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Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 181 records · Page 10Linked to original sources
PubMed1998

Cell-mediated autoimmune response to testis induced by bilateral testicular injury can be suppressed by cyclosporin A.

PURPOSE: Since the delayed type hypersensitivity (DTH) response to testis antigens plays a key role in the induction and/or maintenance of experimental autoimmune orchitis (EAO), an animal model for human immunological male infertility or aspermatogenesis, we have investigated the immunosuppressive effect of cyclosporin A (CsA) on the DTH response to autologous testicular cells (TC). MATERIALS AND METHODS: A DTH response to autologous TC was induced in C3H/HeN mice by bilateral testicular injury (trauma). CsA was administered intraperitoneally for 10 consecutive days before and after injury. A DTH response was assessed by measuring delayed footpad reaction (DFR) to autologous TC 9 days after injury. RESULTS: When the mice were traumatized alone, 10 mg./kg. or more of CsA suppressed the DTH response to autologous TC significantly. In mice traumatized with 100 mg./kg. of cyclophosphamide (CY)-pretreatment, 30 mg./kg. or more of CsA was needed to suppress the DTH response. In mice traumatized with 200 mg./kg. of CY-pretreatment, 50 mg./kg. of CsA was needed to suppress the autoimmune response. CONCLUSIONS: The DTH response to autologous TC was suppressed significantly by administration of CsA in a dose-dependent manner. We have also shown the direct suppressive effect of CsA on effector cells for DTH by means of local passive transfer of DTH. Administration of CsA had no augmenting or suppressive effect on suppressor cells for DTH. CsA might be a significant drug for the immunosuppression of EAO and possibly for immunological male infertility.

Animals↗
PubMed1998

Time course of changes in the intestinal permeability of food-sensitized rats after oral allergen challenge.

Rats were sensitized with ovalbumin (OVA) with a molecular weight of 45 kd, challenged with OVA orally, followed by orally administered beta-lactoglobulin (BLG) as an intestinal permeability marker. BLG is a macro-molecular protein with a molecular weight of 18 kd. Blood BLG concentrations were measured (by ELISA) serially over 4 hours following BLG administration, which in turn was given 1 hour after OVA challenges. The maximum BLG concentration was at 2 hours. BLG was then administered orally 1, 3, 6, 12 and 24 hours after oral OVA challenge, and the serum BLG concentration at 2 hours after BLG administration was compared among the five groups. BLG appeared in the circulation of the animals 1, 6 and 24 hours after allergen challenge, but not after 3 and 12 hours. The serum BLG concentration was not significantly different at 1, 6 and 24 hours. Histopathological examinations of the intestines showed mast cell infiltration of the intestinal mucosa at 1 hour, remarkable edema of villi at 3 hours, eosinophil infiltration at 6 hours, an increase of goblet cells at 12 hours and villous atrophy and lymphocyte infiltration at 24 hours. The appearance in the serum of three BLG peaks of comparable heights suggested that the intestinal absorption of BLG may be related to a late and delayed phase as well as the immediate IgE-dependent phase response.

Administration, Oral↗
PubMed1998

Bile acids influence hepatic chemiluminescence in normal and oxidative-stressed rats.

The aim of the present study was to clarify whether bile acids influence chemiluminescence (CL) in the liver in vivo. Hepatic CL was determined on the surface of the liver of anaesthetized rats by using a photon counter. In normal rats, hepatic CL was significantly decreased 30 min after enteral administration of chenodeoxycholic acid (CDCA) or deoxycholic acid (DCA), but returned to its initial level 3 h later, after part of the CDCA administered was metabolized. Ursodeoxycholic acid (UDCA) and cholic acid had no effect on CL. In contrast, hepatic CL was markedly increased 30 min after CDCA or DCA administration in rats given either buthionine sulphoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, or diethyldithiocarbamate (DDC), an inhibitor of both superoxide dismutase and glutathione peroxidase. Chenodeoxycholic acid further increased the CL of BSO- or DDC-treated rats during inhalation of oxygen via a tracheal cannula. Coadministration of UDCA eliminated the effects of CDCA on the hepatic CL of normal and BSO- or DDC-treated rats with or without oxygen inhalation. We conclude that cytotoxic bile acids, such as CDCA, increase CL in the antioxidants-depleted or oxidative-stressed liver in vivo, but that UDCA prevents CDCA from developing CL.

Animals↗
PubMed1998

Patient background of the Pokemon phenomenon: questionnaire studies in multiple pediatric clinics.

Many children in Japan developed various neuropsychological problems, including seizures, while watching the program Pocket Monster, televised on 16 December 1997. To examine the basis for this incident, we have performed a survey of volunteering children and their parents who visited our pediatric clinics for other reasons from 8 January to 28 February 1998. Children and their parents filled out questionnaires. Among the total of 662 children surveyed, the great majority (603, 91.1%) was found to have watched the Pocket Monster program and 30 individuals (5.0% of viewers) complained of variable degrees of neuropsychological abnormalities. These included seizures (two cases), headache (nine cases), nausea (eight cases), blurred vision (four cases), vertigo (two cases), dysthymia (two cases) and vomiting (one case). Nearly half (14) of these children developed symptoms during or immediately after watching the program, while the remainder did so later. Representative cases are reported and other statistical aspects are discussed.

Adolescent↗
PubMed1998

Demonstration of putative Ca-binding domains in dentin matrix of rat incisors after daily injections of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP).

In order to clarify the initial process of dentin mineralization, the inhibitory effect of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) on dentin mineralization was investigated. Rats (100 g) were subcutaneously injected with HEBP (8 mg P/kg) for 7 or 14 d, and the incisors were processed for Ca histochemistry and/or electron microscopy. HEBP-treated incisors demonstrated ladder-like alternate rows of mineralized and non-mineralized dentin at the apical end. GBHA revealed moderate Ca reactions in the non-mineralized circumpulpal dentin matrix where electron microscopy revealed rich distribution of fine mesh-like electron-dense material. Non-mineralized mantle dentin matrix was negative for Ca but contained numerous matrix vesicles (MVs) filled with crystalline and/or amorphous mineral deposits. Mineralization of circumpulpal dentin occurred independently of MV-rich mantle dentin layer in affected specimens. Our data provide histochemical evidence of possible Ca-binding property of the circumpulpal dentin matrix and its absence in the mantle dentin where MV-mediated mineralization occurs. In the mantle dentin, HEBP does not interfere with crystal growth in MVs but inhibits its outgrowth after membrane rupture. It is proposed that circumpulpal dentin matrix has a potential to mineralize independently of MV-mediated mineralization of mantle dentin, although MVs determine the initial site and timing of dentin mineralization.

Aminophenols↗
PubMed1998

Evidence that folliculo-stellate cells mediate the inhibitory effect of Japanese kampo medicine, unkei-to, on growth hormone secretion in rat anterior pituitary cell cultures.

PROBLEM: Cytokine-induced neutrophil chemoattractant (CINC) was reported to influence anterior pituitary hormone release. We recently found that Unkei-to, one of the Japanese Kampo medicines, stimulated CINC secretion by rat anterior pituitary cells and the pituitary folliculo-stellate (FS)-like cell line (TtT/GF). Therefore, the effect of Unkei-to on growth hormone (GH) secretion by rat anterior pituitary cells was investigated. METHOD OF STUDY: Dispersed normal anterior pituitary cells, the folliculo-stellate-like cell line TtT/GF, and the GH3 cell were used to test the effect of Unkei-to on GH secretion. In reconstitutive coculture experiments, TtT/GF cells were mixed with GH3 cells at a ratio (TtT/GF cells: GH3 cells) of 1:99. From this mixture, cells were seeded onto plates at a density of 10(4) cells/well and were cultured for 5 days. The cells were then used in the experiments. RESULTS: Unkei-to at 20 micrograms/ml significantly inhibited GH secretion by normal anterior pituitary cells within 12 hr of incubation. In contrast Unkei-to stimulated GH secretion by GH3 cells in a time- and dose-dependent manner, suggesting that an accessory cell type was involved. To assess the contribution of CINC as a paracrine factor, an experiment using a reconstitutive coculture system was performed, and Unkei-to was found to inhibit GH secretion when GH3 cells were cocultured with TtT/GF cells. The addition of anti-CINC antibody to the reconstitutive coculture system antagonized Unkei-to-inhibited GH secretion. CONCLUSION: CINC, which was secreted from FS cells by Unkei-to, may be responsible for mediating the inhibitory effect of Unkei-to on GH secretion by rat anterior pituitary cells.

Animals↗
PubMed1998

The herbal medicine unkei-to stimulates cytokine-induced neutrophil chemoattractant production in the pituitary folliculo-stellate-like cell line (TtT/GF).

PROBLEM: We previously reported that a cytokine-induced neutrophil chemoattractant (CINC) was produced in the pituitary gland and that it influenced anterior pituitary hormone release. In this study we investigated the effect of Unkei-to, a Japanese herbal medicine, on CINC production in the rat anterior pituitary gland and the pituitary folliculo-stellate-like cell line (TtT/GF). METHOD OF STUDY: Dispersed normal anterior pituitary cells and the folliculo-stellate-like cell line TtT/GF were used to test the effect of Unkei-to on CINC secretion and CINC mRNA accumulation. Concentrations of CINC in the conditioned media were measured by an enzyme-linked immunosorbent assay, and levels of CINC mRNA were analyzed by Northern blot analysis. RESULTS: Unkei-to (20 micrograms/ml) significantly increased the secretion of CINC by normal anterior pituitary cells within 12 hr of incubation. Unkei-to also stimulated CINC secretion from TtT/GF cells in a time- and dose-dependent manner. Unkei-to (20 micrograms/ml) increased CINC mRNA accumulation in TtT/GF cells within 3 hr of incubation and also caused a 13-fold increase in the secretion of CINC from TtT/GF cells compared with the vehicle group within 24 hr of incubation. Finally, we found that some of the Unkei-to's ingredients, Evodiae fructus and Pinelliae tuber, markedly stimulated CINC secretion from TtT/GF cells. CONCLUSIONS: Our results will help to elucidate the mechanism behind the clinical effect of Unkei-to on the anterior pituitary gland. They also suggested the presence of special substances, which stimulate CINC secretion, within Unkei-to's ingredients such as E. fructus and P. tuber.

Animals↗
PubMed1998

Effect of immunotherapy on the production of eosinophil adhesion-inducing activity from mononuclear cells in house-dust-mite-sensitive bronchial asthma.

An initial step of eosinophil (EOS) accumulation in the sites of allergic inflammation is the adhesion to endothelial cells. There is increasing evidence that immunotherapy (IT) modulates the production of cytokines from mononuclear cells and hence attenuates allergic inflammation. To examine whether IT modifies the production of factor(s) which induce EOS adhesion, peripheral blood mononuclear cells (PBMC) from house-dust-mite-sensitive asthmatics treated with or without IT were cultured for 96 h in the presence or absence of 1/microg/ml Dermatophagoides farinae antigen. EOS were isolated from the peripheral blood of healthy subjects. EOS adhesion-inducing activity (EAIA) in the PBMC culture supernatants was examined by the ability to modify EOS adhesion to paraformaldehyde-fixed human umbilical vein endothelial cells (HUVEC) which were stimulated with IL-4 plus TNF-alpha. In asthmatics without IT, the addition of D. farinae antigen significantly promoted the production of EAIA from PBMC (EOS adhesion: 22.4+/-13.1% by medium control vs. 30.5+/-18.9% by D. farinae, n=10, p=0.023). This enhancing effect was blocked by an anti-beta2-integrin antibody. In contrast, the addition of D. farinae did not modulate EAIA production from PBMC in asthmatics treated with IT (23.1+/-10.3% vs. 21.5+/-12.3%, n=10, p=NS). These results suggest that IT induces the inhibition of antigen-dependent production of EAIA from PBMC. This may contribute to the inhibitory effect of IT on eosinophil recruitment in allergic inflammation.

Animals↗
PubMed1998

A novel fungal endo-beta-N-acetylglucosaminidase that specifically acts on plant glycoproteins.

An endo-beta-N-acetylglucosaminidase specific for plant glycoprotein oligosaccharides was purified from the culture fluid of a fungus. The Mr of the purified enzyme was 89,000. This enzyme was stable at pH 5.5-7.0, up to 30 degrees C, and showed the highest activity at pH 6.0. Among sugar chains tested, xylose-containing sugar chains (M3X, M3FX, and M2FX) were the most favored substrates. Oligomannose type (M3, M5, and M9) and hybrid type (GNM3) sugar chains were hydrolyzed much more slowly than xylose-containing sugar chains, and a complex type sugar chain (GN2M3) was not hydrolyzed at all by the enzyme. Moreover, the enzyme released sugar chains from native horseradish peroxidase and stem bromelain, which were not hydrolyzed by other endo-beta-N-acetylglucosaminidases (Endo H, D, and F). The enzyme could transfer the xylose-containing sugar chain from bromelain to DNS-Asn-GlcNAc-Fuc.

Bromelains↗
PubMed1998

Iron chelation by chlorogenic acid as a natural antioxidant.

Chlorogenic acid, a dietary antioxidant, effectively inhibited the iron-induced lipid peroxidation of bovine liver microsomes in a concentration-dependent manner. In the Fenton-type reaction, chlorogenic acid inhibited the production of the hydroxyl radical by iron-EDTA or iron-ADP, while iron plus chlorogenic acid did not generate the hydroxyl radical. The formation of an iron complex with chlorogenic acid was demonstrated by UV/vis absorbance spectroscopic, ESR and 1H-NMR studies. The ferric complex with chlorogenic acid was in the ferric high-spin state near rhombicity, and had no radical scavenging activity. The results indicate that chlorogenic acid prevented the formation of the hydroxyl radical by forming a chelate with iron whose complex cannot catalyze the Fenton-type reaction.

Animals↗
PubMed1998

Acute liver damage with characteristic apoptotic hepatocytes by ingestion of Aplysia kurodai, a sea hare.

A case of acute liver damage by ingestion of Aplysia kurodai, a sea hare is reported. A 40-year-old man, complaining of vomiting and pyrexia after eating a sea hare, was admitted. Laboratory data showed mild liver damage with sustained elevations of aminotransferases. Microscopic findings in the liver biopsy specimen revealed characteristic apoptotic hepatocytes accompanied by mitotic hepatocytes. It is suggested that bioactive substances in the sea hare might induce such apoptosis of hepatocytes in the liver.

Adult↗
PubMed1998

Determination of glycated albumin by enzyme-linked boronate immunoassay (ELBIA).

A new affinity method for quantification of glycated albumin by an enzyme-linked boronate-immunoassay (ELBIA) has been established, based on the interaction between boronic acids and the cis-diols of glycated human serum albumin (HSA) trapped by anti-HSA antibody. To evaluate the ELBIA, we first examined the accuracy of the conventional boronate affinity chromatographic (BAC) method. In the BAC method, 8.1-18.9% of nonglycated albumin calibrator nonspecifically bound to the boronate affinity column, values that were regarded as the column blank. In the modified BAC method, therefore, we substracted the column blank value from the measured glycated albumin value to obtain the true value. Because glycated albumin values measured by ELBIA were exactly the same as reported by the modified BAC method, we suggest that the ELBIA results reflect the real status of albumin glycation. We have also developed a fully automated ELBIA system, allowing multiple, rapid, and precise measurements of glycated albumin.

Boronic Acids↗
PubMed1998

[A case of transethmoidal meningocele showing increased activity of 99mTcHM-PAO at seizure attack].

A case of transethmoidal meningocele presenting seizure attack is reported. A 59-year-old man was admitted to our hospital because of seizure attack. On admission, he was neurologically free without right olfactory dysfunction. T2-weighted image of MRI showed high intensity signal area in right frontal base, and this signal increase herniated into the ethmoidal sinus. Then 3 DCT image clearly showed right frontal base bony defect. After admission, we compared brain activity in this patient during a seizure attack and resting state using SPECT. And we found increased activity in right frontal base using 99mTc HM-PAO. So it was suspected that indicated the focus of the seizure. During the operation a unilateral bony defect and hypoplastic olfactory nerve were observed, but there was no herniated brain tissue. The association of seizure with frontobasal meningoencephalocele is reported only two cases. In one of two cases, it is presumed that reactive gliosis was epileptogenesis. On the other hand, the relationship of the temporal meningoencephalocele to the genesis of temporal lobe seizure is suggested by the extension of gliosis to the amygdalohippocampal lesion. In our case, it is possible that reactive gliosis or scar of the cyst wall may be the focus of seizure. In terms of diagnosis, 3 DCT is useful to identify the bony defect. It makes easy to diagnose the front-basal encephaloceles.

Ethmoid Sinus↗
PubMed1998

Nucleotide and amino acid sequences of the monkey P450 2B gene subfamily.

The nucleotide sequence of a cDNA coding for monkey cytochrome P450 (P450) 2B has been determined. Using antibody against P450 CMLa which had been purified from hepatic microsomes of untreated cynomolgus monkeys, a cDNA clone with 2,275 bp insert (Mac2B) was isolated from a gamma gt11 cDNA library prepared from hepatic mRNA from an untreated rhesus monkey. The cloned insert was sequenced and found to contain an open reading frame coding for a polypeptide of 491 amino acids. The molecular weight calculated from the deduced amino acid sequence was 55,969. The N-terminal 34 amino acids encoded by Mac2B were identical to those determined by Edman degradation analysis of purified cynomolgus monkey P450 CMLa. The nucleotide and the deduced amino acid sequences of Mac2B which is now called CYP2B17 were the most similar to those of human P450 2B6 among the P450 2B subfamily and those sequences of Mac2B were 94% and 90% identical to those of human P450 2B6, respectively.

Amino Acid Sequence↗
PubMed1998

[Influence of light scattering in the opaque lens on the ability to focus--examination utilizing opacified model lenses].

In order to objectively evaluate the relationship between the quality of images which will be reflected on the retina, through opaque lenses and the grade of opacification, model lenses of nuclear cataract and subcapsular cataract were manufactured. The nuclear cataract model lenses were made of polymethylmethacrylate (PMMA) with and without a cut off wavelength below 380 nm. The lens shape was the biconvex intraocular lens (IOL) type and the opacification was achieved by polymerization of both hydrophile and lyophobic monomers. The model of subcapsular opacification was composed of ultraviolet (UV)-cut IOL and a hard contact lens (HCL). The HCL was attached behind the IOL and whitish corpuscles (T1O2, mean diameter of particle = 0.2 micron) were inserted into the gap between the lenses. Utilizing a still camera with 35 mm film, images were photographed through the nuclear opacified model lenses and evaluated. The model of the subcapsular opacified lens was examined by a simulation camera (CCD) in which the lens was held in water. The image quality obtained from the non-UV absorbed nuclear opacification type lens was markedly poor compared with that from the UV absorbed type lens. Although image contrast became worse with increased nuclear opacification, the worsening of image quality was slight in the opacified lens with a 20% reduction of light transmission. It was even possible to recognize photographed subjects through an opacified lens with 60% transmission. Images through the subcapsular opacified model lenses were not influenced by the opacified area in the models with up to 130 cct light scattering intensity at the central part of opacification. Although the study aimed to simply simulate images reflected on the retina through two types of cataractous lenses, the results obtained showed useful objective information concerning images seen through cataractous eyes.

Cataract↗
PubMed1998

Objective evaluation of Papanicolaou staining.

OBJECTIVE: To evaluate the color of cytoplasm stained by Papanicolaou staining quantitatively. STUDY DESIGN: Cytoplasm photographed under the same conditions was measured for spectral reflection by colorimetry, and the color of the cytoplasm was shown by the L*a*b* color specification. RESULTS: This method enabled us to specify the color of cytoplasm, which was classified in light green, eosin and orangeophilic. CONCLUSION: The variation in the color of cytoplasm by different staining methods was quantified and related to the dyes absorbed by the cytoplasm.

Colorimetry↗