Mediation - the Malaysian Dental Association experience

Objectives: To study the success and failures of the mediation process of complaints from 2004-2007 by the Complaints Bureau Steering Committee and the Public Complaints Bureau Committee of the Malaysian Dental Association (MDA). Methods: Retrospective analysis of complaints from the records at the MDA. Results: There were 41 cases during the three years, most involved surgical procedures (9), endodontics (9), miscellaneous (8), orthodontics (6), restorative problems (6) and prosthetics (2). Chinese patients made the most complaints (67) followed by Malay patients (23), foreigners (7) and Indians (3). 69 of the cases where against dentists working in the KIang Valley, 14 in Johore and the rest in various part of the country. 69 of the cases were successfully mediated, 10 unresolved and the 21 are in various stages of mediation. Conclusion: It is heartening to report that the MDA has successfully mediated in a sizeable number of the complaints which are increasing yearly

Quantification of the Dental Morphology of Orangutans

Orangutans are believed to have close biological affinities to humans. Teeth being the hardest tissue provide useful information on primate evolution. Furthermore, knowledge of the pulp chamber and root canal morphology is important for dental treatment. A female Bornean orangutan and a Sumatran male orangutan skull were available for this study. Both of their dentitions, comprising 50 teeth, were scanned employing the cone-beam computed tomography for both metrical and nonmetrical analyses. Measurements included tooth and crown length, root length, enamel covered crown height, root canal length (posterior teeth), length of pulpal space (anterior teeth), and root canal width. Nonmetrical parameters included number of canals per root, number of foramina in each root, and root canal morphology according to Vertucci’s classification. It was found that the enamel covered crown height was the longest in the upper central incisors although the canine was the longest amongst the anterior teeth. Both the upper premolars were three-rooted while the lower second premolar of the Sumatran orangutan was two-rooted, with two foramina. The mandibular lateral incisors of the Bornean orangutan were longer than the central incisors, a feature similar to humans. In addition, secondary dentine deposition was noticed, a feature consistent with aged humans

Unexpected Role for Helicobacter pylori DNA Polymerase I As a Source of Genetic Variability

Helicobacter pylori, a human pathogen infecting about half of the world population, is characterised by its large intraspecies variability. Its genome plasticity has been invoked as the basis for its high adaptation capacity. Consistent with its small genome, H. pylori possesses only two bona fide DNA polymerases, Pol I and the replicative Pol III, lacking homologues of translesion synthesis DNA polymerases. Bacterial DNA polymerases I are implicated both in normal DNA replication and in DNA repair. We report that H. pylori DNA Pol I 5′- 3′ exonuclease domain is essential for viability, probably through its involvement in DNA replication. We show here that, despite the fact that it also plays crucial roles in DNA repair, Pol I contributes to genomic instability. Indeed, strains defective in the DNA polymerase activity of the protein, although sensitive to genotoxic agents, display reduced mutation frequencies. Conversely, overexpression of Pol I leads to a hypermutator phenotype. Although the purified protein displays an intrinsic fidelity during replication of undamaged DNA, it lacks a proofreading activity, allowing it to efficiently elongate mismatched primers and perform mutagenic translesion synthesis. In agreement with this finding, we show that the spontaneous mutator phenotype of a strain deficient in the removal of oxidised pyrimidines from the genome is in part dependent on the presence of an active DNA Pol I. This study provides evidence for an unexpected role of DNA polymerase I in generating genomic plasticity

Противоопухолевое действие кураксина CBL0137 на моделях аденокарциномы толстой кишки

Curaxins represent low molecular weight carbazole derivatives, which simultaneously activate p53-dependent apoptosis and inhibit NF-kBdependent signal transduction pathways. Antitumor activity of curaxin CBL0137 was demonstrated in vivo on the model of solid transplantable mouse colon adenocarcinoma Akatol. Significant tumor growth inhibition caused by CBL0137 treatment was observed. On the 37th day after tumor transplantation for CBL0137 oral doses 5, 10, 15 and 20 mg/kg the tumor growth inhibition indexes were 53, 50, 56 and 74 %, respectively. CBL0137 treatment extended life span of mice in all study groups receiving this test article. Maximum lifespan increase (81,7 %) was observed in the group of mice treated with 20 mg/kg dose of CBL0137. The cytotoxicity of CBL0137 was assessed on human colon cancer cells in vitro. We demonstrated that CBL0137 inhibits the expression COX2, which in its turn is known to exhibit antiapoptotic, pro-angiogenic and pro- metastatic properties. Thus, we demonstrated antitumor effect of CBL0137 against colon cancer in vitro and in vivo.Кураксины представляют собой низкомолекулярные карбазольные производные, обладающие афинностью к ДНК, способные одновременно активировать р53-зависимый апоптоз и ингибировать NF-kB-зависимый сигнальный путь. На модели перевиваемой аденокарциномы толстой кишки (Aкатол) на мышах линии BALB/c продемонстрировано противоопухолевое действие кураксина CBL0137. Наблюдалось значительное тормозящее действие CBL0137 на рост данной аллографтной опухоли: на 37-е сутки после перевивки опухоли при пероральном введении препарата в дозах 5, 10, 15 и 20 мг/кг в день торможение роста опухоли составило 53, 50, 56 и 74 % соответственно. Значимое увеличение продолжительности жизни наблюдалось во всех группах животных, получавших CBL0137. Максимальный эффект (81,7 %) был получен при введении препарата в дозе 20 мг/кг в день. В экспериментах in vitro при обработке клеток аденокарциномы толстой кишки человека HTC116 наблюдался значительный цитотоксический эффект. CBL0137 проявил способность ингибировать экспрессию гена COX2, обладающего антиапоптотическим действиеми способностью стимулировать неоангиогенез и метастазирование. Таким образом, в системах in vivo и in vitro продемонстрировано противоопухолевое действие CBL0137 в отношении аденокарциномы толстой кишки