Aim: To investigate the stage-specific localization of transforming growth factor (TGF) β1 and β3 during spermatogenesis in adult human testis. Methods: The localization of TGFβ1 and β3 was investigated by immunoh...Aim: To investigate the stage-specific localization of transforming growth factor (TGF) β1 and β3 during spermatogenesis in adult human testis. Methods: The localization of TGFβ1 and β3 was investigated by immunohis tochemical staining method employing specific polyclonal antibodies. Results: Both TGFβ1 and β3 and their recep tors were preponderant in the Leydig celis. TGFβ1 could not be detected in the seminiferous tubules. TGFβ3 and TGFβ-Receptor (R) I were mainly seen in the elongated spermatids, while TGFβ-RⅡ in the pachytene spermatocytes and weak in the spermatogonia, spermatids and Sertoli celis. Only TGFβ-RⅡ was detected in the Sertoli celis. TGFβ3, TGFβ-RⅠ and TGFβ-RⅡ showed a staining pattern dependent upon the stages of the seminiferous epithelium cycle. Conclusion: TGFβ isoforms and their receptors are present in the somatic and germ celis of the adult human testis, suggesting their involvement in the regulation of spermatogenesis.展开更多
<abstract>Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Me...<abstract>Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Methods: The whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots. Results: Smadl, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smadl and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smadl was immunolocalized at the d14, d28 and adult testes, while Smad2, at the d7, d14, d28 and adult testis. There was positive irnmunoreaction in the Sertoli cells and Leydig cells as well. The immunolocalization of Smad4 was exclusively at the cytoplasm of Leydig cells and the nuclei were negative throughout the testicular development. No expression was detected in the germ cells. The results of image and statistical analysis showed that generally the expression of Smadl, Smad2 and Smad4 in the testis tended to increase gradually with the growth of the rat. Conclusion: The present data provide direct evidences for the molecular mechanism of TGF-βaction in rat testes during postnatal development and spermatogenesis.展开更多
The very virulent infectious bursal disease virus (vvIBDV) strain Gx was isolated from a poutl-try farm in Guangxi Province, China, during 1996. The mortality in the infected flock was 80% and occurred 5 days after im...The very virulent infectious bursal disease virus (vvIBDV) strain Gx was isolated from a poutl-try farm in Guangxi Province, China, during 1996. The mortality in the infected flock was 80% and occurred 5 days after immunization with serotype I IBD vaccine. The results of antigen-capture ELISA (AC-ELISA), pathogenicity testing, cloning and sequence analysis of the VP2 gene showed that the deduced amino acid sequence of strain Gx VP2 was the same as vvIBDV UK661, which is considered as a reference strain for European vvIBDVs. The antigenicity of the Gx strain was the same as an European vvIBDV strain 849. The EID50 of Gx virus was 10-8.25/0. 2 ml, and the mortality was 64% when 4 week-old SPF chickens were challenged at dosage of 2×10~3EID50. We have demonstrated that the IBDV strain Gx isolated in China is vvIBDV according to European standards.展开更多
The effects of oral insulin on intestinal tissue growth and brush border enzyme activitiesin newborn pigs were examined in this study. Newborn unsuckled pigs were bottle-fed for3 days with artificial milk(M), milk sup...The effects of oral insulin on intestinal tissue growth and brush border enzyme activitiesin newborn pigs were examined in this study. Newborn unsuckled pigs were bottle-fed for3 days with artificial milk(M), milk supplemented with 60mIUmL-1 of insulin(IM) orhydrolyzed milk(HM). Compared with newborn unsuckled pigs, piglets bottle-fed for 3 daysall gained in intestinal weight and length significantly despite a mild loss in bodyweight during the experimental period. The activities of lactase and alkaline phosphatase(AKP) in the small intestinal mucosa declined markedly in pigs fed with M, but theactivity of maltase increased significantly during the experimental period. Dietaryprotein pre-hydrolysis had no significant effect on intestinal tissue mass or length,but it moderated the decline of intestinal lactase and AKP activities. Dietarysupplementation of insulin significantly increased mucosal protein content and brushborder activities of lactase, maltase, AKP and aminopeptidase(AP)in the small intestine.The effect of insulin treatment was particularly obvious at the distal region of the smallintestine. These results demonstrate that oral insulin can stimulate intestinal digestiveenzyme activities in newborn pigs. The finding supports the hypothesis that milk-borneinsulin plays a role in regulating postnatal gut development in the suckling young.展开更多
