A systematic review and net meta-analysis of the effects of different warm-up methods on the acute effects of lower limb explosive strength.

OBJECTIVE: To evaluate the effects of different warm-up methods on the acute effect of lower limb explosive strength with the help of a reticulated meta-analysis system and to track the optimal method. METHODS: R software combined with Stata software, version 13.0, was used to analyse the outcome metrics of the 35 included papers. Mean differences (MD) were pooled using a random effects model. RESULTS: 1) Static combined with dynamic stretching [MD = 1.80, 95% CI: (0.43, 3.20)] and dynamic stretching [MD = 1.60, 95% CI: (0.67, 2.60)] were significantly better than controls in terms of improving countermovement jump height (cm), and the effect of dynamic stretching was influenced by the duration of stretching (I2 = 80.4%), study population (I2 = 77.2%) and age (I2 = 75.6%) as moderating variables, with the most significant effect size for dynamic stretching time of 7-10min. 2) Only dynamic stretching [MD = -0.08, 95% CI: (-0.15, -0.008)] was significantly better than the control group in terms of improving sprint time (s), while static stretching [MD = 0.07, 95% CI: (0.002, 0.13)] showed a significant, negative effect. 3) No results were available to demonstrate a significant difference between other methods, such as foam axis rolling, and the control group. CONCLUSION: The results of this review indicate that static stretching reduced explosive performance, while the 2 warm-up methods, namely dynamic stretching and static combined with dynamic stretching, were able to significantly improve explosive performance, with dynamic stretching being the most stable and moderated by multiple variables and dynamic stretching for 7-10min producing the best explosive performance. In the future, high-quality studies should be added based on strict adherence to test specifications.

[Mutation characteristics of osteosarcoma: a single center study of 64 cases using next-generation sequencing].

Objective: To investigate the distribution and characteristics of gene mutations in osteosarcoma, and to analyze the frequency and types of detectable mutations, and to identify potential targets for individualized treatment of osteosarcoma. Methods: The fresh tissue or paraffin-embedded tissue samples of 64 cases of osteosarcoma that were surgically resected or biopsied and then subject to next generation sequencing, were collected from Beijing Jishuitan Hospital, China from November 2018 to December 2021. The tumor DNA was extracted to detect the somatic and germline mutations using targeted sequencing technology. Results: Among the 64 patients, 41 were males and 23 were females. The patient age ranged from 6 to 65 years with a median age of 17 years, including 36 children (under 18 years old) and 28 adults. There were 52 cases of conventional osteosarcoma, 3 cases of telangiectatic osteosarcoma, 7 cases of secondary osteosarcoma, and 2 cases of parosteosarcoma. The detection rate of gene mutations was overall 84.4% (54/64). There were 324 variations in 180 mutated genes, including 125 genes with copy number variations, 109 single nucleotide variants, 83 insertions or deletions, and 7 gene fusions. The most common mutated genes were TP53, VEGFA, CCND3, ATRX, MYC, RB1, PTEN, GLI1, CDK4 and PTPRD. Among them, TP53 had the highest mutation rate (21/64, 32.8%), single nucleotide variant was the main mutation type (14/23, 60.9%), and 2 cases carried the TP53 germline mutation. VEGFA and CCND3 showed copy number amplification simultaneously in 7 cases. Conclusions: The high-frequency mutation of TP53 suggests that it plays an important role in the pathogenesis and development of osteosarcoma. VEGFA, CCND3 and ATRX are mutated genes in osteosarcoma and worthy of further studies. Combination of pathologic diagnosis and next generation sequencing with clinical practice can guide individualized treatment for patients with refractory, recurrent and metastatic osteosarcoma.

[The necessity and urgency of molecular analysis in the diagnosis and treatment of bone and soft tissue sarcomas].

Bone and soft tissue sarcomas are rare malignancies that present challenges in diagnosis and treatment. With the development of molecular technology, especially the popularization of next-generation sequencing (NGS) technology in the field of tumor, the diagnosis of some bone and soft tissue sarcomas have changed due to new evidence, and the treatment strategy has been adjusted accordingly. Molecular technology is expected to be an important tool of diagnosis and treatment strategy in the future. However, it has not been widely used in the fields of sarcoma, there are still many problems. Based on the data of literatures, the basic research, diagnosis, treatment, prognosis and existing problems of molecular analysis in sarcoma are discussed in this article.

