Wilms' tumor suppressor gene WT1: from structure to renal pathophysiologic features.

Normal development of the kidney is a highly complex process that requires precise orchestration of proliferation, differentiation, and apoptosis. In the past few years, a number of genes that regulate these processes, and hence play pivotal roles in kidney development, have been identified. The Wilms' tumor suppressor gene WT1 has been shown to be one of these essential regulators of kidney development, and mutations in this gene result in the formation of tumors and developmental abnormalities such as the Denys-Drash and Frasier syndromes. A fascinating aspect of the WT1 gene is the multitude of isoforms produced from its genomic locus. In this review, our current understanding of the structural features of WT1, how they modulate the transcriptional and post-transcriptional activities of the protein, and how mutations affecting individual isoforms can lead to diseased kidneys is summarized. In addition, results from transgenic experiments, which have yielded important findings regarding the function of WT1 in vivo, are discussed. Finally, data on the unusual feature of RNA editing of WT1 transcripts are presented, and the relevance of RNA editing for the normal functioning of the WT1 protein in the kidney is discussed.

Is dialysis membrane type responsible for increased circulating adhesion molecules during chronic hemodialysis?

BACKGROUND: Patients with chronic renal failure under maintenance hemodialysis (HD) present with numerous adverse effects including immunologic alterations. Serious abnormalities of neutrophil function have been reported to be associated with disturbed cell adhesiveness. These adhesion processes are mediated by cytokines and different adhesion molecules. PATIENTS AND METHODS: In this study, serum concentrations of the intercellular adhesion molecule ICAM-1, vascular cell adhesion molecule VCAM-1 and endothelial leukocyte adhesion molecule E-selectin were investigated during employment of different dialysis membranes (cuprophane: n = 23, cellulose: 8, polysulfone: 26, acrylonitrile: 7). These adhesion parameters from 64 patients before and after a hemodialysis session were investigated parallel to the serum levels of circulating cytokines and their inhibitors. RESULTS: Circulating ICAM-1 levels were not elevated in low-flux membranes and most of the high-flux HD membranes, except for one high-flux polysulfone membrane. cVCAM-1 levels were significantly elevated both in low- and high-flux dialysis membranes, whereas cE-selectin was not increased. cICAM-1 levels were not different before and after hemodialysis in the entire study group. In contrast, cVCAM-1 and cE-selectin levels increased significantly during HD in the entire study group (both p < 0.001). Serum levels did not correlate with the duration of end-stage renal failure and hemodialysis. Levels of circulating cytokine antagonists/inhibitors (Il-lra, Il-2R, TNFsRp55/75) were significantly increased in all patients before and after HD, whereas the serum concentrations of the corresponding circulating cytokines (I1-1beta, Il-1, TNF-alpha) were within normal ranges. CONCLUSION: Increased levels of cVCAM-1 which suggest an important role for immunological alterations in HD and cytokine-independent changes during HD sessions in all membranes without alterations of cICAM-1 in most membranes and unchanged cE-selectin indicate that processes such as uremia are responsible for these effects rather than membrane characteristics. The level of circulating adhesion molecules does not serve as an appropriate marker of membrane biocompatibility.

VCAM-1, ICAM-1, and E-selectin in IgA nephropathy and Schönlein-Henoch syndrome: differences between tissue expression and serum concentration.

The tissue expressions of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1) and endothelial leukocyte adhesion molecule 1 (E-selectin-1) were investigated in biopsy specimens from 28 patients with different stages of IgA nephropathy (IgAN) and 20 patients with acute renal failure (ARF) or chronic renal diseases (amyloidosis, Alport's glomerulopathy) by immunohistochemistry. The results were compared with the serum levels of the three adhesion molecules. VCAM-1 expression was significantly increased on parietal/tubular epithelial cells in IgAN and ARF. Significantly elevated circulating VCAM-1 levels were measured in IgAN and amyloidosis, but did not correlate with renal function (creatinine clearance). Significantly increased glomerular endothelial/epithelial ICAM-1 expression was found in IgAN and ARF. Intense mesangial ICAM-1 expression was found in mild stages of IgAN and in Schönlein-Henoch syndrome. Circulating ICAM-1 was not significantly elevated in IgAN and different renal diseases. VCAM-1 and ICAM-1 expressions of interstitial infiltrating cells were significantly higher in severe than in mild IgAN and associated with an increased infiltration of inflammatory leukocytes. Patients with IgAN and different renal diseases had decreased mesangial and almost absent interstitial E-selectin expression as compared with controls. The circulating E-selectin levels were significantly elevated in ARF. In conclusion, the tissue expression of adhesion molecules in IgAN reflects a continuous inflammatory renal activity. However, only increased circulating VCAM-1 serum levels correlated significantly with the histological state of renal inflammation and could be used as a disease marker.

