Cardiovascular involvement in systemic autoimmune diseases

Autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), primary antiphospholipid syndrome (APS), systemic sclerosis and systemic vasculitis, affect a large number of people in whom one of the leading causes of morbidity and mortality is cardiovascular disease. Cardiovascular disease is associated with the development of accelerated atherosclerosis. It seems to occur at a younger age than in the general population, is often asymptomatic and, in addition to traditional risk factors, also involves specific risk factors as chronic inflammation, the duration and activity of the autoimmune disease, and immunosuppressive therapy. The early phases of cardiovascular involvement in patients with autoimmune diseases may be clinically silent, with only a microcirculation disorder present. There are various means of detecting morphological cardiac damage: coronary angiography remains the gold standard for diagnosing coronary stenosis, but new, non invasive and more reliable methods have been introduced into clinical practice in order to detect subclinical microcirculation abnormalities.

An echocardiographic-confirmed case of atrial myxoma causing cerebral embolic ischemic stroke: a case report

A myxoma is the most common primary tumor of the heart. It has been reported as the source of a cardiogenic embolism. Therefore, it is important for clinicians to detect the myxoma early via echocardiography to prevent complications, such as syncope, sudden death, and cerebral embolic ischemic stroke. This report presents the case of a 54-year-old female whose clinical manifestation of atrial myxoma was an ischemic stroke. Atrial myxoma was later confirmed as the cause of her symptoms via transesophageal echocardiography.

Left ventricular diastolic function evaluated with tissue Doppler imaging in children with familial Mediterranean fever

The aim of this study was to assess the left ventricular diastolic function using conventional echocardiography and tissue Doppler imaging in children with familial Mediterranean fever. This study included 29 (13 males and 16 females) patients and 30 healthy subjects as controls. Body mass index was calculated and arterial blood pressure was monitored. After an overnight fast, venous blood samples were taken and serum amyloid A protein, C-reactive protein, serum-fasting glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol, very low density lipoprotein cholesterol, and serum low-density lipoprotein cholesterol levels were measured. A complete 2-dimensional, M-mode, pulse wave Doppler, and pulse wave tissue Doppler echocardiographic examination was performed. There were no significant differences between the groups regarding age, body mass index values, systolic and diastolic blood pressures, heart rates, serum-fasting glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol, very low density lipoprotein cholesterol, and serum low-density lipoprotein cholesterol. Serum levels of inflammatory markers were higher in patients' group (C-reactive protein and serum amyloid A protein levels were 10.84 mg/dl, 22.32 mg/l in patients' group, respectively, and 4.11 mg/dl, 3.65 mg/l, respectively, in the healthy controls.) Peak mitral A wave, E and A wave ratio differed significantly in both groups. There were statistically significant differences regarding parameters observed by tissue Doppler imaging such as E'm, A'm, E'm, and A'm ratio between patients' group and controls. Tissue Doppler imaging provided additional information on left ventricular diastolic function. While systolic functions were in normal range, some of the diastolic function parameters were impaired in patients with familial Mediterranean fever during childhood.

Giant left atrial myxoma mimicking severe mitral valve stenosis

We report a case of giant left atrial myxoma in a young patient with clinical manifestation as congestive heart failure attributable to severe mitral valve stenosis. An early clinical and echocardiographic diagnosis was performed and the patient had an optimal outcome with surgery treatment.

The heart and cardiovascular manifestations in rheumatoid arthritis

Cardiovascular features in rheumatoid arthritis (RA) are common. Among those are the classical extra-articular features that not only include pericarditis, cardiomyopathy/myocarditis, cardiac amyloidosis, coronary vasculitis, arrhythmia and valve diseases, but also congestive heart failure and ischaemic heart disease which are found more frequently and are associated with an increased mortality compared with the general population. This overview discusses the epidemiological aspects of these cardiovascular diseases and their relevance for diagnosis and treatment of RA.

Hypoadiponectinemia in type 2 diabetes mellitus in men is associated with sympathetic overactivity as evaluated by cardiac 123I-metaiodobenzylguanidine scintigraphy

Hypoadiponectinemia is associated with insulin resistance. However, there is very limited information about the relationship between plasma adiponectin and cardiac autonomic nervous function. We tested the hypothesis that hypoadiponectinemia is associated with cardiac sympathetic overactivity in patients with type 2 diabetes mellitus. Thirty-three male type 2 diabetic patients not on insulin treatment were classified into a hypoadiponectinemia group (plasma adiponectin concentration, <4.0 microg/mL; age, 58.6 +/- 8.6 years [mean +/- SD]; n = 14) and an age-matched normoadiponectinemia group (serum adiponectin concentration, >/=4.0 microg/mL; age, 58.2 +/- 8.1 years; n = 19). In each patient, baroreflex sensitivity, heart rate variability, plasma norepinephrine concentration, and cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphic findings were assessed. Compared with the normoadiponectinemia group, the hypoadiponectinemia group had a higher body mass index (P < .01), higher plasma concentrations of glucose and insulin (P < .05 and P < .01, respectively), higher homeostasis model assessment of insulin resistance (HOMA-IR) values (P < .005), higher plasma triglyceride levels (P < .05), and lower plasma high-density lipoprotein cholesterol levels (P < .05). In the hypoadiponectinemia group, the autonomic function measurements included a lower baroreflex sensitivity (P< .05) and a lower delayed myocardial uptake of (123)I-MIBG (P < .01) with a higher washout rate (P < .05). Multiple regression analysis revealed that the plasma adiponectin level was independently associated with HOMA-IR (F = 9.916) and the percent washout rate of (123)I-MIBG (F = 5.985). Our results suggest that in middle-aged men with type 2 diabetes mellitus, hypoadiponectinemia is associated with cardiac sympathetic overactivity as determined by (123)I-MIBG scintigraphy.

