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Biomedical subjects

C Rosenfeld

Publications and source records attributed to C Rosenfeld.

At least 19 recordsLinked to original sources

New limit on the neutrinoless betabeta decay of 130Te.

We report the present results of CUORICINO, a search for neutrinoless double-beta (0nu betabeta) decay of 130Te. The detector is an array of 62 TeO2 bolometers with a total active mass of 40.7 kg. The array is cooled by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons, operated at approximately 8 mK in the Gran Sasso Underground Laboratory. No evidence for (0nu betabeta) decay was found and a new lower limit, T(1/2)(0nu) > or = 1.8 x 10(24) yr (90% C.L.) is set, corresponding to [m(nu)] < or = 0.2 to 1.1 eV, depending on the theoretical nuclear matrix elements used in the analysis.

Journal Article↗

Right-left correlation of the sympathetically induced fluctuations of photoplethysmographic signal in diabetic and non-diabetic subjects.

Photoplethysmography (PPG) records the cardiac-induced changes in tissue blood volume by light-transmission measurements. The baseline and amplitude of the PPG signal show very low-frequency (VLF) spontaneous fluctuations, which are mediated by the sympathetic nervous system, and high correlation between right and left extremities of healthy subjects. As sympathetic neuropathy is one of the diabetic complications, the right-left correlation of the PPG fluctuations was examined in diabetic patients. The PPG signal was simultaneously measured in the two index fingers and the two second toes of 35 diabetic patients and 33 non-diabetic subjects. For each PPG pulse, the baseline and amplitude were determined, and the right-left correlation coefficients of the VLF fluctuations in the baseline and amplitude were derived. The VLF fluctuations in the baseline showed high right-left correlation, both for fingers (0.93 +/- 0.05) and toes (0.93 +/- 0.06), for the non-diabetic subjects, and significantly lower correlation (0.78 +/- 0.22 and 0.84 +/- 0.17, respectively) for the diabetic patients. Similar results were obtained for the amplitude VLF fluctuations. The right-left correlation coefficients for diabetic patients decreased with the disease duration for the toe baseline and toe amplitude fluctuations and correlated with heart rate response to deep breathing for the finger baseline and toe amplitude fluctuations. The right-left correlation coefficients of the PPG fluctuations provide a simple and convenient means for assessing the adequacy of the sympathetic nervous system function.

Adult↗

Prevalence of sexual dysfunctions in Argentina.

The objective of this study consisted in assessing the prevalence of erectile dysfunction (ED) and other sexual dysfunctions in a group of men who attended a prostate awareness week campaign. In total, 2715 men attended to 'Semana de la Prostata 2001' campaign and received an additional questionnaire on sexual health. The prevalence of ED, desire and ejaculatory disorders was of 41.7, 33.8 and 49.3%, respectively; however, not all of them lived these difficulties as a real sexual problem because only 918 men (37.8%) acknowledged having 'any sexual difficulty'. Only 13.7% of the attendees consulted a physician for this reason in the past. This first Argentinean study proves the high prevalence of sexual dysfunctions in our population.

Adult↗

WT1 in acute leukemia, chronic myelogenous leukemia and myelodysplastic syndrome: therapeutic potential of WT1 targeted therapies.

Among clinicians, initial awareness of the Wilms' tumor gene was limited mostly to pediatric oncologists. Almost a decade ago, overexpression of Wilms' tumor 1 (WT1) was observed in adult acute leukemia. Subsequent studies indicated that WT1 overexpression occurs in most cases of acute myelogenous leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS). Limited tissue expression of WT1 in adults suggests that WT1 can be a target for leukemia/MDS therapy. WT1 expression in stem/progenitor cells remains unsettled. However, lack of progenitor cell suppression by WT1 antisense or WT1-specific cytotoxic T cells provide some assurance that WT1 expression in progenitor cells is minimal or absent. Immunotherapy-based WT1 approaches are furthest along in preclinical development. WT1-specific cytotoxic lymphocytes can be generated from normals and leukemic patients. In mice, WT1 vaccines elicit specific immune responses without evidence of tissue damage. In this paper, we review studies validating the immunogenicity of WT1 and propose that leukemia and MDS may be a good clinical model to test the efficacy of a WT1 vaccine.

Acute Disease↗

Interactions of rat brain acetylcholinesterase with the detergent Triton X-100 and the organophosphate paraoxon.

Inhibition of the critical enzyme acetylcholinesterase (E.C. 3.1.1.7) with subsequent cholinergic crisis is the mechanism of acute toxicity of the organophosphorus insecticides (B. E. Mileson et al., 1998, Toxicol. Sci.41, 8-20). Consequently, measurement of acetylcholinesterase activity is important for evaluating the mammalian toxicity of this commonly used class of insecticides. While mammalian acetylcholinesterase activity has often been determined in tissue homogenates in the presence of the nondenaturing detergent Triton X-100 at a concentration of 1%, the potential actions of this detergent on the activity of this critical enzyme are not understood. In the current study, homogenization of rat brain in buffer containing 1% Triton X-100 slightly elevated the (app)V(max) for hydrolysis of acetylthiocholine, without affecting the (app)K(m) or the (app)K(ss). However, the presence of both 1% Triton X-100 and paraoxon (at concentrations of 5 nM-100 nM) resulted in complex kinetic interactions with acetylcholinesterase, as evidenced by a curvilinear secondary plot for determination of the (app)k(i). These results suggest that measurement of acetylcholinesterase activity in the presence of up to 1% Triton X-100, but in the absence of oxon, should pose no problems with regard to data interpretation, provided it is recognized that the detergent slightly elevates activity. However, measurement of acetylcholinesterase activity after enzyme was exposed simultaneously to Triton X-100 and oxon could be problematic. Caution is warranted when interpreting data where acetylcholinesterase activity was determined under such conditions since in the presence of 1% Triton X-100, the capacity of oxon to inhibit acetylcholinesterase might change as a function of oxon levels.

Acetylcholine↗

Is myelodysplastic related acute myelogenous leukemia a distinct entity from de novo acute myelogenous leukemia? Potential for targeted therapies.

Acute myelogenous leukemia (AML) can be separated by whether the presentation was proceeded by a myelodysplastic (MDS related AML) or developed de novo (dAML). Clinically, MDS related AML (mAML) has been considered to have a worse prognosis that dAML. The objective of this literature review was to identify unique biologic features of mAML. Compared to dAML, mAML is characterized by an altered immunophenotype (increased frequency of CD34, CD11b and CD25), lack of leukemic progenitor cell suppression due to TGFbeta1, increased bcl-2 expression, presence of inducible nitric oxide synthase, lower levels or mrp transcripts and increased expression of p53. Possible interpretations of these differences between mAML and dAML are presented. Implications for mAML directed therapy are discussed.

Diagnosis, Differential↗

Transplantation of CD34+ peripheral blood cells selected using a fully automated immunomagnetic system in patients with high-risk breast cancer: results of a prospective randomized multicenter clinical trial.

Tumor contamination of autologous peripheral blood stem/progenitor cell grafts occurs in a substantial proportion of high-risk breast cancer patients, and the possibility that such contamination may contribute to relapse has focused attention on methods for removal of the contaminating cells prior to transplantation. One such approach is positive selection of CD34+ cells. A fully automated immunomagnetic cell selection system has recently been introduced to facilitate the positive selection process. A multicenter randomized clinical trial was designed to evaluate the capacity of CD34+ cells isolated using the fully automated system to support prompt hematopoietic reconstitution following high-dose chemotherapy in high-risk breast cancer patients, as well as to assess the safety and tolerability of the CD34+ cell transplants. In recipients of isolated CD34+ cells, the median time to an absolute neutrophil count > or =500/microl was 10 days, a value identical to that observed in patients receiving unfractionated apheresis collections. In the isolated CD34+ cell recipients median time to a platelet count > or =20 000/microl was 12 days, compared with 10 days in the unfractionated cell group. There were no statistically significant differences between the groups in median time to neutrophil or platelet engraftment. Infusion of autologous cells was well tolerated by the study groups. There were no inter-group differences in the incidence of infections, need for platelet transfusions, or duration of hospitalization. Isolated CD34+ cells were high in purity and sufficient in number for use in autologous transplantation. The fully automated immunomagnetic cell selection system affords an efficient and time-saving option for isolation of CD34+cells to be used as autologous grafts in high-risk breast cancer patients, and the isolated CD34+ cells support undelayed hematopoietic reconstitution.

Adult↗

A hypothesis for the pathogenesis of myelodysplastic syndromes: implications for new therapies.

To guide development of new clinical strategies, a review of recent investigations in the pathobiology of MDS was performed. Articles were identified through a Medline search. Studies, including reviews, are cited in the references. A multistep pathogenesis is proposed. (1) Targeted injury or mutation within hemopoietic stem cells may be followed by an immunologic response adversely affecting progenitor survival. (2) Accelerated proliferation and premature death of marrow cells is amplified by apoptogenic cytokines (TNF-alpha, Fas ligand). (3) Establishment of an abnormal clone associated with telomere shortening. (4) Disease progression associated with loss of tumor suppressor activity. Opportunities for therapeutic interventions are possible at each step. Comparisons between the proposed pathogenesis of MDS and severe aplastic anemia (SAA) are also presented. Leukemia (2000) 14, 2-8.

Disease Progression↗

High-dose chemotherapy followed by reinfusion of selected CD34+ peripheral blood cells in patients with poor-prognosis breast cancer: a randomized multicentre study.

Seventy-one patients with poor-prognosis breast cancer were enrolled after informed consent in a multicentre randomized study to evaluate the use of selected peripheral blood CD34+ cells to support haematopoietic recovery following high-dose chemotherapy. Patients who responded to conventional chemotherapy were mobilized with chemotherapy (mainly high-dose cyclophosphamide) and/or recombinant human granulocyte colony-stimulating factor (rhG-CSF). Patients who reached the threshold of 20 CD34+ cells per microl of peripheral blood underwent apheresis and were randomized at that time to receive either unmanipulated mobilized blood cells or selected CD34+ cells. For patients in the study arm, CD34+ cells were selected from aphereses using the Isolex300 device. Fifteen patients failed to mobilize peripheral blood progenitors and nine other patients were excluded for various reasons. Forty-seven eligible patients were randomized into two comparable groups. CD34+ cells were selected from aphereses in the study group. Haematopoietic recovery occurred at similar times in both groups. No side-effect related to the infusion of selected cells was observed. The frequency of epithelial tumour cells in aphereses was low (8 out of 42 evaluated patients), as determined by immunocytochemistry. We conclude that selected CD34+ cells safely support haematopoietic recovery following high-dose chemotherapy in patients with poor-prognosis breast cancer.

Adult↗

Allogeneic blood cell transplantation without posttransplant colony-stimulating factors in patients with hematopoietic neoplasm: a phase II study.

PURPOSE: There is limited experience with allogeneic blood cell transplantation (BCT). In an earlier pilot study, the combination of bone marrow and blood did not produce severe acute graft-versus-host disease (GVHD). We now report the results of a phase II study using blood stem cells alone in 19 patients. PATIENTS AND METHODS: The median age was 40 years. All patients had hematopoietic malignancies and received transplants from HLA-identical sibling donors. GVHD prophylaxis consisted of cyclosporine plus prednisone. Posttransplant colony-stimulating factors were not administered. Donors were mobilized with subcutaneous granulocyte colony-stimulating factor (G-CSF; 16 microg/kg/d) for 5 days. Apheresis was performed on 2 consecutive days. RESULTS: The median cell content of the two apheresis was 11.9 x 10(8) WBC/kg, 3.2 x 10(8) CD3/kg, and 8.3 x 10(6) CD34/kg. The median time to achieve an absolute neutrophil count (ANC) > or = 500/microL was 13 days, and 14 days to a platelet count > or = 50,000/microL. All patients engrafted. Platelet recovery was faster in marrow historic control groups. Blood cells in all tested cases contained more than 95% donor cells on day 30. The actuarial incidence of acute GVHD was 37%, and 13% for grade II-IV GVHD. Limited, corticosteroid responsive, chronic GVHD developed in 33% of assessable patients. At a median follow-up of 192 days, actuarial survival was 75%. CONCLUSION: Transplantation of a high number of stem cells may lead to rapid engraftment without the use of posttransplant colony-stimulating factors. GVHD does not appear to be more severe than in similarly treated patients undergoing bone marrow transplantation. For allogeneic transplantation, mobilized blood cell collections are an alternative to bone marrow collections.

Adult↗

A phase I trial of recombinant human interleukin-6 in patients with myelodysplastic syndromes and thrombocytopenia.

To evaluate the hematologic effects of recombinant human interleukin-6 (rhIL-6, Escherichia coli, SDZ ILS 969, IL-6), and determine its toxicity profile, we performed a phase I trial of IL-6 in 22 patients with various myelodysplastic syndromes (MDS), platelet counts < 100,000/microL, and < 5% bone marrow (BM) blasts. Patients received one of four doses of IL-6 (1.0, 2.5, 3.75, and 5.0 micrograms/kg/d) as a subcutaneous injection on day 1, followed by a 7-day wash-out period, and then 28 days of IL-6 therapy. Dose-limiting toxicities of fatigue, fever, and elevated alkaline phosphatase were seen at 5.0 micrograms/kg/d; the maximum tolerated dose was 3.75 micrograms/kg/d. All patients experienced at least grade II fever and all had an increase in acute phase proteins. Eight patients (36%) experienced at least a transient improvement in platelet counts; three fulfilled the criteria for response, whereas five others had clinically significant increases that failed to meet response criteria. Various IL-6-related toxicities prevented more than three patients from receiving maintenance therapy. Two of the three patients who received maintenance IL-6 therapy had a persistent increase in platelet counts, during 3 and 12 months of IL-6 therapy, respectively. Laboratory studies indicated that IL-6 increased the frequency of higher ploidy megakaryocytes but did not significantly increase the number of assayable megakaryocytic progenitor cells, suggesting that IL-6 acts as a maturational agent rather than a megakaryocyte colony-stimulating factor. Although IL-6 therapy can promote thrombopoiesis in some MDS patients, its limited activity and significant therapy-related toxicity preclude its use as a single agent in this patient population. Further studies, combining low doses of IL-6 with other hematopoietic growth factors, are underway.

