Biomedical subjects

Y Tsuchiya

Publications and source records attributed to Y Tsuchiya.

At least 37 records · Page 2Linked to original sources

PubMed2001

Characterization of a membrane-bound arginine-specific serine protease from rat intestinal mucosa.

Previously we isolated and characterized a membrane-bound, arginine-specific serine protease from pig intestinal mucosa [J. Biol. Chem. 269, 32985-32991 (1994)]. For further characterization of this type of enzyme, we cloned a cDNA from rat intestinal mucosa encoding the precursor of a similar protease. The partial amino acid sequences determined for the pig enzyme were found to be shared almost completely by the rat enzyme. The serine protease domain of the rat enzyme, heterologously expressed in Escherichia coli, specifically cleaved Arg (or Lys)-X bonds with a marked preference for Arg-Arg or Arg-Lys, similar to the pig enzyme. The mRNA for the rat enzyme was shown to be distributed mainly in intestine, and the enzyme was detected in the duodenal mucosa as a 70 kDa protein. Immunohistochemical analysis of the small intestinal tissue showed that the enzyme is localized mainly on brushborder membranes.

Amino Acid Sequence↗

PubMed2001

Fitness of biocompatible high-flux hemodiafiltration for dialysis-related amyloidosis.

AIMS: In order to assess the long-term influence of high-flux hemodiafiltration (HDF) on hemodynamic stability in patients with dialysis-related amyloidosis. METHODS: HDF with high-flux dialyzers was performed for a year in 11 patients who had undergone the surgery for carpal tunnel syndrome. Patients were divided into two groups, and for each group synthetic or cellulose membrane dialyzers were applied. RESULTS: A year after the exchange from standard hemodialysis to HDF with cellulose high-flux dialyzers, beta(2)-microglobulin was decreased (45+/-3 to 28+/-2 mg/l, n = 5, p< 0.05), but plasma non-refilling ratio was not altered. However, the continuance of synthetic high-flux HDF for a year decreased plasma non-refilling ratio (17+/-5 to 7+/-4%, p<0.05), hypotensive episodes (4.3+/-0.6 to 2.5+/-0.4 sessions/month, p<0.05) and muscle cramps (3.8+/-0.5 to 1.8+/-0.5 sessions/month, p<0.01) in addition to the decrements in serum beta(2)-microglobulin (45+/-5 to 33+/-2 mg/l, n = 6, p<0.01). CONCLUSIONS: Although the study on a large number of patients may be required to draw a final conclusion, our present data suggest that biocompatible high-flux HDF is uniquely suited for dialysis-related amyloidosis.

Aged↗

PubMed2001

A giant left ventricular thrombus in a patient with acute myocardial infarction--a case report.

The authors report a patient with acute anteroseptal myocardial infarction with a giant left ventricular thrombus at the apex. The patient also had nephrotic syndrome due to diabetic nephropathy. Coronary angiography showed 90% stenosis at segment 6 of the left anterior descending coronary artery. Percutaneous transluminal coronary angioplasty and intracoronary stenting were performed on the 30th day, and effective coronary blood flow was obtained. Heparin was injected intravenously for the first 7 days, and warfarin was administered thereafter. The left ventricular thrombus disappeared after 46 days. No evidence of arterial thromboembolism was found during the disappearance of the left ventricular thrombus as determined by echocardiography.

Angioplasty, Balloon, Coronary↗

PubMed2001

Relationship between effects of phenolic compounds on the generation of free radicals from lactoperoxidase-catalyzed oxidation of NAD(P)H or GSH and their DPPH scavenging ability.

The influence of various phenolic compounds on the lactoperoxidase (LPO)/hydrogen peroxide (H2O2)-catalyzed oxidation of biochemical reductants such as reduced beta-nicotinamide adenine dinucleotide (NADH), reduced beta-nicotinamide adenine dinucleotide phosphate (NADPH) or reduced glutathione (GSH) was investigated by electron spin resonance (ESR) spectroscopy. Micromolar quantities of phenolic compounds such as 17beta-estradiol, phenol, and p-chlorophenol enhanced the LPO/H2O2-catalyzed oxidation of NAD(P)H or GSH to generate a large amount of superoxide radical (O2*-) or glutathione thiyl radical (GS*), while, phenolic compounds such as quercetin and Trolox C greatly suppressed the generation of O2*- and GS*. In order to elucidate the effects of phenolic compounds on the generation of O2*- and GS*, their quenching activities for a stable radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), were investigated by ESR spectroscopy. 17beta-Estradiol, phenol, and p-chlorophenol showed very weak scavenging activities for DPPH, but quercetin and Trolox C showed strong activities. This suggests that the ability of phenolic compounds to enhance LPO/H2O2-catalyzed oxidation of NAD(P)H or GSH relates inversely to their ability to quench DPPH. That is, phenolic compounds having weak quenching activity against DPPH may enhance the LPO/H2O2-catalyzed oxidation of NAD(P)H or GSH to generate a large amount of O2*- or GS*.

