Post-translational modifications in prion diseases.

More than 650 reversible and irreversible post-translational modifications (PTMs) of proteins have been listed so far. Canonical PTMs of proteins consist of the covalent addition of functional or chemical groups on target backbone amino-acids or the cleavage of the protein itself, giving rise to modified proteins with specific properties in terms of stability, solubility, cell distribution, activity, or interactions with other biomolecules. PTMs of protein contribute to cell homeostatic processes, enabling basal cell functions, allowing the cell to respond and adapt to variations of its environment, and globally maintaining the constancy of the milieu interieur (the body's inner environment) to sustain human health. Abnormal protein PTMs are, however, associated with several disease states, such as cancers, metabolic disorders, or neurodegenerative diseases. Abnormal PTMs alter the functional properties of the protein or even cause a loss of protein function. One example of dramatic PTMs concerns the cellular prion protein (PrPC), a GPI-anchored signaling molecule at the plasma membrane, whose irreversible post-translational conformational conversion (PTCC) into pathogenic prions (PrPSc) provokes neurodegeneration. PrPC PTCC into PrPSc is an additional type of PTM that affects the tridimensional structure and physiological function of PrPC and generates a protein conformer with neurotoxic properties. PrPC PTCC into PrPSc in neurons is the first step of a deleterious sequence of events at the root of a group of neurodegenerative disorders affecting both humans (Creutzfeldt-Jakob diseases for the most representative diseases) and animals (scrapie in sheep, bovine spongiform encephalopathy in cow, and chronic wasting disease in elk and deer). There are currently no therapies to block PrPC PTCC into PrPSc and stop neurodegeneration in prion diseases. Here, we review known PrPC PTMs that influence PrPC conversion into PrPSc. We summarized how PrPC PTCC into PrPSc impacts the PrPC interactome at the plasma membrane and the downstream intracellular controlled protein effectors, whose abnormal activation or trafficking caused by altered PTMs promotes neurodegeneration. We discussed these effectors as candidate drug targets for prion diseases and possibly other neurodegenerative diseases.

Assessing the impact of coexposure on the measurement of biomarkers of exposure to the pyrethroid lambda-cyhalothrin in agricultural workers.

There are few published data on the impact of combined exposure to multiple pesticides (coexposure) on levels of biomarkers of exposure in workers, which may alter their toxicokinetics and thus the interpretation of biomonitoring data. This study aimed to assess the impact of coexposure to two pesticides with shared metabolism pathways on levels of biomarkers of exposure to pyrethroid pesticides in agricultural workers. The pyrethroid lambda-cyhalothrin (LCT) and the fungicide captan were used as sentinel pesticides, since they are widely sprayed concomitantly in agricultural crops. Eighty-seven (87) workers assigned to different tasks (application, weeding, picking) were recruited. The recruited workers provided two-consecutive 24-h urine collections following an episode of lambda-cyhalothrin application alone or in combination with captan or following tasks in the treated fields, as well as a control collection. Concentrations of lambda-cyhalothrin metabolites - 3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethyl-cyclopropanecarboxylic acid (CFMP) and 3-phenoxybenzoic acid (3-PBA) - were measured in the samples. Potential determinants of exposure established in a previous study, including the task performed and personal factors were documented by questionnaire. Multivariate analyses showed that coexposure did not have a statistically significant effect on the observed urinary levels of 3-PBA (Exp(ß) (95% confidence interval (95% CI)): 0.94 (0.78-1.13)) and CFMP (1.10 (0.93-1.30). The repeated biological measurements ("time variable") - defined as the within-subjects variable - was a significant predictor of observed biological levels of 3-PBA and CFMP; the within-subjects variance (Exp(ß) (95% (95% CI)) for 3-PBA and CFMP was 1.11 (1.09-3.49) and 1.25 (1.20-1.31). Only the main occupational task was associated with urinary levels of 3-PBA and CFMP. Compared to the weeding or picking task, the pesticide application task was associated with higher urinary 3-PBA and CFMP concentrations. In sum, coexposure to agricultural pesticides in the strawberry fields did not increase pyrethroid biomarker concentrations at the exposure levels observed in the studied workers. The study also confirmed previous data suggesting that applicators were more exposed than workers assigned to field tasks such as weeding and picking.

Sudden unexpected deaths and vaccinations during the first two years of life in Italy: a case series study.

