Mucosubstance histochemistry and pathogenesis of acquired cholesteatoma

Mucosubstance histochemical study of 33 cholesteatoma tissues was performed to clarify the distribution and character of mucin in the perimatrix. Mean density of glandular cysts was 0.18 per mm². Mean frequency of ruptured cysts was 0.16 per cyst. Glandular cysts as well as hallow spaces in the perimatrix were filled with sulfomucin and sialomucin. Fragments of mucin were found in some macrophages and multinucleated giant cells. Since phagocytosis is host defenses attempt, the process indicates that mucin in the perimatrix is a cause of inflammation. Sialomucin infiltrated in the subepidermis where the epidermis formed papillary proliferation without an apparent sign of inflammation. Six glandular cysts were found in the matrix and the debris. They may have been eliminated from the perimatrix as a sequel to cholesteatoma growth. These findings suggest that embedded mucosa in the perimatrix may play a crucial role in pathogenesis of acquired cholesteatoma.     

The effect of parental smoking on outcome after treatment for glue ear in children

A sample of 201 children aged between 2 and 9 years with bilateral chronic otitis media with effusion (OME) were treated prospectively and at random by adenoidectomy, adenotonsillectomy, or with neither procedure. In all cases only a unilateral grommet was inserted and the contralateral unoperated ear was examined one year post-operatively for persistence or resolution of the effusion. A self-administered questionnaire was completed by the parents concerning their smoking habits. The resolution of effusion following surgery was assessed in relation to smoking by the mother and father separately and in combination. Clearance of glue was statistically less frequent where the child's mother or where both parents smoked. This was related to the number of cigarettes smoked by the mother or both parents. The adverse effect was demonstrable whether or not adenoidectomy or adenotonsillectomy had been performed for treatment. The findings lend further support to professional and governmental opinions of a deleterious effect of passive smoke exposure on children and in this case parental smoking has been shown to have an adverse effect on the outcome of OME following surgical treatment.     

Test-retest variability of eustachian tube responses in children with persistent middle ear effusion

Summary In our previous studies on eustachian tube function in children with middle ear effusion, we found that many ears were evacuated by the act of sniffing. When subjects were tested repeatedly, however, responses to sniffing were very variable. In order to study the spontaneous variability, a total of 51 subjects (81 ears) were retested. The results of the retest were very similar to those of the first test when all the ears were considered as a group. However, in individual ears pronounced variability was seen. In the sniff test, responses changed qualitatively in 30% of the ears, and in 27% of the ears there was a change in the ability to equalize pressure by swallowing. Thus, the results of the group were highly reproducible, while at the same time individual results were highly variable with time.     

The Final Stage of Cholinergic Differentiation Occurs Below Inner Hair Cells During Development of the Rodent Cochlea

To gain further insights into the cholinergic differentiation of presynaptic efferent terminals in the inner ear, we investigated the expression of the high-affinity choline transporter (ChT1) in comparison to other presynaptic and cholinergic markers. In the adult mammalian cochlea, cholinergic axons from medial olivocochlear (OC) neurons form axosomatic synapses with outer hair cells (OHCs), whereas axons from lateral OC neurons form axodendritic synapses on afferent fibers below inner hair cells (IHCs). Mouse brain and cochlea homogenates reveal at least two ChT1 isoforms: a nonglycosylated ∼73 kDa protein and a glycosylated ∼45 kDa protein. In mouse brain, ChT1 is preferentially expressed by neurons in periolivary regions of the superior olive consistent with the location of medial OC neurons. In the adult mouse cochlea, ChT1-positive terminals are located almost exclusively below OHCs consistent with a medial OC innervation. Between postnatal day 2 (P2) and P4, ChT1-positive terminals are below IHCs and occur after the expression of growth-associated protein 43, synapsin, and the vesicular acetylcholine transporter. By P15, ChT1-positive terminals are mostly on OHCs. Accounting for differences in gestational age, the developmental expression of ChT1 in the rat cochlea is similar to the mouse. However, in older rats ChT1-positive terminals are below IHCs and OHCs. In both rat and mouse, our observations indicate that the onset of ChT1 expression occurs after efferent terminals are below IHCs and express other presynaptic and cholinergic markers. In the mouse, but not in the rat, ChT1 may preferentially identify medial OC neurons.     

A surgical approach to middle ear can preserve rat cochlear function

Peripheral sensitivity hearing loss is an inner ear disorder that is difficult to cure, and there may be two main reasons behind it.     

Does the type of middle ear aspirate have any prognostic significance in otitis media with effusion in children?

Two hundred and twenty-two children with chronic, bilateral middle ear effusions were assessed during a 2 year follow-up period. At initial myringotomy the middle ear aspirate was found to be serous in 44 children and mucoid in 178 children. Evaluation at 1 and 2 years post-operatively showed no difference in otoscopic fluid clearance or mean hearing threshold at either follow-up time in relation to either type of fluid. There was no greater need for ventilation tube reinsertion in either group during the overall follow-up period. There was found to be no significant difference between the children with serous or mucoid effusions in relation to a range of pre-operative and operative variables. The study suggests that outcome in terms of fluid clearance and hearing thresholds is independent of the fluid type and there appears no greater need for revision ventilation tube insertion in relation to the findings at myringotomy. The type of effusion found on aspiration prior to ventilation tube insertion has no prognostic value. Children with serous fluid should be managed in an identical manner to those in which the fluid is thicker and mucoid in character.     

The mobility of the malleus and incus with varying middle ear pressures

The mobility of the malleus and incus was studied in two fresh human temporal bones. Various pressure gradients were applied across the intact tympanic membrane and the movement of the ossicles examined, firstly with the incus in situ and secondly, with the incus removed. The displacement of the long process of the incus was less than 100 μm at the extremes of pressure gradient. However, this mobility increased by over twofold when the posterior incudal ligament was divided. With removal of the incus, the mobility of the umbo with pressure changes was further increased and can be as much as half a millimetre. In all cases the maximal rate of ossicular excursion was noted with pressure gradients of less than 100 daPa (mmH₂O) across the tympanic membrane.     

芥子气致小鼠耳廓皮肤损伤模型的建立

目的：构建芥子气所致小。鼠耳廓皮肤损伤模型，为研究芥子气皮肤损伤机制及筛选抗毒药物奠定基础。方法：采用小鼠耳廓称重法观察了16,32，64mg/ml芥子气5μl分别染毒后小鼠耳廓皮肤的水肿程度；通过光镜、电镜观察了32mg／ml芥子气5μl染毒后小鼠耳廓皮肤病理变化。结果：芥子气所致皮肤水肿具有剂量、时间效应；光镜下可见微疱、炎症、坏死等病理变化，电镜下可见基底膜结构紊乱、断裂等。结论：小鼠耳廓内侧皮肤以32mg／ml芥子气5μl染毒后，可构建出皮肤损伤模型。     

Growth of a fish ear: 1. Quantitative analysis of hair cell and ganglion cell proliferation

Proliferation (or addition) of inner ear sensory hair cells continues for a long time postembryonically in cartilaginous and bony fishes, and in amphibians. In contrast, proliferation only occurs during embryonic development in birds and mammals. However, detailed quantitative data on hair cell addition are not available for bony fishes. In order to quantify the extent of proliferation, we determined the number of sensory hair cells on the saccular sensory epithelium in specimens of the cichlid fish Astronotus ocellatus (the oscar) ranging from 2.0 to 19.0 cm in standard length (0.9-343 g). Ganglion cells were counted using serial sections of the saccular branch of the eighth nerve in animals of the same size range. The saccular macula of a 2.0 cm long (0.9 g) Astronotus contains approximately 5500 sensory hair cells; fish from 16 to 19 cm long have over 170 000 hair cells. The increase in number of sensory cells and the increase in both length and weight of the animals studied were statistically correlated (r2 = 0.8). The relative densities of saccular sensory cells in different epithelial regions remained constant in animals from 2.0 to 17 cm; in larger animals the cell density decreased somewhat. Based upon very conservative estimates of the rate of growth of Astronotus, we calculate that an average of 167 hair cells/day are added during the time when the cell population of the saccule increases. Ganglion cell number also increased approximately 4.8 times in the range of fish studied. The smallest animals in our study had about 150 ganglion cells per saccular epithelium, while the largest fish had over 600 ganglion cells. We estimate that the average ratio of hair cells to afferent fibers increases from about 30:1 in the smallest fish to over 300:1 in the largest animals.     

先天性内耳畸形致脑脊液耳鼻漏三例报告

先天性内耳畸形致病脑脊液耳漏引起反复发作性脑膜炎3例，该3例患者均有脑脊液耳漏，患耳完全性耳聋，患侧前庭功能减退或消失，经采用手术修补瘘道治疗，术后效果满意，本文就先天性内耳畸形致脊液耳漏的病因，诊断、瘘道的部位以及手术治疗方法进行了探讨。