A biomarker for tegumentary and visceral leishmaniasis based on a recombinant Leishmania hypothetical protein

The measures for leishmaniasis control include the precise diagnosis of disease. However, although several recombinant antigens have been tested with this biotechnological purpose, no effective product exists, which could detects patients with the active disease, as well as differentiates them from cured and treated patients. In this study, a conserved Leishmania hypothetical protein, which was identified in Leishmania infantum parasites, but evaluated to presents high homology in the amino acid sequences between distinct parasite species, was evaluated for the diagnosis of tegumentary and visceral leishmaniasis. In addition, PBMCs collected from treated and untreated mucosal leishmaniasis (ML) and visceral leishmaniasis (VL) patients, as well as in healthy subjects living in endemic region of disease, were in vitro stimulated, when IFN-γ, IL-4 and IL-10 levels were evaluated in the cell supernatant. Regarding the serological analyses, ELISA experiments using the recombinant protein (rLiHyL) and a human serological panel revealed high sensitivity and specificity values to detect both diseases, while control antigens showed worst results. Regarding the cellular response, results showed that rLiHyL-stimulated cells produced higher IFN-γ and lower IL-4 and IL-10 levels in the supernatants. Also, the anti-protein antibody production was evaluated in these patients, and data showed higher IgG2 and lower IgG1 levels found in the treated patients and healthy controls, demonstrating the stimulation of a Th1-type response induced by the rLiHyL protein. In conclusion, this hypothetical protein can be considered as antigenic in TL and VL, as well as a vaccine candidate to be tested in future studies to protect against disease.     

Detection of regulatory T cell phenotypic markers and cytokines in patients with human papillomavirus infection

Infection with human papillomavirus (HPV) is the main cause of cervical cancer. Viral persistence is considered the main risk factor for neoplastic progression and evidence suggests that regulatory T cells (Treg) play an important role in the failure of viral elimination. The aim of this study was to detect phenotypic markers of Treg and cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β, in the cervical microenvironment of HPV-infected patients. One hundred and one samples of uterine cervix embedded in paraffin were analyzed. We used immunohistochemistry to examine the coexpression of the CD25/FOXP3 and CD4/TGF-β markers, and the expression of GITR and IL-10 in cells present in the cervical stroma. We detected a microenvironment composed of high proportions of CD25⁺FOXP3⁺, CD4⁺TGFβ⁺, IL-10⁺, and GITR⁺ cells in samples with high viral loads and severe lesions of HPV-infected patients. The abundance of these markers, indicative of the presence of Treg cells and immunosuppressive cytokines, was significantly associated with severe lesions and elevated viral loads in the examined samples. These results suggest that Treg cells may be involved in maintaining a microenvironment favorable for viral persistence and neoplastic progression. Our findings support those of previous studies that suggested that these markers could be used to predict HPV persistence and neoplastic progression, and as potential targets for immune response modulation.     

Hepatitis C virus genotypes in hemodialysis patients in Angola

To our knowledge, there are no published data on hepatitis C virus (HCV) genotypes in Angola. This study aimed at assessing the distribution of HCV genotypes in seropositive hemodialysis patients in Luanda. Among 51 HCV-positive subjects included, viremia was detected in 27 (53%). HCV genotyping was performed by bidirectional sequencing of the 5'-untranslated region by the Sanger method. HCV genotype 4 was largely predominant (20 cases; 74%), followed by genotypes 1b (5 cases; 18.5%), 1a and 2 (one case each; 3.7%). These results suggest that the distribution of HCV genotypes in Angola is similar to that reported from other Central African countries.     

Eryptosis of non-parasitized erythrocytes is related to anemia in Plasmodium berghei low parasitema malaria of Wistar rats

Parasitology Research - It is known that premature elimination of non-parasitized RBCs (nRBCs) plays an important role in the pathogenesis of malarial anemia, in which suicidal death process...     

Infection patterns,clinical significance,and genetic characteristics of Enterocytozoon bieneusi and Giardia duodenalis in dairy cattle in Jiangsu,China

