142 research outputs found
Mactinin, a fragment of cytoskeletal α-actinin, is a novel inducer of heat shock protein (Hsp)-90 mediated monocyte activation
<p>Abstract</p> <p>Background</p> <p>Monocytes, their progeny such as dendritic cells and osteoclasts and products including tumor necrosis factor (TNF)-α, interleukin (IL)-1α and IL-1β play important roles in cancer, inflammation, immune response and atherosclerosis. We previously showed that mactinin, a degradative fragment of the cytoskeletal protein α-actinin, is present at sites of monocytic activation in vivo, has chemotactic activity for monocytes and promotes monocyte/macrophage maturation. We therefore sought to determine the mechanism by which mactinin stimulates monocytes.</p> <p>Results</p> <p>Radiolabeled mactinin bound to a heterocomplex on monocytes comprised of at least 3 proteins of molecular weight 88 kD, 79 kD and 68 kD. Affinity purification, mass spectroscopy and Western immunoblotting identified heat shock protein (Hsp)-90 as the 88 kD component of this complex. Hsp90 was responsible for mediating the functional effects of mactinin on monocytes, since Hsp90 inhibitors (geldanamycin and its analogues 17-allylamino-17-demethoxygeldanamycin [17-AAG] and 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin [17-DMAG]) almost completely abrogated the stimulatory activity of mactinin on monocytes (production of the pro-inflammatory cytokines IL-1α, IL-1β and TNF-α, as well as monocyte chemotaxis).</p> <p>Conclusion</p> <p>Mactinin is a novel inducer of Hsp90 activity on monocytes and may serve to perpetuate and augment monocytic activation, thereby functioning as a "matrikine." Blockage of this function of mactinin may be useful in diseases where monocyte/macrophage activation and/or Hsp90 activity are detrimental.</p
Results from the dissemination of an evidence-based telephone-delivered intervention for healthy lifestyle and weight loss: the Optimal Health Program
Despite proven efficacy, there are few published evaluations of telephone-delivered interventions targeting physical activity, healthy eating, and weight loss in community dissemination contexts. This study aims to evaluate participant and program outcomes from the Optimal Health Program, a telephone-delivered healthy lifestyle and weight loss program provided by a primary health care organization. Dissemination study used a single-group, repeated measures design; outcomes were assessed at 6-month (mid-program; n = 166) and 12-month (end of program; n = 88) using paired analyses. The program reached a representative sample of at-risk, primary care patients, with 56 % withdrawing before program completion. Among completers, a statistically significant improvement between baseline and end of program was observed for weight [mean change (SE) −5.4 (7.0) kg] and waist circumference [−4.8 (9.7) cm], underpinned by significant physical activity and dietary change. Findings suggest that telephone-delivered weight loss and healthy lifestyle programs can provide an effective model for use in primary care settings, but participant retention remains a challenge
Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study
Peer reviewe
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is . We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between and times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1-1.4 per year during the 2018-2019 observing run and 0.3-1.7 per year at design sensitivity
Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study
Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk
'Get healthy, stay healthy': Protocol for evaluation of a lifestyle intervention delivered by text-message following the Get Healthy Information and Coaching Service®
Background: Behavioural lifestyle interventions can be effective at promoting initial weight loss and supporting physical activity and dietary behaviour change, however maintaining improvements in these outcomes is often more difficult to achieve. Extending intervention contact to reinforce learnt behavioural skills has been shown to improve maintenance of behaviour change and weight loss. This trial aims to evaluate the feasibility, acceptability and efficacy of a text message-delivered extended contact intervention to enhance or maintain change in physical activity, dietary behaviour and weight loss among participants who have completed a six month Government-funded, population-based telephone coaching lifestyle program: the Get Healthy Information and Coaching Service (GHS). Methods/Design. GHS completers will be randomised to the 6-month extended contact intervention (Get Healthy, Stay Healthy, GHSH) or a no contact control group (standard practice following GHS completion). GHSH participants determine the timing and frequency of the text messages (3-13 per fortnight) and content is tailored to their behavioural and weight goals and support preferences. Two telephone tailoring calls are made (baseline, 12-weeks) to facilitate message tailoring. Primary outcomes, anthropometric (body weight and waist circumference via self-report) and behavioural (moderate-vigorous physical activity via self-report and accelerometer, fruit and vegetable intake via self-report), will be assessed at baseline (at GHS completion), 6-months (end of extended contact intervention) and 12-months (6-months post intervention contact). Secondary aims include evaluation of: the feasibility of program delivery; the acceptability for participants; theoretically-guided, potential mediators and moderators of behaviour change; dose-responsiveness; and, costs of program delivery. Discussion. Findings from this trial will inform the delivery of the GHS in relation to the maintenance of behaviour change and weight loss, and will contribute to the broader science of text message lifestyle interventions delivered in population health settings. Trial registration. ACTRN12613000949785
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