Control of cell migration direction by inducing cell shape asymmetry with patterned topography

In this study, we explored the concept of introducing asymmetry to cell shapes by patterned cell culture substrates, and investigated the consequence of this induced asymmetry to cell migration behaviors. Three patterns, named "Squares", "Grating", and "Arcs" were fabricated, representing different levels of rotational asymmetry. Using time-lapse imaging, we systematically compared the motility and directionality of mouse osteoblastic cells MC3T3-E1 cultured on these patterns. Cells were found to move progressively faster on "Arcs" than on "Grating", and cells on "Squares" were the slowest, suggesting that cell motility correlates with the level of rotational asymmetry of the repeating units of the pattern. Among these three patterns, on the "Arcs" pattern, the least symmetrical one, cells not only moved with the highest velocity but also the strongest directional persistence. Although this enhanced motility was not associated with the detected number of focal adhesion sites in the cells, the pattern asymmetry was reflected in the asymmetrical cell spreading. Cells on the "Arcs" pattern consistently displayed larger cytoplasmic protrusion on one side of the cell. This asymmetry in cell shape determined the direction and speed of cell migration. These observations suggest that topographical patterns that enhance the imbalance between the leading and trailing fronts of adherent cells will increase cell speed and control movement directions. Our discovery shows that complex cell behaviors such as the direction of cell movement are influenced by simple geometrical principles, which can be utilized as the design foundation for platforms that guide and sort cultured cells.

A meta-analysis of STAT3 and phospho-STAT3 expression and survival of patients with non-small-cell lung cancer

BACKGROUND

The prognostic role of signal transducer and activator of transcription 3 (STAT3) and phospho-STAT3 in non-small-cell lung cancer (NSCLC) remains controversial. To clarify its impact on survival, we performed a meta-analysis to quantitatively assess STAT3 and phospho-STAT3 expression on the prognosis of NSCLC.

METHODS

Published studies were identified using a systematic and thorough literature search. To be eligible, a study had to investigate STAT3 or phospho-STAT3 expression rates of NSCLC patients in different characteristics and provide patient survival data.

RESULTS

A total of 17 retrospective trials were chosen for meta-analysis, including 1793 patients. The estimated pooled log HR (0.67, 95% CI: 0.57-0.77) of 9 trials (STAT3: log HR 0.71, 95% CI 0.38-1.04; phospho-STAT3: log HR 0.67, 95% CI 0.56-0.77) for NSCLC was statistically significant (P < 0.0001), suggesting that high STAT3 or phospho-STAT3 expression is a strong predictor of poor prognosis among patients with NSCLC. For the risk factors, pooled analysis of patients with STAT3 positivity, demonstrated a statistically significant OR (3.82, 95% CI: 2.37-6.16) between poorly differentiated carcinoma and well-moderately, OR (5.68, 95% CI: 3.16-10.21) between stage III-IV patients and stage I-II patients, and OR (3.41, 95% CI: 2.12-5.49) between patients with lymph node metastasis and patients without lymph node metastasis. However, pooled analysis of patients with phospho-STAT3 positivity only demonstrated a statistically significant OR (4.51, 95% CI: 1.57-12.96) between poorly differentiated carcinoma and well-moderately (P < 0.05).

CONCLUSIONS

High STAT3 or phospho-STAT3 expression is a strong predictor of poor prognosis among patients with NSCLC. The conclusion should be confirmed by large prospective studies with long-term follow-up.

Macrophage biospecific extraction and HPLC-ESI-MSn analysis for screening immunological active components in Smilacis Glabrae Rhizoma

