Tunneling spectroscopy in small grains of superconducting MgB(2).

We report on tunneling spectroscopy experiments in small grains of the new binary intermetallic superconductor MgB(2). Experiments have been performed at 2.5 K using a low temperature scanning tunneling microscope.

Bioequivalence of two lamivudine tablet formulations.

The present study describes the determination of the bioavailability of a new commercial tablet formulation of lamivudine (CAS 134678-17-4) compared with a reference formulation. The comparative bioequivalence of the test and a reference formulation (each 3 x 150 mg) was assessed in 24 healthy volunteers by means of a randomized two-way crossover design. Prior to the study both the test and reference formulations were examined for conformation to chromatographic purity and drug content.

Evoked potentials for the evaluation of latent hepatic encephalopathy in pediatric liver transplant candidates.

Background: Visual evoked potentials (VEPs) and brain stem auditory evoked potentials (BAEPs) have been proposed as tools in the diagnosis of subclinical hepatic encephalopathy (HE). However, little information exists to determine their usefulness in pediatric patients. This study was undertaken to evaluate both methods in the detection of subclinical HE in pediatric liver transplant candidates.

Effects of random fields in an antiferromagnetic Ising spin glass.

The effects of random fields on the two-sublattice infinite-ranged Ising spin-glass model are investigated. This model is expected to be appropriate as a mean-field description of antiferromagnetic spin glasses such as FexMn1-xTiO3. Within replica-symmetric calculations, we study the influence of Gaussian and bimodal random fields on the phase transitions and phase diagrams.

Efficacy of IV aminophylline as a supplemental therapy in moderate broncho-obstructive crisis in infants and preschool children.

The aim of the present study was to investigate the efficacy of iv aminophylline as a supplemental therapy for wheezy infants and preschool children who still present moderate broncho-obstruction after treatment with nebulized fenoterol. A prospective randomized, double blind, placebo-controlled trial was conducted in a Paediatric Emergency Room. The major selection criteria for patients>> inclusion were age between 1 and 7 years, a wheezy episode lasting less than 2 days which failed to respond to three sequential fenoterol nebulizations, a Wood-Downes score between 3 and 6, and a history of at least two similar episodes.

BCR-ABL tyrosine kinase activity regulates the expression of multiple genes implicated in the pathogenesis of chronic myeloid leukemia.

The BCR-ABL chimeric protein is thought to play a central role in the pathogenesis of Philadelphia (Ph) chromosome-positive leukemias, notably chronic myeloid leukemia (CML). There is compelling evidence that malignant transformation by BCR-ABL is critically dependent on its protein tyrosine kinase (PTK) activity. As a result, multiple signaling pathways are activated in a kinase-dependent manner, and thus the activation of such pathways may affect the expression of genes that confer the malignant phenotype.

Heated humidification or face mask to prevent upper airway dryness during continuous positive airway pressure therapy.

Study Objectives: The objectives of this study were (1) to evaluate the way in which nasal continuous positive airway pressure (CPAP) therapy influences the relative humidity (rH) of inspired air; and (2) to assess the impact on rH of the addition of an integrated heated humidifier or a full face mask to the CPAP circuitry.

Design: The studies were performed in 25 patients with obstructive sleep apnea syndrome receiving long-term nasal CPAP therapy and complaining of nasal discomfort. During CPAP administration, temperature and rH were measured in the mask either during a night's sleep for 8 patients or during a daytime study in which the effects of mouth leaks were simulated in 17 patients fitted with either a nasal mask (with or without humidification) or a face mask alone.

Expiratory washout versus optimization of mechanical ventilation during permissive hypercapnia in patients with severe acute respiratory distress syndrome.

The aim of this study was to compare three ventilatory techniques for reducing PaCO2 in patients with severe acute respiratory distress syndrome treated with permissive hypercapnia: (1) expiratory washout alone at a flow of 15 L/min, (2) optimized mechanical ventilation defined as an increase in the respiratory frequency to the maximal rate possible without development of intrinsic positive end- expiratory pressure (PEEP) combined with a reduction of the instrumental dead space, and (3) the combination of both methods. Tidal volume was set according to the pressure-volume curve in order to obtain an inspiratory plateau airway pressure equal to the upper inflection point minus 2 cm H2O after setting the PEEP at 2 cm H2O above the lower inflection point and was kept constant throughout the study. The three modalities were compared at the same inspiratory plateau airway pressure through an adjustment of the extrinsic PEEP.

A scanographic assessment of pulmonary morphology in acute lung injury. Significance of the lower inflection point detected on the lung pressure-volume curve.

