Richard Hift

Use of thiopurines in the treatment of inflammatory bowel disease is associated with an increased risk of non-melanoma skin cancer in an at-risk population: A cohort study

Background and Aim:  The thiopurines azathioprine and 6‐mercaptopurine are effective in the management of patients with inflammatory bowel disease (IBD) in whom aminosalicylates, antibiotics and corticosteroids have failed to induce or maintain remission. Long‐term use of these agents has been linked to a greatly increased risk of non‐melanoma skin cancer and lymphatic cancer in organ transplant recipients. There is some evidence to suggest that IBD patients receiving thiopurines might be at increased risk of cancer. Our aim was to determine the incidence of cancer in a cohort of patients with IBD managed in our clinic, and to relate this to thiopurine exposure.

Drugs in porphyria: From observation to a modern algorithm-based system for the prediction of porphyrogenicity.

The acute porphyrias are a group of disorders which result from inherited defects in the enzymes of the heme biosynthetic pathway. Affected patients are prone to potentially fatal acute attacks. These attacks are frequently precipitated by exposure to commonly used drugs. Correctly identifying the safety or otherwise of drugs in porphyria is therefore important. In this review we describe how clinical experience and the findings of experimental systems using whole animal or cell culture models have been interpreted to determine porphyrogenicity, that is the potential of a drug to induce an acute attack in a patient carrying a gene for acute porphyria. It is now well established that induction of delta-aminolevulinic acid synthase, the rate controlling enzyme of the heme biosynthetic pathway, is fundamental to porphyrogenicity, and that drug-induced hepatic heme depletion via induction or suicidal inactivation of cytochrome P450 is central to this process. The process is now sufficiently well understood that prediction of porphyrogenicity from structural and functional information alone would appear to be justified.

The spectrum of skin diseases in a black population in Durban, KwaZulu‐Natal, South Africa

Precise knowledge of the prevalence and spectrum of skin diseases in a population allows for effective planning for provision of dermatology services and distribution of resources. There are no published data on the epidemiology of skin disorders in Durban, KwaZulu‐Natal.

Should essays and other ? open-ended? -type questions retain a place in written summative assessment in clinical medicine?

BackgroundWritten assessments fall into two classes: constructed-response or open-ended questions, such as the essay and a number of variants of the short-answer question, and selected-response or closed-ended questions; typically in the form of multiple-choice. It is widely believed that constructed response written questions test higher order cognitive processes in a manner that multiple-choice questions cannot, and consequently have higher validity.DiscussionAn extensive review of the literature suggests that in summative assessment neither premise is evidence-based. Well-structured open-ended and multiple-choice questions appear equivalent in their ability to assess higher cognitive functions, and performance in multiple-choice assessments may correlate more highly than the open-ended format with competence demonstrated in clinical practice following graduation. Studies of construct validity suggest that both formats measure essentially the same dimension, at least in mathematics, the physical sciences, biology and medicine. The persistence of the open-ended format in summative assessment may be due to the intuitive appeal of the belief that synthesising an answer to an open-ended question must be both more cognitively taxing and similar to actual experience than is selecting a correct response. I suggest that cognitive-constructivist learning theory would predict that a well-constructed context-rich multiple-choice item represents a complex problem-solving exercise which activates a sequence of cognitive processes which closely parallel those required in clinical practice, hence explaining the high validity of the multiple-choice format.SummaryThe evidence does not support the proposition that the open-ended assessment format is superior to the multiple-choice format, at least in exit-level summative assessment, in terms of either its ability to test higher-order cognitive functioning or its validity. This is explicable using a theory of mental models, which might predict that the multiple-choice format will have higher validity, a statement for which some empiric support exists. Given the superior reliability and cost-effectiveness of the multiple-choice format consideration should be given to phasing out open-ended format questions in summative assessment. Whether the same applies to non-exit-level assessment and formative assessment is a question which remains to be answered; particularly in terms of the educational effect of testing, an area which deserves intensive study.

Women's perceptions of the benefits and risks of skin-lightening creams in two South African communities

Skin‐lightening products are commonly used by black communities in South Africa and worldwide. This practice has deep historical and cultural roots and is associated with adverse cutaneous effects.

Fifty years of porphyria at the University of Cape Town

The porphyrias are a group of disorders resulting from defective haem biosynthesis. One form, variegate porphyria, is common in South Africa as a result of a founder effect. Over the past 50 years, the University of Cape Town Faculty of Health Sciences has built and maintained an international reputation for excellence in the field of porphyria. The porphyria group is respected for its research and for its accumulated experience in the management of these disorders. Equally important has been the comprehensive and holistic care offered to patients with porphyria, and to their families.

South African medical schools: Current state of selection criteria and medical students’ demographic profile

BACKGROUND Selection of medical students at South African (SA) medical schools must promote equitable and fair access to students from all population groups, while ensuring optimal student throughput and success, and training future healthcare practitioners who will fulfil the needs of the local society. In keeping with international practices, a variety of academic and non-academic measures are used to select applicants for medical training programmes in SA medical schools. OBJECTIVES To provide an overview of the selection procedures used by all eight medical schools in SA, and the student demographics (race and gender) at these medical schools, and to determine to what extent collective practices are achieving the goals of student diversity and inclusivity. METHODS A retrospective, quantitative, descriptive study design was used. All eight medical schools in SA provided information regarding selection criteria, selection procedures, and student demographics (race and gender). Descriptive analysis of data was done by calculating frequencies and percentages of the variables measured. RESULTS Medical schools in SA make use of academic and non-academic criteria in their selection processes. The latter include indices of socioeconomic disadvantage. Most undergraduate medical students in SA are black (38.7%), followed by white (33.0%), coloured (13.4%) and Indian/Asian (13.6%). The majority of students are female (62.2%). The number of black students is still proportionately lower than in the general population, while other groups are overrepresented. CONCLUSION Selection policies for undergraduate medical programmes aimed at redress should be continued and further refined, along with the provision of support to ensure student success.

