Biomedical subjects

J Kanzaki

Publications and source records attributed to J Kanzaki.

At least 37 records · Page 2Linked to original sources

PubMed2000

Morphological evidence that impaired intraneural microcirculation is a possible mechanism of eighth nerve conduction block in acoustic neuromas.

In an attempt to better understand the mechanism of eighth nerve dysfunction in acoustic neuromas (vestibular schwannomas), we have morphologically examined microvessels and nerve fibers in the intracanalicular portion of eighth nerve specimens attached to these tumors. At the light microscopic level, microvessels were well preserved in all the specimens, even in the extremely flattened or markedly small nerve fascicles. However, the density of microvessels was quite variable in the different specimens, presumably as the result of different levels of compression by the tumors and the subsequent formation of a collateral microcirculation in each nerve. Focal areas of mild endoneurial fibrosis were found in 9 out of 22 specimens examined, but severe and widespread degeneration or demyelination was not found in any of the specimens. Ultrastructural studies frequently revealed mild to moderate abnormalities in myelin sheaths, and occasionally showed endothelial hyperplasia and hypertrophy in all the specimens. These findings are consistent with the slight to moderate reduction of endoneurial blood flow in the eighth nerves. The resultant ischemic condition in the eighth nerve may account for the eighth nerve conduction block in acoustic neuromas.

Adult↗

PubMed2000

The long-term outcome of hearing preservation following vestibular schwannoma surgery.

OBJECTIVE: The aim of this study is to describe the long-term outcome of preserved hearing after vestibular schwannoma surgery. METHODS: Subjects are 20 unilateral vestibular schwannoma patients whose class A hearing of the AAO-HNS classification was preserved successfully after tumor removal. Hearing preservation surgery was attempted via the middle cranial fossa (MCF) or the extended MCF approach. The follow-up periods ranged from 2 to 16 years. The outcome measures included the pure tone average (PTA) and speech discrimination score (SDS). RESULTS: PTA was maintained in less than 30 dB in 11 out of 20 patients within 2 years follow-up, six out of 13 patients within 4 years follow-up, and two out of five patients within 6 years follow-up, respectively. SDS was maintained in more than 70% in 17 out of 20 patients within 2 years follow-up, ten out of 13 patients within 4 years follow-up, and three out of five patients within 6 years follow-up, respectively. CONCLUSIONS: The preserved hearing maintained about more than 40% of the patients with the class A hearing in every 2 years follow-up. From this result, we can conclude that the hearing preservation surgery could be one of the best treatments for vestibular schwannoma patients with class A hearing. However, further study will be needed to clarify the mechanism of the deterioration in hearing after hearing preservation surgery.

Adolescent↗

PubMed2000

A comparison and conversion table of 'the House-Brackmann facial nerve grading system' and 'the Yanagihara grading system'.

A comparison between the House-Brackmann facial nerve grading system (the HB-system) and the Yanagihara grading system (the Y-system) was studied with 199 evaluations of 62 cases of postoperative unilateral acoustic neuroma. In the beginning, an original draft of the conversion table was formulated according to the 199 evaluations, in which, 0-6, 8-14, 16-20, 22-28, 30-38, and 40 points in the Y-system were matched with grade VI, V, IV, III, II, and I in the HB-system respectively. The result of the present study for prediction of sequelae showed that it was not necessary to consider the sequelae in a conversion table. And more, the study of an inter-observer variation showed that the lower and upper limits of the scores in the Y-system may shift within about a 2-point range in the draft table. From these aspects, a newly revised conversion table was proposed as a revised conversion table, in which, 0-6, 8-14, 16-22, 24-30, 32-38, and 40 points in the Y-system were matched with grade VI, V, IV, III, II, and I in the HB-system. This revised conversion table is much easier to remember for clinical use, because the score of the lower limit of each grade is simply in multiples of 8, that is, 0, 8, 16, 24, 32 and 40.

