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H Watanabe

Publications and source records attributed to H Watanabe.

At least 37 records · Page 2Linked to original sources
PubMed2006

Development and validation of a PulseNet standardized pulsed-field gel electrophoresis protocol for subtyping of Vibrio cholerae.

PulseNet is a network that utilizes standardized pulsed-field gel electrophoresis (PFGE) protocols with the purpose of conducting laboratory-based surveillance of foodborne pathogens. PulseNet standardized PFGE protocols are subject to rigorous testing during the developmental phase and careful evaluation during a validation process assessing its robustness and reproducibility in different laboratories. Here we describe the development and validation of a rapid PFGE protocol for subtyping Vibrio cholerae for use in PulseNet International activities. While the protocol was derived from the existing PulseNet protocol for Escherichia coli O157, various aspects of this protocol were optimized for use with V. cholerae, most notably a change of the primary and secondary restriction enzyme to SfiI and NotI, respectively, and the use of a two-block electrophoresis program. External validation of this protocol was undertaken through a collaboration between three PulseNet Asia Pacific laboratories (Public Health Laboratory Centre, Hong Kong, National Institute of Infectious Diseases, Japan, and International Center for Diarrhoeal Diseases Research-Bangladesh) and PulseNet USA. Comparison of PFGE patterns generated by each of the participating laboratories demonstrated that the protocol is robust and reproducible.

Bangladesh↗
PubMed2006

Comedolytic effect of topically applied active vitamin D3 analogue on pseudocomedones in the rhino mouse.

BACKGROUND: Retinoids and active vitamin D(3) analogues regulate the proliferation and differentiation of keratinocytes and are effective in the treatment of psoriasis. Retinoids are known to be effective against acne vulgaris through comedolysis. However, the comedolytic effect of active vitamin D(3) analogues has not been reported. OBJECTIVES: To investigate whether maxacalcitol, one of the active vitamin D(3) analogues, has a comedolytic effect by using spontaneously comedogenic rhino mice. METHODS: Rhino mice were treated topically with tretinoin and maxacalcitol once daily for 2 and 4 weeks, respectively. The dermal side of the epidermal sheet was observed to determine the size of the utricle. Haematoxylin and eosin-stained vertical sections were used to measure utricle diameter and density and to evaluate histological changes. RESULTS: Maxacalcitol (25 microg g(-1)) and tretinoin (0.1%) significantly decreased the size and the diameter of the utricle after 1 week of treatment. However, maxacalcitol did not affect the density while tretinoin did have an effect. Histopathologically, maxacalcitol and tretinoin markedly induced epidermal hyperplasia accompanied by a minor accumulation of inflammatory cells in the dermis, with and without hypercornification, respectively. CONCLUSIONS: These results indicate that maxacalcitol has a prominent effect on comedolysis and that its mechanism of action may be different from that of retinoids.

Acne Vulgaris↗
PubMed2006

Robust salivary gland-specific transgene expression in Anopheles stephensi mosquito.

Malaria sporozoites invade the mosquito salivary glands and wait in the salivary duct until the next blood feeding. The mechanisms of the process and molecules involved in the salivary gland invasion remain largely unknown. To establish a robust salivary gland-specific transgene expression in Anopheles stephensi, we obtained a salivary gland-specific promoter for a gene encoding anopheline antiplatelet protein (AAPP). The aapp promoter is a female salivary gland-specific and blood meal-inducible strong promoter. Using this promoter, we generated a transgenic An. stephensi expressing abundant Discosoma sp. red fluorescent protein (DsRed) in the distal-lateral lobes of the glands, where the sporozoites invade preferentially. These results open up the possibilities of elucidating salivary gland-parasite interactions and generating transgenic mosquitoes refractory to parasites.

Animals↗
PubMed2006

Site-specific mutation of the interferon sensitivity-determining region (ISDR) modulates hepatitis C virus replication.

The number of amino acid substitutions in the interferon sensitivity-determining region (ISDR) in the nonstructural 5A (NS5A) gene of hepatitis C virus (HCV) is closely associated with the interferon (IFN) response and viral load. Several HCV replicon-based studies have reported that ISDR sequences had an influence on viral replication in vitro. However, it is unclear as to how different ISDR sequences affect HCV replication. Various clinically observed ISDR sequences were introduced into HCV replicons and their contribution to viral replication was investigated using a colony formation assay and/or a transient replication assay. A mapping study of the ISDR was performed to identify the amino acid positions that critically affect replication. While no colonies were formed in the colony formation assay using HCV replicons with few mutations (0, 1 and 3) in the ISDR, numerous colonies (>200) appeared when using constructs with six mutations. Introduction of various distinct ISDR sequences with multiple mutations resulted in replication enhancement in transient assays. A mapping study identified several specific sites in the ISDR that critically affected replication, including codon 2209 which, in patients, was closely associated with a strong response to IFN. ISDR sequences associated with a clinical IFN response and viral load modulated the replication of HCV replicons, suggesting the importance of the ISDR sequence in HCV infection.

Amino Acid Sequence↗
PubMed2006

Human T-cell responses to oral streptococci in human PBMC-NOD/SCID mice.

We investigated cellular and humoral immune responses to oral biofilm bacteria, including Streptococcus mutans, Streptococcus anginosus, Streptococcus sobrinus, and Streptococcus sanguinis, in NOD/SCID mice immunized with human peripheral blood mononuclear cells (hu-PBMC-NOD/SCID mice) to explore the pathogenicity of each of those organisms in dental and oral inflammatory diseases. hu-PBMC-NOD/SCID mice were immunized by intraperitoneal injections with the whole cells of the streptococci once a week for 3 weeks. FACS analyses were used to determine the percentages of various hu-T cell types, as well as intracellular cytokine production of interleukin-4 and interferon-gamma. Serum IgG and IgM antibody levels in response to the streptococci were also determined by enzyme-linked immunosorbent assay. S. anginosus induced a significant amount of the proinflammatory cytokine interferon-gamma in CD4(+) and CD8(+) T cells in comparison with the other streptococci. However, there was no significant differences between the streptococci in interleukin-4 production by CD4(+) and CD8(+) T cells after inoculation. Further, S. mutans significantly induced human anti-S. mutans IgG, IgG(1), IgG(2), and IgM antibodies in comparison with the other organisms. In conclusion, S. anginosus up-regulated Th1 and Tc1 cells, and S. mutans led to increasing levels of their antibodies, which was associated with the induction of Th2 cells. These results may contribute to a better understanding of human lymphocyte interactions to biofilm bacteria, along with their impact on dental and mucosal inflammatory diseases, as well as endocarditis.

Animals↗
PubMed2006

A time-dependent effect of PDGF-BB on adhesion and growth of cultured fibroblasts to root surfaces.

OBJECTIVE: Platelet-derived growth factor (PDGF-BB) is suggested to be a potent stimulator and a strong mitogenic agent for human periodontal ligament cells (PDL). This study aimed at assessing the effectiveness of PDGF-BB application on periodontally diseased root surfaces through attachment and growth of fibroblast cells. MATERIALS AND METHODS: Fifteen periodontally involved and five healthy teeth were selected, prepared from proximal surfaces and distributed into four groups (10 specimens per group): I: healthy; II: untreated diseased; III: scaling and root planning (SRP); and IV: SRP and PDGF-BB. Each group had three subdivisions (three specimens per group) which were incubated at three different time periods. The remaining specimen for each group was used to examine surface topography. Fibroblasts were pooled on root specimens and incubated. Results were evaluated by using scanning electron microscopy. Repeated cell counting was done within a representative standard area. RESULTS: The best results regarding PDL cell shape and density were obtained at day 3 in all experimental groups, except the diseased group. Although SRP samples showed slightly higher results in numbers of attached fibroblasts than diseased samples, they demonstrated a similar negative effect denoting incompatible root surfaces for fibroblast attachment. SRP plus PDGF-BB and healthy samples showed a comparable positive effect, suggesting a good root surface biocompatibility. Inter-group differences showed no significant differences on day 1, but statistically significant differences were found on both day 3 and day 7 incubation periods favoring groups I and IV over groups II and III. CONCLUSIONS: Platelet-derived growth factor showed a positive effect on adhesion and growth of cultured fibroblasts to periodontally diseased surfaces. Thus, PDGF-BB may have a promising role in clinical periodontics.

Adult↗
PubMed2006

Severe scoliosis associated with Costello syndrome: a case report.

Costello syndrome is characterised by dwarfism, unique cutaneous lesions, a distinct facial gestalt, and mental retardation. There have been no detailed reports of severe spinal deformities requiring surgical treatment as a complication of Costello syndrome. We report a case of a 10-year-old girl with progressive scoliosis associated with Costello syndrome. She underwent anterior release and posterior surgical correction and fusion from T5 to L2 using a third generation hook and rod system plus spinous process wiring. Congenital portal vein deficiency and coagulopathy were other major complications. At 15-month follow-up, the patient had good balance and no evidence of instrumentation failure.

Abnormalities, Multiple↗
PubMed2006

The estrogen-responsive adrenomedullin and receptor-modifying protein 3 gene identified by DNA microarray analysis are directly regulated by estrogen receptor.

Recent studies have revealed that hundreds of genes in the uterus are activated by estrogen. Their expression profiles differ over time and doses and it is not clear whether all these genes are directly regulated by estrogen via the estrogen receptor. To select the genes that may be regulated by estrogen, we treated mice with several doses of estrogen and searched for those genes whose dose-response expression pattern mirrored the uterine growth pattern. Among those genes, we found that the dose-dependent expression of the adrenomedullin (ADM) gene correlated well with the uterotrophic effect of estrogen. ADM expression is induced early after estrogen administration and is restricted to the endometrial stroma. The spatiotemporal gene expression pattern of ADM was similar to that of receptor-modifying protein 3 (RAMP3). RAMP3 is known to modify calcitonin gene-related receptor (CRLR) so that it can then serve as an ADM receptor. Chromatin immunoprecipitation assays indicated that the estrogen receptor binds directly to the ADM promoter region and RAMP3 intron after estrogen administration. It was also shown that neither the ADM nor RAMP3 gene could be activated in estrogen receptor-alpha-null mouse. Although uterine ADM expression has been reported to occur in the myometrium, our observations indicate that estrogen-induced ADM is also expressed in the uterine stroma and that such variable, spatiotemporally regulated ADM expression contributes to a wider range of biological effects than previously expected.

Adrenomedullin↗
PubMed2005

Changes in biochemical parameters after anterior cruciate ligament injury.

We studied the biochemical characteristics of human knees with deficient anterior cruciate ligaments (ACL) and analysed their relationship to the time after ligamentous injury. Thirty-two patients with isolated ACL-injured knees and six healthy volunteers were enrolled. Synovial fluid samples were centrifuged after aspiration during arthroscopic examination, and aliquots of supernatant were frozen and stored at -80 degrees C. The samples were analysed for interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, IL-6, matrix metalloproteinase (MMP)-3, and tissue inhibitor of metalloproteinase (TIMP)-1 using commercially available sandwich enzyme-linked immunosorbent assay. In fluid from ACL-injured knees, the average concentrations of IL-6, MMP-3 and TIMP-1 were highly elevated in comparison with normal controls. There was a statistically significant correlation between the concentrations of MMP-3 and IL-6. The IL-6 and TIMP-1 concentrations were interrelated. The concentration of MMP-3 remained high, independent of the duration since the injury, whereas the TIMP-1 and IL-6 levels decreased. The results suggest that the timing of the treatment of an ACL-injured knee might be of importance.

Adolescent↗
PubMed2005

Portal venous tumor thrombus associated with hepatic metastasis of renal cell carcinoma: case report.

We report a case of liver metastasis of renal cell carcinoma with portal venous tumor thrombus. Abdominal computed tomographic images showed a large hepatic mass that enhanced slightly during arterial phase. Multiple hypoattenuating lesions were seen in the intrahepatic portal venous branches and were traced directly from the mass. The histologic specimen confirmed metastatic liver tumor of renal cell carcinoma with portal venous tumor thrombus.

Adult↗
PubMed2005

Novel approach on the risk assessment of oxidized fats and oils for perspectives of food safety and quality. I. Oxidized fats and oils induces neurotoxicity relating pica behavior and hypoactivity.

Food poisoning caused by deteriorated fat and oil in instant noodles was first reported in Japan approximately 40 years ago. In these cases, many people developed neurotoxic symptoms such as emesis and discomfort. The degree of oxidation of the fat and oil in the instant noodles that induced food poisoning was at least 100 meq/kg in peroxide value (PV). No general toxicity studies with animals, however, have examined the toxicity of fat and oil oxidized to that extent. In this study, pica behavior, a behavior characterized by eating a nonfood material such as kaolin and that relates to the degree of discomfort in animals, and alterations of locomotor activity of rats eating deteriorated fat and oil were measured. The groups fed fat and oil with at least 138.5 meq/kg PV consumed significantly more kaolin compared to the control group. Furthermore, rats that ate deteriorated fat and oil with at least 107.2 meq/kg PV had significantly decreased locomotor activity compared to control rats. These phenomena suggest that oxidized fat and oil with at least 100 meq/kg PV induce neurotoxicity. The toxicity of oxidized fat and oil has only been addressed using general toxicity tests, but the present results reveal the importance of evaluating toxicity by using other measures.

Animals↗
PubMed2005

Relationship between filtration coefficients of microvasculature and levels of atrial natriuretic peptide or echocardiographic measurements.

BACKGROUND/AIMS: Assessing the volume status of hemodialysis (HD) patients and determining their adequate dry weight (DW) present great challenges for physicians involved in HD. In this study the relationship between standardized filtration coefficients of microvasculature (Lpst) and the plasma atrial natriuretic peptide (ANP) levels or echocardiographic measurements (UCGm) were clarified. The aim of this study was to evaluate the possibility of utilizing Lpst as one of the tools for assessing volume status of patients undergoing HD. METHODS: 52 patients on maintenance HD were examined. Lpst was calculated by utilizing continuous measurements of blood volume during HD by means of monitoring changes of hematocrit with CRIT-LINE(TM). Plasma ANP levels were measured shortly after HD. Plasma ANP levels were elevated beyond the normal limit in 32 patients (Hi group) and were within the normal range in the remaining 20 patients (Lo group). UCGm were performed within 1 month prior to the study. Inferior vena cava diameters in quiet expiration (IVCe) were dilated in 21 patients (Hivc group) and were within the normal range in the remaining 31 patients (Livc group). Lpst was compared with plasma ANP level and UCGm. RESULTS: Lpst in Lo group were significantly lower than those in the Hi group (0.83+/-0.19 vs. 2.64+/-2.73 ml/mm Hg/min; p<0.001). Lpst correlated significantly with plasma ANP levels (r=0.613; p<0.001). Lpst in the Livc group were significantly lower than those in the Hivc group (1.33+/-1.61 vs. 2.85+/-2.88 ml/mm Hg/min; p<0.001). Lpst also correlated with IVCe (r=0.630; p<0.001). The receiver operating characteristic (ROC) curves for high plasma ANP level and for dilated IVCe were significant for Lpst. Area under the ROC curve for elevated ANP was 0.909 (95% confidence interval (CI) 0.834-0.985) and for dilated IVCe was 0.833 (95% CI 0.724-0.941). CONCLUSION: We conclude that there exists a significant association between Lpst and plasma ANP levels at the end of a dialysis session. There is a possibility that high plasma ANP levels cause elevation of Lpst. Besides ANP, Lpst significantly correlated with IVCe. These results suggested that Lpst can be utilized as one of the tools for assessing volume status of patients undergoing HD.

Adult↗
PubMed2005

Experimental investigation of geologically produced antineutrinos with KamLAND.

The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.

Journal Article↗
PubMed2005

Amphiphilic telechelic poly(N-isopropylacrylamide) in water: from micelles to gels.

We report the first study of aqueous solutions (0.025 gL(-1) to 46 gL(-1)) of a telechelic poly(N-isopropylacrylamide) with octadecyl termini (C(18)-PNIPAM-C(18), M(w): 37000, 320 NIPAM units, M(w)/ M(n)=1.07) obtained by reversible addition-fragmentation chain transfer (RAFT) free radical polymerization of N-isopropylacrylamide. Static and dynamic light scattering measurements and fluorescence spectroscopy, using 8-anilino-1-naphthalenesulfonic acid (ANS) as probe, yielded the concentration dependence of the size and aggregation number of C(18)-PNIPAM-C(18) micelles in cold ( 20( degrees )C) dilute aqueous solutions. Concentrated solutions ( c>20 gL(-1)) form transient gels exhibiting an oscillatory shear behavior that can be approximated by a single-relaxation Maxwellian model. Aqueous solutions of C(18)-PNIPAM-C(18) undergo a phase transition upon heating to 31.5( degrees )C as determined by microcalorimetry. The heat-induced phase separation of dilute (0.025 gL(-1)) C(18)-PNIPAM-C(18) solutions yields a fluid that is colloidally stable at temperatures higher than 33( degrees )C. The overall results are consistent with a model assuming the formation of flowerlike micelles in the dilute regime and a network of micelles connected by telechelic chains in the concentrated regime.

Journal Article↗
PubMed2005

Dynamics of deuterated polystyrene-protonated butadiene diblock copolymer micelles by neutron spin echo.

We report on neutron spin-echo (NSE) measurements on deuterated styrene-protonated butadiene diblock copolymer micelles in deuterated n-decane to investigate the dynamics of butadiene blocks in the corona. Before the NSE measurements, we performed small-angle neutron-scattering (SANS) measurements on the micelles to evaluate the structure to give a basis for the discussion of the dynamics. In the SANS study, we have estimated the form factor P(Q) in terms of a hard-core-shell model from the direct evaluation without curve-fitting procedure while a more flexible core-shell model with the structure factor S(Q) gives a better fit to the observed data. The observed normalized intermediate scattering function I(Q,t)/I(Q,0) by NSE does not show the collective motions corresponding to the so-called breathing mode but rather single chain motion (Zimm modes) for both the 2 and 20 wt % micelle solutions. The Zimm decay rate Gamma(z) in the micelle solution is slow compared with that in the homopolymer solution. This slowing down is assigned to the effective high concentration in the corona. The differences in Gamma(z) between concentrated solutions and the 20% micellar solution are attributed to end-tethering effect of the corona chains on the core surface. The possible reasons why the breathing mode was not observed in the present micelle system are discussed on the basis of chain density in the corona.

Journal Article↗