PubMed Health⌕ Search

Biomedical subjects

R Edelstein

Publications and source records attributed to R Edelstein.

At least 19 recordsLinked to original sources
PubMed2004

Observation of a narrow charm-strange meson D(+)(sJ)(2632)-->D(+)(s)eta and D(0)K(+).

We report the first observation of a charm-strange meson D(+)(sJ)(2632) at a mass of 2632.5+/-1.7 MeV/c(2) in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, D(+)(s)eta and D0K+. In the D(+)(s)eta decay mode we observe a peak with 101 events over a combinatoric background of 54.9 events at a mass of 2635.4+/-3.3 MeV/c(2). There is a corresponding peak of 21 events over a background of 6.9 at 2631.5+/-2.0 MeV/c(2) in the decay mode D0K+. The decay width of this state is <17 MeV/c(2) at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(D(+)(s)eta) is 0.14+/-0.06. The mechanism that keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the D(+)(s)eta decay mode.

Journal Article↗
PubMed2002

First observation of the doubly charmed baryon Xi(+)(cc).

We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1+/-0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is 3519+/-1 MeV/c(2). The Gaussian mass width of this state is 3 MeV/c(2), consistent with resolution; its lifetime is less than 33 fs at 90% confidence.

Journal Article↗
PubMed2001

Precision measurements of the lambda(+)(c) and D0 lifetimes.

We report new precision measurements of the lifetimes of the Lambda(+)(c) and D0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 Lambda(+)(c) and 10 210 D0 decays we observe lifetimes of tau[Lambda(+)(c)] = 198.1+/-7.0+/-5.6 fs and tau[D0] = 407.9+/-6.0+/-4.3 fs.

Journal Article↗
PubMed2001

Predicting outcomes of trials of labor in women attempting vaginal birth after cesarean delivery: a comparison of multivariate methods with neural networks.

OBJECTIVE: Our aim was to assess the utility and effectiveness of a neural network for predicting the likelihood of success of a trial of labor, relative to standard multivariate predictive models. STUDY DESIGN: We identified 100 failed trials of labor and 300 successful trials of labor in women with a prior cesarean delivery performed at our institution. Information was collected on >70 potential predictors of labor outcomes from the medical records, including demographic, historical, and past obstetric information, as well as information from the index pregnancy. Bivariate analyses comparing women in whom a trial of labor failed with those whose trial succeeded were performed. These initial analyses were used to select variables for inclusion into our muitivariate predictive model. From the same data we trained and tested a neural network, using a back-propagation algorithm. The test characteristics of the multivariate predictive model and the neural network were compared. RESULTS: From the bivariate analysis a history of substance abuse (adjusted odds ratio, 0.27; 95% confidence interval, 0.09-0.80), a successful prior vaginal birth after cesarean delivery (adjusted odds ratio, 0.13; 95% confidence interval, 0.05-0.31), cervical dilatation at admission (adjusted odds ratio, 0.53; 95% confidence interval, 0.31-0.88), and the need for labor augmentation (adjusted odds ratio, 2.15; 95% confidence interval, 1.14-4.06) were ultimately discovered to be important in predicting the likelihood of the success or failure of a trial of labor. With these variables in the predictive model the sensitivity of the derived rule for predicting failure was 77%, the specificity was 65%, and the overall accuracy was 69%. We also built a network using the 4 variables that were included in the final multivariate model. We were unable to achieve the same degree of sensitivity and specificity that we observed with the regression-based predictive model (sensitivity and specificity, 59% and 44%). CONCLUSION: In this study a standard multivariate model was better able to predict outcome in women ttempting a trial of labor.

Adult↗
PubMed1997

Antibody immobilization using heterobifunctional crosslinkers.

Covalent attachment of functional proteins to a solid support is important for biosensors. One method employs thiol-terminal silanes and heterobifunctional crosslinkers such as N-succinimidyl 4-maleimidobutyrate (GMBS) to immobilize proteins through amino groups onto glass, silica, silicon or platinum surfaces. In this report, several heterobifunctional crosslinkers are compared to GMBS for their ability to immobilize active antibodies onto glass cover slips at a high density. Antibodies were immobilized at densities of 74-220 ng/cm2 with high levels of specific antigen binding. Carbohydrate-reactive crosslinkers were also compared to GMBS using a fiber optic biosensor to detect fluorescently-labeled antigen. At the concentrations tested, the antibodies immobilized with carbohydrate-reactive crosslinkers bound more antigen than GMBS immobilized antibodies as indicated by the fluorescence signal.

