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Thurmon JC, Neff-Davis C, Davis LE, Stoker RA, Benson GJ, Lock TF. Xylazine hydrochloride-induced hyperglycemia and hypoinsulinemia in thoroughbred horses. J Vet Pharmacol Ther 1982; 5:241-5. [PMID: 6763947 DOI: 10.1111/j.1365-2885.1982.tb00439.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The effects of intravenous xylazine (1.1 mg/kg) were studied in six thoroughbred horses (five mares and a stallion). Plasma glucose concentration increased to 168% of control at 45 min and decreased to 112% of control at 180 min. Insulin had decreased to 31% of control at 15 min. Thereafter, insulin concentration increased, reaching its highest concentration at 150 min. The mechanism for these changes is not fully understood and further investigation is indicated.
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228
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Alpha SR, Davis LE, Mann J. Botulism and the lack of protection by alcohol; experimental and epidemiological studies. JOURNAL OF STUDIES ON ALCOHOL 1982; 43:1263-1266. [PMID: 7182685 DOI: 10.15288/jsa.1982.43.1263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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229
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Nara PL, Davis LE, Lauerman LH, Coyle-Dennis JE, Paul J. Effects of chloramphenicol on the development of immune responses to canine distemper virus in beagle pups. J Vet Pharmacol Ther 1982; 5:177-85. [PMID: 7143554 DOI: 10.1111/j.1365-2885.1982.tb00428.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The effect of oral chloramphenicol (CHPC) on the development of immune responses to canine distemper virus (CDV) in Beagle pups was studied. Dogs were treated with CHPC for 14 days at a dose of 50 mg/kg, three times a day. Hematologic changes in CHPC-treated dogs included: polychromasia, anisocytosis, and target cell formation of red blood cells concurrent with vacuolation of lymphocytes and basophilic granule formation in neutrophils. Dogs given this therapy showed normal in vivo and in vitro immune responses after CDV vaccination and survived a virulent CDV challenge, whereas untreated, unvaccinated dogs became ill or died after challenge exposure. The results of this study indicate that CHPC therapy does not interfere with either the prechallenge immune response to attenuated viral antigen or the efficient immune mechanisms invoked during virulent virus challenge.
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230
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Woodfin BM, Davis LE. Altered OCTase location in the influenza B/Lee virus model for Reye's syndrome. BIOCHEMICAL MEDICINE 1982; 28:109-14. [PMID: 7150272 DOI: 10.1016/0006-2944(82)90060-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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231
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Abstract
Rational glucocorticoid therapy depends on a complicated interplay of many factors. An understanding of the physiology of the hypothalamic-pituitary-adrenal axis, the comparative potencies, duration, and adverse effects of the available corticosteroid bases and their esters, and especially the specific goals of the therapy for a wide variety of diseases facilitates this therapy. It is impossible to make specific dose recommendations for glucocorticoid therapy. Individual patients and their various diseases respond differently to a given dose of glucocorticoid.
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232
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Bretzlaff KN, Ott RS, Koritz GD, Lock TF, Bevill RF, Shawley RV, Gustafsson BK, Davis LE. Distribution of oxytetracycline in the genital tract of cows. Am J Vet Res 1982; 43:12-6. [PMID: 7091807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Pharmacokinetic parameters of the disposition of oxytetracycline (OTC) were investigated in healthy cycling dairy cows after a single IV dose of 22 mg/kg of body weight. The biological half-life of OTC was 6.5 hours. These data were used to predict an IV priming dose and a rate of constant IV infusion of OTC sufficient to approach steady-state equilibrium of the drug between a plasma concentration of approximately 5 microgram/ml and a uterine tissue concentration. After 8 hours' constant IV infusion, the mean plasma concentration of OTC was 4.86 +/- 0.68 microgram/ml and the mean uterine tissue concentration of OTC was 4.50 +/- 0.45 microgram/ml. The mean ratio of plasma-to-uterine tissue OTC concentrations was 1.08. Computer-stimulated IV multiple doses of OTC at 11 mg/kg every 12 hours and 11 mg/kg every 24 hours suggested that the former dosage regimen could provide uterine tissue concentrations greater than 5 microgram/ml during the dosage interval, whereas the latter could provide such concentrations for only the first 12 hours of a 24-hour dosage interval.
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233
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Davis LE. Experimental viral infections of the inner ear. III. Viremic spread of reovirus to hamster eighth nerve ganglion cells. Ann Otol Rhinol Laryngol 1982; 91:90-3. [PMID: 6280569 DOI: 10.1177/000348948209100120] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rubella, cytomegalovirus, mumps, and rubeola viruses cause deafness in man and are believed to reach the inner ear through viremic spread. Although several experimental studies of viral infection of the inner ear have been described, all require the virus inoculum to reach the labyrinth directly rather than through hematogenous spread. In this model, reovirus, type 3, infected the cell bodies of cochlear and vestibular ganglia of infant hamsters following a viremia induced by intraperitoneal inoculation. This model provides the first experimental evidence for viremic spread to the inner ear.
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234
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Hoffman RE, Zack MM, Davis LE, Burchfiel CM. Increased incidence and prevalence of multiple sclerosis in Los Alamos County, New Mexico. Neurology 1981; 31:1489-92. [PMID: 7198197 DOI: 10.1212/wnl.31.11.1489] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The incidence and prevalence of multiple sclerosis (MS) in Los Alamos County, New Mexico, were investigated because the number of reported cases appeared to have increased. The point prevalence on November 1, 1979, was 75.7 per 100,000, and average annual incidence rates for the period 1960-1969 and 1970-1979 were 3.4 and 3.7 per 100,000, respectively. The rates of MS in Los Alamos County were greater than expected from previous epidemiologic surveys of North America. The unusual ethnic composition and high socioeconomic level of the population probably contributed to the increases.
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235
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Davis LE, Standefer JC, Kornfeld M, Abercrombie DM, Butler C. Acute thallium poisoning: toxicological and morphological studies of the nervous system. Ann Neurol 1981; 10:38-44. [PMID: 7271231 DOI: 10.1002/ana.410100108] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Nine days following ingestion of 5 to 10 gm of thallium nitrate, a young man died with severe cranial and peripheral neuropathy, anuria, and heart failure. Ultrastructural examination of nerves obtained on days 7 and 9 demonstrated axonal degeneration with secondary myelin loss. Axons were swollen and contained distended mitochondria and vacuoles. Thallium levels in more than twenty organs and body fluids ranged from below 1.0 to 178 microgram/gm; concentrations in twenty areas of the nervous system ranged from 29 to 140 microgram/gm. The highest brain levels of thallium were found in gray matter. In the thalamus, 87% of the thallium was present in cell sap. Tissue concentrations of thallium did not parallel those reported for potassium, suggesting that thallium distribution differs from potassium distribution in human beings.
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236
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Snyder RD, Stovring J, Cushing AH, Davis LE, Hardy TL. Cerebral infarction in childhood bacterial meningitis. J Neurol Neurosurg Psychiatry 1981; 44:581-5. [PMID: 7026737 PMCID: PMC491062 DOI: 10.1136/jnnp.44.7.581] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Forty-nine children with complicated bacterial meningitis were studied. Thirteen had abnormalities on computed tomography compatible with the diagnosis of brain infarction; one had a brain biopsy with the histological appearance of infarction. Factors exist in childhood bacterial meningitis which are associated with the development of brain infraction.
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237
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Davis LE. Communicating hydrocephalus in newborn hamsters and cats following vaccinia virus infection. J Neurosurg 1981; 54:767-72. [PMID: 7241186 DOI: 10.3171/jns.1981.54.6.0767] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Newborn hamsters and kittens infected with vaccinia virus developed communicating hydrocephalus without fibrotic changes in the meninges. Following intracerebral viral inoculation, a transient inflammation of the meninges, ependyma, and choroid plexus was found. One month later, 70% of hamsters infected with the WR strain of vaccinia virus and 35% infected with the vaccine strain developed hydrocephalus. The mechanism of hydrocephalus production is unclear, but differs from other models in which it is associated with stenosis of the aqueduct of Sylvius or fibrosis of the subarachnoid space.
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Neff-Davis CA, Davis LE, Gillette EL. Warfarin in the dog: pharmacokinetics as related to clinical response. J Vet Pharmacol Ther 1981; 4:135-40. [PMID: 7349326 DOI: 10.1111/j.1365-2885.1981.tb00722.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Warfarin was administered intravenously (i.v.) as a single dose of 1.5 mg/kg to healthy dogs and the pharmacokinetic parameters were investigated. Elimination could be described by a one-compartment open model. Values for the elimination half-life and apparent specific volume of distribution were 14.5 +/- 4.1 h and 0.22 +/- 0.04 litre/kg, respectively. Oral maintenance doses were calculated from the data collected following i.v. administration and administered every 12 h for a total of five doses after an initial i.v. loading dose of 1.5 mg/kg. Prothrombin times increased from a control value of 8.6 +/- 0.3 sec to 55.2 +/- 5.2 sec over a period of 96 h. Prothrombin time returned to control values by 62 h after withdrawal of the drug. We propose a dosage regimen of warfarin for anticoagulant therapy in the dog of 0.22 mg/kg to be given orally every 12 h. Prothrombin time should be monitored during therapy and the dose of warfarin modified according to the degree of suppression of coagulation factors desired.
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McKiernan BC, Neff-Davis CA, Koritz GD, Davis LE, Pheris DR. Pharmacokinetic studies of theophylline in dogs. J Vet Pharmacol Ther 1981; 4:103-10. [PMID: 7349323 DOI: 10.1111/j.1365-2885.1981.tb00718.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The pharmacokinetics of theophylline were investigated in dogs following intravenous, single oral, and multiple oral doses of aminophylline. Mean half-life (t1/2) of theophylline following single intravenous administration was 5.7 h and the apparent specific volume of distribution (V'd area) was 0.82 litre/kg. The bioavailability of theophylline was high (91%) following oral administration of aminophylline tablets and the absorption half-life (t1/2ab) was 0.4 h. Theophylline plasma concentrations observed following repeated oral administration of aminophylline tablets were somewhat greater than predicted. This suggests that theophylline plasma concentrations should be monitored and the dosage regimen individually adjusted in critically ill animals.
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Neff-Davis CA, Davis LE, Gillette EL. Metronidazole: a method for its determination in biological fluids and its disposition kinetics in the dog. J Vet Pharmacol Ther 1981; 4:121-7. [PMID: 7349324 DOI: 10.1111/j.1365-2885.1981.tb00720.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A method for the analytical determination of metronidazole concentrations in biological tissues was developed using high performance liquid chromatography. The procedure was employed to investigate the pharmacokinetics of metronidazole in dogs following intravenous and oral administration (44 mg/kg). The overall elimination rate constant beta was 0.0027 +/- 0.0005 min-1, the apparent specific volume of distribution (V'd) was 0.948 +/- 0.096 L/kg overall clearance (ClB) was 2.49 +/- 0.54 ml/kg/min and the rate constant for absorption Kab was 0.0456 +/- 0.0353 min-1. Oral bioavailability was high but variable (59%-100%). Implications of these data for chemotherapy of infections caused by anaerobic bacteria, trichomonads, and Giardia and for the sensitization of hypoxic neoplastic cells to radiotherapy are discussed.
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Davis LE, Johnsson LG, Kornfeld M. Cytomegalovirus labyrinthitis in an infant: morphological, virological, and immunofluorescent studies. J Neuropathol Exp Neurol 1981; 40:9-19. [PMID: 6259297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The inner ears obtained from an infant who died of severe congenital cytomegalovirus infection were examined using virological and morphological methods. The techniques of microdissection and surface preparations, immunofluorescent microscopy, and transmission and scanning electron microscopy were employed. Cytomegalovirus was isolated from the perilymph. Injury to the cochlea was minor and was confined to the first half of the basal turn. There were signs of a severe labyrinthitis of the vestibular endolymphatic system. Vestibular organs, especially the saccule and utricle, showed severe damage, with collapse of the saccular membranous wall. Inclusion-bearing cells containing cytomegalovirus antigen, as shown by immunofluorescent staining, and cytomegalovirus virions, as observed by electron microscopy, were found on the endolymphatic surface of the membranous walls, mainly in the saccule and utricle. In the utricle, the infected cells appeared to be concentrated in the regions where the so-called dark cells were located. These dark cells are similar to the proximal tubule cells in the kidney, another common target for cytomegalovirus infection.
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Froelich CJ, Searles RP, Davis LE, Goodwin JS. A case of Guillain-Barré syndrome with immunologic abnormalities. Ann Intern Med 1980; 93:563-5. [PMID: 7436188 DOI: 10.7326/0003-4819-93-4-563] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Guillain-Barré syndrome and the nephrotic syndrome developed in a patient simultaneously. Analysis of renal biopsy by light, immunofluorescent, and electron microscopy showed lipoid nephrosis. T-cell lymphocytopenia, lymphocytotoxic antibodies, depressed lymphocyte mitogenesis, and anergy also complicated the illness. The immunologic abnormalities resolved when the polyradiculoneuritis and lipoid nephrosis remitted. This previously undescribed association illustrates the occurrence of two postulated cell-mediated autoimmune disorders despite the presence of depressed cell-mediated immunity.
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Abstract
Although botulinum toxin is thought not to affect the human CNS, previous studies have not examined those behaviors, such as memory, that have been shown to be dependent on central acetylcholine transmission. In eight patients with type A botulism, subjective analysis, bedside memory testing, and formal memory testing with Hebb's verbal sequencing test, Corsi's nonverbal sequencing test, and Buschke's verbal serial list learning test failed to demonstrate impairment in immediate and recent memory. Botulism severe enough to block peripheral nicotinic and muscarinic cholinergic transmission does not block those central cholinergic synapses involved in memory.
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Abstract
We report fatal Reye's syndrome in two adults following proven influenza A viral infections. Reye's syndrome is, therefore, not confined to children but may also occur in adults. Many reported cases of postinfluenza A encephalopathy have clinical and pathological features of Reye's syndrome suggesting that they are not due to postinfectious perivenous demyelination.
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Davis LE, Neff-Davis CA, Wilcke JR. Monitoring drug concentrations in animal patients. J Am Vet Med Assoc 1980; 176:1156-8. [PMID: 7216892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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249
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Davis LE. Pharmacologic control of vomiting. J Am Vet Med Assoc 1980; 176:241-2. [PMID: 7364635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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250
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Davis LE. Clinical pharmacology of salicylates. J Am Vet Med Assoc 1980; 176:65-6. [PMID: 7351386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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