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Biomedical subjects

B Levin

Publications and source records attributed to B Levin.

At least 127 records · Page 7Linked to original sources
PubMed1994

Neurobiologic considerations in early surgery for epilepsy.

Children with well-localized medically resistant seizures are often referred for surgical therapy. In young children, at least three maturational issues play a significant role in the selection process and long-term outcome. First, the early years are a time of exceptionally rapid brain development leading to dynamic changes in the electroencephalogram and the clinical expression of seizures. Many early-onset seizure presentations are also associated with catastrophic outcomes, developmental arrest, or regression. Second, the immature limbic system may be vulnerable to stresses operating in early life, although the consequences may not become apparent for many years. Third, in comparison to the adult, the child's nervous system typically exhibits superior functional recovery after lesioning, but the process of sparing and recovery is often incomplete. An understanding of how these neurobiologic factors influence developmental outcome will ultimately lead to greater selectivity of candidates for early surgery and to improved long-term prognosis.

Animals↗
PubMed1993

A phase I-II trial of mitoxantrone by hepatic arterial infusion in patients with hepatocellular carcinoma or colorectal carcinoma metastatic to the liver.

BACKGROUND: Mitoxantrone is an anthraquinone derivative that has demonstrated encouraging preclinical and clinical activity against a variety of human carcinoma cell lines and malignancies. Three Phase II studies of systemically administered mitoxantrone in patients with colorectal carcinoma failed to demonstrate any therapeutic activity, as did four Phase II studies of intravenous mitoxantrone in hepatocellular carcinoma. Two additional trials demonstrated limited activity when administered intravenously to patients with hepatocellular carcinoma. However, because this drug exhibits a steep dose-response curve, a Phase I-II trial of mitoxantrone by hepatic arterial infusion was initiated. METHODS: Patients with hepatocellular carcinoma and metastatic colorectal carcinoma with liver only or liver-predominant disease were eligible for therapy. All patients underwent the placement of a percutaneous hepatic arterial catheter before each course of therapy, and the first cohort of patients was treated at 10 mg/m2/course on day 1 on a 28-day cycle. Dosages were escalated in increments of 2 mg/m2/course based on side effects and tolerance. RESULTS: Twenty-eight patients with bidimensionally measurable unresectable, liver-predominant disease were entered into this trial. The therapy was well tolerated, with only 5 courses of 55 being complicated by neutropenia and none associated with fever. Only one patient required a dosage reduction on the basis of toxicity (neutropenia). No complete or partial responses were observed. CONCLUSION: These data are consistent with a lack of therapeutic activity of mitoxantrone when administered by hepatic arterial infusion for the treatment of hepatocellular carcinoma or metastatic colorectal cancer.

Adult↗
PubMed1993

Low serum alpha-fetoprotein level in patients with hepatocellular carcinoma as a predictor of response to 5-FU and interferon-alpha-2b.

BACKGROUND: A Phase II clinical trial was conducted to evaluate the efficacy of intravenous fluorouracil (5-FU) and subcutaneous recombinant interferon-alpha-2b (rIFN-alpha-2b) in the treatment of hepatocellular carcinoma (HCC) and to define factors that might be predictive of a response to treatment. METHODS: Twenty-nine patients were registered on the protocol. 5-FU was administered as a continuous intravenous (i.v.) infusion (dose = 750 mg/m2) for 5 consecutive days. rIFN-alpha-2b was administered subcutaneously (SC) (dose = 5 x 10(6) um/m2) once a day on days 1, 3, and 5 of the 5-FU infusion. The treatment was repeated at 14-day intervals. Responses were assessed at the end of one course of therapy, which was equivalent to four treatments. RESULTS: Of the 28 patients evaluable for response, 5 (18%) had a partial response, and 1 (4%) had a minor response. Responses lasted from more than 2 to more than 24 months (median, 11.5 months). Ten (36%) patients experienced no response, and 12 (43%) had progressive disease. The 6 responders were part of a group of 16 patients who had pretreatment levels of serum alpha-fetoprotein (AFP) of 50 ng/ml or less and a group of 8 whose tumors involved 50% or less of the liver parenchyma. Mucositis, which occurred in 54% of the patients, was the most common toxicity associated with the treatment regimen. Diarrhea and dermatitis were observed in 16% and 17% of the patients, respectively; fatigue, thrombocytopenia, granulocytopenia, neurologic toxicity, and nausea and vomiting were not commonly seen. CONCLUSIONS: The regimen of i.v. 5-FU and SC rIFN-alpha-2b was well tolerated and induced durable partial response in 31% (5 of 16) of patients with HCC who had low levels of serum AFP and in those with 50% or less of liver replacement. In contrast, the treatment regimen was ineffective in patients with HCC who had high levels of serum AFP or extensive liver disease.

