Carlos Eli Piccinato

A second mutation in the methylenetetrahydrofolate reductase gene and the risk of venous thrombotic disease

We assessed the effect of a recently described mutation in the MTHFR gene (1298 A → C) on the risk of deep venous thrombosis (DVT) by determining its prevalence in 190 patients with verified DVT and in age‐, race‐ and gender‐matched controls. MTHFR 1298 A → C was found in 42.1% of patients and in 41.1% of controls. The OR for venous thrombosis was 1.07 (95% CI 0.70–1.65) for heterozygotes and 0.83 (95% CI 0.33–2.08) for homozygotes. The OR for the factor V Leiden (FVL) mutation was 3.40 (95% CI 1.22–9.48), for FII 20210 G → A was 5.22 (95% CI 1.12–24.2) and for MTHFR 677 C → T, 1.24 (95% CI 0.82–1.87). No significant increased risk for venous thrombosis was found when MTHFR 1298 A → C was coinherited with FVL (OR 2.85, 95% CI 0.88–9.23), FII 20210 G → A (OR 7.19, 95% CI 0.87–59.4) or MTHFR 677 C → T (OR 1.44, 95% CI 0.71–2.92). These data do not support a critical role of MTHFR 1298 A → C in the predisposition to DVT.

Peripheral glucose metabolism in human hyperprolactinaemia

OBJECTIVE Prolactin has important biological actions in several species which include metabolic control and waterlelectrolyte balance. However, human PRL has generally been characterized as a mammotrophic hormone and it is unknown whether PRL has any important metabolic actions. This study was thus conducted to evaluate the effect of hyperprolactinaemia on peripheral muscle glucose metabolism.

Ultrasonic tissue characterization of vulnerable carotid plaque: correlation between videodensitometric method and histological examination

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.

Mitochondrial Alterations in Skeletal Muscle Submitted to Total Ischemia

BACKGROUND The role of mitochondrial lesions in the pathogenesis of irreversible cellular ischemia is controversial. The inability to restore mitochondrial function is correlated with the inability to reverse cell damage in various tissues. The objective of the present study was to compare parameters associated with oxidative phosphorylation and the inner mitochondrial membrane potential of skeletal muscle of rats submitted to total ischemia in order to determine which mitochondrial alterations are mainly affected in this condition. MATERIAL AND METHODS Wistar rats were submitted to 5 h total ischemia using the tourniquet method (ischemic limb group). The contralateral limb of each rat was used as control (control limb group). After the ischemic period, muscle biopsies were obtained for the isolation of the mitochondrial fractions, which were submitted to polarographic analysis for the determination of ADP-activated oxygen consumption (state 3), basal respiration (state 4), and the ratio of the two respiratory activities: the respiratory control ratio (RCR). The potential of the inner mitochondrial membrane was determined by measuring the fluorescence difference between coupled and uncoupled mitochondria using safranine O as indicator. RESULTS After 5 h of ischemia, a significant reduction of all parameters studied was observed in skeletal muscle submitted to ischemia compared to the control limbs. CONCLUSIONS Five-hour total ischemia applied to rat skeletal muscle led to the inhibition of the mitochondrial respiratory chain (represented by decreased state 3 and state 4 respiration rates). The percentage decrease in the electrical potential of the inner membrane was similar to the percentage reductions observed for state 4 respiration and the RCR. The parameter mostly affected by ischemia was ADP-activated respiration (state 3).

