[Full Sibling Identification by IBS Scoring Method and Establishment of the Query Table of Its Critical Value]

OBJECTIVES

To establish a query table of IBS critical value and identification power for the detection systems with different numbers of STR loci under different false judgment standards.

METHODS

Samples of 267 pairs of full siblings and 360 pairs of unrelated individuals were collected and 19 autosomal STR loci were genotyped by Goldeneye™ 20A system. The full siblings were determined using IBS scoring method according to the 'Regulation for biological full sibling testing'. The critical values and identification power for the detection systems with different numbers of STR loci under different false judgment standards were calculated by theoretical methods.

RESULTS

According to the formal IBS scoring criteria, the identification power of full siblings and unrelated individuals was 0.764 0 and the rate of false judgment was 0. The results of theoretical calculation were consistent with that of sample observation. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci was successfully established.

CONCLUSIONS

The IBS scoring method defined by the regulation has high detection efficiency and low false judgment rate, which provides a relatively conservative result. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci provides an important reference data for the result judgment of full sibling testing and owns a considerable practical value.

Role and timing of second-line therapies for patients with recurrent platinum-resistant ovarian epithelial cancer

OBJECTIVE

To explore the regimens and prognoses of second-line therapies for recurrent platinum-resistant ovarian epithelial cancer (OEC).

MATERIALS AND METHODS

The clinical profiles and second-line regimens were retrospectively analyzed for 65 recurrent platinum-resistant OEC patients treated at Zhejiang Provincial Tumor Hospital during January 2003 to January 2013. In conjunction with literature reviews, the second-line therapies for platinum-resistant recurrent OEC were discussed.

RESULTS

Their average age was 55.2 years. The stages were I (n=4), II (n=3), III (n=45), and IV (n=13). The predominant type was serous adenocarcinoma (n=47, 72.3%). Chemotherapy was refused (n=14) and resistant (n=5 1). One case was lost to follow-up and another three withdrew early. An average of four chemotherapeutic courses were offered in 61 cases. Among them, five cases selected chemotherapy after a second operation. The average therapy-free interval (TFI) was 3.5 months. The efficacies were evaluated for 61 cases. CR (n=5) and partial remission (PR, n=22). The overall survival (OS) rate was 43.6% and average progression-free survival (PFS) was 15.44 months.

CONCLUSION

The efficacy of second-line therapy for recurrent platinum-resistant OEC is rather poor and the feasibility and efficacy of second operation are to be further explored.

Evaluation of Cellular Antioxidant and Antiproliferative Activities of Five Main Phyllanthus Emblica L. Cultivars in China

The cell-based antioxidant activity assay as more biological relevant assay was considered to be more accurate to predict antioxidant activity in vivo than chemical activity assays. In the present study, the five main Phyllanthus emblica L. cultivars in China were subjected for cellular antioxidant activity based on HepG2 cells as well as antiproliferative activity. Total phenolics, total flavonoids and oxygen radical absorbance capacity were also measured. The results showed that Qingyougan, Binggan and Boligan (832±100, 774±52 and 704±28 μmol of quercetin equivalents/100 g) had higher cellular antioxidant activity than Tianyougan and Yougan (553±50 and 457±24 μmol of quercetin equivalents/100 g) in phosphate buffered saline wash protocol whereas, Boligan (3735±217 μmol of quercetin equivalents/100 g) had the highest cellular antioxidant activity and Tianyougan (2025±171 μmol of quercetin equivalents/100 g) had the lowest cellular antioxidant activity in no phosphate buffered saline wash protocol. The highest and lowest antiproliferative activities were observed in Binggan and Tianyougan (median effective dose: 6.95±0.11 and 14.03±0.10 mg/ml), respectively. The significant correlation was only observed between total flavonoids and cellular antioxidant activity from no phosphate buffered saline wash protocol (R(2) =0.908, P<0.05), and total flavonoids and antiproliferative activity (R(2) =0.887, P<0.05), suggesting the major contribution of flavonoids to the bioactivities of emblica. Overall, the data obtained revealed that different Phyllanthus emblica L. cultivars had strong cellular antioxidant and antiproliferative activities, thus should be recommended to increase consumption for health.

