Liver and muscle in morbid obesity: the interplay of fatty liver and insulin resistance

Introduction

Nonalcoholic fatty liver disease (NAFLD) can be seen as a manifestation of overnutrition. The muscle is a central player in the adaptation to energy overload, and there is an association between fatty-muscle and -liver. We aimed to correlate muscle morphology, mitochondrial function and insulin signaling with NAFLD severity in morbid obese patients.

Methods

Liver and deltoid muscle biopsies were collected during bariatric surgery in NAFLD patients. NAFLD Activity Score and Younossi''s classification for nonalcoholic steatohepatitis (NASH) were applied to liver histology. Muscle evaluation included morphology studies, respiratory chain complex I to IV enzyme assays, and analysis of the insulin signaling cascade. A healthy lean control group was included for muscle morphology and mitochondrial function analyses.

Results

Fifty one NAFLD patients were included of whom 43% had NASH. Intramyocellular lipids (IMCL) were associated with the presence of NASH (OR 12.5, p<0.001), progressive hepatic inflammation (p = 0.029) and fibrosis severity (p = 0.010). There was a trend to an association between IMCL and decreased Akt phosphorylation (p = 0.059), despite no association with insulin resistance. In turn, hepatic steatosis (p = 0.015) and inflammation (p = 0.013) were associated with decreased Akt phosphoryation. Citrate synthase activity was lower in obese patients (p = 0.047) whereas complex I (p = 0.040) and III (p = 0.036) activities were higher, compared with controls. Finally, in obese patients, complex I activity increased with progressive steatosis (p = 0.049) and with a trend with fibrosis severity (p = 0.056).

Conclusions

In morbid obese patients, presence of IMCL associates with NASH and advanced fibrosis. Muscle mitochondrial dysfunction does not appear to be a major driving force contributing to muscle fat accumulation, insulin resistance or liver disease. Importantly, insulin resistance in muscle might occur at a late point in the insulin signaling cascade and be associated with IMCL and NAFLD severity.     

Deep-water rhodolith productivity and growth in the southwestern Atlantic

Rhodolith beds are an important source of marine calcium carbonate worldwide. Dense aggregations are found in deep water in the tropical southwestern Atlantic. In order to understand the distribution of coralline algae that build rhodoliths, algae responses were measured in light levels over their depth range. Qualitative samples were obtained by dredging at 90–100 m depth 80 km offshore of Cabo Frio Island, southeastern Brazil. Histological sections indicate that Mesophyllum engelhartii (Foslie) Adey was the most frequent coralline algae in 22 sampling stations. Its lumpy and thin thallus is characterized by raised multiporate sporangial conceptacles, with cells of similar size and shape around the pore canal. Accretion growth rates were below detectable levels for two rhodolith species. Photosynthetic peak was reached at 0.5–1.5 % of the maximum surface irradiance (10–30 μmol photons m^?2 s^?1) showing an extremely narrow P–I curve of net primary production. Readings of primary production at irradiance close to saturation and lower light levels (5 μmol photons m^?2 s^?1) showed no significant difference, suggesting that rhodoliths are acclimated to restricted light ranges in deep water.     

Vectorial capacity, basic reproduction number, force of infection and all that: formal notation to complete and adjust their classical concepts and equations

A dimensional analysis of the classical equations related to the dynamics of vector-borne infections is presented. It is provided a formal notation to complete the expressions for the Ross' Threshold Theorem, the Macdonald's basic reproduction "rate" and sporozoite "rate", Garret-Jones' vectorial capacity and Dietz-Molineaux-Thomas' force of infection. The analysis was intended to provide a formal notation that complete the classical equations proposed by these authors.     

Extracellular ATP induces cell death in human intestinal epithelial cells

Background

Extracellular ATP is an endogenous signaling molecule released by various cell types and under different stimuli. High concentrations of ATP released into the extracellular medium activate the P2X7 receptor in most inflammatory conditions. Here, we seek to characterize the effects of ATP in human intestinal epithelial cells and to evaluate morphological changes in these cells in the presence of ATP.

Methods

We treated human intestinal epithelial cells with ATP and evaluated the effects of this nucleotide by scanning and transmission electron microscopy analysis and calcium measurements. We used flow cytometry to evaluate apoptosis. We collected human intestinal explants for immunohistochemistry, apoptosis by the TUNEL approach and caspase-3 activity using flow cytometry analyses. We also evaluated the ROS production by flow cytometry and NO secretion by the Griess technique.

Results

ATP treatment induced changes characteristic of cell death by apoptosis and autophagy but not necrosis in the HCT8 cell line. ATP induced apoptosis in human intestinal explants that showed TUNEL-positive cells in the epithelium and in the lamina propria. The explants exhibited a significant increase of caspase-3 activity when the colonic epithelial cells were incubated with IFN-gamma followed by ATP as compared to control cells. In addition, it was found that antioxidants were able to inhibit both the ROS production and the apoptosis induced by ATP in epithelial cells.

