Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 121
Filter
Add more filters

Publication year range
1.
Cell ; 134(5): 757-68, 2008 Sep 05.
Article in English | MEDLINE | ID: mdl-18775309

ABSTRACT

Prions are unconventional infectious agents composed exclusively of misfolded prion protein (PrP(Sc)), which transmits the disease by propagating its abnormal conformation to the cellular prion protein (PrP(C)). A key characteristic of prions is their species barrier, by which prions from one species can only infect a limited number of other species. Here, we report the generation of infectious prions by interspecies transmission of PrP(Sc) misfolding by in vitro PMCA amplification. Hamster PrP(C) misfolded by mixing with mouse PrP(Sc) generated unique prions that were infectious to wild-type hamsters, and similar results were obtained in the opposite direction. Successive rounds of PMCA amplification result in adaptation of the in vitro-produced prions, in a process reminiscent of strain stabilization observed upon serial passage in vivo. Our results indicate that PMCA is a valuable tool for the investigation of cross-species transmission and suggest that species barrier and strain generation are determined by the propagation of PrP misfolding.


Subject(s)
PrPSc Proteins/metabolism , Prion Diseases/transmission , Prions/metabolism , Animals , Brain/pathology , Cell-Free System , Cricetinae , Mice , Prion Diseases/pathology , Protein Folding , Species Specificity
2.
J Virol ; 95(23): e0112221, 2021 11 09.
Article in English | MEDLINE | ID: mdl-34549980

ABSTRACT

Chikungunya virus (CHIKV) and Mayaro virus (MAYV) are closely related members of the Semliki Forest virus antigenic complex classified as belonging to the genus Alphavirus of the family Togaviridae. These viruses cause human disease, with sudden fever and joint inflammation that can persist for long periods. CHIKV is the causative agent of large outbreaks worldwide, and MAYV infection represents a growing public health concern in Latin America, causing sporadic cases and geographically limited outbreaks. Considering the relationship between CHIKV and MAYV, the present study aimed to evaluate if preexisting CHIKV immunity protects against MAYV infection. Immunocompetent C57BL/6 mice were intraperitoneally infected with CHIKV and, 4 weeks later, they were infected with MAYV in their hind paw. We observed that the preexistence of CHIKV immunity conferred partial cross-protection against secondary MAYV infection, reducing disease severity, tissue viral load, and histopathological scores. Interestingly, CHIKV antibodies from humans and mice showed low cross-neutralization to MAYV, but neutralizing activity significantly increased after secondary infection. Furthermore, depletion of adaptive immune cells (CD4+ T, CD8+ T, and CD19+ B cells) did not alter the cross-protection phenotype, suggesting that distinct cell subsets or a combination of adaptive immune cells stimulated by CHIKV are responsible for the partial cross-protection against MAYV. The reduction of proinflammatory cytokines, such as interferon gamma (IFN-γ), in animals secondarily infected by MAYV, suggests a role for innate immunity in cross-protection. Our findings shed light on how preexisting immunity to arthritogenic alphaviruses may affect secondary infection, which may further develop relevant influence in disease outcome and viral transmission. IMPORTANCE Mosquito-borne viruses have a worldwide impact, especially in tropical climates. Chikungunya virus has been present mostly in developing countries, causing millions of infections, while Mayaro virus, a close relative, has been limited to the Caribbean and tropical regions of Latin America. The potential emergence and spread of Mayaro virus to other high-risk areas have increased the scientific community's attention to an imminent worldwide epidemic. Here, we designed an experimental protocol of chikungunya and Mayaro virus mouse infection, which develops a measurable and quantifiable disease that allows us to make inferences about potential immunological effects during secondary virus infection. Our results demonstrate that previous chikungunya virus infection is able to reduce the severity of clinical outcomes during secondary Mayaro infection. We provide scientific understanding of immunological features during secondary infection with the closely related virus, thus assisting in better comprehending viral transmission and the pathological outcome of these diseases.


