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At least 307 records · Page 17Linked to original sources
PubMed1992

False-negative biopsy for testicular intraepithelial neoplasia.

A routine biopsy of the contralateral testis obtained during orchiectomy for embryonal carcinoma in a 26-year-old patient was negative for testicular intraepithelial neoplasia (TIN; carcinoma in situ of the testis). However, a rebiopsy that was taken because of unexplained elevation of alpha-fetoprotein 15 months later proved to be positive for TIN. Six previously reported cases of false-negative testicular biopsies obtained during a search for TIN are reviewed. In the light of several thousands of biopsies performed world-wide to date, the number of false-negative biopsies is probably very low. Although TIN is obviously not randomly dispersed throughout the testis in all patients, a routine biopsy of the contralateral testicle in patients with testis cancer remains a valuable tool for early detection of bilateral testicular tumors.-cal distribution of TIN in testes removed for this lesion. Their results suggested that after puberty TIN is usually randomly dispersed throughout the testicle. Support for this concept was recently given by Mumperow et al. (1992). These authors examined tumor-bearing testes and they did not find differences in the presence of TIN in biopsies taken from a location close to the tumor and taken from a location distant from the tumor. Thus, one single biopsy is regard to be representative for the entire testis and one biopsy taken after puberty is also assumed to be reliable for predicting whether the testis will ever develop cancer (Berthelsen and Skakkebaek 1981 a). Conversely, if the biopsy is negative for TIN, a future tumor manifestation in the testicle examined is not expected according to this theory (Skakkebaek et al. 1987). Taken together, the concept of TIN would constitute an ideal avenue for the early detection of testis cancer in high-risk populations with the biopsy being a safe means of discriminating between individuals who will or who will not develop testis cancer.

Adult↗
PubMed1978

The development of Schistosoma haematobium in the hamster.

The in vivo development of Schistosoma haematobium in the hamster was studied. Six stages of development were distinguished on the basis of morphological and histochemical criteria. Schistosomula reached the lung (stage 1) on day three post-infection, with maximum concentrations on day nine. Gut formation occurred in the second stage at day 18. In stage 3 'Organogeny' (day 24) males developed one testis and females a narrow uterus. Pairing and the development of males with sperm-containing testes and females with an ovary characterize stage 4 (day 28). In stage 5 (day 53) vitelline follicles begin to develop in the females. The final stage, oviposition, occurred on days 61-63 and was characterized by the appearance of fully developed eggs in the uterus.

Animals↗
PubMed1995

Expression of mRNA and immunocytochemical localization of inhibin alpha- and inhibin beta A-subunits in the fetal sheep testis.

In order to investigate the ontogeny of gonadal inhibin production in the male fetal sheep, testes were collected from male fetuses at days 70, 100, 130 and 140 of gestation (term = 145 days). The expression and localization of inhibin alpha- and inhibin beta A-subunit mRNA and protein were evaluated using in situ hybridization and immunocytochemistry. The expression of inhibin alpha-subunit mRNA was localized within the seminiferous cords of the developing fetal testis and progressively increased with gestational age. Immunostaining corresponding to immunoreactive inhibin alpha-subunit was detected in Sertoli cells within the seminiferous cords at days 100, 130 and 140 of gestation. In addition, immunostaining was detectable in a small proportion of Leydig cells. No expression of inhibin beta A-subunit mRNA or immunoreactivity was detected in any testicular tissue at any stage of gestation. These data show that the Sertoli cells of the developing fetal sheep testis have the capacity to produce inhibin alpha-subunit by day 100 of gestation and that production increases during late gestation.

Animals↗
PubMed1989

Corticosteroid 11 beta-dehydrogenase in rat testis.

