Preparation of a Peptide-Modified Electrode for Capture and Voltammetric Determination of Endotoxin

Endotoxin is the major structural constituent of the outer membrane of Gram-negative bacteria, which is a great threat to human health. Herein, a sensitive electrochemical biosensor for the detection of endotoxin is established by recording the voltammetric responses of the peptide-modified electrode. The utilized peptide has a high affinity for the target endotoxin, which ensures the high selectivity of this method. After the capture of endotoxin on the electrode surface, a negatively charged layer is formed, and the electron-transfer process is significantly hindered because of the increased steric hindrance and the electrostatic repulsion. The declined electrochemical signal could be used to indicate the concentration of endotoxin. This method is simple but effective, which requires limited reagents. Another highlight of this method is its user-friendly operation. Moreover, its applicability in human blood plasma promises its great potential utility in the near future.

LncRNA625 modulates prostate cancer cells proliferation and apoptosis through regulating the Wnt/β-catenin pathway by targeting miR-432

OBJECTIVE

Prostate cancer (PCa) is the second leading contributor to male malignancy-associated death in developed countries. The study aimed to evaluate the effects of lncRNA625/miR-432 on the prostate cancer cells and the underlying molecular mechanism.

PATIENTS AND METHODS

The cell proliferation was detected using the MTT and colony formation, and cells apoptosis and cell cycle were analyzed with the flow cytometry. Luciferase reporter assay was carried out to detect the correlation between miR-432 and TRIM29 and PYGO2. Besides, reverse transcription-PCR and Western blot were performed to detect the mRNA and protein levels in prostate tissues and PC3 cells.

RESULTS

lncRNA625 and miR-432 levels were consistently reduced in the PCa tissues compared with the healthy control and lncRNA625 levels significantly affect the miR-432 expression in PC3 cells, indicating that miR-432 is a direct target of lncRNA625. Besides, lncRNA625 overexpression could inhibit the cancer cells growth, arresting cell cycle progression at the G1/S phase, and significantly induce apoptosis of PC3 cells, but reversed by the miR-432 inhibitor. Most importantly, we further found that miR-432 could deactivate Wnt/β-catenin pathway via suppressing TRIM29 and PYGO2 directly.

CONCLUSIONS

lncRNA625 could functionally inhibit PC3 cells proliferation and promote cells apoptosis through regulating the Wnt/β-catenin pathway by targeting miR-432.

Timing-dependent LTP and LTD in mouse primary visual cortex following different visual deprivation models

Visual deprivation during the critical period induces long-lasting changes in cortical circuitry by adaptively modifying neuro-transmission and synaptic connectivity at synapses. Spike timing-dependent plasticity (STDP) is considered a strong candidate for experience-dependent changes. However, the visual deprivation forms that affect timing-dependent long-term potentiation(LTP) and long-term depression(LTD) remain unclear. Here, we demonstrated the temporal window changes of tLTP and tLTD, elicited by coincidental pre- and post-synaptic firing, following different modes of 6-day visual deprivation. Markedly broader temporal windows were found in robust tLTP and tLTD in the V1M of the deprived visual cortex in mice after 6-day MD and DE. The underlying mechanism for the changes seen with visual deprivation in juvenile mice using 6 days of dark exposure or monocular lid suture involves an increased fraction of NR2b-containing NMDAR and the consequent prolongation of NMDAR-mediated response duration. Moreover, a decrease in NR2A protein expression at the synapse is attributable to the reduction of the NR2A/2B ratio in the deprived cortex.

[Effects of alginate/collagen scaffold on cell proliferation and differentiation of human adipose-derived mesenchymal stem cells]

Objective: To build scaffold materials with different concentrations of alginate and collagen, and to observe the effects of alginate/collagen ratio on the proliferation of human adipose-derived mesenchymal stem cells (hAMSC) and osteogenic differentiation. The optimal concentration of alginate/collagen will be chosen for constructing hydrogel that will be used for bone tissue engineering. Methods: Soluble hydrogel scaffold materials containing alginate/collagen were prepared, and the following groups were established based on different alginate/collagen ratio: 4∶1 (group A), 2∶1 (group B), and 1∶1 (group C). Cell proliferation on the material surface was observed using the cell counting kit-8 (CCK-8) assay, while cell viability in each material group were observed using live/dead staining. Quantitative real-time PCR(qPCR) was used to measure the differential expression of osteogenesis-related genes on and in the materials. Immunofluorescence staining was used to measure the differential gene expression of osteogenesis-related proteins in each group. Results: The results from the CCK-8 assay showed increasing cell proliferation rate on the lyophilized hydrogel material surface as the collagen concentration increased, and the highest cell proliferation was observed in group C. Live/dead staining assay indicated that cells were able to proliferate in all three types of hydrogel materials, and the highest cell viability was found in material from group B ([87.50±2.65]%). qPCR showed that the expression of osteogenesis-related genes in group C was the highest, among the three groups, while the expression of osteocalcin in group B was significantly higher than those in the other two groups (P<0.05). Immunofluorescence staining was carried out for osteocalcin on and in the hydrogel material and the results were consistent with that of qPCR. Conclusions: The alginate/collagen scaffold materials did not show adverse effects on the cell proliferation of hAMSC and osteogenenic differentiation. Bone tissue engineering can use 10% hydrogel material, and when the sodium alginate and collagen have a ratio of 2∶1, the hydrogel can be conducive to cell differentiation and proliferation.

The expression of SIRT3 in primary hepatocellular carcinoma and the mechanism of its tumor suppressing effects

OBJECTIVE

To observe the SIRT 3 expression in primary hepatocellular carcinoma (HCC), and then establish the eukaryotic expression vector of SIRT3 to observe the proliferation and apoptosis of pZsGreen-c1-SIRT3 HepG2 cells. Furthermore, we explored the mechanism of SIRT3 in inhibiting HCC.

PATIENTS AND METHODS

Immunohistochemistry was used to detect the expression of SIRT3 in the tumor tissue and para-tumor tissue in 32 patients with HCC and the normal liver tissue in 10 patients. The mRNA of SIRT3 from the normal liver tissue was used as a template, reverse transcription-polymerase chain reaction (RT-PCR) was used to obtain the total sequence of SIRT3 gene, and then the gene was cloned and combined with vector pZsGreen-c1, liposome transfection technology was used to transfect the recombined plasmid into HepG2. The cells were divided into three groups: group A (HepG2 cells as a blank control group), group B (pZsGreen-c1 HepG2 cells as an experimental control group) and group C (pZsGreen-c1-SIRT3 HepG-2 cells as an experimental group). MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay was used to detect the growth and proliferation of cells in 3 groups; annexinV/PI double staining was used to detect the apoptotic rates of cells in 3 groups. Western blot was used to detect the protein expression of SIRT3, Fas, Bax and P53, and water-soluble tetrazolium salt (WST-1) was used to detect MnSOD content in 3 groups.

RESULTS

Immunohistochemistry results showed that SIRT3 in the tumor tissue sample was positive in 19 patients out of 32 HCC patients; however, there was no strong positive case, the positive rate of SIRT3 expression was 59.38% (19/32). SIRT3 in the para-tumor tissue was positive in 31 HCC patients, the positive rate was 96.88% (31/32), and 18 cases were strongly positive; SIRT3 in normal liver tissue was positive in all 10 cases, the positive rate was 100.0% (10/10), and 7 cases were strongly positive. The differences of SIRT3 positive rate and positive score in tumor tissue from para-tumor tissue and normal liver tissue were statistically significant (p<0.05). However, the differences between para-tumor tissue and normal liver tissue were not statistically significant (p>0.05). After pZsGreen-c1-SIRT3 transfection, MTT results showed that the OD values in 3 groups were increased with the time, showing time-dependent manner. At 48 h after culture, the OD values in-group C were significantly different from group A and B, and the inhibitory rates were statistically different (p<0.05). After 48 h, the OD values and inhibitory rates in-group C showed that the cells were obviously inhibited, and the inhibitory rates were increased with the time, showing time-dependent manner. Flow cytometry results showed that the cell numbers of early stage apoptosis and late stage apoptosis were significantly increased in group C, which was significantly higher than group A and B, the differences were statistically significant (p<0.01). Western blot results showed that expression levels of SIRT3, p53, Bax and Fas were not different between group A and B (p>0.05); SIRT3, p53, Bax and Fas in group C were significantly increased, which were statistically higher than group A and B (p<0.01). WST-1 results showed that MnSOD contents were not statistically different between group A and B (p>0.01). MnSOD content in-group C was significantly higher than the other groups, which were statistically significant (p<0.01).

CONCLUSIONS

SIRT3 shows low expression or deficiency in HCC tissue, indicating that SIRT3 expression can affect the occurrence and development of HCC. SIRT3 can inhibit the growth and proliferation of HepG2 cells and induce HepG2 cell apoptosis. The mechanism may be related to the up-regulation of MnSOD and p53, the up-regulation of Bax and Fas by MnSOD.

Characteristics and computed tomography evaluation of primary retroperitoneal tumours: report of 113 cases

INTRODUCTION Benign and malignant primary retroperitoneal tumours (PRT) have different clinical manifestations and pathological characteristics. We explore the characteristics and evaluate the value of computed tomography (CT) for PRT. METHODS Fifty-six benign and fifty-seven malignant PRT with clinical, radiographic and surgical data were retrospectively investigated. Statistical analysis was carried out using SPSS software. RESULTS We found that mean size of benign tumours was 12.4 ± 7.7cm but 20.7 ± 11.6cm in malignant cases (P < 0.05). The accuracy of CT localisation was approximately 70%. The sensitivity and specificity of CT diagnosis for benign tumours were 96% and 85%, respectively; 51 (91%) underwent complete resection among benign cases but 42 (74%) in malignant cases (P < 0.05). Sensitivity of CT evaluation for invaded organs and vessels was 50% and 65%, respectively, and specificity was 88% and 81%, respectively. CONCLUSIONS Large size, no capsule, irregular margin, heterogeneous density and specific enhancement pattern on CT are highly suggestive of malignancy. CT is the most useful tool in assessing the size and characteristics of PRT but it does not have the sensitivity to assess the involvement of organs and vessels.

Association of polymorphisms in intron 2 of FGFR2 and breast cancer risk in Сhinese women

Recent genome-wide association studies (GWAS) demonstrated that genetic variation in intron 2 of fibroblast growth factor receptor 2 (FGFR2) was a novel risk for breast cancer. We investigated whether two SNPs rs1219648 and rs2981582 in intron 2 of FGFR2 were associated with the risk of breast cancer in Chinese women. A total of 340 female breast cancer patients and 400 normal age-matched controls were recruited. Two SNPs were genotyped using matrix-assisted laser desorption/ionization mass spectrometry. The two SNPs rs1219648 and rs2981582 showed no association with the risk of breast cancer. A subgroup analysis by menopausal status demonstrated that the distribution of rs2981582 T alleles, including CT and TT genotypes, was significantly higher in premenopausal patients compared with postmenopausal patients. The TT genotype in rs2981582 was more strongly associated with ER-positive than with ER-negative tumors by ER status analysis. Analysis by haplotypes showed that no haplotypes associated with breast cancer. The results showed no association between two SNPs, rs1219648 and rs2981582 and breast cancer risk, although in a stratified analysis rs2981582 strongly associated with premenopausal and ER-positive breast cancer patients in Chinese women.

Exome sequencing identifies highly recurrent somatic GATA2 and CEBPA mutations in acute erythroid leukemia

Acute erythroid leukemia (AEL), characterized by a predominant erythroid proliferation, is a subtype of acute myelogenous leukemia. The genetic basis of AEL remains poorly defined. Through whole-exome sequencing, we identified high frequencies of mutations in CEBPA (32.7%), GATA2 (22.4%), NPM1 (15.5%), SETBP1 (12.1%) and U2AF1 (12.1%). Structure prediction analysis revealed that most of the GATA2 mutations were located at the DNA-binding N-terminal zinc-finger near the DNA-binding interface, suggesting that mutations could result in at least partial inactivation of GATA2 protein. On co-transfection of a GATA-responsive reporter construct together with plasmids expressing either GATA2 wild-type or GATA2 ZF1 mutants (P304H, L321P and R330X) in 293T cells, we found a reduced transcriptional activation in cells transfected with GATA2 mutants. To determine whether reduced GATA2 function is involved in leukemogenesis of AEL, we transfected 32D cells with GATA2 mutants and evaluated the impact of GATA2 mutations on erythroid differentiation. Our data revealed an increased expression of erythroid-related antigens Ter-119, β-globin and βh1-globin, as well as increased hemoglobin positivity in 32D cells transfected with GATA2 mutants compared with control cells. Our results suggest that the decline of GATA2 resulting from mutations contributes to the erythroid commitment, differentiation and the development of AEL.

The CHRM3 gene is implicated in abnormal thalamo-orbital frontal cortex functional connectivity in first-episode treatment-naive patients with schizophrenia

BACKGROUND

The genetic influences in human brain structure and function and impaired functional connectivities are the hallmarks of the schizophrenic brain. To explore how common genetic variants affect the connectivities in schizophrenia, we applied genome-wide association studies assaying the abnormal neural connectivities in schizophrenia as quantitative traits.

METHOD

We recruited 161 first-onset and treatment-naive patients with schizophrenia and 150 healthy controls. All the participants underwent scanning with a 3 T-magnetic resonance imaging scanner to acquire structural and functional imaging data and genotyping using the HumanOmniZhongHua-8 BeadChip. The brain-wide association study approach was employed to account for the inherent modular nature of brain connectivities.

