Bilateral and multiple mixed epithelial and stromal tumors of the kidney: A case report

Mixed epithelial and stromal tumor (MEST) of the kidney is a benign tumor occurring predominantly in older women. Histologically, MEST comprises tubuloglandular and cystic structures in an ovarian-like stroma. Bilateral and multiple cases are rare. We herein present a case of bilateral and multiple MEST in a 43-year-old woman. The patient presented with gross hematuria and was referred to a primary care physician. A computed tomography scan revealed 5 tumors in the right and 2 in the left kidney. Renal cell carcinoma was suspected, and left partial nephrectomy followed by right radical nephrectomy was planned. After the left partial nephrectomy, the histopathological diagnosis was MEST, which was consistent with the results obtained following needle biopsy. Therefore, the contralateral tumor was also suspected to be MEST, and needle biopsy was performed. The histopathological diagnosis was identical and the right kidney was spared. The patient is currently periodically monitored. As MEST is a benign tumor, preoperative diagnosis is crucial for avoiding overtreatment.

Crucial Role of Mesangial Cell-derived Connective Tissue Growth Factor in a Mouse Model of Anti-Glomerular Basement Membrane Glomerulonephritis

Connective tissue growth factor (CTGF) coordinates the signaling of growth factors and promotes fibrosis. Neonatal death of systemic CTGF knockout (KO) mice has hampered analysis of CTGF in adult renal diseases. We established 3 types of CTGF conditional KO (cKO) mice to investigate a role and source of CTGF in anti-glomerular basement membrane (GBM) glomerulonephritis. Tamoxifen-inducible systemic CTGF (Rosa-CTGF) cKO mice exhibited reduced proteinuria with ameliorated crescent formation and mesangial expansion in anti-GBM nephritis after induction. Although CTGF is expressed by podocytes at basal levels, podocyte-specific CTGF (pod-CTGF) cKO mice showed no improvement in renal injury. In contrast, PDGFRα promoter-driven CTGF (Pdgfra-CTGF) cKO mice, which predominantly lack CTGF expression by mesangial cells, exhibited reduced proteinuria with ameliorated histological changes. Glomerular macrophage accumulation, expression of Adgre1 and Ccl2, and ratio of M1/M2 macrophages were all reduced both in Rosa-CTGF cKO and Pdgfra-CTGF cKO mice, but not in pod-CTGF cKO mice. TGF-β1-stimulated Ccl2 upregulation in mesangial cells and macrophage adhesion to activated mesangial cells were decreased by reduction of CTGF. These results reveal a novel mechanism of macrophage migration into glomeruli with nephritis mediated by CTGF derived from mesangial cells, implicating the therapeutic potential of CTGF inhibition in glomerulonephritis.

A case of metastatic Xp11.2 translocation renal cell carcinoma successfully managed by cytoreductive nephrectomy followed by axitinib therapy

Targeted medications for metastatic adult Xp11.2 translocation renal cell carcinoma (RCC) remain to be identified. We herein report a case of metastatic Xp11.2 translocation RCC controlled with cytoreductive nephrectomy (CN) and axitinib therapy. A 57-year-old woman complained of fatigue and low back pain. Imaging studies revealed a right renal tumor, with multiple lung and mediastinal lymph node metastases. Although the patient received 10 mg axitinib therapy for 5 months at the hospital she was initially admitted to, the size of the primary and metastatic lesions was not reduced. Thus, she was referred to the Tokyo Women's Medical University Hospital (Tokyo, Japan) for further treatment, where she underwent CN. On macroscopic examination, almost the entire kidney was replaced by a yellowish brown tumor >80 mm in diameter. Immunohistochemical examination confirmed the diagnosis of Xp11.2 translocation RCC. One month after surgery, axitinib therapy was resumed and the size of the metastatic lesions gradually decreased. These findings suggest that axitinib therapy is effective for adult Xp11.2 translocation RCC.

