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Biomedical subjects

P Petritsch

Publications and source records attributed to P Petritsch.

At least 19 recordsLinked to original sources

The determination of metabolite M17 and its meaning for immunosuppressive cyclosporin therapy.

Cyclosporin A (CyA) is intensively metabolized by the hepatic cytochrome p450 III monooxygenase A system in the human liver, the most important metabolites being M1, M17, and M21. Because CyA and its metabolites have nephrotoxic, hepatotoxic, and neurotoxic side effects, CyA dosage must be calculated to avoid the risk of organ rejection through underdosage and toxic organ damage through overdosage or accumulation of metabolites. In this study, we determined the whole-blood concentrations of cyclosporin and metabolite M17 by high-pressure liquid chromatography (HPLC) and by monoclonal specific and polyclonal nonspecific fluorescence polarization immunoassay (Abbott) in patients after immunosuppressive treatment. Patients with different resorption and metabolization rates showed high individual variations. CyA concentrations in patients with good liver function and low concentrations of CyA metabolites showed a good correlation between the HPLC and the FPIA (TDx-monoclonal assay) methods in ranges between 25 and 180 ng/mL. TDx-monoclonal was not always as precise as HPLC. In cases of metabolic disorders, we found false high CyA concentrations assayed with the immunologic method, caused by a crossreaction of the elevated metabolite concentration. We found that HPLC rendered more information about the extent of immunosuppressive activity and the metabolization rate and showed a good correlation with the concentration of metabolite M17 and total metabolites measured with the Abbott CyA polyclonal kit.

Antibodies↗

Functional magnetic resonance imaging of human renal allografts during the post-transplant period: preliminary observations.

Graft dysfunction is a common occurrence during the first weeks following renal transplantation. The current study was designed to evaluate the potential of renal magnetic resonance (MR) perfusion imaging to differentiate acute allograft rejection (AAR) from acute tubular necrosis (ATN) during the post-transplant period. Twenty-three consecutive patients with clinically suspected ATN and/or AAR and eight consecutive control patients (asymptomatic, serum creatinine concentration < 1.5 mg/dL) underwent MR perfusion imaging of the renal allograft within 64 days after transplantation. Histopathology was obtained in all cases with clinical suspicion of ATN or AAR. Sixty sequential fast gradient-recalled-echo MR images were acquired in each patient after intravenous administration of gadolinium-DTPA (0.1 mmol/kg). Histopathology revealed 6 patients with pure AAR, 4 patients with a combination of AAR and ATN, 12 patients with ATN and 1 patient with normal findings. Kidney graft recipients with normal renal function showed a moderate increase in signal intensity (SI) of the renal cortex and medulla after administration of contrast agent followed by an immediate and short decrease in SI of the medulla (biphasic medullary enhancement pattern). The increase in cortical SI of patients with AAR was significantly smaller (61 +/- 4% increase above baseline) than that measured in normal allografts (136 +/- 9% increase above baseline) (p < 0.05) and patients with ATN (129 +/- 3% increase above baseline) (p < .05). Patients with ATN had a slightly delayed and diminished cortical enhancement and an uniphasic and lesser medullary enhancement pattern compared to that observed in normal allografts (p < 0.05). A close correlation (r = 0.72) was found between serum creatinine concentration levels and changes in SI. Thus, MR imaging results and histopathology were in agreement in 22 of 23 patients (96%). MR perfusion imaging of renal allografts can be used to noninvasively differentiate ATN from AAR during the post-transplant period, and may also be helpful in cases were covert AAR is superimposing ATN during a phase of anuria. Patients with ATN can be separated from normals in the majority of cases as reflected by an uniphasic medullary enhancement pattern.

Adult↗

Primary vesicoureteral reflux in infants with a dilated fetal urinary tract.

