38 research outputs found
Turkey Sperm Reside in the Tubular Glands in the Urodeum Following Artificial Insemination
A turkey hen in egg production requires 48 h after the last insemination to maximize the number of sperm in the uterovaginal junction sperm-storage tubules. Where the sperm that continue to fill the oviductal spermstorage sites during this 48-h period reside remains unknown. Histological sections of the juncture of the vagina with the urodeum, the central compartment of the cloaca, revealed deep tubular glands containing periodic acid- Schiff-positive secretory material. When examined 36 h after the last artificial insemination, sperm were observed in the lumen of the tubular glands associated with the urodeum. We suggest that sperm reside in the tubular glands within the urodeum and are released in association with the secretory activity of the tubular glands. These sperm then may ascend the vagina to continue to populate the sperm-storage tubules. Alternatively, the sperm in the tubular glands of the urodeum may be evidence of spermatorrhea and have no functional role in the fertilization process
Effects of Thermal Mass, Window Size, and Night-Time Ventilation on Peak Indoor Air Temperature in the Warm-Humid Climate of Ghana
Most office buildings in the warm-humid sub-Saharan countries experience high cooling load because of the predominant use of sandcrete blocks which are of low thermal mass in construction and extensive use of glazing. Relatively, low night-time temperatures are not harnessed in cooling buildings because office openings remain closed after work hours. An optimization was performed through a sensitivity analysis-based simulation, using the Energy Plus (E+) simulation software to assess the effects of thermal mass, window size, and night ventilation on peak indoor air temperature (PIAT). An experimental system was designed based on the features of the most promising simulation model, constructed and monitored, and the experimental data used to validate the simulation model. The results show that an optimization of thermal mass and window size coupled with activation of night-time ventilation provides a synergistic effect to obtain reduced peak indoor air temperature. An expression that predicts, indoor maximum temperature has been derived for models of various thermal masses
Local Increase of Arginase Activity in Lesions of Patients with Cutaneous Leishmaniasis in Ethiopia
The leishmaniases are a complex of diseases caused by Leishmania parasites. Currently, the diseases affect an estimated 12 million people in 88 countries, and approximately 350 million more people are at risk. The leishmaniases belong to the most neglected tropical diseases, affecting the poorest populations, for whom access to diagnosis and effective treatment are often not available. Leishmania parasites infect cells of the immune system called macrophages, which have the capacity to eliminate the intracellular parasites when they receive the appropriate signals from other cells of the immune system. In nonhealing persistent leishmaniasis, lymphocytes are unable to transmit the signals to macrophages required to kill the intracellular parasites. The local upregulation of the enzyme arginase has been shown to impair lymphocyte effector functions at the site of pathology. In this study, we tested the activity of this enzyme in skin lesions of patients presenting with localized cutaneous leishmaniasis. Our results show that arginase is highly upregulated in these lesions. This increase in arginase activity coincides with lower expression of a signalling molecule in lymphocytes, which is essential for efficient activation of these cells. These results suggest that increased arginase expression in the localized cutaneous lesions might contribute to persistent disease in patients presenting with cutaneous leishmaniasis
Morphological and histochemical characterization of the seminiferous epithelial and Leydig cells of the turkey
Serotonin Localization in the Turkey Vaginal but not Sperm Storage Tubule Epithelia
Elucidating the cellular and molecular mechanisms regulating sperm selection and transport in the vagina of the hen had been the focus of a limited amount of research over the past decade. New observations indicate the presence of nonneuron endocrine cells in the epithelia lining the lumina of the turkey hen vagina and uterovaginal junction. Although no cells in the vagina or uterovaginal junction surface epithelia exhibited argentaffin staining, typical of cells containing neurosecretory granules, cells restricted to the vaginal and uterovaginal junction but not the sperm storage tubule epithelia were immunoreactive positive to serotonin. We speculate that if released into the vaginal lumen and submucosa, serotonin could augment cilia and sperm tail beat frequencies and facilitate smooth muscle contraction, respectively. If this is the response to sperm at insemination, it would represent the first evidence of a local control mechanism responding to sperm in the turkey vagina
Alkaline phosphatase reactivity in the vagina and uterovaginal junctionsperm-storage tubules of turkeys in egg production: implications forsperm storage
1. Currently there remains contradictory intortliation on the localisation and possible roleof alkaline phosphatase (AP) in the chicken and Japanese quail oviducts.
2.Using turkeys with a hard-shelled egg in their uteri, vaginal and uterovaginal junction mucosae werestretched and fixed as whole mounts prior to the Imistochemical localisation of All activity.
3.Scattered All reactive cells were observed in the vaginal and uteiovaginal junction surface epitheliaand intense All reactivity of the sperm-storage tubule (SST) epithelium, localised to its apical border.
4.We suggest that such All in hens in egg production may reflect cell dif.ftreiitiation andproliferation in the vagina and SST and possibly a mechanism lor the transfer of lipid from the SSTepithelia to resident sperm
Impact of Egg Storage on Embryo Development
1. New information is introduced and other information reviewed regarding the impact of egg storage on the integrity of the avian embryo.
2. Morphologically, the blastoderm from an egg which has been stored more than 10 days is often asymmetrical and may have an attenuated appearance.
3. Fresh egg breakouts coupled with the perivitelline layer sperm-hole determination procedure provide detailed information on the male\u27s contribution to overall fertility.
4. The biological basis for embryonic mortality in eggs stored for longer than 10 days remains the subject of speculation