General significance

The activation of P2X7 receptors by ATP induces apoptosis and autophagy in human epithelial cells, possibly via ROS production, and this effect might have implications for gut inflammatory conditions.     

Biological evaluation of the bone healing process after application of two potentially osteogenic proteins: an animal experimental model

doi: 10.1111/j.1741‐2358.2011.00526.x
Biological evaluation of the bone healing process after application of two potentially osteogenic proteins: an animal experimental model Objective: The aim of this work was to analyse qualitatively and quantitatively the newly formed bone after insertion of rhBMP‐2 and protein extracted from Hevea brasiliensis (P‐1), associated or not with a carrier in critical bone defects created in Wistar rat calvarial bone, using histological and histomorphometrical analyses. Materials and methods: Eighty‐four male Wistar rats were used, divided into two groups, according to the period of time until the sacrifice (2 and 6 weeks). Each one of these groups was subdivided into six groups with seven animals each, according to the treatments: (1) 5 μg of pure rhBMP‐2, (2) 5 μg of rhBMP‐2/monoolein gel, (3) pure monoolein gel, (4) 5 μg of pure P‐1, (5) 5 μg of P‐1/monoolein gel and (6) critical bone defect controls. The animals were euthanised and the calvarial bone tissue removed for histological and histomorphometrical analyses. Result and conclusion: The results showed an improvement in the bone healing process using the rhBMP‐2 protein, associated or not with a material carrier in relation to the other groups, and this process demonstrated to be time dependent.     

Synthesis, antitubercular evaluation and 3D-QSAR study of N-phenyl-3-(4-fluorophenyl)-4-substituted pyrazole derivatives

As a part of our ongoing research to develop novel antitubercular agents, a series of N-phenyl-3-(4-fluorophenyl)-4-substituted pyrazoles have been synthesized and tested for antimycobacterial activity in vitro against Mycobacterium tuberculosis H37Rv strain using the BACTEC 460 radiometric system. A 3D-QSAR study based on CoMFA and CoMSIA was performed on these pyrazole derivatives to correlate their chemical structures with the observed activity against M. tuberculosis. The CoMFA model provided a significant correlation of steric and electrostatic fields with the biological activity while the CoMSIA model could additionally shed light on the role of hydrogen bonding and hydrophobic features. The important features identified in the 3D-QSAR models have been used to propose new molecules whose activities are predicted higher than the existing systems. This study provides valuable directions to our ongoing endeavor of rationally designing more potent antitubercular agents.     

Intra-Facility Linkage of HIV-Positive Mothers and HIV-Exposed Babies into HIV Chronic Care: Rural and Urban Experience in a Resource Limited Setting

Introduction

Linkage of HIV-infected pregnant women to HIV care remains critical for improvement of maternal and child outcomes through prevention of maternal-to-child transmission of HIV (PMTCT) and subsequent chronic HIV care. This study determined proportions and factors associated with intra-facility linkage to HIV care and Early Infant Diagnosis care (EID) to inform strategic scale up of PMTCT programs.

Methods

A cross-sectional review of records was done at 2 urban and 3 rural public health care facilities supported by the Infectious Diseases Institute (IDI). HIV-infected pregnant mothers, identified through routine antenatal care (ANC) and HIV-exposed babies were evaluated for enrollment in HIV clinics by 6 weeks post-delivery.

Results

Overall, 1,025 HIV-infected pregnant mothers were identified during ANC between January and June, 2012; 267/1,025 (26%) in rural and 743/1,025 (74%) in urban facilities. Of these 375/1,025 (37%) were linked to HIV clinics [67/267(25%) rural and 308/758(41%) urban]. Of 636 HIV-exposed babies, 193 (30%) were linked to EID. Linkage of mother-baby pairs to HIV chronic care and EID was 16% (101/636); 8/179 (4.5%)] in rural and 93/457(20.3%) in urban health facilities. Within rural facilities, ANC registration <28 weeks-of-gestation was associated with mothers'' linkage to HIV chronic care [AoR, 2.0 95% CI, 1.1–3.7, p = 0.019] and mothers'' multi-parity was associated with baby''s linkage to EID; AoR 4.4 (1.3–15.1), p = 0.023. Stigma, long distance to health facilities and vertical PMTCT services affected linkage in rural facilities, while peer mothers, infant feeding services, long patient queues and limited privacy hindered linkage to HIV care in urban settings.

Conclusion

Post-natal linkage of HIV-infected mothers to chronic HIV care and HIV-exposed babies to EID programs was low. Barriers to linkage to HIV care vary in urban and rural settings. We recommend targeted interventions to rapidly improve linkage to antiretroviral therapy for elimination of MTCT.     

