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Biomedical subjects

K Y Wong

Publications and source records attributed to K Y Wong.

At least 19 recordsLinked to original sources
PubMed2007

The significance of LMO2 expression in the progression of prostate cancer.

LIM domain only 2 (LMO2) proteins are important regulators in determining cell fate and controlling cell growth and differentiation. This study has investigated LMO2 expression in human prostatic tissue specimens, prostate cancer cell lines, and xenografts; and has assessed the possible role and mechanism of LMO2 in prostate carcinogenesis. Immunohistochemical analysis on a tissue microarray consisting of 91 human prostate specimens, including normal, prostatic hyperplasia, high-grade prostatic intraepithelial neoplasia, and invasive carcinoma, revealed that overexpression of LMO2 was significantly associated with advanced tumour stage, as measured by Gleason score (p = 0.012), as well as with the development of distant metastasis (p = 0.018). These data were supported by quantitative real-time PCR experiments, where LMO2 mRNA levels were found to be significantly higher in prostate tumour specimen than in normal epithelium (p = 0.037). The expression of LMO2 in cell lines and xenografts representing androgen-dependent (AD) and androgen-independent (AI) prostate cancer stages was further studied. Consistent with the in vivo data, LMO2 mRNA and protein were found to be overexpressed in the more aggressive AI cells (PC3, DU145, and AI CWR22 xenografts) compared with less aggressive AD cells (LNCaP and AD CWR22 xenografts). Furthermore, stable introduction of LMO2 into LNCaP cells conferred enhanced cell motility and invasiveness in vitro, accompanied by down-regulation of E-cadherin expression. Taken together, these findings provide the first evidence to support the hypothesis that LMO2 may play an important role in prostate cancer progression, possibly via repression of E-cadherin expression.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Thermal stability of cubic boron nitride films deposited by chemical vapor deposition.

Thermal stability of well-crystallized cubic boron nitride (cBN) films grown by chemical vapor deposition has been investigated by cathodoluminescence (CL), Raman spectroscopy, and scanning electron microscopy (SEM) with the cBN films annealed at various temperatures up to 1,300 degrees C. The crystallinity of the cBN films further improves, as indicated by a reduction of the relevant Raman line width, when the annealing temperature exceeds 1,100 degrees C. Structural damage or amorphization was observed on the grain boundaries of the cBN crystals when annealing temperature reaches 1,300 degrees C. The CL spectra are found to be unchanged up to 1,100 degrees C after annealing at 500 degrees C, showing the stability of the cBN films in electronic properties up to this temperature. New features were observed in the CL spectra when annealing temperature reaches 1,200-1,300 degrees C.

Journal Article↗
PubMed2006

Exhaled nitric oxide levels are not correlated with eczema severity in Chinese children with atopic dermatitis.

Asthma is a common atopic disease associated with atopic dermatitis (AD) and allergic rhinitis (AR). Exhaled nitric oxide level (eNO) has been found to be an interesting noninvasive marker of disease severity in children with asthma. However, it is uncertain if eNO may be confounded by any coexisting AD or AR. In this study, eNO in Chinese children with moderate-to-severe AD and no asthma symptoms (n = 53) was measured online by a chemiluminescence analyzer. Severity of AD was assessed using the objective SCORing-Atopic-Dermatitis score and coexisting allergic rhinitis with the Allergic-Rhinitis-Score (ARS). Patients with active symptoms of asthma or inhaled/intranasal corticosteroids were excluded. There was no difference in eNO between genders and no correlation between eNO and AD severity regardless of ARS or bronchial reactivity status. ENO appears to be a noninvasive marker whose level is independent of the two atopic diseases of AD and AR in children old enough to perform exhalation maneuver.

Adolescent↗
PubMed2005

Study of intermolecular interactions in liquid nitrobenzene by depolarized hyper-Rayleigh scattering.

We employed depolarized hyper-Rayleigh scattering (HRS) to investigate the intermolecular interactions in liquid nitrobenzene. By comparing the depolarization ratios of the second-harmonic scattered light from neat nitrobenzene and mixtures of nitrobenzene and methanol of varying mixing ratios, we demonstrated the existence of a coherent component of HRS in liquid nitrobenzene. The coherent component was found to essentially disappear at a sufficiently high dilution of the nitrobenzene liquid. We also observed that both localized orientational correlation and delocalized libron excitation contribute to coherent HRS in liquid nitrobenzene. The delocalized contribution to coherent HRS was found to diminish much more readily with the introduction of interstitial foreign molecules than the localized contribution.

Journal Article↗
PubMed2005

An evidence base for International Health Regulations: quantitative measurement of the impacts of epidemic disease on international trade.

