocarcinoma↗
PubMed1976

[Incidence and relevance of tricuspid-valve insufficiency in acquired mitral-valve defect. Analysis based on right ventricular angiograms].

To detect tricuspid incompetence (TI) right ventricular angiography was performed in 167 patients suffering from moderate to severe mitral valve disease. Holosystolic reflux of contrast medium to the right atrium through the central part of the tricuspid valve was thought to represent true TI, whereas a jet of contrast medium following the injection catheter and originating from the region of its valve passage was assumed to reflect arteficial regurgitation. True TI was found in 35% of the total group (30% mild to moderate, 5% severe TI). TI was often accompanied by atrial fibrillation (91%), pulmonary hypertension (74%) and reduced contraction of the tricuspid annulus (55%). Since tricuspid regurgitation in mitral valve disease commonly represents "functional" incompetence surgical intervention may be recommandable only in case of severe TI or concomitant valvular stenosis.

Adult↗
PubMed1976

Lack of prognostic value of lymphoblast size in acute lymphoblastic leukaemia.

There are conflicting reports about the relationship of cell size and type to prognosis in acute lymphoblastic leukaemia (ALL). For this reason, bone marrows at diagnosis and first relapse were studied in 56 children with ALL treated on the same protocol. Lymphoblasts greater than 12 mmu in diameter were called macrolymphoblasts (MLB). Forty-one of 56 initial bone marrows had less than 20% MLB(group A), and 15 had greater than 20% MLB (group B). Median survival, complete remission rate, first remission duration, and the distribution of CNS leukaemia were similar in both groups. First relapse marrows were examined from 50 patients and a significant increase in MLB compared to initial pre-treatment bone marrows (18% vs 8%) was found.

Adolescent↗
PubMed1976

Probe for production and measurement of acute mitral regurgitant flow in dog.

A probe for production and measurement of acute mitral regurgitation in dogs is described. It consists of a tube that is introduced into the mitral valve through the left atrial appendage. Regurgitant flow through the tube is measured by an electromagnetic device. Variation of flow and zero flow are achieved by narrowing or occluding the tube with a rubber cuff. In animals weighing 30-50 kg, the probe does not produce significant mitral stenosis and the mitral leaflets fit closely around the probe during ventricular systole. The instantaneous relationship between mitral regurgitant flow (MRF) and the gradient between left ventricular and left atrial pressure shows a marked delay of MRF at the beginning and end of regurgitation. This delay can be attributed to some extent to electrical phase lag and to the small movement of the probe relative to the mitral valve during the cardiac cycle. Measurement of regurgitant stroke volume is affected by this movement only to a small extent.

Animals↗