Multi-point density measurement of a collisional merging formation process of FRCs.

Collisional merging formation of field-reversed configuration (FRC) plasmas at supersonic velocities was performed using the FRC amplification via translation-collisional merging device. Supersonic collisional merging formation is a novel technique to form an FRC that is long-lived compared to a conventional initial formation FRC; however, this technique requires measuring the plasma parameters at multiple points simultaneously because of the dynamic translation/merging process. Herein, we have developed a new interferometer and have observed the dynamic behavior of FRCs in the formation, translation, and merging processes simultaneously. In this study, as one of the performance evaluations of the developed simultaneous density measurement, collision/merging of FRCs have been conducted in the confinement section with and without background neutral gas. Comparing translation into deuterium gas vs translation into a vacuum environment prior to the collisional merging, we found that the background neutral particles were trapped in the merged FRC; moreover, a difference in the decay rate of the stored internal energy was observed.

Spatiotemporal expression patterns of doublesex and mab-3 related transcription factor 1 in the chicken developing gonads and Mullerian ducts.

Sex of birds is genetically determined by the inheritance of sex chromosomes (ZZ for male and ZW for female), and the Z-linked gene named doublesex and mab-3 related transcription factor 1 (DMRT1) is a candidate sex-determining gene in avian species. However, the mechanisms underlying sex determination in birds are not yet understood, and the expression patterns of the DMRT1 protein in urogenital tissues have not been identified. In the current study, we used immunohistochemistry to investigate the detailed expression patterns of the DMRT1 protein in the urogenital systems (including Müllerian ducts) in male and female chicken embryos throughout embryonic development. Gonadal somatic cells in the male indifferent gonads showed stronger expressions of DMRT1 compared with those in the female indifferent gonads well before the presumptive period of the sex determination, and Sertoli cells forming testicular cords expressed DMRT1 in the testes after sex determination. Germ cells expressed DMRT1 equally in males and females after sex determination. The expression was continuous in males, but in females it gradually disappeared from the germ cells in the central part of the cortex of the left ovary toward both edges. The DMRT1 was also detected in the tubal ridge, which is a precursor of the Müllerian duct, and at the mesenchyme and outermost coelomic epithelium of the Müllerian duct in both sexes. Strong expression was observed in the males, but it was restricted to coelomic epithelium after the regression of the duct started. Thus, we observed the detailed spatiotemporal expression patterns of DMRT1 in the developing chicken urogenital systems throughout embryonic development, suggesting its various roles in the development of urogenital tissues in the chicken embryo.

Metastatic thyroid cancer manifesting as a mediastinal mass in a man with an aberrant right subclavian artery.

We treated a case of thyroid cancer manifesting as a mediastinal mass, completely resecting it without difficulty despite a vascular anomaly. An asymptomatic 42-year-old woman was admitted with a mediastinal mass. Ten years earlier, she had undergone surgery for a thyroid tumor diagnosed as follicular adenoma. She also had an aberrent subclavian artery anomaly with a non-recurrent laryngeal nerve, radiographically recognized preoperatively. The mediastinal mass was completely resected through median sternotomy. Pathological examination showed the previous thyroid tumor had been follicular carcinoma, and that the mass was a mediastinal-node metastasis from the thyroid cancer. Preoperative recognition of the vascular anomaly was helpful in completing resection, in addition to safe, quick surgical procedures.

Successful treatment of mucoepidermoid carcinoma of the carina.

We successfully treated a 33-year-old man with mucoepidermoid carcinoma at the carina. Through preoperative spiral computed tomography with multiplanar and three-dimensional reconstructions, the lesion extended along the right main bronchus across the orifice of the right upper lobe. He underwent a carinal resection plus right upper lobectomy and reconstruction of the carina. He shows neither anastomotic complication nor recurrence of disease 1 year after surgery. Spiral computed tomography was used to evaluate the preoperative and postoperative state of the central airway.

Combined choriocarcinoma and adenocarcinoma of the lung occurring in a man: case report and review of the literature.