Subject(s)
Alphavirus Infections/immunology , Alphavirus Infections/prevention & control , Chikungunya virus/immunology , Cross Protection/immunology , Alphavirus/immunology , Alphavirus Infections/pathology , Animals , Antibodies, Viral/immunology , Chikungunya Fever/virology , Disease Models, Animal , Epidemics , Female , Inflammation , Mice , Mice, Inbred C57BL , Viral Load
3.
Arch Virol ; 167(1): 183-187, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34727217

ABSTRACT

Viral stability under stress conditions may directly affect viral dissemination, seasonality, and pathogenesis. We exposed airborne viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), mumps virus, coxsackievirus B5, human rhinovirus A16, and respiratory syncytial virus, to different temperatures, UV light exposure time, pH values, and osmotic pressures and measured the remaining viral infectivity. Reduced thermal stability was observed for coxsackievirus B5 at 45 °C, while SARS-CoV-2 demonstrated residual infectivity at 55 °C. UV light exposure was an efficient means of viral inactivation but was less efficient for non-enveloped viruses. Rhinovirus A16 and respiratory syncytial virus demonstrated extreme sensitivity to acid conditions, while SARS-CoV-2, rhinovirus A16, and respiratory syncytial virus were unstable in an alkaline environment. The information obtained in this study will be useful for the development of viral inactivation methods and may be correlated with epidemiological and seasonal viral characteristics.


Subject(s)
COVID-19 , Virus Diseases , Viruses , Humans , SARS-CoV-2 , Virus Inactivation
4.
PLoS Pathog ; 15(9): e1007934, 2019 09.
Article in English | MEDLINE | ID: mdl-31479495

ABSTRACT

Mayaro virus (MAYV) is an arbovirus that circulates in Latin America and is emerging as a potential threat to public health. Infected individuals develop Mayaro fever, a severe inflammatory disease characterized by high fever, rash, arthralgia, myalgia and headache. The disease is often associated with a prolonged arthralgia mediated by a chronic inflammation that can last months. Although the immune response against other arboviruses, such as chikungunya virus (CHIKV), dengue virus (DENV) and Zika virus (ZIKV), has been extensively studied, little is known about the pathogenesis of MAYV infection. In this study, we established models of MAYV infection in macrophages and in mice and found that MAYV can replicate in bone marrow-derived macrophages and robustly induce expression of inflammasome proteins, such as NLRP3, ASC, AIM2, and Caspase-1 (CASP1). Infection performed in macrophages derived from Nlrp3-/-, Aim2-/-, Asc-/-and Casp1/11-/-mice indicate that the NLRP3, but not AIM2 inflammasome is essential for production of inflammatory cytokines, such as IL-1ß. We also determined that MAYV triggers NLRP3 inflammasome activation by inducing reactive oxygen species (ROS) and potassium efflux. In vivo infections performed in inflammasome-deficient mice indicate that NLRP3 is involved with footpad swelling, inflammation and pain, establishing a role of the NLRP3 inflammasome in the MAYV pathogenesis. Accordingly, we detected higher levels of caspase1-p20, IL-1ß and IL-18 in the serum of MAYV-infected patients as compared to healthy individuals, supporting the participation of the NLRP3-inflammasome during MAYV infection in humans.


Subject(s)
Alphavirus Infections/immunology , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Adult , Aged , Alphavirus Infections/metabolism , Animals , Carrier Proteins/metabolism , Caspase 1/metabolism , Chikungunya virus/metabolism , Dengue Virus/metabolism , Disease Models, Animal , Female , Humans , Inflammasomes/immunology , Inflammation/metabolism , Macrophages/immunology , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Reactive Oxygen Species/metabolism , Togaviridae/pathogenicity , Zika Virus/metabolism
5.
PLoS Pathog ; 15(6): e1007880, 2019 06.
Article in English | MEDLINE | ID: mdl-31211814

ABSTRACT

The largest ever recorded epidemic of the Chikungunya virus (CHIKV) broke out in 2004 and affected four continents. Acute symptomatic infections are typically associated with the onset of fever and often debilitating polyarthralgia/polyarthritis. In this study, a systems biology approach was adopted to analyze the blood transcriptomes of adults acutely infected with the CHIKV. Gene signatures that were associated with viral RNA levels and the onset of symptoms were identified. Among these genes, the putative role of the Eukaryotic Initiation Factor (eIF) family genes and apolipoprotein B mRNA editing catalytic polypeptide-like (APOBEC3A) in the CHIKV replication process were displayed. We further compared these signatures with signatures induced by the Dengue virus infection and rheumatoid arthritis. Finally, we demonstrated that the CHIKV in vitro infection of murine bone marrow-derived macrophages induced IL-1 beta production in a mechanism that is significantly dependent on the inflammasome NLRP3 activation. The observations provided valuable insights into virus-host interactions during the acute phase and can be instrumental in the investigation of new and effective therapeutic interventions.


Subject(s)
Arthritis/immunology , Chikungunya Fever/immunology , Chikungunya virus/physiology , Cytidine Deaminase/immunology , Proteins/immunology , Virus Replication/immunology , Adult , Animals , Arthritis/pathology , Arthritis/virology , Chikungunya Fever/pathology , Dengue Virus/immunology , Dengue Virus/pathogenicity , Female , Fever/immunology , Fever/pathology , Fever/virology , Follow-Up Studies , Humans , Interleukin-1beta/immunology , Mice , NLR Family, Pyrin Domain-Containing 3 Protein/immunology
6.
Sensors (Basel) ; 21(12)2021 Jun 09.
Article in English | MEDLINE | ID: mdl-34207543

ABSTRACT

Forage dry matter is the main source of nutrients in the diet of ruminant animals. Thus, this trait is evaluated in most forage breeding programs with the objective of increasing the yield. Novel solutions combining unmanned aerial vehicles (UAVs) and computer vision are crucial to increase the efficiency of forage breeding programs, to support high-throughput phenotyping (HTP), aiming to estimate parameters correlated to important traits. The main goal of this study was to propose a convolutional neural network (CNN) approach using UAV-RGB imagery to estimate dry matter yield traits in a guineagrass breeding program. For this, an experiment composed of 330 plots of full-sib families and checks conducted at Embrapa Beef Cattle, Brazil, was used. The image dataset was composed of images obtained with an RGB sensor embedded in a Phantom 4 PRO. The traits leaf dry matter yield (LDMY) and total dry matter yield (TDMY) were obtained by conventional agronomic methodology and considered as the ground-truth data. Different CNN architectures were analyzed, such as AlexNet, ResNeXt50, DarkNet53, and two networks proposed recently for related tasks named MaCNN and LF-CNN. Pretrained AlexNet and ResNeXt50 architectures were also studied. Ten-fold cross-validation was used for training and testing the model. Estimates of DMY traits by each CNN architecture were considered as new HTP traits to compare with real traits. Pearson correlation coefficient r between real and HTP traits ranged from 0.62 to 0.79 for LDMY and from 0.60 to 0.76 for TDMY; root square mean error (RSME) ranged from 286.24 to 366.93 kg·ha-1 for LDMY and from 413.07 to 506.56 kg·ha-1 for TDMY. All the CNNs generated heritable HTP traits, except LF-CNN for LDMY and AlexNet for TDMY. Genetic correlations between real and HTP traits were high but varied according to the CNN architecture. HTP trait from ResNeXt50 pretrained achieved the best results for indirect selection regardless of the dry matter trait. This demonstrates that CNNs with remote sensing data are highly promising for HTP for dry matter yield traits in forage breeding programs.


Subject(s)
Neural Networks, Computer , Remote Sensing Technology , Animals , Brazil , Cattle , Phenotype
7.
Sleep Breath ; 24(2): 455-464, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31240542

ABSTRACT

PURPOSE: Information on access and adherence to positive airway pressure (PAP) treatment is lacking at the regional level in Latin America. This study characterized access and adherence to PAP in patients with moderate-severe obstructive sleep apnea (OSA) in Latin America. METHODS: Cross-sectional study, conducted at 9 sleep centers across Argentina, Brazil, Chile, Colombia, Mexico, and Peru. Adults diagnosed with moderate-severe OSA (apnea-hypopnea index [AHI] ≥ 15/h) in the previous 12-18 months were eligible. Anthropometrics, health coverage, and OSA severity data were collected. Data on access to therapy, barriers to access, adherence, and factors related to non-compliance were obtained via standardized telephone survey. RESULTS: Eight hundred eighty patients (70% male, 54 ± 13 years, AHI 49 ± 28/h, body mass index 32 ± 7 kg/m2) were included. Four hundred ninety patients (56%) initiated PAP, 70 (14%) discontinued therapy during the first year (mainly due to intolerance), and 420 (48%) were still using PAP when surveyed. Health insurance was private in 36.9% of patients, via the social security system in 31.1%, and via the state in 13.3%, and 18.7% did not have any coverage; 49.5% of patients had to pay all equipment costs. Reasons for not starting PAP were unclear or absent indication (42%), coverage problems (36%), and lack of awareness of OSA burden (14%). Patients with better adherence were older (55.3 ± 13 vs 52 ± 13; p = 0.002) and had more severe OSA (AHI 51.8 ± 27 vs 45.6 ± 27; p = 0.001). CONCLUSIONS: Less than half moderate-severe OSA patients started and continue to use PAP. Unclear or absent medical indication and financial limitations were the most relevant factors limiting access to therapy.


