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1.
Eye (Lond) ; 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38347178

RESUMO

Economic evaluations are tools for assessing emerging technologies and a complement for decision-making in healthcare systems. However, this topic may not be familiar for doctors and academics, who may be confused when interpreting the results of studies using these tools. Cataract is a disease which has received special attention in healthcare systems due to its high incidence, the great impact that it could have on patients' quality of life, and the fact that it can be definitively solved in almost all cases through cataract surgery. Historically, economic evaluations in cataract surgery have been conducted for many purposes by simply assessing whether the surgery is cost-effective for specific questions related to the implantation of multifocal intraocular lenses, surgical techniques, optimizing assessments, preventing diseases or complications, etc. Moreover, although there are systematic reviews about cataract surgery and narrative reviews introducing the concept of economic evaluations, as far as we know, no previous study has been conducted that synthesizes and integrates evidence coming from both fields. Thus, the purpose of this narrative review is to introduce doctors and academics to economic evaluation tools, to describe how these have been historically applied to cataract surgery, and to provide special considerations for the correct interpretation of economic studies.

4.
J Fr Ophtalmol ; 46(10): 1204-1211, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37658033

RESUMO

OBJECTIVE: To analyze the long-term results of treatment of active age-related macular degeneration (AMD) with anti-vascular endothelial growth factor (VEGF) agents using the treat-extend-stop (TES) approach, defining predictive factors for stoppage of the treatment and recurrences in a real-world setting. METHODS: Data from 191 eyes treated with intravitreal injections for choroidal neovascularization due to AMD were retrospectively reviewed. Changes in best-corrected visual acuity (BCVA) and membrane activity (optical coherence tomography) were recorded and evaluated over a 48-month follow-up. Logistic regression analysis was used to determine predictors of treatment stoppage and recurrences after stoppage. RESULTS: BCVA improvement was found in 70.5% of eyes at 48 months, and remaining signs of activity in 27.9%. Disease inactivity was achieved in 69 eyes (31.9%), with a relapse of the membrane in 29 of these eyes (42.0%). Significant independent predictors of treatment stoppage were found: no foveal membrane, inactive membrane at 12, 24, 36 and 48 months, extension interval>8 weeks at 12 and 24 months,>15 injections at 24 months, and baseline BCVA>61 letters. Concerning recurrent membranes, only the presence of membrane activity at 36 months and baseline BCVA>61 letters were independent predictors. CONCLUSIONS: Anti-VEGF treatment of AMD using the TES protocol allows for successful visual restoration in most patients, with more likely disease inactivity in those eyes with better baseline BCVA, maintaining signs of membrane inactivity during the first two years of follow-up and requiring fewer injections.


Assuntos
Neovascularização de Coroide , Degeneração Macular , Humanos , Inibidores da Angiogênese , Seguimentos , Resultado do Tratamento , Estudos Retrospectivos , Neovascularização de Coroide/diagnóstico , Neovascularização de Coroide/tratamento farmacológico , Degeneração Macular/diagnóstico , Injeções Intravítreas , Fundo de Olho , Tomografia de Coerência Óptica
5.
J Fr Ophtalmol ; 46(5): 501-509, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36775734

RESUMO

OBJECTIVE: To determine the advantages and complication rate of capsulotomy performed with femtosecond laser in white complex cataract cases. STUDY DESIGN: Retrospective case series. PARTICIPANTS: Sixteen eyes of 16 patients. METHODS: This was a single-center retrospective review of white cataract surgery cases in which the femtosecond laser (LenSx, Alcon Laboratories, Fortworth, Texas, USA) was used between May 2019 and February 2021. Outcome measures included an assessment of the capsulotomy, identification of tags, surgical time, cumulative dispersed energy (CDE) and postoperative management. RESULTS: Sixteen eyes of 16 patients were included in this study; capsule tags occurred in six patients (37.5%). In 2 patients, the capsule presented small adhesions that were identified and removed. One patient presented a very significant contraction of the anterior capsule with an incomplete cut zone of 2 to 4hours. In a patient with nystagmus, the capsulotomy was performed without complications under peribulbar anesthesia. CONCLUSIONS: The femtosecond laser permitted capsulotomies of better shape, size and regularity in complex cases of white cataract and in combination with conditions such as nystagmus and prior corneal transplantation. The microadhesions and untreated areas were identified with trypan blue, which is essential to use in these cases to avoid associated complications.


Assuntos
Extração de Catarata , Catarata , Terapia a Laser , Facoemulsificação , Humanos , Estudos Retrospectivos , Terapia a Laser/efeitos adversos , Extração de Catarata/efeitos adversos , Catarata/complicações , Lasers
6.
BMC Ophthalmol ; 22(1): 253, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35672688

RESUMO

BACKGROUND: Interest in developing alternative methods for the treatment of amblyopia has long been a topic of interest among clinicians and researchers, as prescribed occlusion and penalization therapies do not always provide an effective response and are associated with a high risk of recurrence and non-compliance. Here, we present the protocol of a small-scale RCT to evaluate the safety and clinical efficacy of a novel VR-based system designed to provide binocular vision training to children with anisometropic amblyopia. METHODS: We aim to recruit a total of 60 children with anisometropic amblyopia aged 5-17 years with no previous treatment for amblyopia other than refractive correction from the pediatric ophthalmology units of the University Clinical Hospital of Valladolid and the Vithas Medimar International Hospital of Alicante. Children who meet the eligibility criteria and consent to participate will be randomly assigned to a three-month intervention group of 18 half-hour in-office therapy sessions with the NEIVATECH system (group A) or to a parallel group receiving 2 hours of conventional patching per day at home for the same period of time (group B). Assessments of visual function will be carried out before the intervention and at 1, 2 and 3 months, with changes in distance BCVA being the primary outcome measure to be considered. Patient safety, compliance, satisfaction and acceptance to treatment will also be assessed after therapy as other valuable outcome measures. In addition, a rsfMRI scan will be performed on a subgroup of 5 patients from each group at the pre-intervention visit and at the post-intervention visit to test the effects of both therapies on neural plasticity in the visual cortex. DISCUSSION: The NEIVATECH system has been conceived as a serious game designed to provide binocular vision training to anisometropic amblyopic children by complementing the concepts of perceptual learning, dichoptic training and gamification in an immersive VR environment. We hope that this novel approach may lead to greater improvements in vision performance than those provided so far by conventional patching in anisometropic amblyopic children. TRIAL REGISTRATION: This protocol was registered with ClinicalTrials.gov ( NCT04819386 ) on 29 March 2021.


Assuntos
Ambliopia , Jogos de Vídeo , Realidade Virtual , Ambliopia/terapia , Criança , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Privação Sensorial , Resultado do Tratamento , Visão Binocular/fisiologia , Acuidade Visual
7.
Actas dermo-sifiliogr. (Ed. impr.) ; 112(7): 654-660, jul.-ago. 2021. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-213442

RESUMO

La aparición de úlceras perianales en relación con una pomada antihemorroidal es una condición nunca antes reportada en la literatura. Presentamos una serie de 11 casos de 10 hospitales españoles con diagnóstico de úlceras perianales tras la aplicación de una misma pomada antihemorroidal con acetónido de triamcinolona, lidocaína y pentosano polisulfato sódico como principios activos. No se ha podido identificar ninguna condición previa o enfermedad concomitante que pudiera justificar un diagnóstico etiológico alternativo y tras retirar la pomada antihemorroidal se ha evidenciado una resolución completa de las úlceras en un periodo medio de 8 semanas. Esta serie de casos evidencia el potencial efecto dañino de un producto farmacéutico no sujeto a prescripción ni seguimiento médico y la necesidad de interrogar por el uso de agentes tópicos ante la aparición de úlceras perianales (AU)


