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Biomedical subjects

Yu-Wen Chen

Publications and source records attributed to Yu-Wen Chen.

At least 19 recordsLinked to original sources
PubMed2006

Dextromethorphan, 3-methoxymorphinan, and dextrorphan have local anaesthetic effect on sciatic nerve blockade in rats.

Dextromethorphan has been used as an antitussive for more than 40 years and is considered a drug with a good margin of safety. The aim of the study was to evaluate whether dextromethorphan and its metabolites--3-methoxymorphinan and dextrorphan--had local anaesthetic effects. Using a method of sciatic nerve blockade in rats, the potencies and durations of actions of dextromethorphan and its metabolites on sciatic nerve blockades of motor function, proprioception, and nociception were evaluated. Lidocaine was used as control. We found that dextromethorphan and its metabolites produced dose-related local anaesthetic effects on sciatic nerve blockades of motor function, proprioception, and nociception. The ranks of potencies were lidocaine>dextromethorphan>3-methoxymorphinan>dextrorphan (P<0.01 for each comparison). Under an equi-potent basis, dextrorphan and 3-methoxymorphinan had durations of actions longer than that of lidocaine (P<0.05 for each comparison). Co-administration of dextromethorphan or its metabolites with lidocaine produced an additive effect on sciatic nerve blockades. In conclusion, dextromethorphan and its metabolites - 3-methoxymorphinan and dextrorphan- had a local anaesthetic effect on sciatic nerve blockades of motor function, proprioception and nociception with durations of actions longer than that of lidocaine. Co-administration of dextromethorphan and its metabolites produced an additive effect on sciatic nerve blockades.

Anesthetics, Local↗
PubMed2006

Health beliefs and practices related to breast cancer screening in Filipino, Chinese and Asian-Indian women.

BACKGROUND: Cultural-appropriate strategies can be designed to promote cancer screening if the unique needs and characteristics of ethnic groups are identified. Most of the data available for Asian immigrants living in the U.S. has been aggregated under the Asian-American/Pacific Islanders (AAPI) ethnic category. METHODS: A total of 125 women completed self-administered questionnaires that assessed screening practices (i.e. breast self-exam, clinical breast exam, and mammography), related beliefs and knowledge. This paper reports examined cancer-related practices and beliefs among three subgroups of Asian-American women (47 Filipinos, 40 Chinese, and 38 Asian-Indians). RESULTS: The sample mean age was 50.2 years and majority of women (76%) were married. Their length of residence in the United States ranged from less than one year to 37 years, with an average length of residence of 18 years. Results from two-way analyses of variance (ANOVAs) showed the strong influence of ethnicity on perceptions of susceptibility [F(2, 95) = 5.11, p = 0.01] and seriousness [F(2, 99) = 4.85, p = 0.01] related to breast cancer, in addition to an interaction detected between ethnicity and income in terms of perceived barriers [F(5, 107) = 3.04, p = 0.01]. The results also indicated that three common barriers were reported in all three ethnic groups, and three unique barriers were more frequently identified by Chinese (i.e. do not need mammogram if I feel ok [OR = 5.450, 95%; CI = (1.643, 18.081)] and waiting time is too long [OR = 5.070, 95%; CI = (1.674, 15.351)]) and Asian-Indian women (i.e. do not know where to get a mammogram [OR = 9.237, 95%; CI = (3.153, 27.059)]). CONCLUSIONS: These findings can be used to develop interventions that are tailored to the special characteristics of immigrant women from different Asian groups.

Adult↗
PubMed2006

Is early dynamic lymphoscintigraphy for detection of sentinel lymph nodes always achievable in breast tumor?

