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Objectives

To investigate whether the exercise performance benefits with neck cooling in the heat are attributable to neck-specific cooling, general body cooling, a cooler site-specific thermal perception or a combination of the above.

Design

Counter-balanced crossover design.

Methods

Twelve healthy participants cycled in the heat (34 °C, 30% relative humidity), at a power output (PO) self-selected to maintain a fixed rating of perceived exertion (RPE) of 16. Each participant underwent four experimental trials: no cooling (CON), neck cooling (NEC), abdominal cooling (ABD), or neck cooling with menthol (MEN). Participants cycled for 90 min or until their workload reduced by <70% of their initial PO. Changes in PO, rectal temperature (Tre), mean skin temperature (Tsk), whole-body thermal sensation (TSwb) and thermal sensation of the neck (TSneck) were recorded throughout.

Results

The mean reduction in PO throughout exercise was similar (p = 0.431) for CON (175 ± 10 W), NEC (176 ±12 W), ABD (172 ± 13 W) and MEN (174 ± 12 W). The ΔTre at the end of exercise was similar (p = 0.874) for CON (0.83 ± 0.5 °C), NEC (0.85 ± 0.5 °C), ABD (0.82 ± 0.5 °C) and MEN (0.81 ± 0.5 °C). TSwb was cooler (p < 0.013) in MEN (125 ± 8 mm) compared to CON (146 ± 19 mm), NEC (135 ± 11 mm) and ABD (141 ± 16 mm).

Conclusions

No differences in exercise performance or thermal strain were observed in any of the cooling trials compared to the CON trial, despite significantly cooler TSwb values in the MEN and NEC trials compared to the CON trial. These findings differ from previous observations and highlight that the benefit of neck cooling may be situation dependent.  相似文献   
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In this comprehensive evidence-based analysis of ulcerative colitis (UC), a causal role is identified for colonic epithelial hydrogen peroxide (H2O2) in both the pathogenesis and relapse of this debilitating inflammatory bowel disease. Studies have shown that H2O2 production is significantly increased in the non-inflamed colonic epithelium of individuals with UC. H2O2 is a powerful neutrophilic chemotactic agent that can diffuse through colonic epithelial cell membranes creating an interstitial chemotactic molecular “trail” that attracts adjacent intravascular neutrophils into the colonic epithelium leading to mucosal inflammation and UC. A novel therapy aimed at removing the inappropriate H2O2 mediated chemotactic signal has been highly effective in achieving complete histologic resolution of colitis in patients experiencing refractory disease with at least one (biopsy-proven) histologic remission lasting 14 years to date. The evidence implies that therapeutic intervention to prevent the re-establishment of a pathologic H2O2 mediated chemotactic signaling gradient will indefinitely preclude neutrophilic migration into the colonic epithelium constituting a functional cure for this disease. Cumulative data indicate that individuals with UC have normal immune systems and current treatment guidelines calling for the suppression of the immune response based on the belief that UC is caused by an underlying immune dysfunction are not supported by the evidence and may cause serious adverse effects. It is the aim of this paper to present experimental and clinical evidence that identifies H2O2 produced by the colonic epithelium as the causal agent in the pathogenesis of UC. A detailed explanation of a novel therapeutic intervention to normalize colonic H2O2, its rationale, components, and formulation is also provided.  相似文献   
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Gluteus minimus disorders are a potential source of greater trochanteric or anterior hip pain. Disorders of the gluteus minimus tendon most commonly occur in conjunction with gluteus medius tendon abnormalities but can also occur in isolation. Understanding the sonoanatomy of the gluteus minimus muscle-tendon unit is a prerequisite for recognizing and characterizing gluteus minimus tendon disorders, which, in turn, guides treatment for patients with greater trochanteric or anterior hip pain syndromes.  相似文献   
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The advent of direct-acting antivirals (DAAs) has provided the impetus to transplant kidneys from hepatitis C virus-positive donors into uninfected recipients (D+/R−). Thirty D+/R− patients received DAA treatment. Sustained virologic response (SVR12) was defined as an undetectable viral load in 12 weeks after treatment. An age-matched cohort of uninfected donor and recipient pairs (D−/R−) transplanted during same time period was used for comparison. The median day of viral detection was postoperative day (POD) 2. The detection of viremia in D+/R− patients was 100%. The initial median viral load was 531 copies/μL (range: 10-1 × 108 copies/μL) with a median peak viral load of 3.4 × 105 copies/μL (range: 804-1.0 × 108 copies/μL). DAAs were initiated on median POD 9 (range: 5-41 days). All 30 patients had confirmed SVR12. During a median follow-up of 10 months, patient and graft survival was 100%, and acute rejection was 6.6% with no major adverse events related to DAA treatment. Delayed graft function was significantly decreased in D+/R− patients as compared to the age-matched cohort (27% vs 60%; P = .01). D+/R− transplantation offers patients an alternative strategy to increase access.  相似文献   
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