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Biomedical subjects

C Ishida

Publications and source records attributed to C Ishida.

At least 19 recordsLinked to original sources
PubMed2001

Phosphatidylglycerol participates in syncytium formation induced by HTLV type 1-bearing cells.

We previously reported that 71-kDa heat shock cognate protein (HSC70) was expressed on the cell surface of human T cell lymphotropic virus type 1 (HTLV-1)-susceptible cells and that HSC70, beta-actin, and a lipid-like component on the target cell membrane participated in syncytium formation by HTLV-1. We have now identified this lipid-like component to be palmitoyl (16:0)-oleoyl (18:1)-phosphatidylglycerol (POPG), using preparative thin-layer chromatographic fractionation and tandem mass spectrometric analysis. In the syncytium formation assay, exogenously added PG inhibited cell-to-cell transmission of HTLV-1 in a dose-dependent manner. Other phospholipids showed less (PE) or no effect (PC, PS, PI, PA, lysoPC, lysoPE, and CL). Binding experiments showed that PG interacted with three synthetic peptides, gp46--111, gp46--197, and gp21--400, which correspond to regions Lys111--Asp138 and Asp197--Leu216 on the gp46 surface glycoprotein, and to region Cys400--Leu429 on the gp21 transmembrane glycoprotein, respectively, as well as with intact gp46 and gp21 proteins of HTLV-1. On the other hand, HSC70 and beta-actin interacted with gp46--197 and gp46, not with gp46--111. However, the eluate from an affinity column coupled with gp46--111 contained not only PG but also HSC70 and beta-actin, despite the lack of direct interaction between gp46--111 and these proteins. In the in vitro binding assay, HSC70 showed interaction with both PG and beta-actin, while there was no evidence of any interaction between PG and beta-actin. These results suggest that HSC70 molecules on target cell surface interact with both PG in lipid bilayers and intracellular beta-actin and that these three cellular components form a receptor complex that plays a critical role in syncytium formation induced by HTLV-1-bearing cells.

Actins↗
PubMed2001

[Bartonella henselae infection in domestic cat and dog fleas].

We studied on the infection of domestic cat and dog fleas with Bartonella henselae by polymerase chain reaction (PCR). A total of 62 fleas (36 Ctenocephalidis felis from cats, 24 C. felis from dogs and 2 Ctenocephalidis canis from dogs), stored in 70% ethanol, were analyzed by PCR for B. henselae specific DNA. Of the 62 fleas, C. felis from cats and dogs were positive for B. henselae specific DNA in 12 of the 36 (33.3%) and in 5 of the 24 (20.8%), respectively, and C. canis from dogs was positive in 2 of the 2 (100%). Our results demonstrated that pet fleas were infected with B. henselae, and suggest that flea transmission of B. henselae between cats or dogs may occur, and direct transmission of B. henselae from pet fleas to human may cause cat scratch disease.

Animals↗
PubMed2001

[Serological cross-reaction among Bartonella henselae, Chlamydia pneumoniae and Coxiella burnetii by indirect fluorescence antibody method].

We studied the serological cross-reactions among Bartonella henselae, Chlamydia pneumoniae and Coxiella burnetii by indirect fluorescence antibody (IFA) method, using sera from 8 patients with cat scratch disease (CSD), 13 patients with C. pneumoniae infection and 12 patients with acute Q fever. B. henselae IgG antibody was negative in 13 patients with C. pneumoniae infection, and was positive in 3 (titers being 1:64) of 12 patients with Q fever, whereas B. henselae IgM antibody was negative in all the patients with C. pneumoniae infection or Q fever. C. burnetii IgG antibody was removed by absorption of these 3 sera with C. burnetii antigens, whereas B. henselae IgG antibody did not change. C. pneumoniae IgG antibody was positive in 3 (titers being 1:125 in two, 1:32 in one) of 8 patients with CSD. Both C. pneumoniae and B. henselae IgG antibody titers were significantly reduced by absorption of these 3 sera with B. henselae antigens. C. burnetii IgG or IgM antibodies were negative in all patients with CSD. In conclusion, no serological cross-reaction between B. henselae and C. burnetii was observed. On the other hand. B. henselae IgG antibody cross-reacted to C. pneumoniae antigens, whereas C. pneumoniae IgG antibody did not cross-react to B. henselae antigens. Our findings suggest that determination of B. henselae IgG or IgM antibodies were not influenced by C. pneumoniae and C. burnetii antigens.

Bartonella henselae↗
PubMed2001

Detection of serum thermolabile beta-2 macroglycoprotein (Hakata antigen) by enzyme-linked immunosorbent assay using polysaccharide produced by Aerococcus viridans.

Although a serum thermolabile beta-2 macroglycoprotein (TMG) may play a role in host defense as a lectin, little is known of its related physiological functions, mainly due to a lack of appropriate methods for tracing the functions of TMG. We identified a polysaccharide from Aerococcus viridans, PSA, which reacts with TMG, and based on this finding, we developed an enzyme-linked immunosorbent assay to trace the functions of TMG. Using ethanol precipitation and DEAE-Sepharose and Sephacryl S-400 column chromatographies, we isolated PSA from cultured medium of A. viridans, and it exhibited specific binding against TMG in blood samples. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the isolated PSA showed ladder bands that implied the existence of repeating units composed of D-glucose, N-acetyl-D-glucosamine, D-mannose, and D-xylose, as confirmed by gas chromatography-mass spectrometry. SDS-PAGE and immunochemical analysis, using rabbit anti-TMG antibody, showed that PSA specifically binds solely to intact serum TMG but not to TMG heated at 56 degrees C for 30 min, a condition under which antigenicity is lost. TMG in serum samples bound to PSA in a dose-dependent manner, and this binding was clearly suppressed by addition of PSA. These observations indicate that PSA is a useful adsorbent to TMG and can be used to develop appropriate methods for tracing the functions of TMG.

Antibodies, Bacterial↗
PubMed2001

[Comparison of the newly developed MYCOACID system with mycobacteria growth indicator tube (MGIT) and newly developed 2% Ogawa medium (S) for recovery of mycobacteria in clinical specimens].

The detection rate of mycobacteria from patients' specimens and the time required to get positive culture were compared among newly developed MYCOACID SYSTEM, MGIT, Ogawa K medium and 2% Ogawa medium (S). A total of 249 sputum samples taken from patients were used as the study subjects and 124 kinds of mycobacteria were isolated. For 135 cases clinically diagnosed as pulmonary tuberculosis, the detection rate was 44.4% for MYCOACID, 47.4% for MGIT and 38.5% for Ogawa K medium, showing that there are no significant differences in the detection rate between MYCOACID and MGIT, and MYCOACID and Ogawa K medium but the differences was significant between MGIT and Ogawa K medium (p = 0.02). The mean days needed for detection of Mycobacterium tuberculosis complex was 12.3 days for MYCOACID, 13.4 days for MGIT, and 26.8 days for Ogawa K medium, indicating significant differences in the time to get positive culture between Ogawa K medium and either of both liquid media (p < 0.001). Furthermore, 2% Ogawa medium (S) was used only for the detection of mycobacteria among previously untreated tuberculosis and there were no significant differences in the detection rate between 2% Ogawa medium (S) and either of both liquid media. The time to get positive culture for 2% Ogawa medium (S) was 18.2 days, which was longer than that for either of liquid media, MYCOACID and MGIT, but it was significantly shorter (7.9 days) than that for Ogawa K medium (p = 0.003). These results demonstrate that the liquid culture systems both MYCOACID and MGIT were very useful for the detection of mycobacteria compared with Ogawa K medium.

Bacteriological Techniques↗
PubMed2001

[Epilepsy].

Explore the source record for details and available documents.

Adolescent↗
PubMed2000

[Primary factors for a transfer to home care].

The subjects for this study were patients in remission discharged from the Palliative Care Unit (PCU) between January 1 and December 31, 1999. There were 72 patients, which represents 22% of all discharged patients during the same period. The objective of this study was to clarify nursing intervention in the transition from admission to the PCU to the transfer to home care and primary factors in this process. The study of medical records and inquiries made of primary nurses served as methods for this. Unless patients or their families have the desire to shift to home care, the transfer is difficult. However, as a result of information provisioning and coordination through nursing intervention concerning the home care support system, the transfer to home care was possible for 22% of all discharged patients. Primary factors in the transfer to home care are that: 1. patients have the desire to shift to home care; 2. patients' families accept home care; 3. symptoms are controlled to the level sought by the patients; 4. patient's clinical process can be observed continuously by the PCU outpatient clinic; and 5. there are adequate preparations to receive patients in an emergency.

Caregivers↗
PubMed1999

A thermophilic cyanobacterium Synechococcus elongatus has three different Class I prenyltransferase genes.

Prenyltransferases (prenyl diphosphate synthases), which are a broad group of enzymes that catalyze the consecutive condensation of homoallylic diphosphate of isopentenyl diphosphates (IPP, C5) with allylic diphosphates to synthesize prenyl diphosphates of various chain lengths, have highly conserved regions in their amino acid sequences. Based on the above information, three prenyltransferase homologue genes were cloned from a thermophilic cyanobacterium, Synechococcus elongatus. Through analyses of the reaction products of the enzymes encoded by these genes, it was revealed that one encodes a thermolabile geranylgeranyl (C20) diphosphate synthase, another encodes a farnesyl (C15) diphosphate synthase whose optimal reaction temperature is 60 degrees C, and the third one encodes a prenyltransferase whose optimal reaction temperature is 75 degrees C. The last enzyme could catalyze the synthesis of five prenyl diphosphates of farnesyl, geranylgeranyl, geranylfarnesyl (C25), hexaprenyl (C30), and heptaprenyl (C35) diphosphates from dimethylallyl (C5) diphosphate, geranyl (C10) diphosphate, or farnesyl diphosphate as the allylic substrates. The product specificity of this novel kind of enzyme varied according to the ratio of the allylic and homoallylic substrates. The situations of these three S. elongatus enzymes in a phylogenetic tree of prenyltransferases are discussed in comparison with a mesophilic cyanobacterium of Synechocystis PCC6803, whose complete genome has been reported by Kaneko et al. (1996).

Amino Acid Sequence↗
PubMed1999

Methanesulfonyl fluoride (MSF): a double-blind, placebo-controlled study of safety and efficacy in the treatment of senile dementia of the Alzheimer type.

The purpose of the present study was to evaluate methanesulfonyl fluoride (MSF), a very long-acting CNS-selective acetylcholinesterase (AChE) inhibitor, as a palliative treatment for senile dementia of the Alzheimer type (SDAT). In experiment I, MSF (0.03-0.18 mg/kg) was administered orally to 10 normal volunteers to measure toxicity and establish dose/response function in erythrocyte AChE. MSF produced a dose-response function of %inhibition = (40)(Log10[MSF mg/kg] + 51.7) with no toxicity at these doses. Experiment II was a 16-week double-blind, placebo-controlled study of the safety and efficacy of MSF in doses of up to 0.18 mg/kg given three times per week in 5 men and 10 women (60-82 years), with Mini-Mental State Examination (MMSE) scores of 9-24, who had SDAT. MSF produced a mean of 89.5% inhibition of erythrocyte AChE in patients and improved cognitive performance as measured by the MMSE, Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-COG), Global Deterioration Scale, and the Clinical Interview Based Impression of Change (CIBIC). Most of the improvement on the ADAS-COG was maintained 8 weeks after ending MSF. No patients left the study because of drug-related adverse events and there were no toxic effects. MSF may be a safe and effective palliative treatment for SDAT and further clinical trials in larger groups of patients are warranted.

Acetylcholinesterase↗
PubMed1999

Gene cloning and overexpression of a geranylgeranyl diphosphate synthase of an extremely thermophilic bacterium, Thermus thermophilus.

A geranylgeranyl diphosphate (GGPP) synthase gene of an extremely thermophilic bacterium, Thermus thermophilus, was cloned and sequenced. T. thermophilus GGPP synthase, overexpressed in Escherichia coli cells as a glutathione S-transferase fusion protein, was purified and characterized. The fusion protein, retaining thermostability, formed a homodimer, and showed higher specific activity than did a partially purified thermostable enzyme previously reported. Optimal reaction conditions and kinetic parameters were also examined. The deduced amino acid sequence indicated that T. thermophilus GGPP synthase was excluded from the group of bacterial type GGPP synthases and lacked the insertion amino acid residues in the first aspartate-rich motif as do archaeal and eukaryotic short-chain prenyltransferases.

Alkyl and Aryl Transferases↗
PubMed1998

Dual action of CD30 antigen: anti-CD30 antibody induced apoptosis and interleukin-8 secretion in Ki-1 lymphoma cells.

CD30 is a member of the tumor necrosis factor superfamily. In this study, we examined the effect of four anti-CD30 (aCD30) antibodies (Abs) on CD30-positive anaplastic large cell lymphoma-derived cell line, Ki-JK. The aCD30 Abs suppressed [3H]thymidine (TdR) incorporation. With a TdT mediated dUTP-biotin nick end labeling method, apoptosis was detected in Ki-JK cells at day 5 after the addition of aCD30 Ab to the culture. Genistein, an inhibitor of protein tyrosine kinase, had no effect on aCD30 Ab-induced apoptosis. The aCD30 Ab simultaneously induced interleukin-8 (IL-8) secretion in the Ki-JK cells. In culture of the Ki-JK cells with aCD30 Ab for 5 days, the IL-8 concentration of the cell free-supernatant increased to 240 +/- 16 pg/ml, though the concentration was < 12.5 pg/ml without aCD30 Ab. In combination with aCD30 Ab, genistein decreased the concentration of IL-8 in day 5 supernatants. Although, doxorubicin and herbimycin-A suppressed [3H]TdR incorporation and induced apoptosis in the Ki-JK cells, they did not induce IL-8 secretion. Only aCD30 Ab-induced apoptosis was accompanied by IL-8 secretion. IL-8 mRNA was not detected in the Ki-JK cells by reverse transcription-polymerase chain reaction assay. IL-8 mRNA was detected 5 days after adding aCD30 Ab to the culture.

Antibodies↗
PubMed1998

71-kilodalton heat shock cognate protein acts as a cellular receptor for syncytium formation induced by human T-cell lymphotropic virus type 1.

We previously reported that the region corresponding to amino acids 197 to 216 of the gp46 surface glycoprotein (gp46-197) served as a binding domain for the interaction between gp46 and trypsin-sensitive membrane components of the target cell, leading to syncytium formation induced by human T-cell lymphotropic virus type 1 (HTLV-1)-bearing cells. Our new evidence shows that the 71-kDa heat shock cognate protein (HSC70) acts as a cellular receptor for syncytium formation. Using affinity chromatography with the peptide gp46-197, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, we isolated three components (bands A, B, and C) from MOLT-4 cell lysate which exhibited specific interactions with gp46 and inhibitory activities for syncytium formation induced by HTLV-1-bearing cells. Band A and B components were identified as HSC70 and beta-actin, respectively, through amino acid sequencing by tandem mass spectrometry and immunostaining with specific monoclonal antibodies. Band C is likely to be a nonprotein component, because full activity for syncytium formation was seen after extensive trypsin digestion. Anti-HSC70 monoclonal antibody clearly blocked syncytium formation in a coculture of HTLV-1-bearing cells and indicator cells, whereas no inhibition was seen with anti-beta-actin monoclonal antibody. Furthermore, flow cytometric analysis indicated that anti-HSC70 antibody reacted with MOLT-4 cells. Thus, we propose that HSC70 expressed on the target cell surface acts as a cellular acceptor to gp46 exposed on the HTLV-1-infected cell for syncytium formation, thereby leading to cell-to-cell transmission of HTLV-1.

Amino Acid Sequence↗
PubMed1998

All-trans retinoic acid modulates Fas antigen expression and affects cell proliferation and apoptosis in combination with anti-Fas monoclonal antibody in the human myeloma cell line, U266B1.

All-trans retinoic acid (ATRA) is a vitamin A derivative that induces the differentiation of myeloid leukemia cells in vitro and in vivo. Several investigators have recently reported that ATRA downregulates the production of interleukin-6 (IL-6) and the expression of IL-6 receptor (IL-6R) and also inhibits the proliferation of myeloma cells. It has also been reported that myeloma cells express Fas antigen, and in some of these cells apoptosis was induced by treatment with anti-Fas monoclonal antibody (mAb). In the present study, we demonstrated that ATRA increased Fas expression in the human myeloma cell line, U266B1. We observed that both apoptosis induction and growth inhibition were enhanced in cells exposed to a combination of anti-Fas mAb and ATRA compared with cells exposed to either treatment alone. We also examined whether ATRA modulated bcl-2, an anti-apoptosis protein, in U266B1 cells. Flow cytometry analysis revealed that the mean fluorescence intensity of bcl-2 protein was slightly decreased in cells treated with ATRA. These results indicate that in U266B1 cells, combined treatment with anti-Fas mAb and ATRA enhances the induction of apoptosis by modulating the expression of Fas and bcl-2 by ATRA.

Antibodies, Monoclonal↗
PubMed1997

Functional cloning of a cDNA encoding Mei2-like protein from Arabidopsis thaliana using a fission yeast pheromone receptor deficient mutant.

To isolate Arabidopsis cDNAs that encode signal transducers and components involved in the regulation of meiosis, a trans-complementation analysis was performed using a Schizosaccharomyces pombe meiosis-defective mutant in which the genes for pheromone receptors were disabled. One cDNA obtained in this screening encodes a polypeptide, named AML1, that shows significant similarity to S. pombe Mei2 protein and has three putative RNA-recognition motifs like as Mei2. Mei2 is involved in the regulation of meiosis in fission yeast. Northern blot analysis showed that the AML1 gene is expressed in each organ. The possible functions of AML1 are discussed.

Amino Acid Sequence↗
PubMed1997

Trypsin-sensitive and -resistant components in human T-cell membranes required for syncytium formation by human T-cell lymphotropic virus type 1-bearing cells.

Human T-cell lymphotropic virus type 1 (HTLV-1) envelope proteins play an important role in viral entry into target cells. In a syncytium formation assay consisting of a coculture of HTLV-1-bearing cells and target cells, mature gp46 and gp21 proteins each inhibited syncytium formation induced by HTLV-1-bearing cells. Experiments with 125I-labeled proteins showed that 125I-gp46 bound specifically with MOLT-4 target cells even in the presence of large amounts of gp21, whereas 125I-gp21 binding to target cells was completely blocked in the presence of large amounts of gp46. These observations suggest that HTLV-1 envelope proteins in syncytium formation interact with at least two components, which are located close to each other on the cell membrane. We isolated two components from MOLT-4 cell lysate, using Sepharose 4B columns coupled with peptides corresponding to amino acids 197 to 216 and 400 to 429, respectively, of the envelope protein. One is a trypsin digestion-sensitive component of approximately 34 to 35 kDa, which interacts specifically with gp46. The other is a nonprotein component, which interacts with gp21. This component was destroyed by sodium periodate oxidation and was partitioned into the methanol-chloroform phase. These observations suggest that these two components play an important role in HTLV-1 entry into target cells via membrane fusion.

Cell Membrane↗