Nationwide survey of middle ear cholesteatoma surgery cases in Japan: Results from the Japan Otological society registry using the JOS staging and classification system

ObjectiveThis study was aimed to determine the characteristics of middle ear cholesteatoma and to investigate short-term outcomes regarding the rates of residual and recurrent cholesteatoma and the postoperative hearing results in Japan, via a nationwide survey using staging and classification criteria for middle ear cholesteatoma, as proposed by the Japan Otological Society (JOS).MethodsThe first-round survey was conducted in 2016. The target was patients with middle ear cholesteatoma who were surgically treated in Japan between January and December 2015. Medical information on the patients was anonymized. The questionnaire entries were age, sex, cholesteatoma classification and stage, preoperative hearing level, mastoid development, status of the stapes, and surgical method. There were a total of 1,787 registered patients from 74 facilities from all over Japan. The second survey was conducted in January 2018 and received 1,456 responses from 49 facilities in Japan. Of the 1,456 cases, 1,060 were conducted in the postoperative hearing survey and 1,084 in the residual recurrence survey.ResultsThe most common cholesteatoma type was pars flaccida cholesteatoma (63.3%), followed by pars tensa cholesteatoma (13.0%), congenital cholesteatoma (12.9%), and cholesteatoma secondary to chronic tensa perforation (5.6%). Cholesteatoma of uncertain origin accounted for 5.0% (90 cases). Stage II was predominant in pars flaccida and pars tensa cholesteatoma, which frequently involves the mastoid, whereas about half of cases of cholesteatoma secondary to chronic tensa perforation and congenital cholesteatoma were classified as stage I. One hundred fifty-two of 1,084 cases (14.0%) had recurrent cholesteatoma, residual cholesteatoma, or both following first surgeries. The postoperative rates of hearing success rate was 63.3%.ConclusionWe were able to clarify not only the current epidemiological status of middle ear cholesteatoma but also the current trends of cholesteatoma surgery in Japan. The development of a staging system by the JOS Committee serving an epidemiological database for international or time-dependent comparison. It is possible to use this staging system with reasonable reliability.     

Targeting Notch Signaling and Autophagy Increases Cytotoxicity in Glioblastoma Neurospheres

Glioblastomas are highly aggressive tumors that contain treatment resistant stem‐like cells. Therapies targeting developmental pathways such as Notch eliminate many neoplastic glioma cells, including those with stem cell features, but their efficacy can be limited by various mechanisms. One potential avenue for chemotherapeutic resistance is the induction of autophagy, but little is known how it might modulate the response to Notch inhibitors. We used the γ‐secretase inhibitor MRK003 to block Notch pathway activity in glioblastoma neurospheres and assessed its effects on autophagy. A dramatic, several fold increase of LC3B‐II/LC3B‐I autophagy marker was noted on western blots, along with the emergence of punctate LC3B immunostaining in cultured cells. By combining the late stage autophagy inhibitor chloroquine (CQ) with MRK003, a significant induction in apoptosis and reduction in growth was noted as compared to Notch inhibition alone. A similar beneficial effect on inhibition of cloogenicity in soft agar was seen using the combination treatment. These results demonstrated that pharmacological Notch blockade can induce protective autophagy in glioma neurospheres, resulting in chemoresistance, which can be abrogated by combination treatment with autophagy inhibitors.     

Liquid photocurable biodegradable copolymers: in vivo degradation of photocured poly(epsilon-caprolactone-co-trimethylene carbonate)

The present investigation was designed to test cellular toxicity of modern dentin adhesives. With the use of the products Ariston Liner, Etch & Prime 3.0, Optibond Solo, Prime & Bond NT, Scotchbond 1, and Syntac Sprint, test specimens were prepared according to the manufacturers' instructions and transferred into a culture medium. Eluates were obtained and pipetted onto fibroblast cultures, incubated, and subsequently stained. The respective cell densities and the numbers of normal, altered, and dead cells were determined and compared with control cell cultures. Statistical analysis of the data showed that all materials caused cytotoxic effects. Scotchbond 1 displayed the highest number of dead cells. The difference was statistically significant compared to Etch" 3.0, Optibond Solo, Prime&Bond NT, and the control. The lowest cell density was found for Scotchbond 1 and Ariston Liner. The difference was also statistically significant in comparison with Etch" 3.0, Optibond Solo, Prime&Bond NT, and the control. To conclude, all tested dentin adhesives caused cytotoxic reactions. Taking the limitations of an in vitro experiment into consideration, Prime&Bond NT, Optibond Solo, and Etch" 3.0 appear to be the most recommendable products, and Scotchbond 1 and Ariston Liner the least.     

Software‐assisted morphometric and phenotype analyses of human peripheral blood monocyte‐derived macrophages induced by a microenvironment model of human esophageal squamous cell carcinoma

Human macrophages play important roles in tumor promotion and are called tumor‐associated macrophages (TAMs). We previously demonstrated that human esophageal squamous cell carcinomas (ESCCs) contain TAMs and that these TAMs tend to have tumor‐supporting features. Here we exposed human macrophages to conditioned media of TE‐series human ESCC cell lines (TECMs) to generate an ESCC extracellular stimuli‐influenced TAM model. CD14⁺ peripheral blood monocytes (PBMos) from healthy donors were treated with M‐CSF and with additional IL‐4 or TECM exposure. Morphological changes of the cells and the induction of CD163/CD204 proteins were detected in the TECM‐exposed model TAMs by immunofluorescence. A software‐assisted immunofluorescent cell image analysis showed increased CD163/CD204 positivity in the model TAMs and a weak to moderate positive correlation between the cytoplasmic area and the sum fluorescent intensity of CD204. Morphological changes of the cells were significantly reflected by several cytomorphometric parameters. PBMos were elongated with M‐CSF treatment, then enlarged with TECM exposure. The cytoplasmic aspect ratio was decreased by M‐CSF treatment and slightly increased by TECM exposure. The nuclear‐cytoplasmic ratio decreased during the whole process of cell differentiation. This system is useful for quantitative assessments of TAM‐like morphological changes of macrophages and the induction of CD163/CD204 in a model ESCC microenvironment.     

Overexpression of Polycomb-group gene rae28 in cardiomyocytes does not complement abnormal cardiac morphogenesis in mice lacking rae28 but causes dilated cardiomyopathy

The Polycomb-group genes (PcG) are widely conserved from Drosophila to mammals and are required for maintaining positional information during development. The rae28 gene (rae28) is a member of the mouse PcG. Mice deficient in rae28 (rae28(-/-)) demonstrated that rae28 has a role not only in anteroposterior patterning but also in cardiac morphogenesis. In this study we generated transgenic mice with ubiquitous or cardiomyocyte-specific exogenous rae28 expression. Genetic complementation experiments with these transgenic mice showed that ubiquitous expression of rae28 could reverse the cardiac anomalies in rae28(-/-), whereas cardiomyocyte-specific expression of rae28 could not, suggesting that rae28 is involved in cardiac morphogenesis through a noncardiomyocyte pathway. Interestingly, however, cardiomyocyte-specific overexpression of rae28 caused dilated cardiomyopathy, which was associated with cardiomyocyte apoptosis, abnormal myofibrils, and severe heart failure. Cardiac expression of rae28 was predominant in the early embryonic stage, whereas that of the other PcG members was relatively constitutive. Because rae28 forms multimeric complexes with other PcG proteins in the nucleus, it is presumed that constitutive cardiomyocyte-specific rae28 overexpression impaired authentic PcG functions in the heart. rae28-induced dilated cardiomyopathy may thus provide a clue for clarifying the direct role of PcG in the maintenance of cardiomyocytes.     

Characterization and localization of side population cells in mouse skin

Recently, the detection of side population (SP) cells, which have the ability to strongly efflux Hoechst 33342 fluorescence dye, has attracted attention as a method of stem cell isolation. We identified SP cells from mouse skin using the same method as from bone marrow. This population almost completely disappeared after treatment with the calcium channel blocker verapamil. SP cells were mainly localized in the epidermis, with a few in the dermis. The ratio of SP cells decreased as the mouse became older. Surface marker analysis revealed that the sorted SP cells expressed alpha6-integrin, beta1-integrin, Sca-1, keratin 14, and keratin 19, which are proliferating and progenitor cell markers, at levels higher than in non-SP cells, while they expressed E-cadherin, CD34, and CD71 at lower levels. The expression of breast cancer resistance protein 1 (BCRP1), which participates in dye efflux, was expressed at high levels at both the protein and mRNA level in sorted SP cells. Immunohistochemical analysis showed that BCRP1 was expressed in the basal layers and hair bulge regions of mouse skin. BCRP1 mRNA was found in basal layers and hair follicles of newborn skin by in situ hybridization. These results indicate that the localization of BCRP1-positive cells is compatible with that of keratinocyte stem cells. Based on the close relationship between BCRP1 and the SP cell phenotype, we conclude that keratinocyte stem cells are closely related to the SP- or BCRP1-positive cells.     

IFN-gamma-producing human T cells directly induce osteoclastogenesis from human monocytes via the expression of RANKL

The current study explored our hypothesis that IFN-gamma-producing human T cells inhibit human osteoclast formation. Activated T cells derived from human PBMC were divided into IFN-gamma-producing T cells (IFN-gamma(+) T cells) and IFN-gamma-non-producing T cells (IFN-gamma(-) T cells). IFN-gamma(+) T cells were cultured with human monocytes in the presence of macrophage-CSF alone. The concentration of soluble receptor activator of NF-kappaB ligand (RANKL) and IFN-gamma, and the amount of membrane type RANKL expressed on T cells, were measured by ELISA. In the patients with early rheumatoid arthritis (RA) treated with non-steroidal anti-inflammatory drugs alone, CD4+ T cells expressing both IFN-gamma and RANKL were detected by flow cytometry. Surprisingly, IFN-gamma(+) T cells, but not IFN-gamma(-) T cells, induced osteoclastogenesis from monocytes, which was completely inhibited by adding osteoprotegerin and increased by adding anti-IFN-gamma antibodies. The levels of both soluble and membrane type RANKL were elevated in IFN-gamma(+) T cells. The ratio of CD4+ T cells expressing both IFN-gamma and RANKL in total CD4+ T cells from PBMC was elevated in RA patients. Contrary to our hypothesis, IFN-gamma(+) human T cells induced osteoclastogenesis through the expression of RANKL, suggesting that Th1 cells play a direct role in bone resorption in Th1 dominant diseases such as RA.     

Central command and the cutaneous vascular response to isometric exercise in heated humans

Cutaneous vascular conductance (CVC) decreases during isometric handgrip exercise in heat stressed individuals, and we hypothesized that central command is involved in this response. Seven subjects performed 2 min of isometric handgrip exercise (35% of maximal voluntary contraction) followed by postexercise ischaemia in normothermia and during heat stress (increase in internal temperature ∼1°C). To augment the contribution of central command independent of force generation, on a separate day the protocol was repeated following partial neuromuscular blockade (PNB; i.v. cisatracurium). Forearm skin blood flow was measured by laser-Doppler flowmetry, and CVC was the ratio of skin blood flow to mean arterial pressure. The PNB attenuated force production despite encouragement to attain the same workload. During the heat stress trials, isometric exercise decreased CVC by ∼12% for both conditions, but did not change CVC in either of the normothermic trials. During isometric exercise in the heat, the increase in mean arterial pressure (MAP) was greater during the control trial relative to the PNB trial (31.0 ± 9.8 versus 18.6 ± 6.4 mmHg, P < 0.01), while the elevation of heart rate tended to be lower (19.4 ± 10.4 versus 27.4 ± 8.1 b.p.m., P = 0.15). During postexercise ischaemia, CVC and MAP returned to pre-exercise levels in the PNB trial but remained reduced in the control trial. These findings suggest that central command, as well as muscle metabo-sensitive afferent stimulation, contributes to forearm cutaneous vascular responses in heat stressed humans.