Mutational analysis of <Emphasis Type="Italic">NPHS2</Emphasis> and <Emphasis Type="Italic">WT1</Emphasis> in frequently relapsing and steroid-dependent nephrotic syndrome

Idiopathic nephrotic syndrome is a common pediatric kidney disease, 80% of all cases are steroid sensitive (SSNS). A significant proportion of children with SSNS will have a frequently relapsing or steroid-dependent course (FRNS/SDNS) that is associated with significant treatment-related morbidity. Mutations in NPHS2 account for more than 28% of all cases of steroid-resistant nephrotic syndrome (SRNS) and dominant mutations in WT1 for 5%; while mutations are absent from children with uncomplicated SSNS. Since FRNS/SDNS is phenotypically positioned within a spectrum between SSNS and SRNS, we hypothesized that heterozygous mutations of NPHS2 may be causing FRNS/SDNS. Mutational analysis of NPHS2 and WT1 was carried out in a single-center cohort of 20 children with FRNS/SDNS, ten children with uncomplicated SSNS (control), and 22 children with SRNS (control). Renal biopsy findings were available in 15/20 children with FRNS/SDNS and revealed IgM nephropathy, MCNS, and FSGS in six, five, and four children, respectively. Children with FRNS/SDNS were significantly younger at first presentation than those with SSNS and SRNS (median age: 3.0 years in FRNS/SDNS patients, 7.0 years in SSNS patients, and 5.0 in SRNS patients; p < 0.001). No NPHS2 or WT1 mutations were found in patients with FRNS/SDNS and uncomplicated SSNS. The hypothesis that FRNS/SDNS may be associated with heterozygous mutations in NPHS2 or WT1 was not confirmed.     

<Emphasis Type="Italic">WT1</Emphasis> and <Emphasis Type="Italic">NPHS2</Emphasis> mutations in Korean children with steroid-resistant nephrotic syndrome

Although several genetic causes of steroid-resistant nephrotic syndrome (SRNS) have been identified, occurrence of these genetic abnormalities appears to be influenced by race. Seventy Korean children (39 girls, 31 boys) with SRNS underwent analysis for mutations of WT1 and NPHS2. Although NPHS2 mutations were not present in any of the patients, two different intronic mutations of WT1, IVS9+4 C>T and IVS9+5 G>A, were detected in four patients (three girls, one boy). Among the four patients with mutation, two girls with a karyotype of 46,XY had complete XY gonadal dysgenesis, one girl with a karyotype of 46,XX had normal genitalia, and one boy with a karyotype of 46,XY had hypospadia. A kidney biopsy conducted in three of the four patients revealed focal segmental glomerulosclerosis. The incidence of WT1 mutations observed in this study was similar to that of previous reports. However, the incidence of NPHS2 mutations seems to be very rare in Korean children. Genetic diagnosis of WT1 mutations should be recommended for children with SRNS, especially in cases involving a female phenotype or males with genital anomalies.     

No evidence for genotype/phenotype correlation in<Emphasis Type="Italic"> NPHS1</Emphasis> and<Emphasis Type="Italic"> NPHS2</Emphasis> mutations

