251 research outputs found

    Non-invasive scoring of cellular atypia in keratinocyte cancers in 3D LC-OCT images using Deep Learning

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    Diagnosis based on histopathology for skin cancer detection is today's gold standard and relies on the presence or absence of biomarkers and cellular atypia. However it suffers drawbacks: it requires a strong expertise and is time-consuming. Moreover the notion of atypia or dysplasia of the visible cells used for diagnosis is very subjective, with poor inter-rater agreement reported in the literature. Lastly, histology requires a biopsy which is an invasive procedure and only captures a small sample of the lesion, which is insufficient in the context of large fields of cancerization. Here we demonstrate that the notion of cellular atypia can be objectively defined and quantified with a non-invasive in-vivo approach in three dimensions (3D). A Deep Learning (DL) algorithm is trained to segment keratinocyte (KC) nuclei from Line-field Confocal Optical Coherence Tomography (LC-OCT) 3D images. Based on these segmentations, a series of quantitative, reproducible and biologically relevant metrics is derived to describe KC nuclei individually. We show that, using those metrics, simple and more complex definitions of atypia can be derived to discriminate between healthy and pathological skins, achieving Area Under the ROC Curve (AUC) scores superior than 0.965, largely outperforming medical experts on the same task with an AUC of 0.766. All together, our approach and findings open the door to a precise quantitative monitoring of skin lesions and treatments, offering a promising non-invasive tool for clinical studies to demonstrate the effects of a treatment and for clinicians to assess the severity of a lesion and follow the evolution of pre-cancerous lesions over time.© 2022. The Author(s)

    Measurement of double beta decay of ¹⁰⁰Mo to excited states in the NEMO 3 experiment

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    The double beta decay of ¹⁰⁰Mo to the 0_{1}^{+} and 2_{1}^{+} excited states of ¹⁰⁰Ru is studied using the NEMO 3 data. After the analysis of 8024 h of data the half-life for the two-neutrino double beta decay of ¹⁰⁰Mo to the excited 0_{1}^{+} state is measured to be T_{1/2}^{2v} = [5.7_{-0.9}^{+1.3} (stat.) ± 0.8 (syst.)] x 10²⁰ y. The signal-to-background ratio is equal to 3. Information about energy and angular distributions of emitted electrons is also obtained. No evidence for neutrinoless double beta decay to the excited 0_{1}^{+} state has been found. The corresponding half-life limit is T_{1/2}^{0v} (0⁺→0_{1}^{+}) > 8.9 x 10²² y (at 90% C.L.). The search for the double beta decay to the 2_{1}^{+} excited state has allowed the determination of limits on the half-life for the two neutrino mode T_{1/2}^{0v} (0⁺→2_{1}^{+}) > 1.1 x 10²¹ y (at 90% C.L.) and for the neutrinoless mode T_{1/2}^{0v} (0⁺→2_{1}^{+}) > 1.6 x 10²³ y (at 90% C.L.)

    The Depolarizing Action of GABA in Cultured Hippocampal Neurons Is Not Due to the Absence of Ketone Bodies

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    Two recent reports propose that the depolarizing action of GABA in the immature brain is an artifact of in vitro preparations in which glucose is the only energy source. The authors argue that this does not mimic the physiological environment because the suckling rats use ketone bodies and pyruvate as major sources of metabolic energy. Here, we show that availability of physiologically relevant levels of ketone bodies has no impact on the excitatory action of GABA in immature cultured hippocampal neurons. Addition of β-hydroxybutyrate (BHB), the primary ketone body in the neonate rat, affected neither intracellular calcium elevation nor membrane depolarizations induced by the GABA-A receptor agonist muscimol, when assessed with calcium imaging or perforated patch-clamp recording, respectively. These results confirm that the addition of ketone bodies to the extracellular environment to mimic conditions in the neonatal brain does not reverse the chloride gradient and therefore render GABA hyperpolarizing. Our data are consistent with the existence of a genuine “developmental switch” mechanism in which GABA goes from having a predominantly excitatory role in immature cells to a predominantly inhibitory one in adults

    Towards the Physical Map of the Trypanosoma cruzi Nuclear Genome: Construction of YAC and BAC Libraries of the Reference Clone T. cruzi CL-Brener

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    Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas diseaseInstituto de Investigaciones en Ingeniería Genética y Biología MolecularEscola Paulista de MedicinaCBMUniversidade de São PauloUniversidade Federal do Rio de JaneiroIPBUniversidad Central de VenezuelaUSBInstituto Oswaldo CruzCEPHUNIFESP, EPMSciEL

