Scanning electron microscopic studies of the human nasal mucosa in normal persons and in patients with perennial rhinitis. II. Secretion

Hyperactivation of sympathetic nerves drives depletion of melanocyte stem cells

Empirical and anecdotal evidence have associated stress with accelerated hair greying (formation of unpigmented hairs)^1,2, but the scientific evidence linking the two is scant. Here, we report that acute stress leads to hair greying through fast depletion of melanocyte stem cells (MeSCs). Combining adrenalectomy, denervation, chemogenetics^3,4, cell ablation, and MeSC-specific adrenergic receptor knockout, we found that stress-induced MeSC loss is independent of immune attack or adrenal stress hormones. Rather, hair greying results from activation of the sympathetic nerves that innervate the MeSC niche. Upon stress, sympathetic nerve activation leads to burst release of the neurotransmitter norepinephrine, which drives quiescent MeSCs into rapid proliferation, followed by differentiation, migration, and permanent depletion from the niche. Transient suppression of MeSC proliferation prevents stress-induced hair greying. Our studies demonstrate that acute stress-induced neuronal activity can drive rapid and permanent loss of somatic stem cells, and illustrate an example in which somatic stem cell maintenance is directly influenced by the overall physiological state of the organism.

RT-PCR cytokine study in patients with allergic rhinitis

Allergic rhinitis is an inflammatory reaction of the nasal mucosa, in consequence of an IgE mediated hypersensitive reaction to inhaling allergens, involving different mediators and cytokine cells.

AIM

The purpose of this study was to evaluate the transcriptions for IL-4, IL-5, IL-8 and IFN-gama, particularly important in the nasal allergy process, especially IL-4 and IL-5. For this study we decided to evaluate atopic patients who were free from allergic crises, with the purpose of knowing the cytokine expressions during this period.

MATERIALS AND METHODS

Another prospective and transversal study was carried out, selecting 30 patients, 13 of these patients were pauci-symptomatic and 17 were non atopic. The groups were selected by means of a medical interview, an otolaryngologic clinical exam and allergy skin tests - Prick Test. The cytokines were investigated in fragments of the nasal mucosa, using RT-PCR - chosen because it has good reproducibility and specificity.

RESULTS

IL-5, IL-8, IFN-gama cytokine values were kept homogeneous in relation to the control group. Only IL-4 presented significant statistic differences.

CONCLUSION

Asymptomatic patients with allergic rhinitis presented with normalization of cytokine expression in the nasal mucosa, with exception of IL-4.

Análise de citocinas pela RT-PCR em pacientes com rinite alérgica

Rinite alérgica é uma doença que decorre de um processo inflamatório da mucosa nasal conseqüente à reação de hipersensibilidade a alérgenos inalatórios e, eventualmente, alimentares. É mediada por IgE, envolvendo diferentes células, mediadores e citocinas. OBJETIVO: Avaliar as transcrições para as seguintes citocinas: IL-4, IL-5, IL-8 e IFN-gama, particularmente importantes no processo alérgico nasal, principalmente IL-4 e IL-5. Neste estudo, optou-se por avaliar os pacientes atópicos fora das crises alérgicas, com a finalidade de se conhecer as expressões das citocinas neste período. MATERIAL E MÉTODO: Realizou-se um estudo transversal e prospectivo, selecionando-se 30 pacientes, sendo 13 pacientes portadores de rinite alérgica paucissintomáticos e 17 pacientes não-atópicos. Os grupos foram selecionados através da história, do exame clínico otorrinolaringológico e do teste alérgico cutâneo - Prick Test. O perfil das citocinas foi pesquisado nos fragmentos de mucosa nasal, através da RT-PCR semiquantitativa, escolhida por apresentar boa reprodutibilidade e especificidade, utilizando-se como referência o gene da Beta-actina. RESULTADOS: Os valores de IL-5, IL-8, IFN-gama mantiveram-se homogêneos em relação ao grupo controle. A IL-4 apresentou diferença com significância estatística. CONCLUSÃO: Os pacientes alérgicos paucissintomáticos apresentaram normalização da expressão das citocinas na mucosa nasal à exceção de IL-4.

Development of a murine model of chronic rhinosinusitis

OBJECTIVE

The aim of this study was to develop a mouse model of chronic eosinophilic rhinosinusitis.

STUDY DESIGN

Mice were sensitized to Aspergillis fumigatus (Af) extract by intraperitoneal injection. The animals subsequently received nasal challenges with Af extract 3 times per week for 12 weeks. Sinonasal complexes were studied histologically by the study otolaryngologists and pathologists to characterize the inflammatory response.

