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Biomedical subjects

L Resel

Publications and source records attributed to L Resel.

At least 19 recordsLinked to original sources
PubMed2003

Loss of heterozygosity and methylation of p16 in renal cell carcinoma.

To investigate the possible role of genomic aberrations of chromosome 9p21 in the tumorigenesis of human renal cell carcinoma (RCC), 40 sporadic RCCs were studied using PCR analyses. The tumours were predominantly low stage and low grade. Loss of heterozygosity (LOH) was observed in nine of 39 informative cases, but no homozygous deletion was noticed. Hypermethylation of the promoter region of p16 occurred in eight of the 40 RCCs. No correlation was found between hypermethylation of the p16 gene and LOH on 9p21. A similar level of LOH and methylation was observed in the 40 RCCS regardless of histology, grade and stage. These results suggest that inactivation of p16 and the possibility of other unknown tumour suppressor genes located on other chromosomes could be involved in the pathogenesis of RCC.

Carcinoma, Renal Cell↗
PubMed2002

Long-term follow-up of a randomized prospective trial comparing a standard 81 mg dose of intravesical bacille Calmette-Guérin with a reduced dose of 27 mg in superficial bladder cancer.

OBJECTIVES: To determine the efficacy of a three-fold reduced dose (RD, 27 mg) of intravesical bacille Calmette-Guérin (BCG) against the standard dose (81 mg) in patients with superficial bladder cancer, assessing recurrence, progression and differences in toxicity. PATIENTS AND METHODS: Five hundred patients with superficial bladder cancer (Ta, T1, Tis) were enrolled and randomly assigned to be treated after transurethral resection of all visible lesions with intravesical BCG Connaught strain (weekly x six and thereafter fortnightly x six) either with the standard or RD instillation. RESULTS: All but one of the 500 patients were evaluable for efficacy and toxicity (252 in the standard arm and 247 in the RD arm). The median follow-up was 69 months (maximum 104); 71 (28%) patients in the standard arm and 76 (31%) in the RD arm developed recurrences; the median time to recurrence has not yet been attained, but at 5 years the mean (sd) percentage of recurrence-free patients was 70.5 (3.12) and 70.4 (3.1) for the standard and RD arms, respectively. In patients presenting with multifocal tumours, the standard dose was more effective against recurrences than the RD (P=0.0151). In those with G3 and high-risk tumours overall, the superiority of the standard dose was marginal (P=0.060 and P=0.082). Twenty-nine (11.5%) tumours in the standard arm and 33 (13.3%) in the RD arm progressed to invasive disease; the median time to progression has not yet been attained, but the percentage of progression-free patients at 5 years was 88.8 (2.23) and 86.9 (2.31) for the standard and RD arms, respectively. The standard dose was more effective than the RD against progression only in patients with multifocal disease (P=0.048). Twelve (4.8%) cystectomies were performed in the standard and 15 (6.1%) in the RD arm. Currently, 106 (21.2%) patients have died, but only 38 (7.6%) from bladder cancer, i.e. 20 (7.9%) in the standard and 18 (7.5%) in RD arm. Overall the disease-specific death rate was lower for those patients who completed the scheduled treatment. The cause-specific survival at 5 years did not differ between the arms (P=0.76) but there was a trend toward better cause-specific survival for patients with multifocal tumours in the standard arm. Toxicity differed between the arms, significantly more patients having no toxicity in the RD arm, and fewer having delayed instillations or withdrawing. However, severe systemic toxicity occurred even in patients treated with the RD, in a similar proportion to those receiving the standard dose. CONCLUSION: Overall, the RD gave similar results for recurrence and progression but with significantly less toxicity. However, patients with multifocal tumours fared better with the standard dose and there was a trend towards better recurrence rates in patients with high-risk tumours. We recommend continuing to use the standard dose for high-risk tumours, while we consider the reduced dose safe and effective for intermediate-risk lesions and for maintenance schedules.

Adjuvants, Immunologic↗
PubMed2000

Endothelium-independent relaxation induced by histamine in human dorsal penile artery.