A cell-permeable membrane, as typified by Transwell insert Permeable Supports, permit accurate repeatable invasion assays, has been developed as a tool for screening immunological active components in Smilacis Glabrae Rhizoma (SGR). In this research, components in the water extract of SGR (ESGR) might conjugate with the receptors or other targets on macrophages which invaded Transwell inserts, and then the eluate which contained components biospecific binding to macrophages was identified by HPLC-ESI-MS(n) analysis. Six compounds, which could interact with macrophages, were detected and identified. Among these compounds, taxifolin (2) and astilbin (4) were identified by comparing with the chromatography of standards, while the four others including 5-O-caffeoylshikimic acid (1), neoastilbin (3), neoisoastilbin (5) and isoastilbin (6), were elucidated by their structure clearage characterizations of tandem mass spectrometry. Then compound 1 was isolated and purified from SGR, along with 2 and 4, was applied to the macrophage migration and adhesion assay in HUVEC (Human Umbilical Vein Endothelial Cells) -macrophages co-incultured Transwell system for immunological activity assessment. The results showed that compounds 1, 2 and 4 with concentration of 5μM (H), 500nM (M) and 50nM (L) could remarkably inhibit the macrophage migration and adhesion (Vs AGEs (Advanced Glycation End Produces) group, 1-L, 2-H and 4-L groups: p<0.05; other groups: p<0.01). Moreover, 1 and 4 showed satisfactory dose-effect relationship. In conclusion, the application of macrophage biospecific extraction coupled with HPLC-ESI-MS(n) analysis is a rapid, simple and reliable method for screening immunological active components from Traditional Chinese Medicine.

[Effect of HOXA10 gene silenced by shRNA on proliferation and apoptosis of U937cell line]

OBJECTIVE

To investigate the effects of lentivirus-mediated RNA interference targeting HOXA10 gene on the proliferation, apoptosis and morphology of leukemic cell line U937.

METHODS

Four different shRNA plasmids were designed and built to interfere with HOXA10 gene. The four interference plasmids were transfected into 293T cells with the HOXA10 over expression plasmid and then the RNAi efficiency of the four interference plasmids was determined by Western blot. The best one was chosen to transfect 293T cells with lentiviral helping plasmids to produce packaged lentivirus (lenti-shHOXA10). U937 cells were divided into interference group (lenti-shHOXA10), negative control group and untreated group. After infection with the packaged lentivirus, infection efficiency of lentivirus for U937 was detected by flow cytometry, and the expression of HOXA10 gene mRNA and protein was detected by real-time PCR and Western blot. Cell survival was determined by MTT assay. Apoptosis rate was detected by flow cytometry.

RESULTS

Lentiviral-shRNA vector of HOXA10 gene was successfully constructed. Compared with the negative control and untreated groups, mRNA level of HOXA10 decreased by (92.3±1.3)%, protein levels decreased by 91.1%, and the inhibition rate of U937 cells [(43.9±0.7)%] increased in the interference group (P<0.05). Wright's staining showed that the ratio of karyon to cytoplasm was reduced and mitotic phase was rare in the interference group. Apoptosis rate in the interference group [(27.1±1.4)%] was significantly higher than in the negative [(19.4±1.9)%] and untreated groups [(5.5±1.3)%] (P<0.05).

CONCLUSIONS

Lentivirus mediated RNAi can reduce the expression level of HOXA10, effectively inhibit proliferation and promote apoptosis of U937 cells. HOXA10 gene is expected to become a new target for the treatment of leukemia at gene level.

Nanofiltration process of glyphosate simulated wastewater

Nanofiltration separation of glyphosate simulated wastewater was investigated using a DK membrane. The effects of operating parameters and the addition of impurities on membrane performance were studied in detail. It was found that at 20 °C, with a glyphosate concentration of 500 mg/L and pH of 2.96, the glyphosate retention rate and the membrane permeate flux increased slightly with increasing transmembrane pressure. With an increase in operating temperature, the permeate flux increased linearly while the retention rate decreased. The permeate flux and glyphosate retention rate decreased with increasing feed concentration. Within the pH range of 3-5, the glyphosate retention rate decreases with increasing pH and reaches a minimum at the isoelectric point of the membrane, while the permeate flux reaches a maximum level at this point. In the pH range of 5-11, with the increases of pH, the glyphosate retention rate increases and the permeate flux decreases. Glyphosate retention decreases slightly with increasing NaCl and phosphite concentrations. This can be explained in terms of the shielding phenomenon.

