Photosensitizer With Illumination Enhances In Vivo Antitumor Effect of Anti-ROBO1 Immunotoxin on Maxillary Sinus Squamous Cell Carcinoma

BACKGROUND/AIM

Head and neck squamous cell carcinoma (HNSCC) is one of the most common types of cancer worldwide. Our study focused on the axon guidance receptor roundabout guidance receptor 1 (ROBO1) as a target for monoclonal antibody therapy of HNSCC. We previously showed that saporin-conjugated anti-ROBO1 (B5209B) immunotoxin (IT-ROBO1) enhanced cytotoxic effects on HNSCC cells in combination with the photosensitizer aluminum phthalocyanine disulphonate (AlPcS2a) and illumination. We examined the effects of this combination therapy in a mouse xenograft model.

MATERIALS AND METHODS

IT-ROBO1 was intraperitoneally administered to HSQ-89 (derived from Japanese maxillary sinus squamous carcinoma, RCB0789; RIKEN, Tsukuba, Japan) xenografted mice. After 3 days, AlPcS2a was injected subcutaneously around the tumor and the area was illuminated at 650 nm for 30 min. The growth of the tumor was evaluated and the effects on the tumor were examined.

RESULTS

Pronounced anti-tumor effects were elicited by the administration of IT-ROBO1 and AlPcS2a with light illumination on tumor size and pathological characteristics.

CONCLUSION

The results showed that photosensitizer treatment with illumination robustly enhanced the antitumor effect of the IT-ROBO1 immunotoxin.

Maxillary sinus floor elevation using Beta-Tricalcium-Phosphate (beta-TCP) or natural bone: same inflammatory response

Sinus elevation is a common procedure to increase bone volume in the atrophic maxilla to allow placement of dental implants. Autogenous bone is the gold standard but is limited in quantity and causes morbidity at the donor site. β-TCP is a synthetic biomaterial commonly used in that purpose. It appears to induce a poor inflammatory response. This study aimed to evaluate the degree of edema of the sinus mucosa after sinus lift surgery according to the type of biomaterial. Forty sinuses (20 patients) were included retrospectively and divided into 2 groups according to the biomaterial that was used: synthetic biomaterial (BTCP group), natural bone (BONE group). A control group (CTRL group) was constituted by the non-grafted maxillary sinuses. Twelve measurements per sinus were realized on pre- and post-operative computed tomography and averaged to provide the sinus membrane thickness value (SM.Th). SM.Th was thicker post-operatively in the BTCP and BONE groups in comparison with the CTRL group and in comparison with pre-operative measurements. No difference was found post operatively between the BTCP and BONE groups. We found that a synthetic biomaterial (β-TCP) induced the same degree of edema, and thus of inflammation, as natural bone. It constitutes therefore an interesting alternative to autogenous bone for maxillary sinus lifts.

Novel injectable strontium-hardystonite phosphate cement for cancellous bone filling applications

Injectable bone cement (IBC) such as those based on methacrylates and hydraulic calcium phosphate and calcium sulfate-based cements have been used extensively for filling bone defects with acceptable clinical outcomes. There is a need however for novel IBC materials that can address some of the inherent limitations of currently available formulations to widen the clinical application of IBC. In this study, we characterized a novel hydraulic IBC formulation consisting of bioactive strontium-doped hardystonite (Sr-HT) ceramic microparticles and sodium dihydrogen phosphate, herein named Sr-HT phosphate cement (SPC). The resultant cement is comprised of two distinct amorphous phases with embedded partially reacted crystalline reactants. The novel SPC formulation possesses a unique combination of physicochemical properties suitable for use as an IBC, and demonstrates in vitro cytocompatibility when seeded with primary human osteoblasts. In vivo injection of SPC into rabbit sinus defects show minor new bone formation at the SPC periphery, similar to those exhibited in sinus defects filled with a clinically available calcium phosphate cement. The current SPC formulation presented in this paper shows promise as a clinically applicable IBC which can be further enhanced with additives.

[The staphylococcal enterotoxin burden determines the ultrastructure of ciliated epithelia and inflammatory changes in maxillary sinus mucosa of rabbits]

OBJECTIVE

To investigate the ultrastructure of ciliated epithelia and inflammatory changes upon repeated exposure to staphylococcal enterotoxin A (SEA) of different concentrations in the maxillary sinus mucosa of rabbits.

METHODS

The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEA group and high-dose SEA group. The low-dose SEA group and high-dose SEA group received daily injections of 0.6 ng of SEA (2 ml) and 60 ng of SEA (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as control. Six rabbits chosen randomly in two groups were examined by computed tomography (CT) scans and then sacrificed to obtain the sinus mucosa from the two-side of maxillary sinuses for histological assessment on days 3, 7, 14 and 28. To characterize the inflammatory changes of the sinus mucosa examined using light microscope, hematoxylin and eosin (HE) and toluidine blue staining was performed. Scanning and transmission electron microscopy were performed to observe ultrastructure of ciliated epithelia in the maxillary sinus mucosa. SPSS 13.0 software was used to analyze the data.

RESULTS

On days 14 and 28, CT images showed opacification of the left maxillary sinus in the high-dose SEA group. The percentage of epithelial disruption was (22.73 ± 5.72) % and (30.79 ± 4.30)% in the high-dose SEA group respectively, and were significantly greater than those in the low-dose SEA group (5.12% ± 1.98% and 5.38% ± 1.64%, q value was 10.079 and 19.132) and control group (4.08% ± 1.29% and 4.81% ± 1.62%, q value was 11.016 and 19.592, respectively, all P < 0.01). The subepithelial thickness in the high-dose SEA group was (113.34 ± 14.81)µm and (120.86 ± 12.35) µm respectively, and were significantly different from those of the low-dose SEA group [(71.08 ± 10.39)µm and (81.63 ± 9.32)µm, q value was 8.090 and 8.782] and control group [(37.45 ± 7.67)µm and (38.79 ± 7.68)µm, q value was 15.759 and 19.541, all P < 0.01]. Viewed under the electron microscope, loss of cilia was observed, a few compound cilia and cytoplasmic protrusion were found, an obvious stretching of the endoplasmic reticulum and an obvious turgescence of the mitochondria was also observed. However, in the low-dose SEA group on days 14 and 28, CT scan of the left maxillary sinus showed transparency; light microscopy observations of the maxillary sinus mucosa showed the number of eosinophils was markedly increased as compared with the high-dose SEA and control groups, the differences were significant (q value was 5.871 and 6.766 on day 14, and q value was 7.572 and 8.970 on day 28, respectively, all P < 0.05). But no significant differences were observed in epithelial disruption between the low-dose SEA and the control groups on days 14 and 28 (q value was 1.512 and 0.859 respectively, all P > 0.05); inordinate array and adhesion of cilia was observed, but cilia loss, compound cilia, cytoplasmic protrusions, mitochondrial swelling and endoplasmic reticulum stretching were not found.

CONCLUSIONS

SEA may induce allergic inflammation of the sinus mucosa without damaging the structure of ciliated epithelia at low concentration. Whereas SEA impairs the structure of mitochondria and endoplasmic reticulum in ciliated epithelial cells at high concentration, and results in cilia loss and epithelial disruption, which may be one of the main reasons to induce acute sinusitis.

[Effects of staphylococcal enterotoxin of different concentrations on the expression of GATA-3 and Th1/Th2 cytokines in the maxillary sinus mucosa of rabbits]

OBJECTIVE

The aim of this study was to determine the expression of GATA-3 and the level of Th1 and Th2 cytokines upon repeated exposure to staphylococcal enterotoxin B(SEB) of different concentrations in the maxillary sinus mucosa of rabbits.

