Biomedical subjects

Naoyuki Kohno

Publications and source records attributed to Naoyuki Kohno.

16 recordsLinked to original sources

PubMed2005

A solid-phase immunoassay of protease-resistant prion protein with filtration blotting involving sodium dodecyl sulfate.

The precise diagnosis for bovine spongiform encephalopathy (BSE) is crucial for preventing new transmission to humans. Several testing procedures are reported for determining protease-resistant prion protein in various tissues as a major hallmark of prion diseases such as BSE, scrapie, and Creutzfeldt-Jakob disease. However, contamination of materials from tissues or degradation of the specimens sometimes disturbs the accuracy of the assay. Here, we have developed a novel method for solid-phase immunoassay of the disease-specific conformational isoform, PrP(Sc), using filtration blotting of protein in the presence of sodium dodecyl sulfate (SDS) followed by a filtration-based immunoassay with a single anti-prion protein antibody, together with the improved fractionation procedure involving high concentrations of surfactant/detergent. The SDS/heat treatment renders unfolded PrP(Sc) quantitative retention on a polyvinylidene difluoride filter and allows enhancement of the analyte signal with immunodetection; thus, all of the tested specimens are determined with 100% accuracy. In addition, the immunoassay is completed in approximately 1h, indicating its usefulness not only for the screening of BSE specimens but probably also for the postmortem BSE diagnosis of fallen stock as the antibody recognizes the core part of PrP(Sc). The solid-phase immunoassay method, including the filtration blotting with SDS, would be applicable to determining even more sensitively proteins other than PrP(Sc), especially those having rigid conformations.

Animals↗

PubMed2005

Clinicopathologic study of non-Hodgkin lymphoma in sinonasal and hard palate regions in 15 Japanese cases.

Non-Hodgkin lymphomas of the sinonasal region have been the subject of numerous studies. Previous reports have suggested that nasal lymphomas occurring in Orientals are mostly of the natural killer cell (NK)/T-cell phenotype which contrasts with the preponderance of the B-cell type in western populations. Recent studies indicated that NK/T-cell lymphoma constitutes the clinical condition of lethal midline granuloma. These reports led us to question whether all NK/T lymphomas are always lethal midline granuloma. We have investigated a series of 15 cases of non-Hodgkin lymphomas in the nasal and/or paranasal sinuses clinically, immunohistochemically and for the presence of Epstein-Barr virus (EBV). This study showed that the presence of EBV was common in nasal NK/T lymphoma, and this type of lymphoma was clearly highly frequent in other types of nasal lymphoma in our department. Moreover, in 4 cases of NK/T-cell lymphomas, the clinical features of lethal midline granuloma did not appear, indicating that NK/T lymphomas are not always lethal midline granuloma.

Adult↗

PubMed2005

[Identification of sentinel lymph node in neck-node-negative oral and pharyngeal carcinoma study of patients, it's feasibility, and problems].

We assessd the feasibility and problems associated with sentinel lymph node (SLN) study in 13 cases of oral and pharyngeal squamous cell carcinoma (SCC) that were neck-node-negative clinically. The primary sites were the tongue (n = 10), other sites in the oral cavity (n = 2), and the mesopharynx (n = 1). The day before surgery, tracer was injected into the submucosa around the tumor, and scintigraphic images were acquired 2 hours later. The SLN was identified intraoperatively with a handheld gamma probe, and neck dissection, including the SLNs, was performed. Radioactivity within the nodes was confirmed with a well type scintillation counter, and all resected lymph nodes were histologically examined for metastasis. The SLN was identified in every case. There were regional lymphnode metastases in 4 cases, and metastasis to the SLNs was present in all of 4 cases. Thus, the SLN concept was valid for head and neck SCC, sentinel node navigation surgery (SNNS) was thought to be applied in stage NO SCC of the head and neck. If SNNS is performed, about 70% of patients do not require neck dissection. SNNS is feasible and cost-effective in these cases. We used two different tracers: phytate and tin colloid, and found that phytate was more useful. To avoid the effects of the shine-through phenomenon, it was thought that some directions of lymphoscintigram should be taken. For intraoperative identification of the SLNs, care should be taken to the angle of gamma probe. SLN study leads to clarify each patient's lymphoid flow mapping, and it is also useful to determine the dissection area of selective neck dissection.

