American journal of veterinary research
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Flow-volume loops generated from 6 Standardbreds at rest and during treadmill exercise were evaluated for their use in detecting upper airway obstruction. Tidal breathing flow-volume loops (TBFVL) were obtained from horses at rest and exercising at speeds corresponding to 75% of maximal heart rate and at maximal heart rate. The TBFVL were evaluated, using a pulmonary function computer; calculated indices describing airflow rate and expiratory-to-inspiratory airflow ratio for individual loops were determined. ⋯ Inspiratory impedance also increased after LRLN. Although in resting horses TBFVL were not a useful indicator of upper airway obstruction, examination of TBFVL from exercising horses allowed objective, specific, and repeatable detection of upper airway obstruction. The technique was noninvasive, rapid, and well tolerated by horses; thus, it is a potentially valuable clinical diagnostic test.
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Intestinal ischemia was induced and maintained for 60 minutes in male Sprague-Dawley rats weighing 175 to 225 g. Prior to reperfusion, the following drugs were administered via the caudal vena cava: 0.9% NaCl (0.5 ml), superoxide dismutase (SOD; 1,000 IU/kg of body weight), polyethylene glycol-conjugated SOD (PEG-SOD; 1,000 IU/kg), or the 21-aminosteroids, U74006F (3 mg/kg) or U78715G (3 mg/kg). A sham-operated control group was included. ⋯ In all rats, villus height was comparable to, or was greater than villus height in sham-operated controls by 18 hours after reperfusion in all animals and remained constant through 7 days. Administration of the 21-aminosteroids maintained villus height after ischemia and reperfusion. Treatment with PEG-SOD did not maintain villus height to the degree observed in rats treated with SOD.
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Comparative Study
Anatomy of the prepubic tendon in the horse, cow, sheep, goat, and dog.
Analyses of the fibers in the prepubic tendon of the horse and ruminants have shown that it is composed of the crossed and uncrossed tendons of origin of the pectineus muscles, the pelvic tendons of the rectus and obliquus abdominis muscles, and the tendons of origin of the cranial parts of the gracilis muscles. Pelvic attachments of the linea alba and the yellow abdominal tunic are incorporated in it. It is not a transverse ligament, and it is not homologous to the human superior (cranial) pubic ligament. ⋯ Conflicting descriptions in the literature were discussed and resolved by new approaches to the dissection. Studies of the inguinal region in the cat and pig were reviewed. A table of nomenclature is included.
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Cardiovascular and respiratory responses to variable PaO2 were measured in 6 horses anesthetized only with halothane during spontaneous (SV) and controlled (CV) ventilation. The minimal alveolar concentration (MAC) for halothane in oxygen was determined in each spontaneously breathing horse prior to establishing PaO2 study conditions--mean +/- SEM, 0.95 +/- 0.03 vol%. The PaO2 conditions of > 250, 120, 80, and 50 mm of Hg were studied in each horse anesthetized at 1.2 MAC of halothane and positioned in left lateral recumbency. ⋯ During SV, minute expired volume increased (P < 0.05) because respiratory frequency tended to increase as PaO2 decreased. Decrease in PaCO2 (P < 0.05) also accompanied these respiratory changes. Although oxygen utilization was nearly constant over all treatment periods, oxygen delivery decreased (P < 0.05) with decrease in PaO2, and was less (P < 0.05) during CV, compared with SV, for comparable PaO2 values.(ABSTRACT TRUNCATED AT 250 WORDS)
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Comparative Study
Comparison of intravenous and intramuscular routes of administering cosyntropin for corticotropin stimulation testing in cats.
Plasma cortisol and immunoreactive (IR)-ACTH responses to 125 micrograms of synthetic ACTH (cosyntropin) administered IV or IM were compared in 10 clinically normal cats. After IM administration of cosyntropin, mean plasma cortisol concentration increased significantly (P less than 0.05) within 15 minutes, reached maximal concentration at 45 minutes, and decreased to values not significantly different from baseline concentration by 2 hours. After IV administration of cosyntropin, mean plasma cortisol concentration also increased significantly (P less than 0.05) at 15 minutes, but in contrast to IM administration, the maximal cortisol response took longer (75 minutes) and cortisol concentration remained significantly (P less than 0.05) higher than baseline cortisol concentration for 4 hours. ⋯ Mean plasma IR-ACTH concentration returned to values not statistically different from baseline by 60 minutes after IM administration of cosyntropin, whereas IR-ACTH concentration still was higher than baseline concentration 6 hours after IV administration. Peak plasma IR-ACTH concentration and area under the plasma IR-ACTH response curve also were significantly (P less than 0.05) higher after IV administration of cosyntropin. Results of the study confirmed that IV administration of cosyntropin induces significantly (P less than 0.05) greater and more prolonged adrenocortical stimulation than does IM administration.(ABSTRACT TRUNCATED AT 250 WORDS)