Human microbiota characterization in the course of renal transplantation

Recent studies demonstrate that the human microbiota, the collection of microorganisms growing on and in individuals, have numerous bidirectional interactions with the host, influencing immunity, resistance to infection, inflammation and metabolism. Little has been done to study the potential associations between microbiota composition and transplant outcome. Here, we investigated the longitudinal changes in the blood, urinary, oral and rectal microbiota of renal allograft recipients before and at 1 and 6 months after transplantation. The results showed major changes in microbiota composition as a result of the transplant episode and associated medications, and these changes persisted over time. The high interindividual variation as well as differences in response to transplantation suggested that it is unlikely that the same specific microbiota members can serve as universal diagnostic markers. Rather, longitudinal changes in each individual's microbiota have the potential to be indicative of health or disease. Use of sensitive nucleic acid-based testing showed that urine, irrespective of disease states, more often harbors a diverse microbiota than appreciated by conventional culture techniques. These results lay the groundwork to construct more comprehensive future investigations to identify microbiota characteristics that can serve as diagnostic markers for transplant health and to guide intervention strategies to improve transplant outcome.

N-glycosylation of the premembrane protein of Japanese encephalitis virus is critical for folding of the envelope protein and assembly of virus-like particles

Premembrane (prM) and envelope (E) proteins, the major structural proteins of Japanese encephalitis virus (JEV) each contain single potential N-glycosylation site. In this study, the role of N-glycosylation of these proteins on their folding and activity were investigated. Three mutant prM and/or E (prM-E) genes lacking N-glycosylation sites were generated by site-directed mutagenesis. The effects of the N-glycan on folding, secretion and cytotoxicity of mutant proteins were determined by comparison with their wild type (wt) counterparts. Removal of N-glycan from the prM protein resulted in a complete misfolding of the E protein and failure to form virus-like particles (VLPs). A similar removal of N-glycan from the E protein led to a low efficiency of its folding and VLPs formation. The secretion and cytotoxicity of the E protein was also markedly impaired in case the glycosylation sites in the prM or E or both proteins were removed. These results suggest that the N-glycosylation of the prM protein is critical to the folding of the E protein, which makes it pivotal in the cytotoxicity of JEV particles and their production.

Risk factors for anal fistula: a case-control study

BACKGROUND

The aim of our study was to identify potential risk factors for anal fistula in order to improve prevention and treatment of anal fistula.

METHODS

A retrospective case-control study for anal fistula was conducted at our unit. Logistic regression analyses were carried out to identify associated risk factors for anal fistula.

RESULTS

The final model obtained by the stepwise forward logistic regression analysis method identified the following items as independent risk factors: body mass index of >25.0 kg/m(2), high daily salt intake, history of diabetes, hyperlipidemia, dermatosis, anorectal surgery, history of smoking and alcohol intake, sedentary lifestyle, excessive intake of spicy/greasy food, very infrequent participation in sports and prolonged sitting on the toilet for defecation.

CONCLUSIONS

Our results indicate that lifestyle factors and certain medical conditions increase an individual's risk of developing anal fistula.

Association study of circulating endothelial progenitor cells and plasma prostacyclin levels in pulmonary hypertension rats

The aim of this study was to investigate the correlation between circulating endothelial progenitor cell (EPC) levels and plasma prostacyclin (PGI2) concentrations in pulmonary hypertension (PH) rat models. Monocrotaline was used to induce PH, and the number of CD34/Flk-1-double-positive mononuclear cells in peripheral CD45-negative blood was counted by flow cytometry, which reflected EPC circulation. The Greiss method was used to detect the plasma PGI2 concentration. Simple linear regression analysis was used to analyze the relationship between EPC and PGI2. Furthermore, the expressions of cycled EPC, CD34, and Flk-1 were detected under in vitro culture conditions. The mean circulating EPC level in the PH model group (0.013 ± 0.004%) was significantly lower (P < 0.01) than that in the control group (0.036 ± 0.009%). The concentration of plasma PGI2 also significantly decreased (24.36 ± 2.08 vs 58.34 ± 3.31 μM; P < 0.01). There was a positive correlation between EPC and PGI2 (r = 0.870, P < 0.05). Under in vitro culture conditions, the EPC number and the CD34 and Flk-1 expression levels in the PH model group were significantly lower than those in the control group. Together, these results suggest that the occurrence of PH may be associated with decreased plasma PGI2 concentrations, resulting in the reduction of circulating EPC.