A PKC-beta inhibitor prompts the HUVECs apoptosis-induced by advanced glycation end products

The accumulation of advanced glycation end products (AGEs) on micro-vasculature has been demonstrated to be a key factor in diabetes mellitus development. Evidence suggests that AGEs triggered apoptotic changes in human umbilical vein endothelial cells (HUVECs) and protein kinase C (PKC)-beta plays a pivotal role in AGEs-induced micro-vascular dysfunction. Thus the effect of the selective PKC-beta inhibitor (LY333531) on AGEs-induced HUVEC apoptosis and proliferation was investigated. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used to determine the cells viability after being incubated with AGEs and LY333531. Acridine orange/ethidium bromide (AO/EB) fluorescence detection was applied to observe the pro-apoptosis effects of AGEs and LY333531. Bcl-2, Bax and Bad proteins' expression were determined by StreptAvidin-Biotin-enzyme Complex (SABC) immunocytochenistry. The results showed that pretreatment with LY333531 strikingly decreased the chance of HUVEC survival and the effect of LY333531 on apoptotic cell death in HUVEC significantly increased compared with the AGEs group. Blockade of PKC-beta up-regulated the expression of Bax and Bad proteins and down- regulated the expression of Bcl-2 protein. Moreover, LY333531 reduced the ratio of Bcl-2/Bax. The results indicate that the selective PKC-beta inhibitor, LY333531, can further prompt AGEs-induced endothelial cells apoptosis. The increased expression of Bax, Bad and decreased expression of Bcl-2 and Bcl-2/Bax ratio are associated with the apoptotic process.

Genotyping of Toxoplasma gondii isolates from cats in different geographic regions of China

Fourteen isolates of Toxoplasma gondii were isolated from cats from 4 different geographic provinces (Anhui, Hubei, Shanxi and Guangdong) in China and their genetic diversity with 8 nuclear loci SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and an apicoplast locus Apico, was analysed by restriction fragment length polymorphisms (RFLPs). Two genotypes from these 14 isolates were identified but none of them belongs to the typical genetic types (types I, II and III). It is unexpected that such high similarity was observed in these 14 isolates although their original regions are significantly distant. Our results strongly indicate that the three traditional clonal lineages of types I, II and III of this parasite may not be preponderant in China. In addition, our results show that the genotypes of T. gondii in China may be highly clonal with atypical genotypes and higher virulence.

Accumulation and distribution of α-synuclein and ubiquitin in the CNS of Gaucher disease mouse models

Gaucher disease, a prevalent lysosomal storage disease, is caused by insufficient activity of acid β-glucosidase (GCase) and resultant glucosylceramide accumulation. Recently in Parkinson disease (PD) patients, heterozygous mutations in GCase have been associated with earlier onset and more progressive PD. To understand the pathogenic relationships between GCase variants and Parkinsonism, α-synuclein and ubiquitin distributions and levels in the brains of several mouse models containing GCase variants were evaluated by immunohistochemistry. Progressive α-synuclein and ubiquitin aggregate accumulations were observed in the cortex, hippocampus, basal ganglia, brainstem, and some cerebellar regions between 4 and 24 weeks in mice that were homozygous for GCase [D409H (9H) or V394L (4L)] variants and also had a prosaposin hypomorphic (PS-NA) transgene. In 4L/PS-NA and 9H/PS-NA mice, this was coincident with progressive neurological manifestations and brain glucosylceramide accumulation. Ultrastructural studies showed electron dense inclusion bodies in neurons and axons of 9H/PS-NA brains. α-synuclein aggregates were also observed in ventricular, brainstem, and cerebellar regions of older mice (>42-weeks) with the GCase variant (D409H/D409H) without overt neurological disease. In a chemically induced GCase deficiency, α-synuclein aggregates and glucosylceramide accumulation also occurred. These studies demonstrate a relationship between glucosylceramide accumulation and α-synuclein aggregates, and implicate glucosylceramide accumulation as risk factor for the α-synucleinopathies.