Facial Nerve↗

PubMed2000

Clinical significance of expression of membrane type 1 matrix metalloproteinase and matrix metalloproteinase-2 in human head and neck squamous cell carcinoma.

Three different membrane-type matrix metalloproteinases (MT-MMPs) activate in vitro the latent form of matrix metalloproteinase-2 (MMP-2), which is one of the key proteinases in invasion and metastasis of various cancers. We examined the mRNA expression of MT1, 2, and 3-MMPs and MMP-2 in cell lines of head and neck squamous cell carcinoma (HNSCC) and quantitated the relative expression levels in human HNSCC tissues by Northern blotting. The tissue localization of MT1-MMP and MMP-2 was determined by immunohistochemistry and in situ hybridization. Their implications in clinicopathologic factors were statistically evaluated. All cell lines examined consistently expressed MT1-MMP and MMP-2, but not MT2, 3-MMP. In the clinical specimens, there was a significant correlation in coexpression of messenger of RNA (P = .0005) and colocalization by immunohistochemistry (P < .0001) for MT1-MMP and MMP-2. Relative mRNA expression levels of MT1-MMP and MMP-2 in the carcinoma tissues were significantly higher than those of the control tissues (P = .0045 and P = .0122, respectively). Both mRNA expression level and immunopositivity of MT1-MMP significantly correlated with lymph node metastasis (P = .0081 and P = .0193, respectively), which was confirmed by multivariate logistic regression analysis. Immunoreaction of MT1-MMP and its mRNA expression were observed in both carcinoma cells and stromal cells. The localization of MMP-2 closely corresponded to that of MT1-MMP. These observations suggest that MT1-MMP possesses a role as a determinant of lymph node metastasis in HNSCC, and that concurrent expression of MT1-MMP and MMP-2 are involved in progression of HNSCC.

Blotting, Northern↗

PubMed2000

Use of the ultrasonically activated scalpel in acoustic neuroma surgery: preliminary report.

Recently, the ultrasonic activated scalpel (the Harmonic Scalpel, HS) has been introduced in laparoscopic surgery. We have applied the HS in debulking the tumor in the posterior fossa and concluded that this is useful in acoustic neuroma surgery. Fifteen patients with a tumor extending more than 20 mm into the posterior fossa were included in this study. The extended middle cranial fossa approach type II was used in 13 patients and type III (hearing preservation surgery) was used in 2 patients. In one of two patients, hearing was preserved. Postroperative facial nerve function according to the House-Brackmann method was grade I in 12 patients, grade II in 2 patients, and grade III in 1 patient. Compating the technique of using HS to a pair of bipolar forceps and/or ultrasonic cavitational aspirator, the former can result in better preservation of the facial nerve function.

Journal Article↗

PubMed2000

Medial (intra-cisternal) acoustic neuromas.

The clinical characteristics of "medial" or "intra-cisternal" acoustic neuroma (AN) treated in our institute were reviewed. Among 466 patients with ANs in our series during the last 20 years, 6 patients (1.3%) were considered to fill the criteria of medial AN definition. Compared with those with non-medial ANs, the patients with medial ANs show a tendency to have cerebellar and/or cranial nerve dysfunction (especially trigeminal and/or facial nerves) in addition to hearing loss at the time of initial presentation. On magnetic resonance imaging, medial AN is visualized as a multi-cystic mass lesion in the cerebello-pontine cistern without extension into the internal auditory canal in most cases. Although total removal of tumor was achieved in all cases, the results of preservation of facial nerve function were not satisfactory. Medial AN can be considered as a clinical, but not pathological, subtype in terms of the functional outcomes of the facial nerve and hearing.

Facial Nerve↗

PubMed2000

Clinicopathological significance of expression of CD44 variants in head and neck squamous cell carcinoma.