When cholera broke out in Mozambique, Kenya, Tanzania and Uganda in 1997, an urgent measure was filed with the Sanitary and Phytosanitary Committee of the World Trade Organization, by the European Union, citing the protection of human health, to limit imports of fish products. The authors analysed import data on specified products over time to quantify the trade impact of this measure. Using previous specific trade trends, the authors modelled expected trade flows and compared observed imports with expected imports to calculate the potential cost of lost trade. The conclusion of this analysis was that the impact of European restrictions on fish exports from Mozambique, Kenya, Tanzania and Uganda on the economies of these African countries was at least US dollar 332,217,415 for the years 1998 to 2002. Insights from such quantitative studies will be important in making policy choices under the revised International Health Regulations of the World Health Organization and should inform the discussion about the adoption of these regulations.

Animals↗
PubMed2004

Transformation of diffuse large B-cell lymphoma into pre-B acute lymphoblastic leukemia: clinicopathologic features and clonal relationship.

A patient with fibrosing alveolitis developed a diffuse large B-cell (DLBC) lymphoma that expressed CD20 and CD30. After an initial response, the lymphoma relapsed and was salvaged with further chemotherapy. After another remission of 3 years, a pre-B-cell acute lymphoblastic leukemia (ALL), which expressed CD10, CD19, CD22, CD79a, CD34 and terminal deoxyribonucleotidyl transferase, developed and led to death. Molecular analysis of the immunoglobulin heavy-chain gene showed that the initial lymphoma and its relapse were clonally related. At leukemic relapse, 2 clones related to the initial and relapsed lymphoma clones were present. DLBC lymphomas arise from post-follicle center B cells, whereas ALL arises from pregerminal B cells. Therefore, a direct transformation of DLBC lymphoma to ALL appears unlikely. The overall features suggest instead separate lymphoma and leukemic evolution from a common mutated B-cell precursor rather than transformation of DLBC lymphoma to ALL.

Aged↗
PubMed2004

Relation of arterial stiffness with gestational age and birth weight.

BACKGROUND: The cardiovascular risk of individuals who are born small as a result of prematurity remains controversial. Given the previous findings of stiffer peripheral conduit arteries in growth restricted donor twins in twin-twin transfusion syndrome regardless of gestational age, we hypothesised that among children born preterm, only those with intrauterine growth retardation are predisposed to an increase in cardiovascular risks. AIM: To compare brachioradial arterial stiffness and systemic blood pressure (BP) among children born preterm and small for gestational age (group 1, n = 15), those born preterm but having birth weight appropriate for gestational age (group 2, n = 36), and those born at term with birth weight appropriate for gestational age (group 3, n = 35). METHODS: Systemic BP was measured by an automated device (Dinamap), while stiffness of the brachioradial arterial segment was assessed by measuring pulse wave velocity (PWV). The birth weight was adjusted for gestational age and expressed as a z score for analysis. RESULTS: The 86 children were studied at a mean (SD) age of 8.2 (1.7) years. Subjects from group 1, who were born at 32.3 (2.0) weeks' gestation had a significantly lower z score of birth weight (-2.29 (0.63), p<0.001), compared with those from groups 2 and 3. They had a significantly higher mean blood pressure (p<0.001) and their diastolic blood pressure also tended to be higher (p = 0.07). Likewise, their brachioradial PWV, and hence arterial stiffness, was the highest of the three groups (p<0.001). While subjects from group 2 were similarly born preterm, their PWV was not significantly different from that of group 3 subjects (p = 1.00) and likewise their z score of birth weight did not differ (-0.01 (0.71) v -0.04 (1.1), p = 1.00). Brachioradial PWV correlated significantly with systolic (r = 0.31, p = 0.004), diastolic (r = 0.38, p<0.001), and mean (0.47, p<0.001) BP, and with z score of birth weight (r = -0.43, p<0.001). Multiple linear regression identified mean BP and z score of birth weight as significant determinants of PWV. CONCLUSION: The findings of the present study support the hypothesis that among children born preterm, only those with intrauterine growth retardation are disadvantaged as a result of increase in systemic arterial stiffness and mean blood pressure.

Birth Weight↗
PubMed2004

A case of Langerhans' cell histiocytosis of the lung presenting with haemoptysis.

Langerhans' cell histiocytosis of the lung can be part of a multisystem disorder or an isolated disorder. Ninety percent of adult patients with Langerhans' cell histiocytosis of the lung are smokers. This article reports a case of Langerhans' cell histiocytosis presenting with haemoptysis. The diagnostic signs on chest X-ray, high-resolution computed tomography, and histology are highlighted, followed by a short review of the literature.

Adult↗
PubMed2004

Management of extremity soft tissue sarcoma after unplanned incomplete resection: experience of a regional musculoskeletal tumour centre.

