Treatment of severe, nonfulminant acute hepatitis B with lamivudine vs placebo: a prospective randomized double-blinded multicentre trial

Acute hepatitis B virus (aHBV) infection can lead to fulminant liver failure, which likely is prevented by early lamivudine therapy. Even nonfulminant but severe acute hepatitis B can lead to significant morbidity and impaired quality of life. Therefore, lamivudine was evaluated in patients with severe aHBV in a placebo-controlled trial. Patients with severe aHBV infection (ALT >10× ULN, bilirubin >85 μm, prothrombin time >50%) were prospectively treated with lamivudine 100 mg/day or with placebo within 8 days after the diagnosis. The primary end point was time to bilirubin <34.2 μm. Secondary end points were time to clear HBsAg and HBV-DNA, development of anti-HBs and normalization of ALT. Eighteen cases were randomized to lamivudine, 17 to placebo. 94% of patients were hospitalized. No individual progressed to hepatic failure; all but one patient achieved the primary end point. Due to smaller than expected patient numbers, all study end points did not become statistically significant between treatment arms. Median time end points [in days] were bilirubin <34.2 μm (26.5 vs 32), ALT normalization (35 vs 48) and HBsAg clearance (48 vs 67) referring to earlier recovery under lamivudine, in contrast to loss of HBV-DNA (62 vs 54) and development of anti-HBs (119 vs 109). In all but two patients (one in every group), HBsAg clearance was reached in the study. Adverse events occurred more frequently during lamivudine therapy, but did not reach statistical significance. Lamivudine may ameliorate severe aHBV infection, but limited patient numbers prevented definite conclusions.

3D numerical simulations of negative hydrogen ion extraction using realistic plasma parameters, geometry of the extraction aperture and full 3D magnetic field map

Decreasing the co-extracted electron current while simultaneously keeping negative ion (NI) current sufficiently high is a crucial issue on the development plasma source system for ITER Neutral Beam Injector. To support finding the best extraction conditions the 3D Particle-in-Cell Monte Carlo Collision electrostatic code ONIX (Orsay Negative Ion eXtraction) has been developed. Close collaboration with experiments and other numerical models allows performing realistic simulations with relevant input parameters: plasma properties, geometry of the extraction aperture, full 3D magnetic field map, etc. For the first time ONIX has been benchmarked with commercial positive ions tracing code KOBRA3D. A very good agreement in terms of the meniscus position and depth has been found. Simulation of NI extraction with different e/NI ratio in bulk plasma shows high relevance of the direct negative ion extraction from the surface produced NI in order to obtain extracted NI current as in the experimental results from BATMAN testbed.

First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE)

The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some results concerning the BATMAN beam under varying operating conditions.

Abnormal prefrontal activity subserving attentional control of emotion in remitted depressed patients during a working memory task with emotional distracters

BACKGROUND

Patients with major depressive disorder (MDD) show deficits in processing of facial emotions that persist beyond recovery and cessation of treatment. Abnormalities in neural areas supporting attentional control and emotion processing in remitted depressed (rMDD) patients suggests that there may be enduring, trait-like abnormalities in key neural circuits at the interface of cognition and emotion, but this issue has not been studied systematically.

METHOD

Nineteen euthymic, medication-free rMDD patients (mean age 33.6 years; mean duration of illness 34 months) and 20 age- and gender-matched healthy controls (HC; mean age 35.8 years) performed the Emotional Face N-Back (EFNBACK) task, a working memory task with emotional distracter stimuli. We used blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to measure neural activity in the dorsolateral (DLPFC) and ventrolateral prefrontal cortex (VLPFC), orbitofrontal cortex (OFC), ventral striatum and amygdala, using a region of interest (ROI) approach in SPM2.

RESULTS

rMDD patients exhibited significantly greater activity relative to HC in the left DLPFC [Brodmann area (BA) 9/46] in response to negative emotional distracters during high working memory load. By contrast, rMDD patients exhibited significantly lower activity in the right DLPFC and left VLPFC compared to HC in response to positive emotional distracters during high working memory load. These effects occurred during accurate task performance.

