The effect of static neck flexion on mechanical and neuromuscular behaviors of the cervical spine

Occupations that involve sustained or repetitive neck flexion are associated with a higher incidence of neck pain. Little in vivo information is available on the impact of static neck flexion on cervical spinal tissue. The aim of this study was to assess changes in mechanical and neuromuscular behaviors to sustained neck flexion in healthy adults. Sixty healthy subjects aged 20–35 years participated in this study. The participants were exposed to static neck flexion at a fixed angle of full flexion for 10 min. Mechanical and neuromuscular responses of the cervical spine to sudden perturbations were measured pre- and post-exposure. Magnitude of load-relaxation during flexion exposure, stiffness, peak head angular velocity, and reflexive activities of cervical muscles were recorded. Effective neck stiffness decreased significantly, especially in female participants (P = 0.0001). The reflexive response of the cervical erector spinae muscles to head perturbation delayed significantly (P = 0.0001). Peak head angular velocity was significantly increased after exposure to neck flexion for 10 min, especially in female participants (P = 0.001). In the present study, static flexion resulted in changes in mechanical and neuromuscular behavior of the cervical spine, potentially leading to decreased stiffness of the cervical spine. The results confirm the importance of maintaining a correct head and neck position during work and improving the work environment to reduce the cervical spinal load and work-related neck pain.     

The uptake by plants of polymaleic acid: A polycarboxylic acid structurally related to those of soils

Summary The uptake of¹⁴C labelled polymaleic acid (PMA) by tomato and wheat plants cultured under axenic conditions was estimated during 48 d growth for tomato and 17 d for wheat seedlings. The concentrations of PMA, calculated from¹⁴C data, reached values of over 1 mg g⁻¹ FW for root tissue and over 0.2 mg g⁻¹ FW for shoots. Freeze-dried roots were shown to take up a substantial amount of PMA over short periods demonstrating a major non-metabolic adsorption. PMA was adsorbed by carboxymethyl cellulose, used as a model system for plant roots, in amounts comparable with freeze-dried roots. The adsorptive capacity of carboxymethyl cellulose was increased by treatment with solutions of metal ions. Especially effective in this respect were Cu, Fe and Al. It is suggested that at least two mechanisms are involved in the adsorption of PMA by polysaccharides and by plant roots. One, possibly hydrogen bonding, being independent of the presence of metal ions and another depending on the presence of multivalent cations.     

端粒酶RNA和端粒酶活性在人生殖道癌细胞株中的表达

本文采用反转录套式PCR(nested RT-PCR)和PCR端粒重复扩增(TRAP)方法分别检测了5种人生殖道癌细胞株端粒酶RNA(hTR)基因及端粒酶活性的表达。结果表明,宫颈癌HeLa和SiHa细胞株,绒毛膜癌JAR和BeWo细胞株及卵巢癌OCCI细胞株hTR及端粒酶活性均呈强阳性。但正常卵巢、宫颈和胎盘组织hTR和端粒酶呈阴性或弱阳性。提示反转录套式PCR和端粒重复扩增法可以简便而有效地检测端粒酶RNA及端粒酶活性。端粒酶的激活与肿瘤细胞增殖密切相关,并可能成为一项具有临床价值的肿瘤标志物。     

The microRNA-302-367 cluster suppresses the proliferation of cervical carcinoma cells through the novel target AKT1

The miR-302-367 cluster is specifically expressed in human embryonic stem cells and has been shown to convert human somatic cells into induced pluripotent stem cells. Here, we investigated the role of the miR-302-367 cluster in cervical carcinoma. The cluster was not endogenously expressed in cervical cancer cells, and its ectopic expression did not reprogram the cervical cancer cells to an embryonic stem cell-like state. However, ectopic expression of the miR-302-367 cluster in HeLa and SiHa cervical cancer cells inhibited cell proliferation and tumor formation by blocking the G1/S cell cycle transition. We identified a new cell cycle regulatory pathway in which the miR-302-367 cluster directly down-regulated both cyclin D1 and AKT1 and indirectly up-regulated p27^Kip1 and p21^Cip1, leading to the suppression of cervical cancer cell proliferation. Our findings suggest that the miR-302-367 cluster may be used as a therapeutic reagent for the treatment of cervical carcinoma.     

