PubMed Health⌕ Search

Biomedical subjects

G C Ooi

Publications and source records attributed to G C Ooi.

At least 19 recordsLinked to original sources
PubMed2004

Magnetic resonance screening of iron status in transfusion-dependent beta-thalassaemia patients.

The clinical utility of dual sequence (T1- and T2-weighted) magnetic resonance (MR) imaging in estimating liver iron concentration (LIC) in 32 transfusion-dependent beta-thalassaemia major (24 females; age 18.5+/-5.9 years) patients on desferrioxamine was evaluated. Signal intensity ratios (SIR) between liver, spleen and pancreas to psoas muscle were determined on both sequences. Relationships between clinical and MR parameters, and accuracy of SIR thresholds in determining adequacy of chelation from LIC were analysed. Liver T1- and T2-SIR were related to LIC (P < 0.001). T1-SIR < 0.60 predicted severe iron overload (LIC > 15 mg/g) with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 100%, 87%, 33% and 100% respectively. T2-SIR < 0.1 yielded 100% sensitivity, 93% specificity, 50% PPV and 100% NPV. T1-SIR > or = 1.1 predicted LIC < 7 mg/g with 69% sensitivity, 88% specificity, 85% PPV and 74% NPV. T2-SIR > or = 0.20 yielded 56.5% sensitivity, 94% specificity, 90% PPV and 71% NPV. LIC correlated with liver T1-SIR, liver T2-SIR and serum ferritin (r = -0.76, -0.65, 0.47, respectively; P < 0.01). Serum ferritin was inversely related to liver T1-SIR, liver T2-SIR and spleen T2-SIR (r = -0.35, -0.43, -0.40, respectively; P < 0.05). Mean total transfusion burden was not related to any MR parameter. Although neither MR sequence was a highly accurate predictor of LIC, SIR thresholds are useful to determine presence of iron overload and adequacy of chelation treatment.

Adolescent↗
PubMed2004

Mucosa-associated lymphoid tissue (MALT) lymphoma of the jejunum: an elusive cause of recurrent upper gastrointestinal bleeding.

MALT lymphoma often involves the stomach but much less commonly the small bowel. We present clinico-pathologic and radiologic features of a patient with recurrent gastrointestinal bleeding due to MALT lymphoma of the jejunum. Because of the small bowel location, the source of bleeding has been elusive, resulting in delayed diagnosis. The diagnosis was based on the small B cell morphology, demonstration of lympho-epithelial lesions, and immunophenotypic profile.

Abdomen↗
PubMed2004

Chronic myeloid leukemia in an adolescent with Ollier's disease after intensive X-ray exposure.

We report a 19-year-old man with Ollier's disease with multiple orthopedic procedures performed for leg length discrepancy; who developed chronic myeloid leukemia presenting with intramuscular hematoma. His symptoms resolved with cytoreductive treatment by hydroxyurea. Cytogenetic and molecular investigations showed a complex Philadelphia translocation t(9;22;13) (q34;q11.2;q12), with predominance of ela2 BCR/ABL splicing and deletion of reciprocal der(9) ABL/BCR locus, all suggesting poor prognosis. The cumulative X-ray exposure from repeated operations from the age of 7 to 12 years was estimated to be around 16 mSv, approximately the dose of 720 chest X rays. Literature review showed two other cases of leukemia occurring in patients with multiple enchondromatosis. Although the development of CML in this young patient might be related partly to genetic defects, the repeated radiation exposure, especially at young age and directly on the marrow tissue in the long bones, might also be an important pathogenetic factor.

Adult↗
PubMed2004

Primary granulocytic sarcoma of the mediastinum.

Primary granulocytic sarcoma (GS) is rare, and poses a diagnostic pitfall for both pathologists and oncologists. Previous literature showed that almost half of the patients with primary GS were misdiagnosed initially. We presented the clinico-pathological and radiological features of a patient with primary mediastinal GS, and discussed the differential diagnoses and clinical management.

Adult↗
PubMed2004

Primary follicular lymphoma of the small intestine.

While nodal follicular lymphoma is prevalent in western countries, primary extranodal presentation is rare. We present the clinico-pathological and radiologic features of a patient with primary follicular lymphoma of the small intestine presenting with intestinal obstruction. This is followed by the discussion on the frequency and staging systems for primary gastrointestinal lymphomas, and the relevance of monoclonal anti-CD20 antibody therapy.

Aged↗
PubMed2004

Advances in imaging of the solitary pulmonary nodule.