Subject(s)
Continuous Positive Airway Pressure/statistics & numerical data , Health Services Accessibility/statistics & numerical data , Patient Compliance/statistics & numerical data , Sleep Apnea, Obstructive/therapy , Adult , Aged , Cross-Sectional Studies , Female , Humans , Latin America , Male , Middle Aged , Surveys and Questionnaires
8.
PLoS Pathog ; 13(11): e1006716, 2017 Nov.
Article in English | MEDLINE | ID: mdl-29131852

ABSTRACT

One of the characteristics of prions is their ability to infect some species but not others and prion resistant species have been of special interest because of their potential in deciphering the determinants for susceptibility. Previously, we developed different in vitro and in vivo models to assess the susceptibility of species that were erroneously considered resistant to prion infection, such as members of the Leporidae and Equidae families. Here we undertake in vitro and in vivo approaches to understand the unresolved low prion susceptibility of canids. Studies based on the amino acid sequence of the canine prion protein (PrP), together with a structural analysis in silico, identified unique key amino acids whose characteristics could orchestrate its high resistance to prion disease. Cell- and brain-based PMCA studies were performed highlighting the relevance of the D163 amino acid in proneness to protein misfolding. This was also investigated by the generation of a novel transgenic mouse model carrying this substitution and these mice showed complete resistance to disease despite intracerebral challenge with three different mouse prion strains (RML, 22L and 301C) known to cause disease in wild-type mice. These findings suggest that dog D163 amino acid is primarily, if not totally, responsible for the prion resistance of canids.


Subject(s)
Canidae/immunology , PrPC Proteins/chemistry , Prion Diseases/veterinary , Amino Acid Sequence , Animals , Antelopes , Brain/pathology , Cats , Cattle , Chiroptera , Deer , Disease Resistance , Dogs , Encephalopathy, Bovine Spongiform/pathology , Mice , Mice, Inbred C57BL , Mice, Transgenic , PrPC Proteins/ultrastructure , Prion Diseases/immunology , Protein Folding , Protein Structure, Quaternary , Rabbits , Sequence Alignment , Sheep , Static Electricity , Xenarthra
9.
J Environ Manage ; 226: 180-186, 2018 Nov 15.
Article in English | MEDLINE | ID: mdl-30119042

ABSTRACT

The parboilization of rice generates 2 L of effluent per kilogram of processed grain. Several methodologies have previously been tested with the aim of reducing the environmental impact of this effluent. The objective of this study was to evaluate the bioremediation of parboiled rice effluent supplemented with sucrose or residual glycerol from the biodiesel during the cultivation of the Saccharomyces boulardii probiotic. In the first stage of the experiment, cultures were grown in orbital shaker, and five media compositions were evaluated: 1) parboiled rice effluent; 2) effluent supplemented with 1% sucrose; 3) effluent supplemented with 3% sucrose; 4) effluent supplemented with 15 g.L-1 of biodiesel glycerol and 5) standard yeast culture medium (YM). The addition of 1% of sucrose generated the most promising results in terms of cell viability, removal of nitrogen, phosphorus and chemical oxygen demand (COD). From these results, four independent cultures were grown in a bioreactor using effluent +1% of sucrose as the medium. This assays generated a mean of 3.8 g.L-1 of biomass, 1.8 × 1011 CFU.L-1, and removal of 74% of COD and 78% of phosphorus. Therefore, the cultivation of Saccharomyces boulardii in parboiled rice effluent supplemented with 1% sucrose may represent a viable method by which the environmental impact of this effluent can be reduced while simultaneously producing probiotic culture for use in animal production.


Subject(s)
Biodegradation, Environmental , Oryza , Probiotics , Saccharomyces boulardii , Animals , Biomass , Waste Management
10.
Sleep Breath ; 21(3): 745-749, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28429178

ABSTRACT

OBJECTIVE: The objectives of the study are to describe sleep habits, fatigue, and sleepiness in Chiclayo's (Peru) bus drivers and explore their relation with traffic accidents. MATERIAL AND METHODS: This is a descriptive cross-sectional study with a non-probability consecutive sampling. The sample size was 126 drivers. Sleepiness was evaluated using the Epworth Sleepiness Scale and sleep hygiene with validated questionnaires. We used a history of traffic accident or a near-traffic accident as an independent variable and applied chi-squared, t, and Mann-Whitney U tests to evaluate initial associations, which were later tested with a multivariate analysis. RESULTS: The mean age was 47.8 ± 9, 7 years, all were male. Twenty-seven (21%) bus drivers drove 10 or more hours per day; twenty-seven (21%) drove 5 or more hours without stopping; and eleven (9%) slept less than 6 h per day. Ninety-three (74%) drivers had fatigue while driving; thirty-one (25%) sleepiness; thirty-six (29%) had an accident or near accident; and (35%) had nodding while driving. Nodding while driving (PR 2.13, IC 1.26-3.59, p < 0.01) and the number of years as a driver (PR 1.03, IC 1.00-1.05, p = 0.02) were associated with an accident or near accident. CONCLUSION: Fatigue, sleepiness, and a history of accident or near accident were frequent. Having had an accident or near accident was significantly associated with nodding while driving and the number of years as a driver in Chiclayo's bus drivers.


