Search

The characteristics of the human olfactory mucosa were studied immunohistologically. Regular, zonal distribution of the supporting cells, multilayered olfactory receptor cells and basal cells was commonly found in the olfactory mucosa of the human fetus. In contrast, most of the olfactory mucosa in the adult varied to some extent. In the relatively thick, slightly degenerated olfactory mucosa, olfactory marker protein positive receptor cells were arranged irregularly. The most common evidence for variation was the decrease or disappearance of the olfactory receptor cells. Serous-type lactorferrin-containing glandular acini were characteristically found beneath degenerated epithelium. Islands of respiratory epithelium were also seen. The ductules of the Bowman's glands were distended and the openings of these ductules were wide. There was invagination or epithelial cell processes into the glandular lumina. These findings suggest that the epithelial cells of Bowman's glands play an important role in the regeneration of the human olfactory mucosa.

Patients with allergic and non-allergic nasal disorders may complain of symptoms of itching, discharge, congestion or fullness, and obstruction of airflow. The actions of sensory nerves and parasympathetic reflexes are central to the development of these symptoms, and likely play crucial roles in allergic and non-allergic nasal pathology. Nasal provocation studies have provided much information about the nature of the processes which contribute to the production of nasal secretions and the development of obstruction to nasal air flow. The results of human nasal provocation studies will be discussed after a review of the special anatomy of the human nasal mucosa, its vasculature, and its innervation.

Monoclonal antibodies (mAbs) were generated that react with the major cell types in the olfactory neuroepithelium of the frog, Rana catesbeiana. This pseudostratified epithelium consists of apical supporting cells, a middle layer of olfactory receptor neurons and a heterogeneous population of basal cells consisting of basal cells proper and globose basal cells. Both olfactory receptor neurons and globose basal cells were labelled by mAb 13-OE, which recognized the neural cell adhesion molecule NCAM. The identity of these NCAM positive cells was established by analysing regenerating olfactory epithelium and by a double-antibody labelling immunofluorescence technique. The olfactory nerve was lesioned, which induced the death of olfactory receptor neurons and the subsequent proliferation of basal cells. When the regenerating olfactory epithelium was analysed prior to the reconstitution of mature olfactory neurons, mAb 13-OE reacted specifically with globose basal cells and not the basal cells proper. Simultaneous labelling of normal olfactory epithelium with mAb 13-OE and polyclonal anti-keratin antibodies, the latter of which labels supporting cells and basal cells proper, revealed no double-labelled cells. These results further confirmed that NCAM was expressed by both globose basal cells and receptor neurons but not by other cell types within the epithelium. Additional cell types in the olfactory epithelium reacted with other new mAbs: 4-OE, 5-OE, 7-OE and 9-OE. Supporting cells were stained by mAb 4-OE. Olfactory receptor neurons and the entire population of basal cells were immunoreactive with mAb 7-OE. The cilia and knobs of receptor neurons were strongly immunoreactive with mAb 5-OE whereas mAb 9-OE selectively stained olfactory knobs and not the cilia on these chemosensory cells. These studies are a first step towards experimental approaches designed to elucidate the mechanisms underlying the unique proliferative properties of the olfactory neuroepithelium in frog.

The specific binding of 125I-(-)-cyanopindolol (125I-(-)-CYP) to homogenates and cryostat sections of rat nasal mucosa was saturable, stereoselective and of high affinity (Kd = 5.0 +/- 0.4 pM. Bmax = 204 +/- 12 fmol/mg protein and Kd = 7.2 +/- 0.7 pM; Bmax = 15 +/- 1 fmol/mg protein respectively). The subtype-selective antagonists, LK203-030 and ICI118,551, inhibited specific 125I-(-)-CYP binding according to a two-binding site model, indicating the presence of 57 and 45% beta 1-adrenoceptors in homogenates and cryostat sections, respectively. Competition of isoprenaline for antagonist binding to homogenates demonstrated 30 +/- 3% high-affinity agonist binding sites. A steepening of the curve was observed in presence of guanine nucleotides. In vitro labelling of cryostat sections of rat nasal mucosa was combined with autoradiography. The autoradiographs generated after incubation with 20 pM 125I-(-)-CYP showed specific labelling of the epithelium and glandular excretory ducts. It appeared from autoradiographs generated with subtype-selective antagonists in addition to the radioligand that beta 1- and beta 2-adrenoceptors were present in both structures.

