Mucociliary function during experimentally induced rhinovirus infection in man

Advances in the Prophylaxis of Respiratory Infections by the Nasal and the Oromucosal Route: Relevance to the Fight with the SARS-CoV-2 Pandemic

In this time of COVID-19 pandemic, the strategies for prevention of the infection are a primary concern. Looking more globally on the subject and acknowledging the high degree of misuse of protective face masks from the population, we focused this review on alternative pharmaceutical developments eligible for self-defense against respiratory infections. In particular, the attention herein is directed to the nasal and oromucosal formulations intended to boost the local immunity, neutralize or mechanically “trap” the pathogens at the site of entry (nose or mouth). The current work presents a critical review of the contemporary methods of immune- and chemoprophylaxis and their suitability and applicability in topical mucosal dosage forms for SARS-CoV-2 prophylaxis.

First contact: the role of respiratory cilia in host-pathogen interactions in the airways

Respiratory cilia are the driving force of the mucociliary escalator, working in conjunction with secreted airway mucus to clear inhaled debris and pathogens from the conducting airways. Respiratory cilia are also one of the first contact points between host and inhaled pathogens. Impaired ciliary function is a common pathological feature in patients with chronic airway diseases, increasing susceptibility to respiratory infections. Common respiratory pathogens, including viruses, bacteria, and fungi, have been shown to target cilia and/or ciliated airway epithelial cells, resulting in a disruption of mucociliary clearance that may facilitate host infection. Despite being an integral component of airway innate immunity, the role of respiratory cilia and their clinical significance during airway infections are still poorly understood. This review examines the expression, structure, and function of respiratory cilia during pathogenic infection of the airways. This review also discusses specific known points of interaction of bacteria, fungi, and viruses with respiratory cilia function. The emerging biological functions of motile cilia relating to intracellular signaling and their potential immunoregulatory roles during infection will also be discussed.

Nasopharyngeal Reservoir of Bacterial Otitis Media and Sinusitis Pathogens in Adults during Wellness and Viral Respiratory Illness

Background

The carriage rate of pathogenic bacteria in the nasopharynx (NP) was determined using three separate techniques for obtaining samples.

Methods

The NP of 99 healthy adults was sampled with (1) nasal swab, (2) oral swab, and (3) nasal aspiration; 49 adults with common cold were sampled with an oral swab and nasal aspiration. Three selective agars were used to detect Streptococcus pneumoniae, Hemophilus influenzae, and Moraxella catarrhalis.

Results

Seventy-three percent of healthy adults and 74% of cold sufferers had at least one pathogen detected in the NP. Detection rates were 65% (oral NP swab), 38% (catheter aspiration), and 28% (nasal swab; p < 0.001). Carriage rates for S. pneumoniae, M. catarrhalis, and H. influenzae were 45, 33, and 30%, respectively. Both a nasal and an oral sample were required for optimal detection.

Conclusion

Bacterial pathogens were present in the NP of three-quarters of adults during wellness and during colds.

Allergic and Nonallergic Rhinitis. Classification and Pathogenesis: Part II. Nonallergic Rhinitis

Part I of this review classified and defined the causes of chronic rhinitis, describing in detail the etiology and pathophysiology of allergic rhinitis. Part II focuses on the nonallergic (non-IgE) causes of chronic rhinitis, concentrating on their clinical presentations, differential characteristics, and known or speculative pathophysiology. A comprehensive understanding of the allergic and nonallergic conditions associated with symptomatic rhinitis should aid the clinician in the appropriate diagnosis and treatment of patients with chronic rhinitis.

