Dental students' perceptions on the contribution and impact role of a clinical teacher.

OBJECTIVES: This study was conducted in University of Malaya to evaluate student perceptions on the contribution and role of an effective clinical teacher based on the cognitive apprenticeship model in clinical practice. METHODS: Self-administered questionnaires were distributed to 233 undergraduate dental students involved with clinical teaching. This modified and validated questionnaire focusing on students' learning environment was used in order to gain relevant information related to dental clinical teaching. Six domains with different criteria applicable to clinical teaching in dentistry were selected consisting of modelling (four criteria), coaching (four criteria), scaffolding (four criteria), articulation (four criteria), reflection (two criteria) and general learning environment (six criteria). Data analyses were performed using IBM SPSS Statistics 20. RESULTS: Majority of the students expressed positive perceptions on their clinical learning experience towards the clinical teachers in the Faculty of Dentistry, University of Malaya, in all criteria of the domains. Few negative feedbacks concerning the general learning environment were reported. CONCLUSION: Further improvement in the delivery of clinical teaching preferably by using wide variety of teaching-learning activities can be taken into account through students' feedback on their learning experience.

Genotype CC of rs12979860 is providing protection against infection rather than assisting in treatment response for HCV genotype 3a infection.

Recent discovery of single-nucleotide polymorphisms located in the upstream region of interleukin-28B (IL28B) has shown association with interferon (IFN) treatment response especially in hepatitis C virus (HCV) genotype 1-infected patients. Pakistan, being the country with second highest prevalence of HCV with predominantly 3a genotype infection, bears a significant disease burden. The present study was conducted to evaluate the effect of rs12979860 genotypes on treatment response in HCV-3a-infected patients. This study shows that the CC genotype is providing protection against infection to HCV. But once infected, the CC genotype patients show viral persistence following IFN therapy. The TT genotype is assisting the 3a patients in viral clearance after IFN treatment. To our knowledge, this is the first study showing rs12979860 genotype association with IFN response in Pakistani HCV-3a-infected patients.

pH dependent poly[2-(methacryloyloxyethyl)trimetylammonium chloride-co-methacrylic acid]hydrogels for enhanced targeted delivery of 5-fluorouracil in colon cancer cells.

Stimuli responsive hydrogels have shown enormous potential as a carrier for targeted drug delivery. In this study we have developed novel pH responsive hydrogels for the delivery of 5-fluorouracil (5-FU) in order to alleviate its antitumor activity while reducing its toxicity. We used 2-(methacryloyloxyethyl) trimetylammonium chloride a positively charged monomer and methacrylic acid for fabricating the pH responsive hydrogels. The released 5-FU from all except hydrogel (GEL-5) remained biologically active against human colon cancer cell lines [HT29 (IC50 = 110-190 µg ml(-1)) and HCT116 (IC50 = 210-390 µg ml(-1))] but not human skin fibroblast cells [BJ (CRL2522); IC50 ≥ 1000 µg ml(-1)]. This implies that the copolymer hydrogels (1-4) were able to release 5-FU effectively to colon cancer cells but not normal human skin fibroblast cells. This is probably due to the shorter doubling time that results in reduced pH in colon cancer cells when compared to fibroblast cells. These pH sensitive hydrogels showed well defined cell apoptosis in HCT116 cells through series of events such as chromatin condensation, membrane blebbing, and formation of apoptotic bodies. No cell killing was observed in the case of blank hydrogels. The results showed the potential of these stimuli responsive polymer hydrogels as a carrier for colon cancer delivery.

Pairing as an instructional strategy to promote soft skills amongst clinical dental students.

Training dentists today is challenging as they are expected to provide a wide range of dental care. In the provision of good dental care, soft skills are equally important as clinical skills. Therefore in dental education the development of soft skills are of prime concern. This study sought to identify the development of soft skills when dental students are paired in their clinical training. In this perception study, four open-ended items were used to elicit students' feedback on the appropriateness of using clinical pairing as an instructional strategy to promote soft skills. The most frequently cited soft skills were teamwork (70%) and communication (25%) skills. However, both negative and positive behaviours were reported. As for critical thinking and problem solving skills, more positive behaviours were reported for abilities such as to explain, analyze, find ideas and alternative solutions, and make decisions. Leadership among peers was not evident as leading without legitimate authority could be a hindrance to its development. If clinical pairing is to be used as an effective instructional strategy to promote soft skills amongst students, clear guidelines need to be developed to prepare students to work in a dental team and the use of appropriate assessment tools can facilitate the development of these soft skills.

