Proteomic profile of human gingival crevicular fluid reveals specific biological and molecular processes during clinical progression of periodontitis

BACKGROUND AND OBJECTIVE

There is no clear understanding of molecular events occurring in the periodontal microenvironment during clinical disease progression. Our aim was to explore qualitative and quantitative differences in gingival crevicular fluid (GCF) protein profiles from patients diagnosed with periodontitis between non-progressive and progressive periodontal sites.

METHODS

Five systemically healthy patients diagnosed with periodontitis were monitored weekly in their progression of the disease and GCF samples from 10 candidate sites were obtained. Two groups of five sites, matched from an equal number of teeth, were selected from the five patients: Progression (PG) and Non-Progression (NP). Global protein identification was performed with high-throughput proteomic approaches and label-free analysis determined their relative abundances. Proteins were identified by Proteome Discoverer v2.4 and searched against human SwissProt protein databases. Enrichment bioinformatic analyses were performed in STRING-DB and ShinyGO environment.

RESULTS

1504 and 1500 proteins were identified in NP and PG respectively. Forty-eight proteins were exclusively identified in PG, while 52 were identified in NP. Moreover, 35 proteins were more abundant in PG and 29 proteins in NP (twofold change, p < .05). The NP group was mainly represented by proteins from "response to biotic stimuli and other organisms," "processes of cell death regulation," "peptidase regulation," "protein ubiquitination," and "ribosomal activity" GO categories. The most represented GO categories of the PG group were "assembly of multiprotein complexes," "catabolic processes," "lipid metabolism," and "binding to hemoglobin and haptoglobin."

CONCLUSIONS

There are quantitative and qualitative differences in the proteome of GCF from periodontal sites according to the status of clinical progression of periodontitis. Progressive periodontitis sites are characterized by a protein profile associated with catabolic processes, immune response, and response to cellular stress, while stable periodontitis sites show a protein profile mainly related to wound repair and healing processes, cell death regulation, and chaperone-mediated autophagy. Understanding the etiopathogenic role of these profiles in progressive periodontitis may help to develop new diagnostic and therapeutic approaches.

Factors influencing professionalism during dental training at the University of Chile: perception of students and patients

BACKGROUND

The University should be considered a favourable space and agent for the training and transmission of values and attitudes related to professionalism, such as responsibility, teamwork and ethical commitment. In addition, dentistry is a profession with a deep social sense that seeks to solve the oral health problems of the population to improve the quality of life. In this context, our aim was to explore the perception of students and patients about the contribution of the curriculum to the development of professionalism and to identify the factors that strengthen and weaken this perception.

METHODS

A qualitative approach was carried out through focus groups and semi-structured interviews with students from the 4th, 5th and 6th year of training and patients treated at the Dental Clinic of our Faculty.

RESULTS

In the opinion of patients and students, the factors that debilitate the training in professionalism are associated with weakened professional values/behaviours in the training, the lack of teacher training of the professors and factors of educational environment. On the contrary, factors strengthening the professionalism are mainly related to hallmark values/ professional behaviours trained in the institution and to the good evaluation by patients. The respondents also perceive the implementation of a new curriculum as a positive factor for the training in professionalism.

CONCLUSION

The patients and students interviewed believe that the main strength for the training in professionalism in the institution is the development of adaptability for the future professionals to any social context, especially to a vulnerable one, the ability to solve the problems they face and the responsibility towards the patients and their treatment.

Haptoglobin Induces a Specific Proteomic Profile and a Mature-Associated Phenotype on Primary Human Monocyte-Derived Dendritic Cells

Damage-associated molecular patterns (DAMPs) play a critical role in dendritic cells (DCs) ability to trigger a specific and efficient adaptive immune response for different physiological and pathological scenarios. We have previously identified constitutive DAMPs (HMGB1 and Calreticulin) as well as new putative inducible DAMPs such as Haptoglobin (HP), from a therapeutically used heat shock-conditioned melanoma cell lysate (called TRIMEL). Remarkably, HP was shown to be the most abundant protein in the proteomic profile of heat shock-conditioned TRIMEL samples. However, its relative contribution to the observed DCs phenotype has not been fully elucidated. Human DCs were generated from monocytes isolated from PBMC of melanoma patients and healthy donors. DC lineage was induced with rhIL-4 and rhGM-CSF. After additional stimulation with HP, the proteome of these HP-stimulated cells was characterized. In addition, DCs were phenotypically characterized by flow cytometry for canonical maturation markers and cytokine production. Finally, in vitro transmigration capacity was assessed using Transwell plates. Our results showed that the stimulation with HP was associated with the presence of exclusive and higher relative abundance of specific immune-; energy production-; lipid biosynthesis-; and DAMPs-related proteins. Importantly, HP stimulation enhanced the expression of specific DC maturation markers and pro-inflammatory and Th1-associated cytokines, and an in vitro transmigration of primary human DCs. Taken together, these data suggest that HP can be considered as a new inducible DAMP with an important role in in vitro DC activation for cancer immunotherapy.

Values related to professionalism in dental education at the University of Chile: Student and faculty perceptions

OBJECTIVE

It is recognised that professionalism should play a central role in dental education. However, its implementation into the curricula of dental schools is still limited. Our objective was to identify the main values related to professionalism based on the perceptions of students and faculty members from the Faculty of Dentistry, University of Chile.

