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Biomedical subjects

H Otsuka

Publications and source records attributed to H Otsuka.

At least 55 records · Page 3Linked to original sources
PubMed2000

Impact of anatomical difference of the cerebral venous system on microcirculation in a gerbil superior sagittal sinus occlusion model.

Sinus-vein thrombosis (SVT) is known to have a wide spectrum of clinical manifestations, and the formation of venous collateral pathways is considered to be one of the most important factors influencing the individual outcome. Here, we examined the relationship between the anatomical differences in bridging veins and cerebral microcirculation in a gerbil superior sagittal sinus (SSS) occlusion model. In male Mongolian gerbils (n=26), the SSS was ligated close to the confluence sinuum. Four additional animals served as the sham-operated control. Regional cerebral blood flow (rCBF) and haemoglobin oxygen saturation (HbSO2) were assessed by Laser-Doppler flowmetry and a microspectrophotometric method at 36 identical locations in the both hemispheres every 20 minutes for 120 minutes after ligation using a "scanning" technique. Furthermore, we examined change in the diameter of the bridging vein by fluorescence angiography and brain damage by histological investigation after 48 hours. Based on the anatomical findings, the hemispheres were classified into two groups: group A with one bridging vein, n=24/52 sides (46.2%) and group B with more than two bridging veins, n=28/52 sides (53.8%). Significant decreases in rCBF (P<0.05) and rHbSO2 (P<0.05) were seen from 20 minutes after the ligation to the end of the experiment in group A, but not in group B. A detailed analysis of individual cases in changes of local (l) CBF and lHbSO2 revealed three patterns: 1) pattern-1, no change; 2) pattern-2, decrease with following recovery; 3) and pattern-3, decrease without recovery. There were no significant differences in the diameter of the bridging vein and no venous infarction in either groups. The group A frequency, which consisted of pattern-3 (58.3%)>pattern-2 (29. 2%)>pattern-1 (12.5%), was opposite to that of group B, which consisted of pattern-1 (71.4%)>pattern-2 (25.0%)>pattern-3 (3.6%) (P<0.001). Based on the results of this study, the anatomical structure and an opening of the collateral pathways of the venous drainage system are closely related to microcirculatory alterations after venous occlusion. The experimental model is suitable for the study of the pathophysiological mechanism responsible for the high variability of SVT.

Animals↗
PubMed2000

Intra-abdominal metastases in musculoskeletal sarcomas.

This study examined the incidence, histological type, clinical symptoms, and prognosis in patients with intra-abdominal metastases of musculoskeletal sarcomas. The medical records of 505 patients with musculoskeletal sarcomas were reviewed for examples of intra-abdominal metastases. The incidence of intra-abdominal metastases (excluding lung) was: 4% in the liver (20 patients), 1.2% in gastrointestine (6 patients), 0.8% in pancreas (4 patients), and 0.8% on the peritoneal surface (4 patients). Patients with a previous hisory of lung metastases and those with high-grade liposarcoma tended to show metastasis in the intra-abdominal organs. Most patients with liver metastasis had no symptoms. Patients with gastrointestinal metastasis had abdominal pain, anemia, and melena. Patients with pancreatic metastasis had diabetes and jaundice. Six patients underwent surgical treatment, and two of them survived for more than 2 years. Metastases within the abdomen must be considered as a possible site for dissemination of musculoskeletal sarcomas, especially in patients with advanced disease and those with liposarcoma.

Adolescent↗
PubMed2000

Immunization of dogs with a canine herpesvirus vector expressing Neospora caninum surface protein, NcSRS2.

In order to develop a vaccine against Neospora caninum in dogs, we constructed recombinant canine herpesvirus (CHV) expressing N. caninum surface protein, NcSRS2. Indirect immunofluorescence indicated that the antigenic structure of the recombinant NcSRS2 was similar to the authentic parasite protein. The dogs immunised with recombinant virus produced IgG antibody to N. caninum, and their sera recognised the parasite protein on Western blot. The dogs inoculated with recombinant virus showed no clinical symptoms and infectious CHV was not recovered from the dogs, suggesting that recombinant CHV expressing N. caninum proteins may lead to a vaccine against neosporosis in dogs.

