Mucociliary activities in fetal rabbits

There have been many morphological investigations on the generation of respiratory epithelium. However, the mucociliary activity of fetal respiratory epithelium has never yet been discussed. In the present work, ciliary activity and mucociliary function in the nose and the trachea of fetal rabbits were studied and, moreover, their respiratory epithelial cells were observed by scanning and transmission electron microscopy. Ciliary activity as noted on the 26th day of fetal life (day 26) for the first time in both of the nasal and the tracheal region and this activity was already equivalent to that in adult rabbits. Mucociliary transport function in either region was first noted on day 27. A quantitative as well as a qualitative immaturity of the respiratory epithelium was recognized on the last day of observation (day 29). The quantitative immaturity is characterized by 1) the ratio of ciliated to non-ciliated cells being lower than in the adult epithelium, 2) each ciliated cell possessing about three-fifths as many cilia as those of a full-grown cell, and 3) some cilia being smaller than full-grown ones and the qualitative immaturity by the directional disorder of the basal foot. No differences were observed between a cilium on day 25 or earlier, another on day 26 or later, and a full-grown cilium. It is suggested that cilia of the respiratory epithelium are morphologically prepared for motion and are activated on day 26 by changes in their surroundings, and that the poorer mucociliary transport in fetuses despite an almost normal ciliary beating is due in fairly large part to their qualitative immaturity (directional disorder of the basal foot).     

The effects of retinoic acid on ciliary function of regenerated sinus mucosa

BACKGROUND: Retinoic acid (RA) has been shown to enhance ciliary ultrastructure in regenerated sinus mucosa compared with controls. However, the functional status of the regenerated cilia has not been studied. Our objective was to evaluate the ciliary beat frequency (CBF) of regenerated sinus mucosa treated with topical RA in a rabbit model. METHODS: Twelve rabbits underwent bilateral surgical stripping of the maxillary sinuses, followed by treatment with RA gel in the right side and an inert gel control in the left side. The rabbits were then killed at either 2 or 4 weeks, and CBF analysis of the regenerated mucosa was performed. Three unoperated rabbits were used to establish normative CBF data. RESULTS: Functional cilia were recovered from 11/12 RA-treated sinuses and 12/12 gel control sinuses. At 2 weeks postoperatively, the RA-treated sinuses showed an average CBF of 19.78 Hz, which was statistically comparable with the normal unoperated controls (p < 0.26). The inert gel-treated mucosa showed a CBF of 29.24 Hz, which was significantly elevated compared with normals (p < 0.05). At 4 weeks, ciliary activity persisted, but both RA-treated sinuses and gel controls showed elevated CBF compared with normals (p < 0.03). CONCLUSION: Topical RA placed in a demucosalized maxillary sinus yields functional cilia. RA appears to have a normalizing effect on CBF early in the mucosal wound healing process compared with control. This effect appears to be mitigated in later stages of wound healing. RA may be beneficial in enhancing morphological and functional aspects of regenerating cilia.     

Mucociliary activity and histopathology of sinus mucosa in experimental maxillary sinusitis: A comparison of systemic administration of antibiotic and antibiotic delivery by polylactic acid polymer

To evaluate the efficacy of antibiotic delivered by polyactic acid (PLA) polymer in sinusitis, we induced maxillary sinusitis in 32 New Zealand white rabbits by occluding the sinus ostium and inoculating the sinus cavity with Streptococcus pneumoniae. The rabbits were divided into three groups consisting of group 1 (control group, 8 rabbits), which was treated only by reopening the ostium; group 2, which was treated by both reopening the ostium and injecting ampicillin intramuscularly (40 mg/kg/day in three divided doses, 12 rabbits); and group 3 (12 rabbits) in which a piece of PLA-polymer ampicillin (0.326 mg) sheet (1.5 × 1.5 cm) was placed within the sinus after re-establishing ostial patency. The light microscopic findings such as epithelial ulceration, loss of cilia, infiltration of inflammatory cells, and edema were less pronounced in group 2 and minimal in group 3. The electron microscopic findings such as swelling of mitochondria and endoplasmic reticulum and protruded cytoplasm were severest in the control group, followed by groups 2 and 3. The mucociliary transport speed measured at the medial wall of the maxillary sinus was highest in group 3. The results of this study suggest that treatment with PLA-polymer ampicillin may have a better efficacy in maxillary sinusitis than that with systemic administration of ampicillin.     

