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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 487 records · Page 27Linked to original sources
PubMed1997

[New method for closure of median sternotomy: usefulness of barbed staple].

In this report, 15 cases using straight staple (group A) and 35 cases using barbed staple (group B) were compared for the purpose of investigating efficacy for median sternal closure. The staples were placed by a Stapilizer powered metaphyseal staple system following partial transsternal fixation with two wires. As a means of assessing the status of back out, which is a major cause of poor fixation, the back out rate (BOR) was measured on lateral sternal radiographies. The average BOR was found to be 33.8% in group A and 21.2% in group B (p < 0.001). Barbed staples seemed to be more useful for sternal fixation than straight staples. This method of applying barbed staples had the advantages of speed, ease of insertion and noninvasion of the retrosternal region. It should be recommended in cases with severe adhesion of the retrosternal region after coronary operation.

Adult↗
PubMed1997

Localization of manganese superoxide dismutase in the cerebral cortex and hippocampus of Alzheimer-type senile dementia.

Manganese-superoxide dismutase (Mn-SOD) was localized in the cerebral cortex and hippocampus of patients with Alzheimer-type senile dementia (ATD) by immunocytochemistry and the relationship of Mn-SOD with two major pathological features of ATD, i.e., senile plaques and neurofibrillar tangles (NFTs), was examined. Many astrocytes in senile plaques exhibited strong immunoreactivity for both Mn-SOD and glial fibrillar acidic protein (GFAP) on serial section analysis. This suggests that Mn-SOD scavenger system is associated with the formation of senile plaques. On the other hand, Mn-SOD immunoreactivity was not significant in NFT-loaded neurons.

Aged↗
PubMed1997

[A neonate born to a mother with acute promyelocytic leukemia treated by all-trans retinoic acid].

We report a female neonate delivered in week 32 of gestation by a mother who had acute promyelocytic leukemia (APL) treated by all-trans retinoic acid (ATRA). APL was diagnosed in week 29 of gestation and was treated with ATRA from week 30. Physical examination and laboratory tests showed no abnormalities at birth. The girl has since shown normal development, with no peripheral blood abnormalities at 2 years old. Hypersegmented neutrophils, which often appear during ATRA treatment, were seen in the peripheral blood of the mother and cord blood but not peripheral blood of the neonate on the day of birth. ATRA is known to cross the placenta, and has been revealed to be teratogenic in animal studies. There have been eight neonates born to the mothers with APL who were treated with ATRA during pregnancy. All infants, including this one, have shown normal growth without any complications.

Adult↗
PubMed1997

[Dynamic susceptibility contrast MRI with echo planar imaging using 1.0T system: comparison of different EPI sequences].

Dynamic susceptibility contrast MRI has been performed using the gradient echo sequence on conventional MR imagers. On echo planar imaging (EPI) devices, not only gradient-echo EPI but also spin-echo EPI allow for the monitoring of contrast agent-induced changes in susceptibility. The purpose of this study was to evaluate the contribution of each EPI pulse sequence to susceptibility-induced delta R2(*) through the first pass of a bolus of Gd-DTPA. Thirty healthy volunteers were examined with a 1.0T superconducting MRI unit (IMPACT, Siemens) using EPI. For dynamic susceptibility contrast MRI, we used gradient echo EPI (TE = 60), spin echo EPI (TE = 60) and asymmetric spin echo EPI (TE = 88). Regional relative CBV (rrCBV) maps were generated. On the rrCBV map generated with gradient echo EPI, the high-intensity area of the brain surface was more conspicuous than that generated with spin echo EPI. The rrCBV map generated with asymmetric spin echo EPI represented the contrast between those generated with spin echo EPI and gradient echo EPI. The rrCBV rate between gray matter and white matter with gradient echo EPI was significantly higher than that with spin echo EPI. We suggest that the rrCBV map calculated with spin echo EPI tends to reflect capillary blood volume and the rrCBV map calculated with gradient echo EPI tends to reflect total blood volume.

Adult↗
PubMed1997

[Evaluation by visiting nurse in end-stage cancers--family questionnaire for patients who died after visiting nurse].

Since April 1994, we have provided visiting nurse care for patients with end-stage of cancers. A questionnaire was sent to 72 families of patients who died of cancer and who received after visiting nurse care. The response rate to the questionnaire was 76.4% (55 patients). One group of 27 patients died at home (Group A), and the other group of 28 patients died in the hospital (Group B). Patients who knew they had cancer accounted for 85.2% in Group A, and 57.1% in Group B. Of all patients, 69.1% desired home nursing, with 77.8% in Group A, and 60.7% in Group B. The satisfaction of families with the visiting nurse was evaluated. In Group A, satisfaction was 66.7% and relative satisfaction was 18.5%. In Group B, satisfaction was 50.0% and relative satisfaction was 25.0%. Satisfaction of patients with the place of death was 81.5% in Group A, and 35.7% in Group B. Many families wished to have the nurse visit 2 times a week, and an hour at each visit. The great mental burden on the families who provide home care for patients with terminal cancer was clear for the questionnaire. Arrangement for a support system for patients and families, through visiting nurse services, is necessary in our hospital.

