320 research outputs found

    Fc-receptor-mediated phagocytosis occurs in macrophages without an increase in average [Ca++]i

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    The calcium ion has been implicated as a cytosolic signal or regulator in phagocytosis. Using the Ca++-sensitive photoprotein aequorin we have measured intracellular free Ca++ ion concentration ([Ca++]i) in thioglycolate-elicited mouse peritoneal macrophages during phagocytosis and IgG-induced spreading. Macrophages plated on glass were loaded with aequorin and [Ca++]i was then measured from cell populations, both as previously described (McNeil, P. L., and D. L. Taylor, 1985, Cell Calcium, 6:83-92). Aequorin indicated a resting [Ca++]i in adherent macrophages of 84 nM and was responsive to changes in [Ca++]i induced by the addition of Mg-ATP (0.1 mM) or serum to medium. However, during the 15 min required for phagocytosis of seven or eight IgG-coated erythrocytes per macrophage loaded with aequorin, we measured no change in [Ca++]i. Similarly, the ligation of Fc-receptors that occurs when macrophages spread on immune complex-coated coverslips did not change macrophage [Ca++]i. In contrast, a rise in [Ca++]i of macrophages was measured during phagocytosis occurring in a serum-free saline of pH 7.85, and as a consequence of incubation with quin2 A/M. We estimate that had a change in [Ca++]i occurred during phagocytosis, aequorin would have detected a rise from 0.1 to 1.0 microM taking place in as little as 2% of the macrophage's cytoplasmic volume. We therefore suggest that either Ca++ is not involved as a cytoplasmic signal for phagocytosis or that increases in [Ca++]i during phagocytosis are confined to such small regions of cytoplasm as to be below the limits of detection by our cellular averaging method. Our data emphasizes, moreover, the need for well-defined, nonperturbing conditions in such measurements of [Ca++]i

    COVID-19, frailty and long-term care: Implications for policy and practice

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    Older adults have been disproportionately affected by the COVID-19 pandemic, with many outbreaks occurring in Long Term Care Facilities (LTCFs). We discuss this vulnerability among LTCF residents using an ecological framework, on levels spanning from the individual to families and caregivers, institutions, health services and systems, communities, and contextual government policies. Challenges abound for fully understanding the burden of COVID-19 in LTCF, including differences in nomenclature, data collection systems, cultural differences, varied social welfare models, and (often) under-resourcing of the LTC sector. Registration of cases and deaths may be limited by testing capacity and policy, record-keeping and reporting procedures. Hospitalization and death rates may be inaccurate depending on atypical presentations and whether or not residents' goals of care include escalation of care and transfer to hospital. Given the important contribution of frailty, use of the Clinical Frailty Scale (CFS) is discussed as a readily implementable measure, as are lessons learned from the study of frailty in relation to influenza. Biomarkers hold emerging promise in helping to predict disease severity and address the puzzle of why some frail LTCF residents are resilient to COVID-19, either remaining test-negative despite exposure or having asymptomatic infection, while others experience the full range of illness severity including critical illness and death. Strong and coordinated surveillance and research focused on LTCFs and their frail residents is required. These efforts should include widespread assessment of frailty using feasible and readily implementable tools such as the CFS, and rigorous reporting of morbidity and mortality in LTCFs

