Follow up study of 70 patients with renal artery stenosis treated by percutaneous transluminal dilatation.

Between April 1978 and April 1981, 70 patients with hypertension and renal artery stenosis were treated by percutaneous transluminal arterial dilatation. Selection of the patients was based solely on arteriographic criteria. Arteriography after dilatation showed considerable widening of the stenosed area in all patients. In 65 patients the effect of treatment on the blood pressure was assessed during follow up periods of one to four years. In 14 of these patients the hypertension was cured, in 29 it was improved, and in 22 there was no change. Patients with fibromuscular lesions benefited distinctly more than did those with atheromatous stenosis, only one of the 21 patients with fibromuscular lesions showing no change as compared with 21 of the 44 patients with atheromatous lesions. The only serious complication encountered was microcholesterol emboli, which developed in two patients with severe atheromatous lesions of the aorta. In the atheromatous group age and overall renal function had no influence on the blood pressure response. In the subgroup of patients with a unilateral lesion the renal vein renin ratios and asymmetrical curves obtained by renography had only a very limited predictive value. In experienced hands percutaneous transluminal arterial dilatation is relatively safe, and this study suggests that it should be attempted in all patients with renal artery stenosis. Only in patients with severe atheromatosis of the aorta should the risk associated with the catheterisation be weighed against the 50% or so chance of benefit from the procedure.     

Influence of proteinuria on vascular disease,blood pressure,and lipoproteins in insulin dependent diabetes mellitus.

Patients with insulin dependent diabetes mellitus who develop proteinuria may die prematurely, whereas those who do not develop this complication have a comparatively normal life span. The excess mortality in diabetics with proteinuria is from cardiovascular as well as renal disease, but the reason is unclear. Risk factors for vascular disease were therefore assessed in 22 insulin dependent diabetics with proteinuria, but not renal failure, who were matched for sex, age, duration of diabetes, and glycated haemoglobin (HbA1) values with a similar number who had normal urinary albumin excretion rates. Macrovascular disease (ischaemic heart disease and peripheral vascular disease) was present in 10 patients with proteinuria but in only three with normal albumin excretion rates, and proliferative retinopathy was detected in 11 and four patients in the two groups. There was no significant excess of smokers in the group with proteinuria. Blood pressure was, however, higher in the patients with proteinuria--mean systolic pressure 161 (SD 18) mm Hg compared with 135 (19) mm Hg (95% confidence interval of difference between means 15 to 38 mm Hg); mean diastolic pressure 90 (SD 12) mm Hg compared with 79 (15) mm Hg (confidence interval 3 to 19 mm Hg). The concentration of serum high density lipoprotein (HDL) cholesterol isolated by precipitation was lower in the patients with proteinuria (confidence interval 0.02 to 0.41 mmol/l). Their concentration of HDL2 cholesterol isolated by ultracentrifugation was also decreased (confidence interval 0.02 to 0.40 mmol/l), whereas HDL3 cholesterol tended to be increased (confidence interval -0.01 to 0.23 mmol/l). There was also a trend for serum cholesterol concentrations to be higher in the presence of proteinuria (confidence interval -0.39 to 1.20 mmol/l). The aggregation of risk factors for atherosclerosis in insulin dependent diabetes mellitus complicated by proteinuria helps to explain the increased prevalence of ischaemic heart disease and peripheral vascular disease reported in these patients. Early renal disease in insulin dependent diabetes may have an important role in hypertension and altered lipoprotein metabolism.     

Genetic analysis of fluvastatin response and dyslipidemia in renal transplant recipients

The Assessment of Lescol in Renal Transplantation clinical trial demonstrated the efficacy of fluvastatin in reducing cardiovascular (CV) disease in renal transplant recipients. The study included a voluntary pharmacogenetic component, enrolling 1,404 patients, which allowed association testing of baseline measures and longitudinal analysis of the 707 fluvastatin-treated and 697 placebo-treated individuals. A candidate gene approach, examining 42 polymorphisms in 18 genes, was used to test for association between selected polymorphisms and major adverse cardiac events, graft failure, change in LDL and HDL cholesterol, and baseline LDL and HDL cholesterol. Reported associations between cholesteryl ester transfer protein (CETP) and baseline HDL cholesterol were replicated, with four previously implicated single nucleotide polymorphisms significantly associated in males and one in females; tests of reported associations between CETP and CV disease yielded varying results. We found no evidence for genetic factors affecting fluvastatin response. Polymorphisms in 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) previously reported to affect the efficacy of pravastatin did not show a similar effect on the reduction of LDL cholesterol by fluvastatin.     

Lecithin cholesterol acyltransferase activity in chronic nephropathies

The authors present data from a group of 55 patients suffering from chronic renal diseases. Twenty-two were treated by haemodialysis; the rest had serum creatinine levels ranging from normal to 950 mumol/l. The molar esterification rats [MER] and total cholesterol [TCH] values decreased parallel to the gradual extinction of renal function. A reduced fractional esterification rate [FER] was found in about two thirds of the dialysed patients and in about half of those whose kidney function was still relatively well preserved. It can thus be concluded that reduction of FER values indicative of a disturbance of cholesterol metabolism can already be detected in the early stages of chronic nephropathies.     

DNA methylation status of the methylenetetrahydrofolate reductase gene promoter in peripheral blood of end-stage renal disease patients

End-stage renal disease (ESRD) is one of the main causes of morbidity and mortality worldwide. DNA methylation is a major epigenetic modification of the genome that has the potential to silence gene expression. Methylenetetrahydrofolate reductase (MTHFR) gene inactivation was recognized as a predisposing factor of hyperhomocysteinemia in renal patients. The current study aimed to determine the methylation status within the MTHFR promoter region in DNA isolated from peripheral blood of ESRD patients and controls and the correlation of this methylation with the clinical and biochemical characteristics in ESRD patients. Ninety-six ESRD patients and 96 healthy ethnically, age and gender matched controls were included within the study. MTHFR promoter methylation was assessed using methylation specific polymerase chain reaction. The frequency of MTHFR methylation was significantly higher in ESRD patients than in controls (P = 0.003), additionally, MTHFR methylation was associated to a decrease in estimated glomerular filtration rate, serum high-density lipoprotein cholesterol level and an increase in both serum total cholesterol and low-density lipoprotein cholesterol levels. Data generated from this study suggest the possible involvement of MTHFR promoter methylation in the pathogenesis of ESRD and support a new dimension of MTHFR inactivation.     

PGE1 inhibited PMN attachment to air emboli in vivo during infusion of ZAP without preventing lung injury.

Prostaglandin E1 (PGE1) treatment of neutrophils inhibits their adherence to substrates in vitro, including endothelial cell monolayers. Demonstration that PGE1 inhibits neutrophil adherence in vivo in the lung, however, is complicated by PGE1 effects on cells other than neutrophils, such as endothelial cells. To determine whether PGE1 inhibits neutrophil adherence properties in vivo, we used air emboli as intravascular targets for neutrophil attachment. Four experimental conditions were studied in anesthetized and awake sheep that were treated with 1) PGE1 and air emboli, 2) saline and air emboli, 3) PGE1 and zymosan-activated plasma (ZAP) + air emboli, and 4) saline and ZAP + air emboli. PGE1 (30 ng.kg-1.min-1) or saline was infused continuously 1 h before and 1 h during the infusion of air emboli (group 1; n = 13 sheep) or ZAP + air emboli (group 2; n = 13 sheep). The number of neutrophils (PMNs) attached to air emboli in four anesthetized sheep per condition was significantly less in sheep given PGE1 and ZAP + air emboli [8 +/- 3 (SD) PMNs/mm of embolus perimeter] than in the other three conditions (14-21 PMNs/mm; P less than 0.05). Repeated experiments in five awake sheep per group showed that PGE1 treatment did not prevent increased lung lymph protein clearance in either group compared with saline treatment. We conclude that PGE1 specifically inhibited attachment of ZAP-activated neutrophils to air emboli in vivo. The lack of pathophysiological protection suggests that PGE1-induced alterations in neutrophil attachment properties were independent of other cellular activation responses.     

