23 research outputs found
Liver fibrosis is strongly associated with an enhanced level of immunosuppressive tryptophan catabolism independently of HCV viremia in ART-treated HIV/HCV co-infected patients
A 60-million-year Cenozoic history of western Amazonian ecosystems in Contamana, eastern Peru
Weprovide a synopsis of ~60million years of life history in Neotropical lowlands, based on a comprehensive survey of the Cenozoic deposits along the Quebrada Cachiyacu near Contamana in PeruvianAmazonia. The 34 fossilbearing localities identified have yielded a diversity of fossil remains, including vertebrates,mollusks, arthropods, plant fossils, and microorganisms, ranging from the early Paleocene to the lateMioceneâ?Pliocene (N20 successive levels). This Cenozoic series includes the base of the Huchpayacu Formation (Fm.; early Paleocene; lacustrine/ fluvial environments; charophyte-dominated assemblage), the Pozo Fm. (middle + ?late Eocene; marine then freshwater environments; most diversified biomes), and complete sections for the Chambira Fm. (late Oligoceneâlate early Miocene; freshwater environments; vertebrate-dominated faunas), the Pebas Fm. (late early to early late Miocene; freshwater environments with an increasing marine influence; excellent fossil record), and Ipururo Fm. (late Mioceneâ?Pliocene; fully fluvial environments; virtually no fossils preserved). At least 485 fossil species are recognized in the Contamana area (~250 âplantsâ, ~212 animals, and 23 foraminifera). Based on taxonomic lists from each stratigraphic interval, high-level taxonomic diversity remained fairly constant throughout themiddle EoceneâMiocene interval (8-12 classes), ordinal diversity fluctuated to a greater degree, and family/species diversity generally declined, with a drastic drop in the early Miocene. The Paleoceneâ?Pliocene fossil assemblages from Contamana attest at least to four biogeographic histories inherited from (i) Mesozoic Gondwanan times, (ii) the Panamerican realm prior to (iii) the time of South Americaâs Cenozoic âsplendid isolationâ, and (iv) Neotropical ecosystems in the Americas. No direct evidence of any North American terrestrial immigrant has yet been recognized in the Miocene record at Contamana.Facultad de Ciencias Naturales y Muse
The Lipopolysaccharide Core of Brucella abortus Acts as a Shield Against Innate Immunity Recognition
Innate immunity recognizes bacterial molecules bearing pathogen-associated molecular patterns to launch inflammatory responses leading to the activation of adaptive immunity. However, the lipopolysaccharide (LPS) of the gram-negative bacterium Brucella lacks a marked pathogen-associated molecular pattern, and it has been postulated that this delays the development of immunity, creating a gap that is critical for the bacterium to reach the intracellular replicative niche. We found that a B. abortus mutant in the wadC gene displayed a disrupted LPS core while keeping both the LPS O-polysaccharide and lipid A. In mice, the wadC mutant induced proinflammatory responses and was attenuated. In addition, it was sensitive to killing by non-immune serum and bactericidal peptides and did not multiply in dendritic cells being targeted to lysosomal compartments. In contrast to wild type B. abortus, the wadC mutant induced dendritic cell maturation and secretion of pro-inflammatory cytokines. All these properties were reproduced by the wadC mutant purified LPS in a TLR4-dependent manner. Moreover, the core-mutated LPS displayed an increased binding to MD-2, the TLR4 co-receptor leading to subsequent increase in intracellular signaling. Here we show that Brucella escapes recognition in early stages of infection by expressing a shield against recognition by innate immunity in its LPS core and identify a novel virulence mechanism in intracellular pathogenic gram-negative bacteria. These results also encourage for an improvement in the generation of novel bacterial vaccines
Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study
: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (pâ=â0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (pâ=â0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (pâ=â0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (pâ=â0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (pâ=â0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (pâ=â0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (pâ=â0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (pâ<â0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (pâ=â0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (pâ=â0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)
