Nanoparticles with tunable pharmacokinetics are desirable for various biomedical applications. Poly(ethylene glycol) (PEG) is well known to create “stealth” effects to stabilize and extend the blood circulation of nanoparticles. In this work, poly(carboxybetaine) (PCB), a new non-fouling polymer material, was incorporated as surface-grafted coatings, conjugated onto degradable shell crosslinked knedel-like nanoparticles (dSCKs) composed of poly(acrylic acid)- based shells and poly(lactic acid) (PLA) cores, to compare the in vivo pharmacokinetics to their PEG-functionalized analogs. A series of five dSCKs was prepared from amphiphilic block copolymers, having different numbers and lengths of either PEG or PCB grafts, by supramolecular assembly in water followed by shell crosslinking, and then studied by a lactate assay to confirm their core hydrolytic degradabilities. Each dSCK was also conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) macrocyclic chelators and tyramine moieties to provide for 64Cu and/or radiohalogen labeling. The high specific activity of 64Cu radiolabeling ensured nanogram administration of dSCKs for in vivo evaluation of their pharmacokinetics. Biodistribution studies demonstrated comparable in vivo pharmacokinetic profiles of PCB-grafted dSCKs to their PEG-conjugated counterparts. These results indicated that PCB-functionalized dSCKs have great potential as a theranostic platform for translational research.
Pharmacokinetic; biodistribution; radiolabeling; poly(carboxybetaine); poly(ethylene glycol); nanomedicine; shell crosslinked knedel-like nanoparticles
A series of functionalized aza-polycyclic aromatic compounds were prepared by a superacid-promoted ring closing and opening reaction cascade. A reaction mechanism is proposed, which involves reactive dicationic intermediates. A key step in the conversions involves ipso protonation of an aryl group and elimination of an alkyl phenyl group.
Heterocycle; Superacid; Dication; Aza-polycyclic aromatic compounds; Condensation
To grow precisely aligned graphene on h-BN without metal catalyst is extremely important, which allows for intriguing physical properties and devices of graphene/h-BN hetero-structure to be studied in a controllable manner. In this report, such hetero-structures were fabricated and investigated by atomic resolution scanning probe microscopy. Moiré patterns are observed and the sensitivity of moiré interferometry proves that the graphene grains can align precisely with the underlying h-BN lattice within an error of less than 0.05°. The occurrence of moiré pattern clearly indicates that the graphene locks into h-BN via van der Waals epitaxy with its interfacial stress greatly released. It is worthy to note that the edges of the graphene grains are primarily oriented along the armchair direction. The field effect mobility in such graphene flakes exceeds 20,000 cm2·V−1·s−1 at ambient condition. This work opens the door of atomic engineering of graphene on h-BN, and sheds light on fundamental research as well as electronic applications based on graphene/h-BN hetero-structure.
Recognition of sweet, bitter and umami tastes requires the non-vesicular release from taste bud cells of adenosine 5′-triphosphate (ATP), which acts as a neurotransmitter to activate afferent neural gustatory pathways1. However, how ATP is released to fulfill this function is not fully understood. Here we show that calcium homeostasis modulator 1 (CALHM1), a voltage-gated ion channel2,3, is indispensable for taste stimuli-evoked ATP release from sweet-, bitter- and umami-sensing taste bud cells. Calhm1 knockout mice have severely impaired perceptions of sweet, bitter and umami compounds, whereas sour and salty taste recognition remains mostly normal. Calhm1 deficiency affects taste perception without interfering with taste cell development or integrity. CALHM1 is expressed specifically in sweet/bitter/umami-sensing type II taste bud cells. Its heterologous expression induces a novel ATP permeability that releases ATP from cells in response to manipulations that activate the CALHM1 ion channel. Knockout of Calhm1 strongly reduces voltage-gated currents in type II cells and taste-evoked ATP release from taste buds without affecting the excitability of taste cells to taste stimuli. Thus, CALHM1 is a voltage-gated ATP release channel required for sweet, bitter and umami taste perception.
