Arterial media calcification in end-stage renal disease: impact on all-cause and cardiovascular mortality.

BACKGROUND: Cross-sectional and follow-up studies on end-stage renal disease patients showed that arterial calcifications are associated with cardiovascular (CV) morbidity and are an independent predictor of all-cause and CV mortality. However, these studies did not examine the impact on prognosis according to the type of calcification, i.e. intimal vs medial. Arterial media calcification (AMC), a non-occlusive condition, affects haemodynamics differently from arterial intima calcification (AIC), which occurs in atherosclerotic plaques. The aim of this study was to investigate the prognostic value of AMC in relationship to all-cause or CV mortality for stable haemodialysis (HD) patients. METHODS: We included 202 such patients in the present study. At baseline, soft-tissue native radiograms of the pelvis and the thigh were analysed for the presence and type (AMC vs AIC) of arterial calcifications. All patients underwent B-mode ultrasonography of the common carotid artery to determine the presence of atherosclerotic calcified plaques, measurement of aortic pulse wave velocity and echocardiography. RESULTS: AIC was usually observed in older patients with a clinical history of atherosclerosis before starting HD treatment and typical risk factors associated with atherosclerotic disease. AMC was observed in young and middle-aged patients without conventional atherosclerotic risk factors. AMC was closely associated with the duration of HD and calcium-phosphate disorders, including the oral dose of elemental calcium prescribed as phosphate binder (CaCO(3)). Compared to patients with AIC, patients with AMC had a longer survival, but in turn their survival was significantly shorter than that of patients without calcifications. CONCLUSIONS: AMC is a strong prognostic marker of all-cause and CV mortality in HD patients, independently of classical atherogenic factors. The principal effect of AMC on arterial function is increased arterial stiffness.     

A comparison of six statins on the development of intimal hyperplasia in a human vein culture model.

OBJECTIVE: Intimal hyperplasia (IH) threatens the patency of up to 35% of saphenous vein (SV) bypass grafts. In addition to reducing cholesterol levels, statins may modulate smooth muscle cell proliferation and migration. Statins inhibit matrix metalloproteinase (MMP) activity. We therefore investigated the effect of six statins on neointimal formation and MMP activity in human SV organ culture. STUDY DESIGN: Human SV specimens were cultured for 14 days in the presence of six different statins and subsequently processed for measurement of neointimal thickness and MMP activity. The drug concentrations chosen corresponded to the manufacturers' Cmax. RESULTS: The six statins all significantly reduced IH development (P = 0.004) in association with reduced expression of proMMP-2 and 9 (P = 0.03) and reduced activity of activated MMP-2 and 9 (P = 0.03). CONCLUSION: This study suggests that the potential benefit of statins in reducing IH is a class effect and not confined to specific statins. The reduction of IH produced by statins may in part be due to their inhibition of MMPs.     

Contrast-enhanced abdominal computed tomography scanning and prediction of severity of acute pancreatitis: a prospective study

One hundred and fifty-two patients were admitted to a single hospital with a diagnosis of acute pancreatitis during a 31-month period. Of these, 126 patients had contrast-enhanced abdominal computed tomography (CT) scans within 72 h of admission; 92 of these attacks were clinically mild, 34 were clinically severe. A single consultant radiologist reported the scans 'blind' and noted whether pancreatic enhancement was normal, increased or decreased, and whether there was loss of peripancreatic tissue planes. The maximum anteroposterior measurement of the pancreatic head and body were multiplied together to produce a 'pancreatic size index' (cm2). Significantly more patients with severe attacks had decreased pancreatic enhancement (79 versus 58 per cent, P = 0.01) and loss of peripancreatic tissue planes (82 versus 54 per cent, P = 0.006). The median (range) pancreatic size index for clinically severe attacks was 12.8 cm2 (3.0-52.5), and for mild attacks was 6.0 cm2 (1.1-23.4), P less than 0.0001. Modified Glasgow criteria had a sensitivity of 85 per cent and specificity of 79 per cent for clinically severe attacks. A pancreatic size index of greater than or equal to 10 cm2 had a sensitivity of 71 per cent and specificity of 77 per cent for clinically severe attacks. In conclusion, although there were highly significant differences between the clinically severe and mild groups with respect to pancreatic enhancement, peripancreatic tissue planes and pancreatic size indices, these CT criteria did not improve on modified Glasgow criteria for prediction of disease severity.     

