Daniel R. Grana

Carotid rupture and intraplaque hemorrhage: Immunophenotype and role of cells involved

BACKGROUND A complete immunohistochemical characterization in complicated carotid plaques is still lacking. The cellular components of 165 carotid endarterectomy specimens were analyzed to assess their role in the pathogenesis of plaque rupture and intraplaque hemorrhage without rupture. METHODS AND RESULTS The fibrous caps at the sites of plaque rupture showed CD68+ macrophages, T-lymphocytes, and scarce B-lymphocytes. Ruptured plaques showed mononuclear infiltrates in the caps, shoulders, and bases of the plaques in 85% of the cases. Only 46% of nonruptured plaques showed such infiltrates (P <.0001). Two types of lipid cores were recognized: avascular or mildly vascularized and highly vascularized. The vessels of the latter type reacted with CD31 and CD34. In 57.5% of the cases, the base and the shoulders of the plaques showed neoformed, CD34+ vessels, often surrounded by mononuclear infiltrates. Intraplaque hemorrhage without rupture had highly vascularized lipid cores in all cases. T-lymphocytes and macrophages were in close contact with neoformed vessels. CONCLUSIONS Plaque rupture is characterized by mononuclear cell infiltration of the caps, whereas intraplaque hemorrhage without rupture is characterized by extensive vascularization of the plaque.

Chagas cardiomyopathy: Europe is not spared!

Chagas’ disease was first described in 1909 by the Brazilian physician Carlos Chagas, who named the parasite Trypanosoma cruzi after his mentor, Oswaldo Cruz.1 It causes more deaths in the Americas than any other parasitic disease.1 Due to the parasite distribution throughout Central and South America, it is commonly known as the ‘American trypanosomiasis’. As such, it is considered to be an ‘exotic’ disease in Europe, where it is virtually undiagnosed. However, thanks to free circulation of individuals and employment opportunities Europe is a magnet for millions of immigrants, many of whom are from South America. We will review the compelling arguments by which chagasic cardiomyopathy should be moved upfront in the mindset of European cardiologists, actively looked for, and appropriately recognized. Vectorial transmission of the disease is the most common form in endemic countries. This occurs through haematophagous insects (Triatominae), which become vectors for Trypanosoma cruzi by biting an infected animal or person; when infected triatominae bite, they transmit the parasite by defecating on the hosts skin.2 The insects vector of the disease is present throughout most of South and Central America, their zone of distribution encompassing southern USA.2 In non-endemic countries, the disease is transmitted through blood transfusions, organ donations, and from mother to child at birth. However, besides possible occurrence of new cases of infection, substantial concern exists regarding the progressive development of cardiomyopathy in many individuals who had already become infected in their native country, and then move to Europe. The disease has three phases. The initial infection is characterized by an acute phase, which in most cases goes asymptomatic. Infection is followed by a long ‘indeterminate phase’.2 The indeterminate form of chronic Chagas’ disease is defined as chronically infected patients with positive serology but no alterations of heart, oesophagus, and …

Chromosomal alterations in atherosclerotic plaques

Alterations of chromosomes 7 and 11 have been involved in the progression of atherosclerosis. Twenty-three carotid endarterectomy specimens were studied for the presence of alterations in chromosomes 7 and 11, and fibroblastic growth factor-3 (FGF-3) gene amplification. Besides classic histological stainings, immunophenotyping of cellular and vascular components and fluorescence in situ hybridization (FISH) were performed. At the caps, unstable plaques (n=18) showed inflammatory infiltration of macrophages, smooth muscle cells, and T-lymphocytes. Specifically in these regions, the FISH showed varying percentages of trisomy (15/18) and tetrasomy (8/15) of chromosome 7. In four cases polisomy 7 was noted in some nuclei. Monosomy of chromosome 11 and gene amplification of FGF-3 gene was observed. The FISH of the five stable plaques and normal arterial walls showed no chromosome alterations; furthermore, chromosome 3, which is not involved in atherosclerotic progression, presented a normal ploidy of smooth muscle cells in stable and unstable plaques and normal arterial walls. In conclusion, chromosome 7 and 11 alterations and FGF-3 gene amplification are components of unstable plaques, and might contribute to the evolution of stable plaques into complicated plaques.

Atherosclerotic plaque rupture and intraplaque hemorrhage do not correlate with symptoms in carotid artery stenosis.

