Biomedical subjects

Makoto Oda

Publications and source records attributed to Makoto Oda.

At least 37 records · Page 2Linked to original sources

PubMed2005

A surgical case of lung cancer in a patient with the left superior and inferior pulmonary veins forming a common trunk.

The anatomical abnormalities of the pulmonary veins may have a serious impact on complications that may arise during pulmonary lobectomy. We present a surgical case of left lung cancer in a patient, who was a 69-year-old male, with the left superior and inferior pulmonary veins forming a common trunk outside the pericardium. In this present case, because of extensive adhesions, incomplete lobulation, and tumor infiltration of the main pulmonary artery, we could not identity the common trunk with certainty before excising the left upper lobe. Although this patient was fortunately discharged without complications, there was no choice but to perform pneumonectomy because of the interruption of the inferior pulmonary vein. Retrospectively, the preoperative CT films showed the anatomical anomalies involving the pulmonary veins. However, since the length of the common trunk outside the pericardium was short and the inferior pulmonary vein was thinner than usual and its venous distribution conformed to a normal structure, the anatomy appeared normal. In excising the pulmonary lobe, it is mandatory to ascertain the distribution of the vascular system prior to surgery.

Aged, 80 and over↗

PubMed2005

Long-term survival cases of lung cancer presented as solitary bone metastasis.

The prognosis of non-small cell lung carcinoma (NSCLC) with bone metastasis has been regarded as very poor. We report herein on two cases of NSCLC which presented as a solitary bone metastasis, were treated with surgical resection. Both these cases survived for over 5 years after their last operations. A 71-year-old-man was hospitalized with right crural pain. A diagnosis of squamous cell carcinoma of the left lower lobe with right fibula metastasis was made. A marginal resection of the right fibula was performed. After that, a left lower lobe lobectomy and systemic chemotherapy were carried out. He had a local recurrence in the right mediastinal lymph nodes eleven months after the operation. He received intraluminal and external radiation therapy and obtained complete remission. He has survived for 5 years without any other recurrence or metastasis. A 52-year-old-man was admitted to our hospital with left thigh pain. A diagnosis of adenocarcinoma of the right upper lobe with left thigh metastasis was made. A right upper lobe lobectomy and a resection of the left thigh tumor were performed. Three cycles of systemic chemotherapy were given after that. He has survived for 5 years since his last operation without any recurrence or metastasis.

Adenocarcinoma↗

PubMed2004

Spontaneous regression of lung metastasis in the absence of tumor necrosis factor receptor p55.

In order to clarify the roles of tumor necrosis factor (TNF)-alpha in lung metastasis, we injected Renca cells intravenously into TNF receptor p55-deficient (TNF-Rp55 KO) and wild-type (WT) mice. Microscopic and macroscopic metastasis foci appeared in lungs at 7 and 14 days after the tumor injection, respectively. Moreover, metastasis foci expanded at similar rates in both WT and TNF-Rp55 KO mice until 21 days, and lungs were occupied with metastasis foci. However, later than 21 days after the injection, metastasis foci spontaneously regressed in TNF-Rp55 KO mice, whereas WT mice exhibited a progressive growth of metastasis foci. Moreover, metastasis foci remained reduced sizes in TNF-Rp55 KO mice even at 26 days, when all WT mice died with lungs filled with metastasis foci. Later than 21 days after the tumor injection, the number of apoptotic tumor cells was increased in TNF-Rp55 KO mice. In contrast, neovascularization was less evident in TNF-Rp55 KO than WT mice, with depressed hepatocyte growth factor (HGF) gene in TNF-Rp55 KO mice at 21 days after the tumor injection. Thus, TNF-Rp55-mediated signals can maintain tumor neovascularization at least partly by inducing HGF expression, and eventually support lung metastasis process.

Animals↗

PubMed2004

Extended thymectomy in patients with myasthenia gravis with high thoracic epidural anesthesia alone.

