1,286 research outputs found
Benign versus malignant hepatic nodules: MR imaging findings with pathologic correlation
According to the currently used nomenclature, there are only two types of
hepatocellular nodular lesions: regenerative lesions and dysplastic or
neoplastic lesions. Regenerative nodules include monoacinar regenerative
nodules, multiacinar regenerative nodules, cirrhotic nodules, segmental or
lobar hyperplasia, and focal nodular hyperplasia. Dysplastic or neoplastic
nodules include hepatocellular adenoma, dysplastic foci, dysplastic
nodules, and hepatocellular carcinoma (HCC). Many of these types of
hepatic nodules play a role in the de novo and stepwise carcinogenesis of
HCC, which comprises the following steps: regenerative nodule, low-grade
dysplastic nodule, high-grade dysplastic nodule, small HCC, and large HCC.
State-of-the-art magnetic resonance (MR) imaging facilitates detection and
characterization in most cases of hepatic nodules. State-of-the-art MR
imaging includes single-shot fast spin-echo imaging, in-phase and
opposed-phase T1-weighted gradient-echo imaging, T2-weighted fast
spin-echo imaging with fat saturation, and two-dimensional or
three-dimensional dynamic multiphase contrast material-enhanced imaging
The microaerophilic microbiota of de-novo paediatric inflammatory bowel disease: the BISCUIT study
<p>Introduction: Children presenting for the first time with inflammatory bowel disease (IBD) offer a unique opportunity to study aetiological agents before the confounders of treatment. Microaerophilic bacteria can exploit the ecological niche of the intestinal epithelium; Helicobacter and Campylobacter are previously implicated in IBD pathogenesis. We set out to study these and other microaerophilic bacteria in de-novo paediatric IBD.</p>
<p>Patients and Methods: 100 children undergoing colonoscopy were recruited including 44 treatment naïve de-novo IBD patients and 42 with normal colons. Colonic biopsies were subjected to microaerophilic culture with Gram-negative isolates then identified by sequencing. Biopsies were also PCR screened for the specific microaerophilic bacterial groups: Helicobacteraceae, Campylobacteraceae and Sutterella wadsworthensis.</p>
<p>Results: 129 Gram-negative microaerophilic bacterial isolates were identified from 10 genera. The most frequently cultured was S. wadsworthensis (32 distinct isolates). Unusual Campylobacter were isolated from 8 subjects (including 3 C. concisus, 1 C. curvus, 1 C. lari, 1 C. rectus, 3 C. showae). No Helicobacter were cultured. When comparing IBD vs. normal colon control by PCR the prevalence figures were not significantly different (Helicobacter 11% vs. 12%, p = 1.00; Campylobacter 75% vs. 76%, p = 1.00; S. wadsworthensis 82% vs. 71%, p = 0.312).</p>
<p>Conclusions: This study offers a comprehensive overview of the microaerophilic microbiota of the paediatric colon including at IBD onset. Campylobacter appear to be surprisingly common, are not more strongly associated with IBD and can be isolated from around 8% of paediatric colonic biopsies. S. wadsworthensis appears to be a common commensal. Helicobacter species are relatively rare in the paediatric colon.</p>
Multi-omics of the esophageal microenvironment identifies signatures associated with progression of Barrett’s esophagus
Background: The enrichment of Gram-negative bacteria of oral origin in the esophageal microbiome has been associated with the development of metaplasia. However, to date, no study has comprehensively assessed the relationships between the esophageal microbiome and the host. Methods: Here, we examine the esophageal microenvironment in gastro-esophageal reflux disease and metaplasia using multi-omics strategies targeting the microbiome and host transcriptome, followed by targeted culture, comparative genomics, and host-microbial interaction studies of bacterial signatures of interest. Results: Profiling of the host transcriptome from esophageal mucosal biopsies revealed profound changes during metaplasia. Importantly, five biomarkers showed consistent longitudinal changes with disease progression from reflux disease to metaplasia. We showed for the first time that the esophageal microbiome is distinct from the salivary microbiome and the enrichment of Campylobacter species as a consistent signature in disease across two independent cohorts. Shape fitting and matrix correlation identified associations between the microbiome and host transcriptome profiles, with a novel co-exclusion relationship found between Campylobacter and napsin B aspartic peptidase. Targeted culture of Campylobacter species from the same cohort revealed a subset of isolates to have a higher capacity to survive within primary human macrophages. Comparative genomic analyses showed these isolates could be differentiated by specific genomic features, one of which was validated to be associated with intracellular fitness. Screening for these Campylobacter strain-specific signatures in shotgun metagenomics data from another cohort showed an increase in prevalence with disease progression. Comparative transcriptomic analyses of primary esophageal epithelial cells exposed to the Campylobacter isolates revealed expression changes within those infected with strains with high intracellular fitness that could explain the increased likelihood of disease progression. Conclusions: We provide a comprehensive assessment of the esophageal microenvironment, identifying bacterial strain-specific signatures with high relevance to progression of metaplasia
Mothers' Preferences and Willingness to Pay for Human Papillomavirus Vaccination for Their Daughters: A Discrete Choice Experiment in Hong Kong
OBJECTIVES:
To determine the preference of mothers in Hong Kong and their willingness to pay (WTP) for human papillomavirus (HPV) vaccination for their daughters.
METHODS:
A discrete choice experiment survey with a two-alternative study design was developed. Data were collected from pediatric specialist outpatient clinics from 482 mothers with daughters aged between 8 and 17 years. Preferences of the four attributes of HPV vaccines (protection against cervical cancer, protection duration, side effects, and out-of-pocket costs) were evaluated. The marginal and overall WTP were estimated using multinomial logistic regression. A subgroup analysis was conducted to explore the impact of socioeconomic factors on mothers’ WTP.
RESULTS:
Side effects, protection against cervical cancer, protection duration, and out-of-pocket cost determined the decision to receive or not receive the vaccine. All attributes had a statistically significant effect on the preference of and the WTP for the vaccine. Maximum WTP for ideal vaccines (i.e., 100% protection, lifetime protection duration, and 0% side effects) was HK1129). The estimated WTP for vaccines currently available was HK208), lower than the current market price. Among those who had a monthly household income of more than HK12,821), the WTP for vaccines currently offered was higher than the market price.
CONCLUSION:
This study provides new data on how features of the HPV vaccine are viewed and valued by mothers by determining their perception of ideal or improved and current vaccine technologies. These findings could contribute to future policies on the improvement of HPV vaccine and be useful for the immunization service in Hong Kong
Identification of microRNA 885-5p as a novel regulator of tumor metastasis by targeting CPEB2 in colorectal cancer
published_or_final_versio
Nonequilibrium Dynamics in Noncommutative Spacetime
We study the effects of spacetime noncommutativity on the nonequilibrium
dynamics of particles in a thermal bath. We show that the noncommutative
thermal bath does not suffer from any further IR/UV mixing problem in the sense
that all the finite-temperature non-planar quantities are free from infrared
singularities. We also point out that the combined effect of finite temperature
and noncommutative geometry has a distinct effect on the nonequilibrium
dynamics of particles propagating in a thermal bath: depending on the momentum
of the mode of concern, noncommutative geometry may switch on or switch off
their decay and thermalization. This momentum dependent alternation of the
decay and thermalization rates could have significant impacts on the
nonequilibrium phenomena in the early universe at which spacetime
noncommutativity may be present. Our results suggest a re-examination of some
of the important processes in the early universe such as reheating after
inflation, baryogenesis and the freeze-out of superheavy dark matter
candidates.Comment: 24 pages, 2 figure
Intestinal Microbiota Shifts towards Elevated Commensal Escherichia coli Loads Abrogate Colonization Resistance against Campylobacter jejuni in Mice
Background: The zoonotic pathogen Campylobacter jejuni is a leading cause of bacterial foodborne enterocolitis in humans worldwide. The understanding of immunopathology underlying human campylobacteriosis is hampered by the fact that mice display strong colonization resistance against the pathogen due to their host specific gut microbiota composition. Methodology/Principal Findings: Since the microbiota composition changes significantly during intestinal inflammation we dissected factors contributing to colonization resistance against C. jejuni in murine ileitis, colitis and in infant mice. In contrast to healthy animals C. jejuni could stably colonize mice suffering from intestinal inflammation. Strikingly, in mice with Toxoplasma gondii-induced acute ileitis, C. jejuni disseminated to mesenteric lymphnodes, spleen, liver, kidney, and blood. In infant mice C. jejuni infection induced enterocolitis. Mice suffering from intestinal inflammation and C. jejuni susceptible infant mice displayed characteristical microbiota shifts dominated by increased numbers of commensal Escherichia coli. To further dissect the pivotal role of those distinct microbiota shifts in abrogating colonization resistance, we investigated C. jejuni infection in healthy adult mice in which the microbiota was artificially modified by feeding live commensal E. coli. Strikingly, in animals harboring supra-physiological intestinal E. coli loads, colonization resistance was significantly diminished and C. jejuni infection induced enterocolitis mimicking key features of human campylobacteriosis. Conclusion/Significance: Murine colonization resistance against C. jejuni is abrogated by changes in the microbiot