Acute-Phase Proteins↗

Allogeneic transplantation combining mobilized blood and bone marrow in patients with refractory hematologic malignancies.

BACKGROUND: Mobilized blood stem cells have been used successfully in autologous transplant recipients to reduce the complications of pancytopenia due to dose-intensive chemotherapy. Reports of cytokine-mobilized blood progenitor cells in allogeneic transplant recipients are rare. STUDY DESIGN AND METHODS: This is a pilot trial of six patients. Patients with advanced hematologic malignancy received bone marrow (median total 2.6 x 10(8) mononuclear cells/kg) followed by four daily transfusions of blood (median total 9.5 x 10(8) mononuclear cells/kg) from HLA-matched sibling donors who were mobilized with recombinant human granulocyte-colony-stimulating factor (5 micrograms/kg/day subcutaneously for 5 days). All patients received cyclosporine and prednisone for graft-versus-host disease (GVHD) prophylaxis. RESULTS: An absolute neutrophil count greater than 500 per mm3 was achieved on Day 12, and platelet transfusion independence was achieved on Day 16. The median day of hospital discharge was Day 23 after transplant. All patients achieved 100-percent donor cell engraftment. Acute > or = Grade III GVHD did not develop in any patients, but all patients developed Grade I (n = 4) or Grade II (n = 2) acute GVHD. Chronic extensive GVHD developed in four of six patients. One patient died of pneumonia 263 days after transplant while undergoing immune-suppressive therapy for chronic GVHD. CONCLUSION: The transfusion of blood stem cells in patients undergoing allogeneic bone marrow transplant is well tolerated soon after transplant, but the development of chronic GVHD may limit the general usage of unmanipulated blood stem cells.

Adult↗

Pentoxifylline and ciprofloxacin in patients with myelodysplastic syndrome. A phase II trial.

Tumor necrosis factor (TNF) inhibits hematopoietic cell proliferation. The combination of pentoxifylline (PTX) and ciprofloxacin (Cipro) has been previously shown to reduce circulating serum levels of TNF. In this Phase II trial 14 patients with advanced myelodysplastic syndrome were treated with PTX (2,000 mg/day) and Cipro (1,000 mg/day) in order to determine tolerability and effect on peripheral blood cell counts, progenitor cell responsiveness to cytokines and circulating serum levels of interleukin-6 (IL6) and TNF. Toxicity attributed to PTX and Cipro were limited to nausea in 4 patients. Peripheral blood cell counts, platelet transfusion requirements and red blood cell transfusion requirements did not change during administration of PTX and Cipro (daily for 28 days). Marrow progenitor cells of patients entered into trial were less responsive to stimulation with cytokines in vitro at baseline and during the trial compared to normal volunteers. Eight patients had elevated IL6 levels before treatment with PTX and Cipro these levels did not change during therapy. Five patients had elevated TNF levels at baseline. There was a suggestion of decreased TNF levels during treatment with PTX and Cipro (P = .09). In conclusion, PTX and Cipro was well tolerated but no evidence of efficacy was observed.

Adult↗

Phase I study of recombinant interleukin-1 beta in patients undergoing autologous bone marrow transplant for acute myelogenous leukemia.

A phase I trial was conducted with recombinant human interleukin-1 beta (rhIL-1 beta) in patients undergoing autologous bone marrow (BM) transplantation for acute myelogenous leukemia. rhIL-1 beta was administered at 3 dose levels (0.01, 0.02, 0.05 microgram/kg) by 30 minute intravenous infusion once a day beginning on the day of BM infusion and continuing for a total of 5 doses. A total of 17 patients were entered on the trial, and their results were compared with those of 74 consecutive historical control patients that did not receive colony stimulating factors. Moderate toxicity was observed in all patients. All 17 patients developed fever and chills within 30 minutes after initiation of rhIL-1 beta, and hypotension was observed in 14 of 17 patients 5 to 8 hours after the infusion. A total of 30% of patients required therapy (normal saline or dopamine) for treatment of hypotension. Therefore, dose escalation was discontinued at the 0.05 microgram/kg dose level. The number of days required to achieve an absolute neutrophil count greater than 500 mL in patients who received rhIL-1 beta was less than in historical patients (25 v 34; P = .02). This appeared to correlate with a reduced incidence of infection between days 0 and 28 after BM infusion (12% v 23%; P = .049). Median bilirubin, median creatinine, platelet recovery, and days in the hospital were not different between study patients and historical controls. Survival of patients who received rhIL-1 beta compared with that of historical patients was improved (30% v 20%; P = .04). These possible benefits were achieved at the cost of moderate toxicity during rhIL-1 beta administration.

Adolescent↗