Search PubMed⌕ Search

Biomedical subjects

R B Weiss

Publications and source records attributed to R B Weiss.

At least 91 records · Page 5Linked to original sources
PubMed1991

Staging relationships and outcome in early stage testicular cancer: a report from the Testicular Cancer Intergroup Study.

The Testicular Cancer Center Intergroup Study entered surgically staged patients with nonseminomatous tumor and metastases limited to the regional lymph nodes into a previously reported cooperative trial of immediate versus delayed therapy for positive retroperitoneal node disease. Patients with negative nodes (stage I) were placed in an observation registry with specified treatment strategy upon relapse. Of 264 stage I cancer patients 27 (10.2%) had recurrence: 5 of these 27 patients died after recurrence of the testicular malignancies, while 4 other nontumor-related deaths have occurred. Pre-lymphadenectomy staging characteristics observed to predict significantly node positivity are the results of radiological examinations, presence of tumor invasion, vascular invasion and tumor histology. In a multiple logistic regression analysis with these variables, misclassification still occurs in more than a fourth of the patients. Future refinements in diagnosis may allow for better prediction of these patients at risk to have positive lymph nodes and ultimately recurrence. Presently, if assessment of nodal involvement is the objective, noninvasive procedures are not an adequate substitute for surgical staging with modified lymphadenectomy.

Adult↗
PubMed1991

Cytarabine and neurologic toxicity.

Cytarabine is an effective drug in the treatment of certain hematologic malignancies and its common toxicities are myelosuppression and gastrointestinal disturbance. In the past decade, neurotoxicity has been an increasingly recognized cytarabine effect. Intrathecal (IT) cytarabine may result in myelopathy that is incompletely reversible. Combined IT drug and cranial irradiation may lead to necrotizing leukoencephalopathy. Intravenous (IV) therapy may cause a peripheral neuropathy that varies greatly in its severity. The high IV cytarabine doses now commonly used can cause seizures, cerebral dysfunction, or an acute cerebellar syndrome with an incidence up to 14%. Patient age (greater than 60 years) appears to be the most important risk factor, but drug dose/schedule, cumulative drug dose, renal and hepatic dysfunction, and concomitant use of neurotropic antiemetic agents may also influence the risk of neurotoxicity. A better understanding of the pathophysiology and pharmacology of such cytarabine-induced neuronal injury will allow this drug to be used with greater efficacy and safety.

Central Nervous System Diseases↗
PubMed1991

Prediction of prognosis in primary breast cancer by detection of a high molecular weight mucin-like antigen using monoclonal antibodies DF3, F36/22, and CU18: a Cancer and Leukemia Group B study.

Three monoclonal antibodies (MAbs) (DF3, F36/22, CU18) were used to monitor expression of distinct epitopes present within a family of mucin-like, breast carcinoma-associated molecules. Primary tumor specimens from more than 190 stage II breast cancer patients were evaluated for expression of the high molecular weight antigens. With a median follow-up of 6 years, patients whose tumors exhibited high immunoperoxidase staining scores (greater than 50% positive cells) with MAb DF3 had a superior disease-free survival ([DFS] 56% +/- 6% v 37% +/- 5% at 6 years; P = .0088) and overall survival ([OS] 72% +/- 5% v 59% +/- 5% at 6 years; P = .025). Staining scores with the other two antibodies did not correlate with improved prognosis. For MAbs DF3 and CU18, patients whose tumors exhibited predominantly apical cellular reactivity patterns had improved DFS, although differences reached conventional levels of statistical significance only with MAb CU18. In multivariate analyses, the prognostic value of MAb DF3 staining was independent of other identified prognostic factors. Furthermore, the concordance between primary and axillary lymph node metastases staining with each MAb was 73%, 80%, and 85% for MAbs DF3, F36/22, and CU18, respectively. These results suggest that staining with MAb DF3 identifies a group of node-positive women with a relatively favorable prognosis. Expression of the DF3 mucin-like glycoprotein is related to better differentiation, and staining with MAb DF3 provides an accurate and objective estimate of clinical outcome independent of histopathologic evaluation.

Adult↗
PubMed1991

Ifosfamide vs cyclophosphamide in cancer therapy.

Ifosfamide is a newly available analog of cyclophosphamide in the oxazaphosphorine drug class. Cyclophosphamide has been marketed for 32 years, and it remains a highly effective agent for a wide cross-section of malignancies. Ifosfamide has a similar spectrum of antitumor activity but has different pharmacokinetics that could provide advantages in efficacy. Although ifosfamide has been substituted for cyclophosphamide in many therapeutic regimens, it has not been proven superior to cyclophosphamide in any cancer. Its current use in non-investigational therapy is for metastatic testicular carcinoma and sarcomas. Ifosfamide has a disadvantageous toxicity spectrum compared to cyclophosphamide and a greater financial cost and cost of patient inconvenience for administration. For most malignancies responsive to an oxazaphosphorine, the analog of choice will remain cyclophosphamide.

Carcinoma, Non-Small-Cell Lung↗
PubMed1991

Phase III trial of brief intensive treatment of adult acute lymphocytic leukemia comparing daunorubicin and mitoxantrone: a CALGB Study.

