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Biomedical subjects

T Sugai

Publications and source records attributed to T Sugai.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Acute renal failure following surgical insult].

It has been claimed that acute renal failure (ARF) following surgical insult was mainly due to the reduction in renal blood flow, especially in renal cortical blood flow. Recent studies, however, pointed out that the majority of the surgical ARF developed due to prolonged SIRS (systemic inflammatory response syndrome) and that those patients developed ARF as a part of multiple organ failure (MOF) complicating other organ failures such as acute respiratory failure. It has been also pointed out that variety of humoral mediators including pro-inflammatory cytokines play a major role in the development of ARF following SIRS. Therefore, the management of such ARF should include some countermeasures against humoral mediators. Various blood purifications have been applied in the management of the patients with ARF. Recently continuous blood purifications got their popularity in the management of the critically ill. Continuous hemodiafiltration (CHDF) has been reported to be applied without any hazardous side effect on the most critically ill patients. CHDF can not only support failing renal function but also can effectively remove causative humoral mediators from the blood stream of the patients. Therefore the CHDF is the first choice blood purification in the management of the ARF patients following surgical insults.

Acute Disease↗
PubMed1996

[Prevention and treatment of postoperative septic MOF and DIC and efficacy of blood purification].

Pathophysiologic concept of SIRS has been proposed for the better management of postoperative severe infection and septic MOF, and the concept has been found to be very useful. It is very important to identify the high risk SIRS patients of the development of septic MOF and to treat those patients aggressively to prevent the development of septic MOF. In the prevention and treatment of septic MOF, the blood purification has been found to be very effective. Among the blood purifications, continuous blood purification, such as continuous hemodiafiltration (CHDF) should be chosen for this purpose. CHDF has been claimed to be very effective to removal of causative humoral mediators from the blood stream. The concept of DIC has been changed recently and the concept of DII (disseminated intravascular inflammation) should be applied instead of DIC, since the main feature of this pathologic condition is the damage of endothelial cells due to extensive systemic inflammation.

Disseminated Intravascular Coagulation↗
PubMed1995

Damped oscillatory activity in the guinea pig accessory olfactory bulb slice.

Extracellular field potentials were recorded from guinea pig accessory olfactory bulb (AOB) slices following electrical stimulation of the vomeronasal nerve layer (VNL). A single shock of the VNL provoked a characteristic damped oscillatory field potential, which consisted of a compound action potential followed by 6-7 periodic negative peaks (n1, n2, n3, n4, n5, n6 or n7). The average frequency of the oscillation was 32 Hz. The existence of oscillation in the AOB suggests the possibility that the oscillatory activity not only may reflect 'quantal' sampling periods, but also may be dynamically altering the AOB conditions under which incoming pheromone-like information is processed.

Action Potentials↗
PubMed1995

Muscular sarcoidosis.

A 57-year-old woman with sarcoid nodules in muscles of the lower leg was reported. A star-shaped low signal intensity in the lesion on MR imaging, supposedly corresponding to fibrous scar, appears characteristic of this condition, although its specificity is still uncertain.

Female↗
PubMed1995

Growth activity in hyperplastic and neoplastic human thyroid determined by an immunohistochemical staining procedure using monoclonal antibody MIB-1.

To increase our understanding of the basic biological mechanisms of thyroid diseases, growth activity (GA) in 232 thyroid lesions was determined by immunohistochemistry using monoclonal antibody MIB-1. The GA tended to be higher in hyperplastic lesions, adenomatous goiter (MIB-1-positive cell rate, 0.73%), and Graves' disease (1.68%) than in normal tissue (0.19%). The GA for differentiated thyroid carcinomas (2.00%) was much lower than for adenocarcinomas of other organs, such as breast, lung, stomach and colon (44.67%). Of the thyroid carcinomas, the highest GA was observed in undifferentiated carcinomas (32.67%), and follicular carcinomas (3.18%) showed a higher GA than papillary carcinomas (1.83%). There was no significant difference between the GA of follicular carcinomas and solid/trabecular adenomas, although widely invasive follicular carcinomas showed a higher GA than minimally invasive carcinomas. No significant correlations between GA and patient age, sex, and tumor diameter, metastasis, or histological features were observed in papillary carcinomas. Familial medullary carcinomas showed a higher GA than sporadic tumors. All latent papillary carcinomas had a very low GA. Our findings suggest that immunohistochemical investigation using the antibody MIB-1 contributes to the understanding of growth characteristics and biological activities in thyroid diseases.

