Phylogenetic diversity and North Andean block conservation.

Background: The Northern Andean Block (NAB) harbors high biodiversity; therefore, it is one of the most important areas in the Neotropics. Nevertheless, the settlement of several human populations has triggered the rapid transformation of ecosystems, leading to the extinction or endangerment of many species. Methods: Because phylogenetic diversity indices quantify the historical distinctness between species, they are adequate tools for evaluating priority conservation areas. We reconstructed 93 phylogenies encompassing 1,252 species and, utilizing their occurrence data sourced from the Global Biodiversity Information Facility, computed the Average Taxonomic Distinctness Index (AvTD) for each grid cell with a spatial resolution of 0.25° within the NAB. The index values for each grid cell were categorized into quantiles, and grid cells displaying values within the upper quantile (Q5) were identified as the most significant in terms of phylogenetic diversity. We also calculated the contribution of endemic species to overall phylogenetic diversity within the NAB, specifically focusing on areas preserved within protected areas. Results: The NAB Andean region exhibited the highest AvTD, with high AvTD values observed in the middle and southern areas of Cordilleras. Endemic species made a relatively modest contribution to the overall phylogenetic diversity of the NAB, accounting for only 1.2% of the total. Despite their relatively small geographical footprints, protected areas within the NAB have emerged as crucial repositories of biodiversity, encompassing 40% of the total phylogenetic diversity in the region. Discussion: Although the NAB Andean region has been identified as the most crucial area in terms of AvTD, some regions in the Amazonian Piedemonte and Pacific lowlands have high AvTD levels. Interestingly, some protected areas have been found to harbor higher AvTDs than expected, given their smaller size. Although the delimitation of new PAs and species richness have been the primary factors driving the expansion of PAs, it is also essential to consider the evolutionary information of species to conserve all aspects of biodiversity, or at least cover most of them. Therefore, using phylogenetic diversity measures and the results of this study can contribute to expanding the PA network and improving the connectivity between PAs. This approach will help conserve different aspects of biodiversity and preserve evolutionary relationships between species.

Diseño y Validación de una Aplicación Móvil, para el Diagnóstico de Anemia en Pre-Escolares. Estudio de Precisión Diagnóstica / Design and Validation of a Mobile Application for the Diagnosis of Anemia in Preschoolers. Diagnostic Accuracy Study

La anemia afecta a miles de niños. Para el diagnóstico se cuantifica la hemoglobina (Hb); técnica que no se encuentra al alcance de toda la población. Contar con un instrumento validado de fácil aplicación, puede ayudar al diagnóstico. El objetivo de este estudio fue validar una aplicación móvil (APP) para diagnosticar anemia en niños de 2 a 5 años, aplicable por padres o tutores. Estudio de validación de escalas. Mediante búsqueda bibliografía se recopilaron ítems y dominios relacionados con anemia en niños. Una vez reducidos, se construyó un cuestionario para pilotaje, con tres hematólogos pediatras. El resultado de este fue posteriormente validado por 22 expertos mediante aplicación de escalas tipo Likert. Los ítems validados, se contrastaron con la Hb de niños de 267 niños de 2 a 5 años de los andes ecuatorianos (2.560 msnm). Se determinó asociación de los ítems con Hb y con los resultados obtenidos y se construyó la APP. 14 ítems fueron analizados. Todos ellos puntuaron sobre la mediana de la distribución (35,5 puntos) y fueron valorados por, al menos el 50 % de los expertos. Se seleccionaron palidez palmar, astenia y sueño en horas no habituales. Todos mostraron asociación significativa con anemia (p<0,05), y fueron aplicados como preguntas a padres o tutores y contrastados con el valor de Hb. Sensibilidad y especificidad para palidez fue: 85,1 % y 85,0 %; astenia: 72,3 % y 87,7 %; sueño en horas no habituales: 68,1 % y 87,7 %; palidez más astenia o sueño: 95,7 % y 74,6 %; y debilidad más sueño: 92,5 % y 76,8 %. Se desarrolló y validó una APP para diagnóstico de anemia en niños de 2 a 5 años aplicable por padres o tutores.

