The embryonic vertebrate heart tube is a dynamic suction pump     

Forouhar AS  Liebling M  Hickerson A  Nasiraei-Moghaddam A  Tsai HJ  Hove JR  Fraser SE  Dickinson ME  Gharib M 《Science (New York, N.Y.)》2006,312(5774):751-753

The embryonic vertebrate heart begins pumping blood long before the development of discernable chambers and valves. At these early stages, the heart tube has been described as a peristaltic pump. Recent advances in confocal laser scanning microscopy and four-dimensional visualization have warranted another look at early cardiac structure and function. We examined the movement of cells in the embryonic zebrafish heart tube and the flow of blood through the heart and obtained results that contradict peristalsis as a pumping mechanism in the embryonic heart. We propose a more likely explanation of early cardiac dynamics in which the pumping action results from suction due to elastic wave propagation in the heart tube.  相似文献   

Intraosseous epidermoid cyst of the third phalanx in a thoroughbred gelding     

Fraser B  Else RW  Jones E 《The Veterinary record》2006,159(11):360-362

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Description of the first case of equine infectious anaemia in Northern Ireland     

Menzies F  Patterson T 《The Veterinary record》2006,159(22):753-754

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New strategies for the elimination of polio from India     

Grassly NC  Fraser C  Wenger J  Deshpande JM  Sutter RW  Heymann DL  Aylward RB 《Science (New York, N.Y.)》2006,314(5802):1150-1153

The feasibility of global polio eradication is being questioned as a result of continued transmission in a few localities that act as sources for outbreaks elsewhere. Perhaps the greatest challenge is in India, where transmission has persisted in Uttar Pradesh and Bihar despite high coverage with multiple doses of vaccine. We estimate key parameters governing the seasonal epidemics in these areas and show that high population density and poor sanitation cause persistence by not only facilitating transmission of poliovirus but also severely compromising the efficacy of the trivalent vaccine. We analyze strategies to counteract this and show that switching to monovalent vaccine may finally interrupt virus transmission.  相似文献   

The efficacy of a combined oral formulation of derquantel-abamectin against anthelmintic resistant gastro-intestinal nematodes of sheep in the UK     

Geurden T  Hodge A  Noé L  Winstanley D  Bartley DJ  Taylor M  Morgan C  Fraser SJ  Maeder S  Bartram D 《Veterinary parasitology》2012,189(2-4):308-316

The objective of the present studies was to evaluate the efficacy of a combined formulation (Startect(?) Dual Active Oral Solution for Sheep, Pfizer Animal Health) of derquantel (DQL) and abamectin (ABA) for the treatment of: (1) sheep experimentally infected with a moxidectin (MOX)-resistant isolate of Teladorsagia circumcincta, and (2) multi-drug resistant gastrointestinal nematode parasites under UK field conditions. In the first study, a total of 40 animals were allocated into 4 treatment groups, and were either left untreated or treated with DQL+ABA, MOX or ABA. Faecal samples were collected on days 1-5 and on day 7 after treatment to examine the reduction in faecal egg excretion and to evaluate the egg viability. On day 14 post treatment all animals were euthanised for abomasal worm counts. There was a 100% reduction in geometric mean worm counts for the DQL+ABA treated animals compared to the untreated control animals (P<0.0001), whereas the percentage reduction in worm counts for the MOX- (P>0.05) and ABA-treated (P=0.0004) animals was 12.4% and 71.8%, respectively. The data from the egg hatch assay (EHA) indicated that in the MOX-treated and the ABA-treated animals, the majority of the eggs hatched after treatment. In the field study, performed on four farms, animals were allocated into 6 groups of 11-15 animals each in order to conduct a faecal egg count reduction test (FECRT), based on arithmetic mean egg counts. One group of animals remained untreated, whereas the other animals were treated with DQL+ABA, MOX, fenbendazole (FBZ), levamisole (LV) or ivermectin (IVM). On each of the farms the reduction in egg excretion after treatment with FBZ, LV or IVM was below 95.0%, indicating anthelmintic resistance. The efficacy of DQL+ABA ranged from 99.1 to 100%, yielding significantly lower egg counts compared to the untreated control group (P≤0.003). For MOX the egg counts were significantly (P≤0.003) lower compared to the untreated group at each farm, with reductions varying from 98.2 to 100%. The post-treatment copro-cultures for larva identification indicated that T. circumcincta was the most abundant worm species after treatment (52-99% of the larvae). The results of these studies confirm the high efficacy of the DQL+ABA combination formulation against anthelmintic resistant nematodes in the UK.  相似文献   

The contribution of simple random sampling to observed variations in faecal egg counts     

Torgerson PR  Paul M  Lewis FI 《Veterinary parasitology》2012,188(3-4):397-401

It has been over 100 years since the classical paper published by Gosset in 1907, under the pseudonym "Student", demonstrated that yeast cells suspended in a fluid and measured by a haemocytometer conformed to a Poisson process. Similarly parasite eggs in a faecal suspension also conform to a Poisson process. Despite this there are common misconceptions how to analyse or interpret observations from the McMaster or similar quantitative parasitic diagnostic techniques, widely used for evaluating parasite eggs in faeces. The McMaster technique can easily be shown from a theoretical perspective to give variable results that inevitably arise from the random distribution of parasite eggs in a well mixed faecal sample. The Poisson processes that lead to this variability are described and illustrative examples of the potentially large confidence intervals that can arise from observed faecal eggs counts that are calculated from the observations on a McMaster slide. Attempts to modify the McMaster technique, or indeed other quantitative techniques, to ensure uniform egg counts are doomed to failure and belie ignorance of Poisson processes. A simple method to immediately identify excess variation/poor sampling from replicate counts is provided.  相似文献   

UNIQUE TOPOGRAPHIC DISTRIBUTION OF GREYHOUND NONSUPPURATIVE MENINGOENCEPHALITIS     

Eloisa Terzo  J. Fraser McConnell  Robert E. Shiel  Hester McAllister  Sebastien Behr  Simon L. Priestnall  Ken C. Smith  Catherine M. Nolan  John J. Callanan 《Veterinary radiology & ultrasound》2012,53(6):636-642

Greyhound nonsuppurative meningoencephalitis is an idiopathic breed‐associated fatal meningoencephalitis with lesions usually occurring within the rostral cerebrum. This disorder can only be confirmed by postmortem examination, with a diagnosis based upon the unique topography of inflammatory lesions. Our purpose was to describe the magnetic resonance (MR) imaging features of this disease. Four Greyhounds with confirmed Greyhound nonsuppurative meningoencephalitis were evaluated by MR imaging. Lesions predominantly affected the olfactory lobes and bulbs, frontal, and frontotemporal cortical gray matter, and caudate nuclei bilaterally. Fluid attenuation inversion recovery (FLAIR) and T2 weighted spin‐echo (T2W) sequences were most useful to assess the nature, severity, extension, and topographic pattern of lesions. Lesions were predominantly T2‐hyperintense and T1‐isointense with minimal or absent contrast enhancement.  相似文献   

A Bayesian meta-analysis of the effects of administering an intra-vaginal (CIDR) device in combination with other hormones on the reproductive performance of cycling,anoestrous and inseminated cows     

AR Rabiee  IJ Lean  MA Stevenson 《New Zealand veterinary journal》2013,61(6):384-393

AIMS: To evaluate the effectiveness of treatment programmes that included controlled internal drug-releasing (CIDR) devices containing progesterone (P4) in improving synchrony of oe- strus, and conception and pregnancy rates in cycling, anoestrous and inseminated dairy cows, using meta-analysis. To describe the difference in response between cycling and anoestrous cows to CIDR-based synchrony programmes.

METHODS: Scientific papers written in the English language between 1989 and 2002 that investigated the effects of treat- ment programmes including CIDR devices on reproductive per- formance in dairy heifers or lactating dairy cows were identified using a computerised literature search. The criteria for inclusion incorporated evidence that treatment allocation was completely randomised; the population studied was lactating dairy cows; and that data were available on submission, conception and pregnancy rates and their associated measures of variability. Re- productive outcomes from 25 synchrony trials (total n= 11,058 cows) were analysed. Summary measures of the effect of treat- ment on reproductive outcome were assessed using fixed- and random-effects Bayesian meta-analysis models.

RESULTS: Treatment programmes including a CIDR device increased the risk of submission in cycling cows (predicted Bayesian RR=2.86, 95% credible interval 1.46–5.67). Compared with controls, synchrony programmes including CIDR devices in cycling dairy cows had no effect on the risk of conception to first service post-treatment (predicted Bayesian RR=1.00, 95% credible interval=0.80-1.24). Compared with controls, synchrony programmes including CIDR devices had no effect on the risk of pregnancy throughout the mating period (pre- dicted Bayesian RR=1.02, 95% credible interval=0.89-1.17). In anoestrous cows, CIDR treatment had no effect on the risk of conception to first service post-treatment and no effect on the risk of pregnancy throughout the mating period, compared with anoestrous, untreated controls (predicted Bayesian RR=0.91 and 0.97, respectively; 95% credible interval=0.68–1.26 and 0.59-1.60, respectively).

CONCLUSION: The results of this meta-analysis showed that synchrony programmes using CIDR devices combined with other hormones reliably enhanced submission rates in lactat- ing dairy cows. The relatively small number of trials with data suitable for analysis and the heterogeneity of results at the indi- vidual trial level limited our ability to confirm either a beneficial or deleterious effect of treatment on conception or pregnancy rates. Further randomised, controlled trials to evaluate the ef- fectiveness of this form of reproductive therapy in commercial dairy farms are needed.  相似文献   

Blood sampling for inorganic phosphate analysis     

Bronwyn Smith  A. J. Fraser  P. J. O'Hara B.V.Sc. Ph.D. 《New Zealand veterinary journal》2013,61(9):190-192

Extract

It has been the, policy of this laboratory to request that blood samples for inorganic phosphate analysis be collected in potassium oxalatesodium fluoride anticoagulant but the origin of this recommendation is obscure. The recommendation is presumed to be based on the premise that fluoride ion inhibits a wide range of enzymes that hydrolyse phosphate esters and release phosphate ions.  相似文献   

Septic osteitis of the axial border of the proximal sesamoid bones in two foals     

C. P. Lawrence  B. S. L. Fraser 《Equine Veterinary Education》2013,25(2):63-66

This case report describes the history, clinical findings, clinical pathology and diagnostic imaging of 2 cases of septic osteitis of the proximal sesamoid bones in foals. Treatment with doxycycline (10 mg/kg bwt per os b.i.d.) was successful in treating both of these cases.  相似文献