Biomedical subjects

A Akashi

Publications and source records attributed to A Akashi.

At least 19 recordsLinked to original sources

PubMed2006

Randomised study of adjuvant chemotherapy for completely resected p-stage I-IIIA non-small cell lung cancer.

We evaluated the therapeutic usefulness of adjuvant chemotherapy in patients with completely resected non-small cell lung cancer (NSCLC). We also examined the relation between DNA ploidy pattern and the response to chemotherapy. A total of 267 patients with NSCLC (pathologically documented stage I, II, or IIIA) underwent complete resection, and DNA ploidy pattern was analysed. Patients with stage I disease (n=172) were randomly assigned to receive surgery alone (group A) or surgery followed by adjuvant chemotherapy (UFT (oral anti-cancer drug, a combination of Uracil and Tegaful) 400 mg day-1 for 1 year after surgery; group B). Stage II or IIIA disease patients (n=95) were randomly assigned to surgery alone (group C) or surgery followed by chemotherapy (two 28-day courses of cisplatin 80 mg m-2 on day 1 plus vindesine 3 mg m-2 on days 1 and 8, followed by UFT 400 mg day-1 for at least 1 year; group D). Eight-year overall survival rate in patients with stage I disease was 74.2% (95% confidence interval (CI): 64.4-84.0%) in group B and 57.6% (95% CI: 46.4-68.8%) in group A (P=0.045 by log-rank test). In patients with stage II and IIIA disease, no difference was found between groups C and D. Analysis according to DNA ploidy pattern revealed no difference between the groups. Postoperative chemotherapy with UFT was suggested to be useful in patients with completely resected stage I NSCLC. No difference was seen in relation to DNA pattern in any treatment group.

Age Factors↗

PubMed2005

VATS with a supraclavicular window for huge substernal goiter: an alternative technique for preventing recurrent laryngeal nerve injury.

A careless attempt to remove a huge substernal goiter using the cervical approach can lead to recurrent laryngeal nerve injury, which has been consistently reported after the surgery. We present an alternative and less invasive technique combining video-assisted thoracoscopic surgery (VATS) with a supraclavicular approach. This technique seems to offer improved exposure and reliable control of the neuro-vascular structures in the anterior mediastinum when resecting a huge substernal goiter that may prevent nerve injury.

Aged↗

PubMed2004

Complete versus assisted thoracoscopic approach: a prospective randomized trial comparing a variety of video-assisted thoracoscopic lobectomy techniques.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) lobectomy does not represent a unified approach, but rather a spectrum of operative techniques ranging from a complete endoscopic thoracotomy to a minithoracotomy. A prospective randomized trial was conducted to compare the differences in these techniques and their results to determine the best of VATS lobectomy for lung cancer. METHODS: This study randomized 39 consecutive patients with clinical stage I lung cancer to undergo either a complete (C-VATS, n = 20) or an assisted (A-VATS, n = 19) VATS approach for pulmonary lobectomy. RESULTS: The operating time was longer (p = 0.002) and blood loss was less (p = 0.004) with C-VATS than with A-VATS. Although there was no significant difference in analgesic use or duration of thoracic drainage between the groups, a shorter hospitalization was observed after C-VATS. Serum peak levels of postoperative inflammatory markers (white blood cell count, C-reactive protein, creatine phosphokinase) were lower with C-VATS and an earlier return to normalization than with A-VATS. CONCLUSION: Various differences exist among the VATS lobectomy techniques, and complete VATS lobectomy as a purely endoscopic surgery may be technically feasible and a satisfactory alternative to the conventional procedure for stage I lung cancer.

Aged↗

PubMed2002

A strategy in wastewater treatment process for significant reduction of excess sludge production.

