Long noncoding RNA PVT1 predicts poor prognosis and promotes the progression of colorectal cancer through the miR-24-3p/NRP1 axis in zebrafish xenografts.

Long noncoding RNAs (lncRNAs) play important roles in the progression of human cancer. It is reported that lncRNA plasmacytoma variant translocation 1 (PVT1) is involved in colorectal cancer (CRC), however, the underlying mechanism remains to be explored deeply, especially by in vivo models. In the present study, bioinformatics analysis showed that the expression level of PVT1 was upregulated in CRC tissues and highly associated with poor prognosis of CRC patients. In cultured CRC cells, knockdown of PVT1 inhibited cell proliferation and migration of CRC cells, while overexpression of PVT1 promoted the progression of CRC cells. In zebrafish xenografts, the silencing of PVT1 also suppressed the growth and metastasis of CRC cells. For mechanism studies, the binding relationships among PVT1, miR-24-3p, and Neuropilin 1 (NRP1) were predicted by starBase firstly. The luciferase reporter assays verified that PVT1 and NRP1 could bind with miR-24-3p directly. Further studies showed miR-24-3p negatively regulated the progression of CRC cells, the inhibition of miR-24-3p counteracted the repression effects of CRC progression when knocking down PVT1. In addition, the expression of NRP1 was regulated by PVT1, and NRP1 overexpression could partially rescue the inhibition effects of CRC progression when knocking down PVT1 in vitro and in vivo. Our study reveals that PVT1 promotes the proliferation and metastasis of CRC via regulating the miR-24-3p/NRP1 axis, which provides a prognosis biomarker and a potential therapeutic target for CRC patients.

Circ-LDLRAD3 Enhances Cell Growth, Migration, and Invasion and Inhibits Apoptosis by Regulating MiR-224-5p/NRP2 Axis in Gastric Cancer.

BACKGROUND: Emerging as a newly discovered type of noncoding RNAs, circular RNAs have been manifested as a crucial regulator in tumorigenesis of human malignancies, including gastric cancer (GC). Although circ-LDLRAD3 has been revealed as an oncogene in pancreatic cancer, the underlying role of circ-LDLRAD3 in GC remains poorly understood. AIMS: Exploring the underlying function of circ-LDLRAD3 on GC progression. METHODS: Circ-LDLRAD3 expression was detected through RT-qPCR. EdU, colony formation, TUNEL, and transwell assays were performed to analyze the function of circ-LDLRAD3 on GC progression. Luciferase reporter and RIP assays were applied to testify the interaction between circ-LDLRAD, miR-224-5p, and NRP2 in GC. RESULTS: We detected preliminarily the expression of circ-LDLRAD3 and observed a markedly high expression of circ-LDLRAD3 in GC cells. Besides, circ-LDLRAD3 was featured with loop structure. Biological function assays testified that silenced circ-LDLRAD3 inhibited cell proliferation, migration, and invasion capacity but facilitated apoptosis of GC cells. Molecular mechanism assays uncovered that circ-LDLRAD3 combined with miR-224-5p in GC. Moreover, rescue assays delineated that inhibited expression of miR-224-5p could restore the inhibitive influence of circ-LDLRAD3 knockdown on the progression of GC. Moreover, neuropilin 2 (NRP2) was a downstream target of miR-224-5p. Additionally, circ-LDLRAD3 regulated NRP2 expression by sponging miR-224-5p in GC. Furthermore, circ-LDLRAD3 depletion-mediated effect on GC progression could be reversed by overexpressing NRP2. CONCLUSIONS: Circ-LDLRAD3 facilitates GC progression by regulating miR-224-5p/NRP2 axis, providing new insights for the researches of GC treatment.

Normal reference intervals of prognostic nutritional index in healthy adults: A large multi-center observational study from Western China.

BACKGROUND: It has been widely reported that the prognostic nutritional index (PNI) played a pivotal role in nutritional assessment of surgical patients and tumor prognosis. In order to improve the accuracy of evaluation in Western China, we established reference intervals (RIs) of PNI in healthy controls. METHODS: A retrospective cohort study on healthy ethnic Han adults (18-79 years) was conducted to explore the influences of age, gender, study centers, and instruments on PNI and to establish RIs. The data came from a healthy routine examination center database and laboratory information system (LIS) of four centers in Western China, and there were 200 persons selected randomly for verification of RIs. RESULTS: Five thousand eight hundred and thirty-nine healthy candidates were enrolled. PNI showed a marked gender dependence, and males had significantly higher PNI than females across all ages (p < 0.01). We found that PNI is significantly different between age groups (p < 0.01), the value of PNI tended to decrease with age increasing. There is also an obvious influence of centers and instruments on PNI (p < 0.01). CONCLUSIONS: We established reference intervals of PNI in healthy Han Chinese population in Western China and validated successfully. Further established RIs will lead to better standardizations of PNI for clinical applications.

Normal Reference Intervals of Neutrophil-To-Lymphocyte Ratio, Platelet-To-Lymphocyte Ratio, Lymphocyte-To-Monocyte Ratio, and Systemic Immune Inflammation Index in Healthy Adults: a Large Multi-Center Study from Western China.

BACKGROUND: Numerous studies have shown that the hematological components of the systemic inflammatory response, including the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the lymphocyte-to-monocyte ratio (LMR), and the systemic immune inflammation index (SII) are efficient prognostic indicators in patients with cancers. Most of the studies did not investigate the reference intervals (RIs) of these parameters in healthy controls. METHODS: A retrospective cohort study was performed on healthy ethnic Han population aged between 18 and 79 years of age by retrieving the data from a healthy routine examination center database and laboratory infor-mation system of four participating centers in western China. By following the Clinical and Laboratory Standards Institute (CLSI), RIs of each parameter was established and validated. RESULTS: The analysis included 5,969 healthy subjects. We found that the individual's gender can significantly influence PLR, LMR, and SII (all p < 0.05), but not NLR (p > 0.05). Surprisingly, we also found that with an increase in age, the PLR, LMR, and SII tend to decrease, while NLR remained stable. PLR, LMR, and SII values were significantly higher in the young adults (18 - 64 years) than in old adults (65 - 79 years) (p < 0.001). The RIs of NLR, PLR (adults), PLR (old adults), LMR and SII were 0.88 - 4.0, 49 - 198, 42 - 187, 2.63 - 9.9, 142 x 109/L - 804 x 109/L, respectively. CONCLUSIONS: Our study addresses possible variations and establishes consensus for the NLR, PLR, LMR, and SII RIs for healthy Han Chinese adults in western China. Further, established RIs can standardize clinical applications and promote the use of these indicators into the routine complete blood count report.

Adenovirus-mediated overexpression FADD induces a significant antitumor effect on human colorectal cancer cells both in vitro and in vivo.

The Wnt/ß-catenin signaling pathway plays important roles in cancers such as colorectal cancer. Colon cancer cells secrete and express high levels of ß-catenin, which may stimulate autocrine signaling and further enhance activities of the canonical Wnt signaling pathway. Free ß-catenin in the cytoplasm and nucleus leads to its association with T cell factor (TCF)/lymphocyte enhancing factor (Lef) transcription factors, and subsequent transcriptional activation of downstream target genes. FADD plays a key role in cellular apoptosis in many different types of cancer. Therefore, a recombinant adenovirus is constructed, in which an apoptosis gene FADD is placed under control of a promoter containing Tcf-responsive elements. It is observed that FADD overexpression can suppress cell growth and enhance apoptosis of SW480 cells in vitro. In addition, Ad-FADD can also suppress the growth of subcutaneous xenografts in the nude mice. Together, these results suggest that Ad-FADD has anti-proliferative and pro-apoptotic effects in colon cancer cells, which provides a novel strategy for treatment of colorectal cancer.

[Effects of MSP on Cell Cycle and EMT of Non-Small Cell Lung Cancer PC14].

