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Dementia prevention is highly important. Improved control of vascular risk factors has the potential to decrease dementia risk, but may be difficult. Therefore, we developed and piloted a care management protocol for Veterans at risk for dementia. We enrolled 32 Veterans with diabetes and hypertension, at least one of which was poorly controlled, and cognitive impairment. Participants were randomly assigned to a 6-month care management intervention or to usual care. At enrollment, 6-months and 12-months, we assessed cognitive performance, mood, and diabetes and hypertension control. At follow-up, diastolic blood pressure was lower in intervention participants at 6 months (p=.041) and 12 months (p=.022); hemoglobin A1c, global mental status and mood did not differ between groups. Recall of a distractor list (p=.006) and logical memory long-delay recall (p=.036) were better at 6 months in the intervention group (p=.006). Care management may contribute to improved control of dementia risk factors.

We examined novice teachers’ beliefs about grading and constructivist teaching approaches. Adapting an existing instrument designed to assess preservice teachers’ grading beliefs that deviate from recommended practices, we administered the Survey of Grading Beliefs to 203 inservice teachers. Exploratory factor analysis resulted in a 3-factor model with a structure similar to that found in prior research; differences between the 2 samples were noted. Teachers who endorsed grading beliefs characterized as “academic enabling” tended to endorse constructivist teaching approaches. To better understand the underlying reasoning of the academic enabling factor, we conducted qualitative research with 6 additional teachers. Results revealed that teachers’ reasons for grading judgments were strategic, analytical, and thoughtful, not haphazard. This study provides empirical evidence about the nature of novice teachers’ beliefs about grading, how they relate to constructivist teaching beliefs, and how they may...

Purpose To examine the effect of breast shielding on blood lymphocyte deoxyribonucleic acid (DNA) double-strand-break levels resulting from in vivo radiation and ex vivo radiation at breast-tissue level, and the effect of breast shielding on image quality. Materials and Methods The study was approved by institutional review and commpliant with HIPAA guidelines. Adult women who underwent 64-section coronary computed tomographic (CT) angiography and who provided informed consent were prospectively randomized to the use (n = 50) or absence (n = 51) of bismuth breast shields. Peripheral blood samples were obtained before and 30 minutes after in vivo radiation during CT angiography to compare DNA double-strand-break levels by γ-H2AX immunofluorescence in blood lymphocytes. To estimate DNA double-strand-break induction at breast-tissue level, a blood sample was taped to the sternum for ex vivo radiation with or without shielding. Data were analyzed by linear regression and independent sample t tests. Results Breast shielding had no effect on DNA double-strand-break levels from ex vivo radiation of blood samples under shields at breast-tissue level (unadjusted regression: β = .08; P = .43 versus no shielding), or in vivo radiation of circulating lymphocytes (β = -.07; P = .50). Predictors of increased DNA double-strand-break levels included total radiation dose, increasing tube potential, and tube current (P < .05). With current radiation exposures (median, 3.4 mSv), breast shielding yielded a 33% increase in image noise and 19% decrease in the rate of excellent quality ratings. Conclusion Among women who underwent coronary CT angiography, breast shielding had no effect on DNA double-strand-break levels in blood lymphocytes exposed to in vivo radiation, or ex vivo radiation at breast-tissue level. At present relatively low radiation exposures, breast shielding contributed to an increase in image noise and a decline in image quality. The findings support efforts to minimize radiation by primarily optimizing CT settings. (©) RSNA, 2016 Clinical trial registration no. NCT02617888 Online supplemental material is available for this article.

The development of novel cancer treatments is a challenging task, partly because results from model systems often fail to predict drug efficacy in humans, and also tumors are often inaccessible for biochemical analysis, preventing effective monitoring of drug activity in vivo. Utilizing a model system, we evaluated the use of drug‐induced DNA damage in surrogate tissues as indicators of drug efficacy. Samples of a commercially available melanoma skin model (Mattek MLNM‐FT‐A375) containing keratinocyte and fibroblast layers with melanoma nodules were subjected to various chemotherapeutic regimens for one, four, or eight days. At these times they were analyzed for DNA double‐stranded breaks (γH2AX foci) and apoptosis (TUNEL). A wide range of drug responses in both tumor and normal tissues were observed and cataloged. For the melanoma, the most common drug response was apoptosis. The basal keratinocyte layer, which was the most reliable indicator of drug response in the melanoma skin model, responded with γH2AX foci formation that was abrupt and transient. The relationships between tumor and surrogate tissue drug responses are complex, indicating that while surrogate tissue drug responses may be useful clinical tools, careful control of variables such as the timing of sampling may be important in interpreting the results.

Indenoisoquinolines are non-camptothecin topoisomerase I (TopI) inhibitors that overcome the limitations of camptothecins: chemical instability and camptothecin resistance. Two dosing schedules of the novel indenoisoquinoline, indotecan (LMP400), were evaluated in patients with advanced solid tumors. The maximum tolerated dose (MTD), toxicities, and pharmacokinetics of two indotecan drug administration schedules (daily for 5 days or weekly) were investigated. Modulation of TopI and the phosphorylation of histone H2AX (γH2AX) were assayed in tumor biopsies; γH2AX levels were also evaluated in circulating tumor cells (CTCs) and hair follicles to assess DNA damage response. An MTD of 60 mg/m2/day was established for the daily regimen, compared to 90 mg/m2 for the weekly regimen. The TopI response to drug showed target engagement in a subset of tumor biopsies. Pharmacokinetics profiles demonstrated a prolonged terminal half-life and tissue accumulation compared to topotecan. Dose-dependent decreases in total CTCs were measured in seven patients. Formation of γH2AX-positive foci in CTCs (day 3) and hair follicles (4–6 h) was observed following treatment. We established the MTD of two dosing schedules for a novel TopI inhibitor, indotecan. Target engagement was demonstrated as Top1 downregulation and γH2AX response. No objective responses were observed on either schedule in this small patient cohort. The principal toxicity of both schedules was myelosuppression; no significant gastrointestinal problems were observed. Increased DNA damage response was observed in CTCs, hair follicles, and a subset of tumor biopsies.

We studied relationships between mathematical knowledge, beliefs about teaching and learning, and instructional planning. We contrasted beliefs, mathematical knowledge, and skills of preservice teachers (n = 47) with those of inservice teachers (n = 31) at the primary school level. For both groups, participants were generally more constructivist than traditional in beliefs, and showed evidence of low conceptual knowledge in mathematics. Multiple regression analyses indicated different relationships between conceptual knowledge and constructivist beliefs for inservice versus preservice teachers. Conceptual knowledge played a strong role in instructional planning in mathematics. Implications for future research and teacher education are discussed based on these findings.

Whereas stigma regarding mental health concerns exists, the evidence for stigma as a depression treatment barrier among patients in Veterans Affairs (VA) primary care (PC) is mixed.This study tests whether stigma, defined as depression label avoidance, predicted patients' preferences for depression treatment providers, patients' prospective engagement in depression care, and care quality.We conducted cross-sectional and prospective analyses of existing data from 761 VA PC patients with probable major depression.Relative to low-stigma patients, those with high stigma were less likely to prefer treatment from mental health specialists. In prospective controlled analyses, high stigma predicted lower likelihood of the following: taking medications for mood, treatment by mental health specialists, treatment for emotional concerns in PC, and appropriate depression care.High stigma is associated with lower preferences for care from mental health specialists and confers risk for minimal depression treatment engagement.

We present research on the development of diode-pumped solid-state lasers suitable for quantum technologies applications at 698.45 nm and 780.24 nm targeting strontium (Sr) and rubidium (Rb) transitions.