    The GALNTL6 Gene rs558129 Polymorphism Is Associated With Power Performance

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    Diaz, J, alvarez Herms, J, Castaneda, A, Larruskain, J, Ramirez de la Piscina, X, Borisov, OV, Semenova, EA, Kostryukova, ES, Kulemin, NA, Andryushchenko, ON, Larin, AK, Andryushchenko, LB, Generozov, EV, Ahmetov, II, and Odriozola, A. The GALNTL6 gene rs558129 polymorphism is associated with power performance. J Strength Cond Res 34(11): 3031-3036, 2020-The largest genome-wide association study to date in sports genomics showed that endurance athletes were 1.23 times more likely to possess the C allele of the single nucleotide polymorphism rs558129 of N-acetylgalactosaminyltransferase-like 6 gene (GALNTL6), compared with controls. Nevertheless, no further study has investigated GALNTL6 gene in relation to physical performance. Considering that previous research has shown that the same polymorphism can be associated with both endurance and power phenotypes (ACTN3, ACE, and PPARA), we investigated the association between GALNTL6 rs558129 polymorphism and power performance. According to this objective we conducted 2 global studies regarding 2 different communities of athletes in Spain and Russia. The first study involved 85 Caucasian physically active men from the north of Spain to perform a Wingate anaerobic test (WAnT). In the second study we compared allelic frequencies between 173 Russian power athletes (49 strength and 124 speed-strength athletes), 169 endurance athletes, and 201 controls. We found that physically active men with the T allele of GALNTL6 rs558129 had 5.03-6.97% higher power values compared with those with the CC genotype (p < 0.05). Consistent with these findings, we have shown that the T allele was over-represented in power athletes (37.0%) compared with endurance athletes (29.3%; OR = 1.4, p = 0.032) and controls (28.6%; OR = 1.5, p = 0.015). Furthermore, the highest frequency of the T allele was observed in strength athletes (43.9%; odds ratio [OR] = 1.9, p = 0.0067 compared with endurance athletes; OR = 2.0, p = 0.0036 compared with controls). In conclusion, our data suggest that the GALNTL6 rs558129 T allele can be favorable for anaerobic performance and strength athletes. In addition, we propose a new possible functional role of GALNTL6 rs558129, gut microbiome regarding short-chain fatty acid regulation and their anti-inflammatory and resynthesis functions. Nevertheless, further studies are required to understand the mechanisms involved.The authors would like to thank all the staff and athletes who participated in the study and the ZuOK Center where sports testing were performed. J. Larruskain was supported by a PhD Studentship from the Vice-Chancellorship for Basque of the University of the Basque Country UPV/EHU (EuskararenarlokoErrektoreordetza). J. Diaz and J. Alvarez Herms have contributed equally to this manuscrip

    The Magnitude of Androgen Receptor Positivity in Breast Cancer Is Critical for Reliable Prediction of Disease Outcome

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    Purpose: Consensus is lacking regarding the androgen receptor (AR) as a prognostic marker in breast cancer. The objectives of this study were to comprehensively review the literature on AR prognostication and determine optimal criteria for AR as an independent predictor of breast cancer survival. Experimental Design: AR positivity was assessed by immunostaining in two clinically validated primary breast cancer cohorts [training cohort, n = 219; validation cohort, n = 418; 77% and 79% estrogen receptor alpha (ERα) positive, respectively]. The optimal AR cut-point was determined by ROC analysis in the training cohort and applied to both cohorts. Results: AR was an independent prognostic marker of breast cancer outcome in 22 of 46 (48%) previous studies that performed multivariate analyses. Most studies used cut-points of 1% or 10% nuclear positivity. Herein, neither 1% nor 10% cut-points were robustly prognostic. ROC analysis revealed that a higher AR cut-point (78% positivity) provided optimal sensitivity and specificity to predict breast cancer survival in the training (HR, 0.41; P = 0.015) and validation (HR, 0.50; P = 0.014) cohorts. Tenfold cross-validation confirmed the robustness of this AR cut-point. Patients with ERα-positive tumors and AR positivity ≥78% had the best survival in both cohorts (P 0.87) had the best outcomes (P < 0.0001). Conclusions: This study defines an optimal AR cut-point to reliably predict breast cancer survival. Testing this cut-point in prospective cohorts is warranted for implementation of AR as a prognostic factor in the clinical management of breast cancer

    High Prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae Detected in the Human Gut Using an Improved DNA Detection Protocol

