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Biomedical subjects

T Shiba

Publications and source records attributed to T Shiba.

351 records · Page 20Linked to original sources

Lipoma of the falciform ligament: US, CT, and MRI appearances.

A case of lipoma of the falciform ligament was demonstrated using computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI). US demonstrated a heterogeneous solid mass anteriorly in the upper portion of the abdomen. CT and MRI revealed a solitary, fatty mass with a small amount of soft tissue in it.

Abdominal Neoplasms↗

Serum gliclazide concentration in diabetic patients. Relationship between gliclazide dose and serum concentration.

Serum levels of gliclazide were determined by radioimmunoassay in seven healthy controls and in 18 diabetic in-patients receiving single oral dosing and consecutive dosing over 5 days. Following a single oral dose of 40 mg in the seven controls and eight diabetic patients, and 120 mg in ten diabetic patients, the serum levels of gliclazide peaked on average at 2 h, followed by a slow decline, the t1/2 being 16.5 h in the volunteers, 12.3 h in the diabetic patients receiving 40 mg, and 10.5 h in those receiving 120 mg. During consecutive administration, the serum levels both at fasting and at the peak reached a plateau in 2 days and no further accumulations were observed. The steady-state peak levels of gliclazide in the diabetic patients revealed a strongly positive correlation with the dose per m2 body surface area (r = 0.78, P less than 0.001), and their steady-state fasting levels correlated positively but weakly with the dose per m2 body surface area (r = 0.48, P less than 0.05). Thus, measuring either the fasting or the peak concentration of gliclazide will be useful for monitoring drug concentration in the serum. Pharmacokinetics of gliclazide will contribute to the elucidation of the relationship of serum level and clinical effectiveness in diabetic subjects.

Administration, Oral↗

The nucleotide sequences of copia and copia-related RNA in Drosophila virus-like particles.

We have shown previously that Drosophila cells contain virus-like particles (VLPs) containing 5-kilobase (kb) RNA that hybridizes to a transposable element, termed copia. We have suggested that VLPs and copia are derivatives of viral particles and proviral forms, respectively, of 'copia' retrovirus, a putative Drosophila retrovirus. To further clarify the relationship between copia and copia-related RNA in VLPs (VLP H-RNA), we determined and compared their nucleotide sequences. VLP H-RNA was found to be an unspliced, genome-sized transcript of copia, and, like retroviral genome RNA, VLP H-RNA is terminally redundant with termini localized in the long terminal repeats (LTRs) of copia. VLP H-RNA contains two long open reading frames (ORFs), one of which includes the coding sequence for a predominant VLP protein of relative molecular mass (Mr) 31,000 (31K). Here we show that, in contrast to 17.6 ORF2, ORFs of copia have no extensive amino-acid sequence homology to the RT region of the reverse transcriptase of retrovirus in vertebrates. Because of a one-base insertion/deletion, the two ORFs in VLP H-RNA are fused and become a single, longer ORF in a genomic copia.

Amino Acid Sequence↗

Unusual priming mechanism of RNA-directed DNA synthesis in copia retrovirus-like particles of Drosophila.

Drosophila cells contain virus-like particles (VLPs) containing 5 kilobases (kb) of RNA (VLP H-RNA) homologous to the transposable element copia. The identity between VLP H-RNA and copia DNA has previously been confirmed at the nucleotide sequence level and reverse transcriptase activity is also detected in the VLPs. These results suggest that VLPs and copia are derivatives of viral particle and provirus forms, respectively, of the copia retrovirus-like particle. If the copia retrovirus-like particle replicates by a mechanism similar to the mechanism of vertebrate retroviral replication, a cellular transfer RNA would prime synthesis of the first DNA strand. We show that this is indeed so but that copia retrovirus-like particle has a novel type of priming mechanism; the first DNA extension does not start from the 3' end of a tRNA, but from an internal site (two nucleotides after the anticodon loop) of the Drosophila initiator methionine tRNA (tRNAMeti).

Animals↗

Three TNFalpha single nucleotide polymorphisms in the Japanese population.

BACKGROUND: Tumour necrosis factor-alpha (TNFalpha) is an essential regulator of immune responses and is implicated to relate to several types of disease susceptibilities. Population information on polymorphisms is essential for the study of genetic diseases. AIM: To obtain accurate information about single nucleotide polymorphisms (SNPs) in the TNFalpha gene in the Japanese population. SUBJECTS AND METHODS: The entire TNFalpha gene was screened for SNPs by directly sequencing 48 chromosomes derived from 24 unrelated Japanese individuals. Allele frequencies of each polymorphism were determined and compared with those previously reported in other populations. RESULTS: Three SNPs, -308G/A at nt -308, IVS1 + 125G/A at nt 492 and IVS3 + 104G/A at nt 1359 were observed, of which one (IVS3 + 104G/A at nt 1359) was novel. In addition, allele frequencies of -308G/A were remarkably different from those presented in the NCBI dbSNP, indicating a significant ethnic difference. CONCLUSIONS: The polymorphisms and allele frequencies obtained in this study will be useful for genetic studies of common diseases such as osteoporosis and rheumatoid arthritis in the Japanese population.

Alleles↗

Lipopolysaccharides: structural principles and biologic activities.

Structural principles of the three regions of the lipopolysaccharide molecule are briefly discussed. One of the recently available, chemically synthesized lipid A analogues has been tested for biologic activities. The preparation was found to be toxic, pyrogenic, and mitogenic. The amounts, however, needed for expression of effects similar to those of lipid A were about 500 times higher. These investigations are aimed at verifying the proposed structure of lipid A and at evaluating structure-activity relationships.

Animals↗

Recent developments in the organic synthesis of lipid A in relation to biologic activities.

For elucidation of a relationship between chemical structure and biologic activity of lipid A, syntheses of 13 derivatives of glucosamine beta (1-6) disaccharide, which were acylated at 3, 4, and 6'-hydroxyl groups and/or phosphorylated at positions 1 and 4', were carried out. The results showed the importance of the presence of the phosphate group at either position 1 or 4' and of the beta-hydroxyl group in acyl function, particularly in N-linked fatty acids, for the exhibition of biologic activities characteristic of lipid A. New evidence on the positions of fatty acids in natural lipid A of Escherichia coli species obtained by means of 2D-H nuclear magnetic resonance was also demonstrated; the findings indicate that the 3'-hydroxyl group is acylated and the 6'-hydroxyl group in the molecule must be free.

Lipid A↗

Congenital coronary artery fistulae arising from bilateral coronary arteries and emptying into both pulmonary artery and left ventricle: a rare presentation.

Congenital coronary artery fistulae rarely empty into both the pulmonary artery and the left ventricle. To our knowledge, there have been only two such cases reported in the literature. This paper presents a third case. The pattern of drainage into the left ventricle in the present case was, however, quite different from that observed in the previous reports.

Adult↗

In vitro analysis of AcrySof intraocular lens glistening.

PURPOSE: The authors studied the effects of changes in packaging solution temperature on the development of glistening in acrylic intraocular lenses (AcrySof, Alcon). METHODS: Glistening was examined by slit lamp at each condition. In Experiment 1, AcrySof lenses were soaked in physiologic saline adjusted to 15 degrees C and 37 degrees C in an incubator. In Experiment 2, AcrySof lenses were soaked in physiologic saline adjusted to 37 degrees C and 60 degrees C for 5 min, then stored in physiologic saline adjusted to 15 degrees C. In Experiment 3, glistening formation was induced in AcrySof lenses by soaking them in warm water (37 degrees C). The lenses were allowed to dry at 15 degrees C and then soaked in physiologic saline adjusted to 15 degrees C. After storage of dry AcrySof lenses at 37 degrees C in an incubator for 10 months followed by soaking in physiologic saline adjusted to 15 degrees C, glistening formation was evaluated in Experiment 4. RESULTS: Glistening became observable after 1 month, despite the temperature having been lowered to 15 degrees C. No glistening was observed in the lenses soaked in physiologic saline adjusted to 37 degrees C after 5 min, but glistening was observed 1 month after soaking. When allowed to dry at 15 degrees C, the glistening decreased. After 1 month of soaking at 15 degrees C, glistening was again observable. CONCLUSIONS: AcrySof lenses soaked in warm water for a short time may change characteristics, and therefore, close monitoring of the temperature and time of soaking is necessary to prevent glistening formation.

Acrylic Resins↗