CONCLUSIONS

Remitted depressed patients may continue to exhibit attentional biases toward negative emotional information, reflected by greater recruitment of prefrontal regions implicated in attentional control in the context of negative emotional information.

Polyurie – Pathogenese, Diagnostik und Therapie

Die Diagnose Polyurie bietet ein breites Spektrum an Ursachen und Differentialdiagnosen. Die Bestimmung der 24-Stunden-Urinausscheidung ist obligat. Verschiedene extra- und intrarenale Defekte (zentraler versus nephrogener Diabetes insipidus) führen zur verminderten Fähigkeit der Urinkonzentration. Häufige Ursachen bei Erwachsenen bestehen durch toxische Medikamentenwirkungen (Lithium, Diuretika, Analgetika). Erkrankungen, die mit Hyperkalzämie oder Hypokaliämie einhergehen, können ebenso eine Polyurie auslösen. Chronisches und akutes Nierenversagen können bekanntermaßen mit polyurischen Phasen verlaufen. Die psychogene Polydipsie ist von erhöhtem renalen Wasserverlust zu differenzieren. Sind Kinder betroffen, muss an hereditäre Formen des renalen Diabetes insipidus gedacht werden. Durch systematische diagnostische Vorgehensweise ist die zugrunde liegende Erkrankung zu identifizieren und eine kausale Behandlung anzustreben. Ist eine kausale Behandlung nicht möglich, kann bei nicht ausreichender ADH-Seketion das ADH-Analogon Desmopressin (Minirin®) substituiert werden. Bei nicht ausreichender ADH-Wirkung müssen die Elektrolyt- und Harnstofflast reduziert (Diät) sowie Diuretika und NSAR therapeutisch eingesetzt werden, um die notwendige (elektrolytarme) zusätzliche Flüssigkeitszufuhr aus Gründen der Lebensqualität so gering wie möglich zu halten.

[Colonisation of the airways with ureaplasma urealyticum as a risk factor for bronchopulmonary dysplasia in VLBW infants?]

BACKGROUND

Chronic inflammatory processes contribute to the pathogenesis of bronchopulmonary dysplasia (BPD). We hypothesized colonisation with Ureaplasma urealyticum (Uu) as a possible reason for an increased risk of developing prolonged oxygen dependency > 28 days in very low birth weight (VLBW) infants.

PATIENTS AND METHODS

From January 1998 to November 1999 pharyngeal swabs were prospectively obtained and tested for Uu at birth and then weekly in VLBW infants. The following variables were compared between Uu-positive and Uu-negative infants: prenatal corticosteroids, maternal infections, mode of delivery, gestational age, birth weight, gender distribution, RDS, surfactant therapy, maximum inspiratory oxygen concentration during the first 24 and 48 hours, duration of oxygen supplementation beyond day 28, PDA, and weight differences during the first week of life.

RESULTS

Of a total of 74 infants, 17 were found to be Uu-positive. The latter group showed a lower mean gestational age (29; 25 - 37 vs. 28; 24 - 34 WOG; p = 0.02) and a longer duration of oxygen supplementation after day 28 (0; 0 - 121 vs. 5; 0 - 134 d; p = 0.02). All other variables did not differ significantly between both groups. Multivariate analyses identified the variables birth weight and colonisation with Uu as risk factors for a longer period of oxygen dependency after day 28 (p < 0.01; p = 0.05).

CONCLUSION

These data indicate a correlation between the colonisation with Uu and prolonged oxygen dependency > 28 days.

Effectiveness of twice-weekly pyrimethamine-sulfadoxine as primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmic encephalitis in patients with advanced HIV infection

