[Apoptosis lymphocytes T and B in adenoid]

Apoptosis is a physiological form of cell death, which plays an important role in embryogenesis, cellular homeostasis, tissue atrophy and removal of tumor and mutated cells. Apoptosis of T and B lymphocytes is a fundamental process regulating antigen receptor selection during T cell maturation and homeostasis of the immune system. It also plays a key role in elimination of autoreactive lymphocytes. There are two major signaling pathways of apoptosis: the death receptor pathway and intrinsic pathway the mitochondrial pathway.

Uptake of microparticles into the epithelium of human nasopharyngeal lymphoid tissue

The M cells of nasopharyngeal lymphoid tissue (NALT) have been considered to play an important role for vaccine delivery systems in humans. A number of investigations have reported particle uptake data in NALT of rodents. However, there have been no reports indicating any involvement of the nasopharyngeal lymphoid tissue in human vaccination. In the present study, we investigated whether the epithelium of human adenoid tissues might incorporate fluorescent microparticles using electron and fluorescent microscopy. The dissected adenoid tissues were incubated with various sizes and concentrations of fluorescent microparticles for 120 min at 37 degrees C. Furthermore, the effect of surface coatings of microparticles with cations on the uptake into the epithelium of adenoid tissues was investigated. Transmission electron microscopy revealed that microparticles were taken up by the M cells of human nasopharyngeal lymphoid tissues. The NALT-M cells showed greater uptake of the smallest particles, 0.2 microm in diameter, than those of 0.5, 1.0, or 2.0 microm diameter. It was also revealed that surface coatings with poly-L: -lysin or chitosan resulted in efficient uptake into the NALT. These results indicate that nasal administration of antigenic microparticles, which were coated with cationic materials, probably leads to a useful method of transnasal vaccination against respiratory and intestinal infections in humans.

Human nasopharyngeal-associated lymphoreticular tissues. Functional analysis of subepithelial and intraepithelial B and T cells from adenoids and tonsils

Subepithelial and intraepithelial lymphocytes of human adenoids and tonsils were characterized and directly compared to determine the potential contribution of these tissues to mucosal and systemic immune responses. The distribution of T and B cell subsets, cytokine patterns, and antibody (Ab) isotype profiles were similar for adenoids and tonsils. Both tissues contained predominantly B cells ( approximately 65%), approximately 5% macrophages, and 30% CD3(+) T cells. The T cells were primarily of the CD4(+) subset ( approximately 80%). Tonsillar intraepithelial lymphocytes were also enriched in B cells. The analysis of dispersed cells revealed a higher frequency of cells secreting IgG than IgA and the predominant Ig subclass profiles were IgG1 > IgG3 and IgA1 > IgA2, respectively. In situ analysis also revealed higher numbers of IgG- than IgA-positive cells. These IgG-positive cells were present in the epithelium and in the subepithelial zones of both tonsils and adenoids. Mitogen-triggered T cells from tonsils and adenoids produced both Th1- and Th2-type cytokines, clearly exhibiting their pluripotentiality for support of cell-mediated and Ab responses. Interestingly, antigen-specific T cells produced interferon-gamma and lower levels of interleukin-5. These results suggest that adenoids and tonsils of the nasopharyngeal-associated lymphoreticular tissues represent a distinct component of the mucosal-associated lymphoreticular tissues with features of both systemic and mucosal compartments.

Effects on the ciliated epithelium of protein D-producing and -nonproducing nontypeable Haemophilus influenzae in nasopharyngeal tissue cultures

A pair of isogenic, nontypeable Haemophilus influenzae strains, one expressing protein D and the other protein D-negative, was compared in their ability to cause damage in a human nasopharyngeal tissue culture model. Damage was assessed by measuring the ciliary beat frequency (CBF) of tissue specimens at 12 h intervals. Cultures inoculated with H. influenzae manifested a decrease in CBF beginning after 12 h, with a maximum decrease after 36 h. The impairment of ciliary function by the protein D-expressing strain was significantly greater than that caused by the protein D-negative mutant (P<.01). Tissue specimens examined by scanning and transmission electron microscopy after 24 h appeared normal. After 48 h of incubation, the protein D-expressing strain caused a significant loss of cilia. These findings suggest that protein D is involved in the pathogenesis of upper respiratory tract infections due to nontypeable H. influenzae, probably by enhancing functional and morphological damage to cilia.