[Decline of ATP-binding cassette transporter G1 expressions with a liver X receptor-independent pathway in patients with type 2 diabetes]

OBJECTIVE

To examine the cholesterol efflux and the expressions of ATP-binding cassette transporter G1 (ABCG1) in macrophages of diabetic patients and the roles of liver-X receptor (LXR) in regulation of ABCG1 expressions.

METHODS

Blood was collected from patients with type 2 diabetes mellitus and healthy controls. The peripheral blood monocytes were differentiated into macrophages with macrophage colony stimulating factor (M-CSF). The cells were radio labeled with [(3)H] cholesterol and were performed with cholesterol efflux assays. Quantitative real-time PCR (qRT PCR) and Western blot were performed to measure the mRNA and protein expressions of ABCA1 and ABCG1. To test the effects of LXR on ABCG1 expressions, inhibition of LXRα and LXRβ by siRNA were performed. The DNA-protein complex of LXR and LXR element (LXRE) located in the promoter region of ABCG1 gene were detected with electrophery mobility supershift assay (EMSA).

RESULTS

Macrophage ABCG1 expressions and high-density lipoprotein (HDL) induced cholesterol efflux were significantly reduced (19.0%±1.2% vs. 12.8%±3.6%, t=2.532, P=0.016) in the diabetic subjects whereas ABCA1 expressions and apolipoprotein A1 (ApoA1) induced cholesterol efflux were comparable (12.0%±1.2% vs. 10.2%±2.3%, t=1.771, P=0.109) between the diabetic patients and healthy subjects. The mRNA expressions of LXRα and LXRβ had no changes between the diabetes subjects and healthy controls (t=1.025, P=0.315; t=-0.531, P=0.600). The LXR-LXRE DNA-protein complex detected by EMSA were also similar between the diabetes subjects and healthy controls (t=1.483, P=0.164). Moreover, ABCG1 expressions were not altered by inhibition of LXRα/β siRNA (t=2.143, P=0.061).

CONCLUSION

Our data indicated that expression of ABCG1 and HDL induced cholesterol efflux were reduced in type 2 diabetic patients. However, the LXR mRNA expression and binding complex of LXR and ABCG1 promoter were not changed. The impairment of cholesterol efflux and ABCG1 gene expressions might be regulated via an LXR-independent pathway.

Summer Blight of White Clover (Trifolium repens) Caused by Rhizoctonia solani AG-1-IB in China

White clover (Trifolium repens), also known as Dutch clover (family Fabaceae), is an herbaceous, perennial plant, widely planted as pasture crop and occasionally used as lawn plant. From June to September in 2012 and 2013, approximately 5 to 8% of the plants as garden lawn were infected in the areas surveyed in Tonghua County, Jinlin Province. Ash green and water-soaked lesions appeared initially on the petiole and leaves. Subsequently, petioles collapsed with soft watery rot followed by collapse of leaves and eventually the entire plant. Aerial hyphae appeared on all the infected parts, followed by production of light brown to brown sclerotia. Seven isolates with the morphological characteristics of Rhizoctonia solani Kühn were isolated from symptomatic petioles and leaves which were surface disinfested in 70% alcohol for 30 s and 0.5% sodium hypochlorite for 1 min and plated on potato dextrose agar (PDA). Hyphal tips were transferred to a fresh plate of PDA and the cultures were examined for morphological characters microscopically. Mycelia of all isolates were branched at right angles with a septum near the branch and a slight constriction at the branch base. Hyphal cells were determined to be multinucleate when stained with 1% safranin O and 3% KOH solution (1) and examined at 400× magnification with a microscope. The internal transcribed spacer (ITS) region of the nuclear rDNA was amplified by using the primers ITS4 and ITS5 (2). The ITS sequences of isolates BSYJ₁₄ (GenBank Accession No. HF678123), BSYJ₃₁ (HF571130), BSYY₂₁ (HF678126), and BSY₂₂ (KC572140) exhibited 100% identity with that of R. solani AG 1-1B (AB122138 and HQ185364). ITS sequences of another three isolates, BSYJ₁₁ (HF678122), BSYJ₃₂ (HF678125), and BSYJ₁₂ (HF678121) exhibited 99% identity with the ITS sequence of R. solani AG 1-1B. Pathogenicity tests were performed on healthy, potted T. repens. Five potted plants were inoculated at the base of the petiole with a 0.6-cm diameter mycelial plug from 3-day-old PDA cultures for each isolate, and the inoculation sites were covered with moistened sterile absorbent cotton. Another five potted plants were inoculated with sterile PDA plugs as controls. All plants in the experiments were covered with plastic bags and kept in a greenhouse at 20 to 25°C for 72 h, then the plastic bags were removed. After 5 to 7 days, the symptoms of watery rot were observed on petioles and leaves of all plants inoculated with these isolates, while control plants remained healthy. R. solani AG 1-IB was re-isolated from all plants inoculated with the isolates. The isolates were confirmed by morphological characteristics of the hyphae and hyphal fusions with the original isolates. The pathogenicity test was carried out twice with similar results. R. solani has been reported to cause root rot on T. pratense in northwestern China (4) and summer blight on T. pratense in Japan (3). To our knowledge, this is the first report of R. solani AG 1-IB causing summer blight on T. repens in China. References: (1) R. J. Bandoni. Mycologia 71:873, 1979. (2) D. E. L. Cooke et al. Mycol. Res. 101:667, 1997. (3) T. Tsukiboshi et al. Bull. Natl. Grassl. Res. Inst. 39:50, 1988. (4) W.-Y. Zhuang (ed.). Fungi of Northwestern China. Mycotaxon Ltd. Ithaca, NY, 2005.

