MAST3: a novel IBD risk factor that modulates TLR4 signaling

Inflammatory bowel disease (IBD) is a chronic disorder caused by multiple factors in a genetically susceptible host. Significant advances in the study of genetic susceptibility have highlighted the importance of the innate immune system in this disease. We previously completed a genome-wide linkage study and found a significant locus (IBD6) on chromosome 19p. We were interested in identifying the causal variant in IBD6. We performed a two-stage association mapping study. In stage 1, 1530 single-nucleotide polymorphisms (SNPs) were selected from the HapMap database and genotyped in 761 patients with IBD. Among the SNPs that passed the threshold for replication, 26 were successfully genotyped in 754 additional patients (stage 2). One intronic variant, rs273506, located in the microtubule-associated serine/threonine-protein kinase gene-3 (MAST3), was found to be associated in both stages (pooled P=1.8 x 10(-4)). We identified four MAST3 coding variants, including a non-synonymous SNP rs8108738, correlated to rs273506 and associated with IBD. To test whether MAST3 was expressed in cells of interest, we performed expression assays, which showed abundant expression of MAST3 in antigen-presenting cells and in lymphocytes. The knockdown of MAST3 specifically decreased Toll-like receptor-4-dependent NF-kappaB activity. Our findings are additional proofs of the pivotal role played by modulators of NF-kappaB activity in IBD pathogenesis.

Curcumin: from ancient medicine to current clinical trials

Curcumin is the active ingredient in the traditional herbal remedy and dietary spice turmeric (Curcuma longa). Curcumin has a surprisingly wide range of beneficial properties, including anti-inflammatory, antioxidant, chemopreventive and chemotherapeutic activity. The pleiotropic activities of curcumin derive from its complex chemistry as well as its ability to influence multiple signaling pathways, including survival pathways such as those regulated by NF-kappaB, Akt, and growth factors; cytoprotective pathways dependent on Nrf2; and metastatic and angiogenic pathways. Curcumin is a free radical scavenger and hydrogen donor, and exhibits both pro- and antioxidant activity. It also binds metals, particularly iron and copper, and can function as an iron chelator. Curcumin is remarkably non-toxic and exhibits limited bioavailability. Curcumin exhibits great promise as a therapeutic agent, and is currently in human clinical trials for a variety of conditions, including multiple myeloma, pancreatic cancer, myelodysplastic syndromes, colon cancer, psoriasis and Alzheimer's disease.

Light-extraction enhancement of vertical-injection GaN-based light-emitting diodes fabricated with highly integrated surface textures

We report on the fabrication of high-efficiency vertical-injection GaN-based light-emitting diodes (LEDs) fabricated with integrated surface textures. An optical ray-tracing simulation shows that the high integration of surface textures can effectively enhance the light-extraction efficiency. The integrated surface textures are fabricated on the top surface of LEDs by generating hexagonal cones on the periodically corrugated surfaces of n-GaN. Compared to reference LEDs without textures, LEDs fabricated with integrated surface textures show an enhancement of the output power by a factor of 2.59, which is in agreement with the calculated results.

Comparison of the GlideScope video laryngoscope and Macintosh laryngoscope in simulated tracheal intubation scenarios

OBJECTIVE

To compare the GlideScope video laryngoscope (GVL) with the classic Macintosh laryngoscope in simulated airway scenarios of varying difficulty.

MATERIALS AND METHODS

A prospective, crossover and randomised study was performed. Four airway scenarios were simulated using the Airsim model as follows: normal; cervical spine immobilisation; tongue oedema and combined cervical spine immobilisation with tongue oedema. Emergency physicians performed tracheal intubations using both devices in each of the scenarios. The time required to intubate, the success rate and the number of intubation attempts were recorded. At the end of each scenario, participants scored vocal cord visualisation using the percentage of glottic opening (POGO) visible and the subjective ease of intubation on a visual analogue scale (VAS).

RESULTS

All 25 participants successfully completed the study. There was no difference in the time required for successful tracheal intubation using the GVL compared with using the Macintosh laryngoscope in the four airway scenarios. Only one participant failed to intubate the trachea with the Macintosh laryngoscope for the combined scenario. There was a significant increase in POGO when using the GVL in the cervical spine immobilisation group (p = 0.027). The VAS score of the subjective ease of intubation was lower for the GVL than for the Macintosh laryngoscope device in difficult scenarios but this difference was not significant.

CONCLUSION

This study suggests that the GVL could be an option for airway management even by emergency physicians with little experience and no training in its use.

Carbon nanotube-nanocrystal heterostructures fabricated by electrophoretic deposition

Alternating layer, carbon nanotubes-nanocrystal composite films, comprising multi-walled carbon nanotubes (MWCNTs) and iron oxide (Fe(3)O(4)) nanocrystals, have been fabricated via electrophoretic deposition (EPD) on stainless steel and gold substrates. Low field-high current and high field-low current EPD schemes were integrated to produce the composite films. The low field-high current EPD approach produced porous mats from an aqueous suspension of the MWCNTs, while the high field-low current EPD approach produced tightly packed nanocrystal films from a dispersion of the nanocrystals in hexane. Large electric fields applied during the nanocrystal EPD and strong van der Waals interactions among the nanocrystals facilitated the formation of tightly packed nanocrystal films atop the MWCNT mats to create CNT mat-nanocrystal film composites. The surface coverage and homogeneity of the nanocrystal films improved with repeated deposition of the nanocrystals on the same mat. The assembly of nanotube mats on top of the CNT mat-nanocrystal film composite confirmed the feasibility of multilayered CNT mat-nanocrystal film heterostructures suitable for a range of devices. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques were employed to characterize the surface coverage, homogeneity, and topology of these composite films.

Gene-centric association mapping of chromosome 3p implicates MST1 in IBD pathogenesis

Association mapping and candidate gene studies within inflammatory bowel diseases (IBD) linkage regions, as well as genome-wide association studies in Crohn's disease (CD) have led to the discovery of multiple risk genes, but these explain only a fraction of the genetic susceptibility observed in IBD. We have thus been pursuing a region on chromosome 3p21-22 showing linkage to CD and ulcerative colitis (UC) using a gene-centric association mapping approach. We identified 12 functional candidate genes by searching for literature cocitations with relevant keywords and for gene expression patterns consistent with immune/intestinal function. We then performed an association study composed of a screening phase, where tagging single nucleotide polymorphisms (SNPs) were evaluated in 1,020 IBD patients, and an independent replication phase in 745 IBD patients. These analyses identified and replicated significant association with IBD for four SNPs within a 1.2 Mb linkage disequilibrium region. We then identified a non-synonymous coding variant (rs3197999, R689C) in the macrophage-stimulating 1 (MST1) gene (P-value 3.62 x 10(-6)) that accounts for the association signal, and shows association with both CD and UC. MST1 encodes macrophage-stimulating protein (MSP), a protein regulating the innate immune responses to bacterial ligands. R689C is predicted to interfere with MSP binding to its receptor, suggesting a role for this gene in the pathogenesis of IBD.

A facility for characterizing the steady-state and dynamic thermal performance of microelectromechanical system thermal switches

A facility to characterize microelectromechanical system (MEMS) thermal switches by measuring two pertinent figures of merit is described. The two figures of merit measured are the ratio of thermal resistance of the switch in the off and on states, Roff/Ron, and the time required to switch from the off to the on state, tauswitch. The facility consists of two pieces of equipment. A guard-heated calorimeter is used to measure heat transfer across the thermal switch under steady-state conditions. Measuring heat transfer across a thermal switch in both the off and on states then gives the thermal resistance ratio Roff/Ron. A thin-film radial heat-flux sensor is used to measure heat transfer across the thermal switch under dynamic conditions. Measuring heat transfer across a thermal switch as the switch changes from the off to the on state gives the thermal switching time tauswitch. The test facilities enable the control of the applied force on the thermal switch when the thermal switch is on, the thickness of the gas gap when the thermal switch is off, and the gas species and pressure in the thermal switch gas gap. The thermal performance of two MEMS thermal switches employing two different thermal contact materials, a polished silicon surface and an array of liquid-metal microdroplets, is characterized and compared.

An SNP linkage scan identifies significant Crohn's disease loci on chromosomes 13q13.3 and, in Jewish families, on 1p35.2 and 3q29

Inflammatory bowel disease (IBD) is a complex genetic disorder of two major phenotypes, Crohn's disease (CD) and ulcerative colitis (UC), with increased risk in Ashkenazi Jews. Twelve genome-wide linkage screens have identified multiple loci, but these screens have been of modest size and have used low-density microsatellite markers. We, therefore, performed a high-density single-nucleotide polymorphism (SNP) genome-wide linkage study of 993 IBD multiply affected pedigrees (25% Jewish ancestry) that contained 1709 IBD-affected relative pairs, including 919 CD-CD pairs and 312 UC-UC pairs. We identified a significant novel CD locus on chromosome 13p13.3 (peak logarithm of the odds (LOD) score=3.98) in all pedigrees, significant linkage evidence on chromosomes 1p35.1 (peak LOD score=3.5) and 3q29 (peak LOD score=3.19) in Jewish CD pedigrees, and suggestive loci for Jewish IBD on chromosome 10q22 (peak LOD score=2.57) and Jewish UC on chromosome 2q24 (peak LOD score=2.69). Nominal or greater linkage evidence was present for most previously designated IBD loci (IBD1-9), notably, IBD1 for CD families at chromosome 16q12.1 (peak LOD score=4.86) and IBD6 in non-Jewish UC families at chromosome 19p12 (peak LOD score=2.67). This study demonstrates the ability of high information content adequately powered SNP genome-wide linkage studies to identify loci not observed in multiple microsatellite-based studies in smaller cohorts.

Distal lenticulostriate artery aneurysm in deep intracerebral haemorrhage

Aneurysms of the distal lenticulostriate artery (LSA) are rare. Only 16 cases have been reported in the literature. Early detection and treatment of these aneurysms is also difficult because of their deep location, small size and angioarchitecture. We report two additional patients with aneurysms, arising from the distal LSA, who presented with deep intracerebral haemorrhage. The conclusions drawn from our experience and a comprehensive review of the literature include the following. (1) A distal LSA aneurysm should be considered in young (mean 38.5 years) and non-hypertensive (80%) patients with deep intracerebral haemorrhage. (2) These aneurysms are frequently very small (<5 mm). Therefore, they cannot be detected on initial angiograms in some cases. (3) These aneurysms have higher rates of associated vascular lesions. Deep intracerebral haemorrhage, even in those over the age of 50 years, can still be due to underlying, treatable structural abnormalities, and should not be dismissed as being a result of hypertension. In addition, a more comprehensive diagnostic approach seems to be warranted in younger patients and those without known hypertension.

Determining the Amount of Rumen-Protected Methionine Supplement That Corresponds to the Optimal Levels of Methionine in Metabolizable Protein for Maximizing Milk Protein Production and Profit on Dairy Farms

The profitability of feeding rumen-protected Met (RPMet) sources to produce milk protein was estimated using a 2-step procedure: First, the effect of Met in metabolizable protein (MP) on milk protein production was estimated by using a quadratic Box-Cox functional form. Then, using these estimation results, the amounts of RPMet supplement that corresponded to the optimal levels of Met in MP for maximizing milk protein production and profit on dairy farms were determined. The data used in this study were modified from data used to determine the optimal level of Met in MP for lactating cows in the Nutrient Requirements of Dairy Cattle (NRC, 2001). The data used in this study differ from that in the NRC (2001) data in 2 ways. First, because dairy feed generally contains 1.80 to 1.90% Met in MP, this study adjusts the reference production value (RPV) from 2.06 to 1.80 or 1.90%. Consequently, the milk protein production response is also modified to an RPV of 1.80 or 1.90% Met in MP. Second, because this study is especially interested in how much additional Met, beyond the 1.80 or 1.90% already contained in the basal diet, is required to maximize farm profits, the data used are limited to concentrations of Met in MP above 1.80 or 1.90%. This allowed us to calculate any additional cost to farmers based solely on the price of an RPMet supplement and eliminated the need to estimate the dollar value of each gram of Met already contained in the basal diet. Results indicated that the optimal level of Met in MP for maximizing milk protein production was 2.40 and 2.42%, where the RPV was 1.80 and 1.90%, respectively. These optimal levels were almost identical to the recommended level of Met in MP of 2.40% in the NRC (2001). The amounts of RPMet required to increase the percentage of Met in MP from each RPV to 2.40 and 2.42% were 21.6 and 18.5 g/d, respectively. On the other hand, the optimal levels of Met in MP for maximizing profit were 2.32 and 2.34%, respectively. The amounts of RPMet required to increase the percentage of Met in MP from each RPV to 2.32 and 2.34% were 18.7 and 15.6 g/d, respectively. In each case, the additional daily profit per cow was estimated to be $0.38 and $0.29. These additional profit estimates were $0.02 higher than the additional profit estimates for maximizing milk protein production.