Bepridil↗

PubMed2001

A clinical evaluation of lymphangioma of the large intestine: a case presentation of lymphangioma of the descending colon and a review of 279 Japanese cases.

With the development and widespread use of colonoscopy, lymphangioma of the large intestine has recently been reported frequently. This paper presents some findings from a review of 279 cases of this disease in Japan, including a typical case that we encountered. A 69-year-old female was diagnosed as having lymphangioma of the descending colon based on the findings of a barium enema and a colonoscopy, and the lesion was successfully removed by an endoscopic resection. In the published reports, the etiology of this disease is not clear yet but the age at onset range shows a tendency toward a higher incidence in comparatively older patients and the male-to-female ratio indicates a higher incidence in males. If there is no complication, endoscopic treatment seems to be the preferable procedure for this disease.

Aged↗

PubMed2001

Certain styrene oligomers have proliferative activity on MCF-7 human breast tumor cells and binding affinity for human estrogen receptor.

To examine the estrogenic activities of styrene oligomers, we carried out cell proliferation assays with estrogen-sensitive MCF-7 cells and competitive binding assays to human estrogen receptor [alpha] (hER[alpha]). The styrene oligomers tested were 1,3-diphenyl propane (SD-1), 2,4-diphenyl-1-butene (SD-2), cis-1,2-diphenyl cyclobutane (SD-3), trans-1,2-diphenyl cyclobutane (SD-4), 2,4,6-triphenyl-1-hexene (ST-1), 1a-phenyl-4a-(1'-phenylethyl)tetralin (ST-2), 1a-phenyl-4e-(1'-phenylethyl)tetralin (ST-3), 1e-phenyl-4a-(1'-phenylethyl)tetralin (ST-4), 1e-phenyl-4e-(1'-phenylethyl)tetralin (ST-5), 1e,3e,5a-triphenylcyclohexane (ST-6), and 1e,3e,5e-triphenylcyclohexane (ST-7). In the MCF-7 cell proliferation assay, styrene trimers (ST-1, ST-3, ST-4, and ST-5) had the highest proliferative activities of the compounds tested. The relative potency of these chemicals was 0.0002-0.0015%, which was comparable with that of bisphenol A (0.0001-0.0025%), and their relative proliferative effect was 51-104%. Styrene dimers (SD-3 and SD-4) also significantly increased the cell yields. However, SD-1, SD-2, ST-2, ST-6, and ST-7 had insignificant proliferative activities. The competitive binding assay revealed the binding affinity of some styrene oligomers for hER[alpha]. The order of their binding potency for hER[alpha] was as follows: ST-4 > ST-2 > ST-3 > ST-5 > ST-1 > SD-3 > SD-4 > SD-2 > SD-1. ST-6 and ST-7 did not appear to bind to hER[alpha]. The present studies indicate that styrene dimers SD-3 and SD-4 and styrene trimers ST-1, ST-3, ST-4, and ST-5 have estrogenic activity on MCF-7 cells and binding affinity for hER[alpha]. These compounds might be endocrine disrupters.

Binding, Competitive↗

PubMed2001

Na+-dependent recovery of intracellular pH from acid loading in mouse colonic crypt cells.

The membrane transport mechanism for regulating the intracellular pH value (pHi) was investigated in mouse distal colon crypt cells. pHi was measured by microfluorometry in an isolated crypt fragment loaded with the pH-sensitive fluoroprobe, 2',7'-bis-(2-carboxyethyl)-5-(6) carboxyfluorescein. The pHi recovery process after acid loading induced by a 40 mM NH4Cl prepulse was almost totally dependent on Na+ in both the presence and absence of CO2/HCO3- in the perfusion solution. In the CO2/HCO3(-)-free, HEPES-buffered solution, amiloride partially inhibited the pHi recovery rate from acid loading with an ED50 value of 15 microM and maximum inhibition of 83%. In a CO2/HCO3- solution, amiloride inhibited the pHi recovery rate with an ED50 value of 18 microM, which was similar to that in the HEPES-buffered solution, while the rate of pHi recovery remaining in the presence of the maximum effective concentration of amiloride was significantly larger than that in the HEPES-buffered solution. The Na+-dependent pHi recovery from the acid loading was significantly less (by 18%) in the presence of forskolin. These results suggest that the pHi recovery from acid loading was mediated by 1) amiloride-sensitive Na+/H+ exchanger, 2) the amiloride-insensitive Na+/H+ exchanger, and 3) the Na+- and HCO3(-)-dependent acid extruder. The pHi recovery could be inhibited by cAMP.

Amiloride↗

PubMed2001

The effect of cAMP on electrogenic Na(+) absorption in the rat distal colon.

Cyclic AMP is a ubiquitous second messenger produced in cells in response to extracellular stimulants. The aim of this study was to examine its role in the regulation of amiloride-sensitive electrogenic Na(+) absorption in the rat distal colon by measuring the short-circuit current (I(sc)) and (22)Na(+) fluxes in a chamber-mounted mucosal sheet. Forskolin stimulated the amiloride-inhibitable I(sc) and amiloride-inhibitable (22)Na(+) absorption. 8Br-cAMP also stimulated the amiloride-inhibitable I(sc). Furthermore, isoproterenol, acting via beta-adrenergic activation, stimulated the amiloride-inhibitable I(sc). The isoproterenol-induced increase in the amiloride-sensitive I(sc) was largely suppressed by H89, a protein kinase A inhibitor. In conclusion, cAMP can upregulate amiloride-sensitive electrogenic Na(+) absorption in the rat distal colon.

Absorption↗

PubMed2000

The roles of platelet-activating factor and endothelin-1 in renal damage after total hepatic ischemia and reperfusion.

BACKGROUND: This study was designed to verify the involvement of platelet-activating factor (PAF) in renal damage associated with hepatic ischemia and reperfusion (HIR) injury through the release of endothelin (ET)-1 and to determine the modulating effect of a specific PAF receptor antagonist on these insults in rats. METHODS: Male rats pretreated with either normal saline as a vehicle (NS group) or intravenous TCV-309, a PAF receptor antagonist (TCV group), were subjected to 120 min of total hepatic ischemia under an extracorporeal portosystemic shunt. Plasma aspartate transaminase, creatinine, blood urea nitrogen, and ET-1 levels and the relative renal wet weight were determined under nonischemic conditions and at 1, 3, and 6 hr of reperfusion after hepatic ischemia. Changes in mean arterial blood pressure and renal tissue blood flow measurements in the kidney were determined throughout the experiment. RESULTS: Increased plasma aspartate transaminase, creatinine, blood urea nitrogen, and ET-1 levels and the relative renal wet weight after HIR in the NS group were significantly suppressed by TCV-309 pretreatment. Mean arterial blood pressure and renal tissue blood flow after HIR in the TCV group were significantly improved when compared with those in the NS group. These effects resulted in attenuation of structural hepatic and renal damage with the improvement of 7-day survival (62%). CONCLUSIONS: The present study demonstrates that renal damage as well as critical liver injury is produced after reperfusion following 120 min of total hepatic ischemia. A PAF receptor antagonist may be therapeutically useful to protect against these types of damage via indirect modulation of plasma ET-1 levels.

Animals↗

PubMed2000

Role of the vestibular system in sudden shutdown of renal sympathetic nerve activity during microgravity in rats.

The purpose of this study was to examine the effect of microgravity (muG) on renal sympathetic nerve activity (RNA) in rats. Additionally, we estimated the participation of the vestibular system in the response of RNA to muG. Eight normal Sprague-Dawley (SD) rats and five chemically and bilaterally labyrinthectomied SD rats were used to measure RNA during free-drop examination (4.5-s duration of muG); arterial pressure (AP) and aortic flow velocity (AFV) were additionally monitored. Although AFV showed no particular change, AP tended to decrease during muG in the later phase. Prior to this AP fall-off, RNA was immediately and markedly attenuated by muG. This attenuation was transient and RNA returned to 1G level within the mu;muG condition. Interestingly, this phenomenon remained even in labyrinthectomied rats. In conclusion, cephalad shift of the body fluid by loading of muG may cause cardiopulmonary low-pressure receptor activation and consequent RNA attenuation, but the participation of the vestibulosympathetic reflex in this phenomenon is not obvious.

Animals↗

PubMed2000

The role of ABI3 and FUS3 loci in Arabidopsis thaliana on phase transition from late embryo development to germination.

Arabidopsis abi3 and fus3 mutants are defective in late embryo development and their embryos show precocious growth. To understand the function and role of ABI3 and FUS3, we analyzed expression patterns of genes which were normally activated during late embryo development and germination in these mutants. Using the differential display method, both upregulated and downregulated genes were observed in immature siliques of the abi3 fus3 double mutant. Four clones having more abundant expression in the abi3 fus3 double mutant than in wild type were isolated. These genes were activated during wild-type germination, suggesting that some genes that are activated during wild-type germination are precociously activated in the abi3 fus3 mutant during late embryo development. Also, genes that were activated during wild-type germination were isolated and their expression patterns during late embryo development in the wild type and in abi3, fus3, and abi3 fus3 mutants were analyzed. Sixteen such clones were found, and 11 of these showed derepression or precocious activation of gene expression in the mutants. These results indicate that ABI3 and FUS3 negatively regulate a particular set of genes during late embryo development. We also showed that immature fus3 siliques accumulated one-third of the wild-type level of abscisic acid (ABA), but mature fus3 siliques accumulated ABA at a level comparable to that in the wild type. The possible mechanisms of controlling developmental timing in late embryo development as well as collaborative and distinct roles of ABI3 and FUS3 are discussed.

Arabidopsis↗

PubMed2000

Marginal ulceration after pylorus-preserving pancreaticoduodenectomy.

Marginal ulceration is a serious problem after both standard pancreaticoduodenectomy (PD) and pylorus-preserving pancreaticoduodenectomy (PPPD). The relationship between this complication and the method of reconstruction after PPPD was analyzed in this study. Patients who underwent standard PD (n = 72) or PPPD (n = 28) in the 20-year period from 1978 to 1997 were retrospectively reviewed. After PPPD, 4 patients (14.3%) developed marginal ulceration on the jejunal side of the duodenojejunal anastomosis, while none of the patients had marginal ulceration after standard PD. The marginal ulcer occurred in 3 of 14 patients treated with the Roux-en-Y method, and in 1 of 9 treated with pancreatogastrostomy. In the Roux-en-Y method, the anal jejunal loop anastomosed to the bulb was directly exposed to gastric juice without neutralization by pancreatic juice from the oral jejunal limb. Of the 4 patients with marginal ulceration, 2 of those treated by the Roux-en-Y method required gastrectomy; the other 2 patients were treated medically. Our analysis of the literature showed that the Roux-en-Y method had the highest incidence of marginal ulcerations. The gastrointestinal reconstruction method without a mixture of gastric juice and pancreatic juice may be a causal factor in the marginal ulceration that occurs after PPPD. In reconstruction after PPPD, we should not create a jejunal loop that is exposed to gastric juice alone.

Aged↗

PubMed2000

Portal vein thrombosis caused by microwave coagulation therapy for hepatocellular carcinoma: report of a case.

Microwave coagulation therapy (MCT) is one of the treatment modalities for patients with hepatocellular carcinoma (HCC). A 67-year-old man with liver cirrhosis underwent MCT during a laparotomy for a deeply located HCC (2.5 cm in diameter) at the border of the anterior and posterior segments of the right hepatic lobe. Two weeks after MCT, he complained of abdominal fullness. Portal vein thrombosis (PVT) was diagnosed because he had massive ascites and an echogenic mass in the portal vein on abdominal ultrasonography. PVT was successfully treated by fibrinolytic therapy with a selective infusion of urokinase via the superior mesenteric artery (SMA). There have been few reports on PVT as a complication of MCT. Attention should be paid to the possible occurrence of PVT as a critical complication after MCT for liver tumors adjacent to the portal vein. Fibrinolytic therapy via the SMA is thus considered to be an effective approach for PVT after MCT.

Aged↗

PubMed2000

Lymphoepithelial cyst of the pancreas: report of a case.

