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Biomedical subjects

N Sato

Publications and source records attributed to N Sato.

At least 433 records · Page 24Linked to original sources
PubMed1999

Effect of magnesium sulfate pretreatment and significance of matrix metalloproteinase-1 and interleukin-6 levels in coronary reperfusion therapy for patients with acute myocardial infarction.

Magnesium (Mg) inhibits the influx of calcium in vascular smooth muscle cells. The purposes of this study were to test the hypothesis that an intravenous administration of magnesium might effect the complement response and to determine the effects of a magnesium pretreatment of patients with acute myocardial infarction (AMI) on the incidence of reperfusion injuries. Thirty-eight AMI patients were treated with coronary reperfusion therapy within 6 hours of onset. They were randomly divided into two groups: group pretreated with intravenous magnesium sulfate (0.27 mmol/kg) (magnesium group, n = 19), and nonpretreated controls (placebo group). The reperfusion injuries observed within 1 hour after the coronary reperfusion included arrhythmias, aggravated chest pain, and ST segment elevation in 12-lead electrocardiograms. Coronary recanalization was performed in 36 patients. The incidence of reperfusion arrhythmia was significantly lower in the magnesium group than in the placebo group (17% vs 78%, p<0.001). At the postreperfusion stage, there was a tendency for the degree of ST segment reelevation in the magnesium group lower than in the placebo group (2.5 +/- 2.3 mm vs 4.7 +/- 3.8 mm, p = 0.07). No marked difference was observed in the incidence of chest pain aggravation between the two groups (67% vs 73%, ns). The peak serum levels of interleukin-6 (IL-6) were significantly lower in the magnesium group than those in the placebo group (38.9 +/- 25.0 vs 92.3 +/- 76.5 pg/mL, p = 0.016). The peak serum levels of matrix metalloproteinase-1 (MMP-1) were lower than those in the placebo group (16.2 +/- 4.8 vs 19.7 +/- 9.0 ng/mL, p = 0.09), but the difference was not significant. A positive correlation was observed between the peak MMP-1 values and the peak IL-6 values (r = 0.57, p = 0.001) in all patients. Increased serum ionized Mg2+ may inhibit arrhythmic recurrence and the production of IL-6 and MMP-1 after reperfusion and prevent the increase of myocardial lesions caused by calcium overload on myocytes. The increased IL-6 production may induce MMP-1, leading to tissue organ injury. Pretreatment with magnesium sulfate may protect the myocardium of AMI patients from reperfusion injuries.

Adult↗
PubMed1999

Characteristics of intracardiac potentials at successful ablation sites in concealed Wolff-Parkinson-White syndrome.

The authors investigated bipolar electrograms recorded from the catheter tip at the actual successful ablation sites in 22 consecutive patients with concealed Wolff-Parkinson-White syndrome to clarify the characteristics of the potentials indicating the optimal site for catheter ablation. In all patients the retrograde transaortic approach to their left-sided accessory pathways, and a temperature-controlled (60 degrees C) energy delivery, were performed. The authors assumed that a shorter dissociation time (time from energy delivery to ventriculoatrial conduction dissociation) indicated more accurate catheter mapping. A significant negative correlation (r = 0.527, p < 0.05) between the AV ratio (ratio of the amplitudes of the atrial to ventricular potentials) recorded at the ablation catheter tip and the dissociation time was observed. When the AV ratio and the dissociation time were compared among the groups classified according to the corresponding Npeak (the number of positive potential peaks in the electrogram obtained from the ablation catheter tip during right ventricular apical pacing) value, they differed significantly (p < 0.05 and p < 0.01, respectively), ie, a higher AV ratio and a shorter dissociation time related to a multipeak electrogram from the ablation catheter tip. The authors conclude that the atrial insertion site of the accessory pathway, exhibiting a multipeak complex electrogram that may represent nonuniform anisotropic characteristics, is an adequate ablation site.

Action Potentials↗
PubMed1999

Improving the oral bioavailability of albendazole in rabbits by the solid dispersion technique.

We have investigated the oral bioavailability of granules of albendazole, a drug used for treating echinococcosis in man, prepared by the solid dispersion technique. Rapid dissolution and supersaturation were observed when hydroxypropylmethylcellulose and hydroxypropylmethylcellulose phthalate were used as carriers in the solid dispersion. They inhibited the crystallization of albendazole from the supersaturated solution and maintained an amorphous state for 8 h. Gastric acidity-controlled rabbits were used to evaluate the variation in absorption after oral administration of the albendazole solid dispersion. For rabbits with low gastric acidity the bioavailability of orally administered albendazole in the granular form prepared by solid dispersion was more than three times that of albendazole in physical mixtures. These results suggest that the bioavailability of albendazole in solid dispersions might be high even if there is a great variation in the gastric pH of patients.

Administration, Oral↗
PubMed1999

Protamine induces elevation of cytosolic free Ca2+ in cultured porcine aortic endothelial cells.

To test the hypothesis that protamine influences calcium movement in endothelial cells, we measured the concentration of intracellular free calcium ([Ca2+]i) in cultured porcine aortic endothelial (PAE) cells in Krebs solution (2.5mM Ca2+, pH 7.4) at 37 degrees C, by fura-2 fluorimetry. The basal [Ca2+]i of PAE cells was 113+/-18 nM (n=6). Protamine increased [Ca2+]i in a concentration-dependent manner (EC50, the concentration having 50% of the maximum effect, 1.4+/-0.3 microg mL(-1), n=6). The response of PAE cells to 100 microg mL(-1) protamine (330+/-80 nM, n=6) was blocked by a Ca2+ chelator, 5 mM glycoletherdiaminetetraacetic acid (EGTA; 131+/-16 nM, n=6), and by a non-selective Ca2+ channel blocker, 3 mM Co2+ (134+/-14 nM, n=6). These results suggest that Ca2+ influx through cell-membrane Ca2+ channels is mainly responsible for the protamine-induced Ca2+ elevation.

Animals↗
PubMed1999

Bacillus cereus dissociates hemoglobin and uses released heme as an iron source.

B. cereus can use hemoglobin, heme, and heme-albumin complex as iron sources, but does not use other iron binding proteins such as transferrin and lactoferrin. B. cereus digests heme-protein complexes and elicits heme release from the proteins, but does not digest transferrin and lactoferrin. Dissociation of heme-proteins corresponded to the use of iron sources by B. cereus. This activity was completely inhibited by EDTA and phosphoramidon, and metalloendopeptidase inhibitors, therefore it appeared that the metalloprotease(s) are related to digestion and use of heme-protein complexes by B. cereus. B. cereus could bind released heme to its cells. These findings suggest that B. cereus can dissociate heme from heme-protein complex, and capture the released heme to use as an iron source.

Bacillus cereus↗
PubMed1999

Lactoferrin inhibits Bacillus cereus growth and heme analogs recover its growth.

The growth of Bacillus cereus was markedly inhibited by the addition of lactoferrin and was recovered by the addition of FeCl3. The growth inhibition was also reversed by the addition of erythrocytes and hemoglobin. B. cereus can use heme or heme-protein complex (hemoglobin-haptoglobin and hematin-albumin complexes) as iron sources in iron deficient conditions. Therefore, B. cereus uses these heme or heme-protein complexes to prevent the growth inhibition of lactoferrin in vivo.

Bacillus cereus↗
PubMed1999

The significance of NSE and CEA as a differentiation marker for the cellular heterogeneity of small cell lung cancer.

Neuron-specific enolase (NSE) and carcinoembryonic antigen (CEA) levels in the culture supernatant of the 65 pulmonary carcinoma cell lines: Small cell lung cancer (SCLC) 18, large cell carcinoma 14, squamous cell carcinoma 14, adenocarcinoma 14 and adenosquamous cell carcinoma 5, were measured by a radioimmunoassay (RIA). The mean value of NSE was 30.8+/-22.4 ng/ml and 9.2+/-8.7 ng/ml in SCLC and non-SCLC, respectively. The mean value of CEA was 15.1+/-20.9 ng/ml and 26.6+/-72.3 ng/ml in SCLC and non-SCLC, respectively. A significant difference in NSE levels was obtained between SCLC cell lines and non-SCLC cell lines. In SCLC cell lines, a significant inverse proportional correlation was observed between NSE and CEA levels. The CEA production tended to be higher in cells with low levels of NSE than in those with high NSE production. With respect to correlation between marker production and growth characteristics of SCLC cells in vitro, significantly higher NSE and lower CEA levels were found in cells growing with floating colony or neurite like characteristics (classic cell type) than those in cells with epithelial or intermediate growth characteristics (variant cell type). A significant positive correlation between NSE levels and the survival periods was found in follow-up studies of 10 patients who underwent surgery with complete resection of the primary tumor. All of 4 long term survivors over 3 years after surgery had significantly high NSE and relatively low CEA producing tumors. The relationship of these markers to clinical status of the patient suggests that an analysis for correlation of NSE and CEA levels in SCLC patients may be useful to discriminate between a pure neuroendocrine SCLC tumor and a mixed small cell/large cell tumor, and in monitoring therapeutic effect and prognosis of each patient.

Adult↗
PubMed1999

Primary biliary cirrhosis associated with painless thyroiditis.

A case of anti-mitochondrial antibody (AMA)-negative primary biliary cirrhosis (PBC) associated with painless thyroiditis is reported in a 47-year-old woman who diagnosed as PBC based on her elevated serum gamma-glutamyl transpeptidase and immunoglobulin M levels, as well as histological findings of destroyed bile ducts surrounded by mononuclear infiltrates in the biopsied liver. She was negative for AMA and had a depressed level of thyroid-stimulating hormone accompanied by increased free thyrosine, thyroxine and triiodothyronine levels and low titers of anti-microsomal and anti-thyroid peroxidase antibodies. Her thyroid disorder corresponded with painless thyroiditis. An association between PBC and hyperthyroidism is rare. Furthermore, an association between AMA-negative PBC and hyperthyroidism due to painless thyroiditis has not previously been reported.

Autoantibodies↗
PubMed1999

Tissue expression of the S100 protein family-related MRP8 gene in human chorionic villi by in situ hybridization techniques.

The present study examined the tissue-expression of MRP8 in human placenta using a biotinylated DNA-probe for in situ hybridization. During the first and second trimesters high level and synchronous expression of MRP8 was detected in cytotrophoblasts (Langhans' cells), placental-tissue macrophages (Hofbauer cells), fibroblast-like cells, endothelial cells and monocytic lineages in the foetal capillaries. The highest expression was seen in large and oval-shaped cytotrophoblasts and stromal-cell populations at around 8-11 weeks. At term placentas had low level MRP8 expression chiefly in the myelomonocytic lineages in foetal blood vessels. The peripheral monocytes in the maternal space also expressed MRP8 at high levels during the first and second trimesters, which subsequently decreased at term. We suggest three hypotheses based on these results; (1) The initial expression of MRP8 may occur in two cell lineages of extra-embryonic and intra-embryonic origin in the first two trimesters; (2) the cytotrophoblasts, placental-tissue macrophages and fibroblasts may play important roles in the production of placental hormones and the immuno-regulation of foetal acceptance; and (3) MRP8-expression may be synchronously inhibited once the trophoblasts and stromal cell-constituents have differentiated in the chorionic villi.

Antigens, Differentiation↗
PubMed1999

A pilot study of a response oriented chemotherapeutic regimen combined with autologous peripheral blood progenitor cell transplantation in aggressive non-Hodgkin's lymphoma.

Fourteen consecutive patients with poor-risk aggressive NHL who at presentation had any one of four risk factors underwent response oriented induction chemotherapy and successive high-dose chemotherapy followed by autologous PBPC transplantation. After treatment with three cycles of conventional CHOP with G-CSF support (CHOP-G), the response was evaluated. For patients who achieved a complete remission (CR), an additional three cycles of CHOP-G were administered, while for partial response patients, another induction regimen including some non-cross-resistant agents was given; three cycles of VIPDexa-G (etoposide, ifosfamide, cisplatinum and dexamethasone) +/- two cycles of ENAP-G (mitoxantrone, etoposide, cytosine arabinoside and prednisone), were given. The scheduled induction chemotherapy, was followed by treatment with a high-dose cytoreductive regimen followed by autologous PBPC transplantation. After three cycles of CHOP-G, four patients (29%) achieved a CR, and 10 (71%) achieved a partial response (PR). When all scheduled induction therapy was completed, 10 patients (71%) had a CR. All 14 patients received high-dose therapy and obtained a complete hematologic recovery, except for one with a bone marrow relapse two months after transplantation. Evaluation of response after high-dose therapy showed 12 CRs (86%) which included three additional CRs, one PR, and one toxicity-related death. With a median follow-up of 12 months (range, 4 to 40), 12 are alive, with 11 in continuous first CR, and one relapse. The 2-year overall survival (OS) rate and event-free survival (EFS) rate are 77% and 79%, respectively, while the disease-free survival (DFS) rate is 92%. In conclusion, this pilot study suggests that response oriented induction chemotherapy and successive high-dose chemotherapy followed by autologous PBPC transplantation is commendable and can be associated with a high rate of remission and DFS for poor risk subjects with aggressive NHL.

Adolescent↗
PubMed1999

[Genetic analysis of candidate gene polymorphisms in elderly hypertension].

Recent developments in molecular biological techniques allowed us to examine the genetic risk factors responsible for essential hypertension. The candidate gene approach revealed that several gene polymorphisms increase the relative risk for hypertension. Most genetic studies, however, examined only young subjects but not elderly ones. To examine the importance of gene polymorphisms in elderly hypertension, we carried out a case-control study and compared the odds ratio for hypertension between young (< 60) and elderly (> or = 60) subjects. The participants of this study were recruited from the outpatients of Osaka University Medical School with informed consent. We examined the following polymorphisms as candidates: the angiotensinogen (AGT/M235T), angiotensin converting enzyme (ACE I/D), angiotensin II type 1 (AT1/A1166C) and type 2 (AT2/C3123A) receptors, alpha-adducin (adducin/Gly460Trp), methylenetetrahydrofolate reductase (MTHHR/C677T), and apolipoprotein (apoE/epsilon 4, apoE/T-491A). In young subjects, the AGT/T235 allele significantly increased the odds ratio for hypertension but not in elderly subjects. In young males, the AT2/A3123 allele was also associated with hypertension but not in females or in elderly subjects. Other associations between polymorphism and hypertension did not reach a significant level. To sum up, it was revealed that some polymorphisms increase the susceptibility for hypertension but others do not, which suggests that there is heterogeneity in the genetic involvement of polymorphism due to aging.

Aged↗
PubMed1999

In vitro and in vivo effects of exogenous nucleotides on the proliferation and maturation of intestinal epithelial cells.

To determine the nutritional role of nucleotides, the in vitro and in vivo effects of exogenous nucleotides on the development of intestine were investigated. First, the in vitro effects of nucleotides on the proliferation and maturation of enterocytes were studied by using a human colon tumor cell line (Caco-2) and a rat normal small intestinal crypt cell line (IEC-6). Second, the in vivo effects of nucleotides were also studied in early weaned rats fed nucleotide-unsupplemented or high-nucleotide-supplemented diet. Nucleotide composition resembled that of human milk (CMP:UMP:AMP:IMP:GMP = 10:1:1:1:1, in weight). Nucleotide supplement did not enhance Caco-2 cells proliferation; however, it significantly enhanced maltase and sucrase activities. In contrast, nucleotides supplement enhanced ICE-6 cells proliferation and maltase activity. CMP, predominantly contained in the mixture, enhanced most effectively the proliferation and maturation of cells. In the in vivo experiment, nucleotides significantly enhanced sucrase activity in the intestinal mucosa of early weaned rats. The results presented here suggest that a nucleotide supplement may enhance enterocyte proliferation and/or maturation in vivo and in vitro. Therefore exogenous nucleotides may play an important role in the development of the intestine.

Adenosine Monophosphate↗
PubMed1999

[Analysis of outcome of free jejunal-autograft for head and neck reconstruction--postoperative complications and functional results of swallowing in 49 cases].

We evaluated postoperative results in 49 patients (39 men, 10 women) who underwent pharyngoesophageal reconstruction with free-jejunal autograft following total pharyngolaryngoesophagectomy in the Department of Otolaryngology, Hokkaido University School of Medicine from 1989 to 1997. Evaluation was performed regarding the following points: 1) postoperative complications, 2) factors that determine the functional results of swallowing, 3) relation between forms of jejunal anastomosis and swallowing. The primary malignancy site was hypopharynx (39), cervical esophagus (4), larynx (3), thyroid (2) and trachea (1), Reconstructions were made with free jejunal autograft alone in 45 cases and with free jejunum in combination with gastric pull-up in 4. In patients who underwent reconstruction with jejunum alone, the anastomosis of the jejunum to the pharynx was performed in side-to-end fashion in 22, end-to-end in 18 and rho-shaped in 4. In the 1 remaining case, we used jejunal-patch graft. Postoperative complications including minor or nongraft related, occurred in 24 of 49 (49.0%) patients. Among these, graft-related complications were graft failure in 1 (2.0%), fistula formation in 3 (6.1%) and graft stricture in 2 (4.0%). Re-operations were required in one case of graft failure and 2 of fistula formation. Consequently, the overall graft-survival rate was 98.0% (48/49). Therefore, we considered the method of reconstruction to be a reliable procedure with a high-success rate. The swallowing function after reconstructive surgery was studied in 35 patients who underwent side-to-end (18) and end-to-end (17) anastomosis of the jejunum to the pharynx. We indicated that appropriate tension in the jejunum was the most important factor for adequate swallowing function. The end-to-end group had a higher rate of taking normal diet compared with the side-to-end group. The rate of swallowing dysfunction was only 5.9% (1/17) in the end-to-end group. On the other hand, 4 of 18 (22.2%) cases in the side-to-end group were regarded as having poor swallowing function. As a result we considered the end-to-end proximal jejunal anastomosis to be the more desirable form.

Adult↗
PubMed1999

[Experience with surgery for congenital esophago-bronchial fistula with esophageal diverticulum in adult].

A 65-year-old female was admitted into our department with complaint of bloody sputum. An upper G-I series examinations and thoracic CT demonstrated an esophago-bronchial fistula with diverticulum located between the mid-esophagus and right B6. Following postero-lateral thoracostomy, the fistula was surgically removed and right lower lobectomy was carried out. No inflammatory changes were found in the surrounding tissues of the fistula and the diverticulum. Histological examination revealed that the fistula wall contained squamous epithelium and muscularis mucosa. These results suggested that this case was congenital esophago-bronchial fistula categorized as Braimbridge type I.

Aged↗
PubMed1999

The relationship of glycosylation and isoelectric point with tumor accumulation of avidin.

UNLABELLED: Radiolabeled avidin markedly accumulated in intraperitoneal tumors and was cleared rapidly from circulation when given intraperitoneally. This study investigated the mechanisms of the tumor localization of avidin. METHODS: Avidin was deglycosylated through endoglycosydase-H digestion and/or neutralized by acetylation of its lysine amino acids with acetic acid N-hydroxysuccinimide ester. Avidin and modified avidins were analyzed using sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS/PAGE) and isoelectric focusing. A tumor model was established by intraperitoneal injection of human colon cancer cells, LS180, in nude mice. Avidin and modified avidins were labeled with 111In using diethyleneamine pentaacetic acid-biotin and were administered intraperitoneally into the tumor-bearing mice. The biodistribution of radioactivity was examined 2 and 24 h postinjection. RESULTS: Deglycosylated avidins revealed a major band of smaller molecules on SDS/PAGE. The isoelectric point of neutralized avidins was reduced to less than 5, whereas that of unneutralized avidins was more than 9.5. Biodistribution study demonstrated that liver uptake was decreased by deglycosylation and kidney accumulation was decreased by neutralization, respectively. The blood clearance was remarkably slowed by combined modification of deglycosylation and neutralization. The tumor uptake of radioactivity was reduced by either deglycosylation or neutralization and was further decreased with combined modification. CONCLUSION: Both high glycosylation and positive charge of avidin contributed to its accumulation in tumor. This study may facilitate development of a new vehicle for the delivery of therapeutic agents to intraperitoneal tumors.

Animals↗
PubMed1999

[Echinococcosis].

Explore the source record for details and available documents.

Albendazole↗
PubMed1999

[A case of AIDS complicated by progressive outer retinal necrosis].

BACKGROUND: The retina may be involved in patients with acquired immunodeficiency syndrome (AIDS). Progressive outer retinal necrosis (PORN) is a liability. CASE: A 46-year-old female had repeated exacerbations of pulmonary tuberculosis since two years before. Herpes zoster developed in her right trigeminal nerve area two weeks before, leading to a diagnosis of AIDS. She was referred to us for ophthalmological evaluation. FINDINGS: Both eyes showed numerous yellowish white patches in the deeper retinal layers. The anterior chamber and the vitreous were almost intact. Herpes zoster virus was identified in the acqueous by the polymerase chain reaction (PCR) method. Systemic acyclovir or ganciclovir failed to prevent rapid extension of fundus lesions, resulting in whole-layer necrosis of the retina. Retinal detachment with multiple breaks developed in both eyes whthin eleven days after the patient was first seen by us. The clinical course was different from acute retinal necrosis and was characteristic of PORN. CONCLUSION: This case illustrates that PORN may develop in patients affected by AIDS.

AIDS-Related Opportunistic Infections↗