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1.
Abstract

Serum concentrations of progesterone (P) and estradiol (E2) were measured over a 7-month period in two captive juvenile female manatees Trichechus manatus. The animals, aged 5.17 and 6.58 years, had mean (±95% confidence interval) serum P concentrations of 0.45 ± 0.27 ng/mL and 0.67 ± 0.24 ng/mL, and mean serum E2 concentrations of 91.1 ± 71.9 pg/ mL and 121.6 ± 50.6 pg/mL, respectively. A mature male was sampled twice: serum P was 0.92 and 0.79 ng/ mL, and serum E2 was 117.6 and 207.8 pg/mL. A gravid female was sampled once during her first trimester: serum P was 3.42 ng/mL, and E2 was 27.7 pg/mL.  相似文献   

2.
A Japanese Black cow was evaluated for prolonged post‐partum anestrus and enlargement of the right ovary. Transrectal ultrasonography revealed that the right ovary was markedly enlarged and had a solid appearance, while the left ovary was small and inactive. The presumptive diagnosis was directed towards granulosa‐theca cell tumour (GTCT) which was supported by markedly elevated plasma anti‐Müllerian hormone (AMH; 332.0 ng/ml), oestradiol (E2; 103.3 pg/ml) and immunoreactive inhibin (ir‐INH; 2.1 ng/ml) in comparison with the diagnostic cut‐off points for bovine GTCTs. Since the cow had been infertile and had swelling of the udder, slaughter was chosen. Histopathological examination revealed that the tumour was an ovarian sex cord–stromal tumour (SCST) with a Sertoli cell pattern. These findings suggest that plasma AMH, ir‐INH and E2 could be possible biomarkers for bovine ovarian SCST with a Sertoli cell pattern, whereas this case could not be distinguished from GTCTs based on endocrinological profile.  相似文献   

3.
A novel, simple method of infectious center assay was developed to detect and quantitate the intracellular existence of equine herpesvirus 1 and equine herpesvirus 2 in peripheral blood mononuclear cells infected in vivo and in vitro with the viruses by cocultivation of these cells with a permissive equine cell culture. The infectious center titers were correlated with the infectious virus titers. In vivo equine herpesvirus 1-infected mononuclear cells obtained from ponies experimentally infected with the virus and equine herpesvirus 2-infected mononuclear cells obtained from selected naturally infected ponies with the virus gave by infectious center assay a mean value of 67 infectious center/2 x 106 cells as a peak titer on day 4 postinfection and 26 infectious center/2 x 106 cells for equine herpesvirus 1 and equine herpesvirus 2 respectively. The mononuclear cells, in both cases, did not contain detectable infectious virus, but the infectious virus was detected from the respective cells when they were cultured in the presence of mitogen. The equine herpesvirus 1 infected mononuclear cells in culture gave a mean count of 8.05 x 102 infectious center/2 x 106 cells/mL and contained 1.08 x 104 plague assay/mL of infectious virus. Similarly the equine herpesvirus 2 infected mononuclear cells in culture gave a mean count of 7.1 x 101 infectious center/2 x 106 cells/mL and contained <101 tissue culture infective dose50/mL of infectious virus. Mononuclear cells infected in vitro with equine herpesvirus 1 gave a mean count of 9.3 x 104 infectious center/2 x 106 cells/mL and contained 5.75 x 103 plaque assay/mL of infectius virus. Culturing these cells in the presence of mitogen gave a mean count of 5.5 x 103 infectious center/2 x 106 cells/mL and contained 9 x 103 plague assay/mL of infectious virus. A correlation between infectious center assay and infectious virus assay is discussed.  相似文献   

