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Biomedical subjects

T C Amis

Publications and source records attributed to T C Amis.

54 records · Page 3Linked to original sources
PubMed1986

Upper airway obstruction in canine laryngeal paralysis.

The type and the severity of airway obstruction in 30 dogs with bilateral laryngeal paralysis was assessed, using tidal breathing flow-volume loop (TBFVL) analysis. The dogs had clinical evidence of mild-to-severe upper airway obstruction (ie, respiratory distress, exercise intolerance, stridor). Seventeen dogs had TBFVL consistent with a nonfixed (inspiratory) obstruction, 10 had TBFVL indicative of a fixed (inspiratory/expiratory) obstruction, and 3 had normal TBFVL. Analysis of TBFVL confirmed that dogs with laryngeal paralysis have upper airway obstruction that differs in type and severity. Use of TBFVL provided a quantitative evaluation of airway obstruction and demonstrated the effects of bilateral laryngeal paralysis on the breathing patterns of dogs.

Airway Obstruction↗
PubMed1986

Pattern of breathing in brachycephalic dogs.

The pattern of breathing was assessed in 19 brachycephalic dogs, using tidal breathing flow-volume loop (TBFVL) analysis. Fifteen dogs had TBFVL consistent with a fixed-type upper airway obstruction, whereas 4 dogs had a TBFVL indicative of a nonfixed upper airway obstruction. The dogs did not have a TBFVL shape the same as that considered normal for healthy nonbrachycephalic dogs. Tidal breathing flow-volume loops from brachycephalic dogs that were considered to have a normal respiratory tract (n = 11) were similar to those of dogs with clinical signs of upper airway obstruction (n = 8). Respiration was monitored continuously for short periods (20 to 50 minutes) in 3 brachycephalic dogs resting in a cage in a quiet, darkened laboratory; 2 of these dogs had periodic breathing patterns characterized by multiple episodes of alternating hypopnea and arousal. Brachycephalic dogs may be at risk for the development of disordered breathing during sleep.

Airway Obstruction↗
PubMed1986

Systematic identification of endobronchial anatomy during bronchoscopy in the dog.

The endobronchial anatomy of 10 inflated, air-dried, canine lungs and 8 healthy anesthetized, sternally recumbent, mixed-breed dogs was evaluated, using a flexible fiberoptic bronchoscope. On the basis of the order of branching of lobar and segmental bronchi observed in these lungs, a nomenclature system was devised to systematically identify individual lobar, segmental, and subsegmental bronchi during bronchoscopy in the dog.

Animals↗
PubMed1986

Effects of lateral recumbency on regional lung function in anesthetized horses.

Six horses were anesthetized and placed in lateral recumbency for 1 hour and then were turned to the opposite side for an additional hour. A short-lived radioactive gas, 81mKr, was used to determine the relative spatial distribution of ventilation (V) and perfusion (Q) in these horses. Effects of time, side down, and turning on the distribution were evaluated. A consistent gradient of V/Q was found at all times, with the highest V/Q values at the top (non-dependent) portion of the lung field and the lowest at the bottom (dependent). This gradient was also present within each lung, as well as between lungs. Effects of time were not observed. Horses starting in right lateral recumbency had larger gradients of V/Q than did those starting on the left. The gradient decreased after turning in both groups. After turning, the gradients in the right lung were again greater han those in the left lung.

Anesthesia, General↗
PubMed1985

Laryngeal paralysis in dogs: a review of 23 cases.

The medical records of 23 dogs with laryngeal paralysis were reviewed. Although the condition developed mainly in old, large- or giant-breed dogs, a wide range of breeds was involved. The age of affected animals ranged from 7 months to 14 years. Respiratory distress, exercise intolerance, noisy breathing, and hoarse bark were common signs of the paralysis. Laboratory evaluations for hypothyroidism were performed on 11 dogs; only 3 were judged to have primary hypothyroidism. Males, particularly if castrated, were more frequently affected than females. A neurologic examination was performed on 6 dogs; 4 of them were found to have generalized neuromuscular disease.

Age Factors↗
PubMed1985

Laryngeal carcinoma in a cat.

Laryngeal neoplasia was diagnosed in a 5-year-old domestic shorthair cat examined for cough and gagging episodes. Resection of the mass revealed a squamous carcinoma which had invaded the deep floor of the larynx. Primary neoplasia of the feline larynx is a rare condition but needs to be distinguished from other obstructive laryngeal conditions, using radiography, laryngoscopy and biopsy.

Animals↗
PubMed1984

Effect of posture on inter-regional distribution of pulmonary ventilation in man.

Regional ventilation per unit alveolar volume (V/VA) and regional lung expansion (FRCR/TLCR) were measured in twelve normal male human subjects in seated, supine, lateral decubitus and prone postures using a gamma camera and inhalation of the radioactive gases 81Krm (half-life 13 sec) and 85Krm (half-life 4.4 h). FRCR/TLCR decreased from superior to inferior in all postures except prone where it was uniform; V/VA increased from superior to inferior except in the prone position where it was uniform. In the horizontal axis FRCR/TLCR and V/VA were uniformly distributed except for cranial to caudal gradients (with lower values caudally) in supine and lateral decubitus postures. In the prone posture V/VA tended to be higher in caudal lung zones.

