The present work shows the characterization of Phaseolus acutifolius variety latifolius, on which little research has been published, and provides detailed information on the corresponding lectin. This protein was purified from a semi-domesticated line of white tepary beans from Sonora, Mexico, by precipitation of the aqueous extract with ammonium sulfate, followed by affinity chromatography on an immobilized fetuin matrix. MALDI TOF analysis of Phaseolus acutifolius agglutinin (PAA) showed that this lectin is composed of monomers with molecular weights ranging between 28 and 31 kDa. At high salt concentrations, PAA forms a dimer of 63 kDa, but at low salt concentrations, the subunits form a tetramer. Analysis of PAA on 2D-PAGE showed that there are mainly three types of subunits with isoelectric points of 4.2, 4.4, and 4.5. The partial sequence obtained by LC/MS/MS of tryptic fragments from the PAA subunits showed 90–100% identity with subunits from genus Phaseolus lectins in previous reports. The tepary bean lectin showed lower hemagglutination activity than Phaseolus vulgaris hemagglutinin (PHA-E) toward trypsinized human A and O type erythrocytes. The hemagglutination activity was inhibited by N-glycans from glycoproteins. Affinity chromatography with the immobilized PAA showed a high affinity to glycopeptides from thyroglobulin, which also has N-glycans with a high content of N-acetylglucosamine. PAA showed less mitogenic activity toward human lymphocytes than PHA-L and Con A. The cytotoxicity of PAA was determined by employing three clones of the 3T3 cell line, demonstrating variability among the clones as follows: T4 (DI50 51.5 µg/mL); J20 (DI50 275 µg/mL), and N5 (DI50 72.5 µg/mL).

New zones with risk of infection for Chagas disease were reported in San Antonio Tezoquipan, Caltimacan, and El Ahorcado in the Hidalgo State of Mexico. Antibodies to Trypanosoma cruzi were detected by enzyme-linked immunosorbent assay and indirect hemagglutination assay in human serum samples. Study subjects were also given an electrocardiogram. Trypanosoma cruzi was isolated from triatomines collected and its virulence was determined in BALB/c mice. Seropositive persons were found in the three regions studied and seroprevalence of T. cruzi ranged between 3.25% and 5.13%. Six of eight seropositive persons had cardiac alterations. The species of triatomines detected were Triatoma barberi, Triatoma mexicana, and Triatoma dimidiata, and at least one of each species was infected with T. cruzi. Entomologic indexes from the zones were determined, and El Ahorcado showed the greatest risk of infection. In this region, we found more virulent isolates of T. cruzi in Triatoma barberi, and the highest human seroprevalence for T. cruzi.

Circadian rhythm disruption is one of the earliest biomarkers of Alzheimer’s disease (AD), and there exists a bidirectional relationship by which dysfunctions in the circadian clock drive AD pathology and AD pathology drives circadian dysfunction. Casein kinase 1 (CK1) isoforms ε and δ, key circadian regulators, are significantly upregulated in AD and may contribute to AD pathogenesis. In the current studies, we have examined how inhibition of CK1ε/δ with PF-670462 (at 10 mg/kg, δ isoform selective, or 30 mg/kg, δ and ε selective) impacts regional Aβ and circadian gene expression in 10–13 month old APP-PS1 mice and nontransgenic controls. We have also assessed circadian, cognitive, and affective behavioral correlates of these neural changes. At baseline, APP-PS1 mice showed a short period, as well as impaired cognitive performance in both prefrontal cortex and hippocampus-dependent tasks. Both doses of PF-670462 lengthened the period and improved affect, whereas only the higher dose improved cognition. Further, PF-670462 treatment produced a dose-dependent reduction in amyloid burden – overall Aβ signal decreased in all three areas; in the prefrontal cortex and hippocampus, PF-670462 also reduced plaque size. Together, these findings support chronotherapy as a potential tool to improve behavior in AD.

-In order to determine the risk of transmission of Trypanosoma cruzi by triatomines in Metztitlan municipality, Hidalgo State, Mexico, entomological indexes were calculated and the characteristics of dwellings were described. A transversal, retrospective, descriptive, and observational study was performed by means of an intentional not probabilistic and expertise sampling from January to December of 2005 in 10 localities in which presence of triatomines were investigated either intra or peridomestic environmental in 699 houses. Building material and presence of infected triatomines with T. cruzi were registered to determine entomologic indexes. The triatomine species collected were: Triatoma barberi (Usinger) and T. mexicana (Herrich-Schaeffer) (Hemiptera: Reduviidae). The results indicated that natural infection index varied from 7.7% to 50%; colonization index reached 80%; infestation index varied from 7.7% to 25%; dispersion index was 70%. Stone-walled houses were more infested. We can conclude that it is necessary to establish T. cruzi transmission control measures against triatomines in localities from Metztitlan, primarily in stone-walled houses where T. barberi occurs, as it was the most important vector species in the transmission of T. cruzi in this municipality. KEY WORDS: Triatoma barberi, Triatoma mexicana, Chagas disease, vector, epidemiologyLa enfermedad de Chagas, cuyo agente causal es el protozoario hemoflagelado Trypanosoma cruzi, es un importante problema de salud pública en países latinoamericanos en donde se ha estimado que aproximadamente el 25% de los habitantes están en riesgo de infección lo cual es alrededor de 120 millones (Guzmán 2001). En México se realizó la Encuesta Nacional Seroepidemiológica (ENSE) demostrando presencia de personas seropositivas a T. cruzi en todos los estados de la República con prevalencias que varían del 0,1% al 5% (Velasco et al 1992).La transmisión de T. cruzi al humano ocurre mediante varios mecanismos, el más frecuente es mediante las deyecciones de insectos redúvidos hematófagos denominados triatóminos, quienes defecan sobre un individuo durante el momento en que le están picando (Brener 1973, García et al 2000. Por tanto, los habitantes que viven en las zonas donde se detecta la presencia de triatóminos quedan en riesgo de adquirir la enfermedad de Chagas. Independientemente de las especies que se encuentren, todas las especies son transmisoras desde sus etapas ninfales hasta las adultas. Sin embargo, un dato interesante es que la capacidad transmisora del redúvido, además de su comportamiento, puede ser distinta para cada especie (Alejandre et al