4.
To identify factors involved in the establishment of pregnancy in the mare, endometrium was collected from day 13 (day 0 = day of ovulation) cyclic and day 13, 19, and 25 pregnant animals. From initial cDNA subtraction studies, interleukin-1 receptor antagonist (IL-1RN) mRNA was found as a candidate molecule expressed uniquely in the pregnant endometrium. Expression of IL-1RN mRNA was markedly increased in day 19 and 25 gravid endometrium. In situ hybridization analysis revealed that IL-1RN mRNA was localized to the glandular epithelium. Interleukin-1 receptor antagonist (IL-1RN) protein was found in the extracts of day 25 gravid endometrium and was immunochemically localized to the glandular epithelium/luminal cavity of the pregnant uterus. High concentrations of estradiol-17β (E2) were detected in day 25 conceptuses. Concentrations of E2 were higher in the gravid endometrial portion than in other endometrial regions. On the other hand, progesterone concentrations did not differ among endometrial samples analyzed. Furthermore, the expression of IL-1RN mRNA was up-regulated in endometrium culture samples treated with 10 ng/mL E2 and 10 ng/mL progesterone. In the analysis of related gene expression, increased amounts of IL-1α and IL-6 mRNA were also found in the day 25 gravid endometrium; however, these expressions in endometrial culture samples were not up-regulated by the steroid treatment. These results indicate that expression of IL-1RN in the endometrium is likely regulated by E2 and progesterone and suggest that IL-1RN regulates the degree of IL-1 signal transduction and thereby plays an important role in the establishment of equine pregnancy.  相似文献   

5.
Ovarian steroids assure an optimum environment for the final maturation of oocytes, gamete transport, fertilization, and early embryonic development. The aim of experiment 1 was to examine the influence of ovarian steroids on tumor necrosis factor-α (TNF-α)- or nitric oxide (NO)-regulated prostaglandin (PG), and nitrite/nitrate (NO2/NO3) secretion by cultured bovine oviductal epithelial cells (BOECs). BOECs were pretreated with 17β-estradiol (E2; 10−9 M) and/or progesterone (P4; 10−7 M) for 24 h. For the next 24 h, BOECs were treated with TNF-α (10 ng/mL) or spermine nitric oxide complex (NONOate; 10−5 M). Prostaglandin F2α and PGE2 secretion was measured in medium by ELISA. The pretreatment of cells with P4 (progesterone), E2 (17 β-estradiol), or E2/P4 augmented TNF-α-induced PGF2α and PGE2 secretion (P < 0.01). The pretreatment of cells with E2 or E2/P4 increased NONOate-induced PGF2α and PGE2 secretion (P < 0.01). TNF-α induced NO2/NO3 production by BOECs. The pretreatment of cells with E2 augmented only TNF-α-induced NO2/NO3 production (P < 0.05). The aim of experiment 2 was to examine the influence of TNF-α, NO, and ovarian steroids on the protein content of enzymes specifically involved in PG and NO production, PG synthases, and NO synthases (NOSs). BOECs were treated with TNF-α (10 ng/mL) or NONOate (10−5 M). TNF-α increased the protein content of PGG/H synthase, PGF synthase, and PGE synthase (P < 0.05) and endothelial and inducible NOSs (P < 0.05). Nitric oxide increased the protein content of PGF synthase, PGE synthase, endothelial NOS, and inducible NOS (P < 0.05). These results show possible linkage between TNF-α and NO, modulated by ovarian steroids, in the regulation of PG synthesis by BOECs that may be important for triggering the process of oviductal contractions.  相似文献   

6.
Objective The physiologic mechanisms involving growth factors, including PDGF‐BB, EGF, and TGF‐β1, as potent mediators of fibroblasts and epithelial cells in corneal wound healing remain unknown. The goal of this study was to determine culture methods for equine epithelial cells and keratocytes and to investigate how exogenous growth factors influence proliferation of both cell types. Procedures Cell cultures were established from healthy corneas harvested from horses immediately following euthanasia and maintained using standard tissue culture protocols. To determine the effects of PDGF‐BB, EGF, TGF‐β1, keratocytes (1 × 105/well) and epithelial cells (2 × 105/well) were each cultured in 12 well plates and exposed separately to the growth factors. The cells were exposed to concentrations of EGF between 0 and 50 ng/mL; PDGF‐BB between 0 and 75 ng/mL; and TGF‐β1 between 0 and 10 ng/mL. Cell proliferation was measured using 3H‐thymidine assay and differences in growth determined using anova and Tukey's HSD test (P < 0.05). Results Epithelial cell and keratocyte cultures were successfully established. EGF maximally stimulated keratocyte and epithelial cells at 25 ng/mL and 5 ng/mL, respectively. PDGF‐BB maximally stimulated keratocytes and epithelial cells at 50 ng/mL and 5 ng/mL, respectively. TGF‐β1 inhibited keratocytes at 5 ng/mL and 10 ng/mL, and epithelial cells at 1 ng/mL and 2 ng/mL. Conclusions Methods were established to maintain epithelial cells and keratocytes in vitro. PDGF‐BB and EGF stimulate, while TGF‐β1 inhibits the proliferation of epithelial cells and keratocytes. These growth factors may play a role in maintenance and repair of the equine cornea.  相似文献   

