Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is generally assumed that men with congenital bilateral absence of the vas deferens (CBAVD) have azoospermia because of obstruction and that sperm production is normal. This study examines spermatogenesis in men with CBAVD to assess the validity of this assumption. We identified all men with CBAVD who had undergone either a diagnostic or therapeutic fertility procedure. Procedures included diagnostic biopsy, testis fine needle aspiration (FNA) mapping, microscopic epididymal sperm aspiration (MESA), and testis sperm extraction (TESE). Among 33 CBAVD men, 18 underwent testis biopsy, 27 had MESA/TESE, and 10 had FNA mapping. On evaluation of these procedures, normal spermatogenesis was present in 29 men. Four men (12%) demonstrated impaired spermatogenesis. One patient had FNA testis cytology consistent with late maturation arrest, another demonstrated hypospermatogenesis on biopsy and low sperm yield by MESA, and two patients had pure Sertoli cell only histology on biopsy. Aetiologies for impaired spermatogenesis included varicocele and underlying genetic abnormalities. Although patients with CBAVD are assumed to have normal spermatogenesis and infertility due simply to obstruction, the potential for concomitant defects in sperm production exists. A clinical suspicion of testis failure should prompt further diagnostic evaluation of spermatogenesis prior to sperm retrieval. In addition, genetic counselling should be offered and testing for genetic lesions, including cystic fibrosis gene mutations and/or variants, Y chromosome microdeletions, and karyotype abnormalities, should be considered.
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PMID:Impaired spermatogenesis in men with congenital absence of the vas deferens. 1122 24

There have not been many studies concerning CFTR gene alterations in nonobstructive causes of male infertility and subfertility, and in those that have been published, the results reported are not concordant. Therefore, we proposed to determine, in a representative unselected sample of men who were sent for microsurgical epididymal sperm aspiration, if different types of male infertility and impaired fertility were associated with CFTR gene alterations. We screened 80 men with idiopathic azoospermia, 50 men with severe oligozoospermia, 70 men with oligoasthenoteratozoospermia, and 7 men with congenital bilateral absence of the vas deferens (CBAVD), as well as 95 controls from Slovenia, for mutations in 10 CFTR exons that include the majority of the most common cystic fibrosis (CF) disease causing mutations. We also wanted to evaluate the risk for CF in children born after the intracytoplasmic sperm injection (ICSI) method of in vitro fertilization (IVF). No tested individual had mutations in both CFTR alleles. Altogether 13 different nucleotide alterations were identified. The frequencies of both CFTR gene alterations and polymorphisms did not differ significantly between the control group and men with idiopathic nonobstructive azoospermia and subfertility, but were significantly increased in men with CBAVD (DeltaF508, p = 0.039; IVS8-5T, p = 0.006). Our results suggest that CFTR mutations are not associated with errors in spermatogenesis and nonobstructive pathology of urogenital tract in men with any frequency. However, genetic counseling and CFTR mutation screening continue to be recommended for men with obstructive azoospermic conditions and their female partners.
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PMID:Involvement of CFTR gene alterations in obstructive and nonobstructive infertility in men. 1178 91

The advent of intracytoplasmic sperm injection (ICSI) has offered new solutions for the management of patients with azoospermia. Surgical sperm recovery combined with ICSI has allowed many men with azoospermia to father their own biological children. Azoospermia can be classified as obstructive and non-obstructive, with investigations, management and success rates varying markedly between the two forms. In certain cases of obstructive azoospermia surgical reconstruction remains a viable option, whereas cases with congenital obstruction need to be screened for mutations of the cystic fibrosis gene. In most cases of obstruction sperm can be retrieved from the epididymis using percutaneous epididymal sperm aspiration (PESA). If PESA is unsuccessful, testicular sperm extraction (TESE) is successful in all cases. With non-obstructive azoospermia, the genetic basis has been investigated intensely. Screening for karyotypic abnormalities as well as Y microdeletions is recommended. Irrespective of the histological diagnosis, focal spermatogenesis can be observed in 40-50% of cases using multiple testicular biopsies.
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PMID:Assisted conception in the azoospermic male. 1189 9

