[Study on the role of superoxide anion in promoting proliferation and transformation of rat liver oval cell line WB-E344]

OBJECTIVE

To study the role of superoxide anion (O2.-) in promoting proliferation and transformation of rat liver oval cell strain WB-F344.

METHODS

WB-F344 cells cultured were stimulated directly by O2.- generated by interaction of xanthine with xanthine oxidase (X-XO). The effect of O2.- in promoting proliferation of WB cells was investigated by using MTT colorimetric analysis, 3H-Tdr incorporation liquid scintillation counter and 3H-Tdr incorporation autoradiography. WB cells initiated with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) were promoted by stimulating continuously with O2.- of low concentration (X: 100 mumol/L, XO: 0.2 mU/ml). The transformation effect was tested by morphologic observation, karyotype analysis and anchorage-independent growth assay.

RESULTS

Proliferation of WB cells was induced obviously by O2.- of low concentration for only one time. WB cells initiated with MNNG were transformed by action with O2.- of low concentration continuously for 15 d and typical morphologic character of transformed cells was observed. In karyotype analysis the cells chromosome number changed and the frequency of structure aberration raised dramatically. Also the transformed cells could form clone on self-solid culture medium.

CONCLUSIONS

The biological effect of O2.- was related closely with its dose; The effects of low concentration in promoting proliferation and transformation of liver oval cells indicate its important role in hepatocarcinogenesis and antioxidation was able to provide a new clue in prevention and cure of hepatoma.

Small-angle x-ray scattering study of kinetics of spinodal decomposition in N-isopropylacrylamide gels

We present synchrotron-based time-resolved small-angle x-ray scattering (SAXS) measurements of spinodal decomposition in a covalently cross-linked N-isopropylacrylamide gel. The range of wave numbers examined is well beyond the position of the maximum in the structure factor S(q,t). The equilibrium structure factor is described by the sum of a Lorentzian and a Gaussian. Following a temperature jump into the two phase region, the scattered intensity increases with time and eventually saturates. For early times the linear Cahn-Hilliard-Cook (CHC) theory can be used to describe the time evolution of the scattered intensity. From this analysis we found that the growth rate R(q) is linearly dependent on q(2), in agreement with mean-field theoretical predictions. However the Onsager transport coefficient Lambda(q) approximately q(-4), which is stronger than the q dependence predicted by the mean-field theory. We found that the growth rate R(q)>0, even though the wave numbers q probed by SAXS are greater than sqrt[2]q(m) where q(m) is the position of the peak of S(q,t), also in agreement with the mean-field predictions for a deep quench. We have also examined the range of validity of the linear CHC theory, and found that its breakdown occurs earlier at higher wave numbers. At later times, a pinning of the structure was observed. The relaxation to a final, microphase-separated morphology is faster and occurs earlier at the highest wave numbers, which probe length scales comparable to the average distance between crosslinks.

[Study on the pharmacokinetics of the liver targeted mitoxantrone polylactic acid extended-release nanoparticles in rabbits]

HPLC was used to analyse the drug concentrations in blood. The 3p87 (practical pharmacokinetic program-version) was used to calculate the parameters of DHAQ-PLA-NP lyophilization injection and DHAQ injection through i.v. administration in rabbit blood. The concentration-time curves of the two kinds of preparations were in keeping with the three-compartment model. The drug concentrations were calculated according to the selecting pharmaceutical model and parameters. The calculated drug concentrations agreed well with the observed. The lyophilization injection sustained the eliminating process in vivo.

[The in vitro release kinetics of Daunorubicin polybutylcyanoacrylate nanoparticles]

The in vitro release kinetics of Daunorubicin Polybutylcyanoacrylate Nanoparticles(DNR-PBCA-NP) was studied by dynamic dialysis system. The concentration of Daunorubicin was determined by spectrophotometry. The result showed the in vitro release kinetics of DNR-PBCA-NP could be well characterized by a biexponential equation. There were two phases in the process of drug release. The initial phase was a fast release phase (the burst effect). The second phase was a slow release phase.

Detyrosination of tubulin regulates the interaction of intermediate filaments with microtubules in vivo via a kinesin-dependent mechanism

