Clinical presentations and molecular basis of complement C1r deficiency in a male African-American patient with systemic lupus erythematosus.

Homozygous deficiencies of early components for complement activation are among the strongest genetic risk factors for human systemic lupus erythematosus (SLE). Eleven cases of C1r deficiency are documented but this is the first report on the molecular basis of C1r deficiency. The proband is an African-American male who developed SLE at 3 months of age. He had a discoid lupus rash and diffuse proliferative glomerulonephritis. Serum complement analysis of the patient showed zero CH50 activity, undetectable C1r, and reduced levels of C1s, but highly elevated levels of complement C4, C2, and C1-inhibitor. The coding regions of the mutant C1R gene with 11 exons located at chromosome 12p13 were polymerase chain reaction (PCR)-amplified and sequenced to completion. DNA sequencing revealed a homozygous C→T mutation at nucleotide-6392 in exon 10 of the C1R gene, resulting in a nonsense mutation from Arg-380 (R380X). The patient's clinically normal mother was heterozygous for this mutation. A sequence-specific primer (SSP) PCR coupled with StuI-restriction fragment length polymorphism (RFLP) was developed to detect the novel mutation. Screening of 209 African-American SLE patients suggested that the R380X mutation is a rare causal variant. Mutations leading to early complement component deficiencies in SLE are mostly private variants with large effects.

Expression of the Wnt inhibitor Dickkopf-1 is required for the induction of neural markers in mouse embryonic stem cells differentiating in response to retinoic acid.

Cultured mouse D3 embryonic stem (ES) cells differentiating into embryoid bodies (EBs) expressed several Wnt isoforms, nearly all isotypes of the Wnt receptor Frizzled and the Wnt/Dickkopf (Dkk) co-receptor low-density lipoprotein receptor-related protein (LRP) type 5. A 4-day treatment with retinoic acid (RA), which promoted neural differentiation of EBs, substantially increased the expression of the Wnt antagonist Dkk-1, and induced the synthesis of the Wnt/Dkk-1 co-receptor LRP6. Recombinant Dkk-1 applied to EBs behaved like RA in inducing the expression of the neural markers nestin and distal-less homeobox gene (Dlx-2). Recombinant Dkk-1 was able to inhibit the Wnt pathway, as shown by a reduction in nuclear beta-catenin levels. Remarkably, the antisense- or small interfering RNA-induced knockdown of Dkk-1 largely reduced the expression of Dlx-2, and the neuronal marker beta-III tubulin in EBs exposed to RA. These data suggest that induction of Dkk-1 and the ensuing inhibition of the canonical Wnt pathway is required for neural differentiation of ES cells.

Concomitant inhibition of Janus kinase 3 and calcineurin-dependent signaling pathways synergistically prolongs the survival of rat heart allografts.

The cytoplasmic localized Janus tyrosine kinase 3 (Jak3) is activated by multiple cytokines, including IL-2, IL-4, and IL-7, through engagement of the IL-2R common gamma-chain. Genetic inactivation of Jak3 is manifested as SCID in humans and mice. These findings have suggested that Jak3 represents a pharmacological target to control certain lymphoid-derived diseases. Using the rat T cell line Nb2-11c, we document that tyrphostin AG-490 blocked in vitro IL-2-induced cell proliferation (IC(50) approximately 20 microM), Jak3 autophosphorylation, and activation of its key substrates, Stat5a and Stat5b, as measured by tyrosine/serine phosphorylation analysis and DNA-binding experiments. To test the notion that inhibition of Jak3 provides immunosuppressive potential, a 7-day course of i.v. therapy with 5-20 mg/kg AG-490 was used to inhibit rejection of heterotopically transplanted Lewis (RT1(l)) heart allografts in ACI (RT1(a)) recipients. In this study, we report that AG-490 significantly prolonged allograft survival, but also acted synergistically when used in combination with the signal 1 inhibitor cyclosporin A, but not the signal 3 inhibitor, rapamycin. Finally, AG-490 treatment reduced graft infiltration of mononuclear cells and Stat5a/b DNA binding of ex vivo IL-2-stimulated graft infiltrating of mononuclear cells, but failed to affect IL2R alpha expression, as judged by RNase protection assays. Thus, inhibition of Jak3 prolongs allograft survival and also potentiates the immunosuppressive effects of cyclosporin A, but not rapamycin.

Changing patterns in the histopathology of idiopathic nephrotic syndrome in children.

