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Biomedical subjects

J Crowley

Publications and source records attributed to J Crowley.

At least 55 records · Page 3Linked to original sources
PubMed1996

Evaluation of race as a prognostic factor in multiple myeloma. An ancillary of Southwest Oncology Group Study 8229.

PURPOSE: The objective of this investigation was to assess the impact of race (black v white) on the survival of patients with multiple myeloma treated within the context of a large clinical trial. PATIENTS AND METHODS: A cohort of patients randomized to receive one of two treatment regimens and monitored for at least 10 years was studied to assess the impact of race as a prognostic factor, after adjusting for other known factors such as stage of disease. Patients were recruited from the referral network of the Southwest Oncology Group (SWOG), a national multiinstitutional consortium that includes both academic and community treatment centers. Patients had a diagnosis of multiple myeloma and had not previously been treated for this disease. They were carefully characterized as to demographic and clinical features, and were randomized to receive one of two treatment regimens, which proved to have virtually identical outcomes. The outcome measure was survival, measured from the date of randomization to the date of last contact. Patients still alive at last contact date were treated as censored observation. RESULTS: Survival for black myeloma patients was similar to that for white patients, both overall and adjusted for prognostic factors such as stage. CONCLUSION: Observed differences in mortality between blacks and whites cannot be attributed to differences in survival after diagnosis, given comparable treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Peripheral blood stem cell transplants for multiple myeloma: identification of favorable variables for rapid engraftment in 225 patients.

Transfusion of autologous peripheral blood stem cells (PBSCs) of good quality ensures fast hematopoietic engraftment after myeloablative therapy with a decrease in procedure-related morbidity and mortality. We have analyzed variables influencing the kinetics of engraftment, and therefore reflecting the quality of PBSC collections, in 225 patients with newly diagnosed or refractory multiple myeloma (MM) who received an autotransplant in support of high dose melphalan (200 mg/m2); 132 of these patients also completed a second transplant. All PBSCs were collected before the first transplant after high-dose cyclophosphamide (6 g/m2) and hematopoietic growth factors, mainly granulocyte-macrophage colony-stimulating factor. PBSCs were administered either alone (91 patients) or with bone marrow (134 patients). A highly significant correlation was observed between the number of CD34+ cells per kilogram infused and prompt recovery of both granulocytes (P = .0001) and platelets (P = .0001). After correction for the proportion of patients with > or = 2 x 10(6)/kg CD34 PBSCs infused and with < or = 12 months of prior therapy, no difference in engraftment kinetics was seen between patients receiving PBSCs only and those also receiving bone marrow. Exposure to chemotherapy, even to < or = 6 months of alkylating agents, significantly delayed hematopoietic recovery posttransplantation. The threshold dose of CD34 cells necessary for prompt engraftment was > or = 2.0 x 10(6)/kg for patients with < or = 24 months of chemotherapy before the first transplant, whereas greater than 5 x 10(6)/kg CD34 cells were required to assure rapid recovery also in those with longer exposure. Such quantities, easily collected in the large majority of patients with shorter exposure (91%), were obtained in only 28% of patients with more than 24 months of prior chemotherapy. Rapid platelet recovery within a narrow range of time (before day 14) was almost invariably seen (94%) when greater than 5 x 10(6)/kg CD34 cells were infused, irrespective of the duration of prior therapy, whereas the range widened progressively when less CD34 cells were infused. In the absence of CD34 measurements, fast recovery of platelets to greater than 50 x 10(9)/L within 14 days after high-dose cyclophosphamide and < or = 12 months of prior chemotherapy were the best predictors of early engraftment. Prudent use of stem cell-damaging agents, such as melphalan and nitrosoureas, is recommended in MM patients who might be candidates for autotransplantation. Alternatively, PBSCs should be collected early after diagnosis.

Adult↗
PubMed1995

Design of the Prostate Cancer Prevention Trial (PCPT).

The PCPT is a chemoprevention trial of finasteride with a primary endpoint of biopsy-proven presence or absence of prostate cancer. A total of 18,000 healthy men, aged 55 years and older, will be randomized. Half will receive finasteride (5 mg/day) and half will receive placebo (one matching tablet per day) for 7 years. The trial is designed to have 92% power to detect a 25% reduction in period prevalence of biopsy-proven disease using a two-sided test with alpha = 0.05. The trial is complicated by the known impact of finasteride on the major screening test for prostate cancer, prostate specific antigen (PSA). This paper describes the PCPT design with reference to alternatives that were considered. The chosen design depends on five critical assumptions that must be monitored closely throughout the 9-year trial.

Aged↗
PubMed1995

Chemoradiotherapy with or without granulocyte-macrophage colony-stimulating factor in the treatment of limited-stage small-cell lung cancer: a prospective phase III randomized study of the Southwest Oncology Group.

PURPOSE: This phase III randomized trial was designed to determine if granulocyte-macrophage colony-stimulating factor (GM-CSF) reduces the hematologic toxicity and morbidity induced by chemoradiotherapy in limited-stage small-cell lung cancer (SCLC). METHODS: This multicenter prospective trial randomized 230 patients to receive chemotherapy and radiotherapy (RT) with or without GM-CSF given on days 4 to 18 of each of six cycles. The primary end point was hematologic toxicity. Secondary end points included the following: nonhematologic toxicities; days of (1) fever, (2) antibiotics, (3) hospitalization, and (4) infection; number of transfusions; drug doses delivered; and response rates and survival. RESULTS: There was a statistically significant increase in the frequency and duration of life-threatening thrombocytopenia (P < .001) in patients randomized to GM-CSF. GM-CSF patients had significantly more toxic deaths (P < .01), more nonhematologic toxicities, more days in hospital, a higher incidence of intravenous (IV) antibiotic usage, and more transfusions. Patients randomized to GM-CSF had higher WBC and neutrophil nadirs (P < .01), but no significant difference in the frequency of grade 4 leukopenia or neutropenia. Patients randomized to GM-CSF had a lower complete response rate (36% v 44%), but the differences were not significant (P = .29). There were no significant differences in survival (median, 14 months on GM-CSF and 17 months on no GM-CSF; P = .15). CONCLUSION: GM-CSF, as delivered in this study, should not be included with concurrent chemoradiotherapy treatment programs for limited-stage SCLC. The simultaneous use of hematopoietic colony-stimulating factors (CSFs) and chemoradiotherapy should be performed only in experimental settings. Chemoradiotherapy programs with cisplatin and etoposide ([VP-16] PE) and simultaneous chest RT produce grade 4 neutropenia and thrombocytopenia in a small-enough proportion of patients that prophylactic hematopoietic growth factors are clinically unnecessary.

Adult↗
PubMed1995

Effects of methylphenidate in HIV-related depression: a comparative trial with desipramine.

This report is a randomized, double-blind, comparative trial of desipramine with the psychomotor stimulant methylphenidate. Twenty HIV antibody-positive patients with depressive symptoms were randomly assigned to either drug. After individual dose titration, the mean daily dose of desipramine was 150 mg. and methylphenidate 30 mg. daily. The differences in responses between desipramine and methylphenidate were not statistically significant on various measures of depression. The antidepressant effect of methylphenidate did not occur any faster than that of desipramine. Both significantly reduced depressive and anxious symptomatology over the blinded portion of the treatments. Thus, methylphenidate relieves depressive symptomatology with efficacy similar to that of desipramine, offering an alternative to patients who are unable to tolerate standard tricyclic antidepressant therapy. The dopaminergic effects of methylphenidate are likely to mediate its antidepressant effects.

Adult↗
PubMed1995

Coronary artery bypass grafting in an achondroplastic dwarf.

To our knowledge, coronary bypass for complications of coronary artery disease in achondroplasia has not previously been described. Achondroplasia, in and of itself, is not a contraindication to coronary bypass. Although the anatomic reserve of saphenous vein is less in achondroplastic dwarfs than in people of normal stature, that vessel and the internal mammary artery can be harvested in routine fashion. A 60-year-old woman with several risk factors for coronary artery disease underwent successful bypass surgery, which included the use of both a saphenous vein and the left internal mammary artery.

Achondroplasia↗
PubMed1995

Relapse of multiple myeloma after autologous transplantation: survival after salvage therapy.

Owing to lack of progress with standard chemotherapy and the presence of a dose response effect for alkylating agents, autotransplantation is performed with increasing frequency for multiple myeloma (MM). However, sustained relapse-free survival is still infrequent. We studied 94 patients who had relapsed following autotransplantation, in order to evaluate the efficacy of further therapy. Post-transplant salvage treatment consisted of either standard dose therapy (53) or transplantation with an intensive preparative regimen (with autograft support in 31 and allogeneic transplantation in 10). Complete remission (CR) rate, event-free and overall survival were assessed and prognostic variables identified in a multivariate regression analysis. With a median follow-up of 11 months, the projected overall survival at 18 months for all patients is 59%. A multivariate analysis identified pre-salvage beta-2-microglobulin (B2M) < or = 2.5 mg/l (P = 0.0002) and late relapse after the preceding transplant ( > 12 months; (P = 0.02) as independent significant favorable variables for overall survival. By combining pre-salvage B2M and the time to relapse, 2 risk groups of patients could be identified with significantly different overall survival: those with at least one favorable variable had a projected survival at 18 months of 79%, compared to 38% for patients with no favorable variable. Transplantation performed as primary salvage therapy was associated with a significantly prolonged survival (P = 0.009), although this may be more a reflection of the way salvage therapy was selected.

Follow-Up Studies↗
PubMed1995

An implicitly defined parametric model for censored survival data and covariates.

Parametric survival functions are usually defined as explicit functions of time and covariates. However, consideration of some simple differential equations describing certain survival curves leads to a descriptive equation which cannot be explicitly solved for the survival function. Nevertheless, the resulting survival function has useful properties: it is a hybrid between the exponential and uniform distributions, it can be used computationally in the same fashion as other survival models, and the effect of covariates on model parameters can be incorporated in a straightforward manner. The derivation and an example of the use of this model are provided.

Alkylating Agents↗
PubMed1995

The changing pattern of employment in nursing.

A competitive and changing society places pressure on employers. Increasing flexibility, as well as added value, is expected from employees. Nurses need a strategy to survive, plus a wide range of skills.

Adaptation, Psychological↗
PubMed1994

Defective measles virus in human subacute sclerosing panencephalitis brain.

Evidence is presented showing that the brain cells of patients with subacute sclerosing panencephalitis (SSPE) contain mutant measles (MV) genomes having the characteristics of 5' copy-back defective interfering (DI) RNAs. Using a polymerase chain reaction-based amplification specific for copy-back DIs, abundant, discrete cDNAs representing different-sized MV defective RNA species were generated from each SSPE brain. The defective genomes were cloned in two portions. The most common of these defective species were sequenced, confirming their MV genome origin and 5' copy-back nature. We deduced that the minimum DI stem length of these species was 95 nucleotides, further delimiting the prerequisite 5' regulatory region sequences specifying MV genomic replication/encapsidation functions. This calculation assumes a precise copy-back mechanism and complete complementarity of the panhandle structure. Since the SSPE-derived viral genome encodes dysfunctional viral envelope proteins, we hypothesize that SSPE brains may lack the high degree of selective pressure encountered in tissue culture MV infections. This allows for the coexistence of numerous replication-competent defective particles in each SSPE brain. A role for viral defective particles as modulators of this persistent measles virus infection of humans is proposed.

Base Sequence↗
PubMed1994

High-dose therapy for refractory multiple myeloma: improved prognosis with better supportive care and double transplants.

One hundred and thirty-five patients with advanced and refractory myeloma received one of three high-dose therapy regimens: melphalan at doses of 90 to 100 mg/m2 (MEL 100; 47 patients) without autotransplant; total body irradiation (TBI; 850 cGy) with either melphalan 140 mg/m2 or thiotepa 750 mg/m2 and autologous bone marrow transplant (ABMT) (< or = 30% plasma cells; 21 patients); melphalan 200 mg/m2 (MEL 200) supported by both peripheral blood stem cells (PBSC) and ABMT plus GM-CSF intended as a double-transplant program (67 patients; 42 have completed and 3 are still awaiting a second autotransplant; 5 additional patients received an allograft for their second transplant). Mortality within 2 months of therapy was 20% to 25% with MEL 100 and TBI regimens, but less than 1% with MEL 200, mainly because severe neutropenia (< 500/microL) was shortened to less than 1 week due to infusion of PBSC and use of growth factor therapy. Low beta 2-microglobulin (beta 2M) levels < or = 2.5 mg/L and MEL 200 therapy were identified as the two most important independent favorable variables associated with prolonged event-free survival (EFS) and overall survival (OS). On the basis of these two parameters, three risk groups were defined: 29 good-risk patients with low beta 2M receiving MEL 200 had the best outcome, with median durations of EFS of 37 months and projected OS of > or = 43 months; 54 intermediate-risk patients displaying one of the two favorable parameters had EFS and OS durations of 16 and 36 months, respectively; and 52 poor-risk patients with high beta 2M not receiving MEL 200 had a dismal prognosis, with EFS of 3 months and OS of 5 months (all P < .0001). Further analysis that excluded treatment as a variable identified high beta 2M and resistant relapse as the two major adverse prognostic factors, one of which was present in 80% of the 135 patients. Among these 108 high-risk patients, prognosis was improved markedly with MEL 200 because of both better supportive care (PBSC and hematopoietic growth factors) and more intensive therapy using the double-transplant approach. This study supports the concept that safer and potentially more-effective therapies can be developed in the setting of advanced and resistant disease.

Age Factors↗
PubMed1994

Phase II study of carboplatin (CBDCA) in refractory multiple myeloma. A Southwest Oncology Group study.

Nineteen patients with multiple myeloma resistant to standard alkylating agent therapy or to the VAD regimen received carboplatin at a planned daily dose of 100 mg/M2 on four successive days. Two patients erroneously received a four-fold higher drug dose resulting in bone marrow aplasia and death without antitumor effect in one patient with post-mortem examination. No anti-tumor effect was observed among 15 patients evaluable for response (two lacked follow-up examination of tumor markers). Major toxicities were hematologic and included grade > or = III, leukopenia in 9, thrombocytopenia in 6 and anemia in 3 of the 17 evaluable patients. Their median survival was 9 months. These results indicate that carboplatin is inactive in refractory multiple myeloma.

Adult↗
PubMed1994

Hemopoietic stem cell transplants for multiple myeloma.

Recently, high-dose therapy has been evaluated in patients with multiple myeloma, mainly with autologous transplant support. As a result of rapid hemopoietic engraftment with peripheral blood stem cells collected after chemotherapy and/or hemopoietic growth factor priming, procedure-related mortality has dropped to below 5%. When applied within 12 months from initial therapy, autologous transplants effect complete remissions in up to 50% of patients, with median event-free and overall survival durations on the order of 2.5 and 4 to 5 years, respectively. Complete response rates with allogeneic transplantation range from 30% to 50%, and procedure-related mortality is approximately 40%. Although the median durations of event-free and overall survival are shorter with allogeneic transplants, approximately 35% to 40% of patients survive with minimal disease for at least 5 to 6 years. Direct comparisons of standard therapy and autologous transplants have just begun.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

The role of cysteine residues 129 and 329 in Escherichia coli K1 CMP-NeuAc synthase.

N-Acetylneuraminic acid cytidyltransferase (CMP-NeuAc synthase) of Escherichia coli K1 is sensitive to mercurials and has cysteine residues only at positions 129 and 329. The role of these residues in the catalytic activity and structure of the protein has been investigated by site-directed mutagenesis and chemical modification. The enzyme is inactivated by the thiol-specific reagent dithiodipyridine. Inactivation by this reagent is decreased in the presence of the nucleotide substrate CTP, suggesting that a thiol residue is at or near the active site. Site-directed mutagenesis of either residue Cys-129 to serine or Cys-329 to selected amino acids has minor effects on the specific activity of the enzyme, suggesting that cysteine is not essential for catalysis and that a disulphide bond is not an essential structural component. The limited reactivity of the enzyme to other thiol-blocking reagents suggests that its cysteine residues are partially exposed. The accessibility and role of the cysteine residues in enzyme structure were investigated by fluorescence, c.d. and denaturation studies of wild-type and mutant enzymes. The mutation of Cys-129 to serine makes the enzyme more sensitive to heat and chemical denaturation, but does not cause gross changes in the protein structure as judged by the c.d. spectrum. The mutant containing Ser-129 instead of Cys-129 had a complex denaturation pathway similar to that of wild-type E. coli K1 CMP-NeuAc synthase consisting of several partially denatured states. Cys-329 reacts more readily with N-[14C]ethylmaleimide when the enzyme is in a heat-induced relaxed state. Cys-129 is less reactive and is probably a buried residue.

Base Sequence↗
PubMed1993

Data monitoring committees for Southwest Oncology Group clinical trials.

A monitoring committee policy was established by the Southwest Oncology Group in 1985 to address documented problems in study conduct. Committees consisting of the study coordinators, disease committee chair, study statistician, Group chair, Group statistician, an uninvolved Southwest Oncology Group clinician, an NCI representative, and a representative from each involved group for intergroup studies have been appointed for each phase III study. Business is conducted largely through the mail and through conference calls. Since then, problems identified in older studies have been largely resolved. Appropriate and timely decisions are being made at modest additional expense to the Group.

Clinical Trials as Topic↗
PubMed1993

Phase II trial of 6-thioguanine administered as 120 hour continuous infusion for refractory or recurrent small cell lung cancer. A Southwest Oncology Group study.

Nineteen eligible patients with recurrent small cell lung cancer were treated with a 120 hour continuous infusion of 6-thioguanine at a starting dose of 35 mg/m2/day. There were no responses in these 19 patients. Toxicity was acceptable with the primary toxicity being hematologic. Based on this trial, 6-thioguanine is not felt to have significant antitumor activity in this patient population.

Aged↗