Production and Analysis of Conditional KO Mice of CCN2 in Kidney

CCN2 has been shown to be closely involved in the progression of renal fibrosis, indicating the potential of CCN2 inhibition as a therapeutic target. Although the examination of the phenotypes of adult CCN2 knockout mice with renal diseases has yielded valuable scientific insights, perinatal death has limited studies of CCN2 in vivo. Conditional knockout technology has become widely used for the deletion of genes in the desired cell populations and time points through the use of cell-specific Cre recombinase-expressing mice. Accordingly, several lines of CCN2 floxed mice have been developed for the assessment of the functional role of CCN2 in adult mice.CCN2 levels are increased in renal fibrosis and proliferative glomerulonephritis, which represent good disease models for evaluating the effects of CCN2 deletion on the kidney. Of these, anti-glomerular basement membrane antibody glomerulonephritis has become the most widely used model for evaluating the effect of increased renal CCN2 expression. Herein, we describe the construction of CCN2 floxed mice and inducible systemic CCN2 conditional knockout mice and methods for the induction of anti-glomerular basement membrane antibody glomerulonephritis.

Increase of Total Nephron Albumin Filtration and Reabsorption in Diabetic Nephropathy

The amount of albumin filtered through the glomeruli and reabsorbed at the proximal tubules in normal and in diabetic kidneys is debated. The megalin/cubilin complex mediates protein reabsorption, but genetic knockout of megalin is perinatally lethal. To overcome current technical problems, we generated a drug-inducible megalin-knockout mouse line, megalin(lox/lox);Ndrg1-CreER^T2 (iMegKO), in which megalin expression can be shut off at any time by administration of tamoxifen (Tam). Tam administration in adult iMegKO mice decreased the expression of renal megalin protein by 92% compared with that in wild-type C57BL/6J mice and almost completely abrogated renal reabsorption of intravenously injected retinol-binding protein. Furthermore, urinary albumin excretion increased to 175 μg/d (0.46 mg albumin/mg creatinine) in Tam-treated iMegKO mice, suggesting that this was the amount of total nephron albumin filtration. By comparing Tam-treated, streptozotocin-induced diabetic iMegKO mice with Tam-treated nondiabetic iMegKO mice, we estimated that the development of diabetes led to a 1.9-fold increase in total nephron albumin filtration, a 1.8-fold increase in reabsorption, and a significant reduction in reabsorption efficiency (86% efficiency versus 96% efficiency in nondiabetic mice). Insulin treatment normalized these abnormalities. Akita;iMegKO mice, another model of type 1 diabetes, showed equivalent results. Finally, nondiabetic iMegKO mice had a glomerular sieving coefficient of albumin of 1.7×10^-5, which approximately doubled in diabetic iMegKO mice. This study reveals actual values and changes of albumin filtration and reabsorption in early diabetic nephropathy in mice, bringing new insights to our understanding of renal albumin dynamics associated with the hyperfiltration status of diabetic nephropathy.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

MicroRNA-26a inhibits TGF-β-induced extracellular matrix protein expression in podocytes by targeting CTGF and is downregulated in diabetic nephropathy

AIMS/HYPOTHESIS

The accumulation of extracellular matrix (ECM) is a characteristic of diabetic nephropathy, and is partially caused by profibrotic proteins TGF-β and connective tissue growth factor (CTGF). We aimed to identify microRNAs (miRNAs) targeting CTGF on podocytes in diabetic nephropathy.

METHODS

We investigated miRNAs targeting CTGF on podocytes with miRNA array analysis and identified a candidate miRNA, miR-26a. Using overexpression and silencing of miR-26a in cultured podocytes, we examined changes of ECM and its host genes. We further investigated glomerular miR-26a expression in humans and in mouse models of diabetic nephropathy.

RESULTS

miR-26a, which was downregulated by TGF-β1, was expressed in glomerular cells including podocytes and in tubules by in situ hybridisation. Glomerular miR-26a expression was downregulated by 70% in streptozotocin-induced diabetic mice. Transfection of miR-26a mimics in cultured human podocytes decreased the CTGF protein level by 50%, and directly inhibited CTGF expression in podocytes, as demonstrated by a reporter assay with the 3'-untranslated region of the CTGF gene. This effect was abolished by a mutant plasmid. miR-26a mimics also inhibited TGF-β1-induced collagen expression, SMAD-binding activity and expression of its host genes CTDSP2 and CTDSPL. Knockdown of CTDSP2 and CTDSPL increased collagen expression in TGF-β-stimulated podocytes, suggesting that host genes also regulate TGF-β/SMAD signalling. Finally, we observed a positive correlation between microdissected glomerular miR-26a expression levels and estimated GFR in patients with diabetic nephropathy.

CONCLUSIONS/INTERPRETATION

The downregulation of miR-26a is involved in the progression of diabetic nephropathy both in humans and in mice through enhanced TGF-β/CTGF signalling.