BACKGROUND: It is widely accepted that minimal change nephrotic syndrome (MCNS) is the most common cause of nephrosis in children. Recent studies have demonstrated an increasing incidence of focal segmental glomerulosclerosis (FSGS) in adults. METHODS: To determine possible changes in the etiology of childhood nephrosis, the clinical charts of 152 pediatric patients diagnosed with idiopathic nephrotic syndrome between 1978 and 1997 were reviewed. Histopathological diagnosis was available in 105 patients. RESULTS: MCNS was present in 35% of all biopsies, whereas FSGS was observed in 31%. Even if we assume that all patients without a histological diagnosis had MCNS (presumptive MCNS), the total incidence of MCNS (biopsy proven + presumptive) in our population was only 55%. We observed a dramatic increase in the incidence of FSGS during recent years. Before 1990, FSGS was diagnosed in 23% of all renal biopsies but increased to 47% afterward (P = 0.02). This pattern was observed in all ethnic groups. In African Americans, there was a trend for an increase in the incidence of FSGS from 38% before 1990 to 69% after 1990. A similar trend was observed in Caucasians (from 20 to 45%) and Hispanics (from 8 to 33%) Hispanics had the highest incidence of MCNS (biopsy proven + presumptive: 73%), followed by Caucasians (53%) and African Americans (37%). The mean age for presentation of nephrotic syndrome in African Americans (8.0 +/- 0.9 years) was higher than in Caucasians (4.1 +/- 0.05) and Hispanics (3.3 +/- 0.5). CONCLUSIONS: Our study showed that the incidence of FSGS in children with idiopathic nephrotic syndrome has increased recently. Furthermore, in African American children. FSGS is the most common cause of nephrotic syndrome. These findings may have significant implications in the management of childhood nephrotic syndrome.

Image analysis of proliferating cell nuclear antigen expression and immunohistochemical profiles in renal cell carcinoma associated with acquired cystic kidney disease: comparison with classic renal cell carcinoma.

Renal cell carcinoma (RCC) arising in acquired cystic kidney disease (ACKD) is considered to be a tumor of low malignant potential, compared with classic RCC. The aim of the present study was to identify any significant differences in the antigenic profiles or tumor cell proliferative activity of ACKD-associated RCC and classic RCC that might be responsible for differences in their biologic behavior. We studied the immunohistochemical profiles and proliferative activity of 12 classic RCCs and 5 ACKD-associated RCCs with markers of proximal tubules (Leu M1, alpha-1 antitrypsin, CAM 5.2), markers of distal tubules (Arachis hypogaea lectin, AE1/AE3, epithelial membrane antigen [EMAJ, CAM 5.2), vimentin, and proliferating cell nuclear antigen (PCNA). We performed proliferation analysis with the CAS 200 image analysis system. For each case, 8 to 20 fields of tumor tissue in the areas of maximal PCNA staining were quantitated, and the percentage of PCNA-positive nuclear area for each individual tumor was calculated. All of the five ACKD-associated RCCs expressed AE1/AE3, EMA, and CAM 5.2 in more than 50% of the tumor cells. Arachis hypogaea lectin was significantly expressed in three of the five ACKD-associated RCCs. Leu M1 and alpha-1 antitrypsin reacted with fewer than 10% of the tumor cells in all of the five ACKD-associated RCCs. In contrast, the 12 classic RCCs showed expression of CAM 5.2 in 11 cases, alpha-1 antitrypsin in 10 cases, Leu M1 in 9, EMA in 8, and AE1/AE3 in 3 cases in more than 50% of the tumor cells and a totally negative reaction with Arachis hypogaea lectin in 8 cases, EMA in 4, AE1/AE3 in 4, and vimentin in 5 cases. Although coexpression of proximal and distal tubule markers was seen in some cases of RCC in either category, there was uniform and strong staining for distal tubule markers in ACKD-associated RCC and for proximal tubule markers in classic RCC. The mean percentage of PCNA-positive nuclear area for the ACKD-associated RCCs (2.41%) was significantly (P < .05) less than that of the classic RCCs (21.42%). The differences in expression of proximal and distal tubule markers and proliferative activity might be responsible for the differences in the biologic behavior of ACKD-associated RCC and classic RCC.

Role of neutrophils and macrophages in experimental nephrosis of the rat.