SETTING

Animal care facility at an academic institution.

RESULTS

A chronic eosinophilic inflammatory response was evoked in all study animals. Statistical analysis was performed for inflammation, secretory cell hyperplasia, mast cells, and eosinophils. There were very significant differences (P<0.0005) between control and study mice in all categories.

CONCLUSION

Prolonged nasal challenge of Af extract creates an inflammatory response in murine nasal mucosa that mimics human chronic eosinophilic rhinosinusitis.

SIGNIFICANCE

A murine model for chronic rhinosinusitis is reported that may facilitate future investigations into disease pathophysiology.

EBM RATING

B-2.

A role for neutrophils in intermittent allergic rhinitis

OBJECTIVE

In patients with intermittent allergic rhinitis, allergen challenge may induce both early- and late-phase responses. The aim of this study was to examine the correlation between inflammatory cells in the nasal lavage fluid and clinical parameters following pollen challenge.

MATERIAL AND METHODS

Nasal lavage fluids were obtained from 29 patients with intermittent allergic rhinitis before and 1 and 6 h after allergen provocation, representing the control, early and late phases, respectively. Symptom and rhinoscopic scores were registered on the same occasions. Inflammatory cells were determined in the nasal fluid.

RESULTS

The early phase was characterized by increased symptom scores, rhinoscopic signs of oedema and secretion and neutrophilia. In the late phase, symptom scores had diminished, but the signs of ongoing secretion remained. Both the total nasal symptom score and the secretion score correlated with the number of neutrophils in lavage fluids at 1 h. The eosinophil count did not increase during the early or late phases.

CONCLUSION

A single allergen provocation induces an early-phase response dominated by neutrophils, with secretion being the only clinical sign remaining during the late phase. The increase in neutrophil numbers correlated with the registration of secretory symptoms. The presented data indicate a role for neutrophils in intermittent allergic rhinitis and their relation with secretory parameters makes it intriguing to speculate that neutrophils may function as promoters of nasal secretion.

Pituitary adenylate cyclase-activating polypeptide, effects in the human nose

BACKGROUND

Pituitary adenylate cyclase-activating peptide (PACAP) is a neuropeptide with strong vaso- and bronchodilator capacity. There is recent evidence that PACAP decreases the release of proinflammatory cytokines and we have previously shown that PACAP inhibits neutrophil chemotaxis in vitro, but little is known about the effects of PACAP in human upper and lower airways.

OBJECTIVE

To investigate the effects of PACAP in the human upper respiratory tract focusing on vasodilatation/nasal airway resistance (NAR), neutrophil recruitment, plasma extravasation and endogenous production of IL-1-related mediators.

METHODS

Surgical specimens from five patients (aged 19-55 years), obtained in conjunction with nasal surgery, were used for immunohistochemical localization of PACAP in the nasal mucosa. In seven, healthy, non-allergic, non-smoking subjects (aged 19-45 years), NAR was measured with rhinomanometry. Nasal lavage was performed, before and after intranasal application of PACAP (200 microL of a 1 microm PACAP solution in each nasal cavity), with and without the addition of histamine. Cells, albumin and IL-1-related mediators were analysed in nasal lavage. In addition, the effects on pulse, blood pressure, ECG and pulmonary function were evaluated.

RESULTS

In the nasal mucosa, PACAP-like immunoreactive nerve fibres were seen close to blood vessels and seromucous glands. Application of PACAP in the nasal cavity increased NAR and augmented the increase in NAR induced by histamine. In addition, PACAP inhibited histamine-induced recruitment of neutrophils, increased plasma leakage and reduced the level of IL-1RA (an endogenously produced IL-1 receptor antagonist) in nasal lavage. Cardiovascular and pulmonary parameters were not affected.

CONCLUSION

These results imply that PACAP is an important endogenous mediator in human upper airways, with a potential role as a regulator of vascular smooth muscle, secretion, plasma extravasation, neutrophil recruitment and cytokine activity.

Impression cytology study of conjunctival epithelial phenotypes on the healing ocular surface after pterygium excision

PURPOSE

To compare the process of conjunctival epithelial regeneration after three types of pterygium excision procedures.

METHODS

Thirty-eight patients (45 eyes) with primary pterygium were randomly assigned to a bare-sclera procedure (group 1, 15 eyes of 12 patients), bare-sclera with intraoperative mitomycin C (MMC 0.02% for 30 seconds; group 2, 15 eyes of 14 patients), or pterygium excision with conjunctival autografting (group 3, 15 eyes of 12 patients). Controls were healthy fellow eyes and seven eyes of age- and sex-matched subjects. Impression cytology was performed preoperatively, at 1 and 2 weeks, and at 1, 3, 6, and 12 months after surgery. The nucleus-to-cytoplasm (N/C) ratio of nongoblet epithelial cells and goblet cell density (GCD) in the pterygial area were calculated and compared over time across treatment groups.

RESULTS

Pterygium excision wounds healed in a similar four-stage process in all groups, but at different rates and with different final results. The N/C ratio was highest at about 1 month postoperatively in groups 1 and 2 and at 2 weeks in group 3, before gradually returning to control levels. Preoperatively, the GCD in treated eyes was almost twice that in control eyes (p = 0.001) but fell to zero immediately postoperatively. Goblet cells first appeared (with the most rapidly increased density) in group 3, followed by group 1. At 12 months, the mean GCD in groups 1 and 3 were not significantly different from those in controls, whereas the mean GCD in group 2 was still less than that of control (p = 0.02).

CONCLUSIONS

Healing of conjunctiva is delayed by MMC and is promoted by autografting. Even 1 year after surgery, the ocular surface remains abnormal with respect to epithelial phenotypes in eyes treated by any of the three techniques.

Transformation of mucosal secretory elements in chronic maxillary sinusitis after endoscopic sinus surgery

To evaluate the secretory element transformation of maxillary sinus mucosa after endoscopic sinus surgery (ESS), I enrolled 20 patients. Five normal antral mucosae were used as controls, and 15 antral mucosae were investigated according to pathologic and secretory patterns. The post-ESS mucosa was evaluated at the 16th week, when gross recovery appeared. Specimens from the rear wall of the antrum were observed under a scanning electron microscope (x2,000). A significant decrease of goblet cells and increase of glands was illustrated in the sinusitis cases, especially the polypoid and purulent groups. In post-ESS cases, the number of goblet cells is about the same as in controls, but the number of gland openings is higher. My conclusions were that 1) the repair of the antral mucosa requires more time than gross recovery and 2) post-ESS follow-up should be longer than 16 weeks to prevent recurrence.

Conjunctival epithelial cell hypermitosis and goblet cell hyperplasia in atopic keratoconjunctivitis

Atopic diseases that include eczema (atopic dermatitis), asthma, and seasonal and perennial rhinoconjunctivitis are common manifestations of abnormal immediate hypersensitivity. Ocular involvement, such as atopic keratoconjunctivitis, characteristically includes conjunctival and corneal inflammation, and in a severe form, conjunctival scarring, symblepharon, corneal epitheliopathy, and visual loss. To examine the conjunctival cellular abnormalities in atopic keratoconjunctivitis, we studied the in vivo differentiation and tissue-culture growth characteristics of conjunctiva from normal subjects and patients with severe atopic keratoconjunctivitis. We examined conjunctival biopsy specimens to determine epithelial mitotic rate and goblet cell frequency, and we studied conjunctival explants to determine the latent period for fibroblast outgrowth and fibroblast doubling time. The mitotic rate for atopic keratoconjunctivitis, 6.7% +/- 2.1% (11 patients), was statistically significantly greater than for normal subjects, 2.0% +/- 0.63% (seven subjects) (P = .05). Also the goblet cell frequency for atopic keratoconjunctivitis, 14.6% +/- 3.4% (11 patients), was statistically significantly greater than for normal subjects, 4.8% +/- 0.92% (seven subjects) (P = .02). The latent period for fibroblast outgrowth and the fibroblast doubling time for atopic keratoconjunctivitis were not statistically significantly different from normal control subjects. Therefore, atopic keratoconjunctivitis was associated with conjunctival epithelial hypermitosis, goblet cell hyperplasia, and normal fibroblast tissue-culture growth. These characteristics may be useful in the diagnosis of atopic keratoconjunctivitis. We previously studied another disease characterized by chronic conjunctival inflammation and scarring, cicatricial pemphigoid, which also demonstrated conjunctival epithelial hypermitosis, but in contrast there was near absence of goblet cells, and the fibroblasts were hyperproliferative. These differences may be used to distinguish atopic keratoconjunctivitis from cicatricial pemphigoid.