Posttranslationally modified forms of tubulin accumulate in the subset of stabilized microtubules (MTs) in cells but are not themselves involved in generating MT stability. We showed previously that stabilized, detyrosinated (Glu) MTs function to localize vimentin intermediate filaments (IFs) in fibroblasts. To determine whether tubulin detyrosination or MT stability is the critical element in the preferential association of IFs with Glu MTs, we microinjected nonpolymerizable Glu tubulin into cells. If detyrosination is critical, then soluble Glu tubulin should be a competitive inhibitor of the IF-MT interaction. Before microinjection, Glu tubulin was rendered nonpolymerizable and nontyrosinatable by treatment with iodoacetamide (IAA). Microinjected IAA-Glu tubulin disrupted the interaction of IFs with MTs, as assayed by the collapse of IFs to a perinuclear location, and had no detectable effect on the array of Glu or tyrosinated MTs in cells. Conversely, neither IAA-tyrosinated tubulin nor untreated Glu tubulin, which assembled into MTs, caused collapse of IFs when microinjected. The epitope on Glu tubulin responsible for interfering with the Glu MT-IF interaction was mapped by microinjecting tubulin fragments of alpha-tubulin. The 14-kDa C-terminal fragment of Glu tubulin (alpha-C Glu) induced IF collapse, whereas the 36-kDa N-terminal fragment of alpha-tubulin did not alter the IF array. The epitope required more than the detyrosination site at the C terminus, because a short peptide (a 7-mer) mimicking the C terminus of Glu tubulin did not disrupt the IF distribution. We previously showed that kinesin may mediate the interaction of Glu MTs and IFs. In this study we found that kinesin binding to MTs in vitro was inhibited by the same reagents (i.e., IAA-Glu tubulin and alpha-C Glu) that disrupted the IF-Glu MT interaction in vivo. These results demonstrate for the first time that tubulin detyrosination functions as a signal for the recruitment of IFs to MTs via a mechanism that is likely to involve kinesin.

[Inhibition effects of tumor infiltrating lymphocytes from oral cancer on nude mice transplanted tumor established with human tongue carcinoma cell lines]

OBJECTIVE

To observe the in vivo inhibition effects on nude mice transplanted tumor with tumor infiltrating lymphocytes (TILs) isolated from primary mass of oral cancer.

METHODS

Established the transplanted tumor model of human tongue cancer at the back of BALB/C nude mice with subcutaneous injection of squamous cell carcinoma lines Tca 8113. TILs isolated from patients with Oral cancer, combining with low dose of cyclophosphamide (Cy: 50 mg/kg), were locally injected into the peripheral site of tumor. The inhibition rate (IR) was calculated by the volume of tumor mass from the 1st to the 8th week, and the weights at the 8th week after tumor dissection.

RESULTS

1. Group TIL + rIL-2 and group TIL + rIL-2 + Cy both exerted a strong inhibition effect on the transplanted tumor within three weeks. The Inhibition rate (IR) were 86.1% +/- 0.4% and 97.7% +/- 0.6% respectively at the 3rd week, while 32.1% +/- 0.3% and 80.6% +/- 0.3% at the 8th week. 2. TIL + rIL-2 + Cy expressed a stronger effect and a longer inhibition time. The IR of TIL + rIL-2 and TIL + rIL-2 + Cy were 20.0% +/- 1.4% and 75.5% +/- 2.5% respeetively at the 8th week (P < 0.01).

CONCLUSION

This study demonstrated that TILs from patients with oral carcer possess strong in vivo inhibition on nude mice transplanted tumor, and low dose of cyclophasophamide can enhance the inhibition effect and prolong the inhibition time.

Kinesin is a candidate for cross-bridging microtubules and intermediate filaments. Selective binding of kinesin to detyrosinated tubulin and vimentin

We showed previously that stable, detyrosinated (Glu) microtubules function to localize vimentin intermediate filaments in fibroblasts (Gurland, G., and Gundersen, G. G. (1995) J. Cell Biol. 131, 1275-1290). To identify candidate proteins that mediate the Glu microtubule-vimentin interaction, we incubated microtubules with microtubule-interacting proteins and saturating levels of antibodies to Glu or tyrosinated (Tyr) tubulin. Antibodies to Glu tubulin prevented the microtubule binding of kinesin obtained from fibroblast or brain extracts more effectively than antibodies to Tyr tubulin. Scatchard plot analysis showed that kinesin heads bound to Glu microtubules with an approximately 2.8-fold higher affinity than to Tyr microtubules. Purified brain kinesin cosedimented with vimentin, but not with neurofilaments, indicating that kinesin specifically associates with vimentin without accessory molecules. Kinesin binding to vimentin was not sensitive to ATP, and kinesin heads failed to bind to vimentin. By SDS-polyacrylamide gel electrophoresis, a kinesin heavy chain of approximately 120 kDa and a light chain of approximately 64 kDa were detected in vimentin/kinesin pellets. The light chain reacted with a general kinesin light chain antibody, but not with two other antibodies that recognize the two known isoforms of kinesin light chain in brain, suggesting that the kinesin involved in binding to vimentin may be a specific one. These results demonstrate a kinesin-based mechanism for the preferential interaction of vimentin with detyrosinated microtubules.

[Relationship between oval cells and preneoplastic lesions induced by 2-acetylaminofluorene in rat liver]

OBJECTIVE

To study the cellular origin of preneoplastic lesion of liver induced by the 2-acetylaminofluorene (2-AAF) in rat.