Signal transduction pathways in modulation of ciliary beat frequency by methacholine

The release of endogenous neurotransmitters plays an important role in the airway mucosal defense system. We studied the in vitro effect of methacholine, a beta-methyl ester of acetylcholine, on the ciliary beat frequency (CBF) of human adenoid explants and its mechanism of action. Tissue explants were cultured at 35 degrees C and covered with 1.0 mL of culture medium: minimum essential Eagle's medium (MEM) containing L-arginine (1.2 x 10(-3) mol/L). Methacholine was added to the cultured tissue at concentrations of 10(-10), 10(-8), and 10(-6) mol/L. The CBF was determined by phase contrast microscopy and microphotometry. Methacholine increased CBF in a dose-dependent manner with a maximum increase of 23.0% +/- 1.8% (p < .001). Atropine (10(-6) mol/L) significantly inhibited the ciliostimulatory effects of methacholine (p < .0007). The role of endogenous prostaglandins in methacholine-induced ciliostimulation was determined by treating specimens with a cyclooxygenase inhibitor (diclofenac sodium). Diclofenac (10(-6) mol/L) significantly inhibited the ciliostimulatory effects of methacholine (p < .0007). To determine if nitric oxide (NO) acts as an intermediary in ciliostimulation by methacholine, endogenous NO production was inhibited by treating specimens with an L-arginine analog, NG-nitro-L-arginine methyl ester (L-NAME), prior to addition of methacholine. L-NAME (10(-6) mol/L) inhibited the effects of methacholine in L-arginine-free MEM (p < .008), and this inhibition was reversed by L-arginine (10(-3) mol/L). To further examine the actions of NO in methacholine-induced ciliostimulation, a cyclic guanosine 3'5'-monophosphate (cGMP) kinase inhibitor (KT-5823) was used, prior to the addition of methacholine. KT-5823 (10(-6) mol/L) significantly inhibited the effects of methacholine (p < .0001). Ciliostimulation by methacholine in human upper airway mucosa involves both prostaglandin and NO second messengers and activation of a cGMP-dependent kinase.

Dual signal transduction mechanisms modulate ciliary beat frequency in upper airway epithelium

This study investigated the effects of methacholine and terbutaline on the ciliary beat frequency (CBF) of upper airway epithelium. The CBF of cultured human adenoid explants was measured using microphotometry. Methacholine (10(-6) M) and terbutaline (10(-6)M) increased CBF a maximum of 23.0 +/- 1.8% (P < 0.001) and 16.5 +/- 2.3% (P < 0.001). Inhibition of endogenous nitric oxide (NO) production by nitro-L-arginine methyl ester (L-NAME) (10(-6) M) abolished the effects of methacholine in L-arginine-free medium (P < 0.008). This inhibition was reversed by addition of L-arginine. There was no inhibition of terbutaline-induced ciliostimulation by L-NAME (P < 0.5). KT-5823 (10(-6)M), a guanosine 3',5'-cyclic monophosphate (cGMP) kinase inhibitor, significantly inhibited the effects of methacholine (P < 0.0001), but not terbutaline (P > 0.15). H-89 (10(-6) M), a cAMP kinase inhibitor, significantly inhibited terbutaline-induced ciliostimulation (P < 0.0001), but not methacholine-induced ciliostimulation (P > 0.05). Diclofenac (10(-6) M), a cyclooxygenase inhibitor, significantly inhibited the effects of methacholine (P < 0.0007) but had no effect on terbutaline-induced ciliostimulation (P > 0.05). These findings suggest that the CBF of upper airway epithelium is modulated through at least two distinct pathways. The beta 2-adrenoceptor produces ciliary stimulation by a pathway involving increased intracellular cAMP levels, while the muscarinic receptor increases CBF by a mechanism involving production of prostaglandins, NO, and cGMP.

