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1.
Physiol Plant ; 176(5): e14494, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39210540

RESUMO

The balance between the CO2 entry for photosynthesis and transpiration water loss is crucial for plant growth, and ABA signaling can affect this equilibrium. To test how ABA balances plant growth and environmental adaptation, we performed molecular genetics studies in the biotech crop Nicotiana benthamiana under well-watered or drought conditions. Studies on ABA signaling in crops are complicated by the multigenic nature of the PYR/PYL/RCAR ABA receptor family and its functional redundancy, which is particularly challenging in polyploid plants. We have generated a pentuple pyl mutant in the allotetraploid Nicotiana benthamiana through CRISPR/Cas9 gene editing. The pentuple mutant is impaired in 2 NbPYL1-like and 3 NbPYL8-like receptors, affecting the regulation of transpiration and several ABA-dependent transcriptional processes. RNA-seq and metabolite analysis revealed that the synthesis of galactinol, an essential precursor for the osmoprotective raffinose family of oligosaccharides, is ABA-dependent and impaired in the mutant under osmotic stress. In contrast, our results show that, under well-watered conditions, partial inactivation of ABA signaling leads to higher CO2 entry and photosynthesis in the mutant than in WT. Photosynthesis analyses revealed an increased CO2 diffusion capacity mediated by higher stomatal and mesophyll conductances, and higher substomatal CO2 concentration in the pentuple mutant. RNA-seq analyses revealed that genes associated with cell wall loosening (e.g., expansins) and porosity were strongly downregulated by ABA in WT. In summary, a partial relief of the ABA control on transpiration mediated by ABA receptors positively affects photosynthesis when water is not limited, at the expense of reduced water use efficiency.


Assuntos
Ácido Abscísico , Nicotiana , Fotossíntese , Transpiração Vegetal , Transdução de Sinais , Ácido Abscísico/metabolismo , Transpiração Vegetal/fisiologia , Nicotiana/genética , Nicotiana/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Dióxido de Carbono/metabolismo , Mutação
2.
Molecules ; 24(2)2019 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-30669453

RESUMO

New enantiomerically pure C16-alkyl diamides derived from trihydroxy cyclohexane-1,2-dicarboxylic acid have been synthesized from (-)-shikimic acid. The hydroxyl groups in these compounds are free or, alternatively, they present full or partial protection. Their gelling abilities towards several solvents have been tested and rationalized by means of the combined use of Hansen solubility parameters, scanning electron microscopy (SEM), and circular dichroism (CD), as well as computational calculations. All the results allowed us to account for the capability of each type of organogelator to interact with different solvents and for the main mode of aggregation. Thus, compounds with fully protected hydroxyl groups are good organogelators for methanol and ethanol. In contrast, a related compound bearing three free hydroxyl groups is insoluble in water and polar solvents including alcohols but it is able to gelate some low-polarity solvents. This last behavior can be justified by strong hydrogen bonding between molecules of organogelator, which competes advantageously with polar solvent interactions. As an intermediate case, an organogelator with two free hydroxyl groups presents an ambivalent ability to gelate both apolar and polar solvents by means of two aggregation patterns. These involve hydrogen bonding interactions of the unprotected hydroxyl groups in apolar solvents and intermolecular interactions between amide groups in polar ones.


Assuntos
Ácidos Cicloexanocarboxílicos/química , Ácidos Dicarboxílicos/química , Furanos/química , Géis/química , Ligação de Hidrogênio , Modelos Moleculares , Solubilidade , Solventes/química , Estereoisomerismo , Água/química
3.
Molecules ; 22(11)2017 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29165398

RESUMO

Spironucleosides are a type of conformationally restricted nucleoside analogs in which the anomeric carbon belongs simultaneously to the sugar moiety and to the base unit. This locks the nucleic base in a specific orientation around the N-glycosidic bond, imposing restrictions on the flexibility of the sugar moiety. Anomeric spiro-functionalized nucleosides have gained considerable importance with the discovery of hydantocidin, a natural spironucleoside isolated from fermentation broths of Streptomyces hygroscopicus which exhibits potent herbicidal activity. The biological activity of hydantocidin has prompted considerable synthetic interest in this nucleoside and also in a variety of analogues, since important pharmaceutical leads can be found among modified nucleoside analogues. We present here an overview of the most important advances in the synthesis of spironucleosides.