The aims of this study were (1) to document the recognition performance of environmental sounds (ESs) in Mandarin-speaking children with cochlear implants (CIs) and to analyze the possible associated factors with the ESs recognition; (2) to examine the relationship between perception of ESs and receptive vocabulary level; and (3) to explore the acoustic factors relevant to perceptual outcomes of daily ESs in pediatric CI users. Forty-seven prelingually deafened children between ages 4 to 10 years participated in this study. They were divided into pre-school (group A: age 4–6) and school-age (group B: age 7 to 10) groups. Sound Effects Recognition Test (SERT) and the Chinese version of the revised Peabody Picture Vocabulary Test (PPVT-R) were used to assess the auditory perception ability. The average correct percentage of SERT was 61.2% in the preschool group and 72.3% in the older group. There was no significant difference between the two groups. The ESs recognition performance of children with CIs was poorer than that of their hearing peers (90% in average). No correlation existed between ESs recognition and receptive vocabulary comprehension. Two predictive factors: pre-implantation residual hearing and duration of CI usage were found to be associated with recognition performance of daily-encountered ESs. Acoustically, sounds with distinct temporal patterning were easier to identify for children with CIs. In conclusion, we have demonstrated that ESs recognition is not easy for children with CIs and a low correlation existed between linguistic sounds and ESs recognition in these subjects. Recognition ability of ESs in children with CIs can only be achieved by natural exposure to daily-encountered auditory stimuli if sounds other than speech stimuli were less emphasized in routine verbal/oral habilitation program. Therefore, task-specific measures other than speech materials can be helpful to capture the full profile of auditory perceptual progress after implantation.
Previous Vagus Nerve Stimulation (VNS) studies have demonstrated anti-nociceptive effects, and recent non-invasive approaches; termed transcutaneous-VNS, or t-VNS, have utilized stimulation of the auricular branch of the vagus nerve in the ear. The dorsal medullary vagal system operates in tune with respiration, and we propose that supplying vagal afferent stimulation gated to the exhalation phase of respiration can optimize t-VNS.
counterbalanced, crossover study.
patients with chronic pelvic pain (CPP) due to endometriosis in a specialty pain clinic.
We evaluated evoked pain analgesia for Respiratory-gated Auricular Vagal Afferent Nerve Stimulation (RAVANS) compared with Non-Vagal Auricular Stimulation (NVAS). RAVANS and NVAS were evaluated in separate sessions spaced at least one week apart. Outcome measures included deep tissue pain intensity, temporal summation of pain, and anxiety ratings, which were assessed at baseline, during active stimulation, immediately following stimulation, and 15 minutes after stimulus cessation.
RAVANS demonstrated a trend for reduced evoked pain intensity and temporal summation of mechanical pain, and significantly reduced anxiety in N=15 CPP patients, compared to NVAS, with moderate to large effect sizes (eta2>0.2).
Chronic pain disorders such as CPP are in great need of effective, non-pharmacological options for treatment. RAVANS produced promising anti-nociceptive effects for QST outcomes reflective of the noted hyperalgesia and central sensitization in this patient population. Future studies should evaluate longer-term application of RAVANS to examine its effects on both QST outcomes and clinical pain.
Malaria is one of the most widespread and deadly human parasitic diseases caused by the Plasmodium (P.) species with the P.falciparum being the most deadly. The parasites are capable of invading red blood cells (RBCs) during infection. At the late stage of parasites’ development, the parasites export proteins to the infected RBCs (iRBC) membrane and bind to receptors of surface proteins on the endothelial cells that line microvasculature walls. Resulting adhesion of iRBCs to microvasculature is one of the main sources of most complications during malaria infection. Therefore, it is important to develop a versatile and simple experimental method to quantitatively investigate iRBCs cytoadhesion and binding kinetics. Here, we developed an advanced flow based adhesion assay to demonstrate that iRBC’s adhesion to endothelial CD36 receptor protein coated channels is a bistable process possessing a hysteresis loop. This finding confirms a recently developed model of cell adhesion which we used to fit our experimental data. We measured the contact area of iRBC under shear flow at different stages of infection using Total Internal Reflection Fluorescence (TIRF), and also adhesion receptor and ligand binding kinetics using Atomic Force Microscopy (AFM). With these parameters, we reproduced in our model the experimentally observed changes in adhesion properties of iRBCs accompanying parasite maturation and investigated the main mechanisms responsible for these changes, which are the contact area during the shear flow as well as the rupture area size.