An extremely rare case of a lymphoepithelial cyst (LEC) of the pancreas is described herein. A pancreatic cystic tumor was initially detected in a 50-year-old man at a medical checkup. On admission, his serum carbohydrate antigen (CA) 19-9 level was 8100 U/ml and a computed tomography scan revealed a well-circumscribed multilocular cystic tumor in the pancreatic head and body. Magnetic resonance cholangiopancreatography showed no communication between the pancreatic ducts and the tumor. A distal pancreatectomy with lymph node dissection was performed because the lesion was suspected to be a mucinous cystadenoma or cystadenocarcinoma of the pancreas. However, histological examination revealed that the cyst was lined by stratified squamous epithelium and surrounded by lymphoid tissue. thereby confirming the diagnosis of LEC of the pancreas. The superficial layer of squamous epithelium and the cystic contents were found to be immunohistologically positive for CA19-9. Establishing a preoperative diagnosis of LEC is quite difficult because it resembles other cystic neoplasms of the pancreas in radiographic features and is frequently associated with an elevation of serum tumor markers such as CA19-9.

Biomarkers, Tumor↗

PubMed2000

Acute responses of renal nerve activity to microgravity induced by free drop in anesthetized rats.

To examine acute cardiovascular and autonomic responses to microgravity (microG), arterial pressure (AP), aortic flow velocity (AFV), central venous pressure (CVP), and renal nerve activity (RNA) were measured in anesthetized rats during 4.5 s of microG produced by free drop. A smooth and immediate reduction in gravity occurred during free drop, microG being achieved 100 ms after the start of the drop. Acute microG elicited an immediate and striking, but transient, decrease in RNA with no significant change in AP and AFV, but a significant decrease in CVP. The decrease in RNA lasted 2 s, then RNA recovered to the control level despite the G value remaining at < 0.001 for 4.5 s. The RNA decrease was attenuated or completely abolished by sinoaortic denervation, vagotomy, or sinoaortic denervation plus vagotomy. These results suggest that acute microG conditions stimulate sinoaortic and cardiopulmonary mechanoreceptors and suppress RNA.

Animals↗

PubMed2000

Discovery of novel trans-3,5-disubstituted pyrrolidinylthio-1beta-methylcarbapenems.

Novel trans-3,5-disubstituted pyrrolidinylthio-1beta-methylcarbapenems were designed and synthesized to provide J-111,347 (1a) as the first example of an exceptionally broad-spectrum antibiotic, showing activity against methicillin-resistant Staphyloccocus aureus (MRSA) as well as Pseudomonas aeruginosa. Further derivation of 1a afforded J-111,225 (2a), J-114,870 (3a), and J-114,871 (3b). which showed improved safety profiles and retained broad-spectrum antibacterial activities.

Animals↗

PubMed2000

Deep venous thrombosis and pulmonary thromboembolism associated with a huge uterine myoma--a case report.

A 51-year-old woman with a large uterine myoma suffered from acute pulmonary thromboembolism. Venography revealed thrombosis in the right common iliac vein and almost complete obstruction of the left common iliac vein. The ascending lumbar vein showed collateral drainage. Treatment was initiated with continuous intravenous heparin sodium, and a Greenfield filter was inserted to prevent the extension of the pulmonary embolism during and after hysterectomy. After a total hysterectomy, venography revealed restoration of patency in the bilateral common iliac veins, and no flow was seen in the ascending lumbar vein. Thorough clinical examinations failed to identify any other prothrombotic conditions. These results suggest that a large uterine myoma compressed veins in the pelvis, and the resulting impaired blood flow caused deep venous thrombosis and pulmonary thromboembolism.

Female↗

PubMed2000

Studies on the 1,1-diphenyl-2-picrylhydrazyl radical scavenging mechanism for a 2-pyrone compound.

The radical scavenging mechanisms for the 2-pyrone compound, 4-hydroxy-3,6-dimethyl-2H-pyrane-2-one (1), and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (4) in several solvent systems were evaluated by the quantitative change in compounds detected at 270 nm and subsequent HPLC analyses. The HPLC profile for each condition suggested that the reaction proceeded by a different mechanism in each solvent system. In organic solvents (CHCl3, iso-propanol, and EtOH), 1-[4-(3,4-dihydro-3,6-dimethyl-2,4-dioxo-2H-pyran-3-yl) phenyl]-1-phenyl-2-picrylhydrazine (2) was produced as an adduct of the DPPH radical and 1. On the other hand, the reaction in a buffer solution (an acetate buffer at pH 5.5) gave several degradation products with 1[4-(2,3-dihydro-2,5-dimethyl-3-oxo-fur-2-yl) phenyl]-1-phenyl-2-picrylhydrazine (5), this being structurally elucidated by spectroscopic analyses. The decrease of the DPPH radical in each reaction system suggests that compound 1 could scavenge about 1.5-1.8 equivalents of the radical in organic solvents and about 3.5-3.9 in the buffer solution.

Bepridil↗