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The human cytomegalovirus protease (CMVP) can be inhibited by compounds that are related to flavins. Inhibition, in this case, takes place through a oxidation-reduction reaction that affects both the sulfhydryl groups of CMVP and the oxidized form of the inhibitor. Experimental results indicate that the human cytomegalovirus protease is also inhibited by riboflavin and flavin analogs through the formation of disulfide bonds.

The DNA-cleaving behaviors of calicheamicin T, a calicheamicin derivative which lacks the B-C-D rings of the carbohydrate tail, and calicheamicin gamma(super 1) were investigated. Calicheamicin T showed no DNA site selectivity, indicating that the cyclized rings of calicheamicin are not involved in site recognition. On the other hand, calicheamicin gamma(super 1) cleaved site-specifically, but recognized both A-T and G-C rich tracts, depending on their context. These results demonstrate that calicheamicin gamma(super 1) is an unusual minor-groove binder.

In recent years, a lot of research focuses on atmospheric pressure glow discharge, but how to obtain a stable and uniform large-volume glow discharge at atmospheric pressure is still a difficult technological problem, especially in large ambient air gap. In this paper, with an external axial magnetic field applied in the pin-to-plate electrode gap, a stable and diffusive atmospheric pressure glow discharge in ambient air is obtained. Influences of different factors such as the output-voltage amplitude of the power supply, the intensity of the magnetic field, the resonant frequency of power supply, and different inter-electrode gap sizes are studied. The results show that a more diffusive and bigger-volume glow discharge can be obtained by increasing the amplitude of the output voltage of the power supply, the intensity of the external magnetic field, or the resonant frequency in the longer-distance pin-to-plate gap. [ABSTRACT FROM AUTHOR]

It has been possible to isolate two strong anti-tumour antibiotics, lomaiviticins A and B, with dimeric diazobenzofluorene glycoside structures, from the cultural broth of Micromonospora lomaivitiensis. This marine-invertebrate-associated microorganism offers considerable potential for new bioactive natural products.

The orange ascidian Polysyncraton lithostrotum was collected from Namenalala Island as part of efforts to investigate marine invertebrates from the Fiji Islands. Induction of SOS response in an agar-based biochemical induction assay (BIA) and a similar cytotoxicity profile to calicheamicin in a 26 cell line human tumor panel were gleaned from a methanolic extract of the organism. These indicated a DNA cleavage agent. A new enediyne antitumor antibiotic namenamicin in 10(super -4)% yield was generated from fractionation of the extract using the BIA assay.

A capacitor sensor with a high-voltage electrode inside the GIS tank has the best bandwidth among the sensors developed to measure the very fast transient overvoltage (VFTO). However, the low-voltage arm of the current measurement system is usually a handmade film capacitor which has disadvantages of unassigned capacitance value, temperature effect, and short lifespan. With a novel lower voltage arm based on surface-mounted devices, a wide-bandwidth, stable, and easy maintenance measuring system is proposed in this paper. It is found that the slight inherent inductance in the ground trace of the printed-circuit board can induce unexpected oscillations, which are demonstrated with theoretical analysis and experimental study. With the reforming of the printed-circuit board layout, the oscillation is reduced and 200-MHz high-frequency cutoff frequency is achieved. The environment experiment shows that the temperature effect on the developed sensor is much smaller than that on the conventional sensor. The VFTO generated by disconnector operation in 1100-kV GIS is measured by the developed system and a conventional broadband capacitor sensor. The contrastive results prove that the characteristic of the measuring system can meet the requirement of VFTO measurements. Thousands of measurements on ultra-high voltage GIS indicate that the developed measuring system is stable, and characteristics of the VFTO are gained. [ABSTRACT FROM PUBLISHER]

Macrophages from the head kidney (HK) and peripheral blood leucocytes were isolated from Cyprinus carpio by Percoll gradient density centrifugation, cultured in vitro and exposed to different concentrations of the immunomodulator lentinan. To evaluate the immunostimulating effects of lentinan, proliferation of the peripheral blood leucocytes, respiratory burst of macrophages and interleukin-1β (IL-1β) gene mRNA expression of macrophages were investigated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide], NBT (nitroblue tetrazolium) reduction, Griess reaction and real-time polymerase chain reaction (PCR). Results showed that proliferation of peripheral blood leucocytes after 24 h incubation by the induction of lentinan at 100 and 1000 μg/ml was markedly stimulated. Lentinan at 1, 100 and 1000 μg/ml could significantly induce superoxide anions in macrophages. Production of nitric oxide by HK macrophages after 96 h incubation by lentinan showed that it had no conspicuous effect on nitrogen burst activity of macrophages. Moreover, it inhibited the nitrogen burst activity at higher doses. The expression of IL-1β in the HK macrophages after 24 h of polysaccharide stimulation showed that lentinan stimulated IL-1β expression in the head kidney in carp. Lentinan can modulate the immune response of C. carpio. [ABSTRACT FROM AUTHOR]

To study the function of the GnRH protein, the recombinant pMAL-GnRH was constructed and expressed in TB1 E. coli. The cDNA encoding gonadotropin-releasing hormone (GnRH) and GnRH associated peptide (GAP) was amplified from total RNA of O. aurea pituitary glands by reverse transcription polymerase chain reaction (RT-PCR), and then blasted against other GnRH cDNA sequences in the GenBank. The analysis of the sequence data indicated that the coding region of the cDNA fragment, which encoded 89 amino acid residues, was about 400 bp in size. The amplified cDNA fragment was cloned into the prokaryotic expression vector, pMAL-c2x, to produce the expression vector pMAL-GnRH. The recombinant plasmid was transformed into E. coli TB1. GnRH-MBP fusion protein was obtained after the addition of IPTG into the growth media. SDS-PAGE analysis revealed that the GnRH-MBP was expressed after induction with IPTG for 4 h. A protein band of 56 kD appeared on SDS-PAGE gel and was proved by Western blot. The mass production of the recombinant protein was about 41.6% of total bacteria protein. After purification and cleavage of the fusion protein purified GnRH protein could be obtained. Then the fusion protein was used to immunise some ICR mice to produce anti-GnRH antibody. This fusion protein could significantly elicit specific antibody response in immunized mice compared with the blank groups, and the titers against GnRH reached peak 0.707 +/- 0.320 at the 5th week after immunization. These results demonstrated that recombinant protein could induce high GnRH antibody responses in laboratory animals.