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R Frey

Publications and source records attributed to R Frey.

At least 37 records · Page 2Linked to original sources
PubMed2001

Measurements of F2 and xF(nu)(3) - xF(nu;)(3) from CCFR nu(mu)-Fe and nu;(mu)-Fe Data in a Physics Model-Independent Way.

We report on the extraction of the structure functions F2 and DeltaxF(3) = xF(nu)(3)-xF(nu;)(3) from CCFR nu(mu)-Fe and nu;(mu)-Fe differential cross sections. The extraction is performed in a physics model-independent (PMI) way. This first measurement of DeltaxF(3), which is useful in testing models of heavy charm production, is higher than current theoretical predictions. The ratio of the F2 (PMI) values measured in nu(mu) and mu scattering is in agreement (within 5%) with the predictions of next-to-leading-order parton distribution functions using massive charm production schemes, thus resolving the long-standing discrepancy between the two sets of data.

Journal Article↗
PubMed2001

Improved direct measurement of leptonic coupling asymmetries with polarized Z bosons.

We present final measurements of the Z boson-lepton coupling asymmetry parameters A(e), A(mu), and A(tau) with the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. From the left-right production and decay polar angle asymmetries in leptonic Z decays we measure A(e) = 0.1544+/-0.0060, A(mu) = 0.142+/-0.015, and A(tau) = 0.136+/-0.015. Combined with our left-right asymmetry measured from hadronic decays, we find A(e) = 0.1516+/-0.0021. Assuming lepton universality, we obtain a combined effective weak mixing angle of sin (2)theta(eff)(W) = 0.230 98+/-0.000 26.

Journal Article↗
PubMed2001

First symmetry tests in polarized Z0 decays to bbg.

We have made the first direct symmetry tests in the decays of polarized Z0 bosons into fully identified bbg states, collected in the SLD experiment at SLAC. We searched for evidence of parity violation at the bbg vertex by studying the asymmetries in the b-quark polar- and azimuthal-angle distributions, and for evidence of T-odd, CP-even or CP-odd, final-state interactions by measuring angular correlations between the three-jet plane and the Z0 polarization. We found results consistent with standard model expectations and set 95% C. limits on anomalous contributions.

Journal Article↗
PubMed2001

[Use of electroconvulsive therapy in psychiatry].

Electroconvulsive therapy (ECT) has antidepressive and antipsychotic effects. Since being introduced in Italy in 1938, its mode of action has still not been clarified. Treatment modalities have changed in many ways. ECT, in which a generalized epileptic seizure is provoked by electrical stimulation of the brain, is performed under short intravenous anesthesia and muscle relaxation. Considering careful previous clinical examination and anesthesiological and internal counterindications, ECT is a very safe form of treatment. Single cases of persisting memory impairment were described after the formerly common bilateral sinus wave stimulation. However, recent developments such as brief pulse stimulation, unilateral electrode placement, and individual stimulus titration (on the basis of EEG monitoring) make memory impairment as a consequence of ECT a rare event which mostly remits completely in 4-8 weeks. Today, ECT is performed mainly in patients suffering from severe, therapy-resistant affective or schizophrenic disorders. Pernicious catatonia and the neuroleptic malignant syndrome are emergency indications. Adequate ECT treatment requires a series of 6-12 individual sessions (every second or third day). In therapy-resistant depression, for which the greatest number of data are available, the response rate lies between 50 and 60%. This has been confirmed by a descriptive analysis of all ECT treatments at the Department of Psychiatry, University of Vienna, between 1994 and 2000. There is a need for controlled studies on continuation therapy subsequent to successful ECT.

Antipsychotic Agents↗
PubMed2001

Different fatal toxicity of neuroleptics identified by autopsy.

Autopsies and toxicological analyses at the Institute of Forensic Medicine revealed 85 fatal intoxications with neuroleptics in Vienna from 1991 to 1997. A total of 17 cases were linked to a single neuroleptic (NL) alone, while 68 deaths were attributed to a combination of NLs with other drugs. The most frequently detected agent was prothipendyl (n=41). During the study period the number of defined daily doses of high-potency NLs prescribed increased significantly (P< or =0.001) due to increased prescribing of new atypical antipsychotics. The quantity of intermediate- and low-potency NLs dispensed remained stable. The most frequently prescribed NL was haloperidol. The relative toxicities of different NLs were calculated by dividing the number of deaths caused by this NL into the number of defined daily doses prescribed in the observation period (f-value). Single-substance intoxications and multiple-substance intoxications were distinguished. The highest f-values were associated with low-potency NLs, especially with prothipendyl, chlorprothixene and levomepromazine. Low f-values were found for the group of high-potency NLs, including flupentixol, fluphenazine, haloperidol and pimozide, as well as olanzapine. Compared to the f-values for all NLs prescribed, f-values for low-potency NLs were shown to be significantly higher concerning single-substance intoxications (P< or = 0.05) and multiple-substance intoxications (P < or = 0.001), while f-values for high-potency NLs were significantly lower (P< or = 0.05 and P< or = 0.001). We are not aware of the psychiatric diagnoses in our post-mortem sample. However, the present results indicate that careless use of low-potent NLs should be avoided in patients with a potential risk of accidental or suicidal overdose.

Adult↗
PubMed2001

Inverse relation between stimulus intensity and seizure duration: implications for ECT procedure.

A retrospective analysis of the effects of electroconvulsive therapy (ECT) was performed for two groups of 11 patients matched according to age (mean age, 52 years), sex, and diagnosis. Group 1 received ECT according to the age-dose protocol; group 2 was treated according to the titration method. A higher dose relative to the seizure threshold appeared to shorten the seizure duration. At the first treatment, the correlation between stimulus intensity and seizure duration was negative. In the titration group, the initial mean charge of 91 mC resulted in a seizure duration of 51 s, whereas in the age-dose group the seizure duration of 31 s was significantly shorter despite a higher mean charge of 312 mC. Seizure duration decreased during the ECT course in the group treated first at low dose (titrated) and then at 2.5 times the initial threshold. High stimulus intensity represented adequate treatment, although it produced short seizures. Thus, seizure duration proved to be an unreliable guideline for effective treatment. Furthermore, focus on seizure duration led to frequent high-dose restimulation in the elderly. The titration method obviates inadequate or excessive charges because the seizure threshold must first be determined.

Adult↗
PubMed2000

High-precision measurement of the left-right Z Boson cross-section asymmetry.

We present a measurement of the left-right cross-section asymmetry ( A(LR)) for Z boson production by e(+)e(-) collisions. The measurement includes the final data taken with the SLD detector at the SLAC Linear Collider during the period 1996-1998. Using a sample of 383 487 Z decays collected during the 1996-1998 runs we measure the pole value of the asymmetry, A(0)(LR), to be 0.150 56+/-0.002 39 which is equivalent to an effective weak mixing angle of sin (2)straight theta(eff)(W) = 0.231 07+/-0.000 30. Our result for the complete 1992-1998 data set comprising approximately 537 000 Z decays is sin (2)straight theta(eff)(W) = 0.230 97+/-0.000 27.

Journal Article↗
PubMed2000

[Acute myocardial infarction: time delay from onset of pain to hospital presentation and thrombolysis].

BACKGROUND: The efficacy of thrombolytic therapy in patients with myocardial infarction depends largely on the delay to initiation of treatment. METHODS: From February 1996 to May 1997 we prospectively studied 175 patients hospitalised for acute chest pain and suspected coronary heart disease. We determined the delays between onset of pain and calling for medical help, hospital arrival and thrombolysis. RESULTS: The median delay until hospital presentation was 3.1 hours, with no difference between male and female or younger and older patients. 35% of the patients arrived at the hospital within 2 hours, 38% within 2-6 hours and 27% after more than 6 hours. Most of the delay was caused by the patients (median 2.0 hours). Emergency doctors contributed 35 minutes, and transport to the hospital took 31 minutes. 99 patients (57%) were diagnosed with acute myocardial infarction. 53 (54%) fulfilled the criteria for thrombolysis and were so treated. The median overall delay from onset of pain to thrombolysis was 2.9 hours. 77% received treatment within 6 hours, and 23% within 6-12 hours after onset of pain. The median delay inside the hospital (door to needle) was 40 minutes. CONCLUSIONS: 75% of patients with acute chest pain arrived at the hospital within 6 hours of onset of symptoms. Most of the delay was caused by the patients themselves, a factor which needs to be improved by better education. Moreover, optimising in-hospital processes should further shorten the delay to thrombolysis.

Adult↗
PubMed2000

Search for a 33.9 MeV/c(2) neutral particle in pion decay

The E815 (NuTeV) neutrino experiment has performed a search for a 33. 9 MeV/c(2) weakly interacting neutral particle produced in pion decay. Such a particle may be responsible for an anomaly in the timing distribution of neutrino interactions in the KARMEN experiment. E815 has searched for this particle's decays in an instrumented decay region; no evidence for this particle was found. The search is sensitive to pion branching ratios as low as 10(-13).

Journal Article↗
PubMed2000

Suicide by antidepressant intoxication identified at autopsy in Vienna from 1991-1997: the favourable consequences of the increasing use of SSRIs.