Assuntos
Nucleosídeos/síntese química , Carboidratos/síntese química , Carboidratos/química , Hidantoínas/síntese química , Hidantoínas/química , Nucleosídeos/química
4.
Chemistry ; 23(14): 3357-3365, 2017 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-28005300

RESUMO

Enantiomerically pure C16 -alkyl amides derived from cis and trans cycloalkane-1,2-dicarboxylic acids, respectively, have been synthesized and their behavior as organogelators has been investigated. These compounds include cis/trans diastereomeric cyclobutane and cyclohexane derivatives with the aim to explore the influence of the ring size as well as the relative configuration in their hierarchical self-assembly to form gels. High resolution 1 H NMR spectroscopy studies allowed the determination of the dynamics of the gelation process in [D8 ]toluene and the sol-gel transition temperature. The morphology and size of the aggregates have been investigated and results have shown that, in the case of cyclobutane derivatives, the cis/trans stereochemistry is not relevant for the gelation behavior and the properties of the soft-materials obtained, but it is remarkable for cyclohexane diamides, which are better organogelators. The four compounds produce chiral aggregates despite that two of them are meso achiral molecules. We show herein that this fact is an example of stochastic symmetry breaking induced by sonication. The self-assembly of these molecules has been modelled providing information and support about the structure and the chirality of the aggregates.

5.
Rev Esp Enferm Dig ; 108(4): 226-7, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27065249

RESUMO

We present a case of congenital diaphragmatic hernia diagnosed in an adult. It is a kind of exceptional pathology outside the pediatric age with few cases reported in the literature. Its presentation is unusual, especially in the form of mechanical intestinal obstruction, requiring surgical treatment.


Assuntos
Hérnias Diafragmáticas Congênitas/complicações , Obstrução Intestinal/etiologia , Adulto , Procedimentos Cirúrgicos do Sistema Digestório , Hérnias Diafragmáticas Congênitas/diagnóstico por imagem , Humanos , Obstrução Intestinal/diagnóstico por imagem , Volvo Intestinal/diagnóstico por imagem , Volvo Intestinal/cirurgia , Masculino , Radiografia Torácica , Tomografia Computadorizada por Raios X
7.
Lung ; 188(6): 483-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20922404

RESUMO

The determination of pleural fluid triglycerides (PF-TRIG) is useful in the diagnosis of chylothorax, but its diagnostic value for other causes of pleural effusions is unknown. The aim of this study was to evaluate the usefulness of PF-TRIG in the diagnosis of other pleural effusions and investigate the origin of their increase in these fluids. We studied 390 pleural effusions (75 tuberculous, 107 neoplastic, 39 parapneumonic, 30 miscellaneous, 42 idiopathic, and 97 transudates). The correlation was analyzed with the PF-TRIG values as the dependent variable and serum triglycerides (S-TRIG) and the pleural fluid/serum protein ratio (PF/S PROT ratio) as independent variables. The PF-TRIG was significantly higher in exudates. The sensitivity of PF-TRIG for identifying exudates was 84.3%, specificity 61.9%. The correlation between PF-TRIG and S-TRIG was significant in the exudates and in the total pleural effusions. There was a significant correlation between PF-TRIG and S-TRIG and capillary permeability, which worsened when looking at the transudates and exudates separately. No correlations were found between the PF-TRIG and the number of red cells and white cells in any of the groups. Except for diagnosing a chylothorax, the determination of triglycerides in pleural fluid does not appear to be justified. The cause of the increase in PF-TRIG in exudates could not be established because the correlations obtained were insufficient to be able to predict PF-TRIG values from their serum values and the measurement of capillary permeability.


Assuntos
Quilotórax/diagnóstico , Exsudatos e Transudatos/química , Derrame Pleural/diagnóstico , Triglicerídeos/análise , Adolescente , Adulto , Idoso , Biomarcadores/análise , Permeabilidade Capilar , Quilotórax/etiologia , Quilotórax/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pleural/etiologia , Derrame Pleural/metabolismo , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Tennessee , Triglicerídeos/sangue , Regulação para Cima , Adulto Jovem
8.
Med Clin (Barc) ; 135(4): 145-50, 2010 Jul 03.
Artigo em Espanhol | MEDLINE | ID: mdl-20471043

RESUMO

BACKGROUND AND OBJECTIVE: Early alterations in retinal microcirculation are observed in most hypertensive patients seen in daily practice and the European guidelines consider it is necessary an objective method to quantify these alterations. We have previously described a semi-automatic computerized system to evaluate the calibre of retinal blood vessels that has shown high sensitivity and specificity to calculate the arteriovenous ratio (AVR), though with limitations. We describe a method based on the snakes model to calculate the arteriovenous ratio. PATIENTS AND METHOD: We had compared it with the previously reported lineal method, and we have analyzed 173 digital photographs from 96 hypertensive patients, most of them receiving treatment. Photos were made in two hospitals (A Coruña: 66 and Santiago de Compostela: 107), and were analysed by the same people in each Centre, by the lineal and snake method. RESULTS: We have observed that the arithmetic mean and the differences in AVR between both methods were minimal and showed a normal distribution. Cronbach statistics was 0.974 and intraclass correlation coefficient 0.949 (p<0.001), for the images from Santiago and 0.923 with an intraclass correlation coefficient of 0.857 (p<0.001) for the images from A Coruña. CONCLUSION: This semiautomatic method to calculate the AVR ratio has a high sensitivity and a greater specificity than previous method, and the correlation between the results obtained with both is excellent.


