Biomedical subjects
Publications and source records attributed to Y Komatsu.
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The Kampo (Japanese herbal) medicine "Juzen-Taiho-To" (TJ-48), which was prepared by decocting a concoction (formula), contains ten kinds of herbs and has several immunostimulating activities. In order to determine the contribution of each herbal component, the complement-activating and mitogenic activities of the hot water extract as well as the polysaccharide fraction from each herb were tested. Hot water extracts of Glycyrrhizae radix, Astragali radix, and Atractylodes lanceae rhizoma showed significant mitogenic activity whereas that of Cinnamomi cortex showed potent complement-activating activity. However, the exclusion of any single component herb whether active or not on its own did not result in a loss or an increase of the overall activity of TJ-48. The polysaccharide fraction from Glycyrrhizae radix showed the most potent of both activities among the same fractions from the other nine herbs, and reduced both activities after periodate oxidation, thus indicating that the carbohydrate moiety may contribute to both activities.
1. The induction mechanism of long-term potentiation (LTP) in developing visual cortex was studied by recording intracellular responses from layer III-IV cells in slice preparations of kitten visual cortex at 30-40 days after birth. 2. Strong stimulation of white matter produced a late depolarizing response after an orthodromic action potential. This depolarizing response was abolished by membrane depolarization or hyperpolarization caused by current injection through the recording electrode. In addition, this response was reduced by bath application of a low concentration (100 microM) of Ni2+ without any changes in the rising slope of the excitatory postsynaptic potential (EPSP) or orthodromic action potential. This suggests that this response is mediated by low-threshold Ca2+ channels (LTCs). 3. The involvement of LTCs in the induction of LTP was tested. White matter was stimulated at 2 Hz for 15 min as a conditioning stimulus to induce LTP, and the resultant changes in EPSPs were tested by low-frequency (0.1 Hz) stimulation of white matter. Conditioning stimulation produced a large N-methyl-D-aspartate (NMDA) receptor-mediated depolarizing response in these cells, which obscured the presence of the late depoliarzation. Therefore the test was conducted in a solution containing an NMDA antagonist 2-amino-5-phosphonovalerate (APV). 4. Weak conditioning stimulation, which evoked no LTC responses, never induced LTP; whereas strong conditioning stimulation, which evoked LTC responses, always induced LTP. Strong conditioning stimulation failed to induce LTP when LTC responses were prevented either by membrane depolarization or hyperpolarization or by a bath application of 100 microM Ni2+. 5. In a solution without APV, the application of Ni2+ also prevented the induction of LTP. 6. When cells were impaled by an electrode containing a Ca2+ chelator 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), LTP was never induced, even though LTC responses were evoked by conditioning stimulation. These results indicate that Ca2+ influx into postsynaptic cells through LTCs induces the LTP. 7. The responses mediated by LTCs, which were evoked by the injection of current pulses into the cells, were maximum at the critical period of visual cortical plasticity, suggesting that LTCs in postsynaptic cells regulate the plastic changes in developing visual cortex.
We isolated the human C-type natriuretic peptide gene and identified the peptide in the brain. The human C-type natriuretic peptide gene appeared to be composed of at least two exons and one intron. In the 5'-flanking region, there is an array of cis elements (an inverted CCAAT box, two GC boxes, and a cyclic AMP response element-like sequence) that is not present in upstream sequences of the atrial and brain natriuretic peptide genes. Analysis of the deduced amino acid sequence revealed that human prepro C-type natriuretic peptide comprises 126 amino acids and that the C-terminal 22-residue peptide (G-L-S-K-G-C-F-G-L-K-L-D-R-I-G-S-M-S-G-L-G-C) preceded by Lys-Lys is identical to the porcine counterpart. However, replacement of two amino acids took place in the C-terminal 53-residue sequence, corresponding to another endogenous form of the peptide. Reverse-phase high-performance liquid chromatography coupled with a radioimmunoassay for C-type natriuretic peptide demonstrated that it occurs in the human brain. C-type natriuretic peptide-like immunoreactivity was detected in discrete regions of the human brain, and its level was 10-fold higher than the atrial and brain natriuretic peptide levels, raising the possibility that C-type natriuretic peptide is the major natriuretic peptide in the human brain.
