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Biomedical subjects

D Scholz

Publications and source records attributed to D Scholz.

At least 109 records · Page 6Linked to original sources

[Saralasin test in the differential diagnosis of essential and renal hypertension].

In a multicentric prospective study should be tested clinically the effectiveness and the tolerance of an angiotensin-II-antagonist (Saralasin-IWF) developed by the Institut für Wirkstofforschung der Akademie der Wissenschaften, its position in the differential-diagnostic step programme of the arterial hypertension should be analysed and with it should be performed pathogenetic investigations for hypertension after kidney transplantation. Taking into consideration international studies our results confirm that the Saralasin test, taking into account strongly standardized methodical prerequisites, is suited to objectify a participation of the RAAS in the hypertension pathogenesis, without, however, thus making an absolutely reliable evidence concerning the etiology of hypertension. The Saralasin test may represent an important diagnostic criterion for an optimization of the therapy of "volume-resistant" hypertension under the conditions of haemodialysis and in connection with selective renin determinations it possesses a high value in the screening diagnostics of the arterial stenosis after allogenic kidney transplantation.

Blood Pressure↗

Prolongation of rat renal allograft survival time by donor pretreatment with 8-methoxypsoralen and longwave ultraviolet irradiation of the graft (PUVA therapy).

Pretreatment of the kidney donor with 8-methoxypsoralen (8-MOP) and ex vivo longwave ultraviolet irradiation (UVA) of the kidney prolonged the subsequent survival on allogeneic recipients. The efficacy of this treatment seems to be dependent on the time and dose of UVA irradiation rather than on the dose of 8-MOP. In conclusion, PUVA treatment is effective in reducing the immunogenicity of the rat kidney allograft, although the mechanism remains unclear. These experimental findings are new and preliminary results in clinical human kidney transplantation are favourable.

Animals↗

Extracorporeal microsurgical repair of injured multiple donor kidney arteries prior to cadaveric allotransplantation.

To prevent the complications of ureteral and parenchymal ischemia it is important to revascularize all accessory and main branches of the renal arteries in kidney transplantation. 11 allografts underwent ex vivo microsurgical repair of injured polar arteries prior to allotransplantation, and 1 patient had an in situ repair. Three extracorporeal reconstructive techniques are used that are applicable to most of the vascular injuries presented by multiple renal arteries. These are simple and effective methods that avoid subjecting the allograft to prolonged warm ischemia. There were no operative complications, and only one late arterial stenosis occurred; five transplants currently are functioning. The 1-year graft survival in this group, which is 50%, does not differ significantly from those of all transplants (58%). As a result of our policy, 10.5% more allografts were utilized.

Cadaver↗

Influence of different culture conditions on BLV expression in permanently infected FLK cell lines.

The permanently BLV-infected FLK cell line 44/2 and FLK sublines were tested for the stability of their BLV and antigen synthesis by three virus markers, p24, gp51, and activity of reverse transcriptase. The extent of BLV production in the FLK line correlated directly with the surface for cell growth in roller and stationary cultures. The synthesis and secretion of non-virus-associated gp51 is especially stimulated in the roller culture, and is largely independent of the quality of the culture medium. The roller culture allows considerable economy of the medium, at the same time retaining its full biological activity. As much as 2 mg of gp51 per litre of culture supernatant was obtained by this procedure. Appropriate markers for estimation of BLV production are p24 and gp51. For this purpose, the activity of reverse transcriptase on its own was not sufficient. The BLV yield differed by one order of magnitude among the 18 cloned FLK sublines. Three sublines have been identified, which showed a comparatively high virus production, under conditions of stationary cultures. The amount or activity of viral markers could not be correlated with the number of BLV proviruses.

Animals↗

[Frequency of infection with cytomegaloviruses (CMV) following kidney transplantation and initial experiences with CMV gamma globulin prevention].