Experimental acute sinusitis in rabbits. Energy metabolism in sinus mucosa and secretion

In previous studies, sinus secretions have been analysed concerning pO2, pCO2 and pH. In this study the energy metabolism in the maxillary sinus mucosa and secretion was studied in 33 New Zealand White rabbits. In freeze-dried samples, glucose and lactate were analysed by enzymatic assays and ATP by HPLC. In the purulent sinusitis, lactate concentration in the mucosa was 5.67 mmol X kg-1 w.w. and significantly higher than in the control sinus. Also in the non-purulent sinusitis, lactate was increased in the mucosa. The lactate concentrations in the secretion were 9.8 and 8.4 mmol X kg-1 w.w. in purulent and non-purulent secretions respectively and are probably the result of a diffusion from the mucosal cells and of leukocyte metabolism. A reduced ATP content, with increases in ADP and AMP, in the sinus mucosa of the purulent sinusitis suggests a relative energy depletion which could result in impaired epithelial function.     

Evaluation of ultrastructural changes in paranasal sinus mucosa after functional endoscopic sinus surgery in patients with chronic rhinosinusitis

The purpose of this study was to compare the preoperative and postoperative ultrastructural changes of paranasal sinus mucosa in patients treated with functional endoscopic sinus surgery for chronic rhinosinusitis. Twelve patients undergoing functional endoscopic sinus surgery for the treatment of chronic rhinosinusitis were involved. The ethmoid sinus mucosa was sampled during the operation and approximately 6 months after the operation. The ciliated epithelium of sinus mucosa was evaluated with transmission electron microscopy. The samples were taken at the Otolaryngology Department of Istanbul University School of Medicine. Electron microscopic study was performed at the Histology and Embryology Department of the same University. Preoperatively, ciliated epithelial cells of the sinus mucosa of the patients showed degenerated ultrastructure with decreased number of cilia, cytoplasmic protrusions, cisternal dilatations of endoplasmic reticulum, and mitochondrial swellings. Remnants of degenerated cells and cellular separations at cell junctions were evident in the diseased epithelium. Goblet cells were frequent along the epithelial lining. Postoperatively, normal architecture and ultrastructure of the ciliated epithelium was restored. These observations showed that unlike other surgical operations, paranasal sinus mucosa can regenerate and the ciliated epithelium can return to normal after functional endoscopic sinus surgergy.     

The vascular arrangement of the sinus mucosa. A study in rabbits

Seventy-seven New Zealand White rabbits, with an average weight of 3 kg, were used in studies on the paranasal sinus. Replica moulds of the sinus revealed a sinus cavity composed of three compartments with a total volume of 2-3 ml. The sinus cavity was connected with the nasal cavity through an ostium. By intravascular injection of silicone rubber for dissection and of methacrylate for production of corrosion casts, the vascular bed and the vessels passing to and from the sinus cavity were studied. The main arterial supply and venous drainage takes place through the ostium, which is surrounded by a dense venous plexus. Compared with the nasal mucosa, the number of vessels per volume unit is about the same in the sinus mucosa. Many vessels perforating through the osseous walls, both arteries and veins, were found, however, indicating that the blood supply is not derived exclusively from vessels coming through the ostium.     

家兔急性鼻窦炎上颌窦黏膜病理改变

目的 观察家兔实验性鼻源性急性鼻窦炎上颌窦黏膜超微结构及黏液纤毛传输功能的改变.方法 健康成年雄性新西兰白兔15只,随机分为实验组(10只)和空白对照组(5只).将3 mm×5 mm×25 mm大小Merocel(R)高分子膨胀海绵置入实验组兔右侧鼻腔,并向高分子膨胀海绵中注射植入1 mlⅢ型肺炎链球菌悬液.2周后,用印度墨汁法测定上颌窦黏液纤毛传输速度.然后处死动物,取右上颌窦黏膜通过透射电镜观察其超微结构改变.结果 实验组家兔上颌窦黏液纤毛传输速度明显低于空白对照组,有极显著统计学差异(P＜0.01).实验组上颌窦黏膜在透射电镜下观察到纤毛变性、脱落,排列紊乱,可见复合纤毛、微管动力臂缺陷、胞质突起、内质网扩张、线粒体肿胀、胞浆水肿及黏膜下层淋巴细胞浸润等超微的结构改变.结论 急性鼻窦炎上颌窦黏膜超微结构明显改变,黏液纤毛传输速度减慢,结构改变导致功能下降.     