Background: Germline variants in the melanocortin 1 receptor gene (MC1R) might increase the risk of childhood and adolescent melanoma, but a clear conclusion is challenging because of the low number of studies and cases. We assessed the association of MC1R variants with childhood and adolescent melanoma in a large study comparing the prevalence of MC1R variants in child or adolescent patients with melanoma to that in adult patients with melanoma and in healthy adult controls. Methods: In this retrospective pooled analysis, we used the M-SKIP Project, the Italian Melanoma Intergroup, and other European groups (with participants from Australia, Canada, France, Greece, Italy, the Netherlands, Serbia, Spain, Sweden, Turkey, and the USA) to assemble an international multicentre cohort. We gathered phenotypic and genetic data from children or adolescents diagnosed with sporadic single-primary cutaneous melanoma at age 20 years or younger, adult patients with sporadic single-primary cutaneous melanoma diagnosed at age 35 years or older, and healthy adult individuals as controls. We calculated odds ratios (ORs) for childhood and adolescent melanoma associated with MC1R variants by multivariable logistic regression. Subgroup analysis was done for children aged 18 or younger and 14 years or younger. Findings: We analysed data from 233 young patients, 932 adult patients, and 932 healthy adult controls. Children and adolescents had higher odds of carrying MC1R r variants than did adult patients (OR 1·54, 95% CI 1·02–2·33), including when analysis was restricted to patients aged 18 years or younger (1·80, 1·06–3·07). All investigated variants, except Arg160Trp, tended, to varying degrees, to have higher frequencies in young patients than in adult patients, with significantly higher frequencies found for Val60Leu (OR 1·60, 95% CI 1·05–2·44; p=0·04) and Asp294His (2·15, 1·05–4·40; p=0·04). Compared with those of healthy controls, young patients with melanoma had significantly higher frequencies of any MC1R variants. Interpretation: Our pooled analysis of MC1R genetic data of young patients with melanoma showed that MC1R r variants were more prevalent in childhood and adolescent melanoma than in adult melanoma, especially in patients aged 18 years or younger. Our findings support the role of MC1R in childhood and adolescent melanoma susceptibility, with a potential clinical relevance for developing early melanoma detection and preventive strategies. Funding: SPD-Pilot/Project-Award-2015; AIRC-MFAG-11831. © 2019 Elsevier Ltd

Q-switched lasers operating at wavelengths around 2 µm have many applications including materials processing and LIDAR. However, the low gain of the quasi-three-level gain media available at 2 µm can lead to problems with pulse-to-pulse fluctuations in their output, known as jitter. Here we present a methodology for characterising the level of jitter in a Q-switched laser and apply it to a Tm:YAP system. We also look at the causes of jitter and evaluate some methods of reducing it. The methodology developed here will aid in the development and characterisation of Q-switched lasers at any wavelength.

During ovarian development stroma from the mesonephros penetrates and expands into the ovarian primordium and thus appears to be involved, at least physically, in the formation of ovigerous cords, follicles and surface epithelium. Cortical stromal development during gestation in bovine fetal ovaries (n=27) was characterised by immunohistochemistry and by mRNA analyses. Stroma was identified by immunostaining of stromal matrix collagen type I and proliferating cells were identified by Ki67 expression. The cortical and medullar volume expanded across gestation, with the rate of cortical expansion slowing over time. During gestation, the proportion of stroma in the cortex and total volume in the cortex significantly increased (P0.05). The expression levels of 12 genes out of 18 examined, including osteoglycin (OGN) and lumican (LUM), were significantly increased later in development (P

Background Annexin A2 is increased in serous ovarian cancer and plays an essential role in ovarian cancer invasion and metastasis. In combination with S100A10, annexin A2 plays an important role in the plasminogen activator system regulating plasmin production. The aim of this study was to investigate the potential utility of all-trans retinoid acid (ATRA), an inhibitor of the annexin A2-S100A10 signalling pathway, as a new therapeutic against serous ovarian cancer. Methods In this study we determined the effects of ATRA treatment (1-5 μM) on annexin A2 and S100A10 expression, plasmin activation, and the ability of ATRA to inhibit serous ovarian cancer cell survival, motility and invasion in vitro. We also employed an ex vivo tissue explant assay to assess response to ATRA treatment in serous ovarian cancers. Cryopreserved serous ovarian cancer tissues were cultured on gelatin sponges for 72 h with ATRA (1 μM). Effects on apoptosis and proliferation were assessed by immunohistochemistry using antibodies to cleaved caspase 3 or Ki67, respectively. Results Survival of serous ovarian cancer cells (OVCAR-3, OV-90, & OAW28) was significantly decreased by ATRA treatment (1-5 μM). ATRA (1 μM) also significantly decreased proliferation (Ki67 positivity, p = 0.0034), S100A10 protein levels (p = 0.0273), and increased cell apoptosis (cleaved caspase-3 positivity, p = 0.0024) in serous ovarian cancer tissues using the ex vivo tissue explant assay. In OAW28 cells, reduced cell survival following ATRA treatment was associated with a reduction of S100A10 mRNA and protein levels, S100A10 and annexin A2 membrane localization, plasmin generation, motility and invasion. In contrast, ATRA inhibited OV-90 cell survival and invasion but did not affect plasmin activation or S100A10 and annexin A2 expression or membrane localization. Conclusions These findings suggest that ATRA inhibits serous ovarian cancer proliferation and invasion via both S100A10 dependant and S100A10 independent mechanisms. Our results show that ATRA has promising potential as a novel therapy against serous ovarian cancer that warrants further evaluation. Electronic supplementary material The online version of this article (10.1186/s13046-018-1017-7) contains supplementary material, which is available to authorized users.

Forensic science is critical to the administration of justice. The discipline of forensic science is remarkably complex and includes methodologies ranging from DNA analysis to chemical composition to pattern recognition. Many forensic practices developed under the auspices of law enforcement and were vetted primarily by the legal system rather than being subjected to scientific scrutiny and empirical testing. Beginning in the 1990s, exonerations based on DNA-related methods revealed problems with some forensic disciplines, leading to calls for major reforms. This process generated a National Academy of Science report in 2009 that was highly critical of many forensic practices and eventually led to the establishment of the National Commission for Forensic Science (NCFS) in 2013. The NCFS was a deliberative body that catalyzed communication between nonforensic scientists, forensic scientists, and other stakeholders in the legal community. In 2017, despite continuing problems with forensic science, the Department of Justice terminated the NCFS. Just when forensic science needs the most support, it is getting the least. We urge the larger scientific community to come to the aid of our forensic colleagues by advocating for urgently needed research, testing, and financial support.

The definition of who has epilepsy, classification of seizure types, and types of epilepsy have all recently been revised. The classical definition of epilepsy as a person having two or more unprovoked seizures more than 24 hours apart has been expanded also to include those with one seizure and a high likelihood (more than 60%) of having another. In the new definition, epilepsy is considered to be resolved when a person is seizure-free for 10 years, the terminal 5 being off seizure medicines, or when an age-dependent syndrome has been outgrown. The new seizure type classification revises the 1981 system but maintains the primary distinction of focal- versus generalized-onset seizures. Seizures also can be of unknown onset. Focal seizures may demonstrate retention or impairment of awareness, resulting in focal-aware or focal-impaired awareness seizures. Several new focal and generalized seizure types are introduced. Classification of the epilepsies is now by grouping of seizure types, etiologies, comorbidities, and epilepsy syndromes. The goal of the new terminology is greater clarity of communication and more accurate grouping of seizure types for research. Neurodiagnostic technologists can be of great help in observing clinical and electrographic features that will define the type of seizure.

The Peer Enabled Restructured Classroom (PERC) is an instructional innovation developed to address gaps in science, technology, engineering, and math (STEM) in urban high schools. The PERC model changes instruction from teacher led to peer led by bringing peer students into the classroom to lead small-group work. Our study sought to provide empirical evidence in support of the peer-led model as a means of improving STEM learning for tutored students in urban schools. We used propensity score matching to evaluate the innovation's impact on students’ achievement on standardized end-of-course tests in two 9th-grade courses – Integrated Algebra and Biology. Results suggest that by the 2nd year of implementation, enrolment in PERC Biology increased the likelihood of passing. Similar effects were not observed for PERC Integrated Algebra, but when comparing cohorts, we found that the 2nd year was twice as likely to pass as the 1st year. We discuss implications for programme improvement.