Association between aluminum accumulation and cardiac hypertrophy in hemodialyzed patients

In order to investigate the possible role of aluminum accumulation on the myocardium, 50 stable asymptomatic hemodialysis patients were studied. Patient cardiac status was assessed by echocardiography. A deferroxamine (DFO) test, together with a bone biopsy, was performed to determine the magnitude of AI accumulation. Thus, an increase in serum AI after DFO (delta AI DFO) and stainable cortical bone aluminum (SCBA) were taken as parameters of AI load. Fourteen of 50 patients had no SCBA. They differed from the 36 patients with SCBA in that they had lower left ventricular mass (LVM) (P less than 0.001), increased velocity of circumferential fiber shortening (Vcf) (P less than 0.001), and higher mitral E-F slope (P less than 0.01). In the overall population there was a mild increment in serum AI and in delta AI DFO. The duration of dialysis treatment was correlated with SCBA and delta AI DFO (P less than 0.001). A correlation was observed between LVM and delta AI DFO (P less than 0.001) and between LVM and SCBA (P less than 0.001). Multivariate correlations analysis indicated that these relationships were independent of the duration of dialysis treatment. The present data suggest that, in hemodialysis patients aluminum accumulation may be associated with increased LVM.     

Magnetic resonance imaging of cerebrotendinous xanthomatosis

Cerebrotendinous xanthomatosis is a rare familial sterol storage disease with accumulation of cholestanol and cholesterol particularly in xanthomas, bile and brain. Magnetic resonance imaging is a useful modality for imaging the affected tissues. It contributes to the evaluation and management of the disease.     

Antibody to type III group B Streptococcus in the rhesus monkey

Susceptibility to infection due to intra-amniotic type III group B streptococcal infection was studied in 27 rhesus monkeys. Sera from mothers and their offspring were tested to determine the concentration of antibody to the native type III group BStreptococcus antigen. Among 17 controls there was a statistically significant association between the concentration of maternal antibody prior to infection and both the neonatal survival rate and survival time (P < 0.05). Neonatal survival was decreased to ≤6 hours (P = 0.005) if the maternal antibody concentration was <0.5 μg/ml. Modified immune serum globulin was given intravenously to the mothers prior to intra-amniotic infection with (five animals) or without (five animals) neonatal modified immune serum globulin. Neither of the modified immune serum globulin groups demonstrated a significant reduction in the neonatal mortality rate; however, the addition of the modified immune serum globulin provided protection against rapid neonatal death among those animals born to mothers which had low or no detectable antibody. All maternal groups developed a significant increase in the concentration of antibody in postpartum sera. These results indicate that both naturally acquired and passive (modified immune serum globulin) antibodies to type III group BStreptococcus antigen are partially protective against intra-amniotic infection.     

Cooperative interactions at [3H]kainic acid binding sites in rat and human cerebellum.

Inhibition of the specific binding of [3H]kainic acid was studied in membranes isolated from rat and human cerebellum; the sequence of potencies in both species were: kainic acid greater than L-glutamic acid greater than dihydrokainic acid greater than D-glutamic acid. Whereas the Hill coefficient for unlabelled Kainate was 1.0, dihydrokainic acid and D- and L-glutamic acids exhibited negative cooperativity with Hill coefficients of near 0.5. This allosteric interaction of glutamic acid at the kainic acid recognition site suggests a biochemical correlate for the synergistic effects of these compounds in vivo.