Plethysmographic comparison of breathing pattern in heaves (recurrent airway obstruction) versus experimental bronchoconstriction or hyperpnea in horses     

Hoffman AM  Oura TJ  Riedelberger KJ  Mazan MR 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(1):184-192

BACKGROUND: Horses with recurrent airway obstruction (heaves) are described as exhibiting "increased abdominal effort," but it is unknown whether this translates to an effective contribution to ventilation. HYPOTHESIS: We hypothesized that heaves is characterized by asynchrony between rib cage and abdominal motions, and that the abdominal component is the major contributor to ventilation. ANIMALS: The rib cage versus abdominal motion in naturally occurring heaves (n = 15) was compared to controls at rest (n = 7) and during hyperpnea because of lobeline treatment, and the effects of histamine-induced bronchoconstriction in controls (n = 10). METHODS: Flow patterns, phase angle (theta) between the rib and abdominal compartments, abdominal (Vabd) contribution to tidal volume (VT), and lung mechanics were measured. RESULTS: Findings unique to the heaves group included the loss of biphasic expiratory flow, severely increased theta with the abdomen consistently lagging behind the rib cage, and a reduced contribution of the abdomen to ventilation. A subgroup of heaves (n = 5) with abdominal paradox showed a significant (P < .05) reduction in tidal volume, and increased respiratory rate. Bronchodilation reduced theta in heaves (P = .06), but theta remained significantly higher after bronchodilation than found in controls. CONCLUSIONS AND CLINICAL IMPORTANCE: We conclude that breathing pattern in horses with heaves is characterized by severe rib cage/abdominal asynchrony, with the rib cage motion in synchrony with flow, therefore dominating ventilation. In a subset of heaves, the abdominal compartment (diaphragm, abdominal muscles) was completely out of synchrony with flow ("abdominal paradox") despite the clinical appearance of "increased abdominal effort."  相似文献   

Effect of aerosolized albuterol sulfate on resting energy expenditure determined by use of open-flow indirect calorimetry in horses with recurrent airway obstruction     

Mazan MR  Hoffman AM  Kuehn H  Deveney EF 《American journal of veterinary research》2003,64(2):235-242

OBJECTIVE: To evaluate effects of sedation on stability of resistance of the respiratory system (RRS) and measures of resting energy expenditure (REE) by use of open-flow indirect calorimetry (IC) and treatment with aerosolized albuterol on REE in horses with recurrent airway obstruction (RAO). ANIMALS: 9 clinically normal horses and 8 horses with RAO. PROCEDURE: In phase 1, RRS was measured by using forced oscillometry (FOT) in 5 clinically normal horses before and after sedation with xylazine. In phase 2, REE was measured in 4 clinically normal horses between 20 and 25 minutes and again 35 to 40 minutes after sedation with xylazine. In phase 3, IC was performed between 20 and 25 minutes and FOT was performed between 30 and 35 minutes after xylazine administration in 8 horses with RAO; after administration of 450 microg of albuterol, IC and FOT were repeated. RESULTS: In phase 1, RRS values were significantly lower 5 and 10 minutes after sedation. In phase 2, diminishing sedation did not significantly affect REE. In phase 3, there was a significant decrease in mean RRS (1.15 +/- 0.25 vs 0.84 +/- 0.14 cm H20/L/s) and REE (30.68 +/- 17.89 vs 27.46 = 16.54 kcal/kg/d) after albuterol administration. CONCLUSIONS AND CLINICAL RELEVANCE: FOT and IC are useful in obtaining repeatable measurements of RRS and REE, respectively, in sedated horses. Concurrent bronchodilation and decreased REE after albuterol administration suggest that increased work of breathing as a result of airway obstruction may contribute to increased energy demands in horses with RAO.  相似文献   

Diaphragmatic paralysis due to phrenic nerve degeneration in a llama     

Bedenice D  Mazan MR  Kuehn H  Hoffman AM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(5):603-606

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Retracted: Effect of Post‐Thaw Storage Time on Motility and Fertility of Cryopreserved Beluga Sturgeon (Huso huso) Sperm          下载免费PDF全文

MS Aramli  RM Nazari  MR Gharibi 《Reproduction in domestic animals》2015,50(2):349-352

The aim of this study was to test the influence of post ‐ thaw storage time on the duration of sperm motility, percentage of motile sperm, and fertilization and hatching rates of fresh sperm and sperm stored for 0, 30 and 60 min at 4°C post‐thawing. After being frozen in liquid nitrogen and then thawed, the percentage of motile sperm and duration of motility were not affected by 30 min of storage at 4°C, whereas a significant decline in these parameters was observed after 60 min of storage. Similarly, fertilization and hatching rates were significantly affected within 60 min of storage at 4°C, and the fertility of frozen‐thawed sperm was significantly lower than that of fresh sperm. We conclude that cryopreserved sperm of beluga sturgeon could be stored for 30 min without the loss of sperm quality. This described procedure for beluga sturgeon cryopreservation is reliable and efficient and therefore can be recommended for hatchery practice after scaling up this technique.  相似文献   

