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Various concentrations of guanylurea phosphate (GUP) were incorporated into an aqueous melamine-urea-formaldehyde (MUF) resin to synthesize a fire-retardant, translucent, and intumescent varnish. The effects of the GUP on the curing, light transmittance, and thermal stability of the resulting varnish, and combustion behavior of the varnish-coated plywood were determined by viscosimetry, Fourier-transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV–vis) spectroscopy, thermogravimetry (TG), and cone calorimetry, respectively. The results show that GUP decelerated the curing rate; the resulting varnish film was translucent and UV-absorbing. The calorimetry demonstrated that GUP did not change the thermal stability but significantly facilitated charcoal formation of the varnish. The presence of the GUP resulted in an increased intumescent thickness of the varnish and substantially suppressed and delayed the mass loss, smoke production, and heat release of the coated plywood. At 12% GUP concentration the resulting varnish film exhibited an optimal combination of translucency and fire retardancy. These findings demonstrate that the GUP can be incorporated into aqueous MUF resin for the synthesis of a clear intumescent varnish capable of fire retardancy.

Background Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) functions as a cytokine to selectively kill various cancer cells without toxicity to most normal cells. Numerous studies have demonstrated the potential use of recombinant soluble TRAIL as a cancer therapeutic agent. We have showed previous administration of a recombinant adeno-associated virus (rAAV) vector expressing soluble TRAIL results in an efficient suppression of human tumor growth in nude mice. In the present study, we introduced Tet-On gene expression system into the rAAV vector to control the soluble TRAIL expression and evaluate the efficiency of the system in cancer gene therapy. Methods Controllability of the Tet-On system was determined by luciferase activity assay, and Western blotting and enzyme-linked immunoabsorbent assay. Cell viability was determined by MTT assay. The breast cancer xenograft animal model was established and recombinant virus was administrated through tail vein injection to evaluate the tumoricidal activity. Results The expression of soluble TRAIL could be strictly controlled by the Tet-On system in both normal and cancer cells. Transduction of human cancer cell lines with rAAV-TRE-TRAIL&rAAV-Tet-On under the presence of inducer doxycycline resulted in a considerable cell death by apoptosis. Intravenous injection of the recombinant virus efficiently suppressed the growth of human breast carcinoma in nude mice when activated by doxycycline. Conclusion These data suggest that rAAV-mediated soluble TRAIL expression under the control of the Tet-On system is a promising strategy for breast cancer therapy.

In the present experiment we attempted to confirm the specific stimulation of substance P (SP) on human T lymphocyte proliferation as reported by Payan et al. and to observe its effect on human B lymphocyte proliferation. As a result, no definite mitogenic effect of SP (10−11 to 10−7 M) was found on both human T and B cells, no significant influence of SP on the blastogenic response of T cells to Con A or PHA stimulation in a wide range of concentrations and no effect on proliferative response of B cells to Staphylococcus aureus Cowen strain I stimulation were shown. Payan's conclusion was based on percentage increase of 3H-TdR incorporation. But as the background cpm is generally very low, even 100 per cent increase would only indicate a very small cpm increase, so in this situation percentage increase might give false phenomenon, and only cpm could tell whether the effect was strong or weak. Thus, we believe that is the reason for our disagreement with Payan's conclusion.

It has been reported in the literature that PWM-responsive B lymphocytes are sIgM+, sIgD-, lack receptors for mouse erythrocytes, and are larger than PWM-negative lymphocytes. This paper describes the observation of B cells among the thymocytes from a patient with myasthenia gravis. In the thymocytes, actually no sIg+ cell was found, and Staphylococcus aureus Cowen strain I could not induce the mononuclear cells in the thymus to differentiate. It was surprising that 6.9 per cent of the cells were BA-1 positive cells. At the same time, in the presence of PWM, 9680 +/- 555 cells out of 1 X 10(-6) thymocytes could be induced to differentiate to immunoglobulin-secreting cells (ISC) in culture. This result suggests that PWM might be able to induce sIg- B lymphocytes to differentiate as well.