Splice variants of the cell surface glycoprotein CD44 have been reported to be associated with the progression of various human tumors. The aim of this study is to determine the correlation between the expression of CD44 isoforms, especially CD44 variant 2 (CD44v2), and the clinicopathological features of head and neck squamous cell carcinomas (HNSCCs). The expression of CD44 isoforms was evaluated immunohistochemically in paraffin-embedded tissues from 89 primary lesions, using monoclonal antibodies against CD44 standard (CD44st), CD44 variant 6 (CD44v6) and CD44v2. Cancer tissues from 89 (100%), 85 (95.5%) and 59 (66.3%) patients showed positive immunoreactivity for CD44st, CD44v6 and CD44v2, respectively. A significant correlation was observed between the down-regulation of CD44v2 and poorer differentiation of the tumor cells (P = 0.02). We could not find any significant correlation between the expression of CD44v2 and T stage or N stage (lymph node status). However, the rate of positive cervical lymph node metastasis tended to increase with reduced expression of CD44v2 (P = 0.08). Down-regulation of CD44v2 expression was correlated with shorter overall survival (P = 0.01). Furthermore, Cox's multivariate analysis revealed that only CD44v2 expression and lymph node status were independent prognostic factors. These findings suggest that down-regulation of CD44v2 expression may be one of the biological markers for the degree of malignancy in HNSCCs.

Adult↗

PubMed2000

Vestibular schwannoma presenting as sudden deafness.

In this study, we analysed the clinical and audiological features of 24 vestibular schwannoma patients presenting with sudden deafness who visited our hospital within 10 days after its onset. The relationships between the prognosis of hearing loss and the clinical and audiological features including the pure-tone average (PTA), the presence of dizziness and/or vertigo, the tumour size and the auditory brain stem response (ABR) findings were evaluated. Hearing recovery depended on the PTA and tumour size, but even a small tumour induced sudden deafness. Impaired hearing completely recovered in five our of 24 patients. ABR findings indicated that the aetiology of sudden deafness in the vestibular schwannoma patients might vary in each patient.

Adult↗

PubMed1999

Does hearing preservation surgery for acoustic neuromas affect tinnitus?

Questionnaires returned from 202 patients who had undergone acoustic neuroma resection were analyzed with special reference to the effect on tinnitus of surgery that attempted to preserve hearing versus surgery that did not. We also examined the relationship between postoperative hearing and tinnitus following surgery to preserve hearing (103 patients, HP group). The incidence of preoperative tinnitus in the HP group was 78.6%; postoperatively it increased to 89.3% (p = 0.0367). The remaining 99 patients (non-HP) underwent labyrinthectomy during tumor resection. In this group tinnitus occurred in 72.7% preoperatively and in 67.3% postoperatively (p = 0.4097). Our findings show that when tinnitus was absent preoperatively, 85% of the HP group developed it postoperatively compared to 31% of patients in the non-HP group. The outcome of surgery to preserve hearing had no bearing on the loudness or annoyance of postoperative tinnitus. Although postoperative tinnitus is tolerable to most patients, they must be informed prior to surgery about its possible occurrence or worsening, especially if the goal is to preserve hearing.

Journal Article↗

PubMed1999

[Statistical analysis of localized non-Hodgkin's lymphomas of the head and neck--multivariate analysis of prognostic factors and evaluation of therapeutic modalities].

Prognostic factors and treatment outcome of 48 patients with Stage I (29) or II (19) non-Hodgkin's lymphoma of the head and neck were analyzed retrospectively. There were 26 males and 22 females, aged from 15 to 89 years old, with an average age of 57. The primary lesion was located in Waldeyer's ring in 25 patients, the nasal cavity and paranasal sinuses in 13, cervical lymph nodes in 8, and others in 2. Histologically, 2 had low grade lymphoma, 42 had intermediate grade disease, and 1 had high grade disease. The patients were treated with radiation alone (5 patients), chemotherapy according to a cyclophosphamide, doxorubicin, vincristine, prednisone- (CHOP) regimen (8 patients), or a combination of both treatments (35 patients). In univariate analyses, an unfavorable prognosis was associated with age > or = 60, Stage I disease, and extralymphatic lesion. Multivariate analysis showed that an extralymphatic lesion was a significant independent risk factor for death (p = 0.0093). The overall five-year survival rate was 73.5%. Differences in the treatment was not reflected in the outcome. Our results suggest that a combination of chemotherapy (CHOP) and radiation is an appropriate treatment for lymphatic stage I and II non-Hodgkin's lymphoma of the head and neck. However, more intensive therapy is necessary for patients with extralymphatic head and neck NHL.