N-WASP is critical for cancer cell invasion through its promotion of the trafficking and capture of MT1-MMP in invasive pseudopods.
Metastasizing tumor cells use matrix metalloproteases, such as the transmembrane collagenase MT1-MMP, together with actin-based protrusions, to break through extracellular matrix barriers and migrate in dense matrix. Here we show that the actin nucleation–promoting protein N-WASP (Neural Wiskott-Aldrich syndrome protein) is up-regulated in breast cancer, and has a pivotal role in mediating the assembly of elongated pseudopodia that are instrumental in matrix degradation. Although a role for N-WASP in invadopodia was known, we now show how N-WASP regulates invasive protrusion in 3D matrices. In actively invading cells, N-WASP promoted trafficking of MT1-MMP into invasive pseudopodia, primarily from late endosomes, from which it was delivered to the plasma membrane. Upon MT1-MMP’s arrival at the plasma membrane in pseudopodia, N-WASP stabilized MT1-MMP via direct tethering of its cytoplasmic tail to F-actin. Thus, N-WASP is crucial for extension of invasive pseudopods into which MT1-MMP traffics and for providing the correct cytoskeletal framework to couple matrix remodeling with protrusive invasion.
Plasmodium falciparum infection of human erythrocytes is known to result in the modification of the host cell cytoskeleton by parasite-coded proteins. However, such modifications and corresponding implications in malaria pathogenesis have not been fully explored. Here, we probed the gradual modification of infected erythrocyte cytoskeleton with advancing stages of infection using atomic force microscopy (AFM). We reported a novel strategy to derive accurate and quantitative information on the knob structures and their connections with the spectrin network by performing AFM–based imaging analysis of the cytoplasmic surface of infected erythrocytes. Significant changes on the red cell cytoskeleton were observed from the expansion of spectrin network mesh size, extension of spectrin tetramers and the decrease of spectrin abundance with advancing stages of infection. The spectrin network appeared to aggregate around knobs but also appeared sparser at non-knob areas as the parasite matured. This dramatic modification of the erythrocyte skeleton during the advancing stage of malaria infection could contribute to the loss of deformability of the infected erythrocyte.
The mythological story of the Golden Fleece symbolizes the magical regenerative power of skin appendages. Similar to the adventurous pursuit of the Golden Fleece by the multi-talented Argonauts, today we also need an integrated multi-disciplined approach to understand the cellular and molecular processes during development, regeneration and evolution of skin appendages. To this end, we have explored several aspects of skin appendage biology that contribute to the Turing activator / inhibitor model in feather pattern formation, the topo-biological arrangement of stem cells in organ shape determination, the macro-environmental regulation of stem cells in regenerative hair waves, and potential novel molecular pathways in the morphological evolution of feathers. Here we show our current integrative biology efforts to unravel the complex cellular behavior in patterning stem cells and the control of regional specificity in skin appendages. We use feather / scale tissue recombination to demonstrate the timing control of competence and inducibility. Feathers from different body regions are used to study skin regional specificity. Bioinformatic analyses of transcriptome microarrays show the potential involvement of candidate molecular pathways. We further show Hox genes exhibit some region specific expression patterns. To visualize real time events, we applied time-lapse movies, confocal microscopy and multiphoton microscopy to analyze the morphogenesis of cultured embryonic chicken skin explants. These modern imaging technologies reveal unexpectedly complex cellular flow and organization of extracellular matrix molecules in three dimensions. While these approaches are in preliminary stages, this perspective highlights the challenges we face and new integrative tools we will use. Future work will follow these leads to develop a systems biology view and understanding in the morphogenetic principles that govern the development and regeneration of ectodermal organs.
