RESUMO
Geminiviruses have genomes composed of single-stranded DNA molecules and encode a rolling-circle replication (RCR) initiation protein ("Rep"), which has multiple functions. Rep binds to specific repeated DNA motifs ("iterons"), which are major determinants of virus-specific replication. The particular amino acid (aa) residues that determine the preference of a geminivirus Rep for specific iterons (i.e., the trans-acting replication "specificity determinants", or SPDs) are largely unknown, but diverse lines of evidence indicate that most of them are closely associated with the so-called RCR motif I (FLTYP), located in the first 12-19 aa residues of the protein. In this work, we characterized two strains of a novel begomovirus, rhynchosia golden mosaic Sinaloa virus (RhGMSV), that were incompatible in replication in pseudorecombination experiments. Systematic comparisons of the Rep proteins of both RhGMSV strains in the DNA-binding domain allowed the aa residues at positions 71 and 74 to be identified as the residues most likely to be responsible for differences in replication specificity. Residue 71 is part of the ß-5 strand structural element, which was predicted in previous studies to contain Rep SPDs. Since the Rep proteins encoded by both RhGMSV strains are identical in their first 24 aa residues, where other studies have mapped potential SPDs, this is the first study lending direct support to the notion that geminivirus Rep proteins contain separate SPDs in their N-terminal domain.
Assuntos
Begomovirus/classificação , Begomovirus/metabolismo , Proteínas Virais/metabolismo , Replicação Viral/fisiologia , Sequência de Aminoácidos , Begomovirus/genética , Clonagem Molecular , Fabaceae/virologia , Genoma Viral , Filogenia , Folhas de Planta/virologia , Conformação Proteica , Vírus Reordenados , Nicotiana/virologia , Proteínas Virais/genética , Replicação Viral/genéticaRESUMO
The compounds I (Z)-2-(phenyl)-3-(2,4,5-trimethoxyphenyl)acrylonitrile with one side (2,4,5-MeO-), one symmetrical (2Z,2'Z)-2,2'-(1,4-phenylene)bis(3-(2,4,5-trimethoxyphenyl)acrylonitrile), II (both sides with (2,4,5-MeO-), and three positional isomers with pyridine (Z)-2-(pyridin-2- 3, or 4-yl)-3-(2,4,5-trimethoxyphenyl)acrylonitrile, III-V were synthetized and characterized by UV-Vis, fluorescence, IR, H1-NMR, and EI mass spectrometry as well as single crystal X-ray diffraction (SCXRD). The optical properties were strongly influenced by the solvent (hyperchromic and hypochromic shift), which were compared with the solid state. According to the solvatochromism theory, the excited-state (µe) and ground-state (µg) dipole moments were calculated based on the variation of Stokes shift with the solvent's relative permittivity, refractive index, and polarity parameters. SCXRD analyses revealed that the compounds I and II crystallized in the monoclinic system with the space group, P21/n and P21/c, respectively, and with Z = 4 and 2. III, IV, and V crystallized in space groups: orthorhombic, Pbca; triclinic, P-1; and monoclinic, P21 with Z = 1, 2, and 2, respectively. The intermolecular interactions for compounds I-V were investigated using the CCDC Mercury software and their energies were quantified using PIXEL. The density of states (DOS), molecular electrostatic potential surfaces (MEPS), and natural bond orbitals (NBO) of the compounds were determined to evaluate the photophysical properties.
RESUMO
Since all forms of mimicry are based on perceptual deception, the sensory ecology of the intended receiver is of paramount importance to test the necessary precondition for mimicry to occur, that is, model-mimic misidentification, and to gain insight in the origin and evolutionary trajectory of the signals. Here we test the potential for aggressive mimicry by a group of coral reef fishes, the color polymorphic Hypoplectrus hamlets, from the point of view of their most common prey, small epibenthic gobies and mysid shrimp. We build visual models based on the visual pigments and spatial resolution of the prey, the underwater light spectrum and color reflectances of putative models and their hamlet mimics. Our results are consistent with one mimic-model relationship between the butter hamlet H. unicolor and its model the butterflyfish Chaetodon capistratus but do not support a second proposed mimic-model pair between the black hamlet H. nigricans and the dusky damselfish Stegastes adustus. We discuss our results in the context of color morphs divergence in the Hypoplectrus species radiation and suggest that aggressive mimicry in H. unicolor might have originated in the context of protective (Batesian) mimicry by the hamlet from its fish predators rather than aggressive mimicry driven by its prey.
