219 research outputs found

    A Role for the Vacuolating Cytotoxin, VacA, in Colonization and Helicobacter pylori-Induced Metaplasia in the Stomach

    Get PDF
    Carriage of Helicobacter pylori strains producing more active (s1/i1) forms of VacA is strongly associated with gas-tric adenocarcinoma. To our knowledge, we are the first to determine effects of different polymorphic forms of VacA on inflammation and metaplasia in the mouse stomach. Bacteria producing the less active s2/i2 form of VacA colonized mice more efficiently than mutants null for VacA or producing more active forms of it, providing the first evidence of a positive role for the minimally active s2/i2 toxin. Strains producing more active toxin forms induced more severe and extensive metaplasia and in flammation in the mouse stomach than strains producing weakly active (s2/i2) toxin. We also examined the association in humans, controlling for cag PAI status. In human gastric biopsy specimens, the vacA i1 allele was strongly associated with precancerous intestinal metaplasia, with almost complete absence of intestinal metaplasia in subjects infected with i2-type strains, even in a vacA s1, cagA+ background

    Adenosine Receptors Expression in Human Retina and Choroid with Age-related Macular Degeneration

    Get PDF
    Purpose: Adenosine signaling modulates ocular inflammatory processes, and its antagonism mitigates neovascularization in both newborns and preclinical models of ocular neovascularization including age-related macular degeneration (AMD). The adenosine receptor expression patterns have not been well characterized in the human retina and choroid. Methods: Here we examined the expression of adenosine receptor subtypes within the retina and choroid of human donor eyes with and without AMD. Antibodies specifically targeting adenosine receptor subtypes A1, A2A, A2B, and A3 were used to assess their expression patterns. Quantitative real-time PCR analysis was used to confirm gene expression of these receptors within the normal human retina and choroid. Results: We found that all four receptor subtypes were expressed in several layers of the retina, and within the retinal pigment epithelium and choroid. The expression of A1 receptors was more prominent in the inner and outer plexiform layers, where microglia normally reside, and supported by RNA expression in the retina. A2A and A2B showed similar expression patterns with prominent expression in the vasculature and retinal pigment epithelium. No dramatic differences in expression of these receptors were observed in eyes from patients with dry or wet AMD compared to control, with the exception A3 receptors. Eyes with dry AMD lost expression of A3 in the photoreceptor outer segments compared with eyes from control or wet AMD. Conclusion: The ocular presence of adenosine receptors is consistent with their proposed role in modulation of inflammation in both the retina and choroid, and their potential targeting for AMD treatment

    The utility and feasibility of routine use of a patient-reported outcome measure in paediatric dentistry

    Get PDF
    Within healthcare services, there is increasing emphasis to incorporate patient-reported outcome measures (PROMs), rather than relying solely on clinical outcomes. A 12-item caries-specific measure (CARIES-QC) has been developed and validated for children aged 5–16 years. To date, the routine use of PROMs in paediatric dentistry new patient clinics (NPC) has not been reported. The aim was to conduct a pilot study to assess the feasibility, utility and validity of routine use of a PROM in paediatric dentistry NPC in a UK teaching hospital. Children attending NPC over a four-week period were asked to complete CARIES-QC with an additional free-text box. Interviews were held with members of staff to assess the feasibility of using a PROM routinely. CARIES-QC was completed by 99 children. Almost half of the participants had caries (n = 49, 49.5%). CARIES-QC demonstrated good internal consistency (Cronbach’s alpha = 0.9) and reliability with the global question (r = 0.75, p = 0.01). Clinical staff valued the information provided by the PROM. An electronic delivery method would be beneficial to both clinical and administrative staff. CARIES-QC was able to capture impacts for children with a range of oral conditions. Its use aided treatment planning and future studies should investigate the use of an electronic delivery system to reduce the administrative burden

    Establishment of diagnostic reference levels in cardiac computed tomography

    Get PDF
    The aim of this study was to determine diagnostic reference levels (DRLs) for cardiac computed tomography (CCT) in Jordan. Volume computed tomography dose index (CTDIvol) and dose–length product (DLP) were collected from 228 CCTs performed at seven Jordanian hospitals specialized in cardiac CT. DRLs for cardiac CT were defined at the 75th percentile of CTDIvol and DLP. CTDIvol and DLP were collected from 30 successive cardiac CT in each center except for one center (18 scans). The 75th percentile of the CTDIvol and the DLP of the centers calculated from mixed retrospective and prospective gated modes were 47.74 milligray (mGy) and 1035 mGy/cm, respectively. This study demonstrated wide dose variations among the surveyed hospitals for cardiac CT scans; there was a 5.1-fold difference between the highest and lowest median DLP with a range of 223.2–1146.7 mGy/cm. Differences were associated with variations in the mAs and kVp. This study confirmed large variability in CTDIvol and DLP for cardiac CT scans; variation was associated with acquisition protocols and highlights the need for dose optimization. DRLs are proposed for CCT; there remains substantial potential for optimization of cardiac CT examinations for adults in Jordan