Primary steroid-resistant nephrotic syndrome (SRNS) is characterized by childhood onset of proteinuria and progression to end-stage renal disease. In 26% of cases it is caused by recessive mutations in NPHS2 (podocin). Congenital nephrotic syndrome (CNS) is caused by mutations in NPHS1 (nephrin) or NPHS2. In three families mutations in NPHS1 and NPHS2 had been reported to occur together, and these tri-allelic mutations were implicated in genotype/phenotype correlations. To further test the hypothesis of tri-allelism, we examined a group of 62 unrelated patients for NPHS1 mutations, who were previously shown to have NPHS2 mutations; 15 of 62 patients had CNS. In addition, 12 CNS patients without NPHS2 mutation were examined for NPHS1 mutations. Mutational analysis yielded three different groups. (1) In 48 patients with two recessive NPHS2 mutations (11 with CNS), no NPHS1 mutation was detected, except for 1 patient, who had one NPHS1 mutation only. This patient was indistinguishable clinically and did not have CNS. (2) In 14 patients with one NPHS2 mutation only (4 with CNS), we detected two additional recessive NPHS1 mutations in the 4 patients with CNS. They all carried the R229Q variant of NPHS2. The CNS phenotype may be sufficiently explained by the presence of two NPHS1 mutations. (3) In 12 patients without NPHS2 mutation (all with CNS), we detected two recessive NPHS1 mutations in 11 patients, explaining their CNS phenotype. We report ten novel mutations in the nephrin gene. Our data do not suggest any genotype/phenotype correlation in the 5 patients with mutations in both the NPHS1 and the NPHS2 genes.Members of the Study Group of the Arbeitsgemeinschaft für Pädiatrische Nephrologie (APN) participating in this study: J. Thaarup (Aalborg, Denmark); P. Henning (Adelaide, Australia); I. Attrach (Aleppo, Syria); A. Bakkaloglu (Ankara, Turkey); C. Rudin (Basel, Switzerland); R. Bogdanovic (Belgrade, Yugoslavia); S. Briese, J. Gellermann, T. Lennert, U. Querfeld, Sacherer, M. Schürmann, and M. Zimmering (Berlin, Germany); C. Roth, C. Schröter, and B. Utsch (Bonn, Germany); Matthes (Bremen, Germany); A. Heilmann and G. Kalvoda (Dresden, Germany); F. Wegner (Düren, Germany); V. Schumacher (Düsseldorf, Germany); Bär, B. Bosch, M. Kamm, S.M. Karle, K. Nüsken, C. Plank, W. Rascher, and B. Zimmermann (Erlangen, Germany); K. E. Bonzel, M. Bald, P. Hoyer, and U. Vester (Essen, Germany); U. Neyer (Feldkirch, Austria); Rippel (Frankfurt, Germany); M. Brandis, A. Fuchshuber, K. Häffner, A. Kirchhoff, and M. Pohl (Freiburg, Germany); J. Steiss (Giessen, Germany); J.P. Haas (Greifswald, Germany); L. Patzer (Halle, Germany); M. Kemper, H. Altrogge, D.E. Müller-Wiefel, U. Peters, and K. Timmermann (Hamburg, Germany); J.H.H. Ehrich, H. Haller, and C. Strehlau (Hannover, Germany); M. Daschner, S. Hessing, Janssen, D. Kiepe, S. Köpf, O. Mehls, and B. Tönshoff (Heidelberg, Germany); F. Prüfer and L.B. Zimmerhackl (Innsbruck, Austria); U. John, J. Misselwitz, G. Rönnefarth, and J. Seidel (Jena, Germany); D. Blowey and J. Scheinman (Kansas City, Mo., USA); B. Beck, K. Frankenbusch, B. Hoppe, C. Licht, D. Michalk, T. Ronda, and L. Stapenhorst (Cologne, Germany); D. Drozdz and A. Pogan (Krakau, Poland); Froster, E. Vogel and S. Wygoda (Leipzig, Germany); R. Hettenger (Los Angeles, Calif., USA); H. Schriewer and H.-P. Weber (Lüdenscheid, Germany); R. Beetz (Mainz, Germany); M. Konrad (Marburg, Germany); H. Fehrenbach (Memmingen, Germany); M. Griebel and B. Klare (München, Germany); M. Bulla, S. Fründ, E. Kuwertz-Bröking, A. Schulze-Everding and Yelbuz (Münster, Germany); L. Monnens (Nijmegen, The Netherlands); J. Janda and T. Seemann (Prag, Czech Republic); G. Adomssent, G. Krüger, Lorenzen, J. Muscheites, H.-J. Stolpe and M. Wigger (Rostock, Germany); W. Sperl (Salzburg, Austria); R. Egger (Schaffhausen, Switzerland); V. Tasic (Skopje, Macedonia); M. Bald and H.-E. Leichter (Stuttgart); O. Amon (Tübingen, Germany); T. Arbeiter, C. Aufricht and K. Müller (Vienna, Austria); D. Bockenhauer and N. Siegel (New Haven, Conn., USA); and T. Neuhaus and A. Staub (Zürich, Switzerland)     

