116 research outputs found

    Hand-grip strength is a simple and effective outcome predictor in esophageal cancer following esophagectomy with reconstruction: a prospective study

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    <p>Abstract</p> <p>Background</p> <p>Surgery for esophageal cancer usually carries considerable complication and mortality rate. Adequate preoperative evaluation is mandatory to decrease complication rate. Hand-grip strength is a useful measure to assess the extent of aging, nutrition and patient's overall condition. Because preoperative nutrition state and physiologic aging process play important roles in postoperative recovery, we would like to know if hand-grip strength is an adequate tool for such evaluation.</p> <p>Material and methods</p> <p>From January 1st, 2007 to December 31, 2008, there was 68 cases underwent esophagectomy with reconstruction due to esophageal cancer in our hospital. After excluding 7 patients of incomplete data and loss of follow-up, there were 61 patients included in the study.</p> <p>Results</p> <p>There were 54 men and 7 women. The mean age is 60.7. Most of patients had squamous cell carcinoma. Patient with weak hand-grip strength prior to operation had exceedingly high rates of complication and mortality within 6 months after operation. Compared to other risk factors, low grip strength has highest relative risks for both mortality and morbidity.</p> <p>Conclusion</p> <p>Because test for hand-grip strength is cheap, not time-consuming and has high predictive value, it may be included in routine preoperative evaluation.</p

    Impact of climate variability on pineapple production in Ghana

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    Background: Climate variations have a considerable impact on crop production. For pineapple, variable temperatures and rainfall patterns are implicated, yet there is limited knowledge of the conditions and consequences of such variations. Pineapple production plays a major role in Ghana, primarily via socioeconomic impacts and the export economy. The aims of this study were to assess the impact of current climatic trends and variations in four pineapple growing districts in Ghana to provide stakeholders, particularly farmers, with improved knowledge for guidance in adapting to changing climate. Results: Trend analysis, standardized anomaly, correlation analysis as well as focus group discussions were employed to describe climate and yields as well as assess the relationship between climate and pineapple production from 1995 to 2014. The results revealed that, relative to Ga district, temperature (minimum and maximum) in the study areas was increasing over this period at a rate of up to 0.05 °C. Rainfall trends increased in all but Nsawam Adoagyiri district. Rainfall and temperature had different impacts on production, and pineapple was particularly sensitive to minimum temperature as accounting for up to 82% of yield variability. Despite consistent report of rainfall impact on growth stages later affecting quantity and quality of fruits, minimal statistical significance was found between rainfall and yield. Conclusions: With continuously increasing stresses imposed by a changing climate, the sustainability of pineapple production in Ghana is challenged. This subsequently has detrimental impacts on national employment and exports capacity resulting in increased poverty. Further research to explore short- and long-term adaption options in response to challenging conditions in the pineapple industry in Ghana is suggested

    Evaluation of Phage Display Discovered Peptides as Ligands for Prostate-Specific Membrane Antigen (PSMA)

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    The aim of this study was to identify potential ligands of PSMA suitable for further development as novel PSMA-targeted peptides using phage display technology. The human PSMA protein was immobilized as a target followed by incubation with a 15-mer phage display random peptide library. After one round of prescreening and two rounds of screening, high-stringency screening at the third round of panning was performed to identify the highest affinity binders. Phages which had a specific binding activity to PSMA in human prostate cancer cells were isolated and the DNA corresponding to the 15-mers were sequenced to provide three consensus sequences: GDHSPFT, SHFSVGS and EVPRLSLLAVFL as well as other sequences that did not display consensus. Two of the peptide sequences deduced from DNA sequencing of binding phages, SHSFSVGSGDHSPFT and GRFLTGGTGRLLRIS were labeled with 5-carboxyfluorescein and shown to bind and co-internalize with PSMA on human prostate cancer cells by fluorescence microscopy. The high stringency requirements yielded peptides with affinities KD∼1 μM or greater which are suitable starting points for affinity maturation. While these values were less than anticipated, the high stringency did yield peptide sequences that apparently bound to different surfaces on PSMA. These peptide sequences could be the basis for further development of peptides for prostate cancer tumor imaging and therapy. © 2013 Shen et al

    Age-related changes in global motion coherence: conflicting haemodynamic and perceptual responses

