Highly reversible extrinsic electrocaloric effects over a wide temperature range in epitaxially strained SrTiO3 films

Electrocaloric effects have been experimentally studied in ferroelectrics and incipient ferroelectrics, but not incipient ferroelectrics driven ferroelectric using strain. Here we use optimally oriented interdigitated surface electrodes to investigate extrinsic electrocaloric effects in low-loss epitaxial SrTiO3 films near the broad second-order 243 K ferroelectric phase transition created by biaxial in-plane coherent tensile strain from DyScO3 substrates. Our extrinsic electrocaloric effects are an order of magnitude larger than the corresponding effects in bulk SrTiO3 over a wide range of temperatures including room temperature, and unlike electrocaloric effects associated with first-order transitions they are highly reversible in unipolar applied fields. Additionally, the canonical Landau description for strained SrTiO3 films works well if we set the low-temperature zero-field polarization along one of the in-plane pseudocubic <100> directions. In future, similar strain engineering could be exploited for other films, multilayers and bulk samples to increase the range of electrocaloric materials for energy efficient cooling.

[Formation of professor Mao Xiejun's thoughts on stomatological education]

Professor Mao Xiejun wrote a report about dental education of China in 1935. From 1948 to 1950, he published three articles containing the educational idea of "developing dentistry into stomatology". When he served as the director of the Faculty of Dentistry of Peking University Medical School in July 1950, he proposed to rename the Faculty of Dentistry into the Faculty of Stomatology,which were approved by the Ministry of Health and the Ministry of Education of the People's Republic of China in one month. The Chinese Medical Association established the Society of Stomatology the next year. Later, dentistry was successively changed into stomatology, and medical content was integrated into dental education, which was of great significance and far-reaching influence. During the developments of the thought of stomatological education in China, Professor Mao Xiejun evidently played a pivotal role. In this paper, the formation process of the thoughts of stomatological education related to professor Mao Xiejun's contribution is elucidated through studying the archives, personal letters, and historical documents, so as to enrich the researches on the history of stomatology in China and to facilitate better understanding and promoting the development of stomatology.

Tunable electronic properties and related functional devices for ferroelectric In2Se3/MoSSe van der Waals heterostructures

In recent years, two-dimensional (2D) materials have attracted increasing attraction in a number of scientific research fields. In particular, ferroelectric materials with reversible spontaneous electric polarization and Janus transition metal dichalcogenides (TMDs) with intrinsic dipoles exhibit novel properties for many practical applications. Here, the electronic properties of van der Waals (vdW) heterostructures consisting of In₂Se₃ and MoSSe were investigated based on a first-principles approach. It was demonstrated that four studied In₂Se₃/MoSSe heterostructures exhibited obvious band gap (E _g) differences, ranging 0.13 to 0.90 eV for PBE (0.47 to 1.50 eV for HSE06) owing to the reversible spontaneous electric polarization of In₂Se₃ and different intrinsic dipole of MoSSe, and different band alignments of type-I or type-II could also be obtained. The energy bands of the four vdW heterostructures could be obviously regulated by varying degrees of vertical (horizontal) strain and vertical interface electric field, and the E _g varied from zero to 1.27 eV. Then, M4-based mechanical switching devices and ferroelectric diodes were designed based on the significant strain and electric field function. These results provide one possible mechanism for how the polarization direction regulates the physical properties of the system due to the different charges on the two surfaces of the out-of-plane polarized ferroelectric material, which may lead to different proximity effects on the face of the material.

SrB4O7:Sm2+ fluorescence improves the accuracy of temperature measurements in externally heated diamond anvil cells

The sample temperature in an externally heated diamond anvil cell (EHDAC) is generally measured by a thermocouple fixed to the pavilions of diamond anvils, ignoring the temperature difference between the thermocouple and the sample. However, the measured temperature depends strongly on the placement of the thermocouple, thus seriously reducing the accuracy of the temperature measurement and hindering the use of EHDAC in experiments requiring precise temperature measurements, such as high-pressure melting and phase-diagram investigations. In this study, the full width at half maximum (FWHM) of the 0-0 fluorescence line of strontium borate doped with bivalent samarium ions (SrBO₄:Sm²⁺, SBO) is found to be highly sensitive to temperature and responds extremely rapidly to small temperature fluctuations, which makes it an excellent temperature indicator. We propose herein a precise method to measure temperature that involves measuring the FWHM of the 0-0 fluorescence line of SBO. This method is used to correct the temperature discrepancy between the thermocouple and the sample in an EHDAC. These corrections significantly improve the accuracy of temperature measurements in EHDACs. The accuracy of this method is verified by measuring the melting point of tin at ambient pressure. We also use this method to produce a tentative elementary phase diagram of tin up to 109 GPa and 495 K. This method facilitates high-pressure, high-temperature experiments demanding accurate temperature measurements in various disciplines. The study also discusses, in general, the experimental approach to measuring temperature.