RESUMO
Experimental and theoretical insights into the nature of intermolecular interactions and their effect on optical properties of 1-allyl-4-(1-cyano-2-(4-dialkylaminophenyl)vinyl)pyridin-1-ium bromide salts (I and II) are reported. A comparison of optical properties in solution and in the solid-state of the salts (I and II) with their precursors (Ia and IIa) is made. The experimental absorption maxima (λmax) in CHCl3 is at 528â nm for I and at 542â nm for II, and a strong bathochromic shift of â¼110â nm is observed for salts I and II compared with their precursors. The absorption bands in solid-state at â¼627â nm for I and at â¼615â nm for II that are assigned to charge transfer (CT) effect. The optical properties and single crystal structural features of I and II are explored by experimental and computational tools. The calculated λmax and the CT are in good agreement with the experimental results. The intermolecular interactions existing in the crystal structures and their energies are quantified for various dimers by PIXEL, QTAIM and DFT approaches. Three types of interactions, (i) the cationâ â â cation interactions, (ii) cationâ â â anion interactions and (iii) anionâ â â anion interactions are observed. The cationic moiety is mainly destabilized by C-Hâ â â N/π and πâ â â π interactions whereas the cation and anion moiety is predominantly stabilized by strong C-Hâ â â Br- interactions in both structures. The existence of charge transfer between cation and anion moieties in these structures is established through NBO analysis.
RESUMO
In this work, a study of the photophysical properties in different solvents and at different pH values of a luminogenic compound with a donor-π-acceptor (D-π-A) structure was carried out. The compound (Z)-3-(4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl)-2-phenylacrylonitrile (2) was synthesized and characterized by SCXRD, FT-IR, 1H NMR, 13C NMR, EIMS, UV-Vis absorption and fluorescence. The SCXRD characterization reveals a monoclinic system, P21/c, with Z = 4 and an imidazole core having hydrogen bonding with respect to water molecules present in the asymmetric unit. It leads to a strong π-π-interaction in the solid state. The fluorescence λ max emission of the powder and thin film was observed at 563 nm and 540 nm respectively. Several degrees of positive solvatochromic fluorescence were observed due to different molecular conformations in various solvents. When the pH of the compound was changed with HCl or NaOH, a shift in the wavelength of emission was observed in a reversible manner. At pH 2, the λ max of emission was at 541 nm whereas at pH 14 there were two emissions at 561 nm and 671 nm. Due to their good emission in the solid state, compound 2 was tested as an emitting layer in OLEDs; the devices showed an acceptable performance with a luminance average of 450 cd m-2. The band gap was analyzed by optical absorption, cyclic voltammetry measurement and DFT calculations.
RESUMO
2-(4-((2-Hydroxyethyl)(methyl)amino)benzylidene)malononitrile (HEMABM) was synthesized from 4-[hydroxymethyl(methyl)amino]benzaldehyde and propanedinitrile to obtain a low molecular weight fluorescent material with an efficient solid-state emission and electroluminescence properties comparable to the well-known poly(2-methoxy-5(2'-ethyl)hexoxyphenylenevinylene) (MEH-PPV). The HEMABM was used to prepare an organic light-emitting diode by a solution process. Despite the title compound being a small molecule, it showed optical properties and notable capacity to form a film with smooth morphology (10.81 nm) closer to that of polymer MEH-PPV (10.63 nm). The preparation of the device was by spin coating, the electrical properties such as threshold voltage were about 1.0 V for both HEMABM and MEH-PPV, and the luminance 1300 cd m-2 for HEMABM and 2600 cd m-2 for MEH-PPV. This low molecular weight compound was characterized by SCXRD, IR, NMR, and EI. Besides a quantitative analysis of the intermolecular interactions by PIXEL, density functional theory (DFT) calculations are reported.