The development of perianal ulcers related to the use of a hemorrhoidal ointment has not been reported in the literature. We describe a series of 11 patients who were treated for perianal ulcers in 10 Spanish hospitals after they used the same ointment containing the active ingredients triamcinolone acetonide, lidocaine, and pentosan polysulfate sodium. No prior or concomitant conditions suggesting an alternative cause for the condition could be identified, and after the patients stopped using the ointment, their ulcers cleared completely in 8 weeks on average. This case series shows the damage that can be caused by an over-the-counter pharmaceutical product used without medical follow-up. It also illustrates the need to ask patients with perianal ulcers about any topical agents used before the lesions appeared (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Fissura Anal/induzido quimicamente , Hemorroidas/tratamento farmacológico , Pomadas/efeitos adversos , Triancinolona Acetonida/efeitos adversos , Lidocaína/efeitos adversos , Poliéster Sulfúrico de Pentosana/efeitos adversos
8.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33636161

RESUMO

The development of perianal ulcers related to the use of a hemorrhoidal ointment has not been reported in the literature. We describe a series of 11 patients who were treated for perianal ulcers in 10 Spanish hospitals after they used the same ointment containing the active ingredients triamcinolone acetonide, lidocaine, and pentosan polysulfate sodium. No prior or concomitant conditions suggesting an alternative cause for the condition could be identified, and after the patients stopped using the ointment, their ulcers cleared completely in 8 weeks on average. This case series shows the damage that can be caused by an over-the-counter pharmaceutical product used without medical follow-up. It also illustrates the need to ask patients with perianal ulcers about any topical agents used before the lesions appeared.

9.
Sci Rep ; 11(1): 882, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441607

RESUMO

Tropane alkaloids and terpenoids are widely used in the medicine and pharmaceutic industry and evolved as chemical defenses against herbivores and pathogens in the annual herb Datura stramonium (Solanaceae). Here, we present the first draft genomes of two plants from contrasting environments of D. stramonium. Using these de novo assemblies, along with other previously published genomes from 11 Solanaceae species, we carried out comparative genomic analyses to provide insights on the genome evolution of D. stramonium within the Solanaceae family, and to elucidate adaptive genomic signatures to biotic and abiotic stresses in this plant. We also studied, in detail, the evolution of four genes of D. stramonium-Putrescine N-methyltransferase, Tropinone reductase I, Tropinone reductase II and Hyoscyamine-6S-dioxygenase-involved in the tropane alkaloid biosynthesis. Our analyses revealed that the genomes of D. stramonium show signatures of expansion, physicochemical divergence and/or positive selection on proteins related to the production of tropane alkaloids, terpenoids, and glycoalkaloids as well as on R defensive genes and other important proteins related with biotic and abiotic pressures such as defense against natural enemies and drought.


Assuntos
Datura stramonium/genética , Datura stramonium/metabolismo , Defesa das Plantas contra Herbivoria/genética , Oxirredutases do Álcool/metabolismo , Alcaloides/metabolismo , Evolução Biológica , Meio Ambiente , Evolução Molecular , Interação Gene-Ambiente , Genômica/métodos , Solanaceae/genética , Solanaceae/metabolismo , Tropanos/metabolismo , Sequenciamento Completo do Genoma
10.
Polymers (Basel) ; 12(11)2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33114527

RESUMO

The development of high-complexity geometry parts is one of the main goals of additive manufacturing technology. However, the failure of printed structures and the joining of different parts to create complex assemblies represents a real challenge in the research of efficient and sustainability techniques for the permanent assembly of polymers. Laser welding processes have been used as a single-step method to join metals for years. Nowadays, the growing trend in the use of thermoplastics for additive manufacturing has led to the need to adapt this technique to materials with a very specific nature and which are more sensitive to thermal effects. In addition, the possibility of transmitting the laser beam through transparent polymer layers allows to us focus the energy supply on internal sections of the assembled components. In this research, an infrared laser marking system was used to join two different samples of polylactic acid manufactured by fused deposited modeling technology. In order to increase the effectiveness of the bonding process, a transparent and a dark sample have been used as assembly material, focusing the laser beam on the interface area of the two parts. By means of tensile tests, dimensional measurement and the use of optical microscopy techniques, a basis was established that links the supplied energy by laser to the joining performance.

