Role of Zr loading into In2O3 catalysts for the direct conversion of CO2/CO mixtures into light olefins.

The effect of the ZrO2 content on the performance (activity, selectivity, stability) of In2O3-ZrO2 catalyst has been studied on the hydrogenation of CO2/CO mixtures. This effect is a key feature for the viability of using In2O3-ZrO2/SAPO-34 tandem catalysts for the direct conversion of CO2 and syngas into olefins via oxygenates as intermediates. The interest of co-feeding syngas together with CO2 resides in jointly valorizing syngas derived from biomass or wastes (via gasification) and supplying the required H2. The experiments of methanol synthesis and direct synthesis of olefins, with In2O3-ZrO2 and In2O3-ZrO2/SAPO-34 catalysts, respectively, have been carried out under the appropriate conditions for the direct olefins synthesis (400 °C, 30 bar, H2/COX ratio = 3) in an isothermal fixed bed reactor at low space time values (kinetic conditions) to evaluate the behavior and deactivation of the catalysts. The Zr/In ratio of 1/2 favors the conversion of CO2 and COX, attaining good oxygenates selectivity, and prevents the sintering attributable to the over-reduction of the In2O3 (more significant for syngas feeds). The improvement is more remarkable in the direct olefins synthesis, where the thermodynamic equilibrium of methanol formation is displaced, and methanation suppressed (in a greater extent for feeds with high CO content). With the In2O3-ZrO2/SAPO-34 tandem catalysts, the conversion of COx almost 5 folds respect oxygenates synthesis with In2O3-ZrO2 catalyst, meaning the yield of the target products boosts from ∼0.5% of oxygenates to >3% of olefins (selectivity >70%) for mixtures of CO2/COX of 0.5, where an optimum performance has been obtained.

[Growth hormone of dried blood spot for the diagnosis of growth hormone deficiency]. / Hormona de crecimiento en sangre de papel filtro para el diagnóstico de deficiencia de hormona de crecimiento.

INTRODUCTION: The diagnosis of growth hormone deficiency (GHD) is difficult to determine, and could be associated with severe complications, especially in the neonatal period. The stimulation test of growth hormone (GH) secretion is considered the gold standard for diagnosis, but it has methodological complications and is associated with adverse effects. Neonates present physiological increased secretion of GH, representing a diagnostic window. OBJECTIVE: To evaluate if the dried blood spot on filter paper obtained in the neonatal period, as part of a neonatal screening for con genital hypothyroidism and phenylketonuria, allows differentiating patients with GHD from those who do not have it. PATIENTS AND METHOD: Study of cases and controls by measuring the GH concen tration in dried blood spot on filter paper obtained in the neonatal period, comparing controls with GHD with cases with discarded deficiency. The sample was extracted from the filter paper, obtaining two 0.125 inch discs per each patient from the center of the blood spot on the paper, for a highly sen sitive ELISA assay for human GH based on the use of polyclonal antibodies against 22 kDa recom binant human GH. RESULTS: Seven cases of GHD and ten controls were obtained. The median GH concentration of the dried blood spot in the cases is 2.0 ng/ml (Interquartile range 3.6 ng/ml) and 2.05 ng/ml (Interquartile range 2.0 ng/ml) in the controls, Mann-Whitney U test 30.5 (p = 0.68). The two cases with multiple pituitary-hormone deficiency (MPHD) present concentrations lower than 1 ng/ml. CONCLUSION: The dried blood spot sample did not differentiate GHD patients from control cases, although MPHD cases present much lower concentrations compared to isolated growth hor mone deficiency (IGHD).

Prevalence of diabetes mellitus and impaired glucose metabolism in the adult population of the Basque Country, Spain.

