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R Riess

Publications and source records attributed to R Riess.

At least 19 recordsLinked to original sources
PubMed2006

Local VEGF activity but not VEGF expression is tightly regulated during diabetic nephropathy in man.

Several studies have implicated the angiogenic cytokine vascular endothelial growth factor (VEGF) in the development of diabetic nephropathy, but no data are available about its local activity during human disease. Glomeruli from 52 archival biopsies from type II diabetics were evaluated and compared to 10 renal biopsies without kidney disease (controls). Glomerulosclerosis, capillary rarefaction, glomerular and endothelial cell proliferation, apoptosis, VEGF expression, as well as receptor-bound VEGF indicating local VEGF activity, and phosphorylation of the signal transduction molecule Akt were investigated. Owing to substantial heterogeneity of glomerular lesions in individual biopsies, these parameters were correlated with the degree of injury in individual glomeruli rather than biopsies. Severe glomerular capillary rarefaction was linked to the degree of glomerulosclerosis. While cellular apoptosis was detected independent of the stage of injury, endothelial cell proliferation indicating capillary repair was markedly increased only in mildly/moderately injured glomeruli. In controls, VEGF was predominantly expressed in podocytes, whereas receptor-bound VEGF was confined to the glomerular endothelium. VEGF expression was increased in all diabetic glomeruli by many different cell types. In contrast, VEGF receptor activation was increased predominantly in the endothelium of only mildly injured glomeruli, but significantly decreased in more severely injured glomeruli. Diabetic nephropathy is associated with glomerular capillary rarefaction. Despite overall increased glomerular VEGF, the decreased receptor-bound VEGF on the endothelium may be an indicator of an insufficient capillary repair reaction.

Aged↗
PubMed2001

Expression of multidrug resistance P-glycoprotein in kidney allografts from cyclosporine A-treated patients.

BACKGROUND: The multidrug resistance (MDR) gene product P-glycoprotein (P-gp) is a transmembrane efflux pump for hydrophobic, potentially toxic compounds, including the immunosuppressant cyclosporine A (CsA). We have previously shown that CsA increases P-gp expression in proximal tubule and endothelial cells in vitro. The aim of the present study was to investigate the in vivo relevance of these observations in renal allograft biopsies from CsA-treated patients. METHODS: P-gp expression was determined by immunohistochemistry of paraffin sections using two different monoclonal antibodies (UIC2 and MRK16). Biopsies were taken from CsA-treated renal transplant patients with different histopathological diagnoses (N = 79) and were compared with biopsies from normal human kidneys (N = 13) or with allograft biopsies from patients under a CsA-free immunosuppression (N = 15). Moreover, biopsies from 10 donor kidneys before implantation and during rejection episodes ("zero biopsies") were investigated. RESULTS: P-gp expression in biopsies with acute tubular necrosis (ATN; N = 10) after CsA treatment was significantly higher in arterial endothelia, proximal tubules, and epithelial cells of Bowman's capsule (BC), whereas P-gp was sparsely induced in CsA nephrotoxicity (N = 19) compared with controls. Acute cellular (N = 30) and vascular rejection (N = 10) or chronic allograft nephropathy (N = 10) after CsA was associated with strong P-gp expression in infiltrating leukocytes and increased P-gp expression in arterial endothelia, proximal tubules, and BC. In contrast, biopsies of patients treated with a CsA-free immunosuppression regimen did not show increases in P-gp expression compared with controls. Zero biopsies showed a weak, homogeneous, nonpolarized expression of P-gp in tubules and an increased expression of P-gp after CsA therapy in the brush border, arterial endothelia, and BC. CONCLUSIONS: CsA treatment was associated with increased P-gp expression in parenchymal cells of kidney transplants with ATN, acute or chronic transplant rejection, but P-gp was not increased in patients with CsA nephrotoxicity. This indicates that CsA induces its own detoxification by P-gp and that inadequate up-regulation of P-gp in renal parenchymal cells contributes to CsA nephrotoxicity. Increased expression of P-gp in infiltrating leukocytes correlated with the severity of allograft rejection, suggesting that P-gp may decrease the immunosuppressive efficacy of CsA. Thus, individual differences in the P-gp induction response of CsA-exposed renal parenchymal cells and/or infiltrating leukocytes may predispose to either CsA nephrotoxicity or rejection, respectively.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Immunohistochemical investigations on the course of astroglial GFAP expression following human brain injury.

