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Biomedical subjects

O Suzuki

Publications and source records attributed to O Suzuki.

At least 91 records · Page 5Linked to original sources
PubMed1998

Development of normal mice from metaphase I oocytes fertilized with primary spermatocytes.

Primary spermatocytes are the male germ cells before meiosis I. To examine whether these 4n diploid cells are genetically competent to fertilize oocytes and support full embryo development, we introduced the nuclei of pachytene/diplotene spermatocytes into oocytes that were arrested in prophase I (germinal vesicle stage), metaphase I, or metaphase II (Met II). Both the paternal and maternal chromosomes then were allowed to undergo meiosis synchronously until Met II. In the first and second groups, the paternal and maternal chromosomes had intermingled to form a large Met II plate, which was then transferred into a fresh enucleated Met II oocyte. In the third group, the paternal Met II chromosomes were obtained by transferring spermatocyte nuclei into Met II oocytes twice. After activation of the Met II oocytes that were produced, those microfertilized at metaphase I showed the best developmental ability in vitro, and three of these embryos developed into full-term offspring after embryo transfer. Two pups (one male and one female) were proven to be fertile. This finding provides direct evidence that the nuclei of male germ cells acquire the ability to fertilize oocytes before the first meiotic division.

Animals↗
PubMed1998

A rare case of spontaneous esophageal rupture (Boerhaave's syndrome) associated with pulmonary rupture.

Spontaneous esophageal rupture (Boerhaave's Syndrome) is a life-threatening condition that requires early diagnosis and effective treatment. The authors describe a rare case of spontaneous rupture of the esophagus associated with pulmonary rupture in a 54-year-old man. The anatomical basis for the occurrence of a spontaneous esophageal rupture associated with pulmonary rupture is discussed.

Esophageal Diseases↗
PubMed1998

Dietary Mg and/or K restriction enhances paraquat toxicity in rats.

Effect of mineral restriction was studied to clarify which mineral in the diet is most indispensable in preventing paraquat (PQ) toxicosis. ODS rats were chosen as the experimental animal owing to the inability to synthesize vitamin C similarly to humans. Rats were fed with either mineral-adequate or restricted diets dosed with 125 ppm PQ. The mineral-adequate diet was based on the American Institute of Nutrition-76, and the restricted diet was one-half the amounts. Measurements were made on the onset day of PQ toxicosis, body weight changes during the feeding experiment, and changes of two acute phase reactant proteins cysteine proteinase inhibitor and alpha1-proteinase inhibitor. The minerals tested were divided into three classes: I, largely needed, Ca, K, Na, and Mg; II, moderately needed, Mn, Fe, Zn, and Cu; and III, minutely needed, Cr and Se, respectively. Rats fed with a Mg-restricted diet showed a severe toxicosis but those with a K-restricted diet, a mild toxicosis. No appreciable effect was observed by restriction of other minerals. A synergistic effect was observed in the restriction of Mg and K.

Animals↗
PubMed1998

Abdominal aortic aneurysm repair with arterial branch reconstruction: utility of the temporary bypass technique.

Between June 1992 and May 1996, five patients underwent an abdominal aortic aneurysm (AAA) repair with concomitant arterial branch reconstruction. All of the patients were males ranging in age from 55 to 66 years (mean: 61.6 years). The operations were performed for a localized abdominal aortic dissection, a pseudoaneurysm after patch angioplasty of a supraceliac AAA, a pararenal AAA, a total AAA with retrograde descending thoracic aortic dissection, and a supraceliac AAA after an infrarenal AAA repair. All patients underwent bilateral renal artery (RA) reconstruction. Three patients also had a concomitant reconstruction of the superior mesenteric artery ad celiac axis. The renal arteries were preferentially reconstructed. Visceral circulation during aortic cross-clamping was maintained via a temporary bypass circuit. A temporary division of the left renal vein was necessary in two patients. Overall, the mean renal ischemia time was 17.2min (range: 10 to 32 min). There was one perioperative death due to sepsis from a graft infection. Another patient died 6 months postoperatively due to pyothorax. One patient required postoperative hemodialysis for 1 month. Based on the above findings, the temporary bypass technique is thus considered to be useful for maintaining physiologic organ perfusion during aortic clamping without the need to use any complicated devices.

