Structural insights into substrate binding of brown spider venom class II phospholipases D

Phospholipases D (PLDs), the major dermonecrotic factors from brown spider venoms, trigger a range of biological reactions both in vitro and in vivo. Despite their clinical relevance in loxoscelism, structural data is restricted to the apo-form of these enzymes, which has been instrumental in understanding the functional differences between the class I and II spider PLDs. The crystal structures of the native class II PLD from Loxosceles intermedia complexed with myo-inositol 1-phosphate and the inactive mutant H12A complexed with fatty acids indicate the existence of a strong ligand-dependent conformation change of the highly conserved aromatic residues, Tyr 223 and Trp225 indicating their roles in substrate binding. These results provided insights into the structural determinants for substrate recognition and binding by class II PLDs.

Reforma agrária e estrutura fundiária no Brasil: uma análise a partir do I Plano Nacional de Reforma Agrária

Pós-graduação em Economia - FCLAR

Parafunctional activities in brazilian children and adolescent

The etiology of TMD in children and adolescents is considered multifactorial and has been related to parafunctional habits.The objective of this research was to determine the prevalence of parafunctional habits in elementary school students of “Colégio Ipê de Assis” (Assis, SP - Brazil). In the present research was administered questionnaire (15 questions) proposed by the Center for Diagnosis and Treatment of TMD, School of Dentistry of Araçatuba, UNESP. The sample was composed of 80 elementary school students of the “Colégio Ipê de Assis” (Assis, SP - Brazil). The project was approved by the Ethics Committee in Research of the School of Dentistry of Araçatuba/ UNESP. All parents and responsible of the students received instruction about the research and preservation of identity and provide clarification if in doubt. Beyond that, they were requested to sign the informed consent in order to facilitate the participation of students. Females comprised 47,5% and males 52,5%, with age ranging from 10 to 14. The students were classified into two groups as follows: Group I-female, Group II- male. In addition, brazilian students from Groups I and II were classified according to type of oral habits presented. All students presented a parafunctional habit. Among the parafunctional habits chewing gum was the most common in both groups (72.2%, Group I and 78.5%, Group II) followed by resting chin on hand for both genders (69,5% for Group I and 67% for Group II). Tongue biting (5%) was less founded in Group II and stomach sleeping in Group I. The results obtained show the necessity of carring out preventive programs. Beside, resources of Health should increase preventive treatments.

Osmotic potentials on water uptake and germination of Guazuma ulmifolia Lam. (Sterculiaceae) seeds

Osmotic potentials on water uptake and germination of Guazuma Ulmifolia Lam. (Sterculiaceae) seeds. This work was carried out in the Germination Lab. of the Department of Botany, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo State, Brazil. The aims of this work were to determine the water uptake curve and to evaluate the germination of Guazuma ulmifolia seeds subjected to different water potentials. For the water uptake curve, seven replicates of 50 pre-scarified seeds were placed onto paper moistened with 15 mL PEG 6000 solution under the potentials 0 (control), -0.3 and -0.6 MPa at 25o C in the darkness. For the germination assay, four replicates of 50 seeds were subjected to the same above-described conditions; however, one lot of seeds was modified when there was variation in the refractometric index, whereas the remaining ones were kept in the same solutions until the end of the experiment. All three phases of water uptake were detected under 0 and -0.3 MPa; however, phase II was prolonged under -0.6 MPa and germination was not observed. For 0 and -0.3 MPa, the adopted statistical models consisted of asymptotic (phases I and II) and exponential (phase III) functions, y = a*[1 - b*exp (-c*t) + exp (-d + e*(t - t0)]. For -0.6MPa, only the asymptotic function y = a* [1 - b* exp (-c*t)] was used since there was no evidence of germination. The germination final percentage and speed index were lower under -0.3 MPa, mainly when solutions were not replaced; besides, germination was not detected under -0.6 MPa, with or without solution replacement.