Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Int J Neurosci ; 133(2): 194-200, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33736564

RESUMO

Purpose:Tau hyperphosphorylation is a modification frequently observed after brain ischemia which has been related to the aggregation of this protein, with subsequent cytoskeletal damage, and cellular toxicity. The present study tests the hypothesis of using glucosamine, an agent that increases protein O-GlcNAcylation, to decrease the levels of phosphorylation in Tau during ischemia-reperfusion.Material and methods: Transient focal ischemia was artificially induced in male Wistar rats by occlusion of the middle cerebral artery (MCAO) with an intraluminal monofilament. A single dose of intraperitoneal glucosamine of 200 mg/kg diluted in normal saline (SSN) was administered 60 min before ischemia. Histological brain sections were processed using indirect immunofluorescence with primary antibodies (anti-O-GlcNAc and anti pTau-ser 396). The Image J software was used to calculate the immunofluorescence signal intensity.Results: The phosphorylation of Tau at the serine residue 396 had a significant decrease with the administration of glucosamine during ischemia-reperfusion compared with the administration of placebo.Conclusions: These results show that glucosamine can reduce the phosphorylation levels of Tau in rodents subjected to ischemia and cerebral reperfusion, which implies a neuroprotective role of glucosamine.


Assuntos
Isquemia Encefálica , Fármacos Neuroprotetores , Traumatismo por Reperfusão , Ratos , Animais , Masculino , Glucosamina/farmacologia , Proteínas tau/metabolismo , Fosforilação , Ratos Wistar , Isquemia Encefálica/tratamento farmacológico , Isquemia , Reperfusão , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Fármacos Neuroprotetores/farmacologia
2.
Rev Chil Pediatr ; 88(3): 354-359, 2017 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-28737194

RESUMO

Noninvasive ventilation (NIV) frequently involves the development of facial pressure ulcers (FPU). Its prevention considers the empirical use of protective patches between skin and mask, in order to reduce the pressure exerted by it. OBJECTIVES: To evaluate the effect of protective patches on the pressure exerted by the facial mask, and its impact on the programmed ventilatory parameters. METHOD: Bilevel NIV simulated model using full face mask in phantom with a physiological airway (ALS PRO +) in supine position. Forehead, chin and cheekbones pressure were measured using 3 types of standard protective patches versus a control group using pressure sensors (Interlinks Electronics®). The values obtained with the protective patches-mask model were evaluated in the programmed variables maximum inspiratory flow (MIF)), expired tidal volume (Vte) and positive inspiratory pressure (IPAP), with Trilogy 100 ventilator, Respironics®. The programming and recording of the variables was carried out in 8 opportunities in each group by independent operators. RESULTS: There was no decrease in facial pressure with any of the protective patches compared to the control group. Moltopren increased facial pressure at all support points (p < 0.001), increased leakage, it decreased MIF, Vte and IPAP (p < 0.001). Hydrocolloid patches increased facial pressure only in the left cheekbone, increased leakage and decreased MIF. Polyurethane patches did not produce changes in facial pressure or ventilatory variables. CONCLUSION: The use of protective patches of moltopren, hydrocolloid and polyurethane transparent did not contribute to the decrease of the facial pressure. A deleterious effect of the moltopren and hydrocolloid patches was observed on the administration of ventilatory variables, concluding that the non-use of the protective patches allowed a better administration of the programmed parameters.


Assuntos
Bandagens , Pressão Positiva Contínua nas Vias Aéreas/instrumentação , Máscaras/efeitos adversos , Ventilação não Invasiva/instrumentação , Úlcera por Pressão/prevenção & controle , Pressão/efeitos adversos , Face , Humanos , Manequins , Úlcera por Pressão/etiologia
3.
Opt Express ; 23(7): 8555-64, 2015 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-25968693

RESUMO

Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5λ transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system.

