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1.
Chaos ; 34(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38598674

RESUMO

Functional networks have emerged as powerful instruments to characterize the propagation of information in complex systems, with applications ranging from neuroscience to climate and air transport. In spite of their success, reliable methods for validating the resulting structures are still missing, forcing the community to resort to expert knowledge or simplified models of the system's dynamics. We here propose the use of a real-world problem, involving the reconstruction of the structure of flights in the US air transport system from the activity of individual airports, as a way to explore the limits of such an approach. While the true connectivity is known and is, therefore, possible to provide a quantitative benchmark, this problem presents challenges commonly found in other fields, including the presence of non-stationarities and observational noise, and the limitedness of available time series. We explore the impact of elements like the specific functional metric employed, the way of detrending the time series, or the size of the reconstructed system and discuss how the conclusions here drawn could have implications for similar analyses in neuroscience.

2.
Plants (Basel) ; 13(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38337949

RESUMO

Rice (Oryza sativa) varieties are generated through breeding programs focused on local requirements. In Chile, the southernmost rice producer, rice productivity relies on the use and generation of temperate japonica germplasms, which need to be adapted to the intensifying effects of climate change. Advanced biotechnological tools can contribute to these breeding programs; new technologies associated with precision breeding, including gene editing, rely on procedures such as regeneration and gene transfer. In this study, the local rice varieties Platino, Cuarzo, Esmeralda, and Zafiro were evaluated for somatic embryogenesis potential using a process that involved the combined use of auxins and cytokinins. An auxin-based (2,4-D) general medium (2N6) allowed for the induction of embryogenic masses in all the genotypes. After induction, masses required culturing either in N6R (kinetin; Platino) or N6RN (BAP, kinetin, IBA, and 2,4-D; Cuarzo, Esmeralda, and Zafiro) to yield whole plants using regeneration medium (N6F, no hormone). The sprouting rates indicated Platino as the most responsive genotype; for this reason, this variety was evaluated for gene transfer. Fifteen-day-old embryo masses were assayed for Agrobacterium-mediated transformation using the bacterial strain EHA105 harboring pFLC-Myb/HPT/GFP, a modified T-DNA vector harboring a geminivirus-derived replicon. The vector included the green fluorescent protein reporter gene, allowing for continuous traceability. Reporter mRNA was produced as early as 3 d after agroinfiltration, and stable expression of the protein was observed along the complete process. These achievements enable further biotechnological steps in these and other genotypes from our breeding program.

3.
Rev Med Chil ; 151(1): 23-31, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37906743

RESUMO

BACKGROUND: The SARS-CoV-2 pandemic is associated with morbidity, hospitalizations, absenteeism, and mortality among healthcare workers (HCW). AIM: To evaluate the seroconversion rate in HCW exposed to SARS-CoV-2 in the early pandemic phase in 2020 at a regional reference hospital. MATERIAL AND METHODS: One hundred seventy-nine HCW working at a regional hospital were invited to a longitudinal study performed between April-July 2020. A serological analysis by ELISA IgG for viral nucleoprotein and protein S with a secondary analysis by ELISA IgG protein S1/S2 for samples with positive or doubtful result was carried out together with a complementary online survey to inquire about occupational or community exposures to SARS-CoV-2. RESULTS: Two cases with baseline infection were detected (1.1%, one symptomatic and one asymptomatic) and no cases of seroconversion were detected. During the study period, there were 136 patients hospitalized with COVID-19, and regional weekly COVID-19 incidence ranged from 2.7 to 24.4 per 100,000 inhabitants. No SARS-CoV-2 cases were detected by PCR among 27 HCW who consulted for respiratory symptoms in the period. Online surveys confirmed direct care of COVID-19 patients and also detected a high degree of unprotected social interaction at work. CONCLUSIONS: There was no evidence of seroconversion in this group of HCW exposed to the risk of infection by SARS-CoV-2 during the onset of the COVID-19 pandemic. Personal protective equipment and other measures used by the HCW were extremely useful for their protection in the initial phase of the pandemic.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , Pandemias/prevenção & controle , Estudos Longitudinais , Soroconversão , Pessoal de Saúde , Imunoglobulina G
4.
Rev. méd. Chile ; 151(1): 23-31, feb. 2023. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-1515415

