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Biomedical subjects

O Suzuki

Publications and source records attributed to O Suzuki.

At least 73 records · Page 4Linked to original sources
PubMed1999

Cloning and expression of Der f 6, a serine protease allergen from the house dust mite, Dermatophagoides farinae.

House dust mite allergen is thought to be a major cause of asthma. Characterization of these allergen molecules is therefore an important step for the development of effective diagnostic and therapeutic agents against mite-associated allergic disorders. Here we report molecular cloning and expression of the group 6 (chymotrypsin-like) allergen from the house dust mite, Dermatophagoides farinae. Sequencing analysis indicates that cloned cDNA, designated Der f 6, encodes a 279 amino acid polypeptide which conserves a primary structure characteristic for chymotrypsin-like serine proteases found in mammals. Recombinant Der f 6 expressed in Escherichia coli bound IgE in a pool made of 20 sera, and induced histamine release from patients' peripheral blood cells.

Allergens↗
PubMed1999

Ultra-sensitive method for determination of ethanol in whole blood by headspace capillary gas chromatography with cryogenic oven trapping.

We have established an ultra-sensitive method for determination of ethanol in whole blood by headspace capillary gas chromatography (GC) with cryogenic oven trapping. After heating a blood sample containing ethanol and isobutyl alcohol (internal standard, IS) in a 7.0-ml vial at 55 degrees C for 15 min, 5 ml of the headspace vapor was drawn into a glass syringe and injected into a GC port. All vapor was introduced into an Rtx-BAC2 wide-bore capillary column in the splitless mode at -60 degrees C oven temperature to trap entire analytes, and then the oven temperature was programmed up to 240 degrees C for GC measurements with flame ionization detection. The present method gave sharp peaks of ethanol and IS, and low background noise for whole blood samples. The mean partition into the gaseous phase for ethanol and IS was 3.06+/-0.733 and 8.33+/-2.19%, respectively. The calibration curves showed linearity in the range 0.02-5.0 microg/ml whole blood. The detection limit was estimated to be 0.01 microg/ml. The coefficients of intra-day and inter-day variation for spiked ethanol were 8.72 and 9.47%, respectively. Because of the extremely high sensitivity, we could measure low levels of endogenous ethanol in whole blood of subjects without drinking. The concentration of endogenous ethanol measured for 10 subjects under uncontrolled conditions varied from 0 to 0.377 microg/ml (mean, 0.180 microg/ml). Data on the diurnal changes of endogenous ethanol in whole blood of five subjects under strict food control are also presented; they are in accordance with the idea that endogenous blood ethanol is of enteric bacterial origin.

Calibration↗
PubMed1999

Molecular cloning and functional characterization of rat delta-6 fatty acid desaturase.

Mammalian cDNA fragments putatively encoding amino acid sequences characteristic of the fatty acid desaturase were obtained using expressed sequence tag (EST) sequence informations. These fragments were subsequently used to screen a rat liver cDNA library, yielding a 1573-bp clone. Expression of DNA fragment containing either of two possible open reading frames (nucleotide numbers 97-1431 and 148-1431) of the isolated clone in yeast led to the accumulation of gamma-linolenic acid in the presence of exogenous linoleic acid. In this system, the addition of alpha-linolenic acid also resulted in the accumulation of its Delta-6 desaturated product whereas dihomo-gamma-linolenic acid failed to be a substrate. These results indicate that the protein encoded by the rat cDNA is Delta-6 fatty acid desaturase, and the first 17 amino acids corresponding to the coding region 97-147 of the clone are not required to function in yeast.

Amino Acid Sequence↗
PubMed1999

High performance liquid chromatography/electrospray tandem mass spectrometry for phenothiazines with heavy side chains in whole blood.

Eleven phenothiazine derivatives with heavy side chains contained in human whole blood have been analyzed by high-performance liquid chromatography (HPLC)/electrospray (ES) tandem mass spectrometry (MS). All compounds gave the base peaks due to [M + 1](+) by HPLC/ES single MS. The product ions formed from each quasi-molecular ion by HPLC/ES tandem MS showed the base peaks due to side chains liberated. The mass chromatography of HPLC/ES tandem MS showed much higher sensitivity than that of HPLC/ES single MS for phenothiazines spiked to whole blood. Therefore, regression equations, detection limits, recovery rates and reproducibility were studied for thiethylperazine, clospirazine and flupentixol spiked to human whole blood by means of mass chromatography of HPLC/ES tandem MS. The three compounds showed good linearity in the range of 2-40 ng/mL with a detection limit of about 0.5 ng/mL. Recoveries of the three compounds spiked to whole blood (2 and 8 ng added to 1 mL whole blood) were 43.4-72.5 %; the coefficients of intraday and interday variations were 3.7-9.3 and 12.6-17.9 %, respectively. Thiethylperazine, clospirazine and flupentixol in whole blood could actually be determined with sufficient sensitivity 3 and 6 h after oral administration of 5-10 mg of each compound in a volunteer.

