302 research outputs found
Simian immunodeficiency virus (SIV) molecular epidemiology in non-human primates from West Africa
No full textIt is now scientifically proved that the human immunodeficiency viruses, HIV-1
and HIV-2, are the results of cross-species transmissions of the simian
immunodeficiency viruses (SIV) that naturally infect non-human primates in sub-
Saharan Africa. SIVsmm from sooty mangabeys (Cercocebus atys atys) is recognised
as the progenitor of HIV-2, whereas SIVcpz from chimpanzees (Pan troglodytes
troglodytes) and SIVgor from gorillas (Gorilla gorilla gorilla) in West-central Africa are
the ancestors of HIV-1, the virus responsible for the AIDS (Acquired ImmunoDeficiency
Syndrome) pandemic having already infected more than 60 million people.
Only non-human primates (NHPs) species from Africa are infected with SIVs.
Serological evidence of SIV positivity has been shown for at least 40 of the 69 primate
species found in Africa and this has been confirmed by DNA sequence analysis in 32
species.
Generally, SIVs do not induce an AIDS-like syndrome in their natural hosts,
suggesting that they have been associated and evolved with their hosts over an
extended period of time. However, if SIV crosses the species barrier, it may become
pathogenic to the new host. The ancestors of HIV-1 and HIV-2 have crossed the
species barrier to humans on multiple occasions, most likely through the contact with
infected blood and tissues from primates hunted for bushmeat.
Bushmeat hunting has been a longstanding practice throughout sub-Saharan
Africa, but the trade has increased in the last decades. Commercial logging has led to
the construction of roads into remote forest areas and hunters are now making use of
this newly developed infrastructure to penetrate previously inaccessible forests and
capture and transport bushmeat to major city markets. Moreover, villages around
logging concessions have become more densely populated; this has also increased the
trade and consumption around these areas.
The socio-economic and environmental changes occurring combined with the growing
genetic diversity and SIV prevalence among non-human primate populations, suggest
that today, more than previously, the human population is exposed to SIVs. Bushmeat
hunting is not limited to chimpanzees, gorillas or sooty mangabeys: the majority of
NHPs is represented by many Cercopithecus and Colobus species for example. It is
therefore important to continue the search and the characterisation of new SIVs and to
determine the prevalence of infection in the NHP, in order to better evaluate which of
these SIVs represent a health threat for the human population.
The main goal of this thesis were
(i) to determine SIV infection and investigate its prevalence among
different social groups of monkeys living in Taï National Park,
Côte d’Ivoire, knowing that these NHPs are heavily hunted
around this area
(ii) to determine SIV infection and prevalence and to characterise at
a molecular level the SIV possibly infecting the red colobus
species found in Abuko Nature Reserve, the Gambia. Two
different subspecies of red colobus are found in the Gambia and
in Côte d’Ivoire: this represented an opportunity to investigate
whether different subspecies may harbour genetically different
viruses and therefore to better understand the impact of
geographical barriers on the evolution of SIV
(iii) to compare the molecular structure of SIVs infecting red and olive
colobus, two sister species in the Colobinae subfamily
(iv) to determine if the chimpanzee subspecies found in West Africa
is infected with a virus similar to that of the monkey species it
preys upon, knowing that, to date, only the subspecies from
West-central and East Africa have been found to be infected with
SIV.
The majority of the results presented in this thesis have been obtained by
analysing data collected with non-invasive methods. SIV infection has been determined
in NHPs by detecting antibodies or by isolating viral sequences from freshly dropped
faecal samples collected in the forests of Côte d’Ivoire and The Gambia. In order to be
able to discriminate the faecal samples collected and, consequently, to reliably
determine the prevalence of infection in a monkey group, the host has been genotyped
by analysing the DNA extracted from the epithelial cells debris released from the
intestine. Host genotyping, antibody detection and isolation of viral RNA from faecal
samples have become possible thanks to the improvement of conservation methods
and DNA and RNA extraction techniques.
Wild-living non-human primate populations often live in inaccessible areas and
tend to be wary of the presence of observers or display cryptic behaviour; the difficulty in
sampling increases when the target species are arboreal primates exploiting the higher
layers of the forest canopy. To mitigate these problems, we selected two field sites
(Abuko Nature Reserve, The Gambia and Taï National Park, Côte d’Ivoire) where the
primate populations were at least partly habituated by the presence of human observers
and where behavioural-ecology studies have been conducted for more than 10 years.
In fact, SIV is transmitted mainly sexually, but possibly also vertically (from the
mother to the offspring) and through biting or infection of open wounds. It is therefore
important to consider factors such as mating system, patterns of dispersal, group size,
average number of adult males in a group, polyspecific associations, etc. as parameters
conducive to the transmission of the virus within or across groups and species.
In total, more than 300 faecal samples from two groups of western red colobus
(Piliocolobus badius badius), from two groups of black-and-white colobus (Colobus
polykomos polykomos), from three groups of olive colobus (Procolobus verus), from
three groups of Diana monkeys (Cercopithecus diana), from one group of Campbell’s
monkeys (Cercopithecus campbelli), from one group of lesser-spot nosed monkeys
(Cercopithecus petaurista) and from a group of greater spot-nosed monkeys
(Cercopithecus nictitans) were collected near the western border of the Taï Forest, in
Côte d’Ivoire, between March and July 2004.
To discriminate the faecal samples collected, 16 microsatellite loci were screened
in these seven monkey species using cross-specific human markers. Microsatellites are
di-tri-tetra-nucleotide tandem repeats, which length’s variability is transmitted by
Mendelian inheritance and can therefore be used in combination for individual
discrimination. Between 25% to 37% of the primers used were informative and
successfully and reliably amplified faecal extracted DNA from all species (Chapter 5).
Colobus and Cercopithecus samples were first tested for the presence of HIV
cross-reactive antibodies using an immunoblotting assay and were found to be all
negative or ‘non interpretable’.
Subsequently, Reverse Transcriptase-Polymerase Chain Reactions (RT-PCRs) using
universal as well as species-specific primers that target the gag, pol and env regions of
the SIV genome were performed: only the western red colobus tested positive for SIV
infection.
Among the inferred 53 adult individuals belonging to two neighbouring habituated
groups, 14 tested SIVwrc (western red colobus) positive with a prevalence of 26%.
Phylogenetic analysis of pol and env sequences revealed a low degree of viral genetic
diversity in each group. The viral sequences obtained were generally clustering together
according to their respective social group of origin. Conversely, the degree of viral
genetic diversity between the two groups was higher.
Behavioural and demographic data collected previously from these communities
indicate that western red colobus monkeys live in promiscuous multi-male societies,
where females leave their natal group as sub-adults and where extra-group copulations
or male immigration have been rarely observed. Phylogenetic data reflect these
behavioural characteristics (Chapter 6).
The negative SIV results obtained for the other investigated species may reflect
their social structure and mating system, but possibly also the difficulty of group
monitoring, faecal sample collection coverage in the field as well as the long term
conservation of viral RNA in the field and the sensitivity and specificity of SIV serological
and molecular detection tools respectively (Chapter 9).
In parallel, sixteen faecal samples from sixteen individuals and two tissue
samples from two carcasses of Temminck’s red colobus monkeys (Piliocolobus badius
temminckii) collected from the forest floor, between January and February 2005, in the
Abuko Nature Reserve were analysed. None of the 16 faecal samples from Temminck’s
red colobus analysed by RT-PCR were positive. However, SIV infection was identified in
one of the tissue samples, and phylogenetic analyses of partial pol and env sequences
showed that this SIVwrc-Pbt virus strain is closely related to SIVwrc-Pbb strains from
P.b.badius in the Taï Forest, suggesting that geographically separated subspecies can
be infected by closely related viruses. Molecular characterization and phylogenetic
analysis of a SIVwrc-Pbt and two SIVwrc-Pbb full-length genomes, subsequently
sequenced (Chapter 8), confirmed that SIVwrc-Pbt and SIVwrc-Pbb belong to a
species-specific SIV lineage, although distantly related to the SIVlho lineage comprising
SIVs from mandrills (Mandrillus sphinx), l’Hoest (Cercopithecus lhoesti) and sun-tailed
monkeys (Cercopithecus solatus) (Chapters 7 and 8).
