Comparison of Pregnancy and Neonatal Outcomes Between Fresh Embryo Transfer and Frozen-Thawed Embryo Transfer.

This study compared the pregnancy and neonatal outcomes between fresh embryo transfer and frozen-thawed embryo transfer (FET). These patients were split into two groups: the fresh embryo transfer group and the FET group. The general conditions, pregnancy outcomes, and neonatal outcomes between these groups were compared. The influencing factors of fetal macrosomia occurrence were explored as well. Compared with the fresh embryo transfer group, the FET group had a significantly higher mean age (32.59 ± 4.77 vs. 31.90 ± 4.71, p < 0.05) and lower multiple pregnancy rate (21.2% vs. 26.9%, p < 0.05). There was no significant difference in the incidence of congenital anomalies of neonates between the two groups (1.32% vs. 0.37%, p > 0.05). In the FET group, compared with the fresh embryo transfer group, the mean birth weight of singleton live births, the cesarean section rate, and the incidence of fetal macrosomia were significantly increased, while the incidence of low birth weight was significantly decreased. The logistic analysis showed that the occurrence of fetal macrosomia was primarily associated with the embryo transfer protocol (odds ratio [OR] = 2.769, 95% confidence interval [CI]: 1.246-6.154, p < 0.05), endometrial thickness (OR = 1.144, 95% CI: 1.043-1.256, p < 0.05), and gestational age (OR = 1.710, 95% CI: 1.338-2.184, p < 0.05). Macrosomia (OR = 2.938, 95% CI: 1.436-6.010, p = 0.003) and multiple pregnancy (OR = 3.574, 95% CI: 2.616-4.882, p < 0.001) significantly increased the cesarean section rate. The risk of fetal macrosomia and congenital anomalies in the offspring of the fresh embryo transfer group was lower than that in the offspring of the FET group, we preferred to fresh embryo transfer for patients with assisted reproductive technologies. FET should be used as supplementary therapeutic strategy with strengthened pregnancy management and screening to reduce the occurrence of birth defects in newborns.

Blocking P2X4 purinergic receptor attenuates alcohol-related liver fibrosis by inhibiting hepatic stellate cell activation through PI3K/AKT signaling pathway.

Alcoholic liver fibrosis（ALF）, as a liver disease caused by long-term alcoholism, attracts international attention. Activation of hepatic stellate cells is a key step in the development of alcoholic-associated liver fibrosis. Increasing studies have shown that P2X4 receptor, as a component of purinoceptor family in adenosine pathway, plays an important role in numerous liver diseases. In this study, it was found that the expression of P2X4 receptor was significantly increased in the mouse liver fibrosis model fed with ethanol plus CCL4 and in the HSC-T6 cell model stimulated by acetaldehyde. In vivo, C57BL/6J mice were used to establish ALF models, and 5-BDBD, a specific inhibitor of P2X4 receptor, was injected intraperitoneally at 6-8 weeks of ALF development. The results indicated that 5-BDBD could reduce the expression of fibrotic markers and attenuate the pathological features of fibrosis, thus demonstrating the alleviation of ALF.In vitro, PI3K/AKT pathway was activated in HSC-T6 cells stimulated by acetaldehyde. Silencing P2X4 receptor or administration of 5-BDBD could inhibit the phosphorylation of PI3K and AKT, thereby inhibiting the activation of HSC-T6 cells. In addition, 5-BDBD was administered to RAW264.7 cells activated by acetaldehyde, and then part of the supernatant was added to HSC-T6 cells culture medium. The results showed that 5-BDBD could reduce the expression of classical inflammatory pathways such as TGF-ß pathway in RAW267.4 cells, thus inhibiting the activation of HSC-T6 cells. Taken together, these results suggest that P2X4 receptors may influence the progression of alcohol-related liver fibrosis by directly mediating the PI3K/AKT pathway, or indirectly by influencing RAW264.7 cells to regulate hepatic stellate cell activation.

Shufeng Jiedu capsule inhibits inflammation and apoptosis by activating A2AAR and inhibiting NF-κB to alleviate LPS-induced ALI.

ETHNOPHARMACOLOGICAL RELEVANCE: Shufeng Jiedu capsule (SFJDC) is a pure form of traditional Chinese medicine (TCM) that contains eight medicinal plants. Known for its anti-inflammatory and antipyretic effects, it is mostly used to treat upper respiratory tract infections and other infectious diseases, such as colds, pharyngitis, laryngitis, and tonsillitis. Both acute lung injury (ALI) and COVID-19 are closely related to lung damage, primarily manifesting as lung inflammation and epithelial cell damage. However, whether SFJDC can improve ALI and by what mechanism remain unclear. The purpose of this study was to explore whether SFJDC could be used as a prophylactic treatment for COVID-19 by improving acute lung injury. AIM OF THE STUDY: The purpose of this study was to determine whether SFJDC could protect against ALI caused by lipopolysaccharide (LPS), and we wanted to determine how SFJDC reduces inflammation and apoptosis pharmacologically and molecularly. MATERIALS AND METHODS: Preadministering SFJDC at 0.1 g/kg, 0.3 g/kg, or 0.5 g/kg for one week was followed by 5 mg/kg LPS to induce ALI in mice. Observations included the study of lung histomorphology, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) secretion, as well as the ratio of lung wet/dry weights. In addition, RAW264.7 cells were treated for 24 h with 1 µg/mL LPS after being pretreated for 1 h with 0.5 mg/mL SFJDC. In the samples, we detected TNF-α, IL-1ß, and IL-6. Cell apoptosis was detected by stimulating A549 cells for 24 h with RAW264.7 supernatant. Both in vitro and in vivo, the levels of A2A adenosine receptor (A2AAR), PKA, IκB, p-IκB, NF-κB P65 (P65), p-NF-κB P65 (p-P65), cleaved caspases-3 (Cc3), Bcl-2 associated X protein (Bax), and B-cell lymphoma-2 (Bcl-2) proteins were determined using Western blot analysis. RESULTS: Lung tissue morphology was improved as SFJDC decreased cytokine secretion, the ratio of lung wet/dry weights, and lung tissue secretion of proinflammatory cytokines. The expression of A2AAR was increased by SFJDC, and the phosphorylation of NF-κB was inhibited. TUNEL staining and flow cytometry showed that SFJDC inhibited apoptosis by reducing the expression of Cc3 and the ratio of Bax/Bcl-2. CONCLUSIONS: According to the results of this study, SFJDC can reduce inflammation and inhibit apoptosis. A2AAR activation and regulation of NF-κB expression are thought to make SFJDC anti-inflammatory and anti-apoptotic. A wide range of active ingredients may result in an anti-inflammatory and antipyretic effect with SFJDC.

[The Establishment and Identification of Acute Myeloid Leukemia NOD-SCID-IL2rg-/-Mice Model by Using Luciferase-Expressing KG1a Cells].

OBJECTIVE: To establish the in vivo traceable acute myeloid leukemia mice model with Luciferase-Expressing KG1a Cells. METHODS: KG1a cells with stable luciferase gene expression (called as KG1a-Luc cells) were constructed by lentivirus transfection, then sifted out by puromycin. Eighteen male NOD-SCID-IL2rg-/-mice aged 8 to 12 weeks were randomly and equally divided into two groups: the control group and the KG1a-Luc group. The mice in KG1a-Luc group were injected with 200 µl PBS containing 5×106 KG1a-Luc cells through tail veins, and the mice in control group were injected with 200 µl PBS only. The bioluminescence imaging technology was used to monitor the tumor burden in vivo. The peripheral blood of the mice in both groups was analyzed by flow cytometry. After the mice were sacrificed, there were pathologic evaluations: bone marrow and spleens made into smears, and livers sliced to get paraffin sections. The survival time of the mice in the two groups was recorded and compared. RESULTS: KG1a cells expressing luciferase stably were successfully obtained. The tumor luminescence wildly spread at day 17 captured by in vivo imaging. The KG1a-Luc tumor cells could be detected in the peripheral blood of the mice, with the average percentage of (16.27±6.66)%. The morphology and pathology result showed that KG1a-Luc cells infiltrate was detected in bone marrow, spleens and livers. The survival time of the KG1a-Luc mice was notably shorter as compared with those in the control group, the median survival time was 30.5 days (95%CI: 0.008-0.260). CONCLUSION: The acute myeloid leukemia NOD-SCID-IL2rg-/-mouse model was successfully established by tail vein injection of 5×106 KG1a-Luc cells.

