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Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 829 records · Page 46Linked to original sources
PubMed1991

Expression of a synthetic gene for human cap binding protein (human IF-4E) in Escherichia coli and fluorescence studies on interaction with mRNA cap structure analogues.

An artificial gene coding for the human cap binding protein (hCBP: human IF-4E) was chemically synthesized and expressed in Escherichia coli under the control of a trp promoter. The DNA duplex of 662 bp was designed and constructed from 44 oligodeoxynucleotide fragments of typically 30 nucleotides in length. Although the hCBP gene was not directly expressed in E. coli HB101, we succeeded in its high-level expression as a fusion protein connected with a portion of human growth hormone through a tetradecapeptide (Asp-Asp-Pro-Pro-Thr-Val-Glu-Leu-Gln-Gly-Leu-Val-Pro-Arg) that contains the recognition sequence for a site-specific protease alpha-thrombin. Upon induction with 3-indoleacrylic acid, the fusion protein accumulated with a yield of about 20% of the total proteins of the host cell. Upon the treatment of the fusion protein with alpha-thrombin, which recognizes the sequence "Val-Pro-Arg," specific proteolysis at the fused junction occurred efficiently. In this system, nonspecific digestion by alpha-thrombin was not marked. About 15 mg of recombinant hCBP was obtained from a 1-liter culture. Association constants between the recombinant hCBP and mRNA cap structure analogues were determined by fluorescence spectroscopy. The values obtained for the m7GpppA, m7GTP, and m7GMP were almost the same as those reported for the IF-4E isolated from human erythrocyte cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

Cavernous lymphangioma of the breast: case report with electron microscopic and immunohistochemical investigations.

A rare case of cavernous lymphangioma of the breast in a 16-year-old Japanese girl was investigated by light and electron microscopies, and immunohistochemistry. The patient, who had a soft breast tumor measuring 16 x 14 cm, had undergone a tumorectomy two years after she noticed the tumor. Histologically, the tumor was composed of numerous narrow spaces containing amorphous fluid lined with a monolayer of endothelial cells. Abundant collagen fibers and numerous fibroblasts were found beneath the endothelium. Histological findings confirmed a diagnosis of lymphangioma of the breast. Immunohistochemically, the endothelium showed negative immunoreaction for factor VIII-related antigen, but the discontinuous basal lamina was positive for laminin. Ultrastructurally, numerous microfilaments and pinocytotic vesicles were found in the cytoplasm of the endothelial cells, and intermediate junctions were recognized between adjacent cells. In addition, a discontinuous basal lamina was seen beneath the endothelium. Electron microscopic and immunohistochemical investigations are thus useful in confirming a diagnosis of cavernous lymphangioma of the breast.

Adolescent↗
PubMed1991

Heteroplasmy and polymorphism in the major noncoding region of mitochondrial DNA in Japanese monkeys: association with tandemly repeated sequences.

We have sequenced the major noncoding region of mitochondrial DNA (mtDNA) of four Japanese monkeys and have found length polymorphism in the sequenced region. The length polymorphism resulted from two tandem duplications of 160-bp sequences which contained the conserved sequence blocks 2 and 3 and the light-strand transcription-promoter region. We also found polymorphisms in this mtDNA region among 100 Japanese monkeys from 12 localities, 90 of which were analyzed using DNA amplified through the polymerase chain reaction. In two localities, we found individuals with heteroplasmic mtDNA which had different numbers of the 160-bp repeats mentioned above. The 100 samples were classified into six types in terms of length and presence/absence of the recognition site of two restriction enzymes in the major noncoding region.

Animals↗
PubMed1991

Adaptability of restrained molecular dynamics for tertiary structure prediction: application to Crotalus atrox venom phospholipase A2.

In order to assess the adaptability and/or applicability of the restrained molecular dynamics (RMD) simulation for building a possible tertiary structure of a protein from the X-ray crystal structure of a family reference protein, the tertiary structure prediction of Crotalus atrox venom phospholipase A2 (PLA2) was attempted based on the X-ray crystal structure of bovine pancreatic PLA2. For the formation of secondary and tertiary structures from the fully extended starting structure, the RMD simulation with interatomic distance restraints and torsion angle restraints, which were derived from homologous amino acid sequence regions in the reference protein, was carried out until the molecular system was fully equilibrated. The predicted tertiary structure of C. atrox venom PLA2 was compared with its X-ray crystal structure, and furthermore the utility of this method was discussed by reference to the similar tertiary structure prediction of beta-trypsin from the X-ray crystal structure of an elastase.

