Virtual postgraduate exams and assessments: the challenges of online delivery and optimising performance

The COVID-19 pandemic has catalysed the computerisation and online delivery of postgraduate examinations. Social distancing regulations and lockdown measures resulted in many written and clinical examinations being cancelled during the initial surge of the virus. In an effort to reinstate the assessment of trainees and enable career progression, the UK medical regulator, the General Medical Council (GMC) has approved unprecedented changes to clinical examinations, including virtual assessment. We outline the changes made and the advantages and disadvantages of these new examination formats. We discuss ways for candidates and examiners to optimise their virtual environment and develop skills that can improve performance.     

Prevalence of Candida spp., xerostomia,and hyposalivation in oral lichen planus – A controlled study

Objective

To determine the frequency of Candida spp., xerostomia, and salivary flow rate (SFR) in three different groups: patients with OLP (OLP group), patients with oral mucosal lesions other than OLP (non‐OLP group), and subjects without oral mucosal lesions (control group).

Material and methods

Xerostomia as well as SFR was investigated in the three groups. Samples for isolation of Candida spp. were collected from OLP lesions (38 patients), non‐OLP lesions (28 patients), and healthy subjects (32 subjects).

Results

There was no statistically significant difference regarding the frequency of xerostomia and hyposalivation among the three groups (P > 0.05). A higher prevalence for colonization by Candida spp. was found in the healthy subject as compared to that of patients with OLP (P = 0.03) and non‐OLP (P = 0.02) groups. Low SFR was not a factor for colonization by Candida spp.

Conclusions

Xerostomia and hyposalivation occur with similar frequency in subjects with and without oral lesions; also, the presence of oral lesions does not increase the susceptibility to colonization by Candida spp. It seems that any study implicating Candida spp. in the malignant transformation of oral lesions should be carried out mostly on a biochemical basis, that is, by testing the capability of Candida spp. to produce carcinogenic enzyme.     

What are the effects of maternal and pre-adult environments on ageing in humans, and are there lessons from animal models?

An open issue in research on ageing is the extent to which responses to the environment during development can influence variability in life span in animals, and the health profile of the elderly in human populations. Both affluence and adversity in human societies have profound impacts on survivorship curves, and some of this effect may be traceable to effects in utero or in infancy. The Barker Hypothesis that links caloric restriction in very early life to disruptions of glucose-insulin metabolism in later life has attracted much attention, as well as some controversy, in medical circles. It is only rarely considered by evolutionary biologists working on phenotypic plasticity, or by biogerontologists studying model organisms such as C. elegans or Drosophila. One crucial mechanism by which animals can respond in an adaptive manner to adverse conditions, for example in nutrition or infection, during development is phenotypic plasticity. Here we begin with a discussion of adaptive plasticity in animals before asking what such phenomena may reveal of relevance to rates of ageing in animals, and in humans. We survey the evidence for effects on adult ageing of environmental conditions during development across mammalian and invertebrate model organisms, and ask whether evolutionary conserved mechanisms might be involved. We conclude that the Barker Hypothesis is poorly supported and argue that more work in human populations should be integrated with multi-disciplinary studies of ageing-related phenomena in experimental populations of different model species that are subjected to nutritional challenges or infections during pre-adult development.     

Targeted gene disruption of murine CD7

CD7 is a 40 kDa type I transmembrane glycoprotein member of the Ig superfamily. CD7 is a marker of mature human T cells and NK cells, and is expressed early in their development. Cross-linking CD7 positively modulates T cell and NK cell activity as measured by calcium fluxes, expression of adhesion molecules, cytokine secretion and proliferation. CD7 associates directly with phosphoinositol 3'-kinase, and CD7 ligation induces production of D-3 phosphoinositides and tyrosine phosphorylation. Severe combined immunodeficiency has been associated with a lack of lymphocyte surface CD7. The CD7 ligand is unknown. The murine CD7 homolog is encoded by a single gene on chromosome 11. In order to characterize the role of CD7 in lymphocyte development and function we have eliminated the CD7 gene by targeted disruption. CD7- deficient mice display normal histology of thymus and spleen, normal lymphocyte populations in primary and secondary lymphoid tissues, and normal serum Ig levels. Specific antibody responses after immunization with T-dependent and T-independent antigens are equivalent in wild-type and CD7 knockout mice. CD7-deficient lymphocytes respond normally to T cell mitogenic and allogeneic stimuli, and display normal NK cell cytotoxicity.      

Pneumothorax and other lung diseases: effect of altered resolution and edge enhancement on diagnosis with digitized radiographs

Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).