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Biomedical subjects

R B Weiss

Publications and source records attributed to R B Weiss.

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

Relationship between toxicity and obesity in women receiving adjuvant chemotherapy for breast cancer: results from cancer and leukemia group B study 8541.

PURPOSE: We examined data from a large clinical trial to determine if chemotherapy dosing according to actual body weight places obese patients at greater risk of toxicity. PATIENTS AND METHODS: Cancer and Leukemia Group B (CALGB) study 8541, a randomized study of schedule and dose of adjuvant cyclophosphamide, doxorubicin, and fluorouracil (CAF) for stage II breast cancer patients with positive regional lymph nodes, provided data on 1,435 women for analysis. Using body-mass index (BMI), we classified a woman as obese if her BMI was > or = 27.3 kg/m2; doses were considered weight-based if within 5% of values calculated using actual weight. Our primary analysis concerned toxicity risks during cycle 1. RESULTS: Among women who received weight-based doses of the most dose-intensive CAF regimen, 47% of obese and 51% of nonobese women experienced severe hematologic toxicity (grade > or = 3) during cycle 1 (P = .51, two-tailed). The overall risk ratio (obese v nonobese) of treatment failure among women who received weight-based doses during cycle 1 was 1.02 (95% confidence interval, 0.83 to 1.26), stratified by treatment and adjusted for number of positive nodes, menopausal status, hormone receptor status, and tumor size. The overall adjusted failure risk ratio (weight-based v reduced initial doses) was 0.73 (95% confidence interval, 0.53 to 1.00) among obese women. CONCLUSION: Obese patients initially dosed (within 5%) by actual weight did not experience excess cycle 1 toxicity or worse outcome compared with nonobese women dosed similarly. The data suggest that obese women who received reduced doses in cycle 1 experienced worse failure-free survival. We recommend that initial doses of CAF be computed according to actual body weight.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Postsurgical adjuvant chemotherapy of stage II breast carcinoma with or without crossover to a non-cross-resistant regimen: a Cancer and Leukemia Group B study.

PURPOSE: To compare two cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone (CMFVP) regimens with a doxorubicin-based regimen--vinblastine, doxorubicin, thiotepa, and Halotestin (Upjohn, Kalamazoo, MI) (VATH)--in patients with stage II node-positive breast carcinoma. METHODS: Nine hundred forty-five women were treated with a 6-week induction course of CMFVP. They were then randomized to receive one of two consolidation CMFVP regimens: 6-week courses or 2-week courses. Following completion of CMFVP consolidation, patients were again randomized to either continue the CMFVP regimen or to receive six escalating doses of VATH. RESULTS: Among all patients, with a median follow-up time of 11.5 years, there is no statistically significant difference in disease-free survival (DFS) between the two consolidation CMFVP regimens. VATH intensification treatment is statistically significantly superior to CMFVP in terms of DFS (P = .0040). For patients with one to three involved nodes, there is currently no significant difference between VATH and CMFVP; however, among those with four or more positive lymph nodes, there is a significant difference in favor of VATH (P = .0037). There is also improved overall survival with VATH (P = .043; median, > 14 years v 10 years). This difference is also statistically significant in patients with four or more involved lymph nodes, among postmenopausal patients, and among postmenopausal estrogen receptor-positive patients. CONCLUSION: Chemotherapy with crossover to escalating doses of VATH following CMFVP was well tolerated and effective. Inauguration of VATH as a treatment intensification at the eighth month produced a major increase in relapse-free and overall survival. The observation that sensitivity to VATH is retained so long after mastectomy raises questions about the proper duration of adjuvant chemotherapy and lends support to further investigation of cross-over designs in future trials to postoperative adjuvant chemotherapy regimens.

Adult↗
PubMed1995

Template-switching during DNA synthesis by Thermus aquaticus DNA polymerase I.

Recombinant DNA molecules are often generated during the polymerase chain reaction (PCR) when partially homologous templates are available [e.g., see Pääbo et al. (1990) J. Biol. Chem. 265, 4718-4721]. It has been suggested that these recombinant molecules are a consequence of truncated extension products annealing to partially homologous templates on subsequent PCR cycles. However, we demonstrate here that recombinants can be generated during a single round of primer extension in the absence of subsequent heat denaturation, indicating that template-switching produces some of these recombinant molecules. Two types of template-switches were observed: (i) switches to pre-existing templates and (ii) switches to the complementary nascent strand. Recombination is reduced several fold when the complementary template strands are physically separated by attachment to streptavidin magnetic beads. This result supports the hypothesis that either the polymerase or at least one of the two extending strands switches templates during DNA synthesis and that interaction between the complementary template strands is necessary for efficient template-switching.

Base Sequence↗
PubMed1995

Successful treatment of invasive aspergillosis complicating prolonged treatment-related neutropenia in acute myelogenous leukemia with amphotericin B lipid complex.

Herein we report the successful treatment of invasive aspergillosis with the liposomal amphotericin B (AMB) formulation, Amphotericin B Lipid Complex (ABLC). This investigational compound was employed in a 50-year-old patient with acute myelomonocytic leukemia complicated by prolonged, treatment-induced granulocytopenia and documented Aspergillus flavus sinusitis with signs of disseminated aspergillosis. The patient demonstrated radiographic signs of pulmonary aspergillosis and biochemical signs of hepatic involvement that were resistant to a 23 day course of conventional AMB (Fungizone) therapy. Following therapy with ABLC her fever abated, her chest X-ray findings improved, and her hepatic function tests improved with eventual resolution.

Adult↗
PubMed1995

Clinical pharmacology of cytarabine in patients with acute myeloid leukemia: a cancer and leukemia group B study.

The pharmacokinetics of cytarabine (ara-C) were determined in 265 patients with acute myeloid leukemia (AML) receiving ara-C (200 mg/m2 per day for 7 days as a continuous infusion) and daunorubicin during induction therapy. The mean (standard deviation) ara-C concentration at steady-state (Css) and systemic clearance (Cl) were 0.30 (0.13) microM and 134 (71) l/h per m2 respectively. Males had a significantly faster ara-C Cl (139 vs 131 l/h per m2, P = 0.025) than females. Significant correlations were noted between ara-C Cl and the pretreatment, peripheral white blood cell count (P = 0.005) and pretreatment blast count (P = 0.020). No significant differences in ara-C Css or Cl were noted in patients achieving complete remission compared with those failing therapy (P = 0.315, P = 0.344, respectively). No significant correlations were observed between ara-C pharmacokinetic parameters and several indices of patient toxicity. Our findings indicate that variability in ara-C disposition in plasma at this dosage level does not correlate with remission status or toxicity in patients with AML receiving initial induction therapy with ara-C and daunorubicin.

Acute Disease↗
PubMed1995

High dose toremifene for estrogen and progesterone receptor negative metastatic breast cancer: a phase II trial of the Cancer and Leukemia Group B (CALGB).

In pre-clinical and limited clinical studies, high doses ( > or = 200 mg/day) of the triphenylethylene derivative toremifene showed activity in estrogen receptor (ER) negative and ER-unknown metastatic breast cancer after progression on tamoxifen, and a mechanism of action independent of hormone receptor binding was speculated. The CALGB conducted a Phase II trial (CALGB 8945) to test the efficacy of high dose toremifene in a population of patients who had hormone receptor-negative, metastatic breast cancer with limited prior chemotherapy exposure, good performance status, and measurable disease. Twenty eligible patients received toremifene at a dose of 400 mg/day orally for 8 weeks. Toxicity was minimal. Nausea was reported by 20% of the patients, lightheadedness by 20%, weight loss by 20%, and hot flashes by 15%. There was no grade 3-4 toxicity. No objective responses were observed, and 5 of 6 patients with stable disease at 8 weeks developed progressive disease at 11 to 33 weeks. High dose toremifene (400 mg/day) is well-tolerated but imparts no detectable activity in hormone receptor-negative, metastatic breast cancer.

Administration, Oral↗
PubMed1995

Angiofollicular lymph node hyperplasia (Castleman's disease).

