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Biomedical subjects

R Waldherr

Publications and source records attributed to R Waldherr.

At least 145 records · Page 8Linked to original sources
PubMed1990

Ureterosigmoidostomy: long-term results, risk of carcinoma and etiological factors for carcinogenesis.

We followed postoperatively 75 patients who underwent ureterosigmoidostomy between 1942 and 1987. Of the patients 30 were asked to undergo routine examination, including fiberoptic sigmoidoscopy with biopsy and analysis of a urine-feces slurry for nitrate, nitrite and nitrosamines in comparison to 20 control volunteers. After a mean observation of 14 years 7 months (1 to 46 years) 64.5% of the patients had bilaterally normal kidneys without any previous complications, 77.5% of the renal units being normal. Sigmoidoscopic biopsy revealed 3 carcinomas at the ureterocolonic junction resulting in an 8.5 to 10.5-fold increased risk of colon carcinoma compared to the general population. The excretion of nitrite and N-nitrosamines was increased, and nitrate excretion was decreased compared to healthy control volunteers, suggesting endogenous formation of nitrosamines by bacterially reduced nitrate and endogenous amines. The urological long-term results of ureterosigmoidostomy are similar to those of conduits. However, the increased incidence of colon carcinoma is not yet proved to be higher than in conduits.

Adult↗
PubMed1990

Heterogeneity of intermediate filament expression in human testicular seminomas.

Testicular seminoma has in the past been considered to represent a germ cell tumor incapable of further differentiation. In recent years this view has been challenged on the basis of morphologic and chromosomal studies. Moreover, studies of intermediate filaments (IF) of seminoma cells have provided evidence of the capability of seminoma cells to differentiate in different directions. In the present study of the IF protein profile of 26 human testicular seminomas, using frozen as well as formalin-fixed, paraffin-embedded tissues, we report evidence of a heterogeneous differentiation potential inherent in these neoplasms. Thus, in 4 of the seminomas neither cytokeratins nor vimentin were detected; 3 showed vimentin positive cells but no cytokeratins; in 4 seminomas only cytokeratins were detected. In the remaining 15 cases both cytokeratins and vimentin were present, with occasional cells demonstrating coexpression of cytokeratin and vimentin. While the cytokeratins present were mostly of the "simple epithelial type", in 2 instances seminoma cells also contained cytokeratins 4 and 17, normally found in stratified and/or complex glandular epithelia. Furthermore, in 3 cases scattered tumor cells stained for desmin and in 2 other seminomas neurofilaments were identified. All of the cases showed variable positive staining for desmoplakins and desmoglein, indicative of the presence of desmosomes. It can therefore be concluded that, while some seminomas seem to be devoid of IFs, most of them show varied differentiation patterns usually with epithelial features but occasionally also with components commonly regarded as characteristic of myogenic or neurogenic differentiation. These observations may help to elucidate the relationship of seminomas to other germ cell tumors, and also contribute to our understanding of the histogenesis of these neoplasms.

Desmin↗
PubMed1990

Role of the kidney in primary hypertension: a renal transplantation study in rats.

We have previously shown that transplantation of kidneys from genetically hypertensive to normotensive rats result in hypertension in renal graft recipients. To investigate whether this posttransplantation hypertension may have been the result of damage to the renal graft by high perfusion pressure before transplantation, we normalized blood pressure throughout life in spontaneously hypertensive rat (SHR) kidney donors by continuous antihypertensive treatment with the angiotensin-converting enzyme inhibitor ramipril (1 mg.kg-1.day-1 in drinking fluid). When kidneys from these rats were transplanted at age 20 wk to age-matched bilaterally nephrectomized F1 hybrids bred from SHR and Wistar-Kyoto (WKY) parents, posttransplantation hypertension still developed. In contrast, blood pressure did not change significantly in recipients of kidneys from ramipril-treated WKY rats. In the initial phase, recipients of SHR kidneys had a lower body weight and higher plasma urea concentrations than recipients of WKY kidneys. However, in the chronic phase, there were no significant differences between the two groups with respect to daily water intake, plasma urea concentration, glomerular filtration rate, renal blood flow, and weight of transplanted kidneys; no histological differences were observed between renal grafts from WKY and SHR donors, except for structural vascular hypertrophy in the latter group. We conclude that posttransplantation hypertension in recipients of SHR kidney grafts also develops, when the grafts have not been subjected to high renal perfusion pressure before transplantation. Our data support the hypothesis that SHR kidneys carry a primary defect, which can induce hypertension in renal graft recipients.

Animals↗
PubMed1990

Hypertension in rats induced by renal grafts from renovascular hypertensive donors.

