The role of Chlamydia in coronary heart disease-fact or fiction?
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Animals↗
Biomedical subjects
C Wanner
Publications and source records attributed to C Wanner.
Non-insulin-dependent diabetes mellitus and hypertriglyceridemia impair lipoprotein metabolism in chronic hemodialysis patients.
Patients with diabetes mellitus undergoing chronic hemodialysis treatment have the worst outcome on dialysis due to an increased rate of cardiovascular complications. Nearly all patients present with dyslipidemia, a prominent vascular risk factor, probably responsible for the high rate of vascular injury. Since both uremia and diabetes predispose to hypertriglyceridemia, the present study was conducted to investigate the influence of diabetes mellitus and/or hypertriglyceridemia on lipoprotein metabolism in hemodialysis patients. LDL was isolated and characterized from hyper- and normotriglyceridemic diabetic and nondiabetic hemodialysis patients (n = 40; 10 in each group); also, LDL-receptor-dependent uptake and intracellular cholesterol metabolism were studied in HepG2 cells. In addition, scavenger-receptor-mediated uptake was examined in mouse peritoneal macrophages. LDL isolated from nondiabetic normotriglyceridemic hemodialysis patients exhibited impaired cellular uptake via the LDL receptor. Additionally, intracellular sterol synthesis was less inhibited and cholesterol esterification was reduced compared with LDL from healthy control subjects. Reduction of catabolic capacities was more marked in hemodialysis patients who were either diabetic or hypertriglyceridemic and even more pronounced in patients presenting with a combination of both diabetes and hypertriglyceridemia. Hypertriglyceridemic and diabetic patients showed reduced lipase activity and increased LDL oxidation. Furthermore, they accumulated a fraction of small, dense LDL, and LDL was predominantly taken up via the scavenger-receptor pathway in peritoneal macrophages. This study elucidates the distinct influence of diabetes and/or hypertriglyceridemia in hemodialysis patients on cellular LDL metabolism via specific and nonspecific metabolic pathways. Furthermore, it underscores the cumulative impact of these pathologic entities on impairment of lipoprotein metabolism and increase of cardiovascular risk.
Aged↗
The influence of vascular space involvement on the prognosis of patients with stage IB cervical carcinoma: correlation of results from hematoxylin and eosin staining with results from immunostaining for factor VIII-related antigen.
BACKGROUND: There is controversy over the question of whether the involvement of vascular spaces influences the prognosis of patients with carcinoma of the uterine cervix. The aim of the current study was to compare patterns of vascular space involvement determined by hematoxylin and eosin (H & E) staining with those patterns determined by immunostaining for factor VIII-related antigen (F8-RA) with regard to their prognostic impact on the disease free survival (DFS) and overall survival (OS) of patients with clinical Stage IB cervical carcinoma. Staining for F8-RA is known to highlight blood vessels predominantly, whereas the presence of tumor cell emboli in vascular spaces of H & E-stained sections mainly indicates lymphatic vessel invasion. METHODS: The authors analyzed data on 163 patients for whom vascular space involvement (VSI) was determined by H & E (VSI/H & E) and F8-RA (VSI/F8) staining from the same block in two separate runs. RESULTS: The median follow-up period was 85 months (range, 5-170 months). The 25% quantile for OS was 109 months (median not reached; range, 5-170 months). The overall rates of VSI/H & E and VSI/F8 were 29.4% and 24.5%, respectively. The findings obtained by H & E and F8-RA staining were concurrent in 60.7% of cases. Lymph node involvement and VSI/F8 remained independent prognostic factors for DFS and OS. Due to a highly significant correlation of pelvic lymph node status with both VSI/H & E and tumor size, the last two parameters failed to retain a significant value. For lymph node negative patients, the estimated OS probability was 92% for those without VSI/F8 and 62% for those with VSI/F8. CONCLUSIONS: VSI/F8 may provide additional information on the outcome of clinical Stage IB cervical carcinoma. Lymph node negative patients with VSI/F8 positive tumors may benefit from more intense postsurgical treatment. Further trials involving larger series of patients are necessary to confirm these findings.
