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Biomedical subjects

J Imamura

Publications and source records attributed to J Imamura.

35 records · Page 2Linked to original sources
PubMed1992

Quantification of gene expression over a wide range by the polymerase chain reaction.

We investigated the usefulness of the polymerase chain reaction (PCR) method for the relative quantification of gene expression using a simultaneously amplified sequence of beta-actin mRNA as an internal control for the target sequence of tax/rex mRNA of human T-cell leukemia virus type I. The PCR product of the internal control was reduced by delaying the addition of the primers for its sequence. The photostimulated luminescence of the bands was measured with a laser image analyzer, and the values were plotted against the cycle number. The cycle differences between the logarithmic phase of the curves for the target sequence and for beta-actin (delta cycle) showed a linear correlation with the initial concentration of the sample. This method is highly sensitive for evaluating gene expression over a wide range.

Actins↗
PubMed1991

Genetic alteration of p53 in some patients with adult T-cell leukemia.

Abnormalities of p53 mRNA in adult T-cell leukemia (ATL) were analyzed using reverse transcription-polymerase chain reaction-single strand conformation polymorphism analysis. Mutations were present in two of 12 ATL patients studied, but not in 3 cell lines immortalized by human T cell leukemia virus type 1 (HTLV-1) infection in vitro. Direct sequencing analysis of the p53 gene from these two patients revealed missense point mutations at codon 153 (arginine to histidine) or codon 220 (cysteine to tyrosine), respectively. Immunohistochemical analysis revealed the elevated expression of p53 proteins in ATL cells from a patient carrying the mutated p53 gene at codon 158. Neither gross rearrangement of p53 gene nor abnormal size of mRNA for the gene was demonstrated by Southern or Northern blot analyses. Thus, there is a mutated p53 in some patients with ATL. The involvement of abnormalities in some suppressor oncogenes may play a role in the development of ATL.

Base Sequence↗
PubMed1990

Blood pressure abnormalities as background roles for vertigo, dizziness and disequilibrium.

In 3 years, a total of 1,291 patients have undergone equilibrium examinations because of vertigo, dizziness and disequilibrium in the Otoneurological Division of Toyama Medical and Pharmaceutical University. Abnormal blood pressures (hypertension, hypotension and orthostatic hypotension) were found in 18.67% (241 patients). Hypotension was found significantly more often in peripheral vestibular disorders and hypertension in central nervous system disorders. Furthermore, the incidence of orthostatic hypotension was statistically higher in hypertensive patients than in hypotensive patients. Therefore, we conclude that blood pressure measurement by the Schellong test method in patients with vertigo, dizziness and disequilibrium is very important.

Adolescent↗
PubMed1988

DNA blotting analysis of human retroviruses in cerebrospinal fluid of spastic paraparesis patients: the viruses are identical to human T-cell leukemia virus type-1 (HTLV-1).

The structure of the integrated provirus in cell lines established from the cerebrospinal fluid (CSF) of patients with human T-cell leukemia virus type-1 (HTLV-1)-associated myelopathy (HAM) was analyzed. The digestion patterns with 3 restriction endonucleases, Sac I, Eco RI and PstI, of the proviruses integrated in T-lymphoid cell lines derived from the CSF of 4 HAM patients were similar to those of HTLV-1 from adult T-cell leukemia (ATL) patients. Integrated proviruses in one of these cell lines derived from the CSF were further analyzed in detail with 2 more restriction enzymes, BamHI and Sma I. The results indicate that the retrovirus found in lymphocytes of the CSF from patients with HAM are very similar, if not identical, to HTLV-1 found in the leukemic lymphocytes of ATL patients.

Cell Line↗
PubMed1988

Serial transplantation of an HTLV-I-transformed hamster lymphoid cell line into hamsters.

A hamster lymphoid cell line, HCT-2, transformed by human T-cell leukemia virus type I (HTLV-I) was serially transplanted for 9 passages in newborn hamsters. A total of 34 newborn hamsters inoculated intraperitoneally (i.p.) with 0.2-2 X 10(7) HCT-2 cells developed fatal lymphomas with dissemination to various organs within 5-10 days. The growth of i.p. inoculated HCT-2 cells was found to be dependent on the age of recipients: all 21 suckling hamsters inoculated when aged 5-10 days succumbed to disseminated lymphomas within 6-7 days, while 4 of 12 older hamsters inoculated at the age of 15-25 days developed less extensive disease with signs of tumor regression. To investigate the effect of immunosuppression on host resistance, 3 adult hamsters treated with anti-thymocyte serum were inoculated i.v. with 2-4 X 10(7) HCT-2 cells; all 3 developed fatal leukemias in 5-7 days. Irrespective of whether HCT-2 cells were inoculated into newborn, suckling, or adult hamsters, histopathological findings were similar, with frequent involvement of liver, spleen, lungs, kidneys, lymph nodes, blood, and bone marrow. Cells harvested from tumors and peripheral blood of some tumor-bearing hamsters could be readily recultured as cell lines. Chromosome analysis and Southern blot hybridization showed that tumors were caused by growth of HCT-2 cells.

Age Factors↗
PubMed1988

Nucleotide sequence analysis of a provirus derived from HTLV-1-associated myelopathy (HAM).

Human T-cell leukemia virus type 1 (HTLV-1) is known to be associated with adult T-cell leukemia (ATL). Recently, HTLV-1-associated myelopathy (HAM) was described as a neurological disease with which an etiological association of HTLV-1 is suspected. A provirus genome was cloned from a lymphoid cell line derived from the cerebrospinal fluid of a patient with HAM, in order to examine in detail the etiological virus associated with HAM. The nucleotide sequence of the long terminal repeat (LTR), protease, env and pX regions of the provirus shows over 97% homology with that of HTLV-1 derived from ATL. These results suggest that this provirus, derived from a patient with HAM, belongs to the same species as HTLV-1 derived from patients with ATL.

Amino Acid Sequence↗
PubMed1986

Projections of cervical nerves to the rat medulla.

The central course of dorsal root ganglia (DRG) fibers from C1, C2 and C3, and particularly, their brainstem terminations were studied in rats using anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). WGA-HRP was injected into the exposed DRG, and after 3 days the animals were sacrificed and sections of spinal cord and brainstem were processed with tetramethylbenzidine and examined for anterograde transport. Labeled fiber terminals were identified in the dorsal horn and the central cervical nucleus in the spinal cord, and in the intermediate nucleus, cuneate nucleus, external cuneate nucleus and the caudal portion of the nucleus of the solitary tract (NTS) in the brainstem. The projection of primary sensory fibers to the visceral NTS is suggestive of a functional relationship between upper cervical and vagal nerve afferents. The potential association of these nerves with clinical problems of headache and other cephalgias is of interest.

Afferent Pathways↗
PubMed1986

An application of the microcomputer as a generator of target movements for the eye tracking test (ETT).

We have developed a new system to produce target movements for our particular purposes using a microcomputer and 9-bit digital-to-analog converter. A continuously changing sinusoidal wave was produced to examine the relationship between the frequencies of target movements and smooth pursuit. A random sinusoidal wave was produced to make clear the predictive function of smooth pursuit.

Computers↗
PubMed1985

Hazard to endotracheal tubes by CO2 laser beam. Experimental report.

Ignition or combustion of the endotracheal tube during CO2 laser microlaryngo surgery may cause fatal lung disorders. We undertook an experiment on ignition and combustion of endotracheal tubes by CO2 laser beam and came to the following conclusions: (a) the silicon endotracheal tube was nonflammable; (b) the spiral endotracheal tube was also nonflammable; (c) a pulse wave was recommended and 3-second intervals were necessary; (d) four sheets of moist gauze were necessary to prevent cuff trouble, and (e) it was advisable to set the O2 concentration below 25% when using the silicon endotracheal tube.

Carbon Dioxide↗