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    Background: The low and variable prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae DNA in human stool contrasts with the paramount role of these methanogenic Archaea in digestion processes. We hypothesized that this contrast is a consequence of the inefficiencies of current protocols for archaeon DNA extraction. We developed a new protocol for the extraction and PCR-based detection of M. smithii and M. stadtmanae DNA in human stool. Methodology/Principal Findings: Stool specimens collected from 700 individuals were filtered, mechanically lysed twice, and incubated overnight with proteinase K prior to DNA extraction using a commercial DNA extraction kit. Total DNA was used as a template for quantitative real-time PCR targeting M. smithii and M. stadtmanae 16S rRNA and rpoB genes. Amplification of 16S rRNA and rpoB yielded positive detection of M. smithii in 95.7% and M. stadtmanae in 29.4% of specimens. Sequencing of 16S rRNA gene PCR products from 30 randomly selected specimens ( 15 for M. smithii and 15 for M. stadtmanae) yielded a sequence similarity of 99-100% using the reference M. smithii ATCC 35061 and M. stadtmanae DSM 3091 sequences. Conclusions/Significance: In contrast to previous reports, these data indicate a high prevalence of the methanogens M. smithii and M. stadtmanae in the human gut, with the former being an almost ubiquitous inhabitant of the intestinal microbiome

    Blunted Medial Prefrontal Cortico-Limbic Reward-Related Effective Connectivity and Depression

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    Stratifying Resilience and Depression Longitudinally (STRADL) was supported by the Wellcome Trust through a Strategic Award (Grant No. 104036/Z/14/Z). Parts of the work were supported by a China Scholarship Council (Grant No. 201506040037 to SX), National Institutes of Health (Grant No. DA027764 to MRD), Lister Institute Prize Fellowship 2016–2021 (to DJS), Dr Mortimer and Theresa Sackler Foundation (AMM, HCW, and SML), Centre for Cognitive Ageing and Cognitive Epidemiology (IJD and AMM), Medical Research Council and Biotechnology and Biological Sciences Research Council (Grant No. MR/K026992/1), Royal College of Physicians of Edinburgh John, Margaret, Alfred and Stewart Sim fellowship (to HCW), and University of Edinburgh, Edinburgh Scientific Academic TmPCk College Fellowship (to HCW). The Chief Scientist Office of the Scottish Government Health Department (Grant No. CZD/16/6) and Scottish Funding Council (Grant No. HR03006) provided core support for Generation Scotland. Data acquisition was additionally supported by the Scottish Mental Health Research Network and Scottish Government’s Support for Science initiative. LR, HCW, and AMM, received financial support from Pfizer (formerly Wyeth) in relation to imaging studies of people with schizophrenia and bipolar disorder. AMM has previously received grant support from Lilly and Janssen. SML has received honoraria for lectures, chairing meetings, and consultancy work from Janssen in connection with brain imaging and therapeutic initiatives for psychosis. JDS has received funding via an honorarium associated with a lecture or Wyeth and funding from Indivior for a study on opioid dependency. No other disclosures were reported. The authors declare no conflict of interest.Peer reviewedPublisher PD

    Isolation of DNA sequences on human chromosome 21 by application of a recombination-based assay to DNA from flow-sorted chromosomes

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    By merging two efficient technologies, bivariate flow sorting of human metaphase chromosomes and a recombination-based assay for sequence complexity, we isolated 28 cloned DNA segments homologous to loci on human chromosome 21. Subregional mapping of these DNA segments with a somatic cell hybrid panel showed that 26 of the 28 cloned DNA sequences are distributed along the long arm of chromosome 21, while the other 2 hybridize with sequences on the short arm of both chromosome 21 and other chromosomes. This new collection of probes homologous to chromosome 21 should facilitate molecular analyses of trisomy 21 by providing DNA probes for the linkage map of chromosome 21, for studies of nondisjunction, for chromosome walking in clinically relevant subregions of chromosome 21, and for the isolation of genes on chromosome 21 following the screening of cDNA libraries.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47623/1/439_2004_Article_BF00366237.pd
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