METHODS

A Dental Values Survey was validated and culturally adapted in order to guarantee the greatest possible internal validity. The adapted survey was administered to students and faculty members (416 and 225, respectively). The final survey contained 64 items rated on a Likert scale of 1-5. Each item was categorised according to five dimensions: Altruism, Consciousness, Personal Satisfaction, Quality of Life and Professional Status. The values were compared between faculty and students and among students at different courses. A values scale was constructed by selecting the five items with the highest average score for each dimension.

RESULTS

Survey respondents composed 34.32% of the universe, of which 50.46% were faculty and 49.54% were students. Values associated with Altruism, Consciousness and Professional Status, were the highest rated by students and faculty. Values associated with Personal Satisfaction and Quality of Life received the lowest scores for both groups.

CONCLUSIONS

To provide the best possible attention to patients (Consciousness), and that patients have access to affordable dental care (Altruism), are the values at the top of our scale. On the other hand, to maintain financial stability and to be well paid (Quality of Life) were the less considered.

An "XL" endodontics intervention for dental students required to repeat the course: changing frustration to improved grades and attitudes

Given the psychological and financial costs involved with failing a clinical course, especially in developing countries, an alternative educational method was tested with students who had to repeat the year-long endodontic course at the University of Chile Faculty of Dentistry. The objectives of the intervention were to deepen theoretical knowledge and practical experiences, as well as to reinforce personal confidence in an endodontic clinical setting for students who failed the regular endodontic course. The aim of this study was to evaluate the success of this new model of educational intervention. In the study, 28 students who had failed the endodontic course repeated it with an alternative teaching method. The students attended patients immediately following practical competence exams, and they had access to simulated models that used rotary instruments and access cavities and had emergency care practice. Feedback sessions were held after each clinical session. Final grades were compared with those of other students who repeated the course without the intervention from 2007 to 2009. A survey was administered to understand the causes of initial failure and their opinions of the intervention. Students who participated in the alternative course did significantly better than their counterparts from previous years who did not receive the intervention (5.7±0.3 vs. 5.4±0.2; p<0.05). Their overall perception of the intervention was positive, and the main cause for previous course failure was personal insecurity and slow clinical care performance (54.2% of the students). The intervention course not only improved grades but also generated interest in endodontics, a contrasting perspective to the frustration students usually express after repeating the course. The results of this study support the introduction of similar interventions in endodontics and perhaps other courses.

Development of ethical practices and social responsibility in dental education at the university of Chile: student and faculty perceptions

BACKGROUND

The authors argue that dental curricula in Latin America are noted for providing highly technical and individualistic training that may fail to address society's problems or instil in the dentist the idea that he/she has a social responsibility to contribute to his/her community.

OBJECTIVES

This study's main objectives were to determine whether the curriculum and the faculty teaching practices of the School of Dentistry at the University of Chile contribute to its students' commitment to ethical and social responsibility.

METHODS

This was a qualitative study that investigated the perceptions of sixteen subjects (eight students and eight faculty members). Data were collected in thorough deep interviews. The interview process model conceptualised and organised the information into sets of dimensions and categories. The dimensions studied were ethical commitment and social responsibility. The categories assessed within ethical commitment were honesty, tolerance, responsibility and respect. In the social responsibility dimension, the categories were solidarity, teamwork and concern for and communication with the patient. Analysis of the textual data was performed using a method of content analysis based upon constructed qualitative matrices.

RESULTS

Our results show that students and scholars alike realise that ethical commitment and a sense of social responsibility are not promoted in the curriculum. They do, however, recognise the importance of these qualities in dental practitioners.

CONCLUSIONS

These results indicate that the current curriculum and teaching practices used in our School of Dentistry need to be reviewed and that programmes promoting professionals' commitment to their role in society need to be implemented.

Diverse and participative learning methodologies: a remedial teaching intervention for low marks dental students in Chile

The purpose of this educational intervention was to diagnose the learning style of a group of low marks (i.e., grades) dental students in Chile and improve their academic achievement by means of remedial teaching. The intervention group was composed of ten students in endodontics and eleven in pedodontics with low marks. These two groups were mutually exclusive. The Kolb test of learning styles was applied to the low mark students group and to the rest of the class (n=72). Diverse methodologies were applied to the low marks students, such as seminars, case-based learning and problem-based learning, directed study, plenary discussions and debate, integration and questions, and web-based learning in an effort to cover all learning styles. Students' perceptions of the educational intervention were assessed by means of a questionnaire. The learning styles of the low marks group were mainly divergent (52.4 percent) and convergent (19 percent). Accommodators and assimilators were 14.3 percent each. The rest of the class showed a very distinct frequencies distribution: divergent 18 percent, convergent 20 percent, accommodators 28 percent, and assimilators 34 percent. After the educational intervention, the mean of the scores obtained by the intervention group in formal evaluations was higher than the average scores obtained before the intervention for both courses. Students' perceptions of the activities were that they were effective for their learning process (76 percent) and that the teaching methodologies were useful mainly to clarify concepts and contents from both courses (82 percent). We can conclude that the use of diverse and participative teaching methodologies in a remedial teaching intervention, to cover all the different learning styles of the students, contributes to improve their marks in formal evaluations.