Real-time ultrasonography for pregnancy diagnosis and foetal ageing in fallow deer     

MF LENZ  AW ENGLISH  A DRADJAT 《Australian veterinary journal》1993,70(10):373-375

SUMMARY Three groups of 15 to 17 adult fallow does with some additional yearling does in 2 of the groups were treated to synchronise oestrous cycles, and mated. All does were scanned by ultrasound at 4 weeks of gestation and at weekly intervals from week 7 to week 14 of gestation. Growth rates of 13 foetal and uterine characters, which have been used for ageing foetuses of red deer, were similar for adult and yearling does and among the 3 groups. Transrectal ultrasound scanning was a reliable and accurate means of detecting pregnancy and of ageing foetuses of fallow deer during weeks 7 to 17 of pregnancy.  相似文献   

Correlation of hematological changes and serum and monocyte inhibition with the early suppression of phytohemagglutinin stimulation of lymphocytes in experimental infectious bursal disease.   总被引：1，自引：0，他引：1       下载免费PDF全文

A W Confer  P S MacWilliams 《Canadian journal of veterinary research》1982,46(2):169-175

Several experiments were conducted to study the mechanism of infectious bursal disease virus induced suppression of phytohemagglutinin stimulation of peripheral blood lymphocytes. Infectious bursal disease virus inoculation of one week old chicks resulted in significant suppression of phytohemagglutinin stimulation during the first three days after inoculation as demonstrated by a whole blood assay. Mild thymic necrosis was seen on day 3. Hematological changes during this time consisted of increased numbers of circulating lymphocytes and monocytes in infected chickens. Absolute monocyte counts remained elevated even after phytohemagglutinin stimulation had returned to normal. Furthermore, even after a 72.3% reduction in the monocyte population in leukocyte preparations, there was still marked viral induced suppression of phytohemagglutinin stimulation. An elevation in the absolute number of circulating large immature lymphocytes correlated with suppression of phytohemagglutinin stimulation. Sera from infected and control chickens depressed phytohemagglutinin stimulation of lymphocytes from control chickens at the 5 and 10% concentration. At the 1% concentration, inhibiton by control sera was considerably less than the inhibition by infected sera. The relationship between these findings and the mechanism of viral induced suppression of T-lymphocyte function is discussed.  相似文献   

The effect of autonomic manipulation on heart rate variability in dogs     

AM McCoig  JR Dodam  AW Spier  HL Shafford 《Veterinary anaesthesia and analgesia》2005,32(4):6-6

Beat‐to‐beat variation of heart rate is reflective of autonomic balance and has been used to assess pain and stress in human beings. The purpose of this investigation was to pharmacologically manipulate the autonomic nervous system and to determine the effect of these manipulations on heart rate variability (HRV) in dogs. Four adult male hound dogs (27 ± 1 kg) were used in the investigation. Each dog was given five treatments: Parasympathetic blockade (glycopyrrolate; 0.01 mg kg^–1 IV and 0.01 mg kg^–1 IM), parasympathetic stimulation (phenylephrine; 0.005 mg kg^–1 IV + 0.05 mg kg^–1hour^–1), sympathetic blockade (propranolol; 0.11 mg kg^–1 IV), sympathetic stimulation propranolol; 0.01 μg kg^–1 minute^–1), and saline control. At least 48 hours were allowed between treatments. ECG recordings were obtained using an ambulatory ECG monitor. A 5‐minutes period of continuous recording obtained ~30 minutes after initiation of drug administration was used for data analysis. Changes in HRV were evaluated by time and frequency‐domain analysis. The standard deviation of normal R‐R intervals (SDNN), as well as the standard deviation of successive differences in RR intervals (SDSD) were assessed for each treatment. Low frequency (LFP; 0.05–0.15 Hz), high frequency (HFP; 0.15–0.35 Hz), and total (TP; 0.017–0.5 Hz) spectral power were also determined. The LFP:HFP ratio was also evaluated. A two‐way anova with a Tukey's test was used to detect differences (p < 0.05). Administration of glycopyrrolate or isoproterenol increased HR and decreased SDNN and SDSD below control levels. Phenylephrine or propranolol administration were without effect. LFP was diminished by glycopyrrolate and isoproterenol, but was unaffected by phenylephrine and propranolol. HFP, TP, and LFP:HFP were unaffected by treatment. Both branches of the autonomic nervous system influence SDNN and LFP. SDSD, in contrast, is altered primarily by parasympathetic activity. Thus, it appears that parasympathetic activity modulates HRV in the resting dog, as either withdrawal of parasympathetic influence or accentuated sympathetic activity led to significant changes in these measures of HRV. Conversely, augmentation of parasympathetic activity or withdrawal of sympathetic tone minimally affected HRV.  相似文献   