The single dose administration of the aminonucleoside of puromycin (PAN) induces a nephrotic syndrome in rats characterized by massive proteinuria and progressive histologic changes. This model of acute parenchymal nephritis is thought to be mediated by the renal recruitment of monocytes and macrophages. To investigate the role of leukocytes in the experimental nephrotic syndrome model, the effects of two methylxanthines, pentoxifylline (45 mg/kg i.p. twice daily) and torbafylline (5 mg/kg i.p. twice daily) were compared with controls over a 2-week period. Pentoxifylline treatment was associated with 3- and 6-fold reductions in urinary protein excretion at 7 and 14 days, respectively, compared with PAN-treated control animals (p < .01). Similarly, 14-day dosing of torbafylline resulted in a 3-fold decrease in urinary protein excretion. Glomerular filtration and electrolyte excretion rates were similar between all treatment groups. There were significant reductions in glomerular neutrophil and macro-phage counts, but not T-cells (OX19+) or suppressor/cytotoxic T-cells (0X8+), in kidneys of rats given either treatment compared with PAN con-trol rats. In summary, both pentoxifylline and torbafylline attenuated the proteinuria and glomerular macrophage and neutrophil infiltration associated with PAN administration. These data support the role of macrophages and neutrophils in the pathogenesis of acute parenchymal injury and the potential role of pentoxifylline or related analogues in the attenuation of the ensuing renal deficit associated with minimal lesion disease.

Tenascin is an ubiquitous extracellular matrix protein of human renal interstitium in normal and pathologic conditions.

Tenascin, a large oligomeric glycoprotein, is a recent addition to a list of increasing extracellular matrix proteins. Previous studies have documented the strong expression of tenascin in embryonic kidney and in both normal and abnormal mature glomeruli implicating an important role of this extracellular matrix protein in nephrogenesis and glomerular scarring. Whether tenascin plays any role in interstitial fibrosis, a common final pathway of tubulointerstitial nephritis, is no known; on the other hand, a detailed knowledge of the structural components of interstitial fibrosis is essential for further studies on other fundamental aspects of this biologically and clinically important process. In this study, the expression of tenascin in the renal interstitium was immunohistochemically evaluated in 208 renal specimens during normal kidney (23 cases), acute tubular necrosis (8), acute tubulointerstitial nephritis (8), chronic primary tubulointerstitial nephritis (30), tubulointerstitial nephritis secondary to glomerular diseases of mild (46) and severe (55) degree, ischemic damage (24), and rejection (14). It was found that in normal kidney tenascin expression was limited to the medullary interstitium. In kidney with tubulointerstitial nephritis, tenascin was ubiquitously and constantly expressed in any areas with tubulointerstitial damage regardless of diagnosis, etiology, the cortical vs. medullary location of the lesions, stage of the fibrogenetic process, density of fibroblasts, or severity of interstitial inflammation in the affected areas. Indeed, strong tenascin expression was seen in areas where there was only interstitial edema or inflammation as judged by routine light microscopic preparations. In summary, this study systematically documents tenascin as a novel extracellular matrix protein selectively expressed in the medullary interstitium in normal kidney, and ubiquitously present in areas with interstitial fibrosis.

Nephrotic syndrome related to systemic lupus erythematosus after griseofulvin therapy.

We report a 16-year-old male who developed nephrotic syndrome related to membranous glomerulopathy with clinical and serological evidence of systemic lupus erythematosus after treatment with griseofulvin. To our knowledge, this is the first case of griseofulvin-exacerbated lupus in which nephrotic syndrome has been observed.

[Transurethral resection of the prostate: when?]. / La resezione transuretrale della prostata: quando?

Over a period of 5 years (from 1989 to 1993) 410 patients with benign prostatic hypertrophy (BPH) were treated by transurethral resection of the prostate (TURP). A retrospective study was conducted by the Authors to evaluate indications, surgical approaches and results. The Authors' experience is compared with literature reports.

Evaluation of chronic renal disease in heart transplant recipients: importance of pretransplantation native kidney histologic evaluation.

Although long-term use of cyclosporine has been implicated in the pathogenesis of arteriolar hyalinosis, interstitial fibrosis, and glomerulosclerosis observed in the native kidneys of heart transplant recipients, it is not clear that these histologic abnormalities are entirely specific for a drug-induced toxic nephropathy. The purpose of this study was to determine whether long-standing congestive heart failure, particularly when complicated by disease processes such as atherosclerosis and hypertension, may independently predispose to the development of similar renal histopathology. Records and specimens were selected from autopsy files for evaluation of clinical profiles and kidney histology in 16 patients who died of end-stage cardiomyopathy of varying causes without having recourse to heart transplantation. The study cohort consisted of 12 men and four women. Cardiomyopathies were the result of coronary artery disease in six patients and nonischemic causes in the other 10 patients. The mean age at the time of death was 53 +/- 3 years (range 28 to 74 years). Thirteen (81%) of 16 patients had a history of hypertension. Nadir serum creatinine concentrations during the month before death were 1.7 +/- 0.2 mg/dl (range 1.2 to 3.5 mg/dl). Interstitial fibrosis, tubular atrophy, and glomerulosclerosis were present in 15 (94%) of 16 patients. Arteriosclerosis and arteriolosclerosis were found in 13 (81%) of 16 and 14 (88%) of 16 patients, respectively. A nodular pattern of arteriolar hyalinosis was observed in two patients with ischemic disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracytoplasmic lumina in a case of bilaterally multifocal renal oncocytomas.

