Mixing ratios of volatile organic compounds (VOCs) in the atmosphere of Karachi, Pakistan

Mixing ratios of carbon monoxide (CO), methane (CH4), non-methane hydrocarbons, halocarbons and alkyl nitrates (a total of 72 species) were determined for 78 whole air samples collected during the winter of 1998-1999 in Karachi, Pakistan. This is the first time that volatile organic compound (VOC) levels in Karachi have been extensively characterized. The overall air quality of the urban environment was determined using air samples collected at six locations throughout Karachi. Methane (6.3ppmv) and ethane (93ppbv) levels in Karachi were found to be much higher than in other cities that have been studied. The very high CH4 levels highlight the importance of natural gas leakage in Karachi. The leakage of liquefied petroleum gas contributes to elevated propane and butane levels in Karachi, although the propane and butane burdens were lower than in other cities (e.g., Mexico City, Santiago). High levels of benzene (0.3-19ppbv) also appear to be of concern in the Karachi urban area. Vehicular emissions were characterized using air samples collected along the busiest thoroughfare of the city (M.A. Jinnah Road). Emissions from vehicular exhaust were found to be the main source of many of the hydrocarbons reported here. Significant levels of isoprene (1.2ppbv) were detected at the roadside, and vehicular exhaust is estimated to account for about 20% of the isoprene observed in Karachi. 1,2-Dichloroethane, a lead scavenger added to leaded fuel, was also emitted by cars. The photochemical production of ozone (O3) was calculated for CO and the various VOCs using the Maximum Incremental Reactivity (MIR) scale. Based on the MIR scale, the leading contributors to O3 production in Karachi are ethene, CO, propene, m-xylene and toluene. © 2002 Elsevier Science Ltd. All rights reserved

Averting Behavior Framework for Perceived Risk of Yersinia enterocolitica Infections

The focus of this research is to present a theoretical model of averting actions that households take to avoid exposure to Yersinia enterocolitica in contaminated food. The cost of illness approach only takes into account the value of a cure, while the averting behavior approach can estimate the value of preventing the illness. The household, rather than the individual, is the unit of analysis in this model, where one household member is primarily responsible for procuring uncontaminated food for their family. Since children are particularly susceptible and live with parents who are primary decision makers for sustenance, the designated household head makes the choices that are investigated in this paper. This model uses constrained optimization to characterize activities that may offer protection from exposure to Yersinia enterocolitica contaminated food. A representative household decision maker is assumed to allocate family resources to maximize utility of an altruistic parent, an assumption used in most research involving economics of the family

Prevention and management of secondary central nervous system lymphoma

Secondary central nervous system (CNS) lymphoma (SCNSL) is defined by the involvement of the CNS, either at the time of initial diagnosis of systemic lymphoma or in the setting of relapse, and can be either isolated or with synchronous systemic disease. The risk of CNS involvement in patients with diffuse large B-cell lymphoma is approximately 5%; however, certain clinical and biological features have been associated with a risk of up to 15%. There has been growing interest in improving the definition of patients at increased risk of CNS relapse, as well as identifying effective prophylactic strategies to prevent it. SCNSL often occurs within months of the initial diagnosis of lymphoma, suggesting the presence of occult disease at diagnosis in many cases. The differing presentations of SCNSL create the therapeutic challenge of controlling both the systemic disease and the CNS disease, which uniquely requires agents that penetrate the blood-brain barrier. Outcomes are generally poor with a median overall survival of approximately 6 months in retrospective series, particularly in those patients presenting with SCNSL after prior therapy. Prospective studies of intensive chemotherapy regimens containing high-dose methotrexate, followed by hematopoietic stem cell transplantation have shown the most favorable outcomes, especially for patients receiving thiotepa-based conditioning regimens. However, a proportion of patients will not respond to induction therapies or will subsequently relapse, indicating the need for more effective treatment strategies. In this review we focus on the identification of high-risk patients, prophylactic strategies and recent treatment approaches for SCNSL. The incorporation of novel agents in immunochemotherapy deserves further study in prospective trials

Staphylococcus aureus septicemia presenting as disseminated intravascular coagulation - thrombotic thrombocytopenic purpura overlap and thrombus in inferior vena cava, right atrium and right ventricle: a case report

Staphylococcal sepsis following furunculosis and complicated by suspected deep vein thrombosis and septic inferior vena caval, right atrium, right ventricle emboli accompanied by disseminated intravascular coagulation (DIC) - thrombotic thrombocytopenic overlap in a 65 years old lady is presented. She was managed successfully with antibiotics and anticoagulation. The case is reported for its rarity and brings to light the vivid manifestations of septicemia specially staphylococcal

Correlation of non alcoholic fatty liver disease in patients of coronary artery disease

Background: In NAFLD, increase in factor VIII and a reduction of protein C leads to the progression from steatosis to cirrhosi. The aim was to study the correlation of NAFLD with other associated risk factors of CAD.Methods: A total number of 100 patients of coronary artery disease were assessed for presence of NAFLD, dyslipidemia, metabolic syndrome & diabetes by various laboratory tests.Results: 46% of the CAD patients were found to have NAFLD. 69.6% patients of NAFLD were in the age group of 40-60 years. 21.7% were above 60 years. 91.1% of NAFLD patients were males. Half of the NAFLD patients were diabetic. 21.7% of NAFLD patients were found to have a total cholesterol level >200. Triglyceride level was also high among these patients (58.7%). All the NAFLD patients had LDL <100. 52.2% of them had metabolic syndrome.Conclusions: The study showed a direct correlation between NAFLD & CAD. Metabolic syndrome, diabetes, increased total cholesterol & triglyceride level were also associated with increased risk for CAD. However LDL level was not found to be associated with NAFLD risk

Atrial fibrillation associated with high voltage electric shock in a young healthy female: a case report

Atrial fibrillation is amongst the various arrhythmias resulting after electrical injury but its incidence has been reported to be extremely rare. Here we are reporting a case of 35 years old lady presenting to our Emergency department with atrial fibrillation with fast ventricular rate after accidentally being injured by high voltage electrical current. She was managed successfully with pharmacological cardioversion followed by a period of observation. The rhythm reverted back to normal sinus rhythm on 3rd day. This approach of management is amongst one of the few published cases where patient was managed conservatively

Air quality in Mecca and surrounding holy places in Saudi Arabia during Hajj: initial survey.

The Arabian Peninsula experiences severe air pollution, the extent and sources of which are poorly documented. Each year in Saudi Arabia this situation is intensified during Hajj, the Holy Pilgrimage of Islam that draws millions of pilgrims to Mecca. An initial study of air quality in Mecca and surrounding holy sites during the 2012 Hajj (October 24-27) revealed strongly elevated levels of the combustion tracer carbon monoxide (CO, up to 57 ppmv) and volatile organic compounds (VOCs) along the pilgrimage route-especially in the tunnels of Mecca-that are a concern for human health. The most abundant VOC was the gasoline evaporation tracer i-pentane, which exceeded 1200 ppbv in the tunnels. Even though VOC concentrations were generally lower during a follow-up non-Hajj sampling period (April 2013), many were still comparable to other large cities suffering from poor air quality. Major VOC sources during the 2012 Hajj study included vehicular exhaust, gasoline evaporation, liquefied petroleum gas, and air conditioners. Of the measured compounds, reactive alkenes and CO showed the strongest potential to form ground-level ozone. Because the number of pilgrims is expected to increase in the future, we present emission reduction strategies to target both combustive and evaporative fossil fuel sources