Epithelial tissues from the rostral half of the pig nasal cavity were prepared for light and electron microscopy. The predominant epithelial cell type at the luminal surface was cuboidal with surface microplicae or microvilli and a multilobate nucleus. Pinocytotic vesicles were a common feature of the adluminal cytoplasmic zone of these superficial cuboidal cells. Other cell types included basal cells, intermediate cells and, occasionally, goblet and ciliated cells. Basal cells contained vesicles located adjacent to the basal lamina. This transitional mucosa may be specialised for sampling substances from the luminal surface preliminary to releasing cytokines and, or, presenting immunogens to intraepithelial lymphocytes.

A rat model has been developed to compare relative morphological changes in the nasal mucosa after exposure to potential membrane permeation enhancers. Scanning electron microscopy was used to characterize gross structural and specific cellular changes following exposure. Micrographs of the rat nasal mucosa were scored in four categories: (1) mucosal surface integrity, (2) ciliary morphology, (3) mucus/extracellular debris, and (4) presence of red blood cells. The order of increasing morphological damage resulting from a 5-min exposure to each surfactant was 0.5% Solulan C-24 congruent to 0.5% Solulan C-24/0.5% sodium tauro-24,25-dihydrofusidate (STDHF) less than 0.5% STDHF less than 1.0% STDHF much less than 1.0% Laureth-9 less than 1.0% sodium taurodeoxycholate congruent to 1.0% sodium deoxycholate. The changes observed in the mucosal morphology after exposure to the various surfactants are in general agreement with data in the literature. This model is able to compare rapidly the relative morphological effects on the mucosal membrane of different nasal formulations.

The effectiveness of mixed micelles in promoting nasal absorption of peptides has been demonstrated in vivo by employing insulin as a model compound. Insulin in the absence of adjuvants was not absorbed following intranasal administration. The results confirmed previous findings by others that absorption of insulin via alternative routes required absorption enhancers. Mixed micelles between NaGC and linoleic acid were found to rapidly deliver insulin into systemic circulation, with a concomitant decrease in plasma glucose. The extent of the hypoglycemic response was significantly greater than that produced by NaGC alone (55 vs 47%, P less than 0.05). Emulsion of linoleic acid, on the other hand, did not produce any significant insulin absorption. The findings thus supported previous in situ data that mixed micelles were more effective than NaGC or linoleic acid in promoting nasal absorption of peptides. Histopathologic examination of the rat nasal mucosa revealed that the extent of morphological alterations caused by mixed micelles was of mild to moderate severity even after 5 hr of exposure. However, studies involving more frequent and prolonged exposures are necessary to assess the practicality of these adjuvants before any clinical application can be attempted.

An increasing number of chemicals have been identified as being toxic to the nasal mucosa of rats. While many chemicals exert their effects only after inhalation exposure, others are toxic following systemic administration, suggesting that factors other than direct deposition on the nasal mucosa may be important in mechanisms of nasal toxicity. The mucosal lining of the nasal cavity consists of a heterogeneous population of ciliated and nonciliated cells, secretory cells, sensory cells, and glandular and other cell types. For chemicals that are metabolized in the nasal mucosa, the balance between metabolic activation and detoxication within a cell type may be a key factor in determining whether that cell type will be a target for toxicity. Recent research in the area of xenobiotic metabolism in nasal mucosa has demonstrated the presence of many enzymes previously described in other tissues. In particular, carboxylesterase, aldehyde dehydrogenase, cytochromes P-450, epoxide hydrolase, and glutathione S-transferases have been localized by histochemical techniques. The distribution of these enzymes appears to be cell-type-specific and the presence of the enzyme may predispose particular cell types to enhanced susceptibility or resistance to chemical-induced injury. This paper reviews the distribution of these enzymes within the nasal mucosa in the context of their contribution to xenobiotic metabolism. The localization of the enzymes by histochemical techniques has provided important information on the potential mechanism of action of esters, aldehydes, and cytochrome P-450 substrates known to injure the nasal mucosa.

