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Biomedical subjects

C Y Lee

Publications and source records attributed to C Y Lee.

At least 19 recordsLinked to original sources
PubMed2006

Nasopharyngeal pleomorphic adenoma in the adult.

INTRODUCTION: Salivary gland tumors account for less than 5% of all neoplasms in the head and neck, with pleomorphic adenoma being the most common type. These typically arise in the palate, but we report a rare case of nasopharyngeal pleomorphic adenoma in an adult. MATERIALS AND METHODS: The authors conducted a case report and literature review. RESULTS: The patient presented with unilateral otalgia, tinnitus, and aural fullness. Nasal endoscopy revealed a pedunculated mass adjacent to the left torus tubarius and he was treated with an excisional biopsy. Histologic evaluation demonstrated pleomorphic adenoma. DISCUSSION: Pleomorphic adenomas seldom present as nasopharyngeal masses and have a nonspecific appearance on endoscopy. Microscopic examination has characteristic features to aid in an accurate diagnosis. Treatment is surgical and recurrence is unlikely.

Adenoma, Pleomorphic↗
PubMed2006

Serological survey of racing pigeons for selected pathogens in Taiwan.

To investigate the pathogens that racing pigeons in Taiwan are exposed to, a total of 3764 pigeons from 90 lofts were analysed by collection of blood samples in the period between October 2000 and September 2001. The haemagglutination inhibition (HI) test was performed to detect antibodies against Newcastle disease virus (NDV), type 2 avian paramyxovirus (APMV-2), and egg drop syndrome '76 virus (EDS-76V). The agar-gel precipitin (AGP) test was used to detect antibodies against fowl adenovirus (FAV), goose parvovirus (GPV), and avian reovirus (REO). The virus neutralisation (VN) test was applied to detect antibodies against the serotypes FAV-1 and FAV-8. A rapid serum agglutination test was applied for the detection of antibodies against Mycoplasma spp. Antibodies to several infectious agents were found, including NDV (43.3%), EDS-76V (19.2%), FAV (0.8%), REO (0.5%), APMV-2 (0.2%), Mycoplasma columbinum (10.3%), M. columborale (7.1%), M. synoviae (1.8%) and M. gallisepticum (1.3%). Antibodies against GPV, FAV-1, and FAV-8 were not detected in any serum sample. NDV seroprevalence was significantly higher in pigeons of more than one year of age than in pigeons younger than one year. ND or EDS-76 seroprevalence of pigeons vaccinated with ND vaccine or EDS-76 vaccine was significantly higher than that of pigeons that did not receive any vaccination.

Adenoviridae Infections↗
PubMed2005

Effects of oral administration of insulin-like growth factor-I on circulating concentration of insulin-like growth factor-I and growth of internal organs in weanling mice.

Insulin-like growth factor (IGF)-I is a polypeptide that mediates the growth-promoting action of growth hormone in postnatal animals. The present study was conducted to examine whether orally administered IGF-I would be absorbed into the general circulation and also whether ingested IGF-I would enhance the growth of whole body as well as internal organs, and tissues in 3-week-old ICR-strain female weanling mice. In experiment (Exp) 1, a total of 70 mice received IGF-I orally at 1 microg.g-1 in 0.2-ml PBS or the vehicle alone. Concentrations of IGF-I and glucose in heart blood were measured after killing 5 animals in each group every fourth hour during a 24-hour period. In Exp 2, a total of 40 mice received oral IGF-I administration at 1 microg.g-1 or vehicle every third day beginning from day 0 for a 13-day period. Half the animals were killed at day 7 and the other half at day 13. Weights of whole body and organs/tissues (small intestine, liver, thigh muscle, and brain) were measured every day and at slaughter, respectively. In Exp 1, following the oral IGF-I administration, serum IGF-I concentration increased at hour 4 (p<0.01) and returned to the hour 0 level by hour 8, whereas glucose concentration was lowest at hour 4 and returned to the hour 0 level by hour 16. In the PBS-fed group, neither IGF-I nor glucose concentration changed during the 24-hour period. In Exp 2, weight of small intestine increased (p<0.05) in response to the oral IGF-I, whereas weights of liver and thigh muscle of the IGF-I-fed group were greater (p<0.01) and tended to be greater (p=0.06), respectively, than those of the PBS-fed only at day 13. However, brain weight and serum concentrations of IGF-I and IGF-II were not affected by oral IGF-I administration. Results suggest that although orally administered IGF-I mainly acts at the intestine, a portion of ingested IGF-I is absorbed into the general circulation to enhance the growth of selective organs/tissues in weanling mice.

