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排序方式: 共有473条查询结果,搜索用时 15 毫秒
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DANIELA POLI M.D. GREGORY YH LIP M.D. EMILIA ANTONUCCI M.D. ELISA GRIFONI M.S. DEIRDRE LANE Ph.D. 《Journal of cardiovascular electrophysiology》2011,22(1):25-30
Stroke Risk Stratification . Introduction: Appropriate stroke risk stratification is essential to ensure suitable tailoring of antithrombotic therapy. The objective of this study was to assess the predictive value of stroke risk classification schemes and to identify patients with atrial fibrillation (AF) who are at substantial risk of stroke despite optimal anticoagulant therapy, in a “real world” consecutive elderly AF cohort. Methods: Six hundred and sixty‐two consecutive AF patients (mean [SD] age 74 [7.7] years; 36.1% female) referred to the Anticoagulation Clinic of the Azienda Ospedaliera Careggi of Florence, Italy, were included and followed‐up for a mean 3.6 ± 2.7 years for the incidence of thromboembolic (TE) events. The ability of the new CHA2DS2‐VASc schema to predict TE was compared with other contemporary stroke risk schema (including CHADS2, NICE 2006, ACC/AHA/ESC 2006, and ACCP 2008), by determining the c‐statistic. Results: Univariate predictors of TE events were female gender (odds ratio 1.9; 95%CI [confidence intervals] 1.01–3.70) and previous stroke/transient ischemic attack (TIA)/TE (OR 5.6; 95%CI 2.70–11.45), although after adjustment only previous stroke/TIA/TE was an independent predictor of TE (OR 5.5; 95%CI 2.68–11.31; P = 0.0001). All stroke risk schema had modest discriminating ability, with c‐statistics ranging from 0.54 (atrial fibrillation investigators [AFI]) to 0.72 (CHA2DS2‐VASc). The CHADS2 and CHA2DS2‐VASc schemes having the best c‐statistics (0.717 and 0.724, respectively) with significant discriminating value between risk strata (both P < 0.001). The proportion of patients assigned to individual risk categories varied widely across the schema, with those categorized as “moderate‐risk” ranging from 5.3% (CHA2DS2‐VASc) to 49.2% (CHADS2‐classical). Conclusion: In this “real world” cohort, current published risk schemas have modest predictive ability, with the CHADS2 and CHA2DS2‐VASc schemes having the best predictive value for thromboembolism. Future trials could assess the value of alternative strategies for thromboprophylaxis in high‐risk anticoagulated patients identified by these schemes. (J Cardiovasc Electrophysiol, Vol. 22, pp. 25‐30, January 2011) 相似文献
93.
JOSEPH F. STANDING PhD GREGORY B. HAMMER MD † WAI JOHNN SAM PhD ‡ DAVID R. DROVER MD § 《Paediatric anaesthesia》2010,20(1):7-18
Objectives: Although remifentanil has been used to induce hypotension during surgery in infants, no pharmacokinetic–pharmacodynamic (PKPD) model exists for its quantitative analysis. Our aim was to determine the quantitative relationship between whole blood remifentanil concentration and its hypotensive effect during surgery in infants.
Methods/materials: We studied seven infants (age 0.3–1 year) who underwent cranioplasty surgery and received remifentanil delivered by a computer-controlled infusion pump during the maintenance of anesthesia. Arterial blood samples to determine remifentanil concentration and mean arterial blood pressure (MAP) measurements were collected. A simultaneous PKPD mixed-effects model was built in NONMEM.
Results: A total of 77 remifentanil concentrations and 185 MAP measurements were collected. Remifentanil pharmacokinetics was described with a two-compartment model, parameter estimates were 2.99 l·min−1 ·70 kg−1 for clearance and 16.23 l·70 kg−1 for steady state volume of distribution. Mean baseline MAP was 69.7 mmHg and was decreased as per clinical requirements. A sigmoidal E max model driven by an effect compartment described the decrease in MAP, with an estimated concentration to decrease MAP by half (EC50 ) being 17.1 ng·ml−1 .
Conclusions: Remifentanil is effective in causing hypotension. The final model predicts that a steady state remifentanil concentration of 14 ng·ml−1 would typically achieve a 30% decrease in MAP. 相似文献
Methods/materials: We studied seven infants (age 0.3–1 year) who underwent cranioplasty surgery and received remifentanil delivered by a computer-controlled infusion pump during the maintenance of anesthesia. Arterial blood samples to determine remifentanil concentration and mean arterial blood pressure (MAP) measurements were collected. A simultaneous PKPD mixed-effects model was built in NONMEM.