OBJECTIVE: To study the effect of macrophage stimulating protein (MSP) on the cell cycle of non-small cell lung cancer PC14 cells without expression of recepteur d'originenanta (RON) and MSP,and analyse its effect on PC14's epithelial mesenchymal transition (EMT) capacity. METHODS: Vitro culture PC14 (blank control),PC14-Mst1-pEGFP-N1 (stablely expressed MSP) and PC14-pEGFP-N1. Cell cycles were detected by flow cytometry and the gaps between cells during growth were measured by transmission electron microscope (TEM); RT-PCR and Western blot were used to figure out the shifts of EMT related gene expression in PC14-Mst1-pEGFP-N1 cells. RESULTS: Compared with the PC14 group and PC14-pEGFP-N1 group,PC14-Mst1-pEGFP-N1 population of G1/G0 phase were significantly increased while S and G2/M phase were significantly reduced;The gaps between PC14-Mst1-pEGFP-N1 cells decreased; RT-PCR and Western blot showed that mRNA and protein levels of E-cadherin of PC14-Mst1-pEGFP-N1 were significantly higher than that of PC14,but mRNA and protein levels of Vimentin were significantly lower. CONCLUSION: MSP may affect the cell cycle of PC14 and inhibit its EMT procedure by regulating the expression of related proteins including E-cadherin and Vimentin when RON was not expressed.

[Effects of Msp on the Proliferation, Migration and Invasion of Human Non-small Cell Lung Cancer Cells].

OBJECTIVES: To determine the effects of macrophage stimulating protein (Msp) on the proliferation, migration and invasion of human non-small cell lung cancer cells PC14. METHODS: The eukaryotic expression vector for st1was constructed and transfected into Msp(-)and RON(-)human non-small cell lung cancer cells PC14. The expression of st1mRNA in PC14 cells was observed by RT-PCR. The expression levels of Msp protein in PC14, PC14-st1-pEGFP-N1 and PC14-pEGFP-N1 groups as well as the expression of RON in PC14 and SKBR-3 cells were detected by Western blot. RAW264.7 (mouse monocyte macrophage) and SKBR-3 cells were cultured in the supernatant of cells(PC14, PC14-st1-pEGFP-N1and PC14-pEGFP-N1 groups)and tested with Transwell microporous membrane, through which the biologic activity of Msp was evaluated by calculating the cell number migrated. The proliferation of PC14 was measured by MTT assay. The capabilities of PC14 to migrate and invade were measured by Transwell chamber and Matrigel invasion tests, respectively. RESULTS: The expressions of mRNA and protein of Mst1 in PC14 were stable after transfection with Mst1. Msp (PC14-st1 -pEGFP-N1 group) promoted the migration of RON (+) cells (SKBR-3 and RAW264.7). Compared with PC14 and PC14-pEGFP-N1 groups, the proliferation, migration and invasion of PC14 cells in PC14-st1 -pEGFP-N1 group were inhibited significantly. CONCLUSIONS: Msp can promote the migration of RON (+) cancer cells in paracrine secretion manner and inhibit the proliferation, migration and invasion of human non-small cell lung cancer cells PC14 in an unknown way.

[The Correlation Between MicroRNAs in Serum and the Extent of Liver Injury].