1. In vitro preparations of human dorsal penile arteries were used to evaluate the effect of histamine and to characterize the histamine receptors involved in the response. 2. Cumulative administration of histamine induced a concentration-dependent relaxation in precontracted arteries. The H1 receptor agonist 2-pyridylethylamine induced a biphasic response: contraction followed by dilation. The H2 receptor agonist dimaprit produced a marked relaxation. Mepyramine, a histamine H1 receptor antagonist, led to a slight but statistically significant change in the pD2 value corresponding to the relaxant phase of the H1 receptor agonist and the histamine curve. The H2 receptor antagonist cimetidine induced a marked shift in the dimaprit concentration-response curve without affecting the maximum response. Incubation with cimetidine led to a considerable loss in the sensitivity of the arteries to histamine and in the maximum relaxation. Combined treatment with histamine H1 and H2 receptor antagonists resulted in an additional displacement compared with the effect of each antagonist alone on the histamine response. The effects observed using a histamine H3 receptor agonist and antagonist suggest that the involvement of this receptor is unlikely. 3. Removal of the endothelium was unable to reverse the histamine response. Pretreatment with NG-nitro-L-arginine methyl ester, L-arginine and indomethacin had no effect on the histamine control curve. 4. In conclusion, the vasodilation of human dorsal penile artery induced by histamine seems to be mainly mediated by muscular histamine H2 receptors, without the intervention of key intracellular mediators, such nitric oxide or relaxant prostanoids. A minor population of relaxant histamine H1 receptors cannot be excluded.

Adolescent↗
PubMed2000

Loss of heterozygosity on the short arm of chromosome 3 in renal cancer.

3% of human cancers are renal cell carcinomas (RCC). The most common chromosome abnormality found in this tumor is loss of heterozygosity (LOH) on the short arm of chromosome 3, which suggests that there must be one or more tumor suppressor genes between 3p14 and 3p21 near the VHL gene which play a relevant role in renal cancer development. DNA from normal and tumor tissue from 40 patients at various stages of RCC was analyzed for LOH at three microsatellites mapped to 3p (3p14.1-14.3; 3p21.2-21.3 and 3p25) by polymerase chain reaction). 42.5% of the tumors studied showed LOH on at least one locus. 30% showed LOH on only one locus; 5% on two loci and 7.5% on the three loci tested. LOH occurred only on nonpapillary tumors (p = 0.03). Interestingly, all the tumors with LOH on 3p21 were >/=25 mm (p = 0.04; relative risk 1.76, confidence interval: 1.3-2.3).

Adult↗
PubMed2000

[5'CpG island methylation of the suppressor gene p16/CDKN2/MTS1 in renal carcinoma].

OBJECTIVE: To determine the methylation status of the tumor suppressor gene p16 in patients with renal carcinoma by analysis of microsatellite polymorphisms. METHODS: 40 patients with sporadic renal cancer were studied. Tumor and normal tissue from each patient were tested for methylation status of the p16 gene by analysis of microsatellite polymorphisms. RESULTS: 20% showed methylation of p16. No correlation was found between this genetic alteration and tumor features. CONCLUSIONS: Methylation of p16 was found in 20% of the patients in this series. According to the analysis, 18.5% of renal cell carcinomas showed methylation, 50% of chromophobe cell carcinomas and 25% of carcinomas of Bellini's tubules. The rest of the histological types showed no methylation.

Adult↗
PubMed1998

Expression in human prostate of drug- and carcinogen-metabolizing enzymes: association with prostate cancer risk.