Adenocarcinoma↗
[Proteinuria].
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Cardiovascular Diseases↗
Tumor angiogenesis in stage IB cervical cancer: correlation of microvessel density with survival.
OBJECTIVE: Because angiogenesis is considered essential for tumor growth and the development of metastasis, we assessed the correlation of microvessel density with overall survival in patients with clinical stage IB carcinoma of the uterine cervix. STUDY DESIGN: Histologic slides were immunostained for factor VIII-related antigen. Microvessel density was determined within each tumor by enumeration under a light microscope at 200x magnification and an examination area of 0.25 mm2. The Cox proportional hazards model was used for multivariate analysis. RESULTS: In 166 patients with stage IB cervical cancer the 5-year survival was as follows: 89.7% in 102 patients whose tumors had a microvessel density < or =20/field, and 63.0% in 64 patients whose tumors had a microvessel density >20/field (log rank p < 0.0001). In the multivariate Cox model microvessel density, lymph node involvement, tumor size, and the application of radiation therapy remained independent prognostic factors for survival, whereas lymphatic vascular space involvement failed to retain a significant value. CONCLUSION: High microvessel density adversely influences patients' survival in clinical stage IB cervical cancer and identifies patients with negative nodes at risk for relapse.
Adult↗
Glyc-oxidized LDL impair endothelial function more potently than oxidized LDL: role of enhanced oxidative stress.
Hypercholesterolemia is associated with impairment of endothelial function due to increased levels of LDL. In diabetic patients, however, attenuation of endothelial function occurs even under normocholesterolemic conditions. Here we assessed whether glycation of LDL potentiates their influence on endothelial function, with particular emphasis on the oxidizability of LDL and the role of O2-. Human LDL was glycated by dialyzation for 7 days against buffer containing 200 mmol/l glucose, or sham-treated without glucose, and oxidized by incubation with Cu2+. Glycation significantly enhanced the oxidizability of LDL, as detected by diene formation and by electrophoretic mobility (27.5 mm for oxidized LDL vs. 34 mm for oxidized glycated LDL at 20 h of oxidation). Isolated rings of rabbit aorta were superfused with physiological salt solution, and isometric tension was recorded. Incubation of the aortic rings with sham-treated or with glycated LDL, not oxidized, had no influence on acetylcholine-induced, endothelium-dependent relaxation. Exposure of the aortic rings to oxidized non-glycated LDL caused a significant inhibition (30% at 1 microM acetylcholine) of the endothelium-dependent relaxation only in the presence of diethyl-dithiocarbamate (DDC), an inhibitor of the endogenous superoxide dismutase (SOD). Incubation of aortic rings with oxidized glycated LDL attenuated endothelium-dependent relaxation even in the absence of DDC (by 31% at 1 microM acetylcholine). The presence of DDC potentiated the inhibition of relaxation (65% inhibition at 1 microM acetylcholine), and co-incubation with exogenous SOD and catalase prevented the inhibition of relaxation, indicating a mediator role of O2-. Endothelium-independent relaxation induced by forskolin was unaffected by any of the lipoproteins. Using a chemiluminescence assay, significantly increased O2- production of aortic rings pretreated with oxidized glycated LDL (4101 +/- 360 counts/s) in comparison to control rings (753 +/- 81 counts/s) or arteries pretreated with oxidized non-glycated LDL (2358 +/- 169 counts/s) could be detected, suggesting that enhanced NO-inactivation by O2- could be the underlying mechanism for the stronger impairment of endothelium-dependent dilations by oxidized glycated LDL. Glycation increases the oxidizability of LDL and potentiates its endothelium-damaging influence. The likely mechanism for attenuation of endothelium-dependent dilations is increased formation of O2-, resulting in inactivation of nitric oxide. This mechanism may play an important role in diabetic patients and may contribute to disturbed organ perfusion.