METHOD

The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEB group and high-dose SEB group. The low-dose SEB group and high-dose SEB group received daily injections of 0.6 ng of SEB (2 ml) and 60 ng of SEB (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as a control. Six rabbits chosen randomly in two groups were killed on days 3, 7, 14, and 28, and to obtain the sinus mucosa from the two-side maxillary sinuses for measurement. Mucosal levels of IL-2, IL-4, IL-5, and IFN-γ were measured using ABC-ELISA. Tissue expression of GATA-3 were examined using Real-time PCR and immunohistochemistry.

RESULT

IFN-γ and IL-2 levels were significantly elevated in the high-dose SEB group compared with the low-dose SEB and control groups on days 7, 14, and 28 (P < 0.05). However, IL-4 and IL-5 levels were markedly enhanced in the low-dose SEB group compared with the high-dose SEB and control groups on days 14 and 28 (P < 0.05). Real-time PCR showed that the expression of GATA-3 mRNA in the low-dose SEB group was markedly enhanced, and immunohistochemical staining illustrated that the number of GATA-3 positive cells was markedly increased in the low-dose SEB group as compared with the high-dose SEB group (P < 0.05). No significant differences were observed in GATA-3 expression between the high-dose SEB and the control groups (P > 0.05).

CONCLUSION

SEB promoted Th1 cytokines production at high concentrations, and enhanced Th2 cytokines expression and Th2 immune response at low concentrations.

Effects of hepatocyte growth factor on wound healing of rabbit maxillary sinus mucosa

OBJECTIVE

The purpose of this study was to investigate the effects of hepatocyte growth factor (HGF) on healing of the sinonasal mucosa.

METHODS

A 6 mm wound was created in the bilateral maxillary sinuses of 16 New Zealand White rabbits, and 8 mm diameter absorbable gelatin sponge with 25 μL HGF (case) and 25 μL saline (control) were randomly assigned to each side for wound treatment. On the third and seventh days after the procedure, the average decreased diameter was recorded. On the seventh day, the medial wall of the maxillary sinus was taken for histologic analysis (including scanning electron microscopy of two rabbits). The maximal thickness of fibrous tissue and no epithelium coverage of the wound were detected. In the second, third, and fourth weeks, another 3 rabbits were randomly selected for photographs under a scanning electron microscope.

RESULTS

On the third and seventh days after injury, the average decreased diameters were 2.05 ± 0.56 mm and 1.56 ± 0.80 mm, 3.90 ± 0.76 mm, and 3.29 ± 0.70 mm on the case and control sides, respectively. On day 7 after injury, the maximal thickness of fibrous tissue was 324.8 ± 93.1 μm and 432.8 ± 106.3 μm, and the wound without epithelium coverage was 345.7 ± 114.6 μm and 508.6 ± 157.2 μm on case and control sides, respectively, and there were significant differences (p < .05).

CONCLUSIONS

HGF can promote wound healing and ciliogenesis and inhibit fibrosis in the maxillary sinus mucosa, especially in the first 3 days. This finding suggests that HGF plays a potential role in reepithelialization and cilium hyperplasia.

Accidental extrusion of sodium hypochlorite into the maxillary sinus

An unusual case is reported of accidental extrusion of sodium hypochlorite solution into the maxillary sinus during instrumentation in the course of root canal treatment of a maxillary premolar. This caused a burning sensation accompanied by nasal bleeding, swallowing of blood, and interrupted breathing. The case was managed by irrigating with sterile saline, arresting nasal bleeding, and administering antibiotics, anti-inflammatory drugs, and decongestants.

Rehabilitation of surgically traumatized paranasal sinus mucosa using retinoic acid

BACKGROUND

Paranasal sinus mucosa that regenerates after surgical stripping is characterized by sparse, dysmorphic cilia. Although such dysfunctional mucosal changes are thought to be irreversible, the potential rehabilitation of deciliated mucosa by topical therapies has not been explored. This study evaluated the effect of topical retinoic acid (RA) in rehabilitating deciliated sinus mucosa that has regenerated after surgical stripping.

METHODS

Twelve New Zealand rabbits underwent bilateral maxillary sinus mucosal stripping and were allowed to remucosalize for 10 days. In the first treatment arm (n = 6), 0.01% RA was applied to the regenerated mucosa of the left maxillary sinus and an aqueous control was placed contralaterally. In the second treatment arm, the regenerated mucosa was surgically restripped bilaterally before applying RA and control. After 14 additional days, mucosa was harvested and examined by scanning electron microscopy for ciliary density, orientation, and morphology.

RESULTS

In the first treatment arm, no significant differences in ciliary density, orientation, or morphology were noted between RA-treated sinuses and controls. In the second arm, RA-treated sinuses showed improved ciliary density, morphology, and orientation compared with controls.

CONCLUSION

RA does not appear to significantly enhance ciliogenesis when applied after mucosal regeneration has occurred. However, if deciliated mucosa is restripped and allowed to regenerate in the presence of RA, ciliary ultrastructural features may be enhanced. RA may have therapeutic value in rehabilitating deciliated sinus mucosa when applied before mucociliary differentiation of regenerating mucosa.

Histologic and Ultrastructural Analysis of Regenerated Bone in Maxillary Sinus Augmentation Using a Porcine Bone–Derived Biomaterial

BACKGROUND

The purpose of the present study was the histologic and ultrastructural evaluation of a biomaterial composed of cortical pig bone in the form of granules.

METHODS

After maxillary sinus augmentation using this biomaterial, 10 specimens were retrieved after 5 months in 10 patients using this biomaterial. The specimens were processed to be observed under light microscopy (LM) and transmission electron microscopy (TEM). Histomorphometric measurements were presented by means +/- standard deviations.

RESULTS

LM showed that most of the particles were surrounded by newly formed bone. In some areas, the osteoid matrix was present; however, mainly compact bone was present at the interface. There was no evidence of an acute inflammatory infiltrate. The newly formed bone was 36% +/- 2.8% and marrow spaces were 38% +/- 1.6%, whereas residual grafted material was 31% +/- 1.6%. Under TEM, all phases of bone formation (osteoid matrix, woven, and lamellar bone) were observed in proximity with the biomaterial particles. The bone-biomaterial interface showed a close contact between the porcine bone particles and the surrounding bone that had mainly features of mature bone with numerous osteocytes. A lamina limitans was sometimes present at this interface.

CONCLUSIONS

According to our knowledge, this is the first study presenting data on TEM of a porcine bone-derived biomaterial used in sinus augmentation procedures in humans. Our findings show that this is a biocompatible biomaterial that can be used for maxillary sinus augmentation procedures without interfering with the normal reparative bone processes.

Bisphosphonate-induced osteonecrosis of the jaws: a case report and literature review

Bisphosphonates are nonmetabolized analogues of pyrophosphate that are used for treating skeletal complications secondary to bone metastases. These drugs are capable of localizing to bone and inhibiting osteoclastic activity; however, their exact mechanisms of action remain unclear. Recently, it has been documented that administration of bisphosphonates has been associated with osteonecrosis of the jaws. This article details the case of a woman who received intravenous administration of bisphosphonate for metastatic breast cancer and subsequently developed osteonecrosis in both the maxillary and mandibular jaws.

Retrobulbar alcohol injection for orbital pain relief under difficult circumstances: a case report

INTRODUCTION

A case is presented of a patient with severe and chronic pain in the orbital region, which was relieved by retrobulbar injection of absolute alcohol. The management of chronic pain in the orbital region has received little attention and the literature is reviewed.