AIMS: To assess the prevalence of diabetes mellitus and impaired glucose metabolism in the Basque Country and their relationship with cardiovascular risk factors. METHODS: A population-based, cross-sectional, cluster sampling design study was carried out in an adult (≥18 years) Basque population. A total of 847 participants completed a questionnaire on personal and family medical history and lifestyle. Anthropometric variables and blood pressure were measured and biochemical analysis and an oral glucose tolerance test (75 g) were also performed. RESULTS: The total prevalence of diabetes was 10.6% (95% CI 8.65-12.95). Among them 6.3% (95% CI 4.79-8.22) had previously been diagnosed and 4.3% (95% CI 3.04-5.92) were not aware that they had diabetes. Impaired glucose tolerance was present in 7.2% (95% CI 5.53-9.15) and impaired fasting glucose in 3.8% (95% CI 2.64-5.37) of the population. In total, 21.6% of the population had some type of glucose metabolism disturbance, with a higher rate among men (28.3 vs 16.3%; P<0.001) and with the rate increasing with age. Risk factors independently associated with the development of diabetes were: male sex [odds ratio 4.58 (95% CI 2.34-8.97)]; abdominal obesity [odds ratio 2.80 (95% CI 1.47-5.36)]; high triglyceride levels [odds ratio 2.46 (95% CI 1.26-4.81)]; hypertension [odds ratio 2.40 (95% CI 1.16-4.96)]; family history of diabetes [odds ratio 2.30 (95% CI 1.25-4.24)]; high LDL cholesterol levels [odds ratio 1.83 (95% CI 1.01-3.31)] and older age [odds ratio 1.08 (95% CI 1.05-1.10)]. CONCLUSIONS: The prevalence of diabetes in the Basque Country was lower than in Spain and was independently associated with family history of diabetes and with cardiovascular risk factors such as abdominal obesity, hypertension, high LDL cholesterol levels and high triglyceride levels, which were also observed in those with prediabetes.

Leuprolide acetate gonadotrophin response patterns during female puberty.

OBJECTIVE: To assess normative data and the usefulness of spontaneous and LHRH analogue-stimulated serum LH and FSH levels measured by immunoradiometric assays (IRMA) in the evaluation of normal puberty. DESIGN: Prospective. Healthy girls in Tanner I and Tanner II from the local community were invited to participate (n = 47). METHODS: A leuprolide acetate test (500 mcg/m(2); sc) was performed. LH and FSH levels were determined using IRMA. Tanner II girls were assessed every 6 months until Tanner V. Girls who progressed from Tanner II to Tanner III in the next 6 months were called Tanner II-2; otherwise, they were called Tanner II-1. RESULTS: The prepubertal upper limit (CI 95%) was 0.49 IU/l for basal LH and 5.1 IU/l for stimulated LH. Taking into account these LH cut-off limits, 72.2% and 66.7% of Tanner II-1 and 41.6% and 41.7% of Tanner II-2 subjects presented overlapping values for basal and stimulated LH, respectively, as compared with the Tanner I group. The cut-offs for basal and stimulated LH to predict progression from Tanner II to Tanner III in the next 6 months were a basal LH level > or =0.49 IU/l (Sensitivity = 0.58; 1-Specificity = 0.33) and a poststimulated LH level > or =4.75 IU/l (Sensitivity = 0.67; 1-Specificity = 0.44). CONCLUSION: According to an IRMA, the basal and leuprolide acetate gonadotrophin response patterns during the beginning stages of puberty overlapped between Tanner I and Tanner II, and the cut-offs of basal and stimulated LH levels to predict progress from Tanner II to Tanner III had low sensitivities for the following 6 months.

Evaluation of the influence of main groundwater ions on arsenic removal by limestones through column experiments.