We report a case of bilaterally multifocal renal oncocytomas in a patient with chronic renal disease and a long history of hypertension. Histologic study of the multiple oncocytic neoplasms with hematoxylin-eosin, periodic acid-Schiff, trichrome, and colloidal iron stains revealed novel, intracytoplasmic lumina, which were accentuated by immunoperoxidase staining with high-molecular-weight cytokeratin, epithelial membrane antigen, and Arachis hypogaea lectin. Ultrastructural studies demonstrated multiple microvilli lining the intracytoplasmic lumina. We also review the literature on bilaterally multifocal oncocytomas.

Effect of atrial natriuretic peptide on urine flow and glomerular filtration during acute renal allograft rejection.

The effect of exogenous atrial natriuretic peptide (ANP) on urine excretion and glomerular filtration rate (GFR) during acute renal allograft rejection was evaluated in a canine model. Eight animals underwent simultaneous allotransplantation and unilateral native nephrectomy. No preoperative or postoperative immunosuppressive therapy was given. Acute renal function studies were performed on the allografts and companion, native kidneys following surgical exposure and mobilization on the third postoperative day. At reexploration, the allografts were found to be grossly enlarged (138 +/- 10 gm.) and contained moderate-to-marked perivascular interstitial infiltration. Glomerular filtration rate, determined by measurement of urinary inulin clearance, was significantly reduced from prenephrectomy baseline values (19 +/- 4 ml. per minute versus 32 +/- 5 ml. per minute, p < .05). During a 30 minute, intravenous ANP infusion, allograft urine flow rates increased from 1.4 +/- 0.5 ml. per minute to 3.3 +/- 0.4 ml. per minute (p < .01), and GFR increased from 19 +/- 4 ml. per minute to 24 +/- 4 ml. per minute (p < .05). During ANP infusion, mean arterial pressure declined from 136 +/- 7 mm. Hg to 116 +/- 7 mm. Hg (p < .05), and the hematocrit remained unchanged. These observations are consistent with previously described, ameliorative effects of ANP in other models of acute ischemic renal injury and provide an experimental basis for more extended studies examining the potential usefulness of ANP as adjunctive therapy in the treatment of acute renal allograft rejection.

Congenital mesoblastic nephroma: an immunohistochemical and lectin study.

Eight cases of congenital mesoblastic nephroma (CMN) were examined. Three CMNs were of the classical (typical) variant, two were cellular (atypical), and three showed a mixed pattern. A panel of nephron segment-specific tubular epithelial markers (the lectins Tetragonolobus purpureas, Phaseolus vulgaris erythroagglutinin, and Arachis hypogaea and antibodies to epithelial membrane antigen, cytokeratin, and Tamm-Horsfall protein) were used to differentiate epithelial structures within the tumor. Antibodies against vimentin, desmin, and muscle-specific actin were used as mesenchymal markers. A monoclonal antibody to the long (embryonic) form of polysialic acid (PSA) on the neural cell adhesion molecule was used as a putative renal oncodevelopmental marker. An antibody to proliferating cell nuclear antigen also was applied, which revealed increased proliferative rate in cellular CMNs. In addition to clearly entrapped native renal tubules, CMNs contain tubular structures with immature, dysplastic epithelium and occasional epithelial cell clusters embedded deep within the tumor. These immature tubules and clusters express distal nephron, including collecting duct markers and, occasionally, vimentin and PSA. We propose that these primitive tubules and epithelial structures may originate from the ureteric bud. An epithelial differentiation of the tumor cells also is possible. In one pure cellular CMN and two mixed CMNs the cellular component showed diffuse staining for PSA. The PSA (neural cell adhesion molecule) expression of the cellular component suggests that CMN may originate from the uninduced nephrogenic mesenchyme.

Obesity-associated focal segmental glomerulosclerosis: pathological features of the lesion and relationship with cardiomegaly and hyperlipidemia.

