Search PubMed⌕ Search

Biomedical subjects

P Stierna

Publications and source records attributed to P Stierna.

At least 19 recordsLinked to original sources

Changes in immune regulation in response to examination stress in atopic and healthy individuals.

BACKGROUND: Stress can aggravate the allergic inflammation, but determinants of disturbed immune regulation are largely unknown. OBJECTIVE: To determine systemic immunological, local inflammatory and functional airway responses to stress in healthy and atopic individuals. METHODS: Forty-one undergraduate students, 22 with allergy of whom 16 had asthma, and 19 healthy controls, were studied in a low-stress period and in association with a large exam. Subjects completed questionnaires on stress and health behaviours, underwent lung function tests, bronchial methacholine challenge, measurements of exhaled nitric oxide and urine cortisol. Blood cells were phenotyped, and cytokines from mononuclear blood cells were analysed. RESULTS: Perceived stress and anxiety increased in both groups during the exam period while cortisol increased only in the atopy group. Cytokine production decreased broadly in response to stress in both groups, which was paralleled by an increase in the proportion of regulatory T cells (CD4(+)CD45RO(+)CD25(bright)). Interestingly, atopic individuals, but not controls, reacted with a decreased T-helper type 1/T-helper type 2 (Th1/Th2) ratio and a decrease in natural killer (NK) cell numbers in response to stress. In control subjects only, exhaled nitric oxide decreased and forced expiratory volume in one second increased during stress. CONCLUSION: Atopic and non-atopic subjects shared some immune changes in response to stress, such as a dramatic decline in cytokines and an increase in the number of regulatory T cells in peripheral blood. However, other stress-induced immune changes were unique to atopic individuals, such as a skewed Th1/Th2 ratio and reduced NK cell numbers, indicating that some pathogenic mechanisms in atopics may be more strongly affected by stress than others.

Adult↗

Development and characterization of an animal model of dental sinusitis.

CONCLUSION: The results of this study confirm that the present rabbit model of dental maxillary sinusitis (dMxS) is reproducible and simulates human dental sinusitis with respect to initiation, progression and inflammation. It is applicable to further studies of sinusitis of odontogenic origin. OBJECTIVES: To induce acute dMxS in rabbits by using their own oral microflora to create a periapical infection and to follow morphological, radiographic, bacteriological and histological changes to the sinus mucosa. MATERIAL AND METHODS: The experimental animals comprised 26 New Zealand White rabbits. Maxillary premolar root canals were identified bilaterally and the continuously growing germs of the roots were severed by diathermy. The animals were randomized into 2 groups: in Group 1 (n=20) the teeth were left open for the entire study period; in Group 2 (n=6) the root canals were sealed 1 week after the initial intervention. The animals in Group 1 were sacrificed at intervals ranging from 2 h to 9 months after intervention. All animals in Group 2 were sacrificed 6 months after intervention. After macroscopic and radiographic examination, post-mortem inspection of the paranasal sinus cavity and maxillary complex and microbiological sampling, the entire nasal sinus complex with the hard palate in situ was resected and processed for serial coronal sectioning. RESULTS: In Group 1, after 3 months, the radiographic changes ranged from widening of the periodontal space to bone reaction. At sacrifice, changes in the sinus mucosa ranged from signs of mucosal inflammation to purulent dMxS. Microbial growth, predominantly Gram-negative aerobes, increased over time. In Group 2, the findings were generally more pronounced. Anaerobic microorganisms were predominant. In both groups the findings were consistent with dMxS.

Animals↗

Central and peripheral glucocorticoid receptor function in abdominal obesity.

Abdominal obesity seems to be associated with a moderately deranged feedback regulation of the hypothalamic-pituitary-adrenal (HPA) axis where central glucocorticoid receptors (GR) are involved. Therefore, functions of central and peripheral GR were compared in this study. Furthermore, since trinucleotide repeats in early exons of steroid hormone receptor genes influence transcription, and therefore may influence receptor density, this was also studied. Ten middle-aged men, 5 with abdominal obesity and 5 controls, were studied. The suppression of dexamethasone (dex) on serum cortisol was used in dose-response tests to assess the function of central GR. Abdominal adipose tissue biopsies were incubated and exposed to cortisol in different concentrations, and the function of the peripheral GR assayed as induction of lipoprotein lipase (LPL) activity. Aberrant expansion of exonic trinucleotide repeats in the first coding exon of the GR gene was studied by sequencing of genomic DNA. Results showed that men with abdominal obesity showed less inhibition of serum cortisol by dex, particularly at lower concentrations, while in the controls cortisol secretion was inhibited in an apparent dose-response manner. LPL activity in adipose tissue was lower in abdominal obese men than in controls. However, the sensitivity to cortisol was not different between the groups. There was no evidence for expansion of trinucleotide repeats. These results suggest that the central GR and the peripheral GR in adipose tissue exhibit functional differences in abdominal obesity.

