Low temperature thermocompression bonding between aligned carbon nanotubes and metallized substrate

Vertically aligned carbon nanotube (VACNT) turf is proposed for use as an electrical and thermal contact material. For these applications, one route for circumventing the high temperatures required for VACNT growth using chemical vapor deposition (CVD) is used to grow firstly VACNTs on one substrate and then transfer them to other substrates. In this work, a nano thermocompression bonding technique between VACNTs and a metallized substrate is developed to allow dry mechanical transfer of the VACNTs. Unlike the diffusion bonding between two bulk materials, nano metal clusters have a high surface energy and the atoms are very active to form alloy with the contacted bulk metal material even at much lower temperatures, so nano thermocompression bonding can decrease the bonding temperature (150 °C) and pressure (1 MPa) and greatly shorten the bonding time from hours to 20 min. A debonding experiment shows that the bonding strength between VACNTs and the metallized layer is so high that a break is less likely to occur at the bonding interface.

Expression of smoothened in mouse embryonic maxillofacial development

Hedgehog (Hh) signaling plays many key roles in the development of Drosophila and vertebrate embryos including regulation of craniofacial development. The seven-transmembrane protein, smoothened (Smo) transduces the Hh signal across the plasma membrane as an essential receptor of PTCHED1/2. There are few studies that evaluate the detailed expression of Smo in mouse embryonic craniofacial development. We investigated the expression patterns of Smo during murine embryonic craniofacial development using in situ hybridization (ISH), studies of whole-mounts and sections, immunohistochemistry, quantitative real time PCR, and Western blot analysis. We found that Smo mRNA was expressed in the face of mouse embryos at 11 and 12.5 days post coitum (dpc). After 13.5 dpc, the expression decreased to a low level and was faintly detected after birth. Smo protein could be detected also in embryos at 11, 12.5, and 14.5 dpc. After 15.5 dpc, the expression was very faint and paralleled the gene expression studies. No expression was detected in whisker follicle during facial development and faint signal was detected in Meckel's cartilage. These findings concerning Smo expression should guide further investigation of sonic Hh signaling pathway gene function during maxillofacial development.

Preparation and pharmacokinetics of ceftiofur sodium liposomes in cows

The objective of this study was to prepare ceftiofur sodium liposomes and assess their physical properties, stability, antibacterial effects, and pharmacokinetics. These liposomes appeared as a milky, light yellow suspension with encapsulation efficiency at 57.2 ± 1.17%, and there were no significant changes in all estimated indexes at 4 °C for 90 days. The minimum inhibitory concentrations of liposomes were all 1/4th that of ceftiofur sodium against Streptococcus suis, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis. Six healthy, adult cows in two treatment groups were dosed intravenously with ceftiofur sodium liposomes and ceftiofur sodium, serial blood samples collected, and plasma concentrations determined by high performance liquid chromatography. Intravenous plasma concentration profiles of liposomes best fit a two-compartment model and the elimination half-life was 2.11 times that of ceftiofur sodium. Thus, this liposome preparation provided therapeutically effective plasma concentrations for a longer duration than with the drug alone, making it more effective and convenient for use in treating bovine mastitis that requires long duration maintenance of therapeutic plasma concentrations.

Calibrating a novel multi-sensor physical activity measurement system

Advancing the field of physical activity (PA) monitoring requires the development of innovative multi-sensor measurement systems that are feasible in the free-living environment. The use of novel analytical techniques to combine and process these multiple sensor signals is equally important. This paper describes a novel multi-sensor 'integrated PA measurement system' (IMS), the lab-based methodology used to calibrate the IMS, techniques used to predict multiple variables from the sensor signals, and proposes design changes to improve the feasibility of deploying the IMS in the free-living environment. The IMS consists of hip and wrist acceleration sensors, two piezoelectric respiration sensors on the torso, and an ultraviolet radiation sensor to obtain contextual information (indoors versus outdoors) of PA. During lab-based calibration of the IMS, data were collected on participants performing a PA routine consisting of seven different ambulatory and free-living activities while wearing a portable metabolic unit (criterion measure) and the IMS. Data analyses on the first 50 adult participants are presented. These analyses were used to determine if the IMS can be used to predict the variables of interest. Finally, physical modifications for the IMS that could enhance the feasibility of free-living use are proposed and refinement of the prediction techniques is discussed.

In vitro and in vivo proliferation, differentiation and migration of cardiac endothelial progenitor cells (SCA1+/CD31+ side-population cells)

BACKGROUND

Side-population (SP) cells are a select population identified by a capacity to efflux Hoechst dye and are enriched for stem/progenitor cell activity. Previous studies suggested that cardiac SP (CSP) cells could be divided into SCA1(+)/CD31(-) and SCA1(+)/CD31(+) CSP cells. SCA1(+)/CD31(-) CSP cells have been shown to be cardiac stem/progenitor cells. However, SCA1(+)/CD31(+) CSP cells have not been fully characterized.

OBJECTIVE

The aim of the present study was to characterize SCA1(+)/CD31(+) CSP cells in the adult mouse heart, and investigate their abilities to proliferate, differentiate, vascularize and migrate in vitro and in vivo.

RESULTS

Using fluorescence-activated cell sorting (FACS), RT-PCR, and assays of cell proliferation, differentiation and migration, and a murine model of myocardial infarction (MI), we showed that SCA1(+)/CD31(+) CSP cells express stem cell and endothelial-specific genes, and reside in the blood vessels. These cells were able to proliferate, differentiate, migrate and vascularize in vitro and in vivo. After MI, SDF-1α and CXCR4 were up-regulated in the damaged myocardium and on SCA1(+)/CD31(+) CSP cells, respectively. Our results further showed that SDF-1α induced migration of these cells in vitro. Importantly, we found that SCA1(+)/CD31(+) CSP cells could migrate into the ischemic region from the non-ischemic area within the myocardium and form a vascular tube-like structure after MI.

CONCLUSIONS

Based on the gene expression profile, localization of SCA1(+)/CD31(+) CSP cells, and their ability to proliferate, differentiate, migrate and vascularize in vitro and in vivo, we postulate that SCA1(+)/CD31(+) CSP cells may represent endothelial progenitor cells in the mouse heart.

Loss of balance between T helper type 17 and regulatory T cells in chronic human immunodeficiency virus infection

The aim of this study is to characterize the changes of CD4(+) CD25(high) forkhead box P3 (FoxP3(+) ) regulatory T cells (T(reg) ), interleukin (IL)-17 secreting T helper type 17 (Th17) cell frequencies and the balance of these two subsets in a cohort of chronic human immunodeficiency virus type 1 (HIV-1)-infected patients in China. A total of 115 untreated chronic HIV-infected individuals and 32 healthy donors were recruited in this study. Peripheral blood mononuclear cells were isolated from ethylenediamine tetracetic acid (EDTA) anti-coagulated fresh whole blood and stained to characterize the frequencies of T(reg) and Th17. Of a total 115 patients, 42 individuals including 10 elite controllers were followed-up for more than 1 year, and changes of T(reg) and Th17 frequencies were analysed over time. The continuous loss of Th17 cells was accompanied by a concomitant rise in the frequency of T(reg) cells, resulting in a loss of Th17/T(reg) balance during the progressive HIV infection. Meanwhile, the T(reg) levels, Th17 levels and Th17/T(reg) ratios of the elite controller group were comparable to those of the HIV-1 negative controls in the follow-up study. Additionally, we demonstrated that loss of balance between Th17 and T(reg) is associated with an earlier CD4 T cell decline during the course of HIV infection. Our results indicate that a loss of immune-balance of Th17 to T(reg) during HIV-1 disease progression and the persistence of such an immune-balance in the elite controllers may have a critical role in HIV-1 infection and further shed new light into understanding the pathogenesis of HIV-1.