Src regulates angiogenic factors and vascular permeability after focal cerebral ischemia-reperfusion

Developing new strategies to treat cerebral ischemic-reperfusion injury will require a better understanding of the mechanisms that underlie vascular permeability. In this study we examined the temporal expression of Src and angiogenic factors in rat brain after focal cerebral ischemia and reperfusion and analyzed the relationships among those factors. We also investigated the effect of Src inhibitor PP1 (4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine) in ischemic reperfusion. Rats were subjected to middle cerebral artery occlusion for 90 min followed by reperfusion with or without PP1 treatment. Src mRNA increased at 3h after reperfusion and then gradually declined. Phosphorylation of Src at Y418 displayed a biphasic increase. Phosphorylation increased as early as 3h and peaked at 6h; after decreasing, it peaked again at 3-7 days. Increases in Src mRNA and phosphorylation correlated positively with levels of vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2), and negatively with levels of angiopoietin-1 (Ang-1) and zonula occludens-1 (ZO-1). Changes in the expression of these factors correlated with the progress of vascular permeability, especially early after reperfusion. Hence, dynamic temporal changes in Src Y418 phosphorylation may modulate vascular permeability after cerebral ischemia and reperfusion. PP1 effectively decreased Src Y418 phosphorylation and the expression of VEGF and Ang-2 and increased the expression of Ang-1 and ZO-1. It also reduced cerebral infarct size and neurologic dysfunction. Therefore, Src may represent a new therapeutic target for reducing tissue damage caused by increased vascular permeability.

Immune-monitoring in Kawasaki disease patients treated with infliximab and intravenous immunoglobulin

The expansion of regulatory T cells (Treg ) controls inflammation in children with acute Kawasaki disease (KD). Blockade of tumour necrosis factor (TNF)-α is an emerging therapy for KD patients with refractory inflammation, but there is concern that this therapy could impede the host immune regulation. To define the effect of TNF-α blockade, we conducted ex-vivo immune-monitoring in KD subjects who participated in a randomized, double-blind, placebo-controlled clinical trial of the addition of infliximab to standard intravenous immunoglobulin (IVIG) therapy. We enumerated circulating myeloid and plasmocytoid dendritic cells (DC), regulatory T cells (Treg ) and memory T cells (Tmem ) in 14 consecutive, unselected KD patients (seven treated with IVIG, seven with IVIG + infliximab) at three time-points: (i) acute phase prior to treatment, (ii) subacute phase and (iii) convalescent phase. Myeloid DC (mDC), but not plasmacytoid DC (pDC), were numerous in the peripheral blood in acute KD subjects and decreased in the subacute phase in both IVIG(-) and IVIG (+)  infliximab-treated groups. The co-stimulatory molecule for antigen presentation to T cells and CD86 decreased in mDC from acute to subacute time-points in both treatment groups, but not in the single patient who developed coronary artery aneurysms. We also defined tolerogenic mDC that expand in the subacute phase of KD not impaired by infliximab treatment. Treg and Tmem expanded after treatment with no significant differences between the two groups. Treatment of KD patients with infliximab does not adversely affect generation of tolerogenic mDC or the development of T cell regulation and memory.

