Detection of serum midkine levels in cancer patients using rabbit anti-human midkine monoclonal antibodies

Midkine (MK) is a heparin-binding growth factor and was found to be highly expressed in many types of human carcinomas. MK may become a novel tumor marker. In this study, we used the rabbit specific antibodies against human MK to establish a double antibody sandwich enzyme-linked immunosorbent assay (ELISA) of MK system and applied it to detect serum MK levels in different types of cancer patients. The standard curve, precision and recovery rate were tested, respectively, and serum MK concentration of 102 cancers patients and 102 normal individuals were detected using this method. The detection range of this method was 0.2 to 10 ng/ml (R2 = 0.97). The average intra and intro-assay coefficients of variation (CVs) were 3.6 and 7.9%, respectively. The average recovery rate was 89.9% when some standard antigens were added into the serum. The medians (25th and 75th percentiles) of serum MK levels were 1.35 ng/ml (0.96 and 1.64) in cancer patients and 0.30 ng/ml (0.23 and 0.38) in the controls; the MK levels of the patients were significantly higher than those of the controls (P<0.05). Moreover, 87.2% of the patients showed more than 0.6 ng/ml levels of MK. Serum MK could serve as a general tumor marker with a good potential for clinical application.Key words: Midkine, rabbit monoclonal antibody, sandwich ELISA, tumor marker

The effect of magnetic nanoparticles on the morphology, ferroelectric, and magnetoelectric behaviors of CFO/P(VDF-TrFE) 0–3 nanocomposites

Author name used in this publication: J. X. ZhangAuthor name used in this publication: J. Y. DaiAuthor name used in this publication: C. L. SunAuthor name used in this publication: C. Y. LoAuthor name used in this publication: S. W. OrAuthor name used in this publication: H. L. W. Chan2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Facile Synthesis of High Quality Graphene Nanoribbons

Graphene nanoribbons have attracted attention for their novel electronic and spin transport properties1-6, and because nanoribbons less than 10 nm wide have a band gap that can be used to make field effect transistors. However, producing nanoribbons of very high quality, or in high volumes, remains a challenge. Here, we show that pristine few-layer nanoribbons can be produced by unzipping mildly gas-phase oxidized multiwalled carbon nanotube using mechanical sonication in an organic solvent. The nanoribbons exhibit very high quality, with smooth edges (as seen by high-resolution transmission electron microscopy), low ratios of disorder to graphitic Raman bands, and the highest electrical conductance and mobility reported to date (up to 5e2/h and 1500 cm2/Vs for ribbons 10-20 nm in width). Further, at low temperature, the nanoribbons exhibit phase coherent transport and Fabry-Perot interference, suggesting minimal defects and edge roughness. The yield of nanoribbons was ~2% of the starting raw nanotube soot material, which was significantly higher than previous methods capable of producing high quality narrow nanoribbons1. The relatively high yield synthesis of pristine graphene nanoribbons will make these materials easily accessible for a wide range of fundamental and practical applications.Comment: Nature Nanotechnology in pres

HIV Types, Groups, Subtypes and Recombinant Forms: Errors in Replication, Selection Pressure and Quasispecies

HIV-1 is a chimpanzee virus which was transmitted to humans by several zoonotic events resulting in infection with HIV-1 groups M P, and in parallel transmission events from sooty mangabey monkey viruses leading to infections with HIV-2 groups A H. Both viruses have circulated in the human population for about 80 years. In the infected patient, HIV mutates, and by elimination of some of the viruses by the action of the immune system individual quasispecies are formed. Along with the selection of the fittest viruses, mutation and recombination after superinfection with HIV from different groups or subtypes have resulted in the diversity of their patterns of geographic distribution. Despite the high variability observed, some essential parts of the HIV genome are highly conserved. Viral diversity is further facilitated in some parts of the HIV genome by drug selection pressure and may also be enhanced by different genetic factors, including HLA in patients from different regions of the world. Viral and human genetic factors influence pathogenesis. Viral genetic factors are proteins such as Tat, Vif and Rev. Human genetic factors associated with a better clinical outcome are proteins such as APOBEC, langerin, tetherin and chemokine receptor 5 (CCR5) and HLA B27, B57, DRB1{*}1303, KIR and PARD3B. Copyright (C) 2012 S. Karger AG, Base