OBJECTIVES: To investigate the correlation between the absolute quantification of the microRNAs (miR-122, miR-451, miR-92a, miR-192) in serum during acute liver injury and the extent of liver injury on rat models of CCl4 induced acute liver injury and mice models of acetaminophen (APAP) induced acute liver injury. Furthermore, to investigate the correlation between the absolute quantification of microRNAs in serum and the drug induced liver injury pathological scoring system (DILI-PSS). METHODS: The acute liver injury model in rat by CCl4 (1.5 mL/kg), and the acute liver injury model in mice by APAP (160 mg/kg) were established. The serum at different time points on both models were collected respectively. The absolute quantification of microRNAs in serum were detected by using MiRbayTM SV miRNA Assay kit. Meanwhile, the pathological sections of liver tissue of the mice at each time point were collected to analyze the correlation between microRNAs and the degree of liver injury. RESULTS: In CCl4-induced rat acute liver injury model and APAP induced mouse acute liver injury, miR-122 and miR-192 appeared to be rising significantly, which remained the highest level at 24 h after treatment, and declined to the normal level after 72 h. In CCl4-induced rat acute liver injury model, the change of miR-92a was fluctuated and had no apparent rules, miR-451 declined gradually, but not obviously. In mice acute liver injury model induced by APAP, miR-92a and miR-451 in the progress of liver injury declined gradually, reached the lowest point at 48 h, and then recovered. The result of correlation analysis indicated that miR-122 and miR-192 presented a good positive correlation with the DILI-PSS ( r=0.741 3, P<0.05; r=0.788 3, P<0.01). CONCLUSIONS: The absolute quantification of miR-122 and miR-192 in serum has the highest level in 24 h, then decrease in 72 h, in both drug-induced and chemical liver injury. In addition, both the two microRNAs have good correlation with DILI-PSS in APAP-induced liver injury models.

Circ_0041732 regulates tumor properties of triple-negative breast cancer cells by the miR-149-5p/FGF5 pathway.

BACKGROUND: Triple-negative breast cancer (TNBC) is a subtype of breast cancers with a high recurrence and mortality. The important factors promoting the TNBC process have not been fully identified. In this research, the role of a TNBC-related circular RNA (circRNA), circ_0041732, was revealed in TNBC cell tumor properties. METHODS: The expression levels of circ_0041732, microRNA-149-5p (miR-149-5p) and fibroblast growth factor 5 (FGF5) were detected by quantitative real-time polymerase chain reaction. The protein expression was determined by Western blot analysis or immunohistochemistry assay. Cell proliferation was detected by cell counting kit-8 and cell colony formation assays. Cell apoptosis was analyzed by flow cytometry and caspase-3 activity assays. Cell migration and invasion were evaluated by wound-healing and transwell invasion assays. Cell angiogenic capacity was investigated by a tube formation assay. The targeting relationship between miR-149-5p and circ_0041732 or FGF5 was identified by dual-luciferase reporter and RNA immunoprecipitation assays. The impacts of circ_0041732 knockdown on tumor formation were determined by an in vivo assay. RESULTS: Circ_0041732 and FGF5 expression were significantly upregulated, whereas miR-149-5p was downregulated in TNBC tissues and cells compared with normal breast tissues and cells, respectively. Circ_0041732 silencing inhibited TNBC cell proliferation, migration, invasion, and tube formation, but induced apoptosis. Additionally, circ_0041732 regulated TNBC cell tumor properties by binding to miR-149-5p. MiR-149-5p also modulated TNBC cell tumor properties by targeting FGF5. Furthermore, circ_0041732 knockdown hindered tumor formation in vivo. CONCLUSION: Circ_0041732 silencing suppressed TNBC cell tumor properties by decreasing FGF5 expression through miR-149-5p. This finding demonstrated that circ_0041732 had the potential as a therapeutic target for TNBC.

[Monitoring urine metabolic profiles of rat inflammation model with capillary electrophoresis].

OBJECTIVE: To determine the comprehensive metabolic profiling of inflammation with capillary zone electrophoresis (CZE) in rat urine. METHODS: CZE-based metabolomics method was used to acquire urine metabolom data, with Computer Aided Similarity Evaluation System aligning peaks and analyzing urine profiling. Principle component analysis (PCA) was performed to compare and classify the phenotypes of the urine CZE spectra. RESULTS: The PCA revealed different phenotypes of metabolites between rats with and without inflammation, which were independent from gender, individual diversity, day-night diversity and diurnal variation. CONCLUSION: CZE-based metabolomics method could be used as a potential tool for urinary profiling for disease diagnosis and drug studies.

[Metabonomic study of the urine of rat acute gouty arthritis model].

UNLABELLED: [ OBJECTIVE: To analysis the metabonome characteristics of the urine of MSU crystal-induced acute gouty arthritis rats by the method of metabolomics. METHODS: Based on the method of metabolomics, which applies LC/MS as data acquisition platform, incorporating with the means of stoechiometry such as principal component analysis, we analyzed the metabonome difference between the urine of acute gouty arthritis rats and that of normal rats. RESULTS: Compare with control group, the metabolism status of acute gouty arthritis model group deviated. After that, with the time lapsed, it retrieved gradually to the incipient metabolism status. The variation of metabolism locus of rats measured by the methods of metabolomics properly reflects the genesis, development, and recuperation course of acute gouty arthritis. CONCLUSION: The whole metabolism status of rat model is able to be presented finely with the method of metabolomics. The metabolomics study could offer a satisfactory research approach to acute gouty arthritis.

[Adenovirus-mediated delivery of nm23-H1 gene inhibits growth of colorectal carcinoma cell line Lovo].

This experimental study sought to find out the inhibitory effects of Ad-GFP-nm23-H1 on proliferation and metastasis of human colorectal carcinoma cell line Lovo, and, further, to gain an insight into some theoretical and methodical basis for instituting nm23-H1 gene therapy of cancers. MTT assay and Transwell chamber were used to detect the rates of proliferation and invasion as well as the adhesion of Lovo cells in vitro. The results demonstrated that the proliferation inhibition rates of Lovo cells treated with Ad-GFP-nm23-H1 of 10(10) PFU/ml, 10(9) PFU/ml and 10(8) PFU/ml were 84.9% +/- 1.51%, 48.5% +/- 7.23% and 22.5% +/- 5.47%, that the adherence inhibition rates of Lovo cells treated with Ad-GFP-nm23-H1 of 10(10) PFU/ml, 10(9) PFU/ml and 10(8) PFU/ml were 70.3% +/- 2.40%, 60.1% +/- 5.68% and 18.5% +/- 3.61%, and that the invasiveness inhibition rates of Lovo cells treated with Ad-GFP-nm23-H1 of 10(10) PFU/ml, 10(9) PFU/ml and 10(8) PFU/ml were 83.2% +/- 5.71%, 52.2% +/- 6.94% and 28.1% +/- 8.21%. These data suggested that Ad-GFP-nm23-H1 exerted significant inhibitory effects on the proliferation and metastasis of human colorectal carcinoma cell line Lovo in a dose-dependent way.

[Pharmacokinetics of PEG recombinant human interleukin-6 in rats].

OBJECTIVE: To study the pharmacokinetics and tissue distribution of PEG-rhIL-6 in rats after a single dose administration. METHODS: Pharmacokinetics and distribution of PEG-rhIL-6 in rats were studied by 125I isotope tracing method. Pharmacokinetic analysis was performed using 3P97 computer software. RESULTS: PEG-rhIL-6 declined in one-compartment model with half-lives of 10.44-11.37 h for t1/2 Ka, 19.77-21.53 h for t1/2 Ke and 20.51-21.96 h for T(pcak), respectively. PEG-rhIL-6 was mainly distributed in blood and excreted via urine. CONCLUSION: The half-lives of PEG-rhIL-6 are prolonged after being modified by PEG.

Unsupervised feature selection via latent representation learning and manifold regularization.

With the rapid development of multimedia technology, massive unlabelled data with high dimensionality need to be processed. As a means of dimensionality reduction, unsupervised feature selection has been widely recognized as an important and challenging pre-step for many machine learning and data mining tasks. Traditional unsupervised feature selection algorithms usually assume that the data instances are identically distributed and there is no dependency between them. However, the data instances are not only associated with high dimensional features but also inherently interconnected with each other. Furthermore, the inevitable noises mixed in data could degenerate the performances of previous methods which perform feature selection in original data space. Without label information, the connection information between data instances can be exploited and could help select relevant features. In this work, we propose a robust unsupervised feature selection method which embeds the latent representation learning into feature selection. Instead of measuring the feature importances in original data space, the feature selection is carried out in the learned latent representation space which is more robust to noises. The latent representation is modelled by non-negative matrix factorization of the affinity matrix which explicitly reflects the relationships of data instances. Meanwhile, the local manifold structure of original data space is preserved by a graph based manifold regularization term in the transformed feature space. An efficient alternating algorithm is developed to optimize the proposed model. Experimental results on eight benchmark datasets demonstrate the effectiveness of the proposed method.

