Long-Term, High-Spatiotemporal Resolution Recording From Cultured Organotypic Slices with High-Density Microelectrode Arrays

A novel system to cultivate and record brain slices directly on high-density microelectrode arrays (HD-MEA) was developed. This system allows to continuously record electrical activity of selected individual neurons at high spatial resolution, while monitoring neuronal network activity at the same time. For the first time, properties of single neurons and the corresponding neuronal network in an organotypic hippocampal slice culture were studied over four consecutive weeks at daily intervals.

Bone marrow-derived hematopoietic stem and progenitor cells infiltrate allogeneic and syngeneic transplants

Lineage (CD3e, CD11b, GR1, B220 and Ly-76) negative hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) infiltrate islet allografts within 24 h posttransplantation. In fact, lineage(negative) Sca-1(+) cKit(+) ("LSK") cells, a classic signature for HSCs, were also detected among these graft infiltrating cells. Lineage negative graft infiltrating cells are functionally multi-potential as determined by a standard competitive bone marrow transplant (BMT) assay. By 3 months post-BMT, both CD45.1 congenic, lineage negative HSCs/HPCs and classic "LSK" HSCs purified from islet allograft infiltrating cells, differentiate and repopulate multiple mature blood cell phenotypes in peripheral blood, lymph nodes, spleen, bone marrow and thymus of CD45.2 hosts. Interestingly, "LSK" HSCs also rapidly infiltrate syngeneic islet transplants as well as allogeneic cardiac transplants and sham surgery sites. It seems likely that an inflammatory response, not an adaptive immune response to allo-antigen, is responsible for the rapid infiltration of islet and cardiac transplants by biologically active HSCs/HPCs. The pattern of hematopoietic differentiation obtained from graft infiltrating HSCs/HPCs, cells that are recovered from inflammatory sites, as noted in the competitive BMT assay, is not precisely the same as that of intramedullary HSCs. This does not refute the obvious multi-lineage potential of graft infiltrating HSCs/HPCs.

Frequency stabilization of a 1083 nm fiber laser to ⁴He transition lines with optical heterodyne saturation spectroscopies

Two kinds of optical heterodyne saturation spectroscopies, namely, frequency modulation spectroscopy (FMS) and modulation transfer spectroscopy (MTS), are demonstrated for locking a fiber laser to the transition lines of metastable (4)He atoms around 1083 nm. The servo-loop error signals of FMS and MTS for stabilizing laser frequency are optimized by studying the dependence of the peak-to-peak amplitude and slope on the optical power of pump and probe beams. A comparison of the stabilization performances of FMS/MTS and polarization spectroscopy (PS) is presented, which shows that MTS exhibits relatively superior performance with the least laser frequency fluctuation due to its flat-background dispersive signal, originated from the four-wave mixing process. The Allan deviation of the stabilized laser frequency is 5.4 × 10(-12)@100 s with MTS for data acquired in 1000 s, which is sufficiently applicable for fields like laser cooling, optical pumping, and optical magnetometry.

A review of various techniques of mouse liver transplantation

OBJECTIVES

Liver transplantation in a mouse model is a valuable tool for studying transplantation immunobiology and clinic-relevant issues. However, the successful establishment is highly technical and demanding, impeding its widespread use. Herein, the aims of this study were to review and analyze the various techniques of liver transplantation in mice to circumvent pitfalls and minimize the incidence of complications.

MATERIALS AND METHODS

A search of PubMed was made by using the key words "mouse liver transplantation" for articles published between January 1973 and July 2012. Of the 473 publications identified, 14 were shown to be closely associated with mouse liver transplantation and 4 articles discussed specific microsurgical techniques. Through reviewing these articles, a series of potential factors were collected and analyzed in combination with other murine transplantation models, which might influence successfully establishing a mouse model for liver transplantation.

RESULTS

A mouse liver transplantation model is feasible and practical for experimental studies. Mouse strain, type of anesthesia, type of perfusion and storage solution, and reconstruction of bile duct are relevant factors but not determinants for a successful transplantation. Cold and warm ischemia time should be less than 4.0 hours and 20 minutes, respectively.

CONCLUSIONS

The cuff preparation, reconstruction of the hepatic artery, and length of the anhepatic phase play critical roles in successfully establishing a liver transplantation model in mice.

