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Biomedical subjects

T Miyazaki

Publications and source records attributed to T Miyazaki.

At least 55 records · Page 3Linked to original sources

Recombinant forms of glycophorin C as a tool for characterization of epitopes for new murine monoclonal antibodies with anti-glycophorin C specificity.

Glycophorin C (GPC) and glycophorin D (GPD) are minor but important components of human RBC membranes. They carry the high-frequency antigens Ge2, Ge3 and Ge4 of the Gerbich blood group system. The epitopes for five new monoclonal antibodies (MoAbs) with anti-GPC specificity were characterized. Two antibodies (4G11 and 5B11) reacted with glycosylated N-terminal epitopes, and three reacted with internal epitopes of GPC. Pepscan analysis showed that the MoAb RB11 required for binding the EPDP sequence, occurring twice in GPC polypeptide chain. The MoAb 7F11 recognized the sequence 13PLSLEPDP20, and the MoAb RB8 did not react with synthetic peptides. Further characterization of the internal epitopes was performed in fluorescence-activated cell sorter (FACS) with the use of recombinant GPC and its variant forms transiently expressed on COS-7 cells. The results indicated that the MoAb RB11 recognized distinctly its target sequence EPDP only in a normal GPC molecule. The reactivity of the MoAb 7F11 with the PLSLEPDP sequence was confirmed and found to be enhanced by the O-glycan at the Ser15 residue. The MoAb RB8 recognized the glycopeptidic epitope in proximity to the Ser15 residue, requiring the presence of O-glycan. The combination of immunochemical techniques with the use of the recombinant forms of GPC has made it possible to define the role of sugar chains in the recognition of peptidic epitopes in glycosylated antigen and sheds new light on the Gerbich system antigens.

Amino Acid Sequence↗

Seven-day triple therapy with omeprazole, amoxycillin and clarithromycin for Helicobacter pylori infection in haemodialysis patients.

BACKGROUND: Triple therapy is accepted as the treatment of choice for Helicobacter pylori eradication, but there is no consensus on how long the therapy should be maintained in haemodialysis (HD(+)) patients. Our aims in this study were to evaluate the safety and efficacy of the 7-day triple therapy in HD(+) patients. METHOD: Forty-seven HD(+) and 55 HD(-) patients with dyspepsia underwent endoscopy. The prevalence of H. pylori was detected by Giemsa stain, followed by the urea breath test (UBT). H. pylori(+) patients were scheduled to undergo 7-day triple therapy and the success of eradication was investigated by UBT. RESULTS: Forty-five (44%) patients were positive for H. pylori. Forty of them underwent triple therapy and 39 (98%) patients completed the treatment. Eradication was successful in 32 (82%) and unsuccessful in 7 (18%) patients. There was no significant difference between these groups in age, gender, endoscopic findings or HD, and only previous treatment was significant for eradication failure by univariate and multivariate logistic regression analysis. Side effects were observed in 2 (15%) of 13 HD(+) and 3 (11%) of 27 HD(-) patients, and one HD(-) patient had to stop medication because of severe nausea and vomiting. The eradication rate was 93% (28/30) in patients without previous treatment. The triple therapy was unsuccessful in 7 patients, and 4 of them again underwent 7-day triple therapy, but all resulted in failure. CONCLUSIONS: Seven-day triple therapy is safe and effective for primary treatment of H. pylori infection in both HD(+) and HD(-) patients, but a new treatment is necessary for patients with previous treatment.

Age Factors↗

Dynamic load at baseline can predict radiographic disease progression in medial compartment knee osteoarthritis.

OBJECTIVE: To test the hypothesis that dynamic load at baseline can predict radiographic disease progression in patients with medial compartment knee osteoarthritis (OA). METHODS: During 1991-93 baseline data were collected by assessment of pain, radiography, and gait analysis in 106 patients referred to hospital with medial compartment knee OA. At the six year follow up, 74 patients were again examined to assess radiographic changes. Radiographic disease progression was defined as more than one grade narrowing of minimum joint space of the medial compartment. RESULTS: In the 32 patients showing disease progression, pain was more severe and adduction moment was higher at baseline than in those without disease progression (n=42). Joint space narrowing of the medial compartment during the six year period correlated significantly with the adduction moment at entry. Adduction moment correlated significantly with mechanical axis (varus alignment) and negatively with joint space width and pain score. Logistic regression analysis showed that the risk of progression of knee OA increased 6.46 times with a 1% increase in adduction moment. CONCLUSIONS: The results suggest that the baseline adduction moment of the knee, which reflects the dynamic load on the medial compartment, can predict radiographic OA progression at the six year follow up in patients with medial compartment knee OA.

Aged↗

Anode glow discharge plasma treatment enhances calcium phosphate adsorption onto titanium plates.

Glow discharge plasma (GDP) supplied to a cathode (GDP-) has been applied for cleaning, surface activating, and sterilizing biomaterials, because the kinetic energy in the case of the GDP- is larger than that supplied to the anode (GDP+). However, no comparison between GDP+ and GDP- has been reported. In this study, a titanium surface pre-treated with GDP+ and GDP- was characterized by x-ray photoelectron spectroscopy (XPS). In addition, the wettability of the titanium surface was measured with and without GDP. Furthermore, XPS characterized the adsorption of inorganic ions on titanium surfaces with and without GDP and immersed in an electrolyte solution. The findings suggested that GDP+ enhances calcium phosphate nucleation, due to the accumulation of electrons. In addition, calcium phosphate was not nucleated on the specimen with GDP-. We conclude that GDP+ is more suitable for biomineralization on titanium.

Adsorption↗

Recovery process of arthritis induced by 6-sulfanilamidoindazole (6SAI) in rats.

6-Sulfanilamidoindazole (6SAI) is known to induce not only an acute arthritis but also serositis and arteritis which resemble those induced by some vasodilators in rats. In this study, the recovery process of ankle lesions was examined histopathologically for up to 12 weeks of recovery period in rats bearing arthritis induced by administration of 6SAI (500 mg/kg) for 2 weeks. At 2 weeks of 6SAI-treatment, exudative synovitis and exudative/edematous periarthritis with marked formation of granulation tissues and periosteal reactive bone formation were noted in the ankles, but no remarkable neutrophil infiltration was detected in those lesions. The ankle swelling induced by 6SAI diminished by 4 weeks of recovery period, and the elevated plasma fibrinogen levels were normalized by 2 weeks of recovery period. Although fibrosis and newly-formed periosteal bone were still observed after 2 weeks of recovery period, no inflammatory lesion was detected at that point. At 4 or 12 weeks of recovery periods, the ankles showed an almost normal appearance. These results indicate that 6SAI-induced arthritis is reversible in nature and does not develop into chronic phase.

Acute Disease↗

c-Ets1 is a promising marker in epithelial ovarian cancer.

c-Ets1 controls the expression of some genes involved in extracellular matrix remodeling. To elucidate the involvement of c-Ets1 in epithelial ovarian carcinogenesis, we investigated the role of the proto-oncogene c-ets1 in the regulation of physiological processes such as cell proliferation, differentiation, and tumor invasion. Using fluorescent immunohistochemistry, we analyzed serial frozen sections for c-Ets1 protein expression in 26 patients with ovarian epithelial carcinoma, 10 patients with benign cystadenoma of the ovary, and 10 premenopausal patients with normal ovaries. We analyzed the relationship between the percentage of c-Ets1 stained cells in a patient and characteristics of the patient including histological classification, clinical stage, histological grade, and clinical outcome. c-Ets1 was not detected in any cases of benign ovarian cystadenoma. Most of the c-Ets1 proteins were found in the cytoplasm and some in the nucleus of epithelial ovarian cancer tissues. Moreover, c-Ets1 was strongly expressed in the head portion of papillary cancer tissues that had invaded the stroma. c-Ets1 expression was significantly associated with clinical stage (p<0.01), histological grade (p<0.01), and clinical outcome (p<0.01). Survival data were available for all patients and univariate Cox regression analysis showed that c-Ets1 expression was significantly associated with a poor prognosis (p<0.05). Our results demonstrate that c-Ets1 expression in epithelial ovarian cancer correlates to the malignant potential of the tumor.

Biomarkers, Tumor↗

[Long-term results of aortic arch replacement using combination of deep hypothermic circulatory arrest and retrograde cerebral perfusion; comparison of result for atherosclerotic aneurysm and aortic dissection].

Between 1992 and 2001, 73 patients with aortic arch lesion underwent surgical treatment. The aneurysm was characterized by atherosclerosis in 54 patients (TAA) and by aortic dissection in 19 patients (DAA). All patients received graft replacement under combination of deep hypothermic circulatory arrest and retrograde cerebral perfusion. The hospital mortality rate for all patients was 15.6%. The follow-up period of 61 survival patients ranged from 2 to 90 months (mean 33.2 months). The actuarial survival rate was 93.2%, 83.5%, and 79.7% at 1, 3, and 5 years, respectively. No significant difference was noted between TAA and DAA in the actuarial survival rate. The freedom from vascular complication was 97.9%, 95.8%, and 95.8% at 1, 3, and 5 years, respectively. The rate was significant higher in the patients of DAA than in those of TAA (TAA: 100%, 100%, and 100%, DAA: 90.9%, 81.8%, and 81.8%). The freedom from cardiac complication was 96.4%, 89.7%, and 84.1% at 1, 3, and 5 years, respectively. There was no significant difference between TAA and DAA. The freedom from cerebrovascular complication was 100%, 97.6%, and 83.4% at 1, 3, and 5 years, respectively. No significant difference was noted between TAA and DAA. The late result of surgical treatment for the aortic arch using combination of deep hypothermic circulatory arrest and retrograde cerebral perfusion was satisfied. The long-term survival rate was higher in TAA patient than in DAA one. The possibility remained that fatal vascular complication affected the long-term survival rate.

Aged↗

Exhaled nitric oxide decreases during exercise-induced bronchoconstriction in children with asthma.

Nitric oxide (NO) produced in the airways can be either detrimental or protective to the host. To investigate the role of NO in the pathogenesis of exercise-induced bronchoconstriction (EIB), we measured exhaled NO (ENO) after exercise challenge in 39 asthmatic and six normal children. FEV(1) and ENO were measured before and at 0, 5, 10, and 15 min after exercise performed on a treadmill for 6 min. EIB was defined as a decrease in FEV(1) of more than 15% after the exercise. Normal children (control group) did not have EIB. Twenty-one patients with asthma had EIB (EIB group) whereas the remaining 18 patients did not (non-EIB group). The baseline ENO value was significantly higher in the asthmatic children than in the normal children, and there was a positive correlation between the maximal percent decrease in FEV(1) and the baseline ENO value (r = 0.501, p = 0.012). At the end of the exercise, ENO had decreased in all the subjects. In the non-EIB and control groups, ENO rebounded to above the baseline at 5 min after the exercise and thereafter. In contrast, ENO remained at a decreased level in the EIB group. The change in ENO did not correlate with the change in minute ventilation, and beta-agonist inhalation at the peak of EIB that accelerated the recovery of FEV(1) did not affect the depressed level of ENO, demonstrating that the reduction of ENO is not a simple consequence of increased ventilation nor airway obstruction. Among the EIB group, steroid-treated patients showed sooner recovery in ENO after the exercise than steroid-naive patients. Our study suggests that NO production in response to exercise may be impaired in patients with EIB, and that ENO represents not only airway inflammation but also a protective function of NO in EIB.

Administration, Inhalation↗

An outbreak of VHSV (viral hemorrhagic septicemia virus) infection in farmed Japanese flounder Paralichthys olivaceus in Japan.

A rhabdoviral disease occurred in farmed populations of market sized Japanese flounder (hirame) Paralichthys olivaceus in the Seto Inland Sea of Japan in 1996. The causative agent was identified as viral hemorrhagic septicemia virus (VHSV) based on morphological, immunological, and genetic analyses. Diseased fish that were artificially injected with a representative virus isolate showed the same pathological signs and high mortality as observed in the natural outbreak. This is the first report of an outbreak of VHSV infection in cultured fish in Japan. Clinical signs of diseased fish included dark body coloration, an expanded abdomen due to ascites, congested liver, splenomegaly, and a swollen kidney. Myocardial necrosis was most prominent and accompanied by inflammatory reactions. Necrotic lesions also occurred in the liver, spleen and hematopoietic tissue, and were accompanied by circulatory disturbances due to cardiac failure. Hemorrhagic lesions did not always appear in the lateral musculature. Transmission electron microscopy revealed many rhabdovirus particles and associated inclusion bodies containing nucleocapsids in the necrotized myocardium. The histopathological findings indicated that the necrotizing myocarditis could be considered a pathognomonic sign of VHSV infection in Japanese flounder.

Animals↗

Development and release characterization of hyaluronan-doxycycline gels based on metal coordination.

A simple mixing with hyaluronan (HA), doxycycline (DC) and divalent metal cation in an aqueous solution enabled a thermoreversible water-soluble gel to form. For the cross-linking, two kinds of interactions were supposed. One was an electrostatic interaction between a positively charged group in DC and a negatively charged carboxyl function of HA, and the other was a chelation at the phenolic diketone moiety in DC. Since the gel was formed physically, the critical polymer concentration for gelation was present, and it was about 0.05% for HA with a molecular weight of 1.6x10(6). The hydrogel would be formed holding water in the HA entanglement network when DCs on HA chains made coordinate bonds through metal chelation. By changing the mixing ratio, two types of gels with different characteristics in drug release could be prepared. One was a gel with zero-order release prepared by mixing the same amount of HA and DC in equivalent. The other was a gel indicating Fickian diffusion-type release by mixing more DC than HA. Further, by controlling the absolute concentration of HA and DC, or the molecular weight of HA, some gels with desired release profiles could be prepared.

Algorithms↗

Glycated high-density lipoprotein induces apoptosis of endothelial cells via a mitochondrial dysfunction.

Glycation of plasma proteins may contribute to an excess risk of developing atherosclerosis in patients with diabetes mellitus. Although it is believed that high-density lipoprotein (HDL) is nonenzymatically glycosylated at an increased level in diabetic individuals, little is known about a possible linkage between glycated HDL and endothelium dysfunction in diabetes. This study set out to clarify whether glucose-modified HDL affects the function of endothelial cells by examining the apoptosis of cultured human aortic endothelial cells (HAECs) exposed to a glycated-oxidized HDL (gly-ox-HDL) prepared in vitro. Incubation of HAECs with 100 microg/ml of gly-ox-HDL for 48 h showed apoptotic features, such as cell shrinkage, membrane blebbing, and concentration and fragmentation of the nucleus, and the degree of apoptosis was dose-dependent on the glucose used in the preparation of gly-ox-HDL. Stimulation of HAECs with gly-ox-HDL elicited a marked increase in caspase 3 activity and the expressions of active caspase 3 and caspase 9, whereas concomitant treatment with a caspase 3 inhibitor significantly blocked gly-ox-HDL-induced apoptosis of HAECs. The release of cytochrome c into cytosols markedly increased in HAECs during the treatment with gly-ox-HDL. The increased expressions of Bax and Bad were detected in HAECs incubated for 24 h with gly-ox-HDL, but gly-ox-HDL failed to interfere with the expression of Bcl-2 and Bcl-x. Moreover, in vitro experiments with HDL (gly-HDL) glycated in the presence of 2 mM EDTA and Cu(2+)-oxidized HDL suggested that the apoptotic effect of gly-ox-HDL on endothelial cells might be due to an additional oxidative modification of gly-HDL. Taken altogether, additional oxidation of HDL under hyperglycemic conditions may induce endothelial apoptosis through a mitochondrial dysfunction, following the deterioration of vascular function.

Aorta↗

Polo-like kinase (PLK) expression in endometrial carcinoma.

Polo-like kinase (PLK) is a cell cycle-regulated, cyclin-independent serine/threonine protein kinase. Recent reports have shown a critical role for PLK during tumorigenesis. To explore whether PLK plays a general role as a tumor marker of endometrial carcinomas, we examined the expression of PLK mRNA and protein in endometrial carcinomas and normal endometrium, and analyzed the relationship between PLK protein expression and malignant potential. We found that PLK mRNA was expressed in all specimens from endometrial carcinoma patients using RT-PCR methods, although some specimens from normal endometria were negative. Immunohistochemically, most of the PLK was found in the cytoplasm (around the nucleus), and partly in the nucleus of endometrial carcinoma glands and also secreted tissues from endometrial carcinoma glands. PLK was expressed at the basement membrane of carcinoma glands and partly expressed in the head portion of papillary carcinoma tissues. There was a significant correlation between percentages of PLK-positive cells and histological grade of endometrial carcinoma (P<0.0001). However, the expression of proliferating cell nuclear antigen and Ki-67 was independent of PLK expression. Moreover, we noted that PLK is strongly expressed in invading carcinoma cells. PLK expression could reflect the degree of malignancy and proliferation in endometrial carcinoma. Thus, in addition to being of diagnostic value, modulation of PLK activity in the tumors by chemotherapeutic agents or gene therapy may prove to be of therapeutic value.

Adult↗

Fatal propionic acidemia in mice lacking propionyl-CoA carboxylase and its rescue by postnatal, liver-specific supplementation via a transgene.

Propionic acidemia (PA) is an inborn error of metabolism caused by the genetic deficiency of propionyl-CoA carboxylase (PCC). By disrupting the alpha-subunit gene of PCC, we created a mouse model of PA (PCCA(-/-)), which died in 24-36 h after birth due to accelerated ketoacidosis. A postnatal, liver-specific PCC expression via a transgene in a far lower level than that in wild-type liver, allowed PCCA(-/-) mice to survive the newborn and early infant periods, preventing a lethal fit of ketoacidosis (SAP(+)PCCA(-/-) mice). Interestingly, SAP(+)PCCA(-/-) mice, in which the transgene expression increased after the late infant period, continued to grow normally while mice harboring a persistent low level of PCC died in the late infant period due to severe ketoacidosis, clearly suggesting the requirement of increased PCC supplementation in proportion to the animal growth. Based on these results, we propose a two-step strategy to achieve an efficient PA prevention in human patients: a partial PCC supplementation in the liver during the newborn and early infant periods, followed by a larger amount of supplementation in the late infant period.

Animals↗

Expression of p53 protein related to smoking and alcoholic beverage drinking habits in patients with esophageal cancers.

In esophageal squamous cell carcinoma (SCC), we used immunohistochemical analysis to further elucidate the correlation of p53 protein expression with clinicopathological factors, as well as with risk factors, such as tobacco smoking, alcohol consumption and a family history of cancer, using odds ratios (ORs). The expression of p53 protein was demonstrated in 55.1% of 89 esophageal SCC cases examined by immunohistochemistry. The expression of p53 protein did not correlate with gender, age, histological grading, lymph node metastasis, or TNM stage. The prevalence of p53 expression was significantly higher in patients with multiple primary esophageal cancers (P<0.05). p53 expression did not correlate with prognosis in univariate survival analysis. The esophageal SCC in either smokers or alcohol users was 4.67-5.83 times more likely to express p53 protein, while the likelihood of p53 expression in patients who use both tobacco and alcohol was more than 14.0 times. However, a significant association was not found between p53 expression and a family history of cancer, this having an OR as low as 1.85. The expression of p53 protein did not correlate with clinicopathological factors and prognosis in univariate and multivariate survival analyses. In contrast, tobacco smoking and alcohol consumption were shown to be strongly associated with p53 mutations in esophageal carcinogenesis.

Adult↗

Variability in immunohistochemistries of IgM M-proteins binding to sulfated glucuronyl paragloboside.

Serum IgMs from 4 of 12 patients with polyneuropathy and IgM M-proteins that bind to sulfated glucuronyl paragloboside (SGPG) strongly immunostained the human peripheral nerve myelin (group A), whereas those from the other eight patients strongly immunostained the cytoplasm of the Schwann cells surrounding the myelin sheath with only weak staining of the myelin (group B). Strong immunostaining of peripheral myelin by IgMs from group A patients may be due to the strong cross-reactivities against P0 and peripheral myelin protein-22 (PMP-22), which are localized in compact myelin. Only three patients (all in group B) showed some response to the immunotherapies. Weak reactivities to P0 and and PMP-22 might indicate the possibility of improvement after the immunotherapies.

Aged↗

Guillain-Barré syndrome associated with IgG monospecific to ganglioside GD1b.

The authors examined serum antiglycolipid antibodies in 445 patients with Guillain-Barré syndrome (GBS). Among them, nine had anti-GD1b IgG antibodies with no reactivity to other glycolipids tested. All those patients had sensory disturbance, and none had the primary axonal form. Anti-GD1b IgG antibodies may bind to primary sensory neurons and paranodal myelin, where GD1b is localized, and be involved in the pathogenesis of sensory disturbance and demyelination. However, more study is needed to substantiate the roles of anti-GD1b IgG antibodies.

Adult↗

Id1 expression is associated with histological grade and invasive behavior in endometrial carcinoma.

Basic helix-loop-helix (bHLH) DNA-binding proteins have been reported to regulate tissue-specific transcription of cellular differentiation within multiple cell lineages. The Id family of helix-loop-helix proteins does not possess a basic DNA-binding domain and functions as a negative regulator of bHLH proteins by forming high-affinity heterodimers with bHLH proteins. Id proteins were originally characterized as inhibitors of DNA binding and cell differentiation. Thus, overexpression of Id proteins correlates with cell proliferation and arrested differentiation in many cell lineages. To elucidate the involvement of Id1 in endometrial carcinogenesis, we analyzed serial frozen sections for Id1 protein expression in 20 cases of endometrial carcinoma and 20 cases of normal endometria by fluorescent immunohistochemistry. We analyzed the relationship between the percentages of Id1-stained cells and the patient's characteristics, including histological grade, clinical stage, presence of invasion to >1/2 myometrium, and clinical outcome. In normal endometria, Id1 was not detected in either the proliferative or the secretory phase. There was, however, abundant Id1 immunoreactivity in the endometrial carcinoma cells. Moreover, Id1 was strongly expressed in the inflammatory cells. Scoring on the basis of the percentage of positive cells indicated that Id1 expression is significantly associated with histological grade (P<0.05) and the presence of invasion to >1/2 myometrium (P<0.05). Our results demonstrate that increased Id1 expression in endometrial carcinoma correlates with the malignant potential of this tumor.

Adult↗