4.
Opt Lett ; 40(2): 245-8, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25679855

RESUMO

In the past, it has been demonstrated that it is possible to produce terajets with high resolution at its focus using 3D dielectric cuboids under plane-wave illumination. Here, a systematic study of the harmonic and angular response of terajets using cuboids is performed. Mutifrequency focusing is demonstrated at the fundamental frequency and two higher frequency harmonics showing an intensity enhancement of ∼10, ∼18, and ∼14 for each case. This capability to use 3D dielectric cuboids to produce terajets at the fundamental frequency and first harmonic is experimentally evaluated at sub-THz frequencies, with good agreement with numerical results. Moreover, a robust angular response is demonstrated numerically and experimentally showing that the intensity at the focal position is maintained in a wide angular range (from 0° to 45°), demonstrating the capability to work as a wide scanning terajet-focusing lens. The results here presented may be scaled at different frequency bands such as optical frequencies and may be used in microscopy techniques and sensors.

5.
Opt Lett ; 40(10): 2329-32, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26393731

RESUMO

A photonic jet (a terajet at terahertz frequencies) commonly denotes a specific, spatially localized region in the near field on the front side of a dielectric particle with a diameter comparable with the wavelength illuminated by a plane wave on its back side (i.e., the jet emerges from the shadow surface of a dielectric particle). In this Letter, the formation of a photonic jet is demonstrated using the recently proposed three-dimensional (3D) dielectric cuboids working in the "reflection" mode when the specific, spatially localized region is localized in the direction of the incident wavefront. The results of the simulations based on the Finite Integration Technique are discussed. All dimensions are given in wavelength units so that all results can be scaled to any frequency of interest, including optical frequencies, thus simplifying the fabrication process compared with spherical dielectrics. The results presented here may be of interest for novel applications, including microscopy techniques and sensors.

6.
Biochem Biophys Res Commun ; 451(4): 609-14, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-25128831

RESUMO

In this work we characterized the infection of a primary culture of rat osteoblastic lineage cells (OBCs) with measles virus (MeV) and the effect of infection on cell differentiation and maturation. Infection of OBCs with MeV led to high titers of infectivity released early after infection. Also, analysis of mRNAs corresponding to osteogenic differentiation markers like alkaline phosphatase (ALP), bone sialo-protein (BSP) and bone morphogenetic proteins (BMPs) 1-4-5-7 in OBCs revealed higher values (2-75-fold of increment) for infected cells in comparison with uninfected controls. Differentiation of OBCs in osteogenic medium prior to infection influenced the level of stimulation induced by MeV. Furthermore, treatment of OBCs with Ly294002, a PI3K/AKT inhibitor, increased viral titers, whereas treatment with 10µM or 100µM ATPγS diminished MeV multiplication. In addition, increments of osteogenic differentiation markers induced by MeV infection were not modified either by treatment with Ly294002 or ATPγS. These data provide the first evidence demonstrating that MeV can infect osteoblasts in vitro leading to osteoblastic differentiation, a key feature in bone pathogenic processes like otosclerosis.


Assuntos
Vírus do Sarampo/fisiologia , Osteoblastos/virologia , Osteogênese/fisiologia , Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/farmacologia , Fosfatase Alcalina/biossíntese , Animais , Proteína Morfogenética Óssea 4/biossíntese , Osso e Ossos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Cromonas/farmacologia , Morfolinas/farmacologia , Osteoblastos/fisiologia , Otosclerose/etiologia , Inibidores de Fosfoinositídeo-3 Quinase , Ratos , Replicação Viral
7.
Rev Neurol ; 77(7): 159-165, 2023 10 01.
Artigo em Espanhol | MEDLINE | ID: mdl-37750546

RESUMO

INTRODUCTION: Lack of habituation is the most reproducible interictal neurophysiological phenomenon in episodic migraine. The aim of this study is to evaluate the habituation phenomenon by examining the nociceptive blink reflex in patients with episodic migraine. SUBJECTS AND METHODS: We conducted a cross-sectional observational case-control study. Patients with episodic migraine were selected consecutively and studied during the interictal phase. The nociceptive blink reflex was examined and a study was conducted comparing symmetry, analysis of the Euclidean distances and assessment of latency prolongation between stimulation blocks. RESULTS: Thirty-one patients and 16 healthy controls were included, their mean ages being 32.25 and 32.35 years, respectively. The controls displayed left-right symmetry. The Euclidean and Manhattan distances showed that the means of the block latencies of the groups are different and increase according to the number of blocks being compared. The means of the block latencies do not differ significantly in the migraine patient group, in contrast to what is seen in the healthy group. CONCLUSION: Habituation deficit was observed in the interictal phase in patients with episodic migraine compared to controls, as measured by the absence of latency prolongation in the nociceptive blink reflex.


