McCaffrey, Thomas V.

It has been suggested that leukotrienes C4 (LTC4) and D4 (LTD4) released from upper respiratory mucosa influence mucociliary transport during allergic reactions. We studied the in vitro effects of leukotrienes C4 and D4 on the ciliary beat frequency (CBF) of human adenoid explants over a 5‐hour period. Tissue explants were cultured at 35° C in Minimum Essential Medium Eagle (MEM). The CBF was measured using phase contrast microscopy and microphotometry. Measurements of CBF were recorded in medium alone and in medium containing LTC4 or LTD4 at concentrations of 10−8 and 10−6 M. LTC4 and LTD4 increased CBF at concentrations of 10−8 and 10−6 M with increases of 20.51% ± 2.69% and 29.84% ± 4.06%, respectively. To determine the specificity of the LTC4 and LTD4 effects, the ciliated epithelium was treated with the specific leukotriene receptor antagonist LY‐171,883 before administration of LTC4 and LTD4. LY‐171,883 (10−6 M) significantly inhibited the ciliostimulatory effects of both leukotrienes. Our findings indicate that LTC4 and LTD4 increase CBF in vitro by activation of the LTD4 receptor.

Abnormal mucociliary clearance in the paranasal sinuses is a significant factor in the pathogenesis of sinusitis. This study examined effects of chronic sinusitis on ciliary beat frequency (CBF), mucociliary transport (MCT) velocity, mucociliary transport patterns, and histology of sinus mucosa in rabbits. Two groups of rabbits were studied: uninfected (n = 9) and infected (n = 18). Maxillary sinus ostia in all animals were occluded, and sinuses in the infected group were inoculated with 10 8 cfu of Streptococcus pneumoniae. Chronic sinusitis developed over 6 weeks and was confirmed by histopathology and culture. Evaluation of the MCT mechanism included 1) measurement of CBF using a photometric technique, 2) direct measurement of MCT velocity, and 3) analysis of MCT patterns with inert India ink. In seven of nine (77.8%) uninfected animals, the mean CBF was 11.5 Hz (±.39 Hz) initially and 11.3 Hz (±.32 Hz) 6 weeks after occlusion (P = 0.69). MCT velocity measured 20.6 mm/min (±1.40 mm/min) initially and 16.85 mm/min (±1.96 mm/min) 6 weeks after occlusion (P = 0.16). In the infected group, there were statistically significant decreases in CBF (P < 0.05) and measured MCT velocity (P < 0.05). Examination of MCT in infected animals showed patterns of misdirected flow, pooling, and stagnation. Histopathologic changes included significant losses of ciliated epithelium and mucosal abnormalities consistent with chronic sinusitis. Chronic sinusitis secondary to long-standing bacterial infection leads to alterations in CBF, MCT velocity, and MCT patterns in the paranasal sinuses of rabbits.

The purpose of this study was to compare the effects on human nasal cilia of various freezing and thawing methods in order to determine a reliable method of cryopreservation. Ten samples each were preserved by a slow freezing and a fast freezing method. All samples were stored in liquid nitrogen (–196°C) for 1 week. The frozen samples were thawed by one of two methods: 1) rapid thawing—37°C water bath for 3–4 minutes; and 2) slow thawing—room temperature for 15 minutes. Prefreeze and postthaw ciliary beat frequency (CBF) was measured. The slow freezing and fast thawing method (SFFT) resulted in the best viability. An additional 10 samples preserved using the SFFT method stored at –70°C to –90°C did not retain ciliary function. Thirty ciliated samples preserved by the SFFT method were examined after freezing in liquid nitrogen (–196°C) for 1 week, 2 weeks, and 1 month. There was no significant decrease in CBF after cryopreservation at –196°C for 1 week or 2 weeks (P> 0.05). As the storage time increased to 1 month, postthaw CBF decreased 7.25 ± 0.87% when compared to the prefreeze CBF (P < 0.05). We conclude that human nasal cilia preserved by SFFT at –196°C retain activity for up to 1 month.

