Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 397 records · Page 22Linked to original sources

PubMed1996

Detection of visual dysfunction in optic atrophy by functional magnetic resonance imaging during monocular visual stimulation.

PURPOSE: To evaluate functional magnetic resonance imaging as an objective method for detecting visual dysfunction in various ophthalmologic disorders involving the optic nerve and the chiasm. METHODS: We performed functional magnetic resonance imaging during monocular visual stimulation on seven patients with visual field loss caused by lesions of the optic nerve and the chiasm and on three normal control subjects with no visual field loss. We correlated static threshold perimetry in the seven patients with the results of functional magnetic resonance imaging. RESULTS: In the three normal control subjects, we found good intrasubject similarity in areas of bilateral occipital lobe activation between monocular stimulation of the right and left eyes. In the patients with unilateral optic neuropathy, including glaucoma, stimulation of the affected eye induced no activation of the primary visual cortex in the portion corresponding to the central visual field defects and reduced activity of the associated visual cortex. In the patients with chiasmal compression, monocular stimulation resulted in a marked asymmetry of activation in the primary visual cortex, which corresponded to the visual field abnormality. CONCLUSIONS: Functional magnetic resonance imaging appears to be useful in confirming the clinical diagnosis of optic atrophy because it can objectively disclose visual field loss, even a small defect such as central scotoma.

Adult↗

PubMed1996

Roles of the lateral suprasylvian cortex in convergence eye movement in cats.

Ocular convergence and lens accomodation were evoked by microstimulation in the lateral suprasylvian area (LS cortex) in the parieto-occipital cortex in the cat. Electrolytic lesions in LS cortex reduced the amplitude and velocity of ocular convergence. Neurons in LS cortex discharged in relation to ocular convergence and/or lens accommodation. These results support the hypothesis that the LS cortex plays an important role in controlling ocular convergence The LS cortex receives visual inputs from cortical visual areas 17, 18 and 19, and in addition from the superior colliculus through the LP nucleus of the thalamus. Electrophysiological recordings have revealed that these visual inputs, which include cues about 3-dimensional target motion, are integrated in the LS cortex. The integrated output from LS cortex may provide the brainstem motor centers with the neural signals that facilitate eye movements, especially when the target is moving at high speeds. Outputs from the LS cortex travel directly to brainstem structures including the superior colliculus and pretectum. Evidence from monkey suggests that information may also travel to the mesencephalic reticular formation, where neurons have been recorded that are related to ocular convergence, lens accomodation or both. Although comparable data is lacking in the cat, it is suggested that the efferent circuit from the LS cortex to the motor nuclei in the brainstem included both the superior colliculus and the mesencephalic reticular formation. It is also suggested that this pathway is rather short, given that the mean latency of the early component of evoked disjunctive eye movements was approximately 60 ms.

Animals↗

PubMed1996

Defective B-1 cell development and impaired immunity against Angiostrongylus cantonensis in IL-5R alpha-deficient mice.

We generated interleukin-5 receptor alpha chain (IL-5R alpha)-deficient (IL-5R alpha-/-) mice by gene targeting. The IL-5R alpha-/- mice showed decreased numbers of B-1 cells concomitant with low serum concentrations of IgM and IgG3. They showed no IL-5-induced enhancement of B cell responses to T-independent antigens. The number of alpha beta T cell receptor-positive thymocytes tended to decrease in 3-week-old IL-5R alpha-/- mice, returning to normal by 6 weeks of age. The IL-5R alpha-/- mice produced basal levels of eosinophils, while their bone marrow cells failed to form eosinophilic colonies in response to IL-5. Impaired eosinophilopoiesis in IL-5R alpha-/-mice enhanced the survival of Angiostrongylus cantonensis. These results indicate that IL-5-induced eosinophils serve as potent effector cells in the killing of Angiostrongylus cantonensis in mice.

Angiostrongylus cantonensis↗

PubMed1996

Survival of newly emerged Culex tritaeniorhynchus (Diptera:Culicidae) adults in field cages with or without predators.

