Comparative genomics studies on the stk gene family in vertebrates: From the bighead carp (Hypophthalmichthys nobilis) genome.

The mammalian sterile 20-like (MST) family belongs to the serine/threonine protein kinase (STK) superfamily and participates in a variety of biological processes, such as cell apoptosis, polarity, migration, immune regulation, inflammatory responses, and cancer. In the economically important bighead carp (Hypophthalmichthys nobilis), the STK gene family and immune-related biological functions may be helpful in increasing its economic yield. However, the comprehensive role of STKs in the bighead carp remains unclear. In this study, the five stk sequences from the bighead carp were divided into two classes: stk3/4 and stk24/25/26. Gene structure and motif prediction analyses confirmed that stk is conserved in the bighead carp. Compared to 26 other vertebrate species, teleosts (including bighead carp) possess more stk members because of teleost-specific whole-genome duplication. Synteny analysis revealed that stk3, stk24, stk25, and stk26 have been relatively conserved in bighead carp during evolution. Meanwhile, stk4 was lost in most Cyprinid species, including bighead carp, during evolution. RNA-seq data revealed that STK expression was associated with various pathogens, and the expression of these STKs (Hnstk3, Hnstk24a, Hnstk24b, Hnstk25, and Hnstk26) was different in seven tissues of bighead carp. In addition, we showed that STK expression levels were dramatically altered in the head kidney and that stk24 was involved in defense against Aeromonas hydrophila. This study provides a molecular basis for the analysis of stk function in bighead carp, and can be used as a reference for further phylogenomics.

High prevalence of vitamin D deficiency in Shenzhen pregnant women.

BACKGROUND: Vitamin D deficiency is a public health problem worldwide. Vitamin D deficiency in pregnant women often leads to negative clinical consequence and has been distributed differently in certain latitudes. Here, we aimed to determine the prevalence of vitamin D deficiency in pregnant women in Shenzhen City and investigate the influencing factors. METHODS: A total of 27,166 healthy pregnant women, undergoing prenatal examinations in our hospital between July 2014 and December 2018, were enrolled in our study. Maternal characteristics, including the duration of pregnancy, age and enrollment time, were recorded. The concentrations of serum 25(OH)D in the blood samples were detected by immunochemistry assays. RESULTS: For the total study population, the median serum 25(OH)D concentration was 23.36 [17.98-29.51] ng/mL, and 34.3% and 42.4% of the participants exhibited vitamin D deficiency (serum 25(OH) D < 20 ng/mL) and insufficiency (serum 25(OH)D 21-29 ng/mL), respectively. Vitamin D deficiency decreased with gestation (37.83%, 33.8%, and 29.3% for the first trimester, second trimester and third trimester, respectively, p < .001) and decreased by age (36.03%, 35.20%, 31.86% and 29.83%, for the age groups 18-24, 25-29, 30-34 and 35-46 years, respectively, p < .001). This prevalence had conspicuous seasonality (winter vs. autumn, OR 3.69, 95% CI: 3.42-3.99, p < .001). Temperature was positively associated with women's serum 25(OH)D level (r = 0.48, p < .001). CONCLUSIONS: Overall, we demonstrated that vitamin D deficiency in pregnant women in Shenzhen was common and was affected by gestation, age and season/temperature.

The Associations of Genital Mycoplasmas with Female Infertility and Adverse Pregnancy Outcomes: a Systematic Review and Meta-analysis.