BACKGROUND: The signal of an association between vaccination in the second year of life with a hexavalent vaccine and sudden unexpected deaths (SUD) in the two days following vaccination was reported in Germany in 2003. A study to establish whether the immunisation with hexavalent vaccines increased the short term risk of SUD in infants was conducted in Italy. METHODOLOGY/PRINCIPAL FINDINGS: The reference population comprises around 3 million infants vaccinated in Italy in the study period 1999-2004 (1.5 million received hexavalent vaccines). Events of SUD in infants aged 1-23 months were identified through the death certificates. Vaccination history was retrieved from immunisation registries. Association between immunisation and death was assessed adopting a case series design focusing on the risk periods 0-1, 0-7, and 0-14 days after immunisation. Among the 604 infants who died of SUD, 244 (40%) had received at least one vaccination. Four deaths occurred within two days from vaccination with the hexavalent vaccines (RR = 1.5; 95% CI 0.6 to 4.2). The RRs for the risk periods 0-7 and 0-14 were 2.0 (95% CI 1.2 to 3.5) and 1.5 (95% CI 0.9 to 2.4). The increased risk was limited to the first dose (RR = 2.2; 95% CI 1.1 to 4.4), whereas no increase was observed for the second and third doses combined. CONCLUSIONS: The RRs of SUD for any vaccines and any risk periods, even when greater than 1, were almost an order of magnitude lower than the estimates in Germany. The limited increase in RRs found in Italy appears confined to the first dose and may be partly explained by a residual uncontrolled confounding effect of age.

[Use of neuropsychological tests in the Cronos Project]. / L'uso degli strumenti neuropsicologici nell'ambito del Progetto Cronos.

Within the Cronos Project, 503 Alzheimer's disease units were activated throughout the country. In June/July 2002 a questionnaire was sent to all Alzheimer's disease units to collect data on neuropsychological tests utilised in the diagnostic process of dementias. Only 196 of Alzheimer's disease units that have responded to the questionnaire (196/392) declare to utilize neuropsychological test while 97.8% use the mini mental state examination. This paper aims to collect, for the first time in Italy, data on use of the neuropsychological tests in the specialist units on dementia and to propose a discussion on the reliability of neuropsychological instruments.

Complementary and alternative medicine in the scientific literature.

OBJECTIVE: To analyze the frequency and typology of scientific papers on complementary and alternative medicine (CAM) published in the period 1997-2002. METHODS: We performed a systematic literature search of MEDLINE in order to identify all articles dealing with CAM, in the human setting, published from January 1, 1997 to December 31, 2002. Our attention was focused on randomized controlled trials conducted on CAM and on the impact factor (IF) of the journals in which CAM articles were published. RESULTS: During the period 1997-2002, a total of 20,209 articles about CAM were published, representing the 0.7% of the total number of MEDLINE-listed articles. Approximately 50% of CAM articles published in 1996-2002 appeared on journals with no IF. The proportion of randomized clinical trials was 7.6% of total CAM articles. CONCLUSIONS: There is an upward trend in the number of CAM articles but the number of experimental studies is low and over half of articles are published in journals without an IF. We believe there is an urgent need to conduct rigorous research in the field of CAM in order to support, for the need of the public, an evidence-based approach to these therapies.

The cerivastatin withdrawal crisis: a "post-mortem" analysis.

In August 2001, cerivastatin was removed from European and USA markets because of a higher risk of rhabdomyolysis associated with its use in comparison with other statins. The objective of this study was to compare cholesterol-lowering drug use in Italy before and after the withdrawal of cerivastatin from the market, and to evaluate if the withdrawal influenced patients compliance and physicians prescribing habits. After August 2001, 48% of cerivastatin users discontinued any statin treatment. The major risk factor for discontinuation was a concomitant use of fibrate during the first 7 months of 2001 (OR = 2.3; 95% CI = -2.9). Comparing the discontinuation of statin therapy between 2001 and 2000 we can estimate that there was a 5% increase, corresponding to about 200,000 patients, who discontinued statin therapy during autumn 2001 because of cerivastatin emergency.

Cohort study of hepatotoxicity associated with nimesulide and other non-steroidal anti-inflammatory drugs.

OBJECTIVE: To estimate the risk of acute hepatotoxicity associated with nimesulide compared with other non-steroidal anti-inflammatory drugs. DESIGN: Retrospective cohort and nested case-control study. SETTING: Umbria region, Italy. PARTICIPANTS: 400 000 current, recent, and past users (almost 2 million prescriptions) of non-steroidal anti-inflammatory drugs between 1 January 1997 and 31 December 2001. MAIN OUTCOME MEASURES: Admissions to hospital for acute non-viral hepatitis and incidence of all hepatopathies and liver injury among users of nimesulide and other non-steroidal anti-inflammatory drugs. RESULTS: Current use of non-steroidal anti-inflammatory drugs was associated with a 1.4 (95% confidence interval 1.0 to 2.1) increased risk of hepatopathy compared with past use. In current users of nimesulide the rate ratio for all hepatopathies and more severe liver injury was 1.3 (0.7 to 2.3) and 1.9 (1.1 to 3.8), respectively. CONCLUSION: The risk of liver injury in patients taking nimesulide and other non-steroidal anti-inflammatory drugs is small.