Tyrosine 62 of the gamma-aminobutyric acid type A receptor beta 2 subunit is an important determinant of high affinity agonist binding.

The gamma-aminobutyric acid type A receptor (GABA(A)R) carries both high (K(D) = 10-30 nm) and low (K(D) = 0.1-1.0 microm) affinity binding sites for agonists.

Regional myocardial perfusion after experimental subarachnoid hemorrhage.

Background And Purpose: The pathophysiology of cardiac injury after subarachnoid hemorrhage (SAH) remains controversial. Data from animal models suggest that catecholamine-mediated injury is the most likely cause of cardiac injury after SAH. However, researchers also have proposed myocardial ischemia to be the underlying cause, as a result of coronary artery disease, coronary artery spasm, or hypertension and tachycardia.

The effect of amlodipine on respiratory and pulmonary vascular responses to hypoxia in mountaineers.

Calcium antagonists are known to reduce the incidence of high-altitude pulmonary oedema, but the mechanism is unclear. The aim of this study was to examine the effects of the calcium antagonist, amlodipine, on cardiac and respiratory responses in normoxia and hypoxia. Fourteen normal subjects aged 31+/-4 yrs who had climbed to altitudes of 5,000-7,500 m without problems were randomly assigned to a double-blind crossover trial of amlodipine versus placebo, using sea-level inspiratory hypoxia to simulate altitude.

Distribution and severity of bronchiectasis in allergic bronchopulmonary aspergillosis (ABPA).

The purpose of this paper was to quantitate the distribution and severity of computed tomography (CT) and radiographic findings in patients with allergic bronchopulmonary aspergillosis (ABPA), probable ABPA, and asthmatic controls. Chest radiographs and high-resolution CT images were evaluated in 19 patients with documented ABPA and 18 asthmatic controls. Ten patients with probable ABPA were also evaluated.

Real-time three-dimensional electrical impedance imaging.

Electrical impedance tomography is a technology for producing images of internal body structures based upon electrical measurements made from electrodes on the body surface. Typically a single plane of electrodes is used, seeking to reconstruct a cross section of the body. Yet the majority of image reconstruction algorithms ignore the three-dimensional (3D) characteristics of the current flow in the body.

Risk factors for excess weight gain in children treated for acute lymphoblastic leukaemia.

Objective: To test whether excess weight gain in patients treated for childhood acute lymphoblastic leukaemia (ALL) was predictable using patient characteristics at diagnosis.

Design And Subjects: Longitudinal study of changes in body mass index (BMI) in all 98 patients treated in Scotland on treatment protocol MRC UKALL-XI who had reached at least 3y post-diagnosis in first remission.

Measurements: The influence of the following variables on changes in BMI, expressed as a standard deviation score (SDS), was tested using variable selection techniques and classification and regression trees: BMI SDS at diagnosis; age at diagnosis; gender; socioeconomic status; treatment.

Tuberculosis in Pakistan: socio-cultural constraints and opportunities in treatment.

This study explores the extent to which factors related to individuals, the care provision process, and the cultural context influence the behaviour of tuberculosis patients attending TB clinics in rural Pakistan, and examines the effects of disease on their personal lives. Thirty-six patients attending three TB treatment clinics were interviewed in depth. These patients were stratified by stage of treatment (treatment proceeding, treatment completed, default), sex and by rural/urban status.

Complications of exercise and pharmacologic stress tests: differences in younger and elderly patients.

Background: Age characteristics of patients undergoing various types of stress tests are important because of differences in clinical background and exercise performance between the young and elderly. Adverse effects of pharmacologic agents are known to be more common in the elderly, who are less able to perform vigorous exercise stress testing. We investigated the clinical background, performance characteristics, and complication rate of various stress tests in younger (<75 years old) and elderly (>75 years old) patient populations.

A reconstruction algorithm for electrical impedance tomography data collected on rectangular electrode arrays.

A three-dimensional reconstruction algorithm in electrical impedance imaging is presented for determining the conductivity distribution beneath the surface of a medium, given surface voltage data measured on a rectangular array of electrodes. Such an electrode configuration may be desirable for using electrical impedence tomography to detect tumors in the human breast. The algorithm is based on linearizing the conductivity about a constant value.

Unraveling the function of glycosyltransferases in Streptococcus thermophilus Sfi6.

Streptococcus thermophilus Sfi6 produces a texturizing exopolysaccharide (EPS) consisting of a -->3)[alpha-D-Galp-(1-->6)]-beta-D-Glcp-(1-->3)-alpha-D-GalpNAc-(1--> 3)-beta-D-Galp-(1--> repeating unit. We previously identified and analyzed a 14.5-kb gene cluster from S.

Echocardiographic determination of risk area size in a murine model of myocardial ischemia.

Genetically altered mice are useful to understand cardiac physiology. Myocardial contrast echocardiography (MCE) assesses myocardial perfusion in humans. We hypothesized it could evaluate murine myocardial perfusion before and after acute coronary ligation.

Pediatric diffuse lung disease: diagnosis and classification using high-resolution CT.

Objective: Our purpose was to categorize high-resolution CT findings in children with diffuse lung disease and to evaluate the accuracy of diagnoses made using CT.

