Biomedical subjects

K Konno

Publications and source records attributed to K Konno.

692 records · Page 39Linked to original sources

PubMedDate not supplied

Chemical modification potentiates paramylon induction of antimicrobial activity.

Induction of antimicrobial activity by two water-insoluble polysaccharides, paramylon and TAK, was significantly potentiated by introduction of positively charged groups (such as N,N-dimethylaminoethyl; N,N-diethylaminoethyl; and 2-hydroxy-3-trimethylammoniopropyl), but not by introduction of negatively charged groups (such as carboxymethyl or sulfate). Cross-linking of these derivatives with epichlorohydrin did not increase their potentiating activity. The effects of these derivatives did not always correlate with their ability to accumulate polymorphonuclear cells and to stimulate the generation of luminol-dependent chemiluminescence by peritoneal exudate cells.

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PubMedDate not supplied

Induction of antiparasite activity by pine cone lignin-related substances.

Pretreatment with two distinct lignin-related antitumor substances extracted from pine cone of Pinus parviflora Sieb. et Zucc. protected infant mice from Hymenolepis nana (Cestoda) infection. Subcutaneous administration of these fractions (10 mg/kg) to 1 week old mice evoked strong protective immunity against oral infection by Hymenolepis nana eggs. Significant antiparasite effects were also induced in 4 week old mice by intraperitoneal or oral administration of these fractions. These fractions had more potent antiparasite activity than pine cone extracts with lower antitumor and antiviral activity, and various polysaccharides derived from plants and bacteria.

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PubMedDate not supplied

Inhibition of herpes simplex virus infection by pine cone antitumor substances.

Several antitumor substances extracted from cones of various pine trees inhibited the plaque formation of Herpes simplex virus types 1 and 2 (HSV-1, HSV-2) strains in African green monkey kidney cells and human adenocarcinoma cells. The 50% effective dose of the most active fraction, Fr. VI (0.3 micrograms/ml) was 0.001 times its 50% cytotoxic dose (greater than 300 micrograms/ml). The anti-HSV activity of various pine cone extracts increased with their acidity. Identification of the polyphenol groups as donors of the acidity was further supported by the observation that the anti-HSV activity of the natural polyphenolic products, such as tannin and lignin, significantly exceeded that of other natural or chemically modified antitumor polysaccharides. An experiment using radiolabeled virus particles indicated that the anti-HSV effect of both Fr. VI and lignin was attributable to interference with virus adsorption to these cells rather than to inhibition of virus penetration into the cells.

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PubMedDate not supplied

Synergism of prostaglandin E2 plus TNF in induction of differentiation of human monocytoid leukemic U-937 cells.

Prostaglandin E2 (PGE2) induced differentiation of human monoblastic leukemia U-937 cells into cells with macrophage characteristics. PGE2 synergistically increased the differentiation, of U-937, ML-1 and HL-60 cells when combined with TNF. PGE1 and PGF2 also induced differentiation of U-937 cells; however, PGD2, deoxy-delta 9,12-13, 14-dihydro-PGD2 (delta 12-PGJ2), and PGI2 did not induce differentiation, either alone or in combination with TNF. PGE2 changed the dissociation constant of TNF for its receptors on U-937 cells only marginally, but it approximately doubled the number of binding sites.

Cell Differentiation↗

PubMedDate not supplied

Molecular species of the antitumor and antiviral fraction from pine cone extract.

The most active fraction (Fr. VI) of antitumor and antiviral pine cone extract was subjected to chemical structure analysis. IR, UV, and ESR spectroscopies, in addition to chromatographic analysis on cellulose-TLC plates, reveal that the major component of Fr. VI includes structures belonging to the lignin family. A commercial alkali-lignin showed antiviral activity and granulocyte iodination stimulating activity as effective as those of Fr. VI, but had much weaker immunopotentiating activities, such as antitumor and antimicrobial activities and splenocyte stimulating activity. As a tentative conclusion, the active principle of Fr. VI might be complex(s) of lignin-like polyphenolic skeleton with a molecular matrix of unknown components.

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PubMedDate not supplied

Mitogenic activity of pine cone extracts against cultured splenocytes from normal and tumor-bearing animals.

An acidic pine cone extract, Fr. V. of Pinus parviflora Sieb. et Zucc. significantly stimulated DNA synthesis of isolated splenocytes from both mice and rats, but only marginally affected the DNA synthesis of leukemic cell lines. The maximum stimulation level attained by Fr. V slightly exceeded that of plant lectins, whereas much weaker stimulating activity was found in natural and chemically modified antitumor polysaccharides, sialic acid-rich glycoproteins, and polyphenolic compounds such as lignin and tannic acid. In mice with subcutaneously transplanted sarcoma-180, responses of splenocytes against Con A declines in the terminal stage of tumor development, whereas responses against Fr. V remained relatively constant throughout all periods of tumor progression. The suppression of Fr. V activity by acetylation or methylation suggests the importance of the hydroxyl group in the expression of its stimulation activity.

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PubMedDate not supplied

Induction of antimicrobial activity by antitumor substances from pine cone extract of Pinus parviflora Sieb. et Zucc.

Pretreatment with two distinct antitumor substances extracted from pine cone of Pinus parviflora Sieb. et Zucc. protected mice from the lethal effects of E. coli infection. Intraperitoneal administration of these fractions transiently induced differentiation-inducing factor (DIF) with a peak at 1-2hr. The rapid decay of DIF activity from the peritoneal cavity was followed by polymorphonuclear cell (PMN) accumulation and enhancement of superoxide generation (assayed with luminol-dependent chemiluminescence (LDCL] by peritoneal exudate cells. The superoxide generation by adherent cells was similarly enhanced by pretreatment, but was only 10-20% of that of the peritoneal exudate cells. Fractions that showed comparable antitumor/antimicrobial activity were also obtained from seed shells and cones of other pine trees of Japanese and foreign origin. On the other hand, a neutral polysaccharide fraction from Pinus parviflora Sieb. et Zucc. that lacked any of these activities did not induce PMN accumulation, DIF activity or LDCL generation. The results suggest a significant role in PMN activation for the expression of antimicrobial activity induced by pine cone extracts.

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PubMedDate not supplied

Antitumor activity of polysaccharide fractions from pine cone extract of Pinus parviflora Sieb. et Zucc.

Hot water extract of pine cone (PCE) of Pinus parviflora Sieb. et Zucc. dose-dependently suppressed both solid and ascites tumor cells transplanted into various mice. Acidic polysaccharides of PCE significantly increased the survival time of mice bearing ascites tumor cells, and activity increased with acidity. One of the four polysaccharide fractions obtained by NaOH extraction showed the most potent antitumor activity. This fraction significantly suppressed the growth of solid tumor cells, with occasional tumor regression and necrosis, and with little or no cytocidal effect on cultured tumor cells. All acidic polysaccharides were able to activate mouse macrophage-like cell line J774.1. There did not appear to be any correlation between the antitumor activity of these polysaccharides and their content of arabinose (or fucose), mannose, galactose, glucose, or uronic acid.

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