7.
为了研究不同条件对ICR小鼠ES细胞的影响,试验以12.5~13.5 d ICR小鼠胚胎成纤维细胞(MEF)为饲养层,以3.5 d ICR小鼠胚胎为试验材料,探讨了血清、生长因子及传代方法对ICR小鼠ES细胞分离培养的影响。结果表明:采用含15%FBS的ES细胞培养液的囊胚贴壁率及ICM增殖率(79.3%,69.0%)均比含15%KSR、5%FBS+10%KSR的细胞培养液高(42.9%,28.6%;75.0%,54.2%),ES细胞最高传至6代;培养液中添加10 ng/mL LIF+10 ng/mL SCF的效果比单独添加1种因子的效果好,最高传至6代,高于单独添加1种因子的传代数(4代,2代);用3种传代方法进行传代时,采用差异贴壁法传代效果最佳,最高传至8代,酶消化法传至4代,机械加酶消化法传至6代。  相似文献   

8.
鸡胚胎干细胞的分离和培养   总被引：2，自引：0，他引：2  
实验从鸡第X期胚胎中分离胚盘,以鸡成纤维细胞为饲养层,用添加了10%的胎牛血清、2%的鸡血清、2mmol/LL-谷氨酰胺、1mmol/L丙酮酸钠、5.5×10-5mol/Lβ-巯基乙醇、10μL/mL非必需氨基酸以及含1000IU/mL白血病抑制因子(LIF)、10ng/mL碱性成纤维生长因子(bFGF)和5ng/mL干细胞生长因子(SCF)的高糖DMEM对细胞进行培养和传代,可以获得传至5～6代的鸡胚胎干细胞(ES)。通过对传代培养后的鸡ES细胞进行AKP染色鉴定和SSEA-1的鉴定,证实细胞未发生分化,具有胚胎干细胞的特征。同时通过不同分离胚盘方法和不同消化时间的比较得出药勺法提取胚盘简单易行,原代消化5～8min的ES细胞适合于传代培养。  相似文献   

9.
研究采用 1 4～ 1 8d兔胎儿的生殖嵴及周围组织与其同源成纤维细胞共培养 ,低糖DMEM +1 0 %NBS +1 0 %FCS +1 0ng/mLLIF +1 0ng/mLSCF+0 1mol/Lβ 巯基乙醇 +1 0 0U/mL青霉素 +80U/mL链霉素作培养基 ,分离出兔原始生殖细胞 (PGC) ,克隆并多次传代。从原始生殖细胞 (PGC)中获得胚胎生殖细胞 (EG)细胞集落 ,1 4d胎儿原代观察到类EG细胞集落 ,传至 4代后丢失。 1 6d胎儿的类EG只传 2代 ,1 8d胎儿没有得到EG细胞集落。EG细胞具有干细胞的诸多特征 ,呈典型的团块状聚集生长 ,碱性磷酸酶 (AKP)染色呈阳性 ,在衰老饲养层的培养基中生长形成类胚体、上皮细胞、神经细胞和成纤维细胞等  相似文献   

10.
Canine cognitive dysfunction syndrome (CDS) is a neurodegenerative disorder of aged dogs characterized by a progressive decline in cognitive function. In humans and laboratory animals, a variety of neurotransmitter abnormalities have been described in patients affected by age-related dementia. Specifically, the regulatory role of the catecholaminergic, serotonergic, and cholinergic systems has been outlined. The aim of the present study was to measure blood monoamine levels, platelet α2-adrenergic receptors, and lymphocyte muscarinic receptors in healthy adult and aged dogs and in dogs affected by canine cognitive dysfunction. Based on clinical and behavioral examination, 40 dogs were divided into 3 groups: healthy adults (n = 14), aged dogs (n = 17), and aged dogs affected by canine cognitive dysfunction (n = 9). A significant reduction in plasma levels of norepinephrine and dopamine was observed both in aged dogs (0.16 ± 0.02 ng/mL, P < 0.01; 0.11 ± 02 ng/mL, P < 0.01, respectively) and in CDS dogs (0.14 ± 0.03 ng/mL, P < 0.05; 0.10 ± 00.005 ng/mL, P < 0.01, respectively) compared with adults (0.29 ± 0.04 ng/mL and 0.15 ± 0.02 ng/mL, respectively). No significant differences were observed among groups for α2-adrenergic receptor concentrations. Canine lymphocytes express 2 distinct classes of muscarinic receptors, characterized by high (HA) and low affinity (LA) for [3H]-N-methyl-scopolamine. A significant age-dependent decrease in HA muscarinic receptors was observed. However, no differences were found between aged dogs (87.65 ± 11.08 sites/cell × 102) and in CDS dogs (90.17 ± 6.75 sites/cell × 102 ) for HA muscarinic receptor concentrations. As far as LA muscarinic receptors are concerned, CDS dogs showed a significant increase (393.48 ± 63 sites/cell × 102; P < 0.05) with respect to healthy adult dogs (188.84 ± 16.50 sites/cell × 102). Our results suggest that the reduction in HA muscarinic receptor-binding sites could be representative of the physiological aging process, whereas the increase in lymphocyte LA muscarinic receptor levels could be related to the cognitive decline.  相似文献   

11.
Objective – To determine whether myoglobin (Mb) is a useful prognostic indicator for outcome and to investigate any relationship between Mb and mortality in dogs with gastric dilatation‐volvulus (GDV). Design – Prospective study. Setting – Veterinary teaching hospital. Animals – Seventy‐two dogs with GDV. Interventions – Blood sampling. Measurements and Main Results – Mb levels were measured at the time of diagnosis (Mbt0), 24 hours (Mbt1), and 48 hours (Mbt2) after signs of GDV were recognized. Fifty‐seven dogs survived (group I) and 15 dogs did not survive (group II). Mb t0 differed significantly between groups (P=0.04). Mbt0 in group I ranged from <30 to >700 ng/mL (n=57, median 74 ng/mL), and in group II from 34 to >700 ng/mL (n=15, median 238 ng/mL). Analysis of a receiver operating characteristic curve of Mbt0 suggested that the best single cutpoint would be 168 ng/mL (sensitivity 60.0%, specificity 84.2%). Fifty percent of dogs with Mbt0>168 ng/mL were euthanized, while 88.9% with Mbt0<168 ng/mL survived. Mbt1 and Mbt2 differed significantly between groups I and II. Mbt1 in group I ranged from 32 to >700 ng/mL (n=55, median 123 ng/mL), and Mbt1 in group II ranged from 131 to 643 ng/mL (n=7, median 343 ng/mL) (P=0.006). Mbt2 in group I ranged from 30 to 597 ng/mL (n=54, median 101 ng/mL), and in group II from 141 to >700 ng/mL (n=8, median 203 ng/mL) (P=0.02). Conclusions – In this study, Mbt0 is a moderately sensitive and specific prognostic indicator. Almost 90% of the dogs below the cutpoint survived to discharge, whereas 50% with Mbt0 above the cutpoint did not survive.  相似文献   

12.

Background

Estradiol (E2) is required for luteolysis in cows and its injection stimulates prostaglandin F2α (PGF2α) release. The main goal of our study was to investigate the ability of endometrial explants and cells treated with E2 and the calcium ionophore (CI) A23187 to synthesize PGF2α.

