Clinical implications of p53 mutation analysis in bladder cancer tissue and urine sediment by functional assay in yeast

In the present study we correlate the p53 gene mutations in tumour tissue with urine sediment using a functional assay in yeast, and relate the p53 status to the outcome in a group of patients with transitional cell carcinoma of the bladder. The p53 mutations were found in three of 30 (10%) Ta/T1 tumour tissue samples and in two of 20 (10%) corresponding urine sediments. In the stage T2-T4 tumour p53 mutations were found in tumour tissues and urine sediments in 13 of 31 (42%) and in seven of 18 (39%) samples, respectively. In 80% (8/10) of cases, the p53 mutations found in tumour tissue were re-detected in urine sediment. Median follow-up was at 20 months. Disease recurred in 18 of the 61 patients (30%) with a median time of 5 months. In Ta/T1 tumours the frequency of recurrence was 37% (11/30) compared with 23% (7/31) of T2-T4 tumours. The 3-year overall survival (OS) was 82% (50/61). The p53 status was significantly associated with stage (P = 0.0077, two-sided Fisher's exact test), grade (P < 0.001) and lymph node involvement (P = 0.027). There was an association between the p53 mutations and shorter OS (P = 0.033; log-rank test); however in a multivariate analysis adjusted for stage, grade, lymph node status and age the p53 mutation was not an independent predictor of survival. There was no correlation of the p53 status with decreased disease-free survival (P = 0.8; log-rank test). The data presented indicate that the yeast functional assay is a useful method for p53 gene mutation analysis in tumour tissue and p53 mutation can be re-detected in urine sediment, but further validation of the assay in non-invasive screening for p53 mutations is needed.     

Response to: “Letter to the Editor,International Urology and Nephrology: Retrograde urethrography,sonouretrography and magnetic resonance urethrography in evaluation of male urethral strictures: should the novel methods become the new standard in radiological diagnosis of urethral stricture disease?”

International Urology and Nephrology -     

Anatomical and functional alterations in semantic dementia: a voxel-based MRI and PET study

Rare studies have used magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) to assess atrophy, and only two positron emission tomography (PET) studies used SPM to examine functional changes in semantic dementia (SD). Our aim was to highlight both morphological and functional abnormalities in a same group of 10 SD patients, in the entire brain, using a “state of the art” methodology (optimized VBM procedure, PET data corrected for partial volume effects and voxel-based analyses). We also used an extensive neuropsychological battery. We showed that main alterations concerned the left temporal lobe, in accordance with the striking impairment of semantic memory in SD patients, as well as the hippocampal region, which may partly explain their moderate episodic memory deficits. Hypometabolism was more extensive than grey matter loss in both temporal lobes, and specifically concerned the orbitofrontal areas, consistent with the moderate impairment of executive functions and behavioural changes. While PET is more sensitive than MRI, there is striking concordance between morphological and functional abnormalities, which contrasts with the discordance observed in Alzheimer's disease and might be a typical feature of SD.     

Genomic instability analysis of urine sediment versus tumor tissue in transitional cell carcinoma of the urinary bladder

Microsatellite alterations are a common feature of neoplastic cells. Our study aimed to compare the profile of microsatellite DNA alterations in tumor tissue and urine sediment at 12 selected microsatellite loci in transitional cell carcinoma of the bladder, and to determine which of the 12 markers or combination of markers has potential for the non-invasive diagnosis of bladder cancer. DNA alterations were examined using microsatellite markers on chromosomes 2p, 3p, 8p, 9p, 9q, 12q, 13q, 17p and 18q in 38 patients, including 12 with superficial Ta/T1 and 26 with muscle invasive T2-T4 bladder tumors. Microsatellite instability was a rare event in comparison with loss of heterozygosity and was related to a low rate of defects in mismatch repair genes. The sensitivity of microsatellite analysis was 75% (9/12) for Ta/T1 tumors and 69% (18/26) for T2-T4 tumors. Two tetranucleotide markers, D9S242 and D9S252, when combined, displayed microsatellite alterations in 59% (16/27) of microsatellite analysis-positive patients. DNA alterations were not detected in 21 non-tumor specimens. Twenty of 51 (39%) tumor DNA alterations were re-detected in urine sediments, and 7 alterations found in urine sediments were not found in the corresponding tumor specimens. No association was found between the DNA alterations and any of the prognostic parameters. However, the overall survival correlated with microsatellite alterations (P=0.04, log-rank test). These data suggest that markers at tetranucleotide repeats on chromosome 9q have particular diagnostic potential in bladder cancer. Moreover, microsatellite analysis is suitable for the selection of patients with a less favorable outcome.     

Mechanistic studies on the reversible metabolism of rofecoxib to 5-hydroxyrofecoxib in the rat: evidence for transient ring opening of a substituted 2-furanone derivative using stable isotope-labeling techniques.