Prevalence and Severity of Social Anxiety Symptoms and Their Relationship With Body Dysmorphic Symptoms.

Background Social anxiety disorder (SAD) is a subtype of anxiety characterized by avoidance, fear, and physical symptoms such as dry mouth, sweating, palpitations, and blushing. SAD is one of the most common mental disorders. Body dysmorphic disorder (BDD) is a mental disorder marked by a distressing or impairing preoccupation with imagined or minor flaws in one's physical appearance. Both disorders share similar symptoms. No satisfactory data have been provided about the prevalence of social anxiety symptoms in our region. In our study, we measured the prevalence and severity of SAD symptoms among adults in Riyadh City, as well as the sociodemographic factors associated with it. Additionally, the correlation between SAD and BDD was assessed. Methods Our study is quantitative, observational, and cross-sectional. It was conducted by administering a translated Arabic version of the Severity Measure for Social Anxiety Disorder scale and BDD scales in five locations in Riyadh, which include two general hospitals and three shopping malls. Data were analyzed using the SPSS version 22 (IBM Corp., Armonk, NY, USA). Descriptive statistical data are presented through mean values, standard deviations, and percentages. Results A total of 752 responses were received, of which 509 (68.32%) were from females with a mean age of 30.12 years. The majority of the sample had a low to middle family income, with 64% earning less than $2555 monthly. The sample possessed a good educational level; 63% had a bachelor's degree or higher. Our study also shows that 233 subjects (30.98%) had scores indicating a moderate to severe form of SAD. Among these participants, 86 (36.9%) had scores indicating a moderate to severe form of BDD. There was a significant positive correlation between SAD and BDD (r = 0.496). Conclusion The prevalence of SAD was 30.98%, which is higher compared to Western countries. Low income, education, and female gender have roles in the disease condition. Moreover, there was a linear relationship between SAD and BDD.

Membrane technology for pesticide removal from aquatic environment: Status quo and way forward.

The noxious side effects of pesticides on human health and environment have prompted the search of effective and reliable treatment techniques for pesticide removal. The removal of pesticides can be accomplished through physical, chemical and biologicals. Physical approaches such as filtration and adsorption are prevailing pesticide removal strategies on account of their effectiveness and ease of operation. Membrane-based filtration technology has been recognized as a promising water and wastewater treatment approach that can be used for a wide range of organic micropollutants including pesticides. Nanofiltration (NF), reverse osmosis (RO) and forward osmosis (FO) have been increasingly explored for pesticide removal from aquatic environment owing to their versatility and high treatment efficiencies. This review looks into the remedial strategies of pesticides from aqueous environment using membrane-based processes. The potentials and applications of three prevailing membrane processes, namely NF, RO and FO for the treatment of pesticide-containing wastewater are discussed in terms of the development of advanced membranes, separation mechanisms and system design. The challenges in regards to the practical implementation of membrane-based processes for pesticide remediation are identified. The corresponding research directions and way forward are highlighted. An in depth understanding of the pesticide nature, water chemistry and the pesticide-membrane interactions is the key to achieving high pesticide removal efficiency. The integration of membrane technology and conventional removal technologies represents a new dimension and the future direction for the treatment of wastewater containing recalcitrant pesticides.

Head and neck cancer: possible causes for delay in diagnosis and treatment.

OBJECTIVE: To explore the possible causes for delay in diagnosis and treatment of head and neck cancer at Sarawak General Hospital (SGH). STUDY DESIGN: This is a prospective study of time interval between onset of symptom, first medical consultation, first specialist clinic consultation, diagnosis and treatment of head and neck cancer in otorhinolaryngology head and neck (ORL-HNS) and dental clinics at Sarawak General Hospital. Forty-two consecutive cases diagnosed to have cancer between July to December 2006 were studied. RESULTS: Mean interval between onset of symptom and medical consultation was 3.8 months, mean interval between first medical consultation to ORL-HNS or dental clinic referral was 8.4 weeks, mean duration between first ORL-HNS or dental specialist consultation to histopathological diagnosis was 18.8 days while duration between diagnosis to definite treatment was 26.9 days. CONCLUSION: Most cases were diagnosed at advanced stage. Patient delay was the main problem. There was significant delay by frontier health workers in identifying sinister symptoms of malignancy. Timing for diagnosis and treatment after specialist referral were comparable with other published studies.