Design of bovine lactoferricin-derived peptide and its expression and activity in Pichia pastoris.

Bovine lactoferrin peptide has been shown to be a broad-spectrum antimicrobial peptide. Based on the relationship between the structure and function of antimicrobial peptides, the antimicrobial peptide databases and protein analysis software were used to optimize the design of bovine lactoferricin peptide (LfcinB). The designed bovine lactoferricin-derived peptide (LfcinBD) gene fragment was inserted into a pPIC9K-His plasmid to construct a recombinant expression vector. After linearization of the Recombinant plasmid, Pichia pastoris GS115 cells were transfected with linearized recombinant plasmid by using electroporation and LfcinBD gene expression was induced with methanol. After the fermentation, supernatant was separated by low-temperature high-speed centrifugation. Ultrafiltration and freeze drying of the fermentation supernatant were performed, purified. Experimental results showed that the LfcinBD had stronger bacteriostatic activity against Staphylococcus aureus than the natural bovine lactoferrin peptide (LfcinB) produced under the same fermentation conditions. The effective expression of the optimized bovine lactoferricin-derived peptide was detected using SDS-PAGE electrophoresis. This study lays the foundation for further exploration to improve the biological activities of antimicrobial peptides.

[Regulatory Effect of Exosomes Derived from Human Umbiilcal Cord Mesenchymal Stem Cells on Treg and TH17 Cells].

OBJECTIVE: To investigate the effects of exosomes from human umbilical cord mesenchymal stem cells on the development of Treg and TH17 cells. METHODS: Exosomes from the serum-free-culture supernatants of hUC-MSC were harvested by ultracentrifugation. The electron microscopy, nanoparticle tracking analysis and western blot were used to identify the hUC-MSC-exosomes, such as the morphology, the paticle chameter, and the protein content. The PBMC stimulated with anti-CD3/CD28 were incubated with the exosomes for five days, and then the percentage changes of Treg and TH17 cells were analyzed by using flow cytometry. RESULTS: The hUC MSC-derived exosomes were saucer-like in morphology the averge diameter was approximately 142 nm. They were identified as positive for CD9 and CD63. Flow cytometry showed that the proportion of CD4+CD25+Foxp3+ Treg cells in the PBMC were significantly higher, but the proportion of CD4+IL17A+ T cells in the hUC-MSC-exosome group was obviously lower than that in the group without the hUC-MSC-exosom (control group) (P<0.05). CONCLUSION: The hUC-MSC-exosomes have an immunomodulatory effect on T cells in vitro by increasing the ratio of Treg and reducing the ratio of TH17 cells, expecting the hUC-MSC-exosom as a novel cell-free target for immunotherapy.

[Effectiveness of CLAT Protocol for Treating Patients with Refractory Acute Myeloid Leukemia].

OBJECTIVE: To explore the clinical efficacy and toxicity of CLAT protocol (cladribine, cytarabine and topotecan) for treating patients with refractory acute myeloid leukemia (R-AML). METHODS: A total of 18 patients with R-AML (median age 37 years, range 18 to 58 years; male n = 16, female n = 2) were treated with CLAT protocol, which consisted of cladribine 5 mg/m(2)/d, i.v. on days 1-5, cytarabine 1.5 g/m(2)/d, i.v. on days 1-5, topotecan 1.25 mg/m(2)/d, i.v. on days 1-5 and G-CSF 300 µg/d subcutaneous injection on day 6 until neutrophile granulocyte recovery. RESULTS: Out of 18 patients 2 died of severe infection before the assessment. Among 16 evaluated patients, 10 (55.6%) achieved complete remission (CR), and 2 (11.1%) achieved partial remission (PR), the overall response rate was 66.7%, the rest 4 patients did not respond (NR). The median overall survival time and DFS for the CR patients was 9.5 months (95%CI: 6.7-16.64) and 9.5 months (95%CI: 6.1-16.7) respectively. The 1 year OS and DFS rates were 45% and 46.9%, respectively. All patients developed grade 4 of granulocytopenia and thrombocytopenia, the median duration was 13 (range 2 to 21) days and 12 days (range 2 to 21), respectively, all patients developed infection, 2 patients died of severe infection. The most common non-hematological side effects included nausea, vomiting, diarrhoea, rash, aminotransferase or bilirubin elevation and were grade 1 to 2. CONCLUSION: The CLAT protocol seems to have promising for the treatment of refractory AML patients, and patients well tolerated. This CLAT protocol offers an alternative treatment for R-AML patients who received severe intensive treatment, especially with anthracycline-containing chemotherapy.