A field experiment was conducted to estimate the survival of Culex tritaeniorhynchus Giles adults before 1st blood feeding under conditions with or without predators in a rice field in central Japan. Adults were counted for 5 d after emerging in cages (2 by 2 and 1.5 m high), which were placed in rice fields during the midseason drying period. Only 10% of the adults survived until day 4 after emergence when exposed to predation, whereas > 60% of the adults survived until day 4 without predation. Lycosidae, hunting spiders, may be an effective predator of Cx. tritaeniorhynchus adults.

Animals↗

PubMed1996

Molecular cloning and characterization of human non-smooth muscle calponin.

cDNA clones encoding a calponin isoform with 309 amino acids have been isolated from human heart. The deduced amino acid polypeptide (M(r) 33,697) showed a neutral isoelectric point of 7.1. The mRNA, expressed in cultured smooth muscle cells as well as in fibroblasts, vascular endothelial cells, and keratinocytes, contains a 3' untranslated region of 1.2 kilobases that includes an Alu repetitive sequence in the antisense direction. On the basis of the nucleotide sequence identity to an expressed sequence tag, HUM21ES93 [Cheng, J.-F., Boyartchuk, V., and Zhu, Y. (1994) Genomics 23, 75-84], the human neutral calponin gene is assigned to chromosome 21q11.1. The amino acid sequence indicates that this protein is the human equivalent of mouse calponin-h2 (94.8% identity) [Strasser, P., Gimona, M., Moessler, H., Herzog, M., and Small, J.V. (1993) FEBS Lett. 330, 13-18]. Three tandem repeats of 29 amino acids, a Vav-homologous region and an actin-binding sequence, originally identified in the basic calponin isoform, are conserved. There are two consensus phosphorylation sites for tyrosine kinase. An immunoreactive form of the neutral calponin appears to be localized with vinculin in the cell-to-cell junctions of cardiomyocytes. Mouse calponin-h2 is also expressed in both embryonic and adult heart. These results indicate that the human neutral calponin is a non-smooth muscle isoform, and may play a physiological role in cytoskeletal organization.

Adult↗

PubMed1996

Isolation and characterization of ECT1 gene encoding CTP: phosphoethanolamine cytidylyltransferase of Saccharomyces cerevisiae.

Saccharomyces cerevisiae mutants that were unable to utilize extracellular ethanolamine for phosphatidylethanolamine synthesis were isolated. Two of them carried recessive chromosomal mutations in a same gene and were defective in CTP:phosphoethanolamine cytidylyltransferase (ECT) activity in vitro (Ect-). In an Ect- mutant that also carried the cho1 mutation, phosphatidylethanolamine accounted for less than 2% of total phospholipids, suggesting the importance of ECT in phosphatidylethanolamine synthesis. By screening a genomic library on a low copy number vector, three complementary clones of different size were isolated. A 2.8-kb common DNA region carried an open reading frame (ORF) of 969 bp in length, of which a truncated from failed to complement the Ect- mutation. This ORF was identical to the previously isolated MUQ1 gene of unknown function. Its deduced amino acid sequence had significant similarity to CTP: phosphocholine cytidylyl-transferases of yeast and rat. The entire ORF, when combined with the glutathione S-transferase gene and expressed in Escherichia coli, exhibited ECT activity. These results indicate that the cloned gene encodes a catalytic subunit of ECT of S. cerevisiae.

Amino Acid Sequence↗

PubMed1996

Construction of a dimeric DNA-binding peptide model by peptide-anthraquinone conjugation.

A peptide-anthraquinone conjugate was designed and synthesized containing linked peptide chains composed of Asp-Pro-Ala-Ala-Leu-Lys-Arg-Ala-Arg-Asn-Thr-Glu-Ala- Ala-Arg-Arg-Ser-Arg-Ala-Arg-Lys-Leu-Gln-Arg-Met, representing the basic region of GCN4. The two peptides were joined with anthraquinone at its 1- and 8-positions in a two-fold symmetric fashion, mimicking dimeric DNA-binding proteins. Experimental data indicated both an interaction of the anthraquinone moiety with the DNA double strand and an increase in the alpha-helicity of the peptide moieties of the ligand when it binds to DNA.