This paper reports a study of the Cancer and Leukemia Group B (CALGB) comparing daunorubicin (DNR) or mitoxantrone (DHAD) in induction followed by multidrug intensification over 8 months in adult patients with acute lymphocytic leukemia (ALL). A total of 164 newly diagnosed patients were randomly assigned to either DNR or DHAD plus vincristine, prednisone and methotrexate given intravenously (i.v.) and interthecally (i.t.). Patients received four more intensification courses of chemotherapy and then all therapy was stopped. Central nervous system (CNS) prophylaxis consisted of nine infusions of intermediate dose methotrexate (MTX) and intrathecal MTX. DHAD and DNR were equally effective in producing complete remissions (63 and 65%, respectively). The estimated median remission duration is 10.2 and 12.3 months for the DHAD and DNR arms, respectively (p = 0.56). This study was stopped earlier than planned when it became apparent that remission duration for both arms was shorter than seen in our prior study in which all patients received more than 1 year of maintenance therapy. The estimated median survival is 18.3 and 20.6 months for the DHAD and DNR arms, respectively (p = 0.90). Younger patients and patients with a pre-treatment white blood count of less than 30,000/microliters had a significantly longer remission duration and survival. Eleven per cent of patients who achieved a complete remission have had a CNS relapse to date, which is not different from the rate in our prior study using cranial irradiation and i.t. MTX, implying that intermediate dose MTX with i.t. MTX may be as effective as cranial irradiation and i.t. MTX. This study suggests that some form of maintenance chemotherapy is required for the eradication of residual leukemia cells.

Adolescent↗
PubMed1990

A nascent peptide is required for ribosomal bypass of the coding gap in bacteriophage T4 gene 60.

Bacteriophage T4 DNA topoisomerase gene 60 contains a 50 nucleotide untranslated region within the coding sequence of its mRNA. Translational bypass of this sequence by elongating ribosomes has been postulated for the mode of synthesis of an 18 kd polypeptide specified by the split coding segments. Ribosome bypass of the untranslated region also occurs when a segment of gene 60 is fused to lacZ and expressed in E. coli. The efficiency of bypass in these gene 60-lacZ fusions approaches 100%. Here, mutations that delete, insert, or substitute nucleotides from gene 60-lacZ fusions are examined. Essential features necessary for high level gap bypass emerging from this analysis are a cis-acting nascent peptide sequence, a short duplication bordering the gap, and a stop codon contained in a stem-loop structure at the 5' junction of the gap.

Amino Acid Sequence↗
PubMed1990

Transcriptional slippage occurs during elongation at runs of adenine or thymine in Escherichia coli.

A run of 11 adenine or thymine residues at the 5' end of an out-of-frame lacZ gene causes a high level of beta-galactosidase expression in E. coli. This effect was not observed for a run of guanine residues. Reverse transcription of mRNA isolated from E. coli containing the run of 11 A's reveals heterogeneity of transcript length while reverse transcription of mRNA isolated from S. cerevisiae containing the same gene shows no heterogeneity. Protein sequencing of the beta-galactosidase molecules derived from the out-of-frame construct containing a run of adenines reveals the addition of a lysine at the run. A new method was developed where messages small enough to allow resolution of single nucleotide differences on an acrylamide gel are electrophoresed, electroblotted onto nylon and probed. This confirmed the reverse transcription results and showed that additional residues can be added to transcripts derived from DNA containing 10 or 11 thymine residues. A mechanism for slippage is discussed where the A-U rich RNA-DNA hybrid can denature during elongation and rehybridize in an offset position, causing the addition of extra residues to the transcript.

Adenine↗
PubMed1990

Interstitial pneumonitis associated with ifosfamide therapy.

Ifosfamide and cyclophosphamide have many toxicities in common. Interstitial pneumonitis has not been reported previously as a side effect of ifosfamide therapy. The authors report the case of a 58-year-old woman who was treated with ifosfamide for soft tissue sarcoma. After the fifth cycle of chemotherapy she developed clinical evidence of interstitial pneumonitis, a diagnosis that was later confirmed at autopsy. The authors suggest that ifosfamide therapy was directly related to this patient's fatal case of interstitial pneumonitis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

A phase I and pharmacokinetic study of trimetrexate using a 24-hour continuous-injection schedule.

Trimetrexate (TMTX) is an analog of methotrexate and a potent inhibitor of the enzyme dihydrofolate reductase. In this phase I study, TMTX was given intravenously to 32 patients as a constant infusion over 24 hours every 28 days. The maximum-tolerated dose of TMTX was 200 mg/m2, with myelosuppression as the dose-limiting toxicity. Other toxicities included nausea and vomiting, stomatitis, erythema and phlebitis at the site of infusion, rash and skin hyperpigmentation, and elevated serum hepatic enzymes. Two drug-related deaths occurred secondary to leukopenia and sepsis. Twenty-six patients were evaluable for antitumor response. Twenty-one patients had progressive disease, while three patients had disease stabilization. There were two partial responses observed--one in a patient with breast cancer and a second in a patient with nasopharyngeal carcinoma. TMTX pharmacokinetics were studied in 15 patients. The drug had a mean terminal half-life of 13 hours. Steady-state was not achieved during the 24-hour infusions. Only 6% of the parent compound was excreted unchanged in the urine, and CSF levels averaged less than 2% of simultaneously measured plasma levels. A dose of 150 mg/m2 is recommended for phase II trials of TMTX using this 24-hour infusion schedule.