The role of two common polymorphisms of enzymes involved in the metabolism of drugs and carcinogens was studied in relation to prostate cancer. The gene encoding one of these enzymes (NAT2) is located in an area where frequent allelic loss occurs in prostate cancer. Mutations at the genes CYP2D6 and NAT2 were analysed by allele-specific polymerase chain reaction and restriction mapping in DNA from 94 subjects with prostate cancer and 160 male healthy control subjects. Eleven prostate specimens were analysed for genotype and enzymatic activities NAT2, CYP2D6 and CYP3A by using the enzyme-specific substrates sulphamethazine and dextromethorphan. Enzyme activities with substrate specificities corresponding to NAT2, CYP2D6 and CYP3A are present in human prostate tissue, with mean +/-s.d. activities of 4.8+/-4.4 pmol min(-1) mg(-1) protein, 156+/-91 and 112+/-72 nmol min(-1) mg(-1) protein respectively. The Km values for the prostate CYP2D6 and CYP3A enzyme activities corresponded to that of liver CYP2D6 and CYP3A activities, and the CYP2D6 enzyme activity is related to the CYP2D6 genotype. The N-acetyltransferase, in contrast, had a higher Km than NAT2 and was independent of the NAT2 genotype. The CYP2D6 and CYP3A enzymes, and an N-acetyltransferase activity that is independent of the regulation of the NAT2 gene, are expressed in human prostate tissue. The presence of carcinogen-metabolizing enzymes in human prostate with a high interindividual variability may be involved in the regulation of local levels of carcinogens and mutagens and may underlie interindividual differences in cancer susceptibility.

Aged↗
PubMed1998

Sustained-release alfuzosin, finasteride and the combination of both in the treatment of benign prostatic hyperplasia. European ALFIN Study Group.

OBJECTIVES: To assess the additive benefit of combining an alpha1-blocker and a 5alpha-reductase inhibitor. METHODS: This European, randomized, double-blind, multicenter trial involved 1.051 patients with lower urinary tract symptoms related to benign prostatic hyperplasia. Patients received sustained release (SR) alfuzosin (n = 358), a selective alpha1-blocker given at a dose of 5 mg twice daily without dose titration; finasteride (n = 344), 5 mg once daily, or both drugs (n = 349), for 6 months. Primary efficacy criteria were symptomatic improvement (International Prostate Symptom Score: I-PSS) and maximum flow rate (Qmax). Safety was assessed by monitoring adverse events. RESULTS: Symptomatic improvement was significantly higher from the 1st month of treatment with SR alfuzosin, alone or in combination; mean changes in I-PSS versus baseline at end-point were -6.3 and -6.1, respectively, compared with -5.2 with finasteride alone (SR alfuzosin vs. finasteride, p = 0.01; combination vs. finasteride, p = 0.03). The percentages of patients with a decrease in I-PSS of at least 50% were 43, 42 and 33% for SR alfuzosin, the combination and finasteride, respectively (SR alfuzosin vs. finasteride, p = 0.008; combination vs. finasteride, p = 0.009). In the overall population, increases in Qmax were greater with SR alfuzosin and the combination, compared with finasteride alone after 1 month of therapy, but changes at end-point were similar in the three treatment groups. In those 47% of patients likely to be obstructed (baseline Qmax <10 ml/s), however, mean increases in Qmax were significantly higher with SR alfuzosin, alone or in combination, whatever the visit. Finasteride, alone or in combination, significantly impaired sexual function. The incidence of postural symptoms was low and similar in the three treatment groups. CONCLUSION: In this 6-month trial, SR alfuzosin was more effective than finasteride, with no additional benefit in combining both drugs.

5-alpha Reductase Inhibitors↗
PubMed1997

Nitric oxide is involved in the inhibitory neurotransmission and endothelium-dependent relaxations of human small penile arteries.

