Constant rate infusion of ketamine reduces minimal alveolar concentration of isoflurane in alpacas

Ketamine is a rapid acting, potent, nonspecific, noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist commonly used for inducing general anesthesia and for providing post-operative pain management and may possibly lessen the need for other potentially harmful or contraindicated analgesics in camelids, such as nonsteroidal anti-inflammatory drugs. Prior to determining the effectiveness of CRI ketamine for analgesia, a safe, sub-anesthetic dose was established that did not produce untoward side effects, sedation or alter normal behavior. Six healthy male alpacas (40–90 kg) were used for the trial and each acted as its own control. Each alpaca was randomly assigned to receive ketamine at 20 and 40 μg kg^–1 minute^–1 in 500 mL saline. A blinded observer recorded heart rate, respiratory rate, and body temperature hourly, and behavior for 8 hours. There was a 72-hour washout period between each dosing regime. An equal volume saline CRI without ketamine was used as a control. Each alpaca was allowed a one-week washout prior to being anesthetized with isoflurane using mask induction. After achieving a stable plane of anesthesia, the MAC value for isoflurane was determined. Ketamine was infused at 40 μg kg^–1pre-existing pain is unknown, but for elective procedures, preemptive analgesia using ketamine CRI in alpacas may be beneficial.     

Simultaneous Measurement of Local Gain and Electron Density in X-ray Lasers

X-ray lasers (XRLs) have experimental average gains that are significantly less than calculated values and a persistently low level of spatial coherence. An XRL has been used both as an injected signal to a short XRL amplifier and as an interferometer beam to measure two-dimensional local gain and density profiles of the XRL plasma with a resolution near 1 micrometer. The measured local gain is in agreement with atomic models but is unexpectedly spatially inhomogeneous. This inhomogeneity is responsible for the low level of spatial coherence observed and helps explain the disparity between observed and simulated gains.     

Measurement of Laser-Plasma Electron Density with a Soft X-ray Laser Deflectometer

A soft x-ray laser (wavelength lambda = 15.5 nanometers) was used to create a moiré deflectogram of a high-density, laser-produced plasma. The use of deflectometry at this short wavelength permits measurement of the density spatial profile in a long-scalelength (3 millimeters), high-density plasma. A peak density of 3.2 x 10(21) per cubic centimeter was recorded.     

Regional distribution and variation of gamma-globulin absorption from the small intestine of the neonatal calf

125I-labeled immunoglobulin (Ig)G1 in colostral whey was used to determine the region of maximum absorption of Ig from the small intestine of the neonatal calf and the variation in Ig absorption among calves at the intestinal level. In experiment 1, 5 segments (approx 5%, 35%, 60%, 80%, and 95% of the duodenocecal length) were formed in the small intestine of 9 colostrum-deprived calves shortly after birth. These segments were injected with colostral whey containing 125I-IgG1 4 hours after birth, and uptake, transfer, and absorption (defined as uptake plus transfer) were determined for each segment 2 hours later. Raw data were adjusted for the milligrams of IgG1 injected per gram of intestinal tissue to obtain the least squares mean (LSM) value. The LSM values for absorption of IgG1 from distal segments 3, 4, and 5 were significantly greater (P less than 0.05) than those values for proximal segments 1 and 2. The region of the maximum IgG1 absorption was the lower small intestine, 60% to 80% of the duodenocecal length. There was also an indication of independence between uptake and transfer in each of the segments. Significant differences (P less than 0.05) were present among calves in the LSM values for uptake and absorption, but not for transfer. In experiment 2, thoracic ducts of 8 newborn calves were cannulated 4 to 5 hours after birth. At 6 hours after birth, colostral whey with 125I-IgG1 was injected into an intestinal segment (approx 60% to 80% of the duodenocecal length).(ABSTRACT TRUNCATED AT 250 WORDS)     

RADIOGRAPHIC AND MYELOGRAPHIC EXAMINATION OF THE CERVICAL VERTEBRAL COLUMN IN 306 ATAXIC HORSES

This study consists of a review of 306 ataxic horses subjected to survey radiography and myelography of the cervical vertebral column. Fifty-eight percent of horses had evidence of compressive spinal cord lesion on myelography. Sixty-six percent of horses were less than 3 years old. Age had no effect on the distribution of spinal cord compressive lesions. No conclusion could be drawn from sex and breed distribution. The most common sites of cord compression on myelography in order of decreasing frequency were C_3–4, C_6–7, C_5–6, and C_4–5. Twenty-nine percent of horses with myelographic evidence of cord compression had multiple compressive sites. Survey radiographs were not reliable to diagnose compressive spinal cord lesions. Myelography was a safe and more accurate procedure. Several factors may result in misinterpretation of the myelographic examination.     

Movement of xylene through unsaturated soils following simulated spills

A field study was conducted to determine the rapidity and extent of xylene movement after simulated spills on undisturbed soils of diverse texture and structure. To monitor xylene movement, porous ceramic suction cups and newly developed pan samplers were installed at a depth of 61 cm at two locations in each of three soils. A volume equivalent to a depth of 5 cm of dye labeled xylene was spilled on one plot of each soil contained in large lysimeters. Split applications of 1.25 cm depth equivalent were also made 21 days apart on one lysimeter of each of the soils. Significant quantities of xylene were detected at the 61 cm depth approximately 1 day, 1 hr, and 0.5 hr after the 5 cm application in the loamy sand, silt loam, and clay, respectively. Xylene movement after the first 1.25 cm of the split xylene application was almost as rapid as after the 5 cm application. However, with the second 1.25 cm application of xylene, free xylene was collected in the leachate at the 61 cm depth for all three soils. Dye patterns observed upon excavation of the soils indicated that the xylene moved as a relatively uniform front in the sand but moved through isolated macropores between structural units in the silt loam and clay soils. The free drainage pan samplers were more effective than the porous ceramic suction samplers in monitoring the movement of xylene in all three soils at high soil moisture contents. The porous cup samplers were ineffective in the well structured clay soil, possibly due to being bypassed by the xylene moving through isolated macropores. Xylene concentrations from the porous cup samplers were often lower than those from the pan samplers. The lower concentrations are thought to be partially due to losses of xylene by volatilization when a vacuum was applied to collect the samples. Author for all correspondence.     

Gastroesophageal intussusception in a Labrador retriever.

A 14-month-old, intact male Labrador retriever was referred for evaluation of vomiting and regurgitation. A diagnosis of gastroesophageal intussusception with aspiration pneumonia was made. The patient responded favorably to aggressive surgical and medical management. The guarded to poor prognosis for gastroesophageal intussusception makes the successful outcome of this case unique.