Successful extended thymectomy was performed in three patients with myasthenia gravis under only high thoracic epidural anesthesia with voluntary breathing. It was not necessary to intubate a tracheal tube during operation for any of the patients. Neither muscle relaxants nor volatile anesthetic agents were required. The mean operating time was 2.0 +/- 0.5 hours. The drainage tubes were removed the day after operation in all patients. In two patients the arterial oxygen saturation (SaO2) and the arterial partial pressure of carbon dioxide (PaCO2) and oxygen (PaO2) were stable; in the third patient the SaO2 was temporarily decreased to 92 mmHg when bilateral mediastinal pleura were opened. The right pleural defect was then covered with a large wet towel, which was pressed on the defect, and thoracic drainage was performed. The left pleural defect was repaired with 3-0 Vicryl after suctioning the air in the pleural space, after which the SaO2 recovered. All patients were able to drink water and walk within 1 hour after the operation. This procedure is advantageous in that the use of muscle relaxants and volatile anesthetic agents prevented the laryngeal injury that results from translaryngeal intubation; in turn we avoided causing postoperative respiratory insufficiency. This may be suitable for the operation of some patients with MG, but further studies are required to define the indication.

Adult↗

PubMed2004

The combination assay with circulating vascular endothelial growth factor (VEGF)-C, matrix metalloproteinase-9, and VEGF for diagnosing lymph node metastasis in patients with non-small cell lung cancer.

BACKGROUND: The aim of the present study was to evaluate the diagnostic utility of levels of circulating vascular endothelial growth factor (VEGF)-C, matrix metalloproteinase-9 (MMP-9), and VEGF and to verify that the combination assay of these circulating factors is a clinically useful indicator to predict the presence of lymph node metastasis in non-small cell lung cancer (NSCLC). METHODS: A series of 78 patients who underwent surgery for NSCLC was used in this study. Serum VEGF-C and VEGF and plasma MMP-9 levels were analyzed with enzyme-linked immunosorbent assay (ELISA) kits. Logistic regression models were used to analyze the influence of VEGF-C, MMP, and VEGF levels on the probability of presence or absence of lymph node metastasis. RESULTS: Patients with lymph node metastasis had higher serum VEGF- C, VEGF, and plasma MMP-9 concentrations than did those without metastasis (VEGF-C, P = .0004; VEGF, P = .001). Serum VEGF- C reached a sensitivity of 85% and specificity of 68% when a cutoff value of 1762.0 pg/mL was applied, while VEGF reached 80% sensitivity and 59% specificity at 316.8 pg/mL. MMP-9 reached a sensitivity of 63% and specificity of 75% when a cutoff value of 51.4 ng/mL was applied. In the ROC curve analysis, VEGF-C (0.761) had the biggest areas under the ROC curve, followed by MMP-9 (0.723) and VEGF (0.694). Combination assay of three markers had higher sensitivity and specificity for prediction than single-marker assays (AUC = 0.837). CONCLUSIONS: This study has confirmed that combination assay of three markers to determine VEGF-C, MMP-9, and VEGF expression in circulation detects lymph node metastasis in NSCLC with higher accuracy than single-marker assays.

Adult↗

PubMed2004

Overexpression of E2F1 associated with LOH at RB locus and hyperphosphorylation of RB in non-small cell lung carcinoma.

PURPOSE: E2F1 plays a critical role in cell proliferation, and its function is controlled by the retinoblastoma (RB) protein. We examined the expression of E2F1 and the aberration of RB gene and protein to elucidate what factors contribute to the overexpression of E2F1 in non-small cell lung carcinomas. METHODS: The expression level of E2F1 in tissues of non-small cell lung carcinomas was measured by means of quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. For RB, we examined loss of heterozygosity (LOH) by PCR-restriction fragment length polymorphism and a variable number of tandem repeats, and protein expression by immunohistochemistry. RESULTS: Fifteen cases of carcinoma (46%) showed high transcription levels of E2F1 gene. Immunohistochemically, almost all (14 of 15) cases overexpressing E2F1 mRNA were positive for E2F1 protein. LOH at the RB locus was found in 13 of 30 informative cases. In 13 cases with LOH, ten showed overexpression of E2F1 mRNA and protein. Immunohistochemical positivity for phosphorylated RB protein was also closely correlated with overexpression of E2F1. CONCLUSIONS: Our results suggest that overexpression of E2F1, induced both by LOH at the RB locus and anomalous phosphorylation of the RB protein, is involved in the development of non-small cell lung carcinoma.

Adenocarcinoma↗

PubMed2004

Acinic cell carcinoma of the trachea: report of a case.

Acinic cell carcinoma (ACC) is a very rare primary tracheal carcinoma. We report a case of primary ACC of the trachea, which represents, to the best of our knowledge, only the fifth such case ever documented. Pharyngolaryngoesophagectomy was necessary for complete resection because the tumor invaded the trachea widely, up to the cricoid cartilage and involving the cervical esophagus. Although invasion of the upper aerodigestive tract by neoplasma is rare, to achieve complete resection and an acceptable prognosis, even a tumor with low malignancy requires wide resection.

Carcinoma, Acinar Cell↗

PubMed2004

Experimental study of extracorporeal lung resection in dogs: ex situ sleeve resection and autotransplantation of the pulmonary lobe after extended pneumonectomy for central lung cancer.

OBJECTIVE: Extracorporeal lung resection as an alternative to pneumonectomy for central lung cancer is a procedure in which the unilateral lung is extirpated, removing the pulmonary lobe with the cancers and replanting the residual pulmonary lobe. The aim of this study was to investigate whether extracorporeal lung resection for lung cancer can be performed safely. METHODS: Nineteen dogs were divided into the control and extracorporeal lung resection groups. The former (n = 5) underwent lung autotransplantion, and the latter was subdivided into ND1 (n = 7) and ND2 (n = 7) groups on the basis of the manner of lymph node dissection. By comparing the 3 groups, the adverse effects of lymph node dissection were examined. RESULTS: All dogs in the control group had no complications. Four dogs in the ND1 group survived for 90 to 630 days after the operation. In the ND2 group 5 dogs succumbed within 30 days after the operation, although the other 2 dogs survived for 391 and 573 days, respectively. Bronchopulmonary fistulas were seen in 1 of the ND1 dogs and 3 of the ND2 dogs. Two of the latter were free of thrombus formation in the pulmonary arteries and veins of the autografts. In the ND2 group, compared with the control and ND1 group, the tissue blood flow at the bronchial anastomotic site indicated reduction between the 3rd and 14th postoperative days. CONCLUSION: The extensive lymph node dissection had severe adverse effects on bronchial anastomotic healing in extracorporeal lung resection. Therefore extracorporeal lung resection can be applied to only a very limited number of patients with N0 or N1 disease.

Anastomosis, Surgical↗

PubMed2004

Vascular endothelial growth factor expression in metastatic pulmonary tumor from colorectal carcinoma: utility as a prognostic factor.

OBJECTIVE: To define the most reliable prognostic factor, we studied the 5-year survival of patients after resection of pulmonary metastases from colorectal cancer in relation to various prognostic factors, including vascular endothelial growth factor expression in primary and metastatic tumors. METHODS: A retrospective study was undertaken in 49 patients who had undergone complete resection of pulmonary metastasis from colorectal carcinoma. All patients were retrospectively analyzed for sex, age, location and stage of primary tumor, number of pulmonary metastases, type of pulmonary resection, size of metastatic tumor, lymph node metastasis, and prethoracotomy carcinoembryonic antigen level. Furthermore, vascular endothelial growth factor expression of both primary and metastatic tumors was investigated. RESULTS: Overall 5-year survival was 34.3%. In the univariate analysis the number of pulmonary metastases (P =.007) and vascular endothelial growth factor expression in metastatic tumors (P =.008) and primary colorectal tumors (P =.011) were significantly associated with poor survival. In the multivariate analysis the number of pulmonary metastases (P =.0031), vascular endothelial growth factor expression in metastatic tumors (P =.0057), and stage of primary tumor (P =.0321) were characteristics that retained a significant independent prognostic effect on overall survival. A statistically significant difference was not found in the 5-year survival of patients with solitary and negative vascular endothelial growth factor expression in metastatic tumors (59.1%) versus those with multiple and positive vascular endothelial growth factor expression in metastatic tumors (10.0%; P <or=.0001). CONCLUSIONS: Vascular endothelial growth factor expression in metastatic pulmonary tumors is an important prognostic marker for patients with pulmonary metastasis from colorectal carcinoma. Our results suggested that patients with multiple and positive vascular endothelial growth factor expression in the metastatic tumor will not receive benefit from metastasectomy.

Biomarkers, Tumor↗

PubMed2004

Primary chondromatous osteosarcoma of the pulmonary artery.

Primary pulmonary sarcoma is an extremely rare malignancy, pulmonary osteogenic sarcoma is even more rare and has a poor prognosis. We present a report of a 58-year-old woman with primary pulmonary osteosarcoma occupying the right main pulmonary artery and extending to the main pulmonary artery. Right pneumonectomy was performed with total right main pulmonary artery resection under cardiopulmonary bypass. Microscopic examination demonstrated that tumor cells contained mainly chondromatous components and were atypical cells that became osteoid. There is no sign of recurrence 24 months postoperatively. The present case is the only case yet reported with even an intermediate-term survival without recurrence.