Biosensing Techniques↗
PubMed1986

The effect of RU 41.740, an immune modulating compound, in the prevention of acute exacerbations in patients with chronic bronchitis.

The effect of Biostim (RU 41.740), a new non-specific immune modulator, in reducing the number of acute exacerbations in patients with chronic bronchitis, was examined. One hundred and ninety-eight patients with chronic bronchitis stages 2 and 3 entered the study, which was conducted as a multicenter, double-blind, parallel three-group, placebo-controlled trial. The patients were randomised to placebo, Biostim 2 or 8 mg per day, and received treatment for 1 week every other week for 3 successive months during the winter 1983. A significant (p = 0.005) reduction in the number of acute exacerbations was observed in the patients treated with Biostim 2 mg/day, whereas no effect was observed in the placebo or 8 mg/day group. No serious side-effects were encountered.

Acute Disease↗
PubMed1982

Immunosuppressive effect of acute-phase reactant proteins in vitro and its relevance to cancer.

Acute-phase reactant proteins reach abnormally high levels in patients with cancer, and correlate with the extent of disease. In this study, several acute-phase glycoproteins, and serum albumin as a control, were tested at different concentrations for their ability to modify the blastogenic response of lymphocytes from 30 normal donors to PHA and the chemotactic response of monocytes from 15 normal donors to casein. In high concentrations approximating those found in cancer patients, but not in normal concentrations, haptoglobin and fibrinogen inhibited both functions to different degrees. Orosomucoid inhibited only monocyte chemotaxis, while ceruloplasmin and alpha 1-antitrypsin affected neither function. Increasing concentrations of PHA did not overcome the blocking effect of haptoglobin and fibrinogen on blastogenesis, suggesting that PHA-protein interaction was not responsible for the effect observed. The three proteins that did not suppress blastogenesis individually did so strongly when combined. It is suggested that these glycoproteins, synthesized by the liver in response to an inflammatory stimulus, may act as 'non-specific blocking factors' protecting tumors against the host's immunological attack. This non-specific blocking activity of the acute-phase proteins may contribute to the 'immune escape' of the tumor.

Ceruloplasmin↗
PubMed1982

In vivo nonspecific macrophage chemotaxis in cancer patients and its correlation with extent of disease, regional lymph node status, and disease-free survival.

We have used a test to evaluate macrophage migration in vivo, derived from the technique of Rebuck. The test is based on counting the absolute number of macrophages that migrate into an inflammatory site determined by a standardized superficial skin abrasion. It was applied to the study of macrophage migration in cancer patients in different clinical situations. Macrophage migration was virtually abolished in patients with metastatic cancer as compared to healthy controls. In patients with resectable breast and lung tumors, the test performed preoperatively correlated closely with lymph node status as determined by pathological examination after operation. Patients without lymph node involvement showed a significantly stronger response than did controls, whereas those with lymph node involvement had a diminished or even an abolished response. Distinctive subgroups were characterized among patients both with and without lymph node involvement on the basis of their macrophage response, and these subgroups proved to have distinctly different prognoses, particularly the patients without lymph node involvement with a poor macrophage response who had an unusually poor prognosis. It is concluded that this test shows potential for predicting the prognosis among categories of patients hitherto considered as homogeneous, although further evaluation in larger numbers of patients is necessary.

Adult↗
PubMed1981

Lymphoid cells infiltrating human pulmonary tumors: effect of intralesional BCG injection.