SUMMARY: Anemia affects thousands of children, and to reach a diagnosis, hemoglobin (Hb) is quantified. This technique however, is not always accessible to the general population. Therefore, the availability of a validated instrument can be useful in the diagnosis. The aim of this study was to validate a mobile application (APP), to diagnose anemia in children from 2 to 5 years old, applicable by parents or guardians. Scale validation study. Through a bibliographic search, items and domains related to anemia in children were collected. Once reduced, a pilot questionnaire was constructed with three pediatric hematologists. The result was later validated by 22 experts through the application of the Likert-type scales. The validated items were contrasted with the Hb of children of 267 children from 2 to 5 years of age from the Ecuadorian Andes (2,560 meters above sea level). The association of the items with Hb and with the results obtained was determined, and the APP was constructed. 14 items were analyzed. All of them scored above the median of the distribution (35.5 points) and were valued by at least 50 % of the experts. Palmar pallor, asthenia, and sleep at unusual hours were selected. All showed a significant association with anemia (p<0.05) and were applied as questions to parents or guardians and contrasted with the Hb value. Sensitivity and specificity for pallor was: 85.1 % and 85.0 %; asthenia: 72.3 % and 87.7 %; sleep at unusual hours: 68.1 % and 87.7 %; paleness plus fatigue or sleepiness: 95.7 % and 74.6 %; and weakness plus sleep: 92.5 % and 76.8 %. An APP for the diagnosis of anemia in children from 2 to 5 years old applicable by parents or guardians was developed and validated.

Systematics and phylogeography of bats of the genus Rhynchonycteris (Chiroptera: Emballonuridae): Integrating molecular phylogenetics, ecological niche modeling and morphometric data.

Rhynchonycteris is a monotypic genus of Embalonurid bats, whose geographic distribution extends from southern Mexico to tropical regions of the South American continent, including Trinidad and Tobago. Although species that have a wide geographic distribution are frequently revealed to be polytypic, to date, no study has evaluated the taxonomic status of populations of Rhynchonycteris naso. Thus, the aim of this study is to address the patterns of phylogeographic structure and taxonomic subdivision of R. naso using molecular phylogenetics, morphometric data and ecological niche modeling. Phylogenetic results recovered using the genes COI, Cytb, Chd1, Dby, and Usp9x, supported the monophyly of the genus Rhynchonycteris, in addition, a deep phylogeographic structure was revealed by the mitochondrial gene COI for the populations of Belize and Panama in comparison to those of South America. The PCA, and the linear morphometry indicated an apparent differentiation between the cis-Andean and trans-Andean populations. Furthermore, according to the skull morphology, at least two morphotypes were identified. Ecological niche modeling projections in the present have shown that the Andean cordillera acts as a climatic barrier between these two populations, with the depression of Yaracuy (Northwest Venezuela) being the only putative climatically suitable path that could communicate these two populations. On the other hand, projections for the last glacial maximum showed a drastic decrease in climatically suitable areas for the species, suggesting that cycles of lower temperatures played an important role in the separation of these populations.

Nanohybrid of Thymol and 2D Simonkolleite Enhances Inhibition of Bacterial Growth, Biofilm Formation, and Free Radicals.

Due to the current concerns against opportunistic pathogens and the challenge of antimicrobial resistance worldwide, alternatives to control pathogen growth are required. In this sense, this work offers a new nanohybrid composed of zinc-layered hydroxide salt (Simonkolleite) and thymol for preventing bacterial growth. Materials were characterized with XRD diffraction, FTIR and UV-Vis spectra, SEM microscopy, and dynamic light scattering. It was confirmed that the Simonkolleite structure was obtained, and thymol was adsorbed on the hydroxide in a web-like manner, with a concentration of 0.863 mg thymol/mg of ZnLHS. Absorption kinetics was described with non-linear models, and a pseudo-second-order equation was the best fit. The antibacterial test was conducted against Escherichia coli O157:H7 and Staphylococcus aureus strains, producing inhibition halos of 21 and 24 mm, respectively, with a 10 mg/mL solution of thymol-ZnLHS. Moreover, biofilm formation of Pseudomonas aeruginosa inhibition was tested, with over 90% inhibition. Nanohybrids exhibited antioxidant activity with ABTS and DPPH evaluations, confirming the presence of the biomolecule in the inorganic matrix. These results can be used to develop a thymol protection vehicle for applications in food, pharmaceutics, odontology, or biomedical industries.

