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Biomedical subjects

M Fukuda

Publications and source records attributed to M Fukuda.

At least 685 records · Page 38Linked to original sources
PubMed1994

Localization of dipole by boundary element method in three dimensional reconstructed monkey brain.

The boundary element method was applied to 3-dimensionally reconstructed monkey brain to localize a current source generator (dipole) of somatosensory evoked potentials (SEPs) recorded from epidural electrodes under assumption that a brain is electrically homogeneous and is bounded by a high resistant substance (skull). Absolute mean deviation of estimated dipoles from actual dipoles artificially generated by electrical stimulation at known coordinates in the brain were within 1-3 mm. The estimated dipole computed from SEPs by right median nerve stimulation at latency of P10-N10 waves was located in area 3b of the somatosensory hand area in monkey. Our data suggest that this technique of locating dipoles by the boundary element method applied to a reconstructed brain allows accurate determination of the 3-dimensional coordinates of a dipole.

Algorithms↗
PubMed1994

Dipole tracing of monkey somatosensory evoked potentials.

Current source generators (dipoles) of somatosensory evoked potentials (SEPs) in response to electrical stimulation of the median nerve in anesthetized monkeys were localized by the dipole tracing method (DT) which can approximate surface potential distributions to an equivalent dipole. The locations and latencies of dipoles estimated by DT were confirmed by recording multiple unit activities from the parietal cortices of the same monkeys investigated by DT. Loci of generators for each SEP component were: P10 and N10, area 3b; P12, areas 1 and 2; P18, area 5. The results indicate that DT could trace the successive movement of generators of SEPs from the primary somatosensory area to area 5, which has been suggested in neuroanatomical studies to be part of the hierarchical sequence of somatosensory processes.

Animals↗
PubMed1994

Carbohydrate structures of recombinant soluble lamp-1 and leukosialin containing sialyl Le(x) terminus.

Recombinant soluble lamp-1 and soluble leukosialin can be produced from CHO cells which express sialyl Le(x) structures after stable transfection of fucosyltransferase-III. It was shown previously that those soluble lamp-1 and leukosialin are potent inhibitors for E-selectin-mediated adhesion of human colonic tumor cells (Sawada, R.; Tsuboi, S.; Fukuda, M. J. Biol. Chem., 1994, 269, 1425). In the present study, we have determined the amount of the sialyl Le(x) structure present in recombinant, soluble lamp-1 and soluble leukosialin. CHO cells were metabolically labeled with [3H]-galactose and recombinant soluble lamp-1 and leukosialin were purified from the spent medium. Glycopeptides containing N-glycans derived from lamp-1 were fractionated by sequential lectin affinity chromatography. Similarly, O-glycans released from leukosialin were fractionated by Bio-Gel P-4 gel filtration. The terminal structures of carbohydrate chains were determined by sequential digestion with specific glycosidases. The results clearly indicate that soluble lamp-1 contains much more sialyl Le(x) structure than soluble leukosialin. Considering that soluble leukosialin and lamp-1 are almost equally effective as inhibitors for E-selectin-mediated adhesion, the results strongly suggest that densely clustered O-glycans are better presenters for E-selectin ligands than N-glycans.

Animals↗
PubMed1994

A novel zinc finger protein, zic, is involved in neurogenesis, especially in the cell lineage of cerebellar granule cells.

To clarify the mechanism of cerebellar development, we have cloned a gene, named zic, encoding a zinc finger protein that is expressed abundantly in granule cells throughout development of the cerebellum. zic has a significant homology to the zinc finger domain of the Caenorhabditis elegans tra1 gene, the Drosophila cubitus interruptus Dominant gene, and the human GLI oncogene. An in situ hybridization study revealed that zic showed a restricted expression pattern in the granule cells and their putative precursor cells. It is also expressed at an early embryonic stage in the dorsal half of the neural tube. The expression pattern and nuclear localization were confirmed by immunohistochemical study. Furthermore, the bacterially expressed zic protein containing the zinc finger domains bound to the GLI-binding sequence. These findings suggest that zic is one of a number of nuclear factors involved in both differentiation in early development and maintenance of properties of the cerebellar granule cells.

