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91.
92.
BACKGROUND: Single-dose antimicrobial prophylaxis for major surgery is a widely accepted principle; recommendations have been based on laboratory studies and numerous clinical trials published in the last 25 years. In practice, single-dose prophylaxis has not been universally accepted and multiple-dose regimens are still used in some centres. Moreover, the principle has recently been challenged by the results of an Australian study of vascular surgery. The aim of this current systematic review is to determine the overall efficacy of single versus multiple-dose antimicrobial prophylaxis for major surgery and across surgical disciplines. METHODS: Relevant studies were identified in the medical literature using the MEDLINE database and other search strategies. Trials included in the review were prospective and randomized, had the same antimicrobial in each treatment arm and were published in English. Rates of postoperative surgical site infections (SSI) were extracted, 2 x 2 tables prepared and odds ratios (OR) [with 95% confidence intervals (95% CI)] calculated. Data were then combined using fixed and random effects models to provide an overall figure. In this context, a high value for the combined OR, with 95% CI > 1.0, indicates superiority of multiple-dose regimens and a low OR, with 95% CI < 1.0, suggests the opposite. A combined OR close to 1.0, with narrow 95% CI straddling 1.0, indicates no clear advantage of one regimen over another. Further subgroup analyses were also performed. RESULTS: Combined OR by both fixed (1.06, 95% CI, 0.89-1.25) and random effects (1.04, 95% CI, 0.86-1.25) models indicated no clear advantage of either single or multiple-dose regimens in preventing SSI. Likewise, subgroup analysis showed no statistically significant differences associated with type of antimicrobial used (beta-lactam vs other), blinded wound assessment, length of the multiple-dose arm (> 24 h vs 24 h or less) or type of surgery (obstetric and gynaecological vs other). CONCLUSIONS: Continued use of single-dose antimicrobial prophylaxis for major surgery is recommended. Further studies are required, especially in previously neglected surgical disciplines. 相似文献
93.
AI Qureshi JI Suarez PD Parekh G Sung R Geocadin A Bhardwaj RJ Tamargo JA Ulatowski 《Canadian Metallurgical Quarterly》1998,43(1):22-6; discussion 26-7
OBJECTIVE: Risk factors that predispose to the formation of multiple intracranial aneurysms, which are present in up to 34% of patients with intracranial aneurysms, are not well defined. In this study, we examined the association between known risk factors for cerebrovascular disease and presence of multiple intracranial aneurysms. METHODS: We reviewed the medical records and results of conventional angiography in all patients with a diagnosis of intracranial aneurysms admitted to the Johns Hopkins University hospital between January 1990 and June 1997. We determined the independent association between various cerebrovascular risk factors and the presence of multiple aneurysms using logistic regression analysis. RESULTS: Of 419 patients admitted with intracranial aneurysms (298 ruptured and 121 unruptured), 127 (30%) had multiple intracranial aneurysms. In univariate analysis, female gender (odds ratio [OR] = 1.9; 95% confidence interval [CI], 1.1-3.3) and cigarette smoking at any time (OR = 1.8; 95% CI, 1.1-3.0) were significantly associated with presence of multiple aneurysms. In the multivariate analysis, cigarette smoking at any time (OR = 1.7; 95% CI, 1.1-2.8) and female gender (OR = 2.1; 95% CI 1.2-3.5) remained significantly associated with multiple aneurysms. Hypertension, diabetes mellitus, and alcohol and illicit drug use were not significantly associated with presence of multiple aneurysms. CONCLUSION: Cigarette smoking and female gender seem to increase the risk for multiple aneurysms in patients predisposed to intracranial aneurysm formation. Further studies are required to investigate the mechanism underlying the association between cigarette smoking and intracranial aneurysm formation. 相似文献
94.
95.