The infection patterns and clinical significance of Enterocytozoon bieneusi and Giardia duodenalis in dairy cattle remain poorly investigated despite their common occurrence. Data on the genetic diversity are also needed to understand the transmission and human-infective potential of the two pathogens. In this study, fecal specimens from 1366 dairy cattle on a large farm were examined for the presence and genotype distribution of E. bieneusi and G. duodenalis by PCR and DNA sequencing. The overall infection rates of E. bieneusi and G. duodenalis were 13.0% and 20.6%, respectively. Pre-weaned calves had significantly higher infection rates of both pathogens than post-weaned and adult cattle (P < 0.001), with peak occurrence of the pathogens in animals of 7–12 weeks. In both pre- and post-weaned calves, animals with diarrhea were 2.1–3.0 times more likely to be infected with either pathogen than those without diarrhea (P < 0.01). The E. bieneusi identified belonged to five genotypes, including J (n = 138), I (n = 21), BEB4 (n = 10), Type IV (n = 1), and a novel genotype CHC17 (n = 1). Genotype J was the dominant one in all age groups, whereas genotype I was only identified in calves of 6–11 weeks. Genotyping of G. duodenalis at three genetic loci identified assemblage E (n = 278), assemblage A (n = 2), and concurrence of the two (n = 1). Altogether, 13, 7 and 10 subtypes of assemblage E were detected at the bg, gdh, and tpi loci, respectively, forming 65 multilocus genotypes. The formation of two major clusters of MLGs in eBURST analysis indicated that intra-assemblage genetic recombination of two dominant MLGs could have led to the high genetic heterogeneity within assemblage E on a single farm. Results of this study provide much needed data on the pathogenicity of E. bieneusi and G. duodenalis in pre- and post-weaned calves. The clinical significance of the two pathogens in dairy cattle warrants further investigations.

     

两款糖化血红蛋白床旁分析仪的正确性评价

目的借助二级参考测量程序(SRMP),探讨两款床旁(point-of-care testing,POCT)糖化血红蛋白(HbA1c)分析仪的正确性。方法依据美国临床和实验室标准化协会(CLSI)Ep9-A2选取40份临床EDTA抗凝静脉全血样本,用比对的方式,分别评价两款POCT HbA1c分析仪与SRMP间的偏倚。结果POCT-1和POCT-2相关方程分别为,Y=1.0424X-0.3144和Y=1.0054X-0.2242相关系数(r)分别为0.9959和0.9469。临床各诊断切点处,偏倚小于美国国家糖化血红蛋白标准化计划(NGSP)和美国病理家协会(CAP)的要求(±6%)。结论两款POCTHbA1c分析仪与溯源到IFCC参考方法的SRMP比对具有良好的正确性,可以满足临床使用。     

北京地区尘螨过敏患者特异性IgE水平分析

目的了解北京地区不同年龄、性别尘螨过敏患者对尘螨敏感性差异。方法本研究采用回顾性横断面研究,纳入我科2016年8月至2017年7月因过敏性疾病就诊、户尘螨或粉尘螨至少一项sIgE阳性患者318例。分别比较户尘螨及粉尘螨sIgE水平差异以及不同性别、年龄患者尘螨sIgE水平差异。结果两种尘螨sIgE水平差异无统计学意义(P=0.336)。男性患者血清特异性IgE(sIgE)平均水平明显高于女性患者(P=0.009),其中男性特重度过敏患者所占比例明显高于女性(P<0.001),但女性中度过敏患者所占比例明显高于男性(P=0.01)。年龄与抗体水平呈明显负相关(R=-0.217,P<0.001)。婴幼儿、儿童、少年组中特重度过敏患者所占比例最高,分别为各自组的42.3%、31.5%、38.1%。儿童及少年特重度过敏患者中,男性患者所占比例明显高于女性(P=0.04,P=0.01)。结论户尘螨及粉尘螨过敏常同时存在,且过敏严重程度相当。尘螨过敏原敏感程度与年龄及性别明确相关。     

A unique telomere DNA expansion phenotype in human retinal rod photoreceptors associated with aging and disease

We have identified a discrete, focal telomere DNA expansion phenotype in the photoreceptor cell layer of normal, non‐neoplastic human retinas. This phenotype is similar to that observed in a subset of human cancers, including a large fraction of tumors of the central nervous system, which maintain their telomeres via the non‐telomerase‐mediated alternative lengthening of telomeres (ALT) mechanism. We observed that these large, ultra‐bright telomere DNA foci are restricted to the rod photoreceptors and are not observed in other cell types. Additionally, focus‐positive rod cells are dispersed homogeneously throughout the posterior retinal photoreceptor cell layer and appear to be human‐specific. We examined 108 normal human retinas obtained at autopsy from a wide range of ages. These large, ultra‐bright telomere DNA foci were not observed in infants before 6 months of age; however, the prevalence of focus‐positive rod cells dramatically increased throughout life. To investigate associations between this phenotype and retinal pathology, we assessed adult glaucoma (N = 29) and diabetic retinopathy (N = 38) cases. Focus‐positive rod cells were prominent in these diseases. When compared to the normal group, after adjusting for age, logistic regression modeling revealed significantly increased odds of falling in the high category of focus‐positive rod cells for glaucoma and diabetic retinopathy. In summary, we have identified a dramatic telomere alteration associated with aging and diseases affecting the retina.