The goal of this study was to assess lung morphology in patients with acute lung injury according to the presence or the absence of a lower inflection point (LIP) on the lung pressure-volume (P-V) curve and to compare the effects of positive end-expiratory pressure (PEEP). Eight patients with and six without an LIP underwent a spiral thoracic CT scan performed at zero end-expiratory pressure (ZEEP) and at two levels of PEEP: PEEP1 = LIP + 2 cm H2O and PEEP2 = LIP + 7 cm H2O, or PEEP1 = 10 cm H2O and PEEP2 = 15 cm H2O in the absence of an LIP. The volumes of air and tissue within the lungs were measured from the gas-tissue ratio and the volumes of overdistended and normally, poorly, and nonaerated lung areas were determined by the analysis of the frequency histogram distribution.

A simple automated method for measuring pressure-volume curves during mechanical ventilation.

Measurement of respiratory compliance is advocated for assessing the severity of acute respiratory failure (ARF). Recently, the administration of an automated constant flow of 15 L/min was proposed as a method easier to implement at the bedside than supersyringe or inspiratory occlusions methods. However, pressure-volume (P-V) curves were shifted to the right because of the resistive properties of the respiratory system.

A lung computed tomographic assessment of positive end-expiratory pressure-induced lung overdistension.

The aim of this study was to assess positive end-expiratory pressure (PEEP)-induced lung overdistension and alveolar recruitment in six patients with acute lung injury (ALI) using a computed tomographic (CT) scan method. Lung overdistension was first determined in six healthy volunteers in whom CT sections were obtained at FRC and at TLC with a positive airway pressure of 30 cm H2O. In patients, lung volumes were quantified by the analysis of the frequency distribution of CT numbers on the entire lung at zero end-expiratory pressure (ZEEP) and PEEP.

[Management of AIDS during traditional hospitalization and at outpatient clinics in Recife (Brazil)].

The management of 50 AIDS patients by traditional hospital admission (25 cases) and outpatient clinics (25 cases) was studied between August and November 1995 in the Department of Infectious and Parasitic Diseases of the Federal University Hospital. The most costly items of expenditure were hospital services and consumable materials. Comparison of costs was complicated by differences in clinical status of the patients in the two groups.

[Continuous nebulization with terbutaline sulfate under tent inhalation. Evaluation of the efficacy in children 2 to 5 years of age in asthmatic crises].

This study investigated the efficacy of a system for continuous nebulization of terbutaline sulphate in the treatment of acute asthmatic crises in children. The equipment consisted of a condensation nebulizer attached to a 40 liter acrylic tent placed around the patient's head. A prospective, randomized and open clinical trial was conducted.

[Follow-up of pediatric patients evaluated for liver transplantation].

Objective: To analyze the evolution of pediatric patients chosen for hepatic transplantation.

Methods: A review was made of the clinical charts of the first 65 children and adolescents with chronic liver disease, aged 5 months to 19 years (X = 6.8%), chosen for liver transplantation during the period of August 1994 to March 1996.

[Management of febrile infants younger than 2 months of age at the Emergency Care Unit: diagnosis aspects and therapeutics].

82 febrile young infants were studied, prospectively, at the Emergency Service in Hospital Universitário-University of São Paulo. All the children were kept at the Emergency ward for 24 hours. Clinical and laboratory investigations were performed and when necessary, administration of antibiotic agents were started.

Reversed metal replicas of freeze-dried proteins to be visualized with the scanning tunneling microscope.

Scanning tunneling microscopy of metal-coated specimens has become a reliable technique that permits direct three-dimensional visualization of structural details at a level at which individual subunits in protein complexes or even single domains of proteins can be resolved. We describe in this paper a variation of the freeze-drying metal coating procedure that allows us to image with the STM the inner side of the metal replica, previously in contact with the protein molecules. We have tested this new approach with two different well characterized protein systems: freeze-dried two-dimensional crystals of bacteriophage phi 29 connector and the vesicle form of two-dimensional crystals of cytochrome oxidase from beef heart mitochondria.

[Myocardial revascularization in left coronary trunk lesion in patients over 65 years old].

Purpose: To study the short and long-term follow-up of patients with left main coronary artery disease (LMCAD) and age over 65 years, by comparing the results with patients under 65 years-old.

Methods: Twenty-two patients with LMCAD and mean age of 69 +/- 3.5 years (group I) were underwent isolated coronary artery bypass grafting (CABG) and compared to 31 patients with LMCAD, mean age of 54 +/- 7 years (group II), who also underwent isolated CABG.