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.

A simple novel endoscopic successive suture device: a validation study for closure strength and reproducibility

BACKGROUND AND STUDY AIMS

Endoscopic surgical technology has been developing rapidly. Although several successful endoscopic closure devices have already been introduced, only a few of them have demonstrated improvements in closure strength and reproducibility over conventional endoscopic clip closures or hand sutures. The objective of this study was to test the feasibility of a novel successive suturing device (SSD) by measuring closure strength and reproducibility.

MATERIAL AND METHODS

Porcine stomach models were used in this study. Endoclips, full-thickness hand sutures, and the novel SSD sutures were used to close a perforation in the stomach wall, with 10 stomachs being tested for each closure method. Endoclips and SSD sutures were performed using a two-channel endoscope, and the hand sutures were performed from outside of the stomach wall. Air leakage pressure was measured to determine the closure strength and reproducibility of each method.

RESULTS

The mean air leakage pressure of the SSD closure was 62.7 ± 8.2 mmHg. SSD-treated stomachs exhibited significantly greater air leakage pressure than Endoclip-treated stomachs. The standard deviation of bursting pressure in SSD stomachs was found to be significantly smaller than that of hand-sewn stomachs but was not different from that of Endoclip stomachs.

CONCLUSIONS

The consistent closure strength of SSD stomachs demonstrated the reliability and reproducibility of this new closure method. These promising results in closure strength and reproducibility suggest the feasibility of the proposed device for clinical applications.

Regulatory properties of malic enzyme in the oleaginous yeast, Yarrowia lipolytica, and its non-involvement in lipid accumulation

Malic enzyme (EC 1.1.1.40) converts L-malate to pyruvate and CO2 providing NADPH for metabolism especially for lipid biosynthesis in oleaginous microorganisms. However, its role in the oleaginous yeast, Yarrowia lipolytica, is unclear. We have cloned the malic enzyme gene (YALI0E18634g) from Y. lipolytica into pET28a, expressed it in Escherichia coli and purified the recombinant protein (YlME). YlME used NAD(+) as the primary cofactor. Km values for NAD(+) and NADP(+) were 0.63 and 3.9 mM, respectively. Citrate, isocitrate and α-ketoglutaric acid (>5 mM) were inhibitory while succinate (5-15 mM) increased NADP(+)- but not NAD(+)-dependent activity. To determine if fatty acid biosynthesis could be increased in Y. lipolytica by providing additional NADPH from an NADP(+)-dependent malic enzyme, the malic enzyme gene (mce2) from an oleaginous fungus, Mortierella alpina, was expressed in Y. lipolytica. No significant changes occurred in lipid content or fatty acid profiles suggesting that malic enzyme is not the main source of NADPH for lipid accumulation in Y. lipolytica.

The Roles of Moonlighting Proteins in Bacteria

Moonlighting proteins, characterized by their multiple autonomous functions, have been detected in bacteria. Surprisingly, many of these proteins are conserved and involved in metabolic pathway or the cell stress response. They localise to the bacterial surface to take on additional activities, which have been hypothesised to contribute to bacterial virulence or bacterial benefit. In this review, we compare the functions of moonlighting proteins in bacteria, describe the structural basis of moonlighting functions, and summarise the regulation of secretion and localisation of moonlighting proteins.

Genetic engineering of Yarrowia lipolytica for enhanced production of trans-10, cis-12 conjugated linoleic acid

Background

Conjugated linoleic acid (CLA) has been extensively studied for decades because of its health benefits including cancer prevention, anti-atherogenic and anti-obesity effects, and modulation of the immune system. We previously described the production of trans-10, cis-12 CLA in Yarrowia lipolytica by expressing the gene coding for linoleic acid isomerase from Propionibacterium acnes (pai). However the stable strain produced CLA at about 0.08% of dry cell weight (DCW), a level of production which was not high enough for practical applications. The goal of the present study was to enhance production of CLA by genetic engineering of Y. lipolytica strains.

Results

We have now co-expressed the delta 12-desaturase gene (FADS12, d12) from Mortierella alpina together with the codon-optimized linoleic acid isomerase (opai) gene in Y. lipolytica, expressed under the control of promoter hp16d modified by fusing 12 copies of UAS1B to the original promoter hp4d. A multi-copy integration plasmid was used to further enhance the expression of both genes. Using glucose as the sole carbon source, the genetically-modified Y. lipolytica produced trans-10, cis-12-CLA at a level of up to 10% of total fatty acids and 0.4% of DCW. Furthermore, when the recombinant yeast was grown with soybean oil, trans-10, cis-12-CLA now accumulated at a level of up to 44% of total fatty acids, which represented 30% of DCW after 38.5 h of cultivation. In addition, trans-10, cis-12-CLA was also detected in the growth medium up to 0.9 g/l.