METHODS

Male fisher 344 rats were used for two different carcinogenesis models. Model 1: Rats were fed with regular diet containing 0.02% 2-AAF for totally 28 days, and subjected to a standard two thirds partial hepatectomy (2/3 PH) on the 7th day in order to stimulate the proliferation of oval cells. 3H thymidine (3H-Tdr) was administered intraperitoneally on the 12th day for selective labelling of oval cells. Model II: Rats were subjected to 2/3 PH and 3H-Tdr was administered intraperitoneally 22 hours after the operation for the selective labelling of hepatocytes. The rats were then fed with 2-AAF for totally 28 days after a 9 days recovery period from 2/3 PH. The relationship between preneoplastic lesion and selectively labelled oval cells, or hepatocytes, was traced by autoradiography.

RESULTS

Pathological examination and autoradiography denoted that the silver grains (labelled signals) were only formed in the preneoplastic cells in model I rather than the cells of model II animals.

CONCLUSION

It is a direct evidence to demonstrate that the preneoplastic cells are mostly originated from the oval cells.

[Reliability design and analysis of man-machine performance of display and illumination system in cockpit]

This paper analysed and discussed the basic reliability of display and illumination system in which Chinese characters displayed on LCD were read and the colours were identified, and instruments in different visual views and the instruments of differential display models were read. The colour rendering of the light source was also evaluated. Basic reliability may be chosen as 0.9995.

Significance of proliferating cell nuclear antigen expression in liver metastasis of colorectal cancer

PURPOSE

The study contained herein was aimed at finding some possible pathologic factors that have significance for the prediction of liver metastasis in colorectal cancer.

METHOD

Resected specimens of colorectal cancer from 23 patients with liver metastasis and 30 patients without liver metastasis were subjected to pathologic study, including microscopic characteristics and proliferating cell nuclear antigen immunohistochemistry assay.

RESULTS

Strongly positive expression of proliferating cell nuclear antigen was present in 65.21 percent (15/23) of the liver metastasis group, whereas it was found in only 20 percent (6/30) of the group without liver metastasis (P < 0.005). Deeper invasion to the muscularis propria or serosa and less infiltration of lymphocytes surrounding the tumor were more frequently found in the liver metastasis group than in the other group (P < 0.025).

CONCLUSION

Extent of proliferating cell nuclear antigen expression, depth of invasion, and reaction of lymphocyte infiltration of the primary tumor could have predictive significance of colorectal cancer in liver metastasis.

[Contents of free amino acids and water-soluble carbohydrates in Curcuma longa L. at different stages of growth]

Closely related to the development of plant organs, the contents of free amino acids and water-soluble carbohydrates in Curcuma longa vary with the course of growth. The ratio of the two contents rises with the growing periods, and reaches a maximum in the later stages of growth.

[Ontogeny of Curcuma longa L]

Based on the research of growth of organs, accumulation of dry matter, distribution of photosynthetic production and displacement of growth centre, the growth of turmeric can be divided into three stages. There are 13 leaves in the life of turmeric. Leaf formation takes place rapidly to form 8 leaves in the seedling stage. The leaf area and increase of dry matter per day in roots and leaves are smaller or lower in the seedling stage. In the daughter rhizome formation stage, NAR reaches the maximum (3.54/m2.d), and the leaf area reaches the maximum(3302.9 cm2/plant, LAI 4.95). Before the daughter rhizome formation stage, more than 75% of dry matters are distributed in leaves, and in the daughter rhizome formation stage, 50%-75% of dry matters are distrbuted in leaves. In the late growing period, more than 40% of dry matters are distributed in the daughter rhizome. The growth centre of turmeric changes two times in life. When CGRr is equal to CGRt, the crossing of CGRt and CGRr curves may be regarded as the evidence of the transfer of growth centre from leaves to daughter rhizome.

Kinesin- and myosin-driven steps of vesicle recruitment for Ca2+-regulated exocytosis

Kinesin and myosin have been proposed to transport intracellular organelles and vesicles to the cell periphery in several cell systems. However, there has been little direct observation of the role of these motor proteins in the delivery of vesicles during regulated exocytosis in intact cells. Using a confocal microscope, we triggered local bursts of Ca2+-regulated exocytosis by wounding the cell membrane and visualized the resulting individual exocytotic events in real time. Different temporal phases of the exocytosis burst were distinguished by their sensitivities to reagents targeting different motor proteins. The function blocking antikinesin antibody SUK4 as well as the stalk-tail fragment of kinesin heavy chain specifically inhibited a slow phase, while butanedione monoxime, a myosin ATPase inhibitor, inhibited both the slow and fast phases. The blockage of Ca2+/calmodulin-dependent protein kinase II with autoinhibitory peptide also inhibited the slow and fast phases, consistent with disruption of a myosin-actin- dependent step of vesicle recruitment. Membrane resealing after wounding was also inhibited by these reagents. Our direct observations provide evidence that in intact living cells, kinesin and myosin motors may mediate two sequential transport steps that recruit vesicles to the release sites of Ca2+-regulated exocytosis, although the identity of the responsible myosin isoform is not yet known. They also indicate the existence of three semistable vesicular pools along this regulated membrane trafficking pathway. In addition, our results provide in vivo evidence for the cargo-binding function of the kinesin heavy chain tail domain.

