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Biomedical subjects

B Levin

Publications and source records attributed to B Levin.

At least 109 records · Page 6Linked to original sources
PubMed1991

Oncogene activation in esophageal cancer.

We used molecular biology techniques to study the genetic events associated with the development of human esophageal cancer. Point mutations of the p53 tumor suppressor gene were detected in one of 10 squamous cell and one of 14 adenocarcinomas of the esophagus, a frequency that implicates this gene in tumorigenesis. However, the finding of p53 mutations in Barrett's epithelium adjacent to adenocarcinomas may have clinical implications for p53 as a premalignant marker for esophageal cancer.

Adenocarcinoma↗
PubMed1991

Comparison of the adaptation of acrylic resin cured by microwave energy and conventional water bath.

Acrylic resin record bases made from three commercial resins were processed by water bath curing and by microwave energy. The adaptation of the record bases to a standard cast was measured to determine if there were any statistically significant differences in the fit that could be attributed to the differences in curing methods and the brands of resin. The results indicated a small statistically significant difference in favor of the water bath cure overall, but clinically there were no appreciable differences in the adaptation of the record bases with either curing method or the resins used. The adaptation of artificial dentures made from acrylic resin is clinically acceptable with either microwave curing or the water bath method.

Acrylic Resins↗
PubMed1990

A phase II trial of tamoxifen in hepatocellular carcinoma.

Because prolonged estrogen therapy can initiate hepatic adenomas, and estrogen receptors (ER) are found in 33% of hepatocellular carcinomas, a Phase II study of antiestrogen therapy was initiated in patients with hepatocellular carcinoma. Tamoxifen (20 mg twice a day) was administered to 33 patients who had biopsy proven and measurable hepatocellular carcinoma and who had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1. No patient had a complete or partial antitumor response; eight patients had stable disease ranging from 5 to 13 months. The median survival time for all patients was 6 months from the initiation of tamoxifen therapy. Four patients have continuing long-term survival of 18+, 22+, and 39+ months.

Adult↗
PubMed1990

The unilateral wavy clavicle.

14 patients are recorded in whom one clavicle has a wavy shape not related to trauma or to a known congenital anomaly. Since the affected clavicle is more often the right, it is suggested that this alteration may be related to the effect of subclavian artery pulsations, such as cause congenial pseudarthrosis of the clavicle.

Adult↗
PubMed1990

Paternal age and trisomy among spontaneous abortions.

The relationship of paternal age to specific types of trisomy and to chromosomally normal loss was investigated in data drawn from a case-control study of spontaneous abortions. Differences in paternal age between karyotype groups and controls delivering after 28 weeks gestation were tested using an urn model analysis which adjusted, by regression, for maternal age and, by stratification, for the effects of design variables (payment status, phase of study) and demographic factors (language, ethnicity). The magnitude of paternal age differences was estimated using least squares regression analysis. For chromosomally normal cases there was no association with paternal age. Among the fourteen trisomy categories examined, four (7, 9, 18, 21) showed increased paternal age (greater than or equal to 1 year above expectation), three (13, 20, 22) showed decreased paternal age and the rest, including the most common, trisomy 16, showed negligible differences. Only the association with trisomy 22 was statistically significant (P = 0.012), with a predicted reduction in paternal age of 2.1 years (95% CI -4.9, -0.5 years). This association did not vary with maternal age, payment status, phase of study, language or ethnicity. Because previous observations are extensive, the relation of paternal age to trisomy 21 was examined further. The overall association was not significant (beta = 0.8 years; 95% CI -0.8, 2.4 years). Moreover, there was evidence that the magnitude and direction of paternal age associations vary significantly within the sample, although not between subgroups defined on the basis of payment, phase of study, language or ethnicity. With respect to maternal age, the trend is towards a greater paternal age difference for trisomy 21 losses in younger women (P = 0.058). Given the number of tests performed, the finding for trisomy 22 and reduced paternal age could be due to chance. Among trisomy types, the direction of paternal age associations was not consistent for chromosomes grouped according to characteristics that might relate to the probability of nondisjunction, such as size, arm ratio, or nucleolar organizer region content, or to the potential viability of the trisomy. Thus, neither on statistical nor biological grounds do the data provide compelling evidence of paternal age effects on the trisomies found among spontaneous abortions, or on chromosomally normal losses.

Abortion, Spontaneous↗
PubMed1990

Phase II study of tallysomycin S10b in patients with advanced colorectal cancer.

A total of 16 patients with histologically confirmed colorectal cancer were entered into this phase II trial, designed to evaluate the efficacy and safety of tallysomycin S10b. The compound was given i.v. weekly at a dose of 2.5 mg/m2 by push injection. Pulmonary toxicity was the most significant side effect; it was observed in three patients and required treatment discontinuation in one. Skin lesions occurred in three patients. Other side effects were mild and their relationship to drug administration was ill-defined. No responses were observed in this group of patients, most of whom had received prior therapy.