Antioxidant enzymes and lipoperoxide in blood in uremic children and adolescents

To determine whether oxidant-antioxidant balance is altered in chronic renal failure, antioxidant enzymes and lipid peroxide in peripheral blood cells and lipid peroxide in plasma were measured. Nine children and adolescents maintained on hemodialysis (HD), 9 on continuous ambulatory peritoneal dialysis (CAPD), and 14 controls were studied. Lipid peroxide was assayed fluorimetrically as thiobarbituric acid-reactive substances, superoxide dismutases by radioimmunoassays. Both manganese and copper-zinc superoxide dismutases in lymphocytes and monocytes in the HD and CAPD patients, and manganese superoxide dismutase in polymorphs in the HD patients were higher than in the controls. Copper-zinc superoxide dismutase, glutathione peroxidase, and catalase in erythrocytes were unaltered. The lipid peroxide level in plasma in the dialyzed patients was increased, whereas those in polymorphs and lymphocytes were unaltered. Triglyceride and total cholesterol in plasma in the dialyzed patients were also increased. The plasma lipid peroxide in the patients correlated with the triglyceride and total cholesterol level. This is the first study in which manganese superoxide dismutase is measured in nucleated cells of the patients with chronic renal failure. The present results suggest that increased superoxide dismutases protect against oxidative stress induced by chronic renal failure in nucleated cells but in neither erythrocytes nor plasma.     

Association of Dyslipidemia with Renal Outcomes in Chronic Kidney Disease

Dyslipidemia is highly prevalent in patients with chronic kidney disease (CKD) and the relationship between dyslipidemia with renal outcomes in patients with moderate to advanced CKD remains controversial. Hence, our objective is to determine whether dyslipidemia is independently associated with rapid renal progression and progression to renal replacement therapy (RRT) in CKD patients. The study analyzed the association between lipid profile, RRT, and rapid renal progression (estimated glomerular filtration rate [eGFR] slope <−6 ml/min/1.73 m²/yr) in 3303 patients with stages 3 to 5 CKD. During a median 2.8-year follow-up, 1080 (32.3%) participants commenced RRT and 841 (25.5%) had rapid renal progression. In the adjusted models, the lowest quintile (hazard ratios [HR], 1.23; 95% confidence interval [CI], 1.01 to 1.49) and the highest two quintiles of total cholesterol (HR, 1.25; 95% CI, 1.02 to 1.52 and HR, 1.35; 95% CI, 1.11 to 1.65 respectively) increased risks for RRT (vs. quintile 2). Besides, the highest quintile of total cholesterol was independently associated with rapid renal progression (odds ratio, 1.36; 95% CI, 1.01 to 1.83). Our study demonstrated that certain levels of dyslipidemia were independently associated with RRT and rapid renal progression in CKD stage 3–5. Assessment of lipid profile may help identify high risk groups with adverse renal outcomes.     

Increased rate of cholesterologenesis--a possible cause of hypercholesterolemia in experimental chronic renal failure in rats.

Hypercholesterolemia plays an important role in the lipid abnormalities in chronic renal failure (CRF). It is thought to contribute to both a progression of renal failure and atherosclerosis. Despite intensive research, the etiopathogenesis of hypercholesterolemia in CRF patients is still obscure. The present study was designed to evaluate the possible role of cholesterol overproduction in the development of hypercholesterolemia associated with experimental CRF. We found that plasma total cholesterol and cholesterol distributed in VLDL, LDL and HDL concentrations were significantly enhanced in CRF rats. Simultaneously, the rate of liver cholesterol biosynthesis in vivo (measured by determining the incorporation of tritium from tritiated water intraperitoneally injected into cholesterol ), liver microsomal 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity and liver HMG-CoA reductase mRNA presence were elevated. Significant increases in activity of liver malic enzyme, glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, NADPH-producing enzyme (required for cholesterol synthesis) have also been observed in CRF rats. In conclusion, the increased rate of liver cholesterol biosynthesis due to increase of HMG-CoA reductase and NADPH-producing enzyme gene expression could be one of the possible causes of hypercholesterolemia in CRF animals.     