[Dynamic distribution in vivo of TIL from human tongue cancer after local injection in animal model]

On the basis of established nude mice transplanted tumor model of human tongue squamous cell carcinoma, peritumor injection was performed with 3H-TdR labeled TIL from human tongue cancer after 4 weeks culture. The dynamic distribution of 3H-TIL in vivo was learned through detecting the radioactivity of the target tissues. The results demonstrated that 3H-TIL was found in the whole body. There were about 2.1-30 times more in tumor tissues than in normal tissues and 3H-TILs even collected in the tumor tissues distal to the injective sites. The nearer to the injective sites the tumor tissues, the more 3H-TIL collected. It showed that local injection of TIL could be expected to exert a better antitumor effect.

[Antitumor effect of TIL combined with radiotherapy on mouse uterocervical cancer U14]

After yielding culturing mouse TIL from U14 with Rosenberg's technique, the authors observed the antitumor effect of TIL combined with radiotherapy on established mouse transplanted tumor of uterocervical cancer U14. The results demonstrated TIL treatment or radiotherapy could inhibit the tumors growth. Combination showed a stronger inhibition and the E/O value was 1.1. It implied that an additive effect was gotten when combining TIL with radiotherapy.

[Optimal high-yield agronomic measures for Curcuma longa L]

Regression method of orthogonal conic substitution with factors was employed to build up a tuber yield simulation model. Three main measures (sowing time, plant population, application rate of fertilizer) affecting the tuber yield were analyzed by the mathematical model of three unknown second order orthogonal rotative regression. The optimal agronomic measures were obtained. The results indicate that sowing time and plant population play a important role in raising the tuber yield. Sowing time is clearly interrelated with plant population, and likewise, plant population application rate of fertilizer.

[The electricity properties of polybutylcyanoacrylate nanoparticles]

Electricity properties of polybutylcyanoacrylate nanoparticles (PBCA-NP) were studied by using a U-tube electrophoresis apparatus. It was proved that all the PBCA-NP is negatively charged. The surface potential of PBCA-NP is directly proportional to the concentration of stabilizer (Dextran 70) and the pH value of the medium, while it is inversely proportional to the concentration of butylcyanoacrylate and the model drug (gentamycin). The effect of ion strength on surface potential is obvious but not linear. The effect of stabilizers and surfactants used on the surface potential is evident while the effect of electrolytes is indistinct under the experimental conditions.

[Reasonability of extracting procedures for huiyangfanben decoction]

The reasonability of extracting procedures for traditional Chinese prescriptions was studied with Huiyangfanben Decoction as sample. The comparative results of the ingredients in extractions prepared by different procedures revealed. For the prescriptions with complicated ingredients, more attention should be paid to the ingredients and their characteristics when designing the extracting procedurs, and in extraction the drugs should be classified according to the interaction of the ingredients. More extracting solvents could be used according to the characteristics of the active ingredients.

[Curcuma longa L. tuber yield simulation model and its application under combined agronomic measures for good-quality, high-yield and obvious economic results]

A design of second order orthogonal rotative regression was developed and field tested, and the tuber models for yield, quality and benefit were simulated and built. The effect of agronomic measures on the tuber yield is plant density > phosphorus > sowing date > nitrogen > potassium. There is a clear interrelation effect among agronomic measures. The results of simulation experiment have shown that the optimal combination of farming practices can greatly increase the tuber yield, quality and benefit, and is adjusted according to climate, soil, ferilizer or manure sources, and so on.

[Rules of the absorption, distribution and translocation of nitrogen, phosphorus and potassium in turmeric plant]

It has been found out that the percentages of nitrogen (N), phosphorus (P) and potassium (K) in turmeric plant (Curcuma longa) are higher in young organs. Varying with the growth stages, the nutrient contents of the plant, whose amount order is K > N > P are the highest in the seedling stage. Nutrient absorption occurs mainly in the young turmeric forming stage and enriching stage. Nutrient translocation takes place mainly from leaves and leaf stalks to young and old turmeric, the rate of P being the highest.

[Study on changes of visual fatigue index during prolonged visual display terminal operation]

25 Arabic numerals (0-9) lined in a row were displayed with 4 different patterns on CRT. The subjects were asked to find out the one missed numeral in the row and to press the key corresponding to the numeral. The work lasted for 3h. Longitudino-Kinetic visual acuity was measured before and at 30, 60, 80, 100, 120, 150, 180 minutes during the work. The results showed that the Longitudino-Kinetic visual acuity dropped with working time and recovered after work quickly at first and then slowly.

