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Biomedical subjects

T Kawakami

Publications and source records attributed to T Kawakami.

At least 361 records · Page 20Linked to original sources
PubMed1990

Molecular analysis of a chromosomal translocation, t(9;14)(p13;q32), in a diffuse large-cell lymphoma cell line expressing the Ki-1 antigen.

We have studied a translocation, t(9;14)(p13;q32), in a diffuse large-cell lymphoma cell line, KIS-1, that expresses the Ki-1 (CD30) antigen. Molecular cloning of the immunoglobulin heavy-chain locus (IGH) of this cell line revealed an unknown segment linked 5' to IGH. The breakpoint on chromosome 14 was 265 base pairs downstream from the 3' border of the JH6 joining gene segment. Class switch recombination deleted most of the constant genes of IGH (CH) and juxtaposed the C alpha 2 gene downstream of the translocation junction. Analysis of somatic cell hybrids and in situ chromosomal hybridization demonstrated that the translocated segment was normally located at band p13 of chromosome 9. The chromosome 9 sequences were transcriptionally active, giving rise to transcripts of approximately 11 kilobases. The KIS-1 cells seemed to have a small quantity of chimeric transcripts containing both chromosome 9 and C alpha 2 sequences.

Antigens, CD↗
PubMed1990

Differential inhibition of the T cell activation pathway by dexamethasone and cyclosporine.

We examined the inhibitory capacity of dexamethasone (DEX) and cyclosporine (CsA) on T cell activation using various accessory cell (AC)-dependent and AC-independent stimuli. We found that CsA strongly inhibited T cell activation in each of the assays used: allogeneic T cell stimulation, phorbol myristate acetate plus concanavalin A, PMA plus anti-CD3 monoclonal antibody (2C11), or PMA plus ionomycin (IONO) T cell activation. DEX was a potent inhibitor of allogeneic stimulation and of the PMA+Con A- or PMA + 2C11-induced T cell stimulation. PMA + IONO stimulation, however, was not affected by DEX. When inhibition occurred, both drugs suppressed [3H]TdR incorporation, IL-2 production, and IL-2 mRNA accumulation, indicating that the sites of interference of these drugs in the T cell activation pathway are located proximal to IL-2 mRNA accumulation. However, the difference in the effects of DEX and CsA in PMA + IONO stimulation suggests that DEX and CsA differentially affect T cell activation.

Animals↗
PubMed1990

[Bone marrow transplantation for girls with aplastic anemia utilizing modified field of total lymphoid irradiation and cyclophosphamide: with emphasis on the field of pelvic cavity].

A preparative regimen for allogeneic bone marrow transplantation, consisting of total lymphoid irradiation (TLI) with 750 cGy and cyclophosphamide (CY), was used in five girls with aplastic anemia. All patients received bone marrow from HLA matched/mixed lymphocyte culture negative siblings. In our regimen the "inverted Y" field to irradiate the pelvic nodes was modified, which did not include the whole pelvic cavity in an attempt to protect the ovaries from irradiation. Although some of the pelvic nodes was supported not to be irradiated in order to protect the ovaries, engraftment occurred in all five patients including four who had been transfused prior to transplantation. All five are alive from 47 days to 1378 days (median 285 days) after transplantation without transplantation-associated complications. The calculated dose to the ovaries was sixteen percent of the entire dose of the regimen. Both of the two evaluable patients that had received transplantation just before or during the puberty are developing normal sex maturity including menstruation. This study suggests that our preparative regimen is effective not only for engraftment of the donor marrow but also for protecting the ovaries from irradiation.

Adolescent↗
PubMed1990

[Basic and clinical studies on a new method for detecting anti-Mycoplasma pneumoniae antibody, using high density particles].

We developed a new method for detecting anti-Mycoplasma pneumoniae antibody, using high density particles (HDP). We characterized the HDP, and also studied the clinical applicability of the HDP agglutination method (HDPA). HDP were uniform, spherical particles, having a specific gravity of 2.0 and a mean particle volume of 18 fl. Adsorption of IgG by HDP was approximately 2 times that by polystyrene latex. The sensitized antigen to the HDP, extracted from the Mycoplasma pneumoniae (Mac strain) bound specifically to the anti-Mycoplasma pneumoniae antibody. With HDPA, the antibody was determined within 30 minutes, which was more rapid than with other routine methods such as complement fixation test, passive hemagglutination test and particle agglutination test (PA). HDPA showed excellent correlation with PA. However, the titers with HDPA were generally 2 to 5 tubes higher than that with PA. A follow-up study on 7 cases of mycoplasma pneumonia revealed remarkably high titers of anti-Mycoplasma pneumoniae antibodies in the acute phase of mycoplasma pneumonia by HDPA, compared to that by PA. HDPA is highly sensitive and specific test for detection of anti-Mycoplasma pneumoniae antibody, and useful for rapid diagnosis of mycoplasma pneumonia.