[Reassessment of EWSR1 gene rearrangement-negative undifferentiated round cell sarcomas in bone and soft tissues by fluorescence in situ hybridization].

Objective: To unravel the CIC rearrangement sarcomas and BCOR-CCNB3 sarcomas from EWSR1 rearrangement-negative undifferentiated round cell sarcomas in the bone and soft tissues. Methods: Twenty-eight cases of EWSR1 rearrangement-negative undifferentiated round cell sarcomas of bone and soft tissues, tested for CIC rearrangement and BCOR rearrangement by fluorescence in situ hybridization and related immunostaining were analyzed, and some of the BCOR rearrangement cases were verified by reverse transcription-polymerase chain reaction. Results: Five of 28 (17.9%) tested cases were positive for CIC rearrangement and six (21.4%) for BCOR rearrangement. Histopathologically, CIC rearrangement sarcomas comprised nodular aggregates of round to polygonal cells, containing hyperchromatic nuclei, prominent nucleoli and moderate cytoplasm, with focal variable necrosis and myxoid stroma. BCOR-CCNB3 sarcomas mostly comprised diffusely arranged, round to oval to short spindly cells with angulated nuclei, vesicular chromatin, inconspicuous nucleoli and interspersed vessels. Immunohistochemically, five of six BCOR-CCNB3 sarcomas showed CCNB3 immunostaining, which could be helpful for diagnosis. Two patients with CIC rearrangement sarcoma died of the diseases in seven months and twenty-two months. One patient with BCOR-CCNB3 sarcoma died of the diseases in forty-six months. Conclusions: Overall, 39.3% of the EWSR1 rearrangement-negative undifferentiated round cell sarcomas are CIC rearrangement sarcomas and BCOR-CCNB3 sarcomas. Molecular testing is helpful for diagnosis.

[Liver failure and glucocorticoid resistance].

The main pathogenesis of liver failure is immune damage and uncontrolled inflammatory response. Glucocorticoids have strong immunosuppressive and anti-inflammatory effects, and are considered to be useful for the treatment of liver failure. However, the results of many clinical studies have shown that the application of glucocorticoids in patients with liver failure cannot effectively improve the prognosis, but instead increases the chance of infection and endangers life. Provided that, it seems reasonable to assume that glucocorticoid resistance exists in patients with liver failure. This article analyzes the mechanism by which P-glycoprotein reverses glucocorticoid transport, intracellular glucocorticoid signaling pathway dysfunction and related gene mutations when the inflammatory response is uncontrolled. In addition, we also evaluated the sensitivity of glucocorticoids in patients with liver failure, so as to provide theoretical basis for efficacy and medication timing.

[Effectiveness and safety of polyethylene glycol liposome doxorubicin in the treatment of osteosarcoma].

Objective: To evaluate the efficacy and safety of polyethylene glycol liposome doxorubicin (PLD) in the treatment of osteosarcoma. Methods: This study was a single-center retrospective clinical study. Two hundreds and seventy-six classical osteosarcoma treated in Beijing Jishuitan Hospital from 2015 to 2016 were enrolled. There were 213 patients who received combined chemotherapy of high dose methotrexate, ifosfamide, cisplatin and doxorubicin (ADM) were classified in ADM group. Other 63 patients received the same types, doses and cycles of chemotherapy drugs except ADM replaced by PLD were identified as PLD group. Clinical and imaging evaluation and surgical treatment were performed after neoadjuvant chemotherapy. Tumor necrosis rate was examined according to Huvos method. The efficacy of neoadjuvant chemotherapy was evaluated based on 90% necrosis rate. The recurrence, metastasis and survival were followed up regularly after operation. The adverse reactions of hematology, hepatorenal toxicity, gastrointestinal reaction and cardiotoxicity were evaluated. Results: There were no significant differences between PLD group and ADM group in age, sex, location, stage and surgical margin (all P>0.05). There were no significant differences in clinical symptoms and imaging evaluation between PLD group and ADM group after preoperative chemotherapy (all P>0.05). The tumor necrosis rate was detected in 134 cases. Among 27 cases of PLD group, tumor necrosis rates more than 90% were 11 cases, while among 107 cases of ADM group, tumor necrosis rates more than 90% were 45 cases. No significant difference of tumor necrosis rate between this two group was observed (P=0.901). The recurrence rates of PLD group and ADM group were 7.8% (4/51) and 7.3% (12/164), the metastasis rates were 19.6% (10/51) and 16.5% (27/164), the median progression free survival (PFS) were 42 and 37 months, respectively, without significant differences (all P>0.05). The incidence of granulocytopenia and decrease degree of granulocytes in PLD group were significantly lower than those in ADM group (P<0.001). There were no significant differences in the incidences of thrombocytopenia, anemia, gastrointestinal reaction, liver function damage and stomatitis between two groups (all P>0.05). Conclusions: PLD and ADM have similar chemotherapeutic effects in osteosarcoma. The incidences of adverse reactions of PLD are lower, especially the hematological toxicity represented by granulocytopenia is significantly reduced. PLD has a better application prospect.

