A 3000-year-old founder variant in the DRC1 gene causes primary ciliary dyskinesia in Japan and Korea.

Primary ciliary dyskinesia (PCD) is a genetic disorder characterized by ciliary structural abnormalities and dysfunction, leading to chronic rhinosinusitis, otitis media with effusion, bronchiectasis, and infertility. Approximately half of Japanese PCD cases are attributed to variants in the dynein regulatory complex subunit 1 (DRC1) gene, predominantly featuring homogeneous deletions of exons 1-4 spanning 27,748 base pairs on chromosome 2. Here, we report 10 new PCD cases (9 families) in addition to 29 previously reported cases (24 families) caused by DRC1 variants. Among these 39 cases, biallelic DRC1 exon 1-4 deletions were detected in 38 (97.4%). These DRC1 deletions exhibited an identical breakpoint in all PCD cases in the Japanese and Korean populations, strongly suggesting a founder effect. In this study, we performed haplotype analysis, using a whole-exome sequencing dataset of 18 Japanese PCD patients harboring large biallelic DRC1 deletions. We estimated that the founder allele likely emerged 115.1 generations ago (95% confidence interval: 33.7-205.1), suggesting an origin of approximately 3050 years ago, coinciding with the transition from the Jomon period to the early Yayoi period in Japan. Considering the formation of the modern Japanese population, the founder with the DRC1 exon 1-4 deletion likely lived on the Korean peninsula, with the allele later transmitted to Japan through migration. This study provides insights into the origin of the DRC1 copy number variant, the most frequent PCD variant in the Japanese and Korean populations, highlighting the importance of understanding population-specific genetic variations in the context of human migration and disease prevalence.

Primary Ciliary Dyskinesia with Identical Genotype but Distinct Phenotypes in Two Siblings.

In this study, we report two cases of siblings diagnosed with primary ciliary dyskinesia (PCD) sharing an identical genotype yet exhibiting distinct phenotypes. A 13-year-old girl with acute pneumonia was admitted to our hospital. Chest and sinus radiography revealed situs inversus and bilateral maxillary sinusitis. Chest computed tomography revealed bronchiectasis. Her 6-year-old brother with acute bronchitis was admitted and was diagnosed with bronchial asthma due to recurrent wheezing. Unlike his sister, he did not have situs inversus. Both patients had a chronic wet cough and were diagnosed with bronchial asthma by their family doctor. The mean PCD rule (PICADAR) scores were 9 and 7, respectively. Genetic analysis confirmed the presence of the same homozygous mutation (c.546C > A,pTyr182Ter) in DNAI2. To date, there have been four reports of the same pathogenic variants but different PCD phenotypes. Pathological variants of DNAI2 cause the loss of the outer dynein arm, the absence of which results in a lack of primary ciliary movement involved in the left-right axis formation during the embryonic period. A lack of functional cilia results in randomized visceral asymmetry; hence, the same pathogenic variant may exhibit different phenotypes. PCD is often overlooked and is sometimes managed as bronchial asthma, as in these siblings. In our case, the PICADAR score was useful in predicting the clinical diagnosis of PCD.

Characteristic genetic spectrum of primary ciliary dyskinesia in Japanese patients and global ethnic heterogeneity: population-based genomic variation database analysis.

Primary ciliary dyskinesia (PCD) is a hereditary disease caused by pathogenic variants in genes associated with motile cilia. Some variants responsible for PCD are reported to be ethnic-specific or geographical-specific. To identify the responsible PCD variants of Japanese PCD patients, we performed next-generation sequencing of a panel of 32 PCD genes or whole-exome sequencing in 26 newly identified Japanese PCD families. We then combined their genetic data with those from 40 Japanese PCD families reported previously, for an overall analysis of 66 unrelated Japanese PCD families. We conducted Genome Aggregation Database and TogoVar database analyses to reveal the PCD genetic spectrum of the Japanese population and compare with other ethnic groups worldwide. We identified 22 unreported variants among the 31 patients in the 26 newly identified PCD families, including 17 deleterious variants estimated to cause lack of transcription or nonsense-mediated mRNA decay and 5 missense mutations. In all 76 PCD patients from the 66 Japanese families, we identified 53 variants on 141 alleles in total. Copy number variation in DRC1 is the most frequent variant in Japanese PCD patients, followed by DNAH5 c.9018C>T. We found 30 variants specific to the Japanese population, of which 22 are novel. Furthermore, 11 responsible variants in the Japanese PCD patients are common in East Asian populations, while some variants are more frequent in other ethnic groups. In conclusion, PCD is genetically heterogeneous between different ethnicities, and Japanese PCD patients have a characteristic genetic spectrum.