Adult↗
PubMed1984

Effect of posture on inter-regional distribution of pulmonary perfusion and VA/Q ratios in man.

Using a gamma camera regional pulmonary perfusion per unit alveolar volume (Q/VA) and ventilation-perfusion ratios (VA/Q) were measured in fourteen normal male volunteers in upright, supine, lateral decubitus, prone and prone suspended postures with inhalation and intravenous infusion of radioactive 81Krm (half-life 13 sec) and inhalation of radioactive 85Krm (half-life 4.4 h). In the vertical axis, Q/VA increased from upper to lower lung regions in upright, lateral decubitus, prone and prone suspended postures but was uniform in supine and within the dependent lung in decubitus postures. Horizontally, Q/VA decreased from cranial to caudal in lateral decubitus, prone suspended, and near the diaphragm in supine. Vertically, VA/Q decreased from upper to lower in all postures except in supine and within the dependent decubitus lung where it increased. VA/Q tended to increase from cranial to caudal in horizontal postures. The effects of gravity on Q/VA and VA/Q vertical distributions are modified when FRC is low (supine, lower decubitus lung) because perfusion is more uniformly distributed. Horizontal gradients of Q/VA and VA/Q are more pronounced under conditions of high local lung volume but also occur in postures where FRC is low.

Adult↗
PubMed1984

Topographic distribution of pulmonary ventilation and perfusion in the horse.

The regional distribution of ventilation to perfusion ratios (VA/Q) in the lungs of 8 healthy standing Thoroughbred geldings (4.4 +/- 1.5 years, 465.7 +/- 46.6 kg) was studied, using steady-state inhalation and IV infusion of the radioactive gas krypton-81m. The VA/Q was uniformly distributed within a vertical lung strip centered over the 9th rib on the right side. Ventilation per unit of alveolar volume (V/VA) assessed from the clearance of inhaled radioactive gas in 5 horses increased from 0.49 +/- 0.13 (arbitrary units) in nondependent lung zones to 1.45 +/- 0.16 in dependent lung zones. Seemingly, a vertical gradient of pulmonary ventilation exists in the horse that is matched by a similar gradient of perfusion.

Animals↗
PubMed1982

A conscious dog model for study of regional lung function.

Using a specially designed mask and steady-state administration of the short-lived radioactive gas 81mKr, we measured the distribution of the ventilation-perfusion ratio (VA/Q) in the lungs of normal conscious standing greyhound dogs during tidal breathing. This model allows measurement of regional lung function unaffected by anesthesia and mechanical ventilation. An assessment of the distribution of VA/Q in the lungs of normal greyhound dogs revealed that topographically, ventilation and blood flow are well matched in the conscious dog.

Animals↗
PubMed1980

Regional lung function in bilateral diaphragmatic paralysis.

1. The distribution of regional function in the lungs of six patient with bilateral diaphragmatic paralysis was investigated by continuous inhalation and infusion of the radioactive gases 81mKr and 85mKr during tidal breathing. 2. In the supine and right lateral decubitus postures the vertical distribution of ventilation per unit alveolar volume was less in the dependent zones, the reverse of that found in normal subjects. In the upright posture ventilation was slightly decreased at the lung base. Perfusion per unit alveolar volume was more uniformly distributed than normally in the upright posture, and decreased from superior to inferior in the supine posture. In the lateral decubitus posture, perfusion of the lower lung was greater than that of the upper. Ventilation/perfusion ratios were more uniformly distributed in the patients than in normal subjects, except in the right lateral decubitus posture. 3. Alterations in the distribution of ventilation may be explained in terms of the altered mechanical interaction of chest wall, mediastinal and abdominal contents, with selective use of intercostal and accessory muscles. The effects on the distribution of blood flow are probably related to the low end-expiratory lung volume.

Adult↗
PubMed1975

Levamisole as a microfilaricidal agent in the control of canine dirofilariasis.

The effectiveness of levamisole hydrochloride as a microfilaricidal agent when used 3 weeks after thiacetarsamide sodium therapy for canine dirofilariasis, was studied in 6 experimental dogs and 20 clinical cases. The drug, when administered orally in gelatine capsules daily, cleared microfilariae from the circulation in the experimental dogs in 7 to 11 days. A dose rate of 10mg/kg appeared as effective as 15mg/kg. In the clinical group 70% of dogs had zero microfilarial counts after 4 to 8 doses at 10mg/kg daily. Vomiting, diarrhoea and inappetence were observed in some animals, but were not a significant problem. Elevations in plasma GPT and AP levels were recorded during the administration of levamisole in some dogs while GOT levels rose in 1 dog only. Urea and creatinine levels were unaffected in all dogs. The only haematological parameter affected was the eosinophil count which rose during levamisole administration. All levamisole-treated animals, were successfully commenced on daily DEC, as a prophylactic measure, while an anaphylactic-type reaction occurred when this drug was administered to 1 of the 2 control animals.

Alanine Transaminase↗