Ultrathin space charge layer in hematite photoelectrodes: A theoretical investigation.

The space charge layer in hematite photoelectrodes has been analyzed by means of Poisson-Boltzmann equations, the Stern model, and density functional theory, in view of its application for photoelectrochemical water oxidation. The width of the space charge layer can be smaller than ∼10 Å under experimental conditions. In this regime, a substantial part of the potential drop takes place in the Helmholtz layer, leading to important corrections to the Mott-Schottky behavior of the space charge layer capacitance. These results shed light on an unexpected regime of high photoelectrocatalytic efficiency, different from the classical picture of the electrochemical interface of a semiconducting photocatalyst, which is also amenable to direct study by quantum-mechanical atomistic simulations. Density functional theory has been used to calculate the band bending (BB) in the space charge layer in atomistic models of pristine stoichiometric and hydroxylated surfaces. These surface terminations display BBs of 0.14 and 0.49 eV, respectively, with an increasing width of the space charge layer, however still in the sub-nanometer regime. This work shows that, at high doping, the width of the space charge layer of a hematite photoelectrode can become comparable with interatomic distances.

[Tropical pyomyositis of the iliacus, obturator internus, piriformis and psoas major muscles in an immunocompetent patient with claudication]. / Piomiositis tropical del músculo ilíaco, obturador interno, piriforme y psoas mayor en un paciente inmunocompetente con claudicación.

INTRODUCTION: Pyomyositis is a term that denotes pyogenic infection usually primary skeletal muscle, associated with hematogenous dispersion due to transient bacteremia, or penetrating trauma, usually forming abscesses. Classically described frequently in tropical areas and predominantly affecting the lower limb musculature, however, in recent decades it has increasingly been associated with areas of temperate climates and relatively more frequently in immunosuppressed patients, being the patients under 30 years the most affected. CLINICAL CASE: Male of 15 years without relevant medical history. The patient had no history of trauma, falls, surgical interventions, infections or any other systemic condition. He came because of a clinical picture of 7 days of evolution characterized by pain referred to the groin and left iliac crest area associated with claudication and hyperthermia not quantified, which yielded partially to NSAIDs and paracetamol, but without achieving improvement so it is taken emergency by relatives. CONCLUSIONS: It is necessary to bear in mind this pathology when performing the differential diagnostic approach of a patient presenting with pain and functional limitation of some joint associated with data suggestive of an infectious or inflammatory process.

INTRODUCCIÓN: La piomiositis es un término que denota infección piógena por lo general primaria de músculo esquelético. Clásicamente descrita de manera frecuente en zonas tropicales y en pacientes inmunocomprometidos; sin embargo, en las últimas décadas se observa cada vez más en zonas de climas templados y con relativa mayor frecuencia en pacientes inmunocompetentes, siendo el grupo etario más afectado el de menores de 30 años. CASO CLÍNICO: Masculino de 15 años sin antecedentes médicos de relevancia. Acude por presentar cuadro clínico de siete días de evolución caracterizado por dolor referido en ingle y zona de la cresta ilíaca izquierda asociado a claudicación e hipertermia no cuantificada, que cedían parcialmente a AINES y paracetamol, pero sin lograr mejoría, por lo que es llevado a urgencias por familiares. CONCLUSIONES: Es necesario tener en mente esta patología al momento de realizar el abordaje diagnóstico diferencial de un paciente que se presenta con dolor y limitación funcional de alguna articulación asociada a datos sugestivos de un proceso infeccioso o inflamatorio.

Antibody-Mediated Rejection Treatment With Bortezomib in Renal Transplant Recipients: A Single-Center 24-Month Follow-up Case Report.

INTRODUCTION: Antibody-mediated rejection (AMR) is related to a poor prognosis in graft survival, with 27% to 40% of patients experiencing graft loss within the first year. The mechanism of damage in AMR is mediated by donor-specific antibodies (DSA). No standard treatment for AMR exists, and conventional management includes high doses of steroids, plasmapheresis, intravenous immunoglobulin, and either rituximab or bortezomib. Because of the high cost of these medications and the lack of prospective studies to evaluate their efficacy and safety, their routine use is limited. In the following study, we describe the use of bortezomib for the treatment of AMR in 5 renal transplant recipients with a 24-month follow-up and compare this case with the reviewed literature. MATERIAL AND METHODS: Five cases of AMR diagnosed by biopsy are reported, and these patients received bortezomib at a rate of 1.3 mg/m2 on days 1, 4, 8, and 11; plasmapheresis; and 1 patient received 30 g of intravenous immunoglobulin. RESULTS: All patients received his or her first transplant; 4 were from a cadaveric donor, and 1 patient received thymoglobulin at a standard dose. All patients had maintenance therapy based on cyclosporine, mycophenolate mofetil, and prednisone, with an average baseline creatinine level of 1.3 mg/dL. The average days until rejection event were 952 days. DISCUSSION AND CONCLUSION: AMR treatment with bortezomib was effective, showing stable renal function at 24 months. Patients had adequate tolerance for administration. So far, these results contrast with the literature reviewed, so additional studies and follow-up are required for a new evaluation.

From dusk till dawn: nocturnal and diurnal pollination in the epiphyte Tillandsia heterophylla (Bromeliaceae).

In order to compare the effectiveness of diurnal and nocturnal pollinators, we studied the reproductive biology and pollinators of Tillandsia heterophylla E. Morren, an epiphytic tank bromeliad endemic to southeastern Mexico. Since anthesis in T. heterophylla is predominantly nocturnal but lasts until the following day, we hypothesised that this bromeliad would receive visits from both diurnal and nocturnal visitors, but that nocturnal visitors would be the most effective pollinators, since they arrive first to the receptive flower, and that bats would be the most frequent nocturnal visitors, given the characteristics of the nectar. Flowering of T. heterophylla began in May and lasted until July. The species is fully self-compatible, with an anthesis that lasts for ca. 15-16 h. Mean volume of nectar produced per flower was 82.21 µl, with a mean sugar concentration of 6.33%. The highest volume and concentration of nectar were found at 20:00 h, with a subsequent decline in both to almost zero over the following 12-h period. T. heterophylla has a generalist pollination system, since at least four different morphospecies of visitors pollinate its flowers: bats, moths, hummingbirds and bees. Most of the pollinating visits corresponded to bats and took place in the early evening, when stigma receptivity had already begun; making bats the probable pollinator on most occasions. However, diurnal pollinators may be important as a 'fail-safe' system by which to guarantee the pollination of T. heterophylla.

Endocannabinoids mediate hyposalivation induced by inflammogens in the submandibular glands and hypothalamus.

OBJECTIVE: The aim of this study was to investigate the factors that could participate on salivary glands hypofunction during inflammation and the participation of endocannabinoids in hyposalivation induced by the presence of inflammogens in the submandibular gland (SMG) or in the brain. DESIGN: Salivary secretion was assessed in the presence of inflammogens and/or the cannabinoid receptor antagonist AM251 in the SMG or in the brain of rats. At the end of the experiments, some systemic and glandular inflammatory markers were measured and histopathological analysis was performed. RESULTS: The inhibitory effect observed 1h after lipopolysaccharide (LPS, 50µg/50µl) injection into the SMG (ig) was completely prevented by the injection of AM251 (5µg/50µl) by the same route (P<0.05). The LPS (ig)-induced increase in PGE2 content was not altered by AM251 (ig), while the glandular production of TNFα induced by the endotoxin (P<0.001) was partially blocked by it. Also, LPS injection produced no significant changes in the wet weight of the SMG neither damage to lipid membranes of its cells, nor significant microscopic changes in them, after hispopathological analysis, compared to controls. Finally, TNFα (100ng/5µl) injected intracerebro-ventricularly (icv) inhibited methacholine-induced salivary secretion evaluated 30min after (P<0.01), but the previous injection of AM251 (500ng/5µl, icv) prevented completely that effect. CONCLUSION: We conclude that endocannabinoids mediate the hyposialia induced by inflammogens in the SMG and in the brain. The hypofunction would be due to changes on signalling pathway produced by inflammatory compounds since anatomical changes were not observed.

Utilización de membrana de fascia lata y hueso en polvo liofilizado en cirugía apical: caso clínico / The use of fascia lata membrane and freeze drying bone powder in apical surgery: a clinical case

En un paciente con patología apical y endodoncia previa en la pieza 1.2, se realizó cirugía apical que incluyó el agregado de una membrana biológica reabsorbible de fascia lata entre el colgajo de espesor total y el tejido óseo. En medio de ellos, se colocó hueso en polvo humano liofilizado con el objetivo de proveer una adecuada recuperación del tejido óseo perirradicular. Luego, se efectuó el control clínico y radiográfico del paciente durante 24 meses.