Corticosteroid 11 beta-dehydrogenase, the enzyme that catalyzes the oxidation of the biologically active steroid cortisol to its inactive metabolite cortisone, is present in testis. Since excess cortisol in men and other mammals and excess corticosterone in rodents cause physiological abnormalities including abnormal testicular function, it was pertinent to study the cellular distribution of 11 beta-dehydrogenase in the testis. Purified antiserum directed against homogeneous rat 11 beta-dehydrogenase was used to localize the enzyme in the developing rat testis. With immunofluorescence, the enzyme was not detectable in fetal testis or in the testis of young male rats until the 26th day of development. A few interstitial cells were stained in the testis of 26-day-old animals. In the testis of 31-day-old rats many cells in the interstitium were positive. In adult animals the entire interstitial region displayed bright fluorescence. Depleting animals of germ cells did not abolish the fluorescence. The appearance of this enzyme correlates temporally with the postnatal increase in Leydig cell number and the developmental rise in serum testosterone. We suggest that 11 beta-dehydrogenase of Leydig cells protects the testis from the deleterious effects of cortisol.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1983

Sexual development, maturation, and behavior.

The Y chromosome directs the primitive gonad to develop into a testis. Without a Y chromosome an ovary will develop, but that ovary will not be normal unless two X chromosomes are present. Active intervention is needed for male differentiation; internal male structures will not be found unless sufficient and effective testosterone is secreted by the immature testis to develop the wolffian duct system into the internal male reproductive tract. The testis must also secrete mullerian regression factor to cause the demise of the internal female duct structures. Finally, enough 5-alpha-reductase activity must be present to convert testosterone into dihydrotestosterone for the normal virilization of the male external genitalia. Without testosterone or its receptor sites, without dihydrotestosterone, and without mullerian regression factor, the reproductive system is female. Early in life, a child assumes both a gender identity (an awareness of what sex he or she belongs to) and a gender role (behavior deemed to be more or less characteristic of one sex or the other). As puberty is passed, sexual orientation becomes more obvious, although the development of that orientation has probably been in the making since early childhood. Early developmental hormone milieu and social environment undoubtedly all play a role in subsequent sexual behavioral patterns, but the extent to which each of these impacts upon that behavior still remains unknown.

Adolescent↗
PubMed1995

Development of the gubernaculum and processus vaginalis in freemartinism: further evidence in support of a specific fetal testis hormone governing male-specific gubernacular development.

BACKGROUND: Freemartinism occurs in some species of ruminants and affects most female bovine fetuses in heterosexual, multiple pregnancies owing to fusion of the chorionic blood circulations soon after implantation. Maldevelopment of the ovaries and Müllerian ducts have been described and recognized as resulting from exposure of their respective primordia to an excess of anti-Müllerian hormone. The present study aimed to analyse the prenatal growth and development of the gubernaculum in freemartins to find out its possible affliction through foetal testis hormones derived from their male co-twin. METHODS: Histological sections of young and drawings and photographs of further developed freemartins and control male and female bovine foetuses were analysed. The specimens had been collected earlier for analysis of the time course of male and female gonadal and genital development and its impairment associated with freemartinism. RESULTS: The gubernaculum of 35-40-day-old male and female fetuses was in the initial stage of development and of similar appearance in all specimens. Gubernacula of 60-70-day-old male fetuses differed from those of females of similar age in various respects: the male gubernaculum size was larger and extension of the processus vaginalis was deeper. Freemartins showed an intermediate development with some individuals resembling male and others resembling female agemates. During further development, gubernacula in males developed into muscular cremaster sacs, whereas those in females generally did not develop beyond the size and structural complexity of 70-day-old foetuses. Beyond day 70 of fetal life, gubernaculum development in freemartins definitely showed male characteristics with respect to size and growth of a processus vaginalis with a cremaster muscular wall. The male-like pattern of the outgrowth of the processus vaginalis changed during the second half of prenatal life. Rather than its further deepening as in males, this structure became inverted to become emerging as a papilla-like structure from the inguinal abdomen bottom. An explanation is proposed for this unprecedented inversion, taking into account: (1) the faster and higher reaching rightsided ascent of the kidneys and gonads, (2) the femalelike outgrowth of the cranial gonadal suspensory ligaments, and (3) the absence of scrotum development. The ovaries and mesonephric remnants in developing freemartins, during their ascent together with the kidneys while remaining attached to the bottom of the developing processus vaginalis sacs via the gubernaculum ligament, are proposed to act together to pull up the bottom of the processus vaginalis sacs. From this action, "inverted hernia sacs" result as the irreversible consequence. CONCLUSION: The data support the concept that foetal testes act, via as an yet unidentified third hormone, to establish malelike development of gubernacula into muscular cremaster sacs. Further work is required to reveal the identity of this hormone. Furthermore, the apparent similarity of the freemartins' inverted processus vaginalis sacs and the fetal rodents' gubernacular cones suggests that the ruminants' and rodents' processus vaginalis are essentially similar structures. Thus there is no longer an urgent need to distinguish between two different types of gubernaculum development and testis descent in rodents and ruminants, respectively, and involving or not fetal gubernacular cones. The present observations may thus contribute to the development of a unified hypothesis for sexually dimorphic development of the gubernaculum throughout the mammalian class.