Results

Treatment with E2in vivo resulted in a 48.4% increase of PGF2α production by endometrial explants treated in vitro with A23187. Production of PGF2α was better stimulated with A23187 at concentrations of 10-6 and 10-5 mol/L compared with other concentrations used. The concentration of PGF2α for untreated bovine endometrial cell cultures was 33.1 pg/mL, while for cultures treated with E2, A23187, or a combination of E2 and A23187, the PGF2α concentration was 32.5, 92.4 and 145.6 pg/mL, respectively.

Conclusions

Treatment with A23187 tended to stimulate PGF2α production. In the presence of E2, A23187 significantly stimulated PGF2α synthesis. It appears that A23187 potentiates the effects of E2 with respect to synthesis of endometrial PGF2α in cattle.  相似文献   

13.
We investigated the effect of the leukaemia inhibitory factor (LIF) alone or in association with FSH on the in vitro culture (IVC) of caprine preantral follicles. Preantral follicles >200 μm in size were isolated and cultured for 18 days in basic medium either alone (control) or supplemented with LIF (10 or 50 ng/ml) in the absence or presence of FSH. Every 6 days, follicular survival, growth and antrum formation were evaluated. At the end of the culture period, the oocytes underwent in vitro maturation (IVM), and their viability and chromatin configuration were assessed. Follicles of the control group and those cultured in 10 ng/ml LIF maintained the structural integrity (particularly the preservation of the basement membrane) when compared to the oocytes cultured in 50 ng/ml LIF, regardless the presence of FSH. In the absence of FSH, the percentage of antrum formation after 18 days of culture in the 50 ng/ml LIF group was significantly lower than in either the control group or the 10 ng/ml LIF group. However, this effect was not observed in the presence of FSH. The rate of resumption of meiosis was significantly higher in the 50 ng/ml LIF group in the absence of FSH in comparison with the control and 10 ng/ml LIF groups. Metaphase II was observed only when follicles were cultured in a combination of FSH and 50 ng/ml LIF. In conclusion, LIF alone does not interfere with antral formation and oocyte growth, but at concentration of 50 ng/ml and combined with FSH, it promotes oocyte maturation.  相似文献   

14.
为了揭示雌激素(estrogen,E2)对奶牛输卵管上皮细胞中前列腺素E2合成酶(PGES)和前列腺素F2α合成酶(PGFS)mRNA表达的影响,探讨E2对奶牛输卵管生殖生理的调节作用,本试验采用了体外培养荷斯坦奶牛输卵管上皮细胞技术,分不同时间(0、2、4、8、16、24和48 h)和不同浓度(10-12、10-11、10-10、10-9 mol/L)添加雌激素E2(以不加雌激素作空白对照),采用荧光定量PCR 技术检测PGES和PGFS mRNA表达。不同浓度的E2或同一浓度不同刺激时间的E2均能增加PGES的表达,但4 h浓度为10-10 mol/L时与空白对照相比差异极显著(P<0.01),而PGFS在24 h添加浓度为10-12 mol/L E2时与空白对照相比差异极显著(P<0.01)。试验结果表明,E2对培养的奶牛输卵管上皮细胞PGES和PGFS mRNA的表达有促进作用,说明雌激素E2对前列腺素酶PGES和PGFS mRNA的表达具有调控作用。  相似文献   

15.
The aim of these in vivo and in vitro studies was to examine the role of ghrelin in the control of plasma hormone concentrations, the proliferation, apoptosis and secretory activity of ovarian granulosa cells and the response of these cells to hormonal treatments. Female rabbits were injected with ghrelin (10 μg/animal/day for one week before ovulation induced by 25 IU PMSG and 0.25 IU LHRH). On the day of ovulation, blood samples were collected and analyzed for concentrations of progesterone (P4), testosterone (T), estradiol (E2), estrone-sulphate (ES), insulin-like growth factor I (IGF-I) and leptin (L) by RIA. Some control and ghrelin-treated animals were killed in the periovulatory period, their ovaries were weighed and granulosa cells were isolated and cultured for 2 d. Cell proliferation (expression of PCNA) and apoptosis (expression of TdT) were evaluated by immunocytochemistry and TUNEL respectively. Secretion of P4, T, E2, IGF-I, and prostaglandin F (PGF) by granulosa cells cultured with and without LH or IGF-I (1, 10 or 100 ng/ml medium) was assessed by RIA. The remaining control and treated animals were kept until parturition, while the number, viability and body weight of pups were recorded.  相似文献   

