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Biomedical subjects

T Kanda

Publications and source records attributed to T Kanda.

At least 541 records · Page 30Linked to original sources

Interferon induction by transfection of Sendai virus C gene cDNA.

To elucidate the mechanism of interferon (IFN) induction on virus infection, we constructed two types of plasmids by inserting a part of the cDNA of the Sendai virus into a simian virus 40-derived expression vector (pSV2-0). One, pSV2-PC, contained the P + C gene, which codes for the P and C proteins in overlapping reading frames, and the other, pSV2-C, contained only the C gene. After transfecting the plasmids into mammalian cells, we determined the IFN activity in the culture medium. We found that the level obtained with pSV2-PC was significantly positive but very low, whereas that obtained with pSV2-C was as high as or even higher than that observed in the culture medium after Sendai virus infection. By cleaving pSV2-C between the simian virus 40 promotor and the C gene or by inserting a stop codon within the C gene [pSV2-C(stop)], induction of IFN was greatly diminished. In Northern blot analyses of the transcripts obtained from the cells transfected with the plasmids with cDNA to the P + C gene as a probe, the transcript having the expected size was detected with both pSV2-C and pSV2-C(stop), whereas none was detected with cleaved pSV2-C or pSV2-0. The results indicate that both transcription and translation of the C gene seem to be required for IFN induction after Sendai virus infection.

Animals↗

Human papillomavirus type 16 transformation of rat 3Y1 cells.

The molecularly cloned, prototype human papillomavirus (HPV) 16 DNA has a single-base deletion in the El gene. We reconstructed a putative non-defective HPV 16 genome with an uninterrupted El gene, and examined its biological functions. The reconstructed HPV 16 DNA formed foci of morphologically transformed cells in transfected rat 3Y1 cell cultures (an immortalized normal cell line). The transformed rat cells contained transcriptionally active HPV 16 DNA, which appeared to be integrated within the cell DNA, and formed colonies in soft agar.

Animals↗

Morphological differentiation in Anopheles maculatus of Thailand accompanied with genetical divergence assessed by hybridization.

Anopheles maculatus of Thailand were distinguished morphologically into densely and sparsely scaled types and cross-mating experiments between these types revealed a substantial amount of genetic divergence. Progeny of wild females of An. maculatus collected throughout Thailand from north to south were examined morphologically with respect to adult tergal pale scales. Northern progeny broods could be separated into densely scaled (willmori) and sparsely scaled (maculatus) types, or W and M types, respectively. Using these two types of An. maculatus from Chiang Rai and Nakhon Phanom, cross-mating experiments were conducted, which resulted in sterile F1 male hybrids in one direction of cross and very low survival rate of F1 male hybrids in the reciprocal cross. However, southern broods could not be separated clearly because of intergradation of scaling. These results indicate that Thai An. maculatus involves at least 2 forms differentiated morphologically, as well as by incomplete reproductive isolation.

Animals↗

[Immunohistological observation of blood group-related antigens in lung adenocarcinomas using monoclonal antibodies].

The immunohistological distribution of blood group (BG)-related antigens including A, B, H type 2, and sialylated Lex in lung adenocarcinomas was examined using monoclonal antibodies. BG-A, B, and H type 2 compatible with the ABO status in tumor cells were expressed in 60% of the cases. Accumulation of H type 2, associated with loss of BG-A and B, was observed in tumor cells of patients with BG status other than 0. Tumor-associated antigens, Lex and sialylated Lex were detected in 36.0% and 72.0%, respectively. Modification of carbohydrate antigens in cancer may be associated with incomplete synthesis; accumulation of precursor antigen; and activated sialylation.

ABO Blood-Group System↗

[Prognostic factors in nonresected adenocarcinoma of the lung].

We have studied the prognostic factors of 117 cases of unresected adenocarcinoma of the lung, and have examined these cases according to the following categories: age, sex, clinical stage, performance status (P.S.), serum albumin on admission, serum CEA, the presence of complication, the present status of an abnormal chest shadow from a year ago at the same location, and differentiation of cells. Significant differences were detected in the P.S., the serum albumin and the presence of complications by survival analysis through the use of covariate-Cox models. We also have noted that the difference between stage I and the other stages of the clinical stage was found to be significant by a generalized Wilcoxon test. In conclusion, the determining prognostic factors of an unresected adenocarcinoma of the lung are the P.S., the serum albumin, the presence of complications and the clinical stage.

Adenocarcinoma↗

Hydration of cellobial by exo- and endo-type cellulases: evidence for catalytic flexibility of glycosylases.

New insight has been obtained into the catalytic capabilities of cellulase. Essentially homogeneous preparations of exo- (or Avicelase-) type and endo- (or CMCase-) type cellulases from Irpex lacteus and Aspergillus niger, respectively, were shown to hydrate the enolic bond of cellobial to form 2-deoxycellobiose. The A. niger enzyme also synthesized a small amount of a 2-deoxycellobiosyl-transfer product from cellobial. By use of digests conducted in deuterated buffer and 1H NMR spectra for product analysis, both cellulases were found to protonate (deuterate) the double bond of cellobial from below the si face of the D-glucal moiety, i.e., from a direction opposite that assumed for protonation of the beta-D-glycosidic linkages of cellulose and cellodextrins. The exo enzyme, which hydrolyzes the latter substrates primarily to cellobiose, rapidly catalyzed cellobial hydration to produce the beta-anomer of beta-D-glucopyranosyl(1----4)-2-deoxy-D-glucose-2(e)-d. The A. niger cellulase produced the same 2-deoxycellobiose-d from cellobial, though too slowly for its configuration to be determined. However, evidence was obtained for the formation of a beta-2-deoxycellobiosyl-d-D-glucose-transfer product by the enzyme. Thus, it is likely that all of the observed reactions with cellobial represent trans additions at the double bond. In any case, the anomeric configuration of products is created de novo. Separate mechanisms are described for the reaction of cellobial hydration and for the stereochemically different reaction of cellulose hydrolysis catalyzed by the present enzymes, assuming an arrangement of their catalytic groups analogous to that found in lysozyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspergillus niger↗

Congenital stationary night blindness with negative electroretinogram. A new classification.

An analysis of 64 patients with congenital stationary night blindness showed that all had essentially normal fundi. Electroretinography (ERG) showed a normal a wave with extremely reduced b wave (negative type) when recorded with a single bright white stimulus in the dark. We classified these patients into two groups based on the evaluation of rod ERG and/or psychophysical dark adaptation measured with an 11 degree test target at 15 degrees in the upper part of the retina. One group (35 patients) lacked rod function (complete type). Nine patients could not be classified. No pedigree showed a complete and incomplete type in one family. Differences between the two groups in refractive error, photopic function, and oscillatory potentials in the ERG suggest a different pathogenesis. Our analysis may provide a new classification of congenital stationary night blindness with a negative ERG.

Adolescent↗

Cloning of monomeric human papillomavirus type 16 DNA integrated within cell DNA from a cervical carcinoma.

We have molecularly cloned and characterized monomeric human papillomavirus type 16 DNA with flanking cell DNA sequences from a cervical carcinoma. Determination of nucleotide sequence around the junctions of human papillomavirus and cell DNAs revealed that at the site of integration within cell DNA the cloned viral DNA had a deletion between nucleotides 1,284 and 4,471 (numbering system from K. Seedorf, G. Krämmer, M. Dürst, S. Suhai, and W. G. Röwekamp, Virology 145:181-185, 1985), which includes the greater part of E1 gene and the entire E2 gene. In the remaining part of the E1 gene, three guanines were found at the location where two guanines at nucleotides 1,137 and 1,138 have been recorded. This additional guanine shifted the reading frame and erased an interruption in the E1 gene described by Seedorf et al. The data strongly suggest that, like other papillomaviruses, human papillomavirus type 16 has an uninterrupted E1 gene.

Base Sequence↗