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To investigate the hearing loss and morphological changes caused by cisplatin in rats. In vivo, cisplatin was injected intraperitoneally for seven consecutive days to observe the hearing loss of different age through the detection of auditory brainstem reaction. Cochleae were taken after hearing measurement, and the morphological changes of the cochlear hair cells and spiral ganglion neurons were observed by immunofluorescence staining of the basilar membrane and cochlear frozen section. In vitro, the effects of cisplatin on hair cells and spiral ganglion neurons were observed by immunofluorescence staining of cochlear organotypic cultures. Cisplatin had ototoxicity and could cause hearing loss in rats. The damage of high-frequency hearing performance was more serious. Moreover, the hearing loss was different in the rats of different postnatal days, and the rats of younger days were more sensitive to cisplatin ototoxicity. In vivo, hearing loss induced by cisplatin resulted in loss of cochlear hair cells in rats, but no significant loss of spiral ganglion neurons was observed, nor were Cleaved caspase-3 positive spiral ganglion neurons found. In vitro, cisplatin ototoxicity caused significant damage to both hair cells and spiral ganglion neurons. Both in vivo and in vitro experiments can establish a stable cisplatin-induced hearing loss model in rats, which will lay a foundation for the study on the mechanism and protection of cisplatin induced cochlear hair cells. [ABSTRACT FROM AUTHOR]

Laminin 332 is a major component of the basement membrane in epithelial tissues and plays roles in the adhesion, migration and differentiation of epithelial cells. Laminin 332 consists of three different gene products, α3, β3 and γ2 chains, resulting in a heterotrimeric glycoprotein. Laminin 332 is synthesized by epithelial cells as a precursor. After secretion into the extracellular matrix, the α3 and γ2 chains undergo specific proteolytic processing to produce a mature form. Under the physiological condition, the key function of laminin 332 is sustaining the stable adhesion of epithelial cells to the underlying basement membrane in epithelial tissues. Laminin 332 has been shown to be highly expressed in various types of human malignant tumors and correlate well with tumor occurrence and development. The article is intended to review the structure of laminin 332, its relationship with malignant tumors and research progresses with gynecological tumors. [ABSTRACT FROM AUTHOR]

The cochlea is the most precise mechanical component in a human body. With frequencies from dozens to thousands of Hertz, acoustic signals can be processed by the cochlea and captured by the sensory hair cells on the basilar membrane (BM). Experimental research shows that sound waves of different frequencies are scattered at different positions along the basilar membrane as a natural Fourier filter. Based on Manoussaki's D fluid-solid coupling model for the spiral cochlear basilar membrane and in addition according to the longitudinal gradients of the cochlear duct height and the BM stiffness, a dispersion equation for the acoustic wave propagation along the basilar membrane was deduced. The influences of the duct height and the BM stiffness on the dispersion characteristics were analyzed. It is found that existence of the cochlear endolymph greatly increases the low-frequency signal processing ability, and the capture frequency reduces with the decreases of both the BM stiffness and the duct height. Finally, examples of human, gerbil and guinea pig were empirically studied for verification. Frequency-position diagrams corresponding to the animals respectively were obtained to prove the correctness of the proposed dispersion model, and reveal the relationship between the biological adaptability and the function of cochlear dispersion. This study is not only beneficial to understanding of the cochlear function but also promising to lay a theoretical basis for the development and design of sound sensors. [ABSTRACT FROM AUTHOR]

Objective: To measure the cochlear compound action potential (CAP) and the densities of hair cells (HCs) along the whole length of the basilar membrane (BM) in adult chinchillas. And to investigate the relationship between the severity of inner hair cells (IHCs) loss and the changes of CAP by using carboplatin-cochlear lesion model. Methods: Totally 18 chinchillas were recruited after ontological evaluation. They were randomly divided into three groups (with 6 subjects in each), A: control, B and C: legion groups treated with one or two shot(s) of carboplatin respectively (76 mg/kg in one shot, i.p., one-week interval between the two shots). Endpoint tests were performed 30 days after the carboplatin treatment in groups B and C, and matched time in group A. A sliver-ball electrode was placed into round window niche via hypotympanic approach in anesthetized chinchilla. CAP was measured in response to clicks and tone burst of 0.5, 1, 2, 4, 8, 16 kHz respectively under anesthesia. CAP amplitudes and thresholds were measured and compared across the groups. After the recording, the whole cochlea surface preparation was made and the HCs were stained in histochemistry against substrate of succinate dehydrogenase (SDH). Images were taken with high-resolution digital camera under light microscope and across the whole cochlea. The length of the basilar membrane (BM) and the number of both IHCs and OHCs were counted. The HC density was calculated as the number of HCs per 10% BM length. Results: The CAP thresholds were (7.1±2.6), (25.4±5.0), (24.6±5.4), (10.4±5.0), (0.4±1.4), (4.2±6.3) and (17.1±14.1) dB SPL (from 6 subjects in group A, n= 12 ears) corresponding to stimuli of Click and 0.5, 1, 2, 4, 8, 16 kHz tone bursts respectively. The total number of cochlear HCs were measured as (8 936±643) ( x ± s ) and the average length of the BMs was (17.73±1.012) mm from the six subjects in the group A ( n= 12 ears). The HC density was found to be varied slightly across the BM. There was no significant CAP threshold difference between the control (group A) and the group B, which received one shot of carboplatin. However, the maximal CAP amplitude was reduced by 40% in the group B and compared with group A. Correspondingly, approximately 40% loss of IHCs were seen. In contrast, a significant CAP threshold shift was seen in subjects receiving two shots of carboplatin (group C), which was accompanied by a loss of 90% IHCs. Conclusions: The CAP thresholds of adult chinchillas show typical open-V shape with the lowest values at 2, 4, and 8 kHz. IHC loss by carboplatin in certain degree is well correlated with CAP amplitude reduction, but does not change the threshold when inner hair cell loss reaches 40%, however, if inner hair cell loss exceeds 80%, the threshold shift of CAP will be inevitable.

Objective: To investigate the characteristics of morphological changes of inner retinal layer after internal limiting membrane peeling in macular hole surgery. Methods: Retrospective case study. Patients with idiopathic macular hole from 2015 to 2018 underwent vitrectomy+internal limiting membrane peeling (inverting)+ gas tamponade in China-Japan Friendship Hospital were investigated. A total of 19 eyes (17 patients) were enrolled, including 4 males (4 eyes) and 13 females (15 eyes). The average age was 62.74±5.25 years. Optical coherence tomography (OCT) was used to obtain the topographic maps of retinal thickness, the thickness of retinal ganglion cell complex and probability maps, and the Angio/en-face maps of macular retina. The characteristics of the morphological changes of the inner retinal were comprehensively analyzed. Results: Among 19 eyes, 9 eyes had internal limiting membrane peeling, 8 eyes had lotus-like internal limiting membrane inverting, and 2 eyes had the uper180 degrees internal limiting membrane inverting. The minimum diameter of macular hole was (543.06+220.17) μm and the maximum diameter was (947.18+319.12) μm. The follow-up time was (21.05+9.66) months, and the visual acuity was 0.45+0.35 at the last follow-up. In the 19 eyes, all the macular holes were closed postoperatively and dissociated optic nerve fiber layer appearance (DONFL) and concentric macular dark spots (CMDS) all showed, as well as mGCC thinning. The changes of CMDS and mGCC in 2 eyes in the uper180 degrees internal limiting membrane inverting group were mainly seen in the upper retina and in the remaining 17 eyes were seen diffused around the macula, which roughly corresponded to the extent of internal limiting membrane peeling. Two eyes showed clear decrease of retinal capillary density on Angio/map. Conclusions: Long-term morphological changes of the inner retinal after internal limiting membrane peeling in macular hole surgery are obvious. In addition to the appearance changes like DONFL and CMDS, the macular ganglion cell complex (mGCC) is also involved. (Chin J Ophthalmol, 2019, 55:747 - 756) .

Objective: To explore the relation between distortion products and frequency tuning charateristics in cochlear basilar membrane. Method: Time variances curves of distortion products and frequency tuning curves of basilar membrane response were measured by laser interferometery in situ guinea pig cochlea. Result: Response sensitivity and tuning sharpness of basilar membrane response decreased with distortion product amplitude and become most low and flat when distortion products disappeared. Conclusion: Distortion products in cochlea are related with hearing sensitivity and frequency tuning. They are indicator whether function of cochlear hearing sensitivity enhancing and frequency tuning sharpening is still at work., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)