More recently, we characterised the full-length genome of the SIV infecting the
olive colobus (SIVolc), by analysing a blood sample collected during a previous study
also conducted in Taï National Park. Olive and western red colobus are sister taxon and
results showed that SIVwrc and SIVolc form distinct lineages, but are closely related
across their entire genome (Chapter 8).
These results confirmed the complex evolutionary history of primate lentiviruses,
which has been driven by host-virus co-speciation, cross-species transmission and
recombination events over an extended period of time. Genomic characterization of
additional SIVs viruses from other Colobines is needed to better understand the
ancestral phylogenetic relationship to SIVs from the l’Hoest lineage and whether
recombination occurred between ancestors of these viruses.
Finally, 5 blood and tissue samples collected from 5 chimpanzee carcasses
during a previous study conducted in Taï National Park, were analysed for SIV infection
in this study. To date, no SIV has been isolated from this subspecies of chimpanzee
(Pan troglodytes verus) found in West Africa. It is known that the chimpanzee hunts
small monkeys and that SIVcpz, the precursor of HIV-1, isolated from the west-central
chimpanzee subspecies (Pan troglodytes troglodytes), is a mosaic virus resulting from
the recombination of viruses from different species of monkeys the chimpanzee preys
upon. Following this line of reasoning, we tested universal as well as species-specific
markers amplifying SIV infecting western red colobus, the favourite prey of chimpanzees
from the Taï Forest. Serological tests conducted on these 5 samples showed a weak
seropositivity in three of them. These results could not be confirmed by PCR. Whether
this chimpanzee subspecies is not infected with SIV or whether it harbours a highly
divergent virus not detected yet by the current molecular tools available remains to be
determined (Chapter 10)
CAP4KAM_nDOF: Computer-Assisted Proofs of existence of KAM tori in Hamiltonian systems with n (>=2) Degrees Of Freedom
No full textIn the folder you can produce by uncompressing the attached zippedfile (namely, that folder is called "CAP4KAM_nDOF"), you should findeverything you need in order to perform a complete computer-assistedproof of existence of invariant tori for a Hamiltonian that satifiesthree assumptions: (i) it describes a (Hamiltonian) system with n>=2 degrees of freedom and its canonical coordinates are n pairs of action-angle variables; (ii) it is close enough to a Kolmogorov normal form (so fulfilling also both the non-resonance and the non-degeneracy conditions usually adopted in the framework of KAM theory); (iii) its expansion in Taylor series (with respect to the actions) is finite, while its Fourier expansions (in the angles) can be infinite.The software included in the present folder "CAP4KAM_nDOF" is anextension of a first public release that was a sort of supplementarymaterial of the paper [VL], i.e.,Locatelli, Ugo (2021), “CAP4KAM2D: Computer-Assisted Proofs Fordemonstrating the existence of 2-Dimensional KAM tori”, MendeleyData, V1, doi: 10.17632/jdx22ysh2s.1The software included in the folder "CAP4KAM_nDOF" is designed tobe in a "easy-to-use" layout. Moreover, it is probably not too difficultto be modified for people expert in programming (in C).Everything about the files included in the folder "CAP4KAM_nDOF" iswidely described in the README.txt, that contains also carefulexplanations that should be useful for running the codes, monitoringthe results, modifying the input files, etc.Eventual corrections or remarks about the software package includedin the folder "CAP4KAM_nDOF" are more than welcome and can besent to the author (Ugo Locatelli) at the following e-mail address: [email protected]
Jean Tardieu, père et artiste. Entretien avec Alix Turolla-Tardieu
No full textInterview of Alix Turolla-Tardieu, the daughter of the poet and author Jean Tardieu
UNITY-Locatelli Meeting Notes
No full textTyped document titled 'UNITY-Father Locatelli Meeting 4/14/89.' Document includes five numerical bullets with agenda items the include an introduction/welcome; history of UNITY; information regarding UNITY "today"; demands; and a session titled 'Open for discussion.' Documents features handwritten notes in black ink. Document does not specify author of agenda or notes
PERCHLORATES AS POWERFUL CATALYSTS IN MANY IMPORTANT ORGANIC TRANSFORMATIONS
No full textFor long times, metallic perchlorates have been considered dangerous compounds[1] in that they function as explosives and as incontrollable oxidizers.
Therefore, the fear of the great hazard connected with their manufacture and uses had prevented an extensive use both in research laboratories and in industrial processes.[2]
However, recently it has been cleared that this bad reputation is due to the mistaken association of metallic perchlorates with the oxidizing potential of perchloric acid and the pyrotechnic performances of NH4ClO4.
In this conference, we report that Magnesium and Zinc perchlorates can be used as powerful Lewis acids in several organic transformations which are commonly employed both in laboratory and industrial processes.
As depicted in the Scheme, perchlorates are able to promote a series of reactions such as:
a) Acylation of alcohols[3,4]
b) Fisher esterification[5]
c) Synthesis of b–enamino esters[6]
d) Protection of the amino group as N-Boc derivative[7]
Moreover, they can act as specific catalysts for the development of a new organic transformations. In fact, the treatment of an alcohol or a phenol with Boc2O in the presence of Mg(ClO4)2 leads to the unexpected formation of the corresponding t-butyl ethers.[8] This represents the first general method to synthesize aromatic t-butyl ethers.
In an analogous manner, the treatment of phenols with diethyl dicarbonate results in a very efficient method to produce difficulty available aryl ethyl carbonates.
Several of the above mentioned transformations can be carried out in the absence of the solvent, and often the catalyst can be easily recovered and reused without an appreciable loss of activity.
Acknowledgement
Work carried out in the framework of the National Project “Stereoselezione in Sintesi Organica. Metodologie e Applicazioni” supported by MIUR, Rome, by the University of Bologna, in the framework of “Progetto di Finanziamento Pluriennale, Ateneo di Bologna”, and by National project FIRB “Progettazione, preparazione e valutazione biologica e farmacologica di nuove molecole organiche quali potenziali farmaci”
References
[1] Schumacher, J. C. Perchlorates-Their Properties, Manufacture and Uses, ACS Monograph Series, Reinhold: New York, 1960.Author. Title[J]. Name of the journal, Year, Volume(Issue): initial page and ending page (Optional).
[2] Long, J. Chemical Health & Safety, 2002, 9, 12.
[3] Bartoli, G.; Bosco, M.; Dalpozzo, R.; Marcantoni, E.; Massaccesi, M.; Rinaldi, S.; Sambri, L. Synlett, 2003, 39.
[4] Bartoli, G.; Bosco, M.; Dalpozzo, R.; Marcantoni, E.; Massaccesi, M.; Sambri, L. Eur. J. Org. Chem. 2003, 4611.
[5] a) Gooβen, L.; Döhring, A. Adv. Synth. Catal. 2003, 345, 943; b) Bartoli, G.; Boeglin, J.; Bosco, M.; Locatelli, M.; Massaccesi, M.; Melchiorre, P.; Sambri, L. Adv. Synth. Catal. 2005, 347, 33.
[6] Bartoli, G.; Bosco, M.; Locatelli, M.; Marcantoni, E.; Melchiorre, P.; Sambri, L. Synlett 2004, 239.
[7] Bartoli, G.; Bosco, M.; Locatelli, M.; Marcantoni, E.; Massaccesi, M.; Melchiorre, P.; Sambri, L. Synlett 2004, 1794.
