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Biomedical subjects

Satoshi Kitahara

Publications and source records attributed to Satoshi Kitahara.

At least 19 recordsLinked to original sources
PubMed2006

Effects of 138-355, a beta3-adrenoceptor selective agonist, on relaxation of the human detrusor muscle in vitro.

AIMS: Beta-adrenoceptors are the predominant beta-adrenoceptor subtype present in the bladder and urethra. This study investigates the effects of 138-355, an active-metabolite of TT-138 and beta(3)-adrenoceptor agonist, on relaxation of the human detrusor in vitro. METHODS: Tumor-free tissue samples of human bladder muscle from 39 patients undergoing total cystectomy due to bladder cancer were obtained, and the mucosa and serosa were removed. Tissues were mounted in 5 or 10 ml organ baths containing Krebs solution, which was gassed with 95% O(2) and 5% CO(2). Resting tension of 1 g was obtained. When the contraction had stabilized, increasing concentrations of beta adrenoceptor agonists (non-selective, isoprenaline; beta(2)-selective, clenbuterol; beta(3)-selective, 138-355 and BRL37344) and propiverine (a non-selective anti-muscarinic antagonist) were added cumulatively and concentration-relaxation curves (CRCs) were obtained. CRCs to 138-355 were obtained in the absence and presence of SR59230A, a beta(3)-selective antagonist, and antagonist affinity values (pA(2)) were calculated from the Schild plot. RESULTS: Isoproterenol, clenbuterol, 138-355 and BRL37344 concentration-dependently relaxed isolated human urinary bladder strips with pEC(50) value being 6.76+/-0.17, 5.23+/-0.22, 5.80+/-0.26 and 5.90+/-0.28, respectively. Following antagonist assay, it was observed that concentration-relaxation curves to 138-355 was competitively antagonized by beta(3)- adrenoceptor antagonist, SR59230A, with a pA(2) value of 7.01+/-0.45 and with a Schild slope of 0.72+/-0.07. CONCLUSIONS: Involvement of the beta(3)-adrenoceptor appears to be greater than that of the beta(3)-adrenoceptor for relaxations of the human bladder. The relaxation response of 138-355 appears to be mediated via the beta(3)-adrenoceptor stimulation.

Adrenergic beta-3 Receptor Agonists↗
PubMed2006

[Effects of one-way speaking valve placement on swallowing physiology for tracheostomized patients: impact on laryngeal clearance].

Tracheostomy placement affects swallowing function, increasing the risk of aspiration. Recent studies suggest that because of increased risk of swallowing disturbance associated with tracheostomy, one-way speaking valve placement may help to reduce aspiration in tracheostomized patients. We hypothesize that airflow exhaled through the laryngeal cavity using the one-way speaking valve may improve the clearance of residual bolus from the upper airway, thus preventing bolus penetration and aspiration. We studied the effects of one way speaking valve placement on laryngeal clearance and swallowing physiology. Videoendoscopic and videofluoroscopic swallowing were examined in 16 patients with the tracheostomy, and swallowing was compared with and without the one-way speaking valve in place. Valve Valve placement significantly improved laryngeal clearance and the incidence of penetration during swallowing. placement did not, however, significantly affect pharyngeal bolus residue, laryngeal elevation, pharyngeal delay or aspiration. Factors associated with the resumption of oral feedings were sufficient laryngeal elevation during swallow and the prevention of laryngeal penetration and aspiration. We concluded that one-way speaking valve placement improves laryngeal clearance and prevents laryngeal penetration, resulting in better oropharyngeal swallowing physiology and oral feeding.

Adult↗
PubMed2005

Fat-containing variant of solitary fibrous tumor (lipomatous hemangiopericytoma) arising on surface of kidney.

Fat-containing variant of a solitary fibrous tumor is a recently recognized benign soft-tissue tumor that usually affects the thigh and retroperitoneum. We report a 51-year-old woman with a fat-containing variant of a solitary fibrous tumor that is the first reported case involving a visceral organ. The tumor was well delineated and seemed to arise from the renal capsule, radiographically and macroscopically. The tumor microscopically mimicked a solitary fibrous tumor but exhibited focal aggregates of fat cells. A fat-containing variant of a solitary fibrous tumor involving the kidney should be distinguished from spindle cell carcinoma, angiomyolipoma, gastrointestinal stromal tumor, and cellular schwannoma.

Adipose Tissue↗
PubMed2005

Expression of KIT, EGFR, HER-2 and tyrosine phosphorylation in undifferentiated thyroid carcinoma: implication for a new therapeutic approach.

The KIT, epidermal growth factor receptor (EGFR) and HER-2 oncoproteins have tyrosine kinase activity and are molecular targets in human cancer therapy. To clarify the significance of KIT, EGFR, and HER-2 in undifferentiated thyroid carcinoma (UTC), the expression of these receptors and tyrosine phosphorylation was examined immunohistochemically in resected cases of UTC and papillary thyroid carcinoma (PTC). KIT, EGFR, and HER-2 were also examined at the protein and mRNA levels in five UTC cell lines. KIT expression (1+), EGFR overexpression (2+/3+), HER-2 expression (1+), and tyrosine phosphorylation were detected immunohistochemically in 40%, 70%, 10%, and 50% of the 10 UTC. In 20 PTC, KIT, EGFR, and HER-2 were not detected, but tyrosine phosphorylation was detected in 25% of cases. In the five UTC cell lines, KIT expression (1+), EGFR overexpression (3+), HER-2 expression (1+), and tyrosine phosphorylation were detected immunocytochemically in 60%, 100%, 20%, and 40%, respectively. Western blot analysis did not detect KIT expression, but did detect EGFR and HER-2 expression in all five cell lines. Real-time polymerase chain reaction detected KIT mRNA in two of the cell lines (40%), EGFR in five (100%), and HER-2 in three (60%). The present findings suggest that EGFR overexpression was involved in the proliferation and development of UTC and was frequently accompanied by tyrosine phosphorylation. Expression of KIT and HER-2 appeared to be weak but significant, suggesting a possible role in the development of UTC. Molecular therapies targeting KIT, EGFR, HER-2, and/or tyrosine phosphorylation might be indicated for UTC.

Antigens, Neoplasm↗
PubMed2005

Vocal fold injury following endotracheal intubation.

Vocal fold scarring results in the formation of fibrous tissue which disturbs the vibratory pattern of the fold during phonation. However, vocal fold scarring in humans is poorly understood because of the lack of clear case reports focusing on voice quality. The authors present a case of vocal fold scarring with changes in voice quality. At the time of injury the pedicle mucosa was cemented with fibrin glue. Phonation was inhibited for two weeks and tranilast (300 mg/day) was given for 3 months. Sixty-nine days later, perceptual evaluation showed a normal result and the phonation time became better, but the mucosal vibration was still lacking. Ninety-seven days later, mucosal vibration was finally restored. We suggest that characterization of vocal fold scarring in humans may be different from that in animals, and recommend that surgical management should be avoided for at least three months after injury.

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↗
PubMed2004

Correlation between lower urinary tract symptoms and urethral function in benign prostatic hyperplasia.

AIM: To examine the potential correlation between urethral function and lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH). METHODS: Thirty-one patients with clinical BPH, who were confirmed to have benign prostatic enlargement (BPE) of 20 ml or more, were enrolled into the study. A mark-sheet questionnaire was used for obtaining the LUTS history. Multichannel pressure-flow urodynamic studies were performed and external urethral sphincter pressure (PEUS), intravesical pressure (PVES), and bladder neck pressure (PBN) were recorded both at maximum cystometric capacity and during voiding with 5-microtip transducers, for the purpose of detecting BPE-specific urodynamic findings at different levels within the urethra. RESULTS: There was a positive correlation between hesitancy and detrusor bladder neck dyssynergia (DBND) (P = 0.0011) and between incomplete emptying and low PBN at maximum cystometric capacity (P = 0.0425). The hesitancy proved to have no correlation with bladder neck opening time (TBNO). CONCLUSION: Urodynamic evaluation of urethral function was beneficial for attributing LUTS to clinical BPH. Among various parameters, DBND was the most specific to clinical BPH, suggesting it to be a situation where a steep rise in PBN or prostatic urethral pressure remains greater than the increasing PVES, resulting in sustained difficulty in opening the bladder neck and subsequently the subjective sensation of hesitancy.

Aged↗
PubMed2004

A pilot study evaluating a new questionnaire for prostatic symptom scoring, the SPSS, and its sensitivity as constructed to objective measures of outflow obstruction.

AIM: To evaluate the extent to which our newly developed questionnaire, the Saitama Prostate Symptom Score (SPSS), for prostatic symptom scoring reflects objective findings in benign prostatic hyperplasia (clinical BPH) and to compare it with the International Prostate Symptom Score (IPSS) with regard to diagnostic sensitivity in clinical BPH. METHODS: In this study, both the SPSS and the IPSS were self-administered by patients. Free uroflowmetry, a pressure-flow study and the measurement of prostatic volume were carried out. RESULTS: There was no significant correlation between the results of the IPSS questionnaire and the urethral obstruction grade estimated by Schaefer or Abrams-Griffiths nomograms. The total score of the SPSS was correlated with these nomograms (P = 0.0487 and P = 0.0413, respectively). There was no significant correlation between the results of the IPSS questionnaire and the total volume or transition zone volume of the prostate, whereas the total score of the SPSS correlated with the total volume of the gland and transition zone volume (P = 0.0044 and P= 0.0051, respectively). CONCLUSION: This study revealed the SPSS to correlate with objective findings satisfactorily. However, there are still several aspects of the SPSS which need to be improved upon, and the questionnaire should be studied in larger numbers of patients suffering from lower urinary tract symptoms.

Aged↗
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

Changing concepts in urological management of the congenital anomalies of kidney and urinary tract, CAKUT.

Recent advancement in ultrasonographic evaluation has prompted early detection and diagnosis of congenital anomalies in the kidney and urinary tract (CAKUT) in the asymptomatic phase. Consequently, early surgical intervention has become possible in the asymptomatic phase for the purpose of controlling manifestations early, thereby avoiding renal functional deterioration. However, some lesions detected by ultrasonography have been shown to often resolve or disappear without intervention. Thus, it has become more important to identify and understand the natural history of CAKUT. For the precise evaluation of the results of surgical intervention, one must understand the maturational process of renal function during infancy. Without considering this process, we cannot differentiate the renal significance of the surgical management from the natural course of CAKUT. Recent advancement in the field of radioisotopic studies has also made a major contribution to the more precise assessment of renal function. Recent progress in the understanding of the pathophysiology and the natural history of CAKUT has helped rationalize its treatment and management. Improvement in the surgical techniques and tools, together with improvements in pediatric anesthesiology, have made an appreciably positive impact on the outcome. Herein, we present the emerging concepts in the urological management of CAKUT, specifically, multicystic dysplastic kidney, vesicoureteral reflux, congenital hydronephrosis, ectopic ureters and ureteroceles.

Child↗
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

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

Direction of lateral traction in Ejnell's technique: an experimental study and case report of bilateral vocal cord paralysis.

In order to develop the method of laterofixation of the vocal cord (Ejnell's method) in cases of bilateral vocal cord paralysis, six autopsy specimens of normal larynx were obtained. We inserted traction sutures under conditions of direct visualization and studied the relationship between the direction of the traction exerted by the suture and subsequent enlargement of the glottis. When the vocal cord was pulled perpendicular to the thyroid cartilage wing, the mean glottal area was 106.2% of its area before traction. When the vocal cord was pulled perpendicular to the median line of the glottis, the mean glottal area was 112.7% of its area before traction. The latter angle of traction therefore produced more efficient enlargement of the glottis (p < 0.05; paired t-test). Based on an anatomic study of cadaveric laryngeal regions, a formula was developed to predict at which point the needle should be placed in order to produce optimal results using Ejnell's technique. Further clinical studies will be carried out in patients to test the validity of this formula.

Aged↗
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

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↗
PubMed2002

[Seminal lactate dehydrogenase C4 (LDH-C4) isozyme activity in infertile men].

Lactate dehydrogenase C4 (LDH-C4) is the specific isozyme of LDH produced by germ cells. We measured LDH-C4 activity in seminal plasma from infertile men with oligozoospermia or azoospermia using gel electrophoresis. Total LDH activity in seminal plasma from infertile patients (n = 99) was 2,487 +/- 1,384 IU/l (mean +/- SD). LDH-C4 isozyme activity was detected in 63 out of 75 seminal plasma samples from infertile patients with a mean of 383 +/- 356 IU/l (13.8 +/- 8.6% of total LDH). Sperm count was positively correlated with LDH-C4 (r = 0.298; P < 0.05), but not with any other LDH isozymes or with total LDH. Seminal LDH-C4 was significantly lower in patients with varicoceles (253 +/- 223 IU/l) than without varicoceles (474 +/- 262 IU/l). Six azoospermia patients were treated with hCG and hMG. Three out of four patients whose seminal plasma revealed LDH-C4 activity responded to the treatment, whereas none of the other two patients without seminal LDH-C4 activity did. These results indicate the clinical usefulness of seminal LDH-C4 as a potential marker for seminal epithelium activity in the diagnosis and treatment of male infertility.

Humans↗