Increase in ghrelin levels after weight loss in obese Zucker rats is prevented by gastric banding.

Obes Surg. 2007 Dec;17(12):1599-607. Epub 2007 Nov 30. Increase in ghrelin levels after weight loss in obese Zucker rats is prevented by gastric banding. Monteiro MP, Ribeiro AH, Nunes AF, Sousa MM, Monteiro JD, Aguas AP, Cardoso MH. Department of Anatomy and UMIB (Unit for Multidisciplinary Biomedical Research) of ICBAS (Abel Salazar Institute for the Biomedical Sciences), University of Porto, 4099-003 Porto, Portugal. [email protected] Abstract BACKGROUND: Gastric banding is thought to decrease appetite in addition to the mechanical effects of food restriction, although this has been difficult to demonstrate in human studies. Our aim was to investigate the changes in orexigenic signals in the obese Zucker rat after gastric banding. METHODS: Obese Zucker rats (fa/fa) were submitted to gastric banding (GBP), sham gastric banding fed ad libitum (sham), or sham operation with food restriction, pair-fed to the gastric banding group (sham-PF). Lean Zucker rats (fa/+) were used as additional controls. Body weight and food intake were daily recorded for 21 days after surgery when epididymal fat was weighed and fasting ghrelin and hypothalamic NPY mRNA expression were measured. RESULTS: Gastric banding in obese Zucker rats resulted in a significant decrease of cumulative body weight gain and food intake. Furthermore, gastric banded rats were leaner than Sham-PF, as expressed by a significantly lower epididymal fat weight. Ghrelin levels of gastric banded rats were not increased when compared to sham-operated animals fed ad libitum and were significantly lower than the levels of weight matched sham-PF rats (1116.9 +/- 103.3 g GBP vs 963.2 +/- 54.3 g sham, 3,079.5 +/- 221.6 sham-PF and 2,969.9 +/- 150.9 g lean rats, p < 0.001); hypothalamic NPY mRNA expression was not increased in GBP when compared to sham-operated rats. CONCLUSION: In obese Zucker rats, GBP prevents the increase in orexigenic signals that occur during caloric deprivation. Our data support the hypothesis that sustained weight loss observed after gastric banding does not depend solely on food restriction

Efficiency, energy and economic analysis of twisted tape inserts in a thermosyphon solar flat plate collector with Cu nanofluids

Heat transfer, friction factor and efficiency of a thermosyphon type flat plate collector with and without twisted tape inserts were analyzed experimentally. Water based Cu nanofluids were used as the absorber fluid to receive the heat from solar radiation into the flat plate collector. The experiments were conducted for volume concentrations of 0.1% and 0.3% and twist ratios of H/D = 5, 10 and 15. Results reveal that the heat transfer rate and efficiency of nanofluids increase with the increase of particle volume concentrations. The Nusselt number of 0.3% nanofluid is enhanced up to 20.46%, and it is further enhanced up to 46.90% with twisted tape insert of H/D = 5 with a maximum friction factor penalty of 1.477-times compared to plain collector. The efficiency of the solar collector with water is 52% and it is enhanced to 58% for 0.3% nanofluid, whereas it is further enhanced to 64% for 0.3% nanofluid with twisted tape insert of H/D = 5. Empirical correlations are proposed based on the experimental data for the friction factor and Nusselt number with a standard deviation of less than ±6.5%. The study indicates that for 100 units of solar flat plate collector the use of 0.1% and 0.3% Cu nanofluids leads to weight savings of 284 kg and 567 kg, respectively. The total weight of 100 units of solar flat plate collector is further saved by 767 kg, 1050 kg and 1250 kg for 0.3% nanofluid with twisted tape inserts of H/D = 15, H/D = 10 and H/D = 5, respectively. The collector cost is reduced by 5.66% and 11.33% for 0.1% and 0.3% nanofluids, and it is further reduced to 25% for 0.3% nanofluid with a twisted tape insert of H/D = 5.publishe