Tunable electronic and optical properties of a BAs/As heterostructure by vertical strain and external electric field

The CBM (VBM) of the heterostructure is mainly contributed by the BAs (arsenene), which will favor the separation of photogenerated electron–hole pairs.

Predictive value of recurrence for serum hypoxia inducible factor-1α C-reaction protein in hepatocellular carcinoma patients after transcatheter arterial chemoembolization

OBJECTIVES

The purpose of this study was to evaluate the predictive value of recurrence for serum hypoxia inducible factor-1α (HIF-1α), C-reaction protein (CRP) in hepatocellular carcinoma patients after transcatheter arterial chemoembolization (TACE).

PATIENTS AND METHODS

Fifty-eight hepatocellular carcinoma patients treated with TACE were included in this study from February 2010 to January 2013 as the case group. Of the included 58 cases, 47 patients had recurrence disease, and other 11 cases had no recurrence disease within 2 years follow-up. Moreover, 62 subjects with no benign liver disease were recruited as a control group in the same period. The serum level of HIF-1α and CRP were tested in case group and control group 1-week after TACE. The serum level of HIF-1α and CRP were compared among the recurrence, nonrecurrence, and benign liver disease patients. The predictive value of recurrence for serum HIF-1α, CRP was calculated by Bayes' theorem.

RESULTS

The serum HIF-1α and CRP level was arrayed 1-week after TACE. For recurrence cases, the serum level of HIF-1α and CRP was 2457.00 ± 335.70 pg/ml and 11.46 ± 3.25 mg/L. For nonrecurrence subjects, the serum level of HIF-1α and CRP was 2067.00 ± 175.900 pg/ml and 8.99 ± 1.70 mg/L. Moreover, for the benign liver disease patients, the serum level of HIF-1α and CRP was 1897.00 ± 121.33 pg/ml and 6.11 ± 1.2 mg/L. The serum level of HIF-1α and CRP was significantly higher in hepatocellular carcinoma patients than that of benign liver disease patients (P < 0.05); The recurrence predictive sensitivity and specificity of HIF-1α for hepatocellular carcinoma patients after TACE chemoembolization was 76.60% and 81.82% with the area under the curve (AUC) receiver operating characteristic (ROC) curve of 0.85; The recurrence predictive sensitivity and specificity of CRP for hepatocellular carcinoma patients after TACE was 65.96% and 63.64% with the AUC/ROC of 0.74.

CONCLUSION

The serum level of HIF-1α and CRP was elevated in recurrence patients which could be a potential marker for recurrence prediction.

Epithelial-mesenchymal transition of ovarian cancer cells is sustained by Rac1 through simultaneous activation of MEK1/2 and Src signaling pathways

Epithelial-mesenchymal transition (EMT) is regarded as a crucial contributing factor to cancer progression. Diverse factors have been identified as potent EMT inducers in ovarian cancer. However, molecular mechanism sustaining EMT of ovarian cancer cells remains elusive. Here, we show that the presence of SOS1/EPS8/ABI1 complex is critical for sustained EMT traits of ovarian cancer cells. Consistent with the role of SOS1/EPS8/ABI1 complex as a Rac1-specific guanine nucleotide exchange factor, depleting Rac1 results in the loss of most of mesenchymal traits in mesenchymal-like ovarian cancer cells while expressing constitutively active Rac1 leads to EMT in epithelial-like ovarian cancer cells. With the aid of clinically tested inhibitors targeting various EMT-associated signaling pathways, we show that only combined treatment of MEK1/2 and Src inhibitors can abolish constitutively active Rac1-led EMT and mesenchymal traits displayed by mesenchymal-like ovarian cancer cells. Further experiments also reveal that EMT can be induced in epithelial-like ovarian cancer cells by co-expressing constitutively active MEK1 and Src rather than either alone. As the activities of Erk and Src are higher in ovarian cancer cells with constitutively active Rac1, we conclude that Rac1 sustains ovarian cancer cell EMT through simultaneous activation of MEK1/2 and Src signaling pathways. Importantly, we demonstrate that combined use of MEK1/2 and Src inhibitors effectively suppresses development of intraperitoneal xenografts and prolongs the survival of ovarian cancer-bearing mice. This study suggests that cocktail of MEK1/2 and Src inhibitors represents an effective therapeutic strategy against ovarian cancer progression.

