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BackgroundTo establish the correlation between quantitative analysis based on B-mode ultrasound images of vulnerable carotid plaque and histological examination of the surgically removed plaque, on the basis of a videodensitometric digital texture characterization.MethodsTwenty-five patients (18 males, mean age 67 ± 6.9 years) admitted for carotid endarterectomy for extracranial high-grade internal carotid artery stenosis (≥ 70% luminal narrowing) underwent to quantitative ultrasonic tissue characterization of carotid plaque before surgery. A computer software (Carotid Plaque Analysis Software) was developed to perform the videodensitometric analysis. The patients were divided into 2 groups according to symptomatology (group I, 15 symptomatic patients; and group II, 10 patients asymptomatic). Tissue specimens were analysed for lipid, fibromuscular tissue and calcium.ResultsThe first order statistic parameter mean gray level was able to distinguish the groups I and II (p = 0.04). The second order parameter energy also was able to distinguish the groups (p = 0,02). A histological correlation showed a tendency of mean gray level to have progressively greater values from specimens with < 50% to >75% of fibrosis.ConclusionVideodensitometric computer analysis of scan images may be used to identify vulnerable and potentially unstable lipid-rich carotid plaques, which are less echogenic in density than stable or asymptomatic, more densely fibrotic plaques.

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This experimental investigation was carried out to study the endothelium-dependent ischemia-reperfusion injury upon the release of nitric oxide (NO) in the canine femoral artery. The tested experimental model was the inferior canine hindlimb ischemia induced by infrarenal abdominal aortic clamping followed by reperfusion. The research protocol was standardized in four experimental groups (n=6): (1) Control group; (2) Ischemia (120 minutes) group; (3) Ischemia (90 minutes) and reperfusion (60 minutes) group; and (4) Ischemia (120 minutes) and reperfusion (90 minutes) group. The femoral artery vascular reactivity was studied in vitro with the aid of an eight "organ chambers'' setup, where segments from 4 to 5 mm, with and without endothelium, were suspended and connected to force transducers. The fundamental data of this study were as follows: (1) Ischemia caused by 120 minutes of infrarenal aortic clamping did not cause femoral artery endothelium dysfunction. (2) Ischemia caused by 90 minutes of clamping followed by 60 minutes of reperfusion also did not cause endothelium dysfunction, with an observed tendency to signal transduction impairment (studied by the sodium fluoride dose response curves). (3) Ischemia caused by 120 minutes of clamping followed by 90 minutes of reperfusion caused endothelium dysfunction, observed by the femoral artery impaired capacity of the endothelium-dependent NO release evoked by acetylcholine, adenosine diphosphate, and sodium fluoride. The present pharmacologic in vitro observations are concordant with the evidence that the NO-release impairment, caused by inferior canine hindlimb ischemia followed by reperfusion, is a consequence of endothelium cell membrane receptors, and G-proteins signal transduction dysfunction.

We report on 2 patients with AIDS aged 23 and 31 years with pseudoaneurysms of the abdominal aorta and common iliac arteries. After clinical and radiological evaluation by arteriography and computed tomography, the patients were submitted to aneurysmectomy, with the placement of a patch of dacron in the first case and the interposition of a right aorto-iliac and left femoral prosthesis in the second. The second patient developed new aneurysms of the right subclavian and left popliteal arteries 2 months after surgery. Proximal ligation of the right subclavian artery was performed to treat the first aneurysm and resection and interposition of a reversed saphenous vein was carried out to treat the pseudoaneurysm of the popliteal artery. Histopathological examination of the popliteal artery revealed necrotizing arteritis.

RESUMO: Procedimentos, como o transplante de medula óssea, a quimioterapia, a nutrição parenteral total e a hemodiálise, exigem a necessidade cada vez maior do acesso venoso central de longa duração (AVCLD). Utilizam-se, de acordo com a indicação, cateteres totalmente implantáveis (com reservatório) e parcialmente implantáveis (Broviac-Hickman). Foram avaliados setenta e nove (79) cateteres implantados, consecutivamente, em sessenta e seis (66) pacientes, tratados no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da USP, no período de janeiro de 1993 a junho de 1997. Avaliaram-se os seguintes parâmetros: indicação do acesso venoso, tipo de cateter implantado, técnica utilizada, complicações precoces e tardias e duração do implante. Dos sessenta e seis (66) pacientes, trinta e quatro (34) (51,5%) eram homens. A idade média foi de 28,2 anos. Houve predomínio de indicação de implante de cateter para realizar-se a quimioterapia em cinquenta e cinco (55) (69,5%) pacientes e transplante de medula óssea em doze (12) (15,2%). Foram implantados vinte e oito (28) (35,5%) cateteres com reservatório e cinqüenta e um (51) (64,5%) parcialmente implantáveis. Quanto à técnica utilizada, 71,4% foram implantados por punção percutânea e os demais por dissecção e cateterização venosa, a céu aberto. Ocorreram duas complicações relacionadas à técnica, nove (9) infecções e oito (8) oclusões tardias. A duração média da implantação dos cateteres foi trezentos e setenta e um (371) dias para os cateteres Broviac-Hickman e trezentos e noventa e cinco (395) para o totalmente implantável. Não houve óbito associado aos implantes. Os índices de complicações precoces e tardias, observadas nesta casuística, assemelham-se aos dados encontrados na literatura.

The great resistance of muscle to ischemia was used to study blood flow-dependent phenomena produced by anesthetic drugs in this condition. A short reperfusion period was used in order to favor metabolic changes indicative of an effect of chlorpromazine (CPZ) on blood flow. Gracilis muscles of dogs were submitted to 5 h of ischemia and 30 min of reperfusion. CPZ-treated animals were injected I.V. (2 mg/kg) 10 min before the beginning of ischemia. Biopsies provided the material for tissue measurements. Lactate content and pH were determined in blood samples collected from a muscle efferent vein. In both the CPZ-treated and nontreated groups, ischemia induced a decline in muscle glycogen content, with a corresponding increase in muscle lactate and a decrease in mitochondrial respiratory control ratio. After 30 min of reperfusion, tissue levels of lactate did not attain preischemic values but showed a clear decline in the two experimental groups, evidencing the reversible state of the muscle. All other metabolic parameters remained unchanged. Mitochondrial respiratory control remained functional during ischemia and reperfusion. Blood pH displayed similar changes in both groups. There was no metabolic indication that the drug affected blood flow during early reperfusion and/or of a greater sensitivity of muscle endothelial cells to anesthetic drugs.