Results: A total of 77 remifentanil concentrations and 185 MAP measurements were collected. Remifentanil pharmacokinetics was described with a two-compartment model, parameter estimates were 2.99 l·min
Conclusions: Remifentanil is effective in causing hypotension. The final model predicts that a steady state remifentanil concentration of 14 ng·ml
94.
Atrial Fibrillation Associated Genetic Variants and Left Atrial Histology: Evaluation for Molecular Sub‐Phenotypes 下载免费PDF全文
JASON D. ROBERTS M.D. M.A.S. JINGKUN YANG B.S. RACHEL A. GLADSTONE B.A. JAMES LONGORIA M.D. ISAAC R. WHITMAN M.D. THOMAS A. DEWLAND M.D. CAROLINE MILLER M.Sc. D.I.C. ANATALIA ROBLES B.A. ANNIE POON Ph.D. BEVERLY SEILER R.N. WILLIAM A. LAFRAMBOISE Ph.D. JEFFREY E. OLGIN M.D. PUI‐YAN KWOK M.D. Ph.D. GREGORY M. MARCUS M.D. M.A.S. 《Journal of cardiovascular electrophysiology》2016,27(11):1264-1270
95.
HUNG-FAT TSE M.D. Ph .D. SONGYAN LIAO M.D. CHUNG-WAH SIU M.B.B.S. LIU YUAN M.D. JOHN NICHOLLS M.D. † GEORGE LEUNG Ph .D.‡ TED ORMSBY‡ GREGORY K. FELD M.D. § CHU-PAK LAU M.D. 《Pacing and clinical electrophysiology : PACE》2009,32(2):201-208
Background: Transcatheter microwave ablation is a novel technique for treating cardiac arrhythmias. Methods: We investigated the effects of catheter temperature, application duration, and antenna length on lesion dimensions during catheter‐based microwave ablation. In a swine thigh muscle preparation, microwave was delivered at targeted temperatures of 60°C (n = 18), 70°C (n = 27), 80°C (n = 43), or 90°C (n = 18) for 120 seconds with 10‐mm antenna; and at targeted temperatures of 80°C for 120 seconds (n = 22), 150 seconds (n = 18), 180 seconds (n = 18), 210 seconds (n = 18), and 240 seconds (n = 17) with 20‐mm antenna using 10 F catheter (MedWaves, San Diego, CA, USA) during parallel orientation. Conventional radiofrequency ablation (RF) using a 4‐mm tip electrode was performed as control. Results: With 120‐second energy applications, lesion length and depth were significantly larger with targeted temperatures of 80°C and 90°C than 60°C (P< 0.05). Furthermore, lesion depth and width, but not length, were significantly increased by prolonging energy application duration from 120 to 240 seconds at targeted temperature of 80°C (P< 0.05). Compared to RF, microwave lesions were significantly longer but had comparable depth and width. A 20‐mm microwave antenna produced longer lesions than either a 10‐mm antenna or RF ablation catheter. Multivariate analysis demonstrated that targeted temperature ≥80°C, application duration ≥150 seconds, and use of 20‐mm antenna were independent predictors for lesion depth and width (P< 0.05). Surface dessication was observed in 4/18 (22%) lesions at 90°C, as compared with 1/136 (0.7%) at 80°C targeted tip temperature (P < 0.05). Conclusions: This study demonstrated that lesions size with transcatheter microwave ablation can be controlled by adjusting targeted temperature, energy application duration, and antenna length. A targeted temperature of 80°C for more than 150 seconds should provide optimal lesion dimensions and lower risk of surface dessication or charring. 相似文献
96.