The influence of common groundwater major ions on arsenic (As) retention by native limestones was studied through column experiments. Columns were packed with rock particles (0.5-1.41 mm) and fed with solutions containing As, and chloride (Cl), sulfate, bicarbonate or fluoride (F) in concentrations similar to those measured in one of the most As-rich wells of Mexico. Besides, other solutions were also treated containing multiples or submultiples of those anion concentrations. Physico-chemical parameters, As, and each anion concentrations were determined weekly along 4 months. After the end of the experiments rocks collected from the top of the columns were analyzed by XRF, XRD, and SEM-WDS. Concentrations of As decreased from 1.2 mg/L to values below the Mexican drinking water standard (0.025 mg/L), since the first week in the solutions containing F or Cl keeping low values afterwards, indicating that they do not interfere with As removal. However, although As strongly decreased in the solutions containing sulfate since the first week, it started to increase from the 12th week in the highest concentrated solution. Bicarbonate was the anion affecting most As retention, since, after its decrease below 0.025 mg/L in the 2nd week for both solutions (30 mg/L and 300 mg/L), it started to increase since the 7th week in the most concentrated one, but maintained a low concentration in the least concentrated solution. Saturation index calculations and XRD analyses did not evidence the formation of As minerals. However, SEM elemental maps and XRF analyses showed the presence of As on the rocks after the treatments. Results indicate that As may be retained by sorption. Sulfate and bicarbonate compete with As for sorption sites. Results showed that native limestones are an option for treating As polluted water. Experiments also indicated that bicarbonate and sulfate may interfere with As removal depending on their concentrations.

Axonal elongation into peripheral nervous system "bridges" after central nervous system injury in adult rats.

The origin, termination, and length of axonal growth after focal central nervous system injury was examined in adult rats by means of a new experimental model. When peripheral nerve segments were used as "bridges" between the medulla and spinal cord, axons from neurons at both these levels grew approximately 30 millimeters. The regenerative potential of these central neurons seems to be expressed when the central nervous system glial environment is changed to that of the peripheral nervous system.

Electrophysiologic responses in hamster superior colliculus evoked by regenerating retinal axons.

Autologous peripheral nerve grafts were used to permit and direct the regrowth of retinal ganglion cell axons from the eye to the ipsilateral superior colliculus of adult hamsters in which the optic nerves had been transected within the orbit. Extracellular recordings in the superior colliculus 15 to 18 weeks after graft insertion revealed excitatory and inhibitory postsynaptic responses to visual stimulation. The finding of light-induced responses in neurons in the superficial layers of the superior colliculus close to the graft indicates that axons regenerating from axotomized retinal ganglion cells can establish electrophysiologically functional synapses with neurons in the superior colliculus of these adult mammals.

Expression of the growth-associated protein GAP-43 in adult rat retinal ganglion cells following axon injury.

We have studied the expression of the growth-associated protein GAP-43 after injury to the axons of adult rat retinal ganglion cells (CNS neurons that do not normally regenerate injured axons). Both the biosynthetic labeling of GAP-43 and the GAP-43 immunoreactivity of the retina increased after axotomy, but only when the injury was within 3 mm of the eye. These results suggest the following conclusions: First, axon injury is sufficient to alter GAP-43 expression in CNS neurons, even in the absence of regeneration. Second, mechanisms that regulate GAP-43 expression are sensitive to the length of uninterrupted axon remaining after injury. Finally, the conditions that favor increased GAP-43 are similar to those that favor regrowth of injured CNS axons into grafts of peripheral nerve, suggesting that GAP-43 induction is accompanied by an increased potential of injured CNS neurons to regenerate.

[Optical coherence tomography and macular phototoxicity]. / OCT y fototoxicidad macular.

CASE REPORT: Ocular examinations and optical coherence tomography (OCT) were performed in three patients with retinal phototoxicity lesions. Fluorescein angiography depicted a window defect. OCT exhibited hyporeflectivity at the outer foveal retina and fragmentation of the inner reflective layers, corresponding to the junction between the inner and outer photoreceptor segments. DISCUSSION: Retinal damage after light exposure has a rapid onset and shows different patterns in OCT examination. OCT findings suggest that decreased visual acuity may be associated with full-thickness photoreceptors and retinal pigment epithelium (RPE) involvement. OCT is a useful tool for objective assessment of retinal pathology in phototoxicity cases where fundus changes may be minimal or absent.