TITLE: Estudio del déficit de habituación en pacientes con migraña episódica mediante reflejo de parpadeo nociceptivo.Introducción. La falta de habituación es el fenómeno neurofisiológico interictal más reproducible en la migraña episódica. El objetivo de este estudio es evaluar el fenómeno de habituación mediante el estudio del reflejo de parpadeo nociceptivo en pacientes con migraña episódica. Sujetos y métodos. Estudio observacional transversal de casos y controles. Los pacientes con migraña episódica fueron seleccionados de manera consecutiva, estudiados durante la fase interictal. Se estudió el reflejo de parpadeo nociceptivo, y se realizó un estudio comparativo de simetría, análisis de distancias euclidianas y valoración de prolongación de latencias entre bloques de estimulación. Resultados. Se incluyó a 31 pacientes y 16 controles sanos, con una edad media de 32,25 y 32,35 años, respectivamente. Los controles mostraron simetría izquierda-derecha. Las distancias euclidiana y Manhattan demostraron que las medias de las latencias por bloque de los grupos son diferentes y se incrementan según el número de bloques que se comparen. Las medias de las latencias de los bloques no difieren significativamente en el grupo de pacientes con migraña, a diferencia del grupo de sanos. Conclusión. Se observó un déficit de habituación en la fase intercrítica en pacientes con migraña episódica frente a controles, medido por la ausencia de prolongación de latencias en el reflejo de parpadeo nociceptivo.


Assuntos
Piscadela , Transtornos de Enxaqueca , Adulto , Humanos , Estudos de Casos e Controles , Estudos Transversais , Habituação Psicofisiológica , Nociceptividade
8.
Chem Biodivers ; 9(8): 1599-610, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22899620

RESUMO

The aim of this study was to quantify mucilages, pectins, hemicelluloses, and cellulose of nopalitos (edible, as vegetable, young cladodes of flat-stemmed spiny cacti) of most consumed Mexican cultivars, and sweet and acid cactus pear fruits of Opuntia spp. The hypothesis is that, regardless of their unavailable polysaccharides diversity, nopalitos and cactus pear fruits are rich sources of soluble and insoluble dietary fiber. Twelve cultivars of Opuntia spp. were used. Nopalitos had a significant variation in structural polysaccharides among the cultivars: mucilages (from 3.8 to 8.6% dry matter (DM)) averaged near a half of pectins content (from 6.1 to 14.2% DM) and tightly bound hemicelluloses (from 2.2 to 4.7% DM), which were the less abundant polysaccharides, amounted 50% of the loosely bound hemicelluloses (from 4.3 to 10.7% DM). Acid fruits (or 'xoconostle') had significantly higher unavailable polysaccharides content than sweet fruit, and contain similar proportions than nopalitos. Unavailable polysaccharides represent a high proportion of dry tissues of nopalitos and cactus pear fruits, composition of both of these soluble and insoluble polysaccharides (total dietary fiber) widely vary among cultivars without an evident pattern. Nopalitos and cactus pear fruit can be considered an excellent source of dietary fiber.


Assuntos
Fibras na Dieta/análise , Frutas/química , Opuntia/química , Polissacarídeos/análise , Celulose/análise , Pectinas/análise , Mucilagem Vegetal/análise
9.
Semergen ; 48(1): 3-13, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-34454826

RESUMO

OBJECTIVES: To assess diagnosis and therapeutic decisions-making by General Practitioners (GP) using ApnealinkTM® (AL) in patients with high suspicion of obstructive sleep apnea (OSA), in comparison with conclusions of Hospital Sleep Unit (HSU) specialists based on home respiratory polygraphy (PGR) results. METHODS: This study involved patients previously selected by HSU for sleep testing by PGR. After it, patients were offered to complete AL test. PGR was checked at HSU; AL was checked by hemoglobin desaturation index of 4% (4% ODI), (4% AL) and 3% (3% ODI) patients with positive test to proceed with CPAP; and those with negative test for further testing. Automatically adjusted 4% AL, was considered valid as it was demonstrated to be equivalent to manual AL. Results were compared by automatically adjusted 3%AL against PGR results. RESULTS: 48 patients were collected. 43 had AL valid test, 45 had PGR valid study, and 41 had both valid test. 27 patients (62,8%) had positive 4% AL (OR 5,51, p < 0,05), that showed AHI ≥ 15/h at 3% AL test; and 19 patients (42,2%) had a positive PGR test. 31 (72%) patients had a positive 3% AL. AL had shown to be a good screening method of SAHS. CONCLUSIONS: There is equivalence between the decisions of GP and HSU. AL is a good diagnostic tool and screening method for OSA in primary care when it is used in patients with high suspicion of moderate-severe OSA.


