Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry.

Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291.

Assessment of CXC ligand 12-mediated calcium signalling and its regulators in basal-like breast cancer cells.

CXC ligand (L)12 is a chemokine implicated in the migration, invasion and metastasis of cancer cells via interaction with its receptors CXC chemokine receptor (CXCR)4 and CXCR7. In the present study, CXCL12-mediated Ca2+ signalling was compared with two basal-like breast cancer cell lines, MDA-MB-231 and MDA-MB-468, which demonstrate distinct metastatic potential. CXCL12 treatment induced Ca2+ responses in the more metastatic MDA-MB-231 cells but not in the less metastatic MDA-MB-468 cells. Assessment of mRNA levels of CXCL12 receptors and their potential modulators in both cell lines revealed that CXCR4 and CXCR7 levels were increased in MDA-MB-231 cells compared with MDA-MB-468 cells. Cluster of differentiation (CD)24, the negative regulator of CXCL12 responses, demonstrated increased expression in MDA-MB-468 cells compared with MDA-MB-231 cells, and the two cell lines expressed comparable levels of hypoxia-inducible factor (HIF)2α, a CXCR4 regulator. Induction of epithelial-mesenchymal transition (EMT) by epidermal growth factor exhibited opposite effects on CXCR4 mRNA levels compared with hypoxia-induced EMT. Neither EMT inducer exhibited an effect on CXCR7 expression, however hypoxia increased HIF2α expression levels in MDA-MB-468 cells. Analysis of the gene expression profiles of breast tumours revealed that the highest expression levels of CXCR4 and CXCR7 were in the Claudin-Low molecular subtype, which is markedly associated with EMT features.

Oncosis and apoptosis induction by activation of an overexpressed ion channel in breast cancer cells.

The critical role of calcium signalling in processes related to cancer cell proliferation and invasion has seen a focus on pharmacological inhibition of overexpressed ion channels in specific cancer subtypes as a potential therapeutic approach. However, despite the critical role of calcium in cell death pathways, pharmacological activation of overexpressed ion channels has not been extensively evaluated in breast cancer. Here we define the overexpression of transient receptor potential vanilloid 4 (TRPV4) in a subgroup of breast cancers of the basal molecular subtype. We also report that pharmacological activation of TRPV4 with GSK1016790A reduced viability of two basal breast cancer cell lines with pronounced endogenous overexpression of TRPV4, MDA-MB-468 and HCC1569. Pharmacological activation of TRPV4 produced pronounced cell death through two mechanisms: apoptosis and oncosis in MDA-MB-468 cells. Apoptosis was associated with PARP-1 cleavage and oncosis was associated with a rapid decline in intracellular ATP levels, which was a consequence of, rather than the cause of, the intracellular ion increase. TRPV4 activation also resulted in reduced tumour growth in vivo. These studies define a novel therapeutic strategy for breast cancers that overexpress specific calcium permeable plasmalemmal ion channels with available selective pharmacological activators.

Reinforcement in removable prosthodontics: a literature review.

Removable prosthodontics are often associated with mechanical troubles in daily use, such as fracture or deformation. These troubles render prostheses unusable and reduce wearers' QOL. Various reinforcements are used to prevent such problems, but consensus on reinforcement has not been reached. This review aimed to summarise the effects of reinforcement and to propose favourable reinforcement based on material, design and position in the prostheses. Initially, 139 articles were selected by electronic and manual searches. After exclusion of 99 articles based on the exclusion criteria, 40 articles were finally included in the review. Electronic searches were performed for articles published from 2005 to 2015 in PubMed, EMBASE, MEDLINE and Cochrane Library, and manual searches were performed in 10 journals relevant to the topic of removable prosthodontics. For in vitro studies, certain dental alloys and fibres were mainly used. Their forms were different, including complicated forms in dental alloys and various forms in fibres. The materials were examined for mechanical properties like fracture strength, flexural strength and elastic modulus and compared with one another or without reinforcement. There were a few clinical studies and one longitudinal study. Cast metal reinforcement seemed to be most favourable in terms of fracture toughness and stiffness. The most favourable forms differed depending on the prostheses, but placement around thin and deformable areas was effective. However, randomised or longitudinal clinical reports and comparative clinical studies on the use of reinforcement were still lacking and such studies are necessary in the future.