Peak exercise capacity estimated from incremental shuttle walking test in patients with COPD: a methodological study
BACKGROUND: In patients with COPD, both laboratory exercise tests and field walking tests are used to assess physical performance. In laboratory tests, peak exercise capacity in watts (W peak) and/or peak oxygen uptake (VO(2 )peak) are assessed, whereas the performance on walking tests usually is expressed as distance walked. The aim of the study was to investigate the relationship between an incremental shuttle walking test (ISWT) and two laboratory cycle tests in order to assess whether W peak could be estimated from an ISWT. METHODS: Ninety-three patients with moderate or severe COPD performed an ISWT, an incremental cycle test (ICT) to measure W peak and a semi-steady-state cycle test with breath-by-breath gas exchange analysis (CPET) to measure VO(2 )peak. Routine equations for conversion between cycle tests were used to estimate W peak from measured VO(2 )peak (CPET). Conversion equation for estimation of W peak from ISWT was found by univariate regression. RESULTS: There was a significant correlation between W peak and distance walked on ISWT × body weight (r = 0.88, p < 0.0001). The agreement between W peak measured by ICT and estimated from ISWT was similar to the agreement between measured W peak (ICT) and W peak estimated from measured VO(2 )peak by CPET. CONCLUSION: Peak exercise capacity measured by an incremental cycle test could be estimated from an ISWT with similar accuracy as when estimated from peak oxygen uptake in patients with COPD
Incidence of genital warts among the Hong Kong general adult population
<p>Abstract</p> <p>Background</p> <p>The objective of this study is to estimate the incidence of genital warts in Hong Kong and explore a way to establish a surveillance system for genital warts among the Hong Kong general population.</p> <p>Methods</p> <p>A total of 170 private doctors and all doctors working in the 5 local Social Hygiene Clinics (SHC) participated in this study. During the 14-day data collection period (January 5 through18, 2009), the participating doctors filled out a log-form on a daily basis to record the number of patients with genital warts. The total number of new cases of genital warts presented to private and public doctors in Hong Kong was projected using the stratification sampling method.</p> <p>Results</p> <p>A total of 721 (0.94%) adults presented with genital warts to the participating doctors during the two-week study period, amongst them 73 (10.1%) were new cases. The projected number of new cases of genital warts among Hong Kong adults was 442 (297 male and 144 female) during the study period. The incidence of genital warts in Hong Kong was estimated to be 203.7 per 100,000 person-years (respectively 292.2 and 124.9 per 100,000 person-years for males and females).</p> <p>Conclusions</p> <p>The incidence of genital warts is high among adults in Hong Kong. The study demonstrates the importance of collecting surveillance data from both private and public sectors.</p
Consumer perceptions of co-branding alliances: Organizational dissimilarity signals and brand fit
This study explores how consumers evaluate co-branding alliances between dissimilar partner firms. Customers are well aware that different firms are behind a co-branded product and observe the partner firms’ characteristics. Drawing on signaling theory, we assert that consumers use organizational characteristics as signals in their assessment of brand fit and for their purchasing decisions. Some organizational signals are beyond the control of the co-branding partners or at least they cannot alter them on short notice. We use a quasi-experimental design and test how co-branding partner dissimilarity affects brand fit perception. The results show that co-branding partner dissimilarity in terms of firm size, industry scope, and country-of-origin image negatively affects brand fit perception. Firm age dissimilarity does not exert significant influence. Because brand fit generally fosters a benevolent consumer attitude towards a co-branding alliance, the findings suggest that high partner dissimilarity may reduce overall co-branding alliance performance
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