RESUMO
Reversible decreases in synaptic strength, known as short-term depression (STD), are widespread in neural circuits. Various computational roles have been attributed to STD but these tend to focus upon the initial depression rather than the subsequent recovery. We studied the role of STD and recovery at an excitatory synapse between the fast extensor tibiae (FETi) and flexor tibiae (flexor) motor neurons in the desert locust (Schistocerca gregaria) by making paired intracellular recordings in vivo. Over behaviorally relevant pre-synaptic spike frequencies, we found that this synapse undergoes matched frequency-dependent STD and recovery; higher frequency spikes that evoke stronger, faster STD also produce stronger, faster recovery. The precise matching of depression and recovery time constants at this synapse ensures that flexor excitatory post-synaptic potential (EPSP) amplitude encodes the presynaptic FETi interspike interval (ISI). Computational modelling shows that this precise matching enables the FETi-flexor synapse to linearly encode the ISI in the EPSP amplitude, a coding strategy that may be widespread in neural circuits.
Assuntos
Transtorno Depressivo/fisiopatologia , Membro Posterior/fisiologia , Neurônios Motores/fisiologia , Sinapses/fisiologia , Animais , Simulação por Computador , Gafanhotos/fisiologia , Humanos , Somação de Potenciais Pós-Sinápticos/fisiologiaRESUMO
BACKGROUND: There is limited information about the use of antithrombotic therapies and outcomes of Latin American (LatAm) subjects with atrial fibrillation. The global ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation Atrial Fibrillation-Thrombolysis In Myocardial Infarction 48) trial compared the efficacy and safety of edoxaban versus warfarin over a median follow-up of 2.8 years. OBJECTIVES: The authors aimed to compare adjusted outcomes in Latin America versus outside Latin America and to compare outcomes stratified by anticoagulant treatment and region. METHODS: The authors analyzed clinical characteristics and outcomes, adjusted for baseline characteristics, the Human Development Index, and randomized treatment of 2,661 LatAm versus 18,444 non-Latin American subjects (nLAS). RESULTS: When compared with nLAS, LatAm subjects had a similar overall risk for stroke. After multivariate adjustment, the risks of stroke/systemic embolism (hazard ratio [HR]: 1.19; 95% confidence interval (CI): 0.96 to 1.47; p = 0.11) and major bleeding (HR: 1.10; 95% CI: 0.89 to 1.36; p = 0.39) were similar in LatAm and nLAS. LatAm subjects were at higher adjusted risk of death (HR: 1.48; 95% CI: 1.30 to 1.69; p < 0.001) and intracranial hemorrhage (ICH) (HR: 1.55; 95% CI: 1.00 to 2.41; p = 0.049). In both regions, when compared with warfarin, edoxaban reduced stroke/systemic embolism (HR: 0.64 and 0.91 in LatAm and nLAS, respectively), major bleeding (HR: 0.71 and 0.82), and cardiovascular death (HR: 0.78 and 0.88), without evidence of regional heterogeneity (pint = 0.41, 0.50, and 0.70, respectively). There was a greater reduction in hemorrhagic stroke with edoxaban in LatAm (HR: 0.16) than in nLAS (HR: 0.64; pint = 0.037). CONCLUSIONS: After multivariable adjustment, LatAm subjects with atrial fibrillation had higher rates of intracranial hemorrhage and death than nLAS. Outcomes with higher-dose edoxaban versus warfarin were at least as favorable in LatAm subjects as in nLAS, with an even greater reduction in hemorrhagic stroke seen in LatAm.
Assuntos
Anticoagulantes/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Inibidores do Fator Xa/uso terapêutico , Piridinas/uso terapêutico , Tiazóis/uso terapêutico , Varfarina/uso terapêutico , Idoso , Método Duplo-Cego , Embolia/epidemiologia , Embolia/prevenção & controle , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Hemorragias Intracranianas/epidemiologia , América Latina/epidemiologia , Masculino , Infarto do Miocárdio/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controleRESUMO
BACKGROUND: Lorcaserin, a selective serotonin 2C receptor agonist that modulates appetite, has proven efficacy for weight management in overweight or obese patients. The cardiovascular safety and efficacy of lorcaserin are undefined. METHODS: We randomly assigned 12,000 overweight or obese patients with atherosclerotic cardiovascular disease or multiple cardiovascular risk factors to receive either lorcaserin (10 mg twice daily) or placebo. The primary safety outcome of major cardiovascular events (a composite of cardiovascular death, myocardial infarction, or stroke) was assessed at an interim analysis to exclude a noninferiority boundary of 1.4. If noninferiority was met, the primary cardiovascular efficacy outcome (a composite of major cardiovascular events, heart failure, hospitalization for unstable angina, or coronary revascularization [extended major cardiovascular events]) was assessed for superiority at the end of the trial. RESULTS: At 1 year, weight loss of at least 5% had occurred in 1986 of 5135 patients (38.7%) in the lorcaserin group and in 883 of 5083 (17.4%) in the placebo group (odds ratio, 3.01; 95% confidence interval [CI], 2.74 to 3.30; P<0.001). Patients in the lorcaserin group had slightly better values with respect to cardiac risk factors (including blood pressure, heart rate, glycemic control, and lipids) than those in the placebo group. During a median follow-up of 3.3 years, the rate of the primary safety outcome was 2.0% per year in the lorcaserin group and 2.1% per year in the placebo group (hazard ratio, 0.99; 95% CI, 0.85 to 1.14; P<0.001 for noninferiority); the rate of extended major cardiovascular events was 4.1% per year and 4.2% per year, respectively (hazard ratio, 0.97; 95% CI, 0.87 to 1.07; P=0.55). Adverse events of special interest were uncommon, and the rates were generally similar in the two groups, except for a higher number of patients with serious hypoglycemia in the lorcaserin group (13 vs. 4, P=0.04). CONCLUSIONS: In a high-risk population of overweight or obese patients, lorcaserin facilitated sustained weight loss without a higher rate of major cardiovascular events than that with placebo. (Funded by Eisai; CAMELLIA-TIMI 61 ClinicalTrials.gov number, NCT02019264 .).
Assuntos
Fármacos Antiobesidade/uso terapêutico , Benzazepinas/uso terapêutico , Doenças Cardiovasculares/complicações , Hipoglicemia/induzido quimicamente , Obesidade/tratamento farmacológico , Sobrepeso/tratamento farmacológico , Redução de Peso/efeitos dos fármacos , Idoso , Fármacos Antiobesidade/efeitos adversos , Insuficiência da Valva Aórtica/induzido quimicamente , Benzazepinas/efeitos adversos , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Hipertensão Pulmonar/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Sobrepeso/complicações , Fatores de RiscoRESUMO
BACKGROUND: Obesity is a well-recognized risk factor for insulin resistance and type 2 diabetes (T2D), although the precise mechanisms underlying the relationship remain unknown. In this study we identified alterations of DNA methylation influencing T2D pathogenesis, in subcutaneous and visceral adipose tissues, liver, and blood from individuals with obesity. METHODS: The study included individuals with obesity, with and without T2D. From these patients, we obtained samples of liver tissue (n = 16), visceral and subcutaneous adipose tissues (n = 30), and peripheral blood (n = 38). We analyzed DNA methylation using Illumina Infinium Human Methylation arrays, and gene expression profiles using HumanHT-12 Expression BeadChip Arrays. RESULTS: Analysis of DNA methylation profiles revealed several loci with differential methylation between individuals with and without T2D, in all tissues. Aberrant DNA methylation was mainly found in the liver and visceral adipose tissue. Gene ontology analysis of genes with altered DNA methylation revealed enriched terms related to glucose metabolism, lipid metabolism, cell cycle regulation, and response to wounding. An inverse correlation between altered methylation and gene expression in the four tissues was found in a subset of genes, which were related to insulin resistance, adipogenesis, fat storage, and inflammation. CONCLUSIONS: Our present findings provide additional evidence that aberrant DNA methylation may be a relevant mechanism involved in T2D pathogenesis among individuals with obesity.