CLINICAL PICTURE

A 52-year-old man with adenoid cystic carcinoma of the maxillary sinus was suffering from severe pain, especially in the left orbital region. There was also pain from ocular exposure and compression caused by the tumour. Magnetic resonance imaging (MRI) revealed spread of tumour to both orbits, particularly on the left. Multiple debulking surgery and various treatment modalities offered no relief from his pain.

TREATMENT

A single retrobulbar injection of 2 mL of absolute alcohol, was placed into the putative orbital apex.

OUTCOME

As a consequence of the injection, he had complete resolution of his pain in the 6 months prior to his death.

DISCUSSION

Retrobulbar injection of alcohol offers effective pain relief in certain specific conditions characterised by chronic orbital pain when other treatments do not help.

CONCLUSION

We have demonstrated that the retrobulbar technique still has a place in our armamentarium.

Composition of hyaluronan affects wound healing in the rabbit maxillary sinus

BACKGROUND

Hyaluronan (HA) is a ubiquitous component of the extracellular matrix. HA and its derivatives have been used in the sinuses to reduce scarring and possibly promote wound healing. However, in recent animal studies, HA esters exhibited inflammatory effects. Mitomycin C (MMC) is another potential antiscarring treatment. This study prospectively evaluated the effects of three different HA constructs on wound healing in the rabbit maxillary sinus: (i) a novel cross-linked HA hydrogel, (ii) the cross-linked HA gel containing covalently bound MMC, and (iii) a commercially available woven HA ester (Merogel).

METHODS

Ostia were created with a 4-mm otologic drill in the maxillary sinuses of 15 New Zealand white rabbits with one side randomly chosen for treatment. After 14 or 21 days the size of the maxillary ostia were recorded and the tissue was examined under light microscopy.

RESULTS

Sinuses treated with the novel HA and HA-MMC hydrogels showed an increased ostial diameter compared with untreated controls. Woven HA ester-treated sinuses showed no improvement, with a trend toward a smaller ostium than controls. Histological examination showed that woven HA ester tended to cause increased fibrosis and granulomatous inflammation, and heterophilia was slightly increased in the HA hydrogel-treated sinuses. Blinded observation noted foamy macrophages surrounding the residual woven HA ester in each specimen while no similar reaction was noted near the residual HA or HA-MMC hydrogels.

CONCLUSION

This study suggests that the degree of ostial narrowing, inflammation, and fibrosis depends on the formulation of the HA used. Minimal, if any, additional benefit is seen with addition of MMC to the HA hydrogel in this pilot study.

A comparison between nitric oxide output in the nose and sinuses: A pilot study in one volunteer

From a study of nitric oxide (NO) output in the nose and sinuses it seems that: (i) the results obtained regarding the regulation of NO output in the nose do not necessarily apply to the sinuses; (ii) the results obtained for one group of sinuses may not apply to another; and (iii) NO output in the sinuses does not behave as one would expect if it serves to protect against infection.A pilot study was undertaken in one subject to determine whether the control of NO output in the nose differs from that in the sinuses.NO output was measured by aspirating different gaseous concentrations of oxygen (and/or carbon dioxide) through the nasal airways or punctured maxillary and frontal sinuses before and after i.v. administration of L-arginine (20 mg/kg). In the absence of gaseous oxygen in the nose or maxillary antrum, the effect of L-arginine on NO output was the same as that in the presence of oxygen. In the frontal sinus, the effect of L-arginine on NO output was blocked by the absence of gaseous oxygen. NO output in the nose and frontal sinus showed similar changes after either i.v. administration of L-arginine or removal of oxygen from the air. NO output in the maxillary antrum was virtually unaffected by either procedure. NO output in the nose was largely unaffected by the gaseous carbon dioxide content but that in the frontal and maxillary sinuses was profoundly inhibited by it. In both sinuses, suppression of NO output by carbon dioxide was countered by oxygen. Alterations in the oxygen or carbon dioxide content of the maxillary antrum did not alter NO output in the frontal sinus, or vice versa. After i.v. infusion of L-arginine, nasal NO output remained elevated for >1 h.

Early effect of exogenous Na hyaluronate on mucociliary clearance

BACKGROUND

An animal study is performed to determine the early effect of 1% Na hyaluronate on mucociliary clearance function.

METHODS

One percent of Na hyaluronate was introduced into the maxillary sinuses of rabbits by anterior antrostomy. A physiological solution of 1% NaCl was introduced into the maxillary sinuses of a control group to equalize the influence of Na for both groups. The treatment material was sprayed with an atomizer for coating the maxillary sinus lining. Technetium-99m diethylenetriamine pentaacetate dynamic scintigraphic imaging was performed to evaluate mucociliary clearance function on all rabbits 72 hours after the surgical procedure.

RESULTS

Although the mean rate of mucociliary clearance of the Na hyaluronate group was slightly worse than the control group; there was no statistically significant difference between them.

CONCLUSION

There is no early effect of exogenous 1% Na hyaluronate on mucociliary clearance function.

Localisation of osteogenic and osteoclastic cells in porous β-tricalcium phosphate particles used for human maxillary sinus floor elevation

We and others have shown earlier that porous beta-tricalcium phosphate (TCP) (Cerasorb) can be used in patients to augment the maxillary sinus floor prior to placement of oral dental implants. To better understand the transformation of TCP particles into bone tissue, we analyse here the appearance of cells with osteogenic or osteoclastic potential in relation to these particles. In biopsies taken at 6 months after sinus floor augmentation we observed bone growth into the TCP particles but also replacement by soft connective tissue. To identify possible osteoprogenitor cells in this tissue, histological sections were immunostained with an antibody to Runx2/Cbfa1, an essential and early transcription factor for osteoblast differentiation. The osteogenic potential of cells was further confirmed by immunostaining for bone sialoprotein (BSP) and osteopontin (OPN). Other sections were stained for Tartrate Resistant Acid Phosphatase (TRAP) activity to identify cells with osteoclastic capacity. Runx2/Cbfa1 positive connective tissue cells were found in abundance throughout and around the TCP particles, even at a distance of several millimetres from the maxillary bone surface. About 95% of the cells found within TCP particles stained positive for Runx2/Cbfa1. Fewer cells stained positive for BSP and OPN, suggesting more mature osteoblastic properties. Mono- and binucleate TRAP-positive cells, but no multinucleate TRAP-positive osteoclasts, were found in the soft tissue infiltrating the TCP and at the surface of the TCP particles. Both the Runx2/Cbfa1 positive and the TRAP-positive cells decreased apically with increasing vertical distance from the maxillary bone surface. This data suggests that the TCP particles attract osteoprogenitor cells that migrate into the interconnecting micropores of the bone substitute material by 6 months. The lack of large multinucleate TRAP positive cells suggests that resorption of the TCP material by osteoclasts plays only a minor role in its replacement by bone. Chemical dissolution, possibly favoured by a high cell metabolism in the particles, seems the predominant cause of TCP degradation. The abundance of Runx2/Cbfa1 positive cells would indicate that with a greater time of healing there will be further bone deposition into these particles.

