Ground surface nature can influence visual information contribution in postural control.

BACKGROUND: In sport, the nature of ground surface is likely to influence the contribution of visual information on postural control. Boxing and wrestling are respectively practiced on firm and soft ground surfaces. The aim was to compare the postural control of boxers with that of wrestlers on stable (firm) and unstable (soft and dynamic) ground surfaces, with and without deprivation of vision. METHODS: Fifteen male international boxers and 15 male international wrestlers presenting the same anthropometrics characteristics and the same number of years of sports practice were recruited. Spatiotemporal parameters of displacement of the center of feet pressure (COP) were measured on a force platform in static (firm and foam surfaces with eyes open and eyes closed) and dynamic conditions (medio/lateral and antero-posterior directions with eyes open and eyes closed). RESULTS: The results mainly showed a significant vision × group interaction in the antero-posterior direction for the dynamic postural condition (P<0.017). This indicated that the contribution of visual information was greater for the boxers than for the wrestlers in challenging condition (P=0.030). CONCLUSIONS: Further studies are needed to confirm whether the nature of ground surface influences the contribution of visual information, which can be, in turn, affected by the specificity of motor skills.

Elastic properties of the oesophageal wall in the dynamic measurement of intrathoracic pressure in cattle.

The elastance of the midthoracic portion of the oesophagus was measured in 14 healthy Dutch Friesians. These were divided into three groups with mean ages of six, 126 and 1636 days, respectively. Mean elastance was 0.17, 0.10 and 0.06 kPa ml-1, respectively. The calculated percentage of error, in relating the endoesophageal pressure with that in the thorax, was found to be smaller than 1 per cent for each animal.

Upper airway resistance in healthy Friesian cattle.

Total pulmonary resistance (RL) and upper airway resistance (Ruaw) were measured in nine healthy unsedated Friesian cattle divided into three age groups. Mean values for these three groups of animals aged four, 188 and 1157 days were 0.32, 0.13 and 0.06 kPa litre-1 s for RL; 0.14, 0.09 and 0.05 kPa litre-1 s for Ruaw; and 0.45, 0.68 and 0.79 for the ratio Ruaw/RL respectively. Ruaw, measured with the head in the normal position, did not significantly differ from values obtained with the head in the horizontal position. Ruaw, measured with the head in the vertical position, was approximately three times greater than when measured in the two other positions.

Respiratory syncytial virus pneumonia in Friesian calves: physiological findings.

Clinical, serological and physiological values were measured during and after naturally occurring respiratory syncytial virus pneumonia in four Friesian calves weighing between 120 and 160 kg. Clinical and serological findings were in agreement with the description of spontaneous calf pneumonia, associated with respiratory syncytial virus infection. Pulmonary function values, recorded one, eight, 15 and 57 days after the clinical onset of the disease, provided good evidence that the clinical syndrome associated with respiratory syncytial virus infection in Friesian cattle is at first an acute obstructive disease which is progressively replaced by a moderate subclinical restrictive disease.

Pulmonary function testing in calves: technical data.

Measurements of airflow (V), tidal volume (Vt), and intrapleural pressure (Ppl) were tested for accuracy in 5 healthy Dutch Friesian calves with an average body weight of 153 kg. A face mask was constructed, using fiberglass and polyester, taking into account the typical facial morphology of the calf. It was tested for airtightness, dead space, laminarity of the expiratory V, and absence of saliva into the pneumotachograph. Three different systems for measuring Ppl (pleura puncturing, esophageal balloon catheter, and esophageal saline solution-filled catheter) were tested in vitro, in a Woulfe's flask, and in vivo, in the 5 calves previously described. Moreover, Ppl measured at 3 different puncture sites of the thorax and at 3 different thoracic positions of the esophagus were compared. The frequency-response was flat to 5 Hz for the intrapleural needle and the balloon catheter, but not for the saline solution-filled catheter. The pulmonary function values obtained by puncture of the pleura at the right 9th intercostal space on a line running from the tuber coxae to the shoulder joint and by the esophageal balloon catheter, the balloon being positioned between the crossing point with the aorta and the 2 largest caudal mediastinal lymph nodes, did not differ significantly. The Ppl changes during normal breathing were greatest in the ventral site of the thorax and in the caudal thoracic portion of the esophagus, less in the dorsal site of the thorax and the middle thoracic portion of the esophagus, and least in the cranial site of the thorax and the cranial thoracic portion of the esophagus.(ABSTRACT TRUNCATED AT 250 WORDS)

Longitudinal study of the effects of lungworm infection on bovine pulmonary function.

Clinical and physiologic investigations were done weekly in 5 nonsedated Friesian calves before, during, and after an induced infection with Dictyocaulus viviparus infective larvae. Clinical, hematologic, serologic, and parasitologic findings were all compatible with the classic picture of moderate subacute verminous bronchitis. Most pulmonary function values revealed significant (P less than or equal to 0.05) changes in the 2nd or 3rd week after inoculation and maximal changes at 5 weeks after inoculation. Most marked changes included a decrease in tidal volume, dynamic lung compliance, and arterial oxygen tension, and an increase in minute ventilation, minute viscous work of breathing, and alveolar-arterial oxygen difference. Minute ventilation, dynamic lung compliance, minute viscous work of breathing, and PaO2 revealed the most homogeneous change. Conversely, maximal change of intrapleural pressure, total pulmonary resistance, and viscous work of breathing had higher variability from week to week.

Effect of somatic growth on pulmonary function values in healthy Friesian cattle.

Growth-related changes in pulmonary function values (PFV) of cattle were investigated by a cross-sectional study of 40 healthy Dutch Friesian cattle, 3 days to 13 years of age and weighing 37 to 660 kg. Technical and methodologic procedures and body conformation and condition were standardized. A regression analysis was done with 4 independent variables (body weight, thoracic perimeter, body surface area, and age) and with PFV measured in this study. Ventilation values, dynamic lung compliance, and viscous work of breathing changed linearly with somatic growth. Respiratory frequency, total pulmonary resistance, and arterial oxygen tension showed an exponential relationship with all the independent variables. On the other hand, intrapleural pressure values were weakly correlated with body size indexes. The most important growth-related changes in PFV occurred at approximately 1 year of age. A significant (P less than or equal to 0.05) difference between immature and mature cattle was shown for the blood-gas values and the specific values of the breathing mechanics. The dynamic lung compliance/lung weight was lower and the total pulmonary resistance X minute volume was higher in cattle than in other domestic mammals. The regression equation, giving the best fit of the data, was selected for each PFV.

Effect of methacholine on mucociliary transport in bovine trachea in vitro.

A method is described to evaluate pharmacologic influence on bovine tracheal mucus transport in vitro. In this model, cholinergic agonist methacholine stimulated transport velocity. Methacholine at concentration of 10(-6)M increased velocity by 13.6%, whereas 10(-5)M increased velocity by 26%. Stimulation was inhibited by atropine.

Pathophysiologic study of 3-methylindole-induced pulmonary toxicosis in immature cattle.

In 5 Friesian calves given 3-methylindole (3-MI) (100 mg/kg once a week for 8 weeks, except calf 4, given a 50 mg/kg dose on weeks 3 to 8), pulmonary function (PF) values and arterial blood gas tensions (PaO2 and PaCO2) were measured 24 hours after dosing was done and were correlated with clinical, biochemical, and pathologic changes. Three of the calves (No. 1, 2, and 3) showed acute respiratory distress syndrome 24 hours after the first 3-MI treatment, with a large increase in respiratory frequency, minute viscous work, and PaCO2 and a large decrease in tidal volume, dynamic lung compliance, and PaCO2. They died 36, 38, and 84 hours after dosing. Pulmonary function changes were compatible with the severe pulmonary edema and alveolar damage observed at necropsy. The 2 other calves, after they were given the 1st dose, showed only subacute respiratory distress syndrome with less severe changes in PF values recorded at 24 hours. Furthermore, they became progressively more tolerant to the 2nd, 3rd, and 4th weekly treatments, and showed base-line PF values after the 5th weekly treatment. Pathologic changes were not observed in lung biopsy material from these 2 animals at 2 and at 12 weeks after the 8th (or last) 3-MI treatment.