Animals↗
PubMed2005

Effects of juvenile hormone analogs on new reproductives and colony growth of Pharaoh ant (Hymenoptera: Formicidae).

Two juvenile hormone analogs (JHAs), pyriproxyfen and S-methoprene, were impregnated into dried tuna fish and fed to colonies of Monomorium pharaonis (L.) at very low concentrations (1.0, 2.0, 3.0, 4.0, and 5.0 microg/ml). Its effects on the production of sexuals and colonial growth were observed. Colonies treated with pyriproxyfen yielded sexuals with physical abnormalities. Both female and male sexuals developed bulbous wings, decreased melanization, and died shortly after emergence. Sexuals emerged from colonies treated with S-methoprene did not possess anomalous characteristics. Both pyriproxyfen and S-methoprene did not have significant effects on colonial growth because of the low concentrations of the baits. A commercial bait containing 0.3% S-methoprene (Bioprene-BM) also was evaluated for its efficacy on Pharaoh's ant colonies. Results showed that Pharaoh's ant colonies succumbed to the lethal effects of S-methoprene. Colony members were reduced significantly. Production of queens also decreased significantly in treated colonies and treated queens were unable to lay eggs. JHAs are slow acting and eliminate ant colonies at a relatively slow rate. At low concentrations, pyriproxyfen recorded baffling results, i.e., bulbous wings and demelanized exoskeleton, and it is vital that further studies are initiated to solidify these findings.

Animals↗
PubMed2004

Methicillin-resistant Staphylococcus aureus bacteraemia in neonatal intensive care units: an analysis of 90 episodes.

AIM: To delineate the clinical features of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in infants hospitalized at the neonatal intensive care unit. METHODS: Episodes of MRSA bacteraemia in Chang Gung Children's Hospital neonatal intensive care unit from 1997 to 1999 were reviewed for incidence, predisposing factors, clinical presentations, treatment and outcome. RESULTS: Ninety episodes of MRSA bacteraemia were identified. The overall rate of MRSA bacteraemia was 1.05 per 1000 patient days during the 3-y period. Most of the patients were premature infants (76%), with prior operation or invasive procedures (39%), had an indwelling intravascular catheter (79%) and exposure to antibiotic therapy (96%). A localized cutaneous infection was found in 53.3% of the episodes. The most common clinical diagnoses were catheter-related infections (54.4%), skin and soft tissue infections (21.1%), bacteraemia without a focus (20%) and pneumonia (16.7%). Metastatic infection occurred in 18% of these infants. Among the patients treated with vancomycin for < or = 14 d, 88.7% did not develop any complications, and 11.3% developed a recurrence. CONCLUSIONS: MRSA is an established pathogen in our NICU. MRSA bacteraemia in the neonates predominantly presented as catheter-related infections, and metastatic infections were not infrequently seen. In uncomplicated MRSA bacteraemia, treatment with vancomycin for < or = 14 d seems to be adequate.

Anti-Bacterial Agents↗
PubMed2004

Hypercalcaemia and hypertransaminasaemia in a child with hyperthyroidism.

Hypercalcaemia and hypertransaminasaemia are well recognized and not infrequent findings in hyperthyroidism in adults. Both conditions are seldom reported in children. Here we report the case of a 4-year-old girl with hyperthyroidism associated with hypercalcaemia and hypertransaminasaemia which were reversed after euthyroid state was achieved. We recommend that serum calcium and liver function should always be monitored in children with hyperthyroidism.

Calcium↗
PubMed2004

Mitochondria-targeting drug oligomycin blocked P-glycoprotein activity and triggered apoptosis in doxorubicin-resistant HepG2 cells.

