Biomedical subjects

M Minami

Publications and source records attributed to M Minami.

At least 127 records · Page 7Linked to original sources

PubMed2000

Increased expression of lectin-like oxidized low density lipoprotein receptor-1 in initial atherosclerotic lesions of Watanabe heritable hyperlipidemic rabbits.

A novel lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) was recently identified in bovine aortic endothelial cells. It is strongly suggested to have a potential role in the initiation and development of atherosclerosis. In this study, we have isolated cDNA clones encoding the rabbit homologue of LOX-1 by screening a rabbit placenta cDNA library. In amino acid sequence and domain structure organization, the rabbit LOX-1 is highly conserved with the human counterpart. Transfection of rabbit LOX-1 cDNA to HEK-293 cells confers on them the activity to bind and internalize oxidized low density lipoprotein. Rabbit LOX-1 was identified as a 45-kDa protein by Western blot analysis with a specific monoclonal antibody. Notably, analyses by reverse transcription-polymerase chain reaction and Western blot revealed that LOX-1 was accumulated in 8-week-old Watanabe heritable hyperlipidemic rabbit aortas compared with normal rabbit aortas. Immunostaining confirmed that the augmented expression of LOX-1 was primarily localized within the intima at the earliest stages of atherogenesis. The most prominent staining was in the endothelial cells of lesions. Furthermore, the distinctive staining of LOX-1 was identified in the endothelium of non-lesion areas of Watanabe heritable hyperlipidemic rabbit aortas. Taken together, these findings support the possibility that LOX-1 might be involved in the initiation of atherosclerosis.

Amino Acid Sequence↗

PubMed2000

Effects of cardiac natriuretic peptides on oxidized low-density lipoprotein- and lysophosphatidylcholine-induced human mesangial cell migration.

The objectives of the present study were (1) to determine whether oxidized LDL and lysophosphatidylcholine (lyso-PtdCho), a major phospholipid component of oxidized LDL, stimulate the migration of cultured human mesangial cells and (2) to investigate the possible effects on mesangial cell migration of the cardiac natriuretic peptides atrial and brain natriuretic peptide (ANP and BNP). Oxidized LDL (10 and 100 microg/mL) and lyso-PtdCho (10(-7) to 10(-5) mol/L) stimulated migration in a concentration-dependent manner. In contrast, the effects of native LDL and phosphatidylcholine were modest or nonexistent. Protein kinase C (PKC) inhibitor and downregulation of PKC activity by phorbol ester inhibited oxidized LDL- and lyso-PtdCho-induced migration. Human ANP(1-28) and human BNP-32 significantly inhibited oxidized LDL- and lyso-PtdCho-induced migration in a concentration-dependent manner. C-ANF (des-[Glu(18),Ser(19),Gly(20),Leu(21),Gly(22)]ANP(4-23)), a specific ligand for ANP clearance receptors, could not inhibit oxidized LDL- and lyso-PtdCho-induced migration. Inhibition by ANP and BNP of lyso-PtdCho-induced migration was paralleled by an increase in the cellular level of GMP. Oxidized LDL- and lyso-PtdCho-induced migrations were inhibited by 8-bromo-cGMP. The results suggest that oxidized LDL and lyso-PtdCho stimulate the migration of human mesangial cells, at least in part, through a PKC-dependent process and that ANP and BNP inhibit this stimulated migration, probably through a cGMP-dependent process.

Atrial Natriuretic Factor↗

PubMed2000

Aldose reductase inhibitor improves insulin-mediated glucose uptake and prevents migration of human coronary artery smooth muscle cells induced by high glucose.

We examined involvement of the polyol pathway in high glucose-induced human coronary artery smooth muscle cell (SMC) migration using Boyden's chamber method. Chronic glucose treatment for 72 hours potentiated, in a concentration-dependent manner (5.6 to 22.2 mol/L), platelet-derived growth factor (PDGF) BB-mediated SMC migration. This potentiation was accompanied by an increase in PDGF BB binding, because of an increased number of PDGF-beta receptors, and this potentiation was blocked by the aldose reductase inhibitor epalrestat. Epalrestat at concentrations of 10 and 100 nmol/L inhibited high glucose-potentiated (22.2 mmol/L), PDGF BB-mediated migration. Epalrestat at 100 nmol/L inhibited a high glucose-induced increase in the reduced/oxidized nicotinamide adenine dinucleotide ratio and membrane-bound protein kinase C (PKC) activity in SMCs. PKC inhibitors calphostin C (100 nmol/L) and chelerythrine (1 micromol/L) each inhibited high glucose-induced, PDGF BB-mediated SMC migration. High glucose-induced suppression of insulin-mediated [(3)H]-deoxyglucose uptake, which was blocked by both calphostin C (100 nmol/L) and chelerythrine (1 micromol/L), was decreased by epalrestat (100 nmol/L). Chronic high glucose treatment for 72 hours increased intracellular oxidative stress, which was directly measured by flow cytometry using carboxydichlorofluorescein diacetate bis-acetoxymethyl ester, and this increase was significantly suppressed by epalrestat (100 nmol/L). Antisense oligonucleotide to PKC-beta isoform inhibited high glucose-mediated changes in SMC migration, insulin-mediated [(3)H]-deoxyglucose uptake, and oxidative stress. These findings suggest that high glucose concentrations potentiate SMC migration in coronary artery and that the aldose reductase inhibitor epalrestat inhibits high glucose-potentiated, PDGF BB-induced SMC migration, possibly through suppression of PKC (PKC-beta), impaired insulin-mediated glucose uptake, and oxidative stress.

Aldehyde Reductase↗

PubMed2000

[Chemokines as mediators for intercellular communication in the brain].

Chemokines constitute a large and still growing family of structurally-related small (8-10 kDa) cytokines that have chemotactic activity for leukocytes. Recently, some receptors for chemokines were reported to be used as a co-receptor by HIV at infection. In addition to their well-established role in inflammatory response and recently-reported role as a co-receptor for HIV, recent data suggest that chemokines and their receptors physiologically and pathologically play crucial roles as the mediators for intercellular communication among the cells intrinsic to and recruited into the brain; i.e., neurons, astrocytes, microglia, endothelial cells and leukocytes. Some chemokines such as SDF-1 and fractalkine are constitutively produced in the brain, implicating that they have an important role in maintenance of CNS homeostasis or determination of the patterning of neurons and/or glial cells in developing brain and normal adult brain. Chemokines such as MCP-1, MIP-1 alpha and CINC were shown to be induced by various neuroinflammatory stimuli, suggesting that they are involved in various neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease, stroke and AIDS dementia syndrome. Chemokines and their receptors are potential targets for therapeutic intervention in neurodegenerative diseases.

Animals↗

PubMed2000

Endomorphin-1 discriminates the mu-opioid receptor from the delta- and kappa-opioid receptors by recognizing the difference in multiple regions.

Endomorphin-1 is a novel endogenous peptide that is highly selective for the mu-opioid receptor over the delta- and kappa-opioid receptors. The structural basis of high selectivity of endomorphin-1 to the mu-opioid receptor was examined using chimeric receptors between mu- and delta-opioid receptors and those between mu- and kappa-opioid receptors. The chimeric receptors were constructed by using restriction enzyme sites intrinsically possessed by or introduced to the mu-, delta- and kappa-opioid receptor cDNAs. The junctions for the construction were located at the first intracellular loop (Bbs I site), third transmembrane domain (Afl III site) and fifth transmembrane domain (Bgl II site). The competitive binding assay using chimeric receptors revealed that the region from the Bbs I site to the Afl III site, including the first extracellular loop, contributes to the discrimination between mu- and delta-opioid receptors by endomorphin-1 more than any other regions. However, the region from the Afl III site to the Bgl II site and that from the Bgl II site to the carboxy terminal also somewhat contribute to the discrimination between mu- and delta-opioid receptors. For the discrimination between mu- and kappa-opioid receptors, two regions, that is, the region from the Bbs I site to the Afl III site and that from the Bgl II site to the carboxy terminal, were shown to be important. The present results show that endomorphin-1 discriminates the mu-opioid receptor from the other two types of opioid receptors by recognizing the differences in several amino acid residues widely distributed through the receptor structure. We previously reported that DAMGO, a synthetic highly mu-selective peptide, discriminates between mu- and delta-opioid receptors by recognizing the difference in only one amino acid residue and discriminates between mu- and kappa-opioid receptors by recognizing the difference in four residues localized in the restricted region. Although both endomorphin-1 and DAMGO are mu-opioid receptor selective peptides, molecular mechanisms for mu-selectivity are different between these peptides.

Animals↗

PubMed2000

[Trends in variation within the day and between days of subjective symptoms of fatigue in adolescent males].

The purpose of this study was to clarify the trends in the variation within the day, and between days, of subjective symptoms of fatigue (SSF) in the daily life of male students. A SSF questionnaire (54 items) with guaranteed validity and reliability was administered to 104, 15-16 year-old healthy students, 3 times a day, in the morning (about 08:50), mid-day (about 12:10) and afternoon (about 16:10) for 5 days from Monday to Friday. As the main statistical analysis, two-way (day and week) ANOVA and post-hoc t tests were used. The SSF questionnaire was considered to have very high reliability because Cronbach's alpha coefficients in each survey point of time were .967-.977. SSF complaints between days were low on the whole, but complaints of drowsiness were relatively high. The trends in variation of SSF between days were greater than those within the day. The trends in variation within the day were noticeable in complaints regarding drowsiness and loss of vigor. Complaints regarding languor became high from the middle of the week to the weekend. On the other hand, SSF complaints except for languor, were high at the beginning of the week, especially on Monday and became lower after Tuesday. There is a trend in variation within the day for symptoms regarding drowsiness and loss of vigor. The trend in variation between days was confirmed for many SSFs, and was noticeable as compared to those within the day. Complaints regarding languor were high on the weekend, and SSF complaints except for languor were high at the beginning of the week, especially on Monday.

Adolescent↗

PubMed2000

[The proposal of the activities of daily living (ADL) index for institutionalized older adults].

The purpose of this study was to propose the ADL index constructed with a unidimensional scale based on item difficulty for institutionalized older adults. Six hundreds and three subjects (159 males and 444 females) were divided into the following four groups based on assisting devices for movement: G1 did not use assisting devices for movement; G2 used a stick or a walker; G3 used a wheelchair; G4 could not move. As the results of examinations from the points of the approximation of proportions, non-answer rates and agreement rates of each item according to 74 ADL items representing 9 ADL domains, the 27 ADL items were selected as utility items. The reliability and unidimensionality of the ADL index consisting of 27 items were considered to be high. As the results of examining the difficulty of items and ADL ability characteristics of each group, the ADL concerning movement and other lower limb activity in G1 and G2, and concerning changes of posture and manual activity in G3 and G4 were considered to reflect the individual differences of ADL ability, respectively. The numbers of ADL items which should first be assessed in each group were as follows: 20 items in G1; 21 items in G2; 21 items in G3; 11 items in G4.

Activities of Daily Living↗

PubMed2000

[A study of metallic mercury polluting a room after being spilled from a sphygmomanometer].

Mercury spilled from a mercurial sphygmomanometer on a hot carpet can vaporize and pollute the environment. We observed the vaporization of mercury in model experiments. Mercury (0.15g) was heated on a hot carpet and the near-by air was sampled with a midget impinger. The evaporated mercury levels were 5.0, 6.3, 8.1 and 10.0mg/m(3) at 20, 40, 60 and 80 minutes, respectively at a height of 30cm from carpet. The result indicated that even if a small quantity of mercury remained on the hot carpet, it could evaporate and pollute the indoor air. Little is known about the influence on human health of low mercury exposure, especially on children. In order not to pollute the air, we need to pay attention to mercury.

Accidents, Home↗

PubMed2000

Effects of valsartan on angiotensin II-induced migration of human coronary artery smooth muscle cells.

The migration as well as proliferation of coronary artery medial smooth muscle cells (SMC) into the intima is proposed to be an important process of intimal thickening in coronary atherosclerosis. In the current study, we examined the effects of the angiotensin type 1 receptor antagonist valsartan on angiotensin II (Ang II)-induced migration of cultured human coronary artery SMC using Boyden's chamber methods. Ang II significantly stimulated human coronary artery SMC migration in a concentration-dependent manner between 10(-6) and 10(-8) mol/l when cells of passage 4 to 6 were used. However, the migration response to Ang II was moderately decreased in cells of passage 10 to 12, and was markedly decreased in cells of passage 15 to 17, compared to that of passage 4 to 6. Ang II-induced migration was blocked by the Ang II type 1 (AT1) receptor antagonist valsartan in a concentration-dependent manner. By contrast, the Ang II type 2 (AT2) receptor antagonist PD 123319 did not affect Ang II-induced migration. Ang II modestly increased the cell number of human coronary artery SMC after a 24-h incubation. This increase in cell numbers was also clearly blocked by valsartan, but not by PD 123319. These results indicate that Ang II stimulates migration as well as proliferation via AT1 receptors in human coronary artery SMC when cells of passage 4 to 6 are used. Valsartan may prevent the progression of coronary atherosclerosis through an inhibition of Ang II-induced migration and proliferation in these cells, although in vivo evidence is lacking.

Angiotensin II↗

PubMed2000

Use of subjective estimation in motor skill tests of young children: judgment based on observation of behavior in daily life.

This study assessed what motor skill tests were appropriate by observing 636 young children's behavior in daily life (low-aged classes, M = 3.7 yr.; middle-aged classes, M = 4.7 yr.; high-aged classes, M = 5.7 yr.). A homeroom teacher and an assistant teacher estimated motor achievement as pass-or-fail, and then judged pass-or-fail based on practical testing. Estimate-re-estimate agreement, interrater agreement, and agreement between estimated values and measured values were examined for 27 items, e.g., skipping, bouncing a ball, and turning on one leg. Estimate-re-estimate agreement was high on the whole. Interrater agreement ranged from 34% to 100% for 3-yr.-olds, 21% to 100% for 4-yr.-olds, and 89% to 100% for 5-yr.-olds. Agreement between estimated values and measured values greater than 80% was found in most items for 5-yr.olds (14 items). After examining the above-mentioned agreements, 26 items were selected as possible tests to judge motor development, using a pass-or-fail, from the observation of young children's behavior in daily life.

Achievement↗

PubMed2000

Examination of force-production properties during static explosive grip based on force-time curve parameters.

The present study attempts to clarify the properties of force-time curves in the force-development phase during static explosive grip exertion and to determine force-time parameters in relation to static explosive strength. 80 healthy young males (age 17.8 +/- 2.5 yr.) exerted maximal isometric force as fast and forcefully as possible. In total, 21 variables, e.g., time to fixed level, integrated area, average force, integrated area to fixed time, force at the maximal rate of force development, and maximal rate of force development, were selected as force-time parameters. Good reliability was obtained for average force in force levels above 90% of maximal strength (.64-.93), integrated area to a fixed time of 1.0-2.0 sec. (.86-.93), force at the maximal rate of force development (.67), and maximal rate of force development (.73). In addition, these values correlated closely with maximal grip strength (r= .65-.93). Further, significant differences in maximal grip strength, average force in force levels above 90% of maximal strength, integrated area to fixed time, and force at the maximal rate of force development were found among three groups categorized by average force in force levels of maximal strength. These results suggested that individual differences were present in the force-time curve patterns during the force-development phase of static explosive grip exertion and that the average force in force levels of maximal strength might be a valuable tool for evaluating static explosive strength.

Adolescent↗

PubMed2000

[Opioid receptors].

Explore the source record for details and available documents.

Analgesics, Opioid↗

PubMed2000

[A case report of central respiratory failure due to hemimedullary syndrome].

A hemimedullary infarction, in which both medial and lateral medullary infarctions occur simultaneously, is a rare cerebrovascular disease. Pontomedullary lesions often cause central respiratory failure, and the majority of central respiratory failures are due to bilateral pontomedullary lesions. We report a 66-year-old man with central respiratory failure due to a hemimedullary infarction detected by magnetic resonance imaging. He was admitted to our hospital on March 7, 1998, because of a sudden onset of dysarthria, and both numbness and weakness on his left side. Soon after arriving at the hospital, his spontaneous respiration ceased. Therefore, he was intubated and artificial ventilation was started. Pertinent neurological abnormalities on admission consisted of dysarthria, dysphagia, right Horner's sign, right gaze evoked horizontal nystagmus, right soft palate palsy, and tongue deviation to the right. In addition, left hemiparesis, left Babinski's sign, sensory impairment on the left side including the face, and central respiratory failure were noted. Although voluntary respiration recovered in 12 days, sleep apnea continued for 5 months, which was considered to be due to the automatic respiratory failure. An important feature of this patient was that the hemimedullary infarction caused the central respiratory failure. To our knowledge, this is the third patient whose central respiratory failure occurred because of a hemimedullary infarction.

Aged↗

PubMed2000

Influence of diet and occlusal support on learning memory in rats behavioral and biochemical studies.

In order to verify the relationship between tooth loss and the learning memory in rat, male Wistar rats (25 weeks old) were divided into three separate groups: a control group (fed with a solid diet); a soft diet group (fed with a powder diet containing the same components as the solid one) and a molarless group (all molars were removed at 25 weeks and then fed with a powder diet). To evaluate both learning ability and memory, rats were tested with a one-way step through type of passive avoidance apparatus divided into light and dark chambers at 40-weeks. After the passive avoidance test, determination of acetylcholine (ACh) concentration of the cerebral cortex and hippocampus was performed. There was no significant difference between the molarless group and the control group in the response latency before the acquisition trails (non-stimulated period). At day 4 and 7 after the acquisition trials, the response latency of the molarless group was significantly shorter than that in the control group (p<0.05). The ACh levels of the molarless group in the cerebral cortex and hippocampus were significantly lower than that of the control group (p<0.05). It was apparent that tooth loss had an association with a loss of discriminative learning ability. This study suggested that the decrease of masticatory function caused by tooth loss leads to a decrease of ACh synthesis resulting in a learning memory disorder.

Acetylcholine↗

PubMed2000

Metabolism of ginsenoside Rg1 by intestinal bacteria. II. Immunological activity of ginsenoside Rg1 and Rh1.

AIM: To compare the effect of ginsenoside Rg1 and its metabolite Rh1 on proinflammatory cytokines and their mRNA expression by THP-1 cells. METHODS: Human peripheral blood mononuclear cells (PBMC) were incubated with Rg1 and Rh1 at concentrations of 0.1, 1, 10, and 100 mg/L, and the cell proliferation was measured 24 h after incubation. Radioimmunoassay (RIA) was used to detect the production of proinflammatory cytokines, TNF alpha, IL-1 alpha, and IL-8. TNF alpha mRNA level was detected by reverse transcription polymerase chain reaction (RT-PCR) after administration of Rg1 and Rh1. RESULTS: Rg1 and Rh1 (at concentration of 0.1, 1, 10, 100 mg/L) had no effect on PBMC proliferation. Rh1 1 mg/L could upregulate the productions of TNF (and IL-8 induced by lipopolysaccharides (LPS) 10 mg/L plus phorbol myristate acetate (PMA) 200 nmol/L, however, Rg1 showed an inhibitory effect on TNF alpha production induced by LPS 100 mg/L. Rg1 1 mg/L and Rh1 100 mg/L enhanced the production of IL-1 alpha level in THP-1 cells in the presence of LPS 10 mg/L. RT-PCR revealed that Rh1 stimulated TNF alpha mRNA expression in suitable stimulatory conditions. CONCLUSION: Rg1 and Rh1 have different effects on the production of cytokines produced THP-1 cells stimulated by LPS and PMA.

Ginsenosides↗

PubMed2000

Effects of polysaccharides (FI0-b) from mycelium of Ganoderma tsugae on proinflammatory cytokine production by THP-1 cells and human PBMC (I).

AIM: To compare the effects of water-soluble polysaccharides, FI0-b, and its formic acid-modified derivative, FI0-b-H, on production of human proinflammatory cytokines. METHODS: The polysaccharides were modified by formic acid. Cytokine production was quantitated by radioimmunoassay. mRNA for cytokines was measured by semi-quantitative RT-PCR. RESULTS: FI0-b and FI0-b-H 4, 40, and 400 mg/L significantly downregulated interleukin-1 alpha (IL-1 alpha) production by THP-1 cells induced by lypopolysaccharide (LPS) 1 or 10 mg/L and phorbol myristate acetate (PMA) 200 nmol/L. At lower stimulation with LPS 10 mg/L and PMA 200 nmol/L, both polysaccharides significantly upregulated tumor necrosis factor alpha (TNF alpha) production by THP-1 cells. However, at higher stimulation with LPS 100 mg/L and PMA 200 nmol/L, they downregulated TNF alpha production. FI0-b-H downregulated interleukin-8 (IL-8) production by THP-1 cells at a lower-dose of LPS 1 mg/L and PMA 200 nmol/L, but upregulated IL-8 production at a higher-dose of LPS 10 mg/L and PMA 200 nmol/L. Production of cytokines (IL-1 alpha and TNF alpha) was transcriptionally or post-transcriptionally regulated by FI0-b and FI0-b-H. CONCLUSION: The water-soluble polysaccharides of Ganoderma tsugae mycelium have bidirectional immunomodulatory effects on cytokine production in different stimulatory conditions in a dose-dependent manner. Compared with FI0-b, FI0-b-H has more marked effects on human proinflammatory cytokine production.

Adult↗

PubMed2000

Effects of polysaccharides (FI0-c) from mycelium of Ganoderma tsugae on proinflammatory cytokine production by THP-1 cells and human PBMC (II).

AIM: To study the effects of water-soluble polysaccharides. FI0-c, and its sulfated derivative, FI0-c-S, on production of human proinflammatory cytokines, interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha). METHODS: The herbal polysaccharides were modified by chlorosulfornic acid in dimethyl sulfoxide (Me2SO). Cytokine production was measured by radioimmunoassay, mRNA for the cytokines was measured by semi-quantitative RT-PCR. RESULTS: FI0-c 4 mg/L itself induced IL-1 alpha production by THP-1 cells without stimulants, such as lipopolysaccharides (LPS) and phorbol myristate acetate (PMA). On the other hand, FI0-c and FI0-c-S inhibited the IL-1 alpha production by THP-1 cells with these stimulants. FI0-c and FI0-c-S significantly upregulated TNF alpha production by THP-1 cells without stimulants or at a low dose of LPS 10 mg/L and PMA 200 nmol/L, whereas these polysaccharides markedly downregulated the TNF alpha production by a high dose of LPS 100 mg/L and PMA. Human peripheral blood mononuclear cells (PBMC) responded to FI0-c and FI0-c-S in IL-1 alpha and TNF alpha production in a fashion similar to THP-1 cell responses. FI0-c 4 mg/L downregulated high-dose LPS- and PMA-induced IL-1 alpha or TNF alpha mRNA and their protein production by THP-1 cells. CONCLUSION: The water-soluble polysaccharides of Ganoderma tsugae mycelium have bidirectional immunomodulatory effects on cytokine production in different cell stimulatory conditions. Chemical modification of this polysaccharide changed the intensity of regulatory effect on cytokine production.

Adult↗

PubMed2000

Pharmacological aspects of ipecac syrup (TJN-119)-induced emesis in ferrets.

In order to elucidate the precise mechanism of ipecac syrup (TJN-119) on the occurrence of vomiting, we examined the effects of ipecac syrup on the abdominal afferent nerve activity as well as on the 5-HT levels of the ileum and area postrema in ferrets. Oral administration of TJN-119 (0.5 mg/kg) produced a significant increase in afferent abdominal vagus nerve activity which lasted approximately 1 hour. The maximum response induced by TJN-119 was estimated to be 219 +/- 18% of the pre-injection level. Cephaeline or emetine, the main alkaloids of ipecac syrup, also demonstrated similar effects on afferent vagus nerve activity. TJN-119 increased the 5-HT content in the ileum but not in the area postrema. These observations illustrate possible mechanisms that may act at peripheral sites. It was recently reported that TJN-119 has a high affinity to 5-HT4 receptors (Hasegawa et al., unpublished data). These results suggest that 5-HT4 receptors may be involved in the emetic action of TJN-119.

Afferent Pathways↗