Autonomic innervation of the airways.

A review is given of the literature concerning the autonomic innervation of airway smooth muscle. The cholinergic, adrenergic and non-cholinergic non-adrenergic (NANC) systems in humans and several animal species are discussed. The diagnostic and therapeutic possibilities and limitations of new receptor specific agonists and antagonists are also discussed.

In vitro transport of carbon in the trachea of veal calves.

Carbon transport was studied in vitro in preparations of trachea and bronchus from veal calves. The mean velocity varied from 4.2 mm/min in the main bronchi to 6.3 mm/min in the ventral trachea. In some locations no transport was observed. Stereomicroscopic evaluation of Alcian blue-phloxine stained mucosal surfaces revealed differences in the appearance of the mucus layer between locations with and without mucus transport. It is concluded that quality and integrity of the mucus layer play an important role in mucus transport.

Characterization of muscarinic receptors in equine tracheal smooth muscle in vitro.

This study was undertaken to assess the importance of muscarinic receptor subtypes in equine airway disease. Smooth muscle strips from the mid-cervical portion of the trachea of horses were placed in tissue baths and isometric contractile force was measured. Active force was measured in response to metacholine and the selective muscarinic receptor agonists McN-A-343 (M1-selective) and pilocarpine (M2-selective) in cumulative concentrations (10(-9)M through 10(-3)M), with and without preincubation with three or four concentrations of the selective muscarinic receptor antagonists pirenzepine (M1-selective), methoctramine (M2-selective), and 4-DAMP (M3-selective). The tissues contracted in response to all muscarinic agonists. The maximum responses (mean +/- sem) were 86.7 +/- 6.2 g for metacholine, 27.1 +/- 2.5 g for McN-A-343 and 37.6 +/- 3.5 g for pilocarpine. Preincubation with the selective muscarinic receptor antagonists resulted in dose-dependent rightward shifts of the concentration-effect curves for metacholine. pA2 values (means +/- sem) were 8.88 +/- 0.30 for 4-DAMP, 6.53 +/- 0.38 for methoctramine, and 6.72 +/- 0.31 for pirenzepine. Preincubation with 10(-7) M 4-DAMP resulted in a rightward shift of the concentration-effect curves for McN-A-343 and pilocarpine. These results indicate that the most important muscarinic receptor mediating contraction of equine tracheal smooth muscle is of the M3-type. Therefore relatively low concentrations of a M3-selective muscarinic receptor antagonist will inhibit acetylcholine-induced contraction of equine airway smooth muscle.

The effects of clenbuterol hydrochloride on the pulmonary function of calves with subacute and chronic bronchopneumonia.

The influence of clenbuterol on some pulmonary function tests in 11 calves with subacute and chronic bronchopneumonia has been investigated. Treatment with clenbuterol caused changes only in calves with subacute bronchopneumonia; in these animals it decreased the total pulmonary resistance, the viscous work per litre and the peak to peak changes in transpulmonary pressure.

Clenbuterol hydrochloride in calves with a natural bovine respiratory syncytial virus infection.