Sinus floor augmentation with simultaneous placement of dental implants in the presence of platelet-rich plasma or recombinant human bone morphogenetic protein-7

The aim of the present study was to evaluate the possible benefit of platelet-rich plasma (PRP) in sinus grafting as compared with recombinant human bone morphogenetic protein-7 (rhBMP-7). For this purpose, we performed a bilateral sinus augmentation with anorganic bovine bone and simultaneous insertion of a titanium screw implant in five miniature pigs. Six hundred microliters of PRP and 15%-vol. autologous bone, which was collected with a trap during preparation of the implant recipient site, were added to the right sinus and 420 microl rhBMP-7 to the left sinus. A polychrome sequential labeling was performed. The animals were sacrificed 6 weeks after surgery. Undecalcified ground sections were evaluated by microradiography, digitized histomorphometry and under fluorescent light. The mean bone-implant contact using rhBMP-7 was 45.8% and 5.7% under PRP (P=0.002). The mean height of newly mineralized bone in the augmented area using rhBMP-7 amounted to 8.3 mm as opposed to 3.6 mm under PRP (P=0.013). Using PRP, the mean area of the newly formed bone was enhanced (51.3%) as compared with rhBMP-7 (33.1%); however, this difference was not statistically significant (P=0.081). In conclusion, under the selected experimental conditions the use of rhBMP-7 led to superior outcomes with regard to the osseointegration of dental implants and the height of new bone as compared with the use of PRP.

Effect of WEB 2170 BS, platelet activating factor receptor inhibitor, in the rabbit model of sinusitis

Platelet activating factor (PAF), a potent inflammatory mediator, is a biologically active phospholipid. Recent studies have shown that PAF may play an important role in the pathogenesis of inflammation. WEB 2170 BS has been shown to be a PAF antagonist both in vitro and in vivo. Nitric oxide (NO) is present in the mammalian nasal airways and originates primarily from the paranasal sinuses. Measurement of NO is thought to be a surrogate marker of upper airway inflammation. In this study, the antiinflammatory effects of WEB 2170 BS were investigated in a rabbit model of sinusitis. To induce experimental sinusitis, we applied killed Staphylococcus aureus percutaneously to the maxillary sinus of rabbits without occlusion of the natural ostium. Either WEB 2170 BS solution or placebo was administered intraperitoneally 2 hours before sinus inoculation, and this procedure was repeated twice daily for 4 days. The outcome of the treatment was determined by the measurement of NO metabolite levels and NO synthase activity in the samples of sinus mucosa and by histopathologic evaluation of sinus mucosa. The pathological grading was determined by the number of inflammatory cells found in the sinus mucosa. The levels of NO metabolites and NO synthase activity were found to be significantly lower in the WEB 2170 BS-treated group than in the control group. Histopathologic analysis of the sinus mucosa indicated decreased inflammation in the treated group as compared to the controls. These results demonstrate that WEB 2170 BS may produce significant anti-inflammatory effects in this model of sinusitis.

Paranasal sinus mucosal regeneration: the effect of topical retinoic acid

BACKGROUND

Paranasal sinus mucosa may suffer morphological and functional alterations as a result of surgical trauma. Mucosal stripping typically yields regenerated mucosa characterized by fibrosis, inflammatory infiltrate, and dysmorphic or absent cilia. The aim of this study was to determine the effect of topical retinoic acid (vitamin A) on regeneration of paranasal sinus mucosa.

METHODS

Both maxillary sinuses of 12 New Zealand white rabbits were surgically opened and stripped of mucosa. Six rabbits received 0.01% topical retinoic acid gel treatment to the stripped left maxillary sinus (low concentration group). The remaining six rabbits received 0.025% topical retinoic acid gel to the stripped left maxillary sinus (high concentration group). The stripped right maxillary sinus of all 12 rabbits served as the operated, untreated control to reflect the normal healing process. Six other animals served as unoperated controls. The sinus mucosa was examined by light microscopy after 14 days.

RESULTS

Untreated regenerated mucosa showed expected changes of submucosal gland loss, basal lamina and lamina propria fibrosis, cellular atypia, and loss of cilia. Topical retinoic acid treatment appeared to result in better mucosal regeneration marked by less cellular atypia and fibrosis. Although the regenerated mucosa was still grossly abnormal, the degree of ciliary loss and cellular derangement was reduced. The lower-concentration retinoic acid group had more favorable morphology than the higher-concentration retinoic acid group, and both were improved when compared with no treatment.

CONCLUSIONS

In a rabbit model, topical vitamin A in the form of retinoic acid gel appears to enhance regeneration of ciliated paranasal sinus mucosa. This preliminary study suggests that topical retinoids may have applicability in promoting sinus wound healing.

[Effect of staphylococcal enterotoxin B on ion electrophysiology and permeability in rabbit maxillary sinus epithelium]

OBJECTIVE

To study the barrier role of staphylococcal enterotoxin B (SEB) in rabbit maxillary sinus mucosa.

METHODS

Rabbit maxillary sinus mucosal membrane was dissected under a surgical microscope. The short-circuit current (Isc), conductance (G) and its permeability to horseradish peroxidase (HRP) were evaluated by employing Ussing chamber technique.

RESULTS

The stimulation of SEB enhanced Isc, G and its permeability to HRP of sinus epithelial barrier. The same results were obtained by applying tumor necrosis factor alpha (TNF-alpha) to rabbit maxillary sinus. Increase in TNF-alpha level in sinus mucosa was observed by the stimulation of SEB. Those pathophysiological abnormalities of sinus mucosa were abolished by pretreatment with anti-TNF-alpha antibody.

CONCLUSION

The SEB has potential effects on rabbit maxillary sinus mucosal barrier, activates the immune cells in the mucosa, and plays certain roles in maxillary sinusitis.

Intrasinus administration of topical budesonide to allergic patients with chronic rhinosinusitis following surgery

OBJECTIVE

Whether instillation into the maxillary sinus of topical budesonide affected the immune response and improved allergic patients with chronic rhinosinusitis that had persistence of symptoms despite appropriate surgical intervention was assessed.

STUDY DESIGN

Double-blind placebo-controlled.

METHODS

Twenty-six patients with allergy to house dust mites who had previously had surgery and who had persistent symptoms of disabling rhinorrhea or pressure-pain resistant to oral antibiotics and intranasal corticosteroids were recruited. During the double-blind study, patients instilled 256 microg budesonide daily or placebo through an intubation device (maxillary antrum sinusotomy tube) into one of the maxillary sinuses for 3 weeks before clinical assessment and a second biopsy.

RESULTS

We found an improvement in the symptom scores in 11 of the 13 patients who received budesonide; we also found a decrease in CD-3 (P = .02) and eosinophils (P = .002), and a decrease in the density of cells expressing interleukin4 (P = .0001) and interleukin-5 messenger RNA (P = .006) after treatment.

CONCLUSION

Topical budesonide delivered through a maxillary antrum sinusotomy tube can control chronic rhinosinusitis that persists after surgery.

[Efficient antibiotic therapy in radical surgery on the maxillary sinus]

The study assessed efficiency of local antibiotic therapy with mupirocin and amoxicillin/clavulanate in 28 patients radically operated on the maxillary sinus (MS). Early after the operation, MS tamponing with a latex tampon was made. The tampon was filled with mupirocin for patients of group 1. In patients of group 2 and controls the tampon was sterile but in group 2 after the tampon removal postoperative maxillary washing was made with amoxicillin/clavulanate solution. The results of the study demonstrated high efficiency of local administration of mupirocin and amoxicillin/clavulanate and validity of bacteriological examination in planning antibiotic therapy early after surgery.

[Sinus floor augmentation with simultaneous implant insertion using recombinant human osteogenic protein-1]

INTRODUCTION

The purpose of this study was to examine whether the combination of an osteoinductive protein (recombinant human osteogenic protein-(rhOP-1 = bone morphogenetic protein-7) with natural bovine bone mineral (BioOss) would improve ossification and the bone-implant contact (BIC) in a sinus floor augmentation with simultaneous placement of implants.