This review provides a comprehensive assessment of angiofollicular lymph node hyperplasia (ALNH) or Castleman's disease including pathogenesis, clinical presentation, histomorphologic and immunophenotypic findings, laboratory results, treatment, and prognosis. A division of ALNH into clinically relevant subtypes provides a framework for the consideration of the disorder. A comprehensive search of the medical literature involving ALNH using Medline was performed. Reports judged to be significant for the understanding of the disorder were analyzed and their findings incorporated into this review. ALNH is divided into localized/unicentric ALNH and generalized/multicentric ALNH due to the profound clinical differences seen between these variants. Localized/unicentric ALNH is separated by clinical and histomorphologic criteria into hyaline-vascular (HV) and plasma-cell (PC) subtypes. Generalized/multicentric ALNH may be divided by clinical criteria into generalized/multicentric ALNH without neuropathy (non-neuropathic) and generalized/multicentric ALNH with neuropathy (POEMS-associated or neuropathic). The dichotomy between these two subtypes is not absolute, with considerable clinical overlap occurring among patients presenting with generalized disease. Immunophenotypic and molecular probe studies demonstrate clonal B-cell lymphocyte populations in some cases, particularly those with generalized/multicentric ALNH. However, the finding of clonal populations is of no value in predicting malignant clinical progression. We conclude that using this division of ALNH, patients presenting with symptoms and histomorphology consistent with ALNH can be subdivided into the appropriate category of ALNH. Localized or unicentric disease, either HV or PC subtype, has an excellent prognosis with surgery being curative in the majority of cases. Generalized or multicentric disease indicates a poor prognosis with short survival, with the neuropathic variant possessing resistance to steroids and chemotherapy and a corresponding worse prognosis.

B-Lymphocytes↗
PubMed1995

Constitutional heteromorphism of 9q13 --> q21 in a patient with chronic myelogenous leukemia.

Cytogenetic studies were carried out in a 44-year-old white male because of newly diagnosed chronic myelogenous leukemia. His initial bone marrow study revealed 46,XY, var(9)(q13 -->q21)/46,XY,var(9) (q13-->q21), t(9;22)(q34;q11) karyotypes and later he also acquired a 47,XY,+8,var(9)(q13-->q21), t(9;22)(q34;q11) clone. The var(9)(q13-->q21) heteromorphism was observed in the normal 9 homolog, in 200 GTG-banded bone marrow metaphases in seven cytogenetic studies (1988-90). This heteromorphism was observed in the normal cell line, in the two chronic myelogenous leukemia-related clones, as well as in 100 mitogen-induced peripheral blood lymphocytes, indicating its constitutional nature. This seems to be the first report of var(9)(q13 --> q21) heteromorphism, involving GTG-positive euchromatic band, in a chronic myelogenous leukemia proband.

Adult↗
PubMed1994

A mutation in ribosomal protein L9 affects ribosomal hopping during translation of gene 60 from bacteriophage T4.

Ribosomes hop over a 50-nt coding gap during translation of gene 60 mRNA from bacteriophage T4. This event occurs with near-unitary efficiency when gene 60-lacZ fusions are expressed in Escherichia coli. One of the components necessary for this hop is an RNA hairpin structure containing the 5' junction of the 50-nt coding gap. A mutant E. coli was isolated and found to significantly increase hopping when carrying gene 60-lacZ constructs with altered hairpins. The mutation, hop-1, changed Ser93 to Phe in rplI, the gene coding for ribosomal large-subunit protein L9. Ribosomal hopping on a synthetic sequence in the absence of a hairpin was also increased by this mutation. These data suggest that hop-1 may substitute for the function of the hairpin during ribosomal hopping.

Amino Acid Sequence↗
PubMed1994

Lymphomatoid papulosis associated with Ki-1-positive anaplastic large cell lymphoma. A report of two cases and a review of the literature.

