Effect of phytate on hypercalciuria secondary to bone resorption in patients with urinary stones: pilot study.

The objective is to evaluate the effect of phytate supplements on calciuria in patients with urinary stones and elevated bone resorption. The secondary objective is to analyze the therapeutic effect of phytate based on measurements of serum markers of bone resorption. This is a controlled randomized study included patients according to predefined inclusion and exclusion criteria, and randomized them into two groups. Patients in the phytate group received a 380 mg capsule of calcium-magnesium InsP6 (Salvat Laboratories®) every 24 h for 3 months and patients in the control group received no treatment. All included patients were male or female, 18-65 years old, had hypercalciuria (> 250 mg/24 h), had a ß-Crosslaps level greater than 0.4 ng/mL, and had bone densitometry results indicative of osteopenia or osteoporosis in the femur and/or spine. At study onset, calciuria was 321 ± 52 mg/24 h in the phytate group and 305 ± 57 mg/24 h in the control group (p > 0.05). At 3 months, calciuria was significantly lower in the phytate group than the control group (226 ± 45 mg/24 h vs. 304 ± 58 mg/24 h, p < 0.05). At study onset, the mean ß-CrossLaps level was 1.25 ± 0.72 ng/mL in the phytate group and 0.57 ± 0.13 ng/mL in the control group (p < 0.05). However, at 3 months, the ß-CrossLaps level was significantly lower in the phytate group than in the control group (0.57 ± 0.13 ng/mL vs. 0.77 ± 0.42 ng/mL, p < 0.05). Phytate reduced calciuria in patients with hypercalciuria secondary to bone resorption. The ß-CrossLaps assay was effective for evaluating the efficacy of phytate on hypercalciuria during follow-up.

Numerical Modeling of Head Losses in Different Types of Well Screens.

Quantifying total well loss through well screens has been traditionally undertaken through experimentally based empirical equations or equations derived for water flow through (circular) orifices. Advances in computer capacity enables incorporation of CFD formulations at millimeter scale, coupling Darcy flow and Reynolds Averaged Navier Stokes (RANS) to better understand and quantify processes related to well loss for different screen types. This study provides a methodology of quantifying well screen head loss using numerical models, coupling Darcy flow (aquifer and filter/gravel pack) with turbulent flow (in-well and through screen) at a sub-millimeter scale. Results are used to compare performance of four different types of well screens (Louver, slotted, bridge and wire wrap) and their overall impact and contribution to total well head loss for different slot apertures, pumping rates and hydraulic conductivity of the filter/gravel pack providing a new empirical formulation to quantify screen head loss.

Processes explaining the origin and evolution of groundwater composition in the Andean Precordillera and Altiplano of the Tarapacá Region of northern Chile.

In the arid area of northern Chile, groundwater resources in the Andean formations are essential for native populations, ecological services, mining, and other human activities. Validated conceptual hydrogeological models are required for current and future water and land management. This work aims to explain the processes controlling the origin and distribution of recharge and groundwater composition in the Andean Precordillera and Altiplano of the Tarapacá Region of northern Chile, using major solutes in spring, river, and well water, and the stable and radioactive isotopes of water oxygen, hydrogen, and dissolved inorganic carbon. The waters are mainly of the Na-Ca-SO4 type. Processes controlling the chemical evolution of waters are atmospheric dust contribution, evapo-concentration, and enhanced volcanic rock weathering, as well as halite dissolution in some locations. The isotopic composition of Precordillera eastern flank water samples follows an evaporation line, while those in the western flank, in the Altiplano, follow a line that is parallel to the local meteoric line, suggesting unsaturated zone evaporation processes of infiltrated rainfall. δ13CDIC contents (-2 to -27‰) indicate mixing processes, volcanic CO2 in the Altiplano, and calcite dissolution in some sectors. In the western depression, the only recharge is due to water infiltration in creek channels. In the highland areas, 5-25% of precipitation produces recharge. The estimated groundwater renewal time in the Precordillera was 3-14 kyr. The piezometric elevation in the Precordillera due to low-permeability intrusive rocks and local recharge prevents the east-west groundwater transfer from the Altiplano to the western depression and explains why the volcanic CO2 in the Altiplano basins is not observed on the western flank. These results provide new insights for the evolution of water quality in volcanic aquifers in arid environments and provide considerations for estimating groundwater residence times using radiocarbon in areas influenced by volcanic CO2.

Prevalence of distal renal tubular acidosis in patients with calcium phosphate stones.

INTRODUCTION AND PURPOSE: Distal renal tubular acidosis (DRTA) is a metabolic disorder that associates urolithiasis and urinary pH > 6. The prevalence of DRTA in patients with calcium phosphate stones is not well known. The objective is to determine the prevalence of DRTA in patients with calcium phosphate stones and urinary pH above 6 based on the furosemide test. METHODS: A total of 54 patients with calcium phosphate stones and urinary pH above 6.0 were submitted to the furosemide test. The association of DRTA with age, sex, type of stone, stone recurrence, stone bilaterality, 24-h urine biochemistry, and adverse effects of the furosemide test were examined. RESULTS: The furosemide test indicated that 19 of 54 patients (35.2%) had DRTA. The sex ratio was similar in the two groups (p < 0.776). The DRTA group was significantly younger (p < 0.001), and had a higher prevalence of bilateral stones (p < 0.001), a higher prevalence of recurrent stones (p < 0.04), a lower plasma potassium level (p < 0.001), a higher urinary Ca level (p ≤ 0.05), and a lower urinary citrate level (p < 0.001). None of the patients reported adverse effects from the furosemide test. CONCLUSIONS: There was a high prevalence of DTRA in patients with urinary pH above 6 and calcium phosphate stones. Young age, bilateral stones, stone recurrence, hypercalciuria, hypocitraturia, and plasma hypokalemia were associated with DRTA. None of the patients reported adverse effects of the furosemide test.

Estimates of Horizontal Groundwater Flow Velocities in Boreholes.

Currently, monitoring tools can be deployed in observation boreholes to better assess groundwater flow, flux of dissolved contaminants and their mass discharge in an aquifer. The relationship between horizontal water velocity in observation boreholes and Darcy fluxes in the surrounding aquifer has been studied for natural flow conditions (i.e., no pumping). Interpretation of measurements taken with dilution tests, the colloidal borescope, the Heat Pulse Flowmeter, and other techniques require the conversion of observed borehole velocity u to aquifer Darcy flux q∞ . This conversion is typically done through a proportionality factor α = u/q∞ . In experimental studies as well as in theoretical developments, reported values of α vary almost three orders of magnitude (from 0.5 to 10). This large variability in reported values of α could be explained by: (1) unclear distinction between Darcy flux and water seepage velocity, (2) unclear definition of water velocity in the borehole, (3) effects of well screen and the presence of the measurement device itself on the observable velocities, and (4) hydraulic conditions in the borehole annulus. We address (1), (2) from a conceptual/theoretical perspective, and (3) by means of numerical simulations. We show that issue (1) in low porosity aquifers can yield to order-of-magnitude discrepancies in estimates of q∞ ; (2) may result in discrepancies of up to 50%, and (3) can cause differences up to 20% of water velocity in the borehole void space compared to the theoretical case of an open borehole.

[Efficacy and safety of bilateral RIRS for renal lithiasis.] / Eficacia y seguridad de la RIRS bilateral para el tratamiento de litiasis renal.

OBJECTIVES: We present our experience in single-stage bilateral retrograde intrarenal surgery (RIRS), analyzing the stone free rate (SFR), surgical time, hospital stay, pre- and post procedure creatinine, stone composition and complications. METHODS: Between April 2012 and February 2016, 24 RIRS were carried out in 12 patients with bilateral renal stones. Patients were 9 men and 3 women with a median age of 47.5 (range:55),IMC: 23.59 (range: 12.5). RESULTS: Mean number of stones per renal unit was 2.7 (range: 12), mostly located in the renal pelvis (40%), with an average size of 16.08±8.06 mm and an average stone burden of 258.54±242.59 mm². The SFR at 3 months was 83.33%. Average operation time was 75 minutes and median hospital stay was 2 days. Three complications were recorded (25%), all of them minor (Clavien I-II). No major complications were recorded (Clavien III-V). CONCLUSIONS: Single-stage bilateral RIRS is a safe and effective tool for the treatment of patients with bilateral renal stones.

