Successful rehabilitation and release of a powerful owl chick with suspected rodenticide poisoning.

The successful rehabilitation and release of raptor chicks can be challenging, especially when the chicks are still in the post-fledging dependency period. Here, we report on a recently fledged powerful owl chick that was held in care for 33 days before being successfully reunited with its parents. We document the steps undertaken during the entire process from collection from the wild to post-release monitoring and recommend clinical procedures for treatment of raptors entering veterinary facilities. Success of this rehabilitation was facilitated by early care and treatment for potential rodenticide poisoning, as well as the integration of citizen scientists monitoring the family unit in the field while the chick was in care and during the post-release period. Given the emerging evidence of widespread rodenticide poisoning in raptors both in Australia and globally, it is critical to suspect all raptors may have been exposed to anticoagulant rodenticides and commence treatment with vitamin K immediately. Routine treatment for rodenticides early increases the probability of successful recovery post-trauma as well as reducing the time in treatment as much as possible.

Students' perceptions of vertical and horizontal integration in a discipline-based dental school.

INTRODUCTION: Integration is a key concern in discipline-based undergraduate dental curricula. Therefore, this study compared feedback on integration from students who participated in different instructional designs in a Comprehensive Patient Care course. METHODS: The study was conducted at the University of Pretoria (2009-2011). Third-year cohorts (Cohorts A, B and C) participated in pre-clinical case-based learning, whilst fourth-year cohorts (Cohorts D and E) received didactic teaching in Comprehensive Patient Care. Cohorts A, D and E practised clinical Comprehensive Patient Care in a discipline-based clinic. Cohort B conducted their Comprehensive Patient Care patient examinations in a dedicated facility supervised by dedicated faculty responsible to teach integration. Students had to indicate on visual analogue scales whether the way they were taught at the school helped them to integrate knowledge from the same (horizontal integration) and preceding (vertical integration) year of study. The end-points of the scales were defined as 'definitely' and 'not at all'. Analysis of variance (ANOVA) was employed to measure the differences between cohorts according to the year of study. RESULTS: Third-year case-based learning cohorts rated the horizontal integration close to 80/100 and vertical integration ranging from 64 to 71/100. In year four, Cohort B rated vertical and horizontal integration 9-15% higher (ANOVA, P < 0.05) than Cohorts A and D. In year five, Cohort A rated vertical and horizontal integration 11-18% higher (ANOVA, P < 0.05) than Cohorts D and E. CONCLUSION: Pre-clinical case-based learning and Comprehensive Patient Care supervised by dedicated faculty were associated with more favourable perceptions about integration in the discipline-based undergraduate dental curriculum.

Developing students' clinical reasoning skills: correlates of perceived relevance of two teaching and learning approaches.

INTRODUCTION: 'Relevance' is a key concept in adult learning. Hence, this study sought to examine students' perceptions of relevance of the teaching and learning in relation to different instructional designs employed in a Comprehensive Patient Care (CPC) course that aims to develop integrated clinical reasoning skills. METHODS: Third to fifth year students (2009-2011) were asked to anonymously rate the relevance of the instructional design (RELID) they participated in by means of visual analogue scales at the School of Dentistry, University of Pretoria. They were also asked to rate their perceptions of the alignment between teaching and learning and outcomes (ATLO), assessments' contribution to learning (ACL), course organisation (CO) and teacher competence (TC). RELID served as the outcome measure in stepwise linear regression analyses. ATLO, ACL, CO, TC and the instructional design (case-based learning (CBL = 1) and the combination of discipline-based and lecture-based teaching in CPC (DB-LBT = 0)) served as the co-variables for each of the years of study. RESULTS: The analyses showed positive correlations between RELID and ATLO and between RELID and ACL for all the years of study. RELID was associated with TC in year three and four and CO was associated with RELID in year four and five. CBL outperformed DB-LBT in terms of perceived relevance of the teaching and learning. CONCLUSION: The results suggest that students' perceptions of the relevance of the instructional design may be enhanced when outcomes, teaching, learning and assessment are constructively aligned during the development of clinical reasoning skills.

Socio-demographic and academic correlates of clinical reasoning in a dental school in South Africa.

