Vascular Endothelial Growth Factor and Kinase Domain Region Receptor Are Involved in Both Seminiferous Cord Formation and Vascular Development During Testis Morphogenesis in the Rat

Morphological male sex determination is dependent on migration of endothelial and preperitubular cells from the adjacent mesonephros into the developing testis. Our hypothesis is that VEGFA and its receptor KDR are necessary for both testicular cord formation and neovascularization. The Vegfa gene has 8 exons with many splice variants. Vegfa120, Vegfa164, and Vegfa188 mRNA isoforms were detected on Embryonic Day (E) 13.5 (plug date = E0) in the rat. Vegfa120, Vegfa144, Vegfa164, Vegfa188, and Vegfa205 mRNA were detected at E18 and Postnatal Day 3 (P3). Kdr mRNA was present on E13.5, whereas Fms-like tyrosine kinase 1 receptor (Flt1) mRNA was not detected until E18. VEGFA protein was localized to Sertoli cells at cord formation and KDR to germ and interstitial cells. The VEGFA signaling inhibitors SU1498 (40 μM) and VEGFR-TKI (8 μM) inhibited cord formation in E13 testis cultures with 90% reduced vascular density (P \u3c 0.01) in VEGFR-TKI-treated organs. Furthermore, Je-11 (10 μM), an antagonist to VEGFA, also perturbed cord formation and inhibited vascular density by more than 50% (P \u3c 0.01). To determine signal transduction pathways involved in VEGFA’s regulation of testis morphogenesis, E13 testis were treated with LY 294002 (15 μM), a phosphoinositide 3-kinase (PI3K) pathway inhibitor, resulting in inhibition of both vascular density (46%) and cord formation. Thus, we support our hypothesis and conclude that VEGFA, secreted by the Sertoli cell, is involved in both neovascularization and cord formation and potentially acts through the PI3K pathway during testis morphogenesis to elicit its effects

Vascular Endothelial Growth Factor and Kinase Domain Region Receptor Are Involved in Both Seminiferous Cord Formation and Vascular Development During Testis Morphogenesis in the Rat

Morphological male sex determination is dependent on migration of endothelial and preperitubular cells from the adjacent mesonephros into the developing testis. Our hypothesis is that VEGFA and its receptor KDR are necessary for both testicular cord formation and neovascularization. The Vegfa gene has 8 exons with many splice variants. Vegfa120, Vegfa164, and Vegfa188 mRNA isoforms were detected on Embryonic Day (E) 13.5 (plug date = E0) in the rat. Vegfa120, Vegfa144, Vegfa164, Vegfa188, and Vegfa205 mRNA were detected at E18 and Postnatal Day 3 (P3). Kdr mRNA was present on E13.5, whereas Fms-like tyrosine kinase 1 receptor (Flt1) mRNA was not detected until E18. VEGFA protein was localized to Sertoli cells at cord formation and KDR to germ and interstitial cells. The VEGFA signaling inhibitors SU1498 (40 μM) and VEGFR-TKI (8 μM) inhibited cord formation in E13 testis cultures with 90% reduced vascular density (P \u3c 0.01) in VEGFR-TKI-treated organs. Furthermore, Je-11 (10 μM), an antagonist to VEGFA, also perturbed cord formation and inhibited vascular density by more than 50% (P \u3c 0.01). To determine signal transduction pathways involved in VEGFA’s regulation of testis morphogenesis, E13 testis were treated with LY 294002 (15 μM), a phosphoinositide 3-kinase (PI3K) pathway inhibitor, resulting in inhibition of both vascular density (46%) and cord formation. Thus, we support our hypothesis and conclude that VEGFA, secreted by the Sertoli cell, is involved in both neovascularization and cord formation and potentially acts through the PI3K pathway during testis morphogenesis to elicit its effects

Cotton Rats and House Sparrows as Hosts for North and South American Strains of Eastern Equine Encephalitis Virus

TOC summary: Wild rodents and wild birds can serve as amplification hosts

Building referral mechanisms for neonatal care in humanitarian emergency settings: A systematic review

AIM: During humanitarian emergencies, women and children are particularly vulnerable to health complications and neonatal mortality rates have been shown to rise. Additionally, health cluster partners face challenges in coordinating referrals, both between communities and camps to health facilities and across different levels of health facilities. The purpose of this review was to identify the primary referral needs of neonates during humanitarian emergencies, current gaps and barriers, and effective mechanisms for overcoming these barriers. METHODS: A systematic review was performed using four electronic databases (CINAHL, EMBASE, Medline, and Scopus) between June and August 2019 (PROSPERO registration number CRD42019127705). Title, abstract, and full text screening were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The target population was neonates born during humanitarian emergencies. Studies from high-income countries and prior to 1991 were excluded. The STROBE checklist was used to assess for risk of bias. RESULTS: A total of 11 articles were included in the analysis; these were mainly cross-sectional, field-based studies. The primary needs identified were referrals from homes to health facilities before and during labour, and inter-facility referrals after labour to more specialised services. Some of the main barriers included a lack of roads and infrastructure for transport, staff shortages-especially among more specialised services, and a lack of knowledge among patients for self-referral. Mechanisms for addressing these needs and gaps included providing training for community healthcare workers (CHWs) or traditional birth attendants to identify and address antenatal and post-natal complications; education programmes for pregnant women during the antenatal period; and establishing ambulance services in partnership with local Non-Governmental Organizations. CONCLUSION: This review benefited from a strong consensus among selected studies but was limited in the quality of data and types of data that were reported. Based on the above findings, the following recommendations were compiled: Focus on local capacity-building programmes to address programmes acutely. Recruit CHWs to raise awareness of neonatal complications among pregnant women. Upskill CHWs to provide timely, appropriate and quality care during humanitarian emergencies