feathers; hairs; systems biology; stem cells; regeneration; microarray analyses; imaging; multiphoton microscopy; regional specificity
Pseudomonas stutzeri T13 is a highly efficient aerobic denitrifying bacterium. Information about the genome of this aerobic denitrifying bacterium has been limited until now. We present the draft genome of P. stutzeri T13. The results could provide further insight into the aerobic denitrification mechanism in strain T13.
Pseudomonas psychrophila HA-4 is a cold-adaptable, sulfamethoxazole-degrading bacterium. The genes related to its cold adaptation mechanism and sulfamethoxazole metabolism were unknown. We present the draft genome of strain HA-4. It could provide further insight into the sulfamethoxazole-degrading mechanism of strain HA-4.
Lowering intraocular pressure (IOP) is currently the only strategy documented to slow the onset and progression of glaucomatous blindness. Ouabain, a cardiotonic glycoside inhibitor of Na+, K+-activated ATPase, was recently reported to enhance outflow facility in porcine anterior segments at concentrations as low as 30 nM for ≥ 4 hrs, suggesting a novel approach to lowering IOP. The underlying mechanism is unknown, but associated cytoskeletal changes were observed in porcine trabecular meshwork cells. We have previously found that changes in ATP release and subsequent ectoenzymatic conversion to adenosine may play a role in linking cytoskeletal remodeling with modulation of outflow resistance. We now tested whether altered ATP release might also be a mediator of ouabain’s effect on outflow facility. ATP release from transformed human TM5 and explant-derived human trabecular meshwork cells was measured by the luciferin-luciferase reaction. Matrix metalloproteinases (MMPs) were studied by zymography, cell Na+concentration by SBFI fluorometry, gene expression of ATP-release pathways by real-time PCR, cell volume by electronic cell sorting and cell viability by the LDH and MTT methods. Actin was examined by confocal microscopy of phalloidin-stained cells. Contrary to expectation, ouabain at concentrations ≥ 10 nM inhibited swelling-triggered ATP release from TM5 cells after ≥ 4 hrs of exposure. Inhibition was enhanced by increasing ouabain concentration and exposure time. Similar effects were produced by the reversible cardiac aglycone strophanthidin. Ouabain also inhibited swelling-activated ATP release from explant-derived native human TM cells. Ouabain (4 hrs, 30 nM and 100 nM) did not alter gene expression of the ATP-release pathways, and cell viability was unchanged by exposure to ouabain (30 nM to 1 μM). Preincubation with 30 nM ouabain for 4 hrs did not detectably change Na+ level, the regulatory volume decrease (RVD) or the actin cytoskeleton of TM5 cells, but did inhibit hypotonicity-elicited ATP release. Moreover, even when N-methyl-D-glucose replaced Na+in the extracellular fluid, ouabain still inhibited swelling-initiated ATP release at 100 nM. In the absence of ouabain, extracellular ATP stimulated MMP secretion, which was largely blocked by inhibiting conversion of ATP to adenosine, as expected. In contrast, ouabain reduced ATP release, but did not alter secretion of MMP-2 and MMP-9 from cells pretreated for ≤4 hrs. The results suggest that: (1) ouabain can trigger enhancement of outflow facility independent of its transport and actin-restructuring effects exerted at higher concentration and longer duration; (2) ouabain exerts parallel independent effects on ATP release and outflow facility; and (3) these effects likely reflect ouabain-induced changes in the scaffolding and/or signaling functions of Na+, K+-activated ATPase.
