Temporal Evaluation of the Surface Area of Treated Skin Ulcers Caused by Cutaneous Leishmaniasis and Relation with Optical Parameters in an Animal Model: A Proof of Concept.

Cutaneous leishmaniasis (CL) is a neglected disease caused by an intracellular parasite of the Leishmania genus. CL lacks tools that allow its understanding and treatment follow-up. This article presents the use of metrical and optical tools for the analysis of the temporal evolution of treated skin ulcers caused by CL in an animal model. Leishmania braziliensis and L. panamensis were experimentally inoculated in golden hamsters, which were treated with experimental and commercial drugs. The temporal evolution was monitored by means of ulcers' surface areas, as well as absorption and scattering optical parameters. Ulcers' surface areas were obtained via photogrammetry, which is a procedure that allowed for 3D modeling of the ulcer using specialized software. Optical parameters were obtained from a spectroscopy study, representing the cutaneous tissue's biological components. A one-way ANOVA analysis was conducted to identify relationships between both the ulcers' areas and optical parameters. As a result, ulcers' surface areas were found to be related to the following optical parameters: epidermis thickness, collagen, keratinocytes, volume-fraction of blood, and oxygen saturation. This study is a proof of concept that shows that optical parameters could be associated with metrical ones, giving a more reliable concept during the assessment of a skin ulcer's healing.

Diffuse Reflectance Parameters of Treated Leishmaniasis Cutaneous Ulcers and Association with Histopathologies in an Animal Model: A Proof of Concept.

Cutaneous leishmaniasis (CL) is a parasitic disease that produces chronic skin ulcers. Although it has a worldwide presence, it is a neglected disease that still requires novel tools for its management. In order to study the use of optical tools in CL, this article presents a preliminary study of the correlation between CL histopathological and optical parameters. Optical parameters correspond to absorption and scattering coefficients obtained from diffuse reflectance spectra of treated CL in golden hamsters. Independently, histopathological data were collected from the same hamsters. As a result, after Spearman correlation and the Kruskal-Wallis test, inverse correlation was found between absorption/scattering optical parameters and inflammatory histopathological values, such as the scattering parameter related to the diameter of fibroblasts with the histopathological parameters of fibrosis, polymorphonuclear neutrophils, lymphocytes, plasmocytes, hyperplasia, and Leishmania, and the absorption parameter oxygen saturation showed a relation with the granulation tissue histopathological parameter. These correlations agree with the expected behavior of tissue composition during the healing process in CL. The results correspond to a proof of concept that shows that optical diffuse reflectance-based tools and methods could be considered as an alternative to assist in CL diagnosis and treatment follow-up.

Estimation of Biological Parameters of Cutaneous Ulcers Caused by Leishmaniasis in an Animal Model Using Diffuse Reflectance Spectroscopy.

Cutaneous leishmaniasis (CL) is a neglected tropical disease that requires novel tools for its understanding, diagnosis, and treatment follow-up. In the cases of other cutaneous pathologies, such as cancer or cutaneous ulcers due to diabetes, optical diffuse reflectance-based tools and methods are widely used for the investigation of those illnesses. These types of tools and methods offer the possibility to develop portable diagnosis and treatment follow-up systems. In this article, we propose the use of a three-layer diffuse reflectance model for the study of the formation of cutaneous ulcers caused by CL. The proposed model together with an inverse-modeling procedure were used in the evaluation of diffuse-reflectance spectral signatures acquired from cutaneous ulcers formed in the dorsal area of 21 golden hamsters inoculated with Leishmanisis braziliensis. As result, the quantification of the model's variables related to the main biological parameters of skin were obtained, such as: diameter and volumetric fraction of keratinocytes, collagen; volumetric fraction of hemoglobin, and oxygen saturation. Those parameters show statistically significant differences among the different stages of the CL ulcer formation. We found that these differences are coherent with histopathological manifestations reported in the literature for the main phases of CL formation.

An Optical Diffuse Reflectance Model for the Characterization of a Si Wafer with an Evaporated SiO2 Layer.

Thin films are a type of coating that have a very wide spectrum of applications. They may be used as single layers or composed in multilayer stacks, which significantly extend their applications. One of the most commonly used material for thin films is silicon dioxide, SiO2. Although there are other tools that can be used to measure the thickness of SiO2 films, these tools are very complex and sophisticated. In this article, we propose the use of an exponential two-layer light-material interaction model, throughout its diffuse reflectance spectra, as an alternative for the measurement of the thickness of evaporated SiO2 on Si wafers. The proposed model is evaluated experimentally by means of a 980-nm-thick SiO2 layer evaporated on a Si wafer. The results show that the proposed model has a strong correlation with the thickness measurements obtained using commercial equipment.

Accurate Region-of-Interest Recovery Improves the Measurement of the Cell Migration Rate in the In Vitro Wound Healing Assay.

The wound healing assay is widely used for the quantitative analysis of highly regulated cellular events. In this essay, a wound is voluntarily produced on a confluent cell monolayer, and then the rate of wound reduction (WR) is characterized by processing images of the same regions of interest (ROIs) recorded at different time intervals. In this method, sharp-image ROI recovery is indispensable to compensate for displacements of the cell cultures due either to the exploration of multiple sites of the same culture or to transfers from the microscope stage to a cell incubator. ROI recovery is usually done manually and, despite a low-magnification microscope objective is generally used (10x), repositioning imperfections constitute a major source of errors detrimental to the WR measurement accuracy. We address this ROI recovery issue by using pseudoperiodic patterns fixed onto the cell culture dishes, allowing the easy localization of ROIs and the accurate quantification of positioning errors. The method is applied to a tumor-derived cell line, and the WR rates are measured by means of two different image processing software. Sharp ROI recovery based on the proposed method is found to improve significantly the accuracy of the WR measurement and the positioning under the microscope.

Performance Characterization of an xy-Stage Applied to Micrometric Laser Direct Writing Lithography.

This article concerns the characterization of the stability and performance of a motorized stage used in laser direct writing lithography. The system was built from commercial components and commanded by G-code. Measurements use a pseudo-periodic-pattern (PPP) observed by a camera and image processing is based on Fourier transform and phase measurement methods. The results report that the built system has a stability against vibrations determined by peak-valley deviations of 65 nm and 26 nm in the x and y directions, respectively, with a standard deviation of 10 nm in both directions. When the xy-stage is in movement, it works with a resolution of 0.36 µm, which is an acceptable value for most of research and development (R and D) microtechnology developments in which the typical feature size used is in the micrometer range.

Bare platinum coils vs. HydroCoil in the treatment of unruptured intracranial aneurysms-A single center randomized controlled study.

PURPOSE: The HydroCoil Embolic System (HES) was developed to improve aneurysm filling to provide superior occlusion efficacy, reduce retreatment rates and enhance long-term durability. We performed a randomized clinical trial to compare the effectiveness of bare platinum coils (BPC) vs. HES for unruptured intracranial aneurysms. METHODS: Ninety-six patients underwent endovascular coiling of unruptured intracranial aneurysms. The aneurysms were randomized equally to receive BPC or HES. Immediate angiographic results, number of coils used and complications were evaluated and all cases had 12-month follow-up angiography. RESULTS: Immediate angiographic results demonstrated that 84.0% of aneurysms treated with HES were completely occluded compared to 76.1% of aneurysms treated with BPC (p=0.3310). The mean number of coils utilized to fill the aneurysm was significantly lower in the HES arm (5.04 vs. 6.93). Additional adjunctive techniques were performed in 51.1% of all cases. There were seven patients (7.3%) with postoperative complications during the study period. The coil type used during the treatment did not demonstrate any significant differences on the overall recurrence rate (HES - 18.0%, BPC - 17.4%, p=0.9712). There was a statistically significant difference in the aneurysm size and the neck width between completely occluded aneurysms and aneurysms with residual flow in both immediate angiographic and mid-term follow-up. CONCLUSIONS: Overall, aneurysm size and neck width are the main risk factors associated with aneurysm recurrence. HES compared to BPC required less total number of coils to provide a denser aneurysm filling. However, there were equivocal results with both devices, at the mid-term angiographic follow-up.

CT and MRI imaging of the brain in MELAS syndrome.

BACKGROUND: MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, stroke-like episodes) is a rare, multisystem disorder which belongs to a group of mitochondrial metabolic diseases. As other diseases in this group, it is inherited in the maternal line. CASE REPORT: In this report, we discussed a case of a 10-year-old girl with clinical and radiological picture of MELAS syndrome. We would like to describe characteristic radiological features of MELAS syndrome in CT, MRI and MR spectroscopy of the brain and differential diagnosis. CONCLUSIONS: The rarity of this disorder and the complexity of its clinical presentation make MELAS patients among the most difficult to diagnose. Brain imaging studies require a wide differential diagnosis, primarily to distinguish between MELAS and ischemic stroke. Particularly helpful are the MRI and MR spectroscopy techniques.

[Objective retinal nerve fiber laser assessment by scanning laser polarimetry in patients with chiasmal compression]. / Obiektywna ocena zmian warstwy wlókien nerwowych siatkówki za pomoca badania GDx u pacjentów z uciskiem dróg wzrokowych.

PURPOSE: To assess the evaluation ability of retinal nerve fiber layer (RNFL) in patients with visual tracts' compression and to assess the correlation between visual field loss and changes in RNFL. MATERIAL AND METHODS: Polarimetric RNFL analysis (scanning laser polarimeter- NFA/GDx, software version 1.0.16, LDT(inc)) and kinetic perimetry were done in 41 eyes with different types of optic chiasma compression and in 40 healthy eyes, age matched controls. RESULTS: In eyes with optic chiasma compression most of the GDx parameters were statistically different from the control group (P<0.05). In eyes with normal visual fields and with optic chiasma compression most of GDx parameters were statistically different from the other analyzed groups. CONCLUSIONS: GDx may be a helpful tool in diagnosis of optic chiasma diseases. GDx is a useful visual prognostic indicator in the preoperative assessment of optic chiasma compression. Objective RNFL assessment is especially important in patients with serious visual field loss and poor visual acuity.