Controlled synthesis of ultra-long AlN nanowires in different densities and in situ investigation of the physical properties of an individual AlN nanowire.

The controlled synthesis of different growth densities of ultra-long AlN nanowires has been successfully realized by nitridation of Al powders for the first time. These AlN nanowires have an average diameter of about 100 nm and their mean length is over 50 µm. All the synthesized ultra-long nanowires are pure single crystalline h-AlN structures with a growth orientation of [0001]. We preferred the self-catalyzing vapor-liquid-solid (VLS) mechanism to illustrate their growth process. Although the sample with the middle growth density (3.2×10(7) per cm2) of AlN nanowire performs the best field emission (FE) properties, the emission uniformity is not good enough for field emission display applications, which may be attributed to their low intrinsic conductivity. Moreover, the electrical transport and FE properties of an individual ultra-long AlN nanowire are further investigated in situ to find the decisive factor responsible for their FE behaviors. An individual AlN nanowire is observed to have a mean 1 nA field of 440 V µm(-1) and 1 µA field of 480 V µm(-1) as well as an average electrical conductivity of about 2.7×10(-4)Ω(-1) cm(-1), which is lower than that of some cathode materials with excellent FE properties. Therefore we come to the conclusion that the electrical conductivity of the AlN nanowire must be improved to a higher level by some effective ways in order to realize their practical FE device applications.

Reversal of P-glycoprotein and multidrug-resistance protein-mediated drug resistance in KB cells by 5-O-benzoylated taxinine K.

A newly synthesized taxoid originally from the Japanese yew Taxus cuspidata, 5-O-benzoylated taxinine K (BTK) was examined for its ability to reverse P-glycoprotein (P-gp) and multidrug resistance protein (MRP)-mediated multidrug resistance. BTK reversed the resistance to paclitaxel, doxorubicin (ADM), and vincristine (VCR) of KB-8-5 and KB-C2 cells that overexpress P-gp by directly interacting with P-gp. BTK also moderately reversed the resistance to ADM of KB/MRP cells that overexpress MRP. However, BTK neither inhibited the transporting activity of MRP nor reduced intracellular glutathione levels in KB/MRP cells. BTK shifted the distribution of ADM in KB/MRP cells from punctate cytoplasmic compartments to the nucleoplasm and cytoplasm by inhibiting acidification of cytoplasmic organelles. These two functions of BTK make it able to reverse both P-gp- and MRP-mediated MDR. BTK in combination with ADM should be useful for treating patients with tumors that overexpress both P-gp and MRP.

Enhanced transport of anticancer agents and leukotriene C4 by the human canalicular multispecific organic anion transporter (cMOAT/MRP2).

We established stable human canalicular multispecific organic anion transporter (cMOAT/MRP2) cDNA transfectants, CHO/cMOAT from non-polarized Chinese hamster ovary (CHO)-K1 and LLC/cMOAT from polarized pig kidney epithelial LLC-PK1. Human cMOAT was mainly localized in the plasma membrane of CHO/cMOAT and in the apical membrane of LLC/cMOAT. The ATP-dependent uptake of leukotriene C4 (LTC4) into CHO/cMOAT membrane vesicles was enhanced compared with empty vector transfectants. Km values in CHO/cMOAT membrane vesicles were 0.24 microM for LTC4 and 175 microM for ATP. Drug sensitivity to vincristine and cisplatin in human cMOAT cDNA transfectants decreased, but not to etoposide. Cellular accumulation of vincristine and cisplatin in human cMOAT cDNA transfectants decreased, but not of etoposide. The uptake of LTC4 into CHO/cMOAT membrane vesicles was inhibited by exogenous administration of vincristine or cisplatin, but not that of etoposide. Moreover, this inhibition was more enhanced in the presence of glutathione. These consequences indicate that drug resistance to vincristine or cisplatin appears to be modulated by human cMOAT through transport of the agents, possibly in direct or indirect association with glutathione.

An active efflux system for heavy metals in cisplatin-resistant human KB carcinoma cells.

The mechanism for cisplatin resistance in cisplatin-resistant KCP-4 cells was studied. Although multidrug resistance-associated protein (MRP) was not detected in KCP-4 cells, the cells were more resistant to heavy metals than multidrug-resistant C-A120 cells that overexpressed MRP. KCP-4 cells expressed metallothionein, but it was scarcely involved in cisplatin resistance in these cells. KCP-4 cells did not express canalicular multispecific organic anion transporter (cMOAT). The glutathione (GSH) level was 4.7-fold higher in KCP-4 cells than in KB-3-1 cells. When the GSH level in KCP-4 cells was decreased by treating the cells with buthionine sulfoximine and nitrofurantoin, the accumulation of and sensitivity to cisplatin in the cells were increased. C-A120 cells were only 3.0-fold more resistant to cisplatin than KB-3-1 cells and this resistance was not affected by the increased glutathione level. The accumulation of platinum in C-A120 and KCP-4 cells was 68.5 and 20.4% of that in KB-3-1 cells, respectively, while the intracellular levels of antimony potassium tartrate in C-A120 and KCP-4 cells were 13.2 and 9.9% of that in KB-3-1 cells, respectively. The ATP-dependent efflux of antimony was enhanced in both C-A120 and KCP-4 cells. These results, taken together, suggest an efflux pump for heavy metals different from MRP and cMOAT is involved in cisplatin resistance in KCP-4 cells.

