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Biomedical subjects

H Graf

Publications and source records attributed to H Graf.

At least 109 records · Page 6Linked to original sources
PubMed1989

Percutaneous transluminal angioplasty of failing arteriovenous dialysis fistulae.

Percutaneous transluminal angioplasty (PTA), a method combining diagnostic and therapeutic procedures, was studied prospectively in 40 patients with clinically failing a-v fistulae. Forty-seven procedures were performed in 40 patients with a variety of a-v fistulae (26 Cimino, five saphenous loops, five goretex grafts, and four upper-arm fistulae). In 43 cases the procedure was initially successful. The mean time of fistula patency after first PTA was 10.06 +/- 2.10 months. Primary failures were due either to technical inability to pass the stenosis (two patients) or to vessel perforation during the attempt (two patients). Surgical intervention had to follow both perforations. Restenosis at the dilatation site occurred in six patients, and in one a new stenosis at a different site occurred; the mean time of fistula patency in these patients was 5.8 months. Our results suggest that PTA is a highly effective therapy for the majority of cases of shunt stenosis. The success rate of the method is excellent and the complication rate low. The combination of this interventional approach with the mandatory angiographic procedure if stenosis of a fistula is suspected makes PTA a favourable first-line treatment and appears to save a considerable number of surgical interventions.

Adult↗
PubMed1989

[Follow-up examination of maxillary orthopedically treated patients from functional aspects].

In order to check the efficiency of orthodontic therapy a clinical examination and model analysis were done in patients in a two-year-interval. The individuals were a part of different longitudinal group --patients after treatment with removable appliances, --patients after premolar extraction, --control group. The results show that functional disturbances can be observed earlier and more frequently in patients after extraction therapy. With advancing years the difference of functional disturbances between the groups becomes smaller.

Adolescent↗
PubMed1989

[Maxillary orthopedic intervention in an adult].

Dependent on psychological and physiological advantages of an orthodontic therapy with removable appliances in an early stage of dentition, difficulties, spezifities and disadvantages of orthodontic treatment in adults are represented. Possibilities of an useful engagement will be suggested.

Adult↗
PubMed1989

[Methodologic recommendations for the determination of 25-OH vitamin D3 in plasma using HPLC].

A method for measuring 25-OH D3-vitamin (calcidiol) in plasma samples of cattle is described. The samples were purified using non-polar C 18-cartridges and 25-OH D3 was determined by high-performance liquid chromatography (HPLC) on a silicic acid straight phase liquid chromatography column (retention time 11.5 min). The detection limit for 25-OH D3 is about 0.5 ng injection quantity, the average recovery was 90%, the standard error amounted to 8%.

Animals↗
PubMed1988

[Ethylene oxide-induced antibodies and hypersensitivity reactions in hemodialysis].

The presence of antibodies against ethylene oxide, which is used for sterilization of dialyzers, was evaluated in 52 hemodialysis patients (30 male, 22 female). The aim of the prospective study was to evaluate a possible correlation of these antibodies with hypersensitivity reactions during hemodialysis. By means of a radio-allergo-sorbent-test (RAST) only 3.9% (2 patients) were detected to have ethylene oxide antibodies. There was no significant correlation between antibodies on the one hand, and symptoms, eosinophilia and IgE-elevation on the other hand. We could not find ETO-induced hypersensitivity reactions in our study population. Thorough rinsing and sufficient storage time of the dialyzers might be the reasons for these findings.

Adult↗
PubMed1988

[Results of chronic hemodialysis treatment in patients with diabetic nephropathy].

In order to evaluate the differences in morbidity and mortality of diabetics on haemodialysis (HD), data on 12 patients with diabetic nephropathy and 14 non-diabetic patients have been analyzed retrospectively since 1982. The groups were matched for sex, age and duration of HD. We analyzed the differences in survival rate, the number of hospitalization days and the causes of death. Values of BUN, creatinine, calcium, phosphate, cholesterol and triglycerides, alkaline phosphatase, erythrocyte count and haemoglobin were compared throughout the dialysis period. No significant differences occurred between the two groups as regards blood chemistry values (except for creatinine) throughout the observation period. The number of hospitalization days per month of dialysis was significantly different: 1.8 days in diabetic versus 0.9 days in non-diabetic patients (p less than 0.005). This difference is due to a higher rate of vascular access complications and infections. The 3-year survival rate on HD was 73% in type I diabetics (controls 93%), while none of the type II diabetics survived for more than 24 months on HD. The most common causes of death in the diabetic patients were cardiovascular (44%) and septic (44%) complications, followed by cerebrovascular problems (12%). We conclude from our study that the reason for the poor prognosis of diabetic patients on HD is not lack of efficiency of the procedure, but progression of the multisystemic diabetic condition.

Adult↗
PubMed1988

Working capacity is increased following recombinant human erythropoietin treatment.

