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Yu-Wen Chen

Publications and source records attributed to Yu-Wen Chen.

24 records · Page 2Linked to original sources
PubMed2003

The antinociceptive effect of a long-acting nalbuphine preparation in rabbits.

BACKGROUND: An analgesic with a long-lasting effect is particularly desirable to patients suffering from long-standing pain. The aim of this study was to evaluate the antinociceptive effect and duration of action of an oily dosage form of nalbuphine base and to see whether its effect could last longer compared with nalbuphine HCl. METHODS: Male New Zealand White rabbits (n = 6 in each group) were used. Two studies were carried out. In study 1, we evaluated the antinociceptive effect of intramuscular nalbuphine HCl (in saline) with dosages of 25, 50, and 100 mumol/kg. In study 2, we evaluated the antinociceptive effects of intramuscular nalbuphine base (in sesame oil) with dosages of 100, 200, and 400 mumol/kg. In these studies, the vehicles (saline or sesame oil) were used as controls. A paw pressure test was used to detect the antinociceptive effect of the testing drugs. RESULTS: We found that nalbuphine HCl 25, 50 and 100 mumol/kg produced a dose-related antinociceptive effect with durations of action of 1, 1, and 1.3 h, respectively. Nalbuphine base 100, 200 and 400 mumol/kg also produced a dose-related antinociceptive effect but with longer durations of action of 8, 24, and 48 h, respectively. On an equimolar basis (100 mumol/kg), nalbuphine base produced a 6-fold increase in the duration of action than did nalbuphine HCl. CONCLUSIONS: We conclude that intramuscular nalbuphine base produced a relatively longer duration of action than did intramuscular nalbuphine HCl.

Analgesics, Opioid↗
PubMed2002

Late pulmonary scintigraphic defects after uneventful recovery from focal pneumonia in children: comparison with initial radiograph.

Pulmonary radionuclide studies provide reliable information on regional lung perfusion and ventilation. In children of focal pneumonia with consolidation on the chest radiographs, we determined the association between the initial pneumonia sites and the late lung ventilation-perfusion (V-P) scan abnormalities six months to one year later. Totally fifteen children, 9 males and 6 females, aged 2 to 12 years, were enrolled. All cases had normal chest radiographs in follow up, and had unremarkable respiratory symptoms or signs. Both of 99mTc MAA perfusion scintigraphy and 99mTc DTPA radioaerosol ventilation scintigraphy were performed in 12 cases while the other 3 cases had only perfusion studies. As results of these findings, there were 10 abnormal lung scans, including 9 cases at comparable areas (66%) and one at incomparable area with the initial pneumonia sites. Among those 9 comparable cases, we found 6 ventilation/perfusion (V/Q) matched defects, 2 high V/Q mismatched defects and one decreased perfusion defect. We concluded that abnormal lung V-P scans were frequently after uncomplicated pneumonia in childhood, mostly being matched defects, which may be secondary to local bronchial obstruction and decreased perfusion. However, they seem not always to correlate with the initial pneumonia sites.

Child↗
PubMed2002

The analgesic effect of nalbuphine and its long-acting prodrug, nalbuphine pivalate, in rats.

BACKGROUND: Nalbuphine is an opioid-analgesic with agonist-antagonist properties. Recently, we have synthesized a nalbuphine prodrug, nalbuphine pivalate. The aim of the present study was to evaluate the analgesic effect and the analgesic duration of this prodrug. METHODS: Forty-eight male Sprague-Dawley rats (4 groups, n = 12 in each group) were used. Rats in group 1 received nalbuphine HCl 25 mumol/kg (in saline) intramuscular injection; rats in group 2 received nalbuphine pivalate 25 mumol/kg (in sesame oil) intramuscular injection, whereas those in groups 3 and 4 received saline and sesame oil respectively. The analgesic effects of testing agents were evaluated using the cold ethanol tail-flick test (-30 degrees C). RESULTS: Both nalbuphine HCl and nalbuphine pivalate demonstrated significant analgesic effects. The analgesic duration of nalbuphine HCl was 2 h while that of nalbuphine pivalate was 30 h. CONCLUSIONS: Nalbuphine pivalate has a very long duration of analgesic action. This fascinating finding is worth further evaluation.

Analgesics, Opioid↗
PubMedDate not supplied

Q-wave regression after acute myocardial infarction assessed by Tl-201 myocardial perfusion SPECT.

BACKGROUND: The actual relationship between the interval change of myocardial thallium 201 (Tl-201) radioactivity in the infarct area and the pattern of Q-wave regression is still unknown. This study was conducted to evaluate their relationship after acute myocardial infarction (AMI). METHODS AND RESULTS: A total of 30 patients who had a first Q-wave AMI (11 without Q-wave regression and 19 with Q-wave regression) were retrospectively included. Two sets of 12-lead surface electrocardiograms and Tl-201 myocardial perfusion images were obtained 0 to 2 months and 14 to 84 months after the AMI event, respectively. The acute/subacute redistribution Tl-201 radioactivity was similar between the patients with and those without Q-wave regression. However, the patients with Q-wave regression had higher chronic redistribution Tl-201 radioactivity than those without Q-wave regression. Moreover, the patients with Q-wave regression presented a higher gradient in the redistribution Tl-201 radioactivity between the chronic and acute/subacute images than those without Q-wave regression. CONCLUSIONS: This study supports the role of functional recovery of stunning and/or hibernating myocardium in the disappearance of Q waves after AMI.

Coronary Vessels↗
PubMedDate not supplied

Usefulness of thallium-201 muscle perfusion scan to investigate perfusion reserve in the lower limbs of Type 2 diabetic patients.

This study evaluated the usefulness of thallium-201 muscle perfusion scan (Tl-201 muscle scan) to investigate perfusion reserve in the lower limbs of asymptomatic Type 2 diabetic patients without peripheral ischemia findings. Tl-201 muscle scan was carried out in 36 diabetic male patients with Type 2 diabetes mellitus of more than 10 years in duration who had no evidence of peripheral arterial disease in their history, physical examination, or Doppler ultrasonography. A control group consisted of 24 healthy age-matched nondiabetic men. Each subject flexed their right foot maximally both dorsally and plantar 60 times. In the middle of this exercise, 2mCi Tl-201 was injected intravenously. Three minutes after the injection, a posterior image of both calves was obtained using a gamma camera. Rectangular regions of interest (ROIs) were symmetrically drawn over both calves. The total count (Ct) in the resting calf was subtracted from the Ct in the exercising calf, and the percentage increase, termed the perfusion reserve, was determined. A significant difference was found between the perfusion reserves of the Type 2 diabetic patients and control groups (70.2+/-10.7% and 98.6+/-9.4%, respectively; P<.05). In conclusion, the perfusion reserve in the lower limb muscles in Type 2 diabetic patients may be measured by Tl-201 muscle perfusion scan.

Body Mass Index↗