Enhanced sorption of naphthalene and p-nitrophenol by nano-SiO2 modified with a cationic surfactant

In this study, we observed that modification of nano-oxides (e.g., nano-SiO2) with cationic surfactants (e.g., cetyl pyridinium chloride, CPC) could be a potential way to make nano-oxides be superior sorbents with a partition mechanism for the sorptive removal of organic contaminants from wastewater where the coated CPC was an effective organic phase for partitioning. The partitioning of nonpolar naphthalene into coated CPC was induced by hydrophobic effect alone and presenting linear isotherms, while that of polar p-nitrophenol was induced by not only the hydrophobic effect but also the hydrogen-bonding interaction and presenting isotherm nonlinearity. The sorption affinity for naphthalene and p-nitrophenol partitioning into the coated CPC and the configuration of coated CPC remained unchanged although the amounts of coated CPC were increased. Linear relationships were established between the coated CPC amounts and the sorption capacities of naphthalene or p-nitrophenol, which could be used to predict the sorption of organic contaminants on surfactant-modified nano-oxides. In addition, these observed results would be also valuable for estimating the environmental behaviors and risks of nano-SiO2 and organic contaminants because nano-SiO2 would be inevitably coated with ubiquitous surfactants in the environment due to the discharging from the wide domestic and industry applications.

Downregulation of miR-181a upregulates sirtuin-1 (SIRT1) and improves hepatic insulin sensitivity

AIMS/HYPOTHESIS

Sirtuin-1 (SIRT1) is a potential therapeutic target to combat insulin resistance and type 2 diabetes. This study aims to identify a microRNA (miRNA) targeting SIRT1 to regulate hepatic insulin sensitivity.

METHODS

Luciferase assay combined with mutation and immunoblotting was used to screen and verify the bioinformatically predicted miRNAs. miRNA and mRNA levels were measured by real-time PCR. Insulin signalling was detected by immunoblotting and glycogen synthesis. Involvement of SIRT1 was studied with adenovirus, inhibitor and SIRT1-deficient hepatocytes. The role of miR-181a in vivo was explored with adenovirus and locked nucleic acid antisense oligonucleotides.

RESULTS

miR-181a targets the 3' untranslated region (3'UTR) of Sirt1 mRNA through a miR-181a binding site, and downregulates SIRT1 protein abundance at the translational level. miR-181a is increased in insulin-resistant cultured hepatocytes and liver, and in the serum of diabetic patients. Overexpression of miR-181a decreases SIRT1 protein levels and activity, and causes insulin resistance in hepatic cells. Inhibition of miR-181a by antisense oligonucleotides increases SIRT1 protein levels and activity, and improves insulin sensitivity in hepatocytes. Ectopic expression of SIRT1 abrogates the effect of miR-181a on insulin sensitivity, and inhibition of SIRT1 activity or SIRT1 deficiency markedly attenuated the improvement in insulin sensitivity induced by antisense miR-181a. In addition, overexpression of miR-181a by adenovirus impairs hepatic insulin signalling, and intraperitoneal injection of locked nucleic acid antisense oligonucleotides for miR-181a improves glucose homeostasis in diet-induced obesity mice.

CONCLUSIONS/INTERPRETATION

miR-181a regulates SIRT1 and improves hepatic insulin sensitivity. Inhibition of miR-181a might be a potential new strategy for treating insulin resistance and type 2 diabetes.

Competitive adsorption of naphthalene with 2,4-dichlorophenol and 4-chloroaniline on multiwalled carbon nanotubes

