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
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-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
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-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.
•Three main mechanisms for heme induced colorectal carcinogenesis are discussed.•Heme cytotoxicity by accelerating programmed cell death and epithelial hyperplasia.•Heme induce lipid peroxidation and ...form DNA adducts and mutate APC gene.•Heme catalyses N-nitroso-compound production and genetic mutations.•Balanced diet reduces risk of heme induced colorectal carcinogenesis.
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.
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.
Abstract 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.
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.
► BIS/BAS scales were assessed as measures of fear, anxiety and behavioural approach. ► A five-factor solution with two BIS and three BAS factors was the best fitting model. ► However, overall model ...fit showed ill-fit to the data. ► Continued development of new measures for the revised theory is advocated.
Gray’s reinforcement sensitivity theory (RST) is one of the most influential contemporary theories of personality applied to the study of psychopathology. However, recent revisions to the theory have implications for known associations between personality vulnerabilities and psychopathology when using measures based on the original theory. A proposed re-structuring of a commonly used measure of the original RST, the BIS/BAS scales, as a proxy measure of the revised theory has met with some support in English-speaking countries. We sought to test the robustness of the new structure in a large non-English-speaking community sample (N=968) and a heroin-dependent sample (N=302). Results of exploratory and confirmatory factor analysis supported the proposed 5-factor solution comprising of two “BIS” factors (BIS-Anx and BIS-Fear) and three BAS factors (Drive, Reward responsiveness, Fun seeking) as the best fitting model for both community and heroin-dependent. However, this model showed considerable ill-fit in both samples. These findings support calls for the development of new measures consistent with the revised RST for use in applied research.
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.
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.
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.
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