Fine-tuning the standard setting of objective structured practical examinations in clinical anatomy.

The objective structured practical examination (OSPE) is a reliable assessment of practical skills in anatomy teaching. It is often administered as low-stake assessments to track progress at multiple time points in anatomy curricula. Standard-setting OSPEs to derive a pass mark and to ensure assessment quality and rigor is a complex task. This study compared standard-setting outcomes of clinical anatomy OSPEs determined by traditional criterion-referenced (Ebel) and norm-referenced ("mean minus standard deviation") methods in comparison to hybrid methods which apply both criterion-referenced and norm-referenced approaches in setting examination standards. The hybrid approaches utilized included the "Cohen method" and an adaptation of the "Taylor's method," which is an improvement on the Cohen method. These diverse standard-setting methods were applied retrospectively to 16 anatomy OSPEs conducted over 4 years for first- and second-year medical students in a graduate Doctor of Medicine Program at Griffith Medical School, Australia; and the pass marks, failure rates, and variances of failure rates were compared. The application of the adaptation of Taylor's method to standard set OSPEs produced pass marks and failure rates comparable to the Ebel method, whereas the variability of failure rates was higher with the Ebel method than with the Cohen and Taylor's methods. This underscores this study's adaptation of Taylor's method as a suitable alternative to the widely accepted but resource intensive, panel-based criterion-referenced standard-setting methods such as the Ebel method, where panelists with relevant expertise are unavailable, particularly for the multiple low-stakes OSPEs in an anatomy curriculum.

Heme oxygenase-1 & 2 and their potential contribution in heme induced colorectal carcinogenesis.

BACKGROUND: Literature suggests Heme oxygenase (HO) system to be a double-edged sword which can promote both cytoprotection as well as carcinogenicity. The aim of this study was to investigate the role of heme in HO-1 and HO-2 induced colorectal carcinogenesis and the clinicopathological significance of their expressions in patients with colorectal carcinoma (CRC). METHODS: HO-1 and HO-2 expression alterations in normal colonic epithelial (FHC) and colon cancer cells (SW480) were explored following treatment with 0 µM, 25 µM, 100 µM and 250 µM concentrations of hemin, using qPCR. Fifty paired CRC and adjacent non-neoplastic samples were subjected to qPCR to determine the HO-1 and HO-2 expression. Clinicopathological associations of HO-1 and HO-2 expression levels were determined. RESULTS: Low concentrations of hemin caused upregulation and high concentration caused downregulation of HO-1 expression, whereas HO-2 expression was significantly downregulated with all hemin concentrations in FHC. HO-1 expression in SW480 was increased with all hemin concentrations and HO-2 expression was downregulated at the highest hemin concentration. HO-1 and HO-2 expressions in adjacent non-neoplastic tissue was significantly higher than that of CRC. Expression of HO-1 was significantly higher than HO-2, in both CRC and adjacent non-neoplastic tissue. Sex, HFE expression and lymph-vascular invasion were significantly correlated with HO-1 expression. HO-2 expression showed significant associations with staging, local spread and recurrence of tumour. CONCLUSION: HO-1 and HO-2 expression is respectively induced and repressed by exogenous hemin in normal colon and colon cancer cells. HO-1 and HO-2 expression profiles in CRC are correlated with the assessed clinicopathological features of CRC, suggesting the possible implications of HO expression status in CRC pathogenesis.

HFE variants in colorectal cancer and their clinicopathological correlations.

The study aimed to screen mutation of human homeostatic iron regulator (HFE) in colorectal carcinoma (CRC) and detect their associations with clinicopathological parameters. Expression of HFE was determined by quantitative polymerase chain reaction in matched CRC and non neoplastic colorectal mucosal tissue of 76 patients. Genomic DNA extracted were subjected to high high-resolution melt curve analysis and Sanger sequencing to detect mutations in HFE. The associations of the identified mutations with a variety of clinical features were determined. Approximately 60% of CRC showed low HFE expression. Of the ten 10 mutations identified in exons 2 and 4, c.187C>G (H63D), c845G>A (C282Y), c.193A>T (S65C), g.3828T>C, g.5795T>C, and g.5728G>A were known mutations. Four novel mutations were discovered; : c.184G>A, c.220T>G, c.322A>C, and c.324T>C. Heterozygous H63D and C282Y mutations were seen in 71% and 49% of cancer tissue, respectively. Tumour site (p = 0.048) and gender (p = 0.039) were significantly associated with H63D and C282Y mutation status, respectively. Local spread of cancer was significantly associated with C282Y mutations in CRC cancer and adjacent non-neoplastic tissue (p = 0.029 & and p = 0.004, respectively). There was a statistically significant association between H63D and C282Y negativity in matched non-neoplastic colorectal mucosa tissue and pathological staging of cancer (p = 0.047 & and p = 0.001, respectively). Patients with H63D and C282Y mutations in cancer tissue tend to have higher survival rates. Hence HFE mutations are common in CRC and are associated with clinicopathological parameters, implying the potential clinical significance of HFE mutations in colorectal carcinogenesis.