11.
J Ophthalmol ; 2020: 8858317, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33552596

RESUMO

PURPOSE: To compare the effect of different types of intraocular tamponade and different types of postoperative positioning on the closure of idiopathic macular hole (IMH). METHODS: Prospective randomized clinical trial enrolling 104 eyes of 100 patients (age, 57-87 years) undergoing MH surgery. All patients were operated on by an experienced surgeon using 25-gauge pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling. Patients were randomized according to the type of intraocular tamponade and postoperative positioning into the following four groups: SF6 + nonsupine reading position (n = 26) (group 1), air + nonsupine reading position (n = 25) (group 2), air + prone position (n = 26) (group 3), or SF6 + prone position (n = 27) (group 4). The follow-up period was 6 months. RESULTS: MH closure was achieved in 87 eyes (83.7 %) in the overall sample after the first surgery, with closure rates of 100%, 56%, 84.6%, and 92.6% in groups 1, 2, 3, and 4, respectively. The group 2 was significantly less successful compared to the other three groups (p < 0.05). MH of sizes ≤400 µm was closed in 97.2% of cases after the first surgery, with no significant differences between groups (p = 0.219). MH with sizes over 400 µm was closed in 70.9% of cases after the first surgery, with both groups with air tamponade being significantly less successful than group 1. The nonsupine reading position was subjected to a better subjective evaluation in terms of postoperative comfort and quality of sleep, with no differences between air and SF6 tamponade tolerance. CONCLUSION: PPV with ILM peeling, intraocular tamponade, and positioning remains the basic surgical approach in the treatment of IMH. For MH ≤ 400 µm, a high closure rate can be achieved by combining air tamponade and nonsupine reading position. For macular holes >400 µm, the greatest anatomical success can be achieved by using the SF6 tamponade in combination with the nonsupine reading position.

12.
Ann Biomed Eng ; 44(5): 1753-72, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26307330

RESUMO

This work presents a novel methodology for building a three-dimensional patient-specific eyeball model suitable for performing a fully automatic finite element (FE) analysis of the corneal biomechanics. The reconstruction algorithm fits and smooths the patient's corneal surfaces obtained in clinic with corneal topographers and creates an FE mesh for the simulation. The patient's corneal elevation and pachymetry data is kept where available, to account for all corneal geometric features (central corneal thickness-CCT and curvature). Subsequently, an iterative free-stress algorithm including a fiber's pull-back is applied to incorporate the pre-stress field to the model. A convergence analysis of the mesh and a sensitivity analysis of the parameters involved in the numerical response is also addressed to determine the most influential features of the FE model. As a final step, the methodology is applied on the simulation of a general non-commercial non-contact tonometry diagnostic test over a large set of 130 patients-53 healthy, 63 keratoconic (KTC) and 14 post-LASIK surgery eyes. Results show the influence of the CCT, intraocular pressure (IOP) and fibers (87%) on the numerical corneal displacement (U(Num)) the good agreement of the U(Num) with clinical results, and the importance of considering the corneal pre-stress in the FE analysis. The potential and flexibility of the methodology can help improve understanding of the eye biomechanics, to help to plan surgeries, or to interpret the results of new diagnosis tools (i.e., non-contact tonometers).


