Conditioned media of pancreatic cancer cells and pancreatic stellate cells induce myeloid-derived suppressor cells differentiation and lymphocytes suppression.

As pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) are the two major cell types that comprise the immunosuppressive tumor microenvironment of pancreatic cancer, we aimed to investigate the role of conditioned medium derived from PCCs and PSCs co-culture on the viability of lymphocytes. The conditioned medium (CM) collected from PCCs and/or PSCs was used to treat peripheral blood mononuclear cells (PBMCs) to determine CM ability in reducing lymphocytes population. A proteomic analysis has been done on the CM to investigate the differentially expressed protein (DEP) expressed by two PCC lines established from different stages of tumor. Subsequently, we investigated if the reduction of lymphocytes was directly caused by CM or indirectly via CM-induced MDSCs. This was achieved by isolating lymphocyte subtypes and treating them with CM and CM-induced MDSCs. Both PCCs and PSCs were important in suppressing lymphocytes, and the PCCs derived from a metastatic tumor appeared to have a stronger suppressive effect than the PCCs derived from a primary tumor. According to the proteomic profiles of CM, 416 secreted proteins were detected, and 13 DEPs were identified between PANC10.05 and SW1990. However, CM was found unable to reduce lymphocytes viability through a direct pathway. In contrast, CM that contains proteins secreted by PCC and/or PSC appear immunogenic as they increase the viability of lymphocytes subtypes. Lymphocyte subtype treated with CM-induced MDSCs showed reduced viability in T helper 1 (Th1), T helper 2 (Th2), and T regulatory (Treg) cells, but not in CD8+ T cells, and B cells. As a conclusion, the interplay between PCCs and PSCs is important as their co-culture displays a different trend in lymphocytes suppression, hence, their co-culture should be included in future studies to better mimic the tumor microenvironment.

Quality assurance in education: perception of undergraduate health professions students in a Malaysian university.

PURPOSE: Direct student involvement in quality processes in education has been suggested to encourage shared responsibilities among faculty and students. The objectives of this study were to explore undergraduate health professions students' understanding of quality assurance (QA) in education, and identify the challenges and enablers for student involvement in an Asian context. METHODS: Twenty semi-structured interviews were conducted among medical, dentistry, and pharmacy students in a Malaysian University. The interviews were audio-recorded, transcribed verbatim, and thematically analyzed to understand the students' perspectives of QA in education. RESULTS: The participants recognized the importance of QA towards ensuring the quality of their training, which will consequently impact their work readiness, employability, and quality of healthcare services. Academic governance, curriculum structure, content and delivery, faculty and student quality, teaching facilities, and learning resources were indicated as the QA areas. The challenges for students' involvement included students' attitude, maturity, and cultural barrier. To enhance their buy-in, clear objectives and impact, efficient QA mechanism, and recognition of students' contribution had been suggested. CONCLUSION: The findings of this study support student-faculty partnership in QA processes and decision making.

Characterization of structural stability of palm oil esters-based nanocosmeceuticals loaded with tocotrienol.

BACKGROUND: Palm oil esters (POEs) are esters derived from palm oil and oleyl alcohol have great potential in the cosmetic and pharmaceutical industries due to the excellent wetting behavior of the esters without the oily feel. The role of oil-in-water nanoemulsions loaded with tocotrienol sedimentation behavior was studied. LUMiFuge® 116 particle separation analyzer was used to investigate the sedimentation behavior of POEs/tocotrienol/xanthan gum nanoemulsion system during centrifugation. Analyzing the sedimentation kinetics of dispersions in a centrifugal field also yields information about the rheological behavior and structural stability. METHODS: Experiments were performed in an analytical centrifuge at 11 × g to 1140 × g (LUMiFuge® 116 particle separation analyzer). The samples in the LUMiFuge® 116 particle separation analyzer were centrifuged at 3000 rpm for 15 h at 32°C. Sample volume of 2 cm3 was used. The rheological property of nanoemulsions was investigated using oscillatory measurements test. A rotational/oscillatory viscometer, Kinexus Rheometer (Malvern Instrument, UK) was used. All measurements were performed with a stainless steel cone-plate sensor at 25.0 ± 0.1°C with 4°/40 mm. RESULTS: The stable nanoemulsions showed sedimentation rates at earth gravity of 5.2, 3.0 and 2.6 mm/month for 10%, 20% and 30% (w/w) oil phase, respectively. Rheological behavior is an important target during the design of palm oil esters-based nanocosmeceuticals. The presence of a network structure was indicated by measurements which showed G' to be greater than G". This result implied the predominant elastic response and high storage stability of the nanoemulsion. It was also observed that the increase in oil phase concentration led to the profile which strongly indicated that the solid like elastic property; where the values of phase angle, δ of these nanoemulsions was lower than 45°. CONCLUSIONS: The nanoemulsions with higher oil phase concentration (30% (w/w)) showed greater elasticity which implied strong dynamic rigidity of the nanoemulsion. It was the most stable with longest shelf-life.