Oleanolic acid from Prunella Vulgaris L. induces SPC-A-1 cell line apoptosis via regulation of Bax, Bad and Bcl-2 expression

Prunella vulgaris L. (PV) has been used as a herb for chemoprevention of lung cancer. In this study, the main active compound, oleanolic acid (OA) was isolated from an ethanol extract and its chemical structure was identified according to the results of high performance liquid chromatography (HPLC), high performance thin layer chromatography (HPTLC) and liquid chromatography-mass spectrography (LC-MS). Results for cell viability indictated no notable differences between OA and ethanol extract of PV in lung adenocarcinoma SPC-A-1 cells measured by MTT assay. Consistent concentration-response curves. Fluorescence detection with acridine orange-ethidium bromide was used to evaluate apoptosis of SPC-A-1 cells. OA at 16 and 8 microM group increased significantly the apoptosis rate compared with normal and 1% DMSO groups (p<0.05). In addition, immunocytochemistry assays showed increase in Bax and Bad protein expression while Bcl-2 decreased. Moreover, the ratio of Bax/Bcl-2 was heightened by OA treatment. The results suggest OA induced apoptosis of lung adenocarcinoma cells through down-regulating Bcl-2 expression, and up-regulating Bax and Bad expression.

Overexpression of CDR1 and CDR2 genes plays an important role in fluconazole resistance in Candida albicans with G487T and T916C mutations

This study was designed to investigate potential resistance mechanisms by studying the expression of resistant genes in 14 fluconazole-resistant Candida albicans isolates, with G487T and T916C mutations in the 14alpha-demethylase (ERG11) gene, collected from human immunodeficiency virus uninfected patients and a fluconazole-susceptible control strain. The in vitro susceptibilities of the C. albicans isolates to fluconazole were determined using the broth microdilution method and a disc diffusion assay. Expression of Candida drug resistance (CDR)1, CDR2, ERG11, fluconazole resistance (FLU)1 and multidrug resistance (MDR)1 genes was measured using real-time reverse transcription-polymerase chain reaction and evaluated relative to the expression of the control gene 18SrRNA. The CDR1 and CDR2 genes were upregulated in all the fluconazole-resistant C. albicans isolates, whereas only a few isolates showed high expression of MDR1, FLU1 and ERG11 genes compared with the control strain. In conclusion, overexpression of the CDR1 and CDR2 genes may play an important role in fluconazole-resistant C. albicans with G487T and T916C mutations.

[Effect of siRNA targeting VEGF on cell apoptosis and the expression of survivin in K562 cells.]

OBJECTIVE

To study the effect of adenovirus vector-mediated siRNA targeting vascular endothelial growth factor(VEGF) on apoptosis and the expression of survivin in K562 cells.

METHODS

K562 cells were infected with recombinant adenovirus Ad5-VEGFsi for 72 hours as experimental group (K562/Ad5-VEGFsi), and empty vector group (K562/Ad5) and blank control group (K562) as controls. VEGF mRNA and survivin mRNA expression were determined by RT-PCR. The protein levels of VEGF and survivin were measured by ELISA and Western blot, respectively. The apoptosis of K562 cells was detected by flow cytometry.

RESULTS

The levels of VEGF and survivin mRNA expression in experimental group cells were significantly decreased (P < 0.01). The protein concentration of VEGF in experimental group supernatant was (1121 +/- 15) pg/ml, being lower than that in empty vector group \[(1290 +/- 28) pg/ml\] and black control group \[(1303 +/- 28) pg/ml\] (P < 0.01), and the level of survivin protein in experimental group (0.26 +/- 0.11) was significantly reduced compared with that in blank control group (0.74 +/- 0.10) (P < 0.01). The apoptosis rate of K562/Ad5-VEGFsi cells (16.45 +/- 0.14)% was higher than those of K562/Ad5 cells (3.54 +/- 0.17)% and K562 cells (2.56 +/- 0.20)% (P < 0.01).

CONCLUSIONS

VEGF can up-regulate the expression of survivin. After inhibition of VEGF by RNAi, the expression of survivin is decreased subsequently and the rates of cell apoptosis are increased.

[Clinical significance of HA117 expression in children with acute leukemia]

OBJECTIVE

To explore the role of the expression of HA117 gene in bone marrow mononuclear cells (BMMNC) with acute leukemia and multidrug resistance.

METHODS

HA117 gene expressions in 36 children with acute leukemia and 10 children with Idiopathic thrombocytopenic purpura (ITP) were tested using semi quantitative reverse transcriptase polymerase chain reaction (RT-PCR) technique.

RESULTS

The HA117 gene was expressed in 75% of children with acute leukemia. There was no significant difference in HA117 gene expression between children with acute lymphoblastic leukemia (ALL, 69.57%) and children with acute myeloid leukemia (AML, 91.67%). But the semi-quantitative expression of HA117/beta-actin in AML childern was significantly higher than in ALL children (q=4.5852, P<0.01). The expressions of HA117 gene and HA117/beta-actin in both ALL and AML children were significantly higher than in ITP children chi2=5.05, 8.81; q=4.4612, 6.9695; P<0.05). The remission patients had lower expression of HA117/beta-actin and similar expression of HA117 compared with initially diagnosed patients. The remission patients had higher expression of HA117 gene and similar expression of HA117/beta-actin compared with patients with ITP. The non-remission patients had higher expression of HA117/beta-actin than remission patients and ITP patients (q=3.1705, 4.4102, P<0.05), but no significant difference from initially diagnosed patients (q=0.5470, P>0.05).

CONCLUSION

The expression of HA117 gene is high in the BMMNC of initially diagnosed and non-remission patients with AL. But the remission patients have similar semi-quantitative expression of HA117 as patients with ITP, which indicates that a quantitative testing is more important. The expression of HA117 gene decreases with the improvement of the illness. HA117 is one of the factors that may affect the clinical remission of AML. The new gene HA117 may also be associated with multidrug resistance of leukemia.

[Effects of Tanshinone IIa on cytokines and platelets in immune vasculitis and its mechanism]

The objective of this study was to investigate the effect of Tanshinone IIa on IL-1beta, IL-6 and TNF-alpha cytokines in immune vasculitis and platelets, as well as their relationship. The model of immune vasculitis of rabbits were established by intravenous injection of bovine serum albumin twice. Experiment was divided into 4 groups: control group, model group, tanshinone IIa-treated group and aspirin-treated group. The platelet count, platelet aggregation of peripheral blood were determined. The levels of serum IL-1beta, IL-6, TNF-alpha were detected by ELISA. The pathological changes of immune vasculitis were analyzed by hematoxylin & eosin staining, elastic fibers staining and electron microscopy. The results showed that the levels of IL-1beta and TNF-alpha in model group were significantly higher than those in normal group (p < 0.05), while the level of IL-6 was not significantly different between various groups. The serum level of IL-1beta was correlated with platelet number, while serum levels IL-1beta and TNF-alpha were both correlated with the platelet aggregation. The treatment with tanshinone IIa could significantly decrease the serum levels of IL-1beta, TNF-alpha and platelet number, and the efficacy of tanshinone IIa was same as aspirin. The tanshinone IIa and aspirin both could alleviate the vessels damage in patients with immune vasculitis. It is concluded that the tanshinone IIa may diminish the inflammation damage of vessels in patients with immune vasculitis through the inhibition of cytokines and platelets.

[Effects of matrine on invasion and metastasis of leukemia cell line Jurkat]

OBJECTIVE

To study the inhibitory effects of matrine, in different concentrations, on invasion and metastasis of human acute lymphocytic leukemia cell line Jurkat.

METHODS

In vitro cultured Jurkat cells were treated by matrine in concentration of 0 g/L, 0.1 g/L, 0.15 g/L and 0.2 g/L, respectively. Then cell adhesion assay, cell migration assay and matrigel invasion assay were used respectively to observe the effects of matrine on adhesion, migration and invasive capacity of Jurkat cells. Meantime, RT-PCR was performed to detect the matrix metalloproteinase (MMP)-2 and MMP-9 mRNA expression levels. Comparison of measurement data among groups was analyzed by variance analysis.

RESULTS

As compared with the control group, the adhesion of Jurkat to fibronectin (FN) was significantly inhibited by 0.15 g/L and 0.2 g/L of matrine (P < 0.05); the cell migration and invasive capacity were significantly lowered by 0.1 g/L, 0.15 g/L and 0.2 g/L matrine (P < 0.01). High mRNA expression of MMP-9 presented but that of MMP-2 was expressed insignificantly in Jurkat cells, matrine at 0.1 g/L, 0.15 g/L and 0.2 g/L showed obvious effect in down-regulating MMP-9 mRNA expression (P < 0.01). Besides, MMP-9 mRNA expression was found to be positively correlated with the invasive capacity of Jurkat cells (r = 0.940, P < 0.01).

CONCLUSIONS

Matrine is a good drug for antagonizing the invasion and metastasis of leukemia cells, it may roundly inhibit the adhesion, migration and invasive capacity of Jurkat cells, the mechanism might be related with the down-regulation of MMP-9 mRNA expression.

[Hematopoiesis support of mesenchymal stem cells in children with aplastic anemia]

OBJECTIVE

The abnormality of hemopoietic inductive microenvironment (HIM) is involved in the pathophysiology of aplastic anemia (AA). Mesenchymal stem cells (MSC) are main source of bone marrow stromal cells which constitute the bone marrow HIM. Thus, the bone marrow failure in AA may be related to the function of MSC. The aim of the study was to investigate the hematopoiesis support function of MSC in children with AA in vitro.

METHODS

Bone marrow samples were collected from 24 children with AA at diagnosis and 19 children with idiopathic thrombocytopenic purpura (ITP), infectious mononucleosis or lymphadenitis (controls). MSCs from bone marrow samples were isolated, cultured and expanded. Morphology, proliferation activity and colony forming unit-fibroblast (CFU-F) were measured. The ability of bone marrow MSC to adhere hemopoietic cells was assayed by MTT. The concentration of stem cell factor (SCF) released from MSC was tested using ELISA. Mononuclear cells (MNC) of bone marrow were plated onto a feeder layer formed by MSC. Cells count and BFU-E, CFU-GM, CFU-GMME productions were measured.

RESULTS

The first and third passage time of MSC in children with AA was longer than that in the controls. The number of CFU-F in children with AA (15.70+/-5.78) was less than that in the controls (21.73+/-5.74) (P<0.05). The concentration of SCF in MSC supernatants in children with AA (30.69+/-16.82 pg/mL) was significantly lower than the controls (50.74+/-14.83 pg/mL) (P<0.01). The total MNC count and the number of BFU-E, CFU-GM and CFU-GMME colonies in the support of MSC in children with AA were significantly lower than those in the controls (P<0.01).

CONCLUSIONS

The hematopoiesis support function of MSC was significantly reduced in children with AA in vitro. The decreased hematopoiesis support function of MSC may be related its decreased proliferation capacity and SCF release activity.

Three mutations analysis of glucose-6-phosphate dehydrogenase deficiency in neonates in South-west China

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, one of the most common human enzymatic defects, is characterized by extreme molecular and biochemical heterogeneity. The underlying DNA changes associated with G6PD deficiency in Asian subjects have not been extensively investigated.

METHODS

Three gene mutations (G1388A, G1376T, A95G, corresponding amino acid change: Arg463His, Arg459Leu, His32Arg, respectively) were examined in 240 G6PD-deficient subjects originating from South-west China using specific polymerase chain reaction.

RESULTS

Of the 240 patients with G6PD deficiency, 190 were found to have the G1388A mutation, 48 had G1376T and two had A95G. There were no significant differences between the clinical manifestations caused by the former two gene mutations, which both cause acute hemolytic anemia and jaundice. Therefore the most common gene mutations of G6PD deficiency in neonates in South-west China are G1388A and G1376T mutations.

CONCLUSION

It is suggested that G6PD deficiency screening be done in higher risk neonates with jaundice in qualified hospitals as soon as possible.