Materials And Methods: The chest radiographs and high-resolution CT scans of 20 children (1-16 years old; median, 9 years old) with biopsy-proven chronic diffuse lung diseases were reviewed separately by two independent chest radiologists. Thirteen types of diffuse lung disease were included in the study.

Correlation of CT findings with clinical evaluations in 261 patients with symptomatic bronchiectasis.

Objective: In a multicenter study, we evaluated the relationships between the extent and severity of bronchiectasis on CT and clinical symptoms, spirometric abnormality, and sputum characteristics.

Subjects And Methods: The study population included 261 patients with symptomatic, physiologically significant bronchiectasis, who were enrolled in another study evaluating the clinical efficacy of deoxyribonudease in treatment of bronchiectasis. Patients with cystic fibrosis, allergic bronchopulmonary aspergillosis, and fungal or mycobacterial infection were excluded.

Use of polymerase chain reaction for citrate synthase gene to diagnose Bartonella quintana endocarditis.

We describe aortic valve endocarditis caused by Bartonella quintana in a 31-year-old man. The diagnosis was made on the basis of polymerase chain reaction amplification of the B quintana citrate synthase gene from cardiac valve tissue, the compatibility of histochemical stains of cardiac valve tissue, and serologic studies.

Introduction of the exopolysaccharide gene cluster from Streptococcus thermophilus Sfi6 into Lactococcus lactis MG1363: production and characterization of an altered polysaccharide.

Streptococcus thermophilus Sfi6 produces an exopolysaccharide (EPS) composed of glucose, galactose and N-acetylgalactosamine in the molar ratio of 1:2:1. The genes responsible for the EPS biosynthesis have been isolated previously and found to be clustered in a 14.5 kb region encoding 13 genes.

Genetic and environmental influences in the development of multiple primary melanoma.

Objectives: To identify risk factors and the prognosis associated with the development of multiple primary melanoma (MPM).

Design: Case-comparison studies of subjects with MPM and single primary melanoma. Sequencing of CDKN2A in germline DNA.

Incidence and occupational pattern of leukaemias, lymphomas, and testicular tumours in western Ireland over an 11 year period.

Study Objective: To determine incidence of the following malignancies, testicular tumours, all leukaemias and all lymphomas in the West of Ireland in an 11 year period. Secondly, to examine the relation between disease patterns and available occupational data in male subjects of working age.

Design: A census survey of all cases occurring in the three counties in the Western Health Board (WHB) area, Galway, Mayo and Roscommon, for the 11 year period 1980 to 1990 inclusive.

Cardiac outcome in patients with subarachnoid hemorrhage and electrocardiographic abnormalities.

Objective: Approximately 25% of patients with subarachnoid hemorrhage (SAH) have electrocardiographic (ECG) abnormalities consistent with myocardial ischemia or myocardial infarction (MI), and their cardiac prognosis remains unclear. The objective of this study was to determine the cardiac and all-cause mortality rate of a series of patients with SAH with ECG changes consistent with ischemia or MI.

Methods: Using an existing database of patients with SAH and predetermined ECG criteria for ischemia or MI, a study group of patients with abnormal ECG results within 3 days of presentation and before aneurysm surgery was identified.

An iterative Newton-Raphson method to solve the inverse admittivity problem.

By applying electrical currents to the exterior of a body using electrodes and measuring the voltages developed on these electrodes, it is possible to reconstruct the electrical properties inside the body. This technique is known as electrical impedance tomography. The problem is nonlinear and ill conditioned meaning that a large perturbation in the electrical properties far away from the electrodes produces a small voltage change on the boundary of the body.

Sequential changes in gas exchange following traumatic fat embolism.

We present a young man who developed fat embolism syndrome following a fractured femoral shaft. By intermittently measuring oxygen saturation with a pulse oximeter and varying the inspired partial pressure of oxygen we were able to quantify the development of shunt and ventilation/perfusion (V/Q) mismatch over the course of his illness. Shunt and low V/Q gradually improved in the week following admission but deteriorated following general anaesthesia for nailing of the femur.

An analysis of the geographical distribution of severe malaria in children in Kilifi District, Kenya.

Background: Although malaria is known to be a major cause of child mortality and morbidity throughout sub-Saharan Africa there are few detailed studies of malaria mortality rates and incidence of severe malarial disease in defined communities. We have studied the geographical pattern of admissions to hospital with severe malaria and the stability of this pattern over time in Kilifi District on the Kenyan Coast.

Methods: Over a 2-year period all children under 5 years of age with severe malaria admitted to the district hospital and living in a rural study population of about 50,000 people were identified.

Effect of electrode size on impedance images of two- and three-dimensional objects.

The sensitivity of an impedance imaging system to small cylindrical inhomogeneities in two-dimensional (2-D) and three-dimensional (3-D) saline tanks was studied for different height electrodes and different height targets. Experimental results were compared with analytical models. Inhomogeneities in the 3-D tank having limited vertical extent were detected by electrodes of vertical size comparable to that of the inhomogeneity.

A novel role for Rab5-GDI in ligand sequestration into clathrin-coated pits.

Background: Clathrin-coated pits are formed at the plasma membrane by the assembly of the coat components, namely clathrin and adaptors from the cytosol. Little is known about the regulation and mechanism of this assembly process.

Results: We have used an in vitro assay for clathrin-coated pit assembly to identify a novel component required for the invagination of newly formed coated pits.