Preliminary survey of pests and diseases of eucheumatoid seaweed farms in the Philippines

Journal of Applied Phycology - Farmed eucheumatoids are the top aquaculture commodity in the Philippines, contributing more than 60% of total national aquaculture production by volume. Despite...     

A time course study on dose-response relationship between alcohol exposure and its effects on lipid profile and biomarkers of tissue damage

This present research investigated variations in lipid profiles and important biomarkers of tissue damage in response to graded concentrations of alcohol administration in male Wistar rats. Group A (control) received distilled water while group B, C and D received 30%, 40% and 50% (v/v) alcohol respectively. Five rats each from groups A-D were sacrificed after day(s) 1, 7, 14, 21 and 28 of administration. A significant increase was observed at day 28 for serum cholesterol by 79% (group B), 78% (group C) and 47% (group D) together with serum phospholipid 58% (group B), 50% (group C) and 92% (group D). Serum triacylglycerol increased by 71% (group B), 43% (group C) and 16% (group D) at day 21, while concentration of serum albumin decreased at day 28 by 40.9% (group B), 50.2% (group C), 53.3% (group D) respectively when compared with control (group A). Serum aminotransferases and alkaline phosphatase specific activities, as well as creatinine and uric acid concentration increased in a concentration-dependent manner, following alcohol administration. Though most of these effects induced by alcohol were time- and concentration-dependent, 40% alcohol appear to be more stable, giving results consistent with alcohol-induced damages, with minimal mortality. This study therefore further validated dyslipidemia and imbalance in clinical biomarkers as hallmarks of tissue damage induced by excessive alcohol consumption with an insight on the time- and concentration-response relationship between alcohol consumption and its toxicity.     

Genome-wide analysis reveals an unexpected function for the Drosophila splicing factor U2AF50 in the nuclear export of intronless mRNAs

The protein factor U2AF is an essential component required for pre-mRNA splicing. Mutations identified in the S. pombe large U2AF subunit were used to engineer transgenic Drosophila carrying temperature-sensitive U2AF large subunit alleles. Mutant recombinant U2AF heterodimers showed reduced polypyrimidine tract RNA binding at elevated temperatures. Genome-wide RNA profiling comparing wild-type and mutant strains identified more than 400 genes differentially expressed in the dU2AF50 mutant flies grown at the restrictive temperature. Surprisingly, almost 40% of the downregulated genes lack introns. Microarray analyses revealed that nuclear export of a large number of intronless mRNAs is impaired in Drosophila-cultured cells RNAi knocked down for dU2AF50. Immunopurification of nuclear RNP complexes showed that dU2AF50 associates with intronless mRNAs. These results reveal an unexpected role for the splicing factor dU2AF50 in the nuclear export of intronless mRNAs.     

Transcriptional regulation of ATP-binding cassette transporter A1 expression by a novel signaling pathway

ATP-binding cassette transporter A1 (ABCA1) is a membrane-bound protein that regulates the efflux of cholesterol derived from internalized lipoproteins. Using a mouse macrophage cell line, this report studied the impact of low-density lipoproteins (LDL) on ABCA1 expression and the signaling pathway responsible for lipoprotein-induced ABCA1 expression. Our data demonstrated that treatment of macrophages with LDL increased ABCA1 mRNA and protein levels 4.3- and 3.5-fold, respectively. LDL also induced an ～2-fold increase in macrophage surface expression of ABCA1 and a 14-fold-increase in apolipoprotein AI-mediated cholesterol efflux. In addition, LDL significantly increased the level of phosphorylated specificity protein 1 (Sp1) and the amount of Sp1 bound to the ABCA1 promoter without alteration in total Sp1 protein level. Mutation of the Sp1 binding site in the ABCA1 promoter and inhibition of Sp1 DNA binding with mithramycin A suppressed the ABCA1 promoter activity and reduced the ABCA1 expression level induced by LDL. LDL treatment also elevated protein kinase C-ζ (PKC-ζ) phosphorylation and induced PKC-ζ binding with Sp1. Inhibition of PKC-ζ with kinase inhibitors or overexpression of kinase-dead PKC-ζ attenuated Sp1 phosphorylation and ABCA1 expression induced by LDL. These results demonstrate for the first time that activation of the PKCζ-Sp1 signaling cascade is a mechanism for regulation of LDL-induced ABCA1 expression.     

The expanding interleukin-1 family and its receptors: do alternative IL-1 receptor/signaling pathways exist in the brain?

Interleukin-1 (IL-1) has been implicated in neuroimmune responses and has pleiotropic actions in the brain. Compelling evidence has shown that IL-1 is a major mediator of inflammation and the progression of cell death in response to brain injury and cerebral ischemia. Its expression is strongly increased in these pathological conditions, and central administration of exogenous IL-1 significantly exacerbates ischemic brain damage. In contrast, inhibiting IL-1 actions (by intracerebroventricular [icv] injection of IL-1ra, neutralizing antibody to IL-1 or caspase-1 inhibitor) significantly reduces ischemic brain damage. IL-1 acts by binding to the IL-1 type-1 receptor (IL-1RI), which is to date, the only known functional receptor for IL-1. However, our recent investigations suggest that IL-1 can act independently of IL-1RI, raising the possibility that additional, as yet undiscovered, receptor(s) for IL-1 exist in the brain. The recent characterization of putative, new IL-1 ligands and new IL-1 receptor-related molecules leads to the hypothesis that there might be alternative IL-1 signaling pathway(s) in the central nervous system (CNS).     