A novel wastewater treatment process (S-TE PROCESS) with significantly reduced production of excess sludge has been developed. The process consists of two different stages, one for a biological wastewater treatment and the other for a thermophilic aerobic digestion of the resulting sludge. A portion of return sludge from the wastewater treatment step is injected into a thermophilic aerobic sludge digester (TASD), in which the injected sludge is solubilized by the action of thermophilic aerobic bacteria. The solubilized sludge is returned to the aeration tank in the wastewater treatment step for its further degradation. Pilot-scale facilities of the S-TE process and the conventional activated sludge process as a control, both treating the same industrial wastewater, were comparatively operated for totally 270 days. As a result, 93% reduction in overall excess sludge production was achieved in the S-TE operation. The SS solubilization rate in TASD was stable at around 30%. Only a slight increase in the effluent SS and TOC concentrations was observed compared with those of the control facility. Otherwise the removal efficiency of TOC was approximately 95% for both plants. A full-scale plant treating domestic sewage was operated for three years, showing 75% reduction of overall excess sludge production. It was concluded that the new process was feasible.

Bacteria, Aerobic↗

PubMed2001

Videoendoscopic surgery combined with a minimal sternotomy for removing a thyroid tumor extending into the mediastinum. A case report.

We report the case of a 55-year-old man with a giant goiter descending to the mediastinum. Video-endoscopic surgery combined with a minimal sternotomy was performed to remove a thyroid tumor. In the course of our dissection of the subplatysmal space, an endoscopic approach was applied to avoid incisions of the neck. Three trocars were inserted from the anterior chest wall, and carbon dioxide (CO2) was insufflated at a pressure of 5 mmHg to create a working space. This technique improves the cosmesis of thyroidectomies and cervical operations.

Adenoma↗

PubMed2001

Minimally invasive surgery for lung cancer with coronary artery disease.

We report a 69-year-old woman with lung cancer and severe stenosis in the left anterior descending coronary artery. To perform a curative operation for the lung cancer without myocardial infarction, minimally invasive direct coronary artery bypass and left lower lobectomy with video-endoscopic assistance were performed simultaneously. There was no major complication, and she was discharged at 14 days after the operation. This procedure may be useful and safe for patients with lung cancer and coronary artery disease.

Adenocarcinoma↗

PubMed2001

An analysis of video-assisted thoracoscopic resection for mediastinal masses in 150 cases. An overview of the pansternal approach, histology, and complications.

BACKGROUND: To clarify the usefulness of the diagnosis and treatment of mediastinal masses, by video-assisted thoracoscopic surgery (VATS), we performed a retrospective multi-institutional study to delineate the type of approach, histopathology, and complications associated with these entities. METHODS: We analyzed 150 patients who underwent the VATS procedure at several institutions between 1991 and 1999. RESULTS: VATS resections were performed using various combinations of the "pansternal approach." The unilateral thorax approach was applied in 135 patients, the bilateral thorax approach combined with the suprasternum approach in seven patients, the unilateral thoracic approach combined with the supraclavicular approach in three patients, the infrasternal approach in three patients, and the bilateral thoracic approach combined with both the infrasternal and the suprasternal approaches in two patients. Thoracoscopic resections or biopsies diagnosed 140 benign and 10 malignant mediastinal masses. There were operative complications in nine patients (6%). Eight patients (5.3%) were converted to conventional thoracotomy. CONCLUSION: VATS is a safe, effective, minimally invasive technique that can facilitate the resection of mediastinal masses when the pansternal approach is applied as appropriate for the location of the tumor.

Adolescent↗

PubMed2001

Release profile of antimicrobial agents from alpha-tricalcium phosphate cement.

A new method for treating carious dentine with alpha-tricalcium phosphate (alpha-TCP) dental cement containing antimicrobial agents has been recently introduced. However, the release behavior of antimicrobial agents from this cement has not yet been clarified. The aim of this study is therefore to examine the release profile of the antimicrobial agents from the alpha-TCP cement. Three kinds of antimicrobial agents (metronidazole, cefaclor and ciprofloxacin) were added to two commercially available alpha-TCP cements (new apatite liner type I and type II). The set cements were then immersed in water at 37 degrees C and the released antimicrobial agents and Ca ion were determined at regular intervals for three months. In addition, scanning electron microscopic observations were conducted before and after immersion for three months. The release profile of the cements containing antimicrobial agents varied depending on the types of antimicrobial agents. The incorporation of antimicrobial agents affected the setting reaction of the cements. The release behavior of the drugs also varied depending on the types of the cements. The differences in the release profile between type I and type II cements reflected the structures and compositions of their matrices.

Anti-Infective Agents↗

PubMed2001

Composite resin restoration and postoperative sensitivity: clinical follow-up in an undergraduate program.

OBJECTIVES: To analyze the relationship between the cavity depth and liners with postoperative sensitivity of resin composite restorations. METHODS: A clinical follow-up was conducted on 319 resin composite restorations made in the final year of an undergraduate program over a 3-year period. Along with the analyses of cavity type, cavity depth, type of pulpal protection and the materials used, the postoperative sensitivity was also examined on each restoration. RESULTS: Thirty-nine percent of the restorations had no protective layer (Group 1). As the depth of the prepared cavities increased, the restorations received one of the three pulpal protection methods; a calcium hydroxide base (Group 2), glass ionomer cement (Group 3), or protection with a calcium hydroxide base in combination with glass ionomer cement (Group 4). The incidence of postoperative sensitivity showed no significant difference among Groups 1, 2 and 3, but was significantly lower in Group 1 than in Group 4. The restorations made in shallow and medium depth cavities demonstrated significantly less-postoperative sensitivity than those made in deep cavities. The newer generation dentine-bonding agents showed a significantly lower incidence of postoperative sensitivity than the early generation group. CONCLUSIONS: Postoperative sensitivity in resin composite restorations was not related to the absence of protective layers but increased with the depth of cavities restored with the resin composite. The type of dentine-bonding agents could also be responsible for postoperative sensitivity.

Adolescent↗

PubMed2001

[Successful thoracoscopic resection of pulmonary arterio-venous fistula].

A 65-year-old female was admitted for further examination of an abnormal shadow on a chest roentgenogram. Chest computed tomography revealed a lobular nodule with blood vessels, which was diagnosed as pulmonary arterio-venous fistula (PAVF). Thoracoscopic resection was performed under general anesthesia. The fistula was situated directly below the pleura of the left lower lobe. Partial resection of the left lung including the PAVF was performed with an autosuture device dedicated to endoscopic surgery (Endo GIA II). The patient was discharged from our hospital 3 days after surgery without major complications. Mild hypoxemia was corrected after the surgery. Thoracoscopic resection is considered to be safe and useful for a solitary PAVF existing a peripheral field of the lung.

Aged↗

PubMed2000

Ipsilateral recurrence frequency after video-assisted thoracoscopic surgery for primary spontaneous pneumothorax.

OBJECTIVE: We retrospectively evaluated the results of video-assisted thoracoscopic surgery for primary spontaneous pneumothorax and recurrence. METHODS: A series of 424 patients with primary spontaneous pneumothorax were treated by video-assisted thoracoscopic surgery-289 with an ipsilateral recurrent episode, 88 with persistent air leakage for 7 days or longer, 34 with a contralateral episode, 9 with hemopneumothorax, and 4 with tension pneumothorax. The commonest management was stapling of an identified bleb, undertaken in 375 patients (88.4%). Pleural abrasion was conducted in 250 (59.0%), but the abraded area was one-third or less of the thoracic cavity in 187 (74.8%). RESULTS: No operative deaths occurred. Revisional thoracotomy was required in 1 patient with postoperative bleeding and another with incomplete postoperative lung reexpansion; 26 had prolonged air leakage, but none required revisional thoracotomy. During a mean follow-up of 31.4 months, ipsilateral pneumothorax recurred in 40 patients (9.4%), with 26 (65.0%) having recurrence within 1 year postoperatively. A video-assisted thoracoscopic surgery was conducted again in 8, and thoracotomy in 14. CONCLUSIONS: The ipsilateral recurrence of primary spontaneous pneumothorax after video-assisted thoracoscopic surgery was high at 9.4%. If video-assisted thoracoscopic surgery is to be considered as a treatment for spontaneous pneumothorax, we must therefore reduce postoperative ipsilateral recurrence by training practitioners not to overlook blebs during the procedure and/or consider widening the area of pleurodesis.

Adolescent↗

PubMed2000

Solubilization of organic sludge by thermophilic aerobic bacteria as a pretreatment for anaerobic digestion.

Solubilization of organic sludge by thermophilic aerobic bacteria as a pretreatment for anaerobic digestion was investigated. The thermophilic bacteria which solubilized organic sludge were isolated from the thermophilic aerobic digestion reactor. The bacterium type SPT2-1 could grow at pH ranging from 5.0 to 8.5 with optimal temperature at 60-70 degrees C. In batch experiments, 25-30% of volatile suspended solids (VSS) in the pre-heated sludge were solubilized on inoculating with the isolated bacteria although little was solubilized without inoculation. The isolated bacteria appeared to secret the extracellular enzymes including proteases and amylases. In continuous flow experiments, sludge solubilization rate (VSS removal) was around 40% under aerobic as well as microaerobic conditions. No accumulation of volatile fatty acids in the treated sludge was observed under aerobic conditions while significant amounts of them were accumulated under microaerobic conditions. Production of biogas on anaerobic digestion of the microaerobically-pretreated sludge was increased by 1.5 when compared with the sludge without pretreatment.

Amylases↗

PubMed1999

The relationship between water absorption characteristics and the mechanical strength of resin-modified glass-ionomer cements in long-term water storage.

The purpose of this study is to elucidate the water absorption characteristics of resin-modified glass-ionomer cements and to also investigate the relationship between the characteristics and mechanical strength after long-term water storage. The mechanism of water diffusion in these cements is also discussed. Water absorption was measured using a gravimetric analysis for 12 m, while the diffusion coefficient was calculated using Fick's law of diffusion. Water solubility was determined based on the weight of the residue in the immersed water. The compressive and diametral tensile strength were measured at 1, 2, 6, and 12 m. A correlation was observed between the diffusion coefficient and equilibrium water uptake, which thus suggests the water in the cements to diffuse through micro-voids in accordance with the 'Free volumetric theory'. A correlation was seen between the solubility and diffusion coefficient of the cements. The deterioration ratio, defined as the ratio of the strength at 12 m versus that at 1 m, was also calculated. Finally, a negative correlation was observed between the deterioration ratio of the compressive strength and the diffusion coefficients of the cements.

Absorption↗

PubMed1999

Formulation of glutaraldehyde disinfectant for alginate impressions.

The effect of buffer agents incorporated in glutaraldehyde disinfectants on the surface quality of dental models was examined by the measurement of surface roughness, X-ray diffraction analysis and SEM observation. Seven experimental glutaraldehyde disinfectants were prepared using two buffer agents, potassium acetate alone or potassium acetate and sodium hydrogen carbonate in combination. Four kinds of sulfate--zinc, calcium, potassium and magnesium sulfate--were added to these disinfectants in order to accelerate the hydration of calcium sulfate hemihydrate. The impressions treated with the experimental disinfectants for 1 h produced stone surfaces which had significantly lower surface roughness values than those treated with the commercial disinfectants (p < 0.05). The X-ray diffraction analysis and SEM observation showed that these superior surfaces were produced as a result of significant reductions in the amount of residual calcium sulfate hemihydrate. Replacement of buffer agents in commercial glutaraldehyde disinfectants with chemicals such as those studied in the present study will improve the surface quality of dental stone.

Alginates↗

PubMed1998

An anergic cytotoxic T lymphocyte clone exhibits granule exocytosis-mediated cytotoxicity.

T cell receptor (TCR) occupancy in the absence of a costimulatory signal transforms T helper (Th) cells or cytotoxic T lymphocytes (CTL) into a state of anergy. The anergic T cells are unable to produce cytokines; nevertheless, they maintain their killing activity. We investigated the mechanisms through which anergic CTL causes lysis of target cells. Treatment of a CTL clone with phorbol myristate acetate and calcium ionophore A23187 (P/A) transformed these cells to anergic cells. While the anergic CTL clones failed to secrete TNF-alpha in the culture supernatant, they were still able to kill antigen-specific target cells via a granule exocytosis-mediated pathway. This was evident by the synthesis of perforin mRNA and release of N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester esterase by these cells. The anergic CTL clone also showed a low degree of Fas-mediated lysis of normal target cells. In addition, we generated anergic bulk CTL by treatment with P/A and observed that the anergic bulk CTL failed to produce TNF upon antigen stimulation, but retained target killing activity via a granule exocytosis mechanism. Our results suggest that the killing mechanisms of anergic CTL are mediated to a large extent by a granule exocytosis-mediated pathway.

Animals↗

PubMed1998

Thoracoscopic parasternal lymph node dissection for the staging of breast cancer.

With the advent of advanced thoracoscopic techniques, new applications have been expanding their roles in thoracic surgery. The aim of this paper is to introduce our new thoracoscopic approach in performing parasternal lymph node dissection of advanced breast cancer for its staging. This technique does not need the removal of any costal cartilage which is usually done in the conventional classical technique after radical mastectomy. Thoracoscopic procedure, in which wide and complete parasternal lymph node dissection is done, is minimally invasive and easy to perform. Therefore, the thoracoscopic technique may be a suitable alternative to the conventional approach in the future.

Journal Article↗

PubMed1998

[Effect of granisetron in preventing emesis due to anti-cancer drug (CDDP) administration pulmo-mediastinal malignancies--comparison of simultaneous infusion with the conventional method of administration].

For patients with pulmo-mediastinal malignancies, the antimetic effect of granisetron was studied in the following two ways. Firstly in the standard method, 40 micrograms/kg of granisetron was infused for 30 minutes, 30 minutes before CDDP infusion. Secondly, in the simultaneous method, granisetron was mixed with CDDP in a 500 microliters infusion bottle, and then infused over 0.5-3 hours. Over a 24-hour time course, significantly effective rates (nausea less than mild, and vomiting 2 times less) were 72.7% in the simultaneous group (n = 22) and 52.6% in the standard group (n = 19). The non-effective rates were 18.2% and 15.8%, respectively. Although the results were not statistically significant, the simultaneous method is easier to perform and it seems to confer a slightly better clinical outcome than the conventional method.

Aged↗

PubMed1997

Thoracoscopic surgery combined with a supraclavicular approach for removing superior mediastinal tumor.

This report introduces our new technique of thoracoscopic surgery combined with a supraclavicular approach for removing superior mediastinal tumor. A 68-year-old woman noticed a tumor palpable in the left supraclavicular fossa. The patient had no pain around the neck and shoulder. A radio-opaque shadow 6 cm in diameter was detected in her left apical lung field on chest roentgenogram. Chest CT and MRI showed that the tumor was located in the superior mediastinum, extending up to the thoracic inlet, and there was no invasion of the surroundings. At first, a thoracoscopic examination was performed to assess the possibility of the excision. After dissecting the tumor from the mediastinal tissue and the first costovertebrae as far as possible by thoracoscopic surgery, a supraclavicular approach was used to enter the thoracic cavity. Complete resection of the tumor was successfully performed by thoracoscopic surgery combined with a supraclavicular approach. The tumor was removed in a plastic bag through the supraclavicular defect. Postoperative histopathology revealed that the tumor was a benign neurogenic one. A satisfactory follow-up of 5 postoperative days was observed without any complications, and the patient was discharged. The procedure was safe, easy, and minimally invasive to perform. Moreover, the supraclavicular approach could be used to add trocar port if needed.

Aged↗