Estimation of heritability for superficial digital flexor tendon injury by Gibbs sampling in the Thoroughbred racehorse

The superficial digital flexor tendon (SDFT) injury causes considerable wastage of racing Thoroughbreds. In this study, the heritability of SDFT injury of the forelimbs was estimated in the Thoroughbred racehorses based on the Bayesian analysis with Gibbs sampling using threshold animal models. New horse patients of SDFT injury at the age of 2–5 years accommodated in the training centers in 2005 were used for the analyses. Based on clinical data of 8198 horses, heritability of SDFT was estimated to be the order of 0.17 (posterior mode) to 0.19 ± 0.05 (posterior mean ± posterior SD).     

Cardiac output and other hemodynamic variables in anesthetized dogs undergoing laparotomy because of abdominal neoplasia

OBJECTIVE: To measure cardiac output and other hemodynamic variables in anesthetized dogs undergoing laparotomy because of abdominal neoplasia. DESIGN: Prospective case series. ANIMALS: 8 dogs with splenic or hepatic tumors. PROCEDURES: Dogs were anesthetized and underwent abdominal laparotomy. End-tidal isoflurane concentration, heart rate, arterial blood pressures, cardiac output, arterial pH, blood gas partial pressures, PCV, and plasma total protein concentration were measured at set intervals before, during, and after surgery. Cardiac index, stroke index, and systemic vascular resistance index were calculated. RESULTS: End-tidal isoflurane concentration was lowest before and after surgery. Heart rate did not change significantly throughout the anesthetic period. Arterial blood pressures and systemic vascular resistance index were highest shortly after surgery began; cardiac index and stroke volume index did not change significantly during surgery but increased significantly after surgery ended. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that in dogs undergoing laparotomy because of abdominal neoplasia, changes in arterial blood pressures were not necessarily indicative of qualitatively similar changes in cardiac index.     

Anticholinergic effects of artemisinin, an antimalarial drug, in isolated guinea pig heart preparations

Concern has been growing about the cardiac toxicity of antimalarial drugs. Artemisinin, a unique type of antimalarial drug originating from a Chinese medicinal plant, has minimal adverse effects, but it has been reported to inhibit delayed rectifier potassium current, a voltage-gated potassium current. However, no studies have been published concerning the effect of artemisinin on ligand-gated potassium currents. Therefore, in the present study, we examined the influence of artemisinin on the acetylcholine receptor-operated potassium current (IK.ACh), a ligand-gated potassium current, in guinea pig atrial myocytes using a patch clamp technique. Artemisinin (1 to 300 microM) inhibited I(K.ACh) induced by extracellular application of both carbachol (1 microM) and adenosine (10 microM) and that induced by intracellular loading of GTPgammaS (100 microM) in a concentration-dependent manner. Artemisinin inhibited carbachol-induced, adenosine-induced, and GTPgammaS-activated IK.ACh within almost the same concentration range. In left atria, artemisinin (1 to 100 microM) partially reversed the shortening of action potential duration induced by carbachol in a concentration-dependent manner. Carbachol-induced negative inotropic action in left atria was also inhibited by artemisinin (10 to 300 microM). In conclusion, we suggest that the anticholinergic action of artemisinin is mediated through inhibition of IK.ACh via inhibition of the muscarinic potassium channel and/or associated GTP-binding proteins.     

Epidural spinal myelolipoma in a dog

Epidural spinal myelolipoma was diagnosed in a 13-year-old, male Siberian husky that was referred for evaluation of progressive pelvic limb paresis and urinary incontinence. An epidural mass was detected by magnetic resonance imaging and computed tomography. The mass was removed and identified histopathologically as an epidural myelolipoma. Pelvic limb paresis improved after surgery, but urinary retention associated with neurological bladder dysfunction persisted.     

Human CHN1 mutations hyperactivate alpha2-chimaerin and cause Duane's retraction syndrome

Duane's retraction syndrome (DRS) is a complex congenital eye movement disorder caused by aberrant innervation of the extraocular muscles by axons of brainstem motor neurons. Studying families with a variant form of the disorder (DURS2-DRS), we have identified causative heterozygous missense mutations in CHN1, a gene on chromosome 2q31 that encodes alpha2-chimaerin, a Rac guanosine triphosphatase-activating protein (RacGAP) signaling protein previously implicated in the pathfinding of corticospinal axons in mice. We found that these are gain-of-function mutations that increase alpha2-chimaerin RacGAP activity in vitro. Several of the mutations appeared to enhance alpha2-chimaerin translocation to the cell membrane or enhance its ability to self-associate. Expression of mutant alpha2-chimaerin constructs in chick embryos resulted in failure of oculomotor axons to innervate their target extraocular muscles. We conclude that alpha2-chimaerin has a critical developmental function in ocular motor axon pathfinding.     

Successful outcome after a single endoscopic fecal microbiota transplantation in a Shiba dog with non-responsive enteropathy during the treatment with chlorambucil

A 7-year 6-month-old, castrated male Shiba dog presented with a 1-month history of lethargy, anorexia, vomiting, and frequent watery diarrhea. Weight loss, hypoalbuminemia, anemia, and leukocytosis were detected at the first visit. The dog was diagnosed with non-responsive enteropathy (NRE) based on clinical and histopathological examinations. Since the dog did not respond to the immunosuppressive drugs, fecal microbiota transplantation (FMT) was performed during the treatment with chlorambucil. A single endoscopic FMT into the cecum and colon drastically recovered clinical signs and clinicopathological abnormalities and corrected dysbiosis in the dog. No recurrence or adverse events were observed. The present case report suggests that FMT, possibly together with chlorambucil, might be a treatment option for NRE in Shiba dogs that have poorer prognosis compared with other dog breeds.     