Adolescent↗

PubMed1999

[Late phase II clinical study of RP56976 (docetaxel) in patients with advanced/recurrent head and neck cancer].

A late phase II clinical study of RP56976 (docetaxel), a new anticancer agent for advanced/recurrent head and neck cancer, was conducted in 29 institutions all over Japan as a multi-institutional cooperative study. Docetaxel was administered by 1 to 2-hour intravenous infusion at a dose of 60 mg/m2 every 3 to 4 weeks. Of 63 patients eligible in this study, 59 were judged as complete cases. Complete response (CR) was observed in 1 patient, partial response (PR) in 13, no change (NC) in 25, and progressive disease (PD) in 20, for an overall response rate of 22.2% (14/63, 95% CI: 12.7-34.5%) in eligible cases, and 23.7% (14/59, 95% CI: 13.6-36.6%) in complete cases. Previously treated patients showed a 17.9% (10/56) response rate, whereas treatment--naive patients showed a 57.1% (4/7) response rate. Among 46 patients who received prior chemotherapy, one CR and 7 PR were observed with a 17.4% response rate. Major hematological toxicities were leucopenia in 95.1% (> or = grade 3, 59.7%) and neutropenia in 90.3% (> or = grade 3, 79.0%). Other severe toxicities (> or = grade 3) included anorexia in 9.7% (6 cases), diarrhea in 3.2% (2 cases), dyspnea in 3.2% (2 cases), and fatigue in 3.2% (2 cases). One patient had a grade 3 interstitial pneumonia; however, symptoms were resolved by the administration of corticosteroids. During this study, one patient died due to multiple organ failure (MOF) caused by disseminated intravascular coagulation (DIC), and this case was reported as a therapy-related death. Based on these results, docetaxel is an active agent for treatment of head and neck cancer.

Adenocarcinoma↗

PubMed1998

Hearing in the MRL/lpr mouse as a possible model of immune-mediated sensorineural hearing loss.

In order to clarify the possible mechanism of hearing loss in immune-mediated sensorineural hearing loss, basic research needed includes animal model studies. In the present investigation, we examined hearing thresholds and cochlear histologies of the MRL/lpr mouse which is now well-known as a model for pathology consistent with systemic lupus erythematosis (SLE). Present findings demonstrated that there were no statistically significant differences in auditory brainstem response (ABR) thresholds between 4- to 6-week-old "young" and 20- to 25-week-old "old" MRL mice. These differences were not sex-dependent. Under light microscopy, there were no abnormal morphological findings in the cochleas of either young or old MRL mice. With immunohistochemistry, mouse IgG was detected around the capillary walls in the stria vascularis in both young and old MRL mice. Serum IgG level of the MRL mice significantly decreased after predonisolone (PSL) administration. However, expression of mouse IgG in the stria vascularis was not observed in the MRL mice after PSL administration. From these results, we speculate that the hearing of the MRL mouse does not always deteriorate, and the deposition of mouse IgG on the capillary wall in the stria vascularis is not a sufficient factor to induce hearing loss. At this point, we conclude that the MRL mouse should not be considered a useful model for immune-mediated sensorineural hearing loss.

Aging↗

PubMed1998

Age-related changes in transiently evoked otoacoustic emissions and distortion product otoacoustic emissions in normal-hearing ears.