Response to prednisone in relation to <Emphasis Type="Italic">NR3C1</Emphasis> intron B polymorphisms in childhood nephrotic syndrome

The variation in time required to obtain cessation of proteinuria in children with nephrotic syndrome (NS) represents one aspect of the variations shown by these children in response to glucocorticoid (GC) treatment. Polymorphism of the GC receptor gene (NR3C1) has been postulated as one factor that would partially explain differences in both the clinical presentation and the reaction to treatment in GC-treated diseases. We genotyped 118 children diagnosed with NS who initially responded to oral GC treatment [steroid-responsive nephrotic syndrome (SRNS) group] and 136 healthy children for three intron B single nucleotide polymorphisms of NR3C1, namely Bcl I (C/G), rs33389 (C/T) and rs33388 (A/T). In the SRNS group, we performed a three-marker haplotype analysis of NR3C1 in relation to the response to prednisone, represented as time to proteinuria resolution (TPR) as categorical and ordinal variable. Results: The distribution of individual polymorphisms and three-marker haplotypes was similar in healthy children and SRNS patients (all p values >0.05). The GTA haplotype was associated with a higher GC sensitivity, as determined by TPR, and was found to be more prevalent in early (response 7 days) prednisone responders (27.7 vs. 14.5%, hap-score = -2.22, p = 0.05 adjusted for biopsy results). These results are in agreement with those reported earlier on an association of intron B haplotypes with GC sensitivity. The distribution of GC polymorphisms among the residents of north-eastern Poland was also determined.     

Intratumoral Heterogeneity in Microsatellite Alterations in <Emphasis Type="Italic">BRCA1</Emphasis> and <Emphasis Type="Italic">PTEN</Emphasis> Regions in Sporadic Colorectal Cancer

Background: Chromosome regions 17q21 (BRCA1) and 10q23 (PTEN) have been found deleted in colorectal cancer.Methods: We studied the frequency of loss of heterozygosity (LOH) in these 2 regions in 214 patients with only 1 sample per tumor and in 100 patients with several samples per tumor. Three microsatellite markers of each region were used for the LOH test. The polymerase chain reaction product was electrophoresed in 8% polyacrylamide gels, and band intensity was shown by silver staining.Results: The proportions of LOH in the two regions were 38.4% for 17q21 and 30.8% for 10q23 in the group of 214 and were 47.7% for 17q21 and 34.7% for 10q23 in the group of 110434_2003_Article_876. We found a high correlation between the LOH in both regions (P < .001), where 81% of LOH in 10q23 region was matched by concomitant LOH in 17q21. In the group of tumors with several samples (group of 100), 39% and 68% did not present LOH in the 17q21 and 10q23 regions, respectively, in all of their tumor samples. However, in the 20 patients with LOH in both regions in the group of 100 (several samples per tumor), all samples with LOH in 10q23 also had LOH in 17q21, whereas not all samples with LOH in 17q21 had LOH in 10q23.Conclusions: These results show that colorectal cancer is highly heterogeneous, at least for these tumors markers, and suggest a sequential acquisition pattern of these anomalies during tumor growth, in which changes in 17q21 could occur before those in 10q23.     

Absence of mutations in the <Emphasis Type="Italic">HOXA11</Emphasis> and <Emphasis Type="Italic">HOXD11</Emphasis> genes in children with congenital renal malformations

Experimental studies have shown that homeobox genes are essential for the development of the kidney and urinary tract. Hoxa11/Hoxd11 double mutant mice demonstrate renal agenesis or hypoplasia. Since, to our knowledge, these genes have never been examined for alterations in humans with congenital anomalies of the kidney and urinary tract (CAKUT), we investigated whether mutations of HOXA11/HOXD11 genes are associated with non-syndromal congenital renal parenchymal malformations. DNA samples from 26 unrelated children with unilateral renal agenesis (URA), 20 with renal hypodysplasia (RHD) and 13 with multicystic dysplastic kidney (MCDK) were included in the study. Exons 1 and 2 of the HOXA11/HOXD11 genes were amplified individually by polymerase chain reaction (PCR) using 12 unique oligonucleotide primers. Single-strand conformation polymorphism (SSCP) analysis of overlapping polymerase chain reaction products was performed. SSCP analysis revealed no variant band shifts in the samples of the amplified segments of the 59 patients, suggesting lack of either mutation or polymorphisms. Our findings do not support the hypothesis that mutations in the HOXA11/HOXD11 coding regions are involved in the pathogenesis of human non-syndromal congenital renal parenchymal malformations. Further studies are necessary, since other genes known to affect nephrogenesis, as well as genetic and environmental factors, may be involved.     

<Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis>-associated hemolytic uremic syndrome

Streptococcus pneumonia-associated hemolytic uremic syndrome (HUS) (pneumococcal HUS) is an uncommon condition mainly observed in young children. Early recognition is critical, because of the potential to improve morbidity and mortality. In our review we summarize the pathophysiology, clinical features, diagnostic difficulties and management of this potentially under-diagnosed condition.     

<Emphasis Type="Italic">NPHS2</Emphasis> mutation associated with recurrence of proteinuria after transplantation

Mutations in the NPHS2 gene encoding podocin are associated with steroid-resistant nephrotic syndrome (SRNS) in childhood. Patients usually present with focal segmental glomerulosclerosis (FSGS). It is unclear to what extent SRNS due to NPHS2 mutations predisposes to recurrence of proteinuria/FSGS after renal transplantation (RTx). A 4-year-old girl with infantile SRNS was started on peritoneal dialysis because of end-stage renal disease due to FSGS. Mutational screening of the patient and her parents revealed a novel single nucleotide deletion in exon 8 of the NHPS2 gene (948delT), for which the patient was homozygous and her parents confirmed heterozygous asymptomatic carriers. At the age of 4.5 years the patient received a renal graft from her mother. On day 7 after RTx, the patient developed progressive proteinuria (urine protein/creatinine ratio 2.4 g/g), which responded within 1 week to prednisone pulse therapy, an increased cyclosporin A dosage, and ramipril therapy. The patient has maintained stable graft function and no further recurrence of proteinuria has been observed. In conclusion, patients with SRNS due to NPHS2 mutations are not protected from recurrence of proteinuria after RTx. The quick response to increased immunosuppression in our patient suggests an immune-mediated pathomechanism for recurrence of proteinuria.     

Clinical course and <Emphasis Type="Italic">NPHS2</Emphasis> analysis in patients with late steroid-resistant nephrotic syndrome

A small fraction of patients with initial steroid-sensitive nephrotic syndrome (SSNS) develops late steroid resistance, i.e. a lack of remission after 4 weeks of relapse treatment despite previous response to steroids. The pathophysiological basis of late resistance and the long-term prognosis remain obscure. Fourteen out of 360 patients with SSNS who were seen in our department between 1954 and 2005 developed late resistance. Median age at onset of NS was 4 years and median duration of development of late resistance 4.6 months. Histology showed minimal-change (MC) nephropathy in six patients and focal segmental glomerulosclerosis (FSGS) in three patients on initial biopsy and four patients on repeat biopsies. Late resistance was treated with cyclophosphamide in five patients, cyclosporine A in three, and both drugs in one. Eight of these nine patients went into remission. All 14 patients maintained a stable kidney function during their period of observation. NPHS2 mutation analysis in eight patients revealed no pathogenic mutations, suggesting that late resistance is not typically associated with mutations in the NPHS2 gene. With respect to the clinical course, late resistance appears to resemble SSNS and is characterized by a favorable outcome.     

<Emphasis Type="Italic">PIK3CA</Emphasis>, <Emphasis Type="Italic">KRAS</Emphasis>, and <Emphasis Type="Italic">BRAF</Emphasis> mutations in intraductal papillary mucinous neoplasm/carcinoma (IPMN/C) of the pancreas

Background and aims Recent studies have reported high frequencies of somatic mutations in the phosphoinositide-3-kinase catalytic-α (PIK3CA) gene in various human tumors. Three hot-spot mutations in the exons 9 and 20 have been proven to activate the Akt signalling pathway. The Raf/MEK/ERK (mitogen-activated protein kinase) signal transduction is an important mediator of a number of cellular fates including growth, proliferation, and survival. The BRAF gene is activated by oncogenic RAS, leading to cooperative effects in cells responding to growth factor signals. Here we evaluate the mutational status of PIK3CA, KRAS, and BRAF in intraductal papillary mucinous neoplasm/carcinoma (IPMN/IPMNC) of the pancreas. Materials and methods Exons 1, 4, 5, 6, 7, 9, 12, 18, and 20 of PIK3CA, exons 1 of KRAS, and exons 5, 11, and 15 of BRAF were analyzed in 36 IPMN/IPMC and two mucinous cystadenoma specimens by direct genomic DNA sequencing. Results We identified four somatic missense mutations of PIK3CA within the 36 IPMN/IPMC specimens (11%). One of the four mutations, H1047R, has been previously reported to be a hot-spot mutation. Furthermore, we found 17 (47%) KRAS mutations in exon 1 and one missense mutation (2.7%) in exon 15 of BRAF. Conclusion This data is the first report of PIK3CA mutation in pancreatic cancer and it appears to be the first oncogene to be mutated in IPMN/IPMC but not in conventional ductal adenocarcinoma of the pancreas. Our data provide evidence that PIK3CA and BRAF contribute to the tumorigenesis of IPMN/IPMC, but at a lower frequency than KRAS. German Society of Surgery, Surgical Forum 2008, Best Abstracts This work was supported by the National Cancer Institute (NCI) Temin Award CA95434 and the NCI R01 CA109525 (GHS).     

A novel mutation in <Emphasis Type="Italic">KCNJ1</Emphasis> in a Bartter syndrome case diagnosed as pseudohypoaldosteronism

Bartter syndrome (BS) is a genetic disorder with hypokalemic metabolic alkalosis and is classified into five types. One of these, type II BS (OMIM 241200), is classified as neonatal Bartter syndrome, which is caused by mutations in the KCNJ1 gene. Transient hyperkalemia and hyponatremia are usually noted in the early postnatal period, but as type II BS is a relatively rare disease, its exact clinical course and genetic background have not yet been thoroughly characterized. This report concerns a male type II BS patient with a novel mutation in the KCNJ1 gene. The unique clinical findings of this case are that hyperkalemia (8.9 mEq/l), hyponatremia, and metabolic acidosis detected in the early postnatal period led to a diagnosis of pseudohypoaldosteronism (PHA). As an adolescent, however, the patient currently shows normal potassium levels and normal renal function, although with hypercalciuria and nephrocalcinosis, without having received any treatment. In such cases, KCNJ1 mutations should be suspected. In our case, genetic analysis of the KCNJ1 gene identified a novel homozygous 1-bp deletion mutation (c.607 del. C in exon 5).     

Acute glomerulonephritis in three siblings and suspected <Emphasis Type="Italic">emm</Emphasis>49-type <Emphasis Type="Italic">Streptococcus pyogenes</Emphasis> infection

Three siblings with poststreptococcal acute glomerulonephritis are presented. Streptococcal infection, impetigo, and pharyngitis preceded the acute glomerulonephritis. In one patient, emm49-type Streptococcus pyogenes was isolated, a strain which has not been reported as nephritogenic in Japan.     

Role of glycemic elements of <Emphasis Type="Italic">Cynodon dactylon</Emphasis> and <Emphasis Type="Italic">Musa paradisiaca</Emphasis> in diabetes management

The study defined the scientific evaluation of glycemic elements of extracts of Cynodon dactylon and Musa paradisiaca. A dose of 500 mg/kg body weight (bw) of C. dactylon produced maximum falls of 23.2% and 22.8% in blood glucose levels of normoglycemic rats during studies of fasting blood glucose and glucose tolerance, respectively, whereas the same dose of M. paradisiaca produced a rise of 34.9% and 18.4%. In diabetic rats during glucose tolerance tests, a fall of 27.8% and a rise of 17.5% were observed with the same dose of C. dactylon and M. paradisiaca, respectively. Laser-induced breakdown spectroscopy used for detection of glycemic elements present in both the extracts indicated that C. dactylon was rich in magnesium (Mg), whereas M. paradisiaca was rich in potassium (K) and sodium (Na), comparatively, suggesting thereby the defined roles of these elements in diabetes management.     

