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Biomedical subjects

O Suzuki

Publications and source records attributed to O Suzuki.

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

A curious autopsy case of accidental carbon monoxide poisoning in a motor vehicle.

A 26-year-old man was found dead in his car. All doors and windows were locked inside. The ignition key was in the "on" position; but the engine was not running and the fuel tank was empty. His post-mortem lividity was cherry-pink, and marked congestion was observed in the lungs and brain macroscopically. Massive intracardiac blood containing a small amount of cruor was found in the heart. In histological examination of the heart, partial disarrangement or necrosis was found in the myocardium. The liver cells showed derangement and degenerative changes, with focal lymphocyte infiltration in the portal regions, although they were not severe. The chemical tests showed that the blood concentration of carboxyhemoglobin was 46.6%. Stimulants were also detected from his blood and urine; the concentrations of methamphetamine and amphetamine were 3.25 and 0.84 microg/ml, respectively, for his cardiac blood. Therefore, it seemed reasonable to judge that the cause of his death was carbon monoxide poisoning; the cardiomyopathy and the presence of stimulants in blood might facilitate his death. Upon careful investigation of his car, it was disclosed that exhaust gas, leaked from small holes of the exhaust pipe due to rust-through, invaded the interior through four holes on the floor of the car during parking with the engine being on for the purpose of air-conditioning of the interior. It is very common to commit suicide by introducing exhaust gas into an interior of a closed motor car, but the present accidental case of carbon monoxide poisoning in a car seems rare and worthwhile reporting.

Journal Article↗
PubMed2000

Purification and characterization of sea squirt alpha-N-acetylgalactosaminidase.

Sea squirt alpha-N-acetylgalactosaminidase was purified to homogeneity. Its molecular weight was estimated to be approximately 160,000 by gel filtration and 40,000 by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing condition. The chromatographic and electrophoretic behaviors indicated that the enzyme was composed of four subunits. The optimum pH of the enzyme reaction was about 4.0 at 37 degrees C, while the enzyme was stable in the range of pH 5.0 to 6.0 during 4 h preincubation at 37 degrees C. Although the enzyme (0.1 unit) was stable at 0 degrees C for 30 min in the presence of 7.5 mM metal ions (Al3+, Ba2+, Ca2+, K+, Mn2+, Pb2+, Sr2+, and Zn2+), almost 40% of the enzyme activity was lost in the presence of Cu2+, Hg2+, monoiodoacetic acid, and EDTA. The enzyme hydrolyzed aryl N-acetyl-alpha-D-galactosaminide as well as GalNAcalpha1(-->4GalNAcalpha1-->)n 4GalNAc-p-aminobenzoic acid ethyl ester (ABEE) (n = 1-4), but GalNAcalpha1-->4GalNAc-ABEE only scarcely. Furthermore, an allergenic pentasaccharitol ABEE derivative, GalNAcalpha1-->2Fucalpha1-->3(GalNAcbeta1-->4) GlcNAcbeta1-->2(3-acetoamido-3-deoxy)L-threose-ABEE, the minimum structural unit for the sea squirt allergenicity was hydrolyzed to 95 mol% for 72 h incubation with the enzyme. The enzyme could be utilized as a powerful tool for the structural analyses of the carbohydrate epitopes of the sea squirt allergen molecules.

Journal Article↗
PubMed2000

Recent advances in the microinsemination of laboratory animals.

Microinsemination techniques were applied to laboratory animals, including mice, Mongolian gerbils, mastomys, guinea pigs and cynomolgus monkeys. After micro-insemination with spermatozoa or round spermatids, their oocytes were successfully fertilized and subsequently developed into 4-cells to blastocysts, depending on species. The efficiencies of microinsemination techniques for producing fertilized oocytes were comparable with, or superior to those of IVF in these species.

Animals↗
PubMed2000

Increase in production of ascorbate radical in tissues of rat treated with paraquat.

The production of ascorbate radical (A*-) was investigated in tissues of rats intoxicated with paraquat (PQ) to know the protective role of antioxidant ascorbate (AH-) in tissues. The electron spin resonance (ESR) method is applied to observe A*-. To eliminate increased biosynthesis of ascorbic acid (AH2) by PQ intoxication, ODS rats were chosen and fed with or without 250 ppm PQ in the diet. The radical A*- was detected only in the lung and spleen homogenates of both intoxicated and control rats at the beginning of ESR measurement. The radical levels of intoxicated rat lung and spleen were increased rapidly to twice the initial level after 3 h and decreased to 0.2-0.6 times the initial level after 24 h, whereas those of control rats were increased slowly to 1.1 times the initial level after 4 h and decreased slowly to 0.7 times the initial level after 24 h at 4 degrees C. In other organs such as liver, kidney, heart and testis, A*- was not detected initially but detected afterwards. Higher A*- level was observed in the intoxicated rat liver than the control but no appreciable differences of A*- levels were observed between the intoxicated kidney, heart and testis and the respective controls. In the intoxicated rat lung the concentration of AH2 is only half but that of A*- is twice as high as that of the control. Larger amounts of A*- produced in the intoxicated rats decayed more quickly than those in the control rats. The simple addition of PQ to the control organ enhanced neither A*- production nor A*- quenching. These facts suggest that the tissues damaged by PQ require larger amounts of AH- to detoxicate harmful oxidants, resulting in concomitant production of A*-.

Animals↗
PubMed2000

Production of male cloned mice from fresh, cultured, and cryopreserved immature Sertoli cells.

Although it is generally accepted that relatively high efficiencies of somatic cell cloning in mammals can be achieved by using donor cells from the female reproductive system (e.g., cumulus/granulosa, oviduct, and mammary gland cells), there is little information on the possibility of using male-specific somatic cells as donor cells. In this study we injected the nucleus of immature mouse Sertoli cells isolated from the testes of newborn (Days 3-10) males into enucleated mature oocytes in order to examine the ability of their nuclei to support embryonic development. After activation of the oocytes that had received the freshly recovered immature Sertoli cells, some developed into the morula/blastocyst stage, depending on the age of the donor cells (22.0-37.4%). When transferred into pseudopregnant females, 7 (3.3%, 7 of 215) developed into normal pups at term. Nuclear transfer of immature Sertoli cells after 1 wk in culture also produced normal pups after embryo transfer (3.1%, 2 of 65). Even after cryopreservation in a conventional cryoprotectant solution, their ability as donor cells was maintained, as demonstrated by the birth of cloned young (6.7%, 7 of 105). Immature Sertoli cells transfected with green fluorescent protein gene also supported embryo development into morulae/blastocysts, which showed specific fluorescence. This study demonstrates that immature Sertoli cells, male-specific somatic cells, are potential donors for somatic cell cloning.

Animals↗
PubMed2000

A simple semisolid subtraction method using carbodiimide-coated microplates.

In this article, we develop a novel subtraction method using carbodiimide-bound microplates. This method utilizes the high affinity of carbodiimides for both single- and double-stranded nucleic acids. Carbodiimide-mediated end-attachment of driver RNA to microplates allows semisolid phase hybridization between driver RNA and target cDNA, and ensures easy removal of RNA/cDNA hybrids composed of the genes commonly expressed in driver and target. As a result, the target-specific genes are left unhybridized and enriched in the hybridization supernatant. We define the optimal conditions for the method as a target/driver RNA ratio of 1:10 and a period of hybridization of 24 h. There are at least three major advantages with the present method: (1) The entire procedure, which consists of two steps, is very simple; (2) hybridization efficiency can be monitored before further processing of the samples; and (3) rare transcripts can be effectively enriched. This method may be a powerful tool to isolate the genes specifically expressed in particular cell or tissue types, and is easily applicable to many studies in molecular biology and genetics. Isolation of polyploid megakaryocyte-specific genes is shown as an example.

Blotting, Northern↗
PubMed2000

Development of embryos in superovulated guinea pigs following active immunization against the inhibin alpha-subunit.

