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Biomedical subjects

K Okabayashi

Publications and source records attributed to K Okabayashi.

At least 19 recordsLinked to original sources
PubMed1998

The number of lymph node metastases influences survival in esophageal cancer.

BACKGROUND AND OBJECTIVES: Lymph node involvement adversely affects the survival of patients with esophageal cancer. We retrospectively investigated whether the number of involved lymph nodes and the degree of lymph node dissection affect survival. PATIENTS AND METHODS: Eighty-eight patients underwent surgical resection and reconstruction for T -T3 thoracic esophageal squamous cell carcinoma. Patients were classified into three groups: group 1, 32 patients without lymph node involvement; group 2, 26 patients with 1 to 3 positive nodes; and group 3, 30 patients with > or = 4 involved lymph nodes. RESULTS: The 3-year and 5-year survival rates were 34.8% and 30.0% in group 1, 30.0% and 22.7% in group 2, and 14.8% and 0% in group 3, respectively. The mean survival time (MST) X +/- SD of the patients in group 3 (453.06+/-74.5 days) was significantly shorter than in group 1 (450.1+/-450.5, P = 0.0005) and group 2 (937.3+/-1317.9, P = 0.0295). For patients in groups 1 and 2, the MST for three-field lymph node dissection (1136.9+/-1476.4 days) was longer than for two-field lymph node dissection (1007.4+/-1476.4 days, P = 0.0355). However, in group 3, there was no survival advantage to three-field lymph node dissection. CONCLUSION: We conclude that the survival in patients with thoracic esophageal cancer involving four or more nodes, is poorer than in patients with lesser involvement. Three-field lymph node dissection does contribute to prolonged survival in patients with node-negative disease or fewer than four positive nodes.

Adult↗
PubMed1998

Y-shaped tracheobronchial stent for carinal and distal tracheal stenosis.

A Y-shaped tracheo-bronchial tube was designed and used for two patients with carinal stenosis following a lower tracheal resection in one case and a malignant tracheal fistula in the other. The tube consisted of three parts including a Y-shaped, thin-walled, soft silicone stent; a spiral-wire-reinforced main tube; and a curved tracheostomy tube. The stent was inserted easily and comfortably through the tracheostomy under fiberoptic bronchoscopic guidance with minimal local anesthesia. The positioning stability of the tube was excellent because of the carina-shaped structure of the tube end. Resistance to compression was satisfactory due to the embedded spiral wire. The insertion procedure through the tracheostomy was smooth, even in patients whose respiratory condition was severe or critical. Satisfactory phonational activity was also provided by breathing through the hole on the tube back up to the vocal cord. Bronchoscopic inspection was uncomplicated, and the patients themselves could easily clean the stent. Since palliation of the airway obstruction is the main purpose of such a stent for patients with either severe lower tracheal or carinal stenosis, and because of the difficulty of ordinary stent insertion in this part of the airway, this device appears to offer excellent stability and easy insertion of the stent. In addition, the ease of maintenance and suctioning through the tracheostomal end allows for an excellent quality of life in which the patients are able to return to their homes.

Adult↗
PubMed1998

Tracheal transplantation for carinal reconstruction in dogs.

BACKGROUND: Experimental carinal allotransplantation has been performed with tracheocarinal Y-shaped allografts in dogs. In this study we tried canine carinal reconstruction with cylindrical allografts. MATERIAL AND METHODS: Carinal reconstruction was performed with allotransplantation of cylindrical trachea in dogs, and graft healing was evaluated by bronchoscopic observation, mucosal blood flow measurement, and histologic examination. A section of the recipient carina containing five tracheal rings and two main stem bronchi was removed, and a donor trachea seven rings long was inserted between the recipient trachea and the left main stem bronchus; then side-to-end anastomosis was performed between the graft midportion and recipient right main stem bronchus (new carina). The grafts were wrapped with pedicled omentum. Fresh grafts were transplanted into one group of dogs (n=8 ), and grafts cryopreserved for 1 week were transplanted into another group (n=7). RESULTS: No anastomotic leakage occurred in any dog. Excellent healing of grafts and graft anastomoses was observed by fiberoptic bronchoscopy in six dogs (75%) in the fresh graft group and in four dogs (57%) in the cryopreserved graft group. The mucosal blood flow in the new carina decreased remarkably and, although it recovered, mucosal blood flow remained under the preoperative level on day 28 after the operation. CONCLUSION: Cylindrical tracheal allotransplantation is useful for carinal reconstruction, and the method of side-to-end anastomosis between the donor trachea and recipient bronchus is a feasible and accessible procedure in dogs.