Subject(s)
Automobile Driving/psychology , Automobile Driving/statistics & numerical data , Fatigue/epidemiology , Fatigue/psychology , Habits , Sleep , Accidents, Traffic/psychology , Accidents, Traffic/statistics & numerical data , Cross-Sectional Studies , Humans , Male , Middle Aged , Peru/epidemiology , Surveys and Questionnaires
11.
Transfus Apher Sci ; 55(1): 70-83, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27499183

ABSTRACT

Blood has been shown to contain disease-associated misfolded prion protein (PrP(TSE)) in animals naturally and experimentally infected with various transmissible spongiform encephalopathy (TSE) agents, and in humans infected with variant Creutzfeldt-Jakob disease (vCJD). Recently, we have demonstrated PrP(TSE) in extracellular vesicle preparations (EVs) containing exosomes from plasma of mice infected with mouse-adapted vCJD by Protein Misfolding Cyclic Amplification (PMCA). Here we report the detection of PrP(TSE) by PMCA in EVs from plasma of mice infected with Fukuoka-1 (FU), an isolate from a Gerstmann-Sträussler-Scheinker disease patient. We used Tga20 transgenic mice that over-express mouse cellular prion protein, to assay by intracranial injections the level of infectivity in a FU-infected brain homogenate from wild-type mice (FU-BH), and in blood cellular components (BCC), consisting of red blood cells, white blood cells and platelets, plasma EVs, and plasma EVs subjected to multiple rounds of PMCA. Only FU-BH and plasma EVs from FU-infected mice subjected to PMCA that contained PrP(TSE) transmitted disease to Tga20 mice. Plasma EVs not subjected to PMCA and BCC from FU-infected mice failed to transmit disease. These findings confirm the high sensitivity of PMCA for PrP(TSE) detection in plasma EVs and the efficiency of this in vitro method to produce highly infectious prions. The results of our study encourage further research to define the role of EVs and, more specifically exosomes, as blood-borne carriers of PrP(TSE).


Subject(s)
Exosomes/metabolism , Gerstmann-Straussler-Scheinker Disease/blood , Prions/blood , Animals , Creutzfeldt-Jakob Syndrome/blood , Creutzfeldt-Jakob Syndrome/genetics , Exosomes/genetics , Gerstmann-Straussler-Scheinker Disease/genetics , Humans , Mice , Mice, Transgenic , Prions/genetics , Protein Transport/genetics
12.
J Biol Chem ; 289(42): 29247-60, 2014 Oct 17.
Article in English | MEDLINE | ID: mdl-25157106

ABSTRACT

The development of variant Creutzfeldt-Jakob disease (vCJD) in three recipients of non-leukoreduced red blood cells from asymptomatic donors who subsequently developed the disease has confirmed existing concerns about the possible spread of transmissible spongiform encephalopathies (TSEs) via blood products. In addition, the presence of disease-associated misfolded prion protein (PrP(TSE)), generally associated with infectivity, has been demonstrated in the blood of vCJD patients. However, its origin and distribution in this biological fluid are still unknown. Various studies have identified cellular prion protein (PrP(C)) among the protein cargo in human blood-circulating extracellular vesicles released from endothelial cells and platelets, and exosomes isolated from the conditioned media of TSE-infected cells have caused the disease when injected into experimental mice. In this study, we demonstrate the detection of PrP(TSE) in extracellular vesicles isolated from plasma samples collected during the preclinical and clinical phases of the disease from mice infected with mouse-adapted vCJD and confirm the presence of the exosomal marker Hsp70 in these preparations.