Assuntos
Hipertensão/patologia , Modelos Estatísticos , Vasos Retinianos/patologia , Técnicas de Diagnóstico Oftalmológico , Humanos , Microcirculação
9.
Transl Res ; 155(4): 178-84, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20303466

RESUMO

Pleural fluid (PF) cholesterol is a useful parameter to differentiate between pleural transudates and exudates, although the pathophysiologic mechanisms for its increase in exudates are not fully understood. We aim to elucidate the cause of this increase by analyzing the levels of cholesterol-high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), apolipoprotein A (ApoA), and apolipoprotein B (ApoB)-in PF and blood as well as the number of leucocytes and red cells in the PF. We studied 259 patients with pleural effusion (57 transudates and 202 exudates). The correlations of the pleural and serum (S) levels of these parameters were analyzed, with the pleural cholesterol fractions as the dependent variables and their levels in blood and the pleural/serum protein ratio (P/S prot ratio) as the independent variables. The pleural fluid cholesterol levels (PFCHOL) correlated with their blood levels and the capillary permeability (r=0.885). No significant differences were found between the percentage of LDL, with regard to total cholesterol in the serum [SCHOL], and the same percentage in the exudates, between the PF/S LDL ratio (0.46) and the PF/S CHOL ratio (0.48), or between the PF/S ApoB ratio and the PF/S LDL ratio. The percentage of PF cholesterol bound to HDL and LDL was significantly higher (91.9%) than in the blood (90%). No significant correlations were found between any of the lipids studied and the number of erythrocytes and leucocytes. In conclusion, the PFCHOL may be predicted from the SCHOL, and the capillary permeability may be reflected by the PF/S prot ratio.


Assuntos
Permeabilidade Capilar/fisiologia , Colesterol/metabolismo , Exsudatos e Transudatos/metabolismo , Derrame Pleural/fisiopatologia , Adulto , Idoso , Apolipoproteínas/sangue , Colesterol/sangue , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Derrame Pleural/sangue , Derrame Pleural/etiologia
10.
J Phys Chem B ; 113(29): 9669-80, 2009 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-19555098

RESUMO

There is an increasing interest in the secondary structure of beta-amino-acid-containing peptides, since these compounds exhibit an intrinsic propensity to form stable folds even for short peptides, a feature that is rarely observed in alpha-amino-acid-containing peptides. In this work, we use a multiple trajectory molecular dynamics approach to study a panel of cyclic beta-amino-acid-containing peptides with a variety of motifs that differ in the ring size, ring substituents, and terminal protecting groups. We find a reasonable agreement between the predicted and the experimentally observed structures, in spite of the simple solvent representation used, indicating that in most cases the folding proceeds energetically downhill and it is driven to a great extent by structural preferences coded in the internal degrees of freedom, a result supported by our energy partition analysis. Our results also show that when the N-terminal end is unprotected, it is likely to be charged in a protic polar solvent. In that case, we find that only a molecular dynamics simulation with an "all atom" solvent representation is capable of reproducing the experimentally observed secondary structure of the peptide. Finally, the time evolution analysis of the hydrogen-bond-induced turns as well as of the root-mean-square deviation from the observed structure indicates that some peptides could have a higher intrinsic flexibility than others, within a given fold, a result that correlates to some degree with our molecular mechanics energy analysis.


Assuntos
Aminoácidos Cíclicos/química , Peptídeos Cíclicos/química , Modelos Moleculares , Conformação Molecular , Estrutura Secundária de Proteína , Fatores de Tempo
11.
Rev. cuba. oftalmol ; 18(1): 18-22, ene.-jun. 1995. tab
Artigo em Espanhol | CUMED | ID: cum-5758

RESUMO

Se realizó un estudio prospectivo en 50 enfermos de uveítis anterior aguda con el propósito de describir en los mismos la eosinofilia ocular y en sangre. En el estudio se corrobora que en la totalidad de los casos con sensibilidad alérgica demostrada, aparece eosinofilia ocular y en sangre. Sin embargo, en aquellos en que la etiología fue una colecistopatía con giardiasis crónica asociada, aparece eosinofilia ocular en el 79,0 por ciento. Es destacable que en los pacientes cuya causa fue un poco séptico,toxoplasmosis o enfermedad autoinmune, no se contató eosinofilia. En dicha investigación se valora la importancia del eosinófilo en los pacientes con uveítis anterior aguda, cuya causa probable es alérgica, infecciosa o autoinmunitaria