Amino Acid Sequence↗

PubMed1996

[Diagnosis and clinical manifestations of diarrheal virus infections in Maizuru area from 1991 to 1994--especially focused on small round structured viruses].

Rotavirus (44.7%), adenovirus (5.6%), small round structured viruses such as astrovirus (9.8%) and Norwalk like virus (6.9%) were detected by latex agglutination and reverse transcription polymerase chain reaction amplification from 378 stool samples in an outpatient clinic of Pediatrics in Maizuru area from 1991 to 1994. 70.0% were found from 6 months to 2 years old and 91.0% were detected from January to April. Serotype 1 astrovirus and group 2 Norwalk like virus were mainly found in all serotypes in each virus. Diarrhea, vomiting, nausea, fever, cough and rhinorrhea, and severity of diseases were examined in each case. Fever is significantly found in patients with rotavirus. Sporadic cases with small round structured viruses were recognized in the outpatient clinic of pediatrics.

Adenoviridae↗

PubMed1996

Inhibitory effect of cephalothin on matrix metalloproteinase activity around loose hip prostheses.

The inhibitory effects of drugs on matrix metalloproteinase (MMP) activity in tissues around sites of loose total hip arthroplasty (THA) prostheses were studied. For activity measurements, a DNP-S (dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg) peptide degradation assay was performed by means of high-performance liquid chromatography. Neutral salt tissue extracts revealed significantly elevated MMP activity in THA samples compared with that in noninflamed synovial tissue from the knee joint. This elevation was markedly inhibited by cephalothin, but not by doxycycline, tetracycline, or gentamicin. These results indicate that cephalothin can inhibit MMP activity in reactive periprosthetic tissue and thus reduce, by a nonantimicrobial mechanism, the tissue destruction associated with the loosening of THA implants.

Adult↗

PubMed1996

Cyclization reaction catalyzed by branching enzyme.

The action of branching enzyme (EC 2.4.l.l8) from Bacillus stearothermophilus on amylose was analyzed. The enzyme reduced the molecular size of amylose without increasing the reducing power. This result could not be explained by the normal branching reaction model. When the product was treated with glucoamylase (an exo++-type amylase), a resistant component remained. The glucoamylase-resistant component was easily digested by an endo-type alpha-amylase or by isoamylase plus glucoamylase. These results suggested that the glucoamylase-resistant component was a cyclic glucan composed of alpha-1,4- and alpha-l,6-glucosidic linkages. In other words, it was suggested that branching enzyme catalyzed cyclization of the alpha-l,4-glucan chain of the amylose molecule to form an alpha-l,6-glucosidic linkage, thereby forming two smaller molecules. Mass spectrometry also supported the cyclic nature of the product.

1,4-alpha-Glucan Branching Enzyme↗

PubMed1996

Coronary angiographic finding of thrombus in the left atrial appendage.

PURPOSE: The value of coronary angiography in the diagnosis of thrombus in the left atrial appendage (LAA) was retrospectively analyzed. MATERIAL AND METHODS: The study covers 34 patients in whom coronary angiography showed coronary neovascularity in LAA with coronary artery-left atrial fistula indicating LAA thrombus. All 34 patients underwent transthoracic echocardiography within one week of coronary angiography. Open-heart surgery was undertaken 2-31 months after angiography in 28 patients. RESULTS: Coronary neovascularity and coronary artery-left atrial fistula arose from the left circumflex artery in 28 patients, and from the left circumflex artery and the right coronary artery in the remaining 6 patients. By echocardiography, LAA thrombus was detected in only one of the 34 patients. In 18 of the 28 patients who underwent open-heart surgery, LAA thrombus was found at surgery to have resolved. CONCLUSION: Coronary angiography is useful in the diagnosis of LAA thrombus, and coronary neovascularity and fistula formation may indicate that the thrombus can spontaneously resolve.