The safety and efficacy of a fixed 25 mg pyrimethamine-500 mg sulfadoxine combination supplemented with 15 mg folinic acid twice a week as primary prophylaxis of Pneumocystis carinii pneumonia (PCP) and toxoplasmic encephalitis was evaluated in 106 patients infected with the human immunodeficiency virus. All patients had a CD4+ T-lymphocyte count of less than 100 cells/microl at study entry. Efficacy in this single-arm open-label prospective study was analyzed on an as-treated basis. No patient received highly active antiretroviral treatment, including protease inhibitors or non-nucleoside reverse transcriptase inhibitors, while on study medication. PCP developed in four patients, one of whom had been noncompliant. No PCP episode occurred in the first year. Probabilities of freedom from PCP were 0.97 (95%CI, 0.92-1) after 24 months and 0.93 (95%CI, 0.84-1) after 36 months. Of 74 (69.8%) patients positive for anti-toxoplasma IgG antibodies, one noncompliant patient developed toxoplasmic encephalitis after 24 months. Allergic reactions were observed in 18 (17%) patients and resulted in permanent discontinuation in 7 (6.6%) patients. One (0.9%) patient who had continued prophylaxis despite progressive hypersensitivity reactions developed a serious adverse reaction (Stevens-Johnson syndrome). The median survival of study participants was 29 months, with relentless progression of AIDS accounting for most deaths. The prophylaxis regimen studied appeared safe and effective for primary prophylaxis of PCP and toxoplasmic encephalitis. Severe adverse events can likely be prevented by discontinuation of prophylaxis at the time allergic reactions are noted. Rechallenge frequently results in tolerance. Efficacy and safety compare favorably with previously studied regimens. This simple prophylactic regimen may provide a convenient alternative for patients failing or intolerant to approved regimens.

Twice-weekly pyrimethamine-sulfadoxine effectively prevents Pneumocystis carinii pneumonia relapse and toxoplasmic encephalitis in patients with AIDS

OBJECTIVE

To evaluate the safety and efficacy of a fixed 25mg pyrimethamine--500mg sulfadoxine combination plus 15mg folinic acid given twice weekly for the prevention of relapses of Pneumocystis carinii pneumonia (PCP) and primary episodes of toxoplasmic encephalitis.

METHODS

Ninety-five HIV-infected patients with successfully treated PCP and without history of toxoplasmic encephalitis were enrolled between January 1990 and October 1995 in a single-arm open-label prospective study. No patient was receiving highly active antiretroviral treatment, including protease inhibitors or non-nucleoside reverse transcriptase inhibitors, while on study medication. Efficacy was analysed on an "as-treated" basis.

RESULTS

Five patients (5.3%) suffered a PCP relapse while on study medication, three of whom had been non-compliant. No relapse occurred in the first year. Probabilities of freedom from relapse were 0.96 after 24 months and 0.90 after 36 months. Of 69 patients positive for anti-toxoplasma IgG antibodies, one (1.5%) developed cerebral lesions compatible with toxoplasmic encephalitis after 50 months. Cutaneous allergic reactions were observed in 16 patients (16.8%) resulting in permanent discontinuation in six patients (6.3%). Two patients (2.1%) developed serious adverse reactions (Stevens-Johnson syndrome), both of whom had continued prophylaxis despite progressive hypersensitivity reactions.

CONCLUSIONS

The prophylactic regimen used is effective in preventing PCP relapses and toxoplasmic encephalitis. The regimen appears to be safe. Severe adverse events can likely be prevented by discontinuation of prophylaxis at the time allergic reactions are noted. Rechallenge frequently results in tolerance of the regimen. Efficacy and safety compare favourably with previously studied regimens. This simple prophylactic regimen may provide a convenient alternative for patients unable to tolerate approved regimens.

Spatial and temporal pattern analysis via spiking neurons

Spiking neurons, receiving temporally encoded inputs, can compute radial basis functions (RBFs) by storing the relevant information in their delays. In this paper we show how these delays can be learned using exclusively locally available information (basically the time difference between the pre- and postsynaptic spikes). Our approach gives rise to a biologically plausible algorithm for finding clusters in a high-dimensional input space with networks of spiking neurons, even if the environment is changing dynamically. Furthermore, we show that our learning mechanism makes it possible that such RBF neurons can perform some kind of feature extraction where they recognize that only certain input coordinates carry relevant information. Finally we demonstrate that this model allows the recognition of temporal sequences even if they are distorted in various ways.

