红麻种质资源遗传多样性和分子鉴定技术研究I．红麻AFLP—银染技术和种质资源指纹图谱的构建

通过摸索和优化实验条件，建立了红麻的AFLP—银染实验体系，获得了清晰的红麻种质资源AFLP指纹图谱。通常不同品种的红麻种质资源在形态特征上差异很小，但AFLP—银染技术检测到不同来源和不同品种的在红麻种质资源中存在较大的遗传差异。这一技术对红麻种质资源的鉴定和遗传多样性的检测非常有效。     

Oronasal blastomycosis in a golden retriever

Blastomycosis is one of the most common systemic fungal infections in dogs in North America Pulmonary manifestations are most common; localized disease is rare. A case of localized oronasal blastomycosis mimicking oral neoplasia is described. Long-term therapy with itraconazole resulted in clinical cure.     

Retrospective study of 108 foals with septic osteomyelitis

Objective   To determine the clinical characteristics, short-term outcome and future athletic performance of foals with septic osteomyelitis.
Design   Retrospective clinical study of 108 Thoroughbred foals with radiographic evidence of bone infection that were presented at the Scone Veterinary Hospital between August 1995 and December 2001. Medical records were reviewed and information concerning signalment, the clinical, laboratory and radiographic findings, treatment and outcome was obtained. Racing records were obtained and evaluated for surviving foals that had reached racing age.
Results   Mean age of foals at initial evaluation was 39 days (range 1–180 days); 21 foals had multiple radiographic bone lesions (19.4%), and 76 had concurrent septic arthritis (70.4%). The most frequently affected bones were the femur, tibia and distal phalanx. In total, 87 foals were discharged from the hospital (80.6%), 79 survived long-term to reach racing age and 52 raced (65.8%). Overall, 48% (52/108) of the foals treated for osteomyelitis raced. Foals less than 30 days of age at the time of diagnosis, critically ill foals and those with multiple bones or joints affected were significantly less likely to be discharged from hospital. Multiple septic joints, but not multiple bone involvement, had an unfavourable prognosis for racing.
Conclusions   The prognosis for survival of foals with septic osteomyelitis or osteitis is favourable. Multiple bone or joint involvement is an important short-term prognostic indicator; however, the involvement of multiple joints, but not multiple infected bones, is associated with an unfavourable prognosis for racing.     

Chemical and mineral control of soil carbon turnover in abandoned tropical pastures

We investigated changes in soil carbon (C) cycling with reforestation across a long-term, replicated chronosequence of tropical secondary forests regrowing on abandoned pastures. We applied CP MAS ¹³C NMR spectroscopy and radiocarbon modeling to soil density fractions from the top 10 cm to track changes in C chemistry and turnover during secondary forest establishment on former pastures. Our results showed that inter-aggregate, unattached, particulate organic C (free light fraction) and particulate C located inside soil aggregates (occluded light fraction) represent distinct soil C pools with different chemical composition and turnover rates. The signal intensity of the O-alkyl region, primarily representing carbohydrates, decreased, and alkyl C, attributed to recalcitrant waxy compounds and microbially resynthesized lipids, increased from plant litter to soil organic matter and with incorporation into soil aggregates. The alkyl/O-alkyl ratio, a common index of humification, was higher in the occluded than in the free light fraction. Greater variability in the chemical makeup of the occluded light fraction suggests that it represents material in varied stages of decomposition. Mean residence times (¹⁴C-based) of the free light fraction were significantly shorter (4 ± 1 years) than for the heavy fraction. We report two scenarios for the occluded light fraction, one fast-cycling in which the occluded and free light fractions have similar turnover rates, and one slow-cycling, in which the occluded light fraction resembles the heavy fraction. Mean residence times of the occluded light fraction and heavy fraction in active pastures and 10-year old secondary forests in the earliest stage of succession were longer than in older secondary forests and primary forests. This is likely due to a preferential loss of physically unprotected C of more labile composition in the pastures and in the youngest successional forests, resulting in an increase in the dominance of slow-cycling C pools. Soil carbon turnover rates of the mineral-associated C in secondary forests recovering from abandoned pasture resembled those of primary forests in as little as 20 years of succession.     

Pneumonia after intracranial surgery in dogs

OBJECTIVE: To determine factors associated with the occurrence of pneumonia after intracranial surgery in dogs. STUDY DESIGN: Retrospective cohort study. Animals-Forty-nine client-owned dogs. METHODS: The medical records of 49 dogs with space-occupying intracranial disease that underwent craniotomy were reviewed. Development of pneumonia after surgery was considered highly likely in 12 dogs (affected dogs) based on clinical signs, including acute dyspnea or coughing in association with typical radiographic findings or abnormal transtracheal wash results. Pneumonia was confirmed in 6 dogs based on necropsy findings. Affected dogs were compared with 37 dogs that did not develop pneumonia (unaffected dogs) subsequent to intracranial surgery. Based on the medical records of affected dogs, determinations were made regarding time between development of pneumonia and surgery, surgical procedure, intracranial lesion type, and intracranial lesion location. Risk factors examined for both affected and unaffected dogs included level of consciousness, body position during the postoperative recovery period, duration of anesthesia, occurrence of vomiting or regurgitation, presence of seizures, cranial nerve deficiencies, and the presence of megaesophagus before and after surgery. We also compared the feeding protocol after surgery for each group. RESULTS: Pneumonia typically occurred within the first week after surgery (median, 6.5 days); however, this was variable (range, 1-96 days). Of the factors that were present within 24 hours before the clinical signs of pneumonia, vomiting or regurgitation and megaesophagus were found to be significant risk factors. Dogs that vomited or regurgitated were 2.71 times more likely to develop pneumonia than dogs that did not. Vomiting or regurgitation occurred in 63% of the dogs that developed pneumonia in this cohort. Dogs with megaesophagus were 9.25 times more likely to develop pneumonia than dogs without megaesophagus. Seven dogs with pneumonia died. Five of these 7 dogs appeared to have died as a direct sequel to pneumonia. CONCLUSION: Dogs undergoing craniectomies for space-occupying intracranial disease may be at higher risk for development of pneumonia due to several factors, including vomiting, regurgitation, and megaesophagus.     

Effects of changes in power setting of an ultrasonic aspirator on amount of damage to the cerebral cortex of healthy dogs

OBJECTIVE: To determine the minimal ultrasonic aspirator pressure necessary to damage the cerebral cortex of healthy dogs. ANIMALS: 9 mixed-breed dogs. PROCEDURE: The study comprised 2 parts. In part A, 6 dogs were euthanatized immediately prior to the experiment. In part B, 3 dogs were anesthetized for recording of physiologic variables. In both parts, craniectomy and durotomy were performed to bilaterally expose the lateral aspect of the cerebral cortex. An ultrasonic aspirator was placed in contact with various areas of the cerebral cortex, and aspirator power was altered (10, 20, 30, and 40%). Duration of contact at each power was 5 and 10 seconds. Subsequently, gross morphologic and histologic damage was assessed in the cortex. RESULTS: Gross observations for all dogs were similar. At 10% power, visible or histologic damage was not evident in the cortex. At 20% power, the cortex was slightly indented from contact with the hand piece; however, cortical disruption was not evident. Cortical disruption was initially detectable at 30% power in some dogs and was consistently evident at 40% power in both sets of dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonic aspirator power of < 20% created minimal acute morphologic damage to the cortex. Power settings between 20 and 30% may superficially damage the cerebral cortex in healthy dogs, whereas 40% power consistently damages the cerebral cortex. Knowledge of the degree of damage to cerebral cortex caused by various amounts of power for ultrasonic aspirators will allow surgeons to avoid damaging normal brain tissues during surgery.     

Infertility in a Dog due to Proximal Cytoplasmic Droplets in the Ejaculate: Investigation of the Significance for Sperm Functionality In Vitro

A 4-year-old Basque Shepherd male dog was presented for breeding soundness evaluation after the dog failed to impregnate the three bitches he had mated. Clinical examination showed no anomaly of the reproductive system. Semen evaluation showed normal sperm count (640 x 10(6)), 80% had progressively motile spermatozoa, and 96% had morphologically abnormal sperm of which 84% had proximal cytoplasmic droplet and 12% had proximal droplet plus other anomaly. A zona pellucida-binding assay, using canine oocytes derived from frozen-thawed ovaries, was performed in order to investigate the zona-binding ability of dog spermatozoa with proximal cytoplasmic droplets. For the zona pellucida-binding assay, ovaries were thawed and minced in phosphate-buffered saline + 0.4% bovine serum albumin, the oocytes recovered were divided into two groups of 35-40 oocytes to be, respectively, used with the infertile dog and with a control fertile dog. Spermatozoa were capacitated in Canine Capacitating Medium (CCM) at 38.5 degrees C and 5% CO(2) in air for 2 h before oocyte insemination. Groups of five to six oocytes placed in 45 microl droplets of CCM were incubated for 1 h. Afterwards, 5 microl of CCM containing 25,000 spermatozoa were added to each droplet and co-incubated for 2 h before fixation and evaluation of the complexes. After oocyte insemination, sperm motility and viability were evaluated: the sample from the infertile dog had 85% sperm motility with fast and linear progressive movement, and sperm viability of 92%. The sample from the control dog showed 40% sperm motility with fast and highly curvilinear and erratic movement, high degree of sperm agglutination and sperm viability of 32%. For the infertile dog the mean number of bound spermatozoa/oocyte was 0.33 whereas for the control dog it was 1.80. It was concluded that dog sperm with proximal cytoplasmic droplets seem to lack normal capacitating ability in vitro, and consequently, they may have reduced capacity to bind to the zona pellucida of canine oocytes.