The course of GFAP expression by astrocytes has been immunohistochemically investigated during the first 30 weeks after human brain injury. In order to provide reliable data for a forensic wound age estimation, a quantitative morphometric analysis was performed considering the different topographic regions of the cortex as well as of the white matter. Compared to the GFAP immunoreactivity in unaltered control tissue, significantly increased numbers of GFAP positive astroglial cells could be detected adjacent to the cortical contusion from 1 day up to 4 weeks after brain injury.

Adolescent↗
PubMed2000

Prognostic value of the Banff classification.

UNLABELLED: We evaluated whether classification of renal allograft biopsies according to the Banff schema is a predictive parameter for graft survival. All patients who received renal transplants between 1980 and 1994 at the University of Erlangen-Nuremberg (n = 1141) were included. Patients who had undergone a renal biopsy (n = 306) were divided into groups according to the Banff classification. We observed a correlation (P < 0.05) between biopsy findings and the following patient characteristics: donor/recipient age, donor/recipient gender, panel reactive antibodies, maintenance immunosuppression, and primary renal disease. Compared to patients who did not undergo renal biopsy (55.9%), 5-year graft survival was reduced in patients with moderate acute rejection defined by tubulitis (20.6%, P = 0.03) or arteritis (0%; P < 0.0001) and in patients with severe acute rejection (24.4%, P < 0.0001). CONCLUSIONS: (1). The Banff classification is a predictive parameter for renal allograft survival. (2). Certain characteristics predispose patients to certain biopsy findings.

Adult↗
PubMed1999

[An unusual cause of hepatorenal symptoms].

CASE REPORT: A 65-year-old patient with normal blood pressure had an exclusive elevation of the cholestasis enzymes (alkaline phosphatase 297 U/l, gamma-GT 315 U/l) and elevated bilirubin levels (1.4 mg/dl) since August 1994. A biopsy of the liver in March 1995 showed features of a "subacute viral hepatitis"; DD drug-induced or toxic lesions. Serological tests gave no support for an acute hepatitis. Intra- or extrahepatic cholestasis could not be proved neither by ultrasound nor by an endoscopic retrograde cholangiopancreatography. Since November 1995 serum creatinine increased up to 1.7 mg/dl (March 1995 1.1 mg/dl) and proteinuria (2.1 g/d) developed. Due to worsening of renal function (serum creatinine 2.8 mg/dl) and increasing proteinuria (3.5 g/d) without nephrotic syndrome, a kidney biopsy was performed. Histologically an amyloidosis (type A lambda) was proven, involving glomerula, kidney vessels and tubules. Further biopsies from the stomach and the duodenum showed profound infiltration of the mucosa and submucosa with amyloid. Therefore, staining of the liver biopsy of March 1995 with congo red proved the diagnosis of liver amyloidosis. By a punch biopsy of the iliac crest a low-grade non-Hodgkin's lymphoma could be identified as the cause for this generalized amyloidosis. DISCUSSION: In the present case, the reason for these unusual hepatorenal symptoms with unclear cholestasis over years as the first clinical symptom and a succeeding progressive renal insufficiency with proteinuria could be found by the use of kidney biopsy and extending the analysis of a liver sample taken by biopsy 1 year ago. Immunoglobulin light chains produced by a low-grade non-Hodgkin's lymphoma caused a generalized amyloidosis type A lambda. CONCLUSION: As a consequence, by an occurrence of unusual hepatorenal symptoms with cholestasis and progressive renal failure, amyloidosis should be considered as a pathogenetic factor.

Aged↗
PubMed1998

'Eye-witness'.

Explore the source record for details and available documents.

Adult↗
PubMed1997

[The first manifestations of Schönlein-Henoch purpura in a 74-year-old female patient with hyperthyroidism].