Adenocarcinoma↗
PubMed1990

Evaluation of continuous-infusion alpha-difluoromethylornithine therapy for colorectal carcinoma.

A total of 32 evaluable patients with measurable advanced colorectal carcinoma were treated with continuous-infusion alpha-difluoromethylornithine (DFMO) at a median daily dose of 8 g/m2 (range, 6-14 g/m2). DFMO was infused over 24 h daily for 28 days, followed by a rest period of 7 days. Of the 32 patients, 14 had received no prior chemotherapy. A total of 65 courses was given, with the median being 2 (range, 1-9 courses). None of the patients achieved a partial or complete response; however, 3 patients achieved a minor response and 14 had stable disease. The frequent toxic effects of DFMO included thrombocytopenia (which was dose-limiting), malaise, nausea, vomiting, reversible hearing loss, and diarrhea. Our data suggest that continuous-infusion DFMO therapy is feasible and results in only mild gastrointestinal toxicity. Although DFMO proved to be ineffective as a single agent in this trial, it could probably best be used in combination with cytotoxic agents known to enhance its antitumor activity in a preclinical setting.

Carcinoma↗
PubMed1990

Establishment of a new human pancreatic adenocarcinoma cell line, MDAPanc-3.

A new cell line was established from a liver metastasis of a human pancreatic adenocarcinoma. The cell line, MDAPanc-3, which arose from a moderately differentiated adenocarcinoma, produces carbonic anhydrase II mRNA, but no detectable levels of insulin or alpha amylase mRNA. The stem line chromosome number was determined to be 43, with six marker chromosomes. Growth of MDAPanc-3 is stimulated by cholecystokinin (CCK) fragment 26-33. The cell line will be useful in further studies on the mechanism(s) by which CCK stimulates growth of certain human pancreatic adenocarcinomas and normal human pancreatic exocrine tissue.

Adenocarcinoma↗
PubMed1990

Lightening dark double-emulsion radiographs.

A simple technique is described for lightening overly dark radiographs in the interest of enhancing them for display or for making photographic slides or prints. The object of the technique is to remove the emulsion from one side of the radiograph.

Radiographic Image Enhancement↗
PubMed1990

Evaluation of pre- and postoperative chemotherapy for resectable adenocarcinoma of the esophagus or gastroesophageal junction.

Thirty-five consecutive patients with resectable adenocarcinoma of the esophagus or gastroesophageal junction were treated with two preoperative and three or four postoperative chemotherapy courses consisting of etoposide, fluorouracil, and cisplatin (EFP) to evaluate the rate of curative resection, clinical and pathologic response, toxic effects, and survival. One hundred thirty-seven courses with a median number of five courses (range, one to six) were administered. Preoperative EFP resulted in 17 (49%) major responses, including six patients who did not have carcinoma cells in the repeat endoscopic biopsy specimens and cytologic brushings. Among 32 patients who had surgery, 25 (78%) had curative resection, one patient had a complete pathologic response, and one had microscopic carcinoma in the resected specimen. Six patients had microscopic carcinoma at the resection margins and received postoperative radiotherapy. At a median follow-up of 20 months, the projected survival of 35 patients is 23 months (range, 6 to 33+). Fifteen patients died of their carcinomas, and 15 patients were alive (median follow-up, 20+ months; range, 15+ to 33+ months) with no evidence of relapse. There were no deaths related to chemotherapy, surgery, or radiotherapy. EFP-induced toxic reactions were moderate. Our data suggest that multiple courses of EFP are feasible. Future strategies for this disease should consider prolonged chemotherapy with regimens that result frequently in pathologic complete responses.

Adenocarcinoma↗
PubMed1990

Imaging with indium111-labeled anticarcinoembryonic antigen monoclonal antibody ZCE-025 of recurrent colorectal or carcinoembryonic antigen-producing cancer in patients with rising serum carcinoembryonic antigen levels and occult metastases.