Rofecoxib is a potent and highly selective cyclooxygenase-2 inhibitor used for the treatment of osteoarthritis and pain. Following administration of [4-(14)C]rofecoxib to intact rats, the plasma C(max) (at approximately 1 h) was followed by a secondary C(max) (at approximately 10 h), which was not observed in bile duct-cannulated rats. Following administration of [4-(14)C]5-hydroxyrofecoxib to intact or bile duct-cannulated rats, radiolabeled rofecoxib was detected in plasma, and once again a secondary C(max) for rofecoxib was observed (at approximately 10 h), which occurred only in the intact animals. These results indicate that reversible metabolism of rofecoxib to 5-hydroxyrofecoxib occurs in the rat and that the process is dependent upon an uninterrupted bile flow. Studies on the contents of the gastrointestinal tract of rats showed that conversion of 5-hydroxyrofecoxib to parent compound occurs largely in the lower intestine. Treatment of rats with [5-(18)O]5-hydroxyrofecoxib, followed by liquid chromatography-tandem mass spectrometry analyses of plasma samples, confirmed that 5-hydroxyrofecoxib undergoes metabolism to the parent drug, yielding [1-(18)O]rofecoxib, [2-(18)O]rofecoxib, and unlabeled rofecoxib. Similarly, treatment with [1,2-(18)O(2)]rofecoxib afforded the same three isotopic variants of rofecoxib. These findings are consistent with a metabolic sequence involving 5-hydroxylation of rofecoxib, biliary elimination of the corresponding glucuronide, and deconjugation of the glucuronide in the lower gastrointestinal tract. Reduction of the 5-hydroxyrofecoxib thus liberated yields a hydroxyacid that cyclizes spontaneously to regenerate rofecoxib, which is reabsorbed and enters the systemic circulation. This sequence represents a novel form of enterohepatic recycling and reflects the susceptibility of 5-hydroxyrofecoxib, as well as rofecoxib itself, to reversible 2-furanone ring opening under in vivo conditions.     

Cancer risks in first-degree relatives of CHEK2 mutation carriers: effects of mutation type and cancer site in proband

It is important to have accurate knowledge of the range of cancers associated with various CHEK2 mutations, and of the lifetime risks of cancer associated with each. We wished to establish the relationship between family history, mutation type and cancer risk in families with a CHEK2 mutation. We obtained a blood sample and pedigree information from 2012 unselected women with breast cancer, from 2007 men with prostate cancer and from 1934 patients with colon cancer, from hospitals throughout Poland. Genetic testing was carried out for four founder CHEK2 mutations on all 5953 specimens and 533 carriers were identified. We estimated the risk to age 75 for any cancer in the 2544 first-degree relatives to be 22.3%. After adjusting for mutation type, the risk of breast cancer was much higher among relatives of probands with breast cancer than among relatives of patients with prostate or colon cancer (HR=3.6; 95% CI=2.1–6.2; P=0.0001). Similarly, the risk of prostate cancer was higher among relatives of probands with prostate cancer than among relatives of patients with breast or colon cancer (HR=4.4; 95% CI=2.2–8.7; P=0.0001) and the risk of colon cancer was higher among relatives of probands with colon cancer than among relatives of patients with prostate or breast cancer (HR=4.2; 95% CI=2.4–7.8; P=0.0001). These analyses suggest that the risk of cancer in a carrier of a CHEK2 mutation is dependent on the family history of cancer.     

Das präformierte LCP®-Plattenfixateursystem bei distalen Humerusfrakturen AO-Typ 13C3

In distal intraarticular humerus fractures primary stable osteosynthesis is essential for early mobilization of the elbow joint. Double-plate osteosynthesis techniques using different configurations are the gold standard. In the literature plate position is sometimes discussed controversially. In cases of distal humerus fractures (type AO 13C3) with metaphyseal comminution, as well as in elderly patients with poor bone quality, utilizing locking plates with angular stability was found to have increased structural properties with regard to primary fixation stability. The dorsal approach with osteotomy of the olecranon seems to be very effective in open reduction and internal fixation of this type of fracture.One new development is the anatomically preformed plate-fixation systems such as the LCP-System for distal humerus (Synthes). This study presents our first experience with this system in 11 cases of open reduction and internal fixation of type AO 13C3 distal humerus fractures. The system-specific features and intraoperative options were analyzed.     

Staged bone grafting following placement of an antibiotic spacer block for the management of segmental long bone defects

Segmental long bone defects resulting from injury or surgical intervention are difficult problems to manage. Amputation, external fixators, vascularized fibular grafts, acute limb shortening, and various quantities of allograft and autograft have historically been the mainstays of treatment. Recently, the use of osteoinductive substances such as recombinant bone morphogenic proteins, and osteoconductive scaffolds such as calcium phosphate have found use in the treatment of these clinical situations. More recently, Masquelet described the use of a cement spacer placed within the osseous void followed by staged bone grafting within the induced biomembrane formed around the spacer as a potential treatment strategy to manage these large defects.This article describes a series of 11 patients for which we used this technique of staged bone grafting following placement of an antibiotic spacer to successfully manage osseous long bone defects ranging from 4 to 15 cm. The limbs were stabilized and aligned at the time of initial spacer placement with a plate and screw construct, intramedullary nail, or fine wire fixator. Osteoinductive substances including bone morphogenic protein-2 and platelet rich concentrate were used in addition to allograft to improve bony healing. In our series, osseous consolidation and full weight bearing was achieved in 10 of 11 patients. Two patients developed heterotopic ossification. There was 1 non-union and 1 infection, which occurred in the same patient. Staged bone grafting within an induced biomembrane created after the use of a cement spacer is a reasonable option in the management of both acute and delayed segmental long bone defects.