There are three major epithelial types in the nasal mucosa, in addition to numerous accessory structures, some of which are species specific. Without careful and consistent processing of the nose tissue, histopathologic assessment of lesions in the nasal cavity may be compromised. While formalin fixation may be used for routine review of the nasal cavity, Bouin's fixation provides better histologic detail and fewer artifacts. Decalcification is not recommended for nasal tissues to be examined by transmission electron microscopy because of the detrimental effect of decalcifying solutions on sensory cells. Three levels of the nasal cavity may be used for routine histologic review of the nasal cavity, but four or five levels may be more appropriate for certain studies.

The vomeronasal system (VNS) seems to be functional in some primates and involved in the detection of urinary signals. Anterograde tracing (WGA-HRP) and evoked metabolic activity (2-DG method) were used in order to clarify the conditions under which the VNS is activated in the prosimian mouse lemur. After WGA-HRP deposition at one of the oral entries of the nasopalatine duct, reaction product was observed within the accessory bulb (AOB). 2-DG experiments show that urine in the volatile phase stimulates the main but not the accessory bulb (AOB). Liquid urine produced bilateral or unilateral activation of AOB depending on whether the stimulation was exclusively unilateral or not; under the same conditions distilled water could not produce 2-DG labelling. It is concluded that VNS is activated by urine in the liquid but not the volatile phase. The biological implications of these results are discussed.

Implants were inserted in the upper jaw of three dogs in such a way that they penetrated the bone wall of the nasal cavity. The dogs were killed one year later, and the hard and soft tissues around the penetrating implants were analyzed. Radiographic and histologic examinations did not show any signs of adverse tissue reaction. The implants were all integrated in bone without fibrous tissue formation in the interface. A total of 139 implants, which pierced the bone of the sinus or nasal cavity, were inserted in the upper jaws of 101 patients. Forty-four sinus- and 47 nasal-penetrating implants were observed for five to ten years. The success rates were 70% and 72%, respectively. For 25 sinus- and 23 nasal-penetrating implants that were observed for two to five years, the success rates were 88% and 96%, respectively. The implant losses in nearly all clinical cases occurred during the first two years of function.

In 49 rabbits the mucoperichondrium of their nasal septa was strictly unilaterally separated according to the Cottle procedure. In addition, in some rabbits only the surface of the septal cartilage was incised and in others the cartilage was cut vertically or horizontally. Four months after the operation the following alterations of the septa were seen: The separation of the mucoperichondrium from the cartilage or superficial incision of the cartilage led to a deviation to the operated left side. If in addition parts of the cartilage septum were mobilized, thus swinging horizontally or vertically, a deviation to the other nonoperated side was seen. Similarly, if two parallel vertical stripes of cartilage were excised, the ends of the remaining cartilage plate bent and the cartilage plate itself deviated to the nonoperated side. The postoperative deviations are due to released unbalanced forces of the cartilage itself and to the disequilibrium of scar tension resulting from the unilateral separation of the mucoperichondrium. To avoid these postoperative deviations the bilateral tunneling of the mucoperichondrium is required.

The mucosa of the posterior part of the nasal septum is studied by in vivo observations in 40 seemingly healthy adults, vascular injection of two anatomical specimens rendered transparent, histological studies of serial sections of five anatomical specimens, and macroscopic and histological examination of specimens obtained from 20 cadavers. The presence of an "adenovascular" body was noted in the posterior part of the nasal septum; this body occupies about one fifth of the total area of this region. This study shows that this is a normal structure of the nose and suggests that its name be changed to adenovascular body of the posterior part of the nasal septum.

The histology of the human soft palate seen in four whole soft palates and four mucosal biopsies has been described, with an emphasis on the elastic fibres. Striking features were the presence of much fat, thick interglandular connective tissue septa, considerable elastic tissue, and a complete absence of taste buds.

This study was based on a method of microphotometrical measurement of the ciliary beat of cells from the human upper respiratory tract. The ciliated cells were acquired by the tissue cultivation of small pieces of nasal mucosa obtained during surgical interventions in the paranasal sinuses. The experiments were performed in a chamber where the cells were superfused by a tyrode solution. The ciliary beat was measured by a microscope photometer built into an inverted microscope. During the measurements the diaphragm aperture of the photometer was positioned over the cilia in such a manner that the changes of light intensity resulting from the movement of the cilia could be registered. The frequency of the ciliary beat was estimated by counting the individual beats. The ciliary beat during control conditions was studied as well as the influence of temperature. Cooling of the experimental chamber resulted in a significant reduction of the frequency of the ciliary beat. The advantages of this single cell preparation of ciliated epithelia for pharmacological investigations are discussed.