Selective expansion of gammadelta T cells among liver-derived lymphocytes of AIDS patients with disseminated Mycobacterium avium complex infection

The aim of this study was to investigate a potential expansion of gammadelta T cells in AIDS patients in response to disseminated infection with Mycobacterium avium complex. Liver-derived lymphocytes and peripheral blood lymphocytes were obtained from 5 AIDS patients with disseminated Mycobacterium avium complex infection and 10 HIV-infected patients without mycobacterial disease. Control patients included 14 HIV-negative patients without bacterial disease and 4 HIV-negative patients with disseminated Mycobacterium tuberculosis infection. The percentage of gammadelta T cells among CD3+ T lymphocytes was determined by flow cytometry. gammadelta T cells were markedly enhanced in liver biopsies but not among peripheral blood lymphocytes of AIDS patients with disseminated M. avium complex infection (median liver gammadelta/CD3: 26%) as compared to HIV-infected control patients without mycobacterial disease (median liver gammadelta/CD3: 2.3%; P < 0,005). Disseminated infection with M. tuberculosis in HIV-negative patients leads to a similar expansion of gammadelta T cells among liver-derived CD3+ lymphocytes (median gammadelta/CD3: 15.5%) as compared to control patients without mycobacterial disease (median gammadelta/CD3: 2.15%; P < 0,001).

High-performance liquid chromatography determination of pyrimethamine, dapsone, monoacetyldapsone, sulfadoxine, and N-acetyl-sulfadoxine after rapid solid-phase extraction

A solid-phase extraction procedure and a corresponding high-performance liquid chromatographic technique based on methods previously published by Edstein et al. (Edstein M. Quantification of antimalarial drugs. I. Simultaneous measurement of sulphadoxine, N4acetylsulphadoxine and pyrimethamine in human plasma. J Chromatogr 1984;305:502-7; Edstein M. Quantification of antimalarial drugs. II. Simultaneous measurement of dapsone, monoacetyldapsone and pyrimethamine in human plasma. J Chromatogr 1984;307:426-31) were developed for simultaneous determination of either dapsone (DDS), monoacetyldapsone (MADDS), and pyrimethamine (PYR) or sulfadoxine (SDX), N-acetyl-sulfadoxine (NAS) and pyrimethamine in plasma. Solid-phase extraction was achieved using C-18 extraction columns. An ionpair chromatography was performed on a C-18 analytical column (mu Bondapak C-18, 300 x 3.9 mm I.D.). Gradient elution with methanol, acetonitrile, PIC B6 reagent (1-hexanesulphonic acid), and water as mobile phase was applied. Ultraviolet detection was done at 210 nm for PYR, at 254 nm for SDX and NAS, and at 295 nm for DDS and MADDS. The extraction recoveries averaged 92.1% for PYR, 87.6% for DDS, 87.5% for MADDS, 91.2% for SDX, and 92.4% for NAS. The limit of quantification using 1.0-ml plasma samples was 15 ng/ml for PYR, DDS, MADDS, NAS, and 25 ng/ml for SDX (precision < 15%).

Rifabutin versus placebo in combination with three drugs in the treatment of nontuberculous mycobacterial infection in patients with AIDS

The aim of this double-blind, randomized, placebo-controlled, 12-week study was to assess the efficacy of rifabutin (450 or 600 mg/d) in the treatment of disseminated nontuberculous mycobacterial infection in patients with AIDS. Companion drugs in both arms of the study were ethambutol, clofazimine, and isoniazid. Because of low accrual, the study was prematurely terminated when a total of 382 patients had been enrolled, of which 200 were eligible (i.e., their specimens were culture-positive for Mycobacterium avium complex [MAC] or Mycobacterium xenopi at baseline) and 102 were evaluable (i.e., they were eligible, were treated for a minimum of 6 weeks, and had at least one culture assessment after baseline). The original protocol called for a total of 220 evaluable patients. At week 12, rifabutin treatment was associated with higher, although nonsignificant, rates of bacteriologic conversion than was the placebo arm, with regard to both the eligible patients (25% vs. 18%) and the evaluable patients (45% vs. 38%). Corresponding median times to culture conversion were 42 vs. 63 days (eligible patients) and 43 vs. 69 days (evaluable patients). No significant difference was observed in clinical improvement, mortality, or toxicity between the two treatment arms. The addition of rifabutin to a triple-drug regimen may contribute to the clearance of disseminated MAC infection in patients with AIDS, without causing additional toxicity.