[Pharmacokinetics of puerarin in rats, rabbits, and dogs]

The puerarin was determined by HPLC with fluorescence detection. The plasma concentration-time course of puerarin in rats and dogs after iv was best fitted to a two-compartment open model, while that in rabbits was best fitted to a three-compartment open model. Species specificity was found among rats, rabbits, and dogs, calculated with compartment model program. The T1/2 beta after iv puerarin 9 mg.kg-1 in rats, rabbits, and dogs were 11, 21, and 67 min, respectively. There were no significant differences in pharmacokinetic parameters after iv 4.5-30 mg.kg-1 to rabbits and dogs.

Avian species-specific tandem repeats contain nuclear protein binding sites

Three avian highly repetitive tandem repeats were identified and examined. These repeats had similar unit lengths (about 42 bp long) but completely different sequences each containing particular protein binding sites. Each of these repeats was found within only one of the five closely related genera studied.

[Expression of human hepatoma associated antigen in relation to the cell cycle]

The expression of human hepatoma associated antigen A25 in relation to the different stages of cell cycle is reported as studied by monoclonal antibody and flow cytometry methods. A25 antigen was found to express all the four human hepatoma cell lines we tested. Hepatoma cell line PUMC-H1 expressed the antigen at higher levels than SMMC-7721 and QGY-7703 whereas BEL-7402 expressed at lower levels. Further studies showed that the cell lines PUMC-H1, SMMC-7721 and QGY-7703 were found to be at the similar stages of cell cycle while QGY-7703 was different from these three cell lines by having more cells in S state but fewer cells in G0-G1 stages. In the same cell line, A25 was expressed during all cell cycle stages though at different levels. It was expressed at the lowest level in G0-G1 stages, a slightly higher level in S stage and the highest in G2-M stage. The results in this paper suggest that the expression of A25 is related to the stage of cell cycle in the same cell line but not related to the stage of cell cycle in different cell lines with similar tissue origin.

Avian tandem repeats: nuclear protein binding sites and the origins of short tandem repetitive DNAS

A 14 bp repeat isolated from the genome of a Mallard duck (Anas platyrhynchos) and a 13 bp repeat isolated from the genome of a Muscovy duck (Cairina moschata) were both tandem and genus-specific. There were 2.1 x 10(6) copies of the 14 bp repeat in the Mallard duck genome and 1.3 x 10(6) copies of the 13 bp repeat in the Muscovy duck genome. These two repeats were not obviously homologous but each contains different transcription protein binding sites. Experimentally, the two repeats were also observed to bind nuclear proteins specifically. A sequence-selective mechanism for the expansion of short tandem repeats from single ancestral sequences containing nuclear protein binding sites is presented.

Cloning, sequence, and expression of a cDNA encoding hamster UDP-GlcNAc:dolichol phosphate N-acetylglucosamine-1-phosphate transferase

UDP-GlcNAc:dolichol phosphate N-acetylglucosamine-1-phosphate transferase (GPT) catalyzes the initial reaction required for synthesis of dolichol-P-P-oligosaccharides. We report here on the sequence and expression of a full-length cDNA clone encoding hamster GPT. The cDNA predicts a protein of 408 amino acid residues including 10 hydrophobic segments. Several portions of the hamster GPT sequence constituting one-third of the protein have 60% or greater identity with yeast GPT, and one-half of the conserved sequence falls within the hydrophobic segments. In addition, hamster GPT has two copies of a putative dolichol recognition sequence recently identified in three yeast enzymes that interact with dolichol. The protein lacks KDEL or DEKKMP-type carboxyl-terminal ER sorting sequences. When expressed in COS-1 cells, the cDNA causes a 5-7-fold increase of GPT activity in membrane fractions. The activity was completely inhibitable by tunicamycin, and the primary product was shown to be GlcNAc-pyrophosphoryldolichol. This cDNA represents the first enzyme of the dolichol-oligosaccharide biosynthetic pathway to be cloned from a vertebrate source and demonstrates structural homology between the enzymes of the yeast and mammalian pathways.

[Immunosuppressive effect of cultured Cordyceps sinensis on cellular immune response]

The immunosuppressive effect of cultured Cordyceps sinensis (Bei Lin Capsule) was studied in vitro and in vivo. When the drug was added from 0.6 mg/ml to 5 mg/ml a significant dose-dependent inhibition effect was shown in the following immune reactions of mice (P less than 0.05-0.01): phagocytic function of peripheral blood leucocytes assayed by chemiluminescence; mitogenic response of spleen lymphocytes to Con A; mixed lymphocyte culture and LPS induced interleukin-1 release of macrophages. The survival rate of mice spleen lymphocytes cultured with Cordyceps sinensis 5 mg/ml in 37 degrees C 5% CO2 for 5 days was more than 80%. Cordyceps sinensis 4 g/kg daily significantly prolonged the mice skin allograft survival time (12.7 +/- 2.2 days v.s. 8.3 +/- 0.7 days in the control, P less than 0.01) and its immunosuppressive effect was close to that of Cyclosporin A 5 mg/kg daily on skin allograft.

[The pharmacological activities of musk. III. On the mechanisms of its anti-inflammatory activities]

The water soluble fraction (WSF) of musk was shown to decrease the vitamin C content of the adrenal gland in mice and to increase plasma corticosterone levels in rats. The anti-inflammatory effect of WSF was not affected by hypophysectomy in the rat but was completely abolished by adrenalectomy in mice, indicating that the adrenal gland may play an important role in mediating the anti-inflammatory effect of musk. The WSF was capable of inhibiting ADP or collagen-induced platelet aggregation in rats. In the meantime, there was a potentiation of immunohemolysis in mice and an elevation of the plasma level of cAMP in rats. The implications of these changes in the anti-inflammatory effects of musk are discussed.

Amplification and molecular cloning of the hamster tunicamycin-sensitive N-acetylglucosamine-1-phosphate transferase gene. The hamster and yeast enzymes share a common peptide sequence

The first step in the assembly of the dolichol-linked oligosaccharides required for asparagine-linked glycosylation in eukaryotes is catalyzed by a tunicamycin-sensitive, dolichol phosphate-dependent N-acetylglucosamine-1-phosphate transferase (GPT). A fragment of the gene encoding the enzyme from Chinese hamster ovary (CHO) cells was partially cloned and characterized by a novel strategy. By stepwise selection, CHO cells were made 80-fold resistant to tunicamycin and found to have 10-fold elevated levels of GPT activity. Using a cloned segment of the yeast ALG-7 gene, which encodes the putative GPT from yeast, an amplified gene was identified by Southern blotting of the CHO DNA and a 6.6-kilobase segment of the gene was molecularly cloned. A family of RNA molecules in the 2.0-2.2-kilobase range identified with a probe from this gene was overexpressed in the resistant cells. The cloned DNA revealed a 24-amino acid residue sequence that was 92% conserved with the corresponding yeast sequence.

Vasovasostomy with use of medical needle as a support

Between May 1981 and December 1985 we performed vasovasostomy using a needle as a support in 43 patients who had undergone vasectomy for family planning. The operation is simple with little surgical trauma and few complications. All 39 patients who underwent semen analysis had return of spermatozoa. Pregnancy resulted in 27 of 34 patients (79.41 per cent) who attempted conception. The results were satisfactory. The procedure is described, and the complication and success rates are analyzed.