62 research outputs found
3d collagen hydrogel promotes in vitro langerhans islets vascularization through ad-mvfs angiogenic activity
Adipose derived microvascular fragments (ad-MVFs) consist of effective vascularization units able to reassemble into efficient microvascular networks. Because of their content in stem cells and related angiogenic activity, ad-MVFs represent an interesting tool for applications in regenerative medicine. Here we show that gentle dissociation of rat adipose tissue provides a mixture of ad-MVFs with a length distribution ranging from 33–955 µm that are able to maintain their original morphology. The isolated units of ad-MVFs that resulted were able to activate transcriptional switching toward angiogenesis, forming tubes, branches, and entire capillary networks when cultured in 3D collagen type-I hydrogel. The proper involvement of metalloproteases (MMP2/MMP9) and serine proteases in basal lamina and extracellular matrix ECM degradation during the angiogenesis were concurrently assessed by the evaluation of alpha-smooth muscle actin (αSMA) expression. These results suggest that collagen type-I hydrogel provides an adequate 3D environment supporting the activation of the vascularization process. As a proof of concept, we exploited 3D collagen hydrogel for the setting of ad-MVF–islet of Langerhans coculture to improve the islets vascularization. Our results suggest potential employment of the proposed in vitro system for regenerative medicine applications, such as the improving of the islet of Langerhans engraftment before transplantation
Native rodent species are unlikely sources of infection for Leishmania (Viannia) braziliensis along the Transoceanic Highway in Madre de Dios, Peru.
An estimated 2.3 million disability-adjusted life years are lost globally from leishmaniasis. In Peru's Amazon region, the department of Madre de Dios (MDD) rises above the rest of the country in terms of the annual incidence rates of human leishmaniasis. Leishmania (Viannia) braziliensis is the species most frequently responsible for the form of disease that results in tissue destruction of the nose and mouth. However, essentially nothing is known regarding the reservoirs of this vector-borne, zoonotic parasite in MDD. Wild rodents have been suspected, or proven, to be reservoirs of several Leishmania spp. in various ecosystems and countries. Additionally, people who live or work in forested terrain, especially those who are not regionally local and whose immune systems are thus naïve to the parasite, are at most risk for contracting L. (V.) braziliensis. Hence, the objective of this study was to collect tissues from wild rodents captured at several study sites along the Amazonian segment of the newly constructed Transoceanic Highway and to use molecular laboratory techniques to analyze samples for the presence of Leishmania parasites. Liver tissues were tested via polymerase chain reaction from a total of 217 rodents; bone marrow and skin biopsies (ear and tail) were also tested from a subset of these same animals. The most numerous rodent species captured and tested were Oligoryzomys microtis (40.7%), Hylaeamys perenensis (15.7%), and Proechimys spp. (12%). All samples were negative for Leishmania, implying that although incidental infections may occur, these abundant rodent species are unlikely to serve as primary reservoirs of L. (V.) braziliensis along the Transoceanic Highway in MDD. Therefore, although these rodent species may persist and even thrive in moderately altered landscapes, we did not find any evidence to suggest they pose a risk for L. (V.) braziliensis transmission to human inhabitants in this highly prevalent region
Avian influenza infections in non-migratant land birds in Andean Peru
As part of ongoing surveillance for avian influenza viruses (AIV) in Peruvian birds, in June 2008, we sampled 600 land birds of 177 species, using real-time reverse-transcription PCR. We addressed the assumption that AIV prevalence is low or nil among land birds, a hypothesis that was not supported by the results—rather, we found AIV infections at relatively high prevalences in birds of the orders Apodiformes (hummingbirds) and Passeriformes (songbirds). Surveillance programs for monitoring spread and identification of AIV should thus not focus solely on water birds.We thank ornithologists Michael Andersen, Roger Boyd, Adolfo Navarro-Siguenza, Luis Sanchez-Gonzalez, and Mark Robbins; the staff of CORBIDI, Lima, Peru, for extensive assistance with logistics associated with field sampling of birds; M. Papes¸ for assistance with maps; and A. E. Gonzalez for extending facilities and hospitality at the School of Veterinary Medicine, Universidad Nacional.
