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Biomedical subjects

O Suzuki

Publications and source records attributed to O Suzuki.

At least 109 records · Page 6Linked to original sources
PubMed1997

Beta-galactosidase-deficient mouse as an animal model for GM1-gangliosidosis.

GM1-gangliosidosis is a progressive neurological disease in humans caused by deficiency of lysosomal acid beta-galactosidase, which hydrolyses the terminal beta-galactosidic residue from ganglioside GM1 and other glycoconjugates. In this study, we generated a mouse model for GM1-gangliosidosis by gene targeting in embryonic stem cells. The mouse homozygous for the disrupted beta-galactosidase gene showed beta-galactosidase deficiency, presented with progressive spastic diplegia, and died of emaciation at 7-10 months of age. Pathologically, PAS-positive intracytoplasmic storage was observed in neuronal cells of various areas in the brain. Biochemical analysis revealed a marked accumulation of ganglioside GM1 and asialo GM1 in brain tissue. This animal model will be useful for pathogenetic analysis and therapeutic trial of human GM1-gangliosidosis.

Animals↗
PubMed1997

Simple analysis of diphenylmethane antihistaminics and their analogues in bodily fluids by headspace solid-phase microextraction-capillary gas chromatography.

Thirteen antihistaminic drugs and their analogues are tested for their extraction by headspace solid-phase microextraction from human whole blood and urine. Their determination is made by using capillary gas chromatography with flame ionization detection. Relatively high recoveries are obtained for terodiline, diphenhydramine, diphenylpyraline, and orphenadrine in urine; but the recoveries in blood extracts are 4-51 times lower than those in urine extracts for all drugs. Benactyzine and piperilate are not suited for the extraction method. The calibration curves are drawn for four drugs spiked to whole blood and for eleven drugs spiked to urine; excellent linearity is confirmed for the drugs. The detection limits for the drugs are 76-473 ng/mL in blood and 13-186 ng/mL in urine. Diphenhydramine is determined for whole blood obtained from a male subject who had received oral administration of 30 mg diphenhydramine-HCl 150 min before the sampling; the concentrations of the drug are 0.12 and 1.22 micrograms/mL for blood and urine, respectively.

Adult↗
PubMed1997

Detection of tricyclic antidepressants in whole blood by headspace solid-phase microextraction and capillary gas chromatography.

A simple method for the extraction of four tricyclic antidepressants from whole blood by headspace solid-phase microextraction (SPME) is presented. The whole blood samples contain four drugs (amitriptyline, chlorimipramine, imipramine, and trimipramine) and are heated at 100 degrees C in a septum-capped vial in the presence of distilled water and NaOH solution; a polydimethylsiloxane-coated SPME fiber is exposed to the headspace of the vial to allow adsorption of the drugs before capillary gas chromatography (GC) with flame-ionization detection. The headspace SPME-GC produces intense peaks for each drug with very little background noise. Recoveries of the four drugs by the present method are 5.3-12.9%. The calibration curves for the drugs show linearity in the range of 31-1000 ng/0.5 mL. The detection limits of each drug are 16-25 ng/0.5 mL. Imipramine is detectable from rat blood 5 h after oral administration of imipramine (500 mg/kg body weight); the concentration is 1.44 +/- 0.209 micrograms/mL.

Amitriptyline↗
PubMed1997

Multinucleated giant cells recruited by implantation of octacalcium phosphate (OCP) in rat bone marrow share ultrastructural characteristics with osteoclasts.

The ultrastructural characteristics of multinucleated giant cells (MNGCs) on octacalcium phosphate (OCP) and hydroxyapatite (HA) were investigated in comparison with those of osteoclasts, when the synthetic OCP and HA were implanted in rat bone marrow. The morphological difference in the MNGCs were shown between OCP and HA implants in 2 weeks after implantation. The MNGC on the implanted OCP (i-OCP) developed the ruffled border-like structure and the clear zone-like structure. The i-OCP was frayed where it was in contact with the ruffled border-like structure. The MNGC on the implanted HA (i-HA) developed the clear zone-like structure, whereas no ruffled border was seen. The surface of i-HA associated with the MNGC was smooth and not frayed. Bone formed directly on the OCP or HA implants. The interface between the i-OCP and bone matrix interdigitated, whereas that between the i-HA and bone matrix was comparatively smooth. The present study suggested that the i-OCP could be resorbed by the MNGCs which share some ultrastructural characteristics with osteoclasts.

Animals↗
PubMed1997

Identification of T-cell epitope sequences on an important mite antigen.

BACKGROUND: T-cell epitopes on Der 1 and Der 2 groups, the major mite allergens, have been intensively analysed, while those on the other important allergens remain to be elucidated. We have cloned four cDNAs coding for important mite allergens on the basis of frequency and capacity of IgE binding. Stimulatory action of glutathione S-transferase-fused Mag1 on lymphocytes from mite-allergic patients was relatively high among them. OBJECTIVE: To identify T-cell epitopes on Mag1, we studied the stimulating activity of truncated Mag1 proteins and synthetic peptides on proliferative response of lymphocytes from mite antigen-immunized mice and mite-sensitive patients. METHODS: Truncated Mag1 proteins were expressed as a fusion protein with beta-galactosidase in Escherichia coli pop2136 carrying a variety of deleted Mag1 inserts. Murine T-cell epitope regions were estimated by the truncated antigen-induced lymphocyte proliferation assay. Overlapping peptides covering the whole sequence of the presumed T-cell epitope regions were synthesized to identify the epitope core sequences using murine and human Mag1-specific T-cell lines. RESULTS: Amino acid range 56-70 on Mag1 molecule showed remarkable stimulatory action on murine T cells, while amino acid ranges 51-65 and 86-100 had potent stimulatory activity on human T cells. CONCLUSIONS: These results suggest that Mag1 is a valuable antigen suitable for studies on T-cell responses and T-cell epitopes in mice and humans.

Animals↗
PubMed1997

Case report: haemorrhagic colitis associated with royal jelly intake.

The case report of a 53-year-old woman with abdominal pain and bloody diarrhoea is described. Prior to the onset of symptoms the patient had taken royal jelly for 25 days. Colonoscopy revealed that the mucosa was haemorrhagic and oedematous throughout the 20 cm long sigmoid colon. Histopathologically, mucosal haemorrhage, oedema, and infiltration of inflammatory cells were observed. Transmission electron microscopic examination revealed platelet aggregation in 30% of capillaries in the mucosal lesions. The drug-induced lymphocyte stimulation test was slightly positive for royal jelly (847 c.p.m., SI = 147%) compared with the control (576 c.p.m.). The patient's signs and symptoms disappeared within a few days after the initiation of conservative therapy, and the colonic lesions disappeared after 2 weeks of this therapy. This is the first reported case of haemorrhagic colitis associated with royal jelly intake.

Colitis↗
PubMed1997

Nonfatal suicidal intoxication by clozapine.

CASE REPORT: A rare case of clozapine intoxication of a 23-year-old woman, who intended suicide by its overdose, but recovered under medical treatments, is presented. METHOD: Gas chromatography/mass spectrometry and gas chromatography with nitrogen phosphorus detection were employed for its identification and quantitation, respectively. RESULTS: Clozapine serum concentration reached 3.62 micrograms/mL 3 h after ingestion. The urine concentration 32 h after ingestion was 4.28 micrograms/mL.

Adult↗
PubMed1997

Localised thrombus in the distal aortic arch: its aetiology analysed by three-dimensional mould model of the thoracic aorta.

Isolated thrombus of the thoracic aorta without aneurysmal change or dissection is a relatively rare event. A case presenting with aortic thrombus and successive distal embolism is reported herein and the aetiology of the thrombus of the distal aortic arch is analysed by a three dimensional aortic model. A 61-year-old man suffered acute ischaemia in his right leg on January 26, 1994. Enhanced computed tomography (CT) showed a localized thrombus in the distal aortic arch expanding towards the descending aorta, and partial infarction of the left kidney and the spleen. Angiography demonstrated abrupt occlusion of the right superficial femoral artery. Immediate anticoagulation with heparin and coumadin was administered, and the thrombus in the aorta disappeared following 1 month of this medical treatment, leaving the renal and splenic infarction unchanged. The unresolved occlusion of the superficial femoral artery and the popliteal artery was treated with a bypass from the right superficial femoral artery to the peroneal artery using a reversed saphenous vein graft. The mould model of the thoracic aorta was reconstructed from CT, and the thrombus was found to be at the most distal and medial site of the lesser curvature of the aortic arch. This specific location is referred mostly as the site for thrombus formation in the literature. The case is reported briefly and the risk of this specific region of the thoracic aorta for thrombus formation is discussed using this mold model.

Angiography↗
PubMed1997

DNA labeling reagent containing carbodiimide.

We have synthesized a number of fluorescent compounds having a carbodiimide function and tested if it can be used to label DNA. They all reacted well with DNA in a very short time. Some of them showed different fluorescent characteristics when they bound to DNA such as band shift or change in fluorescent intensity.

Carbodiimides↗
PubMed1996

Effects of the 7 21 Robertsonian translocation on fertilization rates and preimplantation development of bovine oocytes in vitro.

A study was conducted to investigate the effect of the 7/21 Robertsonian translocation on fertilization and subsequent development of bovine oocytes matured in vitro. Semen from Japanese Black bulls, 2 with a normal karyotype (Bulls A and B) and 2 that were heterozygous for the 7/21 translocation (Bulls C and D), was used in this study. In vitro matured bovine oocytes were inseminated with frozen-thawed sperm capacitated with heparin. After insemination, oocytes were cultured at 38.5 degrees C on a monolayer of cumulus cells in TCM-199 supplemented with 5% superovulated cow serum and 0.5 mM sodium pyruvate in an atmosphere of 2% CO2 in air. Cleavage rate was evaluated at 54 h after insemination, and development of embryos to the blastocyst stage was observed 7 to 10 d post insemination. There was no difference in the fertilization rate among the 4 bulls. Although the cleavage rate of oocytes inseminated with semen from Bull C (heterozygote) was lower (P < 0.05) than that obtained with semen from Bull B (normal), the blastocyst formation rate did not differ among the 4 bulls. These results indicate that the 7/21 Robertsonian translocation had no effect on the fertilization and blastocyst formation rates of bovine in vitro-matured oocytes.

Journal Article↗
PubMed1996

In vitro fertilization and microinsemination with round spermatids for propagation of nephrotic genes in mice.

The ICGN is an inbred strain of mice with a hereditary nephrotic syndrome of an unknown cause. The disease progresses to renal failure, resulting in the deterioration of the systemic condition and in a drastic reduction of reproductive capacity. The present study was undertaken to determine if in vitro fertilization (IVF) and microinsemination using round spermatids could ameliorate the reduced fertility of ICGN mice. Mature oocytes (9.4 +/- 1.1 per mouse) were obtained from PMSG/hCG-primed females 2 to 5 mo of age. When spermatozoa from males aged 3 to 4 mo was used for IVF, a high fertilization rate (82.6%) was achieved and a high rate of embryos developed into blastocysts (92.6%). When spermatozoa from males aged 5 to 7 mo was used, the rates of fertilization and development to blastocysts were significantly lower (63.9 and 47.1%, respectively; P < 0.001). However, the production rate of offspring after embryo transfer was satisfactory irrespective of the age of males (59.1%). When males older than 9 mo were used, no fertilization was achieved due to the very poor motility of the spermatozoa. Microinsemination techniques with round spermatids (electrofusion and intracytoplasmic injection) resulted in the production of normal offspring from the older males, including one azoospermic case. These findings indicate that a conventional IVF technique and microinsemination using round spermatids can be used for propagating mutant genes which cause poor reproductive ability in mice.

Journal Article↗
PubMed1996

Simple and sensitive detection of phencyclidine in body fluids by gas chromatography with surface ionization detection.

Phencyclidine (PCP) can be detected in body fluids with very high sensitivity by gas chromatography (GC) with surface ionization detection (SID) using pethidine as internal standard. PCP was extracted with Sep-Pak C18 cartridges from whole blood and urine samples, which gave clean extracts. The calibration curve for spiked whole blood was linear in the range 1.25-20 ng/ml. The detection limit of PCP was approximately 15 pg on-column (0.75 ng/ml sample), which was much lower than by GC-nitrogen phosphorus detection. The recovery of PCP and pethidine from spiked whole blood or urine samples was above 85%. This method seems very useful for the determination of PCP in forensic and clinical toxicology.

Body Fluids↗
PubMed1996

Mouse oocytes injected with cryopreserved round spermatids can develop into normal offspring.

PURPOSE: This study was performed to determine whether frozen-thawed mouse round spermatids can fertilize oocytes and contribute to normal embryo development. METHODS: Freshly collected mouse testicular cells were frozen in PBS containing 7.5% glycerol and 7.5% fetal bovine serum. After thawing and removal of the cryoprotectants, round spermatids were selected and injected individually into mature oocytes which had been previously activated with Sr(2+)-containing Ca(2+)-free medium. RESULTS: After thawing, 75-85% of testicular cells were alive. About 90% of the oocytes were fertilized by intracytoplasmic injection of frozen-thawed round spermatids; 11% (17/150) of embryos transferred to foster mothers developed into normal offspring. CONCLUSIONS: Mouse round spermatids can be cryopreserved for production of normal offspring.

Animals↗
PubMed1996

Effect of dietary paraquat on a rat mutant unable to synthesize ascorbic acid.

To obtain some insight into the toxicity of paraquat (PQ) in humans, PQ dichloride at 250 ppm in the diet was administered to both normal (NO) rats and ODS-od/od (OD) rats which are unable to synthesize ascorbic acid (AsA). Firstly, OD rats and NO rats treated with PQ were compared with untreated NO rats (CO). Only OD rats displayed several symptoms of PQ poisoning such as anorexia, hypokinesia, diarrhea, epistaxis, tremor and their pili became rough about 9 days after. Their cysteine proteinase inhibitor level in plasma and lung increased to 2- and 6-fold, respectively, of CO. In contrast, NO rats treated with PQ resembled CO rats, and their cysteine proteinase inhibitor levels were unchanged until 11 days. After this period they began to display symptoms. Secondly, OD rats fed with different amounts of AsA were compared. Excess AsA delayed the onset of symptoms by only 1 day. Thirdly, the day of onset of symptoms was found to be influenced with the weight of rats.

Animals↗
PubMed1996

Initiation of alveolar ridge augmentation in the rat mandible by subperiosteal implantation of octacalcium phosphate.

The study was designed to investigate the process of bone formation caused by implantation of octacalcium phosphate as well as stability of the bone formed at the alveolar ridge. Synthetic octacalcium phosphate was implanted into a subperiosteal pocket in the rat mandible. Bone formation at the alveolar ridge was examined radiographically and histologically between 1 and 48 week(s) after implantation. Radiopacity of the octacalcium phosphate implant became obvious in week 2. Osteogenesis was initiated from the bone surface near the implantation site and multinucleated giant cells appeared on the implanted octacalcium phosphate in week 1. More apposition of new bone was observed on the implanted octacalcium phosphate in week 2 or later. Some implants were directly enclosed by newly formed bone and no cellular component was seen between the implant and the bone matrix. Many octacalcium phosphate implants were enclosed by bone, whereas the augmented ridge was not seen radiographically in week 24 or later. If its persistence can be improved, octacalcium phosphate could be used to augment atrophic alveolar ridges.

Alveolar Process↗
PubMed1996

Development in vitro of preimplantation embryos from 55 mouse strains.

Mouse pronuclear embryos were obtained by in vitro fertilization with oocytes of 55 strains of immature females by gonadotrophin-induced ovulation and epididymal sperm of Slc:ICR strain. The number of oocytes ovulated with hormones (5.3-49.4 oocytes per head; average, 22.6), rates of in vitro fertilization (12.2-95.3%; average, 70.7%) and subsequent preimplantation development in Whitten's medium (WM) varied greatly among strains. F1 hybrids developed significantly better than other strains of mice and outbred animals did not develop as well as inbred animals. Within inbred mice, coat colour had no significant effect. In addition, the observation of preimplantation development in WM supplemented with ethylenediamine tetraacetic acid (EDTA) showed that the beneficial effect of the chelator was not universal to mouse embryos; EDTA had a good effect on ICR and PW/aSlc embryos but not on AKR or ddY embryos. The results indicate that strain differences should be considered when interpreting reproductive experiments using mouse embryos.

Analysis of Variance↗
PubMed1996

Microvascular disturbances in the colonic mucosa in antibiotic-associated haemorrhagic colitis: involvement of platelet aggregation.

An ultrastructural study of the colonic mucosa was performed in four patients with antibiotic-associated haemorrhagic colitis and new findings are reported. Colonoscopy was performed and biopsy specimens were obtained within 24 h of the onset of bloody diarrhoea. Colonoscopy demonstrated diffuse oedematous and haemorrhagic mucosa with erosions and white coat. Light microscopy revealed mucosal haemorrhage and inflammatory cell infiltration. Ultrastructurally, platelet aggregation was frequently present in the lumina of colonic mucosal capillaries, causing engorgement of red blood cells in adjacent microvessels. Mild to severe damage was observed in capillary endothelial cells, including discontinuity of basement membranes, gaps between endothelial cells and the destruction of capillaries. There was no evidence of microvascular spasm. In conclusion, our findings suggest that antibiotics directly or indirectly cause microcirculatory disturbances, which result in tissue damage and haemorrhage, in the colonic mucosa.

Adult↗