大白鼠皮肤Ⅱ度、Ⅲ度碱烧伤模型复制

目的 根据大白鼠皮肤碱烧伤创面早期病理组织学观察复制Ⅱ、Ⅲ度碱烧伤模型,研究碱烧伤的临床治疗.方法 Wistar纯种健康大白鼠20只,以不同浓度2mol/l、2.5mol/l、5mol/lNaOH,作用时间分别为30秒、45秒、60秒、75秒,涂抹于脱毛后的表皮.结果 2mol/L(60s)、2.5mol/L(45s),5mol/L(30s)即可直接造成Ⅱ度～深Ⅱ度烧伤;2mol/L(75s)、2.5mol/L(60s)、5 mol/L(45s)即可造成Ⅲ度烧伤,其烧伤深度与NaOH溶液浓度和作用时间呈正比.结论 Ⅱ度、Ⅲ度碱烧伤均为渐进性烧伤,与文献中介绍的潜拙样损伤似乎不同.另外,不同浓度NaOH溶液在相同时间对皮肤组织的损伤及同一浓度NaOH溶液在不同时间对大白鼠皮肤的损伤病理学变化均有差异.     

Aortic prosthetic ring annuloplasty: a useful adjunct to a standardized aortic valve-sparing procedure?

OBJECTIVE: Dilation of aortic annulus, sinuses of Valsalva, and sinotubular junction (STJ) diameters are the characteristic lesions of aortic root aneurysm. The remodeling technique reduces STJ diameter and creates three neosinuses of Valsalva. Alternatively, the reimplantation technique reduces both annulus and STJ diameters to the detriment of aortic root dynamics. Although the remodeling technique is recognized as the most physiological valve-sparing procedure, aortic annulus dilation may jeopardize its results. A standardized approach that combines an external subvalvular aortic prosthetic ring annuloplasty with the remodeling technique is suggested. METHODS: Eighty-three patients underwent an elective aortic root remodeling procedure, either isolated (group 1, n=34) or combined with an external subvalvular aortic prosthetic ring annuloplasty (group 2, n=49). Preoperative aortic regurgitation was 1.59+/-1.1 (group 1) and 1.97+/-1.3 (group 2) (NS). The aortic annulus was more dilated in group 2 than in group 1 (27+/-2.77 mm vs 26.4+/-2.3 mm, p<0.01). Residual aortic regurgitation > or =grade II was the conversion criteria for aortic valve replacement. RESULTS: Operative mortality was 3.6% (n=3). Intraoperative conversion for valve replacement was 32.7% in group 1 (n=11) versus 4.2% in group 2 (n=2) (p<0.001). In group 1, preoperative annulus diameter was larger for converted than for valve-spared patients (27.6+/-1.7 mm vs 25.2+/-1.5 mm, p<0.02). In group 2, implanted aortic ring significantly reduced annulus diameter (20.6+/-1.8 mm) without significant aortic valve gradient (8.3+/-3 mmHg). Follow-up was 17.2+/-13.4 months (group 1) and 10.41+/-7.95 months (group 2). Reoperation for recurrent aortic regurgitation was 13% in group 1 (n=3) versus 4.2% in group 2 (n=2). Echocardiographic follow-up found residual aortic regurgitation < or =grade I in 17 patients in group 1 (90%) versus 43 patients in group 2 (95.5%) and of grade II in two patients in group 1 (10%) and two patients in group 2 (4.5%). CONCLUSION: The addition of external aortic prosthetic ring annuloplasty improves the remodeling technique's operative reproducibility and short-term results. Therefore, its use as a systematical adjunct to the remodeling procedure is suggested. However, further long-term evaluation comparing this valve-sparing procedure to composite graft replacement should define the best surgical strategy for aortic root aneurysm.     

Resolution of homonymous visual field loss documented with functional magnetic resonance and diffusion tensor imaging.

A 68-year-old man developed right homonymous hemianopic paracentral scotomas from acute infarction of the left extrastriate area. He was studied over the ensuing 12 months with visual fields, conventional MRI, functional MRI (fMRI), and diffusion tensor imaging (DTI). As the visual field defect became smaller, fMRI demonstrated progressively larger areas of cortical activation. DTI initially showed that the lesioned posterior optic radiations were completely interrupted. This interruption lessened in time and had disappeared by one year after onset. fMRI and DTI are innovative measures to follow functional and structural recovery in the central nervous system. This is the first reported application of these imaging techniques to acute cerebral visual field disorders.     

Risk factors profile and clinical outcome of ischemic stroke patients admitted in a Department of Internal Medicine and classified by TOAST classification.

AIM: A classification of ischemic stroke subtypes tailored for individual patients is hard to achieve. In 1993, the Trial of Org 10172 in Acute Stroke Treatment (TOAST) group developed a new system to classify the subtypes of ischemic stroke. In our study we applied the TOAST classification to a group of consecutive patients affected by ischemic stroke, to evaluate outcome and factors associated to each stroke subtype. METHODS: To evaluate the prognosis and the associated factors of ischemic stroke subtypes, we classified according to the TOAST classification a cohort of 159 consecutive patients affected by an acute ischemic stroke. We evaluated neurological deficit at admission by Scandinavian Stroke Scale and scored disability at discharge and 6 months after discharge using the Rankin disability scale. We determined 30 days survival and anamnestically evaluated major vascular risk factors. RESULTS: Patients with cardioembolic stroke and stroke of undetermined etiology had a greater neurological deficit on admission and the worst prognosis either in terms of disability or mortality. Lacunar stroke had the least neurological deficit at admission and the best prognosis. Hypercholesterolemia and smoking were more frequent among patients with large artery atherosclerotic stroke. Hypertension, a history of transient ischemic attack and diabetes were more frequent among patients with lacunar stroke. A weak association with hypertension and smoking was observed for cardioembolic stroke. CONCLUSIONS: The TOAST classification is useful in the clinical setting because it identifies ischemic stroke subtypes with different prognosis and with a different profile of associated factors.