Characterization of the C-terminal domains of intimin-like proteins of enteropathogenic and enterohemorrhagic Escherichia coli, Citrobacter freundii, and Hafnia alvei.

Surface proteins called intimins (Int), which are homologous to the invasin protein (Inv) of Yersinia spp., play a role in inducing brush border damage, termed attachment and effacement, which follows infection by enteropathogenic and enterohemorrhagic Escherichia coli, Citrobacter freundii biotype 4280, and Hafnia alvei. Maltose-binding protein (MBP) fusions containing the C-terminal 280 amino acids of Int-like proteins of strains of enteropathogenic E. coli, enterohemorrhagic E. coli, H. alvei, and C. freundii biotype 4280 and of Yersinia pseudotuberculosis Inv were constructed and purified. The 3' end of the gene for the H. alvei Int-like protein was sequenced and showed homology to corresponding regions of other Int-encoding genes. Binding of MBP-Int-like and MBP-Inv fusion proteins to HEp-2 cells was demonstrated by immunofluorescence microscopy and by fluorescence-activated cell sorting. MBP-Inv induced attachment and spreading of HEp-2 cells to plastic-coated wells, but MBP-Int-like fusion proteins did not. Preincubation of HEp-2 cells with MBP-Inv, but not with MBP-Int-like fusion proteins, inhibited MBP-Inv-induced cell attachment. Fixed staphylococci and fluorescent polymer microspheres coated with both MBP-Int-like and MBP-Inv fusion proteins showed enhanced adhesion to HEp-2 cells. These fusion proteins will facilitate studies of the role of intimin in the pathogenesis of diarrhea associated with members of the family Enterobacteriaeceae that induce attachment and effacement.     

GABAA receptor mediated elevation of Ca2+ and modulation of gonadotrophin-releasing hormone action in alphaT3-1 gonadotropes

gamma-amino butyric acid (GABA) is the major inhibitory neurotransmitter in the CNS, mediating fast inhibitory synaptic transmission, by activating GABAA receptors. However, these GABA-gated Cl- channels can also be excitatory, causing depolarization, and increasing Ca2+ entry via voltage-operated Ca2+ channels (VOCCs). Evidence exists for excitatory ionotropic GABA receptors in anterior pituitary cells, including gonadotropes, but these have not been directly characterized and their pharmacology remains controversial. Here we have measured the cytosolic Ca2+ concentration ([Ca2+]i) in alphaT3-1 gonadotropes, to test for expression of excitatory GABA receptors. The GABAA agonists, GABA and muscimol, both caused rapid, robust and dose-dependent increases in [Ca2+]i (EC50 values 2.7 and 1 microM), whereas the GABAB agonist, baclofen, did not. The GABAA antagonist, bicuculline, inhibited muscimol's effect, whereas the GABAB antagonist, phaclofen, did not. The neuroactive steroid 5alpha-pregnan-3alpha-ol-11,20-dione (an allosteric activator of GABAA receptors) increased [Ca2+]i, and this effect, like that of muscimol, was inhibited by picrotoxin. The muscimol effect on [Ca2+]i was blocked by the VOCC antagonist, nifedipine, or by Ca2+-free medium. When cells were pretreated with muscimol this increased the spike phase of the [Ca2+]i response to subsequent stimulation with gonadotropin-releasing hormone (GnRH). Similar amplification was seen in muscimol-pretreated cells stimulated with GnRH in Ca2+-free medium, but not when cells were pretreated with muscimol in Ca2+-free medium. The amplification was not, however, GnRH receptor-specific, because the spike response to ionomycin was also increased by muscimol pretreatment. These data provide the first direct evidence for expression of excitatory GABAA receptors, and the first demonstration of acute steroid effects, on GnRH-responsive pituitary cells. They also reveal a novel mechanism by which GABAA activation modulates GnRH action, raising the possibility that this may also influence gonadotrophin secretion from non-immortalized gonadotropes.     