BACKGROUND: Lymphomatoid papulosis (LyP) is an uncommon disorder characterized by recurrent papulonodular cutaneous lesions that last from 4 to 5 weeks and often heal with hypopigmented or hyperpigmented scarring. Prognosis is varied, 10%-20% of patients have associated lymphomas: mycosis fungoides, T-cell immunoblastic lymphoma, or Hodgkin's disease, which can precede, occur simultaneously with, or follow the diagnosis of LyP. Anaplastic large cell lymphoma (ALCL) is histologically and phenotypically similar to LyP and also appears as part of this disease spectrum. Recent reports analyzing immunophenotype and T-cell receptor gene rearrangements in patients with both LyP and lymphoma suggest that they are derived from an identical T-cell clone, in the rare cases studied. METHODS: The case histories of two patients with LyP in whom ALCL involving the skin and lymph nodes subsequently developed are presented. RESULTS: Intensive treatment with combination chemotherapy resulted in complete remission of ALCL in both patients, followed by the recurrence of LyP. A spontaneous remission of LyP occurred in the initial patient described, whereas the second patient suffered recurrences of both LyP and ALCL despite therapy. CONCLUSIONS: The case histories presented illustrate the immunophenotypic and morphologic similarities of ALCL and LyP, and the difficulties in distinguishing between them. Both entities can occur in a single patient, as shown by this report, supporting a close relationship between these processes. However, different clinical behavior and response to therapy are apparent, which connote a fundamental difference in the biologies of these neoplastic disorders. A review of the literature concerning the association between these entities is provided.

Aged↗
PubMed1994

Recurrent granulocytic sarcoma. An unusual variation of acute myelogenous leukemia associated with 8;21 chromosomal translocation and blast expression of the neural cell adhesion molecule.

This study reports on a patient with acute myelogenous leukemia (AML) in remission who had a series of 11 granulocytic sarcomas (chloromas or myeloblastomas) appearing periodically over a 29-month interval in a variety of anatomic sites without evidence of bone marrow recurrence. This isolated extramedullary recurrence of AML is distinctly unusual with only 24 cases described previously. This patient had the greatest number and longest reported interval of recurrent granulocytic sarcomas (GS) before bone marrow relapse. Furthermore, he represents the first case of a patient with GS presenting with both an 8;21 chromosomal translocation and neural cell adhesion molecule (CD56) expression. The authors hypothesize that these two abnormalities identified previously as predisposing factors to GS may, in fact, be synergistic for this phenomenon. His case and the review of the literature demonstrate some of the important clinical and management features of a patient who develops GS while in complete marrow remission from previous AML. Although highly sensitive to radiation therapy, the onset of granulocytic sarcomas is almost always followed by bone marrow relapse and should be treated with aggressive reinduction chemotherapy and local irradiation. Such therapy is associated with the longest interval of disease-free survival.

Adult↗
PubMed1994

Enzyme-linked fluorescent detection for automated multiplex DNA sequencing.

Initiatives to sequence DNA on a large scale have created a need for increased throughput and decreased costs. One scheme for increasing throughput, multiplex sequencing, involves the processing of a mixture of sequencing templates followed by sequential hybridization to reveal the individual sequence ladders on a membrane. Because multiplex sequencing has not been fully automated, and has not seemed automatable, few sequencing efforts have attempted to exploit it. We describe here a scheme for the automation of multiplex sequencing. Probe hybridized to target DNA is detected via spatially localized enzyme-linked fluorescence. Light output is high enough that imaging is possible with simple instrumentation. Direct imaging within an automated hybridization apparatus is made feasible so that the entire process will be automatic once a multiplex membrane is produced. The technique has the potential to increase severalfold the throughput of automated sequencing instruments required for sequencing the human genome.

Base Sequence↗
PubMed1994

Multicentric angiofollicular lymph node hyperplasia and associated carcinoma.

There is a well described association between multicentric angiofollicular hyperplasia and non-Hodgkin's lymphoma and/or Kaposi's sarcoma. Two cases of multifocal angiofollicular hyperplasia and associated carcinomas and non-Hodgkin's lymphoma are reported. We suggest that underlying immunological defects in patients with multicentric angiofollicular hyperplasia make them susceptible to the development of carcinomas, as well as non-Hodgkin's lymphoma and Kaposi's sarcoma.

Adenocarcinoma↗
PubMed1994

A phase II trial of didemnin B in myeloma. A Cancer and Leukemia Group B (CALGB) study.