A tool for identifying potential Eucalyptus nitens seed orchard sites based on climate and topography     

Ilaria Germishuizen  Robin AW Gardner 《Southern Forests》2015,77(2):123-130

Shy seed production in orchards of Eucalyptus nitens is a major barrier to the deployment of genetic gain in South African plantations. A machine learning method was used to identify optimal sites for the establishment of E. nitens seed orchards within the plantation forestry landscape of the summer rainfall region of South Africa. The ensemble classifier random forests (RF) was used to identify the environmental factors conducive to E. nitens floral bud production, and, based on these, build a predictive model deployable to the plantation forestry landscape for identifying suitable areas for E. nitens seed orchards. The RF model predicted site suitability likelihood for floral bud production with a high level of accuracy (area under the receiver operating characteristic curve = 0.83). Within the climatically optimal range for growing E. nitens, flower bud production was more abundant and consistent on cold slopes, i.e. sites experiencing lower minimum air temperatures during spring and autumn. The model was applied to the commercial plantation forestry landscape for the purpose of indicating sites climatically optimal for floral bud production in E. nitens and the establishment of breeding and seed production orchards of the same species.  相似文献   

Pasteurella haemolytica: purification of saline-extractable proteins by isoelectrofocusing   总被引：1，自引：0，他引：1  

K L McKinney  A W Confer  J A Rummage  M J Gentry  J A Durham 《Veterinary microbiology》1985,10(5):465-480

A procedure was developed for separating antigens associated with a saline extract of Pasteurella haemolytica serotype 1. Seven antigens were identified by immunoelectrophoresis to be associated with the extract. The extract was subjected to preparative isoelectrofocusing in a pH range of 3-10. The majority of extracted proteins were found to have pI's of 4-6, whereas the carbohydrate antigen(s) were distributed over a pI range of 3.0-8.0. The fractions that were of interest were pooled and refocused in a narrower pH range to improve resolution of the protein antigens. Specific antigens from defined pH ranges were pooled to form 6 antigen groups. These antigen groups were examined further by immunoelectrophoresis, analytical isoelectrofocusing, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The molecular weights of the proteins found in the capsular extracts ranged from 33 k to greater than 80 k. Injection of mice with capsular extract or antigen Groups 1-6 in Freund's incomplete adjuvant resulted in a serum antibody response to the various antigens as detected by an enzyme-linked immunosorbent assay. Significant protection (P less than 0.05) against challenge with virulent P. haemolytica was seen in mice injected with antigen Groups 2 and 4. Six calves were immunized with saline extract. These calves had greater resistance to experimental pneumonic pasteurellosis than did 6 non-vaccinated calves. A serum antibody response to the crude extract and to each antigen group was detected in vaccinated calves by an enzyme-linked immunosorbant assay.  相似文献   

Bovine viral diarrhea virus cytopathic and noncytopathic biotypes and type 1 and 2 genotypes in diagnostic laboratory accessions: clinical and necropsy samples from cattle.     

R W Fulton  J T Saliki  A W Confer  L J Burge  J M d'Offay  R G Helman  S R Bolin  J F Ridpath  M E Payton 《Journal of veterinary diagnostic investigation》2000,12(1):33-38

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Colossal Magnetoresistance Without Mn3+/Mn4+ Double Exchange in the Stoichiometric Pyrochlore Tl2Mn2O7     

MA Subramanian  BH Toby  AP Ramirez  WJ Marshall  AW Sleight  GH Kwei 《Science (New York, N.Y.)》1996,273(5271):81-84

