Chip-scale alignment of long DNA nanofibers on a patterned self-assembled monolayer

Controlled alignment of long DNA nanofibers is challenging. This communication reports a method to align human genomic DNA with nearly unlimited length using lithographically produced micro-patterns of self-assembled monolayers (SAMs) with positively charged terminal groups. The micro-patterns act as local DNA reservoirs to supply DNAs for nanofiber formation, and can also stretch and align DNA nanofibers to form an ordered array by controlling the dewetting profile. By reducing the size and inter-patch distance of a micro-patch, a nearly uniform array of long DNA nanofibers can be patterned over a large area. A controlled motion of a DNA containing droplet allows for free patterning of DNA nanofibers and production of complex structures without a transfer process. Bending of DNA nanofibers due to local distortion of the contact line bridges more adjacent micro-patches and increases the chance of producing continuous nanofibers. The interplay between surface tension and electrostatic attraction of positively charged micro-patterns allows the production of long DNA nanofibers in a simple yet powerful way.

Clinical application of a gadolinium-based capsule as an MRI contrast agent in slow transit constipation diagnostics

BACKGROUND

As a traditional method for the assessment of colon dynamics, radio-opaque markers (ROMs) are limited in clinical use because of their ionizing radiation. We compared the accuracy and applicability of gadolinium-based capsules with ROMs in the measurement of colon dynamics in healthy controls and slow transit constipation (STC) patients.

METHODS

Seven patients with STC and nine healthy controls under a normal diet orally consumed ROMs and gadolinium-based capsules simultaneously. All subjects underwent X-ray and magnetic resonance imaging (MRI). Healthy control images were acquired at 12, 24, and 48 h, and STC patient images were acquired at 24, 48, and 72 h. The scores based on the position of the labeling capsules and ROMs in the colon and the colon transit times (CTTs) in the two groups were compared.

KEY RESULTS

The CTTs obtained via the ROMs were 34.7±17.4 and 67.3±6.5 h in the healthy controls and STC patients, respectively (P<.05). The CTTs obtained via MRI were 30.9±15.9 and 74.1±7.2 h in the healthy controls and STC patients, respectively (P<.05). The CTTs of the STC patients were significantly longer than the healthy controls. The correlation (r_s ) between the scores based on the position of the labeling capsule and ROMs in the healthy group and the STC patients was .880 (P<.05) and .889 (P<.05), respectively.

CONCLUSIONS AND INFERENCES

As a MRI contrast label, gadolinium-based capsules exhibit results comparable to ROMs in colon motility measurements.

[Mode of delivery among HIV-positive pregnant women in areas with high prevalence of HIV in China, 2007-2013]

OBJECTIVE

To describe the changing demographic profile over time of pregnant women diagnosed with HIV infection, and trends in mode of delivery and pregnancy outcome.

METHODS

An observational investigation was conducted based on a population of 1 128 HIV-positive pregnant women at eight sites in China in provinces with high prevalence of HIV among pregnant women and children between 2007 and 2013. The study area included Shangcai and Weishi counties in Henan province; Ruili and Longchuan counties and Linxiang prefecture in Yunnan province; Yining County in Xinjiang; and Lingshan county and Babu district in Guangxi province. Main outcome measures were maternal characteristics, mode of delivery, and related trends over time by Cochram-Mantel-Haenszel(CMH) χ(2)-test.

RESULTS

A total hospital delivery rate of 96.4% was reported. For each year during the period 2007-2013, hospital delivery rates were 95.1% (253/266), 94.8% (188/198), 93.7% (164/175), 98.8% (159/161), 98.6% (141/143), 97.4% (114/117), and 100.0% (68/68), respectively (χ(2)CMH=7.68, P=0.006). The neonatal survival rate increased by 0.7% incrementally from 2007 to 2013, with 98.5% (262/266), 99.0% (196/198), 99.4% (174/175), 99.4% (160/161), 100.0% (143/143), 100.0% (117/117), and 100.0% (68/68), respectively (χ(2)CMH=4.58, P=0.030). The proportions of vaginal deliveries in those years were 62.2% (166/266), 54.8% (109/198), 59.9% (105/175), 61.7% (100/161), 66.7% (96/143), 58.8% (69/117), and 66.7% (46/68), respectively (χ(2)CMH=1.19, P= 0.276). The average rate for midwives skilled in procedures such as artificial rupture of membranes and episiotomy was 37.8% (261/691), with proportions decreasing during the study period at 39.2% (65/166), 47.4% (52/109), 35.9% (38/105), 46.0% (46/100), 25.5% (25/96), 31.2% (22/69), and 28.3% (13/46), respectively (χ(2CMH)=6.76, P=0.009).

CONCLUSION

The annual rate of reported hospital delivery increased between 2007 and 2013, with a declining rate of skilled midwifery over the same period. Survival of neonates born to HIV-infected mothers in China has increased to nearly equivalent levels as those of developed countries.

Effect of Salvia miltiorrhiza and ligustrazine injection on myocardial ischemia/reperfusion and hypoxia/reoxygenation injury

Salvia miltiorrhiza and ligustrazine are traditional Chinese medicines that have been used in combination for treatment of cardiovascular disease, including coronary heart disease, cardiac angina and atherosclerosis in Asia, in particular, China. The present study aimed to determine the effect of S. miltiorrhiza and ligustrazine injection (SLI) on myocardial ischemia/reperfusion (I/R) and hypoxia/reoxygenation (H/R) injuries via the Akt serine/threonine kinase (Akt)-endothelial nitric oxide synthase (eNOS) signaling pathway. Male Sprague-Dawley rats were randomly assigned into six groups: i) Sham group; ii) I/R group; iii) Low-SLI group (6.8 mg/kg/day, i.p.); iv) Medium-SLI group (20.4 mg/kg/day, i.p.); v) High-SLI group (61.2 mg/kg/day, i.p.); vi) verapamil group (6 mg/kg/day, i.p.). Prior to surgery, the aforementioned groups were pretreated with a homologous drug once per day for 3 days. The effect of SLI following 35 min coronary artery occlusion and 2 h reperfusion was evaluated by determining infarct size, hemodynamics, biochemical values and histological observations. Additionally, cell viability, caspase-3 expression, B cell leukemia/lymphoma-2 (Bcl-2)/Bcl-2-associated X protein (Bax) ratio, phosphorylated (p-)Akt and p-eNOS were also investigated following 2 h simulated ischemia and 2 h simulated reperfusion in H9C2 cardiomyocyte cells. Pretreatment with SLI significantly improved cardiac function in a dose-dependent manner and reduced myocardial infarct size, creatine kinase, lactate dehydrogenase and malondialdehyde levels in blood serum. Additionally, myocardial histopathology changes in the rat model were also alleviated in SLI treatment groups. The present in vitro study revealed that treatment with SLI reduced the apoptotic rate of H9C2 cells by inhibiting the activation of caspase-3 and increasing the Bcl-2/Bax ratio. The effect of SLI was associated with increased phosphorylation of the survival kinase Akt at Ser473 and its downstream target eNOS following H/R. The present study determined that SLI may alleviate I/R injury in cardiomyocytes and inhibit apoptosis in rats by the activation of the Akt-eNOS signaling pathway, and downregulation of the expression levels of proapoptotic factors, including caspase-3.

Acetylshikonin from Zicao exerts antifertility effects at high dose in rats by suppressing the secretion of GTH

Zicao is being highlighted as a promising Chinese medicine due to all the beneficial effects that have been associated with its use. Unfortunately, studies on the toxicity of Zicao in different species are still missing and should be carried out. In this study, we investigated whether Acetylshikonin (AS) from Zicao has an anti-fertility effect through mating experiments and explored its underling mechanism. Sprague-Dawley rats received no treatment or were treated with 120, 360 or 1080 mg/kg AS extract by intragastric administration for 2 weeks. The rat pregnancy rate of the 1080 mg/kg dose group was significantly decreased relative to control group, while it recovered after a month of drug withdrawal, which indicated that the effect of antifertility is reversible. Serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels in rat were significantly decreased by AS. The secretion of FSH in rat anterior pituitary cells was decreased but the synthesis was not affected. AS reduced the number of developing follicle and mature follicle in rat ovarian cortical. Maybe all of these resulted from AS decreased the expression of synaptotagmin-1 and SNAP-25 which were the critical proteins of exocytosis. Our data suggested that AS at high dose can suppress the ability of pregnancy of the rats through decreasing serum FSH and LH levels by affecting exocytosis process of gonadotropic hormone (GTH).