The Response of the Nasal Airway, Middle Ear, and Eustachian Tube to Experimental Rhinovirus Infection

This paper describes the longitudinal changes in nasal patency, mucociliary clearance rate, eustachian tube function, and middle ear pressure in a group of 40 volunteers infected with rhinovirus type 39. Thirty-two (80%) of the volunteers were judged to have had a cold based on the modified Jackson criteria. Common symptoms included malaise, nasal congestion, rhinorrhea, and sneezing that began on the day after challenge and peaked in intensity on days 3–5. Nasal patency evaluated by active posterior rhinomanometry and mucociliary clearance rate evaluated by the dyed sacharrin technique were significantly decreased following challenge. For nasal patency the effect was primarily limited to days 2–8 postchallenge, while abnormalities in clearance rate were documented for as long as 18 days postchallenge. A 50% increased incidence of abnormal eustachian tube function and a 30% increased incidence of abnormal middle ear pressures were observed for days 2–7 postchallenge with a gradual return to baseline by day 16. For mucociliary clearance, eustachian tube function, and middle ear pressure, but not nasal patency, these abnormalities were more pronounced in patients with a symptomatic cold. These results show that changes in nasal physiology resulting from a rhinovirus infection can be objectively quantified and that the resulting pathophysiology extends to anatomically contiguous structures such as the eustachian tube and middle ear.

Rhinovirus-specific antibody responses in preschool children with acute wheeze reflect severity of respiratory symptoms

BACKGROUND

Some children with rhinovirus (RV) infections wheeze, but it is unknown whether this is due to more virulent strains of virus or differences in host immune responses. The aim of this study was to investigate the RV species-specific antibody responses measured at a follow-up visit in preschool children in relation to reported time with respiratory symptoms and the presence of different RV species during an acute episode of wheeze.

METHOD

Nasopharyngeal swabs and blood samples were taken among 120 preschool children (<4 years of age) at an acute episode of wheeze and at a follow-up visit (median 11 weeks later). Nested PCR was used to detect different RV strains, and serum levels of IgG₁ against purified recombinant VP1 proteins from representatives of the three RV species (RV-A, RV-B, and RV-C) were measured by ELISA.

RESULTS

Rhinovirus was detected in 74% (n = 80/108) of the children at the acute visit, and RV-C was the most common subtype (n = 59/80, 74%). An increase in RV-specific IgG₁ was seen in 61% (n = 73) of the children at follow-up, most frequently against RV-A (n = 61/73, 86%) irrespective of the RV strains detected by PCR. Increases in RV-specific IgG₁ against RV-A or against RV-A and RV-C were significantly associated with more respiratory symptoms (p = 0.03, p = 0.007).

CONCLUSION

Antibody response to recombinant RV VP1 proteins was associated with longer time with respiratory symptoms.

Bacterial pathogens in the nasopharynx, nasal cavity, and osteomeatal complex during wellness and viral infection

BACKGROUND

Viral sinusitis can precede acute bacterial sinusitis, but the influence of viral infection on bacterial colonization is unclear. The objective of this study was to evaluate the presence of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in the osteomeatal complex (OMC), nasal cavity, and nasopharynx in adults during wellness and viral upper respiratory illness (URI).

METHODS

Subjects were recruited for the study during wellness and at the time of acute viral rhinosinusitis. Swab cultures were obtained from the OMC, nasal cavity, and the nasopharynx. Swab eluates were inoculated on selective agars to detect S. pneumoniae, H. influenzae, and M. catarrhalis.

RESULTS

The study included 237 subjects, 100 adults with URI and 137 well adults. Positive culture results were found for any site in 70% (n = 70) of ill subjects and 64% (n = 88) of well subjects (p = 0.393). Of the 91 OMC cultures, positive cultures were over five times more likely to be found in ill subjects than in well subjects (31% versus 8%; p = 0.010). The nasal cavity cultures were positively statistically significant more often in ill subjects versus well subjects (39% versus 25%; p = 0.022). The overall nasopharyngeal cultures did not show a statistically significant difference (65% versus 60%; odds ratio, 1.2; p = 0.461). S. pneumoniae was positively cultured in at least one site in 15% of ill subjects and 31% of well subjects (p = 0.006). H. influenzae was positively cultured in at least one site in 45% of ill subjects and 31% of well subjects (p = 0.027). M. catarrhalis was positively cultured in at least one site in 42% of ill subjects and 27% of well subjects (p = 0.018).