Embryo recovery and subsequent embryonic development from guinea pigs treated with or without inhibin vaccines were compared to determine the effect of active immunization against the inhibin alpha-subunit. Twenty female guinea pigs of the Hartley strain were injected 3 times either with 1 ml inhibin vaccine (recombinant ovine inhibin a-subunit in oil emulsion: 50 microg/ml, inhibin-immunized group), or 1 ml placebo (saline in oil emulsion; control group) at 4 week intervals. After one estrous cycle following the last injection, females were naturally mated and embryos were collected at 11:00 hr of day 6 of pregnancy (Day 1: sperm in the vaginal smear) for culture in vitro. Active immunization increased the number of corpora lutea (12.6+/-3.0 vs. 4.6+/-0.2, P<0.05), recovered embryos (9.8+/-1.9 vs. 3.6+/-0.4, P<0.01) and normal embryos (7.8+/-1.4 vs. 3.6+/-0.4, P<0.05), although estrous cycle length was not affected (P>0.05). During subsequent 8 day culture in vitro, most of the recovered embryos formed trophoblast outgrowth; 100% (14/14) and 88.2% (15/17) in control and immunized groups, respectively. High levels of inhibin antibody titers were sustained in the inhibin-immunized guinea pigs at least for 5 months after the last injection while no antibody titer was detected in the control animals. These results indicate that active immunization against the inhibin a-subunit is a long-acting and efficient method to induce superovulation with normal embryonic development in the guinea pig.

Animals↗
PubMed2000

Myxoid leiomyosarcoma of the uterus.

A 70-year-old, menopausal Japanese woman with large uterine tumor underwent total hysterectomy. Microscopic examination revealed a myxoid leiomyosarcoma with 5 to 6 mitoses/10 high power field (HPF). Immunohistochemically, the tumor cells reacted with desmin, suggesting that they are derived from uterine smooth muscle cells. The patient was treated with the combination chemotherapy consisting of cisplatin, adriamycin and cyclophosphamide, and she has been free from disease for 70 months after the operation.

Aged↗
PubMed2000

Rupture of infected pseudoaneurysms in patients with implantable ports for intra-arterial infusion chemotherapy.

Intra-arterial hepatic chemotherapy via implantable reservoirs is being used increasingly. In our department, five patients have undergone emergency surgery since 1991 because of rupture of an infected pseudo-aneurysm at the site of entry of the catheter. Surgical procedures included removal of the catheter and the reservoir, and closure of the affected artery with or without reconstruction. Of these patients, three (60%) died from uncontrollable sepsis. The poor prognosis emphasizes the need, in patients with carcinoma, for strict aseptic technique and hemostasis at the time of catheter placement, and for careful device maintenance.

Adult↗
PubMed2000

[Prognostic factors of hepatocellular carcinoma: analysis by the proportional hazard model].

Five hundred fifty patients hospitalized to our hospital during 1990 to 1999 were studied. Subjects consisted of 413 males and 102 females and mean age was 62.1 years. Association with HBV infection, HCV infection and both infection was 11.1%, 78.4% and 2.5% respectively. According to the criteria based in Liver Cancer Study of Japan, 5 year survival rate in clinical stage I, II, III was 42.3%, 38.8% and 17.5%. Tumor morphology was nodular type in 78.9%, massive type in 9.1% and diffuse type in 10.5% of cases. Portal tumor thrombus and distal metastasis were observed in 19.9% and 6.3% of all cases. The 1-, 3- and 5-year survival rate in patients received any therapy was 80.8%, 44.6% and 28.7%, respectively. Analysis by the proportional hazard model showed that HBV infection, advanced clinical stage, multiple tumors, a tumor diameter in excess of 5 cm and AFP positivity were shown as significant factors on poor prognosis.

Carcinoma, Hepatocellular↗
PubMed2000

[From medicolegal toxicology to forensic toxicology].

