Characteristics and Outcomes of Traumatic Cardiac Arrests in the Pan-Asian Resuscitation Outcomes Study.

OBJECTIVE: Little is known about survival outcomes after traumatic cardiac arrest in Asia, or the association of Utstein factors with survival after traumatic cardiac arrests. This study aimed to describe the epidemiology and outcomes of traumatic cardiac arrests in Asia, and analyze Utstein factors associated with survival. METHODS: Traumatic cardiac arrest patients from 13 countries in the Pan-Asian Resuscitation Outcomes Study registry from 2009 to 2018 were analyzed. Multilevel logistic regression was performed to identify factors associated with the primary outcomes of survival to hospital discharge and favorable neurological outcome (Cerebral Performance Category (CPC) 1-2), and the secondary outcome of return of spontaneous circulation (ROSC). RESULTS: There were 207,455 out-of-hospital cardiac arrest cases, of which 13,631 (6.6%) were trauma patients aged 18 years and above with resuscitation attempted and who had survival outcomes reported. The median age was 57 years (interquartile range 39-73), 23.0% received bystander cardiopulmonary resuscitation (CPR), 1750 (12.8%) had ROSC, 461 (3.4%) survived to discharge, and 131 (1.0%) had CPC 1-2. Factors associated with higher rates of survival to discharge and favorable neurological outcome were arrests witnessed by emergency medical services or private ambulances (survival to discharge adjusted odds ratio (aOR) = 2.95, 95% confidence interval (CI) = 1.99-4.38; CPC 1-2 aOR = 2.57, 95% CI = 1.25-5.27), bystander CPR (survival to discharge aOR = 2.16; 95% CI 1.71-2.72; CPC 1-2 aOR = 4.98, 95% CI = 3.27-7.57), and initial shockable rhythm (survival to discharge aOR = 12.00; 95% CI = 6.80-21.17; CPC 1-2 aOR = 33.28, 95% CI = 11.39-97.23) or initial pulseless electrical activity (survival to discharge aOR = 3.98; 95% CI = 2.99-5.30; CPC 1-2 aOR = 5.67, 95% CI = 3.05-10.53) relative to asystole. CONCLUSIONS: In traumatic cardiac arrest, early aggressive resuscitation may not be futile and bystander CPR may improve outcomes.

A physiologically-based pharmacokinetic model assessment of methyl t-butyl ether in groundwater for a bathing and showering determination.

Methyl t-butyl ether (MTBE) is a gasoline additive that has appeared in private wells as a result of leaking underground storage tanks. Neurological symptoms (headache, dizziness) have been reported from household use of MTBE-affected water, consistent with animal studies showing acute CNS depression from MTBE exposure. The current research evaluates acute CNS effects during bathing/showering by application of physiologically-based pharmacokinetic (PBPK) techniques to compare internal doses in animal toxicity studies to human exposure scenarios. An additional reference point was the delivered dose associated with the acute Minimum Risk Level (MRL) for MTBE established by the Agency for Toxic Substances and Disease Registry. A PBPK model for MTBE and its principal metabolite, t-butyl alcohol (TBA) was developed and validated against published data in rats and humans. PBPK analysis of animal studies showed that acute CNS toxicity after MTBE exposure can be attributed principally to the parent compound since the metabolite (TBA) internal dose was below that needed for CNS effects. The PBPK model was combined with an exposure model for bathing and showering which integrates inhalation and dermal exposures. This modeling indicated that bathing or showering in water containing MTBE at 1 mg/L would produce brain concentrations approximately 1000-fold below the animal effects level and twofold below brain concentrations associated with the acute MRL. These findings indicate that MTBE water concentrations of 1 mg/L or below are unlikely to trigger acute CNS effects during bathing and showering. However, MTBE's strong odor may be a secondary but deciding factor regarding the suitability of such water for domestic uses.

A physiologically based pharmacokinetic model for fluoride uptake by bone.

A sex-specific, physiologically based pharmacokinetic (pbpk) model has been developed to describe the absorption, distribution, and elimination of fluorides in rats and humans. Growth curves generated by plotting mean body weights (kg) against age (weeks or years) are included in the simulation model to allow the integration of chronic fluoride exposure from birth to old age. The model incorporates age and body weight dependence of the physiological processes that control the uptake of fluoride by bone and the elimination of fluoride by the kidneys. Six compartments make up the model. These are lung, liver, kidney, bone, and slowly and rapidly perfused compartments. The model also includes two bone subcompartments: a small, flow-limited, rapidly exchangeable surface bone compartment and a bulk virtually nonexchangeable inner bone compartment. The inner bone compartment contains nearly all of the whole body content of fluoride, which, in the longer time frame, may be mobilized through the process of bone modeling and remodeling. The model has been validated by comparing the model predictions with experimental data gathered in rats and humans after drinking water and dietary ingestion of fluoride. This physiological model description of absorption, distribution, and elimination of fluoride from the body permits the analysis of the combined effect of ingesting and inhaling fluorides on the target organ, bone. Estimates of fluoride concentrations in bone are calculated and related to chronic fluoride toxicity. The model is thus useful for predicting some of the long-term metabolic features and tissue concentrations of fluoride that may be of value in understanding positive or negative effects of fluoride on human health. In addition, the pbpk model provides a basis for across-species extrapolation of the effective fluoride dose at the target tissue, bone, in the assessment of risk from different exposure conditions.

A physiologically based pharmacokinetic assessment of tetrachloroethylene in groundwater for a bathing and showering determination.

A two-step methodology is described to make a health-based determination for the bathing and showering use of the water from a private well contaminated with volatile organic chemicals. The chemical perchloroethylene (PERC) is utilized to illustrate the approach. First, a chemical-specific exposure model is used to predict the concentration of PERC in the shower air, shower water, and in the air above the bathtub. Second, a physiologically based pharmacokinetic (PBPK) model is used to predict the concentration of PERC delivered to the target tissue, the brain, since the focus is on neurological endpoints. The simulation exercise includes concurrent dermal and inhalation routes of exposure. A reference target tissue level (RTTL) in the brain is estimated using the PBPK model. A hazard index based on this benchmark guideline is used to make a regulatory determination for bathing and showering use of the contaminated water.

Free amino acids in seminal fluid & haemolymph of Cimex lectularious L. & their possible role in sperm metabolism.

PIP: Previously it was shown that glucose and trehalose are present in the hemolymph of Cimex lectularious L. and that the active bed bug sperm can utilize these sugars oxidatively. A study was conducted on the occurrence of amino acids in the seminal fluid and the hemolymph of the bed bug and the enzymes of Cimex sperm concerned with amino acid metabolism. It was determined that the hemolymph contains 12 free amino acids and in the seminal fluid, there are 8. In the Cimex sperm, transaminase activity is limited, with L-alanine the only amino acid involved in transamination. Although it is understood that amino acids constitute a very limited source of energy to the bed bug sperm! an oxidative deamination of L-alanine may occur, since oxygen is available to the sperm and alanine and glutamic acid are present in the seminal fluid and hemolymph.^ieng