Role of lactic acid bacteria and yeasts in sourdough fermentation during breadmaking: Evaluation of postbiotic-like components and health benefits.

Sourdough (SD) fermentation is a traditional biotechnological process used to improve the properties of baked goods. Nowadays, SD fermentation is studied for its potential health effects due to the presence of postbiotic-like components, which refer to a group of inanimate microorganisms and/or their components that confer health benefits on the host. Some postbiotic-like components reported in SD are non-viable microorganisms, short-chain fatty acids, bacteriocins, biosurfactants, secreted proteins/peptides, amino acids, flavonoids, exopolysaccharides, and other molecules. Temperature, pH, fermentation time, and the composition of lactic acid bacteria and yeasts in SD can impact the nutritional and sensory properties of bread and the postbiotic-like effect. Many in vivo studies in humans have associated the consumption of SD bread with higher satiety, lower glycemic responses, increased postprandial concentrations of short-chain fatty acids, and improvement in the symptoms of metabolic or gastrointestinal-related diseases. This review highlights the role of bacteria and yeasts used for SD, the formation of postbiotic-like components affected by SD fermentation and the baking process, and the implications of functional SD bread intake for human health. There are few studies characterizing the stability and properties of postbiotic-like components after the baking process. Therefore, further research is necessary to develop SD bread with postbiotic-related health benefits.

Species Surface Distribution and Surface Tension of Aqueous Solutions of MIBC and NaCl Using Molecular Dynamics Simulations.

Methyl isobutyl carbinol (MIBC) is a high-performance surfactant with unusual interfacial properties much appreciated in industrial applications, particularly in mineral flotation. In this study, the structure of air-liquid interfaces of aqueous solutions of MIBC-NaCl is determined by using molecular dynamics simulations employing polarizable and nonpolarizable force fields. Density profiles at the interfaces and surface tension for a wide range of MIBC concentrations reveal the key role of polarizability in determining the surface solvation of Cl- ions and the expulsion of non-polarizable Na+ ions from the interface to the liquid bulk, in agreement with spectroscopic experiments. The orientation of MIBC molecules at the water liquid-vapor interface changes as the concentration of MIBC increases, from parallel to the interface to perpendicular, leading to a well-packed monolayer. Surface tension curves of fresh water and aqueous NaCl solutions in the presence of MIBC intersect at a reproducible surfactant concentration for a wide range of salt concentrations. The simulation results for a 1 M NaCl aqueous solution with polarizable water and ions closely capture the MIBC concentration at the intercept. The increase in surface tension of the aqueous MIBC/NaCl mixture below the concentration of MIBC at the intersection seems to originate in a disturbance of the interfacial hydrogen bonding structure of the surface liquid water caused by Na+ ions acting at a distance and not by its presence on the interface.

Estimating the Shear Resistance of Flocculated Kaolin Aggregates: Effect of Flocculation Time, Flocculant Dose, and Water Quality.

The resistance of kaolin aggregates to shearing in water clarification and recovery operations is a critical input in designing thickener feed wells. A recently formulated but already available criterion is used to determine the shear strength of flocculated kaolin aggregates. The flocculant is a high molecular weight anionic polyelectrolyte. The resistance of the aggregates is evaluated as a function of flocculation time, flocculant dosage, and water quality. The determination is based on a standardized experimental method. First, the time evolution of the average size of kaolin flocs is measured when aggregates are exposed to incremental shear rates from a predetermined base value. Then, the results are fitted to a pseudo-first-order model that allows deriving a characteristic value of the shear rate of rupture associated with the upper limit of the strength of the aggregates. In seawater, at a given dose of flocculant, the strength of the aggregates increases with time up to a maximum; however, at longer times, the resistance decreases until it settles at a stable value corresponding to stable aggregates in size and structure. A higher flocculant dosage leads to stronger aggregates due to more bridges between particles and polymers, leading to a more intricate and resistant particle network. In industrial water with very low salt content, the resistance of the kaolin aggregates is higher than in seawater for the same dose of flocculant. The salt weakens the resistance of the aggregates and works against the efficiency of the flocculant. The study should be of practical interest to concentration plants that use seawater in their operations.

Biogeographic evidence supports the Old Amazon hypothesis for the formation of the Amazon fluvial system.