Adult↗

PubMed2005

[The role of taxanes for head and neck cancer].

Taxanes are a highly active anti-cancer drug for squamous cell carcinoma of the head and neck (SCCHN). When used as a single agent, the overall response rates were between 20-40%. In Japan, the phase I study revealed that the maximum tolerated dose of the docetaxel was 70-90 mg/m2 and the recommended dose was 60 mg/m2. The main toxicity was neutropenia. Docetaxel administered in combination with cisplatin has demonstrated promising response rates ranging from 40-70% for recurrent or metastatic SCCHN. Its effect is similar to that of a cisplatin plus 5-fluorouracil regimen. A three-drug combination with docetaxel, cisplatin and 5-fluorouracil has been tested. The preliminary results with three drugs in combination seems superior to a two-drug combination. However, the final conclusions regarding theses drug combinations will be given by the results of an ongoing EORTC #249 71 study. Weekly docetaxel with concurrent chemoradiotherapy is feasible and active for locally unresectable SCCHN. Cisplatin plus 5-fluorouracil based concurrent chemoradiation regimens have demonstrated improved survival compared with conventional radiotherapy. Docetaxel including regimens showed efficacy with mucositis as the major acute toxicity and a swallowing problem as the chronic toxicity. Thus, the three-drug combination as the chemoradiation setting seems to be toxic for Japanese patients. A new intensive supporting care approach focused on mucositis is warranted.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2004

Phase I/II trial of weekly docetaxel and concomitant radiotherapy for squamous cell carcinoma of the head and neck.

BACKGROUND: A phase I/II trial of concurrent docetaxel and radiation for head and neck cancer was conducted to estimate the recommended dose schedule of docetaxel, and then to evaluate the therapeutic benefit. METHODS: Patients received radiation in 2.0-Gy single daily fractions to a total dose of 60 Gy. Docetaxel was administered weekly for 6 consecutive weeks. RESULTS: Docetaxel 15 mg/m(2) was considered the maximum tolerated dose (MTD). The recommended dose was decided as 10 mg/m(2). The phase II study was conducted using docetaxel at 10 mg/m(2). Thirty-nine patients were enrolled. The overall response rate was 96.9%. The prognosis of the complete response (CR) patients was significantly better than that of the partial response (PR) patients. Grade 3 or 4 adverse events consisted of lymphopenia, stomatitis, and anorexia. Thirty-two of the 35 eligible patients showed high compliance, of over 90%, and their toxicities were manageable. CONCLUSION: Even low-dose docetaxel shows a strong effect in combination with radiation, with a high survival rate in CR patients. The effect on survival will be assessed by further follow-up.A phase I/II trial of concurrent docetaxel and radiation for head and neck cancer was conducted to estimate the recommended dose schedule of docetaxel, and then to evaluate the therapeutic benefit.

Adult↗

PubMed2004

The role of chemotherapy for advanced oro and hypopharyngeal cancer.

Although important progress continuous to be made in the treatment of oro and hypopharyngeal cancer, the 5-year survival rate for all this disease has remained at less than 30% for the past 30 years. In the early 1980s, chemotherapy was introduced with high expectation of reducing in the incidence of distant metastases and increasing the possibility of local control. This article explores the use of chemotherapy in the treatment of advanced pharyngeal cancer. Thus, the efficacy of chemotherapy are reviewed and treatment options for advanced pharyngeal cancer are made. When advanced carcinoma is still localized, function-preserving surgery is performed. In these cases, the possibility of instituting adjuvant chemotherapy with an active treatment regimen may be taken into account depending on the condition of the patient and the tumor. Patients with surgically resectable tumors are given 1-2 cycles of induction chemotherapy. Cases who respond to the induction chemotherapy are subsequently given concurrent chemoradiotherapy. Residual lymph nodes in the neck are removed surgically. The cases who do not respond to the induction chemotherapy are treated with radical surgery. Patients with unresectable carcinoma are given concurrent chemoradiotherapy because local treatment should be performed in such patients as early as possible. In principle, concurrent regimens should be supplemented with adjuvant chemotherapy in all cases. This is particularly required for those with advanced N-stage patients.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2004

Electronic videoendoscopic laryngostroboscopy.

