Analysis of the Mechanisms of Heat Acclimatization : Comparison of Heat-tolerance between Japanese and Thai Subjects

In order to clarify the mechanisms of heat acclimatization to tropical climates by permanent residence, changes in oral temperature due to heat load were compared in 10 male subjects in Chiang Mai, Thailand (tropical region) and 10 male subjects in Nagasaki, Japan (temperate region). Mean annual ambient temperature is 16.6℃ in Nagasaki and 25.9℃ in Chiang Mai. The experiments for the Thai subjects were performed in Chiang Mai and those for the Japanese subjects in Nagasaki during each region\u27s hottest months. The constitutional characteristics of the Thai subjects were a little shorter and slightly leaner than the Japanese. After staying at rest in the experimental room at 32℃ and 35% of relative humidity for at least 30 min, the lower legs were immersed into a hot water bath of 43℃ for 30 min. Mean initial oral temperature was 37.06±0.07℃ in Japanese and 37.12±0.05℃ in Thai subjects (P>0.05). Oral temperature rose after heat load and reached to 37.54±0.06℃ and 37.59±0.06℃ in Japanese and Thai subjects (P>0.05), respectively. Although the inhabitants in Chiang Mai were expected to be more acclimatized to heat compared to those in Nagasaki, no significant difference in the oral temperature was found between two groups throughout the experiment. It is speculated that the same rise in oral temperature in both groups of subjects is attributed to a lower sweat rate and an increase of dry heat loss in Thai subjects. In future studies, not only core temperature but also skin temperatures (dry heat loss) and sweat rate (evaporative heat loss) should be measured and analyzed

Seasonal Variation of Thermal Sweating

Although seasonal change in sweat response; the higher sweat rate, the shorter latent period for sweating, and the lower salt concentration in sweat in summer than in winter has been reported, the findings have hardly been led by accurate methods of measuring sweat rate. In order to confirm seasonal variation of sweating, sweat tests were carried out in summer and in winter for each subject. Local sweat rate was recorded before, during and after heat load by using capacitance hygrometer-sweat capture capsule method, which enabled the determination of local sweat rate highly sensitively and continuously. Sweat-onset time and local sweat volume were compared between both seasons. Sweat-onset time was 10.82±1.21 min (chest), 11.85±1.26 min (abdomen) in summer. It was 16.33±1.95 min (chest), 16.42±1.91 min (abdomen) in winter, P<0.005 (chest) and P<0.05 (abdomen) between both seasons. Local sweat volume was 121.23±20.90 mg/capsule (chest), 48.46±10.83 mg/capsule (abdomen) in summer. It was 36.59±10.83 mg/capsule (chest), 19.20±5.88 mg/capsule (abdomen) in winter, P<0.01 (chest) and P<0.05 (abdomen) between both seasons. Seasonal variation of thermal sweating was reconfirmed by the more accurate method in this study. Furthermore, no changes in threshold for sweating in oral temperature was observed. It is suggested that the mechanism of seasonal acclimatization is different from that of artificial heat acclimation

Comparison of Allogeneic vs Autologous Bone Marrow–Derived Mesenchymal Stem Cells Delivered by Transendocardial Injection in Patients With Ischemic Cardiomyopathy

Noticias recopiladas y seleccionadas del Centro de Noticias de las Naciones Unidas período diciembre 2017-junio 2018.Departamento de Derechos Humanos y Derecho Internacional Humanitario.Instituto de Relaciones Internacionale

Comparison of Allogeneic vs Autologous Bone Marrow–Derived Mesenchymal Stem Cells Delivered by Transendocardial Injection in Patients With Ischemic Cardiomyopathy

CONTEXT: Mesenchymal stem cells (MSCs) are under evaluation as a therapy for ischemic cardiomyopathy (ICM). Both autologous and allogeneic MSC therapies are possible; however, their safety and efficacy have not been compared. OBJECTIVE: To test whether allogeneic MSCs are as safe and effective as autologous MSCs in patients with left ventricular (LV) dysfunction due to ICM. DESIGN, SETTING, AND PATIENTS: A phase 1/2 randomized comparison (POSEIDON study) in a US tertiary-care referral hospital of allogeneic and autologous MSCs in 30 patients with LV dysfunction due to ICM between April 2, 2010, and September 14, 2011, with 13-month follow-up. INTERVENTION: Twenty million, 100 million, or 200 million cells (5 patients in each cell type per dose level) were delivered by transendocardial stem cell injection into 10 LV sites. MAIN OUTCOME MEASURES: Thirty-day postcatheterization incidence of predefined treatment-emergent serious adverse events (SAEs). Efficacy assessments included 6-minute walk test, exercise peak [Formula: see text] , Minnesota Living with Heart Failure Questionnaire (MLHFQ), New York Heart Association class, LV volumes, ejection fraction (EF), early enhancement defect (EED; infarct size), and sphericity index. RESULTS: Within 30 days, 1 patient in each group (treatment-emergent SAE rate, 6.7%) was hospitalized for heart failure, less than the prespecified stopping event rate of 25%. The 1-year incidence of SAEs was 33.3% (n=5) in the allogeneic group and 53.3% (n=8) in the autologous group (P=.46). At 1 year, there were no ventricular arrhythmia SAEs observed among allogeneic recipients compared with 4 patients (26.7%) in the autologous group (P=.10). Relative to baseline, autologous but not allogeneic MSC therapy was associated with an improvement in the 6-minute walk test and the MLHFQ score, but neither improved exercise [Formula: see text] max. Allogeneic and autologous MSCs reduced mean EED by −33.21% (95% CI, −43.61% to −22.81%; P<.001) and sphericity index but did not increase EF. Allogeneic MSCs reduced LV end-diastolic volumes. Low-dose concentration MSCs (20 million cells) produced greatest reductions in LV volumes and increased EF. Allogeneic MSCs did not stimulate significant donor-specific alloimmune reactions. CONCLUSIONS: In this early-stage study of patients with ICM, transendocardial injection of allogeneic and autologous MSCs without a placebo control were both associated with low rates of treatment-emergent SAEs, including immunologic reactions. In aggregate, MSC injection favorably affected patient functional capacity, quality of life, and ventricular remodeling. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT0108799