Amifostine does not prevent activation of TGF beta 1 but induces smad 7 activation in megakaryocytes irradiated in vivo

Experiments were undertaken to assess the role of amifostine in the activation of latent TGFbeta1 and in the smad proteins cascade (smad 2/3, smad4, smad7), focusing on megakaryocytes, in the bone marrow irradiated in vivo. Non-irradiated megakaryocytes were negative for active TGFbeta1. Immunopositivity to active TGFbeta1 was detected in megakaryocytes 10 days after irradiation in amifostine- treated and untreated marrows. Smad 2/3 and smad 4 were strongly positive in the nucleus of megakaryocytes 10 days after irradiation. At the same time, a predominant hypocellular bone marrow with foci of hematopoiesis was observed with few megakaryocytes. An increase in the number of reticulin fibers was also seen. In amifostine-treated marrows, smad 2/3 and smad4 were not detected in the nucleus but were positive in the cytoplasm of megakaryocytes 10 days after irradiation. Coincidentally, bone marrows were cellular with megakaryocytes. Smad7 immunoexpression was detected in the cytoplasm of megakaryocytes in the non-irradiated, amifostine-treated and in the irradiated, amifostine-treated marrows. Data indicate that amifostine does not prevent latent TGFbeta1 activation in irradiated megakaryocytes. While TGFbeta1 signal transduction occurs in megakaryocytes in untreated bone marrows, it is inhibited in megakaryocytes in amifostine-treated marrows due to the induction of smad 7 activation. This is the first report showing smad 7 activation by amifostine. Our results also suggest a role for TGFbeta1 as an inhibitor of megakaryocytes in vivo. (C) 2002 Wiley-Liss, Inc.

Leptin Effects on the Regenerative Capacity of Human Periodontal Cells

Obesity is increasing throughout the globe and characterized by excess adipose tissue, which represents a complex endocrine organ. Adipose tissue secrets bioactivemolecules called adipokines, which act at endocrine, paracrine, and autocrine levels. Obesity has recently been shown to be associated with periodontitis, a disease characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium, and also with compromised periodontal healing. Although the underlying mechanisms for these associations are not clear yet, increased levels of proinflammatory adipokines, such as leptin, as found in obese individuals, might be a critical pathomechanistic link. The objective of this study was to examine the impact of leptin on the regenerative capacity of human periodontal ligament (PDL) cells and also to study the local leptin production by these cells. Leptin caused a significant downregulation of growth (TGF beta 1, and VEGFA) and transcription (RUNX2) factors as well as matrix molecules (collagen, and periostin) and inhibited SMAD signaling under regenerative conditions. Moreover, the local expression of leptin and its full-length receptor was significantly downregulated by inflammatory, microbial, and biomechanical signals. This study demonstrates that the hormone leptin negatively interferes with the regenerative capacity of PDL cells, suggesting leptin as a pathomechanistic link between obesity and compromised periodontal healing.

Expectativas sobre os efeitos do uso de álcool e padrão de beber em alunos de ensino médio

Studies have shown that adolescents begin to make use of alcoholic beverages earlier and excessively, a behavior which has several negative consequences. Thus, the present study aims at investigating whether the expectations they have for the effects of alcohol consumption are high or low and if there is a relationship between expectation and consumption pattern. AUDIT and IECPA were applied as data collection instruments. The first indentifies the pattern of alcohol use and the second investigates the expectations the subjects have in relation to the use of alcohol. The results of this study, differently than others, do not evidence the positive relationship between binge-drinking and high expectations about the use of alcohol.

Desenvolvimento cognitivo e sintomas depressivos em adolescentes que fazem uso de bebidas alcoólicas

Surveys on alcohol use show that people usually begin using this substance as adolescents. In this stage of development, it is common for some people to show depressive symptoms. The combination of alcohol and depressive symptoms may affect students’ cognitive and school development. This study aims at identifying and discussing on the relationship between alcohol use in adolescents, depression and the consequences on cognitive development. Participants were 127 students of two schools in the state of São Paulo, who answered the AUDIT, the BDI and Tests for Operatory Development. Results show that excessive alcohol use is significant, but we did not observe a relationship between alcohol use, depressive symptoms and low cognitive performance.

Effectiveness of different methods for the detection of binge drinking in dentistry students

The purpose of this study was to estimate the alcoholic beverage consumption among undergraduate students of a Dentistry Course and compare the effectiveness of screening methods for the detection of binge drinking. A total of 284 undergraduate students participated in the research. We used the full AUDIT and their reduced forms (AUDIT-3 and AUDIT-C). In addition, a ROC curve was created and its area was calculated. Of the students, 91.0% and 90.6% of the male and female genders, respectively, reported alcohol beverage consumption. Bing-drinking behavior occurred in 69.2% of the men and in 52.4% of the women. The 3 methods showed good discriminatory ability. For the women, there was a significant difference between the AUDIT-3 and AUDIT-C. Both the complete version of AUDIT and its reduced forms presented good discriminatory ability

Confiabilidade do teste de identificação de transtornos devido ao uso de álcool (AUDIT) em adolescentes

The objective of this study was to estimate the reliability of the alcohol use disorders identification test (AUDIT) applied to adolescents. Evaluations were performed with 141 students of ages ranging from 14 to 17 years (14.93±0.62). The internal consistency of the instrument was estimated by Cronbach’s alpha coefficient and its reproducibility by weighted Kappa statistics by score and by a reliability interval of 95%. The AUDIT presented excellent internal consistency (α=0.80, rinter-item=0.29). Most questions present reproducibility ranked as “good”. It is concluded that the AUDIT is a reliable instrument to survey information about alcohol use in adolescents.

Bone morphogenetic proteins: promising molecules for bone healing, bioengineering, and regenerative medicine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)