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Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 217 records · Page 12Linked to original sources
PubMed2000

Genetic polymorphism of 5,10-methylenetetrahydrofolate increases risk of myocardial infarction and is correlated to elevated levels of homocysteine in the Japanese general population.

BACKGROUND: Hyperhomocysteinemia, an independent and graded risk factor for coronary artery disease, can result from both environmental and hereditary factors. C677T mutation of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene [alanine/valine (A/V) polymorphism], one of the key enzymes involved in catalyzing the remethylation of homocysteine, has recently been reported. OBJECTIVE: To evaluate the incidence of the MTHFR genotypes and their significance in determining the risk for myocardial infarction of Japanese men. METHOD: The subjects consisted of 199 healthy men (mean age, 60 years) and 230 male patients with myocardial infarction (mean age, 59 years). The coronary-artery lesions were evaluated by coronary angiography. The MTHFR genotype was analyzed by polymerase chain reaction and then by digestion with Hinfl. Total plasma levels of homocysteine for each MTHFR genotype were compared with those in healthy controls. RESULTS: The prevalences of the A and V alleles among the healthy male subjects were 0.652 and 0.348 in the Hardy-Weinberg equilibrium. The total levels of homocysteine in the plasma of the healthy male subjects were 8.6 +/- 3.3, 8.9 +/- 4.1, and 11.6 +/- 5.6 mumol/l, for AA, AV, and VV genotypes, respectively. Individuals with the VV homozygous mutant genotype thus had the highest plasma levels of homocysteine. Logistic analysis revealed that the levels of high-density lipoprotein cholesterol, hypertension, diabetes mellitus, MTHFR VV genotype, and triglycerides were all independent risk factors for myocardial infarction. The VV genotype was more prevalent among patients with myocardial infarction (mean age, 59 years) than it was among the control subjects (17.0 versus 10.6%, P < 0.05). However, there were no differences in the numbers of stenotic coronary arteries among the MTHFR genotypes. CONCLUSION: The VV genotype of MTHFR increases plasma levels of homocysteine in healthy controls, and this mutation indicates a genetic predisposition toward a greater than normal risk of myocardial infarction for Japanese men.

Cohort Studies↗
PubMed2000

[Chest radiograph of atypical pneumonia: comparison among Chlamydia pneumoniae. Pneumonia, ornithosis, and Mycoplasma pneumoniae pneumonia].

No report has been found comparing Chlamydia pneumoniae (C. pneumoniae) pneumonia radiographically with other atypical pneumonias, Chlamydia psittaci (C. psittaci) pneumonia and Mycoplasma pneumoniae (M. pneumoniae) pneumonia. We described the chest radiographs of three kinds of pneumonia cases: 46 cases of C. pneumoniae pneumonia, 39 cases of C. psittaci pneumonia, and 131 cases of M. pneumoniae pneumonia. Radiographic shadows were categorized into main shadows and sub-shadows. The main shadows are classified from the viewpoint of the characteristics; air space consolidation(AS), ground-glass opacity(GG), reticular shadow(RS), bronchopneumonia(BP), and small nodular shadows (SN). The size, the site, and the number of the main shadows were also analyzed. In comparison among the three pneumonias, BP was the most frequent in M. pneumoniae pneumonia (0.40/case). AS predominated in C. pneumoniae pneumonia (0.67/case), and GG in C. psittaci pneumonia (0.62/case). The number of main shadows was equal, about 1.4/case in three pneumonias. Large shadows were less frequent in M. pneumoniae pneumonia than C. pneumoniae pneumonia (p = 0.02) and C. psittaci pneumonia (p = 0.01). Main shadows were more frequent in the outer zone in M. pneumoniae pneumonia than C. psittaci pneumonia (p = 0.01), and in the middle zone in C. psittaci pneumonia than in M. pneumoniae pneumonia (p = 0.02). Cases with bilateral main shadows were less common in M. pneumoniae pneumonia (9%) than C. pneumoniae pneumonia(33%, p = 0.001) and C. psittaci pneumonia(30%, p = 0.005). Thickening of bronchovascular bundles as a sub-shadow was most frequently noted in M. pneumoniae pneumonia. Some differences among the three atypical pneumonias were seen in the chest radiograph. However, no specific findings of C. pneumoniae pneumonia were shown radiographically in this study.

Aged↗
PubMed2000

Contralateral subtraction: a novel technique for detection of asymmetric abnormalities on digital chest radiographs.

A novel contralateral subtraction technique has been developed to assist radiologists in the detection of asymmetric abnormalities on a single chest radiograph. With this method, the lateral inclination is first corrected by rotating and shifting the original chest image so that the midline of the thorax is aligned with the vertical centerline of the original chest image. The rotated image is then flipped laterally to produce a reversed "mirror" image. Finally, the mirror image is warped and subtracted from the original image for derivation of the contralateral subtraction image. The three key techniques which are employed in this study are applied successively to the initial contralateral subtraction technique for acquisition of improved subtraction images. One hundred PA chest radiographs, including 50 normals and 50 abnormals, were used as the database for this study. The percentage of chest images, which were rated as being adequate, good, or excellent quality of subtraction images by employing a subjective evaluation method, was improved from 73% to 91% by use of the three key techniques. The contralateral subtraction technique can be used for detection of any asymmetric abnormalities, such as lung nodules, pneumothorax, pneumonia, and emphysema, on a single chest radiograph, and therefore has potential utility in a high proportion of abnormal cases.

Biophysical Phenomena↗
PubMed2000

Computerized analysis of the likelihood of malignancy in solitary pulmonary nodules with use of artificial neural networks.

PURPOSE: To develop a computer-aided diagnostic scheme by using an artificial neural network (ANN) to assist radiologists in the distinction of benign and malignant pulmonary nodules. MATERIALS AND METHODS: Fifty-six chest radiographs of 34 primary lung cancers and 22 benign nodules were digitized with a 0.175-mm pixel size and a 10-bit gray scale. Eight subjective image features were evaluated and recorded by radiologists in each case. A computerized method was developed to extract objective features that could be correlated with the subjective features. An ANN was used to distinguish benign from malignant nodules on the basis of subjective or objective features. The performance of the ANN was compared with that of the radiologists by means of receiver operating characteristic (ROC) analysis. RESULTS: Performance of the ANN was considerably greater with objective features (area under the ROC curve, Az = 0.854) than with subjective features (Az = 0.761). Performance of the ANN was also greater than that of the radiologists (Az = 0.752). CONCLUSION: The computerized scheme has the potential to improve the diagnostic accuracy of radiologists in the distinction of benign and malignant solitary pulmonary nodules.

Adult↗
PubMed2000

Platelets expressing P-selectin and platelet-derived microparticles in stored platelet concentrates bind to PSGL-1 on filtrated leukocytes.

The levels of interleukin-6 and platelet-derived microparticles (PMPs) were measured in the blood of 137 patients with side effects from platelet concentrate (PC) transfusion with leukocyte removal filtration, P-selectin-expressing platelet and PMPs in stored PC before and after the filtration, and filtered leukocytes positive for P-selectin glycoprotein ligand-1. The side effects, which were observed in 203 transfusions for 84 patients with hematologic disease and 53 patients with nonhematologic disease with no significant difference between the two groups, included urticaria (75.9%), erythema (18.7%), and fever (17.2%), but no anaphylactic reactions. The levels of interleukin-6 and PMP correlated in both groups, and were significantly higher in the hematologic disease group than in the nonhematologic disease group. The level of PMP, but not interleukin-6, was significantly higher for patients testing positive for allergic reaction than for those testing negative. In the stored PC prior to filtration, the level of interleukin-6 was normal. The level of P-selectin-expressing platelets and PMPs was elevated before filtration, but was significantly lower after filtration. Taken together, the results suggest that PMP is involved in the generation of transfusion reactions, and indicate that both platelets and PMP displaying P-selectin bind to P-selectin glycoprotein ligand-1 of leukocytes retained by the leukocyte filter.

Blood Platelets↗
PubMed2000

Binding of recombinant human cytokeratin 19 to laminin: a possible role in interaction between intermediate filament derived from epithelial cells and extracellular matrixes.

Cytokeratin 8 (CK8) and cytokeratin 19 (CK19) is a specific cytoskeletal component of simple epithelia, including bronchial epithelial cells. We hypothesized that CK8 or CK19 released from epithelial cells may bind to and cause damage to extracellular matrixes through binding of anti-CK8 or anti-CK19 autoantibodies. In the present study, bindings of recombinant human CK8 and CK19 to laminin (both derived from mouse sarcoma cells and human), collagen, gelatin, and fibronectin were evaluated by a modified enzyme-linked immunosorbent assay (ELISA). In addition, binding of CK19 to laminin was also confirmed by inhibition assay. As a result, CK19 strongly bound to mouse laminin as well as human laminin. Pretreatment with laminin significantly reduced the binding of CK19 to laminin. However, binding of recombinant CK19 to laminin was not demonstrated by Western immunoblot, suggesting that SDS treatment of laminin diminished the binding. These results suggest that released CK19 from epithelial cells may have played a role in the damage of basement membrane by accumulation of an immune complex composed by CK19 and anti-CK19 autoantibody.

Animals↗
PubMed2000

Effect of epinephrine on GLUT2 protein content in mouse liver.

The intraperitoneal administration of epinephrine (EP) to mice caused a significant increase in the blood glucose level and a significant decrease in the liver glycogen content 1 h after its administration at 0.6 mg/kg (blood glucose; p < 0.01, liver glycogen; p < 0.01). The liver type glucose transporter (GLUT2) mRNA expression and protein content from mouse liver significantly increased in the intraperitoneally EP-treated mice when compared to that in normal mice (mRNA; p < 0.01, protein; p < 0.01). These results suggest that the hyperglycemic effect of EP is due, at least in part, to the increase of GLUT2 protein synthesis.

Animals↗
PubMed2000

Structural studies of C-amidated amino acids and peptides: crystal structures of Z-Gly-Phe-NH2, Tyr-Lys-NH2, and Asp-Phe-NH2.

As part of the series investigating the structural features of C-terminal amidated amino acids and peptides, three crystal structures of Z-Gly-Phe-NH2, Tyr-Lys-NH2, and Asp-Phe-NH2 were analyzed by the X-ray diffraction method, and their molecular conformations and intermolecular interactions were investigated. Although the respective dipeptides exhibited an energetically allowable torsion angle concerning each backbone or side chain, the observed extended (Z-Gly-Phe-NH2, Asp-Phe-NH2) and folded (Tyr-Lys-NH2) conformations were considerably different from those of the corresponding unamidated peptides, due to the conformational flexibility of the respective dipeptides. The comparison between the crystal packings of the amidated and unamidated dipeptides indicated that the C-terminal amides tend to associate with the same neighboring group through hydrogen bonds, in which both the amide NH and O=C groups participate, while the unamidated peptides prefer a linear molecular connection, where both or either of the two carboxyl oxygens participate in the hydrogen bond formation. The difference in hydrogen bonding ability between the C-terminal amide and carboxyl groups has been considered to be based on the structural data of the related peptides analyzed so far.

Amides↗
PubMed2000

Molecular dynamics simulations of bovine cathepsin B and its complex with CA074.

To promote our better understanding of the dynamic stability of the bovine cathepsin B structure, which is characterized by an extra disulfide bond at Cys148-Cys252 from the other species, and of the binding stability of CA074 (a cathepsin B-specific inhibitor), molecular dynamics (MD) simulations were performed for the enzyme and its CA074 complex, assuming a system in aqueous solution at 300 K. The MD simulation covering 400 ps indicated that the existence of a Cys148-Cys252 disulfide bond increases the conformational flexibility of the occluding loop, although the conformational stability of the overall structure is little affected. The structural characteristics of the complex elucidated by X-ray analysis were suggested to be also intrinsic and stable in the dynamic state; the hydrogen bonding/electrostatic interactions between the main and side chains of CA074 and the Sn and Sn' subsites of the enzyme were maintained throughout the MD simulation. Furthermore, the simulation made clear that the binding of CA074 significantly restricted the conformational flexibility of the substrate binding region, especially the occluding loop, of cathepsin B. Statistical analyses during the simulation suggest that the selectivity of CA074 for cathepsin B stems from the tight P1'-S1' and P2'-S2' interactions, assisted in particular by double hydrogen bonds between the carboxyl two oxygens of the CA074 C-terminus and the imidazole NH groups of His110 and His111 residues.

Animals↗
PubMed2000

Recent epidemiological status of feline upper respiratory infections in Japan.

Epidemiology of upper respiratory infections of cats was studied. Nasal, ocular, and oral swabs collected from 111 cats presented at animal hospitals during the past 2.5 years were examined. Twenty-four (21.6%) and 4 (3.6%) cats were diagnosed as feline calicivirus (FCV) infection and feline viral rhinotracheitis, respectively, indicating FCV is more prevalent than feline herpesvirus-1, which revealed a considerable shift from data obtained in 1970s. Cat sera immunized by using vaccines containing either FCV F9 or 255 strains neutralized 42.9% and 66.7% of the FCV isolates, respectively. Chlamydia psittaci, examined by a PCR assay amplifying the ompA gene, was found in 26.9% of 26 diseased cats that typically showed conjunctivitis and rhinitis.

Animals↗
PubMed2000

Histological changes of the pancreas in an elderly diabetic patient positive for GAD antibody.

We examined the histological changes of the pancreas in a 75-year-old diabetic woman who was treated with sulphonylurea for 10 years and required insulin treatment for the subsequant 10 years. She was positive for antiglutamic acid decarboxylase antibody (GAD Ab) 20 years after the diagnosis of diabetes. Her autopsied pancreas revealed disfigured islets and no beta cells. These changes were indistinguishable from those of the long-sustained type 1 diabetes mellitus, and insulitis was not found. This case suggests that diabetic patients positive for the GAD Ab, even if oral hypoglycemic agents are effective, may develop complete beta cell destruction over a long period.

Aged↗
PubMed2000

Familial cases of severe measles pneumonia.

We report two cases of severe measles pneumonia. Patient 1, a 17-year-old boy who contracted measles in the acute phase of infectious mononucleosis caused by Epstein-Barr virus (EBV), transmitted the disease to patient 2, his father. Both patients presented severe pneumonia with bilateral diffuse micronodular shadows. Diagnoses were established in both patients by antibody titers for measles and reverse transcriptase-polymerase chain reaction (RT-PCR) of blood and throat swab. Multinucleated giant cells with intranuclear inclusion bodies were revealed in the transbronchial lung biopsy (TBLB) specimen of patient 2. Both patients recovered with pulse steroid therapy.

Adolescent↗
PubMed2000

Langerhans cell histiocytosis limited to the pituitary-hypothalamic axis--two case reports.

Langerhans cell histiocytosis rarely presents as a solitary lesion in the pituitary-hypothalamic region, and is indistinguishable from germinoma, which occurs much more frequently, especially in Japanese. A 14-year-old girl and a 9-year-old girl presented with polydipsia and polyuria as the initial symptoms. Magnetic resonance (MR) imaging demonstrated a round mass at the pituitary stalk appearing as isointense on T1-weighted imaging and hyperintense on T2-weighted imaging. Endocrinological examination revealed mild hypopituitarism with central diabetes insipidus. Both patients underwent open craniotomy. Histological examination revealed granulomatous tissue with eosinophil infiltration and frequent Langerhans histiocyte clustering, compatible with the diagnosis of Langerhans cell histiocytosis. Low-dose local irradiation of 20 Gy was administered. First patient was followed up for 8 years, and her hypopituitarism gradually improved to a minimal level with only amenorrhea as the residual symptom. Recent MR imaging showed no residual mass at the region. Second patient was followed up for 15 months, and her diabetes insipidus is stable. MR imaging performed 5 months after the treatment showed marked reduction of the mass. These cases reemphasize the importance of histological diagnosis for lesions with similar neuroimaging appearances. Biopsy and low-dose irradiation are an effective treatment for this rare and essentially benign lesion, as opposed to attempting total removal of the mass.

Adolescent↗
PubMed2000

Retention of relative force in the scaling of a serial force pattern.

The present study was designed to examine the retention of relative force in the scaling of a serial force pattern in finger-tapping sequences. On practice trials, 11 male college students tapped a force plate connected to strain gauges which provided feedback. On test trials, subjects recalled both the force pattern (100 g-100 g-100 g-300 g) and intertap interval (400 msec.) acquired during practice without feedback (recalled task) and then produced a halved (halved task) or doubled-force (doubled task) at the fixed intertap interval. Analysis showed that, although there was no difference for absolute forces between the recalled task and the halved task, the forces at the doubled task were three times as great as those at the recalled task. For relative forces, on the other hand, although there was no difference among the three tasks, the force ratios were closer to 1:1:1:2 than 1:1:1:3. This indicated that the scaling of force pattern was a more difficult adaptive task than that of the intertap interval in the previous study (Inui, Ishida, & Yamanishi, 1999).

Adult↗
PubMed2000

[Oral allergy syndrome in patients with Japanese cedar pollinosis].

Patients with pollinosis sometimes complain of oral symptoms (itching and tingling with or without edema of the lips, mouth and tongue) after eating fresh fruits and vegetables. This condition has been termed Oral Allergy Syndrome (OAS). Twenty-three patients with Japanese cedar pollinosis and OAS for fresh fruits and vegetables were included in this study. Their mean age was 31.3 years (range = 5 to 62). The fruits that caused OAS in these patients included melon, apple, peach, and kiwi fruit. Most patients with OAS exhibited hypersensitivity to more than two foods. Specific IgE antibodies to inhaled allergens of mite, Japanese cedar pollen, birch pollen, melon, apple, peach, and kiwi were evaluated using the Pharmacia CAP system. Eleven of the 16 subjects with specific IgE antibodies for birch pollen, did not suffer symptoms during the birch and alder pollen season. In subjects with specific IgE antibodies for fruits, 13 out of 20 patients showed specific IgE antibodies for apple, and 8 out of 9 patients with OAS for apples were also positive for specific IgE antibodies for apples. On the other hand, 17 patients had no specific IgE antibodies for melon, and only two patients and one patient showed specific IgE antibodies for kiwi fruit and peach, respectively. These results suggest that the evaluation of specific IgE antibodies to birch pollen and apple may be useful for diagnosing OAS in patients with Japanese cedar pollinosis.

Adult↗
PubMed2000

[Insulin resistance and liver].

The liver plays an important role in glucose homeostasis. In the postabsorptive state, plasma glucose is regulated by both hepatic glucose output(HGO) and peripheral glucose utilization(PGU). Insulin and glucagon regulate both HGO and PGU. Increased HGO and decreased PGU, suggesting insulin resistances bring increased fasting blood glucose. While glucose homeostasis after glucose ingestion is regulated by several factors. The regulation of hepatic glucose uptake(HGU) occurs by way of the hormonal milieu(insulin and glucagon), the glucose level, and the rote of glucose delivery. The presence of coordinated changes in insulin, glucagon and the glucose level in combination with the portal signal ensures adequate HGU in response to liver. Hepatic insulin resistance(increased HGO and decreased HGU) and peripheral insulin resistance(decreased PGU) are the characters of glucose intolerance.

Animals↗