Color images obtained using electronic videoendoscopic laryngostroboscopy (EVLS) were presented and the utility of this technique for the diagnosis of dysphonia was discussed in this paper. Stroboscopic evaluations of laryngeal lesions were performed using a rhinolaryngeal electronic videoendoscope system employing a single-plate simultaneous color charge-coupled device (CCD) chip method. Twenty patients underwent electronic videoendoscopic laryngostroboscopy. A Karl Storz laryngostroboscope Pulsar was connected to this system and laryngeal lesions were assessed. The potentialities of laryngostroboscopy using this system were evaluated. Clear stroboscopic images were obtained in all patients. Multiple still images during vocal fold vibration were acquired using an optional function. The laryngostroboscope is not compatible with conventional systems employing a single-plate red, green, and blue (RGB) surface scanning method. However, the system used was successfully connected to a laryngostroboscope. EVLS appears to be a powerful new tool for the diagnosis of dysphonia.

Adult↗

PubMed2003

Feasibility and cost-effectiveness of sentinel lymph node radiolocalization in stage N0 head and neck cancer.

OBJECTIVES: To determine the feasibility of sentinal lymph node (SN) radiolocalization and to assess the cost-effectiveness of the SN navigation surgery strategy in patients with stage N0 squamous cell carcinoma (SCC) of the head and neck. Patients Eleven consecutive patients with stage N0 SCC of the head and neck. METHODS: Head and neck lymphoscintigraphy was performed 2 hours after the injection of technetium Tc 99m tin colloid or phytate. A handheld gamma probe was used to detect the SN before and directly after making a skin incision. Nodes were evaluated histopathologically for micrometastasis. To determine the expected cost savings, a decision tree sensitivity analysis was designed based on the 2 competing strategies: ipsilateral neck dissection vs SN navigation surgery. The costs referred to billed costs based on the Japanese national insurance reimbursement system. RESULTS: The sensitivity of SN navigation surgery in our series was 100% (11/11) on a patient-by-patient basis and 94% (17/18) on a node-by-node basis. Micrometastasis was found in 36% (4/11). Assuming the micrometastasis prevalence, sensitivity, and specificity of navigation surgery for detecting SN to be 30%, 90%, and 100%, respectively, the decision tree sensitivity analysis showed that introduction of SN navigation surgery in place of ipsilateral neck dissection would yield cost savings of $1218 (US) per stage N0 patient in Japan and avoid 7 surgical deaths per 1000 patients who are supposed to undergo neck dissection in the neck dissection strategy. Break-even point analysis for the SN navigation surgery strategy showed that the threshold value required more than 41 patients for the savings to begin to accrue. CONCLUSION: Our results indicate that SN navigation surgery using radiolocalization is feasible and cost-effective, based on decision tree sensitivity analysis, in patients with stage N0 SCC of the head and neck.

Adult↗

PubMed2003

Voice quality after laser surgery or radiotherapy for T1a glottic carcinoma.

OBJECTIVE: To compare the effect on phonation of radiotherapy and endoscopic laser surgery for stage T1a glottic squamous cell carcinoma. STUDY DESIGN: Retrospective. METHODS: Patients treated for stage T1a glottic carcinoma from August 1994 to March 2000 and who had been followed for at least 1 year were candidates. Eight patients who underwent radiotherapy and 22 who underwent laser surgery were enrolled. Indirect laryngoscopy and stroboscopic examination were performed, and voice quality was analyzed using standard parameters. RESULTS: Maximum phonation time, average airflow rate, sound pressure level, and average fundamental frequency during unconditional phonation were similar after laser surgery and radiotherapy. However, compared with normal men who were 50 years of age or older, the average fundamental frequency was higher after laser surgery. CONCLUSIONS: Contrary to some reports, the voice quality is minimally affected by laser surgery for T1a glottic carcinoma, and outcome is similar to radiotherapy. The average fundamental frequency is higher than normal after laser surgery, but the effect on the quality of life was trivial.