Abdomen↗

Estrogen receptors alpha and beta in the inner ear of the 'Turner mouse' and an estrogen receptor beta knockout mouse.

Estrogen receptors have earlier been shown in the normal mouse, rat and human inner ear. If estrogens are important in normal hearing and development of presbyacusis in the normal population is not known. However it is known that patients with Turner syndrome, where a lack of estrogens is one of the main characteristics, commonly develop an early presbyacusis. A 'Turner mouse' has been developed, as a model for the ear problems in Turner syndrome, and it shows otitis media and a premature aging of the hearing. Estrogen receptors exist in an alpha and a beta form. In this study inner ear tissue, from the Turner mouse and an estrogen receptor beta knockout mouse (betaERKO), was investigated regarding estrogen receptor alpha and beta using immunohistochemistry. Results show that the Turner mouse has the same pattern of inner ear labeling, both concerning the estrogen receptor alpha and beta, as that of a normal CBA/Ca mouse, with positive staining in the organ of Corti and spiral ganglion. The betaERKO mice show close to normal inner ear morphology and positive estrogen receptor alpha immunostaining at the same locations as the CBA/Ca mouse.

Animals↗

Sensitivity of a new grading system for studying nasal polyps with the potential to detect early changes in polyp size after treatment with a topical corticosteroid (budesonide).

We have previously compared different scoring systems for endoscopic staging of nasal polyps. Of the five methods evaluated, we found that two were better than the others with regard to reproducibility and agreement between physicians. One method was lateral imaging, developed by the authors, and the other was a scoring system developed by Lildholdt et al. The main objective of the present study was to compare the sensitivity of these two methods. Another aim was to study the effect on nasal polyposis of topical nasal corticosteroids over a 2-week period. Patients with bilateral nasal polyposis (n = 100) were randomized to a 2-week treatment with a topical corticosteroid (budesonide aqueous nasal spray: 128 microg b.i.d.) or placebo in a double-blind manner. Nasal symptoms were scored before treatment and after 3, 7 and 14 days of treatment, and the patients underwent nasal endoscopy at clinical visits. Patients treated with active substance had an improvement in their symptoms, an effect already detectable after 3 days of treatment, compared with those who received placebo. In addition, a statistically significant decrease in polyp size could be registered after 14 days using lateral imaging but not with the other scoring system. In conclusion, lateral imaging was more sensitive and could detect effects earlier than the other scoring system and can be recommended for the endoscopic staging of nasal polyps in clinical studies.

Administration, Topical↗

Herpes simplex virus type 1 infection and glucocorticoid treatment regulate viral yield, glucocorticoid receptor and NF-kappaB levels.

The interplay between the endocrine and immune systems has come into focus in recent years with the insight that endocrine parameters may affect susceptibility to both auto-immune and infectious diseases. Our interest in immunoendocrine regulation led us to investigate the effects of glucocorticoids on Herpes simplex virus type 1 (HSV-1) infections. Glucocorticoids used to treat inflammatory conditions are not yet recommended for HSV-1 therapy, since they have been reported to prolong viral shedding both in vivo and in vitro. Here we report that glucocorticoids did not alter the viral yield in human gingival fibroblast (HGF) cell culture when glucocorticoid treatment and viral infection occured simultaneously, but the viral yield increased when cells were treated with the glucocorticoid dexamethasone (dex) prior to viral infection. We found that viral infection in our primary cell system increased NF-kappaB levels and DNA binding. In addition, the amount of glucocorticoid receptor (GR) increased following viral infection, and HSV-1 infection as such could induce glucocorticoid-driven transcription of a reporter gene in human embryo kidney (HEK) 293 cells stably transfected with GR. Dex treatment did not affect HSV-1-induced binding of p65 to an NF-kappaB element in an electrophoretic mobility shift assay, and acyclovir was still efficient as an anti-viral drug in the presence of dex. Further studies of the observed effects of HSV-1 infection and glucocorticoid treatment on GR and NF-kappaB regulation could give insights into the immunoendocrine mechanisms important for defence and therapy against viral infections.