    Comparative analysis of sequence characteristics of imprinted genes in human, mouse, and cattle

    Get PDF
    Genomic imprinting is an epigenetic mechanism that results in monoallelic expression of genes depending on parent-of-origin of the allele. Although the conservation of genomic imprinting among mammalian species has been widely reported for many genes, there is accumulating evidence that some genes escape this conservation. Most known imprinted genes have been identified in the mouse and human, with few imprinted genes reported in cattle. Comparative analysis of genomic imprinting across mammalian species would provide a powerful tool for elucidating the mechanisms regulating the unique expression of imprinted genes. In this study we analyzed the imprinting of 22 genes in human, mouse, and cattle and found that in only 11 was imprinting conserved across the three species. In addition, we analyzed the occurrence of the sequence elements CpG islands, C + G content, tandem repeats, and retrotransposable elements in imprinted and in nonimprinted (control) cattle genes. We found that imprinted genes have a higher G + C content and more CpG islands and tandem repeats. Short interspersed nuclear elements (SINEs) were notably fewer in number in imprinted cattle genes compared to control genes, which is in agreement with previous reports for human and mouse imprinted regions. Long interspersed nuclear elements (LINEs) and long terminal repeats (LTRs) were found to be significantly underrepresented in imprinted genes compared to control genes, contrary to reports on human and mouse. Of considerable significance was the finding of highly conserved tandem repeats in nine of the genes imprinted in all three species

    Evaluation of a new paediatric dentistry intravenous sedation service

    Get PDF
    Introduction: Intravenous sedation (IVS) with propofol offers an alternative to inhalation sedation or general anaesthesia (GA) for dentally anxious young people who require treatment. It offers a greater level of anxiolysis than inhalation sedation and reduced morbidity when compared with GA. Methods: Data were collected prospectively from a convenience sample of children requiring IVS. Participants completed the Children's Experiences of Dental Anxiety Measure (CEDAM) at the start of every visit. Patient demographics, treatment completed, surgery and recovery time were recorded. Feedback was obtained following their first visit. Results: Treatment was successful for 91.5% (43/47) of patients. The average surgery and discharge time was 32.9 (8-105 minutes) and 33.1 (5-84 minutes), respectively. The CEDAM scores were between 14 and 30 (mean score 20.8). Thematic content analysis of the feedback was carried out and themes relating to communication, environment, appointment times, service satisfaction and advice to other patients emerged. Discussion: CEDAM scores may have been lower than expected due to under-reporting by patients or clinicians' perception of higher anxiety levels. Feedback was reviewed regularly and improvements made where possible. Conclusion: The majority of patients successfully received dental treatment under IVS. Changes have been made to the service to improve patient experience and maximise productivity

    Characterization of a Helicobacter pylori strain with high biofilm-forming ability

    Get PDF
    Introduction. Helicobacter pylori is highly polymorphic, and some strains are much more likely to cause disease than others. Biofilm formation can help bacteria to survive antibiotic treatment, immune attack and other stresses, promoting persistent infection. Hypothesis/Gap Statement. We hypothesized that H. pylori isolates from patients with more severe H. pylori-associated disease would be better at forming biofilms than isolates from patients with less severe disease. Aim. We initially aimed to determine whether or not the biofilm-forming ability of H. pylori isolates was associated with disease in the UK-based patients from whom the bacteria were isolated. Methodology. Biofilm-forming ability of H. pylori isolates was determined using a crystal violet assay on glass coverslips. The complete genome sequence of strain 444A was generated by hybrid assembly of Nanopore MinION and Illumina MiSeq data. Results. Although we found no associations between biofilm-forming ability of H. pylori and disease severity in patients, we discovered that strain 444A had particularly high biofilm-forming ability. This strain had been isolated from a patient with gastric ulcer disease and moderate to severe scores for H. pylori-induced histopathology. Analysis of the genome of the high biofilm-forming H. pylori strain 444A revealed that it possesses numerous biofilm- and virulence-associated genes and a small cryptic plasmid encoding a type II toxin–antitoxin system. Conclusion. There is substantial variation in biofilm-forming ability in H. pylori, but this was not significantly associated with disease severity in our study. We identified and characterized an interesting strain with high biofilm-forming ability, including generation and analysis of the complete genome