To elucidate the physiological and pathophysiological roles of the natriuretic peptide family in vascular smooth muscle cells, in which the natriuretic peptide family is implicated in growth inhibition as well as vasorelaxation, we have examined the phenotype-related expression of three kinds of natriuretic peptide receptors in rat aortic smooth muscle cells. The expression of natriuretic peptide receptors at the mRNA level was studied by Northern blot hybridization, and the expression at the protein level was determined by the cGMP production method and receptor binding assay. In intact aortic media, atrial natriuretic peptide (ANP)-A receptor mRNA and ANP-B receptor mRNA were detected, and the potency of cGMP production by ANP was at least two orders of magnitude stronger than that by C-type natriuretic peptide. Clearance receptor mRNA was undetectable, and only a small amount of the clearance receptor was detected by the binding assay in intact aortic media. By contrast, in cultured aortic smooth muscle cells at the first, fifth, and 17th passages, the ANP-B receptor mRNA level markedly increased; meanwhile, the expression of the ANP-A receptor mRNA became undetectable. C-type natriuretic peptide was one order of magnitude more potent than ANP in cGMP production in cultured aortic smooth muscle cells. The clearance receptor density and its mRNA level increased tremendously in these cultured cells. These results demonstrate that the marked phenotype-related alteration occurs in the expression of natriuretic peptide receptors in rat aortic smooth muscle cells.
C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, is thus far known to be distributed mainly in the central nervous system and is considered to act as a neuropeptide, in contrast to atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), which act as cardiac hormones. Recently, we and others have demonstrated that the ANP-B receptor, which is selectively activated by CNP, is localized not only in the central nervous system but in peripheral tissues, including blood vessels. This finding has made us speculate regarding the peripheral production of CNP. In the present study, cultured endothelial cells were examined for CNP production by RIA and Northern blot analysis. CNP-like immunoreactivity was detected in the conditioned media of endothelial cells. Northern blot analysis detected CNPmRNA with a size of 1.2 kb. In addition, transforming growth factor (TGF)-beta, one of the key growth factors for vascular remodeling, markedly stimulated the expression of CNPmRNA and induced a tremendous increase in CNP secretion. We could also detect CNP transcript in the bovine thoracic aorta using the reverse transcription-polymerase chain reaction method. The present study demonstrates the endothelial production of CNP and suggests that a member of the natriuretic peptide family may act as a local regulator in vascular walls. Since evidence for the pathophysiological importance of the vascular renin-angiotensin system has been accumulating and the natriuretic peptide system is known to be antagonistic to the renin-angiotensin system, the possible existence of "vascular natriuretic peptide system" may prove to be of physiological and clinical relevance.
Endothelins (ETs) are very potent vasoconstrictive peptides and have diverse functions in both vascular and nonvascular tissues. This investigation concerns the tissue distribution and cellular localization of rat mRNAs encoding two different subtypes of ET receptors (ETA and ETB). We isolated 46 cDNA clones from a rat lung cDNA library by hybridization with the bovine ETA cDNA. The characterization of these cDNA clones indicated that they represent either the ETA or ETB cDNA. In situ and blot hybridization analyses revealed that the rat ETA mRNA is predominantly expressed in vascular smooth muscle cells of a variety of tissues, bronchial smooth muscle cells, myocardium, and the pituitary gland. There is no significant expression of ETB mRNA in vascular smooth muscle cells, and ETA, thus, plays a primary role in ET-induced vascular contraction. ETB mRNA is more widely distributed in various cell types of many tissues. Its prominent expression is seen in glial cells throughout the brain regions, epithelial cells of the choroid plexus, ependymal cells lining the ventricle, myocardium, endothelial cells of glomeruli, and epithelial cells of the thin segments of Henle's loops. Our investigation demonstrates that the mRNAs for the two subtypes of rat ET receptors show specialized expression patterns of cell types in both brain and peripheral tissues.
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The synthesis and in vitro antibacterial activity of a series of 7-[(Z)-2-aminoaryl-2-oxyiminoacetamido]-3-ammoniomethyl++ +-3-cephems are described. Variation of an oxyimino moiety with aminoaryl at the C-7 side chain and a quaternary ammonium moiety at the C-3 side chain were examined and structure-activity relationships were studied. E1040, the 3-(4-carbamoylquinuclidinio)methyl derivative of the 7-alpha-methoxyimino series of aminothiadiazolyl cephalosporins, exhibited excellent activity against both Gram-positive and Gram-negative bacteria, particularly against Pseudomonas aeruginosa, and possessed high stability to beta-lactamases.
The catalytic domain in the minus strand of the satellite RNA of tobacco ringspot virus (sTobRV(-)) assumes a hairpin-like secondary structure. This ribozyme catalyzes a cross-ligation reaction between substrate RNAs of different lengths. We constructed ribozymes to probe the activities of ligation and RNA fragment exchange.
In order to investigate whether several DNA lesions (O6-methylguanine, 8-hydroxyguanine, xanthine, an abasic site analogue and hypoxanthine) activate a c-Ha-ras gene and to determine the type of mutations induced by the DNA lesions, they were introduced into a synthetic c-Ha-ras gene by DNA cassette mutagenesis techniques. The modified genes were transfected into mouse NIH3T3 cells and the c-Ha-ras genes present in transformed cells were analysed. O6-methylguanine and xanthine induced a mutation to A, hypoxanthine induced a mutation to G. 8-hydroxyguanine and the abasic site analogue caused random mutations in the modified and adjacent positions. These results indicated that the synthetic c-Ha-ras gene is very useful for the detection of mutations caused by a DNA lesion.
Urinary kallikrein and kallikrein activity significantly decreased in cases of preeclampsia (u-kall./CRE.index 42.39 +/- 9.66 ng/mg, u-kall. act./CRE.index 0.26 +/- 0.06 ng/min/mg), and urinary kininase II and kininase activity significantly increased (u-kininase/CRE.index 10.91 +/- 1.26 x 10(-3) IU/min/mg, u-kininase act./CRE.index 506.37 +/- 178.45 pg/min/mg) when compared with those of normal gravidas from 28 weeks to 42 weeks of gestation (u-kall./CRE.index 189.31 +/- 14.17 ng/mg, u-kall. act./CRE index 1.08 +/- 0.10 ng/min/mg, u-kininase/CRE.index 6.24 +/- 0.31 x 10(-3) IU/min/mg, u-kininase act./CRE.index 15.64 +/- 0.10 pg/min/mg). Urinary FPA, B beta 5-42, alpha 2-PI, and alpha 2PI-plasmin-complex (PIC) significantly increased in preeclampsia (u-FPA/CRE.index 23.59 +/- 8.47 ng/mg, u-B beta/CRE.index 105.26 +/- 29.30 ng/mg, u-alpha 2PI/CRE.index 121.53 +/- 43.57 ng/mg, u-PIC/CRE index 278.39 +/- 60.50 ng/mg) when compared with those of normal control group (u-FPA/CRE.index 0.92 +/- 0.04 ng/mg, u-B beta/CRE.index 12.15 +/- 0.44 ng/mg, u-alpha 2PI/CRE.index 4.18 +/- 0.33 ng/mg, u-PIC/CRE.index 5.98 +/- 1.15 ng/mg). Urinary urokinase markedly increased and urinary D-dimer was detected in severe cases of preeclampsia (u-UK/CRE.index 58.20 +/- 43.69 ng/mg, u-D-dimer 54.76 +/- 9.89 ng/ml) when compared with those of normal control group. These findings suggest that deficiency in urinary kinin excretion may induce hypertension in addition to the changes of urinary coagulation-fibrinolysis system that represents the occurrence of either the endothelial cell injury in the glomerulus or the renal tulbular damage in mild cases of preeclampsia, eventually resulting in the intra-renal vascular coagulation.
The major side effect of rHuEPO is hypertension, which is reported to occur in 10-75% of adult patients. The aim of the present study is to evaluate the effect of rHuEPO on blood pressure in pediatric dialysis patients. Nine CAPD patients (mean age 7.4 +/- 3.6 years) and fourteen HD patients (mean age 13.8 +/- 5.5 years) were treated with rHuEPO. The hematocrits increased significantly from 20.7 +/- 1.8 to 28.3 +/- 4.1 in HD patients and from 19.7 +/- 2.9 to 26.7 +/- 4.4 in CAPD patients. The final maintenance dose required to correct the anemia was 47.6 +/- 11.7 units/kg/week for CAPD patients and 122.6 +/- 75.2 U/kg/week foe HD patients. Six (66.6%) out of nine CAPD patients, and five (35.7%) of fourteen HD patients developed or worsened hypertension. Younger CAPD patients tended to develop hypertension. Correction of anemia was poor in two hypertension-exacerbated patients, since rHuEPO dose increase was withheld for fear of aggravating hypertension. A four-year-old girl developed hypertensive encephalopathy after 13 months of rHuEPO therapy. No difference was observed in plasma level of aldosterone or plasma renin activity. Hypertension is observed frequently among pediatric dialysis patients treated with rHuEPO therapy. Careful monitoring and management of hypertension is required, especially in the first three months of rHuEPO therapy.
The pathogenesis, classification, diagnosis and treatment of alkalosis are described. Alkalemia is defined as an elevation in the blood pH and alkalosis refers to processes that tend to raise the pH, and divided into two types; metabolic alkalosis (a primary increase in plasma HCO3- concentration) and respiratory alkalosis (a primary decrease in PCO2). These disorders are most frequently observed in the hospitalized patients. As the critically ill-patients with severe alkalemia are often associated with high mortality, treatment should be directed to the underlying diseases and severe alkalemia should be corrected promptly.
In our previous study (Adv. Exp. Med & Biol., 247B. 569. 1989, 198B. 41. 1986, blood & vessel, 17: 51. 1986), we reported on the mechanism of coagulation-fibrinolysis system and kallikrein-kinin system in the utero-placental circulation during normal pregnancy, labor and puerperium. The samples were collected from the uterine artery (UA), uterine vein (UV) and peripheral vein (PV). In this study, we tried to elucidate the mechanism of coagulation-fibrinolysis with relation to kks by measuring of Thrombin/Antithrombin III complex (TAT), tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI) complex (tPA.PAI.C), active plasminogen activator inhibitor 1 (active PAI), alpha 2-plasmin inhibitor/plasmin complex (PIC). In 20 normal pregnant women, the levels of TAT, tPA.PAI.C and active PAI significantly increased the first trimester (TAT 4.31 +/- 2.05 ng/ml, tPA.PAI.C 39.52 +/- 17.34 ng/ml, active PAI 39.58 +/- 15.29 ng/ml, n = 20 M +/- SD P < 0.001) to the third trimester (TAT 6.39 +/- 1.93 ng/ml, tPA.PAI.C 57.94 +/- 30.80 ng/ml, active PAI 304.24 +/- 148.64 ng/ml, n = 20 M +/- SD P < 0.001) as compared with those of non-pregnant women (TAT 1.60 +/- 0.89 ng/mg, tPA.PAI.C 11.72 +/- 4.59 ng/ml, active PAI 11.53 +/- 7.48 ng/ml, n = 16 M +/- SD). In utero-placental circulation, the levels of TAT significantly increased (TAT 22.12 +/- 20.03 ng/ml n = 20 M +/- SD P < 0.001) in UV, and tPA.PAI.C and PIC. markedly increased (tPA.PAI.C 93.38 +/- 56.05 ng/ml, PIC 1.03 +/- 0.94 micrograms/ml n = 20 M +/- SD P < 0.02) in UV, but active PAI markedly decreased (active PAI 244.18 +/- 87.55 ng/ml n = 20 M +/- SD P < 0.02) as compared with those in PV (TAT 6.1 +/- 2.09 ng/ml, tPA.PAI.C 59.34 +/- 18.99 ng/ml, PIC 0.49 +/- 0.24 micrograms/ml, active PAI 349.14 +/- 157.34 ng/ml, n = 20 M +/- SD). These findings suggest that the significant increase in those complexes in UA has produced a deposition of fibrin clots in the area in contact with utero-placental blood vessel, although the marked increase in tPA.PAI.C and PIC incompletely inhibited the fibrinolytic activity of tPA by the active PAI. The kks shows a consumption of prekallikrein, LMW-kininogen and HMW-kininogen, and an overproduction of kinin in UV.
UNLABELLED: In our previous study 1), 2), 3) we reported the changes of coagulation-fibrinolysis, kallikrein-kinin system and kininase in preclampsis. In this study, we tried to obtain systemic information of chronic DIC status with regard to kallikrein-kinin system in severe preeclampsia. This systemic information was evaluated in 20 cases of normal gravidas from 28 to 42 weeks of gestation as a control by measuring plasma Thrombin/Antithrombin III complex (TAT), tissue plasminogen activator (tPA) plasminogen activator inhibitor (PAI) complex, active plasminogen inhibitor-1 (active PAI), 2PI plasmin complex (PIC). RESULTS: The levels of plasma TAT and tPA significantly increased (TAT = 10.9 +/- 8.3 ng/ml n = 24 M +/- SD P < 0.02, tPA = 6.1 +/- 3.2 ng/ml n = 10 M +/- SD P < 0.01), tPA PAI C and active PAI markedly increased (tPA PAI C = 85.07 +/- 50.01 ng/ml n = 24 P < 0.05, active PAI = 407.4 +/- 166.0 ng/ml n = 24 P < 0.205), and PIC and D-dimer = 435.1 +/- 145.2 ng/ml n = 8 M +/- SD P < 0.001) in severe preeclampsia as compared with those of normal values (TAT = 6.1 2.0 ng/ml, tPA = 3.6 +/- 1.5 ng/ml, tPA PAI C = 57.9 +/- 30.8 ng/ml, active PAI = 304.2 +/- 148.6 ng/ml, PIC = 0.49 +/- 0.24 mg/ml, D-dimer = 282.9 +/- 75.3 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)
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A clinical survey was performed on 185 cases of primary bladder cancer treated at our Department of Urology, between January, 1985 and December, 1989. Clinicopathological profiles of patients and survival rates according to these profiles were investigated. The patients were between 29 and 95 years old. The male to female ratio was 3.1 to 1. The cumulative survival rate after the first treatment was 73.3% and 71.5% at 3 and 5 years, respectively. Histologically, 17 cases were diagnosed as transitional cell carcinoma G1, 69 cases as G2 and 69 cases as G3. 5 cases were diagnosed as stage pTis, 6 cases as pTa, 41 cases as pT1, 15 cases as pT2, 9 cases as pT3a, 14 cases as pT3b and 6 cases as pT4. Stage, grade, size and type of tumors reflected the prognosis well. Significant differences were observed between the survival rates of the patients with grade G2 and grade G3, and the patients with stage T1 and stage T2. Although low-grade low-stage tumors recurred in 44% of the patients. The pathological stage showed a good relation to the grade. In particular, none of the G1 bladder tumors had muscle invasion in our series.