Optimal waist circumference cut-off values for identifying metabolic risk factors in middle-aged and elderly subjects in Shandong Province of China.

OBJECTIVE: To study the optimal waist circumference (WC) cut-off values for identifying metabolic risk factors in middle-aged and elderly subjects in Shandong Province of China. METHODS: A total of 2,873 men and 5,559 women were included in this cross-sectional study. Metabolic syndrome (MetS) was diagnosed according to the definition of Chinese Diabetes Society in 2004. The relation between WC and MetS was analyzed by multivariate logistic regression analysis. The optimal WC cut-off values were identified using the area under the ROC curve and the different diagnostic criteria for central obesity were compared. RESULTS: The WC was the risk factor for MetS independent of BMI, blood glucose, blood lipid, and blood pressure. The optimal WC cut-off value was 83.8 cm and 91.1 cm for identifying MetS in women and men, respectively. Compared with 80 cm and 85 cm for women and men, 85 cm and 90 cm had a higher Youden index for identifying all metabolic risk factors and MetS in women and men. CONCLUSION: The appropriate WC cut-off value is 85 cm and 90 cm for identifying central obesity and MetS in women and men in Shandong Province of China.

Genotoxicity evaluation of Mequindox in different short-term tests.

Quinoxaline-1,4-dioxides (QdNOs) are the potent heterocyclic N-oxides with interesting biological properties such as antibacterial, anticandida, antitubercular, anticancer and antiprotozoal activities. Here, we tested and compared the mequindox (MEQ) for mutagenic abilities in a battery of different short term tests according to OECD guidelines. When compared with the controls, a strong mutagenicity of MEQ and carbadox (CBX) was observed with an approximate concentration-effect relationship in Salmonella reverse mutation test, chromosome aberration test, unscheduled DNA synthesis assay and HGPRT gene mutation test, in the absence and presence of S(9)-mix. In in vivo micronucleus test, CBX produced significant increase in the proportion of micronucleus formation than MEQ in mice bone marrow cells. From these results, we can conclude that MEQ had a strong genotoxic potential to mammalian cells in vitro as well as in vivo and its mutagenicity is slightly higher than CBX. Our results, for the 1st time, discuss the genotoxic potential of MEQ. These results not only confirm the earlier findings about CBX but also extend the knowledge and awareness about the genotoxic risk of QdNO derivatives.

Two generation reproduction and teratogenicity studies of feeding quinocetone fed to Wistar rats.

To investigate the reproductive toxicity and teratogenic potential of quinocetone, a growth promoting agent, Wistar rats were fed different diets containing 0, 50, 300 and 1800 mg/kg quinocetone or 300 mg/kg olaquindox. Groups of 15 males and 30 females (F(0)) were fed through a 10-week prebreed period as well as during mating, gestation, parturition and lactation. At weaning, 12 males and 24 females of F(1) generation weanlings per group were selected randomly as parents for F(2) generation. Selected F(1) weanlings were exposed to the same diet and treatment as their parents. At the highest quinocetone group, body weights in F(0) and F(1) rats, fetal body weight on day 21 after birth and number of viable fetuses in F(0) and F(1) generation significantly decreased. In teratogenicity study, groups of 12 males and 24 females were fed with the same diets through a 12-week prebreed period and matting periods. Pregnant rats were subjected to cesarean section on GD 20 for teratogenic examination. At the highest quinocetone group, body weights and feed efficiency, fetal body lengths, tail lengths, litter weights and number of viable fetuses significantly decreased. The NOAEL for reproduction/development of quinocetone for rats was estimated to be 300 mg/kg diet.

