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Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 613 records · Page 34Linked to original sources
PubMed1991

Disjunctive eye movement evoked by microstimulation in an extrastriate cortical area of the cat.

Slow disjunctive eye movement similar to ocular convergence was evoked by microstimulation in parts of the lateral suprasylvian area (LSA) in alert cats. A tungsten-in-glass microelectrode was used for stimulation, and eye movement was monitored using the magnetic search coil method. The velocity-versus-amplitude relationship of disjunctive eye movement evoked by microstimulation was comparable to that of ocular convergence evoked by presenting a visual target. It is suggested that the LSA plays a role in controlling convergence eye movement.

Animals↗
PubMed1991

Production, characterization and protective effect of monoclonal antibodies to Haemophilus paragallinarum serotype A.

Monoclonal antibodies (mAbs) to Haemophilus paragallinarum serotype A were obtained by fusion of murine myeloma cells (P3-X63-Ag8-U1) and spleen cells from BALB/c mice immunized with whole cells of strain 221. Enzyme linked immunosorbent assay with whole cells was used to show that the monoclonal antibodies are specific for serotype A of H. paragallinarum. Four monoclonal antibodies indicated hemagglutination-inhibition (HAI) activity against serotype A; their titers were 10(4)-10(5). By western blotting, two of these monoclonal antibodies reacted with a protein of molecular weight 39,000. Chickens treated with mAbs possessing HAI activity survived without clinical signs of infection. No challenge strain was isolated from these chickens, indicating that four mAbs with HAI activity suppressed growth of the challenge strain in the nasal cavity, whereas mAbs without HAI activity showed no passive protective effect. These results demonstrated that HI antibodies contributed to protection, and strongly suggest that hemagglutinin (HA) antigen, especially the epitopes which were recognized by these mAbs are important for protective immunity in chickens.

Animals↗
PubMed1991

CYP52 (cytochrome P450alk) multigene family in Candida maltosa: molecular cloning and nucleotide sequence of the two tandemly arranged genes.

Southern blot analysis under low-stringency conditions using a previously isolated n-alkane-inducible cytochrome P450 (P450alk) gene as a probe revealed the presence of multiple P450alk-related genes in the genome of Candida maltosa. Nine P450alk-related genes (one reported previously and eight in the present report) were isolated from a genomic library constructed from this strain, and these were classified on the basis of sequence similarities into three pairs of putative allelic genes and three nonallelic genes. Two pairs of these alleles were tandemly arranged in the genome. The complete nucleotide sequences of one of these pairs were determined and compared to other members of this P450 family (CYP52) in C. maltosa and C. tropicalis. Northern blot analysis further showed that these genes were regulated by carbon sources. These results provide evidence for a P450alk (CYP52) multigene family in C. maltosa.

Amino Acid Sequence↗
PubMed1991

Monitoring Culex tritaeniorhynchus (Diptera: Culicidae) abundance in cow sheds by in situ counting.

The number of Culex tritaeniorhynchus Giles counted in situ on five sheets of paper was compared with that of mosquitoes captured in a Nozawa blacklight trap at two cow sheds in Tsu City, Japan, to evaluate the effectiveness of the in situ counting method. The total number of Cx. tritaeniorhynchus collected on 27 lighttrap-nights (434,362) was greater than that counted in situ on 270 paper samples (18,093). A highly significant temporal correlation (Kendall's tau = 0.54) was shown between the numbers of Cx. tritaeniorhynchus collected per light trap night and per paper sample.

Animals↗
PubMed1991

Expression of RNase Rh from Rhizopus niveus in yeast and characterization of the secreted proteins.

The full-length cDNA encoding RNase Rh, which is secreted extracellularly by Rhizopus niveus, was isolated and its nucleotide sequence was determined. It was placed under control of the promoter of the glyceraldehyde 3-phosphate dehydrogenase gene of Saccharomyces cerevisiae in a high expression vector in yeast. Since yeast cells transformed by this plasmid poorly secreted RNase into the medium, the plasmid pYE RNAP-Rh was constructed, in which the signal sequence of RNase Rh was replaced by the prepro-sequence of aspartic proteinase-I, one of the extracellular enzymes secreted by R. niveus. Yeast cells harboring pYE RNAP-Rh produced RNase efficiently (ca. 40 micrograms/ml) into the medium. The product was a mixture of six enzymes (RNase RNAP-Rhs) having 3, 5, 9, 13, 14, and 16 additional amino acid residues attached to the amino terminus of the mature RNase Rh. The major product was the RNase with three additional amino acids at the amino terminus. Limited digestion of RNase RNAP-Rhs with staphylococcal V8 protease succeeded in shortening the various lengths of extra amino acid residues attached to the amino terminus of RNase Rh, yielding an RNase that has 3 additional amino acids at the amino terminus. It has been named RNase RNAP-Rh. The RNase RNAP-Rh showed the same specific activity and CD spectra as those of RNase Rh, suggesting that the two have similar conformations to each other around aromatic amino acid residues and the peptide backbone.