Vesicoureteral reflux (VUR) was recognized neonatally by voiding cystography in 25 of 117 infants with a dilated fetal urinary tract. There was a male preponderance (76%) and a high percentage (40%) of associated urinary malformations. Thirty-nine refluxing units were studied. All grades of VUR were detected but gross dilating VUR dominated (59%). Spontaneous resolution was excellent in lower grades of VUR but was poor in gross VUR. Surgery was successfully performed in 13 renal units of nine patients with gross reflux, additional ipsilateral malformations, or pyelonephritis during antibiotic prophylaxis. Segmental renal scars developed in four kidneys after urinary infections, and a diffuse parenchymal lesion was noted in nine kidneys even at birth. One boy with duplication had a non-functioning refluxing system. Our results in a small number of infants show differences to children with VUR detected after urinary infections and seem to support the existence of a congenital reflux nephropathy.

Cystostomy↗

Doppler sonography in congenital ureteropelvic junction obstruction and multicystic dysplastic kidneys.

The accurate diagnosis of severe congenital ureteropelvic junction obstruction (UPJO) and the indications for surgical intervention are a matter of debate. Differential diagnosis from, for example, congenital cystic kidney malformations is important. In the present study we analysed the value of Doppler sonography (DS) for assessment of obstruction in congenital UPJO and its usefulness for differential diagnosis. A total of 138 infants and children were examined. Forty-three healthy infants and 24 children who had had a pyeloplasty at least 1 year previously served as control groups. Seventy-one children with UPJO and cystic kidney malformations underwent DS in addition to the usual examinations of intravenous urography and scintigraphy. Resistive Index (RI) was measured in both kidneys. Twenty infants showed decompensated UPJO and had needed an operation. Preoperatively all showed significantly increased RI (RI = 74%), which returned to normal after operation (RI = 68.3%). Thirty-nine children with UPJO could be managed conservatively, showing compensated obstruction on diuretic renography. On DS they had normal and symmetrical RI values (RI = 67%). Eleven children had multicystic dysplastic kidneys; 4 underwent nephrectomy. On DS all showed either absence of perfusion signals or very low flow velocities with very high RI values (RI = 90-100%) in the renal vessels. One child was found to be suffering from a cystic nephroma. DS was able to reveal quite normal vessel distribution in renal parenchyma with slightly elevated RI values (RI = 80%). Our results indicate that DS a non-invasive, non-ionising method of investigation, may serve as an additional functional parameter for defining accurately the degree of obstruction in UPJO.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

A multivitamin infusion prevents lipid peroxidation and improves transplantation performance.

The objective of this study was to test the hypothesis that ischemia reperfusion damage in kidney transplantation is associated with lipid peroxidation and that inhibition of lipid peroxidation by antioxidants improves the function of the transplanted kidney. Lipid peroxidation was assessed by measuring the plasma malonaldehyde content (as thiobarbituric acid reaction product) with high-performance liquid chromatography. Kidney function was assessed by plasma creatinine and creatinine clearance. Thirty patients of an ongoing series were randomly selected into two groups, with 14 controls and 16 patients in the antioxidant therapy group. Therapy consisted of two ampoules of Omnibionta (which contains vitamins C, E, A and B complex) diluted in 500 ml physiological sodium chloride, which was infused intravenously prior to reperfusion onset. No significant differences existed for the age of the patients in the control (43.00 +/- 9.86 years) and the therapy group (41.56 +/- 14.14 years) nor in the kidney preservation time, which was 24.12 +/- 8.73 and 18.43 +/- 9.97 hours in the control and therapy group, respectively. The controls showed a transient increase of plasma lipid peroxides as measured by malonaldehyde with a peak one hour after onset of reperfusion. Compared to the baseline value of 0.74 +/- 0.26 (mean +/- SD) the one hour malonaldehyde value increased to 1.46 +/- 0.22 nmol/ml (P < 0.001). In the therapy group the plasma malonaldehyde level did not increase, but slightly decreased by about 20% compared to the baseline value. The difference of plasma malonaldehyde between the two groups one hour after reperfusion onset was highly significant (P > 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Therapy and prognosis of children with prenatally diagnosed urinary tract abnormalities].

