Nasal resistance

Ohki, M., Hasegawa, M., Kurita, N., and Watanabe, I. (1987). Effects of exercise on nasal resistance and nasal blood flow. Acta Otolaryngol. (Stockh) 104, 328-333. 

The objective analysis was made with the nasal provocation test with the allergens, the nasal resistance measured by static and dynamic rhinomanometry at a preset pressure of 150 Pa in accordance with the recommendations of the International Standardization Committee [9], and MCT. 

An example of a drug separated by preparative HPLC is cetirizine dihydrochloride, a racemic drug that is a second generation antihistamine Hi receptor antagonist. Studies on the effect of racemic and R (25) and S-Cetirizine (26) on nasal resistance indicated that both racemic and the R-enantiomer had similar activity. The racemate and R-enantiomer inhibit histamine and induced an increase in nasal resistance, thus indicating the antihistaminic properties of R-Cetirizine (45). TheiS-enantio-... 

Marked ethnic differences in infant mortahty and respiratory morbidity have been reported (130). Prematnrely dehvered Afro-Caribbean infants are less likely to develop the respiratory distress syndrome (RDS) than white infants of similar gestational age (131), which snggests that the respiratory system is either more matnre or that airway function is enhanced in black preterm infants (132). Some of these differences may be attributed to differences in nasal anatomy, since the lower total airway resistance found in Afro-Caribbean infants when compared with Caucasian infants of similar age and weight (101) was accounted for by their lower nasal resistance (23). Such differences would be expected to influence both breathing patterns and the distribution of inhaled aerosols. 

Stocks J, Godfrey S. Nasal resistance during infancy. Respir Physiol 1978 34 233-246. 

Menthol is often thought of as a decongestant, but this effect is a sensory illusion. Burrow et al. (1983) and Eccles et al. (1988) showed that there was no change in nasal resistance to air ow during inhalation of menthol, although the sensation of nasal air ow was enhanced. In the former experiment, 1,8-cineole and camphor were also shown to enhance the sensation of air ow but to a lesser extent than menthol. 

In a double-blind, randomized trial, subjects suffering from the common cold were given lozenges containing 11 mg of menthol. Posterior rhinomanometry could detect no change in nasal resistance to air ow after 10 min however, there were signi cant changes in the nasal sensation of air ow (Eccles et al, 1990). 

Burrow, A., Eccles, R., Jones, A. S. 1983. The effects of camphor, eucalyptus and menthol vapours on nasal resistance to air ow and nasal sensation. aOtolar n ol. 96 157-161. 

Eccles, R., M.S. Jawad, and S. Morris, 1990. The effects of oral administration of (-)-menthol on nasal resistance to airflow and nasal sensation of airflow in subjects suffering from nasal congestion associated with the common cold. J. Pharm. Pharmacol., 42 652-654. 

Nasal vasculature may offer some insight into this question, though research to date has been equivocal. Nasal turbinate vessels can be classified as either capacitance vessels or resistive vessels. Capacitance vessels appear to vasodilate in response to infection while resistance vessels appear to respond to cold stimuli by vasoconstriction. Buccal vascular structures also respond to thermal stimuli but appear to respond principally to cutaneous stimuli. How pharyngeal and tracheobronchial submucosal vessels react to thermal stimuli is not known, though cold-induced asthma is believed to result from broncho-spasms caused by susceptible bronchial smooth muscle responding to exposure to cold dry air.- This asthmatic response suggests an inadequate vascular response to surface cooling. 

Mupirocin is employed topically in eradicating nasal and skin carriage of staphylococci, including methicilhn-resistantS to/)/ , colonization. 

For resistant cases of nasal obstruction, evaluate the need for topical decongestants, oral decongestants, or short-course oral steroids. 

The goals of treatment for ABRS are to eradicate bacteria and prevent serious sequelae. Specific aims are to relieve symptoms, normalize the nasal environment, use antibiotics when appropriate, select effective antibiotics that minimize resistance, and prevent development of chronic disease or complications. 

With higher concentrations than those mentioned above, animals exhibit, in addition to myosis, the following symptoms salivation, muscular weakness, loss of muscular co-ordination, gasping, diarrhoea and finally cessation of respiration. There is intense constriction of the bronchioles and the immediate cause of death is asphyxia. Respiration ceases before the heart stops beating. The L.c. 50 s for rats and for mice for a 10 min. exposure are respectively 0-36 and 0-44 mg./l. Air saturated with D.F.P. at ordinary temperatures contains about 8 mg./l. and this will kill mice within 1 min. During exposures for a limited time (e.g. 5 min.), rabbits appear to be more resistant to the inhaled vapour of D.F.P. than are other animals. It appears that the peculiar nasal structure of the rabbit is responsible for its great resistance. 

Figure 9.1 Relationship between the transepithelial electrical resistance (TEER) value of the passage-cultured human nasal epithelial cell layer and permeability of 14C-mannitol (o, passage-2 A, passage-3 , passage-4) and budesonide ( , passage-2 , passage-3 , passage-4). (Data from Ref. [40]).

Figure 9.3 Changes in transepithelial electrical resistance (TEER) of human nasal epithelial cell layers grown under LCC ( ) versus AIC (A) conditions. Each data point represents the mean SD of three determinations. (Data from Ref. [46]).

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