CONCLUSION

This study defines the carriage rates of the three most common bacterial pathogens for acute sinusitis in the nasopharynx, nasal cavity, and OMC during illness and in the healthy state.

Bacteria in the nose of young adults during wellness and rhinovirus colds: detection by culture and microarray methods in 100 nasal lavage specimens

BACKGROUND

Patients  with  viral respiratory infections/viral rhinitis/common colds are often treated with antibiotic; however, there is little information on whether or how bacterial microbiota in the nose and nasopharynx might influence the course of viral illnesses.

METHODS

To initiate investigation of possible interaction between viral respiratory illness and microbiota of the nose/nasopharynx, we used microarray technology to examine 100 nasal lavage fluid (NLF) samples for bacterial species and recorded the bacterial titer of culturable bacteria. Rhinovirus illnesses were induced by self-inoculation using the "finger to nose or eye natural transmission route" in 10 otherwise healthy young adults. NLF samples were collected during wellness and at specific time points following experimental rhinovirus inoculation.

RESULTS

The rhinovirus infection rate was 70%. There were no consistent changes in the prevalence of different bacterial species determined by microarray and bacterial titer by culture methods during rhinovirus infection. The bacterial profile in NLF samples showed high variability between volunteers but low variability in multiple NLFs obtained before and following infection from the same volunteer. Streptococcus epidermidis/coagulase-negative staphylococcus (CNS) were identified in all 10 subjects. One or more bacterial sinus/otitis pathogens were identified by microarray in 6 of the 10 volunteers. The microarray identified a few bacteria not included in traditional bacterial cultures.

CONCLUSION

Our pilot study showed that each of the 10 volunteers had a unique bacterial profile in the nose by microarray analysis and that bacterial load did not change during experimental rhinovirus colds. Larger scale studies are warranted.

Bacterial pathogens of acute sinusitis in the osteomeatal complex during common colds and wellness

BACKGROUND

Pathogenic bacteria have been cultured from the osteomeatal complex (OMC) in one-third of adults with apparent acute bacterial sinusitis; however, it is not known whether bacteria are present in the OMC during uncomplicated viral colds in adults.

METHODS

Adult volunteers were recruited for a study during wellness and at the time of acute common cold. Swab cultures were obtained from the OMC and from the nasopharynx by 2 routes (through the nose and through the mouth). Swab eluates were inoculated on selective agars to detect S. pneumoniae, H. influenzae, and M. catarrhalis.

RESULTS

Bacterial pathogens were detected in the OMC more frequently during common colds than during wellness (31% vs 8%, p < 0.008). Pathogens detected in the OMC were always present in the nasopharynx of the subject.

CONCLUSION

Bacterial pathogens are present in the OMC in a subgroup of adult patients with uncomplicated upper respiratory illness/common cold. The nasopharynx appears to be the reservoir for bacterial pathogens in the OMC.

The effect of antiallergic intranasal formulations on ciliary beat frequency of human nasal epithelium in vitro

The nasal mucociliary clearance is an important defense mechanism of the upper respiratory tract. It is known to be influenced by many pharmacologic substances. We investigated the effects of three topical intranasal antiallergic formulations containing disodium cromoglycate (DNCG), dimethindene maleate (DMM), and azelastine-HCL (AZL) on nasal ciliary beat frequency (CBF) in vitro. Nasal ciliated cells were harvested from 16 healthy volunteers. Cells were diluted 1:10 in culture medium and incubated with a placebo formulation (PLAC), containing 0.022% benzalkonium chloride, which was part of all formulations, a registered 2% formulation of DNCG, a 0.1% formulation of DMM, and a registered 0.1% formulation of AZL. After an incubation period of 20 min, CBF was registered by a photoelectric measurement device. Under control conditions (CONTROL), CBF was 11.4 +/- 1.3 Hz. PLAC reduced CBF to 9.7 +/- 2.3 Hz (NS). DNCG reduced CBF to 9.7 +/- 2 Hz (NS). DMM reduced CBF to 7.2 +/- 1.7 Hz (P < or = 0.05 vs CONTROL, NS vs PLAC), and AZL reduced CBF to 0.9 +/- 1.8 Hz (P < or = 0.001 vs CONTROL, P < or = 0.001 vs DNCG, P < or = 0.001 vs PLAC). In conclusion, a possible influence of antiallergic intranasal formulations on nasal ciliary function has to be considered in clinical application.

