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Biomedical subjects

B Gao

Publications and source records attributed to B Gao.

At least 163 records · Page 9Linked to original sources
PubMed1992

Effects of sub-chronic treatment with chlordiazepoxide, buspirone and the 5-HT3 receptor antagonist, BRL 46470, on the social behaviour of mice.

Chlordiazepoxide (21.5 mg/l; 5 mg/kg daily), buspirone (12.8 g/l; 3.4 mg/kg daily) and the 5-HT3 receptor antagonist, BRL 46470, (40 micrograms/l; 10 micrograms/kg daily) were each given in the drinking fluid for 12-14 days to adult male CD1 mice. Controls received tap water. Effects of the treatments on behaviour during 5 min social encounters with untreated partners were examined by ethological procedures in an aversive and less aversive situation, an unfamiliar neutral cage and the home cage. In the neutral cage all compounds increased the occurrence of the social act, "nose" and enhanced digging of the unfamiliar sawdust, at the expense of exploration. In the home cage, all compounds increased social investigation and reduced non-social activity. The drug BRL 46470 evoked more marked effects on behaviour than did buspirone or chlordiazepoxide and in the neutral cage it enhanced some acts of aggression. These results show that all compounds increased reactivity to normal social and environmental stimuli, in addition to their anxiolytic profile of behavioural effects.

Animals↗
PubMed1992

Clinical evaluation of radioimmunoimaging with 131I-C0C183B2 monoclonal antibody against ovarian carcinoma by intraperitoneal injection.

Forty-eight cases subjected to radioimmunoimaging (RII) by intraperitoneal injection with 131I-C0C183B2 monoclonal antibody (MAb) prepared in our laboratory were studied. Thirteen of 14 cases of proved primary ovarian carcinoma were positive. In 11 follow-up cases of ovarian carcinoma after initial surgery and chemotherapy, 5 recurrences were positive and 6 cases without recurrence were negative; all were confirmed histopathologically after a second operation. One false negative was ovarian mucinous adenocarcinoma, which also negatively stained with C0C183B2 by the peroxidase anti-peroxidase method. Twenty of 23 cases of nonepithelial or metastatic carcinoma of the ovary, benign tumors, and benign diseases were negative. The sensitivity and specificity were 94.7 and 89.7%, respectively. If patients had complications with ascites, the MAb which positively stained with the cancer cells in the ascites was chosen for RII. For follow-up cases PAP staining with the tumor tissue from the initial surgery and the MAb should be done before RII. These are the principal factors that increase the positive rate and accuracy of RII. The intraperitoneal route seems to be a valuable method for clinical staging and tumor localization as well as for follow-up use.

Adult↗
PubMed1992

[Expression and secretion of human interferon alpha A in yeast Kluyveromyces lactis].

The vector pE1 is derived from the plasmid pKD1 isolated from the yeast Kluyveromyces lactis. It can be maintained stably in the yeast K. lactis at high copy number. We explored the possibility of using the pKD1/K. lactis system for heterologous gene expression. The human interferon alpha A secretion cassette was inserted into pE1. The obtained plasmid, pE-IFN1, showed slightly instability when compared to pE1. The data showed that the secretion signal sequence of the alpha factor of Saccharomyces cerevisiae was functionally active in K. lactis. The K. lactis transformants carrying pE-IFN1 secreted efficiently IFN into the growth medium when they were grown in nonselective medium. The total amount of IFN released reached 1-2 mg per liter of culture supernatant.

Gene Expression↗
PubMed1991

Clorgyline-induced reduction in body temperature and its relationship to vigilance states in Syrian hamsters.

The antidepressant drug clorgyline, a monoamine oxidase inhibitor (MAOI) that selectively inhibits MAO type A was administered chronically to Syrian hamsters. Twenty-four-hour EEG sleep and/or telemetered peritoneal temperature were monitored during selected sampling periods over four weeks. Chronic clorgyline treatment decreased rapid-eye-movement (REM) sleep time and body temperature during the first week. Incomplete tolerance to these effects developed during the second and third weeks. REM sleep and body temperature were correlated during chronic clorgyline treatment. Non-REM (NREM) sleep was elevated throughout chronic treatment. These results suggest that clorgyline's effects on REM and NREM sleep might be related to clorgyline's effects on thermoregulation and to the development of tolerance. However, causal relationships between clorgyline's effects on thermoregulation and the levels of REM and NREM sleep remain to be determined.

Animals↗
PubMed1987

The G protein beta 2 complementary DNA encodes the beta 35 subunit.

Antisera were generated against synthetic peptides that correspond to amino acid sequences deduced from a cDNA (designated beta 2) that encodes a second form of the beta subunit of guanine nucleotide-binding regulatory proteins (G proteins). The specificity of interactions of these antisera with purified G protein beta subunits indicates that the beta 2 cDNA encodes the beta 35 form of this polypeptide. This hypothesis is confirmed by the use of these antisera to detect expression of the beta 2 cDNA in COS-m6 cells.

Base Sequence↗
PubMed1987

A second form of the beta subunit of signal-transducing G proteins.

A complementary DNA (cDNA) has been isolated that encodes a second form of the beta subunit of signal-transducing guanine nucleotide-binding regulatory proteins (G proteins). The cDNA corresponds to a 1.8-kilobase mRNA, and nucleotide sequence analysis indicates that the encoded polypeptide consists of 340-amino acid residues with a Mr of 37,335. Although the deduced polypeptide is the same size as that reported previously for the beta subunit, 10% of the amino acid residues are different. Furthermore, the 5' and 3' non-translated regions of this cDNA show no significant homology with those reported previously for cDNAs that encode the beta subunit. These data refute prior conclusions that there is only one form of the G protein beta subunit.

Adrenal Glands↗
PubMed1986

Sequence of mRNA coding for bindin, a species-specific sea urchin sperm protein required for fertilization.

Bindin, a major protein of the sea urchin acrosome granule, mediates the species-specific adhesion and binding of sperm to egg required to effect fertilization. We report the isolation and sequence of bindin cDNA clones prepared from Strongylocentrotus purpuratus testis RNA. The bindin gene appears to be productively expressed only in males and only in testes. The protein is produced from a 51-kDa precursor, which is subsequently processed to yield the mature 24-kDa bindin protein.

Amino Acid Sequence↗
PubMedDate not supplied

A site-directed mutant of Cu,Zn-superoxide dismutase modeled after native extracellular superoxide dismutase.

The well-studied cytosolic Cu,Zn-superoxide dismutase (SOD) protects against reperfusion injury, although its short (6 min) plasma half-life and negative charge create undesirable pharmacokinetics. We have designed, cloned, and expressed a genetic variant of SOD with altered pharmacological properties. A fusion gene consisting of the entire coding region of human SOD followed by a positively charged carboxy-terminal (C-terminal) "tail" of eight glycine and six arginine residues was constructed. The tail was modeled after the extracellular SOD (EC-SOD) C-terminal 26-amino acid basic peptide. This EC-SOD tail binds to heparin-like proteoglycans on cell surfaces and contributes to the enzyme's very long (30 h) plasma clearance time. After expression in Escherichia coli, the mutant enzyme was purified and characterized. No differences in specific activity or UV absorption spectrum between the mutant and the native enzyme were found. The thermal stability of the fusion protein was greater than that of native SOD. Although native SOD has no affinity for heparin, the modified enzyme bound to a heparin-agarose column. A "designer" SOD able to bind to cell surfaces may aid in the prevention of superoxide-mediated endothelial damage.

Amino Acid Sequence↗