Biomedical subjects

S Wada

Publications and source records attributed to S Wada.

At least 19 recordsLinked to original sources

PubMed2006

Expression of foreign type I ribulose-1,5-bisphosphate carboxylase/ oxygenase (EC 4.1.1.39) stimulates photosynthesis in cyanobacterium Synechococcus PCC7942 cells.

A reporter gene assay revealed that promoters derived from Synechococcus PCC7942 (S.7942) psbAI and Synechocystis PCC6803 (S.6803) psbAII were suitable for the expression of foreign ribulose-bisphosphate carboxylase (RuBisCO; EC 4.1.1.39) in S.7942 cells. Transformational vectors with a promoter and a foreign RuBisCO gene, cvrbc originated from Allochromatium vinosum, were constructed on a binary vector, pUC303, and introduced to S.7942 cells. When the cvrbc was expressed with the S.7942 psbAI promoter, the total RuBisCO activity increased 2.5- to 4-fold than that of the wild type cell. The S.6803 psbAII promoter increased the activity of the transformant 1.5-2 times of that of wild type cell. There was a significant increase in the rate of photosynthesis depending on the increase of RuBisCO activity. The maximum rate of photosynthesis of the transformant cell was 1.63 times higher than that of the wild type under the illumination of 400 micromol m(-2) s(-1), at 20 mM bicarbonate and at 30 degrees C. Although the photosynthesis of the higher plant is limited by the ability of photosystems under high irradiance and the high CO(2 )concentration, that of the S.7942 cell is limited by the RuBisCO activity, even at high CO(2) concentrations and under high irradiance.

Gene Expression↗

PubMed2006

Primary extramedullary plasmacytoma of the small intestine. A case report and review of the literature.

A case of primary extramedullary plasmacytoma of the small intestine in a 73-year-old Japanese woman was reported. The patient underwent local resection of the tumor, and showed no signs of local recurrence or dissemination of the disease after 28 months follow-up. The tumor cells had relatively large nuclei with distinct nucleoli and wide and slightly basophilic cytoplasm with a high N/C ratio which showed the morphology of atypical plasma cells. Immunohistochemical examination revealed that the tumor cells contained IgG gamma-type immunoglobulin in their cytoplasm but they did not contain IgA, IgM, IgD, and kappa-light chains. The tumor cells were also positive for CD79a and CD138 and negative for LCA, CD20 and CD45RO. These findings clearly indicated this case to be plasmacytoma.

Aged↗

PubMed2005

Novel approach on the risk assessment of oxidized fats and oils for perspectives of food safety and quality. I. Oxidized fats and oils induces neurotoxicity relating pica behavior and hypoactivity.

Food poisoning caused by deteriorated fat and oil in instant noodles was first reported in Japan approximately 40 years ago. In these cases, many people developed neurotoxic symptoms such as emesis and discomfort. The degree of oxidation of the fat and oil in the instant noodles that induced food poisoning was at least 100 meq/kg in peroxide value (PV). No general toxicity studies with animals, however, have examined the toxicity of fat and oil oxidized to that extent. In this study, pica behavior, a behavior characterized by eating a nonfood material such as kaolin and that relates to the degree of discomfort in animals, and alterations of locomotor activity of rats eating deteriorated fat and oil were measured. The groups fed fat and oil with at least 138.5 meq/kg PV consumed significantly more kaolin compared to the control group. Furthermore, rats that ate deteriorated fat and oil with at least 107.2 meq/kg PV had significantly decreased locomotor activity compared to control rats. These phenomena suggest that oxidized fat and oil with at least 100 meq/kg PV induce neurotoxicity. The toxicity of oxidized fat and oil has only been addressed using general toxicity tests, but the present results reveal the importance of evaluating toxicity by using other measures.

Animals↗

PubMed2005

Production of methyl-oxonium ion and its complexes in the core-excited (HC(O)OCH3)n clusters: H/H+ transfer from the alpha carbonyl.

