Sequence of a novel HLA-A*0301 intronic variant (A*03010103)

We report here the full-length sequence of a novel HLA-A*0301 allele, A*03010103, which differs from A*03010101 by a single nucleotide substitution (G>T) at position 492 within intron 2. The variant was originally identified by Reference Strand-mediated Conformational Analysis (RSCA) and was confirmed by cloning and sequencing. The difference in RSCA mobility between A*03010101 and A*03010103 demonstrates the sensitivity of RSCA to detect single nucleotide polymorphisms.     

Temporal pattern of herpes simplex virus type 1 infection and cell death in the mouse brain stem: influence of guanosine nucleoside analogues

Levels of bystander death occurring in herpes simplex virus type 1 (HSV-1)-infected mouse brain stems were studied, as well as the extent to which bystander death is influenced by guanosine nucleoside analogue treatment. Consecutive sections from brain stems of HSV-1-infected mice were stained alternately for (i) viral infection and (ii) cell death (TUNEL assay). Virus antigen was detectable in brain stems on day 3 of infection, while TUNEL staining was comparatively lower. An increase in the extent of TUNEL staining was observed on day 4 of infection. Despite this increase, however, the ratio of TUNEL-stained to infection marker-stained tissue still indicated that the amount of TUNEL staining remained lower than infection staining at this time point. On days 5 and 6 of infection, TUNEL staining continued to increase and the TUNEL/infection marker ratio switched on day 6 in favour of excess TUNEL staining, which was observed in and around the foci of infection, suggesting bystander death. The excess TUNEL staining on day 6 of infection was further increased on treatment with antivirals. The significance and implications of these results are discussed with respect to the nature and mechanism of action of the TUNEL assay, dynamics of primary HSV-1 infection, immunological influences and potential effects of antiviral treatment. The potential problems of the TUNEL assay are considered in the context of viral infection and the TUNEL assay, in combination with infection marker staining, may potentially provide a model system for quantitative analysis of true bystander death during HSV infection in vivo.     

Cell-free translation of tobacco vein mottling virus RNA

Tobacco vein mottling virus (TVMV), a member of the potyvirus group, was translated in a rabbit reticulocyte cell-free system. The RNA was approximately 5% as active as rabbit globin mRNA in directing protein synthesis. Translation was stimulated approximately 15% by the cap analog pppm7G, a phenomenon which has also been observed with uncapped viral RNAs. Treatment with NaIO4 and NaB(3H]4 under conditions which label the caps of globin and ovalbumin mRNA failed to produce labeled cap structures in TVMV RNA. Approximately 20 polypeptides, ranging from 20,000 to 100,000 daltons, were produced in the reticulocyte system programmed with TVMV RNA. The predominant species (P75) had a molecular weight of 75,000. The same major polypeptides were produced in the wheat germ system, but there was relatively greater synthesis of the smaller polypeptides. Incubation of the reticulocyte system in the presence of cycloheximide following an initial period of synthesis failed to cause breakdown of larger polypeptides into smaller polypeptides. Preincubation of TVMV RNA with the reticulocyte system before addition of labeled amino acids caused greater synthesis of the smaller polypeptides, suggesting that they are derived from fragments of the RNA produced during the incubation. Translation of TVMV RNA which had been bound to oligo(dT)-cellulose yielded nearly the same spectrum of polypeptides, but synthesis of polypeptides smaller than 52,000 daltons was reduced. At low ionic strength, only polypeptides of 52,000 daltons and smaller were synthesized. At high ionic strength, P75 was essentially the only product synthesized. Antibody to whole virus precipitated many of the polypeptides, including P75, suggesting that they contain the coat protein sequence. No polypeptide with the electrophoretic mobility of authentic coat protein, however, was precipitated. Comparison of partial proteolytic digests of P75 and authentic coat protein provided further evidence for sequence homology.     

Lay Attitudes toward Genetic Testing for Susceptibility to Inherited Diseases

One of the most important issues facing legal and medical policy makers in the coming years will be whether to employ populationbased testing for genetic markers of inherited diseases. Two hundred and twenty-six randomly selected individuals from Easton, Pennsylvania completed a mail questionnaire that was designed to assess the general public's attitudes toward many of the personal and societal issues surrounding genetic testing for disease susceptibility. Respondents were generally optimistic about the potential benefits of genetic testing, and their attitudes about genetic testing were associated with their personal interest in getting a genetic test. Respondents were more likely to be interested in undergoing genetic testing for disease susceptibility if they might have some control over the targeted disease (i.e. there was a cure) and if the test was highly predictive of their chances of developing the disease. Respondents were wary of granting access to genetic testing results to anyone other than doctors and family members, and they did not want the government, religious leaders, or the courts involved in regulating genetic testing. These results have important implications for psychologists, genetic scientists, bioethicists, and legal scholars who are grappling with the many issues related to population-based genetic testing for inherited diseases.     

"Acadian" and "classical" forms of Friedreich ataxia are most probably caused by mutations at the same locus

"Acadian ataxia" is a form of Friedreich ataxia found in individuals of Acadian ancestry. It was described by Barbeau (in Sobue I (ed): Spinocerebellar Degeneration; Tokyo: Univ. Tokyo Press, pp 121-142, 1980) as having a slower course of degeneration and less severe secondary symptoms than "classical" Friedreich ataxia. He suggested that these 2 forms of the disease may be distinct. The mutation causing "classical" Friedreich ataxia has recently been mapped to chromosome 9 through genetic linkage studies, and here we show that the locus causing Friedreich ataxia in Acadian families from southwestern Louisiana is tightly linked to the same DNA marker, D9S15. Thus, these 2 disorders, which may be differentiated clinically, are most probably due to mutation(s) at the same locus on chromosome 9.     

Diversity of aminoglycoside resistance inEnterobacter cloacae in Greece

NinetyEnterobacter cloacae strains isolated from 12 Greek hospitals were examined in terms of epidemiological types and resistance mechanisms. Using O serotyping 69 % of the strains were assigned to a specific serotype and overall 16 different serotypes were identified. The combination of serotyping, phagetyping and biotyping efficiently discriminated most of the strains, indicating that single epidemic strains were not prevalent, although serotypes 3, 7, and group II predominated. Eight representative strains, all resistant to gentamicin, tobramycin, amikacin and netilmicin, were further examined for transferability and mechanisms of resistance. Aminoglycoside resistance was found to be transferable in most strains, and 13 R plasmids of 40–120 MDa molecular weight were detected. The enzymes detected consisted of three enzymes active against gentamicin [ANT(2), AAC(3)-I and AAC(3)-V]; three active against tobramycin [ANT(2), AAC(3)-V and AAC(6)-I]; two active against netilmicin [AAC(3)-V and AAC(6)-I]; and one active against amikacin [AAC(6)-I]. APH(3) and ANT (3), which modify neomycin and streptomycin plus spectinomycin respectively, were also found. Overall up to five aminoglycoside modifying enzymes were detected on the same R plasmid, AAC(6)-I plus ANT(2) being the most prevalent. The high incidence of multiresistance inEnterobacter cloacae and the fact that resistance is due to enzymatic inactivation of the antibiotics, indicate that in Greece this species might act as a gene pool for the spread of resistance to other bacteria of clinical relevance.