Acetylshikonin from Zicao Prevents Obesity in Rats on a High-Fat Diet by Inhibiting Lipid Accumulation and Inducing Lipolysis

Various drugs have been developed to treat obesity, but these have undesirable secondary effects, and an efficient but non-toxic anti-obesity drug from natural sources is desired. This study investigated the anti-obesity effects and mechanisms of action of acetylshikonin (AS)—which is used in traditional Chinese medicine—in rats on a high-fat diet (HFD). Rats were fed a normal diet or an HFD; the latter group was received no treatment or were treated with 100, 300, or 900 mg/kg AS extract by intragastric administration for 6 weeks. In addition, 3T3-L1 adipocytes were treated with AS and the effects on adipogenesis and lipolysis were evaluated by western blot analysis of adipogenic transcription factors and lipid-metabolizing enzyme levels and the phosphorylation status of protein kinase (PK) A and hormone-sensitive lipase (HSL). AS prevented HFD-induced obesity including reduction in body weight, white adipose tissue content, liver mass, and serum triglyceride and free fatty acid levels in rats. It also suppressed the expression of adipogenic differentiation transcription factors and decreased the expression of the adipocyte-specific proteins HSL and adipose triglyceride lipase (ATGL). Furthermore, AS treatment induced lipolysis, leading to the release of glycerol and increased in PKA and HSL phosphorylation. These findings demonstrate that AS has anti-obesity effects in a rat model and may be a safe treatment for obesity in humans.

Environmentally Friendly Method: Development and Application to Carbon Aerogel as Sorbent for Solid-Phase Extraction

We developed two simple, fast, and environmentally friendly methods using carbon aerogel (CA) and magnetic CA (mCA) materials as sorbents for micro-solid-phase extraction (μ-SPE) and magnetic solid-phase extraction (MSPE) techniques. The material performances such as adsorption isotherm, adsorption kinetics, and specific surface area were discussed by N2 adsorption-desorption isotherm measurements, ultraviolet and visible (UV-vis) spectrophotometry, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HR-TEM). The experimental results proved that the heterogeneities of CA and mCA were well modeled with the Freundlich isotherm model, and the sorption process well followed the pseudo-second-order rate equation. Moreover, plant growth regulators (PGRs) such as kinetin (6-KT), 6-benzylaminopurine (6-BA), 2,4-dichlorophenoxyacetic acid (2,4-D), and uniconazole (UN) in a reservoir raw water sample were selected as the evaluation of applicability for the proposed μ-SPE and MSPE techniques using high performance liquid chromatography (HPLC). The experimental conditions of two methods such as the amount of sorbent, extraction time, pH, salt concentration, and desorption conditions were studied. Under the optimized conditions, two extraction methods provided high recoveries (89-103%), low the limits of detection (LODs) (0.01-0.2 μg L(-1)), and satisfactory analytical features in terms of precision (relative standard deviation, RSD, 1.7-5.1%, n=3). This work demonstrates the feasibility and the potential of CA and mCA materials as sorbents for μ-SPE and MSPE techniques. Besides, it also could serve as a basis for future development of other functional CAs in pretreatment technology and make them valuable for analysis of pollutants in environmental applications.

Synthesis and properties of a Cu(II) complexing pyrazole ligandoside in DNA

The development of metal base pairs is of immense importance for the construction of DNA nanostructures. Here we report the synthesis of a biaryl pyrazole-phenol nucleoside that forms in DNA a stable self-pair upon complexation of a Cu(II) ion. A sequence with five consecutive pyrazole nucleotides allows the complexation of five Cu(II) ions in a row.

Optimal conditions for "heat-conduct effect" in liver tissue during radiofrequency ablation

AIM

This study was conducted to optimize the "heat-conduct effect" to increase the efficacy of radiofrequency ablation (RFA) in the treatment of liver tumors.