Assuntos
Clínicos Gerais , Síndromes da Apneia do Sono , Apneia Obstrutiva do Sono , Humanos , Oximetria , Polissonografia , Atenção Primária à Saúde , Síndromes da Apneia do Sono/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/terapia
10.
Eur Respir J ; 36(4): 758-65, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19996189

RESUMO

We aimed to describe changes in the prevalence of chronic obstructive pulmonary disease (COPD) in Spain by means of a repeated cross-sectional design comparing two population-based studies conducted 10 yrs apart. We compared participants from IBERPOC (Estudio epidemiológico de EPOC en España) (n = 4,030), conducted in 1997, with those of EPI-SCAN (Epidemiologic Study of COPD in Spain) (n = 3,802), conducted in 2007. Poorly reversible airflow obstruction compatible with COPD was defined according to the old European Respiratory Society definitions. COPD prevalence in the population between 40 to 69 yrs of age dropped from 9.1% (95% CI 8.1-10.2%) in 1997 to 4.5% (95% CI 2.4-6.6%), a 50.4% decline. The distribution of COPD prevalence by severity also changed from 38.3% mild, 39.7% moderate and 22.0% severe in 1997, to 85.6% mild, 13.0% moderate and 1.4% severe in 2007, and in the 40-69 yr EPI-SCAN sub-sample to 84.3% mild, 15.0% moderate and 0.7% severe. Overall, underdiagnosis was reduced from 78% to 73% (not a significant difference) and undertreatment from 81% to 54% (p<0.05) within this 10-yr frame. The finding of a substantial reduction in the prevalence of COPD in Spain is unexpected, as were the observed changes in the severity distribution, and highlights the difficulties in comparisons between repeated cross-sectional surveys of spirometry in the population.


Assuntos
Doença Pulmonar Obstrutiva Crônica/epidemiologia , Adulto , Fatores Etários , Idoso , Estudos Transversais , Estudos Epidemiológicos , Feminino , Geografia , Humanos , Pneumopatias/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Fatores Sexuais , Espanha
11.
Clin Endocrinol (Oxf) ; 72(4): 489-95, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19863573

RESUMO

OBJECTIVE: To assess normative data and the usefulness of spontaneous and LHRH analogue-stimulated serum LH and FSH levels measured by immunoradiometric assays (IRMA) in the evaluation of normal puberty. DESIGN: Prospective. Healthy girls in Tanner I and Tanner II from the local community were invited to participate (n = 47). METHODS: A leuprolide acetate test (500 mcg/m(2); sc) was performed. LH and FSH levels were determined using IRMA. Tanner II girls were assessed every 6 months until Tanner V. Girls who progressed from Tanner II to Tanner III in the next 6 months were called Tanner II-2; otherwise, they were called Tanner II-1. RESULTS: The prepubertal upper limit (CI 95%) was 0.49 IU/l for basal LH and 5.1 IU/l for stimulated LH. Taking into account these LH cut-off limits, 72.2% and 66.7% of Tanner II-1 and 41.6% and 41.7% of Tanner II-2 subjects presented overlapping values for basal and stimulated LH, respectively, as compared with the Tanner I group. The cut-offs for basal and stimulated LH to predict progression from Tanner II to Tanner III in the next 6 months were a basal LH level > or =0.49 IU/l (Sensitivity = 0.58; 1-Specificity = 0.33) and a poststimulated LH level > or =4.75 IU/l (Sensitivity = 0.67; 1-Specificity = 0.44). CONCLUSION: According to an IRMA, the basal and leuprolide acetate gonadotrophin response patterns during the beginning stages of puberty overlapped between Tanner I and Tanner II, and the cut-offs of basal and stimulated LH levels to predict progress from Tanner II to Tanner III had low sensitivities for the following 6 months.