P wave dispersion is prolonged in patients with Wilson＇s disease

AIM： To investigate the P wave dispersion as a noninvasive marker of intra-atrial conduction disturbances in patients with Wilson＇s disease.
METHODS： We compared Wilson＇s disease patients （n = 18） with age matched healthy subjects （n = 15） as controls. The diagnosis was based on clinical symptoms, laboratory tests （ceruloplasmin, urinary and hepatic copper concentrations）. P wave dispersion, a measurement of the heterogeneity of atrial depolarization, was measured as the difference between the duration of the longest and the shortest P-waves in 12 lead electrocardiography.
RESULTS： All the patients were asymptomatic on cardiological examination and have sinusal rhythm in electrocardiography. Left ventricular and left atrial diameters, left ventricular ejection fraction and left ventricular mass index were similar in both groups. The Wilson＇s disease patients had a significantly higher P wave dispersion compared with the controls （44.7 ± 5.8 vs 25.7 ± 2.5, P 〈 0.01）.
CONCLUSION： There was an increase in P wave dispersion in cardiologically asymptomatic Wilson＇s disease patients which probably represents an early stage of cardiac involvement.     

Quantitative evaluation of right ventricle function by transthoracic echocardiography in childhood congenital heart disease patients with pulmonary hypertension

Introduction and Objective: The present study aims to quantitatively evaluate the right ventricle (RV) function by means of transthoracic echocardiography in normal children and childhood congenital heart disease patients with pulmonary hypertension. Patients and Methods: This study was conducted in a cohort including 40 healthy children and 30 pediatric patients with pulmonary hypertension who were diagnosed under close surveillance at the study center between October 2009 and November 2010. Results: Statistically significant differences were found between the patient and control groups for the right ventricle myocardial performance index (RVMPI), the left ventricle myocardial performance index (LVMPI), the tricuspid valve systolic flow velocity (Ts), the ratio of systolic pulmonary artery pressure to the right ventricle outflow tract systolic flow velocity time integral (sPAP/RVOT VTI), and the ratio of systolic pulmonary artery pressure to right ventricle outflow tract systolic flow velocity time integral × heart rate (sPAP/[RVOT VTI×HR]). When the children were divided into three groups based on their pulmonary vascular resistance significant differences emerged that predicted an increasing severity of RV dysfunction. Significant differences were also observed for the RVMPI, the LVMPI, and the Ts as well as for echocardiographic pulmonary flow (Qp) and systemic flow (Qs). Discussion: The present study demonstrates that echocardiographic parameters can be used for the quantitative detection of RV dysfunction in childhood congenital heart disease patients with high pulmonary artery pressure (systolic, diastolic, and mean) or pulmonary vascular resistance.     

The burden of amyloidosis on the gastrointestinal tract of an ankylosing spondylitis patient

We present a 26-year-old man with edema, ascites and bloody diarrhea that later proved to be due to gastrointestinal and renal amyloidosis. Interestingly, he was also diagnosed as having ankylosing spondylitis,-possibly after a delay of 12 years. The obscure diagnosis and challenging treatment of secondary amyloidosis are further discussed.Electronic Supplementary Material Supplementary material (with figures in color) is available in the online version of this article at .Abbreviations AS ankylosing spondylitis     

Implementing a resource management program for accreditation process at the medical laboratory

ObjectivesTo plan for and provide adequate resources to meet the mission and goals of a medical laboratory in compliance with the requirements for laboratory accreditation by Joint Commission International.Design and methodsThe related policies and procedures were developed based on standard requirements for resource management.ResultsCompetency assessment provided continuing education and performance feedback to laboratory employees. Laboratory areas were designed for the efficient and safe performance of laboratory work. A physical environment was built up where hazards were controlled and personnel activities were managed to reduce the risk of injuries. An Employees Occupational Safety and Health Program (EOSHP) was developed to address all types of hazardous materials and wastes. Guidelines were defined to verify that the methods would produce accurate and reliable results.ConclusionsAn active resource management program will be an effective way of assuring that systems are in control and continuous improvement is in progress.     

Health screening for Gurkha families in UK by chest X-ray, Heaf and blood testing: is it worthwhile?

This paper reports the chest X-rays, Heaf tests and haematology findings on a population of Gurkha wives and their children who arrived in the UK to accompany their husbands on an army base in 1997-8. The conclusions from this study are that there is no benefit from performing chest X-rays, but that screening for rubella and iron deficiency anaemia should continue.