To investigate the effect of partial correction of anemia in patients maintained by chronic intermittent hemodialysis on aerobic and anaerobic working capacity, eight patients underwent a bicycle spiro-ergometry before and after treatment with recombinant human erythropoietin (r-HuEPO). the initial mean (+/- SD) hemoglobin value was 5.9 mg/dl +/- 0.61 and increased during treatment to 10.9 +/- 0.59 mg/dl, P less than 0.0001). This partial correction of anemia resulted in a significant increase of both oxygen uptake at the anaerobic threshold and peak peripheral oxygen uptake at subjective exhaustion (P less than 0.01 and P less than 0.0002, respectively). The increase in oxygen uptake corresponded to significant increases in Watts, both at the anaerobic threshold and at maximum workload (P less than 0.02 and P less than 0.0004). These data show that partial correction of renal anemia results in a significant increase of both exercise capacity and maximum work.

Adult↗
PubMed1988

Cytomegalovirus infection after kidney transplantation using cyclosporin A and low-dose prednisolone immunosuppression.

The incidence and clinical relevance of cytomegalovirus (CMV) infection has been investigated in 120 consecutive renal allograft recipients receiving cyclosporin A and low-dose steroid (CsA/LDS) immunosuppression. Forty patients (33.3%) showed serological evidence of recent CMV infection; 21 patients (17%) developed clinically symptomatic infection. A seronegative recipient status and an aggressive additional immunosuppressive therapy were significant risk factors for the development of serological infection. There was, however, no difference with regard to these or any other relevant parameters (HLA matching; pretransplant history) between the symptomatic and asymptomatic group. Furthermore there was no influence of CMV infection, whether symptomatic or not, on graft outcome. During the study CMV infection prophylaxis consisted of single-shot CMV hyperimmunoglobulin in 72 patients immediately before grafting, recombinant interferon alpha 2 in 28 patients, and placebo in 20 patients. There was no beneficial effect of either interferon or hyperimmunoglobulin on the incidence and severity of CMV infection. However, steroid-resistant vascular rejections were much more common in the interferon group. We conclude that the incidence of CMV infection after kidney transplantation using CsA/LDS immunosuppression is lower when compared to kidney grafting with conventional immunosuppression. Prophylactic treatment with single-shot hyperimmunoglobulin is not effective, and recombinant interferon alpha 2 prophylaxis may even exert deleterious effects on graft survival by inducing steroid-resistant vascular rejection.

Adult↗
PubMed1988

Adverse effect of low-dose prophylactic human recombinant leukocyte interferon-alpha treatment in renal transplant recipients. Cytomegalovirus infection prophylaxis leading to an increased incidence of irreversible rejections.

Since infections with Herpetoviridae after kidney transplantation still remain a major clinical problem, we conducted a double-blind, placebo-controlled trial using low-dose recombinant interferon-alpha-2C (rIFNa2C) prophylaxis in 50 renal graft recipients immunosuppressed with cyclosporine and methylprednisolone. Ten patients were excluded from further analysis because of graft loss due to surgical complications, side effects of rIFNa2C, and because of lack of compliance. There was a significant difference in graft loss due to irreversible rejections between the verum and the placebo group (6 vs. 0; P less than 0.05), whereas no difference was observed with regard to the occurrence of viral infections. We conclude, that low-dose rIFNa2C prophylaxis is harmful in renal allograft recipients treated with cyclosporine in view of the high incidence of irreversible transplant rejections without beneficial effects on the occurrence of viral infections.

Adult↗
PubMed1988

Beta-2-microglobulin in hemodialysis patients. Effects of different dialyzers and different dialysis procedures.

beta 2-Microglobulin (beta 2m) has been identified as the major constituent of dialysis-related amyloid. Although there is no clear correlation between absolute beta 2m levels and amyloidosis-related symptoms, elevated serum levels are thought to be the basis for tissue deposition of beta 2m. Besides diminished renal excretion and insufficient removal during hemodialysis, a dialysis-related induction of beta 2m production is discussed as the major cause of elevated serum beta 2m levels. In order to evaluate the influence of hemodialysis membranes and the hemodialysis procedure on beta 2m levels we determined serum beta 2m levels in patients on chronic intermittent hemodialysis. Polymethylmethacrylate 2.0 m2, cuprophane and cellulose acetate dialyzers led to increasing beta 2m levels during dialysis, which was in excess of what could be accounted for by hemoconcentration. The polymethylmethacrylate 1.6 m2 dialyzer did not result in a significant rise of beta 2m levels during dialysis. This indicates that production of beta 2m is not only dependent on the membrane material but also on the surface area of the dialyzer. The use of polysulfone and hemophane low-flux dialyzers did not induce an increase in beta 2m levels during dialysis but a significant clearance of beta 2m was not demonstrable either. Volume-controlled dialysis with high-flux membranes (polysulfone 0.65 m2 and polysulfone 1.25 m2) lowered beta 2m; clearance values, however, were significantly higher when these dialyzers were used in a hemodiafiltration procedure. We conclude from our study that some dialysis membranes appear to induce beta 2m production, whereas others do not.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellulose↗
PubMed1987

[Effectiveness of recombinant human erythropoietin in the treatment of transfusion-dependent anemia in patients on chronic dialysis].

