Biomedical subjects

R Eccles

Publications and source records attributed to R Eccles.

125 records · Page 7Linked to original sources

PubMedDate not supplied

Pathophysiology of nasal symptoms.

Symptoms are perceived by the patient and all nasal symptoms must eventually relate to stimulation of sensory nerves or some change in the activity of the CNS. Although it is the symptoms that are of prime importance to the patient, the role of sensory nerves and psychology in the generation and perception of symptoms has been relatively neglected compared to the large amount of research on inflammatory mediators. This paper discusses how physical and chemical changes in the nasal epithelium result in the generation of inflammatory mediators that are responsible for symptoms. Inflammatory mediators can cause symptoms in three ways. (1) By having direct action on glands and blood vessels to cause glandular secretion, vasodilation, increased vascular permeability, and transudation of a plasma exudate. (2) By stimulation of sensory nerve endings to cause reflex glandular secretion, sneezing, and sensations such as itching, irritation, pain, and pressure. (3) By effects on the central nervous system to cause, headache, fever, tiredness, and mood changes.

Humans↗

PubMedDate not supplied

An evaluation of nasal response following different treatment regimes of oxymetazoline with reference to rebound congestion.

This was a randomized, double-blind vehicle controlled study aimed at investigating the effects on nasal function of 7 days treatment with the topical decongestant oxymetazoline (0.05% w/v). Fifty healthy volunteers took part in the study and these were randomly allocated to three treatment groups (i) daily oxymetazoline (b.i.d. 150 microliters per nostril) (ii) intermittent oxymetazoline, with oxymetazoline being substituted for vehicle at the morning doses on days 1, 3, and 7; and (iii) daily vehicle (b.i.d. 150 microliters per nostril). The nasal airway was assessed by measurement of nasal airway resistance (NAR) using posterior rhinomanometry, subjective scaling of nasal patency by means of a visual analogue scale (VAS), and clinical visual examination. On days 1, 2, 3, and 7, NAR and VAS measurements were obtained before the morning dose and up to 6 hours after dosing; clinical visual examinations were also performed before dosing on these days. NAR and VAS measurements were also made following withdrawal of treatment on Days 8 and 9. Nonparametric analysis of the results showed that therapeutic tolerance to oxymetazoline did not develop over the 7-day treatment period, and visual examination of the nasal mucosa failed to find significant evidence of rhinitis. Evidence of rebound nasal congestion was found following 3 days of oxymetazoline treatment, with baseline NAR within the daily and intermittent oxymetazoline groups being significantly greater on Day 3 compared to Day 1 (p < 0.05). However, there was a trend toward increasing baseline NAR in the vehicle group over the course of the study, suggesting that the vehicle may have contributed to the rebound congestion. Following the withdrawal of treatments, only the intermittent oxymetazoline group had significantly higher NAR on Days 8 and 9 compared to Day 1 (p < 0.05). Subjective VAS measurements generally followed trends in NAR.

Adolescent↗

PubMedDate not supplied

The effects of nasal massage of the "yingxiang" acupuncture point on nasal airway resistance and sensation of nasal airflow in patients with nasal congestion associated with acute upper respiratory tract infection.

The aim of our study was to determine whether nasal massage of the "yingxiang" acupuncture point in patients with nasal congestion had any effect on nasal airway resistance (NAR) measured by posterior rhinomanometry and sensation of nasal airflow measured on a visual analog scale (VAS). Twenty patients were randomized into two groups; one group self massaged the yingxiang point for 30 seconds, while the other group acted as control group without nasal massage. NAR and VAS were measured at baseline, and at 2 and 10 minutes after massage. At the end of the study, patients were asked to score any change in their nasal congestion. There was no statistically significant difference between the two groups in percentage change in NAR or VAS from baseline at any time during the study, although the massage group showed trends toward decongestion and relief from congestion. At the end of the study, more patients in the massage group than the control group felt their nasal congestion was improved (p < 0.005). It is interesting that all three measures (NAR, VAS, and end question) showed that the nasal massage group had greater relief from nasal congestion than the control group. The results of this study, when taken together, indicate that nasal massage may provide some relief from nasal congestion and that further studies involving a larger patient population are warranted to determine whether nasal massage has a significant effect on NAR.

Acupuncture Points↗

PubMedDate not supplied

Changes in human nasal resistance associated with exercise, hyperventilation and rebreathing.

The nasal resistance to airflow determined in four subjects for periods of up to 7 hr. Cyclic changes in the resistance of each nasal passage were demonstrated in 13 or 24 experiments. After exercise on the cycle ergometer the total nasal resistance decreased and this change in nasal resistance was found to be directly related to the work rate. After oral rebreathing, the total nasal resistance decreased, and after hyperventilation the total nasal resistance increased. These changes in resistance are believed to be caused by changes in arterial pCO2 and mediated by the autonomic innervation of the nasal vasculature.

Adult↗

PubMedDate not supplied

The central rhythm of the nasal cycle.

