14 research outputs found
Second generation experimental hybridizations in theEchinocereus �lloydii complex (Cactaceae), and further documentation of dioecy inE. coccineus
A new florally dimorphic hexaploid, Echinocereus yavapaiensis sp. nov. (section Triglochidiatus, Cactaceae) from central Arizona
The use of fluorescent in situ hybridization in male infertility
Male factors are implicated in up to 50% of couples being evaluated and treated for infertility with advanced assisted reproductive technologies. Genetic abnormalities, including sperm chromosome aneuploidy as well as structural aberrations, are one of the major causes of infertility. The use of chromosome-specific DNA probes labeled with fluorochromes, particularly the combination with multiple probes, has been used to indirectly study the sperm chromosome by fluorescent in situ hybridization (FISH). Clinically, this technique is also used to assess the sperm of men recovering from gonadotoxic treatment. Recent advances in this technology facilitate the evaluation of sperm aneuploidy. Sperm FISH is a widely used screening tool to aid in counseling couples with severe male factor infertility, especially in cases of prior repeated in vitro fertilization/intracytoplasmic sperm injection failure or recurrent pregnancy loss. Automation of FISH imaging and analysis, as well as the development of emerging techniques such as comparative genomic hybridization, will all contribute to the promise of future diagnostic approaches aimed at improving the quality, ease, and efficiency of aneuploidy analysis
Experimental documentation of natural hybridization inCactaceae: Origin of Lloyd's Hedgehog Cactus,Echinocereus �lloydii
Inability to obtain sperm for fresh IVF cycles: analysis and incidence of outcomes using a database from the United States
Aberrations in Pseudoautosomal Regions (PARs) Found in Infertile Men with Y-Chromosome Microdeletions
Y-chromosome microdeletions can be associated with previously unrecognized aberrations in PAR; for example, unrecognized SHOX disorders may coexist in men with Y-chromosome microdeletions
Testosterone Therapy in Male Infertility
Normal spermatogenesis is dependent upon production of endogenous testosterone and elevated concentrations of intratesticular testosterone. Testosterone levels typically begin to decrease over time in men starting in their late 30s; however, as many as 12.4% of men below the age of 39 suffer the effects of low testosterone and seek treatment. This statistic suggests that a significant number of men seeking treatment for low testosterone are within their reproductive years, underscoring the importance of appropriate counseling for patients seeking testosterone therapy as it pertains to family planning. The standard treatment for men with low testosterone and symptoms of hypogonadism is administration of exogenous testosterone. The challenge for testosterone replacement among men who desire fertility is that exogenous testosterone is a known contraceptive. The key for treatment of low testosterone while preserving fertility is maintenance of high concentrations of intratesticular testosterone and promotion of endogenous testosterone production. Therapies that accomplish this goal include administration of gonadotropins like GnRH and hCG, selective estrogen receptor modulators like clomiphene citrate, and aromatase inhibitors like anastrozole. Experimental therapies include intranasal testosterone gels and Leydig stem cell transplantation