Animals↗
PubMed2000

Monoclonal antibody inhibition of Neospora caninum tachyzoite invasion into host cells.

Monoclonal antibodies were produced against Neospora caninum tachyzoites to identify antigens which may play a role during invasion of host cells. Confocal laser microscopy showed that most antigens recognised by the mAb were located on the surface, but one mAb, 1A5, reacted to the apical end of the parasite. Some mAbs, which recognised 70, 42 and 36kDa parasite proteins, significantly inhibited the invasion of the parasite in vitro. The mAbs which recognised 42 and 36kDa parasite protein, reacted with Nc-p43 and Nc-p36 expressed by vaccinia virus and Escherichia coli, respectively. These results suggest that a 70kDa protein, Nc-p43 and Nc-p36 are involved in the invasion of the parasite into host cells.

Animals↗
PubMed2000

Phlorigidosides A-C, iridoid glucosides from Phlomis rigida.

From the aerial parts of Phlomis rigida, three iridoid glucosides, phlorigidoside A (2-O-acetyllamiridoside), B (8-O-acetyl-6-beta-hydroxyipolamide) and C (5-deoxysesamoside), were isolated together with the known iridoid glucosides, shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester, deoxypulcheloside I, lamiridoside, and 6-beta-hydroxyipolamide. The structures of the new compounds were elucidated based on spectral and chemical evidence.

Glucosides↗
PubMed2000

Bovine herpesvirus 1 glycoprotein G is required for viral growth by cell-to-cell infection.

The bovine herpesvirus 1 (BHV-1) US4 gene encodes glycoprotein G (gG), which is conserved in the majority of alphaherpesviruses. In order to identify the role of BHV-1 gG in the viral infection cycle, a gG minus BHV-1 mutant and its gG-positive revertant were constructed and their growth characteristics in Madin-Darby bovine kidney (MDBK) cells were compared. The gG minus mutant formed smaller plaques than the gG-positive BHV-1 in MDBK cells. When a monolayer culture of MDBK cells was infected with BHV-1 at a low multiplicity of infection and overlaid with semi-solid growth medium, under which adsorption of the mature virion released in the medium was inhibited, gG-positive BHV-1 multiplied, while the growth of the gG negative BHV-1 was severely inhibited. These data suggest that BHV-1 gG functions in direct cell-to-cell transmission mechanism of BHV-1 in tissue culture.

Animals↗
PubMed2000

Surface characterization of functionalized polylactide through the coating with heterobifunctional poly(ethylene glycol)/polylactide block copolymers.

An AB-type block copolymer composed of alpha-acetalpoly(ethylene glycol) (PEG) as the hydrophilic segment and polylactide (PLA) as the hydrophobic segment was synthesized and utilized to construct a functionalized PEG layer possessing a reactive aldehyde group at the free end of the tethered PEG chain by simple coating on polylactide substrates. Detailed characterization of the functionalized PEGylated surfaces was done from the physicochemical (contact angle and zeta potential) as well as the biological (protein adsorption) point of view to highlight their potential utility as biofunctional interfaces. The amount of protein adsorption was inversely correlated with the degree of water structuring around the PEG molecules, which facilitates the formation of a strongly bound water film to increase the surface hydration. For these surfaces investigated, the extent of surface hydration was more important in determining the materials biocompatibility rather than the actual PEG molecular weight, as evidenced by an extremely low receding contact angle directly related to the adhesive energy of a water molecule. Furthermore, the contact angle relaxation less than a few minutes proved to be determinant for the receding contact angle and resultant hysteresis, caused by rearrangement of the hydrophilic PEG component. Aldehyde groups were confirmed to be present at the tethered PEG chain end using an electron spin resonance probe and can be derivatized with bioactive molecules with amino or hydrazide functionality. The functionalized PEG layer thus prepared on a biodegradable polylactide surface has both nonfouling and ligand-binding properties and may have promising utility as engineered biomaterials including tissue engineering scaffolds.

Absorption↗
PubMed2000

Phenolic glycosides from the leaves of Alangium platanifolium var. platanifolium.

Chemical investigation of Alangium platanifolium var. platanifolium has resulted in the isolation of nine phenolic glycosides that were identified by means of 1D and 2D NMR experiments. Among them, catechol and salicinol O- and 1-O-beta-D-(6-O-beta-D-apiofuranosyl)glucopyranosides, respectively 1 and 2, and two compounds characterized as adducts of 2, 6-dihydroxybenzoic acid with salicin (plataplatanoside, 3) and 4-hydroxysalicin (4-hydroxyalangifolioside, 4) were determined structurally as new compounds.

Asteraceae↗
PubMed2000

Long-lasting binding of IT-066 to human histamine H2 receptor.

Based on animal models, IT-066, a histamine H2-receptor antagonist, is reported to possess potent and long-lasting antagonisms on histamine H2 receptor (H2R) -mediated effects. However, no reports have been published concerning its interaction with the human H2R. The aim of this study is to characterize its interaction with human H2R. Chinese hamster ovary cell lines stably expressing human H2Rs were obtained. The effects of IT-066, famotidine, and ranitidine on tiotidine binding and histamine-stimulated cAMP production were analyzed. IT-066 inhibited [3H]tiotidine binding and histamine-stimulated cAMP production more potently than famotidine or ranitidine. In addition, preincubation with 10(-5) M IT-066, but not with 10(-5) M famotidine or 10(-4) M ranitidine, had marked inhibitory effects long after extensive washing. Paraformaldehyde fixation of the cells blunted inhibition of [3H]tiotidine binding induced by preincubation with IT-066, but not that by preincubation with famotidine or ranitidine. IT-066 has potent and long-lasting antagonisms on human H2R. At least one of the IT-066 binding sites is not shared by famotidine, ranitidine, or tiotidine and is affected by paraformaldehyde fixation.

Animals↗
PubMed2000

The effect of brain compression under venous circulatory impairment.

It is well known that surgical obliteration of the cerebral veins with additional brain compression by retractors is dangerous. To evaluate the mechanism, we studied the change in cerebral microcirculation and parenchymal damage following brain compression with venous circulatory impairment using a rat model. The animals were divided into the following four groups (each n = 5) (1) a sham-operated control; (2) group A, one cortical vein occlusion; (3) group B, a 30 mmHg compression pressure; and (4) group C, one cortical vein occlusion with 30 mmHg compression. The cortical vein was occluded photochemically. Local cerebral blood flow (l-CBF) in the compressed area was measured by stationary laser-Doppler (LD) flowmetry and regional CBF (r-CBF) in the surrounding area was also measured by LD scanning technique for 120 min. l-CBF in the compressed area decreased significantly in groups B and C. A gradual and significant increase in group B and decrease in group C in r-CBF of the surrounding area were observed. Histologically, more extensive damage was observed in group C than in group A and B. The degree of hypoperfusion of the affected brain correlated well with the subsequent brain damage in the experiments. We demonstrated that, compared with vein occlusion or brain compression alone, the accumulated episode caused severe ischemia, then increased the vulnerability of the rat brain to tissue damage.

Animals↗
PubMed2000

Attachment and penetration properties of bovine herpesvirus 1 recombinants expressing pseudorabies virus glycoproteins gC and gB.

OBJECTIVE: Bovine herpesvirus 1 (BHV-1) has a relatively narrow host cell range in vitro and in vivo when compared to pseudorabies virus (PrV). The aim of this study was to elucidate whether homologous glycoproteins gC and gB from PrV can function in a heterologous BHV-1 background and whether the expression of these PrV glycoproteins influences the in vitro host cell specificity of BHV-1. METHODS: We constructed BHV-1 recombinants in which PrV gC and gB were expressed either individually or in combination, and examined their attachment and penetration properties in permissive Madin-Darby bovine kidney (MDBK), semipermissive hamster lung (HmLu-1) and nonpermissive murine embryo fibroblast (A31) cells. RESULTS: Two BHV-1 recombinants which expressed PrV gC exhibited remarkable competence in virus attachment to cells. The expression of PrV gB improved the virus attachment only a little but penetration, especially into HmLu-1 and A31 cells, was enhanced. CONCLUSIONS: These results indicate that PrV gC and gB can function in a BHV-1 environment and facilitate virus attachment and penetration by BHV-1.

Animals↗
PubMed2000

Isolation of lignan glucosides and neolignan sulfate from the leaves of Glochidion zeylanicum (Gaertn) A. Juss.

Six lignan and neolignan derivatives (1-6) were isolated from the n-BuOH-soluble fraction of a MeOH extract of the leaves of Glochidion zeylanicum. On the basis of spectral data, their structures were elucidated to be (+)-isolarisiresinol 3a-O-beta-glucopyranoside (1), dihydrodehydrodiconiferyl alcohol 4-, 9- and 9'-O-beta-D-glucopyranosides (2-4, respectively), (+)-isolarisiresinol 2a-O-beta-D-glucopyranoside (5), and dihydrodehydrodiconiferyl alcohol 9-O-sulfate (6), and 5 and 6 were new compounds.

Euphorbiaceae↗
PubMed2000

Labdane diterpenoids from Marrubium globosum ssp. globosum.

A new labdane type diterpenoid, marrubiglobosin, was isolated from the aerial parts of Marrubium globosum ssp. globosum together with the known diterpenoids, marrubiin and marrubinone B. The structure of this new compound was elucidated by spectral methods.

Diterpenes↗
PubMed2000

Megastigmane, benzyl and phenethyl alcohol glycosides, and 4,4'-dimethoxy-beta-truxinic acid catalpol diester from the leaves of Premna subscandens MERR.

Extensive isolation work on the n-BuOH-soluble fraction obtained from the leaves of Premna subscandens, collected on Ishigaki island, Okinawa, afforded six compounds. Two were identified as megastigmane glucosides, 7-(3,5-dihydroxy-1,1,5-trimethylcyclohexylidene)-9-methylprop++ +-8-enyl 9-O-beta-D-glucopyranoside and 3-hydroxy-5,6-epoxy-beta-ionol 9-O-beta-D-glucopyranoside. The structures of the remaining four new compounds were elucidated to be a 2'-O-beta-D-apiofuranosyl derivative of 3-hydroxy-5,6-epoxy-beta-ionol 9-O-beta-D-glucopyranoside, named premnaionoside, benzyl alcohol beta-D-(2'-O-beta-D-xylopyranosyl)glucopyranoside, phenethyl alcohol beta-D-(2'-O-beta-D-glucopyranosyl)glucopyranoside, and 4,4'-dimethoxy-beta-truxinic acid catalpol diester by spectroscopic analyses.

Acetylation↗
PubMed2000

Glochidionolactones A-F: butenolide glucosides from leaves of Glochidion zeylanicum (GAERTN) A. JUSS.

From the leaves of Glochidion zeylanicum, six new butenolide glucoside, named glochidionolactones A-F, were isolated along with a known related compound, phyllanthurinolactone. The structures of glochidionolactones A-D and F were elucidated mainly by spectroscopic analyses. The absolute stereochemistry of glochidionolactone E was established by X-ray crystallographic analysis.

Crystallography, X-Ray↗
PubMed2000

Suppression of the proliferation of mouse splenocytes by pseudorabies virus.

Pseudorabies virus (PRV) infection in resistant swine caused immunosuppression which sometimes resulted in secondary infection by other viruses or bacteria. However the mechanism of the immunosuppression is not well understood. In this study, the effect of PRV on the immune system was examined in the mouse model. Splenocytes or lymphocytes prepared from the spleen of BALB/c mice were incubated in vitro with mitogen, and the ability of cells to proliferation was measured. When the cells were incubated with PRV, the ability of cells to proliferate was inhibited, although PRV did not multiply in the lymphocytes. UV-inactivated PRV also suppressed the proliferation of mice splenocyte. This result suggests that the structural component of PRV virion might cause the immunosuppression.

Animals↗