Forensic and phylogenetic analyses of populations in the Tibetan-Yi corridor using 41 Y-STRs.

Y-chromosome haplotypes of 527 non-related males (176 Han, 186 Tibetan, and 165 Yi) in the Tibetan-Yi corridor were analyzed using SureID® PathFinder Plus. In the populations of Han, Tibetans, and Yi, the haplotype diversity was 0.9989, 0.9981, and 0.9993, respectively, and the discrimination capacity was 0.9148, 0.8925, and 0.9576, respectively. Phylogenetic relationships among 12 studied ethnic groups and 7 other ethnic groups in the Tibetan-Yi corridor were investigated. Both multi-dimensional scaling analysis and phylogenetic reconstructions indicated that Tibetans appeared separated from the Han and Yi ethnic groups in the Tibetan-Yi corridor. Their genetic homogeneity or heterogeneity has not entirely been affected by their geographical distance and linguistic origin.

[Determination of morroniside concentration in rat plasma by high performance liquid chromatography-tandem mass spectrometry].

Morroniside, an iridoid glycoside extracted from Cornus officinalis, has multiple pharmacological effects such as neuroprotection. This study took the lead in establishing a method for determining morroniside concentration in rat plasma by high performance liquid chromatography-tandem mass spectrometry. Plasma samples were processed with protein precipitation method, with hyperoside as the internal standard. An Inertsil C8-3 column (2. 1 mm x 50 mm, 5 microm) was adopted, with a mobile phase composed of water (containing 1 mmol L-1 Sodium formate)-acetonitrile (gradient elution) at a flow rate of 0.4 mL . min -1. Electrospray ionization (ESI) was adopted in the positive ion mode for multi-reaction monitoring (MRM). Morroniside showed a good linear relationship ranging between 2-5 000 microg L-1 (r = 0. 995 7), with the minimum limit of quantification of 2 microg L-1. Its precise, accuracy, recovery and matrix effect were all in line with the biological sample measurement requirements. Therefore, the method described above was proved to be suitable for the determination of morroniside concentration in rat plasma. To use the method in the pharmacokinetic study on morroniside in rats, oral administration dose shall be set at 20 mg . kg - to map the plasma concentration-time curve. Main pharmacokinetic parameters were calculated by DAS 2. 0. Specifically, AUC0-inifinity was (587.6 +/- 290. 7) microg min L-1, Cmax was (334.2+/-148.0) microg L-1, Tmax was (0.6 +/-0.3) h, t1/2 was (0.7+/-0.3) h.

Structural and functional biomimetics of [Fe]-hydrogenase featuring a mono-, di- or tetrasubstituted pyridine ligand with a fac-C, N, and S ligation.

The combined structural and functional modeling study of [Fe]-H2ase has remained a great challenge, to date. Now, we report a series of new structural and functional [Fe]-H2ase models (1-6) that contain a mono-, di- or tetrasubstituted pyridine ligand with a biomimetic fac-C, N, and S ligation. While models 1-3, 5 and 6 are conveniently prepared by a novel flexible pyridine ligand (FPL)-based method, model 4 is prepared simply by an intramolecular CO replacement reaction of model 3. More interestingly, the structural study by spectroscopy and X-ray crystallography proves that these new models include a biomimetic fac-acyl (or methylene) C, pyridyl N, and thioether S ligation to an Fe(II) center and the C-Fe(II) σ bond is trans to an iodo ligand. In addition, the chemical reactivity study proves that they all have the enzyme-like H2 activation and hydride transfer functions in the presence of imidazolium Im+, AgBF4 and Et3N. Particularly interesting is that a possible pathway for such H2 activation and hydride transfer reactions catalyzed by a representative model 4 is proposed and the existence of the highly unstable 5-coordinate intermediate M4 and Fe-H species M5 is supported by the isolation and characterization of their MeCN-coordinated derivative 7 and chloro-substituted derivative 8, respectively.

Biomimetic models of [Fe]-hydrogenase featuring a 2-acylphenylthiomethyl-6-R-pyridine (R = H or OMe) ligand.

Despite a variety of [Fe]-H2ase models prepared so far, the structural and functional modeling study of the enzyme has remained a great challenge. Now, we report a new type of flexible pyridine ligand (FPL)-based synthetic method by which two novel [Fe]-H2ase models have been prepared. Notably, the two models contain not only a biomimetic fac-acyl C, pyridyl N, thioether S coordination mode but also possess the enzyme-like H2/D2 activation functions.

Pharmacokinetic properties of albiflorin and paeoniflorin after oral administration of pure compound, Radix Paeoniae alba extract and danggui-shaoyao-san extract to rats.

This study compared the pharmacokinetics of albiflorin (ALB) and paeoniflorin (PAE), respectively, after oral administration of ALB, PAE, Radix Paeoniae alba (RPA) extract, and Danggui-Shaoyao-San (DSS) extract to rats on separate occasions. Analytes were detected simultaneously with liquid chromatography-tandem mass spectrometry. Noncompartmental pharmacokinetic parameters were calculated. After oral administration of RPA and DSS extract to rats, ALB reached maximum concentrations of 4637 ± 2774 ng/ml (0.40 ± 0.14 h) and 226 ± 122 ng/ml (0.35 ± 0.14 h) and PAE reached maximum concentrations of 2132 ± 560 ng/ml (0.40 ± 0.14 h) and 143 ± 65 ng/ml (0.45 ± 0.11 h), respectively. Compared to the AUC(0 - t) value (1122 ± 351 and 722 ± 158 ng h/ml for ALB and PAE, respectively) after administration of monomers, larger AUC(0 - t) value of ALB (4755 ± 2560 ng h/ml) and PAE (2259 ± 910 ng h/ml) after administration of RPA extract and smaller AUC(0 - t) value of ALB (411 ± 118 ng h/ml) and PAE (242 ± 126 ng h/ml) after administration of DSS extract were obtained. The C(max), AUC, and K(el) of ALB and PAE were remarkably increased (P < 0.05, 0.01 or 0.005) during oral administration of RPA extract in comparison to that of DSS extract.

[Research progress of enhancing quantitative sensitivity by using LC-MS(n) with derivatization method in bio-matrices].

Liquid chromatography/mass spectrometry (LC-MS(n)) has been essential to a large number of quantitative analytical applications in drug research, and especially in the drug PK/PD research, due to its high sensitivity and high specificity. But following the appearance of drugs with high activity and low dosage and the especial structural compounds, a number of limitations of LC-MS(n) have been noted. Derivatization changes the structure of drugs and therefore changes their physical and chemical properties, resulting in high ionization efficiency, low matrix effect and low disturbance by inorganic salts and endogenous compounds in LC-MS(n). In this article, recent progress in the research of the chemical derivatization strategy with LC-MS(n) is reviewed on breakthrough of some LC-MS(n) limitations, in particular focusing on the applications involving some drugs in bio-matrices.

Weighted Gene Coexpression Network Analysis Reveals Essential Genes and Pathways in Bipolar Disorder.

Bipolar disorder (BD) is a major and highly heritable mental illness with severe psychosocial impairment, but its etiology and pathogenesis remains unclear. This study aimed to identify the essential pathways and genes involved in BD using weighted gene coexpression network analysis (WGCNA), a bioinformatic method studying the relationships between genes and phenotypes. Using two available BD gene expression datasets (GSE5388, GSE5389), we constructed a gene coexpression network and identified modules related to BD. The analyses of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways were performed to explore functional enrichment of the candidate modules. A protein-protein interaction (PPI) network was further constructed to identify the potential hub genes. Ten coexpression modules were identified from the top 5,000 genes in 77 samples and three modules were significantly associated with BD, which were involved in several biological processes (e.g., the actin filament-based process) and pathways (e.g., MAPK signaling). Four genes (NOTCH1, POMC, NGF, and DRD2) were identified as candidate hub genes by PPI analysis and CytoHubba. Finally, we carried out validation analyses in a separate dataset, GSE12649, and verified NOTCH1 as a hub gene and the involvement of several biological processes such as actin filament-based process and axon development. Taken together, our findings revealed several candidate pathways and genes (NOTCH1) in the pathogenesis of BD and call for further investigation for their potential research values in BD diagnosis and treatment.

Metabolic stability of human parathyroid hormone peptide hPTH (1-34) in rat tissue homogenates: kinetics and products of proteolytic degradation.

The present study aim to investigate the metabolic stability and degradation of cleavage sites of human parathyroid hormone peptide, hPTH (1-34), in rat tissue homogenate, and to identify the types of proteases involved in hPTH (1-34) processing degradation. The stability of hPTH (1-34) in rat kidney, lung and liver homogenates was evaluated by LC-ESI-MS, and the structures of the major degradation products were identified by MALDI-TOF MS and LC-ESI-MS/MS. The ability of protease inhibitors to inhibit hPTH (1-34) degradation was used to identify the class of proteases involved in the metabolism of hPTH (1-34). hPTH (1-34) peptide was readily degraded in rat kidney, liver, and lung homogenates, with half-lives of 5.7, 32.2, and 18.9 min, respectively. The degradation of hPTH (1-34) in each tissue can be inhibited by inhibitors of serine and metalloproteases. The major degradation products of hPTH (1-34) are similar in each tissue and suggest that hPTH (1-15) and hPTH (16-34) appear as the major degradation products. The degradation patterns of hPTH (1-34) incubated in rat kidney, liver and lung homogenates are largely overlapping, and a majority of the fragments are generated via cleavages at sites of Leu15-Asn16 peptide bond.

Purification, structure characterization and antioxidant activity of polysaccharides from Saposhnikovia divaricata.

Polysaccharide from traditional Chinese herb, Saposhnikovia divaricata (Turcz.) Schischk. (SD) was extracted, fractionated and characterized in this work. Four fractions were prepared. Their molecular weight, monosaccharide compositions, linkage modes and structural properties were characterized with SEC-MALS-RI, HPAEC-PAD, GC-MS and NMR. SDP1 was assigned as a 1, 4-α-glucan with small amount of O-6 linked branches. SDP2 contained a big amount of the 1, 4-α-glucan and a small amount of arabinogalactan, while SDP3 possessed relatively lower amount of the 1, 4-α-glucan and a big amount of the arabinogalactan. SDP4 was defined as a pectic arabinogalactan. Four fractions showed antioxidant activities in both molecular and cellular levels and their activity was ranked as SDP4 ≈ SDP3>SDP2>SDP1. The 1, 4-α-glucan in SDP1 had the weakest, while SDP3 and SDP4 showed similar and the highest antioxidant activity. The arabinogalactan was the major component of both SDP3 and SDP4, which significantly contributed to the antioxidant activity of SDP.

Purification and characterization of a novel anti-coagulant from the leech Hirudinaria manillensis.

Protease inhibitors have been reported rarely from the leech Hirudinaria manillensis. In this study, we purified a novel protease inhibitor (bdellin-HM-2) with anticoagulant properties from H. manillensis. With a molecular weight of 1.4x104, bdellin-HM-2 was also characterized with three intra-molecular disulfide bridges at the N-terminus and multiple HHXDD and HXDD motifs at the C-terminus. cDNA cloning revealed that the putative nucleotide-encoding protein of bdellin-HM-2 contained 132 amino acids and was encoded by a 399 bp open reading frame (ORF). Sequence alignment showed that bdellin-HM-2 shared similarity with the "non-classical" Kazal-type serine protease inhibitors, but had no inhibitory effect on trypsin, elastase, chymotrypsin, kallikrein, factor XIIa (FXIIa), factor XIa (FXIa), factor Xa (FXa), thrombin, or plasmin. Bdellin-HM-2 showed anticoagulant effects by prolonging the activated partial thromboplastin time (aPTT), indicating a role in enabling H. manillensis to obtain a blood meal from its host. Our results suggest that bdellin-HM-2 may play a crucial role in blood-sucking in this leech species and may be a potential candidate for the development of clinical anti-thrombotic drugs.

Determination of 4-dimethylaminophenol concentrations in dog blood using LC-ESI/MS/MS combined with precolumn derivatization.

A sensitive and reproducible LC-ESI/MS/MS method, which was combined with the precolumn dansyl chloride derivatization to enhance the signal intensity of analytes, was developed to determine blood 4-dimethylaminophenol (DMAP) concentrations. The linearity of the method was observed within the concentration range of 2-2000 ng/mL. The precision, accuracy, stability, recovery and matrix effect of the method were also investigated and found to meet the requirements for pharmacokinetic studies of the drug. By using this method, pharmacokinetic studies were conducted in dogs after i.m. and i.v. administrations. The results showed that DMAP could not only be absorbed into blood quickly after i.m., but also can be eliminated rapidly. Both i.m. and i.v. routes are appropriate for DMAP to be used in field first-aid. It has been proved that this LC-MS/MS combined with precolumn derivatization method can be used as a routine analytical method to provide enhanced measurements for blood DMAP concentrations. It is also useful for DMAP pharmacokinetic evaluation.

Degradation of salmon calcitonin in rat kidney and liver homogenates.

Salmon calcitonin (sCT), a 32-amino-acid peptide, is the active component in many pharmaceuticals used for the management of bone diseases. In this study, the stability of sCT in rat kidney and liver homogenates were evaluated by LC-ESI-MS, and the structures of the major degradation products were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The results show that the half life of sCT was 13.18 min in rat kidney homogenate (2.5 mg/ml, protein concentration) and 43.07 min in rat liver homogenate (2.5 mg/ml, protein concentration). MALDI-TOF MS results indicated that sCT was initially cleaved at Leu9-Gly10 and Gly10-Lys11 bonds in rat kidney homogenate in vitro, at the same time, the major degradation fragment, Lys11-Pro32-NH2 Was metabolized at the C-terminal amide by deamidation, whereas in rat liver homogenate, the initial cleavage sites were at Val8-Leu9 and His17-Lys18. The results indicated that the metabolism of sCT proceeds by initial endoproteolytic cleavage and subsequent exoproteolytic digestion.

[Determination of decapeptide LXT-101 in plasma by HPLC-MS/MS and its pharmacokinetics in Beagle dogs].

This paper developed a sensitive and specific liquid chromatography-electrospray ionization mass spectrometry (HPLC-MS/MS) method for the determination of decapeptide LXT-101 in Beagle dog plasma. Plasma samples spiked with internal standard (IS) were treated with acetonitrile to precipitate the protein. Selected reaction monitoring (SRM) using the precursor --> product ion combinations of m/z 472.1-->587.9 and m/z 502.8-->633.8 were used to quantify LXT-101 and IS, respectively. The linear calibration curves were obtained in the concentration range of 0.5 - 500.0 ng x mL(-1). The limit of quantification (LOQ) was 0.5 ng x mL(-1). The inter-day and intra-day precision (RSD) across three validation run over the entire concentration range was below 10.9%, and the accuracy (RE) was within +/- 1.8%. The main pharmacokinetic parameters of LXT-101 after muscle injection of 20 microg x kg(-1) were as follows, AUC(0-t): (176.8 +/- 116.7) microg x h x L(-1), MRT(0-t): (2.52 +/- 0.53) h, T(1/2): (1.4 +/- 0.3) h; CL: (0.16 +/- 0.09) L x h(-1) x kg(-1), and Vd: (0.30 +/- 0.16) L x kg(-1), respectively. The method is proved to be specific, sensitive and suitable for the investigation of LXT-101 pharmacokinetics in Beagle dog.

In vitro and in vivo evaluation of hypothermia on pharmacokinetics and pharmacodynamics of nimodipine in rabbits.

Objective To investigate the effect of hypothermia on the pharmacokinetics and pharmacodynamics of nimodipine in rabbits using in vivo and in vitro methods. Methods Five healthy New Zealand rabbits received a single dose of nimodipine (0.5 mg/kg) intravenously under normothermic and hypothermic conditions. Doppler ultrasound was used to monitor cerebral blood flow, vascular resistance, and heart rate. In vitro evaluations of protein binding, hepatocyte uptake and intrinsic clearance of liver microsomes at different temperatures were also conducted. Results Plasma concentrations of nimodipine were significantly higher in hypothermia than in normothermia. Nimodipine improved cerebral blood flow under both conditions, but had a longer effective duration during the hypothermic period. Low temperature decreased the intrinsic clearance of liver microsomes, with no change in protein binding or hepatocyte uptake of nimodipine. Conclusion Nimodipine is eliminated at a slower rate during hypothermia than during normothermia, mainly due to the decreased activity of cytochrome P450 enzymes. This results in elevated system exposure with little enhancement in pharmacological effect.

A simplified model to predict P-glycoprotein interacting drugs from 3D molecular interaction field.

A new two components partial least squares discriminant analysis (PLS) model for the prediction of P-glycoprotein-associated ATPase activity of drugs by using VolSurf compute theoretical molecular descriptors derived from 3D molecular interaction field was reported in the present study. By using 27 diverse drugs from literature, two models were constructed (R(2)=0.9003, 0.8150; Q(2)=0.7165, 0.7630) in this paper, which were similar to models that utilized MolSurf parametrization (R(2)=0.7760, 0.7180; Q(2)=0.7420, 0.6950) by using 22 drugs reported in the same literature. The results investigated VolSurf software was superior to MolSurf in its simplicity. Properties associated with the volume, polarizability, and hydrogen bond could have important impact on the P-glycoprotein-associated ATPase activity.

Auto-Induction Effect of Chloroxoquinoline on the Cytochrome P450 Enzymes of Rats Associated with CYP 3A and 1A.

To investigate the auto-induction of cytochrome P450 (CYP450) by Chloroxoquinoline (CXL), a novel anticancer drug. Three experiments related to the induction of CYP450 were performed: a) In vitro use of the rat fresh hepatocytes model; b) In vivo 'cocktail' of CYP450 probe model; c) Pharmacokinetic (PK) study of the single and multiple doses. Some typical CYP enzyme probes and inducers were used in these experiments and were all determined by HPLC-MS/MS. The expression levels of CYP3A and CYP1A mRNA were analyzed by the real time polymerase chain reaction (RT-PCR) technique. The PK studies showed that the area under the curve (AUC0-t) and the peak concentration (Cmax) of the multiple doses were approximately 2.4-fold and 1.9-fold lower than those of the single dose, respectively (p < 0.05). Subsequent studies were conducted to study the possible induction of CXL on CYP 450. The in vivo 'cocktail' administration of CYP450 probe model indicated that 5 d pretreatment with CXL resulted in a mean 4.6 times increase in the metabolites/probe plasma ratios for CYP 3A and a 336% increase for CYP 1A than those of the negative control (p < 0.05). The induction effect of CXL on CYP450 was further evaluated on rat hepatocytes with four concentrations (1, 10, 50 and 100 µmol/L). Compared with the negative control, the mRNA levels of CYP 1A2 increased significantly in rat hepatocytes after treatment with 10, 50 and 100 µmol/L CXL (p < 0.05). While significant inductions of CYP 3A1 were observed in the entire treated groups. The results of the present study demonstrate enhanced and induced expression of CYP 3A and CYP 1A in response to CXL exposure in rats, suggesting that CXL is an auto-inducer of CYP 3A and CYP 1A.

Effects of pretreatment with 8018 on the toxicokinetics of soman in rabbits and distribution in mice.

