[Trans-ureteral pyelostomy: 5 cases]. / Trans-urétéro-pyélostomie: 5 observations.

The authors report 5 cases of extensive loss of substance of the distal ureter due to radiation fibrosis, operative trauma or tumour invasion; these lesions occurred during the course of a genital tumour in 4 cases and rectal prolapse in one case. The lesion was bilateral and radiation-induced in 2 cases and unilateral in 3 cases. The patients presented with renal colic in 2 cases, renal failure in 1 case and infection in 2 cases (pyelonephritis, septic shock). All patients presented with secondary hydronephrosis. The extent of the lesions made vesical anastomosis impossible, especially as the bladder was irradiated and/or absent in 3 cases. Anastomosis of the proximal ureteric stump onto the contralateral ureter was impossible in the presence of bilateral lesions requiring diversion of the contralateral ureter or due to the short donor ureter, or because of the discordant diameter of the two ureters. Transureteropyelostomy was therefore performed in these 5 cases. The postoperative course was uneventful 4 cases, with a transient anastomotic fistula in only one case. Four of the 5 patients achieved long-term survival with an excellent clinical and radiological result.

[Extemporaneous histological control of margins in prostatectomy for cancer]. / Le contrôle histologique extemporané des marges dans la prostatectomie pour cancer.

A histological study of the margins of radical prostatectomy specimens has been made intraoperatively by frozen section in a series of 66 patients. In 8 of them (12% of all) a positive margin was discovered 10 times at the urethral [3], vesical [2], deferential [1] level, at the level of the Santorini [1] and of the rectoprostatic wall [3]. Further resection was immediately performed until histologically normal tissue was reached in 6 of these patients, for whom positive margins were thus made negative; and the prostatectomy was performed. The prostate was not removed in two patients. Only one positive margin not screened intraoperatively was discovered on definitive specimen examination. The rate of postoperative PSA was lowered in the 6 patients whose margins had been made negative, which is compatible with complete resection. However, 7 of these 8 patients received radiation (45 gray). We made a comparison between the groups with negative (57 patients) and positive margins (9 patients) for preoperative PSA levels, Gleason's scores, and invasion of the capsule, of the seminal vesicles and of the lymph nodes. There was no significant difference between both groups for the PSA levels, Gleason's score and the involvement of the seminal vesicles. Conversely, there was a significant difference between both groups (corrected chi 2 test) for invasion of the capsule (p = 0.02) and of lymph nodes (p = 0.02). Intraoperative histological control allows immediately recognizing and treating some positive margins, in order to choose during the operation whether resection should be widened or abandoned.

Versatile copurification procedure for rapid isolation of homogeneous RAR-RXR heterodimers.

RAR-RXR heterodimeric complexes (RARalphaDeltaAB-RXRalphaDeltaAB) bound to cognate DR5 DNA response elements were purified to apparent structural and functional homogeneity using a novel versatile immobilized metal affinity chromatography (IMAC) copurification procedure. Dynamic light scattering studies indicated that the complexes were more than 85% monodisperse. By electron microscopy the negatively stained RAR-RXR-DNA complexes appeared homogeneous and corresponded to a dimeric arrangement of the molecules. Using heterodimers purified according to this procedure we demonstrate ligand binding of RXR in the context of the RAR-RXR heterodimer-DNA complex. The present copurification procedure is rapid and has yielded high quality heterodimer-DNA complexes suitable for both structural and biochemical studies.

Purification, functional characterization, and crystallization of the ligand binding domain of the retinoid X receptor.

The ligand binding domain (LBD) of the human retinoid X receptor alpha (hRXR alpha) was overproduced in Escherichia coli and purified to more than 95% purity and functional homogeneity. Circular dichroism spectra of the purified RXR alpha LBD indicated that the protein was composed predominantly of alpha-helical structures and coils. Crystals were grown from ammonium citrate using the vapor diffusion method against a reservoir containing 100 mM Pipes (pH 7.0) and 1.5 M ammonium citrate. They belong to the hexagonal space group P6(3)22 with unit cell parameters a = b = 110.8 A and c = 109.9 A, alpha = beta = 90 degrees, gamma = 120 degrees, and they diffract X rays to a resolution limit of 2.5 A using synchrotron radiation. The asymmetric unit of the crystals contains one molecule with a solvent content of approximately 55% and a Vm value of 3.6 A3/dalton.

Surgical resection of locally recurrent colorectal adenocarcinoma.

BACKGROUND: Recurrence rates after curative resection of colorectal adenocarcinoma remain steady at 50 per cent. Thirty per cent of the deaths are linked to locoregional recurrence. The aim of this study was to evaluate the results of resection for locoregional recurrence. METHODS: This retrospective review analyzed a series of 120 patients who underwent resection of colonic (56) or rectal (64) locoregional recurrence. Sixty-nine resections were considered as curative. Sixty-one recurrences required extended resection. There were nine synchronous hepatic resections. RESULTS: The hospital mortality rate was 7 per cent and the morbidity rate was 40 per cent. The overall 5-year survival rate was 27 per cent. Survival was significantly higher: (1) after curative resection (44 versus 0 per cent after palliative resection, P < 0.0001); (2) in women (44 versus 11 per cent for men, P = 0.0036); and (3) after resection for intramural recurrence (45 versus 19 per cent for extramural recurrence, P = 0.0024). Multifactorial analysis showed that curability of the resection was the most important prognostic parameter. CONCLUSION: The results in this highly selected group seem to justify an attempt at reresection whenever possible. Long-term results may be improved by using adjuvant treatment.

Purification of the human RARgamma ligand-binding domain and crystallization of its complex with all-trans retinoic acid.

A 28-kDa fragment (residues 178-423) of the human retinoic acid receptor gamma, hRARgamma D3E, encompassing the ligand-binding domain (LBD) was overproduced in Escherichia coli and purified as a monomer to more than 95% purity and homogeneity. The Kd for all-trans retinoic acid binding was 0.6 +/- 0.1 nM. Crystals of the LBD complexed with all-trans retinoic acid were grown at pH 7 from sodium acetate in the presence of detergents using the vapor diffusion method. They diffract to 2.0 A using a synchrotron radiation (lambda=0.91 A) and belong to the tetragonal space group P4(1)2(1)2 with unit cell parameters a=b=60.6 A and c=155.3 A, one monomer per asymmetric unit, a solvent content of ca. 33%, and a Vm value of approximately 2 A3/dalton.