Nitrogen-Fixing Bacteria in Eucalyptus globulus Plantations

Eucalypt cultivation is an important economic activity worldwide. In Portugal, Eucalyptus globulus plantations account for one-third of the total forested area. The nutritional requirements of this crop have been well studied, and nitrogen (N) is one of the most important elements required for vegetal growth. N dynamics in soils are influenced by microorganisms, such as diazotrophic bacteria (DB) that are responsible for biological nitrogen fixation (BNF), so the aim of this study was to evaluate and identity the main groups of DB in E. globulus plantations. Samples of soil and root systems were collected in winter and summer from three different Portuguese regions (Penafiel, Gavião and Odemira). We observed that DB communities were affected by season, N fertilization and moisture. Furthermore Bradyrhizobium and Burkholderia were the most prevalent genera in these three regions. This is the first study describing the dynamic of these bacteria in E. globulus plantations, and these data will likely contribute to a better understanding of the nutritional requirements of eucalypt cultivation and associated organic matter turnover.     

High-Grade Cervical Lesions Among Women Attending A Reference Clinic In Brazil: Associated Factors And Comparison Among Screening Methods

Background

Although screening for cervical cancer is recommended for women in most countries, the incidence of cervical cancer is greater in developing countries. Our goal was to determine the prevalence and factors associated with high-grade lesions/cervical cancer among women attending a reference clinic in Brazil and evaluate the correlation of histology with cytology, colposcopy and the high-risk HPV (HR-HPV) tests.

Methods

A cross-sectional study of women attending a colposcopy clinic was carried out. The patients were interviewed to collect demographic, epidemiological and clinical data. Specimens were collected for cervical cytology, Chlamydia trachomatis and HPV testing using the Hybrid Capture (HC) and PCR tests. Colposcopy was performed for all patients and biopsy for histology when cell abnormalities or cervical intraepithelial neoplasia (CIN) were present.

Results

A total of 291 women participated in the study. The median age was 38 years (DIQ: 30–48 years). The prevalence of histologically confirmed high-grade lesions/cervical cancer was 18.2% (95%, CI: 13.8%–22.6%), with 48 (16.5%) cases of CIN-2/CIN-3 and 5 (1.7%) cases of invasive carcinoma. In the final logistic regression model, for ages between 30 and 49 years old [OR = 4.4 (95%: 1.01–19.04), history of smoking [OR = 2.4 (95%, CI: 1.14–5.18)], practice of anal intercourse [OR = 2.4 (95%, CI: 1.10–5.03)] and having positive HC test for HR-HPV [OR = 11.23 (95%, CI: 4 0.79–26, 36)] remained independently associated with high-grade lesions/cervical cancer. A total of 64.7% of the cases CIN-3\Ca in situ were related to HPV-16. Non-oncogenic HPV were only found in CIN-1 biopsy results. Compared to histology, the sensitivity of cytology was 31.8%, the specificity 95.5%; the sensitivity of colposcopy for high-grade lesions/cervical cancer was 51.0%, specificity was 91.4% and the concordance with HPV testing was high.

Conclusions

The results confirm an association of HR-HPV with precursor lesions for cervical cancer. These data emphasize that cytological screening to detect precursor lesions is still important in some regions and that HR-HPV should be included for screening.     

Composite interval mapping and mixed models reveal QTL associated with performance and carcass traits on chicken chromosomes 1, 3, and 4

Interval mapping (IM) implemented in QTL Express or GridQTL is widely used, but presents some limitations, such as restriction to a fixed model, risk of mapping two QTL when there may be only one and no discrimination of two or more QTL using both cofactors located on the same and other chromosomes. These limitations were overcome with composite interval mapping (CIM). We reported QTL associated with performance and carcass traits on chicken chromosomes 1, 3, and 4 through implementation of CIM and analysis of phenotypic data using mixed models. Thirty-four microsatellite markers were used to genotype 360 F₂ chickens from crosses between males from a layer line and females from a broiler line. Sixteen QTL were mapped using CIM and 14 QTL with IM. Furthermore, of those 30 QTL, six were mapped only when CIM was used: for body weight at 35 days (first and third peaks on GGA4), body weight at 41 days (GGA1B and second peak on GGA4), and weights of back and legs (both on GGA4). Three new regions had evidence for QTL presence: one on GGA1B associated with feed intake 35–41 d at 404 cM (LEI0107-ADL0183) and two on GGA4 associated with weight of back at 163 cM (LEI0076-MCW0240) and weight gain 35–41 d, feed efficiency 35–41 d and weight of legs at 241 cM (LEI0085-MCW0174). We dissected one more linked QTL on GGA4, where three QTL for BW35 and two QTL for BW41 were mapped. Therefore, these new regions mapped here need further investigations using high-density SNP to confirm these QTL and identify candidate genes associated with those traits.