OBJECTIVE: In this article, we will discuss the achievement of early dynamic lymphoscintigraphic protocol and compare detection of sentinel node between benign and malignant breast tumors, and whether pathologic factor is related or not. METHODS: During a six-month period, consecutive fifty-nine patients were enrolled into our study. The average age of patients was 47.6 +/- 9.8 years and all of them were clinically suspected of having breast cancer. The average tumor was 2.1 +/- 1.1 cm in size. First, Tc-99m sulfur colloid was injected around corners of palpable mass or biopsy cavity by the hybrid injection method. Immediately thereafter, dynamic protocol of lymphoscintigraphy, with 10 sec per frame for 60 frames was performed by established simultaneous dual-head vertical angle imaging technique. And delayed two-hour image was also acquired. All patients underwent surgery sixteen to twenty hours later and had a final pathological diagnosis. RESULTS: Among 59 patients, 14 of them were diagnosed with fibroadenoma and the other 45 cases with malignant conditions, infiltrating duct carcinoma mostly. The average age of the two groups was similar. From the summation image of dynamic study, identified axillary sentinel nodal activity was found as 80% in the group of benign breast tumor, but only 48% in the group of malignant breast tumor. In more than 88% of patients, sentinel lymph node was detectable on the delayed two-hour image between the two groups. CONCLUSIONS: Early dynamic protocol of pre-operative lymphoscintigraphy is helpful to clarify the relationship between the local lymphatic drainage basin and sentinel nodal uptake. However, this short period of protocol is not always achievable to detect sentinel node, especially in the group with breast malignant lesions.

Adult↗
PubMed2006

Doxepin has a potent and long-acting spinal anesthetic effect in rats.

Doxepin, a tricyclic antidepressant, was recently found to be effective in the treatment of various acute and chronic painful conditions. However, the mechanism of its actions was not clear, especially when involving the spine. The aim of our study was to evaluate the spinal anesthetic effect of doxepin. Two commonly used traditional local anesthetics, bupivacaine and lidocaine, were used as controls. The potencies and durations of the drugs' action were evaluated in male Sprague-Dawley rats. We found that intrathecally administered doxepin, like bupivacaine and lidocaine, produced dose-related spinal anesthetic effects on motor activity, proprioception, and nociception. Among the three drugs, doxepin produced spinal anesthetic effects in rats more potent than that of lidocaine (p < 0.001, in each comparison) and longer than that of bupivacaine and lidocaine (p < 0.001, in each comparison). The spinal activity of doxepin may provide some explanation of its clinical effect in pain management.

Anesthesia, Spinal↗
PubMed2006

Novel depots of buprenorphine prodrugs have a long-acting antinociceptive effect.

An analgesic with a prolonged duration may be desirable in patients with long-lasting pain. In this study, we evaluated the antinociceptive effects and durations of action of three novel depots of buprenorphine esters buprenorphine propionate, enanthate, and decanoate given by IM injection, in rats. The pharmacokinetic profiles of buprenorphine in blood after IM injection of these depots were also evaluated. Antinociception was evaluated using the plantar test. Buprenorphine concentrations in blood were assayed using high-performance liquid chromatography. We found that the traditional form of buprenorphine HCl (in saline) produced a dose-related antinociceptive effect. A dose of 0.6 micromol/kg buprenorphine HCl (in saline) produced a significant antinociceptive effect lasting 5 h. The same dose of buprenorphine base, propionate, enanthate, and decanoate (in oil) also produced a significant antinociceptive effect with longer durations of action of 26, 28, 52, and 70 h, respectively. The pharmacokinetic studies demonstrated that all the buprenorphine esters were prodrugs of buprenorphine. We conclude that the novel depots of buprenorphine prodrugs: buprenorphine propionate, enanthate, and decanoate produced a long-acting antinociceptive effect after IM injection in rats.

Analgesics, Opioid↗
PubMed2005

A probable role for IFN-gamma in the development of a lung immunopathology in SARS.

Recent work carried out in our laboratory showed the existence of a cytokine storm in SARS patients, dominated by Th1-type mediators. We thus hypothesized that IFN-gamma may play a major role in the pathology by triggering immune-mediated alveolar damage. As we assessed or re-assessed some effects of IFN-gamma on a number of human lung epithelial and fibroblast cell lines, chosen for their wide use in the literature, we found that alveolar epithelial cells were more sensitive to IFN-gamma, in terms of proliferation inhibition and enhancement of Fas-mediated apoptosis. While similar effects were obtained on fibroblasts, concentrations of IFN-gamma 4--8-fold greater were required. In addition, both epithelial and fibroblastic cell lines were able to secrete large quantities of T cell-targeting chemokines, similar to the ones detected in SARS patients. Based on the clinical data collected previously, the available literature and our in vitro experimentation, we propose that IFN-gamma may be responsible for acute lung injury in the late phase of the SARS pathology.

Apoptosis↗
PubMed2005

Bowman-Birk inhibitor abates proteasome function and suppresses the proliferation of MCF7 breast cancer cells through accumulation of MAP kinase phosphatase-1.

The Bowman-Birk inhibitor (BBI), a soybean-derived protease inhibitor with well-characterized ability to inhibit trypsin and chymotrypsin activities, has been shown to be an effective suppressor of carcinogenesis and treated in human phase IIa clinical trial. However, the precise mechanisms by which BBI suppresses carcinogenesis are unknown. In this study, we demonstrated that BBI specifically and potently inhibits the proteasomal chymotrypsin-like activity in vitro and in vivo in MCF7 breast cancer cells. Proteasome inhibition by BBI is associated with accumulation of ubiquitinated proteins and the proteasome substrates, p21Cip1/WAF1 and p27Kip1, accompanied with downregulation of cyclin D1 and cyclin E which could arrest cell cycle at G1/S phase. Moreover, BBI suppressed MCF7 cell growth and had a novel effect on the decrease of phosphorylated extracellular signal-related kinases (ERK1/2). However, BBI was unable to inactivate ERK1/2 in the presence of a phosphatase inhibitor or a transcription inhibitor suggesting the involvement of a specific phosphatase. We found an induction of MAP kinase phosphatase-1 (MKP-1) in dose- and time-dependent manner correlated with dephosphorylation of ERK1/2 in BBI-treated MCF7 cells. In addition, BBI exhibited no inhibitory effects on EGF-stimulated activation of ERK1/2 and Akt. Together, we suggested that BBI abates proteasome function and results in upregulation of MKP-1, which in turn suppresses ERK1/2 activity. Our results support the notion that proteasome inhibition by BBI is a novel mechanism that contributes to prevention of cancer and further provides evidence that soybean products have the potential to advance as chemopreventive agents.

Breast Neoplasms↗
PubMed2005

Value of nodal drainage patterns and tumor location from lymphoscintigraphic mapping in detecting axillary sentinel lymph node status in breast cancer: experience at Kaohsiung Medical University Hospital.

Sentinel lymph node (SLN) biopsy is an alternative to axillary node dissection for staging breast cancer treatment. In this article, we investigated nodal drainage patterns and tumor location using lymphoscintigraphy to predict the axillary sentinel lymph node status. We enrolled 88 patients with clinically suspicious or biopsy-proven breast cancer from March 2001 to October 2002. The average age of subjects was 48 +/- 4 years and the clinical stage was T(1-2)N0Mx. Tc-99m sulfur colloid was used in a hybrid combination of subdermal and perilesional injections around the selected comers of the tumor or biopsy site. Sentinel lymphoscintigraphy was performed 16-20 hours before surgery. Sentinel nodes were marked on the skin. An intraoperative gamma probe was used to confirm the sentinel lymph node location before biopsy. Most primary tumors were in the outer upper quadrant (52.3%), followed by the inner upper quadrant (17.0%), outer inferior quadrant (12.5%), central areolar area (11.4%), and inner inferior quadrant (6.8%). The nodal drainage patterns on 2-hour lymphoscintigraphy were as follows: axillary alone (76.1%), internal mammary nodes alone (1.1%), both axillary and internal mammary nodes (11.4%), and no drainage (11.4%). Internal mammary lymphatic drainage is related to tumor location in the inner quadrants of the breast. About 11.4% of all patients had poorly identified SLNs on lymphoscintigraphy within a 2-hour period, but there was improvement in the overall detection rate up to 95% by intraoperative gamma probe the next day. Preoperative lymphoscintigraphic mapping has value in providing individual lymphatic drainage patterns and tumor location that are important in the interpretation of the results of SLN biopsy during surgery.

Adult↗
PubMed2005

Exercise paradoxically modulates oxidized low density lipoprotein-induced adhesion molecules expression and trans-endothelial migration of monocyte in men.