RESUMO

BACKGROUND: The SARS-CoV-2 pandemic is associated with morbidity, hospitalizations, absenteeism, and mortality among healthcare workers (HCW). AIM: To evaluate the seroconversion rate in HCW exposed to SARS-CoV-2 in the early pandemic phase in 2020 at a regional reference hospital. MATERIAL AND METHODS: One hundred seventy-nine HCW working at a regional hospital were invited to a longitudinal study performed between April-July 2020. A serological analysis by ELISA IgG for viral nucleoprotein and protein S with a secondary analysis by ELISA IgG protein S1/S2 for samples with positive or doubtful result was carried out together with a complementary online survey to inquire about occupational or community exposures to SARS-CoV-2. RESULTS: Two cases with baseline infection were detected (1.1%, one symptomatic and one asymptomatic) and no cases of seroconversion were detected. During the study period, there were 136 patients hospitalized with COVID-19, and regional weekly COVID-19 incidence ranged from 2.7 to 24.4 per 100,000 inhabitants. No SARS-CoV-2 cases were detected by PCR among 27 HCW who consulted for respiratory symptoms in the period. Online surveys confirmed direct care of COVID-19 patients and also detected a high degree of unprotected social interaction at work. CONCLUSIONS: There was no evidence of seroconversion in this group of HCW exposed to the risk of infection by SARS-CoV-2 during the onset of the COVID-19 pandemic. Personal protective equipment and other measures used by the HCW were extremely useful for their protection in the initial phase of the pandemic.


ANTECEDENTES: La pandemia de SARS-CoV-2 está asociada a morbilidad, hospitalizaciones, ausentismo y mortalidad entre el personal de salud (PS). OBJETIVO: Evaluar la tasa de seroconversión en el PS expuesto al SARS-CoV-2 en la fase pandémica inicial el 2020 en un hospital regional de referencia. MATERIAL Y MÉTODOS: Ciento setenta y nueve trabajadores de la salud fueron invitados a un estudio longitudinal realizado entre abril-julio de 2020. Se efectuó un análisis serológico por ELISA IgG para nucleoproteína viral y proteína S con un análisis secundario por ELISA IgG proteína S1 / S2 para muestras con resultado positivo o dudoso junto a encuestas complementarias en línea para preguntar sobre exposiciones ocupacionales o comunitarias al SARS-CoV-2. RESULTADOS: Se detectaron dos casos con infección basal (1,1%, uno sintomático y uno asintomático) sin casos de seroconversión. Durante el período de estudio, hubo 136 pacientes hospitalizados con COVID-19, y la incidencia semanal regional de COVID-19 osciló entre 2,7 y 24,4 por 100.000 habitantes. No se detectaron casos de SARS-CoV-2 por PCR entre los 27 funcionarios que consultaron por síntomas respiratorios en este período. Las encuestas en línea confirmaron la atención directa de los pacientes con COVID-19 y también detectaron un alto grado de interacción social desprotegida en el trabajo. CONCLUSIONES: No hubo evidencia de seroconversión en un grupo de funcionarios expuestos al riesgo de infección por SARS-CoV-2 durante el inicio de la pandemia de COVID-19. Los equipos de protección personal y otras medidas utilizadas por el PS fueron de suma utilidad para su protección en la fase inicial de la pandemia.


Assuntos
Humanos , SARS-CoV-2 , COVID-19/epidemiologia , Imunoglobulina G , Estudos Longitudinais , Pessoal de Saúde , Pandemias/prevenção & controle , Soroconversão
5.
Comput Struct Biotechnol J ; 20: 3257-3267, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35782747

RESUMO

Human gait is a fundamental activity, essential for the survival of the individual, and an emergent property of the interactions between complex physical and cognitive processes. Gait is altered in many situations, due both to external constraints, as e.g. paced walk, and to physical and neurological pathologies. Its study is therefore important as a way of improving the quality of life of patients, but also as a door to understanding the inner working of the human nervous system. In this review we explore how four statistical physics concepts have been used to characterise normal and pathological gait: entropy, maximum Lyapunov exponent, multi-fractal analysis and irreversibility. Beyond some basic definitions, we present the main results that have been obtained in this field, as well as a discussion of the main limitations researchers have dealt and will have to deal with. We finally conclude with some biomedical considerations and avenues for further development.

6.
Phys Rev E ; 105(4-2): 045310, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35590550

RESUMO

The main motivation of this paper is to introduce the permutation Jensen-Shannon distance, a symbolic tool able to quantify the degree of similarity between two arbitrary time series. This quantifier results from the fusion of two concepts, the Jensen-Shannon divergence and the encoding scheme based on the sequential ordering of the elements in the data series. The versatility and robustness of this ordinal symbolic distance for characterizing and discriminating different dynamics are illustrated through several numerical and experimental applications. Results obtained allow us to be optimistic about its usefulness in the field of complex time-series analysis. Moreover, thanks to its simplicity, low computational cost, wide applicability, and less susceptibility to outliers and artifacts, this ordinal measure can efficiently handle large amounts of data and help to tackle the current big data challenges.