HISTORY AND CLINICAL FINDINGS: A 74-year-old woman had for 3 weeks suffered from watery diarrhoea and diffuse abdominal pain. She felt restless, had a subfebrile temperature (37.8 degrees C), tachycardia and a blood pressure of 190/90 mmHg. Shortly after admission petechiae were found over the lower legs and she complained of joint pains. INVESTIGATIONS: Laboratory tests established hyperthyroidism. Skin biopsy showed leukocytoclastic vasculitis. Tests for antinuclear antibodies, antistreptolysin titre, rheumatoid factors, cryoglobulins and TSH-receptor antibodies were negative, immunoglobulin A (IgA) was raised. TREATMENT AND COURSE: As a drug-induced vasculitis was suspected treatment was started with methylprednisolone, 100 mg daily. Proteinuria (5.6 g daily) indicated renal biopsy, which revealed focal glomerulonephritis with deposits of IgA, fibrin/fibrinogen and complement factor 3. Gastroscopic biopsy, performed after an episode of gastrointestinal bleeding, demonstrated necrotizing vasculitis, confirming the diagnosis of Schönlein-Henoch-purpura (SHP). As the patient's condition rapidly worsened, cyclophosphamide was started additionally (2 mg/kg). She died on the 17th hospital day from acute cardiac failure. CONCLUSION: The lethal course of the disease in this elderly patient illustrates a previously not reported close temporal and clinical relationship between SHP and hyperthyroidism.

Abdominal Pain↗
PubMed1997

Interleukin-6 expression after renal transplantation.

BACKGROUND: Interleukin-6 (IL-6) is an inflammatory cytokine that plays a role in transplant rejection. We tested the hypothesis that IL-6 levels in serum or urine could be of value in predicting acute and chronic allograft rejection. Furthermore, we examined whether or not such levels reflected IL-6 expression in the kidney. METHODS: We measured IL-6 and IL-6 soluble receptor (IL-6sR) in serum and urine of 145 transplant patients and 20 normal controls. In parallel, we studied 108 renal biopsies. IL-6 was measured with a bioassay system using an IL-6 dependent cell line. IL-6sR was measured with enzyme-linked immunosorbent assay. The biopsies were examined for IL-6 and IL-6 receptor (IL-6R) expression with immunohistochemistry. RESULTS: Rejection episodes occurring within 2 months of transplantation were accompanied by elevated IL-6 concentrations in serum (17 +/- 4.8 pg/ml, P < 0.05) and urine (114 +/- 27 pg/ml, P < 0.005), compared to controls. These values returned towards baseline (0-5 pg/ml) after successful rejection treatment. The sensitivity of urine measurements was much higher (93%) than serum (54%). The specificity in serum (70%) and urine (60%) was reduced by infection, acute tubular necrosis, and antithymocyte globulin treatment. Serum and urine IL-6sR values did not correlate with rejection. In biopsy tissue, IL-6 and IL-6R were both elevated during rejection. Especially, mononuclear cells within the interstitial infiltrate stained positive. However, the amount of IL-6 positive cells did not correlate with peripheral IL-6 concentrations. CONCLUSIONS: Urine but not serum IL-6 values are sensitive indicators of rejection; however, they are confounded by infection, acute tubular necrosis, and certain antirejection treatments. These features limit their usefulness.

Acute Disease↗
PubMed1997

Expression of cell adhesion molecules in primary renal disease and renal allograft rejection.

BACKGROUND: In vitro studies have demonstrated that inflammatory mediators such as the cytokines TNF alpha and IL-1 upregulate or induce de novo expression of cell adhesion molecules on endothelial and epithelial cells. In the present study the expression of the cell adhesion molecules ICAM-1, VCAM-1, E-selectin and PECAM-1 was investigated in renal biopsies from patients with primary renal diseases (n = 66) and from renal allograft recipients (n = 42). METHODS: Expression of the cell adhesion molecules was determined by immunohistochemistry of frozen sections using monoclonal antibodies directed against PECAM-1, ICAM-1, VCAM-1, E-selectin and MHC class II molecules (APAAP method). RESULTS AND CONCLUSIONS: PECAM-1 and ICAM-1 were expressed in the renal vasculature and disappeared in obliterated glomeruli with endothelial cell destruction. ICAM-1 but not PECAM-1 was upregulated in renal endothelia in acute allograft rejection and inflammatory primary renal diseases. Tubular de novo expression of ICAM-1 and VCAM-1 correlated with severe structural damage of the renal parenchyma including interstitial fibrosis. Vascular and/or glomerular VCAM-1 and E-selectin expression was pronounced in severe acute allograft rejection and also reflected the intensity of inflammatory reactions in primary renal diseases with or without autoimmune disorders. De novo expression of VCAM-1 and E-selectin in renal vessels and/or glomeruli and overexpression of ICAM-1 are markers of acute and severe inflammatory processes in biopsies from allograft recipients and patients with primary renal diseases.