In various respiratory areas of the mucosa of the nasal conchae of the zebu (Bos indicus) there is a quantitative variation of goblet cells. The glands are tubular or tubulo-alveolar, having morphologically serous and mucous cells. The excretory ducts are formed by non-secreting cells. The goblet cells and glands elaborate a glycoprotein. The carbohydrate portion is probably an association of neutral mucopolysaccharides, sulphated acid mucopolysacchardies and sialic acid and its proteic portion contains alpha-amino radicals. Tryptophan- and tyrosine-rich proteins are demonstrated only in the glandular secretion.

Secretory components of the salamander olfactory mucosa, sustentacular cells (SC), and Bowman's glands (BG), were examined histologically and histochemically. In the aquatic larval salamander, SC in sensory grooves contained secretory granules; the submucosa contained a single layer of homogeneous, ductless glands. In the land-dwelling adult salamander, SC spanning a flat epithelial sheet contained vesicles. Subjacent to the epithelium in both dorsal and ventral mucosae lay BG whose ducts opened at the surface of the epithelium. In the ventral mucosa, two additional layers of olfactory glands (OG) lying below the BG were identified; ducts were not observed in association with the OG. The beta-adrenergic agonist isoproterenol caused depletion of secretory granules from BG and OG of larval, young, and adult salamanders but had no discernible effect on SC. Histochemical techniques (Alcian blue at pH 2.5 and pH 1.0, high-iron diamine, and the periodic acid-Schiff reaction) demonstrated that SC contained neutral, acidic, and small amounts of sulfated mucopolysaccharides (MPS), BG and OG contained only neutral MPS. In contrast, glands under adjacent respiratory epithelium contained both acidic and sulfated MPS. Unilateral olfactory nerve section ( ONX ) caused changes in the histochemical reactivity of acidic and sulfated MPS in SC on the ipsilateral and later on the contralateral side. Neutral MPS staining became enhanced first in the OG that lay under the BG, then in BG cells, and later in the deepest OG layer. Ipsilateral changes preceded contralateral ones. At 24 days post- ONX , some acinar cells in the deep OG contained acidic but not sulfated MPS.

Correction of the saddle nasal deformity requires generous elevation and mobilization of the overlying soft tissue, the restoration of skeletal support, and the provision of nasal mucosa lining ("the forgotten link"). For moderate to severe saddle deformities, calvarial bone grafts serve well to reconstruct the disrupted skeletal framework.

We studied the histopathological effects of CO2 laser use on the nasal septum of nine rabbits. In the rabbits irradiated with no more than three bursts at four watts, healing was prompt and complete; more than three bursts caused cartilage necrosis. The CO2 laser, using appropriate settings, is safe and effective in treating anterior septal lesions. These settings can be established only after histological examination of the lesions.

The serum levels of two enkephalins after various routes of administration were compared in rats. The results indicated that serum levels of metkephamid after nasal administration were not significantly different than levels after intravenous injection. The oral administration of metkephamid resulted in undetectable serum levels. The effects of a promoter and variations in the peptide dose on nasal absorption were studied. Depending on the stability of the polypeptide and its susceptibility to enzymatic degradation, nasal absorption of peptides can be influenced by the presence of a promoting agent in the formulation. A linear relationship between the dose and the AUC was observed in the range of concentrations studied. The absorption mechanism appears to be passive diffusion. Microscopic examinations of nasal mucosa in rats revealed degrees of irritation which, considering the experimental exposure, were slight and probably repairable. The data indicate that enkephalins can be absorbed through the nasal mucosa into the systemic circulation, and the onset of absorption was rapid. Nasal administration may offer an attractive alternative for the delivery of proteins and/or polypeptides which are, in general, absorbed poorly when given orally.

The entire mucosa from 10 normal maxillary sinuses was removed post-mortem and stained by the PAS-alcian blue whole-mount method. The density of goblet cells and of mucous glands was investigated. The median density of goblet cells was 170 cells/field, corresponding to 9,600 cells per mm2, with wide individual variations, but there were no significant differences in density between the various walls. The density of goblet cells was somewhat higher than in the nose. Glands were very scarce and small in the maxillary sinus. Their median density in most walls was 0.15-0.20 gland/mm2, but in the medial wall significantly higher, 0.5 gland/mm2. The lower density of glands in the maxilly sinus than in the nose, where it is 8-9 glands/mm2, is in complete agreement with lesser requirement of the antral mucosa for moistening, cleaning, and warming of the air. Quantitative histological studies of normal mucosa will form the basis for studies of abnormal mucosa.

A single dose of 8-16 mg of carbon C11/1431a was injected intravenously into rats, guinea-pigs, mice, goats and two pigs. Examination with the naked eye, dissecting microscope, light microscope and electron microscope of tissues from these animals sacrificed minutes, hours, weeks and up to 23 months after the injection revealed phogocytosis of most of the infected carbon by the professional phagocytes of the reticuloendothelial system (RES). However, in the non-RES sites carbon was trapped in significant amounts in the endothelial cells, the interendothelial spaces, pericytes and perivascular macrophages of the subepithelial capillaries and venules in the anterior nasal mucosa. The catchment area often showed partially fenestrated capillaries and redundant porous basement membrane around the venules. The leakage of carbon through these vessels was through these vessels was thought to be caused partly by the unusual porosity of the vascular walls and partly due to vascular stasis induced by constant loss of heat to the inspired air stream in post-natal life. The importance of these findings in the predilective localization of several granulomatous diseases and various forms of vasculitis in the nasal mucosa id discussed.

In 50 fetuses and premature infants between the ages of 11 and 23 weeks the entire nasal mucosa was dissected free and stained by the Osmium, the PAS or the PAS-alcian blue whole-mount method after which the nasal mucous glands were studied with special reference to density. In front on the septum and in the lateral wall density increases evenly and is by the 23rd week 28 glands per square mm. In the middle and at the back of the septum, where the glands develope later, the density is somewhat smaller by the 23rd week. Through the entire period, and also after the 23rd week, new glands continue to develop a fact which is of importance for the understanding of the distribution of the glands since the first glands to develop form a glandular layer deep in the lamina propria and the last glands to develop a superficial layer.

The possible role of flehmen behavior in facilitating the passage of non-volatile materials from the oral cavity to the vomeronasal organ (VNO) was studied by the use of a tracer dye, sodium fluorescein. The dye was applied to the oral cavity of six male goats in which flehmen was elicited by the presentation of female urine. Immediately afterwards a lethal dosage of anesthetic was given and the maxilla, including the VNO, was removed, frozen, and cut into transverse sections. Seven control subjects were treated similarly but were not stimulated to display flehmen. Examination of transverse sections under ultraviolet illumination revealed dye in the posterior part of the VNO in most subjects that performed flehmen but only in the anterior part of the VNO of subjects that did not perform flehmen. Inasmuch as only the middle and posterior parts of the VNO contain sensory epithelium, it was concluded that, if the dye represented a behaviorally significant non-volatile material (sex attractant), only the goats that showed flehmen would have detected the material from VNO chemoreception.

As a result of histological investigation performed in nasal cavities of 28 persons died at the age of 17-82 years of age and in two human fetuses at the age of 30 and 40 weeks, it has been established that in the mucosal tunic of the concha nasalis besides nutritive arteries of a common structure, shunt arteries, having a complete analogy with the cochlear arteries of the cavernous bodies of the genital organs, are common findings. They have a narrow lumen, thick middle tunic consisting of epithelioid cells, no elastic membrane and are opened according to the glomal anastomosis type or the cochlear labyrinth type into the lacunae of the cavernous bodies. Therefore, the nasal cavernous bodies should be regarded as true ones. They occur constantly but alternate with venous plexuses, since they are situated together with the latter in the fibrous stroma of the tunica mucosa. They are hermetizing venous structures.

Morphologic and immunologic study were performed on the mucosa associated lymphoid tissue (MALT) of patients with allergic rhinitis. Scraping from 14 healthy subjects and 36 allergic ones were used. Besides ordinary hystological methods immunohistochemical ones wilk polyclonal antibodies were employed to study IgG, IgA, IgM, IgE and monoclonal antibodies used for B and T lymphocyte and subset T-suppressor cell identification. In a comparison between normal and allergic mucosa, the morphopathology show an accentuated edema and a slight fibrosis. Among the IgG, IgA and IgM do not show any substantial differences in the samples in normal or in allergic subjects; white traces of IgE are found in allergic patients, but are totally absent in normal ones. In the lymphocyte populations does not show any substantial changes between the two groups. Was also analyzed the mechanism and the majority of the factors by which were obtained the results.

A review of studies of the nasal mucous elements by whole-mount methods. Goblet cell development is described till the 30th week of gestation, by which density is still very small. Density must increase towards and after birth. Some problems concerning intraepithelial, anterior nasal as well as Bowman's glands are discussed. The development of the small sero-mucous glands is described and their distribution and density discussed.

The secretory characteristics of the glands in both the lateral nasal wall and the nasal septum of the rat have been studied with a variety of morphological and histochemical techniques. The main part of the glandular tissue in the lateral nasal wall is situated around the ostium of the maxillary sinus and can be divided in a dorsal, simple branched acinous glandular part and in a ventral, very branched tubulo-acinous glandular part.. No further morphological differences can be observed with light microscopical techniques. The glandular tissue on the nasal septum consists of a large, branched tubulo-acinous gland, occupying an extensive portion of the septum. By using various histochemical staining techniques for glycoproteins, 3 different areas can be distinguished, suggesting that the nasal glands produce different types of secretory products.

A histotopographic study of the nasal septum mucosa in rats was made using semi-serial sections stained with PAS-hematoxylin, reconstructed in form of maps representing the structure in a sagittal plane. The stratified squamous, respiratory and olfactory epithelia and Masera's organ cover 14.8, 43.6, 41.6 and 1.8%, respectively, of the septal surface (117.1 mm2). In the vestibular region, only ducts of PAS-negative glands of the respiratory region are found, and below the septum there is the infraseptal gland with PAS-negative acini. In the respiratory region, PAS-negative acinous glands form two groups: the superior and the inferior one occupying 10.5 and 1.5%, respectively, of the septal area. PAS-positive acinous glands are in the inferior half of the respiratory region and in a small anteroinferior portion of the olfactory region. Besides goblet cells broadly distributed, the respiratory epithelium presents scattered intraepithelial PAS-positive glands which are concentrated in the anterior portion and close to the nasopharyngeal duct. In the olfactory region prevail Bowman's PAS-positive glands which are also present in the mucosa of Masera's organ, but are not seen in the olfactory mucosa of Jacobson's organ. In the latter, PAS-positive glands are found in the respiratory mucosa. Globular leukocytes, cells of connective tissue origin, are constantly infiltrating the superior regions of the respiratory and olfactory epithelia, being more numerous in female rats.

The olfactory epithelium, but not the nasal respiratory epithelium, of the four pocket mice (Perognathus longimembris) that survived their flight on Apollo XVII showed both diffuse alterations and numerous disseminated focal lesions. The olfactory mucosa of the mouse that died during flight was also affected, but to a minor degree insofar as could be determined. All this was in contrast to the normal appearance of the olfactory mucosa of the numerous control animals. A number of possible causes were considered: systemic or regional infection; inhaled particulate material (seed dust); by-products from the KO2 bed in aerosol or particulate form; gas contaminants originating in the flight package; volatile substances from the dead mouse; weightlessness; and cosmic ray particle radiation. Where feasible, studies were conducted in an effort to rule in or rule out some of these potentially causative factors. No definitive conclusions were reached as to the cause of the lesions in the flight mice.

Lateral nasal glands of 12-15 weeks old pups are immature. Gland acini of pups and mature dogs contain numerous electron-lucent vacuoles with basophilic, electron-dense cores. The vacuoles contain both acid and neutral glycoproteins, sialated glycoproteins being the dominant acidic moiety. Lateral and basal cytoplasmic extensions of the acinar cytoplasm greatly increase the cell surface are. Electron-dense granules, smaller and less numerous than the lucent vacuoles of acini, occur in intercalated duct cells. Secretions collected form the excretory duct of the lateral nasal gland from conscious dogs contain 235 mg protein/100 ml secretory fluid. Immunoglobulin A accounts for 14% of the secretory protein. Total sialic acid content is 0.024% of the secretion by weight.

The olfactory bulbs were removed surgically from Large White male and female pigs, 10--12 weeks of age. At intervals of 3, 7, 14, 42 and 84 d after bulbectomy, the pigs were sacrificed and portions of olfactory mucosa were removed from the ethmoturbinate and septum regions of the nasal cavity; olfactory mucosa was also removed from unoperated pigs. A piece of each tissue sample was processed for light microscopy. The remaining tissue was placed in Ringer-Locke solution, saturated with O2/CO2 at room temperature, and the electrical activity of the olfactory epithelium was investigated in vitro by passing a stimulus of butyl acetate vapour over the epithelium. Slow negative potential changes (electro-olfactogram, e.o.g.) induced by butyl acetate were recorded. During the first two weeks after bulbectomy there was a rapid decrease in the height of the olfactory epithelium associated with the disappearance of the e.o.g. response. However by 42 and 84 d after bulbectomy, partial recovery of the height and some electrical activity of the olfactory mucosa had occurred. In some pigs, the insertion of a stainless steel lining over the cribriform plate to prevent any association of regenerating axons with forebrain tissue had no effect on the regenerative characteristics studied.

The entire mucosa of the nasal septum from four newborn infants was removed, stained by the PAS-alcian blue whole-mount method, and the density of mucous glands was determined in 12 different localities. The interindividual median density was 30.7 glands/mm2 and the median count 13,500 glands. The glands were regularly distributed over the entire respiratory region, but with a significant decrease in density in the posterior half. It has been demonstrated that all glands are laid down before birth, that their density decreases with increasing age until it reaches 8.4 glandss/mm2 at an adult age, and that acute or recurrent acute catarrhal or inflammatory changes of the nose do not lead to the newformation of glands.

The possible mode of action of the recently demonstrated steroid effect on the immediate type allergic reaction has been studied. The influence of a topical steroid, budesonide, on the nasal mucosal histamine content and anti-IgE induced histamine release was studied in an open study. A 1-week treatment with budesonide, used locally in the nose, was administered to 22 hay fever patients who were studied out of the pollen season. There was a decrease of histamine content after steroid treatment and also a blockade of the anti-IgE mediated histamine release, as shown in an in vitro release procedure. This steroid effect may partly explain the effect of steroids on the immediate reaction, as it has been demonstrated in allergen challenge studies.

The histology and carbohydrate histochemistry of the nasal mucosa with attention to glandular tissue had been studied in 7 heads of sheep. Tissues were taken from vestibular region, septum at level of the alar fold, rostral portion of nasal conchae, caudal portion of nasal conchae, middle portion of septum and ethmoidal conchae region. Stratified squamous nonkeratinized epithelium was observed covering the vestibular region. The propria-submucosa of the nasal vestibule was richly permeated with glands having affinity for PAS and non-alcianophilic. The post-vestibular portion of the nasal cavity was lined by transitional epithelium and caudal to it, stratified columnar nonciliated epithelium was noticed. The respiratory epithelium covered the caudal half of the nasal conchae and the major portion of the septum as well as the recesses of the ethmoidal conchae. The glands associated with the respiratory mucosa were thick, coiled and tubular, containing both nonalcianophilic PAS positive and alcianophilic PAS positive cells. The olfactory mucosa covered the ethmoidal conchae and showed predominant serous glands. The results were discussed with that given for other mammals and in regard to the respiratory functions of the nasal mucosa.

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.

Magnetic resonance studies frequently demonstrate increased T2-weighted signal in the nasal area. To further evaluate this phenomenon, several MRI examinations of the nasal cavity were performed within an 8- to 12-hour period. The study demonstrated that changes alternated from side to side and were interrupted by the administration of topical vasoconstriction, confirming imaging of the normal nasal cycle. Changes were also observed within the ethmoid sinuses. Signal intensity on T2-weighted images during the congested phase was similar to inflammatory mucosa. Occasionally, these changes make interpretation of the extent of pathology difficult in patients with sinus disease, and raise the possibility of inflammatory pathology in asymptomatic patients. Awareness of MRI imaging of nasal cycle should reduce the likelihood of diagnostic errors and provides another method for study of this physiologic phenomenon.