Host Determinants of Helicobacter pylori Infection and Its Clinical Outcome

Greater than one-half of the world's population harbors Helicobacter pylori. The majority of infected individuals, however, remain asymptomatic, with only 10% to 20% developing diseases, including peptic ulcer disease, gastric cancer, and gastric mucosa–associated lymphoid tissue lymphoma. This article reviews host factors that may predispose an individual to both the acquisition of H. pylori infection and subsequent clinical outcome. Individuals with specific blood group antigens and human leukocyte antigen genotypes may be more susceptible to H. pylori infection. Additional factors, such as the age of acquisition, the host immune response, the site of infection, acid secretion, and interactions with nonhost factors (including bacterial virulence factors and environmental influences) may play a role in determining clinical outcome. Further investigation is required to clarify the mechanisms by which these interactions occur and, more critically, to determine their relative importance. This knowledge will enable the identification of individuals at risk of developing clinical disease with H. pylori infection.     

Pulsed electromagnetic fields promote repair of focal articular cartilage defects with engineered osteochondral constructs

Articular cartilage injuries are a common source of joint pain and dysfunction. We hypothesized that pulsed electromagnetic fields (PEMFs) would improve growth and healing of tissue-engineered cartilage grafts in a direction-dependent manner. PEMF stimulation of engineered cartilage constructs was first evaluated in vitro using passaged adult canine chondrocytes embedded in an agarose hydrogel scaffold. PEMF coils oriented parallel to the articular surface induced superior repair stiffness compared to both perpendicular PEMF (p = .026) and control (p = .012). This was correlated with increased glycosaminoglycan deposition in both parallel and perpendicular PEMF orientations compared to control (p = .010 and .028, respectively). Following in vitro optimization, the potential clinical translation of PEMF was evaluated in a preliminary in vivo preclinical adult canine model. Engineered osteochondral constructs (∅ 6 mm × 6 mm thick, devitalized bone base) were cultured to maturity and implanted into focal defects created in the stifle (knee) joint. To assess expedited early repair, animals were assessed after a 3-month recovery period, with microfracture repairs serving as an additional clinical control. In vivo, PEMF led to a greater likelihood of normal chondrocyte (odds ratio [OR]: 2.5, p = .051) and proteoglycan (OR: 5.0, p = .013) histological scores in engineered constructs. Interestingly, engineered constructs outperformed microfracture in clinical scoring, regardless of PEMF treatment (p < .05). Overall, the studies provided evidence that PEMF stimulation enhanced engineered cartilage growth and repair, demonstrating a potential low-cost, low-risk, noninvasive treatment modality for expediting early cartilage repair.     

Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material fabrication techniques are able to mimic the complexity of these structures while maintaining scalability. The Vaporization of a Sacrificial Component (VaSC) process is able to do so. This process uses sacrificial fibers as a template to form hollow, cylindrical microchannels embedded within a matrix. Tin (II) oxalate (SnOx) is embedded within poly(lactic) acid (PLA) fibers which facilitates the use of this process. The SnOx catalyzes the depolymerization of the PLA fibers at lower temperatures. The lactic acid monomers are gaseous at these temperatures and can be removed from the embedded matrix at temperatures that do not damage the matrix. Here we show a method for aligning these fibers using micromachined plates and a tensioning device to create complex patterns of three-dimensionally arrayed microchannels. The process allows the exploration of virtually any arrangement of fiber topologies and structures.     

Evaluation of characteristic aroma compounds of Citrus natsudaidai Hayata (Natsudaidai) cold-pressed peel oil

The characteristic aroma compounds of Citrus natsudaidai Hayata essential oil were evaluated by a combination of instrumental and sensory methods. Sixty compounds were identified and quantified, accounting for 94.08% of the total peel oil constituents. Limonene was the most abundant compound (80.68%), followed by gamma-terpinene (5.30%), myrcene (2.25%) and alpha-pinene (1.30%). Nineteen compounds which could not be identified in the original oil were identified in the oxygenated fraction. Myrcene, linalool, alpha-pinene, beta-pinene, limonene, nonanal, gamma-terpinene, germacrene D, and perillyl alcohol were the active aroma components (FD-factor > 3(6)), whereas beta-copaene, cis-sabinene hydrate and 1-octanol were suggested as characteristic aroma compounds, having a Natsudaidai-like aroma in the GC effluent. Three other compounds, heptyl acetate, (E)-limonene oxide and 2,3-butanediol, which each showed a high RFA value (>35) were considered to be important in the reconstruction of the original Natsudaidai oil from pure odor chemicals. The results indicate that 1-octanol was the aroma impact compound of C. natsudaidai Hayata peel oil.     

CCL5/CCR5 axis promotes the motility of human oral cancer cells

CCL5 (previously called RANTES) is in the CC‐chemokine family and plays a crucial role in the migration and metastasis of human cancer cells. On the other hand, the effect of CCL5 is mediated via CCR receptor. RT‐PCR and flow cytometry studies demonstrated CCR5 but not CCR1 and CCR3 mRNA in oral cancer cell lines, especially higher in those with high invasiveness (SCC4) as compared with lower levels in HSC3 cells and SCC9 cells. Stimulation of oral cancer cells with CCL5 directly increased the migration and metalloproteinase‐9 (MMP‐9) production. MMP‐9 small interfering RNA inhibited the CCL5‐induced MMP‐9 expression and thereby significantly inhibited the CCL5‐induced cell migration. Activations of phospholipase C (PLC), protein kinase Cδ (PKCδ), and NF‐κB pathways after CCL5 treatment was demonstrated, and CCL5‐induced expression of MMP‐9 and migration activity was inhibited by the specific inhibitor of PLC, PKCδ, and NF‐κB cascades. In addition, migration‐prone sublines demonstrate that cells with increasing migration ability had more expression of MMP‐9, CCL5, and CCR5. Taken together, these results indicate that CCL5/CCR5 axis enhanced migration of oral cancer cells through the increase of MMP‐9 production. J. Cell. Physiol. 220: 418–426, 2009. © 2009 Wiley‐Liss, Inc.     

Mapping quantitative trait loci for root development under hypoxia conditions in soybean (<Emphasis Type="Italic">Glycine max</Emphasis> L. Merr.)

Key message

Greatest potential, QTLs for hypoxia and waterlogging tolerance in soybean roots were detected using a new phenotypic evaluation method.

Abstract

Waterlogging is a major environmental stress limiting soybean yield in wet parts of the world. Root development is an important indicator of hypoxia tolerance in soybean. However, little is known about the genetic control of root development under hypoxia. This study was conducted to identify quantitative trait loci (QTLs) responsible for root development under hypoxia. Recombinant inbred lines (RILs) developed from a cross between a hypoxia-sensitive cultivar, Tachinagaha, and a tolerant landrace, Iyodaizu, were used. Seedlings were subjected to hypoxia, and root development was evaluated with the value change in root traits between after and before treatments. We found 230 polymorphic markers spanning 2519.2 cM distributed on all 20 chromosomes (Chrs.). Using these, we found 11 QTLs for root length (RL), root length development (RLD), root surface area (RSA), root surface area development (RSAD), root diameter (RD), and change in average root diameter (CARD) on Chrs. 11, 12, 13 and 14, and 7 QTLs for hypoxia tolerance of these root traits. These included QTLs for RLD and RSAD between markers Satt052 and Satt302 on Chr. 12, which are important markers of hypoxia tolerance in soybean; those QTLs were stable between 2 years. To validate the QTLs, we developed a near-isogenic line with the QTL region derived from Iyodaizu. The line performed well under both hypoxia and waterlogging, suggesting that the region contains one or more genes with large effects on root development. These findings may be useful for fine mapping and positional cloning of gene responsible for root development under hypoxia.

     

Functional conservation of an insect odorant receptor gene across 250 million years of evolution

Pest insects have a profound negative impact on agriculture and human health. Significant global losses of crops, stored agricultural products, timber and livestock can be attributed to damage and destruction by insects . Blood-feeding insects such as mosquitoes, flies and ticks transmit many of humanity's most devastating infectious diseases. Insect-borne diseases account for more than one million annual fatalities, and insect-associated illnesses surpass 300 million annual reported cases . The medical and economic impact of these animals can be ascribed in part to the sensitivity and selectivity of their olfactory systems, essential for location of their preferred plant and animal hosts.     

L-type Ca2+ currents in ventricular myocytes from neonatal and adult rats

Postnatal changes in the slow Ca2+ current (I(Ca)(L)) were investigated in freshly isolated ventricular myocytes from neonatal (1-7 days old) and adult (2-4 months old) rats, using whole-cell voltage clamp and single-channel recordings. The membrane capacitance (mean+/-SEM) averaged 23.2+/-0.5 pF in neonates (n = 163) and 140+/-4.1 pF in adults (n = 143). I(Ca)(L) was measured as the peak inward current at a test potential of +10 mV (or +20 mV) by applying a 300-ms pulse from a holding potential of -40 mV; 1.8 mM Ca2+ was used as charge carrier. The basal ICa(L) density was 6.7+/-0.2 pA/pF in neonatal and 7.8+/-0.2 pA/pF in adult cells (p < 0.05). The time course of inactivation of the fast component (at +10 ms) was significantly longer in the neonatal (10.7+/-1.4 ms) than in the adult (6.6+/-0.4 ms) cells (p < 0.05). Ryanodine (10+/-M) significantly increased this value to 18.0+/-1.9 in neonate (n = 8) and to 17.7+/-2.0 in adult (n = 9). For steady-state inactivation, the half-inactivation potential (Vh) was not changed in either group. For steady-state activation, Vh was 5.1 mV in the neonatal (n = 6) and -7.9 mV in the adult cells (n = 7). Single-channel recordings revealed that long openings (mode-2 behavior) were occasionally observed in the neonatal cells (11 events from 1080 traces/11 cells), but not in the adult cells (400 traces/4 cells). Slope conductance was 24 pS in both the neonatal and adult cells. Results in rat ventricular myocytes suggest the following: (i) the peak Ca2+ current density is already well developed in the neonatal period (being about 85% of the adult value); (ii) the fast component of inactivation is slower in neonates than in adults; and (iii) naturally occurring long openings are occasionally observed in the neonatal stage but not in the adult. Thus, the L-type Ca2+ channels of the neonate were slightly lower in density, were inactivated more slowly, and occasionally exhibited mode-2 behavior as compared with those of the adult.