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Biomedical subjects

B Q Li

Publications and source records attributed to B Q Li.

33 records · Page 2Linked to original sources
PubMed1994

[Abnormal partograph in primipara with vertex presentation].

A prospective study on partograph (cross X type) was carried out in primipara with vertex presentation. There were 50 cases of dystocia in the study group and 50 cases of normal delivery in the control group. The results showed that the latent phase and active period of labor course in study group was significantly longer than the control group (P < 0.001). The speed of cervical dilation and descent of fetal presentation in the study group was marked slower than the control group (P < 0.001). The rate of postpartum hemorrhage, total time of labor, operative delivery rate and neonatal asphyxia rate in the study group were significantly higher than the control group (P < 0.001). After active management 38 cases in the abnormal group were delivered vaginally. It suggested that the use of partography is very important in revealing abnormal labor course and detection of dystocia, guiding the management of labor.

Adult↗
PubMed1993

Mitogenic activation of the Ras guanine nucleotide exchange factor in NIH 3T3 cells involves protein tyrosine phosphorylation.

We report biochemical evidence that epidermal growth factor and platelet-derived growth factor stimulate the Ras guanine nucleotide exchange factor activity in quiescent NIH 3T3 cells. Moreover, the exchange activity is constitutively enhanced in NIH 3T3 cells transformed by Src and ErbB2 oncogenic tyrosine protein kinases (TPKs), whereas transformation by oncogenic Mos and Raf does not alter the activity. GTPase-activating protein activity was not affected under these conditions. Overexpression of pp60c-Src mutants containing activated and suppressor TPK mutations resulted in stimulation and inhibition of the exchange factor activity, respectively. A TPK inhibitor, genistein, prevented the activation of the exchange factor in epidermal growth factor/platelet-derived growth factor-treated cells and src-transformed cells. Furthermore, the exchange factor activity bound to an anti-phosphotyrosine antibody immunoaffinity column. These findings suggest that the guanine nucleotide exchange factor, but not GTPase-activating protein, plays a major role in the Ras activation in cell proliferation initiated by growth factor receptor TPKs and malignant transformation by oncogenic TPKs and that tyrosine phosphorylation of either the exchange factor or a tightly bound protein(s) may mediate the activation of the exchange factor by these TPKs.

3T3 Cells↗
PubMed1993

Inhibition of HIV infection by baicalin--a flavonoid compound purified from Chinese herbal medicine.

Baicalin (BA), (formulated as 7-D-glucuronic acid-5,6-dihydroxy-flavone), was purified from the plant Scutellaria Baicalensis Georgi. It has been used as a traditional Chinese herbal medicine. The inhibitory effect of BA against human immunodeficiency virus (HIV-1) infection and replication has been studied in vitro. The compound inhibits HIV-1 infection and replication as measured by: (1) a quantitative focal syncytium formation on CEM-ss monolayer cells; and (2) HIV-1 specific core antigen p24 expression and retroviral reverse transcriptase (RT) activity in the HIV-1-infected H9 cells. We have further demonstrated that the enzymatic activity of purified recombinant HIV-1/RT was inhibited by BA. In addition to lymphoid cell lines, the anti-HIV-1 activity of BA was also observed in cultures of primary human peripheral blood mononuclear cells infected with HIV-1 in vitro. Neither cytotoxic nor cytostatic effects on the indicator cells were found under the assay condition. This data suggests that BA may serve as a useful drug for the treatment and prevention of HIV infections.

Antiviral Agents↗
PubMed1992

Nerve growth factor stimulation of the Ras-guanine nucleotide exchange factor and GAP activities.

The biological activity of Ras proteins is thought to be controlled by the guanine nucleotide exchange factor and the guanosine triphosphatase activating protein (GAP). Treatment of rat pheochromocytoma PC-12 cells with nerve growth factor (NGF) increased the amount of active Ras guanosine triphosphate complex and stimulated the activities of both the guanine nucleotide exchange factor and GAP. In PC-12 cells that overexpressed the tyrosine kinase encoded by the trk proto-oncogene (a component of the high-affinity NGF receptor), the NGF-induced activation of the regulatory proteins was potentiated. These results suggest that the NGF receptor system enhances the activities of both the guanine nucleotide exchange factor and GAP and that the activation of Ras might be controlled by the balance in activity between these two regulatory proteins.

Animals↗
PubMed1991

A new class of anti-HIV agents: GAP31, DAPs 30 and 32.