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    Our aim was to use both behavioural and neuroimaging data to identify indicators of perceptual decline in motion processing. We employed a global motion coherence task and functional Near Infrared Spectroscopy (fNIRS). Healthy adults (n = 72, 18-85) were recruited into the following groups: young (n = 28, mean age = 28), middle-aged (n = 22, mean age = 50), and older adults (n = 23, mean age = 70). Participants were assessed on their motion coherence thresholds at 3 different speeds using a psychophysical design. As expected, we report age group differences in motion processing as demonstrated by higher motion coherence thresholds in older adults. Crucially, we add correlational data showing that global motion perception declines linearly as a function of age. The associated fNIRS recordings provide a clear physiological correlate of global motion perception. The crux of this study lies in the robust linear correlation between age and haemodynamic response for both measures of oxygenation. We hypothesise that there is an increase in neural recruitment, necessitating an increase in metabolic need and blood flow, which presents as a higher oxygenated haemoglobin response. We report age-related changes in motion perception with poorer behavioural performance (high motion coherence thresholds) associated with an increased haemodynamic response

    Cryptosporidium Priming Is More Effective than Vaccine for Protection against Cryptosporidiosis in a Murine Protein Malnutrition Model

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    Cryptosporidium is a major cause of severe diarrhea, especially in malnourished children. Using a murine model of C. parvum oocyst challenge that recapitulates clinical features of severe cryptosporidiosis during malnutrition, we interrogated the effect of protein malnutrition (PM) on primary and secondary responses to C. parvum challenge, and tested the differential ability of mucosal priming strategies to overcome the PM-induced susceptibility. We determined that while PM fundamentally alters systemic and mucosal primary immune responses to Cryptosporidium, priming with C. parvum (106 oocysts) provides robust protective immunity against re-challenge despite ongoing PM. C. parvum priming restores mucosal Th1-type effectors (CD3+CD8+CD103+ T-cells) and cytokines (IFNγ, and IL12p40) that otherwise decrease with ongoing PM. Vaccination strategies with Cryptosporidium antigens expressed in the S. Typhi vector 908htr, however, do not enhance Th1-type responses to C. parvum challenge during PM, even though vaccination strongly boosts immunity in challenged fully nourished hosts. Remote non-specific exposures to the attenuated S. Typhi vector alone or the TLR9 agonist CpG ODN-1668 can partially attenuate C. parvum severity during PM, but neither as effectively as viable C. parvum priming. We conclude that although PM interferes with basal and vaccine-boosted immune responses to C. parvum, sustained reductions in disease severity are possible through mucosal activators of host defenses, and specifically C. parvum priming can elicit impressively robust Th1-type protective immunity despite ongoing protein malnutrition. These findings add insight into potential correlates of Cryptosporidium immunity and future vaccine strategies in malnourished children

    Pyrethroid Resistance Reduces the Efficacy of Space Sprays for Dengue Control on the Island of Martinique (Caribbean)

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    The mosquito Aedes aegypti is the major vector of the Dengue virus in human populations and is responsible of serious outbreaks worldwide. In most countries, vector control is implemented by the use of insecticides to reduce mosquito populations. During epidemics, insecticides of the pyrethroid family (blocking the voltage gated sodium channel protein in the nerve sheath) are used by space spraying with vehicle mounted thermal foggers to kill adult mosquitoes. Unfortunately some populations of Ae. aegypti have become resistant to these insecticides, leading to operational challenges for public health services. In Martinique (French West Indies), resistance to pyrethroids was detected in the 1990s. The present study assessed the impact of this resistance on the efficacy of vector control operations in 9 localities of Martinique. Here we showed that the resistance strongly reduces the efficacy of pyrethroid-based treatments, thus emphasizing the urgent need for alternative insecticides or tools to reduce dengue transmission

    Maternal environment shapes the life history and susceptibility to malaria of Anopheles gambiae mosquitoes

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    BACKGROUND: It is becoming generally recognized that an individual's phenotype can be shaped not only by its own genotype and environmental experience, but also by its mother's environment and condition. Maternal environmental factors can influence mosquitoes' population dynamics and susceptibility to malaria, and therefore directly and indirectly the epidemiology of malaria. METHODS: In a full factorial experiment, the effects of two environmental stressors - food availability and infection with the microsporidian parasite Vavraia culicis - of female mosquitoes (Anopheles gambiae sensu stricto) on their offspring's development, survival and susceptibility to malaria were studied. RESULTS: The offspring of A. gambiae s.s. mothers infected with V. culicis developed into adults more slowly than those of uninfected mothers. This effect was exacerbated when mothers were reared on low food. Maternal food availability had no effect on the survival of their offspring up to emergence, and microsporidian infection decreased survival only slightly. Low food availability for mothers increased and V. culicis-infection of mothers decreased the likelihood that the offspring fed on malaria-infected blood harboured malaria parasites (but neither maternal treatment influenced their survival up to dissection). CONCLUSIONS: Resource availability and infection with V. culicis of A. gambiae s.s. mosquitoes not only acted as direct environmental stimuli for changes in the success of one generation, but could also lead to maternal effects. Maternal V. culicis infection could make offspring more resistant and less likely to transmit malaria, thus enhancing the efficacy of the microsporidian for the biological control of malaria