Adult↗

PubMed1996

Cloning and characterization of the Rhizopus niveus leu1 gene and its use for homologous transformation.

The Rhizopus niveus leul gene was cloned using a 2-kb HindIII fragment of the leuA gene of Mucor circinelloides as a hybridization probe. The coding region of this gene comprises 1890 bp that encode a putative protein of 630 amino acids. The predicted amino acid sequence is similar to those of other alpha-isopropylmalate isomerases (alpha-IPMIs), showing 79.4%, 71.7%, and 60.6% identity with the Mucor circinelloides LeuA, Phycomyces blaskesleeanus Leu1, and Ustilago maydis Leu1, respectively. The vector pRN1, which contains a 3.7-kb BamHI-SacI fragment of the R. niveus leul gene, could complement leucine auxotrophy of R. niveus M-37 (leu1-), suggesting that the gene codes for alpha-IPMI of R. niveus. Both the transformation frequency and mitotic stability with pRN1 were higher than those with leuA gene-containing vectors. It was found by using the leul gene that the autonomously replicating sequence (ARS) of P. blakesleeanus partially functions as an ARS in R. niveus.

Amino Acid Sequence↗

PubMed1996

Characterization and pathogenicity of Haemophilus paragallinarum serotype C in local chickens of Taiwan.

Two strains (Strains 39 & B) of Haemophilus paragallinarum were isolated and identified as serotype C by dot-blotting analysis in Taiwan in 1994. To identify their virulence and pathogenicity in Taiwanese local chickens, local chickens were inoculated via nostril with the isolates, and examined for 14 days. Clinical signs of swollen face, and nasal discharge were first seen at 24 hr after inoculation, and the infectivity of Strains 39 and B at 14 days after inoculation among the inoculated chickens was 50.0-71.4% and 55.6-77.8%, respectively. From the results, we concluded that the two bacterial isolates were pathogenic to local chickens with a maximum morbidity of 77.8%.

Animals↗

PubMed1996

Effects of cryopreservation of DNA synthesis in the inner cell mass of in vitro matured/in vitro fertilized bovine embryos frozen in various cryoprotectants.

The rate of DNA synthesis in the inner cell mass (ICM) of frozen-thawed bovine embryos was examined. Bovine blastocysts derived from in vitro matured/in vitro fertilized oocytes were frozen with 1.8 M ethylene glycol (EG), 1.6 M propylene glycol (PG) and 1.4 M glycerol plus 0.25 M sucrose (GL). Viable embryos, after thawing and culture beyond the blastocysts stage, were examined by immunocytochemical staining for detection of DNA synthesis by ICM cells. The numbers of bromodeoxyuridine-immunoreactive ICM cells of frozen-thawed embryos prepared with EG (10.7) and GL (11.5) were significantly lower than those of unfrozen embryos (17.3). The results suggest that the rates of proliferation of ICM cells of frozen-thawed bovine embryos tend to be lower than those of unfrozen embryos irrespective of the cryoprotectant used.

Analysis of Variance↗

PubMed1996

Serovars of Erysipelothrix strains isolated from pigs affected with erysipelas in Japan.

Serovars of 1,046 Erysipelothrix strains isolated from diseased pigs during a period from 1983 to 1993 in Japan were determined by an agar gel double-diffusion precipitation system using typing sera representing all the known serovars, 1 through 23 and type N, of 2 species of Erysipelothrix. A total of 943 strains could be serotyped within the serovars. The remaining 103 strains could not be determined for their serovars and were classified as untypable. Of the 938 (99.5%) strains serologically identified as Erysipelothrix rhusiopathiae, 423 (40.4%) belonged to serovar 1a, 359 (34.3%) to serovar 2, 65 (6.2%) to serovar 1b, 35 (3.3%) to serovar 6, 19 (1.8%) to serovar 5, 11 (1.1%) to serovar 21, and the remaining 26 to serovars 4, 8, 11, 12, 15, 17, or 19. Only 5 (0.5%) strains isolated from the cases of erysipelas belonged to Erysipelothrix tonsillarum and represented serovars 7 or 23.