The importance of forensic toxicology has been increasing until now, because of the increasing numbers of toxic substances and poisoning incidents. In Japan, a special translational word "houi-chudoku-gaku" has been used for the forensic toxicology especially in the field of legal medicine. The Japanese word, however, does not seem appropriate for translation of forensic toxicology, because it covers medicine, pharmacy and police sciences interdisciplinary. In 1980, Emeritus Prof. Hidetoshi Yoshimura created an appropriate word "hochudoku-gaku" for translation of forensic toxicology. In 1982, Prof. Yoshimura and his friends established the Japanese Association of Forensic Toxicology, consisting of people from legal medicine, pharmacy and police institutes. This Association enabled lively discussions among different fields and greatly contributed to advances of forensic toxicology in Japan. We started studies of forensic toxicology using gas chromatography (GC)/mass spectrometry (MS) in 1979. Until now, we delt with solid-phase extraction (1987-1994), surface ionization GC (1989-1997), negative ion chemical ionization MS (1981-now), solid-phase microextraction (1994-now), cryogenic oven trapping GC (1997-now), surface ionization organic MS (1998-now) and high-performance liquid chromatography/tandem MS (1998-now). In this review, the author presents some details of solid-phase microextraction, negative ion chemical ionization MS, cryogenic oven trapping GC and surface ionization organic MS. Unprecedented poisoning terrorism by use of sarin took place in Matsumoto and Tokyo in 1994 and 1995, respectively. On July 25, 1998, a curry poisoning incident using arsenious acid occurred in Wakayama, resulting in the death of 4 people and injury of 63 people. Since then, more than 30 imitative poisoning cases have been reported by mass communication within 1 year. In spite of the above continuing poisoning cases, almost no effective measures have been taken by the administration of our country and local governments. Many serious problems concerning poisoning and drug abuse are accumulating in Japan. In this review, the problems are also made manifest, and some proposals are presented to solve the problems.

Forensic Medicine↗
PubMed1999

Analysis of methanol or formic acid in body fluids by headspace solid-phase microextraction and capillary gas chromatography.

Methanol and its metabolite formic acid have been found extractable from human whole blood and urine by headspace solid-phase microextraction (SPME) with a Carboxen/polydimethylsiloxane fiber. The headspace SPME for formic acid was carried out after derivatization to methyl formate under acidic conditions. The determinations of both compounds were made by using acetonitrile as internal standard (IS) and capillary gas chromatography (GC) with flame ionization detection. The headspace SPME-GC gave sharp peaks for methanol, methyl formate and I.S.; and low background noises for whole blood and urine samples. Extraction efficiencies were 0.25-1.05% of methanol and 0.38-0.84% formic acid for whole blood and urine. The calibration curves for methanol and formic acid showed excellent linearity in the range of 1.56 to 800 and 1.56 to 500 microg/0.5 ml of whole blood or urine, respectively. The detection limits were 0.1-0.5 microg/0.5 ml for methanol and 0.6 microg/0.5 ml for formic acid for both body fluids. The within-day relative standard deviations in terms of extraction efficiency for both compounds in whole blood and urine samples were not greater than 9.8%. By using the established SPME method, methanol and formic acid were successfully separated and determined in rat blood after oral administration of methanol.

Acetonitriles↗
PubMed1999

Identification and quantification of cardiac glycosides in blood and urine samples by HPLC/MS/MS.

Cardiac glycosides (CG) are of forensic importance because of their toxicity and the fact that very limited methods are available for identification of CG in biological samples. In this study, we have developed an identification and quantification method for digoxin, digitoxin, deslanoside, digoxigenin, and digitoxigenin by high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). CG formed abundant [M + NH4]+ ions and much less abundant [M + H]+ ions as observed with electrospray ionization (ESI) source and ammonium formate buffer. Under mild conditions for collision-induced dissociation (CID), each [M + NH4]+ ion fragmented to produce a dominant daughter ion, which was essential to the sensitive method of selected reaction monitoring (SRM) quantification of CG achieved in this study. SRM was compared with selected ion monitoring (SIM) regarding the effects of sample matrixes on the methodology. SRM produced lower detection limits with biological samples than SIM, while both methods produced equal detection limits with CG standards. On the basis of the HPLC/MS/MS results for CG, we have proposed some generalized points for conducting sensitive SRM measurements, in view of the property of analytes as well as instrumental conditions such as the type of HPLC/MS interface and CID parameters. Analytes of which the molecular ion can produce one abundant daughter ion with high yield under CID conditions may be sensitively measured by SRM. ESI is the most soft ionization source developed so far and can afford formation of the fragile molecular ions that are necessary for sensitive SRM detection. Mild CID conditions such as low collision energy and low pressure of collision gas favor production of an abundant daughter ion that is essential to sensitive SRM detection. This knowledge may provide some guidelines for conducting sensitive SRM measurements of very low concentrations of drugs or toxicants in biological samples.

Animals↗
PubMed1999

Implanted octacalcium phosphate (OCP) stimulates osteogenesis by osteoblastic cells and/or committed osteoprogenitors in rat calvarial periosteum.

Our previous studies demonstrated that the octacalcium phosphate (OCP) causes new appositional bone formation on the OCP when implanted into the subperiosteal region of murine calvaria. The OCP may stimulate the cell population committed to the osteoblastic differentiation in the periosteum and have them express the phenotype. The present study was designed to investigate which periosteal cell population is involved in bone formation on the OCP with applying the OCP implants on top of and underneath the periosteum. The periosteum of the rat parietal bones was flapped and the OCP was implanted on top of or underneath the periosteum, in which the implantation sites were defined using the membrane filter. The histology was examined to see if new appositional bone formation occurs on the OCP implant under each condition. New bone was deposited on the OCP on the bone surface separated from the periosteum by the filter, whereas no bone was formed either under the periosteum separated from the bone surface by the filter or on the periosteum. The present study suggests that the OCP acts on osteoblasts, bone lining cells and/or their closely committed progenitors on the bone surface to express the phenotype and deposit new bone on the OCP implant.

Animals↗
PubMed1999

Elevated levels of pro-inflammatory cytokines in coronary artery thrombi.

To validate the hypothesis that artery sites occluded with thrombi release pro-inflammatory cytokines, we measured concentrations of interleukin (IL)-6 and IL-8 in infarct-related coronary artery thrombi and atherosclerotic plaque specimens obtained with a transluminal extraction catheter (TEC) from cases of acute myocardial infarction (MI). Fifteen patients (group I) were enrolled in the study and four sets of samples were obtained (taken from the right atrium both before and after angioplasty, from infarct-related coronary artery thrombi and atherosclerotic plaque aspirated with a TEC and from the thoracic aorta aspirated with a TEC). Ten patients undergoing elective TEC served as controls (group II). IL-6 and IL-8 were measured in all patients by means of an enzyme-linked immunosorbent assay. Both IL-6 and IL-8 levels of infarct-related coronary artery samples in group I were significantly higher than in group II (mean +/- SEM, 15.3+/-4.5 vs. 3.8+/-1.2 pg/ml; P<0.01 and 44.0+/-2.4 vs. 15.6+/-0.6 pg/ml; P<0.01, respectively). The results suggest that pro-inflammatory cytokines originate from occluded coronary arteries in acute MI.

Angioplasty, Balloon, Coronary↗
PubMed1999

Use of an ion-pairing reagent for high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry determination of anionic anticoagulant rodenticides in body fluids.

The on-line combination of high-performance liquid chromatography with mass spectrometry (HPLC-MS) has become a powerful tool for trace analysis thanks to the developments in interface techniques. However, non-volatile salts such as ion-pairing reagents are considered to be incompatible with HPLC-MS systems; they cause drops in analyte signals because of contamination of mass analyzers and also because of blocking of the capillary transferring ions from atmospheric pressure to the vacuum manifold. In this work, a new type of ion-pairing reagent, di-n-butylammonium acetate (DBA), was evaluated for use in HPLC-MS. DBA did not cause these problems to HPLC-MS systems; a possible explanation might be that DBA decomposed to volatile compounds under APCI conditions. In addition, DBA was very useful for obtaining sharp peaks, which resulted in high sensitivity. With this ion-pairing reagent, we developed a procedure for the measurement of five (including internal standard) anticoagulant rodenticides in whole blood and urine samples by SIM detection of [M-H]- ions. Calibration range, recoveries and precision of the method were examined; detection limits as low as 1-5 ng/ml blood sample or 0.5-2.5 ng/ml urine sample were achieved.

Animals↗