Competitive adsorption between nonpolar organic compounds and polar ionic organic compounds (IOCs) on carbon nanotubes (CNTs) is essential for application of CNTs as superior sorbents and for environmental risk assessment of both CNTs and organic contaminants. It was observed in this study that adsorption of neutral and dissociated species of polar 2,4-dichlorophenol (DCP) and 4-chloroaniline (PCAN) on a multiwalled CNT sample (MWCNT15) can be suppressed by nonpolar naphthalene. Naphthalene adsorption can also be suppressed by neutral DCP/PCAN, but not dissociated DCP/PCAN. Moreover, competition of naphthalene decreased the adsorption affinity of neutral DCP/PCAN, but not their adsorption capacity because of the formation of solute bilayer on MWCNT15. For dissociated DCP/PCAN, naphthalene not only decreased their adsorption affinity but also their adsorption capacity because no solute bilayer was formed. Neutral DCP/PCAN also decreased the adsorption affinity and adsorption capacity of naphthalene. These observations indicate that competitive adsorption of naphthalene with DCP/PCAN depends on the dissociation of DCP/PCAN, as interpreted by (i) the different sites on CNTs for adsorption of organic chemicals (i.e., naphthalene, and the neutral and dissociated species of DCP/PCAN), (ii) the interactions between organic chemicals, and (iii) the interactions of organic chemicals with CNT surface.

Adsorption and conformation of a cationic surfactant on single-walled carbon nanotubes and their influence on naphthalene sorption

Surfactants are used in synthesis and dispersion of carbon nanotubes (CNTs) and can thus be released into the environment with CNTs. In this study, it was observed that the coupled release of surfactants and CNTs altered the sorption of organic contaminants on the CNTs. The cationic surfactant, cetylpyridinium chloride (CPC), decreased naphthalene sorption on single-walled carbon nanotubes (SWCNT). In the most dramatic example, the adsorption capacity of naphthalene on SWCNT was reduced from 240 to 61.1 mg/g. The decrease of naphthalene sorption could be largely attributed to the competition of adsorbed CPC cations (i.e., C(21)H(38)N(+)) with naphthalene by occupying the SWCNT surface as surfaces decreased from 737 to 88.9 m(2)/g after the coating of CPC. However, the adsorbed CPC may form hemimicelles and result in a favorable media for naphthalene partition to counteract the decrease in naphthalene sorption. Configuration changes of adsorbed CPC hemimicelles might occur because the naphthalene partition into the adsorbed CPC decreased with the increase of adsorbed CPC. A partition-adsorption model was introduced to describe the partition fraction of naphthalene into adsorbed CPC hemimicelles as well as the adsorption fraction of naphthalene on unoccupied surfaces of SWCNT.

Aqueous adsorption of aniline, phenol, and their substitutes by multi-walled carbon nanotubes

Aqueous adsorption of a series of phenols and anilines by a multiwalled carbon nanotube material (MWCNT15), which depends strongly on the solution pH and the number and types of solute groups, was investigated in this study. The pH-dependent adsorption coefficients, Kd, could be predicted by the established models including solute pKa and solution pH values. Phenol or aniline substitution with more groups has higher adsorption affinity, and nitro, chloride, or methyl groups enhanced adsorption in the following order: nitro group > chloride group > methyl group. All adsorption isotherms of nondissociated phenols and anilines are nonlinear and fitted well bythe Polanyi-theory based Dubinin-Ashtakhov (DA) model. Linear quantitative relationships combining DA model parameters (E and b) with solute solvatochromic parameters were developed to evaluate the adsorptive behaviors of nondissociated species. For the saturated sorbed capacity, Q0, the logarithmic values of phenols and anilines were relatively constant with a mean value of 1.90. Besides the van der Waals force, H-bonding interactions from solutes as hydrogen-bonding donors, and followed by pi-electron polarizability, may play important roles on the adsorption of phenols and anilines by carbon nanotubes in the aqueous environment

Rapid activation of ERK1/2 mitogen-activated protein kinase by corticosterone in PC12 cells

Although the nongenomic effects of glucocorticoids have been well acknowledged, its precise intracellular signal transduction pathway remains to be elucidated. The present study using Western immunoblot and protein kinase activity assay, for the first time, showed that corticosterone (B) can induce a rapid activation of Erk1/2 mitogen-activated protein kinase (MAPK) in PC12 cells. The dose-response curve was bell shaped, with the maximal activation at 10(-9) M in 15 min. The results from immunofluorescence staining also revealed that the activated Erk1/2 MAPK was translocated from cytoplasm to nucleus of PC12 cells in 15 min. Activation of Erk1/2 MAPK by B was apparently not mediated by the classical cytosolic steroid receptors, for B-BSA can induce the phosphorylation of Erk1/2 MAPK, but the antagonist (RU38486) cannot block the phosphorylation of Erk1/2 MAPK induced by B. Phosphorylation of Erk1/2 MAPK induced by B was not affected by a tyrosine kinase inhibitor (genistein), suggesting that the pathway did not involve the tyrosine kinase activity. On the other hand, protein kinase C activator (PMA) can activate and protein kinase C inhibitor (Gö6976) can block the activation of Erk1/2 MAPK induced by B. Taken together, these data clearly demonstrated that B might act via putative membrane receptor and rapidly activate Erk1/2 MAPK through protein kinase C alpha in PC12 cells.

