A Review of Scientific Literature Examining the Mining History,Geology, Mineralogy,and Amphibole Asbestos Health Effects of the Rainy Creek Igneous Complex,Libby, Montana,USA

This article reviews the past 90 yr of scientific research directed on multiple aspects of the unique geology and environmental health issues surrounding the vermiculite deposit found at Libby, MT. Hydrothermal alteration and extensive weathering of the ultramafic units resulted in the formation of a rich deposit of vermiculite that was mined for 67 yr and used in numerous consumer products in its expanded form. Later intrusions of alkaline units caused hydrothermal alteration of the pyroxenes, resulting in formation of amphiboles. Some of these amphiboles occur in the asbestiform habit and have been associated with pulmonary disease in former miners and mill workers. Identification of these amphibole asbestos minerals has received little attention in the past, but recent work shows that the majority of the amphibole mineral species present may not be any of the amphibole species currently regulated by government agencies. Epidemiological studies on former miners have, nevertheless, shown that the amphibole asbestos from the Rainy Creek igneous complex is harmful; also, a recent study by the Agency for Toxic Substances and Disease Registry shows that residents of Libby who had not been employed in the vermiculite mining or milling operations also appear to have developed asbestos-related pulmonary diseases at a higher rate than the general public elsewhere. Since November 1999, the U.S. Environmental Protection Agency has been involved in the cleanup of asbestos-contaminated sites in and around Libby associated with the mining and processing of vermiculite.     

A comparative study of short‐ and long‐TE 1H MRS at 3 T for in vivo detection of 2‐hydroxyglutarate in brain tumors

2‐Hydroxyglutarate (2HG) is produced in gliomas with mutations of isocitrate dehydrogenase (IDH) 1 and 2. The ¹H resonances of the J‐coupled spins of 2HG are extensively overlapped with signals from other metabolites. Here, we report a comparative study at 3 T of the utility of the point‐resolved spectroscopy sequence with a standard short TE (35 ms) and a long TE (97 ms), which had been theoretically designed for the detection of the 2HG 2.25‐ppm resonance. The performance of the methods is evaluated using data from phantoms, seven healthy volunteers and 22 subjects with IDH‐mutated gliomas. The results indicate that TE = 97 ms provides higher detectability of 2HG than TE = 35 ms, and that this improved capability is gained when data are analyzed with basis spectra that include the effects of the volume localizing radiofrequency and gradient pulses. Copyright © 2013 John Wiley & Sons, Ltd.     

Socioeconomic Status Is Associated with Provision of Bystander Cardiopulmonary Resuscitation

Objective. Although socioeconomic status (SES) has been linked to multiple health outcomes, there have been few studies of the effect of SES on the provision of bystander cardiopulmonary resuscitation (CPR) during cardiac arrest events and no studies that we know of on the effect of SES on the provision of dispatcher-assisted bystander CPR. This study sought to define the relationship between SES and the provision of bystander CPR in an emergency medical system that includes dispatcher-provided CPR instructions. Methods. This study was a retrospective, cohort analysis of cardiac arrests due to cardiac causes occurring in private residences in King County, Washington, from January 1, 1999, to December 31, 2005. We used the tax-assessed value of the location of the cardiac arrest as an estimate of the SES of potential bystanders as well as multiple measures from 2000 Census data (education, employment, median household income, and race/ethnicity). We also examined the effect of patient and system characteristics that may affect the provision of bystander CPR. Logistic regression models were used to analyze the association of these factors with two outcomes: the provision of bystander CPR with and without dispatcher assistance. Results. Forty-four percent (1,151/2,618) of cardiac arrest victims received bystander CPR. Four hundred fifty-seven people (17.5% of the entire study population, 39.7% of those who received any bystander CPR) received CPR without telephone instructions. A total of 694 people received dispatcher-assisted bystander CPR (25.6% of the entire population, 60.4% of those receiving any bystander CPR). After adjusting for demographic and care factors, we found a strong association between the tax-assessed value of the cardiac arrest location and increased odds of the provision of bystander CPR without dispatcher instructions and bystander CPR with dispatcher assistance compared with no bystander CPR. Conclusions. This study suggests that higher bystander SES is associated with increased rates of bystander CPR with and without dispatcher instructions. CPR training programs that target lower-SES communities and assessment of these training methods may be warranted.     