Relationship between glomerular filtration rate and plasma N-terminal pro B-type natriuretic peptide concentrations in dogs with chronic kidney disease

Plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) concentrations increase in dogs with azotemia. However, the correlation between glomerular filtration rate (GFR) and NT-proBNP concentrations in dogs has not been evaluated. The objective of this study was to evaluate the correlation between GFR and plasma NT-proBNP concentrations in dogs with chronic kidney disease (CKD). In this retrospective cross-sectional study, plasma creatinine (Cre) and NT-proBNP concentrations, plasma iohexol clearance (PCio) values and blood pressure were measured in dogs with CKD. Dogs were classified according to PCio values into D group (dogs with decreased PCio values), and N group (dogs with normal PCio values). Dogs were further categorized on the basis of their systolic blood pressure and PCio values into NT-D group (normotensive dogs with decreased PCio values), NT-N group (normotensive dogs with normal PCio values), HT-D group (hypertensive dogs with decreased PCio values) and HT-N group (hypertensive dogs with normal PCio values). Significant correlations were observed between plasma NT-proBNP and Cre concentrations (r=0.360, P<0.05) and PCio values (r=-0.470, P<0.01). Plasma NT-proBNP concentrations were significantly higher in the D group than in the N group (P<0.001). Plasma NT-proBNP concentrations were significantly higher in the HT-D group than in the other three groups (P ≤ 0.007). No differences in plasma NT-proBNP concentrations were observed between the NT-D and HT-N groups (P=0.28). Plasma NT-proBNP concentrations were significantly lower in the NT-N group than in the other three groups (P ≤ 0.043). Our findings suggest that decreased GFR might be associated with increased plasma NT-proBNP concentrations in dogs, similar to that in humans. In addition, the complication of hypertension in CKD might be associated with further increases in plasma NT-proBNP concentrations. In conclusion, the effects of GFR and blood pressure on the plasma NT-proBNP concentration were small, but it could be necessary to consider the effects when this marker is used to evaluate canine cardiac disease.

Peritoneal fibrosis and high transport are induced in mildly pre-injured peritoneum by 3,4-dideoxyglucosone-3-ene in mice

Peritoneal dialysis (PD) solution contains high concentrations of glucose and glucose degradation products (GDPs). One of several GDPs--3,4-dideoxyglucosone-3-ene (3,4-DGE)--was recently identified as the most reactive and toxic GDP in PD fluids. In vitro, 3,4-DGE has been shown to induce mesothelial cell damage; however, its role in peritoneal fibrosis in vivo remains unclear. In the present study, we intraperitoneally administered chlorhexidine gluconate (CG) for mild peritoneal injury, and we then injected 3,4-DGE [38 μmol/L (low concentration) or 145 μmol/L (high concentration)] 5 times weekly for 4 weeks. Significant thickening of the parietal peritoneal membrane was observed only when treatment with low or high concentrations of 3,4-DGE occurred after CG administration, but not when either CG or 3,4-DGE alone was given. The combination of CG and 3,4-DGE also caused upregulation of messenger RNA expression of transforming growth factor β1, connective tissue growth factor, fibronectin, collagen type 1 α1 chain, alpha smooth muscle actin (α-SMA), vascular endothelial growth factor 164, NADPH oxidase 1 and 4, p22phox, p47phox, and gp91phox in peritoneal tissue. Treatment with CG alone was sufficient to cause significant F4/80-positive macrophage infiltration, appearance of α-SMA-positive cells, and vessel formation in the submesothelial layer. Addition of 3,4-DGE markedly enhanced those changes and induced apoptosis, mainly in leukocytes. The concentration of 3,4-DGE in the abdominal cavity declined more rapidly in CG-treated mice than in PBS-treated mice. Peritoneal membrane permeability determined by peritoneal equilibration test showed high transport conditions in peritoneum treated with both CG and 3,4-DGE. These results indicate that, when mild peritoneal damage is already present, 3,4-DGE causes peritoneal thickening and fibrosis, resulting in deterioration of peritoneal membrane function.