肾移植术后患者同型半胱氨酸、肾功能和血脂水平的变化及其相关性分析

目的:分析肾移植术后患者血清的同型半胱氨酸(Hcy)、肾功能和血脂水平的变化和相关性,探讨其在肾移植术后评价肾功能的应用价值。方法:将2013年10月~2016年9月就诊于我院确诊慢性肾衰并进行肾移植手术的300例术后随访患者作为观察组,选择同期健康志愿者100例作为对照组。检测并比较两组Hcy、总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)水平。根据观察组患者Hcy水平的不同将其分成Hcy正常组与Hcy异常组,并对比两组患者的血脂指标水平;测定半胱氨酸蛋白抑制剂C(CysC)的水平并计算肾小球滤过率(eGFR);对观察组血清Hcy与eGFR值、血脂指标水平进行相关性分析,并采用Logistic回归分析分析观察组肾移植术后eGFR下降的影响因素。结果:观察组患者的血清Hcy、TC、TG、HDL-C、LDL-C水平均明显高于对照组(P0.05)。Hcy异常组血清LDL-C水平明显高于Hcy正常组,而HDL-C水平明显低于Hcy正常组(P0.05)。观察组患者血清Hcy与eGFR、HDL-C水平呈负相关关系(r=-0.573、-0.414,P0.05);与TG水平呈正相关(r=0.432,P0.05),与TC、LDL-C无相关(P0.05)。多元Logistic回归分析显示,Hcy、TG、LDL-C水平均与患者eGFR下降有关(P0.05)。结论:在肾移植术后,慢性肾衰患者的TG、LDL-C、Hcy水平均升高,且伴有eGFR水平的降低;肾移植术后肾功能的改变与血清TG、LDL-C、Hcy水平相关;检测肾移植患者血脂指标、Hcy的水平可以评估移植肾功能受损情况。     

12 alpha-hydroxylase activity in human liver and its relation to cholesterol 7 alpha-hydroxylase activity.

Interruption of the enterohepatic circulation by cholestyramine causes a several-fold increase in bile acid synthesis, reflected in a stimulation of cholesterol 7 alpha-hydroxylase activity; the synthesis of cholic acid being stimulated to a greater extent than chenodeoxycholic acid. It is not known if this preferential increase in cholic acid is due to an increase of the 12 alpha-hydroxylase activity. The present study aimed at investigating the 12 alpha-hydroxylase activity and its relation to cholesterol 7 alpha-hydroxylase activity in liver microsomes of patients with different levels of cholesterol 7 alpha-hydroxylase activity. Liver biopsies were obtained from four gallstone-free patients, and seven untreated and two cholestyramine-treated gallstone patients undergoing cholecystectomy, and four patients with Crohn's disease undergoing intestinal resection. The combined group of cholestyramine-treated and ileum-resected patients had four times higher cholesterol 7 alpha-hydroxylase activity and two times higher 12 alpha-hydroxylase activity than the other patients. A positive correlation was obtained between cholesterol 7 alpha-hydroxylase activity and 12 alpha-hydroxylase activity (r = +0.69; n = 16). These results indicate that the increased ratio between the synthesis of cholic acid and chenodeoxycholic acid during cholestyramine treatment is due to a compensatory increase of the 12 alpha-hydroxylase activity.     

Effects of ramipril and valsartan on proteinuria and renal function in patients with nondiabetic proteinuria

The renin-angiotensin system is involved in the progression of chronic renal disease of both diabetic and nondiabetic origin. The angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have been demonstrated to reduce urinary protein excretion and attenuate the development of renal injury. This prospective, randomized, 12-month study assessed the effects of ramipril (N = 23) vs. valsartan (N = 22) vs. combination of ramipril and valsartan (N = 26) on proteinuria, renal function and metabolic profile in 71 patients with nondiabetic proteinuria with normal or slightly impaired renal function. Monotherapy with ramipril or valsartan and combination of these two drugs significantly reduced proteinuria, serum creatinine, cholesterol and triglycerides as well as systolic and diastolic arterial blood pressure. There was no significant difference among three study groups according to reduction of arterial blood pressure, serum cholesterol and triglycerides. At one year, a significant reduction in serum creatinine was recorded in all three study groups, whereas at 3 and 6 months a statistically significant reduction in serum creatinine was only observed in patients on combination therapy. In addition, at 3 months the reduction of proteinuria was significantly greater in patients on combination therapy than in those on either monotherapy. These results indicated the combination therapy with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers to be more efficacious than either monotherapy in reducing proteinuria and serum creatinine level in the first 3 (proteinuria and serum creatinine) or 6 (serum creatinine) months of treatment.     