ATP release; adenosine; matrix metalloproteinase; Na+, K+-activated ATPase; cytoskeleton
Harnessing community intelligence in knowledge curation bears significant promise in dealing with communication and education in the flood of scientific knowledge. As knowledge is accumulated at ever-faster rates, scientific nomenclature, a particular kind of knowledge, is concurrently generated in all kinds of fields. Since nomenclature is a system of terms used to name things in a particular discipline, accurate translation of scientific nomenclature in different languages is of critical importance, not only for communications and collaborations with English-speaking people, but also for knowledge dissemination among people in the non-English-speaking world, particularly young students and researchers. However, it lacks of accuracy and standardization when translating scientific nomenclature from English to other languages, especially for those languages that do not belong to the same language family as English. To address this issue, here we propose for the first time the application of community intelligence in scientific nomenclature management, namely, harnessing collective intelligence for translation of scientific nomenclature from English to other languages. As community intelligence applied to knowledge curation is primarily aided by wiki and Chinese is the native language for about one-fifth of the world’s population, we put the proposed application into practice, by developing a wiki-based English-to-Chinese Scientific Nomenclature Dictionary (ESND; http://esnd.big.ac.cn). ESND is a wiki-based, publicly editable and open-content platform, exploiting the whole power of the scientific community in collectively and collaboratively managing scientific nomenclature. Based on community curation, ESND is capable of achieving accurate, standard, and comprehensive scientific nomenclature, demonstrating a valuable application of community intelligence in knowledge curation.
“Click” chemistry is a library of efficient and reliable reactions, which have been used to functionalize various classes of bio- and synthetic macromolecular systems for the incorporation of designed properties and functions. In this report, azide-alkyne Huisgen cycloaddition and thiol-yne reactions, two classical “click” chemistries, were employed to functionalize biodegradable, clickable polyphosphoester homopolymers and their water-soluble copolymers. A stable alkyne-functionalized phospholane monomer was synthesized, its organocatalyzed polymerization kinetics were evaluated, and the resulting (co)polymers were utilized to develop this facile method that provides the synthesis of clickable, water-soluble and degradable polyphosphoesters, which can be adapted for various applications.
Laparoscopic partial gastrectomy without lymph node dissection has been accepted worldwide for the treatment of small gastric gastrointestinal stromal tumors (GISTs). However, the role of laparoscopic surgery in the treatment of large gastric GISTs remains under debate due to the risk of tumor spillage or rupture of the tumor capsule leading to peritoneal seeding. To the best of our knowledge, one-stage laparoscopic resection for a large gastric GIST and synchronous liver metastases following preoperative imatinib therapy has not been previously reported. Here, we present our initial experience of this method of treatment.
gastrointestinal stromal tumor; laparoscopic; imatinib; preoperative therapy
Although the treatment technology of sulfamethoxazole has been investigated widely, there are various issues such as the high cost, inefficiency, and secondary pollution which restricted its application. Bioflocculant, as a novel method, is proposed to improve the removal efficiency of PPCPs, which has an advantage over other methods. Bioflocculant MFX, composed by high polymer polysaccharide and protein, is the metabolism product generated and secreted by Klebsiella sp. In this paper, MFX is added to 1 mg/L sulfanilamide aqueous solution substrate, and the removal ratio is evaluated. According to literatures review, for MFX absorption of sulfanilamide, flocculant dosage, coagulant-aid dosage, pH, reaction time, and temperature are considered as influence parameters. The result shows that the optimum condition is 5 mg/L bioflocculant MFX, 0.5 mg/L coagulant aid, initial pH 5, and 1 h reaction time, and the removal efficiency could reach 67.82%. In this condition, MFX could remove 53.27% sulfamethoxazole in domestic wastewater, and the process obeys Freundlich equation. R2 value equals 0.9641. It is inferred that hydrophobic partitioning is an important factor in determining the adsorption capacity of MFX for sulfamethoxazole solutes in water; meanwhile, some chemical reaction probably occurs.
MicroRNA alterations are likely to contribute to the development of pancreatic cancer and may serve as markers for the early detection of pancreatic neoplasia.
To identify the microRNA alterations that arise during the development of pancreatic cancer we determined the levels of 735 miRNAs in 34 pancreatic intraepithelial neoplasias (PanINs) and 15 normal pancreatic duct samples isolated by laser capture microdissection using TaqMan miRNA microarrays. Differential expression of selected miRNAs was confirmed by fluorescent in-situ hybridization analysis and by qRT-PCR analysis of selected candidate microRNAs in an independent set of PanIN and normal duct samples.
We identified 107 aberrantly expressed miRNAs in different PanIN grades compared with normal pancreatic duct samples, and 35 aberrantly expressed miRNAs in PanIN-3 lesions compared with normal pancreatic duct samples. These differentially expressed miRNAs included those that have been previously identified as differentially expressed in pancreatic ductal adenocarcinomas (including miR-21, miR-200a/b/c, miR-216a/b, miR-217, miR-146a, miR-155, miR-182, miR-196b, miR-203, miR-222, miR-338-3p, miR-486-3p and others) as well as miRNAs not previously described as differentially expressed in these lesions (miR-125b, miR-296-5p, miR-183*, miR-603, miR-625/*, miR-708 and others). MiR-196b was the most selectively differentially expressed miRNA in Panin-3 lesions.
Many miRNAs undergo aberrant expression in PanIN lesions and are likely to be important in the development of pancreatic ductal adenocarcinoma. MicroRNAs such as miR-196b whose expression is limited to PanIN-3 lesions or pancreatic cancers could be useful as diagnostic markers.
The Second China National Sample Survey on Disability in 2006 showed that the participation rate of disabled Chinese rural individuals in social medical insurance participation was less than 30%. However, there has been limited number of studies on the influencing factors, especially contextual factors, affecting their participation in social medical insurance. Therefore, this study aimed to analyze the factors influencing the participation of disabled rural individuals in social medical insurance, including contextual factors.
Based on data derived from the Second China National Sample Survey on Disability, chi-square test and two-level logistic regression model were used to analyze the influencing factors.
The results showed that the disabled rural individuals in the New Rural Cooperative Medical System pilot counties who lived in communities with rehabilitation stations or with higher per capita income of villagers were more likely to participate in the social medical insurance. Meanwhile, those employed, with less severe disability degree or with less severe barriers in participation in society were more likely to participate in the social medical insurance.
Contextual factors including economic and policy contexts were important factors influencing their participation in social medical insurance before 2006 in China. Unemployment, severer disability degree and social isolation might also prevent them from gaining equal access to social medical insurance.
Multilevel modeling; Influencing factor; Rural disabled persons; Social medical insurance
Intraductal papillary mucinous neoplasms (IPMNs) are precursors to infiltrating pancreatic ductal adenocarcinomas. Widespread epigenetic alterations are characteristic of many cancers, yet few studies have systematically analyzed epigenetic alterations of neoplastic precursors. Our goal was to perform genome-wide CpG island methylation profiling to identify aberrantly methylated loci in IPMNs.
We compared the CpG island methylation profiles of 6 IPMNs to normal primary pancreatic duct samples using methylation CpG island amplification (MCA) and Agilent CpG island microarray (MCAM) analysis. When selected 13 genes identified as differentially methylated by MCAM for methylation-specific PCR (MSP) analysis in an independent set of IPMNs and normal pancreas samples and performed expression analysis of selected genes.
We identified 2,259 loci as differentially methylated in at least one of 6 IPMNs including 245 genes hypermethylated in IPMNs with high-grade dysplasia compared to normal pancreatic duct samples. Eleven of 13 genes evaluated by MSP were more commonly methylated in 61 IPMNs than in 43 normal pancreas samples. Several genes, (BNIP3, PTCHD2, SOX17, NXPH1, EBF3), were significantly more likely to be methylated in IPMNs with high-grade than with lower-grade dysplasia. One gene, Sox17, demonstrated loss of protein expression by immunohistochemistry in 22% (19 of 88) of IPMNs. The most specific marker, BNIP3, was not methylated in any IPMNs with low-grade dysplasia or in normal pancreas samples.
IPMNs undergo extensive aberrant CpG island hypermethylation. The detection of genes selectively methylated in high-grade IPMNs such as BNIP3 may have utility in the clinical evaluation of IPMNs.
Intraductal papillary mucinous neoplasm; Pancreas; pancreatic cancer; DNA Methylation; CpG Island
Our guiding hypothesis is that ecto-enzymatic conversion of extracellular ATP to adenosine activates A1 adenosine receptors, reducing resistance to aqueous humor outflow and intraocular pressure. The initial step in this purinergic regulation is ATP release from outflow-pathway cells by mechanisms unknown. We measured similar ATP release from human explant-derived primary trabecular meshwork (TM) cells (HTM) and a human TM cell line (TM5). Responses to 21 inhibitors indicated that pannexin-1 (PX1) and connexin (Cx) hemichannels and P2X7 receptors (P2RX7) were comparably important in modulating ATP release induced by hypotonic swelling, whereas vesicular release was insignificant. Consistent with prior studies of PX1 activity in certain other cells, ATP release was lowered by the reducing agent dithiothreitol. Overexpressing PX1 in HEK293T cells promoted, while partial knockdown (KD) in both HEK293T and TM5 cells inhibited hypotonicity-activated ATP release. Additionally, KD reduced the pharmacologically-defined contribution of PX1 and enhanced those of Cx and P2RX7. ATP release was also triggered by raising intracellular Ca2+ activity with ionomycin after a prolonged lag time and was unaffected by the PX1 blocker probenecid, but nearly abolished by P2RX7 antagonists. We conclude that swelling-stimulated ATP release from human TM cells is physiologically mediated by PX1 and Cx hemichannels and P2X7 receptors, but not by vesicular release. PX1 appears not to be stimulated by intracellular Ca2+ in TM cells, but can be modulated by oxidation-reduction state. The P2RX7-dependent component of swelling-activated release may be mediated by PX1 hemichannels or reflect apoptotic magnification of ATP release, either through itself and/or hemichannels.
Pannexin-1; Connexins; Hemichannels; P2X7 ATP receptors; Aqueous humor outflow
From September 2008 to December 2010, 112 Haemophilus parasuis strains were isolated from 536 pigs with clinical signs of Glässer’s disease in South China, for a frequency of 21%. The 112 strains were subjected to serovar analysis by gel diffusion (GD) and indirect hemagglutination (IHA) tests and to genotype analysis by means of pulsed-field gel electrophoresis (PFGE). With a combination of the GD and IHA results, serovars 5 and 4 were found to be the most prevalent, at 23% and 17%, respectively, followed by serovars 2 (8%), 15 (7%), 13 (6%), and 12 (5%); 20% of the strains were nontypeable. The 112 strains were genetically diverse, with 85 genotypes identified (discriminatory index 0.992). The 89 typeable isolates belonged to 15 H. parasuis serovars displaying 63 different PFGE profiles. The 23 nontypeable strains displayed 22 different PFGE profiles. These findings confirmed that 15 serovars and diverse genotypes of H. parasuis were widely distributed in southern China.
Annoying snore is the principle symptom and problem in obstructive sleep apnea syndrome (OSAS). However, investigation has been hampered by the complex snoring sound analyses.
This study was aimed to investigate the energy types of the full-night snoring sounds in patients with OSAS.
Patients and Method
Twenty male OSAS patients underwent snoring sound recording throughout 6 hours of in-lab overnight polysomnogragphy. Snoring sounds were processed and analyzed by a new sound analytic program, named as Snore Map®. We transformed the 6-hour snoring sound power spectra into the energy spectrum and classified it as snore map type 1 (monosyllabic low-frequency snore), type 2 (duplex low-&mid-frequency snore), type 3 (duplex low- & high-frequency snore), and type 4 (triplex low-, mid-, & high-frequency snore). The interrator and test-retest reliabilities of snore map typing were assessed. The snore map types and their associations among demographic data, subjective snoring questionnaires, and polysomnographic parameters were explored.