Gene expression analysis of host spleen responses to Marek's disease virus infection at late tumor transformation phase

Marek's disease is a viral neoplastic disease of chickens caused by Marek's disease virus (MDV). Gene expression patterns have been investigated at different MDV infection stages, but there is limited research about the late tumor transformation phase. In this experiment, 44K Agilent chicken genome-wide expression microarrays were used to profile differential expression in tumorous spleens (TS) from severely morbid chickens and apparently normal spleens from survivors (SS) after MDV infection and expression in noninfected spleens (NS) from controls. There were 4,317 differentially expressed (DE) genes in TS versus NS. However, no DE genes were detected in SS versus NS, suggesting that maintenance of, or return to, homeostasis of gene activity in survivor spleens. Downregulated genes in tumorous spleens mainly enriched in the cytokine-cytokine receptor interaction pathway, and commonly investigated genes in Marek's disease study, IL6, IL18, IFNA, and IFNG were nondifferentially expressed, which indicates host inflammatory response was impaired. The IL10 and TNFRSF8 genes were upregulated in tumorous spleens. We speculated that IL10 might be exploited by MDV to escape from host immune surveillance, as reported for Epstein-Barr virus, which stimulated T cells secreting IL10 to subvert immune response. Previous study reported that transcription from TNFRSF8 promoter could be enhanced by MDV oncogene Meq. In this study, the increased expression of TNFRSF8 indicated interaction between MDV and TNFRSF8, which might facilitate pathogenesis and tumor transformation. The expression of many members in IGF system was changed in tumorous compared with noninfected spleens. The downregulation of IGFBP7 was considered to be associated with MD lymphoma transformation. Gene expression change of multiple regulatory pathways indicated their involvements in facilitating tumor transformation.

A molecular dynamics investigation on the crizotinib resistance mechanism of C1156Y mutation in ALK

Crizotinib is an anaplastic lymphoma kinase (ALK) inhibitor that has recently been approved in the US for the treatment of non-small cell lung carcinoma (NSCLC). Despite its outstanding safety and efficacy, several resistant mutations against crizotinib have been detected in the treatment of NSCLC. However, in contrast to the widely accepted mechanism of steric hindrance by mutations at the active site, the mechanism by which the C1156Y non-active site mutation confers resistance against crizotinib remains unclear. In the present study, the resistance mechanism of C1156Y in ALK was investigated using molecular dynamics simulations. The results suggest that despite the non-active site mutation, C1156Y causes the dislocation of crizotinib as well as the indirect conformational changes in the binding cavity, which results in a marked decrease in the van der Waals and electrostatic interactions between crizotinib and ALK. The obtained results provide a detailed explanation of the resistance caused by C1156Y and may give a vital clue for the design of drugs to combat crizotinib resistance.