Normal mucociliary clearance in the paranasal sinuses must be restored to reverse the effects of chronic sinusitis. This study examined effects of middle meatal antrostomy (MMA) on ciliary beat frequency (CBF), mucociliary transport (MCT) velocity, MCT patterns, and histology of sinus mucosa in rabbits with chronic sinusitis to determine whether objective measures of mucociliary function and histology could be reversed. Two groups of rabbits were compared: uninfected (Group A controls, n = 9) and infected (Group B, n = 11). Maxillary sinus ostia were occluded; 10 8 cfu of Streptococcus pneumoniae were inoculated into sinuses of rabbits in group B, and chronic sinusitis developed. This was confirmed by histopathology and culture 6 weeks after infection. Middle meatal antrostomies were performed in the infected group, and sinuses were studied 6 weeks later. Control animals (Group A) had mean CBF = 11.5 Hz (±.39 Hz). Animals with chronic sinusitis (Group B) had mean CBF = 8.6 Hz (±.24 Hz). This was statistically different from control (P < 0.05). Six weeks following MMA, group B had mean CBF = 12.9 Hz (±.75 Hz). This was not different from control. There were changes in MCT velocity that correlated with the CBF (r = 0.72). Examination of MCT patterns after MMA demonstrated minimal pooling and stagnation; however, small areas of misdirected flow persisted. After MMA, there were decreased numbers of inflammatory and goblet cells and increased numbers of ciliated epithelial cells. This study demonstrated that mucociliary clearance and histological changes seen in rabbits with chronic sinusitis are reversed by MMA.

Prostaglandins are ubiquitous within tissues and participate in several local regulatory functions. Previous reports have presented conflicting evidence on their role in ciliary activity in the upper airway. We studied the in vitro effects of prostaglandin E 2 (PGE 2 ) and a prostaglandin I 2 analog (Iloprost) on the ciliary beat frequency (CBF) of human adenoid explants and rabbit sinus mucosa. Tissue explants were maintained in culture at 35°C. PGE 2 or Iloprost was added to the culture media at concentrations of 10 –6 , to 10 –12 M. CBF was determined using phase contrast microscopy and microphotometry. PGE 2 increased CBF with a maximum increase of 54.6% in rabbit mucosa (P < 0.01) and 20.0% in human adenoid (P < 0.009). Iloprost increased CBF with a maximum increase of 35.2% in rabbit mucosa (P < 0.02) and 16.4% in human adenoid (P < 0.03). Induced production of endogenous prostaglandins was determined by treating specimens with a cyclooxygenase inhibitor (diclofenac) prior to addition of PGE 2 or Iloprost. Diclofenac had no effect on the ciliostimulatory effects of PGE 2 (P > 0.36), however it significantly decreased the ciliostimulatory effect of Iloprost (P < 0.037). Both PGE 2 and Iloprost stimulate ciliary motility, yet the action of PGE 2 is direct, whereas Iloprost stimulates cilia by release of endogenous prostaglandins in both the human and rabbit.

Prostaglandin E2 (PGE2) is a known modulator in upper airway ciliary activity and may be involved in the transduction of the muscarinic acetylcholine receptor signal. We studied the in vitro effects of muscarinic ciliostimulation on ciliary beat frequency (CBF) and PGE2 in human adenoid explants to determine whether PGE2 production is an essential step in the signal transduction mechanism. Methacholine applied to adenoid explants significantly increased ciliary beat frequency. This effect was blocked by the application of diclofenac, a cyclooxygenase inhibitor. Using radioimmunoassay, PGE2 production was measured during ciliostimulation with methacholine. Methacholine produced a significant increase in production in PGE2 during ciliostimulation. The roles of phospholipase C and phospholipase A2 in prostaglandin production were investigated by inhibiting these enzymes. D609, a phospholipase C inhibitor, significantly inhibited ciliary beat frequency increase and PGE2 production during methacholine stimulation. However, PACOCF3, a phospholipase A2 inhibitor, did not block ciliary beat frequency increase or PGE2 production in response to methacholine. These data show that phospholipase C is required for PGE2 production and ciliostimulation.

The transseptal/transsphenoidal approach to the pituitary gland has been the most commonly used approach for resection of pituitary adenomas for the last 50 years. This procedure has a low morbidity and provides direct midline access to the sella and pituitary gland. Recent advancements in endoscopic surgery, however, suggest that a lower morbidity approach to the sella would be possible via transnasal endoscopic route. Prior reports have confirmed effectiveness of this approach to the pituitary gland and we report here an early series of endoscopic transnasal pituitary surgery from our institution. We report seven cases of transnasal endoscopic pituitary surgery. Our technique consists of endoscopic exposure of the sphenoid ostium unilaterally, excision of the posterior septum anterior to the rostrum of the sphenoid sinus with resection of the sphenoid rostrum for bilateral exposure of the sphenoid sinus. A specially designed nasal speculum is positioned to displace the posterior septum and lateralize the middle turbinates, permitting direct midline exposure of the sphenoid sinus and sella. We have progressively modified the technique over the seven cases that we present and will discuss our specific instrumentation, indications, and technique for this procedure. We have encountered one cerebrospinal fluid leak in this series. Patient satisfaction has been high and hospitalization is less than with the conventional transseptal approach, averaging 1 day. Our impression is that the transnasal endoscopic approach to pituitary adenomas is a safe technique with reduced morbidity permitting shortened hospital stay.

The increasing use of endonasal techniques and a new 3-dimensional CT-guided imaging system have allowed us to develop a combined, minimally invasive endonasal approach to the pituitary gland. Thus far, more than 30 patients have undergone an endonasal transsphenoidal approach to the sella using a combined endoscopic approach, with additional selective use of the Instatrak CT-guided imaging system for realtime imaging. Our current technique involves obtaining a preoperative CT using a plastic head frame with registration markers. By using this head frame intraoperatively, real-time localization with CT images in axial, coronal, and sagittal planes can be performed. Using endoscopic techniques and a Papavero-Caspar speculum, the sella is exposed. A combined approach using endoscopes, the operating microscope, and real-time localization is undertaken to expose and resect tumors. We have encountered minimal associated complications in our series, and this method has been progressively modified to improve exposure and safety. Because we are able to visualize the sella without a sublabial incision or septal resection, we have nearly eliminated the need for nasal packing, reduced the average hospital stay to 2.5 days, and improved patient satisfaction.

Ciliary ultrastructural abnormalities secondary to chronic sinusitis may cause abnormal mucociliary transport clearance. We examined the relationship between anatomic abnormalities of ciliary ultrastructure secondary to chronic sinusitis and ciliary beat frequency (CBF) before and after middle meatal antrostomy (MMA) in rabbits. Ultrastructural abnormalities of cilia included absence of axoneme membrane, blebs of the axoneme membrane, compound cilia, and ciliary orientation. Two groups of rabbits were studied: Uninfected (group A control, n = 3) and infected (group B, n = 10); 10 8 CFU S. pneumoniae were used to infect the animals in group B after sinus ostial occlusion and chronic sinusitis developed. After 6 weeks with infection, 6 of 10 group B animals underwent MMA and were restudied 6 weeks later. Uninfected animals had mean CBF = 11.75 Hz. Animals with chronic sinusitis had mean CBF = 8.5 Hz (p < 0.05). Six weeks after MMA, mean CBF = 11.82 Hz. This was not different from control. There were significant changes in ciliary ultrastructure when uninfected and infected rabbits were compared. These changes were reversed with MMA. Changes in ciliary ultrastructure correlated significantly with changes in CBF for all animals. Abnormalities in ciliary ultrastructure may account for the abnormal mucociliary transport clearance seen in chronic sinusitis in rabbits.