Nasal mucociliary clearance as a factor in nasal drug delivery

The nasal mucociliary clearance system transports the mucus layer that covers the nasal epithelium towards the nasopharynx by ciliary beating. Its function is to protect the respiratory system from damage by inhaled substances. Impairment of nasal mucociliary clearance can result in diseases of the upper airways. Therefore, it is important to study the effects of drugs and drug excipients on nasal mucociliary clearance. A large number of methods are used to assess mucociliary clearance. These methods study the effects of drug and excipients on the mucociliary system in vitro or in vivo in animals and humans. In some cases, the results of different in vitro and in vivo measurements do not correlate well. In vitro methods, especially ciliary beat frequency measurements, have been demonstrated to be valuable tools for toxicity screening. However, in vivo studies are essential to confirm the safety of nasal drug formulations. Nasal mucociliary clearance also has implications for nasal drug absorption. Drugs are cleared rapidly from the nasal cavity after intranasal administration, resulting in fast systemic drug absorption. Several approaches are discussed to increase the residence time of drug formulations in the nasal cavity, resulting in improved nasal drug absorption. However, more experimental evidence is needed to support the conclusion that this improved absorption is caused by a longer residence time of the nasal drug formulation.

Prechallenge antibodies: moderators of infection rate, signs, and symptoms in adults experimentally challenged with rhinovirus type 39

This study determined the influence of serum neutralizing antibody titers on infection rate, symptom manifestations, and provoked signs and pathophysiologies in adults experimentally exposed to rhinovirus type 39 (RV-39). Antibody status was determined for 151 healthy volunteers who were then cloistered in a hotel for 6 days. At the end of the first cloister day, the volunteers were challenged with RV-39 in a median tissue culture infective dose of 100. On each of the 6 days, a nasal examination was performed, symptoms were scored, and objective tests of nasal mucociliary function, nasal airway patency, secretion production, and middle ear pressures were completed. Both subjects and investigators were blinded to the prechallenge serum homotypic antibody titers of the subjects. Four subjects presented with a wild virus and were excluded from the analysis. Of the 147 included subjects, prechallenge serum antibody titers to RV-39 were low (under 2) in 56 subjects, intermediate (2 to 8) in 51 subjects, and high (above 16) in 40 subjects. The high-titer group was significantly different from the low-titer group with respect to viral shedding, symptom load, subjective extent of illness, and secretion production, as well as in the frequency of subjects with abnormal nasal mucociliary clearance and positive middle ear pressures. The study results document that for experimental RV-39 exposure, high levels of homotypic serum neutralizing antibody titers are associated with protection from infection and a lessened degree of disease expression, but not with a reduction of otologic complications.