OBJECTIVE: To review the radiological management of a solitary pulmonary nodule. DATA SOURCES: MEDLINE literature search (1958-2002). STUDY SELECTION: All review articles and original articles. Key words for the literature search were 'solitary pulmonary nodule' and 'imaging'. DATA EXTRACTION: All relevant information and data. DATA SYNTHESIS: The solitary pulmonary nodule remains a perennial problem in radiological practice, particularly with current trends using low-dose computed tomography to screen for lung cancer. Determining the likelihood of malignancy forms the basis of the radiological approach of a solitary pulmonary nodule. Several factors that influence risk analysis include morphological and enhancement characteristics of the solitary pulmonary nodule on imaging, stability of the nodule, age of patient, smoking history, and history of malignant disease. Other ancillary procedures and imaging techniques that assist in the evaluation of a solitary pulmonary nodule include fluorodeoxyglucose positron-emission tomography, technetium Tc 99m depreotide imaging, bronchoscopy with bronchioloalveolar lavage and biopsy, image-guided transthoracic needle aspiration biopsy, video-assisted thorascopic surgery, and thoracotomy. CONCLUSIONS: The success of any radiological management of a solitary pulmonary nodule rests on careful clinical evaluation and risk stratification for malignancy before the implementation of appropriate imaging techniques.

Adult↗
PubMed2004

A case of cerebellar hypoplasia in a Chinese infant with osteogenesis imperfecta.

We report a unique case of unilateral cerebellar hypoplasia in a young Chinese girl with osteogenesis imperfecta type IV. Magnetic resonance imaging showed mild basilar invagination and impression. Although unilateral cerebellar hypoplasia and osteogenesis imperfecta may have been coincidental diagnoses, we propose possible mechanisms for unilateral cerebellar hypoplasia secondary to osteogenesis imperfecta. For example, cerebellar hypoplasia may have been because of vascular disruption or direct compression to the posterior circulation in utero. Foetuses with osteogenesis imperfecta are more susceptible to the above risks compared to the normal foetus because of associated craniocervical anomalies and a poorly ossified skull.

Asian People↗
PubMed2004

Lymphoepithelioma-like carcinoma of the lung: experience with ten cases.

OBJECTIVE: Lymphoepithelioma-like carcinoma of the lung (LELC) is a rare form of non-small cell lung cancer predominantly affecting young non-smoking Asians, and there has been only limited experience in its palliative chemotherapy and radiotherapy. We investigated tumour response, time to progression and survival of LELC patients who received such treatment. DESIGN: We prospectively recruited patients with confirmed advanced LELC who were treated with chemoradiotherapy in our unit, a regional tertiary referral centre for lung cancer treatment. RESULTS: There were 10 patients (five males, age 47 +/- 9.8 years, median follow-up 22 months) with advanced LELC (respectively 1, 4, and 5 patients at TNM stage IIIA, IIIB and IV) who received systemic chemotherapy and radiotherapy. The primary chemotherapy regimen consisted of 5-fluorouracil/leucovorin/cisplatin. The response rates to 5-fluorouracil/leucovorin/cisplatin were 60% partial response, 10% stable disease, and 30% progressive disease. Eight patients were also given local radiotherapy. Five patients received salvage chemotherapy when disease progressed after primary chemotherapy. The overall median survival was 23.4 +/- 4.7 months. CONCLUSION: The encouraging response to combination chemotherapy with 5-fluorouracil/leucovorin/ cisplatin, although empirical, supports its use with radiotherapy in unresectable lymphoepithelioma-like carcinoma of the lung.

Adult↗
PubMed2003

Treatment of lymphoma relapses after allogeneic hematopoietic stem cell transplantation with intensive chemotherapy followed by infusion of hematopoietic stem cell from the original donor.

Five lymphoma patients relapsed from allogeneic hematopoietic stem cell transplantation (HSCT). Three patients who received myeloablative conditioning had full donor chimerism at relapse, whereas two who received nonmyeloablative conditioning had partially or completely lost the graft. All received mini-BEAM [carmustine (BCNU), etoposide, cytarabine (AraC), melphalan], followed by infusion of HSC (four peripheral blood, one marrow) from the initial donor. Neutropenia and thrombocytopenia were brief, and full donor chimerism was established in all cases. There were four complete and one partial remissions. Graft-versus-host disease occurred in three cases, all with full donor chimerism at relapse. Two patients died subsequently of disease relapse or progression. Another two patients died from fungal infection, one of whom was still in remission at death. One patient had remained in remission 47 months after treatment. Mini-BEAM/HSC is an effective treatment for lymphoma relapses after allogeneic HSCT, but optimal strategies of remission consolidation and prevention of treatment-related complications are needed to improve outcome.

Adult↗
PubMed2003

Factors predictive of 5-year survival after transarterial chemoembolization for inoperable hepatocellular carcinoma.