Assuntos
Metilação de DNA , Diabetes Mellitus Tipo 2/genética , Gordura Intra-Abdominal/metabolismo , Fígado/metabolismo , Obesidade/genética , Adipogenia , Adulto , Índice de Massa Corporal , Ilhas de CpG , Epigênese Genética , Ontologia Genética , Estudo de Associação Genômica Ampla , Humanos , Resistência à Insulina , Metabolismo dos Lipídeos , Pessoa de Meia-Idade , TranscriptomaRESUMO
Abstract: Objective: To evaluate efficacy and safety of 60 mg and 120 mg Fimasartan (FMS) alone or combined with 12.5 mg hydrochlorothiazide (HCTZ) in a Mexican population. Methods: A six month, treat-to-target, open study was conducted on subjects with grade 1-2 hypertension. The subjects were initially treated with 60 mg FMS once daily. In week 8, those with Diastolic Blood Pressure (DBP) <90 mmHg continued on the same FMS dose during the rest of the study, while those with DBP ≥90 mmHg were randomised to either 120 mg FMS or 60 mg FMS + 12.5 mg HCTZ once daily. In week 12, randomised subjects with DBP ≥90 mmHg received 120 mg FMS + 12.5 mg HCTZ, while those achieving target continued with their assigned treatment until the end of the study. Results: FMS 60 mg (n = 272) decreased both DBP and Systolic Blood Pressure (SBP) by 11.3 ± 8.9 (p<.0001) and 16.0 ± 14.1 (p<.0001) mmHg, respectively, with 75.4% of subjects reaching the treatment target. Subjects assigned to FMS 120 mg, FMS 60 mg + HCTZ 12.5 mg, or FMS 120 mg + HCTZ 12.5 mg once daily, showed significant reductions in DBP and SBP with their assigned treatment. At the end of the study, 237/272 subjects (87.1%) achieved a DBP < 90 mmHg and an SBP<140 mmHg. The most frequently reported adverse reactions included headache (3.7%), dry mouth (1.1%), transient liver enzyme increase (1.1%), and dizziness (0.7%). Conclusion: Fimasartan is safe and effective in Mexican subjects with grade 1-2 essential hypertension.
Resumen: Objetivo: Evaluar la eficacia y la seguridad de 60 y 120 mg de fimasartán (FMS) solo o combinado con 12.5 mg de hidroclorotiazida (HCTZ) en población mexicana. Métodos: Estudio abierto, de 24 semanas, con tratamiento escalado hasta el objetivo terapéutico en sujetos hipertensos grados 1-2. Tratamiento inicial: FMS 60 mg una vez al día; en la semana 8, los sujetos con presión arterial diastólica (PAD) <90 mmHg mantuvieron su tratamiento inicial durante el estudio, mientras que los sujetos con PAD ≥90 mmHg fueron aleatorizados a 120 mg de FMS o a 60 mg de FMS + 12.5 mg de HCTZ. En la semana 12, los sujetos aleatorizados con PAD ≥90 mmHg recibieron 120 mg de FMS + 12.5 mg de HCTZ; quienes alcanzaron el objetivo terapéutico mantuvieron su tratamiento asignado hasta finalizar el estudio. Resultados: FMS 60 mg (n = 272) disminuyó la PAD y la presión arterial sistólica (PAS) en 11.3 ± 8.9 (p < 0.0001) y 16.0 ± 14.1 (p < 0.0001) mmHg, respectivamente, con logro del objetivo de tratamiento en el 75.4% de los sujetos. Los sujetos asignados a 120 mg de FMS, a 60 mg de FMS + 12.5 mg de HCTZ 12.5 y a 120 mg de FMS + 12.5 mg de HCTZ mostraron reducciones significativas de PAD y PAS; al final del estudio, 237/272 sujetos (87.1%) lograron PAD <90 y PAS <140 mmHg. Las reacciones adversas más frecuentemente reportadas fueron: cefalea (3.7%), boca seca (1.1%), incremento de enzimas hepáticas (1.1%) y mareo (0.7%). Conclusión: FMS es seguro y eficaz en sujetos mexicanos con hipertensión esencial de grados 1-2.
