Your search found 4 Results
Geneva, WHO, 1973. (WHO Technical Report Series No. 520) 34 p.After summarizing current WHO research directed at the control of male fertility focusing on 1) gametogenesis and ultrastructure of the testis; 2) cytogenetic aspects; 3) hormonal regulation; 4) epididymal function (the maturation and preservation of spermatozoa); 5) vas deferens; and 6) semen analysis; recommendations for further research in the area are made. Studies are required on the following aspects of reproductive function in the male: 1) structural and cytochemical organization of the various classes of germ cells in humans and nonhuman primates; 2) interstitial tissues and the components of the blood-testis barrier and their role in the regulation of gametogenic function of the testis; 3) structural and functional state of the testis during growth and development, during aging, and in most histopathological conditions leading to partial or complete sterility; 4) the role of meiotic chromosome aberration in degeneration of germ cells; 5) role of abnormal chromosomes as an etiological factor in male infertility; 6) binding and metabolism of androgens and their effects on the seminiferous tubule; 7) role of gonadotropins, particularly follicle stimulating hormone (FSH), in regulation of spermatogenesis; 8) identification of tubular factors involved in regulation of FSH secretion; 9) elucidation of epididymal function in a number of species; 10) characteristics of sperm surface; 11) nature of epididymal plasma and the factors that control it; 12) anatomy, physiology, and functional role of human vas deferens, with emphasis on blood supply; 13) effect of vasectomy on male reproductive function and possible immunological sequelae of this operation; 14) relationship between fertility and such characteristics of sperm as number, motility, and morphology; 15) biochemical characteristics of the nucleus, acrosome, and midpiece of sperm, and their relationship to sperm motility and fertility; 16) chemical nature of substances secreted specifically in different accessory sex organs; 17) the possible relationship between autoimmune phenomenoa and testicular disease; and 18) immunological sequelae of vasectomy. In addition, studies on the cryobiology of human and animal sperm are expected to yield information on the biology of sperm.
Contraception. 1973 Jul; 8(1):67-73.The World Health Organization (WHO) Program of Research in Human Reproduction that began in 1972 deals with the development of a variety of safe, acceptable, and effective methods for the regulation of human fertility. Research has concentrated on areas where international collaboration would be most likely to accelerate the development of new methods. The program is clinically oriented and emphasizes meeting the objectives in the shortest possible time. Collaborative task force research was started in the following fields: 1) methods to interfere with the transport and/or survival of the ovum; 2) methods to prevent the implantation of the fertilized ovum in the uterus; 3) contraceptive methods for men that affect the fertilizing capacity of sperm by interfering with their maturation and survival without affecting sexual competence; and 4) methods to regulate sperm migration and survival in the human female.
In: Diczfalusy, E., ed. Regulation of human fertility. (Proceedings of the WHO Symposium on Advances in Fertility Regulation, Moscow, USSR, November 16-19, 1976). Copenhagan, Denmark, Scriptor, 1977. 72-87.Recent evidence has shown that spermatogenesis and steroidogenesis are not independent testicular functions, but rather represent a feedback mechanism. Spermatogenesis in mammals can be divided into 3 stages: 1) mitotic replication of stem cells, the spermatogonia; 2) the meiotic process involving primary and secondary spermatocytes; and 3) spermiogenesis--a complex series of cytological changes resulting in transition of conventional cell into a spermatozoon. These cytological changes include 1) elaboration of the acrosomal cap by the Golgi complex; 2) change in nuclear position from central to eccentric; 3) formation of axial filament and its associated organelles from Golgi-adjacent centrioles; and 4) rearrangement of the cytoplasm of spermatids toward the abaacrosomal pole of the spermatid. The kinetics of spermatogenesis show a biological constant for most species in duration of time for conversion from spermatogonia to sperm (64 days in humans). It is generally agreed that luteinizing hormone and follicle stimulating hormone are required for initiation of spermatogenesis at puberty in humans and rats, though controversy exists over whether both hormones are necessary for maintenance. The action of increasing doses of testosterone in suppressing and then stimulating spermatogenesis suggests that a high local concentration of testosterone is required for the spermatogenic process. Evidence supports high androgen concentration within the seminiferous tubules, but its entry route is still speculative. Relationship of Sertoli cell to spermatogenesis and hormonal interrelationship between the testis and hypothalamo-hypophyseal unit are discussed. Sperm maturation is attributed to: 1) inherent ability of sperm to mature, and 2) specialized environment of the epididymis.
Bibliography on human reproduction, family planning and population dynamics: annotated articles and unpublished work in the South-East Asia Region: male reproduction and Fertility Control (including review of current status).
New Delhi, India, World Health Organization, Regional Office for South-East Asia, April 1975. (Special Supplement No. 3) 119 pThis annotated bibliography focusses on male reproduction and fertility control. A review of current status covers 7 broad categories of information: 1) the testis; 2) accessory sexual glands; 3) semen; 4) factors affecting the sperm in vitro; 5) interference with testicular function; 6) interference with sperm in the epididymis; and 7) current methods of male contraception. The opening section lists source materials for testis and spermatogenesis, epididymis and other accessory organs; composition of semen; spermatozoa; effects of steroid and nonsteroid compounds; vasectomy and contraceptive techniques; immunological aspects; and infertility. Sample titles are "Fructose and citric acid in human semen," and "Studies with sub-tropic doses of oc-chlorohydrin in the male monkey.""