Eficacia y seguridad de la RIRS bilateral para el tratamiento de litiasis renal / Efficacy and safety of bilateral RIRS for renal lithiasis

OBJETIVOS: Presentar nuestra experiencia en cirugía intrarrenal retrógrada (RIRS) bilateral en un mismo acto quirúrgico, analizando la tasa de pacientes libres de litiasis (SFR), el tiempo quirúrgico, la estancia hospitalaria, las complicaciones, las diferencias entre la creatinina pre- y postoperatoria y la composición de los cálculos. MÉTODOS: Entre abril de 2012 y febrero de 2016 se han realizado 24 RIRS en 12 pacientes con litiasis renal bilateral, entre los que se encuentran 9 hombres y 3 mujeres, con mediana de edad de 47,5 (rango: 55), IMC: 23.59 (rango: 12,5). RESULTADOS: El número de cálculos por unidad renal es de 2,7 (rango: 12), localizados preferentemente en la pelvis renal (40%), con un tamaño medio de 16,08±8,06 mm y una carga litiásica media de 258,54±242,59 mm2. El SFR a los 3 meses es de 83,33%. El tiempo operatorio medio ha sido 75 minutos y la estancia hospitalaria mediana de 2 días. Se han registrado 3 complicaciones (25%), todas ellas complicaciones menores (Clavien I-II). No se han registrado complicaciones mayores (Clavien III-V). CONCLUSIONES: La RIRS bilateral en un mismo acto quirúrgico es una herramienta eficaz y segura para el tratamiento de pacientes con litiasis renales bilaterales

OBJECTIVES: We present our experience in single-stage bilateral retrograde intrarenal surgery (RIRS), analyzing the stone free rate (SFR), surgical time, hospital stay, pre- and post procedure creatinine, stone composition and complications. METHODS: Between April 2012 and February 2016, 24 RIRS were carried out in 12 patients with bilateral renal stones. Patients were 9 men and 3 women with a median age of 47.5 (range: 55), IMC: 23.59 (range: 12.5). RESULTS: Mean number of stones per renal unit was 2.7 (range: 12), mostly located in the renal pelvis (40%), with an average size of 16.08±8.06 mm and an average stone burden of 258.54±242.59 mm2. The SFR at 3 months was 83.33%. Average operation time was 75 minutes and median hospital stay was 2 days. Three complications were recorded (25%), all of them minor (Clavien I-II). No major complications were recorded (Clavien III-V). CONCLUSIONS: Single-stage bilateral RIRS is a safe and effective tool for the treatment of patients with bilateral renal stones

Hairy/Enhancer-of-Split MEGANE and Proneural MASH1 Factors Cooperate Synergistically in Midbrain GABAergic Neurogenesis.

GABAergic neurons are the primary inhibitory cell type in the mature brain and their dysfunction is associated with important neurological conditions like schizophrenia and anxiety. We aimed to discover the underlying mechanisms for dorsal/ventral midbrain GABAergic neurogenesis. Previous work by us and others has provided crucial insights into the key function of Mgn and Mash1 genes in determining GABAergic neurotransmitter fate. Induction of dorsal midbrain GABAergic neurons does not take place at any time during development in either of the single mutant mice. However, GABAergic neurons in the ventral midbrain remained unchanged. Thus, the similarities in MB-GABAergic phenotype observed in the Mgn and Mash1 single mutants suggest the existence of other factors that take over the function of MGN and MASH1 in the ventral midbrain or the existence of different molecular mechanisms. We show that this process essentially depends on heterodimers and homodimers formed by MGN and MASH1 and deciphered the in vivo relevance of the interaction by phenotypic analysis of Mgn/Mash1 double knockout and compound mice. Furthermore, the combination of gain- and loss-of-function experiments in the developing midbrain showed co-operative roles for Mgn and Mash1 genes in determining GABAergic identity. Transcription factors belonging to the Enhancer-of-split-related and proneural families have long been believed to counterpart each other's function. This work uncovers a synergistic cooperation between these two families, and provides a novel paradigm for how these two families cooperate for the acquisition of MB-GABAergic neuronal identity. Understanding their molecular mechanisms is essential for cell therapy strategies to amend GABAergic deficits.

Ascl1 and Helt act combinatorially to specify thalamic neuronal identity by repressing Dlxs activation.