In a retrospective study we investigated 364 patients who had received cadaveric kidney transplants between 1978 and 1984 as to cytomegalovirus (CMV) infections using complement-fixation test and indirect immunofluorescent test (IgM, IgG). Before transplantation, 194/364 patients were seropositive and 170/364 were seronegative. After transplantation, seroconversion or an increase in titre (greater than or equal to 4 fold) was found in 26% of seropositive recipients and in 30% of seronegative recipients. In contrast to the secondary infections (approximately 40% asymptomatic or oligosymptomatic), the primary infections were regularly connected with a clinical symptomatology. As to the recipient's and donor's pre-transplant antibody status the highest infection rate (62%) was seen in the group of seronegative recipients of kidneys from seropositive donors. Preformed CMV antibodies seem to be useful in preventing severe CMV-diseases. Therefore, in April 1985 we started a randomized study in order to investigate the efficacy of an i.v. cytomegalovirus-immunoglobulin (CMV-Polyglobin/Cutter). There were no side effects. Already 4 h after infusion we were able to detect CMV-IgG-antibodies (IFT) in peripheral blood. This passive immunization, however, was not capable to prevent a CMV infection in each case; there were 5/8 seroconversions and 4/8 symptomatic CMV infections. Nevertheless, we think the application of CMV immunoglobulin has a beneficial effect.

Antibodies, Viral↗

[Blood level oriented ambulatory cyclosporin A therapy following kidney transplantation].

It is reported on the blood level-oriented oral long-term therapy with cyclosporin-A (Sandimmun) in 20 patients after kidney transplantation. The Cy-A-concentrations were measured in the whole blood by means of a radioimmunoassay (Sandoz) under steady state conditions. The mathematical analysis of the steady state daily minimum concentrations in the whole blood depending upon the dosage rate allows individual calculations of the dosage for the stabilisation of the therapeutic concentration desirable for the individual patient in each case. In the majority of the patients a non-linear relation between the steady state blood concentration and the dosage rate was present. The observation of a defined therapeutic area under the conditions of the ambulatory treatment could be achieved without any problems. The control intervals were 4-6 weeks. The long-term stability of the individual pharmacokinetic parameters can at present not be judged reliably, since the average observation time is still too short. In 6 patients who are controlled on the way demonstrated already for several months no systemic changes in the behaviour of the blood level were to be seen.

Cyclosporins↗

Increased serum gamma-glutamyltransferase activity in renal transplant recipients: liver damage or microsomal enzyme induction?

To investigate the reason for the increased activities of gamma-glutamyltransferase in the serum of renal transplant recipients, the activity of this enzyme was determined together with the alanine aminotransferase and alkaline phosphatase activity in serum (as an index of liver damage) and the urinary excretion of D-glucaric acid (as an index of microsomal enzyme induction) in 63 renal transplant recipients. Forty-one patients had increased activities of gamma-glutamyltransferase. Increased D-glucaric acid excretion was found only in ten patients having elevated alanine aminotransferase and/or alkaline phosphatase in seven cases and gamma-glutamyltransferase in eight cases. Therefore, the increased gamma-glutamyltransferase activities in renal transplant recipients can be primarily considered as a consequence of hepatobiliary dysfunction and not of enzyme induction.

Alanine Transaminase↗

Basal plasma somatostatin in biliary stone patients.

We have searched for elevated basal plasma somatostatin in patients with documented cholelithiasis (n = 37) and compared the data with healthy control subjects (n = 27). Using an acidic assay system for measuring somatostatin in unprocessed plasma, we could not find deviations from normal values in biliary stone patients. Also basal blood levels of other islet cell hormones (insulin, glucagon) and minerals (calcium, magnesium) are unchanged. Further studies are needed to find out whether an abnormal response of plasma somatostatin to appropriate stimuli can play a role in the etiology of biliary stones.

Adult↗

Postprandial hyperoxaluria and intestinal oxalate absorption in idiopathic renal stone disease.

Calcium and oxalate were studied in daily, fasting and postprandial urine specimens from healthy subjects and patients with idiopathic renal calcium stones in response to a test meal free of oxalate, and supplemented with calcium and 14carbon-oxalic acid. The data showed that the amount of oxalate in fasting urine of patients with stones did not differ from that in controls. Generally, patients with stones had considerable postprandial hyperoxaluria in terms of excretion and concentration, associated with a significantly higher degree of supersaturation with regard to calcium oxalate compared to controls. These findings were paralleled by decreased intestinal absorption of 14carbon-oxalate and by unchanged 24-hour urinary oxalate. Although the source of increased postprandial oxalate in patients with stones is not clear the possibility of enhanced de novo synthesis from oxalate precursors is discussed. In patients with different types of calciuria the 2 main risk factors (hyperoxaluria and hypercalciuria) for the process of stone formation are recognizable more readily in the postprandial urine specimens than in fasting or daily urine specimens.

