The experimental model of a cerebral missile injury developed by Crockard was used in three groups of Rhesus monkeys treated with mannitol. One group received mannitol 15 minutes after being injured with a BB pellet at 90 m/sec impact. Another group was wounded identically, but mannitol treatment was delayed until 1 hour after injury. The last group was wounded with the missile traveling at 180 m/sec, and mannitol was started 15 minutes after trauma. The data were contrasted with the results from the original model. After receiving mannitol, all groups showed marked improvement in mean blood pressure, cerebral perfusion pressure, cerebral blood flow, and cerebral metabolic rate of oxygen consumption out of proportion to the degree of reduction in intracranial pressure (ICP). The authors conclude that the therapeutic value of mannitol may, in some injuries, be directly related to its effects on blood flow and metabolism, as well as to its better known effects upon ICP. 相似文献
This study aimed to investigate dietary supplement use among Iranian adults in northern Iran. A cross-sectional study was undertaken on randomly selected men and women in Guilan province, northern Iran. The study population was parents of children and adolescents studying in schools. Totally, 1,425 women and 676 men were studied and data on age, body weight, height, educational level, and supplement use was gathered using a self-administrated questionnaire. These data showed that supplement use was related to sex, body mass index, and educational levels in both sexes. Most common supplements used in this population were Iron, calcium, multivitamin/multiminerals and fish oils. These results showed that 13.3, 3.4, 2.2, and 1.1 % of the study men used iron, calcium, multivitamin/multimineral, and fish oil, respectively. In women, 27.1, 10.7, 5.1, and 5.5 % used Iron, calcium, multivitamin/multimineral, and fish oil, respectively. More educated men and women and those with more healthy weight were more likely to use any dietary supplement than the less educated and overweight/obese men and women. This study showed that iron was the most common dietary supplement in this study middle aged Iranians. Using the other supplements was mostly related to age, educational level, and body weight status in this population. These data indicated that dietary supplement use was inversely related to some health-related behaviors and socioeconomic factors. 相似文献
OBJECT: The goal of this study was to determine the relationship between aneurysm size and the volume of subarachnoid hemorrhage (SAH). METHODS: One hundred consecutive patients who presented with acute SAH, which was diagnosed on the basis of a computerized tomography (CT) scan within 24 hours postictus and, subsequently, confirmed to be aneurysmal in origin by catheter angiography, were included in this study. The data were collected prospectively in 32 patients and retrospectively in 68. The volume of SAH on the admission CT scan was scored in a semiquantitative manner from 0 to 30, according to a previously published method. The mean aneurysm size was 8.3 mm (range 1-25 mm). The mean SAH volume score was 15 (range 0-30). Regression analysis revealed that a smaller aneurysm size correlated with a more extensive SAH (r(2) = 0.23, p < 0.0001). Other variables including patient sex and age, intraparenchymal or intraventricular hemorrhage, multiple aneurysms, history of hypertension, and aneurysm location were not statistically associated with a larger volume of SAH. CONCLUSIONS: Smaller cerebral aneurysm size is associated with a larger volume of SAH. The pathophysiological basis for this correlation remains speculative. 相似文献
OBJECTIVE: The treatment of giant intracranial aneurysms is a challenge because of the limitations and difficulty of direct surgical clipping and endovascular coiling. We describe the indications, surgical technique, and complications of saphenous vein extracranial-to-intracranial bypass grafting followed by acute parent vessel occlusion in the management of these difficult lesions. METHODS: Between January 1990 and December 1999, 29 patients with giant intracranial aneurysms underwent 30 saphenous vein bypass grafts followed by immediate parent vessel occlusion. There were 11 men and 18 women with a mean follow-up period of 62 months. Twenty-five patients harbored aneurysms involving the internal carotid artery, 2 had middle cerebral artery aneurysms, and 2 had aneurysms in the basilar artery. Serial cerebral or magnetic resonance angiograms were obtained to assess graft patency and aneurysm obliteration. RESULTS: All 30 aneurysms were excluded from the cerebral circulation, with 28 vein grafts remaining patent. Two patients had graft occlusions: one because of poor runoff and the other because of misplacement of a cranial pin during a bypass procedure on the contralateral side. Other surgical complications included one death from a large cerebral infarction, homonymous hemianopsia from thrombosis of an anterior choroidal artery after internal carotid artery occlusion, and temporary hemiparesis from a presumed perforator thrombosis adjacent to a basilar aneurysm. CONCLUSION: With appropriate attention to surgical technique, a saphenous vein extracranial-to-intracranial bypass followed by acute parent vessel occlusion is a safe and effective method of treating giant intracranial aneurysms. A high rate of graft patency and adequate cerebral blood flow can be achieved. Thrombosis of perforating arteries caused by altered blood flow hemodynamics after parent vessel occlusion may be a continuing source of complications. 相似文献