Effects of different light intensities in the morning on dim light melatonin onset

The present study evaluated the effects of exposure to light intensity in the morning on dim light melatonin onset (DLMO). The tested light intensities were 750 lux, 150 lux, 3000 lux, 6000 lux and 12,000 lux (horizontal illuminance at cornea), using commercial 5000 K fluorescent lamps. Eleven healthy males aged 21-31 participated in 2-day experiments for each light condition. On the first experimental day (day 1), subjects were exposed to dim light (<30 lux) for 3 h in the morning (09:00-12:00). On the same day, saliva samples were taken in dim light (<30 lux) every 30 min from 21:00 to 01:00 to determine the DLMO phase. The subjects were allowed to sleep from 01:00 to 08:00. On the second experimental day (day 2), the subjects were exposed to experimental light conditions for 3 h in the morning. The experimental schedule after light exposure was the same as on day 1. On comparing day 2 with day 1, significant phase advances of DLMO were obtained at 3000 lux, 6000 lux and 12,000 lux. These findings indicate that exposure to a necessary intensity from an ordinary light source, such as a fluorescent lamp, in the morning within one day affects melatonin secretion.

A randomized phase II study of gemcitabine (GEM) plus S-1 combination chemotherapy versus GEM monotherapy in patients (pts) with advanced biliary tract cancer (BTC)

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Background: Our previous phase II study demonstrated that GEM/S-1 combination chemotherapy was tolerable and showed good efficacy in pts with advanced BTC (Sasaki et al, Cancer Chemother Pharmacol 2010). This randomized phase II study compared the response rate of GEM/S-1 combination chemotherapy and GEM monotherapy in pts with advanced BTC.

Methods: Pts with advanced BTC who had at least one measurable lesion were randomized into two groups. GEM/S-1: GEM 1,000 mg/m2 (day 1, 15) and S-1 80 mg/m2 (day 1-14) repeated every 4 weeks. GEM: GEM 1,000 mg/m2 (day 1, 8, 15) repeated every 4 weeks. Treatment was continued until disease progression. The primary endpoint was objective response according to RECIST version 1.0.

Results: From November 2008 to March 2010, 62 pts were enrolled from 13 institutions. Patient characteristics were: median age 72 (range 47-86); Male/Female 36/26; Performance status 0/1/2 (37/22/3). The primary tumor site was; 30 pts in gallbladders, 16 pts in intrahepatic bile ducts, and 16 pts in extrahepatic bile ducts. Seven pts had previous surgical resection. Response rates of GEM/S-1 and GEM were 16.7% and 9.4%, respectively. The median time-to-progressions of GEM/S-1 and GEM were 5.6 months and 4.1 months, respectively.

Conclusions: GEM/S-1 combination chemotherapy is more active than GEM monotherapy in pts with advanced BTC. Updated time-to-progression and overall survival data will be presented at the meeting.

No significant financial relationships to disclose.

Large voltage-induced magnetic anisotropy change in a few atomic layers of iron

In the field of spintronics, researchers have manipulated magnetization using spin-polarized currents. Another option is to use a voltage-induced symmetry change in a ferromagnetic material to cause changes in magnetization or in magnetic anisotropy. However, a significant improvement in efficiency is needed before this approach can be used in memory devices with ultralow power consumption. Here, we show that a relatively small electric field (less than 100 mV nm(-1)) can cause a large change (approximately 40%) in the magnetic anisotropy of a bcc Fe(001)/MgO(001) junction. The effect is tentatively attributed to the change in the relative occupation of 3d orbitals of Fe atoms adjacent to the MgO barrier. Simulations confirm that voltage-controlled magnetization switching in magnetic tunnel junctions is possible using the anisotropy change demonstrated here, which could be of use in the development of low-power logic devices and non-volatile memory cells.

Endoscopic transpapillary approach to the gallbladder for diagnosing gallbladder cancer

PURPOSE

Gallbladder cancer (GBC) has a poor prognosis that is related to delayed diagnosis. The present study evaluated the efficacy of the transcystic ductal approach in diagnosing GBC.

METHODS

A catheter was introduced into the gallbladder endoscopically via the cystic duct to obtain bile for cytology. Subsequently, cytology specimens were collected using a brush, and intraductal ultrasonography (IDUS) was performed using a miniature probe in patients suspected of having GBC.

RESULTS

Bile cytology was performed successfully in 23 of 25 patients (92%). The sensitivity, specificity and accuracy of cytology were 44.4%, 100% and 78.3%, respectively. Brush cytology and IDUS were successful in six of eight (75%) and nine of 15 (60%) patients, respectively. Brush cytology was positive in two of five patients with GBC. In all four patients with invasive cancer, IDUS showed an irregularity or disruption of the outermost hyperechoic layer.

