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Selected AbstractsCan hepatitis C virus prevalence be used as a measure of injection-related human immunodeficiency virus risk in populations of injecting drug users?ADDICTION, Issue 2 2010An ecological analysis ABSTRACT Background Human immunodeficiency virus (HIV) outbreaks occur among injecting drug users (IDUs), but where HIV is low insight is required into the future risk of increased transmission. The relationship between hepatitis C virus (HCV) and HIV prevalence among IDUs is explored to determine whether HCV prevalence could indicate HIV risk. Methods Systematic review of IDU HIV/HCV prevalence data and regression analysis using weighted prevalence estimates and time,series data. Results HIV/HCV prevalence estimates were obtained for 343 regions. In regions other than South America/sub-Saharan Africa (SAm/SSA), mean IDU HIV prevalence is likely to be negligible if HCV prevalence is <30% (95% confidence interval 22,38%) but increases progressively with HCV prevalence thereafter [linearly (, = 0.39 and R2 = 0.67) or in proportion to cubed HCV prevalence (, = 0.40 and R2 = 0.67)]. In SAm/SSA, limited data suggest that mean HIV prevalence is proportional to HCV prevalence (, = 0.84, R2 = 0.99), but will be much greater than in non-SAm/SSA settings with no threshold HCV prevalence that corresponds to low HIV risk. At low HCV prevalences (<50%), time,series data suggest that any change in HIV prevalence over time is likely to be much smaller (<25%) than the change in HCV prevalence over the same time-period, but that this difference diminishes at higher HCV prevalences. Conclusions HCV prevalence could be an indicator of HIV risk among IDUs. In most settings, reducing HCV prevalence below a threshold (30%) would reduce substantially any HIV risk, and could provide a target for HIV prevention. [source] Relationship between host diversity and parasite diversity: flea assemblages on small mammalsJOURNAL OF BIOGEOGRAPHY, Issue 11 2004Boris R. Krasnov Abstract Aim, We examined the relationship between host species richness and parasite species richness using simultaneously collected data on small mammals (Insectivora, Rodentia and Lagomorpha) and their flea parasites. Location, The study used previously published data on small mammals and their fleas from 37 different regions. All the world's main geographical regions other than Australasia and Wallacea were represented in the study, i.e. neotropical, nearctic, palaearctic, oriental and afrotropical realms. Methods, We controlled the data for the area sampled and sampling effort and then tested this relationship using both cross-region conventional analysis and the independent contrasts method (to control for the effects of biogeographic historical relationships among different regions). Brooks parsimony analysis was used to construct a region cladogram based on the presence/absence of a host species and host phylogeny. Results, Both cross-region and independent contrasts analyses showed a positive correlation between host species richness and flea species richness. Conventional cross-region regression under- or overestimated fleas species richness in the majority of regions. Main conclusions, When the regression derived by the independent contrasts method was mapped onto the original tip data space, points that deviated significantly from the regression originated from Kenya, Mississippi and southern California (lower than expected flea richness) and Chile, Idaho, south-western California and Kyrgyzstan (higher than expected flea richness). These deviations can be explained by the environmental mediation of host,flea relationships and by a degree of environmental variety in sampled areas. [source] Prevalence of Xerostomia in Population-based Samples: A Systematic ReviewJOURNAL OF PUBLIC HEALTH DENTISTRY, Issue 2 2006M.F. Orellana DDS Abstract The consequences of xerostomia on oral health have been studied for decades; however, the actual prevalence of this disorder on the general population remains controversial. The purpose of this systematic review was to determine the prevalence of xerostomia in population-based samples. Electronic databases were screened for relevant articles and reference lists of pertinent articles were also hand-searched. Thirteen articles meeting the final inclusion criteria were identified. Based on the definition of xerostomia used in this review, only publications including a subjective diagnosis of the disorder were included. All of the self-repotted diagnoses were achieved through a questionnaire either by mail, telephone, interview or self-administered by the patient. There was a variation across papers regarding number and content of the questions as well as guidelines for the diagnosis of xerostomia (i.e. answer yes to one or more than one question). The prevalence of xerostomia in the selected articles ranged from 0.9% to 64.8%. The majority of these studies were performed in Scandinavia. In 9 of the articles, the studied samples were 50 years and older. None of the studies evaluated the prevalence xerostomia among individuals younger than 18 years. Based on these observations, it can be concluded that there is a need for population-based studies on prevalence of xerostomia in regions other than Scandinavia. A standardized protocol to diagnose xerostomia needs to be developed. Patient-perceived treatment needs and impact on quality of life should be included to have a complete picture of public health implications of the disease. [source] Plasticity of language networks in patients with brain tumors: A positron emission tomography activation studyANNALS OF NEUROLOGY, Issue 5 2001Alexander Thiel MD We investigated plasticity of language networks exposed to slowly evolving brain damage. Single subject O-15-water language activation positron emission tomography studies were analyzed in 61 right-handed patients with brain tumors of the left hemisphere, and 12 normal controls. In controls, activations were found in left Brodmann's Area (BA)44 and BA45, superior posterior temporal