Low concentrations of nocodazole interfere with fibroblast locomotion without significantly affecting microtubule level: implications for the role of dynamic microtubules in cell locomotion

The role of microtubules (MTs) in cell locomotion is uncertain: while MTs are not essential for motility of certain cells, MTs are necessary for the directed translocation of large cells such as fibroblasts, endothelial cells and neuronal growth cones. Based on previous studies, we hypothesize that cell locomotion may involve MTs in two possible ways: (1) the rate of cell locomotion is proportional to MT level; or (2) cell locomotion is not proportional to MT level but requires a critical level of MTs to proceed. To test these hypotheses, we measured the rate of locomotion of NRK fibroblasts migrating into an in vitro wound, before and after treatment with different concentrations of nocodazole to generate cells with different levels of MTs. Locomotion of cells was monitored directly using timelapse recording and analyzed with an Image-1 image analysis program. Addition of nocodazole (&gt; or = 50 nM) resulted in a rapid reduction in locomotion to a new rate that was maintained for &gt; 2 hours. We found that addition of as little as 100 nM nocodazole decreased the rate of locomotion by more than 60%; and that 300 nM nocodazole completely stopped cell locomotion. Although 100 nM nocodazole decreased locomotion over 60%, we detected no qualitative change in MT distribution by immunofluorescence. Quantitative analysis of MT fluorescence in immunofluorescently stained preparations showed that 100 nM nocodazole had no detectable effect on MT levels and that 300 nM nocodazole only decreased MT levels to approximately 40% of controls. Quantitative analysis of tubulin polymer levels by cell extraction and western blotting yielded results similar to those obtained by quantification of MT fluorescence. A comparison of the locomotion rate measurements with the MT level measurements indicated that over half of the cell locomotion rate could be blocked by nocodazole without significantly affecting MT levels in the cell; the remaining locomotion rate was reduced proportionally to MT levels. These results do not support the notion that a critical level of MTs is required for cell locomotion and suggest that only a portion (&lt; 50%) of the speed of the cells is proportional to MT levels. Rather, by analogy with studies of MT antagonists on the mitotic spindle, they suggest a third possibility: that low concentrations of nocodazole interfere with MT dynamics and thus, MT dynamics are critical for the maximal speed of cell locomotion. This notion was further supported by analogous effects of taxol and vinblastine on cell locomotion: at concentrations that reportedly cause little change in the level of MTs, taxol and vinblastine also dramatically decreased the rate of locomotion of NRK cells. In summary, our results establish the relationship between microtubule levels and locomotion rate and suggest that dynamic MTs are rate-limiting for fibroblast locomotion.

[Adsorption of aclacinomycin A onto polyisobutylcyanoacrylate nanoparticles]

The mechanism of adsorption of aclacinomycin A onto polyisobutylcyanoacrylate nanoparticle and the factors effecting the adsorption were studied. The adsorption process reached equilibrium in 15 minutes. The results showed that the surface charge densities of the nanoparticles, pH, ionic strength and temperature effected the adsorption. Adsorption isotherms of aclacinomycin A onto polyisobutylcyanoacrylate nanoparticles could be described with Freundlich equation Y = 1.0188 C0.6494 (r = 0.9945) and with Langmuir equation C/Y = 0.7363C + 0.4027 (r = 0.9331) respectively. The main actions between aclacinomycine A and polyisobutylcyanoacrylate nanoparticles were electrostatic and ionic action.

[Physicochemical characteristics of gentamicin polybutylcyanoacrylate nanoparticles]

Several formulations of gentamicin nanoparticle (GM-NP) colloids were prepared by the emulsion polymerization technique using the polybutylcyanoacrylate as the carrier. Various kinds of physicochemical characteristics, such as particle size and size distribution, drug loading and associating ratio, surface zeta potential, surface tension, turbidity, relative density, viscosity, refractive index and acidity were observed, determinated and compared. The results of the experiments have contributed to a full understanding of the physicochemical characteristics of gentamicin nanoparticles and also provided a basis for the establishment of the quality evaluation methods.

[Comparative study on baicalin contents in 4 traditional Chinese medicinal preparations of ying huang]

The contents of baicalin in four different traditional Chinese medicinal preparations of Ying Huang were determined by HPLC. The contents of baicalin in Ying Huang tablets, Ying Huang oral liquid, Ying Huang injection and Ying Huang granules are respectively: 124.18 mg/g, 21.12 mg/ml, 12.39 mg/ml and 6.79 mg/g. The HPLC method suggested in this paper can be used for quality control in the production of Ying Huang preparations.