Polymorphisms in <Emphasis Type="Italic">ALOX12</Emphasis>, but not <Emphasis Type="Italic">ALOX15</Emphasis>, Are Significantly Associated With BMD in Postmenopausal Women

The murine arachidonate 15-lipoxygenase gene (Alox15) has recently been identified as a negative regulator of peak bone mineral density (BMD). The human ALOX15 gene shares significant sequence homology with the murine Alox15 gene; however, the human arachidonate 12-lipoxygenase gene (ALOX12) is functionally more similar to the mouse gene. Multiple single-nucleotide polymorphisms (SNPs) in the human ALOX15 and ALOX12 genes have previously been reported to be significantly associated with BMD in humans. On the basis of these data, we carried out our own investigation of the human ALOX15 and ALOX12 genes and their relationship with hip and spine BMD parameters. The study population consisted of 779 postmenopausal women with a mean (± standard deviation) age of 62.5 ± 5.9 years at BMD measurement and was recruited from a single large general practice in Chingford, northeast London. Three SNPs from ALOX15 and five from ALOX12 were analyzed. None of the SNPs that we analyzed in ALOX15 were significantly associated with any of the BMD parameters or fracture data. However, we found that three SNPs from ALOX12, all previously associated with spine BMD in women, were significantly associated with spine and various hip BMD parameters in our cohort (P = 0.029–0.049). In conclusion, we found no association between polymorphism in ALOX15 and BMD phenotypes but were able to replicate previous findings that genetic variation in ALOX12 seems to play a role in determining bone structure in Caucasian women.     

<Emphasis Type="Italic">Candida</Emphasis> in Acute Pancreatitis

Purpose A Candida infection of the pancreas, which previously was considered extremely unusual, has been increasingly reported in recent years. The present study was conducted with the aim of performing a cohort analysis of our patients with acute pancreatitis to find out the incidence, sites, and species of Candida involvement; and to evaluate the risk factors, severity, and course of illness of such patients. Methods A total of 335 patients with acute pancreatitis were investigated for a possible Candida infection of the pancreas from January 2000 to May 2003. The clinical records of all those patients who were positive for Candida spp. isolation from pancreatic tissue were analyzed. The clinical records of 32 more cases, randomly selected from the patients who were investigated for candidal pancreatitis but were negative for Candida spp., were also analyzed in order to compare their findings with those patients with a true Candida infection of the pancreas. Results A true or possible Candida infection was observed in 41 (12.2%) of those 335 patients and Candida tropicalis was the most common isolate (43.9%). Candida spp. were isolated from pancreatic necrotic tissue in 22 (6.6%) patients (true infection). A possible Candida infection (positive drain fluid effluents at least twice, without any Candida isolation from pre/per operative samples from pancreas) was seen in 19 (5.7%) patients. Candida was also isolated exclusively from the blood in another 19 patients with a clinical diagnosis of acute pancreatitis. A risk factor analysis showed that patients with severe injury to the pancreas, on prophylactic fluconazole, and after surgical intervention were significantly more prone to develop a Candida infection. Patients with a Candida superinfection also had a significantly increased hospital stay and higher mortality. Conclusion This study thus emphasizes the important role of Candida infection in patients with acute pancreatitis and demonstrates the need for early attention.     