Mucociliary clearance abnormalities in the HIV-infected patient: a precursor to acute sinusitis

An increasing number of patients with human immunodeficiency virus (HIV) suffer from acute infectious sinusitis, and many suffer recurrent episodes at a higher rate than their non-HIV counterparts. This study investigates a mechanism underlying the increased incidence of sinusitis, that of prolonged mucociliary transport time (MTT). Nasal mucociliary clearance was examined in 30 HIV-infected patients and 30 matched, non-HIV controls using a nasal saccharin transport test. MTTs for the study group and the controls were 11.9 +/- 5.9 minutes and 7.4 +/- 3.7 minutes, respectively. This difference attained statistical significance (P < .05). Study group patients with a history of sinusitis had a mean MTT of 13.7 +/- 6.8 minutes. Those with complaints of "new onset" nasal obstruction since HIV conversion had a mean MTT of 13.5 +/- 6.8 minutes. Statistical significance (P < .05) was found comparing these times to controls, as well as to study patients without these symptoms. These data support an inherent delay of mucociliary clearance in HIV-infected patients which is chronic, possibly irreversible, and, in association with nasal obstruction, represents a major mechanism of both the high acute and recurrent sinusitis rate in this population. The cause of the mucociliary delay is still unclear and needs to be further investigated.

Ultrastructural changes in human nasal cilia caused by the common cold and recovery of ciliated epithelium

Changes in the ultrastructure of human respiratory cilia caused by the common cold were studied in 12 patients. The nasal mucosa was studied three times: on the first or second day after the beginning of symptoms, and 1 week and 3 weeks after the first biopsy. The damage was most severe at 1 week. The most remarkable finding was the loss of cilia and ciliated cells. However, the ultrastructure was usually normal, without any increase in tubular anomalies, as compared with the normal material of the previous reports. Three weeks after the beginning of the disease the number of cilia and ciliated cells had increased to nearly normal. However, as a sign of regeneration, immature short cilia (0.7 to 2.5 microns in length) were often seen. The ciliary orientation was uniform, dynein arms were normal, and there was no increase in the number of tubular anomalies. The results suggest that the impaired mucociliary function during viral infections is due to the loss of cilia and ciliated cells, rather than to ultrastructural anomalies in the cilia. The development of tubular anomalies and random ciliary orientation may require more extensive exposure to factors affecting ciliary function.

Viruses as precipitants of asthma symptoms. II. Physiology and mechanisms

The upper and lower airways have complimentary roles in the ultimate object of supplying the body with oxygen whilst removing waste products of metabolism. Pathology in one area may trigger a response in another, the physiology of which, in the case of virus-induced asthma exacerbations remains poorly characterized. Viral infection of the upper airways by common cold viruses frequently triggers a response in the lower airways leading to prolonged morbidity, especially in subjects with significant pre-existing airway disease. The induction or amplification of BHR may be an important mechanism whereby asthmatic symptoms are produced although the cellular and tissue events or reflex mechanisms activated by viral illnesses and underlying BHR changes are poorly defined and may be dependent on the type and the severity of infection. Children and asthmatics tend to develop frequent colds setting in motion a sequence of events culminating in airway obstruction and symptoms of wheezing, coughing and chest tightness. This may reflect independent inflammatory changes caused by a simply additive effect of viral damage to the mucosa superimposed upon pre-existing allergic inflammation (Fig. 1). Few if any symptoms will develop in normal subjects with a mild cold whereas significant symptoms may ensue if the cold is severe and induces marked lower airway swelling, secretions and smooth muscle contraction; pathology to which children who have small calibre airways may be particularly susceptible. In asthmatics even a mild cold frequently induces exacerbation of symptoms, while serious life-threatening asthma attacks may occur associated with a severe cold. Some studies have suggested that this effect is not only additive but also synergistic and brought about by release of the mediators already present in increased quantities, the induction of IgE synthesis, or by the potentiation of neural and epithelial damage. The combined effect of both asthma and viruses may thus be amplified and result in a sustained and refractory period of airway obstruction, severe symptoms and unstable asthma. As most hospital admissions for asthma occur over the winter months and soon after the start of the school terms [115], spread of viruses through the community to susceptible individuals may be the single most important cause of sustained exacerbations of asthma. Definition of the pathological and physiological mechanisms involved will lead to better understanding and may thus provide a basis for prevention and the development of effective forms of treatment for virus-induced asthma.