We tested whether nuclear imaging with indium111 (111In)-labeled murine monoclonal (MoAb) anticarcinoembryonic antigen (anti-CEA) ZCE-025 antibody could detect recurrent disease in patients with a rising serum CEA level but negative findings for computed tomographic (CT) scans of the abdomen and pelvis, chest radiograph, and colonoscopy or barium enema. Twenty patients with a history of completely resected CEA-producing adenocarcinoma (18 with colon cancer, one with breast cancer, and one with Hodgkin's disease) and a rising serum CEA level were given an intravenous infusion of 2 mg of 111In-labeled ZCE-025 mixed with 38 mg of unlabeled ZCE-025. Planar and single-photon emission CT (SPECT) scans were acquired at 72 and 144 hours, and in 19 of the 20 patients these were positive. Of those 19, 13 underwent exploratory surgery, and cancer was found in 10, and two had a diagnostic biopsy, which confirmed cancer. Three patients who had negative laparotomies and all four patients who did not undergo surgery or biopsy were followed radiologically. In all seven, cancer was subsequently detected at the sites suggested by the ZCE-025 scan. Thus, tumor was confirmed in all 19 patients with positive scans. Five of 13 patients who were explored benefited from the study and the exploratory laparotomy, as disease was entirely resected in four or was subjected to definitive radiation therapy to the pelvis in the fifth. In two additional patients who were not explored, MoAb imaging resulted in definitive therapy to regionally confined recurrent disease. 111In-labeled anti-CEA MoAb ZCE-025 scanning in patients with rising CEA successfully imaged metastatic colorectal cancer that eluded detection by other methods and affected the care given to some. These results suggest an important role for 111In-labeled ZCE-025 scanning among patients with rising CEA and otherwise occult metastatic cancer.

Adenocarcinoma↗
PubMed1990

Confluence of pulmonary veins simulating a pulmonary mass.

Confluence of the pulmonary veins commonly appears on the frontal view of the chest and generally is easily recognized as such. On plain film tomography, computerized tomography, and pulmonary angiography, the anatomy of convergence of pulmonary veins prior to common entry into the left atrium is clearly displayed. In this report, attention is called to the occasional appearance of confluence of the pulmonary veins on the lateral view of the chest as a clearly circumscribed round opacity mimicking a lung or mediastinal mass.

Aged↗
PubMed1990

A phase II study of trimetrexate therapy for metastatic colorectal carcinoma.

Thirty patients with measurable metastatic colorectal carcinoma who had not received prior systemic therapy for advanced disease were treated with trimetrexate, a methotrexate analog. Trimetrexate was administered at a median daily dose of 15 mg/m2 (range, 6-22 mg/m2) intravenously for five days every three weeks. No patient achieved a complete or partial response, although minor responses of brief duration occurred in eight patients. The drug was generally well tolerated, thus permitting frequent dose escalations. Common toxic effects included mucositis, dermatitis, and myelosuppression. Our data suggest that trimetrexate given at these doses and in this schedule is not active against colorectal carcinoma.

Adult↗
PubMed1990

A phase II trial of recombinant human interferon-gamma and recombinant tumor necrosis factor in patients with advanced gastrointestinal malignancies: results of a trial terminated by excessive toxicity.

Recombinant human tumor necrosis factor and recombinant human interferon-gamma are two representatives of a novel class of antineoplastic agents. Evaluation of these agents in vitro has suggested that the combination would be more effective than either agent alone. A prior phase I study demonstrated that the maximum tolerated dose for each agent was 150 micrograms/m2/day for 5 days when administered concomitantly. Based on this experience, a phase II trial of patients with biliary tract, pancreatic, and colorectal cancer was planned. Our goal was to treat a minimum of 14 patients with each tumor type. However, in the first 13 patients entered into this trial the toxic effects at the starting doses of 125 micrograms/m2/day for 5 days for each agent were intolerable, with four patients unable to complete planned therapy. In this cohort of patients, no objective responses were observed. Further clinical investigation of this combination should consider alternative treatment schedules to reproduce the in vitro synergistic cytotoxicity of this combination while minimizing host toxicity.

Adolescent↗
PubMed1990

Endoscopic ultrasonography in staging rectal cancer.

Endoscopic ultrasonography (EUS) was used to stage rectal cancer by assessing depth of invasion through bowel wall layers and/or involvement of lymph nodes. EUS findings were correlated with histopathologic findings to discern the usefulness of this modality in predicting which patients could be candidates for sphinctersaving procedures and the avoidance of abdominoperineal resection. The Olympus EU-M3 endoscopic ultrasound system was used to assess depth of penetration through rectal wall layers and to identify lymph nodes. Comparison of EUS findings to histopathologic findings was possible in 13 patients. EUS agreed with histopathology in 9 of 13 cases (69.3%) ( p = 0.07, kappa statistic). EUS agreed with histopathology as the presence or absence of lymph nodes in 9 of 13 cases (69.3%) (p = 0.07). However, the presence of lymph nodes could not necessarily predict metastatic involvement of these nodes. In one patient, invasion of vaginal cuff was correctly predicted. In nine cases, computed tomographic analysis (CT) was available for comparison to EUS in detection of penetration beyond the bowel wall. CT agreed with histopathology in 3 of 9 (33%), whereas EUS agreed with histopathology in 7 of 9 (78%).

Adenocarcinoma↗