C1 and C2 Fractures Above a Previous Fusion Treated with Internal Fixation without Fusion: A Case Report.

CASE: A 71-year-old woman sustained C1 lateral mass and type 2 odontoid fractures 3 years after C2-T2 anterior-posterior fusion. She was treated with C1-C4 instrumentation without fusion for 9 months followed by instrumentation removal to restore atlantoaxial motion. After instrumentation removal, she maintained clinically relevant cervical lateral bending, rotation, and flexion and extension. CONCLUSION: The loss of upper cervical motion after C1-C2 instrumented fusion may be debilitating for patients in the setting of previous subaxial cervical fusion. Temporary instrumentation without fusion may allow for preservation of upper cervical motion in patients with concomitant C1 and C2 fractures above a previous cervical fusion.

A new index of tooth wear. Reproducibility and application to a sample of 18- to 30-year-old university students.

A modified wear index, in which the wear of enamel and dentine are recorded separately, is described. The index was applied to estimating the prevalence and extent of tooth wear in a single convenience sample of 18- to 30-year-old students attending a university in London. The subjects were examined under good lighting in a dental chair away from a dental school. A total of 707 females and 303 males were recruited with a mean age of 21.9 years (standard deviation = 0.1, range = 18-30) and examined by 3 trained and calibrated examiners. Intra-examiner intra-class correlation coefficients showed a range of 0.44-0.88. The unweighted kappa scores were above 0.88 for enamel and dentine. The presence of enamel wear was common to all subjects, but 6.1% of the participants had more than one third of the tooth surface affected. Dentine was exposed on 5.3% of all surfaces, with the largest proportion accounting for less than 10% of the tooth surface (grade 1). The proportion of subjects with at least 1 surface with dentine exposed was 76.9% of the total population. The males had significantly more wear in dentine than the females (p = 0.001). The inter-examiner intra-class correlation coefficients for enamel and dentine were 0.87 and 0.92, respectively. The reproducibility of the index was comparable to other analyses and provides an opportunity to assess the prevalence of enamel wear in large population-based studies.

Innovative intelligent insole system reduces diabetic foot ulcer recurrence at plantar sites: a prospective, randomised, proof-of-concept study.

BACKGROUND: Prevention of diabetic foot ulcer recurrence in high risk patients, using current standard of care methods, remains a challenge. We hypothesised that an innovative intelligent insole system would be effective in reducing diabetic foot ulcer recurrence in such patients. METHODS: In this prospective, randomised, proof-of-concept study, patients with diabetes, and with peripheral neuropathy and a recent history of plantar foot ulceration were recruited from two multidisciplinary outpatient diabetic foot clinics in the UK, and were randomly assigned to either intervention or control. All patients received an insole system, which measured plantar pressure continuously during daily life. The intervention group received audiovisual alerts via a smartwatch linked to the insole system and offloading instructions when aberrant pressures were detected; the control group did not receive any alerts. The primary outcome was plantar foot ulcer occurrence within 18 months. This trial is registered with ISRCTN, ISRCTN05585501, and is closed to accrual and complete. FINDINGS: Between March 18, 2014, and Dec 20, 2016, 90 patients were recruited and consented to the study, and 58 completed the study. At follow-up, ten ulcers from 8638 person-days were recorded in the control group and four ulcers from 11 835 person-days in the intervention group: a 71% reduction in ulcer incidence in the intervention group compared with the control group (incidence rate ratio 0·29, 95% CI, 0·09-0·93; p=0·037). The number of patients who ulcerated was similar between groups (six of 26 [control group] vs four of 32 [intervention group]; p=0·29); however, individual plantar sites ulcerated more often in the control group (ten of 416) than in the intervention group (four of 512; p=0·047). In an exploratory analysis of good compliers (n=40), ulcer incidence was reduced by 86% in the intervention group versus control group (incidence rate ratio 0·14, 95% CI 0·03-0·63; p=0·011). In the exploratory analysis, plantar callus severity (change from baseline to 6 months) was greater in re-ulcerating patients (6·5, IQR 4·0-8·3) than non-re-ulcerating patients (2·0, 0·0-4·8; p=0·040). INTERPRETATION: To our knowledge, this study is the first to show that continuous plantar pressure monitoring and dynamic offloading guidance, provided by an innovative intelligent insole system, can lead to a reduction in diabetic foot ulcer site recurrence. FUNDING: Diabetes UK and Orpyx Medical Technologies.

PLGA-microsphere mediated clearance of bilirubin in temporarily hyperbilirubinemic rats: an alternate strategy for the treatment of experimental jaundice.

In the present study, we have demonstrated the suitability of microspheres in removal of plasma bilirubin from systemic circulation of hyperbilirubinemic rats. Poly (lactide co-glycolide) microspheres (PLGA microspheres) have been shown to bind with bilirubin in both a concentration and time dependent manner. The binding affinity of bilirubin to microspheres was enhanced when rat serum albumin (RSA) was loaded into the microspheres. On evaluating the potential of microspheres in elimination of bilirubin from the systemic circulation, RSA bearing microspheres were found to be competent in both removing bilirubin from the systemic circulation and controlling elevated plasma levels of liver function enzymes in temporarily hyperbilirubinemic rats. On the basis of results of the present study, we suggest that microsphere-based delivery system may help in development of safe, effective and alternate strategy for the treatment of hyperbilirubinemic conditions in model animals.

Dialysis membrane-induced oxidative stress: role of heme oxygenase-1.

Dialysis membranes have been reported to induce monocyte apoptosis. We studied the role of oxidative stress in the induction of dialysis membrane-induced monocyte apoptosis. Superoxide dismutase, a superoxide scavenger, prevented dialysis membrane-induced monocyte apoptosis. Similarly, other antioxidants also inhibited dialysis membrane- induced apoptosis. In addition, the interaction of dialysis membranes with monocytes was associated with the generation of molecules leading to oxidative stress such as superoxide and TBARS. Interestingly, pre-induction of heme oxygenase (HO)-1 by hemin prevented dialysis membrane-induced monocyte apoptosis, whereas inhibition of HO-1 activity (treatment with tin protoporphyrin, SN-P) enhanced dialysis membrane-induced monocyte apoptosis. We suggest that oxidative injury associated with dialysis membrane and monocyte interaction plays a role in monocyte injury. Pre-induction of HO-1 may attenuate dialysis membrane-induced monocyte apoptosis.

Osteonecrosis and bisphosphonates in oral and maxillofacial surgery.

Bisphosphonates are a class of compounds approved for the treatment of multiple myeloma, hypercalcemia of malignancy, osteolytic lesions of metastatic disease, Paget's disease, and most commonly, osteoporosis. Recently, these drugs have been associated with a new clinical entity, bisphosphonate related osteonecrosis (BRON) which is characterized by jaw necrosis that typically presents following dentoalveolar surgery. The pathogenesis for this complication appears to related to bisphosphonate mediated inhibition of osteoclast function and normal bone remodeling. This complication can have a significant impact on the quality of life for those patients with advanced stages of necrosis.

Optimization of Water/Oil/Surfactant System for Preparation of Medium-Chain-Length Poly-3-Hydroxyalkanoates (mcl-PHA)-Incorporated Nanoparticles via Nanoemulsion Templating Technique.

Polymeric nanoparticles gain a widespread interest in food and pharmaceutical industries as delivery systems that encapsulate, protect, and release lipophilic compounds such as omega-3 fatty acids, fat-soluble vitamins, carotenoids, carvedilol, cyclosporine, and ketoprofen. In this study, medium-chain-length poly-3-hydroxyalkanoate (mcl-PHA)-incorporated nanoparticle was developed via facile organic solvent-free nanoemulsion templating technique. The water content (W/surfactant-to-oil (S/O)), S/O, and Cremophor EL-to-Span 80 (Cremo/Sp80) ratios were first optimized using response surface methodology (RSM) to obtain nanoemulsion template prior to incorporation of mcl-PHA. Their effects on nanoemulsion formation were investigated. The mcl-PHA-incorporated nanoparticle system showed a good preservation capability of ß-carotene and extended storage stability.

Phospholipid diversity: correlation with membrane-membrane fusion events.

The transport of various metabolically important substances along the endocytic and secretory pathways involves budding as well as fusion of vesicles with various intracellular compartments and plasma membrane. The membrane-membrane fusion events between various sub-compartments of the cell are believed to be mainly mediated by so-called "fusion proteins". This study shows that beside the proteins, lipid components of membrane may play an equally important role in fusion and budding processes. Inside out (ISO) as well as right side out (RSO) erythrocyte vesicles were evaluated for their fusogenic potential using conventional membrane fusion assay methods. Both fluorescence dequenching as well as content mixing assays revealed fusogenic potential of the erythrocyte vesicles. Among two types of vesicles, ISO were found to be more fusogenic as compared to the RSO vesicles. Interestingly, ISO retained nearly half of their fusogenic properties after removal of the proteins, suggesting the remarkable role of lipids in the fusion process. In another set of experiments, fusogenic properties of the liposomes (subtilosome), prepared from phospholipids isolated from Bacillus subtilis (a lower microbe) were compared with those of erythrocyte vesicles. We have also demonstrated that various types of vesicles upon interaction with macrophages deliver encapsulated materials to the cytosol of the cells. Membrane-membrane fusion was also followed by the study, in which a protein synthesis inhibitor ricin A (that does not cross plasma membrane), when encapsulated in the erythrocyte vesicles or subtilosomes was demonstrated to gain access to the cytosol.

Role of fusogenic non-PC liposomes in elicitation of protective immune response against experimental murine salmonellosis.

Earlier we have demonstrated that novel fusogenic liposomes made up of lipid from Escherichia coli (escheriosomes) have strong tendency to fuse with the plasma membrane of target cells and thereby delivering the entrapped contents into their cytosol. The delivery of entrapped antigen in cytosol of the target cells ensues its processing and presentation along with MHC class I pathway that eventually elicit antigen specific cytotoxic T cells. The result of the present study revealed that immunization of BALB/c mice with escheriosome-encapsulated Salmonella typhimurium (S. typhimurium) cytosolic antigens resulted in the augmentation of antigen specific cytotoxic T cell lymphocyte as well as IgG responses. In contrast, free or conventional liposome (PC liposome) encapsulated antigen failed to induce CD8+ CTLs in the immunized animals. Further, immunization with escheriosome-encapsulated antigen resulted in significant enhancement in the release of IFN-gamma and IgG2a in the experimental animals. Interestingly, the immunization with escheriosome-encapsulated antigen resulted in upregulation of CD80 and CD86 on the surface of antigen presenting cells (APCs) as well. Finally, the results of the present study reveal that immunization of animals with escheriosomes encapsulated antigen protected them against virulent S. typhimurium infection. This was evident by increased survival, and reduced bacterial burden in vital organs of the immunized animals. The data of the present study suggest that escheriosomes can emerge as an effective vehicle for intracellular delivery of antigen and thus hold promise in development of liposome based vaccine against Salmonella and other intracellular pathogens.

Prostate cancer chemoprevention by green tea: in vitro and in vivo inhibition of testosterone-mediated induction of ornithine decarboxylase.

