Strong Association Between Shiga Toxin-Producing Escherichia coli O157 and Virulence Genes stx 2 and eae as Possible Explanation for Predominance of Serogroup O157 in Patients with Haemolytic Uraemic Syndrome

The aim of this study was to investigate the association between Shiga toxin-producing Escherichia coli (STEC) O157 and the simultaneous presence of the virulence genes stx ₂ and eae in STEC from patients with gastroenteritis. In Germany, the proportion of serogroup O157 is substantially higher among STEC isolates from patients with haemolytic uraemic syndrome (HUS) than among STEC isolates from patients with gastroenteritis. The reason for this is unknown. Independent of serogroup, the virulence genes stx ₂ and eae have been associated with severe disease. Data collected in 2000–2001 from a Germany-wide laboratory-based surveillance system for STEC-associated gastroenteritis in patients <15 years were analysed. Overall, 18% of the STEC isolates belonged to serogroup O157. Compared with non-O157 strains, 0157 isolates were strongly associated with the simultaneous presence of both an stx ₂ gene and the eae gene (OR, 76; 95%CI, 27–230). Within the subset of STEC isolates that carried both virulence genes, 60% belonged to serogroup O157, a proportion similar to that found in STEC isolates from pediatric patients with HUS in Germany and Austria (67%, P=0.35). These data suggest that the more frequent carriage of both virulence genes, i.e. stx ₂ and eae, forms the basis of why STEC O157 predominates in patients with HUS.     

Irreversible H2-antagonism of the four isomeric butyl analogues of mifentidine

It has been hypothesized that bidentate hydrogen bonding plays an important role in the interaction of imidazolylphenylformamidines with the H₂-receptor. The present study, in which the degree of pseudoirreversible H₂-antagonism of the four isomeric butyl substituted mifentidine analogues was determined on the spontaneously beating right atrium of the male guinea-pig, lends further support to this hypothesis. In solution the EE/EZ ratio is different for the four isomeric butylated mifentidine analogues. The rank order of the percentage of E,E conformation, which favors a bidentate interaction, of the formamidine moiety parallels the rank order of pseudo-irreversible H₂-antagonism.     

Simulation Studies of Latency Measures of Components of the Event-Related Brain Potential

We compared the accuracy of P300 latency estimates obtained with different procedures under several simulated signal and noise conditions. Both preparatory and signal detection techniques were used. Preparatory techniques included frequency filters and spatial filters (single electrode selection and Vector filter). Signal detection techniques included peak-picking, cross-correlation, and Woody filter. Accuracy in the latency estimation increased exponentially as a function of the signal-to-noise ratio. Both Woody filter and cross-correlation provided better estimates than peak-picking, although this advantage was reduced by frequency filtering. For all signal detection techniques, Vector filter provided better estimates than single electrode selection. Large component overlap impaired the accuracy of the estimates obtained with both single electrode selection and Vector filter, but with Vector filter impairment occurred only when the overlapping component had a scalp distribution that was similar to the scalp distribution of the signal component. The effects of varying noise characteristics, P300 duration and latency, and the parameters of Vector filter were also investigated.     

Familial testicular cancer: interest in genetic testing among high-risk family members.

PURPOSE: This study is part of an ongoing National Cancer Institute multidisciplinary, etiologically-focused, cross-sectional study of Familial Testicular Cancer (FTC). The current report targets interest in clinical genetic testing for susceptibility to FTC. METHODS: Demographics, knowledge, health beliefs, and psychological and social factors were evaluated as covariates related to interest in genetic testing. RESULTS: The majority (66%) of 229 participants (64 affected men, 66 unaffected men, and 99 women) from 47 multiple-case FTC families expressed interest in having a genetic test within 6 months, should such a test become available. Interest was similar among the three subgroups mentioned above. Worries about insurance discrimination based on genetic test results were associated with a significantly lower interest in testing. Alternatively, participants were more likely to be interested in genetic testing if they were younger and had higher levels of family support, a physician's recommendation supporting testing, cancer distress, and a need for information to inform the health care of their children. CONCLUSIONS: This study reveals social and relationship factors that FTC survivors and their relatives considered important when contemplating the use of new genetic technologies. This is the first study describing hypothetical interest in genetic testing for familial testicular cancer.     

Effects of sorbent suspension dialysis on plasma amino acid levels in cirrhotic patients with refractory hepatic encephalopathy

In cirrhotic patients, plasma amino acid levels are severely deranged. A decreased ratio of branched-chain to aromatic amino acids (Fischer ratio) has been implicated in the pathogenesis of hepatic encephalopathy. In this prospective study, we investigated the effects of extracorporeal detoxification on amino acid levels using a sorbent suspension dialysis system. Twenty patients with documented cirrhosis and hepatic encephalopathy grade II-III not responding to standard treatment were randomized to receive either six hours of sorbent dialysis and standardized conventional medical treatment or ongoing medical treatment alone. In contrast to previous uncontrolled studies, no significant effect on amino acid levels, Fischer ratio or clinical grade of hepatic encephalopathy was detected in either treatment group. In conclusion, a 6-hour treatment with sorbent dialysis did not significantly influence plasma levels of amino acids and did not ameliorate the clinical grade of hepatic encephalopathy.     