Administration, Oral↗
PubMed1999

Phaseolus vulgaris leukoagglutinating lectin-binding reactivity in human diffuse large B-cell lymphoma and its relevance to the patient's clinical outcome: lectin histochemistry and lectin blot analysis.

Many reports have suggested a strong correlation between certain lectin-binding patterns and biological behavior in various tumors. To clarify a relationship between lectin-binding reactivity and survival of patients with diffuse large B-cell lymphoma (B-DLCL), 57 cases with B-DLCL were analyzed by lectin histochemistry and lectin blot method with or without treatment of neuraminidase or acidic hydrolytic conditions. B-DLCL cases were grouped into three types based on the data on lectin-binding reactivity under neuraminidase-treated or untreated conditions: (i) Group A (non-reactive type); (ii) Group B (sialylated type); and (iii) Group C (non-sialylated type). Among various lectins, Phaseolus vulgaris-L (L-PHA) binding reactivity showed that the survival of patients with Group A + B or Group B was significantly shorter than that of patients with Group C. Lectin blot analysis revealed failure of L-PHA-binding to 32 kd and 29 kd glycoproteins, which may be attributable to the masking of L-PHA-binding sites by sialylation or the lack of L-PHA-binding sites, leading to the short survival of patients with B-DLCL. L-PHA-binding reactivity may be a useful marker for the evaluation of survival of patients with B-DLCL.

Adult↗
PubMed1999

Appropriate blood flow for arterio-portal shunt in acute hypoxic liver failure.

Hepatic arterial interruption inevitably leads to fatal liver hypoxia when all the collateral arteries to the liver have been eradicated. To prevent such hypoxia, we aimed to determine the appropriate flow of arterial blood in the arterio-portal shunt (APS). After division of all the arteries to the liver, we created three types of APSs between the common hepatic artery (CHA) and the portal vein in dogs, using catheters which were adjusted to pass blood flows of approximately half (group I), equal to (group II) and twice (group III) the CHA blood flow before shunting, except in the control (no-shunt) group. Postoperatively, at 1 and 48 h, we examined the hemodynamics of the liver biochemically and pathologically. After shunting, portal blood flow and oxygen saturation markedly increased, whereas portal venous pressure did not rise significantly. The serum alanine aminotransferase level was significantly higher in the no-shunt group and group I than in group II. Only in group II was the preoperative energy charge maintained, and light- and electron-microscopic examinations revealed no degeneration of the hepatocytes. APS blood flow similar to the original CHA (as in group II) is most appropriate for preventing liver hypoxia.

Alanine Transaminase↗
PubMed1999

Implantation of octacalcium phosphate (OCP) in rat skull defects enhances bone repair.

Synthetic octacalcium phosphate (OCP) enhances bone formation if implanted into the subperiosteal region of murine bone. Such implanted OCP may be resorbed and replaced by bone with time. We hypothesized that OCP could be used as an effective bone substitute. To test this hypothesis, we designed the present study to investigate if bone repair in a rat skull defect is enhanced by the implantation of OCP. Rats were divided into two groups: OCP-treated animals and untreated controls. Six rats from each group were fixed at 4, 12, and 24 weeks after implantation. A full-thickness standardized trephine defect was made in the parietal bone, and synthetic OCP was implanted into the defect. After being examined radiographically, the specimens were decalcified and processed for histology. OCP implantation significantly promoted bone repair compared with the controls. A statistical analysis showed an increase in the area of radiopacity within the skull defect between week 4 and week 12. Histologically, bone was formed on the implanted OCP and along the defect margin at week 4. At week 12, the implanted OCP was surrounded by newly formed bone. At week 24, the defect was almost completely filled with bone. In the control, bone formation was observed only along the defect margin. The present results demonstrate that OCP could be used as an effective bone substitute.

Animals↗
PubMed1999

Extraction of chloroform and methylene chloride in human whole blood and urine by headspace solid phase microextraction (SPME).

