980 resultados para Testicular Hormones


Relevância:

20.00% 20.00%

Publicador:

Resumo:

During studies of amphibian sperm cryopreservation, a new species of myxosporidean parasite (Myxozoa, Myxosporae) was observed in the testes of the Australian dwarf green tree frog Litoria fallax (Peters). Myxosporidiasis was found to have no affect on L. fallax body condition or sperm numbers. Myxobolus spores from L. fallax are morphologically distinct from Myxobolus hylae spores (infecting the sympatric Litoria aurea Lesson) and the three previously named (exotic to Australia) Myxobolus species found in anurans. Myxobolus fallax n. sp. is characterised by: pseudocyst white, spherical to ovoid, 141 x74 to 438 x337 mum in diameter (mature); plasmodium with spores loosely arranged within interior. Spores ovoid 13.4 +/- 0.5 (12.6-14.6) mum length, 9.5 +/- 0.4 (8.3-10.6) mum width, 6.8 +/- 0.4 (6.5-7.6) mum depth, 1.4 +/- 0.1 (1.3-1.6) length/width; polar capsules broadly pyriform and equal in size 4.2 +/- 0.3 (3.3-4.7) mum length, 2.4 +/- 0.2 (2.1-2.8) mum width; filament coils 7-8, wound tightly and perpendicular to the longitudinal axis of the capsule; polar filament 34 +/- 7.0 (18-50) mum length; intercapsular appendix and sutural ridge folds absent; and iodinophilous vacuole and mucous envelope lacking. In addition to this new species, data from archival samples of M. hylae are provided which show two morphologically distinct spore types. Both appeared rarely in the same pseudocysts and we cautiously retain the single species.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this tudy was to evaluate corporal and testicular development in wild boars (Sus scrofa scrofa) from birth to 12 months of age, evaluating body weight, biometric testicular parameters, and gonadosomatic index. Thirty-nine male wild boars from a commercial farm licensed by IBAMA were used in the study. The animals were weighed and assigned to 13 experimental groups. The testes were recovered through unilateral orchiectomy, weighed on an analytical balance and measured for length, width and thickness. Body weight and testicular measures increased with the age, up to 12 months, and were more accelerated in the first and ninth months. Initially the testicular growth pattern, between zero and nine months, followed the body growth, and the gonadosomatic index varied from 0.07 to 0.09%. Between 9 and 11 months, the testicular growth was superior to the body growth, and the gonadosomatic index varied from 0.09 to 0.16%. Finally, after 11 months of age, testicular and body growth had a similar behavior. In conclusion, body weight, testicular biometry, and gonadosomatic index development accelerated in the ninth month.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de Mestrado em Ambiente, Saúde e Segurança.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A displasia quística testicular é uma patologia benigna e rara, frequentemente associada a outras anomalias génito-urinárias, que se apresenta na infância sobretudo com aumento do volume escrotal, fazendo diagnóstico diferencial com situações neoplásicas e inflamatórias do testículo. Embora classicamente considerada indicação para orquidectomia, não parece haver qualquer potencial maligno, pelo que se pode argumentar uma abordagem conservadora. No entanto é importante confirmar o diagnóstico e manter vigilância para precaver a atrofia do parênquima testicular. Os autores apresentam o caso clínico de um doente com antecedentes de agenésia renal esquerda e megauretero obstructivo direito, submetido a orquidectomia no contexto de displasia quística testicular esquerda com atrofia importante do parênquima.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