Female↗

PubMed2004

Increased matrix metalloproteinase-2 and membrane type 1 matrix metalloproteinase activity and expression in heterotopically transplanted murine tracheas.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is the most common long-term cause of morbidity and mortality after heart-lung or lung transplantation. One pathologic feature of BOS is infiltration of fibroblasts and connective tissue products into the airway lumen, which form a fibrous, collagen-rich occlusion. Heterotopically transplanted allogeneic murine tracheal stenosis resemble BOS in the development of obliterans airway disease. Matrix metalloproteinases (MMPs) are key enzymes involved in tissue remodeling and, clinically, have several roles in pulmonary diseases. Among the MMP family, type IV collagenases, MMP-2 and MMP-9, have high gelatinolytic activity and are thought to play a role in several pulmonary diseases. Membrane type 1 MMP (MT1-MMP) activates the zymogen of MMP-2 (proMMP-2, 72 kd), and activated MMP-2 (active MMP-2, 62 kd) degrades type IV collagen and plays an important role in clinical pulmonary disease. In this study, we examine the expression of MMP-2, its activator MT1-MMP and MMP-9 in BOS using murine trachea transplantation models. METHODS: Rats were divided into 5 experimental groups (n = 10 in each group). Group I was a control group with intact tracheas. Animals with tracheal grafts underwent heterotopically syngeneic (Groups II and III) or allogeneic (Groups IV and V) transplantation. The recipient rats were killed 7 days (Groups II and IV) or 28 days (Groups III and V) after transplantation. The harvested tracheal grafts were examined histologically. MMP activity was assessed using gelatin zymography analysis, and MMP-2 and MT1-MMP gene expression was examined by quantitative real-time polymerase chain reaction analysis. Distribution of gelatinolytic activity was studied using in situ zymography. RESULTS: There was little histologic change in the intact trachea (Group I) and in all isografts (Groups II and III). Fibrotic tissues in Group V significantly occluded the tracheal lumen, and there was severe lymphocyte infiltration in Group IV. According to gelatin zymography, proMMP-9 was faint at 7 days, but activated MMP-9 was not present in all groups. The MMP-2 gelatinolytic bands were predominant; the activation in Group V was significantly greater than that in Group IV, and in Group III it was significantly greater than that in Group II. Gene expression of both MMP-2 and MT1-MMP were significantly higher in Group V than in the other groups (p < 0.01), and MMP-2 was clearly activated. Gelatinolytic activity was localized in the fibrotic tissues or lymphocytes of thickening lumen after destruction of the epithelium by stenosis. CONCLUSIONS: These results demonstrate that MMP-2, together with its activator MT1-MMP, may have an important role in the development of BOS, which is associated with destruction of the tracheal epithelium, leading to fibrosis.

Animals↗

PubMed2004

A new technique of fixing a costal coaptation pin after resection of rib segment.

The Poly-L-lactide costal coaptation pin is an effective device in chest wall reconstruction. However, fixation is sometimes incomplete, despite the use of the costal coaptation pin. We report here the use of two suture techniques for the fixation of the incised ribs with costal coaptation and discuss the effectiveness of these procedures. We used the Poly-L-lactide costal coaptation pin in 174 cases of posterolateral thoracotomies with two suture methods. In one method the rib was generally fixed with suture only (L-method, n = 30), and in the H-method pairs of holes were made at the end of the incised ribs for ligating with sutures (H-method, n = 144). The effectiveness of each method was evaluated based on the degree of fixation and lateral shift 24 months postoperatively. Lateral shift was none in 114 (79.2%) cases using the H-method and 18 (60.0%) cases using the L-method. Fixation was good in 131 (91.0%) cases using the H-method but in only 20 (66.7%) cases using the L-method. H-method was significantly more effective than the L-method of costal coaptation. The H-method was very effective for fixing incised ribs and is convenient for use by thoracic surgeons.

Aged↗

PubMed2004

Chest CT and serum vascular endothelial growth factor-C level to diagnose lymph node metastasis in patients with primary non-small cell lung cancer.