DSPP contains an IRES element responsible for the translation of dentin phosphophoryn

The major phosphoprotein in dentin is the aspartic acid and serine-rich protein called dentin phosphophoryn (DPP). DPP appears to be synthesized as a part of a larger compound protein, dentin sialophosphoprotein (DSPP). DSPP has never been isolated or detected in dentin extracts. It is now evident that DSPP is a chimeric protein composed of 3 parts: dentin sialoprotein (DSP), DPP, and dentin glycoprotein (DGP). Previous reports have suggested that the BMP1 protease is responsible for processing DSPP. However, unequal amounts of these products are present in the dentin matrix. Here, we provide evidence for an internal ribosome entry site in the DSPP gene that directs the synthesis of DPP. This mechanism would account for unequal amounts of intracellular DSP and DPP. The internal ribosomal entry site (IRES) activity varied in different cell types, suggesting the presence of additional regulatory elements during the translational regulation of DPP. Further, we provide evidence that DPP is transported to the extracellular matrix (ECM) through exosomes. Using tissue recombination and lentivirus-mediated gain-of-function approaches, we also demonstrate that DPP is essential for the formation of well-defined tooth structures with mineralized dentin matrix.

Source identification of nitrous oxide on autotrophic partial nitrification in a granular sludge reactor

Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern since N2O is a major stratospheric ozone-depleting substance and an important greenhouse gas. The emission of N2O from a lab-scale granular sequencing batch reactor (SBR) for partial nitrification (PN) treating synthetic wastewater without organic carbon was therefore determined in this study, because PN process is known to produce more N2O than conventional nitrification processes. The average N2O emission rate from the SBR was 0.32 ± 0.17 mg-N L(-1) h(-1), corresponding to the average emission of N2O of 0.8 ± 0.4% of the incoming nitrogen load (1.5 ± 0.8% of the converted NH4(+)). Analysis of dynamic concentration profiles during one cycle of the SBR operation demonstrated that N2O concentration in off-gas was the highest just after starting aeration whereas N2O concentration in effluent was gradually increased in the initial 40 min of the aeration period and was decreased thereafter. Isotopomer analysis was conducted to identify the main N2O production pathway in the reactor during one cycle. The hydroxylamine (NH2OH) oxidation pathway accounted for 65% of the total N2O production in the initial phase during one cycle, whereas contribution of the NO2(-) reduction pathway to N2O production was comparable with that of the NH2OH oxidation pathway in the latter phase. In addition, spatial distributions of bacteria and their activities in single microbial granules taken from the reactor were determined with microsensors and by in situ hybridization. Partial nitrification occurred mainly in the oxic surface layer of the granules and ammonia-oxidizing bacteria were abundant in this layer. N2O production was also found mainly in the oxic surface layer. Based on these results, although N2O was produced mainly via NH2OH oxidation pathway in the autotrophic partial nitrification reactor, N2O production mechanisms were complex and could involve multiple N2O production pathways.

Ang(1-7) treatment attenuates β-cell dysfunction by improving pancreatic microcirculation in a rat model of Type 2 diabetes

AIMS

Pancreatic microcirculation plays a pivotal role in the physiological function and survival of β-cells. Ang(1- 7) is a novel component of the renin angiotensin system (RAS) that has beneficial effects on microcirculation. In the present study, we investigated the effects of systemic Ang(1-7) administration (with or without its receptor Mas antagonist A- 779) on pancreatic microcirculation and β-cell function.

METHODS

These effects were studied in vivo using a rat model of Type 2 diabetes (T2DM). Pancreatic microcirculation and islet microvessel density were measured; and β-cell function, insulin content, and the apoptosis of islet cells were assessed, respectively. Additionally, we evaluated endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) concentration in islets.

RESULTS

After Ang(1-7) intervention, pancreatic microcirculation and intra-islet microvessel density were significantly improved (p<0.05), and more importantly, first-phase insulin secretion of β-cells as well as relative insulin content in islets were increased, and the amount of apoptotic islet cells was decreased (p<0.05). And eNOS expression and NO release were up-regulated in pancreatic islets by Ang(1-7) administration (p<0.05). These positive effects of Ang(1-7) were prevented by the addition of A-779 (p<0.05).

CONCLUSIONS

Our findings suggest that systemic Ang(1-7) treatment could attenuate β-cell dysfunction and ameliorate islet cell apoptosis in T2DM rats by improving pancreatic microcirculation, perhaps through the mechanism of endothelial vasodilation.