Amino Acid Sequence↗
PubMed1991

Protective effects of monoclonal antibodies against lethal canine distemper virus infection in mice.

Monoclonal antibodies (MAbs) against the haemagglutinin (H), fusion protein (F) and nucleoprotein of canine distemper virus (CDV) were examined for their ability to protect mice against lethal CDV infection. One MAb against H and two of six MAbs against F protected mice, the protective effect of the anti-H MAb being stronger than that of the anti-F MAbs. The anti-H MAb showed virus neutralizing activity, but the two anti-F MAbs, which recognized the same epitope, did not. Protection by the anti-F MAbs correlated with cell fusion inhibition, but not with complement-dependent neutralization, complement-dependent cytolysis or antibody-dependent cell-mediated cytotoxicity. These results suggest that neutralization by antibody against H and cell fusion inhibition by antibody against F play important roles in the protective mechanism against CDV infection.

Animals↗
PubMed1991

Molecular cloning of a Pseudomonas paucimobilis gene encoding a 17-kilodalton polypeptide that eliminates HCl molecules from gamma-hexachlorocyclohexane.

Pseudomonas paucimobilis UT26 is capable of growing on gamma-hexachlorocyclohexane (gamma-HCH). A genomic library of P. paucimobilis UT26 was constructed in Pseudomonas putida by using the broad-host-range cosmid vector pKS13. After 2,300 clones were screened by gas chromatography, 3 clones showing gamma-HCH degradation were detected. A 5-kb fragment from one of the cosmid clones was subcloned into pUC118, and subsequent deletion and gas chromatography-mass spectrometry analyses revealed that a fragment of ca. 500 bp was responsible for the conversion of gamma-HCH to 1,2,4-trichlorobenzene via gamma-pentachlorocyclohexene. Nucleotide sequence analysis revealed an open reading frame (linA) of 465 bp within the fragment. The nucleotide sequence of the linA gene and the deduced amino acid sequence showed no similarity to any known sequences. The product of the linA gene was 16.5 kDa according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Amino Acid Sequence↗
PubMed1991

Adult-form galactosialidosis: ocular findings in three cases.

We reported ocular findings of 3 patients with adult-form galactosialidosis. Diffuse fine opacities in the deep layer of the corneal stroma, an obscure cherry-red spot of the macula and optic nerve atrophy were noted in all cases. Punctate lenticular opacities were observed in 2 cases. Slowly progressive visual disturbance was seen in all cases, and it might be due to secondary optic nerve atrophy caused by retinal ganglion cell death.

Adult↗
PubMed1991

Biochemical and immunocytochemical characterization of mineral binding proteoglycans in rat bone.

We examined biochemically and immunocytochemically the type and distribution of mineral binding proteoglycans (PGs) in rat mid-shaft subperiosteal bone using three monoclonal antibodies (MAb 1-B-5, 9-A-2, and 3-B-3) which specifically recognize unsulfated chondroitin, chondroitin 4-sulfate (C4-S) and dermatan sulfate (DS), and chondroitin 6-sulfate. Bone proteins were extracted from fresh specimens with a three-step technique: 4 M guanidine HCl (GdnCl), aqueous EDTA without GdnCl (E-extract), followed by GdnCl. Western blot analysis of SDS-polyacrylamide gel electrophoresis revealed that E-extract after chondroitinase ABC digestion reacted strongly with MAb 9-A-2 but not with MAb 1-B-5 or 3-B-3. After adehyde fixation, ethanolic trimethylammonium EDTA was used as a demineralizing agent for light and electron immunocytochemistry. This provided good retention of water-soluble PGs in the specimens. After chondroitinase ABC pre-treatment of tissue sections, MAb 9-A-2 specifically stained C4-S and/or DS in the walls of osteocyte lacunae and bone canaliculi in the mineralized matrix as well as in the unmineralized matrix such as pre-bone, vascular canals, and pericellular matrix surrounding osteocytes; the remainder of the mineralized matrix lacked staining. These results indicate that mineral binding PGs contain C4-S and/or DS and are exclusively localized in the walls of the bone lacuna and canaliculus.

Animals↗
PubMed1991

Survey of infectious coryza of chickens in Indonesia.