The Influence of Morphology,Follicle Size and Bcl‐2 and Bax Transcripts on the Developmental Competence of Bovine Oocytes     

THC De Bem  PR Adona  FF Bressan  LG Mesquita  MR Chiaratti  FV Meirelles  CLV Leal 《Reproduction in domestic animals》2014,49(4):576-583

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Rhodococcus equi-associated osteomyelitis in foals     

EC FIRTH  MR ALLEY†  H HODGE 《Australian veterinary journal》1993,70(8):304-307

Two cases of Rhodococcus equl infection in foals are described, in which osteomyelitis was a feature. Because rhodococcal infection is usually low grade and chronic, and because the signs of early metaphysitis can be subtle, any articular or periarticular swelling in a foal from a farm with a history of rhodococcosis should be strongly suspected to be associated with R equl until proven otherwise.  相似文献   

Reply     

MR ALDERTON 《Australian veterinary journal》1993,70(11):429-430

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Effects of aerosolized albuterol on physiologic responses to exercise in standardbreds.     

M R Mazan  A M Hoffman 《American journal of veterinary research》2001,62(11):1812-1817

OBJECTIVE: To examine the effects of an aerosolized beta2-adrenoreceptor agonist, albuterol, on performance during a standardized incremental exercise test in clinically normal horses. ANIMALS: 8 Standardbred pacing mares. PROCEDURE: Clinically normal horses, as judged by use of physical examination, hematologic findings, serum biochemical analysis, and airway endoscopy, were randomly assigned to 2 groups and were given 900 microg of albuterol via a metered-dose inhaler 30 minutes before beginning a standardized incremental exercise test in a crossover design with a 7-day minimum washout. Further examination included measurement of baseline lung mechanics, response to histamine bronchoprovocation, and bronchoalveolar lavage. RESULTS: No significant differences (albuterol vs placebo) were seen for any incremental exercise test variables (ie, maximum oxygen consumption, maximum carbon dioxide consumption, respiratory quotient, treadmill speed at heart rate of 200 beats/min, or number of steps completed during an incremental exercise protocol). Mast cell percentage was significantly (r = -0.84) associated with the concentration of aerosolized histamine that evoked a 100% increase in total respiratory system resistance. No other direct correlations between bronchoalveolar lavage fluid cell types and any indices of exercise capacity or airway reactivity were found. CONCLUSIONS AND CLINICAL RELEVANCE: Although no horse had exercise intolerance, 4 horses had airway hyperreactivity with bronchoalveolar lavage fluid mastocytosis; these horses may have been subclinically affected with inflammatory airway disease. In our study, albuterol did not enhance performance in 8 clinically normal racing-fit Standardbreds.  相似文献   

Hydrops foetalis in dwarf calves associated with twinning     

PAW HARPER  MR LATTER  JF WILKINS 《Australian veterinary journal》1995,72(6):236-238

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Evaluation of head-out constant volume body plethysmography for measurement of specific airway resistance in conscious, sedated sheep     

Bedenice D  Bar-Yishay E  Ingenito EP  Tsai L  Mazan MR  Hoffman AM 《American journal of veterinary research》2004,65(9):1259-1264

OBJECTIVE: To evaluate the use of a modified whole body plethysmograph in awake sheep. ANIMALS: 10 healthy adult sheep. PROCEDURE: Concurrent measurements of specific airway resistance (sR(aw)) and pulmonary resistance (R(L)) were obtained using a novel noninvasive head-out constant-volume plethysmograph and esophageal balloon-pneumotachography, respectively. All data were collected before and after external resistive loading with 1 and 5.6 cm H2O/L/s. Functional residual capacity (FRC) was measured by helium dilution for computation of airway resistance (R(aw)) preloading (R(aw) = sR(aw)/FRC). RESULTS: The sR(aw) and R(L) were closely correlated in 10 adult sheep. Additionally, sR(aw), and R(L) accurately reflected the magnitude of added resistance. The mean FRC was 52 mL/kg and used to calculate R(aw). At baseline, the values for R(aw) were significantly correlated with sR(aw) and R(L). CONCLUSIONS AND CLINICAL RELEVANCE: Precise measurements of sR(aw) and R(aw) at baseline and sR(aw) after external resistive loading were obtained by use of this novel noninvasive plethysmographic technology. This method should have application to veterinary patients or animals used in research in which noninvasive rapid or serial measurements of sR(aw) in the conscious state are required.  相似文献