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Biomedical subjects

Y Miyazawa

Publications and source records attributed to Y Miyazawa.

At least 55 records · Page 3Linked to original sources
PubMed1998

Reperfusion induces sublethal endothelial injury.

BACKGROUND: Endothelial cells are pivotal in regulating thrombosis and hemostasis. In this study, we sought to characterize endothelial dysfunction and endothelial cell injury in vitro after hypoxia/reoxygenation. MATERIALS AND METHODS: Cultured human umbilical vein endothelial cells (ECs) were exposed to 120 min of hypoxia followed by reoxygenation. The release of thrombomodulin (TM) and the production of prostaglandin I2 (PGI2) were measured. Endothelial cell injury in hypoxia/reoxygenation was measured by two assays, the Fura-2 release assay and the 51chromium (51Cr) release assay. RESULTS: TM release from ECs during normoxic incubation was undetectable, while it was slightly increased during hypoxic incubation. After reoxygenation, the release of TM increased, and it became significantly higher at 120 min after reoxygenation compared with hypoxic incubation. The production of PGI2 significantly decreased during hypoxic incubation and further decreased within 30 min after reoxygenation, but returned to normoxic levels at 120 min after reoxygenation. In the Fura-2 release assay, a rapid and significantly greater release of Fura-2 was observed in hypoxia/reoxygenation compared with hypoxic incubation. In the 51Cr release assay which demonstrates cell death, 51Cr release did not increase in hypoxia/reoxygenation. CONCLUSIONS: The present study suggests that 120 min of hypoxia/reoxygenation induces endothelial dysfunction of ECs but does not cause cell death.

Cell Death↗
PubMed1998

Depressive disorders as psychiatric complications after obesity surgery.

Three case reports of morbidly obese patients (two women and a man) who underwent vertical banded gastroplasty and who subsequently fell into depression, are presented here. The psychiatric diagnosis according to DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised), the eating pattern before obesity surgery, the past history of mental disorder, social adaptation before surgery, psychological gain from their obese state, and the presence of unrealistic expectations of obesity surgery were investigated. Case 1 was diagnosed postoperatively as having a major depressive episode without a personality disorder. Case 2 was diagnosed post-operatively as having a major depressive episode. Case 3 had a depressive disorder not otherwise specified. Cases 2 and 3 had a social phobia with comorbidity of personality disorders. Binge eating disorder was confirmed in all patients before obesity surgery. There were differences between case 1 and cases 2 and 3 based on the presence of personality disorder and the time of onset of depression. When some psychiatric characteristics are confirmed in obese patients, obesity surgery should be undertaken more prudently because the patients may manifest depression postoperatively. The pre-operative psychiatric assessment is essential for a decision on indication of obesity surgery.

Adult↗
PubMed1998

[Evaluation of a new method for susceptibility testing against fastidious and unusual bacteria].

The susceptibilities of 154 clinical isolates of fastidious and unusual bacteria were determined by the Etest, and were compared with the MICs for these strains obtained by the agar dilution method. Antimicrobial agents; benzylpenicillin, ampicillin, cefotaxime, imipenem, erythromycin, clindamycin and minocycline were used in this study. In general, the Etest MICs were rapidly and easily interpreted. The Etest MICs agreed within +/- 1 log2 and +/- 2 log2 dilution, 87.6% and 98.2% respectively in all strains tested. MICs of vancomycin with the Etest for S. pneumoniae and other Streptococci tended to be 1 to 2 log2 dilution higher than those of the agar dilution method. MICs of erythromycin for the other Streptococci also tended to be 1 to 2 log2 dilution higher. However, there were no significant differences for H. influenzae, Campylobacter spp., H. pylori, Capnocytophaga spp., E. corrodens, M. catarrhalis, N. gonorrhoeae, Corynebacterium spp., L. monocytogenes and Anaerobic bacteria. As mentioned above, the Etest represent a potential method for antimicrobial susceptibility testing of these fastidious and unusual bacteria.

Bacteria↗
PubMed1998

[Survey of fungemia cases during the past seventeen years at Teikyo University Hospital].

Fungi were isolated from 642 cases (3.5%) of 18,403 blood samples at Teikyo University Hospital during the 17-years period between 1979 and 1995. The number of fungemia cases began to increase around 1985, reached a peak in 1988, and since then, it has been gradually decreasing. The fungal species of isolates were: (1) Candida albicans in 224 cases (34.9%), (2) C. parapsilosis in 149 cases (23.2%), (3) C. tropicalis in 87 cases (13.6%), (4) C. glabrata in 65 cases (10.1%), (5) Hansenula anomala in 58 cases (9.0%), (6) C. guilliermondii in 24 cases (3.7%), (7) C. famata in 14 cases (2.1%), (8) Trichosporon beigelii in 11 cases (1.7%), (9) C. inconspicua in 5 cases (0.8%) and C. lusitaniae in 5 cases (0.8%), and other yeasts in 33 causes (5.1%). The number of isolates of C. albicans has been decreasing since 1989, concomitant with the clinical introduction of fluconazole in this hospital. However, the number of fluconazole-insusceptible fungi such as non-albicans Candida and Trichosporon spp. has increased. Fungemia cases infected concomitantly or sequentially with two or more different fungal species have been found occasionally since 1983 and have shown a high mortality rate. The spectrum of the causative organisms of fungemia appears to be, at least, partly influenced, by the usage of antifungal agents, particularly fluconazole.

Candida↗
PubMed1998

[Evaluation of routine blood cell counts in predicting the mobilization of CD34 positive cells].

The collection of peripheral blood stem cells (PBSC) is a crucial step for successful PBSC transplantation. Routine hematological parameters utilized for predicting the optimal timing of collection include white blood cell (WBC) counts, high fluorescence ratio (HFR) of reticulocytes, and platelet counts. We compared these parameters with the CD34-positive rates in the peripheral blood. In regimen with high-dose chemotherapy where the WBC count at nadir was lower than 1,000/microliter, we found that the maximum mobilization of PBSC was observed on the day when the WBC count reached 10,000/microliter. This coincidence was within about one day (mean 0.44, standard deviation 0.53). However, the reliability of the WBC count as a marker of PBSC mobilization varied among different harvest regimens. In the regimen with regular-dose chemotherapy where the WBC count at nadir was above 1,000/microliter, we could not find such a tight coincidence between the WBC count and PBSC mobilization. These results suggested that, in some situations, the measurement of the CD34-positive rate is mandatory for an efficient PBSC collection. We also found that the number of CD34-positive cells in the peripheral blood correlated (x) well to the amount of the CD34-positive cells actually harvested (y) (y = 0.524x + 0.249, r = 0.787). Thus, rapid fluorescence activated cell sorter (FACS) analysis of peripheral CD34-positive rates seemed to be extremely useful to predict the yield of PBSC collection.

Adult↗
PubMed1997

Dominant inheritance of Kabuki make-up syndrome.

We report on a total of 4 individuals in 2 families with Kabuki make-up syndrome. In family 1, the proposita, a 2 4/12-year-old girl and her mother had typical Kabuki make-up syndrome. The proposita also had early breast development. In family 2, the proposita, a 6-month-old girl and her mother had typical Kabuki make-up syndrome. The proposita died at age 6 months. Analysis of 2 families indicates that the condition is an autosomal dominant inheritance with variable expressivity.

Abnormalities, Multiple↗
PubMed1997

Use of synchrotron radiation microangiography to assess development of small collateral arteries in a rat model of hindlimb ischemia.

BACKGROUND: Current methods of angiography cannot provide images of arteries measuring < 200 microns in diameter. We have recently developed a new angiography system that uses monochromatic synchrotron radiation and a high-definition video system with a spatial resolution of 30 microns. In the present study, we applied this microangiography system to visualize small arteries in normal and ischemic rat limbs and investigated the development of collateral arteries. METHODS AND RESULTS: Microangiography was performed in the normal and the ischemic limb 4 weeks after the excision of the femoral artery. In the normal limb, up to the fourth branches of the iliac and/or femoral arteries (diameter < 100 microns) were readily identified. Some of these branches were found to perfuse the distal thigh area. In the ischemic limb, an extensive structural remodeling of the vascular network was observed. Numerous small arteries had developed from the branches of the iliac artery to constitute a fine arterial network, the so-called "midzone," which was composed of linear, normal appearing arteries and those with an undulating, unbranched appearance. CONCLUSIONS: The small collateral artery network was angiographically visualized with a resolution limit < 100 microns. The linear collaterals appeared to result from an opening of preexisting vessels. The undulating, unbranched vessels were not observed in the normal limbs and seemed to be vessels that were newly formed after limb ischemia. Synchrotron radiation microangiography appears to be a powerful means of assessing the development of small collateral arteries, which may help to provide a basis for understanding of the collateral circulation.

Angiography↗
PubMed1997

Small cell neuroendocrine carcinoma of the ovary.

A 64-year-old woman (gravida 0, para 0) had a unilateral ovarian mass measuring 14 cm in its greatest diameter, which was mostly solid. Microscopically, the tumour was characterized by two predominant proliferating patterns: a carcinoid-like pattern with trabecular, tubular, glandular, or insular arrangements and a closely packed nesting pattern with central coagulation necrosis and occasional glandular arrangements. These two patterns were intermingled, and numerous mitotic figures were present. Electron microscopy showed neurosecretory granules in the cells, which were argyrophilic and positive for neuroendocrine markers (chromogranin, leu 7, neuron-specific enolase, and synaptophysin). The tumour was aneuploid by flow cytometry. The patient received chemotherapy postoperatively, developed brain and multiple bone metastases and died of disease 10 months after surgery. This tumour must be distinguished from other small cell neoplasms, especially ovarian small cell carcinoma of the hypercalcaemic type.

Biomarkers↗
PubMed1997

Microangiographic assessment of collateral vessel formation following direct gene transfer of vascular endothelial growth factor in rats.

OBJECTIVE: The development of collateral microvessels following therapeutic angiogenesis with vascular endothelial growth factor (VEGF) was investigated using a new system of microangiography that employs monochromatic synchrotron radiation (SR) and a high definition video system to visualize arteries with a spatial resolution of 30 microns. METHODS: Ischemia was induced in the hindlimb of 20 rats by excision of the femoral artery, followed by transfection of the plasmid (400 micrograms) encoding VEGF or beta-galactosidase (control) into limb muscles. Microangiography was used to assess the development of collaterals in the ischemic limb four weeks after treatment. RESULTS: Gene transfer of VEGF produced morphologically similar, but significantly more extensive, collateral networks at the microvascular level as compared with the naturally occurring collateral arteries in the control animals (angiographic score: 0.88 +/- 0.08 versus 0.54 +/- 0.05, p < 0.01). No adverse vascular effects such as hemangiomas and/or arteriovenous (AV) fistulae were observed following VEGF treatment. The vasodilator effect of papaverine was evident in relatively large vessels in both groups. At the microvascular level (diameter < 100 microns), however, papaverine induced significant vasodilation in the VEGF-treated animals, and almost no vasodilation in the controls. CONCLUSIONS: SR microangiography allowed us to assess the development of small collateral arteries following VEGF-gene transfer. The information obtained may provide new insights regarding the collateral microcirculation and therapeutic angiogenesis.

Angiography↗
PubMed1997

Endometrial low-grade stromal sarcoma with ovarian sex cord-like differentiation: report of two cases with an immunohistochemical and flow cytometric study.

Two cases of endometrial low-grade stromal sarcoma with ovarian sex cord-like differentiation occurring in a 39-year-old woman and a 42-year-old woman are presented. Both tumors, which were intramyometrial and measured 7.5 cm and 7.0 cm in greatest diameter, respectively, showed a multinodular, ill-demarcated, and yellowish white cut-surface. Histologically, most parts of the tumors were composed of trabecular, cord-like, or plexiform arrangements that were reminiscent of the growth pattern seen in ovarian sex cord tumors. Features of conventional endometrial low-grade stromal sarcoma were only focally observed. The tumors showed infiltrative margins and lymphatic invasion. The tumor cells were positive for vimentin, desmin, alpha-smooth muscle actin, and muscle actin (HHF35). The tumors were also positive for both estrogen and progesterone receptors. Both tumors were DNA diploid as determined by flow cytometry. One patient had recurrences, including osteolytic lesions in the pelvic bones, but had no evidence of recurrence or metastasis 11 months after the last surgery. The other patient had no evidence of tumor in a limited follow-up. Familiarity with the neoplasm and other uterine mesenchymal tumors with ovarian sex cord-like differentiation by gynecologists and pathologists is essential in avoiding misdiagnosis because adjuvant hormonal therapy may be effective in treating low-grade stromal sarcomas.

Adult↗
PubMed1997

Columnar cell carcinoma of the thyroid.

A case of columnar cell carcinoma of the thyroid occurring in a 50-year-old female is described. Histologically, the 2 cm tumor showed a prominent papillary architecture with thin fibrous cores covered by columnar cells and marked nuclear stratification. It also showed microfollicular, glandular, and solid patterns. The nuclear features were different to those of conventional papillary carcinoma and similar to those of follicular tumors. The tumor was principally encapsulated with vascular and minimal capsular invasion. The tumor cells were positive for thyroglobulin. The tumor was DNA diploid with a low S phase traction as determined by flow cytometry. The patient had no lymph node or distant metastasis. The patient was well and without disease 9 months after surgery. The possibility that the neoplasm is one of poorly differentiated thyroid carcinomas rises.

Biomarkers, Tumor↗
PubMed1997

Fatty acid compositions of colostrum, cord blood, maternal blood and major infant formulas in Japan.

Lipid profiles in colostrum, cord blood, maternal blood and major infant formulas in Japan were analyzed. In the first part of the study, colostrum obtained from 36 normal delivery women and six kinds of infant formulas provided by three major milk companies were analyzed for their fatty acid composition using capillary gas-lipid chromatography. Although enriched with docosahexaenoic acid (DHA), the percent composition of DHA in the six infant formulas (0.15-0.21%) was significantly lower than that in the colostrum (1.1 +/- 0.54). Arachidonic acid (AA) and eicosapentaenoic acid (EPA) were present in the colostrum but not detectable in the infant formulas. It is recommended that although the exact amount of specific fatty acids needed in the infant diet was not completely known, to be as close as possible to natural breast milk, the level of DHA, EPA and AA should be raised in the infant formulas. In the second part of the study, 19 pairs of maternal and cord blood were analyzed for their lipid profile. All samples were from normal vaginal delivery. The measurement of cholesterol, triglycerides, phospholipids and free fatty acids was performed with commercially available enzymatic methods on an automated discrete random access analyzer. Total fatty acid was determined as described in the first part of the study. The results were analyzed with Spearman's rank correlation coefficient. No correlation could be found between maternal and fetal concentrations of cholesterol, triglycerides, phospholipids or total fatty acids. Correlation could be found in non-esterified fatty acids, in palmitic acids, and oleic acid levels. It was concluded that the lipid transport and metabolism in the fetal-placenta unit is complex and further delicate investigation is required.

Adult↗
PubMed1997

Amnesia following damage to the mammillary bodies.

It is not known whether lesions of the mammillary body per se can produce significant memory impairment in humans. The amnesia reported in patients with lesions in the mammillary bodies may have been produced by lesions coexisting in other memory-related areas, such as the medial thalamus, mammillothalamic tract, descending columns of the fornix, or amygdalofugal pathways. We describe a patient who developed anterograde amnesia following damage to the basal hypothalamus involving the mammillary bodies. The cause was a cystic craniopharyngioma. After surgical removal of the tumor, his memory function improved but remained considerably impaired, especially on delayed recall. Postsurgical MRI revealed small, atrophic mammillary bodies without residual tumor. There was no obvious evidence of damage to the hypothalamus. We therefore conclude that our patient's amnesia resulted from mammillary body lesions alone.

Amnesia↗
PubMed1997

[Laboratory diagnosis of congenital thrombophilia].

We examined the incidence of thrombophilia in deep vein thrombosis (DVT). Of 38 cases, we found 4 cases of protein C abnormality, 2 cases each of protein S abnormality and lupus anticoagulant, 1 case of antithrombin III abnormality. The total incidence was 23.7%, whereas only 2 cases (6.2%) of plasminogen abnormality were found among 32 healthy individuals. The incidence of thrombophilia was apparently higher among patients with DVT than that of healthy subjects, although the incidence of Japanese DVT was lower than that of Caucasian DVT, as previously reported. By SSCP analysis in one case of protein C abnormality, we demonstrated an abnormality of exon 9-3. To establish laboratory diagnosis of thrombophilia, it is recommended that (1) severe liver diseases, DIC, and oral anticoagulant be ruled out, (2) abnormality be confirmed by repeated examination, (3) family study determine inheritance mode, if possible. It was strongly suggested that laboratory examination of thrombophilia should be routinely applied to cases of venous thrombosis including DVT, not only for diagnostic interest but also for appropriate treatment of these cases.

Adult↗
PubMed1997

[Reasonable lymph node dissection for T2 or T3 midthoracic esophageal cancer with cervical lymph-node metastasis].

In order to determine the reasonable lymph node dissection for T2 or T3 midthoracic esophageal cancer with cervical lymph node metastasis, a retrospective study was carried out on 106 patients receiving resection between 1983 and 1996. Metastasis to cervical lymph node was obtained in 27.4% (29/106) of patients with T2 or T3 midthoracic esophageal cancer. Within 29 patients, metastasis in cervical node only, in two fields and in three fields occupied 17.2%, 41.4% and 41.4%, respectively. And according to the histologic examination of dissected lymph nodes, metastatic sites spreaded from neck to perigastric region. Five-year survival rate of 23 patients receiving curative operation was 33.0%, and that of 13 patients excluding 3-field metastasis was 51.9%. But the main sites of nodal recurrence were cervical or superior mediastinal nodes along the bilateral recurrent laryngeal nerves, and the rate of nodal recurrence was 47.8%. These results of actual state of lymph node metastasis and prognostic benefit of aggressive dissection suggest that 3-field lymph node dissection is mandatory for T2 or T3 midthoracic esophageal cancer with cervical lymph node metastasis. And we should endeavor to upgrade the precise dissection in order to decrease the nodal recurrence.

Esophageal Neoplasms↗
PubMed1996

Overexpression of cysteine sulfinic acid decarboxylase stimulated by hepatocarcinogenesis results in autoantibody production in rats.

We developed a novel and efficient cDNA subtraction method to isolate rat hepatocellular carcinoma (HCC)-related genes. cDNAs from Solt-Farber procedure-driven HCCs were synthesized on Latex beads. The subtraction was accomplished by a simple centrifugation, PCR amplification, and dot blot screening. Among 2000 clones from the subtracted cDNA library, one clone with a full-length HCC-related cDNA was eventually obtained. Sequence analysis of this clone showed it to exhibit 90 and 60% similarity with the rat cysteine sulfinic acid decarboxylase (CSAD) and mammalian glutamic acid decarboxylases (GAD), respectively. Differences between our sequence data on CSAD and those reported previously were observed at two positions, which arose from a single amino acid substitution and frame shift mutation. The CSAD expression was restricted to the liver and kidney of rats. During hepatocarcinogenesis, expression of the CSAD mRNA and its protein was stimulated in the precancerous liver and maintained its high expression afterward. Interestingly, a high level of anti-CSAD autoantibody was detected in the HCC-bearing rats. The titer of anti-CSAD autoantibodies in these rats was 30-200 times higher than that in normal rats. The anti-CSAD autoantibody appeared in the precancerous state and was maintained afterward, and its pattern of appearance was similar to that of CSAD mRNAs and proteins. Thus, we propose that the high-titer CSAD autoantibody resulted from increased CSAD gene expression in the liver due to stimulation by the HCC. These results remind us of human autoimmune diseases including insulin-dependent diabetes mellitus and stiff-man syndrome, which are caused by autoantibodies against GAD.

Amino Acid Sequence↗
PubMed1996

IFN-gamma-inducing factor up-regulates Fas ligand-mediated cytotoxic activity of murine natural killer cell clones.

NK cells, non-T non-B immune effector lymphocytes, are localized in many organs, including liver, as well as in the circulation. To investigate the regulatory mechanism of killing apparatus in hepatic NK cells, we established IL-2-dependent NK cell clones from liver lymphocytes of BALB/c nude mice. To generate the NK cell clones, we incubated liver lymphocytes with a high dose of IL-2 in the presence of irradiated Kupffer cells, as feeder cells and as the source of IL-12, originally identified as NK cell stimulatory factor. Unless liver lymphocytes were incubated with both IL-2 and Kupffer cells, no cell growth was observed. Hepatic NK cell clones were established from this cell line by limiting dilution. The surface phenotypes of cloned NK cells were IL-2R beta-chain+ CD16+ CD3- IgM-. The clones did not express NK2.1, which is expressed by a half of NK-enriched spleen cells of BALB/c mice. Although the cells contained dense granules reactive to mAb against perforin, they exerted no conventional cytolytic activity against YAC-1. They constitutively expressed Fas ligand (FasL) and specifically killed Fas-positive target cells by fragmenting DNA. This Fas-FasL-mediated killing activity was enhanced by IFN-gamma-inducing factor, a recently identified novel cytokine produced by activated Kupffer cells, but was not affected by other Kupffer cell-produced cytokines, such as IL-12, IL-1beta, and TNF-alpha. Taken together, these findings suggest that hepatic NK cells participate in the immune response as effector cells through the Fas-FasL system in collaboration with cytokines from Kupffer cells.

Animals↗