Utilización de membrana de fascia lata y hueso en polvo liofilizado en cirugía apical: caso clínico / The use of fascia lata membrane and freeze drying bone powder in apical surgery: a clinical case

En un paciente con patología apical y endodoncia previa en la pieza 1.2, se realizó cirugía apical que incluyó el agregado de una membrana biológica reabsorbible de fascia lata entre el colgajo de espesor total y el tejido óseo. En medio de ellos, se colocó hueso en polvo humano liofilizado con el objetivo de proveer una adecuada recuperación del tejido óseo perirradicular. Luego, se efectuó el control clínico y radiográfico del paciente durante 24 meses.(AU)

Reconstrucción de una pieza tratada endodónticamente en una sesión con utilización de poste preformado: reporte de caso / Reconstruction of an endodontically treated tooth in a single session with a preformed post

La realización de un anclaje intra-radicular provisorio para iniciar la confección del definitivo en la sesión siguiente aumenta el riesgo de fractura radicular y el riesgo de filtración coronaria de la obturación endodóntica. En el presente trabajo se reporta el caso clínico de un paciente con diagnóstico de pulpitis infiltrativa de la pieza 2.1, al que se le realizó tratamiento endodóntico y posterior anclaje intra-radicular definitivo. El anclaje intra-radicular fue realizado mediante la instalación de un poste orgánico y a continuación se reconstruyó el muñón coronario con resinas compuestas, colocando una corona de acrílico como elemento provisorio, en una misma sesión.

Tratamiento endodóntico obturado con pasta lentamente reabsorbible: seguimiento de un caso a 6 años / Endodontic treatment filled with slowly resorbable paste: a 6-year follow-up case

Reporte de un caso clínico de un tratamiento endodóntico de incisivo central superior con diagnostico de necrosis pulpar y proceso apical preexistente, obturado con pastalentamente reabsorbible. El seguimiento post tratamiento fue realizado mediante controles radiográficos inmediatos y a distancia, en los cuales se evaluó la calidad de la obturación y la reparación de los tejidos dañados.

Long-term outcomes in patients with schizophrenia treated with risperidone long-acting injection or oral antipsychotics in Spain: results from the electronic Schizophrenia Treatment Adherence Registry (e-STAR).

BACKGROUND: The electronic Schizophrenia Treatment Adherence Registry (e-STAR) is a prospective, observational study of patients with schizophrenia designed to evaluate long-term treatment outcomes in routine clinical practice. METHODS: Parameters were assessed at baseline and at 3 month intervals for 2 years in patients initiated on risperidone long-acting injection (RLAI) (n=1345) or a new oral antipsychotic (AP) (n=277; 35.7% and 36.5% on risperidone and olanzapine, respectively) in Spain. Hospitalization prior to therapy was assessed by a retrospective chart review. RESULTS: At 24 months, treatment retention (81.8% for RLAI versus 63.4% for oral APs, p<0.0001) and reduction in Clinical Global Impression Severity scores (-1.14 for RLAI versus -0.94 for APs, p=0.0165) were significantly higher with RLAI. Compared to the pre-switch period, RLAI patients had greater reductions in the number (reduction of 0.37 stays per patient versus 0.2, p<0.05) and days (18.74 versus 13.02, p<0.01) of hospitalizations at 24 months than oral AP patients. CONCLUSIONS: This 2 year, prospective, observational study showed that, compared to oral antipsychotics, RLAI was associated with better treatment retention, greater improvement in clinical symptoms and functioning, and greater reduction in hospital stays and days in hospital in patients with schizophrenia. Improved treatment adherence, increased efficacy and reduced hospitalization with RLAI offer the opportunity of substantial therapeutic improvement in schizophrenia.

2-sec-butyl-4,5-dihydrothiazole is a ligand for mouse urinary protein and rat alpha 2u-globulin: physiological and toxicological relevance.

