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At least 289 records · Page 16Linked to original sources
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↗
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↗
PubMed1991

[Arteriographic diagnosis of a tumor arising from an undescended testis].

A case with a tumor developed in an undescended testis diagnosed by arteriography is shown. Radiological diagnostic procedures in the diagnosis of cryptorchism are discussed. It is established that selective testicular arteriography is of great value in the preoperative diagnosis of an intra-abdominally located tumor developed in an undescended testis even in the area of modern high resolution non invasive imaging modalities.

Adult↗
PubMed1991

Transgenic mice demonstrate a testis-specific promoter for angiotensin-converting enzyme.

There are two isozymes of angiotensin-converting enzyme (ACE), one produced by somatic tissues and a smaller protein synthesized by developing spermatozoa (testis ACE). To investigate the molecular control of testis ACE, we generated mice transgenic for a construct containing a putative testis-specific ACE promoter linked to the Escherichia coli reporter gene encoding beta-galactosidase. The transgenic mice express beta-galactosidase protein and RNA only within the testis. Histochemical analysis of the transgenic mice shows co-localization of beta-galactosidase protein and endogenous ACE within elongating spermatozoa. These studies demonstrate that transcription of testis ACE is controlled by a strong intragenic testis-specific promoter that is contained within a 698-base pair fragment immediately upstream from the transcription start site of testis ACE. Characterization of the testis ACE promoter may provide insights into the molecular mechanisms controlling cell stage-specific gene expression in the male germ line.

Animals↗
PubMed1989

Quantitation of testicular and somatic cytochromes c in testis and somatic tissues from developing rats.

By combining chromatographic and spectral procedures, simple and quantitative assays for somatic cytochrome c (cyt cs) and testicular cytochrome c (cyt ct) in crude animal tissue extracts were developed. Using this assay procedure, limited developmental studies of cyt ct and cs were performed with tissue extracts of 27-, 58-, and 85-day-old rats. Specific contents of cyt cs in somatic tissues (i.e., micrograms of cyt c/g of tissue) of these three age groups did not show significant variations. However, the amounts of both cyt ct and cs in testis were markedly increased as the rats approached maturity. Increasing cyt ct/cyt cs ratios as the rat developed to maturity suggest that expression of cyt ct is preferentially required for specific function of testis. Application of both molecular biological techniques and this assay (for holo-cyt ct) should be useful to study the overall regulation of the expression of cyt ct in testis.

Aging↗
PubMed1975

Androgen binding protein as a biochemical marker of formation of the blood-testis barrier.

Androgen binding protein (ABP) was measured during postnatal development in normal and irradiated rats to determine whether development of a blood-testis barrier and formation of a continuous lumen from testis to epididymis is correlated with entry of ABP into the caput epididymis. ABP is found in normal testis as early as 14 days postnatally (0.2 pmol/mg), at which time no blood-testis barrier is observed by the peroxidase perfusion technique. Previous findings have shown a close correlation of blood-testis barrier development and lumen formation. Indeed, ABP is not detectable in the epididymis until 18-20 days of age (1.0 pmol/mg) at which time blood-testis barrier formation and lumen development is complete. Whole body irradiation (125 rads) of pregnant rats at 19-20 days of gestation produces male offspring with seminiferous tubules remarkably free of germinal epithelium and containing essentially only Sertoli cells. These Sertoli cell-enriched (SCE) testes produce normal amounts of ABP between 14 and 21 days postnatally. However, between 21 and 30 days of age the specific activity of ABP is significantly higher in the SCE tests (2.8 pmol/mg protein) than in normal testis (0.5 pmol/mg protein). In the SCE testis neither blood-testis barrier development nor lumen formation are complete until 30 days of age, at which time ABP is first detectable in epididymis of the irradiated rat. Thereafter there is a gradual decline of ABP in the SCE testis-and a dramatic increase in the epididymis. NIH-FSH-S-10 (200 mug/rat) injected SC into 14-day-old normal rats stimulated ABP in the testis from control levels of 0.15 pmol/mg to 1.46 pmol/mg within 4 h after injection. However, no ABP was detectable in the epididymis of either the control or the FSH-stimulated rats. These findings suggest that entry of ABP into caput epididymis is an index of blood-testis barrier formation and lumen development.

Androgens↗
PubMed1981

The influence of neonatal orchiopexy upon the testis in persistent Müllerian duct syndrome.

We report on a patient with persistent müllerian duct syndrome and normal external genitalia who had embryonal cancer of the testis 16 years after neonatal bilateral orchiopexy. In previous cases the testes of these patients have not been considered predisposed to form tumors. However, the occurrence of a testis tumor has been reported in 8 patients with this syndrome. The specific factors resulting in tumor formation in such patients are uncertain. Until they are clarified we suggest that these patients should be observed carefully for the possible development of testis tumor.

Adolescent↗
PubMed1987

Isolation and partial characterization of basic fibroblast growth factor from bovine testis.

A basic fibroblast growth factor (FGF) has been purified to homogeneity from bovine testis, using ammonium sulfate precipitation of the crude extract followed by three chromatographic steps, involving cation-exchange, heparin-Sepharose, and reversed-phase HPLC. Gas-phase sequence analysis showed the amino-terminal amino acid sequence of the isolated polypeptide as His-Phe-Lys-Asp-Pro-Lys-Arg-Leu-Tyr-, which is identical to the amino-terminal of the (16-146) fragment of basic FGF previously characterized from corpus luteum, adrenal, and kidney. The purified FGF was shown to have the same biological activity as that of basic FGF (1-146). This finding suggests that basic FGF is present in testis and may act as a local regulator of testicular function. In addition, testicular FGF might play an important role in spermatogenesis and/or the development of testis.

Amino Acid Sequence↗
PubMed1993

Testicular cancer.

Despite the overall cure rate now in excess of 90%, innovation in management of germ cell tumors continues. The report that 80% of patients with extragonadal germ cell tumors have either carcinoma in situ or atrophic tubules as evidence of tumor rejection emphasizes the need to investigate the testis in patients with undiagnosed primary cancer because even today treatment delay is worsening prognosis. The evidence that testicular atrophy is a precursor of malignancy may explain why testis cancer has increased while normal sperm count has fallen over the past 50 years and why there is an association between exposure during service in Vietnam to agents that damage spermatogenesis and development of testis cancer. The improved prognostication from analysis of large databases and salvage with high-dose chemotherapy and bone marrow rescue are giving confidence to explore new innovations, eg, carboplatin instead of cisplatin. In addition, as the database on patients with stage I disease on surveillance enlarges, so does interest in adjuvant chemotherapy, encouraging the search for better markers to predict poor response. Linkage between overproduction of the tumor marker lactate dehydrogenase-1 and the increased copy number of the isochrome 12p in the tumor may be of use in this respect. Reports that germ cell tumor patients exposed to etoposide, eg, leukemic, lung, and ovarian cancer patients, can develop an acute myeloid leukemia with a marker on chromosome 11 are tempering enthusiasm for its use in adjuvant therapy. However, the observation that radiotherapy or chemotherapy may reduce second testis tumor incidence more effectively than surgery does encourages more detailed exploration of the results of adjuvant treatment.

Dysgerminoma↗