AbstractDespite its infrequent occurrence, testicular schistosomiasis forming pseudo-tumors can be considered in the differential diagnosis of testicular tumors, especially in areas where the parasitic disease is endemic. In this report, we present a case of testicular schistosomiasis caused by Schistosoma mansoni and mimicking a testicular neoplasm. We describe the patterns of a testicular nodule on ultrasonography and magnetic resonance images in a 46-year-old man. The nodule was removed after a pre-operative diagnosis of a non-malignant lesion. Histology demonstrated granulomas with epithelioid macrophages and eosinophils around S. mansoni eggs within a fibrous tissue that formed a nodular structure.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: Infertility is one of the less common presenting features associated with testicular tumors. We evaluated the histologic and biochemical findings, and pregnancy outcome in patients presenting with infertility who were found to have testicular tumors. METHODS: Seven patients with infertility were found to have testicular cancer over a 15-year period. All patients had a testicular ultrasound evaluation. The indications for the ultrasound were testicular pain in 2 patients, suspicious palpable mass in 4, and to rule out the presence of germ cell neoplasia in a patient with carcinoma in situ detected on a previous biopsy. Physical exam, histological findings, hormonal levels, tumor markers, and pregnancy outcome results were recorded from the patients medical charts. RESULTS: Two men had elevated serum follicle stimulant hormone and luteinizing hormone levels, 1 of them had an abnormally low serum testosterone level. Tumor markers were normal in all patients. In 4 patients the tumor was on the right side and in 3 on the left. The histological diagnoses were seminoma (n = 5), Leydig cell tumor (n = 1), and carcinoma in situ (n = 1). Of the 7 patients, 5 underwent adjuvant radiation therapy. Two patients had sperm cryopreserved. Follow up on fertility status was available in 6 cases. One patient has established a pregnancy and 5 did not achieve a pregnancy after treatment for their cancer. CONCLUSIONS: Most of the men who have testicular cancer and male infertility have a seminona. Therefore, men who present with infertility should be thoroughly investigated to rule out such serious, concomitant diseases along with their infertility.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Estudos relacionados à obtenção e avaliação de sêmen de Tayassu tajacu são escassos, sendo necessárias pesquisas a respeito. Os objetivos do estudo foram avaliar a biometria testicular de caititus adultos cativos, testar a eficiência da eletroejaculação para obtenção de sêmen e avaliar suas características seminais ao longo do ano. Procedeu-se à eletroejaculação em oito animais adultos e as amostras de sêmen colhidas foram avaliadas quanto às características físicas e morfológicas. Os animais tinham testículo esquerdo com 3,8 ± 0,4 cm X 2,6 ± 0,3 cm e 2,3 ± 0,2 de consistência, e testículo direito com 3,8 ± 0,5 cm X 2,7 ± 0,3 cm e 2,3 ± 0,2 de consistência. A taxa de sucesso nas colheitas foi de 75,21%. O sêmen possuiu: volume 0,81 ± 0,86 mL, concentração 137,44 ± 153 x 106 sptz mL-1, pH 7,92 ± 0,73, motilidade 52,66 ± 28,79%, vigor 2,2 ± 0,8, integridade de membrana plasmática 55,84 ± 28,55%, defeitos maiores 22,87 ± 12,93%, defeitos menores 9,11 ± 5,88% e defeitos totais 31,52 ± 13,81%. Os animais apresentaram simetria testicular, a eletroejaculação se mostrou eficiente para a obtenção de ejaculados em caititus e as flutuações observadas na produção seminal não foram suficientes para caracterizá-los como animais de reprodução sazonal.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En el presente trabajo se describen las características morfohistológicas del testículo de individuos adultos (n=5) de Ceratophrys ornata (Bell, 1843) provenientes de humedales del centro de Argentina. Los mismos se procesaron mediante técnicas histológicas de rutina, se cortaron a 8 µm y las láminas obtenidas se tiñeron con hematoxilina-eosina y tricrómico de Masson. Las gónadas son órganos pares, amarillentos, alargados y contorneados de 18,58 ± 0,23 mm de largo por 1,51 ± 0,13 mm de ancho. Histológicamente se observa una delgada túnica albugínea (6,29 ± 0,83 µm) rodeando a los testículos. En su interior se hallan lóculos seminíferos que miden 240,64 ± 38,52 µm de diámetro, en ellos se distinguen cistos con células espermatogénicas en distintas etapas de desarrollo. El tejido intersticial es escaso y en él se destacan las células de Leydig y vasos sanguíneos. Las espermatogonias I son las células más grandes de la serie germinal (20,03 ± 2,27 µm); poseen la cromatina granular y de aspecto multilobular, hallándose comúnmente una por cisto, estas originan a las espermatogonias II, más pequeñas (12,06 ± 1,14 µm). Los espermatocitos I presentan la cromatina levemente condensada y son un poco más chicos que sus precedentes (11,64 ± 0,36 µm). Los espermatocitos II miden 8,85 ± 0,54 µm. Las espermátidas I son esféricas, miden 5,95 ± 0,42 µm y se agrupan en cistos redondeados. Las espermátidas II, en cambio son alargadas y no se hallan dentro de cistos, pero siguen organizadas en paquetes asociadas a células de Sertoli. Los espermatozoides son células libres hacia el centro del lóculo, alargadas, flageladas y con una notable compactación nuclear. La morfohistología de los testículos analizados muestran características macroscópicas e histológicas similares a las observadas en otras especies de anfibios anuros neotropicales, presentando todas las células del linaje espermatogénico en un mismo lóculo, lo que indicaría que presentan ciclos espermatogénicos continuos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The authors summarize the results of former works, based on the technics of parabiosis. After parabiotic union of two infantile rats, normal + castrate, the normal fellow enters into precocious puberty in about 7 days (Kallas). In the case of pairs: castrated male + normal female, the implants of testicles, or injection of maceration or aqueous extracts of testis in the castrated fellow, prevents the induction of early puberty in the normal female. In the case: castrated female + normal female, no inhibiting effect is provoked by that treatment. There is therefore a testicular hormone that regulates the hypophysis. After castration, this gland manifests a hyper-function and shows histological alterations, the chief character of these being the appearing in the anterior lobe, of the so-called castration cells, probably originated from basophile cells. Implants or injections of testis material prevent those alterations. This is a useful test; the effect is controlled by estimating the castration cells in the microscopic field. The testicular hormone that regulates the anterior lobe is probably another one, quite different from that which regulates the accessory genitalia. On account of the facts and experiments, it may be assumed that this new hormone is elaborated by the germinal epithelium of the testicles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

