Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae) extracts inhibit the growth of the breast cancer cell lines MDA-MB-231 and MCF-7, but not the brain tumour cell line U251 in vitro.

Zanthoxylum usambarense (Engl.) Kokwaro has traditionally been used for the treatment of malaria, upper respiratory tract infections, cough, rheumatism, tooth decay and sore gums in Kenya and other African countries. Dried ground parts of Z. usambarense were extracted by maceration using methanol (MeOH) at room temperature, extract was dried and reconstituted in 70% aq. MeOH and partitioned against n-hexane and chloroform (CHCl3 ) to obtain MeOH, n-hexane and CHCl3 extracts. All extracts were assessed for cytotoxicity against two breast cancer cell lines, MDA-MB-231 and MCF-7, and the brain tumour cell line U251 by the MTT assay. The free-radical scavenging activity of the extracts was also determined by the 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. In the DPPH assay, the MeOH extract was found to be the most active free-radical scavenger with a RC50 value of 41.1 × 10(-3) mg/mL. It also displayed significant cytotoxicity against the MCF-7 cell line (IC50 42.9 µg/mL) and appeared to have induced cell death through apoptosis. None of the test extracts showed any activity against the U251 cell line at test concentrations. The present findings demonstrated that Z. usambarense could be a potential source for new cytotoxic compounds for possible anticancer drug development.

Computer-guided implant rehabilitation of an edentulous patient.

Computer-guided implant treatment is one of the popular options in the rehabilitation of dentitions in the edentulous situation. Patients should benefit not only from the advent of precise implant installation, but also the possibility of restoration of function and aesthetics immediately after the treatment. This poster presentation illustrated, from the view of the prosthodontist, the procedures and precautions involved using a clinical case as an example.

Facilitating internalization: the self-determination theory perspective.

Self-determination theory (Deci & Ryan, 1985) posits that (a) people are inherently motivated to internalize the regulation of uninteresting though important activities; (b) there are two different processes through which such internalization can occur, resulting in qualitatively different styles of self-regulation; and (c) the social context influences which internalization process and regulatory style occur. The two types of internalization are introjection, which entails taking in a value or regulatory process but not accepting it as one's own, and integration, through which the regulation is assimilated with one's core sense of self. Introjection results in internally controlling regulation, whereas integration results in self-determination. An experiment supported our hypothesis that three facilitating contextual factors--namely, providing a meaningful rationale, acknowledging the behaver's feelings, and conveying choice--promote internalization, as evidenced by the subsequent self-regulation of behavior. This experiment also supported our expectation that when the social context supports self-determination, integration tends to occur, whereas when the context does not support self-determination, introjection tends to occur.

What motivates children's behavior and emotion? Joint effects of perceived control and autonomy in the academic domain.

This study examined the contribution of perceived control and autonomy to children's self-reported behavior and emotion in the classroom (N = 246 children ages 8-10 years). Multiple regression analyses revealed unique effects of autonomy over and above the strong effects of perceived control. In addition, both sets of perceptions (and their interaction) were found to distinguish children who were active but emotionally disaffected from those who were active and emotionally positive. Specific predictions were also tested regarding the effects of (a) control attributions to 5 causes and (b) 4 reasons for task involvement that differed in degree of autonomy on children's active (vs. passive) behavior and 4 kinds of emotions: boredom, distress, anger, and positive emotions. Implications of the findings for theories of children's motivation are discussed, as well as for diagnostic strategies to identify children at risk for motivational problems