INTRODUCTION: There are no empirical studies that describe factors that may influence the development of integrated clinical reasoning skills in dental education. Hence, this study examines the association between outcomes of clinical reasoning in relation with differences in instructional design and student factors. MATERIALS AND METHODS: Progress test scores, including diagnostic and treatment planning scores, of fourth and fifth year dental students (2009-2011) at the University of Pretoria, South Africa served as the outcome measures in stepwise linear regression analyses. These scores were correlated with the instructional design (lecture-based teaching and learning (LBTL = 0) or case-based teaching and learning (CBTL = 1), students' grades in Oral Biology, indicators of socio-economic status (SES) and gender. RESULTS: CBTL showed an independent association with progress test scores. Oral Biology scores correlated with diagnostic component scores. Diagnostic component scores correlated with treatment planning scores in the fourth year of study but not in the fifth year of study. 'SES' correlated with progress test scores in year five only, while gender showed no correlation. CONCLUSION: The empirical evidence gathered in this study provides support for scaffolded inductive teaching and learning methods to develop clinical reasoning skills. Knowledge in Oral Biology and reading skills may be important attributes to develop to ensure that students are able to reason accurately in a clinical setting.

Developing integrated clinical reasoning competencies in dental students using scaffolded case-based learning - empirical evidence.

INTRODUCTION: This study provides empirical evidence of the development of integrated clinical reasoning in the discipline-based School of Dentistry, University of Pretoria, South Africa. Students were exposed to case-based learning in comprehensive patient care (CPC) in the preclinical year of study, scaffolded by means of the four-component instructional design model for complex learning. METHODS: Progress test scores of third- to fifth-year dental students, who received case-based teaching and learning in the third year (2009-2011), were compared to the scores of preceding fourth- and fifth-year cohorts. These fourth- and fifth-year cohorts received content-based teaching concurrently with their clinical training in CPC. The progress test consisted of a complex case study and 32 MCQs on tracer conditions. Students had to gather the necessary information and had to make diagnostic and treatment-planning decisions. RESULTS: Preclinical students who participated in the case-based teaching and learning achieved similar scores compared to final-year students who received lecture-based teaching and learning. Final-year students who participated in the case-based learning made three more correct clinical decisions per student, compared to those who received content-based teaching. Students struggled more with treatment-planning than with diagnostic decisions. CONCLUSION: The scaffolded case-based learning appears to contribute to accurate clinical decisions when compared to lecture-based teaching. It is suggested that the development of integrated reasoning competencies starts as early as possible in a dental curriculum, perhaps even in the preclinical year of study. Treatment-planning should receive particular attention.

Developing clinical reasoning in the classroom - analysis of the 4C/ID-model.

OBJECTIVES: The purpose of this study is to provide a theoretical rationale for the implementation of the four-component instructional design model for complex learning (4C/ID-model) at the University of Pretoria with the aim of systematically developing the clinical reasoning of undergraduate dental students in a classroom setting. METHODS: Recent literature provides a rationale for the use of the 4C/ID-model to teach clinical reasoning in terms of four strategic teaching and learning needs: (i) the need for authenticity in the learning process; (ii) the need to manage cognitive load during the learning process; (iii) the need for repeated practice; (iv) a need for valid assessment, feedback and reflection. RESULTS AND DISCUSSION: The literature review indicated that the 4C/ID-model makes provision for teaching and learning in an authentic context and proposes systematically structured methods that could be practically applied to manage cognitive load during repetitive exercises. The model also makes provision for cognitive feedback following assessment in order to eliminate misconceptions about content and to develop the cognitive strategies of the learner. CONCLUSIONS: On the basis of the literature review above, it is recommended that the 4C/ID-model be considered as a basis for classroom teaching and learning to develop competence in clinical reasoning in undergraduate dental students, even at pre-clinical level. The model may also have an application in medical education.

An analysis of complaints against oral health professionals charged with misconduct at the HPCSA: 2004-2009.

AIM: This study investigates the nature, frequency, and outcome of complaints relating to misconduct laid against oral healthcare professionals (OHPs), charged with misconduct in South Africa. METHODS: Records of the Health Professions Council of South Africa (2004-2009) were analysed and classified using the ethical rules as a reference. "Clinically-related complaints" and "fraud" were added as extra categories. The nature and outcome of the complaints and the penalties were quantified, and the detailed nature of the complaints was qualitatively reported. RESULTS: Two percent of the registered dentists and 5.5% of the registered dental therapists were charged with misconduct. Clinically related complaints (59%) and fraud (29%) were most prevalent amongst the accused dentists. Fraud (46%), clinically related complaints (19%), advertising (15%), infection control (8%), and creating expectations that could not be met (8%) were the most common complaints against dental therapists. CONCLUSIONS: Substandard dental treatment and fraud were the main reasons for patient dissatisfaction that led to OHPs being charged with misconduct. Both these undesirable practices may be financially motivated. OHPs should take cognisance of these statistics and should adjust their professional approach accordingly in order to reflect acceptable ethical behaviour.

