Fabrication and biocompatibility of an antimicrobial composite membrane with an asymmetric porous structure.

A composite slurry from silver ion-substituted nano-hydroxyapatite, titania nano-particles and polyamide 66 (Ag-nHA/TiO(2)/PA66) was prepared and used to fabricate a novel antimicrobial membrane with a gradient porous structure for guided bone regeneration (GBR). Subsequently, assays were performed to determine the cytocompatibility, as well as the bone biocompatibility of the prepared membranes. To investigate the cytocompatibility of the Ag-nHA/TiO(2)/PA66 membrane, in vitro studies were done with osteoblast-like cells (MG63) and the viability, alkaline phosphatase activity (ALP) and morphology of cells cultured on the membrane were determined.

Suppression of NADPH oxidase 2 substantially restores glucose-induced dysfunction of pancreatic NIT-1 cells.

Defects in insulin secretion by pancreatic cells and/or decreased sensitivity of target tissues to insulin action are the key features of type 2 diabetes. It has been shown that excessive generation of reactive oxygen species (ROS) is linked to glucose-induced β-cell dysfunction. However, cellular mechanisms involved in ROS generation in β-cells and the link between ROS and glucose-induced β-cell dysfunction are poorly understood.

Acupuncture on the Endometrial Morphology, the Serum Estradiol and Progesterone Levels, and the Expression of Endometrial Leukaemia-inhibitor Factor and Osteopontin in Rats.

Although it is well known that acupuncture has beneficial effects on a variety of medical conditions especially in pain relief, nausea, and vomiting, it remains controversial whether it has positive impact on the female reproduction. The present study aimed to evaluate whether the following endometrial receptivity factors: the endometrial morphology, the hormone concentrations, and the protein expression of endometrial leukaemia-inhibitory factor (LIF) and osteopontin (OPN) could be improved by the acupuncture in clomiphene citrate(CC)-induced rat model during implantation period. Results showed that, compared with the CC group, glandular development advanced, the serum estradiol levels decreased significantly, and the glandular area and endometrial LIF and OPN expression were significantly higher in acupuncture group.

Preliminary biocompatible evaluation of nano-hydroxyapatite/polyamide 66 composite porous membrane.

Nano-hydroxyapatite/polyamide 66 (nHA/PA66) composite with good bioactivity and osteoconductivity was employed to develop a novel porous membrane with asymmetric structure for guided bone regeneration (GBR). In order to test material cytotoxicity and to investigate surface-dependent responses of bone-forming cells, the morphology, proliferation, and cell cycle of bone marrow stromal cells (BMSCs) of rats cultured on the prepared membrane were determined. The polygonal and fusiform shape of BMSCs was observed by scanning electronic microscopy (SEM).

Comparison of segmentation methods for MRI measurement of cardiac function in rats.

Purpose: To establish the accuracy, intra- and inter-observer variabilities of four different segmentation methods for measuring cardiac functional parameters in healthy and infarcted rat hearts.

Materials And Methods: Six Wistar rats were imaged before and after myocardial infarction using an electrocardiogram and respiratory-gated spoiled gradient echo sequence. Blinded and randomized datasets were analyzed by various semi-automatic and manual segmentation methods to compare their measurement bias and variability.

BP1, an isoform of DLX4 homeoprotein, negatively regulates BRCA1 in sporadic breast cancer.

Introduction: Several lines of evidence point to an important role for BP1, an isoform of DLX4 homeobox gene, in breast carcinogenesis and progression. BRCA1 is a well-known player in the etiology of breast cancer. While familial breast cancer is often marked by BRCA1 mutation and subsequent loss of heterozygosity, sporadic breast cancers exhibit reduced expression of wild type BRCA1, and loss of BRCA1 expression may result in tumor development and progression.

WT-1 expression in a spectrum of melanocytic lesions: Implication for differential diagnosis.

A previous in vitro study revealed that Wilms's tumor 1 (WT-1) transcripts were detectable in 7 of 9 melanoma cell lines, but not in any of 5-normal melanocyte strains tested. Our current study assessed the expression levels of WT-1 protein in clinical samples, to determine whether the expression levels of the WT-1 protein may be used as a novel marker to assist differential diagnosis. Paraffin-embedded tissue sections from 15 cases of malignant melanomas and 25 cases of benign nevi were subjected to immunohistochemistry with a monoclonal antibody against the human WT-1 protein.

Dual use of a single Wilms' tumor 1 immunohistochemistry in evaluation of ovarian tumors: a preliminary study of 20 cases.

Our previous studies revealed that a single Wilms' tumor 1 (WT-1) immunohistochemistry can be used to elucidate both the myoepithelial cells and blood vessels of human breast tumors. As the human ovary is rich in blood vessels, and WT-1 has been used as a biomarker for ovarian tumors, our current study attempted to assess if a single WT-1 immunohistochemistry has dual usages in evaluation of ovarian tumor and endothelial cells. Paraffin-embedded tissue sections were prepared from 20 cases of ovarian tumors.

A seemingly most effective target for early detection and intervention of prostate tumor invasion.

This commentary proposes that budding tumor cell projections from focally disrupted tumor capsules represent a most effective target for early detection and intervention of prostate tumor invasion. The rationale, supporting data, and clinical applications of the hypothesis are discussed.

Tumor cell budding from focally disrupted tumor capsules: a common pathway for all breast cancer subtype derived invasion?

Human breast cancer represents a group of highly heterogeneous lesions consisting of about 20 morphologically and immnohistochemically distinct subtypes with substantially different prognoses. Our recent studies have suggested that all breast cancer subtypes, however, may share a common pathway, tumor cell budding from focally disrupted tumor capsules, for their invasion. The potential mechanisms and clinical implications of our observations are discussed.

Breast cancer heterogeneity: mechanisms, proofs, and implications.

Human breast cancer represents a group of highly heterogeneous lesions consisting of about 20 morphologically distinct subtypes with substantially different molecular and/or biochemical signatures, clinical courses, and prognoses. This study analyzed the possible correlation between the morphological presentations of breast cancer and two hypothesized models of carcinogenesis, in order to identify the intrinsic mechanism(s) and clinical implications of breast cancer heterogeneity.

BRCA1 affects global DNA methylation through regulation of DNMT1.

Global DNA hypomethylation at CpG islands coupled with local hypermethylation is a hallmark for breast cancer, yet the mechanism underlying this change remains elusive. In this study, we showed that DNMT1, which encodes a methylation maintenance enzyme, is a transcriptional target of BRCA1. BRCA1 binds to the promoter of the DNMT1 gene through a potential OCT1 site and the binding is required for maintaining a transcriptional active configuration of the promoter in both mouse and human cells.

Major pollutants in soils of abandoned agricultural land contaminated by e-waste activities in Hong Kong.

Polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyl (PCB), polybrominated diphenyl ether (PBDE) compounds and five heavy metals (cadmium, copper, chromium, lead, and zinc) were determined in soil samples collected from six sites of abandoned agricultural land affected by electronic-waste: e-waste dismantling workshop [EW (DW)], e-waste open burning site [EW (OBS)], e-waste storage [EW (S)], and agricultural (A) in the New Territories, Hong Kong. Persistent organic pollutants (POPs) and heavy metals were detected in all soil samples. EW (DW) contained the highest concentrations of PAHs, Cr, Cu, and Zn, whereas EW (OBS) had the highest concentrations of PCBs, PBDEs, Cd, and Pb.

Increased invasiveness and aggressiveness in breast epithelia with cytoplasmic p63 expression.

Our previous studies revealed that pregnancy associated breast cancer (PABC) had significantly reduced nuclear p63 expression in myoepithelia, while intense cytoplasmic p63 expression in associated epithelia. Our current study assessed these epithelia using immunohistochemistry with a panel of aggressiveness and invasiveness related markers and comparative genomic hybridization (array-CGH) with over 30,000 DNA probes. These epithelia showed several unique alterations, including (1) immunohistochemical and morphological resemblance to invasive cancer, (2) significant gain in copy numbers of DNA coding genes for morphogenesis, angiogenesis, and metastasis, and (3) significant loss in copy numbers of DNA coding genes for tumor suppressors, cell adhesion, and macromolecular complex assembly or intra-cellular trafficking.

The effects of palmitate on hepatic insulin resistance are mediated by NADPH Oxidase 3-derived reactive oxygen species through JNK and p38MAPK pathways.

Elevated plasma free fatty acid (FFA) levels in obesity may play a pathogenic role in the development of insulin resistance. However, molecular mechanisms linking FFA to insulin resistance remain poorly understood. Oxidative stress acts as a link between FFA and hepatic insulin resistance.

Alteration in protein expression in estrogen receptor alpha-negative human breast cancer tissues indicates a malignant and metastatic phenotype.

Ductal carcinoma in situ (DCIS) represents the earliest identifiable breast cancer lesion. Disruption of the myoepithelial cell layer and basement membrane is a prerequisite for DCIS to initiate invasion into the stroma. The majority of epithelial cells overlying a focally-disrupted myoepithelial cell layer are estrogen receptor-alpha negative (ER(-)); however, adjacent cells within the same duct confined by an intact myoepithelial cell layer express high levels of ER.

Preliminary evaluation of a novel strong/osteoinductive calcium phosphate cement.

We developed a novel calcium phosphate cement (CPC) by combining the silk fibroin and osteogenic supplements (β-glycerophosphate, ascorbic acid, and dexamethasone) with α-tricalcium phosphate cement. Mesenchymal stem cells (MSCs) were cultured on the novel CPC scaffold. Results showed that the novel CPC scaffold was biocompatible and favorable for the adhesion, spreading, and proliferation of MSCs.

In Vitro and In Vivo Evaluation of a nHA/PA66 Composite Membrane for Guided Bone Regeneration.

A nano-hydroxyapatite/polyamide 66 (nHA/PA66) composite with good bioactivity and osteoconductivity is employed to develop a novel porous membrane with an asymmetric structure. In order to investigate the biocompatibility and the effect on guided bone regeneration (GBR) of nHA/PA66 porous membrane, the proliferation, viability, morphology and alkaline phosphatase activity (ALP) of the osteoblast-like cell line (MG63) cultured on the membrane were studied in vitro. In vivo biocompatibility and osteogenesis of the fabricated membrane were assessed by comparing guiding rats calvarial bone defects regeneration with "gold standard" GBR material, expanded polytetrafluoroethylene (e-PTFE) membrane.

Health risk assessment of abandoned agricultural soils based on heavy metal contents in Hong Kong, the world's most populated city.

The objective of this study was to evaluate the consequence of changing and using agricultural soils to other purposes in Hong Kong with respect to risk to human health. This study established concentrations of the following priority elements: As, Cu, Cd, Cr, Pb and Zn in terms of total burden (using mixed acid microwave digestion) and with respect to metal bioaccessibility (using an in vitro simulated gastric solution). 55 locations were sampled representing 12 different land use types, namely, agricultural (A), abandoned agricultural (Ab), organic farm (OF), container storage (CS), construction waste (CW), e-waste storage (EW (S)), e-waste dismantling workshop (EW (DW)), e-waste open burning site (EW (OBS)), open burning site (OBS), petrol station (PS), metal recycling workshop (MRW) and car dismantling workshop (CDW).

Use of intermediate/small conductance calcium-activated potassium-channel activator for endothelial protection.

Objectives: Endothelial dysfunction occurs in hypoxia-related states such as ischemic heart disease or heart surgery. Intermediate- and small-conductance calcium-activated potassium channels (IKCa and SKCa) are closely related to endothelium-dependent hyperpolarizing factor-mediated endothelial function. However, the status of these KCa under hypoxia is unknown.

Cyclic tensile stretch modulates osteogenic differentiation of adipose-derived stem cells via the BMP-2 pathway.

Introduction: Mechanical forces play critical roles in the development and remodelling process of bone. As an alternative cell source for bone engineering, adipose-derived stem cells (ASCs) should be fully investigated for their responses to mechanical stress and the mechanisms responsible for osteogenic induction in response to mechanical signals.

Material And Methods: We hypothesized that appropriate application of uniaxial cyclic tensile strain to ASCs could increase bone morphogenetic protein-2 (BMP-2) expression and improve osteogenesis of ASCs.

O-fucose modulates Notch-controlled blood lineage commitment.

Notch receptors are cell surface molecules essential for cell fate determination. Notch signaling is subject to tight regulation at multiple levels, including the posttranslational modification of Notch receptors by O-linked fucosylation, a reaction that is catalyzed by protein O-fucosyltransferase-1 (Pofut1). Our previous studies identified a myeloproliferative phenotype in mice conditionally deficient in cellular fucosylation that is attributable to a loss of Notch-dependent suppression of myelopoiesis.

Aberrant leukocyte infiltration: a direct trigger for breast tumor invasion and metastasis.

Our previous studies revealed that leukocyte infiltration could trigger breast and prostate tumor invasion through physical disruption of tumor capsules. Our current study, involving multiple types of human tumors, further suggests that leukocyte infiltration also triggers metastasis through the following pathways : 1) the physical movement into the epithelium disrupts inter-cellular junctions and surface adhesion molecules, which cause the disassociation of tumor cells from tumor cores, 2) some of these tumor cells subsequently form tight junctions with the plasma membranes of leukocytes creating tumor cell-leukocyte chimeras (TLCs), and 3) the leukocytes of TLCs impart migratory capacity to associated tumor cell partners. Our findings suggest a novel pathway for tumor cell dissemination from primary sites and journey to new sites.