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T Yoshimura

Publications and source records attributed to T Yoshimura.

At least 217 records · Page 12Linked to original sources
PubMed1998

Determination of the nucleotide sequence of Bombyx mori cytoplasmic polyhedrosis virus segment 9 and its expression in BmN4 cells.

Cloning and sequencing of segment 9 of Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) strains H and I were performed. The segment consisted of 1,186 bp harboring 5' and 3' noncoding regions and an open reading frame from positions 75 to 1037, encoding a protein with 320 amino acids, termed NS5. Comparison of the nucleotide sequences of NS5 for the two strains indicated 37 point differences resulting in only six amino acid replacements. Homology search showed that NS5 has localized similarities to human poliovirus RNA-dependent RNA polymerase and human rotavirus NS26. By Western blot analysis, NS5 was found in BmCPV-infected midgut cells, but not in polyhedra or virus virions, and was mainly detectable in the nucleus in BmCPV-infected BmN4 cells. Immunoblot analysis with anti-NS5 and antipolyhedrin antibodies displayed marked differences in the period of expression of NS5 and polyhedrin: the polyhedrin molecule was first detected 2 or 3 days after infection with BmCPV, whereas the expression of NS5 was initiated within a few hours. In addition, the level of polyhedrin increased as the infection developed, whereas the amount of NS5 remained essentially constant. When segment 9 was expressed with a baculovirus expression system, the resulting NS5 protein possessed the ability to bind to the double-stranded RNA genome. These results suggest that NS5 is expressed in early stages of infection and contributes to regulation of genomic RNA function.

Amino Acid Sequence↗
PubMed1998

Evaluation of Helicobacter pylori vacA genotype in Japanese patients with gastric cancer.

AIM: To examine the vacA genotypes of Helicobacter pylori strains in Japan and to define whether any specific genotype was associated with gastric cancer. METHODS: The allelic variation of vacA gene was studied using a recently introduced polymerase chain reaction based vacA genotyping system. RESULTS: 80 H pylori strains were isolated from gastric biopsies of 40 patients with gastric cancer and 40 control subjects in a Japanese population. All strains were s1/m1 subtype and 79 of 80 strains were classified as s1a subtype. CONCLUSIONS: The recently proposed vacA genotyping system is applicable to Japanese H pylori strains and most strains have the s1a genotype, associated with increased virulence. While the high frequency of s1a/m1 vacA genotype might play a role in the increased incidence of atrophic gastritis and gastric cancer in Japanese subjects, it precludes its use as a predictor of clinical outcome of H pylori infection in Japan.

Adult↗
PubMed1998

Hepatic uptake of hippurate: a multiple-indicator dilution, perfused rat liver study.

The hepatic transport of hippuric acid (HA), a glycine-conjugated metabolite of benzoic acid that exhibits only modest plasma albumin binding (binding association constant of 2.1 x 10(3) M-1), was studied in the single-pass perfused rat liver (12 ml/min), using the multiple indicator dilution (MID) technique. The venous recovery of [3H]HA on portal venous injection of a MID dose containing a mixture of a set of noneliminated reference indicators and [3H]HA revealed a survival fraction of unity, corroborating the lack of disappearance of bulk HA from plasma. When the outflow recovery was fitted to the barrier-limited model of Goresky et al. (C.A. Goresky, G. G. Bach, and B. E. Nadeau. J. Clin. Invest. 52: 991-1009, 1973), the derived influx (P(in)S) and efflux (P(out)S) permeability-surface area products were found to be dependent on the concentration of HA (1-930 microM); P(in)S and P(out)S were approximately 3.5 times the plasma flow rate at low HA concentration, but decreased with increasing HA concentration. All values, however, greatly exceeded the expected contribution from passive diffusion, because the equilibrium distribution ratio of chloroform to buffer for HA was extremely low (0.0001 at pH 7.4). The tissue equilibrium partition coefficient (P(in)/P(out), or ratio of influx to efflux rate constants, k1/k-1) was less than unity and decreased with concentration. The optimized apparent Michaelis-Menten constant and maximal velocity were 182 +/- 60 microM and 12 +/- 4 nmol.s-1.g-1, respectively, for influx and 390 +/- 190 microM and 29 +/- 13 nmol.s-1.g-1, respectively, for efflux. In the presence of L-lactate (20 mM), however, P(in)S for the uptake of HA (174 +/- 3 microM) was reduced. Benzoic acid (10-873 microM) was also effective in reducing hepatic uptake of HA (5.3 +/- 0.9 microM). These interactions suggest that MCT2, the monocarboxylate transporter that mediates the hepatic uptake of lactate and other monocarboxylic acids, may be involved in HA transport.