[Autophagy in the liver failure].

Liver failure is a severe liver disease syndrome, with massive or sub-massive liver tissues necrosis, and it develops rapidly, with poor clinical prognosis and high mortality. In recent years, autophagy role in the liver failure has received increasing attention. The study of the role of regulatory mechanism of autophagy is of great significance for the in-depth study of the prevention and treatment of liver failure. Based on the research progress of liver failure at home and abroad, this paper explores and summarizes the relationship between autophagy with necrosis and apoptosis, as well as the mechanism and expression level of autophagy in each stage of liver failure, with hope to provide reference for the in-depth research and clinical treatment of liver failure.

3D-QSAR analysis of a series of S-DABO derivatives as anti-HIV agents by CoMFA and CoMSIA.

In this study, we retrieved a series of 59 dihydroalkylthio-benzyloxopyrimidine (S-DABO) derivatives, which is a class of highly potent HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) reported from published articles, and analysed them with comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Statistically significant three-dimensional quantitative structure-activity relationship (3D-QSAR) models by CoMFA and CoMSIA were derived from a training set of 46 compounds on the basis of the rigid body alignment. Further, the predictive ability of the QSAR models was validated by a test set of 13 compounds. Based on the information derived from CoMFA and CoMSIA contour maps, we have identified some steric and electrostatic features for improving the activities of these inhibitors, and we validated the 3D-QSAR results by a molecular docking method. On the basis of the obtained results, we designed a new series of S-DABO derivatives with high activities. Therefore, this study could be utilized to design more potent S-DABO analogues as anti-HIV agents.

Expression analysis of KAP9.2 and Hoxc13 genes during different cashmere growth stages by qRT-PCR method.

Keratin-associated protein 9.2 (KAP9.2) and Homeobox C13 (Hoxc13) genes were chosen to study because of their biological functions involving hair formation. KAP9.2 gene belongs to the ultra high sulfur KAPs, which is important for hair formation and may have association with cashmere. Hoxc13 takes part in the formation of cashmere keratin and maintaining the normal structure of follicle. It has been reported that Hoxc13 gene exists binding site of KP and KAP genes at its promoter regions in mouse. So the expression of KAP9.2 and Hoxc13 genes was detected at anagen stage vs telogen stage by qRT-PCR. The data showed that KAP9.2 and Hoxc13 gene had similar expression trend at different stages, which indicated that there was interaction between them. KAP9.2 and Hoxc13 gene had lower expression level in anagen than that of in telogen of cashmere growth. In anagen, KAP9.2 and Hoxc13 expressed lower in high cashmere yield individuals than that of in low cashmere yield ones. In telogen, the result was reverse. The study would provide the evidence of involvement of KAP9.2 and Hoxc13 in hair periodic growth.

Molecular analysis and frequency of Staphylococcus aureus virulence genes isolated from bloodstream infections in a teaching hospital in Tianjin, China.

Staphylococcus aureus is an important cause of bloodstream infections worldwide. We examined the prevalence of genes that encode erythromycin ribosome methylase and bacterial toxins in S. aureus collected from bloodstream infections. Sixty different S. aureus isolates were obtained from blood cultures of patients who were admitted to a Teaching Hospital in Tianjin from January 2006 to August 2011. The susceptibility of the isolates to 16 antibiotics was tested. Methicillin-resistant S. aureus (MRSA) was identified using the disk diffusion method with cefoxitin. PCR was used to detect genes that encode the staphylococcal enterotoxins, Panton-Valentine leukocidin, toxic shock syndrome toxin 1 and erythromycin ribosome methylase. Molecular analysis of the MRSA strains was done using pulsed-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome mec (SCCmec) typing. The positivity rates of mecA, ermA, ermB, and ermC in the isolates were 13/60, 10/60, 18/60, and 18/60, respectively. Among the 60 isolates, 30 harbored enterotoxin genes, with sea as the most frequent toxin gene (33%), followed by sec (15%), sed (12%), and seb (5%). The see and tst genes were not found in any of the isolates. The pvl gene was detected in four strains. Eleven MRSA isolates were of the SCCmec type III; two MRSA isolates could not be determined through SCCmec typing. PFGE analysis of the 13 MRSA isolates produced 8 distinct pulsotypes. Virulence genes and erythromycin ribosome methylase genes were highly prevalent in these isolates. The PFGE results demonstrated that the MRSA spread through cloning, mainly involving SCCmec type III.