[Acute toxicity of liver targeting mitoxantrone-nanospheres]

The experimental result of acute toxicity of liver targeted drug delivery system-mitoxantrone-polybutylcyanoacrylate-nanospheres (DHAQ-PBCA-NS) in mice is reported. The results showed that the acute toxicity of DHAQ-PBCA-NS i.v. in mice was lower than that of DHAQ (LD50 = 16.9 +/- 3.9 mg/kg). The cells of the heart, liver, spleen, kidney and lung had no pathological change. It has been shown that mitoxantrone-nanospheres have some value of application.

[Determination of ursodeoxycholic acid and chenodeoxycholic acid in Chinese medicinal compound preparations by TLC-densitometry]

The contents of ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) in Chinese medicinal compound preparations have been determined by TLC-densitometry. The determination wavelength was 375nm and reference wavelength was 700nm. For UDCA the linear range was 3.0-15.0 micrograms and recovery was 97.2% (RSD = 1.2%), and for CDCA the linear range was 4.0-20.0 micrograms and recovery was 99.3% (RSD = 2.1%).

Cloned primed lymphocyte test cells recognize the fourth, fifth, and sixth hypervariable regions at amino acid positions 65-87 of the DPB1 molecule

Genetic polymorphisms of the HLA-DPB1 gene in Japanese and Caucasian panel cells defined by PLT were analyzed by the PCR-based genotyping technique PCR-RFLP, and suballeles of DPw3 (DPB1*03) and DP"Cp63" (DPB1*09) could be detected. PLT-defined DPw3 cells were typed by PCR-RFLP as either DPB1*0301 or DPB1*1401. On the other hand, PLT-defined DPCp63-typed cells were typed as DPB1*0901 or DPB1*1001. These results indicate that both DPw3 and DPCp63 are split into two subantigens. DPw2 and DPw4 are DPB1*0201 and 0202 and DPB1*0401 and 0402, respectively. Comparative analysis of the amino acid sequences of the DPw2-, DPw4-, DPw3-, and DPCp63-associated alleles revealed that the fourth (C), fifth (D), and sixth (E) hypervariable regions at amino acid positions 65-87 were shared within the same PLT-defined DP antigen groups, suggesting that these three hypervariable regions are recognized by cloned T cells in PLT, thus determining DP antigen specificity. On the basis of this model, 44 DPB1 alleles can be classified into 18 antigen groups, each of which may possibly represent a PLT-defined single DP specificity.

Isolated plasma membranes induce the loss of oriented detyrosinated microtubules and other contact inhibition-like responses in migrating NRK cells

We have previously shown that detyrosinated microtubules (Glu MTs), which are oriented toward the direction of locomotion in motile fibroblasts, disappear from the area adjacent to cell-cell contact soon after a cell-cell collision. To identify cell surface molecules that trigger this phenomenon, we have established a system in which this and other cellular reactions to cell-cell contact can be reproduced by the addition of isolated plasma membranes. Experimental wounds were made in confluent monolayers of NRK cells, and cells at the wound margin were allowed to develop oriented Glu MTs. Test samples were added to these cells and after a 1 hour incubation the distributions of Glu MTs, tyrosinated MTs (Tyr MTs) and microfilaments were determined by immunofluorescence. When plasma membranes isolated from NRK cells were added, oriented Glu MTs disappeared from the leading lamella of target cells and instead a small number of Glu MTs were found clustered around the nucleus. As observed for cell-cell contact, plasma membranes did not significantly affect the distribution of Tyr MTs. We also found that both cell-cell contact and membrane treatment caused the collapse of lamellipodia and loss of associated staining with antiactin antibody. Time-lapse recordings of directed locomotion of NRK cells showed that membranes suppressed the forward movement of cells. The loss of Glu MTs from the leading lamella was the most amenable response for quantification and we used it to examine the biochemical properties of the membrane activity. The ability of membranes to induce the loss of oriented Glu MTs was observed at as low as 4 micrograms/ml of membrane protein and was detectable 10 minutes after membrane addition. The loss of oriented Glu MTs was reversible upon removal of membranes, demonstrating that the membranes were not toxic to the cells. The oriented Glu MT reducing activity could be solubilized from the membranes by detergent, was enriched in a plasma membrane fraction, and was labile to heat and acid treatment. In summary, we have successfully reconstituted a number of responses of contact inhibition using solubilized preparations of membranes. Our preliminary results suggest that there is a specific factor in plasma membranes that is capable of triggering contact inhibition. With the assay we have developed, it should now be possible to dissect contact inhibition of motility at the molecular level.

[The distribution and pharmacokinetics in lung of bovine serum albumin microspheres for pulmonary targeting in mice]

125I-labeled bovine serum albumin microspheres loaded cisplatinum (CDDP-125I-BSA-MS) with the size range of 7-25 microns were prepared and injected into the tail vein of mice. The results showed that the microspheres were accumulated almost entirely in the lung after i.v. injection (about 97.52% injected dose at the highest concentration). While in blood and other organs almost no accumulation was found. Photomicrographs showed that microspheres reached the lung and lodged in precapillary arteriols and capillaries of lung. The microspheres in lung were eliminated gradually. The pharmacokinetics of microspheres in lung of mice was also studied with "practical pharmacokinetic program-version 87", and was fitted by two-compartment model with i.v. injection or one-compartment model with 1st order absorption, but the meaning of some parameters changed. Based on the analysis of the models and parameters, it was concluded that the pharmacokinetics of microspheres in lungs can be described by the model of "one-compartment of first-order intake and first-order elimination".

[Investigation of drug release in vitro from mitoxantrone-nanospheres]

We observed the rules of drug release in vitro from a liver targeting preparation-mitoxantrone polybutylcyanoacrylate nanospheres freeze-drying injection by dynamic penetration system and spectrophotometry. The results showed that the drug release of this nanospheres preparation accorded with the two phases kinetics rules in vitro. In the process of drug release, there were two phases. The first phase was a quick release phase, the quantity of released drug within 4 hours being more than 40%, t1/2 alpha = 1.40h. The second phase was a slow release phase, t1/2 beta = 169.02h. The rules of drug release accord with the normal rules of drug use. The preparation may be clinically used.

Temporal down-regulation of Fc gamma RIII expression and Fc gamma receptor-mediated phagocytosis in human monocyte-derived macrophages induced by TNF-alpha and IL-1 beta

Effects of tumor necrosis factor (TNF-alpha) and interleukin-1 beta (IL-1 beta) on the expression of Fc gamma receptors (Fc gamma Rs) and on Fc gamma R-mediated phagocytosis in human monocyte-derived macrophages (MDMs) have been determined. Treatment of MDMs with TNF-alpha (400 pg/ml) or IL-1 beta (400 pg/ml) for 80 min decreased cell surface Fc gamma RIII expression, as measured by flow cytometry (FACS), while the levels of surface Fc gamma RI and Fc gamma RII remained unchanged. Surface Fc gamma RIII expression remained depressed for 7 h after exposure of MDMs to either cytokine but then rose progressively until, by 24 h of stimulation, the levels were at least as high as those on unstimulated cells. In parallel with cell surface Fc gamma RIII levels, phagocytosis of immunoglobulin G-opsonized fluorescent beads, as measured by FACS, decreased and then increased over time after stimulation of MDMs with TNF-alpha while the opsonin-independent phagocytic activity was unchanged, suggesting that among the three classes of Fc gamma receptors on macrophages, Fc gamma RIII may play a critical role in regulating opsonic phagocytosis. After treatment with IL-1 beta, both opsonic and nonopsonic phagocytic activities of MDMs were significantly decreased, regardless of Fc gamma RIII levels. FACS analysis of rhodamine-phalloidin-stained MDMs showed that after incubation with IL-1 beta, but not TNF-alpha, the content of F-actin declined in MDMs, coinciding with inhibition of particle phagocytosis. Rapid down-regulation and subsequent recovery of macrophage Fc gamma RIII expression following cytokine stimulation could serve as a novel regulatory mechanism employed by inflammatory cells in host defense.

Paracrine downregulation of Fc gamma RIII in human monocyte-derived macrophages induced by phagocytosis of nonopsonized particles

Monocytes and macrophages can take up nonopsonized particles through a direct phagocytic process and IgG-coated particles through combined mechanisms of nonspecific phagocytosis and internalization mediated by specific Fc receptors for IgG (Fc gamma R) on the plasma membrane. In this study, we report the effect of phagocytosis of nonopsonized latex beads on the levels of expression of Fc gamma receptors in human monocyte-derived macrophages (MDM) as measured by flow cytometry (fluorescence-activated cell sorter [FACS]). Macrophages were exposed to green fluorescent 1-micron polystyrene beads before labeling for Fc gamma RI, Fc gamma R-II, and Fc gamma R-III, respectively, with 32.2, 2E1, and 3G8 monoclonal antibodies (MoAbs) and a phycoerythrin (PE)-conjugated secondary Ab to permit dual-channel analysis of fluorescence intensity by FACS. Macrophages that had phagocytosed at least one bead showed reduced levels of surface Fc gamma R-III but not Fc gamma R-I or Fc gamma R-II when compared with cells that had never been exposed to beads. Moreover, cells that were not in direct contact with beads, but that shared medium with cells that had phagocytosed beads also had reduced levels of Fc gamma R-III but not Fc gamma R-I or Fc gamma R-II, suggesting a cytokine-mediated mechanism of Fc gamma R-III downregulation. Phagocytosis of 1-micron beads alone stimulated macrophages to release tumor necrosis factor-alpha (TNF-alpha). The medium from macrophages phagocytosing beads could stimulate other macrophages not in direct contact with beads to release TNF-alpha as well, but such paracrine-triggered release could be reduced by more than 50% if the medium from the phagocytosing cells was first treated with a neutralizing anti-TNF-alpha antibody. Moreover, the paracrine downregulation of Fc gamma R-III described above could also be blocked if the neutralizing anti-TNF-alpha antibody was added to the medium of phagocytosing cells. Treatment of macrophages with recombinant human TNF-alpha in the absence of beads induced decreased levels of Fc gamma R-III but not of Fc gamma R-II. These results show that paracrine downregulation of Fc gamma R-III is mediated by a TNF-alpha-dependent mechanism.(ABSTRACT TRUNCATED AT 400 WORDS)

[A model of orthotopic transplantation of human hepatoma established in nude mice tumor inhibition studies]

We established a model of orthotopic transplantation of human hepato-carcinoma. The tissues from human hepatoma LTNM4 were surgically implanted into the livers of 32 BALB/c nu/nu nude mice. These led to the development of tum or masses in the livers of 31 nude mice; the rate of success was about 96.8% (31/32). Furthermore, this model was applied to the studies on the tumor inhibitory action of DHAQ-PBCA-NS, a hepatic targeting preparation for anticarcinoma. Satisfactory effect was attained. The result has proved the applicability of this animal model to researches on hepatic targeting preparations against carcinoma.

[An observation of the anticarcinogenic effect of mitoxantrone-polybutylcyanoacrylate-nanosperes]

This paper reports the result of an experiment on the anticarcinogenic effect of liver targeted drug delivery system-mitoxantrone-polybutylcyanoacrylate-nanospheres (DHAQ-PBCA-NS) by using a model of heterotopic and orthotopic transplantation of human hepatocellular carcinoma (HCC) in nude mice. No significant difference was noted between the anti-HCC effects of mitoxantrone and dexerubicin, but the anti-orthotopic transplanting HCC effect of mitoxantrone-nanospheres was obviously higher than that of mitoxantrone and dexerubicin by comparison of tumor inhibition rates and proliferating cell nuclear antigen (PCNA). The result showed the applicability of mitoxantrone-nanospheres.

Field evaluation of bednets impregnated with deltamethrin for malaria control

Trials were undertaken in a hypoendemic area of malaria in an area bordering Vietnam, in Napo County of Guangxi Zhuang Autonomous Region, China. The aim was to compare the relative cost effectiveness of DDT residual spraying and of bednets impregnated with deltamethrin in the malaria control program. The trials were divided into three subgroups: (1) two farming areas and one coal mining area with a total population > 20,000, where the trial consisted of mass bednets impregnated with deltamethrin 15 mg/m2 net surface once a year, (2) one farming area with a population of approximately 3,600 where DDT residual spraying at 2g/m2 was carried out twice a year in May and August; (3) one farming area and one coal mining village with a population of > 4,000 were used as a control. The malaria vector population consisted mainly of Anopheles minimus and An. anthropophagus with a small contribution from An. sinensis. After bednets were impregnated with deltamethrin the mosquitos resting on the surface of the bednets decreased significantly, although there was less effect on the total vector population. The results showed that malaria incidence decreased significantly both in areas where impregnated bednets were used and in areas where residual spraying was undertaken. The positive IFAT rates of residents who slept under impregnated bednets decreased significantly in farming areas, especially in that area where bednet impregnation as a vector control measure had been undertaken for two years, but there was no change in the IFAT rate in DDT sprayed or control areas.(ABSTRACT TRUNCATED AT 250 WORDS)

[Determination of apparent pharmacokinetic parameters of shengfu injection by acute mortality of mice]

Apparent pharmacokinetic parameters of Shengfu injection, a first-aid traditional Chinese medicine, were determined by acute mortality of animals. The results suggested that the pharmacokinetics of Shengfu injection accords with the two compartment open model, and t1/2 alpha = 0.063h, t1/2 beta = 2.70h. The process of distribution was quite rapid, and the process of elimination was slow.

[Pharmacokinetics model for targeted drug delivery systems]

Analyzing the observed phenomena and the data collected in research, we developed a multi-compartment linear recirculation model for targeted drug delivery systems and figured out the function formulas of the drug concentration-time in blood and target organ by computing. According to this model, the drug concentration-time curve for the target organ can be plotted with reference to the data on blood; the pharmacokinetics parameters of the target organ can also be obtained. We further detected the practicability of the model by using the curves of drug concentration-time in blood and target organ (liver) of liver-targeting nanoparticles obtained from animal tests. Based on the liver drug concentration-time curve calculated by the function formula of target organ and the statistical moment, the pharmacokinetics behaviour of the target organ (liver) was analysed and the pharmacokinetics parameters of liver were obtained. We suggest that the "relative targeting index" be used for quantitative evaluation of the targeted drug delivery system.