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11.
Studies have demonstrated that oviductal fluid (ODF) proteins associate with eggs of numerous species including the bovine. In this study, the association of three ODF proteins, the bovine oestrus‐associated protein, osteopontin (OPN), lipocalin‐type prostaglandin D synthase (L‐PGDS), with the bovine zona pellucida (ZP) was demonstrated by immunohistochemistry and western blot. The biological function of ODF derived egg‐associated OPN and L‐PGDS in sperm binding, fertilization and embryonic development was also explored. In vitro matured bovine oocytes were pre‐incubated with ODF collected by cannula from cows in oestrus, or ODF with antibodies to OPN, L‐PGDS and bovine serum albumin (BSA). Following incubation, oocytes were inseminated with 1 × 105 frozen‐thawed spermatozoa, and they were evaluated for sperm binding, fertilization and embryonic development in vitro. Pre‐treatment of ODF with antibodies to all of proteins reduced sperm binding to the ZP and fertilization in vitro. Cleavage rates were not significantly different among incubations, but rates of embryo development were significantly decreased. We conclude that antibodies to OPN, L‐PGDS and BSA react with oocytes incubated with ODF and inhibit sperm binding, fertilization and embryonic development in vitro, suggesting a potential role of these proteins in these events. 相似文献
12.
The present study aims at ascertaining the influence of α1‐adrenoreceptors on arginine vasopressin (AVP) release in vitro and determine whether E2 modulates the α1‐adrenoreceptor and AVP interaction. Ten minutes after ewe killing, sagittal midline hypothalamic slices (from the anterior preoptic area to the mediobasal hypothalamus with the median eminence, 2 mm thick, 2 per sheep) were dissected, placed in oxygenated minimum essential media‐α (MEM‐α) at 4°C and within 2 h were singly perifused at 37°C with oxygenated MEM‐α (pH 7.4; flow rate 0.15 ml/min), either with or without E2 (24 pg/ml). After 4 h equilibration, 10 min fractions were collected for 4 h interposed with 10 min exposure at 60 min to a specific α1‐adrenoreceptor agonist or antagonist at various doses (0.1–10 mm ). At the end of all perifusions, slices responded to KCl (100 mm ) with AVP efflux (p < 0.05). Release of AVP was enhanced (p < 0.05) by the α1‐adrenoreceptor agonist (methoxamine 10 mm ; no E2, n = 7 perifusion chambers: from 14.3 ± 2.7 to 20.9 ± 3.9, with E2, n = 10: from 10.7 ± 1.2 to 18.4 ± 3.4 pg/ml) or the antagonist (thymoxamine 10 mm ; no E2, n = 5: from 9.5 ± 3.1 to 30.4 ± 6.0, with E2, n = 10: from 10.8 ± 0.9 to 39.1 ± 6.3 pg/ml). With the agonist, the response occurred only at 80 min (p < 0.05) both in the presence and absence of E2. Whereas, after the antagonist, values were higher (p < 0.05) throughout the post‐treatment period (80–170 min) without E2, but declined by 150 min in the presence of E2. Furthermore, the response to the α1‐adrenoreceptor antagonist was greater (p < 0.05; 90–140 min) than the agonist only in the presence of E2. In conclusion, these results reveal direct α1‐adrenoreceptor‐mediated control of the hypothalamic AVP neuronal system which is modulated by E2. 相似文献
13.
Clinical and pathological studies of a neurological disorder of 3 adult Rottweiler dogs are described. Dogs developed proprioceptive losses involving the limbs, leading to progressively worsening ataxia and hypermetria. Blood and CSF fluid analyses were normal and radiographs and myelograms showed no compressive lesions of the spinal cord. At necropsy, severe demyelination of the dorsal and lateral funiculi of the cervical spinal cord was visible grossly. Microscopically there was more extensive, symmetrical involvement of the spinal cord and brain than was apparent grossly, with demyelination of white matter tracts and sparing of axons in affected areas. These changes were considered diagnostic for leucoencephalomyelopathy. This condition has not been previously reported in Australia, and is probably transmitted genetically, presumably as an autosomal recessive trait. 相似文献
14.
JK Harmon SJ Ostro LAM Benner KD Rosema RF Jurgens R Winkler DK Yeomans D Choate R Cormier JD Giorgini DL Mitchell PW Chodas R Rose D Kelley MA Slade ML Thomas 《Science (New York, N.Y.)》1997,278(5345):1921-1924
Radar observations of comet Hyakutake (C/1996 B2) made at the Goldstone Deep Space Communications Complex in California have detected echoes from the nucleus and from large grains in the inner coma. The nucleus of this bright comet was estimated to be only 2 to 3 kilometers in diameter. Models of the coma echo indicate backscatter from porous, centimeter-size grains ejected anisotropically at velocities of tens of meters per second. The radar observations suggest that a comet's activity may be a poor indicator of its size and provide evidence that large grains constitute an important component of the mass loss from a typical active comet. 相似文献
15.
PJ HUNTINGTON S. SENEQUE† RF SLOCOMBE† LB JEFFCOTT† A. MCLEAN† AR LUFF§ 《Australian veterinary journal》1991,68(7):221-224
Five horses with Australian stringhalt were treated with 15 mg/kg phenytoin orally for 2 weeks. During the second week of the trial, 3 of the horses were given an additional dose of 10 mg/kg phenytoin. The response to treatment was clinically assessed by grading the severity of the gait abnormality at the walk, trot, turning and backing twice daily. There was a significant (P less than 0.05) improvement in the gait abnormality when pre-treatment values were compared with the mean of the last 3 assessments before treatment stopped. When reassessed 2 weeks after treatment ceased, there remained a significant (P less than 0.05) improvement compared with pre-treatment values at the trot and on backing, but not at the walk or turning. Surface electromyographic recordings were made weekly from the long digital extensor muscle, and there was a change to a near normal recording by the end of treatment. Plasma phenytoin concentrations were monitored during the trial, and the dose rates used achieved a steady state with a mean plasma level of 37 +/- 7 mumol/l. There was wide variability between plasma concentrations in different horses, although there was no difference in absorption between administration of the phenytoin as a paste, or when it was mixed in the feed. Although mild tranquilization was seen after treatment, there were no clinical, haematological or biochemical signs of toxicity from the phenytoin therapy. 相似文献
16.