Subject(s)
Prion Diseases/metabolism , Prions/metabolism , Animals , Blood Platelets/metabolism , Cells, Cultured , Creutzfeldt-Jakob Syndrome/metabolism , Culture Media, Conditioned/chemistry , Endopeptidase K/chemistry , Exosomes/metabolism , HSP70 Heat-Shock Proteins/metabolism , Immunoglobulin G/chemistry , Methanol/chemistry , Mice , Mice, Inbred C57BL , Nanoparticles/chemistry , Protein Denaturation , Protein Folding
13.
JOP ; 16(2): 159-66, 2015 Mar 20.
Article in English | MEDLINE | ID: mdl-25791549

ABSTRACT

CONTEXT: Late consequences of acute pancreatitis have received little attention. It is controversial whether the pancreas fully recovers after an episode of acute pancreatitis, especially in the presence of necrosis. Therefore, the presence of late pancreatic dysfunction following acute necrotizing pancreatitis is uncertain and there are controversies about how it may affect long-term quality of life. OBJECTIVES: To evaluate pancreatic function and morphology, besides quality of life, in patients with prior acute necrotizing pancreatitis. PATIENTS: Patients who were admitted to our hospital with acute necrotizing pancreatitis in a ten-year interval were identified and thirty-eight survivors were contacted to enroll in the study out of which sixteen patients were included. METHODS: Exocrine function was studied by qualitative fecal fat excretion. Endocrine function was evaluated by oral glucose tolerance test, HOMA-beta and C-peptide. Pancreatic morphology was examined by computed tomography. Quality of life was measured by 36-item short-form health survey. Tests were performed at least twelve months after the index episode of acute necrotizing pancreatitis. RESULTS: The prevalence of pancreatic exocrine insufficiency was 6.2%. Endocrine dysfunction was observed in half the cases, and no association with the extension of necrosis was found. Morphological changes were frequent (62.5%) and more prevalent in those who faced extensive necrosis. Quality of life was considered good, and its impairment was found exclusively in mental health domain, markedly in patients who had alcoholic pancreatitis. There was no correlation between quality of life and prognostic indicators. CONCLUSIONS: Exocrine function and quality of life were preserved in this group of patients. However, endocrine dysfunction and morphological abnormalities were frequent after acute necrotizing pancreatitis. These findings justify a long-term follow-up in order to initiate specific treatment promptly.

14.
Sleep Breath ; 19(1): 109-14, 2015 Mar.
Article in English | MEDLINE | ID: mdl-24619625

ABSTRACT

PURPOSE: The research in obstructive sleep apnea (OSA) may be beneficial from the collaboration between countries and researchers. In this study, we aimed to analyze the scientific research on OSA from 1991 to 2012 and to evaluate the collaboration networks between countries. METHODS: We conducted a bibliometric study in the SCOPUS database. The systematic search was limited to "articles" published from 1991 to 2012. Articles are results of original research; we evaluated the following criteria: number of countries represented, number of authors, number of citations, and journal names. We determined which countries were the most productive (more articles published) and the number of collaborations between these countries. The probability of citation was evaluated using adjusted odds ratios in a logistic regression analysis. RESULTS: We found a total of 6,896 OSA-related articles that had been published in 1,422 journals, 50 % of these articles were concentrated in 41 journals. Of the 74 different countries associated with these articles, the USA had the highest involvement with 23.8 % of all articles published. The probability of citation increased by 1.23 times for each additional author, and by 2.23 times for each additional country represented; these findings were independent of time since publication, journal, or the country of the author. CONCLUSIONS: Scientific production on OSA is increasing with limited international collaboration. The country with the greatest production in this period (1991-2012) was the USA, which concentrated the international collaboration network on OSA. We recommended that articles should be produced with international collaboration to improve the quantity of scientific publications and their chances of publication in high impact journals.


Subject(s)
Bibliometrics , Databases, Bibliographic , Research , Sleep Apnea, Obstructive , Humans , International Cooperation , Publishing
15.
Proc Natl Acad Sci U S A ; 109(13): 5080-5, 2012 Mar 27.
Article in English | MEDLINE | ID: mdl-22416127

ABSTRACT

The ability of prions to infect some species and not others is determined by the transmission barrier. This unexplained phenomenon has led to the belief that certain species were not susceptible to transmissible spongiform encephalopathies (TSEs) and therefore represented negligible risk to human health if consumed. Using the protein misfolding cyclic amplification (PMCA) technique, we were able to overcome the species barrier in rabbits, which have been classified as TSE resistant for four decades. Rabbit brain homogenate, either unseeded or seeded in vitro with disease-related prions obtained from different species, was subjected to serial rounds of PMCA. De novo rabbit prions produced in vitro from unseeded material were tested for infectivity in rabbits, with one of three intracerebrally challenged animals succumbing to disease at 766 d and displaying all of the characteristics of a TSE, thereby demonstrating that leporids are not resistant to prion infection. Material from the brain of the clinically affected rabbit containing abnormal prion protein resulted in a 100% attack rate after its inoculation in transgenic mice overexpressing rabbit PrP. Transmissibility to rabbits (>470 d) has been confirmed in 2 of 10 rabbits after intracerebral challenge. Despite rabbits no longer being able to be classified as resistant to TSEs, an outbreak of "mad rabbit disease" is unlikely.


