Goro Takahashi

Expansion and characterization of cancer stem-like cells in squamous cell carcinoma of the head and neck.

Evidence has accumulated indicating that only a minority of cancer cells with stem cell properties, cancer stem cells (CSCs), are responsible for maintenance and growth of the tumor. CD44 is currently used to identify CSCs as one of the cell surface markers for solid tumors. Here we report the identification, expansion, and characterization of CD44+ cancer stem-like cells from a permanent squamous cell carcinoma of the head and neck (SCCHN) cell line. Under serum-free medium culture conditions, a small population (less than 3%) of CD44+ cells in a permanent cancer cell line was dramatically increased up to around 40%. The CD44+ cell population also showed higher expression of CD133 and ABCG2 as compared with the CD44- cell population. Moreover, CD44+ cells possess not only a marked capacity for forming tumor spheres, proliferation, migration, and invasion in vitro, but also resistance to chemotherapeutic agents. Four genes related to chemoresistance, ABCB1, ABCG2, CYP2C8, and TERT, were up-regulated in a CD44+ cell population. Our findings indicate that a subpopulation of CSCs is maintained in the SCCHN cell line, and the presence of such CSCs has an important clinical implication for head and neck cancer treatment. Further characterization of CSCs may provide new insights for novel therapeutic targets and prognostic markers.

Resistance to apoptosis-inducing stimuli in CD44+ head and neck squamous cell carcinoma cells.

CD44 was identified previously as a surface marker in cancer stem cells (CSCs) of head and neck squamous cell carcinoma (HNSCC). Most cancer treatments have been linked to the activation of the apoptosis‐signaling pathway; however, the resistance mechanisms to apoptosis in CSCs have not yet been fully elucidated.

Immunoregulatory properties of CD44+ cancer stem-like cells in squamous cell carcinoma of the head and neck.

CD44 was found as a surface marker in cancer stem cell (CSC) of squamous cell carcinoma of the head and neck (SCCHN); however, the immunologic properties of such CSCs have not yet been elucidated.

Usefulness of Intraoperative Monitoring of Visual Evoked Potentials in Transsphenoidal Surgery

Postoperative visual outcome is a major concern in transsphenoidal surgery (TSS). Intraoperative visual evoked potential (VEP) monitoring has been reported to have little usefulness in predicting postoperative visual outcome. To re-evaluate its usefulness, we adapted a high-power light-stimulating device with electroretinography (ERG) to ascertain retinal light stimulation. Intraoperative VEP monitoring was conducted in TSSs in 33 consecutive patients with sellar and parasellar tumors under total venous anesthesia. The detectability rates of N75, P100, and N135 were 94.0%, 85.0%, and 79.0%, respectively. The mean latencies and amplitudes of N75, P100, and N135 were 76.8 ± 6.4 msec and 4.6 ± 1.8 μV, 98.0 ± 8.6 msec and 5.0 ± 3.4 μV, and 122.1 ± 16.3 msec and 5.7 ± 2.8 μV, respectively. The amplitude was defined as the voltage difference from N75 to P100 or P100 to N135. The criterion for amplitude changes was defined as a > 50% increase or 50% decrease in amplitude compared to the control level. The surgeon was immediately alerted when the VEP changed beyond these thresholds, and the surgical manipulations were stopped until the VEP recovered. Among the 28 cases with evaluable VEP recordings, the VEP amplitudes were stable in 23 cases and transiently decreased in 4 cases. In these 4 cases, no postoperative vision deterioration was observed. One patient, whose VEP amplitude decreased without subsequent recovery, developed vision deterioration. Intraoperative VEP monitoring with ERG to ascertain retinal light stimulation by the new stimulus device was reliable and feasible in preserving visual function in patients undergoing TSS.

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).

Surgical approach for treatment of carcinoma of the anterior wall of the external auditory canal.

Objective Treatment outcomes for carcinomas of the external auditory canal (EAC) were evaluated regarding radiologic and pathologic factors. Study Design Retrospective case review. Setting University hospital. Patients Fifteen patients histologically diagnosed with carcinomas of the EAC. Intervention A radiologic and pathologic analysis was performed on these patients histologically diagnosed with carcinomas of the EAC and treated surgically at our institution. We evaluated the size of focal defects in the anteroinferior (AI) canal wall of the tympanic bone with preoperative computed tomographic (CT) scans. Histopathologic slides for the same patients were evaluated according to the same criteria as the CT scans. Main Outcome Measure Pathologic features and estimated survival rate. Results Preoperative CT scans of 15 temporal bones demonstrated an AI canal wall defect ranging from less than 1 mm to full-thickness destruction. Six of 15 patients had an AI canal wall defect greater than 2 mm on preoperative CT scan. Pathologic findings in these 6 cases showed extension of the tumor through the AI defect into the anterior soft tissues. Information on patients’ survival status was obtained after a median follow-up period of 78.3 months (range, 18–151 mo). Conclusion Preoperative CT can be used to accurately determine the pathologic extent of tumor invasion in carcinomas of the EAC. This diagnostic method facilitates exchange of accurate clinical data in a comparable form and can be used to evaluate the efficacy of existing and proposed treatments for EAC tumors.