METHODS

To simulate the "heat-conduct effect" caused by RFA, isolated pig livers were heated by an inserted metal tube through which water with different incoming temperatures was passed. The tissue temperature was measured within 5- and 10-mm radiuses. Further, changes in color and morphology of the tissue were recorded.

RESULTS

Using an incoming temperature of 70 °C, the effective ablation radius of 5 mm was achieved within 10 min. To expand the effective radius to 10 mm, the tube temperature needed to be maintained at above 80 °C for 40 min; alternatively, the tube temperature above 90 °C and heating time of 25 min were also sufficient.

CONCLUSION

To achieve the complete ablation in isolated liver within the 10 mm radius by "heat-conduct effect", the temperature of the heating center should be maintained above 80 - 90 °C with the exposure time of 25-40 min.

Nuclear factor κB (NF-κB) suppresses food intake and energy expenditure in mice by directly activating the Pomc promoter

AIMS/HYPOTHESIS

While chronic low-grade inflammation is associated with obesity, acute inflammation reduces food intake and leads to negative energy balance. Although both types of inflammation activate nuclear factor κB (NF-κB) signalling, it remains unclear how NF-κB activation results in opposite physiological responses in the two types of inflammation. The goal of this study was to address this question, and to understand the link between inflammation and leptin signalling.

METHODS

We studied the ability of NF-κB to modulate Pomc transcription, and how it impinges on signal transducer and activator of transcription 3 (STAT3)-mediated leptin signalling by using a combination of animal models, biochemical assays and molecular biology.

RESULTS

We report that suppression of food intake and physical movement with acute inflammation is not dependent on STAT3 activation in pro-opiomelanocortin (POMC) neurons. Under these conditions, activated NF-κB independently leads to increased Pomc transcription. Electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) experiments reveal that NF-κB v-rel reticuloendotheliosis viral oncogene homologue A (avian) (RELA [also known as p65]) binds to the Pomc promoter region between -138 and -88 bp, which also harbours the trans-acting transcription factor 1 (SP1) binding site. We found significant changes in the methylation pattern at this region and reduced Pomc activation under chronic inflammation induced by a high-fat diet. Furthermore, RELA is unable to bind and activate transcription when the Pomc promoter is methylated. Finally, RELA binds to STAT3 and inhibits STAT3-mediated promoter activity, suggesting that RELA, possibly together with forkhead box-containing protein 1 (FOXO1), may prevent STAT3-mediated leptin activation of the Pomc promoter.

CONCLUSIONS/INTERPRETATION

Our study provides a mechanism for the involvement of RELA in the divergent regulation of energy homeostasis in acute and chronic inflammation.

Characteristics of diagnosis and therapy of adolescent malignant ovarian tumors

BACKGROUND

To improve the early diagnosis rate of adolescent malignant ovarian tumors, avoid misdiagnosis, select proper therapy, avoid excessive therapy, and render therapy more tolerable.

MATERIALS AND METHODS

A comprehensive review of adolescent malignant ovarian tumors, such as types, difficulties of early diagnosis, therapeutic principles, prognosis, fertility preserving through the authors' clinical experience, with reference to Chinese and international literatures.

RESULTS AND CONCLUSION

The majority of adolescent malignant tumors are malignant germ cell, the malignancy is high and it is difficult to diagnose in the early stage, likely to be ignored. Their diagnosis is therefore fundamental, while selecting the most appropriate therapeutic approach that also considers fertility-sparing without compromising prognosis and avoiding over-treatment.