TREVOR M. SOERGEL MICHAEL O. KOCH RICHARD S. FOSTER RICHARD BIHRLE GREGORY WAHLE THOMAS GARDNER SIN-HO JUNG 《The Journal of urology》2001,166(6):2198-2201
PURPOSE: We determined how prostate specific antigen (PSA) doubling time changed with time and whether an early measure of doubling time would accurately predict long-term PSA values and clinical outcome in a cohort of patients followed expectantly after radical prostatectomy. MATERIALS AND METHODS: We analyzed data on 121 patients with PSA recurrence after radical retropubic prostatectomy. Group and individual analyses were performed on 60 patients who met study inclusion criteria. PSA doubling time was calculated and a curve was plotted using logarithmic transformation with linear regression and least squares analysis. In analysis 1 patients were placed into 3 subgroups according to doubling time. Doubling time was calculated per subgroup and the slopes of the aggregate curves were compared to determine how doubling time changed with time. In analysis 2 we calculated early doubling time per patient using only the initial 2 detectable PSA values and compared it with eventual doubling time in each using all PSA values. In addition, we analyzed how doubling time correlated with the clinical course. RESULTS: Using the group methodology there was no statistically significant acceleration or deceleration with time in doubling time slope in any of the 3 subgroups. On individual analysis we noted a weak correlation of early with eventual doubling time (correlation coefficient 0.69, p = 0.01). In 88% of patients eventual doubling time was not within 10% of early doubling time. Metastasis developed in 60% of patients with an eventual DT of 0 to 6 months, while 80% with an eventual doubling time of 6 to 12 months had no evidence of local or metastatic disease. No patients with an eventual doubling time of greater than 12 months have had metastatic disease and only 4 (16%) had local recurrence, which was treated with radiation therapy. In 8 of the 14 patients (23%) with local recurrence or metastatic disease early doubling time predicted eventual doubling time. Early doubling time was more rapid and slower than eventual doubling time in 5 and 1, respectively, of the remaining cases, which would have placed them in a different subgroup. CONCLUSIONS: On group analysis PSA doubling time appeared to be constant with time and there was no evidence that it accelerated with time in our dataset of PSA recurrence after radical prostatectomy. On individual analysis early doubling time showed a weak but statistically significant correlation with eventual doubling time. However, there was significant inaccuracy when predicting PSA doubling time based on early PSA values in individuals. Generally early projections of doubling time tend to over predict tumor biological aggressiveness, that is local recurrence or metastasis. A need remains for more accurate predictors of the rate of disease progression at initial PSA recurrence to determine accurately early in the clinical course the patients who may benefit from additional therapy. Currently no patient in our study has died of prostate cancer. 相似文献
97.
Taurine Failed to Protect against the Embryotoxic Effects ofIsotretinoin in the Rat AGNISH, N. D., RUSIN, G., AND DINARDO,B. (1990). Fundam. Appl. To.xicol. 15, 249257. Experimentalevidence exists to indicate that retinoids may act as detergentsto disrupt biological membranes. Taurine, an amino sulfonicacid, has been shown to possess membrane-stabilizing and cytoprotectiveproperties. This study was undertaken to test whether taurinecoadministered with isotretinoin might be able to protect againstthe teratogenic effects of the retinoid. Our study failed tofind any support for this speculation. Whether challenged againsta 75 (mildly teratogenic) or 150 (very teratogenic) mg/kg/daydose of isotretinoin, taurine for the most part worsened theretinoid embryotoxicity. While in a few combinations taurinedecreased the re-sorption or malformation rate associated withisotretinoin, the decrease was, at best, marginal. In no casewas taurine able to decrease these rates to those noted in thecontrols. 相似文献
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ROTH ANNETTE C.; HERKERT GREGORY E.; BERCZ JENO P.; SMITH M. KATE 《Toxicological sciences》1987,9(4):668-677
Sodium nitrite administered in the drinking water to Long-Evansrats during pregnancy and lactation severely affected erythropoieticdevelopment, growth, and mortality in their offspring. Pregnantrats were maintained throughout gestation on 0.5, 1, 2, or 3g NaNO2/liter. There were no significant differences betweentreated and control litters at birth. Thereafter, pups of treateddams on 2 and 3 g NaNO2/liter gained less weight, progressivelybecame severely anemic, and began to die by the third week postpartum.By the second week postpartum, hemoglobin levels, RBC counts,and mean corpuscular volumes of these pups were all drasticallyreduced compared to controls. Blood smears showed marked anisocytosisand hypochromasia. Gross chylous serum lipemia and fatty liverdegeneration were noted. Histopathology demonstrated cytoplasmicvacuolization of centrilobular hepatocytes and decreased hematopoiesisin bone marrow and spleen. Administration of 1 g NaNO2/literresulted in hematological effects but did not affect growthor mortality. NaNO2(0.5 g/liter) was at or near the no observedeffect level. Cross-fostering indicated that treatment dunngthe lactational period was more instrumental in producing lesionsthan treatment during the gestational period. The data presentedare consistent with the lactational induction of severe irondeficiency in the neonate. 相似文献