脑缺血疾患颈动脉彩色多普勒超声检查

目的 :探讨二维彩色多普勒超声及彩色血管三维超声在颈动脉疾病的诊断价值。材料方法 :疑为缺血性脑卒中患者 80例 ,行颈动脉彩色多普勒超声检查 ,其中 2 8例同时做彩色血管三维超声成像 ,5 5例经临床、CT、MRI证实为脑梗死。结果 :①本组 5 5例脑梗死 ,彩色多普勒超声发现 4 9例颈动脉粥样硬化斑。②有脑梗死的彩色血管三维血流图呈“串珠”状 ,而非脑梗死的彩色血管三维血流图呈连续“圆锥”状。结论 :彩色多普勒超声诊断颈动脉粥样硬化有良好的价值 ,三维彩超是二维彩色多普勒超声的有益补充。     

Malodour in denture wearers: an ill-defined problem

Denture plaque has not been studied to the same extent as dental plaque, and although there are many similarities in microbial composition, there are some significant differences. Denture-induced stomatitis is associated with poor denture hygiene, a more acidogenic plaque and the presence of Candida albicans . Obligate Gram-negative anaerobic micro-organisms, although present in denture plaque, have rarely been specifically investigated. Opportunist pathogens including coliforms and staphylococci have been isolated from dentures. Teeth adjacent to partial dentures are more susceptible to caries and periodontal diseases, perhaps due to an increased plaque buildup at the prosthesis/tooth interface. Little work has been published on malodour associated with dentures. The inert material provides a substratum for the plaque biofilm, which encompasses a range of odour-producing species. The microbiology of the tongue in denture wearers has not been specifically studied. Thus the nature, origin and extent of malodour in denture wearers is ill-defined, but many species capable of producing malodorous compounds are present. The wide age and health range presented by denture wearers further confounds investigation. There is a need for further work in the area, both for cosmetic- and health-associated reasons in the increasing elderly population.     

Vascular Centerline Extraction in 3D MR Angiograms for Phase Contrast MRI Blood Flow Measurement

The accuracy of 2D phase contrast (PC) magnetic resonance angiography (MRA) depends on the alignment between the vessels and the imaging plane. PC MRA imaging of blood flow is challenging when the flow in several vessels is to be evaluated with one acquisition. For this purpose, semi-automatic determination of the plane most perpendicular to several vessels is proposed based on centerlines extracted from 3D MRA. Arterial centerlines are extracted from 3D MRA based on iterative estimation-prediction, multi-scale analysis of image moments, and a second-order shape model. The optimal plane is determined by minimizing misalignment between its normal vector and the centerlines’ tangent vectors. The method was evaluated on a phantom and on 35 patients, by seeking the optimal plane for cerebral blood flow quantification simultaneously in internal carotids and vertebral arteries. In the phantom, difference of orientation and of height between known and calculated planes was 1.2° and 2.5 mm, respectively. In the patients, all but one centerline were correctly extracted and the misalignment of the plane was within 12° per artery. Semi-automatic centerline extraction simplifies and automates determination of the plane orthogonal to one vessel, thereby permitting automatic simultaneous minimization of the misalignment with several vessels in PC MRA.     

原发性高血压病患者颈动脉粥样硬化程度与血清胆红素水平的相关性研究

目的 探讨高血压病患者颈动脉粥样硬化程度与血清胆红素水平的关系.方法 158 例高血压病患者行双侧颈动脉超声多普勒检查,根据检测结果分为颈动脉粥样硬化组和正常颈动脉组.记录各组年龄、性别、体重指数、吸烟史、糖尿病史和血压,测定血清总胆红素及其他生物化学指标.结果 颈动脉粥样硬化组的血清总胆红素水平(8.37±3.53)μmol/L显著低于正常颈动脉组(14.53±4.61)μmol/L(P＜0.05).多因素回归分析显示低胆红素血症与颈动脉粥样硬化呈显著正相关(χ2wald=4.41,P=0.029,OR=3.72).结论 低胆红素血症是高血压病患者发生颈动脉粥样硬化的独立危险因素.     