[The study of immune effect of nine kinds of recombinant hepatitis B vaccines made in China and foreign countries]

OBJECTIVE

To study the immune effect of nine kinds of recombinant hepatitis B (FIB) vaccines.

METHODS

Immunizing 715 primary school children with four genetically engineered FIB vaccines of 12 batches that were yeast HB vaccine (YDV), Chinese hamster ovary cell HB vaccine (CHO), vaccinia derived vaccine and Hansenula Polymorpha vaccine produced by USA MSD Co, USA Amgen Co, Japan, France, Argentina and Beijing, Changchun, Shenzhen of China. The anti-HBs was tested by RIA (Abbott reagent).

RESULTS

Four kinds of genetically engineered HB vaccines were safe and effective. The peak of the antibody after immunization with Chinese vaccines appeared at the 7th month of the first dose. The geometric mean titre (GMT) of the anti-HBs was higher (393.60 mIU/ml) after immunized by vaccinia derived vaccine, its stability was better than the batches of CHO. The antibody titer descended in a narrow range after immunization of YDV. The vaccine containing 10 microg/dose was superior to 5 microg/dose in antibody persistence. Hansenuly polymorpha vaccine was the first time to study in China, it showed a good immune effect.

CONCLUSIONS

The total immune effect of the recombinant FIB vaccines made no distinction among the products of China and USA, Japan, France and Argentina.

Lysophosphatidylcholine activates p38 and p42/44 mitogen-activated protein kinases in monocytic THP-1 cells, but only p38 activation is involved in its stimulated chemotaxis

Oxidized LDLs (OxLDLs) have been shown to be involved in recruitment of blood monocytes into the arterial subendothelial space, which is the earliest step in atherogenesis, but the underlying molecular mechanisms are poorly understood. The present study demonstrated that lysophosphatidylcholine (LPC), a major phospholipid component of OxLDL, strongly evoked phosphorylation and activation of p38 and p42/44 mitogen-activated protein kinases in monocytic cells. The stimulation of p38 and p42/44 occurred in a dose- and time-dependent manner, reaching the maximal activation at 25 microg/mL LPC within 5 minutes. Interestingly, inhibition of p38 activation by OxLDL or LPC, using its selective inhibitors (SB203580 and SKF86002), completely blocked OxLDL- or LPC-stimulated chemotaxis of THP-1 cells, which was measured in a transwell chemotaxis assay. In contrast, inhibition of p42/44 activation by its potent inhibitor (PD98059) did not block OxLDL- or LPC-stimulated chemotaxis. Moreover, expression of a p38 dominant-negative mutant (p38AF) reduced cell chemotaxis significantly. In addition, activation of p38 by LPC was apparently mediated neither by scavenger receptors nor by tyrosine kinase receptors. It was, however, effectively blocked by pertussis toxin and substantially reduced by phospholipase C inhibitor (U73122) and phosphatidylinositol 3-kinase inhibitors (wortmannin and LY294002). LPC also inhibited forskolin-stimulated cAMP accumulation in a pertussis toxin-sensitive manner, indicating that Gi/Go proteins likely mediated the effects of LPC. Our results suggested that OxLDL/LPC efficiently activated both p38 and p42/44, but only the activation of p38 was functionally associated with OxLDL-/LPC-induced chemotaxis in THP-1 cells.

Identification of a human brain-specific isoform of mammalian STE20-like kinase 3 that is regulated by cAMP-dependent protein kinase