Amino Acid Sequence↗
PubMed1994

Test of balanced transparency.

It is implicitly or explicitly assumed in current transparency models that all the parts of a completely transparent surface have the same perceived degree of transparency. In general, the two experiments reported here have shown that this assumption is false. Consequently, any general transparency equation based on this assumption is unjustified. Separate transparency equations for the different parts of a transparent surface are instead justified. This indicates the need for a model of the overall judgment of transparency of these parts. In the second experiment the hypothesis that the judged degree of transparency of a whole transparent surface is a weighted average of the judged degrees of transparency of the different parts of this surface was tested. The results contradict this hypothesis and support the idea that the judgment of transparency of a whole surface and that of its parts depend on different stimulus conditions.

Color Perception↗
PubMed1994

Uterine endometrial cavity movement and cervical mucus.

Uterine endometrial movements were observed by transvaginal ultrasound during mid- and late follicular phase and luteal phase in 273 cycles (180 spontaneous cycles in 72 patients; 75 clomiphene citrate cycles in 18 patients; 18 gonadotrophin cycles in 11 patients). The percentage of scans with endometrial movements was 74% in the mid-follicular phase, 96% in the late follicular phase and 72% in the luteal phase. Movements of endometrial cavity echo-free space were observed only in the late follicular phase when the cervical mucus was abundant. The direction of these endometrial cavity movements was objective and therefore distinct. The movements were either vertical (cervix-fundus) or horizontal at the fundus, often to and fro, not unidirectional. The endometrial cavity echo-free space content showed a fern-leaf pattern similar to that of cervical mucus. Thus the content might be cervical mucus plus endometrial secretion, and these fluids might be circulating, flushing or communicating via the cervical canal and the Fallopian tubes through these endometrial cavity movements.

Adult↗
PubMed1994

Characterization of glycophorin A transcripts: control by the common erythroid-specific promoter and alternative usage of different polyadenylation signals.

Glycophorins A (GPA) and B (GPB) are specifically expressed in human erythrocytes and express MN and Ss blood group antigens. While the GPB gene produces one transcript, the GPA gene produces three or four transcripts of different sizes. To understand the mechanisms of production of the different transcripts and erythroid-specific expression, we characterized the transcripts and the transcriptional regulatory regions of the glycophorin A gene. The transcriptional start site was determined by primer extension and S1 nuclease protection analysis, and it was found that all of the transcripts start at one major site. The nucleotide sequence of the newly isolated longest GPA cDNA revealed several polyadenylation signal sequences. To determine which polyadenylation signals are utilized, cDNA clones encoding GPA were isolated from a cDNA library of human erythroleukemia cell line K562 and the 3'-regions of the cDNAs were specifically amplified by the polymerase chain reaction. These results showed that five different polyadenylation signals of the GPA gene are utilized and the size and abundance of the transcripts are consistent with those detected by Northern blot analysis of K562 mRNAs. The 5'-flanking sequence was found to contain several binding motifs for the transcription factors, which were also found in other erythroid-specific genes. These motifs include the binding sites for the GATA-1 and NF-E2 erythroid-specific transcription factors, in addition to Sp1 transcription factor. The 5'-sequence from -750 to +36 relative to the transcriptional start site could confer only a low basal transcriptional activity in K562 cells and Friend erythroleukemia cells. This activity was significantly increased after Friend erythroleukemia cells were differentiated by dimethylsulfoxide. These results suggest that the 5' region regulates the glycophorin gene expression in erythroid-specific fashion.

Amino Acid Sequence↗
PubMed1994

Microfluorocytometric detection of nuclear DNA damage to cancer cells in squamous cell carcinoma after hyperthermia.

