Human antimicrobial peptide LL-37 is present in atherosclerotic plaques and induces death of vascular smooth muscle cells: a laboratory study.

BACKGROUND: Death of smooth muscle cells in the atherosclerotic plaques makes the plaques more prone to rupture, which can initiate an acute ischemic event. The development of atherosclerosis includes the migration of immune cells e.g. monocytes/macrophages and T lymphocytes into the lesions. Immune cells can release antimicrobial peptides. One of these, human cathelicidin antimicrobial peptide hCAP-18, is cleaved by proteinase 3 generating a 4.5 kDa C-terminal fragment named LL-37, which has been shown to be cytotoxic. The aim of the study was to explore a potential role of LL-37 in the pathophysiology of atherosclerosis. METHODS: We investigated the presence of LL-37 in human atherosclerotic lesions obtained at autopsy using immunohistochemistry. The direct effects of LL-37 on cultured vascular smooth muscle cells and isolated neutrophil granulocytes were investigated with morphological, biochemical and flow cytometry analysis. RESULTS: The neointima of atherosclerotic plaques was found to contain LL-37-like immunoreactivity, mainly in macrophages. In cultured smooth muscle cells, LL-37 at 30 mug/ml caused cell shrinkage, membrane blebbing, nuclear condensation, DNA fragmentation and an increase in caspase-3 activity as studied by microscopy, ELISA and enzyme activity assay, respectively. Flow cytometry demonstrated that LL-37 in a subset of the cells caused a small but rapidly developing increase in membrane permeability to propidium iodide, followed by a gradual development of FITC-annexin V binding. Another cell population stained heavily with both propidium iodide and FITC-annexin V. Neutrophil granulocytes were resistant to these effects of LL-37. CONCLUSION: This study shows that LL-37 is present in atherosclerotic lesions and that it induces death of vascular smooth muscle cells. In a subset of cells, the changes indicate the development of apoptosis triggered by an initial mild perturbation of plasma membrane integrity. The findings suggest a role for LL-37 as a mediator of immune cell-induced death of vascular smooth muscle cells in atherosclerosis.

Fatal colonic ischemia: A population-based study.

OBJECTIVES: To estimate the incidence of fatal colonic ischaemia (CI) and the cause-specific mortality of CI, and to describe the localization and extension of colonic infarction and quantify the risk factors associated with CI. MATERIAL AND METHODS: Between 1970 and 1982 the autopsy rate in Malmö, Sweden, was 87%, creating the possibilities for a population-based study. Out of 23,446 clinical autopsies, 997 cases were coded for intestinal ischaemia in a database. In addition, 7569 forensic autopsy protocols were analysed. In a case-control study nested in the clinical autopsy cohort, four CI-free controls, matched for gender, age at death and year of death, were identified for each fatal CI case in order to evaluate the risk factors. RESULTS: The cause-specific mortality ratio was 1.7/1000 autopsies. The overall incidence of autopsy-verified fatal CI was 1.7/100,000 person years, increasing with age up to 23/100,000 person years in octogenarians. Fatal cardiac failure (odds ratio (OR) 5.2), fatal valvular disease (OR 4.3), previous stroke (OR 2.5) and recent surgery (OR 3.4) were risk factors for fatal CI. Narrowing/occlusion of the inferior mesenteric artery (IMA) at the aortic origin was present in 68% of the patients. The most common segments affected by transmural infarctions were the sigmoid (83%) and the descending (77%) colon. CONCLUSIONS: Heart failure, atherosclerotic occlusion/stenoses of the IMA and recent surgery were the main risk factors causing colonic hypoperfusion and infarction. Segments of transmural infarctions were observed within the left colon in 94% of the patients. Awareness of the diagnosis and its associated cardiac comorbidities might help to improve survival.

Portal vein thrombosis: prevalence, patient characteristics and lifetime risk: a population study based on 23,796 consecutive autopsies.

