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Biomedical subjects

B Leventhal

Publications and source records attributed to B Leventhal.

At least 19 recordsLinked to original sources
PubMed2000

Hypertension-induced organ damage in African Americans: transforming growth factor-beta(1) excess as a mechanism for increased prevalence.

Hypertension is prevalent world-wide, and it affects over 50 million individuals in the United States alone. African Americans (blacks) have a high prevalence of hypertension, develop it at an earlier age, and suffer excessively from severe or malignant hypertension. They also have a high prevalence of target organ damage attributable to hypertension, including left ventricular hypertrophy, stroke, end-stage renal disease (ESRD) and coronary artery disease. Hypertensive nephrosclerosis is particularly more prevalent in blacks compared to whites, and there is evidence that factors in addition to elevated blood pressure contribute to its pathogenesis. Transforming growth factor-beta 1 (TGF-beta1) is a fibrogenic cytokine that has been implicated in the development and progression of experimental and human renal diseases. We have demonstrated that blacks with ESRD have higher circulating levels of TGF-beta1 protein compared to whites with ESRD. We have also found that hyperexpression of TGF-beta1 is more frequent in blacks with hypertension than in whites. We propose that TGF-beta1 hyperexpression may be an important mediator of hypertension and hypertensive nephrosclerosis. We hypothesize also that the increased frequency of TGF-beta1 hyperexpression may contribute to the excess burden of ESRD in blacks. Based on our hypotheses, and the observations that angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists reduce angiotensin II-mediated stimulation of TGF-beta1 production, we propose that treatment with these agents might be efficacious in preventing or slowing the progression of target organ damage in hypertensive blacks.

Angiotensin II↗
PubMed1999

High throughput fluorescent CE-SSCP SNP genotyping.

Large numbers of single nucleotide polymorphisms (SNPs) are being identified by several laboratories for the purpose of developing dense genetic maps. Single-strand conformation polymorphism (SSCP) analysis has been widely used as a method for detecting novel sequence variations in PCR products. Differences in migration of single-stranded DNA can be used not only to find mutations, but to genotype SNPs in large sample populations. Using PCR with fluorescent labeling and automated capillary electrophoresis SSCP (CE-SSCP), we have developed a panel of 15 functional candidate SNPs. With an automated single capillary instrument, relatively rapid and low cost CE-SSCP SNP genotyping using currently available technology is feasible for 135 000 genotypes per year. With parallel multiple array capillary electrophoresis, more genotypes per year may be attainable.

Automation↗
PubMed1997

Randomized study of intensive MOPP-ABVD with or without low-dose total-nodal radiation therapy in the treatment of stages IIB, IIIA2, IIIB, and IV Hodgkin's disease in pediatric patients: a Pediatric Oncology Group study.

PURPOSE: To determine whether the addition of low-dose total-nodal irradiation (TNI) in pediatric patients with advanced-stage Hodgkin's disease who have received eight cycles of alternating mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) and doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) will improve the event-free survival (EFS) and overall survival (OS) when compared with patients who have received chemotherapy only. PATIENTS AND METHODS: At diagnosis, 183 children and adolescents with stages IIB, IIIA2, IIIB, and IV Hodgkin's disease were randomized to receive eight cycles of alternating MOPP-ABVD with or without low-dose TNI. RESULTS: Of 183 patients, four were rendered ineligible before treatment was initiated. One hundred sixty-one of 179 patients (90%) were in complete remission (CR) at the completion of eight cycles of alternating MOPP-ABVD; 81 were in the chemotherapy-only group and proceeded to observation off therapy, whereas 80 of 161 were to receive combined modality therapy (CMT). Nine of 80 patients randomized at the time of diagnosis to receive CMT did not receive radiation (RT) because of a protocol violation, but were monitored for EFS and OS and included in all analyses. The estimated EFS and OS rates at 5 years for the 179 eligible patients are 79% and 92%, respectively. The actuarial EFS at 5 years was 80% for patients who received CMT and 79% for patients who received MOPP-ABVD only. The OS for the former group is estimated to be 87% and for the latter patients 96%. Age < or = 13 years of age at diagnosis and the attainment of a clinical CR after three cycles of chemotherapy were associated with a statistically significant improved EFS. CONCLUSION: Our results indicate that after the delivery of eight cycles of MOPP-ABVD, the addition of low-dose RT does not improve the estimated EFS or OS in pediatric patients with advanced-stage Hodgkin's disease.

Adolescent↗
PubMed1994

Intensive intravenous methotrexate and mercaptopurine treatment of higher-risk non-T, non-B acute lymphocytic leukemia: A Pediatric Oncology Group study.

PURPOSE: To determine the potential efficacy and toxicity of intravenous (i.v.) methotrexate (MTX) and mercaptopurine (MP) as postremission intensification treatment for children with B-lineage acute lymphoblastic leukemia (ALL) at higher risk to relapse. PATIENTS AND METHODS: Eighty-three patients (age 1 to 20 years) with higher-risk B-lineage ALL were entered onto this protocol. Following standard four-drug remission induction, 80 patients received 12 intensive 2-week cycles of MTX/MP: MTX 200 mg/m2 i.v. push, then 800 mg/m2 i.v. 24-hour infusion on day 1; MP 200 mg/m2 i.v. in 20 minutes, then 800 mg/m2 i.v. 8-hour infusion day 2; MTX 20 mg/m2 intramuscularly day 8; and MP 50 mg/m2 by mouth days 8 to 14. Age-based triple intrathecal therapy (MTX, hydrocortisone, and cytarabine) was administered for CNS prophylaxis. Continuation therapy was weekly MTX/MP (as on days 8 to 14) for 2 years. RESULTS: Eighty-one patients (98%) entered remission. There were 28 relapses (marrow, n = 11; marrow and CNS, n = 2; isolated CNS, n = 9; testes, n = 5; ovaries, n = 1). No overt relapse occurred during the intensive phase of therapy. The event-free survival (EFS) rate at 4 years is 57.4% +/- 9.1% (SE). Hematologic, mucosal, and infectious toxicities were seen in 12%, 9%, and 5% of intensive MTX/MP courses, but were generally mild. CONCLUSION: Combined data from this and our previous trial suggest that intensive MTX/MP may produce long-term disease-free survival in 70 to 75% of children with B-lineage ALL. In comparison to other intensive regimens, intensive MTX/MP is easy to administer, effective, and relatively nontoxic. If patients at risk for failure of MTX/MP can be identified prospectively, more aggressive regimens could be restricted to this smaller (25% to 30%) cohort.

Adolescent↗
PubMed1994

Phase II investigational window using carboplatin, iproplatin, ifosfamide, and epirubicin in children with untreated disseminated neuroblastoma: a Pediatric Oncology Group study.

PURPOSE: Children less than 1 year of age with metastatic neuroblastoma NB are at high risk of death. The need to identify new and effective chemotherapy agents is clear. A study was conducted by the Pediatric Oncology Group (POG) to determine the efficacy and safety of administering two courses of a single phase II agent before conventional treatment as a means to evaluate new agents in this setting. PATIENTS AND METHODS: One hundred seventy-three eligible patients more than 1 year of age with disseminated neuroblastoma received two courses of one of the following: ifosfamide (IFOS) 2 g/m2/d for 4 days intravenously (IV) plus mesna; carboplatin (CARB) 560 mg/m2 i.v. over 1 hour; iproplatin (CHIP) 325 mg/m2 IV over 2 hours; or epirubicin (EPIR) 90 mg/m2 i.v. push. Following evaluation for response and toxicity, eligible patients were randomized to receive either cisplatin 90 mg/m2 i.v. on day 1, etoposide 200 mg/m2 i.v. on day 3, cyclophosphamide 150 mg/m2/d orally on days 7 to 13, doxorubicin 35 mg/m2 i.v. on day 14 (CECA), or cisplatin 40 mg/m2 IV on days 1 to 5 and etoposide 200 mg/m2 i.v. on days 2 to 4 alternating at 3-week intervals with cyclophosphamide 150 mg/m2/d orally on days 1 to 7 and doxorubicin 35 mg/m2 IV on day 8 (HDP/VP/CA). An additional 86 patients were randomized to receive either CECA or HDP/VP/CA without initial phase II therapy. RESULTS: After phase II therapy, only 20% of patients experienced grade 3/4 hematopoietic toxicity. No toxic deaths occurred. Objective response rates (partial responses [PRs] plus minor responses [MRs]) following IFOS, CARB, CHIP, and EPIR were 70%, 77%, 67%, and 26%, respectively. Following phase III treatment, there was no statistically significant difference in rates of complete response (CR)/PR or progressive disease (PD), or in time to PD of patients who participated in the phase II window versus those who received only CECA or HDP/VP/CA. CONCLUSION: IFOS, CARB, and CHIP are efficacious in neuroblastoma, are well tolerated, and should be incorporated into primary treatment regimens. Combination regimens using these agents may be possible, since most repeat courses were given within 2 weeks. Administering phase II therapy to untreated patients with high-risk tumors provides a unique and sensitive method to assess new agents without compromising patient outcome.

Adolescent↗
PubMed1993

Sites of predilection in recurrent respiratory papillomatosis.

Florid and widespread respiratory papillomatosis is a devastating disorder in a subset of patients with recurrent respiratory papillomatosis, and it poses a major dilemma for the patient and the surgeon. Contrary to common belief, the distribution of papilloma lesions is not random, but follows a predictable pattern, with lesions occurring at anatomic sites in which ciliated and squamous epithelia are juxtaposed. The predominant sites of disease in recurrent respiratory papillomatosis are the limen vestibuli, the nasopharyngeal surface of the soft palate, the midzone of the laryngeal surface of the epiglottis, the upper and lower margins of the ventricle, the undersurface of the vocal folds, the carina, and bronchial spurs. These sites have the common histologic feature of a squamociliary junction. Papillomata also occur at the tracheostomy tract and at the midthoracic trachea in patients with tracheostomies. At the latter sites, abrasion injury to ciliated epithelium heals with metaplastic squamous epithelium and creates an iatrogenic squamociliary junction. The apparent preferential localization of papilloma at squamociliary junctions has at least 2 implications: first, that detection of occult asymptomatic papillomata is enhanced by careful examination of squamociliary junctions, and, second, that iatrogenic papilloma "implantation" is preventable by avoiding injury to nondiseased squamous and ciliated epithelia.

Cilia↗
PubMed1993

Phase I clinical trial of recombinant human tumor necrosis factor in children with refractory solid tumors: a Pediatric Oncology Group study.

PURPOSE: A phase I study was undertaken to determine the toxicity and maximum-tolerated dose (MTD) of recombinant human tumor necrosis factor (rTNF) in children. PATIENTS AND METHODS: Twenty-seven patients with recurrent or refractory solid tumors were enrolled on the study. rTNF was administered daily for 5 days by 30-minute intravenous (IV) infusion, and doses were escalated in cohorts of three to six patients. Courses were repeated after a 9-day rest period, if toxicity was tolerable. Daily doses ranged from 100 to 350 micrograms/m2. RESULTS: Most courses were associated with grade I/II fever, rigors, nausea, or vomiting. Three patients experienced moderate dyspnea that responded to supplemental oxygen. All abnormalities resolved on discontinuation of the infusion. One patient had a cardiac arrest 90 minutes after receiving the first dose of rTNF and died 10 days later of related complications. In two other patients, rTNF was discontinued due to persistent grade IV hypotension. Toxicities were not consistently related to dose and no cumulative effects were noted. The dose-limiting toxicity was transient hepatic dysfunction, which occurred in three of six patients receiving 350 micrograms/m2; this toxicity was rapidly reversed on discontinuation of the rTNF. One patient, whose non-Hodgkin's lymphoma had recurred after bone marrow transplantation, had a partial response. Disease was stabilized in two patients. CONCLUSION: We recommend that phase II testing proceed at a dose of 300 micrograms/m2/d on the schedule described.

Adolescent↗
PubMed1992

The use of nuclear morphometry to predict response to therapy in Wilms' tumor.

Using nuclear morphometric analysis, a retrospective study was made of 27 patients with Wilms' tumor. The blinded group consisted of 17 patients with Stage I and II favorable-histology Wilms' tumors who did not respond to therapy and ten patients with Stage III and IV favorable-histology Wilms' tumors who did respond. In this complex group of patients, multivariate analysis (with several morphologic descriptors) was used to predict which patients responded to therapy. No single-shape descriptor predicted the response to therapy (P greater than 0.5). However, three shape descriptors: maximum ellipticity (ME), standard error of bending energy (SEBE), and the range of chain code-maximum peak (RCCM), with the multivariate formula of (1131 x SEBE) + (-7 x ME) + (50 x RCCM) + 7.18, separated the two groups (P less than 0.004). This result was statistically significant. Using this multivariate equation and a cutoff value of 0.6 units, this test yielded a sensitivity of 94% and a specificity of 70%. This result, in a complex group of patients, suggests that nuclear morphometry may be useful in the initial assessment of patients with Wilms' tumor and warrants further analysis.

Cell Nucleus↗
PubMed1992

Antibody response to human papillomavirus (HPV) type 11 in children with juvenile-onset recurrent respiratory papillomatosis (RRP).

We previously established, using an ELISA, the presence of specific antibodies directed at human papillomavirus (HPV) type 11 virions in the sera of patients with condylomata acuminata, mostly a disease of young adults that, like recurrent respiratory papillomatosis (RRP), is caused by two closely related HPVs, types 6 and 11. The present study was done to investigate if children with RRP can make viral-specific antibodies to an infection that is acquired at birth. Using the same ELISA, we studied the sera of 32 children with biopsy-documented juvenile-onset RRP and compared them to the sera of 31 control children. The median (and interquartile range) of the OD values in the controls and the cases was 0.078 (0.003, 0.101) and 0.230 (0.063, 0.725), respectively, a statistically significant difference (P = 0.001). Among the cases, there was no difference in seroreactivity between children with HPV-11-induced RRP and those with HPV-6-induced RRP (P = 0.31). Since HPV-11 viral particles do bind to the ELISA plate and remain intact and accessible to antibodies, we conclude that children with RRP, like adults with condylomata acuminata, develop antibodies directed at HPV-11 virions.

Antibodies, Viral↗
PubMed1992

Systemic lupus erythematosus in a child receiving long-term interferon therapy.

Systemic lupus erythematosus (SLE) developed in a 10 1/2-year-old white boy with juvenile laryngeal papillomatosis who had been treated with interferon alfa-n1 for 7 years. His age, gender, and fast recovery after discontinuation of interferon therapy and institution of appropriate treatment for SLE are compatible with a diagnosis of drug-induced SLE. Autoimmune disorders may occur as a complication of interferon therapy.

Autoimmune Diseases↗
PubMed1991

Gallium-67 scans as an adjunct to computed tomography scans for the assessment of a residual mediastinal mass in pediatric patients with Hodgkin's disease. A Pediatric Oncology Group study.

This study determines the utility of gallium-67 (Ga-67) scintigraphs as an adjunct to computed tomography (CT) scans for the assessment of residual mediastinal masses in children and adolescents with advanced-stage Hodgkin's disease. At diagnosis 42 patients with CT scan-documented mediastinal disease had a Ga-67 scan performed. Thirty-four of 42 patients (81%) had gallium-avid mediastinal lesions, whereas in eight (19%), the Ga-67 scan was negative. At the completion of eight cycles of therapy of Mustargen (mechlorethamine), Oncovin (vincristine), procarbazine, prednisone (MOPP) alternating with doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD), 21 of 34 patients with initially positive Ga-67 scans had them repeated; 18 of 21 converted to negative results, and three remained positive. In 11 of 18 patients, the loss of gallium avidity was consistent with a negative mediastinal CT scan. In seven, although the gallium scan was negative, the CT scan remained positive; all seven patients had a mediastinal biopsy of suspected residual disease and in all seven the biopsy results were negative for Hodgkin's disease. These preliminary results in a small cohort of patients demonstrate that Ga-67 scans may be of benefit in evaluating residual mediastinal masses in patients with Hodgkin's disease.

Adolescent↗
PubMed1991

Pediatric testicular tumors: the Johns Hopkins experience.

Testicular neoplasms constitute 1 percent of all childhood malignancies and rank eighth in childhood cancer mortality. From 1970 to 1988, 25 testicular tumors in children eighteen years and under were seen. The majority of the patients were white (88%). Pathologic analysis of the tumors revealed that 68 percent were germinal and 32 percent were nongerminal. Staging was undertaken in all patients with serum markers, chest x-ray film, and computerized tomography scans or lymphangiography. All patients underwent radical orchiectomy, and further therapy was given dependent on tumor type and stage. The survival among this cohort was excellent, with only 3 patients succumbing to their disease. Detailed results of treatment, and approaches to avoid excess treatment morbidity are reviewed.

Adolescent↗
PubMed1991

A comparison of induction and maintenance therapy for acute nonlymphocytic leukemia in childhood: results of a Pediatric Oncology Group study.

Two hundred fifty-six children with previously untreated acute nonlymphocytic leukemia (ANLL) were evaluated on a Pediatric Oncology Group (POG) phase III randomized trial of both induction and continuation chemotherapies. Induction therapy compared vincristine, cytarabine, and dexamethasone (VADx) with daunorubicin, cytarabine, and thioguanine (DAT). The complete remission (CR) rate using DAT was superior (82% v 61%, P = .02). Postremission therapy consisted of either "standard" two-cycle therapy or a more intensive four-cycle regimen given for 2 years. Overall, there was no difference in outcome for patients randomized to either continuation regimen. The overall complete continuous remission rate (CCR) for the "best" induction/continuation therapy combination at 2 years was .50 (SE = .06), at 3 years was .35 (.04), and at 4 years was .34 (.05). Analysis of selected clinical and laboratory parameters demonstrated differences in induction responses favoring DAT induction but did not impact eventual disease-free survival. There were two subgroups of patients who responded better to four-cycle continuation therapy. These were patients with French-American-British (FAB) M1/M2 (2-year CCR was .20 v .44, P = .01) and patients older than 10 years at diagnosis (.32 v .62, P = .004).

Agranulocytosis↗