Assuntos
Hormônio Foliculoestimulante/sangue , Leuprolida , Hormônio Luteinizante/sangue , Puberdade/fisiologia , Área Sob a Curva , Criança , Pré-Escolar , Feminino , Humanos , Estudos Longitudinais , Sensibilidade e Especificidade
12.
J Environ Radioact ; 99(10): 1520-4, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18243444

RESUMO

In situ gamma spectrometry provides a fast method to determine (137)Cs inventories in soils. To improve the accuracy of the estimates, one can use not only the information on the photopeak count rates but also on the peak to forward-scatter ratios. Before applying this procedure to field measurements, a calibration including several experimental simulations must be carried out in the laboratory. In this paper it is shown that Monte Carlo methods are a valuable tool to minimize the number of experimental measurements needed for the calibration.


Assuntos
Monitoramento de Radiação/instrumentação , Monitoramento de Radiação/métodos , Calibragem , Radioisótopos de Césio/análise , Radioisótopos de Césio/normas , Método de Monte Carlo , Reprodutibilidade dos Testes , Espectrometria gama/métodos
13.
Nanoscale ; 10(28): 13607-13616, 2018 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-29978869

RESUMO

Nanogaps supporting cavity plasmonic modes with unprecedented small mode volume are attractive platforms for tailoring the properties of light-matter interactions at the nanoscale and revealing new physics. Hitherto, there is a concerning lack of analytical solutions to divide the complex interactions into their different underlying mechanisms to gain a better understanding that can foster enhanced designs. Bowtie apertures are viewed as an effective and appealing nanocavity and are studied here within the analytical frame of conformal transformation. We show how the non-radiative Purcell enhancement of a quantum emitter within the bowtie nanocavity depends strongly not only on the geometry of the nanocavity, but also on the position and orientation of the emitter. For a 20 nm diameter (∅ 20 nm) bowtie nanocavity, we report a change of up to two orders of magnitude in the maximum non-radiative Purcell enhancement and a shift in its peak wavelength from green to infra-red. The changes are tracked down to the overlap between the emitter field and the gap plasmon mode field distribution. This analysis also enables us to understand the self-induced trapping potential of a colloidal quantum dot inside the nanocavity. Since transformations can be cascaded, the technique introduced in this work can also be applied to a wide range of nanocavities found in the literature.

14.
J Clin Endocrinol Metab ; 91(9): 3377-81, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16787993

RESUMO

CONTEXT: There are limited and controversial data concerning puberty characteristics in girls born small for gestational age (SGA). OBJECTIVE: The objective of the study was to document clinical, ultrasonographic, and biochemical characteristics at the beginning of puberty in matched healthy girls born either SGA or appropriate for gestational age (AGA) recruited from the community. PATIENTS: Inclusion criteria were breast Tanner stage II and a body mass index between the 10th and 95th percentiles. INTERVENTIONS: Recruited subjects underwent a complete physical exam, bone age, and ultrasound measurements of the internal genitalia. Hormonal assessment included fasting early morning dehydroepiandrosterone sulfate, androstenedione, SHBG, inhibin-B, FSH, LH, estradiol (E2), 17-hydroxyprogesterone (17OH Prog), and testosterone. Thereafter, a GnRH agonist test (leuprolide 500 microg, sc) was performed with FSH and LH at time 3 and 24 h for E2, 17OH Prog, and testosterone. RESULTS: Sixty-five girls (35 AGA, 30 SGA) with a mean age of 9.9 +/- 1.03 (7.8-12.5) yr, similar bone age/chronological age (1.02 +/- 0.8 in AGA and 1 +/- 0.76 in SGA), median height of 1.35 +/- 0.06 cm, and similar waist to hip ratio were included. No differences in the presence of pubic hair, axillary hair, apocrine odor, or ultrasound measurements were found. SGA girls had increased baseline E2 as well as stimulated E2 and 17OH Prog. CONCLUSIONS: In a preliminary sample of lean, healthy girls recruited from the community born either SGA or AGA, we observed slight hormonal differences at the beginning of puberty. Longitudinal follow-up of this cohort will allow us to understand whether these differences are maintained and have a clinical impact in their pubertal development.