Urinary tract malformations are recognized already prenatally to an increasing extent, but the indications for, and the time of surgical intervention are still a matter of debate. The present study is an analysis of the data collected over an 80-month period of 76 patients whose urinary tract malformation was suspected prenatally and confirmed after birth. Patients with lethal malformations whose disease led to abortion or intrauterine death were excluded. Ureteropelvic junction obstruction was present in 47% of the patients and obstructive uropathy accounted for 67% of all malformations. In contrast, vesicoureteric reflux was found only in eight patients. Thirty seven infants (49%) required surgical intervention and 61% of all operations were performed during the first month of life. 57% of these early interventions were temporary diversions. The indication for surgical treatment was based on sonographic and radiological assessment of the malformation and on the results of functional assessment. In many instances surgery was delayed until indicated on the basis of the findings of the follow-up studies. All reconstruction operations were successful. Prenatal diagnosis benefitted most children, especially those with the most severe malformations. No patient died as a result of the renal condition and the prognosis is grave in only one child, who is likely to go into terminal renal failure in childhood.

Congenital Abnormalities↗

Organ-preserving surgery in patients with urothelial tumors of the upper urinary tract.

The Austrian Urological Oncology Group reports on 55 organ-preserving operations in 52 patients with tumors of the upper urinary tract epithelium. The data were gathered from 12 urological departments in the country. There was no evidence of distant metastases in any of the patients at the time of surgery. The observation period ranged from 0.5 to 12 years. 69.2% (36 of 52) of the patients were alive and recurrence-free at the time of data collection, after a mean observation period of 41.4 months. 9.6% died for reasons other than cancer after an average of 18.8 months, and 21.2% were still alive with or had died due to recurrent tumors. The recurrence rate after open surgery was similar in tumors of the upper ureter or pelvis (15.3%) as in tumors of the lower ureter (17.6%). After endoscopic treatment 4 of 9 patients showed recurrences. 92% (22 of 24) of the patients with no compelling indication for organ-preserving therapy were alive and recurrence-free or had died due to other causes. Therefore organ-preserving surgery appears to be appropriate in tumors of the upper urinary tract epithelium.

Aged↗

[Primary malignant tumors of the small intestine. A review with demonstration of a case].

Malign tumours in the small bowel are rarely found. A survey is given on appearance, symptoms, diagnosis and therapy of these tumours (by exclusion of the tumours of the duodenum and the tumours derived from Meckel's diverticulum). By means of a case report and a number of observed patients it is demonstrated, how the non-characteristic symptoms cause a late diagnosis and therefore late therapy.

Adenocarcinoma, Papillary↗

Prostatectomy with a no-catheter technique.

A method of no-catheter prostatectomy is described and the results of 350 operations are presented. It has been demonstrated that this method of prostatectomy can be done aseptically.

Humans↗

The role of angiography in diagnosis and management of blunt renal trauma.

In a series of 223 patients with blunt renal injury, 40 patients underwent angiography. From this experience the following conclusions have been drawn: If a renal injury is suspected the IVP must be done as soon as possible. In most cases the diagnosis can be confirmed. Mild injuries should be managed conservatively and therefore need no angiography. In life endangering injury there is no time for angiography. The operation should be done preferably by a transperitoneal approach to allow good control of the renal pedicle. Patients with severe injuries should undergo angiography. If there is no function on the IVP, angiography should be done immediately to diagnose possible arterial thrombosis. In most cases angiography can be carried out some days after the trauma. This investigation provides an exact diagnosis and helps in deciding about further treatment. If a major part of the kidney has no blood supply, or there is a rupture with a large perirenal extravasation of urine, we recommend conservative surgery to avoid early and late complications. All operations should be done some days after the trauma. All patients with renal injuries, either operated or conservatively managed, should be carefully followed up. Angiography should be done in all cases of post-traumatic hypertension.

Angiography↗