Subject(s)
Prion Diseases/pathology , Prion Diseases/transmission , Prions/metabolism , Prions/pathogenicity , Animals , Brain/metabolism , Brain/pathology , Disease Resistance , Electrophoresis, Polyacrylamide Gel , Endopeptidase K/metabolism , Humans , Immunohistochemistry , Male , Mice , Mice, Transgenic , Prion Diseases/metabolism , Prions/chemistry , Protein Denaturation , Protein Folding , Rabbits , Species Specificity
16.
Sleep Breath ; 18(3): 467-73, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24249663

ABSTRACT

PURPOSE: To evaluate the intensity of nocturnal hypoxemia associated with sleepiness in Peruvian men with a diagnosis of obstructive sleep apnea (OSA). METHODS: We carried out a secondary data analysis based on a study which includes patients with OSA who were seen in a private hospital in Lima, Peru from 2006 to 2012. We included male adults who had polysomnographic recordings and who answered the Epworth sleepiness scale (ESE). The intensity of nocturnal hypoxemia (oxygen saturation ≤90%) was classified in four new categories: 0, <1, 1 to 10 and >10% total sleep time with nocturnal hypoxemia (NH). When the ESE score was higher than 10, we used the definitions presence or absence of sleepiness. We used Poisson regression models with robust variance to estimate crude and adjusted prevalence ratios (PR) for association between sleepiness and NH. RESULTS: 518 male patients with OSA were evaluated. Four hundred and fifty-two (87%) patients had NH and 262 (51%) had sleepiness. Of the 142 (27.4%) patients who had >10% total sleep time with NH, 98 (69.0%) showed sleepiness and had a greater probability of sleepiness prevalence, with a crude PR of 1.82 (95% CI 1.31-2.53). This association persisted in the multivariate models. CONCLUSIONS: We found an association between NH and sleepiness. Only patients with the major intensity of NH (over 10% of the total sleep time) had a greater probability of sleepiness. This suggests that sleepiness probably occurs after a chronic process and after overwhelming compensatory mechanisms.


Subject(s)
Disorders of Excessive Somnolence/diagnosis , Disorders of Excessive Somnolence/epidemiology , Hypoxia/diagnosis , Hypoxia/epidemiology , Polysomnography , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/epidemiology , Adult , Cross-Sectional Studies , Humans , Male , Middle Aged , Peru , Surveys and Questionnaires
17.
Sleep Breath ; 17(2): 615-20, 2013 May.
Article in English | MEDLINE | ID: mdl-22684855

ABSTRACT

OBJECTIVE: The objective of this study was to determine the frequency of depressive symptoms in Peruvian patients with obstructive sleep apnea/hypopnea (OSAH) and the association between the presence of depressive symptoms and OSAH severity. METHODS: Physical examination, Beck Depression Inventory (BDI), and Epworth Sleepiness Scale (ESS) were applied, and a polysomnography test was performed. RESULTS: Data on 312 patients, 12 % females, 46.1 ± 11.7 years of age, were analyzed. BDI and ESS scores were 8.3 ± 5.7 and 9.8 ± 5.5, respectively. A total of 244 (78 %) patients had OSAH: 27 % of the cases were mild, 23 % were moderate, and 50 % were severe. Eighteen percent of the population had depression. A univariate analysis found a relationship between depressive symptoms and OSAH, as well as with some polysomnographic variables related to OSAH severity. The association between depression and OSAH was not significant in the multivariate analysis. CONCLUSIONS: No association was found between depressive symptoms and OSAH.


