Search PubMed⌕ Search

Biomedical subjects

F M Wu

Publications and source records attributed to F M Wu.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Effect of DGAVP and Org2766 on intracellular free Ca2+ concentration in dissociated brain cells].

Intracellular free calcium concentration ([Ca2+]i) was measured with Fura-2 in freshly dissociated brain cells isolated from newborn (1-2 day) mouse pups using AR-CM-MIC cation measurement system, and the effects of DGAVP and Org2766 on the changes in [Ca2+]i induced by the protein synthesis inhibitor anisomycin (ANI) were studied. The results indicate that anisomycin caused dose-dependent increases in [Ca2+]i; and DGAVP itself showed no significant effect on [Ca2+]i, but an appropriate dose of DGAVP antagonized the increases induced by the selective dose-range of ANI, suggesting that the antagonism of ANI-induced inhibition of protein synthesis by DGAVP was likely achieved by preventing ANI from increasing [Ca2+]i, but this mechanism did not apply to the other neuropeptide Org2766. Therefore, we suppose that the mechanism of the two neuropeptides are different in terms of their effect on intracellular free calcium concentration.

Adrenocorticotropic Hormone↗
PubMed1993

[Application of BEM in loaded stress analysis of rigidly fixed bridge].

Boundary Element Method(BEM) can be used successfully to the theoretical analysis of loaded stress of rigidly fixed bridge. Using BEM the numbers of dimension of the problem to be solved can be reduced by one. Compared with the Finite Element Method (FEM), BEM has the important features: less data to be input, simple data preparation, less CPU time, high efficiency, high accurate evaluation of stress etc. Besides more dense elements can be placed at selected points to be studied in order to reflect better the concentration of stress. The practice has shown that BEM is a valuable method for biomechanics analysis in prosthodontics.

Biomechanical Phenomena↗
PubMed1992

[Correlation between synaptic protein phosphorylation in hippocampi and shuttle box avoidance behavior].

The present investigation was undertaken to detect whether protein phosphorylation levels of hippocampal synaptosomes in mice trained on shuttle box avoidance task would show some changes. The synaptosomes were prepared at different times after the conclusion of training and labelled with gamma-32P-ATP for in vitro determination. The results are as follows: (1) No significant differences were found in the phosphorylation of synaptosomal proteins in different brain areas in normal mice before training. (2) Immediately after the conclusion of shuttle box avoidance task there appears a correlation between protein phosphorylation levels in hippocampal synaptosomes and the degree of success of training. (3) 24 h after the completion of training the above relationship is more significant, and protein phosphorylation levels of right hippocampus in Good Score Group is markedly higher than that of left one, but in the Inferior Score Group, the left-right difference is reverse. The formation of such asymmetry in protein phosphorylation in hippocampi is unknown. These data indicate that the synaptic protein phosphorylation in hippocampi might be a molecular mechanism of acquisition.

Animals↗
PubMed1991

The nucleotide sequence of Schwanniomyces occidentalis alpha-amylase gene.

The nucleotide sequence of the coding and regulatory regions of the alpha-amylase-encoding gene (AMY) of Schwanniomyces occidentalis has been determined. This sequence contained an open reading frame of 512 codons, from which a protein with Mr of 53,723 could be predicted. A putative signal sequence encoding for 25 amino acids was proposed for the 5' end of the open reading frame. Regulatory sequences, such as TATA box, CCAAT box and a signal sequence for polyadenylation and transcription termination could be found in the flanking regions of AMY gene. The deduced amino acid sequence also contained four common conserved regions characteristic of other alpha-amylase proteins.

Amino Acid Sequence↗
PubMed1989

Lipoperoxidation and T-cell leukemia of childhood. Effects of indomethacin.

Serum thiobarbituric acid (TBA) reactivity for lipoperoxidation products was assessed at diagnosis in children with T-cell and common acute lymphocytic leukemia (ALL) and T-lymphoblastic lymphoma. Comparisons were made among these groups and with healthy controls. Mean TBA reactivity (mumol malondialdehyde/L serum) was increased (P less than 0.01) in the T-cell leukemia group versus common ALL and T-lymphoblastic lymphoma patients and controls, respectively. The increase in lipoperoxidation products in T-cell ALL appeared to bear a positive relation to peripheral leukocyte counts, and was accompanied by increased serum prostaglandin E2 (PGE2) levels in most representative cases. Indomethacin added to a childhood T-cell ALL line (SUP-T3), at a concentration known to inhibit prostaglandin synthesis in vitro (i.e., 3 micrograms/mL), effected significant increases in the numbers of natural killer (NK; Leu-11+ and Leu-19+) cells (P less than 0.01) and B-lymphocytes (P less than 0.05), and significant decreases in cell viability (P less than 0.01). Indomethacin may be a useful agent for enhancing the antileukemic immune response in T-cell ALL.

Child↗
PubMed1989

Inhibition of myeloid differentiation by inhibitors of ADP-ribosylation.

Inhibitors of ADP-ribosylation inhibited the myeloid differentiation of murine myelomonocytic leukemia, WEHI-3BD+ cells induced by granulocyte colony-stimulating factor. Benzamide, at 2.0 mM, inhibited 50% of the WEHI-3BD+ cell differentiation but had no significant effect on the proliferation. However, benzylaminododecylguanine hydrochloride and p-methoxylbenzylaminodecamethylene guanidine sulfate at 2.0 and 2.2 microM, respectively, inhibited 50% of proliferation but had no effect at all on differentiation. The differential effects of inhibitors provide a model to study the role of ADP-ribosylation in myeloid differentiation.

Adenosine Diphosphate Ribose↗
PubMed1987

Differentiation of cultured promyelocytic leukemia cells (HL-60) induced by endotoxin-treated human lung conditioned medium.

Serum-free conditioned medium prepared from endotoxin-treated human lung tissue contains potent differentiation activity (DA) which induces the differentiation of human promyelocytic leukemia cells (HL-60) to mature functioning granulocytes and macrophages. Upon fractionation, the DA can be separated from colony-stimulating factors (CSFs). The estimated molecular weight of DA is 23,000 d which is similar to CSF-II but is much smaller than CSF-I (50,000 d). The isoelectric point (PI) value obtained from preparative isoelectrofocusing is 5.2, which is higher than CSF-I of 4.1-4.8 but lower than CSF-II of 5.6. Using isopropanol as solvent and trifluoroacetic acid (0.2%) as ion-pair, the DA is eluted at 37% isopropanol from the C-3 column in comparison to 30% for CSF-II and 34% for CSF-I.

Cell Differentiation↗
PubMed1986

Opiate antagonists and copulatory behavior of male hamsters.

A possible role of endogenous opioids in male copulatory behavior was examined in six experiments which studied the effects of opiate antagonists on the copulatory behavior of male hamsters (Mesocricetus auratus). In Experiment 1, the acute administration of naloxone hydrochloride (4 mg/kg, SC) ten minutes before testing significantly decreased mount frequency, intromission frequency, and ejaculation latency. In Experiment 2 males were tested weekly for three weeks. Half of the males were injected with naloxone ten minutes before each test and half with physiological saline. Naloxone administration reduced mount frequency, and intromission frequency while increasing the postejaculatory interval and the proportion of males displaying behavioral signs of satiety. In Experiment 3 similar effects were obtained following daily administration of naltrexone hydrochloride (10 mg/kg/day SC). In Experiment 4 males were allowed to mate to satiety. Naloxone treated males were more likely to display behavioral signs of satiety during the first ten minutes of these tests. In Experiment 5 it was demonstrated that naloxone administration did not alter the duration of insertion during either intromissions or ejaculations. In Experiment 6 the administration of naloxone did not facilitate the display of copulatory behavior by sexually inactive males. Overall the results are consistent with the hypothesis that opiate antagonists alter male copulatory behavior by enhancing the impact of stimuli occurring during the sexual interaction.

Animals↗
PubMed1986

[Effect of dexamethasone-A synthetic glucocorticoid hormone on the immune response in pigs].

These experiments were designed to study the effects of a synthetic drug--dexamethasone (DEX) on the immune response of weaned pigs against viral antigen (hog cholera vaccine) and bacterial antigen (formalin inactivated Salmonella enteritis vaccine). Twenty-three five-week-old pigs were divided into eight groups, six of which were injected twice daily with DEX at 1.0 mg or 0.1 mg per Kg of body weight for either four or five days. The other two groups served as controls. During this period, the two 0.1 mg/Kg DEX-treated groups were injected with live hog cholera vaccine at 1.0 or 0.1 dosage respectively. This same treatment was applied to the two 1.0 mg/Kg DEX-treated groups. One control group was injected with a dose of hog cholera vaccine, while the other was given 1.0 ml of Sal. enteritis vaccine. The hog cholera antibody response in DEX-treated pigs was significantly suppressed (p less than 0.01). However, consistent levels of antibody titers were maintained, indicating a slight antibody production. But in pigs injected with one tenth of the normal dose of hog cholera vaccine, there was little or no immune response (p less than 0.01). A comparison of the response of pigs given different levels of DEX concentrations to those with different doses of hog cholera vaccine showed that dexamethasone significantly suppressed antibody production when antigen concentrations were lower. Significant suppression of agglutinating antibody in response to bacterial antigen was also observed at 14 days post-vaccination (p less than 0.05).

Animals↗