Are we interconnected? A qualitative study on the role and perception of different actors on malaria social behaviour change interventions in rural Mozambique

Background: Interconnecting institutions (health and education sector) and community (through a network of community structures) in social and behaviour change (SBC) activities can add value in an effort for malaria prevention towards a long-term objective of elimination. This approach has been implemented since 2011 in some rural districts of Mozambique. The objective of this study is to describe the perceptions of community and institutional actors on malaria prevention interventions in rural Mozambique. Methods: A descriptive qualitative study with a constructivist research paradigm was conducted in October 2018 in two rural districts of Zambezia Province with high malaria burden in Mozambique. Key-informant sampling was used to select the study participants from different actors and layers: malaria community volunteers, health professionals, non-governmental actors, and education professionals. In-depth interviews (IDIs) and focus group discussions (FGDs) were used to explore the perceptions of these actors. Classic content analysis looking for themes and semantics was used, and saturation guided the sample size recruitment. Results: A total of 23 institutional actor IDIs took place, and 8 FGDs were held. Four themes emerged from the content analysis: (1) organizational and functional aspects; (2) knowledge about malaria; (3) perception of institutional actors on SBC and community involvement; and, (4) perception of institutional actors on the coordination and leadership on SBC malaria interventions. Community structures were well organized, linked to the health sector and operational, with good knowledge of malaria prevention. Education sector (school teachers) links with the health sector were in some cases good, and in other cases, non-existent. The importance of SBC interventions for malaria control was recognized by health actors, although the activities are delegated to non-governmental institutions. Domestic budgetary allocation constraints, quality of intervention and lack of SBC standard indicators were also identified by health actors as aspects for improvement. Conclusions: Community structures, volunteers and primary school teachers have good knowledge on malaria prevention and regularly sensitize community members and students. Institutional health actors and partners recognize their role on malaria prevention activities, however, more interconnection is needed at different levels.publishersversionpublishe

Effects of starch/polycaprolactone-based blends for spinal cord injury regeneration in neurons/glial cells viability and proliferation

Spinal cord injury (SCI) leads to drastic alterations on the quality of life of afflicted individuals. With the advent of Tissue Engineering and Regenerative Medicine where approaches combining biomaterials, cells and growth factors are used, one can envisage novel strategies that can adequately tackle this problem. The objective of this study was to evaluate a blend of starch with poly(ε-caprolactone) (SPCL) aimed to be used for the development of scaffolds spinal cord injury (SCI) repair. SPCL linear parallel filaments were deposited on polystyrene coverslips and assays were carried out using primary cultures of hippocampal neurons and glial cells. Light and fluorescence microscopy observations revealed that both cell populations were not negatively affected by the SPCL-based biomaterial. MTS and total protein quantification indicated that both cell viability and proliferation rates were similar to controls. Both neurons and astrocytes occasionally contacted the surface of SPCL filaments through their dendrites and cytoplasmatic processes, respectively, while microglial cells were unable to do so. Using single cell [Ca2+ ]i imaging, hippocampal neurons were observed growing within the patterned channels and were functional as assessed by the response to a 30 mM KCl stimulus. The present data demonstrated that SPCL-based blends are potentially suitable for the development of scaffolds in SCI regenerative medicine.Portuguese Foundation for Science and Technology through funds from POCTI and/or FEDER programs (Funding to ICVS, 3B's Research Group and post doctoral fellowship to A.J. Salgado-SFRH/BPD/17595/2004)

Malaria prevention knowledge, attitudes, and practices in Zambezia Province, Mozambique

