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Pisum sativum root nodule glutamine synthetase (nGS) was partially purified, and Rhizobium leguminosarum glutamine synthetase II (GS II) was purified to homogeneity. Both enzymes possessed a molecular weight in the range of 360 000; GS II appeared to be an octameric enzyme. Antigenic cross-reactivity of nGS and GS II was observed with rabbit antiserum prepared against the purified fractions. The specificity of this reaction was apparent by the lack of immuno-precipitation of R. leguminosarum GS I, and by inhibition of both GS II- and nGS-activity by either anti-GS II or anti-nGS-sera. These results suggest an evolutionary relationship between nGS and GS II.

Contains fulltext : 154027.pdf (Publisher’s version ) (Open Access) Anti-angiogenic treatment with tyrosine kinase inhibitors (TKI) has lead to an impressive increase in progression-free survival for patients with metastatic RCC (mRCC), but mRCC remains largely incurable. We combined sunitinib, targeting the endothelial cells with Girentuximab (monoclonal antibody cG250, recognizing carbonic anhydrase IX (CAIX) targeting the tumor cells to study the effect of sunitinib on the biodistribution of Girentuximab because combination of modalities targeting tumor vasculature and tumor cells might result in improved effect. Nude mice with human RCC xenografts (NU12, SK-RC-52) were treated orally with 0.8 mg/day sunitinib, or vehicle for 7 to 14 days. Three days before start or cessation of treatment mice were injected i.v. with 0.4 MBq/5 mug (111)In-Girentuximab followed by biodistribution studies. Immunohistochemical analyses were performed to study the tumor vasculature and CAIX expression and to confirm Girentuximab uptake. NU12 appeared to represent a sunitinib sensitive tumor: sunitinib treatment resulted in extensive necrosis and decreased microvessel density (MVD). Accumulation of Girentuximab was significantly decreased when sunitinib treatment preceded the antibody injection but remained unchanged when sunitinib followed Girentuximab injection. Cessation of therapy led to a rapid neovascularization, reminiscent of a tumor flare. SK-RC-52 appeared to represent a sunitinib-resistant tumor: (central) tumor necrosis was minimal and MVD was not affected. Sunitinib treatment resulted in increased Girentuximab uptake, regardless of the sequence of treatment. These data indicate that sunitinib can be combined with Girentuximab. Since these two modalities have different modes of action, this combination might lead to enhanced therapeutic efficacy.

Monoclonal antibodies recognizing various structures of the nephron were used to stain renal cell carcinomas and associated metastases. Generally, renal cell carcinoma is subdivided into tumors of a clear-cell type, tumors of a mixed-clear-cell/granular-cell type, and tumors in which spindle cells are present. The staining patterns observed with the monoclonal antibodies used correlated in part with the histological appearance of the carcinomas. One monoclonal antibody did not stain other carcinomas, sarcomas and melanomas tested. Notably the same monoclonal antibody stained 75% of primary tumors, whereas only 16% of metastases were stained. This finding indicates that metastases exist which are made up of less well-differentiated tumor cells than the primary tumors.

Tumor ploidy and expression of renal differentiation antigens as recognized by a previously described series of monoclonal antibodies (MAbs) (RC2, RC3, RC4, RC38, RC69, RC154 and G250) were assessed in 48 renal-cell carcinomas. A positive association was found between aneuploidy and development of metastases. Aneuploid tumors showed a loss of antigen expression more frequently than diploid tumors. This difference was statistically significant for antigens recognized by RC3 and RC69. Loss of RC154 reactivity was associated with increased metastatic potential. Clinical stage was the most powerful single prognostic variable but ploidy and RC3 reactivity carried additional prognostic information.

Item does not contain fulltext Congenital malformations or injuries of the urethra can be treated using existing autologous tissue, but these procedures are sometimes associated with severe complications. Therefore, tissue engineering may be advantageous for generating urethral grafts. We evaluated engineered high-density collagen gel tubes as urethral grafts in 16 male New Zealand white rabbits. The constructs were either acellular or seeded with autologous smooth muscle cells, isolated from an open bladder biopsy. After the formation of a urethral defect by excision, the tissue-engineered grafts were interposed between the remaining urethral ends. No catheter was placed postoperatively. The animals were evaluated at 1 or 3 months by contrast urethrography and histological examination. Comparing the graft caliber to the control urethra at 3 months, a larger caliber was found in the cell-seeded grafts (96.6% of the normal caliber) than in the acellular grafts (42.3%). Histology of acellular and cell-seeded grafts did not show any sign of inflammation, and spontaneous regrowth of urothelium could be demonstrated in all grafts. Urethral fistulae, sometimes associated with stenosis, were observed, which might be prevented by urethral catheter application. High-density collagen gel tubes may be clinically useful as an effective treatment of congenital and acquired urethral pathologies. 01 oktober 2012

Item does not contain fulltext Reconstruction of long ureteral defects often warrants the use of graft tissue and extensive surgical procedures to maintain the safe transport of urine from the kidneys to the urinary bladder. Complication risks, graft failure-related morbidity, and the lack of suitable tissue are major concerns. Tissue engineering might offer an alternative treatment approach in these cases, but ureteral tissue engineering is still an underreported topic in current literature. In this review, the most recent published data regarding ureteral tissue engineering are presented and evaluated, with a focus on cell sources, implantation strategies, and (bio)materials.

Two cases of renal oncocytoma are characterized by histologic electron microscopic, and immunohistochemical evaluation. In one case there was a coexistent renal cell carcinoma. The immunophenotype of the oncocytes provide evidence for an origin from the distal nephron. The results indicate that immunohistochemical methods can be helpful in discriminating renal oncocytoma from (granular type) renal cell carcinoma.