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Biomedical subjects

Y Miwa

Publications and source records attributed to Y Miwa.

At least 19 recordsLinked to original sources
PubMed2006

Acetylcholinesterase inhibitor acting on the brain improves detrusor overactivity caused by cerebral infarction in rats.

PURPOSE: The functional contribution of the cholinergic pathway in the frontal cortex to micturition was evaluated following cerebral ischemia. Furthermore, it was examined whether reactivation of this regulatory system using acetylcholinesterase inhibitor could improve detrusor overactivity. METHODS: Left middle cerebral artery occlusion (MCAO) was performed in female Sprague-Dawley rats. Choline acetyltransferase (ChAT) activities after MCAO were assayed to assess the damage to cholinergic neurons. ChAT activities in the bilateral cortex, hippocampus, and pons were calculated by measuring the conversion of 1-[14C] acetyl-coenzyme A to [14C] acetylcholine. Effects on cystometrography of i.v. or i.c.v. donepezil hydrochloride (DON), a centrally acting acetylcholinesterase inhibitor, were investigated in conscious sham-operated (SO) and cerebral infarcted (CI) rats. To investigate whether DON in the forebrain was affected, we decerebrated rats after CI or SO, and investigated the effects on cystometrography of i.v. DON. RESULTS: Bladder capacity was markedly decreased after MCAO, and remained below half of the pre-occlusion capacity. The greatest increase in bladder capacity was attained at 1.2 x 10(-2) nM/kg of DON given i.v., with a change of 52.8% (P < 0.05). In cases of i.c.v. DON, the greatest increase in bladder capacity was at the dose of 6 x 10(-2) pmol with the change of 95.8% (P < 0.01). The activity of ChAT was decreased in the left cortex and hippocampus 24 h after MCAO (P < 0.05). In decerebrated rats, low dose of DON did not change micturition parameters. CONCLUSIONS: These results suggest that by upregulation of the forebrain muscarinic inhibitory mechanism, acetylcholinesterase inhibitor improves detrusor overactivity by cerebral infarction.

Analysis of Variance↗
PubMed2006

Apocrine adenocarcinoma of possible sweat gland origin in a male rabbit.

A five-year-old, male crossbreed rabbit was referred for acute caudal abdominal swelling. On physical examination, the rabbit was slightly depressed and showed an enlarged subcutaneous cyst in the caudal abdomen and an adjacent small, ulcerated solid mass. A drainage tube was placed in the cystic area, and surgical resection of the solid mass was performed. The histopathological diagnosis of the mass was apocrine adenocarcinoma. To the authors' knowledge, this report describes the first case of spontaneous apocrine adenocarcinoma of possible sweat gland origin in a male rabbit.

Adenocarcinoma↗
PubMed2005

Are anemic patients more sensitive to calcineurin inhibitors?

A calcineurin inhibitor (CNI) is characterized by high affinity binding to red blood cells. There is a possibility that hematocrit levels might affect the immunosuppressive effects of cyclosporine (CsA). The purpose of this study was to examine whether the treatment with CNI was more effective in preventing acute rejection in anemic compared with nonanemic patients and to find a suitable method to monitoring immunosuppression. Ninety-five living donor renal transplant recipients who were treated with CsA were divided into five groups depending on their Ht levels. The incidences of biopsy-proven acute rejection were 1/8 (12.5%), 8/31 (25.8%), 6/28 (21.4%), 10/22 (45.5%), and 2/6 (33.3%) for Ht < or = 25%, 25% < Ht < or = 30%, 30% < Ht < or = 35%, 35% < Ht < or = 40%, and 40% < Ht, respectively. In vitro IL-2 mRNA inhibition tests were performed to evaluate lymphocyte function after stimulation of whole-blood with phorbol myristate acetate and Ca-ionophore in the presence of various concentrations of CsA. Whole blood CsA levels causing 50% inhibition of IL-2 mRNA (IC50) were 256, 310, 175, and 55 ng/mL for Ht 50%, 40%, 30%, and 20%, respectively. It is speculated that plasma concentrations of CsA may increase at low Ht levels, because lower incidences of acute rejection and lower IC50 values of CsA were observed in the anemic state. When the dosage of CsA was adjusted to its whole-blood concentration, the anemic state is likely to enhance the immunosuppressive effect of CsA. A pharmacodynamic study, such as the IL-2 mRNA inhibition test, is preferable for CsA monitoring.

