49 research outputs found
In vivo arginine production and nitric oxide synthesis in pregnant Indian women with normal and low body mass indices
A systematic review of physical activity and sedentary behaviour research in the oil-producing countries of the Arabian Peninsula
Racism as a determinant of health: a systematic review and meta-analysis
Despite a growing body of epidemiological evidence in recent years documenting the health impacts of racism, the cumulative evidence base has yet to be synthesized in a comprehensive meta-analysis focused specifically on racism as a determinant of health. This meta-analysis reviewed the literature focusing on the relationship between reported racism and mental and physical health outcomes. Data from 293 studies reported in 333 articles published between 1983 and 2013, and conducted predominately in the U.S., were analysed using random effects models and mean weighted effect sizes. Racism was associated with poorer mental health (negative mental health: r = -.23, 95% CI [-.24,-.21], k = 227; positive mental health: r = -.13, 95% CI [-.16,-.10], k = 113), including depression, anxiety, psychological stress and various other outcomes. Racism was also associated with poorer general health (r = -.13 (95% CI [-.18,-.09], k = 30), and poorer physical health (r = -.09, 95% CI [-.12,-.06], k = 50). Moderation effects were found for some outcomes with regard to study and exposure characteristics. Effect sizes of racism on mental health were stronger in cross-sectional compared with longitudinal data and in non-representative samples compared with representative samples. Age, sex, birthplace and education level did not moderate the effects of racism on health. Ethnicity significantly moderated the effect of racism on negative mental health and physical health: the association between racism and negative mental health was significantly stronger for Asian American and Latino(a) American participants compared with African American participants, and the association between racism and physical health was significantly stronger for Latino(a) American participants compared with African American participants.<br /
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Racial/Ethnic Disparities in Inadequate Gestational Weight Gain Differ by Pre-pregnancy Weight
OBJECTIVES: Pre-pregnancy body mass index (BMI) varies by race/ethnicity and modifies the association between gestational weight gain (GWG) and adverse pregnancy outcomes, which disproportionately affect racial/ethnic minorities. Yet studies investigating whether racial/ethnic disparities in GWG vary by pre-pregnancy BMI are inconsistent, and none studied nationally representative populations. METHODS: Using categorical measures of GWG adequacy based on Institute of Medicine recommendations, we investigated whether associations between race/ethnicity and GWG adequacy were modified by pre-pregnancy BMI [underweight (<18.5kg/m(2)), normal weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), or obese (≥30.0 kg/m(2)) ] among all births to Black, Hispanic, and White mothers in the 1979 USA National Longitudinal Survey of Youth cohort (n=6849 pregnancies; range=1-10). We used generalized estimating equations, adjusted for marital status, parity, smoking during pregnancy, gestational age, and multiple measures of socioeconomic position. RESULTS: Effect measure modification between race/ethnicity and pre-pregnancy BMI was significant for inadequate GWG (Wald test p-value=0.08). Normal weight Black (Risk Ratio (RR)=1.34, 95% confidence interval (CI): 1.18, 1.52) and Hispanic women (RR=1.33, 95%CI: 1.15, 1.54) and underweight Black women (RR=1.38; 95% CI: 1.07, 1.79) experienced an increased risk of inadequate GWG compared to Whites. Differences in risk of inadequate GWG between minority women, compared to White women, were not significant among overweight and obese women. Effect measure modification between race/ethnicity and pre-pregnancy BMI was not significant for excessive GWG. CONCLUSIONS: The magnitude of racial/ethnic disparities in inadequate GWG appears to vary by pre-pregnancy weight class, which should be considered when designing interventions to close racial/ethnic gaps in healthy GWG
The Geomechanics of CO2 Storage in Deep Sedimentary Formations