In the area of Vienna, any person dying under questionable circumstances is examined at the Institute of Forensic Medicine, where the cause of death is determined by means of autopsy and chemical analysis. Our study on fatal intoxications was performed in the period between 1991 and 1997, when selective serotonin reuptake inhibitors (SSRIs) were establishing themselves on the market, reaching the top of prescription statistics. Tricyclic antidepressants (TCAs) were involved in 30 single- and 127 multiple-substance intoxications, with amitriptyline and doxepin being the most frequently used drugs. SSRIs were involved in five multiple-substance intoxications. The f-value, which refers to the number of deaths per million defined daily doses prescribed, was found to be significantly (P</=0.001) higher in TCAs than in SSRIs. The f-value for the total group of all antidepressants declined significantly (P</=0.05) during the observation period of 7 years. In conclusion, SSRIs turned out to be less toxic than TCAs, and the increasing use of new antidepressants did not coincide with an increased number of deaths caused by these drugs.

Antidepressive Agents↗
PubMed2000

Pharmacokinetics of cerivastatin when administered under fasted and fed conditions in the morning or evening.

OBJECTIVE: The influence of food and time of drug dosing on the pharmacokinetics of cerivastatin, a potent HMG-CoA reductase inhibitor, was evaluated in 24 healthy male subjects between 21 and 44 years of age. METHODS: A single-dose, four-way crossover design was employed, with each subject receiving cerivastatin 0.8 mg at weekly intervals under each of four conditions: 8 a.m. dosing after an overnight fast (reference), 8 a.m. dosing with a high-fat breakfast (test), 6 p.m. dosing with the evening meal (low-fat; test), and 10 p.m. dosing 4 h after dinner (reference). Plasma concentrations of the parent compound and its active metabolites were measured by high performance liquid chromatography with fluorescence detection subsequent to post-column derivatization. RESULTS: The calculated 90% confidence intervals for cerivastatin AUC and Cmax were completely contained within the range 0.8 to 1.25. Thus, no relevant influence of food could be detected, although the presence of food increased the Cmax of cerivastatin on average by 12% (90% confidence interval: 1.04 - 1.21) under morning, but not evening dosing. With respect to the effect of daytime on cerivastatin pharmacokinetics, AUCs were bioequivalent for all treatment conditions, with Cmax values slightly lower (8 - 19%) following evening dosing, irrespective of food intake. Cerivastatin was well tolerated by the subjects in the study. CONCLUSION: Food effect bioequivalence according to current guidelines could be demonstrated. Cerivastatin can be administered independent of meal intake at dinner or at bedtime, the preferred time of dosing for statins because the rate of hepatic cholesterol synthesis is greatest at night.

Adult↗
PubMed1999

Treatment of severe mania with intravenous magnesium sulphate as a supplementary therapy.

Ten patients with severe, therapy-resistant manic agitation received magnesium sulphate infusions with a continuous magnesium (Mg) flow of approximately 200 mg/h (4353+/-836 mg/day; daily monitored Mg plasma level: 2.44+/-0.34 mmol/l) for periods ranging from 7 to 23 days. Concomitant psychotropic treatment consisted of lithium (n = 10), haloperidol (n = 5) and clonazepam (n = 10). During i.v. Mg treatment the mean values of the maximum dosages of neuroleptics (in chlorpromazine equivalents) and benzodiazepines (in diazepam equivalents) were significantly lower than during the last day of pretreatment (= baseline). Seven patients showed a marked improvement in the Clinical Global Impression scale. In case of bradycardia detected by the ECG monitor (n = 5), Mg flow was reduced and bradycardia disappeared promptly. Mg i.v. may be a useful supplementary therapy for the clinical management of severe manic agitation. This open study needs double-blind confirmation.

Adult↗
PubMed1999

Trends in AIDS among Hispanics in the United States, 1991-1996.

OBJECTIVES: This article describes recent trends in AIDS among US Hispanics. METHODS: Incidence rates were calculated from AIDS surveillance data for persons diagnosed from 1991 through 1996. Increases in the number of cases among Hispanics were calculated by linear regression. RESULTS: Of the 415,864 persons diagnosed with AIDS from 1991 through 1996, 19% were Hispanic. Among Hispanics with AIDS, 67% were born in the United States or Puerto Rico. The relative risk (RR) of AIDS for Hispanics compared with Whites was highest for women (RR = 7.0), followed by children (RR = 6.2) and men (RR = 2.8). Increases in the number of cases were higher among foreign-born Hispanics. CONCLUSIONS: An understanding of which Hispanic subgroups are at greatest risk for HIV infection is important for prevention efforts.