7.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1407808

RESUMO

Resumen Introducción: La pandemia de COVID-19 ha afectado a millones de personas en todo el mundo. La identificación de sujetos infectados ha sido importante para el control. Objetivo: Evaluar el rendimiento de una reacción de polimerasa en cadena (RPC) cuantitativa en tiempo real (en inglés: RT-qPCR) para SARS-CoV-2, utilizando saliva como matriz en comparación con un hisopado nasofaríngeo (HNF). Metodología: Se reclutaron adultos en atención ambulatoria, la mayoría sintomáticos. Fueron estudiadas 530 muestras pareadas de saliva e HNF con RT-qPCR. Resultados: Fueron positivas 59 muestras de HNF y 54 de saliva. La sensibilidad con saliva fue 91%, especificidad 100%, el valor predictor positivo (VPP) 100%, valor predictor negativo (VPN) 98%. El índice Kappa fue de 0,95 y LR-0,08. En promedio, el umbral de ciclo (en inglés cycle threshold-CT) de la saliva fue 3,99 puntos más alto que los de HNF (p < 0,0001) mostrando que la carga viral (CV) es menor en saliva. La carga viral en ambas disminuyó con el tiempo después del inicio de los síntomas. El muestreo de saliva fue preferido por los sujetos en lugar de HNF. Conclusión: Este estudio demuestra que la RPC para SARS-CoV-2 utilizando saliva, es adecuada para el diagnóstico de COVID-19 en adultos ambulatorios, especialmente en la etapa temprana de los síntomas.


Abstract Background: The COVID-19 pandemic has affected millions of people around the world. Part of control strategies is testing a large proportion of the population to identify and isolate the infected subjects. Aim: To evaluate the SARS-CoV-2 detection by the performance of a reverse transcription and quantitative polymerase chain reaction (RT-qPCR) against SARS-CoV-2, using saliva as a matrix compared to a nasopharyngeal swab (NPS) to simplify obtaining a diagnostic sample. Methods: Adults in outpatient care were recruited, 95% of them symptomatic. We studied 530 paired saliva and NPS samples by SARS-CoV-2 RT-qPCR. Results: Fifty-nine individuals tested positive in NPS and 54 in saliva samples. Sensitivity for saliva sample was 91%, specificity 100%, positive predictive value (PPV) 100%, negative predictive value (NPV) 98%. The Kappa index was 0.95 and LR-0.08. On average, the cycle threshold (CT) of saliva was 3.99 points higher than those of NPS (p < 0.0001) showing that viral load (VL) is lower in saliva than in NPS. Viral load in both decreased over the time after onset of symptoms. Saliva sampling was preferred by subjects instead of NPS. Conclusion: This study demonstrates that SARS-CoV-2 RT-qPCR using saliva, even with lower VL, is suitable for the diagnosis of COVID-19 in outpatient adults, especially at early stage of symptoms.

8.
Rev Med Chil ; 149(4): 559-569, 2021 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-34479344

RESUMO

Approximately 5% of COVID-19 patients will have a severe disease requiring invasive or non-invasive mechanical ventilation. In this conditions, sedatives and analgesics are fundamental to promote tolerance, comfort and synchrony with the mechanical ventilator. High and unusual requirements for sedation, analgesics and neuromuscular blockers have been reported in these patients, contributing to prolonged exposure, a high rate of delirium and prolongation of mechanical ventilation. These factors, added to the progressive shortage of these drugs, a high demand for care and less capacity for personalized attention, have created an adverse scenario for their proper and rational use. This paper proposes different pharmacotherapeutic optimization strategies for a rational management of sedation, analgesia and neuromuscular block in critically ill patients with COVID-19, with the therapeutic alternatives available in Chile.


Assuntos
Analgesia , COVID-19 , Chile , Estado Terminal/terapia , Humanos , Hipnóticos e Sedativos , Respiração Artificial , SARS-CoV-2
9.
Rev. méd. Chile ; 149(4): 559-569, abr. 2021. tab, ilus
Artigo em Espanhol | LILACS | ID: biblio-1389495

RESUMO

Approximately 5% of COVID-19 patients will have a severe disease requiring invasive or non-invasive mechanical ventilation. In this conditions, sedatives and analgesics are fundamental to promote tolerance, comfort and synchrony with the mechanical ventilator. High and unusual requirements for sedation, analgesics and neuromuscular blockers have been reported in these patients, contributing to prolonged exposure, a high rate of delirium and prolongation of mechanical ventilation. These factors, added to the progressive shortage of these drugs, a high demand for care and less capacity for personalized attention, have created an adverse scenario for their proper and rational use. This paper proposes different pharmacotherapeutic optimization strategies for a rational management of sedation, analgesia and neuromuscular block in critically ill patients with COVID-19, with the therapeutic alternatives available in Chile.


