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Biomedical subjects

J Yasuda

Publications and source records attributed to J Yasuda.

At least 19 recordsLinked to original sources
PubMed2003

Latent HIV-1 reactivation in transgenic mice requires cell cycle -dependent demethylation of CREB/ATF sites in the LTR.

OBJECTIVE: We previously produced a line of transgenic mice that carried the HIV-1 genome deficient in the gene. Although the HIV-1 genome in the lymphocytes was dormant under normal physiological conditions, it could be reactivated by lipopolysaccharide (LPS) administration via induction of interleukin-1alpha/beta and tumour necrosis factor-alpha. In this report, we analysed further the reactivation mechanism of the latent HIV-1 using this transgenic mouse model. DESIGN: and methods: Possible involvement of CpG methylation in HIV-1 latency was examined by treating transgenic lymphocytes with a demethylating agent, 5'-azacytidine. CpG methylation in the HIV-1 long terminal repeat (LTR) was analysed using the bisulfite genomic sequencing method. As previous studies suggested that CpG demethylation depended on the cell cycle progression, we analysed the relation between cell cycle progression and LPS-induced reactivation of HIV-1 by labelling lymphocytes with an intracellular fluorescein, carboxyfluorescein diacetate succinimidyl ester. RESULTS: We found that 5'-azacytidine enhanced HIV-1 expression ninefold compared to treatment with LPS alone. Furthermore, HIV-1 p24 induction by LPS was observed only in cells that had undergone cell division, while induction was prevented in cells in which cell cycle progression was blocked either by mimosine, aphidicolin, or nocodazole. LPS-induced HIV-1 reactivation was associated with demethylation of two CpG sites located in the CREB/ATF binding sites in the HIV-1 LTR in a cell cycle-dependent manner. CONCLUSIONS: These observations indicate that cell cycle progression-dependent demethylation of the CREB/ATF sites in the LTR is crucial for the reactivation of latent HIV-1 genome in transgenic mice.

Activating Transcription Factors↗
PubMed2003

Inhibition of arthritis by systemic administration of endostatin in passive murine collagen induced arthritis.

OBJECTIVE: To investigate the arthritis inhibiting effect of endostatin, known to have potent antiangiogenic activity, systemically given to animal models of rheumatoid arthritis (RA). METHODS: Four kinds of monoclonal anti-type II collagen antibody followed by lipopolysaccharide (LPS) three days later were given to 6 week old, female Balb/c mice to induce arthritis. Three groups of mice received 0.2 mg/kg/day, 2 mg/kg/day, and 10 mg/kg/day of endostatin, respectively, whereas a control group received phosphate buffered saline (PBS). Endostatin or PBS was given for 13 days, starting before the development of arthritis. Arthritis was evaluated by arthritis scores and hind paw thicknesses. Mice were killed for histological examination on the 22nd day after the administration of monoclonal anti-type II collagen antibody. RESULTS: Arthritis developed within three days after LPS administration in both the control and endostatin treatment groups. No difference in the development rate of arthritis was noted between the control and endostatin treatment groups. Arthritis scores remained significantly lower in the endostatin 10 mg/kg/day group than in the control group. Hind paw thicknesses also remained significantly smaller in the endostatin 10 mg/kg/day group than in the control group. Histopathological examination showed that synovial thickening and subchondral bone erosion improved more in the endostatin treatment groups than in the control group. CONCLUSION: The systemic administration of endostatin had an arthritis inhibiting effect in RA animal models. Endostatin inhibited, in particular, pannus formation and bone destruction.

Analysis of Variance↗
PubMed2003

The prevalence of bovine herpesvirus-1 in traditional cattle in Southern Province, Zambia.

A study was conducted to determine the prevalence of bovine herpesvirus-1 (BHV-1), which causes infectious bovine rhinotracheitis, in cattle destined for market in Southern Province, Zambia. A total of 116 nasal secretion samples were tested using the direct fluorescent antibody test, while blood samples from the same cattle were examined by a commercial enzyme-linked immunosorbent assay kit. The prevalence of the BHV-1 antigens in cattle was 23.28% (27/116), while the mean prevalence of the BHV-1 antibodies was 48.28% (56/116). This study showed that cattle in transit to markets could easily spread the virus, which was reactivated by the stress of trekking for long distances under unfavourable conditions, to the other cattle with which they came into contact. Thus, these transit cattle posed a serious threat to other bovines. Systems of cattle trading where cattle must be transported a long wayto market should be reviewed by the authorities to minimise the conditions that may exacerbate the spread of infection.

Animals↗
PubMed2002

Rhabdomyosarcoma (botryoid sarcoma) of the urinary bladder in a Maltese.