Performance of the high-resolution atmospheric model HRRR-AK for correcting geodetic observations from spaceborne radars

[1] Atmospheric phase delays are considered to be one of the main performance limitations for high-quality satellite radar techniques, especially when applied to ground deformation monitoring. Numerical weather prediction (NWP) models are widely seen as a promising tool for the mitigation of atmospheric delays as they can provide knowledge of the atmospheric conditions at the time of Synthetic Aperture Radar data acquisition. However, a thorough statistical analysis of the performance of using NWP production in radar signal correction is missing to date. This study provides a quantitative analysis of the accuracy in using operational NWP products for signal delay correction in satellite radar geodetic remote sensing. The study focuses on the temperate, subarctic, and Arctic climate regions due to a prevalence of relevant geophysical signals in these areas. In this study, the operational High Resolution Rapid Refresh over the Alaska region (HRRR-AK) model is used and evaluated. Five test sites were selected over Alaska (AK), USA, covering a wide range of climatic regimes that are commonly encountered in high-latitude regions. The performance of the HRRR-AK NWP model for correcting absolute atmospheric range delays of radar signals is assessed by comparing to radiosonde observations. The average estimation accuracy for the one-way zenith total atmospheric delay from 24 h simulations was calculated to be better than ∼14 mm. This suggests that the HRRR-AK operational products are a good data source for spaceborne geodetic radar observations atmospheric delay correction, if the geophysical signal to be observed is larger than 20 mm.

Serum high-density lipoprotein cholesterol and progression to arterial stiffness in middle-aged and elderly Chinese

BACKGROUND AND AIMS

Low high-density lipoprotein cholesterol (HDL-c) is a risk factor for cardiovascular disease. Brachial-ankle pulse wave velocity (baPWV) is an indicator of arterial stiffness, which is recognized as a predictor of cardiovascular disease. The aim of this study was to investigate the association between HDL-c and baPWV among middle-aged and elderly Chinese.

METHODS

A total number of 1133 Chinese (430 men, 703 women) aged from 50 to 90 years old were recruited from Shanghai downtown district. The baPWV and major cardiovascular risk factors of the participants were measured.

RESULTS

Serum HDL-c was negatively correlated with baPWV (r = -0.143, P < 0.001) after adjustment for age and gender. Multivariate linear regression analysis demonstrated that age (P < 0.001), systolic blood pressure (P < 0.001), HDL-c (P < 0.001), smoking (P = 0.001), BMI (P = 0.002), fasting plasma glucose (P = 0.004), and white blood cell (P = 0.005) were independently associated with baPWV. After multiple adjustments, participants in the highest quartile of HDL-c had an odds ratio of 0.442 (95% CI 0.268-0.729) for developing high arterial stiffness compared with participants in the lowest quartile. The association remained significant after further adjustment for major cardiovascular risk factors.

CONCLUSION

HDL-c has an independent protective effect on arterial stiffness in middle-aged and elderly Chinese. Early detection of HDL-c level is important in high risk populations with arterial stiffness. Increasing HDL-c level may be an attractive therapeutic target for the prevention of arterial function and subsequent disease.

A comparison of serum and sputum inflammatory mediator profiles in patients with asthma and COPD

OBJECTIVE

To investigate serum and sputum cytokine profiles in asthma and chronic obstructive pulmonary disorder (COPD).

METHODS

Clinical characteristics, blood and sputum samples were collected from asthma (n = 37) and COPD (n = 36) patients, and healthy subjects (n = 39). Cytokines were measured by enzyme-linked immunosorbent assay (ELISA) and inflammation antibody array; levels were analysed according to smoking status and presence of eosinophilia in the airways of COPD/asthma patients, and compared with those in healthy subjects.

RESULTS

ELISA revealed a significant difference in the expression of only a few cytokines in the COPD versus asthma groups, and in both patient groups compared with healthy subjects. The antibody array showed greater differentiation in inflammatory mediators. In the subphenotype analysis, the differential expression of cytokines was more significant between eosinophilic and noneosinophilic airway inflammation than between asthma and COPD, according to both the ELISA and antibody array. There was little difference in cytokine expression between smoking and nonsmoking subgroups.