Acyclovir↗

Current perspectives on the treatment of nasal polyposis: a Swedish opinion report.

This Swedish study group has examined the current knowledge of nasal polyposis with emphasis on different treatment modalities. Polyposis is a multifactorial disease that exists for decades in the majority of cases. Different types of treatment must be considered, focusing on the underlying disease. However, as we only know the specific origin of polyposis in a minority of cases, treatment is usually symptomatic. When making a thorough evaluation of different treatment strategies, it is obvious that there is a real need for more controlled treatment studies which would make the scientific ground more stable when it comes to suggesting medical, surgical or combined treatments.

Administration, Intranasal↗

Na,K-ATPase expression in the mouse cochlea is not dependent on the mineralocorticoid receptor.

This study was performed in order to test the hypothesis that the mineralocorticoid hormone stimulates the expression of Na,K-ATPase in the cochlea of the mouse. Immunohistochemistry was used to investigate the distribution of the mineralocorticoid receptor (MR) in the cochlea of the C57Bl/J6 mouse at different ages between gestational day 19 and postnatal day 30, and the occurrence and distribution of Na,K-ATPase in the inner ear of a mouse with a null mutation of the MR. Adult patterns of staining for MR were found as early as on gestational day 19 in the cochlea, with small changes thereafter. MR was detected in the same structures in the cochlea as Na,K-ATPase in earlier studies, where the amount of Na,K-ATPase increased after postnatal day 4. Thus there is latency between the increase of MR and the increase of Na,K-ATPase. In the cochlea of the MR deficient mouse, antibody labelling of Na,K-ATPase showed no significant difference as compared to the control wild type mouse. The hypothesis that mineralocorticoid hormone alone via MR stimulates the formation of Na,K-ATPase in the inner ear could not be confirmed by this study, and other regulating mechanisms must be considered.

Animals↗

Characterization of two novel mutations in the glucocorticoid receptor gene in patients with primary cortisol resistance.

OBJECTIVE: Primary glucocorticoid resistance is characterized by decreased sensitivity to cortisol signalling. We have performed genetic analysis of the glucocorticoid receptor (GR) gene in 12 unrelated patients with primary cortisol resistance as defined by a pathological dexamethasone suppression test. METHODS: Exon specific polymerase chain reaction amplification of the GR gene and sequencing of each exon was carried out. The two mutations were characterized in vitro in terms of glucocorticoid driven reporter gene activity in a transient transfection assay and in a ligand binding assay. Molecular modelling of the R477H mutant was performed based on the X-ray structure of the GR-DNA binding domain. RESULTS: Two novel mutations in the GR gene were found: R477H in the DNA-binding domain which is the first reported mutation in that region of the human GR gene and G679S in the ligand binding domain. The R477H mutation showed no transactivating capacity, whereas the G679S mutation had reduced transactivation capacity compared to the wild-type (wt) GR. When tested for ligand binding capacity, the G679S mutation had 50% binding affinity compared to the wt GR. The effect of the point mutation R477H was deduced by a comparison between the wt structure and the model of the mutant. The wt GR has direct and water mediated contact with the phosphate groups of the glucocorticoid responsive element (GRE) whereas, in the model, the mutation R477H has no contact with the GRE. The G679S mutation is located on the surface of the ligand binding domain, at a distance from the steroid-binding site. A previously reported polymorphism, AAT to AAC at amino acid position 766, was found in four of the patients. CONCLUSIONS: In two of 12 patients with clinical glucocorticoid resistance, mutant forms of GR could be found. The glucocorticoid resistance in vivo in these two patients corresponds to impaired function of the two mutated GR forms in two in vitro assays. The relevance of the conservative polymorphism for the glucocorticoid insensitivity noted in these patients remains to be clarified.

Adult↗

Glucocorticoid receptor mRNA in patients with ulcerative colitis: a study of responders and nonresponders to glucocorticosteroid therapy.