Despite significant advances in the treatment of Hodgkin's lymphoma (HL), a significant proportion of patients will not respond or will subsequently relapse. We identified CD25, the IL-2 receptor alpha subunit, as a favorable target for systemic radioimmunotherapy of HL. The scientific basis for the clinical trial was that, although most normal cells with exception of Treg cells do not express CD25, it is expressed by a minority of Reed-Sternberg cells and by most polyclonal T cells rosetting around Reed-Sternberg cells. Forty-six patients with refractory and relapsed HL were evaluated with up to seven i.v. infusions of the radiolabeled anti-CD25 antibody (90)Y-daclizumab. (90)Y provides strong β emissions that kill tumor cells at a distance by a crossfire effect. In 46 evaluable HL patients treated with (90)Y-daclizumab there were 14 complete responses and nine partial responses; 14 patients had stable disease, and nine progressed. Responses were observed both in patients whose Reed-Sternberg cells expressed CD25 and in those whose neoplastic cells were CD25(-) provided that associated rosetting T cells expressed CD25. As assessed using phosphorylated H2AX (γ-H2AX) as a bioindicator of the effects of radiation exposure, predominantly nonmalignant cells in the tumor microenvironment manifested DNA damage, as reflected by increased expression of γ-H2AX. Toxicities were transient bone-marrow suppression and myelodysplastic syndrome in six patients who had not been evaluated with bone-marrow karyotype analyses before therapy. In conclusion, repeated (90)Y-daclizumab infusions directed predominantly toward nonmalignant T cells rosetting around Reed-Sternberg cells provided meaningful therapy for select HL patients.

Hintergrund Schwerverletzte werden durch die gesetzliche Unfallversicherung im Rahmen eines Reha-Managements betreut.

Measuring the linewidth of single-frequency lasers is challenging, and great care must be taken to understand the capabilities and limitations of different measurement techniques to obtain consistent results. A detailed comparative study will be presented.

Purpose: DMS612 is a dimethane sulfonate analog with bifunctional alkylating activity and preferential cytotoxicity to human renal cell carcinoma (RCC) in the NCI-60 cell panel. This first-in-human phase I study aimed to determine dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetics (PK), and pharmacodynamics (PD) of DMS612 administered by 10-minute intravenous infusion on days 1, 8, and 15 of an every-28-day schedule. Experimental Design: Patients with advanced solid malignancies were eligible. Enrollment followed a 3+3 design. PKs of DMS612 and metabolites were assessed by mass spectroscopy and PD by γ-H2AX immunofluorescence. Results: A total of 31 patients, including those with colorectal (11), RCC (4), cervical (2), and urothelial (1) cancers, were enrolled. Six dose levels were studied, from 1.5 mg/m2 to 12 mg/m2. DLTs of grade 4 neutropenia and prolonged grade 3 thrombocytopenia were observed at 12 mg/m2. The MTD was determined to be 9 mg/m2 with a single DLT of grade 4 thrombocytopenia in 1 of 12 patients. Two patients had a confirmed partial response at the 9 mg/m2 dose level, in renal (1) and cervical (1) cancer. DMS612 was rapidly converted into active metabolites. γ-H2AX immunofluorescence revealed dose-dependent DNA damage in both peripheral blood lymphocytes and scalp hairs. Conclusions: The MTD of DMS12 on days 1, 8, and 15 every 28 days was 9 mg/m2. DMS612 appears to be an alkylating agent with unique tissue specificities. Dose-dependent PD signals and two partial responses at the MTD support further evaluation of DMS612 in phase II trials. Clin Cancer Res; 21(4); 721–9. ©2014 AACR.

Ataxia telangiectasia (A-T), a rare autosomal recessive disorder characterized by progressive cerebellar degeneration and a greatly increased incidence of cancer among other symptoms, is caused by a defective or missing ataxia telangiectasia mutated (ATM) gene. The ATM protein has roles in DNA repair and in the regulation of reactive oxygen species (ROS). Here, we provide, to our knowledge, the first evidence that NADPH oxidase 4 (NOX4) is involved in manifesting A-T disease. We showed that NOX4 expression levels are higher in A-T cells, and that ATM inhibition leads to increased NOX4 expression in normal cells. A-T cells exhibit elevated levels of oxidative DNA damage, DNA double-strand breaks and replicative senescence, all of which are partially abrogated by down-regulation of NOX4 with siRNA. Sections of degenerating cerebelli from A-T patients revealed elevated NOX4 levels. ATM-null mice exhibit A-T disease but they die from cancer before the neurological symptoms are manifested. Injecting Atm-null mice with fulvene-5, a specific inhibitor of NOX4 and NADPH oxidase 2 (NOX2), decreased their elevated cancer incidence to that of the controls. We conclude that, in A-T disease in humans and mice, NOX4 may be critical mediator and targeting it will open up new avenues for therapeutic intervention in neurodegeneration.