CONCLUSIONS

Differential expression of inflammatory mediators is present between patients with COPD or asthma, and eosinophilic or noneosinophilic airway inflammation, and contributes to understanding the cytokine network of airway inflammation.

LXRα-mediated downregulation of FOXM1 suppresses the proliferation of hepatocellular carcinoma cells

Liver X receptors (LXRs), including LXRα and LXRβ isoforms, have important roles in the metabolic regulation of glucose, cholesterol and lipid. Moreover, activation of LXRs also represses the expression of cyclin D1 and cyclin B1, and thus suppresses the proliferation of multiple cancer cells, but the relevant mechanism is not well known. Forkhead box M1 (FOXM1) is a proliferation-specific member of forkhead box family, which is highly expressed in proliferating normal cells and numerous cancer cells. FOXM1 directly activates transcription of cyclin D1 and cyclin B1, resulting in the enhancement of cell cycle progression and cell proliferation. However, it is unclear whether LXRs are involved in the regulation of FOXM1. In this study, we demonstrated that specific LXRs agonists downregulated expression of FOXM1, cyclin D1 and cyclin B1 in hepatocellular carcinoma (HCC) cells, which led to cell cycle and cell proliferation arrest. Knockdown of FOXM1 significantly alleviated LXRs activation-mediated cell cycle arrest and cell growth suppression. Reporter assays showed that the activation of LXRs significantly reduced the transcriptional activity of FOXM1 promoter. Electrophoretic mobility shift assay and chromatin immunoprecipitation assays demonstrated that LXRα but not LXRβ could bind to an inverted repeat IR2 (-52CCGTCAcgTGACCT-39) in the promoter region of FOXM1 gene. Moreover, the xenograft tumor growth and the corresponding FOXM1 expression in nude mice were dramatically repressed by LXRs agonists. Taken together, we conclude that LXRα but not LXRβ functions as a transcriptional repressor for FOXM1 expression. The pathway 'LXRα-FOXM1-cyclin D1/cyclin B1' is a novel mechanism by which LXRs suppress the proliferation of HCC cells, suggesting that the pathway may be a novel target for HCC treatment.

Body weight difference between donor and recipient is an important affector of early graft function after renal transplantation

BACKGROUND

Poor early graft function (EGF), a frequent complication of kidney transplantation, can be caused by many risk factors, including donor kidney and body weights.

METHODS

We studied the relationship to early graft function in a rat kidney transplantation model among 3 indices: ratio of graft to body weight; ratio of native kidney to body weight, and weight difference/body weight of the recipient. We categorized 2 groups based on contralateral nephrectomy at day 1 (G1) or day 3 (G2) after transplantation. EGF was evaluated by measuring serum creatinine levels at day 1 after bilateral nephrectomy.

RESULTS

The 3 indices, ie, weight difference/body weight of recipient (G1 and G2: P < .0001), ratio of native kidney to body weight (G1: P < .0001; G2: P = .0013), and ratio of graft to body weight (G1: P = .0064; G2: P = .014) strongly correlated with EGF regardless of the time of contralateral nephrectomy.

CONCLUSIONS

The index of weight difference/body weight of recipient sensitively and predominantly influenced EGF, which probably reflects the systemic metabolic profile.

Modeling and Characterization of the Relationship between Cell Size and Mechanical Behavior of Microcellular PP/Mica Composites

The microcellular foamed polypropylene (PP)/mica composites were prepared through chemical microcellular injection to investigate the relationship between the mechanical behavior and the cell size. The mechanical behavior model of the microcellular foams is built based on the elastic stress/strain field. The mechanical behavior of the microcellular composites coincides well with the theoretical model. Under loading the large and non uniform cells are in a state of plane strain, which leads to low tensile and impact strengths, whereas small and uniform cells are in a state of plane stress, which contributes to the transition from brittle to tough fracture behavior in the microcellular PP/mica composite.

Foaming Behavior and Mechanical Properties of Microcellular PP/SiO2 Composites

Microcellular foamed polypropylene (PP)/SiO2 composites were prepared by using micro-SiO2 and nano-SiO2 particles. The effects of the particle size of SiO2 on the foaming behavior and mechanical properties of the composites were studied based on heterogeneous nucleation theory. The results showed that the silica facilitated the cell nucleation to some extent. The average cell size of 16.3 μm and the cell density of 4.46 × 107 cells/cm3 were achieved for the composite foam at the silica content of 4 wt.%. The plastic deformation of the PP was strongly constrained due to the presence of the nano-silica. The tensile and impact strength of the nano-SiO2 composite foam are larger than those of the micro-SiO2 composite foam due to the high crack propagation resistance in the microcellular PP/nano-SiO2 composite.

Superselective uterine arterial embolization combined with transcatheter intra-arterial methotrexate infusion in 40 cases with fallopian tube ectopic pregnancy

PURPOSE

To evaluate the therapeutic results of superselective uterine artery infusion and embolization in 40 patients with fallopian tube ectopic pregnancy, and to explore the role of this minimally invasive treatment as an alternative to surgery.

MATERIALS AND METHODS

Superselective catheterization of uterine artery through cannulation of femoral artery was achieved in 40 patients with fallopian tube ectopic pregnancy (EP). Location of the lesions involved feeding arteries and active bleeding were observed through angiography. Methotrexate (MTX) diluted in saline water was slowly infused into the target artery. Small gelatin spongy particles were used to embolize the uterine artery until its branches were totally obliterated. Follow-up was undertaken to observe the results of the treatment.

RESULTS

Superselective uterine arterial infusion and embolization were successfully performed in all 40 patients without any related complications. Active bleeding in the peritoneum in 33 cases ceased soon after embolization. The embryos in 13 patients were confirmed to have died by ultrasound three days after the procedure. Beta-human chorionic gonadotropin ((beta-hCG) value dropped to below 15 IU/L at three to 21 days. Hemorrhage in the peritoneum dissolved after seven days in all cases. Mixed mass disappeared after one month. Hysterosalpingography was performed three months after the procedure in 19 patients and patent fallopians were demonstrated in 16 patients.

CONCLUSIONS

Superselective uterine arterial infusion and emboliztion is a minimally invasive procedure, which can be used to effectively treat EP by disabling the ectopic embryo and leaking arteries with the advantages of preserving the fallopian tubes.

Preliminary experience of endoscopic submucosal tunnel dissection for upper gastrointestinal submucosal tumors

BACKGROUND AND STUDY AIM

Although the majority of submucosal tumors (SMTs) are benign, some do have a malignant potential. Resection of SMTs would aid in establishing the diagnosis and may be curative. Our aim was to examine the feasibility and safety of a novel method for endoscopic resection of upper gastrointestinal SMTs.

PATIENTS AND METHODS

In 12 patients who presented with an upper gastrointestinal SMT of ≤40 mm located in the esophagus or cardia, a submucosal tunnel was endoscopically created starting approximately 5 cm proximal to the lesion. After careful submucosal dissection with carbon dioxide or air insufflation, the SMTs were completely removed, and the entrance of the tunnel closed using endoclips.

RESULTS

SMTs had a mean size of 19.5 mm (range 10-40 mm); eight were located in the esophagus and four in the cardia. SMT resection was successful in all patients with en bloc resection in 10 patients (83.3%) and resection in two pieces in the remaining two patients. The mean time required for the procedure was 48.3 minutes (range 30-60 minutes). Two patients had both pneumothorax and subcutaneous emphysema. All the complications resolved with conservative management.

CONCLUSIONS

In this pilot study, endoscopic submucosal tunnel dissection (ESTD) of esophageal and cardia SMTs was effective and appeared to be safe. Larger studies that also examine its application for gastric SMTs are warranted.

Metabolic effects of bariatric surgery in type 2 diabetic patients with body mass index < 35 kg/m2

AIM

The aim of this meta-analysis is to assess the metabolic effects of bariatric surgery in type 2 diabetes mellitus (T2DM) patients with body mass index (BMI) < 35 kg/m(2) .

METHODS

We performed an electronic literature search of published articles to identify relevant evidence since inception to June 2011. Primary outcome measures were metabolic improvement and resolution diabetes after bariatric surgery. The weighted mean difference (WMD) and its 95% confidence interval (CI) were calculated from the raw data extracted from the original literature. The software Review Manager (version 4.3.1) was applied for meta-analysis.