Effect of NFκB Inhibition by CAPE on Skeletal Muscle Ischemia-Reperfusion Injury

BACKGROUND/AIMS Nuclear factor kappa B (NFkappaB) plays important role in the pathogenesis of skeletal muscle ischemia/reperfusion (I/R) injury. Caffeic acid phenyl ester (CAPE), a potent NFkappaB inhibitor, exhibits protective effects on I/R injury in some tissues. In this report, the effect of CAPE on skeletal muscle I/R injury in rats was studied. METHODS Wistar rats were submitted to sham operation, 120-min hindlimb ischemia, or 120-min hindlimb ischemia plus saline or CAPE treatment followed by 4-h reperfusion. Gastrocnemius muscle injury was evaluated by serum aminotransferase levels, muscle edema, tissue glutathione and malondialdehyde measurement, and scoring of histological damage. Apoptotic nuclei were determined by a terminal uridine deoxynucleotidyl transferase dUTP nick end labeling assay. Muscle neutrophil and mast cell accumulation were also assessed. Lipoperoxidation products and NFkappaB were evaluated by 4-hydroxynonenal and NFkappaB p65 immunohistochemistry, respectively. RESULTS Animals submitted to ischemia showed a marked increase in aminotransferases after reperfusion, but with lower levels in the CAPE group. Tissue glutathione levels declined gradually during ischemia to reperfusion, and were partially recovered with CAPE treatment. The histological damage score, muscle edema percentage, tissue malondialdehyde content, apoptosis index, and neutrophil and mast cell infiltration, as well as 4-hydroxynonenal and NFkappaB p65 labeling, were higher in animals submitted to I/R compared with the ischemia group. However, the CAPE treatment significantly reduced all of these alterations. CONCLUSIONS CAPE was able to protect skeletal muscle against I/R injury in rats. This effect may be associated with the inhibition of the NFkappaB signaling pathway and decrease of the tissue inflammatory response following skeletal muscle I/R.

Influence of high-heeled shoes on venous function in young women

BACKGROUND Walking with high-heeled shoes is a common cause of venous complaints such as pain, fatigue, and heavy-feeling legs. The aim of the study was to clarify the influence of high-heeled shoes on the venous return and test the hypothesis that women wearing different styles of high-heeled shoes present an impaired venous return when compared with their values when they are barefoot. METHODS Thirty asymptomatic women (mean age, 26.4 years) wearing appropriately sized shoes were evaluated by air plethysmography (APG), a test that measures changes in air volume on a cuff placed on the calf, while they performed orthostatic flexion and extension foot movements and altered standing up and lying down. The test was repeated in four situations: barefoot (0 cm), medium heels (3.5 cm), stiletto high heels (7 cm), and platform high heels (7 cm). The APG values of venous filling index (VFI), ejection fraction (EF), and residual volume fraction (RVF) were divided into four groups according to heel height and compared by repeated-measures analysis of variance. RESULTS RVF was increased in the groups wearing high heels (stiletto and platform) compared with the barefoot group (P < .05). RVF was increased in the medium-heel group (3.5 cm) compared with the barefoot group (P < .05), and despite the lack of statistical significance, the medium-heel group showed lower values of RVF compared with the two high-heel groups. The EF parameter followed the opposite tendency, showing higher values for the barefoot group compared with the other three groups (P < .05). Values for VFI were similar in the three situations evaluated. CONCLUSIONS High heels reduce muscle pump function, as demonstrated by reduced EF and increased RVF values. The continuous use of high heels tends to provoke venous hypertension in the lower limbs and may represent a causal factor of venous disease symptoms.

Factor V Arg306 Thr (factor V Cambridge) and factor V Arg306 Gly mutations in venous thrombotic disease

We investigated the prevalence of two reported mutations of the factor V gene (factor V Arg306 → Thr, or factor V Cambridge, and factor V Arg306 → Gly) in 104 relatively young patients with verified venous thrombosis and in 208 age‐, sex‐ and race‐matched controls, in order to establish whether the two mutations are associated with increased predisposition for venous thrombosis. PCR amplification followed by BstNI and MspI digestion was employed to determine the genotypes, and each mutation was confirmed by DNA sequencing. Among the controls, one individual was found to be heterozygous for the factor V Arg306 → Thr mutation and one heterozygous for the factor V Arg306 → Gly mutation; none of the patients carried either mutation. Our findings do not support factor V Cambridge and factor V Arg306 → Gly as risk factors for venous thrombosis.

