PubMed · 4801909
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
S A Koch. 1973. Ulcerative keratitis.. https://doi.org/10.1016/s0091-0279(73)50056-x
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Four trials were conducted in which laboratory-reared Dermacentor variabilis nymphs were exposed to Ehrlichia canis by feeding on experimentally infected dogs as soon as classical morulae were detected in peripheral blood monocytes. After molting 25, 50 or 90 adult tick pairs were permitted to feed on 7 Ehrlichia-naive dogs. Transmission occurred in trials 1 (1/1 dog), 3 (1/1 dog) and 4 (2/2 dogs) but not in trial 2 (0/3 dogs), with 4 of 7 dogs becoming infected. Successful transstadial transmission was demonstrated by detection of morulae in peripheral blood lymphocytes and by seroconversion to Ehrlichia canis 30 d post-exposure. Incubation periods ranged between 17 and 22 days (mean = 19). Clinical signs, typical of ehrlichiosis, included mucopurulent ocular discharge, lymphadenopathy and malaise with accompanying pyrexia, leukopenia and thrombocytopenia. Pyrexia, thrombocytopenia and erythrophagocytosis and vacuolization of the cytoplasm of monocytic cells were observed 1-4 d prior to detection of morulae. This is the first demonstration that a tick other than Rhipicephalus sanguineus is capable of transstadial transmission of this important pathogen of dogs.
The effects of intravenous administration of variable-dose midazolam (0, 0.05, 0.075, 0.1, 0.3 and 0.5 mg/kg) and ketamine (3 mg/kg) were studied in twenty-four healthy unmedicated cats from time of administration until full recovery. End-points were chosen to determine the optimal dose to allow a short period of restraint without noxious stimuli, a short period of restraint with noxious stimuli and endotracheal intubation. Recovery characteristics, as well as undesirable behaviours observed during recovery, were also recorded. The dose of midazolam to achieve lateral recumbency with head down was found to be 0.016 mg/kg in 50% of the population (ED50) and 0.054 mg/kg in 95% (ED95) of the population. A midazolam dose of 0.286 mg/kg was required to prevent conscious perception of a stimulus to the ulnar nerve in 50% of the population and 0.652 mg/kg in 95% of the population. The ED50 and ED95 of midazolam required to prevent swallowing in response to a laryngoscope placed on the back of the tongue were found to be 0.265 mg/kg and 0.583 mg/kg, respectively. The ED50 doses of 0.265 mg/kg for intubation and 0.286 mg/kg for restraint with noxious stimulation were close to the tested dose of 0.3 mg/kg. At that dose, the lack of responses lasted 3.67 +/- 2.27 min for laryngoscope and 2.50 +/- 2.20 min for ulnar nerve stimulation, with recovery to walking with ataxia taking 41.50 +/- 15.18 min and complete recovery taking 3.6 +/- 1.3 h. The predominant behavioural pattern during recovery was found to be normal, but some cats also exhibited abnormal behavioural patterns. Nine of the twelve cats exhibited an abnormal arousal state, with 4 being restless and 5 being sedated. Seven of the twelve cats exhibited an abnormal behaviour when approached, with three of the cats being more difficult to approach and four of the cats being easier to approach. Eight of the twelve cats exhibited an abnormal behavioural pattern when restrained, with the cats equally divided between more difficult and easier to restrain. Five of the twelve cats vocalized more during the recovery. The ED50 of 0.042 mg/kg to induce chemical restraint without a noxious stimulus is close to the tested dose of 0.05 mg/kg. At that dose, cats remained lateral with head down for 5.49 +/- 4.02 min, took 25.96 +/- 5.77 min to walk with ataxia and 1.7 +/- 0.4 h for complete recovery. The predominant behavioural patterns during recovery were normal, with several cats exhibiting some abnormal patterns. Two cats were sedated, one cat was more difficult to approach, one cat was easier to restrain and three cats were more vocal.
Many anaesthetics effect the latency and amplitude of somatosensory evoked potentials (SSEP). We present a patient who underwent two anterior/posterior spine fusions (A/PSF) at age 11 and 12 years old after resection of a spinal astrocytoma. She did have residual neurologic deficits of her lower extremities. SSEPs were unobtainable during the first surgery using an opioid-based anaesthetic. A ketamine-based anaesthetic was used for the second surgery and SSEPs were easily monitored. No other factors seem to have changed between the two surgeries. The anaesthetic management during each procedure is reviewed and the contributions of other factors to SSEP monitoring discussed.