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Biomedical subjects

S Kurosawa

Publications and source records attributed to S Kurosawa.

At least 73 records · Page 4Linked to original sources
PubMed1994

Regulation of PI hydrolysis and cAMP formation by muscarinic M3 receptor in guinea pig gallbladder.

Carbachol (10(-8)-10(-3) M) produced two distinct biochemical responses in the guinea pig gallbladder smooth muscle: simulation of phosphoinositide (PI) hydrolysis and inhibition of forskolin-mediated adenosine 3',5'-cyclic monophosphate (cAMP) formation in a dose-dependent manner. The mean effective dose (ED50) concentration (1.6 x 10(-5) M) of carbachol-mediated stimulation of PI hydrolysis was 145 times greater than the ED50 concentration (1.1 x 10(-7) M) of carbachol mediated inhibition of cAMP formation. The inhibitory effect of carbachol on cAMP formation was antagonized by the pretreatment of pertussis toxin. To determine whether these two biochemical responses were mediated by the same or different subtypes of muscarinic receptors, the relative potencies of muscarinic receptor antagonists were calculated by Schild analysis. The M3 muscarinic antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) exhibited inhibitory constant (Ki) values at 0.3 and 1.2 nM in antagonizing the stimulation of PI hydrolysis and the inhibition of cAMP formation, respectively. The corresponding Ki values for pirenzepine, a muscarinic M1 antagonist, were 11 and 130 nM. The corresponding Ki values for AF-DX 116, a muscarinic M2 antagonist, were 34 and 450 nM. Thus 4-DAMP was 37x and 108x more potent than pirenzepine in antagonizing the stimulation of PI hydrolysis and the inhibition of cAMP formation, respectively. In addition, compared with AF-DX 116, 4-DAMP was 113x and 375x more potent in reducing stimulation of PI hydrolysis and inhibition of cAMP formation. Cholecystokinin (CCK) octapeptide (10(-10)-(10-6) M) caused a significant increase of PI hydrolysis but had no inhibitory effects on cAMP formation evoked by forskolin (10(-5) M).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Examinations to detect left atrial thrombus and blood coagulation test analyses in aged patients with atrial fibrillation].

To screen for risk of embolism, we investigated the association between the presence of left atrial (LA) thrombus by transesophageal echocardiography (TEE) and blood coagulation tests, including thrombin-antithrombin III complex (TAT), plasminogen activator inhibitor 1 (PAI-1), plasmin-alpha 2-plasmin inhibitor complex (PIC), D-dimer, tissue plasminogen activator (tPA), free tPA, tPA.PAI-1 complex, prothrombin fragment 1+2 and fibrin degradation product E (FDP-E) in 40 patients with atrial fibrillation (Af) (13 males, 27 females, mean age 76 +/- 8 yrs). Blood coagulation tests were performed in 21 control subjects with sinus rhythm (12 males, 9 females, mean age 75 +/- 4 yrs). LA thrombi were detected in the appendage of 8 patients and in the atrium of 6 patients. Severe atherosclerotic plaque with thrombi in the thoracic aorta were detected in 6 patients without LA thrombi. FDP-E, D-dimer and PIC increased significantly in patients with LA thrombi or aortic plaque in comparison with controls with sinus rhythm. In patients with Af, 25 of them (group A) has more than 4 abnormal coagulation values out of 9 tests and 15 of them (group B) had abnormalities in less than 3 tests. LA thrombi or aortic plaque were detected in 18 patients in group A and 2 patients in group B (72% vs 13%, p < 0.01). In 4 of 6 patients with large LA thrombi, the thrombi were resolved after administration of warfarin. Before administration of warfarin, tPA, PA-1 and tPA.PA-1 complex levels were higher in the two patients whose thrombi did not resolve.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Thrombotic thrombocytopenic purpura (TTP) with a low level of apolipoprotein A-I (Apo A-I) which responded to combination of vincristine and beraprost].

A 51-year-old man was admitted to the psychiatric ward because of increasing confusion and irrational behavior. He was later transferred to our department due to anemia and thrombocytopenia. A diagnosis of thrombotic thrombocytopenic purpura (TTP) was made based on the presence of thrombocytopenic purpura, microangiopathic hemolytic anemia, neurological symptoms and fever. Corticosteroids, plasma exchange (PE), dextrans, dipyridamole and vincristine (VCR) were given without satisfactory response. Beraprost sodium was prescribed followed by a dramatic improvement and complete remission. A number of reports indicated that prostacyclin metabolism was involved in the pathogenesis of TTP. Recently Apo A-I was identified to be a prostacyclin-stabilizing factor, which was initially low in this patient. If patients do not respond to either PE or VCR, consideration should be given to treatment with beraprost, especially when the level of Apo A-I is low.

Apolipoprotein A-I↗
PubMed1993

Quartz crystal microbalance for the detection of microgram quantities of human serum albumin: relationship between the frequency change and the mass of protein adsorbed.

We have developed a piezoelectric immunosensor for the detection of microalbumin. Human serum albumin (HSA) in the range 0.1-100 micrograms mL-1 could be detected using a flow cell; the immunosensor is sensitive enough to monitor levels of albuminuria. The immunosensor did not respond to bovine serum albumin, only to HSA, implying that the specificity for HSA was high. We investigated the relationship between the frequency change (delta F) and adsorption per unit area of piezoelectrically active quartz crystal (delta M). delta M was estimated with radioisotope-labeled anti-HSA or HSA. When anti-HSA was adsorbed onto the surface of the crystal or HSA was bound to anti-HSA supported by the crystal, values of magnitude of delta F/delta M were larger than the value predicted from theory (Sauerbrey's equation). Furthermore, magnitude of delta F/delta M for HSA was larger than that for anti-HSA.

Adsorption↗
PubMed1993

Autoreactive and heat shock protein 60-recognizing CD4+ T-cells show antitumor activity against syngeneic fibrosarcoma.

A CD4+ heat shock protein (hsp) 60-recognizing autoreactive T-cell line (BASL1) and clone (BASL1.1) were examined for their antitumor activity against major histocompatibility complex class II- syngeneic Meth A fibrosarcoma (Meth A), which was immunofluorescently stained with monoclonal antibody specific for hsp 60. In in vitro proliferative assay, BASL1.1 was suggested to recognize Meth A-derived hsp 60 presented by syngeneic antigen-presenting cells in a major histocompatibility complex class II-restricted manner. This cell line and clone showed antitumor activity in tumor-neutralizing (Winn) assay. BASL1 and BASL1.1 cells produced gamma-interferon, tumor necrosis factor, and interleukin 2 but not interleukin 4 by the stimulation with syngeneic spleen cells. In cytolytic assay, these cell lines and clones showed neither direct nor indirect (bystander) cytolysis against Meth A. In cytostatic assay, these cells inhibited the proliferation of Meth A in the presence of syngeneic macrophages, and this activity was abrogated by the addition of anti-gamma-interferon monoclonal antibody. Recombinant gamma-interferon could induce cytostatic activity only in the presence of macrophages, and tumor necrosis factor synergized this activity. Antitumor activity induced by BASL1 was abrogated by the administration of anti-CD8 monoclonal antibody in vivo, suggesting that CD8+ cytotoxic T-lymphocytes are essential and final effector cells for BASL1-mediated Meth A rejection. These findings indicate that CD4+ autoreactive and hsp 60-recognizing T-cells show two types of antitumor activity: cytostasis and induction of tumor-specific cytotoxic T-lymphocytes. Furthermore, these results imply that tumor-specific immunity could be elicited by CD4+ helper T-cells which recognize hsp.

Animals↗
PubMed1993

Early appearance and activation of natural killer cells in tumor-infiltrating lymphoid cells during tumor development.

We investigated NK cell infiltration into tumor developing lesions at early stage of tumor development after intraperitoneal inoculation of 3LL lung carcinoma into syngeneic C57BL/6 mice. Natural killer (NK) cells, which were detected by anti-NK 1.1 monoclonal antibody (mAb), remarkably increased in number in tumor-developing lesions (peritoneal cavity) as early as day 3 after inoculation of 3LL. The tumor-infiltrating NK cells from 3LL-inoculated mice produced a high level of interferon-gamma by co-culture with 3LL and showed enhanced cytotoxic activities against both NK-sensitive (YAC-1) and NK-resistant (3LL and P815) tumors. Furthermore, mice depleted of NK cells by injection of anti-NK 1.1 mAb or anti-asialo GM1 antibody showed shorter survival times after intraperitoneal inoculation of 3LL when compared with control mice. These results suggest that NK cells infiltrate the tumor-developing lesion at an early stage and may participate in the early protection against tumors through production of a high amount of interferon-gamma and enhanced cytotoxicity at tumor-bearing sites.

Animals↗
PubMed1993

Serum concentration and cardiovascular effects of salbutamol after oral and rectal administration in healthy volunteers.

In order to evaluate rectal administration of salbutamol (SB), five healthy volunteers were dosed orally and rectally with racemic SB (0.1 mg/kg) solution. Compared with the oral SB, the rectal SB gave significantly higher serum SB concentration immediately after dosing but slightly lower levels in the elimination phase. The Cmax following rectal administration was 17.9 ng/ml (17.0 ng/ml for oral administration), the tmax 0.67 h (1.5 h for oral administration) and the AUC 98.2 ng/ml/h (100 ng/ml/h for oral administration). Heart rate also rose more rapidly to a maximum of 70% above baseline values after rectal dosing. The rate continued to be twice larger than after oral dosing for up to 5 h. The concentration versus response curves indicated that rectal SB was more effective than oral SB at increasing heart rate at the same SB concentration in serum. A plausible explanation for this phenomenon might be a difference in the stereo-selective first-pass metabolism of the two enantiomers. Therefore, the rectal dose of SB administered as a suppository for prophylactic treatment of asthma should be lower than that used orally.

Administration, Oral↗
PubMed1993

Transcriptional regulation of Bacillus thuringiensis subsp. israelensis mosquito larvicidal crystal protein gene cryIVA.

The cryIVA gene encodes a component of the delta-endotoxin of Bacillus thuringiensis subsp. israelensis. By S1 nuclease mapping and primer extension analysis, we have identified the transcriptional initiation site of cryIVA. The transcriptional activity from the promoter was detected only for the sporulating cells more than 3 h after onset of the stationary phase. Upstream from the cryIVA transcriptional initiation site was found a nucleotide sequence partially homologous to the promoter consensus sequence for the E sigma E holoenzyme of Bacillus subtilis. Thus, it was strongly suggested that the identified cryIVA promoter, like some other crystal protein gene promoters, was under the control of sigma 35, the B. thuringiensis homolog of sigma E.

Amino Acid Sequence↗
PubMed1993

Hereditary hydronephrosis in C57L/MsNrs mice.

Inbred C57L/MsNrs mice (66 males and 72 females) maintained at the National Institute of Health, Japan, were examined grossly for hydronephrosis. Unlike the hydronephrotic strains of mice reported so far, C57L mice showed no sex-related difference in the incidence (62% in males and 75% in females; P > 0.05) and severity of hydronephrosis. The right kidney was more severely affected than the left kidney in both sexes. Age appeared to have no influence on the incidence.

Animals↗
PubMed1993

[Ischemic bowel disease].

Arteries of the small intestine and colon have several anastomotic interconnections that help protect against the consequence of occlusive vascular disease. Vascular ischemic syndromes of the colon include several clinical entities, depending upon the degree and duration of the interruption of vascular flow. They include acute mesenteric artery occlusion, abdominal angina and ischemic colitis. Acute mesenteric artery occlusion is usually caused by an embolus from the heart and if the diagnosis is delayed, the mortality is quite high. Abdominal angina often precedes the acute mesenteric artery occlusion. On the other hand, ischemic colitis consists of the solitary disease entity because of its characteristic clinical and radiographic features. Recently, many cases of ischemic colitis have been reported. This article reviews the recent advances in ischemic bowel disease.

Arteriosclerosis↗
PubMed1993

Molecular diversification of dominant subclones in vivo and in vitro in Ph-positive ALL.

A leukemia line KOPN30bi was established from a patient with acute lymphocytic leukemia (ALL) and Philadelphia (Ph) chromosome. The clonal rearrangement of the immunoglobulin heavy chain (IgH) gene and the expression of the P190 type BCR/ABL chimeric transcript were shown to be identical between KOPN30bi and the predominant clone (S1) in the blast cell population from which KOPN30bi was established, indicating that they are of the same clonal origin. Studies of the T-cell antigen receptor (TCR) gene configuration including the TCR beta, gamma, and delta loci showed that none of them was identical between KOPN30bi and S1. The TCR delta region was rearranged on both of the alleles in KOPN30bi and was deleted on both alleles in S1 indicating that KOPN30bi was not derived from S1. Polymerase chain reaction analysis, using an oligonucleotide probe corresponding to the N region sequence of the V gamma-J gamma juncture of KOPN30bi, indicated that only 0.1% of the blast cells corresponded to KOPN30bi. Thus molecular diversification of dominant subclones in vivo and in vitro was shown in Ph-positive ALL.

Base Sequence↗
PubMed1992

Detection of antistreptolysin O antibody: application of an initial rate method of latex piezoelectric immunoassay.

Latex plezoelectric immunoassay (LPEIA) is a new latex immunoassay using a plezoelectric quartz crystal (Kurosawa et al. Chem. Pharm. Bull. 1990, 38, 1117). This assay requires no immobilization of antigen or antibody on an electrode surface of a plezoelectric crystal, while the immobilization is indispensable for ordinary immunoassays using a plezoelectric crystal as a microbalance. The present paper improves a previous method (end-point analysis) by introducing the initial rate method using a batch cell; reduction of assay volume (1.2 mL) and shortening of assay time (2-3 min) were achieved. This assay was applied to the detection of antistreptolysin O antibody (ASO) in serum. The frequency change was proportional to the ASO concentration up to 1040 IU mL-1, and the method has good sensitivity for actual clinical application. The volume of serum required for the assay was 0.02 mL. Twenty-four clinical specimens were analyzed with this LPEIA, and the values obtained were compared with those obtained with a turbidimetric latex agglutination method. The correlation coefficient between these values was 0.950 (P < 0.01).

Agglutination↗
PubMed1992

Serum granulocyte colony-stimulating factor in patients with repeated infections.

We have already reported significant elevation of serum granulocyte colony-stimulating factor (G-CSF) in the acute phase of infection. In this study, we compared the responses to infection between patients with frequently repeated infection (repeaters) and others (non-repeaters). We examined the clinical data and serum G-CSF levels in 48 patients with acute infections. Serum G-CSF levels were significantly lower in repeaters than in non-repeaters (197.7 +/- 370.0 vs. 1014.1 +/- 924.4 pg/ml. P less than 0.001). There were no significant differences in age, serum total protein, or cholinesterase between the groups, but serum albumin was significantly lower in repeaters than in non-repeaters (2.87 +/- 0.5 vs. 3.31 +/- 0.4 g/dl. P less than 0.005). It is suggested that administration of recombinant G-CSF may be useful for patients with repeated infections.

Aged↗
PubMed1992

Plasma-polymerized allylamine film used as a new solid phase in immunoradiometric assay (IRMA): effect of antibody (F(ab')2 fragment) concentration on dose response in two-site IRMA.

Allylamine (ALAM) film was plasma-polymerized on a flat glass (referred to as ALAM(GLA): GLA refers to a flat glass plate) for use as a solid phase in two-site immunoradiometric assay (two-site IRMA). Adsorption of F(ab')2 anti-human immunoglobulin G [formula: see text] to ALAM(GLA) was larger than adsorption on a polyvinyl chloride plate (referred to as PVC). Contrary to the expectation that the dose response for human IgG (hIgG) on ALAM (GLA) was better than that on PVC, the dose responses on both solid phases were the same. This phenomenon was independent of molecular size of the antigen (Ag) (hIgG or Fc fragment of hIg G (hIgG-Fc)) and also the reaction with protein A (pA). Because direct measurements of binding with 125I-labeled hIgG (hIgG*) or hIgG-Fc (hIgG-Fc*) showed no difference between ALAM(GLA) and PVC, the phenomenon was not due to the second step in the system of two-site IRMA (an Ag--Ab reaction (Ab refers to antibody)). These results indicated that the phenomenon was due to the first step (the adsorption of [formula: see text] to a solid phase). When the concentration of [formula: see text] immobilized on the solid phases was lowered, a significant increase in the dose response was observed for ALAM(GLA).

Adsorption↗
PubMed1992

[Activation of complement and serial changes of anaphylatoxin (C3a, C5a) in patients for open-heart surgery using a membrane oxygenator].

Activation of complement and serum changes in anaphylatoxin (C3a and C5a) were studied in 8 patients who underwent open-heart surgery using a membrane oxygenator. C1 esterase inhibitor (C1-EI), C3, C5, CH50, C3a and C5a were measured serially at 7 points. C1-EI, C3, and C5 were measured by single radial immunodiffusion, CH50 by Mayer's method, and C3a and C5a by radioimmunoassay. Levels of C1-EI, C3 and C5 decreased significantly from 10 min after initiation to 120 min after the end of CPB compared with base line values. Degree of activation of complement increased in proportion to duration of CPB. Significant decreases of C3 and C5 continued until first postoperative day. Level of C3a increased significantly 10 min after initiation of CPB, and gradually increased till immediately after the end of CPB, when the level was maximum (4625 +/- 560 ng.ml-1) among 7 points. Level of C3a decreased gradually till 120 min after end of CPB. C5a was not detected during whole course. No patient showed respiratory distress of pulmonary edema. In conclusion, membrane oxygenator activated classical pathway of complement at 10 min after initiation of CPB. C3a increased significantly from 10 min after initiation of CPB to 120 min after end of CPB, but C5a was not detected at all during the whole course. The significant activation of complement continued till first postoperative day.

Aged↗
PubMed1991

The value of RI scintigraphy and angiography in small intestinal bleeding--report of eight cases.

We retrospectively reviewed eight cases of small intestinal bleeding and assessed the value of RI scintigraphy and angiography in diagnosing the bleeding site. The patients' average age was 56.2 years. Chief complaints was melena of variable degree. In most cases neither upper endoscopy nor colonoscopy was diagnostic. RI scintigraphy (Tc-99 labeled HSA) showed 75% of positive rate whereas angiography showed 66.7% (4/6) of positive rate. All four cases of leiomyosarcoma and leiomyoma demonstrated hypervascular stain and/or extra-vasation in angiography whereas RI scintigraphy failed to detect active GI bleeding in 2 of the 4 cases. Therefore angiography was considered useful for the detection of bleeding from leiomyoma and leiomyosarcoma which are often hypervascular. Scintigraphy is thought of most value in the demonstration of small amount of bleeding with minimum vascular abnormality.

Adult↗