Three inhibitors of human immunodeficiency virus (HIV) have been isolated and purified to homogeneity from Euphorbiaceae himalaya seeds (Gelonium multiflorum) and carnation leaves (Dianthus caryophyllus). These proteins, GAP 31 (Gelonium Anti-HIV Protein 31 kDa) and DAPs 30 and 32 (dianthus anti-HIV proteins, 30 and 32 kDa), inhibit HIV-1 infection and replication in a dose-dependent manner with little toxicity to target cells. The therapeutic indices of these compounds are in the order 10(4), suggesting that they may be clinically important agents in the treatment of AIDS. The N-terminal amino acid sequences of these proteins show little homology to those of previously described anti-HIV proteins. The structure-function features of these HIV inhibitors, based on the 40-60 amino acid residues of N-terminal sequences, are examined.

Amino Acid Sequence↗
PubMed1991

TAP 29: an anti-human immunodeficiency virus protein from Trichosanthes kirilowii that is nontoxic to intact cells.

An anti-human immunodeficiency virus (anti-HIV) protein capable of inhibiting HIV-1 infection and replication has been isolated and purified to homogeneity from Trichosanthes kirilowii. This protein, TAP 29 (Trichosanthes anti-HIV protein, 29 kDa), is distinct from trichosanthin [also known as GLQ 223 (26 kDa)] in size, N-terminal amino acid sequence, and cytotoxicity. In addition to three conservative substitutions--namely, Arg-29 to Lys, Ile-37 to Val, and Pro-42 to Ser--a total difference of residues 12-16 was found. TAP 29 yielded -Lys-Lys-Lys-Val-Tyr-, whereas trichosanthin has -Ser-Ser-Tyr-Gly-Val-. Although the two proteins exhibit similar anti-HIV activity, as measured by syncytium formation, p24 expression, and HIV reverse transcriptase activity, they differ significantly in cytotoxicity, as measured by their effects on cellular DNA and protein syntheses. At the dose level of the bioassays, 0.34-340 nM, trichosanthin demonstrates a dose-dependent toxic effect on host cells. TAP 29 displays no toxic effect, even at 100 X ID50, whereas trichosanthin demonstrates 38% and 44% inhibition on cellular DNA and protein synthesis, respectively. These results indicate that the therapeutic index of TAP 29 is at least two orders of magnitude higher than that of trichosanthin. Thus TAP 29 may offer a broader safe dose range in the treatment of AIDS.

Amino Acid Sequence↗
PubMed1991

Decrease in cytokine production by HIV-infected macrophages in response to LPS-mediated activation.

The capacity of human monocytes/macrophages (M/M) infected with a human immunodeficiency virus-1 (HIV-1) isolate to produce several immunomodulating cytokines including interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, IL-8, and macrophage chemoattractant and activating factor (MCAF) was examined. Although HIV infection itself induced significant increases in the level of mRNAs for IL-1 beta, TNF-alpha, IL-6, and IL-8, the levels of lipopolysaccharide (LPS)-induced mRNAs for IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, IL-8, and MCAF were decreased over those of uninfected LPS-stimulated cells. In addition, HIV-infected M/M produced lower amounts of IL-8 protein, as measured by radioimmunoassay over an 18-day culture period. These results suggest that HIV infection generally suppresses the LPS-inducible cytokine production in human M/M. The impact of the role of these cytokines in the immunity and pathogenesis of HIV-1 infection is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1988

[Multicentric carcinoma of the esophagus and double primary malignant neoplasm of the upper alimentary tract--report on 44 patients].

During the past fifteen years, 44 patients with multicentric carcinoma of the esophagus or double primary malignant neoplasm of the upper alimentary tract, collected from 5316 patients with cancer of esophagus or gastric cardia in the same period, were treated in our hospital. The incidence was 0.83%. All were proven by pathology. Exploratory thoracotomy was done in 32 patients and 26 lesions were resected with a resection rate of 81.3%. All patients with cancer resected survived over 1 year, 6 out of 9 survived over 3 years and 2 out of 3, over 5 years. In the 18 patients who received chemotherapy alone, 12 were followed and all died within 1 year. It is shown that multicentric carcinoma of the esophagus or double malignant neoplasm of the upper alimentary tract should be given energetic treatment. Finally, the incidence, diagnosis criteria, diagnosis method, etiology and management are discussed with a review of literature.

Adenocarcinoma↗
PubMed1982

Craniopagus parasiticus: a case report of a parasitic head protruding from the right side of the face.

An extremely rare case of parasitic head protruding from the right side of the face is presented. It differs from all the other cases previously reported in the literature. The patient had a parasitic head with an abnormal brain, two eyebrows, two underdeveloped eyes, nose, mouth, 12 teeth, a tongue and plenty of hair. The parasitic head was excised. The nature of the embryological abnormalities is discussed and the literature of polygnathism reviewed.

Abnormalities, Severe Teratoid↗