Bellini duct carcinoma

The modern era has brought an appreciation that renal cell carcinoma (RCC) includes diverse subtypes derived from the various parts of the nephron, each with its distinctive genetic basis and tumor biology. Carcinoma of the collecting ducts of Bellini (CDC) is a rare subtype of RCC, with a predictably poor prognosis. This rare subtype represents less than 1% of all kidney carcinomas. It derives from presumably numerous chromosomal losses. It is of chief importance to differentiate CDC from other types of renal cell cancer. Typically, it is characterized by a firm, centrally located tumor with infiltrative borders. Regarding the histopathologic characteristics, we can find complex, highly infiltrative cords with inflamed (desmoplastic) stroma, with high-grade nuclei and mitoses. Most reported cases of CDC had been high grade, advanced stage, and unresponsive to conventional therapies. This rare form of disease highlights the importance of multidisciplinary teams in the management of cancer patients.

Clinicopathologic features with collecting duct carcinoma of kidney: report of 10 cases / 中华病理学杂志

Objective@#To study the pathological features, immunophenotypes, differential diagnoses and prognostic parameters of collecting duct carcinoma of the kidney (CDC).@*Methods@#Clinical imaging, histopathology, immunohistochemistry, and survival data of 10 patients at First Affiliated Hospital of Nanjing Medical University from January 2009 to August 2017 were retrospectively analyzed along with a review of literatures.@*Results@#The clinical symptoms of CDC were not specific, and image examinations showed space-occupying mass lesions. Tumors were mainly located in renal medulla with grey and firm cut face and the presence of focal hemorrhage and necrosis. Microscopically, there were predominant tubular or tubular-papillary structures with associated focal sarcomatoid areas, desmoplastic stromal reaction and lymphoplasmacytic cells infiltration. Tumor cells had marked cytological atypia with high grade nuclei, conspicuous nucleolus and numerous mitoses. Immunohistochemically, tumor cells were strongly positive for CK19, E-cadherin, vimentin, HCK, CK7 and PAX8. The main treatment was radical nephrectomy in the patients. Seven cases died of CDC with median survival of 10 months.@*Conclusions@#CDC is a rare, highly aggressive malignancy of kidney with poor prognosis. Definitive diagnosis should be made by histology and immunohistochemistry. Differential diagnoses include papillary renal cell carcinoma(type Ⅱ), renal medullary carcinoma, infiltrating high grade urothelial carcinoma, renal pelvis adenocarcinoma and metastatic adenocarcinomas.

Ubiquitination of Aquaporin: in the kidney

Ubiquitination is known to be important for endocytosis and lysosomal degradation of aquaporin-2 (AQP2). Ubiquitin (Ub) is covalently attached to the lysine residue of the substrate proteins and activation and attachment of Ub to a target protein is mediated by the action of three enzymes (i.e., E1, E2, and E3). In particular, E3 Ub-protein ligases are known to have substrate specificity. This minireview will discuss the ubiquitination of AQP2 and identification of potential E3 Ub-protein ligases for 1-deamino-8-D-arginine vasopressin (dDAVP)-dependent AQP2 regulation.

Renal Handling of Ammonium and Acid Base Regulation

Renal ammonium metabolism is the primary component of net acid excretion and thereby is critical for acid - base homeostasis. Briefly, ammonium is produced from glutamine in the proximal tubule in a series of biochemical reactions that result in equimolar bicarbonate. Ammonium is predominantly secreted into the luminal fluid via the apical Na++xchanger, NHE3. The thick ascending limb of the loop of Henle reabsorbs luminal ammonium, predominantly by transport of NH4+y the apical Na++Cl - cotransporter, BSC1/NKCC2. This process results in renal interstitial ammonium accumulation. Finally, the collecting duct secretes ammonium from the renal interstitium into the luminal fluid. Although in past ammonium was believed to move across epithelia entirely by passive diffusion, an increasing number of studies demonstrated that specific proteins contribute to renal ammonium transport. Recent studies have yielded important new insights into the mechanisms of renal ammonium transport. In this review, we will discuss renal handling of ammonium, with particular emphasis on the transporters involved in this process.

Expression of Rh Glycoproteins in the Mammalian Kidney

Ammonia metabolism is a fundamental process in the maintenance of life in all living organisms. Recent studies have identified ammonia transporter family proteins in yeast (Mep), plants (Amt), and mammals (Rh glycoproteins). In mammalian kidneys, where ammonia metabolism and transport are critically important for the regulation of systemic acid - base homeostasis, basolateral Rh B glycoprotein and apical/basolateral Rh C glycoprotein are expressed along the distal nephron segments. Data from experimental animal models and knockout mice suggest that the Rh glycoproteins appear to mediate important roles in urinary ammonia excretion.

Construction of sense and antisense eukaryotic expression vector of novel gene Collectrin and its function in cell growth / 北京大学学报(医学版)

Objective: To construct sense and antisense eukaryotic expression vector of novel gene Collectrin and identify its function in cell growth. Methods: The open reading frame of Collectrin was amplified by PCR and inserted into pcDNA3.1/V5 His plasmid. The recombinant plasmid was identified by restriction enzyme analysis and sequencing analysis. The recombinant plasmid was transfected into M 1 cell by using lipofectin mediation after being identified by restriction enzyme analysis and sequencing analysis. RT PCR and Western blot were performed to identify the expression of Collectrin. ? Gal staining was used to define the effect of tansfection .The growth of M 1 cells was examined by MTT and cell counting. Results: Compared with control group, the expression of Collectrin was decreased significantly at both nucleotide and protein levels tansfected by antisense vector, but elevated in sense group. The cell growth was blocked after being transfected by antisense plasmid. Conclusion: The sense and antisense eukaryotic expression vector of novel gene Collectrin was successfully constructed. Collectrin was one of basic factors in cell growth.

Effect of furosemide on Cl -/HCO_3~- exchange in IMCD cell in rabbit kidney / 解放军医学杂志

Objective To evaluate the effect of furosemide on Cl -/HCO- 3 exchange of inner medullary collecting duct(IMCD) in rabbit kidney. Methods The effect of furosemide in different concentrations on the changes in Cl -/HCO- 3 exchange in mono-layer of IMCD cell in rabbit kidney was determined by fluorescent probe technique. Results Cl -/HCO- 3 exchange in IMCD cell could be inhibited by 4.3% by 15?mol/L furo semide solution, and 480?mol/L furosemide solution could inhibit the exchange by 97.4%. The Cl -/HCO- 3 exchange rates of the groups, in which the final concentrations of furosemide were equal to or higher than 30?mol/L, were significantly lower than that of the control group(P