The human T-lymphotropic viruses (HTLVs) types 1 and 2 originated independently and are related to distinct lineages of simian T-lymphotropic viruses (STLV-1 and STLV-2, respectively). These facts, along with the finding that HTLV-1 diversity appears to have resulted from multiple cross-species transmissions of STLV-1, suggest that contact between humans and infected nonhuman primates (NHPs) may result in HTLV emergence. We investigated the diversity of HTLV among central Africans reporting contact with NHP blood and body fluids through hunting, butchering, and keeping primate pets. We show that this population is infected with a wide variety of HTLVs, including two previously unknown retroviruses: HTLV-4 is a member of a phylogenetic lineage that is distinct from all known HTLVs and STLVs; HTLV-3 falls within the phylogenetic diversity of STLV-3, a group not previously seen in humans. We also document human infection with multiple STLV-1-like viruses. These results demonstrate greater HTLV diversity than previously recognized and suggest that NHP exposure contributes to HTLV emergence. Our discovery of unique and divergent HTLVs has implications for HTLV diagnosis, blood screening, and potential disease development in infected persons. The findings also indicate that cross-species transmission is not the ratelimiting step in pandemic retrovirus emergence and suggest that it may be possible to predict and prevent disease emergence by surveillance of populations exposed to animal reservoirs and interventions to decrease risk factors, such as primate hunting.retrovirus ͉ zoonosis ͉ simian ͉ exposures ͉ diversity
Cross-species transmission of retroviruses is common in Cameroon. To determine risk for simian T-cell lymphotropic virus (STLV) transmission from nonhuman primates to hunters, we examined 170 hunter-collected dried blood spots (DBS) from 12 species for STLV. PCR with generic tax and group-specifi c long terminal repeat primers showed that 12 (7%) specimens from 4 nonhuman primate species were infected with STLV. Phylogenetic analyses showed broad diversity of STLV, including novel STLV-1 and STLV-3 sequences and a highly divergent STLV-3 subtype found in Cercopithecus mona and C. nictitans monkeys. Screening of peripheral blood mononuclear cell DNA from 63 HTLVseroreactive, PCR-negative hunters did not identify human infections with this divergent STLV-3. Therefore, huntercollected DBS can effectively capture STLV diversity at the point where pathogen spillover occurs. Broad screening using this relatively easy collection strategy has potential for large-scale monitoring of retrovirus cross-species transmission among highly exposed human populations.
Graphite materials were prepared from two Spanish anthracites, AF and ATO, by heating at
different temperatures within the range 2000−2800 °C. XRD and Raman spectroscopy were
employed to characterize the degrees of crystallinity and crystal orientation of the materials. In
addition to studying the evolution of typical crystal parameters such as interlayer spacing, d
002,
and crystallite sizes, L
a
and L
c
, with temperature, this work aimed to evaluate the influence of
elemental composition, texture (as measured by optical microscopy), and mineral matter of the
raw anthracites on their ability to graphitize. Two temperature segments were discerned during
the development of crystallinity. The first segment exhibited major improvements in crystal
parameters, which afterward reached a plateau value. Raman parameters indicated that further
improvement in crystal orientation could be obtained after heating at the highest temperature
(2800 °C). The limiting temperature at which the materials showed their highest degree of
structural order, i.e., the temperature at which the plateau was reached, was lower for the most
graphitizable anthracite (AF). This anthracite was found to have higher hydrogen and mineral
matter (specifically Al, Fe, K, and Si) contents. However, the textural anisotropy of this most
graphitizable anthracite was lower than that of the other anthracite under study (ATO). Optical
microscopy characterization of the carbonized materials showed that this trend changed after
heating the anthracites at 1000 °C, i.e., the anisotropy of the texture in the carbonized AF was
higher than that of the corresponding carbonized material prepared from ATO. It was concluded
that the structural and textural changes of the anthracites during carbonization, which are related
with both their microtexture and hydrogen content, influence the graphitization process.
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