Anastomosis, Surgical↗
PubMed1998

[Therapeutic strategy for pleural mesothelioma].

Generally pleural mesothelioma is divided into two histologic types: localized and diffuse. Most cases of the former are considered to be benign and the latter malignant. The treatment strategy for these tumors has been investigated, including various surgical and chemotherapeutic approaches. In spite of these efforts. no curative method for malignant mesothelioma has been established yet, although the gene therapy is expected to be the most powerful tool in the near future.

Adult↗
PubMed1998

Extended operation for T4 lung carcinoma.

The extended surgery for T4 lung carcinoma was reviewed. From literature in the last decade, the 5-year survival rate has been under 10% worldwide. However a more favorable prognosis will be expected nowadays because of the progress of perioperative intensive care and appearance of effective anticancerous agents for induction chemotherapy. We compared the results of surgery for T4 lung carcinoma from 1978 to 1989, to those from 1992 to 1997. The 3 and 5-year survivals in the former period were 6.8% respectively, however in the latter period the 3-year survival rate rose to 24.6%. In patients with T4, the prognoses are different according to the involved organs by lung carcinoma. Generally, combined resection of the trachea, carina, descending aorta and left atrium show better prognoses compared to that of the esophagus and liver. We consider that malignant pleural effusion with N2 should not be the object for panpleuropneumonectomy. In our series from 1992 to 1997 median survival time (MST) of T4 with N0 or N1 was 25.5 months, on the other hand MST with N2 or N3 was 14.2 months. Histologically patients with squamous cell carcinoma showed a better prognosis than those with adenocarcinoma. From these results, in the extended operation for T4 we may expect more favorable prognoses in cases with involvements of the trachea, carina, aorta and left atrium, and with N0 or N1, histologically squamous cell carcinoma.

Adenocarcinoma↗
PubMed1998

Inhaled nitric oxide does not increase rat pulmonary allograft rejection.

BACKGROUND: There is evidence that inducible nitric oxide (NO) may be directly related to the process of allograft rejection. Because of its strong pulmonary vasodilatory activity, inhaled NO (INO) has recently been used as a therapeutic option for allograft dysfunction after lung transplantation. The action of inducible NO and inhaled NO seems contradictory for preserving posttransplantation pulmonary allograft function. INO used for lung transplant recipients may actually enhance acute allograft rejection. We studied the effect of INO on acute allograft rejection with a rat pulmonary allograft model. METHOD: A total of 24 left lung allotransplantations were performed from Lewis donors into F344 recipients. Animals were divided into two groups and inhaled either room air alone or 20 ppm NO with room air in a closed chamber immediately after transplantation until rats were killed on days 7 and 14. During observation, NO uptake was monitored by measuring serum NO2-/NO3- level. Acute rejection was evaluated by use of a semiquantitative radiographic scoring method (aeration score: 0 to 6, opaque to normal appearance) and rejection score (0 to 4, no sign of rejection to diffuse mononuclear infiltration). RESULTS: Markedly elevated serum NO2-/NO3- levels were observed in the NO inhalation group compared with levels in the normal air inhalation control group (110.8 +/- 25.3 vs 16.3 +/- 4.0 micromol/L/ml on day 7, p < 0.01; 107.0 +/- 30.9 vs 16.8 +/- 4.8 micromol/L/ml on day 14, p < 0.01). However, no positive effect of INO on acute rejection was found histologically or radiographically. CONCLUSION: The effect of INO on acute rejection is likely so minimal as not to be clinically relevant.