Agglutination Tests↗
PubMed1990

[Statistical studies of student clinical practice. 1. Clinical practice of operative dentistry from 1983 to 1989].

Clinical practice has been assigned as a final and very important aspect of study and practice of dental education. In our university, the students are exposed the clinical practice from the latter term of fifth year. This report investigated the protocols of clinical cases from the first to the seventh class of graduates. The results obtained were as follows: 1) The graduates of first class averaged 9 clinical cases. This decreased with the years and the fourth class averaged 5.5 cases. From the sixth class simulator training and mutual practice among the students was introduced and the total average of seventh class was 5.1 cases. 2) The dental practice centers on restoration and 20 percent of all cases were amalgam fillings from the first to four the class. However this decreased from the fifth class and does not take place at present. Composite resin restorations increased. Cast restorations occupied 20 percent of all cases and the proportion hasn't changed. 3) Clinical cases of graduates of fifth class who were first to include treatment between students averaged 7 cases. Mutual treatment practice is useful because of the increase exposure to clinical practice.

Clinical Clerkship↗
PubMed1990

[Clinical statistics of the bladder tumor--survival rates of 325 cases].

To study the relationship between clinical features and prognosis of the bladder tumor, 325 patients who were treated in our hospital were analyzed. The overall 5-year and 10-year actual survival rates were 65% and 51%. There was no statistical significance in the actual survival rate between the single and multiple tumor group. Although, there was a significant difference in tumor size, tumor growing type and the mode of treatment. The ten-year survival rates for grades 1, 2 and 3 cases were 76%, 57% and 18%, respectively. There was a significant difference between grades 1 and 3 (p less than 0.001) and grades 2 and 3 (p less than 0.001). The ten-year survival rates for stages Ta, T1, T2, T3a, T3b and T2-4 M1 were 79%, 68%, 43%, 0%, 19% and 5%, respectively. There was a significant difference between the Ta, 1 and T2-4 group (p less than 0.001).

Adult↗
PubMed1989

Introduction of macromolecules into primary cultured neuronal cells by fusion with erythrocyte ghosts.

The macromolecules were injected into primary cultured neuronal cells by fusion with human erythrocyte ghosts containing macromolecules. The injection efficiency was about 30% and 80% of the cells extended neurites like normal neuronal cells. In order to succeed in this method, phytohaemagglutinin E and polyethylene glycol 1000 were essential, and monolayer culture cells were used.

Cell Fusion↗
PubMed1989

Dexamethasone regulation of the expression of cytokine mRNAs induced by interleukin-1 in the astrocytoma cell line U373MG.

BSF-2/IL-6, GM-CSF and IL-1 beta mRNAs were induced by recombinant IL-1 in human astrocytoma cell line U373MG. The induction of BSF-2/IL-6 and IL-1 beta mRNAs did not require de novo protein synthesis while that of GM-CSF mRNA required a newly synthesized protein. Dexamethasone inhibited the induction of these cytokine mRNAs by IL-1. This process seems to require continued protein synthesis. These results suggest that the production of these cytokines are positively and negatively controlled by IL-1 and glucocorticoids, respectively, in astrocytes.

Astrocytoma↗
PubMed1989

REM sleep and bradyarrhythmia episodes in rats.

The relationship between rapid eye movement (REM) phasic events and bradyarrhythmia was investigated in five male Wistar rats. ECGs, EEGs (frontal cortex and dorsal hippocampus), and electrooculograms were monitored continuously for 6 days. Sleep states were classified as alertness, slow-wave sleep, or paradoxical sleep, and the frequency of the REM burst was measured to evaluate the REM density. Bradyarrhythmias, such as SA block or AV block, were observed in each rat and were divided into two groups: group A, bradyarrhythmias with a duration greater than 5 sec; and group B, duration less than 5 sec. For a period of 33 days, the five rats showed alertness, slow-wave sleep, and paradoxical sleep 6,481, 6,483, and 1,523 times; bradyarrhythmia incidents in each sleep stage were 0.35%, 0.03%, and 22.4%, respectively. The incidence of bradyarrhythmia episodes increased with REM density, and 78.5% of the episodes appeared related to the REM bursts. The latency between the REM bursts and bradyarrhythmia was as follows: type A bradyarrhythmias, 2.17 +/- 0.41 sec; type B, 3.78 +/- 0.63 sec. These results suggest close association of bradyarrhythmia occurrence with REM phasic events.

Animals↗
PubMed1989

Establishment and partial characterization of a radiation-induced canine monocytic leukemic cell line (RK9ML-1).

A myeloid leukemic cell line, designated RK9ML-1, was established from a dog with acute radiation-induced monocytic leukemia. Based on cytochemical stains which reacted positively only with nonspecific esterase, morphological and ultrastructural characteristics which indicated the presence of phagocytic vacuoles and lysosomal bodies, and cell surface properties which indicated the presence of Fc receptors, all the findings support that RK9ML-1 is of monocytic lineage. Chromosomal analysis of the cell line indicated the cells to be hypodiploid with acrocentric autosomes characteristic of canine cells.

Animals↗
PubMed1989

Giant cell reaction to ameloblastoma: an immunohistochemical and ultrastructural study of a case.

Histopathologic, immunohistochemical, and ultrastructural features of the giant cells appearing in the tissue surrounding an ameloblastoma are presented. These giant cells exhibited strong activity of a highly stable form of acid phosphatase, and were positive for alpha-1-antichymotrypsin. Ultrastructurally, the cytoplasm of the giant cells contained numerous mitochondria, and the cell membrane was comparatively smooth. Therefore, it is proposed that these multinucleated giant cells are reactive to the invasion of ameloblastoma and are histiocytic in origin.

Ameloblastoma↗
PubMed1989

Influence of electrical stimulation of the limbic structure on adrenocortical steroidogenesis in hypophysectomized rats.

The effects of electrical stimulation of the medial amygdala (AMYG) and dorsal hippocampus (DHPC) on the rates of 14C transfer from 14C-1-acetate into adrenocortical steroids in adrenal slices of hypophysectomized rats were investigated. The 14C transfer rates into corticosterone were increased by stimulation of the AMYG and DHPC. The 14C transfer rates into cortisol were increased by the AMYG stimulation but were not altered by the DHPC stimulation. From these results, it might be suggested that these limbic structures were involved in the regulation of adrenocortical steroidogenesis without participation of the pituitary.

Adrenal Cortex Hormones↗
PubMed1989

The actin domain of Gardner-Rasheed feline sarcoma virus inhibits kinase and transforming activities.

The transforming gene product, P70gag-actin-fgr, of Gardner-Rasheed feline sarcoma virus (GR-FeSV) is a single polypeptide composed of regions derived from cellular and viral genes. Gamma actin and c-fgr genes are the two known cellular components of the GR-FeSV genome. In the present study, sequences representing each cell-derived gene were deleted and the resulting constructs were tested for transforming activity by transfection of NIH 3T3 cells. Constructs lacking a portion of the c-fgr proto-oncogene failed to induce focus formation, demonstrating the essential nature of this component for GR-FeSV oncogenic activity. In contrast, the construct lacking the actin domain was more active than GR-FeSV DNA in transformation assays. Protein specified by the actin deletion mutant possessed a 2.4-fold greater specific protein-tyrosine kinase activity compared with that of the wild-type gene product. Furthermore, the actin domain had no detectable effect on the ability of the fgr kinase to associate with cytoskeleton or to phosphorylate unique cellular proteins on tyrosine. Our findings demonstrate that the actin domain inhibits focus formation and impairs protein-tyrosine kinase activity.

Actins↗
PubMed1989

Association of p60fyn with middle tumor antigen in murine polyomavirus-transformed rat cells.

Rabbit antisera raised against human FYN-specific peptides were used to evaluate the expression of the fyn gene product in normal and murine polyomavirus middle tumor antigen (MTAg)-transformed rat cells. The antisera were capable of detecting p60fyn in both normal and MTAg-transformed cells. Two different antisera directed against unique p60fyn sequences were found to detect p60fyn-MTAg complexes in cell lysates from the MTAg-transformed cells. The MTAg molecules immunoprecipitated by FYN antisera were phosphorylated on tyrosine during immune-complex kinase reactions at sites similar to those found on MTAg in complexes with pp60c-src. Whereas the abundance of p60fyn was estimated to be less in the MTAg-transformed cells than in their normal counterparts, the specific activities of p60fyn molecules in the normal and transformed cells were similar.

Amino Acid Sequence↗
PubMed1989

Noise exposure and permanent hearing loss of textile workers in Thailand.

Hearing loss induced by noise exposure in a large scale textile mill (number of workers = 1,611) in Thailand was investigated on the basis of interviews, noise measurements, and audiometric tests. The frequency of subjective symptoms relating to noise exposure was higher in the weavers than among other mill workers and office workers. The average noise levels in the weaving sections and other sections were 101.3 +/- 2.7 dBA and 89.8 +/- 5.3 dBA, respectively. The results of the audiometric tests revealed the significantly higher noise-induced hearing loss among workers in the weaving section compared to other mill workers and office workers (P less than 0.01). Among weavers, hearing levels decreased with the longer years of work. Concerning personal noise protective devices, 38.6% of the weavers never used them. It was concluded that hearing loss status in the workers of the mill was serious. Improvements by means of integrated work organization activities were recommended.

Adult↗