Androgen receptor signalling in peritubular myoid cells is essential for normal differentiation and function of adult Leydig cells.

Testosterone synthesis depends on normal Leydig cell (LC) development, but the mechanisms controlling this development remain unclear. We recently demonstrated that androgen receptor (AR) ablation from a proportion of testicular peritubular myoid cells (PTM-ARKO) did not affect LC number, but resulted in compensated LC failure. The current study extends these investigations, demonstrating that PTM AR signalling is important for normal development, ultrastructure and function of adult LCs.

Germ cell transplantation in felids: a potential approach to preserving endangered species.

With the exception of the domestic cat, all members of the family Felidae are considered either endangered or threatened. Although not yet used for this purpose, spermatogonial stem cell (SSC) transplantation has a high potential to preserve the genetic stock of endangered species. However, this technique has not previously been established in felids.

Coinfection by HTLV-I/II is associated with an increased risk of strongyloidiasis and delay in starting antiretroviral therapy for AIDS patients.

Objective: To compare the clinical characteristics and outcomes of HIV-1-HTLV-1 coinfected patients, in Bahia, Brazil.

Methods: Retrospective, comparative study.

Results: Among a total of 123 consecutive HIV infected patients, 20 men (20.

Pancreatic heterotopias: clinicopathological analysis of 18 patients.

Objective: To analyze the clinical and pathological features of heterotopic pancreatic tissue in abdominal digestive organs.

Methods: We retrospectively studied 18 patients with histologically diagnosed heterotopic pancreas. Clinical and histopathologic data were reviewed.

Selective ablation of the androgen receptor in mouse sertoli cells affects sertoli cell maturation, barrier formation and cytoskeletal development.

The observation that mice with a selective ablation of the androgen receptor (AR) in Sertoli cells (SC) (SCARKO mice) display a complete block in meiosis supports the contention that SC play a pivotal role in the control of germ cell development by androgens. To delineate the physiological and molecular mechanism responsible for this control, we compared tubular development in pubertal SCARKO mice and littermate controls. Particular attention was paid to differences in SC maturation, SC barrier formation and cytoskeletal organization and to the molecular mediators potentially involved.

Spermatogonial stem cell niche and spermatogonial stem cell transplantation in zebrafish.

Background: Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis, and reside within a specific microenvironment in the testes called "niche" which regulates stem cell properties, such as, self-renewal, pluripotency, quiescence and their ability to differentiate.

Methodology/principal Findings: Here, we introduce zebrafish as a new model for the study of SSCs in vertebrates. Using 5'-bromo-2'-deoxyuridine (BrdU), we identified long term BrdU-retaining germ cells, type A undifferentiated spermatogonia as putative stem cells in zebrafish testes.

Postnatal testis development, Sertoli cell proliferation and number of different spermatogonial types in C57BL/6J mice made transiently hypo- and hyperthyroidic during the neonatal period.

The role of thyroid hormones in testis structure and function has been fairly well studied in laboratory rodents. However, there are no comprehensive data in the literature for mice regarding the effects of transiently induced neonatal hypo- and hyperthyroidism on testis and spermatogonial cell development from birth to adulthood. Our goals were to evaluate the effects of propylthiouracil (PTU) and triidothyronine (T3) on Sertoli cell proliferation/differentiation and to correlate these events with the evolution of the spermatogenic process, tubular lumen formation, blood vessel volume density, and size and number of different spermatogonial types.

Factors associated with prenatal care and seeking assistance in public hospitals in Vitória, Espírito Santo, Brazil.

Adequate prenatal care provides an opportunity for counseling and reducing the complications associated with pregnancy and delivery. Our objective was to describe the demographic, behavioral, and clinical profile of the pregnant women hospitalized at public maternity hospitals and to identify factors associated with six or more prenatal consultations in Vitória, Brazil. A cross-sectional study of 1,380 women was conducted in public maternity hospitals in Vitória, Brazil.

A new and fast technique to generate offspring after germ cells transplantation in adult fish: the Nile tilapia (Oreochromis niloticus) model.

