Frequent detection and characterization of hepatitis E virus variants in wild rats (Rattus rattus) in Indonesia

One hundred sixteen rats (Rattus rattus) captured in Indonesia from 2011 to 2012 were investigated for the prevalence of hepatitis E virus (HEV)-specific antibodies and HEV RNA. Using an ELISA based on HEV genotype 4 with an ad hoc cutoff value of 0.500, 18.1 % of the rats tested positive for anti-HEV IgG. By nested RT-PCR, 14.7 % of the rats had rat HEV RNA, and none were positive for HEV genotype 1-4. A high HEV prevalence among rats was associated with lower sanitary conditions in areas with a high population density. Sixteen of the 17 HEV isolates obtained from infected rats showed >93.0 % nucleotide sequence identity within the 840-nucleotide ORF1-ORF2 sequence and were most closely related to a Vietnamese strain (85.9-87.9 % identity), while the remaining isolate differed from known rat HEV strains by 18.8-23.3 % and may belong to a novel lineage of rat HEV. These results suggest a wide distribution of rat HEV with divergent genomes.     

Primary immunodeficiencies in cytosolic pattern-recognition receptor pathways: Toward host-directed treatment strategies

In the last decade, the paradigm of primary immunodeficiencies (PIDs) as rare recessive familial diseases that lead to broad, severe, and early-onset immunological defects has shifted toward collectively more common, but sporadic autosomal dominantly inherited isolated defects in the immune response. Patients with PIDs constitute a formidable area of research to study the genetics and the molecular mechanisms of complex immunological pathways. A significant subset of PIDs affect the innate immune response, which is a crucial initial host defense mechanism equipped with pattern-recognition receptors. These receptors recognize pathogen- and damage-associated molecular patterns in both the extracellular and intracellular space. In this review, we will focus on primary immunodeficiencies caused by genetic defects in cytosolic pattern-recognition receptor pathways. We discuss these PIDs organized according to their mutational mechanisms and consequences for the innate host response. The advanced understanding of these pathways obtained by the study of PIDs creates the opportunity for the development of new host-directed treatment strategies.     

Arylalkylamines are a novel class of positive allosteric modulators at GABA(B) receptors in rat neocortex

Using grease-gap recording from rat neocortical slices, the gamma-aminobutyric acid(B) (GABA(B)) receptor agonists baclofen (3-100 microM) and SKF 97541 (3-aminopropyl-methylphosphinic acid) (1-30 microM) elicited reversible and concentration-dependent hyperpolarizing responses, with EC(50) values of 10 and 3 microM, respectively. The hyperpolarizations were antagonised by the GABA(B) receptor antagonist Sch 50911 ((+)-(S)-5,5-dimethylmorpholinyl-2-acetic acid) (1, 5 and 10 microM). Fendiline (N-[3,3-diphenylpropyl)-alpha-methylbenzylamine) (5-50 microM) and its congeners, prenylamine (N-[3,3-diphenylpropyl)-alpha-methylphenylethylamine) (10-100 microM) and F551 (N-[3,3-diphenylpropyl)-alpha-methyl-3-methoxybenzylamine) (1-30 microM) reversibly enhanced hyperpolarizing responses to the agonists; such effects were reduced by Sch 50911. These arylalkylamines produced leftward shifts of the concentration-response curves, with a marked increase in the maximal hyperpolarization obtained, compared with the agonists alone, F551 being the most potent. These findings suggest that these arylalkylamines represent a new class of positive modulators of GABA(B) receptor-mediated function.     

Broadened ligand responsiveness of androgen receptor mutants obtained by random amino acid substitution of H874 and mutation hot spot T877 in prostate cancer

In a subset of endocrine therapy-resistant prostate cancers, amino acid substitutions H874Y, T877A and T877S, which broaden ligand specificity of the ligand binding domain (LBD) of the androgen receptor (AR), have been detected. To increase our knowledge of the role of amino acid substitutions at these specific positions in prostate cancer, codons 874 and 877 were subjected to random mutagenesis. AR mutants were screened in a yeast readout system for responsiveness to 5 alpha-dihydrotestosterone, progesterone and dehydroepiandrosterone. At position 874, only the histidine to tyrosine substitution could broaden AR ligand specificity. At position 877, 4 ligand specificity broadening substitutions were found: T877A, T877S, T877C and T877G. The latter 2 were not found in prostate cancer. The AR mutants were tested in mammalian (Hep3B) cells for responsiveness to 13 different ligands. All mutants displayed their own ligand specificity spectrum. Importantly, AR(H874Y) and AR(T877A) could be activated by cortisol. According to the 3-dimensional structure of the AR LBD, T877 interacts directly with the 17 beta-hydroxyl group of androgens. All amino acid substitutions identified at position 877 had smaller side chains than the threonine in the wild-type receptor, indicating that increased space in the ligand binding pocket is important in broadened ligand specificity. Because H874 does not interact directly with the ligand, its substitution by a tyrosine is expected to change the ligand binding pocket conformation indirectly. For T877C and T877G substitutions, 2-point mutations are required, and for H874Y, T877A and T877S substitutions, only a 1-point mutation is sufficient. This most likely explains that the latter 3 have been found in prostate cancer.     

A 10-year study of snowboard injuries in Lapland Sweden

Snowboard injuries in a Swedish ski area were evaluated from 1989 to 1999. All injured skiers (alpine, telemark, snowboarders) who sought medical attention at the local Medical Center within 48 h of the accident, were asked to answer an injury form. Physicians assessed and treated the injured skiers. There were a total of 1775 injured skiers; 568 injured snowboarders mean age 19 years. The female/male ratio was 34/66%, the injury rate 3/1000 skier days, three times higher than that of alpine skiers. The skill level of the injured snowboard riders improved during the period. The fall/run ratio of the beginners was higher (1.0) and their risk behavior lower (3.9 on visual analogue scale 1-10) in comparison to the advanced riders (0.4 and 6.6, respectively). Injuries were in 54% located to the upper extremity, 35% were wrist/lower arm injuries. Beginners had significantly higher frequency of lower arm/wrist injuries (46%), than average (32%) and advanced riders (20%). The most frequent single diagnosis was wrist/lower arm fracture (20%). Advanced riders tend to have more head/neck injuries than beginners, 17% vs. 13% (NS). Thus, with elevated skill level the injury pattern changed. For injury prevention, wrist guards and helmets are recommended for snowboard riders.