The MYB proto-oncogene suppresses monocytic differentiation of acute myeloid leukemia cells via transcriptional activation of its target gene GFI1.

The MYB gene is a master regulator of hematopoiesis and contributes to leukemogenesis in several species including humans. Although it is clear that MYB can promote proliferation, suppress apoptosis and block differentiation, the identities of the MYB target genes that mediate these effects have only been partially elucidated. Several studies, including our own, have collectively identified substantial numbers of MYB target genes, including candidates for each of these activities; however, functional validation, particularly in the case of differentiation suppression, has lagged well behind. Here we show that GFI1, which encodes an important regulator of hematopoietic stem cell (HSC) function and granulocytic differentiation, is a direct target of MYB in myeloid leukemia cells. Chromatin immunoprecipitation and reporter studies identified a functional MYB-binding site in the promoter region of GFI, whereas ectopic expression and small hairpin RNA-mediated knockdown of MYB resulted in concomitant increases and decreases, respectively, in GFI1 expression. We also demonstrate that GFI1, like MYB, can block the induced monocytic differentiation of a human acute myeloid leukemia cell line, and most importantly, that GFI1 is essential for MYB's ability to block monocytic differentiation. Thus, we have identified a target of MYB that is a likely mediator of its myeloid differentiation-blocking activity, and which may also be involved in MYB's activities in regulating normal HSC function and myeloid differentiation.

Five-year multicenter study of magnetic attachments used for natural overdenture abutments.

The purpose of this study was to examine a longitudinal clinical performance of magnetic attachments used for natural overdenture abutments. The study included 131 patients who had used removable prostheses (complete overdentures 31%, partial dentures 69%) more than 5 years (40-90 years old) with 211 magnetic attachments on natural abutments (Magfit 400 or 600; Aichi Steel co., Aichi, Japan) treated in 15 clinics using a standardized protocol. Analyses were performed on the degree of patient satisfaction regarding retention, complications of magnets (corrosion, detachment from denture base), abutments (pain during mastication, periodontal pocket formation, inflammation, mobility), and dentures (fracture etc.). Ninety-seven percent of patients were satisfied with the retention and stability of their dentures. No corrosion of magnet was observed, and 19 magnets were detached. Most frequent complication of abutments was periodontal pocket formation (52%), followed by the inflammation (29%), increase in mobility (27%) and pain (4%). Magnetic attachment on natural tooth abutments provided a viable and long-term treatment option.

Role and potential for therapeutic targeting of MYB in leukemia.

The Myb protein was first identified as an oncogene that causes leukemia in chickens. Since then, it has been widely associated with different types of cancers and studied in detail in myeloid leukemias. However, despite these studies, its role in the induction, pathogenesis and maintenance of AML, and other blood disorders, is still not well understood. Recent efforts to uncover its plethora of transcriptional targets have provided key insights into understanding its mechanism of action. This review evaluates our current knowledge of the role of Myb in leukemia, with a particular focus on AML, from the vast literature spanning three decades, highlighting key studies that have influenced our understanding. We discuss recent insights into its role in leukemogenesis and how these could be exploited for the therapeutic targeting of Myb, its associated co-regulators or its target genes, in order to improve outcomes in the treatment of a wide range of hematopoietic malignancies.

PG545, a dual heparanase and angiogenesis inhibitor, induces potent anti-tumour and anti-metastatic efficacy in preclinical models.

BACKGROUND: PG545 is a heparan sulfate (HS) mimetic that inhibits tumour angiogenesis by sequestering angiogenic growth factors in the extracellular matrix (ECM), thus limiting subsequent binding to receptors. Importantly, PG545 also inhibits heparanase, the only endoglycosidase which cleaves HS chains in the ECM. The aim of the study was to assess PG545 in various solid tumour and metastasis models. METHODS: The anti-angiogenic, anti-tumour and anti-metastatic properties of PG545 were assessed using in vivo angiogenesis, solid tumour and metastasis models. Pharmacokinetic (PK) data were also generated in tumour-bearing mice to gain an understanding of optimal dosing schedules and regimens. RESULTS: PG545 was shown to inhibit angiogenesis in vivo and induce anti-tumour or anti-metastatic effects in murine models of breast, prostate, liver, lung, colon, head and neck cancers and melanoma. Enhanced anti-tumour activity was also noted when used in combination with sorafenib in a liver cancer model. PK data revealed that the half-life of PG545 was relatively long, with pharmacologically relevant concentrations of radiolabeled PG545 observed in liver tumours. CONCLUSION: PG545 is a new anti-angiogenic clinical candidate for cancer therapy. The anti-metastatic property of PG545, likely due to the inhibition of heparanase, may prove to be a critical attribute as the compound enters phase I clinical trials.