STUDY OBJECTIVE: Accurate tumor staging is essential for choosing the appropriate treatment strategy for lung cancer. CT of the chest is the most commonly used noninvasive staging method of the lymph node metastasis, but it is far from satisfying. We evaluated whether circulating vascular endothelial growth factor (VEGF)-C could give additional information for diagnosing lymph node metastasis in patients with lung cancer. PATIENTS AND METHOD: Serum samples were obtained from 116 patients with primary non-small cell lung cancer (NSCLC). All patients underwent preoperative CT of the thorax. Clinical T and N stages were compared to the final T and N stages obtained from pathologic findings. Serum VEGF-C concentration was assayed by commercially available sandwich enzyme-linked immunosorbent assay. We evaluated the utility of serum VEGF-C level as a marker for nodal metastasis comparing the utility of CT. RESULTS: Preoperative and final T categories completely agreed in 82.8%. Regarding nodal metastasis, the accuracy of CT was 68.1%. Patients with lymph node metastasis showed higher serum VEGF-C concentrations than those without lymph node metastasis (p = 0.0007). Serum VEGF-C reached the highest sensitivity and specificity in diagnosing lymph node metastasis when a cut-off value of 1,850.6 pg/mL was applied (sensitivity, 70.0%; specificity, 77.3%). Serum VEGF-C visually correlated with CT scan in the detection of lymph node metastasis (sensitivity, 74.0%; specificity, 80.3%; positive predictive value, 74.0%; negative predictive value, 80.3%; accuracy, 77.6%). When the cases were limited to adenocarcinoma, better results could be obtained. CONCLUSIONS: Serum VEGF-C is a reliable marker for lymph node metastasis in NSCLC. Serum VEGF-C evaluation and CT examination are complementary to each other for accurate lymph node staging in NSCLC.

Adenocarcinoma↗

PubMed2004

[Accuracy of absorbed dose calculation and measurement of scatter factors with different depth of mini-phantoms using a pinpoint ionization chamber].

The output factor of high-energy X-ray machines varies with collimation. According to Khan's theory, collimator and phantom scatter factors contribute to total scatter factor. For precise X-ray irradiation, the two factors need to be taken into consideration. To obtain proper factors, we made two original polystyrene cylindrical mini-phantoms. These phantoms are both 4 cm in diameter and have a pinpoint ion chamber placed at a depth of 5 cm and 10 cm, respectively. Using a 6 MV X-ray machine, collimator scatter factors were calculated for various field arrangements (i.e., field sizes ranging from 4 cm x 4 cm to 40 cm x 40 cm at isocenter). To determine if calculated values were appropriate, we measured point doses of 20 X-ray irradiation patterns using a Farmer-type ion chamber with a water equivalent phantom at depths of 5 cm and 10 cm, respectively. Two hundred MUs were irradiated to the above-mentioned depths for each field. Based on the measured doses, variations were obtained for four calculation methods. Accounting for 1) secondary collimator (jaw) setting, 2) blocked field (multi-leaf collimator) setting, 3) Khan's theory using a 5 cm mini-phantom, and 4) Khan's theory using a 10 cm mini-phantom. Dose variations in each method of calculation were as follows: 1) +0.3 to +10.2% (mean, +2.0 to +3.2%) , 2) -2.3 to 0.0% (mean, -0.8 to -0.6%), 3) 0.0 to +1.5% (mean, +0.1 to +0.3%), 4) 0.0 to +1.4% (mean, -0.1 to +0.1%).

Phantoms, Imaging↗

PubMed2003

Tumor location, cirrhosis, and surgical history contribute to tumor movement in the liver, as measured during stereotactic irradiation using a real-time tumor-tracking radiotherapy system.

PURPOSE: To investigate the three-dimensional (3D) intrafractional motion of liver tumors during real-time tumor-tracking radiotherapy (RTRT). MATERIALS AND METHODS: The data of 20 patients with liver tumors were analyzed. Before treatment, a 2-mm gold marker was implanted near the tumor. The RTRT system used fluoroscopy image processor units to determine the 3D position of the implanted marker. A linear accelerator was triggered to irradiate the tumor only when the marker was located within a permitted region. The automatically recorded tumor-motion data were analyzed to determine the amplitude of the tumor motion, curve shape of the tumor motion, treatment efficiency, frequency of movement, and hysteresis. Each of the following clinical factors was evaluated to determine its contribution to the amplitude of movement: tumor position, existence of cirrhosis, surgical history, tumor volume, and distance between the isocenter and the marker. RESULTS: The average amplitude of tumor motion in the 20 patients was 4 +/- 4 mm (range 1-12), 9 +/- 5 mm (range 2-19), and 5 +/- 3 mm (range 2-12) in the left-right, craniocaudal, and anterior-posterior (AP) direction, respectively. The tumor motion of the right lobe was significantly larger than that of the left lobe in the left-right and AP directions (p = 0.01). The tumor motion of the patients with liver cirrhosis was significantly larger than that of the patients without liver cirrhosis in the left-right and AP directions (p < 0.004). The tumor motion of the patients who had received partial hepatectomy was significantly smaller than that of the patients who had no history of any operation on the liver in the left-right and AP directions (p < 0.03). Thus, three of the five clinical factors examined (i.e., tumor position in the liver, cirrhosis, and history of surgery on the liver) significantly affected the tumor motion of the liver in the transaxial direction during stereotactic irradiation. Frequency analysis revealed that for 9 (45%) of the 20 tumors, the cardiac beat caused measurable motion. The 3D trajectory of the tumor showed hysteresis for 4 (20%) of the 20 tumors. The average treatment efficiency of RTRT was 40%. CONCLUSIONS: Tumor location, cirrhosis, and history of surgery on the liver all had an impact on the intrafractional tumor motion of the liver in the transaxial direction. This finding should be helpful in determining the smallest possible margin in individual cases of radiotherapy for liver malignancy.