RESULTS

We found differences in four abnormal functional connectivities [left rectus to left thalamus (REC.L-THA.L), left rectus to right thalamus (REC.L-THA.R), left superior orbital cortex to left thalamus (ORBsup.L-THA.L) and left superior orbital cortex to right thalamus (ORBsup.L-THA.R)] between the two groups. Univariate single nucleotide polymorphism (SNP)-based association revealed that the SNP rs6800381, located nearest to the CHRM3 (cholinergic receptor, muscarinic 3) gene, reached genomic significance (p = 1.768 × 10-8) using REC.L-THA.R as the phenotype. Multivariate gene-based association revealed that the FAM12A (family with sequence similarity 12, member A) gene nearly reached genomic significance (nominal p = 2.22 × 10-6, corrected p = 0.05).

CONCLUSIONS

Overall, we identified the first evidence that the CHRM3 gene plays a role in abnormal thalamo-orbital frontal cortex functional connectivity in first-episode treatment-naive patients with schizophrenia. Identification of these genetic variants using neuroimaging genetics provides insights into the causes of variability in human brain development, and may help us determine the mechanisms of dysfunction in schizophrenia.

Ion insertion into individual 7,7,8,8-tetracyanoquinodimethane nanoparticles

We report the quantification of partial ion insertion into individual 7,7,8,8-tetracyanoquinodimethane nanoparticles. It is shown that both potassium and sodium ions can be inserted into single TCNQ nanoparticles from aqueous solution. The extent of both potassium and sodium insertion into individual nanoparticles is quantitatively measured and shown to be partial and sodium ion shows a higher extent of insertion. The insertion process is inferred to be limited and controlled by the formation of a thin shell of salt, Na(+)/K(+) TCNQ˙(-) formed at the surface of the nanoparticle.

Subclinical hypothyroidism and the associations with macrovascular complications and chronic kidney disease in patients with Type 2 diabetes

AIMS

The prevalence of subclinical hypothyroidism (SCH) is high among patients with diabetes, although the relationship between SCH and diabetic vascular complications is unknown. This study aimed to determine the relationship between SCH and vascular complications in patients with Type 2 diabetes.

METHODS

In this cross sectional study, 991 patients with Type 2 diabetes were screened for thyroid function at their admission to the Second Affiliated Hospital of Chongqing Medical University. We compared the prevalence of coronary heart disease (CHD), ischaemic stroke and chronic kidney disease (CKD) with the prevalence of euthyroidism and SCH.

RESULTS

Among the 991 patients, 126 (12.7%) patients had SCH. The prevalence of CHD was significantly higher in the SCH group than in the euthyroid group (22.2% and 15.0%, respectively; P = 0.039). In the logistic regression analyses, SCH was associated with CHD [odds ratio (OR): 1.993; 95% confidence interval (CI): 1.135-3.497; P = 0.016]. This association was stronger in patients aged ≥ 65 years than in younger patients [2.474 (1.173-5.220); P = 0.017]. No significant association was found between SCH and ischaemic stroke. Patients with severe SCH had a high risk of CKD [1.842 (1.120-3.029); P = 0.016].

CONCLUSIONS

This study provides evidence that SCH in patients with Type 2 diabetes is associated with a high prevalence of CHD (and CKD in severe SCH), although not with ischaemic stroke.

Recent advances in carbon nanodots: synthesis, properties and biomedical applications

Herein, a mini review is presented concerning the most recent research progress of carbon nanodots, which have emerged as one of the most attractive photoluminescent materials. Different synthetic methodologies to achieve advanced functions and better photoluminescence performances are summarized, which are mainly divided into two classes: top-down and bottom-up. The inspiring properties, including photoluminescence emission, chemiluminescence, electrochemical luminescence, peroxidase-like activity and toxicity, are discussed. Moreover, the biomedical applications in biosensing, bioimaging and drug delivery are reviewed.

Echogenic intracardiac focus in fetus and association with maternal respiratory tract infection in Shanghai, China

PURPOSE OF INVESTIGATION

To evaluate the association between fetal echogenic intracardiac focus (EIF) and maternal respiratory tract infections (RTI) during gestation.

MATERIALS AND METHODS

Fetal echocardiography was performed on 1,720 pregnant women (1,723 fe- tuses), and 205 of them showed evidence of fetal EIF. Other 245 pregnancies without fetal EIF were selected randomly as a control group. Comparison was undertaken to evaluate the difference between these two groups, and the possible association between EIF and maternal RTI.

RESULTS

EIF was present in 11.9% of the examined fetuses, and the presence of fetal EIF with maternal RTI was significantly higher (p < 0.05) than those without RTI. Multivariate logistic regression correction of RTI showed that the likelihood of EIF was 49 fold higher in pregnant women with RTI than without it (odds ratio [OR] = 49.958, 95% confidence interval [CI], 25.973~96.092, p < 0.05).

CONCLUSIONS

Fetal EIF is suggested to be associated with maternal RTI during gestation in the present study population.

Doping of single polymeric nanoparticles

The oxidative doping of single poly(N-vinylcarbazole) (PVK) nanoparticles is reported in aqueous sodium perchlorate using the nanoimpact method. Complete oxidative doping of single PVK nanoparticles with a size of approximately 120 nm is demonstrated, showing for the first time a simple strategy to synthesize and characterize doped polymeric nanoparticles at the single nanoparticle level.

Initiation of active immunization against testosterone during early puberty alters negative feedback regulation of the hypothalamic-pituitary-testicular axis in rabbits

To investigate the effects of antitestosterone immunization, initiated during early puberty, on hypothalamic-pituitary-testicular feedback in rabbits, 16 early pubertal male rabbits were randomly allocated into 2 groups (n = 8), control or immunized against testosterone-3(O-carboxymethyl)oxime-BSA in Freund adjuvant at 4 mo of age (with a booster immunization 4 wk later). Blood samples (for antibody titers and hormone concentrations) were collected at 2- or 4-wk intervals after immunization. Compared with controls, antitestosterone immunization triggered: a substantial and sustained antibody response (P < 0.01); increases in serum concentrations of luteinizing hormone (LH) and testosterone and testis weight and volume (P < 0.05); hyperplasia of testicular interstitial tissue with clustered and hypertrophic Leydig cells; and greater (P < 0.05) enzyme protein and messenger RNA (mRNA) expression levels for testicular cholesterol side-chain cleavage cytochrome P-450, 17α-hydroxylase cytochrome P-450, and 3β-dydroxysteroid dehydrogenase. Furthermore, immunoneutralization of testosterone upregulated mRNA expressions for genes in sex steroid negative feedback loops, including androgen receptor (AR), estrogen receptor alpha (ER-α), kisspeptin encoded gene (kiss-1) and kisspeptin receptor (G-coupled receptor 54) and gonadotropin-releasing hormone (GnRH) in the hypothalamic arcuate nucleus, GnRH receptor and LH-β in pituitary, and AR, inhibin-α and βA subunits in testes (P < 0.05). However, immunization did not affect mRNA expressions for follicle-stimulating hormone β, AR, and ER-α in pituitary, or ER-α in testes. We concluded that antitestosterone immunization in male rabbits, initiated during early puberty, increased GnRH mRNA expression, and in turn LH synthesis by reducing testicular feedback signaling. Reduction of direct steroidal effects on the testis may also have increased testosterone secretion. Consequently, there was an accelerated testicular development during puberty and enhanced testicular function after puberty, which likely conferred prolonged reproductive advantages.

A comparison of the efficacy of surgical renal denervation and pharmacologic therapies in post-myocardial infarction heart failure

Objective

Although renal denervation (RD) has been shown to be effective in treating post- myocardial Infarction (MI) heart failure (HF) in animal models and clinical trials, its utility as a standalone treatment without traditional drug treatment for post-MI HF still needs to be investigated.

Methods

Rats were randomly assigned into seven experimental groups: N group (control group with no MI and no RD, n = 10), MI group (MI, n = 20), RD group (renal denervation, n = 10), RD-3d+MI group (RD performed three days before MI, n = 15), β-blocker-3d+MI group (Metoprolol treated three days before MI, n = 15), ACEI-3d+MI group (Perindopril treated three days before MI, n = 15), and ARB-3d+MI group (Losartan treated three days before MI, n = 15). Cardiac function, autonomic nervous system parameters, and neuroendocrine activities were evaluated 8 weeks post MI.

Results

Compared to β-blockers, ACEIs, and ARBs, RD alone provided significantly better cardiac remodeling and function, enhanced water and sodium excretion, and improved autonomic modulation.

Conclusions

In this post-MI HF animal model, surgical RD provides effective autonomic modulation, inhibition of the RAAS, improved cardiac remodeling, and preserved renal function, without affecting normal circulation and cardiopulmonary function in normal rats. Compared to β-blocker, ACEI, and ARB single-drug therapies, RD alone is more efficacious. These results suggest that RD may be an effective treatment option for HF, especially in patients who have contraindications to drug therapy.