A functional SUMO-interacting motif in the transactivation domain of c-Myb regulates its myeloid transforming ability.

c-Myb is an essential hematopoietic transcription factor that controls proliferation and differentiation of progenitors during blood cell development. Whereas sumoylation of the C-terminal regulatory domain (CRD) is known to have a major impact on the activity of c-Myb, no role for noncovalent binding of small ubiquitin-like modifier (SUMO) to c-Myb has been described. Based on the consensus SUMO-interacting motif (SIM), we identified and examined putative SIMs in human c-Myb. Interaction and reporter assays showed that the SIM in the in the transactivation domain of c-Myb (V(267)NIV) is functional. This motif is necessary for c-Myb to be able to interact noncovalently with SUMO, preferentially SUMO2/3. Destroying the SUMO-binding properties by mutation resulted in a large increase in the transactivation potential of c-Myb. Mutational analysis and overexpression of conjugation-defective SUMO argued against intramolecular repression caused by sumoylated CRD and in favor of SUMO-dependent repression in trans. Using both a myeloid cell line-based assay and a primary hematopoietic cell assay, we addressed the transforming abilities of SUMO binding and conjugation mutants. Interestingly, only loss of SUMO binding, and not SUMO conjugation, enhanced the myeloid transformational potential of c-Myb. c-Myb with the SIM mutated conferred a higher proliferative ability than the wild-type and caused an effective differentiation block. This establishes SUMO binding as a mechanism involved in modulating the transactivation activity of c-Myb, and responsible for keeping the transforming potential of the oncoprotein in check.

The PG500 series: novel heparan sulfate mimetics as potent angiogenesis and heparanase inhibitors for cancer therapy.

Heparan sulfate mimetics, which we have called the PG500 series, have been developed to target the inhibition of both angiogenesis and heparanase activity. This series extends the technology underpinning PI-88, a mixture of highly sulfated oligosaccharides which reached Phase III clinical development for hepatocellular carcinoma. Advances in the chemistry of the PG500 series provide numerous advantages over PI-88. These new compounds are fully sulfated, single entity oligosaccharides attached to a lipophilic moiety, which have been optimized for drug development. The rational design of these compounds has led to vast improvements in potency compared to PI-88, based on in vitro angiogenesis assays and in vivo tumor models. Based on these and other data, PG545 has been selected as the lead clinical candidate for oncology and is currently undergoing formal preclinical development as a novel treatment for advanced cancer.

Intestinal adenoma formation and MYC activation are regulated by cooperation between MYB and Wnt signaling.

Aberrant Wnt signaling mediated by mutations affecting APC (adenomatous polyposis coli) or beta-catenin initiates the majority of human colorectal cancers (CRC) and drives tumorigenesis through the activation of specific genes such as MYC. We report here a novel association whereby another oncogenic transcription factor, MYB/c-Myb, is necessary for intestinal adenoma development directed by activated Wnt signaling. APC(Min/+) mice in which c-myb is haploinsufficient survive longer than wild-type APC(Min/+) animals due to a delay in adenoma formation. Intestinal adenomas from APC(Min/+) mice were assessed and found to have high levels of c-myc gene expression. We explored the relationship between activated Wnt signaling and MYB in regulating MYC and found activated beta-catenin in combination with MYB induces robust upregulation of MYC promoter activity, as well as endogenous MYC mRNA and protein expression, in human cells. This cooperation occurred through independent binding of MYB and beta-catenin to the MYC promoter. These data highlight a cooperative function for MYB in the context of activated Wnt signaling and provide a molecular basis for the expression of MYC in CRC.

