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Biomedical subjects

K Derfler

Publications and source records attributed to K Derfler.

At least 37 records · Page 2Linked to original sources
PubMed1996

Elevated lipoprotein(a) and increased incidence of restenosis after femoropopliteal PTA. Rationale for the higher risk of recurrence in females?

It has been shown that the incidence of recurrent stenosis following successful percutaneous transluminal coronary angioplasty (PTCA) is correlated with serum Lipoprotein(a) [Lp(a)] levels. The aim of the present study was to examine the influence of Lp(a) on restenosis after primary successful femoropopliteal PTA. One hundred and thirty nine consecutive patients with peripheral arterial occlusive disease (PAOD) and successful femoropopliteal PTA were studied. Follow-up included clinical examination and non-invasive laboratory testing (pulse volume recordings, ankle-brachial arterial pressure measurement) in every patient before and after 1, 3, 6 and 12 months following intervention. Duplex sonography was performed 1 year after PTA. Suspicion of restenosis (> or = 50% diameter reduction) was verified by angiography. Lp(a) was determined using ELISA technique (mg/dl). Twelve months after successful PTA no restenosis was found in 82 patients (59%: group A). The one-year recurrence rate of 41% (group B) was due to significant restenosis in 35 patients (25%) and reocclusion in 22 patients (16%). The corresponding mean values +/- S.E.M. for Lp(a) were as follows: group A, 28 +/- 5.3; group B 59 +/- 11 (P < 0.01). Women showed a higher frequency of recurrences (55%) versus men (30%, P < 0.01) also corresponding with a high Lp(a) level (51.8 +/- 8 versus 32.7 +/- 5; P < 0.05). Furthermore Lp(a) aggravated the well known increased risk for recurrence in multiple stenoses or occlusions of > or = 5 cm in length. There were no significant differences between groups A and B with respect to age, diabetes, hyperlipidaemia, obesity and cigarette smoking. The results support the view that Lp(a) is an independent risk factor for recurrence after PTA in the femoropopliteal area. It might also be a causal basis for the higher incidence of recurrences in female PAOD patients.

Aged↗
PubMed1996

Beneficial effect of renal transplantation on cognitive brain function.

Cognitive brain dysfunction is a common complication of end-stage renal disease. To investigate the cerebral effect of renal transplantation, we studied P300 event-related potentials--an objective marker of cognitive brain function--trailmaking test and Mini-mental state in 15 chronic hemodialysis patients and 45 matched healthy subjects. Before transplantation, patients showed prolonged P300 latency (364 vs. 337 ms, P < 0.01), smaller amplitude (15.2 vs. 19.1 microV) and scored lower (P < 0.05) in trailmaking test and Mini-mental state as compared to healthy subjects. Following renal transplantation (14 months), P300 latency decreased (337 ms, P < 0.01 vs. before) and amplitude increased (17.4 microV, P < 0.05 vs. before), indicating improved cognitive brain function. The trailmaking test and Mini-mental state tended to improve. Following transplantation, P300 findings, trailmaking test and Mini-mental state were not different from healthy subjects. Additional studies following erythropoietin treatment in 6 of the 15 hemodialysis patients revealed decreased (improved) P300 latency (351 vs. 379 ms before, P < 0.05) with further decrease following transplantation (341 ms, P = 0.06). Our findings indicate that cognitive brain dysfunction in hemodialysis patients may be fully reversed by successful renal transplantation.

Adult↗
PubMed1996

Blood rheology after renal transplantation.