The carotid endarterectomy: Experience with 260 cases and discussion of the indications

Summary During 1978 to 1989, 235 patients were operated upon with 260 procedures for cervical carotid endarterectomy. The patients were classified according to the presence or absence of ischaemic symptomatology, and for symptomatic patients, according to the reversibility or persistance of ischaemic symptoms. So the selection of patients was: reversible ischaemia 46%, stroke 29%, asymptomatic patients 25%. In the stroke group, no patient was operated on as an emergency, the endarterectomy was only performed after stabilization of the clinical state. Three subgroups were included in patients operated on for asymptomatic carotid stenosis: casual discovery 40%, treatment of the second carotid artery (previous endarterectomy for symptomatic contralateral stenosis) 34%, and treatment of the second carotid artery (previous ECIC by-pass for contralateral carotid occlusion) 26%. All patients were operated upon after angiographic exploration (femoral catheterisation in most cases), and after cerebral CT scan. The surgical technique included general anaesthesia, systematic shunting, endarterectomy after longitudinal arteriotomy, closure without patch. The operating microscope has been used since 1985.The surgical results were studied in terms of uneventful postoperative course (87%), reversible complications (8%) and long lasting complications (5%). The long lasting complications were of local origin (1%), of neurological origin (2%), of general origin (1%). Overall the operative outcome at 6 months was: return to previous clinical state 95%, neurological sequelae 2%, death 3%. In the patients operated on for asymptomatic carotid stenosis the overall outcome was: previous clinical state 97%, death 3%. The legitimacy of carotid endarterectomy procedure is discussed in relation to some recent pertinent literature.     

Application of technetium-99m hexamethylpropylene amine oxime single-photon emission tomography to neurologic prognosis in patients undergoing urgent carotid surgery

In this study we aimed to work out a quantitative prognostic index for preoperative assessment of brain technetium-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission tomography (SPET) in patients referred for urgent carotid endarterectomy due to acute obstructive disease of the internal carotid artery (ICA) and neurological deficit. To this end we compared data from preoperative SPET studies with the postinterventional changes in neurological status in 20 patients (17 males, three females; mean age 53 years, SD 4 years) with acute ischaemic cerebral disorders induced by obstruction of the ICA. Carotid obstruction was diagnosed by ultrasound B-mode study. All patients underwent urgent carotid endarterectomy from the ICA. Patients were divided into two groups in accordance with the results of postoperative follow-up: group A comprised patients with significant (more than 3 points) postoperative improvement in neurological condition as quantified by the Canadian Neurological Scale (11 patients); group B consisted of patients with minimal improvement or deterioration (nine, three of whom died). All patients were studied preoperatively by^99mTc-HMPAO SPET. The volume of nonperfused tissue (VS, cm³) was quantified using the Mountz technique. Hypoperfused volume (V _hypoperf, cm³) in the affected hemisphere was calculated as the total volume of voxels with^99mTc-HMPAO uptake <90% of the contralateral symmetric voxels. Discriminant prognostic function was calculated by discriminant analysis as:PF = 0.072×VS + 29.46×(VS/V _hypoperf). Patients with preoperativePF values <8.20 demonstrated postoperative improvement in neurological status, while the group withPF>8.90 comprised patients who demonstrated minimal improvement or deterioration. PF values in the range 8.20–8.90 carried an indefinite prognosis. We conclude that the preoperative^99mTc-HMPAO SPET can be used for the selection of patients in whom improvement in neurological status may be expected after urgent surgical correction of acute extracranial obstruction of the ICA.     