The mammalian thalamus is an essential diencephalic derivative that plays unique roles in processing and relaying sensory and motor information to and from the cerebral cortex. The profile of transcription factors and lineage tracing experiments revealed a spatiotemporal relationship between diencephalic progenitor domains and discrete differentiated neurons contributing to thalamic nuclei. However, the precise molecular mechanisms by which heterogeneous thalamic neurons become specified and assemble into distinct thalamic nuclei are still poorly understood. Here, we show that a combinatorial interaction between the bHLH transcription factors Ascl1 and Helt is required for acquiring thalamic progenitor identity. Surprisingly, in the combined absence of Ascl1 and Helt, rostral thalamic progenitors (TH-R) adopt a molecular profile of a more rostral diencephalic derivative, the prethalamus. Furthermore, we show that the prethalamic factors Dlxs upregulated by Ascl1/Helt deficiency play unique roles in regulating thalamic progenitor specification, and that derepression of Dlx2 and Dlx5 suppress generation of TH-R neurons. Taken together, our results suggest a model whereby the combined activity of two distinct bHLH factors plays a key role in the development of discrete classes of thalamic interneurons.

Subcortical visual shell nuclei targeted by ipRGCs develop from a Sox14+-GABAergic progenitor and require Sox14 to regulate daily activity rhythms.

Intrinsically photosensitive retinal ganglion cells (ipRGCs) and their nuclear targets in the subcortical visual shell (SVS) are components of the non-image-forming visual system, which regulates important physiological processes, including photoentrainment of the circadian rhythm. While ipRGCs have been the subject of much recent research, less is known about their central targets and how they develop to support specific behavioral functions. We describe Sox14 as a marker to follow the ontogeny of the SVS and find that the complex forms from two narrow stripes of Dlx2-negative GABAergic progenitors in the early diencephalon through sequential waves of tangential migration. We characterize the requirement for Sox14 to orchestrate the correct distribution of neurons among the different nuclei of the network and describe how Sox14 expression is required both to ensure robustness in circadian entrainment and for masking of motor activity.

Pallial origin of basal forebrain cholinergic neurons in the nucleus basalis of Meynert and horizontal limb of the diagonal band nucleus.

The majority of the cortical cholinergic innervation implicated in attention and memory originates in the nucleus basalis of Meynert and in the horizontal limb of the diagonal band nucleus of the basal prosencephalon. Functional alterations in this system give rise to neuropsychiatric disorders as well as to the cognitive alterations described in Parkinson and Alzheimer's diseases. Despite the functional importance of these basal forebrain cholinergic neurons very little is known about their origin and development. Previous studies suggest that they originate in the medial ganglionic eminence of the telencephalic subpallium; however, our results identified Tbr1-expressing, reelin-positive neurons migrating from the ventral pallium to the subpallium that differentiate into cholinergic neurons in the basal forebrain nuclei projecting to the cortex. Experiments with Tbr1 knockout mice, which lack ventropallial structures, confirmed the pallial origin of cholinergic neurons in Meynert and horizontal diagonal band nuclei. Also, we demonstrate that Fgf8 signaling in the telencephalic midline attracts these neurons from the pallium to follow a tangential migratory route towards the basal forebrain.

Transient expression of Mnb/Dyrk1a couples cell cycle exit and differentiation of neuronal precursors by inducing p27KIP1 expression and suppressing NOTCH signaling.

The decision of a neural precursor to stop dividing and begin its terminal differentiation at the correct place, and at the right time, is a crucial step in the generation of cell diversity in the nervous system. Here, we show that the Down's syndrome candidate gene (Mnb/Dyrk1a) is transiently expressed in prospective neurons of vertebrate CNS neuroepithelia. The gain of function (GoF) of Mnb/Dyrk1a induced proliferation arrest. Conversely, its loss of function (LoF) caused over proliferation and cell death. We found that MNB/DYRK1A is both necessary and sufficient to upregulate, at transcriptional level, the expression of the cyclin-dependent kinase inhibitor p27(KIP1) in the embryonic chick spinal cord and mouse telencephalon, supporting a regulatory role for MNB/DYRK1A in cell cycle exit of vertebrate CNS neurons. All these actions required the kinase activity of MNB/DYRK1A. We also observed that MNB/DYRK1A is co-expressed with the NOTCH ligand Delta1 in single neuronal precursors. Furthermore, we found that MNB/DYRK1A suppressed NOTCH signaling, counteracted the pro-proliferative action of the NOTCH intracellular domain (NICD), stimulated Delta1 expression and was required for the neuronal differentiation induced by the decrease in NOTCH signaling. Nevertheless, although Mnb/Dyrk1a GoF led to extensive withdrawal of neuronal precursors from the cell cycle, it was insufficient to elicit their differentiation. Remarkably, a transient (ON/OFF) Mnb/Dyrk1a GoF efficiently induced neuronal differentiation. We propose that the transient expression of MNB/DYRK1A in neuronal precursors acts as a binary switch, coupling the end of proliferation and the initiation of neuronal differentiation by upregulating p27KIP1 expression and suppressing NOTCH signaling.