Liquid chromatography-mass spectrometry method for the quantification of posaconazole in human plasma: application to pharmacokinetics following single-dose administration in the fasted state and with a high-fat meal.

A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed to determine concentrations of posaconazole in human plasma precipitated by acetonitrile including internal standard. Rapid chromatographic separation was achieved in the mobile phase composition of acetonitrile, water and formic acid (v/v/v, 55:45:0.1) with a flow rate of 0.25 ml/min. Posaconazole-d4 was used as internal standard. Detection was undertaken with cation electrospray tandem mass spectrometry on a Sciex/API3000. The method was accurate, specific and sensitive for the analysis of posaconazole in human plasma in the concentration range of 2-1000 ng/ml. The inter- and intra-batch accuracy was within +/- 10% and the lower limit of quantification was 2 ng/ml. The method facilitated a clinical pharmacokinetic study after oral administration of a single-dose of posaconazole suspension in the fasted state and with a high-fat meal in a two-period crossover design. Cmax (maximum concentration) and AUC (area under serum drug concentration) were significantly increased, and Tmax (time to maximum plasma concentration) was delayed under fed condition, which suggested that simultaneous administration of posaconazole with food may help to achieve higher plasma concentrations and result in better antifungal efficacy.

Dose-dependent pharmacokinetics of bulleyaconitine A in rats.

This study was conducted to determine the pharmacokinetic characteristics of bulleyaconitine A (BLA) after oral gavage and intravenous administration of BLA at a single dose of 0.04, 0.12, 0.36 mg/kg (oral) or 0.02 mg/kg (i.v.) in male Sprague-Dawley rats. Plasma concentration profiles were analysed using a non-compartmental pharmacokinetic method. Following i.v. 0.02 mg/kg and oral administration 0.04, 0.12 or 0.36 mg/kg, the geometric mean Cmax values were 19.97, 2.11, 5.11 and 11.47 ng/ml, respectively; the corresponding geometric mean AUC(0-t) values were 10.50, 3.19, 9.59 and 18.10 ng x h/ml, respectively. The median Tmax values were 0.033, 0.167, 0.167 and 0.167 h, respectively. The terminal elimination half-lives (t1/2) were 1.23, 2.48, 1.93 and 2.17h, respectively. The results showed that Cmax and AUC(0-t) increased with increasing doses of BLA. The increase in exposure with increasing dose was lower than expected under conditions of strict proportionality.

Variation and expression of KAP9.2 gene affecting cashmere trait in goats.

Keratin-associated proteins 9.2 (KAP9.2) gene encodes one of the ultra high sulfur KAPs. Variation in KAP genes may affect the structure of KAPs and hence cashmere characteristics. In order to test the association between the polymorphism of KAP9.2 gene and cashmere trait, DNA sequencing was used to detect a novel C/T polymorphism of KAP9.2 gene from a genomic DNA pool. The mutation could be recognized by Pst I restriction enzyme. To Shanbei white cashmere goat, Inner Mongolia white cashmere goat and Guanzhong dairy goat, the genotypic frequencies of TT, TC and CC from total 1,236 animals were as follows: 0.047, 0.519 and 0.434; 0.180, 0.592 and 0.228; 0.431, 0.544 and 0.025. The allelic frequencies of T and C were 0.307 and 0.693; 0.476 and 0.524; 0.703 and 0.297, respectively, in breeds mentioned above. The frequency of C allele between cashmere and dairy goat was significant (P < 0.01). To provide support for the hypothesis that SNP 586 was responsible for KAP9.2 expression, quantitative real-time PCR analysis revealed that the expression level of KAP9.2 was reduced in individuals bearing genotype CC compared with TT individuals, suggesting that C was the nucleotide causing decreased expression of KAP9.2 or was in linkage disequilibrium with the causative SNP. The 586C/T SNP found in this study might control translation or stability of KAP9.2 mRNA, which would be beneficial for marker assistant selection in cashmere goat breeding.