We assessed the long-term patency of kissing stent reconstruction of the aortoiliac bifurcation and identified variables that may influence it. We retrospectively reviewed our experience with stent-reconstruction procedures of the aortoiliac bifurcation from January 1998 through June 2005. The impact of demographic variables, vascular risk factors, disease location and characteristics, stent material and design, and stenting configuration on stent patency was assessed using univariate and multivariate analysis. In particular, we evaluated the effect of geometric mismatch between the protruding segment of the stents and the distal aortic lumen. Sixty-six patients underwent aortobi-iliac stent reconstruction. Indications were bifurcation or bilateral proximal iliac disease in 52 patients and unilateral ostial disease requiring contralateral protection in 14 patients. Limited disease (TASC A and B) was present in 40 limbs in 19 patients; extensive/diffuse disease (TASC C and D) was present in 78 limbs in 47 patients. Complete occlusions were present in 37 limbs in 28 patients (bilateral in nine patients). Self-expanding stents were used in 56 procedures and balloon-expandable stents in 10. Crossing configuration was used in 43 procedures, while abutting configuration was used in 23 procedures. Technical success was achieved in 62 patients (94%), with all four failures due to inability to cross a chronically occluded limb. Three of these patients underwent aortomono-iliac stenting with a crossover femoral-femoral bypass graft, with the remaining one opting for no further interventions. Median combined follow-up was 37 +/- 27 months (range 0-102). Hemodynamically significant restenosis developed in nine patients (14%). The management of restenosis was endovascular in eight patients and was successful in all (balloon dilation in four, restenting in three, thrombolysis and stenting in one) and operative in one patient who developed aortic occlusion and underwent aortobifemoral grafting. Survival table analysis showed primary and assisted patency rates at 4 years of 81% and 94%, respectively. The mortality rate during follow-up was 19 (cardiac cause in eight, pulmonary cause in three, and malignancy in five). Univariate analysis showed radial mismatch (aortic lumen dead space around the protruding segment of the stents), female gender, prior occlusion, and residual stenosis to be significant predictors of restenosis. Multivariate logistic regression analysis showed radial mismatch to be the only significant determinant of restenosis, although the statistical power of the model was limited by the small number of restenoses. Stent reconstruction of the aortoiliac bifurcation for occlusive disease is effective and durable, even with complex aortoiliac disease and long segment occlusions. Most restenoses are amenable to endovascular treatment, with excellent long-term assisted patency. Geometric variables related to individual aortic anatomy and disease pattern (patient-dependent) and stenting configuration (operator-dependent) may have an impact on long-term patency. 相似文献
Functional magnetic resonance imaging (fMRI) in resting state can be used to evaluate the functional organization of the human brain in the absence of any task or stimulus. The functional connectivity (FC) has non-stationary nature and consented to be varying over time. By considering the dynamic characteristics of the FC and using graph theoretical analysis and a machine learning approach, we aim to identify the laterality in cases of temporal lobe epilepsy (TLE).
Methods
Six global graph measures are extracted from static and dynamic functional connectivity matrices using fMRI data of 35 unilateral TLE subjects. Alterations in the time trend of the graph measures are quantified. The random forest (RF) method is used for the determination of feature importance and selection of dynamic graph features including mean, variance, skewness, kurtosis, and Shannon entropy. The selected features are used in the support vector machine (SVM) classifier to identify the left and right epileptogenic sides in patients with TLE.
Results
Our results for the performance of SVM demonstrate that the utility of dynamic features improves the classification outcome in terms of accuracy (88.5% for dynamic features compared with 82% for static features). Selecting the best dynamic features also elevates the accuracy to 91.5%.
Conclusion
Accounting for the non-stationary characteristics of functional connectivity, dynamic connectivity analysis of graph measures along with machine learning approach can identify the temporal trend of some specific network features. These network features may be used as potential imaging markers in determining the epileptogenic hemisphere in patients with TLE.
The tumor suppressor gene PTEN negatively regulates Akt, a downstream mediator phosphoinositol 3-kinase. Several studies have reported the role of PTEN gene in Akt downregulation and apoptosis induction in different cancers and cell lines. However, the role of loss of PTEN expression in Akt activation and spontaneous apoptosis in oral squamous cell carcinoma clinical specimens is not well established. 相似文献
International Urology and Nephrology - This study aimed at determining the feasibility of conducting a large-scale pragmatic effectiveness study on the implementation of multidisciplinary care... 相似文献