Animals↗
PubMed1998

In vivo three-dimensional EPR imaging of nitric oxide production from isosorbide dinitrate in mice.

Recently, in vivo electron paramagnetic resonance (EPR) spectroscopy and imaging have been widely used to investigate free radical distribution and metabolism in tissues, organs, and whole body of small animals. Endogenous nitric oxide (NO) is an attractive target of this method. In the present study, NO production from a nitrovasodilator, isosorbide dinitrate (ISDN), in live mice was investigated by in vivo EPR spectroscopy and imaging combined with the spin-trapping technique. A highly water-soluble Fe complex with N-(dithiocarboxy)sarcosine (DTCS) was used as an NO-trapping agent. Mice received [14N]-ISDN, and the Fe-DTCS complex subcutaneously exhibited the characteristic triplet EPR signal of the NO adduct [14NO-Fe(DTCS)2]2-. Using [15N]ISDN instead of [14N]ISDN, we were able to observe that the doublet EPR signal stemmed from the 15NO adduct, which directly demonstrated that NO was produced from ISDN. The three-dimensional EPR images of the upper abdomen of living mice showed that the NO adducts were distributed in the liver and the kidneys. This EPR image combined with the ex vivo EPR measurements of the blood suggested that NO production from ISDN occurred in the liver in this experimental condition.

Animals↗
PubMed1998

Intradermal injection of monocyte chemoattractant protein-1 induces emigration and differentiation of blood monocytes in rat skin.

BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1) is a potent chemoattractant for blood monocytes in vitro. Recent studies in MCP-1-transgenic mice revealed that the local production of MCP-1 caused monocyte infiltration. However, the kinetics of monocyte infiltration after the production of MCP-1 or the amount of MCP-1 necessary for monocyte recruitment are not known. METHODS: We purified recombinant rat MCP-1 expressed in COS-7 cells, and injected it into rat skin. The infiltrating cells were examined by immunohistochemistry and ultrastructural peroxidase cytochemistry. RESULTS: Rat recombinant MCP-1 had a molecular mass of approximately 30 kD and exhibited the peak monocyte chemotactic activity at 10(-9) M. One microgram of MCP-1 caused intra- and extravascular accumulation of mononuclear cells 3 h after injection. The cells were ED1+, indicating they were blood monocytes. The infiltration of mononuclear cells peaked at 12-24 h, and most of them were TRPM-3+ and ED3+, characteristic to exudate macrophages. None of the cells expressed ED2 or Ki-M2R antigens, markers for resident macrophages, until 3 days after injection. There was no uptake of [3H]thymidine by the infiltrating cells. Ultrastructural peroxidase cytochemistry confirmed that the infiltrating cells were monocytes and exudate macrophages. The number of OX8+ lymphocytes also peaked at 12 h, consisting of approximately 9% of the total infiltrating cells. CONCLUSION: These results indicate that MCP-1 attracts blood monocytes as early as 3 h and the infiltrating monocytes differentiate into exudate macrophages in loco. However, this effect was transient and the infiltration of monocytes did not result in tissue damage.

Animals↗
PubMed1998

Effect of 26,26,26,27,27,27-Hexafluoro-1,25-dihydroxyvitamin D3 on the expression of vitamin-D-responsive genes in vitamin-D-deficient mice.

26,26,26,27,27,27-Hexafluoro-1,25-dihydroxyvitamin D3 (ST-630) is a newly developed agent to maintain the levels of calcium and phosphorus in blood. Herein, we investigated the effect of this compound on the expression of vitamin-D-responsive genes in vitamin-D-deficient mice. ST-630 was more effective than 1, 25-dihydroxyvitamin D3 [1,25(OH)2D3] with respect to the induction of Cyp24 and calbindin-D9k mRNAs in the kidney and in the small intestine. Moreover, the increase in mRNA levels of vitamin-D-responsive genes induced by ST-630 lasted longer than that induced by 1,25(OH)2D3. These results indicate that ST-630 was more effective in inducing Cyp24 and calbindin-D9k gene expression than 1, 25(OH)2D3 when both compounds were injected into vitamin-D-deficient mice.

Animals↗
PubMed1998

Inhibition of NO synthesis induces inflammatory changes and monocyte chemoattractant protein-1 expression in rat hearts and vessels.

We recently showed that chronic inhibition of NO synthesis by N(omega)-nitro-L-arginine methyl ester (L-NAME) causes coronary vascular remodeling (ie, vascular fibrosis and medial thickening) in rats. To test the hypothesis that the inhibition of NO synthesis induces inflammatory changes in the heart, we characterized the inflammatory lesions that occurred during L-NAME administration and determined whether inflammation involved the induction of monocyte chemoattractant protein-1 (MCP-1) in vivo. During the first week of L-NAME administration to Wistar-Kyoto rats, we observed a marked infiltration of mononuclear leukocytes (ED1-positive macrophages) and fibroblast-like cells (alpha-smooth muscle actin-positive myofibroblasts) into the coronary vessels and myocardial interstitial areas. These inflammatory changes were associated with the expression of proliferating cell nuclear antigen and MCP-1 (both mRNA and protein). The areas affected by inflammatory changes, as well as the expression of MCP-1 mRNA, declined after longer (28 days) treatment with L-NAME and were replaced by vascular and myocardial remodeling. Our results support the hypothesis that the inhibition of NO synthesis induces inflammatory changes in coronary vascular and myocardial tissues and involves MCP-1 expression. Results also suggest that the early stages of inflammatory changes are important in the development of later-stage structural changes observed in rat hearts.

Animals↗
PubMed1998

Role of apoptosis of thyrocytes in a rat model of goiter. A possible involvement of Fas system.

Apoptosis, a physiological process of cell death, may modulate the mass of the thyroid gland. We investigated the role of apoptosis and the possible involvement of Fas/Fas ligand (FasL) system in apoptosis during goiter formation and involution in a rat model of goiter. Rats were fed a low iodine diet and a goitrogen, 6-propyl-2-thiouracil, to induce goiter. Rats with goiter were then fed a high iodine diet to study the phase of involution. We examined the presence of apoptosis by electron microscopy (EM) and terminal deoxy-UTP nick end labeling (TUNEL). We also investigated the association between Fas and FasL expression and thyrocyte apoptosis using immunohistochemistry and Western blotting. To evaluate the proliferation of thyrocytes, proliferating cell nuclear antigen was examined immunohistochemically. The number of apoptotic cells increased during goiter formation and the early stage of involution, which were also associated with increased number of Fas-positive thyrocytes, and some of these cells contained TUNEL-positive nuclei. However, the expression of FasL was almost constant throughout the experiment. Proliferating cell nuclear antigen/TUNEL ratio markedly increased during goiter formation but decreased particularly during the late stage of goiter involution. Our results indicate that apoptosis of thyrocytes is a main factor of cell loss during goiter formation and involution and suggest that the Fas/FasL system is involved in the induction of apoptosis of these cells. Moreover, the delicate balance between apoptosis and cell proliferation may play an important role in the control of thyroid gland mass.

Animals↗
PubMed1998

A novel mutation of the GTP-cyclohydrolase I gene in a patient with hereditary progressive dystonia/dopa-responsive dystonia.

We report a 37-year-old Japanese woman with hereditary progressive dystonia with marked diurnal fluctuation and dopa-responsive dystonia. She developed dystonia in the lower limbs at the age of 11 years, followed by spasmodic torticollis and resting tremor of the feet, which responded remarkably to low doses of levodopa (100 mg/day). Concentrations of biopterin and neopterin in CSF were decreased. Polymerase chain reaction analysis of the guanosine 5'-triphosphate cyclohydrolase I gene revealed a novel mutation (Thr186-->Lys).

Adult↗
PubMed1998

Biological and structural properties of cyclic peptides derived from the alpha-amylase inhibitor tendamistat.

Six cyclic peptides with 5, 7, 9, 11, 13, and 15 amino acids, with the inhibitory sequence of the alpha-amylase inhibitor tendamistat, were synthesized. The 11-residue peptide inhibited porcine pancreatic alpha-amylase most potently (K1 0.29 +/- 0.09 microM). For the 11-residue peptide, the circular dichroism study suggested a preliminary relationship between its inhibitory activity and structural property.

Animals↗
PubMed1998

Compensation for D-glutamate auxotrophy of Escherichia coli WM335 by D-amino acid aminotransferase gene and regulation of murI expression.

D-glutamate, an indispensable component of peptidoglycans of bacteria, is provided by glutamate racemase in E. coli cells. Compensation for D-glutamate auxotrophy of E. coli WM335 cells lacking the glutamate racemase gene, murI, with the D-amino acid aminotransferase gene suggests that presence of a threshold concentration for the D-glutamate required by E. coli cells, as well as a regulation system for murI expression.

Alanine Transaminase↗
PubMed1998

[Medical behavior after colo-rectal cancer screening--comparison with that after stomach cancer screening].

Medical behavior for intensive examination after colo-rectal cancer screening was examined in comparison with that after stomach cancer screening. Examinees who were positive in colo-rectal or stomach cancer screening, provided by an Occupational Health Organization from April 1993 to March 1994, were monitored for their medical behavior through notifications from physicians. The main results were as follows: 1. The proportion of those with the notification from a physician after colo-rectal cancer screening was half of that after stomach cancer screening. 2. Among those notified the rate of those who undertook intensive examination by the end of 12 weeks after the screening was 79.7% for a colo-rectal site and 87.0% for the stomach. The time interval from the screening to the intensive examination for the colo-rectal site was significantly longer than that for stomach. 3. For colo-rectal cancer screening, the proportion of those with the notification was lower in females than in males, and in those aged less than 50 than in those aged 50 or older. There were no differences in the proportion between those screened at the work site and those at the occupational health service center, and between those positive in the fecal occult blood test and those negative in the test but positive in the health interview. These results indicated, assuming that the probability of the physicians' notification was unrelated to the type of examination, a smaller proportion of the examinees positive in the colo-rectal cancer screening consulted a physician for the intensive examination later than those positive in the stomach cancer screening. It is therefore necessary to make colo-rectal cancer screening effective to establish a collaborating system which effectively facilitates the medical behavior of the screening positives.

Adult↗
PubMed1998

Relationship between serum 1,5-anhydroglucitol and urinary excretion of N-acetylglucosaminidase and albumin determined at onset of NIDDM with 3-year follow-up.

OBJECTIVE: This prospective study was designed to elucidate the relationship between the serum level of 1,5-anhydroglucitol (1,5AG) and the urinary excretion of N-acetylglucosaminidase (NAG) and albumin in patients who were in the early stages of diabetes. RESEARCH DESIGN AND METHODS: A total of 1,062 male nondiabetic subjects with impaired glucose tolerance were monitored for blood glucose level once every 2-3 months, and the values were evaluated. Of these 1,062 subjects, 112 showed a worsening of glycemia during the observation period to the level seen in diabetes. We began to monitor the glycemia and parameters of renal damage in the 112 patients from the onset of diabetes. RESULTS: The urinary excretion of NAG and albumin were elevated even at the onset of diabetes. The abnormal excretion of NAG and albumin was associated with a change in serum 1,5AG and was quickly reversible when the serum 1,5AG improved. In the 3 years after the onset of diabetes, we obtained at least 18 measurements of one parameter for each patient and calculated the mean. Urinary NAG was found to be significantly correlated with the fasting plasma level of glucose (FPG; r = 0.512, P < 0.0001), the level of HbA1 (r = 0.351, P = 0.001), and the level of 1,5AG (r = -0.790, P < 0.0001). The urinary excretion of albumin was weakly but significantly correlated with levels of FPG (r = 0.383, P < 0.0001) and HbA1 (r = 0.337, P < 0.0001), but it was more strongly correlated with 1,5AG (r = -0.632, P < 0.0001). The level of 1,5AG was significantly correlated with FPG (r = -0.681, P < 0.0001) and HbA1 (r = -0.609, P < 0.0001). CONCLUSIONS: When the renal damage is not severe, the serum level of 1,5AG appeared to be an indicator of the reversible renal damage caused by hyperglycemia, as well as of the severity of the glycemia itself.

Acetylglucosaminidase↗
PubMed1998

In vivo nitric oxide detection in the septic rat brain by electron paramagnetic resonance.

To detect nitric oxide (NO) in the rat brain during lipopolysaccharide (LPS)-induced sepsis, electron paramagnetic resonance (EPR) was employed with the NO trapping technique, using an iron and N,N-diethyldithiocarbamate (DETC) complex. An X-band (about 9.5 GHz) EPR system detected a triplet signal (g = 2.038) derived from an NO-Fe-DETC complex being superimposed on the g(perpendicular) signal of Cu-DETC complex at liquid nitrogen temperature. The height of the triplet signal peaked seven hours after injection of 40 mg/kg of LPS, and over 25 x 10(4) U/kg of IFN-gamma enhanced the LPS-induced NO formation. Pretreatment with N(G)-monomethyl-L-arginine (NMMA), an NO synthase inhibitor, deleted only the triplet signal. A triplet signal (g(iso) = 2.040, aN = 1.28 mT) derived from the NO-Fe-DETC complex was also observed at ambient temperature. Then, a home-built 700 MHz EPR system was used to detect an NO signal in the septic rat brain in vivo. We successfully monitored the NO-Fe-DETC signal in the head region of a living rat under the condition that provided maximum height of the NO-Fe-DETC signal in the X-band EPR study. Pretreatment with NMMA again deleted the NO-Fe-DETC signal. This is the first EPR observation of endogenous NO in the brain of living rats.

Animals↗
PubMed1998

Cystothiazoles A and B, new bithiazole-type antibiotics from the myxobacterium Cystobacter fuscus.

New bithiazole-type antibiotics, cystothiazoles A (C20H26N2O4S2) and B (C20H26N2O5S2), have been isolated from a culture broth of the myxobacterium, Cystobacter fuscus. The gross structures of these compounds were elucidated by spectroscopic analysis, and their absolute stereochemistry was determined by chemical degradation of cystothiazole A. Cystothiazole A inhibits fungi and human tumor cells, whereas it is inactive against bacteria. The antifungal activity appears to result from the inhibition of submitochondrial NADH oxidation. Although these compounds are structurally related to the known antibiotic myxothiazol, cystothiazole A was more active against fungi and less cytotoxic than myxothiazol.

Anti-Bacterial Agents↗
PubMed1998

[A case of multiple sclerosis associated with myelin associated glycoprotein neuropathy].

A 28-year-old woman had developed chronic, recurrent, visual disturbance (bilateral), and girdle sensation at Th 5-6. She was admitted to our hospital because of left visual disturbance, distal limb weakness on right side, and numbness of four extremities. The neurological examination revealed decreased visual acuity of the left eye with abnormality of the optic disk, moderate muscle weakness of the right upper and lower extremities, absent tendon reflexes and paresthesia on distal portions of the four limbs. Laboratory examinations disclosed the titration of anti-myelin associated glycoprotein (MAG) antibody (IgM) and CSF protein was elevated (104 mg/dl). Motor nerve conduction studies revealed conduction block in more than one nerve. The conduction velocities in the upper and lower extremities were all diminished. P100 latency was prolonged by flash visual evoked potential (VEP) studies. N13-N20 interpeak latency of somatosensory evoked potential (SEP) of median nerve was also prolonged. She was treated with steroid pulse therapy, followed by an oral dose of 30 mg/day of prednisolone. Her symptoms resolved completely three months later, and multifocal conduction block subsided on electrophysiological study. There are some cases of multiple sclerosis with multifocal conduction block, but such a case is very rare in Japan. We discussed the pathogenic mechanisms of these conditions, and we conclude that we must take notice of demyelinating neuropathy in multiple sclerosis and that nerve conduction studies are useful for detecting them.

Adult↗
PubMed1998

Effects of a nitric oxide synthase inhibitor on pressor response to angiotensin II in conscious rats.

OBJECTIVE: We sought to characterize the effects of NG-monomethyl-L-arginine (L-NMMA) and L-arginine (L-Arg) on the pressor response to the infusion of angiotensin II in rats. METHODS: L-NMMA and L-Arg were infused intraperitoneally into rats at a constant rate by means of an osmotic minipump. The L-NMMA group received an infusion of L-NMMA (3 mg/d) daily for 13 d, whereas the L-NMMA plus L-Arg group received L-NMMA (3 mg/d) daily for 4 d, followed by L-NMMA plus L-Arg (12 mg/d) daily for 9 d. Sham operated rats served as controls. The animals were anesthetized on day 13, and catheters were placed into the femoral artery and vein. After the animals had recovered from the anesthesia, the pressor response to intravenous bolus doses of angiotensin II (50, 100, 200, and 400 ng/kg) were determined after recovery from anesthesia. RESULTS: While the baseline mean arterial blood pressure was not affected by L-NMMA, with or without L-Arg, the pressor response to angiotensin II in the L-NMMA group was significantly increased as compared with that in the control group, at doses of 50, 100, and 200 ng/kg. The response of the L-NMMA plus L-Arg group did not differ significantly from that of the control group. CONCLUSION: Results indicate that the infusion of a nitric oxide synthase inhibitor, at a dose insufficient to produce hypertension, increases the pressor response to angiotensin II.

Acetylglucosaminidase↗