The difference in pharmacokinetics and pharmacodynamics between extended-release fluvastatin and immediate-release fluvastatin in healthy Chinese subjects.

The aim of this study was to evaluate the difference in pharmacokinetics and pharmacodynamics between extended-release (ER) fluvastatin tablet and its immediate-release (IR) capsule in Chinese healthy subjects. This was an open-label, single/multiple-dose, two-period, two-treatment, crossover, randomized trial with a minimum washout period of 7 days. Twenty healthy male adult subjects were given fluvastatin ER tablet 80 mg QD by oral administration or fluvastatin IR capsule 40 mg BID for seven days. Blood samples were collected up to 24 hours after dosing on day 1 and day 7. Serum concentrations of fluvastatin were determined by LC-MS/MS. For fluvastatin ER tablet 80 mg QD, C(max) was 61.0 ± 39.0 and 63.9 ± 29.7 ng/mL, and AUC(0-24 h) was 242 ± 156 and 253 ± 91.1 ng·h/mL on day 1 and 7, respectively. For fluvastatin IR capsule 40 mg BID, C(max) was 283 ± 271 and 382 ± 255 ng/mL, and AUC(0-24 h) was 720 ± 776 and 917 ± 994 ng·h/mL on day 1 and day 7, respectively. The relative bioavailability of fluvastatin ER tablet 80 mg QD to fluvastatin IR capsule 40 mg BID is (45.3 ± 23.9)% and (43.3 ± 24.1)% on day 1 and day 7, respectively. T(max) for fluvastatin ER tablet was 2.50 and 2.60 h and for capsule was 0.78 and 0.88 h on day 1 and day 7, respectively. In the first period, compared to baseline, cholesterol decreased 15.3% in fluvastatin ER tablet 80 mg QD and 16.9% in fluvastatin IR capsule 40 mg BID. Triglyceride decreased 3.7% in fluvastatin ER tablet 80 mg QD and 19.1% in fluvastatin IR capsule 40 mg BID. The difference has no statistical significance at P > 0.05 in reduction percent of cholesterol and triglyceride between the two groups. No adverse events were recorded. The results indicated that C(max) of fluvastatin ER tablet is reduced and T(max) is prolonged compared with IR capsule. There is no accumulation for ER formulation after multiple doses.

Ultrathin single-crystal ZnO nanobelts: Ag-catalyzed growth and field emission property.

We report the growth of ultrathin single-crystal ZnO nanobelts by using a Ag-catalyzed vapor transport method. Extensive transmission electron microscopy and atomic force microscopy measurements reveal that the thickness of the ultrathin ZnO nanobelts is approximately 2 nm. Scanning electron microscopy and post-growth annealing studies suggest a '1D branching and 2D filling' growth process. Our results demonstrate the critical role of catalyst in the deterministic synthesis of nanomaterials with the desired morphology. In addition, these ultrafine nanobelts exhibit stable field emission with unprecedented high emission current density of 40.17 mA cm(-2). These bottom-up building blocks of ultrathin ZnO nanobelts may facilitate the construction of advanced electronic and photonic nanodevices.

Determination of chiglitazar, a dual alpha/gamma peroxisome proliferator-activated receptor (PPAR) agonist, in human plasma by liquid chromatography-tandem mass spectrometry.

Chiglitazar is a dual alpha/gamma peroxisome proliferator-activated receptor (PPAR) agonist. A LC-MS/MS method for the determination of chiglitazar was developed and validated. The assay used 0.2 mL of plasma. 90% acetonitrile containing internal standard was used for protein precipitation. The mobile phase contained 70/30 (v/v) of methanol and water at a flow rate of 0.25 mL/min. Detection was by negative ion electrospray tandem mass spectrometry on a Sciex API 3000. The standard curve, which ranged from 2 to 1500 ng/mL, was fitted to a 1/x weighted quadratic regression model. The validation results demonstrated that the method was sensitive, rapid, selective and robust and provided satisfactory precision and accuracy. The method has been successfully used for the analysis of clinical samples in pharmacokinetic studies of chiglitazar.

Pharmacokinetics and safety of recombinant human parathyroid hormone (1-34) (teriparatide) after single ascending doses in Chinese healthy volunteers.

The pharmacokinetics and safety of recombinant human parathyroid hormone (1-34) [rhPTH (1-34)] after single ascending doses were evaluated in Chinese healthy volunteers. Nine healthy volunteers (five male and four female) were recruited for an open label, randomized, three multiply three crossover, single ascending dose (10, 20, and 40 microg) study. Using a validated radioimmunoassay, we determined the plasma concentrations of rhPTH (1-34). The mean peak plasma concentration (Cmax) were 123.6, 195.6, and 318.2 pg x mL(-1) respectively, and were reached from 25.6 to 36.1 min after subcutaneous administration. After Cmax was reached, the plasma drug level decreased quickly, with elimination halflife (t(1/2)) of 53.9 to 64.1 min. The mean AUC(0-infinity) (the area under the plasma concentration versus time curve from time zero to infinite) of rhPTH (1-34) were 11794.2 +/- 974.8, 21606.7 +/- 4753.9, 33877.0 +/- 8374.4 pg x min x mL(-1), respectively. The mean AUC(0-t) (the area under the plasma concentration versus time curve from time zero to the last quantifiable concentration) of rhPTH (1-34) were 9034.4 +/- 1073.9, 17883.3 +/- 4597.1, 31693.5 +/- 6574.8 pg x min x mL(-1), respectively. Dose-related linear trend were observed for AUC(o-t) and Cmax of rhPTH (1-34). t(1/2) and Tmax (time to Cmax) of rhPTH (1-34) were independent of administered dose. rhPTH (1-34) was safe and well tolerated by all volunteers.

Is flow cytometry really adapted to the determination of sperm concentration?

It has been reported that flow cytometry can be used as a reference procedure to determine sperm concentrations in quality control schemes in andrology laboratories, but there are no convincing quality control data. To understand comprehensively whether flow cytometry can be used to determine sperm concentration, sperm concentrations of 85 human semen samples were detected using three different methods, namely flow cytometry, computer-assisted semen analysis (CASA) and manual counting with a cell-VU chamber. The bead concentrations of both low [(18+/-2.5)x10(6)/mL] and high [(35+/-5)x10(6)/mL] pre-calibrated standard latex bead solutions were also determined with flow cytometry. The results showed that bead concentrations of both low and high pre-calibrated standard latex bead solutions counted five times with flow cytometry were (21.37+/-0.85)x10(6)/mL and (45.95+/-1.76)x10(6)/mL, respectively. Coefficient variances (CVs) and relative errors (REs) were 4%, 15.51% and 3.84%, 31.3% for low and high latex bead solutions, respectively. The overall correlation between values measured with flow cytometry and values measured with the cell-VU chamber and the CASA system was significant. However, flow cytometry overestimated the sperm concentration by 109% compared to the results with the cell-VU chamber. Moreover, for the azoospermic samples analysed, the sperm concentration was estimated at 0.12 (range from 0.04 to 0.24)x10(6)/mL. In conclusion, the data demonstrated that flow cytometry can result in an overestimation of both bead counting and sperm concentration, suggesting that flow cytometry is an inappropriate method for sperm counting, especially in the case of azoospermia.

Preliminary investigations on the standardisation and quality control for the determination of gamma-glutamyltranspeptidase activity in seminal plasma.

The present study was designed to assess the effects of centrifugation velocity, standing time after dilution, freezing-thawing and chymotrypsin on the determination of gamma-glutamyltranspeptidase (gamma-GT) activities in seminal plasma, and to establish an instruction for the standardisation and quality control for the determination of gamma-GT within the same laboratory and among different laboratories. The gamma-GT level and sperm concentration of each of 72 samples of seminal plasma obtained by centrifugation at 1000 g for 10 min or 3000 g for 15 min were assayed. In addition, gamma-GT activities in diluted seminal plasma with different standing time and in samples with or without chymotrypsin were measured. The results showed that there was a significant difference of gamma-GT levels in seminal plasma obtained by centrifugation at different velocities (P < 0.001), and that gamma-GT activities in seminal plasma measured after standing for 30 min after dilution were notably lower than those measured immediately after dilution (P < 0.001). However, the data indicated that both chymotrypsin and freezing-thawing had no apparent effect on the determination of seminal gamma-GT. In conclusion, standing time after dilution and centrifugation velocity should be standardised, and frozen seminal plasma could serve as quality control products for the determination of gamma-GT activity among different laboratories.