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Biomedical subjects

T Kanda

Publications and source records attributed to T Kanda.

At least 595 records · Page 33Linked to original sources

Morphometric analysis of sural nerve in elderly diabetes mellitus.

Biopsy specimens of the sural nerve obtained from 28 middle-aged and elderly diabetics suffering from neuropathy were studied morphometrically. Myelinated nerve fiber density, especially large fibers, was decreased, and the bimodal distribution of myelinated fiber diameter shifted to unimodal distribution containing only a small fiber peak and the mean diameter of myelinated fiber was decreased. An insulin-treated group and a group with severe retinopathy showed a prominent decrease of myelinated fiber density; the severity and duration of diabetes may be a factor in this decrease. Large unmyelinated nerve fibers were also decreased and the mean diameter of unmyelinated fibers was reduced. Three patients with prominent autonomic nervous system symptoms showed a significant reduction of total unmyelinated fibers. The linear correlation between the square root of the transverse axis cylinder area and the number of myelin lamellae was obscured, and the plots were towards two directions, axonal atrophy and remyelination in diabetes. The latter process tended to be dominant in the middle-aged patients, but the importance of these two processes was reversed with age. To discuss the morphological changes of the sural nerve in diabetic neuropathy, the influence of aging as well as the duration, severity and clinical symptoms should be considered.

Adult↗

Sequence of 3,687 nucleotides from the 3' end of Sendai virus genome RNA and the predicted amino acid sequences of viral NP, P and C proteins.

The sequence of 3,687 nucleotides from the 3' end of the Sendai virus genome (Z strain) was determined by a molecular cloning technique followed by rapid sequence analysis. Two large open reading frames, one consisting of 1,572 nucleotides and the other of 1,704 nucleotides, were observed in the region, that is OP-1 and OP-2 from the 3' end of the genome. The amino acid sequences of the gene products were predicted from the observed sequence. Determination of amino acid compositions of viral proteins, P, HN, Fo, NP and M, led us to conclude that NP and P are the gene products of OP-1 and OP-2, respectively. An additional open reading frame consisting of 612 nucleotides (OP-3) was discovered in the 3' most proximal region of OP-2. The predicted product of OP-3 was considered to be viral non-structural protein C. The leader sequence of 51 nucleotides at the 3' terminal of the genome and consensus sequences at 3' and 5' ends of each gene for proteins NP and P were identified.

Amino Acid Sequence↗

Undifferentiated carcinoma of the parotid gland. Case report with electron microscopic findings.

Two cases of undifferentiated carcinoma of the parotid gland were studied by light and electron microscopy. Light microscopy showed nests of ovoid cells with scanty cytoplasm and pyknotic nuclei in two cases. One case was the small-cell type, and another one was the large-cell type histopathologically. Electron microscopy showed two distinct cell types in each tumor: Case 1 (small-cell type). - An epithelial-like cell, and an irregular-shaped cell containing bundles of filaments suggesting myoepithelial differentiation. Case 2 (large-cell type). - An epithelial-like cell, and a large cell containing secretory-like granules. These findings support a salivary duct epithelial origin for these tumors.

Adult↗

Chronic sialadenitis of the submandibular gland (so-called Küttner tumor).

Two cases of chronic sialadenitis of the submandibular gland (so-called Küttner tumor) are reported. Clinically, they are asymptomatic except for firm swellings which are similar to neoplasms. Light microscopic observations revealed that the lesion is characterized by various degrees of atrophy and/or destruction of acini, infiltration of inflammatory cells, periductal fibrosis and lymph follicle formation. With the electron microscope, a marked increase of collagen fibers are observed throughout the gland parenchyma, and the secretory granules of acinal cells in the remaining acini remarkably decreased in number. We suggest that an autoimmune mechanism may play a role in case 1 and that an ascending infection through the duct system may be a main factor in case 2.

Adult↗

Transglycosylation activities of exo- and endo-type cellulases from Irpex lacteus (Polyporus tulipiferae).

Two highly purified cellulases, Ex-1 [exo-type, exo-cellobiohydrolase, EC 3.2.1.91] and En-1 [endo-type, EC 3.2.1.4] obtained from Driselase, a commercial enzyme preparation from Irpex lacteus (Polyporus tulipiferae), were used in this work. Both cellulases produced 14C-cellooligosaccharides such as 14C-G2 and 14C-G3 by transglycosylation when G3, G5, or beta-PNPC was used as a donor and 14C-G1 as an acceptor. However, the transglycosylation activity of Ex-1 was far higher than that of En-1. When Ex-1 or En-1 was incubated with beta-PNPG only, no p-nitrophenol was released, but it was readily released when G3 was added to the reaction mixture. In this reaction, the optimal donor (G3) concentration for Ex-1 was 1.0 mM, and the optimal pH values of Ex-1 were at 2.7 and 3.7 for beta-PNPG and beta-PG as acceptors, respectively, these values being far lower than the ordinary optimal pH values of the cellulase (4.0-5.0).

Basidiomycota↗

New beta-lactamase-resistant cephem treatment of guinea pigs infected with Legionella pneumophila.

The in vivo antimicrobial effect of seven new beta-lactamase-resistant cephems (cefotaxime, latamoxef, ceftazidime, ceftriaxone, cefotiam, cefbuperazone, and MT-141) on Legionella pneumophila (strain 81-066, serogroup IV) in guinea pigs was compared with that of erythromycin. As the minimal LD100 within one week was about 4.0 X 10(9) CFU/ml by intraperitoneal injection of the strain, the animals were inoculated with 2.0 ml of twofold dilutions of a suspension of this bacterium. The animals developed purulent peritonitis and systemic involvement demonstrated by the development of periangitis, pneumonia and pleuritis in the lungs. Three different doses of antibiotics were administered intraperitoneally immediately after the rectal temperature reached more than 40 C. Erythromycin had a significant therapeutic effect but none of the new cephems tested death of the infected guinea pigs.

Animals↗

Neuraminidase activity and syncytial formation in variants of parainfluenza 3 virus.

By a sensitive fluorometric assay method, we could definitely demonstrate neuraminidase activity for two variants of parainfluenza 3 virus, M and SC, which were previously shown to have no detectable neuraminidase activity. The enzyme activities of these viruses were very similar to each other, showing a much lower catalytic rate, a much higher Km value, and a more acidic pH optimum than those of the virus variants of high neuraminidase activity, 910N, LT, and MR. M and SC viruses eluted from guinea pig erythrocytes very poorly, whereas 910N and LT viruses eluted readily. M virus required the aid of a bacterial neuraminidase for effective growth and plaque formation in MDBK cells, but the virus grew well and formed plaques in R66 and Vero cells without the enzyme. SC virus required no exogenous neuraminidase for growth in all of these cell types. Depending on cell type, SC virus induced slight to extensive syncytial formation which was greatly inhibited by exogenous neuraminidase. In contrast, M virus induced extensive syncytial formation in all these cells regardless of the presence or absence of exogenous neuraminidase, although development and disintegration of the syncytia were more or less retarded by the enzyme, especially in MDBK cells. These results indicate that M virus possesses highly potent inducibility of syncytial formation which is further fortified by being low in viral neuraminidase activity.

Adsorption↗

Alignment of the genome of monkey B-lymphotropic papovavirus to the genomes of simian virus 40 and BK virus.

We located the origin of DNA replication of African green monkey B-lymphotropic papovavirus DNA by analyzing pulse-labeled form I DNA. With the replication origin used as a reference point, the B-lymphotropic papovavirus genome was aligned with the genomes of simian virus 40 and BK virus from DNA homology between specific fragments hybridized under low-stringency conditions. From the results of these experiments, it was possible to deduce the correlation between the physical and functional maps of the B-lymphotropic papovavirus genome.

BK Virus↗

Neuromuscular junctions of the posterior cricoarytenoid muscle in the cat.

The motor end plate of the cat posterior cricoarytenoid muscle is examined by using electron microscope and histochemical method. Furthermore, we studied the localization of acetylcholine receptors by fluorescent staining of snake neurotoxins (alpha-bungarotoxin and erabutoxin b) and autoradiography of 125I-labeled alpha-bungarotoxin. The fine structure of the motor end plate of this muscle is approximately identical to that of other singly innervated skeletal muscles. The subneural apparatus is activated by cholinesterase (ChE). ChE reaction appears markedly in primary and secondary synaptic clefts. No remarkable difference is found between TMR-labeled neurotoxin and FITC-conjugated neurotoxin. Fluorescent staining is associated with subsynaptic muscle membranes and not with motor nerve terminals. The autoradiogram revealed heavy accumulations of grains at the junctional folds.

Animals↗

Esterase patterns of Anopheles dirus (Bangkok strain) and Anopheles balabacensis (Perlis form) in the laboratory.

Esterase isoenzyme were performed in Anopheles balabacensis (Perlis Form) and Anopheles dirus (Bangkok Strain and Kanchanaburi Strain). The zymogram showed four positions, E1, E2, E3 and E4. Seventy-five percent of An. balabacensis (Perlis Form) or An. dirus (Bangkok Strain) can be correctly diagnosed by the presence of fast band in E3 or super slow band in E3 respectively. Homozygous slow band of E3 cannot be fully distinguished in both species, but by the combination of E2 and E3, 99.42% can be correctly identified to differentiate species.

Animals↗

Trehalase: stereocomplementary hydrolytic and glucosyl transfer reactions with alpha- and beta-D-glucosyl fluoride.

A new understanding has been obtained of the catalytic capabilities of trehalase, an enzyme heretofore held to be strictly specific for hydrolyzing alpha, alpha-trehalose and devoid of transglycosylative ability. Highly purified rabbit renal cortical trehalase and a partly purified Candida tropicalis yeast trehalase were found to utilize both alpha- and beta-D-glucosyl fluoride as substrates. In each case, the reactions were competitively inhibited by alpha, alpha-trehalose. Both enzymes catalyzed rapid hydrolysis of alpha-D-glucosyl fluoride to form beta-D-glucose (also, of alpha, alpha-trehalose to form equimolar alpha- and beta-D-glucose). In addition, digests of beta-D-glucosyl fluoride plus alpha-D-[14C]-glucopyranose with either trehalase (but not controls of enzyme with alpha-D-[14C]glucopyranose alone) yielded small amounts of radioactive trehalose (alpha-D-glucopyranosyl alpha-D-[14C]glucopyranoside) which does not accumulate since it is rapidly hydrolyzed. Trehalase thus catalyzes two stereocomplementary types of glycosylation reactions: (I) alpha-D-glucosyl fluoride (or alpha, alpha-trehalose) + H2O leads to beta-D-glucose + HF (or alpha-D-glucose); (II) beta-D-glucosyl fluoride + alpha-D-glucopyranose leads to alpha, alpha-trehalose + HF. Such behavior shows that the catalytic groups of trehalase, as recently found for other glycosylases, are functionally flexible. The results illustrate the inadequacy of conventional views of carbohydrase specificity and the rigor, as a basic guiding principle, of the concept that glycoside hydrolases and glycosyltransferases form a class of glycosylases effecting glycosyl/proton interchange.

Animals↗

A sensitive colorimetric assay for thrombin, prothrombin and antithrombin III in human plasma using a new synthetic substrate.

Benzoyl-L-leucyl-L-alanyl-L-arginine-alpha-naphthylester (Bz-Leu-Ala-Arg-NE) was synthesized as a new substrate for use in the assay of thrombin. In the assay alpha-naphthol released by the enzyme reaction was measured colorimetrically. With Bz-Leu-Ala-Arg-NE as substrate, the minimum detectable concentration of human thrombin was 0.0025 U. This assay using Bz-Leu-Ala-Arg-NE is a highly sensitive method for detecting prothrombin, thrombin and antithrombin III in human plasma. Prothrombin could be determined with 0.2 microliter of human plasma using Echis carinatus venom (ECV) as activator. Antithrombin III activity could be determined with 2 microliter of human plasma using human thrombin and heparin as cofactor. A zymogram of human prothrombin was prepared with Bz-Leu-Ala-Arg-NE as substrate. The preparation gave one band (pI 4.9) on polyacrylamide disc gel isoelectrophoresis.

Antithrombin III↗