Insight on specificity of uracil permeases of the NAT/NCS2 family from analysis of the transporter encoded in the pyrimidine utilization operon of Escherichia coli

The uracil permease UraA of Escherichia coli is a structurally known prototype for the ubiquitous Nucleobase‐Ascorbate Transporter (NAT) or Nucleobase‐Cation Symporter‐2 (NCS2) family and represents a well‐defined subgroup of bacterial homologs that remain functionally unstudied. Here, we analyze four of these homologs, including RutG of E. coli which shares 35% identity with UraA and is encoded in the catabolic rut (pyr imidine ut ilization) operon. Using amplified expression in E. coli K‐12, we show that RutG is a high‐affinity permease for uracil, thymine and, at low efficiency, xanthine and recognizes also 5‐fluorouracil and oxypurinol. In contrast, UraA and the homologs from Acinetobacter calcoaceticus and Aeromonas veronii are permeases specific for uracil and 5‐fluorouracil. Molecular docking indicates that thymine is hindered from binding to UraA by a highly conserved Phe residue which is absent in RutG. Site‐directed replacement of this Phe with Ala in the three uracil‐specific homologs allows high‐affinity recognition and/or transport of thymine, emulating the RutG profile. Furthermore, all RutG orthologs from enterobacteria retain an Ala at this position, implying that they can use both uracil and thymine and, possibly, xanthine as substrates and provide the bacterial cell with a range of catabolizable nucleobases.     

High prevalence of malaria in Zambezia, Mozambique: the protective effect of IRS versus increased risks due to pig-keeping and house construction

Background

African countries are scaling up malaria interventions, especially insecticide treated nets (ITN) and indoor residual spraying (IRS), for which ambitious coverage targets have been set. In spite of these efforts infection prevalence remains high in many parts of the continent. This study investigated risk factors for malaria infection in children using three malaria indicator surveys from Zambezia province, Mozambique. The impact of IRS and ITNs, the effects of keeping farm animals and of the construction material of roofs of houses and other potential risk factors associated with malaria infection in children were assessed.

Methods

Cross-sectional community-based surveys were conducted in October of 2006, 2007 and 2008. A total of 8338 children (ages 1–15 years) from 2748 households were included in the study. All children were screened for malaria by rapid diagnostic tests. Caregiver interviews were used to assess household demographic and wealth characteristics and ITN and IRS coverage. Associations between malaria infection, vector control interventions and potential risk factors were assessed.

Results

Overall, the prevalence of malaria infection was 47.8% (95%CI: 38.7%–57.1%) in children 1–15 years of age, less than a quarter of children (23.1%, 95%CI: 19.1%–27.6%) were sleeping under ITN and almost two thirds were living in IRS treated houses (coverage 65.4%, 95%CI: 51.5%–77.0%). Protective factors that were independently associated with malaria infection were: sleeping in an IRS house without sleeping under ITN (Odds Ratio (OR)  = 0.6; 95%CI: 0.4–0.9); additional protection due to sleeping under ITN in an IRS treated house (OR = 0.5; 95%CI: 0.3–0.7) versus sleeping in an unsprayed house without a ITN; and parental education (primary/secondary: OR = 0.6; 95%CI: 0.5–0.7) versus parents with no education. Increased risk of infection was associated with: current fever (OR = 1.2; 95%CI: 1.0–1.5) versus no fever; pig keeping (OR = 3.2; 95%CI: 2.1–4.9) versus not keeping pigs; living in houses with a grass roof (OR = 1.7; 95%CI: 1.3–2.4) versus other roofing materials and bigger household size (8–15 people: OR = 1.6; 95%CI: 1.3–2.1) versus small households (1–4 persons).

Conclusion

Malaria infection among children under 15 years of age in Zambezia remained high but conventional malaria vector control methods, in particular IRS, provided effective means of protection. Household ownership of farm animals, particularly pigs, and living in houses with a grass roof were independently associated with increased risk of infection, even after allowing for household wealth. To reduce the burden of malaria, national control programs need to ensure high coverage of effective IRS and promote the use of ITNs, particularly in households with elevated risks of infection, such as those keeping farm animals, and those with grass roofs.     

Fear-like behavioral responses in mice in different odorant environments: Trigeminal versus olfactory mediation under low doses

Odors can have repulsive effects on rodents based on two complementary adaptive behaviors: the avoidance of predator odors (potentially dangerous) and the avoidance of trigeminal stimulants (potentially noxious). The present study aimed to compare the behavioral effects on mice of odors according to their trigeminal properties and ecological significance. We used three different odors: 2,4,5-trimethylthiazoline (TMT: a fox feces odor frequently used to elicit fear-induced behaviors), toluene (a strong stimulant of the trigeminal system) and phenyl ethyl alcohol (PEA: a selective stimulant of the olfactory system). First, we checked preference and avoidance behaviors in mice with and without anosmia towards these odors to ensure their olfactory/trigeminal properties. Secondly, we used a standard test (open-field and elevated plus-maze) to assess the behaviors of mice when exposed to these odors. The results show that the anosmic and control mice both avoided TMT and toluene odors. In the open-field and the elevated plus-maze, mice exhibited "anxious" behaviors when exposed to TMT. Conversely, exposure to PEA induced "anxiolytic" effects confirmed by low blood corticosterone levels resulting from completion of the elevated plus-maze. Compared with TMT exposure, toluene exposure induced moderate "anxious" effects.