Toxicological Impact of Benzenehexachloride on the Behaviour and Neuropathology of Heteropneustes fossilis.Organochlorine pesticides are widely used in the vast agricultural fields of Assam, India. Runoffs from treate...Toxicological Impact of Benzenehexachloride on the Behaviour and Neuropathology of Heteropneustes fossilis.Organochlorine pesticides are widely used in the vast agricultural fields of Assam, India. Runoffs from treated fields contaminates nearby bodies of water with organochlorine componds, which are neurotoxic to the ichthyofouna. The present work was designed to study the effect of bezenehexachloride on the behaviour and histopathology of Heteropneustes fossilis, as an experimental model.The experimental fish were exposed to different concentraions of the pesticide for 72 hoare. After exposure, the fish exhibited various behavioural changes. Histopathological exndnation of brain tis-sue revealed cytopathic and gross histopaholopcal alteratios, including necrosis and infrationalchanges. These results are consistent with the finding that organochlorides cause neurotoxic effects.展开更多
Juveniles of Oreochromis mossambicus with initial wet weights of 0.0382±0.0859 g and initial total lengths of 0.735 ±1.425 cm were tested for their salinity tolerance. The juveniles were subjected to five sa...Juveniles of Oreochromis mossambicus with initial wet weights of 0.0382±0.0859 g and initial total lengths of 0.735 ±1.425 cm were tested for their salinity tolerance. The juveniles were subjected to five salinity levels for a period of seventy five days. These salinity levels correspond to the salinities found along the creek and in estuarine regions. Each set of experiments was conducted at a fifteen day intervals. The weight, length and survival rate were calculated. No mortality was observed at salinity levels 0, 5, 10 and 15, while the juveniles faced slight mortality at 20 in the same environmental conditions, including the diet. There was no significant difference in specific growth rate at all salinity levels. The juveniles of O. mossambicus could survive up to 20 salinity. These results suggest that this species can grow and be exploited commercially in brackish waters, rivers and estuarine regions.展开更多
In seasonally breeding subtropical mammal, the Indian pelm squirrel (Funambulus pennanti), reproductive recrudescence is initiated before the winter solstice followed by sexually active condition which extends until t...In seasonally breeding subtropical mammal, the Indian pelm squirrel (Funambulus pennanti), reproductive recrudescence is initiated before the winter solstice followed by sexually active condition which extends until the end of summer season. Onset of seasonal regression coincides with the annual decrease in daily photoperiod and the increased level of relative humidity resulting from the arrival of monsoon at this latitude. To test the photoperiodic responses, the groupe of squirrels were exposed to natural day length (NDL), long day length (LD15:9), and Short day length (LD 6: 18) over a period of one year beginning from March. Squirrels of all these groupe were exposed to similar ambient temperature and humidity conditions.Initially, the rate of testicular development was similar in control and long day squirrels attaining peak values in May (0.67 cm3) and June (0.7 cm3) respectively. Thereafter, while the gonads of controls regressed, the latter maintained a plateau. On the other hand, the gonads of short day squirrels regressed sharply until June (0.21 cm3)followed by spontaneous recrudescence and finally a plateau (0.55 cm3). These results indicate that initially squirrels are photosensitive (as long days are gonadostimulatory and short days are inhibitory) in the first half of summer season but eventually become refractory to the inhibitory effect of short days. Obvinusly, an acyclic condition is developed under constant long as well short day conditions maintaining the neurocndocrine-gonadal-axis in a continuously active state. We suggest that in nature although gonadal growth of this species does not synchronize with the increase in daily photoperiod, it is partially regulated by an interplay of annual photocycle and humidity conditions. Present study also indicates that this species has developed a strong photoperiodic mechanism which may surposs the reproductive effect of other environmental factors when maintained in constant conditions of day length.展开更多
The present study was designed to ascertain the effects of temporal relationship of circadian neural oscillations on puberty attainment and reproductive growth of Japanese Quail, Coturnix coturnix japonica. Serotonin ...The present study was designed to ascertain the effects of temporal relationship of circadian neural oscillations on puberty attainment and reproductive growth of Japanese Quail, Coturnix coturnix japonica. Serotonin and dopamine precursors (5-hydroxytryptophan, 5-HTP and L-dihydroxyphenylalanine, L-DOPA; 5 mg/ 100 g body weight) were injected daily, 8 and 12 h apart in two groups of one-day old chicks, while controls received two daily injections of normal saline. Weekly/ biweekly observations (body weight, cloacal gland size, testicular volume and activity, ovarian follicular diameter and rate of egg production) were made until 9 weeks of age, wben the experiment was terminated. Results indicate that 8 h relationship completely suppressed gonadal growth even under long photoperiod (LD 16:8), while a 12 h relationship induced precocious sexual maturity and increased the rate of reproduction (spermatogenesis and egg production). It is concluded that circadian phase relationship of serotonergic and dopaminergic activity may not only determine the onset of reproduction in this poultry species, but may also alter the rate of reproduction possibly by affecting photoperiodic mechanism of reproductive regulation展开更多