MATERIAL AND METHODS

In this study, the maxillary sinus floors in five miniature pigs were augmented with 3 ml BioOss containing 420 micrograms rhOP-1 on the test side and 3 ml BioOss alone on the control side. At the time of augmentation a titanium implant (ITI) was inserted from a laterocaudal direction.

RESULTS

After 6 months of healing the sites of augmentation were removed and examined in non-decalcified sections by microradiography, fluorescence microscopy of sequentially labelled specimens and by histometry. On both sides, significant amounts of newly formed bone were observed. However, on the test sites, the BIC in the augmented area was 80.0% versus 38.6% on control sites. It can be concluded that the application of bone morphogenetic proteins caused a more rapid and enhanced osseointegration of simultaneously placed implants when compared to the bone substitute alone.

DISCUSSION

Therefore recombinant human osteogenic protein-1 delivered by natural bone mineral has the potential to become a clinical alternative for autogenous bone grafts in sinus floor augmentation.

Ultrastructural changes in platelet activating factor-induced epithelial damage in rabbit maxillary sinus mucosa

Platelet activating factor (PAF), a potent chemical mediator in inflammation and allergic reaction, has been thought to induce mucociliary inhibition and epithelial damage in the airway mucosa. However, several recent papers have reported that PAF may not readily damage the airway epithelium. The aim of this study was to elucidate the pathogenesis of PAF-induced epithelial damage in terms of ultrastructural changes. Sixteen micrograms of PAF (1 mL of 16 microg/mL) was administered into the maxillary sinuses of rabbits. The rabbits were divided into 2 groups according to time intervals, and the antral mucosa was taken 1 and 3 days after administration of PAF. The tissue was processed for routine transmission electron microscopy. No epithelial degeneration was observed other than platelet aggregation, red blood cell stasis, and swelling of the endothelial cells 1 day after administration of PAF. Migration of inflammatory cells into the perivascular connective tissue, infiltration of eosinophils into the subepithelial and intraepithelial spaces, and vacuolar degeneration of the epithelial cells with focal loss of cilia were seen 3 days after administration of PAF. In conclusion, PAF induced infiltration of eosinophils into the epithelium, and resulted in epithelial degeneration that varied according to the time interval. Our findings suggest that PAF may cause epithelial damage through a series of secondary events, probably due to cytotoxicity of eosinophils infiltrating the epithelium.

Active ion secretion and permeability of rabbit maxillary sinus epithelium, impact of staphylococcal enterotoxin B

The aim of this study was to investigate the impact of staphylococcal enterotoxin B (SEB), a model superantigen, on the physiologic functions of rabbit maxillary sinus epithelium. Rabbit sinus mucosae were separated under a surgical microscope and mounted in Ussing chambers to record short-circuit current, conductance, and permeability to horseradish peroxidase. The results showed that SEB evoked increases in sinus epithelial cell baseline short-circuit current, conductance, and permeability to horseradish peroxidase. When tumor necrosis factor-alpha (TNF-alpha) was added to the Ussing chambers, we got results similar to those obtained by SEB stimulation in vitro; the effects of SEB on sinus epithelial cells could be blocked by pretreatment with anti-TNF-alpha antibody. These results demonstrate that SEB is able to alter the function of sinus epithelial cells and to affect the capability of the epithelial defensive barrier, which may be mediated by TNF-alpha.

Xenon-enhanced computed tomography quantifies normal maxillary sinus ventilation

OBJECTIVE

The purpose of this study was to determine the applicability, safety, and normal parameters of a xenon-enhanced CT technique to quantify maxillary sinus ventilation.

PATIENTS AND METHODS

Nine healthy subjects inhaled a xenon-oxygen-air mixture through their noses while repeated CT scans were performed through the same section of their sinuses. Images were obtained every 1 to 3 minutes and analyzed to measure the density of the gas in the maxillary sinus as a function of time.

RESULTS

Individual nasal cavity time constants ranged from 0.5 to 18 minutes. Studies performed after decongestion showed poorer sinus ventilation.

CONCLUSIONS

The xenon-CT washin/washout technique is safe, effective, and gives representative data.

Saccharin test of maxillary sinus mucociliary function after endoscopic sinus surgery

OBJECTIVES

To determine the usefulness of the saccharin time (ST) test for evaluating the mucociliary function of the maxillary sinus after endoscopic sinus surgery (ESS) for chronic sinusitis.

STUDY DESIGN

METHODS

This study was conducted on 88 maxillary sinuses of 74 patients after ESS. The maxillary sinus fontanel was broadly opened via the middle meatus using an endoscope, and a saccharin granule was adhered to the bottom of the maxillary sinus mucosa The time until the patient recognized the sweet taste was recorded. Before the ST test, the bilateral maxillary sinuses were classified into the following four groups on the basis of the post-ESS severity of mucosal edema and swelling as revealed by endoscopic observation: normal (45 sinuses), mild mucosal edema and swelling (24), moderate mucosal finding (14), and severe mucosal finding or filling of the sinus with a polyp(s) (5).

RESULTS

The mean ST values in the normal group and the groups with mild, moderate, and severe mucosal edema and swelling were 35.7, 38.1, 63.6, and 88.0 minutes, respectively. Thus the ST increased with the post-ESS severity of the mucosal lesion. However, for the group with mild mucosal edema and swelling, scanning electron microscopic observation of three maxillary sinuses in which the ST exceeded 120 minutes and four sinuses in which the ST was 40 minutes revealed extensive cilia loss in the former sinuses, but not in the latter. A second post-ESS endoscopic observation was performed in 17 patients, revealing improvement in 11 sinuses, no change in 5 sinuses, and aggravation in 1 sinus (compared with the initial test). The ST test was also repeated, revealing that the ST became shorter in most of the endoscopically improved sinus group. However, a few sinuses showed a discrepancy between the change in the endoscopic findings and the ciliary function (ST).

CONCLUSION

Measurement of the maxillary sinus ST is a simple, accurate, and useful technique for assessing the post-ESS mucociliary function in conjunction with endoscopy, and the information gained can help in deciding subsequent therapy.

Comparison of the response to histamine challenge of the nose and the maxillary sinus: effect of loratadine

To study the response of the maxillary sinus to histamine provocation, we performed a double-blind, randomized, crossover trial during which nonallergic subjects without symptoms of rhinitis (n = 25) received either 10 mg loratadine or placebo once daily for a week and then underwent nasal challenge with histamine (3, 10, and 30 mg/ml) followed, 24 h later, by a maxillary sinus challenge while still receiving the medication. Nasal challenge with histamine led to significant increases in vascular permeability, reflex nasal secretions, sneezing, and other nasal symptoms. Sinus challenge resulted in significant increases in vascular permeability within the sinus cavity (P < 0.01) and some nasal symptoms but no significant change in reflex nasal secretions. The response of the sinus mucosa to histamine was lower in magnitude than that of the nose. Treatment with loratadine resulted in a significant inhibition of the histamine-induced changes in both nasal and sinus cavities. Our data suggest the lack of a sinonasal reflex response to histamine provocation of the maxillary sinus of nonallergic individuals.

Inadvertent injection of sodium hypochlorite into the maxillary sinus

A previously undocumented complication of root canal therapy is reported. A dilute solution of 5-10 mls sodium hypochlorite was inadvertently injected into the maxillary sinus during root canal therapy of a right upper second premolar (5). The patient developed acute, sudden, severe facial pain and swelling necessitating emergency admission to hospital and operative intervention under general anaesthesia. A diagnosis of acute chemical sinusitus was made, further management and discussion follow.