Hemin, a major heme molecule, induced cellular and genetic alterations in normal colonic and colon cancer cells.

Heme, a molecule abundant in red meat, is assumed to exert carcinogenic effects on normal colonic cells and tumour suppressive effects on cancer cells, though the hypothesis has not been explicitly proven yet. The present study aims to investigate hemin induced cytotoxic, genetic and biological alterations in both normal and cancerous colonic epithelial cells, which may imply its carcinogenic and anticarcinogenic properties. Normal colonic epithelial cells and colon carcinoma cells were treated with a 0-500 µM concentration of hemin for 1-4 days following which cytotoxicity and wound healing assays, western blot, rt-PCR and cell cycle analysis were performed. Interestingly, hemin was cytotoxic to normal colonic cells, but carcinoma cells were more resistant. Cell migration potential of both normal colonic cells and colon carcinoma cells was impeded by hemin. Hemin caused upregulation of both P53 and ß-catenin gene and proteins expression in normal colonic cells with concomitant cell cycle arrest at G1(Gap 1) and G2/M (Gap 2/ Mitosis). G1 and G2 cell cycle arrests were also observed in colon carcinoma cells. In conclusion, the present study confirms that hemin, a main heme molecule present in red meat, facilitates behavioural, genetic and cell cycle kinetic alterations in both normal colonic epithelial and colon carcinoma cells.

Effect of Smartphone Laparoscopy Simulator on Laparoscopic Performance in Medical Students.

BACKGROUND: This study aims to investigate if a smartphone laparoscopy simulator, SimuSurg, is effective in improving laparoscopic skills in surgically inexperienced medical students. METHODS: This is a single-blinded randomized controlled trial featuring 30 preclinical medical students without prior laparoscopic simulation experience. The students were randomly allocated to a control or intervention group (n = 15 each) and 28 students completed the study (n = 14 each). All participants performed three validated exercises in a laparoscopic box trainer and repeated them after 1 week. The intervention group spent the intervening time completing all levels in SimuSurg, whereas the control group refrained from any laparoscopic activity. A prestudy questionnaire was used to collect data on age, sex, handedness, and experience with gaming. RESULTS: The total score improved significantly between the two testing sessions for the intervention group (n = 14, median change [MC] = 182.00, P = 0.009) but not for the control group (n = 14, MC = 161.50, P = 0.08). Scores for the nondominant hand improved significantly in the intervention group (MC = 66.50, P = 0.008) but not in the control group (MC = 9.00, P = 0.98). There was no improvement in dominant hand scores for either the intervention (MC = 62.00, P = 0.08) or control (MC = 26.00, P = 0.32) groups. Interest in surgery (ß = -234.30, P = 0.02) was positively correlated with the baseline total scores; however, age, sex, and experience with video games were not. CONCLUSIONS: The results suggest that smartphone applications improve laparoscopic skills in medical students, especially for the nondominant hand. These simulators may be a cost-effective and accessible adjunct for laparoscopic training among surgically inexperienced students and clinicians.

Dissection in the Modern Medical Curriculum: An Exploration into Student Perception and Adaptions for the Future.

For centuries cadaveric dissection has been a cornerstone of medical anatomy education. However, time and financial limitations in modern, compressed medical curricula, coupled with the abundance of alternate modalities, have raised questions about the role of dissection. This study was designed to explore student perceptions of the efficacy of a dissection program for learning musculoskeletal anatomy, and possible adaptations for appropriate inclusion of dissection in the modern medical curricula. A paper-based questionnaire was used to collect data from 174 medical students after completion of cadaveric dissections. Data were analyzed using both quantitative and qualitative methods. Students strongly believed that cadaver-based learning is essential to anatomy education and modern teaching modalities only complement this. Moreover, most students reported that dissection provided an additional, immersive learning experience that facilitated active learning and helped in developing manual competencies. Students with previous dissection experience or an interest in anatomy-related specialties were significantly more likely to attend dissection sessions. Students found that the procedural dissection components enhanced the knowledge of applied anatomy and is beneficial for the development of clinical skills. They welcomed the idea of implementing more procedure-based dissections alongside lectures and prosections-based practical (PBP) sessions. Cadaveric dissection plays an integral role in medical anatomy education. Time restraints and an increased focus on clinical significance, however, demand carefully considered adaptations of existing dissection protocols. The introduction of procedure-based dissection offers an innovative, highly engaging and clinically relevant package that would amalgamate skills essential to medical practice while retaining the benefits that have allowed dissection to stand the test of time.

The role of heme iron molecules derived from red and processed meat in the pathogenesis of colorectal carcinoma.

Emerging evidence that heme iron in red meat is a risk factor for colorectal carcinogenesis is a topic that has received recent scrutiny. This review aims to summarise the mechanism of colorectal carcinogenesis by heme contained in red and processed meat. Heme iron can induce cytotoxicity by 'cytotoxic heme factor' and promote surface epithelial cell apoptosis and compensatory epithelial hyperplasia. Heme, induces peroxidation of lipids, leading to free radical formation and generation of DNA adducts in colorectal epithelial cells. In addition, heme catalyses the formation of N-nitroso-compounds, which in turn results in the initiation of colorectal carcinogenesis. Emerging data suggest that intestinal dysbiosis can promote carcinogenic properties of heme. Heme induces multiple genetic alterations by regulating WNT signalling pathway and causing mutations in major colon cancer genes such as APC, TP53 and KRAS. However, a balanced diet containing green vegetables, olive oil and calcium may reduce the carcinogenic effects of heme.

A comprehensive review of motor innervation of the hand: variations and clinical significance.

PURPOSE: The objective of the present review is to assemble the recognized anatomical variations, classifications, and clinical evidence with regard to innervation of the hand and discuss the clinical significance of these variations. METHODS: The material for this review was obtained by exploring PubMed and Google Scholar (search terms: hand innervation, variations of ulnar nerve, variations of median nerve, variations of radial nerve) as well as from standard anatomy texts. This initial search returned approximately 300 articles, which was reduced by abstract or title review. Reviewing the reference lists of significant papers uncovered further studies missed in the initial search. A few standard anatomy texts were also consulted for normal anatomy. RESULTS: The median and ulnar nerves frequently display a number of significant deviations from the traditionally taught branching patterns. The traditionally taught innervation of the hand is also found to be highly variable. This is especially evident with regard to the motor innervation of thenar muscles. These variations may be explained by the often under-recognized anastomoses that exist in the hand, such as the motor Riche-Cannieu Anastomosis. Some of these variations are associated significant clinical consequences. CONCLUSIONS: The median and ulnar nerves display many anatomical variations, often with significant clinical implications. Awareness about these variations is clinically important when interpreting clinical examination findings, electrophysiological and radiological investigation as well as during management of patients in terms of surgical and anesthetic procedures.

A critical overview on the biological and molecular features of red and processed meat in colorectal carcinogenesis.

A recent investigation by the World Health Organisation (WHO) has found that the consumption of processed meat and potentially red meat promotes carcinogenesis and can increase the risk of colorectal cancer. This literature review aims to summarise both the red and processed meat molecules associated with colorectal carcinogenesis and investigate their relationship with the pathogenic process of colorectal cancer. Literature relating to the carcinogenic effect of red and processed meat molecules was critically reviewed. There are multiple molecules present in red and processed meat with a potential carcinogenic effect on colorectal tissues. Processed meat is more carcinogenic compared to red meat because of the abundance of potent nitrosyl-heme molecules that form N-nitroso compounds. Studies have also noted that other molecules such as polycyclic aromatic hydrocarbons and heterocyclic amines have potential mechanisms for the initiation of colorectal cancer pathogenesis. The non-human sugar molecule N-glycolylneuraminic acid may account for the carcinogenic effects of pork despite its heme content being comparable to that of chicken. Red meat products, especially those that have been processed, have a wide variety of carcinogenic molecules known to increase the risk of colorectal cancer. Thus, the outcome of this review is consistent with the recent findings of WHO.

Integrating gross pathology into teaching of undergraduate medical science students using human cadavers.

Human cadavers offer a great opportunity for histopathology students for the learning and teaching of tissue pathology. In this study, we aimed to implement an integrated learning approach by using cadavers to enhance students' knowledge and to develop their skills in gross tissue identification, handling and dissection techniques. A total of 35 students enrolled in the undergraduate medical science program participated in this study. A 3-hour laboratory session was conducted that included an active exploration of cadaveric specimens to identify normal and pathological tissues as well as tissue dissection. The majority of the students strongly agreed that the integration of normal and morbid anatomy improved their understanding of tissue pathology. All the students either agreed or strongly agreed that this laboratory session was useful to improve their tissue dissection and instrument handling skills. Furthermore, students from both cohorts rated the session as very relevant to their learning and recommended that this approach be added to the existing histopathology curriculum. To conclude, an integrated cadaver-based practical session can be used effectively to enhance the learning experience of histopathology science students, as well as improving their manual skills of tissue treatment, instrument handling and dissection.

Role of cadaveric dissections in modern medical curricula: a study on student perceptions.

The shift from traditional medical curricula to newer teaching and learning approaches such as problem-based learning has often resulted in omission or significant reduction of cadaveric dissections as a method of learning anatomy. The objective of this study was to evaluate students' perception of dissection in a graduate-entry, problem-based learning-based medical curriculum. At the end of the musculoskeletal dissection program in second year, a Likert-type questionnaire was used to explore medical student perceptions of the perceived advantages and challenges of cadaveric dissections in comparison with other anatomy teaching methods. Overall, a majority of students had a positive perception of dissections. Students who attended dissections regularly had significantly more positive perceptions about their experience and were in agreement with statements such as "dissections make learning more interesting" and "I would be disadvantaged if I did not attend dissection classes." Non-regular attendance was associated with statements about dissections such as "I do not like the smell," "time consuming," and "bored with the way it is carried-out." A follow-up study after completion of the medical program revealed a significant improvement of positive perception about dissection. Student perceptions appear to favour a role for cadaveric dissection in learning anatomy in modern medical curricula. However, optimal and effective integration of dissections is important, with consideration given to its structure and extent of content weighed against logistics and availability of resources; while addressing negative perceptions of dissection-based teaching.

Dependent heroin use and associated risky behaviour: the role of rash impulsiveness and reward sensitivity.

Impulsive temperament has long been considered as a risk factor for substance use disorders (SUD). Considering the heterogeneity of impulsivity, a biologically-based 2-factor model incorporating reward sensitivity and rash impulsiveness facets, has been proposed. Here we report how these two facets of impulsiveness could be associated with different aspects of dependent heroin use and associated risky behaviour. Two hundred and ninety three dependent heroin users and 232 non-users were assessed on reward sensitivity, rash impulsivity, and the related trait of punishment sensitivity. After adjusting for multiple comparisons, heroin users were found to be more rash-impulsive and reward-sensitive than non-users (p<0.001). Within users, rash impulsivity was associated with high risk behaviour including escalating heroin consumption, injecting heroin use, hazardous drinking, low treatment-seeking and risky sexual behaviour. Reward sensitivity was uniquely associated with early onset of drug use. While greater impulsivity is a common trait in drug users compared with non-users, the use of a 2-factor model of impulsivity provides additional information regarding specific aspects of drug initiation and maintenance that can be targeted in the prevention and treatment of heroin dependence.

Patterns of substance use in male incarcerated drug users in Sri Lanka.

INTRODUCTION AND AIMS: The number of illicit drug users incarcerated in Sri Lanka has been growing over the last decade. This paper presents drug-use characteristics and risk-taking behaviours among a group of male incarcerated drug users. DESIGN AND METHODS: An interviewer-administered structured questionnaire was completed by 278 drug users in three prisons in Sri Lanka. RESULTS: The majority (81.3%) of interviewees were aged 25-45 years. Most of them had received low levels of education, and experienced childhood delinquency and a deprived upbringing. Drug use was largely initiated during early adolescence, then continued to chronicity and the development of drug dependence. There was a high incidence (25-35%) of family history of drug abuse. Heroin (98%) and cannabis (54%) were the main drugs of abuse in the past 30 days. Polydrug use was common (75% in the past 12 months). Tobacco and alcohol use were widespread. The prevalence of intravenous drug use was higher than officially reported (15.8% vs. 1%). There was a high prevalence (53%) of risk-taking sexual behaviour. DISCUSSION AND CONCLUSION: The pattern of drug use was similar to those reported in nearby countries. However, the increasing prevalence of injecting drug use and risk-taking sexual behaviour is a concern. There is an urgent need to develop effective treatment strategies and to prevent the spread of HIV and hepatitis in Sri Lanka.