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Objective

To compare the effects of two concentrations of oxygen delivered to the anaesthetic breathing circuit on oxygenation in mechanically ventilated horses anaesthetised with isoflurane and positioned in dorsal or lateral recumbency.

Methods

Selected respiratory parameters and blood lactate were measured and oxygenation indices calculated, before and during general anaesthesia, in 24 laterally or dorsally recumbent horses. Horses were randomly assigned to receive 100% or 60% oxygen during anaesthesia. All horses were anaesthetised using the same protocol and intermittent positive pressure ventilation (IPPV) was commenced immediately following anaesthetic induction and endotracheal intubation. Arterial blood gas analysis was performed and oxygenation indices calculated before premedication, immediately after induction, at 10 and 45 min after the commencement of mechanical ventilation, and in recovery.

Results

During anaesthesia, the arterial partial pressure of oxygen was adequate in all horses, regardless of position of recumbency or the concentration of oxygen provided. At 10 and 45 min after commencing IPPV, the arterial partial pressure of oxygen was lower in horses in dorsal recumbency compared with those in lateral recumbency, irrespective of the concentration of oxygen supplied. Based on oxygenation indices, pulmonary function during general anaesthesia in horses placed in dorsal recumbency was more compromised than in horses in lateral recumbency, irrespective of the concentration of oxygen provided.

Conclusion

During general anaesthesia, using oxygen at a concentration of 60% instead of 100% maintains adequate arterial oxygenation in horses in dorsal or lateral recumbency. However, it will not reduce pulmonary function abnormalities induced by anaesthesia and recumbency.  相似文献   
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Oestrous detection is crucial for successful dairy cow reproduction. Bulls identify cows in oestrus by oestrous‐specific odours especially in urine and vaginal fluid. These have been used to train dogs to detect cows in heat. To improve and simplify the dog training, a spray containing synthetic oestrous molecules was developed. The objective of this study was to test the spray on similarities to the natural substance thus to assess its suitability as a training substance for heat detection dogs. Ten privately owned dogs of various breeds were trained. Dogs should be trained either to differentiate natural vaginal fluid from cows in oestrus and dioestrus (n = 5), or spray with or without synthetic oestrous molecules (n = 5). Dogs trained on natural fluid and on spray could detect the oestrous odour they had been trained on with an overall accuracy of 69.0% and 82.4%, respectively (p = 0.019). To validate the synthetic molecules, dogs trained with synthetic molecules had to detect oestrous odour in natural fluid without further training (accuracy 37.6%). Dogs trained on natural fluid detected the synthetic molecules with an accuracy of 50.0% (50% vs 37.4%, p < 0.05). Dogs can recognize natural vaginal fluid from cows in oestrus after they have been trained with synthetic oestrous molecules, but accuracy needs to be improved.  相似文献   
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Objective To assess the effects of the duration of anaesthesia, position of recumbency, mode of ventilation, anaesthetic drug protocol, patient age and type of surgical procedure on the usefulness of capnometry as a measure of the partial pressure of arterial carbon dioxide (Paco 2) during general anaesthesia in horses. Design A prospective study compared the Paco 2 values with those of partial pressure of end-tidal carbon dioxide (ETco 2) in horses anaesthetised for elective or emergency surgical procedures. The difference between Paco 2 and ETco 2 (Paco 2− ETco 2) and the physiological dead space to tidal volume ratio (VD/VT) were calculated. The effects of the study parameters on these variables was determined. Results The agreement between Paco 2 and ETco 2 was poor. Paco 2− ETco 2 and VD/VT during the first 60 min of anaesthesia was significantly less than after 60 min of anaesthesia. Mode of ventilation, position of recumbency, anaesthetic drug protocol, patient age and type of procedure did not have a significant affect on either value. Conclusions Paco 2− ETco 2 in anaesthetised horses can be large, making ETco 2 unreliable as a predictor of Paco 2 and for assessment of pulmonary ventilation. For anaesthesia lasting less than 60 min at least one blood gas analysis of an arterial blood sample is required to assess Paco 2− ETco 2. Arterial blood gas analysis should be repeated after 60 min of general anaesthesia.  相似文献   
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The objective of this research was to determine changes in IGF-I levels in serum and follicular fluid, and immunoreactivity of the follicle wall of cows with spontaneous (slaughter specimens) or ACTH-induced follicular cysts, and to compare results to normal cycling (control) cows after selection of the ovulatory follicle. Concentrations of IGF-I in serum did not differ between control and cystic animals (p=0.76). Fluid from the ovulatory follicle in control cows had 41% higher concentrations of IGF-I than that from cystic follicles collected at slaughter (spontaneous cysts; p<0.05) and 70% higher than that in induced follicular cysts (p<0.05). An intense positive immunostaining with anti-IGF-I was observed in granulosa cells (p<0.05) and in the theca interna (p<0.05) of secondary and tertiary follicles in all three groups of animals, but staining was less intense in cystic (p<0.05) and atretic follicles (p<0.05). This study provides evidence to suggest that cystic ovarian disease in cattle is associated with decreased concentrations of IGF-I in follicular fluid, but not in serum, and decreased production of IGF-I in the follicular wall. These data support the notion that IGF-I plays a role in the regulation of folliculogenesis, and may participate in the pathogenesis of cystic ovarian disease in cattle.  相似文献   
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Although basic fibroblast growth factor (bFGF) is an essential factor supporting the maintenance of porcine embryonic stem (ES) cell self‐renewal and pluripotency, its high cost has limited previous studies, and the development of a low‐cost culture system is required. For these systems, in vivo blastocysts were progressively cultured under various conditions consisting of different culture mediums and/or different feeder cell numbers at a low concentration of bFGF. As the results, the sequential culture of in vivo‐derived porcine blastocysts on 5.0 × 105 mouse embryonic fibroblast (MEF) feeder cells in alpha minimum essential medium‐based medium for primary culture, on 2.5 × 105 MEF feeder cells in Mixture medium for the 1st subpassage, and on 2.5 × 105 MEF feeder cells in DMEM/Ham's F10‐based medium for the post‐2nd subpassage could support the establishment and maintenance of porcine ES‐like cells at the low concentration of bFGF. The established porcine ES‐like cells showed ES cell‐specific characteristics such as self‐renewal and pluripotency. We confirmed that porcine ES‐like cells could be generated from in vivo‐derived porcine blastocysts at a low concentration of bFGF.  相似文献   
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The objective of this study was to examine the expression of transforming growth factor beta receptor (TGFBR)1, TGFBR2, TGFBR3, activin receptor (ACVR)1B and ACVR2B in ovaries of cows with cystic ovarian disease (COD). The expression of the selected receptors was determined by immunohistochemistry in sections of ovaries from cows with ACTH‐induced and spontaneous COD. Expression of TGFBR1 and TGFBR3 was higher in granulosa cells of cysts from cows with spontaneous COD than in tertiary follicles from the control group. Additionally, TGFBR3 expression was higher in granulosa cells of cysts from cows with ACTH‐induced COD than in those from the control group and lower in theca cells of spontaneous and ACTH‐induced cysts than in tertiary control follicles. There were no changes in the expression of TGFBR2. ACVR1B expression was higher in granulosa cells of tertiary follicles of cows with spontaneous COD than in the control group, whereas ACVR2B expression was higher in cysts of the spontaneous COD group than in tertiary follicles from the control group. The alterations here detected, together with the altered expression of the ligands previously reported, indicate alterations in the response of the ligands in the target cells, modifying their actions at cellular level.  相似文献   
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