Studies of selenium (Se) status indicate that Se is necessary for fertility but how precisely is not known. We aimed to show that Se was important in bovine female reproductive function. The elemental distribution in the bovine ovary (n = 45 sections) was identified by X-ray fluorescence (XRF) imaging. Se was consistently localized to the granulosa cell layer of large (>10 mm) healthy follicles. Inductively Coupled Plasma – Mass Spectrometry revealed tenfold higher Se in the bovine follicle wall compared to corpora lutea. Gene expression analysis of selenoprotein genes GPX1, GPX3, VIMP and SELM in bovine granulosa cells revealed that only GPX1 was significantly up-regulated in large healthy follicles compared to the small healthy or atretic follicles (P < 0.05). Western immunoblotting identified GPX1 protein in bovine granulosa cells of large healthy follicles, but not of small healthy follicles. To assess if GPX1 was important in human follicles, cumulus cells from women undergoing IVF/ICSI with single embryo transfer were collected. Oocytes and embryos were cultured and transferred independently in 30 patients undergoing elective single embryo transfer. Gene expression of GPX1 was significantly higher in human cumulus cells from cumulus–oocyte complexes yielding a pregnancy (P < 0.05). We present the first XRF imaging of mammalian ovaries showing that Se is consistently localized to the granulosa cells of large healthy follicles. We conclude that Se and selenoproteins are elevated in large healthy follicles and may play a critical role as an antioxidant during late follicular development.

Rationale: FVC percent predicted (FVC%) is the primary outcome measure in clinical trials of systemic sclerosis interstitial lung disease. For interpretation of change in the FVC% over time, it is important to define whether these changes are clinically meaningful. Objectives:: To assess the reliability and the minimal clinically important differences (MCID) for FVC% in the Scleroderma Lung Study I and II (SLS-I and -II). Methods: Using data from SLS-I and -II (N = 300), we evaluated the test-retest reliability for FVC% (screening vs. baseline) using intraclass correlation. MCID estimates at 12 months were calculated in the pooled cohort (SLS-I and -II) using two anchors: Transition Dyspnea Index (≥change of 1.5 units for improvement and worsening, respectively) and the Medical Outcomes Short Form-36 Health Transition question (“Compared with one year ago, how would you rate your health in general now”?), where “somewhat better” or “somewhat worse” were defined as the MCID estimates. We next assessed the association of MCID estimates for improvement and worsening of FVC% with patient-reported outcomes (PROs) and computer-assisted quantitation of extent of fibrosis (QLF) and of total interstitial lung disease (QILD) on high-resolution computed tomography. Student’s t test was used to compare the mean difference in outcomes between the MCID improvement/worsening and the “no change” group. Measurements and Main Results: Reliability of FVC%, assessed at a mean of 34 days, intraclass correlation was 0.93 for the pooled cohort. The MCID estimates for the pooled cohort at 12 months for FVC% improvement ranged from 3.0% to 5.3% and for worsening from −3.0% to −3.3%. FVC% improvement by greater than or equal to MCID was associated with either statistically significant or numerical improvements in some PROs, QILD, and QLF, whereas FVC% worsening greater than or equal to MCID was associated with statistically significant or numerical worsening of PROs, QILD, and QLF. Conclusions: FVC% has acceptable test-retest reliability, and we have provided the MCID estimates for FVC% in systemic sclerosis interstitial lung disease–based changes at 12 months from baseline in two clinical trials. Clinical trial registered with www.clinicaltrials.gov (NCT00004563 for SLS-I and NCT00883129 for SLS-II).

Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification—highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications—highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.

