486 research outputs found
Seagrass can mitigate negative ocean acidification effects on calcifying algae
The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.E.B. would like to thank the Coordenação de Aperfeiçoamento de Pessoas de Nível Superior (CAPES) for Masters
funding. Funding for this project came from the Synergism grant (CNPq 407365/2013-3). We extend our thanks
to the Brazil-based Projeto Coral Vivo and its sponsor PetroBras Ambiental for providing the Marine Mesocosm
structure and experimental assistance.info:eu-repo/semantics/publishedVersio
Poly I:C enhances cycloheximide-induced apoptosis of tumor cells through TLR3 pathway
<p>Abstract</p> <p>Background</p> <p>Toll-like receptor 3 (TLR3) is a critical component of the innate immune response to dsRNA viruses, which was considered to be mainly expressed in immune cells and some endothelial cells. In this study, we investigated the expression and proapoptotic activity of TLR3 in human and murine tumor cell lines.</p> <p>Methods</p> <p>RT-PCR and FACS analysis were used to detect expression of TLR3 in various human and murine tumor cell lines. All tumor cell lines were cultured with poly I:C, CHX, or both for 12 h, 24 h, 72 h, and then the cell viability was analyzed with CellTiter 96<sup>® </sup>AQueous One Solution, the apoptosis was measured by FACS with Annexin V and PI staining. Production of Type I IFN in poly I:C/CHX mediated apoptosis were detected through western blotting. TLR3 antibodies and IFN-β antibodies were used in Blockade and Neutralization Assay.</p> <p>Results</p> <p>We show that TLR3 are widely expressed on human and murine tumor cell lines, and activation of TLR3 signaling in cancerous cells by poly I:C made Hela cells (human cervical cancer) and MCA38 cells (murine colon cancer) become dose-dependently sensitive to protein synthesis inhibitor cycloheximide (CHX)-induced apoptosis. Blockade of TLR3 recognition with anti-TLR3 antibody greatly attenuated the proapoptotic effects of poly I:C on tumor cells cultured with CHX. IFN-β production was induced after poly I:C/CHX treatment and neutralization of IFN-β slightly reduced poly I:C/CHX -induced apoptosis.</p> <p>Conclusion</p> <p>Our study demonstrated the proapoptotic activity of TLR3 expressed by various tumor cells, which may open a new range of clinical applications for TLR3 agonists as an adjuvant of certain cancer chemotherapy.</p
Cardiovascular comorbidities among public health clinic patients with diabetes: the Urban Diabetics Study
BACKGROUND: We sought to determine the frequency and distribution of cardiovascular comorbidities in a large cohort of low-income patients with diabetes who had received primary care for diabetes at municipal health clinics. METHODS: Outpatient data from the Philadelphia Health Care Centers was linked with hospital discharge data from all Pennsylvania hospitals and death certificates. RESULTS: Among 10,095 primary care patients with diabetes, with a mean observation period of 4.6 years (2.8 after diabetes diagnosis), 2,693 (14.3%) were diagnosed with heart disease, including 270 (1.4%) with myocardial infarction and 912 (4.8%) with congestive heart failure. Cerebrovascular disease was diagnosed in 588 patients (3.1%). Over 77% of diabetic patients were diagnosed with hypertension. Incidence rates of new complications ranged from 0.6 per 100 person years for myocardial infarction to 26.5 per 100 person years for hypertension. Non-Hispanic whites had higher rates of myocardial infarction, and Hispanics and Asians had fewer comorbid conditions than African Americans and non-Hispanic whites. CONCLUSION: Cardiovascular comorbidities were common both before and after diabetes diagnosis in this low-income cohort, but not substantially different from mixed-income managed care populations, perhaps as a consequence of access to primary care and pharmacy services
Stress and psychological factors before a migraine attack: A time-based analysis
<p>Abstract</p> <p>Background</p> <p>The objective of this study is to examine the stress and mood changes of Japanese subjects over the 1–3 days before a migraine headache.</p> <p>Methods</p> <p>The study participants were 16 patients with migraines who consented to participate in this study. Each subject kept a headache diary four times a day for two weeks. They evaluated the number of stressful events, daily hassles, domestic and non-domestic stress, anxiety, depressive tendency and irritability by visual analog scales. The days were classified into migraine days, pre-migraine days, buffer days and control days based on the intensity of the headaches and accompanying symptoms, and a comparative study was conducted for each factor on the migraine days, pre-migraine days and control days.</p> <p>Results</p> <p>The stressful event value of pre-migraine days showed no significant difference compared to other days. The daily hassle value of pre-migraine days was the highest and was significantly higher than that of buffer days. In non-domestic stress, values on migraine days were significantly higher than on other days, and there was no significant difference between pre-migraine days and buffer days or between pre-migraine days and control days. There was no significant difference in the values of domestic stress between the categories. In non-domestic stress, values on migraine days were significantly higher than other days, and there was no significant difference between pre-migraine days and buffer days or between pre-migraine days and control days.</p> <p>There was little difference in sleep quality on migraine and pre-migraine days, but other psychological factors were higher on migraine days than on pre-migraine days.</p> <p>Conclusion</p> <p>Psychosocial stress preceding the onset of migraines by several days was suggested to play an important role in the occurrence of migraines. However, stress 2–3 days before a migraine attack was not so high as it has been reported to be in the United States and Europe. There was no significant difference in the values of psychological factors between pre-migraine days and other days.</p
Acquiring a pet dog significantly reduces stress of primary carers for children with autism spectrum disorder: a prospective case control study
This study describes the impact of pet dogs on stress of primary carers of children with Autism Spectrum Disorder (ASD). Stress levels of 38 primary carers acquiring a dog and 24 controls not acquiring a dog were sampled at: Pre-intervention (17 weeks before acquiring a dog), post-intervention (3–10 weeks after acquisition) and follow-up (25–40 weeks after acquisition), using the Parenting Stress Index. Analysis revealed significant improvements in the intervention compared to the control group for Total Stress, Parental Distress and Difficult Child. A significant number of parents in the intervention group moved from clinically high to normal levels of Parental Distress. The results highlight the potential of pet dogs to reduce stress in primary carers of children with an ASD
The Human TPR Protein TTC4 Is a Putative Hsp90 Co-Chaperone Which Interacts with CDC6 and Shows Alterations in Transformed Cells
BACKGROUND: The human TTC4 protein is a TPR (tetratricopeptide repeat) motif-containing protein. The gene was originally identified as being localized in a genomic region linked to breast cancer and subsequent studies on melanoma cell lines revealed point mutations in the TTC4 protein that may be associated with the progression of malignant melanoma.
METHODOLOGY/PRINCIPLE FINDINGS: Here we show that TTC4 is a nucleoplasmic protein which interacts with HSP90 and HSP70, and also with the replication protein CDC6. It has significant structural and functional similarities with a previously characterised Drosophila protein Dpit47. We show that TTC4 protein levels are raised in malignant melanoma cell lines compared to melanocytes. We also see increased TTC4 expression in a variety of tumour lines derived from other tissues. In addition we show that TTC4 proteins bearing some of the mutations previously identified from patient samples lose their interaction with the CDC6 protein.
CONCLUSIONS/SIGNIFICANCE: Based on these results and our previous work with the Drosophila Dpit47 protein we suggest that TTC4 is an HSP90 co-chaperone protein which forms a link between HSP90 chaperone activity and DNA replication. We further suggest that the loss of the interaction with CDC6 or with additional client proteins could provide one route through which TTC4 could influence malignant development of cells
Faecal pharmacokinetics of orally administered vancomycin in patients with suspected Clostridium difficile infection
<p>Abstract</p> <p>Background</p> <p>Oral vancomycin (125 mg qid) is recommended as treatment of severe <it>Clostridium difficile </it>infection (CDI). Higher doses (250 or 500 mg qid) are sometimes recommended for patients with very severe CDI, without supporting clinical evidence. We wished to determine to what extent faecal levels of vancomycin vary according to diarrhoea severity and dosage, and whether it is rational to administer high-dose vancomycin to selected patients.</p> <p>Methods</p> <p>We recruited hospitalized adults suspected to have CDI for whom oral vancomycin (125, 250 or 500 mg qid) had been initiated. Faeces were collected up to 3 times/day and levels were measured with the AxSYM fluorescence polarization immunoassay.</p> <p>Results</p> <p>Fifteen patients (9 with confirmed CDI) were treated with oral vancomycin. Patients with ≥4 stools daily presented lower faecal vancomycin levels than those with a lower frequency. Higher doses of oral vancomycin (250 mg or 500 mg qid) led to consistently higher faecal levels (> 2000 mg/L), which were 3 orders of magnitude higher than the MIC<sub>90 </sub>of vancomycin against <it>C. difficile</it>. One patient receiving 125 mg qid had levels below 50 mg/L during the first day of treatment.</p> <p>Conclusions</p> <p>Faecal levels of vancomycin are proportional to the dosage administered and, even in patients with increased stool frequency, much higher than the MIC<sub>90</sub>. Patients given the standard 125 mg qid dosage might have low faecal levels during the first day of treatment. A loading dose of 250 mg or 500 mg qid during the first 24-48 hours followed by the standard dosage should be evaluated in larger studies, since it might be less disruptive to the colonic flora and save unnecessary costs.</p
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
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