RETRACTED: Isolation, characterization and expression of a gene from Brassica napus encoding a LIM-domain protein

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Light extraction efficiency of a top-emission organic light-emitting diode with an Yb/Au double-layer cathode and an opaque Si anode

We have computed the transmittances of four types of cathode--Yb/Au, Al/Au, Yb/Ag, and Al/Ag double layers--and the light extraction efficiencies of the top-emission organic light-emitting diodes with these cathodes, respectively, based on the characteristic matrix method and the dissipation spectrum model. Computations show that the Yb/Au cathode has a markedly higher transmittance than the other three types of cathode when the Yb and Au thicknesses in the Yb/Au cathode are, respectively, equal to the Al (or Yb) and Au (or Ag) thicknesses in the other three types of cathode. The power lost to the Yb/Au cathode due to the surface plasmon polaritons is the lowest, and hence the device with the Yb/Au cathode has the highest extraction efficiency. The transmittances for the four cathodes are also measured experimentally.

Toroidal plasma rotation induced by the dynamic ergodic divertor in the TEXTOR tokamak

The first results of the Dynamic Ergodic Divertor in TEXTOR, when operating in the m/n=3/1 mode configuration, are presented. The deeply penetrating external magnetic field perturbation of this configuration increases the toroidal plasma rotation. Staying below the excitation threshold for the m/n=2/1 tearing mode, this toroidal rotation is always in the direction of the plasma current, even if the toroidal projection of the rotating magnetic field perturbation is in the opposite direction. The observed toroidal rotation direction is consistent with a radial electric field, generated by an enhanced electron transport in the ergodic layers near the resonances of the perturbation. This is an effect different from theoretical predictions, which assume a direct coupling between rotating perturbation and plasma to be the dominant effect of momentum transfer.

Acceptor proteins of rat prostate residual chromatin

The androgen acceptor sites of the rat prostate residual chromatin (2 M NaCl insoluble fraction of chromatin) have been determined by steroid exchange assay, binding of translocated androgen-receptor complex in vitro, and solubilization of the acceptor protein(s) from the residual chromatin. Binding of [3H]dihydrotestosterone to the residual chromatin was saturable, displaying high affinity (Kd = 3.1 nM) and low capacity (6.3 nmol/mg of protein). The binding of [3H]dihydrotestosterone by the residual chromatin was androgen specific, as shown by steroid competition experiments. Intrachromatin binding study of translocated 5 alpha-[3H]dihydrotestosterone-receptor indicated that the residual chromatin contained 31% of the total chromatin-bound androgen, thus representing one of the major chromatin-androgen binding sites. The results suggested the presence of acceptor molecules in the residual chromatin with which the androgen-receptor interacted. To ascertain this, the residual chromatin was extracted with phenol, and the phenol-solubilized protein(s) was (were) assayed for acceptor activity by interaction with [3H]dihydrotestosterone-receptor complex. Comparison of phenol-solubilized residual proteins from rat prostate, spleen, and chicken erythrocyte indicated that [3H]dihydrotestosterone-receptor complex bound tissue specifically to the prostate residual protein and that the interaction required the presence of DNA. The possible importance of the residual DNA was examined by reannealing with cloned cDNAs coding for the subunit components of prostatic binding protein, an androgen-regulated oligomeric protein in rat prostate. The rates of reassociation kinetics of the residual DNA with the cDNAs were faster than with total DNA, equivalent to a 3-fold enrichment in prostatic binding protein coding sequences. The high salt resistant residual chromatin acceptor(s) thus appear(s) to be preferentially associated with androgen-activated genes.

[Relationship between serum C-reactive protein and creatine kinase isoenzyme in acute myocardial infarction]

OBJECTIVE

To investigate the relationship between serum c-reactive protein(CRP) and creatine kinase isoenzyme (CK-MB) in the diagnosis of acute myocardial infarction (AMI).

METHODS

We assessed the serum CK-MB and CRP concentration in 52 patients with definite AMI at different time after their infarction.

RESULTS

12 hours after infarction there were 100% and 44.2% patients with positive results in CK-MB and CRP respectively, and 48 hours are 57.7% and 86.5%. By continuous observation we found that the peaks of CK-MB and CRP occurred respectively at 12 hours and 48 hours after infarction.

CONCLUSION

It is suggested that as a diagnostic marker CRP is superior to CK-MB in sabacent myocardial infarction patients.

