Search PubMed⌕ Search

Biomedical subjects

Y Fujimoto

Publications and source records attributed to Y Fujimoto.

At least 235 records · Page 13Linked to original sources
PubMed1995

Hederagenin glycosides from Pometia eximia.

Seven new saponins, all glycosides of hederagenin (3 beta,23- dihydroxyolean-12-en-28-oic acid), were isolated from the stem of Pometia eximia along with hederagenin and two known saponins. Their structures were established as 28-O-beta-D-apiosyl(1-->2)-beta-D-glucopyranosyl-, 3-O-alpha-L- arabinofuranosyl(1-->3)[alpha-L-rhamnopyranosyl (1-->2)]-beta-D- xylopyranosyl-, 3-O-beta-D-apiosyl(1-->3)[alpha-L-rhamnopyranosyl-(1-->2)-beta-D- glucopyranosyl-, 3-O-alpha-L-arabinofuranosyl(1-->3)[alpha-L-rhamnopyranosyl- (1-->2)]-beta-L-arabinopyranosyl-, 3-O-beta-D-xylopyranosyl(1-->3)[alpha-L- rhamnopyranosyl(1-->2)]-alpha-L-arabinopyranosyl-, 3-O-beta-D-xylopyranosyl-(1-->3)[alpha-L-rhamnopyranosyl(1-->2)]-beta-D- glucopyranosyl-, 3-O-beta-D-galactopyranosyl(1-->3)[alpha-L-rhamnopyranosyl(1-->2)]-beta- D- glucopyranosyl-hederagenins.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1995

Conditioned taste aversion in rats with excitotoxic brain lesions.

Conditioned taste aversion (CTA) is well known to be a robust and long-lasting learning after a single conditioned stimulus (CS) (taste)--unconditioned stimulus (US) (malaise) pairing. The neural mechanisms of this taste aversion learning still remain to be resolved. To elucidate the basic brain mechanisms of the taste aversion learning, we examined the effects of lesions of various sites of the rat brain on the acquisition and retention of CTAs. Confined brain lesions were made by injections of a small amount of excitotoxic drug, ibotenic acid. CTAs were established to saccharin (CS) by pairing its ingestion with an i.p. injection of LiCl (US). Rats lacking the parabrachial nucleus (PBN) almost completely failed to acquire CTAs. The second most effective lesion was in the medial thalamus including the parvocellular part of the ventral posteromedial nucleus of the thalamus (VPMpc) and the midline part, followed by the damage of the lateral nuclear group of the amygdala including the basolateral amygdaloid nucleus. Lesions of the gustatory cortex (GC) and hippocampus induced moderate effects, but lesions in the other subnuclei of the amygdala, such as the medial and central amygdaloid nuclei, entorhinal cortex, lateral hypothalamic area, and ventromedial hypothalamic nucleus induced slight or no effects. On the other hand, paired lesions among the amygdala, medial thalamus and GC caused severe impairment of CTAs; in particular, lesions of amygdala and VPMpc completely disrupted acquisition of CTAs. These results suggest that the PBN, medial thalamus and the lateral nuclear group of the amygdala play an essential role in the formation of taste aversion learning.

Animals↗
PubMed1995

Effects of fatty acids and fatty acyl CoA esters on Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase in rabbit liver.

Effects of various fatty acids and fatty acyl CoA esters on Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase in rabbit liver were examined. Cu2+ (2-10 microM) brought about the conversion of xanthine dehydrogenase to oxidase in a dose-dependent manner. Oleic, arachidonic, eicosapentaenoic, and docosahexaenoic acids (50-200 microM) prevented the conversion of xanthine dehydrogenase to oxidase catalyzed by 6 microM-Cu2+. The effect of these four fatty acids was concentration-dependent, whereas palmitic, stearic, and linoleic acids had no effect on the conversion of xanthine dehydrogenase to oxidase at the same concentration range. On the other hand, palmitoyl, linoleoyl, and arachidonoyl CoAs elicited the inhibition of 6 microM-Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase at concentrations of 50, 100, and 200 microM. These results suggest that oleic, arachidonic, eicosapentaenoic and docosahexaenoic acids, and fatty acyl CoAs have the potential to inhibit the conversion of xanthine dehydrogenase to oxidase in rabbit liver.

Acyl Coenzyme A↗
PubMed1995

Effects of fatty acyl coenzyme A esters on lipoxygenase and cyclooxygenase metabolism of arachidonic acid in rabbit platelets.

The effects of fatty acyl coenzyme A (CoA) esters (palmitoyl-, stearoyl-, oleoyl-, linoleoyl- and arachidonoyl--CoA) on the activities of lipoxygenase and cyclooxygenase in rabbit platelets were examined. Palmitoyl-, stearoyl-, oleoyl- and linoleoyl- CoA were potent inhibitors of platelet lipoxygenase activity. In addition to the lipoxygenase, the four fatty acyl-CoA esters elicited inhibitory activity on platelet cyclooxygenase, although the inhibition was a little weaker. The CoA derivative of the icosanoid precursor arachidonic acid (AA) showed little inhibition on lipoxygenase and cyclooxygenase. Palmitic, stearic and oleic acids had little or no effect on lipoxygenase and cyclooxygenase, in contrast with their CoA derivatives. Linoleic acid was more potent than linoleoyl-CoA as an inhibitor of the cyclooxygenase, but it was a weak inhibitor of the lipoxygenase. These results suggest that the CoA derivatives of palmitic, stearic, oleic and linoleic acids have the potential to modulate both platelet lipoxygenase and cyclooxygenase activities and may have functional effects within platelets.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1995

Is CD26/dipeptidyl peptidase IV a really important molecule in T cell activation of a certain rat strain?

A new monoclonal antibody (MS-7 mAb) was raised to investigate the real role of the membrane-associated molecule CD26/dipeptidyl peptidase IV (DPP IV; EC 3.4.14.5), which transduces activation signals in T cells. A strain of rats which is deficient in DPP IV was used. MS-7 mAb recognized DPP IV (110 kDa) and its 60 kDa fragment, starting at the 281st residue corresponding to the extracellular one comprising the active-site sequence Gly-X-Ser631-X-Gly of DPP IV. MS-7 mAb recognized CD26 on T cells of DPP IV+ rats both before and after mitogen activation. CD26 expression and DPP IV enzyme activity are increased on T cells following their activation; nevertheless, no CD26 was expressed on T cells of DPP IV- rats, and no DPP IV enzyme activity was detected either before or after mitogen activation. In addition, MS-7 mAb inhibited the mitogen-stimulated proliferation of DPP IV+ rats, but did not affect that of DPP IV- rats. These results suggest that CD26/DPP IV is not a necessary molecule in T cell activation, and that there is some other bypass in T cell activation of DPP IV- rats.

Amino Acid Sequence↗
PubMed1995

Endometrial oestrogen and progesterone receptors and their relationship to sonographic endometrial appearance.

The present study was undertaken to evaluate a possible relationship between the endometrial concentrations of oestrogen receptor (ER) or progesterone receptor (PR), and the sonographic appearance of human endometrium. Sonographic assessments and aspirations of the endometrium at the time of or prior to ovulation were made in 48 cycles of 45 infertile women. Endometrial patterns were classified as A, triple line pattern, or B, not triple line, on the basis of echogenicity. We did not find a correlation between ER or PR and serum oestradiol or endometrial thickness. Furthermore, serum oestradiol concentrations were not correlated with endometrial pattern or thickness. The only significant correlations were found between the concentrations of ER and PR in the pattern A endometrium (r = 0.80, P < 0.01) and in the pattern B endometrium (r = 0.49, P < 0.05). There were no differences in the mean concentrations of ER and PR despite differences in endometrial pattern and thickness. However, PR was measured at > 800 fmol/mg protein in 12 out of 38 pattern A endometria, while PR was < 800 fmol/mg protein in all pattern B endometria. These data suggest that high PR expression in the pre-ovulatory period is related to an adequate endometrial growth and thereby increases the responsiveness of the endometrium to progesterone stimulation after ovulation.

Buserelin↗
PubMed1995

Inhibition of food-borne pathogenic bacteria by bacteriocins from Lactobacillus gasseri.

Lactobacillus acidophilus group and a Lact. reuteri isolated from human faeces were examined for production of antimicrobial agents against 16 strains of six species of food-borne enteric pathogenic bacteria. Several strains of Lact. gasseri showed wide inhibitory activity against the tested bacteria. Gassericin A produced by Lact. gasseri LA39 was one of the most widely active bacteriocins. It was bactericidal without causing cell lysis.

Adult↗
PubMed1995

Cold acclimation induces zonal heterogeneity in gluconeogenic responses to glucagon in rat liver lobule.

The relationship between the enhanced responses of gluconeogenesis to norepinephrine (NE) and glucagon and its zonal distribution was studied in liver lobules of cold-exposed rats by examination of preparations enriched for periportal hepatocytes (PP-H) and for perivenous hepatocytes (PV-H) by the digitonin-collagenase perfusion technique. In the control group, gluconeogenesis from lactate (10 mM) plus pyruvate (1 mM) was higher in PP-H than in PV-H. NE (100 nM) and glucagon (100 nM) increased the rate of gluconeogenesis by 80 and 70%, respectively, in both PP-H and PV-H. Gluconeogenesis in PP-H was unchanged by cold exposure. The rate in PV-H increased to the rate in PP-H at 5 days after cold exposure, and then the rate returned to the control value at 20 days. The gluconeogenic response to the alpha-adrenergic action of NE in both PP-H and PV-H doubled after 5 days. The response to glucagon tripled in PP-H and was cut in half in PV-H after 20 days. Phorbol 12-myristate 13-acetate (PMA; 1 microM), A-23187 (100 nM), and dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP; 1 mM) increased the rate of gluconeogenesis by 200, 100, and 80%, respectively, in both PP-H and PV-H from the control group. The responses to PMA and A-23187 were unchanged by exposure to cold. The response to DBcAMP was doubled in PP-H and was cut in half in PV-H after 20 days of cold exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1995

Novel assay system favorable for the study of cell-to-cell transmission of HIV-1 and its application to the evaluation of anti-HIV drugs.

The cell-to-cell transmission of human immunodeficiency virus type 1 (HIV-1) was studied using MOLT-4 cells chronically infected with a variant strain of HIV-1SF-2 (MOLT-4/HIV-1SF-2H) and CD4+ human lymphoid MT-4 cells. MOLT-4/HIV-1SF-2H cells produced less than 1 TCID50 infectious particles per day as determined by the cytopathogenicity in MT-4 cells. However, the expression of envelope glycoproteins gp120 and gp41 on the MOLT-4/HIV-1SF-2H cell membrane was satisfactory for syncytium formation with the uninfected MOLT-4 cells. When MOLT-4/HIV-1SF-2H and MT-4 cells were co-cultured, severe cytopathogenicity was observed in MT-4 cells without being accompanied by the formation of multi-nucleated cells. Thus, the system consisting of MOLT-4/HIV-1SF-2H and MT-4 cells is convenient for exclusive study of the mechanism of cell-to-cell transmission of HIV-1. Using various compounds, it was confirmed that cell-to-cell transmission required both gp120/gp41-CD4 binding and de novo DNA synthesis.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Structure-activity correlationship and strain specificity of polyoxometalates in anti-human immunodeficiency virus activity.

The anti-human immunodeficiency virus (HIV) activity of polyoxometalates of representative structural families, such as Keggin, lacunary Keggin, trivacant Keggin, Keggin sandwich, Wells-Dawson and Wells-Dawson sandwich, was determined using two strains of HIV type 1 (HIV-1HTLV-IIIB and HIV-1SF-2H). The compounds were preferably selected to cover both polyoxotungstates and polyoxomolybdates in each structural family. In general, polyoxotungstates of Keggin, lacunary Keggin, trivacant Keggin, Keggin sandwich, Wells-Dawson and Wells-Dawson sandwich structures showed anti-HIV-1HTLVIIIB activity, whereas most compounds not included in these structural categories were inactive. Among the compounds with a potent anti-HIV-1HTLV-IIIB activity, those of Keggin and its closely related structural families (lacunary Keggin, trivacant Keggin and Keggin sandwich) inhibited the cytopathogenicity and syncytium formation caused by HIV-1SF-2 to a much higher extent compared with HIV-1HTLV-IIIB-related ones. The difference between the spectra of anti-HIV-1HTLV-IIIB activity and the specificity for HIV-1SF-2H might result from differential structural requirements in these functions.

Antiviral Agents↗
PubMed1995

Identification of an alanine aminopeptidase in human maternal serum as a membrane-bound aminopeptidase N.

In addition to cystine aminopeptidase (oxytocinase) alanine aminopeptidase is present at high levels in the serum of pregnant women. In this study we compared the enzyme with membrane-bound aminopeptidase N purified from human placenta. Comparison of catalytic and immunological properties and N-terminal sequence analyses revealed that the enzymes were differentially processed derivatives of the same protein, and that the N-terminal 68 residues of aminopeptidase N were deleted in the alanine aminopeptidase. The deleted sequence contains a small cytoplasmic region, a hydrophobic transmembrane domain and a junctional domain. These results suggest that the enzyme may be released into the maternal circulation as a result of lacking these three domains.

Amino Acid Sequence↗
PubMed1995

[A case of Sjögren's syndrome with rheumatoid arthritis manifesting transverse myelitis with antineuronal antibody].

We report a sixty-year-old woman with transverse myelitis who had suffered from rheumatoid arthritis since age of 52. She was admitted to our department because of muscle weakness and painful tonic spasm in the bilateral lower extremities, sensory disturbance below the mamillary level and bladder disturbance. She had sicca symptoms. As a result of sialography, Sjögren's syndrome was diagnosed. Antineuronal antibody was found in the sera of the patient. She had no symptom of systemic vasculitis. Lupus anticoagulant and anticaldiolipin antibody were negative. The pathogenesis of transverse myelitis in rheumatic disease is still uncertain. Vasculitis and the immunological reaction of antineuronal antibody have been suggested as possible causes. This report suggests the influence of direct immunological reaction on the central nervous system.

Arthritis, Rheumatoid↗
PubMed1995

Midbrain paralemniscal projections to the facial nucleus: an anatomical and immunohistochemical study.

Serial 30 microns-thick sections through the midbrain tegmentum were stained with cresyl violet. The PL was found to be situated along the medial edge of the lateral lemniscus. The PL consisted of small- (10-15 microns) and medium-sized neurons (25-35 microns), and was the most prominent at the caudal level of the superior colliculus. In order to confirm the existence of the inhibitory paralemniscal-facial pathway, a combined HRP and immunohistochemical technique was use in the rat. This experiment revealed that 10.9% of the total number of GABA immunoreactive PL neurons also labeled with HRP after HRP injection was made in the medial part of the facial nucleus (FN). Electron microscopic observations were carried out on the medial part of the facial nucleus (FN) after kainic acid injection was made into the contralateral PL in the cat. The majority of degenerating PL fibers were ranged from 0.5 to 3.1 microns in diameter and made synaptic contacts with somata, proximal dendrites and dendritic profiles. These fibers, containing either round or pleomorphic vesicles, formed asymmetrical or symmetrical synapses. It was of particular interest in the present study that 40.7% of the total number of degenerating fibers make synaptic contacts with large dendrites more than 3.0 microns in diameter.

Animals↗
PubMed1995

A far-upstream sequence of the wheat histone H3 promoter functions differently in rice and tobacco cultured cells.

The cis-regulatory function of a far-upstream sequence (-1,711 to -186) of the promoter of the wheat gene for histone H3 (TH012) was analyzed in cultured rice and tobacco cells in a transient expression system with the gene for beta-D-glucuronidase as a reporter gene. The far-upstream sequence was necessary for full activity of the H3 promoter in rice cells but did not enhance the activity of the proximal promoter in tobacco cells. Dissection analysis of the far-upstream sequence revealed the existence of several positive and negative cis-acting sequences in this region, some of which functioned differently in rice and tobacco cells. In gain-of-function experiments with rice cells, the sequence from -848 to -704, containing the CCAAT and octamer (CaCGGATC) motifs, functioned in an orientation-independent manner, whereas the sequence from -703 to -486 functioned in an orientation-dependent manner. By contrast, both sequences exhibited an orientation-dependent cis-function in tobacco cells. These findings suggest that some cis-regulatory sequences in the far-upstream region of the H3 promoter function differently in rice and tobacco cells.

Base Sequence↗
PubMed1995

[A study of heel-knee tapping test in cerebellar ataxia by a motion measurement system].

It is often difficult to estimate slight alterations in the severity of ataxia by bed-side neurological examinations. We analyzed the heel-knee tapping test, which has often been used as a standard bed-side examination to check incoordination in lower limbs, using a new motion measurement system "video/computer motion measurement system". We studied 9 normal controls and 21 patients with spinocerebellar degenerations (SCD). In patients with SCD, the up-and-down motion range of the heel was variable and the heel moved in the anterior-and-posterior direction, because of knee sways during the test. Following oral administration of TRH analogue, TA-0910, above-mentioned findings were clearly improved. Analysis of spatial and time elements of the knee joint demonstrated quantitative improvement. Therefore, an effect of TA-0910 on incoordination of the lower limbs could be proved objectively by a computer motion measurement system.

Adult↗
PubMed1994

Existence of an enzymatic pathway furnishing arachidonic acid for prostaglandin synthesis from arachidonoyl CoA in rabbit kidney medulla.

We examined whether arachidonoyl CoA (AA-CoA) can be a possible supplier of arachidonic acid (AA) for prostaglandin (PG) synthesis in rabbit kidney medulla. AA-CoA was preincubated with or without the 105,000 g supernatant (cytosol) fraction from the kidney medulla for 5 min at 37 degrees C followed by the incubation with the microsomal fraction (0.5 mg protein) (a rich source of PG synthesizing enzymes) in the presence of reduced glutathione and hydroquinone for 5 min at 37 degrees C, and the formed PGE2, F2 alpha and D2 were measured by high-pressure liquid chromatography using 9-anthryldiazomethane for derivatization. The addition of AA-CoA (20 nmol) alone changed the total PG formation (the sum of PGE2, F2 alpha and D2) from 0.14 to 1.55 ng. When the cytosolic fraction (10-100 microliters) was added together with 20 nmol-AA-CoA in the preincubation mixture, total PG formation was further increased 2- to 3-fold compared to AA-CoA alone. Experiments utilizing AA, instead of AA-CoA and boiled cytosolic fraction revealed that the stimulatory action of the cytosolic fraction on the AA-CoA-induced PG synthesis may not be due to the effect on cyclooxygenase activity and due to long-chain acyl CoA hydrolase. These results show that long-chain acyl CoA hydrolase which hydrolyzes AA-CoA to AA is present in the cytosol of rabbit kidney medulla and suggest that this enzyme activity is a potential mediator of supply of AA for PG synthesis in this region.

Acyl Coenzyme A↗