Identification of a Secreted Fatty Acid and Retinol-Binding Protein (Hp-FAR-1) from Heligmosomoides polygyrus

Hp-FAR-1 is a major, secreted antigen of the parasitic nematode Heligmosomoides polygyrus, a laboratory mouse model frequently used to study the cellular mechanisms of chronic helminth infections. The DNA encoding Hp-FAR-1 was recovered by screening a fourth larval (L(4)) H. polygyrus cDNA expression library using antibodies raised against L(4) stage excretory/secretory (E/S) proteins. Predictions of secondary structure based on the Hp-FAR-1 amino acid sequence indicated that an alpha-helix predominates in Hp-FAR-1, possibly with some coiled-coil conformation, with no beta-structure. Fluorescence-based ligand binding analysis confirmed that the recombinant Hp-FAR-1 (rHp-FAR-1) binds the fluorescent fatty acid analog 11-((5-[dimethylaminoaphthalene-1-sulfonyl)amino)undecanoic acid (DAUDA), and by competition oleic acid. RT-PCR amplification of the hp-far-1 gene indicated that the gene is transcribed in all parasitic stages of the organism's life cycle. The presence of a secreted FAR protein in the well-defined laboratory model of H. polygyrus provides an excellent model for the further study and analysis of the in vivo role of secreted FAR proteins in parasitism, and supports the mounting evidence that secreted FAR proteins play a major role in nematode parasitism.     

Inhibition of Rho‐kinase protects cerebral barrier from ischaemia‐evoked injury through modulations of endothelial cell oxidative stress and tight junctions

Ischaemic strokes evoke blood–brain barrier (BBB) disruption and oedema formation through a series of mechanisms involving Rho‐kinase activation. Using an animal model of human focal cerebral ischaemia, this study assessed and confirmed the therapeutic potential of Rho‐kinase inhibition during the acute phase of stroke by displaying significantly improved functional outcome and reduced cerebral lesion and oedema volumes in fasudil‐ versus vehicle‐treated animals. Analyses of ipsilateral and contralateral brain samples obtained from mice treated with vehicle or fasudil at the onset of reperfusion plus 4 h post‐ischaemia or 4 h post‐ischaemia alone revealed these benefits to be independent of changes in the activity and expressions of oxidative stress‐ and tight junction‐related parameters. However, closer scrutiny of the same parameters in brain microvascular endothelial cells subjected to oxygen–glucose deprivation ± reperfusion revealed marked increases in prooxidant NADPH oxidase enzyme activity, superoxide anion release and in expressions of antioxidant enzyme catalase and tight junction protein claudin‐5. Cotreatment of cells with Y‐27632 prevented all of these changes and protected in vitro barrier integrity and function. These findings suggest that inhibition of Rho‐kinase after acute ischaemic attacks improves cerebral integrity and function through regulation of endothelial cell oxidative stress and reorganization of intercellular junctions.

     

Endothelin and PDGF do not stimulate peripheral blood monocyte chemotaxis, adhesion to endothelium, and superoxide production

Endothelin is a potent vasoconstrictory endothelial-derived peptide which can induce smooth muscle proliferation and therefore may be proatherogenic. Platelet-derived growth factor is also a potent mitogenic vasoconstrictory protein which is proatherogenic. We report that neither endothelin nor PDGF stimulate superoxide production, or monocyte adhesion to porcine aortic endothelial cell monolayers; additionally endothelin is not a chemoattractant factor for monocytes. If endothelin and PDGF are important in atherogenesis it is unlikely that a monocyte response to these mediators is involved.     

Threshold-Based Ordering of Sequential Actions during Drosophila Courtship

1. Download high-res image (215KB)
2. Download full-size image

     

The impact of perception and knowledge on the treatment and prevention of intestinal worms in the Manikganj district of Bangladesh

Soil transmitted helminths (STHs) affect more than one billion of the world's population and are very prevalent in regions with high poverty rates and poor sanitation. Efforts to achieve Millennium Development Goals, such as combating diseases and increasing the number of people with access to safe drinking water and proper sanitation facilities, will directly help in eliminating STHs. The Plains regions of Bangladesh has one of the highest prevalence rates of STHs, and the efforts made by the World Health Organization might not be enough to eradicate these diseases in this region before the 2015 goal. This survey was conducted in the Manikganj district of Central Bangladesh to evaluate local awareness about the transmission and prevention of STHs. The results from this survey show that although a large percentage of the respondents were knowledgeable about the spread and impact of intestinal worms, the majority of individuals still do not take the necessary steps to prevent infection. Our findings demonstrate the complexity of controlling and eliminating STHs and show that concluding efforts should incorporate additional measures for vaccine development as well as improved educational efforts that are sensitive to the region's traditions and cultures.     