BACKGROUND AND AIMS: Up to 30% of patients with severe-to-moderate attacks of ulcerative colitis (UC) respond poorly to glucocorticosteroid (GCS) treatment. The reason for this unresponsiveness is unknown. AIM: Our aim was to evaluate possible differences in glucocorticoid receptor (GR) density in peripheral leukocytes and effects of low-dose GCS treatment on GR density and on the hypothalamic-pituitary-adrenal axis in UC patients who had received high-dose GCS treatment due to a moderate or severe attack. Eleven UC patients in remission who were responders (Rs) to previous GCS treatment were compared with 10 patients who failed GCS therapy and had a colectomy (nonresponders. NRs). Ten healthy individuals served as controls. METHODS: Quantitation of GR mRNA by a solution hybridization assay in peripheral leukocytes and a low-dose adrenocorticotropin hormone stimulation test was performed before and after low-dose dexamethasone (DEX) treatment for 14 days. The glucocorticoid-responsive gene for metallothionein IIa (MTIIa) was also analyzed by a solution hybridization assay in peripheral leukocytes. RESULTS: Overall, basal GR mRNA levels were higher in patients than in controls (p < 0.0001). There were no significant differences between NRs and Rs. None of the groups down-regulated their GR mRNA levels in response to DEX treatment. Basal and stimulated cortisol levels decreased significantly only among NRs after DEX (p = 0.012 and 0.0093). MTIIa levels were lower in NRs as compared with Rs, both in mononuclear (p = 0.0059) and in polynuclear leukocytes (p = 0.030). CONCLUSION: Patients with UC in remission exhibit higher levels of GR mRNA in peripheral leukocytes. We speculate that this may be secondary to an underlying up-regulation of proinflammatory factors also present in patients in clinical remission. Differences in GR mRNA levels per se thus may not be important for the ability of patients with UC to respond to GCS treatment. The hypothalamic pituitary adrenal axis was suppressed by low-dose DEX treatment only in NRs, possibly indicating that steroid-resistance is not a generalized phenomenon. Lower levels of MTIIa in NRs may indicate a diminished efficiency of GR regulation in steroid-refractory patients.

Adult↗

Evaluation of methods for endoscopic staging of nasal polyposis.

Endoscopy is needed for reliable evaluation of the treatment of nasal polyposis. In this study, we compared the reproducibility of various score systems for staging nasal polyposis and the inter-individual variations between investigators. The mass of the polyps was assessed by five methods, three new techniques (numbers 1, 2 and 3) and two established ones (numbers 4 and 5). These were: 1, lateral imaging projecting the extension of the polyps by drawing on a schematic picture of the lateral wall of each nasal cavity; 2, assessment of polyp obstruction estimating the proportion of the total nasal cavity volume occupied by polyps; 3, nasal airway patency--determining the relationship between the patient's patent airway lumen and an imaginary maximal nasal airway lumen; 4, a score system with four steps ad modum Lildholdt et al.--determining their relationship to fixed anatomical landmarks; and 5, a score system with three steps ad modum Lund and Mackay--determining their relationship to the middle meatus. High correlations were found between the first and the second assessments by a given investigator with all five methods used to score nasal polyposis. High correlations were also shown between the various methods. When three investigators examined a given patient, there were no significant differences between the investigators using score systems 1, 3 and 4. However, with score systems 2 and 5, there was insufficient agreement between the investigators. The patient's symptom of nasal blockage was not a good indicator of the size of the polyps, especially as regards small polyps. Two of the best methods tested (1 and 4) were selected for further clinical studies regarding evaluation of the sensitivity of score systems to detect changes in polyp size during treatment.

Adult↗

Labeling of the glucocorticoid receptor and Na,K-ATPase in a rat otitis media model.