The effect of adrenomedullin on the isolated heart

A novel peptide found in human blood, adrenomedullin (ADM), has been shown to have systematic vasodepressor activity in the rat. However, the direct effects of ADM on cardiac function are unknown. Results of the present study demonstrate that ADM_13–52 possesses marked systemic vasodepressor activity in the anesthetized rat. Although ADM_13–52 modestly decreased peak systolic pressure (PSP) indicating mild negative inotropic activity, the present data suggest that bolus administration of ADM decreases systemic arterial pressure by dilating the systemic vasculature. The present data also suggest that only a portion of the ADM molecule is necessary to produce systemic vasodilation.     

Construction of artificial epithelial tissues prepared from human normal fibroblasts and C9 cervical epithelial cancer cells carrying human papillomavirus type 18 genes

One cervical cancer cell line, C9, carrying human papillomavirus type 18 (HPV18) genes that is one of the major etiologic oncoviruses for cervical cancer was characterized. This cell line was further characterized for its capacity related to the epithelial cell proliferation, stratification and differentiation in reconstituted artificial epithelial tissue. Thein vitro construction of three dimensional artificial cervical epithelial tissue has been engineered using C9 epithelial cancer cells, human foreskin fibroblasts and a matrix made of type I collagen by organotypic culture of epithelial cells. The morphology of paraffin embedded artificial tissue was examined by histochemical staining. The artificial epithelial tissues were well developed having multilayer. However, the tissue morphology was similar to the cervical tissue having displasia induced by HPV infection. The characteristics of the artificial tissues were examined by determining the expression of specific marker proteins. In the C9 derived artificial tissues, the expression of EGF receptor, an epithelial proliferation marker proteins for stratum basale was observed up to the stratum spinosum. Another epithelial proliferation marker for stratum spinosum, cytokeratins 5/6/18, were observed well over the stratum spinosum. For the differentiation markers, the expression of involucrin and filaggrin were observed while the terminal differentiation marker, cytokeratins 10/13 were not detected at all. Therefore the reconstituted artificial epithelial tissues expressed the same types of differentiation marker proteins that are expressed in normal human cervical epithelial tissues but lacked the final differentiation capacity representing characteristics of C9 cell line as a cancer tissue derived cell line. Expression of HPV18 E6 oncoprotein was also observed in this artificial cervical epithelial tissue though the intensity of the staining was weak. Thus this artificial cervical epithelial tissue though the intensity of the staining was weak. Thus this artificial epithelial tissue could be used as a useful model system to examine the relationship between HPV-induced cervical oncogenesis and epithelial cell differentiation.     

Measurement of cervical multifidus contraction pattern with ultrasound imaging

Deep muscle training has become the focus of research and exercise for patients with chronic neck pain. The objective of this in vivo study was to establish a non-invasive assessment tool for the activation of deep cervical muscles. The pattern of the change in the thickness of the cervical multifidus is described with a mathematical equation and used to compare the changes among different levels of resistance (0%, 25%, 50%, 75%, and 100%) and at different cervical levels (fourth, fifth, and sixth cervical (C4, C5, and C6) vertebrae). Twenty asymptomatic subjects (five women and 15 men; 24.3 ± 4.7 years old) were recruited for this experiment. Ultrasonography (US) with synchronized force recording was used to measure the thickness of the cervical multifidus during progressive isometric extension against resistance. Linear and quadratic models were used to estimate the patterns of change in the thickness of cervical multifidus in relation to force. Two-way analysis of variance with repeated measurement and post hoc analysis were used to investigate the differences in thickness. The change in thickness and force was better fitted by quadratic model (y = ax² + bx + c) than by the linear model. The thickness at 50% of maximum contraction was significantly increased compared with that at 25% of maximum contraction. This quantitative non-invasive measurement may provide an assessment tool for further investigation for the physiological function of the deep muscles. Further research is required to investigate whether the change of thickness was predominately determined by the recruitment of muscle fibers or the extensibility of non-contractile tissues.     

Increased content of calmodulin in morris hepatoma 5123 t.c.(h)

The content of calmodulin in the 100,000 × g supernatant and particulate fractions in Morris hepatoma 5123 t.c.(h), assayed by its ability to activate the Ca²⁺-activatable cAMP phosphodiesterase, was significantly higher (about 44%) than that in normal or host liver. Only one peak of calmodulin activity was detected when 100,000 × g supernates (350 mg protein) from sonicated homogenates of normal liver and hepatoma were fractionated on a DEAE cellulose column, eluting at a sodium acetate concentration of 0.65 M. The total calmodulin activity eluted from the hepatoma supernatant was 240% higher than that from nornal liver. The increased content of calmodulin in the hepatoma may contribute to the state of abnormal cell proliferation in this tissue.     

