5 research outputs found
Detection of Helicobacter pylori in bile of cats
Lymphocytic cholangitis (LC) in cats is a biliary disease of unknown etiology. Helicobacter spp. were recently implicated in human primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). Because of the similarities between PSC/PBC with LC, we hypothesized that Helicobacter spp. are involved in feline LC. A PCR with Helicobacter genus-specific 16S rRNA primers was performed on DNA isolated from feline bile samples. Four of the 15 (26%) LC samples were positive, whereas only 8/51 (16%) of non-LC samples were PCR positive (p=0.44). Sequence analysis of the amplicons revealed a 100% identity with the Helicobacter pylori specific DNA fragments. Our data suggest an etiological role of H. pylori in feline LC and that cats are a potential zoonotic reservoir
The presence of the cag pathogenicity island is associated with increased superoxide anion radical scavenging activity by Helicobacter pylori
Reactive oxygen species (ROS) generated by Helicobacter pylori infection have been suggested to be important factors in induction of gastric malignancies. Utilizing electron spin resonance spectrometry, H. pylori-dependent radical formation and hydroxyl- and superoxide-anion radical scavenging activity was investigated. In contrast to previous reports, we found that H. pylori does not produce ROS, but displays superoxide scavenging activity. This scavenging activity was increased in cag-positive H. pylori strains when compared to strains lacking an intact cag pathogenicity island, and was dependent on enzyme activity. We hypothesize that the increased scavenging activity of cag-positive H. pylori strains is an adaptation to the increased inflammatory response associated with the cag-positive genotype of H. pylori
Neurofilament Light Chain Elevation and Disability Progression in Multiple Sclerosis.
IMPORTANCE
Mechanisms contributing to disability accumulation in multiple sclerosis (MS) are poorly understood. Blood neurofilament light chain (NfL) level, a marker of neuroaxonal injury, correlates robustly with disease activity in people with MS (MS); however, data on the association between NfL level and disability accumulation have been conflicting.
OBJECTIVE
To determine whether and when NfL levels are elevated in the context of confirmed disability worsening (CDW).
DESIGN, SETTING, AND PARTICIPANTS
This study included 2 observational cohorts: results from the Expression, Proteomics, Imaging, Clinical (EPIC) study at the University of California San Francisco (since 2004) were confirmed in the Swiss Multiple Sclerosis Cohort (SMSC), a multicenter study in 8 centers since 2012. Data were extracted from EPIC in April 2022 (sampling July 1, 2004, to December 20, 2016) and SMSC in December 2022 (sampling June 6, 2012, to September 2, 2021). The study included 2 observational cohorts in tertiary MS centers. All participants of both cohorts with available NfL results were included in the study, and no eligible participants were excluded or declined to participate.
EXPOSURE
Association between NfL z scores and CDW.
MAIN OUTCOME MEASURES
CDW was defined as Expanded Disability Status Scale (EDSS) worsening that was confirmed after 6 or more months and classified into CDW associated with clinical relapses (CDW-R) or independent of clinical relapses (CDW-NR). Visits were classified in relation to the disability worsening events into CDW(-2) for 2 visits preceding event, CDW(-1) for directly preceding event, CDW(event) for first diagnosis of EDSS increase, and the confirmation visit. Mixed linear and Cox regression models were used to evaluate NfL dynamics and to assess the association of NfL with future CDW, respectively.
RESULTS
A total of 3906 EPIC visits (609 participants; median [IQR] age, 42.0 [35.0-50.0] years; 424 female [69.6%]) and 8901 SMSC visits (1290 participants; median [IQR] age, 41.2 [32.5-49.9] years; 850 female [65.9%]) were included. In CDW-R (EPIC, 36 events; SMSC, 93 events), NfL z scores were 0.71 (95% CI, 0.35-1.07; Pâ<â.001) units higher at CDW-R(-1) in EPIC and 0.32 (95% CI, 0.14-0.49; Pâ<â.001) in SMSC compared with stable MS samples. NfL elevation could be detected preceding CDW-NR (EPIC,â191 events; SMSC, 342 events) at CDW-NR(-2) (EPIC: 0.23; 95% CI, 0.01-0.45; Pâ=â.04; SMSC: 0.28; 95% CI, 0.18-0.37; Pâ<â.001) and at CDW-NR(-1) (EPIC: 0.27; 95% CI, 0.11-0.44; Pâ<â.001; SMSC: 0.09; 95% CI, 0-0.18; P = .06). Those findings were replicated in the subgroup with relapsing-remitting MS. Time-to-event analysis confirmed the association between NfL levels and future CDW-R withinâapproximately 1 year and CDW-NR (inâapproximatelyâ1-2 years).
CONCLUSIONS AND RELEVANCE
This cohort study documents the occurrence of NfL elevation in advance of clinical worsening and may hint to a potential window of ongoing dynamic central nervous system pathology that precedes the diagnosis of CDW
Mapping subnational HIV mortality in six Latin American countries with incomplete vital registration systems
Background
Human immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico.
Methods
We performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017.
Results
All countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countriesâapart from Ecuadorâacross the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50% or more HIV deaths were concentrated in fewer than 10% of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groupsâthe median age group among decedents ranged from 30 to 45âyears of age at the municipality level in Brazil, Colombia, and Mexico in 2017.
Conclusions
Our subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths