We analyzed whether normal human hepatocytes, which normally do not display Class II major histocompatibility complex antigens, can be induced to express them in vitro, and whether this induction has an in vivo counterpart in chronic liver diseases. While both alpha- and gamma-interferon induced expression of Class I antigens, only gamma-interferon induced expression of Class II antigens on hepatocytes in vitro. Recombinant interleukin 2 had no effect on major histocompatibility complex antigen expression. Both Class I and Class II antigens could be detected by indirect immunofluorescence on hepatocytes from patients with various forms of chronic liver disease, regardless of etiology. These findings suggest that gamma-interferon produced by T lymphocytes that infiltrate the liver during the course of chronic hepatitis induces Class II major histocompatibility complex antigen expression and may endow the hepatocytes with the capacity to perform accessory (antigen-presenting) cell functions.

Antibodies, Monoclonal↗

PubMedDate not supplied

Natural history of cardiac involvement in myotonic dystrophy (Steinert's disease): a 13-year follow-up study.

Myotonic dystrophy (MD) is associated with a wide spectrum of cardiac abnormalities, but only a few longitudinal studies have investigated the natural course of heart disease in MD. To assess whether neuromuscular involvement significantly predicts cardiac disorders in MD, 83 patients with various grades of disease severity were enrolled in a 13-year follow-up study (mean, 60.6 +/- 37.8 months) that included periodic physical and instrumental cardiac examinations (standard and Holter electrocardiography, echocardiography). During follow-up, muscular disease worsened clinically in 9 patients (11%) whose baseline severity grade changed accordingly; only 3 of them demonstrated parallel worsening of cardiac disturbance, however, compared with a large number of patients who showed additional cardiac abnormalities. These included further worsening of pre-existing pathologic features (19/83) and the appearance de novo of serious arrhythmias and/or conduction defects (23/83). Pacemaker implantation was necessary in 11 of 83 patients (13.2%) who had symptomatic bradyarrhythmias, bifascicular block, and P-R prolongation with a His-to-ventricle interval exceeding 55 ms, as documented by electrophysiologic study. Eight (9.6%) patients died: 2 from noncardiac and 1 from unknown causes, 1 from heart failure, and 4 from sudden death closely related to documented ventricular tachycardia. The incidence and seriousness of arrhythmic and conduction disturbances correlated with the severity of the muscular involvement. Nevertheless, cardiac and muscular disease did not show a linear progression. Cardiac involvement generally worsened more rapidly than did skeletal muscle disease.

Adolescent↗

PubMedDate not supplied

Adrenomedullin assay and its clinical significance.

Adrenomedullin (Am) is a recently discovered peptide, first purified from pheochromocytoma specimens, with a chemical structure similar to that of CGRP and amylin. Adrenomedullin is present in numerous human body tissues and its powerful vasodilatatory activity is thought to play an essential role in cardiovascular and renal homeostasis.

Adrenomedullin↗

PubMedDate not supplied

CGRP and ET-1 plasma levels in normal subjects.

OBJECTIVE: Calcitonin gene-related peptide (CGRP) is a 37 amino acid peptide displaying about 50% homology with amylin which is secreted from the pancreatic islets of Langerhans. The main form, the beta-CGRP, is produced by the enteric nervous system and perivascular nerves of the vasa-vasorum. It represents one of the most powerful vasodilator yet discovered but its role is not yet completely clarified. High levels of this peptide have been shown in patients affected with thyroid medullary carcinoma, phaemocromocytoma and lung carcinoma. Recently circulating levels of CGRP have been found in normal subjects. Endothelin-1 (ET-1), a potent vasoconstrictor peptide, isolated from porcine endothelial cells, is an important regulator of the vascular tone acting in physiological antagonism with atrial natriuretic hormone (ANH). With this study we intended to investigate the presence of any correlation between CGRP and ET-1 in normal subjects. PATIENTS: For the study we considered 20 normal subjects (11 males and 9 females) aged 23 to 50. MEASURES: Plasma levels of CGRP and ET-1 were measured by radioimmunological Kit. RESULTS: A positive and significant correlation between calcitonin gene-related peptide and endothelin-1 was found. CONCLUSIONS: Our results confirms that CGRP and ET-1 have opposing actions on vessels and that they can act together in haemodinamic regulation.

Adult↗

PubMedDate not supplied

[Morphological aspects of atherosclerosis lesion: past and present].

Atherosclerosis is an inflammatory process disease that involves the artery wall and that is characterized by the progressive accumulation of lipids. The term arteriosclerosis has been created by Lobstein in 1833. Subsequently, during the 19th century, the contribution of Rokitansky and Virchow was important to elucidate the pathogenesis of arteriosclerosis and the morphologic aspects of the plaque. In the beginning of the 20th century, Aschoff was a leading proponent who regarded the morphologically different intimal lipid deposits of children and adults as early and late stages of one disease and he called them atherosis and atherosclerosis, respectively. The first classification of atherosclerosis was made by the World Health Organization (WHO) in 1958 and it consisted of the following sequence: fatty streak, atheroma, fibrous plaque and complicated lesions. In 1990s, thanks to much more sensitive techniques, the American Heart Association (AHA) proposed a new morphological classification based on eight lesion types designated by Roman numerals which indicate the usual sequence of lesion progression. Finally, Virmani et al. (2000) described a classification with the add of a specific plaque type, not recognized by the AHA classification, called "thin fibrous cap atheroma" which is more likely to rupture. The atherosclerotic process is characterized by typical ultrastructural changes that mainly involve the endothelial and smooth muscle cells. The morphological alterations of the endothelium are associated with dysfunctions leading to a proinflammatory and prothrombotic phenotype. This process seems to be due to turbulent blood flow and low fluid shear stress that normally occurs in particular regions of the vascular tree. Inflammation has a key role in the pathogenesis of atherosclerosis and it is supported by numerous factors such as modified LDL, hypertension, diabetes mellitus, free radicals and, in particular, by infectious agents such as Chlamydia pneumoniae.

Adult↗