Radiation induces<Emphasis Type="Italic"> p53</Emphasis>-dependent cell apoptosis in bladder cancer cells with wild-type-<Emphasis Type="Italic">p53</Emphasis> but not in<Emphasis Type="Italic"> p53</Emphasis>-mutated bladder cancer cells

Purpose. It has been reported in several studies that the absence in cancer cells of the p53 tumor suppressor gene, mutations of which are frequently found in bladder cancer, increases their resistance to ionizing radiation. Other studies, however, suggest that mutations of the p53 gene could increase the radiosensitivity of cancer cells, although the evidence is still inconclusive. In the present study, we investigated the relationship between p53 status and radiation response in five different bladder cancer cell lines. Materials and Methods. Five different human bladder cancer cell lines (KK47: with wt-p53, RT4: with wt-p53, T24: with mutated p53, 5637: with mutated p53, UM-UC-3: with mutated p53) were used in the study. Cells were irradiated with 0, 2, 4, 6 or 8 Gy, then trypsinized and re-plated for clonogenic survival assay, quantitative RT-PCR assay, flow-cytometry analysis and TUNEL assay. Results. The clonogenic assay demonstrated that KK47 and RT4 had significantly higher radiosensitivity than other cell lines. Quantitative RT-PCR analysis showed that radiation induced increased expression of p53, Bax, and p21 mRNA in KK47 and RT4. After irradiation, G1 cell-cycle arrest was observed in KK47 and RT4 under flow cytometry analysis, while T24, 5637, and UM-UC-3 showed an increase in the proportion of G2 cells. Increased cell apoptosis was also observed under TUNEL assay in KK47 and RT4, but not in other cell lines. Conclusions: It was demonstrated that ionizing radiation induces p53-dependent cell apoptosis in bladder cancer cells with wt-p53 but not in those with mutated p53.     

Reduction in oxalate-induced renal tubular epithelial cell injury by an extract from <Emphasis Type="Italic">Quercus salicina</Emphasis> Blume/<Emphasis Type="Italic">Quercus stenophylla</Emphasis> Makino

Urocalun, a herbal medicine prepared from an extract of Quercus salicina Blume/Quercus stenophylla Makino (QS extract), has been clinically used for the treatment of urolithiasis in Japan since 1969. In the present study, the effects of QS extract on oxalate-induced cell injury and NADPH-induced superoxide anion (O(2) (-)) production in the injured cells were investigated. Oxalate-induced cell injury was assessed by mitochondrial reduction of 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyltetrazolium bromide and leakage of lactate dehydrogenase into the extracellular fluid. When NRK-52E cells were injured by exposure to oxalate for 24 h, QS extract prevented the injury in a dose-dependent manner. In addition, QS extract suppressed the increase in NADPH-induced O(2) (-) production, or NADPH oxidase activity, in the homogenate of cells injured by oxalate exposure. These findings suggest that the reduction in oxalate-induced O(2) (-) production contributes to the cytoprotective effect of QS extract.     

The population-specific distribution and frequencies of genomic variants in the<Emphasis Type="Italic"> SLC3A1</Emphasis> and<Emphasis Type="Italic"> SLC7A9</Emphasis> genes and their application in molecular genetic testing of cystinuria

Cystinuria is a common inherited aminoaciduria resulting in nephrolithiasis. Mutations in two genes, SLC3A1 and SLC7A9, have been identified in cystinuric patients. Considering the population-specific distribution of genetic variants in the SLC3A1 gene, we focused our study on mutations in SLC3A1 and SLC7A9 described more than once in the literature. We evaluated the usefulness of this restricted analysis as a diagnostic approach. Furthermore, the data obtained were used to estimate the frequency of heterozygote carriers of SLC3A1 mutations in the general European population. A total of 22 unclassified cystinuric patients were screened for genetic variants in four exons of both SLC3A1 and SLC7A9 in which the most common mutations have been identified. For screening, we used single strand conformation polymorphism analysis (SSCP), restriction assays, real-time PCR and direct sequencing. In total, we identified mutations in 17 of our 22 patients, including a new mutation (R365Q) as well as a novel polymorphism (c.1035G/A) within the SLC3A1 gene. An ethnic influence on the distribution of mutations was confirmed: T216M in SLC3A1 is the major mutation in south-eastern Europe, whereas M467T in SLC3A1 is mainly found in western Europe. A complex duplication in SLC3A1 is restricted to German patients. Generally, we could show that a stepwise analysis directed to the most common mutations in the two cystinuria genes is sufficient to detect variants in more than 75% of patients of European origin. The test consists of nine different PCR-based approaches and therefore represents a low-cost, reliable and timesaving diagnostic tool.