文摘Aim: To investigate the stage-specific localization of transforming growth factor (TGF) β1 and β3 during spermatogenesis in adult human testis. Methods: The localization of TGFβ1 and β3 was investigated by immunohis tochemical staining method employing specific polyclonal antibodies. Results: Both TGFβ1 and β3 and their recep tors were preponderant in the Leydig celis. TGFβ1 could not be detected in the seminiferous tubules. TGFβ3 and TGFβ-Receptor (R) I were mainly seen in the elongated spermatids, while TGFβ-RⅡ in the pachytene spermatocytes and weak in the spermatogonia, spermatids and Sertoli celis. Only TGFβ-RⅡ was detected in the Sertoli celis. TGFβ3, TGFβ-RⅠ and TGFβ-RⅡ showed a staining pattern dependent upon the stages of the seminiferous epithelium cycle. Conclusion: TGFβ isoforms and their receptors are present in the somatic and germ celis of the adult human testis, suggesting their involvement in the regulation of spermatogenesis.
文摘<abstract>Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Methods: The whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots. Results: Smadl, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smadl and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smadl was immunolocalized at the d14, d28 and adult testes, while Smad2, at the d7, d14, d28 and adult testis. There was positive irnmunoreaction in the Sertoli cells and Leydig cells as well. The immunolocalization of Smad4 was exclusively at the cytoplasm of Leydig cells and the nuclei were negative throughout the testicular development. No expression was detected in the germ cells. The results of image and statistical analysis showed that generally the expression of Smadl, Smad2 and Smad4 in the testis tended to increase gradually with the growth of the rat. Conclusion: The present data provide direct evidences for the molecular mechanism of TGF-βaction in rat testes during postnatal development and spermatogenesis.
文摘The very virulent infectious bursal disease virus (vvIBDV) strain Gx was isolated from a poutl-try farm in Guangxi Province, China, during 1996. The mortality in the infected flock was 80% and occurred 5 days after immunization with serotype I IBD vaccine. The results of antigen-capture ELISA (AC-ELISA), pathogenicity testing, cloning and sequence analysis of the VP2 gene showed that the deduced amino acid sequence of strain Gx VP2 was the same as vvIBDV UK661, which is considered as a reference strain for European vvIBDVs. The antigenicity of the Gx strain was the same as an European vvIBDV strain 849. The EID50 of Gx virus was 10-8.25/0. 2 ml, and the mortality was 64% when 4 week-old SPF chickens were challenged at dosage of 2×10~3EID50. We have demonstrated that the IBDV strain Gx isolated in China is vvIBDV according to European standards.
基金supported by the Conference and Research Grants Committee of the University of Hong Kong the National Natural Science Foundation of China(30170688).
文摘The effects of oral insulin on intestinal tissue growth and brush border enzyme activitiesin newborn pigs were examined in this study. Newborn unsuckled pigs were bottle-fed for3 days with artificial milk(M), milk supplemented with 60mIUmL-1 of insulin(IM) orhydrolyzed milk(HM). Compared with newborn unsuckled pigs, piglets bottle-fed for 3 daysall gained in intestinal weight and length significantly despite a mild loss in bodyweight during the experimental period. The activities of lactase and alkaline phosphatase(AKP) in the small intestinal mucosa declined markedly in pigs fed with M, but theactivity of maltase increased significantly during the experimental period. Dietaryprotein pre-hydrolysis had no significant effect on intestinal tissue mass or length,but it moderated the decline of intestinal lactase and AKP activities. Dietarysupplementation of insulin significantly increased mucosal protein content and brushborder activities of lactase, maltase, AKP and aminopeptidase(AP)in the small intestine.The effect of insulin treatment was particularly obvious at the distal region of the smallintestine. These results demonstrate that oral insulin can stimulate intestinal digestiveenzyme activities in newborn pigs. The finding supports the hypothesis that milk-borneinsulin plays a role in regulating postnatal gut development in the suckling young.
