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Biomedical subjects

A Murakami

Publications and source records attributed to A Murakami.

At least 235 records · Page 13Linked to original sources
PubMed1995

White matter changes caused by chronic solvent abuse.

PURPOSE: To examine the brain damage of solvent abusers in Japan, where pure industrial toluene is frequently abused. METHODS: Twenty solvent abusers 17 to 33 years of age with 7.2 +/- 4.0 years of abuse were examined with a 1.5-T MR imaging system. RESULTS: White matter hyperintensities in cerebrum, brain stem, and cerebellum on T2-weighted images were found in seven cases. The extent of white matter change was most clearly shown on proton density-weighted images. The patients with restricted white matter change and intermediate white matter change showed white matter hyperintensities in the brain stem and cerebellum on T2-weighted images, in some cases, with additional hypointensities in the corresponding T1-weighted images. These patients had mainly abused pure toluene. The patients with diffuse white matter change showed obvious brain atrophy, including hippocampal atrophy and thinning of the corpus callosum. These patients had mainly abused lacquer thinner. CONCLUSION: There are some patients with restricted but severe enough change to cause the neurologic symptoms in specific regions, such as the brain stem and/or cerebellum, before the brain atrophy becomes apparent. This suggests that the restricted white matter change represents not only an early change of diffuse white matter change, but at least in some cases also represents a qualitatively different change than that of diffuse white matter change. We suggest that pure toluene has a possible relation to this qualitative difference.

Adolescent↗
PubMed1995

MR in temporal lobe epilepsy: early childhood onset versus later onset.

PURPOSE: To study the relationship between the MR findings and the clinical features in temporal lobe epilepsy in childhood (less than 10 years of age). METHODS: MR studies were performed with a 1.5-T imager on 38 temporal lobe epilepsy patients receiving drug therapy at the psychiatric department. These patients were divided into two groups according to their age at onset (10 years or less, 11 years or more). The two groups were compared in terms of the MR findings and clinical features. RESULTS: The 11 younger-onset patients included 5 with a high-signal area attributed to mesial temporal sclerosis. Clinically, all of these 5 patients had a history of "complex" febrile convulsions, which sharply distinguished them from the older-onset group. CONCLUSION: The analysis suggests that complex febrile convulsions in infancy can be associated with high-signal areas on MR attributed to mesial temporal sclerosis.

Adolescent↗
PubMed1995

[The effects of dopa and oxygen on RNA concentrations in cultured chick embryonal retinal pigment epithelial cells].

We measured RNA and DNA concentrations in cultured chick embryonal retinal pigment epithelial cells to investigate the effects of dopa and oxygen on DNA and RNA synthesis. RNA/DNA ratios were decreased by addition of 250 microM dopa. Decrease of RNA/DNA ratios was suppressed when the oxygen concentrations were reduced from 20% to 10%. Incubation with medium containing 100 microM dopa increased RNA/DNA ratios in 10% oxygen. Exposure of retinal pigment epithelial cells to 250 microM dopa caused the decrease of RNA concentrations in the retinal pigment epithelial cells, which was ameliorated by lowering oxygen concentrations. However, the addition of 100 microM dopa in 10% oxygen stimulated retinal pigment epithelial cells and seemed to increase RNA concentrations.

Animals↗
PubMed1995

[The significance of invasion and vessel permeation in squamous cell carcinoma of the uterine cervix with invasion to a depth of 3 mm or less].

Nine-five patients with squamous cell carcinoma of the cervix invading to a depth of 3 mm or less (microinvasive carcinoma) were retrospectively viewed in regard to the depth of stromal invasion, the width of horizontal spread, confluent invasion, vessel permeation and lymph node metastasis. The type of treatment and outcome were also evaluated. Confluent invasion was found in 6 patient (6%), and vessel permeation in 9 patients (9%). Lymph node dissections were performed on 85 patients, but no lymph node metastasis was found, irrespective of the presence of confluent invasion or vessel permeation. Fifty-five patients with no vessel permeation were treated by conization or total or modified racial hysterectomy, and none had a recurrence of the disease. Our results suggest that the presence of confluent invasion or vessel permeation does not influence the incidence of lymph node metastasis, but data in the literature indicate that confluent invasion and vessel permeation are risk factors for lymph node metastasis and invasive recurrence of the disease. We conclude that patients with invasion of depth 3m or less, with no confluent invasion and no vessel permeation, can be treated by conservative operation.

Adult↗
PubMed1995

Mechanism of antisense effect studied by functionalized oligonucleotides.

In order to study the mechanism of antisense effects, various functional groups such as photocrosslinkers, fluorescent materials, and gold particles were introduced to antisense DNAs. Upon UV-irradiation, the hybrid between DNA and antisense DNA with a photocrosslinker was stabilized. The fluorescence microscopy and transmission electron microscopy (TEM) represented clear images of antisense DNA in the cultured cells. Fluorescent-labeled S-Oligos were recognized in the cytoplasm and especially on certain organs, which are not specified. TEM images of cultured cells treated with gold-conjugated S-Oligo suggested the mechanism of cellular uptake of antisense DNA.

Base Sequence↗
PubMed1994

Growth inhibition and induction of differentiation of t(8;21) acute myeloid leukemia cells by the DNA-binding domain of PEBP2 and the AML1/MTG8(ETO)-specific antisense oligonucleotide.

The translocation from chromosome 8 to chromosome 21, t(8;21), associated with acute myeloid leukemia results in production of an AML1/MTG8(ETO) fusion transcript. The product of the AML1 gene contains an evolutionarily conserved 128-amino acid region referred to as the "Runt domain," which is necessary for binding to DNA at the PEBP2 site. A fragment of the AML1 protein containing mainly the Runt domain and the antisense oligonucleotide complementary to the fusion transcript strongly inhibited the growth and induced differentiation of cell lines derived from acute myeloid leukemia containing t(8;21). These results indicate that the transcriptional regulation through the PEBP2 site is critically important for growth and differentiation of t(8;21) leukemic cells and that the product of the chimeric gene is responsible for the maintenance of the leukemic phenotype.

Acute Disease↗
PubMed1994

Separation and characterization of diastereoisomers of antisense oligodeoxyribonucleoside phosphorothioates.

Diastereoisomers of oligodeoxyribonucleoside phosphorothioates (OPT) up to a tetramer were effectively separated with reversed-phase high-performance liquid chromatography (reversed-phase HPLC) under optimized conditions. The diastereoisomers of OPT resulted in different retention times on the reversed-phase HPLC. From the results, we found that there were certain rules in the elution order of the diastereoisomers. The configurational sequence of the diastereoisomers was determined by digestion with nuclease P1, snake venom phosphodiesterase, and alkaline phosphatase. The diastereoisomers were studied by CD spectroscopy with respect to their conformation in aqueous media. We found that a large variation in the conformation of diastereoisomers exists. Results suggest that much attention should be paid to the diastereoisomerism in antisense molecules having chiral internucleotide linkages such as OPT.

Base Sequence↗
PubMed1994

The eta isoform of protein kinase C is localized on rough endoplasmic reticulum.

The eta isoform of protein kinase C, isolated from a cDNA library of mouse skin, has unique tissue and cellular distributions. It is predominantly expressed in epithelia of the skin, digestive tract, and respiratory tract in close association with epithelial differentiation. We report here that this isoform is localized on the rough endoplasmic reticulum in transiently expressing COS1 cells and constitutively expressing keratinocytes. By the use of polyclonal antibodies raised against peptides of the diverse D1 and D2/D3 regions, we found that immunofluorescent signals were strongest in the cytoplasm around the nucleus and became weaker toward the peripheral cytoplasm. Under immunoelectron microscopic examination, electron-dense signals were located on the rough endoplasmic reticulum and on the outer nuclear membrane which is continuous with the endoplasmic reticulum membrane. However, no signals were detected in the nucleus, inner nuclear membrane, smooth endoplasmic reticulum, Golgi apparatus, mitochondria, or plasma membrane. Treatment of the cells in situ with detergents suggested association of the isoform of protein kinase C with intracellular structures. By immunoblotting, a distinct single band with an M(r) of 80,000 was detected in whole-cell lysate and in rough microsomal and crude nuclear fractions, all of which contain outer nuclear membrane and/or rough endoplasmic reticulum. We further demonstrated the absence of a nuclear localization signal in the pseudosubstrate sequence. The present observation is not consistent with the report of Greif et al. (H. Greif, J. Ben-Chaim, T. Shimon, E. Bechor, H. Eldar, and E. Livneh, Mol. Cell. Biol. 12:1304-1311, 1992).

Amino Acid Sequence↗
PubMed1994

Effects of the conventional anticonvulsants, phenytoin, carbamazepine, and valproic acid, on sodium-potassium-adenosine triphosphatase in acute ischemic brain.

The effects of phenytoin, carbamazepine and valproic acid on alterations in sodium-potassium-adenosine triphosphatase activity during ischemia were studied in the rat brain. Pretreatment with phenytoin and carbamazepine prevented a reduction of this activity, which, without either treatment, was observed in the cerebral hemisphere exposed to 30-minute ischemia resulting from unilateral middle cerebral artery occlusion. Valproic acid, on the other hand, did not principally affect the ischemic impairment of this membrane-bound enzyme activity. These results lend support to the previously proposed use of phenytoin in cerebral ischemia, but also suggest the therapeutic availability of another common anticonvulsant, carbamazepine, for treatment of the insult.

Animals↗
PubMed1994

[A case report of coronary artery bypass grafting surgery with aprotinin in a patient undergoing chronic haemodialysis].

A 61-year-old patient who was receiving haemodialysis because of chronic renal failure developed unstable angina pectoris with three vessel disease. We performed successful coronary artery bypass grafting, using aprotinin to reduce blood loss. Blood loss during the operation was 750 ml, and during a 6 hour period after the operation it was 150 ml. This amount seemed to be small. No adverse clinical effects attributable to aprotinin were seen, and urine volume and plasma creatinine were not different before and after the operation. In summary, aprotinin is useful adjunct to open heart surgery in chronic haemodialysis patients.

Aprotinin↗
PubMed1994

[The management of mediastinitis after cardiac surgery].

Of 1067 consecutive patients who underwent cardiac surgery from 1985 to 1992, 19 (1.7%) patients experienced sternal wound complications. All patients required operative intervention with positive bacterial cultures. Before 1990, a group of 13 patients were treated by continuous closed irrigation with dilute povidone-iodine solution. Four patients died (30%). In another group of 6 patients who received omental or pectral muscle flap transfer after 1990, 2 patients died (33%). The mean duration of hospitalization for mediastinitis was 63 days in this group, which was significantly shorter than that of the former group (105 days). From these experiences, we conclude that omental or pectral muscle transfer is an excellent method of management for mediastinitis after cardiac surgery, and is better than continuous closed irrigation method.

Adult↗
PubMed1994

[Comparison of long-term clinical results and cost-effectiveness of percutaneous coronary angioplasty and coronary artery bypass grafting].

Cost-effectiveness was studied in 313 cases who had PTCA and 161 cases who had CABG as a first measure of interventional therapy for their coronary heart disease. Follow-up time ranged from 2 years to 5 years and 9 months with a mean interval of 3 years and 10 months. In the PTCA group a mean of 1.33 successfully dilated vessels/patient was obtained, but a total of 100 additional PTCA or bypass surgery procedure was necessary in the follow-up period. In the CABG group a mean of 2.60 patent grafts/patient was obtained. Mean length of hospital stay and charge was 21.9 days and 2,071 thousand yen in the PTCA group, and 82.2 days and 5,122 thousand yen in the CABG group through the entire follow up period. Cardiac event-free survival rate was significantly worse in the PTCA group. In the subgroup of two vessel disease, mean number of successfully dilated targets or patent grafts was 1.32 in the PTCA group and 1.88 in the CABG group. Total length of hospital stay and charge was 24.1 days and 2,352 thousand yen in the PTCA group and 86.2 days and 4,903 thousand yen in the CABG group. Cardiac event-free survival rate was significantly worse in the PTCA group. In the subgroup of three vessel disease, PTCA yielded 1.34 dilated target vessels, whereas CABG 2.66 patent grafts, which was two times more than the former one. Total length of hospital stay and charge was 32.7 days and 2,612 thousand yen in the PTCA group, and 82.4 days and 5,225 thousand yen in the CABG group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Identification of positive and negative regulatory elements involved in the retinoic acid/cAMP induction of Fgf-3 transcription in F9 cells.

The proto-oncogene Fgf-3 has been implicated as an important signalling molecule in vertebrate development. In the mouse, it is expressed for a limited time at a multitude of sites from embryonic day 7 to birth. Transcription of Fgf-3 initiates at three promoter regions resulting in the generation of various mRNAs which nevertheless all encode the same protein products. A 1.7kb DNA fragment which encompasses these regions was joined to the CAT reporter gene and shown to function as a promoter in embryonal carcinoma cells. In stable transfectants the promoter retains its retinoic acid inducibility, initiating transcription at the same cap-sites as the endogenous gene. In differentiated F9 cells, transient transfection of progressive and targeted deletion mutants of the promoter region has revealed at least two positive and three negative regulatory elements. With one exception, loss of these elements was shown to dramatically affect promoter activity in stable transfectants of F9 cells. However the promoter remained inducible by retinoic acid to differing degrees, apart from deletions encompassing PS-4A which essentially abolished promoter activity in both undifferentiated and differentiated cells. The sequences of these potential regulatory regions were further defined using DNase-I footprinting, revealing some similarities to consensus binding sites for known transcription factors.

Animals↗