Assuntos
Córnea/diagnóstico por imagem , Córnea/fisiopatologia , Paquimetria Corneana/métodos , Topografia da Córnea/métodos , Análise de Elementos Finitos , Processamento de Imagem Assistida por Computador/métodos , Córnea/cirurgia , Feminino , Humanos , Ceratomileuse Assistida por Excimer Laser In Situ , Masculino
13.
J Ophthalmol ; 2015: 437271, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25861463

RESUMO

Purpose. To evaluate the usefulness of microperimetry in the early detection of the ocular anomalies associated with the use of hydroxychloroquine. Methods. Prospective comparative case series study comprising 14 healthy eyes of 7 patients (group A) and 14 eyes of 7 patients under treatment with hydroxychloroquine for the treatment of rheumatologic diseases and without fundoscopic or perimetric anomalies (group B). A comprehensive ophthalmological examination including microperimetry (MP) and spectral-domain optical coherence tomography was performed in both groups. Results. No significant differences were found in mean MP foveal sensitivity between groups (P = 0.18). However, mean MP overall sensitivity was significantly higher in group A (29.05 ± 0.57 dB versus group B, 26.05 ± 2.75 dB; P < 0.001). Significantly higher sensitivity values were obtained in group A in comparison to group B for the three eccentric loci evaluated (P < 0.001). Conclusion. Microperimetry seems to be a useful tool for the early detection of retinal damage in patients treated with hydroxychloroquine.

14.
Mol Ecol Resour ; 15(1): 28-41, 2015 01.
Artigo em Inglês | MEDLINE | ID: mdl-24916682

RESUMO

Restriction site-associated DNA sequencing (RADseq) provides researchers with the ability to record genetic polymorphism across thousands of loci for nonmodel organisms, potentially revolutionizing the field of molecular ecology. However, as with other genotyping methods, RADseq is prone to a number of sources of error that may have consequential effects for population genetic inferences, and these have received only limited attention in terms of the estimation and reporting of genotyping error rates. Here we use individual sample replicates, under the expectation of identical genotypes, to quantify genotyping error in the absence of a reference genome. We then use sample replicates to (i) optimize de novo assembly parameters within the program Stacks, by minimizing error and maximizing the retrieval of informative loci; and (ii) quantify error rates for loci, alleles and single-nucleotide polymorphisms. As an empirical example, we use a double-digest RAD data set of a nonmodel plant species, Berberis alpina, collected from high-altitude mountains in Mexico.


Assuntos
Erros de Diagnóstico , Genética Populacional/métodos , Técnicas de Genotipagem/métodos , Análise de Sequência de DNA/métodos , Berberis/classificação , Berberis/genética , Variação Genética , Genótipo , México
15.
Mol Ecol ; 22(8): 2325-40, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23379795

RESUMO

Knowledge on how landscape heterogeneity shapes host-parasite interactions is central to understand the emergence, dynamics and evolution of infectious diseases. However, this is an underexplored subject, particularly for plant-virus systems. Here, we analyse how landscape heterogeneity influences the prevalence, spatial genetic structure, and temporal dynamics of Pepper golden mosaic and Pepper huasteco yellow vein begomoviruses infecting populations of the wild pepper Capsicum annuum glabriusculum (chiltepin) in Mexico. Environmental heterogeneity occurred at different nested spatial scales (host populations within biogeographical provinces), with levels of human management varying among host population within a province. Results indicate that landscape heterogeneity affects the epidemiology and genetic structure of chiltepin-infecting begomoviruses in a scale-specific manner, probably related to conditions favouring the viruses' whitefly vector and its dispersion. Increased levels of human management of the host populations were associated with higher virus prevalence and erased the spatial genetic structure of the virus populations. Also, environmental heterogeneity similarly shaped the spatial genetic structures of host and viruses. This resulted in the congruence between host and virus phylogenies, which does not seem to be due to host-virus co-evolution. Thus, results provide evidence of the key role of landscape heterogeneity in determining plant-virus interactions.


Assuntos
Begomovirus/genética , Evolução Biológica , Piper nigrum/genética , Piper nigrum/virologia , Begomovirus/patogenicidade , Ecossistema , Interações Hospedeiro-Parasita , Humanos , México , Dados de Sequência Molecular , Piper nigrum/crescimento & desenvolvimento , Doenças das Plantas/virologia , Vírus de Plantas/genética
16.
Eye (Lond) ; 27(1): 14-21, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23222559

RESUMO

Implantation of phakic intraocular lenses (pIOLs) is a reversible refractive procedure, preserving the patient's accommodative function with minimal induction of higher order aberrations compared with corneal photoablative procedures. Despite this, as an intraocular procedure, it has potential risks such as cataracts, chronic uveitis, pupil ovalization, corneal endothelial cell loss, pigmentary dispersion syndrome, pupillary block glaucoma, astigmatism, or endophthalmitis. Currently, only two models of posterior chamber pIOLs are commercially available, the implantable collammer lens (STAAR Surgical Co.) and the phakic refractive lens (PRL; Zeiss Meditec). The number of published reports on the latter is very low, and some concerns still remain about its long-term safety. The present article reviews the published literature on the outcomes after PRL implantation in order to provide a general overview and evaluate its real potential as a surgical refractive option.


Assuntos
Implante de Lente Intraocular/métodos , Miopia/cirurgia , Lentes Intraoculares Fácicas , Catarata/etiologia , Desenho de Equipamento , Humanos , Implante de Lente Intraocular/efeitos adversos , Seleção de Pacientes , Lentes Intraoculares Fácicas/efeitos adversos , Lentes Intraoculares Fácicas/classificação , Cápsula Posterior do Cristalino , Refração Ocular
17.
Artigo em Inglês | MEDLINE | ID: mdl-22747764

RESUMO

OBJECTIVE: To present three clinical cases of diplopia secondary to conjunctival surgery (for tumor of caruncle and recurrent pterygium surgery). PATIENTS AND METHODS: Clinical data of three patients with binocular diplopia and incomitant esotropia associated with compensatory torticollis and duction limitation are shown and discussed. In all cases, a complete ophthalmological examination was performed including ocular motility study, duction test and preoperative evaluation under general anesthesia. RESULTS: The forced duction test was positive in all cases, confirming the diagnosis of restrictive strabismus. Uneventful surgery was performed in all cases in which conjunctival adherences to eye orbit bones were eliminated and the involved extraocular muscle was isolated and freed. Furthermore, some additional treatments were applied to avoid recurrency (subconjunctival and topical corticosteroids, amniotic membrane and therapeutic contact lens). One case presented postoperatively a new conjunctival adherence in spite of such anti-recurrency treatment although with no significant motility alterations associated. CONCLUSIONS: Conjunctival surgery can cause fibrosis and conjunctival adherences leading to restrictive strabismus. The surgical procedure for solving this problem must be performed with special care to avoid complications and recurrencies. The use of antimetabolites or amniotic membrane seems to be recommendable to ensure a satisfactory postoperative outcome.


Assuntos
Complicações Pós-Operatórias , Estrabismo , Túnica Conjuntiva , Diplopia , Humanos , Músculos Oculomotores/cirurgia , Complicações Pós-Operatórias/cirurgia
18.
Mol Ecol ; 20(19): 4182-94, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21899621

RESUMO

Over 95% of the currently cultivated cotton was domesticated from Gossypium hirsutum, which originated and diversified in Mexico. Demographic and genetic studies of this species at its centre of origin and diversification are lacking, although they are critical for cotton conservation and breeding. We investigated the actual and potential distribution of wild cotton populations, as well as the contribution of historical and recent gene flow in shaping cotton genetic diversity and structure. We evaluated historical gene flow using chloroplast microsatellites and recent gene flow through the assessment of transgene presence in wild cotton populations, exploiting the fact that genetically modified cotton has been planted in the North of Mexico since 1996. Assessment of geographic structure through Bayesian spatial analysis, BAPS and Genetic Algorithm for Rule-set Production (GARP), suggests that G. hirsutum seems to conform to a metapopulation scheme, with eight distinct metapopulations. Despite evidence for long-distance gene flow, genetic variation among the metapopulations of G. hirsutum is high (He = 0.894 ± 0.01). We identified 46 different haplotypes, 78% of which are unique to a particular metapopulation, in contrast to a single haplotype detected in cotton cultivars. Recent gene flow was also detected (m = 66/270 = 0.24), with four out of eight metapopulations having transgenes. We discuss the implications of the data presented here with respect to the conservation and future breeding of cotton populations and genetic diversity at its centre of crop origin.


Assuntos
Fluxo Gênico , Gossypium/genética , Dispersão de Sementes , Transgenes , Teorema de Bayes , Conservação dos Recursos Naturais , Geografia , Gossypium/fisiologia , Haplótipos , Proteínas de Plantas/genética , Proteínas Recombinantes/genética
19.
J Evol Biol ; 23(10): 2163-2175, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20840309

RESUMO

Pleistocene climatic oscillations are known to influence the patterns of genetic diversity and the distribution of traits that are the target of selection. Here, we combine phylogeographical and ecological niche modelling (ENM) approaches to explore the influence of historical factors (Pleistocene climatic shifts) and natural selection on the evolution of distyly (two floral morphs) from tristyly (three floral morphs) of Oxalis alpina in the Sky Islands of the Sonoran Desert. Molecular data and ENM indicate that historical factors have had a strong influence on the genetic structure and the geographical distribution of reproductive systems of O. alpina. Moreover, genetic results suggest the possibility that distylous populations do not represent a monophyletic group. We propose that the combined effects of natural selection and genetic drift have influenced the tristyly-distyly transition.


Assuntos
Evolução Biológica , Flores/fisiologia , Magnoliopsida/genética , Modelos Genéticos , Seleção Genética , Arizona , Clima Desértico , Ecossistema , Deriva Genética , Variação Genética , Haplótipos , México , New Mexico , Filogeografia
20.
Eye (Lond) ; 24(6): 1064-70, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19786958

RESUMO

PURPOSE: To assess the interchangeability of central corneal thickness (CCT) measurements between combined scanning-slit/Placido disc topography (Orbscan-II) and specular microscopy (Topcon SP-2000P) in patients who underwent laser in situ keratomileusis (LASIK) for myopia. PATIENTS AND METHODS: We recruited 118 consecutive patients who underwent LASIK for myopia. The CCT was measured using Orbscan-II and Topcon SP-2000P randomly. Orbscan-II and Topcon SP-2000P CCT data were analysed using the paired-sample t-test and the limits of agreement (LoA) were calculated with the method described by Bland-Altman. RESULTS: The average CCT measurements by Orbscan-II and Topcon SP-2000P were 447.55+/-49.78 microm and 461.38+/-35.35 microm, respectively (P<0.0001; mean difference, 13.83+/-22.31 microm; 95% confidence interval, 9.77-17.09 microm). The Bland-Altman plot showed an inverse association between the average and the difference between the devices: Topcon-Orbscan-II=174.23 -0.353xAverage (P<0.01). The widths of the crude and regression-based 95% limits of agreement were 87.45 and 63.72 microm, respectively. CONCLUSIONS: Orbscan-II measurements of CCT after myopic LASIK were significantly lower than those obtained using Topcon SP-2000P. The limits of agreement between the two devices were too broad and, therefore, both pachymetric values cannot be used interchangeably. Further, the tendency towards comparably Orbscan-II readings in thinner corneas precludes that one technique can directly replace the other. This is important for the adequate medium- and long-term follow-up of the growing LASIK patient population.


Assuntos
Córnea/anatomia & histologia , Topografia da Córnea/métodos , Ceratomileuse Assistida por Excimer Laser In Situ , Córnea/diagnóstico por imagem , Córnea/cirurgia , Topografia da Córnea/instrumentação , Humanos , Miopia/cirurgia , Ultrassonografia
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