Molecular cloning and sequence analysis of interferon-gamma and interleukin-6 from Tibetan macaque (Macaca thibetana).

The cloning and sequence analysis of Tibetan macaque IFN-(gamma) and the IL-6 cDNAs are described. The Tibetan macaque IFN-gamma and IL-6 cDNAs were found to be 498 and 639 bp in length, with open reading frames encoding 165 and 212 amino acids, respectively. Homology analyses indicated that the identity levels of nucleotide and deduced amino acid sequences of IFN-gamma among primates ranged from 93.4 to 99.2%, and 87.3 to 99.4%, respectively, and that of IL-6 ranged from 92.6 to 99.8%, and 85.4 to 99.5%, respectively. Phylogenetic analysis based on amino acid sequences showed that the Tibetan macaque is most closely related to Old World monkeys, as compared to Hominoidea and New World monkeys. These findings provide insights into the evolution of primate IFN-gamma and IL-6 and additional valuable information regarding amino acid residues essential for their biological activity.

[Impedance effects of interleukin-6 on cyclophosphamide-induced hematopoietic damnification in dogs].

The aim of this study is to evaluate the effect of Interleukin-6 on cyclophosphamide-induced hematopoietic damnification. The doses of Interleukin-6 in 3 different regimens were hypodermally injected into dogs for 7 days respectively to establish the cyclophosphamide-induced hematopoietic damnification model. The effect of Interleukin-6 on the production of platelets and the amount of other cells in the dogs' bone marrow were determined on the 21st day. The results showed that Interleukin-6 significantly alleviated the reduction of platelet count and recovered the platelets level faster. The impedance effects of Interleukin-6 directed against hematopoietic damnification of bone marrow and spleen were shown by pathological examination. These suggest that the Interleukin-6 can significantly impede cyclophosphamide-induced hematopoietic damnification.

Elevated cyclin A associated kinase activity promotes sensitivity of metastatic human cancer cells to DNA antimetabolite drug.

Drug resistance is a major obstacle in successful systemic therapy of metastatic cancer. We analyzed the involvement of cell cycle regulatory proteins in eliciting response to N (phosphonoacetyl)-L-aspartate (PALA), an inhibitor of de novo pyrimidine synthesis, in two metastatic variants of human cancer cell line MDA-MB-435 isolated from lung (L-2) and brain (Br-1) in nude mouse, respectively. L-2 and Br-l cells markedly differed in their sensitivity to PALA. While both cell types displayed an initial S phase delay/arrest, Br-l cells proliferated but most L-2 cells underwent apoptosis. There was distinct elevation in cyclin A, and phosphorylated Rb proteins concomitant with decreased expression of bcl-2 protein in the PALA treated L-2 cells undergoing apoptosis. Markedly elevated cyclin A associated and cdk2 kinase activities together with increased E2F1-DNA binding were detected in these L-2 cells. Induced ectopic cyclin A expression sensitized Br-l cells to PALA by activating an apoptotic pathway. Our findings demonstrate that elevated expression of cyclin A and associated kinase can activate an apoptotic pathway in cells exposed to DNA antimetabolites. Abrogation of this pathway can lead to resistance against these drugs in metastatic variants of human carcinoma cells.

[The application of computer assisted sperm analysis on in vitro fertilization].

OBJECTIVE: To set up the prognostic parameters for clinical use of IVF-ET technique from the male side, the influence of the quantitative parameters about sperm motility on human in vitro fertilization rate was evaluated in this study. METHODS: The sperm samples were classfied into three groups in accordance to the eggs' in vitro fertilization rate of > or =50%, <50% and zero. Besides,based on the achievement of pregnancy after embryo transfer, the samples were divided into two groups: pregnancy achieved and pregnancy not achieved. Then we adopted the system of computer assisted sperm analysis (CASA) in assessing some parameters about sperm movement. The correlation between them and IVF rate or pregnancy was analyzed with t-test. RESULTS: This study embraced 69 IVF cycles, among which 64 cycles were completed with 20 cases of pregnancy, including biochemical and clinical pregnancies. The data on sperm movement parameters showed significant difference in Progressive motility, VAP, VSL, VCL and Percent normal sperm morphology between the > or =50% group and the <50% and zero groups (P < 0.01). Significant difference in the above parameters was also observed between the pregnancy positive and negative groups (P < 0.01). Besides, there were significant differences in Sperm movement parameters and Percent normal morphology between pre- and post-washed groups (P < 0.05). CONCLUSION: This study has demonstrated that the success rate of "test tube baby" is tightly related to some sperm movement parameters, thus suggesting VAP, VSL and VCL can serve as prognostic parameters for clinical application of IVF.

[Effects of leptin on development of mouse preimplantation embryos in vitro].

OBJECTIVE: To investigate the effects of leptin on development of mouse preimplantation embryos in vitro. METHODS: (1) Groups of 2-cell stage embryos randomly selected were placed in drops of CZB medium with or without recombinant leptin (10, 50, 100 and 500 ng/ml) and were cultured to the hatched blastocyst stage, and then embryo-transfer was carried out and the implantation rate was observed and determined. (2) Groups of 2-cell stage embryos randomly selected were placed in drops of leptin free CZB medium and cultured to morula stage. Then we changed the medium, randomized the embryos into CZB medium with or without recombinant leptin (10, 50, 100 and 500 ng/ml), and cultured them to the hatched blastocyst stage. RESULTS: Addition of leptin to embryo culture media promoted the development from 2-cell stage embryo to morula, blastocyst and hatched blastocyst and improved the implantation rate. Leptin at 0, 10, 50 ng/ml concentrations caused a dose-dependent promotion, nevertheless Leptin at even higher concentrations (100 and 500 ng/ml) only brought on the same promotion as what the Leptin at concentration of 50 ng/ml did (P>0.05). Addition of leptin to embryo culture media seemed to have no effects on the in vitro development from morula to blastocyst and hatched blastocyst. CONCLUSION: Leptin plays an important role in the development of preimplantation embryo. It can promote embryo development and embryo implantation.

A multiple-dose pharmacokinetics of polyethylene glycol recombinant human interleukin-6 (PEG-rhIL-6) in rats.

Radiation therapy has been widely applied in cancer treatment. However, it often causes thrombocytopenia (deficiency of white blood cells) as an adverse effect. Recombinant human interleukin-6 (rhIL-6) has been found to be a very effective way against this thrombocytopenia, but IL-6 has low stability in blood, which reduces its efficacy. To increases the stability and half-life of rhIL-6, it was modified by polyethylene glycol (PEG). The pharmacokinetics and the tissue distribution of PEG-rhIL-6 labeled with (125)I were examined after subcutaneous injection in rats. The pharmacokinetic pattern of PEG-rhIL-6 was defined with linear-kinetics, and we fitted a one-compartment model with half-lives of 10.44-11.37 h (absorption, t(1/2Ka)) and 19.77-21.53 h (elimination, t(1/2Ke)), and peak concentrations at 20.51-21.96 h (t(peak)) in rats. Half-lives and t(peak) of PEG-rhIL-6 were longer than those of rhIL-6 previously reported. In the present study, for deposition of PEG-rhIL-6 in rats, the tissue distribution examination showed that blood was the major organ involved, rather than liver. However, as to the elimination of PEG-rhIL-6, the major organ was the kidney. The excretion fraction of the injection dose recovered from urine was 23.32% at 192 h after subcutaneous administration. Less than 6% of PEG-rhIL-6 was eliminated via the feces at 192 h. These results indicate that PEG-rhIL-6 is a good candidate drug formulation for patients with cancer.