After peripheral nerve injury in adult mammals, reestablishment of functional connections depends on several parameters including neurotrophic factors, the extracellular matrix, and hormones. However, little is known about the contribution of hormones to peripheral nerve regeneration. Thyroid hormones, which are required for the development and maturation of the central nervous system, are also important for the development of peripheral nerves. The action of triiodothyronine (T3) on responsive cells is mediated through nuclear thyroid hormone receptors (TRs) which modulate the expression of specific genes in target cells. Thus, to study the effect of T3, it is first necessary to know whether the target tissues possess TRs. The fact that sciatic nerve cells possess functional TRs suggests that these cells can respond to T3 and, as a consequence, that thyroid hormone may be involved in peripheral nerve regeneration. The silicone nerve guide model provides an excellent system to study the action of local administration of T3. Evidence from such studies demonstrate that animals treated locally with T3 at the level of transection have more complete regeneration of sciatic nerve and better functional recovery. Among the possible regulatory mechanisms by which T3 enhances peripheral nerve regeneration is rapid action on both axotomized neurons and Schwann cells which, in turn, produce a lasting and stimulatory effect on peripheral nerve regeneration. It is probable that T3 up- or down-regulates gene expression of one or more growth factors, extracellular matrix, or cell adhesion molecules, all of which stimulate peripheral nerve regeneration. This could explain the greater effect of T3 on nerve regeneration compared with the effect of any one growth factor or adhesion molecule.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Stressful situations during development can shape the phenotype for life by provoking a trade-off between development and survival. Stress hormones, mainly glucocorticoids, play an important orchestrating role in this trade-off. Hence, how stress sensitive an animal is critically determines the phenotype and ultimately fitness. In several species, darker eumelanic individuals are less sensitive to stressful conditions than less eumelanic conspecifics, which may be due to the pleiotropic effects of genes affecting both coloration and physiological traits. We experimentally tested whether the degree of melanin-based coloration is associated with the sensitivity to an endocrine response to stressful situations in the barn owl. We artificially administered the mediator of a hormonal stress response, corticosterone, to nestlings to examine the prediction that corticosterone-induced reduction in growth rate is more pronounced in light eumelanic nestlings than in darker nest mates. To examine whether such an effect may be genetically determined, we swapped hatchlings between randomly chosen pairs of nests. We first showed that corticosterone affects growth and, thus, shapes the phenotype. Second, we found that under corticosterone administration, nestlings with large black spots grew better than nestlings with small black spots. As in the barn owl the expression of eumelanin-based coloration is heritable and not sensitive to environmental conditions, it is therefore a reliable, genetically based sign of the ability to cope with an increase in blood corticosterone level.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The role of estrogen and progesterone in the development of endometrial cancer is well documented. Few studies have examined the association of genetic variants in sex hormone-related genes with endometrial cancer risk. METHODS: We conducted a case-control study nested within three cohorts to examine the association of endometrial cancer risk with polymorphisms in hormone-related genes among 391 cases (92% postmenopausal at diagnosis) and 712 individually-matched controls. We also examined the association of these polymorphisms with circulating levels of sex hormones and SHBG in a cross-sectional analysis including 596 healthy postmenopausal women at blood donation (controls from this nested case-control study and from a nested case-control study of breast cancer in one of the three cohorts). RESULTS: Adjusting for endometrial cancer risk factors, the A allele of rs4775936 in CYP19 was significantly associated (OR(per allele)=1.22, 95% CI=1.01-1.47, p(trend)=0.04), while the T allele of rs10046 was marginally associated with increased risk of endometrial cancer (OR(per allele)=1.20, 95% CI=0.99-1.45, p(trend)=0.06). PGR rs1042838 was also marginally associated with risk (OR(per allele)=1.25, 95% CI=0.96-1.61, p(trend)=0.09). No significant association was found for the other polymorphisms, i.e. CYP1B1 rs1800440 and rs1056836, UGT1A1 rs8175347, SHBG rs6259 and ESR1 rs2234693. Rs8175347 was significantly associated with postmenopausal levels of estradiol, free estradiol and estrone and rs6259 with SHBG and estradiol. CONCLUSION: Our findings support an association between genetic variants in CYP19, and possibly PGR, and risk of endometrial cancer.