BACKGROUND: Mitochondria are key regulators in apoptosis. This suggests that a mitochondrion can be a target for cancer treatment. To examine the feasibility of this approach, we investigated the effect of oligomycin on the induction of apoptosis in drug-resistant cells. As a mitochondrion-targeting agent, oligomycin inhibits mitochondrial F0F1-ATPase. Of 37,000 molecules tested against the 60 human cancer cell lines of the National Cancer Institute, oligomycin is among the top 0.1% most cell line selective agents. METHODS: Changes in the doxorubicin (Dox) accumulation and mitochondrial potential (Deltapsim) in human hepatocarcinoma HepG2 and its derivative R-HepG2 with Dox resistance were determined by flow cytometry. P-glycoprotein (Pgp) expression and release of cytochrome c from mitochondria were analyzed by Western blot. Cytotoxicity was examined by DNA fragmentation and the alamar blue assay. RESULTS: R-HepG2 cells produced Pgp, showed drug resistance and accumulated less Dox when compared to their parent. In both cell lines, oligomycin depolarized Deltapsim, released cytochrome c and elicited DNA fragmentation. Moreover, oligomycin blocked Pgp activity and accumulated more Dox in R-HepG2. Combined treatment with Dox and oligomycin elicited more cell death. CONCLUSION: Our results suggest that oligomycin could bypass Dox resistance and trigger apoptosis in R-HepG2 cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

Characteristics of granular sludge in a single upflow sludge blanket reactor treating high levels of nitrate and simple organic compounds.

Simultaneous denitrification and methanogenesis were accomplished in a single upflow sludge blanket (USB) reactor. More than 99% and 95% of nitrate and chemical oxygen demand (COD) removal rates were obtained at a loading of 600 mg NO3-N/L x d and 3,300 mg COD/L x d, respectively. The specific denitrification rate (SDR) increased as COD/NO3-N ratios decreased. Maximum SDR with acetate could reach 1.05 g NO3-N/gVSS x d. Significant sludge flotation was observed at the top of the reactor due to the change of microbial composition and the formation of hollow granules. Granules became fluffy and buoyant due to the growth of denitrifiers. Microscopic examination showed that granules exhibited layered structure and they were mainly composed of Methanosarcina sp., Pseudomonas sp., and rod-shaped bacteria.

Bioreactors↗
PubMed2003

Genomic characterisation of the severe acute respiratory syndrome coronavirus of Amoy Gardens outbreak in Hong Kong.

Severe acute respiratory syndrome (SARS) is a global health concern. In Hong Kong, two major outbreaks, one hospital based and the other in the Amoy Gardens apartments, were identified. The frequency of diarrhoea, admission to intensive care, and mortality differed significantly between the two outbreaks. We did genomic sequencing for viral isolates from five Amoy Gardens patients. The virus sequence was identical in four of these five patients. The sequence data from one hospital case and the four identical community cases had only three nucleotide differences. Alterations in the SARS coronavirus genome are unlikely to have caused the distinctive clinical features of the Amoy Gardens patients, and these results highlight the importance of non-viral genomic factors in this outbreak.

Base Sequence↗
PubMed2003

Ultrasound guidance allows accurate needle placement and aspiration from small joints in patients with early inflammatory arthritis.

OBJECTIVES: To compare the accuracy of palpation-guided and high frequency ultrasound-guided needle placement in small joints and to develop a technique to obtain synovial fluid from these joints for diagnosis and research. METHODS: The accuracy of needle placement during palpation-guided proximal interphalangeal (PIP) or metacarpophalangeal (MCP) joint injection was assessed. This was compared with the accuracy of ultrasound-guided needle placement. A joint lavage technique was developed to obtain synovial fluid from these joints. RESULTS: Needle positioning was intra-articular in 59% of palpation-guided injections (6/12 PIP and 4/5 MCP joints). No fluid could be aspirated prior to injection. With ultrasound guidance, initial needle placement was intra-articular in 96% of cases (24/26 PIP and 27/27 MCP joints). Synovial fluid cells were lavaged from 63% of joints (19/25 PIP and 14/27 MCP joints). In only one case was a large effusion seen and this was aspirated directly. CONCLUSIONS: The use of high frequency ultrasound to guide needle placement within a small joint allows for significantly greater accuracy than a palpation-guided approach. When followed by lavage, synovial fluid cells and diluted synovial fluid can be obtained from the majority of small joints. This has important clinical and research implications.