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Pirimidinas/administração & dosagem , Tetrazóis/administração & dosagem , Compostos de Bifenilo/administração & dosagem , Hipertensão Essencial/tratamento farmacológico , Hidroclorotiazida/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Pirimidinas/efeitos adversos , Tetrazóis/efeitos adversos , Compostos de Bifenilo/efeitos adversos , Índice de Gravidade de Doença , Estudos Prospectivos , Resultado do Tratamento , Quimioterapia Combinada , México , Anti-Hipertensivos/efeitos adversosRESUMO
OBJECTIVE: To evaluate efficacy and safety of 60mg and 120mg Fimasartan (FMS) alone or combined with 12.5mg hydrochlorothiazide (HCTZ) in a Mexican population. METHODS: A six month, treat-to-target, open study was conducted on subjects with grade 1-2 hypertension. The subjects were initially treated with 60mg FMS once daily. In week 8, those with Diastolic Blood Pressure (DBP) <90mmHg continued on the same FMS dose during the rest of the study, while those with DBP ≥90mmHg were randomised to either 120mg FMS or 60mg FMS + 12.5mg HCTZ once daily. In week 12, randomised subjects with DBP ≥90mmHg received 120mg FMS+12.5mg HCTZ, while those achieving target continued with their assigned treatment until the end of the study. RESULTS: FMS 60mg (n=272) decreased both DBP and Systolic Blood Pressure (SBP) by 11.3±8.9 (p<.0001) and 16.0±14.1 (p<.0001)mmHg, respectively, with 75.4% of subjects reaching the treatment target. Subjects assigned to FMS 120mg, FMS 60mg+HCTZ 12.5mg, or FMS 120mg+HCTZ 12.5mg once daily, showed significant reductions in DBP and SBP with their assigned treatment. At the end of the study, 237/272 subjects (87.1%) achieved a DBP<90mmHg and an SBP<140mmHg. The most frequently reported adverse reactions included headache (3.7%), dry mouth (1.1%), transient liver enzyme increase (1.1%), and dizziness (0.7%). CONCLUSION: Fimasartan is safe and effective in Mexican subjects with grade 1-2 essential hypertension.
Assuntos
Anti-Hipertensivos/administração & dosagem , Compostos de Bifenilo/administração & dosagem , Hipertensão Essencial/tratamento farmacológico , Hidroclorotiazida/administração & dosagem , Pirimidinas/administração & dosagem , Tetrazóis/administração & dosagem , Anti-Hipertensivos/efeitos adversos , Compostos de Bifenilo/efeitos adversos , Quimioterapia Combinada , Hipertensão Essencial/classificação , Feminino , Humanos , Hidroclorotiazida/efeitos adversos , Masculino , México , Pessoa de Meia-Idade , Estudos Prospectivos , Pirimidinas/efeitos adversos , Índice de Gravidade de Doença , Tetrazóis/efeitos adversos , Resultado do TratamentoRESUMO
Extensive studies of vertebrates have shown that brain size scales to body size following power law functions. Most animals are substantially smaller than vertebrates, and extremely small animals face significant challenges relating to nervous system design and function, yet little is known about their brain allometry. Within a well-defined monophyletic taxon, Formicidae (ants), we analyzed how brain size scales to body size. An analysis of brain allometry for individuals of a highly polymorphic leaf-cutter ant, Atta colombica, shows that allometric coefficients differ significantly for small (<1.4 mg body mass) versus large individuals (b = 0.6003 and 0.2919, respectively). Interspecifically, allometric patterns differ for small (<0.9 mg body mass) versus large species (n = 70 species). Using mean values for species, the allometric coefficient for smaller species (b = 0.7961) is significantly greater than that for larger ones (b = 0.669). The smallest ants had brains that constitute â¼15% of their body mass, yet their brains were relatively smaller than predicted by an overall allometric coefficient of brain to body size. Our comparative and intraspecific studies show the extent to which nervous systems can be miniaturized in taxa exhibiting behavior that is apparently comparable to that of larger species or individuals.