Adolescent↗
PubMed1993

Urinary aflatoxin levels, hepatitis-B virus infection and hepatocellular carcinoma in Taiwan.

Using a urinary immunoassay to measure aflatoxin metabolites, we examined the associations between exposure to aflatoxin, chronic infection with the hepatitis-B virus (HBV) and background rates of hepatocellular carcinoma (HCC) mortality in a cross-sectional survey of 250 residents from 8 areas of Taiwan with a 4-fold variation in age-adjusted HCC mortality. Specimens of fasting blood and overnight urines were used to determine HBV carrier status and excretion of aflatoxin in the subjects surveyed. While the prevalence of hepatitis-B virus carriers showed moderate variability, there was a 500-fold range in urinary aflatoxin levels. Mean log-transformed levels of aflatoxin metabolites were similar in males and females and in HBV carriers and non-carriers. In the 8 townships, HCC mortality correlated positively with both area HBV carrier prevalence and mean aflatoxin levels. The primary analyses, however, were conducted at the individual level. Each subject's aflatoxin level was treated as the response variable in a multiple regression model, and the corresponding sex-specific area HCC rate was included as a predictor along with the individual's carrier status, age and sex; alcohol consumption and cigarette smoking were also considered. In these analyses, a significant association was again observed between the marker of aflatoxin exposure and the background rate of HCC mortality. In females, the slope of the regression line was somewhat steeper in HBV carriers, but this pattern was not seen in males and formal testing yielded no statistically significant evidence of an interaction. Our findings are consistent with the hypothesis that aflatoxin plays an independent role in hepatocellular carcinoma in Taiwan.

Adult↗
PubMed1993

Maternal exercise during pregnancy, physical fitness, and fetal growth.

The value of exercise during pregnancy is controversial; both benefits and risks have been hypothesized. As empiric evidence is scant, the issue was investigated in a prospective study that assessed the impact on fetal growth of maternal exercise in each trimester of pregnancy. A cohort of over 800 prenatal patients was recruited from obstetric practices in Pennsylvania and New York between January 1987 and June 1989. Subjects were interviewed at entry into care and recontacted at 28 and 36 weeks of gestation. In women with prior adverse outcomes or a lack of conditioning, the associations between maternal exercise and fetal growth were equivocal. In fit, low-risk, prenatal patients, exercise was positively associated with fetal growth. With low-moderate exercise levels, the adjusted mean birth weights were about 100 g higher than in nonexercisers (117 g; 95% confidence interval 17 to 217 g). With heavier exercise, larger birth weight increments were seen, close to 300 g in those who exercised throughout pregnancy at levels of about 2,000 kcal/week in energy expenditure (276 g; 95% confidence interval 54 to 497 g). These results suggest that the guidelines issued by the American College of Obstetricians and Gynecologists may be too stringent for well-conditioned, low-risk, prenatal patients. Additional research to define safe limits more precisely seems warranted.

Adult↗
PubMed1993

Phase II evaluation of recombinant alpha-2a-interferon and continuous infusion fluorouracil in previously untreated metastatic colorectal adenocarcinoma.

BACKGROUND: Thirty-nine patients with advanced measurable metastatic colorectal carcinoma were entered in a clinical trial of recombinant alpha-2a-interferon (r alpha-2a-IFN) and continuous-infusion 5-fluorouracil (5-FU). Patients had not been treated previously with chemotherapy and had bidimensionally measurable disease. METHODS: A course of therapy consisted of a 5-day continuous infusion of 5-FU, 750 mg/m2/day, with r alpha-2a-IFN, 9 x 10(6) IU, subcutaneously, on days 1, 3 and 5 of the 5-FU infusion. A course of therapy was repeated every 15 days, and patients were examined for response after receiving four courses of therapy. RESULTS: One patient had a complete response, and 11 patients experienced partial responses, for an overall response rate of 31% (95% confidence interval [CI], 17-48%). The median duration of response was 7.5 months (range, 2-13 months). Fifty-two percent of the patients entered in this trial are alive at time of this writing, with a median follow-up duration of 12.2 months (range, 6-24 months). Grade 3-4 toxicities included mucositis (nine patients), diarrhea (two patients), granulocytopenia (two patients), and fatigue (three patients). CONCLUSION: This regimen of 5-FU with r alpha-2a-IFN administration does not appear to be superior to previously published schedules of 5-FU with r alpha-2a-IFN or to other methods that modulate 5-FU.

Abdominal Neoplasms↗
PubMed1993

Cigarette smoking and trisomy 21 at amniocentesis.

Several studies raise the possibility that smoking during pregnancy is associated with a slightly decreased odds of trisomy 21 at birth. If it is, associations may reflect decreased incidence at conception, increased intrauterine loss (at one or several times in gestation), or both. Women (n = 13,729) undergoing prenatal diagnosis completed a questionnaire before learning karyotype results. For each women with a trisomy, up to 4 controls with chromosomally normal pregnancies, matched for age and hospital, were selected. Analyses drew on the 89 trisomy 21-control matched m-tuples in which diagnosis was by amniocentesis at 14-26 weeks. We compared the odds of smoking at last menstrual period and in the past in cases and controls. The odds of current smoking versus never smoking were decreased [adjusted odds ratio = 0.8, 95% confidence interval (CI) 0.4-1.6] and the odds of exsmoking increased (adjusted odds ratio = 1.4, 95% CI 0.9-2.4) in trisomy 21 cases. The association with current smoking was essentially unchanged when the unexposed reference group was defined as exsmokers and women who never smoked (adjusted odds ratio = 0.7, 95% CI 0.4-1.4). These results for current smoking agree well with a summary estimate based on combined studies of births. One interpretation is that at amniocentesis, as has been reported for births, current smoking is associated with a slightly decreased odds of trisomy 21. If associations at amniocentesis and birth are of equal magnitude, the explanation that observations at birth reflect increased loss in the second half of pregnancy with current smoking is unlikely to be correct.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Chemoradiation therapy for anal cancer: radiation plus continuous infusion of 5-fluorouracil with or without cisplatin.

Chemoradiation therapy for anal cancer was carried out in 58 patients using low-dose, continuous infusion of 5-fluorouracil (5-FU) with or without continuous infusion of cisplatin (cDDP) and external beam irradiation (chemoXRT). Thirty-nine patients received 5-FU chemoXRT resulting in a local control rate of 50% in those receiving a total dose of < 45 Gy, 73% for those receiving 50-54 Gy, and 83% for those receiving > 60 Gy. The actuarial local control rate at 2 years was 77% after chemoXRT alone; overall local control was 67% at 5 years. In 18 patients receiving 5-FU plus cisplatin with radiation doses of 54-55 Gy, actuarial local control was 85% at 2 years. Fifteen patients failed chemoXRT, 13 of whom had abdominoperineal resection for salvage; the overall local control rate was 93% (54/58). The actuarial survival at 5 years was 81% for the 5-FU chemoXRT group and 94% at 2 years for the 5-FU plus cisplatin chemoXRT group; median follow-up was 54 and 20 months, respectively. Diarrhea and nausea were the most frequent early reactions and were ameliorated by limiting the duration of chemotherapy to 5 days/week and by using XRT techniques to exclude the small bowel from the radiation portal. Serious late radiation complications have not been observed and may be related to XRT fractionation and the use of protracted chemotherapy infusion. The absence of late morbidity coupled with the high local control rate by the use of this chemoXRT program is an area to investigate for improving the therapeutic ratio for the treatment of anal cancers.

Anal Gland Neoplasms↗
PubMed1993

Endoscopic ultrasonography in the quantitative assessment of response to chemotherapy in patients with adenocarcinoma of the esophagus and esophagogastric junction.

We used endoscopic ultrasonography (EUS) to clinically stage eight patients with adenocarcinoma of the esophagus and to monitor their disease after subsequent courses of experimental preoperative chemotherapy. Stage of disease (TNM), tumor area, and tumor width were determined at each session. These results were then compared with barium esophagram and histopathology from resection specimens. EUS provided a consistent interpretation of the stage of disease and accurately predicted histopathologic findings. Measurement of tumor area and maximal width did not reliably correlate with the response to chemotherapy as assessed by barium esophagram. Although this technique seems promising, it cannot yet be recommended as a means of predicting response to chemotherapy.

Adenocarcinoma↗
PubMed1993

Intensive preoperative chemotherapy with colony-stimulating factor for resectable adenocarcinoma of the esophagus or gastroesophageal junction.

PURPOSE: The curative resection rate in patients with potentially resectable carcinoma of the esophagus is approximately 55% and their median survival time is 11 months. Preoperative chemotherapy with high doses of chemotherapeutic agents was used to evaluate clinical and pathologic responses, curative resection rate, toxicity, and survival. Colony-stimulating factor (CSF) was added to reduce the severity of myelosuppression. PATIENTS AND METHODS: Twenty-six consecutive assessable patients with potentially resectable adenocarcinoma of the esophagus or gastroesophageal junction were treated with two preoperative courses of intensive chemotherapy (etoposide, doxorubicin, and cisplatin [EAP]) with granulocyte-macrophage CSF (GM-CSF). Additional three conventional-dose postoperative chemotherapy courses without GM-CSF were given to patients who responded to preoperative chemotherapy. RESULTS: A median of three courses (range, one to six), were administered. Of 27 patients, 26 were assessable for response to preoperative EAP; 13 (50%) achieved a major response. Among 23 patients who underwent surgery, 15 (65%) had a curative resection (58% of 26 assessable patients); none of the patients had a pathologic complete response, but two patients had only microscopic carcinoma in the resected specimen. Six patients had carcinoma present at the resection margins and received postoperative radiotherapy. Two patients were found to have liver metastases at exploration. At a median follow-up of 22 months, the median survival of 26 patients was 12.5 months (range, 2 to 32 +). Fourteen patients died of their carcinoma; two patients died of treatment-related causes; one died of an unrelated CNS arterial malformation; and the causes of death in two patients remain unknown. Seven patients are alive with no evidence of relapse. Major toxicities of this regimen included severe myelosuppression, nausea and vomiting, infections, and severe constitutional symptoms related to GM-CSF. However, subcutaneous injection of GM-CSF was well tolerated. CONCLUSION: High-dose EAP is active against locoregional adenocarcinoma of the esophagus and gastroesophageal junction but can be associated with significant toxicity. Although this strategy remains attractive and needs to be developed further, less toxic and more effective regimens need to be identified.

Adenocarcinoma↗
PubMed1993

A phase II study of merbarone in patients with adenocarcinoma of the pancreas.

Merbarone, a nonsedating derivative of thiobarbituric acid that has demonstrated antineoplastic activity against a variety of murine tumors, was evaluated in a phase II trial in patients with advanced, measurable adenocarcinoma of the pancreas. Seventeen patients were treated at a starting dose of 1000 mg/m2/day for 5 days by continuous intravenous infusion; the dose was escalated in accordance with the toxicity experienced, and no dosage reductions owing to toxicity were required. No complete or partial responses were observed, and only one minor response was documented, suggesting that merbarone is ineffective against pancreatic cancer at the doses and schedule in which it was administered in this trial.

Adenocarcinoma↗
PubMed1992

Phase II evaluation of fluorouracil and recombinant alpha-2a-interferon in previously untreated patients with pancreatic adenocarcinoma.