A novel isoform of mammalian STE20-like kinase 3 (MST3) with a different 5' coding region from MST3, termed MST3b, was identified by searching through expressed sequence tag data base and obtained by rapid amplification of cDNA 5'-ends. MST3b was assigned to the long arm of human chromosome 13, D13S159-D13S280, by use of the National Center for Biotechnology Information sequence-tagged sites data base. Reverse transcription-polymerase chain reaction and Northern blot analysis with a probe derived from 5' distinct sequence of MST3b revealed that the expression of MST3b mRNA is restricted to the brain, in contrast to ubiquitous distribution of MST3 transcript. Western analysis confirmed the brain-specific expression of MST3b protein. In situ hybridization of rat brain sections with a MST3b-specific probe indicated that MST3b is widely expressed in different brain regions, with especially high expression in hippocampus and cerebral cortex. When expressed in human embryonic kidney 293 (HEK293) cells, MST3b effectively phosphorylated myelin basic protein, as well as undergoing autophosphorylation. Interestingly, expression of MST3, but not MST3b, in HEK293 cells was able to activate the endogenous p42/44 mitogen-activated protein kinase (MAPK) up to 4-fold, whereas neither isoform activated p38 MAPK under the same conditions. Further experiments demonstrated that MST3b, but not MST3, was effectively phosphorylated by activation of cyclic AMP-dependent protein kinase (PKA) in both in vivo and in vitro assays. The mutation of Thr-18 into Ala in MST3b (T18A), a putative PKA phosphorylation site that is absent in MST3, abolished its phosphorylation by PKA. Consequently, expression of the T18A mutant in HEK293 cells led to partial activation of p42/44 MAPK, indicating that MST3b is under the regulation of PKA. Taken together, our data provide evidence that the two isoforms of STE20-like kinase 3 are differentially distributed and regulated.

Suppression of angiotensin II stimulated responses in aortic vascular smooth muscle cells of experimental cirrhotic rats

Functional responses to angiotensin II (AT-II) were determined in aortic vascular smooth muscle cells (VSMCs) from experimental cirrhotic rats. Our data showed that AT-II-stimulated extracellular acidification rate (ECAR), which was measured by Cytosensor microphysiometry, was significantly reduced in the aortic VSMCs from the cirrhotic rats as compared to those from the control animals. The ability of AT-II to promote formation of inositol phosphates, the second messenger produced by the activation of Gq-coupled receptors, was also considerably suppressed in the cirrhotic VSMCs. Furthermore, the maximal p42/44 MAPK phosphorylation stimulated by AT-II was significantly reduced in the cirrhotic VSMCs in contrast to that in the normal VSMCs. Taken together, our data clearly demonstrated that the functional responses to AT-II was severely suppressed in aortic VSMCs in cirrhosis, indicating the impairment of general Gq-coupled receptor signaling and subsequent biological function in the cirrhotic VSMCs.

Activation of p38 mitogen-activated protein kinase by oxidized LDL in vascular smooth muscle cells: mediation via pertussis toxin-sensitive G proteins and association with oxidized LDL-induced cytotoxicity

Oxidized low-density lipoproteins (oxLDL) have been shown to play a crucial role in atherosclerosis, but the underlying molecular mechanisms have not been fully understood. The present study showed that oxLDL strongly evoked phosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) in rat vascular smooth muscle cells (VSMCs) in concentration- and time-dependent manners, reaching the maximal activation at 100 microg/mL within 5 minutes. The results from immunofluorescence staining also revealed that p38 MAPK was activated by oxLDL in 5 minutes, and the activated p38 MAPK was translocated from cytoplasm to nucleus of VSMCs in 15 minutes. Activation of p38 MAPK by oxLDL was apparently not mediated by their classical scavenger receptors and was not affected by tyrosine kinase inhibitors. However, activation of p38 MAPK was effectively blocked by pretreatment with pertussis toxin and was significantly reduced by phospholipase C inhibitor U-73122. OxLDL also inhibited forskolin-stimulated cAMP accumulation and increased inositol phosphate formation. More interestingly, inhibition of p38 MAPK by its specific inhibitor SB203580 significantly blocked oxLDL-induced cytotoxicity (increased leakage of cytoplasmic lactate dehydrogenase to the culture medium, reduced [3H]thymidine incorporation, and attenuated mitochondrial metabolism of tetrazolium salt, (3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-s ulfophenyl)- 2H-tetrazolium), MTS) in VSMCs, and pretreatment with pertussis toxin also inhibited oxLDL-induced cytotoxicity. Taken together, our data clearly demonstrated that oxLDL effectively activated p38 MAPK in VSMCs, which was likely mediated via pertussis toxin-sensitive G proteins, and the p38 activation was functionally associated with oxLDL-induced cytotoxicity in VSMCs.

[Effects of oncomelania-killing for the total saponins of Phytolacca acinosa]

The total saponins got from the roots of Phytolacca acinosa Roxb were examined about the effect of Oncomelania-killing. The results showed the efficiency was 95.6% controlled the temperature at 28 degrees C and concentration of drugs at 125 mg/L after soaking for 24 h.

