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Biomedical subjects

T Matsui

Publications and source records attributed to T Matsui.

At least 1,207 records · Page 67Linked to original sources
PubMedDate not supplied

A new method to detect systemic inflammatory response syndrome by continuous monitoring system: an experimental study in rats.

A continuous monitoring system was designed for detection of systemic inflammatory response syndrome (SIRS) using spectrum analyser and local temperature mapping system with deep body thermometer. This method demonstrated significant increases of heart and respiratory rates and deep body temperature from normal levels within 120 minutes after lipopolysaccharide administration in rats. Our monitoring system appears promising for clinical detection of SIRS in the early stages to prevent multiple organ failure.

Animals↗
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Non-invasive estimation of arterial blood pH using exhaled CO/CO2 analyser, microwave radar and infrared thermography for patients after massive haemorrhage.

In order to conduct non-contact estimation of arterial blood pH after massive haemorrhage, we calculated the arterial pH based on linear-regression analysis of exhaled gas concentrations (CO and CO2) and vital signs (heart rate, respiratory rate, and surface temperature) measured using non-contact methods in hypovolemic animals.

Acidosis↗
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A new thermal shape memory Ti-Ni alloy stent covered with silicone.

An attempt was made to develop an airway stent for nonsurgical transluminal implantation using a bronchofiberscope. The stent is composed of a single wire with a diameter of 0.5 mm. The wire is made of thermal shape memory titanium nickel alloy, with a transition temperature of 25-30 degrees C. To avoid direct contact between the metal and the tissue, the wire is covered with a 300 microns thick coating of silicone. The stent is horseshoe shaped in cross-section. It is 15 mm in outer transverse diameter and 40 mm long. Ten stents were implanted in 10 dogs whose tracheal cartilages had been previously broken. The stents were first cooled in ice water to reduce their diameter and then inserted into the target site. The wire was warmed to body temperature and recovered its initial shape within 10 sec. The dogs were killed for examination between 1 week and 6 months after implantation. All the stents were located at the implantation sites and were patent. Tissue reactions, such as ulceration and granulation formation, were less severe than in those with previously implanted non-silicone covered stents. Microscopic observation showed that the wires became gradually covered with epithelium within 2 months. This transluminal technique for preserving airway patency shows promise for clinical application.

Alloys↗
PubMedDate not supplied

Clinical evaluation of the Gyro Pump C1E3 as a cardiopulmonary bypass pump.

The Gyro Pump C1E3 is a new centrifugal pump with numerous features, including a ceramic pivot bearing system, secondary vanes, and an eccentric inlet port. To evaluate its biocompatibility, antithrombogenicity, and produced hemolysis, we used the Gyro Pump during cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG) cases to compare it with the BioMedicus pump. From September 1998 to February 1999, 30 consecutive patients underwent CABG under conventional CPB. Fifteen patients were supported by the Gyro Pump C1E3 (Group G), and the remaining 15 patients, by a BioMedicus BP-80 pump (Group B). In both groups, flow rate was equivalent. Blood samples were taken as follows: preoperative, 60 minutes after the end of the procedure, and at postoperative days (POD) 0, 1, and 2. We evaluated the plasma free hemoglobin (free Hb) as an indication of hemolysis; beta-thromboglobulin (beta-TG) and platelet factor four (PF-4) as an indication of platelet deterioration; C3, C4, CH50 for complement activation; coagulation parameters, fibrinolytic factor, thrombomodulin, nitric oxide (NO), and endothelin as an indication of endothelial deterioration. This was the first clinical sized Gyro Pump CIE3. De-airing from the pump was easily accomplished via the eccentric oblique inlet port. The system, including its console, was easily and simply controlled. Perioperative laboratory data were not markedly changed in either group with demonstrated equivalence for biocompatibility and hemolysis. After pumping, no thrombus formation or pivot wear were observed inside the pump. This atraumatic, small centrifugal pump appears well suited not only for CPB but also for circulatory support.

Aged↗
PubMedDate not supplied

Spondylolysis of the axis. Report of four cases.

Spondylolysis or spondylolisthesis of the cervical spine, especially of the upper cervical spine, is very rare. The authors report four cases of spondylolysis of the axis and outline its roentgenographic features for differential diagnosis. The clinical course of the cases and the unvarying roentgenographic findings throughout the course strongly suggest that the lesion is congenital in origin.

Adult↗
PubMedDate not supplied

Sleep patterns and mortality among elderly patients in a geriatric hospital.

BACKGROUND: Sleep disturbance is one of the major and unsolved problems in older people. Most of the previous sleep studies rely on self-reported documents, and memory disturbance in older people might bias sleep complaints and health status. OBJECTIVE: Sleep disturbances were studied as a mortality risk. METHODS: In 272 patients who were aged, infirmed and chronically institutionalized in a skilled-care geriatric hospital, the presence or absence of sleep disturbances were examined by hourly observations of patients over 2 weeks at baseline, and they were prospectively followed up for 2 years to assess mortality. RESULTS: Mortality after 2 years was significantly higher in the nighttime insomnia, daytime sleepiness, and sleep-onset delay groups. Further, adjusted for age, gender and activities of daily living status, the presence of nighttime insomnia and sleep-onset delay remained associated with a higher risk of mortality. CONCLUSION: Sleep disturbance may be one of the symptoms indicating poor health or functional deficits, and be an independent risk factor for survival.

Activities of Daily Living↗
PubMedDate not supplied

Expression of c-fms proto-oncogene product by ovarian cancer cell lines with effects of macrophage colony-stimulating factor on proliferation.

We studied the production of macrophage colony-stimulating factor (M-CSF) and the expression of c-fms mRNA, an M-CSF receptor, in four human ovarian cancer cell lines. All four cell lines expressed c-fms mRNA while three secreted M-CSF into the culture medium. The exogenous administration of M-CSF caused no significant enhancement of cellular proliferation in any cell line. Interestingly, the proliferation of KK cells was not affected by anti-M-CSF antibody. These results, taken together with the fact that ovarian cancer cells simultaneously produce M-CSF and c-fms, suggest that an autocrine mechanism may modulate cellular proliferation.

Adenocarcinoma↗
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Effects of quercetin and/or restraint stress on formation of aberrant crypt foci induced by azoxymethane in rat colons.

The present study examines the effect of dietary quercetin and/or restraint stress on the formation of aberrant crypt foci (ACF) induced by azoxymethane (AOM) in the colon. Female F344 rats were divided into four groups. All animals were given intraperitoneal injections of AOM. The animals were fed a basal diet (group A, C), or a 2% quercetin-supplemented diet (group B, D). The animals were put individually to narrow wire cages for 1 h every day throughout the study to expose them to mild restraint stress (group C, D). At week 5, all the rats were killed and analyzed for ACF in the colon. The number of ACF increased significantly in the animals subjected to stress (p < 0.05). On the other hand, dietary quercetin significantly reduced the number of ACF in both the nonstress (p < 0.001) and stress groups (p < 0.05). These findings suggest that quercetin might have a potential as a chemopreventive drug for colon cancer despite stress.

Animals↗
PubMedDate not supplied

Effects of high-frequency sound on electrochemical potential using the single-barrel method in guinea pigs.

There are only a few studies investigating the effects of ultrasound on hearing. This paper reports on an experimental investigation on the effect of the long-time exposure to a moderate sound pressure level, high-frequency sound of 16 kHz on the guinea pig inner ear using electrophysiological methods. A decrease of the absolute value of negative potential was observed in the endocochlear potential (EP). The effects of high-frequency sound on EP and electrochemical potential could be explained by a change in the K+ permeability of hair cells.

Acoustic Stimulation↗
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Acarbose, an alpha-glucosidase inhibitor, decreases aortic gene expression and serum levels of monocyte chemoattractant protein-1 in fructose-fed rats.

Insulin resistance is one of the determinants of post-prandial hyperglycaemia. Recently, acarbose, an alpha-glucosidase inhibitor that delays the absorption of carbohydrates from the small intestine, has been found to reduce the incidence of cardiovascular disease in patients with impaired glucose tolerance or diabetes. However, the molecular mechanism by which acarbose inhibits cardiovascular events remains unknown. In this study, we examined whether oral administration of acarbose could suppress expression of monocyte chemoattractant protein-1 (MCP-1) in fructose-fed rats, a widely used animal model of insulin resistance. Serum MCP-1 levels were elevated in fructose-fed rats after 4 weeks. Acarbose treatment for 4 weeks reduced the fructose-induced elevation of serum MCP-1 levels. Acarbose treatment for 8 weeks decreased MCP-1 mRNA levels in the aortae of fructose-fed rats. These results suggest that the cardioprotective effects of acarbose could be due, at least in part, to the suppression of MCP-1 expression.

Acarbose↗
PubMedDate not supplied

Isolation and identification of peptidic alpha-glucosidase inhibitors derived from sardine muscle hydrolyzate.

We report here the isolation of alpha-glucosidase (AGH) inhibitory peptides derived from sardine muscle hydrolyzate, which was prepared by digestion with Bacillus licheniformis alkaline protease. As a result of reversed-phase HPLC purification, two AGH inhibitory peptides were isolated from a DEAE-Sephadex A-25 column eluate. The peptides were identified as follows: Val-Trp (IC50 = 22.6 mM) and Try-Tyr-Pro-Leu (IC50 = 3.7 mM). AGH inhibitory studies of Try-Tyr-Pro-Leu and its derivatives demonstrated the importance of the tri-peptide chain length as well as the hydrophobic aromatic amino acid tyrosine at the N-terminus, aliphatic amino acids at the C-terminus, as well as an amide proton from the peptide chain at the middle position of the tri-peptide to develop AGH inhibition activity.

Animals↗
PubMedDate not supplied

Ultrastructural and fluorescence histochemical studies on the sympathetic innervation of the canine laryngeal glands.

The existence of the adrenergic terminals of the canine laryngeal glands has been revealed by electron microscopy and fluorescence histochemistry. Adrenergic fibres with fluorescent varicosities were observed around the base of th acini in the submucosa. In dogs treated with 5-OHDA, varicosities containing both small and large, dense-cored vesicles containing both small and large, dense-cored vesicles, believed to be adrenergic terminals, were found near blood vessels, gland cells and myoepithelial cells in the submucosal gland region. The role of these adrenergic terminals is briefly discussed.

Adrenergic Fibers↗
PubMedDate not supplied

The development of a high impedance all ceramic thermistor resistant to microwave irradiation: its possible medical application.

We developed a prototype all ceramic thermistor (ACT) composed of a silicon carbide (SiC) ceramic thermistor and SiC ceramic fibre-lead wires in order to accurately measure tissue temperature during microwave heating treatment. High density SiC ceramics reflects electromagnetic waves and manifests microwave resistant properties. The resistance of the SiC ceramic thermistor is approximately 15 M Ohm at 20 degrees C and has a sensitivity of approximately 200 K Ohm/ degrees C. SiC ceramic fibre resistance is approximately 40 K Ohm/cm, whereas its sensitivity is approximately 10 Ohm/ degrees C-cm, significantly lower than that of the SiC ceramic thermistor. The resistance of the SiC ceramic fibre is stable. This enables the ACT to be designed with the two-probe method instead of the four-probe method which was adopted in the Bowman type thermistor, resulting in a greatly simplified model. The measurement error caused by the temperature dependence of SiC ceramic fibre is < 0.02 degrees C. The ACT was inserted into muscle-equivalent agar phantom and into gluteal muscles of rabbits, and microwave irradiation was carried out. We recorded the phantom and tissue temperature without disturbance by the electromagnetic field for heating. This prototype ACT appears promising for its possible clinical applications in such settings as hyperthermic cancer therapy in man.

Agar↗
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Differentiation-inducing effect of thymidine on human neuroblastoma cells.

Human neuroblastoma cells (KP-N-RT(BMI) treated with thymidine underwent morphological differentiation, as revealed by the extension of neurites. The morphological differentiation was caused by deoxyadenosine as well, but not by thymine or deoxyribose. The neurite-extending effect of thymidine was counteracted by deoxycytidine, indicating that inhibition of ribonucleotide reductase was involved. Similar morphological change was indeed brought about by hydroxyurea, a specific inhibitor of the enzyme. Azidothymidine and dideoxythymidine were also effective in induction of neurite extension, suggesting that inhibition of DNA replication, rather than the reductase per se, is responsible for the induction of neurite extension. Supporting this notion, various inhibitors of DNA synthesis induced the morphological differentiation of the cells. Although a-amanitin and cycloheximide were suppressive, actinomycin D promoted the thymidine-induced neurite extension. Morphological changes caused by thymidine were similar to those induced by cyclic AMP, rather than retinoic acid. Intracellular cAMP content was however not increased by the thymidine treatment.

Cell Differentiation↗
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Children's cognition and aircraft noise exposure at home--the West London Schools Study.

The association of aircraft noise exposure with cognitive performance was examined by means of a cross-sectional field survey. Two hundred thirty six children attending 10 primary schools around Heathrow Airport in west London were tested on reading comprehension, immediate/delayed recall and sustained attention. In order to obtain the information about their background, a questionnaire was delivered to the parents and 163 answers were collected. Logistic regression models were used to assess performance on the cognitive tests in relation to aircraft noise exposure at home and possible individual and school level confounding factors. A significant dose-response relationship was found between aircraft noise exposure at home and performance on memory tests of immediate/delayed recall. However there was no strong association with the other cognitive outcomes. These results suggest that aircraft noise exposure at home may affect children's memory.

Aircraft↗
PubMedDate not supplied

Novel airway stent using a thermal shape-memory Ti-Ni alloy.

An attempt was made to develop a tracheal or bronchial stent for nonsurgical implantation using a bronchoscope. Titanium-nickel alloy composed of 50% by weight of each metal has unique thermal shape-memory properties, with a transition temperature of 20 degrees C. Each stent consists of one wire with a diameter of 0.9 mm. It is 30 mm long with a cross-sectional profile resembling a horseshoe. The stent is designed to sustain the airway only at the cartilage rings. Tracheal cartilages of dogs were broken to make a tracheomalasia model, and 10 stents were implanted in 10 animals. The stents were made straight by cooling in liquid nitrogen and then inserted into the region of tracheomalasia. Once in place, they were warmed and recovered their initial shape. The animals were killed between 1 week and 6 months after implantation, and then examined. Nine of the ten stents were located in the implanted area. In one dog, the stent had been displaced into the bifurcation. Microscopic observation showed that the wires were gradually covered with epithelium. At 6 months, 58% were covered with epithelium.

Airway Obstruction↗