Community Health Nursing↗
PubMed1997

[Binocular functions in amblyopia and strabismus].

Regarding the changing trends in the concept, definition, etiological classification, and criteria for diagnosis of amblyopia, we reviewed a total of 4,693 cases of amblyopia seen during the past 37 years. The amblyopia was divided into four types: strabismic, anisometropic, ametropic, and form vision deprivative. There was a definite trend for the incidence to decrease and for the diagnosis to be made during earlier age in recent years. Although favorable recovery of visual acuity is obtained after treatment of amblyopia and strabismus, there are difficulties in obtaining good binocular functions in early-onset amblyopia and strabismus. This feature was evaluated in regard to motion perception asymmetry (MPA) and binocular depth from motion (DFM). Many cases of early-onset amblyopia and strabismus showed no disparity stereopsis, or position stereopsis, in spite of the presence of DFM. The MPA appeared to be closely related to early-onset esotropia regardless of age, while it disappeared and motion perception became symmetric 4 to 5 months after birth in normal infants. The DFM seemed to play an important role in maintaining good motor alignment for several years after surgery. I developed a checkerboard pattern stimulator in 1978. This method proved to be useful in developing binocular functions and motor alignment by applying simultaneous bifoveolar stimulation and anti-suppression. Extensive exposure to the stimulation was essential for therapeutic success.

Adolescent↗
PubMed1997

[Dictyostelium].

Explore the source record for details and available documents.

Animals↗
PubMed1997

Synthesis of novel dioxane nucleosides having two bases, physico-chemical properties, and their biological activities.

Novel dioxane nucleosides having two bases, 2(R)-(5-fluorouracil-1-yl)-5(R)-hydroxymethyl-3(R)-(uracil-1-yl)-1,4-dioxane (7a) and 2(S)-(5-fluorouracil-1-yl)-5(R)-hydroxymethyl-3(R)-(uracil-1-yl)-1,4-dioxane (7b) were synthesized from uridine to develop a new category of nucleoside for therapeutic use. Some derivative of precursors of the nucleoside were also synthesized and several compounds synthesized were tested antitumor activity using human gastric cancer cell lines in culture.

Antimetabolites, Antineoplastic↗
PubMed1997

Synthesis and evaluation of oligonucleotides incorporating novel artificial nucleobases for the selective formation of non-natural type triplexes.

Regulation of specific gene expression by the sequence specific triplex formation has been expected as a new biological tool or a new therapeutic method in the so-called antigene strategy. As native nucleobases form triplexes only within homopurine-homopyrimidine duplexes, expansion of the target sequences to general ones has been desired. We have previously reported the selective formation of base triplets by the non-native nucleobases (1, 2) with a CG or a TA base pair, respectively, in the organic solvent. In this paper, we wish to report the synthesis of the new non-native bases (3, 4, 9-11) and their incorporation into the triplex-forming oligonucleotides (TFOs), as well as their ability of triplex formation.

Base Composition↗
PubMed1997

Novel cross-linking reaction of oligonucleotides incorporating new base analogs with selective reactivity toward cytidine.

2-Amino-6-vinylpurine analog (1) has been proven to react with cytidine and guanosine in a model reaction of cross-linking. However, its incorporation into the ODNs was unsuccessful because of the high reactivity of its vinyl group. A new precursor for 1, 2-amino-6-[2-(phenylthio)ethyl]purine (2), was designed so as to generate the reactive vinyl group after introduction into the oligomers. In this paper, synthesis of ODN containing 2, easy generation of the vinyl group within the oligomer, and interstrand cross-linking between the ODN incorporating 1 and the target DNA, are described.

Base Sequence↗
PubMed1997

Affinity capillary electrophoresis using DNA conjugates.

An oligonucleotide ((dT)12)-immobilized capillary was prepared for the affinity capillary electrophoresis of DNA. Oligonucleotides ((dA)6 and (dT)6) which had the same chain length but had different base composition were separated in high resolution in the presence of Mg2+ ion. Whereas (dA)6 eluted slightly earlier than (dT)6 in a conventional polyacrylamide-coated capillary, the order of their mobilities was reversed in the (dT)12-modified system, suggesting the complementary hydrogen bondings between (dA)6 and the immobilized (dT)12.

Base Composition↗
PubMed1996

Inhibition of metastasis by a dialysable factor in fetal bovine serum in B16 melanoma cells.

Fetal bovine serum (FBS) supplemented to the culture medium inhibited the metastasis of B16BL6 melanoma cells in a dose-dependent manner. This metastasis-inhibiting activity was accompanied by growth-promoting activity, up to the concentration of 10% FBS. However, among the clones isolated from B16BL6 cells, there were clones in which FBS significantly inhibited the metastasis without promoting their growth. Dialysis (cutoff M.W. 8000 Da) removed the metastasis-inhibiting activity but not the growth-promoting activity from FBS. These results indicate that FBS has metastasis-inhibiting activity which is independent of growth-promoting activity, and that the metastasis-inhibiting activity is carried by molecules removed by dialysis.