AIM: To assess the lifetime cumulative incidence of portal venous thrombosis (PVT) in the general population. METHODS: Between 1970 and 1982, 23,796 autopsies, representing 84% of all in-hospital deaths in the Malmö city population, were performed, using a standardised protocol including examination of the portal vein. PVT patients were characterised and the PVT prevalence at autopsy, an expression of life-time cumulative incidence, assessed in high-risk disease categories and expressed in terms of odds ratios and 95% CI. RESULTS: The population prevalence of PVT was 1.0%. Of the 254 patients with PVT 28% had cirrhosis, 23% primary and 44% secondary hepatobiliary malignancy, 10% major abdominal infectious or inflammatory disease and 3% had a myeloproliferative disorder. Patients with both cirrhosis and hepatic carcinoma had the highest PVT risk, OR 17.1 (95% CI 11.1-26.4). In 14% no cause was found; only a minority of them had developed portal-hypertension-related complications. CONCLUSION: In this population-based study, PVT was found to be more common than indicated by previous clinical series. The markedly excess risk in cirrhosis and hepatic carcinoma should warrant an increased awareness in these patients for whom prospective studies of directed intervention might be considered.

Trousseau's syndrome - what is the evidence? A population-based autopsy study.

Despite numerous studies documenting the association between cancer and venous thromboembolism (VTE), the reason for the excessive risk in certain cancers remains obscure. No large-scale studies have yet investigated the independent effects of cancer type, site and growth pattern. Between 1970 and 1982, 23,796 standardised autopsies were performed, representing 84% of all in-hospital deaths in an urban Swedish population. The relationship between cancer and PE was evaluated with logistic regression. The overall PE prevalence was 23%, and 10% of the population had a fatal PE. Forty-two per cent of pancreatic cancer patients had PE (OR 2.55; 95% CI 2.10-3.09) (p<0.001); gall bladder, gastric, colorectal and pulmonary adenocarcinomas were similarly independently associated with PE. In comparison with squamous cell lung cancer, patients with pulmonary adenocarcinoma had 1.65 times higher odds for PE (95% CI 1.20-2.29). Adenocarcinoma and metastatic cancer were independently associated with PE risk (OR 1.27; 95% CI 1.16-1.40; p<0.001, and OR 1.10;95% CI 1.01-1.20; p=0.024, respectively) but when controlling for cancer type and spread, pancreatic cancer was still associated with an OR of 2.10 (95% CI 1.71-2.58) of PE (p<0.001). We conclude that the risk of PE in cancer patients depends not only on the cancer site and spread but also on the histological type. The excess independent risk in pancreatic cancer is intriguing and should warrant further research.

Dietary supplementation of carbonate promotes spontaneous tumorigenesis in a rat gastric stump model.

OBJECTIVE: Food supplements are known to affect the development of gastric adenocarcinoma. In this study, an animal model of gastric resection was used to investigate the effects of calcium carbonate on spontaneous development of gastric adenocarcinoma. MATERIAL AND METHODS: Ninety-two Wistar rats with gastric resections (performed to induce spontaneous gastric cancer) and 60 without resections (controls) were used to analyse the carcinogenic potential of different ion supplements in food. RESULTS: Among the resected rats, cancer developed in 3 out of 18 (17%, NS) given NaCl but in 11 out of 18 (61%, p<0.01) exposed to calcium carbonate. No tumours were found in the unresected (unoperated) animals. These findings were further analysed by separately investigating the effects of calcium and carbonate ions on tumorigenesis in the gastric stump model. Cancer developed in one of 26 (4%) resected animals given a diet supplemented with CaHPO(4), which was lower than the rate observed in the resected control group fed a normal diet, although this difference was not statistically significant. However, tumour development increased significantly in the resected animals given a diet supplemented with NaHCO(3) (tumours in 13 out of 24 rats, 54%; p<0.01). CONCLUSIONS: The present results reveal a significant role for carbonate in the induction of gastric carcinoma in the rat. The relevance of this finding is underlined by the fact that carbonate is a major constituent of intestinal reflux into the stomach, and that such reflux is considered to be one of the major causes of gastric cancer.

Mesenteric venous thrombosis with transmural intestinal infarction: a population-based study.

