3376
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Takahashi K, Jiang XC, Sakai N, Yamashita S, Hirano K, Bujo H, Yamazaki H, Kusunoki J, Miura T, Kussie P. A missense mutation in the cholesteryl ester transfer protein gene with possible dominant effects on plasma high density lipoproteins. J Clin Invest 1993; 92:2060-4. [PMID: 8408659 PMCID: PMC288375 DOI: 10.1172/jci116802] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Plasma HDL are a negative risk factor for atherosclerosis. Cholesteryl ester transfer protein (CETP; 476 amino acids) transfers cholesteryl ester from HDL to other lipoproteins. Subjects with homozygous CETP deficiency caused by a gene splicing defect have markedly elevated HDL; however, heterozygotes have only mild increases in HDL. We describe two probands with a CETP missense mutation (442 D:G). Although heterozygous, they have threefold increases in HDL concentration and markedly decreased plasma CETP mass and activity, suggesting that the mutation has dominant effects on CETP and HDL in vivo. Cellular expression of mutant cDNA results in secretion of only 30% of wild type CETP activity. Moreover, coexpression of wild type and mutant cDNAs leads to inhibition of wild type secretion and activity. The dominant effects of the CETP missense mutation during cellular expression probably explains why the probands have markedly increased HDL in the heterozygous state, and suggests that the active molecular species of CETP may be multimeric.
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3377
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Kawai S, Takahashi K, Kurosawa T, Sonoda M. Light and electron-microscopical observations of the early developmental stages of Theileria sergenti in the gut of Haemaphysalis longicornis. J Vet Med Sci 1993; 55:837-9. [PMID: 8286540 DOI: 10.1292/jvms.55.837] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Morphological characteristics of the early developmental stages of Theileria sergenti in the vector tick were observed by light and electron-microscopies and compared with those of other Theileria species. Just before the repletion of nymphs, various stages of the parasite were observed in gut contents of tick by light microscopy: the spherical intra-erythrocytic stage, the ring-form stage, the spindle-shaped stage and the round-form stage. Electron microscopy revealed that the spherical intra-erythrocytic stages were 1-2 microns in diameter and were marginally located in host erythrocytes. The organisms liberated from host erythrocytes into the tick gut lumen had a large nucleus, an endoplasmic reticulum, electron dense-organelles and a double-walled, mitochondrion-like organelle. In addition ticks had ray-bodies in the gut lumen. These bodies had short protrusions containing 1-3 microtubules and a labyrinthine structure containing highly electron-dense organelles, so they were considered as the developing microgamont of T. sergenti.
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3378
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Tanaka H, Takahashi K, Ogura M. Metabolic fate of cysteine sulfur in growing rats at various dietary protein levels. J Nutr Sci Vitaminol (Tokyo) 1993; 39:507-16. [PMID: 8120674 DOI: 10.3177/jnsv.39.507] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The metabolic fate of L-[35S]cysteine was investigated in growing rats fed on diets containing graded levels of protein calorie percentages (0, 5, 10, 15, and 30 PC%) by use of purified whole egg protein at 4,100 kcal of metabolizable energy per kilogram of diet. Incorporation of radioactivity into body protein during the 12 h period after intraperitoneal injection of 35S-cysteine was about 70% of the dose in the 0 to 15 PC% group, but it decreased significantly in the 30 PC% group, showing a break point at around 15 PC% in the diet. A considerable amount of the radioactivity was recovered in the carcass soluble fraction in which the label in the taurine fraction gradually increased with increasing dietary protein levels from 0 to 30 PC%. Urinary excretion of total 35S during the 12 h period was depressed in the lower PC% groups, but it increased in the 30 PC% group, about 23% of the dose being recovered. More than 50% of the urinary radioactivity was present in the inorganic sulfate fraction, but less than 10% was in the taurine fraction. These results indicate that cysteine sulfur is preferentially utilized for body protein synthesis, especially in dietary protein depletion, and that the oxidation of cysteine sulfur to taurine and inorganic sulfate is elevated with higher PC% in the diet. The response pattern of cysteine sulfur metabolism to dietary protein intake resembled that of cysteine carbon metabolism which was previously reported.