OBJECTIVE Previously we failed to demonstrate a correlation between plaque type and symptoms in 165 carotid endarterectomy specimens. The purpose of this study was to analyze the relation between the anatomy of the carotid plaques and the presence of symptoms in 281 carotid endarterectomy specimens. METHODS The patients were 213 men (mean age, 68 years) and 68 women (mean age, 68.7 years), with symptomatic disease (n = 133) or asymptomatic disease (n = 148). Specimens were processed for histologic analysis and immunohistochemistry. RESULTS Plaques were categorized as complicated or noncomplicated, and ruptured or nonruptured. Risk factors could not be correlated with any pathologic or immunohistochemical findings or between plaque type and clinical symptoms. CONCLUSIONS Almost 70% of plaque specimens demonstrated thrombus, intraplaque hemorrhage, or both. Thrombosis was observed in one fourth of specimens, and intraplaque hemorrhage in almost two thirds of specimens. Sixty four percent of plaques demonstrated neovascularization. It was not possible to demonstrate that complicated plaques (plaque rupture, thrombosis, intraplaque hemorrhage) are associated with symptoms, and it appears that such plaques may occur at any time, irrespective of symptoms.

Expression of c-fos, p53 and PCNA in the unstable atherosclerotic carotid plaque

BACKGROUND The process by which a fibrofatty plaque evolves into a fibrotic lesion or into an unstable, lipid-rich plaque is poorly understood. In this study our aim is to deepen the knowledge of the cellular proliferation mechanisms that characterize the initial phases of destabilization of the unstable carotid plaque. METHODS 32 specimens from carotid endarterectomies were employed to assess by immunohistochemical methods, either in stable (n=10) or unstable (n=22) atherosclerotic plaques, the proliferating cell nuclear antigen (PCNA), the proto-oncogene c-fos, and the oncoprotein p53. RESULTS 18/32 atherosclerotic plaques (all unstable), showed c-fos immunopositivity (P<0.0001). Ten lesions, three stable and seven unstable, were PCNA+, while 13 cases were positive for p53 (three stable and 10 unstable plaques). When comparing symptomatic vs. asymptomatic patients, the most striking finding was the coincidence between c-fos, PCNA and p53 protein positivity observed only in unstable plaques of seven out of eight patients, all with previous episodes of stroke or transient ischemic attacks. On the other hand, none of the above mentioned positivity was detected in the 24 asymptomatic patients (P<0.0001). CONCLUSIONS These findings indicate an important role of these biomarkers in vascular biology. A series of molecular pathways of disease development and progression common both to atherosclerosis and cancer, support that the worlds two most common diseases are more closely aligned than previously believed.

Perinatal and infant early atherosclerotic coronary lesions.

OBJECTIVE Because the fetal origin of coronary artery lesions is controversial, early atherosclerotic coronary artery lesions in late fetal stillborns and infants, as well as the possible atherogenic role of maternal cigarette smoking, were studied. METHODS Twenty-two fetal death and 36 sudden infant death syndrome victims were examined by autopsy. In 28 of 58 cases, the mothers were smokers. Serially cut sections of coronary arteries were stained for light microscopy and immunotypified for CD68, CD34, alpha-smooth muscle actin, proliferating cell nuclear antigen, c-fos and apoptosis. RESULTS Multifocal coronary lesions were detected in 10 of 12 fetuses and in 15 of 16 infants whose mothers smoked. Arterial lesions in infants with nonsmoking mothers were observed in only five cases (two of 10 fetuses and three of 20 infants) (P<0.001). Alterations ranged from focal areas with mild myointimal thickening in prenatal life to early soft plaques in infants. Smooth muscle cells infiltrated into the subendothelium. These early lesions demonstrated c-fos gene activation in the smooth muscle cells of the media, and in some of these, positivity for apoptosis was observed, suggesting that c-fos overexpression may promote proliferation, as evidenced by proliferating cell nuclear antigen-positive cells. CONCLUSIONS Early intimal alterations of the coronary arteries are detectable in the prenatal and infancy period, and may be significantly associated with maternal smoking.

Characterization of myocardial hypertrophy by DNA content, PCNA expression and apoptotic index.