OBJECTIVE: To determine the cause-specific mortality from and incidence of transmural intestinal infarction caused by mesenteric venous thrombosis (MVT) in a population-based study and to evaluate the findings at autopsy by evaluating autopsies and surgical procedures. METHODS: All clinical (n = 23,446) and forensic (n = 7569) autopsies performed in the city of Malmö between 1970 and 1982 (population 264,000 to 230,000) were evaluated. The autopsy rate was 87%. The surgical procedures were performed in 1970, 1976, and 1982. Autopsy protocols coded for intestinal ischemia or mesenteric vessel occlusion, or both, were identified in a database. In all, 997 of 23,446 clinical and 9 of 7,569 forensic autopsy protocols were analyzed. A 3-year sample of the surgical procedures, comprising 21.3% (11,985 of 56,251) of all operations performed during the entire study period, was chosen to capture trends of diagnostic and surgical activity. In a nested case-control study within the clinical autopsy cohort, four MVT-free controls, matched for gender, age at death, and year of death were identified for each fatal MVT case to evaluate the clinical autopsy findings. RESULTS: Four forensic and 23 clinical autopsies demonstrated MVT with intestinal infarction. Seven patients were operated on, of whom six survived. The cause-specific mortality ratio was 0.9:1000 autopsies. The incidence was 1.8/100,000 person years. At autopsy, portal vein thrombosis and systemic venous thromboembolism occurred in 2 of 3 and 1 of 2 of the cases, respectively. Obesity was an independent risk factor for fatal MVT (P =.021). CONCLUSIONS: The estimated incidence of MVT with transmural intestinal infarction was 1.8/100,000 person years. Portal vein thrombosis, systemic venous thromboembolism and obesity were associated with fatal MVT.

Prevalence and risk of pulmonary embolism in patients with intracardiac thrombosis: a population-based study of 23 796 consecutive autopsies.

AIMS: While right intracardiac thrombosis (IT) is a potential cause of pulmonary embolism (PE) similar to that of stroke in left-sided IT, its prevalence and prognostic significance has not been studied in the general population. The aim of this study was to assess the age- and gender-specific prevalence of IT and its relation to PE in a population-based autopsy cohort. METHODS AND RESULTS: Between 1970 and 1982, 23 796 autopsies, representing 84% of all in-hospital deaths in the Malmö city population, were performed, using a standardized procedure. The relationship between IT and PE was evaluated by cohort analyses and nested case-control studies. IT was present in 1706 (7.2%) patients, 727 and 747 of whom had right and left atrial IT, respectively. PE prevalence in patients with isolated left IT, isolated right IT, and combined IT was 28.5, 35.6, and 48.9%, with RR (95% CI) of 1.5 (1.3-1.8), 2.0 (1.6-2.5), and 3.5 (2.7-4.7), respectively, compared with age- and gender-matched controls. Patients dying from ischaemic heart disease had a 3.2 (2.7-3.6) times higher risk of right IT, which was associated with 43% PE prevalence. Of all patients with PE at autopsy, right IT was found in 354 (6.5%), and the only detected source of PE in 220 (4.0%). CONCLUSION: Right cardiac thrombosis, though difficult to assess clinically, is as common as left cardiac thrombosis and is associated with an increased risk of PE. The diagnosis should be considered in all cases of PE, especially in patients with atrial fibrillation or myocardial infarction and in the absence of confirmed deep vein thrombosis.

Clinical implications for the management of acute thromboembolic occlusion of the superior mesenteric artery: autopsy findings in 213 patients.

OBJECTIVE: To study findings at autopsy in patients with fatal acute thromboembolic occlusion of the superior mesenteric artery (SMA). SUMMARY BACKGROUND DATA: Acute occlusion of the SMA is difficult to diagnose and mortality remains high. In Malmo, Sweden, the autopsy rate between 1970 and 1982 was 87%, creating possibilities for a population-based study. METHODS: Among 23,496 clinical autopsies and 7569 forensic autopsies, 213 cases with acute thromboembolic occlusion of the SMA and intestinal infarction were identified. RESULTS: A clinical suspicion of intestinal infarction was documented in 32% of the patients, only 35% being in the care of surgeons. The embolus/thrombus ratio was 1.4 to 1. Thrombotic occlusions were located more proximally than embolic occlusions (P < 0.001), intestinal infarction was more extensive (P = 0.025) and thrombotic occlusions were associated with old brain infarction (P = 0.048), aortic wall thrombosis (P = 0.080), and disseminated cancer (P = 0.079). Patients with embolic occlusions (n = 122) had a higher frequency of acute myocardial infarction (AMI) than patients with thrombotic occlusions (P = 0.049). The embolic source was identified in 80%. In 115 (94%), synchronous embolism and/or source of embolus were present. There were findings of remaining cardiac thrombi in 58 (48%) and synchronous emboli affected 273 other arterial segments in 83 (68%). CONCLUSIONS: Early recognition and revascularization would have been a prerequisite for survival in at least half of the patients, since the jejunum, ileum, and colon were affected by infarction. A minority of all patients were under surgical care. AMI, cardiac thrombi, and synchronous emboli were common findings among patients with embolic occlusions.

Monitoring of atherosclerosis.

Population-based epidemiological studies of atherosclerosis using autopsy material is now impossible to perform in most countries due to declining autopsy rates. Based on epidemiological studies of atherosclerosis using autopsy material in five European cities which were carried out with an interval of 25 years in the 1960s and 1980s, respectively, we have shown that atherosclerosis in young so-called practically healthy people, 20-39 years of age, who died from accidental causes, closely reflects the level of atherosclerosis in the population as a whole. These people can thus be used for monitoring the development of atherosclerosis in a population since they are normally a subject to a medico-legal autopsy; therefore, material for such studies can be obtained. Furthermore, histomorphological studies of specimens that are taken from practically healthy people at standard places of coronary arteries and aortas also reflect this general level of atherosclerosis. These studies also provide information on the atherosclerotic process and its relation to various risk factors.

Detection of circulating and endothelial cell polymers of Z and wild type alpha 1-antitrypsin by a monoclonal antibody.

Globular inclusions of abnormal alpha1-antitrypsin (AAT) in the endoplasmic reticulum of hepatocytes are a characteristic feature of AAT deficiency of the PiZZ phenotype. Monoclonal antibodies, which contain constant specificity and affinity, are often used for the identification of Z-mutation carriers. A mouse monoclonal antibody (ATZ11) raised against PiZZ hepatocytic AAT was successfully used in enzyme-linked immunosorbent assays (ELISA) and in identification of Z-related AAT globular inclusions by immunohistochemical techniques. Using electrophoresis, Western blotting, and ELISA procedures, we have shown in the present study that this monoclonal antibody specifically detects a conformation-dependent neoepitope on both polymerized and elastase-complexed molecular forms of AAT. The antibody has no apparent affinity for native, latent, or cleaved forms of AAT. The antibody ATZ11 illustrates the structural resemblance between the polymerized form of AAT and its complex with elastase and provides evidence that Z-homozygotes beyond the native form may have at least one more circulating molecular form of AAT, i.e. its polymerized form. In addition, staining of endothelial cells with ATZ11 antibody in both M- and Z-AAT individuals shows that AAT attached to endothelial cells is in a polymerized form. The antibody can be a powerful tool for the study of the molecular profile of AAT, not only in Z-deficiency cases but also in other (patho)physiological conditions.

Efecto del tabaquismo en la aterosclerosis coronaria y de la aorta en niños y jóvenes utilizando el sistema aterométrico (1986-96). Investigación multinacional de la Organización Mundial de la Salud / Effects of smoking on atherosclerosis or the aorta and the coronary arteries in children and youth utilizing the Atherometric system

