Hiroyuki Mineta

Epidermal growth factor receptor status and persistent activation of Akt and p44/42 MAPK pathways correlate with the effect of cetuximab in head and neck and colon cancer cell lines.

ObjectiveThe aim of this study was to investigate the effect of epidermal growth factor receptor (EGFR) blockade on cell survival and on downstream signalling pathways using the monoclonal antibody cetuximab.MethodsWe used three colon cancer cell lines, of which one was EGFR-negative, and two head and neck squamous cell carcinoma (HNSCC) lines. EGFR expression and gene copy number were measured by immunohistochemistry and FISH analysis, respectively. The effect of cetuximab, irradiation or the combination of both on cell growth was estimated by SRB assay. Western blotting was used to determine the phosphorylation of intracellular signalling proteins and cell cycle phase distribution was measured by flow cytometry.ResultsThe addition of cetuximab had only limited effects on cell growth, with a maximum inhibition of approximately 30%, but was correlated with the amount of protein expression and gene copy number of EGFR. When combined with irradiation, the effect of cetuximab was only additive and not dependent on the inherent radio-sensitivity of the cell lines. Persistent phosphorylation of Akt and/or p44/42 MAPK was detected by western blot in all of the cell lines, whereas there was no phosphorylation of Jak2 or STAT3.ConclusionsNone of these factors alone could predict the sensitivity to cetuximab. Rather, the results suggest that it might be necessary to determine the activation status of several intracellular signalling proteins to better predict the sensitivity to cetuximab treatment.

Epidemiological analysis of nasopharyngeal carcinoma in the central region of Japan during the period from 1996 to 2005

OBJECTIVEnIt has become clear through epidemiological analysis that the incidence of cancers of the lung, liver, colon, and rectum are increasing in Japan every year. However, there have been few epidemiological analyses of nasopharyngeal carcinoma (NPC) in Japan. The aim of this study was to analyze the epidemiology and current incidence of NPC in the Chubu region of Japan during the period from 1996 to 2005.nnnMETHODSnTakeshita et al. conducted a similar investigation in the Chubu region 10 years ago, and, as a result, this is a comparative study. The Chubu region is the central region of Japanese main island. We researched NPC patients treated in hospitals in each prefecture over a 10-year period (1996-2005) using a questionnaire.nnnRESULTSnA total of 525 cases (male:385, female:134, unknown:6) were analyzed epidemiologically, histologically, serologically, and clinically in this study. The incidence per 10(5) population per year was 0.29. For the period of 1986-1995, the age-standardized incidence of NPC was 0.28 per 10(5) persons per year in Takeshitas report. There was no significant difference between the two periods. The ages of the patients ranged from 13 to 90 years. The mean age of was 55.2 years. On the basis of the World Health Organization (WHO) histological criteria, 36% of the patients were classified as WHO I, 27% as WHO II, and 37% as WHO III. Carcinoma was located in the posterosuperior region in 56%, lateral in 41%, and inferior in 3%. Tumor staging showed that 6% to belonged to stage I, 25% to stage II, 31% to stage III, and 38% to stage IV. A neck mass was present in 52% of the patients, ear symptoms in 48%, nasal symptoms in 27%, headaches in 10%, pharyngeal symptoms in 9%, ophthalmologic symptoms in 9%, and cranial neurological symptoms in 9%. The positive rates of serum titers of the antibodies to Epstein-Barr virus (EBV)-related antigens were calculated. The positive rate of anti-EBV-viral capsid antigen (VCA) immunoglobulin (Ig) G titers was 58.6%, that of anti-EBV-VCA IgA titers was 53.6%, and that of EBNA was 81%. The five-year survival rate for all patients was 67.6%, and that for those in stage I, II, III, and IV was 75%, 84%, 69%, and 53%, respectively. The five-year survival rate for stage IV was significantly lower than those for the other stages (P<0.05).nnnCONCLUSIONnThe age-standardized annual incidence of NPC in our survey was 0.29 per 10(5) persons per year, being relatively low and stable.

Specific localization of five phosphatidylcholine species in the cochlea by mass microscopy.