E-Selectin↗
PubMed1995

Glomerulopathy associated with predominant fibronectin deposits: a newly recognized hereditary disease.

A newly recognized type of familial glomerulopathy observed in patients of both sexes in six families is reported. Proteinuria, often within the nephrotic range, microscopic hematuria, hypertension and a slowly decreasing renal function over several years were common. No underlying systemic diseases were identified. Generally, light microscopy showed enlarged glomeruli with minimal hypercellularity and with extensive deposits in the mesangium and subendothelial space. By electron microscopy, granular deposits with some admixture of fibrils were most common. In one family, the deposits were predominantly fibrillary. Immunoglobulins and complement factors were inconstant or lacking. A main finding was a strong immune reactivity to fibronectin, corresponding to the distribution of the deposits. In one patient, the deposits recurred in a renal transplant. There was no indication of systemic deposition. Abnormalities in the metabolism of circulating fibronectin may play a pathogenetic role in this disease of probably autosomal dominant inheritance.

Adolescent↗
PubMed1994

Kidneys from pediatric donors: risk versus benefit.

We encountered four adult patients who received renal transplants from young children < 36 months of age, each of whom developed severe hypertension, heavy proteinuria, and progressive renal failure. Biopsies disclosed glomerular sclerosis with crescents in three patients and mesangial expansion in one. We thus analyzed our experience with 74 adults who received grafts from donors < or = 10 years of age and compared the results to those of 804 patients who were transplanted with kidneys from donors > 10 years of age. A Kaplan-Meier analysis revealed that graft survival was significantly worse in patients receiving grafts from younger, compared to older donors. This difference was apparent in patients treated either with or without cyclosporine. A subanalysis comparing patients with donor grafts aged < or = 5 or 6-10 years revealed a further adverse age-related effect. Renal artery thrombosis and recurrent or de novo biopsy-proven glomerulonephritis were more common in patients receiving grafts from younger donors, while graft failure from rejection actually appeared less common. We conclude that severe hypertension and resultant glomerular hyperperfusion promoted glomerulosclerosis and crescent formation in our patients. Our results have caused us to pursue a more conservative approach towards transplanting grafts from donors aged < or = 10 years into adult recipients.

Adult↗
PubMed1992

A method for quantitative determination of flow induced human platelet adhesion and aggregation.

Adhesivity and aggregability of blood platelets may reflect normal and diseased states. A quantitative assessment of such reactivity should thus provide further insight into disease mechanism. The well defined conditions of stagnation point flow using platelet-rich-plasma (PRP) as fluid permit quantitative treatment of the formation of platelet microthrombi on the stagnation plate. By measuring the growth kinetics (photometry) and corresponding morphology (light- and electron microscopy) of the microthrombus, platelet adhesion as well as aggregation could be analyzed separately by means of a quantitative procedure. Parameters are evaluated for PRP samples obtained from patients exhibiting deep venous thrombosis, arterial angiopathy or myocardial infarction, respectively. The results obtained demonstrate the usefulness of the proposed method for quantifying platelet reactivity as reflected by type and degree of flow induced platelet deposition. This, in turn, provides a basis for correlating the in vitro findings with the disease state.

Humans↗
PubMed1990

[Prenatal diagnosis of a sacrococcygeal teratoma with hydrops fetalis and placental hypertrophy--consequences for the further course of pregnancy].

A fetal sacrococcygeal teratoma may cause hypertrophy of the placenta and fetal hydrops. This is dangerous for the fetus and also for the mother. The maternal risk results from preeclampsia and respiratory insufficiency, associated with elevated beta-HCG. In that case, pregnancy should be terminated by caesarean section due to maternal reasons.

Adult↗