Recombinant human erythropoietin (r-HuEPO) has recently become available for clinical trial and has been used for the first time in Austria for the treatment of transfusion dependent patients on chronic haemodialysis. Inclusion criteria into the study were baseline haemoglobin levels of less than or equal to 6 g/dl and transfusion requirements of greater than or equal to 1 unit of blood per month. r-HuEPO (CILAG/AMGEN/ORTHO) was administered intravenously 3 times weekly at the end of dialysis. The initial dose was 100 U/kg body weight at each administration and was increased by 25 U/kg if Hb levels failed to increase by greater than 5% of baseline at intervals of 3 weeks. All 9 patients studied showed an increase in Hb values to the desired value at least greater than or equal to 10 g/dl within 6 to 16 weeks and none of the patients required further blood transfusions. All patients reported subjective improvement of life quality and markedly increased working ability. Apart from minor episodes of bone pain and subfebrile temperatures after r-HuEPO administration no major side effects were noted. These preliminary results show that r-HuEPO (CILAG/AMGEN/ORTHO) is a safe and effective form of therapy for renal anaemia and one which opens new horizons in the management of patients on chronic haemodialysis.

Anemia↗
PubMed1987

[Utilization of 15N-labeled urea in laying hens. 8. 15N-incorporation in the amino acids of the oviduct].

3 colostomized laying hybrids received orally with a conventional ration 1% urea with 96.06 atom-% 15N excess (15N'). over a period of 6 days. In the period of the experiment every hen consumed 2.87 g 15N'. After another 2 days, on which they received conventional feed urea, the animals were butchered. 15N' was determined in the total N and in 15 amino acids of the oviduct. Of the 15 amino acids the labelling of glutamic acid, glycine and serine was highest and on average amounted to 0.80, 0.66 and 0.67 atom-% 15N'. In lysine and arginine only 0.10 and 0.11 atom-% 15N' could be detected. The amino acid N with natural isotopic frequency amounted to a quarter for the basic amino acids, a tenth for the branched chain ones and for the non-essential ones (glutamic acid, aspartic acid, serine, glycine, alanine, proline) a third of the total oviduct 14N, The average quota of 15N' is only 3.6%, that of the branched chain amino acids 4.5 and that of the non-essential ones 21.1%. Consequently, the 15N' of the urea is mainly used for the synthesis of the non-essential amino acids of the oviduct.

Amino Acids↗
PubMed1987

Pathophysiology of type A hypoxic lactic acidosis in dogs.

Hypoxic lactic acidosis (HLA) was induced in dogs by ventilating them with a hypoxic gas mixture of 8% O2-92% N2. The animals were studied both in the control state and after development of HLA, where arterial lactate was above 5 mM, pH was below 7.2, bicarbonate was below 12 mM, and arterial PO2 was between 26 and 30 Torr. After hypoxia had been present for 90 min, most of the increase in arterial lactate vs. control was due to increased lactate production from gut and carcass in the presence of a decreased capacity of the liver to extract lactate. The capacity of the liver to extract lactate in the normoxic state was evaluated in another group of six dogs after infusion of L-lactic acid such that arterial pH, lactate, and bicarbonate were similar to hypoxic values. In these experiments it was found that the capacity of the liver to extract lactate was 14.8 +/- 1.7% of the delivered load vs. 4.9 +/- 1.3% observed in hypoxic animals. The decreased liver lactate extraction in HLA was probably secondary to both a decrease in liver oxygen uptake and a decrease in liver intracellular pH and was paralleled by an increase in liver tissue lactate levels. Cardiac output, in contrast to other forms of lactic acidosis, was increased by 40% vs. control and femoral artery flow by 35%, whereas liver blood flow was unchanged and renal blood flow decreased. Hypoxic lactic acidosis thus is the consequence of overproduction of lactate by both gut and carcass, in the presence of impaired utilization of lactate by the liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1987

Determination of thiocyanate in plasma and saliva without deproteinisation and its validation as a smoking parameter.

A simple photometric procedure was developed for the determination of thiocyanate (SCN-) in plasma and saliva without deproteinisation or dialysis. Fe(III) ions form a red coloured complex with SCN- with a maximum absorbance at 460 nm. Mercury(II) nitrate is used to run a sample blank. A manual and an automated version (COBAS BIO) of the method is described. The method is linear up to 5000 mumol/l SCN-. The CV of the between-run precision is 2.8-8% for the manual and 2.6-6.6% for the automated method. The SCN- plasma concentration was 21-134 mumol/l in nonsmokers and 44-260 mumol/l in smokers. In mixed saliva, the concentration is much higher than in plasma: 1.57-5.5 mumol/l in smokers and 0.79-3.9 mumol/l in nonsmokers. Plasma, but not oral fluid SCN-, is a valuable parameter for studying smoking habits in population surveys. However, its use is limited. In our experience only heavy smokers can be distinguished from nonsmokers.

Female↗