Nitric oxide is a regulator of mucociliary activity in the upper respiratory tract

The in vitro effects of the nitric oxide (NO) substrate L-arginine on ciliary beat frequency and the in vivo effects of the NO donor sodium nitroprusside (SNP) on mucociliary activity were investigated in the rabbit maxillary sinus mucosa with photoelectric techniques. L-Arginine increased ciliary beat frequency in vitro with a maximum response of 27.1% +/- 6.4% at 10(-3) mol/L, and this effect was reversibly blocked by pretreatment with the NO synthase (NOS) inhibitor N(G)-nitro-L-arginine, whereas D-arginine had no such effect. SNP increased mucociliary activity in vivo, the peak response of 36.8% +/- 4.2% being obtained at the dose of 30.0 microg/kg. No tachyphylaxis was observed after repeat challenge with SNP. The increase in mucociliary activity caused by SNP was largely unaffected by pretreatment with the calcium channel blocker nifedipine, the cyclooxygenase inhibitor diclofenac, and the cholinergic antagonist atropine. The nonselective beta-blocker propranolol delayed the peak response of SNP to 7 to 8 minutes after challenge, compared with 1 to 2 minutes after challenge in animals without pretreatment. The results show the NO substrate L-arginine and the NO donor SNP to have ciliostimulatory effects in vitro and in vivo, respectively. The occurrence of NOS production in the sphenopalatine ganglion and sinus mucosa of the rabbit was studied by immunohistochemistry for NOS activity or nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry. The latter is an indirect sign of neuronal NOS activity. Numerous NOS-containing cell bodies were seen in the sphenopalatine ganglion; in the sinus mucosa a moderate supply of thin NOS-immunoreactive nerve fibers was seen. Taken together, the morphologic findings and the functional results indicate NO to be a regulator of mucociliary activity in upper airways.

The effect of selective phosphodiesterase inhibitors on mucociliary activity in the upper and lower airways in vitro

Bronchodilatory substances such as the phosphodisterase inhibitor (PDE-I) theophylline stimulate mucociliary activity. With the introduction of selective PDE-Is it has become possible to study the functional importance of each phosphodiesterase enzyme (PDE) concerning the regulation of the ciliary beat. The effects of rolipram (inhibiting a cAMP specific PDE (PDE4), milrinone (inhibiting a cGMP inhibited PDE (PDE3)) and zaprinast (inhibiting a cGMP specific PDE (PDE5)) were investigated in in vitro preparations from the rabbit maxillary sinus and trachea. Ciliary beat frequency (CBF) was measured with a photoelectrical method. In sinus mucosa all three compounds accelerated CBF. Milrinone (10(-5) M) by 22.6 +/- 5.3% (n = 6; P < 0.01), rolipram (10(-5) M) by 29.7 +/- 5.7% (n = 7; P < 0.01), and zaprinast (10(-5) M) by 19.4 +/- 6.3% (n = 6; P < 0.05). In the tracheal specimens at a concentration of 10(-5) M, milrinone accelerated CBF by 27.5 +/- 9.0% (n = 7; < 0.05), rolipram by 11.6 +/- 2.8% (n = 6; P < 0.05) and zaprinast by 24.3 +/- 5.3% (n = 7; P < 0.01). Comparison of the effects in the upper and lower airways showed that at concentrations of 10(-5) and 10(-4) M rolipram was more effective in the upper than in the lower airways. The reverse was true of milrinone which concentrations of 10(-7) and 10(-6) M had a significant effect in tracheal specimens but not in sinus specimens. Zaprinast was equally effective in both the upper and lower airways. It is concluded that in both the upper and lower airways selective PDE-Is have an accelerating effect on the CBF that may be beneficial in the treatment of airway diseases.

Sinus surgery: does mitomycin C reduce stenosis?

This experimental study investigates the effect of mitomycin C (MMC) on sinus mucosal healing. MMC has an antiproliferative action on fibroblasts. It is used in glaucoma surgery to prevent restenosis of fistulas. Antrostomies were drilled in rabbit maxillary sinuses. One side was used as a control and the other treated with MMC at a concentration of 0.04, 0.4, or 1 mg/mL. Two animals from each group were sacrificed at 1, 2, 4, and 12 weeks. The antrostomies in the control and 0.04-mg/mL groups had closed by 1 week; in the 0.4-mg/mL group by 4 weeks, and in the 1.0-mg/mL group by 12 weeks. Ciliary function was initially impaired but normalized within 1 week. Both light and scanning electron microscopy showed no permanent damage to the cilia. These results suggest that MMC can be used to delay closure of antrostomies in sinus surgery.

A new animal model for maxillary sinus floor augmentation: evaluation parameters

This study describes a novel animal model of the maxillary sinus floor augmentation procedure used to assess bone formation during 12 weeks in response to a recombinant human bone morphogenetic protein-2 (rhBMP-2)/absorbable collagen sponge (ACS) sinus implant. A buffer-ACS implant was used as a control. Animal response was monitored using computerized tomography and physical, hematologic, gross pathologic, and histologic evaluations. The rhBMP-2/ACS implants maintained a relatively constant size postsurgery and showed a time-dependent increase in mineralization. The buffer/ACS control implants failed to mineralize and were resorbed by 4 weeks. The model served effectively and without complication. Results indicate rhBMP-2/ACS implants deserve consideration as alternatives to traditional grafting procedures.

Effects of endothelins 1, 2 and 3 on mucosal blood flow in the upper airways

The three endothlins 1, 2 and 3 (ET-1, ET-2 and ET-3) are 21-amino-acid peptides which in a previous study in the rabbit have been shown to increase both mucociliary activity in the maxillary sinus in vivo and ciliary beat frequency (CBF) in sinus and tracheal samples in vitro. We have also demonstrated positive immunohistochemical staining for endothelin in the epithelium of samples from both maxillary sinus and trachea. The aims of the present investigation were to study the effects of the three endothlins on mucosal blood flow in the maxillary sinus of rabbits and the nasal mucosa of humans. ET-1, ET-2 and ET-3 decreased mucosal blood flow in the maxillary sinus of rabbits measured in vivo with laser Doppler flowmetry (LDF). Significant dose-response relationships were established for all endothelins. A comparison of the regression lines of the dose-response relationships for ET-1 and ET-2 did not show any difference, whereas the regression line of the dose-response relationships for ET-3 differed significantly. Maximum effect was seen at 50.0 pmol/kg ET-1, which reduced blood flow by -74.4 +/- 7.0%. Vasoconstriction became evident 30 s after administration of the endothelins, reached its maximum after 1 min and lasted 10 to 20 min. ET-1 induced stronger vasconstriction than ET-2 and ET-3 at equal dosage, except at 100.0 pmol/kg, where ET-2 had the same effect as ET-1. No tachyphylaxis was observed after repeated 10.0 pmol/kg-dose of ET-1. Similarly, there was no tachyphylactic effect on mucociliary activity in vivo in the maxillary sinus of rabbits after repeated challenges with ET-1 at 10.0 pmol/kg. Pretreatment with the cyclooxygenase inhibitors diclofenac had no inhibitory effect on the vasoconstriction induced by ET-1 at 10.0 and 50.0 pmol/kg. In 6 human volunteers the peak blood flow in the nasal septum decreased by -41.8 +/- 11.6% (p < 0.05) and AUC (area under curve) values decreased by -612.0 +/- 322.4% (p < 0.05) after challenge with 0.1 nmol ET-1, delivered in aerosol form into the nose. The effects of the endothelins on the blood flow in the upper airways of rabbit and man indicate that they have a functional role in the regulation of the mucosal vasculature of the upper airways.