The Amazon has high biodiversity, which has been attributed to different geological events such as the formation of rivers. The Old and Young Amazon hypotheses have been proposed regarding the date of the formation of the Amazon basin. Different studies of historical biogeography support the Young Amazon model, however, most studies use secondary calibrations or are performed at the population level, preventing evaluation of a possible older formation of the Amazon basin. Here, we evaluated the fit of molecular phylogenetic and biogeographic data to previous models regarding the age of formation of the Amazon fluvial system. We reconstructed time-calibrated molecular phylogenies through Bayesian inference for six taxa belonging to Amphibia, Aves, Insecta and Mammalia, using both, nuclear and mitochondrial DNA sequence data and fossils as calibration points, and explored priors for both data sources. We detected the most plausible vicariant barriers for each phylogeny and performed an ancestral reconstruction analysis using areas bounded by major Amazonian rivers, and therefore, evaluated the effect of different dispersal rates over time based on geological and biogeographical information. The majority of the genes analyzed fit a relaxed clock model. The log normal distribution fits better and leads to more precise age estimations than the exponential distribution. The data suggested that the first dispersals to the Amazon basin occurred to Western Amazonia from 16.2-10.4 Ma, and the taxa covered most of the areas of the Amazon basin between 12.2-6.2 Ma. Additionally, regardless of the method, we obtained evidence for two rivers: Tocantins and Madeira, acting as vicariant barriers. Given the molecular and biogeographical analyses, we found that some taxa were fitted to the "Old Amazon" model.

Mechanistic study of the biosynthesis of R-phenylacetylcarbinol by acetohydroxyacid synthase enzyme using hybrid quantum mechanics/molecular mechanics simulations.

The biosynthesis of R-phenylacetylcarbinol (R-PAC) by the acetohydroxy acid synthase, (AHAS) is addressed by molecular dynamics simulations (MD), hybrid quantum mechanics/molecular mechanics (QM/MM), and QM/MM free energy calculations. The results show the reaction starts with the nucleophilic attack of the C2α atom of the HEThDP intermediate on the Cß atom of the carbonyl group of benzaldehyde substrate via the formation of a transition state (TS1) with the HEThDP intermediate under 4'-aminopyrimidium (APH+) form. The calculated activation free energy for this step is 17.4 kcal mol-1 at 27 °C. From this point, the reaction continues with the abstraction of Hß atom of the HEThDP intermediate by the Oß atom of benzaldehyde to form the intermediate I. The reaction is completed with the cleavage of the bond C2α-C2 to form the product R-PAC and to regenerate the ylide intermediate under the APH+ form, allowing in this way to reinitiate to the catalytic cycle once more. The calculated activation barrier for this last step is 15.9 kcal mol-1 at 27 °C.

Mechanistic study of the biosynthesis of R-phenylcarbinol by acetohydroxyacid synthase enzyme using hybrid quantum mechanics/molecular mechanics simulations.

The biosynthesis of R-phenylacetylcarbinol (R-PAC) by the acetohydroxy acid synthase, (AHAS) is addressed by molecular dynamics simulations (MD), hybrid quantum mechanics/molecular mechanics (QM/MM), and QM/MM free energy calculations. The results show the reaction starts with the nucleophilic attack of the C2α atom of the HEThDP intermediate on the Cß atom of the carbonyl group of benzaldehyde substrate via the formation of a transition state (TS1) with the HEThDP intermediate under 4'-aminopyrimidium (APH+) form. The calculated activation free energy for this step is 17.4kcal mol-1 at 27 °C. From this point, the reaction continues with the abstraction of Hß atom of the HEThDP intermediate by the Oß atom of benzaldehyde to form the intermediate I. The reaction is completed with the cleavage of the bond C2α-C2 to form the product R-PAC and to regenerate the ylide intermediate under the APH+ form, allowing in this way to reinitiate to the catalytic cycle once more. The calculated activation barrier for this last step is 15.9kcal mol-1 at 27 °C.

Sarcoptic mange in wild quichua porcupines (Coendou quichua Thomas, 1899) in Colombia.