El objetivo del presente trabajo es estudiar el impacto del tabaquismo como factor de riesgo aterogénico en pacientes fallecidos y autopsiados de edades comprendidas entre 5 y 34 años. Esta investigación multinacional de la Organización Mundial de la Salud y la Federación Internacional de Sociedades de Cardiología se desarrolló durante 10 años del 1986-96. Del Centro de Coordinación general de esta investigación de Malmö, se recibieron en el Centro de Investigaciones y Referencias de Aterosclerosis de la Habana (CIRAH) un total de 966 mitad izquierda de la aorta torácica, 947 mitad izquierda de la aorta abdominal y 959 arterias coronaria derecha. Las arterias procedieron de 11 países localizados en cinco regiones de la OMS, America, Africa, Europa, Sudeste Asiatico, y Sudoeste Asiatico. Las arterias se procesaron utilizando la metodología propuesta por la OMS desde 1957 para la aplicación del Sistema Aterométrico (SA), conjunto de métodos y procedimientos considerados idóneos para la carecterización patomorfológica y morfométrica de la lesión aterosclerótica. La población de autopsias se dividió en dos grupos, fumadores y no fumadores. Los datos se procesaron utilizando análisis estadísticos descriptivos, comparativos y multivariado. Entre las conclusiones más importantes se mencionan las siguientes: La distribución de estrías adiposas y placas fibrosas en las tres arterias estudiadas, aorta torácica (AT) aorta abdominal (AA) y coronaria derecha (CD) fue mayor en los fumadores que en los no fumadores. La transformación de estrías adiposas en placas fibrosas comenzó más temprano y con mucho mayor intensidad en los fumadores. El estadístico MANOVA entre fumadores y no fumadores mostró gran significación estadística en las tres arterias. El resultado de estadístico ANOVA mostró significación estadística de las estrías adiposas en la AT y de estas las placas fibrosas en la aorta abdominal y de las placas fibrosas en la coronaria derecha. En esta investigación quedó claramente demostrado que el tabaquismo es un fuerte factor de riesgo de aterosclerosis y por lo tanto de sus consecuencias orgánicas las enfermedades Cardiovasculares en edades tempranas

Aterosclerosis en la juventud: I. Patomorfología y Morfometría según edad y sexo, utilizando el Sistema Aterométrico

Se analizaron 966 aortas torácicas, 947 aortas abdominales y 958 arterias coronarias derechas de autopsias de niños y jóvenes de edades comprendidas entre 5 y 34 años, procedentes de 18 países de 5 continentes, como parte de una investigación multinacional organizada por la Organización Mundial de la Salud y la Federación Internacional de Sociedades de Cardiología desde 1986 a 1996. Para el estudio patomorfológico y morfométrico de las arterias se utilizó el sistema aterométrico, metodología considerada idónea para la caracterización de la lesión aterosclerótica en cualquier arteria, sector vascular o grupo de pacientes. Este sistema permitió mediante el análisis cualitativo, identificar las lesiones ateroscleróticas y mediante el cuantitativo, medir las áreas ocupadas por cada una de ellas y estimar o ponderar sus valores de obstrucción y estenosis intrarterial. Se analizaron los fallecidos según su edad y sexo. Se dividieron en 3 grupos de edades: de 5 a 14, de 15 a 24 y de 25 a 34 años. Los resultados más relevantes fueron: a) la confirmación de que la aterosclerosis progresa siempre con la edad en los 2 sexos; b) que las estrías adiposas están presentes desde la más temprana edad independientemente del país de procedencia, clima, tipo de alimentación, hábitos y estilos de vida; c) que el progreso más acelerado de las estrías adiposas se encontró entre las edades de 15 a 24 años; d) que las placas fibrosas comienzan a presentarse lentamente a partir de la segunda década de la vida y progresan notablemente a partir de la tercera; e) que las placas graves son excepcionales antes de los 30 años de edad y a partir de este momento progresan lentamente.

966 thoracic aortas, 947 abdominal aortas and 958 right coronary arteries were analyzed in autopsied children and young people aged 5 to 34 years from 18 countries in 5 continents, as part of a multinational research study from 1986 to 1996 organized by the World Health Organization and the International Societies Federation of Cardiology. The atherometric system, which is considered to be an ideal methodology to characterize the atherosclerotic lesion in any artery, vascular area or group of patients, was used for the pathomorphological and morphometric study of the arteries. This system allowed to detect the atherosclerotic lesions by a qualitative analysis and to measure the areas occupied by them and estimate/weigh their obstruction and intraarterial stenosis indices by the quantitative analysis. The deceased were examined by age and sex and divided into 3 age groups: 5 to 14, 15 to 24 and 25 to 34 years. The most relevant results which were confirmed by this study were: a) the atherosclerosis increases with rising age level in males and females alike.b) fatty steaks begin with the earliest age regardless of the country of origin, climate, type of food, habits and ways of life.c) the fastest progression in fatty streaks was found in people aged 15 to 24 years. d) fibrous plaques slowly occur during the second decade of life and remarkably progreses in the third decade of life. e) the severe plaques exceptionally occur before the 30 years-old age and from that moment on, the slowly develop.