    SOX9 predicts progression towards cirrhosis in patients while its loss protects against liver fibrosis

    Get PDF
    Fibrosis and organ failure is a common endpoint for many chronic liver diseases. Much is known about the upstream inflammatory mechanisms provoking fibrosis and downstream potential for tissue remodeling. However, less is known about the transcriptional regulation in vivo governing fibrotic matrix deposition by liver myofibroblasts. This gap in understanding has hampered molecular predictions of disease severity and clinical progression and restricted targets for antifibrotic drug development. In this study we show the prevalence of SOX9 in biopsies from patients with chronic liver disease correlated with fibrosis severity and accurately predicted disease progression towards cirrhosis. Inactivation of Sox9 in mice protected against both parenchymal and biliary fibrosis, improved liver function and ameliorated chronic inflammation. SOX9 was downstream of mechanosignaling factor, YAP1. These data demonstrate a role for SOX9 in liver fibrosis and open the way for the transcription factor and its dependent pathways as new diagnostic, prognostic and therapeutic targets in patients with liver fibrosis

    Calpain system protein expression in carcinomas of the pancreas, bile duct and ampulla

    Get PDF
    Background: Pancreatic cancer, including cancer of the ampulla of Vater and bile duct, is very aggressive and has a poor five year survival rate; improved methods of patient stratification are required. Methods: We assessed the expression of calpain-1, calpain-2 and calpastatin in two patient cohorts using immunohistochemistry on tissue microarrays. The first cohort was composed of 68 pancreatic adenocarcinomas and the second cohort was composed of 120 cancers of the bile duct and ampulla. Results: In bile duct and ampullary carcinomas an association was observed between cytoplasmic calpastatin expression and patient age (P = 0.036), and between nuclear calpastatin expression and increased tumour stage (P = 0.026) and the presence of vascular invasion (P = 0.043). In pancreatic cancer, high calpain-2 expression was significantly associated with improved overall survival (P = 0.036), which remained significant in multivariate Cox-regression analysis (hazard ratio = 0.342; 95% confidence interva l = 0.157-0.741; P = 0.007). In cancers of the bile duct and ampulla, low cytoplasmic expression of calpastatin was significantly associated with poor overall survival (P = 0.012), which remained significant in multivariate Cox-regression analysis (hazard ratio = 0.595; 95% confidence interval = 0.365-0.968; P = 0.037). Conclusion: The results suggest that calpain-2 and calpastatin expression is important in pancreatic cancers, influencing disease progression. The findings of this study warrant a larger follow-up study. Keywords: Calpain, Calpastatin, Pancreas, Ampulla, Bile duct, Cance

    The presence of tumour-associated lymphocytes confers a good prognosis in pancreatic ductal adenocarcinoma: an immunohistochemical study of tissue microarrays

    Get PDF
    Background Tumour-associated lymphocytes (TALs) have been linked with good prognosis in several solid tumours. This study aimed to evaluate the prognostic significance of CD3, CD8 and CD20 positive lymphocytes in pancreatic ductal adenocarcinoma. Methods After histological re-evaluation of the tumours of 81 patients who underwent surgical resection for exclusively pancreatic ductal adenocarcinoma, tissue micro-arrays (TMA) were constructed and immunohistochemistry was performed for CD3, CD8 and CD20. The number of lymphocytes within specific tumour compartments (i.e. stromal and intratumoural) was quantified. X-tile software (Yale School of Medicine, CT, USA) was used to stratify patients into 'high’ and 'low’ for each of the lymphocytes stained and their association with survival. Receiver operating curves (ROC) were constructed to evaluate the association between the TALs, alone and in combination, with clinicopathological features. Results CD3 and CD8 positive lymphocytes were associated with grade of tumour differentiation. The presence of intratumoural CD3 positive cells was associated with improved survival (p = 0.028), and intratumoural and stromal CD3 in combination also correlated with improved survival (p = 0.043). When CD20 positive lymphocyte levels were high, survival improved (p = 0.029) and similar results were seen for CD20 in combination with intratumoural CD3 (p = 0.001) and stromal CD8 (p = 0.013). Conclusions This study has shown a correlation between the presence of TALs and survival in pancreatic ductal adenocarcinoma
    corecore