Androgens↗
PubMed1985

Canine cryptorchism and subsequent testicular neoplasia: case-control study with epidemiologic update.

A retrospective study of 2,912 cryptorchid dogs identified 14 breeds with significantly high risk. Among six distinct closely interrelated breed groups (e.g., toy, miniature, and standard poodles), the risk in the smaller breed was always greater than that in the larger relative, suggesting that genetically influenced maldescent could be, in part, related to physical size or the rate of growth of the involved structures. Testicular tumors were diagnosed in 5.7% of the cryptorchid dogs; half had only Sertoli cell tumors, one-third had only seminomas. The relative risk for Sertoli cell tumor or seminoma was not directly related to a familial risk for cryptorchism. Using the health experience of a control population composed of male dogs with anal sac disease (N = 4,184), there is an estimated relative risk of 9.2 in cryptorchid dogs to develop a testis tumor (95% confidence interval, 5.9-14.3) and 4.2 in dogs with inguinal hernia (95% confidence interval, 1.8-9.5). Considering that the anatomical development of the genital tract, testis descent, and tunic relationships in dog are very similar to that in man, and that the associations of cryptorchism and inguinal hernia with testis neoplasms are also similar, the dog should be an excellent model system to further investigate the causes of human cryptorchism.

Animals↗
PubMed1994

Mouse A-myb encodes a trans-activator and is expressed in mitotically active cells of the developing central nervous system, adult testis and B lymphocytes.

C-myb encodes a transcriptional activator that is essential for the development of the hematopoietic system but appears to lack major roles in non-hematopoietic cells. The identification of two conserved myb-related genes, designated A-myb and B-myb, has raised the possibility that these genes are functional equivalents of c-myb in non-hematopoietic cells. Here, we report the isolation and preliminary characterization of the mouse A-myb gene. Mouse A-myb maps to the proximal region of chromosome 1 and encodes a transcriptional activator with properties similar to those of the c-myb and v-myb proteins. During embryo-genesis A-myb is predominantly expressed in several regions of the developing central nervous system (CNS) and the urogenital ridge. Expression in the CNS is confined to the neural tube, the hindbrain, the neural retina and the olfactory epithelium, and coincides with the presence of proliferating immature neuronal precursor cells. In the adult mouse, A-myb is expressed during the early stages of sperm cell differentiation and in B lymphocytes located in germinal centers of the spleen. Taken together, these results suggest a role for A-myb in the proliferation and/or differentiation of neurogenic, spermatogenic and B-lymphoid cells.

Amino Acid Sequence↗
PubMed1987

Hyperplasia of spermatic cord nerves: a sign of testicular absence.

The comparative histologic study of the spermatic cord in the absence of testis, epididymis-testis separation, and normal development of both testis and epididymis, revealed that there is nerve trunk hyperplasia and hypertrophy in absence of the testis. This finding may greatly aid the diagnosis of testicular absence in the management of impalpable testes.

Cryptorchidism↗
PubMed1988

Autosomal genes involved in mammalian primary sex determination.

Beginning with findings made during the late 1950s and early 1960s, evidence continues to accumulate in support of the hypothesis that the mammalian Y chromosome carries a gene that induces the undifferentiated foetal gonad in XY individuals to develop as a testis. Recently a DNA sequence has been isolated from the human Y chromosome that appears to be the hypothesized Y-linked testis-determining gene, and advances have also been made toward identifying genes that interact with the Y-linked testis-determining (Tdy) gene to initiate testis formation. These loci have been identified in specific stocks of mice carrying the mutant Thp or TOrl allele at the T locus located on chromosome 17, and in crosses involving the transfer of a Y chromosome from two populations of Mus domesticus into the genomes of specific inbred strains of mice. The data in both cases support the hypothesis that there are several loci involved in testis determination and that abnormal interaction of these loci disrupts initiation of testis determination, resulting in development of ovarian tissue in XY individuals.

