696 research outputs found
A new type of anti-ganglioside antibodies present in neurological patients
AbstractHigh titers of anti-GA1 antibodies have been associated with neurological syndromes. In most cases, these antibodies cross-react with the structurally related glycolipids GM1 and GD1b, although specific anti-GA1 antibodies have also been reported. The role of specific anti-GA1 antibodies is uncertain since the presence of GA1 in the human nervous system has not been clarified. A rabbit was immunized with GD1a and its sera were screened for antibody reactivity by standard immunoassay methods (HPTLC-immunostaining and ELISA). Anti-GD1a antibodies were not detected but, unexpectedly, anti-GA1 IgG-antibodies were found. Antibody binding to GA1 was inhibited by soluble GA1 but also by GD1a. These results indicate that the rabbit produced antibodies that recognize epitopes present on the glycolipids, that are absent or not exposed on solid phase adsorbed GD1a. We investigated the presence of these unusual anti-ganglioside antibodies in normal and neurological patient sera. Approximately, 10% of normal human sera contained low titer of specific anti-GA1 IgG-antibodies but none of them recognized soluble GD1a. High titers of IgG-antibodies reacting only with GA1 were detected in 12 patient sera out of 325 analyzed. Of these, 6 sera showed binding that was inhibited by soluble GD1a and four of them also by GM1. This new type of anti-ganglioside antibodies should be considered important elements for understanding of the pathogenesis of these diseases as well as their diagnosis
HĂĄbitos alimentarios de las familias que pertenecen al programa de complementaciĂłn alimentaria, desayunos infantiles ManĂĄ con amor.
El departamento de Antioquia presenta una grave problemĂĄtica de seguridad alimentaria con las mĂĄs altas tasas de mortalidad infantil por desnutriciĂłn. El objetivo de esta investigaciĂłn es identificar los hĂĄbitos alimentarios de la poblaciĂłn del Bajo Cauca que pertenecen al programa MANĂ Infantil C
Fluoride Content in Foods and Beverages From Mexico City Markets and Supermarkets
Background:
Sources of fluoride exposure for Mexicans include foods, beverages, fluoridated salt, and naturally fluoridated water. There are no available data describing fluoride content of foods and beverages consumed in Mexico.
Objective:
To measure the content of fluoride in foods and beverages typically consumed and to compare their content to that of those from the United States and the United Kingdom.
Methods:
Foods and beverages reported as part of the Mexican Health and Nutrition Survey (n = 182) were purchased in the largest supermarket chains and local markets in Mexico City. Samples were analyzed for fluoride, at least in duplicate, using a modification of the hexamethyldisiloxane microdiffusion method. Value contents were compared to those from the US Department of Agriculture and UK fluoride content tables.
Results:
The food groups with the lowest and highest fluoride content were eggs (2.32 ”g/100 g) and seafood (371 ”g/100 g), respectively. When estimating the amount of fluoride per portion size, the lowest content corresponded to eggs and the highest to fast foods. Meats and sausages, cereals, fast food, sweets and cakes, fruits, dairy products, legumes, and seafood from Mexico presented higher fluoride contents than similar foods from the United States or the United Kingdom. Drinks and eggs from the United States exhibited the highest contents, while this was the case for pasta, soups, and vegetables from the United Kingdom.
Conclusion:
The majority of items analyzed contained higher fluoride contents than their US and UK counterparts. Data generated provide the first and largest table on fluoride content, which will be useful for future comparisons and estimations
Ferret badger rabies origin and its revisited importance as potential source of rabies transmission in Southeast China
<p>Abstract</p> <p>Background</p> <p>The frequent occurrence of ferret badger-associated human rabies cases in southeast China highlights the lack of laboratory-based surveillance and urges revisiting the potential importance of this animal in rabies transmission. To determine if the ferret badgers actually contribute to human and dog rabies cases, and the possible origin of the ferret badger-associated rabies in the region, an active rabies survey was conducted to determine the frequency of rabies infection and seroprevalence in dogs and ferret badgers.</p> <p>Methods</p> <p>A retrospective survey on rabies epidemics was performed in Zhejiang, Jiangxi and Anhui provinces in southeast China. The brain tissues from ferret badgers and dogs were assayed by fluorescent antibody test. Rabies virus was isolated and sequenced for phylogenetic analysis. The sera from ferret badgers and dogs were titrated using rabies virus neutralizing antibodies (VNA) test.</p> <p>Results</p> <p>The ferret badgers presented a higher percentage of rabies seroconversion than dogs did in the endemic region, reaching a maximum of 95% in the collected samples. Nine ferret badger-associated rabies viruses were isolated, sequenced, and were phylogenetically clustered as a separate group. Nucleotide sequence revealed 99.4-99.8% homology within the ferret badger isolates, and 83-89% homology to the dog isolates in the nucleoprotein and glycoprotein genes in the same rabies endemic regions.</p> <p>Conclusions</p> <p>Our data suggest ferret badger-associated rabies has likely formed as an independent enzootic originating from dogs during the long-term rabies infestation in southeast China. The eventual role of FB rabies in public health remains unclear. However, management of ferret badger bites, rabies awareness and control in the related regions should be an immediate need.</p
Human Rabies and Rabies in Vampire and Nonvampire Bat Species, Southeastern Peru, 2007
After a human rabies outbreak in southeastern Peru, we collected bats to estimate the prevalence of rabies in various species. Among 165 bats from 6 genera and 10 species, 10.3% were antibody positive; antibody prevalence was similar in vampire and nonvampire bats. Thus, nonvampire bats may also be a source for human rabies in Peru
Detection of North American orthopoxviruses by real time-PCR
The prevalence of North American orthopoxviruses in nature is unknown and may be more difficult to ascertain due to wide spread use of vaccinia virus recombinant vaccines in the wild. A real time PCR assay was developed to allow for highly sensitive and specific detection of North American orthopoxvirus DNA in animal tissues and bodily fluids. This method is based on the amplification of a 156 bp sequence within a myristylated protein, highly conserved within the North American orthopoxviruses but distinct from orthologous genes present in other orthopoxviruses. The analytical sensitivity was 1.1 fg for Volepox virus DNA, 1.99 fg for Skunkpox virus DNA, and 6.4 fg for Raccoonpox virus DNA with a 95% confidence interval. Our assay did not cross-react with other orthopoxviruses or ten diverse representatives of the Chordopoxvirinae subfamily. This new assay showed more sensitivity than tissue culture tests, and was capable of differentiating North American orthopoxviruses from other members of Orthopoxvirus. Thus, our assay is a promising tool for highly sensitive and specific detection of North American orthopoxviruses in the United States and abroad
Rates of Viral Evolution Are Linked to Host Geography in Bat Rabies
Rates of evolution span orders of magnitude among RNA viruses with important implications for viral transmission and emergence. Although the tempo of viral evolution is often ascribed to viral features such as mutation rates and transmission mode, these factors alone cannot explain variation among closely related viruses, where host biology might operate more strongly on viral evolution. Here, we analyzed sequence data from hundreds of rabies viruses collected from bats throughout the Americas to describe dramatic variation in the speed of rabies virus evolution when circulating in ecologically distinct reservoir species. Integration of ecological and genetic data through a comparative Bayesian analysis revealed that viral evolutionary rates were labile following historical jumps between bat species and nearly four times faster in tropical and subtropical bats compared to temperate species. The association between geography and viral evolution could not be explained by host metabolism, phylogeny or variable selection pressures, and instead appeared to be a consequence of reduced seasonality in bat activity and virus transmission associated with climate. Our results demonstrate a key role for host ecology in shaping the tempo of evolution in multi-host viruses and highlight the power of comparative phylogenetic methods to identify the host and environmental features that influence transmission dynamics
A degenerate primer MOB typing (DPMT) method to classify gamma-proteobacterial plasmids in clinical and environmental settings
Transmissible plasmids are responsible for the spread of genetic determinants, such as antibiotic resistance or virulence traits, causing a large ecological and epidemiological impact. Transmissible plasmids, either conjugative or mobilizable, have in common the presence of a relaxase gene. Relaxases were previously classified in six protein families according to their phylogeny. Degenerate primers hybridizing to coding sequences of conserved amino acid motifs were designed to amplify related relaxase genes from Îł-Proteobacterial plasmids. Specificity and sensitivity of a selected set of 19 primer pairs were first tested using a collection of 33 reference relaxases, representing the diversity of Îł-Proteobacterial plasmids. The validated set was then applied to the analysis of two plasmid collections obtained from clinical isolates. The relaxase screening method, which we call "Degenerate Primer MOB Typing" or DPMT, detected not only most known Inc/Rep groups, but also a plethora of plasmids not previously assigned to any Inc group or Rep-type
Virgo Detector Characterization and Data Quality during the O3 run
The Advanced Virgo detector has contributed with its data to the rapid growth
of the number of detected gravitational-wave signals in the past few years,
alongside the two LIGO instruments. First, during the last month of the
Observation Run 2 (O2) in August 2017 (with, most notably, the compact binary
mergers GW170814 and GW170817) and then during the full Observation Run 3 (O3):
an 11 months data taking period, between April 2019 and March 2020, that led to
the addition of about 80 events to the catalog of transient gravitational-wave
sources maintained by LIGO, Virgo and KAGRA. These discoveries and the manifold
exploitation of the detected waveforms require an accurate characterization of
the quality of the data, such as continuous study and monitoring of the
detector noise. These activities, collectively named {\em detector
characterization} or {\em DetChar}, span the whole workflow of the Virgo data,
from the instrument front-end to the final analysis. They are described in
details in the following article, with a focus on the associated tools, the
results achieved by the Virgo DetChar group during the O3 run and the main
prospects for future data-taking periods with an improved detector.Comment: 86 pages, 33 figures. This paper has been divided into two articles
which supercede it and have been posted to arXiv on October 2022. Please use
these new preprints as references: arXiv:2210.15634 (tools and methods) and
arXiv:2210.15633 (results from the O3 run
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