Aged↗

PubMed2002

New visualization technique with a three-dimensional video-assisted stereoendoscopic system: application of the BVHIS display method during endolaryngeal surgery.

A three-dimensional video-assisted stereoendoscopic system (3D video system) developed by the Shinko Optical Company, Ltd. (Tokyo, Japan), and referred to as the binocular vision by horizontal image shifting display method (BVHIS display method), has been developed to digitally process ordinary video signals obtained with a video camera connected to a direct videolaryngoscope. The three-dimensional video system provides the surgeon with stereoendoscopic video images and enhances the ability of the surgeon to perform delicate endoscopic procedures. The three-dimensional video-assisted stereoendoscopic laryngosurgical procedure and its underlying principles are described in this paper. A total of 12 patients with laryngeal lesions causing dysphonia underwent three-dimensional video-assisted stereoendoscopic laryngosurgery. Although the video image obtained with the BVHIS display method is only pseudo-three-dimensional, this method enables the surgeon to perceive both depth perception and realism. We describe a surgical procedure using this new visualizing technique and the underlying principles of the technique. Preoperative and postoperative evaluations of the patients' vocal functions are also described. This system is a useful tool for the treatment of laryngeal lesions causing dysphonia.

Adult↗

PubMed2002

The transfrontal approach using nasal endoscopy to treat anterior skull base carcinomas.

We used a simple subcranial procedure that employed nasal endoscopy to resect two anterior skull base tumors. The solid geometry of the deep frontal sinus must be known to determine the appropriateness of this technique. Since 1999 two patients underwent this technique and have exhibited no signs of local or distant disease for 36 months and 32 months, respectively. This approach minimizes visible scarring, provides a wide exposure of the roof of the anterior ethmoid, and reduces the risks of excessive bleeding and neurogenic complications. The patients recovered rapidly so the treatment was cost-effective and the patients achieved an early return to work. We conclude that the transfrontal approach for anterior skull base tumors can be simple and effective. Further studies of this minimally invasive maneuver for high-risk patients are warranted.

Case Reports↗

PubMed2002

Intralaryngeal application of a miniaturized ultrasonic probe.

We developed a method for performing intralaryngeal ultrasonography. Normal larynges were obtained from 10 cadavers and examined using an intraluminal ultrasonic tomography apparatus connected to a radial scanning 20 MHz miniaturized probe. The larynx was placed in a bath filled with physiologic saline. and the probe was inserted through the forceps channel of the fiberscope (6 mm diameter). A horizontal ultrasonic image of the vocal fold was obtained. Histologic sections of the larynx were compared with the ultrasonic images. The mucosa in the membranous region of the vocal fold was comprised of three layers ultrasonographically. The epithelium and superficial layer of the lamina propria were visualized as a high echo (hyperechoic) region, the intermediate layer of the lamina propria was visualized as a low echo (hypoechoic) region and the deep layer of the lamina propria was seen as a hyperechoic region. The vocal fold structure can be visualized by intralaryngeal ultrasonography using the filling method. This method may be clinically useful for the detection of tumors involving the vocal folds.

Animals↗

PubMed2002

Use of freeze-dried autologous fascia to augment the vocal fold: an experimental study in dogs.

This study assessed the practicality of using autologous freeze-dried fascia to augment the vocal fold. Freeze-dried autologous fascia was injected into the vocal fold and skin of dogs in order to monitor sequential histological changes. Fascia lata was harvested from six adult dogs. After freeze-drying, minced fascia suspended in hyaluronic acid was injected subcutaneously into the abdominal wall and directly into the vocal fold. The specimens were extracted 3 weeks after injection and studied histologically. Freeze-drying destroyed all cellular components but did not affect the collagen fibers, which are the major components of fascia. There was no evidence of degeneration, necrosis or infection. Fibroblastic infiltration was seen in the fascia injected into the vocal fold, but the fascia remained as an unencapsulated mass at the site of injection. This study demonstrates that freeze-drying does not compromise the collagen in fascia and that the injection of freeze-dried collagen is well tolerated. Freeze-dried fascia is a promising new augmentation material.