Phosphatidylcholine (PC), a phospholipid, is a basic structural component of cell membranes. PC species exhibit various binding patterns with fatty acids; however, the distributions of PC species have not been studied in the cochlea. In recent years, imaging mass spectrometry has been used as a biomolecular visualization technique in medical and biological sciences. We recently developed a ‘mass microscope’ consisting of a mass spectrometry imager with high spatial resolution equipped with an atmospheric-pressure matrix-assisted laser desorption/ionization and quadrupole ion trap time-of-flight analyzer. In this study, we applied the mass microscope to analyze cochlear tissue sections. The imager allowed visualization of the localization of PC species in each region of the cochlea. The structures of the PC species were determined using tandem mass spectrometry. PC(16:0/18:1) was highly localized in the organ of Corti and the stria vascularis. PC(16:0/18:2) was mainly observed in the spiral ligament. PC(16:0/16:1) was found primarily in the organ of Corti. These distributional differences may be associated with the cellular architecture of these cochlear regions.

Tortuous internal carotid artery presenting as a pharyngeal mass

BACKGROUNDnDeformities of the carotid artery are rare. Tortuosity, kinking and coiling of the internal carotid artery may be observed with advancing age. A tortuous internal carotid artery may cause an abnormal sensation in the throat. In the early twentieth century, there were several reported cases of fatal haemorrhage during pharyngeal surgical procedures, because this condition went undetected.nnnMETHOD AND RESULTSnWe present two cases of tortuosity of the right internal carotid artery. Both women complained of abnormal throat sensations. Endoscopic studies and radiological examinations revealed tortuous right internal carotid arteries presenting as pulsatile masses. A literature review revealed that, in most reported cases, this deformity occurred on the right side. We believe that the defect and its right-sided predominance can be attributed to anatomical influences and factors affecting blood pressure.nnnCONCLUSIONnIn most reported cases of tortuous internal carotid artery, the defect occurred on the right side and patients complained of an abnormal sensation in the throat. This information is useful in the diagnosis of this condition. It is important for otolaryngologists to recognise this anomaly, because fatal haemorrhage can occur in patients with this condition during surgical procedures on the pharynx.

Ultrastructural co-localization of cochlin and type II collagen in the rat semicircular canal.

Cochlin and type II collagen are major constituents of the inner ear extracellular matrix. To investigate the morphological relation of cochlin and type II collagen in the rat semicircular canal, immuno-electronmicroscopic analysis was performed using the post-embedding immunogold method. Immunolabeling for cochlin was detected in the fibrillar substance underlying the supporting epithelium of the sensory cells and beneath the epithelial cells facing the endolymph in the semicircular canals. Immunolabeling for type II collagen was observed in the same fibrillar substance in the subepithelial area. The co-localization of cochlin and type II collagen in the fibrillar substance in the subepithelial area indicate that cochlin may play a role in the structural homeostasis of the vestibule acting in concert with the fibrillar type II collagen bundles.

The effect of ventilation tube insertion or trans-tympanic silicone plug insertion on a patulous Eustachian tube

Abstract Conclusions This study suggests that long-term ventilation tube insertion is the first-choice surgical treatment for a ‘sniff-type’ patulous Eustachian tube (PET). When treating a refractory PET, it is important to determine whether the patient had a habitual sniff. Objectives PET patients were divided into two groups: patients with a habitual sniff (sniff-type PET) and those without a habitual sniff (non-sniff-type PET). This study examined the effects of ventilation tube insertion or silicone plug insertion in each group. Methods Surgical procedures such as ventilation tube insertion or trans-tympanic silicone plug insertion were performed for these patients. Tubotympanoaero-dynamic graphy (TTAG) was also performed to determine the mechanisms underlying these treatments. Results There were 11 cases (17 ears) of sniff-type PET and 20 cases (27 ears) of non-sniff-type PET. An improvement in symptoms was found in 72.7% of the patients who underwent silicone plug insertion (66.7% for sniff-type PET and 74.1% for non-sniff-type PET) and in 90.9% of the patients who underwent ventilation tube insertion for sniff-type PET. In TTAG assessments, many sniff-type PET patients showed significant synchronous changes at high levels of pressure (over 40 daPa) in the external auditory meatus and nasopharynx when performing a slight Valsalva manoeuvre (below 200 daPa).

