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1.
Front Public Health ; 12: 1384078, 2024.
Article En | MEDLINE | ID: mdl-38645451

Background: The quality assessment of the home-based isolation and care program (HBIC) relies heavily on patient satisfaction and length of stay. COVID-19 patients who were isolated and received HBIC were monitored through telephone consultations (TC), in-person TC visits, and a self-reporting application. By evaluating patient satisfaction and length of stay in HBIC, healthcare providers could gauge the effectiveness and efficiency of the HBIC program. Methods: A cross-sectional study design enrolled 444 HBIC patients who answered a structured questionnaire. A binary logistic regression model assessed the association between independent variables and patient satisfaction. The length of stay in HBIC was analyzed using Cox regression analysis. The data collection started on April (1-30), 2022, in Addis Ababa, Ethiopia. Results: The median age was 34, and 247 (55.6%) were females. A greater proportion (313, 70.5%) of the participants had high satisfaction. Higher frequency of calls (>3 calls) (AOR = 2.827, 95% CI = 1.798, 4.443, p = 0.000) and those who were symptomatic (AOR = 2.001, 95% CI = 1.289, 3.106, p = 0.002) were found to be significant factors for high user satisfaction. Higher frequency of calls (>3 calls) (AHR = 0.537, 95% CI = 0.415, 0.696, p = 0.000) and more in-person visits (>1 visit) (AHR = 0.495, 95% CI = 0.322, 0.762, p = 0.001) had greater chances to reduce the length of stay in the COVID-19 HBIC. Conclusion: 70.5% of the participants had high satisfaction with the system, and frequent phone call follow-ups on patients' clinical status can significantly improve their satisfaction and length of recovery. An in-person visit is also an invaluable factor in a patient's recovery.


COVID-19 , Patient Satisfaction , Telemedicine , Humans , Female , Male , Patient Satisfaction/statistics & numerical data , Adult , Cross-Sectional Studies , Telemedicine/statistics & numerical data , Middle Aged , Ethiopia , Surveys and Questionnaires , Length of Stay/statistics & numerical data , SARS-CoV-2 , Adolescent , Home Care Services/statistics & numerical data , Young Adult , Quarantine , Aged
2.
BMC Genomics ; 25(1): 60, 2024 Jan 15.
Article En | MEDLINE | ID: mdl-38225585

BACKGROUND: Beyond the massive amounts of DNA and genes transferred from the protoorganelle genome to the nucleus during the endosymbiotic event that gave rise to the plastids, stretches of plastid DNA of varying size are still being copied and relocated to the nuclear genome in a process that is ongoing and does not result in the concomitant shrinking of the plastid genome. As a result, plant nuclear genomes feature small, but variable, fraction of their genomes of plastid origin, the so-called nuclear plastid DNA sequences (NUPTs). However, the mechanisms underlying the origin and fixation of NUPTs are not yet fully elucidated and research on the topic has been mostly focused on a limited number of species and of plastid DNA. RESULTS: Here, we leveraged a chromosome-scale version of the genome of the orphan crop Moringa oleifera, which features the largest fraction of plastid DNA in any plant nuclear genome known so far, to gain insights into the mechanisms of origin of NUPTs. For this purpose, we examined the chromosomal distribution and arrangement of NUPTs, we explicitly modeled and tested the correlation between their age and size distribution, we characterized their sites of origin at the chloroplast genome and their sites of insertion at the nuclear one, as well as we investigated their arrangement in clusters. We found a bimodal distribution of NUPT relative ages, which implies NUPTs in moringa were formed through two separate events. Furthermore, NUPTs from every event showed markedly distinctive features, suggesting they originated through distinct mechanisms. CONCLUSIONS: Our results reveal an unanticipated complexity of the mechanisms at the origin of NUPTs and of the evolutionary forces behind their fixation and highlight moringa species as an exceptional model to assess the impact of plastid DNA in the evolution of the architecture and function of plant nuclear genomes.


Genome, Plastid , Moringa oleifera , Moringa oleifera/genetics , Evolution, Molecular , Plastids/genetics , Genome, Plant , DNA, Plant/genetics , Plants/genetics , Cell Nucleus/genetics
3.
Front Plant Sci ; 14: 1099573, 2023.
Article En | MEDLINE | ID: mdl-36844056

Introduction: GoSAMTs play a role in the methylation of polysaccharides synthesized by the Golgi. Pectin homogalacturonan (HG) methyl-esterification is essential for the proper function of this polysaccharide in cell walls. In order to better understand the role of GoSAMTs in HG biosynthesis, we analyzed mucilage methyl-esterification in gosamt mutants. Methods: To determine the function of GoSAMT1 and GoSAMT2 in HG methyl-esterification we utilized epidermal cells of seed coats, as these structures produce mucilage, which is a pectic matrix. We evaluated differences in seed surface morphology and quantified mucilage release. We measured methanol release, and used antibodies and confocal microscopy to analyze HG methyl-esterification in mucilage. Results: We observed morphological differences on the seed surface and delayed, uneven mucilage release in gosamt1-1gosamt2-1 double mutants. We also found changes in the distal wall length indicating abnormal cell wall breakage in this double mutant. Using methanol release and immunolabeling, we confirmed that GoSAMT1 and GoSAMT2 are involved in HG methyl-esterification in mucilage. However, we did not find evidence of decreasing HG in the gosamt mutants. Confocal microscopy analyses detected different patterns in the adherent mucilage and a greater number of low-methyl-esterified domains near the seed coat surface, which correlates with a greater number of "egg-box" structures in this region. We also detected a shift in the partitioning between the Rhamnogalacturonan-I soluble and adherent layers of the double mutant, which correlated with increased amounts of arabinose and arabinogalactan-protein in the adherent mucilage. Discussion: The results show that the HG synthesized in gosamt mutant plants is less methyl esterified, resulting in more egg-box structures, which stiffen the cell walls in epidermal cells and change the rheological properties of the seed surface. The increased amounts of arabinose and arabinogalactan-protein in adherent mucilage, also suggests that compensation mechanisms were triggered in the gosamt mutants.

4.
Front Pediatr ; 10: 1006887, 2022.
Article En | MEDLINE | ID: mdl-36210950

Introduction: Acute bacterial meningitis (ABM) is a public health problem. The disease has reemerged after the introduction of pneumococcal conjugate vaccines (PCVs) due to an increase in serotypes that are not covered. The objective was to determine the changes in the disease incidence before and after the introduction of the 10-valent vaccine (PCV10) in Colombia. Methods: This multicenter study was conducted in 17 hospitals in Colombia. Data were collected from January 2008 to December 2019 in 10 hospitals in Bogotá and from January 2017 to December 2019 in seven hospitals in Cali, Medellín and Cartagena. The data were grouped into three periods: 2008-2011, 2012-2015, and 2016-2019. Results: Of the 706 cases of invasive pneumococcal disease, 81 (11.4%) corresponded to meningitis. The relative incidence in Bogotá in the first period was 0.6 per 100,000 patients ≤ 5 years, decreased to 0.4 per 100,000 patients ≤ 5 years in the second period and increased in the third period to 0.7 per 100,000 patients ≤ 5 years. Serotypes covered by PCV10 decreased from 75 to 9.1%, with Spn19A (31.8%) and Spn34 (13.6%) emerging in the third period. Increased resistance to penicillin (13 to 37%) and to ceftriaxone (5.9 to 16%) was due to the emergence of multidrug-resistant Spn19A. The total mortality rate was 23.5% and increased from 12 to 33%. Conclusions: ABM due to pneumococcus has high morbidity and mortality rates. Reemergence of the disease has been observed due to the inclusion of polymerase chain reaction (PCR) for diagnosis and replacement of circulating serotypes after the introduction of PCV10, with an increase in Spn19A, which causes death and exhibits antimicrobial resistance. Continued surveillance is needed.

5.
Plant Genome ; 15(3): e20238, 2022 09.
Article En | MEDLINE | ID: mdl-35894687

The African Orphan Crops Consortium (AOCC) selected the highly nutritious, fast growing and drought tolerant tree crop moringa (Moringa oleifera Lam.) as one of the first of 101 plant species to have its genome sequenced and a first draft assembly was published in 2019. Given the extensive uses and culture of moringa, often referred to as the multipurpose tree, we generated a significantly improved new version of the genome based on long-read sequencing into 14 pseudochromosomes equivalent to n = 14 haploid chromosomes. We leveraged this nearly complete version of the moringa genome to investigate main drivers of gene family and genome evolution that may be at the origin of relevant biological innovations including agronomical favorable traits. Our results reveal that moringa has not undergone any additional whole-genome duplication (WGD) or polyploidy event beyond the gamma WGD shared by all core eudicots. Moringa duplicates retained following that ancient gamma events are also enriched for functions commonly considered as dosage balance sensitive. Furthermore, tandem duplications seem to have played a prominent role in the evolution of specific secondary metabolism pathways including those involved in the biosynthesis of bioactive glucosinolate, flavonoid, and alkaloid compounds as well as of defense response pathways and might, at least partially, explain the outstanding phenotypic plasticity attributed to this species. This study provides a genetic roadmap to guide future breeding programs in moringa, especially those aimed at improving secondary metabolism related traits.


Moringa oleifera , Chromosomes , Flavonoids , Genome, Plant , Glucosinolates , Moringa oleifera/genetics , Plant Breeding , Polyploidy , Secondary Metabolism
6.
Nat Plants ; 8(6): 656-669, 2022 06.
Article En | MEDLINE | ID: mdl-35681018

Polysaccharide methylation, especially that of pectin, is a common and important feature of land plant cell walls. Polysaccharide methylation takes place in the Golgi apparatus and therefore relies on the import of S-adenosyl methionine (SAM) from the cytosol into the Golgi. However, so far, no Golgi SAM transporter has been identified in plants. Here we studied major facilitator superfamily members in Arabidopsis that we identified as putative Golgi SAM transporters (GoSAMTs). Knockout of the two most highly expressed GoSAMTs led to a strong reduction in Golgi-synthesized polysaccharide methylation. Furthermore, solid-state NMR experiments revealed that reduced methylation changed cell wall polysaccharide conformations, interactions and mobilities. Notably, NMR revealed the existence of pectin 'egg-box' structures in intact cell walls and showed that their formation is enhanced by reduced methyl esterification. These changes in wall architecture were linked to substantial growth and developmental phenotypes. In particular, anisotropic growth was strongly impaired in the double mutant. The identification of putative transporters involved in import of SAM into the Golgi lumen in plants provides new insights into the paramount importance of polysaccharide methylation for plant cell wall structure and function.


Arabidopsis Proteins , Arabidopsis , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Cell Wall/metabolism , Golgi Apparatus/metabolism , Membrane Transport Proteins/metabolism , Methionine/analysis , Methionine/metabolism , Methylation , Pectins/metabolism , Polysaccharides/metabolism
7.
Infectio ; 26(1): 73-77, ene.-mar. 2022. tab
Article Es | LILACS-Express | LILACS | ID: biblio-1350851

Resumen Introducción: las infecciones respiratorias agudas virales se consideran una de las principales causas de mortalidad y morbilidad en pediatría, El Síndrome Respira torio Agudo Severo o Grave 2 (SARS-CoV-2), se ha convertido en un importante problema para la salud pública mundial por su alta transmisibilidad, el objetivo del estudio es describir el comportamiento de los virus respiratorios detectados por RT-PCR en niños hospitalizados por infección respiratoria aguda (IRA) en tiempos de SARS-CoV-2/COVID-19 en un centro de atención pediátrica de Cali-Colombia. Metodología: Estudio observacional de corte transversal retrospectivo, donde se evaluaron 113 pacientes mayores de 28 días y menores de 18 años entre marzo y noviembre del 2020, hospitalizados con diagnostico confirmado IRA y con Reacción en cadena de la polimerasa en tiempo Real (RT-PCR) positiva para virus respiratorios. Resultados: Predominio del género masculino (64.6%). en 74.3% se diagnosticó con IRA baja, los principales síntomas fueron tos en 92% y fiebre 74.3% Se identificó SARS-CoV-2 en 53%, Human Rhinovirus/Enterovirus en 27.41% y Virus Respiratorio Sincitial en 15%. El 34.5% de los pacientes requirieron unidad de cuidados intensivos y 15.9% ventilación mecánica Conclusiones: La infección por SARS-CoV-2 fue más común en los pacientes hospitalizados tanto en salas generales como en la unidad de cuidados intensivos pediátricos


Abstract Introduction: viral acute respiratory infections have been considered of the main causes of mortality and morbidity in pediatrics, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has become an important problem for global public health for its high transmissibility. The objective of the study is to describe the behavior of respiratory viruses detected by RT-PCR in children hospitalized for acute respiratory infection (ARI) in times of SARS-CoV-2 / COVID19 in pediatric care center in Cali Colombia Methodology: observational with a retrospective cross-sectional study. 113 patients older than 28 days and under 18 years in March to November 2020, hospita lized with a confirmed diagnosis of ARI and Real Time Polymerase Chain Reaction (RT-PCR) positive for respiratory viruses. Results: Predominance of gender male 64.6%. 74.3% with a diagnosis of low ARI, main symptoms presented were cough 92% and fever 74.3%, SARS-CoV-2 identified 53%, Human Rhinovirus / Enterovirus 27.41% and Respiratory Syncytial Virus 15%. 34.5% of the patients required an intensive care unit with mechanical ventilation requirement 15.9% Conclusions: infection by SARS-CoV-2 was more common in hospitalized patients in both general wards as in the pediatric intensive care unit.

8.
repert. med. cir ; 31(1): 79-83, 2022. tab.
Article En, Es | LILACS, COLNAL | ID: biblio-1367068

Introducción: Constantin von Economo reportó en 1917 múltiples casos de manifestaciones neurológicas secundarias a la pandemia de la gripe española, clasificándolos en tres grandes grupos: forma somnolienta-oftalmopléjica, mutismo y la hipercinética, con secuelas similares a la enfermedad de Parkinson. Objetivo: presentar un caso de reciente aparición de patología rara en Cali, Colombia con manejo adecuado en unidad de cuidados intensivos (UCI). Presentación del caso: paciente de 9 años con disminución de la fuerza en extremidades, disartria y somnolencia, que inició deterioro neurológico progresivo requiriendo manejo en UCI. El equipo multidisciplinario diagnosticó encefalitis letárgica e iniciaron manejo con plasmaféresis e inmunosupresión con mejoría significativa. Discusión y conclusiones: como la prevalencia es escasa, el diagnóstico exige un alto índice de sospecha como la ocurrencia de un cuadro infeccioso previo al inicio de los síntomas, ya que se considera una reacción autoinmune cruzada contra antígenos de la sustancia nigra. En algunos casos hay alteraciones en los estudios imagenológicos o en citoquímico de líquido cefalorraquídeo. El manejo con pulsos de metilprednisolona y filtración de plasma con plasmaféresis brinda mejoría significativa con disminución de las secuelas a futuro.


Introduction: In 1917, Constantin von Economo reported multiple cases of neurological manifestations secondary to the Spanish flu pandemic. He classified them into three main clinical forms: somnolent-ophthalmoplegic, mutism and hyperkinetic, causing sequelae resembling Parkinson ́s disease. Objective: to present a case of a recent appearance rare disease entity, in Cali Colombia, receiving appropriate management in the Intensive Care Unit (ICU). Case presentation: 9-year-old patient presenting with limb muscle weakness, dysarthria and somnolence, evidencing progressive neurological deterioration requiring admission to the ICU for management. A diagnosis of encephalitis lethargica (EL) was made by the attending multidisciplinary team and management with plasmapheresis and immunosuppression was started, obtaining significant improvement. Discussion and conclusions: as the prevalence is low, the diagnosis requires a high level of suspicion in cases presenting with infectious conditions prior to the development of symptoms, since it is considered an autoimmune cross-reaction against substantia nigra antigens. Alterations in brain imaging or in cerebrospinal fluid cytometry may be found in some cases. Management with methylprednisolone pulse therapy and filtration plasmapheresis provides significant improvement with a decrease in future sequelae.