The roles of genital mycoplasmas including Mycoplasma genitalium (M. genitalium), Mycoplasma hominis (M. hominis), Ureaplasma urealyticum (U. urealyticum), and Ureaplasma parvum (U. parvum) in reproductive diseases are equivocal. To investigate whether genital mycoplasmas are risk factors of female infertility and adverse pregnancy outcomes, we performed a systematic review and meta-analysis. Electronic databases were searched for related studies. A random-effects model or fixed-effects model was employed to generate forest plots. Pooled odd ratios (ORs) with 95% confidence intervals (CIs) were applied to measure the strength of associations. Meanwhile, heterogeneity was evaluated by H statistic and I2 statistic, and publication bias was explored by funnel plots based on Egger's test and Begg's test. The search yielded 2054 relevant records, and 35 articles were ultimately included for meta-analysis. M. genitalium was a significant risk factor for female infertility (OR, 13.03 [95% CI, 3.46-48.98]) and preterm birth (PTB) (OR, 1.81 [95% CI, 1.17-2.80]), but not for spontaneous abortion (SA) (OR, 0.58 [95% CI, 0.25-1.35]). M. hominis can significantly increase the potential risk of female infertility (OR, 1.56 [95% CI, 1.02-2.38]), SA (OR, 9.14 [95% CI, 4.14-20.18]), stillbirth (OR, 3.98 [95% CI, 1.39-11.36]), and premature rupture of membranes (PROM) (OR, 1.79 [95% CI, 1.26-2.55]), but was not associated with PTB (OR, 1.29 [95% CI, 0.78-2.15]). U. urealyticum had no significant risk effect on female infertility (OR, 0.68 [95% CI, 0.42-1.11]). Coinfections of M. hominis and Ureaplasma were significantly associated with female infertility, SA, and stillbirth, but not with PROM. On the basis of current evidences, this meta-analysis supports that M. genitalium is a risk factor for female infertility and PTB; M. hominis is a potential risk factor for female infertility, SA, stillbirth, and PROM; U. urealyticum has no significant association with female infertility; and the relationship of U. parvum with female infertility and adverse pregnancy outcomes needs to be paid more attention to and remains to be further revealed.

Corrigendum: Identification of Novel Laminin- and Fibronectin-Binding Proteins by Far-Western Blot: Capturing the Adhesins of Streptococcus suis Type 2.

[This corrects the article DOI: 10.3389/fcimb.2015.00082.].

Rapid and accurate diagnosis of Chlamydia trachomatis in the urogenital tract by a dual-gene multiplex qPCR method.

Introduction. Chlamydia trachomatis (C. trachomatis, CT) is an obligatory intracellular bacterium that causes urogenital tract infections and leads to severe reproductive consequences. Therefore, a rapid and accurate detection method with high sensitivity and specificity is an urgent requirement for the routine diagnosis of C. trachomatis infections.Aim. In this study, we aimed to develop a multiplex quantitative real-time PCR (qPCR) assay based on two target regions for accurate detection of C. trachomatis in urogenital tract infections.Methodology. Primers and probes based on the conserved regions of the cryptic plasmid and 23S rRNA gene were designed. Then, two qPCR assays were established to screen for the optimal probe and primers for each of the two target regions. Subsequently, the multiplex qPCR method was developed and optimized. For the diagnostic efficiency evaluation, 1284 urogenital specimens were tested by the newly developed multiplex qPCR method, an immunological assay and a singleplex qPCR assay widely used in hospitals.Results. The multiplex qPCR method could amplify both target regions in the range of 1.0×102-1.0×108 copies ml-1 with a strong linear relationship, and lower limits of detection (LODs) for both targets reached 2 copies PCR-1. For the multiplex qPCR method, the diagnostic sensitivity and specificity was 100.0 % (134/134) and 99.3 % (1142/1150), respectively. For the singleplex qPCR assay, the diagnostic sensitivity and specificity was 88.8 % (119/134) and 100.0 % (1150/1150), respectively. For the immunological assay, the diagnostic sensitivity and specificity was 47.0 % (63/134) and 100.0 % (1150/1150), respectively.Conclusion. In this study, a multiplex qPCR assay with high sensitivity and specificity for rapid (≤2.0 h) and accurate diagnosis of C. trachomatis was developed. The qPCR assay has the potential to be used as a routine diagnostic method in clinical microbiology laboratories.

Rapid diagnosis of human adenovirus B, C and E in the respiratory tract using multiplex quantitative polymerase chain reaction.

