Genomic insights into high exopolysaccharide-producing dairy starter bacterium Streptococcus thermophilus ASCC 1275.

published_or_final_versio

Sox10 regulates enteric neural crest cell migration in the developing gut

Concurrent Sessions 1: 1.3 - Organs to organisms: Models of Human Diseases: abstract no. 1417th ISDB 2013 cum 72nd Annual Meeting of the Society for Developmental Biology, VII Latin American Society of Developmental Biology Meeting and XI Congreso de la Sociedad Mexicana de Biologia del Desarrollo. The Conference's web site is located at http://www.inb.unam.mx/isdb/Sox10 is a HMG-domain containing transcription factor which plays important roles in neural crest cell survival and differentiation. Mutations of Sox10 have been identified in patients with Waardenburg-Hirschsprung syndrome, who suffer from deafness, pigmentation defects and intestinal aganglionosis. Enteric neural crest cells (ENCCs) with Sox10 mutation undergo premature differentiation and fail to colonize the distal hindgut. It is unclear, however, whether Sox10 plays a role in the migration of ENCCs. To visualize the migration behaviour of mutant ENCCs, we generated a Sox10NGFP mouse model where EGFP is fused to the N-terminal domain of Sox10. Using time-lapse imaging, we found that ENCCs in Sox10NGFP/+ mutants displays lower migration speed and altered trajectories compared to normal controls. This behaviour was cell-autonomous, as shown by organotypic grafting of Sox10NGFP/+ gut segments onto control guts and vice versa. ENCCs encounter different extracellular matrix (ECM) molecules along the developing gut. We performed gut explant culture on various ECM and found that Sox10NGFP/+ ENCCs tend to form aggregates, particularly on fibronectin. Time-lapse imaging of single cells in gut explant culture indicated that the tightly-packed Sox10 mutant cells failed to exhibit contact inhibition of locomotion. We determined the expression of adhesion molecule families by qPCR analysis, and found integrin expression unaffected while L1-cam and selected cadherins were altered, suggesting that Sox10 mutation affects cell adhesion properties of ENCCs. Our findings identify a de novo role of Sox10 in regulating the migration behaviour of ENCCs, which has important implications for the treatment of Hirschsprung disease.postprin

Engineered magnesium-based resorbable porous scaffold for bone tissue engineering

INTRODUCTION: Bone tissue engineering offers an alternative solution to the traditional methods of bone replacement including allografts and autografts [1]. Although these biological materials possess good osteoinductive and osteoconductive properties, both of them have limitations in terms of the availability, donor site morbidity and the risk of disease transmission with the use of allografts [2]. Therefore, the use of synthetic scaffold is the most common technique and good approach to regenerate diseased or damaged bone tissue. An ideal bone substitute should possess certain properties including ...postprin

Low modulus novel bone substitutes for osteoporotic vertebral fracture management

Oral presentationpublished_or_final_versioneCM XIII - Bone Fixation, Repair & Regeneration, Davos Platz, Switzerland, 24-26 June 2012. In European Cells & Materials, 2012, v. 24 n. Suppl. 1, p. 1

Magnesium plasma modified bone allograft for Large Bone Defect Treatment

Invited TalkBone allograft is the most widely accepted approach in treating patients suffering from large segmental bone defect regardless of the advancement of synthetic bone substitutes[ I, 2]. However, the long-term complications of allograft application in term of delayed union or even nonunion were reported due to the stringent sterilization process prior to clinical implantation[3, 4]. Our previous studies demonstrated that the incorporation of magnesium ions (Mg2+) into biomaterials could …postprin

Dignity amidst liminality: Healing within suffering among Chinese terminal cancer patients

postprin

The effect of acupuncture duration on analgesia and peripheral sensory thresholds

<p>Abstract</p> <p>Background</p> <p>Acupuncture provides a means of peripheral stimulation for pain relief. However, the detailed neuronal mechanisms by which acupuncture relieves pain are still poorly understood and information regarding optimal treatment settings is still inadequate. Previous studies with a short burst of unilateral electroacupuncture (EA) in the Tendinomuscular Meridians (TMM) treatment model for pain demonstrated a transient dermatomally correlated bilateral analgesic effect with corresponding peripheral modality-specific sensory threshold alterations. However, the impact of EA duration on the analgesic effect in this particular treatment model is unknown. To obtain mechanistically and clinically important information regarding EA analgesia, this current prospective cross-over study assesses the effects of EA duration on analgesia and thermal sensory thresholds in the TMM treatment model.</p> <p>Methods</p> <p>Baseline peripheral sensory thresholds were measured at pre-marked testing sites along the medial aspects (liver and spleen meridians) of bilateral lower extremities. A 5-second hot pain stimulation was delivered to the testing sites and the corresponding pain Visual Analog Scale (VAS) scores were recorded. Three different EA (5Hz) stimulation durations (5, 15 and 30 minutes) were randomly tested at least one week apart. At the last 10 seconds of each EA session, 5 seconds of subject specific HP stimulation was delivered to the testing sites. The corresponding pain and EA VAS scores of de qi sensation (tingling) during and after the EA were recorded. The measurements were repeated immediately, 30 and 60 minutes after the EA stimulation. A four-factor repeat measures ANOVA was used to assess the effect of stimulation duration, time, location (thigh vs. calf) and side (ipsilateral vs. contralateral) of EA on sensory thresholds and HP VAS scores.</p> <p>Results</p> <p>A significant (P < 0.01) main effect of time and location with warm, cold and hot pain thresholds at the four testing sites without any significant difference in duration effect was observed. Similar time and location effects were observed with HP VAS with the longer durations (15 and 30 minutes) of stimulation showed a slower onset, but a more sustainable bilateral analgesic benefit than the short stimulation duration (5 minutes). The 15-minute stimulation resulted in an earlier onset of analgesic effect than the 30-minute stimulation paradigm.</p> <p>Conclusion</p> <p>Longer durations of EA stimulation provide a more sustainable analgesic benefit to hot noxious stimulation than a shorter duration of stimulation. The increase of cold threshold with sustained warm threshold temperature elevation as observed in the longer durations of EA suggests that as the duration of EA lengthened, there is a gradual shifting from an initial predominantly spinally mediated analgesic effect to a supraspinally mediated modulatory mechanism of thermal pain. The 15-minute stimulation appeared to be the optimal setting for treating acute pain in the lower extremities.</p

Circulating genotypes of porcine respiratory and reproductive syndrome viruses in southern China: re-emerging lineage 3 and genomic recombination with vaccine variants

Poster presentation: PRRS Epidemiology, Heterogeneity, and EvolutionPorcine reproductive and respiratory syndrome virus (PRRSV) was first reported in China since the end of 1995 and several variants were further reported in subsequence years, causing huge economic losses to Chinese swine industry. In 2006, a country-wide outbreak of porcine high fever syndrome, caused by a highly pathogenic PRRSV (HP-PRRSV) emerged in China affecting more than 20 million pigs. To date, three lineages (lineage 3, lineage 5.1 and lineage 8.7) of PRRSV were reported in China based on our global genotyping for type 2 PRRSV. Among these three lineages, only lineage 8.7 was the most significant variant where infected pigs showing severe clinical symptoms. Much investigation to this economically important lineage (lineage 8.7) caused lesser attention on other lineages in China during recent years. Based on our viral isolation in Guangdong Province of Southern China during 2009 and 2011, the majority of isolates collected were grouped as HP-PRRSV cluster. Moreover, circulating vaccine-associated lineage (lineage 5.1) and re-emerging lineage 3 isolates were also found. Lineage 3 was previously reported in China, Hong Kong and Taiwan, but there were no reports for this lineage after 2005 in China. Here, we present the re-emerging of this lineage 3 viruses in southern China in 2010 and their evolutionary story. Additionally, we had identified inter-lineage genomic recombination between MLV vaccine strain and re-emerging lineage 3 virus in a farm practicing MLV vaccination. Although modified live virus (MLV) vaccines provide solid protection against PRRSV infection, the safety of MLV vaccines has been questioned since the detection of vaccine revertants which caused productive problems similar to those of wild-type PRRSV. Based on our experimental study, no differences in virulence between the recombinant variant and wild-type lineage 3 were observed. However, further investigations on genomic recombination among PRRSV variants in China are needed.published_or_final_versio

Towards a metagenomic understanding on enhanced biomethane production from waste activated sludge after pH 10 pretreatment

BACKGROUND: Understanding the effects of pretreatment on anaerobic digestion of sludge waste from wastewater treatment plants is becoming increasingly important, as impetus moves towards the utilization of sludge for renewable energy production. Although the field of sludge pretreatment has progressed significantly over the past decade, critical questions concerning the underlying microbial interactions remain unanswered. In this study, a metagenomic approach was adopted to investigate the microbial composition and gene content contributing to enhanced biogas production from sludge subjected to a novel pretreatment method (maintaining pH at 10 for 8 days) compared to other documented methods (ultrasonic, thermal and thermal-alkaline). RESULTS: Our results showed that pretreated sludge attained a maximum methane yield approximately 4-fold higher than that of the blank un-pretreated sludge set-up at day 17. Both the microbial and metabolic consortium shifted extensively towards enhanced biodegradation subsequent to pretreatment, providing insight for the enhanced methane yield. The prevalence of Methanosaeta thermophila and Methanothermobacter thermautotrophicus, together with the functional affiliation of enzymes-encoding genes suggested an acetoclastic and hydrogenotrophic methanogenesis pathway. Additionally, an alternative enzymology in Methanosaeta was observed. CONCLUSIONS: This study is the first to provide a microbiological understanding of improved biogas production subsequent to a novel waste sludge pretreatment method. The knowledge garnered will assist the design of more efficient pretreatment methods for biogas production in the future.published_or_final_versio

A dual protein expression system in Bacillus subtilis

We have developed a dual expression system for the simultaneous overexpression of two proteins in Bacillus subtilis. Two candidate genes, xylanase (xynA) and glucanase (bglS) from B. subtilis strain 168, which were engineered with independent Shine-Dalgarno (SD) sequences, were cloned in tandem into a transfer vector, which was then transformed into B. subtilis strain 1A304 (φ105MU331). The genes were under the transcriptional control of a strong promoter of a bacteriophage, φ105, where transcription was initiated upon thermal induction. Six constructs were made to compare the factors that affected the yields of the gene products. The expression level of each candidate gene was found to correspond to its position relative to the phage promoter, irrespective of the identity of the insert. The lower expression level of the second insert might have been due to limited resources for protein synthesis, a short half-life of the mRNA, or an early termination of the RNA polymerase. Curiously, gene duplications in tandem did not lead to further increase in production. © 2002 Elsevier Science (USA). All rights reserved.postprin