Inflammatory Markers and Restenosis in Peripheral Percutaneous Angioplasty With Intravascular Stenting: Current Concepts

In this article, we review the current status of inflammation linked to percutaneous transluminal angioplasty with stent implantation, especially as it relates to restenosis and its clinical implications. Common to multiple vascular diseases, including atherosclerosis, interventional restenosis is a localized inflammatory reaction. Activated smooth muscle cells respond to local inflammation and migrate from the media into the lumen of the vessel, where they proliferate and synthesize cytokines which they respond to in an autocrine manner, sustaining the progression of the lesion. The deleterious effects of proinflammatory cytokines, particularly immunomodulatory interleukins, on vascular pathophysiology and development of these maladaptive processes have been the subject of intense study. Matrix metalloproteinases and tissue inhibitors of metalloproteinases are important in many physiologic and pathologic processes and their expression is related with the classic cardiovascular risk factors as well as with inflammation. They seem to play a central role in atherosclerosis and restenosis. The primary use of drug-eluting stents has become routine clinical practice for coronary artery disease, but the use in peripheral arteries remains to be further studied, like that demonstrated in sirolimus-coated Cordis trials. New studies to understand this complex process in peripheral arteries are warranted.

Prótese vascular derivada do látex

BACKGROUND: The development of vascular grafts has been crucial for advances and achievements in reconstructive vascular surgery over the past 5 decades. OBJECTIVES: To develop a new model of microperforated vascular graft using fabric covered with a natural latex-derived polymer taken from Hevea brasiliensis and assess its patency, thrombogenicity, biocompatibility and healing process, besides some mechanical properties (adaptability, elasticity, impermeability and possibility of suture), using expanded polytetrafluoroethylene graft as control. METHODS: Fifteen dogs were divided into three groups of five animals. The microperforated latex graft was implanted in all dogs and the expanded polytetrafluoroethylene graft was implanted in the contralateral pelvic limb. Postoperative follow-up was 4, 8 and 12 weeks. Analysis of results was performed according to clinical evaluation of pulses, complications (fluid collection, dehiscence, granuloma and infection), arteriography, macroscopic analysis and scanning electron micrography. RESULTS: Statistical tests revealed no significant differences (p > 0.05) concerning post-operative complications and graft patency. Both grafts were properly integrated to surrounding tissues, with connective tissue formed by collagen fibers. A neointimal layer covering all extension of the luminal surface was observed in the microperforated latex graft. Conversely, the endothelial development over the neointimal surface was limited to regions adjacent to the anastomoses in the expanded polytetrafluoroethylene graft. CONCLUSIONS: The microperforated latex graft showed satisfactory structural qualities (adaptability, elasticity, impermeability and possibility of suture) as a vascular substitute. It stimulated endothelial growth beyond contact regions with the artery in anastomoses and was biocompatible in the dogs arterial system, presenting adequate tissue integration.

Aterosclerose carotídea avaliada pelo eco-Doppler: associação com fatores de risco e doenças arteriais sistêmicas

Background: A high prevalence of carotid atherosclerosis in the population and its frequent association with several risk factors contribute to high morbidity and mortality rates. Objective: To investigate frequency and association of extracranial carotid atherosclerosis with age, sex, hypertension, ischemic coronary disease, smoking, type 2 diabetes mellitus, obesity, peripheral arterial disease, stroke, carotid occlusion, intima-media thickness and kinking. Methods: The carotid and bilateral extracranial arteries of 367 individuals (132 males and 235 females), with a mean of 63 years of age (35-91 years) were evaluated via anamnesis, clinical semiology and ultrasonography. The possible association between carotid atherosclerosis, represented by unspecific atheromatous plaques with stenosis > 10% or discrete and diffuse atheromatosis with stenosis < 10% and the risk factors listed above was statistically analyzed by the odds ratio with a confidence interval of 95%. Results: The frequency of carotid atherosclerosis and intima-media thickness was, respectively, 52 and 30.2%. There was an association between atherosclerosis types and age (≥ 64 years), stroke, obesity and smoking. When only carotid stenosis ≥ 60% was considered, there was an association with age (≥ 64 years), carotid occlusion and coronary disease. Intima-media thickness was associated with age (≥ 64 years), kinking, carotid occlusion, hypertension and ankle-brachial index < 0.9. Conclusion: Carotid atherosclerosis is highly prevalent in the population (52%) and is associated with age, obesity, stroke, coronary disease, and smoking.