A urinary bladder tumour was diagnosed in a two-year-old female Maltese with haematuria and pollakiuria on the basis of ultrasonography and pneumocystography findings. The mass was resected, and the bladder was preserved at surgery. Histological and immunohistochemical examination confirmed the tumour to be a rhabdomyosarcoma, which has rarely been reported in small breeds of dog. There was no recurrence of the tumour at the original site in the urinary bladder two months later, when the dog died due to metastasis to the liver. This is believed to be the first report of bladder rhabdomyosarcoma in a Maltese.

Animals↗
PubMed2001

T cell apoptosis causes peripheral T cell depletion in mice transgenic for the HIV-1 vpr gene.

Vpr, an accessory protein of HIV, is known to affect viral replication as well as cell growth, differentiation, and apoptosis in vitro. To investigate its pathogenicity in vivo, we have produced mice transgenic for the HIV-1 vpr gene with the CD4 enhancer/promoter. Interestingly, apoptotic death of T lymphocytes was enhanced in those mice, causing marked reduction of T cells in lymphatic organs and peripheral blood. Involvement of Bcl-x, Bax, and Caspase-1, but not of the Fas-Fas ligand system, was suggested in the apoptotic processes. These observations suggest that Vpr is involved in the pathogenesis of T cell depletion in HIV-infected people.

Animals↗
PubMed2001

Localization of interferon regulatory factor-1 in human endometrium throughout the menstrual cycle.

OBJECTIVE: To determine the expression and localization of IRF-1 in human endometrium throughout the menstrual cycle. DESIGN: A comparative study. SETTING: Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine. PATIENTS: Thirty-eight women aged 33 to 46 years, with regular menstrual cycles and nonpathological endometrium, undergoing hysterectomy. INTERVENTION(S): Endometrial tissues were obtained from operative samples. MAIN OUTCOME MEASURE(S): Expression of IRF-1 mRNA throughout the menstrual cycle was investigated using semiquantitative reverse transcription-polymerase chain reaction. Localization of IRF-1 protein was determined using immunohistochemistry. RESULT(S): IRF-1 mRNA was expressed in the human endometrium at each phase of the menstrual cycle. The immunoreactivity for IRF-1 was observed in the extranuclear compartment of the surface and glandular epithelial cells, both during the proliferative and secretory phases, as well as in the gland secretion during the secretory phase. In contrast, stromal cells were nearly unstained. CONCLUSION(S): IRF-1 was localized in the human endometrium, implying that this nuclear protein plays some role other than as a transcription factor.

Adult↗
PubMed2001

[A questionnaire survey on the theory of postoperative infection prophylaxis in gynecology].

A questionnaire survey on the theory of postoperative infection prophylaxis was conducted to obtain the consensus on perioperative antimicrobial use among gynecologists in Japan in the period from April to July 2000. Fifty-six of the 83 gynecologists replied, and the following consensus was obtained. An antimicrobial prophylaxis (AMP) agent should be chosen based on their efficacy against the pathogens expected to be contaminants, such as Staphylococcus spp., Escherichia coli and Bacteroides fragilis group. Use an AMP agent that archives a bactericidal concentrations in both the serum and operating site. Use an AMP agent that has little unfavourable side effects. The newer agents should be considered as a therapeutics for postoperative infections. The therapeutic antimicrobial agents having no cross-resistance to the AMP agents should be used, if postoperative infection is suspected or developed. The most commonly used agent for clean operations are cefazolin (CEZ), followed by cefotiam (CTM) and cefmetazole (CMZ). The most commonly used agent for clean-contaminated operations where low grade level of bacterial invasion expected is CTM, followed by CEZ and CMZ, where as operations where mild grade level of bacterial invasion expected is flomxef (FMOX), followed by CTM and other cephalosporins.

Anti-Bacterial Agents↗
PubMed2001

Design and synthesis of carboxylate inhibitors for matrix metalloproteinases.

A series of carboxylate compounds were prepared from N(alpha)-substituted 2,3-diaminopropionic acid and were tested for efficacy as matrix metalloproteinase (MMP) inhibitors. During modeling of the initial compound 10a, we utilized three-dimensional structure modeling software (InsightII/Discover Ver. 2.98). Some of the prepared carboxylate derivatives, such as carbamate compounds (12c,d, 22) and sulfonamide compounds (14b,c), proved to be effective MMP-1 inhibitors (with IC50 values of a 10(-6) M order), depending on the substituent at the N(alpha)-position of 2,3-diaminopropionic acid. Some of them were also evaluated for inhibition of stromelysin-1 (MMP-3), and the sulfonamide compound 14c exceeded the lead compound 5b in its MMP-3 inhibitory potency. For the carbamate compounds, we investigated the minimum molecular size at which the MMP-1 inhibitory potency was maintained, and found that this was P3-P1' compound 10b.

Carboxylic Acids↗
PubMed2001

An investigation of heavy metal exposure and risks to wildlife in the Kafue flats of Zambia.

Exposure and ecological risks to heavy metals (copper, zinc, manganese, iron) at Lochnivar and Blue Lagoon National Parks in wildlife dependent on the Kafue river contaminated with mining waste was evaluated. Samples included water, fish, grasses and Kafue Lechwe (Kobus leche kafuensis) liver. At both parks copper ranged from 0.03-0.04 mg/l; 3.0-6.0 mg/kg; 11.0-44.0 mg/kg; trace -199.0 mg/kg; while zinc was 0.01 mg/l; 32.0-82.0 mg/kg; 15.0-21.0 mg/kg; and 52.0-138.0 mg/kg; in water, fish, grasses and lechwe, respectively. Manganese ranges were 0.15-0.16 mg/l; 7.0-18.0 mg/kg; 51.0-145.0 mg/kg; and 40.0-53.0 mg/kg while iron ranges were 0.13-0.14 mg/l; 26.0-134.0 mg/kg; 1766.0-1797.0 mg/kg; and 131.0-856.0 mg/kg; in water, fish, grasses and lechwe, respectively. Levels in all samples except water were high indicating potential for adverse effects.

Animals↗
PubMed2001

[Therapy-related myeloid leukemia following platinum-based chemotherapy for ovarian cancer].

A 40-year-old woman, who had suffered from AML (M1) in 1983, developed ovarian cancer (stage IIIc) in December 1996 after long-term remission. She underwent surgical resection of the cancer, 10 courses of standard chemotherapy and tandem PBSCT (total dose: CBDCA 6,750 mg, CDDP 200 mg, CPA 16,000 mg, THP-ADR 450 mg). After receiving the last course of chemotherapy in June 1998, she was referred to our hospital in September 1998 because of pancytopenia. Laboratory findings showed pancytopenia with 34% leukemic cells, which were positive for alpha NBE and negative for POX and CAE. Surface-marker analysis of the leukemic cells showed positivity for CD11c, CD33, CD56, and DR, and chromosome analysis revealed 47, XX, +8. The patient was diagnosed as having AML (M5a), and received induction therapy consisting of IDR and Ara-C, which led to complete remission. As she had not received etoposide, this case was thought to have been therapy-related leukemia due to the platinum agents used for treating the ovarian cancer.

Adult↗
PubMed2000

Lipopolysaccharide-induced HIV-1 expression in transgenic mice is mediated by tumor necrosis factor-alpha and interleukin-1, but not by interferon-gamma nor interleukin-6.

BACKGROUND: As serum HIV-1 load correlates well with the prognosis of the disease, it is suggested that the viral load is one of the major determinants of the disease progression of AIDS. Accordingly, HIV-1 activation mechanisms were extensively studied in vitro, and involvement of cytokines including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, IL-6 and interferon (IFN)-gamma has been suggested in this process. However, so far the roles of these cytokines in the HIV-1 expression in vivo have not been well elucidated because of the lack of appropriate animal disease models. OBJECTIVE: To elucidate the roles of cytokines in HIV-1 activation in vivo. DESIGN AND METHODS: Transgenic mice carrying a defective HIV-1 genome were used as a model for HIV-1 carriers. In order to examine the possible involvement of cytokines in HIV-1 expression, TNF-alpha-, IL-1-, IL-6- and IFN-gamma-deficient HIV-1 transgenic mice, were produced and HIV-1 expression was analyzed after activation with bacterial lipopolysaccharides (LPS). RESULTS: HIV-1 expression in the transgenic mouse spleen was activated 10- to 20-fold by LPS, and the serum p24 Gag protein levels reached 400 pg/ml, which is nearly equal to the levels that occur in AIDS patients. However, this augmentation was suppressed by 60% in TNF-alpha-deficient mice and by 40% in IL-1alpha/beta-deficient mice. In contrast, no suppression was observed in either IL-6-, IFN-gamma-, IL-1alpha, or IL-1beta-deficient mice. CONCLUSIONS: Results suggest that TNF-alpha and IL-1 play important roles in HIV-1 gene activation and selective suppression of these cytokines could improve clinical prognosis and potentially slow progression of the disease.

Animals↗
PubMed2000

Role of matrix protein in the type D retrovirus replication cycle: importance of the arginine residue at position 55.

We previously reported that a mutant of Mason-Pfizer monkey virus (M-PMV), which has an amino acid substitution in the matrix (MA) protein at position 55, MA-R55W, showed altered viral morphogenesis, reduced glycoprotein incorporation, and loss of infectivity. In this report, we show that two additional amino acid substitutions at this site in MA, R55F and R55Y, also result in similar altered morphogenesis, Env incorporation, and infectivity, demonstrating that these changes are not specific for the substitution of tryptophan in place of arginine 55. Attempts to isolate second site infectious revertants from cells transfected with the R55W mutant genome resulted only in the recovery of infectious viruses in which the codon at position 55 had reverted to one encoding arginine. In contrast, no revertants were obtained from the phenylalanine and tyrosine mutants in which three nucleotide changes had been engineered into the arginine codon. These results confirm that the arginine residue at position 55 is critical for intracellular targeting of M-PMV Gag molecules and support the concept that as part of a cytoplasmic transport retention signal R55 interacts with cellular trafficking components rather than other regions of Gag.

Amino Acid Substitution↗
PubMed2000

Suppressive effects of dominant negative ras mutant N116Y on transformed phenotypes of human bladder cancer cells.

To investigate the suppressive effect of dominant negative H-ras mutant N116Y on transformed phenotypes, we established two N116Y ras mutant stable transfectant clones (C5, C13) of human bladder cancer cell line, UMUC-2. These N116Y ras mutant transfectants, especially the C5 cells, showed a dramatic change of cellular morphology and significantly reduced growth in soft agar compared to their control. Furthermore, phosphorylation of the Jun NH2-terminal kinase (JNK) was significantly decreased in these transfectants compared to the control. These results suggest that the N116Y-induced suppression of transformed phenotypes in UMUC-2 cells is associated with inhibition of JNK phosphorylation.

Cell Transformation, Neoplastic↗
PubMed2000

Amplotyping of microdissected, methanol-fixed lung carcinoma by arbitrarily primed polymerase chain reaction.

The arbitrarily primed polymerase chain reaction (AP-PCR) was used to detect somatic genetic alterations in lung carcinomas. DNA fingerprints generated by a single arbitrary primer were compared between normal and tumor tissues of the same individuals. We adapted the technique to the use of tissue fixed with methanol, which allowed the analysis of small areas of tissue by microdissection. This improvement of the fingerprinting technique permitted the study of tumors at early stages of progression. Loss of sequences from chromosome 7 was detected in 41.7% of adenocarcinomas and from chromosome 22 in 84.6% of small-cell carcinomas. Gains of sequences from chromosomes 1, 8 and 13 were detected in more than 40% of adenocarcinomas and in chromosome 2 in 63.3% of squamous-cell carcinomas. Our results indicate that allelic imbalances at these chromosomal regions are common genetic abnormalities in lung carcinomas. Loss of sequences from chromosome 22q13.3, found in 11 of 13 small-cell carcinomas, were confirmed by microsatellite PCR analysis. We show that the use of our improved AP-PCR fingerprinting permits the detection of both losses and gains of novel chromosomal regions early during lung cancer development. Our results indicate that early-stage tumors tend to have more allelic imbalances than relatively advanced tumors, suggesting a high tumor genetic heterogeneity in the early stages of lung tumor progression.

Adenocarcinoma↗
PubMed2000

Detection of amplification of a chromosomal fragment at 6p21 including the cyclin D3 gene in a glioblastoma cell line by arbitrarily primed polymerase chain reaction.

DNA from 10 human glioma cell lines was analyzed by arbitrarily primed polymerase chain reaction. By fingerprinting of the DNA fragments obtained, the presence of fragment Qx with an abnormal signal was detected in one of the glioblastoma cell lines, CCF-STTG1. The nucleotide sequence of this fragment of 387 base pairs showed no homology with any known sequences. Southern-blot analysis using Qx as a probe revealed that the abnormal signal was caused by amplification of DNA by about 50-fold. By analysis of radiation hybrid panels, the fragment was shown to be derived from a chromosomal region on 6p21. The cyclin D3 (ccnd3) gene and an EST locus, H40682, both of which were located in this region, were amplified by about 50-fold in this cell line. Two other loci, R75654 and M78872, flanking the Qx, CCND3 and H40682 loci, were not amplified, suggesting that the size of the amplicon was less than 62 cR. Since over-expression of the ccnd3 gene, but not the H40682 locus, was detected in the cell line CCF-STTG1, the increased amounts of cyclin D3 caused by gene amplification could be involved in the development and/or progression of this glioblastoma.

Blotting, Northern↗