Assuntos
Eosinofilia/complicações , Eosinofilia/sangue , Túnica Conjuntiva , Uveíte Anterior/complicações , Uveíte Anterior/etiologia
12.
Rev. cuba. oftalmol ; 8(1): 18-22, ene.-jun. 1995. tab
Artigo em Espanhol | LILACS | ID: lil-168931

RESUMO

Se realizo un estudio prospectivo en 50 enfermos de uveitis anterior aguda con el proposito de describir en los mismos la eosinofilia ocular y en sangre. En el estudio se corrobora que en la totalidad de los casos con sensibilidad alergica demostrada, aparece eosinofilia ocular y en sangre. Sin embargo, en aquellos en que la etiologia fue una colecistopatia con giardiasis cronica asociada, aparece eosinofilia ocular en el 79,0 por ciento. Es destacable que en los pacientes cuya causa fue un poco septico,toxoplasmosis o enfermedad autoinmune, no se contato eosinofilia. En dicha investigacion se valora la importancia del eosinofilo en los pacientes con uveitis anterior aguda, cuya causa probable es alergica, infecciosa o autoinmunitaria


Assuntos
Túnica Conjuntiva/metabolismo , Eosinofilia/sangue , Eosinofilia/complicações , Uveíte Anterior/complicações , Uveíte Anterior/etiologia
13.
Alergia (Méx.) ; 40(1): 10-2, ene.-feb. 1993. tab
Artigo em Espanhol | LILACS | ID: lil-134889

RESUMO

Se realizó un estudio prospectivo de 50 pacientes portadores de uveítis anterior aguda con el propósito de confirmar eosinofilia y en sangre. En quienes el factor causal fue una colecistopatía con giardiasis crónica concomitante, se registró eosinofilia ocular en 70 por ciento de los casos. En quienes la causa fue un foco séptico, toxoplasmosis o enfermedad autoinmune, no se comprobó eosinofilia


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Eosinofilia/imunologia , Hipersensibilidade/fisiopatologia , Uveíte Anterior/fisiopatologia , Eosinofilia/diagnóstico , Hipersensibilidade/imunologia , Técnicas Imunológicas , Uveíte Anterior/imunologia
14.
Rev. cuba. oftalmol ; 3(2): 87-97, mayo-ago. 1990. tab
Artigo em Espanhol | CUMED | ID: cum-3850

RESUMO

Se realizó un estudio prospectivo en 50 pacientes que presentaban uveitis anterior aguda con el propósito de describir el comportamiento inmunológico en los mismos. Según nuestros estudios, los pacientes con base alérgica tienen una cierta predisposición a padecer la enfermedad y su intensidad es mayor. Sin embargo, la positividad en los resultados de las pruebas inmunoalérgicas se constatan en pacientes con uveítis anterior aguda donde las enfermedades asociadas modifican las pruebas, ya sea de causa probable o no. Recomendamos continuar estudios en los pacientes con antecedentes alérgicos, con el fin de extremar su atención


Assuntos
Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Humanos , Masculino , Feminino , Uveíte Anterior/imunologia , Estudos Prospectivos
15.
Rev. cuba. oftalmol ; 3(2): 87-97, mayo-ago. 1990. tab
Artigo em Espanhol | LILACS | ID: lil-112055

RESUMO

Se realizó un estudio prospectivo en 50 pacientes que presentaban uveitis anterior aguda con el propósito de describir el comportamiento inmunológico en los mismos. Según nuestros estudios, los pacientes con base alérgica tienen una cierta predisposición a padecer la enfermedad y su intensidad es mayor. Sin embargo, la positividad en los resultados de las pruebas inmunoalérgicas se constatan en pacientes con uveítis anterior aguda donde las enfermedades asociadas modifican las pruebas, ya sea de causa probable o no. Recomendamos continuar estudios en los pacientes con antecedentes alérgicos, con el fin de extremar su atención


Assuntos
Adolescente , Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Estudos Prospectivos , Uveíte Anterior/imunologia
16.
Alergia (Méx.) ; 36(4): 153-9, jul.-ago. 1989. ilus
Artigo em Espanhol | LILACS | ID: lil-88579

RESUMO

Se realizó un estudio prospectivo en 50 pacientes portadores de uveitis anterior aguda con el propósito de describir el comportamiento inmunológico en los mismos. Según nuestros estudios, los papcientes con base alérgica tienen cierta predisposición a padecer esta enfermedad y con intensidad mayor. Sin embargo, la positividad en los resultados de las pruebas inmunoalérgicas se constatan en pacientes portadores de uveitis anterior aguda donde las patologías asociadas modifican las pruebas, ya sea la etiología probable o no. Recomendamos continuar estudios en los pacientes con antecedentes alérgicos, conel fín de extremar su atención


Assuntos
Humanos , Adolescente , Adulto , Pessoa de Meia-Idade , Masculino , Feminino , Uveíte Anterior/imunologia , Portador Sadio , Testes Imunológicos
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