BACKGROUND: Transarterial chemoembolization (TACE) is widely used for unresectable hepatocellular carcinoma (HCC), but the long-term survival benefit remains unclear. METHODS: Pretreatment variables were analysed for factors predictive of actual 5-year survival from a prospective database of patients with inoperable HCC treated by TACE between 1989 and 1996. RESULTS: Complete 5-year follow-up (median 91 months) was obtained for 320 patients who underwent a median of 4 (range 1-41) TACEs. Median tumour size was 9 (range 1-28) cm. There were 25 5-year survivors (8 per cent), including eight with tumours larger than 10 cm in diameter and three with portal vein branch involvement. On univariate analysis, female gender (P = 0.037), absence of ascites (P = 0.028), platelet count below 150 x10(9) per litre (P = 0.011), albumin concentration greater than 35 g/l (P = 0.04), alpha-fetoprotein level below 1000 ng/ml (P = 0.007), unilobar tumour (P = 0.027), fewer than three tumours (P = 0.015), absence of venous invasion (P = 0.011), and tumour diameter less than 8 cm (P = 0.021) were significant predictors of 5-year survival. Albumin concentration greater than 35 g/l (P = 0.011), unilobar tumour (P = 0.012) and alpha-fetoprotein level below 1000 ng/ml (P = 0.014) were independent prognostic factors on multivariate analysis. CONCLUSION: Five-year survival is possible with TACE for inoperable HCC, even in some patients with advanced tumours. Unilobar tumours, alpha-fetoprotein level below 1000 ng/ml and albumin concentration greater than 35 g/l were factors predictive of 5-year survival.

Adult↗
PubMed2003

MRI of neonatal encephalopathy.

We present the magnetic resonance imaging (MRI) findings in neonatal encephalopathy, including hypoxic-ischaemic encephalopathy, perinatal/neonatal stroke, metabolic encephalopathy from inborn errors of metabolism, congenital central nervous system infections and birth trauma. The applications of advanced MRI techniques, such as diffusion-weighted imaging and magnetic resonance spectroscopy are emphasized.

Birth Injuries↗
PubMed2003

Down-regulation of aquaporin 3 in bronchiectatic airways in vivo.

Bronchiectasis is characterized pathologically by permanent abnormal bronchial dilation, and clinically by chronic sputum production. Aquaporin 3 (AQP3), a recently described water channel that is also found in large airway cell membrane, could play a role in the pathogenesis and particularly that of bronchorrhea in bronchiectasis. However, little is known of its in vivo distribution and physiological role in human airways. We have, therefore, performed this quantitative immunohistochemistry study on endobronchial biopsies to evaluate the expression and clinical relevance of AQP3 in patients with idiopathic bronchiectasis (n = 25, 15 F, 64.3 +/- 11.5 years) and control subjects (n = 14, 5 F, 57.5 +/- 12.0 years). Quantitative image analysis was performed to evaluate the expression of AQP3 in the bronchial epithelial cells. Our results show that AQP3 was predominantly expressed in the basal cells of the epithelial layer in both groups. Expression of AQP3 was significantly reduced in the basal, but not columnar, epithelial cells in bronchiectasis compared with control airways (p = 0.02, 0.35). Only bronchiectatic patients with regular sputum production, but not their counterparts, had significant downregulation of epithelial AQP3 expression compared with control airways (p = 0.004, 0.24). Our findings suggest that AQP3 could have an important role in the pathogenesis of increased mucus production in bronchiectasis.

Aquaporin 3↗
PubMed2003

Coriolus versicolor polysaccharide peptide slows progression of advanced non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a leading cause of cancer deaths, and over 60% of patients present with advanced stages. Although polysaccharide peptides (PSP), isolated from the fungus Coriolus versicolor, have been reported to have anti-tumor effects, its clinical efficacy has not been properly evaluated. METHODS: Double-blind placebo-controlled randomized study to evaluate the effects of 28-day administration of PSP (Windsor Pharmaceutical, Hong Kong) on patients, who had completed conventional treatment for advanced NSCLC. RESULTS: Thirty-four patients, with no significant difference in their baseline demographic, clinical or tumor characteristics, or previous treatment regimes (P>0.05) were recruited into each of the PSP and control arms. After 28-day treatment, there was a significant improvement in blood leukocyte and neutrophil counts, serum IgG and IgM, and percent of body fat among the PSP, but not the control, patients (P<0.05). Although the evaluable PSP patients did not improve in NSCLC-related symptoms, there were significantly less PSP patients withdrawn due to disease progression, than their control counterparts (5.9 and 23.5%, respectively; P=0.04; OR 4.00). There was no reported adverse reaction attributable to the trial medications. CONCLUSION: PSP treatment appears to be associated with slower deterioration in patients with advanced NSCLC.

Adult↗