Animals↗
Color-coded and spectral Doppler flow in breast carcinomas--relationship with the tumor microvasculature.
The phenomenon of tumor angiogenesis is an important aspect of understanding tumor biology. Studies in breast carcinoma have shown microvessel density (MVD) assessed by immunohistochemistry to be of prognostic importance in primary breast cancer. On the other hand, recently developed highly sensitive color-coded Doppler techniques offer a noninvasive method to examine neovascularisation in breast tumors. The purpose of this study was to determine the relationship between Doppler flow parameters and microvessel count assessed by immunohistochemistry. Fifty-three patients with primary breast cancer were examined preoperatively with color-coded Doppler ultrasound. The obtained Doppler frequency spectra were analyzed for peak systolic flow velocity (Vmax). Following surgery, paraffin-embedded microsections were immunohistochemically stained for factor VIII-related antigen. Tumor angiogenesis was assessed by microvessel count under light microscopy. Undifferentiated tumors correlated with high MVD (p=0.009) whereas other clinicopathological parameters were not associated with MVD. Color Doppler signals were detected in 50 out of 53 breast tumors. Evaluation of tumor flow velocity with various clinicopathological parameters showed a significant correlation with tumor size (p=0.0001) and lymph node metastasis (p=0.02). However, there was no significant correlation between MVD and intratumoral blood flow velocity assessed by color-coded Doppler. Our findings showed that Doppler flow measurement did not correlate with the extent of tumor angiogenesis of breast cancer. The present data give circumstantial evidence that microvessel count assessed by immunohistochemistry reflects the microvascular network, whereas tumor vasculature documented by Doppler ultrasound supplies information on the macrovasculature.
Adult↗
Smoking as a risk factor for end-stage renal failure in men with primary renal disease.
BACKGROUND: It is not known whether smoking increases the risk of end-stage renal failure (ESRF) in patients with primary renal disease. METHODS: We performed a retrospective multicenter case-control study including 582 patients from nine centers in Germany, Italy and Austria. The diseases investigated were IgA glomerulonephritis (IgA-GN) as a model of inflammatory renal disease and autosomal dominant polycystic kidney disease (ADPKD) as a model of non-inflammatory renal disease. Cases were patients who had progressed to ESRF and controls were patients who were not in ESRF, that is, whose serum-creatinine failed to progress to >3 mg/dl during the observation period and who did not require renal replacement therapy. Matching for renal disease (IgA-GN, ADPKD), gender, age at renal death and region of residence resulted in 102 individually matched pairs (IgA-GN N = 54, ADPKD N = 48). Multiple conditional logistic regression was used to estimate adjusted odds ratios for independent tobacco effects. RESULTS: In men (matched pairs: IgA-GN N = 44, ADPKD N = 28), a significant dose-dependent increase of the risk to progress to ESRF was found (non-adjusted). The baseline risk was defined as <5 pack-years (PY): (i) 5 to 15 PY, odds ratio 3.5 (95% CI 1.3 to 9.6), P = 0.017; (ii) >15 PY = 5.8 (2.0 to 17), P = 0.001. Systolic blood pressure, ACE inhibitor treatment and age at diagnosis emerged as potential confounders. After adjustment, the risk for ESRF in men with >5 PY was highly increased for patients without ACE inhibitor treatment [10.1 (2.3 to 45), P = 0.002] but not with ACE inhibitor treatment [1.4 (0.3 to 7.1), P = 0.65]. CONCLUSION: Smoking increases the risk of ESRF in men with inflammatory and non-inflammatory renal disease.
Adult↗
The patient with asymptomatic acute renal failure--renal biopsy gives the diagnosis.
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Acute Kidney Injury↗
Thrombotic microangiopathy: a challenge with uncertain outcome.
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Adult↗
Causes of coronary heart disease in patients on renal replacement therapy.
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Animals↗
Oxidized LDL and Lp(a). Preparation, modification, and analysis.