Brucella abortus Induces the Premature Death of Human Neutrophils through the Action of Its Lipopolysaccharide
Most bacterial infections induce the activation of polymorphonuclear neutrophils (PMNs), enhance their microbicidal function, and promote the survival of these leukocytes for protracted periods of time. Brucella abortus is a stealthy pathogen that evades innate immunity, barely activates PMNs, and resists the killing mechanisms of these phagocytes. Intriguing clinical signs observed during brucellosis are the low numbers of Brucella infected PMNs in the target organs and neutropenia in a proportion of the patients; features that deserve further attention. Here we demonstrate that B. abortus prematurely kills human PMNs in a dose-dependent and cell-specific manner. Death of PMNs is concomitant with the intracellular Brucella lipopolysaccharide (Br-LPS) release within vacuoles. This molecule and its
lipid A reproduce the premature cell death of PMNs, a phenomenon associated to the low production of proinflammatory cytokines. Blocking of CD14 but not TLR4 prevents the Br-LPS-induced cell death. The PMNs cell death departs from necrosis, NETosis and classical apoptosis. The mechanism of PMN cell death is linked to the activation of NADPH-oxidase and a modest but steadily increase of ROS mediators. These effectors generate DNA damage, recruitments of check point kinase 1, caspases 5 and to minor extent of caspase 4, RIP1 and Ca++ release. The production of IL-1ÎČ by PMNs was barely stimulated by B. abortus infection or Br-LPS treatment. Likewise, inhibition of caspase 1 did not hamper the Br-LPS induced PMN cell death, suggesting that the inflammasome pathway was not involved. Although activation of caspases 8 and 9 was observed, they did not seem to participate in the initial triggering mechanisms, since inhibition of these caspases scarcely blocked PMN cell death. These findings suggest a mechanism for neutropenia in chronic brucellosis and reveal a novel Brucella-host cross-talk through which B. abortus is able to hinder the innate function of PMN.Fondo Especial de la EducaciĂłn Superior/[0500-13]/FEES/Costa RicaFondo Especial de la EducaciĂłn Superior/[0504-13]/FEES/Costa RicaFondo Especial de la EducaciĂłn Superior/[0505-13]/FEES/Costa RicaFondo Especial de la EducaciĂłn Superior/[0248-13]/FEES/Costa RicaUCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias de la Salud::Centro de InvestigaciĂłn en Enfermedades Tropicales (CIET)UCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)UCR::VicerrectorĂa de Docencia::Salud::Facultad de MicrobiologĂ
PatologĂas frecuentes diagnĂłsticadas por cistoscopĂa en el Hospital Dr. Francisco Moscoso Puello, Santo Domingo, RepĂșblica Dominicana, Julio 2002-Julio 2004
Por medio de la cistoscopia, que es una tecnica que consiste en la visualizacion de la vejiga y la uretra por medio de un endoscopio especializado, denominado cistoscopio, se pueden diagnosticar un gran numero de patologias de las vias urinarias. Pero no es tan sencillo debido a que no todas las enfermedades de! tracto urinario pueden ser detectadas por este estudio.
El objetivo de este trabajo es identificar cuales son las patologias del tracto urinario frecuentes que si pueden ser diagnosticadas por cistoscopia, para poder separarlas de las que no, y establecer cual es la frecuencia de cada una de ellas.
Es una investigacion tipo descriptiva y el disefio metodologico empleado es retrospectivo, las tecnicas empleadas en la realizacion de este trabajo son revision de la literatura y la revision de las hojas de cistoscopia de los pacientes. La poblacion fueron todos los pacientes que se realizaron una cistoscopia en el Hospital Dr. Francisco Moscoso Puello en el periodo julio 2002- julio 2004, la muestra es no aleatoria y consistio en 150 pacientes que cumplieron con los criterios de inclusion y exclusion.
A partir de esta investigaciĂłn se obtuvo que la cistitis fue la patologia mas frecuente presentandose 65 casos, seguida de! cancer vesical con 16 casos y luego las fistulas vesicovaginales con 13 casos. El tipo de cistitis mas comun fue la crĂłnica presentandose en un 74% de los casos.
La cistitis tuvo mayor frecuencia en mujeres queen hombres, debido a que la uretra de la mujer esta mas expuesta a infecciones debido a su corta longitud y que es mas externa que la masculina. La lesion de la prĂłstata mas frecuente fue la hiperplasia prostatica benigna (HPB) con un 80% de todas las patologias de la prĂłstata presentadas.
