Growth Difference between CNE-2 and S-18 Cell Lines after Subcutaneous Xenograft / 昆明医科大学学报

Objective To study the growth difference and possible mechanism between nasopharyngeal carcinoma (NPC) cell line CNE-2 and its subclone S-18.Methods CNE-2 and S-18 cells were cultured in vitro.6 x 105 cells/mouse were xenografted subcutaneously in the back of nude mice.The volumes of rumors were measured on the 3 rd,7 th,10 th,14 th day after grafting.Mice were sacrificed on the 14 th day and tumors were isolated and weighed.RNA from tumor tissues were extracted and transcriptional levels of HSP27 and NF-K B were detected.Results (1) S-18,instead of CNE-2,grew to form tumor mass 7 days after xenografting subcutaneously;both cell lines formed tumor mass 10 days after xenografting,however,the volumes of S-18 tumors [(223.13 ± 21.32) mm3,10 th day;(420.25 ± 24.52) mm3,14 th day] were significant bigger than CNE-2tumors [(113.70±11.70) mm3,10thday;(279.86±25.78) mm3,14thday];The weights of S-18 umors were significantly higher than CNE-2 tumors on the 14 th day after xenografting;(2) The transcriptional levels of HSP27 and NF-KB in S-18 tumor were significantly higher than in CNE-2 tumor.Conclusion Xenografted S-18 NPC grows faster than Xenografted CNE-2 NPC.HSP27 and NF-κ B are probably involved in the regulation of growth in NPC.

Scorpion toxin BmK I directly activates Nav1.8 in primary sensory neurons to induce neuronal hyperexcitability in rats

Voltage-gated sodium channels (VGSCs) in primary sensory neurons play a key role in transmitting pain signals to the central nervous system. BmK I, a site-3 sodium channel-specific toxin from scorpion Buthus martensi Karsch, induces pain behaviors in rats. However, the subtypes of VGSCs targeted by BmK I were not entirely clear. We therefore investigated the effects of BmK I on the current amplitude, gating and kinetic properties of Nav1.8, which is associated with neuronal hyperexcitability in DRG neurons. It was found that BmK I dose-dependently increased Nav1.8 current in small-sized (<25 μm) acutely dissociated DRG neurons, which correlated with its inhibition on both fast and slow inactivation. Moreover, voltage-dependent activation and steady-state inactivation curves of Nav1.8 were shifted in a hyperpolarized direction. Thus, BmK I reduced the threshold of neuronal excitability and increased action potential firing in DRG neurons. In conclusion, our data clearly demonstrated that BmK I modulated Nav1.8 remarkably, suggesting BmK I as a valuable probe for studying Nav1.8. And Nav1.8 is an important target related to BmK I-evoked pain.

Exploring the obscure profiles of pharmacological binding sites on voltage-gated sodium channels by BmK neurotoxins

Diverse subtypes of voltage-gated sodium channels (VGSCs) have been found throughout tissues of the brain, muscles and the heart. Neurotoxins extracted from the venom of the Asian scorpion Buthus martensi Karsch (BmK) act as sodium channel-specific modulators and have therefore been widely used to study VGSCs. α-type neurotoxins, named BmK I, BmK αIV and BmK abT, bind to receptor site-3 on VGSCs and can strongly prolong the inactivation phase of VGSCs. In contrast, β-type neurotoxins, named BmK AS, BmK AS-1, BmK IT and BmK IT2, occupy receptor site-4 on VGSCs and can suppress peak currents and hyperpolarize the activation kinetics of sodium channels. Accumulating evidence from binding assays of scorpion neurotoxins on VGSCs, however, indicate that pharmacological sensitivity of VGSC subtypes to different modulators is much more complex than that suggested by the simple α-type and β-type neurotoxin distinction. Exploring the mechanisms of possible dynamic interactions between site 3-/4-specific modulators and region- and/or species-specific subtypes of VGSCs would therefore greatly expand our understanding of the physiological and pharmacological properties of diverse VGSCs. In this review, we discuss the pharmacological and structural diversity of VGSCs as revealed by studies exploring the binding properties and cross-competitive binding of site 3- or site 4-specific modulators in VGSC subtypes in synaptosomes from distinct tissues of diverse species.

Quantify work load and muscle functional activation patterns in neck-shoulder muscles of female sewing machine operators using surface electromyogram / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Work-related musculoskeletal disorders (WMSDs) have high prevalence in sewing machine operators employed in the garment industry. Long work duration, sustained low level work and precise hand work are the main risk factors of neck-shoulder disorders for sewing machine operators. Surface electromyogram (sEMG) offers a valuable tool to determine muscle activity (internal exposure) and quantify muscular load (external exposure). During sustained and/or repetitive muscle contractions, typical changes of muscle fatigue in sEMG, as an increase in amplitude or a decrease as a shift in spectrum towards lower frequencies, can be observed. In this paper, we measured and quantified the muscle load and muscular activity patterns of neck-shoulder muscles in female sewing machine operators during sustained sewing machine operating tasks using sEMG.</p><p><b>METHODS</b>A total of 18 healthy women sewing machine operators volunteered to participate in this study. Before their daily sewing machine operating task, we measured the maximal voluntary contractions (MVC) and 20%MVC of bilateral cervical erector spinae (CES) and upper trapezius (UT) respectively, then the sEMG signals of bilateral UT and CES were monitored and recorded continuously during 200 minutes of sustained sewing machine operating simultaneously which equals to 20 time windows with 10 minutes as one time window. After 200 minutes' work, we retest 20%MVC of four neck-shoulder muscles and recorded the sEMG signals. Linear analysis, including amplitude probability distribution frequency (APDF), amplitude analysis parameters such as roof mean square (RMS) and spectrum analysis parameter as median frequency (MF), were used to calculate and indicate muscle load and muscular activity of bilateral CES and UT.</p><p><b>RESULTS</b>During 200 minutes of sewing machine operating, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezius (LUT) and right upper trapezius (RUT) were 6.78%MVE, 6.94%MVE, 6.47%MVE and 5.68%MVE, respectively. Work load of right muscles are significantly higher than that of the left muscles (P < 0.05); sEMG signal analysis of isometric contractions indicated that the amplitude value before operating was significantly higher than that of after work (P < 0.01), and the spectrum value of bilateral CES and UT were significantly lower than those of after work (P < 0.01); according to the sEMG signal data of 20 time windows, with operating time pass by, the muscle activity patterns of bilateral CES and UT showed dynamic changes, the maximal amplitude of LCES, RCES, LUT occurred at the 20th time window, RUT at 16th time window, spectrum analysis showed that the lower value happened at 7th, 16th, 20th time windows.</p><p><b>CONCLUSIONS</b>Female sewing machine operators were exposed to high sustained static load on bilateral neck-shoulder muscles; left neck and shoulder muscles were held in more static positions; the 7th, 16th, and 20th time windows were muscle fatigue period that ergonomics intervention can protocol at these periods.</p>

Comparative Study on Chemical Compositions between Cuscuta Japonica and Cuscuta Chinensis Lam / 中成药

The comparative study on the chemical components of Cuscuta japonica and Cuscuta chinensis Lam have been carried out with TLC, paper chromatography and HPLC. As a result, both possessed similar chemical components and same polysaccharide compositions. But the polysaccharide recovery of Cuscuta japonica is three times as high as that of Cuscuta chinensis Lam. Both of them have 16 kinds, of amino acids. The content of 9 kinds of amino acids of Cuscuta japonica was higher than that of Cuscuta chinensis. These findings suggested that the developement and utilization of resources of Cuscuta japonica be available.