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Arteriosclerosis↗
D-thyroxine reduces lipoprotein(a) serum concentration in dialysis patients.
Uremia raises lipoprotein(a) (Lp(a)) serum concentration and the risk of arteriosclerosis in dialysis patients. The treatment of high Lp(a) levels is not satisfactory today. The decrease of Lp(a) in hypothyroid patients on L-T4 therapy raised the question of whether dextro-thyroxine (D-thyroxine) reduces not only serum cholesterol, but also Lp(a) serum concentration. In a single-blind placebo-controlled study, the influence of D-thyroxine therapy on Lp(a) serum concentration was evaluated in 30 hemodialysis patients with elevated Lp(a) serum levels. Lp(a) was quantified in parallel by two methods, i.e., rocket immunoelectrophoresis and nephelometry, and apo(a) isoforms were determined by a sensitive immunoblotting technique. Regardless of the apo(a) isoforms, 6 mg/d D-thyroxine reduced elevated Lp(a) levels significantly by 27 +/- 13% in 20 dialysis patients (P < 0.001) compared with 10 control subjects (-9.9 +/- 8.4%). In parallel, D-thyroxine therapy significantly lowered total cholesterol (P < 0.001), LDL cholesterol (P < 0.001), and LDL cholesterol/HDL cholesterol ratio (P < 0.01); raised T4 and T3 serum levels; and suppressed thyroid-stimulating hormone secretion without causing clinical symptoms of hyperthyroidism in any of the patients. D-Thyroxine reduces elevated serum Lp(a) concentration in dialysis patients. The effect in nondialysis patients can be expected but remains to be proven.
Aged↗
Impairment of endothelial function induced by glyc-oxidized lipoprotein a [Lp(a)].
UNLABELLED: Diabetic patients develop endothelial dysfunction early in the course of the disease. Atherogenic lipoproteins such as LDL and Lp(a) are important risk factors for endothelial dysfunction and undergo nonenzymatic glycation in hyperglycaemia. Here we assessed whether glycation of Lp(a) potentiates its damaging influence on endothelial function. Human Lp(a) was glycated by dialyzation for 7 days against buffer containing 200 mmol/l glucose, or sham-treated without glucose and oxidized by incubation with Cu++. The degree of glycation accounted to 32 +/- 4%, and glycation rendered Lp(a) more susceptible to oxidative modification when exposed to Cu++. Isolated rings of rabbit aorta were superfused with physiological salt solution, and isometric tension was recorded. Incubation of the aortic rings with sham-treated or with 30 microg/ml glycated Lp(a), not oxidized, had no influence on acetylcholine-induced, endothelium-dependent relaxation. Exposure of the aortic rings to 30 microg/ml oxidized non-glycated (ox) Lp(a) caused a significant inhibition (19% at 1 microM acetylcholine) of the endothelium-dependent relaxation. Incubation of aortic rings with 30 microg/ml oxidized glycated (glyc-ox) Lp(a) attenuated endothelium-dependent relaxation more potently than oxLp(a) (by 34% at 1 microM acetylcholine). The presence of diethyl-dithio-carbamate (DDC), an inhibitor of the endogenous superoxide dismutase (SOD), potentiated the inhibition of relaxation induced by oxLp(a) and by glyc-oxLp(a) [38% inhibition at 1 microM acetylcholine for oxLp(a), and 49% inhibition at 1 microM acetylcholine for glyc-oxLp(a)]. Co-incubation with the O2- scavenger 4,5-dihydroxy-1,3-benzene disulfonic acid disodium salt (TIRON) prevented the inhibition of relaxation by the oxidized lipoproteins, suggesting that enhanced NO-inactivation by O2- could be the underlying mechanism for the impairment of endothelium-dependent dilations by ox- and glyc-oxLp(a). The concentration of lysophosphatidycholine, a lipoprotein oxidation product and stimulus for O2- formation, was significantly enhanced in oxLp(a) and in glyc-oxLp(a) compared to native lipoproteins. CONCLUSION: Glycation enhances the endothelium-damaging influence of oxLp(a), presumably by enhancing oxidative stress. The likely mechanism for attenuation of endothelium-dependent dilations is increased formation of O2-, resulting in inactivation of nitric oxide. This mechanism may play an important role in diabetic patients and may contribute to disturbed organ perfusion.
