Helicobacter pylori in dental plaque and stomach of patients from Northern Brazil

AIM: To establish whether virulence factor genes vacA and cagA are present in Helicobacter pylori (H. pylori) retrieved from gastric mucosa and dental plaque in pa-tients with dyspepsia. METHODS: Cumulative dental plaque specimens and gastric biopsies were submitted to histological exami-nation, rapid urease test and polymerase chain reac-tion (PCR) assays to detect the presence of cagA and vacA polymorphisms.RESULTS: Detection of H. pylori from dental plaque and gastric biopsy samples was greater by PCR com-pared to histological examination and the rapid ure-ase test. DNA from H. pylori was detected in 96% of gastric mucosa samples and in 72% of dental plaque samples. Sixty-three (89%) of 71 dental plaque sam-ples that were H. pylori-positive also exhibited identical vacA and cagA genotypes in gastric mucosa. The most common genotype was vacAs1bm1 and cagA positive, either in dental plaque or gastric mucosa. These viru-lent H. pylori isolates were involved in the severity of clinical outcome.CONCLUSION: These pathogenic strains were found simultaneously in dental plaque and gastric mucosa, which suggests that gastric infection is correlated with the presence of H. pylori in the mouth.

High tacrolimus intra-patient variability is associated with graft rejection,and de novo donor-specific antibodies occurrence after liver transplantation

AIM To investigate the role of tacrolimus intra-patient variability(IPV) in adult liver-transplant recipients.METHODS We retrospectively assessed tacrolimus variability in a cohort of liver-transplant recipients and analyzed its effect on the occurrence of graft rejection and de novo donor-specific antibodies(dn DSAs), as well as graft survival during the first 2 years posttransplantation. Between 02/08 and 06/2015, 116 patients that received tacrolimus plus mycophenolate mofetil(with or without steroids) were included. RESULTS Twenty-two patients(18.5%) experienced at least one acute-rejection episode(BPAR). Predictive factors for a BPAR were a tacrolimus IPV of > 35% [OR = 3.07 95%CI(1.14-8.24), P = 0.03] or > 40% [OR = 4.16(1.38-12.50), P = 0.01), and a tacrolimus trough level of < 5 ng/mL [OR=3.68(1.3-10.4), P =0.014]. Thirteen patients(11.2%) developed at least one dn DSA during the follow-up. Tacrolimus IPV [coded as a continuous variable: OR = 1.1, 95%CI(1.0-1.12), P = 0.006] of > 35% [OR = 4.83, 95%CI(1.39-16.72), P = 0.01] and > 40% [OR = 9.73, 95%CI(2.65-35.76), P = 0.001] were identified as predictors to detect dn DSAs. IPV did not impact on patient-or graft-survival rates during the follow-up. CONCLUSION Tacrolimus-IPV could be a useful tool to identify patients with a greater risk of graft rejection and of developing a de novo DSA after liver

Prediction of delayed graft function using different scoring algorithms: A single-center experience

AIM To compare the performance of 3 published delayed graftfunction(DGF) calculators that compute the theoretical risk of DGF for each patient.METHODS This single-center,retrospective study included 247 consecutive kidney transplants from a deceased donor.These kidney transplantations were performed at our institution between January 2003 and December 2012.We compared the occurrence of observed DGF in our cohort with the predicted DGF according to three different published calculators. The accuracy of the calculators was evaluated by means of the c-index(receiver operating characteristic curve).RESULTS DGF occurred in 15.3% of the transplants under study.The c index of the Irish calculator provided an area under the curve(AUC) of 0.69 indicating an acceptable level of prediction,in contrast to the poor performance of the Jeldres nomogram(AUC = 0.54) and the Chapal nomogram(AUC = 0.51). With the Irish algorithm the predicted DGF risk and the observed DGF probabilities were close. The mean calculated DGF risk was significantly different between DGF-positive and DGF-negative subjects(P < 0.0001). However,at the level of the individual patient the calculated risk of DGF overlapped very widely with ranges from 10% to 51% for recipients with DGF and from 4% to 56% for those without DGF.The sensitivity,specificity and positive predictive value of a calculated DGF risk ≥ 30% with the Irish nomogram were 32%,91% and 38%. CONCLUSION Predictive models for DGF after kidney transplantation are performant in the population in which they were derived,but less so in external validations.

Cost effective filamentous phage based immunization nanoparticles displaying a full-length hepatitis B virus surface antigen

Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface antigen (HBsAg) is a key target molecule in developing vaccines and diagnostic systems. To date, although HBsAg has been expressed in bacteria, yeasts and mammalian cells, there are still limitations in the existing ones, which leave the necessity for searching new HBsAg production methods. In this study, a simple phage display-based method was developed to produce the purified full-length HBsAg molecules for further immunization studies. For this purpose, the HBsAg coding gene was cloned into a pCANTAB5E phagemid vector and expressed on the surface of M13 filamentous phages. The HBsAg-expressing phage nanosystem was then used as immunization agent in BALB/cJ mice. The ELISA results for sera obtained from mice immunized with HBsAg-displaying phage particles revealed an immune response against HBsAg. These results demonstrate the potential use of a full-length antigen to be displayed on phages as cost effective adjuvant-free immunization agents as an alternative to the highly purified and more expensive antigens conjugated with carrier molecules.

