[Botanical origins of Chinese drug caowu produced in Sichuan]

We have made an investigation on the botanical origins of 6 species and 2 varieties of the traditional Chinese drug Caowu produced in Sichuan, and found out that the main species available on the market are Aconitum hemsleyanum and A. hemsleyanum var. leucanthum, while A. legendrei comes second. A key for their identification is presented in this paper.

[Ion-paired high performance liquid chromatographic determination of mitoxantrone hydrochloride injection]

Mitoxantrone (DHAQ) is a new anti-cancer agent. The ion-pair HPLC method to determine mitoxantrone hydrochloride injection was proposed. Mitoxantrone can be separated on Zorbax-ODS column with methanol-water-formic acid (450:50:1.5) containing 3.605g SDS as mobile phase. The pH of mobile phase was adjusted to 2.7. The flow rate was 1.0 ml/min and detection was at wavelength of 254 nm, providing a detection limit of 1ng (r/n, 3:1) of DHAQ. DHAQ was determined by peak area measurement with ametantrone as internal standard. The rectilinear calibration graph in the range of 1-10 micrograms of DHAQ was obtained (r = 0.999 2). The average recovery was 99.62 +/- 2.36% (n = 10), and the results were not interfered by the other ingredients in the injection.

Reflectance diagram-aided technique for optical coating design and monitoring

An amplitude reflectance diagram is a useful tool for visualizing the relationships between the performance of an optical coating and the optical parameters. This paper gives a brief description of the construction and characterization of the reflectance diagrams for different indices. Then, applications of reflectance diagramaided techniques to the design of both phase dispersion-induced narrow reflection and transmission filters, as well as to the optical monitoring of the symmetric multilayers of types (A2BA) and (AB2CBA), are illustrated. Some experimental results of phase dispersion-induced narrowband filters are reported.

Diagnostic value of plasma PABA level in pancreatic diseases

NBT-PABA test was performed in 72 subjects with simultaneous determination of the plasma PABA time-concentration curve. The curve in 25 controls after oral administration of N-benzoyl-L-tyrosyl-P-aminobenzoic acid (NBT-PABA) peaked (3.88 +/- 0.78 micrograms/ml, M +/- SD) at the third hour. In patients with chronic pancreatitis (24) and pancreatic carcinoma (6), the curves were flattened, and peaked at the fifth hour (2.7 +/- 1.4 micrograms/ml, M +/- SD), and fourth hour (3.14 +/- 2.26 micrograms/ml, M +/- SD), respectively. The discrimination between the controls and patients with chronic pancreatitis was most significant in the third-hour plasma PABA concentration (P less than 0.0001). This study shows that determination of the third-hour plasma PABA concentration is better in sensitivity and specificity than the 6-hour urinary excretion of PABA, suggesting that the third-hour plasma PABA concentration after oral administration of NBT-PABA might be a sensitive index of exocrine pancreatic function test.

Initiation events in in-vitro packaging of bacteriophage phi 29 DNA-gp3

Initiation events in the packaging of bacteriophage phi 29 DNA-gp3 (DNA-gene product 3 complex) were studied in a completely defined in-vitro system that included purified proheads, DNA-gp3 and the DNA packaging protein gp16. In the sequential interactions, gp16 first bound to, and was modified by, the prohead. The prohead-gp16 complex then bound to DNA-gp3, resulting in a second modification of gp16 that permitted binding of ATP. DNA-gp3 aggregates were produced, and the hydrolysis of ATP accompanied DNA-gp3 packaging. Binding and hydrolysis of ATP by gp16 was both prohead- and DNA-gp3-dependent. Interruption of packaging by DNase I addition revealed filled heads but few particles containing partial lengths of DNA, suggesting that following a rate-limiting initiation, the translocation of DNA-gp3 into the prohead was much faster in the defined in-vitro system than in extracts.

Prohead and DNA-gp3-dependent ATPase activity of the DNA packaging protein gp16 of bacteriophage phi 29

The ATPase activity of the DNA packaging protein gp16 (gene product 16) of bacteriophage phi 29 was studied in the completely defined in-vitro assembly system. ATP was hydrolyzed to ADP and Pi in the packaging reaction that included purified proheads, DNA-gp3 and gp16. Approximately one molecule of ATP was used in the packaging of 2 base-pairs of phi 29 DNA, or 9 X 10(3) ATP molecules per virion. The hydrolysis of ATP by gp16 was both prohead and DNA-gp3 dependent. gp16 contained both the "A-type" and the "B-type" ATP-binding consensus sequences (Walker et al., 1982) and the predicted secondary structure for ATP binding. The A-type sequence of gp16 was "basic-hydrophobic region-G-X2-G-X-G-K-S-X7-hydrophobic", and similar sequences were found in the phage DNA packaging proteins gpA of lambda, gp19 of T7 and gp17 of T4. Having both the ATP-binding and potential magnesium-binding domains, all of these proteins probably function as ATPases and may have common prohead-binding capabilities. The phi 29 protein gp3, covalently bound to the DNA, may be analogous in function to proteins gpNul of lambda and gpl of phi 21 that bind the DNA.

A defined system for in vitro packaging of DNA-gp3 of the Bacillus subtilis bacteriophage phi 29

The bacteriophage phi 29 DNA-gene product 3 complex (DNA-gp3) has been efficiently packaged into proheads in a completely defined in vitro system. The phi 29 DNA packaging protein gp16, the product of gene 16, was overproduced in Escherichia coli and purified to near homogeneity. The purified gp16 packaged 23% of the DNA-gp3 added to purified proheads in the defined mixture, while gp16 in an extract of phage-infected cells packaged 26% of the DNA-gp3. No host proteins were required in the defined system. ATP-dependent packaging of DNA-gp3 in the defined system was optimal with approximately equal to 100 copies of gp16 per DNA-gp3, an amount similar to the production of gp16 per DNA-gp3 in phi 29-infected cells.