BACKGROUND: Human chorionic gonadotropin (hCG)-producing large or giant cell carcinoma of the lung is not uncommon, but primary pulmonary choriocarcinoma is an extremely rare entity. Even rarer are cases occurring in males; to date the authors have found only 12 reported cases in the English literature. METHODS: The clinical record of a 61-year-old man who presented with hemoptysis is described. A review of the literature regarding patients with primary pulmonary choriocarcinoma also is reported. RESULTS: Computed tomography scan of the chest demonstrated an expanding thickness of the bullous wall within areas of emphysematous change in the lower lobe of the right lung. Moreover, a new, round tumor near the thickness appeared and rapidly expanded evenly into the surrounding lung tissue. Exploratory thoracotomy revealed the previous tumor to be adenocarcinoma with a small foci of choriocarcinoma, and the new tumor to be a hemorrhage with choriocarcinoma. Because of the pleural dissemination, the patient was treated with chemotherapy. At last follow-up he was alive and well with a gradually increasing serum hCG-beta level in spite of chemotherapy. CONCLUSIONS: Primary pulmonary choriocarcinoma occurring in men is an extremely rare entity with a fatal prognosis. Of the 12 cases reported to date in the English literature, 3 cases of choriocarcinoma with the coexistence of another type of pulmonary carcinoma were reported. To the authors' knowledge the clinical relation between these two types of carcinoma are unknown because all cases to date have been detected at the time of autopsy. Only in the current study case could the clinical course of the disease be followed and pathologic confirmation achieved, although the pathogenesis of the two types of carcinoma could not be determined.

Bioabsorbable poly-L-lactide costal coaptation pins and their clinical application in thoracotomy.

BACKGROUND: To gain a wider operation field, ribs often are fractured as the intercostal retractor is expanded. Thoracotomy through the periosteal bed and other procedures have been performed to prevent rib fractures, and rib resections occasionally have been required. METHODS: We designed a poly-L-lactide costal coaptation pin. We used this pin in 184 thoracotomies and carried out long-term observation after insertion to evaluate its clinical efficacy and safety. Postoperative observation periods ranged from 1 to 58 months (mean +/-standard error, 21.6+/-1.2 months). We evaluated the costal pin according to its degree of fixation, categorizing it as "good," "fair," or "poor" in this respect. We also judged its lateral shift. RESULTS: We judged fixation as "good" in 130 cases (70.7%), and found no lateral shift in 103 cases (56%). Our overall evaluation indicated satisfactory results in 172 cases (93.5%). CONCLUSIONS: Rib fixation was secured in nearly all cases, and no side effects were encountered. We can confirm that the poly-L-lactide costal coaptation pin is a highly effective and safe device.

[Four cases of cancer of unknown primary site that manifested as mediastinal metastatic lesions].

We encountered 4 patients with cancers of unknown primary sites that were manifested by mediastinal lesions. Patient 1 was a 58-year-old man with enlarged superior mediastinal lymph nodes. An exploratory thoracotomy yielded a diagnosis of lymph node metastasis of poorly differentiated adenocarcinoma. The patient was treated with chemotherapy and radiation therapy. Patient 2 was a 68-year-old man with a tumor in the right superior mediastinum. A total resection of the tumor was performed through a thoracotomy. The diagnosis was lymph node metastasis of squamous cell carcinoma, and treatment consisted of irradiation. A tumor shadow in the right upper lobe appeared 14 months after the thoracotomy, and was considered to be a primary lesion requiring a right pneumonectomy. The patient died of hepatic metastasis 6 months after the second operation. Patient 3 was a 59-year-old man with mediastinal and hilar lymph node swelling. Mediastinoscopic findings resulted in a diagnosis of squamous cell carcinoma. Because of the patient's insistence, only radiation therapy was performed. Patient 4 was a 65-year-old woman with a tumor in the right superior mediastinum who underwent a median sternotomy for total resection of the tumor. The pathological findings were strongly suggestive of metastasis of clear cell carcinoma. Patients 1, 3, and 4 were alive 33, 24, and 51 months, respectively, after their initial operation, without detectable primary sites. Patient 2 was considered to have had T 0 N 2 lung cancer.

Carcinosarcoma of the lung mis-diagnosed preoperatively as a mediastinal tumor.

Carcinosarcoma of the lung is an uncommon tumor and is rarely preoperatively correctly diagnosed. The prognosis of patients with carcinosarcoma is extremely poor, despite treatment. A 79-year-old man was mis-diagnosed preoperatively as having a malignant mediastinal tumor. Excision of the tumor with segmentectomy of the lung revealed it was composed of a variety of carcinomatous and sarcomatous elements, which is a clear manifestation of the histogenetic totipotentiality of carcinosarcoma. He was subsequently treated with adjuvant chemotherapy and irradiation. He remains well at sixteen months after the operation, to date. Here we report this rare true case of a carcinosarcoma, focusing on the difficulty of a correct preoperative diagnosis.

[A case of tuberculous granulomatous mediastinitis and constrictive pericarditis simulating malignant mediastinal tumor].

A case is 40-year-old man. He presented anterior chest pain. Pericardial effusion was pointed out and a tuberculin skin test was positive. Tuberculous pericarditis was highly suspected, so INH and RFP were medicated. After 6-month medication pericardial effusion decreased, but right pleural effusion appeared on chest X-ray. Chest CT revealed a thickening of pericardium extend to anterior mediastinal mass. Echocardiogram revealed a pressure gradient in right ventricle, which was compressed by the thickened pericardium. We underwent median sternotomy in order to rule out neoplastic diseases. Intraoperative pathologic diagnosis was granulomatous mediastinitis and pericarditis, so we resected granuloma as much as possible to decompress the heart. Although Mycobacterium tuberculosis was not found in the resected granuloma, it was most probable pathogen. He received additional antituberculous chemotherapy for 6 months.

[Three cases of postoperative laryngopharyngeal edema following nonsimultaneous bilateral radical neck dissection].

Three cases of postoperative laryngopharyngeal edema following nonsimultaneous radical neck dissection are presented. Case 1 was a 65-year-old male with tongue cancer and left cervical lymph node metastases. Hemiglossectomy, reconstruction of the floor of the mouth with a free rectus abdominis flap, and left radical neck dissection had been performed. Postoperatively, the tongue and left upper neck were irradiated. Seven months later, right cervical lymph node metastases were observed. Right radical neck dissection was performed, and immediately after extubation, upper airway stenosis due to severe laryngopharyngeal edema occurred. Emergent tracheostomy saved his life. Case 2 was a 55-year-old female with tongue cancer and right cervical lymph node metastases. Radium needles had been implanted in the tongue, and right radical neck dissection was performed. Three months later, left cervical lymph node metastases were found. Left radical neck dissection was performed and, as in Case 1, upper airway stenosis revealed immediately after extubation. Since the situation was anticipated, an immediate tracheostomy was done. Case 3 was a 43-year-old male with laryngeal cancer and left cervical lymph node metastasis. Irradiation of the larynx and the bilateral upper neck followed by left radical neck dissection and partial laryngohypopharyngectomy had been performed. Five years later, right cervical lymph node metastasis was observed. Right radical neck dissection was performed, and laryngoscopic examination before extubation revealed severe laryngopharyngeal edema. In this case, tracheostomy was performed before extubation. To our knowledge, there have been only five cases of postoperative laryngopharyngeal edema, following nonsimultaneous radical neck dissection, reported in the literature.

[A case of traumatic intrapulmonary foreign body].

A case of 60-year-old man with traumatic intrapulmonary foreign body that was not inhaled, but through the chest wall was described. In July 1992 a grass cutter was working in a forestry with a circular saw when he was struck into the right lung. He had a sharp pain in the anterior chest. No abnormality was seen in front of his neck and the chest wall. The next month he developed a cough with bloody sputum. The chest X-ray showed a metallic foreign body at the right side of manubrium. Computed tomogram showed a steel wire fragment lodging beside the innominate artery and vein and in the right lung. Median sternotomy was performed and a foreign body was successfully removed with partial resection of upper lobe.

[Postoperative lung function in patients with funnel chest].

We evaluated the postoperative lung function determined by spirometry in 54 patients with funnel chest (48 males and 6 females: age range, 4-18 years). Thirty-one patients had sternal turnover as corrective surgery, while 23 had sternal elevation with absorbable PLA (polylactic acid) strut. The mean value of vital capacity as a percentage of predicted (%VC) was 97.3% before operation. %VC was decreased at 3 months (80.5%), 6 months (87.4%), 12 months (82.8%), 24 months (85.9%), and 36 months (77.7%) after the operation (p < 0.01). In patients who had sternal elevation, %VC was decreased at 3 months but not at 6 months, 12 months, 24 months, or 36 months after the operation, while %VC was decreased at any point after the operation in patients who had sternal turnover. No significant changes were seen in forced expiratory volume in one second as a percentage of predicted (FEV1.0%), nor in the ratio of residual volume to total lung capacity (RV/TLC). In conclusion, sternal elevation with PLA strut is a better corrective surgery for funnel chest than sternal turnover, because of its less lung function loss after the operation.