    Role of biomarkers in early infectious complications after lung transplantation

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    Background Infections and primary graft dysfunction are devastating complications in the immediate postoperative period following lung transplantation. Nowadays, reliable diagnostic tools are not available. Biomarkers could improve early infection diagnosis. Methods Multicentre prospective observational study that included all centres authorized to perform lung transplantation in Spain. Lung infection and/or primary graft dysfunction presentation during study period (first postoperative week) was determined. Biomarkers were measured on ICU admission and daily till ICU discharge or for the following 6 consecutive postoperative days. Results We included 233 patients. Median PCT levels were significantly lower in patients with no infection than in patients with Infection on all follow up days. PCT levels were similar for PGD grades 1 and 2 and increased significantly in grade 3. CRP levels were similar in all groups, and no significant differences were observed at any study time point. In the absence of PGD grade 3, PCT levels above median (0.50 ng/ml on admission or 1.17 ng/ml on day 1) were significantly associated with more than two- and three-fold increase in the risk of infection (adjusted Odds Ratio 2.37, 95% confidence interval 1.06 to 5.30 and 3.44, 95% confidence interval 1.52 to 7.78, respectively). Conclusions In the absence of severe primary graft dysfunction, procalcitonin can be useful in detecting infections during the first postoperative week. PGD grade 3 significantly increases PCT levels and interferes with the capacity of PCT as a marker of infection. PCT was superior to CRP in the diagnosis of infection during the study period

    The Eat Smart Study: A randomised controlled trial of a reduced carbohydrate versus a low fat diet for weight loss in obese adolescents

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    Background Despite the recognition of obesity in young people as a key health issue, there is limited evidence to inform health professionals regarding the most appropriate treatment options. The Eat Smart study aims to contribute to the knowledge base of effective dietary strategies for the clinical management of the obese adolescent and examine the cardiometablic effects of a reduced carbohydrate diet versus a low fat diet. Methods and design Eat Smart is a randomised controlled trial and aims to recruit 100 adolescents over a 2½ year period. Families will be invited to participate following referral by their health professional who has recommended weight management. Participants will be overweight as defined by a body mass index (BMI) greater than the 90th percentile, using CDC 2000 growth charts. An accredited 6-week psychological life skills program ‘FRIENDS for Life’, which is designed to provide behaviour change and coping skills will be undertaken prior to volunteers being randomised to group. The intervention arms include a structured reduced carbohydrate or a structured low fat dietary program based on an individualised energy prescription. The intervention will involve a series of dietetic appointments over 24 weeks. The control group will commence the dietary program of their choice after a 12 week period. Outcome measures will be assessed at baseline, week 12 and week 24. The primary outcome measure will be change in BMI z-score. A range of secondary outcome measures including body composition, lipid fractions, inflammatory markers, social and psychological measures will be measured. Discussion The chronic and difficult nature of treating the obese adolescent is increasingly recognised by clinicians and has highlighted the need for research aimed at providing effective intervention strategies, particularly for use in the tertiary setting. A structured reduced carbohydrate approach may provide a dietary pattern that some families will find more sustainable and effective than the conventional low fat dietary approach currently advocated. This study aims to investigate the acceptability and effectiveness of a structured reduced dietary carbohydrate intervention and will compare the outcomes of this approach with a structured low fat eating plan. Trial Registration: The protocol for this study is registered with the International Clinical Trials Registry (ISRCTN49438757)

    In vitro irradiation of basement membrane enhances the invasiveness of breast cancer cells

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    Following removal of the primary breast tumour by conservative surgery, patients may still have additional malignant foci scattered throughout the breast. Radiation treatments are not designed to eliminate all these residual cancer cells. Rather, the radiation dose is calculated to optimise long-term results with minimal complications. In a tumour, cancer cells are surrounded by a basement membrane, which plays an important role in the regulation of gene expression. Using an invasion chamber, we have shown that irradiation before cell plating of a reconstituted basement membrane (Matrigel; Becton Dickinson, Bedford, MA, USA) increased the invasiveness of the breast cancer cells MDA-MB-231. This radiation enhancement of invasion was associated with the upregulation of the pro-invasive gene matrix metalloproteinase (MMP)-2. The expression of membrane type 1 matrix metalloproteinase (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP), which are required to activate the MMP-2, were also increased. Confirming the role of MMP-2 and MT1-MMP, radiation enhancement of cancer cell invasion was prevented by an MMP-2 inhibitor and an anti-MT1-MMP antibody. This study also demonstrated that radiation can potentially enhance the invasion ability by inducing the release of pro-invasive factors stored in the Matrigel. Conversely, no enhancement of invasiveness was observed with the low metastatic cell line MCF-7. This lack of invasiveness correlated with the absence of the MMP-2 activator MT1-MMP in the MCF-7 cells. Radiotherapy is an efficient modality to treat breast cancer which could be further improved by inhibiting the pro-invasive gene upregulated by radiation

    Protection from pulmonary ischemia-reperfusion injury by adenosine A2A receptor activation

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    <p>Abstract</p> <p>Background</p> <p>Lung ischemia-reperfusion (IR) injury leads to significant morbidity and mortality which remains a major obstacle after lung transplantation. However, the role of various subset(s) of lung cell populations in the pathogenesis of lung IR injury and the mechanisms of cellular protection remain to be elucidated. In the present study, we investigated the effects of adenosine A<sub>2A </sub>receptor (A<sub>2A</sub>AR) activation on resident lung cells after IR injury using an isolated, buffer-perfused murine lung model.</p> <p>Methods</p> <p>To assess the protective effects of A<sub>2A</sub>AR activation, three groups of C57BL/6J mice were studied: a sham group (perfused for 2 hr with no ischemia), an IR group (1 hr ischemia + 1 hr reperfusion) and an IR+ATL313 group where ATL313, a specific A<sub>2A</sub>AR agonist, was included in the reperfusion buffer after ischemia. Lung injury parameters and pulmonary function studies were also performed after IR injury in A<sub>2A</sub>AR knockout mice, with or without ATL313 pretreatment. Lung function was assessed using a buffer-perfused isolated lung system. Lung injury was measured by assessing lung edema, vascular permeability, cytokine/chemokine activation and myeloperoxidase levels in the bronchoalveolar fluid.</p> <p>Results</p> <p>After IR, lungs from C57BL/6J wild-type mice displayed significant dysfunction (increased airway resistance, pulmonary artery pressure and decreased pulmonary compliance) and significant injury (increased vascular permeability and edema). Lung injury and dysfunction after IR were significantly attenuated by ATL313 treatment. Significant induction of TNF-α, KC (CXCL1), MIP-2 (CXCL2) and RANTES (CCL5) occurred after IR which was also attenuated by ATL313 treatment. Lungs from A<sub>2A</sub>AR knockout mice also displayed significant dysfunction, injury and cytokine/chemokine production after IR, but ATL313 had no effect in these mice.</p> <p>Conclusion</p> <p>Specific activation of A<sub>2A</sub>ARs provides potent protection against lung IR injury via attenuation of inflammation. This protection occurs in the absence of circulating blood thereby indicating a protective role of A<sub>2A</sub>AR activation on resident lung cells such as alveolar macrophages. Specific A<sub>2A</sub>AR activation may be a promising therapeutic target for the prevention or treatment of pulmonary graft dysfunction in transplant patients.</p

    Synergistic effect of stromelysin-1 (matrix metalloproteinase-3) promoter (-1171 5A->6A) polymorphism in oral submucous fibrosis and head and neck lesions

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    <p>Abstract</p> <p>Background</p> <p>Matrix metalloproteinases (MMPs) are enzymes that degrade all the components of extra cellular matrix and collagen. Various types of MMPs are known to be expressed and activated in patients with oral submucous fibrosis (OSMF) as well as head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to asses the association of the single nucleotide polymorphism (SNP) adenosine insertion/deletion polymorphism (-1171 5A->6A) in the MMP-3 promoter region in these lesions.</p> <p>Methods</p> <p>MMP-3 SNP was genotyped by polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) analysis in a case control study consisting of 362 participants; 101 cases of OSMF, 135 of HNSCC and 126 controls, compared for age, sex and habits. ROC distribution was plotted to assess the contributions of genetic variation in MMP-3 genotypes with relation to age.</p> <p>Results</p> <p>Analysis of MMP 3 (-1171 5A->6A) polymorphism revealed the frequency of 5A allele in OSMF, HNSCC and controls to be 0.15, 0.13 and 0.07, respectively. A significant difference was found in 5A genotype frequency between OSMF (5A genotype frequency = 0.15, p = 0.01, OR = 2.26, 95% CI = 1.22-4.20) and in controls (5A genotype frequency 0.07) as well as HNSCC (5A genotype frequency 0.13, p = 0.03,95%CI = 1.06-3.51) and controls (5A genotype frequency = 0.07) In this study, 5A genotype had greater than two fold risk for developing OSMF (OR = 2.26) and nearly the same in case of HNSCC (OR = 1.94) as compared to controls. In patients with OSMF as well as HNSCC, the ROC analysis between the MMP-3 genotype and age, 6A/6A allele was found to be significant in patients both over and under 45 years of age; while the 5A/5A carrier alleles showed an association only in patients less than 45 years of age.</p> <p>Conclusions</p> <p>This study concluded that the expression of MMP-3 genotype associated with the 5A alleles, it may have an important role in the susceptibility of the patients to develop OSMF and HNSCC.</p
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