Self-Regeneration Process of Ni-Cu Alloy Catalysts during a Three-Way Catalytic Reaction-An Operando Study

It is important to understand the reduction processes of mixed metal oxides or metal oxide interfaces in three-way catalytic reactions toward replacing the currently used high-cost Pt group metal catalysts. The redox behavior of simple Ni-Cu alloy catalysts, which exhibit high catalytic activity and durability during a three-way catalytic reaction, was studied by operando X-ray absorption spectroscopy (XAS). The operando XAS analyses revealed that Ni-Cu species changed from the NiO-Cu₂O to Ni-Cu alloy and vice versa under reductive and oxidative conditions, respectively. The real-time monitoring of the oxidation states of Ni and Cu species indicated that the Cu species assisted the reduction of Ni species, in agreement with the density functional theory-based study of NiO reduction by carbon monoxide in the presence of metallic Cu nanoparticles.

Clinical risk predictors for bradycardia, supraventricular tachycardia and epilepsy necessitating therapy in patients with unexplained syncope monitored by insertable cardiac monitor

Background

Insertable cardiac monitors (ICMs) allow for lengthy monitoring of cardiac rhythm and improve diagnostic yield in patients with unexplained syncope. In most cardiac syncope cases, sick sinus syndrome, atrioventricular block, and paroxysmal supraventricular tachycardia (SVT) are detected using ICMs. On the other hand, epileptic seizures are sometimes diagnosed as unexplained syncope because in these situations, the loss of consciousness is a similar manifestation. Thus, the population of patients with unexplained syncope monitored by ICMs includes epileptic patients. Clinical risk factors for bradycardia, SVT and epilepsy that necessitate therapy in patients with unexplained syncope are not well known. If these risks can be clarified, clinicians could provide more specific targeted monitoring.

Purpose

We aimed to identify these predictors.

Methods

We retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope in three medical facilities. We performed Cox's stepwise logistic regression analysis to identify significant independent risk factors for bradycardia, SVT, and epilepsy.

Results

One hundred thirty-two patients received ICMs to monitor unexplained syncope. During the 17-month follow-up period, 19 patients (10 patients had sick sinus syndrome and 9 had atrioventricular block) needed pacemaker for bradycardia; 8 patients (3 had atrial flutter, 4 had atrial tachycardia, and 1 had paroxysmal atrial fibrillation) needed catheter ablation for SVT; and 9 patients needed antiepileptic agents from the neurologist.Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p=0.02) was an independent risk factor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p=0.008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p=0.006) were identified as significant independent prognostic factors for SVT. Syncope while supine (OR = 11.7; 95% CI, 1.72 to 79.7; p=0.01) or driving (OR = 15.6; 95% CI, 2.10 to 115.3; p=0.007) was an independent factor for epileptic seizure.

Conclusions

ICMs are useful devices for diagnosing unexplained syncope. Palpitation, atrial fibrillation and syncope during effort were independent risk factors for bradycardia and for SVT. Syncope while supine or driving was an independent risk factor for epilepsy. We should carefully follow up of patients with these risk factors.

Funding Acknowledgement

Type of funding source: None

P5697J-wave elevation in the inferior leads is a predictor of lethal ventricular arrhythmia initiated by premature ventricular contractions with right bundle branch block and superior axis

Background

Lethal-ventricular-arrhythmia (VA) could be sometimes initiated by idiopathic Premature Ventricular Contractions (PVCs) originated form inferior wall. Furthermore, J-wave elevation in inferior leads was sometimes associated with lethal-VA. However, it was unclear the relationship between these PVCs and J-wave elevation in patients with lethal-VA.

Purpose

The aim of this study was to investigate the relationship between PVCs and J-wave elevation.

Methods and results

We studied 32 patients who underwent radiofrequency (RF) ablation of idiopathic PVCs with RBBB and superior axis. These PVCs were originating from inferior wall of left ventricular. Lethal-VA was defined as ventricular fibrillation (VF) or ventricular tachycardia (VT) with loss of consciousness (LOC). Among 32 patients, 3 had VF and 2 had VT with LOC. Other 27 had non-lethal-VA. Baseline clinical characteristics were not significantly difference between lethal and non-lethal-VA. The ratio of J-wave elevation in lethal-VA was significant higher as compared to those with non-lethal-VA (5/5 (100%) vs. 3/27 (11.1%), p<0.0001). Furthermore, no patients had recurrence of lethal-VA with J wave elevation in inferior leads after RF ablation of these PVCs with RBBB and superior axis,

Conclusions

We speculated that J-wave elevation in inferior leads might be a predictor of lethal-VA initiated by PVCs with RBBB and superior axis. RF ablation of these PVCs were useful method of treating lethal-VA.

Acknowledgement/Funding

None

Self-regeneration of a Ni-Cu alloy catalyst during a three-way catalytic reaction

Ni-Cu alloy supported on γ-Al2O3 catalysts prepared by high-temperature hydrogen reduction exhibit high catalytic activity and durability for a three-way catalytic reaction under both oxidative and reductive conditions because of their self-regenerating feature. DFT calculations showed that Ni-oxide was reduced to Ni metal by CO in the presence of Cu metal because of the Ni-Cu alloy effect but was not in the absence of Cu metal.

Identification of a chemical modulator of EZH2-mediated silencing by cell-based high-throughput screening assay

Dysregulation of enhancer of zeste homologue 2 (EZH2), a methyltransferase component of polycomb repressive complex 2, is found in many types of cancers especially those that are highly progressive and aggressive. Specific catalytic inhibitors of EZH2 have high anti-tumour activity, particularly in lymphomas with EZH2 activating mutations. However, the clinical benefits of EZH2 catalytic inhibitors in tumours overexpressing EZH2 are still limited. Here, we identified NPD13668, a novel modulator of EZH2-mediated gene silencing, from 329,049 small chemical compounds using a cell-based high-throughput screening assay. NPD13668 reactivated the expression of silenced H3K27me3 target genes together with depletion of the H3K27me3 modification. In addition, NPD13668 repressed the cell growth of prostate cancer cell lines (PC3 and LNCaP) and ovarian cancer cell lines (SKOV3 and NIH-OVCAR3). NPD13668 partially inhibited the methyltransferase activity of EZH2 in vitro. Genome-wide expression analysis revealed that after NPD13668 treatment, about half of the upregulated genes overlapped with genes upregulated after treatment with GSK126, well-known EZH2 catalytic inhibitor, indicating that NPD13668 is a potential modulator of EZH2 methyltransferase activity. Our data demonstrated that targeting the pharmacological inhibition of EZH2 activity by NPD13668 might be a novel cancer treatment.

Screening and identification of a non-peptide antagonist for the peptide hormone receptor in Arabidopsis

Intercellular signaling mediated by peptide hormones and membrane-localized receptor kinases plays crucial roles in plant developmental processes. Because of their diverse functions, agonistic or antagonistic modulation of peptide signaling holds enormous promise for agricultural applications. Here we established a high-throughput screening system using a bead-immobilized receptor kinase and fluorescent-labeled peptide ligand to identify small molecules that bind peptide hormone receptors in competition with natural ligands. We used the Arabidopsis CLE9-BAM1 ligand-receptor pair to screen a library of ≈30,000 chemicals and identified NPD12704 as an antagonist for BAM1. NPD12704 also inhibited CLV3 binding to BAM1 but only minimally interfered with CLV3 binding to CLV1, the closest homolog of BAM1, demonstrating preferential receptor specificity. Treatment of clv1-101 mutant seedlings with NPD12704 enhanced the enlarged shoot apical meristem phenotype. Our results provide a technological framework enabling high-throughput identification of small non-peptide chemicals that specifically control receptor kinase–mediated peptide hormone signaling in plants.

Hidefumi Shinohara and colleagues used the CLE9-BAM1 ligand-receptor pair as a model system for screening peptide hormone receptor-binding small molecules in plants. They identified the small molecule NPD12704 as an antagonist for BAM1 and demonstrated the specific regulatory activity of NPD12704 in shoot apical meristem.

Induced cortical tension restores functional junctions in adhesion-defective carcinoma cells

Normal epithelial cells are stably connected to each other via the apical junctional complex (AJC). AJCs, however, tend to be disrupted during tumor progression, and this process is implicated in cancer dissemination. Here, using colon carcinoma cells that fail to form AJCs, we investigated molecular defects behind this failure through a search for chemical compounds that could restore AJCs, and found that microtubule-polymerization inhibitors (MTIs) were effective. MTIs activated GEF-H1/RhoA signaling, causing actomyosin contraction at the apical cortex. This contraction transmitted force to the cadherin-catenin complex, resulting in a mechanosensitive recruitment of vinculin to cell junctions. This process, in turn, recruited PDZ-RhoGEF to the junctions, leading to the RhoA/ROCK/LIM kinase/cofilin-dependent stabilization of the junctions. RhoGAP depletion mimicked these MTI-mediated processes. Cells that normally organize AJCs did not show such MTI/RhoA sensitivity. Thus, advanced carcinoma cells require elevated RhoA activity for establishing robust junctions, which triggers tension-sensitive reorganization of actin/adhesion regulators.

[Video-assisted thoracic surgery for pneumothorax in patients over fifty years of age]

BACKGROUND

Pneumothorax in middle-aged and elderly patients has various different features from young patients. We set out to investigate the outcome and usefulness of video-assisted thoracic surgery (VATS) in this group.

PATIENTS AND METHODS

From January 1993 to August 2010, 168 patients underwent a total of 178 thoracoscopic surgeries. There were 160 men and 8 women with mean age of 67 (range, 50 to 85). The average duration of thoracic drainage before surgery was 7.4 days. We excised only responsible lesions as minimum degree of dissection as possible. When patients have intractable air leakage and chest computed tomography (CT) indicates severe pleural adhesions, pleurography should be performed to locate the site of air leakage and determine surgical approaches. One hundred and seventy patients were treated with the lateral approach, while 8 patients were successfully treated with the anterior approach. One hundred and fifty-one patients were treated with VATS alone, and 27 patients were treated with the combination of VATS and small thoracotomy. The duration of chest tube drainage, hospital stay, post-operative complication, outcome and recurrence were assessed.

RESULTS

The air leakages stopped and all patients except for 2 patents were discharged without drainage tubes. Postoperative drainage time was 4.5 +/- 3.4 days. Postoperative hospital stay was 9.9 +/- 13.9 days. One patient died caused by perioperative myocardial infarction. Seventeen patients died of other diseases. Seven patients needed local hospital treatments and the recurrence rate was 3.9%.

CONCLUSION

VATS for pneumothorax in patients over 50 years old is very useful by appropriate perioperative managements.

Precise control of nanofabrication by atomic force microscopy

With an aim of the precise control of the anodic oxidation process by atomic force microscopy, the technical improvement has been carried out based on the mechanism studies. The accuracy and reliability of the nanofabrication have been improved by the combination of ambient humidity control, improvement of instrumental performance and meniscus lifetime control. In parallel, the mechanism study has been proceeded through the detection of Faradaic current. The in situ Faradaic current detection of the nano-oxidation process can actually work as a sensitive monitor for the nano-oxidation process with a high reliability. From an engineering viewpoint with an eye to practical applications, controllable physical parameters which affect on the product size are enumerated to consider what we should do to raise the precision of nano-oxidation. Then the fast fabrication in a large area by a patchwork method, Faradaic current detection during oxidation-reduction reaction, and nanofabrication by current-control are shown as examples.

[Surgically treated chest wall schwannoma without entering the pleural space utilizing ultrasonography]

We report a case of surgically treated chest wall schwannoma without entering the pleural space utilizing ultrasonography. A 19-year-old woman was admitted for an abnormal shadow on a routine health checkup. Roentgenologic examination of the chest showed a 2 cm left chest wall mass. Chest computed tomography revealed a heterogeneous mass with obtuse angles characteristic of a pleural-based lesion. Under general anesthesia, the patient was placed in the right decubitous position. Chest wall ultrasonography defined a mass in the intercostal space. A 2.5 cm skin incision was made on the tumor. The tumor arising from the intercostal nerve was surgically removed without entering the pleural space. The pathological examination revealed a benign schwannoma. Postoperative course was uneventful and she discharged 2 days later. Six years later the patient is well without recurrence.

[New forceps for a sutureless patch technique using sheet materials]

Intraoperative air leaks are often treated by a sutureless patch technique using a fibrin tissue-adhesive collagen fleece or synthetic materials with fibrin sealant. Intraoperatively, the technique of using these materials has been troublesome, therefore air leaks fail to close. Akicette has been applied as an easy sutureless patch technique for air leaks. Seven air leaks (5 were lung cancers, 2 were spontaneous pneumothorax) were treated with Akicette. Akicette is simple to operate with, and can easily carry sheet materials. Using Akicette, the sheet materials tightly adhered onto surrounding the pleural defect without any sliding on the wet lung surface. Akicette is feasible tool for a sutureless patch technique and is useful to easily place the sheet materials.

[Simulation of lung lobe resection with personal computer]

Various patterns of branching are seen for pulmonary arteries and veins in the lung hilum. However, thoracic surgeons usually cannot expect to discern much anatomical detail preoperatively. If the surgeon can gain an understanding of individual patterns preoperatively, the risks inherent in exposing the pulmonary vessels in the hilum can be avoided, reducing invasiveness. This software will meet the increasing needs of them in video-assisted thoracoscopic surgery (VATS) which prefer lesser dissections of the vessels and bronchus of hilum. We have produced free application software, where we can mark on pulmonary arteries, vein, bronchus and tumor of the successive images of computed tomography (CT). After receiving a compact disk containing 60 images of 2 mm CT slices, from tumor to hilum, in DICOM format, we required only 1 hour to obtain 3-dimensional images for a patient with other free software (Metasequoia LE). Furthermore, with Metasequoia LE, we can simulate cut the vessels and change the figure of them 3-dimensionally. Although the picture image leaves much room for improvement, we believe it is very attractive for residents because they can simulate operations.

[Inadvertent coil migration that required urgent thoracotomy during embolization for the treatment of pulmonary arteriovenous fistula]

A 70-year-old woman was referred to our department because of a solitary nodular shadow, 2 cm in diameter, in the right mid zone on a chest X-ray. Chest computed tomography revealed a pulmonary arteriovenous fistula (PAVF) in S4 of the right lung. Although the patient did not present with PAVF-related symptoms or hypoxemia, in view of the threat of serious complications, a therapeutic decision was made for coil embolization of the pulmonary artery feeding the PAVF. During the endovascular embolization procedure, the coil migrated into the mitral valve chordae tendinae. Urgent thoracotomy was therefore performed and the coil was safely retrieved from the site. Via the same thoracotomy incision, the PAVF with its surrounding tissue was also resected from the right lobe of the lung. The inadvertent coil migration in this patient may be explained by the fact that the fistula was not large enough to allow the coil to stay in place for the prevention of blood flow from the feeding vessel. These findings indicate that surgical resection of PAVF should be selected when the size of the fistula is too small for coil embolization. Otherwise, if transcatheter embolization is preferred, the detachable balloon approach may be appropriate.

[Squamous cell carcinoma caused by dysplasia on the bullous wall]

We experienced a squamous cell lung carcinoma caused by dysplasia around the bullous wall after right upper lobectomy by tuberculosis. A case is 70 years old male who was resected right upper lobe caused by tuberculosis 50 years ago. He was pointed out an abnormal shadow on the chest X-ray in March 2002. There were bullous change in right lung field on the chest computed tomography (CT). There was appeared a tumor contiguous to the bullous wall. A part of bullous wall surrounding the tumor was thickened bronchio-alveolar lavage gave proof of squamous cell carcinoma. Right basal segmentectomy and subcarinal lymph node dissection was done, because of severe adhesion a right middle lobe. Radiation therapy at the mediastinum is performed, because of positive subcarinal lymph nodes. It is rare case of squamous cell carcinoma caused by dysplasia, we reported.

[Stenting in obstruction of superior vena cava; clinical experience with the self-expanding endovascular prosthesis]

From August 1997 to December 2002, 14 consecutive patients with superior vena cava syndrome with the self-expanding endovascular prosthesis. Diagnoses were adenocarcinoma in 6, small cell carcinoma in 4, squamous cell carcinoma in 1, metastatic lung cancer in 2, and invasive thymoma in 1. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured on their admission and perioperative period. Expecting only 1 patient complete symptomatically relieved within 3 days of stent implantation. Superior vena cava pressure or radial pressure of the stent was sufficient to relieve obstruction. Preoperative ANP level were normal, BNP level were increased. Postoperatively both ANP level and BNP level were slightly increased under intravenous dopamine hydrochloride. Implantation of the self-expanding stent endovascular prosthesis for superior vena cava syndrome provides rapid symptomatic relief and improves the patient's quality of life.

[Clinical study on video-assisted thoracic surgical simultaneously stapled subsegmentectomy for peripheral lung tumors]

BACKGROUND

The purpose of this study is to confirm the safety and validity of video-assisted thoracic surgical simultaneously stapled subsegmentectomy (simultaneously stapling of all subsegmental bronchi and vessels in their natural construction).

METHODS

The clinicopathologic information of the 10 patients who underwent video-assisted thoracic surgical simultaneously stapled subsegmentectomy for primary lung cancer (6) and metastatic lung tumor (4) were reviewed retrospectively. The patient population consisted of 7 men and 3 women with a mean age of 70.2 years.

RESULTS

Median operative time was 201 minutes. Average blood loss was 76 ml. Mean duration of thoracic drainage was 3 days. There was no surgical mortality. Recurrence was diagnosed in 2 of 6 lung cancer patients (each of contralateral lung metastasis and brain metastasis), and 1 of 2 died 26 months after the operation. All patients have been followed for a mean period of 30.4 months with no local recurrence.

CONCLUSIONS

Video-assisted thoracic surgical simultaneously stapled subsegmentectomy is safe and may be an acceptable alternative to segmentectomy, and wedge resection for strictly selective patients with peripheral lung tumors.

Propagation of surface plasmon polariton in nanometre-sized metal-clad optical waveguides

Using a local anodic-oxidation method with a probe tip of a scanning near-field optical microscope (SNOM) as the electrode, we have fabricated an oxide core with subwavelength dimensions on metal. The propagation of the surface plasmon polariton (SPP), which is excited at the interface between the oxide core and the metal clad, has been investigated using the same SNOM. Altering the wavelength of input light from 532 nm to 830 nm, the propagation length of the SPP extends from 2 micro m to 6 micro m. We carried out a simulation of the SPP propagation, and obtained a similar wavelength dependence.

Near-field observation of carrier diffusion in GaAs quantum structures under high magnetic fields

Photoluminescence from a two-dimensional electron-gas system in GaAs single hetero-structures was investigated using a scanning near-field optical microscope (SNOM) operated at cryogenic temperatures under high magnetic fields. The local intensity of the luminescence increased 600-fold that at 0 T as the magnetic field was increased up to 6 T. The enhancement depended on the spatial resolution of the SNOM. These characteristics are explained by the suppression of the diffusion of photocarriers caused by the Lorentz force in magnetic fields.

[Video-assisted thoracic surgery for the resection of pulmonary metastases]

We report the use of video-assisted thoracic surgery (VATS) as a treatment or pulmonary metastases. Between July 1994 and March 2002, 75 patients were treated for metastatic lung tumor by VATS. These patients included 45 males and 30 females with an average age of 60.6 years. Their primary diseases were Colon cancer (38), renal cell carcinoma (12), breast cancer (6), seminoma (3), thyroid carcinoma (3), parotid cancer (2), pharyngeal cancer (2) and the others (9). Tumor size ranged from 6 to 62 mm in diameter. A preoperative high resolution spiral computed tomography (CT) scan was used to locate the nodule in all patients. Ten recurrence cases were performed re-resection by VATS approach with an average period was 22 month. We conclude that VATS is a good candidate for the resection of lung metastases in the selected cases.

[Surgical management of acute empyema]

Basic principles apply to the management of all forms of acute empyema: investigation and treatment of the underlying infection, drainage of purulent collection, obliteration of the space, and treatment of the associated intercurrent medical conditions. From July 1999 to May 2001, we performed surgical treatment in 11 patients for acute empyema. There were 4 cases of the fibrinopurulent phase and 7 cases of the organizing phase. Surgical procedure was 7 open thoracotomies and 4 thoracoscopies. The mean operating time was 154.2 +/- 36.6 minutes and blood loss during surgery was 344.7 +/- 274.8 ml. There was no procedure-related morbidity. In conclusion, early aggressive surgical approach is a feasible method for treatment of acute empyema.

[Total aortic arch replacement for distal aortic arch aneurysm with adhered left lung: report of a case]

A 76-year-old man with a history of pleuritis and a cerebral infarct underwent a total arch replacement for an aneurysm of the distal aortic arch. Computed tomography revealed a true aneurysm having a maximum diameter of 70 mm as well as pleural thickening and calcification. Total arch replacement with selective cerebral perfusion was performed through median sternotomy and left thoracotomy. The myocardial ischemic time was shortened by reperfusion from the right axillary artery after the anastomosis of the proximal ascending aorta and the brachiocephalic artery. After the other branches of the arch were anastomosed, a distal anastomosis through the left thoracotomy was then performed using the pull-through method, enabling minimal decortication of the adhered lung. Our surgical procedure for distal arch aneurysm with adhered lung involves the addition of a left thoracotomy, but the reduction in the myocardial ischemic time and lung injury are of benefit.

Thoracoscopic surgery for pneumothorax in older patients

BACKGROUND

Secondary pneumothorax is more common in older pneumothorax patients. Therefore, we set out to investigate the usefulness of thoracoscopic surgery in this group.

METHODS

A total of 59 operations were performed on patients aged > or = 50 years, with the goal of excising only the lesions responsible for air leaks by using the minimum degree of dissection. If the patients were found to have numerous bullae, the lesions responsible were identified by pleurography. The duration of chest tube drainage, hospital stay, and recurrence were assessed.

RESULTS

The air leaks stopped and all patients were discharged without drains. Postoperative drainage time was 3.8 +/- 3.0 days. Postoperative hospital stay was 10.8 +/- 9.2 days. Six patients died of other diseases, but there was only one recurrence of pneumothorax.

CONCLUSION

We consider video-assisted thoracic surgery (VATS), with the goal of excising only the lesions responsible for air leaks, to be particularly efficacious in older pneumothorax patients.

Measurement of antiacetylcholine receptor antibody in patients with thymoma without myasthenia gravis complications

OBJECTIVE

Some patients with thymoma reported to show higher antiacetylcholine receptor antibody titers without the preoperative occurrence of myasthenia gravis and some have suffered postoperative complications of myasthenia gravis despite being negative for antiacetylcholine receptor antibody preoperatively. We evaluated changes in antiacetylcholine receptor antibody titers and the occurrence of myasthenia gravis in thymoma patients.

METHODS

Subjects were 31 of 44 patients with thymoma undergoing thymothymectomy at Tokyo Women's Medical University Hospital between 1987 to 1999 in whom antiacetylcholine receptor antibody titers were measured preoperatively. We studied postoperative changes in antiacetylcholine receptor antibody titers and the presence or absence of myasthenia gravis.

RESULTS

Eight patients were positive for antiacetylcholine receptor antibody preoperatively, suggesting the presence of subclinical myasthenia gravis. Neither postoperative changes in antiacetylcholine receptor antibody titers nor the occurrence of myasthenia gravis was observed in these 8 patients. Recurrent thymoma and rapid elevation of antiacetylcholine receptor antibody titers were observed postoperatively in 1 patient negative for antiacetylcholine receptor antibody preoperatively, resulting in manifestation of myasthenia gravis symptoms.

CONCLUSION

We found no correlation between preoperative titers and myasthenia gravis symptoms. Rapid titer elevation indicates the occurrence of myasthenia gravis symptoms or the recurrence of thymoma.

The role of video-assisted thoracoscopic surgery in the diagnosis of the small peripheral pulmonary nodule

BACKGROUND

The use of imaging techniques to detect small peripheral pulmonary nodules often results in a missed diagnosis. Thoracoscopy had limited application until recently, when advances in technology allowed thoracic surgeons greater visualization and mobility within the chest.

METHODS

Between September 1992 and June 1997, 81 patients were treated for small peripheral pulmonary nodules by pulmonary wedge excision using video-assisted thoracoscopic techniques. The patients were 39 men and 42 women with an average age of 59.5 years.

RESULTS

A definitive diagnosis was obtained in all cases. Malignancies were found in 44 patients (55%), which involved primary lung cancer in 28 patients and metastatic lesions in 16 patients. The rate of malignancy in nodules measuring 1 cm or less was 18%. There was no operative mortality or morbidity.

CONCLUSIONS

We conclude that video-assisted thoracoscopic lung biopsy is a more effective and less invasive diagnostic tool for small peripheral pulmonary nodules.

Bullectomy is beneficial in the pulmonary blood flow/driving pressure relationship in bullous emphysema patients

OBJECTIVES

Few physiological studies have been on pulmonary circulation, including the relationship between pulmonary blood flow and driving pressure, and viscosity changes arising from hematocrit changes before versus after lung volume reduction Surgery or bullectomy in emphysematous patients.

METHODS

We studied the relationship between pulmonary blood flow and driving pressure before and after bullectomy using a unilateral pulmonary artery occlusion test based on pulmonary blood flow fractions obtained by pulmonary blood flow scintigraphy in 7 patients with pulmonary emphysema associated with bullae.

RESULTS

Among the 7 undergoing bullectomy, the pulmonary blood flow/driving pressure relationship decreased in 5 and was unchanged in 2. Of the 11 lungs treated by bullectomy, this relationship decreased in 8 lungs, but not 3 (p < 0.01). No significant difference was seen in oxygen partial pressure in arterial and mixed venous blood or hematocrit.

CONCLUSION

We concluded that bullectomy shifted the pulmonary blood flow/driving pressure relationship downword in some cases with significant bullae.

Nitinol stent for the treatment of tracheobronchial stenosis

OBJECTIVE

The purpose of this study was to evaluate the potential utility of implantation of a nickel-titanium alloy (nitinol) stent for the treatment of malignant or benign tracheobronchial stenosis.

METHODS

We evaluated 18 patients (14 men and 4 women) who received 24 nitinol stents, between November 1997 and May 2000. All 18 patients had severe dyspnea caused by tracheobronchial stenosis. The underlying condition was malignant disease in 15 patients, and benign tracheal collapse in the other 3 patients.

RESULTS

Implantation of the stent was successfully performed in all patients. Seventeen patients experienced immediate clinical improvement in respiratory symptoms. The remaining 1 patient with a bronchial fistule after lobectomy did not benefit, and died of pneumonia at 16 days after the implantation. In 15 patients, the procedure was performed using a flexible bronchoscope under local anesthesia alone, while the remaining 3 patients needed intravenous sedation. There was no complication resulting from the stent implantation. Among the 3 patients with benign tracheal collapse, 2 patients were alive at 746 and at 401 days after the stent implantation, at the time of this report. One patient with cicatricial stenosis after intubation died of heart failure due to previous myocardial infarction. Among the 15 patients with malignant disease, 4 patients have survived for 177 to 305 days to date, while the other 11 patients have died of primary malignancy with a mean survival duration of 60.2 days.

CONCLUSION

The nitinol stent was effective in treating malignant or benign tracheobronchial stenosis, and had some remarkable advantages compared with other tracheobronchial stents. In stenting, most procedures can be performed using flexible bronchoscope under local anesthesia.

Wallstent endovascular prosthesis for the treatment of superior vena cava syndrome

OBJECTIVE

We assessed the clinical outcome of self-expanding Wallstent endovascular prosthesis in the treatment of superior vena cava syndrome due to malignant tumors.

METHODS

Eleven patients with malignant superior vena cava syndrome were treated by percutaneous implantation of the self-expanding Wallstent endovascular prosthesis across the stricture site. Patency was defined by the absence of symptoms and signs of superior vena cava syndrome.

RESULTS

Ten of the 11 experienced complete symptomatic relief within 3 days of stent implantation. The remaining 1 did not benefit, and required a second procedure, dying of heart failure 5 days after stent implantation. Ten patients remain symptomatically free of superior vena cava syndrome to date or until death in follow-up lasting 17 to 227 days.

CONCLUSION

Implantation of the self-expanding Wallstent endovascular prosthesis for malignant superior vena cava syndrome provides rapid symptomatic relief and improves the patient's quality of life.

Surgical management of multidrug-resistant tuberculosis

We report surgical resections in 3 patients with active multidrug-resistant tuberculosis. All cases involved strains of Mycobacterium tuberculosis resistant to at least isoniazid and rifampin and patients who were poor candidates for medical therapy alone. We conducted pulmonary resections (partial resection in case 1, lobectomy in case 2, and segmentectomy in case 3). The optimum multiple-drug regimen, based on drug susceptibility studies, was used preoperatively and postoperatively. In all cases, sputum smears and cultures yielded negative results postoperatively, and continue to be negative for Mycobacterium tuberculosis to date. It is recommended that, if localized disease is present and medical treatment is likely to fail, pulmonary resection be conducted for multidrug-resistant Mycobacterium tuberculosis.

Clinical assessment of unilateral pulmonary artery occlusion test with dobutamine infusion. Expansion of surgical indications in patients with primary lung cancer and impaired cardiopulmonary functions

OBJECTIVES

We evaluated the possibility of expanding indications for pulmonary resection based on an assessment of the pressure-flow relationship in pulmonary circulation.

METHODS

In 6 of 28 lung cancer patients whose total pulmonary vascular resistance index exceeded the threshold during unilateral pulmonary artery occlusion testing, we conducted unilateral pulmonary artery occlusion testing with dobutamine administration, followed by lung resection. We studied hemodynamics during testing and derived a new indication for pulmonary resection from the postoperative course.

RESULTS

Cardiac output was 3.82 +/- 0.74 l/min before testing, 3.66 +/- 0.76 l/min during pulmonary artery occlusion testing, and 5.92 +/- 1.78 l/min during unilateral pulmonary artery occlusion testing with dobutamine infusion. The total pulmonary vascular resistance index was 890 +/- 350 dyne.sec.cm-5.m2 before testing, 1170 +/- 320 dyne.sec.cm-5.m2 during testing, and 800 +/- 160 dyne.sec.cm-5.m2 during testing with dobutamine infusion. Cardiac output increased (p = 0.014) during unilateral pulmonary artery occlusion testing with dobutamine infusion, and the total pulmonary vascular resistance index significantly decreased (p = 0.034). Of the 4 patients eligible for lobectomy, 2 underwent the procedure--one undergoing segmentectomy in which pulmonary metastasis was found during surgery and the other undergoing radiotherapy for cN2 disease with chest wall invasion. Of the 2 initially ineligible for lobectomy, one underwent partial pulmonary resection and the other underwent lobectomy because the total pulmonary vascular resistance index was less than 800 dyne.sec.cm-5.m2 during selective pulmonary artery occlusion testing with dobutamine infusion, indicating eligibility for lobectomy. No severe complications of cardiopulmonary function failure after surgery occurred in any of the 5 cases.

CONCLUSIONS

Unilateral pulmonary artery occlusion testing with dobutamine infusion is useful in determining patient eligibility for pulmonary resection.

[Three cases of primary pulmonary malignant lymphoma]

Primary pulmonary malignant lymphoma is a rare disease that is thought to belong to a category of malignant lymphomas arising from mucosa- or bronchus-associated lymphoid tissue (MALT or BALT). We encountered 3 cases of primary pulmonary malignant lymphoma, Case 1: In a 51-year-old male, an abnormal shadow was detected in chest radiography in the right S9 after an operation for thyroid carcinoma. A right lower lobectomy was performed. The diagnosis was malignant lymphoma (marginal zone B-cell lymphoma). Immunohistochemical staining for IgM gave a positive result. Case 2: Multiple nodular shadows were noted in both lungs of a 55-year-old man after a bout of pneumonia. Video-assisted thoracoscopic surgery was performed, and the diagnosis was malignant lymphoma (marginal zone B-cell lymphoma). Gene analysis revealed rearrangement of a heavy chain gene. Case 3: An abnormal shadow was seen in the chest radiograph of a 60-year-old man. He was treated by right upper and middle lobectomy. The diagnosis was Hodgkin's disease, nodular sclerosing type. Chemotherapy was given after surgery and the patient is now alive without recurrence. As the pulmonary malignant lymphoma was difficult to diagnosepreoperatively, it was necessary to resect the mass for diagnostic purposes. The prognosis of a resected solitary lesion in the lobe was good. Therefore lobectomy was performed as the treatment of choice. Systemic chemotherapy is performed for the diffuse type of pulmonary lymphoma.

A clinical trial to evaluate the effects of flumethrin or ivermectin treatment on hemoparasites, gastrointestinal parasites, conception and daily weight gain in a dairy farm in Japan

A clinical trial was performed to compare the effects of flumethrin and ivermectin treatments of grazing heifers at one farm in central Japan. 64 heifers were randomly allocated into two groups. Flumethrin (1 mg/kg pour on) was applied approximately once every 3 weeks to heifers in one group and heifers in the second group were injected approximately once every month with ivermectin (200 microg/kg; id). Between groups, no significant differences were detected in the proportions of animals that showed parasitemia of Theileria sergenti and conception risks. Significantly lower average log-transformed nematode-egg counts and higher average daily weight gain were observed in the ivermectin-treated group. Animals with higher body weight at the start of grazing and lower log-transformed total nematode-egg and coccidia-oocyst counts had higher odds of conceiving. Animals with ivermectin treatment, lower body weight at the start of grazing and lower log-transformed coccidia-oocyst count had higher daily weight gain. Ivermectin may be more useful in this farm because of the higher productivity for cattle and lower cost for its usage.

[Statistics of the operations at the Department of Urology, Tone Chuo Hospital during a six-year period (June 1993-May 1999)]

A clinical statistic survey was made on the operations performed at the Department of Urology, Tone Chuo Hospital between June 1993 and May 1999. The total number of operations was 1296, consisting of 97 (7.5%) operations of the kidney, 67 (5.2%) operations of the ureter, 190 (14.7%) operations of the bladder, 454 (35.0%) operations of the prostate, 63 (4.9%) operations of the urethra, 92 (7.1%) operations of the penis, 149 (11.5%) operations of the scrotum and 184 (14.2%) other operations. With the aging society, the number of operations for those over 60 years old has exceeded 60%.

Combined thoracic aortic or upper digestive tract resection for lung cancer and malignant mediastinal tumor

OBJECTIVE

We studied possible indications and combined resection in patients with lung cancer and mediastinal tumors requiring combined thoracic aortic or upper digestive tract resection.

METHODS

Ten patients with lung cancer and malignant mediastinal tumors (9 men and 1 woman aged 39 to 72 years; mean: 60.5) underwent combined aortic or upper digestive tract resection.

RESULTS

Five--3 [corrected] with primary lung cancer, 1 with thymic cancer, and 1 with liposarcoma--, underwent combined aortic resection. In 2 each, lung cancer and malignant mediastinal tumor had infiltrated the thoracic aorta. The remaining case of lung cancer was complicated by aortic aneurysm in the distal arch. Cardiopulmonary bypass was conducted in 4, and selective cerebral perfusion in 2. Three patients are alive after 11, 22, and 61 months without disease recurrence. Those undergoing combined upper digestive tract resection all had lung cancer, with 4 having tumors infiltrating the esophagus or corpus ventriculi. The remaining patient had both lung and esophageal cancer. The patient treated with combined corpus ventriculi resection has survived 24 months and the patient treated with combined esophageal resection has survived 12 months without disease recurrence. The 1-year survival rate was 60%, 2-year 23%, and 3-year 23%. Prognosis was generally poor with the longest survival 13 months with N2 lung cancer.

CONCLUSIONS

In combined resection due to malignant mediastinal tumor, T4N0-1 lung cancer, or diseases such as aortic aneurysm, prognosis can be expected to improve. Despite the often poor prognosis in T4N2 lung cancer, surgical intervention may be indicated to avoid complications due to tumor invasion and to lengthen survival and improve quality of life.

De novo synthesis of sphingolipids is required for cell survival by down-regulating c-Jun N-terminal kinase in Drosophila imaginal discs

Mitogen-activated protein kinase (MAPK) is a conserved eukaryotic signaling factor that mediates various signals, cumulating in the activation of transcription factors. Extracellular signal-regulated kinase (ERK), a MAPK, is activated through phosphorylation by the kinase MAPK/ERK kinase (MEK). To elucidate the extent of the involvement of ERK in various aspects of animal development, we searched for a Drosophila mutant which responds to elevated MEK activity and herein identified a lace mutant. Mutants with mild lace alleles grow to become adults with multiple aberrant morphologies in the appendages, compound eye, and bristles. These aberrations were suppressed by elevated MEK activity. Structural and transgenic analyses of the lace cDNA have revealed that the lace gene product is a membrane protein similar to the yeast protein LCB2, a subunit of serine palmitoyltransferase (SPT), which catalyzes the first step of sphingolipid biosynthesis. In fact, SPT activity in the fly expressing epitope-tagged Lace was absorbed by epitope-specific antibody. The number of dead cells in various imaginal discs of a lace hypomorph was considerably increased, thereby ectopically activating c-Jun N-terminal kinase (JNK), another MAPK. These results account for the adult phenotypes of the lace mutant and suppression of the phenotypes by elevated MEK activity: we hypothesize that mutation of lace causes decreased de novo synthesis of sphingolipid metabolites, some of which are signaling molecules, and one or more of these changes activates JNK to elicit apoptosis. The ERK pathway may be antagonistic to the JNK pathway in the control of cell survival.

[Indications for lung transplantation and its selection of the candidates in Japan]

Although the annual number of lung transplant operation performed in the United States and Europe is over 1000, five year survival rate is under 50%, mainly because of obstructive bronchiolitis that is considered chronic rejection. Lung transplantation may be difficult to justify on the ground of survival consideration alone for the certain disease, such as emphysema and pulmonary hypertension. But functional recovery after lung transplantation especially, bilateral is reported very good. Among the diseases of indication of lung transplant, Cystic Fibrosis and alpha antitrypsin deficiency are very rare disease in Japan and emphysema that is most frequently reported indication in the United States, is also rare disease in the age group of lung transplantation candidate. So, idiopathic interstitial pneumonitis, pulmonary vascular disease and other miscellaneous disease are most possible indications for lung transplantation in Japan. These disease have different prognosis, we discussed the timing of registration and operation of lung transplantation in each disease.

Optical-fibre scanning near-field optical microscope for cryogenic operation

We have developed a new type of scanning near-field optical microscope (SNOM) utilizing optical fibres. The probe tip is controlled by shear force feedback with a fibre interferometer and signal light is collected directly by a multimode fibre. These features make the SNOM head more compact and less sensitive to vibration. Further advantages of this new type of SNOM are that it obviates the need for optical windows in the cryostat and offers easy optical alignment.

The attenuated effect of ATP-sensitive K+ channel opener pinacidil on renal haemodynamics in spontaneously hypertensive rats

In hypertension, impairment of hyperpolarization by K+ efflux through ATP-sensitive K+ (K(ATP)) channels may contribute to the elevated renal vascular resistance. To elucidate such a role for K(ATP) channels in the renal vasculature, we used micropuncture techniques to examine the effect of K(ATP) channel opener, pinacidil (0.15 mg/h per kg body wt i.v.), on renal and glomerular haemodynamics in spontaneously hypertensive rats (SHR) and in normotensive controls (Wistar Kyoto, WKY). Since pinacidil reduced blood pressure significantly in both groups, the abdominal aorta was clamped before pinacidil administration to yield a renal perfusion pressure equivalent to that during pinacidil infusion. Pinacidil significantly decreased renal vascular resistance in both groups, but the relative change from baseline value was greater in WKY than in SHR. These effects of pinacidil were abolished by pretreatment with glibenclamide (3 mg/kg body wt i.v.). Proximal tubular stop-flow pressure (Psf), an index of glomerular capillary pressure, was significantly elevated by pinacidil infusion in WKY, a response abolished by pretreatment with glibenclamide, but not in SHR. The tubuloglomerular feedback response of Psf was not affected by pinacidil in either group. These data suggest that the activity of K(ATP) channels in SHR may be attenuated in the renal microvasculature. This may contribute to the elevated vascular tone in the renal preglomerular vasculature in SHR.

The K(ATP) channel opener nicorandil: effect on renal hemodynamics in spontaneously hypertensive and Wistar Kyoto rats

Adenosine triphosphate-sensitive K channels (K(ATP)) may subserve vasodilation in the renal microvasculature. Using micropuncture techniques, we examined whether the renal vasomotor action of K(ATP) differs in hypertensive and normotensive animals. Nicorandil (NC), a K(ATP) opener, was given i.v. (1 mg/hr/kg) to spontaneously hypertensive rats (SHR) or Wistar Kyoto rats (WKY). Mean arterial blood pressure decreased in both groups. Renal blood flow was almost unchanged in SHR but increased significantly in WKY. This effect was completely abolished by pretreatment with glibenclamide (GC; 3 mg/kg i.v.). To investigate the effect of NC on the regulatory mechanism of renal microcirculation, we measured proximal tubular stop-flow pressure (SFP) and assessed tubuloglomerular feedback (TGF) by monitoring SFP during loop perfusion with artificial tubular fluid. NC significantly increased SFP in WKY, an effect abolished by pretreatment with GC. In SHR, however, treatment with NC elicited no significant change in SFP. TGF response was not affected by NC treatment in either group. The data suggest that K(ATP) may modulate preglomerular vascular resistance, especially in the larger vascular segments not subject to TGF regulation, and may be attenuated in SHR. This might, at least in part, be attributable to the increased vascular resistance in SHR.

[Report on a case of adult rhabdomyosarcoma subjected to tumorectomy and lobectomy]

Rhabdomyosarcoma (RMS) rarely occurs in adult and intra thoracic activity. This is a report on a case we experienced of adult RMS, which was subjected to tumorectomy and lobectomy. The patient was a 23 years old male, who first consulted a hospital in his neighborhood due to anterior chest pain suffered since May 1995. Since the examination showed an abnormal shadow in right anterior mediastinum, the patient was referred to our department. By biopsy under CT, the patient was diagnosed as having embryonal type of RMS and underwent surgery. The outcome was good and the patient is currently in the course of chemotherapy using IRS (Inter-group Rhabdomyosarcoma study)-III.

Effect of adenosine on adrenergic neurotransmission and modulation by endothelium in canine pulmonary artery

To determine the effect of adenosine on adrenergic neurotransmission in pulmonary vasculature and its modulation by endothelial cells, we studied canine pulmonary arteries under isometric conditions in vitro. Adenosine decreased the contractile responses to electrical field stimulation but had no effect on those to norepinephrine. This inhibitory effect was concentration dependent, with a rank order of potency of NECA > 2-chloroadenosine > adenosine >> APNEA (an A3-adenosine-receptor agonist) > CGS-21680 (an A2a agonist) > CCPA (an A1 agonist). Adenosine reduced the electrical field stimulation-evoked 3H overflow in superfused pulmonary artery previously soaked in [3H]norepinephrine. Pretreatment with the adenosine uptake blocker dipyridamole or the adenosine deaminase inhibitor deoxycoformycin enhanced the adenosine action, and this enhancement was not observed in the endothelium-denuded tissues. Adenosine deaminase activity was found in endothelial cells. Therefore, adenosine inhibits norepinephrine release via an A2b-receptor mechanism, an effect that may be modulated by uptake and metabolism by endothelial cells.

Effects of a calcium channel blocker, manidipine hydrochloride, on the regulatory mechanism of glomerular capillary pressure in SHR

In an attempt to clarify whether glomerular capillary pressure (Pgc) in hypertension can be reduced by a calcium channel blocker (CaB), renal clearance and micropuncture experiments were carried out on male heminephrectomized spontaneously hypertensive rats (SHR; n = 15). Renal circulatory parameters (RBF and GFR) and proximal tubular stop flow pressure (Psf) were measured during the control period, during manual aortic clamping, and after administration of manidipine hydrochloride (MDP, 10 micrograms/kg body weight in bolus). Because Psf only represents Pgc during zero tubular flow, the responsiveness of tubulo-glomerular feedback (TG feedback) was also assessed to obtain the "steady state Pgc", an operating point in each experimental period. Administration of MDP decreased systemic blood pressure (SBP) and renal vascular resistance (RVR), but increased renal blood flow (RBF) significantly. Psf decreased following the administration of MDP (33.65 +/- 1.45 mmHg), reaching a lower level than during aortic clamping (39.93 +/- 2.37 mmHg) or in the control period (50.78 +/- 2.73 mmHg). TG feedback responsiveness was attenuated during clamping, and was incompletely inhibited by MDP, whereas the operating point (29.3 mmHg) was lower than during clamping (32.9 mmHg) or in the control period (41.0 mmHg). The stability of RBF during the alteration of renal perfusion pressure (RPP) was not abolished by MDP. From these results, we suggest that MDP significantly decreases Pgc in the steady state not only by the reduction of RPP, but also by the amelioration of renal microcirculation.

[Eight cases of thymic carcinoma]

Eight cases of thymic carcinoma (mean age 62 years, 5 males and 3 females) were treated in our hospital from Apr. 1988 to Mar. 1993, which were 21% of thymic epithelial tumors. The histologic subtypes of thymic carcinoma were 3 squamous, 4 undifferentiated, and 1 adenocarcinoma, respectively. Computed tomography showed extrathymic metastases to the mediastinal lymph nodes in 6 cases. All cases underwent thoracotomy, and postoperative radiotherapy or chemotherapy were performed. A case of squamous cell carcinoma in stage II who underwent total resection followed by irradiation is alive and disease free 5 years after surgery. However, the remaining 7 cases died of the disease within 29 months. 8 cases of thymic carcinoma and 7 of thymoma were studied immunohistologically on the formalin-fixed and paraffin-embedded tissues. Higher positivity of EMA in thymic carcinoma was noted comparing to ordinary thymoma, suggesting that EMA is a useful parameter of potential malignancy of the thymic epithelial neoplasms.