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Biomedical subjects

T Kamiya

Publications and source records attributed to T Kamiya.

At least 37 records · Page 2Linked to original sources

KF19418, a new compound for hair growth promotion in vitro and in vivo mouse models.

KF19418, a newly synthesized compound, stimulated proliferation of cultured hair bulb cells from new born mice in concentration-dependent manner in the range under 10 microM. In the culture system of whole skin pieces from 4-week-old mice which we earlier established, KF19418 promoted hair follicle elongation as in the case of minoxidil. After topical application for 2 weeks of KF19418 or minoxidil to dorsal skin of hair-clipped mouse alopecia model, KF19418 at 1% suspension accelerated hair regrowth at a rate comparable to 1% minoxidil solution. Thus, it was shown that KF19418 directly stimulated hair follicle in vitro and had hair growth promoting activities in vivo.

Alopecia↗

Topical application of cyclosporin A induces rapid-remodeling of damaged anagen hair follicles produced in cyclophosphamide administered mice.

Adult C3H mice which had either anagen IV or anagen VI hair follicles were given the anti-tumor drug cyclophosphamide, and cyclosporin A or minoxidil were topically applied to the mice daily from the 4th day after cyclophosphamide administration. In the mice that had anagen IV-hair follicles, 0.5% cyclosporin A induced very thick and long hairs after 21 days of cyclophosphamide administration, while vehicle and 1% minoxidil induced sparsely visible, short hairs. In the mice which received cyclosporin A, the injured hair follicles seemed to remodel themselves into intact anagen hair follicles and restart the production of hairs, instead of shifting to telogen. In the mice that had anagen VI-hair follicles at the time of cyclophosphamide administration, complete alopecia occurred within the first 7 days in all groups. After 14 days of cyclophosphamide administration, hair regrowth was observed in both the 0.5% cyclosporin A-group and the 1% minoxidil- group with the predominant effect over the vehicle. This study shows that anagen hair follicles respond to cyclophosphamide in different ways depending on their stages (IV and VI), and that the damaged anagen IV hair follicles have the potential of remodeling themselves, which is promoted by topical cyclosporin A administration.

Administration, Topical↗

Isolated noncompaction of the ventricular myocardium: ultrafast computed tomography and magnetic resonance imaging.

This study was undertaken to evaluate the feasibility of ultrafast computed tomography (CT) and magnetic resonance imaging (MRI) for anatomical and pathophysiological diagnosis of isolated noncompaction of the left ventricular myocardium (INVM) compared with other imaging modalities including thallium myocardial imaging. Six patients, three sets of siblings, ranging in age from 13 to 18 years, were included in this study. Two-dimensional echocardiograms revealed numerous prominent trabeculations and deep intertrabecular recesses in one or more ventricular wall segments in all cases. Thallium-201 myocardial imaging disclosed a hypoperfusion area corresponding to the zones where noncompacted ventricular myocardium was localized. Ultrafast CT showed early defects of varying degrees and rate enhancement of the noncompacted ventricular myocardium, implying fibrosis in this area. MRI disclosed inner zones of noncompacted myocardium distinguishable from thin outer zones of compacted myocardium. T2-weighted imaging revealed high intensity areas at the apex of the left ventricle, suggesting disturbed microcirculation due to fibrosis, thrombus formation, and hypokinesis. Cine MRI revealed hypokinesis of the noncompacted ventricular wall during the cardiac cycle. In conclusion, ultrafast CT and MRI provide high-resolution imaging of noncompacted myocardium, and also pathophysiological details regarding this rare disease.

Adolescent↗

Role of the epithelium in opposing H(2)O(2)-induced modulation of acetylcholine-induced contractions in rabbit intrapulmonary bronchiole.