Physical exercise can affect the risk of cardiovascular disease. Oxidized-low density lipoprotein (ox-LDL) promotes transendothelial migration (TEM) of monocyte, thereby accelerating the pathogenesis of atherosclerosis. This study investigated how exercise intensity affects monocyte/EC interactions under ox-LDL-mediated condition. Light- (LIE), moderate- (MIE) and high- (HIE) intensity exercise (i.e., 40%, 60%, and 80% VO2max, respectively) on a bicycle ergometer in 18 sedentary healthy men were performed on three separate occasions. Before and immediately after exercise, ox-LDL-promoted expressions of monocyte adhesion molecules and TEM of monocyte, as well as oxidation of LDL and amounts of soluble adhesion molecules in plasma were measured. Analytical results showed that (1) ox-LDL furthered monocyte L-selectin shedding and Mac-1 expression, and an attendant increase in TEM of monocyte, while treating the monocyte with Mac-1 antibody inhibited the ox-LDL-promoted TEM of monocyte; (2) under ox-LDL-treated condition, MIE increased monocyte Mac-1 and LFA-1 expressions, enhancing the TEM of monocyte, whereas HIE downregulated monocyte Mac-1 expression, suppressing the TEM of monocyte; (3) LIE decreased basal LFA-1 expression as well as basal and ox-LDL-promoted TEM of monocyte; and (4) MIE and HIE, but not LIE, elevated plasma ox-LDL level, while there were no significant changes in sL-selectin, sE-selectin, sICAM-1, and sVCAM-1 following these exercises. Therefore, we conclude that monocyte activation and subsequent TEM promoted by ox-LDL are changed by short-term exercise in an intensity-dependent manner. These findings provide a new insight into the may aid the development of suitable exercise intensity enable people to prevent early atherogenesis.

Adult↗
PubMed2004

Effects of exercise training and deconditioning on platelet aggregation induced by alternating shear stress in men.

OBJECTIVE: Alternating shear stress, which resembles the flow condition in stenotic arteries, induces platelet aggregation. This study investigated how exercise training and deconditioning influence alternating shear-induced platelet aggregation (ASIPA) and clarify the mechanisms underlying ASIPA. METHODS AND RESULTS: Thirty healthy male sedentary subjects were randomly divided into control and trained groups. The trained men were trained on a bicycle ergometer at approximately 60% of maximal oxygen consumption for 30 minutes per day, 5 days per week for 8 weeks, and then were deconditioned for 8 weeks. The experimental results indicate the following: (1) short-term strenuous exercise increases the extent of ASIPA and is accompanied by increased the von Willebrand factor (vWF) binding and P-selectin expression on platelets in both the control and trained groups, whereas the enhancement of platelet function decreases after exercise training in trained subjects; (2) at rest and immediately after exercise, ASIPA and the vWF binding and P-selectin expression on platelets are reduced by training, but remain unchanged in the control group; and (3) deconditioning reverses the effects of training on resting and postexercise state. CONCLUSIONS: Exercise training suppresses the extent of ASIPA, probably by reducing vWF binding to platelets and P-selectin expression on platelets. However, deconditioning reverses the training effects. This investigation shows that exercise training decreases resting and severe exercise-promoted platelet aggregation induced by alternating shear stress (ASIPA); moreover, this effect is accompanied by reduced the von Willebrand factor binding and P-selectin expression on platelets. However, the effects of training on ASIPA are reversed to the pretraining state after deconditioning.

Adult↗
PubMed2004

Intrathecal tri-cyclic antidepressants produce spinal anesthesia.

Tri-cyclic antidepressants (TCAs) have been widely used in treating major depressive disorders. Recent studies further demonstrated that TCAs have potent sodium channel blocking effect, and amitriptyline, one of the TCAs, has a potent spinal anesthetic effect. The aim of the study was to evaluate the spinal anesthetic effect of various TCAs and to see whether these TCAs could likewise act as local anesthetics after a single intrathecal injection. Bupivacaine, a potent and long-acting traditional local anesthetic, acted as control. The spinal anesthetic effect of nine TCAs (amitriptyline, doxepin, imipramine, trimipramine, clomipramine, protriptyline, desipramine, nortriptyline, and amoxapine) and three traditional local anesthetics (bupivacaine, lidocaine, and mepivacaine) was evaluated in rats and so were dose-response studies of amitriptyline, bupivacaine, and lidocaine. Under a given concentration of 5mM, bupivacaine had the most potent spinal blockade of motor, propioception, and nociception (P<0.001) and the longest duration of action of nociception (P<0.01) among the three traditional local anesthetics. Under this concentration, amitriptyline had a similar potency but longer duration of spinal blockade of motor, propioception, and nociception (P<0.001) than did bupivacaine, whereas several other TCAs had similar or less potencies of spinal blockade than did bupivacaine. In dose-response studies, amitriptyline had a more potent (P<0.005) and longer duration (P<0.001) of spinal blockade than did bupivacaine. We concluded that intrathecal amitriptyline had a more potent and longer duration of spinal anesthetic effect than did bupivacaine, whereas several other TCAs had similar or less potencies than did bupivacaine.

Anesthesia, Spinal↗
PubMed2004

Shiunko promotes epithelization of wounded skin.

Shiunko is a traditional botanic formula (ointment) which is used clinically for the treatment of wounded skin caused by cuts, abrasions, frost or burn. The aim of this study was to evaluate the effect of Shiunko on epithelization of wounded skin. Experimental cutting wounds on the back skin of Sprague-Dawley rats were induced. Different bacterial inoculations (Pseudomonus aeruginosa and Staphylococcus aureus) and treatment (Shiunko, Povidone-iodine and saline) were arranged herein. The incidences of infection and the speed of epithelization were evaluated. We observed that the incidences of wound infection following Pseudomonas aeruginosa inoculation were lower on both the Shiunko-treated group (0%, p < 0.01) and Povidine-iodine-treated group (5%, p < 0.05), than the saline-treated group (40%). The Shiunko-treated group reported higher percentages of complete epithelization not only on the sterilized wounds (100%) but also on the contaminated wounds (90%) when compared to the saline-treated group (60% sterilized wounds, 40% and 50% contaminated wounds) on day 7 (p < 0.01). Povidone-iodine did not promote epithelization of wounded skin, whereas Shiunko did.

Animals↗
PubMed2004

Risk factors associated with postoperative sore throat after tracheal intubation: an evaluation in the postanesthetic recovery room.

BACKGROUND: Postoperative sore throat after tracheal intubation is an unpleasant and distressing experience to patients. The aim of the study was to carry out a large-scale search for the risk factors of postoperative sore throat in patients undergoing endotracheal general anesthesia. METHODS: During a 6-month study period, patients (> or = 10 years old) who consecutively underwent endotracheal general anesthesia for all kinds of surgical procedures were included. A total of 7541 patients were recruited in our study. RESULTS: Five risk factors associated with postoperative sore throat were identified. They were female gender, age between 30-39, surgical sites within the oral or nasal cavity, or around the neck, use of nitrous oxide during anesthesia, and duration of anesthesia longer than 2 hours. CONCLUSIONS: Five risk factors related to postoperative sore throat were identified in our study.

Adolescent↗
PubMed2004

The antinociceptive effect of buprenorphine and its long-acting ester buprenorphine benzoate in rats.

BACKGROUND: A long-acting analgesic is particularly desirable in patients with long-lasting pain. In order to prolong the duration of action of a potent analgesic, buprenorphine, a buprenorphine ester (buprenorphine benzoate) was synthesized in our laboratory. The aim of the study was to evaluate whether the ester form could have a long-lasting effect. METHODS: Two studies were carried out. In study 1, we evaluated the antinociceptive effect of buprenorphine HCI at dosage of 0.05, 0.1, and 0.6 micromol/kg. In study 2, we evaluated the antinociceptive effect of buprenorphine benzoate at dosage of 0.6 micromol/kg. Male Sprague-Dawley rats (n = 12 in each group of different treatment) were used and the antinociceptive effects of the testing compounds were evaluated using the plantar test (a thermal test). RESULTS: Intramuscular injection of buprenorphine HCI at dosage of 0.05, 0.1, and 0.6 micromol/kg in rats produced dose-related antinociceptive effects with duration of action of 3, 4, and 4 h, respectively. Intramuscular injection of buprenorphine benzoate at 0.6 micromol/kg produced a duration of action of 48 h. CONCLUSIONS: Intramuscular injection of buprenorphine benzoate in rats produced a longer duration of action, which is 12-fold longer than that of buprenorphine HCI.

Analgesics↗
PubMed2003

Usefulness of technetium-99m sestamibi myocardial perfusion SPECT in detection of cardiovascular involvement in patients with systemic lupus erythematosus or systemic sclerosis.

The main purpose of the study was to evaluate the utility of technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (Tc-99m sestamibi SPECT) in detection of cardiac involvement in systemic lupus erythematosus (SLE) or systemic sclerosis (SS) patients. Fifty SLE or SS female patients with cardiac symptom/sign such as chest discomfort and/or dyspnea and/or occasionally palpitation and 50 SLE or SS female patients without any cardiac symptom/sign were investigated using Tc-99m sestamibi SPECT during rest and stress after dipyridamole infusion. Twenty-five age- and sex-matched healthy females were also included as controls in this study. The results of Tc-99m sestamibi SPECT were classified into four types including normal, persistent perfusion defect (PD), reversible perfusion defect (RD), and reverse perfusion defect (RR). The results of Tc-99m sestamibi SPECT in the 25 healthy females were normal. Perfusion abnormalities were detected in 44/50 (88%) symptomatic SLE or SS patients. However, myocardial perfusion abnormalities were only detected in 19/50 (38%) asymptomatic SLE or SS patients (P value<0.05 by a chi2 test). However, for risk factor of coronary artery disease and abnormal resting EKG, the incidences were not significant between symptomatic and asymptomatic patients (P values >0.05 by a chi2 test). Tc-99m sestamibi SPECT is a useful noninvasive imaging modality to detect cardiac involvement in symptomatic or asymptomatic SLE or SS patients.

Adult↗
PubMed2003

Enhanced sentinel lymphoscintigraphic mapping in breast tumor using the graded shield technique.

The graded shield technique was developed to increase the sentinel node detection rate by improving lymphoscintigraphic image contrast. In a 6-month period, 50 women with clinical suspicion of early stage breast cancer (T1 and T2 tumors) were enrolled in this study. The patients had a mean age of 47.2 +/- 10.3 years. A composite graded shield was constructed using three concentric layers of leaded plastic measuring 3 cm, 5 cm, and 7 cm each in diameter. The graded shield was designed with a movable Velcro backing for accurate positioning over the injection site. Images were acquired with a vertical angle dual-head gamma camera using an established injection procedure developed at our institution. The rate of detection of sentinel lymph nodes using lymphoscintigraphic mapping improved from 74% (37/50 patients) to 96% (48/50) using the graded shield (p < 0.05). In addition to the increased detection rate, our technique also increased the number of nodes detected and improved visualization of the adjacent lymphatic basin. By enhancing nodal contrast, we have demonstrated that the graded shield technique is an effective method for improving the rate of sentinel node detection.

Adult↗
PubMed2003

The antinociceptive effect of nalbuphine and its long-acting esters in rats.

A long-acting analgesic is particularly desirable in patients with long-lasting pain. In this study, we evaluated the antinociceptive effect and duration of action of three nalbuphine esters-nalbuphine propionate, enanthate, and decanoate-and observed whether these esters had a long-acting effect. Male Sprague-Dawley rats (n = 12 in each group) were used. Two studies were performed. In Study 1, we evaluated the antinociceptive effect of IM nalbuphine HCl with dosages of 0.25, 1.25, 2.5, 25, and 250 micro mol/kg. In Study 2, we evaluated the antinociceptive effects of IM nalbuphine base and esters with a dosage of 25 micro mol/kg. After 2.5, 25, and 250 micro mol/kg IM injections, we found that nalbuphine HCl produced a dose-related antinociceptive effect with durations of action of 1.5, 2, and 4 h, respectively. After a 25 micro mol/kg IM injection, the durations of action of the nalbuphine esters, nalbuphine propionate, enanthate, and decanoate were 5, 30, and 60 h, respectively. We conclude that, on an equimolar basis, nalbuphine esters produce relatively longer durations of action than nalbuphine HCl.

Analgesics, Opioid↗