Conclusions

We have successfully produced trans-10, cis-12-CLA with a titre of 4 g/l of culture (3.1 g/l in cells and 0.9 g/l in culture medium). Our results demonstrate the potential use of Y. lipolytica as a promising microbial cell factory for trans-10, cis-12-CLA production.

A population-based study of associations between functional gastrointestinal disorders and psychosocial characteristics in Xi'an, China

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are disorders with chronic and recurring gastrointestinal symptoms. This study investigated the prevalence of FGIDs, assessed the association between FGIDs and psychosocial factors, and identified potential risk factors for FGIDs in a population in Xi'an, China.

METHODS

Of 752 recruited residents in Xi'an, 720 were selected for an epidemiological survey using a cluster sampling method. All subjects were interviewed face-to-face to complete the Chinese version of ROME III FGIDs questionnaire, the Symptom Check-List-90, the Eysenck Personality Questionnaire, a Life Event Scale, and a questionnaire regarding personal childhood adversity. The prevalence of FGIDs and associations between FGIDs and psychosocial factors were determined using EpiData Software. Logistic regression analysis was performed to identify the potential risk factors for FGIDs.

KEY RESULTS

The prevalence of FGIDs in this sample population was 14.3% (103/720). There were 13 (1.8%) cases of overlap of different FGIDs. No significant difference in the prevalence of FGIDs was observed between men and women. Alcohol intake and smoking habits were significantly associated with the presence of FGIDs. The presence of FGIDs was significantly associated with psychological factors and influences such as personality type, life events, childhood adversity, and psychopathology. The potential risk factors for contracting FGIDs were certain life events, childhood adversity, somatization, and a hostile affect (P < 0.001).

CONCLUSIONS & INFERENCES

The prevalence of FGIDs and overlap syndrome in Xi'an, China was lower than that reported in other countries. There was a strong correlation between specific lifestyle habits and psychosocial characteristics and the presence of FGIDs.

Developmental changes in diaphragm muscle function in the preterm and postnatal lamb

RATIONALE

The preterm diaphragm is structurally and functionally immature, potentially contributing to an increased risk of respiratory distress and failure. We investigated developmental changes in contractile function and susceptibility to fatigue of the costal diaphragm in the fetal lamb to understand factors contributing to the risk of developing diaphragm dysfunction and respiratory disorders. We hypothesized that the functional capacity of the diaphragm will vary with maturational stage as will its susceptibility to fatigue.

METHODS

Lambs were studied at 75, 100, 125, 145, 154, 168, and 200 days postconceptional age (term = 147 days). Lambs were euthanized (sodium pentobarbitone, 100 mg/kg) either at delivery or immediately prior to post-mortem for postnatal lambs. Contractile function was assessed on longitudinal strips of intact muscle fibers and the remaining tissue frozen in liquid nitrogen for analysis of myosin heavy chain (MHC) mRNA expression and protein content.

RESULTS

Fetal development of diaphragm function was characterized by a significant increase in maximum specific force, increased susceptibility to fatigue, reduced twitch contraction times, and a progressive increase in MHCI and MHCII protein content. Postnatally, there was a progressive decrease in the susceptibility to fatigue that coincided with an increase in the MHC I:II protein ratio.

CONCLUSION

These data indicate that the functional capacity of the diaphragm varies with maturational age and may be an important determinant of the susceptibility to preterm respiratory failure.

Preoperative platelet count in predicting lymph node metastasis and prognosis in patients with non-small cell lung cancer

Recent studies have shown an indirect link between platelet count and blood vessel metastasis, but this association with lymphatic vessels metastasis has not been established in NSCLC. So we investigated whether an association exists between preoperative platelet count and lymph node metastasis in NSCLC patients. Between January 2001 and January 2011, platelet counts were obtained from 883 NSCLC patients who were resistant to chemotherapy, radiotherapy, and surgery. The preoperative platelet counts, tumor metastasis, and overall survival of NSCLC patients were analyzed for correlations via statistical analysis. Upon considering patients according to their TNM lymph node metastasis stage (N0-N3), multiple comparison analyses revealed that the mean preoperative platelet count of the N0 group was significantly lower than that of the N1-N3. Analysis of variance showed that the preoperative platelet count of patients in stage I was significantly lower than that of those in stages II, III, and IV, with no significant difference among the latter three stages. According to the Kaplan-Meier survival analysis, the overall survival of patients with platelet counts <214.5 × 109/L was significantly longer than that of those with platelet counts ≥214.5 × 109/L. Cox regression analysis indicated that, besides preoperative platelet count, patient age, gender, and TNM stage were independent prognostic factors. In conclusion, preoperative platelet count was significantly associated with metastasis of lymph nodes in NSCLC patients. Preoperative platelet count may be a reliable biomarker of lymph node metastasis possibility and an independent prognostic factor of overall survival in patients with NSCLC.