RESULTS

Thirteen trials involving 357 patients were included in the meta-analysis. The follow-up interval ranged from 6 months to 18 years. According to WMD calculation, bariatric surgery led to 5.18 kg/m(2) of BMI lowering (95% CI, 3.79-6.57, p < 0.00001), 4.8 mmol/l of fasting plasma glucose (FPG) decrement (95% CI, 3.88-5.71 mmol/l, p < 0.00001), 2.59% of HbA1c decreasing (95% CI, 2.12-3.07%, p < 0.00001), 56.67 mg/dl of triglyceride decrement (95% CI 11.53-101.82, p = 0.01) and 48.38 mg/dl of total cholesterol reduction (95% CI 21.08-75.68, p = 0.0005). Moreover, the procedures produced an increased high-density lipoprotein cholesterol by 5.37 mg/dl (95% CI -11.37-0.63, p = 0.08). However, this effect was not statistically significant. Overall, 80.0% of the patients achieved adequate glycaemic control (HbA1c < 7%) without antidiabetic medication. The surgeries produced a low incidence of major complications (3.2%) with no mortality.

CONCLUSIONS

Bariatric surgery is effectual and safe in the treatment of non-severely obese (BMI < 35 kg/m(2) ) T2DM patients. Moreover, the metabolic benefits acquired from the procedures can be long sustained after the surgery.

Metabolic effects of bariatric surgery in type 2 diabetic patients with body mass index < 35 kg/m2

AIM

The aim of this meta-analysis is to assess the metabolic effects of bariatric surgery in type 2 diabetes mellitus (T2DM) patients with body mass index (BMI) < 35 kg/m(2) .

METHODS

We performed an electronic literature search of published articles to identify relevant evidence since inception to June 2011. Primary outcome measures were metabolic improvement and resolution diabetes after bariatric surgery. The weighted mean difference (WMD) and its 95% confidence interval (CI) were calculated from the raw data extracted from the original literature. The software Review Manager (version 4.3.1) was applied for meta-analysis.

RESULTS

Thirteen trials involving 357 patients were included in the meta-analysis. The follow-up interval ranged from 6 months to 18 years. According to WMD calculation, bariatric surgery led to 5.18 kg/m(2) of BMI lowering (95% CI, 3.79-6.57, p < 0.00001), 4.8 mmol/l of fasting plasma glucose (FPG) decrement (95% CI, 3.88-5.71 mmol/l, p < 0.00001), 2.59% of HbA1c decreasing (95% CI, 2.12-3.07%, p < 0.00001), 56.67 mg/dl of triglyceride decrement (95% CI 11.53-101.82, p = 0.01) and 48.38 mg/dl of total cholesterol reduction (95% CI 21.08-75.68, p = 0.0005). Moreover, the procedures produced an increased high-density lipoprotein cholesterol by 5.37 mg/dl (95% CI -11.37-0.63, p = 0.08). However, this effect was not statistically significant. Overall, 80.0% of the patients achieved adequate glycaemic control (HbA1c < 7%) without antidiabetic medication. The surgeries produced a low incidence of major complications (3.2%) with no mortality.

CONCLUSIONS

Bariatric surgery is effectual and safe in the treatment of non-severely obese (BMI < 35 kg/m(2) ) T2DM patients. Moreover, the metabolic benefits acquired from the procedures can be long sustained after the surgery.

Ex vivo expansion of natural killer cells with high cytotoxicity by K562 cells modified to co-express major histocompatibility complex class I chain-related protein A, 4-1BB ligand, and interleukin-15

A large number of natural killer (NK) cells with high function are expected to generate especially in tumor adoptive immunotherapy. Here K562 cells were genetically modified to co-express major histocompatibility complex class I chain-related protein A (MICA), 4-1BB ligand, and IL-15, called K562-MICA-4-1BBL-IL-15. The modified K562 cells not only promoted activation, proliferation, and survival of NK cells, but also enhanced NK cell cytotoxicity. In long-term culture tests, K562-MICA-4-1BBL-IL-15 cells stimulated NK cell to expand mean 550 folds in 24-day culture and to cover from 14.8% of total peripheral blood monoclonal lymphocytes on day 1 to 86.7% on day 24. Prevalent NK cells after expansion enhanced the ability of killing targets and producing interferon gamma (IFN-γ), and kept high expression of activating receptors. The results indicated that K562-MICA-4-1BBL-IL-15 cells would be developed for expansion of NK cells ex vivo and may have important implications for clinical immunotherapy.