Yeung, Pollenhttp://hdl.handle.net/10222/156832024-03-28T09:34:31Z2024-03-28T09:34:31ZScale disparity and spectral transfer in anisotropic numerical turbulenceZhou, Y.Yeung, P. K.Brasseur, J. G.http://hdl.handle.net/10222/367182017-12-21T16:55:00Z1996-01-01T00:00:00ZScale disparity and spectral transfer in anisotropic numerical turbulence
Zhou, Y.; Yeung, P. K.; Brasseur, J. G.
No abstract available.
1996-01-01T00:00:00ZExercise hemodynamic and neurohormone responses as sensitive biomarkers for diltiazem in
ratsYeung, Pollen K. F.Feng, Joe D.Fice, Debbrahttp://hdl.handle.net/10222/367152017-12-21T16:53:27Z2006-05-01T00:00:00ZExercise hemodynamic and neurohormone responses as sensitive biomarkers for diltiazem in
rats
Yeung, Pollen K. F.; Feng, Joe D.; Fice, Debbra
Purpose. To investigate the potential of exercise hemodyanamic and neurohormone
variables as sensitive biomarkers for pre-clinical evaluation of diltiazem (DTZ).
Methods. Sprague Dawley (SD) rats were randomly divided into 3 groups (n = 6-8 each),
and each group received DTZ 10 mg/kg twice daily for 5 doses or saline followed by a
treadmill exercise protocol for 7 min with speed set at 7 m/min at 3% grade. The 3rd
group received saline but no exercise. Results. Exercise increased SBP from 108 +/- 2 to
131 +/- 3 mmHg, and HR from 437 +/- 6 to 503 +/- 6 bpm, and plasma epinephrine
concentrations from 2.0 +/- 0.6 to 5.8 +/- 1.7 ng/mL in control rats (p 0.05).
Conclusion. Exercise hemodynamic and neurohormone responses are sensitive biomarkers
which could be used for safety and efficacy evaluation of DTZ and perhaps also other
calcium antagonists in pre-clinical animal models.
2006-05-01T00:00:00ZDevelopment and validation of a sensitive and specific HPLC assay of cladribine for
pharmacokinetics studies in ratsYeung, P. K.Ferguson, C.Jarrar, A.King, B.Li, M. L.http://hdl.handle.net/10222/366652017-12-21T16:55:00Z2007-01-01T00:00:00ZDevelopment and validation of a sensitive and specific HPLC assay of cladribine for
pharmacokinetics studies in rats
Yeung, P. K.; Ferguson, C.; Jarrar, A.; King, B.; Li, M. L.
PURPOSE: To develop and validate a sensitive and specific HPLC assay for cladribine
(CdA) in plasma for pharmacokinetic studies in rats. METHODS: CdA and the internal
standard AZT were purchased from Sigma-Aldrich Chem. The HPLC system consisted of a
Shimadzu LC-9A pump, a 3 im, 250 x 2.0 mm I.D. high speed C18 column (Jupitertrade
mark), preceded by a 5 im 4 4 mm I.D. C18 guard column (Licrocarttrade mark), an Agilent
Model 1050 UV-VIS detector and a 3395 Integrator. The mobile phase was made up of 0.01M
KH2PO4 (pH 5): methanol: acetonitrile 90:5:5). The system was operated at ambient
temperature with a flow rate of 0.3 mL/min, and UV wavelength at 265 nm, and an
operating pressure of ca. 1.56 kpsi. Extraction of cladribine and AZT from plasma was
achieved by solid phase extraction using 100 mg/mL C18 SPE columns Extra-septrade mark).
The assay was validated for sensitivity, precision, specificity and application for
pharmacokinetic study in rats. RESULTS: Under these conditions, the average retention
times of CdA and AZT were 13.5 and 21 min, respectively, and recoveries were between 80
- 95%. Standard curve constructed from plasma standards was linear from 0.1 ug/mL to 1
ug/mL with regression coefficient (r2) 0.99 or greater. Sensitivity assessed by on
column injection was < 1 ng. Using a 50-uL plasma sample size, the mean intra
assay variations 0.1 ug/mL were 7%, and inter assay variations over a period of 3 months
for 5 separate batches were less than 20%. The assay was used to study a single dose
pharmacokinetic study of CdA in rats after a 2 mg/kg subcutaneous injection. CONCLUSION:
The described HPLC assay has adequate sensitivity and specificity to study
pharmacokinetics of CdA in rats, and could be adapted also to clinical pharmacokinetic
studies.
2007-01-01T00:00:00ZIncidence of Deep Vein Thrombosis in Hospitalized Chinese Medical Patients and the
Impact of DVT ProphylaxisCheng, G.Chan, C.Liu, Y. T.Choy, Y. F.Wong, M. M.Yeung, P. K.Ng, K. L.Tsang, L. S.Wong, R. S.http://hdl.handle.net/10222/366532017-12-21T16:55:00Z2011-01-01T00:00:00ZIncidence of Deep Vein Thrombosis in Hospitalized Chinese Medical Patients and the
Impact of DVT Prophylaxis
Cheng, G.; Chan, C.; Liu, Y. T.; Choy, Y. F.; Wong, M. M.; Yeung, P. K.; Ng, K. L.; Tsang, L. S.; Wong, R. S.
Objective. To evaluate the incidence of deep vein thrombosis in hospitalized Chinese
medical patients and the impact of DVT prophylaxis. Methods. All cases of confirmed
proximal DVT from 1 January 2005 to 31 December 2008 were reviewed retrospectively to
determine the presence of risk factors and whether DVT developed: during hospitalization
in medical wards or in case of readmission with a diagnosis of DVT within 14 days of
discharge from a recent admission to medical wards. The impact of prophylaxis will be
estimated by comparing the annual incidence of proximal DVT among medical patients
hospitalized from 2005 to 2007 with that of 2008 (DVT prophylaxis commonly used).
Results. From 1 January 2005 to 31 December 2008, 3938 Doppler ultrasound studies were
performed for suspected DVT. Proximal DVT was diagnosed in 687 patients. The calculated
incidence of proximal DVT among medical patients hospitalized for at least two days was
1.8%, 2%, and 1.7% for the year 2005, 2006, and 2007, respectively. The incidence was
1.1% for 2008 (P < .001). Conclusion. Proximal DVT was substantial in Chinese
medical patients, and DVT prophylaxis might reduce such risk.
2011-01-01T00:00:00Z