Adult↗
PubMed1990

Clinical cardiotoxicity of esorubicin (4'-deoxydoxorubicin,DxDx): prospective studies with serial gated heart scans and reports of selected cases. A Cancer and Leukemia Group B report.

Esorubicin (4'-deoxydoxorubicin, DxDx) has undergone extensive Phase II investigation for the treatment of cancer. Based on in vitro and animal data, esorubicin may possess less myocardial toxicity when compared to doxorubicin. One hundred thirty-six patients with histologically or cytologically documented non-small cell lung cancer or advanced breast cancer were enrolled in two concurrent CALGB clinical trials using esorubicin at a dose of 30 mg/m2 administered intravenously every 21 days. No patient had previously received an anthracycline agent or had evidence of severe cardiovascular disease. Cardiotoxicity was observed in eleven patients. Four patients developed symptoms of congestive heart failure and three asymptomatic patients had a significant fall in left ventricular ejection fraction (LVEF) as measured by gated pool heart scan. Four patients had cardiac signs or symptoms of indeterminate relationship to esorubicin therapy. Of 44 patients receiving more than four cycles of therapy, 36 patients (82%) had serial gated pool heart scans permitting assessment of subclinical myocardial toxicity. A 5% drop in LVEF was observed following approximately 240 mg/m2 esorubicin; a 10% drop was observed after approximately 480 mg/m2. If further clinical studies are undertaken with esorubicin, investigators are advised to monitor cardiac function frequently once the cumulative esorubicin dose exceeds 240 mg/m2. If congestive failure appears during therapy, prompt cessation of esorubicin and institution of inotropic agents may provide effective palliation. Normal myocardial function may be restored within several months.

Adult↗
PubMed1990

Identification and characterization of transcripts from the neurofibromatosis 1 region: the sequence and genomic structure of EVI2 and mapping of other transcripts.

Mapping of the EVI2 gene between the translocation breakpoints of two patients with neurofibromatosis type 1 (NF1), combined with the likely role of its murine homolog in neoplastic disease, implicates EVI2 as a possible candidate for the NF1 gene. We report here the expression of a 1.6-kb EVI2 transcript in normal human brain and peripheral blood mononuclear cells. Sequencing studies predict an EVI2 protein of 232 amino acids that contains an N-terminal signal peptide, an extracellular domain with five potential glycosylation sites, a single hydrophobic transmembrane domain with a leucine zipper, and a hydrophilic cytoplasmic domain. These features are all well-conserved with respect to the mouse Evi-2 protein and are consistent with the hypothesis that EVI2 is a membrane protein that may complex with itself and/or other proteins within the membrane, perhaps to function as part of a cell-surface receptor. In the course of these studies we have also identified three other transcripts (classes of cDNAs) from the NF1 region. Two of these transcripts map between the NF1 translocation breakpoints; the remaining transcript maps just outside this region.

Amino Acid Sequence↗
PubMed1990

Hypersensitivity reactions from taxol.

Taxol is an antitumor agent in clinical trial that has been shown to have activity against advanced ovarian carcinoma and melanoma. Hypersensitivity reactions (HSRs) have been one of the toxicities observed with administration of this drug. Of 301 patients treated, 32 patients have had definite (27 patients) or possible (five patients) hypersensitivity reactions to taxol. All but one patient had the reaction from the first or second exposure to this agent. Reactions occurred at a variety of doses and were characterized most frequently by dyspnea, hypotension, bronchospasm, urticaria, and erythematous rashes. Thirteen (41%) patients had received premedication designed to prevent such toxicity; nevertheless, they sustained HSRs. Prolonging the drug infusion appears to have somewhat reduced, but not obviated, the risk of HSRs. The cause (taxol itself or its excipient Cremophor EL; Badische Anilin und Soda-Fabrik AG [BASF], Ludwigshafen, Federal Republic of Germany) and the mechanism of these reactions to taxol are unknown. We provide guidelines to prevent or minimize such toxicity and treat reactions if they still occur.

Adult↗
PubMed1990

Quality of life assessment of Hodgkin's disease survivors: a model for cooperative clinical trials.

With the growing number of patients surviving cancer, there has been an increasing concern with their long-term adaptation. Given the large number of Hodgkin's disease survivors, it was possible to conduct a study of their psychosocial adaptation. Two hundred seventy-three survivors of advanced Hodgkin's disease were interviewed over the telephone concerning the impact of cancer upon their lives, in terms of their psychological, social, and sexual functioning. The level of psychological distress was elevated by one standard deviation above normal on the Brief Symptom Inventory (BSI), for both men and women. Survivors in greater distress reported more problems in other areas of functioning, including sexual, social, vocational, and persistent conditioned nausea.

Adaptation, Psychological↗