1. The role played by the epithelium in H(2)O(2)-induced modulation of the mechanical responses induced by acetylcholine (ACh) in rabbit intrapulmonary bronchioles was investigated in epithelium-intact and -denuded strips. 2. When ACh (3 microM) was applied intermittently, H(2)O(2) (30 microM) enhanced the ACh-induced contractions in epithelium-intact strips. In contrast, in epithelium-denuded strips H(2)O(2) (30 microM) inhibited such contractions. At higher concentrations, H(2)O(2) concentration-dependently attenuated the ACh-induced contractions in both epithelium-intact and -denuded strips, its action being more potent in the latter strips than in the former. 3. Diclofenac (a cyclo-oxygenase inhibitor; 3 microM) reduced the H(2)O(2)-induced enhancement of ACh-contractions in epithelium-intact strips but had no effect on the H(2)O(2)-induced inhibition in epithelium-denuded strips. N(G)-nitro-L-arginine did not alter the effect of H(2)O(2) on ACh-induced contractions in epithelium-intact strips. 4. Catalase (500 u ml(-1)) completely blocked both H(2)O(2)-induced effects on ACh-contractions (enhancement and inhibition). Neither superoxide dismutase (200 u ml(-1)) nor deferoxamine (0.5 mM) had any effect on H(2)O(2)-induced inhibition in epithelium-denuded strips. 5. Aminotriazole (an inhibitor of catalase; 50 mM) significantly potentiated the H(2)O(2)-induced inhibition of ACh-contractions in epithelium-intact strips but not in epithelium-denuded strips. 6. The density ratio for catalase (epithelium-intact over -denuded strips) analysed by Western blot was about 2.1, suggesting that epithelium contains more catalase than smooth muscle. 7. It is concluded that in rabbit intrapulmonary bronchioles, H(2)O(2) has dual actions on ACh-contractions. It is suggested that the epithelium may act as a powerful biochemical barrier via both the action of catalase (scavenging H(2)O(2)) and the release of bronchoconstrictor prostaglandins, thus attenuating the H(2)O(2)-induced modulation of ACh-contractions.

Acetylcholine↗

Presence of Propionibacterium acnes in blood components.

BACKGROUND: Sterility testing, as part of the QC of blood components at the Japanese Red Cross Aichi Blood Center between April 1998 and March 2000, showed that 10 of 5568 tested blood components (0.18%), all of which were RBC concentrates, were contaminated with bacteria. Nine isolates were Propionibacterium acnes and one was Staphylococcus capitis. STUDY DESIGN AND METHODS: To investigate the molecular relatedness of eight available P. acnes isolates, 16S rRNA gene analysis and random amplified polymorphic DNA (RAPD) analysis were performed. RESULTS: DNA sequencing analysis of the 16S rRNA gene showed that five isolates were identified as distinct strains and that three had identical sequences. RAPD analysis in the latter three isolates showed that two exhibited indistinguishable banding patterns that differed from that of the third isolate. CONCLUSION: P. acnes was the most frequent contaminant of blood components, and six of eight isolates were molecularly unrelated. Further studies are necessary to investigate the precise mechanisms of contamination.

Erythrocytes↗

The positive inotropic and chronotropic effects of evodiamine and rutaecarpine, indoloquinazoline alkaloids isolated from the fruits of Evodia rutaecarpa, on the guinea-pig isolated right atria: possible involvement of vanilloid receptors.

Cardiotonic effects of evodiamine and rutaecarpine, constituents of the fruits of Evodia rutaecarpa Bentham Rutaceae, were evaluated on guinea pig isolated atria. Comparison with capsaicin, a vanilloid receptor agonist, revealed similar positive inotropic and chronotropic activity, as judged from antagonistic effects of the competitive vanilloid receptor (capsaicin receptor) antagonist capsazepine, the non-competitive vanilloid receptor antagonist ruthenium red, the calcitonin gene related peptide antagonist CGRP(8-37), the P2X purinoceptor antagonist PPADS, and various desensitization studies. Evodiamine and rutaecarpine produced transient positive inotropic and chronotropic effects on the guinea-pig isolated atria, followed by a desensitizing effect to additional administration. Dose-response relationships for evodiamine, rutaecarpine and capsaicin were obtained. All the compounds evoked positive inotropic and chronotropic effects in a concentration-dependent manner. Maximal contractions for evodiamine, rutaecarpine and capsaicin were observed at concentrations of 1 microM, 3 microM and 0.3 microM, respectively. The cardiotonic responses evoked by both evodiamine and rutaecarpine were shifted to the right by capsazepine, an established antagonist of vanilloid receptor (capsaicin-receptor). The effects of both evodiamine (1 microM) and rutaecarpine (3 microM) were abolished by pretreatment with a desensitizing dosage of capsaicin (1 microM), developing cross-tachyphylaxis between these compounds. The effects of evodiamine (1 microM), rutaecarpine (3 microM) and capsaicin (0.3 microM) were also significantly reduced by pretreatment with ruthenium red (10 microM) and CGRP (8-37) (10 microM). The effects of evodiamine, rutaecarpine and capsaicin were not affected by pretreatment with PPADS (100 microM), a highly selective P2X purinoceptor antagonist, and the possibility of the involvement of the P2X purinoceptor was excluded. These results suggest that the positive inotropic and chronotropic effects on the guinea-pig isolated right atria induced by both evodiamine and rutaecarpine could be attributed to their interaction with vanilloid receptors and the resultant release of CGRP, a cardiotonic neurotransmitter, from capsaicin-sensitive nerves as with capsaicin.

Alkaloids↗

Capsaicin-like anti-obese activities of evodiamine from fruits of Evodia rutaecarpa, a vanilloid receptor agonist.

Evodiamine, a major alkaloidal principle of Evodia fruits (Evodia rutaecarpa, Rutaceae), showed vanilloid receptor agonistic activities comparable to capsaicin. The Chinese literature refers to Evodia fruits as a "hot nature" herb. In spite of the similarities in the actions of evodiamine and capsaicin in vitro, evodiamine has no perceptible taste, including a peppery hot taste. Therefore, the effectiveness of evodiamine and the extract of Evodia fruits in preventing obesity on male C3H mice, or male SD rats were examined. When evodiamine was supplemented at 0.03% of the diet and fed to mice for 12 days, the perirenal fat weight became significantly lower than in the control group. The epididymal fat mass was also decreased in the evodiamine diet group. When evodiamine was supplemented at 0.02% in the form of ethanol extract of Evodia fruits to the high-fat diet and fed to rats for 21 days, the body weight, the perirenal fat weight, epididymal fat weight, the levels of serum free fatty acid, total lipids in the liver, triglyceride in the liver, and cholesterol level in the liver were significantly reduced as compared with the control diet group. Furthermore, both lipolytic activity in the perirenal fat tissue and specific GDP binding in brown adipose tissue mitochondria, as the biological index of enhanced heat production, were significantly increased in the evodiamine fed rats. Fasting mice subcutaneously administered 1-3 mg/kg evodiamine showed decreased core body temperature by 1-2 degrees C. This hypothermic effect was prevented by the pretreatment of intraperitoneally administered 10 mg/kg capsazepine, a vanilloid receptor antagonist. On the other hand, food-sated mice subcutaneously administered 1-3 mg/kg evodiamine showed unchanged core body temperature and increased tail skin temperature by more than 5 degrees C, suggesting the increased energy expenditure by enhanced heat dissipation. In conclusion, we have demonstrated that a novel non-pungent vanilloid receptor agonist, evodiamine, mimics the characteristic anti-obese effects induced by capsaicin. Evodiamine would induce heat loss and heat production at the same time and dissipate food energy, preventing the accumulation of perivisceral fat and the body weight increase.

Adipose Tissue↗

The progression of aging in klotho mutant mice can be modified by dietary phosphorus and zinc.

Reduction in klotho gene expression causes accelerated senescence in klotho mutant mice. We have now found two key substances, phosphorus and zinc, which affect the appearance of klotho phenotypes. Klotho mutant homozygotes fed nonpurified diet with a phosphorus concentration of 1.03 g/100 g showed typical klotho phenotypes. However, most of the klotho phenotypes no longer appeared in male homozygotes fed a 0.4 g/100 g phosphorus diet. These homozygotes were capable of spermatogenesis. In the kidneys of the rescued male homozygotes, klotho protein expression was clearly detected. On the other hand, female klotho mice required supplementation of 0.25 g/100 g zinc orotate to the 0.4 g/100 g phosphorus diet to be rescued. Unlike in the rescued male mice, klotho protein levels in the kidneys of the rescued females were quite low. Wild-type (C3H/He) mice fed 1.5 or 1.0 g/100 g phosphorus diets had lower klotho protein expression in the kidneys than those fed a 0.4 g/100 g phosphorus diet (Kruskal-Wallis test, P < 0.05). These results indicate that dietary phosphorus and zinc modulate the phenotypes of klotho mice, and that klotho expression in the kidneys is regulated not only in klotho mutant mice, but also in wild-type mice.

Aging↗

Low metacarpal bone density, tooth loss, and periodontal disease in Japanese women.

The relationship between periodontitis and systemic bone mineral density in Japanese women is undetermined. We tested the hypothesis that periodontitis was more frequent in women with low metacarpal bone mineral density (m-BMD). Subjects were 190 Japanese women (89 premenopausal, 101 post-menopausal). Periodontal status was evaluated according to the Community Periodontal Index of Treatment Need (CPITN). M-BMD was measured by computed x-ray densitometry. The proportion of subjects with periodontitis (CPITN > or = 3) increased as m-BMD decreased in pre-menopausal (18.2%, 36.9%, and 66.6% in the normal, borderline, and very low m-BMD groups, p < 0.02) and post-menopausal women (41.5%, 54.8%, 60%, and 68.4% in the normal, borderline, low, and very low m-BMD groups, p < 0.05). Among post-menopausal women, those with very low m-BMD had fewer teeth present than women with normal m-BMD (19.9+/-7.2 vs. 25.1+/-4.1, p < 0.01). These results indicate that m-BMD loss is associated with periodontitis in Japanese women, and with tooth loss after menopause.

Adult↗

Neuroprotective effect of immunosuppressant FK506 in transient focal ischemia in rat: therapeutic time window for FK506 in transient focal ischemia.

Tacrolimus (FK506), an immunosuppressant currently used in clinic, is known to have neuroprotective properties. However, effects in focal ischemia are shown only in a endothelin induced middle cerebral artery (MCA) occlusion model or with filament technique at a relatively high dose. We have previously shown that FK506 had significant protective effects at a low dose of 0.3 mg kg(-1) when administered immediately after ischemia. In this study, we explored the therapeutic time window of FK506 at this low dose, in a transient focal ischemia model using filament technique. Male Sprague-Dawley rats were subjected to 2 h MCA occlusion and subsequent reperfusion. They received FK506 or vehicle (0.3 mg kg(-1)) i.v. at 30, 60 or 120 min after induction of ischemia, and were decapitated 24 h after ischemia. FK506 injected at 30 and 60 min significantly reduced cortical infarction volume (FK506 vs. vehicle; 30 min: 95 +/- 33 mm3 vs. 170 +/- 62 mm3, p < 0.05; 60 min: 93 +/- 45 mm3, vs. 168 +/- 35 mm3, p < 0.05, respectively). FK506 was ineffective when given at 120 min after ischemia. FK506 had no effect on edema formation, nor on the infarct volume in striatum. The therapeutic time window for this low dose of FK506 given i.v. is between 60 and 120 min in this model.

Animals↗

Pyruvate dehydrogenase activity and energy metabolite levels following bilateral common carotid artery occlusion in rat brain.

The influence of chronic cerebral hypoperfusion on cerebral energy metabolism was studied. The bilateral common carotid arteries of Wistar rats were occluded for 0, 2, 7, and 28 days. Cerebral energy metabolism was evaluated by assaying adenosine triphosphate (ATP), phosphocreatine (PCr), and lactate levels and measuring pyruvate dehydrogenase (PDH) activity (each time point, n = 6). Pathological changes were assessed light-microscopically by Klüver-Barrera staining and immunohistochemical labeling for astroglia (each time point, n = 3). There were no changes in ATP and PCr levels or PDH activity; there was slight but significant transient lactate accumulation at 2 days. Myelin pallor and increase in immuno-reactive astroglia were only observed at 28 days. These results indicate that chronic cerebral hypoperfusion induces delayed white matter changes in the corpus callosum of rat brain, but does not affect energy production.

Adenosine Triphosphate↗

Intragastric migration of a pacemaker implanted in the pleural space.

We have encountered a 12-year-old boy with a pacemaker implanted in the left pleural space during early infancy that migrated into the stomach through the diaphragm due to severe scoliosis and occult infection. The intrathoracic implantation of a pacemaker in an infant should be assessed more carefully, taking the volume of the unit into consideration, because of this potentially life-threatening complication.

Child↗

CO sensing and regulation of gene expression by the transcriptional activator CooA.

The transcriptional activator CooA from Rhodospirillum rubrum contains a six-coordinate protoheme that acts as a CO sensor in vivo. CO is a physiological effector of CooA and replaces one of the axial ligands of the ferrous heme to form the CO-bound CooA that is active as the transcriptional activator. Cys75 or His77 is coordinated to the ferric and ferrous hemes in CooA, respectively. The redox-controlled ligand exchange between Cys75 and His77 proceeds during the change in the redox state of the heme. The reduction and oxidation midpoint potentials of CooA have been determined to be -320 and -260 mV, respectively. The properties of a functional chimera derived from CRP and CooA suggest that CooA activates the transcription by a similar mechanism to that for CRP at Class II CRP-dependent promoters. Alanine-scanning mutagenesis has revealed that Arg24 and Arg53 of CooA, which will be concerned with the protein-protein interaction with RNA polymerase, are critical amino acid residues for the transcriptional activator activity of CooA, and that Lys26 and Asp94 modulate the activity of CooA.

Bacterial Proteins↗

Detailed characterization of an anti-factor IX monoclonal antibody that neutralizes the prolonged ox brain prothrombin time of hemophilia B(M) by synthetic peptides.

In a previous study, we prepared a monoclonal antibody (MoAb) to coagulation factor IX (FIX), designated 65-10, which interfered with the activation of FIX by the activated factor XI/Ca(2+) and neutralized the prolonged ox brain prothrombin time of hemophilia B(M) [11,12]. The location of the epitope on the FIX for 65-10 MoAb is (168) Ile-Thr-Gln-Ser-Thr-Gln-Ser-Phe-Asn-Asp-Phe-Thr-Arg-Val-Val(182) [21]. In this paper, we studied in more detail an epitope on FIX using the systematic substitution of different amino acids at each residue of the epitope peptides and the influence of the epitope peptide on the prolonged ox brain prothrombin time of the hemophilia B(M) plasma of 65-10 MoAb. In the replacement set of amino acids, peptides showing low or no reactivity to 65-10 were (175)Phe --> Asp, Glu, Gly, Lys, Arg, Thr, Val, (176)Asn --> Asp, Glu, Phe, Ile, Lys, Leu, Pro, Val, Tyr, (177)Asp --> Cys, Glu, Phe, Ile, Lys, Leu, Met, Pro, Gln, Arg, Ser, Thr, Val, Trp, Tyr, and (178) Phe --> Pro. These results imply that a hydrophobic molecule of (175) Phe, a hydrophilic molecule of (176)Asn, and a negative charge molecule of (177)Asp were important to the epitope. The 65-10 MoAb antibody neutralized the prolonged ox brain prothrombin time of hemophilia B(M) Nagoya 2 ((180)Arg -->Trp) and Kashihara ((181)Val --> Phe) as well as B(M) Kiryu ((313)Val --> Asp) and Niigata ((390)Ala --> Val). This reaction was inhibited by preincubation with a (168) Ile-Thr-Gln-Ser-Thr-Gln-Ser-Phe-Asn-Asp-Phe-Thr-Arg-Val-Val(182) peptide conjugated with bovine serum albumin (BSA). 65-10 MoAb that has been useful in detailing epitopes will be useful for qualitative analysis of hemophilia B(M).

Amino Acid Sequence↗

Clinical implications of interleukin (IL)-10 induced by non-small-cell lung cancer.

BACKGROUND: The type 2 cytokine interleukin (IL)-10 has been reported to inhibit the antitumour activity of the regional immunity against various neoplasms. Certain lung cancers produce IL-10, but the clinical significance of IL-10 expression is not well understood. PATIENTS AND METHODS: We examined IL-10 and IL-10 receptor (IL-10R) mRNA expression in 82 non-small-cell lung cancers (NSCLC) by reverse transcription-polymerase chain reaction (RT-PCR) assay. Immunohistochemistry (IHC) and enzyme immunoassay (EIA) were applied to evaluate the cellular localisation and the serum levels of IL-10. RESULTS: RT-PCR assay revealed IL-10 mRNA expression in 68 (83%) of 82 NSCLC surgical specimens (40 of 50 adenocarcinomas, 22 of 26 squamous cell carcinomas, 5 of 5 large-cell carcinomas, 1 of 1 adenosquamous-cell carcinoma). RT-PCR assay also revealed IL-10R mRNA expression in 79 cases of NSCLC (96.1%). IL-10 expression was confirmed within tumour cells by IHC. EIA showed no significant serum IL-10 elevation in the 12 NSCLC positive for IL-10 mRNA expression (0-2.99 pg/ml). The NSCLC patients with IL-10 production showed significantly poorer prognosis than those without IL-10 production (P < 0.05, Kaplan Meier, log-rank test). CONCLUSIONS: These results suggested that the cytoplasmic IL-10 correlated to clinical prognosis, and that IL-10 expression is a prognostic factor for NSCLC.

Carcinoma, Non-Small-Cell Lung↗

Neurological and neuroradiological progression in hereditary spastic paraplegia with a thin corpus callosum.

We followed-up a Japanese man suffering from hereditary spastic paraplegia with a thin corpus callosum (HSP-TCC) by single photon emission computed tomography (SPECT) using 123IN-isopropyl-piodoamphetamine (123I-IMP) over 4 years (25 to 29 years old). Besides the initial symptoms of lower limb spasticity, mental deterioration slightly progressed and upper limb spasticity and slight cerebellar ataxia were developed, during the period. Cranial magnetic resonance imaging (MRI) revealed an extremely thin corpus callosum and medial frontal atrophy, which remained essentially unchanged during the period. 123I-IMP SPECT demonstrated that cerebral blood flow was decreased in the thalamus and the medial frontal, temporal and parietal cortices at the first examination, and that the thalamus showed further reduction but the other involved regions presented essentially no progression during the follow-up period. This is the first report referring to the longitudinal clinical and neuroradiological changes in HSP-TCC.

Adult↗

The bronchoconstrictive action of evodiamine, an indoloquinazoline alkaloid isolated from the fruits of Evodia rutaecarpa, on guinea-pig isolated bronchus: possible involvement on vanilloid receptors.

Evodiamine, a constituent of Evodiae Fructus (Evodia rutaecarpa Benth., Rutaceae), produced a bronchial contraction that is resistant to atropine and abolished by pretreatment with a mixture of the NK1 and NK2 receptor antagonists. Contractile responses to evodiamine were examined in guinea-pig isolated bronchus and compared with those to capsaicin. Both compounds evoked bronchial contraction in a concentration-dependent manner. Maximal contractions for evodiamine and capsaicin were observed at concentrations of 3 microM and 1 microM, respectively. Capsazepine (10 microM), an established antagonist of vanilloid receptor (capsaicin receptor), competitively inhibited the bronchial contraction evoked by evodiamine, suggesting that evodiamine activated vanilloid receptors. Evodiamine (3 microM) and capsaicin (1 microM) produced complete crossed tachyphylaxis. Both compounds desensitized tissues to subsequent additions of either evodiamine or capsaicin. These results suggest that the evodiamine-induced contractile response of the bronchus could be attributed to the resultant tachykinin release from sensory neurons by binding of evodiamine to vanilloid receptors. Rutaecarpine, which belongs to the same indoloquinazoline-type alkaloid as evodiamine, showed neither bronchoconstrictive, desensitizing effects nor vanilloid antagonistic effects at all the concentrations examined (up to 200 microM).

Animals↗