Renal transplantations were performed, using microsurgical techniques, with adult male two-kidney, one clip hypertensive rats (n = 9) and sham-operated normotensive Wistar-Kyoto rats (n = 8) as kidney donors and with F1 hybrids, bred from Wistar-Kyoto and stroke-prone spontaneously hypertensive rat parents, as recipients. Systolic blood pressure before surgery was 200 +/- 2.7 mm Hg in hypertensive and 115 +/- 1.7 mm Hg in normotensive donors and 144 +/- 7.1 and 138 +/- 3.5 mm Hg in the two groups of recipients. Renal hypertension in donors was maintained for 14 weeks before surgery was performed and the nonischemic kidneys were transplanted. Bilaterally nephrectomized recipients of renal grafts from hypertensive donors developed sustained hypertension (185 +/- 3.9 mm Hg). In contrast, in recipients of renal grafts from normotensive donors, blood pressure decreased significantly to the level of the donors (111 +/- 3.7 mm Hg). Posttransplantation hypertension in recipients of renal grafts from hypertensive donors was associated with intrarenal vascular hypertrophy, smaller kidneys, a decreased glomerular filtration rate, an increased plasma urea concentration, and polydipsia as compared with normotensive transplanted controls. Renal pyelograms revealed no gross anatomic alterations of transplanted kidneys. Our data indicate that secondary damage to the renal grafts caused by high perfusion pressure before transplantation can induce hypertension in recipients of these kidneys. Furthermore, our data suggest that renal mechanisms may be necessary to maintain borderline hypertension in F1 hybrids.

Animals↗
PubMed1990

[Wilms' tumor in adults].

We report on a 42-year-old patient with a Wilms tumour (nephroblastoma) of the right kidney, which was detected incidentally by sonography. Both radiological examination and intraoperative examination of a quick-frozen section led to a diagnosis of malignant renal tumour. Post-operative histological examination showed a nephroblastoma of predominantly epithelial cell type with no signs of anaplasia. Only about 210 cases of Wilms tumours in adults have been reported in the world literature so far. Because of this low incidence and the frequent lack of any clear distinction from sarcomatoid renal cell carcinoma in terminology and histology, no standardized therapy regimens exist. The prognosis with a 3-year survival rate of 24%-44% is poor compared with that of Wilms tumours in children. In a literature review the current status of knowledge about nephroblastomas in adults is discussed.

Adult↗
PubMed1990

Surgical treatment of soft tissue tumors of the stomach.

Between 1977 and 1989 46 patients with soft tissue tumors of the stomach were treated at the Department of Surgery, University of Heidelberg. Twenty-one tumors were malignant and 25 benign. Sixteen of 21 malignant and 13 of 25 benign tumors originated from smooth muscle. Surgical therapy consisted of local excision of the tumor with a margin of gastric wall, or partial gastrectomy. One patient required total gastrectomy for complete removal of the tumor. The adjusted 5-year survival of all 21 patients with malignant tumors was 71% calculated by life-table analysis. Prognostic factors were local invasion and distant metastases. None of 15 patients without local invasion or metastasis has died of disease at a mean follow-up of 3.1 +/- 0.7 years (range 0.1 to 5.8 years) and only one of these patients had tumor recurrence. Nucleolar organizer regions (NOR) were determined in 16 malignant tumors of myogenic origin. Low (less than 4.0/nucleus) NOR counts indicated good prognosis with an adjusted 5-year survival of 100% in 11 patients as compared to 30% for five patients with more than 4.0 NOR/nucleus. Complete removal of the tumor together with a 2-cm margin without radical lymphadenectomy appears to be adequate surgical treatment. The indications for adjuvant therapy in patients with curative surgery and the value of chemotherapy or radiotherapy for treatment of persistent or recurrent disease remain to be established. NOR studies may help to identify patients at high risk.

Combined Modality Therapy↗
PubMed1989

Nucleolar organizer regions in myogenic stromal tumours of the stomach.

Silver staining of nucleolar organizer regions (AgNOR) was studied in 26 primary benign and malignant gastric stromal tumours of myogenic origin. The absolute number of AgNOR per nucleus and the size of AgNOR were compared with histomorphologic features of the tumours. The total number of AgNOR per nucleus in epithelioid and spindle cell leiomyosarcomas significantly (p less than 0.001) exceeded that in leiomyomas, cellular leiomyomas and epithelioid leiomyoblastomas. The mean number or the size of AgNOR did not correlate with the number of mitoses or the tumour size. In addition, large and bizarre AgNOR were seen predominantly in histologically malignant tumours. Only one exceptional epithelioid leiomyoblastoma recurred despite a lack of conventional characteristics of malignancy and a low AgNOR count. Therefore, quantitative determination of the number of AgNOR is a new independent variable in myogenic gastric tumours. It provides additional information for the histopathological evaluation of this heterogenous group of mesenchymal tumours.

Humans↗
PubMed1989

Rate of deterioration of renal function in juvenile nephronophthisis.

The rate of deterioration of renal function was determined in 29 patients with juvenile nephronophthisis presenting before the age of 18.5 years. The analysis was based on 618 serial determinations of serum creatinine (SCR). By application of a new statistical method the time elapsing between different successive SCR levels was calculated. A more or less homogeneous increase of SCR was noted starting from the time when a SCR of 4 mg/dl was reached. The median time elapsing between an SCR of 2 and 4 mg/dl was 32 months, between 4 and 6 mg/dl 10 months and between 6 and 8 mg/dl 5 months. The median age at the start of renal replacement therapy or death due to uraemia, evaluated by survival analysis, was similar in both sexes.

Adolescent↗
PubMed1989

Acrorenal syndrome in an adult--presentation with proteinuria, hypertension, and glomerular lesions.

Acrorenal syndrome is characterized by central longitudinal axis defects of the limbs, ie, split hand and/or foot. Associated renal lesions described so far comprise agenesis, bilateral hypoplasia (originally diagnosed as oligomeganephronia), and duplication abnormalities. The case of a 29-year-old patient with split hand resulting from bilateral aplasia of the third phalanges associated with dysplasia of the third and fourth metacarpals is reported. In addition, the following lesions were noted: hypoplasia of the middle phalanx of the fifth toe, arched palate, pectus excavatum, hypoplastic mammilae, scoliosis, and congenital hip dislocation. The patient presented with hypertension, modest reduction of glomerular filtration, proteinuria, microhematuria, cylindruria, and moderate harmonic hypoplasia of the right kidney on angiography. Glomeruli had no immune deposits on immunohistology. Light microscopy showed widening of the mesangial axis, focal segmental glomerular sclerosis, and renal interstitial fibrosis with occasional foam cells. This case shows that the spectrum of renal abnormalities in the acrorenal syndrome is wider than previously noted.

Abnormalities, Multiple↗
PubMed1989

Lysine-specific cleavage of beta 2-microglobulin in amyloid deposits associated with hemodialysis.

Amyloid fibrils isolated from bone and carpal synovia of seven patients on long-term hemodialysis were further characterized biochemically. In addition, renal amyloid stones of three dialyzed patients were examined. All deposits and stones were of beta 2-microglobulin-origin (AB-amyloid) by immunohistochemical and immunochemical evaluation. Amyloid fibril extracts were dissolved in 80% formic acid and separated by high performance liquid chromatography in 60% formic acid and 20% 2-propanol. Three major retarded fractions with molecular weights of approximately 24, 12 and 7 to 10 kD were recovered. N-terminal amino acid sequence analysis documented beta 2-microglobulin (beta 2m) as the principal polypeptide in all investigated cases. In addition to proteins with intact N-termini, one fragment commencing with isoleucine in position 7 was found in osseous or synovial amyloid. In renal amyloid stones, one additional fragment was found beginning with serine in position 20. Generally, these data point to proteolytic cleavage carboxyterminal to a lysine residue and establish that not only intact beta 2m but also at least one beta 2m fragment is present in beta 2m-derived amyloid deposits of patients with long-term hemodialysis. The fragmentation pattern is consistent with the action of lysine-specific protease(s) and underscores a potentially important role of limited proteolysis in the pathogenesis of AB-amyloid deposits.

Adult↗
PubMed1989

Frequency of mesangial IgA deposits in a non-selected autopsy series.

The frequency of mesangial IgA deposition was examined in 250 consecutive autopsy cases without known renal disease. Diffuse granular mesangial deposits of IgA were detected in 12 of 250 cases (4.8%). In six patients IgA deposits were associated with liver cirrhosis. Six patients (2.4%) suffered from various other conditions including endocarditis, bronchial asthma, cardiovascular disease, and neoplasia. Two of these patients had completely negative urine analysis on repeated investigations, whereas three patients exhibited microscopic haematuria and/or mild proteinuria. IgA1 was the major constituent in all specimens. C3c deposits in glomeruli were detected in one kidney. Our findings indicate that clinically overt renal disease is present in only a limited proportion of individuals with mesangial IgA deposits. Apparently, it represents the tip of an iceberg.

Antibodies, Monoclonal↗
PubMed1989

Hypertension in chronic idiopathic glomerulonephritis: analysis of 311 biopsied patients.

Prevalence of hypertension and relation of hypertension to renal function, type of glomerulonephritis or histological features were evaluated in 311 patients with idiopathic chronic glomerulonephritis. The overall prevalence of hypertension was 49.8%. At least in women, prevalence of hypertension was increased even at serum creatinine levels less than 1.1 mg dl-1 compared with the local general population. Prevalence of hypertension was 2.12 and 8.6 fold higher at serum creatinine 1.1-1.4 mg dl-1 in males and females respectively. In patients with untreated hypertension, a relation was found between mean blood pressure and subsequent decline of estimated GFR. Furthermore, in patients with arterial sclerosis, but not in patients without, a significant relation was found between blood pressure and subsequent increase in serum creatinine.

Adolescent↗