Animals↗
PubMed1996

Suppression of sialyl Lewis X expression and E-selectin-mediated cell adhesion in cultured human lymphoid cells by transfection of antisense cDNA of an alpha1-->3 fucosyltransferase (Fuc-T VII).

The antisense cDNA approach was used to identify the endogenous fucosyltransferase species responsible for synthesis of the sialyl Lewis X (NeuAcalpha2-->3 Galbeta1-->4[Fucalpha1-->3]GlcNAcbeta1-->R) determinant in human lymphoid cells. The cultured human adult T-cell leukemia cell line, ED40515-N, expressed the message of alpha1-->3 fucosyltransferase (Fuc-T) IV and VII, with a low level of the Fuc-T III and VI message, and manifested the sialyl Lewis X as well as Lewis X (Galbeta1-->4 [Fucalpha1-->3]GlcNAcbeta1-->R) determinant at the cell surface. Transfection of this cell line with the pRc/CMV vector containing an antisense human Fuc-T VII construct (pRc/CMV/5'FT7AS) resulted in a significant decrease of endogenous Fuc-T VII message and a marked reduction in the cell surface expression of sialyl Lewis X determinant as well as a reduction in the enzymatic activity of alpha1-->3 fucosyltransferase against sialylated type 2 chain substrate. This was accompanied by diminution of cell adhesive activity toward E-selectin on interleukin-1beta-treated endothelial cells. These results indicated that the synthesis of the sialyl Lewis X determinants that were functionally active as E-selectin ligands was mainly mediated by Fuc-T VII in these lymphoid cells. On the other hand, the message of Fuc-T IV showed no significant change in the transfectant clones, and the surface expression of the Lewis X antigen as well as the enzymatic activity of alpha1-->3 fucosyltransferase against non-sialylated type 2 chain substrate was well preserved. The clear contrast between the diminished expression of sialyl Lewis X and the conserved manifestation of Lewis X in the transfectant clones suggested that the synthesis of sialyl Lewis X and that of Lewis X are independently regulated by different fucosyltransferases in human lymphoid cells. Fuc-T VII must be involved in the synthesis of sialyl Lewis X, while the synthesis of Lewis X is mediated by an enzyme other than Fuc-T VII, most probably Fuc-T IV.

Adult↗
PubMed1996

Nitrergic cerebral vasodilatation provoked by the periaqueductal grey.

The present study evaluated the contribution of nitric oxide to the increase in cerebral cortical blood flow that is provoked by chemical stimulation of the caudal third of the lateral periaqueductal grey (PAG), employing 48 anaesthetized rats with cervical cordotomy. Following topical application over the cortical surface, the inhibitor of nitric oxide synthase NG-nitro-L-arginine inhibited the response stereospecifically and achieved its maximal effect at 1 mM, when the response was reduced to 47 +/- 16% (n = 16). Since the PAG represents a principal site for the central organization of defence reactions, we suggest that nitric oxide may play a definitive role in the central regulation of the cerebral circulation, thereby participating in such important biological processes as the defensive reflex activity.

Animals↗
PubMed1996

Sterol-dependent transcriptional regulation of sterol regulatory element-binding protein-2.

We show in this manuscript that expression of the mRNA for sterol regulatory element-binding protein-2 (SREBP-2) is regulated by the cellular sterol level in cultured HeLa cells. We have cloned the 5'-flanking region of the gene encoding human SREBP-2. Characterization of this region shows the minimum 50-base pair segment, which contains a 10-base pair sterol regulatory element 1 (SRE-1) identical to the one in the human LDL receptor promoter, confers sterol responsiveness when fused to the luciferase reporter gene. Enforced expression of the truncated SREBP-2 protein (amino acid residues 1-481) also shows that this upstream segment contains the information required for transcriptional activation. The luciferase assays using mutant versions of the reporter genes reveal that the sterol-dependent transcriptional regulation is mediated by two nearby motifs, the SRE-1 and the NF-Y binding site (the inverted CCAAT box, ATTGGC); the latter is reported to play a critical role in sterol-dependent regulation of 3-hydroxy-3-methylglutaryl-coenzyme A synthase and farnesyl diphosphate synthase genes (Jackson, S. M., Ericsson, J., Osborne, T. F., and Edwards, P. A. (1995) J. Biol. Chem. 270, 21445-21448). Gel mobility shift assays demonstrate that the transcription factor NF-Y truly binds to the ATTGGC sequence. These findings suggest that the activity of SREBP-2 is controlled not only post-translationally by proteolytic activation of the precursor protein but also transcriptionally by itself together with NF-Y.

Binding Sites↗