Use of an extracorporeal circuit to evaluate effects of intraluminal distention and decompression on the equine jejunum

OBJECTIVE: To use an extracorporeal circuit to evaluate effects of intraluminal distention on the jejunum of healthy horses. SAMPLE POPULATION: 2 jejunal segments from each of 5 horses. PROCEDURE: Jejunal segments were harvested and maintained in an extracorporeal circuit. One segment was subjected to distention (intraluminal pressure, 25 cm H2O) followed by decompression, and 1 segment was maintained without distention. The influence of distention-decompression on vascular resistance was calculated. Mucosal permeability was evaluated by measuring the clearance of albumin from blood to lumen. After distention and decompression, tissue specimens were collected for histomorphologic evaluation. In addition, the contractile response of the circular smooth muscle layer was determined following incubation with 3 prokinetic agents. RESULTS: Intestinal vascular resistance increased during intraluminal distention and returned to baseline values after decompression. Albumin clearance rate increased after distention, compared with baseline and control values. Histologic examination of the distended segments revealed grade-1 and -2 lesions of the mucosal villus. Edema and hemorrhage were evident in the submucosa and muscular layers. Mesothelial cell loss, edema, and hemorrhage were also evident in the serosa. Mucosal surface area and villus tip height decreased and submucosal volume increased in the distended tissue. Compared with responses in control specimens, distention decreased the contractile response induced by cisapride, erythromycin, and metoclopramide. CONCLUSIONS AND CLINICAL RELEVANCE: Intraluminal distention of the jejunum followed by decompression increased mucosal permeability and injury and decreased responses to prokinetic agents. Horses with intraluminal intestinal distention may have a decreased response to prokinetic agents.     

In vitro investigation of the effects of cyclooxygenase-2 inhibitors on contractile activity of the equine dorsal and ventral colon

OBJECTIVE: To evaluate the effect of 2 cyclooxygenase (COX)-2 inhibitors on contractile activity of the circular smooth muscle layer of the equine dorsal and ventral colon. SAMPLE POPULATION: Samples of the dorsal and ventral colon obtained from 10 healthy horses. PROCEDURE: Full-thickness tissue samples were collected from the dorsal colon in the area of the diaphragmatic flexure and the ventral colon in the area of the sternal flexure. Samples were cut into strips oriented along the fibers of the circular muscle layer and mounted in a tissue bath system for determination of contractile strength. Incremental amounts of etodolac, nabumetone, and indomethacin were added, and contractile activity was recorded. RESULTS: Response of the dorsal and ventral colon to nonsteroidal anti-inflammatory drugs (NSAIDs) was variable. Indomethacin induced the greatest reduction in contractile activity, followed by nabumetone. For etodolac, the difference from baseline values was only significantly reduced at the highest concentration used (1 X 10(5)M) for the ventral colon. CONCLUSIONS AND CLINICAL RELEVANCE: The NSAIDs that are designed to target the COX-2 isoform appeared to have variable effects on the contractile activity of the equine dorsal and ventral colon. Etodolac appeared to have the least effect on contractile activity, compared with the effects attributable to nabumetone, and would potentially have the fewest adverse effects relative to motility of the dorsal and ventral colon.     

通过种间杂交选育加工黄瓜新品种宁佳1号

以黄瓜属(Cucumis)野生种(C. hystrixChakr. )为母本,以栽培黄瓜(C. sativusL. )北京截头为父本,通过远缘杂交导入外源种质,结合多代回交、自交获得黄瓜新种质7012A。将7012A与美国威斯康辛大学选育的雌性系黄瓜(7011A)杂交获得F1,与亲本及美国推广加工黄瓜品种进行品种比较试验,结果表明:F1 具有超亲优势,结瓜整齐,营养价值高,加工品质良好。植株长势强,主侧蔓均有结瓜能力,主蔓结瓜为主,后期产量高。     

Organophosphorothioates and synergised synthetic pyrethroids as grain protectants on bulk wheat

Organophosphorothioates and synergised synthetic pyrethroids were used in duplicate field trials carried out on bulk wheat in commercial silos in Queensland and New South Wales. Laboratory bioassays using malathion-resistant strains of insects were carried out on samples of treated grain at intervals over 9 months. These established that all treatments were generally effective. Deltamethrin (2 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1), fenitrothion (12 mg kg^?1)+ fenvalerate (1 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1), fenitrothion (12 mg kg^?1)+ phenothrin (2 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1) and pirimiphos-methyl (4 mg kg^?1)+ permethrin (1 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1) controlled common field strains of Sitophilus oryzae (L.) and Rhyzopertha dominica (F.). Against a highly resistant strain of S. oryzae, deltamethrin (2 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1) was superior to the remaining treatments. All treatment combinations completely prevented progeny production in Tribolium castaneum (Herbst), T. confusum Jacquelin du Val and in Ephestia cautella (Walker). Residues of deltamethrin, fenvalerate, permethrin and phenothrin were determined and shown to be highly persistent on stored wheat. During milling, residues accumulated in the bran fractions and were reduced in white flour. They were not significantly reduced during baking.     