Hair roots as an mRNA source for mutation analysis of Usher syndrome-causing genes

mRNA is an important tool to study the effects of particular mutations on the mode of splicing and transcripts. However, it is often difficult to isolate mRNA because the organ or tissue in which the gene is expressed cannot be sampled. We previously identified two probable splicing mutations (c.6485+5G>A and c.8559-2A>G) during the mutation analysis of USH2A in Japanese Usher syndrome (USH) type 2 patients, but we could not observe their effects on splicing because the gene is expressed in only a few tissues/organs, and is not expressed in peripheral lymphocytes. In this study, we used hair roots as a source of mRNA of USH-causing genes, and successfully detected the expression of seven, except USH1C and CLRN1, of the nine USH-causing genes. We used RNA extracted from the hair roots of a patient who has both c.6485+5G>A and c.8559-2A>G mutations in USH2A in a compound heterozygous state to observe the effects of these mutations on transcripts. Reverse-transcription PCR analysis revealed that c.6485+5G>A and c.8559-2A>G inactivated splice donor and splice acceptor sites, respectively, and caused skipping of exons. Thus, RNA extracted from hair roots is a potential powerful and convenient tool for the mutation analysis of USH-causing genes.

Abnormal Expressions of DNA Glycosylase Genes NEIL1, NEIL2, and NEIL3 Are Associated with Somatic Mutation Loads in Human Cancer

The effects of abnormalities in the DNA glycosylases NEIL1, NEIL2, and NEIL3 on human cancer have not been fully elucidated. In this paper, we found that the median somatic total mutation loads and the median somatic single nucleotide mutation loads exhibited significant inverse correlations with the median NEIL1 and NEIL2 expression levels and a significant positive correlation with the median NEIL3 expression level using data for 13 cancer types from the Cancer Genome Atlas (TCGA) database. A subset of the cancer types exhibited reduced NEIL1 and NEIL2 expressions and elevated NEIL3 expression, and such abnormal expressions of NEIL1, NEIL2, and NEIL3 were also significantly associated with the mutation loads in cancer. As a mechanism underlying the reduced expression of NEIL1 in cancer, the epigenetic silencing of NEIL1 through promoter hypermethylation was found. Finally, we investigated the reason why an elevated NEIL3 expression level was associated with an increased number of somatic mutations in cancer and found that NEIL3 expression was positively correlated with the expression of APOBEC3B, a potent inducer of mutations, in diverse cancers. These results suggested that the abnormal expressions of NEIL1, NEIL2, and NEIL3 are involved in cancer through their association with the somatic mutation load.

Hyperbaric Oxygen Therapy as Adjuvant Treatment for Idiopathic Sudden Sensorineural Hearing Loss after Failure of Systemic Steroids

We evaluated the outcomes of and prognostic factors for idiopathic sudden sensorineural hearing loss (ISSNHL) treated with adjuvant hyperbaric oxygen therapy (HBOT). A retrospective review of clinical data was performed for 167 patients with ISSNHL who failed to respond to systemic steroids and were treated by adjuvant HBOT at Shizuoka Saiseikai General Hospital. We analysed the clinical outcomes, the averaged 5-frequency hearing level after systemic steroids, patient age, the interval between post-steroids and pre-HBOT, vertigo as a complication, the presence of diabetes mellitus, smoking history, and hypertension. Overall, after HBOT, complete recovery occurred in 16 (9.6%) of the patients, with definite improvement in 16 (9.6%) and slight improvement in 45 (26.9%). The overall rate of hearing improvement was higher in the study group (77/167 cases, 46.1%) than in the control group (52/160 cases, 32.5%; p = 0.021). If performed appropriately, HBOT should be able to improve hearing in many cases unresponsive to initial therapy.

Prognostic factors for idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy and intravenous steroids.

OBJECTIVEnThis study evaluated the prognosis of idiopathic sudden sensorineural hearing loss when treated with hyperbaric oxygen therapy and intravenous steroids.nnnMETHODSnThe clinical data for 334 patients with idiopathic sudden sensorineural hearing loss treated by hyperbaric oxygen therapy and intravenous steroids at our hospital were retrospectively reviewed. These data included the initial averaged five-frequency hearing level, patient age, interval between onset of symptoms and treatment, vertigo as a complication, and co-existence of diabetes mellitus.nnnRESULTSnThe overall improvement rate was 69.2 per cent, including better improvement (25.5 per cent), good improvement (21.0 per cent) and fair improvement (22.7 per cent).nnnCONCLUSIONnHyperbaric oxygen therapy appears to confer a significant additional therapeutic benefit when used in combination with steroid therapy for idiopathic sudden sensorineural hearing loss. If performed early, hyperbaric oxygen therapy may bring about hearing improvement in many patients who are unresponsive to initial therapy.