Adenoma↗
PubMed1995

CMP-KDO synthetase: overproduction and application to the synthesis of CMP-KDO and analogs.

CTP:CMP-3-deoxy-manno-octulosonate cytidylyltransferase (CMP-KDO synthetase, EC 2.7.7.38) has been cloned and overexpressed in Escherichia coli. The structure gene was amplified from the total DNA of E. coli K-235 through the primer-directed polymerase chain reaction. The gene was then cloned into lambda ZAP vector at the EcoRI and XbaI restriction sites and overexpressed in E. coli Sure strain at a level approximately 400 times as much as that produced in the host strain. Application of the enzyme to the synthesis of cytidine 5'-monophospho-3-deoxy-D-manno-2-octulosonic acid (CMP-KDO) and analogs was studied. Of several KDO analogs tested, 5-fluoro-2-keto-3,5-dideoxyoctulosonic acid (5-FKDO) was found to be a good substrate of the enzyme, and the product (CMP-5-FKDO) was prepared and characterized, representing the first stable CMP-KDO analog prepared enzymatically to date. The natural enzyme product, CMP-KDO, was however quite unstable (t1/2 = 19 min, in 50 mM MgCl2, 0.2 M Tris buffer, pH 9.0). A mechanism for the decomposition of CMP-KDO involving the hydrogen bonding interactions between the OH groups of C-5 and C-7 (and/or C-8) and the phosphate oxygens was proposed.

Base Sequence↗
PubMed1995

A new strategy for the cloning, overexpression and one step purification of three DHAP-dependent aldolases: rhamnulose-1-phosphate aldolase, fuculose-1-phosphate aldolase and tagatose-1,6-diphosphate aldolase.

Three DHAP-dependent aldolases, rhamnulose-1-phosphate aldolase (Rham-1PA), fuculose-1-phosphate aldolase (Fuc-1PA) and tagatose-1,6-diphosphate aldolase (TDPA) have been cloned and overexpressed in Escherichia coli using two different expression vectors: pTrcHis for the expression of Rham-1PA and Fuc-1PA and pRSET for the expression of TDPA. In each case the recombinant enzyme is synthesized as a fusion protein with a hexahistidine tag on the N-terminus. The three enzymes have been purified in only one step by chelation affinity chromatography. The effects of cultivation temperature and concentration of inducer have been studied in order to optimize the expression of the recombinant proteins and to avoid the formation of inclusion bodies.

Aldehyde-Lyases↗
PubMed1995

Auricular prostheses and osseointegrated implants: UCLA experience.

A clinical study of 40 craniofacial implants placed in 13 auricular defects was conducted over a 6-year period. Implant-retained prostheses were fabricated, the implant success rate was determined, and the soft tissue responses were recorded at regular intervals. All of the implants became osseointegrated and none demonstrated failure during the study period. A five-point scale was used to record the health of the peri-implant soft tissues and the patients were followed up for up to 69 months. The results were as follows: 55.1% of the visit/sites demonstrated an absence of inflammation; 32.3% of the visit/sites demonstrated slight redness; 4.7% demonstrated red and moist peri-implant tissues; 5.5% demonstrated granulation tissue associated with the implants; and in 2.4% of the implants, infection of the peri-implant soft tissues was noted. Good patient hygiene compliance combined with thin and immobile peri-implant soft tissues resulted in minimal soft tissue complications.

Adolescent↗
PubMed1995

The vegetative micronucleus has a critical role in maintenance of cortical structure in Tetrahymena thermophila.

The vegetative role of the germinal micronucleus of Tetrahymena thermophila was studied. Amicronucleate cells that had spontaneously arisen in star strains (very aged cones with defective micronuclei) were observed in B* as well as in A* and in C* and were found to lack the oral apparatus and to have disordered ciliary rows. To reduce uncertainty given the very small micronucleus and possible effects of aging factors, we induced amicronucleate cells in a young clone by treatment with the antitubulin drug, nocodazole, and observed their cortical structure and nuclei. Amicronucleate cells gradually lost their oral apparatus and then their ciliary rows became disordered, even without cell division, and they became crinkled cells. It can be concluded that the vegetative micronucleus appears to play a critical role in the maintenance of the cortical structure, especially of the oral apparatus.

Animals↗
PubMed1995

Intratumoral regional heterogeneity of DNA ploidy patterns in colorectal carcinomas.

There is no agreement on the evaluation of intratumoral DNA ploidy heterogeneity, and its clinical significance remains controversial. We categorized intratumoral ploidy heterogeneity in an effort to avoid confusion and misunderstanding among investigators. We classified the heterogeneity into 3 major types (Types A, B and C) and a combined type (Type D), based on the intratumoral distribution profiles of DNA aneuploid lines identified by flow cytometry in 52 cases of colorectal cancer with intratumoral DNA ploidy heterogeneity selected from a consecutive series. Every carcinoma examined in this study fell into one of the 4 categories: Twenty-six tumors (50%) were classified as Type A, 6 (11%) as Type B, 2 (3%) as Type C, and 18 (36%) as Type D. We discussed the mechanisms of DNA ploidy heterogeneity evolution within a tumor, and also proposed a pathway to these types of DNA ploidy heterogeneity as an aid to understanding the relationship between tumor progression and DNA ploidy changes.

Carcinoma↗
PubMed1994

The role of inositol trisphosphate on ACh-induced outward currents in bullfrog saccular hair cells.

Acetylcholine (ACh) is considered as the most likely candidate for a neurotransmitter of the efferent synapse onto hair cell. In this paper, the nature of this cholinergic receptor mechanism on dissociated bullfrog saccular hair cell was examined by using whole cell recording and Ca2+ sensitive fluorophotometric technique. Both the ACh-induced current and the increase of [Ca2+]i were observed in an oscillatory manner, and were the largest around the basal part of the cell where the efferent synapse is thought to make a contact with the membrane. The reversal potential of ACh-induced current indicated that ACh activated a K+ conductance. The ACh-induced current was reversibly blocked by atropine, d-tubocurarine (dTC), apamin, tetraethylammonium (TEA) and quinine. Neither muscarine nor nicotine mimicked the ACh-induced current. When GTP gamma S was injected into a hair cell, the first ACh application induced an outward current of transient kinetics, but in subsequent trials ACh-induced current lost its decay phase. Intracellularly injected D-myo-inositol 1,4,5-trisphosphate (InsP3) generated outward currents. Intracellularly injected heparin suppressed ACh-induced currents, and lithium (Li+) increased ACh-induced currents. These results indicate that ACh activates a receptor coupled with a guanine nucleotide binding protein (G-protein) which triggers metabolic cascades of InsP3 and Ca2+ leading to the activation of the Ca(2+)-activated K+ channel.

Acetylcholine↗
PubMed1994

Signal propagation from piriform cortex to the endopiriform nucleus in vitro revealed by optical imaging.

Optical signals were recorded from the posterior piriform cortex slices of guinea pigs stained with a voltage-sensitive dye to analyse spatio-temporal spread of neural activity evoked by electrical stimulation of afferent fibers. After propagation of activity along layers II and III, an isolated island of activity appeared deep to the layer III and moved caudally. Histological inspection revealed that the area where the island appeared corresponded well to the endopiriform nucleus. The present results provided an evidence for one of the main outflows of olfactory information from the posterior piriform cortex.

Animals↗
PubMed1994

Optical imaging of the in vitro guinea pig piriform cortex activity using a voltage-sensitive dye.

The spatio-temporal patterns of signal processing in guinea pig piriform cortex (PC) slices were analyzed by optical imaging using a voltage-sensitive dye. Slices (400 microns thick) were cut in a plane parallel to the lateral olfactory tract and perpendicular to the cortical surface. In all the anterior PC and the majority of the posterior PC preparations, neural activity elicited by electrical stimulation of layer Ia propagated along the same layer, then it invaded into layers II and III and propagated along them. In addition to the above pattern, invasion of activity into the deeper area than layer III was observed in some posterior PC preparations. Real-time imaging of an active zone evoked by Ia shocks and its spatio-temporal behavior will contribute to resolving olfactory information processing.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed1994

[Effect of mesalazine microgranules on experimental colitis].