Detection and spread of Phytophthora austrocedri within infected Juniperus communis woodland and diversity of co‐associated Phytophthoras as revealed by metabarcoding

Phytophthora austrocedri is a recently invasive soilborne pathogen which is causing widespread mortality of Juniperus communis in northern Britain. The pathways by which a single genotype of P. austrocedri has spread to infect such a geographically dispersed range of woodland sites within a relatively short timeframe are unknown. This study examined the detectability of P. austrocedri in soil and water within infected J. communis woodland using qPCR to gain a better understanding of the pathogen's key mechanisms of spread. A Phytophthora metabarcoding method was also applied to investigate the wider diversity of Phytophthora species present in water at one of the sites. qPCR analyses of P. austrocedri in soil samples at a J. communis woodland exhibiting low‐to‐moderate levels of disease suggested a slow natural spread of the pathogen in soil, requiring high moisture conditions. However, the ubiquity of P. austrocedri DNA in soil samples collected across a heavily infected J. communis site suggests that once established at a site the pathogen can be spread readily in soil locally, most likely vectored by animal movements and/or human activities. The hypothesis that P. austrocedri is aerially transmitted in rainwater was not adequately proven, and an alternative hypothesis for the widespread distribution of the pathogen on J. communis in northern Britain is presented. Metabarcoding identified DNA from a diverse range of Phytophthora species in river and rainwater samples although the main target pathogen, P. austrocedri, was not amplified which disagreed with some of the qPCR findings. Possible reasons for this are discussed.     

The efficacy of systemically administered anti-arthritic drugs in an induced equine carpitis model

The efficacy of two systemically administered drugs for the treatment of equine joint injuries was assessed in a randomized blinded trial using the chemically induced equine carpitis model previously used to determine the dose and efficacy of both products. After a 10-day acclimation period, carpitis was induced by intracarpal injection of Complete Freund's Adjuvant (CFA) in twenty mature horses free of clinical and radiographic evidence of synovitis or DJD. Five days after model induction, the horses were stratified based on lameness evaluation and randomly assigned to 2 groups of 10 horses each.Parameters evaluated included lameness score, maximum range of carpal flexion, carpal circumference, stride length, and synovial fluid protein. These parameters were measured prior to model induction, 5 days after model induction (immediately prior to initial treatment) and once weekly for 6 weeks. Radiographs of the carpus were taken prior to model induction and 6 weeks. after treatment began. Treatment began 5 days after model induction. One group of 10 horses received 40 mg sodium hyaluronate by intravenous injection weekly for 3 weeks and the other group of 10 horses received intramuscular injections of 500 mg PSGAG every 4 days for 7 treatments.Both treatment groups showed significant improvement from pretreatment baseline values (based upon percent recovery to normal pre-model induction values) for lameness score, stride length and maximum carpal flexion (p<0.05) at each post treatment evaluation. The PSGAG treated group had significant improvement in synovial fluid protein at post treatment weeks 2 and 3. The improvement (percent recovery) in the PSGAG treated group was significantly (p<0.05) better than that of the intravenous sodium hyaluronate treated group for stride and flexion at post treatment weeks 1 through 6, for lameness score at post treatment weeks 1 through 3 and for carpal circumference at post treatment week 4.Both intravenous sodium hyaluronate and intramuscular PSGAG induced significant improvement in clinical lameness parameters; intramuscular PSGAG yielded consistently better results in this experimental model.     

西南地区的干热河谷及其森林培育(英文)

干热河谷主要分布于长江、珠江、澜沧江、红河和怒江等国内和国际性河流的上游深切 河谷地段。本文对干热河谷形成的地理和气候原因进行了阐述，并通过引证大量文献，分析 了干热河谷植被的历史情况和现状。由于干热河谷地区的地质结构不稳定、土层浅薄、人口 膨胀、过度耕种，尤其长达半年的旱季等原因，导致该地区的生态环境处于极端的脆弱阶段 。当地的原始植被为常绿阔叶林和落叶阔叶林，但均遭到严重的破坏。现有植被为次生的稀 树草坡和肉质化刺灌木。由于干热河谷的植被情况直接影响河流水体的质量，因此河谷内的 植被恢复和水土保持就成为流域治理的最重要的任务。目前已经开展了一系列的有关造林技 术的前期研究项目，但大规模的造林培育工程尚难以开展。