Metabolism of [U‐13C]glucose in human brain tumors in vivo

Glioblastomas and brain metastases demonstrate avid uptake of 2‐[¹⁸F]fluoro‐2‐deoxyglucose by positron emission tomography and display perturbations of intracellular metabolite pools by ¹H MRS. These observations suggest that metabolic reprogramming contributes to brain tumor growth in vivo. The Warburg effect, excess metabolism of glucose to lactate in the presence of oxygen, is a hallmark of cancer cells in culture. 2‐[¹⁸F]Fluoro‐2‐deoxyglucose‐positive tumors are assumed to metabolize glucose in a similar manner, with high rates of lactate formation relative to mitochondrial glucose oxidation, but few studies have specifically examined the metabolic fates of glucose in vivo. In particular, the capacity of human brain cancers to oxidize glucose in the tricarboxylic acid cycle is unknown. Here, we studied the metabolism of human brain tumors in situ. [U‐¹³ C]Glucose (uniformly labeled glucose, i.e. d ‐glucose labeled with ¹³ C in all six carbons) was infused during surgical resection, and tumor samples were subsequently subjected to ¹³C NMR spectroscopy. The analysis of tumor metabolites revealed lactate production, as expected. We also determined that pyruvate dehydrogenase, turnover of the tricarboxylic acid cycle, anaplerosis and de novo glutamine and glycine synthesis contributed significantly to the ultimate disposition of glucose carbon. Surprisingly, less than 50% of the acetyl‐coenzyme A pool was derived from blood‐borne glucose, suggesting that additional substrates contribute to tumor bioenergetics. This study illustrates a convenient approach that capitalizes on the high information content of ¹³C NMR spectroscopy and enables the analysis of intermediary metabolism in diverse cancers growing in their native microenvironment. Copyright © 2012 John Wiley & Sons, Ltd.     

Improving the prevention and management of chronic disease in low-income and middle-income countries: a priority for primary health care

The burden of chronic diseases, such as heart disease, cancer, diabetes, and mental disorders is high in low-income and middle-income countries and is predicted to increase with the ageing of populations, urbanisation, and globalisation of risk factors. Furthermore, HIV/AIDS is increasingly becoming a chronic disorder. An integrated approach to the management of chronic diseases, irrespective of cause, is needed in primary health care. Management of chronic diseases is fundamentally different from acute care, relying on several features: opportunistic case finding for assessment of risk factors, detection of early disease, and identification of high risk status; a combination of pharmacological and psychosocial interventions, often in a stepped-care fashion; and long-term follow-up with regular monitoring and promotion of adherence to treatment. To meet the challenge of chronic diseases, primary health care will have to be strengthened substantially. In the many countries with shortages of primary-care doctors, non-physician clinicians will have a leading role in preventing and managing chronic diseases, and these personnel need appropriate training and continuous quality assurance mechanisms. More evidence is needed about the cost-effectiveness of prevention and treatment strategies in primary health care. Research on scaling-up should be embedded in large-scale delivery programmes for chronic diseases with a strong emphasis on assessment.     

Evidence for abnormal granulosa cell responsiveness to follicle-stimulating hormone in women with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) undergoing ovulation induction appear to be extremely sensitive to gonadotropin stimulation and at increased risk for ovarian hyperstimulation syndrome. To determine granulosa cell responsiveness to recombinant human FSH (r-hFSH), dose-response studies were conducted in 16 individual PCOS patients and 7 normal women. Each subject received an iv injection of r-hFSH at doses of 0, 37.5, 75, or 150 IU in a randomized fashion on four separate occasions. Blood samples were obtained at frequent intervals before and for 24 h after r-hFSH administration for measurement of gonadotropins and steroid hormones. Our results showed that administration of r-hFSH produced instantaneous and equivalent dose-related increases in serum FSH in PCOS and normal women, which were followed by similar exponential decreases to baseline levels within 24 h in both groups. In PCOS subjects, the peak mean incremental response of serum estradiol (E(2)) to 150 IU of r-hFSH was 1.8-fold greater (P < 0.0001) and considerably accelerated compared with that found in normal women. In contrast, E(2) responses to 37.5 IU and 75 IU were similar between groups. Regression analysis of maximal E(2) concentrations in response to r-hFSH in each individual subject revealed that the slope of the linear trend line in the group of women with PCOS (r = 0.82) was significantly greater (P < 0.01) than that of normal controls (r = 0.71). The time-course of response revealed that in PCOS women, increases of E(2) were not sustained, compared with those of normal controls, because peak concentrations were followed by an estimated 40% decrement in circulating levels, whereas E(2) levels in normal women persisted for 24 h after reaching maximal values. These findings indicate that women with PCOS exhibit a significantly greater capacity for E(2) production in response to iv r-hFSH, compared with normal women. In PCOS, E(2) production was relatively transient because after peak concentrations a marked decline was detected at each dose, unlike normal women who exhibited persistent elevations of E(2) for up to 24 h. That this distinction was dose-dependent supports the concept of an FSH dose-response threshold, beyond which PCOS but not normal women are susceptible to ovarian hyperresponsiveness.