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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 217 records · Page 12Linked to original sources
PubMed1998

Sarcocystis suihominis detected for the first time from pigs in Japan.

Sarcoystis suihominis was detected for the first time in Japan from the heart and diaphragm of 5 out 600 older culled breeding pigs slaughtered in Saitama Prefecture, Japan. Fresh cysts were 1,080-2,040 x 106-170 microns in size. Bradysoites measured 15 x 4 microns on average. The cyst wall was usually observed thick, 4-6 microns, and striated, but occasionally thin and smooth according to the difference in sectioning angle and in portion of cysts. Scanning electron microscopy showed that many palisade-like villar protrusions, 6-6 x 0.3-0.5 microns in size, were closely folded onto the surface of cyst. A small number of microtubules were seen in the core of protrusion. No dogs nor domestic cats fed with 20 fresh cysts each excreted oocysts or sporocysts in the feces throughout the experimental period of 30 days.

Animals↗
PubMed1998

[Delayed ischemic neurological deficit that developed over 15 days after subarachnoid hemorrhage].

We retrospectively studied subarachnoid hemorrhage (SAH) patients with delayed ischemic neurological deficit (DIND), and analyzed the factors causing extremely late onset of deficits occurring over 15 days after onset of the SAH. Among 605 patients with SAH, 201 (33%) developed DIND. Among DIND patients, 137 had undergone early aneurysm surgery. In these 137 patients, onset date of DIND was definite in 131 patients. Six patients (5%) developed DIND over 15 days after SAH. All 6 had asymptomatic angiographical vasospasm and infections, most often meningitis, before the onset of DIND. Compared with cases in which there was ordinary onset of DIND, other statistically significant factors among these 6 patients were intracerebral hemorrhage, sepsis and meningitis. We suspect that DIND were manifested subclinically in the early period because of the associated hyperdynamic hemodynamics resulting from sepsis in these patients.

Adult↗
PubMed1998

[Usefulness of multiple burr-hole operation for child Moyamoya disease].

Excellent results of multiple burr-hole operation (MBHO) for child moyamoya disease are reported in this study. Three patients of moyamoya disease had MBHO. After MBHO, transient, ischemic attacks disappeared in a patient despite progressing stenosis of the major cerebral arteries, and remarkable neurological improvement was recognized in a patient who had encephaloduroarteriosynangiosis. Another patient slowly improved and became able to go to junior high school. N-isopropyl-p-[123I] iodoamphetamine (IMPSPECT) findings also improved in all patients. There was no mortality or morbidity, and no new neurological deficits or bleedings developed during the follow up period. The authors recommend the MBHO as the surgical treatment of choice for not only adult but also child moyamoya disease because of its safety and effectiveness, and also report the usefulness of MBHO for the patients who have already received other bypass operations.

Adolescent↗
PubMed1998

[Changes of arterial ketone body ratio (AKBR) in patients with intracerebral hemorrhage].

The arterial ketone body ratio (AKBR) is considered to be an accurate index of the functional reserve of the liver, and the validity of this idea has been confirmed in the field of abdominal surgery. We found low AKBR value intracerebral hemorrhage patients and discussed the clinical significance of this finding in this paper. Twenty-five patients with intracerebral hemorrhage treated at our institution were included in this study. Their ages ranged from 42 to 86 years old (average 68.5 years). There were 13 cases of putaminal hemorrhage and 12 cases of thalamic hemorrhage. Evacuation of the hematoma or ventricle drainage was performed in 20 of these cases within 3 days after symptoms of intracerebral hemorrhage appeared. There were 12 cases with intraventricular hemorrhage. The outcome of these patients was as follows; 17 cases survived, eight cases died. We collected blood samples on days 1, 2, 3, 7 and 10 after the onset of symptoms (day 0) and measured the following: 1, beta-hydroxybutyrate; 2, acetoacetate; 3, epinephrine; 4, norepinephrine. On day 0 total ketone body levels were higher (246.3 +/- 231.7 mumol/l), AKBR values (0.60 +/- 0.18) were significantly lower than in the control group (2.05 +/- 1.35) (p < 0.001). However, both epinephrine and norepinephrine levels were significantly higher, 638.4 +/- 229.0 pg/ml and 1036.5 +/- 288.2 pg/ml, respectively. The AKBR value was 0.76 +/- 0.19 on day 1, 1.04 +/- 0.30 on day 2, and increased thereafter. In addition, the relation between sequential changes of AKBR in patients with intraventricular hemorrhage and outcome were also discussed. AKBR values are known to decrease not only in cases of hepatic failure, but in cases in which the liver energy charge is reduced, such as shock and hypoxemia, but no investigations have ever been performed to determine whether AKBR is altered in cerebrovascular disease. In this study, we found that AKBR values were lower in intracerebral hemorrhage, presumably due to reduced hepatic blood flow causes by increased levels of epinephrine and norepinephrine. In addition, our findings suggest that the fluctuations in AKBR values correlated with the outcome of intracerebral hemorrhage patients.

Adult↗
PubMed1998

[Clinical experience of autologous blood transfusion and fibrin glue in neurosurgery].

Clinical experience of autologous blood preservation on 83 patients and transfusion on 43 patients were reported. When drawing blood, 14 patients whose hemoglobin level was below 13 g/dl (body weight < 70 kg) or 14 g/dl (body weight > 70 kg) received subcutaneous recombinant human erythropoietin injection (s.c.) to facilitate erythropoiesis, according to the internal standard protocol. Hemoglobin levels of all the patients recovered to more than 10 g/dl by the time they were admitted to the hospital, which value would not interfere with general neurosurgical procedures. The injection of erythropoietin did not cause any side effects. Autologous blood transfusion was performed in 43 patients but, in 3 patients, additional homologous transfusion was required because of excessive bleeding. Except in cases with meningioma, postoperative hemoglobin values were identical with preoperative values, indicating that autologous blood transfusion was enough to replace intraoperative blood loss. Autologous fibrin glue was applied in 74 patients. In 70 cases including 55 with skull base surgery, the glue was applied to ensure dural closure. The incidence of cerebrospinal fluid leakage was 16.4% (5 patients) in skull base surgery. This incidence was identical to or less than that in previous reports. The glue was also effective in transposing and fixing offending vessels in 4 cases which received microvascular decompression. As a conclusion, procedures for autologous blood preservation and transfusion were safely performed in neurosurgical cases. Review of the literature was also presented to discuss the advantages and problems to be solved in the future.

Adolescent↗
PubMed1998

[Clinical usefulness of serum PIVKA-II levels determined by ECLIA system as a tumor maker for hepatocellular carcinoma].

PIVKA-II is well known as a tumor maker of hepatocellular carcinoma (HCC). We measured serum PIVKA-II concentrations with a commercially available PIVKA-II immunoassay kit (Picolumi PIVKA-II: Eisai Co., Ltd., Tokyo) using Electrochemiluminescence Immunoassay (ECLIA). ECLIA system is a novel immunoassay system using a Ruthenium (II) Tris (bipyridyl) luminesced by electric energy. Cut off value was 40 mAU/ml by receiver-operating characteristic curves as a tumor maker for HCC. Eighty-nine out of 142 (62.2%) patients with HCC had elevated serum PIVKA-II levels and seventeen out of 36 (47.2%) patients whose tumor size was below 2 cm in diameter showed high PIVKA-II levels. We determined the serial changes in serum PIVKA-II levels of two patients with HCC following initial therapy. In these patients, elevations of serum PIVKA-II levels determined by ECLIA system preceded the HCC relapse detected by imaging diagnostic procedures. In summary, this assay system is suitable for detecting small increases in PIVKA-II concentrations. Determination of PIVKA-II by this assay system is found to be useful for the early detection of HCC.

Aged↗
PubMed1998

Supraannular aortic root enlargement in patients with small aortic annulus: efficacy and safety.

BACKGROUND: To accommodate optimal sized aortic valve, our experiences with supraan-nular aortic root enlargement (SAE) in 20 patients with small aortic annulus have been described. METHODS: From June 1981 to April 1996, aortic valve replacement with a St. Jude Medical (SJM) valve had been performed in 46 patients with aortic stenosis consecutively. After August 1993, we employed SAE in patients to insert 23 mm or larger aortic prostheses (SAE group, n = 20; control group, n = 26). Patients were followed-up for a period of 1.7 to 8.3 years. RESULTS: There were no intra- or postoperative complications. The pressure gradient across the prosthesis was greater than 30 mmHg in 4 patients of the control group and in 1 patient of the SAE group. Only in nineteen patients (73%) of the control group, 23 mm or larger sized valves could be implanted by a conventional technique. By contrast, with SAE, 23 mm or larger sized SJM prostheses were possible to implant in 19 out of 20 patients (95%). CONCLUSION: To avoid valve-patient mismatch, SAE of aortic root is safe and effective.

Aortic Valve↗
PubMed1998

Neutron capture therapy with a new boron-porphyrin compound in the rat 9L glioma model.

Neutron capture therapy with a new boron-porphyrin compound was tested in a rat brain tumor model. Although the concentration of boron in the tumor was too low to elicit a therapeutic effect, prominent histopathologic changes, such as necrosis, congestion and bleeding were observed in the tumors of the rats which were administered the boron neutron capture therapy.

Animals↗
PubMed1997

Interaction of Angeli's salt with cytochrome P450 1A2 distal mutants: an optical absorption spectral study.

Angeli's salt, Na2N2O3 or O-N=N+-(OH)(O-) in aqueous solution, is known to release NO- or NO., which relaxes vascular tissue and lowers blood pressure. In the liver, the most abundant heme enzyme is cytochrome P450. In the present study, we studied the effect of rat liver cytochrome P450 1A2 (P450 1A2) in regard to its catalysis of the N=N bond scission of Angeli's salt with optical absorption spectra. Also, we examined the contribution of putative distal amino acids of P450 1A2 to the reaction with the salt. We found that wild-type Fe3+ P450 1A2 markedly enhances the N=N scission of the salt up to 100 fold in terms of absorption spectroscopy. A Fe3+ P450 1A2-NO complex with an absorption peak at 435 nm was formed when the salt was added and the complex was then changed to a 6-coordinated Fe2+-NO complex having a 440-nm peak. Glu318Asp, Glu318Ala and Thr319Ala mutants at the putative distal site of P450 1A2 formed a 5-coordinated Fe2+-NO complex having a 400-nm absorption, that was not formed with the wild type. The Glu318Ala mutant, in particular, did not form the Fe3+-NO complex with the addition of Angeli's salt. The presence of L-Cys, reduced glutathione, catalase or superoxide dismutase markedly stabilized the Fe3+ wild type-NO complex. Thus, our data suggests that the N=N bond of Angeli's salt is cleaved with the P450 1A2 active site and NO- or NO. is released. We discuss mechanisms of redox and ligand changes of the P450 heme.

Animals↗
PubMed1997

A Case of Apocrine Carcinoma of the Breast Presenting as Two Cysts.

A case of apocrine carcinoma of the breast presenting as two cysts is reported. A 60-year-old woman had two soft, mobile, well-defined masses measuring 4 x 2.5 cm and 1.5 x2.5 cm in diameter in the lower-inner quadrant of the right breast. Tumor markers such as CEA, CA15-3, BCA225 and NCC-ST-439 were within normal limits. Mammography showed two oval radioopaque masses with microcalcificatin in the smaller one. Ultrasonography disclosed two cysts and papillary projection in the larger one. Fine needle aspiration cytology revealed apocrine carcinoma of the breast. Excisional biopsy confirmed the diagnosis of apocrine carcinoma with focal invasion. Modified radical mastectomy was performed. Pathological study showed that the tumor mainly proliferated in the cysts and the two cysts communicated with each other through an involved duct. There was no apocrine metaplasia in adjacent mammary gland. There were no metastatic lymph nodes. This case may be regarded as intraductal apocrine carcinoma developing two cysts with focal invasion.

Journal Article↗
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

Chitin particle-induced cell-mediated immunity is inhibited by soluble mannan: mannose receptor-mediated phagocytosis initiates IL-12 production.

Previous studies showed that mouse spleen cells produced IL-12, TNF-alpha, and IFN-gamma when stimulated with phagocytosable-size chitin particles (N-acetyl-D-glucosamine polymers). To dissect the mechanisms of the cytokine production in this study, spleen cells from BALB/c mice were cultured with 1 to 10 microm chitin particles, heat-killed Corynebacterium parvum vaccine, zymosan, and mannan (a mannose polymer)-coated latex beads (1 microm) at 1, 10, or 100 microg/ml. We found that these particles induced IL-12, TNF-alpha, and IFN-gamma. However, these cytokines were not produced when spleen cells were cultured with soluble chitin, mannan, or laminarin (a polymer of beta-glucan), 1 to 10 microm beta-glucan particles, laminarin-coated latex beads, 1 microm latex beads, 50 to 100 microm chitin particles, or 50 to 100 microm mannan-coated beads. Soluble mannan, but not soluble laminarin, inhibited cytokine production following stimulation with 1 to 10 microm chitin particles, zymosan, or heat-killed C. parvum. In addition, cytochalasin D also inhibited cytokine production. The treatments with soluble mannan or with cytochalasin D, in sharp contrast, did not inhibit LPS-induced IL-12/IFN-gamma production or exogenous IL-12-induced IFN-gamma production. Finally, spleen cells from C3H/HeJ mice also showed comparable levels of IL-12/TNF-alpha/IFN-gamma production when induced by 1 to 10 microm chitin particles. Taken together, our results indicate that mannose receptor-mediated phagocytosis, but not the receptor-mediated pinocytosis, is highly associated with the production of IFN-gamma-inducing extracellular signaling factors such as IL-12 and TNF-alpha. The novel mechanism of phagocytosis-dependent IL-12 production appears to be distinct from that of LPS-induced cytokine production.

Actins↗
PubMed1997

Tumor specific contrast enhancement study of Mn-metalloporphyrin (ATN-10)--comparison of rat brain tumor model, cytotoxic and vasogenic edema models.

ATN-10, Mn-metalloporphyrin, has been developed as a tumor selective contrast agent for magnetic resonance (MR) imaging. To investigate the tumor specificity of ATN-10, we produced three experimental in vivo models; rat bran tumor (9L glioma) model, vasogenic (cold injury) and cytotoxic brain edema (24-hour MCA occlusion) models. The time course of contrast enhancement was compared after intravenous injection of ATN-10 or Gd-DTPA, measuring the signal intensity of the region of interest. After ATN-10 administration, the 9L glioma model showed early (5 min) and delayed (24 hr-) peak enhancement whereas the cold injury model showed only early enhancement and the 24-hour MCA occlusion model did not show significant enhancement. After Gd-DTPA administration, all three models showed similar pattern of only early enhancement. As a contrast agent for MR imaging, ATN-10 showed different behavior than Gd-DTPA in demonstrating the blood-brain barrier disruption and moreover ATN-10 showed selective enhancement in experimental brain tumors.

Animals↗