Funding Information: This study was funded by the Principal Investigator as part of her Ph.D. thesis. The findings and conclusions in this report are those of the authors. Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Background: In Mozambique, socio-economic and cultural factors influence the wide adoption of disease preventive measures that are relevant for malaria control strategies to promote early recognition of disease, prompt seeking of medical care, sleeping under insecticide-treated nets (ITNs), and taking intermittent preventive treatment for pregnant women. However, there is a critical information gap regarding previous and ongoing malaria social and behavioural change (SBC) interventions. The aim of this study is to assess the knowledge, attitudes, practices of beneficiaries of SBC interventions. Methods: A descriptive cross-sectional survey was undertaken in 2018 in two rural districts of Zambezia Province, Mozambique. A structured questionnaire was administered to 773 randomly selected households. Respondents were the adult heads of the households. Descriptive statistics were done. Results: The main results show that 96.4% of respondents recalled hearing about malaria in the previous 6 months, 90.0% had knowledge of malaria prevention, and 70.0% of preventive measures. Of the 97.7% respondents that had received ITNs through a mass ITN distribution campaign, 81.7% had slept under an ITN the night before the survey. In terms of source of health information, 70.5% mentioned the role of community volunteers in dissemination of malaria prevention messages, 76.1% of respondents considered worship places (churches and mosques) to be the main places where they heard key malaria prevention messages, and 79.1% asserted that community dialogue sessions helped them better understand how to prevent malaria. Conclusions: Results show that volunteers/activists/teachers played an important role in dissemination of key malaria prevention messages, which brought the following successes: community actors are recognized and people have knowledge of malaria transmission, signs and symptoms, preventive measures, and where to get treatment. There is, however, room for improvement on SBC messaging regarding some malaria symptoms (anaemia and convulsions) and operational research is needed to ascertain the drivers of malaria prevalence and inform the SBC approach.publishersversionpublishe

The discontinuous nature of chromospheric activity evolution

Chromospheric activity has been thought to decay smoothly with time and, hence, to be a viable age indicator. Measurements in solar type stars in open clusters seem to point to a different conclusion: chromospheric activity undergoes a fast transition from Hyades level to that of the Sun after about 1 Gyr of main--sequence lifetime and any decaying trend before or after this transition must be much less significant than the short term variations.Comment: 6 pages, 1 figure, to be published in Astrophysics and Space Scienc

Epithelial IL-6 trans-signaling defines a new asthma phenotype with increased airway inflammation

Background: Although several studies link high levels of IL-6 and soluble IL-6 receptor (sIL-6R) to asthma severity and decreased lung function, the role of IL-6 trans-signaling (IL-6TS) in asthmatic patients is unclear. Objective: We sought to explore the association between epithelial IL-6TS pathway activation and molecular and clinical phenotypes in asthmatic patients. Methods: An IL-6TS gene signature obtained from air-liquid interface cultures of human bronchial epithelial cells stimulated with IL-6 and sIL-6R was used to stratify lung epithelial transcriptomic data (Unbiased Biomarkers in Prediction of Respiratory Disease Outcomes [U-BIOPRED] cohorts) by means of hierarchical clustering. IL-6TS-specific protein markers were used to stratify sputum biomarker data (Wessex cohort). Molecular phenotyping was based on transcriptional profiling of epithelial brushings, pathway analysis, and immunohistochemical analysis of bronchial biopsy specimens. Results: Activation of IL-6TS in air-liquid interface cultures reduced epithelial integrity and induced a specific gene signature enriched in genes associated with airway remodeling. The IL-6TS signature identified a subset of patients with IL-6TS-high asthma with increased epithelial expression of IL-6TS-inducible genes in the absence of systemic inflammation. The IL-6TS-high subset had an overrepresentation of frequent exacerbators, blood eosinophilia, and submucosal infiltration of T cells and macrophages. In bronchial brushings Toll-like receptor pathway genes were upregulated, whereas expression of cell junction genes was reduced. Sputum sIL-6R and IL-6 levels correlated with sputum markers of remodeling and innate immune activation, in particular YKL-40, matrix metalloproteinase 3, macrophage inflammatory protein 1 beta, IL-8, and IL-1 beta. Conclusions: Local lung epithelial IL-6TS activation in the absence of type 2 airway inflammation defines a novel subset of asthmatic patients and might drive airway inflammation and epithelial dysfunction in these patients.Peer reviewe