Assuntos
Humanos , COVID-19 , Analgesia , Respiração Artificial , Chile , Estado Terminal/terapia , SARS-CoV-2 , Hipnóticos e Sedativos
10.
Front Plant Sci ; 12: 791030, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35003180

RESUMO

The woody nature of grapevine (Vitis vinifera L.) has hindered the development of efficient gene editing strategies to improve this species. The lack of highly efficient gene transfer techniques, which, furthermore, are applied in multicellular explants such as somatic embryos, are additional technical handicaps to gene editing in the vine. The inclusion of geminivirus-based replicons in regular T-DNA vectors can enhance the expression of clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) elements, thus enabling the use of these multicellular explants as starting materials. In this study, we used Bean yellow dwarf virus (BeYDV)-derived replicon vectors to express the key components of CRISPR/Cas9 system in vivo and evaluate their editing capability in individuals derived from Agrobacterium-mediated gene transfer experiments of 'Thompson Seedless' somatic embryos. Preliminary assays using a BeYDV-derived vector for green fluorescent protein reporter gene expression demonstrated marker visualization in embryos for up to 33 days post-infiltration. A universal BeYDV-based vector (pGMV-U) was assembled to produce all CRISPR/Cas9 components with up to four independent guide RNA (gRNA) expression cassettes. With a focus on fungal tolerance, we used gRNA pairs to address considerably large deletions of putative grape susceptibility genes, including AUXIN INDUCED IN ROOT CULTURE 12 (VviAIR12), SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTER 4 (VviSWEET4), LESION INITIATION 2 (VviLIN2), and DIMERIZATION PARTNER-E2F-LIKE 1 (VviDEL1). The editing functionality of gRNA pairs in pGMV-U was evaluated by grapevine leaf agroinfiltration assays, thus enabling longer-term embryo transformations. These experiments allowed for the establishment of greenhouse individuals exhibiting a double-cut edited status for all targeted genes under different allele-editing conditions. After approximately 18 months, the edited grapevine plants were preliminary evaluated regarding its resistance to Erysiphe necator and Botrytis cinerea. Assays have shown that a transgene-free VviDEL1 double-cut edited line exhibits over 90% reduction in symptoms triggered by powdery mildew infection. These results point to the use of geminivirus-based replicons for gene editing in grapevine and other relevant fruit species.

11.
Rev. méd. Chile ; 148(11)nov. 2020.
Artigo em Inglês | LILACS | ID: biblio-1389252

RESUMO

ABSTRACT Background: During the first pandemic wave, Covid-19 reached Latin America cities. Aim: To report clinical features and outcomes of a group of patients with Covid-19 admitted to a Chilean regional reference Center. Material and Methods: Cases were identified by a compatible clinical picture and a positive PCR or serological test. Clinical features of patients were retrieved from medical records. Results: Forty-seven adult patients (45 diagnosed by PCR, 2 by serology) were admitted between epidemiological weeks 13 to 33, corresponding to 4.4% of total regional cases. Hospitalization occurred at a median of 10 days after onset of symptoms. Fifty one percent of patients had 60 years or more. Hypertension, obesity and diabetes mellitus were present in 57, 45 and 32 % of cases, respectively. Nineteen percent of patients had no comorbid condition nor were elderly. Two cases were women in their second trimester of pregnancy. Positive IgM or IgM/IgG results obtained by rapid serological testing, had limited sensitivity during the first week (67%). Seventeen patients (36.2%) were transferred to an intensive care unit (ICU) due to respiratory failure. Chest imaging demonstrated a classical COVID-19 pattern in 87%. By univariate analysis, admission to ICU was significantly associated with tachypnea and higher CALL (comorbidity, age, lymphocyte count and lactate dehydrogenase) score. Four patients died (rendering a hospital mortality of 8.5%) and length of stay was ≥ 14 days in 46.8% of patients. By univariate analysis, mortality was associated with immunosuppression and ICU admission. Conclusions: In our regional Center, patients admitted with COVID-19 had usual risk factors and had a prolonged stay. Hospital mortality was associated with immunosuppression and ICU admission.


Antecedentes: Durante la primera ola pandémica, COVID-19 llegó a las ciudades de América Latina. Objetivos: Informar las características clínicas y los resultados asociados a COVID-19 en un grupo de pacientes ingresados en un Centro de referencia regional en el sur de Chile. Material y Métodos: Los casos fueron identificados por un cuadro clínico compatible asociado a RT-PCR positiva o prueba serológica. La información clínica de los pacientes se obtuvo de sus fichas. Resultados: Entre las semanas epidemiológicas 13 y 33 ingresaron 47 pacientes adultos (45 diagnosticados por PCR, 2 por serología), lo que representa el 4,4% del total de casos regionales. La hospitalización se produjo con una mediana de 10 días después del inicio de los síntomas. El 51% de los pacientes tenía 60 años o más. La hipertensión arterial (57,4%), la obesidad (44,7%) y la diabetes mellitus 2 (31,9%) fueron prevalentes, pero el 19% no presentaba comorbilidades ni era un adulto mayor. Dos casos ocurrieron en mujeres embarazadas en el segundo trimestre. Los resultados positivos de IgM o IgM / IgG obtenidos mediante pruebas serológicas rápidas tuvieron una sensibilidad limitada durante la primera semana (66,7%). Diecisiete pacientes (36,2%, grupo crítico) fueron trasladados a UCI por insuficiencia respiratoria. Las imágenes de tórax demostraron un patrón COVID-19 clásico en el 87% de los casos. Por análisis univariado, el ingreso en UCI se asoció significativamente con taquipnea y puntuaciones CALL (comorbidity, age, lymphocyte count and lactate dehydrogenase) elevadas. Cuatro pacientes fallecieron (mortalidad hospitalaria 8,5%) y la estadía hospitalaria fue ≥ 14 días en el 47% de los pacientes. Por análisis univariado la mortalidad se asoció a inmunodepresión y al ingreso a UCI. Conclusiones: En nuestro Centro regional, COVID-19 se asoció a factores de riesgo conocidos y tuvo una estadía prolongada. La mortalidad hospitalaria se asoció con inmunosupresión o ingreso a UCI.