Adult↗

Multiple forms of alanine aminopeptidase, alkaline phosphatase and gamma-glutamyltransferase in urine of healthy persons, patients suffering from kidney diseases and patients with kidney transplants.

The catalytic activities of alanine aminopeptidase, alkaline phosphatase and gamma-glutamyltransferase were determined in the soluble and particulate fractions of urine, after ultracentrifugation. In healthy adults the fractional catalytic activities in the supernatants were 0.53, 0.56 and 0.24, respectively. Nearly the same proportions were found in children. In patients suffering from chronic kidney diseases there was a tendency for the proportion of catalytic activity in the soluble fraction to increase. However, the separation into the multiple forms gave no higher diagnostic reliability than the determination of total catalytic activity of the respective enzymes. The determination of multiple forms has no clinical significance in the detection of rejection episodes in renal transplant recipients.

Adult↗

[Fc IgG carrying T lymphocytes in healthy adults and patients following kidney transplantation].

In 28 healthy adults aged 19 to 52 years, normal values of the TG lymphocytes amount to 17.8 +/- 2.3% and 253.1 +/- 96.1 per microliters respectively and the non TG/TG ratio to 4.72 +/- 0.82. When compared with normal controls, patients on dialysis had a disturbed non TG/TG ratio (4.72 +/- 0.82 vs. 6.00 +/- 1.94, p less than 0.05). During the first posttransplant month the total TG cell count was significantly reduced, but the relative TG cell count did not significantly differ from the normal as well as praeoperative TG cell count. In connection with rejection crises we could not observe any changes in the TG subset. Beside this general dynamics we observed two different kinds of changes of the non TG/TG ratio in the individual posttransplant course. Either the non TG/TG ratio were lower than praetransplant or higher. In 9 out of 9 cases the lowering of the non TG/TG ratio (that means a relative or absolute increase of Fc-IgG receptor bearing T cells) were connected with a good graft function. In 4 out of 6 cases a postoperative increase of the non TG/TG ratio were connected with an early graft failure. A change of T subsets for the benefit of TG cells which includes suppressor cells seems to be favourable with regard to the graft survival. Therefore, we think the determination of the prae- and posttransplant non TG/TG ratio is of some prognostic value.

Adult↗

[Anti-Thomsen-Friedenreich (anti-T) antibody titer in kidney transplant recipients].

In 43 recipients of allogenic cadaver kidneys before and three times a week after transplantation to the discharge from the hospital care the antibody titre against the Thomsen-Friedenreich-antigen (Anti-T) was determined and the score value was calculated from the agglutination intensity. A prognostic significance of the value got before operation could not be found. No changes of the titre appeared under the influence of the postoperatively performed immunosuppression as well as in connection with rejection crises. In 9 patients with clinically manifest systemic infections (8 cytomegalovirus infections, 1 bacterial infection) unequivocal (greater than or equal to 8 fold) increases of the anti-T-titre could be proved. These findings speak for an infection-induced formation of these cross-reacting anti-T-antibodies.

Adolescent↗

[Urinary enzyme excretion in kidney transplant patients].

In a survey the present state of the activity determination of urinary enzymes after kidney transplantation as a diagnostic tool in the control of patients with transplanted kidney is described. A great number of enzymes has up to now been established in these patients. The most extensive data are present for the enzymes alanine-aminopeptidase, N-acetyl-beta-D-glucosaminidase and lysozyme. After the transplantation of the kidney typical excretion patterns of the enzymes in the urine are observed in immediate function, retarded onset of the function, without function and acute rejection of the graft. Particularly the behaviour of the urinary enzyme excretion during acute rejection reactions can be diagnostically used. Hereby, the diagnostic reliability of determinations of the activity of urinary enzymes is, however, differently assessed by various authors. In future works in close cooperation between clinic and laboratory the diagnostic validity of the determinations shall unambiguously be characterized and the determinations of the enzyme activity in the urine should be summarized together with other parameters to an optimum combination of parameters for the follow-up investigation of patients who underwent kidney transplantation.

Acetylglucosaminidase↗