Structural analysis from powder neutron and single-crystal x-ray diffraction data for a sample of the Tl2Mn2O7 pyrochlore, which exhibits colossal magnetoresistance (CMR), shows no deviations from ideal stoichiometry. This analysis gives an Mn-O distance of 1.90 angstroms, which is significantly shorter than the Mn-O distances (1.94 to 2.00 angstroms) observed in phases based on LaMnO3 perovskites that exhibit CMR. Both results in Tl2Mn2O7 indicate oxidation states very close to Tl23+Mn24+O7. Thus, Tl2Mn2O7 has neither mixed valence for a double-exchange magnetic interaction nor a Jahn-Teller cation such as Mn3+, both of which were thought to have an important function in CMR materials. An alternate mechanism for CMR in Tl2Mn2O7 based on magnetic ordering driven by superexchange and strong spin-fluctuation scattering above the Curie temperature is proposed here.  相似文献   

Bovine coronavirus (BCV) infections in transported commingled beef cattle and sole-source ranch calves     

Fulton RW  Step DL  Wahrmund J  Burge LJ  Payton ME  Cook BJ  Burken D  Richards CJ  Confer AW 《Canadian journal of veterinary research》2011,75(3):191-199

This study investigated bovine coronavirus (BCV) in both beef calves direct from the ranch and commingled, mixed-source calves obtained from an auction market. The level of BCV-neutralizing antibodies found in the calves varied among ranches in 2 different studies in a retained-ownership program (ROP), from the ranch to the feedlot. Calves with low levels of BCV-neutralizing antibodies (16 or less) were more likely to be treated for bovine respiratory disease (BRD) than those with higher titers. In 3 studies of commingled, mixed-source calves, BCV was recovered from calves at entry to the feedlot and the infections were cleared by day 8. The BCV was identified in lung samples [bronchoalveolar lavage (BAL) collection] as well as in nasal swabs. Calves with low levels of BCV-neutralizing antibodies at entry were most likely to be shedding BCV. Bovine coronavirus was isolated from both healthy and sick calves, but not from sick calves after 4 d arrival at the feedlot. Bovine coronavirus (BCV) should be considered along with other bovine respiratory viruses in the diagnosis of etiologies in bovine respiratory disease, especially for animals that become sick shortly after arrival. If approved vaccines are developed, it would be best to carry out vaccination programs before calves are weaned, giving them sufficient time to gain active immunity before commingling with other cattle.  相似文献   

Phagocyte impotence caused by an invasive bacterial adenylate cyclase   总被引：69，自引：0，他引：69  

D L Confer  J W Eaton 《Science (New York, N.Y.)》1982,217(4563):948-950

For unknown reasons, humans infected with the bacterium Bordetella pertussis are exceptionally vulnerable to secondary infections. Bordetella species elaborate a soluble, heat-stable, and highly active adenylate cyclase. This enzyme is internalized by phagocytic cells and catalyzes the unregulated formation of adenosine 3',5'-monophosphate (cyclic AMP), thereby disrupting normal cellular function. This unusual phenomenon may explain Bordetella-induced aphylaxis and may prove to be useful for investigating a variety of cyclic AMP-governed processes.  相似文献   

Cytotoxicity and cytokine production by bovine alveolar macrophages challenged with wild type and leukotoxin-deficient Mannheimia haemolytica     

Kuldeep Singh  Anthony W. Confer  Jayne C. Hope  Theresa Rizzi  John H. Wyckoff III  Hsin-Yi Weng  Jerry W. Ritchey 《Veterinary journal (London, England : 1997)》2011,188(2):221-227

The aim of this study was to investigate the use of ultrasound (US) guidance to perform sciatic and saphenous nerve blocks in dogs. Five dogs were sedated with medetomidine and butorphanol. A high-resolution US transducer was used to locate the nerves, guide placement of the needle and visualise the perineural injection of lidocaine 2%. Electrostimulation was used to confirm correct placement prior to the sciatic block. Nerve functions were evaluated over a 3 h period following administration of atipamezole. Successful identification of the nerves and the quality of the blocks were recorded. Location of the nerves, complete sensory block of the saphenous nerve, and partial to complete sensory and motor blocks of the sciatic nerve were achieved in all dogs. The resultant US guidance is potentially valuable for blocking the sciatic and saphenous nerves in dogs, although further work will be required to ensure a complete block of the sciatic nerve.  相似文献