Spectra of the voluntary first cough sounds.

The voluntary cough sounds recorded according to Korpas and Sadlonova-Korpasova were sampled at a frequency of 20.000Hz and spectra of six consecutive windows of 50ms were estimated. To digitize signals an autotrigger mode was used. The subjects were healthy volunteers as well as patients with chronic bronchitis, asthma, bronchial carcinoma (growing intraluminarly in the 1st or in the 2nd or in the 3rd order bronchi), emphysema, laryngeal nerve paralyzis or laryngotomy. The duration of averaged cough sounds of patients was longer than that of healthy volunteers. The mean power of the spectra in the successive windows showed different patterns in the same group. In the third window of healthy volunteers (0.10 s-0.15 s) a high modulus broad bandwidth (between 1-2 kHz) spectrum was found which was considered as a bronchial "flute", and was probably related to the lowest resistance as well as to the velocity of airflow of cough manoeuvre. This pattern appeared with a delay and/or it was changed in the diseased groups compared to the healthy volunteers. Due to this delay, the spectra of the fifth window (0.20 s-0.25 s) showed somewhat higher harmonics (400-800 Hz) in the patients with chronic obstructive pulmonary diseases (COPD), carcinoma and laryngeal nerve paralyzis than in healthy volunteers. In emphysematous patients in the first (0.00-0.05 s), in the third (0.10-0.15 s) and in the fifth (0.20-0.25 s) windows the fundamental frequency was low (156-176 Hz) compared to that of the other groups. The paralyzed vocal cords functioning as an added resistance to the expiratory effort caused a phase-shift in the cough patterns, similarly to that seen in COPD patients. Due to the cannula, the spectra of patients having laryngotomy had a lot of high harmonics. They also had peaks nearly identical to that of bronchitic patients because they suffered from serious chronic bronchitis. It was found that by examination the cough spectra of series of voluntary cough sound signals it was possible to distinguish healthy volunteers from patients. This examination would therefore be useful for screening of bronchial diseases.

Effect of intracerebrally injected aminophylline, vinpocetinum, vasoactive intestinal peptide and onion extract on breathing pattern of rats.

Aminophylline or VIP (Vasoactive Intestinal Peptide) given ip. or iv. have marked bronchodilatory effects. The onion extracts protect guinea pigs as well as human patients against allergen-induced bronchial spasms (Dorsch et al.). Recently it has been shown that lipophilic components of onions seem to be responsible for the antiasthmatic effects. The purpose of this study was to investigate the effect of intracerebrally injected aminophylline (3 microM), Vinpocetinum (0.1 mg/kg), VIP (5 micrograms) and onion oils (30 microliters of extracts) on the respiratory center and on the resistance of lower airways of rats. The following respiratory parameters were evaluated: respiratory rate (RR), tidal volume (VT), mean inspiratory flow (Vin), respiratory minute volume (VE), and dynamic lung resistance (R). Respiratory rate was increased and values of all the other parameters were decreased after aminophylline treatment. VIP increased the tidal volume, minute ventilation and the respiratory drive. After injection of onion extracts the respiratory rate and the dynamic lung resistance decreased, but the tidal volume increased. The beneficial effects of onion oil are manifested not only peripherally acting on bronchial smooth muscle but via the reflexogenic pathways.

A model for experimental asthma: provocation in guinea-pigs immunized with Bordetella pertussis.

Guinea-pigs were sensitized with killed Bordetella pertussis (3.85 X 10(11) cells . kg-1). The presence of the immediate type of immune response was verified by passive cutaneous anaphylaxis (PCA). In anaesthetized spontaneously-breathing guinea-pigs respiration rate, tidal volume, minute ventilation, dynamic lung resistance and dynamic lung elastance were estimated on the basis of airflow velocity and pressure in the oesophagus. After provocation by a single intravenous injection of the killed cells, respiratory frequency, elastance and resistance increased but tidal volume decreased. The preventive effects of aminophylline and clemastine (50 microns . kg-1, i.v.) were observed. B. pertussis not only alters adrenergic function but provocation in B. pertussis-sensitized guinea-pigs seems to be a good model for bronchial asthma.