The effect of clenbuterol hydrochloride on the course of disease in calves with a natural bovine respiratory syncytial virus infection was examined. Six calves (three to nine months of age) originating from four herds with respiratory tract disease and serological evidence of a bovine respiratory syncytial virus infection were used in this study. The calves were injected intravenously with clenbuterol hydrochloride. The effect of clenbuterol on the course of disease was measured using the PO2 in blood taken from an indwelling canula inserted in the caudal auricular artery and by clinical signs. Clenbuterol did not improve clinical signs. After clenbuterol administration arterial PO2 values decreased significantly in five out of six patients. Six to eight hours after medication the mean arterial PO2 values were higher than initial values. The moderate positive effect of clenbuterol after six to eight hours may be caused by enhancing ciliary activity and by the secretolytic activity of clenbuterol.

Onion poisoning of young cattle.

Eighty-five cattle (calves and yearlings) were allowed 1000 kg of onions (Allium cepa) a day. Signs of poisoning were observed after five days; 22 animals were affected, one fatally. New illnesses continued to occur for five days after the withdrawal of onions from the diet. Clinical signs included inappetance, tachycardia, staggering and collapse, with jaundiced conjunctivae and haemoglobinuria. Haemolytic anaemia with Heinz bodies in the red cells and leucocytosis were demonstrated.

[Veterinary and clinical experience of the use of a beta2-receptor-stimulating sympathicomimetic agent (NAB 365) in horses with respiratory discase (author's transl)]. / Enkele veterinair-klinische ervaringen met het gebruik van een beta2-receptoren stimulerend sympaticomymeticum (NAB 365) bij paarden met longaandoeningen.

The manufacturers state that NAB 365 is a beta2-receptor-stimulating sympathicomimetic agent. According to the medical literature it combines a bronchial antispasmodic effect with certain bronchia secretolytic properties and has few untoward side-effects on, for instance, the heart and intestine. The effectiveness of administration of NAB 365 in horses with chronic or acute respiratory disease was tested in the Department of Veterinary Internal medicine in Utrecht. NAB 365 administered at a dosage of 0.8 gamma/kg, of body weight was found to have a marked bronchodilative effect in horses. There was also evidence of a bronchialsecretolytic effect. NAB 365 has a beneficial effect on respiration. At a dosage of 0.8 gamma/kg of body weight, twice daily, there are few side-effects, even when administration is continued for a fortnight. The clinical effect on respiration continued practically throughout the day.

Intrathoracic pressure measurement in cattle: standardized procedure.

A procedure to standardize the position of an esophageal catheter (eso-cat) tip, used to measure intrathoracic pressure, was tested in ten healthy Dutch Friesians. The cattle were in normal condition with body weights (BW) between 52 and 670 kg and thoracic perimeters (TP) between 80 and 210 cm. The position of the neck and head was standardized. The eso-cat was introduced via the nose into the thoracic portion of the esophagus. The distance between the nares and the eso-cat tip (Lcat), which was positioned between the crossing point with the aorta and the caudal mediastinal lymph nodes, was measured for each animal. The regression equation, calculated between the Lcat and the BW and TP was, respectively: Lcat (cm) = 65 + 0.115 x BW (kg) (r2 = 0.99) and Lcat (cm) = 22 + 0.535 x TP (cm) (r2 = 0.97). The corresponding residual standard deviations were respectively 2.52 and 4.37 cm. The multiple and curvi-linear regression equation did not give a significantly better fit of the data.

Physiological effects of experimental verminous bronchitis in Friesian calves.

Pulmonary function values were measured in five Friesian calves of five months of age during the patent phase of an experimental moderate lungworm infection and were compared with the pulmonary function values recorded in four control animals. All the nine calves were free of any previous challenge with Dictyocaulus viviparus and were submitted to the same standardized conditions of body conformation, housing, feeding and procedures for pulmonary function testing. A significant increase of respiratory rate, minute ventilation, total pulmonary resistance and power of breathing and a significant decrease of tidal volume, dynamic lung compliance and PaO2 were observed in the infested animals. The absolute intrapleural pressure values were also significantly more negative. The conclusions of the statistical analysis were almost identical when predicted instead of measured pulmonary function values were used in the control group. The clinical, functional and pathological findings in the infested animals were all consistent with the picture of a lower airway obstructive disease.