Knockdown of TFRC suppressed the progression of nasopharyngeal carcinoma by downregulating the PI3K/Akt/mTOR pathway.

BACKGROUND: The transferrin receptor (TfR) encoded by TFRC gene is the main cellular iron importer. TfR is highly expressed in many cancers and is expected to be a promising new target for cancer therapy; however, its role in nasopharyngeal carcinoma (NPC) remains unknown. METHODS: The TfR levels were investigated in NPC tissues and cell lines using immunohistochemistry and reverse transcription-quantitative polymerase chain reaction. Knockdown of TFRC using two siRNA to investigate the effects on intracellular iron level and biological functions, including proliferation by CKK-8 assay, colony formation, cell apoptosis and cell cycle by flow cytometry, migration and invasion, and tumor growth in vivo by nude mouse xenografts. RNA sequencing was performed to find possible mechanism after TFRC knockdown on NPC cells and further verified by western blotting. RESULTS: TfR was overexpressed in NPC cell lines and tissues. Knockdown of TFRC inhibited cell proliferation concomitant with increased apoptosis and cell cycle arrest, and it decreased intracellular iron, colony formation, migration, invasion, and epithelial-mesenchymal transition in HK1-EBV cells. Western blotting showed that TFRC knockdown suppressed the levels of the iron storage protein FTH1, anti-apoptotic marker BCL-xL, and epithelial-mesenchymal transition markers. We confirmed in vivo that TFRC knockdown also inhibited NPC tumor growth and decreased Ki67 expression in tumor tissues of nude mouse xenografts. RNA sequencing and western blotting revealed that TFRC silencing inhibited the PI3K/Akt/mTOR signaling pathway. CONCLUSIONS: These results indicated that TfR was overexpressed in NPC, and TFRC knockdown inhibited NPC progression by suppressing the PI3K/Akt/mTOR signaling pathway. Thus, TfR may serve as a novel biomarker and therapeutic target for NPC.

GDF10 inhibits cell proliferation and epithelial-mesenchymal transition in nasopharyngeal carcinoma by the transforming growth factor-ß/Smad and NF-κB pathways.

Growth differentiation factor-10 (GDF10) belongs to a member of the transforming growth factor-ß (TGF-ß) superfamily. Dysfunction of the TGF-ß pathway can lead to carcinoma progression. Previous studies have shown that GDF10 acts as a tumor suppressor gene in some cancers. However, the molecular mechanisms of the association between GDF10 and cell functions in nasopharyngeal carcinoma (NPC) remain unclear. In this study, the expression and methylation levels of GDF10 were studied in human subjects and cell lines. Furthermore, overexpression of GDF10 was used to explore its biological function and potential mechanism in NPC cell lines. GDF10 was downregulated in NPC owing to its aberrant promoter methylation. After treatment with 5-aza-2'-deoxycytidine, the expression of GDF10 in NPC cells was reversed. We also confirmed that the overexpression of GDF10 significantly inhibited cell proliferation and tumor growth both in vitro and in vivo, respectively. Additionally, GDF10 overexpression in NPC cells attenuated migration and invasion and inhibited epithelial-to-mesenchymal transition with a decrease in nuclear Smad2 and NF-κB protein accumulation. GDF10 was silenced owing to its promoter hypermethylation, and it might originally act as a functional tumor suppressor via TGF-ß/Smad and NF-κB signaling pathways in NPC.

Influence of Epstein-Barr virus and human papillomavirus infection on macrophage migration inhibitory factor and macrophage polarization in nasopharyngeal carcinoma.

BACKGROUND: To assess the effects of Epstein-Barr virus (EBV) and human papillomavirus (HPV) infection on the tumor microenvironment, we examined the relationship between viral infection status, macrophage migration inhibitory factor (MIF), and tumor-associated macrophages in nasopharyngeal carcinoma (NPC). METHODS: A tissue microarray containing 150 cores from 90 patients with NPC and six with chronic inflammation was used. EBV and HPV status were detected using in situ hybridization with commercial EBER1 and HPV16/18 probes. Immunofluorescence double staining of MIF, pan-macrophage marker CD68, M1 macrophage marker CD11c, and M2 macrophage marker CD163 were analyzed using the same tissue microarray. The levels of these markers between NPC and inflammation cases and between tumor nests and stroma were compared. Correlations among these markers were analyzed. RESULTS: We found EBER1(+) cases in 90% of NPC patients, including 10% EBV/HPV co-infection. M1 macrophages mainly infiltrated the tumor nest, while M2 macrophages infiltrated the tumor stroma. We found a significant positive correlation between EBER1 levels and MIF levels in tumor nests and a significant positive correlation between HPV16/18 and CD11c(+) cell levels in NPC tissues. CONCLUSIONS: It is suggested that MIF is associated with EBV, and M1 macrophage infiltration is affected by HPV status in NPC.

Combination of RERG and ZNF671 methylation rates in circulating cell-free DNA: A novel biomarker for screening of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a prevalent malignancy in Southeast Asia, hence, identifying easily detectable biomarkers for NPC screening is essential for better diagnosis and prognosis. Using genome-wide and targeted analyses based on next-generation sequencing approaches, we previously showed that gene promoters are hypermethylated in NPC tissues. To confirm whether DNA methylation rates of genes could be used as biomarkers for NPC screening, 79 histologically diagnosed NPC patients and 29 noncancer patients were recruited. A convenient quantitative analysis of DNA methylation using real-time PCR (qAMP) was carried out, involving pretreatment of tissue DNA, and circulating cell-free DNA (ccfDNA) from nonhemolytic plasma, with methylation-sensitive and/or methylation-dependent restriction enzymes. The qAMP analyses revealed that methylation rates of RERG, ZNF671, ITGA4, and SHISA3 were significantly higher in NPC primary tumor tissues compared to noncancerous tissues, with sufficient diagnostic accuracy of the area under receiver operating characteristic curves (AUC). Interestingly, higher methylation rates of RERG in ccfDNA were statistically significant and yielded a very good AUC; however, those of ZNF671, ITGA4, and SHISA3 were not significant. Furthermore, the combination of methylation rates of RERG and ZNF671 in ccfDNA showed higher diagnostic accuracy than either of them individually. In conclusion, the methylation rates of specific genes in ccfDNA can serve as novel biomarkers for early detection and screening of NPC.

A longitudinal study on circulating miR-21 as a therapeutic effect marker in head and neck squamous cell carcinoma.

The aim of the study is to investigate plasma miR-21 for a possible therapeutic effect determination marker in head and neck squamous cell carcinoma (HNSCC). Plasma samples are obtained from 86 HNSCC patients and 29 non-cancer volunteers who had been treated at Mie University Hospital between May 2015 and December 2016, and plasma miR-21 expression was measured using real-time quantitative reverse transcription polymerase chain reaction. In addition, plasma miR-21 level of advanced HNSCC patients including 22 non-recurrent cases and 11 recurrent cases before and after treatment was analyzed using a longitudinal design. Plasma miR-21 expression in 86 HNSCC patients was obviously higher than in 29 control patients (P < 0.0001). The area under the curve (AUC) for plasma miR-21 was 0.756 (95% confidence interval: 0.661-0.851). Furthermore, our longitudinal study of plasma miR-21 showed that the expression level of plasma miR-21 was significantly reduced at the time point of 2 months after treatment in case of no recurrence. On the other hand, plasma miR-21 was not decreased after treatment in case of 10 patients who had developed recurrences during the follow-up period. This study may provide new insights into the role of plasma miR-21 as a biomarker for HNSCC, and plasma miR-21 would be useful for early detection of tumor recurrence after operation or chemoradiotherapy.

Encouragements for the Use of Microwaves in Industrial Chemistry.

Microwave travels at the speed of light, and transfers energy solely to materials. This holds great promise for energy conservation in industrial processes. However, due to differences with common heating principles, and misunderstanding of the correct way to handle them, the effectiveness of microwaves has been underestimated, and development of technologies using microwaves often stops due to this. This paper has focused on the use of microwave heating for organic/polymer synthesis, specifically for a highly effective condensation reaction and for use with ionic reactants. In addition to covering the process of ascertaining which reactions are suitable for the application of microwave heating, and introducing studies on scaling these up, this paper covers points of caution, especially those relating to the all-important measurement/control of temperature. Based on their accumulation of expertise in the area, the authors present the design for equipment/plants for industrial use and introduce their research into the practical application of such technology.

Anti-Cancer Mechanisms of Taurine in Human Nasopharyngeal Carcinoma Cells.

Taurine displays anti-tumor activity in some kinds of human cancers. However, the underlying mechanisms are poorly understood. Epstein-Barr virus-related nasopharyngeal carcinoma (NPC) is a distinctive type of head and neck cancer in Southeast Asia with the highest incidence in South China. We examined an apoptosis-inducing effect of taurine against NPC cells (HK1 and HK1-EBV) to clarify the mechanisms of anti-tumor effects of taurine by immunocytochemical methods. We observed that taurine induced cleavage of caspase-9/3 in a concentration-dependent manner, suggesting the involvement of mitochondrial apoptotic signals. Both PTEN and p53 activation were detected in a dose-dependent manner after taurine treatment in NPC cells. In conclusion, taurine may play an anti-tumor role by activating tumor suppressor PTEN and p53.

Analysis of factors associated with cedar pollen sensitization and development of pollinosis in a young Japanese adult population.

BACKGROUND: Genetic and environmental factors are proposed to be involved in cedar pollen allergy sensitization and onset. The impact of these factors will provide key information for the prevention of cedar pollen sensitization and allergy onset, which we investigated in this cross-sectional study. METHODS: Subjects were 382 young adult volunteers who completed a self-administered questionnaire on self-reported subjective symptoms of pollinosis, physician-diagnosed pollinosis, and background factors. We also measured their serum IgE antibody titers specific for cedar, cypress, and mites. Factors associated with subjective symptoms, physician diagnosis, and the three specific antigens were determined using both univariate and multivariate analyses. RESULTS: Sensitization to cedar, cypress, and mites, defined as specific IgE levels of class 1 or above, was found in 78.8%, 64.4%, and 56.0% of subjects, respectively. The prevalence of cedar pollinosis was 41.2% based on subjective symptoms and 22.2% based on physician diagnosis. Factors associated with increased cedar pollen sensitization were mite sensitization, comorbid allergic rhinitis, and family history of cedar pollinosis. Risk-reducing factors for cedar pollen sensitization were keeping a cat, number of common colds, and hours of sleep. Risk-increasing factors for both subjective pollinosis symptoms and physician-diagnosed pollinosis were comorbid allergic rhinitis and family history of cedar pollinosis. CONCLUSIONS: Sensitization to cedar pollen in this population was extremely high. Both common and distinct factors were associated with sensitization to pollen and with the development of pollinosis. The distinct factors were associated with sensitization to cedar and cypress antigens.

Anti-high mobility group box 1 antibody suppresses local inflammatory reaction and facilitates olfactory nerve recovery following injury.

BACKGROUND: Refractory olfactory dysfunction is a common finding in head trauma due to olfactory nerve injury. Anti-inflammatory treatment using steroids is known to contribute to functional recovery of the central and peripheral nervous systems in injury models, while there is a concern that steroids can induce side effects. The present study examines if the inhibition of proinflammatory cytokine, high mobility group box 1 (HMGB1), can facilitate olfactory functional recovery following injury. METHODS: Olfactory nerve transection (NTx) was performed in OMP-tau-lacZ mice to establish injury models. We measured HMGB1 gene expression in the olfactory bulb using semi-quantitative polymerase chain reaction (PCR) assays and examined HMGB1 protein localization in the olfactory bulb using immunohistochemical staining. Anti-HMGB1 antibody was intraperitoneally injected immediately after the NTx and histological assessment of recovery within the olfactory bulb was performed at 5, 14, 42, and 100 days after the drug injection. X-gal staining labeled OMP in the degenerating and regenerating olfactory nerve fibers, and immunohistochemical staining detected the presence of reactive astrocytes and macrophages/microglia. Olfactory function was assessed using both an olfactory avoidance behavioral test and evoked potential recording. RESULTS: HMGB1 gene and protein were significantly expressed in the olfactory bulb 12 h after NTx. Anti-HMGB1 antibody-injected mice showed significantly smaller areas of injury-associated tissue, fewer astrocytes and macrophages/microglia and an increase in regenerating nerve fibers. Both an olfactory avoidance behavioral test and evoked potential recordings showed improved functional recovery in the anti-HMGB1 antibody-injected mice. CONCLUSIONS: These findings suggest that inhibition of HMGB1 could provide a new therapeutic strategy for the treatment of olfactory dysfunction following head injuries.

Taurine exhibits an apoptosis-inducing effect on human nasopharyngeal carcinoma cells through PTEN/Akt pathways in vitro.

Nasopharyngeal carcinoma (NPC) is a distinctive type of head and neck malignancy with a high incidence in southern China. Previous studies have confirmed that taurine shows an anti-cancer effect on a variety of human tumors by inhibiting cell proliferation and inducing apoptosis. However, the underlying molecular mechanism of its anti-cancer effect on NPC is not well understood. To clarify these anti-cancer mechanisms, we performed cell viability and colony formation assays. Apoptotic cells were quantified by flow cytometry. The expression levels of apoptosis-related proteins were evaluated by Western blot. The results showed that taurine markedly inhibited cell proliferation in NPC cells, but only slightly in an immortalized normal nasopharyngeal cell line. Taurine suppressed colony formation and induced apoptosis of NPC cell lines in a dose-dependent manner. Furthermore, taurine increased the active form of caspase-9/3 in a dose-dependent manner. Taurine down-regulated the anti-apoptotic protein Bcl-xL and up-regulated the pro-apoptotic protein Bax and GRP78, a major endoplasmic reticulum (ER) chaperone. These results suggest the involvement of mitochondrial and ER stress signaling in apoptosis. In addition, taurine increased the levels of PTEN (phosphatase and tensin homolog deleted on chromosome 10) and p53, and reduced phosphorylated Akt (protein kinase B). In conclusion, taurine may inhibit cell proliferation and induce apoptosis in NPC through PTEN activation with concomitant Akt inactivation.

Interactions between bradykinin and plasmin in the endothelial Ca2+ response.

Plasmin is a fibrinolytic factor and a serine protease that activates protease-activated receptors (PARs) to produce endothelium-derived relaxing factors such as nitric oxide and prostacyclin. Nitric oxide and prostacyclin production is regulated, at least in part, by the intracellular Ca2+ concentration in various blood vessel types. Bradykinin and plasmin stimulate vascular endothelial cells and work simultaneously in pathophysiological conditions such as thrombosis and inflammation. Here, we explored the interactions between bradykinin and plasmin in the endothelial Ca2+ response using the fluorescent indicator, Fura-2/AM, in primary cultures of porcine aortic endothelial cells (PAECs). Plasmin (0.15-15 µg/ml) and bradykinin (0.1-10 nM) increased intracellular Ca2+ concentrations in PAECs in a dose-dependent manner, and the plasmin-induced endothelial Ca2+ response occurred only once. Bradykinin (0.1-10 nM) inhibited the plasmin-induced endothelial Ca2+ response in a dose-dependent manner, however, plasmin did not affect the bradykinin-induced endothelial Ca2+ response. Pretreatment with gabexate mesilate (GM, 100 µM), a serine protease inhibitor, that blocks plasmin's proteolytic activity, fully suppressed the plasmin-induced Ca2+ response. After washout of GM and the first plasmin, the second administration of plasmin caused Ca2+ increases. However, when the first plasmin-induced Ca2+ response was blocked by pretreatment with bradykinin, the second plasmin (15 µg/ml) application did not cause any Ca2+ response, even 30 min after the washout of the first plasmin and bradykinin. Our data suggested that bradykinin regulated the plasmin-induced endothelial Ca2+ response by inhibiting the pathway downstream of the PARs' N-terminus cleavage.

Interleukin-33 induces mucin gene expression and goblet cell hyperplasia in human nasal epithelial cells.

We investigated whether IL-33 is involved in mucus overproduction and goblet cell hyperplasia in eosinophilic chronic rhinosinusitis (ECRS). IL-33 mRNA was significantly higher in the eosinophilic CRS group than in the non-eosinophilic CRS group from human nasal polyps. IL-33 induced MUC5AC mRNA and MUC5AC protein, and also goblet cell hyperplasia at air liquid interface culture in human nasal epithelial cells. In addition to that, IL-33 induced MUC5B and FOXA3, and reduces FOXJmRNA. In conclusion, our present study demonstrated that the direct evidence of IL-33 which lead to increase mucin gene and protein expression, as well as goblet cell hyperplasia. This study provides novel insights into the role of IL-33 on mucus overproduction in eosinophilic inflammation of human airways.

Quantitation of DNA methylation in Epstein-Barr virus-associated nasopharyngeal carcinoma by bisulfite amplicon sequencing.

BACKGROUND: Epigenetic changes, including DNA methylation, disrupt normal cell function, thus contributing to multiple steps of carcinogenesis. Nasopharyngeal carcinoma (NPC) is endemic in southern China and is highly associated with Epstein-Barr virus (EBV) infection. Significant changes of the host cell methylome are observed in EBV-associated NPC with cancer development. Epigenetic marks for NPC diagnosis are urgently needed. In order to explore DNA methylation marks, we investigated DNA methylation of candidate genes in EBV-associated nasopharyngeal carcinoma. METHODS: We first employed methyl-capture sequencing and cDNA microarrays to compare the genome-wide methylation profiles of seven NPC tissues and five non-cancer nasopharyngeal epithelium (NNE) tissues. We found 150 hypermethylated CpG islands spanning promoter regions and down-regulated genes. Furthermore, we quantified the methylation rates of seven candidate genes using bisulfite amplicon sequencing for nine NPC and nine NNE tissues. RESULTS: All seven candidate genes showed significantly higher methylation rates in NPC than in NNE tissues, and the ratios (NPC/NNE) were in descending order as follows: ITGA4 > RERG > ZNF671 > SHISA3 > ZNF549 > CR2 > RRAD. In particular, methylation levels of ITGA4, RERG, and ZNF671 could distinguish NPC patients from NNE subjects. CONCLUSIONS: We identified the DNA methylation rates of previously unidentified NPC candidate genes. The combination of genome-wide and targeted methylation profiling by next-generation sequencers should provide useful information regarding cancer-specific aberrant methylation.

Oxytetracycline Inhibits Mucus Secretion and Inflammation in Human Airway Epithelial Cells.

Oxytetracycline is a broad-spectrum antibiotic, but its nonantibacterial effects in the human respiratory tract are unknown. In this study, the effects of oxytetracycline on mucus secretion and inflammation were examined by PCR and ELISA in the human airway epithelial cell line NCI-H292. Oxytetracycline (10 µg/mL) significantly inhibited TNF-α-induced MUC5AC gene expression and MUC5AC protein levels in NCI-H292 cells. It also downregulated IL-8 and IL-1ß gene expression and IL-1ß protein levels. Our findings demonstrated that oxytetracycline suppressed mucus production and inflammation in human respiratory epithelial cells, providing further evidence for the usefulness of oxytetracycline for human airway inflammatory diseases.

Endoscopic electrocauterization of pyriform sinus fistula.

To determine the efficacy of endoscopic electrocauterization for pyriform sinus fistula (PSF) using a flexible Bugbee cautery electrode. From 2009 to 2016, a total of eight patients with acute suppurative thyroiditis or cervical abscess secondary to PSF were retrospectively registered in our study (three males, five females; median age 6.5 years). All patients underwent endoscopic electrocauterization as treatment for PSF. Six of eight patients had no recurrence after the initial endoscopic electrocauterization of PSF. One patient with recurrence developed symptoms 9 days after cauterization and another experienced recurrence after 2 years. Mean follow-up for the eight patients was 50 months (range 5-96 months). No post-operative complication was reported. Endoscopic electrocauterization appears to be a less-invasive, safe, and effective method for the treatment of PSF.

Sonographic appearance of pyomyositis of the sternocleidomastoid muscle: A case report.

Pyomyositis in the neck has rarely been described. We present the sonographic findings in a case of pyomyositis of the sternocleidomastoid muscle. A 62-year-old man with poorly controlled diabetes presented with an induration of the neck and fever. On gray-scale sonography, a part of the sternocleidomastoid muscle appeared swollen and contained irregularly shaped hypoechoic areas. Power Doppler imaging showed increased vascularity in the muscle. Sonographic-guided aspiration confirmed abscesses in the sternocleidomastoid muscle. Surgical drainage was successfully performed along with antibiotic treatment. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:520-523, 2017.

Sonographic diagnosis of acute mastoiditis and subsequent retroauricular abscess in a pediatric cochlear implant recipient: A case report.

When acute mastoiditis occurs in cochlear implant recipients, it can progress to subsequent retroauricular abscess due to the absence of the external mastoid cortex resulting from mastoidectomy performed for cochlear implantation. The management goal is to control infection while preserving the implanted device. A 2-year-old boy with cochlear implants developed acute mastoiditis and a subsequent retroauricular abscess. The patient underwent a surgical intervention based on the diagnosis made utilizing gray-scale and power Doppler sonography. This case illustrates the diagnostic usefulness of sonography in this rare situation. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:515-519, 2017.