Animals↗

PubMed2002

Digital image processing of laryngeal lesions by electronic videoendoscopy.

OBJECTIVES: To present electronic videoendoscopy of the larynx with digital image processing and to discuss this endoscopic technique from the standpoint of diagnostic usefulness of laryngeal lesions. STUDY DESIGN: Electronic videoendoscopic evaluation of laryngeal lesions with digital image processing. METHODS: Seventy patients underwent electronic videoendoscopy without digital image processing and, subsequently, with the digital image processing function. Of these, 15 patients with white lesion of the vocal fold and laryngeal neoplasms were assessed in the study. Clinical assessments made before enhancement of digital image processing function were compared with those after enhancement in 15 patients. RESULTS: Of the 15 patients observed, the clinical diagnoses of two patients were changed after enhancement. Both patients underwent endolaryngeal microsurgery with histopathological examination of the removed lesions, which confirmed the definitive diagnosis. The clinical diagnoses of both patients after enhancement were compatible with histopathological diagnoses. CONCLUSIONS: The enhanced color images provided by this system are superior in both quality and resolution to those obtained by conventional flexible fiberoptic endoscopy with a video camera. This system should be a valuable tool for the diagnosis of laryngeal lesions.

Aged↗

PubMed2002

Concurrent chemoradiotherapy with low-dose cisplatin plus 5-fluorouracil for the treatment of patients with unresectable head and neck cancer.

OBJECTIVE: The purpose of this study was to determine the efficacy of concurrent chemoradiotherapy using conventional radiotherapy combined with low-dose daily 5-fluorouracil (5FU) and cisplatin (CDDP) for the locally unresectable head and neck cancer patients. PATIENTS AND METHODS: From September 1996 through December 2000, we carried out a phase II study of concurrent chemoradiotherapy with low-dose CDDP plus 5FU for the treatment of patients with unresectable squamous cell carcinoma of the head and neck. Chemoradiotherapy consisted of irradiation with 1.6-2.0 Gy/day for 5 days per week up to a total dose 68 Gy and CDDP 3 mg/m2 by intravenous infusion over 1 h plus 5FU 150 mg/m2 by intravenous infusion over 24 h per day for 5 days per week. RESULTS: Ninety percent of the patients had stage IV disease, including 65% of patients with T4 disease. Thirty-three patients (83%) received the full treatment as planned; 39 (98%) received full-dose radiotherapy and 33 (83%) full-dose chemotherapy. Of the 40 patients evaluable for response, 20 (50%) achieved complete response (CR) and 12 (30%) partial response with an overall response rate of 80%. Among the 20 CR patients, 15 underwent endoscopic blind biopsies and 4 had positive lesions. The most frequently observed toxicity was mucositis. Ten patients developed grade III mucositis, and 3 patients required enteral nutritional support through a feeding tube. Grade III leukopenia, anemia and thrombocytopenia were observed in 28, 25 and 20% of the patients, respectively. The median duration of follow-up at the time of analysis was 18 months. The median survival time was 23 months. The responders survived longer (34 months) than the nonresponders (4 months; p < 0.05). CONCLUSION: This regimen is safe and efficacious in the treatment of patients with advanced unresectable head and neck cancer.

Adult↗

PubMedDate not supplied

Feasibility of sentinel lymph node radiolocalization in neck node-negative oral squamous cell carcinoma patients.

We examined the reliability of the use of lymphoscintigraphy (LS) and a hand-held gamma probe (GP) to identify the sentinel lymph node (SLN), and sequentially determined the feasibility of SLN radiolocalization in clinical neck node-negative oral squamous cell carcinoma (SCC) patients. A radiolabel with the unfiltered (99m)Tc tin colloid was injected submucosally around the primary site followed by LS at 2-hour intervals. Preoperative localization was performed with GP. After en bloc removal of the regional lymphatics, histopathologic results for the nodes were compared with the SLN radiolocalization. The LS and GP counts were well correlated, and there was concordance between SLN and neck node status in 7 of 8 cases (87.5%). We thus considered that our concept in this study was valid in determining the necessity for neck dissection for those node-negative oral SCC patients.

Adult↗