Manipulating cellulose biosynthesis by expression of mutant Arabidopsis proM24::CESA3ixr1‐2 gene in transgenic tobacco

Manipulation of the cellulose biosynthetic machinery in plants has the potential to provide insight into plant growth, morphogenesis and to create modified cellulose for anthropogenic use. Evidence exists that cellulose microfibril structure and its recalcitrance to enzymatic digestion can ameliorated via mis‐sense mutation in the primary cell wall–specific gene AtCELLULOSE SYNTHASE (CESA)3. This mis‐sense mutation has been identified based on conferring drug resistance to the cellulose inhibitory herbicide isoxaben. To examine whether it would be possible to introduce mutant CESA alleles via a transgenic approach, we overexpressed a modified version of CESA3, AtCESA3^ixr1‐2 derived from Arabidopsis thaliana L. Heynh into a different plant family, the Solanceae dicotyledon tobacco (Nicotiana tabacum L. variety Samsun NN). Specifically, a chimeric gene construct of CESA3^ixr1‐2, codon optimized for tobacco, was placed between the heterologous M24 promoter and the rbcSE9 gene terminator. The results demonstrated that the tobacco plants expressing M24‐CESA3^ixr1‐2 displayed isoxaben resistance, consistent with functionality of the mutated AtCESA3^ixr1‐2 in tobacco. Secondly, during enzymatic saccharification, transgenic leaf‐ and stem‐derived cellulose is 54%–66% and 40%–51% more efficient, respectively, compared to the wild type, illustrating translational potential of modified CESA loci. Moreover, the introduction of M24‐AtCESA3^ixr1‐2 caused aberrant spatial distribution of lignified secondary cell wall tissue and a reduction in the zone occupied by parenchyma cells.     

Estimation of tissue phospholipids by natural abundance 13C-NMR

The total phospholipid content of excised rat muscle, liver, brain and kidney and of human muscle biopsies was estimated by natural abundance ¹³C-NMR after complete solubilization of the tissue membranes with excess halothane. An external dioxane capillary, calibrated against pure palmitic acid and phospholipid vesicles with known phosphate concentration, was inserted into the tissues, and the repeating methylene carbon peak area in the spectra of the halothane-treated tissues was integrated versus the dioxane reference peak area. The amount of tissue used for NMR analysis was quantitated by dry weight determination after ¹³C spectroscopy was completed. The phospholipid content estimated by the indirect NMR method was in good agreement with that measured by direct phosphate analysis and with literature data. For human muscle biopsies, the NMR method can also estimate the fraction of the total phospholipids which are mobile without treating the muscles with halothane. In this respect human muscles could be separated into three different groups: (1) normal and nonspecific muscle diseases, (2) myotonia and myopathy, (3) Duchenne dystrophy; with increasing fraction of the mobile phospholipids in this order.     

A fully coupled fluid-structure interaction model of the secondary lymphatic valve

Abstract

The secondary lymphatic valve is a bi-leaflet structure frequent throughout collecting vessels that serves to prevent retrograde flow of lymph. Despite its vital function in lymph flow and apparent importance in disease development, the lymphatic valve and its associated fluid dynamics have been largely understudied. The goal of this work was to construct a physiologically relevant computational model of an idealized rat mesenteric lymphatic valve using fully coupled fluid-structure interactions to investigate the relationship between three-dimensional flow patterns and stress/deformation within the valve leaflets. The minimum valve resistance to flow, which has been shown to be an important parameter in effective lymphatic pumping, was computed as 268?g/mm⁴?s. Hysteretic behavior of the lymphatic valve was confirmed by comparing resistance values for a given transvalvular pressure drop during opening and closing. Furthermore, eddy structures were present within the sinus adjacent to the valve leaflets in what appear to be areas of vortical flow; the eddy structures were characterized by non-zero velocity values (up to ～4?mm/s) in response to an applied unsteady transvalvular pressure. These modeling capabilities present a useful platform for investigating the complex interplay between soft tissue motion and fluid dynamics of lymphatic valves and contribute to the breadth of knowledge regarding the importance of biomechanics in lymphatic system function.     