Human adenovirus (HAdV) is increasingly recognized as a major cause of human respiratory tract viral infections. Its outbreaks and epidemics in various populations resulted in considerable morbidity and mortality. Therefore, a rapid and specific assay for HAdV in clinical samples is of crucial importance to diagnosing HAdV infections. The present study aimed to develop and evaluate a multiplex quantitative polymerase chain reaction (qPCR) assay for the rapid detection and accurate quantification of HAdV B, C and E. The lower limit of detection for this assay was two genomic copies per reaction, and quantitative linearity ranged from 2 to 2x106 copies per reaction of the input viral DNA. Furthermore, 3,160 throat swab samples that tested HAdV negative by the immunofluorescence assay were collected and retested using the multiplex qPCR assay. The results showed that 2,906 samples were HAdV negative and the other 254 samples were HAdV positive. The HAdV species identified included B (184 samples), C (51 samples), and E (39 samples). Among the three HAdV species, HAdV B and E were detected from 8 samples, and HAdV C and E were detected from other 12 samples. The overall results demonstrated that the sensitivity and specificity of the proposed assay were 100% (254/254) and 99.6% (2894/2906), respectively. From the perspective of routine clinical diagnosis, this assay represented a rapid (≤1.5 h) and economic strategy, and had the potential to be used for the rapid and accurate diagnosis of human respiratory infections caused by HAdV B, C and E.

Anisotropic surface chemistry properties and adsorption behavior of silicate mineral crystals.

Anisotropic surface properties of minerals play an important role in a variety of fields. With a focus on the two most intensively investigated silicate minerals (i.e., phyllosilicate minerals and pegmatite aluminosilicate minerals), this review highlights the research on their anisotropic surface properties based on their crystal structures. Four surface features comprise the anisotropic surface chemistry of minerals: broken bonds, energy, wettability, and charge. Analysis of surface broken bond and energy anisotropy helps to explain the cleavage and growth properties of mineral crystals, and understanding surface wettability and charge anisotropy is critical to the analysis of minerals' solution behavior, such as their flotation performance and rheological properties. In a specific reaction, the anisotropic surface properties of minerals are reflected in the adsorption strengths of reagents on different mineral surfaces. Combined with the knowledge of mineral crushing and grinding, a thorough understanding of the anisotropic surface chemistry properties and the anisotropic adsorption behavior of minerals will lead to the development of effective relational models comprising their crystal structure, surface chemistry properties, and targeted reagent adsorption. Overall, such a comprehensive approach is expected to firmly establish the connection between selective cleavage of mineral crystals for desired surfaces and designing novel reagents selectively adsorbed on the mineral surfaces. As tools to characterize the anisotropic surface chemistry properties of minerals, DLVO theory, atomic force microscopy (AFM), and molecular dynamics (MD) simulations are also reviewed.

The non-conserved region of MRP is involved in the virulence of Streptococcus suis serotype 2.

Muramidase-released protein (MRP) of Streptococcus suis serotype 2 (SS2) is an important epidemic virulence marker with an unclear role in bacterial infection. To investigate the biologic functions of MRP, 3 mutants named Δmrp, Δmrp domain 1 (Δmrp-d1), and Δmrp domain 2 (Δmrp-d2) were constructed to assess the phenotypic changes between the parental strain and the mutant strains. The results indicated that MRP domain 1 (MRP-D1, the non-conserved region of MRP from a virulent strain, a.a. 242-596) played a critical role in adherence of SS2 to host cells, compared with MRP domain 1* (MRP-D1*, the non-conserved region of MRP from a low virulent strain, a.a. 239-598) or MRP domain 2 (MRP-D2, the conserved region of MRP, a.a. 848-1222). We found that MRP-D1 but not MRP-D2, could bind specifically to fibronectin (FN), factor H (FH), fibrinogen (FG), and immunoglobulin G (IgG). Additionally, we confirmed that mrp-d1 mutation significantly inhibited bacteremia and brain invasion in a mouse infection model. The mrp-d1 mutation also attenuated the intracellular survival of SS2 in RAW246.7 macrophages, shortened the growth ability in pig blood and decreased the virulence of SS2 in BALB/c mice. Furthermore, antiserum against MRP-D1 was found to dramatically impede SS2 survival in pig blood. Finally, immunization with recombinant MRP-D1 efficiently enhanced murine viability after SS2 challenge, indicating its potential use in vaccination strategies. Collectively, these results indicated that MRP-D1 is involved in SS2 virulence and eloquently demonstrate the function of MRP in pathogenesis of infection.

