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Biomedical subjects

J P Luo

Publications and source records attributed to J P Luo.

At least 19 recordsLinked to original sources
PubMed2001

Hospital-based management of acute asthmatic exacerbation: an assessment of physicians' behavior in Taiwan.

This retrospective study was conducted to assess Taiwanese emergency physicians for their preference in management and adherence to guidelines in treating patients with acute exacerbation of asthma. One hundred twenty patients from hospitals of three different levels were evaluated by reviewing their medical records. Our study revealed that physicians from medical centers and regional hospitals assessed patients more often with arterial blood gas or pulse oximetry; prescribed more doses of beta2-agonist nebulizers; administered more doses of beta2-agonist nebulizers before administering parenteral aminophylline; and prescribed ipratropium nebulizers more often as adjunctive therapy. On the other hand, physicians from district hospitals more frequently prescribed parenteral aminophylline as the first-line medication and more often prescribed only a single dose of beta2-agonist nebulizer. Most emergency physicians in Taiwan did not adhere to guidelines. Specifically, these included omission of peak expiratory flow as the means to assess the severity of asthma exacerbation and response to treatment; suboptimal use of inhaled bronchodilators, such as beta2-agonists and ipratropium; and inappropriate use of parenteral aminophylline as the first-line medication.

Acute Disease↗
PubMed2001

Simultaneous modeling of pharmacokinetics and pharmacodynamics of propafenone in healthy subjects.

AIM: To study the simultaneous modeling of pharmacokinetics and pharmacodynamics (PK-PD) of propafenone (Pro) in healthy subjects. METHODS: Ten healthy Chinese volunteers, 5 extensive metabolizers (EM) and 5 intermediate metabolizers (IM) of CYP2D6, received a single dose (400 mg) of Pro hydrochloride. The blood samples and electrocardiogram (ECG) measurements were taken after administration over 15 h period. The concentrations of Pro in plasma were measured by a reverse-phase HPLC. PR interval was used as an average value of 10 PR interval measurements. RESULTS: There was a delay between Pro level and percentage of PR interval prolongation. After PK-PD simulating, the relationship between effect concentration (Ce) and the effect met the sigmoid E(max) model. CYP2D6 (EM & IM) played an important role in both pharmacokinetics and pharmacodynamics which produced by Pro. The AUC (microg . h . L-1) of IM group was significantly higher than that of EM group (5126 +/- 1030 vs 2948 +/- 1230, P < 0.05). Whereas Ce50 (microg/L) was also greater in IM group than in EM group (747 +/- 281 vs 359 +/- 123, P < 0.05). On the other hand, gamma of EM group was about one fold larger than that of IM group (P < 0.05). CONCLUSION: CYP2D6 phenotype of human may influence not only pharmacokinetic of Pro but also its pharmacological effects.

Adult↗
PubMed2001

[Development and application of the facial soft tissue 3D measuring system].

OBJECTIVE: To combine measurement and image technology as an objective means to help prosthodontists provide better service. METHODS: The system was developed by consisting of two CCD cameras, real time hardware for the recognition of markers and software for the 3D reconstruction. RESULTS: It allowed efficient, direct and noninvasive calculation of the 3D liner and angular measurements of the human face. CONCLUSION: This system is a useful way to get 3D information of the human face. It will be a good supplement to the classic cephalometric analyses.

English Abstract↗
PubMed2001

[Validation of the 3D measuring system].

OBJECTIVE: To test the validation of the 3D measuring technique. METHODS: A life-size plaster cast of human head was used as the anthropomorphic model. Fifteen experimental conditions were studied. Nine linear distances between landmarks and Nasion were measured each time. These were compared to the standard anthropometric measurements using the same landmarks. RESULTS: The mean difference was 1.21mm (2.09%). Among the 8 conditions imitating different head posture,only the one turning 10 degrees to the left had a significant difference from the normal position. CONCLUSION: In accordance with the requirements of " human measurement handbook", the system error is acceptable.

English Abstract↗
PubMed2001

[Facial soft tissue three dimensional morphometry].

OBJECTIVE: The purpose of this article were to assess the reproducibility of the landmark locating, and to obtain some facial soft tissue measurements data of the teenagers. METHODS: 8 males were selected to refix the black markers by the same operator and remeasure 14 items by the system, then compare both results. Three dimensional facial morphametry was investigated in a sample of 20 teenagers at the early stage of the permanent dentition. RESULTS: No item of the remeasurement test showed statistical difference error. The sexual dimorphism was found in the measurements connecting with lower face height(Sn-Pg). CONCLUSION: It indicated that the landmarks selected in this study had biologic significance and unique definition. The result of teenager facial measurements is in accordance with growth rule.

