Identification Strategy of Biological Half Sibling Relationship.

OBJECTIVES: To compare the application value of the likelihood ratio (LR) method and identity by state (IBS) method in the identification involving half sibling relationships, and to provide a reference for the setting of relevant standards for identification of half sibling relationship. METHODS: (1) Based on the same genetic marker combinations, the reliability of computer simulation method was verified by comparing the distributions of cumulated identity by state score (CIBS) and combined full sibling index in actual cases with the distributions in simulated cases. (2) In different numbers of three genetic marker combinations, the simulation of full sibling, half sibling and unrelated individual pairs, each 1 million pairs, was obtained; the CIBS, as well as the corresponding types of cumulative LR parameters, were calculated. (3) The application value of LR method was compared with that of IBS method, by comparing the best system efficiency provided by LR method and IBS method when genetic markers in different amounts and of different types and accuracy were applied to distinguish the above three relational individual pairs. (4) According to the existing simulation data, the minimum number of genetic markers required to distinguish half siblings from the other two relationships using different types of genetic markers was estimated by curve fitting. RESULTS: (1) After the rank sum test, under the premise that the real relationship and the genetic marker combination tested were the same, there was no significant difference between the simulation method and the results obtained in the actual case. (2) In most cases, under the same conditions, the system effectiveness obtained by LR method was greater than that by IBS method. (3) According to the existing data, the number of genetic markers required for full-half siblings and half sibling identification could be obtained by curve fitting when the system effectiveness reached 0.95 or 0.99. CONCLUSIONS: When distinguishing half sibling from full sibling pairs or unrelated pairs, it is recommended to give preference to the LR method, and estimate the required number of markers according to the identification types and the population data, to ensure the identification effect.

Rapid biosynthesis of fluorescent CdSe QDs in Bacillus licheniformis and correlative bacterial antibiotic change assess during the process.

Cadmium selenide (CdSe) quantum dots (QDs) were biosynthesized rapidly in 18 h in Bacillus licheniformis ATCC 11946 (B. licheniformis); this process benefited from the cellular machinery of bacteria metal metabolism, in which inorganic Na2 SeO3 and CdCl2 were chosen as raw materials to produce high quality CdSe QDs by a designed two-step protocol. Research outcomes demonstrated that the purified CdSe QDs possessed maximum fluorescence intensities at weak alkalinity solutions and had good fluorescence stabilities at 4°C as well as at room temperature after standing for 1 week. Glutathione (GSH) concentration and superoxide dismutase (SOD) content, both of which were reported to be greatly related to biosynthetic activities in some bacterial matrices, were monitored during the biosynthetic process in B. licheniformis. Bacterial resistance research further showed that the change in rates in bacterial inhibition zone diameter to seven different antibiotics was less than 9% after B. licheniformis was used to manufacture CdSe QDs, showing a relative lower environmental risk in short-term heavy metal exposure.

Efficacy of low-dose versus high-dose simethicone with polyethylene glycol for bowel preparation: A prospective randomized controlled trial.

BACKGROUND AND AIM: Additional simethicone (SIM) can improve adequate bowel preparation and adenoma detection rate (ADR). However, there is no consensus on the optimal dose of SIM. In this study, we compared the adequate bowel preparation rate with supplementation of split-dose 2 L polyethylene glycol (PEG) with low-dose SIM (200 mg) versus high-dose SIM (1200 mg). METHODS: This was a prospective, randomized, observer-blinded trial involving consecutive subjects undergoing colonoscopy. The primary outcome was adequate bowel preparation as assessed by Boston Bowel Preparation Scale (BBPS) score. RESULTS: Four hundred subjects were randomly allocated to low-dose SIM or high-dose SIM group. Baseline characteristics were comparable in the two groups (P > 0.05). No significant between-group differences were observed with respect to total bubble scale (BS) (8.49 ± 1.00 vs 8.39 ± 1.10, P = 0.07), total BBPS score (8.70 ± 0.81 vs 8.29 ± 1.18, P = 0.98), ADR (33.68% vs 31.79%, P = 0.69) or withdrawal time (13 [range, 10-16] min vs 13 [10-15] min, P = 0.96). The intubation time in low-dose SIM group was significantly shorter than that in high-dose SIM group (8 (4-16) min vs 10 [6-17] min, P = 0.04). In addition, BS scores as well as diminutive ADR in right colon were superior in the low-dose SIM group (2.68 ± 0.59 vs 2.52 ± 0.73, P = 0.03 and 54.29% vs 30.30%, P = 0.046, respectively). CONCLUSION: Addition of low-dose SIM to split-dose 2 L PEG was as effective as addition of high-dose SIM with respect to adequate bowel preparation, ADR and patient tolerance. However, low-dose SIM was superior with respect to intubation time, right colon BS scores, right colon diminutive ADR and cost savings.

Construction of photodynamic-effect immunofluorescence probes by a complex of quantum dots, immunoglobulin G and chlorin e6 and their application in HepG2 cell killing.

In this study, tri-functional immunofluorescent probes (Ce6-IgG-QDs) based on covalent combinations of quantum dots (QDs), immunoglobulin G (IgG) and chlorin e6 (Ce6) were developed and their photodynamic ability to induce the death of cancer cells was demonstrated. Strategically, one type of second-generation photosensitizer, Ce6, was first coupled with anti-IgG antibody using the EDC/NHS cross-linking method to construct the photosensitive immunoconjugate Ce6-IgG. Then, a complex of Ce6-IgG-QDs immunofluorescent probes was obtained in succession by covalently coupling Ce6-IgG to water soluble CdTe QDs. The as-manufactured Ce6-IgG-QDs maintained the bio-activities of both the antigen-antibody-based tumour targeting effects of IgG and the photodynamic-related anticancer activities of Ce6. By way of polyclonal antibody interaction with rabbit anti-human epidermal growth factor receptor (anti-EGFR antibody, N-terminus), Ce6-IgG-QDs were labelled indirectly onto the surface of human hepatocarcinoma (HepG2) cells in cell recognition and killing experiments. The results indicated that the Ce6-IgG-QDs probes have excellent tumour cell selectivity and higher photosensitivity in photodynamic therapy (PDT) compared with Ce6 alone, due to their antibody-based specific recognition and location of HepG2 cells and the photodynamic effects of Ce6 killed cells based on efficient fluorescence resonance energy transfer between QDs and Ce6. Copyright © 2015 John Wiley & Sons, Ltd.

PXR polymorphisms and their impact on pharmacokinetics/pharmacodynamics of repaglinide in healthy Chinese volunteers.

PURPOSE: CYP3A4 is the main isoform of cytochrome P450 oxidases involved in the metabolism of approximately 60 % drugs, and its expression level is highly variable in human subjects. CYP3A4 is regulated by many transcription factors, among which the pregnane X receptor/steroid and xenobiotic receptor (PXR/SXR, NR1I2) have been identified as the most critical. Genetic polymorphisms (such as SNPs) in PXR may affect the expression level of CYP3A4. Although numerous SNPs have been identified in PXR and have appeared to affect PXR function, their impact on the expression of CYP3A4 in human subjects has not been well studied. Thus, a clinical study in healthy Chinese subjects was conducted to investigate the impact of PXR polymorphisms on repaglinide (an endogenous marker for CYP3A4 activity) pharmacokinetics used alone or in combination with a PXR inducer, flucloxacillin. METHOD: Two SNPs, -298A>G and 11193T>C, were identified as the tag SNPs to represent the overall genetic polymorphic profile of PXR. To evaluate the potential functional change of these two SNPs, 24 healthy subjects were recruited in a pharmacokinetics/pharmacodynamics study of repaglinide with or without flucloxacillin. RESULTS: The pharmacokinetic parameters including AUC and T1/2 were significantly different among the PXR genotype groups. The SNPs of -298G/G and 11193C/C were found to be associated with a lower PXR activity resulting in reduction of CYP3A4 activity in vivo. After administration of flucloxacillin, a significant drug-drug interaction was observed. The clearance of repagnilide was significantly increased by concomitant flucloxacillin in a genotype dependent manner. The subjects with SNPs of -298G/G and 11193C/C appeared to be less sensitive to flucloxacillin. CONCLUSION: Our study results demonstrated for the first time the impact of genetic polymorphisms of PXR on the PK and PD of repaglinide, and showed that subjects with genotype of -298G/G and 11193C/C in PXR has a decreased elimination rate of 3A4/2C8. Furthermore, flucloxacillin was able to induce 3A4/2C8 expression mediated by PXR in a genotype dependent manner.

[Induction cell damage and change of nuclear factor-kappa B expression by bromoxynil in SH-SY5Y cells].

OBJECTIVE: To investigate the cytotoxicity of bromoxynil on SH-SY5Y cells and its effect on the expression of nuclear factor-kappa B (NF-κB) and I kappa B alpha (IκBα) in SH-SY5Y cells. METHODS: SH-SY5Y cells were exposed to bromoxynil (10, 50, or 100 µmol/L) for 24 and 48 h, and other SH-SY5Y cells, which were used as a control, were exposed only to dimethyl sulfoxide. After 24 and 48 h of exposure, the morphological changes of these cells were observed under an inverted microscope, and the cytotoxicity of bromoxynil was measured by MTT assay. The cellular proliferation was examined by cell counting after 12, 24, 48, 72, and 96 h of exposure. After 24 h of exposure, the expression of NF-κB was evaluated by Western blot and immunocytochemistry, and the expression of IκBα was evaluated by Western blot. RESULTS: The cellular proliferation inhibition rates (CPIRs) of 50 and 100 µmol/L groups were significantly higher than that of the control group after 24 and 48 h of exposure (P < 0.05); the CPIR was significantly higher after 48 h than after 24 h in the two groups (P < 0.05). The growth curve revealed that these groups began to show differences in cell count at the 24th of exposure and that the differences were even more marked as the exposure went on (F = 17.15, P < 0.05). The control group had a significantly increased cell count at the 48th, 72nd, and 96th h of exposure (P < 0.05); the 10 and 50 µmol/L groups had a significantly increased cell count at the 72nd and 96th h of exposure (P < 0.05); the 100 µmol/L group showed no significant change in cell count during 96h of exposure. The 50 and 100 µmol/L groups hada significantly longer cell doubling time than the control group (P < 0.05). The immunocytochemistry showed that as the dose of bromoxynil increased, the brownish yellow particles in the cytoplasm and nuclei became darker, the expression of NF-κB was upregulated, and the nuclear translocation of NF-κB was increased. The Western blot showed that the 100 µmol/L group had significantly higher expression of NF-κB in the nuclei than the control group (P < 0.05) and that the 50 and 100 µmol/L groups had significantly lower expression of IκBα in total proteins than the control group (P < 0.05). CONCLUSION: Bromoxynil can inhibit the proliferation of SH-SY5Y cells under this experimental condition, which may be related to activation of NF-κB.

[Study on mechanism of trimethyltin chloride-induced apoptosis in PC12 cells].

OBJECTIVE: To investigate the effects of trimethyltin chloride (TMT) on proliferation, apoptosis, oxidative damage, and NF-κB expression in PC12 cells in vitro. METHODS: PC12 cells were treated with 0, 0.3125, 0.6250, 1.2500, 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 24 and 48 h, and MTT assay was used to evaluate cell viability. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 12 and 24 h, and flow cytometry was used to measure the apoptotic rates of cells. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 6 h, and the reactive oxygen species (ROS) and glutathione (GSH) levels were measured. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 12 h, and Western blot was used to measure NF-κB levels. RESULTS: Compared with solvent controls, the PC12 cells treated with 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 24 h showed significantly decreased cell viability (P < 0.05); the PC12 cells treated with 1.2500, 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 48 h showed significantly decreased cell viability (P < 0.05). The PC12 cells treated with 1.2500, 2.5000, 5.0000, and 10.0000 µmol/L TMT for 12 h had apoptotic rates of 15.30% ± 0.75%, 18.90% ± 0.61%, 22.00% ± 0.60%, and 36.50% ± 0.66%, respectively, and the PC12 cells treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 24 h had apoptotic rates of 28.6% ± 0.40%, 43.54% ± 2.00%, 65.73% ± 0.71%, and 74.67% ± 0.40%, respectively, all significantly higher than those of the control group (12 h: 12.80% ± 1.00%, 24h: 16.83% ± 0.25%) (P < 0.05). The ROS fluorescence intensities of the PC12 cells treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT were 1.42, 1.71, 1.78, and 1.89 times that of the control group (P < 0.05); the PC12 cells treated with 2.50, 5.00, and 10.00 µmol/L TMT had GSH levels of 0.17 ± 0.0, 0.20 ± 0.04, and 0.07 ± 0.03 µmol/µg protein, significantly lower than that of the control group (0.30 ± 0.01 µmol/L protein) (P < 0.05). The PC12 cells treated with 2.50, 5.00, and 10.00 µmol/L TMT had significantly higher expression of NF-κB p65 than the control group (P < 0.05). CONCLUSION: Under our laboratory conditions, TMT can significantly inhibit proliferation and induce apoptosis in PC12 cells, which may be related to oxidative stress and NF-κB signaling pathway activation.

A sensitive and simple method for detecting Cu2+ in plasma using fluorescent Bacillus amyloliquefaciens containing intracellularly biosynthesized CdSe quantum dots.

Bacillus amyloliquefaciens containing intracellularly biosynthesized cadmium selenide (CdSe) quantum dots (QDs) was used as a fluorescent bioprobe. Several parameters in the QD biosynthesis process were systematically optimized. The optimized protocol for producing high-quality CdSe QDs in B. amyloliquefaciens features mild synthetic conditions, good reproducibility, short reaction time and high yield. This process shows promise for the mass production of QDs by bacterial matrices. The resultant fluorescent B. amyloliquefaciens containing intracellular CdSe QDs was used as a bioprobe for the simple detection of copper (II) ions in blood plasma. The selective permeability of the bacterial cell membrane along with the protection provided by a protein envelope on the QD surface prevented interference by other components of blood plasma, resulting in the accurate determination of Cu2+. Using the copper addition method, the content of Cu2+ in human blood plasma samples was determined to be 15.6-18.5 µmol/L, consistent with atomic absorption spectroscopy results. The technique developed here shows potential for the simple determination of Cu2+ in plasma with excellent selectivity and good sensitivity.

Fluorescent CdSe QDs containing Bacillus licheniformis bioprobes for Copper (II) detection in water.

Quantum dots (QDs) are semiconductor nanoparticles (NPs) that offer valuable functionality for cellular labeling, drug delivery, solar cells and quantum computation. In this study, we reported that CdSe QDs could be bio-synthesized in Bacillus licheniformis. After optimization, the obtained CdSe QDs exhibited a uniform particle size of 3.71±0.04nm with a maximum fluorescence emission wavelength at 550nm and the synthetical positive ratio can reach up to 87%. Spectral properties, constitution, particle sizes and crystalline phases of the CdSe QDs were systematically and integrally investigated. The CdSe QD-containing Bacillus licheniformis cells were further used as whole fluorescent bio-probes to detect copper (II) (Cu2+) in water, which demonstrated a low limit of detection (0.91µM). The assay also showed a good selectivity for Cu2+ over other ions including Al3+, Cd2+, Mg2+, K+, Na+, NH4+, Zn2+, CH3COO+, Pb2+ and I-. Our study suggests the fluorescent CdSe QDs-containing Bacillus licheniformis bio-probes as a promising approach for detection of Cu2+ in complex solution environment.

Eco-friendly intracellular biosynthesis of CdS quantum dots without changing Escherichia coli's antibiotic resistance.

In the paper, a green and efficient biosynthetical technique was reported for preparing cadmium sulfide (CdS) quantum dots, in which Escherichia coli (E. coli) was chosen as a biomatrix. Fluorescence emission spectra and fluorescent microscopic photographs revealed that as-produced CdS quantum dots had an optimum fluorescence emission peak located at 470nm and emitted a blue-green fluorescence under ultraviolet excitation. After extracted from bacterial cells and located the nanocrystals' foci in vivo, the CdS quantum dots showed a uniform size distribution by transmission electron microscope. Through the systematical investigation of the biosynthetic conditions, including culture medium replacement, input time point of cadmium source, working concentrations of raw inorganic ions, and co-cultured time spans of bacteria and metal ions in the bio-manufacture, the results revealed that CdS quantum dots with the strongest fluorescence emission were successfully prepared when E. coli cells were in stationary phase, with the replacement of culture medium and following the incubation with 1.0×10-3mol/L cadmium source for 2 days. Results of antimicrobial susceptibility testing indicated that the sensitivities to eight types of antibiotics of E. coli were barely changed before and after CdS quantum dots were prepared in the mild temperature environment, though a slight fall of antibiotic resistance could be observed, suggesting hinted the proposed technique of producing quantum dots is a promising environmentally low-risk protocol.