This study reviews the presentation and management of extremity soft tissue sarcoma after unplanned incomplete resection in a musculoskeletal tumour centre in Hong Kong. Medical records of 18 patients who were referred to our centre for further management from January 1995 to May 2001 after inadequate tumour excision were reviewed. Fourteen patients had been referred from private clinics and four from public hospitals. At initial presentation, 10 patients had lesions exceeding 5 cm, nine had a tumour deep in the subfascial plane, and eight had tumours that had recently increased in size. Sixteen had no preoperative radiological assessment or biopsy performed before excision. All except two patients needed additional skin and muscle reconstruction in a subsequent re-resection, and 12 required postoperative radiotherapy. Two patients subsequently developed distant metastases, and one patient died of an unrelated cause. No amputations were required, and no major complications arose from second surgery. Physicians' alertness towards the possible malignancy of soft tissue masses in extremities is important to avoid a potentially mutilating second resection. Well-planned re-resection in a specialised tumour centre can achieve satisfactory local control of disease.

Academic Medical Centers↗
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

A case of severe haemolytic disease of the newborn due to anti-Di(a) antibody.

Red cell allo-antibodies directed against the Diego (Di) blood group antigen have rarely been reported to cause a haemolytic reaction against transfusion or haemolytic disease of the newborn. The frequency of the Di(a+) phenotype among the Hong Kong Chinese population is estimated to be 4.4%. We report on a case of severe haemolytic disease of the newborn due to anti-Di(a) antibody--the first local case to the best of our knowledge. Rare but clinically significant antibodies targeting red blood cells have to be considered in the investigation of haemolytic disease of the newborn when common underlying factors have been eliminated.

Blood Group Antigens↗
PubMed2004

Infective endocarditis in childhood: a seven-year experience.

INTRODUCTION: The epidemiology, clinical features, treatment and outcomes of infective endocarditis (IE) are reviewed. METHODS: A retrospective descriptive study was performed involving patients treated for IE at a paediatric tertiary centre in Singapore, between May 1997 and April 2004. Duke criteria were used to retrospectively evaluate the diagnosis of IE in these cases. Data analysis was performed using SPSS for Windows. RESULTS: There were a total of 27 children with IE in the seven-year study period. Of these, 24 (88.9 percent) had congenital heart disease, one had rheumatic valvular heart disease and two had normal anatomy. Fever (81.5 percent) was the primary presenting symptom, while splenomegaly (40.7 percent) and septic spots (22.2 percent) were the most common physical findings. C-reactive protein was raised in all cases with a mean of 100.1mg/L. Blood cultures were positive in 77.8 percent of cases and the most common organism identified was Viridans Streptococcus species (25.9 percent). Vegetations were detected on echocardiography in 55.5 percent of cases. According to the Duke criteria, 48.1 percent of our patients fulfilled the clinical diagnosis of definite IE and 51.9 percent had possible IE. The median duration of parenteral antibiotics was 31 days. Major complications were seen in seven (25.9 percent) patients, of whom five had either left heart vegetations or a right-to-left shunt physiology. CONCLUSION: IE is an uncommon infection in childhood and occurs primarily in patients with congenital heart disease. Rheumatic heart disease is rarely a predisposing cause in our local children. Early diagnosis of IE is challenging and depends on a high index of suspicion. Useful clues include the presence of splenomegaly, septic emboli, microscopic haematuria and high C-reactive protein level greater than 100mg/L. The Duke criteria for the diagnosis of IE are relevant locally, but if modified with an expanded list of minor criteria including the above useful clues, may increase the sensitivity of diagnosing definite IE. The presence of left-sided heart vegetations is a strong predictor of complications and must be treated aggressively.

Adolescent↗
PubMed2003

Successful outcome after serial amnioreductions in triplet fetofetal transfusion syndrome.

BACKGROUND: Triplet fetofetal transfusion is an extremely rare complication with high perinatal mortality. Its rarity does not allow any prospective randomized study on various interventional methods to be conducted. CASE: We report one case of triplet fetofetal transfusion syndrome with survival of all three fetuses. Two were donor fetuses, and one was the recipient fetus. Serial amnioreductions were performed at 22, 24, and 26 weeks' gestation to relieve symptomatic polyhydramnios. Premature rupture of membranes occurred at 27 weeks and cesarean delivery was performed. All three babies were discharged home by 4 months of age, and all had normal neurological development when assessed at 6 months of age. CONCLUSION: The option of serial amnioreduction, with the anticipation and preparation for delivery at around 28 weeks, should be seriously considered when triplet fetofetal transfusion syndrome is encountered.

Adult↗
PubMed2003

All that wheezes is not asthma.

Asthma is a common disease. Wheezing is not pathognomonic of asthma, however. One must be alert when appropriate asthmatic treatment does not provide adequate control. Other causes of airway obstruction must be considered, especially when stridor is heard. This report describes an elderly patient who had been managed as having asthma but had an endotracheal tumour.

Aged↗