Testicular adrenal rest tumors and Leydig and Sertoli cell function in boys with classical congenital adrenal hyperplasia.

CONTEXT: Infertility observed in adult males with congenital adrenal hyperplasia (CAH) has been associated with testicular adrenal rest tumors (TART) that may originate during childhood. OBJECTIVE: Our objective was to describe the prevalence of TART and Sertoli and Leydig cell function in a group of boys aged 2-10 yr with CAH and to compare prevalence with that of a control group. DESIGN: From August 2005 to January 2007, 19 patients with classical CAH (CAH group) were referred from seven endocrinology centers. METHODS: We studied 19 subjects in the CAH group and, as a control group, 13 boys from the community that did not have testicular diseases. A complete physical exam was performed. High-resolution ultrasound was used to determine TART prevalence. Inhibin B and anti-Müllerian hormone were used as Sertoli cell markers. The ratio between basal testosterone levels and testosterone levels 72 h after beta-human chorionic gonadotropin (5000 U/m2) treatment [(T72- T0)/T0] was used to evaluate Leydig cell response. RESULTS: CAH and control groups were comparable in chronological age (5.9 vs. 5.6 yr; P = 0.67) and bone age/chronological age ratio (1.09 vs. 1.03; P = 0.09). TART prevalence was four of 19 (21%) in the CAH group. Lower values for inhibin B (49.2. vs. 65.2 pg/ml; P = 0.018), anti-Müllerian hormone (70.1 vs. 94.2 ng/ml; P = 0.002), and (T72- T0)/T0 (5.6 vs. 13.6; P < 0.01) were observed in the CAH group. CONCLUSION: TART in prepubertal males with classic CAH could be found during childhood. We also report differences in markers of gonadal function in a subgroup of patients, especially in those with inadequate control.

Trophic factors.

The various neurotrophic factors influence a wide range of cell functions in the developing, mature and injured nervous system. Recent studies have provided valuable insights on the receptors that mediate these effects and on the intracellular events that follow the binding of the ligand. Although growth factors were known to be expressed by non-neuronal cells in the targets and pathways of neuronal projections, it is now clear that the neurons themselves can also be a source of these molecules. A better understanding of the mechanisms of action of trophic factors on the survival and differentiation of neurons, coupled with advances in methods for the delivery of these molecules to the nervous system have provided an impetus for exploring their use as aids to the protection and regeneration of the injured nervous system.

Treatment of central precocious puberty with triptorelin 11.25 mg depot formulation.

A new triptorelin 11.25 mg long depot formulation is now available for the treatment of central precocious puberty (CPP). The aim of our study was to evaluate the efficacy of triptorelin 11.25 mg administered every 90 days to suppress gonadotropin and sex steroid secretion and pubertal signs in children with CPP during 2 years of treatment. Inclusion criteria were clinical pubertal development before the age of 8 years in girls or 9 years in boys, advanced bone age and a pubertal LH response (peak >5 mIU/ml) to GnRH. We studied 20 patients (19 girls and 1 boy), with a median age at entry into the study of 7.5 +/- 0.2 years for girls, and 9 years for the boy. The basal and GnRH-stimulated serum levels of LH and FSH decreased significantly from baseline to 3 months of therapy (p <0.0001). All patients had a GnRH-stimulated peak below 3 mIU/ml between 6 and 24 months of treatment. The pituitary-gonadal axis recovered adequately after discontinuation of therapy. These results suggest that 3-month depot triptorelin is a satisfactory alternative for the therapy of children with CPP. The longer interval between injections may increase acceptability and compliance with treatment.

Clinical and genetic characterization of congenital hyperinsulinism in Spain.