[Electron microscopic observation on cysticercus cellulosae treated with mienangling in vitro].

OBJECTIVE: To observe the effect of Mienangling (MNL) in treating cysticercus cellulosae in vitro. METHODS: The changes of cysticercus cellulosae treated in vitro with the MNL extracts, praziquantel (PQT) and albendazole (ALB) were studied under the transmission and scanning electron microscopes. RESULTS: Under the scanning electron microscope, the authors can see that all of the cysticercus's scoleces did not grow in the MNL and PQT groups, cyst walls shrivelled, tegument's ectoplasts were damaged, microtriches's ultrastructures were not clear or exfoliated, some corpuscular matter densely was distributed in the surface; 46.7% of cysticercus cellulosaes in the ALB group had been excystated, the rostellar hooks of rostella developed normally, four sucker's surface wrer hollow, the necks were eroded, and grooves of sonite disappeared. Under the transmission electron microscope, we can see that the tegument, basement membrane, muscular layer and parenchyma in the groups of MNL and PQT were all clearly damaged, but the harmful effect of MNL to parenchyma's nerve cords is more serious than the PQT. The damage of all layers of the cysticercus cellulosae in the ALB group is smaller in degree than the MNL and the PQT. CONCLUSION: The MNL has marked damaging effect to cysticercus cellulosae.

[Clinical study in treating intractable ulcerative colitis with traditional Chinese medicine].

UNLABELLED: Clinical double blind study in treating 153 intractable ulcerative colitis with Chinese medicinal herbs was conducted, the patients were randomly assigned to three groups. Group I is administered with Jian Pi Ling (JPL) tablet with retention-enema of Radix Sophorae Flavescentis and Flos Sophora (RSF-FS) decoction per night, group II with salicylazosulfapyridine (SASP) and retention-enema of dexamethasone, group III with placebo and retention-enema of decoction as that in group I. After 90 days every patients were checked by means of fibro-enteroscope, pathologic and immunologic parameters. THE RESULTS: the curative rates of group I, II, III, were 53.1%, 27.7% and 19.0%, the total effective rates were 85.9%, 59.6% and 45.2% respectively. By comparison among groups, the efficacy of group I was the best (P < 0.01). The check of T and B lymphocyte subpopulation showed the B lymphocyte of group I markedly decreased, OKT3 and OKT8 obviously increased, the ratio of OKT4 and OKT8 approached normal value. The amount of IgG, IgM, C3 increased abnormally, decreased dramatically after medication, while those of group II and III have not changed significantly. The bacteriostatic test in vitro showed the bacteriostatic effect of RSF-FS on pathogenic B. coli, Shigella dysenteriae and Staphylococcus aureus was the best, that of solution Jian Pi Ling the next, that of SASP was the least effective. Therefore, the principle and method of group I seems to be the best therapeutic programme.

[Duplication of animal model of ulcerative colitis and studies on rehabilitation effect of jianpiling prescription].

In this paper, the ulcerative colitis model of rats with immuno-method was reported and the mechanism of using Jianpiling for the treatment of ulcerative colitis was studied. The rats of experimental group were subdivided into 3 subgroups (A, B and C), 15% Jianpiling suspension was given to rats in subgroup A per os, 15% Bupi-Yichang Pill to rats in subgroup B per os, 4.5% SASP suspension to rats in subgroup C, and same amount of saline to rats in the control group. The therapeutic results showed that the anti-diarrhia, anti-infection and repairing function of tissue by Jianpiling were obviously better than those of Bupi-Yichang Pill and SASP. Serological exams also showed that Jianpiling was much better than other therapeutic groups in increasing nonspecific cellular immunity and lowering level of antibody against large intestine and IgG. These results suggested that the mechanism of Jianpiling on ulcerative colitis was realized by increasing cellular immunity, inhibiting humoral immunity and promoting immune modulation.

[Clinical observation and experimental study on the treatment of diarrhea due to spleen deficiency with jianpiling].

The clinical and experimental results of Jianpiling for treating diarrhea due to Spleen deficiency were reported in this paper. 268 cases in the treatment group were treated with Jianpiling, 8 tablets three times daily for a consecutive period of 40-60 days. The curative rate and the total effective rate were 63.4% and 98.5% respectively. 75 cases in the control group were treated with SASP or Diphenoxylatum Co., the curative rate and the total effective rate being 38.7% and 94.7% respectively. The difference of the curative rate between the two groups was statistically significant (P less than 0.001). The excretory rate of D-xylose demonstrated that Jianpiling could increase the resorptive function of small intestine. The experiment on isolated small intestine of rabbits showed that Jianpiling could strikingly inhibit the peristalsis of isolated jejunum and ileum. The effect of relieving spasm of the intestine and alleviating pain was taken by antagonising the exictative function of M-receptor for acetylcholine and directly inhibiting the intestinal smooth muscle.