Obfuscating transparency?

Several recent and prominent articles in Science and Nature deliberately mischaracterized the nature of genuine scientific evidence. Those articles take issue with the United States Environmental Protection Agency's recent proposal to structure its policies and rules only from studies with transparently published raw data. The articles claim it is an effort to obfuscate with transparency, by eliminating a host of studies not offering raw data.

Do occupational exposures to vinyl chloride cause hepatocellular carcinoma and cirrhosis?

Controversy exists about the association between occupational exposures to vinyl chloride and hepatocellular carcinoma and cirrhosis. Two large multicentre mortality cohort studies, one American and another European, reported higher mortality for primary cancer of liver and biliary tract. However, the American study was not able to rule out misclassification, because based on death certificates and under the heading primary liver cancers, some angiosarcomas, the typical neoplasia associated with vinyl chloride, may have been included.

Upholding science in health, safety and environmental risk assessments and regulations.

A public appeal has been advanced by a large group of scientists, concerned that science has been misused in attempting to quantify and regulate unmeasurable hazards and risks. The appeal recalls that science is unable to evaluate hazards that cannot be measured, and that science in such cases should not be invoked to justify risk assessments in health, safety and environmental regulations. The appeal also notes that most national and international statutes delineating the discretion of regulators are ambiguous about what rules of evidence ought to apply.

Organophosphorus and carbamate insecticide poisoning.

Both organophosphorus (OP) and carbamate insecticides inhibit acetylcholinesterase (AChE), which results in accumulation of acetylcholine (ACh) at autonomic and some central synapses and at autonomic postganglionic and neuromuscular junctions. As a consequence, ACh binds to, and stimulates, muscarinic and nicotinic receptors, thereby producing characteristic features. With OP insecticides (but not carbamates), "aging" may also occur by partial dealkylation of the serine group at the active site of AChE; recovery of AChE activity requires synthesis of new enzyme in the liver.

Evaluating suspected work-related neurologic disorders (clinical diagnosis).

The clinical diagnosis of work-related neurologic disorders is essentially one of exclusion because symptoms and signs are often nonspecific. The clinical reasoning requires a three-step approach: (1) establish the characteristics of the presenting disease; (2) ascertain that observed clinical features are consistent with those caused by the suspected agent(s); and (3) assess occupational exposures. A detailed history is of paramount importance in evaluating patients with suspected work-related neurologic disorders as it is in other clinical contexts, especially because in some circumstances it may represent the only criterion to establish causality.

Principles and practice of occupational neurology: an overview.

Diseases of both central and peripheral nervous systems may be the consequence of chemical and physical exposures occurring in the workplace. The resulting syndromes depend upon the type of hazard, of exposure (acute vs chronic), and of neuronal organization that is affected. Diagnosis of occupational neurologic diseases may prove to be difficult because they rarely display pathognomonic signs and almost always a quantitative assessment of exposure is missing.

Biological monitoring of carcinogens: current status and perspectives.

Biomonitoring exposures to carcinogens is common practice and a variety of biomarkers have been developed to assess both exposures and biochemical/biological effects. However, their clinical and preventive relevance is still uncertain. The understanding of cancer as a genetic disease has dramatically evolved during last decades, showing that cancer cell types acquire their characteristics with different strategies, time frames and microenvironments.

[Causality in occupational oncology: the toxicologist opinion].

General and individual causality in occupational oncology should be regarded as diverse and largely autonomous concepts. General causality is based upon a statement such as "the chemical is a carcinogen" and must be considered for preventive action. Individual causality implies that the statement has to be applied to a patient exposed to that chemical.

[New perspectives in monitoring of exposures to carcinogens].

Biomonitoring occupational and environmental exposures to carcinogens is a common practice and several biomarkers have been developed for risk assessment. However, in particular, because of the lack of prospective studies, the place of these biomarkers within the complex scenario of the gene-environment interactions leading to cancer cannot be defined. New opportunities and suggestions for biomonitoring exposures to carcinogens could derive from exploring the exposome, from the results of genomewide association and omic studies.

Individual exposure to particulate matter and heart rate variability (HRV) in patients with previous myocardial infarction.

The exposures to particulate matter (PM) from urban air correlates with a variety of cardiovascular diseases, including myocardial infraction. Protection from the effects of particles on HRV by beta-blockers was observed.

Occupational toxicology of asbestos-related malignancies.

Introduction: Asbestos is banned in most Western countries but related malignancies are still of clinical concern because of their long latencies. This review identifies and addresses some controversial occupational and clinical aspects of asbestos-related malignancies.

Methods: Papers published in English from 1980 to 2009 were retrieved from PubMed.

Soluble phenyl valerate esterases of hen sciatic nerve and the potentiation of organophosphate induced delayed polyneuropathy.

Contrary to some organophosphorus esters (OPs), certain esterase inhibitors including sulfonyl halides, carbamates and phosphinates do not cause axonal neuropathy, but they may exacerbate traumatic and some chemical insults to axons. This phenomenon is referred to as the promotion/potentiation of axonopathies. We report here promotion studies of the organophosphate induced delayed polyneuropathy (OPIDP).

Individual exposure to particulate matter and the short-term arrhythmic and autonomic profiles in patients with myocardial infarction.

Aims: Epidemiological studies show that peak exposure to air pollution is associated with increased morbidity and mortality from cardiovascular events. Panel and controlled exposure studies show that particulate matter (PM) may influence the parasympathetic regulation of the heart. The aim of this study was to concurrently measure individual exposure to PM of various sizes, heart rate variability (HRV), and electrical instability in patients with myocardial infarction.

Is the acceptable daily intake as presently used an axiom or a dogma?

International scientific committees, regional scientific committees such as those of the European Union, and national regulatory agencies generally use the uncertainly factor approach for establishing acceptable or tolerable intakes of substances that exhibit thresholds of toxicity. No observed adverse effect levels (NOAELs) are identified in the critical studies to which appropriate uncertainly factors are applied to allocate acceptable daily intake (ADI). This paper discusses the different steps of the risk assessment process considered for decades worldwide a pragmatic approach to allocate safe doses, yet in need of improvements during the extrapolation phase which could increase the confidence level of the work performed by risk assessors.

Short-term effects of particulate matter: an inflammatory mechanism?

"Would you tell me please, which way I ought to go from here," asked Alice. "That depends a good deal on where you want to go to," said the cat. (Lewis Carroll, Alice's Adventures in Wonderland) A large number of epidemiological studies show positive correlations between increasing levels of particulate matter (PM) in urban air and short-term morbidity and mortality for diverse acute cardiopulmonary diseases.

Do carbamates cause polyneuropathy?

Carbamates are reversible inhibitors of acetylcholinesterase, and some also inhibit neuropathy target esterase (NTE), the target in organophosphate-induced delayed polyneuropathy. However, based on mechanistic considerations, these carbamates were thought to be unable to initiate polyneuropathy. Consequently, clinical reports of polyneuropathy associated with carbamate exposures have been disregarded.

Peripheral nerve esterases and the promotion of organophosphate-induced neuropathy in hens.

Several esterase inhibitors, not capable of causing peripheral neuropathy by themselves, exacerbate organophosphate-induced delayed polyneuropathy (OPIDP) and other axonopathies. This effect was called promotion of axonopathies and it was found not to be associated with inhibition of neuropathy target esterase (NTE), the molecular target of OPIDP. The search for an esterase as the target of promotion has started long ago, when an eterogeneous group of esterases-hydrolysing phenyl valerate (PV) was identified in hen's sciatic nerve by means of selective inhibitors.