gyrus bilaterally, and right cerebellum. Patients additionally activated left BA46, BA47, anterior insula, and left cerebellum. Superior temporal activation was less frequent, and activations in areas other than posterior temporal gyrus were found bilaterally. Frontolateral activations within the nondominant hemisphere were only seen in patients (63%) with frontal or posterior temporal lesions. Laterality indices of frontolateral cortex showed reversed language dominance in 18% of patients. Laterality indices of the cerebellum were negatively correlated with language performance. Two compensatory mechanisms in patients with slowly evolving brain lesions are described: An intrahemispheric mechanism with recruitment of left frontolateral regions other than classic language areas; and an interhemispheric compensatory mechanism with frontolateral activation in the nondominant hemisphere. The latter one was only found in patients with frontal or posterior temporal lesions, thus supporting the hypothesis that right frontolateral activations are a disinhibition phenomenon. [source] Comparative phylogeography of four Apodemus species (Mammalia: Rodentia) in the Asian Far East: evidence of Quaternary climatic changes in their genetic structureBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2010HÉLA SAKKA The phylogeography of four Apodemus species (Apodemus agrarius, Apodemus peninsulae, Apodemus latronum, and Apodemus draco) was studied in the Far East of Asia, based on sequences of the mitochondrial DNA cytochrome b gene. The results obtained show the existence of many different genetic lineages within the studied Apodemus species, suggesting the isolation and differentiation of populations in multiple refuge areas. Higher genetic diversities in some regions such as Yunnan, Sichuan (China), and eastern Russia suggest these areas are potential refuges for these species. The existence of such complex genetic structures could be linked to the presence of many biogeographic barriers (Himalaya Mountains, Tien-shan Mountains, Altai Mountains, Tibetan Plateau, Gobi desert, Yunnan Guizhou Plateau, Dzungaria basin, and others) in these regions, which were probably reinforced during the Quaternary climate changes. These barriers also played an important role concerning the low dispersal abilities of the two studied Apodemus species adapted to forest habitats (A. latronum and A. draco) with respect to colonizing regions other than China. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 797,821. [source] Childhood epidermolysis bullosa acquisita with autoantibodies against the noncollagenous 1 and 2 domains of type VII collagen: case report and review of the literatureBRITISH JOURNAL OF DERMATOLOGY, Issue 5 2006M. Mayuzumi Summary Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disease characterized by IgG autoantibodies to type VII collagen, a major component of anchoring fibrils. Most patients with EBA are adult and develop autoantibodies to the noncollagenous (NC) 1 domain of type VII collagen. We describe a 4-year-old Japanese boy presenting pruritic vesicles and tense blisters over his whole body. Immunofluorescence studies revealed linear IgG/C3 deposits along the dermal,epidermal junction of the patient's skin, and circulating IgG autoantibodies mapping to the dermal side of 1 M NaCl-split skin. By immunoblotting analysis using dermal extracts as a substrate, the patient's IgG antibodies labelled a 290-kDa protein corresponding to type VII collagen. Immunoblotting studies using recombinant proteins demonstrated that the patient's circulating autoantibodies recognized not only the NC1 but also the NC2 domain of type VII procollagen. Review of the previously reported cases and the present case suggested that patients with EBA with autoantibodies to regions other than the NC1 domain are all children younger than 10 years of age with clinical features of an inflammatory phenotype. [source] Identification of domains influencing assembly and ion channel properties in ,7 nicotinic receptor and 5-HT3 receptor subunit chimaerasBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2007V J Gee Background and purpose: Nicotinic acetylcholine receptors (nAChRs) and 5-hydroxytryptamine type 3 receptors (5-HT3Rs) are members of the superfamily of neurotransmitter-gated ion channels. Both contain five subunits which assemble to form either homomeric or heteromeric subunit complexes. With the aim of identifying the influence of subunit domains upon receptor assembly and function, a series of chimaeras have been constructed containing regions of the neuronal nAChR ,7 subunit and the 5-HT3 receptor 3A subunit. Experimental approach: A series of subunit chimaeras containing ,7 and 5-HT3A subunit domains have been constructed and expressed in cultured mammalian cells. Properties of the expressed receptors have been examined by means of radioligand binding, agonist-induced changes in intracellular calcium and patch-clamp electrophysiology. Key results: Subunit domains which influence properties such as rectification, desensitization and conductance have been identified. In addition, the influence of subunit domains upon subunit folding, receptor assembly and cell-surface expression has been identified. Co-expression studies with the nAChR-associated protein RIC-3 revealed that, in contrast to the potentiating effect of RIC-3 on ,7 nAChRs, RIC-3 caused reduced levels of cell-surface expression of some ,7/5-HT3A chimaeras. Conclusions and implications: Evidence has been obtained which demonstrates that subunit transmembrane domains are critical for efficient subunit folding and assembly. In addition, functional characterization of subunit chimaeras revealed that both extracellular and cytoplasmic domains exert a dramatic and significant influence upon single-channel conductance. These data support a role for regions other than hydrophobic transmembrane domains in determining ion channel properties. British Journal of Pharmacology (2007) 152, 501,512; doi:10.1038/sj.bjp.0707429; published online 27 August 2007 [source] | ||||||||||