Aneurysm of coronary arteriovenous fistula presenting as a calcified mediastinal mass.

A 61-year-old woman with a giant aneurysm of the coronary arterial fistula between the left anterior descending coronary artery and the main pulmonary artery underwent aneurysmal resection and closure of the fistula. This was a very unusual case with rare congenital malformation with secondary atherosclerotic change.

[A case of so-called carcinosarcoma of the lung].

A 65-year-old male was admitted to our institute because of bloody sputum. A tumor in right S6 was detected by X-ray, CT and MRI. Bronchoscopic study showed that the right lower bronchus was occluded by the tumor, in which non-epithelial malignant cells were detected. Therefore right bilobectomy was performed. This tumor was a pedunculated endobronchial type measuring 6 x 4 x 3cm. Histologically, the tumor presented carcinomatous (squamous cell carcinoma and adenocarcinoma) and sarcomatous elements. Immunohistologically, many malignant cells were positively stained by vimentin and muscle-actin, which suggested differentiation from muscle components.

[A case of mediastinal liposarcoma].

Primary liposarcomas of the mediastinum are rare neoplasms comprising only 0.13-0.75% of mediastinal tumors. We report a case of liposarcoma arising in the right posterior mediastinum. A 74-year-old man without symptoms was admitted to our hospital for evaluation of an abnormal shadow on chest roentgenogram. Computed tomogram (CT) and magnetic resonance (MR) imaging revealed a mediastinal tumor. The tumor was surgically removed, and the diagnosis of well-differentiated liposarcoma was established. MR imaging was superior to CT in evaluation of tumor extent, but not in differential diagnosis as liposarcoma or lipoma.

Paraganglioma of the posterior mediastinum: value of magnetic resonance imaging.

A case of paraganglioma arising in the posterior mediastinum in a 29-year-old man diagnosed by magnetic resonance imaging is reported. Excision of mediastinal paraganglioma is often hazardous because of its rich vascular supply and tendency to involve surrounding structures. Magnetic resonance imaging is valuable for the preoperative diagnosis of this vascular tumor as well as for determination of its resectability and appropriate surgical procedure.

[Poly-lactic-acid (PLA) sternal pins for the closure of median sternotomy--report of a case].

Poly-lactic-acid (PLA) sternal pins were used for the closure of median sternotomy in a case of bilateral pneumothorax. After placement 7 sutures of polyester and 2 wires, PLA sternal pins were inserted into the bone marrow of the sternum. The wires were then twisted and tightened, and all sutures were tightened, and the wires were removed. No significant postoperative complications, i.e., osteomyelitis and mediastinitis, sternal dehiscence, or bone marrow dysfunction, were observed. In addition, the PLA sternal pins were absorbed. In the closure of median sternotomy, PLA sternal pins provide stable sternal adhesion, which is essential to the prevention of sternal dehiscence and other complications. Moreover, with the use of PLA sternal pins, the retention of steel wires in the body is unnecessary.

[Role of surgical treatment in thoracic empyema with bronchopleural and/or thoracic empyema].

Sixty-nine patients with thoracic empyema treated surgically were experienced from May, 1978 through December, 1990. Thirty-nine cases had bronchopleural and/or thoracic fistula. Thirty-two patients were associated with pulmonary tuberculosis, of whom fourteen had tuberculous empyema and eighteen were sequelae of pulmonary tuberculosis or tuberculous pleurisy. The remainder were postoperative, postpneumonic, and posttraumatic empyemas. Of fourteen patients who developed postoperative bronchopleural fistula, there were ten patients who had lobectomy or pneumonectomy for lung cancers. Omental pedicle flap method, in which empyema space was filled with the omentum and pedicled muscle flap, was performed on 19 patients with bronchopleural or thoracic fistula or both. Fifteen patients were cured successfully by single-stage procedure, though there was one operative death due to aspiration pneumonia, and two recurrences which were treated by muscle plombages. There was another patient who had multiple surgical procedures in the past resulting in partial recurrences, but the fistula of this patient subsequently closed without reoperation. Postoperative decrease of %VC, FEV1.0/PVC were minimal. Treatment of long standing bronchopleural fistula is a difficult problem, and our omental pedicle flap method is relatively simple and safe which can be most suitably applied to those patients in whom other procedures have failed and to those with poor pulmonary functions.