The majority of ovarian cancer patients present with advanced disease and despite aggressive treatment, prognosis remains poor. Response to first-line carboplatin-containing chemotherapy is usually good, however, recurrence rates and subsequent chemoresistance are very high and ultimately responsible for the fatal outcome of the disease. To improve treatment outcomes pre-clinical models that can predict individual patient response to 1st line chemotherapy and novel therapeutics are urgently required. In this study, we employed an ex vivo ovarian cancer tissue explant assay to assess response to carboplatin and an inhibitor of the extracellular matrix molecule, hyaluronan (4-methylubelliferone, 4-MU), shown to inhibit cancer metastasis. Cryopreserved ovarian cancer tissues were cultured on gelatine sponges for 48-120 h with increasing concentrations of carboplatin (0-400 mu M) or 4-MU (1 mM) alone or the combination of both drugs. Effects on apoptosis and proliferation were assessed by immunohistochemistry using antibodies to cleaved caspase 3 or Ki67, respectively. The ex vivo tissue explant assay maintained viable tumor cells in an intact tumor microenvironment similar to the in vivo situation over the 120 h culture period. Carboplatin treatment promoted apoptosis in chemosensitive (P = 0.0047) but not chemoresistant cancer tissues. The combination of 4-MU (1 mM) and carboplatin (100 mu M) significantly increased apoptosis (P = 0.0111) and reduced proliferation (P = 0.0064) in chemoresistant tissues. Overall, our results show that the ex vivo explant assay is a robust and cost effective model to assess chemosensitivity and the effect of novel therapeutics in ovarian cancer. Refereed/Peer-reviewed

The senescence of mammalian cells is characterized by a proliferative arrest in response to stress and the expression of an inflammatory phenotype. Here we show that histone H2A.J, a poorly studied H2A variant found only in mammals, accumulates in human fibroblasts in senescence with persistent DNA damage. H2A.J also accumulates in mice with aging in a tissue-specific manner and in human skin. Knock-down of H2A.J inhibits the expression of inflammatory genes that contribute to the senescent-associated secretory phenotype (SASP), and over expression of H2A.J increases the expression of some of these genes in proliferating cells. H2A.J accumulation may thus promote the signalling of senescent cells to the immune system, and it may contribute to chronic inflammation and the development of aging-associated diseases., Senescence of mammalian cells is characterized by proliferative arrest and expression of an inflammatory phenotype. Here the authors show the H2A variant H2A.J, found only in mammals, accumulates following persistent DNA damage or natural aging.

Recent integrative epigenome analyses highlight the importance of functionally distinct chromatin states for accurate cell function. How these states are established and maintained is a matter of intense investigation. Here, we present evidence for DNA damage as an unexpected means to shape a protective chromatin environment at regions of recurrent replication stress (RS). Upon aberrant fork stalling, DNA damage signaling and concomitant H2AX phosphorylation coordinate the FACT-dependent deposition of macroH2A1.2, a histone variant that promotes DNA repair by homologous recombination (HR). MacroH2A1.2, in turn, facilitates the accumulation of the tumor suppressor and HR effector BRCA1 at replication forks to protect from RS-induced DNA damage. Consequently, replicating primary cells steadily accrue macroH2A1.2 at fragile regions, whereas macroH2A1.2 loss in these cells triggers DNA damage signaling-dependent senescence, a hallmark of RS. Altogether, our findings demonstrate that recurrent DNA damage contributes to the chromatin landscape to ensure the epigenomic integrity of dividing cells.

Recently we found that mice bearing subcutaneous non-metastatic tumors exhibited elevated levels of two types of complex DNA damage, i.e., double-strand breaks and oxidatively-induced clustered DNA lesions in various tissues throughout the body, both adjacent to and distant from the tumor site. This DNA damage was dependent on CCL2, a cytokine involved in the recruitment and activation of macrophages, suggesting that this systemic DNA damage was mediated via tumor-induced chronic inflammatory responses involving cytokines, activation of macrophages, and consequent free radical production. If free radicals are involved, then a diet containing an antioxidant may decrease the distant DNA damage. Here we repeated our standard protocol in cohorts of two syngeneic tumor-bearing C57BL/6NCr mice that were on a Tempol-supplemented diet. We show that double-strand break and oxidatively-induced clustered DNA lesion levels were considerably decreased, about two- to three fold, in the majority of tissues studied from the tumor-bearing mice fed the antioxidant Tempol compared to the control tumor-bearing mice. Similar results were also observed in nude mice suggesting that the Tempol effects are independent of functioning adaptive immunity. This is the first in vivo study demonstrating the effect of a dietary antioxidant on abscopal DNA damage in tissues distant from a localized source of genotoxic stress. These findings may be important for understanding the mechanisms of genomic instability and carcinogenesis caused by chronic stress-induced systemic DNA damage and for developing preventative strategies.