287 research outputs found

    Platelet-derived transforming growth factor-β1 promotes keratinocyte proliferation in cutaneous wound healing.

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    Platelets are a recognised potent source of transforming growth factor-β1 (TGFβ1), a cytokine known to promote wound healing and regeneration by stimulating dermal fibroblast proliferation and extracellular matrix deposition. Platelet lysate has been advocated as a novel personalised therapeutic to treat persistent wounds, although the precise platelet-derived growth factors responsible for these beneficial effects have not been fully elucidated. The aim of this study was to investigate the specific role of platelet-derived TGFβ1 in cutaneous wound healing. Using a transgenic mouse with a targeted deletion of TGFβ1 in megakaryocytes and platelets (TGFβ1fl/fl .PF4-Cre), we show for the first time that platelet-derived TGFβ1 contributes to epidermal and dermal thickening and cellular turnover after excisional skin wounding. In vitro studies demonstrate that human dermal fibroblasts stimulated with platelet lysate containing high levels of platelet-derived TGFβ1 did not exhibit enhanced collagen deposition or proliferation, suggesting that platelet-derived TGFβ1 is not a key promoter of these wound healing processes. Interestingly, human keratinocytes displayed enhanced TGFβ1-driven proliferation in response to platelet lysate, reminiscent of our in vivo findings. In summary, our novel findings define and emphasise an important role of platelet-derived TGFβ1 in epidermal remodelling and regeneration processes during cutaneous wound healing

    A Novel Application of Indocyanine Green Immunofluorescence in Emergent Colorectal Surgery

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    Here, we report on the feasibility of ICG fluorescence imaging to localize lesions in emergent minimally invasive surgery. A 49-year old female presented to the emergency department with a previously unknown malignant bowel obstruction. She was taken emergently to the operating room for a laparoscopic extended right hemicolectomy, based on tumor location from imaging. With intraoperative difficulty localizing the lesion, an on-table colonoscopy was performed. When the tumor was encountered, peritumoral ICG injections were performed, and the fluorescence lymphoscintigraphy was performed intraoperatively in an attempt to visualize the primary tumor laparoscopically. Intraoperative ICG Immunofluorescence allowed precise, real-time localization of the mass in the descending colon. This information changed the course of the operation, as a laparoscopic left hemicolectomy was then performed instead of the planned extended right hemicolectomy. The patient underwent an end-to-end anastomosis without the need for a defunctioning ileostomy. From this case, we demonstrate the use of ICG fluorescence imaging for tumor localization in the emergent setting is safe, feasible, and effective. This information gained from this technology enables real-time decision making, and can even change the operative plan in the emergent setting for the best patient outcomes. What does this paper add to the existing literature? This paper offers a novel application of an emerging technology- ICG fluorescence- that in this capacity allowed precise, real-time localization of a previously unknown mass in the emergent setting, and changed the course of the operation

    Actinomycosis of the sigmoid colon: A case report

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    Abdominal actinomycosis is a chronic suppurative infection caused by Actinomyces species. The ileo-cecal region is most commonly affected, while the left side of the colon is more rarely involved. The infection has a tendency to infiltrate adjacent tissues and is therefore rarely confined to a single organ. Presentation may vary from non specific symptoms and signs to an acute abdomen. A computed tomography scan is helpful in identifying the inflammatory process and the organs involved. It also allows visual guidance for percutaneous drainage of abscesses, thus aiding diagnosis. Culture is difficult because of the anaerobic character and slow growth of actinomycetes. Colonoscopy is usually normal, but may shows signs of external compression. Preoperative diagnosis is rare and is established only in less than 10% of cases. In uncomplicated disease, high dose antibiotic therapy is the mainstay of treatment. Surgery is often performed because of a difficulty in diagnosis. Surgery and antibiotics are required in the case of complicated disease. Combined medical and surgical treatment achieves a cure in about 90% of cases. The authors report a case of sigmoid actinomycosis where diagnosis was made from the histology, and a review of the literature is presented

    Synthesis, and spectroscopic and structural characterization of three new styrylquinoline–benzimidazole hybrids

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    Funding for this research was provided by: Vicerrectoría de Investigación y Extensión of the Industrial University of Santander (grant No. 2680)Three new 4-styryl­quinoline–benzimidazole hybrids have been synthesized using a reaction sequence in which 2-methyl­quinoline precursors first undergo selective oxidation by selenium dioxide to form the corresponding 2-formyl­quinoline inter­mediates, followed by oxidative cyclo­condensation reactions with benzene-1,2-diamine to yield the hybrid products. The formyl inter­mediates and the hybrid products have all been fully characterized using a combination of IR, 1H and 13C NMR spectroscopy, and high-resolution mass spectrometry, and the structures of the three hybrid products have been determined using single-crystal X-ray diffraction. Ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-chloro­styr­yl)quinoline-3-carboxyl­ate, C27H20ClN3O2, (IIIa), and ethyl (E)-2-(1H-ben­zo[d]imidazol-2-yl)-4-(2-meth­oxy­styr­yl)quinoline-3-carboxyl­ate, C28H23N3O3, (IIIb), both crystallize in the solvent-free form with Z′ = 1, but ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-methyl­styr­yl)quinoline-3-carboxyl­ate, C28H23N3O2, (IIIc), crystallizes as a partial hexane solvate with Z′ = 3, and the ester group in one of the independent mol­ecules is disordered over two sets of atomic sites having occupancies of 0.765 (7) and 0.235 (7). The mol­ecules of (IIIc) enclose continuous channels which are occupied by disordered solvent mol­ecules having partial occupancy. In all of the mol­ecules of (IIIa)–(IIIc), the styryl­quinoline fragment is markedly nonplanar. Different combinations of N—H⋯O and C—H⋯π hydrogen bonds generate supra­molecular assemblies which are two-dimensional in (IIIb) and (IIIc), but three-dimensional in (IIIa). Comparisons are made with the structures of some related com­pounds.Publisher PDFPeer reviewe

    Label-free Raman spectroscopic imaging to extract morphological and chemical information from a formalin-fixed, paraffin-embedded rat colon tissue section.

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    Animal models and archived human biobank tissues are useful resources for research in disease development, diagnostics and therapeutics. For the preservation of microscopic anatomical features and to facilitate long-term storage, a majority of tissue samples are denatured by the chemical treatments required for fixation, paraffin embedding and subsequent deparaffinization. These aggressive chemical processes are thought to modify the biochemical composition of the sample and potentially compromise reliable spectroscopic examination useful for the diagnosis or biomarking. As a result, spectroscopy is often conducted on fresh/frozen samples. In this study, we provide an extensive characterization of the biochemical signals remaining in processed samples (formalin fixation and paraffin embedding, FFPE) and especially those originating from the anatomical layers of a healthy rat colon. The application of chemometric analytical methods (unsupervised and supervised) was shown to eliminate the need for tissue staining and easily revealed microscopic features consistent with goblet cells and the dense populations of cells within the mucosa, principally via strong nucleic acid signals. We were also able to identify the collagenous submucosa- and serosa- as well as the muscle-associated signals from the muscular regions and blood vessels. Applying linear regression analysis to the data, we were able to corroborate this initial assignment of cell and tissue types by confirming the biological origin of each layer by reference to a subset of authentic biomolecular standards. Our results demonstrate the potential of using label-free Raman microspectroscopy to obtain superior imaging contrast in FFPE sections when compared directly to conventional haematoxylin and eosin (H&E) staining

    MRI texture analysis parameters of contrast-enhanced T1-weighted images of Crohn's disease differ according to the presence or absence of histological markers of hypoxia and angiogenesis

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    PURPOSE: To investigate if texture analysis parameters of contrast-enhanced MRI differ according to the presence of histological markers of hypoxia and angiogenesis in Crohn's disease (CD). METHODS: Seven CD patients (mean age 38 (19-75), 3 male)) undergoing ileal resection underwent 3T MR enterography including axial ultrafast spoiled gradient-echo T1 post IV gadolinium chelate. Regions of interest were placed in bowel destined for resection and registered to trans-mural histological sections (n = 28 across 7 bowel sections) via MRI of the resected specimen. Microvessel density (MVD) and staining for markers of hypoxia (HIF 1α) and angiogenesis (VEGF) were performed. Texture analysis features were derived utilizing an image filtration-histogram technique at spatial scaling factor (SSF) 0-6 mm, including mean, standard deviation, mean of positive pixels, entropy, kurtosis and skewness and compared according to the presence or absence of histological markers of hypoxia/angiogenesis using Mann-Whitney U/Kruskal-Wallis tests and with the log of MVD using simple linear regression. RESULTS: Mean, standard deviation and mean of positive pixels were significantly lower in sections expressing VEGF. For example at SSF 6 mm, median (inter-quartile range) of mean, standard deviation and mean of positive pixels in those with VEGF expression were 150.1 (134.7), 132.4 (49.2) and 184.0 (91.4) vs. 362.5 (150.2), 216.3 (100.1) and 416.6 (80.0) in those without (p = 0.001, p = 0.004 and p = 0.001), respectively. There was a significant association between skewness and MVD (ratio 1.97 (1.15-3.41)) at SSF = 2 mm. CONCLUSIONS: Contrast-enhanced MRI texture analysis features significantly differ according to the presence or absence of histological markers of hypoxia and angiogenesis in CD

    Recent advances in the detection and management of early gastric cancer and its precursors

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    Despite declines in incidence, gastric cancer remains a disease with a poor prognosis and limited treatment options due to its often late stage of diagnosis. In contrast, early gastric cancer has a good to excellent prognosis, with 5-year survival rates as high as 92.6% after endoscopic resection. There remains an East-West divide for this disease, with high incidence countries such as Japan seeing earlier diagnoses and reduced mortality, in part thanks to the success of a national screening programme. With missed cancers still prevalent at upper endoscopy in the West, and variable approaches to assessment of the high-risk stomach, the quality of endoscopy we provide must be a focus for improvement, with particular attention paid to the minority of patients at increased cancer risk. High-definition endoscopy with virtual chromoendoscopy is superior to white light endoscopy alone. These enhanced imaging modalities allow the experienced endoscopist to accurately and robustly detect high-risk lesions in the stomach. An endoscopy-led staging strategy would mean biopsies could be targeted to histologically confirm the endoscopic impression of premalignant lesions including atrophic gastritis, gastric intestinal metaplasia, dysplasia and early cancer. This approach to quality improvement will reduce missed diagnoses and, combined with the latest endoscopic resection techniques performed at expert centres, will improve early detection and ultimately patient outcomes. In this review, we outline the latest evidence relating to diagnosis, staging and treatment of early gastric cancer and its precursor lesions

    Deep Learning Applied to Raman Spectroscopy for the Detection of Microsatellite Instability/MMR Deficient Colorectal Cancer

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    Defective DNA mismatch repair is one pathogenic pathway to colorectal cancer. It is characterised by microsatellite instability which provides a molecular biomarker for its detection. Clinical guidelines for universal testing of this biomarker are not met due to resource limitations; thus, there is interest in developing novel methods for its detection. Raman spectroscopy (RS) is an analytical tool able to interrogate the molecular vibrations of a sample to provide a unique biochemical fingerprint. The resulting datasets are complex and high-dimensional, making them an ideal candidate for deep learning, though this may be limited by small sample sizes. This study investigates the potential of using RS to distinguish between normal, microsatellite stable (MSS) and microsatellite unstable (MSI-H) adenocarcinoma in human colorectal samples and whether deep learning provides any benefit to this end over traditional machine learning models. A 1D convolutional neural network (CNN) was developed to discriminate between healthy, MSI-H and MSS in human tissue and compared to a principal component analysis-linear discriminant analysis (PCA-LDA) and a support vector machine (SVM) model. A nested cross-validation strategy was used to train 30 samples, 10 from each group, with a total of 1490 Raman spectra. The CNN achieved a sensitivity and specificity of 83% and 45% compared to PCA-LDA, which achieved a sensitivity and specificity of 82% and 51%, respectively. These are competitive with existing guidelines, despite the low sample size, speaking to the molecular discriminative power of RS combined with deep learning. A number of biochemical antecedents responsible for this discrimination are also explored, with Raman peaks associated with nucleic acids and collagen being implicated

    Diffusion-weighted imaging for evaluating inflammatory activity in Crohn's disease: comparison with histopathology, conventional MRI activity scores, and faecal calprotectin

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    PURPOSE: To evaluate whether the extent of enteric diffusion-weighted imaging (DWI) signal abnormality reflects inflammatory burden in Crohn's disease (CD), and to compare qualitative and quantitative grading. METHODS: 69 CD patients (35 male, age 16-78) undergoing MR enterography with DWI (MRE-D) and the same-day faecal calprotectin (cohort 1) were supplemented by 29 patients (19 male, age 16-70) undergoing MRE-D and terminal ileal biopsy (cohort 2). Global (cohort 1) and terminal ileal (cohort 2) DWI signal was graded (0 to 3) by 2 radiologists and segmental apparent diffusion coefficient (ADC) calculated. Data were compared to calprotectin and a validated MRI activity score [MEGS] (cohort 1), and a histopathological activity score (eAIS) (cohort 2) using nonparametric testing and rank correlation. RESULTS: Patients with normal (grades 0 and 1) DWI signal had lower calprotectin and MEGS than those with abnormal signal (grades 2 and 3) (160 vs. 492 μg/l, p = 0.0004, and 3.3 vs. 21, p  120 μg/l) were 83% and 52%, respectively. There was a negative correlation between ileal MEGS and ADC (r = -0.41, p = 0.017). There was no significant difference in eAIS between qualitative DWI scores (p = 0.42). Mean ADC was not different in those with and without histological inflammation (2077 vs. 1622 × 10(-6)mm(2)/s, p = 0.10) CONCLUSIONS: Qualitative grading of DWI signal has utility in defining the burden of CD activity. Quantitative ADC measurements have poor discriminatory ability for segmental disease activity

    Accuracy of endoscopic staging and targeted biopsies for routine gastric intestinal metaplasia and gastric atrophy evaluation study protocol of a prospective, cohort study: the estimate study

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    Introduction Patients with chronic atrophic gastritis (CAG) and intestinal metaplasia (IM) are at risk of developing gastric adenocarcinoma. Their diagnosis and management currently rely on histopathological guidance after random endoscopic biopsy sampling (Sydney biopsy strategy). This approach has significant flaws such as under-diagnosis, poor reproducibility and poor correlation between endoscopy and histology. This prospective, international multicentre study aims to establish whether endoscopyled risk stratification accurately and reproducibly predicts CAG and IM extent and disease stage. Methods and analysis Patients with CAG and/or IM on standard white light endoscopy (WLE) will be prospectively identified and invited to undergo a second endoscopy performed by an expert endoscopist using enhanced endoscopic imaging techniques with virtual chromoendoscopy. Extent of CAG/IM will be endoscopically staged with enhanced imaging and compared with standard WLE. Histopathological risk stratification through targeted biopsies will be compared with endoscopic disease staging and to random biopsy staging on WLE as a reference. At least 234 patients are required to show a 10% difference in sensitivity and accuracy between enhanced imaging endoscopy-led staging and the current biopsy-led staging protocol of gastric atrophy with a power (beta) of 80% and a 0.05 probability of a type I error (alpha). Ethics and dissemination The study was approved by the respective Institutional Review Boards (Netherlands: MEC2018-078; UK: 19/LO/0089). The findings will be published in peer-reviewed journals and presented at scientific meetings
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