Mayor de San Marcos. The study was funded by the National Institutes of Health–Fogarty International Center, US Department of Defense AFHSC-GEIS grant GF0121_07_LI, and R.A.J.W. was supported by grant CGL2010-15734/BOS, Ministerio de Ciencia e Innovacion, Spain, and a Tinker Field Research grant
Neural Crest-Derived Chondrocytes Isolation for Tissue Engineering in Regenerative Medicine
Chondrocyte transplantation has been successfully tested and proposed as a clinical procedure aiming to repair articular cartilage defects. However, the isolation of chondrocytes and the optimization of the enzymatic digestion process, as well as their successful in vitro expansion, remain the main challenges in cartilage tissue engineering. In order to address these issues, we investigated the performance of recombinant collagenases in tissue dissociation assays with the aim of isolating chondrocytes from bovine nasal cartilage in order to establish the optimal enzyme blend to ensure the best outcomes of the overall procedure. We show, for the first time, that collagenase H activity alone is required for effective cartilage digestion, resulting in an improvement in the yield of viable cells. The extracted chondrocytes proved able to grow and activate differentiation/dedifferentiation programs, as assessed by morphological and gene expression analyses
Prevalence of paramyxoviruses in bats in six areas of Madre de Dios and Puno, Peru with two levels of anthropogenic disturbance
Los Andes tropicales que comprende la región de Madre de Dios, Perú, es considerada una zona de conservación para la biodiversidad; sin embargo, el reciente desarrollo de la zona a través de la pavimentación de la carretera interoceánica (CIO) ha ocasionado un impacto antropogénico en la región. Este estudio tuvo como objetivo identificar la prevalencia de paramixovirus, patógenos emergentes de importancia para la salud pública y animal, en murciélagos capturados a lo largo de los tramos de la CIO sujetos a diferentes grados de perturbación ecológica. La captura se hizo entre octubre de 2009 a octubre de 2010 en tres zonas altamente perturbadas y tres zonas con un grado de perturbación moderado a ligero; además, en la Reserva Nacional de Tambopata como grupo control. Se analizaron muestras de bazo mediante la técnica de RT-PCR semianidado que detecta las regiones conservadas del gen de la polimerasa. Se capturaron 436 murciélagos de 24 géneros y 35 especies, encontrándose una prevalencia de paramixovirus de 10.3% (IC 95%: 7.6-13.6%). La prevalencia fue de 15.7% en lugares clasificados con alto grado de perturbación ecológica, siendo significativamente mayor (p=0.009) que en lugares con moderado grado de perturbación (5.6%) y en la zona control (8.3%). La especie Artibeus planisrostris mostró la más alta frecuencia de infección (37%). Mediante el análisis de secuencia se identificaron tres muestras positivas a paramixovirus agrupadas dentro del género Morbillivirus (no clasificada) en las especies Carollia brevicuda y C. perspicillata; asà como miembros del género Rubulavirus (Mapuera virus) en tres muestras de murciélagos adultos de la especie Sturnira lilium colectados en el distrito de Iberia.The tropical Andes, comprising the Madre de Dios region, are a hotspot for biodiversity conservation. Recent development of the area through paving of the interoceanic highway (IOH) resulted in anthropogenic impacts in the region. This study aimed to identify the prevalence of emerging pathogens of public and animal health importance such as Paramyxoviruses among bats trapped along areas of IOH with different ecological impacts. Samples from six study sites along the IOH were collected from October 2009 to October 2010: three highly disturbed areas and three areas with low disturbance. A site located at the Tambopata National Reserve was selected as an undisturbed environment for control. Bat spleens were tested for Paramyxoviruses by nested PCR targeting the conserved motifs of the polymerase gene. A total of 436 bats from 24 different genera were captured, of which 45 (10.32%; CI 95%: 7.6-13.6%) were positive for Paramyxoviruses. The prevalence was higher in areas with more disturbance than in mildly disturbed areas (15.7 vs. 5.6%, p=0.009). The prevalence in the control area was 8.3%. The species Artibeus planirostris showed the highest infection frequency (37%, 17/45). Three positive bats were adults of the Sturnira lilium species collected from one location in Iberia District. Sequence analysis placed these viruses in the Rubulavirus genera (Mapuera virus). The remaining viruses were related to an unclassified Morbillivirus found in bat samples in Brazil during 2013
Avian Influenza in Wild Birds, Central Coast of Peru
To determine genotypes of avian influenza virus circulating among wild birds in South America, we collected and tested environmental fecal samples from birds along the coast of Peru, June 2006–December 2007. The 9 isolates recovered represented 4 low-pathogenicity avian influenza strains: subtypes H3N8, H4N5, H10N9, and H13N2
Diversity, distribution and natural Leishmania infection of sand flies from communities along the Interoceanic Highway in the Southeastern Peruvian Amazon