Down-Regulating Overexpressed Human Lon in Cervical Cancer Suppresses Cell Proliferation and Bioenergetics

The human mitochondrial ATP-dependent Lon protease functions in regulating the metabolism and quality control of proteins and mitochondrial DNA (mtDNA). However, the role of Lon in cancer is not well understood. Therefore, this study was undertaken to investigate the importance of Lon in cervical cancer cells from patients and in established cell lines. Microarray analysis from 30 cancer and 10 normal cervical tissues were analyzed by immunohistochemistry for Lon protein levels. The expression of Lon was also examined by immunoblotting 16 fresh cervical cancer tissues and their respective non-tumor cervical tissues. In all cases, Lon expression was significantly elevated in cervical carcinomas as compared to normal tissues. Augmented Lon expression in tissue microarrays did not vary between age, tumor-node-metastasis grades, or lymph node metastasis. Knocking down Lon in HeLa cervical cancer cells by lentivrial transduction resulted in a substantial decrease in both mRNA and protein levels. Such down-regulation of Lon expression significantly blocked HeLa cell proliferation. In addition, knocking down Lon resulted in decreased cellular bioenergetics as determined by measuring aerobic respiration and glycolysis using the Seahorse XF24 extracellular flux analyzer. Together, these data demonstrate that Lon plays a potential role in the oncogenesis of cervical cancer, and may be a useful biomarker and target in the treatment of cervical cancer. Lon; immunohistochemistry; cervical cancer; cell proliferation; cellular bioenergetics.     

An EMG-driven biomechanical model of the canine cervical spine

Due to the frequency of cervical spine injuries in canines, the purpose of this effort was to develop an EMG-driven dynamic model of the canine cervical spine to assess a biomechanical understanding that enables one to investigate the risk of neck disorders. A canine subject was recruited in this investigation in order to collect subject specific data. Reflective markers and a motion capture system were used for kinematic measurement; surface electrodes were used to record electromyography signals, and with the aid of force plate kinetics were recorded. A 3D model of the canine subject was reconstructed from an MRI dataset. Muscles lines of action were defined through a new technique with the aid of 3D white light scanner. The model performed well with a 0.73 weighted R² value in all three planes. The weighted average absolute error of the predicted moment was less than 10% of the external moment. The proposed model is a canine specific forward-dynamics model that precisely tracks the canine subject head and neck motion, calculates the muscle force generated from the twelve major moment producing muscles, and estimates resulting loads on specific spinal tissues.     

Regulation of the intracellular calcium level in human blood platelets: Cyclic adenosine 3′,5′-monophosphate dependent phosphorylation of a 22 000 dalton component in isolated Ca-accumulating vesicles

Two protein kinase activities have been separated from the supernatants of homogenized human blood platelets by DEAE cellulose chromatography. One of them (peak I enzyme) is an efficient stimulator of the uptake of Ca²⁺ into isolated membrane vesicles in the presence of cyclic AMP and ATP. The second (peak II enzyme), although equally active towards histone, exerts only about one third of the activity of the peak I enzyme. The stimulation of Ca²⁺ uptake is accompanied by the phosphorylation of a membrane protein with an apparent molecular weight of 22 000, which appears to play an essential role in the regulation of the intracellular Ca²⁺ level and hence of platelet activity.     

Regulation of the intracellular calcium level in human blood platelets: Cyclic adenosine 3′,5′-monophosphate dependent phosphorylation of a 22 000 dalton component in isolated Ca2+-accumulating vesicles

Two protein kinase activities have been separated from the supernatants of homogenized human blood platelets by DEAE cellulose chromatography. One of them (peak I enzyme) is an efficient stimulator of the uptake of Ca²⁺ into isolated membrane vesicles in the presence of cyclic AMP and ATP. The second (peak II enzyme), although equally active towards histone, exerts only about one third of the activity of the peak I enzyme. The stimulation of Ca²⁺ uptake is accompanied by the phosphorylation of a membrane protein with an apparent molecular weight of 22 000, which appears to play an essential role in the regulation of the intracellular Ca²⁺ level and hence of platelet activity.     