CD4+ T cell responses to HLA-DP5-restricted wild-type sequence p53 peptides in patients with head and neck cancer.

Wild-type sequence (wt) p53 peptides are attractive candidates for broadly applicable cancer vaccines. Evidence has been accumulating which indicates that CD4+ Th cells have an important role in generating and maintaining antitumor immune responses. To elucidate the nature of CD4+ Th responses to wt p53 epitopes in patients with squamous cell carcinoma of the head and neck (SCCHN), peripheral blood mononuclear cells (PBMCs) from HLA-DP5+ patients were stimulated with HLA-DP5-restricted wt p53 peptides, p53108–122 or p53153–166, and tested for the release of IFN-γ and IL-5 in ELISPOT assays. Immunohistochemistry for p53 accumulation in tumors, and ELISA for serum antibodies to p53 were also performed. Eleven (57.9%) of 19 HLA-DP5+ patients but none of 5 healthy donors had detectable Th1 and/or Th2 responses to wt p53 peptides by ELISPOT assay. Among these 11 responding patients, 9 (81.8%) and all 11 (100%) patients had a tumor burden and p53 accumulation, respectively. On the other hand, two responding patients were in post-operative condition. Interestingly, among nine patients with a tumor burden, four patients with early disease showed either Th1-polarized or mixed Th1/Th2 responses, while five patients with advanced disease showed either Th2-polarized or mixed Th1/Th2 responses. Our results suggest that wt p53108–122 and p53153–166 peptides stimulate both Th1- and Th2-type CD4+ T cell responses in patients with SCCHN, and anti-p53 Th responses may persist even after surgical resection of the tumor; however, the presence of a tumor and its progression may affect the nature of immune responses to wt p53 peptides.

Analysis of Helper T Cell Responses to Cry j 1-Derived Peptides in Patients with Nasal Allergy: Candidate for Peptide-Based Immunotherapy of Japanese Cedar Pollinosis

BACKGROUND Allergen specific immunotherapy is highly effective, but adverse events may occur during treatment. Peptide-based immunotherapy has been proposed as one of new strategies for reduction of allergic adverse reactions. We examined the possibility of candidate peptides for the development of peptide-based immunotherapy for Japanese cedar pollinosis. METHODS Twelve Cry j 1-specific T-cell lines were established from peripheral blood mononuclear cells (PBMC) of 12 patients with Japanese cedar pollinosis. Using these T-cell lines, 37 Cry j 1-derived overlapping peptides were assessed for their proliferative responses and cytokine production. RESULTS Four peptides corresponding to the Cry j 1 sequence were able to induce proliferative responses to more than one T-cell line: p61-80 (3/12; 25.0%); p115-132 (2/12; 16.6%); p206-225 (4/12; 33.3%); and p337-353 (5/12; 41.7%). Furthermore, T-cell lines generated from 11 of 12 donors (91.7%) responded to at least one of these four peptides. On the other hand, the pattern of cytokine production from Cry j 1-specific T-cell lines varied. Moreover, cytokine production patterns by stimulation with Cry j 1 peptide did not reflect those by stimulation with Cry j 1 protein. CONCLUSIONS Our results suggest four Cry j 1-derived peptides (p61-80, p115-132, p206-225 and p337-353) may be considered to be the immunodominant T-cell epitopes of the Cry j 1 molecule, and can be useful for the design of peptide-based immunotherapy for the management of Japanese cedar pollinosis.

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.

A Randomized Control Trail of Stepwise Treatment with Fluticasone Propionate Nasal Spray and Fexofenadine Hydrochloride Tablet for Seasonal Allergic Rhinitis

BACKGROUND In Japan, oral antihistamines are frequently used as the initial treatment for seasonal allergic rhinitis (SAR), and intranasal steroids are added when nasal symptoms worsen. This study aimed to evaluate whether starting treatment with fluticasone propionate nasal spray (FP) from the beginning of pollinosis symptoms and adding fexofenadine hydrochloride tablet (FEX) when SAR is aggravated could achieve improved amelioration of nasal symptoms throughout the pollen season in comparison with a treatment that involves starting with FEX and later adding FP. METHODS In this pragmatic, randomized, open-label, parallel-group trial, 51 Japanese cedar pollinosis patients (age, 16-85 years) were randomly divided and administered FP 100 mcg twice daily as an initial drug with FEX 60 mg twice daily as an additional drug and the same treatment in the reverse order. Nasal symptoms were evaluated in a daily dairy using a 4-point scale. The primary outcome was area under curve of the line representing the daily total nasal symptom score in the pollen season on a graph. RESULTS Initial treatment with FP was significantly (P = 0.0015) more effective than initial treatment with FEX in improving the primary outcome. The average daily total nasal symptom score in the initial treatment with FP group was better than that in the initial treatment with FEX group throughout the pollen season. CONCLUSIONS Initiating treatment with FP and adding FEX might lead to improved outcomes for nasal symptoms in comparison with the same drugs administered in the reverse order.