Aged↗
PubMed1998

Experimental study of tracheal patch reconstruction with a covered expandable metallic stent.

BACKGROUND: We evaluated the efficacy of tracheal patch reconstruction with a covered expandable metallic stent (EMS) with omentoplasty. METHODS: After resecting the right half of the circumferential wall of two tracheal rings in adult beagle dogs, we inserted a covered EMS to reconstruct the defect interiorly. Then, through laparotomy, we made an omental pedicle flap and wrapped it around the EMS-interposed area. For comparison with the group without omentoplasty, we periodically examined the healing process macroscopically and histologically. RESULTS: Bronchofiberscopic observations revealed that incorporation of the covered EMS progressed with the passage of time and tracheal luminal patency was maintained well in both groups. However, polyplike granulation developed gradually at both ends of the EMS. Histologically, epithelium was regenerated in the patched area 4 weeks postoperatively and the area was covered with pseudostratified ciliated epithelium at 12 weeks postoperatively. Quantitative analysis of the macroscopic and histologic findings showed that the inflammatory polyps were reduced and epithelialization was promoted in the group with omentoplasty. CONCLUSIONS: Tracheal patch reconstruction with a covered EMS, when combined with omentoplasty, promoted early epithelial regeneration and suppressed the development of inflammatory polyps.

Animals↗
PubMed1998

Nondissection method for tibial bypass surgery using Esmarch's rubber bandage or an automatic sequential pneumatic tourniquet: long-term results.

It is suspected that operative injury to the native arteries during a vascular bypass procedure causes periarterial fibrosis contributing to late graft failure. A a nondissection method for tibial artery bypass has been developed using Esmarch's rubber bandage or an automatic sequential pneumatic tourniquet. This retrospective study examined patency and other late results in distal bypass operations using the nondissection method. Between June 1982 and July 1995, 78 tibial bypasses were performed using reversed autogenous saphenous vein grafts in 70 patients (57 men, 13 women; mean age 57.4 years). Graft patency was assessed angiographically. When a stenotic lesion was recognized, the graft was revised and considered an assisted primary patency. Primary patency rates at 1, 3, 5, and 10 years were 82.8%, 75.3%, 63.4% and 63.4%, respectively, by life-table analysis. Six grafts required revision for stenosis; one involved distal anastomotic stenosis. As a result, assisted primary patency rates resembled secondary patency rates of 87.7%, 84.3%, 80.3%, and 80.3% at the same respective intervals. In conclusion, the nondissection method improved long-term patency by preventing late distal anastomotic stenosis.

Arterial Occlusive Diseases↗
PubMed1998

Determination of solvent thinner components in human body fluids by capillary gas chromatography with trapping at low oven temperature for headspace samples.

A simple and sensitive method is presented for determination of solvent thinner components in human body fluids by capillary gas chromatography (GC) with a low oven temperature for trapping headspace vapor components. After heating a blood or urine sample containing ethyl acetate, benzene, butan-1-ol, toluene, butyl acetate, isoamyl acetate and ethylbenzene (internal standard) in a 7.5 ml vial at 90 degrees C for 30 min, 5 ml of headspace vapor were drawn into a glass syringe. All vapor was introduced through an injection port in the splitless mode into a DB-624 medium-bore capillary column at a 5 degrees C oven temperature for trapping the volatile compounds, and the oven temperature was programmed up to 110 degrees C for their detection by GC. These conditions gave sharp peaks, a good separation of each peak and low background noise for both whole blood and urine samples. As much as 3.58-55.1 and 3.52-57.9% of the six compounds, which had been added to vials, could be introduced to the GC instrument for whole blood and urine, respectively. The intra-day RSD values in terms of the introduction rate (net recovery) of the six compounds in whole blood and urine samples were < or = 8.1%. The calibration curves showed linearity in the range 0.78-400 ng per 0.5 ml whole blood or urine. The detection limits were 0.5-5 ng per 0.5 ml. The data on toluene in post mortem blood in an actual case are also presented.

Adult↗
PubMed1998

Altered antigenicity of M-177, a 177-kDa allergen from the house dust mite Dermatophagoides farinae, in stored extract.

BACKGROUND: A high molecular weight allergen, M-177 (177 kDa) was isolated from Dermatophagoides farinae using a specific antibody raised to an allergenic clone Mag 3, which was obtained by immunoscreening a mite cDNA library. The potent IgE reactivity of M-177 is comparable with that of Der f 2. OBJECTIVE: The aim of this study was to analyse the molecular characteristics and the allergenic activity of M-177 in stored mite extracts. METHODS: Antigens were analysed by immunoblotting and enzyme-linked immunosorbent assay (ELISA; inhibition). Allergenic activity was estimated from IgE reactivity and the results of a histamine release assay. RESULTS: The intact M-177 molecule was present in high concentrations in fresh extract obtained from purified mite bodies, but was only detected in small amounts in stored extracts. Instead of the intact molecule, anti-Mag 3 antibody detected various cross-reactive antigens in the stored preparations. Studies of a stored liquid extract showed that these cross-reactive antigens were produced by the degradation of M-177, and that this change was suppressed by the addition of protease inhibitors. Interestingly, the allergenic activity of the fragmented M-177 (sM-177) isolated from the stored extracts was greater than that of the intact antigen. Specific IgE reacted with sM-177 in 84.2% of 38 sera samples from patients allergic to mites, while 65.8% were positive for M-177-specific IgE. Similarly, the histamine release test showed that sM-177 had greater allergenic activity in vitro. ELISA inhibition indicated that the increased allergenic activity resulted from alteration of the antigenicity with the degradation of M-177. CONCLUSIONS: M-177 is a protease-sensitive allergen. The breakdown products of M-177 provoked higher allergenic activity than the intact allergen.

Animals↗
PubMed1998

Monoamine oxidase activities in catfish (Parasilurus asotus) tissues.

The substrate- and inhibitor-related characteristics of monoamine oxidase (MAO) were studied for catfish brain and liver. The kinetic constants for MAO in both tissues were determined using 5-hydroxytryptamine (5-HT), tyramine and beta-phenylethylamine (PEA) as substrates. For both tissues, the Vmax values were highest with 5-HT and lowest with PEA. The Km value for the brain was highest with 5-HT, followed by tyramine and PEA; but for the liver its value was highest with PEA, followed by 5-HT and tyramine, although all values were in the same order of magnitude. The inhibition of MAO by clorgyline and deprenyl by use of 5-HT, tyramine and PEA as substrates showed that the MAO-A inhibitor clorgyline was more effective than the MAO-B inhibitor deprenyl for both catfish tissues; a single form was present since inhibition by clorgyline or deprenyl with 1000 microM PEA showed single phase sigmoid curves. It is concluded that catfish brain and liver contain a single form of MAO, relatively similar to mammalian MAO-A.

Animals↗
PubMed1998

Quantitation of postmortem profenofos levels.

CASE REPORT: An 88-year-old woman was found dead, and suicidal ingestion of profenofos, an organophosphate pesticide, was suspected. METHOD: Gas chromatography-nitrogen phosphorus detection was employed for quantitation of profenofos after its identification by gas chromatography/mass spectrometry. RESULTS: The levels of profenofos in whole blood, urine, and gastric contents were 1200 ng, 350 ng, and 3.35 mg/mL, respectively.

Administration, Oral↗
PubMed1997

Capillary gas chromatography with cryogenic oven temperature for headspace samples: analysis of chloroform or methylene chloride in whole blood.

A new and sensitive gas chromatography (GC) method for measurement of chloroform or methylene chloride in whole blood is presented. Trace levels of these analytes present in the headspace of samples were cryogenically trapped prior to on-line GC analysis. After heating of a blood sample containing chloroform and methylene chloride (internal standard, and vice versa) in a 7.0-mL vial at 55 degrees C for 20 min, 5 mL of the headspace vapor was drawn into a glass syringe. All vapor was introduced into an Rtx-Volatiles middle-bore capillary column in the splitless mode at -30 degrees C oven temperature to trap the entire analytes, and the oven temperature was programmed up to 280 degrees C for detection of the compounds and for cleaning of the column. The present conditions gave sharp peaks for both chloroform and methylene chloride and very low background noises for whole blood samples. As much as 11.5 and 20.0% of chloroform and methylene chloride, respectively, which had been added to whole blood in a vial, could be introduced into the GC column. The calibration curves showed linearity in the range of 0.05-5.0 micrograms/0.5 mL of whole blood. The detection limit was estimated to be about 2 ng/0.5 mL. The coefficients of intraday and interday variations were 1.31 and 8.90% for chloroform and 1.37 and 9.03% for methylene chloride, respectively. The data on chloroform or methylene chloride in rat blood after inhalation of each compound were also presented.

Animals↗
PubMed1997

Adsorption of Benzoic Compounds onto Stainless Steel Particles

Equilibrium experiment was conducted to investigate the factors determining the adsorption of benzoic acid (BA) and its derivatives, m- and p-hydroxy BA, onto SUS316L stainless steel particles of 8-10 &mgr;m diameter and under 100 mesh. Adsorption isotherms of these benzoic compounds were determined in the presence of 0.05 M NaCl at pH 4 and 30&deg;C. The adsorptions of the these compounds were described well by a Langmuirian model for both adsorbents. When the maximum number of the benzoic compound adsorption sites was expressed on the basis of unit surface area (N, mol/m2), the N values were relatively constant, while the greatest value of the affinity (K, ml/&mgr;mol) was obtained for p-hydroxy BA, although its value was in the same range as that of the other two adsorbates. Diffuse-reflectance Fourier transform infrared spectra of the fine adsorbent (8-10 &mgr;m diameter) after equilibration suggest that the adsorption mainly takes place through the carboxyl group of the adsorbate-stainless steel surface interaction for all adsorbates, whereas concomitant interaction occurs in part with participation of the phenolic hydroxyl group for p-OH BA adsorbate, accounting for the difference in adsorption properties. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Delayed manifestation of aortic stenosis after blunt abdominal trauma: report of a case.

Delayed manifestation of aortic stenosis caused by abdominal blunt trauma is rare. We report herein the case of a 67-year-old man who was taken to a nearby hospital after being crushed between a heavy truck and a wall. An emergency laparotomy was performed, revealing only a mesenteric tear which was repaired. He was discharged after an uneventful postoperative course; however, 1 month later he began to experience intermittent claudication, and presented to our hospital in December 1994, 1 year after the first operation. Angiography and enhanced computed tomography (CT) demonstrated infrarenal abdominal aortic dilatation with distal stenosis. Both the dilated and stenotic lesions were resected and bypass surgery ws performed. Pathologic examination demonstrated that the intima had been lacerated circumferentially and everted distally, causing the aortic stenosis. To our knowledge, this is the first case of the delayed manifestation of traumatic aortic stenosis to be documented in Japan. The etiology of this rare complication of blunt trauma is described in this report.

Abdominal Injuries↗
PubMed1997

Neurological manifestations of knockout mice with beta-galactosidase deficiency.

We succeeded in producing the beta-galactosidase-deficient knockout mouse by gene targeting in embryonic stem cells. The mutant mice developed progressive spastic diplegia within a few months after birth, and died of emaciation at 7-10 months of age. This is an authentic murine model of human GMI-gangliosidosis, and is useful for studies of its pathogenesis and treatment.

Animals↗
PubMed1997

Chromosomes of mouse primary spermatocytes undergo meiotic divisions after incorporation into homologous immature oocytes.

The primary spermatocytes used were male germ cells at prophase I. The present study was undertaken to see whether bivalent chromosomes of mouse primary spermatocytes can undergo meiotic divisions within maturing oocytes and participate in subsequent embryonic development. Primary spermatocytes (pachytene to diplotene) freshly collected from the testes of mature males were electrofused with immature oocytes shortly before or after germinal vesicle breakdown. After culture in MEM-alpha medium for 15 h, most (> 90%) of the oocytes containing spermatocyte chromosomes underwent maturation and arrested at metaphase II (MII). Among 23 MII oocytes examined, 17 (74%) had one group of chromosomes and one polar body, indicating that male chromosomes had intermingled with those of the females and completed the first meiotic division. Chromosome analyses of these MII oocytes demonstrated their diploidy. The metaphase chromosomes were transferred to enucleated MII oocytes freshly recovered from superovulated mice. After artificial activation, the reconstructed MII oocytes resumed meiosis and developed to the morula/blastocyst stage. However, no pups were born following embryo transfer into recipient females. These findings indicate that the chromosomes of primary spermatocytes undergo meiotic divisions in maturing oocytes and participate in the formation of diploid embryos.

Animals↗