[8] Bartoli, G.; Bosco, M.; Locatelli, M.; Marcantoni, E.; Melchiorre, P.; Sambri, L. Org. Lett., 2004, 7, 427
Longitudinal Analysis of Generic Substitution
No full textUsing an extensive longitudinal dataset extracted from the Norwegian Prescription Database (NorPD) containing all prescriptions written in the period January 2004 to June 2007, we selected two particular drugs (chemical substances) used against cholesterol. The two brand-name products on the Norwegian markets were Provachol (atc code C10AA03) and Zocor (atc code C10AA01). The generics are Provastatine and Simastatine. The model accounts for taste persistence and is estimated on panel data. We find that prices have a negative impact on transitions in the sense that an increase in the brand price will reduce the transition from generics to brand and likewise an increase in the generic price will reduce the transition from brand to generics.generics, substitution, microdata, random utility model, longitudinal data
2. Genetic prothrombotic factors in children with otogenic lateral sinus thrombosis: five case reports
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Genetic prothrombotic factors in children with otogenic lateral sinus thrombosis: five case reports
Author(s): Zangari, P (Zangari, Paola)1; Messia, V (Messia, Virginia)1; Viccaro, M (Viccaro, Marika)2; Bottero, S (Bottero, Sergio)2; Randisi, F (Randisi, Francesco)3; Marsella, P (Marsella, Pasquale)2; Luciani, M (Luciani, Matteo)4; Locatelli, F (Locatelli, Franco)4
Source: BLOOD COAGULATION & FIBRINOLYSIS Volume: 23 Issue: 2 Pages: 158-163 DOI: 10.1097/MBC.0b013e328349cafb Published: MAR 2012
Times Cited: 0 (from Web of Science)
Cited References: 20 [ view related records ] Citation Map
Abstract: Lateral sinus thrombosis (LST) is an uncommon, but life-threatening complication of both acute and chronic otitis media. There is some evidence that acquired or hereditary prothrombotic disorders are risk factors for LST. The aim of this work was to evaluate the role of thrombotic screening, anticoagulant therapy or prophylaxis in patients with either acute or chronic otitis media and LST. The medical records of five children hospitalized at Pediatric Hospital Bambino Gesu of Rome because of acute or chronic otitis media complicated by mastoiditis and LST were reviewed. All children underwent laboratory workup for hypercoagulability. All the five children were found to be heterozygote for the C677T MTHFR mutation and a child presented also heterozygosity for factor V Leiden mutation. They have been successfully treated with anticoagulant therapy without sequels. Children with acute or chronic otitis media may have a prothrombotic tendency that becomes clinically evident because of the inflammatory state. Patients with a family and/or personal history of thrombosis and/or thrombophilic conditions need anticoagulant prophylaxis also in the absence of clear signs of LST. Treatment with low molecular weight is successful in patients with LST. Blood Coagul Fibrinolysis 23:158-163 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins
Jean Tardieu, père et artiste. Entretien avec Alix Turolla-Tardieu
No full textInterview of Alix Turolla-Tardieu, the daughter of the poet and author Jean Tardieu
sj-docx-2-tam-10.1177_17588359221113693 – Supplemental material for Targeted therapy for pediatric diffuse intrinsic pontine glioma: a single-center experience
No full textSupplemental material, sj-docx-2-tam-10.1177_17588359221113693 for Targeted therapy for pediatric diffuse intrinsic pontine glioma: a single-center experience by Giada Del Baldo, Andrea Carai, Rachid Abbas, Antonella Cacchione, Mara Vinci, Valentina Di Ruscio, Giovanna Stefania Colafati, Sabrina Rossi, Francesca Diomedi Camassei, Nicola Maestro, Sara Temelso, Giulia Pericoli, Emmanuel De Billy, Isabella Giovannoni, Alessia Carboni, Martina Rinelli, Emanuele Agolini, Alan Mackay, Chris Jones, Silvia Chiesa, Mario Balducci, Franco Locatelli and Angela Mastronuzzi in Therapeutic Advances in Medical Oncology</p
sj-docx-1-tam-10.1177_17588359221113693 – Supplemental material for Targeted therapy for pediatric diffuse intrinsic pontine glioma: a single-center experience
No full textSupplemental material, sj-docx-1-tam-10.1177_17588359221113693 for Targeted therapy for pediatric diffuse intrinsic pontine glioma: a single-center experience by Giada Del Baldo, Andrea Carai, Rachid Abbas, Antonella Cacchione, Mara Vinci, Valentina Di Ruscio, Giovanna Stefania Colafati, Sabrina Rossi, Francesca Diomedi Camassei, Nicola Maestro, Sara Temelso, Giulia Pericoli, Emmanuel De Billy, Isabella Giovannoni, Alessia Carboni, Martina Rinelli, Emanuele Agolini, Alan Mackay, Chris Jones, Silvia Chiesa, Mario Balducci, Franco Locatelli and Angela Mastronuzzi in Therapeutic Advances in Medical Oncology</p
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