[Antibody reaction to immunization with different recombinant hepatitis B vaccine in primary school children]

OBJECTIVE

To evaluate the safety and immunogenicity of local produced hepatitis B (HB) vaccine and to lay a basis for formulating an immunization strategy.

METHODS

Two batches of local produced and two batches of imported yeast derived recombinant HB vaccine (YDV), and four batches of local produced Chinese hamster ovary cell derived recombinant HB vaccine (CHOV) were administered to 550 children in primary schools to study their immunogenicity one year after immunization.

RESULTS

No severe adverse reaction was found in all vaccinee. Positive seroconversion rate was more than 90 percent one month after completion of three-dose immunization with all kinds of HB vaccine mentioned above, and then declined slowly. Titer of antibody against hepatitis B surface antigen (anti-HBs) in those vaccinated with two batches of local produced YDV, except four groups, was significantly lower than that in those with imported YDV and local produced CHOV seven months after first-dose immunization, but no difference between local produced YDV and imported Merck vaccine and CHOV was found one year after immunization. Mean geometric titer (GMT) of anti-HBs reached the peak seven months after immunization in those vaccinated with all batches of HB vaccine except for the YDV imported from Amgen Co. There was no significant difference in positive seroconversion and GMT of anti-HBs between different batches of local produced YDV and CHOV.

CONCLUSION

Safety and immnogenicity of local produced recombinant HB vaccine is as good as those of imported one in immunization for primary school children.

N-Methyl-D-aspartate attenuates opioid receptor-mediated G protein activation and this process involves protein kinase C

The effects of N-methyl-D-aspartate (NMDA) on opioid receptor-mediated G protein activation were explored in neuroblastoma X glioma hybrid (NG108-15) cells. Treatment of the cells with NMDA resulted in a remarkable attenuation of [35S]guanosine-5'-O-(3-thio)triphosphate binding stimulated by [D-Pen2,D-Pen5]-enkephalin (DPDPE), a delta-opioid receptor agonist. The effects of NMDA were dose and time dependent with an IC50 value of 5 nM and could be blocked by NMDA receptor antagonists. After NMDA treatment, the DPDPE dose-response curve shifted to the right (EC50 value increased approximately 7-fold, from 6 to 40 nM), and the maximal response induced by DPDPE was reduced by approximately 60%. The effects of NMDA were reversible, and the DPDPE response could recover within 60 min. The functional responses of delta-, mu-, and kappa-opioid receptors in primarily cultured neurons also were attenuated significantly by NMDA treatment. The inhibitory effects of NMDA on opioid receptor-mediated G protein activation could be blocked by coadministration of the protein kinase C (PKC) inhibitors or by elimination of the extracellular Ca2+. Correspondingly, NMDA treatment of NG108 cells significantly elevated cellular PKC activity and stimulated Gialpha2 phosphorylation. Transient transfection into NG108-15 cells of the wild-type Gialpha2 and a mutated Gialpha2 (Ser144Ala) resulted in a 2-fold increase in DPDPE-stimulated G protein activation. The DPDPE responses were greatly inhibited by NMDA treatment in the wild-type Gialpha2-transfected cells but much less affected in the mutant Gialpha2-transfected cells. In summary, NMDA attenuates opioid receptor/G protein coupling, and this process requires activation of PKC.

[Application of PCR-SSCP to rapid genetic diagnosis of adult polycystic kidney disease]

OBJECTIVE

To explore a rapid and easy-to-do linkage analysis in families with adult polycystic kidney disease(APKD).

METHODS

The polymorphism of SM7, a SRS which lies proximal to PKD1, among Chinese people was analysed using PCR, PAGE and silver staining. SM7-SSLP linkage analyses were performed in two APKD families and the results were compared with these of 3'HVR/Pvu II linkage analyses in the same families.

RESULTS

Seven kinds of SM7 alleles were observed in the 67 unrelated Chinese people. The heterozygosity was 52.5% and PIC 0.62. The most common allele was Y9. The result was close to that of Harris's report, showing that there is no marked difference in the polymorphism of SM7 between Chinese and Caucasian. The results of SM7-SSLP linkage analyses in the two APKD families consisted with the results of 3'HVR/Pvu II linkage analyses though in one family the information provided by SM7 was less than 3'HVR.

CONCLUSION

The polymorphism of SM7 locus is high in Chinese and SM7 can be used in linkage analysis as a valuable marker. SSLP linkage analysis proved to be avery useful way for rapid genetic diagnosis of APKD providing that a highly polymorphic marker is used, and the result can be analysed easily.

[The application of D1S80 locus analysis to forensic problems by using Amp-FLP technique]

This is a paper on paternity testing in 85 test cases and the identification of individuals from mixed stains of semen and vaginal secretion in two rape cases. We used primers flanking the hypervariable region of the D1S80 gene to amplify DNA extracted from fresh blood, blood stain, saliva stain, semen stain, mixed stain in vaginal swab, and from fetal tissues. The results revealed that 35 out of 85 alleged fathers in 85 paternity testing cases were excluded. In 30 of the 35 excluded cases, the alleged fathers were excluded by D1S80 locus analysis. The exclusion rate was 35.29%. In 2 of the excluded cases, the alleged fathers were excluded by D1S80 locus analysis only. In 50 nonexcluded paternity testing cases, the paternity index(PI) of D1S80 locus was 2. 0576-111.1111. It indicates that D1S80 locus analysis plays an important role in elevation the relative chance of paternity (RCP) value. In 41 of the 50 nonexcluded cases, RCP was higher that 99.75%. RCP reached 99.300%-99.649% in 9 of cases. In one rape and homicide case, the genotype of D1S80 locus of sperm on the vaginal swab was detected. It gave a clue to investigation. In the other rape case, the genotype of D1S80 of sperm on the vaginal swab was consistent with the blood stain from the suspect. So the suspect was not excluded. Since the D1S80 locus has a high discrimination power it is very useful for forensic individual identification and parentage testing. Some problems have been discussed in this paper.

Comparison of personality traits of only and sibling school children in Beijing

The number of only children in China has increased rapidly since the late 1970s, when the Chinese government advocated the "one-child-per-family" policy. This increase has caused much public concern about the healthy growth of the young generation. In this study the behavioral traits of Chinese, urban, only children were investigated. The participants were 444 children with siblings and 473 only children from Grades 1, 3, and 5 in Beijing primary schools. An inventory consisting of 27 items covering three behavioral traits was developed. The children were rated on the inventory by the principal teacher of the class. Factor analysis revealed three main factors: achievement motivation, interpersonal skills, and attitude toward manual labor. The only children exceeded the sibling children on achievement motivation. No differences were found between only children and sibling children on interpersonal skills and attitude toward manual labor. Gender differences were evident; girls consistently received higher ratings on achievement motivation and interpersonal skills. The possible underlying reasons for these differences are discussed.

The Chinese single-child family programme and population psychology

Following the Chinese population explosion in the early 1950s and late 1960s, the implementation of the single-child family planning programme in the 1970s caused a drastic decline in the natural growth rate of population in China. In this paper demographic data are presented to show population growth at various periods in Chinese history. The socio-psychological effects and problems encountered in the administration of the Chinese single-child family policy in recent decades are discussed. A population cycle caused by the abrupt change in population may last for 60 to 80 years until the mid-21st century. Around A.D. 2010 when there will be about equal number of children and old people in the Chinese society, a dilemma betweenparental investment and successor's investment may occur. The long-term consequence of the single-child family policy would be an aged society with more elders than children in society. A support system must therefore be designed as a mechanism to keep the Chinese three generation family system intact to care for the old. Grandparenting is suggested as a means to maintain inter-dependence in the family to cope with the dynamics of the changing inter-generation patterns. Classical Confucian ideology is considered important to maintain the traditional Chinese social institutions and ethical values.

Physical, achievement and personality characteristics of Chinese children

The physical, achievement, and personality characteristics of Chinese schoolchildren are evaluated. The results of two surveys of Chinese schoolchildren, conducted in Beijing and Jilin Province, are presented. In the Beijing sample, the differences between only children and others were small but statistically significant, with the only children having higher scores in achievement and physical size. In the Jilin Province sample, the differences between only children and others were also small but significant. These differences were found entirely in physical characteristics, with only children being smaller, perhaps because the only children in the Jilin sample were much younger than the non-only children. Analyses of the combined sample of Beijing and Jilin schoolchildren indicated that the only-child advantages in achievement were found among children from urban families, not rural peasant families. While significant differences in height and weight were found in all three samples, none of the results indicated a significant difference in the proportion of body fat. None of the analyses indicated that only children had undesirable personalities, as judged by teachers and mothers.