Assuntos
Recém-Nascido Pequeno para a Idade Gestacional/crescimento & desenvolvimento , Puberdade/fisiologia , 17-alfa-Hidroxiprogesterona/sangue , Androstenodiona/sangue , Antropometria , Criança , Estudos de Coortes , Sulfato de Desidroepiandrosterona/sangue , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional/sangue , Inibinas/sangue , Hormônio Luteinizante/sangue , Ovário/anatomia & histologia , Ovário/diagnóstico por imagem , Estudos Prospectivos , Puberdade/sangue , Globulina de Ligação a Hormônio Sexual/análise , Testosterona/sangue , Ultrassonografia , Útero/anatomia & histologia , Útero/diagnóstico por imagem
15.
Quintessence Int ; 37(7): 551-6, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16841603

RESUMO

OBJECTIVE: The aim of this study was to evaluate the clinical efficacy of home-administered vital bleaching procedures and possible adverse effects derived from their use. One gel containing 3.5% hydrogen peroxide with a 5% potassium nitrate component (FKD, Kin Lab) was compared with a carbamide peroxide-based gel with a concentration of 10% (Opalescence, Ultradent). METHOD AND MATERIALS: Two sample groups were designed, each composed of 8 patients. All patients employed both bleaching products, 1 in the maxillary arch and the other in the mandibular arch on a random basis. The treatment was applied for 3 hours a day for 4 weeks. The degree of bleaching was evaluated using the Vita guide arranged by brightness. Dental sensitivity was measured with a specially designed 4-point scale. Gingival irritation was registered by the presence or absence of lesions in the marginal gingiva related to treatment. RESULTS: The degree of bleaching was similar with both products (4.8 Vita shade tabs). The hydrogen peroxide product with potassium nitrate provoked less dental sensitivity, although the difference between the 2 products was insignificant (P = .063). Gingival irritation appeared in 6 subjects, but was unrelated to the applied product. CONCLUSION: Under the conditions of this study, no statistically significant differences were detected between 3.5% hydrogen peroxide containing 5% potassium nitrate (FKD) and the 10% carbamide peroxide-based product (Opalescence).


Assuntos
Dispositivos para o Cuidado Bucal Domiciliar , Peróxido de Hidrogênio/uso terapêutico , Oxidantes/uso terapêutico , Peróxidos/uso terapêutico , Clareamento Dental/métodos , Ureia/análogos & derivados , Resinas Acrílicas , Adulto , Peróxido de Carbamida , Sensibilidade da Dentina/induzido quimicamente , Portadores de Fármacos , Combinação de Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Humanos , Peróxido de Hidrogênio/efeitos adversos , Masculino , Nitratos/uso terapêutico , Oxidantes/efeitos adversos , Peróxidos/efeitos adversos , Polivinil , Compostos de Potássio/uso terapêutico , Clareamento Dental/efeitos adversos , Descoloração de Dente/tratamento farmacológico , Ureia/efeitos adversos , Ureia/uso terapêutico
16.
Br Dent J ; 220(1): 11-4, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26768458

RESUMO

The sectional matrix is the best way to achieve a strong contact point in Class II restorations with composite resin in the posterior dental sector. The pre-wedging is essential to get a separation between teeth which avoid the matrix deformation during its insertion. This article describes the clinical technique for restoring Class II cavities using a sectional matrix.


Assuntos
Materiais Dentários/uso terapêutico , Restauração Dentária Permanente/métodos , Cárie Dentária/cirurgia , Preparo da Cavidade Dentária/métodos , Humanos
17.
Sci Rep ; 6: 19642, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26791421

RESUMO

Coralline red algae are significant components of sea bottom and up to now considered as exclusively marine species. Here we present the first coralline alga from a freshwater environment, found in the Cetina River (Adriatic Sea watershed). The alga is fully adapted to freshwater, as attested by reproductive structures, sporelings, and an inability to survive brackish conditions. Morphological and molecular phylogenetic analyses reveal the species belongs to Pneophyllum and is described as P. cetinaensis sp. nov. The marine-freshwater transition most probably occurred during the last glaciation. The brackish-water ancestor was preadapted to osmotic stress and rapid changes in water salinity and temperature. The particular characteristics of the karst Cetina River, such as hard water enriched with dissolved calcium carbonate and a pH similar to the marine environment, favoured colonization of the river by a marine species. The upstream advance and dispersal is facilitated by exceptionally pronounced zoochory by freshwater gastropods. Pneophyllum cetinaensis defies the paradigm of Corallinales as an exclusively marine group.


