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Biomedical subjects

A K Lim

Publications and source records attributed to A K Lim.

13 recordsLinked to original sources

Radiology of gestational trophoblastic neoplasia.

Gestational trophoblastic neoplasia (GTN) encompasses a broad spectrum of placental lesions from the pre-malignant hydatidiform mole (complete and partial) through to the malignant invasive mole, choriocarcinoma and rare placental site trophoblastic tumour (PSTT). Ultrasound remains the radiological investigation of choice for initial diagnosis, and it can also predict invasive and recurrent disease. Magnetic resonance imaging is of invaluable use in assessing extra-uterine tumour spread, tumour vascularity, and overall staging. Positron emission tomography and computed tomography undoubtedly have a role in recurrent and metastatic disease, while angiography has a place in disease and complication management. This review will describe the relevant pathophysiology and natural history of GTN, and the use of imaging techniques in the diagnosis and management of these conditions.

Female↗

A practical and reliable method for measuring ethane and pentane in expired air from humans.

We describe a method for the collection of expired air and further document the performance of our analytical technique that is used to measure ethane and pentane simultaneously. Four minutes of breathing hydrocarbon-free air before collection effectively removed high concentrations of residual ambient ethane and pentane from the lungs, with washout times up to 30 min resulting in no further reductions in breath hydrocarbons. Mean (+/-SE) exhalation rates (pmol/kg b.wt./min) in 11 subjects were 2.4 +/- 0.6 for ethane and 1.5 +/- 1.3 for pentane. Total intraindividual variability in exhalation rates (as percent coefficient of variation, %CV), measured from 4 subjects on at least 6 different days, was greater for pentane (44% CV) than for ethane (29% CV). Analytical variability contributed 6% to the total %CV. Advantages of the method are described, and reasons for the large variability in values reported in the literature are discussed.

Adult↗

Measurement of serum TSH in the investigation of patients presenting with thyroid enlargement.

In otherwise euthyroid patients presenting with thyroid enlargement, reduction in serum thyrotrophin (TSH) concentrations measured in a sensitive assay may be a marker of thyroid autonomy and may therefore indicate a benign underlying pathology. We investigated prospectively a cohort of 467 subjects presenting consecutively to our thyroid clinic with nodular or diffuse enlargement of the thyroid. Subjects were divided into those with normal (0.4-5.5 mU/l), low but detectable (0.1-0.39 mU/l) or undetectable (< 0.1 mU/l) serum TSH concentrations. The final pathological diagnosis was defined by fine-needle aspiration cytology and clinical follow-up of at least 2 years or by fine-needle aspiration cytology and histology following surgical treatment. Serum TSH concentrations below normal were found in 75 patients (16.1%), those with low serum TSH results having higher mean free T4 concentrations, were older and were more likely to be female. In those with undetectable serum TSH, no patient had a diagnosis of thyroid neoplasia and in those with low but detectable TSH, thyroid neoplasms were diagnosed in two patients (3.4%). In those with normal serum TSH, 12.0% had a final diagnosis of thyroid neoplasm (p = 0.013). Overall, thyroid malignancy was found in one patient (1.3%) of those with a serum TSH measurement below the normal range and 6.9% of those with normal serum TSH (p < 0.06). Reduction in serum TSH at presentation may identify a group which requires less intensive investigation and follow-up than those without biochemical evidence of thyroid autonomy.

Biomarkers↗

Pilot study of formestane in postmenopausal women with breast cancer.

A pilot study of Formestane or 4-Hydroxyandrostenedione (Lentaron), a new endocrine agent, was conducted on 18 postmenopausal patients with locally advanced and metastatic breast cancer. 16 patients were evaluable for response and objective responses were seen in 4 patients (25%). Stabilisation of disease was seen in 5 patients (32%). Out of 17 patients evaluable for toxicity, 3 (18%) reported adverse effects including hot flushes, lethargy and myalgia. Adverse effects were mild, transient and no patient required discontinuation of drug. Our study confirms that Formestane is a well tolerated endocrine agent with low toxicity and reasonable efficacy in postmenopausal patients with locally advanced and metastatic breast cancer.