The Expression of CD90/Thy-1 in Hepatocellular Carcinoma: An In Vivo and In Vitro Study

Although the CD90 (Thy-1) was proposed as biomarker of several tumors and cancer stem cells, the involvement of this molecule in the progression of hepatocellular carcinoma (HCC) and other less frequent hepatic neoplasms is still undefined. The distribution of CD90 was investigated both in in vivo (human tissues samples) and in vitro (human HCC cell line JHH-6). A total of 67 liver tumors were analyzed: 51 HCC, 6 cholangiocarcinoma and 10 hepatoblastoma. In all cases, paired tissue sample of both the tumor and cirrhotic liver was available. Hepatic tissue obtained in 12 healthy livers was used as control. CD90 gene expression was studied by RT-qPCR, protein expression was assessed by quantitative Western Blot, immunofluorescence and flow cytometry. The CD90 expression analysis showed a significant increment in tumor compared to both its paired cirrhotic tissue and normal liver (p<0.05 and p<0.001, respectively). This increase was accompanied by the up-regulation of stromal component in the cancer, as demonstrated by alpha smooth muscle actin staining. In vitro analysis of JHH-6 cell line showed a higher proliferation capacity of CD90⁺ compared to CD90^- cells (p<0.001), also noticed in 3D clonogenic assay (p<0.05), associated by a significant higher expression of the promoting factors (hepatocyte growth factor, fibroblast associated protein and alpha smooth muscle actin 2). A higher expression of the breast cancer resistance protein was found in CD90⁺ subpopulation while the multidrug resistance protein 1 showed an opposite behavior. Collectively, these results point to the importance of CD90 in the HCC.     

Tim-3 Expression in Cervical Cancer Promotes Tumor Metastasis

BackgroundT cell immunoglobulin mucin-3 (Tim-3) has been identified as a negative regulator of anti-tumor immunity. Recent studies highlight the important role of Tim-3 in the CD8⁺ T cell exhaustion that takes place in both human and animal cancer models. However, the nature of Tim-3 expression in the tumor cell and the mechanism by which it inhibits anti-tumor immunity are unclear. This present study aims to determine Tim-3 is expressed in cervical cancer cells and to evaluate the role of Tim-3 in cervical cancer progression.MethodologyA total of 85 cervical tissue specimens including 43 human cervical cancer, 22 cervical intraepithelial neoplasia (CIN) and 20 chronic cervicitis were involved. Tim-3 expression in tumor cells was detected and was found to correlate with clinicopathological parameters. Meanwhile, expression of Tim-3 was assessed by RT-PCR, Western Blot and confocal microscopy in cervical cancer cell lines, HeLa and SiHa. The migration and invasion potential of Hela cells was evaluated after inhibiting Tim-3 expression by ADV-antisense Tim-3.ConclusionsWe found that Tim-3 was expressed at a higher level in the clinical cervical cancer cells compared to the CIN and chronic cervicitis controls. We supported this finding by confirming the presence of Tim-3 mRNA and protein in the cervical cell lines. Tim-3 expression in tumor cells correlated with clinicopathological parameters. Patients with high expression of Tim-3 had a significant metastatic potential, advanced cancer grades and shorter overall survival than those with lower expression. Multivariate analysis showed that Tim-3 expression was an independent factor for predicting the prognosis of cervical cancer. Significantly, down-regulating the expression of Tim-3 protein inhibited migration and invasion of Hela cells. Our study suggests that the expression of Tim-3 in tumor cells may be an independent prognostic factor for patients with cervical cancer. Moreover, Tim-3 expression may promote metastatic potential in cervical cancers.     

Oxygen Isotope Exchange between Metabolites and Water during Biochemical Reactions Leading to Cellulose Synthesis

Cellulose was produced heterotrophically from different carbon substrates by carrot tissue cultures and Acetobacter xylinum (a cellulose-producing bacterium) and by castor bean seeds germinated in the dark, in each case in the presence of water having known concentration of oxygen-18 (¹⁸O). We used the relationship between the amount of ¹⁸O in the water and in the cellulose that was synthesized to determine the number and ¹⁸O content of the substrate oxygens that exchanged with water during the reactions leading to cellulose synthesis. Our observations support the hypothesis that oxygen isotope ratios of plant cellulose are determined by isotopic exchange occurring during hydration of carbonyl groups of the intermediates of cellulose synthesis.