1. Alteration in the flow of blood to the penis is thought to be the most frequent organic cause of erectile dysfunction or impotence. However, information concerning the penile small arteries (helicine arteries) which control blood flow between the arterial systemic circulation and the cavernous sinusoids is scarce. Therefore, the purpose of the present study was to investigate the involvement of nitric oxide, which is considered to be the main neurotransmitter in corpus cavernosum, in both the non-adrenergic non-cholinergic inhibitory neurotransmission and the endothelium-dependent responses in human penile small arteries. 2. Penile small arteries (lumen diameter 200-700 microns), which were branches of the human deep penile arteries obtained either from patients undergoing penile surgery or from organ donors, were mounted in microvascular myographs for isometric tension recording and electrical field stimulation was performed in the presence of guanethidine and atropine to block adrenergic neurotransmission and muscarinic receptors, respectively. 3. In phenylephrine-contracted penile small arteries, electrical field stimulation (0.5-32 Hz) induced frequency-dependent relaxations of both endothelium-intact and -denuded preparations. The inhibitor of nitric oxide synthase, NG-nitro-L-arginine (3 x 10(-5) mol/l), abolished the relaxations at the lowest frequencies, while slow-developing relaxations were still observed at high frequencies (16 and 32 Hz). The inhibitory effect of NG-nitro-L-arginine was reversed in the presence of L-arginine (3 x 10(-3) mol/l). Tetrodotoxin totally abolished the relaxations to electrical field stimulation. In contracted small penile arteries in the presence of NG-nitro-L-arginine, the nitrovasodilator sodium nitroprusside induced potent relaxations. 4. The endothelium-dependnet vasodilator acetylcholine induced relaxations of penile small arteries, which were only partially reduced in the presence of NG-nitro-L-arginine. In contrast, the relaxations to acetylcholine of trabecular corpus cavernosum preparations were almost abolished in the presence of NG-nitro-L-arginine. 5. The present study suggests that relaxations of human intracavernosal small penile arteries induced by non-adrenergic non-cholinergic nerve stimulation partially involve nitric oxide and also another inhibitory transmitter causing relaxations resistant to nitric oxide synthase blockade. In addition, endothelium-dependnet relaxations in human small penile arteries are mediated by both nitric oxide and a factor resistant to NG-nitro-L-arginine.

Acetylcholine↗
PubMed1992

[High pressure filling bladder].

A complete urodynamic study was carried out on 41 consecutive patients presenting in the cystomanometry a vesical filling pressure at maximum capacity higher than 30 cm H2O. Two groups were evident: group I with neurogenic etiology, and group II without an obvious neurogenic etiology. From its results it can be seen that a diminished vesical accommodation is not a urodynamic fact restricted to vesicourethral neurogenic dysfunction, but it happens in several non-neurogenic conditions. Within the neurogenic group, the urodynamic element most frequently associated to a diminished vesical accommodation was an inferior motor neuron-like vesicourethral dysfunction. An increased vesical filling pressure was not enough to produce urinary incontinence, being also necessary an added factor to prompt involuntary loss of urine.

Adolescent↗
PubMedDate not supplied

[Results of prostatectomy in the treatment of obstructive benign prostatic hypertrophy].

Aimed to evaluate the results of surgery in patients with obstructive prostatic hypertrophy, we studied the clinical and flow measure results from 51 patients undergoing prostatectomy (31 TUR, and 20 retropubic prostatectomies). It was shown that prostatectomy significantly improved the irritation (63% of patients), and most importantly, the obstructive (89%) symptoms. Peak flow increased in 100% of patients while maximum flow percentile in 92% of patients. Post-operative results showed no correlation to the patients' age, duration of evolution or severity of urinary symptoms, weight of prostate removed or histology of the prostate. Our results were compared with those obtained with other therapeutical options, and it was demonstrated that prostatectomy (both retropubic and RUT) are, clinically and urodynamically, the most effective procedure in the treatment of obstructive prostate hypertrophy.

Aged↗
PubMedDate not supplied

[Morphological contributions to the knowledge of testicular pathology (author's transl)].

Among a serie of more than 500 biopsies, the authors show some testicular lesions of difficult interpretation which do not seem to have been reported previously. The electron-microscopical findings are: Contrarily to the uniform thickening of the seminal tube's anhista basal hyalino -esclerosis, in the Klinefelter's syndrome, the anhista shows focal bizarre thickenings, which have been repeteadly observed in the 15 cases studied. Well defined collagen inside the Leydigs's cytoplasm the authors discuss the possible importance of this unique finding in a 28 years old azoospermyc as revealing cellular inmaturity (fibroblastic origin of the interstitial cells). In light microscopy, they discuss the role of the "Hiatus Germinalis", typical of the oligospermies, as related to alterations of the maturation process.

Biopsy↗