Tumor-infiltrating lymphocytes (TIL) and regional lymph node lymphocytes (LNL) were isolated by mechanical disaggregation and density gradient centrifugation from 30 untreated human lung tumors and 12 BCG-injected human lung tumors. Lymphocyte populations were characterized by their ability to form erythrocyte (E)-rosettes, erythrocyte-antibody-complement, and erythrocyte-antibody gamma-rosettes, by their proportion of esterase-staining cells, and by their responses in mixed lymphocyte culture (MLC), cell-mediated lympholysis (CML). and natural killer (NK) assays. TIL from untreated tumors had low proportions of E-rosetting cells (mean, 27.3%), relatively high proportions of "null" cells, and poor responses in MLC-CML and NK assays. There were no significant differences between primary lung tumors and lung metastases in rosettes, MLC-CML responses, or NK activity. In contrast, TIL from tumors injected with BCG 14 days before resection had higher proportions of E-rosetting cells (47.8%) and vigorous MLC-CML and NK responses. LNL from 11 patients with untreated tumors had higher proportions of E-rosetting cells (40.5%) than LNL from 9 patients with BCG-injected tumors (35.0%) and LNL from patients with untreated tumors had higher responses than LNL from treated patients in MLC-CML assays. These results suggest that the BCG injection induced an infiltration of functionally reactive NK and T-cells at the tumor site without an associated increased activity of T-cells from regional lymph nodes.

BCG Vaccine↗
PubMed1981

[Immunosuppressive effects of acute phase reactant proteins. Physiopathological role in cancer patients (author's transl)].

Several acute phase reactants have been shown by us and by others to reach abnormally high levels in cancer patients, the more so when the disease is disseminated. These glycoproteins have been tested in vitro for their ability to interfere with PHA blastogenesis and monocyte chemotactism of mononucleated cells from normal donors. It is shown that, used at the concentration they reach in cancer patients, haptoglobin fibrinogen, alpha 2-macroglobulin and transferrin inhibit both tests, whereas orosomucoid inhibits only the in vitro chemotactism of monocytes. It is proposed that these glycoproteins, synthesized by the liver in a response to inflammatory stimuli, are protecting the tumors against immune mechanisms of the host and are therefore part of the immune escape mechanism employed by the tumors.

Blood Proteins↗
PubMed1980

Testing the monocyte-macrophage system in human cancer.

The participation of the monocyte-macrophages cells in the host immune defence mechanisms against cancer has been recognized since a few years. Testing this component of host homeostasis appears as an additional tool necessary for evaluation of immune deficiency in cancer patient. We review here the most current tests used in the frame of such an evaluation, and also the most interesting results.

Chemotaxis, Leukocyte↗
PubMed1978

In vivo and in vitro studies on nonspecific blocking factors of host origin in cancer patients. Role of plasma exchange as an immunotherapeutic modality.

Experimental and clinical data are reviewed on elevated glycoprotein levels in tumor-bearing animals and patients at various stages of disease advancement. The authors report their findings in 232 patients with various solid tumors; these confirm and extend the reports in the literature. It is shown that some of these glycoproteins, rich in sialic acid, exhibit immunosuppressive properties in vitro, and it is suggested that tumors may protect themselves by triggering hepatic synthesis of sialoglycoproteins which "coat" the binding sites of both immunocompetent cells and tumor cells and thereby abrogate recognition and killing of the latter by the immune system. This concept of nonspecific blocking factors of host origin has already been substantiated to some extent by observations on the consequences of plasma exchange in 24 patients with metastatic tumors; eight of these patients exhibited an objective tumor regression. It is suggested that such studies should be extended to postoperative patients and that circulating sialoglycoprotein assays could be one of the ways of monitoring tumor growth, including growth during the nonvisible phase.

Animals↗
PubMed1978

Immunological and plasma protein changes in cancer patients following a single plasmapheresis.

Serial serum protein determinations and immunological monitoring were performed prior to and following a single 4 to 5 liter plasma exchange in 10 patients with disseminated cancer. The most consistent changes were observed for two initially elevated alpha globulins, acid glycoprotein and haptoglobin, which declined rapidly in all patients 1 hour after plasmapheresis and began to rise again as early as 24 hours post-plasmapheresis to reach initial levels by 72 hours. Among the immunological parameters T and B cell counts, and phytohemaglutinin-induced lymphocyte transformation showed little change. In 4 out of 10 patients C3 levels dropped at 1 hour post-plasmapheresis and continued to decline to 24 hours, suggesting that consumption of C3 possibly by macrophages may have occurred. In view of our earlier reports that repeated plasmapheresis induced partial tumor regressions in patients with disseminated cancer and that these regressions may have been related to depletion of immunosuppressive serum proteins, it is suggested that to maintain levels of these rapidly renewed proteins at a minimum for as long as possible, it is most appropriate to perform plasmapheresis every 48 hours rather than every 72 or 96 hours as was the case in the earlier study.

Adult↗