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Biomedical subjects

P Xiang

Publications and source records attributed to P Xiang.

17 recordsLinked to original sources
PubMed2001

The stability of tetramine, morphine and meperidine in formalin solution.

The stability of tetramine, morphine and meperidine in formalin solution is an important factor for drug analysis in forensic investigation. In this paper, the tissues (liver, kidney, lung and heart) from poisoned rabbits were immersed in 50 ml 10% formalin solutions for 4 months before examination. We compared the levels of tetramine, morphine, meperidine and the main metabolite normeperidine, measured by GC/NPD or GC-MS, in frozen rabbit tissues, formalin-fixed rabbit tissues, and formalin solution. There was a decrease in the levels of tetramine, morphine, meperidine in formalin-preserved tissues compared with the levels of these drugs in the frozen tissues. It is suggested that the formalin-fixed tissues and formalin solution should be analyzed at the same time to assure the accurate results.

Animals↗
PubMed2001

[Study of distribution and metabolism of methamphetamine in hair of guinea pig].

OBJECTIVE: To study the distribution and metabolism of methamphetamine in the hair of guinea pig. METHODS: Determination of methamphetamine and its metabolite amphetamine in hair was performed by GC/MS and GC/NPD. Concentration-time course of methamphetamine and amphetamine in hair of guinea were recorded. Relationship between hair color, administrated dose and drug concentration in hair were also discussed. RESULTS: The concentration of amphetamine is higher than the concentration of methamphetamine in the hair of guinea administrated a single dose or seven doses of methamphetamine. The concentration of methamphetamine and amphetamine were significantly related with administration dose and the incorporation rate into white and brown hair is much poorer than that of black hair. CONCLUSION: Administration methods, dose and the color of hair affect the concentration of methamphetamine and amphetamine.

Amphetamine↗
PubMed2000

[Detection of antidepressant and antipsychotic drugs in human hair and evaluation of the results].

The presence of therapeutic drugs in the hair of psychiatric patients was investigated, and the method for simultaneous determination of antidepressant and antipsychotic drugs by GC/NPD and GC/MS was also established. Eight different psychotroic drugs were detected from the hair of 32 subjects, and chlorpromazine and clozapine concentrations in the hair were found to be dependent on the dosage and the correlation coefficients were 0.8047 (P < 0.001, n = 16) and 0.7097 (P < 0.001, n = 16) respectively. Segmental analysis demonstrated that there was a correlation between the subject's drug exposure history and the distribution of drug along the hair shaft.

Adult↗
PubMed1999

[Zinc deficiency inhibited the proliferation and differentiation of rat osteoblast in vitro].

The effect of zinc deficiency on proliferation and differentiation of rat osteoblast was studied in vitro. The osteoblasts were isolated from the rat calvaria, and were subcultured in DMEM medium. Zinc deficiency model in cell culture was made by chelating zinc from the medium with a special chelator TPEN. Incorporation of 3H-thymidine was measured to show the DNA synthesis at different time point, and cell cycle was analyzed by flow cytometry. A histochemistry method was used to detect changes of osteoblast cytoskeleton. Incorporation of 3H-proline was measured to show the synthesis of collagen. Alkaline phosphatase activity (AKP) and osteocalcin content were measured by enzyme dynamics method and radioimmunoassay respectively. The results showed that the incorporation of 3H-thymidine in the zinc deficient group was significantly less than that in the control group at different time points. The cells were blocked at G2/M phase of cell cycle, which is related to the impairment of cytoskeleton. Collagen synthesis, osteocalcin content and AKP activity in the zinc deficient group were reduced significantly as compared with those in the control group. But no differences in all the measurements were observed between the control group and the group of zinc deficiency supplemented with zinc. Therefore, it was concluded that zinc deficiency inhibited the proliferation and differentiation of rat osteoblast in vitro.

Alkaline Phosphatase↗
PubMed1999

[Study on the radioligand binding assay of cholecystokinin receptor in rat cerebral cortex].

A radioligand binding assay system for determining the characterization of CCK receptor is presented. Using Bolton-Hunter reagent, we prepared a biologically active, specific 125I-BH-CCK8. The iodination mixture was then transferred to a column of Sephadex G-25 and examined by silica thin layer chromatography. Its specific activity and radiochemical purity were 3.4 TBq/mmol and 96% respectively. Binding of 125I-BH-CCK8 to the membrane of rat cerebral cortex was rapid, reversible, time-temperature dependent, saturable and specific. The labeled CCK was shown to have biological activity as measured by the CCK receptor radioassay. Under our laboratorial conditions, the CCK binding required an hour to reach equilibrium at 4 degrees C. We chose polyethylene glycol 6,000 and gamma-globulin protein for the separation of B and F. Scatchard plot of CCK binding was linear with a Kd value of 1.098 nmol/L and Bmax of 197.5 fmol/mg protein. The results of this study support the stand-point that CCK may function as a regulatory peptide in brain and hence may be of use for clarifying the CCK receptor's function in central nervous system.

Animals↗
PubMed1999

[Analysis of penicillins in whole blood by reversed high-performance liquid chromatography].

A reversed-HPLC method was established to determinate penicillins in whole blood. Thiamphenicol as internal standard was added to 0.5 ml blood. Proteins in blood were precipitated with acetonitrile, then the separate supernatant was directly injected onto the chromatography column. The range of five penicillins' linearities was 0.9918 to 0.9996, their range of relative recovery was 91.75% to 107.33%, their CV was 3.56% to 9.85%. Effects of different storage temperatures on the stability of analytes and interference of other antibiotics were also studied.

Animals↗
PubMed1999

[Determination of metabolites of heroin in urine and discrimination of heroin abuse].

This article describes a sensitive method that detects morphine, 6-monoacetylmorphine, morphine-3-glucuronide and codeine in urine for qualifying the abuse of heroin. The analytes were extracted by solid phase C18. The limits of detection (LOD) for morphine and codeine were 50 ng/ml and 50 ng/ml, respectively. The RSD of morphine and codeine were 11.3% (n = 5), and 14.2% (n = 5) respectively. For urine, it does not need to be hydrolyzed before extracted, and for all analytes, also need not to be derivated. The difference ratio of morphine and codeine in the chromatography can be used to discriminate between the abuse of heroin and the administration of compound liquorice mixture.

Codeine↗
PubMed1999

[Segmental analysis of hair from meperidine abusers and evaluation of the results].

Using meperidine abusers as subjects for this study, we detected in hair meperidine and its metabolites normeperidine, N-OCH3-meperidine and N-AC-meperidine. The content of meperidine and normeperidine of 60 abusers were 103 +/- 130 ng/mg and 117 +/- 143 ng/mg respectively. Meperidine was stably present in hair for at least 20 months. Normeperidine level decreased from hair root to tip. The segmental analysis of hair revealed that there were correlations between the drug abuse history and the distribution of drug along the hair shaft, and between the dose of meperidine and its content presented in hair.

Female↗
PubMed1999

[Determination of heroin metabolites in biological fluids, tissues and hair of heroin addicts using GC/MS-SIM].

Using GC/MS-SIM, we examined morphine distribution in human bodies of 2 delayed death cases and analyzed content of morphine and 6-acetylmorphine (MAM) in hair specimens of 7 cases. After hydrolysis and extraction, MOR and 6-MAM were derived with acetic anhydride or BSTFA and then the derivatives were qualitatively and quantitatively analyzed by GC/MS-SIM. The results indicated that urine, bile and liver were the best samples to reveal the heroin-related deaths. Hair analysis has its unique advantage for its long time of abusing monitor, compared to biological fluids.

Female↗
PubMed1998

The development of self-perceptions of ability and achievement goals and their relations in physical education.

This study examined the development of self-perceptions of ability and achievement goals and their relationships in physical education. Three hundred and eight students in 4th, 8th, and 11th grades completed questionnaires assessing their goal orientations, conceptions of ability, and perceived competence in physical education. Analyses assessing grade-related changes in conceptions of ability and achievement goals showed that as the students progressed from grades 4 through 11, they were more likely to: (a) interpret ability as a stable capacity that may limit or increase the effect of effort on performance and (b) become ego-oriented. Analyses assessing relationships between variables of interest across grade level revealed that achievement goals were related to different conceptions of ability, students' self-ratings were significantly positively correlated to their teachers' ratings of their competence, and no consistent relationships emerged between achievement goals and perceived competence.

Achievement↗
PubMed1998

[Analysis of MDMA and its metabolites in urine by GC and GC/MS].

The purpose of this study is to investigate the metabolism of MDMA in the person and establish the methods for the determination of MDMA and its metabolites in urine. MDMA and its metabolite were isolated from urine by liquid-liquid extraction after acidic or enzymatic hydrolysis and were determined by GC/MS(EI, PCI) and GC/FID. The results showed that MDMA was metabolized to MDA and HMMA in man. MDA in the urine after MDMA administration was approximately 0.10-0.14 that of the parent drug. The sensitivity limits of methods were 2-50 ng/ml, and the recoveries were greater than 85%(CV < 10%). It is concluded that the methods were simple, quick and accurate for determining urine concentration of MDMA addicts. MDA/MDMA Ratio can be used to indicate whether the parent drug is taken alone or in combination with its active metabolite.

3,4-Methylenedioxyamphetamine↗
PubMed1998

[Abuse of "pheticol" and its interference to the analysis of methamphetamine].

The study was to eliminate interference from ephedrine in the analysis of methamphetamine. The extraction procedure for methamphetamine was modified to include an oxidation step (2 ml urine specimen was treated with 0.5 ml of 1 mol/L phosphate buffer (pH 6.8) and 0.5 ml 0.3 mol/L sodium periodate). Results showed that ephedrine could be oxidized in the presence of periodate ions into smaller fragments while leaving methamphetamine intact. It is recommended that specimens be treated with sodium periodate prior to extraction in order to eliminate any interference caused by ephedrine.

Central Nervous System Stimulants↗
PubMed1997

[Analysis and assessment of meperidine and normeperidine concentrations in urine].

In this study, urine concentrations of meperidine and normeperidine after a single therapeutic dose of meperidine in 5 healthy volunteers have been measured and compared the results to those in meperidine addicts. The results showed that there was a significant difference between two groups in the ratio of metabolite to parent drug. If can be concluded that the ratio should be aid in making a cause of meperidine injection.

Adult↗