An 84-year-old woman had a squamous cell carcinoma on her left thigh. Before operation, half of the tumor mass was irradiated with a microwave at 43 degrees C for an hour. After the hyperthermia, the tumor mass was removed, and the DNA instability was investigated by microfluorocytometric measurement of the cells stained with pararosaniline-Feulgen after hydrolysis with 2N HCl at 30 degrees C. The kinetic parameters k1, which is the rate constant for the generation of an apurinic acid, k2, which is the rate constant for the depolymerization of the apurinic acid and which reflects the degree of DNA instability for acid hydrolysis, and y0, which is the theoretical value of the single-stranded DNA present initially and reflects the degree of DNA damage, were determined by a computer fitting of the Bateman function to the hydrolysis curve plotting of the fluorescence intensity of the pararosaniline-Feulgen staining the apurinic acid against the different hydrolysis times. The parameter values y0 and k2 of the cells treated by hyperthermia were much higher than those of the cells treated without hyperthermia. It is our conclusion that this microfluorometric detection would be valuable as an evaluation method for a cancer therapy, although more data from other cancers and treatments will be needed.

Aged↗
PubMed1994

The peritoneal equilibration test variables in pediatric CAPD patients.

The peritoneal equilibration test (PET) is generally accepted as a valuable tool in individualizing continuous ambulatory peritoneal dialysis (CAPD) treatment schedules in adults. However, the classification of peritoneal permeability as described by Twardowski is not available for children due to differences in peritoneal transport abilities. In this paper, we report the results of the PET for 20 patients aged from 1.5 to 24 years (mean 10.3 years), who started CAPD therapy at age 0-15 years, using Twardowski's standardized technique. D/P creatinine (dialysate to plasma ratio of creatinine at 4 h), D/D0 glucose (the ratio of dialysate glucose at 4 h dwell time to dialysate glucose at 0 dwell time), and the residual volume (RV) in the abdominal cavity were calculated. The mean and standard deviation values for D/P creatinine and D/D0 glucose were of a higher permeability level than those reported in Twardowski's data. Furthermore, a significant correlation of creatinine and glucose with fluid drainage ability of the peritoneum were observed. A large amount of RV (425 +/- 125 mL/m2) was detected in the patients' peritoneal cavity and this had a significant correlation with dialysate leak occurrences. The authors suggest that the RV would be an indicator for leaks and especially latent leaks. The cause of a large RV is unknown, but there is a probability that drainage volume and transport rates of metabolites decrease because the concentration of the instilled dialysate is immediately diluted by a large RV within the peritoneum.

Adolescent↗
PubMed1994

An outbreak of group B streptococcus infection in a neonatal nursery and subsequent trial for prophylaxis of nosocomial transmission.

An outbreak of sepsis and meningitis caused by group B streptococcus occurred in three very low birthweight infants. To prevent further nosocomial transmission, immune globulin and ampicillin sodium were administered intravenously to other very low birthweight infants. After this prophylaxis, no other infants were involved in this outbreak. Immuno- and chemoprophylaxis may be considered as procedures to prevent nosocomial infection for very low birthweight infants.

Ampicillin↗
PubMed1994

Multifactorial modeling for root caries prediction: 3-year follow-up results.

The study was part of a series aiming at the development of caries tests. The initial material (n = 104, age range 47-79 yr, mean 62 yr) was reduced to 96, who were observed for 3 yr. During the follow-up four subjects died, all due to myocardial infarction, and four refused to participate. Thorough oral examinations were conducted at the baseline, 1- and 3-yr registrations; coronal and root surface caries were registered separately according to WHO classification. The tests included salivary mutans streptococci, lactobacilli, candida/yeasts, secretion rate, buffer effect and sucrase activity, and quantitation of visible plaque. The association between prospective root caries increment and several tests was significant. Multifactorial modeling resulted in the combination of Past Root Caries Experience (OR 12.8), Lactobacilli (OR 8.6) and Candida (OR 2.8). At screening, the criterion "two or three positive tests" of these yielded acceptable accuracy (77.1) and a relative risk of 3.3.

Aged↗
PubMed1994

Cloning and sequencing of a 2,5-dichloro-2,5-cyclohexadiene-1,4-diol dehydrogenase gene involved in the degradation of gamma-hexachlorocyclohexane in Pseudomonas paucimobilis.