Left Ventricular Diastolic Dysfunction as Assessed by Echocardiography in Metabolic Syndrome

The purpose of the present study was to elucidate the cardiac structure and function in patients who have metabolic syndrome but no history of cardiovascular disease by analyzing echocardiographic findings. Echocardiographic examination was performed to screen for cardiovascular disease in 135 patients who were in their sixties. Patients were divided into metabolic syndrome (n=65, age: 65+/-2.7 years) and non-metabolic syndrome (n=70, age: 66+/-2.5 years) groups based on the criteria for metabolic syndrome proposed by the Japanese Society of Hypertension and seven other societies in 2005. The left ventricular (LV) wall thickness and dimension were measured by M-mode echocardiography. The relative wall thickness, LV mass index, and LV ejection fraction (LVEF) were calculated. LV diastolic function was assessed by the peak velocity of early rapid filling (E velocity) and the peak velocity of atrial filling (A velocity), and the ratio of E to A (E/A) was assessed by the transmitral flow. The Tei index, which reflects both LV diastolic and systolic function, was also calculated. There were no differences in relative wall thickness, LV mass index, or LVEF between the two groups. However, both the EIA and Tei index were significantly different between the metabolic syndrome (0.66+/-0.14 and 0.36+/-0.07, respectively) and non-metabolic syndrome (0.88+/-0.25 and 0.29+/-0.09) groups (p<0.001). These results indicate that patients with metabolic syndrome can have cardiac diastolic dysfunction even if they have neither LV hypertrophy nor systolic dysfunction.

Modeling the MHC class I pathway by combining predictions of proteasomal cleavage, TAP transport and MHC class I binding

Epitopes presented by major histocompatibility complex (MHC) class I molecules are selected by a multi-step process. Here we present the first computational prediction of this process based on in vitro experiments characterizing proteasomal cleavage, transport by the transporter associated with antigen processing (TAP) and MHC class I binding. Our novel prediction method for proteasomal cleavages outperforms existing methods when tested on in vitro cleavage data. The analysis of our predictions for a new dataset consisting of 390 endogenously processed MHC class I ligands from cells with known proteasome composition shows that the immunological advantage of switching from constitutive to immunoproteasomes is mainly to suppress the creation of peptides in the cytosol that TAP cannot transport. Furthermore, we show that proteasomes are unlikely to generate MHC class I ligands with a C-terminal lysine residue, suggesting processing of these ligands by a different protease that may be tripeptidyl-peptidase II (TPPII).

Importance of poly(ADP-ribose) polymerases in the regulation of DNA-dependent processes

Poly(ADP-ribosyl)ation of proteins is involved in the regulation of basal cellular processes and seems to be crucial for genomic integrity and cell survival. Several nuclear poly(ADP-ribose) polymerases (PARPs) are known which interact with various proteins involved in DNA metabolism. These proteins can be targets of poly(ADP-ribosyl)ation, which generally downregulates their activities. Accordingly, PARPs have been implicated in numerous processes involving chromosomal DNA, such as the regulation of chromatin structure, DNA repair, replication and transcription. PARP-1, the major cellular PARP, and PARP-2 are activated by DNA strand breaks. These enzymes have been shown to participate in DNA repair. PARP-1 has also been associated with DNA replication and recombination. Another outstanding feature of PARP-1 is its impact on the activities of transcription factors and on gene expression. Two other nuclear PARP enzymes, tankyrase-1 and tankyrase-2, are important for telomere maintenance.

Introduction to poly(ADP-ribose) metabolism

Poly(ADP-ribosyl)ation is a posttranslational modification of proteins in eukaryotic cells catalysed by a family of NAD+ ADP-ribosyl transferases, the poly(ADP-ribose) polymerases (PARPs). PARP-encoding genes now constitute a superfamily of at least 18 members encoding proteins that share homology with the catalytic domain of the founding member, PARP-1. Poly(ADP-ribose) metabolism is of central importance in a wide variety of biological processes including maintenance of genomic stability, DNA repair, transcriptional regulation, centromere function, modulation of telomere length, regulation of proteasomal protein degradation, regulation of endosomal vesicle trafficking and apoptosis. The life cycle of poly(ADP-ribose) is discussed in the following section. In addition, an overview of the genes and proteins involved in poly(ADP-ribose) metabolism and their possible cellular function is provided.

Alpha-crystallin: an ATP-independent complete molecular chaperone toward sorbitol dehydrogenase

alpha-Crystallin, the major component of the vertebrate lens, is known to interact with proteins undergoing denaturation and to protect them from aggregation phenomena. Bovine lens sorbitol dehydrogenase (SDH) was previously shown to be completely protected by alpha-crystallin from thermally induced aggregation and inactivation. Here we report that alpha-crystallin, in the presence of the SDH pyridine cofactor NAD(H), can exert a remarkable chaperone action by favoring the recovery of the enzyme activity from chemically denaturated SDH up to 77%. Indeed, even in the absence of the cofactor, alpha-crystallin present at a ratio with SDH of 20:1 (w:w) allows a recovery of 35% of the enzyme activity. The effect of ATP in enhancing alpha-crystallin-promoted SDH renaturation appears to be both nonspecific and to not involve hydrolysis phenomena, thus confirming that the chaperone action of alpha-crystallin is not dependent on ATP as energy donor.