1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗
CD44 is an independent prognostic factor in early-stage cervical cancer.
The expression of specific cell-adhesion molecule CD44 isoforms (splice variants) is associated with metastatic spread and poor prognosis in human malignancies. The aim of this study was to evaluate whether CD44 isoform expression is a prognostic factor in early-stage cervical cancer. We used 4 different variant exon sequence-specific murine monoclonal antibodies to the CD44 isoforms CD44v3, CD44v5, CD44v6 and CD44v7-8 to study the prognostic value of CD44 splice variants in 200 cases of International Federation of Gynecology and Obstetrics (FIGO) stage-IB cervical cancer by immunohistochemistry. In the univariate analysis, the expression of CD44v3 (log-rank test, p = 0.03) and CD44v6 (log-rank test, p = 0.03) was correlated with poor overall survival. In the subgroup of patients without metastatic disease in the pelvic lymph nodes, expression of CD44v6 was correlated with poor disease-free and overall survival (log-rank test, p = 0.04 and p = 0.01, respectively). Multivariate analysis, correcting for the confounding variables pelvic lymph-node involvement, depth of invasion and histologic grading, revealed CD44v6 to be an independent prognostic factor for overall survival of patients with early-stage cervical cancer. The results of this study indicate that CD44v6 is an additional prognostic marker in surgically treated cervical cancer. The assessment of CD44 isoform expression could be of clinical value in deciding upon adjuvant therapy, resulting in a more individualized management of therapy.
Adult↗
[Cardiovascular risk factors in diabetic nephropathy].
BACKGROUND: Diabetic nephropathy is associated with increased cardiovascular mortality. This may be contributed to by changes in plasma lipids, fibrinogen and hemorheology. Cardiovascular autonomic dysfunction, which is related to an increased incidence of arrhythmic death, may also play a role. PATIENTS AND METHODS: Therefore, we investigated in 58 IDDM-patients with none (n = 28), incipient (albuminuria 30 to 300 mg/day, n = 11) and overt clinical nephropathy (albuminuria > 300 mg/day, n = 19) plasma concentrations of lipoproteins and fibrinogen, plasma viscosity, erythrocyte aggregation and erythrocyte rigidity. Assessments of neuropathy included tibial nerve motor conduction velocity, perception of vibration, beat-to-beat variation during rest and during forced respiration, heart-rate response to Valsalva maneuver and heart-rate response to standing (30:15). RESULTS: Patients with clinical overt nephropathy had, compared to those without nephropathy, significantly higher concentrations of LDL-cholesterol, triglycerides and fibrinogen, significantly lower concentrations of HDL-cholesterol and significantly higher plasma viscosity, erythrocyte aggregability and erythrocyte rigidity. Regarding the assessments of neuropathy we found in patients with nephropathy, compared to those without nephropathy, significantly reduced tibial nerve motor conduction velocity, reduced perception of vibration thresholds and reduced heart rate variability during rest, during forced respiration, in response to Valsalva maneuver and in response to standing. In diabetic patients with microalbuminuria erythrocyte aggregability and erythrocyte rigidity were significantly higher and heart rate variability during rest was significantly lower than in patients without nephropathy. CONCLUSION: In clinical overt nephropathy there is an aggregation of different cardiovascular risk factors, namely, disturbances in lipoprotein concentrations, increased fibrinogen concentration and disturbances in hemorheology. Furthermore marked deterioration in peripheral and autonomic cardial nerve function in these patients is evident accounting for a part of the greatly increased cardiovascular mortality of these patients.
Adult↗
Accumulation of lovastatin, but not pravastatin, in the blood of cyclosporine-treated kidney graft patients after multiple doses.
OBJECTIVES: To study pravastatin and lovastatin pharmacokinetic and pharmacodynamic effects and their interactions with cydosporine (INN, ciclosporin) in kidney transplant patients after single and multiple doses. SUBJECTS AND METHODS: The pharmacokinetic and pharmacodynamic effects of administration of 20 mg/day oral pravastatin and lovastatin for 28 days and their interactions with cyclosporine (2 to 6 mg/kg/day) were studied in a double-blind, double-dummy, randomized, parallel-group multicenter trial in 44 stable kidney graft recipients. RESULTS: The median area under the curve [AUC(0-24)] of pravastatin was 249 microg x hr/L (range, 104 to 1026 microg x hr/L) after a single dose (day 1) and 241 microg x hr/L (114 to 969 microg x hr/L) after multiple doses (day 28) and was fivefold higher than values reported in the absence of cyclosporine. The median AUC(0-24) of lovastatin was 243 microg x hr/L (105 to 858 microg x hr/L) on day 1 and 459 microg x hr/L (140 to 1508 microg x hr/L) on day 28. Besides a significant accumulation during the study period (p < 0.001), the lovastatin AUC(0-24) values were twentyfold higher than values reported without cyclosporine. Coadministration of pravastatin or lovastatin did not alter cyclosporine pharmacokinetics. In this study, 20 mg/day doses of both drugs resulted in a significant improvement of the lipid profile and were well tolerated. CONCLUSIONS: In contrast to lovastatin, pravastatin did not accumulate over the study period, which is probably one of the reasons rhabdomyolysis has been reported in lovastatin-treated but not pravastatin-treated transplant patients receiving cyclosporine immunosuppression.
Adult↗
Corticotropin increases the receptor-specific uptake of native low-density lipoprotein (LDL)--but not of oxidized LDL and native or oxidized lipoprotein(a) [Lp(a)]--in HEPG2 cells: no evidence for Lp(a) catabolism via the LDL-receptor.
To understand the interaction of corticotropin (ACTH) and lipid catabolism, we analyzed the influence of ACTH on receptor-mediated lipoprotein uptake and compared the uptake and degradation of human native (N-LDL) and oxidized (Ox-LDL) low-density lipoprotein and native (N-Lp(a)) and oxidized (Ox-Lp(a)) lipoprotein(a) by human hepatoma (HepG2) cells. The receptor affinity of N-LDL, Ox-LDL, N-Lp(a), and Ox-Lp(a) was comparable (Kd, 33, 13, 24, and 13 micrograms/mL medium), whereas the maximum degradative capacity was 10.5-fold higher in N-LDL (Vmax, 1,978 ng/mg cell protein) compared with Ox-LDL (189 ng/mg). In N-LDL, it was 4.5-fold higher than in N-Lp(a) (442 ng/mg) and eightfold higher than in Ox-Lp(a) (246 ng/mg) (P < .05). Addition of ACTH to the cell cultures increased receptor-specific degradation of N-LDL by 44% (2,866 v 1,978 ng/mg, P < .05), whereas changes in Ox-LDL, N-Lp(a), and Ox-Lp(a) showed no significant increase. No differences in uptake specificity were observed with or without ACTH. In addition, a 12-hour preincubation of liver cells with LDL increased Lp(a) uptake by 40% to 50% with (411 v 620 ng/mg) and without (393 v 558 ng/mg) ACTH administration. These data indicate that ACTH elevates receptor-specific uptake of N-LDL, but only to a low extent versus Ox-LDL, N-Lp(a), or Ox-Lp(a). These results support the hypothesis that catabolism of oxidized lipoproteins and Lp(a) through the LDL receptor pathway is only a minor route of lipid metabolism, whereas LDL receptor activity itself can be stimulated by ACTH.
Adrenocorticotropic Hormone↗