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Biomedical subjects

M Fleisher

Publications and source records attributed to M Fleisher.

At least 19 recordsLinked to original sources
PubMed2006

Results of a phase I/II trial adding carmustine (300 mg/m2) to melphalan (200 mg/m2) in multiple myeloma patients undergoing autologous stem cell transplantation.

Autologous stem cell transplantation (SCT) with high-dose melphalan (HDM, 200 mg/m2) is the most effective therapy for multiple myeloma. To determine the feasibility of combining carmustine (300 mg/m2) with HDM, we enrolled 49 patients with previously treated Durie-Salmon stage II/III myeloma (32M/17W, median age 53) on a phase I/II trial involving escalating doses of melphalan (160, 180, 200 mg/m2). The median beta2-microglobulin was 2.5 (0-9.3); marrow karyotypes were normal in 88%. The phase I dose-limiting toxicity was > or =grade 2 pulmonary toxicity 2 months post-SCT. Other endpoints were response rate and progression-free survival (PFS). HDM was safely escalated to 200 mg/m2; treatment-related mortality was 2% and > or =grade 2 pulmonary toxicity 10%. The complete (CR) and near complete (nCR) response rate was 49%. With a median post-SCT follow-up of 2.9 years, the PFS and overall survival (OS) post-SCT were 2.3 and 4.7 years. PFS for those with CR or nCR was 3.1 years while for those with stable disease (SD) it was 1.3 years (P=0.06). We conclude that carmustine can be combined with HDM for myeloma with minimal pulmonary toxicity and a high response rate.

Adult↗
PubMed2005

Hematopoietic stem cell mobilization with intravenous melphalan and G-CSF in patients with chemoresponsive multiple myeloma: report of a phase II trial.

Multiple myeloma (MM) is an incurable hematologic malignancy for which autologous hematopoietic stem cell transplantation (HCT) is a standard therapy. The optimal method of stem cell mobilization is not defined. We evaluated intravenous melphalan (60 mg/m2), the most effective agent for MM, and G-CSF (10 microg/kg/day) for mobilization. End points were safety, adequacy of CD34+ collections, MM response, and contamination of stem cell components (SCC). In total, 32 patients were mobilized. There were no deaths or significant bleeding episodes; 14 patients (44%) required hospitalization for neutropenic fever. Median days of grade 3 or 4 neutropenia or thrombocytopenia were 7 (2-20) and 8 (3-17). Median mobilization days, CD34+ cells/kg and total leukaphereses were 16 (12-30), 12.1 million (2.6-52.8), and 2 (1-5) respectively. Four patients (12.5 %) failed to achieve the target of 4 million CD34+ cells/kg in five leukaphereses. Reduction in myeloma was seen in 11 patients (34%) with 3 (9%) achieving complete response; 15 (47%) maintained prior responses. Estimated MM contamination per SCC (N=48) was 0.0009% (range 0-0.1) and 0.21 x 10(4) cells per kg (range 0-41.2). Increased contamination was associated with increased patient age. This strategy for mobilization is feasible, frequently requires hospitalization and transfusion, and controls disease in most patients.

Adult↗
PubMed2004

Systemic AL amyloidosis due to non-Hodgkin's lymphoma: an unusual clinicopathologic association.

Systemic AL amyloidosis (AL) is a disorder in which light chains form fibrillar deposits, leading to organ dysfunction and death. Rarely, AL has been associated with non-Hodgkin's lymphoma (NHL), although this association has not been well characterized. We report a series of six patients with AL associated with NHL, primarily lymphoplasmacytic lymphoma. Organ involvement was variable, with frequent bulky lymphadenopathy and visceral cavity deposits, but no cardiac involvement. Positron emission tomography scans were negative. Bone marrow and lymph node biopsies showed a mixed population of CD20+ lymphoid and CD138+ plasma cells. Serum free light chains were elevated, and correlated with response to therapy. Immunoglobulin light chain variable region (Ig VL) germline gene use was typical for AL, reflecting previously observed correlations between germline gene use and organ tropism. Five patients received rituximab-based therapies with two responses. Two patients underwent autologous stem cell transplantation with one complete haematological response. Four patients survive at 10-132 months from diagnosis. AL with NHL has distinctive clinical features but employs the same Ig VL gene repertoire as AL with clonal plasma cell dyscrasias. Serial serum free light chain levels are useful for tracking response to therapy. Treatments aimed at both lymphoid and plasma cell components appear warranted.

Aged↗
PubMed2001

Radioiodine ablation of thyroid remnants after preparation with recombinant human thyrotropin.

Radioiodine ablation (RA) of normal thyroid remnants after thyroidectomy for differentiated thyroid carcinoma improves the sensitivity of subsequent radioiodine scans and serum thyroglobulin measurements for detection of residual thyroid carcinoma. Local cancer recurrences are also lower after RA. One standard preparation for RA involves rendering the patient hypothyroid in order to stimulate endogenous thyrotropin (TSH) secretion and sodium iodide symporter (NIS) activity. An alternative approach is to prescribe thyroxine after thyroidectomy and to stimulate NIS with exogenous recombinant human thyrotropin (rhTSH). This latter approach was used in 10 patients at our medical center. Complete resolution of all visible 131I thyroid bed uptake was achieved in all when follow-up scans were performed 5 to 13 months later. This approach has the potential to successfully ablate thyroid remnants without the need to induce hypothyroidism.

Adult↗
PubMed2001

Diltiazem treatment does not alter renal function after thoracic surgery.

BACKGROUND: There are conflicting reports on the effects of diltiazem treatment on renal function in surgical patients. We sought to determine whether diltiazem treatment alters renal function in patients undergoing major thoracic surgery. METHODS: In a prospective study, 330 patients scheduled for elective thoracic surgery received either IV diltiazem (n = 167) or placebo (n = 163) immediately after the operation and orally thereafter for 14 days in an effort to prevent postoperative atrial arrhythmias. Serum creatinine and BUN levels were compared before and during the first postoperative week. RESULTS: Patients treated with diltiazem were similar to control subjects in terms of age (mean +/-SD, 66 +/- 10 years vs 67 +/- 10 years, respectively), baseline serum creatinine or BUN levels, prevalence of comorbid conditions, and surgical characteristics. During the first 5 postoperative days, the two groups did not differ in terms of serum creatinine or BUN levels. The incidence of renal failure was 0.6% in the diltiazem group and 1.2% in the placebo group (difference was not significant). There was no difference in the length of hospitalization or mortality rate. CONCLUSIONS: In patients without renal disease who are undergoing elective thoracic surgery, prophylactic diltiazem treatment did not alter postoperative renal function.

Aged↗
PubMed2000

Perioperative alterations in plasma endothelin-1 and echocardiographic correlates of right heart function.

OBJECTIVE: To determine whether greater changes in plasma endothelin-1 (ET-1) concentrations and right ventricular systolic pressure occur after major thoracic surgery than after major abdominal operations. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Patients undergoing elective thoracotomies (n = 12) or laparotomies (n = 10). INTERVENTIONS: ET-1 was measured from blood obtained before anesthesia and again on postoperative days 1, 2, 3, and 5 (or 6). Transthoracic echocardiography was performed before surgery and on postoperative day 2 to evaluate right-sided heart function. MEASUREMENTS AND MAIN RESULTS: After abdominal and thoracic surgery, systemic and estimated pulmonary vascular pressures were normal in both groups and unaffected by surgery. Plasma ET-1 concentrations decreased from baseline values during the first postoperative week with no differences between the groups. CONCLUSIONS: In patients without organic heart disease, plasma ET-1 levels do not increase in response to major abdominal or thoracic surgery. Whether or not plasma ET-1 concentrations are elevated in patients developing clinically significant postoperative pulmonary hypertension requires further study.

Aged↗
PubMed2000

Multicenter study of whole-blood creatinine, total carbon dioxide content, and chemistry profiling for laboratory and point-of-care testing in critical care in the United States.

OBJECTIVES: To introduce a creatinine biosensor and a total carbon dioxide content (TCO2) method for whole-blood measurements, to evaluate the clinical performance of a new transportable analyzer that simultaneously performs these two and six other tests (Na+, K+, Cl-, glucose, urea nitrogen, and hematocrit), and to assess the potential of the new analyzer for point-of-care testing in critical care by comparing results obtained by nonlaboratory personnel and by medical technologists. DESIGN: Multicenter sites compared whole-blood measurements with the transportable analyzer to plasma measurements from the same specimens with local reference instruments. One site compared whole-blood results produced by nonlaboratory personnel vs. medical technologists and evaluated day-to-day and within-day precision at the point of care. SETTINGS AND PATIENTS: Four medical centers in the United States. Venous and arterial specimens from 710 critically ill patients with a variety of diagnoses. Point-of-care testing in the emergency room and operating room. RESULTS: The linear regression analyses at the four medical centers showed the following: creatinine (a) slope, 0.91 to 1.22, (b) y intercept, -0.07 to 0.15 mg/dL, and (c) r2, 0.77 to 1.00; and TCO2: (a) slope, 0.64 to 1.00, (b) y intercept, 1.36 to 9.6 mmol/L, and (c) r2, 0.52 to 0.72 (yi, whole-blood analyses; xi, plasma reference measurements). Bland-Altman plots also were used to assess multicenter creatinine and TCO2 results. Of the other analytes, K+, glucose, and urea nitrogen had the highest r2-values. For the eight chemistry profile tests performed at the point of care (yi, nonlaboratory personnel results; xi, medical technologist results), the average value of r2 was 0.96 (SD 0.08) in the operating room and 0.96 (SD 0.06) in the emergency room, and mean paired differences (yi - xi) were not statistically or clinically significant. Precision was acceptable. CONCLUSIONS: The performance of the creatinine biosensor and the TCO2 method was acceptable for whole-blood samples. Comparisons of whole-blood results from the transportable analyzer and plasma results from the local reference instruments revealed analyte biases that may be attributed to differences between direct whole-blood analyses and indirect-diluted plasma measurements and other factors. Performance of nonlaboratory personnel and medical technologists was equivalent for point-of-care testing in critical care settings. The whole-blood analyzer should be useful when patient care demands immediate results.

Biosensing Techniques↗
PubMed2000

Genotype/phenotype relationships in HNF-4alpha/MODY1: haploinsufficiency is associated with reduced apolipoprotein (AII), apolipoprotein (CIII), lipoprotein(a), and triglyceride levels.

Hepatocyte nuclear factor (HNF)-4alpha is a transcription factor that plays an important role in regulation of gene expression in pancreatic beta-cells and in the liver. Heterozygous mutations in the HNF-4alpha gene are responsible for maturity-onset diabetes of the young 1 (MODY1), which is characterized by pancreatic beta-cell-deficient insulin secretion. HNF-4alpha is a major transcriptional regulator of many genes expressed in the liver. However, no liver defect has been identified in individuals with HNF-4alpha mutations. In this study, we have identified HNF-4alpha target genes that are mainly expressed in the liver, including alpha1-antitrypsin, alpha1-antichymotrypsin, alpha-fetal protein, ceruloplasmin, IGF binding protein 1, transferrin, apolipoprotein(AI) [apo(AI)], apo(AII), apo(B), and apo(CIII). Serum levels of these proteins and Lp(a) and triglycerides were measured in 24 members of the HNF-4alpha/MODY1 RW pedigree (Q268X mutation), including 12 diabetic patients with HNF-4alpha mutations (D-HNF4+/-), 6 nondiabetic subjects with HNF-4alpha mutations (N-HNF4+/-), 6 normal relatives (N-HNF4+/+), 6 unrelated normal matched control subjects (N-HNF4+/+), and 12 matched diabetic (non-MODY1-5) patients (D-HNF4+/+). Serum levels of apo(AII), apo(CIII), lipoprotein(a) [Lp(a)], and triglyceride were significantly reduced in HNF4+/- subjects (26.9, 19.8, 12.1, and 72.1 mg/dl, respectively) compared with HNF4+/+ subjects (37.4, 26.5, 45.2, and 124.2 mg/dl, respectively) (P = 0.00001, P = 0.01, P = 0.00006, and P = 0.000003, respectively). This reduction was not found when apo(AII), apo(CIII), Lp(a), and triglyceride levels were compared in D-HNF4+/- versus N-HNF4+/- or in D-HNF4+/+ versus N-HNF4+/+ subjects, which indicates that HNF-4alpha haploinsufficiency rather than hyperglycemia is the primary cause of decreased serum protein and triglyceride concentrations. Furthermore, we determined that genetic or environmental modifiers other than HNF-4alpha do not appear to contribute to the observed decrease of HNF-4alpha-regulated serum proteins. This study demonstrates that a heterozygous HNF-4alpha mutation leads to an HNF-4alpha-dependent hepatocyte secretory defect of liver-specific proteins.

Adult↗
PubMed1998

Differential diagnosis of gammopathies by capillary electrophoresis and immunosubtraction: analysis of serum samples problematic by agarose gel electrophoresis.

The capabilities of capillary electrophoresis (CE) for serum protein electrophoresis and immunotyping have been demonstrated. CE-based systems specifically designed for serum protein electrophoresis and immunotyping via immunosubtraction (IS) are now available and are being evaluated for efficiency, specificity and sensitivity by several groups. The use of CE for serum protein electrophoresis and immunotyping (IS) in the clinical laboratory compares well with agarose gel electrophoresis (AGE) and immunofixation (IF) for the detection and characterization of monoclonal proteins. In addition to routine use, this technology is useful for a subset of serum samples that are difficult to interpret with conventional technology. In this study, sera abnormalities difficult to detect/interpret by AGE-IF are subdivided into four categories: (i) patients with polyclonal increases in immunoglobulin, (ii) point of application artifacts, (iii) abnormalities in the beta region, and (iv) patients with free light chains. CE is superior to AGE for evaluating samples characterized by the above abnormalities. Sera containing monoclonal proteins within a polyclonal increase are easier to detect by CE as well as being easier to type by IS than by IF. Point-of-application artifacts, periodically observed with AGE, do not exist on CE since the point of detection is remote from the point of application. Enhanced resolution in the beta region allows for increased detection of monoclonal proteins migrating in this region. Some free light chains are undetected by CE as a result of no apparent abnormalities on the CE serum protein profile and, thus, still require IF for detection. CE detects more serum electrophoretic abnormalities than AGE in this clinically important group of patients with Bence Jones proteinemia.

Antibodies, Monoclonal↗
PubMed1998

Persistent alterations of the autonomic nervous system after noncardiac surgery.

UNLABELLED: BACKGROUND. Changes in the sympathetic nervous system may be a cause of postoperative cardiovascular complications. The authors hypothesized that changes in both beta-adrenergic receptor (betaAR) function (as assessed in lymphocytes) and in sympathetic activity (assessed by plasma catecholamines and by heart rate variability [HRV] measurements obtained from Holter recordings) occur after operation. METHODS: The HRV parameters were measured in 28 patients having thoracotomy (n = 14) or laparotomy (n = 14) before and for as long as 6 days after operation. Transthoracic echocardiography was performed before and on postoperative day 2. Lymphocytes were also isolated from blood obtained before anesthesia and again on postoperative days 1, 2, 3, and 5 (or 6). They were used to examine betaAR number (Bmax) and cyclic adenosine monophosphate (cAMP) production after stimulation with isoproterenol and prostaglandin E1. In addition, plasma epinephrine, norepinephrine, and cortisol concentrations were determined at similar intervals. RESULTS: After abdominal and thoracic surgery, most time and all frequency indices of HRV decreased significantly, as did Bmax and basal and isoproterenol-stimulated cAMP production. The decrements in HRV correlated with those of Bmax and isoproterenol-stimulated cAMP throughout the first postoperative week and inversely correlated with the increase in heart rate. Plasma catecholamine concentrations did not change significantly from baseline values, but plasma cortisol levels did increase after operation in both groups. Left ventricular ejection fraction was normal in both groups and unaffected by surgery. CONCLUSIONS: Persistent downregulation and desensitization of the lymphocyte betaAR/adenylyl cyclase system correlated with decrements in time and frequency domain indices of HRV throughout the first week after major abdominal or thoracic surgery. These physiologic alterations suggest the continued presence of adaptive autonomic regulatory mechanisms and may explain why the at-risk period after major surgery appears to be about 1 week or more.

Aged↗
PubMed1997

Tumor cell reactivity mediated by IgM antibodies in sera from melanoma patients vaccinated with GM2 ganglioside covalently linked to KLH is increased by IgG antibodies.

Natural IgM antibodies against the melanoma cell-surface ganglioside GM2, and IgM antibodies induced by vaccination with GM2 adherent to bacillus Calmette-Guerin, have been correlated with increased disease-free and overall survival in melanoma patients in previous phase I and II clinical trials. A vaccine containing GM2 covalently attached to keyhole limpet hemocyanin (KLH) plus the immunological adjuvant QS-21 now induces higher-titer, longer-lasting IgM antibodies against GM2 and has recently entered phase III clinical trials. For the first time this new vaccine also induces IgG antibodies against GM2 in the majority of immunized patients. With regard to immunity against bacteria, IgM antibodies have been described to be 1000-fold more effective than IgG antibodies at opsonification, complement-mediated cytotoxicity and protection from bacterial challenge. Though IgG antibodies have the theoretical advantage of being able to mediate antibody-directed cell-mediated cytotoxicity (ADCC), they may inhibit complement mediated IgM effector mechanisms against melanoma cells. Our goal was to confirm the functional characteristics of the anti-GM2 IgM and IgG antibodies induced by vaccination and to determine the impact that IgG antibodies might have on IgM antibody reactivity with GM2-positive tumor cells. Post-immunization sera from seven immunized patients were separated by size-exclusion chromatography into IgM and IgG fractions and a variety of serological assays were performed with the individual fractions and their combinations. Assays identifying specific IgM or IgG reactivity demonstrated partial inhibition by the opposite fraction. However, when the endpoint was complement-mediated lysis or overall antibody binding, which may more faithfully predict in vivo complement-mediated opsonification and lysis, the combinations of IgM and IgG fractions consistently demonstrated higher reactivity than either fraction alone. In addition, ADCC was induced in all seven patients. The results were the same whether the sera were obtained after 2 months or 2 years of immunizations. These findings suggest that IgG antibodies induced by the GM2-KLH plus QS-21 vaccine will not inhibit and should further augment the clinical impact of induced IgM antibodies.

Antibodies, Neoplasm↗
PubMed1996

Carboxypeptidase G2 rescue after high-dose methotrexate.

PURPOSE: This study was a pilot project to assess the safety and efficacy of carboxypeptidase G2 (CPG2) rescue from high-dose (HD) methotrexate (MTX) in patients with recurrent cerebral lymphoma. PATIENTS AND METHODS: Four patients with recurrent primary CNS lymphoma (PCNSL) were studied. Patients received 3.0 g/m2 MTX infused over 2 hours. Twelve hours after the start of MTX, 50 U/kg CPG2 was infused; a second dose of CPG2 was given 6 hours after the first. Blood and CSF were collected and assayed for levels of MTX, CPG2, and 2,4-diamino-N10-methylpteroic acid (DAMPA), a cleavage product of MTX after CPG2. Serum was collected for at least 2 weeks after administration of MTX-CPG2 to assess anti-CPG2 activity antibodies. RESULTS: All patients had at least a 2-log decline in plasma MTX levels to the subtherapeutic range within 5 minutes of CPG2 administration. The second dose of CPG2 did not further diminish the already low plasma MTX level. DAMPA appeared and was detected as the plasma MTX concentration decreased. CSF MTX concentration remained elevated for 4 hours after CPG2, and its decline followed first-order kinetics. Anti-CPG2 activity antibodies were not detected in any patient. No MTX or CPG2 toxicity was observed. CONCLUSION: CPG2 rescue is a safe, effective alternative to leucovorin rescue after HD MTX and may prove particularly useful for the treatment of MTX-sensitive CNS tumors, as it does not affect CSF MTX levels.

Antimetabolites, Antineoplastic↗
PubMed1996

Crohn's disease and acute leukocytoclastic vasculitis of skin.

A 39-yr-old white male with a prolonged history of Crohn's disease presented with worsening diarrhea associated with an increasingly painful rash of both lower extremities as well as left ankle swelling. A skin biopsy revealed an acute leukocytoclastic vasculitis. Intravenous hydrocortisone followed by oral prednisone achieved a rapid remission of the both cutaneous and gastrointestinal manifestations. Long-term remission has been maintained with 6-mercaptopurine and mesalamine. The rare association between cutaneous vasculitis and Crohn's disease is discussed and earlier reported cases reviewed.

Adult↗
PubMed1996

High-dose edatrexate with oral leucovorin rescue: a phase I and clinical pharmacological study in adults with advanced cancer.

Our objective was to determine the maximum tolerated dose and toxicity of i.v. edatrexate with p.o. leucovorin. Thirty-one adults with advanced solid tumors received edatrexate as a 2-h infusion, once a week for 3 weeks, recycled every 28 days. p.o. leucovorin (10 mg/m2, every 6 h for 10 doses) began 24 h later. All had urinary alkalinization and p.o. hydration. Nine dosage levels ranging from 120 to 3750 mg/m2 were explored. Fatigue, epistaxis, nausea/emesis, mucositis, rash, myalgias, leukopenia, thrombocytopenia, and transient elevations of serum aspartate transferase were observed. Leukoencephalopathy with clinical manifestations occurred in two patients (one had prior cranial irradiation). Pharmacokinetic studies carried out at the 120- and 1080-mg/m2 dose levels revealed no significant difference in the elimination half-life at the two dose levels studied and no significant intrapatient variability between day 1 and day 8 edatrexate administration. Serum edatrexate levels measured using a dihydrofolate reductase inhibition assay correlated with those by high-performance liquid chromatography. Three major and two minor antitumor responses occurred. The maximum tolerated dose was 3750 mg/m2, with grade 3 or 4 leukopenia (one patient), stomatitis (one patient), and leukoencephalopathy (one patient). Because of the occurrence of leukoencephalopathy, further study of high-dose edatrexate with leucovorin rescue is not recommended.

Administration, Oral↗
PubMed1995

Automated approaches to rapid-response testing. A comparative evaluation of point-of-care and centralized laboratory testing.

This study evaluates the premise that point-of-care or near-patient testing provides more effective medical care because laboratory turnaround time is reduced and, therefore, presumably the time before therapy begins is reduced. An accurate evaluation of this premise must compare the operation of a point-of-care laboratory and an alternative dedicated, centralized laboratory. Assessment of both laboratory operations with respect to turnaround time, costs and benefits, regulatory factors, and finally patient care outcome are all essential in reaching a conclusion. In this study, laboratory operations in a centralized urgent care laboratory were compared with those of a point-of-care satellite laboratory. Turn-around time analysis for whole blood (heparinized specimens requiring no centrifugation) and serum analytes were measured during a representative time period. Analysis of turnaround time considered both the preanalytic time, defined as collection to receipt of the specimen in the laboratory, and the analytic time component that accounts for receipt, processing, analysis, and reporting of the final data into the laboratory information system. The preanalytic component of the point-of-care satellite laboratory was also compared with the urgent care laboratory equipped with a rapid-transport specimen system. Turnaround time in the point-of-care satellite laboratory and urgent care laboratory equipped with a rapid-transport specimen system. Turnaround time in the point-of-care satellite laboratory and urgent care laboratory equipped with a rapid-transport system were comparable. In this analysis, staff requirements, ability to comply with regulatory requirement, and the increasing demand for a larger selection of tests needed urgently were considered. In a tertiary care medical center, such as the authors', a dedicated, centralized laboratory equipped with a rapid-transport specimen system provides better comprehensive laboratory service than does a point-of-care facility with limited capability.

Automation↗