Anemia↗
PubMed2004

Diagnostic value of carotid intima-media thickness and plaque score for predicting target organ damage in patients with essential hypertension.

Carotid intima-media thickness (IMT) assessed by ultrasonography is regarded as an early predictor of general arteriosclerosis in patients with essential hypertension. However, the methods of measuring IMT have not been globally standardized, and it remains unclear whether conventional measurement of IMT represents the prevalence of hypertensive target organ damage. In this study, we verified the association between several commonly used carotid ultrasonographical parameters and the severity of hypertensive target organ damage (retinal arteriosclerosis, microalbuminuria, left ventricular hypertrophy (LVH)). Carotid ultrasonography, echocardiography, urinalysis, and funduscopy were performed in 184 patients (64 +/- 12 years, 96 males and 88 females) with various stages of essential hypertension. Carotid arteriosclerosis was assessed using four methodologically different methods: conventional-IMT, maximum-IMT (Max-IMT), Mean-IMT, and Plaque Score (the sum of all plaque thicknesses). Age and all carotid ultrasonographical parameters were significantly associated with albuminuria, retinal arteriosclerosis, and left ventricular mass index. High-sensitivity CRP was significantly correlated with retinopathy and LVH. Carotid parameters in patients with histories of cardiovascular events were significantly greater in those without events. Among all carotid parameters, Max-IMT showed the highest correlation coefficient of the severity of target organ damage, and showed significant association with CRP. Stepwise regression analysis revealed that Max-IMT was the independent factor for predicting target organ damage. Max-IMT is suggested to be the most reliable and simplest parameter for predicting hypertensive target organ damage including microangiopathy in patients with essential hypertension.

Albuminuria↗
PubMed2003

Purification and partial characterization of a dipeptidyl peptidase from Prevotella intermedia.

A peptidase hydrolyzed X-Pro-p-nitroanilide was purified from the cell extract of Prevotella intermedia ATCC 25611 by ion-exchange chromatography and hydrophobic interaction chromatography. The purified enzyme exhibited a molecular size of 74 kDa from sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the maximum enzyme activity was found between pH 7.0 and pH 7.5. This peptidase was a serine enzyme and hydrolyzed Lys-Pro-p-nitroanilide, Arg-Pro-p-nitroanilide, and Ala-Pro-p-nitroanilide, but Lys-Ala-p-nitroanilide was not split. The enzyme may be classified as a dipeptidyl peptidase IV.

Amino Acid Sequence↗
PubMed2001

Stereospecific 1,3-migration of an Fe(CO)3 group on acyclic conjugated polyenes: application to remote and iterative asymmetric induction.

The stereochemical outcome of the 1,3- and 1,5-migration of an Fe(CO)3 group on (acyclic polyene)Fe(CO)3 complexes and their application to stereoselective construction of remote and contiguous stereogenic centers are described. Treatment of the [(eta(4)-4-7)triene]Fe(CO)3 complexes 1a-d bearing an electron-withdrawing group on the terminal position of an uncomplexed olefin with a base such as KN(SiMe3)2 (KHMDS) and LiCH2CN induced the 1,3-migration reaction of the Fe(CO)3 group, giving the [(eta4-2-5)triene]Fe(CO)3 complexes 2a-d in moderate to good yields, depending on the electron-withdrawing groups. From an experiment using the chiral (trienenitril)Fe(CO)3 complex 5, it is revealed that the 1,3-migration proceeds with inversion of configuration. Similarly, the 1,5-migration reaction of the[(eta4-6-9)tetraenone]Fe(CO)3 complexes 9 occurred with a catalytic amount of KHMDS, giving the [(eta4-2-5)tetraenone]Fe(CO)3 complexes 10 with retention of configuration. Furthermore, we have succeeded in the first regio- and stereoselective nucleophilic substitution of the (3,5-diene-1,2-diol) Fe(CO)3 complexes (15 --> 24a-h) with various nucleophiles via the ortho esters 21. By using iterative manipulation of the above two reactions, remote stereocontrol of the terminal substituents on acyclic polyene (9 --> 12) and construction of contiguous stereogenic centers (19, 28) have been achieved.

Journal Article↗
PubMed2001

Serotonin-induced hypercontraction through 5-hydroxytryptamine 1B receptors in atherosclerotic rabbit coronary arteries.

BACKGROUND: Augmented vasoconstriction to serotonin (5-hydroxytryptamine [5-HT]) in atherosclerotic vessels plays a crucial role in the development of myocardial ischemia. We investigated mechanisms for serotonin-evoked hypercontraction in atherosclerotic rabbit coronary arteries. METHODS AND RESULTS: Contractile responses to serotonergic agents of endothelium-denuded coronary arteries from control and Watanabe heritable hyperlipidemic rabbits (WHHL) were examined. WHHL coronary arteries exhibited hypercontraction to 5-HT(1)-receptor agonists; the constrictor threshold concentrations and E:D(50) to serotonin, 5-carboxamidotryptamine, and sumatriptan in WHHL were significantly lower, and the E:(max) in WHHL to these agents were increased 55% to 59% above those of the control. Serotonin-evoked contractions in both groups were inhibited by GR127935 (5-HT(1B/1D) antagonist; 0.1 to 1 nmol/L) and pertussis toxin but not by ketanserin (5-HT(2) antagonist; 0.01 to 1 micromol/L), suggesting that the hypercontraction is most likely mediated by 5-HT(1B/1D) receptors through a pertussis toxin-sensitive pathway. Furthermore, simultaneous measurements of [Ca(2+)](i) and isometric tension of fura-2-loaded arteries revealed that the hypercontraction was concomitant with the augmented elevation of [Ca(2+)](i) in the smooth muscle. The 5-HT(1B) mRNA levels in WHHL coronary arteries increased to 2.5-fold over those in control arteries, whereas neither 5-HT(1D) nor 5-HT(2A) mRNA was detected in either group. CONCLUSIONS: Atherosclerotic rabbit coronary arteries exhibited the enhancement in contraction and Ca(2+) mobilization in response to serotonin. The 5-HT(1B) receptor, which is upregulated by atherosclerosis, most likely mediates the augmenting effects of serotonin.

Animals↗
PubMed2001

Combined transcriptome and proteome analysis as a powerful approach to study genes under glucose repression in Bacillus subtilis.

We used 2D protein gel electrophoresis and DNA microarray technologies to systematically analyze genes under glucose repression in B:acillus subtilis. In particular, we focused on genes expressed after the shift from glycolytic to gluconeogenic at the middle logarithmic phase of growth in a nutrient sporulation medium, which remained repressed by the addition of glucose. We also examined whether or not glucose repression of these genes was mediated by CcpA, the catabolite control protein of this bacterium. The wild-type and ccpA1 cells were grown with and without glucose, and their proteomes and transcriptomes were compared. 2D gel electrophoresis allowed us to identify 11 proteins, the synthesis of which was under glucose repression. Of these proteins, the synthesis of four (IolA, I, S and PckA) was under CcpA-independent control. Microarray analysis enabled us to detect 66 glucose-repressive genes, 22 of which (glmS, acoA, C, yisS, speD, gapB, pckA, yvdR, yxeF, iolA, B, C, D, E, F, G, H, I, J, R, S and yxbF ) were at least partially under CcpA-independent control. Furthermore, we found that CcpA and IolR, a repressor of the iol divergon, were involved in the glucose repression of the synthesis of inositol dehydrogenase encoded by iolG included in the above list. The CcpA-independent glucose repression of the iol genes appeared to be explained by inducer exclusion.

Amino Acid Sequence↗
PubMed2001

Pelvic venoablation with ethanol for the treatment of erectile dysfunction due to veno-occlusive dysfunction.

OBJECTIVES: To perform pelvic venoablation with ethanol injection into the deep dorsal vein for the treatment of 10 patients with venogenic erectile dysfunction. This procedure was easily performed without any selective embolization technique. The efficacy and safety of this technique are discussed. METHODS: A total of 10 patients with veno-occlusive dysfunction, severe enough to make vaginal insertion impossible, underwent pelvic venoablation with ethanol. The mean patient age was 67.1 years. Under spinal anesthesia, after the venous leaks were identified by cavernosography, a 20-gauge flexible needle was inserted into the deep dorsal vein. The pelvic venogram obtained with deep dorsal venography was included in what was revealed by the venogram obtained with cavernosography. A mixture of absolute ethanol and contrast medium (4:1) was used as a sclerosing agent. Under fluoroscopic control, the sclerosing agents were injected into the deep dorsal vein through a flexible needle. Success was defined as the ability to achieve vaginal insertion without the aid of any drugs, vasoactive injections, penile prosthesis, or vacuum device. RESULTS: The follow-up ranged from 25 to 37 months (mean 32.3). At the short-term follow-up visit (less than 6 months), 7 patients (70%) reported erections sufficient for vaginal insertion; at the long-term follow-up visit, 5 men (50%) reported sustained, sufficient potency and 5 (50%) reported persistent erectile dysfunction. No serious complications occurred. CONCLUSIONS: Our pelvic venoablation technique using ethanol was effective, minimally invasive, and cost-effective.

Aged↗
PubMed2001

Sesquiterpene glucosides from anti-leukotriene B4 release fraction of Taraxacum officinale.

Chemical examination of the MeOH extract of the root of Taraxacum officinale, which exhibited inhibitory activity on the formation of leukotriene B4 from activated human neutrophils, has resulted in the isolation of 14-O-beta-D-glucosyl-11,13-dihydro-taraxinic acid (1) and 14-O-beta-D-glucosyl-taraxinic acid (2). The absolute stereostructure of 1 has been established by X-ray chrystallographic examination.

Anti-HIV Agents↗
PubMed2001

Involvement of two distinct catabolite-responsive elements in catabolite repression of the Bacillus subtilis myo-inositol (iol) operon.

The Bacillus subtilis inositol operon (iolABCDEFGHIJ) is involved in myo-inositol catabolism. Glucose repression of the iol operon induced by inositol is exerted through catabolite repression mediated by CcpA and the iol induction system mediated by IolR. In this study, we identified two iol catabolite-responsive elements (cre's), to which CcpA complexed with P-Ser-HPr or P-Ser-Crh probably binds. One is located in iolB (cre-iolB, nucleotides +2397 to +2411; +1 is the transcription initiation nucleotide), which was the only cre-iol found in the previous cre search of the B. subtilis genome using a query sequence of WTGNAANCGNWNNCW (W stands for A or T, and N stands for any base). Deletion and base substitution analysis of the iol region indicated that cre-iolB functions even if it is located far downstream of the iol promoter. Further deletion and base substitution analysis revealed another cre located between the iol promoter and the iolA gene (cre-iiolA, nucleotides +86 to +100); the prefix "i" indicates a location in the intergenic region. Both cre-iiolA and cre-iolB appeared to be recognized to almost the same extent by CcpA complexed with either P-Ser-HPr or P-Ser-Crh. Sequence alignment of the six known cre's, including cre-iiolA, which were not revealed in the previous cre search, exhibited another consensus sequence of WTGAAARCGYTTWWN (R stands for A or G, and Y stands for C or T); the right two thymines (TT) were found to be essential for the function of cre-iiolA by means of base substitution analysis. A cre search with this query sequence led to the finding of 14 additional putative cre's.

Bacillus subtilis↗
PubMed2000

Nuclear translocation of TSC-22 (TGF-beta-stimulated clone-22) concomitant with apoptosis: TSC-22 as a putative transcriptional regulator.

We examined the alteration of the subcellular localization of TSC-22 (TGF-beta-stimulated clone-22) after induction of apoptosis and the transcription-regulatory activity of TSC-22. In the living cells, TSC-22-green fluorescent protein (GFP) fusion protein was clearly localized to the cytoplasm, however, in the apoptotic cells, the TSC-22-GFP fusion protein was translocated from the cytoplasm to the nucleus. TSC-22 fused to GAL4-DNA binding domain (GAL4BD) did not show the transcriptional activity on the reporter genes in yeast and in HSG (salivary gland cancer cells) and Hela. However, in CHO cells, TSC-22-GAL4BD fusion protein strongly activated the reporter gene. The transcriptional activity of the leucine zipper structure of TSC-22 is greater than that of the full-length TSC-22. These findings suggest that after receiving the apoptotic stimuli, TSC-22 translocates from the cytoplasm to the nucleus and shows the transcription-regulatory activity.

Animals↗
PubMed2000

Fluid shear stress induces lipocalin-type prostaglandin D(2) synthase expression in vascular endothelial cells.

Ligands for peroxisome proliferator-activated receptor gamma, such as the thiazolidinedione class of antidiabetic drugs and 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), modulate various processes in atherogenesis. In search of cells that generate prostaglandin D(2) (PGD(2)), the metabolic precursor of 15d-PGJ(2), we identified PGD(2) from culture medium of endothelial cells. To study how PGD(2) production is regulated in endothelial cells, we investigated the role of fluid shear stress in the metabolism of PGD(2). Endothelial cells expressed the mRNA for the lipocalin-type PGD(2) synthase (L-PGDS) both in vitro and in vivo. Loading laminar shear stress using a parallel-plate flow chamber markedly enhanced the gene expression of L-PGDS, with the maximal effect being obtained at 15 to 30 dyne/cm(2). The expression began to increase within 6 hours after loading shear stress and reached the maximal level at 18 to 24 hours. In contrast, shear stress did not alter the expression levels of PGI(2) synthase and thromboxane A(2) synthase. In parallel with the increase in the expression level of L-PGDS, endothelial cells released PGD(2) and 15d-PGJ(2) into culture medium. These results demonstrate that shear stress promotes PGD(2) production by stimulating L-PGDS expression and suggest the possibility that a peroxisome proliferator-activated receptor gamma ligand is produced in vascular wall in response to blood flow.

Arteries↗
PubMed2000

Orexin-induced food intake involves neuropeptide Y pathway.

Orexins (orexin-A and -B) are recently identified neuropeptides, which are thought to be implicated in the regulation of feeding behavior. We used a NPY-Y1 receptor specific antagonist, BIBO3304, to examine whether NPY is involved in orexin-induced feeding behavior. Intracerebroventricular administration of orexin-A (10 nmol) induced food intake in rats (food intake for 3 h; vehicle 0.3+/-0.2 g vs. orexin-A 10 nmol, 4.0+/-0.5 g, n=4). Orexin-induced feeding behavior was partially inhibited by prior administration of BIBO3304 (3 h food intake: orexin-A 10 nmol, 4.0+/-0.5 g vs. BIBO3304 (60 microgram) + orexin-A 10 nmol, 2.2+/-0.2 g, n=4). A low dose of BIBO3304 (30 microgram) did not show a significant inhibitory effect. BIBO3457, an inactive enantiomer, used as a negative control, did not show any inhibitory effect on orexin-A-induced feeding behavior. Fos expression was observed in NPY-containing neurons in the arcuate nucleus 1 h after orexin-A (10 nmol) was administered intracerebroventricularly (control 0.3+/-0.08%, orexin-A 10.2+/-0.8%, n=5 rats/group). These observations suggest that NPY is involved in orexin-induced feeding behavior. However, BIBO3304 did not completely abolish the effect of orexin-A. These results suggest that orexin-A elicits feeding behavior partially via the NPY pathway. The NPY system could be the one of downstream pathways by which orexin-A induces feeding behavior. Another pathway may also be involved in orexin-A-induced feeding behavior, because BIBO3304 did not completely abolish orexin-A-induced feeding behavior.

Animals↗
PubMed2000

Evaluation and characterization of catabolite-responsive elements (cre) of Bacillus subtilis.

A global mechanism of catabolite repression of the genus Bacillus comprises negative regulation exerted through the binding of the CcpA protein to the catabolite-responsive elements (cres) of the target genes. We searched for cre sequences in the Bacillus subtilis genome using a query sequence, WTGNAANCGNWNNCW (N and W stand for any base and A or T, respectively), picking out 126 putative and known cre sequences. To examine their cre function, we integrated spac promoter (P spac )-cre-lacZ fusions into the amyE locus. Examination of catabolite repression of beta-galactosidase synthesis in the integrants led us to the following conclusions: (i) lower mismatching of cre sequences to the query sequence is required for their function; (ii) although cre sequences are partially palindromic, low mismatching in the same direction as that of transcription of the target genes is more critical for their function than that in the inverse direction; and (iii) yet, a more palindromic nature of cre sequences is desirable for a better function. Furthermore, the alignment of 22 cre s that function in vivo implicated a consensus sequence, WWTGNAARCGNWWWCAWW (R stands for G or A). Interestingly, in the case where cre sequences are located in the protein-coding regions of the target genes, their conserved bases are preferentially the third bases of codons where base degeneracy is allowed.

Amino Acid Sequence↗