BACKGROUND: Based on initial encouraging results of the combination of 5-fluorouracil (5-FU) with recombinant alpha-2a-interferon (r alpha-2a-IFN) in the treatment of advanced colorectal carcinomas, a clinical trial was conducted using 5-FU with r alpha-2a-IFN in 49 patients with advanced pancreatic adenocarcinoma. METHODS: Forty-nine patients who had bidimensionally measurable disease and had not been treated previously with chemotherapy were entered in the trial. Starting on day 1, 5-FU was administered as a continuous infusion at a dose of 750 mg/m2/day for 5 consecutive days. Starting on day 12, it was administered as an intravenous bolus of 750 mg/m2 a week for 7 weeks. The r alpha-2a-IFN was administered subcutaneously at a dose of 9 x 10(6) units three times a week during weeks 1-8. RESULTS: Of the 46 patients evaluable for response, none had a complete response, and two had partial responses that lasted 14 and 28 weeks. The overall response rate was 4% (95% confidence interval, 1-15%). Fourteen patients had minor responses (median duration of response, 12 weeks). The median length of survival of all patients enrolled in this trial was 22 weeks. Grade 3-4 toxicities included oral mucositis in 19 patients, granulocytopenia in 16, fatigue in 8, and diarrhea in 3. One patient had severe ataxia and leg weakness. Another died of neutropenic sepsis. CONCLUSIONS: This regimen had significant toxicity and little evidence of therapeutic activity against advanced pancreatic carcinoma.

Adult↗
PubMed1992

Nutrition and colorectal cancer.

Environmental and genetic factors play an important role in the cause and pathogenesis of colorectal cancer. In addition to nutritional aspects, other environmental factors include physical exercise, energy intake, obesity, and parity. Dietary components currently under study are dietary fiber, fat, fruits, vegetables, and calcium. Intermediate markers of colonic proliferation, including bromodeoxyuridine and proliferating cell nuclear antigen incorporation, are being used to evaluate the response of the colonic epithelium to putative chemopreventative agents.

Animals↗
PubMed1992

Inflammatory bowel disease and colon cancer.

Patients who have had extensive colitis for more than 10 years are at increased risk for colorectal cancer. The risk may be greatest for those whose onset of illness is in childhood. Management options for patients at increased risk include prophylactic colectomy or endoscopic surveillance. The object of surveillance is prevention of cancer by detecting premalignant lesions that predispose to cancer. A less desirable objective is the diagnosis of cancer at an early curable stage. Patients must be well informed about their risk for cancer, the limitations of endoscopic surveillance, and the availability of surgical alternatives. Current endoscopic and pathologic techniques focus on the detection of dysplasia, but newer biomarkers may offer greater sensitivity and specificity in the future.

Adolescent↗
PubMed1992

Quantitation of human tumor-reactive monoclonal antibody 16.88 in the circulation and localization of 16.88 in colorectal metastatic tumor tissue using murine antiidiotypic antibodies.

Detection of administered human monoclonal antibodies in the tissues and circulation of patients requires special reagents to overcome interference by normal endogenous immunoglobulin. A practical approach is the development of antiidiotypic antibodies to the human monoclonal antibody and their application in immunoassays specific for the human monoclonal antibody. Accordingly, antiidiotypic antibodies were made to the monoclonal antibody 16.88, a human IgM class anti-colon carcinoma antibody being developed for applications in antibody-targeted immunotherapy of cancer. Three stable clones were obtained that produced antiidiotypic antibodies reactive with 16.88 but nonreactive with human polyclonal IgM or 16.52, a patient-matched IgM monoclonal antibody with different specificity than 16.88. One antiidiotypic antibody, MID 65, was used in a capture format radioimmunoassay to detect 16.88 in the sera of patients who had received 108-mg doses of unlabeled 16.88 coadministered with trace doses of 131I-16.88. Using this assay it was demonstrated that unlabeled 16.88 antibody and 131I-labeled 16.88 antibody did not differ significantly in blood retention for up to 24 h after administration, the period during which the immunoreactivity of the administered antibody remained over 90%. Indirect microautoradiography using exogenously applied 125I-MID 65 to localize 16.88 in frozen metastatic tumor tissue from patients given 16.88 8 days prior to surgery demonstrated the accumulation of 16.88 in areas of apparently healthy tumor cells. Much less 16.88 was detected in stroma or areas of tumor cell necrosis. The accumulation of antibody in nonnecrotic tumor sites encourages the further development of 16.88 for radioimmunotherapy of colon cancer and provides support for further development of human anticytokeratin monoclonal antibodies for cancer therapy.

Animals↗