Use of nanosilver in consumer products

Silver nanoparticles (AgNP; many other names such as nanosilver and colloidal silver) have already been used in everyday consumer products requiring broad spectrum antibiotic performance because of their enormous surface area and reactivity. Faunce and Watal [1] recently have critically analyzed the international regulatory issues for medical and domestic use in USA, EU, UK, and Australia. They found that in spite of the fact numerous studies have been made in the past decades, but many scientists are still uncertain of its safety. Very recently, Powers mentioned in her dissertation that her results showed positive that Ag+ and AgNP are developmental neurotoxicants in vitro and in vivo [2]. Therefore, there is a need to conduct a study to identify a global landscape of AgNPs and their products, and their manufacturers. A market- based intellectual property (IP) study has been conducted to examine the current global patent landscape of companies using AgNP in their consumer product development and production from 1980 to 2010. Detailed information in the compositions and formulations is extracted using a "two-stage" stage-gate process from the IP activity in the use of nanosilver. The first stage is in commercial products and the second stage is in consumer products. In the first stage for AgNP and AgNP-based commercial products, there were 7,422 patent families from January 1, 1980 to December 31, 2010. In the second stage for AgNP-based consumer products, 932 patent families from January 1, 1980 to December 31, 2010 were found. Korea, China and USA were found to be the major players in AgNP and AgNP-based commercial and consumer products. However, the recent patenting downturn was observed probably due to rising price in silver metal, regulatory uncertainty, public perception, and health safety & environmental (HS&E) issues.

Crosstalk between nuclear factor I-C and transforming growth factor-β1 signaling regulates odontoblast differentiation and homeostasis

Transforming growth factor-β1 (TGF-β1) signaling plays a key role in vertebrate development, homeostasis, and disease. Nuclear factor I-C (NFI-C) has been implicated in TGF-β1 signaling, extracellular matrix gene transcription, and tooth root development. However, the functional relationship between NFI-C and TGF-β1 signaling remains uncharacterized. The purpose of this study was to identify the molecular interactions between NFI-C and TGF-β1 signaling in mouse odontoblasts. Real-time polymerase chain reaction and western analysis demonstrated that NFI-C expression levels were inversely proportional to levels of TGF-β1 signaling molecules during in vitro odontoblast differentiation. Western blot and immunofluorescence results showed that NFI-C was significantly degraded after TGF-β1 addition in odontoblasts, and the formation of the Smad3 complex was essential for NFI-C degradation. Additionally, ubiquitination assay results showed that Smurf1 and Smurf2 induced NFI-C degradation and polyubiquitination in a TGF-β1-dependent manner. Both kinase and in vitro binding assays revealed that the interaction between NFI-C and Smurf1/Smurf2 requires the activation of the mitogen-activated protein kinase pathway by TGF-β1. Moreover, degradation of NFI-C induced by TGF-β1 occurred generally in cell types other than odontoblasts in normal human breast epithelial cells. In contrast, NFI-C induced dephosphorylation of p-Smad2/3. These results show that crosstalk between NFI-C and TGF-β1 signaling regulates cell differentiation and homeostatic processes in odontoblasts, which might constitute a common cellular mechanism.

Dental follicle cells and cementoblasts induce apoptosis of ameloblast-lineage and Hertwig's epithelial root sheath/epithelial rests of Malassez cells through the Fas-Fas ligand pathway