The cystic fibrosis transmembrane conductance regulator (CFTR) and aquaporin-9 (AQP-9) are present in the luminal membrane of the epididymis, where they play an important role in formation of the epididymal fluid. Evidence is accumulating that CFTR regulates other membrane transport proteins besides functioning as a cAMP-activated chloride channel. We have explored the possible interaction between epididymal CFTR and AQP-9 by cloning them from the rat epididymis and expressing them in Xenopus oocytes. The effects of the expressed proteins on oocyte water permeability were studied by immersing oocytes in a hypo-osmotic solution, and the ensuing water flow was measured using a gravimetric method. The results show that AQP-9 alone caused an increase in oocyte water permeability, which could be further potentiated by CFTR. This potentiation was markedly reduced by phloretin and lonidamine (inhibitors of AQP-9 and CFTR, respectively). The regulation of water permeability by CFTR was also demonstrated in intact rat epididymis luminally perfused with a hypo-osmotic solution. Osmotic water reabsorption across the epididymal tubule was reduced by phloretin and lonidamine. Elevation of intracellular cAMP with 3-isobutyl-1-methylxanthine increased osmotic water permeability, whereas inhibiting protein kinase A with H-89 (N-(2-[p-bromocinnamylamino]ethyl)-5-isoquinoline sulfonamide hydrochloride) reduced it. These results are consistent with a role for CFTR in controlling water permeability in the epididymis in vivo. We conclude that this additional role of CFTR in controlling water permeability may have an impact on the genetic disease cystic fibrosis, in which men with a mutated CFTR gene have abnormal epididymis and infertility.
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PMID:Synergistic effects of cystic fibrosis transmembrane conductance regulator and aquaporin-9 in the rat epididymis. 1260 88

Both tumor necrosis factor-alpha (TNF-alpha) and EFA deficiency (EFAD) have been established as causes of marked perturbations in lipid and lipoprotein metabolism. Excessive levels of circulating TNF-alpha can coexist with EFAD in various clinical disorders such as cystic fibrosis and type I diabetes. The present study therefore aimed to investigate their combined effects on lipid profile and lipoprotein composition by administering TNF-alpha to EFAD rats. Lipoprotein lipase (LPL), the rate-limiting enzyme in TG catabolism, was also measured in epididymal adipose tissue. EFAD, after a 4-wk period, induced significant increases in plasma TG (80%, P < 0.001), total cholesterol (TC, 27%, P < 0.025), and HDL-cholesterol (HDL-C, 62%). Two hours after the administration of TNF-alpha, a further rise in TG (43%, P < 0.05) was noted in controls, but not EFAD animals. TC and HDL-C were unaffected by TNF-alpha treatment. In addition, TNF-alpha modified lipoprotein-lipid composition. VLDL and HDL2 derived from EFAD rats were depleted in apolipoprotein (apo) E and apo A-II, and enriched in apo A-I 2 h after TNF-alpha administration. Finally, TNF-alpha decreased adipose tissue LPL activity in both control and EFAD animals. The TNF-alpha-induced inhibition was more marked in EFAD rats. The present results demonstrated that TNF-alpha can amplify or antagonize the effects of EFAD on lipid profile, lipoprotein composition, and LPL activity. These data also suggest that the host's nutritional status is a determining factor for the modulating effect of TNF-alpha on lipid metabolism.
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PMID:Combined effects of EFA deficiency and tumor necrosis factor-alpha on circulating lipoproteins in rats. 1293 68

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians, with a reported incidence of one in 2500. In 97-98% of men with CF, a congenital bilateral absence of the vas deferens (CBAVD) blocks the transport of spermatozoa from testicular or epididymal structures to the outer genital tract, resulting in azoospermia. Abnormalities in semen parameters have also been identified in males with CF. Around 10% of obstructive azoospermia is congenital and is due to mutations the CF gene. It is therefore suggested that men who have CBAVD should be considered for CF screening prior to intracytoplasmic sperm injection (ICSI) treatment. Men with azoospermia of unknown origin should also be considered for screening. Couples requesting surgical sperm retrieval/ICSI should therefore be advised and counselled to bear an elevated risk for CF in their offspring. Counselling of these couples is vitally important in order to help them understand and cope with the diagnosis.
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PMID:Cystic fibrosis mutation screening before assisted reproduction. 1471 39

