Genetic heterogeneity of small ruminant lentiviruses involves immunodominant epitope of capsid antigen and affects sensitivity of single-strain-based immunoassay

The pol and gag gene fragments of small ruminant lentivirus field isolates collected in the last decade in Italy were amplified, sequenced, and analyzed. Phylogenetic analysis revealed that the majority of ovine isolates form a distinct cluster more similar to caprine lentivirus prototypes than to the visna virus prototype. These findings confirm and extend those reported by Leroux et al. (Arch. Virol., 142:1125-1137, 1997). Moreover, we observed that a variable region of Gag, included in the fragment analyzed, corresponded to one of the three major capsid antigen epitopes, which suggests that the antibody response to this epitope may be type specific. To test this hypothesis, two recombinant peptides, derived from the Icelandic prototype K1514 and this novel genotype, were expressed and used in an enzyme-linked immunosorbent assay to screen a panel of ovine and caprine sera collected from different geographical locations in Italy. Several sera reacted in a type-specific manner, indicating that in a diagnostic setting the combination of at least these two type-specific peptides is necessary to cover a wide range of infections. Additionally, these results support the hypothesis of cross-species transmission based on the phylogenetic analysis described above. This has implications for the control and eradication of small ruminant lentivirus infections.     

Differentiation of Cucumber mosaic virus isolates by hybridization to oligonucleotides in a microarray format

A system for microarrays was developed to detect and differentiate Cucumber mosaic virus (CMV) serogroups and subgroups. The coat protein genes of 14 different isolates were amplified using cy3-labelled generic but species-specific primers. These amplicons were hybridized against a set of five different serotype and subgroup specific 24-mer oligonucleotides bound to an aldehyde-coated glass slide via an aminolinker. The results of the hybridization revealed that the method allowed a clear differentiation of the 14 different CMV isolates into the serogroupes 1 and 2, and in addition was able to assign 9 out of 10 different serogroup 1 isolates correctly into subgroups 1a and 1b. This differentiation was not possible by RFLP analysis with the restriction enzyme MspI. The use of amplicons larger than 700 base pairs and their successful differentiation by hybridization to specific oligonucleotides opens avenues to highly parallel, yet sensitive assays for plant viruses.     

Bestimmung der enteralen Resorption hoher Calciumdosen mittels stabiler Isotope

Zusammenfassung Bei 8 gesunden Versuchspersonen (Durchschnittsalter 25,6 Jahre) wurde nach oraler Applikation von 500 mg und 1000 mg Calcium die Calcium-Resorption bestimmt. Hierzu wurde ein Doppelisotopenverfahren mit angereicherten stabilen Calciumisotopen verwendet, das, da im Gegensatz zu Radiotracermethoden jegliche Strahlenbelastung vermieden wird, uneingeschränkt anwendbar ist. Die oral verabreichten Calciumsalze wurden mit⁴⁸Ca, das intravenös injizierte CaCl₂ mit⁴⁶Ca markiert. Die Bestimmung der beiden Isotope in Serum- und Urinproben erfolgte mit Hilfe der Neutronenaktivierungsanalyse. Für die Resorptionsquote wurde, unabhängig von der Calcium-Dosis, ein Wert von 30% gefunden. Aus dem⁴⁶Ca-Gehalt im Serum wurde für das in 24 h ausgetauschte Körper-Calcium ein mittlerer Wert von 6,4±1,0 g Calcium oder 98,8±15,4 mg Ca/kg Körpergewicht berechnet.     