Assuntos
Formigas/anatomia & histologia , Encéfalo/anatomia & histologia , Animais , Formigas/fisiologia , Tamanho Corporal/fisiologia , Peso Corporal , Classificação , Análise Numérica Assistida por ComputadorRESUMO
AIM: To assess the time to obtain reliable oxygen saturation readings by different pulse oximeters during neonatal resuscitation in the delivery room or NICU. METHODS: Prospective study comparing three different pulse oximeters: Masimo Radical-7 compared simultaneously with Ohmeda Biox 3700 or with Nellcor N395, in newborn infants who required resuscitation. Members of the research team placed the sensors for each of the pulse oximeters being compared simultaneously, one sensor on each foot of the same baby. Care provided routinely, without interference by the research team. The time elapsed until a reliable SpO2 was obtained was recorded using a digital chronometer. Statistical comparisons included chi-square and student's T-test. RESULTS: Thirty-two infants were enrolled; median gestational age 32 weeks. Seventeen paired measurements were made with the Radical-7 and Biox 3700; mean time to a stable reading was 20.2±7 sec for the Radical-7 and 74.2±12 sec for the Biox 3700 (p=0.02). The Radical-7 and the N- 395 were paired on 15 infants; the times to obtain a stable reading were 20.9±4 sec and 67.3±12 sec, respectively (p=0.03). CONCLUSION: The time to a reliable reading obtained simultaneously in neonatal critical situations differs by the type of the pulse oximeter used, being significantly faster with Masimo Signal Extraction Technology. This may permit for better adjustments of inspired oxygen, aiding in the prevention of damage caused by unnecessary exposure to high or low oxygen.
Assuntos
Hiperóxia/prevenção & controle , Terapia Intensiva Neonatal , Oximetria/instrumentação , Oxigênio/sangue , Ressuscitação , Desenho de Equipamento , Humanos , Hiperóxia/etiologia , Recém-Nascido , Consumo de Oxigênio , Estudos Prospectivos , Reprodutibilidade dos Testes , Ressuscitação/efeitos adversos , Fatores de TempoRESUMO
AIM: To identify whether pulse oximetry technology is associated with decreased retinopathy of prematurity (ROP) and laser treatment. METHODS: Inborn infants <1250 g who had eye exams were compared at two centres in three periods. In Period 1, SpO2 target was ≥93% and pulse oximetry technology was the same in both Centres. In Period 2, guidelines for SpO2 88-93% were implemented at both centres and Centre B changed to oximeters with signal extraction technology (SET(®)) while Centre A did not, but did so in Period 3. One ophthalmology department performed eye exams using international criteria. RESULTS: In 571 newborns <1250 g, birth weight and gestational age were similar in the different periods and centres. At Centre A, severe ROP and need for laser remained the same in Periods 1 and 2, decreasing in Period 3-6% and 3%, respectively. At Centre B, severe ROP decreased from 12% (Period 1) to 5% (Period 2) and need for laser decreased from 5% to 3%, remaining low in Period 3. CONCLUSION: In a large group of inborn infants <1250 g, a change in clinical practice in combination with pulse oximetry with Masimo SET, but not without it, led to significant reduction in severe ROP and need for laser therapy. Pulse oximetry selection is important in managing critically ill infants.
