2005

W Lee, CL Ong, CCL Chong, WS Hwang
Correspondence: Dr Wickly Lee, wickly_lee@nni.com.sg

ABSTRACT
Introduction Omental infarction is a rare occurrence in the paediatric population. It often presents as an acute abdomen that can mimic acute appendicitis and cholecystitis.
Methods Six cases of omental infarction in children, proven on histopathology, were retrospectively reviewed for their clinical presentation and imaging findings on ultrasonography and computed tomography.
Results These cases revealed clinical and imaging findings on computed tomography that were suggestive and helpful in the pre-operative diagnosis of omental infarction. Findings on ultrasonography were less specific. Histopathological specimens revealed findings of vasculitis in all cases.
Conclusion There are clinical and imaging features that will help in the pre-operative diagnosis of this uncommon condition. We also postulate vasculitis as a possible underlying pathology for omental infarction.

Keywords: acute abdomen, computed tomography, omental infarction, ultrasonography, vasculitis
Singapore Med J 2005; 46(7): 328-332

A Eisenman, V Rusetski, D Avital, J Stolero, T Snitkovsky
Correspondence: Dr Arie Eisenman, eisenman@naharia.health.gov.il

ABSTRACT
Introduction Cardiac-specific troponins (cTn) are recently-introduced, sensitive and specific markers of myocardial injury, and their absence should allow to safely exclude a coronary event. Various assays are commercially available but the relative advantage of each is not clear. Our objective was to compare the reliability of the two most commonly used troponin assays (cTnI and cTnT), in the emergency department (ED) for clinical decision when myocardial infarction (MI) or acute coronary syndrome (ACS) is suspected.
Methods This prospective study included all patients arriving at the ED over a six-month period with chest pain or symptoms suggesting MI or ACS, in which diagnosis could not be confirmed due to absence of characteristic ECG features. All patients were tested with at least one of the two troponin assays available at the ED.
Results Of the 54 included patients, ten (19%) were eventually diagnosed with MI/ACS. Qualitative assays for cTnI and cTnT identified the MI/ACS patients by both assays (respective positive predictive values of 0.5 and 0.7, and negative predictive values of 1.0 and 0.9). However, these assays were only partially correlated (R equals 0.49) and differed significantly. The quantitative assay for cTnI, but not for cTnT, discerned those who had MI/ACS (group A) from those who had other condition (group B) by their troponin levels (MI/ACS - 17.2 plus or minus 23.8 ng/ml versus others - 0.37 plus or minus 0.91 ng/ml, p is less than 0.001).
Conclusion In the ED, bedside assays of troponins are invaluable tools for the clinician, and their use is cost-effective. However, in the recommended cutoffs levels, only troponin I but not troponin T allowed the safe discharge of patients not requiring acute hospital care.

Keywords: acute coronary syndrome, myocardial infarction, troponin I, troponin T
Singapore Med J 2005; 46(7): 325-327

M Mahboob, MF Rahman, P Grover
Correspondence: Dr Mohammed Mahboob, mahboob@ins.iictnet.com

ABSTRACT
Introduction The depletion of defensive body chemicals called antioxidants may increase the risk of complications from the most common form of diabetes mellitus. This study aims to evaluate blood serum lipid peroxidation product (malondialdehyde), an antioxidant, in non-insulin dependent male and female type 2 diabetic patients.
Methods Blood serum samples were collected from the diabetic patients and non-diabetic healthy controls. Malondialdehyde (MDA) level, which is an index of endogenous lipid peroxidation, reduced glutathione and protein content of the serum were estimated.
Results A significant elevation in MDA level and decrease in glutathione and protein content was observed in both male and female diabetic patients in comparison to non-diabetic controls.
Conclusion Our findings indicate that the increase in the lipid peroxidation product MDA and decline in glutathione-dependent antioxidant defences may appear early in non-insulin dependent type 2 diabetes mellitus patients before the development of secondary complications.

Keywords: antioxidant, diabetes mellitus, malondialdehyde, non-insulin dependent type 2 diabetes mellitus, oxidative stress
Singapore Med J 2005; 46(7): 322-324

HL Tey, SC Lim, AM Snodgrass
Correspondence: Dr Hong Liang Tey, teyhl@snail-mail.net

ABSTRACT
Refeeding oedema in patients with anorexia nervosa is a known but yet under-reported and poorly-understood condition. We illustrate this condition in a 19-year-old girl with anorexia nervosa who developed bipedal oedema after she was started on nutritional therapy. It is important to be aware of the differential diagnoses of oedema in such cases, which includes heart failure and previous diuretic abuse. Refeeding oedema generally resolves spontaneously but some individuals may require treatment.

Keywords: anorexia nervosa, eating disorder, oedema, refeeding oedema
Singapore Med J 2005; 46(6): 308-310

SCS Low, AK Sinha, FX Sundram
Correspondence: Dr Felix X Sundram, gnmfxs@sgh.com.sg

ABSTRACT
Carcinoma of the thyroid arising in an autonomously functioning or "hot" nodule is uncommon. The majority of thyroid carcinomas present as a "cold" nodule on radionuclide scintigraphy. We report a poorly-differentiated thyroid carcinoma developing in a long-standing "hot" nodule in a 51-year-old Chinese woman. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG PET) showed focal FDG uptake in the thyroid nodule, as well as in the cervical and pulmonary hilar lymph nodes. This case illustrates that the incidence of thyroid carcinoma in a "hot" nodule is not negligible. The role of FDG PET in the differentiation of benign from malignant thyroid nodules is still unclear. In contrast, FDG PET has been shown to have a role in the follow-up of thyroid cancer patients after thyroidectomy and subsequent radioactive iodine-131 (I-131) ablation. It may be useful in the identification and localisation of recurrent cancer foci in patients with elevated thyroglobulin levels but a negative I-131 whole body scan.

Keywords: positron emission tomography, radionuclide imaging, thyroid gland, thyroid neoplasm, thyroid nodule
Singapore Med J 2005; 46(6): 304-307