Novel mutations in the HPS1 gene among Puerto Rican patients.

Hermansky-Pudlak syndrome (HPS) is a disorder of oculocutaneous albinism (OCA) and platelet storage pool deficiency. Eight different disease-causing genes have been identified, whose gene products are thought to be involved in the biogenesis of lysosome-related organelles. HPS type 1 (HPS-1) is the most common HPS subtype in Puerto Rico, with a frequency of 1:1800 in the northwest of the island due to a founder mutation, i.e. a 16-bp duplication in exon 15 of the HPS1 gene (c.1472_1487dup16; p.H497QfsX90). We identified three Puerto Rican HPS-1 patients who carried compound heterozygous HPS1 mutations. One patient was heterozygous for c.937G>A, causing a missense mutation (p.G313S) at the 3 splice junction of exon 10. This mutation resulted in activation of a cryptic intronic splice site causing an aberrantly spliced HPS1 mRNA that included 144-bp of intronic sequence, producing 11 novel amino acids followed by a stop codon. The other two patients were heterozygous for the previously reported c.972delC in HPS1, resulting in a frameshift and a premature stop codon (p.M325WfsX6). These findings indicate that, among Puerto Ricans, other HPS1 mutations apart from the 16-bp duplication should be considered in the analysis of this population.

Strategy for teaching communication skills in dentistry.

AIM: To develop and evaluate a teaching strategy for teaching communication skills in dentistry. METHODOLOGY: Phase I: Development and implementation of a course in communication skills. Phase II: Implementation of a teaching strategy by means of an experiential learning strategy complemented by a didactic teaching strategy. SUBJECTS: Third year dental students (n = 67). The instruments included the following: (i) Study guide; (ii) Case study; (iii) Assessment rubric; (iv) Two questionnaires: "Patient's and "Dentist's feedback; (v) Standardised patient. RESULTS: The class as a whole scored significantly higher after training compared to before training (p < 0.0001). Both male and female students rated the value, appropriateness and effectiveness of the teaching strategy employed during the study, rather highly (4.18 and 4.26 on a five-point Likert scale, respectively). CONCLUSION: The teaching strategy employed for teaching third year dental students communication skills, proved to be effective and was perceived by the students as a valuable and appropriate strategy.

The secretory mechanisms in equine platelets are independent of cytoskeletal polymerization and occur through membrane fusion.

Studies in animal models are useful to understand the basic mechanisms involved in hemostasis and the functional differences among species. Ultrastructural observations led us to predict differences in the activation and secretion mechanisms between equine and human platelets. The potential mechanisms involved have been comparatively explored in the present study. Equine and human platelets were activated with thrombin (0.5 U/ml) and collagen (20 µg/ml), for 90 seconds, and samples processed to evaluate: i) ultrastructural changes, by electron microscopy, ii) actin polymerization and cytoskeletal assembly, by polyacrylamide gel electrophoresis, and iii) specific molecules involved in activation and secretion, by western blot. In activated human platelets, centralization of granules, cytoskeletal assembly and fusion of granules with the open canalicular system were observed. In activated equine platelets, granules fused together forming an organelle chain that fused with the surface membrane and released its content directly outside the platelets. Human platelets responded to activation with actin polymerization and the assembly of other contractile proteins to the cytoskeleton. These events were almost undetectable in equine platelets. When exploring the involvement of the synaptosomal-associated protein-23 (SNAP-23), a known regulator of secretory granule/plasma membrane fusion events, it was present in both human and equine platelets. SNAP-23 was shown to be more activated in equine platelets than human platelets in response to activation, especially with collagen. Thus, there are significant differences in the secretion mechanisms between human and equine platelets. While in human platelets, activation and secretion of granules depend on mechanisms of internal contraction and membrane fusion, in equine platelets the fusion mechanisms seem to be predominant.