CONTEXT: Congenital hyperinsulinism (CHI) is a clinically and genetically heterogeneous disease characterized by severe hypoglycemia caused by inappropriate insulin secretion by pancreatic ß-cells. OBJECTIVE: To characterize clinically and genetically CHI patients in Spain. DESIGN AND METHODS: We included 50 patients with CHI from Spain. Clinical information was provided by the referring clinicians. Mutational analysis was carried out for KCNJ11, ABCC8, and GCK genes. The GLUD1, HNF4A, HNF1A, UCP2, and HADH genes were sequenced depending on the clinical phenotype. RESULTS: We identified the genetic etiology in 28 of the 50 CHI patients tested: 21 had a mutation in KATP channel genes (42%), three in GLUD1 (6%), and four in GCK (8%). Most mutations were found in ABCC8 (20/50). Half of these patients (10/20) were homozygous or compound heterozygous, with nine being unresponsive to diazoxide treatment. The other half had heterozygous mutations in ABCC8, six of them being unresponsive to diazoxide treatment and four being responsive to diazoxide treatment. We identified 22 different mutations in the KATP channel genes, of which ten were novel. Notably, patients with ABCC8 mutations were diagnosed earlier, with lower blood glucose levels and required higher doses of diazoxide than those without a genetic diagnosis. CONCLUSIONS: Genetic analysis revealed mutations in 56% of the CHI patients. ABCC8 mutations are the most frequent cause of CHI in Spain. We found ten novel mutations in the KATP channel genes. The genetic diagnosis is more likely to be achieved in patients with onset within the first week of life and in those who fail to respond to diazoxide treatment.

Plasma hepatocyte growth factor is a prognostic factor in patients with acute myeloid leukemia but not in patients with myelodysplastic syndrome.

Hepatocyte growth factor (HGF) is a potent angiogenic factor. The aim of our study was to evaluate plasma HGF levels and their prognostic significance in patients with newly diagnosed acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The sandwich enzyme immunoassay technique was used to quantify HGF in stored samples obtained before treatment from patients with AML (59 patients) and MDS (42 patients) treated at The University of Texas MD Anderson Cancer Center. HGF levels were significantly higher in patients with AML or MDS than in healthy individuals (P < 0.0001). Higher HGF levels in both AML and MDS correlated significantly with white blood cell (P = 0.000001 for both groups) and monocyte counts (P = 0.0004 and 0.003, respectively), and with poor performance status (P = 0.03 and 0.001, respectively). Using Cox proportional hazard model and HGF levels as a continuous variable, plasma levels of HGF correlated with shorter survival of AML (P = 0.001), but not MDS (P = 0.34) patients. No significant correlation was observed between HGF levels and complete remission rate or duration. In the multivariate analysis HGF retained its significance as prognostic factor in AML (P = 0.02), along with age (P = 0.0005).

[Asymptomatic vasoproliferative retinal tumor]. / Tumor vasoproliferativo de la retina asintomático.

PURPOSE/METHOD: A case of vasoproliferative retinal tumor is described. The main differential diagnoses must be excluded and the therapeutic possibilities defined. RESULTS/CONCLUSIONS: Vasoproliferative retinal tumors are infrequent benign retinal lesions of gliovascular composition. The differential diagnoses needing consideration are a retinal hemangioma associated with von Hippel-Lindau disease, an amelanotic choroidal melanoma and an ocular metastasis from a tumor elsewhere. Treatment must be performed in those cases where the sight is threatened.

Test of Memory Malingering (TOMM): Normative data for the Latin American Spanish speaking adult population.

BACKGROUND: The Test of Memory Malingering (TOMM) is an instrument used to assess purposeful embellishment or fabrication of memory difficulties for personal gain. Although the TOMM can be use in non-English speaking cultures, it has not been validated in Spanish-speaking Central and South American contexts. OBJECTIVE: To generate normative data on TOMM across 7 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. METHOD: The sample consisted of 2,266 healthy adults who were recruited from Argentina, Bolivia, Chile, Mexico, Paraguay, Peru, and Puerto Rico. Each subject was administered the TOMM as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. RESULTS: t-tests did not show significant differences in TOMM performance between men and women in any countries of the TOMM Trial 1 or 2. As a result, gender-adjusted norms were not generated. CONCLUSIONS: The results from this study will have a large impact on the practice of neuropsychology in Latin America, as this is the first normative multicenter study to create norms for the TOMM in this global region.