Impact of an American board of pediatrics maintenance of certification (MOC) on weight-related counseling at well-child check-ups

Objective

The Healthy Weight Counseling Maintenance of Certification (MOC) program integrates pediatrician training and clinic changes to promote use of evidence-based, diet and physical activity (PA) health messages and counseling strategies. This interrupted time series study assessed the impact of this MOC program on provision of weight-related counseling.

In vitro diagnosis of chronic nasal inflammation

BACKGROUND: Differential diagnosis of chronic nasal inflammation is insufficient when based solely on clinical examination and radiography of paranasal sinuses. Patients complain about more or less similar symptoms. Activation of mast cells and eosinophils is pivotal in nasal inflammation. OBJECTIVE: To compare tryptase and eosinophilic cationic protein (ECP) in nasal secretions in different forms of chronic nasal inflammation and to establish norm values. METHODS: The study included 1710 patients presenting with nasal complaints. Nasal secretions were gained by the cotton wool method and analysed for tryptase, as a marker of mast cell activation, and for ECP, as a marker of tissue eosinophilia and activation. Patients were grouped according to their diagnosis: chronic, non-allergic rhinosinusitis (sinusitis, n=194), non-allergic nasal polyposis (polyposis, n=138), non-allergic rhinitis with eosinophilia syndrome (NARES, n=198), isolated perennial allergic rhinitis (AR) (n=126), isolated seasonal AR (n=132), and patients allergic to both, seasonal and perennial allergens (n=193). Seven hundred and twenty-nine patients with nasal complaints due to a deviated septum and without any nasal inflammation served as controls. RESULTS: Nasal tryptase was highly significantly (P<0.001) elevated in polyposis, NARES, and in AR. ECP was highly significantly (P<0.001) elevated in all groups of patients suffering from chronic nasal inflammation. Based on our data and method we established norm values (95% confidence interval of mean value) for nasal tryptase in healthy adults, ranging from 12.0 to 18.7 ng/mL and for ECP ranging from 84.4 to 102.6 ng/mL. CONCLUSION: Mast cells and eosinophils are involved in non-allergic and allergic forms of chronic nasal inflammation. We established an in vitro assay for tryptase and ECP in nasal secretions and defined norm values based on our data and method. In vitro measurement of biological markers in nasal secretions provides important information for differential diagnosis and therapeutic strategies of chronic nasal inflammation.     

Polarized ion transport during migration of transformed Madin-Darby canine kidney cells

Epithelial cells lose their usual polarization during carcinogenesis. Although most malignant tumours are of epithelial origin little is known about ion channels in carcinoma cells. Previously, we observed that migration of transformed Madin-Darby canine kidney (MDCK-F) cells depended on oscillating K⁺ channel activity. In the present study we examined whether periodic K⁺ channel activity may cause changes of cell volume, and whether K⁺ channel activity is distributed in a uniform way in MDCK-F cells. After determining the average volume of MDCK-F cells (2013±270 m³; n=8) by means of atomic force microscopy we deduced volume changes by calculating the K⁺ efflux during bursts of K⁺ channel activity. Therefore, we measured the membrane conductance of MDCK-F cells which periodically rose by 22.3±2.5 nS from a resting level of 6.5±1.4 nS (n=12), and we measured the membrane potential which hyperpolarized in parallel from –35.4±1.2 mV to –71.6±1.8 mV (n=11). The distribution of K⁺ channel activity was assessed by locally superfusing the front or rear end of migrating MDCK-F cells with the K⁺ channel blocker charybdotoxin (CTX). Only exposure of the rear end to CTX inhibited migration providing evidence for horizontal polarization of K⁺ channel activity in transformed MDCK-F cells. This is in contrast to the vertical polarization in parent MDCK cells. We propose that the asymmetrical distribution of K⁺ channel activity is a prerequisite for migration of MDCK-F cells.     

Space-based inhibition of return in children with spina bifida

Inhibition of return (IOR) refers to an increase in time to react to a target in a previously attended location. Children with spina bifida meningomyelocele (SBM) and hydrocephalus have congenital dysmorphology of the midbrain, a brain region associated with the control of covert orienting in general and with IOR in particular. The authors studied exogenously cued covert orienting in 8- to 19-year-old children and adolescents (84 with SBM and 37 age-matched, typically developing controls). The exogenous cue was a luminance change in a peripheral box that was 50% valid for the upcoming target location. Compared with controls, children with SBM showed attenuated IOR in the vertical plane, a deficit that was associated with midbrain dysmorphology in the form of tectal beaking but not with posterior brain volume loss. The data add to the emerging evidence for SBM deficits in attentional orienting to salient information.