[Effect of the phytogenic secretolytic drug Gelomyrtol forte on mucociliary clearance of the maxillary sinus]

BACKGROUND

To date, there has not been sufficient experimental evidence to demonstrate the pharmacological effect of secretolytic and mucolytic drugs.

METHODS

Scintigraphic studies to detect the mucociliary clearance in the maxillary sinus before and after application of the secretolytic drug Gelomyrtol forte were performed on four healthy persons and one patient after sinus surgery. The most important parameter was the mucociliary transport velocity of the "region of interest-maxillary sinus" and the increase of radioactivity accumulated in a tampon placed in the middle meatus of the nose. Measurements were done with a gamma-camera, 99 m Technetium-sulphurcolloid was used as the radiopharmacentical. A dose of 1 MBq in 0.2 ml NaCl-solution was injected into the maxillary sinus.

RESULTS

The results show a clear increase of mucociliary transport velocity in the maxillary sinus after intake of secretolytics in connection with an increase of radioactivity in the tampon.

DISCUSSION

The results can be explained by the secretolytic and secretomotoric effects of the investigated drug.

CONCLUSION

The study reveals that ethereal oils have secretolytic effects and also have a pharmacological effect on the mucociliary apparatus.

Effects of inflammatory mediators on ciliary function in vitro

Prostaglandins and histamine released during inflammatory and allergic reactions can affect the mucociliary system in different ways. By studying the effect of these mediators on ciliary beat frequency (CBF) with a photo-electrical technique in airway explants from different species, i.e. guinea-pig trachea, rabbit maxillary sinus, and human adenoid, the mechanisms underlying the effects of prostaglandin and histamine were further elucidated. Prostaglandin E1 (PGE1) produced a modest increase in CBF in preparations from guinea-pig trachea. The maximum response was 12.9 +/- 3.4% for the dose of 0.1 micrograms/ml, corresponding with 0.28 microM. Prostaglandin E1 produced a dose-dependent increase in explants from rabbit maxillary sinus, the maximum effect was 35.9 +/- 14.1% at a dose of 1.0 micrograms/ml. PGE1 produced a lesser increase in CBF in explants from human adenoids. A maximum increase of 4.1 +/- 1.6% was observed at a dose of 0.1 mg/ml. Histamine produced a moderate increase in CBF in explants from human adenoid at concentrations of 0.01-0.1 mM, corresponding with 1.84-18.4 micrograms/ml. In contrast, histamine did not significantly alter CBF in explants from the rabbit maxillary sinus or guinea-pig trachea. These results indicate that there are interspecies differences in the responsiveness to prostaglandins, and that PGE1 seems to have more powerful effects on CBF in the upper than in the lower airways.(ABSTRACT TRUNCATED AT 250 WORDS)

A new administration form of the nasal decongestant oxymetazoline: a study on the change of ostial patency in healthy individuals

A new administration form of the nasal decongestant oxymetazoline and the effect on patency of the maxillary ostium was investigated in five healthy volunteers. Registration and comparison of the equivalent diameter after administration of placebo spray and oxymetazoline spray, placebo solution and oxymetazoline solution were performed. It is our impression that administration of solution with the new spring-bellows container compared to spray oxymetazoline, is a more effective way of increasing the equivalent diameter of the maxillary ostium.

Effects of a new administration form of oxymetazoline on maxillary ostial patency in healthy individuals and patients with acute rhinitis

A new administration form of the nasal decongestant oxymetazoline and its effects on maxillary ostial patency were investigated in 5 healthy individuals and 20 patients with acute rhinitis. Registration and comparison of ostial patency after administration of placebo spray and oxymetazoline spray, placebo solution and oxymetazoline solution, were performed in healthy individuals. Patients with acute rhinitis were treated with either oxymetazoline solution or placebo solution, preceded and followed by registration of the equivalent maxillary ostial diameter. In both studies, solution was administered with a nasal bellows container. The results suggest that the administration of oxymetazoline solution with the nasal bellows container is a more effective way of increasing maxillary ostial patency in healthy individuals than oxymetazoline spray. In patients with acute rhinitis it also seems to be a way of increasing maxillary ostial patency.

Mucociliary function and endothelins 1, 2, and 3

Endothelins are recently discovered peptides that cause vasoconstriction and bronchoconstriction. The significance to the mucociliary system of endothelins (ET) 1, 2 and 3 in upper as well as lower airways has not yet been clarified. Effects of these active peptides were investigated, combining both in vitro and in vivo rabbit models of mucociliary activity from the maxillary sinus and the trachea. The studies were performed using computerized photometric microscopy. Immunohistologic staining procedures were used to determine the presence of endothelins in sinus and trachea epithelium. Significant effects on mucociliary activity were noted for ET-1, -2, and -3 in vitro as well as in vivo. All endothelins were noted to accelerate mucociliary activity of both sinus and tracheal mucosa. The effects of endothelins were greater in the sinus than in the trachea. In vitro studies using the calcium blocker nifedipine and the cyclooxygenase inhibitor diclofenac indicated that the mechanism of action involves an intermediary prostaglandin pathway but is independent of release of intracellular calcium. These results were confirmed using ET-1 in vivo. Immunohistochemical staining showed endothelin to be present in both maxillary and tracheal epithelium of the rabbit. We conclude that endothelins have significant mucociliary stimulatory effects and that the presence of endothelins in normal mucosa indicates a potentially important role in respiratory homeostasis as well as inflammatory conditions.

Effect of S-carboxymethylcysteine on ciliary activity in chronic sinusitis

This study was designed to investigate the possible pharmacological effect of S-carboxy-methylcysteine (S-CMC) on the ciliary activity, using an in vitro experimental system after removing mucus. Ciliary activity from healthy rabbit maxillary sinus and from healthy human nasal mucosa demonstrated no significant change in RPMI 1640 containing S-CMC. On the other hand, the effect of S-CMC on the reduced ciliary activity from patients with chronic sinusitis was quite varied among the cases examined. S-CMC demonstrated no stimulatory effect on the beating activity of cilia that have a baseline activity of less than 400 beats/min. However, S-CMC was able to enhance the beating activity of cilia that demonstrated a baseline activity of more than 400 beats/min. S-CMC at 0.5% induced a larger ciliostimulatory effect than 0.05% S-CMC. In conclusion, our study has clearly demonstrated that S-CMC could directly enhance ciliary activity of chronic sinusitis in the absence of significant organic change of ciliated cells.

The effect of noradrenaline on mucociliary activity in the rabbit maxillary sinus

The effect of noradrenaline (NA) on mucociliary activity in the rabbit maxillary sinus was investigated in vivo by injecting it at increasing dosages (10(-11) to 10(-4) mol/kg) into the maxillary artery, the mucociliary response being recorded photoelectrically. NA increased mucociliary activity at a dosage of 10(-5) mol/kg, the maximal increase being 16.1 +/- 2.6%. The NA-induced stimulation of mucociliary activity had a latency of 20 s, and the activity returned to base-line level within 3 min. Pretreatment with the alpha-antagonist phentolamine (0.2 and 1.0 mg/kg) or the cholinergic antagonist atropine (1 mg/kg) did not alter mucociliary response to NA. Blockade with the beta-antagonist propranolol did not significantly reduce the maximal response to NA, which was 16.1 +/- 2.6% before and 11.1 +/- 3.0% after pretreatment with propranolol (n = 7; p = 0.2). In contrast, pretreatment with the prostaglandin-synthesis inhibitor indomethacin reduced the response from 12.9 +/- 2.9% to 6.3 +/- 1.3% (n = 6; p < 0.05), suggesting that at high dosages NA stimulates mucociliary activity via the cyclo-oxygenase pathway.