Amino Acid Sequence↗
PubMed1991

Significance of intracellular free calcium and magnesium and calcium-regulating hormones with sodium chloride loading in patients with essential hypertension.

This study was designed: (1) to test the hypothesis that the pressor response to sodium chloride loading in patients with essential hypertension is associated with disorder of divalent cations (calcium and magnesium); and (2) to clarify the relationship between intracellular free calcium concentration and serum levels of calcium-regulating factors and intracellular magnesium concentration. With sodium chloride loading, mean blood pressure, urinary calcium and magnesium excretions and platelet calcium concentration were increased, and serum total and ionized calcium, magnesium concentrations and erythrocyte magnesium concentration were decreased. Change in mean blood pressure was correlated with changes in parathyroid hormone (r = 0.49, P less than 0.05), serum total and ionized calcium (r = -0.50, P less than 0.05) and erythrocyte magnesium (r = -0.56, P less than 0.05) and platelet calcium concentrations (r = 0.46, P less than 0.05). In addition, change in platelet calcium concentration was related to changes in parathyroid hormone (r = 0.44, P = 0.05), serum total and ionized calcium (r = -0.66, P less than 0.01) and erythrocyte magnesium concentration (r = -0.49, P less than 0.05). It is concluded that the pressor effect of excessive sodium chloride intake on blood pressure in patients with essential hypertension is associated with a disorder of divalent cations and that alteration of the intracellular free calcium concentration with sodium chloride loading may occur through handling of serum total and ionized calcium, parathyroid hormone and/or intracellular magnesium concentration.

Adult↗
PubMed1991

Role of intracellular cation abnormalities in development of left ventricular hypertrophy.

To elucidate factors determining the development of left ventricular hypertrophy, we performed measurements of intraerythrocyte sodium and intraplatelet calcium concentrations, measurements of plasma and urinary catecholamine levels and plasma renin activity, calculation of left ventricular mass using echocardiography, and 24-h ambulatory blood pressure (BP) monitoring. The results indicate that abnormalities of sodium and calcium mobilization may play an important role in the adaptation of left ventricular muscle to a persistent increase in BP.

Adult↗
PubMed1991

Control of specific absorption rate distribution using capacitive electrodes and inductive aperture-type applicators: implications for radiofrequency hyperthermia.

A method of controlling the specific absorption rate (SAR) distribution in radiofrequency hyperthermia is proposed. The superposition of the current density associated with capacitively coupled electrodes and that associated with H-field coupled inductive aperture-type applicators modifies the actual current distribution in the heating material. Using a two-dimensional finite element method, we have shown that "focusing" is possible such that the SAR at the center of a phantom can be adjusted to be approximately twice that in superficial regions, even though the wavelength is considerably greater than the dimensions of the phantom.

Electric Conductivity↗
PubMed1991

The effect of mass screening for breast cancer: results of a multivariate analysis.

To evaluate the life-prolonging effect of mass screening for breast cancer, we compared the risk of death for the patients detected by mass screening with that for the patients diagnosed in out-patient clinics, after adjusting for other relevant factors simultaneously by using the Cox regression model. A multivariate analysis using the Cox regression model in which clinical staging of disease was taken as one of the independent variables, showed that the risk of death for patients detected by mass screening was smaller by 0.765 times than that for patients found in out-patient clinics although the reduction was not statistically significant. This small reduction might be partly due to the effect of mass screening through early detection even within the same stage, and partly due to length bias, lead time bias and self-selection bias. When clinical staging of disease was removed from the independent variables, the risk of death for patients detected by mass screening was reduced from 0.765 times to 0.677 times that for patients diagnosed in out-patient clinics, which was statistically significant (P greater than 0.01). For asymptomatic patients detected by mass screening, such as reduction of the risk of death was from 0.789 times to 0.555 times that for patients found in out-patient clinics (P less than 0.05). These results suggest that mass screening for breast cancer may contribute to the reduction of the risk of death, although the effect of biases inherent in periodic screening was not removed completely in the present analysis.

Breast Neoplasms↗
PubMed1991

Chromosomal localization of the major histocompatibility complex (MHC) in the rhesus monkey and chimpanzee by fluorescence in situ hybridization.

Genes for the major histocompatibility complex (MHC) were localized by fluorescence in situ hybridization to the long arm of rhesus monkey chromosome 5. This localization contradicts previous reports, based on genetic investigation of somatic cell hybrids, that placed the MHC on chromosome 2 of this species. In the chimpanzee, the MHC loci were localized to 5p21.3, corresponding precisely to their location on human chromosome 6p21.3.

Animals↗
PubMed1991

Subpleural silicotic nodule radiographically resembling to small bronchial carcinoma.

A 65-year-old woman had a solitary nodule radiologically appearing as a coin lesion with pleural indentation, suggesting primary lung cancer. Operative findings and histological examination revealed it to be a silicotic nodule. Despite the rarity of this condition, silicotic nodules should be considered among the causes of solitary or small numbers of peripheral pulmonary nodules in adults.

Aged↗
PubMed1991

Adenocarcinoma and squamous cell carcinoma in the same lobe of the lung. A case report.

Multiple primary lung cancers, either synchronous or metachronous, are unusual. We treated a 70-year-old man with double synchronous lung cancers in the right upper lobe, an adenocarcinoma and a squamous cell carcinoma. As multiple malignant lesions in an early stage may be curable, those patients in whom a lung cancer has already been detected, and who have an increased risk, such as long history of heavy smoking or of exposure to some carcinogens, an aggressive check-up should be performed and should be closely watched.

Adenocarcinoma↗
PubMed1991

Spectroscopic study on interaction of nucleic acid base with tryptophan-containing tripeptides: acetyl-Trp-X-Trp-NHCH3 (X = Gly, Asn, Asp, Gln and Glu).

As part of a series of peptides designed to have binding ability selective for each of the nucleic acid bases, five tripeptides consisting of N-acetyl-Trp-X-Trp-NHCH3 (X = Gly, Asn, Asp, Gln and Glu) were synthesized, and their abilities to form complexes with four different nucleotides were examined by the fluorescence and phase distribution methods. The association constants obtained indicated that, depending on the sort of X residue, the peptides showed a variation in their interaction with guanosine monophosphate (GMP), while no noticeable selectivity was observed for other nucleotides adenosine monophosphate (AMP), uridine monophosphate (UMP) and cytidine monophosphate (CMP). The binding mode of N-acetyl-Trp-Asp-Trp-NHCH3 for the guanine base was further investigated using the proton nuclear magnetic resonance (1H-NMR) method. The mode was suggested to involve intimate cooperation of (1) the hydrogen bond formation between the carboxyl group of the Asp side chain and the guanine C2-amino group, and (2) the stacking interaction of the base with two terminal Trp residues of the peptide. Such interaction was strengthened by the protonation of the guanine base. A tentative binding mode is proposed based on these results.

Molecular Structure↗
PubMed1991

Urate oxidase activity and copper content in the liver of macular mutant mouse, a model animal for human congenital copper deficiency, Menkes' kinky hair disease.

The macular mouse is an X-linked recessive inherited mutant and is considered to be a model for human congenital copper deficiency, Menkes' kinky hair disease. The activity of urate oxidase, which has been believed to be a copper enzyme, and copper content in the liver of the mutant mouse were determined. The oxidase activity was maintained at normal level even though there was very low level of copper present in the liver through days 7 to 14. Copper administration increased the copper content in the liver to the normal level, but did not affect the oxidase activity.

Animals↗
PubMed1991

[Dental anthropological study of Mongoloid in China].

The purpose of this study was to evaluate the craniofacial and occlusal characteristics of the inhabitants in China. The material consisted of cephalograms, pantomograms, dental casts and anthropological measurements taken from 517 inhabitants: 416 Han Chinese in Beijing, Shanghai, Guangzhou and Changchun and 101 Mongolians in Hohhot. The data were compared among the above five regions and also with the Japanese data. The findings were summarized as follows: I. Craniofacial characteristics; a) The Han Chinese and the Mongolians showed brachycephaly. b) The inhabitants in Guangzhou showed a tendency of bimaxillary protrusion with a smaller facial height, and the inhabitants in Changchun showed a larger gonial angle with a larger facial height than those of the other regions. c) The Mongolians had a larger value of the saddle angle and of the bi-gonial breadth. d) Compared with the Japanese, their craniofacial complex was characterized by a larger facial angle, smaller mandibular plane angle and a smaller gonial angle. II. Occlusal characteristics; a) The inhabitants in China had a similar tendency in the dental arch form and in the dental trait frequency. b) The inhabitants in Beijing had a larger mesiodistal crown-diameter of the anterior teeth than those in the other regions. c) Compared with the Japanese, their teeth were characterized by a smaller mesiodistal crown-diameter (especially on the upper first molar), higher frequency of shovel-shape and lower frequency of Carabelli's tuberculum.

Adolescent↗