Chloroform and methylene chloride were extracted from human whole blood and urine by headspace solid phase microextraction (SPME) using a Carboxen/polydimethylsiloxane (Carboxen/PDMS) fibre before capillary gas chromatography (GC)/flame ionization detection (FID). Whole blood or urine was placed in a vial and mixed with distilled water. The vial was heated at 30 degrees C, and the solvents were extracted from the headspace by SPME. The extraction efficiencies of chloroform and methylene chloride from whole blood were 40.3% and 35.8%, respectively; those for urine were 57.0% and 43.6%, respectively. The calibration curves for chloroform were linear in the range of 1-8 micrograms/ml for blood and urine samples, and those for methylene chloride in the range of 0.5-8 micrograms/ml. The detection limits for both compounds were 0.3 microgram/ml for whole blood and 0.2 microgram/ml for urine. The headspace SPME with Carboxen/PDMS fibre coupled with GC/FID seems useful for analyses of chloroform and methylene chloride in forensic toxicology and environmental chemistry.

Blood Chemical Analysis↗
PubMed1999

Effect of genetic background on establishment of mouse embryonic stem cells.

We established 13 embryonic stem (ES) cell lines from 542 embryos crossed between various strains of mice: 10 lines from 129/Sv-ter embryos (10/48, 20.8%) and 3 lines out of other 9 combinations of intra- or inter-strain matings (1 from intracross of C57BL/6CrSlc, 1 from B6D2F1 x C57BL/6CrSlc, 1 from Yok:ddY x Slc:ICR). No ES cell line from 129/Sv-ter x Slc:ICR embryos suggests that ICR strain might have inhibitory genetic factor(s) for the ES cell formation. Some ES cell lines could be obtained from hybrids even if none or few lines from their parental strains, suggesting a heterosis effect can be expected for establishing ES cell lines in mice.

Animals↗
PubMed1999

[Positivity rate of TTV-DNA in patients with acute liver injury of undetermined etiology].

To elucidate a role of TTV infection in patients with acute liver injury, TTV-DNA in the sera from 97 patients with acute liver injury of various etiology were determined according to Okamoto's method. Out of 77 patients with acute liver injury of determined etiology, 31 patients(40.3%) showed TTV-DNA positive, and out of 15 patients with acute liver injury of undetermined etiology, 8 patients(53.3%) showed TTV-DNA positive. These results suggested no evident role of TTV in patients with acute liver injury was shown. Further study including genotype and quantitative determination of TTV-DNA and antibody assay is needed.

Acute Disease↗
PubMed1999

Primary aortoduodenal fistula treated successfully with surgery in a patient with Takayasu's arteritis.

Takayasu's arteritis was originally described as a systemic inflammatory arterial disease presenting with occlusive changes. However, it has also been known to cause aneurysm formation. In this report, a patient with Takayasu's arteritis was found to have an aortoduodenal fistula. An emergency operation was carried out with resection of the saccular aneurysm and the fistula. The aorta was reconstructed with a prosthetic graft and the duodenum repaired. A pedicled omental flap was placed between the aorta and the duodenum. The postoperative recovery was uneventful, there was no evidence of persistent bleeding, and the patient was well at the 3-year follow-up. This is the first case in the English language literature of a primary aortoduodenal fistula treated successfully with surgery in a patient with Takayasu's arteritis.

Adult↗
PubMed1998

Determination of cyanide in whole blood by capillary gas chromatography with cryogenic oven trapping.

Cyanide, one of the most important toxic substances, has been found measurable with high sensitivity by capillary gas chromatography (GC) with cryogenic oven trapping upon injection of headspace (HS) vapor samples. The entire amount of cyanide in the HS sample could be cryogenically trapped prior to on-line GC analysis. A 0.5-mL volume of blood in the presence or absence of cyanide and propionitrile (internal standard, IS) was added to a vial containing 0.25 mL of distilled water, 0.3 g of Na2-SO4, 0.2 mL of 50% H3PO4, and 0.1 g of ascorbic acid (when needed), and the mixture was heated at 70 degrees C for 15 min. A 5-mL volume of the HS vapor was introduced into a GC capillary column in the splitless mode at -30 degrees C oven temperature that was programmed up to 160 degrees C for GC analysis with nitrogen-phosphorus detection. A sharp peak was obtained for cyanide under the present conditions, and backgrounds were very clean. The extraction efficiencies of cyanide and IS were 2.89-3.22 (100 or 500 ng/mL) and 2.42%, respectively. The calibration curve showed good linearity in the range of 25-1000 ng/mL and the detection limit was approximately 2 ng/mL. The coefficients of intraday and interday variations were 2.9 and 11.8%, respectively. The mean blood cyanide level measured for actual fire victims was 687 +/- 597 ng/mL (mean +/- SD, n = 9). Endogenous blood cyanide concentration for healthy subjects was 8.41 +/- 3.09 ng/mL (mean +/- SD, n = 6).

Chromatography, Gas↗
PubMed1998

Solid-phase microextraction (SPME) of drugs and poisons from biological samples.

Solid-phase microextraction (SPME), a new solvent-free sample preparation technique, was invented by C. Arthur and J. Pawliszyn in 1990. This method mainly was applied for the extraction of volatile and semi-volatile organic pollutants in water samples. However, since 1995, SPME has been developed to various biological samples, such as whole blood, plasma, urine, hair and breath, in order to extract drugs and poisons in forensic field. The main advantages of SPME are: high sensitivity, solventless, small sample volume, simplicity and rapidity. We have reviewed the papers published in recent years about SPME in biological samples, and sorted out main experimental conditions, such as fibers, matrixes, the extraction approaches and time, as well as the acceleration method. We would expect SPME technique to have a promising future for toxicological analysis in forensic practice.

Body Fluids↗
PubMed1998

Sensitive determination of xylenes in whole blood by capillary gas chromatography with cryogenic trapping.

A new and sensitive method for measurement of o-, m- and p-xylenes in human whole blood by capillary gas chromatography (GC) with cryogenic trapping is presented. After heating 0.5 ml of whole blood and 0.5 ml of distilled water containing the xylenes and aniline (internal standard, I.S.) in a 4.0-ml vial at 100 degrees C for 30 min, 2 ml of the headspace vapor was drawn into a glass syringe. All vapor was introduced through the GC port into an AT-Wax middle-bore capillary column in the splitless mode at an oven temperature of 5 degrees C to trap the entire analytes, and the oven temperature was then programmed up to 180 degrees C. The present conditions gave sharp peaks for xylenes and aniline (I.S.), and low background noises for whole blood samples; the peaks of p- and m-xylenes showed about 90% separation with the AT-Wax column. As much as 41.0-46.3% of xylenes, which had been spiked to whole blood could be recovered. The calibration curves showed linearity in the range of 0.1-0.5 microg/0.5 ml of whole blood. The detection limit was estimated to be about 10 ng/0.5 ml. The coefficients of intra-day and inter-day variations for xylenes were not greater than 9.38%. The data for actual detection of xylenes in post-mortem blood of self-ignition suicide cases by the present method were also presented.

Aged↗
PubMed1998

Headspace solid-phase microextraction and gas chromatographic determination of dinitroaniline herbicides in human blood, urine and environmental water.

Solid-phase microextraction (SPME) is a unique extraction and sampling technique, and it has been used for separation of volatile organics from water or other simple matrices. In this study, we have used SPME to separate dinitroaniline herbicides from complicated matrices of human urine and blood in order to broaden its application to biomedical analysis. The SPME conditions were optimized for water, urine and blood samples, in terms of pH, salt additives, extraction temperature, and fiber exposure time. Urine or water (1.0 ml) spiked with herbicides and 0.28 g of anhydrous sodium sulfate was preheated at 70 degrees C for 10 min, and a polydimethylsiloxane-coated fiber for SPME was exposed to the headspace at 70 degrees C for another 30 min; while spiked blood (0.5 ml) diluted with water (0.5 ml) was treated at 90 degrees C in the same way. The herbicides were extractable under these conditions, and could be determined by gas chromatography-electron capture detector (GC-ECD). The recoveries of the herbicides, measured at the concentrations of 0.50 and 1.0 ng/ml urine or water, or 6.0 and 20 ng/0.5 ml blood, ranged from 35 to 64% for different herbicides from water or urine, and from 3.2 to 7.2% from blood. The headspace SPME yielded clean extracts of dinitroaniline herbicides from urine, blood or water, which could be directly analyzed by GC-ECD without further purification. The peak areas of the extracted herbicides were proportional to their concentrations in the range 0.1-10 ng/ml in water or urine, or 1-60 ng/0.5 ml in blood. The lowest detectable concentration of the herbicides lay in 0.1 ng/ml water or urine, or in 0.5 ng/0.5 ml blood. The intra- and inter-day coefficients of variation were within 14% for most of the analytes. Although the recoveries of the herbicides were rather low, the linearity of calibration curve and the precision were good. The developed method is more sensitive and much simpler in sample preparation than previously reported ones. With the established SPME method, a dosed herbicide was successfully separated and determined in rats' blood.

Aniline Compounds↗