Vascular Endothelial Growth Factor mRNA Isoforms 120 and 164 are Differentially Regulated Prior to Ovulation

Vascular Endothelial Growth Factor (VEGF) is produced by cells surrounding the egg in the follicle prior to ovulation. If VEGF is inhibited, ovulation does not occur. The VEGF gene can be spliced to produce different protein isoforms which have specific functions. Our objective was to determine if VEGF 120 and 164 mRNA isoforms are differentially regulated in the preovulatory follicle. From our studies, VEGF isoforms are differentially regulated during both CL regression and after a simulated LH surge. Differences observed in VEGF isoform regulation may allow for manipulation of ovulation in the beef cow

144 EFFECT OF ANTRAL FOLLICLE COUNT IN BEEF HEIFERS ON \u3ci\u3eIN VITRO\u3c/i\u3e FERTILIZATION/PRODUCTION

Our objective has been to compare the IVF and in vitro production (IVP) of embryos from low and high antral follicle count (AFC) heifers. This is the fourth year of the study with years 1 to 3 reported individually. For this report, we add data for the fourth year and present a combined analysis (years 1 to 4) for the first time. Each year, AFC was determined on ~120 Angus heifers using transrectal ultrasonography. Ten heifers with the lowest AFC and 10 heifers with the highest AFC and all with evidence of oestrous cyclicity were synchronized with two 5-mL injections of PGF2α 11 days apart. Half were harvested on Day 5 to 6 and half on Day 15 to 16 of the oestrous cycle. The IVF procedure was slightly modified each year. For year 4, the IVF procedure included protocols for semi-defined media and was as described (IVP Protocol, P. J. Hansen’s Laboratory, University of Florida). Cumulus-oocyte complexes (COC) from follicles less than 8 mm in diameter were cultured in maturation medium (5% CO2; 38.5°C) for 24 h

Vascular Endothelial Growth Factor mRNA Isoforms 120 and 164 are Differentially Regulated Prior to Ovulation

Vascular Endothelial Growth Factor (VEGF) is produced by cells surrounding the egg in the follicle prior to ovulation. If VEGF is inhibited, ovulation does not occur. The VEGF gene can be spliced to produce different protein isoforms which have specific functions. Our objective was to determine if VEGF 120 and 164 mRNA isoforms are differentially regulated in the preovulatory follicle. From our studies, VEGF isoforms are differentially regulated during both CL regression and after a simulated LH surge. Differences observed in VEGF isoform regulation may allow for manipulation of ovulation in the beef cow

Natural Enzootic Vectors of Venezuelan equine encephalitis virus in the Magdalena Valley, Colombia

To characterize the transmission cycle of enzootic Venezuelan equine encephalitis virus (VEEV) strains believed to represent an epizootic progenitor, we identified natural vectors in a sylvatic focus in the middle Magdalena Valley of Colombia. Hamster-baited traps were placed into an active forest focus, and mosquitoes collected from each trap in which a hamster became infected were sorted by species and assayed for virus. In 18 cases, a single, initial, high-titered mosquito pool representing the vector species was identified. These vectors included Culex (Melanoconion) vomerifer (11 transmission events), Cx. (Mel.) pedroi (5 transmissions) and Cx. (Mel.) adamesi (2 transmissions). These results extend the number of proven enzootic VEEV vectors to 7, all of which are members of the Spissipes section of the subgenus Melanoconion. Our findings contrast with previous studies, which have indicated that a single species usually serves as the principal enzootic VEEV vector at a given location

Conservation Status of the Southern Appalachian Herpetofauna

Seventy one species of amphibians (55 salamanders, 16 anurans) and 46 species of reptiles (15 turtles, 8 lizards, 23 snakes) inhabit a five state area (Kentucky, North Carolina, Tennessee, Virginia, West Virginia) in the southern Appalachian region bordered by the Potomac River, the Blue Ridge Mountains, and the western margin of the Appalachian Plateau. Of these, 47.9 % of the amphibian fauna and 52.2 % of the reptilian fauna are listed as being of conservation concern by federal, state, and Natural Heritage programs in all or a portion of their ranges of this region. The Shenandoah salamander (Plethodon Shenandoah) is listed as Endangered and the Cheat Mountain salamander (Plethodon Shenandoah) is listed as Endangered and the Cheat Mountain salamander (Plethodon nettingi) is listed as Threatened under the U.S. Endangered Species Act. Nine others are classified as federal species at risk. State endangered species number 1-3 (per state), threatened 1-4, and special concern or declining 6-19. Three to 6 species per state are additionally listed as natural heritage S1 and 2-13 as S2. We review the existing and potential threats to species and populations (e.g., timbering, urbanization, collection for the wildlife trade, acid precipitation, introduced species) and provide an assessment of the conservation status of the southern Appalachian herpetofauna based on land ownership

Letrozole: A Steroid-Free Estrous Synchronization Method

Most bovine estrous synchronization protocols utilize progesterone plus estrogen to control ovulation timing. A drug that inhibits estrogen production (Letrozole) may be an alternative, steroid-free synchronization method (not yet commercially available). However, low estrogen can negatively affect the health of follicles/oocytes and impact fertility. To determine its effects, Letrozole was administered intramuscularly while tracking follicle growth and circulating hormones. Letrozole response was variable. Two of three cows experienced delayed luteolysis/ovulation and extended progesterone production. This preliminary data indicates that Letrozole treatment allows normal follicle progression but drug response may vary and little is known about effects on oocyte quality