Computer Systems↗

PubMed2003

The effects of a specific neutrophil elastase inhibitor (ONO-5046) in pulmonary ischemia-reperfusion injury.

Ischemia-reperfusion injury is a significant problem in lung transplantation. Polymorphonuclear elastase derived from neutrophils plays a major mechanistic role in this process. Hence, we have investigated the effects of ONO-5046, a neutrophil elastase inhibitor, on ischemia-reperfusion injury. Fifteen rabbits were divided into three groups: 2 h of single left-lung perfusion (control group, n=3); 2 h of ischemia followed by 2 h of reperfusion (ischemic group, n=6); and drip intravenous administration of ONO-5046 during the 2 h of ischemia and 2 h of reperfusion (ONO-5046 group, n=6). Hemodynamic parameters were determined and a histopathological examination of the lung was performed. In the ONO-5046 group, arterial oxygen pressure, cardiac output, and tissue blood perfusion were higher and pulmonary vascular resistance was lower than in the ischemic group. The ONO-5046 group also showed large decreases in neutrophil infiltration, pulmonary edema, and intra-alveolar hemorrhage. Treatment with ONO-5046 improves lung function in a rabbit-lung ischemia-reperfusion model.

Animals↗

PubMed2003

Thymic carcinoid tumor.

In this report on 3 cases of thymic carcinoid, tumors recurred in 2 patients not undergoing lymph node dissection. We review 47 cases of this disease taken from the Japanese literature, and discuss surgical procedures for reducing recurrence. In 9 of 20 cases of recurrence in encapsulated thymic carcinoid, lymph nodes were not dissected in eight. Differential diagnosis of an anterior mediastinal tumor should include thymic carcinoid, for which lymph nodes should be routinely dissected, even when the tumor is encapsulated.

Adult↗

PubMed2003

Effect of single-drug treatment on idiopathic sudden sensorineural hearing loss.

OBJECTIVES: In order to evaluate the effect of a medical administration for the sudden deafness patients, single-drug treatment for idiopathic sudden sensorineural hearing loss (ISSHL) was assessed at multi-centers participating in the Acute Severe Hearing Loss Study Group sponsored by the Ministry of Health, Labor and Welfare of Japan. METHODS: The subjects consisted of ISSHL patients who were (1) 20 years of age or older, (2) diagnosed within 2 weeks after the onset of hearing loss, (3) showing a mean hearing level of 40-90 dB at five frequencies from 250 to 4000 Hz, (4) previously untreated, and (5) with normal for age in hearing of the opposite ear. The drugs used in this study were ATP, alprostadil, hydrocortisone and amidotrizoate, which were administered intravenously, and beraprost sodium and betamethasone, which were given orally. Two drugs were assigned to each center, one of which was selected according to the code hidden in envelopes and administered for 1 week. The treatment after the single-drug administration was conducted at the discretion of each center. The hearing gain and recovery rate at 1 week after the initiation of single-drug treatment and at 1 month or over when the hearing level was fixed, were evaluated based on the criteria for hearing recovery prepared by the Acute Severe Hearing Loss Study Group. RESULTS: There was no statistically significant difference in the recovery rate among drugs either at 1 week after the initiation of single-drug treatment or at the time of fixed hearing level. At the time when the hearing level was fixed, a statistically significant difference in the complete recovery rate was detected only between amidotrizoate and beraprost sodium. CONCLUSION: From these results, we could not find any specific drugs recommended for ISSNHL. In evaluating the effect of the drugs, however, several problems in the clinical trial for ISSHL should be considered.

Adenosine Triphosphate↗