De acuerdo a todos los resultados de! trabajo, la mayoria de patologias se localizaron en la vejiga con un 80%, esto se debe a que las principales enfermedades se presentaron en esa zona de! tracto urinario
Refractive predictability and visual outcomes of an extended range of vision intraocular lens in eyes with previous myopic laser in situ keratomileusis
Purpose: To evaluate the refractive predictability obtained with an extended range of vision intraocular lens in eyes with previous myopic laser in situ keratomileusis, confirming which intraocular lens power formula provides the most accurate calculation. Methods: The study enrolled 71 eyes with previous successful myopic laser in situ keratomileusis surgery of 43 patients undergoing cataract surgery with implantation of the extended range of vision intraocular lens TECNIS Symfony (Johnson and Johnson Vision). Intraocular lens power was calculated using all American Society of Cataract and Refractive Surgeons formulas, and their average value was selected for implantation. Refractive outcomes were evaluated at 3âmonths postoperatively. Results: Postoperative spherical equivalent within ±0.50 and ±1.00âD was found in 61.6% and 86.3% of eyes, respectively. In eyes with pre-laser in situ keratomileusis data available, no significant correlation was found between pre-laser in situ keratomileusis spherical equivalent and post-cataract surgery spherical equivalent (râ=â0.237, pâ=â0.114). A postoperative spherical equivalent within ±0.50âD was found in 65.2% and 55.6% of eyes in the subgroups with and without pre-laser in situ keratomileusis data available, respectively (pâ=â0.480). Statistically significantly higher differences between the intraocular lens power implanted and the calculation provided by the PotvinâHill (pâ=â0.028) and Barrett True K No History formulas (pâ=â0.022) were found in those eyes with postoperative spherical equivalentâ>â0.50âD. Conclusion: The extended range of vision intraocular lens evaluated can provide a predictable refractive correction in eyes with previous laser in situ keratomileusis surgery. The PotvinâHill and Barrett True K No History are the most adequate formulas to perform intraocular lens power calculations in these cases
Biotic community and landscape changes around the EoceneâOligocene transition at Shapaja, Peruvian Amazonia: Regional or global drivers?
International audienceSince 2012, we have investigated a stratigraphic section encompassing the late Eoceneâearliest Oligocene interval at Shapaja (Tarapoto area, Peruvian Amazonia, ca. 7°S), through paleontological and geological fieldwork. The measured sedimentary series (120 m-thick [West] plus 90 m-thick [East]), assigned to the upper member of the Pozo Formation, records fluvial micro-conglomeratic lenses intercalated with floodplain and evaporite-rich fine red deposits, estuarine/coastal-plain tidally-influenced fine sandstones, and oxbow lake nodule-rich blue clays. This sedimentary shift coincides locally with the demise of the large Eocene coastal-plain wetland known as Pozo System. The late Eoceneâearly Oligocene Shapaja section was extensively sampled for chemostratigraphy (ÎŽ13C on dispersed organic matter and pedogenic carbonate nodules), which in turn allowed for refining the location of the Eocene-Oligocene Transition (EOT) and other climatic events recognized at a global scale (i.e., Oi-1 and Oi-1a). The section has yielded nine fossil localities with plant remains (leaves, wood, charophytes, and palynomorphs), mollusks, decapods, and/or vertebrates (selachians, actinopterygians, lungfishes, amphibians, sauropsids, and mammals), documenting ~130 distinct taxa. Four localities of the upper member of the Pozo Formation at Shapaja predate the EOT, one is clearly within the EOT, while four are earliest/early Oligocene in age. The small leaf impressions found along the Shapaja section could be indicative of dry and/or seasonal conditions for this region throughout and after the EOT. Monkeys, indicative of tropical rainforest environments, are only recorded in a latest Eocene locality (TAR-21). Two biotic turnovers are perceptible in the selachian, metatherian, and rodent communities, well before the EOT [~35â36 Ma] and a few hundred thousand years after the EOT [~33 Ma]. The latter turnover seems to be primarily related to a global sea-level drop (ichthyofauna: marine-littoral elements replaced by obligate freshwater taxa) and/or the onset of a drier and more seasonal climate in early Oligocene times (terrestrial components). Changes in the structure of the Shapaja paleocommunities were mostly driven by the flexural subsidence during the late Eocene, and then globally driven by the earliest Oligocene climatic deterioration