Animals↗

PubMed1996

Clara cell protein correlation with hyperlipidemia.

Serum levels of protein 1 (P1), a Clara cell secretory protein, in 746 healthy subjects were measured and their correlations with different types of serum lipids and lipoproteins-that is, triglyceride (TG), total cholesterol (TCh), free cholesterol (FCh), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and apoproteins (apo) A-I, A-II, and B-were examined. P1 serum levels were examined for their correlation with body mass index (BMI), and were compared for 47 obese, 70 normal, and 17 lean males. P1 serum levels in 69 patients with diabetes mellitus and 24 patients with atherosclerotic stenosis of the carotid artery or coronary artery were also compared to those in healthy control subjects. P1 showed a significant positive correlation with TG, TCh, FCh, apo A-I, apo A-II, apo B, and BMI (r = 0.93, 0.26, 0.42, 0.11, 0.35, 0.58, and 0.20, respectively; p < 0.0001 to 0.05), and an inverse correlation with HDL (r = -0.32; p < 0.01). P1 values in obese men (mean +/- SD: 139.2 +/- 98.2 micrograms/L) were significantly higher than those in normal (90.3 +/- 57.1) and lean ones (65.6 +/- 40.8) (p < 0.01). In both diabetic and atherosclerotic patients, P1 serum levels did not significantly differ from those in healthy subjects. From these results, we conclude the following: (1) the serum levels of P1 correlate significantly with those of lipids and lipoproteins; (2) P1 serum levels increase in the case of obesity.

Arteriosclerosis↗

PubMed1996

Clinical assessment of the pumping technique in treating TMJ arthrosis with closed lock.

The treatment of closed jaw locking due to temporomandibular joint (TMJ) arthrosis is described. Conventional mandibular manipulation of the lower and/or upper joint compartments was performed using hydraulic pressure from an imaging X-ray medium. The procedure was used in 40 patients with closed locking (5 acute and 35 chronic). The results of the treatment are evaluated and factors affecting the results are examined. In four of the five patients with acute closed locking, the lock was successfully released after use of the pumping technique on the lower joint compartment. In patients with chronic locking, an average improvement of 6.6 mm in the degree of interincisal opening was observed within 3-4 days of treatment with the pumping technique. In 13 of these patients, satisfactory opening (at least 40 mm) was achieved immediately. All the patients underwent further forward and contralateral manipulation to assist mouth opening, and after a period of 2-3 months 16 patients showed a further average improvement of 5.4 mm in interincisal opening.

Adolescent↗

PubMed1996

The plasminogen activation system is upregulated in loosening of total hip prostheses.

Interface tissues and pseudocapsules from loose total hip replacements were removed during revision of 11 cases and were investigated for the plasminogen activation system and IL-1beta. Control samples of synovium were taken during knee arthroscopy (n 8), and from the hip joint during primary total hip replacement (n 5). The concentrations of urokinase plasminogen activator (uPA), tissue type plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and interleukin 1beta were all found to be significantly different in interfaces and in pseudocapsules, compared to controls. Immunohistochemistry disclosed localization in periprosthetic tissues of uPA, uPA-receptor and tPA in macrophages with phagocytosed metal, polyethylene, cement particles or accompanying pieces of necrotic bone. PAI-1 staining was present in the neighboring areas that stained for uPA or tPA, but PAI-1 staining was also found overlapping and outside these areas. These findings suggest a role for the uPA/uPA- receptor and PAI-1 in activation and focalization of extracellular matrix degradation in periprosthetic tissues. The expression of the plasminogen activation system by macrophages containing phagocytosed material suggests undegradable microdebris as a possible initiating and perpetuating stimulus for a proteolytic activation cascade, which may contribute to loosening of the prosthesis.

Adult↗