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3379
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Komatsu E, Yamaguchi I, Fukuyama H, Takahashi K, Miyazawa K. Response of post-ischemic myocardium to sympathetic stimulation--relation to local norepinephrine release. JAPANESE CIRCULATION JOURNAL 1993; 57:969-78. [PMID: 8230678 DOI: 10.1253/jcj.57.969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Myocardial ischemia interrupts neurotransmission and causes the depression of norepinephrine release. However, the effects of sympathetic nerve stimulation on neurotransmission and norepinephrine release in post-ischemic myocardium are not well defined. We measured regional myocardial length and norepinephrine (NE) release during sympathetic nerve stimulation in anesthetized dogs. Dogs were divided into 2 groups: Group 1 (n = 14); sympathetic nerve stimulation, Group 2 (n = 9); pre-treatment with alpha-blockade yohimbine hydrochloride (0.2 mg/kg) followed by sympathetic nerve stimulation. The left anterior descending artery was occluded for 15 min. Sympathetic nerve stimulation was performed before coronary occlusion and after reperfusion. In group 1, the decrease in systolic shortening in the ischemic region persisted for more than 60 min. Although sympathetic nerve stimulation caused an increase in systolic shortening, it was lower than the pre-ischemic value. NE release from the post-ischemic myocardium remained decreased for 60 min. The decrease in the post-ischemic myocardial response to sympathetic nerve stimulation was associated with diminished NE release. When the cardiac sympathetic nerve was denervated with an epicardial phenol application, NE release decreased even further. In group 2, NE release did not decrease following reperfusion. These results suggest that sympathetic nerve conduction is not completely impaired in post-ischemic myocardium and that pre-synaptic alpha -2 receptors might play an important role in diminished NE release.
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3380
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Hawthorne WJ, Griffin AD, Stewart H, Yumiba T, Takahashi K, Grierson J, Chapman JR, Allen RD. Normoglycaemia in dogs after splenic vein reflux of autografted pancreatic microfragments. Transplant Proc 1993; 25:2907-8. [PMID: 8212282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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3381
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Isemura M, Kazama T, Takahashi K, Yamaguchi Y. Immunochemical localization of integrin subunits in the human placenta. TOHOKU J EXP MED 1993; 171:167-83. [PMID: 8128485 DOI: 10.1620/tjem.171.167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Localization of integrins in the human placenta was examined in comparison with those of fibronectin and laminin. In the early chorionic villi, the alpha 5 and beta 1 subunits were localized on the basal surface of villous cytotrophoblastic cells, while the alpha 6 and beta 4 subunits were distributed around the entire surface of the cytotrophoblastic cells, suggesting that these cells attach to fibronectin rather than laminin on the epithelial basement membrane. In the term placenta, the alpha 5 subunit was not detected on the epithelial cells, but the beta 6 and beta 4 subunits were detected on the basal surface of syncytiotrophoblastic cells, suggesting that these cells make use of alpha 6 beta 4 integrin to attach to the trophoblastic basement membrane. These results suggest that cells utilize the specific receptor for their attachment in correspondence to the extracellular matrix component to which they attach.
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3382
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Takizawa H, Takahashi K, Murakami T, Okada N, Okada H. Rapid transformant selection by human complement using HRF20 (CD59) cDNA as a selection marker. Eur J Immunol 1993; 23:2714-6. [PMID: 7691615 DOI: 10.1002/eji.1830231052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The 20 kDa homologous restriction factor (HRF20, CD59) prevents formation of membrane attack complexes of human complement. Transfection of the cDNA of HRF20 to heterologous cells, which are sensitive to human complement, thereby renders these cells resistant to human complement attack. This property can then be used as a selection marker of transfection. In addition, the procedure is short and can be performed within 8 h. Since only 1 h is required for incubation with complement, the damage to the transfected cells is limited compared with damage resulting from selection for drug resistance which requires 10 days or more of incubation in the presence of harmful agents.
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3383
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Yokoyama H, Shibata T, Kubota N, Matsuo R, Takahashi K. [The effects of sevoflurane anesthesia with hypothermia on ischemic brain cellular respiration]. MASUI. THE JAPANESE JOURNAL OF ANESTHESIOLOGY 1993; 42:1418-22. [PMID: 8230690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We examined the effects of sevoflurane anesthesia with hypothermia on ischemic brain cellular respiration using Wistar strain rats. Ischemia was induced by decapitation. L/P in brain increased during no anesthesia-normothermia-ischemia (1), then gradually, but not fully recovered during 2.5% sevoflurane anesthesia-normothermia-ischemia (2) and during 2.5% sevoflurane anesthesia-hypothermia-ischemia (3). Energy charge decreased during (1) and slight recovery was observed during (3). Respiratory control ratio in brain mitochondria decreased during (1) and recovery during (2) and (3) was slight. No recovery was observed in ADP/O. These findings indicate that during sevoflurane anesthesia with hypothermia, ischemic brain energy metabolism has an effect not on the mitochondrial energy producing processes but on the consuming system.