Assuntos
Adulto , Idoso , Feminino , Humanos , Gravidez , COVID-19 , Chile/epidemiologia , Estado Terminal , SARS-CoV-2 , Hospitalização , Unidades de Terapia Intensiva
12.
Rev. méd. Chile ; 148(6): 778-786, jun. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1139371

RESUMO

ABSTRACT Background: Cytomegalovirus (CMV) is an opportunistic infection (OI) in immunosuppressed patients. However, there are no clear cut-off values available for quantitative plasmatic CMV measures (viral load [VL]) to discriminate those with CMV illness from those infected suffering a transient viral reactivation. Aim: To estimate a CMV VL cut-off point that discriminates infected patients and those with CMV related diseases, and to clinically characterize AIDS patients with this OI. Patients and Methods: Retrospective analysis of AIDS patients admitted by any reason between years 2017 and 2019 and who had a positive plasma CMV VL at any titer. Cases were categorized with illness or infected using accepted criteria and the cut-off value was obtained by receiver operating characteristic curve (ROC) analysis. Results: Twelve patients were identified as having a CMV-associated illness and seven with CMV infection. A CMV VL of 3,800 copies/mL had a sensitivity of 91.6% and 100% specificity to discriminate both states. Of the 12 patients with CMV illness, all were in AIDS stage and only five were receiving HIV therapy. Predominant clinical presentations were gastrointestinal (50%), followed by liver involvement (25%) and CMV disease (25%). All patients were treated with ganciclovir or valganciclovir. Ten patients had a favorable response (83.3%), one patient only had a laboratory improvement (8.3%) and one died during treatment (8.3%). Drug toxicity was recorded in nine patients but in only three cases, a dose adjustment was necessary. Conclusions: The predominant clinical manifestation in our series was gastrointestinal. A CMV VL cutoff level of CMV VL of 3,800 copies / mL is useful to discriminate infected patients from those with CMV related disease.


Antecedentes: Citomegalovirus (CMV) es una infección oportunista (IO) en pacientes inmunosuprimidos. Sin embargo, se requieren puntos de corte de carga viral (CV) para discriminar a aquellos con enfermedad por CMV de aquellos infectados que sufren una reactivación viral transitoria. Objetivos: Estimar un punto de corte de la CV de CMV que discrimine a los enfermos de los infectados y, además, caracterizar clínicamente a los pacientes con sida que presentan esta IO. Pacientes y Métodos: Análisis retrospectivo de pacientes con sida hospitalizados por cualquier motivo entre los años 2017 y 2019, y que presentaron un CV de CMV plasmática positiva a cualquier título. Los casos se clasificaron como enfermos utilizando criterios aceptados y el valor de corte se obtuvo mediante análisis de una curva ROC. Resultados: Durante el período de estudio, 12 pacientes fueron identificados con enfermedad asociada al CMV y siete con infección. Una CV de 3.800 copias/ml logró una sensibilidad de 91,6% y una especificidad de 100% para discriminar ambos estados. De los 12 pacientes enfermos, todos estaban en etapa de sida y solo 5 recibían terapia contra el VIH. La presentación clínica predominante fue gastrointestinal (50%) seguida del compromiso hepático (25%) y de la enfermedad por CMV (25%). Todos los pacientes fueron tratados con ganciclovir o valganciclovir. Diez pacientes tuvieron una respuesta favorable (83,3%), uno solo tuvo mejoría de laboratorio (8,3%) y otro paciente falleció durante el tratamiento (8,3%). Nueve pacientes evolucionaron con toxicidad farmacológica, pero en solo 3 casos fue necesario ajustar las dosis. Conclusiones: La forma predominante de presentación de la enfermedad fue gastrointestinal. Un punto de corte de 3.800 copias/ml discrimina pacientes infectados de aquellos con la enfermedad.