Assuntos
Ecossistema , Água Doce , Rodófitas , Genes Bacterianos , Filogenia , Rodófitas/classificação , Rodófitas/genética , Rodófitas/ultraestrutura , Esporos Bacterianos
18.
Biochim Biophys Acta ; 438(1): 324-31, 1976 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-938684

RESUMO

A study was undertaken to ascertain whether dihydrofolic acid is produced in the complex formed with 5,10-methylenetetrahydrofolate, 5-fluorodeoxyuridylate and thymidylate synthetase, as suggested by ultraviolet difference spectral studies. The complex was formed using the cofactor specifically labeled with tritium at the 6-position. After dissociation by equilibration with unlabeled cofactor, it was demonstrated that the tritium remained exclusively at the 6-position. Had oxidation of the cofactor occurred within the complex to give a methylated enzyme form, tritium should have been transferred to the one-carbon unit of the cofactor. It was also found that the difference spectrum of the ternary complex which resembles that of dihydrofolic acid can also be produced by substituting an analog of the cofactor which is not susceptible to oxidation. The results described here demonstrate that oxidation of the cofactor does not occur in the ternary complex and suggest that the unusual ultraviolet spectrum results from perturbations of a chromophore of the bound cofactor.


Assuntos
Fluordesoxiuridilato/metabolismo , Metiltransferases/metabolismo , Tetra-Hidrofolatos/metabolismo , Timidilato Sintase/metabolismo , Nucleotídeos de Uracila/metabolismo , Modelos Químicos , Ligação Proteica , Espectrofotometria Ultravioleta
19.
DNA Cell Biol ; 24(9): 595-604, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16153160

RESUMO

Sufficient levels of gene expression are required for effective gene therapy. One of the major obstacles in gene therapy is the low transgene expression obtained from currently available vector systems. To address this issue, we employed a transcriptional amplifier strategy in a single construct to enhance transgene expression. In the amplifier vectors (pHi-1 and pHi-2), the strong CMV promoter was used to drive a transcriptional factor, Tat, which could transactivate a second promoter (HIV1 LTR or HIV2 LTR) located in the same construct driving the gene of interest. Using the human interleukin-2 (IL-2) cytokine gene, our data showed that the pHi-1/2 amplifier vectors could produce significantly higher IL-2 levels in human lung cancer cells (A549) and breast cancer cells (MCF-7) than that obtained by directly using the CMV promoter alone. Injection of pHi-2-IL-2-modified Lewis Lung (LL/2) tumor clones led to significantly slower tumor growth and longer survival in mice compared to those injected with either CMV promoter driven IL-2 clones or the parental tumor cells. Our results demonstrated that the transcriptional amplifier-based expression cassettes could be very useful in applications where high levels of gene expression are difficult to achieve.


Assuntos
Regulação Neoplásica da Expressão Gênica , Terapia Genética/métodos , Vetores Genéticos/genética , Interleucina-2/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/terapia , Animais , Linhagem Celular Tumoral , Citomegalovirus , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Proteínas de Fluorescência Verde , Repetição Terminal Longa de HIV/genética , Humanos , Interleucina-2/genética , Neoplasias Pulmonares/genética , Camundongos , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transgenes/genética
20.
Oper Dent ; 40(5): 458-61, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26151458

RESUMO

This article describes the use of a copper band as a matrix to build up resin cores in endodontically treated teeth that have a partially subgingival margin. The copper band is adjusted to the contour of the remaining dental structure and extends beyond the margins to ensure complete isolation in order to provide a matrix to fabricate a core.


Assuntos
Resinas Compostas , Cobre , Fraturas dos Dentes , Dente não Vital , Planejamento de Prótese Dentária , Humanos , Técnica para Retentor Intrarradicular , Raiz Dentária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA