Induction of precocious maturation of spermatogenesis in infant rats by human menopausal gonadotropin and inhibition by simultaneous administration of gonadotropins and testosterone.

This study was undertaken to determine if the initiation of spermatogenesis could be modified by the administration of gonadotropins and sex hormones in infant rats. Five-day-old rats were injected daily between the 5th and 11th days of life with test substances and killed on day 15. Administration of testosterone propionate (TP; 2.

Pharmacological evaluation of an intra-oral fluoride-releasing device in adolescents.

The purpose of this study was to quantify fluoride (F) concentrations in body fluids of adolescents wearing two intra-oral fluoride-releasing devices (IFRDs) designed to release 0.10 mg F/day. Fluoride concentrations were determined potentiometrically.

A nonspecific disturbance of the gonadostat in women with transsexualism and isolated hypergonadotropism in the male-to-female disturbance of gender identity.

Principal parameters of gonadostat function were determined in 15 female-to-male (F-M) and 7 male-to-female (M-F) transsexual patients (T), all homosexuals. The data were compared with normal heterosexual controls of the respective sex. Anamnesis revealed prolongation of the menstrual cycles in F-M patients, mainly in those taking previously medication with depot-testosterone.

Microbiological and microhardness evaluation of artificial enamel fissures worn intraorally by humans.

Devices simulating occlusal fissures were constructed from dental enamel and bonded to human maxillary molar teeth for 3 weeks. Facilitation of in vivo caries research in humans is the long-range goal for this model system. In the present investigation, microbial compositions of plaque in the fissural space of the model and natural fissural plaque from teeth bearing the devices were compared.

Changes in gonadotropin regulation in both behavioral and phenotypic disturbances of sexual differentiation in men.

Determinations of gonadotropins and testosterone were performed in 22 men with hypospadias (H), seven male-to-female transsexuals (T) and in 16 normal men (N), all of similar age. The response of serum FSH and LH to GnRH was determined in six subjects in each group. Oligospermia was found in five of 13 patients with H.

Microbiological assessment of dental plaque on bovine enamel implants worn intra-orally in children.

Nine caries-active children, each from six to nine years old, wore small removable enamel implants intra-orally for four weeks as part of an effort to develop removable model systems for studying dental plaque in fissures. The implants, consisting of two enamel cubes arranged to simulate a fissural space, were cemented in box preparations in stainless steel crowns on pulpotomized primary molars. Upon removal, the fissural spaces were opened to facilitate plaque harvesting.

Synthesis of testosterone and 5 alpha-reduced androgens during initiation of spermatogenesis in the rat.

Numerous investigators demonstrated increased 5 alpha-reductase activity in testes of developing rats. The rapid in vitro metabolism of progesterone to 5 alpha-reduced androgens occurs at certain stages of testicular development. This was considered evidence for the conclusion that testosterone is primarily an intermediate rather than the final product in testes of immature rats.

In vitro effect of APF gel on three composite resins.

A laboratory study was conducted to determine effects of 1.23% APF gel on three composite resins. All composite resins immersed in APF gel lost significantly more weight than did their controls with significantly different weight losses among the APF-treated composites.

Somatic and germinal cells' interrelationship in the course of seminiferous tubule maturation in man.

Certain successive phases of seminiferous tubule maturation were observed in a transsection of a Leydig cell adenoma-bearing testis of a boy with precocious puberty. Massively accumulated Leydig cells may stimulate the maturation of Sertoli cells, as indicated by progressive replacement of Sertoli cell precursors by mature Sertoli cells at a distance closer to the adenoma. On the other hand, tubules less advanced in maturation contained a higher number of somatic cells than those more advanced in maturation.

Clinical, hormonal and semiological data in adult men operated in childhood for hypospadias.

Examination of 16 adult men operated in childhood for hypospadias revealed signs of moderate injury of the male genital system. It appears that accessory sexual glands were mainly responsible for the observed abnormalities. Since testicular position and size, serum testosterone and FSH levels were normal it seems that hypospadias and the accompanied disturbances are connected with reduction of responsiveness of target tissues to androgen stimuli rather, than with lesion of the testicle.

Serum immunoglobulins IgG and IgM in the seminal plasma of men with normospermia, oligozoospermia, and azoospermia.

The seminal plasma of eight males with normospermia, seven with oligozoospermia, and eight with azoospermia was examined for the presence of IgG and IgM by means of double-gel immunodiffusion. IgG was present in every seminal plasma sample. The highest titers of IgG were found in azoospermic and normospermic samples, but the lowest IgG titers were seen only in normospermic samples.

The influence of human menopausal gonadotropin, natrium fluoride and cyproterone acetate on the spermatogenesis in immature rats.

Human menopausal gonadotropin (HMG), natrium fluoride (NaF) and cyproterone acetate (CYA) were applied to immature male rats between the 26th and 32nd day of life and histological examination was performed in testes of 33rd-day-old rats. HMG treatment alone slightly influenced the spermatid completion process, while NaF evidently increased frequency of occurrence of various seminiferous tubules containing spermatids. CYA alone damaged the spermatid completion process (especially the cap-phase of spermiogenesis), produced a degeneration of meiotic spermatocytes, and decreased the tubular diameter.