16.
We examined whether progesterone (P4)-induced suppression of LH release in cattle can be overcome by an increased dose of exogenous gonadotropin-releasing hormone (GnRH) or pretreatment with estradiol (E2). In Experiment 1, postpubertal Angus-cross heifers (N = 32) had their 2 largest ovarian follicles ablated 5 d after ovulation. Concurrently, these heifers were all given a once-used, intravaginal P4-releasing insert (CIDR), and they were randomly assigned to be given either prostaglandin F2α (Low-P4) or no treatment (High-P4) at follicle ablation, and 12 h later. Six days after emergence of a new follicular wave, half of the heifers in each group (n = 8) were given either 100 or 200 μg of GnRH i.m. Plasma luteinizing hormone (LH) concentrations were higher in the Low- vs High-P4 groups, and in heifers given 200 vs 100 μg of GnRH (mean ± SEM 15.4 ± 2.2 vs 9.1 ± 1.2, and 14.8 ± 2.1 vs 9.8 ± 1.4 ng/mL, respectively; P ≤ 0.01). Ovulation rate was higher (P = 0.002) in the Low-P4 group (15/16) than in the High-P4 group (6/16), but it was not affected by GnRH dose (P = 0.4). In Experiment 2, heifers (n = 22) were treated similarly, except that 5.5 d after wave emergence, half of the heifers in each group were further allocated to be given either 0.25 mg estradiol benzoate i.m. or no treatment, and 8 h later, all heifers were given 100 μg GnRH i.m. Both groups treated with E2 (Low- and High-P4) and the Low-P4 group without E2 had higher peak plasma LH concentrations compared to the group with high P4 without E2 (12.6 ± 1.8, 10.4 ± 1.8, 8.7 ± 1.3, and 3.9 ± 1.2 ng/mL, respectively; (P < 0.04)). However, E2 pretreatment did not increase ovulation rates in response to GnRH (P = 0.6). In summary, the hypotheses that higher doses of GnRH will be more efficacious in inducing LH release and that exogenous E2 will increase LH release following treatment with GnRH were supported, but neither significantly increased ovulation rate.  相似文献   

17.
SUMMARY Vascular leakage induced by intradermal injection of histamine, bradykinin and serotonin alone and co-injected with prostaglandin E2 was measured in Greyhounds using 125Iodine-labelled human serum albumin (125I-HSA) as a marker in the blood. Histamine and bradykinin produced dose-dependent vascular leakage. At equimolar concentrations, histamine was more than twice as potent as bradykinin. Serotonin did not induce vascular leakage and was irritant. Prostaglandin E2 did not induce significant vascular leakage (maximum 5μL) when injected alone, but when co-injected with histamine and bradykinin, the vascular leakage of both histamine and bradykinin was increased. This effect was more pronounced if lower concentrations of histamine and bradykinin were injected. The induced vascular leakage was greatest during the first five minutes of lesion development for histamine, during the second five minutes of lesion development for bradykinin, and the synergistic effect of prostaglandin E2 was maximal during the third five minute period of lesion development.  相似文献   

18.
The object of this study was to investigate the role of epidermal growth factor (EGF) and IGF-I in the regulation of preantral follicular growth, antrum formation, and granulosal cell proliferation/ apoptosis. Porcine preantral follicles were manually dissected and cultured for up to 8 d in Waymouth's (Exp. 1) or alpha-minimum Eagle's essential medium (Exp. 2 and 3) supplemented with 10 microg/mL of transferrin, 100 microg/mL of L-ascorbic acid, and 2 mU/mL of ovine FSH, in the presence (Exp. 1 and 3) or absence (Exp. 2) of 7.5% fetal calf serum. According to the experimental protocol, IGF-I (0, 1, 10, or 100 ng/mL; Exp. 1), or IGF-I (50 ng/mL), EGF (10 ng/mL) and EGF+IGF-I (Exp. 2 and 3) were added to the culture media. In Exp. 1, follicles exhibited a concentration-dependent response (P < 0.05) to IGF-I, with the highest rates of granulosal cell proliferation, follicular integrity, and recovery rate of cumulus cell-oocyte complexes and lowest incidence of apoptosis occurring at the highest IGF-I dose. In Exp. 2 serum-free medium, granulosal cell proliferation was low (1 to 5%), irrespective of whether EGF and/or IGF-I were present and cellular apoptosis was increased (P < 0.05) on d 4 and 8 in the EGF+IGF-I group compared with the addition of either factor alone. In Exp. 3, granulosal cell proliferation was high in all follicles cultured in serum-containing medium for the first 3 d, but fell sharply (P < 0.05) on d 4, except in media containing IGF-I. Collectively, EGF and IGF-I increased granulosal cell proliferation, decreased apoptosis, and promoted follicular antrum formation. These results may provide useful information for developing a preantral follicular culture system in which the oocytes are capable of fertilization and embryonic development.  相似文献   

