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  • Author or Editor: D. A. Grosenbaugh x
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SUMMARY

In this study, we described water-insoluble proteins extracted from the germinative regions (stratum internum and coronary band epithelium) and the cornified outer surface (stratum medium) of the equine hoof wall. Two major types of polypeptides were identified: the intermediate filaments (if) and the if-associated proteins. The if, including keratins, composed a major portion of this fraction, had electrophoretic mobilities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the range of 40 to 80 kDa, and reacted with acidic or basic keratin-specific monoclonal antibodies. Differences in the composition of keratins between germinative layers and the stratum medium were seen. Another less well-characterized group of polypeptides associated with the if also were extracted with the water-insoluble polypeptide fraction. These associated proteins had an apparent molecular weight between 10 and 30 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and contained a higher percentage of sulfur-containing amino acids than did the if. Water-insoluble protein fractions compared favorably with those found in other less-specialized keratinizing tissue with respect to size, immunoreactivity with monoclonal antibody, and amino acid composition.

Free access
in American Journal of Veterinary Research

SUMMARY

Objective

To determine and compare cardiorespiratory and recovery effects of sevoflurane, isoflurane, and halothane in horses.

Animals

8 clinically normal horses (4 mares, 4 geldings), 5 to 12 years old.

Procedure

Inhalation anesthesia was maintained for 90 minutes with sevoflurane, isoflurane, or halothane. Anesthesia depth was maintained at 1.5 minimum alveolar concentration of halothane, isoflurane, and sevoflurane, then was reduced at 30 and 60 minutes. A surgical plane of anesthesia was reinduced by administration of ketamine or thiopental or by increasing the fractional inspired concentration of sevoflurane. Cardiovascular and pulmonary variables were recorded and compared among inhalation anesthetics. Recovery was monitored, and subjective assessment of recovery quality was performed.

Results

Hemodynamic and pulmonary indices during sevoflurane anesthesia were similar to those of isoflurane. Cardiac output and systemic arterial pressure decreased less during sevoflurane and isoflurane anesthesia than during halothane anesthesia. After 90 minutes, cardiac output was greater for sevoflurane and isoflurane, respectively, compared with halothane. Mean arterial pressure was similar for all thre anesthetic agents. Respiratory rate for sevoflurane and isoflurane was less than that for halothane. This apparent respiratory depression correlated with greater increase in Paco2 and decreased pH when sevoflurane and isoflurane were compared with halothane. Recovery from sevoflurane anesthesia was qualitatively similar and superior to recovery from isoflurane and halothane, respectively. Time to standing did not differ significantly between sevoflurane and isoflurane, but was shorter than halothane.

Conclusions

Sevoflurane induced cardiorespiratory effects that were comparable to those of isoflurane and halothane. Cardiac output was greater and respiratory rate was less than that for halothane at 1.5 MAC. Sevoflurane anesthesia was characterized by good control of anesthesia depth during induction, maintenance, and recovery. Recovery time after sevoflurane anesthesia was comparable to that for isoflurane, and recovery was smooth and controlled in a manner consistent with recovery from halothane. (Am J Vet Res 1998;59:101–106)

Free access
in American Journal of Veterinary Research

SUMMARY

Objective

To determine reliability of noninvasive methods of arterial oxyhemoglobin saturation (SpO2 ), end-tidal CO2 concentration (PEtCO2 and blood pressure (BP) determination during periods of hypoxemia and systemic arterial BP perturbations.

Animals

7 healthy, conditioned dogs weighing 19 to 22 kg.

Procedure

3 pulse oximeters, 2 capnometers, and 2 oscillometric BP monitors were used to measure oxygen-carrying capacity of the blood, heart rate, ventilatory status and arterial BP changes during hypoxemia, and altered arterial BP. Pulse oximeter-derived SpO2 and PEtCO2 were determined during rapidly induced plateaus of hypoxia (decreased fractional inspired oxygen concentration [FiO2 ) and altered systemic arterial BP. A lead-II ECG was used to monitor heart rate.