Microbial basis of oral malodor development in humans

To better understand the microbial basis of oral malodor development in humans, we used a cross-sectional and longitudinal study design and the pyrosequencing approach to track and compare the tongue microbiota associated with oral malodor in 29 Chinese adults who underwent a consecutive three-day evaluation for the amount of H2S excreted orally. Three levels of the oral malodor state (healthy, oral malodor, and severe oral malodor) were defined based on the H2S level. Community structure of the tongue plaques was more sensitive to changes of malodor state than to interpersonal variations or differences in sampling times. Within each individual, the structure of microbiota was relatively stable, while their variations were correlated with the change in the H2S level. Severe oral malodor microbiota were the most conserved in community structure, whereas the healthy ones were relatively varied. Oral-malodor-associated bacteria were identified. The relative abundance of Leptotrichia and Prevotella was positively correlated with oral malodor severity, whereas Hemophilus and Gemella exhibited a negative relationship with oral malodor severity. Our study provides one of the first landscapes of oral microbiota changes associated with oral malodor development and reveals microbes potentially useful to the evaluation and control of oral malodor.

Analysis of differentially expressed genes in placental tissues of preeclampsia patients using microarray combined with the Connectivity Map database

Preeclampsia (PE), which affects 2-7% of human pregnancies, causes significant maternal and neonatal morbidity and mortality. To better understand the pathophysiology of PE, the gene expression profiles of placental tissue from 5 controls and 5 PE patients were assessed using microarray. A total of 224 transcripts were significantly differentially expressed (>2-fold change and q value <0.05, SAM software). Gene Ontology (GO) enrichment analysis indicated that genes involved in hypoxia and oxidative and reductive processes were significantly changed. Three differentially expressed genes (DEGs) involved in these biological processes were further verified by quantitative real-time PCR. Finally, the potential therapeutic agents for PE were explored via the Connectivity Map database. In conclusion, the data obtained in this study might provide clues to better understand the pathophysiology of PE and to identify potential therapeutic agents for PE patients.

Simultaneous optimization of spin fluctuations and superconductivity under pressure in an iron-based superconductor

We present a high-pressure NMR study of the overdoped iron pnictide superconductor NaFe0.94Co0.06As. The low-energy antiferromagnetic spin fluctuations in the normal state, manifest as the Curie-Weiss upturn in the spin-lattice relaxation rate 1/(75)T1T, first increase strongly with pressure but fall again at P>Popt=2.2  GPa. Neither long-ranged magnetic order nor a structural phase transition is encountered up to 2.5 GPa. The superconducting transition temperature Tc shows a pressure dependence identical to the spin fluctuations. Our observations demonstrate that magnetic correlations and superconductivity are optimized simultaneously as a function of the electronic structure, thereby supporting very strongly a magnetic origin of superconductivity.

Association of serum pigment epithelium-derived factor with high-sensitivity C-reactive protein in women with polycystic ovary syndrome

BACKGROUND

The basic studies showed that Pigment epithelium-derived factor (PEDF) plays an important role in inflammation.

AIM

This study aims to investigate the association of serum PEDF with high-sensitivity C-reactive protein (hs-CRP) in women with polycystic ovary syndrome (PCOS).

METHODS

Ninety-six PCOS women and 63 healthy, age-matched controls were enrolled in this study. Serum levels of PEDF, hs-CRP, Complement C3 (C3), glucose, insulin, lipids, and total testosterone were measured. Ninety-six PCOS women and 20 controls underwent hyperinsulinemiceuglycemic clamp to assess their insulin sensitivity, which was expressed as M value.

RESULTS

Serum PEDF levels and hs- CRP levels were much higher in PCOS women than in controls. In PCOS women, PEDF positively correlated with body mass index (BMI), hs-CRP, C3, LDL cholesterol (LDL-c), and systolic blood pressure (SBP), and negatively correlated with M value and HDL cholesterol (HDL-c). After controlling for BMI, PEDF was still positively correlated with hs-CRP. Multiple linear regression analysis revealed that in PCOS women, hs-CRP, SBP, LDL-c and M value were independent determinants of serum PEDF.