Recently, we have shown that ornithine decarboxylase (ODC), a rate-controlling enzyme in the polyamine biosynthetic pathway, is overexpressed in prostate cancer (PCA) and prostatic fluid in humans (R. R. Mohan et al., Clin. Cancer Res., 5: 143-147, 1999). ODC is also characterized as an androgen-responsive gene, and the androgenic stimulation regulates the development and growth of both normal and tumorigenic prostate cells. Thus, chemopreventive approaches aimed toward the modulation of ODC could be effective against PCA. Green tea polyphenols (GTPs) possess strong chemopreventive properties against a variety of animal tumor models and in some human epidemiological studies. At least two epidemiological studies have suggested that people who consume tea regularly may have a decreased risk of PCA. In this study, we investigated the effect of GTPs against testosterone-mediated induction of ODC in human prostate carcinoma cells, LNCaP as an in vitro model, and in Cpb:WU rats and C57BL/6 mice as in vivo models. Treatment of LNCaP cells with testosterone resulted in induction of ODC activity in a dose-dependent manner. Pretreatment of the cells with GTPs resulted in a significant inhibition of testosterone-caused induction of ODC activity in a dose-dependent manner. Similar effects of GTPs were observed in anchorage-independent growth assay of LNCaP cells where pretreatment of the cells with GTP was found to result in dose-dependent inhibition of colony formation. Testosterone treatment of the cells resulted in a significant increase in the level of ODC mRNA, and this increase was almost completely abolished by prior treatment of the cells with GTPs. The administration of testosterone (10 mg/kg body weight, i.p.) to sham-operated and castrated Cpb:WU rats resulted in 2- and 38-fold increases in ODC activity, respectively, in the ventral prostate. Oral feeding of 0.2% GTPs in drinking water for 7 days before testosterone administration resulted in 20 and 54% decreases in testosterone-caused induction of ODC activity in sham-operated and castrated rats, respectively. Similar results were obtained with C57BL/6 mice, where testosterone treatment at similar dosage resulted in a 2-fold increase in ODC activity in the ventral prostate and prior oral feeding with 0.2% GTPs resulted in 40% inhibition in this induction.

Characterization of un-plasticized and propylene carbonate plasticized carboxymethyl cellulose doped ammonium chloride solid biopolymer electrolytes.

Two solid biopolymer electrolytes (SBEs) systems of carboxymethyl cellulose doped ammonium chloride (CMC-AC) and propylene carbonate plasticized (CMC-AC-PC) were prepared via solution casting technique. The ionic conductivity of SBEs were analyzed using electrical impedance spectroscopy (EIS) in the frequency range of 50 Hz-1 MHz at ambient temperature (303K). The highest ionic conductivity of CMC-AC SBE is 1.43 × 10(-3)S/cm for 16 wt.% of AC while the highest conductivity of plasticized SBE system is 1.01 × 10(-2)S/cm when added with 8 wt.% of PC. TGA/DSC showed that the addition of PC had increased the decomposition temperature compared of CMC-AC SBE. Fourier transform infrared (FTIR) spectra showed the occurrence of complexation between the SBE components and it is proved successfully executed by Gaussian software. X-ray diffraction (XRD) indicated that amorphous nature of SBEs. It is believed that the PC is one of the most promising plasticizer to enhance the ionic conductivity and performance for SBE system.

Doxorubicin-loaded photosensitive magnetic liposomes for multi-modal cancer therapy.

Multifunctional magnetic nanosystems have attracted an enormous attention of researchers for their potential applications in cancer diagnostics and therapy. The localized nanotherapies triggered by the external stimuli, like magnetic fields and visible light, are significant in clinical applications. We report a liposomal system that aims to treat cancer by magnetic hyperthermia, photodynamic therapy and chemotherapy simultaneously. The liposomes enclose clinically used photosensitizer m-THPC (Foscan) and anti-cancer drug doxorubicin, in its hydrophobic lipid bilayers, and contains magnetite nanoparticles in hydrophilic core. Three different sizes of magnetic nanoparticles (10, 22 and 30nm) and liposomes (40, 70 and 110nm) were used in this study. Magnetite single domain nanoparticles forming the magnetic core were superparamagnetic but liposomes expressed slight coercivity and hysteresis due to the clustering of nanoparticles in the core. This enhanced the heating efficiency (specific power loss) of the liposomes under an AC field (375kHz, 170Oe). Cell viability and toxicity were studied on HeLa cells using MTT assay and proteomic analysis. Confocal and fluorescence microscopy were used to study the photosensitizer's profile and cells response to combined therapy. It revealed that combined therapy almost completely eliminated the cancer cells as opposed to the separate treatments. Magnetic hyperthermia and photodynamic therapies were almost equally effective whereas chemotherapy showed the least effect.

Antimicrobial activity of clove oil and its potential in the treatment of vaginal candidiasis.

In the present study, we evaluated antimicrobial activity of clove oil against a range of fungal pathogens including that responsible for urogenital infection. Clove oil was found to possess strong antifungal activity against opportunistic fungal pathogens such as Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus, etc. The oil was found to be extremely successful in the treatment of experimental murine vaginitis in model animals. On evaluating various formulations, topical administration of the liposomized clove oil was found to be most effective against treatment of vaginal candidiasis.