Cardiovascular complications seriously affect posttransplant survival in patients after successful renal transplantation. Abnormalities in blood rheology may contribute to these complications. Therefore, we studied the blood rheology before and during a 1-year observation period after grafting in 9 patients by serial measurements of fibrinogen, red cell aggregation, hematocrit, spontaneous platelet aggregation, and plasma viscosity. Prior to grafting, fibrinogen and red cell aggregation were found to be increased in patients on regular hemodialysis as compared with healthy controls, whereas hematocrit and platelet aggregation were markedly reduced. After successful transplantation, the platelet aggregation progressively rose together with the hematocrit, while fibrinogen and red cell aggregation remained abnormally high. Our findings suggest that abnormal blood rheology in patients with chronic renal failure does not improve in response to successful renal transplantation: fibrinogen and red cell aggregation remain abnormally high; further, the overall blood flow properties are supposed to deteriorate due to the postoperative increase in hematocrit and spontaneous platelet aggregation. Adverse rheological conditions thus resulting may contribute to the increased frequency of vascular events observed in transplanted patients.

Adult↗
PubMed1996

Effect of desmopressin substitution during organ procurement on early renal allograft function.

BACKGROUND: As diabetes insipidus in brain-dead organ donors leads to hypovolaemia, hyponatraemia, and hypotension, desmopressin is recommended for treatment of diabetes insipidus. As its effect on early renal allograft function remains unclear, we conducted a study to evaluate the effect of desmopressin on renal-graft survival. METHODS: We report the results of a prospective study in 41 brain-dead organ donors (mean age 45 +/- 12 years) with diabetes insipidus, who were treated either with adequate fluid substitution and bolus application of desmopressin (desmopressin group; n = 22) or with volume substitution along (control group; n = 19). Donors as well as recipients of both groups were well matched with respect to age, sex, dopamine dosage, serum electrolytes, cold ischaemic time, HLA match, number of prior transplantations, and current cytotoxic antibodies. Early renal allograft function was evaluated in 71 recipients (mean age 48 +/- 4 years within 3 days after transplantation. RESULTS: Overall, primary non-function was observed in 26 (36.6%) of 71 recipients. The rate of primary non-function was significantly higher in the desmopressin group compared to the control group (desmopressin group 48.6%; control group 23.5%; P = 0.28). CONCLUSION: The use of desmopressin during organ procurement is associated with a higher rate of primary non-function of renal allografts.

Adolescent↗
PubMed1996

Regression of coronary atherosclerosis and amelioration of renal function during LDL-immunoadsorption therapy in a renal transplant recipient.

Hyperlipoproteinemia is frequently observed in patients after renal transplantation and contributes to cardiovascular morbidity and mortality. In addition, it was recently shown that hypercholesterolemia accelerates the progression of renal disease. In a renal transplant recipient (RTR) with severe coronary heart disease, familial hypercholesterolemia and decreased renal function, immunospecific LDL-apheresis was instituted since dietary restrictions failed to sufficiently improve hyperlipoproteinemia and medication had to be avoided due to drug interactions. Over a period of 36 months 145 LDL-apheresis treatments were performed at weekly intervals. The desorption of 5600 ml plasma volume allowed a mean reduction of total cholesterol by 56.6% (from 256 mg/dl to 110 mg/dl), of LDL-cholesterol by 63.0% (from 163 mg/dl to 58 mg/dl), of Lp(a) by 68.3% (from 34 mg/dl to 11 mg/dl) and of triglycerides by 49.6% (from 332 mg/dl to 163 mg/dl). Although temporarily decreasing during each apheresis session by 9.0%, HDL-cholesterol values increased during the first 9 months of treatment and remained within the normal range (> 45 mg/dl) thereafter. Cyclosporine A blood trough values were decreased by 32% during LDL-apheresis. Symptoms of angina pectoris rapidly improved and disappeared after 8 months of apheresis treatment. Initial coronary angiography exhibited serious three-vessel-disease, without the possibility of bypass grafting. Coronary angiography repeated after two years of therapy showed a regression of the disease. Serum creatinine levels declined during treatment (from 2.7 mg/dl to 1.8 mg/dl) and proteinuria did not increase further. This is the first report to show that long-term LDL-immunoadsorption is a safe and highly effective treatment of severe hyperlipidemia and coronary heart disease in a RTR, resulting in regression of vascular pathology. Moreover, amelioration of hyperlipidemia may have improved transplant function. Multicenter studies are necessary to confirm our results.