HMGCoA reductase and cholesterol 7 alpha-hydroxylase in human liver

The activities of HMGCoA reductase and cholesterol 7 alpha-hydroxylase were assayed in liver biopsies of patients with or without cholestyramine treatment. The active dephosphorylated form of HMGCoA reductase and the activity of cholesterol 7 alpha-hydroxylase were under the detection limits in untreated subjects. After cholestyramine treatment activities of both enzymes were stimulated and the active form of HMGCoA reductase became detectable in four out of the five tested patients. In two subjects who received cholestyramine, the effect of exogenously added [4-14C] cholesterol on cholesterol 7 alpha-hydroxylase was tested. In the presence of Tween 80, the detergent by which [14C]cholesterol was suspended, the enzyme activity was profoundly inhibited and synthesis of 7 alpha-hydroxycholesterol was extremely low.     

Cholesterol and its lipoprotein fraction in serum and bile of patients with cholelithiasis]

Total cholesterol, HDL, LDL and triglycerides were assayed in the blood serum and bile from the liver and gallbladder of both normal individuals and patients with cholelithiasis. It was found that all assayed parameters are significantly higher in patients with cholelithiasis. An increase in total cholesterol and HDL was seen in the bile from the liver whereas an increase in the level of unstable LDL by about four fold with simultaneous decrease in HDL level were found in the bile from the gallbladder. These differences in lipoprotein fractions level in patients with cholelithiasis indicate systemic disorders in cholesterol metabolism.     

Analysis of mechanical parameters on the thromboembolism using a patient-specific computational model

Ischemic stroke is a major cause of death and long-term disabilities worldwide. In this paper, we aim to represent a comprehensive simulation of the motion of emboli through cerebrovascular network within patient-specific computational model. The model consists of major arteries of the circle of Willis reconstructed from magnetic resonance angiography images, pulsatile flow and emboli with different sizes and material properties. Here, the fluid–structure interactions method was used to simulate the motion of deformable and rigid emboli through cerebral arteries. Hemodynamic changes in the circle of Willis due to the entrance of embolus are observed. The effect of material properties on the distribution ratio and dynamics of motion of the emboli in the cerebral arterial network is also analyzed. Our results reveal that as the rigidity of emboli increases, higher proportion of them tend to enter to the larger arteries (e.g., middle cerebral artery). Scrutinizing the amount of stress acting on the emboli represented in this paper can broaden our understanding of the rheological phenomenon (e.g., lysis or growth of emboli during embolism). The approach of considering different material properties of the thrombus in a patient-specific computational model not only enable us to better understand the roll of biomechanical parameters causing the embolism, but also lead to a better clinical decision making to manage patients with stroke.     

Statin therapy for prevention and treatment of acute and chronic cardiovascular disease: update on recent trials and metaanalyses

PURPOSE OF REVIEW: To summarize the evidence from recent clinical trials and metaanalyses on the efficacy of statin therapy to reduce death, myocardial infarction and stroke, and to review the effects of statins in patients with low LDL cholesterol, diabetes, end-stage renal disease, and acute coronary syndrome. RECENT FINDINGS: In large metaanalyses of randomized controlled trials relative risk reductions from statins compared with placebo for patients with manifest or with risk factors for coronary artery disease were 13% for overall mortality, 26% for fatal and nonfatal myocardial infarction, and 18% for fatal and nonfatal stroke. Evidence from large trials suggests that patients with type II diabetes compared with patients without diabetes have similar risk reductions from statins for cardiovascular events, but this benefit is not seen in patients with diabetes and end-stage renal disease. In patients with acute coronary syndrome, early treatment with high-dose atorvastatin reduces cardiovascular morbidity after the first 4 months following the event, but the impact on mortality endpoints remains less clear. Results from recent trials in patients with stable coronary artery disease or type II diabetes suggest that statins provide benefit at considerable low LDL cholesterol levels. Therefore, target values for LDL cholesterol of less than 1.8 mmol/l (<70 mg/dl) should be considered for all patients with coronary artery disease or equivalent coronary risk. SUMMARY: For patients at high risk of coronary artery disease there is growing evidence for the concept of 'the lower, the better' regarding LDL cholesterol levels. Ongoing trials are further investigating the safety of lower target values in patients at various risk of coronary artery disease.     

Cellular Cholesterol Transport Proteins in Diabetic Nephropathy

Background

Lipid accumulation has been shown to accelerate renal injury, and the intracellular accumulation of lipids may be caused by alterations in synthesis as well as lipid uptake and efflux. We have investigated the role of cellular cholesterol transport proteins including adenosine triphosphate binding cassette transporter A1 (ABCA1), G1 (ABCG1) and scavenger receptor class B type I (SR-BI) in diabetic nephropathy.

Methods

Protein expression and the ability to mediate cholesterol efflux of ABCA1, ABCG1 and SR-BI was determined in human renal mesangial cells and proximal tubular epithelial cells cultured under normal or high glucose conditions. Renal expression of these cholesterol transporters was examined in a murine model of streptozotocin-induced type 1 diabetes.

Results

ABCA1, ABCG1 and SR-BI were expressed in both human renal mesangial cells and proximal tubular epithelial cells, and mediated cholesterol efflux to apolipoprotein AI and HDL. In vitro, hyperglycemia reduced the expression and the ability to mediate cholesterol efflux of all three cholesterol transporters (p<0.05). In vivo studies showed that intra-renal accumulation of lipids was increased in diabetic mice, particularly in mice with nephropathy. This was associated with a significant reduction in the expression of ABCA1, ABCG1 and SR-BI in the kidneys. These changes were already seen in diabetic mice without nephropathy and preceded the development of nephropathy. Diabetic mice with nephropathy had the lowest level of these cholesterol transporters.

Conclusion

Inducing diabetes with streptozotocin significantly reduced renal expression of ABCA1, ABCG1 and SR-BI. Defects in cholesterol export pathway in renal cells could therefore promote cholesterol accumulation and might contribute to the development of diabetic nephropathy.     

Pulmonary Embolectomy

Embolectomy was carried out in eight patients with pulmonary emboli. Angiographic diagnosis was obtained in six, and in two cases pulmonary angiography could not be done because of the very critical condition of the patients. In the latter two, diagnosis was made based only on clinical findings. Two patients died in the operating room (25 percent). Six patients were discharged in good condition.It is emphasized that pulmonary embolectomy should be done in cases of pulmonary emboli when a clinical status of shock is present (systolic blood pressure less than 80 mm of mercury and the patient in low cardiac output syndrome) and when there is no response to medical treatment regardless of the degree of obstruction in the pulmonary arterial tree.     

Fibrosing Alveolitis Associated with Renal Tubular Acidosis

The discovery of a case of renal tubular acidosis and fibrosing alveolitis led to the investigation of 19 further patients. Abnormal pulmonary function tests were found in a further four patients with overt renal tubular acidosis and in four out of eight patients with “incomplete” renal tubular acidosis. The response to an ammonium chloride test in seven patients with cryptogenic fibrosing alveolitis was normal. Those patients with a defect of both renal acidification and pulmonary gas transfer had concurrent autoimmune diseases such as Sjögren''s syndrome and primary biliary cirrhosis. It is suggested that the renal and pulmonary abnormalities may be part of a systemic disorder capable of affecting many organs. Moreover, hyperglobulinaemia and autoantibodies in these patients further suggests that immunological mechanisms are concerned in the pathogenesis of these abnormalities.     

Kidney function after renal arterial embolism

Seven patients with atrial fibrillation had acute unilateral renal pain associated with suppression of function in the affected kidney. This was ascribed to renal embolism. Arteriography performed in four patients showed abnormalities in the renal arterial tree in three, though thrombus in a main artery was present in only one.Considerable function returned spontaneously to the affected kidney in six patients as judged by intravenous pyelography or renography. In two patients the sole functioning kidney was affected, leading to acute oliguric renal failure, but renal function recovered in each case. The routine use of anticoagulants in persistent atrial fibrillation is justified by such cases.