CONCLUSIONS

The endoscopic transpapillary approach to the gallbladder was useful for the diagnosis of GBC. Brush cytology and IDUS may improve diagnostic efficacy and provide more useful information.

High-rate pulmonary involvement in autoimmune pancreatitis

Autoimmune pancreatitis (AIP) has extrapancreatic complications such as Sjögren's syndrome, retroperitoneal fibrosis and sclerosing cholangitis. We studied 30 patients with AIP. Of these, we identified pulmonary involvement in four patients during follow up. Among them, two patients had respiratory failure. They showed good response to steroid therapy, but a higher dose of prednisolone was necessary to maintain remission than that required in biliary involvement. Elevation of immunoglobulin G(4) and Krebs von den Lungen-6 levels were characteristic of pulmonary involvement. They may be useful for early detection of pulmonary complication.

Phylogenesis of constitutively formed nitric oxide in non-mammals

It is widely recognized that nitric oxide (NO) in mammalian tissues is produced from L-arginine via catalysis by NO synthase (NOS) isoforms such as neuronal NOS (nNOS) and endothelial NOS (eNOS) that are constitutively expressed mainly in the central and peripheral nervous system and vascular endothelial cells, respectively. This review concentrates only on these constitutive NOS (cNOS) isoforms while excluding information about iNOS, which is induced mainly in macrophages upon stimulation by cytokines and polysaccharides. The NO signaling pathway plays a crucial role in the functional regulation of mammalian tissues and organs. Evidence has also been accumulated for the role of NO in invertebrates and non-mammalian vertebrates. Expression of nNOS in the brain and peripheral nervous system is widely determined by staining with NADPH (reduced nicotinamide adenine dinucleotide phosphate) diaphorase or NOS immunoreactivity, and functional roles of NO formed by nNOS are evidenced in the early phylogenetic stages (invertebrates and fishes). On the other hand, the endothelium mainly produces vasodilating prostanoids rather than NO or does not liberate endothelium-derived relaxing factor (EDRF) (fishes), and the ability of endothelial cells to liberate NO is observed later in phylogenetic stages (amphibians). This review article summarizes various types of interesting information obtained from lower organisms (invertebrates, fishes, amphibians, reptiles, and birds) about the properties and distribution of nNOS and eNOS and also the roles of NO produced by the cNOS as an important intercellular signaling molecule.

Extrahepatic biliary obstruction after percutaneous tumour ablation for hepatocellular carcinoma: aetiology and successful treatment with endoscopic papillary balloon dilatation

BACKGROUND AND AIMS

Percutaneous tumour ablation (PTA), such as ethanol injection and radiofrequency ablation, is now recognised as a primary treatment for hepatocellular carcinoma (HCC). Although PTA is a relatively safe procedure, it can cause biliary obstruction as a rare complication. As patients with cirrhosis undergoing surgery or endoscopic retrograde cholangiopancreatography/sphincterotomy have a high mortality rate from bleeding, we adopted the use of endoscopic papillary balloon dilatation (EPBD) in these patients and now report the results. We retrospectively analysed the incidence of biliary obstruction after PTA and the efficacy of treatment with EPBD.

PATIENTS AND METHODS

A total of 1043 patients with HCC were treated by PTA, of whom 538 were treated with transarterial embolisation with up to eight years of follow up.

RESULTS

There were 17 (1.6%) cases of hilar obstruction due to tumour progression and 35 (3.4%) cases of extrahepatic obstruction. Apart from the expected causes of biliary obstruction (haemobilia n = 11, gallstones n = 11, and three miscellaneous causes), we found that 10 patients had obstruction due to biliary casts. This is the first description of biliary casts after percutaneous tumour ablation therapy. Extrahepatic biliary obstruction by procedure related haemobilia occurred within three days of PTA while other causes occurred between 0 and 17 (average 4.9) months. Biliary casts occurred more frequently after ethanol injection than after radiofrequency ablation. EPBD successfully dissipated biliary obstruction in 33 of 35 cases, while two died due to hepatic failure despite successful drainage.

CONCLUSIONS

Extrahepatic biliary obstruction is an uncommon complication after PTA for HCC, and can be safely and effectively treated with EPBD, despite impaired liver function.