Animals↗
PubMed1995

The effect of ultrasound exposure in utero on the development of the fetal mouse testis: adult consequences.

The effects of exposure in utero to 1 MHz, continuous-wave ultrasound on adult growth and testicular development in the mouse was investigated. The spatial peak temporal average intensity (ISPTA) employed ranged from 1 to 10 W/cm2, with exposure durations (t) of 200 s to 20 s. Exposures were made on days 9, 12 or 15 of gestation. Results showed an increase in postpartum deaths, an increase in the number of stillbirths, and a decrease in litter size when I2 t > or = 1125 W2 s/cm4, such that there was significant loss of pups. Birthweights of pups from nearly all dosage groups was significantly lower than that of the sham or cage control groups. Results also showed that males exposed to ultrasound in utero had decreased testis size and decreased daily sperm production ranging from 9% to 30%. This study showed that ultrasound exposure in utero is capable of disrupting fetal development and having potential subsequent effects on fertility in the adult male.

Animals↗
PubMed1985

[Effect of an analog of proline (L-azetidine-2-carboxylic acid) on in vitro differentiation of the rat fetal testis].

The initial stages of the development of the seminiferous cords involve the differentiation and the aggregation of primordial Sertoli cells opposite to cells which acquire a mesenchymal-like aspect. The hypothesis that the development of the seminiferous cords depends on epithelial-mesenchymal relations between the two cell types was submitted to experimental test. Male gonadal primordia of rat fetuses were cultured in vitro in a synthetic medium containing the proline competitor, L-Azetidine-2-Carboxylic Acid. This drug is known to disturb the synthesis and secretion of collagen and proline-containing proteins. It prevents testicular organogenesis or destroys it if it has begun. It suppresses the expression of laminin and fibronectin in the gonadal primordium. These observations are taken as evidence that cellular correlations of the epithelial-mesenchymal type play a role in the development of the testis as they do in that of other organs.

Animals↗
PubMed1986

[Seminoma of testis. Analysis of failures and development of therapeutic strategies. Apropos of a Lyons series of 117 cases].

From Jan.61 to Dec.81, 117 patients with seminoma of testis were treated in the Leon Berard Centre, Lyon. All had undergone lymphography during investigation of possible extension, 19 were treated with 200 KV up 1966, 64 with Cobalt up to 1978 and 29 with photons x of 18 MV since that date. From 1979 adjuvant chemotherapy has always included cisplatinum. The 5 years survival rate was 95% of stage I (51/54 cases), 72% of stage II (26/36 cases) and 1/7 of stage III. Unsuccessful treatment of neoplasm was noted in 23 patients, in 80% of cases during the first two years and involving mainly pulmonary metastases. Three patients had mediastinal metastases while recovery surgery was possible in 4 cases. Three fatal iatrogenic complications were observed. Since the use of high energies, particularLy x beams of 18 MV there has been almost total absence of radic complications. Therapy now proposed is as follows: stage I: surgery plus radiotherapy; stage II A-B: surgery and irradiation avoiding mediastinum; stage II C and III: primary chemotherapy.

Adult↗
PubMed1994

Carcinoma in situ of the testis followed by an overt malignant teratoma of the testis within 12 months.

A case of bilateral metachronous testicular non-seminomatous germ cell tumour (NSGCT) is presented. The second tumour was preceded by carcinoma in situ, diagnosed at the time of the first orchidectomy. The patient was placed under active surveillance and 1 year later the second testis tumour developed. A second orchidectomy was performed and testosterone replacement begun. Carcinoma in situ of the testis is discussed.

Adult↗
PubMed1993

Localization of transforming growth factor beta 1 and beta 2 during testicular development in the rat.