Morphological variation within Acyrthosiphon pisum and in ability to transmit broad bean severe chlorosis virus

The EL and WARF biotypes of Acyrthosiphon pisum (Harris), which were originally isolated on the basis of their differential efficiency in transmitting pea enation mosaic virus (PEMV), were studied morphologically, and a key based on observed morphological differences is presented. The two biotypes also were compared as vectors of broad bean severe chlorosis virus (BBSCV). The EL biotype was more efficient than that of WARF in transmitting BBSCV; 1st-stage nymphs of EL and WARF were more efficient vectors of BBSCV than their counterpart adults.

---

Zusammenfassung Die EL und WARF Biotypen von Acyrthosiphon pisum, die ursprünglich nach ihrer Übertragungsfähigkeit für das Scharfe Adernmosaik der Erbse (PEMV) isoliert worden waren, wurden morphologisch studiert und ein Bestimmungsschlüssel ausgearbeitet. Die beiden Biotypen wurden auch als Vektoren des Schweren Chlorosevirus der Ackerbohne (BBSCV) verglichen. Der EL Biotyp war leistungsfähiger in der Übertragung von BBSCV als der WARF Typ. Erstlarven von EL und WARF waren wirksamere Vektoren von BBSCV als die entsprechenden Adulttiere.

---

---

Michigan Agricultural Experiment Station Journal Article Number 7540.     

Cortisol responses to the insulin hypoglycaemia test in children

AIM: To determine the timing of the peak cortisol response to the insulin hypoglycaemia (IH) test in children and to establish paediatric reference data. METHODS: We retrospectively reviewed all IH tests in a tertiary paediatric endocrine referral centre over a 6-year period. Inclusion criteria were age <16 years and adequate hypoglycaemia (glucose < or =2.0 mmol/l). Patients with an impaired hypothalamic-pituitary-adrenal axis or receiving glucocorticoid medication were excluded. Fifty-four subjects (35 males) met the criteria. Blood samples were collected at -30, 0, 20, 30, 60, 90, 120, and 150 min in relation to insulin bolus injection (0.15 U/kg) at 0 min. Glucose, cortisol, and growth hormone (GH) were measured in all samples. RESULTS: Peak cortisol and GH responses occurred by 90 min in all subjects. Peak cortisol was inversely correlated with age (rs -0.65, p<0.0001). The median (5th centile) peak cortisol value was 689 nmol/l (547 nmol/l) in children younger than 10 years as compared with 555 nmol/l (468 nmol/l) in those older than 10 years (p<0.0001). Peak cortisol was not related to peak GH (rs -0.20, p=0.15). CONCLUSIONS: Blood sampling in the IH test may be curtailed 90 min after injection. The peak cortisol response to IH is age related.     

Nitric oxide synthase inhibitors in experimental ischemic stroke and their effects on infarct size and cerebral blood flow: a systematic review

Nitric oxide produced by the neuronal or inducible isoform of nitric oxide synthase (nNOS, iNOS) is detrimental in acute ischemic stroke (IS), whereas that derived from the endothelial isoform is beneficial. However, experimental studies with nitric oxide synthase inhibitors have given conflicting results. Relevant studies were found from searches of EMBASE, PubMed, and reference lists; of 456 references found, 73 studies involving 2321 animals were included. Data on the effects of NOS inhibition on lesion volume (mm3, %) and cerebral blood flow (CBF; %, ml * min(-1) * g(-1)) were analyzed using the Cochrane Review Manager software. NOS inhibitors reduced total infarct volume in models of permanent (standardized mean difference (SMD) -0.56, 95% confidence interval (95% CI) -0.86, -0.26) and transient (SMD -0.99, 95% CI -1.25, -0.72) ischemia. Cortical CBF was reduced in models of permanent but not transient ischemia. When assessed by type of inhibitor, total lesion volume was reduced in permanent models by nNOS and iNOS inhibitors, but not by nonselective inhibitors. All types of NOS inhibitors reduced infarct volume in transient models. NOS inhibition may have negative effects on CBF but further studies are required. Selective nNOS and iNOS inhibitors are candidate treatments for acute IS.