Arthritis↗
PubMed2003

Matrix formalism of electromagnetic wave propagation through multiple layers in the near-field region: application to the flat panel display.

We have developed an electromagnetic (EM) wave propagation theory through a single layer and multiple layers in the near-field and far-field regions, and have constructed a matrix formalism in terms of the boundary conditions of the EM waves. From the shielding efficiency (SE) against EM radiation in the near-field region calculated by using the matrix formalism, we propose that the effect of multiple layers yields enhanced shielding capability compared to a single layer with the same total thickness in conducting layers as the multiple layers. We compare the intensities of an EM wave propagating through glass coated with conducting indium tin oxide (ITO) on one side and on both sides, applying it to the electromagnetic interference (EMI) shielding filter in a flat panel display such as a plasma display panel (PDP). From the measured intensities of EMI noise generated by a PDP loaded with ITO coated glass samples, the two-side coated glass shows a lower intensity of EMI noise compared to the one-side coated glass. The result confirms the enhancement of the SE due to the effect of multiple layers, as expected in the matrix formalism of EM wave propagation in the near-field region. In the far-field region, the two-side coated glass with ITO in multiple layers has a higher SE than the one-side coated glass with ITO, when the total thickness of ITO in both cases is the same.

Journal Article↗
PubMed2003

Klebsiella infection in patients with thalassemia.

Klebsiella infection has previously been reported in a few patients with transfusion-dependent thalassemia. The incidence and clinical spectrum of this infection in our cohort of patients were reviewed retrospectively. Among 160 patients observed for 12 years, there were 15 episodes of Klebsiella infection that occurred in 12 patients (7.5%), resulting in an incidence of 0.78 infections per 100 patient-years. The clinical spectrum included sinusitis (4 cases), intracranial infection (5 cases), septicemia (4 cases), and abscesses of the liver, lung, kidney, and parotid gland (1 case each). Three patients had recurrent infections involving different sites, 2 (16%) died of fulminant septicemia, and 3 (25%) had significant permanent neurological deficits. The antibiotic susceptibility pattern for the isolates was similar to the pattern for isolates recovered in the community. With regard to predisposing factors, iron overload and liver function derangement were found to be significant on univariate analysis (P=.046 and P=.049, respectively) but insignificant on multivariate analysis. Klebsiella infection was a serious and frequently encountered complication in our patients with transfusion-dependent thalassemia, resulting in high mortality and morbidity rates.

Adolescent↗
PubMed2003

Nutrient removal using anaerobically fermented leachate of food waste in the BNR process.

Nutrients removal efficiencies highly depend on the presence of biodegradable organic carbon in the biological nutrient removal (BNR) process but most domestic wastewater in Korea has shown a low C/N ratio and has a small amount of biodegradable COD (chemical oxygen demand). On the other hand, about 11,577 tons of food waste that contains a lot of organic material has been produced in Korea per day. The feasibility and applicability of anaerobically fermented leachate of food waste (AFLFW) as an external carbon source was examined in the laboratory-scale BNR process at different operation conditions with synthetic wastewater and domestic sewage. As the addition of AFLFW increased, the average removal efficiencies of SCOD, T-N, T-P changed from 96%, 60%, and 2% to 90%, 77%, and 67%, respectively. From anoxic nitrate utilization tests, it was observed that once the readily biodegradable COD (especially VFAs) was depleted, the denitrification rate reduced from 8.2 mg NO3-N/g VSS/hr to 0.7 mg NO3-N/g VSS/hr. From the molecular size distribution test, it was concluded that about 60% of soluble COD in effluent, which was considered to originate from AFLFW, had a large molecular size (> 30 kDa) that was not used by microorganisms.

Bacteria, Anaerobic↗
PubMed2003

Consensus statement on iodine deficiency disorders in Hong Kong.

This article reviews the available data on the study of iodine deficiency disorders in Hong Kong and to discuss the approach towards preventing such disorders in Hong Kong. The importance of iodine and iodine deficiency disorders is described, and the available data on the dietary iodine intake and urinary iodine concentration in different populations of Hong Kong are summarised and discussed. Dietary iodine insufficiency among pregnant women in Hong Kong is associated with maternal goitrogenesis and hypothyroxinaemia as well as neonatal hypothyroidism. Borderline iodine deficiency exists in the expectant mothers in Hong Kong. Women of reproductive age, and pregnant and lactating women should be made aware and educated to have an adequate iodine intake, such as iodised salt, as an interim measure. A steering group involving all stakeholders should be formed to advise on the strategy of ensuring adequate iodine intake, including universal iodisation of salt in Hong Kong. Continuous surveillance of iodine status in the Hong Kong population is necessary.

Deficiency Diseases↗
PubMed2003

Effects of ferric ion on bioleaching of heavy metals from contaminated sediment.

Bioleaching is one of the promising procedures for removal of heavy metals from contaminated sediments. The advantages of this biotechnology are that it is easy, efficient, less costly and friendly to the environment. However, the principal disadvantage of this process is its slow kinetics in metal solubilization, which may limit practical application of the bioleaching process. In order to enhance the rate and efficiency of metal solubilization, the ferric ion was used as a catalytic agent in the bioleaching process. It was found that the sediment pH apparently decreased in the bioleaching after addition of ferric ion. The metal solubilization increased quickly after the addition of ferric ion. The rate of metal solubilization was enhanced by the addition of ferric ion, especially for Cr and Pb. An increase in the amount of ferric ion added increased the final efficiency of metal solubilization. The highest final efficiency of metal solubilization was obtained in the bioleaching with 1 g/L of ferric ion. Besides, the growth of sulfur-oxidizing bacteria was not affected by addition of ferric ion in the bioleaching. It was concluded that the kinetics of metal solubilization were enhanced by addition of ferric ion in the bioleaching process.

Bacteria↗
PubMed2002

Mitochondrial targeting drug lonidamine triggered apoptosis in doxorubicin-resistant HepG2 cells.

Mitochondria play a crucial role in the induction and execution of apoptosis. Accordingly, recent suggestions have been made to use agents that directly act on mitochondria to trigger apoptosis so that drug-sensitive and-resistant tumour cells can be eliminated. To test this hypothesis, human hepatocarcinoma HepG2 and its derivative R-HepG2 with doxorubicin (Dox) resistance as a result of expression of P-glycoprotein were used to investigate the effect of lonidamine (LND), a new mitochondrial targeting drug, on the induction of apoptosis. Results from our study indicate that R-HepG2 cells were more sensitive to LND than parental cells in terms of cytotoxicity determined by alamar blue assay. Cell death induced by LND was associated with the hallmarks of apoptosis such as mitochondrial membrane depolarization, release of cytochrome c, phosphatidyl-serine externalization and DNA fragmentation. Moreover, combined treatment of cells with Dox and LND elicited more cell death. Taken together, our results suggest a potential use of LND as an anti-cancer drug to bypass drug resistance and to trigger tumour destruction through apoptosis in HepG2 and R-HepG2 cells.

Antineoplastic Agents↗
PubMed2002

Self perceived work related stress and the relation with salivary IgA and lysozyme among emergency department nurses.

AIMS: To assess and compare the self perceived work related stress among emergency department (ED) and general ward (GW) nurses, and to investigate its relation with salivary IgA and lysozyme. METHODS: One hundred and thirty two of 208 (63.5%) registered female ED and GW nurses participated in the study. A modified mental health professional stress scale (PSS) was used to measure self perceived stress. ELISA methods were used to determine the salivary IgA and lysozyme levels. RESULTS: On PSS, ED nurses had higher scores (mean 1.51) than GW nurses (1.30). The scores of PSS subscales such as organisational structure and processes (OS), lack of resources (RES), and conflict with other professionals (COF) were higher in ED than in GW nurses. ED nurses had lower secretion rates of IgA (geometric mean (GM) 49.1 micro g/min) and lysozyme (GM 20.0 micro g/min) than GW nurses (68.2 micro g/min, 30.5 micro g/min). Significant correlations were observed between PSS and log IgA and lysozyme secretion rates. OS, RES, and COF were correlated with log IgA and lysozyme levels. CONCLUSION: ED nurses, who reported a higher level of professional stress, showed significantly lower secretion rates of salivary IgA and lysozyme compared to GW nurses. Salivary IgA and lysozyme were inversely correlated with self perceived work related stress. As these salivary biomarkers are reflective of the mucosal immunity, results support the inverse relation between stress and mucosal immunity.

Adult↗