In Pseudomonas paucimobilis UT26, gamma-hexachlorocyclohexane (gamma-HCH) is converted to 2,5-dichloro-2,5-cyclohexadiene-1,4-diol (2,5-DDOL), which is then metabolized to 2,5-dichlorohydroquinone. Here, we isolated from the genomic library of UT26 two genes which expressed 2,5-DDOL dehydrogenase activity when they were transformed into P. putida and Escherichia coli. Both gene products had an apparent molecular size of 28 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The first gene, named linC, located separately from the two genes (linA and linB) which we had already cloned as genes involved in the gamma-HCH degradation. The other, named linX, located about 1 kb upstream of the linA gene encoding gamma-HCH dehydrochlorinase. A gamma-HCH degradation-negative mutant, named UT72, which lacked the whole linC gene but had the intact linX gene was isolated. The linC gene given in a plasmid could complement UT72. These results strongly suggest that the linC gene but not the linX gene is essential for the assimilation of gamma-HCH in UT26. Deduced amino acid sequences of LinC and LinX show homology to those of members of the short-chain alcohol dehydrogenase family.

Alcohol Oxidoreductases↗
PubMed1994

Nucleotide sequence and functional analysis of the meta-cleavage pathway involved in biphenyl and polychlorinated biphenyl degradation in Pseudomonas sp. strain KKS102.

Pseudomonas sp. strain KKS102 is able to degrade biphenyl and polychlorinated biphenyls via the meta-cleavage pathway. We sequenced the upstream region of the bphA1A2A3BCD (open reading frame 1 [ORF1]) A4 and found four ORFs in this region. As the deduced amino acid sequences of the first, second, and third ORFs are homologous to the meta-cleavage enzymes from Pseudomonas sp. strain CF600 (V. Shingler, J. Powlowski, and U. Marklund, J. Bacteriol. 174:711-724, 1992), these ORFs have been named bphE, bphG, and bphF, respectively. The fourth ORF (ORF4) showed homology with ORF3 from Pseudomonas pseudoalcaligenes KF707 (K. Taira, J. Hirose, S. Hayashida, and K. Furukawa, J. Biol. Chem. 267:4844-4853, 1992), whose function is unknown. The functions of meta-cleavage enzymes (BphE, BphG, and BphF) were analyzed by using crude extracts of Escherichia coli which expressed the encoding genes. The results showed that bphE, bphG, and bphF encode 2-hydroxypenta-2,4-dienoate hydratase, acetaldehyde dehydrogenase (acylating), and 4-hydroxy-2-oxovalerate aldolase, respectively. The biphenyl and polychlorinated biphenyl degradation pathway of KKS102 is encoded by 12 genes in the order bphEGF (ORF4)A1A2A3BCD (ORF1)A4. The functions of ORF1 and ORF4 are unknown. The features of this bph gene cluster are discussed.

Aldehyde Oxidoreductases↗
PubMed1994

Identification of the bphA4 gene encoding ferredoxin reductase involved in biphenyl and polychlorinated biphenyl degradation in Pseudomonas sp. strain KKS102.

The nucleotide sequence of the downstream region of the bph operon from Pseudomonas sp. strain KKS102 was determined. Two open reading frames (ORF1 and ORF2) were found in this region, and the deduced amino acid sequence of ORF2 showed homology with the sequences of four ferredoxin reductases of dioxygenase systems. When this region was inserted just upstream of the bph operon, which does not contain a gene encoding ferredoxin reductase, biphenyl dioxygenase activity was detected. The 24- and 44-kDa polypeptides predicted from the two open reading frames were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Crude extract which contained the products of ORF2 and bphA1A2A3 showed cytochrome c reduction activity. These data clearly suggest that ORF2 encodes ferredoxin reductase. The deduced amino acid sequence of ORF1 does not show significant homology with the sequences of any other proteins in the SWISS-PROT data bank, and the function of ORF1 is unknown.

Amino Acid Sequence↗
PubMed1994

Different iris coloration and uptake of a fluoroquinolone agent into the iris ciliary body of rabbit eyes.

