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Biomedical subjects

H Wu

Publications and source records attributed to H Wu.

At least 829 records · Page 46Linked to original sources
PubMed1987

Purealin, a novel activator of skeletal muscle actomyosin ATPase and myosin EDTA-ATPase that enhanced the superprecipitation of actomyosin.

1. Purealin, a novel bioactive principle of a sea sponge Psammaplysilla purea, activated the superprecipitation of myosin B (natural actomyosin) from rabbit skeletal muscle. The maximum change in the turbidity increased with increasing purealin concentrations and was three times the control value in the presence of 50 microM purealin. 2. The ATPase activity of myosin B was also elevated to 160% of the control value by 10 microM purealin. On the other hand, purealin inhibited the myosin ATPase in the presence of 10 mM CaCl2 and 0.5 M KCl (Ca2+-ATPase), and the concentration for the half inhibition was 4 microM. 3. On the other hand, purealin activated the myosin ATPase in the presence of 5 mM EDTA and 0.5 M KCl (EDTA-ATPase). The maximum activation by 10 microM purealin was 160% of the control value. 4. Furthermore, similar results concerning the modification of ATPase activities by purealin were obtained in myosin subfragment-1 instead of myosin. 5. These results suggest that purealin activates the superprecipitation of myosin B by affecting the myosin heads directly. It is also an interesting observation that there is a correlation between the activities of the myosin EDTA-ATPase and actomyosin ATPase of myosin B.

Adenosine Triphosphatases↗
PubMed1987

Orally active prostacyclin-mimetic RS-93427: therapeutic potential in vascular occlusive disease associated with atherosclerosis.

RS-93427 is a potent, orally active prostacyclin-mimetic that is very rapidly absorbed but with generally long-lived actions in most species. It has antithrombotic, thrombolytic, and antivasospastic potential. Alone among several tested PGI-mimetics, it inhibits release of platelet mitogens more potently than its ability to inhibit aggregation. It also inhibits mitogen release from macrophages and vascular endothelial cells. RS-93427 is also potent at inhibiting macrophage accumulation of cholesteryl esters. These data suggest a broad spectrum of potential therapeutic utility for RS-93427 via the oral route. It might be useful both in acute manifestations of vascular occlusive disease involving thrombosis and vasospasm, in addition to the more chronic conditions involving intimal hyperplasia (as in arteriovenous grafts) and possibly frank atherosclerosis. Much work remains to be done, including examination of RS-93427 in chronic studies with various dosage forms, particularly in the study of atherosclerosis.

Administration, Oral↗
PubMed1987

[Reactivity of monoclonal antibodies ALT-01 and ALT-04 and identification of lung cancer-associated antigens].

Two IgG1 type monoclonal antibodies ALT-01 and ALT-04 were prepared by two different immunization schedules. ALT-01 was generated by fusing murine myeloma NS-1 cells with splenocytes from a BALB/c mouse immunized by human lung squamous carcinoma cells, which were coated by antisera to mixed human lymphocytes. For preparation of ALT-04, human lung squamous carcinoma xenograft-bearing nude mice were injected I. P. with the spleen cells of normal BALB/c mice in order to acquire immunofunction. The spleen cells from these tumor-bearing nude mice were fused with NS-1 cells. Then, these hybridomas were screened and cloned for 3 times. Two antibodies were shown to recognize the surface antigen on human lung carcinoma cells and several kinds of tumor cell lines but not those on normal cell lines. ALT-01 reacted to neither human lung carcinoma tissue nor its xenograft. ALT-04 reacted to human lung carcinoma tissue, of which, reaction to adenocarcinoma was the strongest but not to various normal tissues. Immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis and autoradiography was used to detect the associated antigen in 35S-labeled human lung carcinoma cells. Antigens, reacting to ALT-01, show one band of Mr 38,000 but those to ALT-04 reveal two bands of Mr 48,000 and 36,000.

Animals↗
PubMed1987

[Radioimmunodetection of human lung cancer xenografts by isotope labeling monoclonal antibody ALT-04 in nude mice].

Three nude mouse models bearing the human lung cancer were established from two fresh surgical specimens and one cell line. Tumor histological structure and cell morphology were similar before and after transplantation. The monoclonal antibody ALT-04 (McAb ALT-04) against human lung cancer was labeled by 125I, 131I and 201Tl. Radioimmunodetection study showed that all the three kinds of xenografts in nude mice were specifically located by McAb ALT-04. Imaging examination confirmed the ability of isotope labeling McAb ALT-04 to detect the presence of transplanted human lung cancer tissues without the aid of background subtraction manipulations. It is suggested that McAb ALT-04 have the possibility of locating in the tumor diagnosis and guiding in the treatment.

Animals↗
PubMed1985

Muramyl peptides and serotonin interact at specific binding sites on macrophages and enhance superoxide release.

Serotonin at low micromolar concentrations inhibited binding of two [125I]-labeled muramyl peptides to resident mouse peritoneal cells and to a macrophage-derived cell line, PU5-1.8-F7. Binding of [3H]serotonin was inhibited in parallel fashion. Overnight incubation with serotonin or muramyl peptide enhanced the release of superoxide by both types of cells when later stimulated with phorbol myristate acetate. Serotonin antagonists decreased binding of muramyl peptide and serotonin and diminished the subsequent enhancement of superoxide release. A cell line variant lacking detectable binding sites for muramyl peptide was far less responsive (superoxide release) than the parent line, to either drug. The data are consistent with sharing of a common set of receptors on the macrophage by muramyl peptide and serotonin and with involvement of these receptors in enhancing superoxide release.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1985

Localization of current dipole within a sphere by magnetic measurements.

The principal objective of this study is the development of computer programs to determine the location and strength of neural electric activity within the brain from noninvasive magnetic field measurements at the surface of the head. This report presents theoretical calculations and computer programs derived from the method described by Williamson and Kaufman to determine the depth and strength of a current dipole in a sphere. From the location of the magnetic field radial component extremes, Br maximum and Br minimum, the orientation and location of the current dipole can be determined. The accuracy of the solution is dependent on precise location of of the magnetic field extremes as measured from the surface of a sphere, e.g. the head. To validate the program for locating the dipole, theoretical calculations and computer programs related to the total magnetic field vector resulting from a hypothetical current source within a homogeneous sphere were generated. The errors in calculations of the current dipole depth and strength are presented.

Brain↗