The resistance to air flow of each nasal passage was recorded in 2 subjects over a period of 7 days. The cyclical changes in nasal resistance observed were very regular, with a consistent pattern apparent over the period of study. The regular changes in nasal resistance recorded under laboratory conditions may be directly related to changes in activity of an autonomic centre in the brain.

Adult↗

PubMedDate not supplied

The domestic pig as an experimental animal for studies on the nasal cycle.

The resistance to air flow of each nasal passage in the anaesthetized pig was determined by pumping air through the nose and measuring pressure changes in nasal cannulae. A nasal cycle was observed in the marjority of the pigs. Three types of change in nasal resistance were observed and their possible causes are discussed. Section of the right cervical sympathetic nerve abolished the cyclic changes in nasal resistance of both nasal passages. The method described may prove useful in studying the physiology of the nasal cycle.

Airway Resistance↗

PubMedDate not supplied

Nasal vasomotor oscillations in the cat associated with the respiratory rhythm.

Asymmetrical nasal vasomotor oscillations mediated via the cervical sympathetic nerve have been observed in the spontaneously breathing cat. The vasomotor activity persists after abolition of spontaneous respiration with a neuromotor relaxant agent indicating that the vasomotor activity originates in the respiratory areas of the brain and is not due to any of the mechanical effects of respiration. The nasal vasomotor activity is abolished on hyperventilation indicating that it may be driven from a central respiratory oscillator. The vasomotor activity exhibits a reciprocal activity with oscillations in sympathetic activity alternating from one nasal passage to the other and this may be due to a direct relationship with a nasal cycle in the cat.

Animals↗

PubMedDate not supplied

The effects of camphor, eucalyptus and menthol vapour on nasal resistance to airflow and nasal sensation.

The effects of five minutes exposure to camphor, eucalyptus or menthol vapour on nasal resistance to airflow and nasal sensation of airflow were compared with the effects of exercise on the nose. Inhalation of camphor, eucalyptus or menthol had no effect on nasal resistance to airflow but the majority of subjects reported a cold sensation in the nose with the sensation of improved airflow. Exercise caused a decrease in nasal resistance but did not induce any nasal sensation of cold or improved airflow. The results indicate that camphor, eucalyptus and menthol stimulate cold receptors in the nose. The clinical significance of nasal sensation of airflow is discussed.

Adult↗

PubMedDate not supplied

A study of the synthesis and inactivation of prostaglandin E by pig nasal mucosa.

Prostaglandins of the E series have been shown to be more potent than adrenaline as nasal decongestants. We now present evidence that prostaglandins of the E series (PGE) can be synthesised and inactivated by the nasal mucosa of the pig. This study demonstrates that PGE may be formed by pieces of pig nasal mucosa in vitro and that PGE formation by the nasal mucosa is inhibited by indomethacin. The nasal mucosa was also shown to contain 15-hydroxy prostaglandin dehydrogenase activity and this enzyme is involved in the inactivation of PGE. The findings of this study may help towards a better understanding of the role of PGE in nasal physiology and nasal disease.

Animals↗

PubMedDate not supplied

Reciprocal changes in nasal resistance to airflow caused by pressure applied to the axilla.

The resistance to airflow of each nasal passage was measured using active, posterior, rhinomanometry. Application of pressure to the axilla for 15 min by means of a wooden crutch caused a reciprocal change in nasal resistance with an ipsilateral increase and a contralateral decrease in resistance. The results are discussed in terms of reflex changes in sympathetic tone to the nasal venous erectile tissue.

Adolescent↗

PubMedDate not supplied

The effects of nasal anaesthesia upon nasal sensation of airflow.

The effect of nasal anaesthesia upon the sensation of nasal airflow and activity of menthol was investigated in 25 subjects using a visual analogue scale. Nasal anaesthesia was shown to decrease the sensation of nasal airflow, and also decrease the action of menthol in enhancing the sensation of nasal airflow. These differences were shown to be highly significant p less than 0.001. Physiological mechanisms responsible for conveying the subjective appreciation of a nasal airflow stimulus are discussed, and also the site and nature of the sensory nerve endings involved.

Administration, Intranasal↗

PubMedDate not supplied

Olfactory and trigeminal thresholds and nasal resistance to airflow.

Nasal congestion associated with the common cold or allergy is associated with a decreased sensitivity of the sense of smell. This study was designed to detect any relationship between nasal resistance to airflow and the ability to detect odors presented to the nose. In particular we were interested to determine if the asymmetrical nasal resistance to airflow associated with the nasal cycle influenced nasal thresholds to menthol which is detected by trigeminal nerves and vanillin which is detected by olfactory nerves. Nasal resistance to airflow and the thresholds for L-menthol and vanillin were measured for each nasal passage in 17 normal volunteer subjects. Nasal resistance to airflow was asymmetrical due to the nasal cycle with a resistance on the high side of 0.94 +/- 0.15 Pa/cm3 s (mean +/- S.E. n = 17). and 0.48 +/- 0.04 Pa/cm3 s on the low side. The range of unilateral nasal resistances varied from 0.31-2.55 Pa/cm3 s. Despite these variations in nasal resistance to airflow no relationship was found between nasal resistance to airflow and thresholds for menthol or vanillin. Since threshold and nasal resistance are not related in normal subjects this may indicate that it is not the level of nasal congestion that affects the sense of smell in nasal infection and allergy, but some other factor related to the inflammatory response of the nasal mucosa.

Adult↗

PubMedDate not supplied

The relationship between nasalance and nasal resistance to airflow.

The relationship between nasal airway resistance and nasalance in healthy volunteers and in subjects suffering from symptoms of acute rhinitis was investigated. A non-invasive objective measure of nasalance using the Nasometer (Kay Electronics) was used and an inverse correlation between airway resistance and nasalance was found (r = 0.67, r2 = 0.46, p less than 0.0001). The effect of a topical nasal decongestant on nasal airway resistance and nasalance was investigated, and significant changes were seen both in resistance and nasalance (p less than 0.0001) with a correlation in the changes seen in both parameters (r = 0.82, r2 = 0.66, p less than 0.0001). The measure of nasalance may be useful in assessing various forms of nasal treatment including nasal, adenoidal and palatal surgery. The measurement of nasalance is well tolerated by subjects of all ages and is particularly useful in subjects with high nasal resistance where rhinomanometry tends to be unstable.

Acute Disease↗

PubMedDate not supplied

A new clinical measure of external laryngeal size which predicts the fundamental frequency of the larynx.

A method for accurately predicting the average fundamental frequency of the larynx from an external measurement of laryngeal size has been developed. In 21 human cadaveric dissections we have demonstrated that the external height of the larynx (measured from the lower border of the cricoid cartilage to the upper border of the thyroid notch) was significantly correlated to the length of the membranous vocal fold (r = 0.94, p less than 0.001). This same external measure of laryngeal size in 115 healthy volunteers was found to be related to their voice fundamental frequency. Significant differences were found between males and females with respect to both laryngeal size (p less than 0.001) and voice fundamental frequency (p less than 0.001). A strong correlation between the external laryngeal measurement and speaking fundamental frequency was found with an overall correlation coefficient for both sexes of 0.8 (p less than 0.001). Using this external measurement, it may be possible to accurately predict the fundamental frequency in males and females. It is proposed that such a measurement could be used to identify various laryngeal diseases and also serve as a basis for corrective treatment in various voice disorders.

Aged↗

PubMedDate not supplied

Use of a portable spirometer for studies on the nasal cycle.

Studies based on the nasal cycle are difficult because multiple measurements of nasal patency need to be made over many hours. There is a great need for a simple portable instrument that can be used away from the clinical laboratory for studies on the nasal cycle. Our aim was to investigate the usefulness of a small portable spirometer in studying the nasal cycle. The Mir Spirobank spirometer was fitted with a nasal adapter to measure the volume of air expired from each nasal passage during a slow vital capacity (VC). The spirometer was used to measure the fractions of the slow VC volume of air expired through the right and left nasal passage in turn. Hourly measurements were made over a 5-hour period in six healthy volunteers. The spirometry measurements of the volume of air expired from each nasal passage were compared with nasal conductance of each nasal passage (airflow at 75 Pa) obtained by posterior rhinomanometry. The spirometer was found easy to use by both the investigator and the patients. Simple regression analysis of the spirometer and rhinomanometer measures of airflow partitioning found a correlation coefficient of r = 0.827 (p < 0.0001: n = 36). These results indicate that the partitioning of nasal expired volume measured by spirometry is directly comparable with partitioning of nasal airflow obtained with rhinomanometry. Spirometry has considerable advantages over rhinomanometry for studies on the nasal cycle because of portability and ease of use.

Adult↗

PubMedDate not supplied

Experimental studies on nasal sensation of airflow.

Objective and subjective measurements of nasal airflow were made before and after inhalation of vanilla and a commercial mixture of aromatics used to treat nasal stuffiness. These substances had no effect on nasal resistance to airflow but caused significant changes in the subjective sensation of nasal airflow. The use of a visual numerical scale for the assessment of nasal sensation of airflow is discussed in terms of its significance as regards quantifying changes in nasal sensation of airflow before and after nasal surgery.

Adolescent↗

PubMedDate not supplied

Effect of inspiratory and expiratory air flow on congestion and decongestion in the nasal cycle.

The role of the inspiratory and expiratory airflow through nostrils during the process of breathing in the reflex reciprocal congestion and decongestion of the nasal cycle was examined in this study. Air flow through each nostril was measured separately in male subjects before and after four types of breathing practices for 15 min each consisting of (1) inspiration through the patent nostril and expiration through the congested nostril, (2) inspiration through congested nostril and expiration through patent nostril, (3) inspiration through both nostrils and expiration through mouth and (4) inspiration through mouth and expiration through both nostrils. The breathing practices had no effect on the congested nostril but caused decrease in air flow through the patent nostril, indicating congestion. It is suggested that the inspiratory and expiratory air flow through the nostrils caused reflex congestion of the patent nostril. The stimuli arising from the nasal mucosa due to air flow during breathing may form the basis for the reflex reciprocal congestion and decongestion of nostrils in the nasal cycle.

Adult↗