Symbol Digit Modalities Test: Normative data for the Latin American Spanish speaking adult population.

OBJECTIVE: To generate normative data on the Symbol Digit Modalities Test (SDMT) across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. METHOD: The sample consisted of 3,977 healthy adults who were recruited from Argentina, Bolivia, Chile, Cuba, El Salvador, Guatemala, Honduras, Mexico, Paraguay, Peru, and, Puerto Rico. Each subject was administered the SDMT as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. RESULTS: The final multiple linear regression models explained 29-56% of the variance in SDMT scores. Although there were gender differences on the SDMT in Mexico, Honduras, Paraguay, and Guatemala, none of the four countries had an effect size greater than 0.3. As a result, gender-adjusted norms were not generated. CONCLUSIONS: This is the first normative multicenter study conducted in Latin America to create norms for the SDMT; this study will have an impact on the future practice of neuropsychology throughout the global region.

Brief Test of Attention: Normative data for the Latin American Spanish speaking adult population.

OBJECTIVE: To generate normative data on the Brief Test of Attention (BTA) across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. METHOD: The sample consisted of 3,977 healthy adults who were recruited from Mexico, Argentina, Peru, Paraguay, Honduras, Chile, Cuba, Puerto Rico, Guatemala, El Salvador, and Bolivia. Each subject was administered the BTA as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. RESULTS: The final multiple linear regression models explained between 11-41% of the variance in BTA scores. Although men had higher scores on the BTA in Honduras, there were no other significant gender differences, and this one effect size was small. As a result, gender-adjusted norms were not generated. CONCLUSIONS: This is the first normative multicenter study conducted in Latin America to create norms for the BTA; this study will have an impact on the future practice of neuropsychology throughout Latin America.

Trail Making Test: Normative data for the Latin American Spanish speaking adult population.

OBJECTIVE: To generate normative data on the Trail Making Test (TMT) across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. METHOD: The sample consisted of 3,977 healthy adults who were recruited from Mexico, Argentina, Peru, Paraguay, Honduras, Chile, Cuba, Puerto Rico, Guatemala, El Salvador, and Bolivia. Each subject was administered the TMT as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. RESULTS: The final multiple linear regression models for the TMT-A explained 23- 50% of the variance, and the final multiple linear models for the TMT-B explained 22- 49% of the variance. Although there were gender differences on the TMT in Mexico, Peru, Paraguay, and Honduras, only Honduras had an effect size greater than 0.3. As a result, gender-adjusted norms were generated for the Trail Making Test-A, but not B, in this country. CONCLUSIONS: The present study is the first to create norms for the TMT in Latin America. As a result, this study will have important implications for the practice of neuropsychology in the future.

Hopkins Verbal Learning Test- Revised: Normative data for the Latin American Spanish speaking adult population.

OBJECTIVE: To generate normative data on the Hopkins Verbal Learning Test- Revised (HVLT-R) across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. METHOD: The sample consisted of 3,977 healthy adults who were recruited from Argentina, Bolivia, Chile, Cuba, El Salvador, Guatemala, Honduras, Mexico, Paraguay, Peru, and, Puerto Rico. Each subject was administered the HVLT-R as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. RESULTS: The final multiple linear regression models explained 17- 45% of the variance in HVLT-R scores. Although t-tests showed significant differences between men and women in Guatemala on the HVLT-R, it was a small effect size. As a result, gender-adjusted norms were not generated. CONCLUSIONS: The results from this study will have a substantial impact on the practice of neuropsychology in Latin America, as this is the first normative multicenter study to develop norms for the HVLT-R in this region.