How did meat emerge to become such an important feature in Western society? In both popular and academic literatures, biophysical and political-economic factors are often cited as the reason for meat’s preeminent status. In this paper, we perform a comprehensive investigation of these claims by reviewing the available evidence on the political-economic and biophysical features of meat over the long arc of Western history. We specifically focus on nine critical epochs: the Paleolithic (200,000 YA—10,000 YA), early to late Neolithic (10,000 YA—2500 BCE), antiquity (2500 BCE—550 CE), ancient Israel and early Christian societies (1550 BCE—379 CE), medieval Europe (476 CE—1400 CE), early modern Europe (1400–1800), colonial America (1607–1776), the American frontier (1776–1890), and the modern industrial era (1890—present). We find that except under conditions of environmental scarcity, the meaning and value of meat cannot be attributed to intrinsic biophysical value or to the political-economic actors who materially benefit from it. Rather, meat’s status reflects the myriad cultural contexts in which it is socially constructed in people’s everyday lives, particularly with respect to religious, gender, communal, racial, national, and class identity. By deconstructing the normalized/naturalized materialist assumptions circling around meat consumption, this paper clears a space for a more nuanced appreciation of the role that culture has played in the legitimation of meat, and by extension, the possibility of change. 相似文献
17.
HJ Williams SG Revell SFE Scholes AE Courtenay RF Smith 《Reproduction in domestic animals》2010,45(5):e212-e216
On assessment for use in an AI stud, a 12‐month‐old bull was found to produce low volume ejaculates with 41% of the sperm having morphological abnormalities. No left epididymal tail was palpable and the head of the epididymis on the left was twice the size compared with the right. Ultrasound examination showed the left testis to contain a large central area of decreased echogenicity, which could be followed proximally to a 15‐mm echolucent lesion at the site of the epididymal head. Postmortem examination revealed a 15‐mm diameter cyst in the region of the left epididymal head, and absence of the body and tail of the epididymis. The mediastinum testis of the left testis was dilated, corresponding to the area of decreased echogenicity observed on ultrasonography. No left seminal vesicle was present and the ampulla was significantly smaller than the same structure on the right. Histological examination revealed incomplete or absent spermatogenesis involving the majority of seminiferous tubules in the left testis, and a small proportion of those of the right testis. The cystic structure at the site of the left epididymal head was lined by irregular, sometimes attenuated, epithelium and contained sparse spermatozoa. This case demonstrates the adverse impact, which segmental aplasia of the mesonephric duct had on the testicular and epididymal function of a bull, and highlights the importance of careful clinical assessment in its diagnosis. 相似文献
18.
Four cases of megaoesophagus secondary to tiger snake envenomation are reported. History in all cases suggested megaoesophagus was not present prior to snake envenomation. Diagnosis of megaoesophagus was confirmed by thoracic radiography in all cases. One dog died of respiratory failure. The remaining three dogs recovered, with gradual resolution of clinical signs associated with megaoesophagus. 相似文献
19.
Nelson DM Gardner IA Chiles RF Balasuriya UB Eldridge BF Scott TW Reisen WK Maclachlan NJ 《Comparative immunology, microbiology and infectious diseases》2004,27(3):209-215
Jamestown Canyon (JC) and Saint Louis encephalitis (SLE) viruses are mosquito-transmitted viruses that have long been present in California. The objective of this study was to determine the seroprevalence of these two viruses in horses prior to the introduction of West Nile (WN) virus. Approximately 15% of serum samples collected in 1998 from 425 horses on 44 equine operations horses throughout California had serum antibodies to JC virus, whereas antibodies were not detected to SLE virus. The results indicate that horses in California were commonly infected prior to 1998 with mosquito-transmitted Bunyaviruses that are identical or closely related to JC virus, but not with SLE virus. The different seroprevalence of SLE and JC viruses in horses likely reflects the unique ecology of each virus, and it is predicted that WN virus will have a wider distribution in California than closely related SLE virus. 相似文献
20.
Robert Magneson Chiles 《Agriculture and Human Values》2013,30(4):511-523
According to recent literature in the sociology of expectations, expectations about the future are “performative” in that they provide guidance for activities, attract attention, mobilize political and economic resources, coordinate between groups, link technical and social concerns, create visions, and enroll supporters. While this framework has blossomed over the past decade in science and technology studies, it has yet to be applied towards a more refined understanding of how the future of the modern agrofood system is being actively contested and understood. I seek to redress this gap by using the sociology of expectations to explain the discursive topography surrounding in vitro meat, a nascent agrofood technology whereby processed meat products are developed from stem cells as opposed to live animals. In discussing the obstacles and challenges which confront the proponents of this technology, I utilize three key concepts from the sociology of expectations: (1) hype, (2) retrospective prospects, and (3) the role of myth, metaphor, and ideology. I find that despite sluggish results and financial setbacks, the controversial legacy of previous agrofood technologies, and persistent cultural skepticism, the core ideological justifications for in vitro meat have proven to be resilient in buoying the technology through rough discursive waters. 相似文献