Subject(s)
Depressive Disorder/diagnosis , Sleep Apnea, Obstructive/diagnosis , Adult , Cohort Studies , Comorbidity , Cross-Sectional Studies , Depressive Disorder/epidemiology , Depressive Disorder/psychology , Female , Humans , Male , Middle Aged , Multivariate Analysis , Personality Inventory , Polysomnography , Risk Assessment/statistics & numerical data , Sleep Apnea, Obstructive/epidemiology , Sleep Apnea, Obstructive/psychology
18.
Sleep Breath ; 17(3): 1079-86, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23340853

ABSTRACT

PURPOSE: The purpose of this study is to describe the clinical and polysomnographic differences found in patients diagnosed with obstructive sleep apnea-hypopnea (OSAH), with or without excessive daytime sleepiness (EDS) measured by the Epworth Sleepiness Scale (ESS). METHODS: A physical examination, ESS, and polysomnography were applied to all the participants, considering an ESS score of >10 to indicate EDS and an ESS score of ≥ 16 to indicate severe EDS. Univariate (chi-squared or Student's t test) and multivariate (multiple logistic regression) analysis approaches were used. A value of p < .05 was considered statistically significant. RESULTS: The study covered 151 OSAH patients, including 129 (85 %) male patients, 66 (44 %) with EDS and 23 (21 %) with severe EDS. In the univariate analysis of demographic and polysomnographic variables, a comparison between patients without and with EDS showed that the latter had a larger neck circumference, maximum O2 desaturation, and increased sleep time at <90 % O2 saturation, with significant statistical differences. In the multivariate analysis, this statistical significance disappears. A comparison between patients without EDS and with severe EDS did not reveal differences in demographic or polysomnographic variables. CONCLUSIONS: Patients with OSAH and ESD showed more hypoxemia, but we did not find significant differences between OSAH patients with or without EDS.


Subject(s)
Disorders of Excessive Somnolence/diagnosis , Polysomnography , Sleep Apnea, Obstructive/diagnosis , Adult , Body Mass Index , Cohort Studies , Disorders of Excessive Somnolence/therapy , Female , Humans , Male , Middle Aged , Sleep Apnea, Obstructive/therapy , Treatment Outcome
19.
Biologicals ; 40(4): 278-81, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22494953

ABSTRACT

Although numerous operative and immunological advantages accompany aerosol immunization, potential vaccine virus transmission from the aerosol device to vaccine administrators or from aerosol vaccinees to their contacts requires further study. We conducted a clinical and serological follow-up study of vaccine administrators and matched classroom or household contacts of young adults who received the MMR vaccines by aerosol or injection. Differences in incidence of clinical adverse events between vaccinees and contacts were not statistically significant. No seroresponses to any components of MMR vaccine were noted among 25 matched contacts of persons receiving injected vaccines, and only one equivocal seroresponse was noted among 25 matched contacts of aerosol recipients. No seroresponses were observed in 3 persons who administered aerosol vaccine. The composite findings of this study provide additional evidence of the safety of this approach.


Subject(s)
Aerosols , Measles-Mumps-Rubella Vaccine/administration & dosage , Humans
20.
Sleep Breath ; 16(1): 59-69, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21279696

ABSTRACT

PURPOSE: The main purpose of this study was to develop a cross-cultural adaptation of the Epworth Sleepiness Scale for Peruvian population (ESS-VP) and to provide evidence of reliability and validity to this scale. We also modified the ESS-VP for non-driving Peruvian population (ESS-MPV). METHODS: Participants were Peruvians between 18 and 65 years. Five-phase design: Translation and retranslation of the original scale; comprehension evaluation (n = 60); reliability or test-retest (n = 75); internal consistency and construct validity (n = 219); and change of sensibility (n = 36). Just as in the ESS-PV, the same procedure was applied to ESS-MPV except the first phase. RESULTS: The ESS-PV and ESS-MPV had an adequate comprehension. They were reliable over time (test-retest), being better within a period of 2 weeks. They also had adequate internal consistency (Cronbach's alpha: 0.790 and 0.789). Two factors were extracted in both scales, being only the first factor in which all items showed statistically significant loads. Both scales are sensitive to sleepiness change in patients with obstructive sleep apnea during treatment. CONCLUSIONS: The ESS-VP and ESS-MPV, adapted to adult Peruvian population, are comparable to the original scale, reliable, valid, and change-sensitive. It is proposed that the ESS-MPV should be applied in Peruvian population who do not drive motorized vehicles.


Subject(s)
Cross-Cultural Comparison , Disorders of Excessive Somnolence/diagnosis , Sleep Apnea, Obstructive/diagnosis , Surveys and Questionnaires , Adolescent , Adult , Comprehension , Cross-Sectional Studies , Disorders of Excessive Somnolence/epidemiology , Disorders of Excessive Somnolence/therapy , Female , Humans , Male , Middle Aged , Peru , Psychometrics/statistics & numerical data , Reference Values , Reproducibility of Results , Sleep Apnea, Obstructive/epidemiology , Translating , Treatment Outcome , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL