A rapid method for measuring intraocular lens power in vitro with a focimeter.

In this paper we describe a new method for measuring the intraocular lens (IOL) power using a focimeter, a negative ophthalmic lens and a saline solution (0.9% NaCl). To test this we measured the power of 58 different IOLs and we compared them with the power stated by the manufacturer. Despite the limitations, the results show a good correlation.

Anterior Scleral Thickness Profile in Keratoconus.

PURPOSE: Considering that peripheral corneal thinning occurs in keratoconus (KC), the anterior scleral thickness (AST) profile was measured to compare thickness variations in healthy and KC eyes across several meridians. METHODS: This cross-sectional case-control study comprised 111 eyes of 111 patients: 61 KC eyes and 50 age- and axial-length-matched healthy eyes. The AST was explored at three scleral eccentricities (1, 2, and 3 mm from the scleral spur) across four scleral zones (nasal, temporal, superior, and inferior) by using swept-source optical coherence tomography. The AST variations among eccentricities and scleral regions within and between groups were investigated. RESULTS: The AST significantly varied with scleral eccentricity in healthy eyes over the temporal meridian (p = 0.009), whereas in KC eyes, this variation was observed over the nasal (p = 0.001), temporal (p = 0.029) and inferior (p = 0.006) meridians. The thinnest point in both groups was 2 mm posterior to the scleral spur (p < 0.001). The sclera was thickest over the inferior region (control 581 ± 52 µm, KC 577 ± 67 µm) and thinnest over the superior region (control 448 ± 48 µm, KC 468 ± 58 µm) in both populations (p < 0.001 for all eccentricities). The AST profiles were not significantly different between groups (p > 0.05). The inferior-superior thickness asymmetry was statistically different 2 mm posterior to the scleral spur between groups (p = 0.009), specifically with subclinical KC (p = 0.03). There is a trend where the asymmetry increases, although not significantly, with the KC degree (p > 0.05). CONCLUSIONS: KC eyes presented significant thickness variations among eccentricities over the paracentral sclera. Although AST profiles did not differ between groups, the inferior-superior asymmetry differences demonstrated scleral changes over the vertical meridian in KC that need further investigation.

Effects of cataract surgery on blinking.

PURPOSE: To assess the effects of cataract surgery on the spontaneous blinking pattern and blinking kinematics. SETTING: FISABIO Oftalmología Médica Eye Hospital, Valencia, Spain. DESIGN: Observational descriptive clinical study. METHOD: Patients with senile cataract were evaluated before (visit 1) and at 1 month (visit 2) and 3 months (visit 3) after undergoing phacoemulsification cataract surgery. The blinking of patients was recorded for 90 seconds using an eye-tracking device. Blinks were analyzed by means of image analysis to obtain a noninvasive detailed description of blinking including blink rate, number of complete and incomplete blinks, percentage of incomplete blinks, and kinematic parameters, including amplitude, closing, contact, opening, and total durations and closing and opening speeds. RESULTS: 50 patients were included in this study. The blink rate was significantly smaller at visit 3 compared with baseline ( P = .03) and visit 2 ( P = .001). Likewise, the number of complete blinks was significantly smaller, and the percentage of incomplete blinks was significantly higher at 3 months postoperatively compared with baseline ( P = .02 and P = .01, respectively), although no differences were observed at 1 month postoperatively ( P > .05). Conversely, no differences in the number of incomplete blinks or any kinematic parameter were observed between visits ( P = .12). CONCLUSIONS: Cataract surgery significantly altered the blinking pattern at 3 months postoperatively, although kinematic parameters remained unvaried. Clinicians should be aware of potential alterations in blinking after phacoemulsification cataract surgery and the implications this may have on the ocular surface of patients.

Chromatic Contrast Sensitivity Functions and Colour Discrimination in Smoker Patients.

In this study, effects of smoking on colour vision with the Farnsworth−Munsell 100 Hue test (FM100h) and achromatic (A), red-green (RG), and blue-yellow (BY) contrast sensitivity functions were evaluated. In total, 50 non-smoker controls and 25 smokers, divided into two groups (group 1, less than 10 cigarettes per day, with 15 patients, and group 2, >10 cigarettes per day, with 10 patients) took part in the experiments. Best-corrected visual acuity (BCVA), FM100h, and A, RG, and BY contrast sensitivity functions were measured. Total and partial RG and BY error scores (TES and PTES) and colour axis index (CA) were used in the analysis. No differences between smoker and non-smoker groups were found in BCVA, CA and A and BY contrast sensitivity, but TES and PTES values and RG contrast sensitivity at 1 cpd were statistically different. Differences between smoker groups were not significant. Error scores in smokers were positively correlated with the number of cigarettes smoked per day, and in BY also with age. Tobacco caused discrimination losses in both chromatic mechanisms but affected the red-green pathway more than the blue-yellow, and therefore, a partial RG score of FM100h test seems to be a good predictor of smoker colour deficiencies.

The GB4.0 Platform, an All-In-One Tool for CRISPR/Cas-Based Multiplex Genome Engineering in Plants.

CRISPR/Cas ability to target several loci simultaneously (multiplexing) is a game-changer in plant breeding. Multiplexing not only accelerates trait pyramiding but also can unveil traits hidden by functional redundancy. Furthermore, multiplexing enhances dCas-based programmable gene expression and enables cascade-like gene regulation. However, the design and assembly of multiplex constructs comprising tandemly arrayed guide RNAs (gRNAs) requires scarless cloning and is still troublesome due to the presence of repetitive sequences, thus hampering a more widespread use. Here we present a comprehensive extension of the software-assisted cloning platform GoldenBraid (GB), in which, on top of its multigene cloning software, we integrate new tools for the Type IIS-based easy and rapid assembly of up to six tandemly-arrayed gRNAs with both Cas9 and Cas12a, using the gRNA-tRNA-spaced and the crRNA unspaced approaches, respectively. As stress tests for the new tools, we assembled and used for Agrobacterium-mediated stable transformation a 17 Cas9-gRNAs construct targeting a subset of the Squamosa-Promoter Binding Protein-Like (SPL) gene family in Nicotiana tabacum. The 14 selected genes are targets of miR156, thus potentially playing an important role in juvenile-to-adult and vegetative-to-reproductive phase transitions. With the 17 gRNAs construct we generated a collection of Cas9-free SPL edited T1 plants harboring up to 9 biallelic mutations and showing leaf juvenility and more branching. The functionality of GB-assembled dCas9 and dCas12a-based CRISPR/Cas activators and repressors using single and multiplexing gRNAs was validated using a Luciferase reporter with the Solanum lycopersicum Mtb promoter or the Agrobacterium tumefaciens nopaline synthase promoter in transient expression in Nicotiana benthamiana. With the incorporation of the new web-based tools and the accompanying collection of DNA parts, the GB4.0 genome edition turns an all-in-one open platform for plant genome engineering.

Evaluation of Intraocular Pressure and Other Biomechanical Parameters to Distinguish between Subclinical Keratoconus and Healthy Corneas.

(1) Purpose: To assess the main corneal response differences between normal and subclinical keratoconus (SCKC) with a Corvis® ST device. (2) Material and Methods: We selected 183 eyes of normal patients, of a mean age of 33 ± 9 years and 16 eyes of patients with SCKC of a similar mean age. We measured best corrected visual acuity (BCVA) and corneal topography with a Pentacam HD device to select the SCKC group. Biomechanical measurements were performed using the Corvis® ST device. We carried out a non-parametric analysis of the data with SPSS software (Wilcoxon signed rank-test). (3) Results: We found statistically significant differences between the control and SCKC groups in some corneal biomechanical parameters: first and second applanation time (p = 0.05 and p = 0.02), maximum deformation amplitude (p = 0.016), highest concavity radius (p = 0.007), and second applanation length and corneal velocity ((p = 0.039 and p = 0.016). (4) Conclusions: Our results show that the use of normalised biomechanical parameters provided by noncontact tonometry, combined with a discriminant function theory, is a useful tool for detecting subclinical keratoconus.

[Hospital environment variables that affect the risk of infections of cancer patients and recipients of hematopoietic precursor transplants: Design, care processes, microbiological quality of air and water]. / Parte II. Variables del ambiente hospitalario que inciden en el riesgo de infecciones de pacientes con cáncer y receptores de trasplante de precursores hematopoyéticos: Diseño, procesos asistenciales, calidad microbiológica del aire y agua.

The hospital environment is a potential source of exposure to pathogens such as bacteria, fungi and parasites that can cause infections in patients with cancer including transplanted hematopoietic precursors. To mitigate this risk, the design, construction and location elements of the patient care area must be taken into account. Recommendations are given to provide safe environments, including aspects related to characteristics and use of a protected environment, the definition of critical processes, clinical teams dedicated to the care of patients, suggestions of areas to be monitored, the microbiological quality of air and water.

Repeatability of in-vitro optical quality measurements of intraocular lenses with a deflectometry technique effect of the toricity.

AIM: To evaluate the repeatability of an optical device for measuring the Zernike coefficients of toric intraocular lenses (IOLs) and assess whether its toricity has any impact in its repeatability. METHODS: An experienced technician used the NIMO TR1504 to measure the Zernike coefficients 30 times for an aperture of 4.50 mm for all lenses included. The IOLs included were divided into two group: toric and non-toric ones. The cylindrical powers of the toric lenses included in the present study were 1.00, 1.50, 2.25, 3.00 and 3.75 D. Finally, the repeatability of the NIMO TR1504 was described in terms of within subject standard deviation (Sw) and repeatability limit. RESULTS: The Sw was smaller than 0.011 µm for both lens groups and all Zernike coefficients, and the difference between both groups was smaller than 0.004 µm for all Zernike coefficients. Regarding the repeatability limit, this value was smaller than 0.025 µm for the toric lens group, and smaller than 0.031 µm for the non-toric lens one for all Zernike coefficients. Furthermore, the maximum difference between both lens groups was 0.010 µm. CONCLUSION: The repeatability of the NIMO TR1504 to measure the optical quality is high and independent of the lens toricity. These results reflect that this system is robust and could be used to measure the in-vitro optical quality of either toric or non-toric IOLs.

Extensively drug-resistant Acinetobacter baumannii isolated in a university hospital: Role of inter-hospital transmission.

INTRODUCTION: Acinetobacter baumannii causes severe infections that primarily affect intensive care unit (ICU) patients. It has a high prevalence of multidrug resistance, including carbapenems, and a high potential for intra-hospital and inter-hospital transmission. The aim of this study was to determine the origin of extensively drug-resistant (XDR) A. baumannii isolates in our hospital during 2009. METHODOLOGY: This was an observational retrospective study. Isolates of A. baumannii were obtained from patients hospitalized during 2009. XDR isolates were defined using criteria published by Magiorakos et al.. The isolates were classified as community acquired, hospital acquired, and inter-hospital transmission. RESULTS: A total of 48 isolates of A. baumannii were isolated during 2009, corresponding to 34 patients. Of these, 18 (53%) were susceptible, 6 (18%) were multidrug resistant (MDR), and 10 (29%) were XDR. Of the 10 XDR isolates, 9 were isolated from patients transferred from other hospitals. The median time of hospitalization in origin hospitals was 17 days, while the median time of hospitalization in the study hospital, previous to isolation of A. baumannii, was 1 day. A total of 6 out of 10 patients had a positive culture taken on the day of admission. None of the patients shared a clinical ward or time during hospitalization. Genotypic characterization demonstrated the existence of two clones (A and B) which were geographically associated with patients transferred from two different regions of the country. CONCLUSIONS: During 2009, all XDR A. baumannii isolates were recovered from patients coming from other hospitals, indicative of inter-hospital transmission.

Clostridium difficile infection in Chilean patients submitted to hematopoietic stem cell transplantation.

INTRODUCTION: Patients submitted to hematopoietic stem cell transplantation have an increased risk of Clostridium difficile infection and multiple risk factors have been identified. Published reports have indicated an incidence from 9% to 30% of transplant patients however to date there is no information about infection in these patients in Chile. METHODS: A retrospective analysis was performed of patients who developed C. difficile infection after hematopoietic stem cell transplantations from 2000 to 2013. Statistical analysis used the Statistical Package for the Social Sciences software. RESULTS: Two hundred and fifty patients were studied (mean age: 39 years; range: 17-69), with 147 (59%) receiving allogeneic transplants and 103 (41%) receiving autologous transplants. One hundred and ninety-two (77%) patients had diarrhea, with 25 (10%) cases of C. difficile infection being confirmed. Twenty infected patients had undergone allogeneic transplants, of which ten had acute lymphoblastic leukemia, three had acute myeloid leukemia and seven had other diseases (myelodysplastic syndrome, chronic myeloid leukemia, severe aplastic anemia). In the autologous transplant group, five patients had C. difficile infection; two had multiple myeloma, one had amyloidosis, one had acute myeloid leukemia and one had germinal carcinoma. The overall incidence of C. difficile infection was 4% within the first week, 6.4% in the first month and 10% in one year, with no difference in overall survival between infected and non-infected groups (72.0% vs. 67.6%, respectively; p-value=0.56). Patients infected after allogeneic transplants had a slower time to neutrophil engraftment compared to non-infected patients (17.5 vs. 14.9 days, respectively; p-value=0.008). In the autologous transplant group there was no significant difference in the neutrophil engraftment time between infected and non-infected patients (12.5 days vs. 11.8 days, respectively; p-value=0.71). In the allogeneic transplant group, the median time to acute graft-versus-host disease was similar between the two groups (p-value=0.08), as was the incidence of grades 1-4 acute graft-versus-host disease (40% vs. 48%; p-value >0.05). CONCLUSION: The incidence of C. difficile infection after hematopoietic stem cell transplantation was low, with a significant number of cases occurring shortly after transplantation. Allogeneic transplants had a three-time higher risk of infection compared to autologous transplants, but this was not associated with increased mortality, decreased overall survival or higher risk of acute graft-versus-host disease.

Parte II. Variables del ambiente hospitalario que inciden en el riesgo de infecciones de pacientes con cáncer y receptores de trasplante de precursores hematopoyéticos: Diseño, procesos asistenciales, calidad microbiológica del aire y agua / Hospital environment variables that affect the risk of infections of cancer patients and recipients of hematopoietic precursor transplants: Design, care processes, microbiological quality of air and water

Resumen El ambiente hospitalario es una fuente potencial de exposición a patógenos como bacterias, hongos y parásitos, que pueden provocar infecciones en pacientes con cáncer incluyendo receptores de trasplante de precursores hematopoyéticos. Para aminorar este riesgo, se deben tener en cuenta los elementos de diseño, construcción y emplazamiento del área de atención de pacientes. Se entregan recomendaciones para proveer ambientes seguros, incluyendo características y uso de ambiente protegido, la definición de procesos críticos, equipos clínicos destinados a la atención de pacientes, sugerencias de ámbitos a supervisar y aspectos relativos a la calidad microbiológica del aire y agua.

The hospital environment is a potential source of exposure to pathogens such as bacteria, fungi and parasites that can cause infections in patients with cancer including transplanted hematopoietic precursors. To mitigate this risk, the design, construction and location elements of the patient care area must be taken into account. Recommendations are given to provide safe environments, including aspects related to characteristics and use of a protected environment, the definition of critical processes, clinical teams dedicated to the care of patients, suggestions of areas to be monitored, the microbiological quality of air and water.

Assessment of hospital daily cleaning practices using ATP bioluminescence in a developing country.

UNLABELLED: Visual assessment of surfaces may not be enough to document the level of cleanliness in the hospital setting. It is necessary to introduce quantitative methods to document the results of this practice. OBJECTIVE: To evaluate the efficacy of hospital terminal cleaning procedures, using an adenosine triphosphate (ATP) bioluminescence method in a teaching hospital. METHOD: During 2008 we conducted an evaluation using ATP bioluminescence LIGHTNING MVP™ (Arquimed) of external and internal housekeeping service. After conducting an initial evaluation we implemented education of cleaning practices and finally we did a post intervention evaluation. Using chi-square method we compared prior versus after cleaning, quality of cleaning performed by external versus internal personnel, single versus double terminal cleaning procedures and prior versus after intervention. A finding of three RLU or less was considered a clean surface. RESULTS: We performed 198 evaluations in 33 patient units and nine OR. Internal personnel accomplished 25.37% of clean surfaces before and 80% after the education intervention (p=0.01). In contrast, external personnel obtained 68.8% before and 73.33% after intervention (p=0.3). CONCLUSIONS: This study suggests that visual assessment is not enough to ensure quality of the process and it is necessary to document the level of cleanliness by quantitative methods.

A simple description of age-related changes in crystalline lens thickness.

PURPOSE: An increase in lens thickness is often described as a linear function of age. However, contradictory opinions exist about whether the lens thickness continues to increase after 50 years of age. Differences in slope exist between this increase in younger and older people, but these findings are inconsistent with the linear behavior of an increase in the lens thickness throughout life. We investigated among different functions, including slope variation, which would be the best to show the relation between lens thickness and age. An available model portraying lens growth could be advantageous in many practical applications. The possibility of differences between sexes in lens thickness growth is also analyzed. METHODS: We evaluated 102 eyes of patients aged between 15 and 84 years: 41 men, 61 women. The biometric measurements were performed with the aid of the OcuScan® (Alcon, USA). RESULTS: Both logarithmic and potential functions provide a good fit for the data (R2 = 0.905 and 0.906, respectively). The results do not show significant differences between men and women in any age range, nor when the data of the whole sample are considered (p = 0.29). CONCLUSIONS: The best fits for the data are both logarithmic and double logarithmic functions. According to this model, lens growth continues throughout life, but after 50 years, age-related thickness variations are lower than statistical variability. No differences were found between the sexes.

Neurofibroma esporádico sobre unión esofagogástrica. A propósito de un caso / Sporadic neurofibroma on the esophagogastric junction. A case report

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Clostridium difficile infection in chilean patients submitted to hematopoietic stem cell transplantation

Introduction: Patients submitted to hematopoietic stem cell transplantation have an increased risk of Clostridium difficile infection and multiple risk factors have been identi- fied. Published reports have indicated an incidence from 9% to 30% of transplant patients however to date there is no information about infection in these patients in Chile. Methods: A retrospective analysis was performed of patients who developed C. difficile infection after hematopoietic stem cell transplantations from 2000 to 2013. Statistical analysis used the Statistical Package for the Social Sciences software. Results: Two hundred and fifty patients were studied (mean age: 39 years; range: 17-69), with 147 (59%) receiving allogeneic transplants and 103 (41%) receiving autologous trans- plants. One hundred and ninety-two (77%) patients had diarrhea, with 25 (10%) cases of C. difficile infection being confirmed. Twenty infected patients had undergone allogeneic trans- plants, of which ten had acute lymphoblastic leukemia, three had acute myeloid leukemia and seven had other diseases (myelodysplastic syndrome, chronic myeloid leukemia, severe aplastic anemia). In the autologous transplant group, five patients had C. difficile infection; two had multiple myeloma, one had amyloidosis, one had acute myeloid leukemia and one had germinal carcinoma. The overall incidence of C. difficile infection was 4% within the first week, 6.4% in the first month and 10% in one year, with no difference in overall survival between infected and non-infected groups (72.0% vs. 67.6%, respectively; p-value = 0.56). Patients infected after allogeneic transplants had a slower time to neutrophil engraftment compared to non-infected patients (17.5 vs. 14.9 days, respectively; p-value = 0.008). In the autologous transplant group there was no significant difference in the neutrophil engraftment time between infected and non-infected patients (12.5 days vs. 11.8 days, respectively; p-value = 0.71). In the allogeneic transplant group, the median time to acute graft-versus- host disease was similar between the two groups (p-value = 0.08), as was the incidence of grades 1-4 acute graft-versus-host disease (40% vs. 48%; p-value >0.05). Conclusion: The incidence of C. difficile infection after hematopoietic stem cell transplantation was low, with a significant number of cases occurring shortly after transplantation. Allogeneic transplants had a three-time higher risk of infection compared to autologous transplants, but this was not associated with increased mortality, decreased overall survival or higher risk of acute graft-versus-host disease.

Corresponding-pair procedure: a new approach to simulation of dichromatic color perception.

The dichromatic color appearance of a chromatic stimulus T can be described if a stimulus S is found that verifies that a normal observer experiences the same sensation viewing S as a dichromat viewing T. If dichromatic and normal versions of the same color vision model are available, S can be computed by applying the inverse of the normal model to the descriptors of T obtained with the dichromatic model. We give analytical form to this algorithm, which we call the corresponding-pair procedure. The analytical form highlights the requisites that a color vision model must verify for this procedure to be used. To show the capabilities of the method, we apply the algorithm to different color vision models that verify such requisites. This algorithm avoids the need to introduce empirical information alien to the color model used, as was the case with previous methods. The relative simplicity of the procedure and its generality makes the prediction of dichromatic color appearance an additional test of the validity of color vision models.