The Quichua porcupine (Coendou quichua) is a neotropical rodent with uncertain taxonomic and conservation status. Two Quichua porcupines with severe hyperkeratosis and alopecia were found in the Magdalena River Basin of Colombia. Sarcoptes scabiei, the mite causing mange, a disease carried mainly by domestic animals, was confirmed via parasitological and molecular methods. This is the first report of mange in neotropical porcupines to date. The population-level impact of mange in Coendou spp., related mammals and predators in Colombia might represent a threat and needs further investigation.

Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula.

In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2-7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula.

Nature of crossing vessels in patients with radiographically normal ureteropelvic junctions: prevalence and anatomic characteristics.

OBJECTIVE: To evaluate the prevalence and characteristics of crossing vessels in asymptomatic patients with a radiographically normal ureteropelvic junction. MATERIALS AND METHODS: We retrospectively reviewed the computed tomography angiography images of 601 patients who were evaluated for possible living organ donation at the University of Minnesota from 2005 to 2008. One patient had asymptomatic hydronephrosis and was excluded from the analysis. The prevalence and characteristics of crossing vessels at the ureteropelvic junction were determined, including vessel location, origin, size, distance from the ureteropelvic junction, and vessel type (artery or vein). RESULTS: The prevalence of crossing vessels at the radiographically normal ureteropelvic junction was 22.7%. A total of 163 crossing vessels were present in 136 patients; 60.1% were left-sided and 39.9% were right-sided. Arteries accounted for 81.0% of the crossing vessels and veins for 19.0%. Accessory lower pole renal vessels originating from the great vessels constituted 59.5% of the crossing vessels. The location of the crossing vessel relative to the ureteropelvic junction varied and included anterior (25.8%), anterolateral (36.8%), medial (14.6%), anteromedial (2.5%), lateral (12.9%), and posterior (7.4%). The mean diameter and mean distance of the crossing vessel from the ureteropelvic junction was 3.3 mm and 1.8 mm, respectively. CONCLUSION: The prevalence of crossing vessels in asymptomatic, healthy patients with a radiographically normal ureteropelvic junction was 22.7%, lower than that seen in association with ureteropelvic junction obstruction. The location of the crossing vessels varied about the ureteropelvic junction, and no location was consistently free of traversing vessels.

Patient-centered medical therapy for nephrolithiasis.

OBJECTIVE: To elucidate the effect of a patient-centered combined nutritional and medical therapy approach on stone disease management, guided by 24-hour urinary stone risk. MATERIALS AND METHODS: We retrospectively analyzed the records of patients treated at our multidisciplinary stone clinic from July 2007 to February 2009. Included were adult stone formers who presented with severe urinary abnormalities or whose urinary parameters failed to improve with dietary changes. Urinary risk factors for stone disease were evaluated before and after intervention with 24-hour urine collections. Hypercalciuria was treated with hydrochlorothiazide/indapamide, hypocitraturia with potassium/calcium citrate, and hyperuricosuria with allopurinol. The primary end point was the effect of combined dietary and medical intervention on levels of urinary metabolites. Statistical comparisons of postintervention urine collection values with baseline values were performed using a paired t test. Two-tailed P <.05 was considered statistically significant. RESULTS: Data for 137 patients with a mean follow-up of 14.39 months were analyzed. Mean age was 47.2 years, and the male-to-female ratio was 1.04. Hypocitraturia was detected in 70 patients (51%), hypercalciuria in 49 (37%) and hyperuricosuria in 18 (13%). A significant improvement was found in 67% of patients with hypocitraturia (urinary citrate levels: 380.28 to 663.96 mg/d; P <.0001), in 82% of patients with hypercalciuria (urinary calcium levels: 337.4 to 183.6 mg/d; P <.0001), and in 72% of patients with hyperuricosuria (urinary citric acid level: 927 to 600 mg/d; P <.0001). CONCLUSION: Medical management of stone disease instituted based on individual risk factors impacts subsequent urinary stone risk, supporting its use for stone disease when patients do not respond to lifestyle and dietary changes.

Computer-assisted study on the reaction between pyruvate and ylide in the pathway leading to lactyl-ThDP.

In this study the formation of the lactyl-thiamin diphosphate intermediate (L-ThDP) is addressed using density functional theory calculations at X3LYP/6-31++G(d,p) level of theory. The study includes potential energy surface scans, transition state search, and intrinsic reaction coordinate calculations. Reactivity is analyzed in terms of Fukui functions. The results allow to conclude that the reaction leading to the formation of L-ThDP occurs via a concerted mechanism, and during the nucleophilic attack on the pyruvate molecule, the ylide is in its AP form. The calculated activation barrier for the reaction is 19.2 kcal/mol, in agreement with the experimental reported value.

Correlation between stress and kidney stone disease.

BACKGROUND AND PURPOSE: Prevalence of kidney stone disease is increasing worldwide, and several factors may be involved. We aimed to establish a correlation between stress and kidney stones. PATIENTS AND METHODS: We prospectively evaluated 200 patients with a diagnosis of kidney stone disease having them self-respond to a validated questionnaire to measure stress (Perceived Stress Scale-10 [PSS-10]). Stone-related characteristics and potential stressing factors were assessed. Variables that were significant on the univariate analysis were used to construct a model that was able to explain the variability in PSS-10 score in our patients. RESULTS: Mean PSS-10 score was 15.3 ± 1.1. Female sex (P=0.014), occurrence of death or serious illness of a family member or close friend within the last 6 months of the interview (P=0.044), occurrence of other psychological trauma (P<0.0001) all proved to be significant factors. Stone-related aspects associated with stress were presence of symptoms at the time of the interview (P=0.012) and passage of two or more stones per year (P=0.022). We were able to construct a model that explains 34% of the variability of the PSS-10 between subjects. Employment status was the only significant variable, but sex, age, and presence of symptoms at the time of questionnaire administration had to be kept in to achieve a model that explains the largest variability. CONCLUSIONS: Passage of two or more stones per year and presence of symptoms proved to be factors related to elevated stress in patients with a diagnosis of kidney stone disease. Female sex, age, and unemployment may also contribute to a stressed state in this population.

Omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid in the management of hypercalciuric stone formers.

OBJECTIVE: To investigate the use of fish oil in the dietary management of hypercalciuric stone formers. Prostaglandins have been linked to urinary calcium excretion, suggesting a role for omega-3 fatty acids in the treatment of hypercalciuric urolithiasis. METHODS: We retrospectively studied a cohort of patients treated at our stone clinics from July 2007 to February 2009. Patients' urinary risk factors for stone disease were evaluated with pre- and post-intervention 24-hour urine collections. All patients received empiric dietary recommendations for intake of fluids, sodium, protein, and citric juices. All subjects with hypercalciuria (urinary calcium>250 mg/d for males or >200 mg/d for females) on at least two 24-hour urine collections were counseled to supplement their diet with fish oil (1200 mg/d). RESULTS: Twenty-nine patients were followed for 9.86±8.96 months. The mean age was 43.38±13.78 years. Urinary calcium levels decreased in 52% of patients, with 24% converting to normocalciuria. The average urinary calcium (mg/d) decreased significantly from baseline (329.27±96.23 to 247.47±84.53, P<.0001). Urinary oxalate excretion decreased in 34% of patients. The average urinary oxalate (mg/d) decreased significantly from baseline (45.40±9.90 to 32.9±8.21, P=.0004). Urinary citrate (mg/d) increased in 62% of subjects from baseline (731.67±279.09 to 940.22±437.54, P=.0005). Calcium oxalate supersaturation decreased in 38% of the subjects significantly from baseline (9.73±4.48 to 3.68±1.76, P=.001). CONCLUSION: Omega-3 fatty acids combined with empiric dietary counseling results in a measurable decrease in urinary calcium and oxalate excretion and an increase in urinary citrate in hypercalciuric stone formers.

Screening assay for oxidative stress in a feline astrocyte cell line, G355-5.

An often-suggested mechanism of virus induced neuronal damage is oxidative stress. Astrocytes have an important role in controlling oxidative stress of the Central Nervous System (CNS). Astrocytes help maintain a homeostatic environment for neurons as well as protecting neurons from Reactive Oxygen Species (ROS). CM-H2DCFDA is a cell-permeable indicator for the presence of ROS. CM-H(2)DCFDA enters the cell as a non-fluorescent compound, and becomes fluorescent after cellular esterases remove the acetate groups, and the compound is oxidized. The number of cells, measured by flow cytometry, that are found to be green fluorescing is an indication of the number of cells that are in an oxidative state. CM-H(2)DCFDA is susceptible to oxidation by a large number of different ROS. This lack of specificity, regarding which ROS can oxidize CM-H(2)DCFDA, makes this compound a valuable regent for use in the early stages of a pathogenesis investigation, as this assay can be used to screen for an oxidative cellular environment regardless of which oxygen radical or combination of ROS are responsible for the cellular conditions. Once it has been established that ROS are present by oxidation of CM-H(2)DCFDA, then additional experiments can be performed to determine which ROS or combination of ROSs are involved in the particular pathogenesis process. The results of this study demonstrate that with the addition of hydrogen peroxide an increase in CM-H(2)DCFDA fluorescence was detected relative to the saline controls, indicating that this assay is a valuable test for detecting an oxidative environment within G355-5 cells, a feline astrocyte cell line.

A dual-channel flexible ureteroscope: evaluation of deflection, flow, illumination, and optics.

BACKGROUND AND PURPOSE: Despite the evolution and progressive improvements of ureteroscopes, problems related to visibility and maneuverability can still hinder the goals of surgical intervention. We evaluate the attributes of a dual-channel flexible ureteroscope compared with a single-channel device and discuss the implications for expanded techniques afforded by this new technology. MATERIALS AND METHODS: In vitro measurements of active deflection, irrigant flow through the working channel, luminescence, and optical resolution were performed between the single-channel Wolf Viper and the dual-channel Wolf Cobra ureteroscopes. Characteristics were obtained with the working channels both empty and with combinations of a 200 µ holmium aser fiber, 3.0F biopsy forceps, and 1.5F, 2.4F, and 2.8F nitinol basket. Luminescence from each scope was measured using a commercial luminometer. Three blinded physicians rated the optical resolution captured electronically using a standard test image. RESULTS: The single-channel scope has improved upward deflection both empty and with all but the largest single tools, with an improved range of 4 to 15 degrees. The dual-channel scope has superior downward deflection across all comparisons (average increase of 24.5 degrees) and superior upward deflection with large or multiple instruments in the working channel. Baseline flows through each individual-channel of the dual-channel scope were slower than the larger single-channel ureteroscope. Because flow can be provided through a dedicated port in the dual-channel configuration, however, overall flow, depending on instrumentation, can be up to 37 times faster than the single-channel (range 1.5-37×). Optical resolution and luminescence are comparable between the two scopes. CONCLUSION: The dual-channel flexible ureteroscope provides similar deflection characteristics to the current single-channel scope. Deflection and flow characteristics are superior, however, when larger or multiple simultaneous instruments are used in the working channel. These benefits may facilitate the development and implementation of novel endoscopic procedures.

Impact of dietary counseling on urinary stone risk parameters in recurrent stone formers.

OBJECTIVES: The aim of this study was to investigate the current impact of dietary counseling on the risk for urolithiasis. METHODS: A retrospective cohort study of the patients treated in our stone clinics from July 2007 to February 2009 was carried out. Patients' urinary risk factors for stone disease were evaluated with pre- and postintervention 24-hour urine collections. All patients received dietary recommendations from a registered dietician at each visit. RESULTS: One hundred thirty-seven subjects were identified and managed initially with only dietary interventions to address their urinary stone risk parameters. Average follow-up for this group was 15.19 ± 13.7 months. Subjects showed significant changes in urine volume (71.1%, 1.68 ± 0.68 to 2.59 ± 0.80 L/day, p < 0.0001), urine sodium (58.1%, 229.68 ± 72.51 to 144.65 ± 52.70 mmol/day, p < 0.0001), urine calcium (43.8%, 314.33 ± 95.75 to 216.81 ± 80.90 mg/day, p < 0.0001), urinary uric acid (50%, 0.821 ± 0.210 to 0.622 ± 0.128 g/day, p < 0.0001), urinary citrate (50.7%, 583.19 ± 330.86 to 797.36 ± 412.31, p < 0.0001), and urine oxalate (55.5%, 46.28 ± 10.31 to 32.56 ± 9.02 mg/day, p < 0.0001). The supersaturation for calcium oxalate also decreased significantly from baseline (9.34-5.03, p < 0.0001). CONCLUSION: Urolithiasis is a multifactorial disease requiring a multidisciplinary approach. Our results support the use of dietary counseling by a registered dietician in the management of urolithiasis.