CONCLUSION

The serum PEDF levels are closely associated with hs-CRP in women with PCOS. PEDF may play a role in the development of chronic inflammation in PCOS.

Unsupervised content classification based nonrigid registration of differently stained histology images

Registration of histopathology images of consecutive tissue sections stained with different histochemical or immunohistochemical stains is an important step in a number of application areas, such as the investigation of the pathology of a disease, validation of MRI sequences against tissue images, multiscale physical modeling, etc. In each case, information from each stain needs to be spatially aligned and combined to ascertain physical or functional properties of the tissue. However, in addition to the gigabyte-size images and nonrigid distortions present in the tissue, a major challenge for registering differently stained histology image pairs is the dissimilar structural appearance due to different stains highlighting different substances in tissues. In this paper, we address this challenge by developing an unsupervised content classification method that generates multichannel probability images from a roughly aligned image pair. Each channel corresponds to one automatically identified content class. The probability images enhance the structural similarity between image pairs. By integrating the classification method into a multiresolution-block-matching-based nonrigid registration scheme (N. Roberts, D. Magee, Y. Song, K. Brabazon, M. Shires, D. Crellin, N. Orsi, P. Quirke, and D. Treanor, "Toward routine use of 3D histopathology as a research tool," Amer. J. Pathology, vol. 180, no. 5, 2012.), we improve the performance of registering multistained histology images. Evaluation was conducted on 77 histological image pairs taken from three liver specimens and one intervertebral disc specimen. In total, six types of histochemical stains were tested. We evaluated our method against the same registration method implemented without applying the classification algorithm (intensity-based registration) and the state-of-the-art mutual information based registration. Superior results are obtained with the proposed method.

ImaGiNe Seldinger: first simulator for Seldinger technique and angiography training

In vascular interventional radiology, procedures generally start with the Seldinger technique to access the vasculature, using a needle through which a guidewire is inserted, followed by navigation of catheters within the vessels. Visual and tactile skills are learnt in a patient apprenticeship which is expensive and risky for patients. We propose a training alternative through a new virtual simulator supporting the Seldinger technique: ImaGiNe (imaging guided interventional needle) Seldinger. It is composed of two workstations: (1) a simulated pulse is palpated, in an immersive environment, to guide needle puncture and (2) two haptic devices provide a novel interface where a needle can direct a guidewire and catheter within the vessel lumen, using virtual fluoroscopy. Different complexities are provided by 28 real patient datasets. The feel of the simulation is enhanced by replicating, with the haptics, real force and flexibility measurements. A preliminary validation study has demonstrated training effectiveness for skills transfer.

The expression of Nek7, FoxM1, and Plk1 in gallbladder cancer and their relationships to clinicopathologic features and survival

PURPOSE

Gallbladder carcinoma (GC) is generally considered as a relatively rare malignancy with poor prognosis. In order to guide clinicians in selecting suitable treatment for GC patients, reliable markers predictive of poor clinical outcome are desirable. This study analyzed the expression of Polo-like kinase 1 (Plk1), Nima related kinases 7 (Nek7) and Forkhead box M1 (FoxM1) in GC tissues and their relationship to clinicopathologic features and survival.

METHODS

We immunohistochemically investigated the 76 specimens of gallbladder carcinoma, pericarcinoma and normal tissues using Nek7, FoxM1 and Plk1 antibodies and analyzed the overall survival time of these 76 patients.

RESULTS

There were significant correlations between the high level expression of Nek7, FoxM1 and Plk1 and the tumor differentiation, Nevin staging and metastasis. The high level expression of Nek7, FoxM1 and Plk1 was significantly associated with shorter overall survival time in univariate analysis (log-rank test), also identified as an independent prognostic factor in multivariate analysis.

CONCLUSION

Nek7, FoxM1 and Plk1 were significantly associated with certain clinicopathologic indices in GC. Evaluation of Nek7, FoxM1 and Plk1 expression may be an important factor in identifying a group of poor GC prognosis.