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3384
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Tsuboyama T, Takahashi K, Yamamuro T, Hosokawa M, Takeda T. Cross-mating study on bone mass in the spontaneously osteoporotic mouse (SAM-P/6). BONE AND MINERAL 1993; 23:57-64. [PMID: 8274880 DOI: 10.1016/s0169-6009(08)80091-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Genetic control of bone mass in the spontaneously osteoporotic mouse (SAM-P/6) was examined by classical cross-mating experiments, in which SAM-P/2 with a high bone mass was used as a control. Femoral bone mass corrected by size (= bone density) was assayed photometrically. F1 hybrids exhibited intermediate values between those of the two parental strains, i.e. higher than SAM-P/6 and lower than SAM-P/2. F2 hybrids showed a more widely distributed pattern with a mean value quite similar to that of F1 hybrids. The values for backcrosses were between those of F1 and the respective parental strains. They did not show segregations expected in cases of a single-gene control. Numerical analysis of data distribution in each generation suggested that strain-specific bone mass in these strains of mice is inherited as a polygenic characteristic and controlled by a relatively small number of genes.
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3385
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Hara S, Imai Y, Murakami M, Mori H, Takahashi K, Kudo I, Naraba H, Oh-ishi S, Inoue K. Dynamics and participation of type II phospholipase A2 in rat zymosan-induced pleurisy. J Biochem 1993; 114:509-12. [PMID: 8276761 DOI: 10.1093/oxfordjournals.jbchem.a124208] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Intrapleural injection of zymosan into rats induces acute inflammation characterized by plasma leakage and cellular influx. The level of type II phospholipase A2 (PLA2) increased in the pleural fluid as well as in exudating leukocytes after the injection of zymosan. Rather low PLA2 activity was found in cell lysates, though treatment of such lysates at low pH increased the PLA2 activity drastically. The appearance of "acid-extracted" PLA2 activity in leukocytes preceded that of the extracellular enzyme activity, suggesting that pleural leukocytes might be one of the origins of the extracellular enzyme. Treatment of exudating pleural leukocytes with purified rat type II PLA2 elicited the production of prostaglandin E2, but not platelet-activating factor appreciably. These findings indicate that type II PLA2 might play a role in the progression of inflammation through the production of eicosanoids in the present inflammation model.
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3386
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Tsutsui H, Sugioka Y, Takaku F, Yamamura H, Asano S, Minami S, Wakimoto N, Takahashi K, Ikeda Y, Tachibana S. [A double-blind dose ranging study of weekly subcutaneous administration of rHuEPO (KRN5702) on post-phlebotomy anemia of patients scheduled for predeposit autologous blood transfusion (multicenter late PhII study)]. NIHON SEIKEIGEKA GAKKAI ZASSHI 1993; 67:919-34. [PMID: 8263364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Preoperative blood reservation for autologous blood transfusion generally causes anemia. We performed a double blind controlled study to determine the optimal dose of subcutaneous rHuEPO (recombinant human erythropoietin, KRN5702) for preventing preoperative anemia due to blood reservation. Patients received KRN5702 subcutaneously once a week in a doses of 12000, 24000 or 36000 IU by a double blind technique. After storage of 1200 ml of their own blood right before surgery, their hemoglobin (Hb) averaged about 1 and was about 0.5 g/dl lower than the level before administration of KRN5702 in doses of 12000 and 24000 IU, respectively. This fall was significant. In patients receiving KRN5702 in a dose of 36000 IU, the level of Hb rose instead of a fall; Hb immediately before surgery was 1.1% higher than that before administration which, however, was not significant. This elevation indicates a possibility of abnormal elevation of Hb at this dose. The mean Hb value right before surgery was significantly lower in patients receiving 12000 IU KRN5702 than in patients of the other two groups. The recovery rate of Hb was an indicator to reflect improvement of anemic conditions, and increased as the dose increased after the blood reservation. The rate in the 12000 IU group was significantly lower than that in the other two groups; there was not much difference between the other two rates. We estimated that to reserve 1200 ml of autologous blood, 24000 IU of KRN5702 is adequate but not excessive. One patient receiving 24000 IU showed side effects including an elevation of body temperature, rash, and edema.
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3387
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Hosokawa M, Ashida Y, Matsushita T, Takahashi K, Takeda T. Persistent hyaloid vascular system in age-related cataract in a SAM strain of mouse. Exp Eye Res 1993; 57:427-34. [PMID: 8282028 DOI: 10.1006/exer.1993.1144] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The cataractogenesis of age-related cataract in a strain of Senescence-Accelerated Mouse; SAM-P/9 was investigated. In the mature cataract, funnel-shaped tissue of the persistent hyaloid vascular system extended from the retinal papilla and covered the extremely protruding posterior pole of the cataractous lens, as seen using a stereomicroscope. Longitudinal examination of the eyes with transparent lenses using an ophthalmoscope revealed that the hyaloid vascular system persisted in about 90% of the 5-week-old mice, at least unilaterally. The eyes with transparent lenses in some old mice retained this tissue and a retrospective study revealed that cataract never occurred in eyes without this tissue. Microphthalmos was not observed. Histologically, in the eyes with transparent lenses, the posterior lens capsule covered with a hyaloid vascular system became very thin but only a few lens fibre cells just inside the capsule had swelled. In the lens of the mature cataract or even with initial changes, the lens capsules ruptured. Electron microscopic examination showed that the persistent hyaloid vascular system was tissue consisting of capillary and mesenchymal cells. These observations suggest that the persistent hyaloid vascular system is a necessary but not sole factor for age-related cataract formation in SAM-P/9, and that other age-related factors probably have a role.
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3388
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Hashimoto-Kumasaka K, Takahashi K, Tagami H. Electrical measurement of the water content of the stratum corneum in vivo and in vitro under various conditions: comparison between skin surface hygrometer and corneometer in evaluation of the skin surface hydration state. Acta Derm Venereol 1993; 73:335-9. [PMID: 7904396 DOI: 10.2340/0001555573335339] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Two commercially available electrical instruments which evaluate the hydration state of the skin surface were compared in in vitro and in vivo experiments. The skin surface hygrometer (Skicon-200) employs high-frequency conductance, whereas the corneometer (CM 420, CM 820) uses electrical capacitance to determine the level of hydration. In a simulation model of in vivo stratum corneum (SC), the high frequency conductance device showed a much closer correlation with the hydration state of the surface SC (r = 0.99) than the capacitance device (r = 0.79), suggesting that the former can accurately assess the hydration dynamics of SC, particularly that due to the accumulation of easily releasable secondary bound water and free water. Both devices were insensitive to changes of hydration taking place in deeper viable skin tissues, e.g. the accumulated tissue fluids in suction blisters. Although the capacitance device correlated poorly with the hydration dynamics in normal SC, its sensitivity to changes occurring in extremely dry skin, such as scaly psoriatic lesions, suggests its measurements characteristics at an extremely low state of hydration, consisting of mostly bound water, such as noted in pathologic SC.
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3389
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Gong BJ, Mabuchi K, Takahashi K, Nadal-Ginard B, Tao T. Characterization of wild type and mutant chicken gizzard alpha calponin expressed in E. coli. J Biochem 1993; 114:453-6. [PMID: 8276752 DOI: 10.1093/oxfordjournals.jbchem.a124197] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Calponin is a thin filament-associated protein that is implicated in the regulation and maintenance of smooth muscle contraction. Molecular cloning of chicken gizzard calponin indicated the presence of two isoforms, alpha and beta, the expression of the alpha-isoform being uniformly more abundant in various smooth muscle tissues [Takahashi, K. & Nadal-Ginard, B. (1991) J. Biol. Chem. 266, 13284-13288]. For the long-range goal of understanding of the structure and function of calponin, we have started bacterial expression and site-directed mutagenesis of alpha calponin. The amino acid composition and N-terminal sequence of the recombinant alpha calponin were found to be identical to those deduced from its nucleotide sequence. Recombinant alpha calponin is capable of binding to calmodulin, troponin C, tropomyosin, and actin, and of inhibiting skeletal muscle acto-subfragment-1 ATPase activity. A mutant alpha calponin with a replacement in the putative inhibitory region (residues 146-171) has impaired ability to inhibit the acto-subfragment-1 ATPase activity, suggesting that this region of calponin may be involved in the modulation of the actin-myosin interactions.
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3390
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Yonekubo A, Honda S, Okano M, Takahashi K, Yamamoto Y. Dietary fish oil alters rat milk composition and liver and brain fatty acid composition of fetal and neonatal rats. J Nutr 1993; 123:1703-8. [PMID: 8410361 DOI: 10.1093/jn/123.10.1703] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
This study was performed to determine the effects of dietary fish oil rich in docosahexaenoic acid [22:6(n-3)] on the milk composition of maternal rats and tissue fatty acid composition of fetal and neonatal rats. The fatty acid composition of dam's milk was affected by the dietary fat. The level of 22: 6(n-3) in the milk of dams fed the fish oil-containing diet was severalfold higher than that of dams fed the diet that did not contain fish oil, and the levels of 22: 6(n-3) in the phospholipids of the livers and brains of fetuses and pups of the fish oil-fed group were higher than those in fetuses and pups of the group that did not receive fish oil. These findings suggest that a high level of 22:6(n-3) in the livers and brains of fetal and neonatal rats can be achieved by intake of fish oil by the dams.
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3391
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Uchida E, Katoh N, Takahashi K. Appearance of haptoglobin in serum from cows at parturition. J Vet Med Sci 1993; 55:893-4. [PMID: 8286556 DOI: 10.1292/jvms.55.893] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Haptoglobin (Hp) concentrations were evaluated in 42 cow sera at around parturition by single radial immunodiffusion using anti-cow Hp rabbit serum. At parturition, Hp was detected in 31 of 42 cows. The detection rate (74%) was significantly higher than those before (0-10%) and after parturition (5-21%). At parturition, serum concentrations of cortisol and non-esterified fatty acids were significantly higher than those before and after parturition. A significantly lower concentration of serum triglycerides at parturition, compared to the values before parturition, was also observed. From these results, Hp is considered to be associated with fatty liver development of cows, because fatty liver particularly occurs in the peripartum period.
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3392
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Takahashi K, Suzuki K. Association of insulin-like growth-factor-I-induced DNA synthesis with phosphorylation and nuclear exclusion of p53 in human breast cancer MCF-7 cells. Int J Cancer 1993; 55:453-8. [PMID: 8375929 DOI: 10.1002/ijc.2910550322] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Human breast cancer MCF-7 cells, growth-arrested by serum starvation, were stimulated with recombinant human insulin-like growth factor-I (IGF-I). An increase in DNA synthesis was induced 20 hr later, which was as effective as that induced by serum. The increase in DNA synthesis was significantly inhibited either by antibody to the IGF-I receptor or by the tyrosine kinase inhibitor, methyl-2,5-dihydroxycinnamate (2,5-MeC). The IGF-I-induced DNA synthesis coincided with an elevated level of phosphorylation of p53 on tyrosine and an alteration in the subcellular distribution of the protein from the nucleus to the cytoplasm. Whereas the increases in DNA synthesis and p53 phosphorylation were inhibited by antibody to the IGF-I receptor and by 2,5-Mec, the nuclear exclusion of p53 was prevented by the antibody and also, although not significantly, by 2,5-Mec. The results suggest that growth stimulation of MCF-7 cells by IGF-I is accompanied by tyrosine phosphorylation and nuclear exclusion of p53.
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3393
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Hashimoto A, Nishikawa T, Oka T, Hayashi T, Takahashi K. Widespread distribution of free D-aspartate in rat periphery. FEBS Lett 1993; 331:4-8. [PMID: 8405408 DOI: 10.1016/0014-5793(93)80286-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have identified and quantified free D-aspartate in adult rat peripheral organs using gas chromatographic-mass spectrometric and high-performance liquid chromatographic techniques. The level of free D-aspartate was highest in the adrenal, testis, spleen and pituitary, followed by the thymus, lung, ovary, placenta, pancreas and heart, and below the detection limit in the kidney, liver, brain, muscle and serum. These data provide the first evidence that a high level of free D-aspartate widely occurs in the adult rat periphery and suggest that the D-amino acid may be an endogenous substrate for D-aspartate oxidase.
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3394
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Fukunaga M, Takahashi K, Badr KF. Vascular smooth muscle actions and receptor interactions of 8-iso-prostaglandin E2, an E2-isoprostane. Biochem Biophys Res Commun 1993; 195:507-15. [PMID: 8396920 DOI: 10.1006/bbrc.1993.2075] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
8-iso-PGE2, an E2-isoprostane, decreased GFR and RPF dose-dependently in rats, but with lesser potency than 8-epi-PGF2 alpha, an F2-isoprostane. This effect was abolished by SQ29,548. 8-iso-PGE2 displaced [3H]SQ29,548 or [125I]BOP binding in aortic smooth muscle cells with the affinity rank order of SQ29,548 > = I-BOP > U46,619 > 8-iso-PGE2 > PGF2 alpha, while it activated phospholipase C with a potency greater than those of I-BOP or U46,619 and lesser than that of 8-epi-PGF2 alpha. We concluded that 8-iso-PGE2 is a renal vasoconstrictor linked to phosphoinositide metabolism. Its vascular smooth muscle contractile actions are likely mediated through activation of putative thromboxane A2 receptor-like "isoprostane receptors."
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MESH Headings
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/physiology
- Binding, Competitive
- Blood Pressure/drug effects
- Bridged Bicyclo Compounds/metabolism
- Bridged Bicyclo Compounds, Heterocyclic
- Cells, Cultured
- Dinoprostone/analogs & derivatives
- Dinoprostone/pharmacology
- Enzyme Activation
- Fatty Acids, Unsaturated/metabolism
- Glomerular Filtration Rate/drug effects
- Hydrazines/metabolism
- Inositol 1,4,5-Trisphosphate/metabolism
- Isomerism
- Isoprostanes
- Kidney/blood supply
- Kinetics
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Phospholipases/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Prostaglandin/drug effects
- Receptors, Prostaglandin/metabolism
- Receptors, Prostaglandin E
- Receptors, Thromboxane/antagonists & inhibitors
- Regional Blood Flow/drug effects
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3395
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Kakei N, Ichinose M, Tsukada S, Tatematsu M, Tezuka N, Yahagi N, Matsushima M, Miki K, Kurokawa K, Takahashi K. Omeprazole, a proton pump inhibitor, reduces the secretion, synthesis and gene expression of pepsinogen in the rat stomach. Biochem Biophys Res Commun 1993; 195:997-1004. [PMID: 7690564 DOI: 10.1006/bbrc.1993.2143] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Omeprazole, a proton pump inhibitor, dose-dependently inhibited pepsinogen secretion as well as acid secretion in the rat glandular stomach. The reduction in the secretion was rapid and was followed by a decrease in the mRNA levels. The inhibitory effect of omeprazole on pepsinogen secretion and its effect on the mRNA level showed similar dose-response relationship, suggesting that pepsinogen secretion and the gene expression are regulated coordinately. Consistent with the reduction in the mRNA levels, protein synthesis was reduced. However, intracellular stores of pepsinogen increased in pepsinogen-producing cells, indicating that the inhibitory effect of omeprazole on pepsinogen secretion is greater than on its synthesis. Reducing the secretion, synthesis and gene expression of pepsinogen, omeprazole has a potent effect on pepsinogen-producing cells in vivo, as well as on parietal cells, in the rat glandular stomach.
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3396
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Takahashi K, Tsuchida K, Tanabe Y, Masu M, Nakanishi S. Role of the large extracellular domain of metabotropic glutamate receptors in agonist selectivity determination. J Biol Chem 1993; 268:19341-5. [PMID: 8103516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Metabotropic glutamate receptors consist of at least six different subtypes termed mGluR1-mGluR6. They belong to the family of G protein-coupled receptors and commonly possess an unusually large extracellular domain preceding the seven transmembrane segments. mGluR1 and mGluR2 show similar affinities for L-glutamate but distinct patterns in their responsiveness to quisqualate and trans-1-amino-1,3-cyclopentane-dicarboxylate (tACPD). To assign structural determinants for the different agonist selectivities, we constructed a series of chimeric receptors at the extracellular domains of mGluR1 and mGluR2 and determined their agonist selectivities by measuring their electrophysiological responses to L-glutamate, quisqualate, and tACPD in Xenopus oocytes. Replacement of the extracellular domain up to about one-half of the amino-terminal extracellular domain of mGluR1 with the corresponding portion of mGluR2 generated a pattern of the agonist selectivity characteristic of mGluR2. The acquirement of this property in agonist selectivity was further indicated by the selective responses of these chimeric receptors to an mGluR2-specific agonist, (2S,1'R,2'R,3'R)-2-(2,3-dicarboxycyclopropyl)glycine. This investigation demonstrates that the extracellular domain of mGluR is critical in determining agonist selectivity and that the mode of determination of agonist selectivity of mGluR is different from that of other G protein-coupled receptors for small molecule transmitters.
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3397
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Osada Y, Tsuchimoto M, Fukushima H, Takahashi K, Kondo S, Hasegawa M, Komoriya K. Hypouricemic effect of the novel xanthine oxidase inhibitor, TEI-6720, in rodents. Eur J Pharmacol 1993; 241:183-8. [PMID: 8243554 DOI: 10.1016/0014-2999(93)90201-r] [Citation(s) in RCA: 122] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We investigated the xanthine oxidase/xanthine dehydrogenase inhibitory activity and hypouricemic effect of a newly synthesized xanthine oxidase/xanthine dehydrogenase inhibitor, TEI-6720, 2-(3-cyano-4-isobutoxyphenyl)-4-methyl-5-thiazole-carboxylic acid, and compared its effects with those of allopurinol in rodents. TEI-6720 was found to inhibit bovine milk xanthine oxidase, and mouse liver and rat liver xanthine oxidase/xanthine dehydrogenase with IC50 values of 1.4, 1.8 and 2.2 nM, respectively. On bovine milk xanthine oxidase, TEI-6720 exhibited mixed-type inhibition and the Ki value was 0.7 nM. TEI-6720 displayed prolonged urate-lowering activity in normal mice and rats. We evaluated the hypouricemic effect of TEI-6720 on hyperuricemia induced by the uricase inhibitor, potassium oxonate (250 mg/kg s.c., 1 h before the test drugs), and measured the total molarity of both serum allantoin and urate in rats. Oral TEI-6720 and allopurinol had a hypouricemic effect 2 h after their administration to oxonate-pretreated rats with ED50 values of 1.5 and 5.0 mg/kg, respectively. Both compounds also reduced the combined molarity of uric acid and allantoin in rats. The ED50 values of TEI-6720 and allopurinol were 2.1 and 6.9 mg/kg p.o., respectively. These results suggest that TEI-6720 may be useful for the treatment of hyperuricemia.
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3398
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3399
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Suzuki H, Takahashi K, Shibahara S. [Molecular genetics of neurofibromatosis type 1]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1993; 51:2457-2461. [PMID: 8411728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The gene responsible for neurofibromatosis type 1 (NF1) encodes a protein similar to GTPase-activating protein (GAP) for the products of ras protooncogenes. Since NF1 protein possesses GAP-like activity, it is suggested that NF1 protein plays a role in the regulation of ras-mediated signal transduction. Impaired function of NF1 protein could therefore, lead to abnormal growth or differentiation of neural crest-derived cells in NF1 patients. Mutations of NF1 gene are also found in sporadic tumors not associated with NF1, supporting the hypothesis that NF1 gene acts as a tumor suppressor gene.
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3400
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Takahashi K, Sakoda R, Yamasaki H, Uchida A, Yoshino K, Kitao M. Evaluation of sperm fertilizing capacity using the determination of acrosome reaction. ASIA-OCEANIA JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1993; 19:235-40. [PMID: 8250755 DOI: 10.1111/j.1447-0756.1993.tb00379.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To evaluate the usefulness of the determination of acrosome reaction (AR) at 2 and 4 hours of incubation for predicting sperm fertilizing capacity in vitro, semen samples obtained from 45 partners of couples participating in the IVF (in vitro fertilization) program were examined. The population was divided into 2 groups, depending on the fertilization rate in the IVF program: Group A, with a good fertilizing capacity (> or = 50% fertilized oocytes); and Group B, with a poor fertilizing capacity (< 50% fertilized oocytes). The rate of acrosome reaction (%AR) was examined using the fluorescein isothiocyanate-conjugated Concanavalin A lectin method. The efficacy of this procedure was compared with that of the zona-free hamster oocyte human sperm penetration assay (SPA) and sperm characteristics (SC) that appear in routine semen analysis. The sensitivities in the test of AR, SPA and SC were 91%, 86% and 82%, respectively. However, their specificities were 83%, 48% and 43%, respectively. Therefore, the screening procedure using the determination of acrosome reaction might be a useful tool in predicting IVF results.
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