The functional role of the adenoids in speech

Illustrative cases are presented showing a variety of interrelationships between the adenoids and the activity of the velopharyngeal valve in speech. The cases presented were selected from a group of 1000 patients referred because of suspected velopharyngeal diseases. When appropriate, complete velopharyngeal assessment was made including otolaryngological speech and hearing examination, polysomnography, nasendoscopy, multiview videofluoroscopy and cephalometry. New observations are described which further elucidate the mechanism by which the adenoids may change the mechanism of velopharyngeal valving and consequently speech patterns. In conclusion, procedures involving the adenoids and tonsils and surgical correction of velopharyngeal valve abnormalities to improve respiratory function must be performed in a manner which ensures preservation of normal speech activity. Similarly, surgical correction of velopharyngeal valve abnormalities to improve speech activity must preserve its respiratory function. The velopharyngeal valve and the adeno-tonsils must be considered together whenever diagnosis and a therapeutic intervention of either of them is considered. A clinical method for patient evaluation, patient management and the development of a rational therapeutic approach is presented.

Effects of prostaglandins D2 and E2 on ciliary beat frequency of human upper respiratory cilia in vitro

Diminished mucociliary transport can occur in a type-I (Ig-E mediated) allergic reaction. We determined the effects of the allergy mediators prostaglandin D2 (PGD2) and prostaglandin E2 (PGE2) on the ciliary beat frequency (CBF) of human upper respiratory cilia in vitro. Human adenoid tissue was used as the source for ciliated epithelium. CBF was measured by a computerized photo-electric method. PGD2 (10(-8)-10(-5) M, n = 7) showed no statistically significant effect on CBF. PGE2 (10(-9)-10(-6) M, n = 10) caused a significant dose-dependent stimulation, with a maximum of 37% (ANOVA, p < 0.001). Thus prostaglandins D2 and E2 do not exert a direct negative influence on ciliary activity, which could account for a decrease in mucociliary transport. The stimulating effect of PGE2 may be relevant in promoting mucociliary clearance in vivo.

Histamine and leukotriene C4 effects on in vitro ciliary beat frequency of human upper respiratory cilia

Decreased mucociliary transport can occur in patients with type I (IgE-mediated) allergic rhinitis or allergic asthma. This study investigated if the allergic mediators histamine and leukotriene C4 (LTC4) could interfere with ciliary beat frequency (CBF) of in vitro human upper respiratory cilia and eventually result in decreased mucociliary transport. Ciliated epithelium of human adenoid tissue was used in the experiments and CBF was determined using a computer-assisted photoelectric method. Histamine in concentrations of 10(-6) - 10(-3) M (n = 12) and LTC4 as 10(-9) - 10(-6) M solutions (n = 10) showed no statistically significant dose-dependent effect on CBF in vitro.

Effect of substance P on ciliary beat frequency in human adenoid explants

This study investigated the direct effects of substance P (SP) on ciliary beat frequency of human upper airway mucosa. Human adenoid explant tissue was maintained in serum free culture media, MCDB153. Ciliated epithelial cells were observed with phase-contrast microscopy and ciliary activity was measured using a photometric technique. Oscillations in transmitted light caused by ciliary beating were recorded and modal ciliary beat frequency was determined by fast Fourier transformation. Specimens were treated with SP at concentrations of 10(-4), 10(-5), 10(-6), and 10(-7) mol/L and with equal molar solutions of SP and (D-Pro2,D-Trp7,9)-SP, a SP antagonist. Substance P was found to increase ciliary beat frequency in a dose-dependent manner with a maximum increase of 12.1%. This effect was not seen with solutions containing (D-Pro2,D-Trp7,9)-SP. This suggests that SP exerts a direct stimulatory effect on ciliated cells of the upper airway. Because SP is known to be released in the upper airway in response to chemical irritation, it is presumed that the stimulatory effect of SP on mucosal cells provides a protective mechanism against inhaled irritants.

Influence of levocabastine suspension on ciliary beat frequency and mucociliary clearance

The effects of levocabastine, a new fast-acting, highly potent H1-antagonist, on nasal ciliary epithelial function were investigated in an in vitro and in vivo study. In the in vitro study, a suspension of levocabastine in Locke-Ringer solution was applied to 10 bioptic specimens of ciliated human adenoid tissue. Each specimen was exposed to the test solution for 60 min. Ciliary beat frequency (CBF) was recorded with a photoelectric recording device at 10-min intervals. There were small, insignificant decreases in CBF, which were minimal compared to that observed with ciliotoxic agents. In the in vivo study, 8 healthy volunteers were given, intranasally, one droplet of the levocabastine suspension. Mucociliary transit time (MTT) was measured by placing a saccharin particle drenched in indigo carmine in the nose just below the top of the concha and measuring the time until appearance of the dye in the pharyngeal cavity. No statistically significant differences were found in the MTT before and after application of the levocabastine suspension. The studies thus indicate that nasally administered levocabastine does not interfere with ciliary beat frequency and mucociliary function.

Functional architecture of the nasopharyngeal tonsil

The exact architecture of the normal nasopharyngeal tonsil remains obscure because most histopathologic investigations have been based on surgically removed adenoids. We compared enlarged adenoids and normal nasopharyngeal tonsils under both light and electron microscopes. The marked features of clinically enlarged adenoids were a large extension of the reticular epithelium and increased germinal centers. A tendency toward increased stratified squamous epithelium and decreased ciliated epithelium was apparent in enlarged adenoids, possibly due to inflammatory conditions. One type of nonciliated cell seemed to transport foreign material into underlying lymphocytes, as do the M cells of gut-associated lymphoid tissue. This type of nonciliated cell was rarely found in the extended reticular epithelium of enlarged adenoids. These findings suggest a disturbance of the antigen-trapping system and surface protections in adenoidal enlargement.

The role of adenoids in the development of normal speech following palate repair

The controversy surrounding the various approaches to palate repair continues unabated. Issues which have been studied relative to the development of normal speech following palate repair have included surgical technique and the timing of surgery. However, regardless of the various refinements in surgery, a percentage of children require secondary surgery to resolve velopharyngeal insufficiency. To date, other factors which might be responsible for the development of normal speech have been ignored. The purpose of this report is to discuss the importance of the relative size of the adenoids in relation to the success or failure of primary palatoplasty. Velopharyngeal valving in noncleft (normal) children was also observed. Eight hundred fifty children with nonsyndromic clefts and 138 children with syndromic clefts were analyzed for speech results postpalatoplasty relative to adenoid size. One hundred normal children were also studied. The data suggest a strongly positive correlation between the incidence of hypernasal resonance postpalatoplasty and relative adenoid size in the cleft children. Velar-adenoidal closure was consistently observed in both the cleft and normal children.

Adenoid hypertrophy and nasal mucociliary clearance in children. A morphological and functional study

The authors have studied nasal mucociliary function and adenoid surface characteristics in a group of 86 children, aged between 4 and 10 years, divided in two groups according to the presence or absence of clinical, instrumental and röntgenographic signs of nasal obstruction due to hypertrophied adenoids. Each group was divided into 3 age-related subgroups (group I: 4-5 years; group II: 6-7 years; group III: 8-10 years). A population of normal adults was chosen both for functional and ultrastructural characteristics. Nasal mucociliary clearance velocity values were evaluated by means of the saccharine method and the surface characteristics of the adenoid tissue by means of scanning electron microscopy. The data obtained show that the nasal mucociliary function is generally reduced in children but, while in the group with poorly developed adenoids an early and progressive improvement can be observed, the children with severely hypertrophied adenoids show an impaired function up to 10 years, without age-related improvements. At almost 10 years, children with poorly developed adenoids reach normal adult clearance values. These functional data can be related to the surface characteristics of adenoid tissue. In fact, while poorly developed adenoids are characterized by a compact layer of ciliated cells, severely hypertrophied adenoids are characterized by a metaplasic epithelium, with almost complete loss of cilia. Such findings, which are probably due to the inflammatory events frequently complicating adenoid hypertrophy, could explain, together with the obstructive effects, the impairment of the nasal mucociliary clearance in childhood.

Correlation between the sensitivity of the ciliary beat frequency of human adenoid tissue and chicken embryo tracheas for some drugs

The effects of benzalkonium chloride, chlorbutol,xylometazoline and naphazoline on the ciliary beat frequency of human adenoids and chicken embryo tracheas have been determined and compared. Chlorbutol 0.5% appeared to arrest ciliary motion in both tissues within 5 minutes. Rinsing with Locke Ringer solution (LR) restored the ciliary motion almost completely in both cases. Benzalkonium chloride 0.006% +EDTA 0.1% decreased the ciliary beat frequency 35% for the human tissues and 50% for the chicken tissues after a contact of 20 minutes. In both cases the frequency hardly changed after rinsing with LR. Naphazoline nitrate 0.1% and xylometazoline HCl 0.05% have reversible effects on the ciliary beat frequency of both human adenoids and chicken embryo tracheas. Cilia of human adenoids appeared to be more sensitive for xylometazoline than for naphazoline; whereas cilia of chicken embryo tracheas were more affected by naphazoline than by xylometazoline. The results with human adenoids and chicken embryo tracheas show a correlation (correlation coeff. = 0.82, p less than 0.005). In the initial response the differences in sensitivity to preservatives and drugs were in many cases statistically significant, but the final effects were similar.

Tonsils and adenoids: why the dilemma?

Enlarged tonsils and adenoids have been implicated in dentofacial development and in the developing facial configuration. The growth pattern and the role of these lymphoid tissues are controversial, as are the benefits to be gained by their surgical removel. The diagnosis of enlarged tonsils and adenoids and of mouth breathing is not based on well-defined criteria.

The mucociliary activity of the upper respiratory tract. I. A method for use in experimental studies on human material

A method for standardized recordings of the mucociliary activity of the mucosa in the human respiratory tract is described. Nasal polyps, adenoid vegetations and biopsy material from maxillary sinuses have been used for preliminary in vitro experiments. The dependence of the mucociliary activity on oxygen supply from the surrounding air is emphasized. The influence of varying gas mixtures on the mucociliary activity can be thoroughly studied. The method is also applicable for in vivo recordings in the operating theatre during Luc Caldwell operations. A combination of in vivo and in vitro studies is under way in order to elucidate the aetiology, treatment, and prognosis of diseases of the upper respiratory tract.

Adenoidectomy in relation to otitis media

Past studies of the efficacy of adenoidectomy in the management of children with otitis media have been inconclusive due to significant limitations in experimental design. At the Children's Hospital of Pittsburgh, the effect of adenoidectomy on the outcome of otitis media is currently being studied in a prospective manner. An attempt is being made to document and to control those factors cited as lacking in the previous studies. This report describes the techniques for assessment of nasal and Eustachian tube function and for the completeness of adenoidectomy.

Patterns of velopharyngeal closure in subjects with repaired cleft palate and normal speech: a multi-view videofluoroscopic analysis

Thirty subjects with repaired palatal clefts and normal speech ranging in age from 2 to 12 years were examined in multiple videofluoroscopic projections in order to assess velopharyngeal closure in three dimensions. The following points became evident from the results of this study: 1. All 30 subjects exhibited contact between the superior border of the velum and the adenoid mass in the nasopharynx. Often, a sharp levator eminance was not formed due to the small space between the velum at rest and the adenoids. Thus, there was little room for the velum to elevate. 2. All 30 subjects showed good localized medial movement of the LAPW at the approximate plane of the hard palate. 3. 10 out of 30 subjects, 33%, had a Passavant's Ridge during speech. All 10 of these subjects utilized the ridge as a point of closure, as well as the adenoids. 4. The observed patterns of closure were consistent across varied consonant utterances. 5. The mechanism of velopharyngel closure in this group of subjects is essentially the same as for normal adult speakers and differs only anatomically due to a lack of verticle head growth in children. Thus, in spite of the presence of adenoids and the lack of verticle head development, the basic sphincteric mechanism of velopharyngeal colsure is utilized in these subjects.