Gata2 is a tissue-specific post-mitotic selector gene for midbrain GABAergic neurons.

Midbrain GABAergic neurons control several aspects of behavior, but regulation of their development and diversity is poorly understood. Here, we further refine the midbrain regions active in GABAergic neurogenesis and show their correlation with the expression of the transcription factor Gata2. Using tissue-specific inactivation and ectopic expression, we show that Gata2 regulates GABAergic neuron development in the mouse midbrain, but not in rhombomere 1, where it is needed in the serotonergic lineage. Without Gata2, all the precursors in the embryonic midbrain fail to activate GABAergic neuron-specific gene expression and instead switch to a glutamatergic phenotype. Surprisingly, this fate switch is also observed throughout the neonatal midbrain, except for the GABAergic neurons located in the ventral dopaminergic nuclei, suggesting a distinct developmental pathway for these neurons. These studies identify Gata2 as an essential post-mitotic selector gene of the GABAergic neurotransmitter identity and demonstrate developmental heterogeneity of GABAergic neurons in the midbrain.

Megane/Heslike is required for normal GABAergic differentiation in the mouse superior colliculus.

The mouse Mgn protein (Helt) is structurally related to the neurogenic Drosophila hairy and Enhancer of split [h/E(spl)] proteins, but its unique structural properties distinguish it from other members of the family. Mgn expression shows a spatiotemporal correlation with GABAergic markers in several brain regions. We report here that homozygous Mgn-null mice die between the second and the fifth postnatal week of age, and show a complete depletion of Gad65 and Gad67 expression in the superior colliculus and a reduction in the inferior colliculus. Other brain regions, as well as other neural systems, are not affected. The progenitor GABAergic cells appear to be generated in right numbers but fail to become GABAergic neurons. The phenotype of the mice is consistent with reduced GABAergic activity. Thus, our in vivo study provides evidence that Mgn is the key regulator of GABAergic neurons, controlling their specification in the dorsal midbrain. Another conclusion from our results is that the function of Mgn shows a previously unrecognized role for h/E(spl)-related transcription factors in the dorsal midbrain GABAergic cell differentiation. Vertebrate h/E(spl)-related genes can no longer be regarded solely as a factors that confer generic neurogenic properties, but as key components for the subtype-neuronal identity in the mammalian CNS.

Molecular characterization, structure and developmental expression of Megane bHLH factor.

We report here the full-length sequence identification, molecular characterization, detailed demarcation expression analysis relevant to morphological marker genes and mapping of a bHLH transcription gene, referred to as Megane (Mgn). Mgn protein is structurally related to the neurogenic Drosophila hairy and Enhancer of split (h/E(spl)) proteins. The unique structural properties of Mgn factor in several characteristic residues define the gene as related to h/E(spl), but distinguish it from previously identified mammalian members of the family. Mgn is a single copy gene on mouse chromosome 8 and encodes a 27kDa protein that functions in the nucleus. First expression of Mgn is detected at mouse embryonic day 9.5 within the most rostral part of the cephalic flexure of the developing midbrain. Later, Mgn expression extends into other alar areas of the midbrain and forebrain, developmentally controlled in a regional specific pattern.

mPet-1, a mouse ETS-domain transcription factor, is expressed in central serotonergic neurons.

Here we describe the expression pattern of a previously unknown mouse gene mPet-1. The isolated cDNA codes for an ETS-domain transcription factor of 237 amino acids in length, which is localized to the nucleus. mPet-1 is a member of the winged helix transcription factor gene family like its rat homologue Pet-1 and the human homologue FEV. The start ATG of mPet-1 and the size of the predicted protein are identical to the human FEV. The mPet-1 protein is clearly smaller since it lacks the first 103 N-terminal amino acids of rat Pet-1. mPet- 1 is expressed in central serotonergic (5-hydroxytryptaminergic) neurons located in the mes-/metencephalic raphe nuclei from E11 on until adulthood. In these regions mPet-1 expression co-localizes precisely with the serotonin transporter (Sert),which it initially precedes. Interestingly, mPet-1 was not found in neurons transiently expressing Sert.