Administration, Inhalation↗
PubMed1997

Carinal resection and reconstruction for recurrent lung cancer.

A patient with a recurrent tumor in the trachea adjacent to the right main bronchus was treated by surgical resection 19 months after undergoing surgery for the primary cancer. The patient had previously undergone right upper lobectomy for T1N0M0 stage I squamous cell carcinoma. A carinal resection was performed which included 4 rings of the trachea, 2 rings of the right main bronchus, and 1 ring of the left main bronchus. Reconstruction consisted of an end-to-end anastomosis of the trachea and left main bronchus, and an end-to-side anastomosis of the right and left main bronchi. The postoperative course was uneventful, and at present the patient is healthy 12 months following reoperation.

Aged↗
PubMed1997

Free radical-mediated tissue injury in acute lung allograft rejection and the effect of superoxide dismutase.

BACKGROUND: The role of monocytes and neutrophils is crucial during acute allograft rejection. They have the capacity to generate toxic reactive oxygen intermediates in response to specific agonists that may act as tissue destructive molecules. We examined the possibility of reactive intermediate-mediated tissue injury in acute lung allograft rejection, as well as the effect of superoxide dismutase. METHODS: Allogenic (Brown Norway to F344) or syngenic (F344 to F344) rat left-lung transplantation was performed. Generation of reactive oxygen intermediates in peripheral blood was evaluated by the method of luminol-dependent chemiluminescence. Cell membrane phospholipid peroxidation in the graft was measured as malondialdehyde concentration. The third group of animals having allografts received bovine erythrocyte superoxide dismutase (5,000 U/kg intravenously every 12 hours after transplantation). RESULTS: Relative chemiluminescence response in the allograft recipient to normal F344 was elevated on postoperative day 1 (257%), then decreased slightly on day 3 (156%) and was elevated again on day 7 (560%) as the process of rejection progressed. Allograft tissue malondialdehyde levels (248.37 +/- 112.35 nM/whole lung, n = 6; p < 0.05 by Student's t test) were higher than isograft levels (139.29 +/- 35.93 nM/whole lung, n = 6) on day 7. Superoxide dismutase treatment significantly ameliorated the histologic degree of rejection on day 7. CONCLUSIONS: These results demonstrate the tissue destructive activity of reactive oxygen intermediates during lung allograft rejection. To scavenge free radicals may be a useful therapeutic modality in the management of acute lung allograft rejection.

Acute Disease↗
PubMed1997

Is video-assisted thoracoscopic surgery suitable for resection of primary lung cancer?

We investigated the validity of thoracoscopic surgery-in patients with primary lung cancer undergoing lobectomy. 14 primary lung cancer patients treated by typical VATS lobectomy and one by anatomical segmentectomy, were compared with 56 patients with Stage-I lung cancer undergoing standard lobectomy (control group), the results focusing on the lymph-nodes dissected. All 14 lobectomy patients showed primary lesions of size less than 3 cm. Following classification of the lymph-nodes into groups I (hilar lymph node) and II (mediastinal lymph node), we compared results according to the sites of the lobectomies conducted. Numbers of dissected lymph-nodes were similar in patients whether undergoing standard thoracotomy or VATS lobectomy. We also investigated what histological types of cancer should be treated by VATS lobectomy by comparing preoperative and operative staging in the control group. The results showed that in most patients with squamous-cell carcinoma judged as T1 N0 M0 the staging corresponded, the other patients actually being in N1 (Stage II). Of Patients with adenocarcinoma of T1 N0 M0, however, 14% had lymph-node metastasis even into the superior mediastinum, i.e., Stage III. The overall findings suggest at present that VATS lobectomy should be applied preferably to patients with a histological typing such as squamous cell carcinoma or alveolar cell carcinoma of relatively early stage, i.e. preoperative Stage I.

Adenocarcinoma↗
PubMed1997

Inhibition of inducible nitric oxide synthase prolongs rat lung allograft survival.