BACKGROUND At present little is known about the biological basis of cellular alterations in myocardial hypertrophy. The present study aims to analyze proliferating cell nuclear antigen (PCNA) expression, DNA content and apoptosis, in several types of myocardial hypertrophy in order to define the biological characteristics of this process. METHODS The biological parameters were investigated in normal hearts (n=4) and in 21 cases of left ventricular myocardial hypertrophy related to pressure overload (n=7), post-infarction remodeling (n=8) and hypertrophic cardiomyopathy (HCM) (n=8). RESULTS The analyzed biomarkers were similar in hypertension and in remodeling, with a very high apoptotic index (mean values: 8.1 and 8.5%, respectively), a low PCNA positivity (mean values: 1.8 and 1.6%) and a prevalent diploid DNA content (DNA index: 1.2). Conversely, HCM showed a high mean PCNA index (21.2%) associated with a prevalence of hyperdiploid myocytes (DNA index: 1.8) and a low number of apoptotic cells (mean value: 1.7%). CONCLUSIONS There are significant biological differences between hypertrophy in HCM and that related to arterial hypertension and post-infarction remodeling. Therefore, the combined evaluation of DNA content, PCNA and apoptotic indices could provide a powerful diagnostic tool in doubtful cases of myocardial primary or secondary hypertrophy and open new avenues in the clinical treatment of these entities.

Are Kinking and Coiling of Carotid Artery Congenital or Acquired

Dolichoarteriopathies consist of tortuosity, kinking, or coiling of the extracranial carotid arteries. Some authors consider these alterations a consequence of atherosclerotic vessel remodeling, while others ascribe them to anatomical variations of embryological origin. The objective was to establish whether carotid dolichoarteriopathies belonged to a congenital origin or to acquired conditions. Color Doppler ultrasonography of neck vessels was performed in 885 participants, whose age ranged from 1-day-old infants to 90-year-old adults. Prevalence of kinking and coiling was evaluated, and it was related to the presence of cardiovascular risk factors. Prevalence of either kinking or coil of carotid arteries showed no increase with age, as it was comparable across all ages; furthermore, frequency of these alterations showed no relationship to cardiovascular risk factors nor to the presence of atheromatous plaques. These findings suggest that carotid dolichoarteriopathies are a result of alterations in embryological development rather than vascular remodeling secondary to aging and/or atherosclerosis.

Pig Pancreatic Islet Transplantation Into Spontaneously Diabetic Dogs

INTRODUCTION Pig islet xenotransplantation represents an attractive way to solve our human organ shortage. In this preclinical protocol, we implanted adult porcine islets microencapsulated in alginate-polylysin into insulin-dependent diabetic dogs. METHODS Pancreata were obtained from animals weighing 100 to 150 kg in a slaughterhouse. The islets were isolated by collagenase digestion. The encapsulation technique was a modification of Suns method. Isolated islets (5000 islet equivalents per kilogram of dog weight) were mixed with 1.6% low-viscocity alginate. Microcapsules were cultured for 36 hours before implantation. The five dogs were in healthy prior to induction of diabetes mellitus at least 1 year prior. Under sedation, we implanted microcapsules. We performed determinations of peripheral blood insulin at baseline and every 3 months as well as glycosylated hemoglobin at baseline and every 4 months. During follow-up, glycemia was estimated twice a day at 3 hours after morning and night meals using a blood glucose monitoring system. RESULTS We observed significant decrease (20%-80%) in insulin needs (P < .01). Of note, before the procedure no hormone was detected in the blood at 6 to 12 months after transplantation, plasma insulin had improved significantly (P < .05) and glycosylated hemoglobin also showed a significant decrease (P < .01). All owners subjectively claimed that their animals were enjoying a better quality of life. DISCUSSION Our preliminary data suggested that pig islet microencapsulation achieved metabolic control in type I diabetic dogs without the risk of immunosuppression using one or two procedures per year.

Mortality and morbidity from smoking-induced cardiovascular diseases:: The necessity of the cardiologist's involvement and commitment

This review deals with tobacco-associated cardiovascular effects and diseases. The importance of tabaccoism in primary care, its effects on cardiovascular, and immunology system and hemostasia, as well as, the role of smoking in atherosclerosis, coronary heart disease, acute myocardial infarct, diabetes, and other alterations are discussed. Finally we summarize the general tobacco control policies and the methods to achieve smoking cessation. Although it is well established the causal relationship between smoking and disease, and the general public is aware of this, the cardiologists involvement and commitment is of utmost importance.