Development of an RPD CAD system with finite element stress analysis.

The structural design of removable partial dentures (RPDs) is critical for preventing distortion of the prosthesis, protecting abutment teeth and residual ridges as well as for high masticatory performance. The aim of this study was to clarify the feasibility and utility of a computer-aided designing (CAD) system with finite element analysis (FEA) for molar teeth arrangement in unilateral distal extension base RPDs. The shapes of artificial teeth and residual ridge were measured and converted into point group data. Solid models were created from surface-modelled point group data in a 3D surface CAD format. An occlusal rim was created on the residual ridge mucosa and the occlusal rim - residual ridge mucosa model with FEA function was created. Stress distribution on the residual ridge mucosa was compared by changing the loading point. The artificial teeth were then arranged in locations with the lowest amount of stress. After building an artificial teeth - saddle - residual ridge mucosa model, stress distribution in the residual ridge mucosa was re-evaluated by simulating occlusal force. On the occlusal rim - residual ridge mucosa model, stress was reduced when the loading point was located around the buccal shelf where functional cusps of artificial teeth were charted. It was confirmed that stress distribution in the residual ridge mucosa was equalized on the artificial teeth - saddle - residual ridge mucosa model. This system might be clinically useful tool for designing RPDs if FEA-guided designing of retainers and connectors can be added.

Repression of Gadd45alpha by activated FLT3 and GM-CSF receptor mutants contributes to growth, survival and blocked differentiation.

The tumor suppressor Gadd45alpha was earlier shown to be a repressed target of sustained receptor-mediated ERK1/2 signaling. We have identified Gadd45alpha as a downregulated gene in response to constitutive signaling from two FLT3 mutants (FLT3-ITD and FLT3-TKD) commonly found in AML, and a leukemogenic GM-CSF receptor trans-membrane mutant (GMR-V449E). GADD45A mRNA downregulation is also associated with FLT3-ITD(+) AML. Sustained ERK1/2 signaling contributes significantly to receptor-mediated downregulation of Gadd45alpha mRNA in FDB1 cells expressing activated receptor mutants, and in the FLT3-ITD(+) cell line MV4;11. Knockdown of Gadd45alpha with shRNA led to increased growth and survival of FDB1 cells and enforced expression of Gadd45alpha in FDB1 cells expressing FLT3-ITD or GMR-V449E resulted in reduced growth and viability. Gadd45alpha overexpression in FLT3-ITD(+) AML cell lines also resulted in reduced growth associated with increased apoptosis and G(1)/S cell cycle arrest. Overexpression of Gadd45alpha in FDB1 cells expressing GMR-V449E was sufficient to induce changes associated with myeloid differentiation suggesting Gadd45alpha downregulation contributes to the maintenance of receptor-induced myeloid differentiation block. Thus, we show that ERK1/2-mediated downregulation of Gadd45alpha by sustained receptor signaling contributes to growth, survival and arrested differentiation in AML.

Association of symptomless TMJ sounds with occlusal force and masticatory performance in older adults.

This study investigated associations between temporomandibular joint (TMJ) sounds and occlusal force or masticatory performance stratified by posterior occlusal supports in older Japanese adults. The subjects consisted of 1646 independently living people over 60 years. Masticatory performance, occlusal force, TMJ sounds and maximal mouth opening were examined. Posterior occlusal supports were classified by the Eichner Index. The prevalence of TMJ sounds was 27.7%, limitation of mouth opening (< 40 mm) was 7.9% and TMJ pain was only 1.5%. In the Eichner C group, TMJ sounds were significantly associated with lower occlusal force (OR = 3.20, P = 0.046) and lower masticatory performance (OR = 3.18, P = 0.041) after controlling for gender and age. These associations were not found in the Eichner A and B groups. Within the limitations of this study, the presence of TMJ sounds, even if they were symptomless, was associated with impairment of masticatory function in older adults with reduced occlusal support.

Effect of reinforcement on overdenture strain.

Because the abutment becomes the fulcrum, and the denture base over the coping is usually thin, the overdenture is susceptible to fracture. We hypothesized that rational reinforcement can reduce strain and prevent deformation and fracture of the overdenture. We investigated the effect of reinforcement on overdenture strain around the copings and at a midline. A mandibular edentulous model with a 2-mm-thick artificial mucosa and abutment teeth installed bilaterally in the canine position was produced. The coping had a dome-shaped upper surface with a height of 6 mm. On the lingual polished surface, strain gauges were attached at the canine position and at the midline. A vertical load of 49 N was applied on the occlusal surface. Among several kinds of reinforcements, the cast metal reinforcement that covers both the midline and the coping top significantly reduced the strain on the overdenture. It is suggested that this simple reinforcement is effective in preventing deformation and fracture of the overdenture.

Influence of abutment height on strain in a mandibular overdenture.

The purpose of this study was to investigate the influence of coping heights on the strain around the abutment teeth and at the middle part of mandibular overdentures, using strain gauges. A mandibular edentulous model with a silicone artificial mucosa of thickness 2 mm was made. Two artificial roots were embedded on both sides in the canine position. The coping had a dome-shaped upper surface at a height of 0, 2, 4 and 6 mm. On the lingual polished surface of the overdenture, three strain gauges were attached in the left canine position at the vertical level corresponding to the top of the 6, 4 and 2 mm copings and two strain gauges were attached in the middle section (upper and lower). A vertical loading of 49 N was applied on the occlusal surface of first premolar, first molar and second molar. When loading on the first premolar adjacent to an abutment, the largest tensile strain was observed on the overdenture surface close to the top of each coping, independent of coping heights. When loading on the first premolar on the opposite side, the tensile strains around the coping were remarkably smaller. In the middle part of the overdenture, the compressive strains became larger by reducing the coping height or loading on distal point. The largest tensile strain was observed on the overdenture surface close to the top of copings, independent of coping heights.

Effect of magnetic attachment with stress breaker on lateral stress to abutment tooth under overdenture.

Recently, a newly developed magnetic attachment with stress breaker was used in retentive components in overdentures. Excessive lateral stress has a more harmful effect on natural teeth than axial stress, and the magnetic attachment with stress breaker is expected to reduce lateral forces on abutment teeth and protect it teeth from excessive stress. However, the properties of this retainer have not yet been determined experimentally. This study compares the lateral forces on abutment teeth for three retainers under loading on the denture base in a model study. A mandibular simulation model is constructed to measure lateral stress. Three types of retentive devices are attached to the canine root. These devices include the conventional root coping, the conventional magnetic attachment and the new magnetic attachment with stress breaker. For each retentive device, load is generated on the occlusal table of the model overdenture, and the lateral stress on the canine root and the displacement of the overdenture measured. The magnetic attachment with stress breaker does not displace the denture and exhibits lower lateral stress in the canine root than conventional root coping and magnetic attachments.

The Wilms' tumour suppressor protein, WT1, undergoes CRM1-independent nucleocytoplasmic shuttling.

The Wilms' tumour suppressor gene (WT1) encodes a zinc finger-containing nuclear protein essential for kidney and urogenital development. Initially considered a transcription factor, there is mounting evidence that WT1 has a role in post-transcriptional processing. Using the interspecies heterokaryon assay, we have demonstrated that WT1 can undergo nucleocytoplasmic shuttling. We have also mapped the region responsible for nuclear export to residues 182-324. Our data add further complexity to the role of WT1 in transcriptional and post-transcriptional regulation.

Functional expression cloning reveals proapoptotic role for protein phosphatase 4.

Functional expression cloning strategies are highly suitable for the analysis of the molecular control of apoptosis. This approach has two critical advantages. Firstly, it eliminates prior assumptions about the properties of the proteins involved, and, secondly, it selectively targets proteins that are causally involved in apoptosis control and which affect the crucial cellular decision between survival and death. The application of this strategy to the isolation of cDNAs conferring resistance to dexamethasone and gamma-irradiation resulted in the isolation of a partial cDNA for the catalytic subunit of protein phosphatase 4 (PP4). Cells transfected with this partial cDNA in an expression vector downregulated PP4 and were resistant to both dexamethasone and UV radiation, as demonstrated by both membrane integrity and colony-forming assays. These observations suggest that PP4 plays an important proapoptotic role in T lymphocytes.