Humans , Female , Child , Parkinson Disease, Postencephalitic , Encephalitis, St. Louis , Fever , Autoimmunity , Influenza, Human
9.
Rev. mex. anestesiol ; 44(4): 288-299, oct.-dic. 2021. graf
Article Es | LILACS-Express | LILACS | ID: biblio-1347756

Resumen: El arte de la medicina es tan antiguo como el origen mismo de la vida, ha estado implícita en muchas culturas en todo el mundo, iniciando en cada una de ellas como un concepto mágico - religioso, y evolucionando con el paso de los siglos, y la presencia de grandes personajes en los diferentes momentos y culturas, con la aportación de conocimientos y técnicas que hoy han consolidado a la medicina como una ciencia que trasciende y se ha perfeccionado a través de los siglos, para dar lugar a cada una de las especialidades que actualmente conocemos, todas ellas igual de importantes e imprescindibles entre ellas mismas.


Abstract: The art of medicine is as old as the very origin of life, it has been implicit in many cultures around the world, beginning in each of them as a magical-religious concept, and evolving over the centuries, and the presence of great characters in different moments and cultures, with the contribution of knowledge and techniques that today have consolidated medicine as a science that has transcended and has been perfected over the centuries to give rise to each of the specialties that we currently know, all of them equally important and essential among themselves.

10.
Plant Physiol ; 185(3): 914-933, 2021 04 02.
Article En | MEDLINE | ID: mdl-33793913

Rhamnogalacturonan-I biosynthesis occurs in the lumen of the Golgi apparatus, a compartment where UDP-Rhamnose and UDP-Galacturonic Acid are the main substrates for synthesis of the backbone polymer of pectin. Recent studies showed that UDP-Rha is transported from the cytosol into the Golgi apparatus by a family of six UDP-rhamnose/UDP-galactose transporters (URGT1-6). In this study, analysis of adherent and soluble mucilage (SM) of Arabidopsis thaliana seeds revealed distinct roles of URGT2, URGT4, and URGT6 in mucilage biosynthesis. Characterization of SM polymer size showed shorter chains in the urgt2 urgt4 and urgt2 urgt4 urgt6 mutants, suggesting that URGT2 and URGT4 are mainly involved in Rhamnogalacturonan-I (RG-I) elongation. Meanwhile, mutants in urgt6 exhibited changes only in adherent mucilage (AM). Surprisingly, the estimated number of RG-I polymer chains present in urgt2 urgt4 and urgt2 urgt4 urgt6 mutants was higher than in wild-type. Interestingly, the increased number of shorter RG-I chains was accompanied by an increased amount of xylan. In the urgt mutants, expression analysis of other genes involved in mucilage biosynthesis showed some compensation. Studies of mutants of transcription factors regulating mucilage formation indicated that URGT2, URGT4, and URGT6 are likely part of a gene network controlled by these regulators and involved in RG-I synthesis. These results suggest that URGT2, URGT4, and URGT6 play different roles in the biosynthesis of mucilage, and the lack of all three affects the production of shorter RG-I polymers and longer xylan domains.


Arabidopsis Proteins/metabolism , Monosaccharide Transport Proteins/metabolism , Pectins/metabolism , Rhamnogalacturonans/metabolism , Arabidopsis Proteins/genetics , Gene Expression Regulation, Plant , Monosaccharide Transport Proteins/genetics , N-Glycosyl Hydrolases/genetics , N-Glycosyl Hydrolases/metabolism
11.
Int J Infect Dis ; 102: 97-102, 2021 Jan.
Article En | MEDLINE | ID: mdl-33075526

OBJECTIVE: To identify the arbovirus involved in febrile cases identified in a pediatric clinic in Cali, Valle del Cauca province, Colombia, and study the clinical characteristics. METHODS: A descriptive, prospective study enrolled 345 febrile children for 12 months in a pediatric clinic. Medical record registers documenting signs and symptoms, and serum samples were analyzed to detect DENV, CHIKV, and ZIKV by reverse transcription-polymerase chain reaction and serology methods. Diagnosis at the time of admission and discharge were compared based on laboratory test results. RESULTS: All patients were diagnosed as severe dengue at admission. Molecular detection and serology tests identified 143 CHIKV-positive (41.4%), 20 DENV-positive (5.8%), and 123 DENV-CHIKV coinfection patients (35.7%). DENV or CHIKV serology test results of these double-infected patients yield poor performance to confirm patient cases. ZIKV infection was detected in 5 patients (1.4%), every time as double or triple infections. CONCLUSION: . A sustained CHIKV circulation and transmission was confirmed causing febrile illness in children and indicating that this virus spreads even during the regular DENV season, leading to double infections and altering clinical symptoms. Specific clinical tests are necessary to closely identify the arbovirus involved in causing infectious diseases that can help in better treatment and mosquito-transmitted virus surveillance.