Assuntos
Humanos , Síndrome de Imunodeficiência Adquirida/complicações , Síndrome de Imunodeficiência Adquirida/tratamento farmacológico , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/tratamento farmacológico , Antivirais/uso terapêutico , Ganciclovir/uso terapêutico , Estudos Retrospectivos , Carga Viral , Citomegalovirus
13.
Rev Med Chil ; 148(6): 778-786, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33480376

RESUMO

BACKGROUND: Cytomegalovirus (CMV) is an opportunistic infection (OI) in immunosuppressed patients. However, there are no clear cut-off values available for quantitative plasmatic CMV measures (viral load [VL]) to discriminate those with CMV illness from those infected suffering a transient viral reactivation. AIM: To estimate a CMV VL cut-off point that discriminates infected patients and those with CMV related diseases, and to clinically characterize AIDS patients with this OI. PATIENTS AND METHODS: Retrospective analysis of AIDS patients admitted by any reason between years 2017 and 2019 and who had a positive plasma CMV VL at any titer. Cases were categorized with illness or infected using accepted criteria and the cut-off value was obtained by receiver operating characteristic curve (ROC) analysis. RESULTS: Twelve patients were identified as having a CMV-associated illness and seven with CMV infection. A CMV VL of 3,800 copies/mL had a sensitivity of 91.6% and 100% specificity to discriminate both states. Of the 12 patients with CMV illness, all were in AIDS stage and only five were receiving HIV therapy. Predominant clinical presentations were gastrointestinal (50%), followed by liver involvement (25%) and CMV disease (25%). All patients were treated with ganciclovir or valganciclovir. Ten patients had a favorable response (83.3%), one patient only had a laboratory improvement (8.3%) and one died during treatment (8.3%). Drug toxicity was recorded in nine patients but in only three cases, a dose adjustment was necessary. CONCLUSIONS: The predominant clinical manifestation in our series was gastrointestinal. A CMV VL cutoff level of CMV VL of 3,800 copies / mL is useful to discriminate infected patients from those with CMV related disease.


Assuntos
Síndrome de Imunodeficiência Adquirida , Infecções por Citomegalovirus , Síndrome de Imunodeficiência Adquirida/complicações , Síndrome de Imunodeficiência Adquirida/tratamento farmacológico , Antivirais/uso terapêutico , Citomegalovirus , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/tratamento farmacológico , Ganciclovir/uso terapêutico , Humanos , Estudos Retrospectivos , Carga Viral
14.
Rev Med Chil ; 148(11): 1577-1588, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33844763

RESUMO

BACKGROUND: During the first pandemic wave, Covid-19 reached Latin America cities. AIM: To report clinical features and outcomes of a group of patients with Covid-19 admitted to a Chilean regional reference Center. MATERIAL AND METHODS: Cases were identified by a compatible clinical picture and a positive PCR or serological test. Clinical features of patients were retrieved from medical records. RESULTS: Forty-seven adult patients (45 diagnosed by PCR, 2 by serology) were admitted between epidemiological weeks 13 to 33, corresponding to 4.4% of total regional cases. Hospitalization occurred at a median of 10 days after onset of symptoms. Fifty one percent of patients had 60 years or more. Hypertension, obesity and diabetes mellitus were present in 57, 45 and 32 % of cases, respectively. Nineteen percent of patients had no comorbid condition nor were elderly. Two cases were women in their second trimester of pregnancy. Positive IgM or IgM/IgG results obtained by rapid serological testing, had limited sensitivity during the first week (67%). Seventeen patients (36.2%) were transferred to an intensive care unit (ICU) due to respiratory failure. Chest imaging demonstrated a classical COVID-19 pattern in 87%. By univariate analysis, admission to ICU was significantly associated with tachypnea and higher CALL (comorbidity, age, lymphocyte count and lactate dehydrogenase) score. Four patients died (rendering a hospital mortality of 8.5%) and length of stay was ≥ 14 days in 46.8% of patients. By univariate analysis, mortality was associated with immunosuppression and ICU admission. CONCLUSIONS: In our regional Center, patients admitted with COVID-19 had usual risk factors and had a prolonged stay. Hospital mortality was associated with immunosuppression and ICU admission.


Assuntos
COVID-19 , Adulto , Idoso , Chile/epidemiologia , Estado Terminal , Feminino , Hospitalização , Humanos , Unidades de Terapia Intensiva , Gravidez , SARS-CoV-2
15.
Rev Chilena Infectol ; 36(3): 392-395, 2019 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-31859761

RESUMO

We report a case of V. cholerae non-O1 / non-O139 bacteremia in an 81-year-old woman with abdominal pain, fever, vomiting, liquid stools, choluria and jaundice, while visiting a rural area without access to potable water. The identification was made by the MALDI-TOF mass spectrometry technique and subsequently the non-toxigenic non-O1 / non-139 strain was confirmed in the national reference laboratory. The molecular characterization demonstrated the absence of the cholera toxin gene (CTX), and the TCP pilus, however, presented 5 of 6 virulence genes present in an island of homologous pathogenicity named VPaI-7 of V. parahaemolyticus (vcs N2 +, vcs C2 +, vcs V2 +, toxR-, vspD +, T vopF +) and in addition it was positive for hylAy rtxA virulence genes recognized outside the island. This is the first case reported in Chile of a clinical strain of V. cholerae non-O1, non-O139 isolated from blood culture that carries in its genome a homologous segment of the pathogenicity island named VPaI-7 of V. parahaemolyticus, which codifies for a type III secretion system (TTSS) that probably contributes to his virulence.


