PubMed Health⌕ Search

Biomedical subjects

Y S Ong

Publications and source records attributed to Y S Ong.

7 recordsLinked to original sources
PubMed2001

A membrane protein enriched in endoplasmic reticulum exit sites interacts with COPII.

Although all mammalian COPII components have now been cloned, little is known of their interactions with other regulatory proteins involved in exit from the endoplasmic reticulum (ER). We report here that a mammalian protein (Yip1A) that is about 31% identical to S. cerevisiae and which interacts with and modulates COPII-mediated ER-Golgi transport. Yip1A transcripts are ubiquitously expressed. Transcripts of a related mammalian homologue, Yip1B, are found specifically in the heart. Indirect immunofluorescence microscopy revealed that Yip1A is localized to vesicular structures that are concentrated at the perinuclear region. The structures marked by Yip1A co-localized with Sec31A and Sec13, components of the COPII coat protein complex. Immunoelectron microscopy also showed that Yip1A co-localizes with Sec13 at ER exit sites. Overexpression of the hydrophilic N terminus of Yip1A arrests ER-Golgi transport of the vesicular stomatitis G protein and causes fragmentation and dispersion of the Golgi apparatus. A glutathione S-transferase fusion protein with the hydrophilic N terminus of Yip1A (GST-Yip1A) is able to bind to and deplete vital components from rat liver cytosol that is essential for in vitro vesicular stomatitis G transport. Peptide sequence analysis of cytosolic proteins that are specifically bound to GST-Yip1A revealed, among other proteins, mammalian COPII components Sec23 and Sec24. A highly conserved domain at the N terminus of Yip1A is required for Sec23/Sec24 interaction. Our results suggest that Yip1A is involved in the regulation of ER-Golgi traffic at the level of ER exit sites.

Amino Acid Sequence↗
PubMed2000

Pyogenic liver abscess--a tropical centre's experience in management with review of current literature.

AIM OF STUDY: To perform a retrospective study, with the help of literature review, of the management of patients with pyogenic liver abscess in a general hospital. METHOD: A retrospective study of 73 consecutive patients treated atTanTock Seng Hospital between January 1994 and December 1997 was conducted to determine the demographic, clinical, laboratory, radiological and microbiological characteristics of these patients, as well as the management strategies employed. RESULTS: Liver abscess was more common in males, occurring more frequently in the right hepatic lobe. Most patients presented with non-specific clinical and biochemical features. A raised alkaline phosphatase level was the most common biochemical abnormality found in about two-thirds of patients. Ultrasonography was not as sensitive as computed tomographic scans in detecting abscesses. Klebsiella pneumoniae was the most common etiological agent detected in cultures of blood and abscess aspirates. All patients were treated with intravenous antibiotics. Twenty-two (30%) needed percutaneous catheter drainage and five (7%) required surgical management. There was no hospital mortality in our series. Prolonged hospitalisation was associated with advanced age, degree of loculation within the abscess, concomitant diabetes mellitus and Klebsiella septicaemia. CONCLUSION: Pyogenic liver abscesses require a high index of suspicion for early diagnosis. When appropriate therapy in the form of antibiotics in combination with percutaenous drainage or surgery is administered, mortality is very low. However, significant morbidity is still a problem, particularly in the elderly, diabetic patient.

Adolescent↗
PubMed1996

The effect of domestic water filters on water fluoride content.

The effect of filtration on water fluoride level was investigated in a study using commercially available filters. Testing was carried out in London (low fluoride), Braintree (optimum fluoride, naturally occurring) and Birmingham (optimum fluoride, artificially adjusted). It was found that none of the filters removed fluoride. In Birmingham, but not in either Braintree or London, there was a small, clinically insignificant increase in fluoride levels with filtration using two of the five filters. It is concluded that the water filtration systems tested will not affect the advantage offered by optimum water fluoride levels. Fluoride dietary supplements should not be prescribed for children living in optimal fluoride areas, irrespective of whether they use household filters.

Analysis of Variance↗
PubMed1980

Clinical decision-making with treadmill testing and thallium 201.

Fifty patients were prospectively evaluated for myocardial ischemia utilizing treadmill testing and thallium-201 imaging. By coronary angiography, 43 had significant coronary stenosis and seven were normal. The sensitivity, specificity, accuracy and predictive value of treadmill testing alone (81 per cent, 71 per cent, 80 per cent and 95 per cent) did not statistically differ from that of thallium-201 imaging (70 per cent, 86 per cent, 72 per cent and 97 per cent). Combined treadmill testing and thallium-201 imaging (84 per cent, 71 per cent, 80 per cent and 98 per cent) did not significantly affect the results of treadmill testing alone. Thallium-201 imaging failed to identify a number of patients with high risk lesions. The high prevalence of disease, the presentation of typical angina, preselection bias, multiple lead monitoring and exclusion of patients with abnormalities on the resting electrocardiogram probably accounted for failure of thallium-201 imaging to improve the results obtained with treadmill testing. The use of thallium-201 imaging in certain subsets of patient (resting electrocardiographic abnormalities, nondiagnostic treadmill testing, atypical chest pain or asymptomatic patients with abnormalities on treadmill testing) may be of value. However, the use of thallium-201 imaging as a routine screening procedure for myocardial ischemia in patients with typical angina, without due consideration of the prevalence of the disease in the population, is not justified.

Angina Pectoris↗
PubMed1980

Effect of smoking on the elimination of propranolol hydrochloride.

The effect of smoking on the elimination characteristics of propranolol was determined in 20 patients, 10 smokers and 10 non-smokers, who were taking the drug on a continual basis. Smokers took larger doses than non-smokers. The apparent body clearance (ABC) of propranolol in the smoking group was significantly greater than in the non-smoking group (p less than 0.01). When the serum concentrations were adjusted for body weight and dose, the non-smoking group had significantly higher serum concentrations than did the smoking group. The values for half-live (t 1/2) and elimination (k) demonstrated a trend toward a decreases in t 1/2 and increase in k in the group of smokers.

Adult↗