A comparative study of third-order nonlinear optical properties of silver phenylacetylide and related compounds via ultrafast optical Kerr effect measurements

A comparative study of the third-order nonlinear optical properties, via the newly developed heterodyned optical Kerr effect (OHD-OKE) measurements, of silver phenylacetylide and related compounds is reported. [AgC[triple bond]CC(6)H(5)](n) (1) was found to exhibit efficient third-order nonlinear optical susceptibility chi((3)) of 2.4 x 10(-14) esu, and second hyperpolarizability gamma of 9.07 x 10(-32) esu. These results are compared with those of two related silver phenylacetylide compounds, namely, a double salt, (silver phenylacetylide).(silver tert-butylthiolate) [AgC[triple bond]CC(6)H(5).AgS(t-C(4)H(9))](n) complex (2), and a cluster, triphenylphosphine silver phenylacetylide tetramer, [(C(6)H(5))(3)PAgC[triple bond]CC(6)H(5)](4) (3), as well as that of the related organic polymer polyphenylacetylene (4). These four compounds represent different types of phenylacetylide derivatives: 1 is an organometallic polymer, 2 a polymeric double salt, 3 a discrete metal cluster, and 4 an organic polymer. It was found that the third-order optical nonlinear response was enhanced by the incorporation of silver d electrons into the delocalized conjugated organic pi system, and its magnitude is highly dependent upon the extent of the pi delocalization. Specifically, the relative magnitudes of chi((3)) and gamma follow the order silver phenylacetylide polymer (1) > (silver phenylacetylide).(silver tert-butylthiolate) double salt (2) > polyphenylacetylene polymer (4) > tetrameric (triphenylphosphine silver phenylacetylide)(4) cluster (3). The observed trend may be attributed to the decreasing length of pi conjugation. It is interesting to note that the incorporation of Ag(I) into the polymeric framework of polyphenylacetylene enhances the chi((3)) by 25-fold for the same degree of polymerization (n = 7). The signs of chi((3)) and gamma, which are related to the response mechanisms, were found to be solvent dependent.

[Cloning and characterization of syap1, a down regulated gene in human hepatocellular carcinoma]

Using a different fragment DE6 obtained from DD-PCR as probe, a full-length cDNA has been cloned from human liver cDNA library and named as syap1 (Synapse-associated protein 1) because its deduced amino acid sequence is homologous to SAP47 of D. melanogaster. Northern blot analysis reveals that two transcripts of syap1 mRNA are expressed in cultured human liver L-02 cells. Moreover, the syap1 mRNA was also detected in most of adult human tissues by RT-PCR analysis. Down-regulated expression of syap1 mRNA was confirmed by semi-quantitative RT-PCR assay in 5 of 10 (50%) cases of human hepatocellular carcinoma (HCC).

Anti-human hepatocellular carcinoma effects of tumor necrosis factor-related apoptosis-inducing ligand in vitro & in vivo

AIM

To investigate the effect of over-expression of Bcl-2 protein on Trail protein-induced apoptosis in human hepatoma cells, and the cytotoxicity of Trail protein on human hepatoma cells in vitro and in vivo.

METHODS

The Trail gene was cloned and expressed in E coli. The cytotoxicity of the recombinant Trail protein was assayed on human hepatoma cells in vitro and in vivo. The cell viability was assessed by trypan blue exclusion. The stable human hepatoma cells clone in which Bcl-2 protein over-expressed was established by transfecting eukaryotic expression plasmid pcDNA3-Bcl-2 into BEL-7404 human hepatoma cells, and was selected with G418 400 mg/L.

RESULTS

The recombinant Trail protein actively killed human hepatoma cells tested in this study such as BEL-7404, BEL-7402, and SMMC-7721. Over-expression of Bcl-2 protein could inhibit apoptosis induced by Trail in BEL-7404 human hepatoma cells in vitro. It was obvious that the purified recombinant Trail protein could inhibit tumor formation of BEL-7404 human hepatoma cells in nude mice.

CONCLUSION

The recombinant Trail protein could kill human hepatoma cells in vitro and in vivo. Over-expression of Bcl-2 protein could inhibit Trail-induced apoptosis in BEL-7404 human hepatoma cells. The results suggested that Trail might be a potential agent for the liver cancer therapy.