Aged↗

Adjuvant chemotherapy for colorectal cancer: a Malaysian experience.

This study aims to evaluate the practice of adjuvant chemotherapy in colorectal cancer at the Institute of Radiotherapy and Oncology, Hospital Kuala Lumpur. A retrospective analysis of 320 patients' records from 1986 to 1994 was carried out. Adjuvant chemotherapy was given to 98 patients. Cancers of the rectum and sigmoid colon constituted over 60% of the patients. All the regimes used were 5-fluorouracil-based. The oral route was the most commonly used (55.1%). Toxicity was seldom the reason for stopping treatment (2%). The adjuvant treatment employed has been tolerable while the survival was comparable with other centres.

Adolescent↗

Ondansetron against metoclopramide/dexamethasone--a comparative study.

This trial was carried out in Hospital Kuala Lumpur. Fifty-two patients who were scheduled to receive their first or subsequent courses of cancer chemotherapy with single dose cisplatinum containing chemotherapy regimens were evaluated. Thirty-four patients were given ondansetron in one group while 18 in the other group received metoclopramide with dexamethasone. The response to treatment was categorised as complete (0 emetic episode), major (1 or 2 emetic episodes), minor (3 to 5 emetic episodes) or failure (> 5 emetic episodes or rescue medication). Among the 52 patients, a complete or major control (0 to 2 emetic episodes) was achieved in 23/34 patients (68%) from the ondansetron group and in 3/18 patients (17%) from the metoclopramide with dexamethasone group (p < 0.002) on day 1. Similarly, the control of nausea was greater in the ondansetron group compared with the metoclopramide with dexamethasone group (p < 0.0009) on day 1. Two patients were excluded (dropped out) after day one from each of the two study groups due to excessive vomiting subsequent to cisplatinum therapy. From days 2 to 6, there was a trend in favour of ondansetron. Both treatments were well tolerated. The results of this trial show that in the prophylaxis of nausea and vomiting induced by cisplatinum containing chemotherapy, the efficacy of ondansetron is superior to that of a standard anti-emetic combination, metoclopramide with dexamethasone.

Adult↗

A multivariate analysis of factors predictive of parenteral nutrition-related cholestasis (TPN cholestasis) in VLBW infants.

To identify the factors predictive of development of TPN-related cholestasis, we conducted a historical cohort analysis of 62 VLBW infants who received TPN of which 17 developed cholestasis (27.4%). In the cholestatic group, the mean duration of TPN administration was significantly longer (25.7 days vs 8 days, p less than 0.001), the maximum daily amino-acids and lipids in the TPN infusate was significantly higher (amino-acids 2.25 vs 1.25 gm/kg/day, p less than 0.001; lipids 2.0 gm/kg/day vs 1.25 gm/kg/day, p less than 0.01), the duration of fasting was significantly longer (20.7 days vs 6.3 days, p less than 0.001) and the incidence of necrotizing enterocolitis was significantly higher (58.8% vs 15.5%, p 0.02). Using a linear discriminant analysis model with development of cholestasis as the dependent variable, the duration of TPN (p 0.0000) and the maximum daily amino-acid in infusate (p 0.0000) were found to be independent variables predictive of development of cholestasis. This model may serve to identify VLBW infants who will develop cholestasis during TPN.

Amino Acids↗

Neutral proteinases from human blood cells.

1. Human erythrocytes essentially essentially uncontaminated by leukocytes retain considerable proteolytic activity in the membrane fraction. 2. The enzyme responsible has similar properties to previously-reported human erythrocyte membrane proteinases. 3. A particulate fraction from human leukocytes does not yield a similar enzyme when extracted and fractionated in the same way.

Chromatography, Gel↗