Age-related changes in transiently evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) were evaluated in normal-hearing ears. The TEOAE was elicited by a non-linear click with a stimulus level of 82 +/- 1 dB SPL using ILO 88 in 251 normal-hearing ears. The DPOAE at the frequency of 2f1-f2 was measured with stimulus levels of 70 dB SPL (f1) and 60 dB SPL (f2) and with an f2/f1 ratio of 1.2 using ILO 92 in 64 normal-hearing ears. The results obtained showed that TEOAE and DPOAE were decreased with increasing age. Moreover, the same pattern of gradual decrease in TEOAE and in DPOAE suggests the possibility of the same generating mechanism associated with outer hair cells (OHCs).

Acoustic Stimulation↗

PubMed1998

Acinic cell carcinoma of maxillary sinus.

Acinic cell carcinoma is a tumor that occurs most commonly in the parotid glands. We have experienced a rare case of acinic cell carcinoma of the left maxillary sinus. The patient was a 71-year-old female. She noticed her left nasal congestion and epiphora from left eye in April 1994. She had a history of left maxillary sinus surgery in February, 1972. Antrotomy was performed and histopathological examination of specimen from the maxillary sinus proved acinic cell carcinoma. The tumor was considered to be the recurrence 22 years after initial surgery, because it coincided with the surgical specimen of previous surgery. Radical resection of maxilla was performed for complete resection of tumor with palate reconstruction by left scapula and latissimus dorsi myocutaneous flap. No recurrence is observed for more than 4 years after surgery. Although this tumor is of low grade malignancy, complete resection with adequate surgical margin is advisable due to high incidence of this tumor to recur after long periods of time.

Aged↗

PubMed1998

Lubrication mechanism of the larynx during phonation: an experiment in excised canine larynges.

To evaluate how the viscosity of the laryngeal mucus influences vocal fold vibration, two fluids of differing viscosity were applied separately to excised canine larynges and experimental phonation was induced. Vibration of the vocal folds was measured by use of a laryngostroboscope and an X-ray stroboscope. With the high viscosity fluid, the amplitude of vibration of the free edge and the peak glottal area was decreased while the open quotient was increased. Because the viscosity of this fluid affected the wave motion of the vocal fold mucosa, changes in viscosity of the mucus may be involved in causing such disorders as hoarseness, in the absence of apparent changes in the vocal folds themselves.

Animals↗

PubMed1998

[Result of treatment of squamous cell carcinoma of the tongue and floor of the mouth].

A statistical analysis was performed on 40 patients with squamous cell carcinoma of the tongue and mouth floor, which could be followed for 6 months or more after initial treatment in the Department of Otorhinolaryngology, School of Medicine, Keio University during the 14 years from 1983 to 1996. The 5-year survival rate determined by the Kaplan-Meier method for each stage was 100% for Stage I, 77.8% for Stage II, 60.0% for Stage III and 44.4% for Stage IV. Thirteen suffered a relapse after initial treatment and patients with relapses among them have all survived after the subsequent salvage surgery. In contrast, in nine patients with cervical relapse, however, the 5-year survival rate was 11.1% with an unfavorable prognosis. This confirmed that suppressing cervical relapses is important for treating tongue and floor mouth cancers. The treatment strategy in our department is characteristic of positive enforcement of prophylactic neck dissection in the surgery and introduction of neoadjuvant chemotherapy (NAC) in the chemotherapy. Prophylactic neck dissection was performed in the 17 patients and no relapse was observed on the side of prophylactic neck dissection. NAC was performed on 26 patients in consideration of suppressed minute metastases and preserved function and 24 determinable cases were statistically analyzed. Among patients who had received NAC, the oral function was successfully preserved without surgical intervention in six patients both patients who showed complete response (CR) and four out of 14 patients who had a partial response (PR) following NAC. This may indicate that the oral function could be preserved in those patients who exhibited CR following NAC, but that preservation could be difficult in patients who exhibited PR. In addition, concerning the accumulated 5-year survival rate in relation to the effect of NAC, responders (CR + PR) accounted for 90.9% and non-responders (no change + progressive disease following NAC) for 15.0% with a very good outcome noted in the responder group. These figures suggest that responders may have a significantly good prognosis in the multivariant analysis including additional background factors before treatment as well. Accordingly, the present therapeutic measures for non-responders must be reexamined and performed more carefully and accurately as compared with those for responders.

Adult↗

PubMed1998

[Statistical analysis of oropharyngeal squamous cell carcinoma--multivariate analysis of prognostic factors and evaluation of therapeutic modalities].

Ninety-one cases of oropharyngeal squamous cell carcinoma initially treated at Keio University Hospital between July 1981 and June 1996 were reviewed retrospectively. There were 83 males and 8 females, aged from 29 to 83 years old, with an average age of 62.7. The primary lesion was located in the lateral wall in 52 patients (57.1%), the superior wall in 23 (25.3%), the anterior wall in 14 (15.4%) and the posterior wall in 2 (2.2%). Double cancer was detected in 21 patients (23.1%). The patients were divided into two groups according to the initial main treatment of the primary lesion without regard to chemotherapy: 72 patients (79.1%) who received curative radiotherapy with or without salvage surgery, and 14 patients (15.4%) who underwent curative surgery with or without preoperative and/or postoperative radiation. The remaining 5 patients were treated by chemotherapy alone. Prior to the above treatments 50 patients (54.9%) received neoadjuvant chemotherapy (NAC). Survival distributions were estimated by the Kaplan-Meier method as univariate analysis, and compared by the generalized Wilcoxon test. The overall five-year cumulative survival rate was 55.6%. The five-year survival rates according to stage (UICC classification, 1987) were as follows: stage I (11 cases), 70.7%; stage II (12 cases), 63. 6%; stage III (30 cases), 52.3%; and stage IV (38 cases), 52.5%. Significant clinicopathological variables that influenced survival were: (1) T stage (p = 0.0075); (2) age (p = 0.0274); and (3) location of primary lesion (p = 0.0400). The results of multivariate analysis by Cox's proportional hazards model identified T stage as a significant independent prognostic factor. Evaluation of the therapeutic modalities led to the following conclusions. (1) Differences in the initial treatments of the primary lesion were not reflected in the outcome. (2) Salvage surgery for residual or recurrent tumor contributed to improving the survival. The superior wall type, in particular, seemed to be a good indication for salvage surgery. (3) Although the limitations of radiotherapy are not defined clearly, we have to determine the indications for radical resection of tumors resistant to radiotherapy with reconstruction. (4) The response rate of NAC reached 85.4%, but there were no significant differences in survival between the group that underwent NAC and the other group in any other subset analyses. (5) Among the patients who underwent NAC, the responder (CR + PR) group showed a better five-year survival rate (61.3%) than the non-responder (NC + PD) group (42.9%), but the difference was not significant.

Adult↗

PubMed1998

[Combination chemotherapy with nedaplatin and 5-FU for head and neck cancer].

Nedaplatin (CDGP), which is a CDDP analog, is an effective anticancer agent for head and neck cancer. The first-line chemotherapy for head and neck cancer is reported to be the combination of CDDP and 5-FU. We undertook a clinical trial for combination CDGP and 5-FU to determine whether this chemotherapy has the potential effect of combination with CDDP and 5-FU. First of all, we tried to determine the maximum dose and recommended dose of CDGP in the combination with CDGP and 5-FU by the dose finding regulation method used in combination phase I study. We determined the maximum dose of CDGP as 120 mg/m2, and the recommended dose as 100 mg/m2 with CDGP and 5-FU, 700 mg/m2/day for 5 days. Thirteen cases were treated with CDGP and 5-FU by the recommended dose. Three cases showed CR, and seven cases showed PR. The response rate was 76.9%. Two cases showed hematological toxicity, one grade 3 platelet decreasing and the other grade 3 leucopenia. Two cases showed renal toxicity less than grade 2. Nausea and vomiting were mild. The combination with CDGP and 5-FU seemed to have a strong effect and low toxicity. Further study will be needed to determine the efficacy against head and neck cancer.

Aged↗