Background: Germ cell transplantation results in fertile recipients and is the only available approach to functionally investigate the spermatogonial stem cell biology in mammals and probably in other vertebrates. In the current study, we describe a novel non-surgical methodology for efficient spermatogonial transplantation into the testes of adult tilapia (O. niloticus), in which endogenous spermatogenesis had been depleted with the cytostatic drug busulfan.

TGF-beta1 system in Leydig cells. Part II: TGF-beta1 and progesterone, through Smad1/5, are involved in the hyperplasia/hypertrophy of Leydig cells.

Several reports indicate that transforming growth factor beta1 (TGF-beta1) participates in the regulation of cell cycle progression. In this work, we analyzed the in vitro effect of TGF-beta1 on Leydig cell proliferation markers and the in vivo effect of this cytokine in Leydig cell hyperplasia/hypertrophy. The in vitro effect of TGF-beta1 (1 ng/ml) plus progesterone (10(-6) M) on purified Leydig cells from 3 week-old mice increased the immunocytochemically detected PCNA and stimulated the phosphorylation of Smad 1/5.

Prenatal plus postnatal exposure to Di(n-Butyl) phthalate and/or flutamide markedly reduces final sertoli cell number in the rat.

Androgens may be important regulators of Sertoli cell (SC) proliferation perinatally, with implications for the testicular dysgenesis syndrome (TDS) hypothesis. Fetal exposure of rats to 500 mg/kg . d di(n-butyl) phthalate (DBP) reduces fetal testosterone production and SC number at birth, but SC number recovers to normal by postnatal d (Pnd)25.

Duration of spermatogenesis and spermatogenic efficiency in 2 large neotropical rodent species: the agouti (Dasyprocta leporina) and paca (Agouti paca).

The agouti (Dasyprocta leporina) and paca (Agouti paca) are among the largest extant rodent species. Although these species have considerable economic potential, there are few reports in the literature concerning male reproductive biology in sexually mature agoutis and pacas. The objectives of the present study were to perform detailed stereologic and histologic analyses of the testis and estimate spermatogenic cycle length in these 2 Neotropical rodent species as well as to compare the data with those from other well-studied rodent members of the Hystricomorpha and Myomorpha suborders.

Postnatal somatic cell proliferation and seminiferous tubule maturation in pigs: a non-random event.

Although seminiferous tubule maturation in horses begins in the central area of the testis, this process is thought to occur randomly throughout the testis in most mammals. Studies in our laboratory revealed that the establishment of spermatogenesis may not be a synchronous event in the testicular parenchyma of pigs. The objectives of the present study were to evaluate the pattern of seminiferous cord/tubule maturation and the morphological and functional characteristics of testicular somatic cells during postnatal development in three regions of the pig testis: a) near the tunica albuginea (TA); b) in the transitional area between the seminiferous tubules and mediastinum (TR); and c) in the intermediate area (ID) between the TA and TR.

Protective effect of carbon dioxide against bacterial peritonitis induced in rats.

Background: Carbon dioxide (CO(2)) has been used in the food industry as an antimicrobial agent. This study aimed to investigate whether CO(2) pneumoperitoneum might act similarly as an antimicrobial agent in the infected peritoneal cavity.

Methods: Peritonitis was induced in 58 rats by intraabdominal injection of an Escherichia coli inoculum (6 x 105 colony-forming units [CFU]/ml).

Spermatogenic efficiency in the spiny rat, Trinomys moojeni (Rodentia: Echimyidae).

The spiny rat (Trinomys moojeni) is a rodent found in the Atlantic Forest, which is considered one of the most diverse and threatened biomes in the world. Knowledge on reproductive biology and physiology is critical to conservation and species management, allowing the prevention of extinction and the use of males in natural and artificial reproduction programs. The main objectives of the present study were to investigate the testis structure as well as spermatogenic and Sertoli cell efficiency in the spiny rat captured in the Caraça Natural Reserve, a fragment of the Atlantic Forest located in the State of Minas Gerais, Brazil.

Heavy episodic drinking and alcohol consumption in French colleges: the role of perceived social norms.

Background: The effect of normative perceptions (social norms) on heavy episodic drinking (HED) behavior is well known in the U.S. college setting, but little work is available in other cultural contexts.

Testis stereology, seminiferous epithelium cycle length, and daily sperm production in the ocelot (Leopardus pardalis).

Similar to most wild felids, the ocelot (Leopardus pardalis) is an endangered species. However, knowledge regarding reproductive biology of the ocelot is very limited. Germ cell transplantation is an effective technique for investigating spermatogenesis and stem cell biology in mammals, and the morphologic characterization of germ cells and knowledge of cycle length are potential tools for tracking the development of transplanted germ cells.

[Prevalence of syphilis and HIV using rapid tests among parturients attended in public maternity hospitals in Vitória, State of Espírito Santo].

The aim of this study was to describe the prevalence of syphilis and HIV among parturients attended at public maternity hospitals in Vitória, Espírito Santo. Between January and May 2007, interviews were conducted to obtain demographic, behavioral and clinical data. The subjects were tested for HIV using a rapid test, ELISA and the indirect fluorescence assay; and for syphilis using a rapid test, VDRL and MHA-TP.

Complete genome sequence of the sugarcane nitrogen-fixing endophyte Gluconacetobacter diazotrophicus Pal5.

Background: Gluconacetobacter diazotrophicus Pal5 is an endophytic diazotrophic bacterium that lives in association with sugarcane plants. It has important biotechnological features such as nitrogen fixation, plant growth promotion, sugar metabolism pathways, secretion of organic acids, synthesis of auxin and the occurrence of bacteriocins.

Results: Gluconacetobacter diazotrophicus Pal5 is the third diazotrophic endophytic bacterium to be completely sequenced.

[Methodology for the use of chat in nursing].

The purpose of this study was to describe the methodology of the use of chat for real-time communication in a group of nursing research. The role of coordinator understands the dimensions of planning, mediation and technology. Each dimension can determine the success or failure of communication.

Spermatogenic cycle length and sperm production in a feral pig species (collared peccary, Tayassu tajacu).

Although the collared peccary (Tayassu tajacu) is found throughout the Americas, with a high potential for domestication and commercial exploitation, there are few data on the reproductive biology of this mammalian species. The aim of the present study was to investigate testis structure, spermatogenic cycle length, Sertoli cell efficiency, and spermatogenic efficiency. Twelve adult peccaries were used for biometrical, histological, and stereological analyses; 3 of these peccaries received intratesticular injections of (3)H-thymidine for the determination of the duration of spermatogenesis.

Duration of spermatogenesis in the bullfrog (Lithobates catesbeianus).

The bullfrog (Lithobates catesbeianus) has substantial economic importance and has also been used as an experimental model for biological studies in the fields of pharmacology, medicine, and reproductive biology, especially studies addressing gametogenesis. However, there is a lack of comprehensive information in the literature regarding testis structure and function in this amphibian. The main objective of the current study was to estimate the duration of the various phases of spermatogenesis in this vertebrate.

The seminiferous epithelium cycle and its duration in different breeds of dog (Canis familiaris).

Testis structure and function in dogs are relatively poorly investigated. The aim of the present study was to carry out a comparative investigation of the stages of the seminiferous epithelium cycle and its duration in different breeds of dog. Fifty-six sexually mature dogs (mongrel, n = 12; pinscher, n = 12; beagle, n = 5; American pit bull, n = 9; poodle, n = 12; and Labrador retriever, n = 6) were analysed.

The role of angiotensin-(1-7) receptor Mas in spermatogenesis in mice and rats.

Evidence regarding the components of the renin-angiotensin (Ang) system suggests that this system plays an important role in male reproduction. However, there are few data available in the literature on the effects of Ang-(1-7) on the male reproductive system. The present study investigated the effects of the genetic deletion and chronic blockage of Ang-(1-7) receptor Mas on spermatogenesis and male fertility.