HYPOTHESIS: Glucocorticoid hormones exert an influence on the inflammatory response of the middle ear during acute otitis media. Rats with experimentally induced purulent otitis media were given either glucocorticoid hormones in excess or a glucocorticoid hormone blocker that deprived the animals of the hormone. BACKGROUND: Acute otitis media is a common inflammatory disease among children. Streptococcus pneumoniae is the most usual causative agent. The standard treatment today is phenoxymethylpenicillin. The role of glucocorticoid hormones in inflammatory reactions in the middle ear has been widely debated. METHODS: In an otitis media model, a suspension of pneumococci was inoculated into the bulla of the rat, after the animals were pretreated with either a dose of corticosteroid hormones or the glucocorticoid receptor blocking agent RU 486. Rats with induction of otitis media only, but no pretreatment, were used as control subjects, as were the left control-operated ears of all rats. The inflammatory response in the inner ear and in the middle ear was evaluated. The presence of glucocorticoid receptors and the enzyme Na,K-ATPase was investigated with immunohistochemistry. RESULTS: The inflammatory response in the animals with untreated otitis media and in the group with otitis media in rats pretreated with the receptor blocker was much more extensive than in the group of animals pretreated with corticosteroids. In the corticosteroid-treated group, the tympanic membrane and the mucous membrane of the middle ear were less edematous, but the middle ear cavity contained more pus. Only a few lymphocytes were found in the inner ears of these rats. When the inner ear was labeled with antibodies against glucocorticoid receptors, there seemed to be no difference between the labeling patterns in the three groups. This was also the case for antibody labeling against Na,K-ATPase. CONCLUSION: The present results indicate that the reaction in the middle ear mucous membrane is more pronounced in rats that had been pretreated with the hormone receptor blocking drug. An increase of corticosteroid hormone levels during the inflammatory process seem to diminish the reaction in the tympanic membrane and the middle ear mucosa. Neither the hormone receptor blocking drug nor the steroid hormones change the content of glucocorticoid receptors and Na,K-ATPase in the inner ear in the otitis media rat model.

Acute Disease↗

Treatment with dexamethasone arrests the development of myringosclerosis after myringotomy.

HYPOTHESIS: To attempt to inhibit the development of myringosclerosis by intraperitoneal injection of dexamethasone. BACKGROUND: The authors' earlier report showed that the development of myringosclerosis after myringotomy was associated with an inflammatory reaction. The present study was performed to secure evidence for this hypothesis. METHODS: Three groups of bilaterally myringotomized rats were treated at 12-hour intervals with intraperitoneal injection of dexamethasone, RU486 (a glucocorticoid receptor antagonist), and saline, respectively. At 6, 12, 24, and 48 hours after the myringotomy, 2 animals were anesthetized on each occasion and examined otomicroscopically. The animals were then killed, and the tympanic membranes were excised and prepared for light microscopic studies. RESULTS: Dexamethasone treatment retarded and diminished the development of sclerotic lesions markedly. Moreover, no inflammatory signs were seen in the flaccida specimens. When the RU486-treated animals were compared with the animals in the control group, there were no evident differences concerning the development of myringosclerosis or the extent of the inflammatory reaction. CONCLUSION: These findings confirm the earlier hypothesis that an inflammatory reaction in collagen tissue is involved in the mechanism that causes the development of myringosclerosis.

Animals↗

In vivo modulation of glucocorticoid receptor mRNA by inhaled fluticasone propionate in bronchial mucosa and blood lymphocytes in subjects with mild asthma.

BACKGROUND: In vivo regulation of the glucocorticoid receptor (GR) by glucocorticoids provides a means of modulating sensitivity of targeted cells. OBJECTIVE: We sought to determine the in vivo modulation of GR mRNA expression by fluticasone propionate (FP) in subjects with mild asthma. METHODS: Ten atopic asthmatic subjects were treated with FP 250 microg twice daily for 4 weeks. Before and after treatment, the patients underwent fiberoptic bronchoscopy with endobronchial biopsy and sampling of venous blood for measurements of GR mRNA levels. A solution hybridization assay was used for quantitative analysis of GR mRNA. In addition, a 24-hour urinary cortisol excretion and an adrenocorticotropic hormone test before and after treatment with FP were performed. RESULTS: A high interindividual variation in GR mRNA expression was seen. However, we detected a significant reduction of the GR mRNA levels in the endobronchial biopsy specimens after FP treatment (36.6 +/- 23.1 and 25.0 +/- 10.9 amol GR mRNA/microg RNA, respectively; P <.01). In the peripheral blood lymphocytes an even more striking downregulation of the GR by its cognate ligand was documented (30.3 +/- 26.5 and 8.8 +/- 5 amol GR mRNA/microg RNA, respectively; P <.001), possibly reflecting differences in glucocorticoid sensitivity between tissues. A small but significant reduction of the 24-hour urinary cortisol excretion was observed (233 +/- 109 and 157 +/- 66 nmol/L, respectively; P <.01), whereas the feedback regulation of glucocorticoid synthesis by means of the hypothalamic-pituitary-adrenal axis as assessed by the adrenocorticotropic hormone test remained normal after treatment with FP. CONCLUSION: The results in this study confirm the potency of the inhaled corticosteroid FP and provide evidence for a considerable tissue-specific interindividual variation in the expression of the GR.

Adrenocorticotropic Hormone↗

Regeneration of nerve fibres in the maxillary sinus mucosa after experimental surgery. An immunocytochemical double-labelling study in the rabbit.

Nerve fibre regeneration in the maxillary sinus mucosa after surgery was studied in 10 New Zealand White rabbits. Four and 8 weeks following unilateral removal of the mucosa, the animals were fixed by perfusion, and the nose-sinus complexes were frozen and cut on a cryostat equipped with a tungsten-hardened knife. A double-labelling immunocytochemical procedure was developed with commercially available antibodies to protein gene product (PGP) 9.5 and tyrosine hydroxylase (TH) or neuropeptide Y (NPY). The study revealed that the maxillary sinus mucosa in rabbit is reinnervated at 4 and 8 weeks postoperatively. Furthermore, the regenerated lamina propria showed increased TH immunoreactivity (TH-IR) and NPY-IR, compared with the contralateral, non-operated side. Many of the fibres were seen in close proximity to newly formed vessels. These findings add further to the explanation of the altered vasoreactivity found earlier in regenerated sinus mucosa 1 month after surgery. This study also showed that demineralization of the nose-sinus complexes is not necessary if a hardened metal knife is used.

Adrenergic Fibers↗

Microvasculature, blood flow, and vasoreactivity in rabbit sinus mucosa after surgery.

OBJECTIVES: To study the circulatory integrity of the sinus mucosa following surgery, the vascular anatomy, blood flow, and vasoconstrictor response of the regenerated microcirculatory network were analyzed. STUDY DESIGN: Forty-six New Zealand White rabbits were operated on unilaterally with either a modified radical operation (MRO) or middle meatal antrostomy (MMA), using the nonoperated sinus for control purposes. After surgery, the animals were left to heal for 1 month. METHODS: Vascular casts were prepared with a low-viscosity methyl methacrylate resin and studied by scanning electron microscopy. Blood flow was measured by means of radiolabeled microspheres (tin 113 [113Sn]). The vasoconstrictor response to oxymetazoline at increasing concentrations was measured with laser Doppler flowmetry. RESULTS: The number of vessels increased significantly in the regenerated mucosa. The vascular casts displayed a rich microcirculation with local signs of angiogenesis. However, there was no difference in blood flow between the operated cavities and their control sides. Following MRO the regenerated mucosa was more sensitive to the vasoconstrictor effect of oxymetazoline, compared with the control side. This difference was not evident in the MMA-operated sinuses. CONCLUSIONS: In this model, surgery does not seriously interfere with the sinus blood flow, although the regenerated mucosa did display an altered vasoreactivity. These findings should be considered in relation to the effects of surgery intended to limit local inflammation and to ensure the ventilation of the sinuses.

Animals↗

Experimental nasal intubation: a study of changes in nasoantral mucosa and bacterial flora.

OBJECTIVES: To investigate the local effects in a nasal cavity and its adjacent sinuses of long-term detention of an endonasal tube, with special attention to inflammatory pathology and microbiology. STUDY DESIGN: Experimental rabbit study. METHODS: Four groups of 4 rabbits, in all 16, were unilaterally nasally intubated and evaluated macroscopically, histopathologically, and bacteriologically after 1, 2, 4, and 8 weeks, respectively. RESULTS: At first, in the 1- and 2-week groups to the 4-week group, histopathology, such as degeneration of olfactory mucosa, squamous cell metaplasia, and polyp formations, was observed together with frequent opportunistic bacterial findings in the nasal cavity. Later, in the 4- and 8-week groups, inflammatory mucosal changes, such as septal increase of connective tissue, goblet cell hyperplasia, and epithelial invaginations, were found in the nasal cavity containing a tube. A concomitant increase was found of commensal bacteria adjacent to the tube and the similar bacterial findings in the ipsilateral maxillary sinuses. However, there were no signs of inflammatory reactions in the sinuses. CONCLUSIONS: Our investigation points to the tube as the cause of local goblet cell hyperplasia with an increased mucus production, and as a food source for the commensals with a marked increase of the amount of bacteria. The positive bacterial cultures from the maxillary sinuses might be considered to be colonization. However, because of the possibility of contamination, improved sampling techniques are required, as are further studies.

Animals↗