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T Sakurai

Publications and source records attributed to T Sakurai.

At least 235 records · Page 13Linked to original sources
PubMed1998

Effect of macrophage colony-stimulating factor on mouse NK 1.1+ cell activity in vivo.

The effect of recombinant human macrophage colony-stimulating factor (rhM-CSF) on NK 1.1+ cell activity in vivo and in vitro was studied. An intravenous injection of rhM-CSF increased the numbers of NK 1.1+ cells in mouse spleen and blood and augmented the clearance of Yac-1 cells in vivo. Using a magnetic cell sorter (MACS), we purified NK 1.1+ cells from vehicle-injected and rhM-CSF-injected mouse spleen cells. More than 95% of the collected cells were NK 1.1 antigen-positive. NK 1.1+ cells purified from rhM-CSF-injected mouse spleen cells exhibited (a) higher cytotoxic activity against Yac-1 cells, (b) higher proliferative responsiveness to interleukin (IL)-2 and (c) a greater production of interferon (IFN)-gamma in response to IL-2 and IL-12 compared to cells purified from vehicle-injected mouse spleen cells in vitro. These results suggest that the administration of rhM-CSF increases NK 1.1+ cell numbers and activates the cells in vivo.

Animals↗
PubMed1998

Aortic stump closure with a titanium permanent clamp: a useful emergency method.

Successful aortic stump closure in a patient with Behçet's disease was accomplished with a permanent titanium clamp. In May 1990, a saccular infrarenal abdominal aortic aneurysm was detected in this patient, and prosthetic graft replacement was carried out. One year later, this graft was removed because of perigraft fluid collection; the aortic stump was sutured closed, and a right axillobifemoral bypass was done. In November 1994, the patient was admitted to the hospital because of an aortoenteric fistula. An emergency operation was performed, and the aortic stump was managed successfully with a permanent clamp. In patients with Behçet's disease, use of a permanent clamp may offer an alternative to traditional methods for closing blown-out aortic stumps.

Anastomosis, Surgical↗
PubMed1998

Inorganic and methylated arsenic compounds induce cell death in murine macrophages via different mechanisms.

We demonstrate in this study the cytotoxic effects of inorganic arsenicals, arsenite and arsenate, and organic arsenic compounds, monomethylarsonic acid (MAA), dimethylarsinic acid (DMAA), and trimethylarsine oxide (TMAO), which are metabolites of inorganic arsenicals in human bodies, using murine macrophages in vitro. Inorganic arsenicals, both arsenite and arsenate, are strongly toxic to macrophages, and the concentration that decreased the number of surviving cells to 50% of that in untreated controls (IC50) was 5 or 500 microM, respectively. These inorganic arsenicals mainly caused necrotic cell death with partially apoptotic cell death; about 80% of dead cells were necrotic, and 20% were apoptotic. The inorganic arsenicals also induced marked release of an inflammatory cytokine, tumor necrosis factor alpha (TNF alpha), at cytotoxic doses. This strong cytotoxicity of an inorganic arsenical, arsenite, might be mediated via active oxygen and protease activation because it was inhibited by the addition of some antioxidant reagents, such as superoxide dismutase (SOD), catalase, and GSH, or by a peptide inhibitor of interleukin-1 beta-converting enzyme (ICE). It is likely that these immunotoxic effects of inorganic arsenicals may evoke both immunosuppression and inflammation, and they may be central factors causing carcinogenesis and severe inflammatory responses, such as hepatomegaly and splenomegaly, in chronic arsenicosis patients who daily ingested arsenic-contaminated well water. In contrast, the cytotoxic effects of methylated arsenic compounds were lower than those of inorganic arsenicals. The IC50 value of DMAA was about 5 mM, and MAA and TMAO had no toxicity even at concentrations over 10 mM. Additionally, these methylated chemicals suppressed the TNFalpha release from macrophages. DMAA induced mainly apoptotic cell death in macrophages as indicated by cellular morphological changes, condensed nuclei, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL), and DNA fragmentation. However, the cytotoxicity of DMAA might be induced via a different mechanism from that of inorganic arsenicals because it was not abolished by the additions of SOD, catalase, or ICE inhibitor. Conversely, GSH enhanced the toxicity of DMAA. These data suggest that methylation of inorganic arsenicals in mammals plays an important role in suppression of both severe immunosuppression and inflammatory responses caused by inorganic arsenicals.

Animals↗
PubMed1998

The development of a new direct digital extra-oral radiographic system prototype using a thin-film transistor panel.

OBJECTIVE: To develop a new method of direct digital image acquisition for extra-oral radiography. METHODS: A selenium detector was combined with a thin-film transistor sensor and integrated with current technology for computed radiography in a system named Direct Radiography (DR). The effective image area of the prototype is 178 mm x 213.5 mm, and consists of a 1280 x 1536 pixel matrix with a pixel pitch of 139 microns x 139 microns. The electrical characteristics were evaluated and image quality was tested with a dried human mandible and half-skull phantom. The resultant images were subjectively reviewed by seven oral and maxillofacial radiologists. RESULTS: The prototype had a signal-to-noise ratio of 400:1 when the exposure was 250 x 10(-8) C/Kg. Spatial resolution was equal to the Nyquist frequency of 3.55 cycles/mm. The images of the phantoms were considered to be of equivalent quality to conventional screen-film images and demonstrated the normal anatomical structures used for clinical evaluation. Three to four images per minute were generated with this system. CONCLUSION: The DR system has an X-ray sensitivity comparable with a 400-speed film-screen system and appears suitable for clinical radiography. Further evaluation is therefore planned.

Humans↗
PubMed1998

Correlation of the anatomical distribution of venous reflux with clinical symptoms and venous haemodynamics in primary varicose veins.

AIM: The aim of this study was to correlate the anatomical distribution of venous reflux with clinical symptoms and venous haemodynamics in patients with primary varicose veins. METHODS: Venous reflux was examined using duplex colour Doppler ultrasonography in 266 legs in 191 patients. The venous refilling and reflux times were also measured. RESULTS: Of the 266 legs, 82 per cent had reflux in the long saphenous vein (LSV), 26 per cent in the short saphenous vein (SSV), 62 per cent had incompetent perforators (IPs) in the calf and 48 per cent had reflux in the deep veins. LSV reflux combined with SSV reflux and/or IPs was associated significantly with severe venous disease and abnormal venous haemodynamics. Femoropopliteal reflux played a role in the development of venous eczema and ulcers when combined with superficial venous reflux. CONCLUSION: Patients at high risk of developing complications of venous disease may be identified by an accurate non-invasive evaluation of reflux patterns.

Adolescent↗
PubMed1998

Intracellular Signal-transducing elements involved in transendothelial migration of lymphoma cells.

To investigate the molecular mechanisms underlying transendothelial migration of tumor cells, an essential process for their hematogenous dissemination, we developed an in vitro model system that allows the separate monitoring of cell adhesion and transmigration processes. This system uses a human pre-B lymphoma cell line, Nalm-6, and a cultured mouse endothelial cell line, KOP2.16. Nalm-6 cells rapidly adhered to KOP2.16 and subsequently transmigrated underneath them. Using this model, we examined the effects on transendothelial migration, of various reagents which specifically interfere with the function of intracellular signal transduction molecules. Treatment of Nalm-6 cells with wortmannin (WMN), herbimycin A, pertussis toxin, or C3 exoenzyme of Clostridium botulinum, which specifically inhibit P13 kinase and/or myosin light chain kinase, herbimycin-sensitive tyrosine kinases, heterotrimeric G proteins, and the small G proteins, and the small G proteins rho/rac, respectively, reduced transmigration in a dose-dependent manner, Pretreatment of KOP2.16 endothelial cells with WMN also reduced transmigration in a dose-dependent manner. Binding of Nalm-6 binding to KOp2.16 was not affected, even when Nalm-6 or KOP2.16 cells were pretreated with these inhibitors, indicating that the reduction of transmigration was not due to a reduction of Nalm-6 to KOP2.16. These results also indicate that the signal transduction pathway(s) involved in transmigration can be dissociated from that of adhesion. Our results support the notion that endothelial cells are not a passive barrier in lymphoma extravasation, but that they assist lymphoma cell extravasation.

Androstadienes↗
PubMed1998

Extensive intraductal component (EIC) and estrogen receptor (ER) status in breast cancer.

The extensive intraductal component (EIC) of primary breast carcinoma is a special spread pattern observed in the breast. Extensive intraductal component may extend diffusely over the entire breast. Therefore, EIC is considered to be an important risk factor for local recurrence in breast-conserving therapy. However, the pathogenesis of EIC remains uncertain. Whether or not the estrogen receptor (ER) has an influence on its biologic behavior has not been fully studied. A consecutive series of 142 breast carcinomas submitted to the pathology department were examined on step gross sections of 5.0 mm thick. Extensive intraductal component was determined and divided into three types. Estrogen receptor was examined using both immunohistochemistry (ER-IHC) and enzyme immunoassay (ER-EIA). Extensive intraductal component was found in 78 of 138 (56.52%) invasive carcinomas including invasive ductal carcinoma with a predominant intraductal component. Estrogen receptor-IHC positivity was 42.96% (61/142) in the invasive breast carcinoma. Estrogen receptor positivity showed no significant difference between EIC-positive and -negative cases, as well as between EIC and invasive main tumor in the EIC-positive cases. But within the EIC-positive group, ER positivity was found to be higher in the peripheral type of EIC-II and EIC-III than in the central type of EIC-I (P < 0.05). Although ER may not play an essential role in the pathogenesis of EIC, it has shown some significance in the development of peripheral type EIC because of its higher presence in the peripheral type of EIC-II and EIC-III than in the central type of EIC-I.

Antibodies, Monoclonal↗
PubMed1998

Sarcomatoid renal cell carcinoma with chromophobe cell foci. Report of a case.

We report a case of sarcomatoid renal cell carcinoma with chromophobe cell foci. The patient was a 57-year-old Japanese woman with a renal mass measuring 12x8x8 cm in diameter. Histologically, the tumor was composed predominantly of sarcomatoid renal cell carcinoma with foci of chromophobe cell carcinoma. The patient died of multiple metastases 2 months after operation. To the best of our knowledge, there have been only two reports of the coexistence of sarcomatoid renal cell carcinoma and chromophobe renal cell carcinoma in the literature. Our case indicates that chromophobe cell carcinoma may be connected with sarcomatoid renal cell carcinoma. In such a case, the prognosis may be related to the latter component.

Adenocarcinoma↗
PubMed1998

Attenuation of renal ischemia-reperfusion injury in rats by allopurinol and prostaglandin E1.

50 Sprague-Dawley rats were used to study the effect of allopurinol and prostaglandin E1 (PGE1) on renal ischemia-reperfusion injury. They underwent left renal ischemia for 1 h and reperfusion. A right nephrectomy was performed, and 5 groups were made. Group AP received allopurinol 50 mg/kg and PGE1 20 micrograms/kg; group A, allopurinol; group P, PGE1; group C, control, and group S, sham group. Five animals from each group were used to study renal functions and 5 for renal histology. The serum creatinine values were lower in the treatment groups compared to the controls on days 1-3 and 7 (p < 0.05). The blood urea nitrogen values showed a similar trend. Maximum histological damage was seen in group C, followed by groups A, P and AP, in this order. We conclude that allopurinol and PGE1 attenuate renal ischemia-reperfusion injury in rats.

Allopurinol↗
PubMed1998

Presence of 22- and 17-kDa proteins reacting with sera in mice experimentally infected with Brachyspira (Serpulina) hyodysenteriae.

The antibodies to B. (S.)hyodysenteriae in experimentally infected mice were detected by microscopic agglutination test (MAT) and enzyme-linked immunosorbent assay (ELISA). The reactions in MAT were serotype specific while those in ELISA were common to both strains. A further investigation with immunoblotting technique demonstrated that 22- and 17-kDa proteins reacted strongly with the sera. The proteins in ATCC 27164 strain strongly reacted with the serum from ATCC 31212 strain-infected mouse and vice versa. These proteins were sensitive to proteinase K.

Animals↗
PubMed1998

Acute terminal pancreatitis occurring in jejunal heterotopic pancreas.

CONCLUSION: We report a unique case of acute terminal pancreatitis occurring in the jejunal heterotopic pancreas. Unlike previously reported cases, acute pancreatitis was not found histologically in the ordinary pancreas. BACKGROUND: Heterotopic pancreas may show the same inflammatory or neoplastic changes, such as acute pancreatitis and adenocarcinoma, as those that occur in the ordinary pancreas. However, histologically proven acute pancreatitis occurring in heterotopic pancreas is very rare and only three reports have been described. METHODS: A 53-yr-old Japanese man died of hepatic failure, and autopsy was performed. RESULTS: Autopsy incidentally revealed heterotopic pancreas of the jejunum. Microscopically, focal acute pancreatitis was observed in the jejunal heterotopic pancreas, whereas the pancreas of the normal location showed no abnormality. In addition, no clinical evidence of pancreatic disease was noted before death. Therefore, we diagnosed this case as acute terminal pancreatitis occurring in the jejunal heterotopic pancreas.

Acute Disease↗
PubMed1998

High-temperature, nonradioactive primer extension assay for determination of a transcription-initiation site.

We have developed a simple and safe method for the determination of a transcription-initiation site. In this method, reverse transcriptase of the avian myeloblastosis virus or rTth DNA polymerase from Thermus thermopilus was used with a fluorescein isothiocyanate (FITC)-labeled primer. The primer-extension reaction can be performed at a high temperature, which reduces the hindering effect of the secondary structure in RNA, and can omit the annealing step between RNA and the primer. Almost all steps can be done in one tube. This procedure can provide reliable and reproducible data when compared with the conventional procedure at low temperature. Moreover, the sequencing ladder that is required for determining the position of extended products can be obtained with the same FITC-labeled primer.

DNA↗
PubMed1998

Effect of macrophage colony-stimulating factor (M-CSF) on mouse immune responses in vivo.

We examined the effects of recombinant human M-CSF (rhM-CSF) on mouse macrophages and immune responses in vivo. Intraperitoneal administration of rhM-CSF (20-500 microgram/ml) increased Mac-1+ cell numbers in the peritoneal cavity. The tumoricidal activities of the macrophages from vehicle-administered (V-M phi) and from rhM-CSF-administered (M-M phi) mice were the same as those observed in vitro. However, when activated by lipopolysaccharide (LPS), the tumoricidal activity of M-M phi was stronger than that of V-M phi. Intravenous administration of rhM-CSF (500 micrograms/gk) increased the number of spleen cells. Flow cytometric analysis showed that administration of rhM-CSF increased Mac-1+, B220+ and NK 1.1+ cell counts in the spleen. However, CD4+ and CD8+ cell numbers did not change. Concomitant increases were observed in levels of IL-4 and IL-10 in mouse serum following rhM-CSF administration, but no significant changes were observed in the serum level of IFN-gamma. In experiments involving mouse immune responses, the administration of rhM-CSF reduced the contact sensitivity (CS) reaction against picryl chloride (PC) and augmented IgE production in response to 2,4-dinitrophenyl (DNP), but did not affect the production of either IgM or IgC1. These results suggest that administration of rhM-CSF not only activates murine macrophages, but modulates antigen-specific immune responses in vivo.

Animals↗
PubMed1998

[Evaluation of theophylline in children hospitalized with asthma attack].

The purpose of this study is to determine whether theophylline provides clinical benefits in the hospitalized children with asthma attack. Aminophylline was intravenously given to the 50 patients (Group A) who were admitted 1994. A small dose of aminophylline compared to that of Group A was given to the 44 patients (Group B1) who were admitted 1998. On the other hand, aminophylline was not given to the 12 patients (Group B2) who were admitted 1998. However, there were no differences among those groups in the duration of admission, in the total dose of intravenously given methylprednisolone, and in the improvement of clinical score of asthma. These results suggested that there was no clinical benefit in using theophylline for treatment to hospitalized children with asthma attack combined high fever.

Aminophylline↗
PubMed1998

[A tuberculosis epidemic among four relatives who live in the neighborhood of index case].

A tuberculosis epidemic occurred among 4 relatives who live in the neighborhood of the index case. A thirty-three year old female was admitted to a hospital in July 1994 with high fever and cervical lymphoadenopathy. Culture examination of her sputum was positive for acid-fast bacilli and her chest X-ray showed diffuse small nodules. During the following sixteen months, five new patients with pulmonary tuberculosis were found among the relatives who lived in the neighborhood of the index case. The contact examination was first limited in her own family members, however, after detection of the second case, the examination was extended to other relatives living nearby, and another four patients were found. The results of PPD skin test of ten contact children showed strongly positive reaction, and chemoprophylaxis was indicated. Contacts examination is very important especially for patients with highly infectious tuberculosis.

Adolescent↗
PubMed1998

[MPO-ANCA related diffuse alveolar hemorrhage].

The purpose of this study was to elucidate the clinical features characterizing patients with myeloperoxidase specific-antineutrophil cytoplasmic antibody (MPO-ANCA) related diffuse alveolar hemorrhage (DAH). Seventeen MPO-ANCA-positive patients were evaluated. Nine patients (52.9%) had pulmonary involvement; of those, 6 (35.3%) had DAH, and 4 (23.5%) had interstitial pneumonia (1 patient had both pulmonary diseases). Three of the patients with DAH demonstrated only mildly bloody sputum. All patients with DAH had increased peripheral white blood cell counts, high titers of C-reactive protein and MPO-ANCA, and marked microscopic hematuria. DAH was diagnosed in all cases by fiberoptic bronchoscopy with bronchoalveolar lavage. All patients with DAH were treated with three pulses of methylprednisolone, and 5 were treated with cyclophosphamide. Three of the patients with DAH required mechanical ventilation for respiratory insufficiency, but 2 were relieved of that need by immunosuppressive therapy. In spite of intensive care, 1 patient died of respiratory failure and 2 died of complications related to therapy. The prognosis for patients with DAH is poor. We emphasize the importance of prompt and accurate diagnoses and aggressive care, including immunosuppressive therapy, mechanical ventilation, and hemodialysis. In addition, extra precautions should be taken against opportunistic infections such as Pneumocystis carinii pneumonia.

Aged↗
PubMed1998

University medical information network--past, present, and future.

The University Medical Information Network (UMIN), established in 1989, is a network service organization for national university hospitals in Japan. It has provided various medical information services to medical professionals, including database, electronic mail, and news services. Although its initial network was constructed as a closed network using N1 protocol, it now adopts TCP/IP protocol and is open to other medical professionals via the Internet. The next UMIN network system is planned to be constructed as a secure virtual closed network on the Internet, using cipher technology, and to provide secure information services to national university hospitals via the closed network, and to other medical professional via the Internet. User friendly interface and flexible system development were made possible by adopting TCP/IP, and the number of users dramatically increased accordingly. However, the database, software design, and human organizations developed in the N1 era have now proven to be of great value, and contribute to todayís flourishing state of the UMIN.

Computer Communication Networks↗