Improved control of black rot of broccoli caused by <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis> using a bacteriophage and a nonpathogenic <Emphasis Type="Italic">Xanthomonas</Emphasis> sp. strain

We examined the potential for biological control of black rot of broccoli, caused by Xanthomonas campestris pv. campestris (Xcc), using nonpathogenic Xanthomonas sp. strain 11-100-01 (npX) mixed with bacteriophage XcpSFC211 (pXS). Inoculation of intact broccoli plants in greenhouse trials with either npX or pXS did not control black rot. After injured plant inoculation, however, npX alone or npX with pXS significantly controlled black rot. When a mixed suspension of npX with pXS was placed on a membrane filter, then washed with distilled water and air-dried, a substantial amount of pXS adsorbed to the surface of npX. In a field trial, broccoli plants were sprayed with a suspension of npX with pXS, then inoculated with Xcc. A meta-analysis of the results from five field trials showed an integrated risk ratio (IRR, the ratio of disease incidence in inoculated broccoli plants to the incidence in control plants) of 0.69 after treatment with only npX and 0.59 with npX with pXS, indicating that black rot incidence was significantly reduced by each treatment. The difference between these two treatments was also significant. IRR was 1.24 when comparing suppression by npX with pXS and that by basic copper sulfate wettable powder; thus, their control was comparable. The combination of npX with pXS improved the preventive effect against black rot. This is the first report describing that a nonpathogenic Xanthomonas sp. strain mixed with a bacteriophage effectively controlled black rot of broccoli in field trials.     

Efficacy of phosphonate in controlling white powdery rot of fig caused by <Emphasis Type="Italic">Phytophthora palmivora</Emphasis>

Pre- and post-infection activities of phosphonate and fungicides (azoxystrobin, chlorothalonil, cyazofamid, copper hydroxide, and copper sulfate) against white powdery rot on fig leaves caused by Phytophthora palmivora were determined. Phosphonate and fungicides were applied at 3, 7, or 14 days before inoculation and 16, 24, or 40 h after inoculation. Phosphonate and four fungicides (except for chlorothalonil) had protectant activity for up to 14 days before inoculation. Protectant activity between phosphonate and the four fungicides did not differ significantly. These fungicides did not have a curative activity, whereas only phosphonate had a curative activity when applied 16 h after inoculation. The pre-infection activity of phosphonate was determined in fig fields. Phosphonate provided excellent protectant activity, and its activity did not differ significantly from that of the copper fungicides. The activity of phosphonate in the life cycle of P. palmivora was compared with that of the five fungicides. Half-maximal effective concentration of the inhibition of mycelial growth was low for phosphonate, chlorothalonil, and the two copper fungicides. Mycelial growth was least affected by azoxystrobin and cyazofamid, but n-propyl gallate, an alternative oxidase inhibitor, in combination with these fungicides, significantly inhibited mycelial growth. Sporangium formation was sensitive to all compounds. Germination of encysted zoospores was sensitive to azoxystrobin, cyazofamid, and chlorothalonil and least sensitive to phosphonate and the two copper fungicides. The activity of phosphonate on mycelial growth and sporulation of P. palmivora suggests it has potential for controlling the disease.     

Anatomy and lignin distribution of reaction wood in two Magnolia species

Summary Anatomical features of reaction wood formed in two Magnolia species, M. obovata Thunb. and M. kobus DC. which are considered to be among the primitive angiosperms, were observed. In addition, the distribution of guaiacyl and syringyl units of lignins in the cell walls of normal and reaction wood was examined using ultraviolet (UV)- and visible light (VL)- microspectrophotometry coupled with the Wiesner and M?ule reactions. The two Magnolia species formed a tension-like reaction wood without possessing the typical gelatinous layer (G-layer) on the upper side of the inclined stem or branch, in which a radial growth promotion occurred. Compared with the normal wood, the reaction wood had the following anatomical features: (1) the secondary walls of fiber tracheids lacked the S₃ layer, (2) the innermost layer of fiber-tracheid walls showed a small microfibril angle, a fact being similar to the orientation of the microfibril angle of the G-layer in tension wood, and (3) the amounts of lignin decreased in the cell walls of fiber tracheids, especially with great decrease in proportion of guaiacyl units in lignins. In addition, VL-microspectrophotometry coupled with the Wiesner and M?ule reactions adopted in the present study showed potential to estimate the lignin contents in the cell walls and the proportion of guaiacyl and syringyl units in lignins. Received: 15 July 1998     

Formation of malonaldehyde and acetaldehyde from the oxidation of 2'-deoxyribonucleosides.

2'-Deoxyribonucleosides, ribonucleosides, nucleobases, deoxyribose, and ribose were oxidized with Fenton's reagent. Malonaldehyde (MA) formed was derivatized with N-methylhydrazine to N-methylpyrazole, and acetaldehyde formed was derivatized with cysteamine to 2-methylthiazolidine. The resulting nitrogen-containing derivatives were quantitatively analyzed using gas chromatography with a nitrogen-phosphorus detector. MA and acetaldehyde were found in 2-deoxy-D-ribose and 2'-deoxyribonucleosides but not in ribonucleosides, nucleobases, and D-ribose. Amounts of MA formed from four deoxynucleosides were in the following order: 2'-deoxyguanosine > 2'-deoxycytidine > 2'-deoxyadenosine > or = thymidine. Amounts of acetaldehyde formed from four deoxynucleosides were in the following order: 2'-deoxycytidine > thymidine > 2'-deoxyadenosine > or = 2'-deoxyguanosine. The results suggest that the formation of MA and acetaldehyde requires a deoxy group on carbon 2' of a ribose moiety.