Natural variation in immune responses to neonatal mycobacterium bovis bacillus calmette-guerin (BCG) vaccination in a cohort of Gambian infants

Background There is a need for new vaccines for tuberculosis (TB) that protect against adult pulmonary disease in regions where BCG is not effective. However, BCG could remain integral to TB control programmes because neonatal BCG protects against disseminated forms of childhood TB and many new vaccines rely on BCG to prime immunity or are recombinant strains of BCG. Interferon-gamma (IFN-) is required for immunity to mycobacteria and used as a marker of immunity when new vaccines are tested. Although BCG is widely given to neonates IFN- responses to BCG in this age group are poorly described. Characterisation of IFN- responses to BCG is required for interpretation of vaccine immunogenicity study data where BCG is part of the vaccination strategy. Methodology/Principal Findings 236 healthy Gambian babies were vaccinated with M. bovis BCG at birth. IFN-, interleukin (IL)-5 and IL-13 responses to purified protein derivative (PPD), killed Mycobacterium tuberculosis (KMTB), M. tuberculosis short term culture filtrate (STCF) and M. bovis BCG antigen 85 complex (Ag85) were measured in a whole blood assay two months after vaccination. Cytokine responses varied up to 10 log-fold within this population. The majority of infants (89-98% depending on the antigen) made IFN- responses and there was significant correlation between IFN- responses to the different mycobacterial antigens (Spearman’s coefficient ranged from 0.340 to 0.675, p=10-6-10-22). IL-13 and IL-5 responses were generally low and there were more non-responders (33-75%) for these cytokines. Nonetheless, significant correlations were observed for IL-13 and IL-5 responses to different mycobacterial antigens Conclusions/Significance Cytokine responses to mycobacterial antigens in BCG-vaccinated infants are heterogeneous and there is significant inter-individual variation. Further studies in large populations of infants are required to identify the factors that determine variation in IFN- responses

Functional and molecular interactions between ERK and CHK2 in diffuse large B-cell lymphoma

Distinct oncogenic signalling cascades have been associated with non-Hodgkin lymphoma. ERK1/2 signalling elicits both transcriptional and post-transcriptional effects through phosphorylation of numerous substrates. Here we report a novel molecular relationship between ERK1/2 and CHK2, a protein kinase that is a key mediator of the DNA damage checkpoint that responds to DNA double-strand breaks. Our studies are the first to demonstrate the co-localization and overexpression of ERK1/2 and CHK2 in diffuse large B-cell lymphoma (DLBCL). The physical interaction between ERK and CHK2 was highly dependent on phosphorylated Thr 68 of CHK2. Concurrent administration of an ERK inhibitor enhances the antitumour activity of CHK2 inhibition in both a human DLBCL xenograft model as well as primary human DLBCL cells. Our data suggest a functional interaction between ERK and CHK2 and support the potential combined therapeutic targeting of ERK and CHK2 in human DLBCL

Structural analysis of MDM2 RING separates degradation from regulation of p53 transcription activity

MDM2–MDMX complexes bind the p53 tumor-suppressor protein, inhibiting p53's transcriptional activity and targeting p53 for proteasomal degradation. Inhibitors that disrupt binding between p53 and MDM2 efficiently activate a p53 response, but their use in the treatment of cancers that retain wild-type p53 may be limited by on-target toxicities due to p53 activation in normal tissue. Guided by a novel crystal structure of the MDM2–MDMX–E2(UbcH5B)–ubiquitin complex, we designed MDM2 mutants that prevent E2–ubiquitin binding without altering the RING-domain structure. These mutants lack MDM2's E3 activity but retain the ability to limit p53′s transcriptional activity and allow cell proliferation. Cells expressing these mutants respond more quickly to cellular stress than cells expressing wild-type MDM2, but basal p53 control is maintained. Targeting the MDM2 E3-ligase activity could therefore widen the therapeutic window of p53 activation in tumors

GNA11 brain somatic pathogenic variant in an individual with phacomatosis pigmentovascularis

Objective: To describe the findings of histopathology and genotyping studies in affected brain tissue from an individual with phacomatosis pigmentovascularis (PPV). / Methods: A retrospective chart review of a 2-year 10-month-old male with a clinical diagnosis of PPV cesiomarmorata (or type V) was performed. Clinical features, brain imaging and histopathology findings, and genotyping studies in his affected brain tissue are summarized. / Results: The proband had a clinically severe neurologic phenotype characterized by global developmental delay, generalized hypotonia, and recurrent episodes of cardiac asystole in the setting of status epilepticus. A somatic pathogenic variant in GNA11 (c.547C>T, p.Arg183Cys) was detected in his skin tissue but not in blood (previously published). He underwent an urgent left posterior quadrantectomy for his life-threatening seizures. Histopathology of resected brain tissue showed an increase in leptomeningeal melanocytes and abnormal vasculature, and the exact pathogenic variant in GNA11 (c.547C>T, p.Arg183Cys), previously isolated from his skin tissue but not blood, was detected in his resected brain tissue. / Conclusions: The finding of this variant in affected skin and brain tissue of our patient with PPV supports a unifying genetic diagnosis of his neurocutaneous features

Defects in muscarinic receptor-coupled signal transduction in isolated parotid gland cells after in vivo irradiation: evidence for a non-DNA target of radiation

Radiation-induced dysfunction of normal tissue, an unwanted side effect of radiotherapeutic treatment of cancer, is usually considered to be caused by impaired loss of cell renewal due to sterilisation of stem cells. This implies that the onset of normal tissue damage is usually determined by tissue turnover rate. Salivary glands are a clear exception to this rule: they have slow turnover rates (>60 days), yet develop radiation-induced dysfunction within hours to days. We showed that this could not be explained by a hypersensitivity to radiation-induced apoptosis or necrosis of the differentiated cells. In fact, salivary cells are still capable of amylase secretion shortly after irradiation while at the same time water secretion seems specifically and severely impaired. Here, we demonstrate that salivary gland cells isolated after in vivo irradiation are impaired in their ability to mobilise calcium from intracellular stores (Ca2+i), the driving force for water secretion, after exposure to muscarinic acetylcholine receptor agonists. Using radioligand-receptor-binding assays it is shown that radiation caused no changes in receptor density, receptor affinity nor in receptor-G-protein coupling. However, muscarinic acetylcholine agonist-induced activation of protein kinase C alpha (PKCα), measured as translocation to the plasma membrane, was severely affected in irradiated cells. Also, the phorbol ester PMA could no longer induce PKCα translocation in irradiated cells. Our data hence indicate that irradiation specifically interferes with PKCα association with membranes, leading to impairment of intracellular signalling. To the best of our knowledge, these data for the first time suggest that, the cells' capacity to respond to a receptor agonist is impaired after irradiation

Epidermal growth factor suppresses induction by progestin of the adhesion protein desmoplakin in T47D breast cancer cells

INTRODUCTION: Although the effects of progesterone on cell cycle progression are well known, its role in spreading and adhesion of breast cancer cells has not attracted much attention until recently. Indeed, by controlling cell adhesion proteins, progesterone may play a direct role in breast cancer invasion and metastasis. Progesterone has also been shown to modulate epidermal growth factor (EGF) effects in neoplasia, although EGF effects on progesterone pathways and targets are less well understood. In the present study we identify an effect of EGF on a progesterone target, namely desmoplakin. METHODS: Initially flow cytometry was used to establish the growing conditions and demonstrate that the T47D breast cancer cell line was responding to progesterone and EGF in a classical manner. Differential display RT-PCR was employed to identify differentially expressed genes affected by progesterone and EGF. Western and Northern blotting were used to verify interactions between EGF and progesterone in three breast cancer cell lines: T47D, MCF-7, and ZR-75. RESULTS: We found the cell adhesion protein desmoplakin to be upregulated by progesterone – a process that was suppressed by EGF. This appears to be a general but not universal effect in breast cancer cell lines. CONCLUSION: Our findings suggest that progesterone and EGF may play opposing roles in metastasis. They also suggest that desmoplakin may be a useful biomarker for mechanistic studies designed to analyze the crosstalk between EGF and progesterone dependent events. Our work may help to bridge the fields of metastasis and differentiation, and the mechanisms of steroid action