Cooling and hemodynamic management in heatstroke: practical recommendations

INTRODUCTION:Although rapid cooling and management of circulatory failure are crucial to the prevention of irreversible tissue damage and death in heatstroke, the evidence supporting the optimal cooling method and hemodynamic management has yet to be established.METHODS:A systematic review of all clinical studies published in Medline (1966 to 2006), CINAHL (Cumulative Index to Nursing & Allied Health Literature) (1982 to 2006), and Cochrane Database was performed using the OVID interface without language restriction. Search terms included heatstroke, sunstroke, and heat stress disorders.RESULTS:Fourteen articles reported populations subjected to cooling treatment for classic or exertional heatstroke and included data on cooling time, neurologic morbidity, or mortality. Five additional articles described invasive monitoring with central venous or pulmonary artery catheters. The four clinical trials and 15 observational studies covered a total of 556 patients. A careful analysis of the results obtained indicated that the cooling method based on conduction, namely immersion in iced water, was effective among young people, military personnel, and athletes with exertional heatstroke. There was no evidence to support the superiority of any one cooling technique in classic heatstroke. The effects of non-invasive, evaporative, or conductive-based cooling techniques, singly or combined, appeared to be comparable. No evidence of a specific endpoint temperature for safe cessation of cooling was found. The circulatory alterations in heatstroke were due mostly to a form of distributive shock associated with relative or absolute hypovolemia. Myocardial failure was found to be rare.CONCLUSION:A systematic review of the literature failed to identify reliable clinical data on the optimum treatment of heatstroke. Nonetheless, the findings of this study could serve as a framework for preliminary recommendations in cooling and hemodynamic management of heatstroke until more evidence-based data are generated

Rheological Quality and Influence Factor of Moroccan Prickly Pear Juice (Opuntia ficus indica L.)

Rheological properties of prickly pear juice fruit of cactus (Opuntia ficus indica) and impacts of temperature, shearing rate and pH value on its viscosity were studied using a rotational concentric cylinders viscometer. The results show that the viscosity of prickly pear juice decreases with the increase of its temperature and shearing rate. The solution presents pseudo-plasticity fluid, which shows the characters of shear thinning as follows: first, its viscosity decreases gradually as the temperature increases. The viscosity decreases sharply at both acid and alkaline conditions, indicating that it is influenced apparently by pH value. Keywords: Prickly Pear, Juice, temperature, shearing rate, pH, Viscosity

Gender Differences in Ghrelin Association with Cardiometabolic Risk Factors in Arab Population

Ghrelin is a stomach produced hormone that has been shown to have protective role against development of CVD which is a leading cause of death in the Arab world. The objective of this study is to examine the gender difference in association between traditional CVD risk factors and plasma ghrelin among Arabs. 359 Arab residents in Kuwait participated in a cross-sectional survey (≥20 years old): 191 were females and 168 were males. Plasma level of ghrelin was assessed using Luminex-based assay. Ghrelin levels were significantly higher in females (935 ± 78 pg/mL) than males (763 ± 65 pg/mL) (P=0.0007). Females showed inverse association with WC (r=-0.23, P=0.001) and HbA1C (r=-0.19, P=0.0102) as well as SBP (r=-0.15, P=0.0383) and DBP (r=-0.16, P=0.0230), respectively. Higher levels of ghrelin were shown to associate with increased insulin resistance, as measured by HOMAIR, in male Arab subjects (P-trend = 0.0202) but not in females. In this study we show that higher ghrelin level was negatively associated with measures of obesity, HbA1C, and blood pressure in females and positively associated with increased insulin resistance in Arab males

Toll-like receptor 4 and high-mobility group box 1 are critical mediators of tissue injury and survival in a mouse model for heatstroke.

The molecular mechanisms that initiate the inflammatory response in heatstroke and their relation with tissue injury and lethality are not fully elucidated. We examined whether endogenous ligands released by damaged/stressed cells such as high-mobility group box 1 (HMGB1) signaling through Toll-like receptor 4 (TLR4) may play a pathogenic role in heatstroke. Mutant TLR4-defective (C3H/HeJ) and wild type (C3H/HeOuJ) mice were subjected to heat stress in an environmental chamber pre-warmed at 43.5 °C until their core temperature reached 42.7°C, which was taken as the onset of heatstroke. The animals were then allowed to recover passively at ambient temperature. A sham-heated group served as a control. Mutant mice displayed more histological liver damage and higher mortality compared with wild type mice (73% vs. 27%, respectively, P<0.001). Compared to wild type mice, mutant mice exhibited earlier plasma release of markers of systemic inflammation such as HMGB1 (206 ± 105 vs. 63 ± 21 ng/ml; P = 0.0018 and 209 ± 100 vs. 46 ± 32 ng/ml; P<0.0001), IL-6 (144 ± 40 vs. 46 ± 20 pg/ml; P<0.001 and 184 ± 21 vs. 84 ± 54 pg/ml; P = 0.04), and IL-1β (27 ± 4 vs. 1.7 ± 2.3 pg/ml; P<0.0001 at 1 hour). Both strains of mice displayed early release of HMGB1 into the circulation upstream of IL-1β and IL-6 responses which remained elevated up to 24 h. Specific inhibition of HMGB1 activity with DNA-binding A Box (600 µg/mouse) protected the mutant mice against the lethal effect of heat stress (60% A Box vs. 18% GST protein, P = 0.04). These findings suggest a protective role for the TLR4 in the host response to severe heat stress. They also suggest that HMGB1 is an early mediator of inflammation, tissue injury and lethality in heatstroke in the presence of defective TLR4 signaling

Gender-Specific Association of Oxidative Stress and Inflammation with Cardiovascular Risk Factors in Arab Population

Background. The impact of gender difference on the association between metabolic stress and cardiovascular disease (CVD) remains unclear. We have investigated, for the first time, the gender effect on the oxidative and inflammatory stress responses and assessed their correlation with classical cardiometabolites in Arab population. Methods. A total of 378 adult Arab participants (193 females) were enrolled in this cross-sectional study. Plasma levels of CRP, IL-6, IL-8, TNF-α, ROS, TBARs, and PON1 were measured and correlated with anthropometric and cardiometabolite parameters of the study population. Results. Compared to females, males had significantly higher FBG, HbA1c, TG, and blood pressure but lower BMI, TC, and HDL (P < 0.05). After adjustment for BMI and WC, females had higher levels of ROS, TBARS, and CRP (P < 0.001) whereas males had increased levels of IL-8, IL-6, and TNF-α (P < 0.05). Moreover, after adjustment for age, BMI, and gender, the levels of TNF-α, IL-6, and ROS were associated with central obesity but not general obesity. Conclusion. Inflammation and oxidative stress contribution to CVD risk in Arab population linked to gender and this risk is better reflected by central obesity. Arab females might be at risk of CVD complications due to increased oxidative stress

A simple and eco-friendly microwave mediated route the synthesis of novel antimicrobial substituted quinoline-2-thiones

An eco-friendly and efficient method was developed for the preparation of a new series of sulfur-containing quinolinthiones. Compounds 6a–o were synthesized from 4-methyl-2-thiocoumarin and arylhydrazides using water as a solvent under microwave irradiation. Some noteworthy features of our novel method are its cleanliness, short reaction time and high conversion rate, and the reaction proceeds (profiles) using a simple procedure. All of the prepared compounds were screened for their antibacterial efficacy in vitro using the disc diffusion method against bacterial strains. Compound (6j) showed the greatest potency with a 16 and 19 mm inhibition zone against Klebsiella pneumonia and Staphylococcus aureus, respectively