Didemnin B is a member of a class of compounds, derived from a marine source, undergoing phase II study. Twenty-two patients with relapsed myeloma were treated with didemnin B at an initial dose of 4.9 mg/m2, given once every 28 days. All were evaluable for toxicity, and 15 were evaluable for myeloma response. No tumor regressions occurred in the 15 patients evaluable for response. Vomiting was the major toxicity, occurring in 73% of patients despite vigorous pre- and post-treatment medication with at least three intravenous antiemetics. Two instances of grade 4 hypersensitivity reaction occurred. We conclude that didemnin B has no activity at this dose and schedule in myeloma that has relapsed after one or two prior therapeutic regimens.

Antineoplastic Agents↗
PubMed1994

An efficient Shine-Dalgarno sequence but not translation is necessary for lacZ mRNA stability in Escherichia coli.

The 5' ends of many bacterial transcripts are important in determining mRNA stability. A series of Shine-Dalgarno (SD) sequence changes showed that the complementarity of the SD sequence to the anti-SD sequence of 16S rRNA correlates with lacZ mRNA stability in Escherichia coli. Several initiation codon changes showed that an efficient initiation codon is not necessary to maintain lacZ mRNA stability. A stop codon in the 10th codon of lacZ increased mRNA stability. Therefore, ribosomal binding via the SD sequence but not translation of the coding region is necessary to maintain lacZ mRNA stability.

Codon↗
PubMed1993

Cigarette smoking and risk of acute leukemia: associations with morphology and cytogenetic abnormalities in bone marrow.

BACKGROUND: Cigarette smoking may be a risk factor for leukemia. No detailed biological mechanism has been proposed, but a causal link is made plausible by evidence of systemic effects of cigarette smoke and the presence in cigarette smoke of chemicals that have been associated with leukemia risk. PURPOSE: Our purpose was to investigate the leukemia risk associated with cigarette smoking in a multicenter case-control study of acute leukemias in adults. METHODS: Adults aged 18-79 with newly diagnosed leukemia were contacted to participate in this epidemiologic study when they entered a clinical trial to be treated under protocols sponsored by Cancer and Leukemia Group B. Smoking histories for 610 patients with acute leukemia and 618 population control subjects were obtained by telephone interviews. We examined bone marrow samples and classified patients by morphology of leukocyte precursor cells according to the French-American-British (FAB) classification system and, for 378 patients, by the presence or absence of specific clonal chromosome abnormalities. We calculated odds ratios (ORs) for risk of leukemia associated with smoking cigarettes. ORs were adjusted for age, race, and sex. RESULTS: Smoking was associated with only a modest increase in risk for leukemia overall (adjusted OR = 1.13; 95% confidence interval [CI] = 0.89-1.44). However, among participants aged 60 and older, smoking was associated with a twofold increase in risk for acute myeloid leukemia (AML) (OR = 1.96; 95% CI = 1.17-3.28) and a threefold increase in risk for acute lymphocytic leukemia (ALL) (OR = 3.40; 95% CI = 0.97-11.9). Among older persons, risks increased with amount and duration of smoking. Smoking was associated with increased risk for AML classified as FAB type M2 at all ages, with ORs of 1.70 (95% CI = 1.00-2.90) for those younger than 60 and 3.50 (95% CI = 1.53-8.03) for those aged 60 and older. Smoking was also associated with ALL type L2 at all ages, with ORs of 1.72 (95% CI = 0.90-3.27) for those younger than 60 and 5.34 (95% CI = 1.03-27.6) for those who were older. Smoking was more common among patients with specific chromosome abnormalities in AML [-7 or 7q-, -Y, +13] and in ALL [t(9;22)(q34;q11)]. CONCLUSIONS: Cigarette smoking is associated with increased risk for leukemia and may lead to leukemias of specific morphologic and chromosomal types. The association varies with age. IMPLICATION: Examining discrete subtypes of disease may permit more accurate assessment of risk. As standardized morphologic classification and cytogenetic and molecular evaluation of leukemia patients becomes more common, epidemiologic studies that take advantage of these advances will begin to contribute to the identification of additional risk factors and mechanisms in acute leukemia.

Acute Disease↗