How do short-term rates of femorotibial cartilage change compare to long-term changes? Four year follow-up data from the osteoarthritis initiative

OBJECTIVE: To compare unbiased estimates of short- vs long-term cartilage loss in osteoarthritic knees. METHOD: 441 knees [216 Kellgren Lawrence (KL) grade 2, 225 KL grade 3] from participants of the Osteoarthritis Initiative were studied over a 4-year period. Femorotibial cartilage thickness was determined using 3?T double echo steady state magnetic resonance imaging, the readers being blinded to time points. Because common measurement time points bias correlations, short-term change (year-1 to year-2: Y1?→?Y2) was compared with long-term change (baseline to year-4: BL?→?Y4), and initial (BL?→?Y1) with subsequent (Y2?→?Y4) observation periods. RESULTS: The mean femorotibial cartilage thickness change (standardized response mean) was?-1.2%/-0.8% (-0.42/-0.28) over 1 (BL?→?Y1/Y1?→?Y2),?-2.1%/-2.5% (-0.56/-0.55) over 2 (BL?→?Y2/Y2?→?Y4),?-3.3% (-0.63) over 3 (Y1?→?Y4), and?-4.5% (-0.78) over 4 years. Spearman correlations were 0.33 for Y1?→?Y2 vs BL?→?Y4, and 0.17 for BL?→?Y1 vs Y2?→?Y4 change. Percent agreement between knees showing progression during Y1?→?Y2 vs BL?→?Y4 was 59%, and 64% for BL?→?Y1 vs Y2?→?Y4. The area under the receiver operating characteristic curve was 0.66 for using Y1?→?Y2 to predict BL?→?Y4, and 0.59 for using BL?→?Y1 to predict Y2?→?Y4 change. CONCLUSION: Weak to moderate correlations and agreement were observed between individual short- vs long-term cartilage loss, and between initial and subsequent observation periods. Hence, longer observation periods are recommended to achieve robust results on cartilage loss in individual knees. At cohort and subcohort level (e.g., KLG3 vs KLG2 knees), the mean cartilage loss increased almost linearly with the length of the observation period and was constant throughout the study.     

Fruit, vegetables, fibre and micronutrients and risk of US renal cell carcinoma

The association between renal cell cancer (RCC) and intake of fruit, vegetables and nutrients was examined in a population-based case-control study of 323 cases and 1827 controls; dietary intake was obtained using a mailed questionnaire. Cancer risks were estimated by OR and 95?% CI, adjusting for age, sex, smoking, obesity, hypertension, proxy status, alcohol consumption and dietary fat intake and energy. Intake of vegetables was associated with a decreased risk of RCC (OR 0·5; 95?% CI 0·3, 0·7; P trend?=?0·002), (top compared to the bottom quartile of intake). When intake of individual nutrients was investigated, vegetable fibre intake was associated with decreased risks (OR 0·4; 95?% CI 0·2, 0·6; P?相似文献   

Peripheral nervous system function and organophosphate pesticide use among licensed pesticide applicators in the Agricultural Health Study

Background: Evidence is limited that long-term human exposure to organophosphate (OP) pesticides, without poisoning, is associated with adverse peripheral nervous system (PNS) function.Objective: We investigated associations between OP pesticide use and PNS function by administering PNS tests to 701 male pesticide applicators in the Agricultural Health Study (AHS).Methods: Participants completed a neurological physical examination (NPx) and electrophysiological tests as well as tests of hand strength, sway speed, and vibrotactile threshold. Self-reported information on lifetime use of 16 OP pesticides was obtained from AHS interviews and a study questionnaire. Associations between pesticide use and measures of PNS function were estimated with linear and logistic regression controlling for age and outcome-specific covariates.Results: Significantly increased odds ratios (ORs) were observed for associations between ever use of 10 of the 16 OP pesticides and one or more of six NPx outcomes. Most notably, abnormal toe proprioception was significantly associated with ever use of 6 OP pesticides, with ORs ranging from 2.03 to 3.06; monotonic increases in strength of association with increasing use was observed for 3 of the 6 pesticides. Mostly null associations were observed between OP pesticide use and electrophysiological tests, hand strength, sway speed, and vibrotactile threshold.Conclusions: This study provides some evidence that long-term exposure to OP pesticides is associated with signs of impaired PNS function among pesticide applicators.     

A spatio-temporal absorbing state model for disease and syndromic surveillance

Reliable surveillance models are an important tool in public health because they aid in mitigating disease outbreaks, identify where and when disease outbreaks occur, and predict future occurrences. Although many statistical models have been devised for surveillance purposes, none are able to simultaneously achieve the important practical goals of good sensitivity and specificity, proper use of covariate information, inclusion of spatio-temporal dynamics, and transparent support to decision-makers. In an effort to achieve these goals, this paper proposes a spatio-temporal conditional autoregressive hidden Markov model with an absorbing state. The model performs well in both a large simulation study and in an application to influenza/pneumonia fatality data.     

The coagulant-active phospholipid content is a major determinant of in vivo thrombogenicity of prothrombin complex (Factor IX) concentrates in rabbits

In vitro evaluation of prothrombin complex concentrates in a thrombin generation assay, using DAPA and purified components of the prothrombinase complex, demonstrated significant levels of coagulant- active "phospholipid replacing" activity. Quantification of this activity showed a significant correlation (r = 0.8747, p less than 0.01) with thrombogenicity measured in vivo in a stasis model in rabbits. Extracted lipid material retained full phospholipid replacing activity in the vitro assay. Thin-layer chromatographic characterization confirmed the presence of phospholipids with known coagulant activity in vitro. In vivo, the extracted material was nonthrombogenic but augmented the thrombogenicity of purified factor Xa. Substitution of a synthetic coagulant-active phospholipid (phosphatidylcholine-phosphatidylserine lipid vesicles) for the extracted phospholipid produced a similar augmentation of a factor-Xa- induced thrombogenicity in vivo. It is concluded that the coagulant- active phospholipid content of prothrombin complex concentrates is a major determinant of thrombogenicity but requires the presence of activated clotting factors for its expression in vivo.