Prevalence of breast tuberculosis: Retrospective analysis of 65 patients attending a tertiary hospital in Durban, South Africa

BACKGROUND Breast tuberculosis (BTB) is uncommon, but not rare. Knowledge of the ways in which it can present can prevent unnecessary invasive procedures and delay in diagnosis. OBJECTIVES To describe the clinical and radiological findings in patients with BTB, including evaluation of current treatment methods. METHODS We retrospectively analysed 65 patients diagnosed with BTB at Addington and King Edward VIII hospitals, Durban, South Africa, between 2000 and 2013. Demographic, clinical and radiological findings and treatment outcomes were noted. RESULTS A total of 11,092 patients underwent breast investigations between 2009 and 2013, with a prevalence of BTB for the period of 0.3% (30 patients). Of the 65 patients diagnosed between 2000 and 2013, 64 were female (98.5%) and one was male (1.5%). The age range was 23-69 years (mean 38.5). The most common mammographic pattern was density (39.4%) and the least common a mass (6.1%). Isolated axillary lymphadenitis was found in 12.1%. Abscess was the commonest ultrasound pattern (39.0%). Of the 47 patients with a known history of pulmonary tuberculosis (TB), 68.1% (n=32) did not have radiological evidence of previous or concurrent pulmonary TB, nor was there evidence of TB elsewhere. Of 47 patients with known HIV status, 34 were HIV-positive. Fine-needle aspiration cytology had sensitivity of only 28% compared with 94% for histology. Of those treated, 72.7% obtained full resolution following 9 months of TB treatment; 25.0% did not complete treatment, and 2.3% (n=1) died while on treatment. Follow-up data on relapse rates after treatment completion and disease resolution are scanty. CONCLUSION Understanding and being aware of the various presentations of BTB make it possible to treat most patients successfully.

Iron homeostasis in porphyria cutanea tarda: mutation analysis of promoter regions of CP, CYBRD1, HAMP and SLC40A1

Mutations in the UROD gene are demonstrable in approximately only one quarter of all familial porphyria cutanea tarda (PCT) cases with a typical 50% decrease in the catalytic activity of hepatic UROD.1 In the remaining 75% of cases, there is no underlying mutation in the UROD gene, and the disease results from an acquired inhibition of hepatic UROD, referred to as sporadic PCT. Of importance is a near-universal association between PCT and raised hepatic iron concentrations. Most patients with PCT will have evidence of direct or indirect iron overload, and PCT appears not to develop in the absence of adequate iron stores.1 ,2 Iron alone is insufficient for the precipitation of PCT. It is, however, clear that a complex gene-chemical-environmental interaction is pivotal to the process.2 Our study focused on the regulatory (promoter) regions of four genes that play a significant role in iron homeostasis: ceruloplasmin ( CP ), cytochrome b reductase 1 ( CYBRD1 ), hepcidin antimicrobial peptide ( HAMP ) and solute carrier family 40 member A1 ( SLC40A1 ). ### Study cohort Blood samples were collected from 74 unrelated South African patients (39 male, 35 female) who presented with clinically expressed PCT. Ethnically, the study group included 15 indigenous African patients, eight males (mean age of onset: 49.88±21 years), seven females …

A retrospective analysis of electrocardiographic abnormalities found in black South African patients with diabetes attending a regional hospital in KwaZulu- Natal

Objectives: Diabetes mellitus increases the risk of coronary heart disease and myocardial infarction (MI). Silent MI occurs with greater frequency in patients with diabetes with or without autonomic neuropathy and carries a similar prognosis to overt MI. Regular electrocardiographic (ECG) assessment is integral in the chronic management of patients with diabetes. Limited data exist on the spectrum of ECG abnormalities of black South African patients with diabetes. The primary aim of this study was a description of ECG abnormalities found and the secondary aim was the determination of factors associated with left ventricular hypertrophy (LVH) and MI. Setting and participants: The study was carried out at a regional hospital diabetes clinic in Pietermaritzburg, KwaZulu-Natal. The initial ECGs performed on patients from October 1, 2012 to September 30, 2014 were analysed. The first ECGs of 637 black South African patients with diabetes were studied, representing 80.1% of all eligible patients. Results: The major ECG abnormalities detected were those suggestive of LVH (36.0%), MI (21.7%), conduction defects (17.7%), T-wave inversion (14.1%) and ventricular ectopics (6.8%). Most infarctions were silent (89.8%), and affected the inferior territory significantly more than anterior, lateral and antero-lateral territories (52.9% vs. 33.3% vs. 9.4% vs. 1. 5%, respectively). A substantial percentage of patients with MI failed to achieve target HbA1c and triglyceride levels and waist-to-height-ratios. Diet, exercise and self-monitoring of glucose were all associated with positive effects on both MI and LVH. A greater percentage of patients with LVH had evidence of MI versus those without hypertrophy (28.4% vs. 19.4%). Conclusion: This study demonstrates a high prevalence of undiagnosed MI within this cohort of South African patients with diabetes. Patients with LVH were more prone to infarction. Poor glycaemic and triglyceride control and obesity were associated with infarction. Improving glycaemic and lipid control together with lifestyle modification may help prevent macrovascular cardiac complications.