Chikungunya Fever/epidemiology , Chikungunya virus/isolation & purification , Dengue Virus/isolation & purification , Dengue/epidemiology , Disease Outbreaks , Adolescent , Animals , Chikungunya Fever/complications , Child , Child, Preschool , Coinfection , Colombia/epidemiology , Dengue/complications , Female , Humans , Infant , Male , Prospective Studies , Serologic Tests
12.
Front Plant Sci ; 11: 594544, 2020.
Article En | MEDLINE | ID: mdl-33363558

Nucleotide sugar transporters (NSTs) are Golgi-localized proteins that play a role in polysaccharide biosynthesis by transporting substrates (nucleotide sugars) from the cytosol into the Golgi apparatus. In Arabidopsis, there is an NST subfamily of six members, called URGTs, which transport UDP-rhamnose and UDP-galactose in vitro. URGTs are very similar in protein sequences, and among them, URGT1 and URGT2 are highly conserved in protein sequence and also showed very similar kinetic parameters toward UDP-rhamnose and UDP-galactose in vitro. Despite the similarity in sequence and in vitro function, mutants in urgt1 led to a specific reduction in galactose in rosette leaves. In contrast, mutants in urgt2 showed a decrease in rhamnose content in soluble mucilage from seeds. Given these specific and quite different chemotypes, we wonder whether the differences in gene expression could explain the observed differences between the mutants. Toward that end, we analyzed whether URGT2 could rescue the urgt1 phenotype and vice versa by performing a promoter swapping experiment. We analyzed whether the expression of the URGT2 coding sequence, controlled by the URGT1 promoter, could rescue the urgt1 rosette phenotype. A similar strategy was used to determine whether URGT1 could rescue the urgt2 mucilage phenotype. Expression analysis of the swapped genes, using qRT-PCR, was similar to the native URGT1 and URGT2 genes in wild-type plants. To monitor the protein expression of the swapped genes, both URGTs were tagged with green fluorescent protein (GFP). Confocal microscopy analyses of the swapped lines containing URGT2-GFP showed fluorescence in motile dot-like structures in rosette leaves. Swapped lines containing URGT1-GFP showed fluorescence in dot-like structures in the seed coat. Finally, the expression of URGT2 in urgt1 mutants rescued galactose reduction in rosette leaves. In the same manner, the expression of URGT1 in urgt2 mutants recovered the content of rhamnose in soluble mucilage. Hence, our results showed that their expression in different organs modulates the role in vivo of URGT1 and URGT2. Likely, this is due to their presence in different cellular contexts, where other proteins, acting in partnership, may drive their functions toward different pathways.

13.
Sci Rep ; 10(1): 17646, 2020 10 19.
Article En | MEDLINE | ID: mdl-33077763

It is necessary to identify suitable alternative crops to ensure the nutritional demands of a growing global population. The genome of Moringa oleifera, a fast-growing drought-tolerant orphan crop with highly valuable agronomical, nutritional and pharmaceutical properties, has recently been reported. We model here gene family evolution in Moringa as compared with ten other flowering plant species. Despite the reduced number of genes in the compact Moringa genome, 101 gene families, grouping 957 genes, were found as significantly expanded. Expanded families were highly enriched for chloroplastidic and photosynthetic functions. Indeed, almost half of the genes belonging to Moringa expanded families grouped with their Arabidopsis thaliana plastid encoded orthologs. Microsynteny analysis together with modeling the distribution of synonymous substitutions rates, supported most plastid duplicated genes originated recently through a burst of simultaneous insertions of large regions of plastid DNA into the nuclear genome. These, together with abundant short insertions of plastid DNA, contributed to the occurrence of massive amounts of plastid DNA in the Moringa nuclear genome, representing 4.71%, the largest reported so far. Our study provides key genetic resources for future breeding programs and highlights the potential of plastid DNA to impact the structure and function of nuclear genes and genomes.


Gene Duplication/genetics , Genome, Plant/genetics , Moringa oleifera/genetics , Plastids/genetics , Evolution, Molecular , Genes, Plant/genetics , Phylogeny , Sequence Alignment , Synteny/genetics
14.
Rev. colomb. quím. (Bogotá) ; 48(2): 40-45, mayo-ago. 2019. tab, graf
Article Es | LILACS-Express | LILACS | ID: biblio-1013968

Resumen Desde el punto de vista científico y tecnológico ha habido un gran interés en el uso de monosustituyentes de furano y tiofeno como polímeros conductores, debido a sus múltiples aplicaciones como OLED, amplificadores ópticos, nanotecnología, entre otros. Por ello, el propósito de este trabajo fue estudiar los aspectos teóricos que afectan las propiedades electroconductoras de este tipo de moléculas. Se determinaron teóricamente los aspectos estructurales y electrónicos que influyeron en la conductividad de copolímeros de furano-tiofeno monosustituidos, al utilizar grupos carboxilos, metilos, hidroxilos, ciano y fluoruros como sustituyentes en el carbono C3 y C10 de cada heterociclo. La diferencia de energía entre el LUMO y el HOMO (band gap, Eg) y el potencial de ionización (PI) fue calculada a partir de las geometrías optimizadas en DFT para el estado neutro, anión y catión. Los PI y la Eg de los copolímeros fueron obtenidos mediante la extrapolación de los valores del oligómero a (1/N) y de una cadena de longitud infinita (1/N=0), obteniéndose una correlación lineal (R=0,99), la cual se mantiene a lo largo de todos los modelos de ajuste de cada copolímero analizado en el estudio.


Abstract There has been great scientific and technological interest in the use of mono-substituents of furan and thiophene as conducting polymers due to their multiple applications such as OLED, optical amplifiers and nanotechnology, among others. For this, the purpose of this work was to study the theoretical aspects that affect the electroconductive properties of this type of molecules. The structural and electronic properties that influence the conductivity of mono substituted-furan-thiophene copolymers were determined theoretically. The effect of using carboxyl, methyl, hydroxyl, cyano, and fluoride groups as substituents on the carbon C3 and C10 of each heterocycle was observed. The energy difference between the LUMO and the HOMO (band gap, Eg) and the ionization potential (IP) were calculated from the geometries optimized in DFT for the neutral, anion and cation state. The PI and Eg of the copolymers were obtained by extrapolating the values of the oligomer a (1/N) and a chain of infinite length (1/N=0) for which a linear correlation was obtained (R=0.99). This correlation is maintained throughout all the adjustment models of each copolymer analyzed in the study.


Resumo Existe muito interesse os termos científicos e tecnológicos em utilizar substituintes mono-substituídos furano e tiofeno como polímeros condutores devido às suas múltiplas aplicações, tais como OLED, amplificadores ópticos e nanotecnologia, entre outros. O objetivo deste trabalho foi estudar os aspectos teóricos que afetam as propriedades eletrocondutoras deste tipo de moléculas. Neste contribuição os aspectos estruturais e electrónicas que influenciam a condutividade de copolímeros furano-tiofeno substituos mono teoricamente determinada observando o efeito do uso de grupos carboxilo, metilo, hidroxilo, ciano e fluoretos como substituintes em C3 e C10 de carbono de cada heterociclo. A diferença de energia entre o LUMO e o HOMO (intervalo de banda, Eg) e o potencial de ionização (IP) foram calculadas a partir das geometrias optimizadas de DFT para o estado neutro, anião e catião. O PI e o Eg dos copolímeros foram obtidos por extrapolação dos valores do oligómero (1/N) e extrapolando para uma cadeia de comprimento infinito (1/ N=0) para os quais uma correlação linear foi obtida (R=0,99), que é mantido ao longo de todos os modelos de ajuste de cada copolímero analisados no estudo.

15.
J Exp Bot ; 70(19): 5071-5088, 2019 10 15.
Article En | MEDLINE | ID: mdl-31145803

Upon imbibition, epidermal cells of Arabidopsis thaliana seeds release a mucilage formed mostly by pectic polysaccharides. The Arabidopsis mucilage is composed mainly of unbranched rhamnogalacturonan-I (RG-I), with low amounts of cellulose, homogalacturonan, and traces of xylan, xyloglucan, galactoglucomannan, and galactan. The pectin-rich composition of the mucilage and their simple extractability makes this structure a good candidate to study the biosynthesis of pectic polysaccharides and their modification. Here, we characterize the mucilage phenotype of a mutant in the UDP-rhamnose/galactose transporter 2 (URGT2), which exhibits a reduction in RG-I and also shows pleiotropic changes, suggesting the existence of compensation mechanisms triggered by the lack of URGT2. To gain an insight into the possible compensation mechanisms activated in the mutant, we performed a transcriptome analysis of developing seeds using RNA sequencing (RNA-seq). The results showed a significant misregulation of 3149 genes, 37 of them (out of the 75 genes described to date) encoding genes proposed to be involved in mucilage biosynthesis and/or its modification. The changes observed in urgt2 included the up-regulation of UAFT2, a UDP-arabinofuranose transporter, and UUAT3, a paralog of the UDP-uronic acid transporter UUAT1, suggesting that they play a role in mucilage biosynthesis. Mutants in both genes showed changes in mucilage composition and structure, confirming their participation in mucilage biosynthesis. Our results suggest that plants lacking a UDP-rhamnose/galactose transporter undergo important changes in gene expression, probably to compensate modifications in the plant cell wall due to the lack of a gene involved in its biosynthesis.


Arabidopsis Proteins/genetics , Arabidopsis/genetics , Monosaccharide Transport Proteins/genetics , Plant Mucilage/biosynthesis , Transcriptome , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Monosaccharide Transport Proteins/metabolism , Mutation
16.
Plant Cell ; 31(8): 1913-1929, 2019 08.
Article En | MEDLINE | ID: mdl-31126981

Because they suck phloem sap and act as vectors for phytopathogenic viruses, aphids pose a threat to crop yields worldwide. Pectic homogalacturonan (HG) has been described as a defensive element for plants during infections with phytopathogens. However, its role during aphid infestation remains unexplored. Using immunofluorescence assays and biochemical approaches, the HG methylesterification status and associated modifying enzymes during the early stage of Arabidopsis (Arabidopsis thaliana) infestation with the green peach aphid (Myzus persicae) were analyzed. Additionally, the influence of pectin methylesterase (PME) activity on aphid settling and feeding behavior was evaluated by free choice assays and the Electrical Penetration Graph technique, respectively. Our results revealed that HG status and HG-modifying enzymes are significantly altered during the early stage of the plant-aphid interaction. Aphid infestation induced a significant increase in total PME activity and methanol emissions, concomitant with a decrease in the degree of HG methylesterification. Conversely, inhibition of PME activity led to a significant decrease in the settling and feeding preference of aphids. Furthermore, we demonstrate that the PME inhibitor AtPMEI13 has a defensive role during aphid infestation, since pmei13 mutants are significantly more susceptible to M. persicae in terms of settling preference, phloem access, and phloem sap drainage.


