Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 379 records · Page 21Linked to original sources

PubMed1995

[Home enteral nutrition for the maintenance of remission in patients with Crohn's disease--including comparison between Elental and Enterued].

Therapeutic efficacy of Elental and Enterued as home enteral nutrition (HEN) for the maintenance of remission in 32 patients with quiescent Crohn's disease was studied retrospectively. Their cumulative rates of continuous remission and non hospitalization were statistically compared in relation to following five factors; type of disease, history of bowel resection, duration of disease, oral bile acid tolerance test (OBATT) and radiological lesion score (RLS). As to the cumulative rates of continuous remission and non hospitalization, there was no significant difference between two groups treated with Elental and Enterued. In patient with ileocolitis type, > or = 5-year history, and a high score of RLS, few cases could continuously maintain remission following a long-term HEN. Especially, patients with low absorption in OBATT had a significantly lower cumulative rate of continuous remission than those with normal absorption in OBATT. The present results suggest that above factors may be useful in the application of HEN to patients with Crohn's disease.

Adolescent↗

PubMed1995

[Brain stem glioma induced by radiotherapy: report of a case].

A case of brain stem glioma following radiotherapy for brain tumor is presented. A 44-year-old female was admitted with chief complaints of gait disturbance and disturbed consciousness. She had received radiation therapy with 60Gy following resection of a right temporal astrocytoma 20 years before, but until admission this time follow up CT scan had shown no regrowth. On admission CT scan and MRI showed an enhanced mass (2 x 2.5cm) in the mid-brain. Tumor biopsy was performed using the subtemporal approach. The histological diagnosis showed a fibrillary astrocytoma grade III. The patient received postoperative synchronized chemotherapy but expired 8 months after admission. The growth of glioma appeared in the previous radiation field after a long latent period. This case should be considered not as a case of the regrowth of a tumor but as a case of a radiation induced tumor. Although 77 cases of gliomas following radiation for intracranial tumor have been reported, this case of radiation-induced brain stem glioma is extremely rare.

Adult↗

PubMed1995

[Evaluation on the perioperative left ventricular function of aortic valve replacement in patients with chronic aortic regurgitation].

To evaluate the perioperative left ventricular function in 36 patients undergoing aortic valve replacement (AVR) in patients with isolated chronic aortic regurgitation (AR), hemodynamic variables before and within the first 24 hours and one month after operation were measured with Swan-Ganz catheter and echocardiography. The patients were divided into two groups based on preoperative left ventricular end-systolic volume index (LVESVI): 5 patients had a LVESVI of 90 ml/m2 and greater (group I), 31 had a LVESVI smaller than 90 ml/m2 (group II). Left ventricular dimension at end-diastole and end-systole, left ventricular end-diastolic volume index at one month after operation significantly decreased in comparison with that of preoperation. However, left ventricular ejection fraction in the two groups were not improved, and left ventricular mass index in group I did not decreased. On the other hand, changes of cardiac index, stroke volume index and left ventricular stroke work index within the first 24 hours after operation were not significantly different between the two groups. The incidence of postoperative premature ventricular contraction in group I was significantly higher than that of group II. However, there was no difficult problems in postoperative management of the two groups. It is suggested that AVR in AR with left ventricular dysfunction can safely be operated and its postoperative management is similar to AVR in AR with no left ventricular dysfunction.

Adult↗

PubMed1994

Tumor necrosis factor alpha production enhancers with a phenylphthalimide skeleton.

N-2,6-Dialkylphenylphthalimides were found to be strong enhancers of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor necrosis factor (TNF)-alpha production by human leukemia cell line HL-60. Among these compounds, 2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione (PP-33) showed the most potent activity (optimum concentration of 10 microM), indicating that the bulkiness of the alkyl groups at the 2 and 6-positions of the phenyl ring moiety is crucial for the activity. Its fluorinated derivative, 2-(2,6-diisopropylphenyl)-4,5,6,7-tetrafluoro-1H-isoindole-1,3-dio ne (FPP-33) showed the activity at very low concentrations (optimum concentration of 0.1 microM).

Humans↗

PubMed1994

No evidence of linkage or allelic association of schizophrenia with DNA markers at pericentric region of chromosome 9.

Based on our previous study suggesting the pericentric region of chromosome 9 as of potential importance in schizophrenia, we have carried out a linkage study between the schizophrenia phenotype and the dinucleotide repeat polymorphisms D9S55, D9S15, and D9S202 in three pedigrees multiply affected with schizophrenia. In addition, we have conducted allelic association studies using 60 patients with schizophrenia and 60 controls with polymorphisms at D9S55 and D9S15 markers. No evidence for linkage or association was found. The results indicate that susceptibility genes for schizophrenia are less likely to be located at the pericentric region of chromosome 9, assuming genetic homogeneity of the pedigrees.

Alleles↗

PubMed1994

Suppressive effect of basic fibroblast growth factor on transendothelial emigration of CD4(+) T-lymphocyte.

The effect of basic fibroblast growth factor (b-FGF), one of the commonest angiogenic factors in various cancer types, on lymphocyte adhesion and transmigration across the endothelial cell monolayer was investigated using human umbilical vein-derived endothelial cells (HUVEC) and type I collagen gel. Forty-eight h exposure of HUVEC with 2 ng/ml b-FGF significantly decreased the basal adhesion of lymphocytes to endothelial cells. The decrease ratio is further enhanced by the addition of shear stress in this assay system. When HUVEC was stimulated for the last 24 h with optimal conditions of recombinant interleukin 1 beta, the percentages of transmigration as well as adhesion were also decreased significantly by the presence of b-FGF. The expression of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 was down-regulated by b-FGF exposure in both resting and activated conditions by recombinant interleukin 1 beta, supposedly the main reason for this phenomenon. The migrating cells across b-FGF-stimulated HUVEC contained a markedly lower percentage of CD4(+) T-cells than those across non-treated HUVEC, although the 4B4(+)/2H4(+) ratio in CD4(+) T-cell populations did not differ significantly. These facts suggest that the presence of b-FGF in the angiogenic area suppresses lymphocyte emigration, especially that of CD4(+) T-cells, and thus causes insufficient helper function in local immune response. This effect of b-FGF was possibly one of the critical mechanisms by which cancer cells escape from the host immune reactions in the angiogenic stage of tumor development.

CD4-Positive T-Lymphocytes↗

PubMed1994

Thyroid diseases among atomic bomb survivors in Nagasaki.

OBJECTIVE: To elucidate the current thyroid disease status for the Nagasaki Adult Health Study cohort of the Radiation Effects Research Foundation. DESIGN: Survey study. SETTING: Nagasaki, Japan. PARTICIPANTS: Cohort members of the Nagasaki Adult Health Study who received biennial health examinations from October 1984 to April 1987 (n = 2856). A total of 2587 subjects remained after exclusion of persons exposed in Hiroshima or in utero and those who were not in Nagasaki at the time of the bombing. Thyroid radiation dose by the dosimetry system established in 1986 was available for 1978 of the 2587 subjects. MAIN OUTCOME MEASURES: Thyroid diseases were diagnosed using uniform procedures including ultrasonic scanning. The relationship of the prevalence of each thyroid disease with thyroid radiation dose, sex, and age was analyzed using logistic models. RESULTS: A significant dose-response relationship was observed for solid nodules, which include cancer, adenoma, adenomatous goiter, and nodules without histological diagnosis, and for antibody-positive spontaneous hypothyroidism (autoimmune hypothyroidism) but not for other diseases. The prevalence of solid nodules showed a monotonic dose-response relationship, yet that of autoimmune hypothyroidism displayed a concave dose-response relationship reaching a maximum (+/- SE) level of 0.7 +/- 0.2 Sv. CONCLUSIONS: The present study confirmed the results of previous studies by showing a significant increase in solid nodules with dose to the thyroid and demonstrated for the first time a significant increase in autoimmune disease among atomic bomb survivors. A concave dose-response relationship indicates the necessity for further studies on the effects of relatively low doses of radiation on thyroid disease.

Cohort Studies↗

PubMed1994

Macrophage colony-stimulating factor-induced bone marrow macrophages do not synthesize or release prostaglandin E2.

Previously, we found that murine bone marrow-derived macrophages (MO) induced in vitro by MO-specific colony-stimulating factor (M-CSF) have little capacity to release prostaglandin E2 (PGE2) and other eicosanoids. This work focused on the functional and transcriptional expression of the key enzymes for the PGE2 synthesis in the MO. Nonadherent bone marrow cells were cultured with RPMI1640 plus 10% fetal bovine serum (FBS) further supplemented with either M-CSF or granulocyte-macrophage (GM)-CSF and interleukin-3 (IL-3). Cellular PGG/H synthase (cyclooxygenase) levels were quantified by cytometric analysis with antibodies specific for the two isozymes of PGG/H synthase (PGG/H synthases 1 and 2). The enzyme activity was monitored by adding exogenous arachidonic acid (AA) substrate to the bone marrow MO cultures and to the cell-free particulate fractions. The levels of PGE2 converted were quantitated by radioimmunoassay (RIA). mRNA levels of the enzymes were detected by Northern blot analysis hybridized with mouse PGG/H synthase cDNA probes, 2.7 kb (PGG/H synthase 1) and 4.2 kb (PGG/H synthase 2). In addition, cellular phospholipase A2 (PLA2) activities were detected with sn-2-14C-arachidonyl phosphatidylcholine as a substrate. Cells proliferating in the presence of GM-CSF and IL-3 for more than 4 days showed significant release of PGE2 (> 7 ng/10(6) cells) when stimulated by AA. These cells also expressed significant amounts of PGG/H synthase 1 protein, its mRNA (2.7 kb) and cellular PLA2. M-CSF-induced MO, in sharp contrast, expressed little PGG/H synthase protein, mRNA, cellular enzyme activity, or PGE2 release, despite comparable levels of cellular PLA2 activity. These data suggest that the capacity of differentiating marrow-derived MO to form PGE2 is growth factor-dependent.

Animals↗

PubMed1994

Coronary atherosclerotic smooth muscle cells overexpress human parathyroid hormone-related peptides.

Parathyroid hormone-related peptide (PTHrP) was originally characterized as a tumor product responsible for hypercalcemia of malignancy and was subsequently found to be produced in many normal tissues. PTHrP is now suggested to play a critical role in the local modulation of vascular smooth muscle function. To elucidate the involvement of PTHrP in coronary atherosclerosis, we immunohistochemically examined coronary arteries obtained from 76 patients with various grades of atherosclerosis and compared the correlation between PTHrP staining and the percent stenosis. Smooth muscle cells at sites of coronary atherosclerosis overexpressed PTHrP, while cells from normal coronary arteries did not. The in situ hybridization using PTHrP riboprobe has also proven the overexpression of PTHrPmRNA in the affected lesions following atherectomy. The intensity of PTHrP expression by smooth muscle cells was significantly correlated with the degree of coronary artery stenosis. Coronary arterial PTHrP overexpression is closely related to the severity and/or progression of coronary atherosclerosis.

Adult↗

PubMed1994

Analysis of risk factors for post-transfusion graft-versus-host disease in Japan. Japanese Red Cross PT-GVHD Study Group.

We distributed a questionnaire to highlight the effects of post transfusion graft-versus-host disease (PT-GVHD) and to elucidate the risk factors that would predispose people to the disease. The questionnaire described the pathogenesis and the clinical profiles of PT-GVHD and was distributed to doctors in Japan whose hospital conducted more than 1000 units of blood transfusions a year. Doctors were asked about their awareness and experience of PT-GVHD cases. Those who had seen cases of PT-GVHD were then asked to detail clinical course and laboratory data. Of the 14,083 doctors who replied to the first question, 47.4% did not realise that PT-GVHD could occur in immunocompetent hosts. From 304 cases where detailed information was supplied, 171 were considered clinically compatible with PT-GVHD. From these it seems that the risk factors linked to PT-GVHD are cardiovascular surgery, cancer, fresh and consanguineous blood transfusion, and being male. Patients with any of these factors should have some prophylactic therapy such as irradiation of blood before transfusion.

Adolescent↗

PubMed1994

A new mutation, aly, that induces a generalized lack of lymph nodes accompanied by immunodeficiency in mice.

We have found a new spontaneous autosomal recessive mutation in mice that causes a systemic absence of lymph nodes and Peyer's patches. The name "alymphoplasia", with the gene symbol "aly", is proposed for this mutant. The spleen of aly/aly mice is devoid of well-defined lymphoid follicles, and the thymus does not show a clear cortical-medullary distinction. The mutant homozygotes are deficient in both humoral and cell-mediated immune functions, and are highly susceptible to infections. They have a reduced level of IgM and severely depressed levels of IgG and IgA in their sera, and do not reject allogeneic skin grafts. However, they have mature T and B cells as determined from their cell surface antigens. The results of bone marrow transplantation experiments suggest a mesenchymal disorder as a possible cause of the lack of lymph nodes and of immunodeficiency in the aly mouse. The aly mutant mouse may be a useful animal model of primary immunodeficiency, as are the nu (nude) and scid (severe combined immunodeficiency) mice.

Animals↗

PubMed1994

Stimulation of interleukin-6 production of periodontal ligament cells by Porphyromonas endodontalis lipopolysaccharide.

Interleukin-6 (IL-6), which is a multifunctional cytokine, has important roles in acute and chronic inflammation and may also be implicated in bone resorption. We examined the IL-6 production in periodontal ligament (PDL) cells which were treated with lipopolysaccharide (LPS) from several oral inflammatory pathogens. The LPS from Porphyromonas endodontalis, which was isolated from infected root canals and radicular cyst fluids, was more potent than the LPS from any other periodontal organisms examined. P. endodontalis LPS stimulated IL-6 release from PDL cells in a time- and dose-dependent manner. Northern blot hybridization analysis revealed that the IL-6 mRNA level in PDL cells was increased by P. endodontalis LPS. These results suggest that stimulation of the IL-6 release of PDL cells by P. endodontalis LPS may have a role in the progression of inflammation and alveolar bone resorption in periodontal and periapical diseases.

Blotting, Northern↗

PubMed1994

MRI contrast enhancement by Gd-DTPA-monoclonal antibody in 9L glioma rats.

To achieve a tissue-specific enhancement in diagnosis of brain tumor, a magnetic resonance imaging (MRI) study was performed using conjugate of Gd-DTPA and monoclonal antibody (MoAb) against 9L glioma cells. Fisher 344 strain rats were used for this study. MoAb against 9L glioma cells was conjugated with Gd-DTPA according to the method of Hnatowich et al. (1983) and used for the MRI study. The gadolinium (Gd) concentration in the Gd-MoAb injected to the rats was 0.01-0.03 mmol/kg. The enhancement effect increased gradually and persisted for 24 hours after the injection. This was longer than Gd-DTPA, which showed a peak of enhancement effect within 30 minutes after injection and was washed out within 120 min. This result was compatible with scintigraphy studies using 125I labeled anti 9L monoclonal antibody, in which the accumulation of the 125I antibody increased at 24, 48 and 72 hours after the injection. By using tumor-specific contrast agents such as Gd-MoAb, it may be possible to differentiate among tumor, perifocal edema and radiation injury.

Animals↗

PubMed1994

Long-term results of primary closure for ventricular septal defects in the first year of life.

The long-term results of primary closure for large ventricular septal defects (VSDs) in infants under 1 year of age with severe symptoms were studied over a period of more than 10 years. Between January, 1971 and March, 1982, 49 infants underwent primary closure of a VSD through a right ventriculotomy using complete cardiopulmonary bypass with mild hypothermia. There were four hospital deaths but no late deaths. Two of four infants with residual shunts had a left ventricular-right atrial shunt which necessitated reoperation. Surgical heart block occurred in two infants who recovered sinus rhythm in the late period. The cardiothoracic ratio decreased from 60.5% preoperatively to 50.6% in the late postoperative period. Examination by cardiac catheterization revealed that the pulmonary-to-systemic pressure ratio (Pp/Ps) of 23 patients with a Pp/Ps of over 0.75 fell from 0.89 +/- 0.09 preoperatively to 0.42 +/- 0.12 by 1 month postoperatively, then to 0.27 +/- 0.05 in the late postoperative period. The latest values for the cardiac index and left ventricular ejection fraction were 3.4 l/min per m2 and 64.4%, respectively. More than 10 years after their operation, all the survivors were growing normally and maintaining a good quality of life, which supports our recommendation that primary repair should be performed in the first year of life for infants with large VSDs.

Bundle-Branch Block↗

PubMed1994

Lysis of endothelial cells by autologous lymphokine-activated killer cells.

The mechanisms of lysis of endothelial cells derived from human umbilical vein (HUVEC) by autologous lymphokine-activated killer (LAK) cells, generated from cord blood lymphocytes of the same donor, were investigated. Freshly isolated HUVEC as well as HUVEC cultured for several passages were efficiently lysed by autologous LAK cells, and their susceptibility to the LAK cells was almost the some as that of allogenic HUVEC. Complement-depletion experiments revealed that the lysis was mainly dependent on CD16+ natural killer (NK) LAK cells. pretreatment of HUVEC with recombinant interferon gamma (rIFN gamma) for 24 h made them resistant to lysis by autologous LAK cells, while pretreatment with either rIL-1 beta. rTNF alpha, or acidic or basic fibroblast growth factor did not alter the lytic sensitivity of HUVEC. The resistance of rIFN gamma-treated HUVEC was specific to lysis by CD16+ NK LAK cells, and their lysis by CD3+ T-LAK cells was not significantly altered. Moreover, in comparison with control HUVEC or rIL-1 beta-treated HUVEC, rIFN gamma-treated HUVEC had a significantly less potent inhibitory effect on the lysis of untreated HUVEC, when used as an unlabeled target. This suggests that rIFN gamma treatment may down-regulate the recognition of some molecules on HUVEC by rIL-2-activated NK cells. These data suggest that damage of the endothelium during LAK therapy is mainly dependent on LAK cells with a NK phenotype that can specifically recognize a certain molecule on autologous endothelial cells.

CD3 Complex↗

PubMed1994

A case of toxic megacolon in ulcerative colitis associated with cytomegalovirus infection.

Cytomegalovirus (CMV) infection, which has been shown to complicate the course of ulcerative colitis (UC), has been implicated as a possible etiologic factor in the exacerbation of UC, especially in toxic megacolon. However, CMV infection in patients with UC accompanied by toxic megacolon has rarely been reported. Here we report a case of CMV infection of the colon accompanied by toxic megacolon occurring in UC. A 38-year-old woman had been treated with intravenous hydrocortisone, rectal steroid, and central venous alimentation for 6 weeks under the diagnosis of UC. She was transferred to Akita University Hospital because of increasing bloody diarrhea and abdominal pain. Toxic megacolon was identified by examinations on admission, and she underwent a total colectomy. Examination of the surgical specimen showed severe inflammation of the colon. Microscopically, cytomegalic inclusions were observed in and around the endothelial cells in the inflamed submucosal layer. It can be assumed that CMV infection was a secondary, opportunistic invader superimposed on UC, and that it played an important role in altering the clinical course of the patient.

Adult↗

PubMed1994

Immunocytochemical studies of major gap junction proteins in rat salivary glands.

We examined protein components of the gap junctions between acinar cells of the parotid, sublingual and submandibular glands of the rat, using type-specific antibodies directed against major gap junction proteins, connexin32 (Cx32) and connexin26 (Cx26). Double-immunofluorescence microscopy revealed that fluorescent spots of both connexins in the parotid and sublingual glands were distributed between the apposed regions of acinar cells. They appeared together, or were co-localized. The intensity of the Cx26-associated fluorescent signals was relatively weak in the submandibular glands compared with the other glands and was absent from some acini. When present, these spots were always co-localized with Cx32 immunoreactive positive spots. The results suggest that Cx32 and Cx26 in rat salivary glands are colocalized within the same gap junctional plaques when simultaneously expressed by the same acinar cells.

Animals↗

PubMed1994

Effect of different magnitudes of tension force on prostaglandin E2 production by human periodontal ligament cells.

Periodontal ligament (PDL) cells are known to produce prostaglandin E2 (PGE2) in response to mechanical stress. However, the rate of PGE2 production from PDL cells in response to different magnitudes of tension forces has not been examined. This study, therefore, was undertaken to determine the effect of different magnitudes of tension forces on PGE2 production and inositol trisphosphate (IP3) levels in PDL cells in vitro. Human PDL cells were cultured on flexible-bottomed plates and placed on a Flexercell strain unit. Cells were flexed at six cycles (5-s strain, 5-s relaxation) at six steps of tension force (9, 12, 15, 18, 21, 24% increase in surface area) for 5 days. PGE2 production and IP3 levels were determined by radioimmunoassay. There was a 6- and 25-fold increase in the rate of PGE2 production by cells exposed to low (9%) and high (24%) tension forces, respectively, and these increases were tension force-dependent. Tension force also induced increases in the intracellular levels of IP3 that did not seem to be directly related to the production of PGE2. The different rates of PGE2 production by PDL cells in response to different magnitudes of mechanical stress may be of importance in PDL and alveolar bone metabolism.

Adult↗