    Differential Effects of Pravastatin and Simvastatin on the Growth of Tumor Cells from Different Organ Sites

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    3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) inhibitors, commonly known as statins, may possess cancer preventive and therapeutic properties. Statins are effective suppressors of cholesterol synthesis with a well-established risk-benefit ratio in cardiovascular disease prevention. Mechanistically, targeting HMGCR activity primarily influences cholesterol biosynthesis and prenylation of signaling proteins. Pravastatin is a hydrophilic statin that is selectively taken up by a sodium-independent organic anion transporter protein-1B1 (OATP1B1) exclusively expressed in liver. Simvastatin is a hydrophobic statin that enters cells by other mechanisms. Poorly-differentiated and well-differentiated cancer cell lines were selected from various tissues and examined for their response to these two statins. Simvastatin inhibited the growth of most tumor cell lines more effectively than pravastatin in a dose dependent manner. Poorly-differentiated cancer cells were generally more responsive to simvastatin than well-differentiated cancer cells, and the levels of HMGCR expression did not consistently correlate with response to statin treatment. Pravastatin had a significant effect on normal hepatocytes due to facilitated uptake and a lesser effect on prostate PC3 and colon Caco-2 cancer cells since the OATP1B1 mRNA and protein were only found in the normal liver and hepatocytes. The inhibition of cell growth was accompanied by distinct alterations in mitochondrial networks and dramatic changes in cellular morphology related to cofilin regulation and loss of p-caveolin. Both statins, hydrophilic pravastatin and hypdrophobic simvastatin caused redistribution of OATP1B1 and HMGCR to perinuclear sites. In conclusion, the specific chemical properties of different classes of statins dictate mechanistic properties which may be relevant when evaluating biological responses to statins

    Glucose Transporter 1 and Monocarboxylate Transporters 1, 2, and 4 Localization within the Glial Cells of Shark Blood-Brain-Barriers

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    Although previous studies showed that glucose is used to support the metabolic activity of the cartilaginous fish brain, the distribution and expression levels of glucose transporter (GLUT) isoforms remained undetermined. Optic/ultrastructural immunohistochemistry approaches were used to determine the expression of GLUT1 in the glial blood-brain barrier (gBBB). GLUT1 was observed solely in glial cells; it was primarily located in end-feet processes of the gBBB. Western blot analysis showed a protein with a molecular mass of 50 kDa, and partial sequencing confirmed GLUT1 identity. Similar approaches were used to demonstrate increased GLUT1 polarization to both apical and basolateral membranes in choroid plexus epithelial cells. To explore monocarboxylate transporter (MCT) involvement in shark brain metabolism, the expression of MCTs was analyzed. MCT1, 2 and 4 were expressed in endothelial cells; however, only MCT1 and MCT4 were present in glial cells. In neurons, MCT2 was localized at the cell membrane whereas MCT1 was detected within mitochondria. Previous studies demonstrated that hypoxia modified GLUT and MCT expression in mammalian brain cells, which was mediated by the transcription factor, hypoxia inducible factor-1. Similarly, we observed that hypoxia modified MCT1 cellular distribution and MCT4 expression in shark telencephalic area and brain stem, confirming the role of these transporters in hypoxia adaptation. Finally, using three-dimensional ultrastructural microscopy, the interaction between glial end-feet and leaky blood vessels of shark brain was assessed in the present study. These data suggested that the brains of shark may take up glucose from blood using a different mechanism than that used by mammalian brains, which may induce astrocyte-neuron lactate shuttling and metabolic coupling as observed in mammalian brain. Our data suggested that the structural conditions and expression patterns of GLUT1, MCT1, MCT2 and MCT4 in shark brain may establish the molecular foundation of metabolic coupling between glia and neurons
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