L Zhang D Wang H Fischer PD Fan JH Widdicombe YW Kan JY Dong 《Canadian Metallurgical Quarterly》1998,95(17):10158-10163
Adeno-associated virus (AAV)-based vectors have been shown to be effective in transferring the cystic fibrosis gene (CFTR) into airway epithelial cells in animal models and in patients. However, the level of CFTR gene expression has been low because the vector cannot accommodate the CFTR gene together with a promoter. In this study, we described a strategy to reduce the size of the CFTR cDNA to allow the incorporation of an effective promoter with the CFTR gene into AAV vectors. We engineered and tested 20 CFTR mini-genes containing deletions that were targeted to regions that may contain nonessential sequences. Functional analyses showed that four of the shortened CFTRs (one with combined deletions) retained the function and the characteristics of a wild-type CFTR, as measured by open probability, time voltage dependence, and regulation by cAMP. By using an AAV vector with a P5 promoter, we transduced these short forms of CFTR genes into target cells and demonstrated high levels of CFTR expression. We also demonstrated that smaller AAV/CFTR vectors with a P5 promoter expressed the CFTR gene more efficiently than larger vectors or a vector in which CFTR gene was expressed from the AAV inverted terminal repeat sequence. The CFTR mini-gene with combined deletions was packaged into AAV virions more efficiently, generated higher titers of transducing virions, and more effectively transferred CFTR function into target cells. These new vectors should circumvent the limitations of AAV vector for CFTR expression. Our strategy also may be applicable to other genes, the sizes of which exceed the packaging limit of an AAV vector. 相似文献
96.
JP van Kats LM Sassen AH Danser MP Polak LK Soei FH Derkx MA Schalekamp PD Verdouw 《Canadian Metallurgical Quarterly》1996,117(5):891-901
1. The role of the renin-angiotensin system in the regulation of myocardial contractility is still debated. In order to investigate whether renin inhibition affects myocardial contractility and whether this action depends on intracardiac rather than circulating angiotensin II, the regional myocardial effects of systemic (i.v.) and intracoronary (i.c.) infusions of the renin inhibitor remikiren, were compared and related to the effects on systemic haemodynamics and circulating angiotensin II in open-chest anaesthetized pigs (25-30 kg). The specificity of the remikiren-induced effects was tested (1) by studying its i.c. effects after administration of the AT1-receptor antagonist L-158,809 and (2) by measuring its effects on contractile force of porcine isolated cardiac trabeculae. 2. Consecutive 10 min i.v. infusions of remikiren were given at 2, 5, 10 and 20 mg min-1. Mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), systemic vascular resistance (SVR), myocardial oxygen consumption (MVO2) and left ventricular (LV) dP/dtmax were not affected by remikiren at 2 and 5 mg min-1, and were lowered at higher doses. At the highest dose, MAP decreased by 48%, CO by 13%, HR by 14%, SVR by 40%, MVO2 by 28% and LV dp/dtmax by 52% (mean values; P < 0.05 for difference from baseline, n = 5). The decrease in MVO2 was accompanied by a decrease in myocardial work (MAP x CO), but the larger decline in work (55% vs. 28%; P < 0.05) implies a reduced myocardial efficiency ((MAP x CO)/MVO2). 3. Consecutive 10 min i.c. infusions of remikiren were given at 0.2, 0.5, 1, 2, 5 and 10 mg min-1. MAP, CO, MVO2 and LV dP/dtmax were not affected by remikiren at 0.2, 0.5 and 1 mg min-1, and were reduced at higher doses. At the highest dose, MAP decreased by 31%, CO by 26%, MVO2 by 46% and LV dP/dtmax by 43% (mean values; P < 0.05 for difference from baseline, n = 6). HR and SVR did not change at any dose. 4. Thirty minutes after a 10 min i.v. infusion of the AT1 receptor antagonist, L-158,809 at 1 mg min-1, consecutive 10 min i.c. infusions (n = 5) of remikiren at 2, 5 and 10 mg min-1 no longer affected CO and MVO2, and decreased LV dP/dtmax by maximally 27% (P < 0.05) and MAP by 14% (P < 0.05), which was less than without AT1-receptor blockade (P < 0.05). HR and SVR remained unaffected. 5. Plasma renin activity and angiotensin I and II were reduced to levels at or below the detection limit at doses of remikiren that were not high enough to affect systemic haemodynamics or regional myocardial function, both after i.v. and i.c. infusion. 6. Remikiren (10(-10) to 10(-4) M) did not affect contractile force of porcine isolated cardiac trabeculae precontracted with noradrenaline. In trabeculae that were not precontracted no decrease in baseline contractility was observed with remikiren in concentrations up to 10(-5) M, whereas at 10(-4) M baseline contractility decreased by 19% (P < 0.05). 7. Results show that with remikiren i.v., at the doses we used, blood pressure was lowered primarily by vasodilation and with remikiren i.c. by cardiac depression. The blood levels of remikiren required for its vasodilator action are lower than the levels affecting cardiac contractile function. A decrease in circulating angiotensin II does not appear to be the sole explanation for these haemodynamic responses. Data support the contention that myocardial contractility is increased by renin-dependent angiotensin II formation in the heart. 相似文献
97.