The Peruvian-Brazilian border is a highly endemic tegumentary leishmaniasis region in South America. The interoceanic highway is a commercial route that connects Peru and Brazil through Madre de Dios and has raised concerns about its impact on previously undisturbed areas. In order to assess leishmaniasis transmission risk along this highway, we conducted a surveillance study of the sand fly populations in this area. Sand flies were collected between 2009 and 2010 along transects at 200 m, 600 m and 1000 m from six study sites located along the highway (Iberia, La Novia, Alto Libertad, El Carmen, Florida Baja, Mazuko and Mavila) and an undisturbed area (Malinowski). Collected specimens were identified based on morphology and non-engorged females of each species were pooled and screened by kinetoplast PCR to detect natural Leishmania infections. A total of 9,023 specimens were collected belonging to 54 different Lutzomyia species including the first report of Lu. gantieri in Peru. Four species accounted for 50% of all specimens (Lutzomyia carrerai carrerai, Lu. davisi, Lu. shawi and Lu. richardwardi). El Carmen, Alto Libertad, Florida Baja and Malinowski presented higher Shannon diversity indexes (H = 2.36, 2.30, 2.17 and 2.13, respectively) than the most human disturbed sites of Mazuko and La Novia (H = 1.53 and 1.06, respectively). PCR detected 10 positive pools belonging to Lu. carrerai carrerai, Lu. yuilli yuilli, Lu. hirsuta hirsuta, Lu. (Trichophoromyia) spp., and Lu. (Lutzomyia) spp. Positive pools from 1,000 m transects had higher infectivity rates than those from 600 m and 200 m transects (9/169 = 5.3% vs 0/79 = 0% and 1/127 = 0.8%, p = 0.018). El Carmen, accounted for eight out of ten positives whereas one positive was collected in Florida Baja and Mazuko each. Our study has shown differences in sand fly diversity, abundance and species composition across and within sites. Multiple clustered Lutzomyia pools with natural Leishmania infection suggest a complex, diverse and spotty role in leishmaniasis transmission in Madre de Dios, with increased risk farther from the highway
Diversity and prevalence of zoonotic infections at the animal-human interface of primate trafficking in Peru
Wildlife trafficking creates favorable scenarios for intra- and inter-specific interactions that can lead to parasite spread and disease emergence. Among the fauna affected by this activity, primates are relevant due to their potential to acquire and share zoonoses - infections caused by parasites that can spread between humans and other animals. Though it is known that most primate parasites can affect multiple hosts and that many are zoonotic, comparative studies across different contexts for animal-human interactions are scarce. We conducted a multi-parasite screening targeting the detection of zoonotic infections in wild-caught monkeys in nine Peruvian cities across three contexts: captivity (zoos and rescue centers, n = 187); pet (households, n = 69); and trade (trafficked or recently confiscated, n = 132). We detected 32 parasite taxa including mycobacteria, simian foamyvirus, bacteria, helminths, and protozoa. Monkeys in the trade context had the highest prevalence of hemoparasites (including Plasmodium malariae/brasilianum, Trypanosoma cruzi, and microfilaria) and enteric helminths and protozoa were less common in pet monkeys. However, parasite communities showed overall low variation between the three contexts. Parasite richness (PR) was best explained by host genus and the city where the animal was sampled. Squirrel (genus Saimiri) and wooly (genus Lagothrix) monkeys had the highest PR, which was ~2.2 times the PR found in tufted capuchins (genus Sapajus) and tamarins (genus Saguinus/Leontocebus) in a multivariable model adjusted for context, sex, and age. Our findings illustrate that the threats of wildlife trafficking to One Health encompass exposure to multiple zoonotic parasites well-known to cause disease in humans, monkeys, and other species. We demonstrate these threats continue beyond the markets where wildlife is initially sold; monkeys trafficked for the pet market remain a reservoir for and contribute to the translocation of zoonotic parasites to households and other captive facilities where contact with humans is frequent. Our results have practical applications for the healthcare of rescued monkeys and call for urgent action against wildlife trafficking and ownership of monkeys as pets
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The Simons Observatory: Science goals and forecasts
The Simons Observatory (SO) is a new cosmic microwave background experiment
being built on Cerro Toco in Chile, due to begin observations in the early
2020s. We describe the scientific goals of the experiment, motivate the design,
and forecast its performance. SO will measure the temperature and polarization
anisotropy of the cosmic microwave background in six frequency bands: 27, 39,
93, 145, 225 and 280 GHz. The initial configuration of SO will have three
small-aperture 0.5-m telescopes (SATs) and one large-aperture 6-m telescope
(LAT), with a total of 60,000 cryogenic bolometers. Our key science goals are
to characterize the primordial perturbations, measure the number of
relativistic species and the mass of neutrinos, test for deviations from a
cosmological constant, improve our understanding of galaxy evolution, and
constrain the duration of reionization. The SATs will target the largest
angular scales observable from Chile, mapping ~10% of the sky to a white noise
level of 2 K-arcmin in combined 93 and 145 GHz bands, to measure the
primordial tensor-to-scalar ratio, , at a target level of .
The LAT will map ~40% of the sky at arcminute angular resolution to an expected
white noise level of 6 K-arcmin in combined 93 and 145 GHz bands,
overlapping with the majority of the LSST sky region and partially with DESI.
With up to an order of magnitude lower polarization noise than maps from the
Planck satellite, the high-resolution sky maps will constrain cosmological
parameters derived from the damping tail, gravitational lensing of the
microwave background, the primordial bispectrum, and the thermal and kinematic
Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle
polarization signal to measure the tensor-to-scalar ratio. The survey will also
provide a legacy catalog of 16,000 galaxy clusters and more than 20,000
extragalactic sources
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