Clinical and cellular characterisation of Hermansky-Pudlak syndrome type 6.

BACKGROUND: In the last decade, Hermansky-Pudlak syndrome (HPS) has arisen as an instructive disorder for cell biologists to study the biogenesis of lysosome related organelles (LROs). Of the eight human HPS subtypes, only subtypes 1 through 5 are well described. AIM: To characterise extensively the HPS-6 subtype, caused by defects in HPS6, a subunit of the biogenesis of lysosome related organelles complex-2 (BLOC-2). METHODS: Mutation analysis for the HPS6 gene was performed on DNA from our group of unclassified HPS patients. The clinical phenotype of patients with HPS6 mutations was then carefully ascertained, and their cultured dermal melanocytes were employed for cellular immunofluorescence studies. RESULTS: Molecular studies showed a variety of mutations in the single exon HPS6 gene, including frame shift, missense, and nonsense mutations as well as a approximately 20 kb deletion spanning the entire HPS6 genomic region. Cellular studies revealed that the melanogenic proteins tyrosinase and tyrosinase related protein 1 failed to be efficiently delivered to the melanosomes of HPS-6 patients, explaining their hypopigmentation. Clinical studies indicated that HPS-6 patients exhibit oculocutaneous albinism and a bleeding diathesis. Importantly, granulomatous colitis and pulmonary fibrosis, debilitating features present in HPS subtypes 1 and 4, were not detected in our HPS-6 patients. CONCLUSION: The HPS-6 subtype resembles other BLOC-2 defective subtypes (that is, HPS-3 and HPS-5) in its molecular, cellular and clinical findings. These findings are not only important for providing a prognosis to newly diagnosed HPS-6 patients, but also for further elucidation of HPS function in the biogenesis of LROs.

Platelet structural pathology in a patient with the X-linked GATA-1, R216Q mutation.

The ultrastructural pathology of GATA-1, V205M and G208S macrothrombocytes was discussed in earlier investigations. This study has used the same technology to evaluate macrothrombocytes from a patient with the GATA-1, R216Q mutation. Some of the pathological features observed in macrothrombocytes from patients with the V205M and G208S variations including hypo- and agranular platelets, tubular inclusions and platelets within platelets, as well as platelets within platelets within platelets were identified. However, tubular membrane sheets in megakaryocytes and platelets of the V205M and G208S types and large groups of platelets attached to platelets to form megathrombocytes were not observed. The unique pathology of the megathrombocytes from this patient was the near absence of dense bodies in his giant cells. Storage Pool Deficiency, together with large platelets, defective adhesion and aggregation of his macrocytes under shear stress to vWF and collagen and defective clot retraction may contribute to the pathogenesis of his bleeding disorder.

The role of Rab38 in platelet dense granule defects.

BACKGROUND: The fawn-hooded hypertensive (FHH) rat has a mutation in the Rab38 gene that is associated with a platelet dense granule storage pool disease. OBJECTIVE: To better characterize the expression and function of Rab38 in FHH rat and human megakaryocytes and platelets. PATIENTS AND METHODS: Rab38 expression in FHH rat and normal tissues was demonstrated by western blotting. Platelet and megakaryocyte morphology and Rab38 expression were examined by transmission electron microscopy and by immunofluorescence confocal microscopy. Platelet surface glycoprotein and P-selectin expression and total serotonin content were assessed by flow cytometry. RESULTS: Rab38 was not expressed in FHH rat tissues, and FHH rat platelets and megakaryocytes lacked dense granules. FHH rat platelets had normal expression of surface glycoproteins and of surface P-selectin in response to thrombin. The total serotonin content in FHH rat platelets was similar to that in Brown Norway rat platelets. In a megakaryocyte cell line, Rab38 was expressed in a granular perinuclear and cytoplasmic pattern. There was partial colocalization with serotonin, and minimal colocalization with von Willebrand factor and lysosomal proteins. CONCLUSIONS: The lack of Rab38 expression in the FHH rat results in the absence of normal dense granules in the megakaryocytes and platelets, which have otherwise normal structure and function. Rab38 may play a role in the development of dense granules in the megakaryocytes and platelets.

Development and implementation of communication skills in dentistry: an example from South Africa.

Dental students should realise early in their careers -- in dental school -- the importance of developing and mastering sound communication skills with patients. As a result, the aim of this study was to develop and implement a course in communication skills for third year dental students. The methodology employed in the study comprised the following three phases: Phase I: identification of specific outcomes essential for the dentist to be competitive in the emerging South African dental environment. Phase II: development of an outcome-based course according to the South African Qualifications Authority format (Purpose, Embedded knowledge, Assessment criteria). Phase III: implementation of the course. Implementation of the course involved a pre- and post-training cycle. The subjects were 67 third year dental students. The following instruments were employed: a study guide; a case study; an assessment rubric; two questionnaires, namely "Patient's" feedback and "Dentist's" feedback; a standardised patient. The results were as follows: the class as a whole scored significantly higher during training cycle 2 compared with training cycle 1 (P < 0.0001). The important roles of trust, empathy and active listening in establishing a meaningful relationship with a patient, which was conveyed by means of the course, were emphasised by the majority of students.

Proteomic analysis of platelet alpha-granules using mass spectrometry.

BACKGROUND: Platelets have three major types of secretory organelles: lysosomes, dense granules, and alpha-granules. alpha-Granules contain several adhesive proteins involved in hemostasis, as well as glycoproteins involved in inflammation, wound healing, and cell-matrix interactions. This article represents the first effort to define the platelet alpha-granule proteome using mass spectrometry (MS). METHODS: We prepared a subcellular fraction enriched in intact alpha-granules from human platelets using sucrose gradient ultracentrifugation. alpha-Granule proteins were separated and identified using sodium dodecylsulfate polyacrylamide gel electrophoresis and liquid chromatography-tandem MS. RESULTS: In the sucrose fraction enriched in alpha-granules, we identified 284 non-redundant proteins, 44 of which appear to be new alpha-granule proteins, on the basis of a literature review. Immunoelectron microscopy confirmed the presence of Scamp2, APLP2, ESAM and LAMA5 in platelet alpha-granules for the first time. We identified 65% of the same proteins that were detected in the platelet releasate (J. A. Coppinger et al. [Blood 2004;103: 2096-104]) as well as additional soluble and membrane proteins. Our method provides a suitable tool for analyzing the granule proteome of patients with storage pool deficiencies.

The critical role of myosin IIA in platelet internal contraction.

BACKGROUND: Shape change and centralization of granules surrounded by a microtubular coil (internal contraction) are among the earliest morphologic changes observed following platelet activation. Myosin IIA contributes to initiation of platelet shape change, but its role in internal contraction has not been defined. OBJECTIVE: To define the contribution of myosin IIA to platelet internal contraction. METHODS: Aspirin-treated platelets suspended in calcium-free buffer were activated with a low concentration (25 nm) of the thromboxane A(2) analog U46619 which initiated shape change and internal contraction via a Rho kinase pathway. Shape change and internal contraction were assessed by aggregometry and transmission electron microscopy (TEM), and Rho activation and myosin regulatory light chain (MRLC) phosphorylation were studied concurrently. RESULTS AND CONCLUSIONS: Low-concentration blebbistatin (10 microm) inhibited internal contraction in the majority of platelets with minimal inhibition of shape change without significant suppression of MRLC phosphorylation. Higher blebbistatin concentrations (25-100 microm) produced concentration-dependent inhibition of aggregation, shape change, Rho activation, and MRLC phosphorylation. These data demonstrate: (i) direct platelet myosin IIA participation in internal contraction; and (ii) inhibition of Rho activation and MRLC phosphorylation by >10 microm blebbistatin.

Optimized temporal response in multichannel two-photon fluorescence lifetime microscopy using a photonic crystal fibre.

The integration of fibre optics into an imaging system for the convenient delivery and collection of light has resulted in many hybrid forms of novel biomedical optical instrumentation. Although it is extremely robust and cost effective, fibre integration requires special consideration in a time-domain fluorescence lifetime imaging schema where multipath propagation in the fibre causes significant spread in photon transit times. In this study, we investigated the effect of the length of a multimode collection fibre on the temporal performance of a multichannel fluorescence lifetime microscope and demonstrated the effectiveness of a photonic crystal fibre as a means of optimizing the collection and delivery of emitted fluorescence in terms of temporal resolution. The findings are pertinent to all studies that employ a multimode optical fibre to collect and deliver an emitted fluorescence signal from a sample to a remote detector for measurement of the characteristic fluorescence lifetime.