Assuntos
Oximetria , Retinopatia da Prematuridade/prevenção & controle , Feminino , Humanos , Recém-Nascido , Masculino , Oxigênio/análise , Estudos Prospectivos , Retinopatia da Prematuridade/diagnóstico , Índice de Gravidade de DoençaRESUMO
OBJECTIVE: Our aim was to define the relationship of PaO(2) and pulse oxygen saturation values during routine clinical practice and to evaluate whether pulse oxygen saturation values between 85% and 93% were associated with PaO(2) levels of <40 mmHg. METHODS: Prospective comparison of PaO(2) and pulse oxygen saturation values in 7 NICUs at sea level in 2 countries was performed. The PaO(2) measurements were obtained from indwelling arterial catheters; simultaneous pulse oxygen saturation values were recorded if the pulse oxygen saturation values changed <1% before, during, and after the arterial gas sample was obtained. RESULTS: We evaluated 976 paired PaO(2)/pulse oxygen saturation values in 122 neonates. Of the 976 samples, 176 (18%) from infants breathing room air had a mean pulse oxygen saturation of 93.9 +/- 4.3% and a median of 95.5%. The analysis of 800 samples from infants breathing supplemental oxygen revealed that, when pulse oxygen saturation values were 85% to 93%, the mean PaO(2) was 56 +/- 14.7 mmHg and the median 54 mmHg. At this pulse oxygen saturation level, 86.8% of the samples had PaO(2) values of 40 to 80 mmHg, 8.6% had values of <40 mmHg, and 4.6% had values of >80 mmHg. When the pulse oxygen saturation values were >93%, the mean PaO(2) was 107.3 +/- 59.3 mmHg and the median 91 mmHg. At this pulse oxygen saturation level, 39.5% of the samples had PaO(2) values of 40 to 80 mmHg and 59.5% had values of >80 mmHg. CONCLUSIONS: High PaO(2) occurs very rarely in neonates breathing supplemental oxygen when their pulse oxygen saturation values are 85% to 93%. This pulse oxygen saturation range also is infrequently associated with low PaO(2) values. Pulse oxygen saturation values of >93% are frequently associated with PaO(2) values of >80 mmHg, which may be of risk for some newborns receiving supplemental oxygen.
Assuntos
Recém-Nascido/sangue , Unidades de Terapia Intensiva Neonatal , Oximetria , Oxigenoterapia , Humanos , Oxigênio , Oxiemoglobinas/análiseRESUMO
BACKGROUND: Outcomes in patients with ST-elevation myocardial infarction (STEMI) differ between those in clinical trials and those in routine practice, as well as across different regions. We hypothesized that adjustment for baseline risk would minimize such variations. METHODS: The Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction (ExTRACT-TIMI) 25 registry was an observational study of patients with STEMI presenting to hospitals participating in the ExTRACT-TIMI 25 randomized clinical trial. Consecutive patients with STEMI who were not enrolled in the trial were entered into the registry. Demographics, in-hospital therapies, and in-hospital events were collected. Baseline risk was assessed using the TIMI Risk Index for STEMI. To adjust for differences among the countries from which the patients presented, the gross national income per annum per capita (GNI) was used. RESULTS: A total of 3726 patients were registered from 109 sites in 25 countries. Patients in the registry had a higher baseline risk than those in the trial; they had more extensive prior cardiac histories and more comorbidities. Unadjusted in-hospital mortality was higher in the registry (8.3%) than in the trial (6.6%) (hazard ratio, 1.30; P < .001); however, after adjusting for TIMI Risk Index, mortality was similar (hazard ratio(adj), 1.00; P = .97). The GNI was not significantly predictive of in-hospital mortality in the multivariable model of the registry. CONCLUSION: Patients in the registry had higher mortality than those in the trial. This difference could be explained by the higher baseline risk of patients in the registry. After adjusting for baseline risk, the GNI of the country in which the patient presented did not contribute to predicting in-hospital mortality.
Assuntos
Enoxaparina/uso terapêutico , Fibrinolíticos/uso terapêutico , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Reperfusão Miocárdica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Ensaios Clínicos Controlados Aleatórios como Assunto , Sistema de Registros , Medição de Risco , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Heart failure is one of the most important causes of death worldwide. Heart transplant is the last effective alternative when the medical and surgical treatments have failed in patients with end stage heart failure, giving them an 80% one year survival rate. Unfortunately, during the outcome, the heart transplant patients can develop complications such as graft rejection and opportunistic infections because of the use of immunosuppressive therapy. In the present article we report the experience with 33 heart transplant patients. Our program not only has successfully transplanted patients with advanced age but, for the first time in Latin America we have transplanted patients assisted with the ambulatory Thoratec TLC II system. Even with limited resources, we have managed the same complications than other heart transplant programs, our 82% one year survival rate is similar than reports in medical literature.