Standardized extracts from Chinese herbs induce IL-10 production in human monocyte-derived dendritic cells and alter their differentiation in vitro

BACKGROUND: The efficacy of traditional Chinese medicine (TCM) as a treatment for atopic dermatitis has been evaluated in clinical trials. Until now, the underlying mechanism of this treatment has remained completely elusive; this is particularly true of its putative effects on dendritic cells (DCs), which might play a pivotal role in the disease. OBJECTIVE: We investigated the influence of a standardized extract from 10 Chinese herbs that was successfully used in clinical trials on the generation of monocyte-derived DCs from atopic donors. METHODS: Detailed phenotypic and functional exploration of DCs generated in the presence of IL-4 and GM-CSF and treated with different concentrations of TCM or a placebo control was performed. RESULTS: TCM profoundly affected the morphology and phenotype of the developing DCs. They lost their typical dendritic morphology and decreased their expression of CD1a as well as the low-affinity IgE receptor CD23. Most importantly, TCM-exposed DCs exhibited a diminished stimulatory activity toward autologous antigen-specific and allogeneic T cells while secreting high amounts of IL-10. CONCLUSION: TCM induces immunopharmacologic alterations on DCs from atopic donors in vitro. These alterations might account, at least in part, for the therapeutic effect of this treatment in AD in vivo.     

Strategic control and medial frontal negativity: beyond errors and response conflict

Errors in timed choice tasks typically produce an error-related negativity (ERN) in the event-related potential (ERP). The error specificity of the ERN has been challenged by studies showing a correct response negativity (CRN). Forty-five participants engaged in a flanker task in which both compatibility between flankers and target and the probability of compatible flankers were manipulated. Correct responses elicited a CRN, the amplitude of which increased with the degree of mismatch between the presence of conflict and conflict probability, even on low-conflict (compatible) trials. The fronto-central N2 component was larger on high-conflict (incompatible) correct response trials. However, in contrast to some recent accounts, this N2 was largest for highly probable stimuli. These findings suggest revision to models of the effects of conflict on response-related negativity to account for strategic adjustments made in preparation for the response.     

Ranking institutional settings based on publications in community psychology journals

Two primary outlets for community psychology research, the American Journal of Community Psychology and the Journal of Community Psychology, were assessed to rank institutions based on publication frequency and scientific influence of publications over a 32‐year period. Three specific periods were assessed (1973–1983, 1984–1994, 1995–2004). Findings indicate that there were a large group of institutions that published articles during these periods. Those academic institutions that had the most published articles as well as the largest influence, based on citations by other authors, were identified. Using archival data from the community psychology literature represents one approach for identifying those settings that made substantial contributions to the development and growth of the field. © 2007 Wiley Periodicals, Inc. J Comm Psychol 35: 967–979, 2007.     

Vector competence of Mexican and Honduran mosquitoes (Diptera: Culicidae) for enzootic (IE) and epizootic (IC) strains of Venezuelan equine encephalomyelitis virus

Experimental studies evaluated the vector competence of Ochlerotatus taeniorhynchus (Wiedemann), Culex cancer Theobald, Culex pseudes (Dyar and Knab), Culex taeniopus Dyar and Knab, and a Culex (Culex) species, probably Culex quinquefasciatus Say, and Culex nigripalpus Theobald from Chiapas, Mexico, and Tocoa, Honduras, for epizootic (IC) and enzootic (IE) strains of Venezuelan equine encephalomyelitis (VEE) virus. Culex pseudes was highly susceptible to infection with both the IC and IE strains of VEE (infection rates >78%). Patterns of susceptibility to VEE were similar for Oc. taeniorhynchus collected in Mexico and Honduras. Although Oc. taeniorhynchus was highly susceptible to the epizootic IC strains (infection rates > or = 95%, n = 190), this species was less susceptible to the enzootic IE strain (infection rates < or = 35%, n = 233). The Culex (Culex) species were refractory to both subtypes of VEE, and none of 166 contained evidence of a disseminated infection. Virus-exposed Cx. pseudes that refed on susceptible hamsters readily transmitted virus, confirming that this species was an efficient vector of VEE. Although Oc. taeniorhynchus that fed on hamsters infected with the epizootic IC strain transmitted VEE efficiently, only one of six of those with a disseminated infection with the enzootic IE virus that fed on hamsters transmitted virus by bite. These data indicate that Cx. pseudes is an efficient laboratory vector of both epizootic and enzootic strains of VEE and that Oc. taeniorhynchus could be an important vector of epizootic subtypes of VEE.