Potential metabolite markers of schizophrenia

Schizophrenia is a severe mental disorder that affects 0.5-1% of the population worldwide. Current diagnostic methods are based on psychiatric interviews, which are subjective in nature. The lack of disease biomarkers to support objective laboratory tests has been a long-standing bottleneck in the clinical diagnosis and evaluation of schizophrenia. Here we report a global metabolic profiling study involving 112 schizophrenic patients and 110 healthy subjects, who were divided into a training set and a test set, designed to identify metabolite markers. A panel of serum markers consisting of glycerate, eicosenoic acid, β-hydroxybutyrate, pyruvate and cystine was identified as an effective diagnostic tool, achieving an area under the receiver operating characteristic curve (AUC) of 0.945 in the training samples (62 patients and 62 controls) and 0.895 in the test samples (50 patients and 48 controls). Furthermore, a composite panel by the addition of urine β-hydroxybutyrate to the serum panel achieved a more satisfactory accuracy, which reached an AUC of 1 in both the training set and the test set. Multiple fatty acids and ketone bodies were found significantly (P<0.01) elevated in both the serum and urine of patients, suggesting an upregulated fatty acid catabolism, presumably resulting from an insufficiency of glucose supply in the brains of schizophrenia patients.

SU-E-J-108: Quantitative Analysis of Longitudinal Cognitive Impairment Due to Radiation Therapy Based on Automatic Segmentation of Hippocampus and Subcortical Structure

PURPOSE

In this study, we developed a quantitative analysis tool based on patient's longitudinal MR images to 1) measure the radiation dose received by each subcortical structure, 2) follow the change of volume and shape of each structure longitudinally. This tool provides a systematic approach to study the radiation therapy (and subsequent chemotherapy) associated with cognitive impairments.

METHODS

MRI scans of one patient taken before and after radiation therapy are demonstrated in this study. 3D Conformal radiation therapy was performed on RapidArc™. An open source MRI analysis tool, FMRIB's Integrated Registration and Segmentation Tool (FIRST), was used for segmentation. The images are registered to a standard template with expert-defined labeling for all sub-cortical structures, and the labeling of each structure is mapped back to the individual MRI space for segmentation. After the segmentation, the radiation dose map was coregistered to the MRI space to calculate the dose received by each structure.

RESULTS

For the structure that is contained within the radiation zone, we can calculate the total dose based on the volumetric distribution of radiation dose. For the structure that is outside the radiation field, we can calculate the distance from the radiation zone. We have demonstrated in this work that the analysis can be done for all segmented sub-cortical structures. The change of volume before and after radiation treatment can be analyzed, and the results can be correlated with the change of cognitive performance over time.

CONCLUSIONS

We presented an automated tool for efficient, quantitative and user-independent measurements of radiation dose in subcortical structures. The obtained results can be correlated with the cognitive test score and the clinical outcome to evaluate radiation and the subsequent chemotherapy induced changes in brain structures and functions.

Predictors of relapse in chronic hepatitis B after discontinuation of anti-viral therapy

BACKGROUND

Optimal duration of anti-viral therapy in chronic hepatitis B virus (HBV) infection remains unclear.

AIM

To investigate factors that could predict relapse after stopping anti-viral agents.

METHODS

Chronic hepatitis B patients who were treated with anti-viral agents (lamivudine, adefovir, entecavir) and have stopped the treatment were recruited. Anti-viral agents were stopped according to the recommendations of the Asian Pacific Association for the Study of the Liver. Virological relapse was defined as an increase in serum HBV DNA to >1000 copies/mL after discontinuation of treatment.

RESULTS

Eighty-four (69 treatment naïve and 15 lamivudine resistant) patients were eligible for this study. Thirty-seven patients developed virological relapse at 4.3 ± 2.9 (range 1-11) months after discontinuation of therapy. The 1-year cumulative probability of virological relapse was 42% and 47% in HBeAg (hepatitis B e antigen)-positive (n = 41) and HBeAg (hepatitis B e antigen)-negative (n = 43) patients, respectively. On multivariate analysis by Cox proportional hazard model, pre-existing lamivudine resistance, delayed suppression of HBV DNA to undetectable level during anti-viral therapy and to a higher HBsAg (hepatitis B surface antigen) level at the end of treatment were associated with virological relapse. Twelve of the 15 (80%) lamivudine resistant patients developed virological relapse. Among the 11 treatment naïve patients who had HBsAg ≤ 2 log IU/mL at the end of treatment, 1 (9%) of them had virological relapse.

CONCLUSIONS

Treatment cessation among lamivudine resistant patients is associated with high risk of virological relapse. Serum HBsAg level at the end of treatment and rate of HBV DNA suppression can provide supplementary information to guide the timing of stopping anti-viral drugs.