A survey of infectious coryza of chickens was performed in West Jawa of Indonesia between 1987 to 1988 by the detection of hemagglutination-inhibition (HI) antibody against Haemophilus paragallinarum (Hpg) in non-vaccinated healthy laying (12 farms, 196 chickens) and native (8 farms, 197 chickens) chickens. HI antibodies against Hpg were detected not only in the native chickens but also in the laying chickens, regardless of the district, and were observed in 70% (14/20) of farms and 19% (73/393) of chickens. HI antibodies against serotype A were detected from 11 farms (55%) and 11% (45/393) in chickens. Those against serotype C were detected from 5 farms (25%) and 8% (30/393) in chickens. Three Hpg strains were isolated from different chickens affected with infectious coryza. Two of them were identified as type A and the other as type C by the rapid plate agglutination test. These results demonstrated that the outbreaks of infectious coryza caused by serotype A and C strains had occurred in Indonesia.

Animals↗
PubMed1991

Expression of hemagglutinin of Haemophilus paragallinarum serotype A in Escherichia coli.

The genomic DNA of Haemophilus paragallinarum (Hpg) serotype A strain 221 was cloned into vector plasmid pBR322. The recombinant plasmids were introduced into Escherichia coli (E. coli) strain C600. Subsequently, a total of 277 transformants were obtained. One, designated strain no. 6, expressed hemagglutination activity against chicken erythrocytes. Strain no. 6 contained the recombinant plasmid pNV102, and DNA of about 2.57 kb was inserted into pNV102. When strain no. 6 was cured of pNV102, the strain lost hemagglutination activity. When the cured strain was retransformed with pNV102, hemagglutination activity was restored. E. coli strain no. 6 reacted with monoclonal antibody specific to the hemagglutinin of Hpg serotype A in a dot-blotting analysis. Chickens immunized with the inactivated strain no. 6 produced the hemagglutination inhibition (HI) antibody, and chickens possessing the HI antibody showed protection against challenge exposure by Hpg strain 221.

Animals↗
PubMed1991

Influence of extracellular matrix on the proliferation and differentiation of glioma cells in culture.

The influence of extracellular matrix on the proliferation and differentiation of glioma cells in vitro was investigated by culturing glioma cells in collagen gel and on collagen and laminin films. Rat C-6 glioma cells extended thin cytoplasmic processes, proliferated, and differentiated in collagen gel and on collagen film. The cells were stellate with multiple thin processes like the astrocyte in vivo. The intracellular content of cyclic adenosine-monophosphate in rat C-6 glioma cells on collagen film increased approximately four fold over the control level. In laminin film culture, rat C-6 glioma cells extended thin cytoplasmic processes with many knotty structures and proliferated. These findings confirm that extracellular matrix induces the differentiation of glioma cells.

Animals↗
PubMed1991

Nucleolar organizer regions in various human brain tumors.

Nucleolar organizer regions (NOR's) are loops of deoxyribonucleic acid (DNA) which transcribe to ribosomal ribonucleic acid (RNA) by RNA polymerase I. They possess vital significance in the ultimate synthesis of cellular proteins. A silver colloid staining technique for demonstration of NOR-associated proteins (Ag-NOR's) was applied to paraffin-embedded sections from 128 varied brain tumors and to chromosomal preparations from cultured brain-tumor cells. There was a statistically significant difference in the mean number of Ag-NOR's per nucleus between low-grade tumors (1.98/nucleus) and high-grade tumors (2.95/nucleus). It is suggested that the mean number of Ag-NOR's may represent the proliferative potential of brain tumors. Furthermore, high-grade tumors usually showed relatively large Ag-NOR's in a scattered distribution. In chromosomal preparations, the cultured cells displayed five to 12 Ag-NOR's on acrocentric chromosomes. Five of eight cell lines examined demonstrated ectopic Ag-NOR's. This simple staining technique can be easily applied to routinely processed paraffin-embedded sections and will become a useful tool for quick estimation of the proliferative potential of human brain tumors.

Adenoma↗
PubMed1991

Isolation and sequencing of a gene, C-ADE1, and its use for a host-vector system in Candida maltosa with two genetic markers.

The host-vector systems of an n-alkane-assimilating-yeast, Candida maltosa, that we previously constructed consisted of a vector replicating with an ARS region of this yeast, and C. maltosa strains J288 (leu2) or CH1 (his5) as hosts. Since each of these hosts has a single genetic marker, we have developed a new host-vector system using two genetic markers. By UV irradiation of strain CH1, an adenine auxotrophic mutant, CHA1, forming red colonies was isolated. A DNA fragment complementing this deficiency was isolated from the C. maltosa genome. Since the DNA fragment also complemented the ade1 mutation of S. cerevisiae, we termed a gene contained in this DNA fragment C-ADE1. The nucleotides of C-ADE1 were sequenced. The deduced amino acid sequence (291 residues) had 65.6% homology with that of ADE1 of S. cerevisiae (306 residues). Having the cloned C-ADE1 DNA, we improved the host-vector system of C. maltosa.