Adult↗
PubMed1995

Rapid elimination of a high-titer spontaneous factor V antibody by extracorporeal antibody-based immunoadsorption and immunosuppression.

We report on the rapid elimination of a potent spontaneous factor V antibody of undetermined etiology by extracorporeal immunoadsorption on sepharose-bound polyclonal sheep antibodies to human immunoglobulins (Ig-Therasorb, Baxter) in combination with immunosuppressive treatment. A 68-year-old woman presented with severe hematuria. Severe factor V deficiency (< 1%) caused by an antibody to factor V (26 BU/ml) was found. Extracorporeal immunoadsorption (8.245 +/- 553 ml plasma processed per session) led to an average reduction of the antibody titer by 75% per session. The procedure was well tolerated without any side effects. Hematuria ceased after three immunoadsorptions and complete elimination of the antibody was achieved after seven sessions (day 15), followed by a rapid increase of the factor V activity to normal levels. Treatment with cyclophosphamide and prednisone was started on day 6 and continued for 2 months. The patient remains in remission at 6 months. Extracorporeal immunoadsorption is a highly effective method for eliminating antibodies to factor V (or other clotting factors) in selected cases, i.e., in patients with severe bleeding tendency, high antibody titer, and low probability of a rapid spontaneous remission.

Aged↗
PubMed1995

Elimination of acquired factor VIII antibodies by extracorporal antibody-based immunoadsorption (Ig-Therasorb).

Treatment of potent factor VIII antibodies is a difficult problem. In some cases a reduction of the antibody titer is necessary for effective treatment with human factor VIII concentrates. We describe a new method for extracorporal elimination of factor VIII antibodies (antibody-based immunoadsorption). Blood is drawn from an antecubital vein, citrated, and plasma is separated with a rotating membrane. Plasma passes alternately through one of two columns filled with sepharose-coupled polyclonal sheep antibodies to human immunoglobulins (Ig-Therasorb), whereas the other column is regenerated. Each cycle has a duration of 15 min. Three patients with high titer factor VIII antibodies (one hemophiliac and 2 with spontaneous antibodies; titers 29, 132, and 313 BU/ml, respectively) were treated. The average reduction of the antibody titer was 76.1 +/- 17.2% per session. In each patient 4 sessions were necessary to reduce the antibody titer to < 1 BU/ml. The mean processed plasma volume was 6731 +/- 640 ml and the mean duration of each session 3.9 +/- 0.7 h. Serum IgG, IgA and IgM levels decreased by 75.3 +/- 11.9%, 62.9 +/- 19.1%, and 54.8 +/- 23.8% respectively. The procedure was tolerated without any side effects. Thus, rapid elimination of factor VIII inhibitors can be achieved with antibody-based immunoadsorption, which can be life-saving in some cases. This promising method should be evaluated in a larger number of patients.

Adult↗
PubMed1994

Feasibility and efficacy of intensive insulin therapy in type 1 diabetes mellitus in primary care.

To determine the feasibility and efficacy of structured education in intensive insulin therapy (IIT) in patients with Type 1 diabetes mellitus commonly attended by primary care physicians, a prospective case-control study was carried out in co-operation with 26 general practitioners in rural Alpine region and the diabetes service at the University of Vienna, Medical School, Austria. From 89 rural Type 1 diabetic patients on conventional insulin therapy (CIT), those volunteering for better diabetes care (n = 52) were trained in IIT in the diabetes education centre and subsequently received their outpatient service by their general practitioners, as did those remaining on CIT (n = 37). Patients were matched as case-controls (n = 36 in each therapy group) for metabolic control at baseline (IIT/CIT: HbA1c 8.2 +/- 1.8 vs 8.1 +/- 2.0%, ns), age, duration of diabetes, incidence of retinopathy and nephropathy. Analysing an observation period of > 4.5 years, patients trained in IIT presented with improved metabolic control as compared to those on CIT (Mean HbA1c: IIT, 6.9 +/- 1.0%; CIT, 7.9 +/- 1.3%, p < 0.05, ANOVA). No difference between groups was, however, observed at the end-point of the study in HbA1c (IIT, 7.3 +/- 1.3%; CIT, 7.8 +/- 1.4%; IIT vs CIT, p = 0.14) and in the development of diabetic microangiopathy, frequency of reported severe hypoglycaemic episodes, and increase in body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Hormonal derangements in patients with severe alcohol intoxication.

Controversial results of fluid and electrolyte derangements in patients with moderate alcohol intoxication have been described. However, no information is available about severe alcohol intoxication. We investigated differences of hormonal disorders between alcohol-habituated and alcohol-naive subjects with severe ethanol intoxication. The hormonal derangements and recommendations on therapy of these patients are discussed. Thirty-three patients [10 alcohol-naive (group A) and 23 alcohol-habituated (group B) subjects] with severe alcohol intoxication (blood ethanol > 200 mg/dl) were selected for the study. Electrolytes and osmolarity of serum and urine, blood ethanol, vasopressin, renin, and aldosterone were determined on admission 2, 4, and 6 hr later. Fluid balance was calculated for each hour. All patients received isotonic saline solution according to urine production. Group A: On admission, serum osmolarity was increased (308 mOsmol/kg). Concomitantly, vasopressin level was elevated on admission (9.12 pg/ml). Increased serum osmolarity was correlated with elevated vasopressin levels (r = 0.8211; p < 0.005). Serum electrolytes, renin, and aldosterone values were within normal ranges. Group B: On admission, vasopressin level was significantly decreased (0.9 pg/ml), despite an elevated serum osmolarity (309 mOsmol/kg). Serum osmolarity remained high despite a sufficient fluid substitution. In addition, vasopressin level remained suppressed over the observation period. Aldosterone level was significantly increased on admission (319 ng/ml). Accordingly, serum sodium was increased from 142 to 148 mM/liter, and serum potassium was decreased from 3.9 to 3.4 mM/liter. Response to hyperosmolarity due to severe alcohol intoxication is different in alcohol-naive and alcohol-habituated subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Extracorporeal lipid elimination for treatment of gestational hyperlipidemic pancreatitis.

Gestational hyperlipidemia complicated by pancreatitis during the 24th week of gestation has been successfully managed by long-term extracorporeal elimination of triglyceride-rich lipoproteins. Three modes of treatment (plasma exchange, immunospecific apheresis, and a combination of both treatments) were compared for efficacy as therapy for metabolic derangements, altered blood rheology, and the loss of immunoglobulins. Treatments were performed by means of a peripheral venovenous approach. A combination plasma exchange/apheresis technique was highly effective; the loss of immunoglobulins remained acceptable. Clinical symptoms of pancreatitis subsided within 24 hours of the first treatment. A relapse during the 32nd week of gestation necessitated treatments more frequently than once a week. At the 36th week of gestation, after confirming lung maturity as indicated by a lecithin-sphingomyelin ratio of > 2.0, a cesarean section was performed. A healthy boy was delivered (2470 g; Apgar score, 9/10). This is the first report to show that long-term extracorporeal elimination of lipoproteins is a highly effective treatment of hyperlipidemic gestational pancreatitis.

Adult↗
PubMed1992

Long-term follow-up of renal transplantation in type 1 and type 2 diabetic patients.

This study evaluated the long-term outcome of renal transplantation in type 1 (n = 25) and type 2 (n = 18) diabetic patients. Overall postoperative survival at 1 year was 69% in type 1 diabetes and 75% in type 2; at 5 years it was 62% in type 1 diabetes and 58% in type 2. Death was due mainly to cardiovascular disease (60%) and septic gangrene (20%). Outcome was examined in terms of graft function, which was poor in the majority (86%) of patients who died. Patients with fatal outcome suffered major vascular complications prior to renal transplantation and frequently had impaired graft function. Metabolic control was better in patients with good graft function (HbA1c < 6.2%) than in those with poor or no function of kidney transplant (HbA1c > 9.8%). In the absence of severe vascular complications renal transplantation may be the treatment of choice for both type 1 and type 2 diabetic patients with end-stage renal disease. Otherwise, renal transplantation is not able to improve the prognosis of patients with a history of severe vascular complications prior to renal replacement therapy.

Adult↗
PubMed1992

Renal replacement therapy in type 2 diabetic patients: 10 years' experience.

The objective of this study was to determine the impact of renal transplantation and hemodialysis treatment on outcome of elderly diabetic patients with end-stage renal disease (ESRD) among other factors related to survival. Results of treatment of ESRD in 78 patients with non-insulin-dependent diabetes mellitus (type 2) showed a survival rate of 58% at 1 year and 14% at 5 years, independent of treatment modality. Patients who received a renal allograft had a higher survival rate as compared with patients on hemodialysis treatment (5-year survival, 59% v 2%; P < 0.005). Diabetic patients with a history of myocardial infarction, stroke, or peripheral gangrene before onset of renal replacement therapy had a worse prognosis in comparison to patients without vascular complications (5-year survival, 2% v 21%; P < 0.05). Analysis of patients who survived less than 6 months and more than 24 months was performed. Long-term survivors were slightly younger, had diabetes for a shorter period, and showed a better metabolic control of diabetes mellitus. Sixteen long-term survivors received a renal allograft. In contrast, only three short-term survivors were transplanted. Furthermore, short-term survivors also had a greater than 70% incidence of severe vascular complications before renal replacement therapy. A history of myocardial infarction, stroke, or peripheral gangrene is an independent predictor of decreased survival, irrespective of whether the patients were transplanted or maintained on chronic hemodialysis treatment. In contrast, renal transplantation improved survival of elderly diabetic patients without vascular complications and should be the treatment of choice in this specific group of patients.

Aged↗
PubMed1992

T-cell selection and T-cell receptor variable beta-chain usage in chronic hemodialysis patients.

Thymic and extrathymic selection processes are responsible for the shape of the T-cell repertoire. T-cell receptor (TCR) variable (V) chain usage, holding a place in tolerance, autoimmunity and response to external agents, was analyzed in 41 patients maintained on chronic hemodialysis treatment. Leukocyte (mean: 6444 +/- 2277 cells/microliters), lymphocyte (mean: 1457 +/- 707 cells/microliters) and T-cell (mean: 67 +/- 16%) counts were within expected limits, but hemodialysis patients showed an impressive increase of TCR V beta 6.7 positive peripheral blood lymphocytes (PBL) and a massive deletion of TCR V beta 8 positive PBL. V beta 6.7 positive PBL were detectable in all hemodialysis patients (n = 41, mean: 2.47 +/- 1.61% PBL) in contrast to a healthy population, where only 45% of subjects expressed V beta 6.7 on PBL (n = 9, mean: 3.50 +/- 1.83% PBL). Only 27% of our hemodialysis patients expressed V beta 8 on PBL (n = 11, mean: 1.00 +/- 1.94% PBL) in contrast to healthy subjects, who presented V beta 8 positive PBL (n = 20, mean: 2.89 +/- 1.23% PBL) in every case. Neither primary kidney disease, nor response to vaccination for hepatitis-B, nor dialyzer membranes used, were associated with these alterations of the TCR V beta-pool. It is likely, that the well-known impairment of the cytokine network in chronic renal failure, uremic toxins or response to infectious agents, may contribute to these different and possibly independent T-cell selection mechanisms in uremia.

Cell Separation↗