English Abstract↗
PubMed2000

[Improved protoplast-derived plants of Astragalus adsurgens through somatic embryogenesis].

Embryogenic callus was obtained only from hypocotyl explants of Astragalus adsurgens and light inhibited the formation of embryogenic callus. A high yield (1.2 x 10(6)/g F. Wt.) of protoplasts with high viability (over 80%) could be isolated from 10-day-old embryogenic callus. Protoplasts were induced to undergo sustained division and to form cell colonies when cultured in agarose-solidified medium (KMP) containing 1/4 strength of mineral salts and supplemented with 1.5 mg/L 2, 4-D, 0.5 mg/L BA and 0.5 mol/L glucose at a plating density of 1.0 x 10(5)mL, where the plating efficinency was 16.8%. Conditioning medium significantly improved the formation of cell colonies. When protoplast-derived colonies were maintained at 4 degrees C for 2 weeks and subsequently transferred onto medium (MS) with 0.1 mg/L NAA and 1.0 mg/L BA, somatic embryogenesis occurred. Frequency of cell colonies producing somatic embryos reached 70%, and the number of somatic embryos per gram cells was over 200. Cultured on hormone-free half-strength MS medium, somatic embryos developed into healthy plantlets with normal chromosome complement.

Cells, Cultured↗
PubMed2000

[Determination of cinnamaldehyde in Guizhi by HPLC].

OBJECTIVE: To establish a HPLC method for the determination of cinnamaldehyde in Guizhi. METHOD: Cinnamaldehyde was separated by a Kromasil C18 column (4.6 mm x 200 mm) with a mobile phase of acetonitrile-0.1% phosphoric acid solution(48:52) and an UV detection wavelength of 285 nm. RESULT: The calibration curve was linear in the range of 0.004-0.02 microliter.ml-1, with a correlation coefficient of 0.9996. The average recovery was 100.7%(n = 5), and RSD 0.3%(n = 6). CONCLUSION: The method is simple and accurate.

Acrolein↗
PubMed1999

Pharmacokinetics of fluphenazine, a highly lipophilic drug, estimated from a pulse dose of a stable isotopomer in dogs at steady state.

The potential utility of a pulse dose of a deuterium-labeled isotopomer (FLU-D(4)) in elucidating the pharmacokinetics of fluphenazine (FLU) at steady state was investigated in dogs. The single-dose oral pharmacokinetics of FLU in dogs were established. After resting the dogs for 3 weeks, the animals were dosed to steady state with oral FLU administered at 12-h intervals. Following 15 doses, one dose of FLU was replaced by a pulse dose of FLU-D(4), after which dosing with FLU was resumed. FLU and FLU-D(4) plasma concentrations were determined by tandem mass spectrometry. Comparable estimates of apparent oral clearance were calculated from (i) a single dose of FLU, (ii) a pulse dose of FLU-D(4), and (iii) over a dosing interval at steady state. Average steady-state plasma concentrations were reliably predictable from a pulse dose of FLU-D(4).

Algorithms↗
PubMed1999

Pharmacokinetics of sustained-release capsule of 5-isosorbide mononitrate in 20 healthy Chinese young men.

AIM: To compare the pharmacokinetics of domestic and imported sustained-release capsule of 5-isosorbide mononitrate (5-IM). METHODS: A single and 5-d-repeated oral doses of 5-IM 50 mg were performed on 2 groups of 20 Chinese healthy subjects (10 subjects for each group) in a randomized crossover protocol. The 5-IM in plasma were measured by gas chromatography with electron-captured detector method. Data were analyzed automatically by using a CAPP program on a PC computer. RESULTS: Fitting the 5-IM concentration-time curves to one-compartment model or following trapezoidal rule, the parameters such as Tmax, Cmax, Ke, MRT, and AUC were calculated and there were no significant differences between the two kinds of capsule. The major pharmacokinetic parameters of domestic and imported 5-IM sustained-release capsule with a 5-d multiple dose were respectively: Cmax (677 +/- 103) and (702 +/- 76) micrograms.L-1; Tmax (5.1 +/- 2.0) and (5.6 +/- 1.3) h; MRT (11.5 +/- 0.5) and (11.4 +/- 0.7) h; AUC0-infinity (12,121 +/- 1346) and (12,352 +/- 988) micrograms.h.L-1. The fraction of drug absorbed in vivo was correlated well with the percentage amount of drug released in vitro at corresponding time (P < 0.05), and the fluctuation indices on d 5 in multiple dose study were not significantly different between the two formulations (P > 0.05). The relative bioavailability of the domestic capsule for single and multiple dose were 96% +/- 11% and 98% +/- 10%, respectively. CONCLUSION: Domestic 5-IM sustained-release capsule showed bioequivalence compared with the imported capsule and provided the same nitrate-low interval in the latter part of the 24-h dosing interval.

Adult↗
PubMed1999

Regeneration of Astragalus adsurgens via somatic embryogenesis from cell suspension protoplasts.

Protoplasts from 4-day-old embryogenic cell suspension cultures of Astragalus adsurgens, when cultured in KM8P medium which ammonium concentration was reduced to 2.5 mmol/L and supplemented with 0.5 mg/L NAA, 1.0 mg/L 2, 4-D, 0.7 mg/L BA and 0.4 mol/L glucose, underwent cell sustained divisions and formed cell colonies at a frequency of 16%-20%. Preplasmolysis or low temperature treatment of suspension cells prior to enzyme incubation enhanced colony formation. Following proliferation on MS medium containing 1.0 mg/L 2, 4-D and 0.5 mg/L BA, cell colonies were cultured on MS medium containing 0.1 mg/L NAA and 1.0 mg/L BA, where approximately 40% of colonies produced somatic embryos ranging in number from 20 to 40 per colony. No significant decrease was found in the potential of somatic embryogenesis when protoplast colonies were obtained from long-term cell suspensions. On hormone-free 1/2 MS medium, somatic embryos developed into intact plants, which showed normal morphology and stable chromosome number.

Astragalus Plant↗
PubMed1998

The roles of depot injection sites and proximal lymph nodes in the presystemic absorption of fluphenazine decanoate and fluphenazine: ex vivo experiments in rats.

PURPOSE: The release and presystemic absorption of fluphenazine and its decanoate ester from intramuscular depots were investigated. METHODS: Rats were sacrificed in groups of three at various times after injection of drug or prodrug in sesame oil. Muscle tissues at the injection sites and various lymph nodes were excised. Blood (plasma) was harvested by cardiac puncture. RESULTS: Following administration of fluphenazine decanoate, the amount of prodrug at the sites of injection declined exponentially (half-life 3.4 days). Highest concentrations of drug and prodrug were found in iliac and hypogastric lymph nodes nearest to injection sites in which both analytes were detectable 28 days post dose. The half-life for the decline of fluphenazine from lymph nodes (4.6 days) was similar to that from plasma (4.3 days). Following administration of fluphenazine base, only 2.8% of the dose remained at the sites of injection after 2 days. Concentrations of drug in iliac and hypogastric lymph nodes were comparable to those in distal lymph nodes. Fluphenazine concentrations in the lymphatic tissues decreased at about the same rate as plasma concentrations. CONCLUSIONS: The rate limiting step appeared to be slow partitioning of the decanoate from oily deposits at the injection site and proximal lymph nodes with subsequent hydrolysis of the ester group.

Absorption↗
PubMed1998

[Research of dynamic measurements of perioral soft tissue]

OBJECTIVE:This article introduced a concept of dynamic image measurement for calculate the quantity of cirumoral soft tissue movements. METHODS: A developed computer image analyzing system was used to calculate the quantity of circumoral soft tissue movement under the three conditions. RESULTS: (1)When/mo/is pronounced,lip protrudes,the upper lip landmarks move upwards,imwards and forwards,and the lower lip landmarks downwards and backwards.The variation of upper lip triangular area will be M2 M2>M1. (2)When/si/is pronounced,as a result of vowel,the amount of lower lip moving down backwards is more than that when/mo/is pronounced,which makes the lower lip triangular area comes to be M3>M2>M1. CONCLUSION: Pronunciation is one of the important oral functins. It could be used as a method of research to measure the facial soft tissue change dynamically and effectively.

Journal Article↗
PubMed1997

Sensitive method for the simultaneous measurement of fluphenazine decanoate and fluphenazine in plasma by high-performance liquid chromatography with coulometric detection.

A highly sensitive and specific high-performance liquid chromatographic method with coulometric detection was developed for the simultaneous assay of fluphenazine decanoate and fluphenazine in plasma. The extraction and sample clean-up procedures are simple, rapid to execute, yet yield chromatograms relatively free of any interference from endogenous plasma constituents, such that the extraordinary sensitivity of the coulometric detector can be exploited fully. This is the first analytical procedure for the simultaneous determination of fluphenazine decanoate and fluphenazine. The detection limits for both fluphenazine decanoate and fluphenazine were 0.1 ng/ml plasma and the limits of quantitation were 0.25 ng/ml plasma. Standard curves from 0.25 to 10 ng/ml were linear with coefficients of variation < 10%. The method was applied to measure plasma levels of fluphenazine decanoate and fluphenazine in patients under medication with 25-50 mg biweekly intramuscular (i.m.) injections of fluphenazine decanoate. It was possible to monitor the plasma levels of fluphenazine in all cases. Fluphenazine decanoate was present in measurable concentration in the plasma of 4 out of 5 patients who received biweekly i.m. injections of 50 mg fluphenazine decanoate. In a pilot experiment with a dog, the method was used to follow fluphenazine decanoate and fluphenazine plasma levels up to 13 days, at least, after i.m. single dose (10 mg/kg).

Animals↗
PubMed1997

Studies on the mechanism of absorption of depot neuroleptics: fluphenazine decanoate in sesame oil.

PURPOSE: The purpose of the present study was to investigate the pharmacokinetic characteristics of fluphenazine (FLU) and its decanoate (FLU-D) after intravenous and intramuscular administration to dogs. METHODS: A group of four beagle dogs was used in all intravenous and intramuscular experiments, with washout periods of no less than three months between doses. RESULTS: After intravenous FLU-D, the pharmacokinetics of the prodrug (mean +/- SD) were as follows: Clearance (CL) 42.9 +/- 6.3 L/h; terminal half-life (t1/2) 3.5 +/- 0.8 h; volume of distribution (Vd) 216 +/- 61 L. The fractional availability of FLU was 1.0 +/- 0.2. After intravenous FLU, the volume of distribution of FLU (51 +/- 17.8 L) was some 4 fold less than that of the prodrug. Simulations (Stella II) suggested that the rate limiting step was slow formation of FLU from the prodrug in the tissue compartment. After intramuscular FLU-D in sesame oil, the apparent t1/2 of FLU was 9.7 +/- 2.0 days whereas after intramuscular FLU base in sesame oil, the apparent t1/2 was only 7.7 +/- 3.4 h showing that the absorption of FLU itself from the intramuscular site and proximal lymph nodes is relatively rapid. CONCLUSIONS: The rate limiting step after intramuscular FLU-D appeared to be the slow partitioning of the prodrug out of the sesame oil at the injection site and in proximal lymph nodes.

Absorption↗
PubMed1997

Pharmacokinetic-pharmacodynamic modeling of metoprolol stereoisomers in spontaneously hypertensive rat.

AIM: To study the combined pharmacokinetic-pharmacodynamic (PK-PD) model of metoprolol stereoisomers, and compare their inhibitory effects on cardiovascular system in the spontaneously hypertensive rats (SHR). METHODS: The drug concentration in plasma was measured by the reversed phase HPLC and the drug effects were recorded by polygraph. The pharmacokinetic parameters and the PK-PD model parameters were calculated. RESULTS: The plasma concentration-time profiles were adequately described by two-compartment model. Differences of Vd between (+)-Met and (-)-Met were found. The relationships between effects and concentration of effect compartment were represented by the sigmoid-Emax model. The Css50 of Vmax, dp/dtmax, and HR inhibitory effects of (+)-Met were larger than those of (-)-Met. CONCLUSION: Stereo-selective drug distribution and different potencies of the inhibitory effects of (+)-Met and (-)-Met existed in SHR.

Adrenergic beta-Antagonists↗
PubMed1997

[The establishment of the digital imaging analysis system on the lower maxillofacial soft tissue]

Soft tissue shape is an important parameter to evaluate the postprosthetic effect of facial profile.In this study,the technique of digital imaging analysis was used to transferring from imaging informations to digital information,and then these information were imputed to computer for capturing,measuring and analyzing.So far,a set of digital imaging analysis system relating to the speciality of prosthodontics has been established preliminarily,with the advantage of quantitative analysis,non invasion and accuracy.It will provide a new way for reconstructing vertical dimension of occlusion.

Journal Article↗
PubMed1997

[Analysis of the measurement on of the maxillofacial soft tissue's parameters association with vertical dimension]

The rehabilitation of vertical dimension of occlusion(VDO) exactly is one of the most important procedure for dental prosthesis in the field of prosthodontics.In this study,total of 19 subjects with normal range occlusion were selected.We measured 33 parameters relating to VDO of their facial soft tissue at intercusping position,with the technique of digital imaging analysis.The results as follows:we established a set of normal values of facial soft tissue parameters,which is suitable for the age group of 21-24 years old.It would provide an objective criterion for the rehabilitation of VDO.Also the normal values in this studies had been compared with other other studies,and it showed that the values of some parameters in our study,such as CH-CH',nasolabial angle were very close to oter data.Furthermore,it was found that both the position of the upper lip and the lower lip of the subjects were more anterior to that of white men,while the degrees of nasolabial and labiomental convexity were less obvious.

Journal Article↗