Acquired Immunodeficiency Syndrome↗
PubMed1999

[Clinical value of electroconvulsive therapy in treatment of depression].

The electroconvulsive therapy (ECT), which provokes a generalized epileptic seizure by an electrical stimulus, was first administered in 1938 and performed without anesthesia during thirty years. Nowadays, ECT is carried out using brief anesthesia (preferably methohexital) and skeletal muscle relaxation (succinylcholine) to avoid fearful complications like bone and muscle fractures. ECT is a safe treatment without absolute contraindications; the treatment risk corresponds to the risk of general anesthesia. ECT is indicated in depression, mania and schizophrenia. It plays an important role in the treatment of therapy resistant, severely ill patients with affective disorders, suicidal drive, delusional symptoms, vegetative dysregulation, inanition and catatonic symptoms. The response rate (remission or marked improvement) is about 70%. Usually ECT is performed 3 times per week, resulting in an ECT course with a total number of 6 to 12 single treatments. Within 2 or 3 weeks a substantial improvement can be expected. Further controlled studies are required with regard to antidepressive and/or antipsychotic continuation therapy after successful ECT course. Brief pulse stimulation, unilateral nondominant electrode placement and individual stimulus titration with respect to seizure threshold (EEG monitoring is required!) can minimize cognitive side effects. The apprehension that ECT could cause prolonged amnesia and structural brain damage has not been confirmed by the available scientific data. Modern brain imaging methods could elicit the until now unknown mode of action of ECT.

Bipolar Disorder↗
PubMed1998

Monitoring of proteinuria in phase I studies in healthy male subjects.

OBJECTIVE: The quantitative measurement of urinary marker proteins may improve the sensitivity of monitoring renal function in healthy male subjects in phase I studies. Little is known about the variability of physiological proteinuria in young, healthy male subjects. Thus, the biological and analytical variability of three marker proteins, i.e. albumin, alpha(1)-microglobulin and N-acetyl-beta-D-glucosaminidase (NAG), were investigated in this population. METHODS: Seven young, healthy male subjects participated in a prospective two-way cross-over study, and 139 in a retrospective study. Albumin and alpha(1)-microglobulin were determined by immunological methods (radial immunodiffusion and/or kinetic nephelometry), and NAG by enzyme activity in a colorimetric assay. RESULTS: The inter-assay precision of NAG, albumin and alpha(1)-microglobulin is good (< 15%) if automated kinetic nephelometry is applied for albumin and alpha(1)-microglobulin determination, but less impressive (< 25%) with radial immunodiffusion. The highest frequency of detectable proteinuria and highest creatinine-adjusted protein levels are found in the second morning urine voided after a night's rest. The intra-individual biological variability of NAG excretion from day to day is low (CV: 15-25%), irrespective of outpatient or inpatient settings. By contrast, albumin and alpha(1)-microglobulin excretion can differ by a factor of 2-3 from day to day, and higher levels are predominantly found in outpatient settings. The reference ranges for young, healthy male subjects are generally lower than published in cross-sectional studies in the total healthy population. CONCLUSION: These findings and established reference ranges for young, healthy male subjects may assist in the evaluation of proteinuria in clinical pharmacological phase I trials.

Acetylglucosaminidase↗
PubMed1998

Trends in HIV seropositivity in publicly funded HIV counseling and testing programs: implications for prevention policy.

INTRODUCTION: We describe trends in seropositivity among clients attending publicly funded HIV counseling and testing sites across the United States and discuss implications for prevention policy. METHODS: The present analysis used client-level data from 1990 through 1994 for 26 of 65 state, territorial, and local health departments receiving Centers for Disease Control and Prevention funds. Logistic regression was used to predict the proportion of HIV tests that were positive. Curves were created representing adjusted HIV seropositivity trends for 1990 through 1994. RESULTS: HIV seropositivity rates were higher before 1992. Throughout, rates were higher among men, most racial/ethnic minorities tested, and persons 30 years or older. Although rates for men remained higher than those for women, the gap has narrowed in recent years. For both men and women, rates remained low for those reporting heterosexual activity as their only potential risk for HIV. Over time, more high-risk seronegatives are being repeatedly tested. CONCLUSIONS: Lower, stabilized seropositivity rates after 1992 reflect large increases in testing volume, increasing frequency of repeat testing, and fewer asymptomatic-infected persons entering this public system. Various program innovations including enhanced outreach, improved access, rapid testing, and client-centered counseling should be considered as strategies to increase the number of infected persons who learn their serostatus early and enter into medical care.

Adolescent↗