Nose drops induce vasomotion in the microcirculation of the sinus mucosa of the rabbit

Periodic oscillations of blood in the microcirculation of the sinus mucosa in the rabbit were studied with laser-Doppler flowmetry after the application of nose drops (oxymetazoline, xylometazoline and phenylephrine) to the nasal mucosa. All of these drugs induced a dose-dependent decrease in the blood flow in the mucosa. Flowmotion was found in 9 of 21 experiments after an approximately 50% reduction in blood flow had been induced. The concentrations of the drugs which caused vasomotion corresponded to those normally administered as nose drops to man.

NK1 receptors mediate the increase in mucociliary activity produced by tachykinins

The mucociliary activity of the rabbit maxillary sinus is increased after exposure to airway irritants such as cigarette smoke and capsaicin. This effect is partly due to a cholinergic reflex but involves an atropine-resistant response probably mediated by the release of tachykinins such as substance P or neurokinin A from sensory nerve endings. The aim of the present investigation was to evaluate the type of tachykinin receptor which mediates this increase in mucociliary activity. The mucociliary activity of the rabbit maxillary sinus was studied photoelectrically in vivo. It was found that a selective NK1 receptor agonist, [Sar9,Met(O2)11]substance P, dose dependently stimulated mucociliary activity, the maximum increase being 43.74 +/- 6.07% at a dose of 1 nmol/kg. A selective NK2 receptor agonist, [Nle10]neurokinin A-(4-10), produced a much weaker response, the maximum increase being 15.23 +/- 3.86% at a dose of 10 nmol/kg, whereas an NK3 receptor agonist, [Pro7]neurokinin B, was without effect. When the effects of the selective agonists were compared with the responses elicited by naturally occurring tachykinins at a dose of 1 pmol/kg, the order of the magnitude of the responses was [Sar9,Met(O2)11]substance P > substance P > neurokinin A. At this dosage the NK2 and NK3 receptor agonists did not have a significant effect. Pretreatment with the endopeptidase inhibitor phosphoramidon did not influence the magnitude of the responses but increased their duration. It is concluded that the NK1 receptor is responsible for the increase in mucociliary activity elicited by tachykinins released from sensory afferents in the upper airways.

Effect of a topical vasoconstrictor on computed tomography of paranasal sinus disease

Apparent ethmoid inflammation which resolved with alternation of the nasal cycle or following application of topical vasoconstrictors has been observed with magnetic resonance imaging. A similar phenomenon might occur to a lesser degree with computed tomography (CT), leading to overdiagnosis of limited sinus disease. The degree to which ostiomeatal complex disease is reversible by topical vasoconstrictors was investigated. Ten patients with histories of chronic or recurrent sinusitis underwent coronal CT studies of the paranasal sinuses before and after the application of a topical vasoconstrictor. Mucosal volume or thickness measurements were obtained from the turbinates, infundibulum, ethmoidal cells, and antrum. Vasoconstrictor application markedly reduced turbinate size and appeared to reduce mucosal thickening in the ethmoidal infundibulum. Minimal mucosal changes identified in the paranasal sinuses by computed tomography were not reversed by vasoconstrictors and therefore are likely to be pathologic.

Neuropeptide Y 16-36 inhibits mucociliary activity but does not affect blood flow in the rabbit maxillary sinus in vivo

Recent investigations have shown neuropeptide Y (NPY) to be present in the rabbit maxillary sinus, and NPY is known to be released upon sympathetic nerve stimulation. To study, in vivo, the effect on mucociliary activity and blood flow, NPY 1-36 and some of its analogues were injected intra-arterially. The effects of the Y1/Y2 agonist NPY 1-36 was compared with the ones of the Y2 agonist NPY 16-36, the Y1-agonist [Leu31,Pro34]NPY and the Y1/Y2 agonist peptide YY. Mucociliary response was recorded photoelectrically and expressed as a percentage of the basal mucociliary activity immediately prior to challenge. The effect on blood flow was measured with laser Doppler flowmetry and expressed as a percentage of the mean blood flow during the 60 s preceding challenge. NPY 1-36 and NPY 16-36 both reduced mucociliary activity dose-dependently at equimolar dosages (0.024-1.2 nmol/kg). The greatest effect was seen after the highest dosage tested. NPY 1-36 reduced mucociliary activity by 14.6 +/- 1.8%, and NPY 16-36 by 13.2 +/- 1.4%. At the highest dosage tested the Y1 receptor agonist [Leu31,Pro34]NPY did not significantly reduce mucociliary activity, whereas PYY reduced mucociliary activity by 15.0 +/- 1.8%. Injections of NPY 16-36 had no effect on blood flow whereas NPY 1-36, [Leu31,Pro34]NPY and PYY all reduced blood flow dose-dependently. Maximal decrease was seen at the highest dosage tested and was 47.1 +/- 5.4%, 70.4 +/- 7.4% and 58.2 +/- 8.4%, respectively. These findings suggest the mucociliary effects to be mediated via Y2 receptors whereas blood flow is regulated via Y1 receptors.

[Experimental studies of wound healing in the paranasal sinuses. II. Spontaneous wound healing and drug effects in a standardized wound model]

A model of wound healing in the maxillary antrum of the rabbit was developed. The regeneration of standardized circular mucosal defects 4 mm in diameter was studied using conventional histology and serial sections as well as three-dimensional histomorphological analysis. Wound closure started by migration of epithelium; 24 h later mitoses were seen. 120 h after creation of the wound the granulation tissue covering the wound surface started to become hyperplastic, and bone apposition with formation of osteoid occurred. Systemic application of prednisolone i.m. (2 mg/kg per day) and topical administration of dexpanthenol-ointment (5%) resulted in an acceleration of the late epithelial wound closure together with a reduction of hyperplastic granulation tissue. Epidermal growth factor, applied locally, had no significant effect. The proposed animal model permits additional quantitative evaluation of postoperative treatment modalities.

The effect of neuropeptide Y on mucociliary activity in the rabbit maxillary sinus

The effect of neuropeptide Y (NPY) on mucociliary activity in the rabbit maxillary sinus was investigated in vivo by injecting NPY at increasing dosages into the maxillary artery, response being recorded photoelectrically. At dosages of 0.1-5.0 micrograms/kg, NPY reduced mucociliary activity dose-dependently, the maximum decrease being 14.6 +/- 1.8%, at a dosage of 5.0 micrograms/kg. The NPY-induced reduction of the mucociliary activity manifested brief latency, the peak effect occurring within 3 min followed by a slow return to the baseline value 4-9 min after injection. The response of mucociliary activity to NPY remained unaffected by pretreatment with the alpha-adrenergic antagonists yohimbine (alpha 2) at 100.0 micrograms/kg and phentolamine (alpha 1 + alpha 2) at 0.2-1.0 mg/kg, indicating that the effect of NPY is not mediated via alpha-receptors. Pretreatment with the calcium antagonist nifedipine at 100.0 micrograms/kg inhibited the effect of NPY, suggesting that the NPY-induced decrease may be calcium dependent.

Otolaryngic manifestations of myiasis

Although rare in North America and Europe, myiasis is seen occasionally in tropical and undeveloped countries. This disorder results from the penetration of a fly larva into a part of the human body, and it causes various symptoms in the host. The exposed areas of the skin are the ones predominantly affected and the eyes, ears, nose, and paranasal sinuses are less commonly affected. We review our experience with 12 patients with myiasis of the ears, nose, and paranasal sinuses.