Nasal glands and goblet cells in chronic hypertrophic rhinitis

Partial turbinectomies were done in 13 patients suffering from chronic hypertrophic rhinitis. The mucous membranes were fine-dissected, and mucous elements were stained and counted using the PAS-alcian blue whole-mount method. Cross-sections were made from the whole-mount specimens. There was a great variety of epithelial types. Comparison of the density of mucous elements in normal patients and patients with chronic hypertrophic rhinitis revealed no statistically significant differences.

A study of experimental sinusitis in rabbits

Sinusitis was experimentally induced in rabbits by injecting one ml of casitone semi-liquid agar containing Staphylococcus aureus 209P in the order of 10(7) per ml into rabbit's bilateral paranasal sinuses (which had been sensitized with a 2.5% concentration of a purified egg white albumin solution) through a percutaneous route with a sterilized syringe. Two weeks after the last injection the rabbits were sacrificed and dissected. Light microscopic (LM) and scanning electron microscopic (SEM) examination of pathomorphological changes in this experimental model revealed that chronic inflammation developed in the mucous membranes of the paranasal sinuses at a high incidence.

Histopathological Examinations of nasal polyps of different etiology

A safe differentiation between allergic and non-allergic polyps appears impossible by means of light or electron microscopical examination of polyp tissue. There are some indications, however, which point to the allergic or non-allergic origin and it seems that the relationship between eosinophils and plasma cells with a low index is characteristic for polyps of allergic origin. Eosinophils and round-cell infiltrations are present in all types of polyps. An index of eosinophils to plasma cells below 5 is indicative for allergy and should induce the pathologist to give a hint to the clinican for allergological work-up. An index above 5 is more corresponding with infective etiology. Any changes of the basement membrane, i.e., smaller or larger gaps or even absence, are found only very irregularly and are not typical findings in either way. An increased number of glands and collagenic fibres, especially under the epithelium, are more an expression of the age of the polyp. Since the conservative therapy as mentioned above leads to good therapeutical results, it is desirable that an allergological work-up should be done in any case which shows the histological findings indicative for allergic etiology. Thus, repeated operations with all the risks and uncertain therapeutical benefit can be avoided.

Abnormal "hair-like" filaments in chronic maxillary sinusitis . A scanning electron microscopic investigation

Scanning electron microscopic investigations were performed on the maxillary sinus mucosa of five healthy persons and seven patients with chronic maxillary sinusitis. The occurrence of previously undescribed hair-like filaments in one case of chronic maxillary sinusitis is presented. These abnormal filaments are much longer (about 50--60 micron) and thinner (about 0.08 micron) than normal kinocilia (about 0.2 micron thick and 5--7 micron long), thus exhibiting a hair-like appearance. As the microvilli (cytofila) in maxillary sinus mucosa have the same thickness (about 0.08 micron), these hair-like filaments could be regarded as abnormally long microvilli. The possible significance of these abnormal filaments is discussed.

Nasal glands in nasal allergy

The entire nasal mucosa from a patient with nasal allergy and hay fever was studied by the whole mount method, and the density of submucous glands was determined. Their density was essentially greater than in normal noses in all parts of the nose, especially on the conchae. This finding indicates that new-abnormal-glands form in the course of the disease, glands which also differ morphologically from the normally occurring glands. As this greatly increases the secretory capacity of the mucous membrane, there is a patho-anatomical basis for assuming that the nasal secretion in allergy is formed exclusively by the existing glands. Other sources of nasal secretion, such as exudation and transudation under normal conditions and in allergy, as well as the mode and causes of gland formation, are discussed.

Density of mucous glands in the normal adult nasal turbinates

On 13 normal inferior and middle turbinates the mucous membrane was freed, stained by the PAS-alcian blue whole-mount method, and the mean density of glandular orifices was determined by counting in 4 mm2 fields. The median density fell in both turbinates in the anteroposterior direction, being in the inferior turbinate 8.2 glands/mm2 anteriorly, 7.9 in the middle, and 7.1 glands/mm2 posteriorly. In the middle turbinate it was 8.4 glands/mm2 anteriorly, 8.1 in the middle, and 7.3 glands/mm2 posteriorly. There were no significant differences in median density between the medial and lateral wall or between the superior and inferior half of the inferior or middle turbinate as a whole. The median total number of glands in the inferior turbinate was 9,200 with a very wide interindividual range of 6,100-12,700. In the middle turbinate the median count was 6,700 glands and the range 4,400-11,500. The pathology of the mucous glands of the nose is discussed.