Newcastle disease viral infection in chicken nasal turbinate and maxillary sinus

Newcastle disease virus (NDV) B strain was inoculated intranasally and intrasinusly into unanesthetized chicken which were maintained on a standard commercial mash chicken diet until the age of 21 days after hatch. The lesions induced by NDV following intranasal inoculation usually produced a selective destruction of significant portions of the inner surface of the turbinate scroll, but sinus lesions, though sometimes present in NDV infection, were not common. The chicken sinus was infected by intrasinus inoculation. These results were supported by the amount of virus and mucociliary transport time in the turbinate and sinus. It is suggested that mucus hypersecretion of ostial gland and/or mucociliary activity in the sinus be one of the most important factors in protecting against chicken sinus infection.

The nasal mucociliary clearance: relevance to nasal drug delivery

Mucociliary clearance is an important physiological defense mechanism of the respiratory tract to protect the body against noxious inhaled materials. This process is responsible for the rapid clearance of nasally administered drugs from the nasal cavity to the nasopharynx, thereby interfering with the absorption of drugs following intranasal application. This review describes the mucociliary system and the methods used for its characterization. Examples are given of the effects of drugs and additives on its functioning. Further, possible approaches are presented for increasing the residence time of drugs in the nasal cavity, thereby improving intranasal drug delivery.

Nasal transit time in normal subjects and pathologic conditions

A radionuclide method using Tc-99m was used to measure the nasal transit time in 43 patients, including normal smokers and nonsmokers and those with various nasal or paranasal pathologies. The technique described was slightly modified from that already in use in various centers in order to enable more precise measurement. Measurement of transit time of a droplet of Tc-99m phytate on the nasal mucosa appears to differentiate patients with immotile cilia syndrome from normal controls. A positive test, however, can occur also in smokers and in patients with other nasal and paranasal problems. The test is reproducible, cost-effective, and noninvasive, enabling the clinician to make a more appropriate selection of patients needing further investigation.

Nasal mucociliary clearance in Sjögren's syndrome. Dissociation in flow between sol and gel layers

Nasal mucociliary clearance was measured with two methods in 8 patients with Sjögren's syndrome and in 6 normal subjects. The movement of two different tracers placed 1.5 cm posterior to the inferior turbinate tip was measured respectively. The transport rate of a 500 microns anion resin particle tagged with 99mTc was measured. The clearance of 10 microliters saline labelled with 99mTc was monitored and the clearance rate was calculated. Whereas the measurement with the particle method revealed the lowered transport rate in Sjögren's syndrome, measurement with the saline method did not reveal any difference in clearance rate between the two groups. Since the former method measures the transport of particle in the gel phase (the outer mucous layer) and the latter measures the clearance of both gel and sol (periciliary fluid) layers, it is postulated that there is a dissociation of flow between sol and gel layers in Sjögren's syndrome.

Effect of prostaglandin E2 and bacterial endotoxin on the rate of dye transport in the eustachian tube of the chinchilla

To determine the effects of various biologic agents on the rate of fluid transport in the eustachian tube of the chinchilla, we have established an in situ method of measuring dye transport in which the bulla remains intact. The normal rate of dye transport from an injection site in the superior bulla to the nasopharyngeal orifice of the eustachian tube was 130 +/- 10 seconds. Inhibition of ciliary activity with the local anesthetic bupivacaine resulted in a saturable delay of transport (greater than 15 minutes), while exposure to the beta-adrenergic stimulator isoproterenol caused a significant increase in transport rate (79 +/- 7 seconds). Two inflammatory mediators commonly found in chronic middle ear effusions were also tested for their effect on fluid transport by the mucociliary apparatus. Bacterial endotoxin reduced transport rates at high concentrations, while prostaglandin E2 had no effect at any concentration tested.