Atomic ordering kinetics of FePt thin films

In the present study, the nucleation and growth kinetics of the L1(0) ordered domains in FePt thin films were studied by using X-ray diffraction (XRD) measurements combined with transmission electron microscopy (TEM). A small nucleation activation energy En = (0.5 +/- 0.1) eV and a relatively large growth activation energy Eg = (0.9 +/- 0.1) eV for the L1(0) ordered domains are separately determined. The high ratio Eg/En > 1 yields an understanding of a high L1(0) ordering temperature for the FePt thin films used for magnetic recording media.

Calcium-permeable presynaptic kainate receptors involved in excitatory short-term facilitation onto somatostatin interneurons during natural stimulus patterns

Schaffer collateral synapses in hippocampus show target-cell specific short-term plasticity. Using GFP-expressing Inhibitory Neuron (GIN) transgenic mice that express enhanced green fluorescent protein (EGFP) in a subset of somatostatin-containing interneurons (SOM interneurons), we previously showed that Schaffer collateral synapses onto SOM interneurons in stratum (S.) radiatum have unusually large (up to 6-fold) paired-pulse facilitation. This results from a low initial release probability and the enhancement of facilitation by synaptic activation of presynaptic kainate receptors. Here we further investigate the properties of these kainate receptors and examine their effects on short-term facilitation during physiologically derived stimulation patterns, using excitatory postsynaptic currents recorded in S. radiatum interneurons during Schaffer collateral stimulation in acute slices from juvenile GIN mice. We find that GluR5 and GluR6 antagonists decrease short-term facilitation at Schaffer collateral synapses onto SOM interneurons with no additive effects, suggesting that the presynaptic kainate receptors are heteromers containing both GluR5 and GluR6 subunits. The calcium-permeable receptor antagonist 1-napthyl acetyl spermine (NASPM) both mimics and occludes the effect of the kainate receptor antagonists, indicating that the presynaptic kainate receptors are calcium permeable. Furthermore, Schaffer collateral synapses onto SOM interneurons show up to 11-fold short-term facilitation during physiologically derived stimulus patterns, in contrast to other interneurons that have less than 1.5-fold facilitation. Blocking the kainate receptors reduces facilitation in SOM interneurons by approximately 50% during the physiologically derived patterns and reduces the dynamic range. Activation of calcium-permeable kainate receptors containing GluR5/GluR6 causes a dramatic increase in short-term facilitation during physiologically derived stimulus patterns, a mechanism likely to be important in regulating the strength of Schaffer collateral synapses onto SOM interneurons in vivo.

Non-Markovian quantum jump with generalized Lindblad master equation

The Monte Carlo wave function method or the quantum-trajectory-jump approach is a powerful tool to study dissipative dynamics governed by the Markovian master equation, in particular for high-dimensional systems and when it is difficult to simulate directly. We extend this method to the non-Markovian case described by the generalized Lindblad master equation. Two examples to illustrate the method are presented and discussed. The results show that the method can correctly reproduce the dissipative dynamics for the system. The difference between this method and the traditional Markovian jump approach and the computational efficiency of this method is also discussed.

Biomembrane mimetic polymer poly (2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) at the interface of polyurethane surfaces

Polyurethane (PU) is widely used to make artificial heart and blood vessel wells; however, its thrombogenicity in vivo is still in question. The biomembrane-mimetic and water-soluble polymers, poly (2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB), were used to modify polyurethane (PU) surfaces for improving their hemocompatibility. The morphologies of the PMB modified PU surfaces were examined by using atomic force microscopy and the parameters of the PMB absorption kinetics were extracted from dynamic water contact angle measurements. Two-phase domains, the hard and soft segment phases, were observed on the PU surfaces under the aqueous conditions. The absorbed PMB molecules formed the isolated layers first on the hydrophobic hard segments, and subsequently networked as the PMB concentration increased. The increments of PMB concentration led to the decrement of the effective molar activation (wetting) free energy DeltaG.

Myostatin expression in ventricular myocardium in a rat model of volume-overload heart failure

BACKGROUND

Mechanical stress increases myocardial myostatin expression. However, the expression of myostatin in chronic heart failure resulting from volume-overload and after treatment with beta-blockers is little known. The authors hypothesize that myostatin plays a role in the failing myocardium because of volume-overload.

MATERIALS AND METHODS

Aorto-caval shunt was created over a 4-week period in adult Sprague-Dawley rats to induce volume-overload heart failure.

RESULTS

Heart weight and body weight ratio significantly increased after shunting. The left ventricular end-diastolic dimension also significantly increased. Treatment with carvedilol in the shunt group reversed the increase in heart weight and ventricular dimension to the baseline values. Myocardial and skeletal myostatin proteins were up-regulated in the shunt group. The mRNA of myocardial myostatin also increased in the shunt group. Treatment with carvedilol reversed both protein and mRNA of myocardial myostatin to the baseline values. Treatment with N-acetylcysteine and doxazosin partially decreased myostatin mRNA and protein expression as compared with the shunt group. Carvedilol normalized the increased immunohistochemical labelling of myocardial myostatin in the shunt group.

CONCLUSION

Myocardial myostatin mRNA and protein expression were up-regulated in the rat model of volume-overload heart failure. Treatment with carvedilol is associated with a limitation of increased myostatin expression in the failing ventricular myocardium.

Comparison of haemodynamic responses to orotracheal intubation with GlideScope® videolaryngoscope and fibreoptic bronchoscope

BACKGROUND AND OBJECTIVE

The GlideScope videolaryngoscope is a newly developed laryngoscope for tracheal intubation recently introduced into clinical anaesthesia. In this randomised clinical study, we compared the haemodynamic responses to orotracheal intubation using a GlideScope videolaryngoscope and a fibreoptic bronchoscope.

METHODS

Fifty-six adult patients, ASA I-II scheduled for elective plastic surgery under general anaesthesia requiring orotracheal intubation were randomly allocated to either the GlideScope videolaryngoscope group or the fibreoptic bronchoscope group. After a standard intravenous anaesthetic induction, orotracheal intubation was performed. Noninvasive blood pressure and heart rate were recorded before and after induction, at intubation and for 5 min after intubation at 1 min intervals.

RESULTS

As compared with the post-induction values the orotracheal intubations using a fibreoptic bronchoscope and a GlideScope videolaryngoscope resulted in the significant increases in blood pressures which did not exceed their baseline values. In the two groups, heart rates at intubation and within 2 min after intubation were significantly higher than their baseline values. However, there were no significant differences in blood pressures and heart rates at all time points, their maximal values and maximal percent changes during the observation and the times required to reach their maximal values between the two groups.

CONCLUSIONS

The orotracheal intubations using a fibreoptic bronchoscope and a GlideScope videolaryngoscope produce similar haemodynamic responses.

Blood pressure and heart rate changes during intubation: a comparison of direct laryngoscopy and a fibreoptic method

Blood pressure and heart rate changes during nasotracheal intubation under general anaesthesia were studied in 100 patients who were randomly allocated to fibreoptic bronchoscope or direct laryngoscopy intubation. Noninvasive blood pressure and heart rate were recorded before and immediately after anaesthesia induction, at anaesthesia intubation and every minute thereafter for 5 min. Nasotracheal intubation was accompanied by significant increases in blood pressure and heart rate compared to baseline values in both groups. Blood pressure and heart rate at intubation, and the maximum values of blood pressure during the observation were significantly higher in the fibreoptic bronchoscope group. However, the maximum values of heart rate were not significantly different between the two groups. Fibreoptic nasotracheal intubation may result in more severe pressor and tachycardiac responses than direct laryngoscopic nasotracheal intubation.

Characterization of Cryptocaryon irritans isolates from marine fishes in Mainland China by ITS ribosomal DNA sequences

Seven isolates of Cryptocaryon irritans from different host species and geographical locations in Mainland China were characterized by the first (ITS-1) and second (ITS-2) internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA) using two isolates of Ichthyophthirius multifiliis for comparative purposes. The rDNA region including the ITS-1, 5.8S, ITS-2, and flanking 18S and 28S sequences were amplified by polymerase chain reaction and the amplicons were sequenced directly. The ITS-1, 5.8S, and ITS-2 sequences were 129, 160, and 190 bp in length, respectively, for all seven C. irritans isolates, whereas the corresponding sequences for the two I. multifiliis isolates were 142, 153, and 194 bp, respectively. While sequence variation among the seven C. irritans isolates ranged from 0 to 1.6% in both the ITS-1 and ITS-2, and the two I. multifiliis isolates differed by 1.4% in the ITS-1 and 1.0% in the ITS-2; C. irritans differed from I. multifiliis by 57.1-60.9% in the ITS-1 and 79.4-83.0% in the ITS-2, indicating that ITS sequences provide reliable genetic markers for the identification and differentiation of the two species. Phylogenetic analysis using the sequence pairwise-distance data using the neighbor-joining method inferred that the seven C. irritans isolates from Mainland China and two other isolates (T.A and Aus.C) from other countries clustered together to show monophyly, which could be readily distinguished from the other monophyletic group all from other regions. Therefore, ITS sequence data and phylogenetic analysis provided strong support that C. irritans isolates from Mainland China represent a single species. The definition of genetic markers in the ITS rDNA provide opportunities for studying the ecology and population genetic structures of the C. irritans from Mainland China and elsewhere and is also relevant to the diagnosis and control of fish diseases they cause.

Thermochemical and Kinetic Analyses on Oxidation of Isobutenyl Radical and 2-Hydroperoxymethyl-2-propenyl Radical

In recognition of the importance of the isobutene oxidation reaction in the preignition chemistry associated with engine knock, the thermochemistry, chemical reaction pathways, and reaction kinetics of the isobutenyl radical oxidation at low to intermediate temperature range were computationally studied, focusing on both the first and the second O2 addition to the isobutenyl radical. The geometries of reactants, important intermediates, transition states, and products in the isobutenyl radical oxidation system were optimized at the B3LYP/6-311G(d,p) and MP2(full)/6-31G(d) levels, and the thermochemical properties were determined on the basis of ab initio, density functional theory, and statistical mechanics. Enthalpies of formation for several important intermediates were calculated using isodesmic reactions at the DFT and the CBS-QB3 levels. The kinetic analysis of the first O2 addition to the isobutenyl radical was performed using enthalpies at the CBS-QB3 and G3(MP2) levels. The reaction forms a chemically activated isobutenyl peroxy adduct which can be stabilized, dissociate back to reactants, cyclize to cyclic peroxide-alkyl radicals, and isomerize to the 2-hydroperoxymethyl-2-propenyl radical that further undergoes another O2 addition. The reaction channels for isomerization and cyclization and further dissociation on this second O2 addition were analyzed using enthalpies at the DFT level with energy corrections based on similar reaction channels for the first O2 addition. The high-pressure limit rate constants for each reaction channel were determined as functions of temperature by the canonical transition state theory for further kinetic model development.

Bacterial community structure and diversity in a century-old manure-treated agroecosystem

Changes in soil microbial community structure and diversity may reflect environmental impact. We examined 16S rRNA gene fingerprints of bacterial communities in six agroecosystems by PCR amplification and denaturing gradient gel electrophoresis (PCR-DGGE) separation. These soils were treated with manure for over a century or different fertilizers for over 70 years. Bacterial community structure and diversity were affected by soil management practices, as evidenced by changes in the PCR-DGGE banding patterns. Bacterial community structure in the manure-treated soil was more closely related to the structure in the untreated soil than that in soils treated with inorganic fertilizers. Lime treatment had little effect on bacterial community structure. Soils treated with P and N-P had bacterial community structures more closely related to each other than to those of soils given other treatments. Among the soils tested, a significantly higher number of bacterial ribotypes and a more even distribution of the bacterial community existed in the manure-treated soil. Of the 99 clones obtained from the soil treated with manure for over a century, two (both Pseudomonas spp.) exhibited 100% similarity to sequences in the GenBank database. Two of the clones were possible chimeras. Based on similarity matching, the remaining 97 clones formed six major clusters. Fifty-six out of 97 were assigned taxonomic units which grouped into five major taxa: alpha-, beta-, and gamma-Proteobacteria (36 clones), Acidobacteria (16 clones), Bacteroidetes (2 clones), Nitrospirae (1 clone), and Firmicutes (1 clone). Forty-one clones remained unclassified. Results from this study suggested that bacterial community structure was closely related to agroecosystem management practices conducted for over 70 years.

Activated polymorphonuclear leukocytes induce cardiomyocyte apoptosis and the protective effects of carvedilol

Previous studies have shown that ischemia and reperfusion are potent stimuli for eliciting cardiomyocyte apoptosis, and that polymorphonuclear leukocytes (PMNs) are involved in the development of myocardial injury induced by ischemia and reperfusion. The present study examined whether PMN could directly induce cardiomyocyte apoptosis and, if so, it possible signal transduction pathways. In addition, we also investigated the effects of carvedilol, a potent antioxidant, on PMN-induced apoptosis. Cultured primary neonatal rat cardiomyocytes were exposed to PAF-activated PMNs at concentrations of 10(5), 3 x 10(5) and 10(6) cells/well for 48 h. Multiple detecting techniques, including electron microscopy, DNA gel electrophoresis. TUNEL assay and flow cytometry were used to identify myocyte apoptosis. All of these techniques demonstrated that activated PMNs directly induced cardiomyocyte apoptosis in a concentration-dependent manner, while unactivated PMNs showed no such effect. Activated PMN-induced apoptosis was partially inhibited by SB203580, a specific inhibitor of the p38-MAPK signaling system. Carvedilol (at a dose range of 1-10 mumol/l) significantly prevented activated PMN-induced cardiomyocyte apoptosis. These results suggest that PMNs, when activated, directly induce cardiomyocyte apoptosis and that the p38-MAPK signaling pathway might be involved in this process. Carvedilol may prevent PMN-induced apoptosis possibly because of its antioxidant properties.

Gene construction, expression, and characterization of double-copy truncated form of human insulin-like growth factor I

AIM

To increase the production of recombinant truncated form of insulin-like growth factor I [des(1-3)IGF-I], purify the expressed product, and compare its bioactivity with that of standard IGF-I.

METHODS

The second copy of des(1-3)IGF-I gene was inserted into the previously constructed pExSec1/IGF-I to form a pExSec1/2(IGF-I) expression plasmid, then the plasmid was transformed into a protease-deficient E coli strain BL21(DE3). The engineered bacteria were cultured and induced by IPTG at 12 degrees C. The expressed product was purified through ultrafiltration and Sephadex G-50 gelfiltration. The bioactivity of the preliminarily purified protein was tested by MTT method and compared with standard IGF-I.

RESULTS

The amount of des(1-3)IGF-I expressed by pExSec1/2(IGF-I) reached up to 20 % of the total soluble bacterial protein, which was higher than the amount (12 %) expressed by a single copy of pExSec1/IGF-I gene. The purity of recombinant des(1-3)IGF-I reached 49 % and 82 % after ultrafiltration and gelfiltration. The bioactivity of des(1-3)IGF-I after gelfiltration was about 77 % of standard IGF-I at the same concentration.

CONCLUSION

The yield of recombinant des(1-3)IGF-I was increased about 8 % by construction of expression plasmid with two copies of des(1-3)IGF-I gene compared with only one copy of gene, and preliminarily purified des(1-3)IGF-I showed about 77 % bioactivity compared with standard IGF-I.

[Isokinetic concentric dynamometry of knee flexors and extensors in young male]

Objective. To investigate the effects of different moving speeds on isokinetic dynamometry of knee flexors and extensors, and to provide normative data for comparative purposes in strength evaluations. Method. Thirty healthy male were tested at 60, 180, and 240 deg/sec angular velocities using a REV9000 testing and rehabilitation system. Result. Both PT (peak torque) and PT/BW (peak torque/body weights) showed significant differences (P< 0.01, P< 0.05) between flexors and extensors, and declined significantly with increased speed (P< 0.001). Peak torque differences between dominant and nondominant knee (Di%) was 10%. TPT (time to peak torque) tended to decrease as moving speeds increased (P< 0.001). APT (angle of peak torque) were 50%-70% for quadriceps, and 32%-45% for hamstrings; H/Q (hamstrings peak torque/quadriceps peak torque) was 50%-60%; WF (work fatigue) was 65%. Conclusion. The results provided a reference for strength evaluations in space medicine and space physiology, especially under simulated weightlessness and microgravity.