Multiple Loci within the Major Histocompatibility Complex Confer Risk of Psoriasis

Psoriasis is a common inflammatory skin disease characterized by thickened scaly red plaques. Previously we have performed a genome-wide association study (GWAS) on psoriasis with 1,359 cases and 1,400 controls, which were genotyped for 447,249 SNPs. The most significant finding was for SNP rs12191877, which is in tight linkage disequilibrium with HLA-Cw*0602, the consensus risk allele for psoriasis. However, it is not known whether there are other psoriasis loci within the MHC in addition to HLA-C. In the present study, we searched for additional susceptibility loci within the human leukocyte antigen (HLA) region through in-depth analyses of the GWAS data; then, we followed up our findings in an independent Han Chinese 1,139 psoriasis cases and 1,132 controls. Using the phased CEPH dataset as a reference, we imputed the HLA-Cw*0602 in all samples with high accuracy. The association of the imputed HLA-Cw*0602 dosage with disease was much stronger than that of the most significantly associated SNP, rs12191877. Adjusting for HLA-Cw*0602, there were two remaining association signals: one demonstrated by rs2073048 (p = 2×10−6, OR = 0.66), located within c6orf10, a potential downstream effecter of TNF-alpha, and one indicated by rs13437088 (p = 9×10−6, OR = 1.3), located 30 kb centromeric of HLA-B and 16 kb telomeric of MICA. When HLA-Cw*0602, rs2073048, and rs13437088 were all included in a logistic regression model, each of them was significantly associated with disease (p = 3×10−47, 6×10−8, and 3×10−7, respectively). Both putative loci were also significantly associated in the Han Chinese samples after controlling for the imputed HLA-Cw*0602. A detailed analysis of HLA-B in both populations demonstrated that HLA-B*57 was associated with an increased risk of psoriasis and HLA-B*40 a decreased risk, independently of HLA-Cw*0602 and the C6orf10 locus, suggesting the potential pathogenic involvement of HLA-B. These results demonstrate that there are at least two additional loci within the MHC conferring risk of psoriasis

THE EFFECT OF WATER FLUORIDATION ON THE PRESENCE OF STR MUTANS IN DENTAL PLAQUE FLORA

134179418718

Association of HLA-A, -B, -C genes and TNF microsatellite polymorphism with psoriasis vulgaris: a study of genetic risk in Brazilian patients

This study investigated the genetic association of HLA class I genes and TNF-alpha microsatellites. HLA-A, -B, -C typing was carried out in 92 psoriasis vulgaris patients and 160 healthy individuals using a PCR-SSP method. 70 patients and 71 controls were typed for five microsatellite polymorphisms, TNFa-e. HLA-B*13 Cw*06, HLA-B*57 Cw*06 and HLA-B*39 Cw*12 haplotypes were found to be increased in patients with psoriasis type I when compared to controls, which could determine the susceptibility to development of psoriasis. TNFa4, TNFb1, TNFe1 and TNFa2 b1 c2 d4 el haplotypes showed a decreased frequency (p < 0.05) in psoriasis patients when compared to controls. HLA-B*13 allele and HLA-B * 13 Cw*06, TNFa11 b4 c1 d3 e3 haplotypes showed increased frequencies (p < 0.05) in patients with type II psoriasis, which suggests susceptibility to the onset of psoriasis. Our results detected polymorphisms of the HLA class I and microsatellite TNF locus which could be markers of genetic predisposition to the disease.16552352

Dynamics of feeding and defecation in Triatoma vitticeps (Stal, 1859) (Hemiptera, Reduviidae, Triatominae) and its potential in the transmission of Trypanosoma cruzi

Adults of Triatoma vitticeps infected by flagellates similar to Trypanosoma cruzi are frequently captured by the inhabitants of rural areas in the Brazilian state of Espírito Santo. The dynamics of feeding and defecation were observed in three groups of adult triatomines, consisting of sylvatic T. vitticeps and laboratory-reared specimens of this species and T. infestans. Triatomines were observed from the moment they were presented with an immobilized chicken as a bloodmeal source until 240 min after feeding had ended. Mean times between the end of feeding and defecation for T. infestans, wild T. vitticeps and laboratory-reared specimens of the latter species were 1.2, 21.1, and 64 min respectively. All T. infestans defecated within 10 min of feeding, while only 29.9 of wild and 52.8% laboratory-reared specimens of T. vitticeps did so within this period. These results may explain the low efficiency of T. vitticeps in T. cruzi transmission to man. The shorter time between feeding and defecation in laboratory-reared T. vitticeps may indicate a change in behaviour of this species as a result of adaptation to an artificial environment

Phlebotomine sand flies (Diptera, Psychodidae) in an American tegumentary leishmaniasis transmission area in northern Espírito Santo State, Brazil Fauna de flebotomíneos (Diptera, Psychodidae) em área de transmissão de leishmaniose tegumentar americana no norte do Estado do Espírito Santo, Brasil

American tegumentary leishmaniasis is endemic to the Espírito Santo State, Brazil, where it is widely distributed. The composition of the phlebotomine sand fly fauna in an American tegumentary leishmaniasis focus was determined by monthly sampling, using Shannon light traps in an Atlantic Forest reserve and adjacent habitat that had been modified by human activity. Seasonal fluctuations in numbers of the most abundant species were also monitored from June 2004 to May 2006. Of the 6,176 specimens collected, 47.4% were captured in the forest and 52.6% in the disturbed habitat. Although Lutzomyia davisi (60.8%) predominated in specimens from the forest, those captured near human dwellings consisted almost entirely of Lu. choti (72%) and Lu. intermedia (24.3%). All three species occurred throughout the year. Based on our findings, Lu. intermedia probably acts as the principal domestic Leishmania vector in the study area.<br>A leishmaniose tegumentar americana é endêmica e amplamente distribuída no Estado do Espírito Santo, Brasil. Com o objetivo de avaliar a composição da fauna de flebotomíneos e verificar a flutuação sazonal, foram realizadas capturas mensais com armadilhas Shannon modificadas em reserva florestal de Mata Atlântica (Reserva Biológica de Sooretama) e ambiente antrópico adjacente, no período de junho de 2004 a maio de 2006. Foram capturados 6.176 espécimes, dos quais 47,4% ocorreram no ambiente florestal e 52,6%, no ambiente antrópico. Lutzomyia davisi (60,8%) predominou no ambiente florestal e Lu. choti (72%) seguida de Lu. intermedia (24,3%) predominaram no ambiente antrópico. As três espécies ocorreram ao longo de todo o ano. Os dados indicam que Lu. intermedia provavelmente atue como principal vetor domiciliar de Leishmania na área de estudo