Karl Magnus Westrin

Recurrent primary pleomorphic adenomas of salivary gland origin

The rate of tumor recurrence after surgery for benign salivary gland pleomorphic adenoma varies considerably in different clinical settings and seems to depend to a great extent on the surgical technique used. The importance of tumor spillage for subsequent recurrence has recently been questioned. The current follow‐up study was undertaken to ascertain whether intrasurgical rupture, tumor spillage, or any histopathologic feature might have had an impact on the rate of recurrence.

Experimentally induced polyps in the sinus mucosa : a structural analysis of the initial stages

To document polyp formation in the sinus mucosa, the authors of this study subjected New Zealand white rabbits to different modes of manipulation intended to induce inflammation of the maxillary sinus. These manipulations included a combination of bacterial infection and mechanical trauma, the deposition of agarose into the sinus cavity, and the deposition of N‐formyl‐methionyl‐leucyl‐phenylalanine, a chemotactic peptide, into the sinus cavity. A majority of animals developed polyps, which were examined by light and electron microscopy.

Nasal Polyps in Cystic Fibrosis: Clinical Endoscopic Study With Nasal Lavage Fluid Analysis

STUDY OBJECTIVES Nasal polyps frequently appear in patients with cystic fibrosis (CF). The aims of this study were to focus on what problems (symptoms, endoscopic findings, and laboratory correlates) nasal polyps cause the CF patient, and how these correlate to the total health situation of this patient group. PATIENTS AND STUDY DESIGN The clinical histories, endoscopic investigations of the nasal cavity, and analyses of nasal lavage fluid of 44 patients with CF complicated with nasal polyposis have been compared with those of 67 CF control subjects. The patients were examined at annual control examinations (with pulmonary tests, working capacity, liver tests, and bacterial and blood tests) from 1995 to 1996 at Stockholm Cystic Fibrosis Center, Huddinge University Hospital. All patients were > 2 years of age. The endoscopic findings were related to the actual pulmonary function, inflammatory blood parameters, colonizing pathogens, antibodies (Staphylococcus aureus and Pseudomonas aeruginosa), and genotype. RESULTS The patients with nasal polyps differed with respect to chronic colonization of P aeruginosa in sputum samples and had a higher occurrence of serum antibodies against the same species. The two groups did not differ in pulmonary functions, inflammatory parameters, or genotype. The polyps found were mainly small (within the meatus media) and gave no significant increase in ongoing clinical symptoms such as rhinorrhea, nasal obstruction, or hyposmia. Neither was any significantly marked finding concerning the nose (mucosal swellings, secretion, etc.) made in the polyp patients. The patients with CF scored slightly lower in a smell identification test in comparison with the healthy control group. The nasal lavage fluid was analyzed (in 93 of the 111 patients) for the occurrence of P aeruginosa (by polymerase-chain reaction [PCR]), interleukin [IL]-5, IL-8, and lysozyme. The lysozyme and IL-8 content was equal in the two CF groups but increased in comparison with the healthy control group. P aeruginosa was not detected with PCR in any nasal lavage fluid. No measurable levels of IL-5 in the nasal lavage were found. CONCLUSIONS There was a higher frequency of chronic colonization of P aeruginosa in the lower respiratory tract in patients with nasal polyps. Otherwise, nonsevere nasal polyposis was not an indicator of lower respiratory tract morbidity in CF patients.

Experimental maxillary sinusitis induced by Bacteroides fragilis. A bacteriological and histological study in rabbits.

Experimental anaerobic maxillary sinusitis was induced in New Zealand White rabbits by blocking the ostium and inoculating Bacteroides fragilis, strain NCTC 9343. The animals were examined histologically and bacteriologically after 5 days, and 2, 3 and 4 weeks. All the infected sinuses displayed signs of moderate or severe inflammation throughout the study period. Ciliary damage and desquamation, hyperplasia and metaplasia of the epithelium were characteristic features. Furthermore, heavy leukocyte- and, particularly, round cell-infiltration, fibrosis, periosteal hyperplasia and bone degradation and -formation were also frequently encountered. The secretory cell count in the epithelium increased, including the regeneration of goblet cells. After 4 weeks no obvious recovery could be seen, and the inducing microorganism was re-isolated in the majority of cases. In comparison with experimental pneumococcal sinusitis, the B. fragilis infection exerts a more prolonged and severe inflammation.

Formation of Mucosal Polyps in the Nasal and Maxillary Sinus Cavities by Infection

Unilateral maxillary sinusitis was experimentally induced in New Zealand White rabbits with Streptococcus pneumoniae serotype 3, Bacteroides fragilis NCTC 9343, and Staphylococcus aureus V8. In another group of rabbits, sinusitis was induced by blocking of the sinus ostium only. Bacteriologic and light microscopic analysis was performed after 5 days to 1 month. Granulation-like polyps developed after deep mucosal inflammatory trauma initiating fibroblast proliferation, angiogenesis, and epithetlial migration to cover the polyp. In regions of a more superficial trauma—characterized by epithetlial desquamation and fibroblast growth—proliferation and differentiation of basal cells resulted in the formation of microcavities dissecting off edematous polyps. Polyps could be found in all sinusitis groups, irrespective of inducing agent. The cellular events of polyp formation appear to be the result of a continuous inflammatory reaction and are not directly related to the presence of a certain microorganism. Instead, the potential of any microorganism to induce a deep mucosal trauma or epithelial desquamation seems essential for its ability to initiate polyp formation. (OTOLARYNGOL HEAD NECK SURG 1993;109:522-9.)

The Inflammatory Response of the Sinus and Nasal Mucosa During Sinusitis: Implications for Research and Therapy

Since it is difficult to evaluate the state of an infected sinus mucosa by histopathology, much of the present knowledge of the morphology in sinusitis is based on animal experiments. When experimental sinusitis is induced in the rabbit, the inflammatory response in the nose appears to be more pronounced than that in the maxillary sinus. In the animal model, histological findings include epithelial desquamation, edema, goblet cell hyperplasia and, in severe cases, fibrosis, bone reaction and formation of polyps in the nose and in the antrum. These local pathological findings may persist in the nasal middle meatus and the paranasal sinuses for a considerable time and predispose the mucosa to recurrences of infection. By investigation with recently introduced advanced techniques such as magnetic resonance imaging (MRI), a protracted pathological state in the sinus mucosa can be recorded also in humans for months after an episode of acute sinusitis. Future human and experimental studies of the local inflammatory response and of the cellular pathology over time will yield further guidelines for improved therapy and prevention of acute sinusitis.

Mucosal Pathology of the Nose and Sinuses: A Study in Experimental Maxillary Sinusitis in Rabbits Induced by Streptococcus Pneumoniae, Bacteroides Fragilis, and Staphylococcus Aureus

Unilateral maxillary sinusitis was experimentally induced in New Zealand White rabbits with Streptococcus pneumoniae serotype 3, Bacteroides fragilis NCTC 9343, and Staphylococcus aureus V8 in order to study possible differences in the inflammatory response of the sinus and nasal mucosa at different time-intervals during a 12-week period of infection. The initial sinus mucosal response, most pronounced in pneumococcal sinusitis, was characterized by leukocytosis, epithelial desquamation, and squamous cell metaplasia. Tissue reactions at later intervals included fibrosis of lamina propria, gland involution, polyp formation, and bone remodelling, and were most pronounced in S. aureus and B. fragilis sinusitis. The nasal mucosa was altered with a redistribution of goblet cells, development of polyps in the ethmoidal region, involution of Bowmans glands and locally, areas of degenerated olfactory sensory epithelium. These findings endorse that the degree of local pathology depends on the infecting microorganisms specific pathogenetic factors. However, local tissue factors guiding the cellular inflammatory proliferative and regenerative processes are also of fundamental importance for the type of pathological changes occurring in an infected nasal or sinus mucosa.

Mucosal Fine Structure in Experimental Sinusitis

Rabbit maxillary sinuses were inoculated with Streptococcus pneumoniae and Bacteroides fragilis, and the histologic response in the sinus mucosa was observed over a 12-week period. An increased height of the cylindric cells and hyperplasia of the basal cells were frequent findings irrespective of the pathogen inoculated. The disease was found to influence the character of the secretory product from epithelial secretory cells and to degranulate the subepithelial glands. Ciliary loss was a transitional finding. A reduction in the number of mitochondria, the occurrence of deformed short microvilli, and cytoplasmic blebbing were seen in the cells devoid of normal cilia. It is inferred from this study that pneumococcal sinusitis in rabbits is a self-limiting process, and the mucosal sequelae of the acute infection are persisting goblet cells, slight focal fibrosis, and edema. Inoculation with B fragilis produces a chronic inflammatory process, with infiltration of mononuclear cells, luminal dilatation of the glands exhibiting zymogen granule depletion, and an increased thickness of the whole mucosal layer.

Induction, Course, and Recovery of Maxillary Sinusitis: A Bacteriological and Histological Study in Rabbits

A bacteriological and histological study of acute pneumococcal sinusitis in rabbits was performed. The sinus ostium was blocked unilaterally and on the second day 108 Streptococcus pneumoniae type 3 were injected into the sinus cavity. The bacteriology of the sinus secretion and the morphological alterations of the sinus mucosa was determined 1, 2, 3 and 4 weeks after initiation of infection. Initially a pronounced mucosal infiltration of granulocytes and lymphocytes was found. Squamous cell metaplasia as well as areas of desquamated epithelium were also evident. This heavy inflammatory reaction gradually declined and after 4 weeks the epithelium appeared more normal, although goblet cells and subepithelial thickening, both associated with a more chronic infection, were found in certain areas. After 2 weeks, the initially reisolated pneumococci were replaced by a nonfermentative Gram-negative flora as well as anaerobic bacteria.

Expression of P-Glycoprotein 170 in Nasal Mucosa may be Increased with Topical Steroids:

The synthesis of P-glycoprotein 170 (P-gp), a “multidrug resistance” protein capable of extruding various drugs including 11-OH steroids from human cells, can be upregulated by certain glucocorticosteroids. This study demonstrates the presence of P-gp in the columnar surface epithelium and in glandular acini of healthy nasal mucosa with immunohistochemical technique. Furthermore, nasal polyps from 5 of 17 patients treated with clinical doses of a topical nasal steroid, budesonide, appear to show a stronger staining intensity for P-gp than polyps from 13 untreated patients. This suggests the possibility of local P-gp gene induction by topical glucocorticoid treatment. Upregulation of P-gp synthesis appears as a new possible cause of relative resistance to topical steroid medication in patients with nasal inflammatory disease.