Dissociation of free methyl-formate (MF), HC(O)OCH3, and its clusters (MF)n, (HC(O)OCH3)n, induced by core-level excitation was studied near the oxygen K edge by time-of-flight fragment-mass spectroscopy. Besides the protonated clusters, (MF)nH+ with n < or = 15, we identified the production for another series of (MF)mCH3OH2+ with m < or = 14 as well as methyl-oxonium ion, CH3OH2+, characteristic of hydrogen transfer reactions in the cationic clusters. Here; specifically labeled methyl-formate-d (MFD), DC(O)OCH3 was also used to examine the core-excited dissociation mechanisms. Deuterium-labeled experiments indicated that MFD+ with low internal energies, partially generated after the core excitation, produces CH3OD+ via a site-specific deuterium transfer from the alpha carbonyl in the molecular cation and that CH3OD2+ can be formed via the successive transfer of another deuterium from the neighbor molecule in the clusters. The deuteron (proton) transfer was also found to take place preferentially from the alpha carbonyl of the neighbor molecule for the production of deuteronated (MFD)nD+, (protonated (MF)nH+), clusters. The minimal energy requirement paths were examined for dimer (MF)2+ cation to support the present dissociation mechanisms of core-excited (MF)n clusters using ab initio molecular-orbital calculations.

Journal Article↗

PubMed2005

A hydrogen peroxide-generating agent, 6-formylpterin, enhances heat-induced apoptosis.

The enhancement of heat-induced apoptosis by 6-formylpterin, an intra-cellular generator of hydrogen peroxide (H2O2), was examined in human myelomonocytic lymphoma U937 cells. The cells were treated with either 6-formylpterin alone at a nontoxic concentration of 300 microM (37 degrees C), heat shock (44 degrees C per 20 min) alone or a combination of the two, then incubated at 37 degrees C for 6 h. Assessments of apoptosis, mitochondrial membrane potential and caspase-3 activation were performed by flow cytometry. Moreover, caspase-8 activation and changes in the intra-cellular Ca2+ concentration ([Ca2+]i) were examined. Bax, Bcl-2, Bcl-XL, Bid, cytochrome c and PKCd were detected by Western blotting. The induction of heat-induced apoptosis evaluated by morphological observation and DNA fragmentation were promoted by the addition of 6-formylpterin. Mitochondrial membrane potential was decreased and the activation of caspase-3 and -8 was enhanced in the cells treated with the combination. A decreased-expression of Bid was noted, although no significant changes in Bax, Bcl-2 and Bcl-XL expression were observed after the combined treatment. Furthermore, both the release of cytochrome c from mitochondria to cytosol and the translocation of PKCd from cytosol to mitochondria, which were induced by heat shock, were enhanced by the addition of 6-formylpterin. The number of cells with a higher [Ca2+]i was also increased by the addition of 6-formylpterin. These findings suggest that the increase in [Ca2+]i, the activation of the mitochondria-caspase dependent pathway and the translocation of PKCd to mitochondria play principal roles in the enhancement of heat-induced apoptosis by 6-FP.

Apoptosis↗

PubMed2005

Development of a wearable computer system with a hands-free operation interface for the use of home health caregiver.

We previously developed a network-based medical care support system called the Hyper Hospital, a computer network with an interface that is dedicated to patient care. In this study, we developed a wearable information system that is designed so that a caregiver can obtain information and control various support devices within the home-care environment. In our system, the wearable computer itself consists of a computer network built into a jacket. Each required function is implemented by a dedicated small computer connected to the in-jacket network. A new function may easily be added to the system by connecting additional computers. A network comprising such a set of single-function computers becomes a highly efficient information system when applied to health care support.

Caregivers↗

PubMed2004

Effect of flow disturbances remaining at the beginning of diastole on intraventricular diastolic flow and colour M-mode Doppler echocardiograms.

A computational model of the fluid dynamics of intraventricular flow was used to investigate the importance of the effects of flow disturbances existing within the left ventricle (LV) at the onset of diastole on a diastolic flow field. The simulation started with a quiescent flow state; it continued for a number of cardiac cycles to obtain a cyclically repeatable flow. After the flow became periodic, the initial diastolic flow was not quiescent: flow disturbances, remnants of a systolic flow, were present within the LV. Nevertheless, they faded away during an acceleration phase of diastole and almost ceased by the end of this phase. Consequently, a flow field during a deceleration phase of diastole, characterised by the formation of a vortex ring, was hardly affected by the initial flow disturbances. The propagation velocity of a colour M-mode Doppler echocardiogram obtained by scanning velocity along the LV long axis was 0.58 m s(-1) in the case where diastolic flow was initially quiescent and 0.56 m s(-1) in the case where flow disturbances existed at the beginning of diastole. These results indicated that the colour M-mode Doppler echocardiographic technique captures flow dynamics produced purely by ventricular expansion, with little influence from initial diastolic flow disturbances.

Computer Simulation↗

PubMed2004

Two-step three-field lymph node dissection is beneficial for thoracic esophageal carcinoma.

Aggressive surgery including extensive lymph node dissection is considered necessary to improve the long-term survival of patients with esophageal carcinoma. While three-field lymph node dissection is widely performed for patients with thoracic esophageal carcinoma, cervical lymph node metastasis is uncommon. In order to reduce surgical stress, we have developed a two-step three-field lymph node dissection procedure for thoracic esophageal carcinoma. In the first-step operation, total thoracic esophagectomy through a right thoracotomy is performed. Mediastinal and abdominal lymph node dissection is performed synchronously. When recurrent nerve lymph node metastasis is pathologically positive, cervical lymph node dissection is performed about 3 weeks after the first operation (second step). Of 343 patients with carcinoma of the esophagus surgically treated in our department between 1990 and 2001, 146 underwent the operation described above. Three-field dissection was performed in 68 patients (group A), while two-field dissection was performed in 78 patients (group B). In the 68 group A patients, cervical lymph node metastasis was positive in 15 patients (22%). There was no marked difference in the onset of major complications between the two groups. The 5-year survival rate was 58% for group A and 61% for group B, not a statistically significant difference. In 78 of the 146 patients, it was possible to avoid cervical lymph node dissection without negatively affecting therapeutic outcomes. Two-step three-field lymph node dissection can reduce surgical stress of patients with good clinical outcome.

Aged↗

PubMed2003

Computational study on the evolution of an intraventricular vortical flow during early diastole for the interpretation of color M-mode Doppler echocardiograms.

A computational fluid dynamics study of intraventricular flow during early diastole was carried out using a 3D model of the human left ventricle (LV). It was found that a vortical flow formed under the aortic orifice and then grew in size and extended laterally along the ventricular wall towards the posterior side. With further expansion of the LV, it developed into an annular vortex asymmetrically enlarged on the side of the aortic orifice, narrowing the passage of blood inflow and thus causing a shift of the high-velocity portion of inflow towards the apex. This appeared as an elongation of the aliasing area when the velocity of the inflow was expressed as a spatiotemporal map in the same manner as a color M-mode Doppler (CMD) echocardiogram. Based on these findings, it was concluded that the shape of the aliasing area in a CMD echocardiogram shows the change in the velocity of blood inflow affected by the development of an annular vortex formed in the LV.

Blood Flow Velocity↗

PubMed2003

Cyclooxygenase-1 and -2 in human testicular tumours.

In this study, we investigated the expression of cyclooxygenase (COX)-1 and -2 in human testicular cancer (TC) and normal testis (NT) tissues, as well as the effects of COX ligands on viability and proliferation. Tumour specimens were obtained from 72 patients with TC and 20 patients with NT. RT-PCR and immunohistochemical methods were used to determine COX expression. While COX expression was not noted in any of the NT tissues, a marked expression was observed in the TC samples. The extent and intensity of immunoreactive COX-1 and -2 polypeptides in the TC tissues was statistically greater than the expression in the NT tissues. The synthetic COX inhibitors inhibited the growth of the TC cells. Both COX-1 and COX-2 are induced in testicular cancer, and these results indicate that both COX-1 and COX-2 are essential for the growth of TC cells.

Adult↗

PubMed2003

Tuberculous abdominal aortic pseudoaneurysm penetrating the left psoas muscle after BCG therapy for bladder cancer.

We describe a case of a 75-year-old man with abdominal aortic and right femoral tuberculous pseudoaneurysms 32 months after intravesical bacillus Calmette-Guerin therapy for bladder cancer. These aneurysms were probably brought on by systemic infection by Mycobacterium bovis. The infrarenal aorta and right common femoral artery were successfully replaced with an in situ expanded polytetrafluoroethylene graft. Tuberculous pseudoaneurysm after bacillus Calmette-Guerin therapy for malignancy is very rare, and we review the related literature.

Aged↗

PubMed2003

Antitumor effect of new local hyperthermia using dextran magnetite complex in hamster tongue carcinoma.

OBJECTIVE: This study was performed to clarify the usefulness of Dextran magnetite (DM) for the oral cancer hyperthermia. METHODS: Tumors were induced in golden hamster tongue by 9,10-dimethyl 1-1,2-benzanthracene (DMBA) application. DM suspension was locally injected into the tumor-bearing tongue and tongues were heated up to 43.0-45.0 degrees C, by AC magnetic field of 500 kHz. RESULTS: The average time taken for the temperature to rise to 43.0 degrees C or above was 162 s (n = 17) at the margin of the tumor and 420 s (n = 17) at the center of the tumor. According to the tumor volume, the time required for an increase in the central temperature of tumor to 43.0 degrees C tended to be prolonged. Both temperatures could be maintained at approximately 43.0-45.0 degrees C for 30 min. The inhibition of the growth of tongue carcinoma in the four-time heating group was significantly greater than in the control group (P < 0.01). Moreover, the survival rate was significantly higher in the heated groups than in the control group (P < 0.01). Histological examination revealed a brown uniform DM accumulation at the stroma in the margin of the tumors. Many of tumor cells disappeared at the site adjacent to this accumulation. CONCLUSION: These results strongly suggest the usefulness of this local hyperthermic system in the oral region that is accessible to this treatment.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2003

Resection surgery with neoadjuvant chemoradiotherapy improves outcomes of patients with T4 esophageal carcinoma.

The prognosis of patients with T4 esophageal carcinoma is poor, and thus an effective treatment needs to be established. The present study assessed the effect of chemoradiotherapy (CRT), postoperative morbidity and mortality, and survival time in 41 patients with T4 esophageal carcinoma. Of these, 24 received CRT followed by surgery (group A) and the remaining 17 were treated with CRT alone (group B). Postoperative complications in group A were compared with 251 patients (group C) who underwent surgery without CRT during the same period. Postoperative complications were more frequent in group A than group C (29.2% vs 8.4%, P < 0.05). The overall median survival of group A was statistically longer than that of group B (13.8 months and 3.3 months respectively, P < 0.001). Complete histologic response (grade 3) was documented in 4 group A patients (16.7%). The overall median survival of grade 3 patients was statistically longer than the rest of group A (38.9 months vs 8.8 months, P < 0.05). The data confirm that chemoradiotherapy creates tumor regression in some patients and allows resection surgery in T4 esophageal carcinoma. Moreover, surgery with CRT confers a survival advantage in T4 esophageal carcinoma.

Aged↗

PubMed2003

Reconstruction of the cervical esophagus using a free transverse colonic graft: report of a case with upper esophageal web and carcinoma.

Reconstruction of cervical esophagus and hypopharynx following cervical esophagectomy and laryngopharyngectomy is generally performed using jejunal autograft interposition. However, this method has some disadvantages and is not suitable for optimal swallowing function. In our institution, free transverse colonic graft has been successfully applied for reconstructive purposes in 12 cases since 1986. The present report describes a case of upper esophageal web accompanying superficial squamous cell carcinoma and details the operative techniques utilized.

Aged↗

PubMed2003

Laparoscopic resection of esophageal duplication cyst in an adult.

We present the case of a 26-year-old woman who underwent a successful laparoscopic resection of an esophageal duplication cyst without any other congenital abnormalities. Although computed tomography (CT) scan and endoscopic ultrasonography (EUS) both assisted in determining the correct preoperative diagnosis, the definitive diagnosis was made following pathological examination of the resected lesion.

Adult↗

PubMed2003

Small cell carcinoma of the esophagus; clinicopathological and immunohistochemical analysis of six cases.

Small cell carcinoma arising in the esophagus is a relatively rare disease. In the more common small cell carcinoma of the lung, the diagnostic significance of several new markers has been recently reported. This study used immunohistochemical techniques in addition to clinicopathological analysis, in order to clarify the utility of newer markers as biological parameters or as diagnostic tools. Six patients with small cell carcinoma of the esophagus were clinicopathologically analyzed. Immunohistochemical staining was performed using primary antibodies for bombesin, CD56 and CD57 in addition to conventional endocrine markers chromogranin A, neuron specific enolase and synaptophysin. All patients died within 2 years of surgery due to cancer recurrence, whether or not they had received adjuvant therapy. Pathological stages ranged from IIa to IVb and lymph node metastasis was observed in five cases. Of the six cases, four showed a positive reaction for bombesin and five were positive for CD57. In contrast, no cases revealed a positive reaction for CD56. The one case to survive 24 months after surgery was not shown to express bombesin, CD56 or CD57. Small cell carcinoma of the esophagus demonstrated an unfavorable prognosis. The study suggested that in this disease, bombesin and CD57 (but not CD56) were useful as biological markers, predicting clinical outcome rather than having diagnostic significance.

Aged↗

PubMed2003

Thymidine phosphorylase levels as a prognostic factor in renal cell carcinoma.

OBJECTIVE: To investigate the relationship between thymidine phosphorylase (TP), a vascular growth factor, and established prognostic factors for renal cell carcinoma (RCC), e.g. histological grade or Tumour-Node-Metastasis (TNM) classification. PATIENTS AND METHODS: TP levels were measured in RCC tissue (tumour TP) and in adjacent non-neoplastic kidney tissue (normal tissue TP), using a sandwich-type enzyme-linked immunosorbent assay. The 59 patients, diagnosed with organ-confined RCC before surgery and who had undergone radical nephrectomy, were divided into two groups according to their prognosis after surgery. Group 1 (nine patients) had a poor prognosis and group 2 (50) had no evidence of disease within a 65-month follow-up. The relationships among TP level, TNM classification, histological subtypes, V factor and prognosis, and of tumour TP to normal tissue TP levels were investigated. Multiple regression analysis was used to determine the importance of factors associated with increased TP levels. RESULTS: Normal tissue TP levels correlated with histological grade (r = 0.31, P < 0.01); in patients with venous invasion or with a poor prognosis, the levels were significantly higher than in those without (P < 0.05 and < 0.001, respectively). The normal tissue TP levels were also significantly higher in the non-clear cell than in the clear cell subtype. Multiple regression analysis showed that the independent factor associated with elevated normal tissue TP levels was histological grade (R2 = 0.189, P < 0.01). There was no correlation between tumour TP and other factors. CONCLUSION: Normal tissue TP levels in localized hypervascular RCC were associated with histological grade. These data suggest that normal tissue TP levels could be a prognostic factor.

Adult↗

PubMed2003

Vitrification of human blastocysts using cryoloops: clinical outcome of 223 cycles.

BACKGROUND: The need to cryopreserve human blastocysts is increasing. The successful birth has been reported of a baby from a blastocyst vitrified using the cryoloop technique. The present study expands on this earlier report to confirm the effectiveness of this vitrification procedure. METHODS: In patients undergoing IVF at one of three clinics, supernumerary blastocysts on day 5 or 6 at various stages of development were vitrified using cryoloops. RESULTS: Of 725 vitrified blastocysts, 583 (80.4%) survived. After the transfer of 493 blastocysts in 207 cycles, 76 women (37%) became clinically pregnant. Among these women, 21 pregnancies ended in miscarriage, 23 healthy babies were born in 18 deliveries, and 37 pregnancies are ongoing. The survival rate of day 5 blastocysts (87%) was higher than that of day 6 blastocysts (55%), but implantation rates and pregnancy rates were not statistically significantly different. CONCLUSIONS: Clinical outcomes with 725 blastocysts and 207 transfers showed that vitrification using cryoloops is effective and practical for the cryopreservation of human blastocysts. Early blastocysts on day 5 seem to be the most suitable in terms of stage and age for cryopreservation, but developed and day 6 blastocysts can also be cryopreserved.

Adult↗