Mesalazine microgranules are an ethylcellulose-coated formulation from which mesalazine is released throughout the intestinal tract and are expected to be effective for idiopathic inflammatory bowel disease, ulcerative colitis and Crohn's disease. Mesalazine microgranules were administered orally to investigate the distribution of mesalazine throughout the intestinal tract in rats. Mesalazine microgranules distributed sufficient amounts of mesalazine and its metabolite, N-acetyl-mesalazine, to the intestinal tissues, while pure mesalazine delivered lower amounts of both. In acetic acid-induced colitis in rats, mesalazine microgranules administered orally reduced the damage score significantly (P < 0.05) at a dose of 50 mg/kg as assessed by macroscopic observation and at 100 mg/kg as assessed by histological evaluation. The number of ulcers in carrageenan-induced colitis in guinea pigs was inhibited at doses of 50, 100, 200 mg/kg, p.o. The colonic wet weight of rats in 2,4,6-trinitrobenzenesulfonic acid (TNB)-induced colitis was reduced significantly (P < 0.05) at a dose of 50 mg/kg, p.o. Mesalazine microgranules showed the ability to distribute mesalazine efficiently throughout the intestinal tract and showed effectiveness against acetic acid-, carrageenan- and TNB-induced colitis. These studies strongly suggest that mesalazine microgranules are effective for idiopathic inflammatory bowel disease.

Aminosalicylic Acids↗
PubMed1994

[Effect of mesalazine, an agent for the treatment of idiopathic inflammatory bowel disease, on reactive oxygen metabolites and LTB4 formation].

Mesalazine microgranules (Pentasa) were developed as a drug for idiopathic inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. In this study, we examined the effect of mesalazine on radical scavenging, lipid peroxidation and the formation of LTB4. Mesalazine reduced the free radical 1,1-diphenyl-2-picrylhydrazyl with an IC50 value of 9.5 microM. It scavenged hydrogen peroxide and hypochlorite (IC50: 0.7 microM and 37.0 microM, respectively), but had no effect on superoxide. Lipid peroxidation in rat liver microsomes was inhibited by mesalazine (IC50: 12.6 microM). Mesalazine significantly inhibited (P < 0.01) gastric mucosal lipid peroxidation induced by ischemia and reperfusion in rats at a dose of 50 mg/kg, p.o. Mesalazine also inhibited the formation of LTB4 in rat peritoneal neutrophils (IC50: 44.9 microM). N-Acetyl-mesalazine, the metabolite of mesalazine, had no effect on radical scavenging and lipid peroxidation. Only a high concentration (1 mM) of the metabolite inhibited the formation of LTB4. These studies suggest that mesalazine inhibits cell injury in the inflamed mucosa by scavenging reactive oxygen metabolites and prevents the invasion of neutrophils by inhibition of LTB4 formation.

Aminosalicylic Acids↗
PubMed1994

[Flow cytometric analysis of DNA ploidy in intramucosal gastric carcinoma].

In order to investigate whether or not DNA ploidy was altered in intramucosal gastric carcinomas, nuclear DNA content of biopsy specimen was measured using flow cytometry in 38 intramucosal carcinomas. DNA aneuploidy was detected in 27 of 38 lesions (71.1%), and noted more frequently in differentiated carcinomas than in undifferentiated ones (83.0% vs. 20.0%, p < 0.01). There was no significant relationship between the frequency of DNA aneuploidy and macroscopical type or tumor size. DNA aneuploidy was even found in two of three minute carcinomas (5 mm or less in diameter). DNA indices showed 1.2 or lower values in 40% of the lesions with DNA aneuploidy. The average value of DNA index was significantly larger in depressed type than in elevated type (p < 0.01). In conclusion, DNA ploidy is altered in most differentiated intramucosal carcinomas. A high resolution method is essential for accurate determination of DNA ploidy in intramucosal carcinomas, especially elevated ones.

Adenocarcinoma, Papillary↗