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Biomedical subjects

A Valéri

Publications and source records attributed to A Valéri.

10 recordsLinked to original sources
PubMed2004

Chromosomal abnormalities in couples undergoing intracytoplasmic sperm injection. A study of 370 couples and review of the literature.

Intracytoplasmic sperm injection (ICSI) is now widely acknowledged as the most effective therapeutic approach to severe male infertility or unsuccessful in vitro fertilization. Cytogenetic investigations were performed in 370 females and 335 males prior to ICSI between January 1997 and April 2003. Nine men (2.7%) and 48 women (13%) had an abnormal karyotype, 44 females having some degree of numerical sex chromosome mosaicism. A review of the literature showed the prevalence of all types of chromosomal abnormalities to be much higher among male and female partners of couples examined prior to ICSI than among newborns. As most ICSIs are performed with ejaculated spermatozoa from oligospermic men, the distribution and the prevalence of the several types of chromosomal abnormalities are closer to those of oligospermic rather than azoospermic males. Our results combined with those of the literature stress the importance of karyotyping both male and female partners before ICSI is started. Adequate genetic counselling, possibly followed by prenatal diagnosis, should be offered if a chromosomal anomaly is detected.

Chromosome Aberrations↗
PubMed2002

Sex chromosome mosaicism in couples undergoing intracytoplasmic sperm injection.

BACKGROUND: Several studies have shown an increased frequency of constitutional chromosome aberrations in male and female partners of couples examined prior to ICSI. We conducted a cohort study to determine whether there was an increase in numerical sex chromosome mosaicism among couples undergoing ICSI compared with fertile couples. METHODS: Cytogenetic investigations were performed in 228 females and 208 males seen for ICSI between January 1997 and March 2001. They were matched to control females and males. RESULTS: Sex chromosome loss or gain was observed in at least one cell from 24.1% of ICSI women in comparison with 22% of controls (not significant). A significant difference between these two groups was found when X chromosome loss in at least two cells was considered, 9.6% for ICSI females versus 4.8% for controls (P = 0.01). No significant difference was observed between male groups concerning loss or gain of the X or Y chromosome. CONCLUSION: Our results support previously published studies indicating that the loss of an X chromosome in a single cell in females undergoing ICSI is probably an artefact. However, they suggest that a woman could have true sex chromosome mosaicism when two 45,X0 cells are found.

Adult↗
PubMed2001

PCAP is the major known prostate cancer predisposing locus in families from south and west Europe.

To date four prostate cancer predisposing loci have been mapped: HPC1 (Hereditary Prostate Cancer 1) on 1q24-25, PCaP (Predisposing for Cancer Prostate) on 1q42.2-43, CAPB (Cancer Prostate and Brain) on 1p36, and HPCX on Xq27-28. We examined evidence for linkage to those loci in 64 families from south and west Europe. Genotyping of three (six for PCaP) markers encompassing the candidate regions were performed on 221 individuals including 159 affected patients. The resulting data were analysed using both parametric and non parametric linkage methods. No significant evidence of linkage to HPC1, CAPB, or HPCX was found either in the whole population or when pedigrees were stratified according to criteria specific to each locus. By contrast, results in favour of linkage to PCaP locus were observed with maximum multipoint NPL and HLOD scores of 2.8 (P = 0.0026) and 2.65 respectively. Homogeneity analysis performed with multipoint LOD scores gave an estimated proportion of families with linkage to this locus up to 50%. Particularly, families with an earlier age at diagnosis (< or = 65-years-old) contributed significantly to the evidence of linkage with a maximum multipoint NPL score of 2.03 (P = 0.024). Those results suggest that PCaP is the most frequent known locus predisposing to hereditary prostate cancer cases from families from south and west Europe.

Aged↗
PubMed2000

VEGF overexpression in clinically localized prostate tumors and neuropilin-1 overexpression in metastatic forms.