Functional and morphological pathology of the nasal mucosa after x-ray irradiation

In our present study we examined the pathology of the nasal mucociliary system after x-ray irradiation in an animal model namely the rabbit. A reduced ciliary activity was observed immediately after the irradiation and did not show any recovery during our observation. No ciliary activity was seen in the nasal mucosa 8 weeks after the irradiation. Morphologically, hypersecretion of goblet cells was observed immediately after irradiation. Cytoplasmic vacuolation and nuclear pyknosis of ciliated cells started after irradiation, and sloughing of ciliated cells was observed for up to 3 weeks. Epithelial metaplasia started from 4 weeks, and no cilia were seen in the nasal mucosa and the surface of the epithelium was covered with flat squamous cells. Our present study shows that x-ray irradiation has serious influence on the function and structure of the nasal mucociliary system and that recovery from degeneration due to x-ray irradiation cannot be expected within several weeks.

Recovery process of tracheal mucosa of guinea pigs exposed to isopropyl alcohol

The toxicity of isopropyl alcohol (IPA) on the tracheal mucosa was studied experimentally with special reference to the recovery process of the organ. The results showed that 400 ppm IPA has an acute effect on the mucociliary system in the tracheal mucosa, and that recovery from such degeneration can occur in 2 weeks. When functional and morphological damage was induced by a higher level (5500 ppm) of IPA, recovery did not occur in 2 weeks. The conclusion is that the present allowable level of IPA is reasonable from the viewpoint of the effects of short-term exposure to IPA on the tracheal mucosa. In addition, a higher level of IPA exposure has longer-term effects on the tracheal mucosa, and workers exposed to such a higher level of IPA vapor should be given careful otolaryngological follow-up observations.

Effects of irradiation on the ciliary activity of the eustachian tube and the middle ear mucosa

Radiation-induced changes in the ciliary activity of the eustachian tube and middle ear mucosa were investigated in a laboratory model. Twenty-four guinea pigs were sacrificed, and a mucosa at the bony portion of each eustachian tube and from the middle ear proximal and distal to the tube were sampled. The mucosal samples were irradiated with 200 kV hard X-rays discretely at a dosage level of 0.5-30.0 Gy, and the induced changes in ciliary activity were expressed as a percent deviation from baseline levels before irradiation. The present study demonstrates that the cilia of the eustachian tube and middle ear mucosa show different reactions to irradiation according to their tympanic locations.

Ciliary activity in patients with nasal allergies

Nasal allergy is a disease ensuing from type-I allergic reactions in the nasal cavity. A correct understanding of this process requires further investigation of the non-allergic pathology present. In the allergic state, the function of the nasal cilia is considered to be involved in the invasion of allergens into the nasal mucosa, and may also be involved with the manifestation and progression of the disease produced. In the present study, we examined the ciliary activity of the nasal mucosa of 35 patients with nasal allergies by using the photo-electric method of Ohashi and Nakai to better understand the non-allergic pathologies present. The nasal cilia of four healthy volunteers served as controls. In addition, a multivalent analysis was made according to quantifying theory I in order to define the effects of various factors on ciliary activity in the nasal mucosa during the allergic state. The following results were found in our present study. Ciliary activity was observed in 32 of 35 patients with nasal allergy. The mean value of the ciliary activity in these patients was 498 +/- 195 beats/min, while that of the normal controls was 753 +/- 46 beats/min. The ciliary activity in the nasal mucosa in the allergic state declined as the morbid period was prolonged; this decline in ciliary activity was relatively great in cases of perennial allergies aggravated by season-specific allergens.

Chronic rhinitis

The author provides a well-detailed update on chronic rhinitis, the most common disease of the respiratory tract. Discussed are the anatomy and physiology of the nose, investigation of the patient, etiology, and treatment, including avoidance of provoking factors, pharmacologic therapy, and immunotherapy.

Light and scanning electron microscopy of nasal biopsy material from patients with naturally acquired common colds

As our knowledge of the histopathology of common colds is very limited, we have undertaken a blind quantitative examination by scanning electron microscopy and light microscopy of 56 nasal biopsies, taken from 29 volunteers with naturally acquired colds. In agreement with earlier reports we found evidence of sloughing of epithelial cells, but in contrast to in vitro experiments, this did not result in a destruction of the epithelial lining, which by and large remained continuous, with structurally normal cell borders. There was a significant increase in the number of neutrophils, both in epithelium and in lamina propria, already on the 2nd day of the disease, and the hypothesis is advanced that the virus infection itself is the cause of the local neutrophilia. The only other abnormality demonstrated was an increased number of extracellular erythrocytes in the acute stage. The histological picture was not suggestive of an involvement of epithelial mast cells in the inflammation.

Nasal mucociliary clearance under various conditions

We applied the tagged-particle method or the saccharin method or both to the nasal mucociliary clearance. There was no effect of ageing on the transport time of saccharin in control subjects of ages under 60, and 70% of control subjects of ages more than 60 had the same transport time as that obtained in younger control subjects. The significant inverse correlation between the mucociliary transport rates with the particle method and the transport time with the saccharin method were established in control subjects, but not, however, in patients with chronic sinusitis. The mucociliary transport rates were measured under non-physiologic conditions of the nose: laryngectomy, chronic sinusitis, Sjögren's syndrome, and Kartagener's syndrome.

Nasal secretion from normal subjects

A new method of collection of nasal secretion, by dilution with condensed mositure of the exhaled air, is described. This method may be defined as a sefl-administered nasal lavage. The method permits quantitative determination of pH, relative viscosity, and electrolyte and protein composition. Concentrations of sodium, potassium, calcium, total protein, IgA, IgG, IgM, secretory compoenent and polysaccharide are reported for normal subjects. Significant correlations were noted between the relative viscosity and variables: dry weight, total protein and calcium.

Induced rhinovirus infection under controlled exposure to sulfur dioxide

The interaction between short-term sulfur dioxide (SO2) exposure and experimentally induced rhinovirus infection was studied in thirty-two volunteers divided into two groups balanced with respect to age, antibody levels, and nasal mucus flow rates. One group was exposed to SO2 exposure at the threshold limit value (TLV) of 5 ppm during 4 hours; the other group served as controls exposed to pollution-free air under the same conditions. The SO2 exposure caused a 50% decrease in nasal mucus flow rate in the anterior parts of the nose, but there was no difference in the number of colds which developed in the two groups. The group exposed to SO2 had fewer symptoms and a possibly shorter incubation period (P = .06), and virus shedding was at a lower level but more persistent than in the control group. No differences were found in antibody response. The rhinovirus infection in the control group caused a gradual decrease in nasal mucus flow rate starting 2 days after the virus instillation, and after 5 days the rate was less than half its initial value. For future experiments on the interaction between airborne pollutants and rhinovirus infections, a virus challenge by aerosol inhalation is recommended. Our study supports an earlier observation that growth of influenza virus in the nasal cavity of mice was inhibited by exposure to SO2 concentrations of 6 or 20 ppm.

Mucociliary transport in trachea of patients with cystic fibrosis

Mucociliary tracheal transport rates were measured in 20 patients with cystic fibrosis, in whom these rates ranged from 0 to 12.8 mm/min. The patients were divided into 3 roughly equal groups on the basis of their transport rates. (1) Those in whom no abnormality in mucociliary transport was detected in the trachea; (2) those in whom normal transport rates were measured but in whom abnormalities such as cessation, or reversal of bolus movement were observed; (3) those in whom no normal transport rates were observed. In the first group the rates were similar to those observed in a population of healthy adults. These normal rates were observed in some patients who had a productive cough. The mean mucociliary tracheal transport rate increased with increasing maximum midexpiratory flow. Those patients with a low Shwachman score and poor arterial oxygen tension tended to fall into groups 2 and 3. In the ciliary dyskinesia assay in rabbit trachea the serum from the patients with the higher transport rates tended to initiate more rapid discharge of material from the epithelium and ciliary dyskinesia.