[Drug identification and research on Fritillaria monantha Migo (pengze beimu) produced in Jiangxi Province]

This paper reports the drug identification and investigation on plant of Fritillaria monantha(Pengze Beimu) produced in Jiangxi Province. It has been found that F. monantha is a new distribution of genus Fritillaria in Jiangxi and a new variety of Chinese drug of beimu.

Developmental induction, purification, and further characterization of 12:0-ACP thioesterase from immature cotyledons of Umbellularia californica

The fatty acyl content of developing cotyledons of Umbellularia californica (California Bay) changes from a long-chain composition to a predominance of 10:0 and 12:0 in just 4-5 days at the beginning of an approximately 100-day period of medium-chain deposition. This striking change occurs at the earliest appearance of 12:0-acyl-carrier protein (ACP) thioesterase activity. The coincidence of these rapid events is consistent with the hypothesis that the enzyme plays a major role in medium-chain biosynthesis. The 12:0-ACP thioesterase has been substantially purified; enzyme activity consistently comigrates in chromatographic and electrophoretic systems with a protein or pair of proteins having an apparent molecular weight of approximately 34 kDa. A native molecular weight of approximately 42 kDa has been estimated by gel filtration chromatography, suggesting that the enzyme is a monomer. Affinity chromatography on immobilized ACP is a critical step in the purification procedure, and resolves the 12:0-ACP and 18:1-ACP thioesterases sufficiently to confirm that the medium-chain enzyme has negligible action on 18:1-ACP.

Deposition and characterization of thin ferroelectric lead lanthanum zirconate titanate (PLZT) films on sapphire for spatial light modulators applications

Ferroelectric lead lanthanum zirconate titanate (PLZT) films are deposited on R-plane sapphire using RF triode magnetron sputtering. Perovskite PLZT films with the desired composition (9/65/35) are obtained using compensated deposition techniques around 500 degrees C and postdeposition annealing at 650 degrees C. The deposited films exhibit good optical and electrooptical properties. The room temperature dielectric constant of the films was 1800 at 10 kHz. The refractive index of the films was in the range of 2.2-2.5. The films showed a quadratic electrooptic effect with R=0.6 x10(-16) m(2)/V(2). The development of PLZT on silicon-on-sapphire smart spatial light modulators using these films is also explored.

Methotrexate-induced resistance to dactinomycin in choriocarcinoma

NaUCC-2, a choriocarcinoma cell line, was derived from a patient who had a very poor clinical response to combination chemotherapy. Methotrexate (MTX) might have inhibited the antitumor effect of dactinomycin. To investigate this point, in vitro studies were performed to determine the sensitivity and uptake of MTX and dactinomycin (administered individually and in combination) to NaUCC-2 and three other choriocarcinoma cell lines. Dihydrofolate reductase (DHFR) concentrations were studied as well. Although NaUCC-2 showed sensitivity to MTX and dactinomycin, which were comparable to the other cell lines when they were given separately, NaUCC-2 was unique in that the combination of MTX and dactinomycin was less lethal than dactinomycin given by itself. The uptake of MTX in NaUCC-2 was significantly higher than that in the other cell lines, and MTX also induced an increase in dactinomycin uptake in NaUCC-2. There was no significant difference in DHFR activity. Although additional studies are necessary to determine the mechanism responsible for this effect, these findings suggest that a mechanism other than drug uptake or DHFR activity must play a role in the drug resistance for choriocarcinoma. These findings also suggest that the most commonly used combination chemotherapy for choriocarcinoma, dactinomycin and MTX, may not always be the best method.

An electron nuclear double resonance investigation of redox-induced electronic structural change at CuA2+ in cytochrome c oxidase

We measured an electronic change at cysteine ligand(s) of the CuA2+ center brought on by reduction of other metal centers within cytochrome c oxidase, notably cytochrome a. This change specifically manifested itself as a modification in magnetic hyperfine coupling to the beta-protons of the beta-carbons adjacent to the cysteine sulfur in the CuA2+ coordination sphere. The electron nuclear double resonance ENDOR signals of these beta-protons had previously been assigned through study of selectively deuterated yeast oxidase. In the present study the ENDOR signals of the CuA2+ center were compared from the following forms of oxidase: resting (a3+.CuA2+.a3+3.CuB2+); mixed valence, 2-electron-reduced CO-ligated oxidase (a3+.CuA2+.a2+3CO.CuB+), and a more completely reduced mixed-valence CO-ligated oxidase. In agreement with previous studies on 3-electron-reduced oxidase, the latter more completely reduced oxidase showed cytochrome a preferentially reduced with respect to CuA, implying that the majority of paramagnetic CuA2+ centers had reduced cytochrome a partners. The ENDOR-resolved splitting of the beta-proton hyperfine features substantially decreased in going from the first two more oxidized forms to the more fully reduced latter form. Thus, the electronic structure of the CuA2+ center specifically monitored by hyperfine couplings to cysteine protons changed in response to a reductive event elsewhere in the protein. This structural change may correlate with the anticooperative redox interaction recently reported between cytochrome a and CuA.

Radioimmunoassay of the serum free beta-subunit of human chorionic gonadotropin in trophoblastic disease

We developed a RIA specific for the free beta hCG employing anti-beta hCG monoclonal antibody 1D12. This RIA was highly sensitive to free beta hCG; the minimum detectable concentration was 0.4 ng/ml. alpha hCG, LH, beta LH, and FSH had little effect in the assay; the cross-reactivity of hCG was about 4%. Using this RIA, we measured serum free beta hCG concentrations in 38 normal pregnant women and 72 untreated patients with 3 types of trophoblastic disease: hydatidiform mole (n = 15), invasive mole (n = 29), and choriocarcinoma (n = 28). All of these samples were simultaneously assayed for hCG by RIA. In normal pregnant women, serum hCG changed as pregnancy progressed, but serum free beta hCG was not detected at any time. In contrast, serum free beta hCG was measurable in the majority of patients with trophoblastic disease. Strong correlations were found between the concentration of free beta hCG and that of hCG in each type of trophoblastic diseases. The mean free beta hCG to hCG ratio was lowest for hydatidiform mole and highest for choriocarcinoma, and the difference between the ratios in these 2 groups was statistically significant. Serial measurements in 7 patients with trophoblastic disease failed to reveal remarkable changes in the free beta hCG to hCG ratio throughout their clinical course. We conclude that the production of free beta hCG increases with the immaturity of the trophoblastic cell, and the degree of differentiation of trophoblastic cells may be reflected by the free beta hCG to hCG ratio.

[The study of drug sensitivity on newly established three choriocarcinoma cell lines]

After serial transplantation in nude mice, we had established three new human choriocarcinoma cell lines (NaUCC-1,2 and 3). These three cell lines and BeWo were examined for sensitivity to Act-D, MTX and the combined agents (Act-D + MTX) 3H-Act-D uptake and 3H-MTX uptake, and were compared for each treatment. NaUCC-1 showed low sensitivity to MTX (p less than 0.05), but showed high sensitivity to Act-D (p less than 0.05). BeWo showed low sensitivity to Act-D (p less than 0.05). In examining sensitivity to the combined agents (Act-D+ MTX), the sensitivity of NaUCC-2 to Act-D was decreased (p less than 0.05) by MTX added at the same time. In the 3H-Act-D uptake experiment, NaUCC-1 did uptake a relatively larger amount of 3H-Act-D (p less than 0.01) and BeWo a smaller amount of it (p less than 0.05). In the 3H-MTX uptake experiment, NaUCC-1 did uptake a relatively smaller amount of 3H-MTX (p less than 0.05), but NaUCC-2 uptook a larger amount of it (p less than 0.005). NaUCC-1 established from the patient in whom tumor cells were resistant to treatment, had a low response to MTX. NaUCC-2 was established from the patient in whom it was found that MTX inhibits the Act-D effect on tumor cells. In the study of combined agents in NaUCC-2, the growth inhibition effect of Act-D was suppressed by the MTX added.