Azoospermia may occur because of reproductive tract obstruction (obstructive azoospermia) or inadequate production of spermatozoa, such that spermatozoa do not appear in the ejaculate (non-obstructive azoospermia). Azoospermia is diagnosed based on the absence of spermatozoa after centrifugation of complete semen specimens using microscopic analysis. History and physical examination and hormonal analysis (FSH, testosterone) are undertaken to define the cause of azoospermia. Together, these factors provide a >90% prediction of the type of azoospermia (obstructive v. non-obstructive). Full definition of the type of azoospermia is provided based on diagnostic testicular biopsy. Obstructive azoospermia may be congenital (congenital absence of the vas deferens, idiopathic epididymal obstruction) or acquired (from infections, vasectomy, or other iatrogenic injuries to the male reproductive tract). Couples in whom the man has congenital reproductive tract obstruction should have cystic fibrosis (CF) gene mutation analysis for the female partner because of the high risk of the male being a CF carrier. Patients with acquired obstruction of the male reproductive tract may be treated using microsurgical reconstruction or transurethral resection of the ejaculatory ducts, depending on the level of obstruction. Alternatively, sperm retrieval with assisted reproduction may be used to effect pregnancies, with success rates of 25-65% reported by different centres. Non-obstructive azoospermia may be treated by defining the cause of low sperm production and initiating treatment. Genetic evaluation with Y-chromosome microdeletion analysis and karyotype testing provides prognostic information in these men. For men who have had any factors potentially affecting sperm production treated and remain azoospermic, sperm retrieval from the testis may be effective in 30-70% of cases. Once sperm are found, pregnancy rates of 20-50% may be obtained at different centres with in vitro fertilisation and intracytoplasmic sperm injection.
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PMID:Causes of azoospermia and their management. 1536 71

Congenital bilateral absence of the vas deferens (CBAVD) and congenital unilateral absence of the vas deferens (CUAVD) are 2 causes of male sterility; these phenotypes are found in 1%-2% of men investigated for infertility and approximately 10% of men with azoospermia. To study the correlation between genital phenotype and cystic fibrosis genotype in men lacking at least 1 vas deferens, we evaluated the role of different CFTR gene mutations in the morphologic genital phenotype of 119 infertile men with bilateral or unilateral absence of the vas deferens (112 CBAVD and 7 CUAVD patients). Renal, scrotal, and transrectal ultrasonography were systematically performed. CFTR mutations and (TG)m(T)n polymorphism were analyzed, and epididymal and seminal vesicular abnormalities and testicular volume were compared among men with 2, 1, or no CFTR gene mutation, with or without the 5T allele. Our results showed that patients with CBAVD and renal agenesis have the same reproductive tract abnormalities as those with CUAVD, and reproductive tract abnormalities were independent of the subtypes of CFTR genotype in patients with absence of the vas deferens and CFTR gene mutations. Seminal vesicles did not differ between patients with or without CFTR gene mutation, but epididymal abnormalities were more frequent in CBAVD men without the mutation. Low testicular volume was observed in CBAVD men without the CFTR and IVS8-5T mutations, so we can hypothesize that a testicular factor (genetic or environmental) rather than CFTR gene mutations plays a role in determining the phenotype. Further studies using common diagnostic criteria are required to confirm our observations.
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PMID:Correlation between CFTR gene mutations in Iranian men with congenital absence of the vas deferens and anatomical genital phenotype. 1767 36

Cystic fibrosis (CF) is the most common life-shortening autosomal recessive disorder of Caucasians. Most of the men with CF (>95%) have congenital bilateral absence of vas deferens (CBAVD), which makes them infertile. However, with advances in assisted reproductive techniques, it is now potentially possible for these patients to father their own biological children. Spermatozoa may be retrieved from either the epididymis or the testes and combined in vitro with oocytes retrieved from the female partner. Epididymal sperm may be collected either by microsurgical or percutaneous epididymal sperm aspiration. It is important to remember that when assisted reproductive techniques are used for such patients, there is the inevitability of transmitting a mutated cystic fibrosis transmembrane (CFTR) gene, which increases the risk of producing an affected child and can have serious long-term implications. It is therefore mandatory to offer genetic counselling to the men with CF (and CBAVD) and their partners before carrying out assisted reproductive techniques. In the literature, there are a very few studies on fertility treatment of these men. However, even though the reported number of live births in men with CF is small, given the current technology, there are definitely more opportunities for these men to become parents.
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PMID:Infertility and its management in men with cystic fibrosis: review of literature and clinical practices in the UK. 1804 57

Microsurgical or percutaneous epididymal sperm aspiration and intracytoplasmic sperm injection (ICSI) are proposed to overcome male infertility due to congenital bilateral absence of vas deferens (CBAVD). CBAVD has been associated with mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and consequently, genetic counselling has to be addressed before beginning ICSI procedure. However, management of male infertility due to CBAVD should not ignore a mild form of cystic fibrosis. We describe the case of cystic fibrosis late diagnosis performed in a 49-year-old infertile men with CBAVD. CFTR molecular testing detected two mutations F508del and A455E corresponding to a cystic fibrosis genotype. Pneumological evaluation revealed a severe obstructive respiratory disease, bronchiectasis and high sweat chloride levels. Symptoms consistent with a cystic fibrosis have to be identified in infertile men with CBAVD before beginning assisted reproductive procedures.
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PMID:Management of male infertility due to congenital bilateral absence of vas deferens should not ignore the diagnosis of cystic fibrosis. 2324 Sep 68


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