Aphids/pathogenicity , Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Arabidopsis/parasitology , Pectins/metabolism , Animals , Arabidopsis/enzymology , Arabidopsis Proteins/genetics , Gene Expression Regulation, Plant
17.
Plant Cell ; 29(1): 129-143, 2017 01.
Article En | MEDLINE | ID: mdl-28062750

UDP-glucuronic acid (UDP-GlcA) is the precursor of many plant cell wall polysaccharides and is required for production of seed mucilage. Following synthesis in the cytosol, it is transported into the lumen of the Golgi apparatus, where it is converted to UDP-galacturonic acid (UDP-GalA), UDP-arabinose, and UDP-xylose. To identify the Golgi-localized UDP-GlcA transporter, we screened Arabidopsis thaliana mutants in genes coding for putative nucleotide sugar transporters for altered seed mucilage, a structure rich in the GalA-containing polysaccharide rhamnogalacturonan I. As a result, we identified UUAT1, which encodes a Golgi-localized protein that transports UDP-GlcA and UDP-GalA in vitro. The seed coat of uuat1 mutants had less GalA, rhamnose, and xylose in the soluble mucilage, and the distal cell walls had decreased arabinan content. Cell walls of other organs and cells had lower arabinose levels in roots and pollen tubes, but no differences were observed in GalA or xylose contents. Furthermore, the GlcA content of glucuronoxylan in the stem was not affected in the mutant. Interestingly, the degree of homogalacturonan methylation increased in uuat1 These results suggest that this UDP-GlcA transporter plays a key role defining the seed mucilage sugar composition and that its absence produces pleiotropic effects in this component of the plant extracellular matrix.


Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Golgi Apparatus/metabolism , Nucleotide Transport Proteins/metabolism , Polysaccharides/metabolism , Seeds/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Cell Wall/genetics , Cell Wall/metabolism , Gene Expression Regulation, Plant , Immunoblotting , Microscopy, Confocal , Mutation , Nucleotide Transport Proteins/genetics , Pectins/metabolism , Plants, Genetically Modified , Seeds/genetics , Uridine Diphosphate Sugars/metabolism
18.
Rev. chil. pediatr ; 87(1): 48-52, feb. 2016. ilus, tab
Article Es | LILACS | ID: lil-779474

Introducción: El Streptococcus pneumoniae (S. pneumoniae), también denominado neumococo, es una de las principales bacterias asociadas a mortalidad en menores de 2 años, con una incidencia de morbimortalidad variable de acuerdo a la demografía y exposición a factores protectores o de riesgo. Objetivo: Caracterizar los pacientes fallecidos por enfermedad neumocóccica invasiva (ENI) entre el 2008-2014 en la población infantil de 8 instituciones de salud en Bogotá, Colombia. Pacientes y método: Estudio observacional descriptivo tipo serie de casos, en pacientes fallecidos por ENI, mayores de 28 días hasta los 18 años, en 8 instituciones de tercer nivel de atención en Bogotá, Colombia. Periodo del estudio del 1 de enero de 2008 al 15 de enero de 2014. Tamaño de la muestra: 239 pacientes. Resultados: Se revisaron 239 casos registrados de ENI, presentando una mortalidad del 7,5% (n = 18). La edad promedio de los pacientes que fallecieron fue de 43,7 meses, con un rango de edad entre 2 y 176 meses (14 años); el 66% de los casos era de sexo masculino. Se identificaron serotipos en 8 pacientes, encontrando: 6A, 6B, 10A, 14, 18C, 23B, 23F, 35B. La presentación clínica más frecuente de los casos de mortalidad fue meningitis con el 33% (6 casos), seguida por bacteriemia sin foco en el 28% (5 casos) y neumonía con el 27% (5 casos). Se presentaron situaciones clínicas combinadas como neumonía y meningitis en el 11% (2 casos). Dos de los pacientes tenían factores de riesgo para ENI claramente documentados (asplenia y enfermedad respiratoria crónica). Conclusiones: La mortalidad por ENI es especialmente alta en los menores de 2 años y en pacientes de sexo masculino, especialmente cuando presenta foco meníngeo (44%). La serotipificación no fue posible en todos los pacientes fallecidos, ya que no se envió la cepa aislada al Instituto Nacional de Salud. Se requiere una vigilancia continua y sistemática para evaluar el impacto de la vacunación y las posibles modificaciones en el patrón de presentación de la enfermedad.


Introduction: Streptococcus pneumoniae (S. pneumoniae), also known as pneumococcus, is one of the main bacteria associated with mortality in children under 2 years of age, with a morbidity and mortality incidence that varies according to demographics and exposure to risk, or protective factors. Objective: To describe the child mortality due to invasive pneumococcal disease (IPD) between 2008 -2014 (6 years), in 8 Medical Centres in Bogotá, Colombia. Patients and method: Descriptive observational case series of patients who died of IPD, aged 28 days to 18 years, in 8 tertiary care institutions in Bogota, Colombia. The study period was from 1 January 2008 to 15 January 2014. Sample size: 239 patients. Results: A total of 239 registered cases of IPD were reviewed, showing a mortality of 8% (n 18). The mean age of patients that died was 43.7 months, with an age range from 2 to 176 months (14 years), with 66% of the cases being male. Serotypes were identified in 8 patients, finding: 6A, 6B, 10A, 14, 18C, 23B, 23F, and 35B. The most common clinical presentation of the cases was meningitis with mortality of 33% (6 cases), followed by bacteraemia without focus in 28% (5 cases), and pneumonia with 27% (5 cases). Combined clinical situations were presented, such as pneumonia and meningitis in 11% (2 cases). Two of the patients had clearly documented risk factors for IPD (asplenia and chronic respiratory disease). Conclusions: IPD mortality is particularly high in children under 2 years in male patients, especially when presented with a meningeal focus (44%). Serotyping was not possible in all patients who died, since no strain isolated was sent to the National Institute of Health. Continuous and systematic vigilance is required to evaluate the impact of vaccination and possible changes in the pattern of presentation of disease.


Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Pneumonia, Pneumococcal/mortality , Streptococcus pneumoniae/isolation & purification , Bacteremia/mortality , Meningitis, Pneumococcal/mortality , Pneumonia, Pneumococcal/epidemiology , Serotyping , Sex Factors , Incidence , Retrospective Studies , Risk Factors , Bacteremia/microbiology , Bacteremia/epidemiology , Colombia/epidemiology , Meningitis, Pneumococcal/epidemiology
19.
Rev Chil Pediatr ; 87(1): 48-52, 2016.
Article Es | MEDLINE | ID: mdl-26627694

INTRODUCTION: Streptococcus pneumoniae (S. pneumoniae), also known as pneumococcus, is one of the main bacteria associated with mortality in children under 2 years of age, with a morbidity and mortality incidence that varies according to demographics and exposure to risk, or protective factors. OBJECTIVE: To describe the child mortality due to invasive pneumococcal disease (IPD) between 2008 -2014 (6 years), in 8 Medical Centres in Bogotá, Colombia. PATIENTS AND METHOD: Descriptive observational case series of patients who died of IPD, aged 28 days to 18 years, in 8 tertiary care institutions in Bogota, Colombia. The study period was from 1 January 2008 to 15 January 2014. SAMPLE SIZE: 239 patients. RESULTS: A total of 239 registered cases of IPD were reviewed, showing a mortality of 8% (n 18). The mean age of patients that died was 43.7 months, with an age range from 2 to 176 months (14 years), with 66% of the cases being male. Serotypes were identified in 8 patients, finding: 6A, 6B, 10A, 14, 18C, 23B, 23F, and 35B. The most common clinical presentation of the cases was meningitis with mortality of 33% (6 cases), followed by bacteraemia without focus in 28% (5 cases), and pneumonia with 27% (5 cases). Combined clinical situations were presented, such as pneumonia and meningitis in 11% (2 cases). Two of the patients had clearly documented risk factors for IPD (asplenia and chronic respiratory disease). CONCLUSIONS: IPD mortality is particularly high in children under 2 years in male patients, especially when presented with a meningeal focus (44%). Serotyping was not possible in all patients who died, since no strain isolated was sent to the National Institute of Health. Continuous and systematic vigilance is required to evaluate the impact of vaccination and possible changes in the pattern of presentation of disease.


Bacteremia/mortality , Meningitis, Pneumococcal/mortality , Pneumonia, Pneumococcal/mortality , Streptococcus pneumoniae/isolation & purification , Adolescent , Bacteremia/epidemiology , Bacteremia/microbiology , Child , Child, Preschool , Colombia/epidemiology , Female , Humans , Incidence , Infant , Infant, Newborn , Male , Meningitis, Pneumococcal/epidemiology , Pneumonia, Pneumococcal/epidemiology , Retrospective Studies , Risk Factors , Serotyping , Sex Factors
20.
Infectio ; 17(1): 43-47, ene.-mar. 2013. ilus
Article Es | LILACS, COLNAL | ID: lil-698773

Resumen El ectima gangrenoso es una infección poco frecuente de la piel, conocida con una característica lesión causada principalmente por la Pseudomoma aeruginosa, pero que también se puede presentar por otro tipo de bacterias del tipo Staphylococcus aureus o el Streptococcus beta hemolítico del grupo A ( S. beta hemolítico del grupo A), entre otros. Esta entidad se asocia frecuentemente con inmunodeficiencias primarias y secundarias. Las lesiones, clínicamente, se presentan como máculas eritematovioláceas, descamativas que rápidamente evolucionan a papulovesículas, ampollas hemorrágicas y costrosas que dejan unas úlceras profundas en sacabocado con fondo necrótico. La mortalidad es alta, entre 40 y 75% de los individuos inmunológicamente comprometidos. Se describe el caso de una niña de 5 años que inicialmente presentó varicela y luego una sobreinfección por S. aureus ocasionando un cuadro clínico de un ectima gangrenoso; al diagnóstico se llega por la clínica, cultivos y biopsias de piel. Se realizó manejo con aciclovir, clindamicina y cefepime endovenoso, con buena y rápida respuesta de la paciente.


Abstract Ecthyma gangrenosum (EG) is a rare infection of the skin, known as a characteristic lesion caused by Pseudomoma aeruginosa , but also can occur from other types of bacteria like Staphylococcus aureus or beta hemolytic group, among others. This condition is often associated with primary and secondary immunodeficiencies. The lesions present clinically as scaly, erythematous violacious macules that rapidly evolve into papule-vesicles, bleeding and crusty blisters leaving a deep punch ulcer with a necrotic base. Mortality is high, between 40% and 75% of immunologically compromised individuals. We describe the case of a girl of 5 years of age who initially presented chickenpox and then superinfection with Staphylococcus aureus, causing a clinical picture of EG. The diagnosis was reached based on symptoms, cultures and skin biopsies. Management was achieved with acyclovir, intravenous clindamycin and cefepime, with a good and quick response by the patient.


Humans , Female , Child, Preschool , Superinfection , Chickenpox , Ecthyma , Gangrene , Skin Diseases , Bacteria , Soft Tissue Infections
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