In a review of the autopsies and medical records of 22 obese patients, focal segmental glomerulosclerosis (FSGS) was present in seven. The FSGS was mild in all but one patient. The FSGS of obese patients has similar features to idiopathic FSGS; however, our findings suggest that it lacks the hyperplasia of glomerular epithelial cells, shows no predilection for the corticomedullary junction, and is probably more often seen in the hilar region of the glomeruli. FSGS or glomerulomegaly was not associated with the degree of obesity. We demonstrated lipid deposition in the kidney of obese patients. Obese patients with FSGS, compared to those without FSGS, had higher blood cholesterol (P < 0.10) and higher triglyceride levels (P < 0.01). The mean heart weight of obese patients with FSGS was greater than that of patients without FSGS (P < 0.01). Also, obese patients with FSGS had larger glomeruli (246 +/- 33 microns) than obese patients without FSGS (218 +/- 16 microns) (P < 0.05). These findings suggest that cardiomegaly with hemodynamic changes and glomerular hyperfiltration may play a significant role in the glomerulomegaly and FSGS of obese patients. The secondary or contributory role of lipids in the development of the FSGS of obese patients remains to be determined.

Sickle cell glomerulopathy with focal segmental glomerulosclerosis.

Sickle cell disease is known to cause glomerulopathy, including focal segmental glomerulosclerosis (FSGS). Patients who have sickle cell glomerulopathy with FSGS are thought to have a poorer prognosis than patients who have sickle cell glomerulopathy without this lesion. The former patients are more likely to have persistent proteinuria and eventually develop end-stage renal disease. We present a boy with sickle cell glomerulopathy and FSGS who is younger than patients with similar findings reported previously. The histopathology of his renal lesions is remarkable for segmental ultrastructural changes in the glomerular basement membranes and endothelial cells. We speculate that these changes are precursory to the pathogenesis of glomerular sclerosis in patients with sickle cell disease.

Attenuation of amphotericin-B nephrotoxicity in the candidiasis rat model.

Dose-limiting nephrotoxicity has hampered the clinical usefulness of amphotericin-B (AmpB). Recently, vascular decongestants, such as pentoxifylline, have shown benefit in reducing drug-associated renal damage of AmpB in rats. The present study investigated a dose-dependent protection of a structurally similar methylxanthine, HWA-448, in the candidiasis rat model given a single dose of AmpB. Forty-eight hours after inoculation with Candida albicans, each rat was treated with 0.8 mg/kg of AmpB or sterile water; animals were further randomized to receive 0.5, 1, 5, or 10 mg/kg i.v. of HWA-448 or saline given every 12 h for 3 doses. Kidney fungal counts, morphology, and renal function were compared between treatment groups upon completion of the study. Rats administered AmpB with HWA-448 had markedly improved renal function compared with those given AmpB alone; these effects were independent of the administered dose of HWA-448. The antifungal effect of AmpB was not impaired with concomitant HWA-448. Marked accumulation of granulomas and organisms was found in all rat groups. In summary, coadministration of low doses of HWA-448 attenuated the dose-limiting nephrotoxicity without impairing the antifungal effect of AmpB.

Benefit of vascular decongestion in glycerol-induced acute renal failure.

The post insult administration of vascular decongestants has resulted in attenuation of experimental acute renal failure (ARF) following the introduction of various nephrotoxins including drugs, heavy metals, and endotoxin. In the present study, the dose-dependent effects of a novel methylxanthine, HWA-138, were studied in the glycerol-induced murine model of ARF. Renal function, assessed by serial inulin clearances at 24 and 48 h after glycerol injection, urinary electrolyte excretion rates, and renal morphology, was compared between controls and those given glycerol and single i.v. doses of 0.1, 0.5, 1.0, 5.0, and 10.0 mg/kg of HWA-138, or physiologic saline. Whereas significant renal dysfunction was found in all animal groups given glycerol, the mean inulin clearance values of animals given HWA-138 1 mg/kg closely approximated values found in control rats. There were no changes in renal electrolyte excretion rates in animals given HWA-138 compared with relative natriuresis found in untreated glycerol ARF rat. Although a modest decrease in medullary congestion was associated with rats given 1 mg/kg of HWA-138, there was no obvious structural improvement found with HWA-138. The present data provide further evidence of the potential of methylxanthines in the glycerol-ARF murine model.

Esophageal adenocarcinoma in a patient with surgically treated achalasia.

Although squamous cell carcinoma of the esophagus occurs with increased incidence in primary achalasia, esophageal adenocarcinoma has been considered rare in this condition. We report a patient with long-standing achalasia in whom adenocarcinoma of the esophagus occurred many years after Heller esophagomyotomy, presumably related to Barrett's esophagus complicating gastro-esophageal reflux disease.