This paper provides a review of the geomechanics and modeling of geomechanics associated with geologic carbon storage (GCS), focusing on storage in deep sedimentary formations, in particular saline aquifers. The paper first introduces the concept of storage in deep sedimentary formations, the geomechanical processes and issues related with such an operation, and the relevant geomechanical modeling tools. This is followed by a more detailed review of geomechanical aspects, including reservoir stress-strain and microseismicity, well integrity, caprock sealing performance, and the potential for fault reactivation and notable (felt) seismic events. Geomechanical observations at current GCS field deployments, mainly at the In Salah CO2 storage project in Algeria, are also integrated into the review. The In Salah project, with its injection into a relatively thin, low-permeability sandstone is an excellent analogue to the saline aquifers that might be used for large scale GCS in parts of Northwest Europe, the U.S. Midwest, and China. Some of the lessons learned at In Salah related to geomechanics are discussed, including how monitoring of geomechanical responses is used for detecting subsurface geomechanical changes and tracking fluid movements, and how such monitoring and geomechanical analyses have led to preventative changes in the injection parameters. Recently, the importance of geomechanics has become more widely recognized among GCS stakeholders, especially with respect to the potential for triggering notable (felt) seismic events and how such events could impact the long-term integrity of a CO{sub 2} repository (as well as how it could impact the public perception of GCS). As described in the paper, to date, no notable seismic event has been reported from any of the current CO{sub 2} storage projects, although some unfelt microseismic activities have been detected by geophones. However, potential future commercial GCS operations from large power plants will require injection at a much larger scale. For such largescale injections, a staged, learn-as-you-go approach is recommended, involving a gradual increase of injection rates combined with continuous monitoring of geomechanical changes, as well as siting beneath a multiple layered overburden for multiple flow barrier protection, should an unexpected deep fault reactivation occur
Biliary reconstruction when the liver hilum is inaccessible: The anterior approach
Objective: This paper focuses on a novel approach to biliary reconstruction after previous extensive liver surgery. Summary background data: Bile leak and subsequent biliary strictures are not uncommon after extensive liver surgery. Biliary reconstruction is then required, but the liver hilum is usually inaccessible for further surgical intervention. Methods: A novel surgical technique is described in two patients with biliary stenosis after previous extensive liver surgery. Access to the biliary tree was obtained using an anterior approach. A previously inserted PTC drain was used as guidance to the bile duct suitable for creating a biliary-digestive anastomosis. Results: The described technique proved to cause complete biliary drainage in both patients. There was no treatment-related morbidity nor was further biliary intervention needed during follow-up. (C) 2011 Elsevier Ltd. All rights reserved
Renal cell carcinoma metastases to gallbladder
A 74-year old man underwent a radical cholecystectomy for presumed gallbladder cancer. The histology of the resected specimen in fact revealed the lesion to be metastatic renal cell carcinoma from his resected right nephrectomy performed 14 years previously
Metal stents: a bridge to surgery in hilar cholangiocarcinoma
Background Obstructive jaundice in patients with hilar cholangiocarcinoma is a known risk factor for hepatic failure after liver resection. Plastic stents are most widely used for preoperative drainage. However, plastic stents are known to have limited patency time and therefore, in palliative settings, the self-expanding metal stent (SEMS) is used. This type of stent has been shown to be superior because it allows for rapid biliary decompression and a reduced complication rate after insertion. This study explores the use of the SEMS for biliary decompression in patients with operable hilar cholangiocarcinoma. Methods A retrospective evaluation of a prospectively maintained database at a tertiary hepatobiliary referral centre was carried out. All patients with resectable cholangiocarcinoma were recorded. Results Of 260 patients referred to this unit with cholangiocarcinoma between January 2008 and April 2012, 50 patients presented with operable cholangiocarcinoma and 27 of these had obstructive jaundice requiring stenting. Ten patients were initially treated with SEMSs; no stent failure occurred in these patients. Seventeen patients initially received plastic stents, seven of which failed in the interval between stent placement and laparotomy. These stents were replaced by SEMSs in four patients and by plastic stents in three patients. Median time to laparotomy was 45 days and 68 days in patients with SEMSs and plastic stents, respectively. Conclusions Self-expanding metal stents provide adequate and rapid biliary drainage in patients with obstruction caused by hilar cholangiocarcinoma. No re-interventions were required. This probably reflects the relatively short interval between stent placement and laparotomy