Identification and functional analysis of 9p24 amplified genes in human breast cancer

Previously, our group identified a novel amplicon at chromosome 9p24 in human esophageal and breast cancers, and cloned the novel gene, GASC1 (gene amplified in squamous cell carcinoma 1, also known as JMJD2C/KDM4C), from this amplicon. GASC1 is a histone demethylase involved in the deregulation of histone methylation in cancer cells. In the current study, we aimed to comprehensively characterize the genes in the 9p24 amplicon in human breast cancer. We performed extensive genomic analyses on a panel of cancer cell lines and narrowed the shortest region of overlap to approximately 2 Mb. Based on statistical analysis of copy number increase and overexpression, the 9p24 amplicon contains six candidate oncogenes. Among these, four genes (GASC1 UHRF2, KIAA1432 and C9orf123) are overexpressed only in the context of gene amplification while two genes (ERMP1 and IL33) are overexpressed independent of the copy number increase. We then focused our studies on the UHRF2 gene, which has a potential involvement in both DNA methylation and histone modification. Knocking down UHRF2 expression inhibited the growth of breast cancer cells specifically with 9p24 amplification. Conversely, ectopic overexpression of UHRF2 in non-tumorigenic MCF10A cells promoted cell proliferation. Furthermore, we demonstrated that UHRF2 has the ability to suppress the expression of key cell-cycle inhibitors, such as p16(INK4a), p21(Waf1/Cip1) and p27(Kip1). Taken together, our studies support the notion that the 9p24 amplicon contains multiple oncogenes that may integrate genetic and epigenetic codes and have important roles in human tumorigenesis.

PET-CT scan is a valuable modality in the diagnosis of fibrolamellar hepatocellular carcinoma: a case report and a summary of recent literature

We report a case of liver cancer with features consistent with fibrolamellar hepatocellular carcinoma (FLHCC) detected by PET-CT scan. A 20-year-old female with a large liver tumor was diagnosed with 'malignant hepatic tumor' 2 years earlier and received five courses of transhepatic arterial chemoembolization (TACE) before she presented to our hospital with abdominal distension and mild pain at the right upper quadrant. Ultrasound and CT scan showed a large tumor in the right lobe of the liver. Contrast CT scan and (18)F-FDG PET-CT showed metastatic lesions in multiple organs. The imaging diagnosis was confirmed by an ultrasound-guided fine needle biopsy of the hepatic lesion which showed features of FLHCC. Immunohistochemical staining showed a marked increase in the expressions of Hepar, CD99, MIB1, proliferating cell nuclear antigen (PCNA), Fibronectin, E-cadherin and CK7. The recent knowledge on the FLHCC and the possible applications of PET-CT were discussed.

Transgene-mediated expression of tumor necrosis factor soluble receptor attenuates morphine tolerance in rats

Opiate/narcotic analgesics are the most effective treatments for chronic severe pain, but their clinical utility is often hampered by the development of analgesic tolerance. Recent evidence suggests chronic morphine may activate glial cells to release proinflammatory cytokines. In this study, we used herpes simplex virus (HSV) vectors-based gene transfer to dorsal root ganglion to produce a local release of p55 TNF soluble receptor in the spinal cord in rats with morphine tolerance. Subcutaneous inoculation of HSV vectors expressing p55 TNF soluble receptor into the plantar surface of the hindpaws, enhanced the antinociceptive effect of acute morphine in rats. Subcutaneous inoculation of those vectors into hindpaws also delayed the development of chronic morphine tolerance in rats. TNF soluble receptor expressed by HSV vector reduced gene transcription of mRNA of spinal TNFα and IL-1β induced by repeated morphine. Furthermore, we found that TNF soluble receptor mediated by HSV, reversed the upregulation of TNFα, IL-1β and phosphorylation of p38 mitogen-activated protein kinase (MAPK) induced by repeated morphine. These results support the concept that proinflammatory cytokines may play an important role in the pathogenesis induced by morphine. This study provides a novel approach to treating morphine tolerance.

Mithramycin reduces expression of fibro-proliferative mRNAs in human gingival fibroblasts

Fibrosis is characterized by loss of normal structure and function of a tissue or organ resulting from excessive fibroblast proliferation and extracellular matrix production. Currently, there is no efficient treatment for fibrosis. Herein, we test effects of the drug mithramycin, which targets the Sp1 family of transcription factors, on mRNA expression by human gingival fibroblasts. Mithramycin reduced expression of connective tissue growth factor and type I collagen mRNAs. Microarray profiling revealed that mithramycin selectively blocked expression of cell proliferation and transforming growth factor-beta (TGF-β) signalling clusters. These microarray data were validated using real-time polymerase chain reaction and western blot analyses. Mithramycin suppressed expression of key profibrotic TGF-β signalling mediators, Smad3 and p300, as well as cell proliferation. Taken together, these data suggest that the Sp1 family of transcription factors may contribute to expression of fibrogenic genes in human gingival fibroblasts; drugs targeting the Sp1 family may be beneficial in treatment of fibro-proliferative diseases.

IKKα represses a network of inflammation and proliferation pathways and elevates c-Myc antagonists and differentiation in a dose-dependent manner in the skin

Inhibitor of nuclear factor κB kinase-α (IKKα) is required for maintaining skin homeostasis and preventing skin tumorigenesis. However, its signaling has not been extensively investigated. In the present study, we generated two mouse lines that expressed different levels of transgenic IKKα in the basal epidermis under the control of keratin-5 promoter and further evaluated their effects on the major pathways of inflammation, proliferation, and differentiation in the skin. Regardless of the transgenic IKKα levels, the mice develop normally. Because IKKα deletion in keratinocytes blocks terminal differentiation and induces epidermal hyperplasia and skin inflammation, we depleted the endogenous IKKα in these transgenic mice and found that the transgenic IKKα represses epidermal thickness and induces terminal differentiation in a dose-dependent manner. Also, transgenic IKKα was found to elevate expression of Max dimer protein 1 (Mad1) and ovo-like 1, c-Myc antagonists, but repress activities of epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK), Jun-amino-terminal kinases, c-Jun, signal transducer and activator of transcription 3 (Stat3), and growth factor levels in a dose-dependent fashion in the skin. Moreover, EGFR reduction represses IKKα deletion-induced excessive ERK, Stat3 and c-Jun activities, and skin inflammation. These new findings indicate that elevated IKKα expression not only represses epidermal thickness and induces terminal differentiation, but also suppresses skin inflammation by an integrated loop. Thus, IKKα maintains skin homeostasis through a broad range of signaling pathways.

Dual-color fluorescence cross-correlation spectroscopy on a planar optofluidic chip

Fluorescence cross-correlation spectroscopy (FCCS) is a highly sensitive fluorescence technique with distinct advantages in many bioanalytical applications involving interaction and binding of multiple components. Due to the use of multiple beams, bulk optical FCCS setups require delicate and complex alignment procedures. We demonstrate the first implementation of dual-color FCCS on a planar, integrated optofluidic chip based on liquid-core waveguides that can guide liquid and light simultaneously. In this configuration, the excitation beams are delivered in predefined locations and automatically aligned within the excitation waveguides. We implement two canonical applications of FCCS in the optofluidic lab-on-chip environment: particle colocalization and binding/dissociation dynamics. Colocalization is demonstrated in the detection and discrimination of single-color and double-color fluorescently labeled nanobeads. FCCS in combination with fluorescence resonance energy transfer (FRET) is used to detect the denaturation process of double-stranded DNA at nanomolar concentration.

Results from a low-energy analysis of the CDMS II germanium data

We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased sensitivity to interactions from weakly interacting massive particles (WIMPs) with masses below ∼10  GeV/c(2). This analysis provides stronger constraints than previous CDMS II results for WIMP masses below 9  GeV/c(2) and excludes parameter space associated with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments.