Practical guide for setting up a Fourier light-field microscope.

A practical guide for the easy implementation of a Fourier light-field microscope is reported. The Fourier light-field concept applied to microscopy allows the capture in real time of a series of 2D orthographic images of microscopic thick dynamic samples. Such perspective images contain spatial and angular information of the light-field emitted by the sample. A feature of this technology is the tight requirement of a double optical conjugation relationship, and also the requirement of NA matching. For these reasons, the Fourier light-field microscope being a non-complex optical system, a clear protocol on how to set up the optical elements accurately is needed. In this sense, this guide is aimed to simplify the implementation process, with an optical bench and off-the-shelf components. This will help the widespread use of this recent technology.

Initial results of endourological treatment of renoureteral lithiasis by means of flexible ureteroscopy and percutaneous surgery in an outpatient procedure in a tertiary care center.

OBJECTIVE: Urinary lithiasis is a prevalent disease with a high socioeconomic impact, where endourological surgery has shown excellent results with minimal complications. For its part, outpatient surgery is an efficient, safe and quality care model. We present our experience in the outpatient endourological treatment of lithiasis and a review of the main series. MATERIAL AND METHODS: Prospective analysis of 85 flexible or percutaneous procedures for the treatment of lithiasis, carried out in our center between January 2021 and April 2022. The main objective was to analyze the rate of unplanned admission and the success and incidence of complications as secondary objectives. The patients were selected following the inclusion criteria of the care process. RESULTS: The mean age was 56 ± 14 years. Urine culture was positive in 13.9% of the patients, 38% had a pre-surgical double-J catheter. Median stone surface was 55 mm 2 (961 ± 323 Hounsfield Units). 73 flexible and 12 percutaneous procedures were performed. 8 patients required immediate unplanned admission and another 2 during the first month. 94% were stone-free at the third month. No intraoperative complications were detected, although 16.5% of the patients presented some type of postoperative complication. CONCLUSION: In our experience, with a strict selection of patients and following a care process with multidisciplinary participation, endourological procedures are feasible and safe in the outpatient setting. Periodic monitoring of the results is essential for the sake of a constant improvement of the process.

Resultados iniciales del tratamiento endourológico de la litiasis renoureteral mediante ureteroscopia flexible y cirugía percutánea en régimen de cirugía mayor ambulatoria en un centro de tercer nivel / Initial results of endourological treatment of renoureteral lithiasis by means of flexible ureteroscopy and percutaneous surgery in an outpatient procedure in a tertiary care center

Objetivo La litiasis urinaria es una enfermedad prevalente y con elevado impacto socioeconómico, donde la cirugía endourológica ha demostrado excelentes resultados con mínimas complicaciones. Por su parte, la cirugía ambulatoria es un modelo asistencial eficiente, seguro y de calidad. Presentamos nuestra experiencia en el tratamiento endourológico ambulatorio de la litiasis renoureteral y una revisión de las principales series. Material y métodos Análisis prospectivo de 85 procedimientos flexibles o percutáneos para el tratamiento de la litiasis, llevados a cabo en nuestro centro entre enero de 2021 y abril de 2022. Se estableció como objetivo principal analizar la tasa de ingreso no planificado y como objetivos secundarios el éxito e incidencia de complicaciones. Los pacientes fueron seleccionados siguiendo los criterios del proceso asistencial. Resultados La edad media fue de 56±14 años. El urocultivo fue positivo en 13,9% de los pacientes, siendo portadores de doble J prequirúrgico 38%. Mediana de superficie litiásica de 55 mm2, con 961±323 Unidades Hounsfield. Se realizaron 73 procedimientos flexibles y 12 percutáneos. Ocho pacientes requirieron ingreso no planificado inmediato y otros dos durante el primer mes. Al tercer mes, 94% se encontraban libre de litiasis. No se detectaron complicaciones intraoperatorias, aunque 16,5% de los pacientes presentaron algún tipo de complicación postoperatoria. Conclusión En nuestra experiencia, con una estricta selección de los pacientes y siguiendo un proceso asistencial con participación multidisciplinar, los procedimientos endourológicos son factibles y seguros en el ámbito ambulatorio. La monitorización periódica de los resultados es fundamental en aras de una mejora constante del proceso (AU)

Objective Urinary lithiasis is a prevalent disease with a high socioeconomic impact, where endourological surgery has shown excellent results with minimal complications. For its part, outpatient surgery is an efficient, safe and quality care model. We present our experience in the outpatient endourological treatment of lithiasis and a review of the main series. Material and methods Prospective analysis of 85 flexible or percutaneous procedures for the treatment of lithiasis, carried out in our center between January 2021 and April 2022. The main objective was to analyze the rate of unplanned admission and the success and incidence of complications as secondary objectives. The patients were selected following the inclusion criteria of the care process. Results The mean age was 56±14 years. Urine culture was positive in 13.9% of the patients, 38% had a pre-surgical double-J catheter. Median stone surface was 55 mm2 (961±323 Hounsfield Units). 73 flexible and 12 percutaneous procedures were performed. 8 patients required immediate unplanned admission and another 2 during the first month. 94% were stone-free at the third month. No intraoperative complications were detected, although 16.5% of the patients presented some type of postoperative complication. Conclusion In our experience, with a strict selection of patients and following a care process with multidisciplinary participation, endourological procedures are feasible and safe in the outpatient setting. Periodic monitoring of the results is essential for the sake of a constant improvement of the process (AU)

Three-dimensional imaging through patterned type-1 microscopy.

We report a scanning non-confocal fluorescence microscopy scheme that provides images with optical sectioning and with a lateral resolution that surpasses by a factor of two the diffraction resolution limit. This technique is based on the type-1 microscopy concept combined with patterned illumination. The method does not require the application of phase-shifting or post-processing algorithms and provides artifact-free superresolved 3D images. We have validated the theory by means of experimental data.

Examining the utility of pinhole-type screens for lightfield display.

The use of microlens arrays for lightfield display has the drawback of providing images with strong chromatic aliasing. To overcome this problem, pinhole-type lightfield monitors are proposed. This paper is devoted to evaluating the capability for such lightfield monitors to offer the user a convincing 3D experience with images with enough brightness and continuous aspect. Thus, we have designed a psychophysical test specifically adapted for lightfield monitors, which allowed us to confirm the usability of pinhole-type monitors.

FIMic: design for ultimate 3D-integral microscopy of in-vivo biological samples.

In this work, Fourier integral microscope (FIMic), an ultimate design of 3D-integral microscopy, is presented. By placing a multiplexing microlens array at the aperture stop of the microscope objective of the host microscope, FIMic shows extended depth of field and enhanced lateral resolution in comparison with regular integral microscopy. As FIMic directly produces a set of orthographic views of the 3D-micrometer-sized sample, it is suitable for real-time imaging. Following regular integral-imaging reconstruction algorithms, a 2.75-fold enhanced depth of field and [Formula: see text]-time better spatial resolution in comparison with conventional integral microscopy is reported. Our claims are supported by theoretical analysis and experimental images of a resolution test target, cotton fibers, and in-vivo 3D-imaging of biological specimens.

Resolution improvements in integral microscopy with Fourier plane recording.

Integral microscopes (IMic) have been recently developed in order to capture the spatial and the angular information of 3D microscopic samples with a single exposure. Computational post-processing of this information permits to carry out a 3D reconstruction of the sample. By applying conventional algorithms, both depth and also view reconstructions are possible. However, the main drawback of IMic is that the resolution of the reconstructed images is low and axially heterogeneous. In this paper, we propose a new configuration of the IMic by placing the lens array not at the image plane, but at the pupil (or Fourier) plane of the microscope objective. With this novel system, the spatial resolution is increased by factor 1.4, and the depth of field is substantially enlarged. Our experiments show the feasibility of the proposed method.

Diabetes screening by telecentric digital holographic microscopy.

Diabetes is currently the world's fastest growing chronic disease and it is caused by deficient production of insulin by the endocrine pancreas or by abnormal insulin action in peripheral tissues. This results in persistent hyperglycaemia that over time may produce chronic diabetic complications. Determination of glycated haemoglobin level is currently the gold standard method to evaluate and control sustained hyperglycaemia in diabetic people. This measurement is currently made by high-performance liquid chromatography, which is a complex chemical process that requires the extraction of blood from the antecubital vein. To reduce the complexity of that measurement, we propose a fully-optical technique that is based in the fact that there are changes in the optical properties of erythrocytes due to the presence of glucose-derived adducts in the haemoglobin molecule. To evaluate these changes, we propose to perform quantitative phase maps of erythrocytes by using telecentric digital holographic microscopy. Our experiments show that telecentric digital holographic microscopy allows detecting, almost in real time and from a single drop of blood, significant differences between erythrocytes of diabetic patients and healthy patients. Besides, our phase measurements are well correlated with the values of glycated haemoglobin and the blood glucose values.

Prescription for antiresorptive therapy in Mexican patients with rheumatoid arthritis: is it time to reevaluate the strategies for osteoporosis prevention?

Glucocorticoids are frequently used in rheumatoid arthritis (RA) in order to alleviate symptoms of joint inflammation, retard erosions and to treat extra-articular manifestations, although these drugs may increase the risk of bone mineral loss and osteoporotic fractures. To date, in Mexico there are no studies that identify the frequency of patients with RA with corticosteroids, receiving therapy for osteoporosis. Therefore, we evaluated the prevalence and factors related to the prescription of antiresorptives in 520 Mexican patients with RA. We used a multivariate model to identify variables associated with antiresorptives prescription. We identified that although 79% of patients were under treatment with glucocorticoids, only 13% received antiresorptive agents as preventive therapy for osteoporosis. The multivariate analysis identified that higher proportions of antiresorptive drugs prescriptions were associated with female patients (OR 11.40, 95% CI: 1.5-84.3, P = 0.02), an age of 40 years or more (OR 3.22, 95% CI: 1.3-8.3, P = 0.02) and to consume a lower number of cointerventions with other drugs (OR 1.09, 95% CI: 1.0-1.2, P = 0.03). Corticosteroid treatment was not associated with the prescription of antiresorptives (P = 0.31). In conclusion, a low proportion of Mexicans with RA receive antiresorptive therapy independently regardless of whether they consume or not chronically corticosteroids. Additional strategies should be evaluated to encourage the prevention and early treatment for osteoporosis in patients with RA.

High-resolution far-field integral-imaging camera by double snapshot.

In multi-view three-dimensional imaging, to capture the elemental images of distant objects, the use of a field-like lens that projects the reference plane onto the microlens array is necessary. In this case, the spatial resolution of reconstructed images is equal to the spatial density of microlenses in the array. In this paper we report a simple method, based on the realization of double snapshots, to double the 2D pixel density of reconstructed scenes. Experiments are reported to support the proposed approach.

3D integral imaging display by smart pseudoscopic-to-orthoscopic conversion (SPOC).

Previously, we reported a digital technique for formation of real, non-distorted, orthoscopic integral images by direct pickup. However the technique was constrained to the case of symmetric image capture and display systems. Here, we report a more general algorithm which allows the pseudoscopic to orthoscopic transformation with full control over the display parameters so that one can generate a set of synthetic elemental images that suits the characteristics of the Integral-Imaging monitor and permits control over the depth and size of the reconstructed 3D scene.

Optical implementation of micro-zoom arrays for parallel focusing in integral imaging.

We report 3D integral imaging with an electronically tunable-focal-length lens for improved depth of field. The micro-zoom arrays are generated and implemented based on the concept of parallel apodization. To the best of our knowledge, this is the first report of parallel dynamic focusing in integral imaging based on the use of micro-zoom arrays.

Reduction of spherical-aberration impact in microscopy by wavefront coding.

In modern high-NA optical scanning instruments, like scanning microscopes, the refractive-index mismatch between the sample and the immersion medium introduces a significant amount of spherical aberration when imaging deep inside the specimen, spreading out the impulse response. Since such aberration depends on the focalization depth, it is not possible to achieve a static global compensation for the whole 3D sample in scanning microscopy. Therefore a depth-variant impulse response is generated. Consequently, the design of pupil elements that increase the tolerance to this aberration is of great interest. In this paper we report a hybrid technique that provides a focal spot that remains almost invariant in the depth-scanning processing of thick samples. This invariance allows the application of 3D deconvolution techniques to that provide an improved recovery of the specimen structure when imaging thick samples.

Digital slicing of 3D scenes by Fourier filtering of integral images.

We present a novel technique to extract depth information from 3D scenes recorded using an Integral Imaging system. The technique exploits the periodic structure of the recorded integral image to implement a Fourier-domain filtering algorithm. A proper projection of the filtered integral image permits reconstruction of different planes that constitute the 3D scene. The main feature of our method is that the Fourier-domain filtering allows the reduction of out-of-focus information, providing the InI system with real optical sectioning capacity.

Blood pressure is not associated with haematoma enlargement in acute intracerebral haemorrhage.

BACKGROUND AND PURPOSE: We performed an observational study that compared baseline and subsequent blood pressure (BP) measurements and its association with haematoma enlargement (HE) in patients with intracerebral haemorrhage (ICH). METHODS: We prospectively studied consecutive patients with supratentorial spontaneous ICH within the first 6 h after the onset of symptoms. HE was defined as an increase >or=33% in the volume of haematoma on the CT obtained 24-48 h after the onset of symptoms as compared with the CT at admission. We recorded systolic BP (SBP), diastolic BP (DBP) and mean BP (MBP) at admission and at 6, 12, 18 and 24 h after onset; the maximum SBP, DBP and MBP during the study period; the maximum SBP and DBP within intervals; the mean of all BP readings; administration of antihypertensive agents. RESULTS: We studied 60 patients whose mean age was 72.1 +/- 11.3 years. HE was observed in 27 (45%) patients. No statistically significant differences were observed in any of the analyses that compared BP parameters between the HE and non-HE groups (two-way anova). CONCLUSIONS: In an exploratory analysis, we did not find an association between BP and HE within the first 24 h after an acute ICH.

Motor changes during sertraline treatment in depressed patients with Parkinson's disease*.

BACKGROUND: Pharmacological interventions to treat depressive symptoms associated with Parkinson's disease (PD) are limited. Whether selective serotonine re-uptake inhibitors increase parkinsonism or have clinically significant interactions with antiparkinsonian drugs is unresolved. PURPOSE: We used a naturalistic approach to prospectively investigate the long-term effects on motor status of adding sertraline in a large sample of community-dwelling PD patients with depressive symptoms. METHODS: Main outcome measure was the motor part of the Unified PD Rating Scale (UPDRS) at baseline and at 1-, 3-, and 6-month follow-up. Secondary measures were the change in antiparkinsonian drugs expressed as total levodopa equivalent dose and the scores of the Hospital Anxiety and Depression Scale (HADS). Of the 374 patients included, 310 (82%) completed the study. RESULTS: Treatment with sertraline (mean dose 66.0 +/- 29.8 mg) resulted in improvement in all UPDRS domains along with a significant decrease of the HADS scores. A modest but significant increase of the total dose of levodopa, without significant change of total levodopa equivalent dose, was observed. Almost 8% of patients discontinued medication for adverse events, mainly related to the gastrointestinal system. CONCLUSIONS: Although worsening of tremor was observed in some patients, active management of depression with sertraline appears to have a positive impact on parkinsonism.

Filter performance parameters for vectorial high-aperture wave fields.

Performance parameters have been presented that can be used to compare the focusing performance of different optical systems, including the effect of pupil filters. These were originally given for the paraxial case and recently extended to the high-aperture scalar regime. We generalize these parameters to the full vectorial case for an aplanatic optical system illuminated by a plane-polarized wave. The behavior of different optical systems is compared.

[Retinal and brain infarctions secondary to acute carotid thrombosis in ovarian hyperstimulation syndrome]. / Infartos retiniano y cerebral secundarios a trombosis carotídea aguda en el síndrome de hiperestimulación ovárica.

INTRODUCTION: Ovarian hyperstimulation syndrome (OHSS) is an uncommon but potentially life-threatening iatrogenic condition that may appear following ovulation induction in the course of some fertility treatments. This may lead to further complications, some of which may be severe, such as thromboembolic events. Though rarely, it can therefore be a potential cause of stroke. CLINICAL CASE: We report the case of a 34-year old woman under ovulation induction treatment who developed retinal and brain infarctions secondary to internal carotid occlusion. Oral anticoagulation was administered and recovery was good in spite of the persistence of carotid occlusion in follow-up magnetic ressonance imaging- angiographies. CONCLUSIONS: This is the first case of carotid occlusion following an OHSS reported in Spain and the eighth one published in the literature. Current literature on cerebrovascular complications in OHSS is also briefly reviewed.