19.
Background: Myocarditis is thought to occur secondary to equine influenza virus (EIV) infections in horses, but there is a lack of published evidence. Hypothesis/Objectives: We proposed that EIV challenge infection in ponies would cause myocardial damage, detectable by increases in plasma cardiac troponin I (cTnI) concentrations. Animals: Twenty‐nine influenza‐naïve yearling ponies: 23 were part of an influenza vaccine study (11 unvaccinated and 12 vaccinated), and were challenged with 108 EID50 EIV A/eq/Kentucky/91 6 months after vaccination. Six age‐matched healthy and unvaccinated ponies concurrently housed in a separate facility not exposed to influenza served as controls. Methods: Heparinized blood was collected before and over 28 days after infection and cTnI determined. Repeated measures analysis of variance, chi‐square, or clustered regression analyses were used to identify relationships between each group and cTnI. Results: All EIV‐infected ponies developed clinical signs and viral shedding, with the unvaccinated group displaying severe signs. One vaccinated pony and 2 unvaccinated ponies had cTnI greater than the reference range at 1 time point. At all other times, cTnI was <0.05 ng/mL. All control ponies had normal cTnI. There were no significant associations between cTnI and either clinical signs or experimental groups. When separated into abnormal versus normal cTnI, there were no significant differences among groups. Conclusions and Clinical Importance: This study demonstrated no evidence of severe myocardial necrosis secondary to EIV challenge with 108 EID50 EIV A/eq/Kentucky/91 in these sedentary ponies, but transient increases in cTnI suggest that mild myocardial damage may occur.  相似文献   

20.
A liquid chromatography–tandem mass spectrometry method was developed to confirm the presence of androstenedione-19-oic acid in intact male equine plasma and to show the source of 19-norandrostenedione in equine plasma. Androstenedione-19-oic acid was recovered from acidified plasma by liquid–liquid extraction using methyl tert-butyl ether and separated on an Ace 5 C8 column. A triple quadrupole mass spectrometer was used to detect the analytes in negative electrospray ionization mode. Limits of detection, quantification, and confirmation of the method were 0.1, 0.5, and 1.0 ng/mL, respectively. The linear dynamic range of quantification was 0.5–50 ng/mL. The presence of androstenedione-19-oic acid was confirmed in all plasma samples obtained from intact male horses but not those from gelded and female horses; the average concentration was 3.1 ± 1.6 ng/mL, suggesting androstenedione-19-oic acid is an endogenous compound only in intact male horse plasma samples. The conversion of androstenedione-19-oic acid to 19-norandrostenedione in equine plasma was demonstrated by spiking androstenedione-19-oic acid into blank plasma and monitoring the generation of 19-norandrostenedione and its increase in concentration during storage. Results indicated that androstenedione-19-oic acid was readily converted into 19-norandrostenedione; the higher the storage temperature, the faster the conversion. The conversion was not affected by the types of plasma samples collected from gelded and female horses or by anticoagulants used in blood collection to harvest plasma. Compared with other matrices such as water, methanol, and phosphate-buffered saline, the conversion of androstenedione-19-oic to 19-norandrostenedione in equine plasma was faster, suggesting that there is an unknown factor(s) in equine plasma that enhances the conversion.  相似文献   

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