Sucrose-dependent accumulation of oral streptococci and their adhesion-defective mutants on saliva-coated hydroxyapatite

The adhesion and accumulation of oral streptococci on saliva-coated hydroxyapatite was examined in strains representing species that appear in initial plaque ( Streptococcus sanguise FC1 and Streptococcus oralis C5) and in more mature plaque ( Streptococcus gordonii G9B). Washed cells of strains FC1 and C5 did not attach better to saliva-coated hydroxyapatite than did strain G9B, suggesting that the degree of initial adhesiveness does not alone account for the temporal appearance of these bacteria in dental plaque. Growing cells of each strain were also examined for their ability to accumulate on saliva-coated hydroxyapatite. The addition of sucrose to the medium promoted the accumulation of strain G9B more than it promoted the accumulation of strains FC1 and C5. Sucrose also enhanced the accumulation of adhesion-defective mutants of each strain to levels similar to those of the respective parent strains. These results suggest that sucrose-dependent accumulation may facilitate the colonization of the tooth surface by these species of oral streptococci when adhesion is limited by reduced bacterial adhesiveness or limited pellicle-binding sites.     

The effects of a 0.12% chlorhexidine-digluconate-containing mouthrinse versus a placebo on plaque and gingival inflammation over a 3-month period

Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth.     

颈动脉粥样硬化斑块中COX-2、mPGES-1表达及塞来昔布对其的影响作用

目的探讨兔颈动脉粥样硬化斑块中环氧化物酶-2（COX-2）、诱导型前列腺素合成酶-1（mPGES-1）的表达机制及塞来昔布对其表达的影响。方法采用32只雄性新西兰大白兔．其中正常对照组8只（A组），另24只将特制的硅橡胶圈置于兔右侧颈动脉。术后给予1％高胆固醇喂养14d，建立兔颈动脉粥样硬化性狭窄动物模型，将模型兔随机分为颈动脉狭窄无干预组（B组1、小剂量塞来昔布治疗组（15mg／kg，C组），大剂量塞来昔布治疗组（35mg／kg，D组），每组各8只。治疗4周后取双侧颈动脉并分为平等2段，分别行半定量逆转录聚合酶链反应（RT—PCR）及Western blot法测定颈动脉斑块干预后COX-2及mPGES-1的表达。结果与A组比较,B、C、D组颈动脉粥样硬化模型兔的斑块中COX-2及mPGES．1表达增高，差异具有显著性（P〈0．05）；与B组比较，C、D组颈动脉斑块的C0X-2及mPGES．1表达显著下调，差异有显著性（P〈0．051。结论在颈动脉粥样硬化斑块的病理过程中炎症反应可能起着主导作用。塞来昔布干预可抑制COX-2及mPGES—1的表达，减缓颈动脉粥样硬化的进展。     

Laser irradiation and balloon dilatation in experimental transluminal angioplasty

Percutaneous transluminal balloon angioplasty (PTA) is being currently used in patients with coronary artery disease. Laser irradiation (LI) has been effective in vaporizing atherosclerotic plaques. The purpose of this work was twofold: to compare PTA and LI techniques in the recanalization of experimental obstructive arterial lesions, and to evaluate the possibility of reducing the failures and local complications and increasing the success rate of PTA by the combined use of LI. Atherosclerotic iliac stenoses were induced in 27 rabbits; lesions were evaluated angiographically before and after intervention and were studied histologically and by electron microscopy. Argon-ion LI delivered through microlens-tip optic fibers reduced the stenotic area from 64.2 +/- 21.8% to 40.3 +/- 10.7% (n = 10, P less than .01) and PTA from 60.7 +/- 15.9% to 30.4 +/- 7.7% (n = 9, P less than .01). However, percentage reduction was higher in PTA-treated stenoses (48.4 +/- 10.1% vs 34.5 +/- 13.5%, P less than .0125). In eight more rabbits, low power LI (4.55 +/- 1.25 J) was delivered after PTA in dilated segments. Post-PTA LI further decreased stenoses (from 31.2 +/- 7.8% to 29.1 +/- 8.1%, P less than .0125); laser-irradiated segments showed diffuse carbonization of the disrupted intimal layer. The normalized transtenotic pressure gradient decreased significantly in all groups: LI reduced the gradient from .40 +/- .25 to .17 +/- .07 (P = .005); PTA from .37 +/- .14 to .11 +/- .04 (P = .001); LI after PTA from .40 +/- .16 to .12 +/- .06 (P = .001). Thus, LI is effective (less than PTA) in relieving experimental atherosclerotic stenoses and seems useful when combined with PTA.