The effects of 8018 [3-(2'-phenyl-2'-cyclopentyl-2'-hydroxyl-ethoxy)quinuclidine] on the elimination of soman in rabbits blood and distribution in mice brain and diaphragm were investigated using the chirasil capillary gas chromatographic analysis method. In all experiments, the concentration of P(+)soman was below the detection limit (<0.1 ng x mL(-1)). 8018 (1 mg x kg(-1), im, 10 min pre-treated) could significantly reduce the concentration of P(-)soman in rabbit blood from 53.6 +/- 13.3 to 26.2 +/- 9.70 ng x mL(-1) blood as compared to soman-treated control animal at 15 s following soman injection (43.2 microg x kg(-1), iv). Toxicokinetic parameters showed 8018 could increase clearance (CL((S))) from 20.8 +/- 1.54 to 38.2 +/- 15.3 mLx kg(-1) x s(-1) and reduce AUC of P(-)soman from 2.08 +/- 0.151 to 1.30 +/- 0.564 mg x s x L(-1). 8018 could reduce the concentration P(-)soman in diaphragm from 74.7, 70.5, 88.7 ng x g(-1) to 54.5 45.6, 50.0 ng x g(-1) at the time of 30, 90, 120 s after intoxication of soman subcutaneously vs. soman control respectively, but it had no influence on the concentration of free P(-)soman in brain. Isotope trace experiments showed that it could significantly increase the distribution amount of bound [3H]soman in mice plasma and small intestine during 0-120 min after mice received [3H]soman (0.544 GBq.119 microg x kg(-1), sc) compared to soman control group.

Influence of portal vein and liver artery ligation on the toxicokinetics of soman in rabbits.

The portal vein, liver artery ligation treatment and the portal vein ligation treatment could increase the concentration of P(-) soman in rabbit blood 3.6-19.3 times as compared with soman control group at each time points after soman injection (43.2 microgkg(-1), i.v.). Toxicokinetics parameters showed that portal vein, liver artery ligation treatment and portal vein ligation treatment could reduce the clearance (CL) and distribution volume (V(d)). Meanwhile, they could significantly increase the AUC of soman in rabbits from 2.08+/-0.154 to 18.2+/-2.96 and 22.9+/-3.73 mg s l(-1), respectively. All these data showed that the liver and intestine play a very important role on elimination the free soman in rabbit's blood at high dosing of soman.

Effects of pretreatment with verapamil on the toxicokinetics of soman in rabbits and distribution in mouse brain and diaphragm.

The effects of verapamil on the elimination of soman in rabbit blood and distribution in mouse brain and diaphragm by determining the concentration of P(-)soman using the chirasil capillary gas chromatographic analysis method were studied in order to study the effects of verapamil on the metabolic detoxification of soman. Verapamil (10 mg kg(-1), im, 30 min before soman administration) could significantly reduce the concentration of P(-)soman in rabbit blood at 15, 60, 90, 120, 180 and 240 s after soman injection (43.2 microg kg(-1), iv) as compared to soman-treated control animal respectively. Toxicokinetics parameters showed verapamil could increase clearance rate from 20.8+/-1.51 to 44.3+/-7.0 ml kg(-1)s(-1) and reduce AUC of P(-)soman from 2.08+/-0.151 to 0.996+/-0.172 mg s l(-1). For experiments in mice, verapamil could reduce the concentration P(-)soman in diaphragm from 74.7, 70.5, 88.7 to 41.1, 39.0, 49.3 ng g(-1) at the time of 30, 90, 120 s after intoxication of soman subcutaneously vs. soman control respectively, but it had no influence on the concentration of free P(-)soman in brain. Verapamil accelerated the elimination of P(-)soman in the rabbits blood and reduced the distribution of P(-)soman in the mouse diaphragm.

[Stability studies of sulfated polyguluronic acid ester].

AIM: To test the stability of marine polysaccharide drug sulfated polyguluronic acid ester. METHODS: Four methods including high performance gel chromatography (HPGC), poly-acrylamide gel electrophoresis (PAGE), UV scan of absorbance between 200 and 800 nm and gelatin nephelometry were established. Samples were tested in high temperature, high humidity, strong light and accelerated test conditions. The methods were used to test the changes of the parameters including molecular weight, molecular weight distribution, absorbance between 200 and 800 nm, free sulfate, with which we could estimate the stability of sulfated polyguluronic acid ester could be estimated. RESULTS: The four methods were suitable to test the stability of sulfated polyguluronic acid ester and the sample were stable in the conditions as before except in high temperature. CONCLUSION: Sulfated polyguluronic acid ester has good stability.