Results

Pulse oximetry provided an accurate assessment of fractional oxyhemoglobin saturation (SaO2 ) at SpO2 > 70%. As SaO2 decreased from 70%, the magnitude of the SpO2 error increased (20% error at SpO2 < 30%). The PEtCO2 was accurate at PaCO2 , ranging from 30 to 55 ± 5 mm of Hg under all experimental conditions. When PaCO2 was > 55 mm of Hg, both capnometers produced values that were as much as 20 mm of Hg less than the corresponding PaCO2 . Mean BP was least dependent on pulse wave quality, consistently underestimating mean arterial BP by approximately 10 mm of Hg.

Conclusions and Clinical Relevance

The pulse oximeters tested provided an accurate estimation of SaO2 at SpO2 > 70%. A PEtCO2 value > 55 mm of Hg may represent hypercapnia that is more profound than indicated. Systolic BP determinations were most accurate during hypotensive states and least accurate during hypertension. Diastolic BP measurements were generally more accurate during hypertension than normotension. Accuracy is not appreciably affected by hypotension resulting from vasodilation or blood loss. The tendency to underestimate systemic arterial BP should not interfere with trend detection during unstable clinical conditions. (Am J Vet Res 1998;59:205–212)

Free access
in American Journal of Veterinary Research

Objective

Evaluation of a portable clinical analyzer for determination of blood gas tensions, electrolyte and glucose concentrations, and Hct in a hospital setting.

Design

Prospective study.

Animals

50 dogs, 50 cats, and 28 horses, all clinically normal.

Procedure

Blood samples were analyzed on a portable clinical analyzer to determine concentrations of sodium, potassium, chloride, BUN, glucose, and ionized calcium and values of Hct, pH, Pco2, and Po2. Values obtained were compared with those obtained from the same blood samples, using a standard automatic analyzer (serum sodium, potassium, chloride, BUN, and glucose concentrations), a cell counter (Hct), a blood gas analyzer (pH, Pco2, Po2), and a calcium-pH analyzer (ionized calcium). Bias (mean difference between values obtained on the same sample by different methods) and variability (SD of differences) were determined for all values. Data were also subjected to Deming regression analysis.

Results

Correlation coefficients were > 0.90 for all values except potassium and ionized calcium concentrations. Bias and variability were within clinically acceptable limits (± 2 SD) for all but potassium, ionized calcium, and glucose concentrations and Hct. Species-dependent variability was observed for glucose concentration and Hct.

Clinical Implications

Most differences between values obtained with the portable clinical analyzer and standard clinical laboratory systems could be accounted for by differences in type of sample tested (blood vs serum). The portable clinical analyzer is suitable for point-of-care analysis in critical care situations and for routine blood biochemical analysis when extensive laboratory support is unavailable. (J Am Vet Med Assoc 1998;213:691-694)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the safety and efficacy of a vaccine containing plasmid DNA with an insert encoding human tyrosinase (ie, huTyr vaccine) as adjunctive treatment for oral malignant melanoma (MM) in dogs.

Animals—111 dogs (58 prospectively enrolled in a multicenter clinical trial and 53 historical controls) with stage II or III oral MM (modified World Health Organization staging scale, I to IV) in which locoregional disease control was achieved.

Procedures—58 dogs received an initial series of 4 injections of huTyr vaccine (102 μg of DNA/injection) administered transdermally by use of a needle-free IM vaccination device. Dogs were monitored for adverse reactions. Surviving dogs received booster injections at 6-month intervals thereafter. Survival time for vaccinates was compared with that of historical control dogs via Kaplan-Meier survival analysis for the outcome of death.

Results—Kaplan-Meier analysis of survival time until death attributable to MM was determined to be significantly improved for dogs that received the huTyr vaccine, compared with that of historical controls. However, median survival time could not be determined for vaccinates because < 50% died of MM before the end of the observation period. No systemic reactions requiring veterinary intervention were associated with vaccination. Local reactions were primarily limited to acute wheal or hematoma formation, mild signs of pain at the injection site, and postvaccination bruising.

Conclusions and Clinical Relevance—Results support the safety and efficacy of the huTyr DNA vaccine in dogs as adjunctive treatment for oral MM.

Impact for Human Medicine—Response to DNA vaccination in dogs with oral MM may be useful in development of plasmid DNA vaccination protocols for human patients with similar disease.

Full access
in American Journal of Veterinary Research