Assessing the maxillary sinus mucosa of rabbits in the presence of biodegradable implants

In an attempt to improve the quality of life of patients with vitreous humor disease, ophthalmologists began offering steroid-eluting biodegradable implants to their patients. These implants can be used as an alternative treatment for CRS and this is why this experimental study was carried out on rabbit maxillary sinuses.ObjectiveThis study aims to assess the histology of the mucosa of the maxillary sinuses of rabbits after the placement of a prednisolone-eluting biodegradable implant.MethodEighteen rabbits were randomly divided into two groups: group 1 - subjects had drug-eluting implants placed on their left maxillary sinuses; group 2 - subjects had non-drug-eluting implants placed on their left maxillary sinuses. The right maxillary sinuses served as the controls. After seven, 14, and 28 days three rabbits in each group were randomly picked to have their tissue inflammatory response assessed.ResultsLevels of mucosal inflammation were not significantly different between the groups with and without drug-eluting implants and the control group, or when the groups with drug-eluting implants and non-drug-eluting implants were compared.ConclusionSigns of toxicity or mucosal inflammation were not observed in the maxillary sinuses of rabbits given prednisolone-eluting implants or non-drug-eluting implants.     

Mucociliary activity and the diving reflex

It has previously been shown that mucociliary activity in the rabbit maxillary sinus is immediately increased after short-term exposure to such airway irritants as cigarette smoke and ammonia vapor. This increase is mediated through the stimulation of capsaicin-sensitive nerve endings. Besides producing the mucociliary effect, these irritants inhibit breathing, a response characteristic of the diving reflex in mammals. Whether an increase in mucociliary activity is part of the diving reflex was investigated by injecting 0.5 mL water into the nasopharynges of anesthetized rabbits. Mucociliary and respiratory responses were compared with the effects of mechanical stimulation (ie, rotating an intranasal catheter until sneezing occurred). Water challenge produced an increase in mucociliary activity of 21.6% +/- 2.4%, a response that began approximately 10 seconds after injection. Mucociliary acceleration was completely blocked by atropine, indicating a cholinergic mechanism, but was unaffected by pretreatment with capsaicin. The respiration rate was inhibited by about 45% after challenge with water. Pretreatment with atropine and capsaicin had no effect on this reduced respiratory rate. Mechanical stimulation of the nasal mucosa accelerated mucociliary activity. This response appeared approximately 4 seconds after stimulation was begun, and occurred simultaneously with the onset of sneezing. The peak increase was 22.0% +/- 2.1%. Sneezing was followed by an increase in the respiration rate of about 40%. Pretreatment with atropine or capsaicin had no effect on respiratory responses, but did inhibit mucociliary acceleration, suggesting that the response is mediated through cholinergic effector neurons after activation of capsaicin-sensitive nerve endings.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of endoscopic sinus surgery on mucociliary activity and healing of maxillary sinus mucosa

The aim of this study was to determine histologic findings in the maxilaarysinus mucosa by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and ciliary activity within the nasal cavity by measuring the speed of mucociliary transport and after endoscopic sinus surgery (ESS). Thirty patients were enrolled. Thirty-eight antral mucosae of 24 24 patients were investigated according to ultrastructural changes and 6 patients were accepted as controls. At the 12th week, 12 antral nasal mucosae specimens of 8 patients were evaluated. All the specimens were taken from the medial rear wall of the antrum. The specimens were observed under a SEM and TEM. The mucociliary activity was measured within the nasal cavity by a saccharin test in all patients before the operation and after 12 weeks. Twenty people served as controls. In the specimens of the preoperative mucosa, the ciliated epithelium was heavily deciliated, interdigitation of the cell was loosened. In the samples taken 12 weeks after the operation, the ciliated cells were irregularly seen, the number of goblet cells was about the same as in the preoperative group and in the control, the number of the gland openings was higher than in the preoperative group and in the control. Also the interdigitation of the cells was enhanced. The histological and morphological features of the mucosa had improved. The period of the preoperative saccharin test was 12.15 minutes, whereas the period of the postoperative test was 9.08 minutes. The improvement was significant but both results were also significantly longer compared to the controls. These observations suggest that the histological, morphological and mucocilliary activity of the mucosa have not yet improved completely, it takes more than 12 weeks to recover, and the patients should be closely monitored in the postoperative months.     

鼻窦清合剂对兔鼻窦炎上颌窦黏膜形态影响的电镜观察

目的 观察鼻窦清合剂对兔鼻窦炎上颌窦黏膜炎症的影响。方法 行窦口不完全堵塞加用金黄色葡萄球菌建立急慢性鼻窦炎动物模型后,予以鼻窦清合剂高、低剂量灌胃治疗,并设立空白组、模型组、鼻渊舒（鼻渊舒口服液灌胃） 组作为对照;急性期用药1周,慢性期用药2周后,分别通过透射电子显微镜观察 ,比较各组兔上颌窦黏膜形态结构的变化。结果 鼻窦清合剂低剂量组黏膜形态最接近正常组,且急性各组优于慢性各组。结论 鼻窦清合剂可改善兔上颌窦炎症。     

Mucociliary transport and histologic characteristics of the mucosa of deviated nasal septum

OBJECTIVE: To investigate differences in mucociliary clearance, histologic characteristics, and surface structure of the bilateral nasal septal mucosa in patients with nasal septal deviation. DESIGN: Mucociliary transport was measured by saccharin clearance time in both nasal cavities of 20 patients with nasal septal deviation. Their septal mucosae were taken during septoplasty, and the ciliary population was studied by scanning electron microscopy. Histologic differences in the lamina propria of septal mucosae were compared under a light microscope. RESULTS: The concave side showed longer saccharin clearance time than the convex side and revealed much more severe loss of cilia. Inflammatory cells more heavily infiltrated the concave side, and seromucinous glands were less densely distributed. CONCLUSION: Concave-side septal mucosae have impaired mucociliary transport, presumably due to ciliary loss, increased inflammation, and decreased density of the glandular acini.     

Effects of staphylococcal enterotoxin on ciliary activity and histology of the sinus mucosa

CONCLUSION: The results of our study suggest that Staphylococcus aureus enterotoxin A (SEA) may play an important role in the pathogenesis of rhinosinusitis by ciliostatic effects at high concentrations, and by a different mechanism at low concentrations. OBJECTIVES: To investigate the in vitro effects of SEA on ciliary activity and its in vivo effects on histology of the sinus mucosa. MATERIALS AND METHODS: The in vitro effects of SEA on ciliary activity at different concentrations and exposure time were investigated using maxillary sinus mucosa harvested from experimental rabbits. After in vivo instillation of different concentrations (high and low dose) of SEA into the maxillary sinus, ciliary beat frequency (CBF) and histologic findings of the maxillary sinus mucosa were examined. RESULTS: After exposure to low doses of SEA (0.03 and 0.3 ng/ml), CBF did not decrease, but after exposure to high doses of SEA (1.5, 3, and 30 ng/ml), CBF decreased significantly as a function of time. At 24 h after instillation of high-dose SEA (30 ng/ml) into the sinus, CBF decreased significantly and rhinosinusitis was induced after 7 days. Although no alteration was observed in the CBF of the sinus mucosa after instillation of low-dose SEA (0.3 ng/ml), histological findings of rhinosinusitis including subepithelial edema and inflammatory cell infiltration were observed.     

Effects of staphylococcal enterotoxin on ciliary activity and histology of the sinus mucosa

Conclusion. The results of our study suggest that Staphylococcus aureus enterotoxin A (SEA) may play an important role in the pathogenesis of rhinosinusitis by ciliostatic effects at high concentrations, and by a different mechanism at low concentrations. Objectives. To investigate the in vitro effects of SEA on ciliary activity and its in vivo effects on histology of the sinus mucosa. Materials and methods. The in vitro effects of SEA on ciliary activity at different concentrations and exposure time were investigated using maxillary sinus mucosa harvested from experimental rabbits. After in vivo instillation of different concentrations (high and low dose) of SEA into the maxillary sinus, ciliary beat frequency (CBF) and histologic findings of the maxillary sinus mucosa were examined. Results. After exposure to low doses of SEA (0.03 and 0.3 ng/ml), CBF did not decrease, but after exposure to high doses of SEA (1.5, 3, and 30 ng/ml), CBF decreased significantly as a function of time. At 24 h after instillation of high-dose SEA (30 ng/ml) into the sinus, CBF decreased significantly and rhinosinusitis was induced after 7 days. Although no alteration was observed in the CBF of the sinus mucosa after instillation of low-dose SEA (0.3 ng/ml), histological findings of rhinosinusitis including subepithelial edema and inflammatory cell infiltration were observed.     

Mucociliary clearance abnormalities in the hiv-infected patient: A precursor to acute sinusitis

An increasing number of patients with human immunodeficiency virus (HIV) suffer from acute infectious sinusitis, and many suffer recurrent episodes at a higher rate than their non-HIV counterparts. This study investigates a mechanism underlying the increased incidence of sinusitis, that of prolonged mucociliary transport time (MTT). Nasal mucociliary clearance was examined in 30 HIV-infected patients and 30 matched, non-HIV controls using a nasal saccharin transport test. MTTs for the study group and the controls were 11.9 ± 5.9 minutes and 7.4 ± 3.7 minutes, respectively. This difference attained statistical significance (P < .05). Study group patients with a history of sinusitis had a mean MTT of 13.7 ± 6.8 minutes. Those with complaints of “new onset” nasal obstruction since HIV conversion had a mean MTT of 13.5±6.8 minutes. Statistical significance (P < .05) was found comparing these times to controls, as well as to study patients without these symptoms. These data support an inherent delay of mucociliary clearance in HIV-infected patients which is chronic, possibly irreversible, and, in association with nasal obstruction, represents a major mechanism of both the high acute and recurrent sinusitis rate in this population. The cause of the mucociliary delay is still unclear and needs to be further investigated.     

Mucociliary activity of free transplanted respiratory epithelium]

The function of free grafted respiratory epithelium was investigated in inbred rats. In nine of ten animals it could be shown that the respiratory epithelium not only regenerated as an epithelial surface lining but also regained mucociliary activity. The grafted epithelium was able to secrete mucus, which was equal in protein fragmentation to the secretion of normal nasal mucosa. The grafted respiratory epithelium showed normal ciliary function which could be demonstrated by recording the ciliary beat pattern present and by subsequent histological examination. Morphologically, a regular structure of ciliae (9 + 2) was found on the upper pole of the regenerated ciliated cells.     

Differences in Mucociliary activity of volunteers undergoing Ramadan versus Nineveh fasting

This study, aimed to evaluate the difference in mucociliary clearance among volunteers who underwent Ramadan versus Nineveh fasting regimens as well as the difference between the fasting period and 4 weeks following the fasting period in both groups. In this study, two different fasting groups were established: Ramadan (fasting for an average of 15 h for 29 consecutive days, n = 40) and Nineveh (60 h of nonstop fasting, n = 26). Subjects in each group underwent saccharin testing twice: at the end of the fasting period prior to resumption of eating and at 4 weeks after the end of Ramadan or Nineveh fasting. Statistical analysis was performed using the Mann–Whitney U-test, Wilcoxon, Chi-square, and paired t test. A p value less than 0.05 was considered statistically significant. Forty subjects who underwent Ramadan fasting and 26 subjects who underwent Nineveh fasting were included in this study. Of the 66 study participants, 34 (51.5 %) were men and 32 (48.5 %) were women. Their median age was 31 years (range 17–70 years) for Nineveh fasting subjects and 40 years (range 17–70 years) for Ramadan fasting subjects. Chi-square tests revealed no significant difference between the Ramadan and Nineveh fasting groups in gender (p = 0.418), and the Mann-Whitney U-test showed no difference in age. A statistically significant difference was found in the mucociliary clearance time between the Nineveh fasting and non-fasting periods (p = 0.013). Using Wilcoxon signed-rank tests, we found no significant difference in the mucociliary clearance time between the Ramadan fasting and control (4 weeks after the fasting period) periods (p = 0.121). The percentage difference between the fasting and control periods was similar between groups and was not statistically significant for the Ramadan and Nineveh fasting groups (p = 0.086). The results of the present study indicated that long-term fasting with hypohydration contributed to the deterioration of nasal mucociliary clearance. Our data indicate that optimal hydration, sleep patterns, and fasting times contribute to proper mucociliary clearance.     

Melanoma of the nasal and paranasal sinus mucosa

Melanoma involving the nasal and paranasal sinus mucosa is a rare disease that is difficult to treat and generally has a poor prognosis. Data on 17 patients treated at the UCLA Medical Center during the period 1970 to 1985 were reviewed in a retrospective manner. The five-year disease-free survival was 25% (3/12). Surgery, with or without radiation therapy, is the mode of treatment to control disease in most patients. Treatment failures, which include both local recurrence and distant metastases, may occur many years after initial therapy. We found a correlation between the thickness of tumor and the clinical outcome.