The transforming growth factor beta s (TGF beta s) affect the metabolic activities of the somatic cells of the testis. Sertoli cells, peritubular/myoid cells, and germ cells contain mRNA for TGF beta 1 and/or TGF beta 2. We have used immunohistochemical techniques to determine, in vivo, when TGF beta 1 and TGF beta 2 are present in the rat testis during development and have identified the precise localization of these growth factors. The most pronounced changes in TGF beta immunoreactivity occurred during spermatogenesis. TGF beta 1 predominated in spermatocytes and early round spermatids, but as the spermatids elongated around stages VIII-IX of the cycle, the TGF beta 1 levels declined. TGF beta 2 was undetectable in spermatocytes and early round spermatids, but as spermiogenesis progressed, around stages V-VI, the spermatids rapidly acquired TGF beta 2. The intense staining for TGF beta 2 was maintained as the spermatids elongated. TGF beta 1 immunoreactivity was detected in Sertoli cells throughout testicular development. TGF beta 2 was found in fetal Sertoli cells, but became undetectable rapidly after birth. In fetal animals the Leydig cells contained TGF beta 1 and TGF beta 2; after birth TGF beta 1 persisted whereas TGF beta 2 became undetectable in the Leydig cells. Prior to puberty, TGF beta 1 and TGF beta 2 were absent in a portion of the Leydig cells; when the adult stage was reached, TGF beta 1 was no longer detectable and TGF beta 2 staining was faint to absent. In conclusion, our novel findings show that TGF beta 1 and TGF beta 2 are present in vivo in testicular cells at clearly defined stages of their differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Gonadal dimorphism explained as a dosage effect of a locus on the sex chromosomes, the gonad-differentiation locus (GDL).

In human somatic cells bearing two X chromosomes, one X is genetically inactivated throughout most of its length, whereas in cells with one X and one Y both sex chromosomes are active (with the exception of the constitutive heterochromatin of the Y that is inert). The vast base of information concerning normal and abnormal human sexual development that has accumulated since the advent of human cytogenetics 3 decades ago can be integrated by the following hypothesis: Homologous gonad-differentiation loci (GDLs) exist on the X and Y. The GDLs are strictly sex-linked; that is, normally they do not recombine during spermatogenesis, so that considerable divergence in DNA sequence doubtless has occurred between the locus on the X and the locus on the Y. The abundance of their evolutionarily conserved product--a substance still to be identified--determines the path of differentiation that the indifferent gonadal anlage of the early embryo will take: if only one GDL is transcribed, the case when two X chromosomes are present, ovary will develop; if two GDLs are transcribed, the case when a Y is present along with an X, testis will develop. By implication, facultative X inactivation is an integral and essential component of the system adopted in mammalian evolution for accomplishing gonadal--viz., sexual--dimorphism.

Chromosome Mapping↗
PubMed1994

Differential distribution of the alpha 6 subunit of integrins in the development and sexual differentiation of the mouse testis.

The distribution of the alpha 6 subunit of integrins in the development and sexual differentiation of mouse testis was analyzed by light and electron microscopy during the embryonic, fetal and early postnatal periods. At the pregonadal phase only the epithelial cells of the mesonephric duct and of the distal mesonephric tubules showed a reaction to alpha 6, whereas the surface epithelium and the mesenchyme of the mesonephros were negative or contained only a rudimentary amount of the alpha 6 subunit. With the formation of the gonadal ridge and the testicular blastema, the gonadal cells became positive for the alpha 6 subunit. This expression remained in embryonic cord cells and in the vascular endothelial cells, whereas the differentiating cells of the surface epithelium, tunica albuginea, the Leydig cells, and the interstitial mesenchymal cells were negative. With the fetal and postnatal differentiation, the expression of the alpha 6 subunit gradually diminished in the cord cells, and by the prepubertal phase, alpha 6 was found only at adhesion sites between some Sertoli cells. Similar changes were seen in the mesonephric duct and tubules, and in the rete cords. The presence of alpha 6 in regions undergoing developmental cell aggregation processes and their disappearance during tissue maturation, suggest that alpha 6 plays a specific but transient role in gonadal cell adhesion necessary for the histogenetic organization of the testis. In addition to its role in developing and organizing cells, alpha 6 integrin was also a prominent component in degenerating cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