Lead and cancer in humans: where are we now?

BACKGROUND: Lead is only weakly mutagenic, but in vitro it inhibits DNA repair and acts synergistically with other mutagens. Lead acetate administered orally, cutaneously, or intraperitoneally causes kidney cancer, brain cancer (gliomas), and lung cancer in rodents, and acts synergistically with other carcinogens. Most cytogenetic studies of exposed workers have shown increases in chromosome aberrations or sister chromatid exchange, including some studies with positive-exposure response trends. There are eight studies of cancer mortality or incidence among highly exposed workers; most are cohort studies of lead smelter or battery workers exposed decades ago. METHODS: We reviewed the epidemologic studies with regard to cancer. RESULTS: These studies provide some evidence of increased risk of lung cancer (RR = 1.30, 1.15-1.46, 675 observed deaths) and stomach cancer (combined RR = 1.34, 1.14-1.57, 181 observed). However, the lung cancer findings are not consistent across studies, and confounding by arsenic may affect the study with the highest lung cancer RR. Exclusion of that study yields a combined lung cancer RR of 1.14 (1.04-1.73). There is little evidence of increased risk of kidney cancer (combined RR = 1.01, 0. 72-1.42, 40 observed) or brain cancer (combined RR = 1.06, 0.81-1.40, 69 observed). However, two studies show a two-fold increase in kidney cancer, and one study shows a significant excess of gliomas. IARC classified lead as a "possible human carcinogen" based on sufficient animal data and insufficient human data in 1987. Six of the eight studies cited above have been published since 1987. CONCLUSIONS: Overall, there is only weak evidence associating lead with cancer; the most likely candidates are lung cancer, stomach cancer, and gliomas.     

Statins: where are we now?

Statin therapy reduces the risk of cardiac events by 30% in both primary and secondary prevention. Although fine-tuning of the evidence will occur as more clinical trials report, the challenge is now to implement the evidence to the benefit of patients.     

Condom effectiveness: where are we now?

After performing a review of prospective cohort evaluations, a focussed assessment of the current knowledge base and methodology pertaining to condom effectiveness against sexually transmissible infections, including HIV, was also conducted. Key observations included the point that studies of condom effectiveness are inherently complex and the potential forms of study bias all generally favour the null hypothesis. Perhaps the most challenging obstacle to rigor in these studies lies in determining which events of condom-protected sex occurred before infection as opposed to after infection when, in fact, infection occurs. This problem leads to misclassification bias; however, other sources of misclassification bias are common. Greater attention to the selection of a recall period, improved precision of self-reported measures, and accounting for condom use errors and problems are critical steps that must occur to promote rigor in these studies. Despite multiple shortcomings, prospective studies of condom effectiveness provide a reasonably favourable evaluation. Subsequent studies, however, should be designed to greatly reduce the error variance that predisposes condom effectiveness studies to type 2 errors that mask the potential value of condoms.     

Leadership in the UK NHS: where are we now?

The introduction of changes to the UK National Health Service from the 1980s onwards, coupled with recognition that successful improvement to health and health services places greater pressure on developing good inter-personal and inter-organisational relationships, underlines the need for greater leadership of health services in the future. Argues that insufficient attention has been paid to the development of external leadership, the growing importance of which is emphasised by the most recent proposals for change to health services from the 1997 Labour government. Comparisons of managerial life between the public and private sectors are made and surveys of NHS managerial work, carried out over a number of years, seem to have produced similar conclusions. Finally a paradigm shift is called for in the leadership of health services in the future if the impact of the external environment is to be managed more effectively and no longer to be seen as a constraint on public sector managerial activity.     

Lone atrial fibrillation: where are we now?

There is a growing pandemic of atrial fibrillation (AF), affecting nearly 2% of the general adult population. Atrial fibrillation is commonly associated with structural heart disease, and AF itself causes a sequence of complex processes of electrical, contractile, and structural remodeling of the atrial myocardium, which facilitate further AF progression. Nonetheless, AF may also affect individuals aged ≤ 65 years who have no evidence of associated cardiopulmonary or other disease, including hypertension; this is otherwise referred to as "lone" AF and is considered to have a generally favorable prognosis. The true prevalence of lone AF is unknown. Growing insights into the diversity of numerous mechanisms involved in the pathogenesis of AF, including acute atrial stretch, structural and electrophysiological alterations, systemic inflammation, oxidative stress, autonomic imbalance, genetic predisposition, and many others, and increasing recognition of novel risk factors for AF, including obesity, metabolic syndrome, subclinical atherosclerosis, sleep apnea, alcohol consumption, and endurance sports, suggest that apparently lone AF might not be so "lone" in many patients, which could have important prognostic and therapeutic implications. In this article, we summarize the current knowledge of epidemiology, etiopathogenesis, and pathophysiology of so-called lone AF and discuss the issues of long-term prognosis and management of patients who have an apparently lone AF.     

Diet and cancer: where are we and where are we going?

Many studies have shown that overall dietary patterns, dietary components consumed, or mode of food preparation are all possibly relevant in either reducing or increasing the risk of cancer in animals or man. Yet, dietary intervention studies, stemming from laboratory and epidemiological observational studies have often failed to demonstrate the anticipated protection against cancer. One possible explanation for the discrepancy between the results of various observational and experimental chemo-prevention studies is the lack of control for biological diversity of the participants of these studies. It is suggested that future epidemiological studies provide evidence stratified by status of major metabolic polymorphisms pertinent to the study subject, and that future intervention studies take these differences into account in the design and analysis phases.     

Genetics of ischemic stroke: where are we now?

As stroke is the third leading cause of death after heart failure and tumors worldwide, cerebrovascular diseases reached substantial attention. In the past few years, significant progression has been seen in identification of genetic variants in the background of stroke and other cerebrovascular and cardiovascular events. Examination of these variants is a new approach to recognize pathogenesis of disorders that hopefully helps in future prevention and prospects of screening and, optimistically, it contributes to special care of patients susceptible for stroke. In the background of ischemic stroke several genetic variants have been identified, which localize in genes encoding proteins involved in hemostasis, renin-angiotensin system and lipid metabolism. The number of these variants exponentially increases permanently due to rapid spreading of genome wide association studies. The goal of this review is to summarize the results of genetic studies on ischemic stroke. Here the authors focus on genetic variants which can have major role in personalized medicine and prevention of stroke.     

Professional regulation of nutritionists: where are we now?

Waterlow's (1981) Sixth Boyd Orr Lecture on a 'crisis of identity for nutrition' stimulated the Nutrition Society's drive to professionalisation. Twenty-five years on, the Society begins a new stage; first, towards an independent voluntary regulator, and then towards statutory regulation. It is timely to reflect on progress and identify the remaining challenges. The Society has made impressive progress as a voluntary regulator since 1991 when the Institute of Biology opened a register in cooperation with the Institute of Food Science and Technology and the Nutrition Society; the present register is 2.75-fold larger. The Society has specialist standards for course accreditation that enable graduates to apply for direct entry to the register, having met standards of competency in nutrition or public health nutrition. A code of ethics and a statement of professional conduct underpin a functioning system for oversight and governance that protects the public, the hallmark of all professions. Registered nutritionists lay easy claim to a unique science basis for their profession. A scheme for continuing professional development (CPD) started in July 2006, 1 year before a sample audit starts to show the link between CPD and re-registration. The scheme will be piloted in the first year. The critical challenge is the issue of identity. Waterlow (1981) stated that professional registration must lead explicitly and formally to a specific vocation, an occupation that provides services that society requires and one that contributes to the well-being and health of all. The present time may be the last and best chance for nutritionists, as nutrition has a higher priority for government in the UK than ever before. The Society has begun to help in strategic public health workforce planning and development; new and still plastic, it is the ideal locus from which a discipline and a profession can emerge. The CPD scheme will work if it helps nutritionists meet their own needs; more mutual cooperation and consensus about real world standards of performance are needed. Nutritionists need to show how they actually contribute to national health and/or wealth. Then, sustained resources can be advocated for and the support of the voting public and legislators secured, without which it will not be possible to get the legal protection that is desirable for the profession.     

Medical sociology and the biological body: where are we now and where do we go from here?

In this article I pose the question, 'where is the biological body in medical sociology today?' The first part of the article provides a selective corporeal balance sheet of where we are now in medical sociology, with particular reference to social constructionist and phenomenological approaches and their respective stances or takes on the (biological) body. The subsequent section considers where we might profitably be going in the future in terms of bringing the biological body (back) in, and the broader issues this raises for the sociological enterprise as a whole. Various problems associated with this evolving project and merits of other recent approaches, such as the sociology of translation, are considered. The article concludes with some further thoughts and reflections on these matters, including a revisiting of relations between the sociology of the body and medical sociology in the light of these debates.