Fibro-osseous lesions of the sinonasal region are relatively frequent, but those strictly confined to the nasal cavity are rare. We report an atypical fibro-osseous lesion in the nasal cavity and describe its radiological features. The differential diagnosis is discussed. 相似文献
98.
This seminar reviews the aetiology, clinical presentation, approach to diagnosis, and management of immunocompetent adults with community-acquired pneumonia (CAP). Pneumonia is a common clinical entity, particularly among the elderly. A thorough understanding of the epidemiology and microbiology of CAP is essential for appropriate diagnosis and management. Although the microbiology of CAP has remained relatively stable over the last decade, there is new information on the incidence of atypical pathogens, particularly in patients not admitted to hospital, and new information on the incidence of pathogens in cases of severe CAP and in CAP in the elderly. Recent studies have provided new data on risk factors for mortality in CAP, which can assist the clinician in decisions about the need for hospital admission. The emergence of antimicrobial resistance in Streptococcus pneumoniae, the organism responsible for most cases of CAP, has greatly affected the approach to therapy, especially in those patients who are treated empirically. Guidelines for the therapy of CAP have been published by the American Thoracic Society, the British Thoracic Society, and, most recently, the Infectious Diseases Society of America. These guidelines differ in their emphasis on empirical versus pathogenic-specific management. 相似文献
99.
XF Zhao T Colaizzo-Anas NJ Nowak TB Shows RW Elliott PD Aplan 《Canadian Metallurgical Quarterly》1998,47(2):319-322
OBJECTIVE: We prospectively compared the ability of two techniques--bone scintigraphy with single-photon emission computed tomography (SPECT) of the chest and CT of the chest--to reveal potential osteosarcoma metastases of the lung. SUBJECTS AND METHODS: Our study included 27 patients with osteosarcoma who prospectively underwent both bone scintigraphy with SPECT of the chest and CT of the chest. The imaging results were compared with outcome or pathologic analysis of any lung lesions found. RESULTS: Eight (30%) of the 27 patients had pulmonary metastases. Four of these eight patients had positive results on both CT studies and bone SPECT studies, with additional lesions detected with bone SPECT in two of these four patients. The other four patients with pulmonary metastases had positive results on CT studies, whereas the results of bone SPECT studies remained negative. The results of bone SPECT studies were negative in the 19 patients without pulmonary metastases. CT, however, showed abnormalities in seven (37%) of the 19 patients, which were eventually attributed to benign conditions. CONCLUSION: Negative results on a bone SPECT study of the chest should not be used to exclude the possibility of lung metastases. However, if the results are positive, a bone SPECT study can be used to confirm abnormalities seen on CT scans and may also reveal subtle lesions missed on CT scans. 相似文献
100.
G Velikova RE Banks A Gearing I Hemingway MA Forbes SR Preston NR Hall M Jones J Wyatt K Miller U Ward J Al-Maskatti SM Singh PJ Finan NS Ambrose JN Primrose PJ Selby 《Canadian Metallurgical Quarterly》1998,77(11):1857-1863
The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 48 patients with colorectal cancer before treatment, and their relation to clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with colorectal cancer in comparison with a group of healthy subjects (P < 0.00001). Levels of circulating ICAM-1 and VCAM-1 were increased both in patients with local and those with metastatic disease. Although elevated in some patients soluble E-cadherin and E-selectin concentrations were not significantly elevated compared with the control group (P = 0.71 and P = 0.052 respectively). The levels of circulating ICAM-1 were significantly correlated with those of VCAM-1 and E-selectin. A correlation was also found between the serum concentrations of E-selectin and ICAM-1 and alkaline phosphatase, total white cell count and platelet count. VCAM-1 was positively correlated with age and negatively with degree of tumour differentiation and haemoglobin concentration. The biological implications and possible clinical relevance of these findings are discussed. 相似文献