Assuntos
Bacteriemia , Proteínas de Bactérias/química , Vibrio cholerae não O1/química , Vibrio cholerae/química , Idoso de 80 Anos ou mais , Bacteriemia/etiologia , Proteínas de Bactérias/isolamento & purificação , Cólera/complicações , Cólera/microbiologia , Feminino , Ilhas Genômicas , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Vibrio cholerae/isolamento & purificação , Vibrio cholerae/patogenicidade , Vibrio cholerae não O1/isolamento & purificação , Vibrio cholerae não O1/patogenicidade , Virulência
16.
Phys Rev E ; 100(4-1): 042215, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31770914

RESUMO

In this paper, we introduce a model to describe the decay of the number of unobserved ordinal patterns as a function of the time series length in noisy chaotic dynamics. More precisely, we show that a stretched exponential model fits the decay of the number of unobserved ordinal patterns for both discrete and continuous chaotic systems contaminated with observational noise, independently of the noise level and the sampling time. Numerical simulations, obtained from the logistic map and the x coordinate of the Lorenz system, both operating in a totally chaotic dynamics were used as test beds. In addition, we contrast our results with those obtained from pure stochastic dynamics. The fitting parameters, namely, the stretching exponent and the characteristic decay rate, are used to distinguish whether the dynamical nature of the data sequence is stochastic or chaotic. Finally, the analysis of experimental records associated with the hyperchaotic pulsations of an optoelectronic oscillator allows us to illustrate the applicability of the proposed approach in a practical context.

17.
Rev. chil. infectol ; 36(3): 392-395, jun. 2019. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1013799

RESUMO

Resumen Presentamos un caso de bacteriemia por Vibrio cholerae no-O1/ no-O139 en una mujer de 81 años con un cuadro de dolor abdominal, fiebre, vómitos, diarrea, coluria e ictericia, mientras visitaba una zona rural sin acceso a agua potable. La identificación se realizó por la técnica de espectrometría de masa MALDI-TOF, confirmándose una cepa no toxigénica no-O1/no-139. La caracterización molecular del aislado demostró la ausencia del gen de la toxina del cólera (CTX), y pilus TCP; sin embargo, presentó cinco de los seis genes de virulencia presentes en la isla de patogenicidad homóloga denominada VPaI-7 del V. parahaemolyticus (vcs N2+, vcs C2+, vcs V2+,toxR-, vspD+, T vopF+). Además, el aislado presentó los genes de virulencia hylA y rtxA. Este es el primer caso reportado en Chile de una cepa clínica de V. cholerae no-O1, no-O139 aislada de hemocultivos portador de un segmento homólogo de la isla de patogenicidad denominada VPaI-7 de V. parahaemolyticus, el cual codifica para un sistema de secreción tipo III (TTSS), que probablemente contribuye a su virulencia.


We report a case of V. cholerae non-O1 / non-O139 bacteremia in an 81-year-old woman with abdominal pain, fever, vomiting, liquid stools, choluria and jaundice, while visiting a rural area without access to potable water. The identification was made by the MALDI-TOF mass spectrometry technique and subsequently the non-toxigenic non-O1 / non-139 strain was confirmed in the national reference laboratory. The molecular characterization demonstrated the absence of the cholera toxin gene (CTX), and the TCP pilus, however, presented 5 of 6 virulence genes present in an island of homologous pathogenicity named VPaI-7 of V. parahaemolyticus (vcs N2 +, vcs C2 +, vcs V2 +, toxR-, vspD +, T vopF +) and in addition it was positive for hylAy rtxA virulence genes recognized outside the island. This is the first case reported in Chile of a clinical strain of V. cholerae non-O1, non-O139 isolated from blood culture that carries in its genome a homologous segment of the pathogenicity island named VPaI-7 of V. parahaemolyticus, which codifies for a type III secretion system (TTSS) that probably contributes to his virulence.


Assuntos
Humanos , Feminino , Idoso de 80 Anos ou mais , Proteínas de Bactérias/química , Vibrio cholerae/química , Bacteriemia/etiologia , Vibrio cholerae não O1/química , Proteínas de Bactérias/isolamento & purificação , Vibrio cholerae/isolamento & purificação , Vibrio cholerae/patogenicidade , Virulência , Cólera/complicações , Cólera/microbiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Vibrio cholerae não O1/isolamento & purificação , Vibrio cholerae não O1/patogenicidade , Ilhas Genômicas
18.
Artigo em Inglês | MEDLINE | ID: mdl-31093225

RESUMO

OBJECTIVE: To 1) describe clinical characteristics of adult patients in Chile with severe acute respiratory infections (SARI) associated with influenza viruses, and 2) analyze virus subtypes identified in specimens collected from those patients, hospital resources used in clinical management, clinical evolution, and risk factors associated with a fatal outcome, using observational data from the SARI surveillance network (SARInet). METHODS: Adults hospitalized from 1 July 2011 to 31 December 2015 with influenza-associated SARI at a SARI sentinel surveillance hospital in Santiago were identified and the presence of influenza in all cases confirmed by reverse transcription polymerase chain reaction (RT-PCR), using respiratory samples. RESULTS: A total of 221 patients (mean age: 74.1 years) were hospitalized with influenza-associated SARI during the study period. Of this study cohort, 91.4% had risk factors for complications and 34.3% had been vaccinated during the most recent campaign. Pneumonia was the most frequent clinical manifestation, occurring in 57.0% of the cohort; other manifestations included influenza-like illness, exacerbated chronic bronchitis, decompensated heart failure, and asthmatic crisis. Cases occurred year-round, with an epidemic peak during autumn-winter. Both influenza A (H1N1pdm09 and H3N2) and B virus co-circulated. Critical care beds were required for 26.7% of the cohort, and 19.5% needed ventilatory assistance. Multivariate analysis identified four significant factors associated with in-hospital mortality: 1) being bedridden (adjusted odds ratio (aOR): 22.3; 95% confidence interval (CI): 3.0-164); 2) admission to critical care unit (aOR: 8.9; CI: 1.44-55); 3) Pa02/Fi02 ratio < 250 (aOR: 5.8; CI: 1.02-33); and 4) increased serum creatinine concentration (> 1 mg/dL) (aOR: 5.47; CI: 1.20-24). Seasonal influenza vaccine was identified as a significant protective factor (aOR: 0.14; CI: 0.021-0.90). CONCLUSIONS: Influenza-associated SARI affected mainly elderly patients with underlying conditions. Most patients evolved to respiratory failure and more than one-quarter required critical care beds. Clinical presentation was variable. Death was associated with host characteristics and disease-associated conditions, and vaccine was protective. Virus type did not influence outcome.

19.
Lasers Surg Med ; 51(6): 509-515, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30779363

RESUMO

OBJECTIVE: This PUBA study aimed to assess the efficacy of fractional CO2 laser in the treatment of genitourinary syndrome of menopause (GSM). METHODS: GSM symptoms were assessed before, 1 month after the first session and 1 month after the third session of laser (3 sessions with a 30 days interval between them) in 60 women (median, interquartile range: 55, 49-69). Subjective (visual analog scale) and objective (Vaginal Health Index, VHIS; Vaginal Maturity Index/Frost Index; Spanish Overactive Bladder Questionnaire-Short Form, USMEX Spanish OAB-qSF and Female Sexual Function Index, FSFI) measures were used during the study period to assess CO2 fractionated laser treatment outcomes compared to baseline. RESULTS: Fractional CO2 laser treatment was effective to improve GSM symptoms (vaginal dryness, vaginal itching, vaginal burning, dyspaurenia, dysuria, urinary urgency; P < 0.001) after three sessions, as well as VHIS (median, interquartile range: 13, 10-15 at baseline vs. 21, 20-23 at the fourth month follow up; P < 0.001), Frost Index (median, interquartile range: 28, 24-31 at baseline vs. 8, 6-10 at the fourth month follow up; P < 0.001), USMEX (median, interquartile range: 56, 46-68 at baseline vs 14, 13-16 at the fourth month follow up: P < 0,001) and FSFI (median, interquartile range: 5, 2-14 at baseline vs 30, 28-32). CONCLUSIONS: In this sample, the data suggests that fractionated CO2 laser is an effective alternative for GSM treatment with positive outcomes that persists over time. Lasers Surg. Med. 51:509-515, 2019. © 2019 Wiley Periodicals, Inc.


Assuntos
Doenças Urogenitais Femininas/terapia , Terapia a Laser , Lasers de Gás/uso terapêutico , Menopausa , Idoso , Feminino , Doenças Urogenitais Femininas/etnologia , Doenças Urogenitais Femininas/etiologia , Humanos , Pessoa de Meia-Idade , Peru , Avaliação de Sintomas , Síndrome , Resultado do Tratamento
20.
J Agric Food Chem ; 67(5): 1598-1607, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30632375

RESUMO

Cold storage of fruit is one of the methods most commonly employed to extend the postharvest lifespan of peaches ( Prunus persica (L.) Batsch). However, fruit quality in this species is affected negatively by mealiness, a physiological disorder triggered by chilling injury after long periods of exposure to low temperatures during storage and manifested mainly as a lack of juiciness, which ultimately modifies the organoleptic properties of peach fruit. The aim of this study was to identify molecular components and metabolic processes underlying mealiness in susceptible and nonsusceptible segregants. Transcriptome and qRT-PCR profiling were applied to individuals with contrasting juiciness phenotypes in a segregating F2 population. Our results suggest that mealiness is a multiscale phenomenon, because juicy and mealy fruit display distinctive reprogramming processes affecting translational machinery and lipid, sugar, and oxidative metabolism. The candidate genes identified may be useful tools for further crop improvement.


Assuntos
Frutas/química , Perfilação da Expressão Gênica , Prunus persica/genética , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus persica/química , Prunus persica/metabolismo
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