Association between cardiovascular risk-factors and venous thromboembolism in a large longitudinal study of French women.

BACKGROUND: Previous studies have shown conflicting results regarding the influence of cardiovascular risk-factors on venous thromboembolism. This study aimed to determine if these risk-factors, i.e. physical activity, smoking, hypertension, dyslipidaemia, and diabetes, were associated with the risk of venous thromboembolism, and to determine if these associations were confounded by BMI. METHODS: We used data from the E3N cohort study, a French prospective population-based study initiated in 1990, consisting of 98,995 women born between 1925 and 1950. From the women in the study we included those who did not have prevalent arterial disease or venous thromboembolism at baseline; thus 91,707 women were included in the study. Venous thromboembolism cases were self-reported during follow-up, and verified via specific mailings to medical practitioners or via drug reimbursements for anti-thrombotic medications. Hypertension, diabetes and dyslipidaemia were self-reported validated against drug reimbursements or specific questionnaires. Physical activity, and smoking were based on self-reports. Cox-models, adjusted for BMI and other potential risk-factors were used to determine hazard ratios for incident venous thromboembolism. RESULTS: During 1,897,960 person-years (PY), 1, 649 first incident episodes of thrombosis were identified at an incidence rate of 0.9 per 1000 PY. This included 505 cases of pulmonary embolism and 1144 cases of deep vein thrombosis with no evidence of pulmonary embolism. Hypertension, dyslipidaemia, diabetes, smoking and physical activity were not associated with the overall risk of thrombosis after adjustment for BMI. CONCLUSIONS: Traditional cardiovascular risk factors were not associated with the risk of venous thromboembolism after adjustment for BMI. Hypertension, dyslipidaemia and diabetes may not be risk-factors for venous thromboembolism.

Associations between smoking and blood-group, and the risk of dyslipidaemia amongst French women.

Dyslipidaemia is a major risk factor for cardio-vascular disease, as it promotes atherosclerosis. While cross-sectional studies have identified higher serum cholesterol amongst individuals with the A blood group, there is less evidence from prospective studies whether this translates into a higher risk of dyslipidaemia that requires treatment, nor if this genetic factor interacts with smoking status. This study aimed to prospectively determine potential associations between smoking, ABO blood groups, and risk of incident dyslipidaemia requiring treatment, and to assess associations over strata of blood ABO group. We assessed associations between blood ABO group, smoking and dyslipidaemia in 74,206 women participating in the E3N cohort. We included women who did not have cardiovascular disease at baseline. Logistic regression was used to determine associations between ABO group, smoking and prevalent dyslipidaemia at baseline. Cox proportional hazard models were then used to determine if blood ABO group and smoking were associated with the risk of incident dyslipidaemia, amongst women free of dyslipidaemia at baseline. At baseline 28,281 women with prevalent dyslipidaemia were identified. Compared to the O-blood group, the non-O blood group was associated higher odds of with prevalent dyslipidaemia (ORnon-O = 1.09 [1.06: 1.13]). Amongst the women free of dyslipidaemia at baseline, 6041 incident cases of treated dyslipidaemia were identified during 454,951 person-years of follow-up. The non-O blood groups were associated with an increased risk of dyslipidaemia when compared to the O-group (HRnon-O = 1.16 [1.11: 1.22]), specifically the A blood-group (HRA = 1.18 [1.12: 1.25]). Current smokers were associated with an increased risk of incident dyslipidaemia (HR smokers = 1.27 [1.16: 1.37]), compared to never-smokers. No evidence for effect modification between smoking and ABO blood group was observed (p-effect modification = 0.45), although the highest risk was observed among AB blood group women who smoked (HR = 1.76 [1.22: 2.55]). In conclusion, the non-O blood groups, specifically the A group were associated with an increased risk of dyslipidaemia. Current smokers were associated with a 30% increased risk of dyslipidaemia. These results could aid in personalised approaches to the prevention of cardiovascular risk-factors.

Experimental Assessment of Two Non-Contrast MRI Sequences Used for Computational Fluid Dynamics: Investigation of Consistency Between Techniques.

PURPOSE: Recent studies have noted a degree of variance between the geometries segmented by different groups from 3D medical images that are used in computational fluid dynamics (CFD) simulations of patient-specific cardiovascular systems. The aim of this study was to determine if the applied sequence of magnetic resonance imaging (MRI) also introduced observable variance in CFD results. METHODS: Using a series of phantoms MR images of vessels of known diameter were assessed for the time-of-flight and multi-echo data image combination sequences. Following this, patient images of arterio-venous fistulas were acquired using the same sequences. Comparisons of geometry were made using the phantom and patient images, and of wall shear stress quantities using the CFD results from the patient images. RESULTS: Phantom images showed deviations in diameter between 0 and 15% between the sequences, depending on vessel diameter. Patient images showed different geometrical features such as narrowings that were not present on both sequences. Distributions of wall shear stress (WSS) quantities differed from simulations between the geometries obtained from the sequences. CONCLUSION: In conclusion, choosing different MRI sequences resulted in slightly different geometries of the same anatomy, which led to compounded errors in WSS quantities from CFD simulation.

Modulation of sensory neuron potassium conductances by anandamide indicates roles for metabolites.

BACKGROUND AND PURPOSE: The endogenous cannabinoid anandamide (AEA) acts at cannabinoid (CB(1)) and vanilloid (TRPV(1)) receptors. AEA also shows antinociceptive properties; although the underlying mechanism for this is not fully understood, both CB(1) and TRPV(1) may be involved. Voltage-activated Ca(2+) channels in rat-cultured dorsal root ganglion (DRG) neurons are modulated by AEA. However, AEA in different populations of neurons enhanced or attenuated KCl-evoked Ca(2+) influx; these effects were linked with soma size. The aim of this study was to determine how AEA or its metabolites might produce these variable responses. EXPERIMENTAL APPROACH: The whole cell patch-clamp technique and fura-2 Ca(2+) imaging were used to characterize the actions of AEA on action potential firing and voltage-activated K(+) currents and to determine whether AEA metabolism plays any role in its effects on cultured DRG neurons. KEY RESULTS: AEA attenuated multiple action potential firing evoked by 300 ms depolarizing current commands in a subpopulation of DRG neurons. Application of 1 microM AEA attenuated voltage-activated K(+) currents and the recovery of KCl-evoked Ca(2+) transients. The insensitivity of these responses to the CB(1) receptor antagonist rimonabant (100 nM) and preincubation of DRG neurons with pertussis toxin suggested that these actions are not CB(1) receptor-mediated. Preincubating DRG neurons with the fatty acid amide hydrolase (FAAH) inhibitor phenylmethylsulphonyl fluoride (PMSF) attenuated the inhibitory actions of AEA on K(+) currents and Ca(2+) influx. CONCLUSION AND IMPLICATIONS: These data suggest that the products of AEA metabolism by FAAH contribute to the attenuation of K(+) conductances and altered excitability of cultured sensory neurons.

E-learning education solutions for caregivers in long-term care (LTC) facilities: new possibilities.

CONTEXT: Online learning (referred to as e-learning throughout this article) has proved to be a useful tool for delivering accessible and convenient education to busy clinical healthcare workers. The ABS Management Company specifically designed a program to provide nurses and caregivers with the necessary knowledge and skills to improve the quality of care and the quality of life for the geriatric population in long-term care (LTC) facilities. OBJECTIVES: The purpose of the "Online Solutions: Quality Education for Quality Care in Long-Term Care" program is to use new educational pedagogies and innovative ways to conceptualise and deliver healthcare education to meet the complex issues and concerns of caregivers in LTC facilities. METHODS: During the one-year period that data were collected for this study, 881 caregivers completed the eight (one-hour) modules in the program. Of these, 753 (85%) completed the optional assessment (both the pre and post tests) for one or more of the eight modules. Therefore, of the 881 employees who reviewed all eight modules (881x8 = 7048 modules), 1046 modules (15%) had both pre-post test data upon which to build the analysis. FINDINGS: Information from the evaluation revealed learner improvement in pre-post test scores in excess of 10%, suggesting an increase in new and relevant skills and knowledge related to abuse and neglect, elopement, infection control, nutrition and hydration, pressure ulcers, provision of basic care and restraints. Moreover, the data indicated a reduction in the use of restraints and occurrence of pressure ulcers, suggesting that learners applied new knowledge and skills in the workplace. Finally, staff turnover rates decreased more than 20% suggesting greater job satisfaction after participating in the program. CONCLUSIONS: The research findings point to an urgent and unmet need to provide more accessible just-in-time, just-for-you education programs for caregivers in LTC facilities to ensure quality and efficient services to residents and their families.

Modulation of glucose-6-phosphate dehydrogenase activity and expression is associated with aryl hydrocarbon resistance in vitro.

The mutagenic effect of environmental carcinogens has been well documented in animal models and in human studies but the mechanisms involved in preventing carcinogen insult have not been fully elucidated. In this study we examined the molecular and biochemical changes associated with carcinogen resistance in a series of aryl hydrocarbon-resistant MCF-7 cell lines developed by exposure to benzo[a]pyrene (BP). The cell lines were designated as AH(R40), AH(R100), and AH(R200) to denote their increasing fold resistance to BP compared with wild type cells. These cell lines were also resistant to another aryl hydrocarbon (AH), dimethylbenz[a]anthracene, but not to pleiotropic drugs (doxorubicin, vinblastine, and taxol). The resistant cell lines showed an increase in the level of the primary intracellular antioxidant, reduced glutathione, corresponding to increasing AH resistance. However, there was no change in glutathione reductase activity. The generation of reduced glutathione requires NADPH, and we therefore examined the activity and expression of the rate-limiting enzyme in NADPH production, glucose-6-phosphate dehydrogenase (G6PD). An increase in G6PD specific activity was associated with increasing aryl hydrocarbon resistance. This was due to an increased expression of G6PD in resistant cells, which was demonstrated by increases in both protein and mRNA levels. However, there was no increase in the transcription rate of G6PD in the resistant cell lines, indicating that the increase G6PD expression is due to a post-transcriptional modulation, which was confirmed by actinomycin D chase experiments. These results demonstrate that modulation of G6PD expression and activity is an important mechanism in AH resistance.

Dibenzoylmethane modulates aryl hydrocarbon receptor function and expression of cytochromes P50 1A1, 1A2, and 1B1.

The phytochemical dibenzoylmethane (DBM) has been shown to prevent polycyclic aromatic hydrocarbon (PAH)-induced tumorigenesis in rodents. However, the biochemical basis of this activity is unclear. We have therefore investigated the effects of DBM on the activity and expression of carcinogen-activating enzymes, the cytochromes P450 (CYP) 1A1, 1A2, and 1B1. Oral administration of DBM to female Sprague Dawley rats inhibited the increase in hepatic enzyme activity and mRNA levels of CYP1A1, 1A2, and 1B1 caused by the PAH 7,12-dimethylbenz[a]anthracene (DMBA). However, DBM administration alone caused an increase in both activity and expression in the liver, albeit to levels much lower than that induced by DMBA. To characterize the molecular mechanisms involved in this dual action of DBM, we examined the effects of DBM in vitro. In HepG2 human hepatoma cells, DBM inhibited DMBA- and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced enzyme activity and CYP1A1, 1A2, and 1B1 mRNA levels, whereas DBM itself induced activity and mRNA expression. Modulation of CYP1A1 expression by DBM occurred at the transcriptional level, as transient transfection assays demonstrated. Because the transcription of CYP1A1 is regulated by the aryl hydrocarbon receptor (AhR), we investigated the effect of DBM on AhR activation. DBM inhibited TCCD-induced DNA-binding of the AhR to the xenobiotic-responsive element (XRE) of CYP1A1 as measured by electrophoretic mobility shift assay. These data suggest that the chemopreventive activity of DBM results from its ability to affect Phase 1 enzyme expression by modulation of AhR function.

Vanadate stimulation of adenylyl cyclase: an index of tyrosine kinase vascular effects.

BACKGROUND: Beyond their mitogenic effects, hormones such as insulin, which activate receptor tyrosine kinases, regulate vascular tone. Further, we have demonstrated that receptor tyrosine kinase activation enhances adenylyl cyclase activation, a prominent mechanism that mediates vasodilation. However, whether tyrosine kinase-mediated human vascular responses parallel tyrosine kinase-mediated cellular effects on adenylyl cyclase activity is unknown. METHODS AND RESULTS: To assess tyrosine kinase-mediated vascular responses, vascular sensitivity to insulin was assessed with the dorsal hand vein linear variable differential transformer technique. Insulin infusion resulted in a dose-dependent relaxation in all subjects. Cellular responses were assessed by means of the insulinomimetic vanadate-mediated sensitization of vascular adenylyl cyclase activity. Vanadate stimulated a tyrosine kinase-dependent enhancement of adenylyl cyclase function in human and rat aortic vascular smooth muscle cells, human lymphocytes, and human aortic endothelial cells. Further, maximal insulin-mediated vasodilation was significantly positively correlated with maximal vanadate-mediated enhancement of human lymphocyte adenylyl cyclase activity. CONCLUSION: Insulin-mediated vasodilation is positively correlated with vanadate-mediated enhancement of adenylyl cyclase activity. Vanadate-mediated enhancement of adenylyl cyclase activity in lymphocytes may represent an index of tyrosine kinase-mediated vascular effects.

Posttranslational modification of Klebsiella pneumoniae flavodoxin by covalent attachment of coenzyme A, shown by 31P NMR and electrospray mass spectrometry, prevents electron transfer from the nifJ protein to nitrogenase. A possible new regulatory mechanism for biological nitrogen fixation.

A strain of Escherichia coli (71-18) that produces ca. 15% of its soluble cytoplasmic protein as a flavodoxin, the Klebsiella pneumoniae nifF gene product, has been constructed. The flavodoxin was purified using FPLC and resolved into two forms, designated KpFldI and KpFldII, which were shown to have identical N-terminal amino acid sequences (30 residues) in agreement with that predicted by the K. pneumoniae nifF DNA sequence. 31P NMR, electrospray mass spectrometry, UV-visible spectra, and thiol group estimations showed that the single cysteine residue (position 68) of KpFldI is posttranslationally modified in KpFldII by the covalent, mixed disulfide, attachment of coenzyme A. KpFldII was inactive as an electron carrier between the K. pneumoniae nifJ product (a pyruvate-flavodoxin oxidoreductase) and K. pneumoniae nifH product (the Fe-protein of nitrogenase). This novel posttranslational modification of a flavodoxin is discussed in terms of the regulation of nitrogenase activity in vivo in response to the level of dissolved O2 and the carbon status of diazotrophic cultures.

Variations of the median nerve in the carpal canal.

Eight hundred twenty-one median nerves were retrospectively and prospectively reviewed for variations during operations to treat carpal tunnel syndrome. Ninety-two cadaver median nerves were also dissected to document the incidence of variations within the carpal canal. The combined incidence of anomalies at operation (Lanz groups 1 to 4) was 9.8% and in the cadaver series 18%. The discrepancy reported by Poisel, 54% in the Lanz group 1 series, versus ours of 1.42% cannot be explained.