Effects of maternal nicotine exposure during lactation on breast-fed rat pups

Background: Nicotine is known to be associated with adverse effects in infants and children. It is concentrated in breast milk and is absorbed by the infant. The aim of this study was to investigate the effects on breast-fed rat pups of maternal nicotine exposure during lactation. Methods: In the experimental group (n = 6), nicotine was given to lactating dams (2 mg/kg/day) after delivery and continued for 10 days during lactation. Control animals (n = 4) received saline for the same duration. The suckling rats were weighed and killed on postnatal day 10, and samples were taken from the lung, liver, kidney, spleen and small intestine for histopathological examination. Superoxide dismutase (SOD), catalase (CAT) activities and malondialdehyde (MDA) levels were measured in the liver of the dam and the offspring. Results: Histopathological changes in the liver of the nicotine-exposed group showed portal inflammatory infiltrate, ballooning degeneration of hepatocytes, and focal necrosis in the parenchyma. Thickening of alveolar walls because of interstitial inflammation was noted in the lungs. Histopathological examination of kidney, spleen and small intestine tissue did not reveal any abnormality. In the experimental group, SOD and CAT activities were significantly decreased (p < 0.001) but MDA levels were significantly increased (p < 0.001) compared with the control group. Conclusion: These results indicate that maternal nicotine exposure induces oxidative stress and causes detrimental histopathological changes in the lung and liver of lactating offspring. Copyright (C) 2005 S. Karger AG, Basel

Time-varying parameters Realized GARCH models for tracking attenuation bias in volatility dynamics

This paper proposes novel approaches to the modelling of attenuation bias effects in volatility forecasting. Our strategy relies on suitable generalizations of the Realized GARCH model by Hansen et al. (2012) where the impact of lagged realized measures on the current conditional variance is weighted according to the accuracy of the measure itself at that specific time point. This feature allows assigning more weight to lagged volatilities when they are more accurately measured. The ability of the proposed models to generate accurate forecasts of volatility and related tail risk measures, Value-at-Risk (VaR) and Expected Shortfall (ES), is assessed by means of an application to a set of major stock market indices. The results of the empirical analysis show that the proposed specifications are able to outperform standard Realized GARCH models in terms of out-of-sample forecasting performance under both statistical and economic criteria

Items for developing revised classification criteria in systemic sclerosis: Results of a consensus exercise with the ACR/EULAR working committee for classification criteria in systemic sclerosis.

Background Classification criteria for systemic sclerosis (SSc) are being updated. Objective To select a set of items potentially useful for the classification of SSc using consensus procedures including the Delphi and nominal group techniques (NGT). Methods Items were identified through two independent consensus exercises performed by the Scleroderma Clinical Trials Consortium (SCTC) and the EULAR Scleroderma Trials and Research Group (EUSTAR). The first-round items from both exercises were collated and redundancies were removed leaving 168 items. A 3-round Delphi exercise was performed using a 1–9 scale (1=completely inappropriate and 9=completely appropriate) and a consensus meeting using NGT. During the last Delphi, the items were ranked on a 1–10 scale. Results Round 1: 106 experts rated the 168 items. Those with a median score <4 were removed, resulting in a list of 102 items. Round 2: The items were again rated for appropriateness and subjected to a consensus meeting using NGT by European and North American SSc experts (n=16), resulting in 23 items. Round 3: SSc experts (n=26) then individually scored each of the 23 items in a last Delphi round, using an appropriateness score (1–9) and ranking their 10 most appropriate items for classification of SSc. Presence of skin thickening, SSc-specific autoantibodies, abnormal nailfold capillary pattern and Raynaud’s phenomenon ranked highest in the final list that also included items indicating internal organ involvement. Conclusion The Delphi exercise and NGT resulted in a set of 23 items for classification of SSc which will be assessed for their discriminative properties in a prospective study