Dentistry, neurology and nephrology--what is the connection?

Case report A 28-year-old female patient was admitted because of painlessmacroscopic haematuria. Past history included severe mentalretardation and nystagmus. At age 17, a computed tomography(CT) scan of the brain showed an absent cerebellar vermis andcerebellar hypoplasia. There was no     

Psychopharmacological possibilities in the acute disaster setting.

This article focuses on possible psychopharmacological interventions in the immediate post disaster setting. As there is little evidence for the efficacy or effectiveness of such interventions-given the difficulty in performing randomized, double-blind, placebo controlled studies with these populations-the article will delineate the neurobiological basis for pathological sequelae and theoretical drug interventions targeting putative disease mechanisms.     

Intracellular survival of persistent group A streptococci in cultured epithelial cells

Group A streptococcus (GAS) is the principle etiologic agent of bacterial pharyngotonsillitis and a wide range of other diseases. Failure to eradicate GAS from patients has been documented in 5-30% of patients with pharyngotonsillitis, in spite of the continued sensitivity of GAS to penicillin and other beta-lactams. It was recently proposed that eradication failure might be attributed to the ability of GAS to maintain an intracellular reservoir during antibiotic treatment. We have previously shown that strains derived from patients with bacterial eradication failure, despite antibiotic treatment (persistent strains), adhered to and were internalized by cultured epithelial cells more efficiently than strains that were successfully eradicated. Since, penicillin and other beta-lactams do not penetrate well into mammalian cells, intracellular survival of GAS is crucial in order to persist during prolonged antibiotic treatment. In this study, we compared the survival of GAS strains from cases of eradication failure and eradication success, using an epithelial cell culture model. We found that persistent strains show significantly increased intracellular survival, compared to the 'eradication success' strains. This finding supports the idea that an intracellular reservoir of GAS plays a role in the etiology of antibiotic eradication failure.     

PCR detection of amplified 132 bp repeats in Marek's disease virus type 1 (MDV-1) DNA can serve as an indicator for critical genomic rearrangement leading to the attenuation of virus virulence

A radioactive PCR test was developed that amplified the very virulent Marek's disease virus-1 (vvMDV-1) DNA sequence containing the 132 bp repeats. In apathogenic MDV-1 (CVI 988, Rispens), amplified DNA bands containing multiple copies of 132 bp repeats were identified. In the present study this PCR technique was used to monitor the passage level of vvMDV-1 in chicken embryo fibroblasts (CEF) in which the number of tandem 132 bp repeats was increased. It was found that at passage level 32 of vvMDV-1-B isolate, the 132 bp tandem repeat was already markedly amplified and its pattern resembled that of the MDV-1 (CVI 988, Rispens) vaccine virus DNA. In the vvMDV-1Z strain, amplification of the 132 bp repeat was not detectable at a similar passage level. The PCR test demonstrated that the apathogenic MDV-1 Md11/75c virus developed by extensive in vitro passaging has amplified 132 bp DNA repeats similar to those of the commercial vaccine virus (CVI 988, Rispense). It was also found that the pattern of viral RNA from infected cells detectable by Northern blot hybridization was markedly changed from a 2.4 kb RNA species in cells infected with vvMDV-1 viruses, to four RNA species (ranging from 2.2 to 4.4 kb) in cells infected with passage 32 of MDV-1-B strain, to a very large number of undefined RNA species synthesized in cells infected with attenuated MDV-1 viruses (CVI 988, Rispens and Md 11/75c).     

The incidence of deafness is non-randomly distributed among families segregating for Waardenburg syndrome type 1 (WS1).

Waardenburg syndrome (WS) is caused by autosomal dominant mutations, and is characterised by pigmentary anomalies and various defects of neural crest derived tissues. It accounts for over 2% of congenital deafness. WS shows high variability in expressivity within families and differences in penetrance of clinical traits between families. While mutations in the gene PAX3 seem to be responsible for most, if not all, WS type 1, it is still not clear what accounts for the reduced penetrance of deafness. Stochastic events during development may be the factors that determine whether a person with a PAX3 mutation will be congenitally deaf or not. Alternatively, genetic background or non-random environmental factors or both may be significant. We compared the likelihoods for deafness in affected subjects from 24 families with reported PAX3 mutations, and in seven of the families originally described by Waardenburg. We found evidence that stochastic variation alone does not explain the differences in penetrances of deafness among WS families. Our analyses suggest that genetic background in combination with certain PAX3 alleles may be important factors in the aetiology of deafness in WS.