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Biomedical subjects

T Risler

Publications and source records attributed to T Risler.

At least 91 records · Page 5Linked to original sources
PubMed1992

Noninvasive procedures for diagnosis of renovascular hypertension in renal transplant recipients--a prospective analysis.

The purpose of this study was to clarify the selectivity and specificity of noninvasive procedures for diagnosis of clinically suspected posttransplant renovascular hypertension. We prospectively investigated 25 renal transplant recipients with arterial hypertension and clinically suspected stenosis of the graft artery (8 female and 17 male patients; ages 45 +/- 15 years). We performed a captopril test with 25 mg captopril (n = 25), renography with technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) before and after angiotensin-converting enzyme (ACE) inhibition with determination of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) (n = 23) and color-coded duplex ultrasonography of the transplant kidney vessels (n = 24). Renal transplant artery stenosis (RTAS) was excluded by renal arteriography in 20 patients and by operative evaluation or clinical follow-up in 5 patients. We identified 4 patients with RTAS and renovascular hypertension. The noninvasive methods showed the following results (sensitivity/specificity): (1) captopril test: 75%/67%; (2) renography combined with ACE-inhibition: 75%/84%; and (3) color-coded duplex ultrasonography: 100%/75%. We conclude that in patients with clinical evidence of RTAS most noninvasive diagnostic procedures are not sufficiently accurate to exclude the diagnosis. Only color-coded duplex ultrasonography did not fail to detect all patients with RTAS and may act as a screening test. Intraarterial renal angiography remains the most reliable and as-yet indispensable diagnostic test for transplant recipients to rule out RTAS.

Adult↗
PubMed1992

Human cytomegalovirus in immunoglobulin A nephropathy: detection by polymerase chain reaction.

Human cytomegalovirus (HCMV) has been suspected to participate in the pathogenesis of IgA nephropathy (IgAN). However, with regard to the presence of HCMV in the renal tissue of IgAN, conflicting results have been reported using a variety of different techniques. Renal biopsies of 29 patients with IgAN, of 7 with focal segmental glomerulosclerosis (FSGS) and of 11 normal kidneys were analyzed for the presence of HCMV-DNA using the polymerase chain reaction. HCMV-DNA was detected by hybridization with digoxigenin-labelled probes in 14 of 19 analyzed frozen renal biopsies from patients with IgAN. However, only 1 of 17 renal biopsies of IgAN embedded in paraffin was positive for HCMV-DNA. Furthermore, HCMV-DNA was detected in 4 of 18 frozen normal kidneys but in none of the tissues from patients with FSGS. The present results provide further evidence of an association between the presence of HCMV in renal tissue and IgAN.

Adult↗
PubMed1992

Human cytomegalovirus in rejected kidney grafts; detection by polymerase chain reaction.

Human cytomegalovirus (CMV) infections are frequently associated with graft rejection in the immunosuppressed patients following organ transplantation. Thirty-four tissue samples from rejected kidneys and 18 samples from normal adult kidneys obtained from autopsies were investigated for the presence of CMV-DNA by the polymerase chain reaction (PCR) and by immunohistochemistry. DNA extracted from renal tissues after proteinase K digestion was specifically amplified in 32 cycles using primers which flank a 147 bp DNA fragment of the immediate early CMV gene and analysed by slot-blot hybridization with digoxigenin-labelled detection oligonucleotides. CMV-DNA was detected by PCR in a range from 0.1 fg up to 100 fg in 14 (41%) rejected kidney transplants. Comparative immunohistological analysis revealed presence of CMV in only three biopsies of these rejected kidneys. Furthermore, CMV-DNA was also found in four of 18 (22%) normal donor kidneys. These results reveal that CMV is often present in rejected kidneys and that the infection can be transferred from the donor to the recipient, since the normal adult kidney appears to be a frequent site of latency for CMV. No differences in local immunological changes, characterized by interstitial mononuclear leukocyte infiltration as well as by aberrant expression of HLA-class II antigens and of ICAM1 on proximal tubular epithelial cells, could be detected by further immunohistological analysis between grafted kidneys at late stage of rejection with and without CMV infection.

Adolescent↗
PubMed1992

In vivo clearance and elimination of nine marker substances during hemofiltration with different membranes.

The handling of low, middle and high molecular weight markers was examined in seven stable dialysis patients during hemofiltration with different membranes. Four membranes were examined in a randomized, crossover order (polysulfone, polyamide, AN69 polyacrylonitrile, Asahi polyacrylonitrile) by measuring plasma and dialysate concentrations of phosphate, creatinine, vitamin B12, beta 2-microglobulin, furanic acid, hippuric acid, retinol-binding protein, alpha-1-antitrypsin, and albumin. Sieving coefficients and plasma clearances of beta 2-microglobulin or retinol-binding protein were markedly or slightly lower during hemofiltration with the Asahi polyacrylonitrile membrane than with the other membranes (highest removal with polysulfone/AN69 polyacrylonitrile membranes). No differences of obvious clinical relevance could be seen between the four membranes. A high beta 2-microglobulin removal rate might be important to prevent dialysis-associated amyloidosis.

Aged↗
PubMed1991

Simplified, rapid and inexpensive extraction procedure for a high-performance liquid chromatographic method for determination of disopyramide and its main metabolite mono-N-dealkylated disopyramide in serum.

A simplified, rapid and inexpensive extraction procedure for the determination of the antiarrhythmic drug disopyramide and its main metabolite mono-N-desalkylated disopyramide in serum by high-performance liquid chromatography has been developed. The analysis uses ultraviolet detection at 254 nm, and a 5 micron reversed-phase column with a mobile phase of water-triethylamine-acetonitrile-PIC-B8 reagent. Serum extraction is performed with dichloromethane and 1 M sodium hydroxide. p-Chlorodisopyramide is used as internal standard. Recovery rates were 94.5% (S.D. 5.7%) for disopyramide, 96.8% (S.D. 2.2%) for mono-N-desalkylated disopyramide and 97.9% (S.D. 2.8%) for the internal standard.

Chromatography, High Pressure Liquid↗
PubMed1991

Application of a new LDL apheresis system using two dextran sulfate cellulose columns in combination with an automatic column-regenerating unit and a blood cell separator.

Extracorporeal procedures for selective removal of low-density lipoproteins have become a promising new approach for treatment of severe familial hypercholesterolemia. We tested efficacy and safety of a new LDL apheresis system by using two dextran sulfate cellulose adsorbents (Liposorber LA 15TM from Kanegafuchi) under the control of an automatic column-regenerating unit for continuous alternate adsorption and desorption. Plasma was taken from a continuous-flow blood cell separator (model IBM/Cobe 2997) allowing an extracorporeal circuit from one cubital vein to another. A 57-year-old male with drug-resistant heterozygous familial hypercholesterolemia accompanied by moderate hypertriglyceridemia and severe coronary artery disease has been treated every 2 weeks for 3 months so far. Treatment of 4-5 liters of plasma resulted in a mean decrease of total cholesterol from 355 to 111 mg/dl (9.20 to 2.88 mmol/l), of LDL cholesterol from 272 to 49 mg/dl (7.05 to 1.53 mmol/l), and of apolipoprotein B from 175 to 44 mg/dl. HDL cholesterol, apolipoprotein A-I, and other plasma proteins did not substantially change apart from hemodilution. No side effects were seen. This new technique of LDL apheresis represents a very effective and safe method for treatment of drug-resistant familial hypercholesterolemia without or with concomitant hypertriglyceridemia.

Adsorption↗
PubMed1991

Pharmacokinetic profile and tolerability of pimobendan in patients with terminal renal insufficiency.

The pharmacokinetics of an i.v. bolus of pimobendan (P) 2.5 mg and 5.0 mg, its tolerability and the effect on heart rate and blood pressure have been studied in 12 subjects (42-70 y) suffering from severe terminal renal impairment. Plasma level data were compared with those obtained in a previous investigation in healthy volunteers. Pharmacokinetics were dose linear and were comparable to those in healthy subjects. No adjustment of the dose of P is necessary in patients with severe renal impairment. Tolerability of P, observed by means of blood pressure monitoring, clinical chemistry tests, electrocardiography and subjective judgement resulted in 4 complaints out of 12 patients: three suffered from orthostatic problems and vomiting, and one patient had nausea. Mean heart rate was elevated by 19% (2.5 mg) and 16% (5.0 mg). Blood pressure was significantly reduced after 2.5 mg P (23% systolic and 26% diastolic pressure), and after 5.0 mg P by 25% systolic and 23% diastolic pressure.

Adult↗
PubMed1991

Randomized comparison of flecainide and cibenzoline in the conversion of atrial fibrillation.

The efficacy of oral cibenzoline (260 mg/day and 320 mg/day) and flecainide (200 mg/day and 300 mg/day) in the conversion of chronic atrial fibrillation to sinus rhythm were compared in 31 patients in a randomized order. If sinus rhythm was not restored on the 5th day of oral treatment with either cibenzoline or flecainide (phase of initial treatment) patients were switched to a second phase of treatment with the drug not given in the first phase after a washout phase of 3 days. Sinus rhythm was restored in 7/28 treatment trials with cibenzoline and in 7/23 treatment trials with flecainide (not significant). Trough levels of cibenzoline and flecainide in the plasma were not significantly different between patients in whom sinus rhythm was restored and patients with persisting atrial fibrillation. In patients successfully converted to sinus rhythm, long-term treatment was instituted with flecainide (n = 6) or cibenzoline (n = 6). Atrial fibrillation developed in 2 patients in each group of patients within 3 months. In all other patients, sinus rhythm was maintained during the follow-up period of 12 months. Non-cardiac side effects were observed in 2 patients during treatment with cibenzoline and flecainide respectively. With flecainide, one patient developed sinus arrest up to 5.6 seconds.

Adult↗
PubMed1991

Mononuclear leukocytes, expression of HLA class II antigens and intercellular adhesion molecule 1 in focal segmental glomerulosclerosis.

Immunophenotyping of infiltrating glomerular and interstitial mononuclear leukocytes performed in renal tissues of 15 patients with focal segmental glomerulosclerosis (FSGS) was compared to 15 normal kidneys in order to investigate a possible role for cell-mediated immunity (CMI) in FSGS. In addition, distribution of HLA class II (-DQ, -DR, -DP and -DY) antigens and of the intercellular adhesion molecule 1 (ICAM-1) as well as the expression of well-defined renal antigens along the human nephron was analyzed. In comparison to normal kidneys, a reduction in HLA class II antigens of ICAM-1 and of renal antigens defined by the monoclonal antibodies TN8-TN10 was observed in sclerotic glomeruli. Furthermore, an increased number of T lymphocytes was found in glomeruli of FSGS with slight predominance of the CD8+ subset. Interstitial inflammation was present in all FSGS cases except 1 with T lymphocytes and monocytes/macrophages constituting the predominant infiltrating cell types. In contrast to the glomerular T cells, the number of interstitial CD4+ cells was greater than the number of CD8+ cells in almost all cases. As a sign of activation, most interstitial inflammatory cells carried HLA class II antigens and some of them also expressed ICAM-1. Proximal tubular epithelial cells often presented an abnormal expression of HLA-DQ and HLA-DP antigens associated with aberrant expression of ICAM-1 and TN8. The number of interstitial mononuclear leukocytes was correlated to serum creatinine levels at the time of renal biopsy. The present results provide further support for the involvement of CMI in the pathogenesis of FSGS.

Adult↗
PubMed1991

The efficacy of diuretics in acute and chronic renal failure. Focus on torasemide.

Loop diuretics in high doses are the drugs of choice in the treatment of both acute renal failure (ARF) and chronic renal failure (CRF). Their pharmacokinetic and pharmacodynamic properties give them a high efficacy, even in severely compromised renal function. The serum elimination half-life and duration of action of most loop diuretics are dependent on the glomerular filtration rate and are therefore prolonged in renal failure. Torasemide, a new high ceiling and long acting loop diuretic, is as potent as furosemide (frusemide) in patients with advanced renal failure. Unlike other loop diuretics, the half-life and duration of action of torasemide are not dependent on renal function and the parent drug does not accumulate in renal failure. The extent of metabolism is clinically negligible. A number of studies have demonstrated the efficacy of furosemide, bumetanide, piretanide and torasemide in patients with ARF and CRF. When compared with the other loop diuretics, torasemide has the following advantages: a longer half-life independent of renal function, no indications of toxic side effects and apparently less influence on calciuresis.

Acute Kidney Injury↗
PubMed1991

Effects of beta-blockade on urinary albumin excretion in normal subjects.

Urinary albumin excretion is a marker of renal damage in diabetic or hypertensive patients and a reduction of albuminuria during beta-blockade has been demonstrated in several studies. In the present study the effects of beta-blockade with drugs known for differences in their impact on renal function (propranolol, atenolol, bopindolol) on albumin excretion in normotensive and normoalbuminuric subjects were investigated. No effect of beta-blockade on albumin excretion was found, despite decreased plasma renin activity, blood pressure and heart rate. It was concluded that studies in healthy controls are not useful to predict the outcome of treatment in microalbuminuric patients. Cross-over studies using different beta-blockers have yet to be done in micro- or macroalbuminuric patients to evaluate the potential for benefit.

Adrenergic beta-Antagonists↗
PubMed1991

[Comparison of lisinopril and captopril in treatment of severe heart failure (NYHA III-IV) in high risk patients. Preliminary results of the trial].

We present preliminary data of a study comparing captopril, a short acting, with lisinopril, a long acting ACE-inhibitor in 8 of 12 projected patients with severe chronic heart failure (NYHA III-IV) and one additional risk factor (e.g. diabetes mellitus, renal failure). The 8 patients were treated in a cross over design for 12 weeks with either drug. While lisinopril improved NYHA-class in all patients, captopril reached this goal in only 3. Renal function was stable in all patients. Captopril influenced hormones (renin, aldosterone, norepinephrine, epinephrine) and microalbuminuria less than lisinopril. The number of adverse reactions was smaller in lisinopril treated patients. These preliminary data demonstrate at least an equal efficacy of lisinopril compared to captopril in high risk patients with severe chronic heart failure.

Angiotensin-Converting Enzyme Inhibitors↗