In order to know the correlation of a drug with high affinity to melanin in the iris ciliary body with the amount of melanin contained in the iris ciliary tissues, an in vivo study was performed on pigmented rabbits with brown or blue irises and albino rabbits. The melanin concentrations in the iris ciliary bodies of pigmented rabbits with brown and blue irises and nonpigmented rabbit eyes with whitish irises were determined. The mean concentrations of melanin in the eyes with brown-, blue- and whitish-colored irises were 47.43, 34.73 and below 0.2 microgram/mg tissue, respectively. The amount of sparfloxacin uptake in the iris ciliary bodies of eyes with brown, blue and whitish irises administered as 40 microliters of 0.3% solution 5 times every 5 min was 15.46 +/- 2.07, 8.53 +/- 1.87 and 1.9 micrograms/g, respectively. The results may be useful for intraocular drug dynamics studies.

Administration, Topical↗
PubMed1994

Correlation of serum interleukin-8 and cell surface lysosome-associated membrane protein expression with clinical disease activity in systemic lupus erythematosus.

Cell surface expression of lysosome-associated membrane proteins (LAMPs) correlates with serum interleukin-8 (IL-8) levels, shorter disease duration, greater functional impairment from disease-related symptoms and soluble IL-2 receptor levels (sIL-2R) in patients with scleroderma. In this study of 46 patients with systemic lupus erythematosus (SLE), the relationship of serum IL-8 and cell surface LAMP to two clinical measures of disease activity, the SLEDAI and SLAM scales, was evaluated. IL-8 levels were determined on serum samples by the immunometric sandwich enzyme immunoassay technique. Cell surface LAMP expression was determined by flow cytometric quantitation of peripheral blood mononuclear cells with monoclonal antibodies directed against two of the major LAMP proteins, lamp1 and lamp2. The clinical disease activity scales correlated significantly with each other, with C3 levels, serum IL-8, C4, dsDNA and sIL-2R. Lamp1 and lamp2 expression correlated with the SLAM but not the SLEDAI scale. Serum IL-8 levels were elevated in 49 of 51 samples tested (44 of 46 patients) and had a stronger correlation with disease activity than C4, dsDNA and sIL-2R levels. Significantly higher levels of IL-8 were seen in patients with evidence of renal involvement. Serum IL-8 and cell surface LAMP expression may be useful indicators of disease activity in patients with SLE. The possible role of IL-8 in the pathogenesis of SLE requires further investigation.

Adolescent↗
PubMed1994

The ACE inhibitor alacepril suppresses atherogenesis independent of serum lipids in cholesterol-fed rabbits--critical analysis with new ultrasound technique.

The effects of alacepril, an angiotensin converting enzyme inhibitor, on atherogenesis were examined in rabbits fed a hypercholesterol diet. The process of atherogenesis was evaluated in vitro by high-resolution transesophageal ultrasonography (TEE phi 4 mm, 7.5 MHz), by direct histological examination and by serum lipid examination. Of the 38 subjects, 18 were designated as the control hypercholesterol group (CH) and 20 received oral alacepril at 90 mg/day (ACE) for 13-22 weeks. Three rabbits in each group died due to pneumonia. TEE enabled a clear diagnosis as either normal, early stage or late stage of atherosclerosis. The intimal-medial thickness was significantly less in the ACE group than in the CH group, but only over the middle portion of the aorta. The ACE group had a smaller area of atheromatous plaque than the CH group (atheromatous index: 37 +/- 20* and 60 +/- 30% respectively, *p < 0.02). Serum cholesterol and triglycerides were similar in the CH group (1590 +/- 653, 258 +/- 224) and the ACE group (1574 +/- 824, 303 +/- 360 respectively). In conclusion, alacepril reduced both the area of atheromatous atheroma plaque and wall hypertrophy independent of serum lipids in cholesterol-fed rabbits. In vitro miniature TEE is a dependable method for evaluating atherosclerosis in rabbits with hypercholesterolemia.

Angiotensin-Converting Enzyme Inhibitors↗