The interrator reliability of snore map typing were almost perfect (κ = 0.87) and the test-retest reliability was high (r = 0.71). The snore map type was proportional to the body mass index (r = 0.63, P = 0.003) and neck circumference (r = 0.52, P = 0.018). Snore map types were unrelated to subjective snoring questionnaire scores (All P>0.05). After adjustment for body mass index and neck circumference, snore map type 3–4 was significantly associated with severity of OSAS (r = 0.52, P = 0.026).
Snore map typing of a full-night energy spectrum is feasible and reliable. The presence of a higher snore map type is a warning sign of severe OSAS and indicated priority OSAS management. Future studies are warranted to evaluate whether snore map type can be used to discriminate OSAS from primary snoring and whether it is affected by OSAS management.
MicroRNAs (miRNAs) play important roles in the regulation of rodent tooth development, but little is known about their role in tooth development in large mammals. We identified 637 unique miRNA sequences in a large-scale screen for miRNA expression profiles in the developing lower deciduous molars of miniature pigs (Sus scrofa) using Illumina Solexa deep sequencing. These candidate miRNAs and another 105 known Sus scrofa miRNAs were included in the custom-designed microarray and used to analyze the miRNA expression profile in the bud, cap, early bell, and late bell stages of tooth development. Microarray analysis revealed 166 transcripts that were differentially expressed in the four stages. Bioinformatic analysis identified 18 key miRNAs, including let-7f, miR-128, miR-200b, and miR-200c, that might play key roles in tooth development. Taken together, our results not only identified the specific microRNAome and expression profile in developing lower deciduous molars of the miniature pig, but they also provided useful information for investigating the molecular mechanism of tooth development in the miniature pig.
Lineage specific differentiation of human embryonic stem cells (hESCs) is largely mediated by specific growth factors and extracellular matrix molecules. Growth factors initiate a cascade of signals which control gene transcription and cell fate specification. There is a lot of interest in inducing hESCs to an endoderm fate which serves as a pathway towards more functional cell types like the pancreatic cells. Research over the past decade has established several robust pathways for deriving endoderm from hESCs, with the capability of further maturation. However, in our experience, the functional maturity of these endoderm derivatives, specifically to pancreatic lineage, largely depends on specific pathway of endoderm induction. Hence it will be of interest to understand the underlying mechanism mediating such induction and how it is translated to further maturation. In this work we analyze the regulatory interactions mediating different pathways of endoderm induction by identifying co-regulated transcription factors.
hESCs were induced towards endoderm using activin A and 4 different growth factors (FGF2 (F), BMP4 (B), PI3KI (P), and WNT3A (W)) and their combinations thereof, resulting in 15 total experimental conditions. At the end of differentiation each condition was analyzed by qRT-PCR for 12 relevant endoderm related transcription factors (TFs). As a first approach, we used hierarchical clustering to identify which growth factor combinations favor up-regulation of different genes. In the next step we identified sets of co-regulated transcription factors using a biclustering algorithm. The high variability of experimental data was addressed by integrating the biclustering formulation with bootstrap re-sampling to identify robust networks of co-regulated transcription factors. Our results show that the transition from early to late endoderm is favored by FGF2 as well as WNT3A treatments under high activin. However, induction of late endoderm markers is relatively favored by WNT3A under high activin.
Use of FGF2, WNT3A or PI3K inhibition with high activin A may serve well in definitive endoderm induction followed by WNT3A specific signaling to direct the definitive endoderm into late endodermal lineages. Other combinations, though still feasible for endoderm induction, appear less promising for pancreatic endoderm specification in our experiments.
Human embryonic stem cells; Endoderm; Hierarchical clustering; Biclustering; Bootstrap