Factor H specifically capture novel Factor H-binding proteins of Streptococcus suis and contribute to the virulence of the bacteria.

Factor H (FH), a regulatory protein of the complement system, can bind specifically to factor H-binding proteins (FHBPs) of Streptococcus suis serotype 2 (SS2), which contribute to evasion of host innate immune defenses. In the present study, we aimed to identify novel FHBPs and characterize the biological functions of FH in SS2 pathogenesis. Here, a method that combined proteomics and Far-western blotting was developed to identify the surface FHBPs of SS2. With this method, fourteen potential novel FHBPs were identified among SS2 surface proteins. We selected eight newly identified proteins and further confirmed their binding activity to FH. The binding of SS2 to immobilized FH decreased dramatically after pre-incubation with anti-FHBPs polyclonal antibodies. We showed for the first time that SS2 also interact specifically with mouse FH. Furthermore, we found that FH play an important role in adherence and invasion of SS2 to HEp-2 cells. Additionally, using a mouse model of intraperitoneal challenge, we confirmed that SS2 pre-incubated with FH enhanced bacteremia and brain invasion, compared with SS2 not pretreated with FH. Taken together, this study provides a useful method to characterize the host-bacteria interactions. These results first indicated that binding of FH to the cell surface improved the adherence and invasion of SS2 to HEp-2 cells, promoting SS2 to resist killing and leading to enhance virulence.

Identification of Novel Laminin- and Fibronectin-binding Proteins by Far-Western Blot: Capturing the Adhesins of Streptococcus suis Type 2.

Bacterial cell wall (CW) and extracellular (EC) proteins are often involved in interactions with extracellular matrix (ECM) proteins such as laminin (LN) and fibronectin (FN), which play important roles in adhesion and invasion. In this study, an efficient method combining proteomic analysis and Far-Western blotting assays was developed to screen directly for bacterial surface proteins with LN- and FN-binding capacity. With this approach, fifteen potential LN-binding proteins and five potential FN-binding proteins were identified from Streptococcus suis serotype 2 (SS2) CW and EC proteins. Nine newly identified proteins, including oligopeptide-binding protein OppA precursor (OppA), elongation factor Tu (EF-Tu), enolase, lactate dehydrogenase (LDH), fructose-bisphosphate aldolase (FBA), 3-ketoacyl-ACP reductase (KAR), Gly ceraldehyde-3-phosphate dehydrogenase (GAPDH), Inosine 5'-monophosphate dehydrogenase (IMPDH), and amino acid ABC transporter permease (ABC) were cloned, expressed, purified and further confirmed by Far-Western blotting and ELISA. Five proteins (OppA, EF-Tu, enolase, LDH, and FBA) exhibited specifically binding activity to both human LN and human FN. Furthermore, seven important recombinant proteins were selected and identified to have the ability to bind Hep-2 cells by the indirect immunofluorescent assay. In addition, four recombinant proteins, and their corresponding polyclonal antibodies, were observed to decrease SS2 adhesion to Hep-2 cells, which indicates that these proteins contribute to the adherence of SS2 to host cell surface. Collectively, these results show that the approach described here represents a useful tool for investigating the host-pathogen interactions.

A 5.5-year surveillance of esophageal and gastric cardia precursors after a population-based screening in China.