Nitric oxide (NO) has been demonstrated to be an important immunoregulation molecule in the process of cellular immunologic interactions. Our recent results demonstrated that NO is produced in association with acute allograft rejection and NO inhibition may suppress rejection histologically. This data provides direct evidence of NO in allograft rejection and the immunosuppressive potential of NO inhibitors. In this paper, the effect of NO inhibition on allograft survival was evaluated to investigate the capacity of NO inhibitors as immunosuppressive agents. Seventeen rat left lung transplants from BN donors to F344 recipients were accepted for this study. After surgery, recipients were randomized into two groups and received either aminoguanidine (AG), a highly selective NO synthase inhibitor, 200 mg/kg, intra-peritoneal every 6h (n = 13) or normal saline treatment (n = 4). No production was determined from the recipient's serum nitrite and nitrate levels. Graft survival was monitored via semi-quantitative radiographic aeration scores (AS: 0 = opaque lung to 6 = normal appearing lung). The nitrite and nitrate levels were clearly detectable before the radiographic finding associated with rejection became obvious. Production of NO was significantly inhibited by AG treatment. AG treatment prolonged allograft survival radiographically (12.0 days and 6.0 days for treated and untreated groups respectively, p = 0.0001). These data suggest that the inducible NO is produced in association with acute lung allograft rejection and may serve as a sensitive rejection marker. NO inhibition significantly prolonged rat lung allograft survival but failed to induce immunological tolerance.

Animals↗
PubMed1997

Primary tracheal fibrosarcoma in a child: a case of tracheal resection under ECMO support.

We report a case of severe airway obstruction due to endotracheal fibrosarcoma in a 3-year-old boy. Successful tracheal resection and reconstruction was performed under extracorporeal membrane oxygenation support. A solid, elastic hard tumor with a smooth surface was attached by a tiny stalk structure to the membranous part of the lower trachea. Histological findings of the tumor were consistent with infantile fibrosarcoma, showing proliferation of spindle cells forming interlacing patterns.

Airway Obstruction↗
PubMed1997

[Video-assisted thoracic surgery for lung cancer].

Video-assisted thoracic surgery (VATS) has been applied to treat patients with various pulmonary diseases. Recent advances in video endoscopic instruments have been enabled radical resection of pulmonary malignancies as minimally invasive surgery. Forty patients with primary lung cancer underwent several types of lung resection in the past 3 years at out unit. Of these, twenty-seven anatomical pulmonary resections were performed using VATS. Peripherally located, early-stage lung cancer is thought to be a potential candidate for curative surgery with video-assisted lobectomy. Although there are some pitfalls with VATS, sufficient mediastinal lymph node dissection is thought to be possible. Additionally, intrathoracic hyperthermic chemotherapy using video-assisted thoracoscope for both pleural disseminated lesion and malignant pleural effusion is described.

Cisplatin↗
PubMed1997

Video-assisted thoracoscopic lobectomy for treating lung cancer.

Our objective was to evaluate the usefulness and safety of video-assisted thoracoscopic surgery (VATS) for performing pulmonary lobectomy in 11 patients with clinical NO stage I primary non-small-cell lung cancer compared with 11 patients who underwent a conventional thoracotomy. Treatment was switched to conventional thoracotomy in three VATS patients because of the involvement of interlobar nodes or incomplete lobar fissure. None of the eight VATS patients died or experienced serious complications during 12 months of follow-up. There were no significant differences in the intraoperative blood loss, duration of operation, or duration of chest tube drainage between the VATS group and the standard lobectomy group. We conclude that although VATS lobectomy appears to be safe for use in managing patients with primary lung cancer, it does not seem to offer any advantages over standard lobectomy.

Adenocarcinoma↗
PubMed1997

[Complications of thoracoscopic surgery for spontaneous pneumothorax].

We reviewed the cases of 122 patients with primary spontaneous pneumothorax who underwent thoracoscopic surgery at our institution between 1992 and 1995. In 9 cases, thoracotomy became necessary because of severe adhesions (3 cases), large foci (3 cases), and unrecognized foci (3 cases). Complications occurred in 17 cases: collapse in 1 patient after removal of the thoracic drain, persistent air leakage (> 7 days) in 2 patients, and recurrent pneumothorax in 14 patients. There were no significant differences between the recurrent and non-recurrent cases in age, sex location of bullae, past history of pneumothorax, operating time, intraoperative blood loss, or duration of chest tube drainage after surgery. The interval between onset and consult was significantly longer in recurrent cases than in non-recurrent cases, and the number of patients who required chest tube drainage before surgery was significantly higher in recurrent cases. Reoperation was performed in 9 cases. Bullaes that were not detected during the first surgery were found in the 7 of these cases. The recurrent cases in our study were regarded as resulting from a lack of surgical skill that may improved with increasing surgical experience. The Brinkman index was significantly higher in recurrent cases. Smoking and air-leakage before surgery may be risk factors for recurrence following thoracoscopic surgery for spontaneous pneumothorax.

Adolescent↗
PubMed1996

Attenuation of rat lung isograft reperfusion injury with a combination of anti-ICAM-1 and anti-beta2 integrin monoclonal antibodies.

Four different combinations of monoclonal antibodies against rat ICAM-1, CD-11a, and CD-18 were utilized to determine the relative importance of LFA-1, Mac-1, and ICAM-1 in a rat model of severe lung allograft reperfusion injury. Negative control animals were given phosphate buffered saline (the carrier solution for the antibodies), while positive control animals were rendered neutropenic by the administration of a polyclonal mouse IgG. Antibodies were given with the donor lung flush, prior to left lung graft reperfusion, or both. Isolated graft function was determined 24 hr after implantation by arterial blood gas (ABG), and after sacrifice the native and transplanted lungs underwent bronchoalveolar lavage for alveolar protein quantitation, cell count and differential, and myeloperoxidase assay. Additionally, whole lung homogenates were assayed for myeloperoxidase activity. We found that the combination of anti-ICAM-1 (1 mg/kg) added to the donor lung flush, and anti-CD11a, anti-CD18, and anti-ICAM-1 (2 mg/kg i.v. of each) given to the recipient prior to reperfusion, resulted in significantly improved lung graft pAO2 by ABG, and decreased alveolar protein, cell count, and myeloperoxidase activity compared with control animals. Improvement was less than that seen in the neutropenic recipients, however. We conclude that LFA-1, Mac-1, and ICAM-1 are all important adhesion molecules in lung allograft reperfusion injury--yet even with antibody blockade of all three there are additional mechanisms allowing for neutrophil influx into the lungs.

Animals↗
PubMed1996

Secretory production of recombinant urokinase-type plasminogen activator-annexin V chimeras in Pichia pastoris.

To produce a thrombi-targeting plasminogen activator, we expressed a fused gene that contains a modified pre-sequence of Mucor pussilus rennin (MPR) followed by a chimeric gene of single-chain urokinase-type plasminogen activator (scu-PA)::annexin V (AV). The fused gene was ligated into an integrative vector, under the control of the alcohol oxidase 1 (AOX1) promoter (p), and transformed into Pichia pastoris. Transformants were monitored for the secretion of fibrinolytic activity. The highest expressing clone, HB225, secreted as much as 600 international units (IU) of fibrinolytic activity per ml of culture medium under optimal conditions. It contained three tandem copies of the full-size vector disruptively integrated into the AOX1 sequence. Western blot analysis revealed that the secreted chimera was highly susceptible to proteolysis. Addition of excess amino acids (aa) to the culture medium minimized the degree of proteolysis. Two major species of chimera, 85 and 65 kDa, were then isolated from the culture medium. The former was the intact form consisting of a single-chain and showing full enzyme activity after activation by plasmin. The latter was an enzymatically processed form consisting of two chains held by a disulfide bond, having full enzyme activity without activation. Both chimeras exhibited calcium-dependent phospholipid (PL)-binding affinities similar to the parent AV.

Amino Acid Sequence↗