文摘Toxicological Impact of Benzenehexachloride on the Behaviour and Neuropathology of Heteropneustes fossilis.Organochlorine pesticides are widely used in the vast agricultural fields of Assam, India. Runoffs from treated fields contaminates nearby bodies of water with organochlorine componds, which are neurotoxic to the ichthyofouna. The present work was designed to study the effect of bezenehexachloride on the behaviour and histopathology of Heteropneustes fossilis, as an experimental model.The experimental fish were exposed to different concentraions of the pesticide for 72 hoare. After exposure, the fish exhibited various behavioural changes. Histopathological exndnation of brain tis-sue revealed cytopathic and gross histopaholopcal alteratios, including necrosis and infrationalchanges. These results are consistent with the finding that organochlorides cause neurotoxic effects.
文摘Juveniles of Oreochromis mossambicus with initial wet weights of 0.0382±0.0859 g and initial total lengths of 0.735 ±1.425 cm were tested for their salinity tolerance. The juveniles were subjected to five salinity levels for a period of seventy five days. These salinity levels correspond to the salinities found along the creek and in estuarine regions. Each set of experiments was conducted at a fifteen day intervals. The weight, length and survival rate were calculated. No mortality was observed at salinity levels 0, 5, 10 and 15, while the juveniles faced slight mortality at 20 in the same environmental conditions, including the diet. There was no significant difference in specific growth rate at all salinity levels. The juveniles of O. mossambicus could survive up to 20 salinity. These results suggest that this species can grow and be exploited commercially in brackish waters, rivers and estuarine regions.
文摘In seasonally breeding subtropical mammal, the Indian pelm squirrel (Funambulus pennanti), reproductive recrudescence is initiated before the winter solstice followed by sexually active condition which extends until the end of summer season. Onset of seasonal regression coincides with the annual decrease in daily photoperiod and the increased level of relative humidity resulting from the arrival of monsoon at this latitude. To test the photoperiodic responses, the groupe of squirrels were exposed to natural day length (NDL), long day length (LD15:9), and Short day length (LD 6: 18) over a period of one year beginning from March. Squirrels of all these groupe were exposed to similar ambient temperature and humidity conditions.Initially, the rate of testicular development was similar in control and long day squirrels attaining peak values in May (0.67 cm3) and June (0.7 cm3) respectively. Thereafter, while the gonads of controls regressed, the latter maintained a plateau. On the other hand, the gonads of short day squirrels regressed sharply until June (0.21 cm3)followed by spontaneous recrudescence and finally a plateau (0.55 cm3). These results indicate that initially squirrels are photosensitive (as long days are gonadostimulatory and short days are inhibitory) in the first half of summer season but eventually become refractory to the inhibitory effect of short days. Obvinusly, an acyclic condition is developed under constant long as well short day conditions maintaining the neurocndocrine-gonadal-axis in a continuously active state. We suggest that in nature although gonadal growth of this species does not synchronize with the increase in daily photoperiod, it is partially regulated by an interplay of annual photocycle and humidity conditions. Present study also indicates that this species has developed a strong photoperiodic mechanism which may surposs the reproductive effect of other environmental factors when maintained in constant conditions of day length.
文摘The present study was designed to ascertain the effects of temporal relationship of circadian neural oscillations on puberty attainment and reproductive growth of Japanese Quail, Coturnix coturnix japonica. Serotonin and dopamine precursors (5-hydroxytryptophan, 5-HTP and L-dihydroxyphenylalanine, L-DOPA; 5 mg/ 100 g body weight) were injected daily, 8 and 12 h apart in two groups of one-day old chicks, while controls received two daily injections of normal saline. Weekly/ biweekly observations (body weight, cloacal gland size, testicular volume and activity, ovarian follicular diameter and rate of egg production) were made until 9 weeks of age, wben the experiment was terminated. Results indicate that 8 h relationship completely suppressed gonadal growth even under long photoperiod (LD 16:8), while a 12 h relationship induced precocious sexual maturity and increased the rate of reproduction (spermatogenesis and egg production). It is concluded that circadian phase relationship of serotonergic and dopaminergic activity may not only determine the onset of reproduction in this poultry species, but may also alter the rate of reproduction possibly by affecting photoperiodic mechanism of reproductive regulation