Adenine↗
PubMed1991

Evidence that more than one gene encodes n-alkane-inducible cytochrome P-450s in Candida maltosa, found by two-step gene disruption.

An n-alkane-assimilating yeast, Candida maltosa, has a diploid genome. Probed with the previously isolated gene of n-alkane-inducible cytochrome P-450 (P-450alk), its allelic gene had been isolated, its nucleotides sequenced, and the interallelic divergence examined. Using one of the allelic genes, we disrupted the two alleles of the cytochrome P-450alk gene by a two-step gene disruption system. Surprisingly, the disruptant still assimilated n-alkane and contained n-alkane-inducible cytochrome P-450. This result indicates that, other than the disrupted two alleles, there is at least one other gene that encodes an n-alkane-inducible cytochrome P-450.

Alkanes↗
PubMed1991

[Laboratory and clinical studies of cefdinir 5% and 10% fine granules in pediatric field].

We have carried out laboratory and clinical studies on cefdinir (CFDN) 5% and 10% fine granule preparations. The results are summarized as follows. CFDN 5% fine granule preparation was given via oral route to each of 2 children in the fasting state at a single dose of 3 mg/kg. After administration, the mean peak plasma level of CFDN was 0.76 micrograms/ml at 4 hours and the mean half-life was 1.77 hours. The mean urinary excretion rate of CFDN was 31.5% in the first 12 hours after oral administration. CFDN 10% fine granule preparation and CFDN 100 mg capsule were given via oral route 3 children and to another child in the fasting state at single doses of 3 mg/kg and 2.63 mg/kg, respectively. After administration of 10% granules the mean peak plasma level of CFDN was 0.73 micrograms/ml at 2 hours and the mean half-life was 1.62 hours. The peak serum level obtained after administration of CFDN 100 mg capsule was 0.91 micrograms/ml at 2 hours and the half-life was 1.08 hours. The mean urinary excretion rate obtained with CFDN 10% fine granules was 26.2% in the first 8 hours after oral administration and the urinary excretion rate obtained with CFDN 100 mg capsule was 19.7% in the first 12 hours after oral administration. Treatment with CFDN 5% fine granules was made for a total of 48 cases of pediatric bacterial infections including 21 cases of tonsillitis, 12 cases of scarlet fever, 3 cases of pharyngitis, 5 cases of impetigo, 1 case of subcutaneous abscess, 1 case of furuncle, 5 cases of UTI. Results obtained were excellent in 30 cases, good in 18 cases. Treatment with CFDN 10% fine granules was made for a total of 16 cases of pediatric bacterial infections including 6 cases of tonsillitis, 3 cases of pneumonia, 4 cases of scarlet fever, 2 cases of impetigo, 1 case of UTI. Results obtained were excellent in 8 cases, good in 7 cases, poor in 1 case. No significant side effects due to the drugs were observed except 2 cases (1 case with 5% preparation and another with 10%) with eosinophilia, 3 cases (all with 5%) with diarrhea and 1 case each of elevated GOT & GPT (with 5%) and elevated GOT, GPT & Al-P (with 10%).

Administration, Oral↗
PubMed1991

New restoration and direct pulp capping systems using adhesive composite resin.

There have been many arguments on the irritating mechanisms of the composite resin on the dental pulp. While the direct irritative effect of the resin has been preferred, some authors considered that the marginal microleakage and the resulting bacterial infection play a more important role in inducing the complicating pulp irritation. We developed a new filling technique, called the direct inlay restoration method, which could prevent the marginal leakage associated with the polymerization shrinkage of the adhesive composite resin. In this study, we tried to apply our method clinically. None of the 440 cases which were filled with the adhesive composite resin and 60 cases out of 64 cases in which the pulps were directly capped with the adhesive composite resin developed any signs and symptoms of pulp irritation. The other 4 cases developed signs of pulp irritation. Two of those 4 cases were pulpectomized due to spontaneous pain and the other 2 cases turned out to be well after re-restoration. With the informed consent of the patients, the direct pulp capping using the adhesive composite resin was experimentally performed on 6 caries-free 3rd molars and the histopathological examination of these capped molars revealed that neither significant degenerative nor inflammatory changes were brought about in the dental pulp. These clinical and histopathological observation suggest that the dental pulp irritation after resin filling is not induced by the composite resin itself.

Adolescent↗