Human leukocyte antigens-immunogenetics of neuromyelitis optica or Devic’s disease and the impact on the immunopathogenesis,diagnosis and treatment:a critical review

Neuromyelitis optica(NMO)is an autoimmune demyelinating disorder,predominantly characterized by severe optic neuritis,transverse myelitis and the high level of antibodies against aquaporin-4(AQP4)or NMO-immunoglobulin G(IgG).Researches trying to correlate NMO with specific human leukocyte antigen(HLA)alleles took place in a limited extend in the last few years.Nevertheless,it has become clear that HLAs play a crucial role in the genetic risk of NMO,in the understanding of its pathogenesis and the differential diagnosis mainly from multiple sclerosis(MS),and also from other demyelinating diseases.In this study,we retrieved all the available data in the MEDLINE concerning the distribution of HLA frequencies in NMO and NMO-spectrum diseases,in all available ethnic groups,and compared them with those of MS.The results suggest that,the well-established HLA-DRB1*15:01 allele,associated with MS,plays rather a protective role for NMO.HLA-DRB1*03 allele is highly frequent in the NMO-IgG positive Caucasian patients,while HLA-DPB1*05:01 is the predominant allele in Japanese patients.The HLA-genotype and anti-AQP4 presence are the common immunological components in cases of comorbidity of NMO and other autoimmune diseases.The authors aim to summarize in the critical review the results of these researches worldwide,create a workable table including all this information for an easier reading approach and highlight the importance of these results in therapeutic decision making,using the HLA profile as biomarker in patients’stratification.

Albumosomes formed by cytoplasmic pre-folding albumin maintain mitochondrial homeostasis and inhibit nonalcoholic fatty liver disease

Hepatic mitochondrial dysfunction contributes to the progression of nonalcoholic fatty liver disease(NAFLD).However,the factors that maintain mitochondrial homeostasis,especially in hepatocytes,are largely unknown.Hepatocytes synthesize various high-level plasma proteins,among which albumin is most abundant.In this study,we found that pre-folding albumin in the cytoplasm is completely different from folded albumin in the serum.

Immunogenetic factors driving formation of ultralong VH CDR3 in Bos taurus antibodies

The antibody repertoire of Bos taurus is characterized by a subset of variable heavy(VH)chain regions with ultralong third complementarity determining regions(CDR3)which,compared to other species,can provide a potent response to challenging antigens like HIV env.These unusual CDR3 can range to over seventy highly diverse amino acids in length and form uniqueβ-ribbon‘stalk’and disulfide bonded‘knob’structures,far from the typical antigen binding site.The genetic components and processes for forming these unusual cattle antibody VH CDR3 are not well understood.Here we analyze sequences of Bos taurus antibody VH domains and find that the subset with ultralong CDR3 exclusively uses a single variable gene,IGHV1-7(VHBUL)rearranged to the longest diversity gene,IGHD8-2.An eight nucleotide duplication at the 3′end of IGHV1-7 encodes a longer V-region producing an extended Fβ-strand that contributes to the stalk in a rearranged CDR3.A low amino acid variability was observed in CDR1 and CDR2,suggesting that antigen binding for this subset most likely only depends on the CDR3.Importantly a novel,potentially AID mediated,deletional diversification mechanism of the B.taurus VH ultralong CDR3 knob was discovered,in which interior codons of the IGHD8-2 region are removed while maintaining integral structural components of the knob and descending strand of the stalk in place.These deletions serve to further diversify cysteine positions,and thus disulfide bonded loops.Hence,both germline and somatic genetic factors and processes appear to be involved in diversification of this structurally unusual cattle VH ultralong CDR3 repertoire.

Diabetes:特殊免疫细胞亚群或促进1型糖尿病发展

发表在国际杂志Diabetes上的一项最新研究中，来自东芬兰大学的研究人员通过研究发现，最近描述的一种T细胞亚群或许在1型糖尿病的发生上扮演着关键性的中枢角色；这种名为滤泡T辅助细胞的T细胞亚群在1型糖尿病开始阶段时水平处于增加之中，而且这种现象和疾病相关的常见自身抗体的存在直接相关。

Concerning the KIR gene frequencies reported by Dr Araujo et al.

Killer cell immtmoglobulin-like recep- tors （KIRs） are transmembraneglycoproteins expressed by natural killer cells and subsets of T cells. The KIR genes are polymorphic, highly homolo- gous and found in a duster on chromo- some 19q13.4 within the 1 Mb leukocyte receptor complex. The gene content of the KIR gene cluster varies among haplotypes, although several frame- work genes are found in all haplotypes （including KIR3DL3, KIR3DP1, KIR2DL4 and KIR3DL2）. In spite of the extended diversity of the KIR genomic region, these four framework loci are nearly ubiquitous in the population, and the pseudogene （KIR3DPI） is not expressed.1