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Biomedical subjects

G Paz

Publications and source records attributed to G Paz.

95 records · Page 6Linked to original sources

Three-generation evaluation of Y-chromosome microdeletion.

Sperm cells can be retrieved directly from the testis (testicular sperm extraction [TESE] procedure) and used for intracytoplasmic sperm injection (ICSI), circumventing underlying spermatogenetic defects. Thus, it is important that added information be available on the genetic defects in men undergoing TESE for the ICSI procedure and on the transmission of genetic factors associated with infertility to the offspring. We report a three-generation genetic analysis of a family with a case of male factor infertility. The proband, previously diagnosed as infertile, was physically examined and laboratory tested for gonadotrophic hormones, semen analysis, karyotype and Y-chromosome microdeletion screening in the blood and testis. The Y-chromosome microdeletion screening was performed by multiplex polymerase chain reaction with 20 Y-chromosome sequenced, tagged sites located at the Y chromosome. A microdeletion including the AZF-c region was detected in the azoospermic patient. His father, four brothers, and three offspring born after ICSI also underwent Y-chromosome microdeletion screening. The genetic analysis of the male members of the patient's family did not reveal similar microdeletions. The newborn male was found to bear a Y-chromosome microdeletion similar to that of his father. The fertilization capacity of the proband testicular microdeleted spermatozoa by the ICSI procedure is described. The transfer of the genetic defect raises the possibility that the son will have the same fertility problem as his father.

Adult↗

Morphology of testicular spermatozoa obtained by testicular sperm extraction in obstructive and nonobstructive azoospermic men and its relation to fertilization success in the in vitro fertilization-intracytoplasmic sperm injection system.

The aim of the present study was to evaluate the morphology of testicular spermatozoa by 3 different determinants. Sperm cells were obtained and their morphology was evaluated from 27 testicular sperm extraction (TESE) operations, of which 20 men had nonobstructive azoospermia and 7 had obstructive azoospermia. In 17 cases, 2 biopsies were obtained from 2 different locations of the testis. Only mature spermatozoa presenting full-grown tail (tail dimension about 10-fold greater than the head dimension) were counted. Three characteristics of sperm morphology were evaluated: head dimensions, and acrosome and midpiece irregularities. The percentage of sperm cells with normal morphology (considering the 3 characteristics) in specimens from patients with obstructive and nonobstructive azoospermia were 47% +/- 4.6% and 29 +/- 1.8%, respectively (P < .01). The percentage of spermatozoa with normal head dimensions were 76% +/- 3.2% and 63% +/- 2.6% (P > .05), those with normal acrosome were 58% +/- 4.6% and 41% +/- 3.4% (P < .05), and those with normal midpiece were 74% +/- 4.1% and 67% +/- 1.6% (P > .05), in obstructive and nonobstructive azoospermia, respectively. No significant differences were observed in sperm morphology between different locations of the testis. Sperm morphological characteristics were not associated with fertilization rate in intracytoplasmic sperm injection (ICSI). Follicle-stimulation hormone and luteinizing hormone were inversely correlated with normal morphology of testicular spermatozoa (r = -0.49 and r = -0.47, respectively; P < .05). It can be concluded that a relatively high portion of testicular sperm are morphologically normal. The higher rate of normal spermatozoa in obstructive azoospermia compared with nonobstructive spermatozoa suggests that the factors leading to azoospermia may affect testicular sperm morphology. The morphological characteristics of testicular sperm do not affect fertilization rate in ICSI.

Adult↗

The use of a seminal vesicle specific protein (MHS-5 antigen) for diagnosis of agenesis of vas deferens and seminal vesicles in azoospermic men.

Azoospermia is the cause of infertility in 8% of infertile male patients. Ten percent of those patients suffer from agenesis of the seminal vesicle (SV) and vas deferens (VD) agenesis. Currently, the diagnosis of SV and VD agenesis is based on low semen volume, low pH, and low fructose content of the seminal fluid of azoospermic men who have normal serum gonadotropins. In this study, an SV-specific sperm-coating antigen, the MHS-5 antigen, was used as a marker for the presence of SVs. The SV-specific protein (SVSP), MHS-5, was present in the control group but was not found in any of the seven samples from azoospermic men with proven agenesis of SV and VD. Another semen component, the prostate-specific antigen (PSA), whose presence in the semen is not influenced by the SV and VD agenesis, was found in both the study and the control groups. Its presence ruled out the possibility of azoospermia due to ejaculatory duct obstruction. The absence of MHS-5 antigen in seminal fluid can be used as a tool for a reliable diagnosis of agenesis of SV and VD in azoospermic men.

Biomarkers↗