Hertwig's epithelial root sheath (HERS), epithelial rests of Malassez (ERM) cells, and reduced ameloblasts undergo apoptosis during tooth development. This study examined the effects of dental follicle cells and cementoblasts on the apoptosis of ameloblast-lineage and HERS/ERM cells derived from the enamel organ. We also elucidated the induction pathways and identified the apoptotic pathway involved in this process. Here, we showed terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick-end labeling (TUNEL)-positive HERS cells and reduced ameloblasts near dental follicle cells during tooth development. Co-culturing ameloblast-lineage cell line (ALC) ameloblasts and HERS/ERM cells with either dental follicle cells or OCCM-30 cementoblasts markedly enhanced the apoptosis of ameloblasts and HERS/ERM cells compared with cells cultured alone. However, dental follicle cells and cementoblasts did not modulate the apoptotic responses of co-cultured non-odontogenic MCF10A or KB cells. When ameloblasts + HERS and cementoblasts + dental follicle cells were co-cultured, the expression of Fas ligand (FasL) increased in cementoblasts + dental follicle cells, while the expression of Fas increased in ameloblasts + HERS. Interestingly, recombinant FasL induced ameloblast apoptosis while the cementoblast-induced ameloblast apoptosis was suppressed by the Fas/FasL antagonist Kp7-6. These results suggest that during tooth development, dental follicle cells and cementoblasts induce apoptosis of ameloblast-lineage and HERS/ERM cells through the Fas-FasL pathway, but do not induce the apoptosis of non-odontogenic epithelial cells.

Odontogenic differentiation of human dental pulp stem cells induced by preameloblast-derived factors

The differentiation of odontoblasts is initiated by the organization of differentiating ameloblasts during tooth formation. However, the exact roles of ameloblast-derived factors in odontoblast differentiation have not yet been characterized. We investigated the effects of preameloblast-conditioned medium (PA-CM) on the odontogenic differentiation of human dental pulp stem cells (hDPSCs) in vitro and in vivo. Furthermore, we analyzed the PA-CM by liquid chromatography-mass spectrometry to identify novel factors that facilitate odontoblast differentiation. In the co-culture of MDPC-23 cells or hDPSCs with mouse apical bud cells (ABCs), ABCs promoted differentiation of odontoblastic MDPC-23 cells and facilitated odontoblast differentiation of hDPSCs. PA-CM, CM from ABCs after 3 days culture, was most effective in increasing the dentin sialophosphoprotein promoter activity of odontoblastic MDPC-23 cells. When PA-CM-treated hDPSCs were transplanted into immunocompromised mice, they generated pulp-like structures lined with human odontoblast-like cells showing typical odontoblast processes. However, during recombinant human bone morphogenenetic protein 2-treated hDPSCs transplantation, some of the cells were entrapped in mineralized matrix possessing osteocyte characteristics. After proteomic analyses, we identified 113 types of proteins in PA-CM, of which we characterized 23. The results show that preameloblast-derived factors induce the odontogenic differentiation of hDPSCs and promote dentin formation.

Vitamins and cutaneous wound healing

BACKGROUND

Vitamins have long been thought to modulate the various stages of wound healing through a variety of proposed mechanisms. Our goal was to investigate relevant studies examining the role of different vitamins in wound healing.

METHODS

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched for basic science and clinical studies examining the role of vitamins as adjuncts in wound healing.

RESULTS

Mechanisms of action for each of the vitamins are reviewed. It was suggested by many of the studies that the major vitamins A, C, E, D, K, and B have demonstrated utility as adjuncts in wound care in basic science and clinical trials.

CONCLUSION

There is a vast amount of literature on the effect of vitamins on wound healing at the basic science level. Further understanding and controlled trials will help better understand how to utilize vitamins in wound care.

DECLARATION OF INTEREST

None.

Drug eluting stents for symptomatic intracranial and vertebral artery stenosis

The use of bare metal stents (BMS) to prevent recurrent stroke due to stenosis of the cerebral vasculature is associated with high rates of restenosis. Drug-eluting stents (DES) may decrease this risk. We evaluated the performance of DES in a cohort of patients treated at our institution.Consecutive patients treated with DES were identified by a case log and billing records; data regarding procedural details, clinical outcome and angiographic follow-up was obtained by retrospective chart review.Twenty-six patients (27 vessels; 14 vertebral origin (VO); 13 intracranial) were treated. Stenosis was reduced from mean 81% to 8% at the VO and 80% to 2% intracranially. No strokes occurred in the first 24 hours after stenting or at any time point in the VO group during a mean follow-up period of nine months. Among patients with intracranial stents, stroke with permanent disability occurred within 30 days in 1/12 (8%) and after 30 days in 1/11 (9%) with clinical follow-up (mean follow-up, 14 months). Follow-up catheter angiography was obtained in 14/14 (100%) in the VO group at mean eight months and in 8/11 surviving patients (73%) at a mean of ten months after stenting in the intracranial group. The restenosis rate was 21% at the VO (3/14) and 38% (3/8) for intracranial stents. Restenosis at the VO was less frequent than might have been expected from reports utilizing BMS, however, overall restenosis rates appeared higher than previously reported for patients with intracranial DES and comparable with restenosis rates for intracranial BMS.

Myocardial infarction and the validation of physician billing and hospitalization data using electronic medical records

OBJECTIVE

Population-based identification of patients with a myocardial infarction is limited to patients presenting to hospital with an acute event. We set out to determine if adding physician billing data to hospital discharge data would result in an accurate capture of patients who have had a myocardial infarction.

METHODS

We performed a retrospective chart abstraction of 969 randomly selected adult patients using data abstracted from primary care physicians on an electronic medical record in Ontario, Canada, as the reference standard.

RESULTS

An algorithm of 3 physician billings in a one-year period with at least one being by a specialist or within a hospital or emergency room plus one hospital discharge abstract performed with a sensitivity of 80.4% (95% CI: 69.5-91.3), specificity of 98.0% (95% CI: 97.1-98.9), positive predictive value of 69.5% (95% CI: 57.7-81.2), negative predictive value of 98.9% (95% CI: 98.2% to 99.6%) and kappa statistic of 0.73 (95% CI: 0.63-0.83).

CONCLUSION

Using a combination of hospital discharge abstracts and physician billing data may be the best way of assessing trends of MI occurrence over time since it increases the capture of MI beyond those patients who have been hospitalized.

The feasibility of endoscopic submucosal dissection for rectal carcinoid tumors: comparison with endoscopic mucosal resection

BACKGROUND AND STUDY AIMS

Rectal carcinoid tumors are often found incidentally during screening colonoscopy and can be resected using various endoscopic techniques. This study aimed to compare the safety and efficacy of endoscopic submucosal dissection (ESD) with endoscopic mucosal resection (EMR) for rectal carcinoid tumors.

PATIENTS AND METHODS

Between January 2003 and June 2009, 74 patients (74 lesions) underwent either EMR (n = 28) or ESD (n = 46) for rectal carcinoid tumors. The rate of endoscopic complete resection, pathological complete resection, procedure complications, and tumor recurrence were analyzed retrospectively.

RESULTS

The endoscopic complete resection rate was significantly higher in the ESD group (46 lesions, 100 %) compared with the EMR group (25 lesions, 89.3 %) ( P = 0.049). The pathological complete resection rate was higher in the ESD group (38 lesions, 82.6 %) compared with the EMR group (18 lesions, 64.3 %); however, this difference was borderline significant ( P = 0.067). Overall complication rate was not significantly different between the EMR group (3.6 %) and the ESD group (6.3 %). There was one case of remnant lesion in the EMR group, which was managed by ESD, and no recurrence has been detected in either the EMR or ESD groups.

CONCLUSION

This study suggests that ESD might be a feasible treatment technique for small rectal carcinoid tumors. It showed superior efficacy and comparable safety to EMR.

Femoral artery complications associated with the Mynx closure device

BACKGROUND AND PURPOSE

Devices to close a femoral arteriotomy are frequently used after catheterization for interventional radiology and cardiac procedures to decrease the time to hemostasis and ambulation and, potentially, to decrease local complications. The Mynx vascular closure device uses a sealant designed to occlude the access tract, resulting in hemostasis.

MATERIALS AND METHODS

We retrospectively reviewed all cases in which the Mynx device was used and for which follow-up angiography was available. A total of 146 devices were deployed in 135 patients. A follow-up vascular study visualizing the femoral artery was performed in 26 patients (27 studies).

RESULTS

There were 5 (5/27, 18%) cases of intravascular Mynx sealant on follow-up vascular imaging. Three pseudoaneurysms (3/27, 11%) were identified.

CONCLUSIONS

In this small study, intravascular sealant and pseudoaneurysms were found frequently after femoral arterial closure with the Mynx vascular closure device.

Nuclear factor I-C is essential for odontogenic cell proliferation and odontoblast differentiation during tooth root development

Our previous studies have demonstrated that nuclear factor I-C (NFI-C) null mice developed short molar roots that contain aberrant odontoblasts and abnormal dentin formation. Based on these findings, we performed studies to elucidate the function of NFI-C in odontoblasts. Initial studies demonstrated that aberrant odontoblasts become dissociated and trapped in an osteodentin-like mineralized tissue. Abnormal odontoblasts exhibit strong bone sialoprotein expression but a decreased level of dentin sialophosphoprotein expression when compared with wild type odontoblasts. Loss of Nfic results in an increase in p-Smad2/3 expression in aberrant odontoblasts and pulp cells in the subodontoblastic layer in vivo and primary pulp cells from Nfic-deficient mice in vitro. Cell proliferation analysis of both cervical loop and ectomesenchymal cells of the Nfic-deficient mice revealed significantly decreased proliferative activity compared with wild type mice. In addition, Nfic-deficient primary pulp cells showed increased expression of p21 and p16 but decreased expression of cyclin D1 and cyclin B1, strongly suggesting cell growth arrest caused by a lack of Nfic activity. Analysis of the pulp and abnormal dentin in Nfic-deficient mice revealed an increase in apoptotic activity. Further, Nfic-deficient primary pulp cells exhibited an increase in caspase-8 and -3 activation, whereas the cleaved form of Bid was hardly detected. These results indicate that the loss of Nfic leads to the suppression of odontogenic cell proliferation and differentiation and induces apoptosis of aberrant odontoblasts during root formation, thereby contributing to the formation of short roots.

Marijuana use in potential liver transplant candidates

Concern exists that liver transplant center substance abuse policies may have an inappropriate and disproportionate impact on marijuana users. Our hypothesis is that patients with chronic liver disease who were marijuana users will have inferior survival. This is a retrospective (1999-2007) cohort study. The primary outcome measure is time-dependent, adjusted patient survival from the time of liver transplant evaluation. The primary exposure variable is a positive cannabinoid toxicology screen during the liver transplant evaluation period. Overall, 155 patients qualified as marijuana users while 1334 patients were marijuana non-users. Marijuana users were significantly (p < 0.05) younger (48.3 vs. 52.1), more likely to be male (78.1% vs. 63.0%), have hepatitis C (63.9% vs. 40.6%) and were less likely to receive a transplant (21.8% vs. 14.8%). Marijuana users were more likely to use tobacco, narcotics, benzodiazepines, amphetamines, cocaine or barbiturates (p < 0.05). Unadjusted survival rates were similar between cohorts. Upon multivariate analysis, MELD score, hepatitis C and transplantation were significantly associated with survival, while marijuana use was not (HR 1.09, 95% CI 0.78-1.54). We conclude that patients who did and did not use marijuana had similar survival rates. Current substance abuse policies do not seen to systematically expose marijuana users to additional risk of mortality.

Disruption of Nfic causes dissociation of odontoblasts by interfering with the formation of intercellular junctions and aberrant odontoblast differentiation

We reported previously that Nfic-deficient mice exhibit short and abnormal molar roots and severely deformed incisors. The objective of this study is to address the mechanisms responsible for these changes using morphological, IHC, and RT-PCR analysis. Nfic-deficient mice exhibited aberrant odontoblasts and abnormal dentin formation in molar roots and the labial crown analog of incisors. The most striking changes observed in these aberrant odontoblasts were the loss of intercellular junctions and the decreased expression of ZO-1 and occludin. As a result, they became dissociated, had a round shape, and lost their cellular polarity and arrangement as a sheet of cells. Furthermore, the dissociated odontoblasts became trapped in dentin-like mineralized tissue, resembling osteodentin in the overall morphology. These findings suggest that loss of the Nfic gene interferes with the formation of intercellular junctions that causes aberrant odontoblast differentiation and abnormal dentin formation. Collectively, these changes in odontoblasts contributed to development of molars with short and abnormal roots in Nfic-deficient mice.

[cDNA cloning and analysis of tissue-specific gene expression of rat urocortin II]

The corticotropin-releasing hormone (CRH) family of neuropeptides includes CRH (a 41 amino acid hypothalamic peptide) and urocortin. Corticotropin-releasing factor (CRF), a peptide first isolated from mammalian, plays an important role in the regulation of the pituitary-adrenal axis, and in endocrine, autonomic, immune and behavioral responses to stress. In this study we cloned rat urocortin II (UCNII) cDNA from rat mid-brain by RT-PCR. The rat UCNII clone contained an open reading frame (ORF) coding 109 amino acids which shared 90% and 63% homology with mouse and human homologues, respectively, The expression of UCN HII mRNA is mainly distributed in bone marrow, ovary, uterus, hypophysis, adrenal gland, and skin. In this study, rat recombinant UCN was expressed in E. coli and purified in active form. Furthermore, purified recombinant UCN II protein specifically binds to CRF receptor 2 in rat ROS 17/2.8 and GH3 cells by flow-cytometry analysis. UCN II cDNA clone obtained in this study will be useful for further investigation on behavioral responses to stress in rats.

Comparison of four hematology analyzers, CELL-DYN Sapphire, ADVIA 120, Coulter LH 750, and Sysmex XE-2100, in terms of clinical usefulness

We evaluated the clinical usefulness (leukocyte distribution classification, morphologic classification, and morphologic flags) of the following four hematology analyzers: CELL-DYN Sapphire (CD-Sapphire) (Abbott Diagnostics, Santa Clara, CA, USA), ADVIA 120 (Bayer Diagnostics, Tarrytown, NY, USA), Beckman Coulter LH 750 (Beckman Coulter, Miami, FL, USA), and Sysmex XE-2100 (TOA Medical Electronics Co., Kobe, Japan). Four hundred thirty samples from patients and 100 samples from healthy individuals were analyzed. For distributional classification, the sensitivity rates of CD-Sapphire, ADVIA 120, LH 750, and XE-2100 were 93.1, 95.9, 94.9, and 94.9%, respectively, and the efficiency rates were 80.7, 81.6, 84.1, and 84.2%, respectively. For morphologic classification, the sensitivity rates of CD-Sapphire, ADVIA 120, LH 750, and XE-2100 were 88.6, 93.2, 77.3, and 94.3%, respectively, and the efficiency rates were 80.9, 73.0, 79.5, and 74.2%, respectively. Comparing the findings in different morphologic flags, XE-2100 showed the highest sensitivity for Blasts flag (90.9%); CD-Sapphire showed the highest sensitivity for Immature granulocytes and/or Left-shift flag (85.5%); ADVIA 120 showed the highest sensitivity for Atypical lymphocytes flag (60.0%); and LH 750 showed the highest sensitivity for Nucleated RBC flag (75.0%). Our results demonstrate that the four analyzers are comparable in overall performance.

Loss of asymmetry in D2 receptors of putamen in unaffected family members at increased genetic risk for schizophrenia

OBJECTIVE

Dopamine dysregulation has been implicated in the pathophysiology of schizophrenia. The present study was performed to examine whether unaffected relatives at high genetic risk of schizophrenia have dopamine dysregulation in comparison with healthy controls.

METHOD

Eleven unaffected relatives from families with two or more first- or second-degree relatives with schizophrenia (n = 9) or with a monozygotic schizophrenic twin (n = 2) and 11 age- and sex-matched controls were examined using positron emission tomography (PET) with [(11)C] raclopride. Subjects also underwent extensive neuropsychological testing.

RESULTS

Subjects with high genetic risk showed a loss of asymmetry of D(2) receptors in the putamen in comparison with healthy controls. In addition, they showed significantly poorer performance on neuropsychological tests than controls.

CONCLUSION

Our results suggest that dopamine dysregulation and neuropsychological dysfunction may be present in subjects at high genetic risk of schizophrenia. However, further studies are required to confirm these findings.

A carbon nanotube gated carbon nanotube transistor with 5 ps gate delay

Semiconducting carbon nanotubes (CNTs) are attractive as channel material for field-effect transistors due to their high carrier mobility. In this paper we show that a local CNT gate can provide a significant improvement in the subthreshold slope of a CNT transistor compared to back gate switching and provide gate delays as low as 5 ps. The CNT gated CNT transistor devices are fabricated using a two-step chemical vapour deposition technique. The measured transfer characteristics are in very good agreement with theoretical modelling results that provide confirmation of the operating principle of the transistors. Gate delays below 2 ps should be readily achievable by reducing the thickness of the gate dielectric.

Evaluation of BRCA1 and BRCA2 mutations and risk-prediction models in a typical Asian country (Malaysia) with a relatively low incidence of breast cancer

INTRODUCTION

The cost of genetic testing and the limited knowledge about the BRCA1 and BRCA2 genes in different ethnic groups has limited its availability in medium- and low-resource countries, including Malaysia. In addition, the applicability of many risk-assessment tools, such as the Manchester Scoring System and BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) which were developed based on mutation rates observed primarily in Caucasian populations using data from multiplex families, and in populations where the rate of breast cancer is higher, has not been widely tested in Asia or in Asians living elsewhere. Here, we report the results of genetic testing for mutations in the BRCA1 or BRCA2 genes in a series of families with breast cancer in the multi-ethnic population (Malay, Chinese and Indian) of Malaysia.

METHOD

A total of 187 breast cancer patients with either early-onset breast cancer (at age </= 40 years) or a personal and/or family history of breast or ovarian cancer were comprehensively tested by full sequencing of both BRCA1 and BRCA2. Two algorithms to predict the presence of mutations, the Manchester Scoring System and BOADICEA, were evaluated.

RESULTS

Twenty-seven deleterious mutations were detected (14 in BRCA1 and 13 in BRCA2), only one of which was found in two unrelated individuals (BRCA2 490 delCT). In addition, 47 variants of uncertain clinical significance were identified (16 in BRCA1 and 31 in BRCA2). Notably, many mutations are novel (13 of the 30 BRCA1 mutations and 24 of the 44 BRCA2). We report that while there were an equal proportion of BRCA1 and BRCA2 mutations in the Chinese population in our study, there were significantly more BRCA2 mutations among the Malays. In addition, we show that the predictive power of the BOADICEA risk-prediction model and the Manchester Scoring System was significantly better for BRCA1 than BRCA2, but that the overall sensitivity, specificity and positive-predictive value was lower in this population than has been previously reported in Caucasian populations.

CONCLUSION

Our study underscores the need for larger collaborative studies among non-Caucasian populations to validate the role of genetic testing and the use of risk-prediction models in ensuring that the other populations in the world may also benefit from the genomics and genetics era.

[Cloning of rat TARC cDNA and analysis of tissue-specific mRNA expression]

Thymus and activation-regulated chemokine (TARC) is one that selectively controls the migration of type 2-helper T lymphocytes into inflammatory lesions. TARC is a CC chemokine, and plays an essential role in recruiting CC chemokine receptor 4-positive Th2 cells to allergic lesions. We cloned TARC cDNA from rat thymus using RT-PCR. The rat TARC clone contained a full-length open reading frame encoding 93 amino acids that showed 83% and 66% homology with mouse and human homologs, respectively. The expression of TARC mRNA was mainly in the lymphoid organs, for example, the thymus, spleen, and lymph node. The recombinant TARC was expressed in Escherichia coli and purified in an active form. In addition, the purified rat TARC with S-tagged specifically binds to human CCR4 in CD4.CCR4-transfected HOS cells by Cell-binding assay using flow-cytometry. The TARC cDNA clones obtained in this study will be valuable for future studies on allergic diseases in rats.