Studies comparing tumor neovascularity with pathological findings suggest that angiogenesis contributes to the pathogenesis of prostate cancer. We have examined 42 primary sporadic prostate tumors at different clinical stages, together with 3 prostate cancer cell lines (DU145, PC3 and LNCaP), for expression of VEGF and the gene encoding the recently identified VEGF165 isoform-specific receptor neuropilin-1, by using a quantitative reverse transcription (RT)-PCR method. We also evaluated the VEGF transcription pattern. Upregulation of VEGF and neuropilin-1 was observed in 12 and 14 tumors, respectively. The VEGF165 isoform was slighly overrepresented in tumors that overexpressed VEGF. VEGF overexpression correlated with stage II disease (p < 0.05); neuropilin-1 overexpression correlated with advanced disease (p < 0. 01) and a high Gleason grade (p < 0.02). Our observations suggest that VEGF expression could be used as a prognostic marker in early-stage prostate tumors, whereas neuropilin-1 overexpression might be a marker of aggressiveness.

Endothelial Growth Factors↗
PubMed2000

htert expression correlates with MYC over-expression in human prostate cancer.

Expression of the telomerase catalytic sub-unit (htert) constitutes a key step in the development of human cancer. Although htert regulation is still unclear, several studies suggest that c-myc may activate its expression. Prostate cancer is one of the most common malignancies among men in Western countries. Since de-regulated expression of myc as well as telomerase activation may contribute to the pathogenicity of this cancer, we investigated this pathway in prostate tumorigenesis. For this purpose, myc- and htert-mRNA expression was quantified in 33 sporadic prostate tumors using a real-time quantitative PCR assay based on TaqMan methodology. myc over-expression was observed in 19 (58%) of 33 tumors, whereas telomerase status evaluated by htert expression was observed in 22 (67%). There was no correlation between myc over-expression or htert expression level and tumor stage or Gleason grade. A significant association (p = 0.0024) was found between myc over-expression and elevated htert expression, indicating that the up-regulation of telomerase activity often observed in prostate tumors might be conferred through transactivation of htert by myc. It is likely that the ability of c-myc protein to stimulate expression of htert and thereby enhance telomerase activity represents an important step in prostate tumorigenesis.

DNA Primers↗
PubMed1999

Expression and mutational analysis of the MADR2/Smad2 gene in human prostate cancer.

BACKGROUND: Loss of heterozygosity (LOH) on chromosome arm 18q is common in sporadic prostate cancer and may be involved in cancer development through inactivation of tumor-suppressor genes (TSG). Recent identification, at 18q21.1, of MADR2/Smad2, a key component in transforming growth factor beta (TGFbeta)-family signaling pathways, led us to investigate the role of this gene in prostate tumorigenesis. METHODS: Sporadic primary prostate tumors from 25 patients with clinically localized tumors and 7 with metastatic forms were examined for MADR2/Smad2 mutations by using polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) analysis of cDNA, and for gene expression by quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: We detected no mutation in MADR2/Smad2 and no abnormal mRNA expression. CONCLUSIONS: Despite recent evidence indicating that MADR2/Smad2 acts as a tumor-suppressor gene, our findings suggest a limited role of this gene in prostate tumorigenesis, at least in the early stages. Another key tumor-suppressor gene may therefore be the main target of the observed LOH at 18q21.1.

Biopsy, Needle↗
PubMed1998

[Treatment of metastatic prostate cancer: certainty and doubts].

HIGH MORTALITY: Despite progress in early diagnosis, mainly due to prostate specific antigen (PSA) assay, metastasic cancer of the prostate remains an important health problem; more than 40,000 men died from prostate cancer in 1996 in the USA. More than 50 years after the hormone sensitivity of prostate cancer, antiandrogen therapy remains the cornerstone of treatment protocols. Although this is only a palliative therapy, it does delay disease progression for several years before the tumor inevitably escapes from hormone control. STAGE D1 DISEASE: In patients with microscopic nodal metastases (stage D1) it is classical to propose early or delayed hormone therapy which gives a 5-year survival rate in the 77-85% range. Certain teams also associate radical treatment (radical prostatectomy or pelvic prostate radiotherapy) with the hormone therapy, basically with the aim of better local control despite the lack of proven gain in survival rate. STAGE D2 DISEASE: Medical or surgical castration is the gold standard when the disease reaches stage D2. Specific treatments for urinary, neurological or bone complications may also be associated. Median survival is approximately 3 years. ASYMPTOMATIC PATIENTS: There remains a certain controversy about the best time to initiate treatment. Some advocate treatment immediately upon diagnosis while others propose delaying treatment until the onset of symptoms. There is a trend towards early treatment, but the beneficial effect in terms of survival and quality of life has not been proven. STAGE D3 DISEASE: When the tumor escapes hormone control (stage D3) mean survival is less than one year. Castration should be maintained and antiandrogens, which may have been given initially in combination with castration to achieve total androgen blockade, should be withdrawn (antiandrogen withdrawal syndrome) before assessing the need for second intention hormonal or other treatment. Such second intention regimens usually have a temporary and symptomatic effect. Their indication depends on side effects which may have a deleterious effect on quality of life. Symptomatic treatment plays a predominant role at this stage, combining analgesics, external or metabolic radiotherapy for bone pain, transurethral excision and/or urinary tract derivations for neurological or urological complications, and psychological care which requires the combined efforts of the radiotherapist, oncologist, urologist, and general practitioner.

Androgen Antagonists↗
PubMed1998

[Should we screen for prostate cancer?].

The controversy concerning the justification for prostatic cancer screening is now about ten years old. It is the consequence of several convergent phenomena: the routine use of new diagnostic tools such as prostate specific antigen, ageing of Western populations, increased life expectancy and finally public health economic aspects. Is screening justified before the age of 50 years? The answer is no, except in high-risk families with several cases of prostatic cancer, in which screening should be started at the age of 40 years. Is screening justified after the age of 70 years? The answer is no, except in men between 70 and 75 years whose general state and physiological age suggest that they have a life expectancy exceeding ten years. Is screening justified between 50 and 70 years? There is no global "medico-economic" answer to this question, as medical truth, i.e. the individual's interests, appears to be diametrically opposed to economic truth, i.e. the community's interests, due to the high cost of screening. How can screening be envisaged for the future? In families with no particular risk, screening should be clinical, but will probably start earlier and will continue later, because of the improvement of diagnostic tools and prolongation of life expectancy. In high-risk families, the development of genetic tests will be able to determine whether or not a man has inherited predisposition genes. If he has inherited these genes, he will then be submitted to particularly early, meticulous and repeated screening.

Age Factors↗
PubMed1996

[Familial forms of cancer of the urogenital tract: clinical and genetic features].

Familial forms of renal urinary tract and testicular cancers are rare (1 to 2%), in contrast with prostatic cancer (20%). Among these familial cancers, hereditary forms related to a genetic abnormality transmitted to the offspring are now better known and are of particular practical value for the clinician. Their diagnosis can modify the modalities of the patient's treatment in view of the multifocal nature of the tumours within the same organ and/or the frequent bilateral involvement of paired organs. The risk of transmission of the deleterious gene to the offspring requires information and close surveillance of relatives to allow early diagnosis and a better prognosis. When the predisposing gene is known, surveillance can be exclusively directed towards subjects possessing the deleterious gene in view of the increased cancer risk compared to the general population. This is the case for renal cancer in Von Lippel Lindau disease, and nephroblastoma and exceptional tumours of the urinary tract in Lynch syndrome. In the case of prostatic cancer, the most frequent familial cancer, in which hereditary forms represent 9% of cases, the predisposing gene has not been identified, which means that screening should be proposed to all male members of the family over the age of 40 years, due to the earlier age of development of these forms.

Humans↗