Two generation reproduction and teratogenicity studies of feeding cyadox in Wistar rats.

To investigate the teratogenic potential and reproductive toxicity of cyadox, a growth promoting agent, Wistar rats (F(0)) were fed with diets containing cyadox (0, 50, 150 and 2500 mg/kg) or olaquindox (150 mg/kg), approximately equivalent to cyadox 5, 15, 250 or olaquindox 15 mg/kg b.w./day across two generations. Half of the pregnant rats (F(0), F(1b)) were subjected to caesarean section on gestational day 20 for teratogenic examination and the other half produced pups F(1a) and F(2a), respectively. At the 250 mg/kg b.w./day cyadox group, body weights of F(1b) pregnant rats and F(2a) on day 21 after birth decreased; fetal body lengths and tail lengths decreased; the number of fetal resorptions increased significantly; litter weights, number of viable fetuses decreased; number of embryo resorptions increased significantly; number of liveborn F(1a), F(1b) and F(2a) decreased. No macroscopic or microscopic change of any significance was found in the reproductive organs. Significant increases in the incidence of cervical ribs or lumbar ribs in F(2a) pups and significant increases of relative organ weight of testis and epididymis in F(1b) were observed at the 250 mg/kg b.w./day cyadox group. The NOAEL for reproduction/development of cyadox for rats was estimated to be 150 mg/kg diet, which was equivalent to approximately 15 mg/kg b.w./day.

A chronic toxicity study of cyadox in Wistar rats.

To investigate the chronic toxicity of cyadox, a growth promoting agent, five groups of Wistar rats (30 rats/group/sex) were fed with the diets containing cyadox (0, 100, 400 and 2000 mg/kg) or olaquindox (400 mg/kg) for 78weeks. There were significant decreases in body weights in both genders during most of the study period in 2000 mg/kg cyadox and 400 mg/kg olaquindox rats. Significant decreases in serum alkaline aminotransferase in the 2000 mg/kg cyadox rats at weeks 26, 52 and 78 were observed. Relative weights of liver and kidney were significantly increased in 2000 mg/kg cyadox and 400 mg/kg olaquindox rats at weeks 26, 52 and 78. A significant increase in relative brain and heart weights in 2000 mg/kg cyadox males was observed. The histopathological examinations revealed that 2000 mg/kg cyadox diet or 400 mg/kg olaquindox diet could induce proliferation of bile canaliculi in the portal area of liver and swelling and fatty degeneration of the proximal renal tubular epithelial cells in kidneys. In conclusion, the target organs of cyadox for rats were liver and kidney. The no-observed-adverse-effect level of cyadox in this study was estimated to be 400 mg/kg diet.

Population pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in chicken based on retrospective data, incorporating first-pass metabolism.

A population pharmacokinetic (PPK) model for enrofloxacin and its metabolite ciprofloxacin in chicken based on retrospective data was developed. Plasma concentrations of enrofloxacin and its metabolite ciprofloxacin were determined in blood samples from chicken administered either enrofloxacin via oral and intravenous routes or ciprofloxacin via intravenous injection. The disposition of enrofloxacin and ciprofloxacin was described simultaneously by an integrated mathematic model. Two compartments were used to describe the enrofloxacin and ciprofloxacin disposition profiles. The formation of ciprofloxacin was through the central compartment of enrofloxacin. The integrated model was estimated with nonlinear mixed effects model (NONMEM). The total clearance of enrofloxacin (CLEN) and ciprofloxacin (CLCP) was 0.613 L/h and 1.15 L/h, respectively. Correlation between CLEN, the central compartment volume of distribution for enrofloxacin (V2) and CLCP was estimated. After intravenous administration of enrofloxacin, the transformation rate of enrofloxacin to ciprofloxacin was 0.429 L/h. The bioavailability factor after oral administration was 0.926, and 12.6% of enrofloxacin after oral administration was transformed to ciprofloxacin via first-pass effect. Pharmacodynamic (PD) evaluation was performed using area under concentration time curve of active moiety from 0 to 24 h and MIC collected from literature. This study is the first one to use PPK method to investigate parent drug and its metabolite disposition and PDs using an integrated model in veterinary medicine.

Application of electrospray ionization hybrid ion trap/time-of-flight mass spectrometry in the rapid characterization of quinocetone metabolites formed in vitro.

The application of electrospray ionization hybrid ion trap/time-of-flight mass spectrometry coupled with high-performance liquid chromatography (LC/MS-IT-TOF) in the rapid characterization of in vitro metabolites of quinocetone was developed. Metabolites formed in rat liver microsomes were separated using a VP-ODS column with gradient elution. Multiple scans of metabolites in MS and MS(2) modes and accurate mass measurements were automatically performed simultaneously through data-dependent acquisition in only a 30-min analysis. Most measured mass errors were less than 10 ppm for both protonated molecules and fragment ions using external mass calibration. The elemental compositions of all fragment ions of quinocetone and its metabolites could be rapidly assigned based upon the known compositional elements of protonated molecules. The structure of metabolites were elucidated based on the combination of three techniques: agreement between their proposed structure, the accurate masses, and the elemental composition of ions in their mass spectra; comparison of their changes in accurate molecular masses and fragment ions with those of parent drug or metabolite; and the elemental compositions of lost mass numbers in proposed fragmentation pathways. Twenty-seven phase I metabolites were identified as 11 reduction metabolites, three direct hydroxylation metabolites, and 13 metabolites with a combination of reduction and hydroxylation. All metabolites except the N-oxide reduction metabolite M6 are new metabolites of quinocetone, which were not previously reported. The ability to conduct expected biotransformation profiling via tandem mass spectrometry coupled with accurate mass measurement, all in a single experimental run, is one of the most attractive features of this methodology. The results demonstrate the use of LC/MS-IT-TOF approach appears to be rapid, efficient, and reliable in structural characterization of drug metabolites.

Long-term dose-dependent response of Mequindox on aldosterone, corticosterone and five steroidogenic enzyme mRNAs in the adrenal of male rats.

Mequindox (MEQ) is a synthetic quinoxaline 1,4-dioxides (QdNOs) derivative which can effectively improve growth and feed efficiency in animals. This study was to investigate the dose-dependent long-term toxicity in the adrenal of male rats exposed to 180 days of MEQ feed. Our data demonstrated that high doses of MEQ in the diet for 180 days led to adrenal damage and steroid hormone decrease, combined with sodium decrease and potassium increase in rat plasma. Significant changes of GSH and SOD in plasma were observed in the high doses (110, 275 mg/kg) groups. At the same doses, MEQ treatment down-regulated the mRNA levels of CYP11A1, CYP11B1 and CYP11B2 which located in mitochondria, but up-regulated mRNA levels of CYP21 and 3beta-HSD which located in endoplasmic reticulum. In conclusion, we reported the dose-dependent long-term toxicity of MEQ on adrenal gland in male rats, which raise awareness of its toxic effects to animals and consumers, and its mechanism may involve in oxidative stress and steroid hormone biosynthesis pathway.

[Study on the interaction between vincristine and bovine serum albumin].

The interaction between vincristine (VCR) and bovine serum albumin (BSA) was investigated by UV-Vis absorption, fluorescence and circular dichroism (CD) spectra at 296, 303 and 310 K, respectively. With fluorescence quenching method, the binding constants Ka were determined to be 1.5 x 10(4) L x mol(-1), 9.5 x 10(3) L x mol(-1), 4.9 x 10(3) L x mol(-1) and the number of binding site was 1 at three temperatures, respectively. The conformation of BSA was altered (CD data) with the reductions of alpha-helices from 33.5% for free BSA to 29.7%, and with increases of beta-sheet from 13.6% for free BSA to 18.4% in the presence of VCR. The thermodynamic parameters, enthalpy change (deltaH) and entropy change (deltaS), were calculated to be -62.07 kJ x mol(-1) and -129.38 J x (mol x K)(-1) respectively, according to van't Hoff equation, which indicated that hydrogen bonds and van der walls interactions played major roles in the binding process.

Development of an indirect competitive ELISA for the detection of furazolidone marker residue in animal edible tissues.

Due to its carcinogenicity and mutagenicity, furazolidone has been prohibited completely from being used in food animal production in the world since 1995. To monitor the illegal abuse of furazolidone, a polyclonal antibody-based indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed for the determination of tissue-bound furazolidone metabolite 3-amino-2-oxazolidone (AOZ). The highly specific antibody was targeted for PAOZ, the benzaldehyde derivative of AOZ. The 50% inhibition values (IC 50) of 0.91 microg/L for AOZ was achieved with the most sensitive antibody Ab-B1 by altering ELISA conditions. In the ELISA, sample extraction and cleanup were performed by an is MAX cartridge following combined hydrolysis of the tissue-bound AOZ and derivatization of the homogenized tissues with benzaldehyde. The limits of detection (LOD) calculated from the analysis of 20 known negative tissue samples (swine liver, swine muscle, chicken liver, chicken muscle,and fish muscle) were 0.3-0.4 microg/kg (mean+3 SD). Recoveries of AOZ fortified at the levels of 0.4, 1, and 5 microg/kg ranged from 55.8 to 96.6% in the tissues. The coefficients of variation were less than 20% over the range of AOZ concentrations studied. The linear detection range was between 0.1 and 25.6 microg/L. Validation of the ELISA method with swine muscle and liver from furazolidone-treated pigs was carried out using HPLC, resulting in a similar correlation in swine muscle (r=0.99) and in swine liver (r=0.98). The results suggest that this ELISA is a specific, accurate, and sensitive method of detecting AOZ residues in animal edible tissues.

[Spectroscopy study on the interaction of colchicine and human serum albumin].

The binding reaction of colchicine with human serum albumin (HSA) was studied by UV-Vis absorption, fluorescence and circular dichroism spectrometry. The results indicated that colchicine led to the increase in UV absorption and the quenching of intrinsic fluorescence of HSA. As the temperature increased, the quenching constant Ksv decreased. The binding constants and the numbers of the binding sites of the interaction between colchicine and HSA at different temperatures were obtained. The thermodynamic parameters, enthalpy change (DeltaH) and entropy change (DeltaS), were calculated to be -11.66 kJ x mol(-1) and 51.507 J(mol x K)(-1) respectively according to Van't Hoff equation, which suggested that the main binding force between colchicine and HSA was static interaction. The protein conformation was altered (CD date) with decreasing of alpha-helices in the presence of colchicine. The results showed that the quenching mechanism of the combination of colchicine with human serum albumin was a static quenching procedure.

[Modulation effects of recombinant human growth hormone on postburn hypermetabolism in burn patients].

OBJECTIVE: To explore the effects of recombinant human growth hormone (rhGH) on postuburn hypermetabolism in burn patients and its mechanism. METHODS: Thirty-two patients inflicted with burn of 50% to 90% TBSA admitted to our department during past 5 years (1998-2002) were enrolled in the study and randomly divided into A (with 0.25 U.kg(-1).d(-1) of rhGH treatment on 7-10 PBD, n=16) and B (with 0.25 U.kg(-1).d(-1) of normal saline as control, n = 16) groups. The changes in the rest energy expenditure (REE), non-protein respiratory quotient (NPRQ), glucose metabolism, nitrogen balance as well as plasma levels of endocrines and inflammatory mediators were determined before and after the administration of rhGH. RESULTS: rhGH was given to patients in group A during 7 - 10 PBD. The NPRQ in group A began to increase at the 7th PBD, raised to 0.80 +/- 0.09 in the 21st PBD. The plasma levels of PGE2, TXB2, TNF-alpha and IL-6 significantly decreased and insulin, rhGH and IGF-1 obviously increased when compared with those in group B. The accumulated nitrogen loss in group A was also much lower than that in group B. The plasma levels of adrenaline, cortisol, glucagon in group A were significantly higher than those in group B (P < 0.05). CONCLUSION: The postburn administration of rhGH timely could regulate postburn hypermetabolism in severely burned patients by increasing the plasma levels of GH, IGF-1 and insulin, which was beneficial to the improvement of nutrition state and to the promotion of protein synthesis and wound healing.