BACKGROUND AND AIM: This study aimed to estimate the time to precursor progression and to identify significant predicators. METHODS: One hundred thirty-three precursor and 311 normal cases detected in a population-based screening were surveyed for 5.5 years. Precursor progression was defined as worsening of dysplasia or development of a new precursor. Time to precursor progression was estimated by the Kaplan-Meier method. Significant predicators were estimated by Cox proportional regression. RESULTS: Of the 133 precursor cases, 33.08% (44/133) progressed or recurred, 30.08% (40/133) persisted, and 36.84% (49/133) regressed; of the 311 normal subjects, 13.50% (42/311) developed a precursor. Progression occurred significantly earlier and more frequently with ncreasing histology: with mind dysplasia (mD), 7.8% progressed by 1 year and 23.3% progressed by 5 year; with moderate dysplasia (MD), 18% progressed by 1 year and 70% progressed by 5 years; and with severe dysplasia, 50% progressed by 1 year and 100% progressed by 5 years. The difference between any two groups was significant. In addition, the marginal Lugol-stained mucosa at endoscopic mucosal resection had a progressing risk similar to that of MD, and basal cell hyperplasia was similar to that of mD. Significant predicators for precursor progression included male sex (hazard ratio and 95% CI: 2.74 (1.63-4.60)), age over 50 years (2.31 (1.33-4.02)), family history of upper gastrointestinal cancer (UGIC) (1.56 (1.00-2.45)), multifocal dysplasia (5.11 (3.01-8.68)), and baseline histology. CONCLUSIONS: Sex, age, family history of UGIC, multifocal dysplasia, and baseline histology are significant independent predicators for precursor progression. Patients after endoscopic mucosal resection should be continuously surveyed.

[Investigation of the arsenic levels in ecosystem aspect in water type of endemic arsenicosis area in Datong City].

OBJECTIVE: To investigate the arsenic levels in endemic arsenism in Datong City, Shanxi Province. METHODS: A total of 85 inhabitants from one village in endemic arsenism area in Datong City, Shanxi Province were collected as research subjects. The People's Republic of China health industry standard for endemic arsenism was used to identify and diagnosis the patients. Daily drinking water and soil were collected and detected by atomic fluorescence spectrometry. The content of vegetables were detected by inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: In the study, 85 samples were collected. Arsenic concentration in the daily drinking water were 14.41 - 90.34 µg/L, and the median value was 43.88 µg/L. The arsenic concentration of vegetables were 0.001 - 0.771 mg/kg, and 43.04% of samples, were higher than the maximal permissible limit of As in food. The results that the arsenic concentration of vegetables constant changes in the leaf vegetables > tubers > fruit vegetables. The health risk of intaking arsenic pollution in vegetables up to 71.77%. The arsenic levels in village of four directions were not exceeded the Chinese standards. CONCLUSIONS: Arsenic concentration in drinking water and vegetables are high in waterborn endemic arsenicosis area of Shanxi province. Arsenic in drinking water has been considered as a primary cause of arsenism, but direct intake of arsenic from vegetables can not be ignored.

Oxidative DNA damage of peripheral blood polymorphonuclear leukocytes, selectively induced by chronic arsenic exposure, is associated with extent of arsenic-related skin lesions.

There is increasing evidence that oxidative stress is an important risk factor for arsenic-related diseases. Peripheral blood leukocytes constitute an important defense against microorganisms or pathogens, while the research on the impact of chronic arsenic exposure on peripheral blood leukocytes is much more limited, especially at low level arsenic exposure. The purpose of the present study was to explore whether chronic arsenic exposure affects oxidative stress of peripheral blood leukocytes and possible linkages between oxidative stress and arsenic-induced skin lesions. 75 male inhabitants recruited from an As-endemic region of China were investigated in the present study. The classification of arsenicosis was based on the degree of skin lesions. Arsenic levels were measured in drinking water and urine by Atomic Fluorescence Spectroscopy. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was tested by Enzyme-Linked Immunosorbent Assay. 8-OHdG of peripheral blood leukocytes was evaluated using immunocytochemical staining. 8-OHdG-positive reactions were only present in polymorphonuclear leukocytes (PMNs), but not in monocytes (MNs). The 8-OHdG staining of PMN cytoplasm was observed in all investigated populations, while the 8-OHdG staining of PMN nuclei was frequently found along with the elevated amounts of cell debris in individuals with skin lesion. Urinary arsenic levels were increased in the severe skin lesion group compared with the normal group. No relationship was observed between drinking water arsenic or urine 8-OHdG and the degree of skin lesions. These findings indicated that the target and persistent oxidative stress in peripheral blood PMNs may be employed as a sensitive biomarker directly to assess adverse health effects caused by chronic exposure to lower levels of arsenic.