Cerebral tuberculoma 11 years after renal transplantation.

A case of cerebral tuberculoma in a 39-year-old patient who had received a renal graft from a living related donor 11 years previously is reported. The patient had a major seizure, progressive psychiatric signs and fever 5 days prior to admission. The clinical history suggested a neurological cause and rapid diagnosis of a cerebral tuberculoma was made by a computed tomography-guided stereotactic puncture of a space-occupying cerebral lesion. The aspirated pus contained Mycobacterium tuberculosis. Anti-tuberculous therapy with isoniacid, rifampicin, ethambutol and pyracinamide was administered. Transplant function deteriorated and the patient died due to intractable septicemia with multiorgan failure from pulmonary infection dissemination and additional urinary tract infection with atypical mycobacteria. The chance for a benign clinical course necessitates vigorous procedures for an early diagnosis of cerebral infections in renal transplant recipients with neurological/psychiatric signs.

Isolated cerebral aspergilloma--long-term survival of a renal transplant recipient.

A renal transplant recipient with isolated cerebral aspergilloma 4 months after allograft transplantation is reported. On admission cerebral computed tomography showed a ring-enhancing mass in the left frontal hemisphere and aspirated purulent material revealed A. fumigatus hyphae. He was cured by short-term antifungal therapy and neurosurgical removal of the well demarcated lesion. He is still alive more than two years later and the renal transplant is well functioning. This is the first report of a renal transplant recipient with isolated cerebral aspergillosis without any relapse and only the third patient who has survived longer than 3 months. Early diagnostic procedures with rapid confirmation of aspergillus infection are pivotal for a benign clinical course.

Association between heparan sulfate proteoglycan excretion and proteinuria after renal transplantation.

The aim of the study presented here was to investigate whether, in patients showing immediate graft function after renal transplantation, cold-ischemia and reperfusion lead to damage of the glomerular basement membrane and consequently to a loss of heparan sulfate proteoglycans. Loss of these heparan sulfate proteoglycans is a major cause of proteinuria. Time-dependent changes in urinary excretion rates of heparan sulfate proteoglycans but also of total protein, albumin, low- and high-molecular-weight proteins were analyzed quantitatively and by polyacrylamid-gel-electrophoresis in eight patients. Immediately after renal transplantation, severe proteinuria with an excretion rate of up to 251 +/- 108 mg/min was apparent and rapidly declined within 24 h to 4.11 +/- 2.80 mg/min. The gel-electrophoretic pattern showed a nonselective glomerular and tubular proteinuria. The excretion rate of heparan sulfate proteoglycan was increased in this initial reperfusion phase (up to 7 h), most probably because of ischemia- and reperfusion-induced damage of the glomerular basement membrane. The initial nonselective glomerular proteinuria disappeared within 48 h, changing to a mild selective glomerular proteinuria. In this second phase (7 to 48 h), lower levels of heparan sulfate proteoglycan excretion were observed (0.54 +/- 0.54 microgram/min versus 1.66 +/- 1.93 micrograms/min, P < 0.05). However, during the repair process of the glomerular basement membrane, heparan sulfate proteoglycan is synthesized de novo, leading to an increasing heparan sulfate proteoglycan content of the glomerular basement membrane. This second phase is paralleled by the change from a nonselective to a selective glomerular proteinuria. In the third phase, when the heparan sulfate proteoglycan content of the glomerular basement membrane normalizes, glomerular proteinuria was abolished in most of the patients.

Antineutrophil cytoplasmic antibodies in systemic lupus erythematosus. Prevalence, specificities, and clinical significance.

OBJECTIVE: To examine the prevalence, subspecificities, and clinical associations of antineutrophil cytoplasmic antibodies (ANCA) in patients with systemic lupus erythematosus (SLE). METHODS: One hundred fifty-seven sera from 120 patients with SLE were examined for classic (c) and perinuclear (p) pattern ANCA by indirect immunofluorescence. Antibody subspecificities were determined by enzyme-linked immunosorbent assay (ELISA). Serologic results were correlated with clinical manifestations as categorized by the BILAG (British Isles Lupus Assessment Group) index. RESULTS: ANCA were found in 40 of the 157 sera (25%). Only a pANCA, not a cANCA, pattern of fluorescence was seen. By ELISA testing, 16 sera reacted to lactoferrin, 8 to elastase, and 4 to lysozyme. There was no reactivity to proteinase 3 (PR3) or myeloperoxidase (MPO). No correlation of pANCA, or any of the ANCA subspecificities, with organ system involvement, as categorized by the BILAG index, was found. Notably, there was no correlation of ANCA results with lupus vasculitis. CONCLUSION: The absence of cANCA, anti-PR3, and anti-MPO shows that with appropriate assay conditions, ANCA testing assists in the differentiation between SLE and the ANCA-associated vasculitides. The lack of a correlation between pANCA or any ANCA subspecificity and clinical manifestations suggests that ANCA do not identify particular clinical subsets among SLE patients, including those with lupus vasculitis.

Detection of circulating adhesion molecules ICAM-1, VCAM-1 and E-selectin in Wegener's granulomatosis, systemic lupus erythematosus and chronic renal failure.

The adhesion molecules ICAM-1, VCAM-1 and E-Selectin are regulated by proinflammatory cytokines and play an important role in the binding and activation of leukocytes in inflammatory diseases. This study measured the serum concentrations of circulating adhesion molecules (cICAM-1, cVCAM-1, cE-Selectin) by sandwich ELISA in systemic vasculitis with renal involvement (Wegener's granulomatosis WG, n = 25; systemic lupus erythematosus SLE, n = 50) in comparison to chronic glomerulonephritis (n = 10), stable renal allograft function and end-stage renal disease (CAPD/hemodialysis, each n = 10). Both cICAM-1 and cVCAM-1 levels, but not cE-Selectin, were significantly increased (p < 0.001) in active WG compared to healthy controls. cICAM-1, not cVCAM-1 differed significantly between active and inactive WG. Only cVCAM-1 was significantly elevated in active/inactive SLE (p < 0.01). WG with rapidly progressive glomerulonephritis had significantly raised levels of cICAM-1 and cVCAM-1, but not cE-Selectin, compared to controls (p < 0.005). In lupus nephritis only cVCAM-1 was significantly elevated (p < 0.01). cICAM-1 and cVCAM-1 levels were significantly raised in WG patients, that were hemodialysed and in patients with hemodialysis because of different reasons when compared to controls. However, cVCAM-1 but not cICAM-1 was significantly higher in WG with HD than without HD. Patients with chronic glomerulonephritis, renal allografts or CAPD also had significantly raised cVCAM-1 concentrations. These data suggest, that levels of circulating adhesion molecules might reflect different pathophysiologic processes in systemic vasculitides and endothelial/immune activation in non-inflammatory renal diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased glomerular basement membrane heparan sulfate proteoglycan in essential hypertension.

Heparan sulfate proteoglycans are major components of the glomerular basement membrane and play a key role in the molecular organization and function of the basement membrane. Moreover, their presence is essential for maintenance of the selective permeability of the glomerular basement membrane. Recently, we isolated and characterized a novel small basement membrane-associated heparan sulfate proteoglycan from human aorta and kidney. Partial amino acid sequence data clearly show that this heparan sulfate proteoglycan is distinct from the large basement membrane-associated heparan sulfate proteoglycan (perlecan). Using specific monoclonal antibodies, we have shown that the novel heparan sulfate proteoglycan is located predominantly in the glomerular basement membrane and, to a lesser extent, in the basement membrane of tubuli. Turnover or, in the course of kidney diseases, degradation of heparan sulfate proteoglycan from glomerular basement membranes may lead to urinary excretion of heparan sulfate proteoglycan, which can be measured by a sensitive enzyme immunoassay. The aim of the present study was to analyze whether changes in the structure and function of glomerular basement membranes can be directly detected by measurement of the excretion of a component of this basement membrane, eg, heparan sulfate proteoglycan into urine. The excretion of this small heparan sulfate proteoglycan was compared after physical exercise in normotensive and hypertensive subjects. Normotensive subjects and treated, essential hypertensive patients underwent a standardized workload on a bicycle ergometer. Biochemical characterization of the urinary proteins and heparan sulfate proteoglycan was performed before and 15 and 45 minutes after exercises.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of the granulocyte serine proteinases proteinase 3 and elastase in human glomerulonephritis.

The serine proteinases proteinase 3 (PR3) and elastase are target antigens of antineutrophil cytoplasmic autoantibodies (ANCAs), which are found in various systemic vasculitides with rapidly progressive glomerulonephritis (RPGN). The expression of both proteinases was studied immunohistologically (avidin-biotin complex method) with murine monoclonal antibodies against PR3 (WGM2) and elastase (NP 57) in 122 human renal biopsy specimens to investigate their role in mediating renal damage. Expression of PR3 predominated in ANCA-associated RPGN and was independent of the serologic ANCA pattern (c-/p-ANCA). The PR3 staining pattern was patchy and not always related to distint granulocytes due to antigen spreading by disintegrating cells. It was found in crescentic glomeruli and the interstitum of ANCA-positive RPGN. In contrast, glomerular and interstitial elastase staining pattern was much more granulocyte related and was even found in noncrescentic glomeruli in c-ANCA- and p-ANCA-positive pauci-immune RPGN. Endothelial cell and glomerular basement membrane-bound PR3 or elastase expression were not observed. A faint glomerular PR3/elastase expression was seen in Goodpasture's syndrome and within the interstitium in crescentic mesangioproliferative glomerulonephritis (granulocyte related). Both serine proteinases were found in the glomeruli in ANCA-negative acute postinfectious glomerulonephritis. In conclusion, this study provides evidence, for the first time, for the implication of the granulocyte serine proteinases PR3 and elastase in mediating pauci-immune ANCA-positive RPGN and different forms of proliferative glomerulonephritis. The expression of ANCA antigens in ANCA-negative glomerulonephritis suggests that this finding is a marker of neutrophil activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Circulating adhesion molecules ICAM-1, VCAM-1 and E-selectin in systemic vasculitis: marked differences between Wegener's granulomatosis and systemic lupus erythematosus.

Inflammatory systemic disorders with renal tissue damage require the adherence of polymorphonuclear leukocytes to the endothelium, which is mediated by cell surface adhesion molecules. This study measured the serum concentrations of circulating adhesion molecules [intercellular adhesion molecule 1 (cICAM-1), vascular cell adhesion molecule 1 (cVCAM-1), cE-selectin] by sandwich enzyme-linked immunosorbent assay in Wegener's granulomatosis (n = 25) and systemic lupus erythematosus (n = 50). Active Wegener's granulomatosis with cellular crescent formation was associated with significantly raised cICAM-1 levels, an elevated histological activity index, and a high rate of hemodialysis in comparison to Wegener's granulomatosis with fibrocellular crescents or lupus nephritis. The activity index and cICAM-1 levels can be used as parameters to predict renal outcome in Wegener's granulomatosis. cVCAM-1 levels in Wegener's granulomatosis were significantly higher in patients with hemodialysis compared to those without hemodialysis. In lupus nephritis only cVCAM-1, not cICAM-1 or cE-selectin, were significantly higher (P < 0.01) than controls. cVCAM-1 levels in both diseases were significantly higher than in controls. Only in Wegener's granulomatosis did cICAM-1 and cVCAM-1 levels decrease with clinical remission; in systemic lupus erythematosus the levels remained unchanged. cE-selectin levels were not significantly elevated in systemic vasculitis or collagen disease although individual patients revealed high serum concentrations. These data suggest that levels of circulating adhesion molecules reflect different pathophysiological processes in systemic vasculitis and collagen disease and may be used as markers of disease activity and renal outcome.

Prevention of the acute graft-versus-host disease (GVHD) in rats by the immunomodulating drug leflunomide.

The grafting of immunocompetent allogeneic cells into MHC-discordant, genetically nonresponsive F1 hybrids of inbred rat strains consistently leads to an acute, lethal graft-versus-host disease (GVHD). The novel immunomodulating drug leflunomide, which has been shown to be efficacious in animal models of autoimmunity and adverse transplantation reactions, was studied in a rat model of GVHD. It was found that this drug not only was a powerful agent to prevent this otherwise terminal disorder, but was also proficient when used as a therapy of an established GVHD. Since leflunomide has been shown to be efficacious and safe in patients with chronic rheumatoid arthritis, it would also be reasonable to investigate this drug in clinical trials for bone marrow transplantation and GVHD in human beings.

[Acute segmental hemorrhagic penicillin-associated colitis]. / Akute segmentale hämorrhagische Penicillin-assoziierte Kolitis.

Four days after beginning a perioperative antibiotic prophylaxis with amoxicillin and clavulanic acid a 33-year-old patient developed an acute haemorrhagic diarrhoea with cramp-like lower abdominal pain. Coloscopy revealed diffuse mucosal oedema with map-like ulcerations, increased susceptibility to trauma and submucous haemorrhages extending from the middle of the ascending to the middle of the descending colon. Granulocytic inflammation with cryptal atrophy was seen histologically. Stool cultures, including tests for Clostridium difficile toxin, were normal. All symptoms disappeared within three days of discontinuing the medication. Coloscopy after one week revealed marked improvement, after three months nothing abnormal. Acute segmental haemorrhagic penicillin-associated colitis is rare and must be distinguished from antibiotic-associated pseudomembranous colitis.

[Clinical significance of intrinsic sympathomimetic activity of the beta blocker carteolol. II: Comparative studies of carteolol and pindolol in patients with bradycardia]. / Klinische Bedeutung der ISA des Betablockers Carteolol. Teil II: Vergleichende Untersuchungen von Carteolol und Pindolol bei Patienten mit Bradykardie.

Completing previous studies in patients with sinus bradycardia (Med. Klin. 82 [1987], 647-650) we compared metoprolol with carteolol and pindolol, pindolol with carteolol, no treatment with carteolol (in two groups) in five series of the paired comparisons of Holter-ECG each. With change from metoprolol to carteolol or pindolol (dose ratio 10:1) lowest heart rate on Holter-ECG increased by 28 or 29% without change of exercise heart rate. Direct comparison of pindolol and carteolol revealed a very similar heart rate profile, indicating equipotent beta blockade and ISA. In patients with previous beta blocker induced bradycardia, carteolol did not change a normal resting heart rate off treatment. However, in patients with spontaneous sinus bradycardia carteolol increased lowest heart rate (+14%, due to overriding ISA) and lowered exercise heart rate (-15%, due to overriding beta blockade). A beta blocker induced sinus bradycardia consistently improved with change of treatment to carteolol and pindolol. With caution carteolol and pindolol may also be used despite spontaneous sinus bradycardia.

[Familial Mycoplasma pneumonia. The varied picture of pulmonary and extrapulmonary manifestations]. / Familiäre Mykoplasmenpneumonie. Das bunte Bild pulmonaler und extrapulmonaler Manifestationen.

Mother, father (26 y.o.) and their only child (5 y.o.) developed nonproductive cough, fever (39.5 to 40.4 degrees C) and bilateral pulmonary infiltrates within three weeks. In addition the mother developed a small left pleural effusion and a pericardial effusion, a relative bradycardia, a pruritic vesicular exanthem of the extremities and the trunk, an erythema nodosum and arthritis of the tarsal joints. The father's coulter counter red blood count was distorted by microagglutination at room temperature (hemoglobin 13.2 gr/dl; erythrocytes 1,91 X 10(6) mm-3 and MCH 69.1 pg; MCV 120 fl and hematocrit 23.8%) but not at 37 degrees C (13.2; 4.15 and 31.8; 92 and 39.3, respectively). In the daughter myringitis, pharyngitis, cervical lymphadenopathy and splenomegaly were observed. Cold agglutinins and serologic evidence for mycoplasma pneumoniae infection were demonstrable in all three. Treatment with Tetracycline (parents) and Erythromycin (child) was effective.