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Biomedical subjects

R B Weiss

Publications and source records attributed to R B Weiss.

At least 127 records · Page 7Linked to original sources
PubMed1988

Fatal esorubicin-induced cardiomyopathy: report of a case and review of the literature.

A case of fatal dilated cardiomyopathy induced by esorubicin (ESO) at a total dose of 740 mg/m2, given in 27 doses over 650 days, is reported. The sudden onset, rapid clinical deterioration, and fatal outcome are detailed. The outcome was not predicted by serial rest ejection fractions or clinical signs. The data from animal studies, phase 1 and phase 2 clinical testing, are reviewed, demonstrating the almost complete absence of reports of ESO-induced cardiotoxicity. Studies reviewing ejection fractions and myocardial biopsy scores show that ESO can be cardiotoxic and may produce fatal dilated cardiomyopathy.

Cardiomyopathies↗
PubMed1988

The clinical significance of unconventional orchiectomy approaches in testicular cancer: a report from the Testicular Cancer Intergroup Study.

Despite the clear indications for an inguinal approach, reports indicate that up to 53 per cent of all testicular tumors are diagnosed or initially treated in a manner inconsistent with the classical radical orchiectomy. Of 462 evaluable patients from the Testicular Cancer Intergroup Study 47 (10.2 per cent) had undergone a nonclassical orchiectomy as the initial surgical management. This group was analyzed separately to determine the prognostic significance of needle aspiration, open biopsy, a scrotal approach and tumor contamination. Within this group of patients, those who received no adjuvant chemotherapy exhibited no increase in local or distant recurrence. While the recurrence rate similarly was not adversely affected by even gross tumor contamination, this subset underwent significantly more aggressive local surgical salvage (p less than 0.01), with scrotectomy procedures found to be of probable therapeutic value. While not to be condoned, we conclude that deviations from the classical orchiectomy, when followed by appropriate surgical management and close observation, can be of little clinical impact.

Antineoplastic Agents↗
PubMed1987

Immediate adjuvant chemotherapy versus observation with treatment at relapse in pathological stage II testicular cancer.

Between 1979 and 1984, 195 evaluable patients were entered in an international multicenter study comparing two regimens for patients with completely resected pathological Stage II testicular cancer (that is, with positive retroperitoneal lymph nodes). All patients had undergone orchiectomy and dissection of the retroperitoneal lymph nodes. They were randomly assigned to be treated with two cycles of immediate adjuvant cisplatin-based chemotherapy or to be observed monthly with treatment at relapse. The median follow-up period was four years. Of the 97 patients assigned to adjuvant chemotherapy, 6 (6 percent) had a recurrence; however, only 1 had received adjuvant chemotherapy before the recurrence. Three died (one of testicular cancer), and 94 of the 97 survived. Of the 98 patients who were observed, 48 (49 percent) had a relapse. However, almost all patients with relapses were effectively treated, and 93 of the 98 are alive and disease-free; 3 have died of testicular cancer. No identifiable factors were strongly associated with the risk of relapse. We conclude that two courses of cisplatin-based adjuvant chemotherapy will almost always prevent relapse in pathological Stage II testicular cancer treated with orchiectomy and retroperitoneal-lymph-node dissection. However, when surgery, follow-up, and chemotherapy are optimal, observation with chemotherapy only for relapse will lead to equivalent cure rates.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Hypersensitivity reactions from antineoplastic agents.

Antitumor drugs, like any other therapeutic agent, have the ability to incite hypersensitivity reactions. Certain of such drugs (e.g., L-asparaginase and taxol) cause reactions with great enough frequency to be a major impediment to repetitive use of the drug. Very few antitumor drugs have not had at least one reported instance of causing a hypersensitivity reaction. Most reactions are of the type I category in the Gell and Coombs classification, but there also are instances of types II, III, and IV reactions caused by many of the antineoplastic agents. The mechanisms of such reactions have been poorly evaluated in many reports. In analyzing a hypersensitivity reaction in a patient being treated for cancer, one should document that the antitumor drug is indeed the offender, and not an ancillary drug or a formulation product that is being used. There are many tests that evaluate the source and mechanism of hypersensitivity reactions. This article reviews the current information on hypersensitivity reactions to antineoplastic drugs and provides a logical approach for their assessment.

Antineoplastic Agents↗
PubMed1987

Adjuvant chemotherapy after conservative surgery plus irradiation versus modified radical mastectomy. Analysis of drug dosing and toxicity.

In a cohort of 764 evaluable patients with primary breast cancer, we have compared the ability to deliver full doses of adjuvant chemotherapy in two patient groups: one undergoing conservative breast surgery plus irradiation and the other having modified radical mastectomy as primary treatment for the cancer. We have also analyzed the toxicities of the concurrent radiation and chemotherapy. The group having irradiation had significantly more moderate leucopenia, which caused a short delay (median, three weeks) in the overall time necessary to complete the planned chemotherapy. However, among those patients who completed the planned chemotherapy cycles, the fraction who received more than 85 percent average drug doses was 96 percent or higher in all but one small subgroup. Interaction between the irradiation and chemotherapy caused mild breast skin reactions in 42 percent of patients so analyzed and worse reactions in 12 percent. When follow-up tracings were performed, mild electrocardiogram abnormalities occurred in 19 percent of patients, apparently because of the irradiation. We conclude that intravenous adjuvant chemotherapy, as administered in this study, can be delivered as intensely with conservative primary treatment as after mastectomy and that toxicity is mild, rarely requiring intervention or treatment discontinuation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Photoalkylated DNA and ultraviolet-irradiated DNA are incised at cytosines by endonuclease III.

Photoalkylation, the ultraviolet irradiation of DNA with isopropanol and di-tert-butylperoxide, causes a variety of base alterations. These include 8-(2-hydroxy-2-propyl)guanines, 8-(2-hydroxy-2-propyl)adenines and thymine dimers. An E. coli endonuclease against photoalkylated DNA was assayed by conversion of superhelical PM2 phage DNA to the nicked form. Enzyme activities were compared between extracts of strain BW9109 (xth-), lacking exonuclease III activity, and strain BW434 (xth-,nth-), deficient in both exonuclease III and endonuclease III. The endonuclease level in the double mutant against substrate photoalkylated DNA was under 20% of the activity in the mutant lacking only exonuclease III. Irradiation of the DNA substrate in the absence of isopropanol did not affect the activity in either strain. Analysis by polyacrylamide gel electrophoresis identified the sites of DNA cleavage by purified E. coli endonuclease III as cytosines, both in DNA irradiated at biologically significant wavelengths and in photoalkylated DNA. Neither 8-(2-hydroxy-2-propyl)purines, pyrimidine dimers, uracils nor 6-4'-(pyrimidin-2'-one)pyrimidines were substrates for the enzyme.

Alkylation↗
PubMed1986

Skin reactions induced by trimetrexate, an analog of methotrexate.

We have observed three forms of skin toxicity induced by the new antifol trimetrexate in a Phase I trial. They are: radiation recall, cellulitis at the infusion site, and generalized skin eruptions with erythroderma. A total of 25 episodes of some form of skin reaction occurred in 31 patients. The generalized eruption began about four days after drug administration and cleared within a week. The mechanism of skin toxicity of trimetrexate and other antifols is unknown.

Cellulitis↗
PubMed1986

Malignant lymphoma of the testis.

Malignant lymphomas of the testis account for approximately 5 percent of testicular neoplasms, and they are the most common testicular malignancy between the ages of 60 and 80. Testicular lymphoma has a propensity to be associated with involvement of the skin, the central nervous system, Waldeyer's ring and adjacent structures, and the contralateral testicle. In general, essentially all patients with testicular lymphoma have been categorized as having "poor-risk" non-Hodgkin's lymphoma, with diffuse histiocytic lymphoma being the most common histologic subtype. All patients with testicular lymphoma should be treated with aggressive combination chemotherapy, with or without radiotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Frameshift suppression in aminoacyl-tRNA limited cells.

Under certain conditions aminoacyl-tRNA limitation can phenotypically suppress frameshift alleles. The observed suppression is due to an increase in abnormal translocation of ribosomes translating codons that have a short supply of aminoacyl-tRNA. The rIIB frameshift alleles of bacteriophage T4 are used here to pinpoint the sites of ribosome frameshifting caused by these hypothetical decoding errors. The data indicate that not all hungry codons are associated with abnormal translocation, only a relatively small subset. Analysis of the hungry codons which are associated with ribosome frameshifting points to the existence of severe context effects determining the shiftiness of these codons.

Alleles↗
PubMed1986

Hyperglycemic complications associated with adjuvant chemotherapy of breast cancer. A cancer and leukemia group B (CALGB) study.

Many adjuvant chemotherapy regimens used for breast cancer include prednisone, which has the potential to cause hyperglycemia. We reviewed the results of three CALGB studies employing prednisone as part of adjuvant therapy to determine the incidence and severity of hyperglycemic complications. All treatment regimens included cyclophosphamide, methotrexate or doxorubicin, 5-fluorouracil, and vincristine in addition to prednisone. Among 1,237 evaluable patients receiving a five-drug regimen including prednisone, there were 98 patients (7.9%) who experienced any degree of hyperglycemia. Thirty patients (2.4% overall; 30.6% of those having any hyperglycemia) had severe or life-threatening degrees of hyperglycemia, including two patients whose hyperglycemia contributed directly to death. We conclude that prednisone administration as part of adjuvant chemotherapy regimens in breast cancer produces an appreciable incidence of hyperglycemia. Serum glucose levels should be monitored during therapy to help prevent the occasional severe or life-threatening episode of hyperglycemia in these patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Amsacrine-associated cardiotoxicity: an analysis of 82 cases.

Amsacrine is an antileukemia drug being widely used in North America, Europe, Australia, and New Zealand. In the initial clinical trials, patients treated with amsacrine developed occasional instances of acute cardiac arrhythmias and cardiomyopathy. We review and analyze the features of cardiac abnormalities associated with amsacrine in 82 patients, 27 of whom have not been previously reported. The rest have been reported in the literature, but we have included a large amount of additional information about these patients in our analysis. We conclude that amsacrine-related cardiac events are less common than those related to anthracycline chemotherapeutic agents. Manifestations of such toxicity include ECG abnormalities, ventricular and atrial arrhythmias, sudden death, and congestive heart failure. There is little or no cumulative dose effect. Hypokalemia may be a risk factor for development of serious tachyarrhythmias, but such problems can occur despite a normal serum potassium level. Amsacrine appears to affect depolarization and repolarization of the heart, but the mechanism is unknown.

Adolescent↗