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Kitching RP Hutber AM Thrusfield MV 《Veterinary journal (London, England : 1997)》2005,169(2):197-209
Modelling the epidemiology of foot-and-mouth disease (FMD) has been undertaken since the early 1970s. We review here clinical factors and modelling procedures that have been used in the past, differentiating between those that have proved to be more relevant in controlling FMD epidemics, and those that have showed less significance. During the 2001 UK FMD epidemic, many previously developed FMD models were available for consideration and use. Accurate epidemiological models can become useful tools for determining relevant control policies for different scenarios and, conversely, inaccurate models may become an abuse for disease control. Inaccuracy presents two opposing difficulties. Firstly, too much control (in terms of animal slaughter for 2001) would negatively impact the farming community for many subsequent years, whilst too little control would permit an epidemic to persist. Accuracy however, presents the optimal permutation of control measures that could be implemented for a given set of conditions, and is a prerequisite to boosting public confidence in the use of epidemiological models for future epidemics. 相似文献
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First-fortnight incidence (FFI) is a modelling parameter that can be used to predict both the prevalence and duration of a foot-and-mouth disease (FMD) epidemic at regional and national levels. With an indication of how long an epidemic may last by the end of week two, it becomes possible to estimate whether vaccination would be economically viable from the start of an epidemic. Where FFI indicates that an epidemic is unlikely to last for as long as an export ban on agricultural produce, it may be inappropriate to implement a policy of 'vaccination to live'. Alternatively where FFI indicates that an epidemic will equal or exceed the ban length, then the benefits of vaccination should be considered at an early stage, during or after the first fortnight. Since blanket vaccination of the national or regional herds and flocks would be both costly and heighten the risk of producing carrier animals, targetting vaccination through risk assessment becomes useful. 相似文献
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FRO de Barros RA Worst GCP Saurin CM Mendes MEOA Assumpção JA Visintin 《Reproduction in domestic animals》2012,47(6):887-890
The study of spermatogonial stem cells (SSCs) provides a model to better understand adult stem cell biology. Besides the biomedical potential to perform studies of infertility in many species, SSCs hold a promising application at animal transgenesis. Because stem cells are thought to be associated with basement membranes, expression of α‐6 integrin has been investigated as a marker of type A spermatogonial cells, which are considered SSCs because of their undifferentiated status and self‐renewal ability. In this manner, the aim of this study was to isolate type A SSCs from adult bulls by a two‐step enzymatic procedure followed by a discontinuous Percoll density gradient purification and verify the expression of α‐6 integrin by flow cytometry and real‐time RT‐PCR before and after Percoll purification. Spermatogonial cells were successfully obtained using the two‐step enzymatic digestion. An average of 1 × 105 viable cells per gram of testis was isolated. However, the discontinuous Percoll did not purify isolated cells regarding α‐6 integrin expression. Flow cytometry analysis demonstrated no differences in the α‐6 integrin expression between cell samples before and after Percoll purification (p = 0.5636). The same was observed in the real‐time PCR analysis (p > 0.05). In addition to α‐6 integrin, the expression of GFRa‐1 and PGP9.5, known bovine SSCs markers, was detected in all samples studied. Considering that Percoll can reduce cell viability, it is possible to conclude that Percoll density gradient is not suitable to purify bovine SSC, according to α‐6 integrin expression. 相似文献
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Sevoflurane has recently been introduced in feline anesthesia. However, its cardiovascular effects have not, to our knowledge, been reported in this species. Six healthy cats, aged 1.81 ± 0.31 years (mean ± SEM) and weighing 3.47 ± 0.11 kg, were studied. Anesthesia was induced and maintained with sevoflurane in oxygen. Body temperature was maintained between 38.5 and 39.55 °C. After instrumentation, end‐tidal sevoflurane concentration was randomly set at 1.25, 1.5, and 1.75 times the individual minimum alveolar concentration (MAC), determined in a previous study, according to a Latin Square Design. Thirty minutes of stabilization was allowed after each change of concentration. ECG and heart rate, systemic and pulmonary arterial pressures, central venous pressure (CVP), and core body temperature were continuously monitored and recorded. Inspired and end‐tidal oxygen, carbon dioxide, and sevoflurane concentrations were measured using a Raman spectrometer, calibrated every 80 minutes with three calibration gases of known sevoflurane concentration (1, 2, and 5%). Moreover, at selected times, pulmonary artery occlusion pressure and cardiac output (thermodilution) were measured, and arterial and mixed venous blood samples were collected for pH and blood gas analysis, hemoglobin concentration, hemoglobin oxygen saturation, packed cell volume (PCV) and total protein determination, and lactate concentration measurement. Cardiac index (CI), stroke index (SI), systemic and pulmonary vascular resistance indices, rate‐pressure product, left and right ventricular stroke work indices (LVSWI and RVSWI, respectively), arterial and mixed venous oxygen contents, oxygen delivery, oxygen consumption, and oxygen utilization ratio were calculated. Data were analyzed by a Repeated Measure Latin Square Design followed by a Tukey's test for 2 × 2 comparisons. Arterial pH significantly decreased from 7.40 ± 0.05 to 7.29 ± 0.07 with the administration of increasing concentrations of sevoflurane. Similarly, LVSWI decreased from 3.72 ± 0.60 to 2.60 ± 0.46 g m?2. Mean arterial pressure, PaO2, mixed venous pH, CI, SI, and oxygen delivery tended to decrease dose‐dependently, whereas CVP, PaCO2, Pv CO2, PCV, and arterial and mixed venous hemoglobin concentrations tended to increase dose‐dependently with the administration of sevoflurane. However, these trends did not reach statistical significance, possibly because of the limited number of animals studied. Sevoflurane seemed to induce dose‐dependent cardiovascular depression in cats. 相似文献
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Identification of RSVP14 and RSVP20 components by two-dimensional electrophoresis and Western-blotting. 总被引:1,自引:0,他引:1
JA Cardozo M Fernández‐Juan JA Cebrián‐Pérez T Muiño‐Blanco 《Reproduction in domestic animals》2008,43(1):15-21
We have already shown that RSVP14 and RSVP20, two ram seminal plasma (SP) proteins postulated to be involved in sperm capacitation and gamete interaction can protect spermatozoa against cold-shock. In this study, we use two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) for the analysis of SP proteins of Rasa Aragonesa rams, using enhanced protein solubilization in the presence of tributyl phosphine (TBP) and a polyacrylamide linear gradient gel with a narrow pH range (4-7). The image analysis of the 2D map detected 195 protein spots, with isoelectric points (pIs) ranging from 4.5 to 6.6, and molecular weight (M(r)) from 11.7 to 90.4. Staining of 2D gels with Pro-Q Emerald 300 Glycoprotein Stain revealed that most significant proteins in ram SP are glycosylated. The removing of protein N-linked oligosaccharides improved the gel resolution. 2D-PAGE analysis of the whole fraction 6 (F6) separated from ram SP by exclusion chromatography showed six main protein spots, four (a, b, c, d) in the 14 kDa and two (e, f) in the 20 kDa region. Western-blot analyses indicated that the anti-P14 antibody recognized four spots on the SP map, 4, 5, 6 and 7, that matched with spots a, b, c, d of F6 map. The anti-P20 antibody recognized spots 13 and 14 of SP map that corresponded to spots e, f of F6 map. The deduced sequences by de novo sequencing evidenced that protein spots 7 and 13 have significant similarities to BSP family, while protein spots 4 and 14 did not appear to be homologous with any reported protein in the current mammalian Proteinbank databases. 相似文献