Mouse urinary protein (MUP) and alpha 2u-globulin are structurally homologous proteins that belong to a superfamily of ligand-binding proteins and represent the major urinary proteins excreted by adult male mice and rats, respectively. Although a variety of xenobiotics bind to alpha 2u-globulin and produce a male rat-specific hyaline droplet nephropathy, no endogenous ligand for this protein has been identified. Despite extensive sequence homology. MUP does not bind to hyaline droplet-inducing agents. While performing experiments with purified MUP, we observed that it presented with a strong, distinctive odor reminiscent of mouse urine. To determine whether this odor was the result of contamination or degradation or was attributed to an endogenous ligand bound to the protein, the protein was subjected to thermal desorption and any released volatile compounds were detected with a gas chromatograph equipped with an external sniff port and mass spectrometer. With this approach, two odorous compounds were detected at the sniff port by a human observer, but only one was present in sufficient mass to allow identification. This compound, which presented with the characteristic odor, was subsequently identified as 2-sec butyl-4,5-dihydrothiazole (DHT) by GC/MS/matrix isolation IR and NMR analyses. The identification of DHT was confirmed by comparing the chromatographic and spectral properties to those of the synthesized authentic compound. In direct contrast, purified urinary alpha 2u-globulin did not present with an obvious odor, and no volatile ligands were detected on this protein. Although DHT is a major endogenous ligand for MUP, it was also found to competitively inhibit the binding of [14C]d-limonene-1,2-epoxide to alpha 2u-globulin with relatively high affinity (Ki = 2.3 microM). When dosed orally to F344 rats, DHT (1 mmol/kg for 3 days) caused the characteristic exacerbation of hyaline droplets in male rat kidneys and increased renal levels of immunoreactive alpha 2u-globulin about threefold over control levels. These results indicate that despite structural homology, MUP and alpha 2u-globulin are distinguished by the presence of a volatile endogenous ligand only on the former, a distinction that may reflect differences in the physiological functions of the two proteins. Furthermore, although DHT can bind to both MUP and alpha 2u-globulin, renal toxicity was only observed in rats, thereby emphasizing the unique toxicological properties of alpha 2u-globulin in the development of hyaline droplet nephropathy.

Synthesis and reactivity of coumarin 3,4-epoxide.

Coumarin is used widely as a fragrance constituent and is administered clinically in the treatment of certain lymphedemas and malignancies. Although toxicity occurs only rarely in humans treated clinically with high-dose coumarin, it is well established that coumarin is hepatotoxic in the rat. This species difference in susceptibility to toxicity reflects the disparate metabolic processes occurring in humans and rodents. In humans, coumarin is converted extensively via cytochrome P450 2A6 to the nontoxic 7-hydroxycoumarin metabolite. In contrast, coumarin 3,4-epoxidation is thought to predominate in rodent species, resulting in the formation of several potentially toxic metabolites. Coumarin epoxide is thought to be highly unstable and has not been isolated synthetically or as a microsomal product. To address this issue, coumarin 3,4-epoxide was synthesized, and its stability and fate have been determined. Coumarin 3,4-epoxide was prepared by reacting coumarin with dimethyldioxirane. The epoxide was stable in organic solvents and survived conditions required for analysis by gas chromotography. Its structure was confirmed via 1H-NMR and gas chromatography-mass spectrometry-infrared spectroscopy (GC-MS-IR). In contrast, coumarin 3,4-epoxide was unstable in aqueous solution, converting within 20 sec to a ring-opened compound. Using GC-MS-IR analysis, the single coumarin 3,4-epoxide product was identified as o-hydroxyphenylacetaldehyde (o-HPA). Although other investigators have suggested that 3-hydroxycoumarin is an intermediate in o-HPA formation from coumarin 3,4-epoxide, we have demonstrated that 3-hydroxycoumarin, incubated in an aqueous system or with liver microsomal proteins, does not form o-HPA. Thus, the results of the present work establish that coumarin 3,4-epoxide can be synthesized and that o-HPA, which has previously been shown to be a prominent coumarin metabolite in rat liver microsomal incubations, is formed directly from coumarin 3,4-epoxide. These results suggest that both coumarin 3,4-epoxide and o-HPA may contribute to the hepatotoxicity of coumarin.

Hyaline droplet nephropathy resulting from exposure to 3,5,5-trimethylhexanoyloxybenzene sulfonate.

Acute oral dosing of 3,5,5-trimethylhexanoyloxybenzene sulfonate (THBS) to adult male and female rats causes a male rat-specific nephrotoxicity manifested as exacerbation of hyaline droplet formation. This chemical is structurally distinct from the volatile hydrocarbons known to cause male rat-specific kidney lesions. Therefore, to classify THBS as a hyaline droplet-inducing agent, experiments were conducted to determine whether [14C]THBS equivalents bound to alpha 2 mu-globulin and caused the protein to accumulate in male rat kidney cortex. Two-dimensional gel electrophoretic separation of male rat kidney proteins indicated that alpha 2u-globulin levels in kidney increased 24 hr after a single oral dose of THBS (500 mg/kg). Furthermore, a sex-dependent retention THBS was noted as there was approximately 10 times more THBS equivalents in male rat kidney than in female rat kidney. Equilibrium dialysis experiments indicated that 40% of THBS equivalents bound reversibly to male rat kidney proteins, whereas no interaction between THBS and female rat kidney proteins was detected. Specific binding of THBS to alpha 2mu-globulin was determined by anion-exchange HPLC after which metabolites in the alpha 2u-globulin fraction were identified by gas chromatography with parallel radioactivity-mass spectrometry and mass spectrometry-matrix isolation Fourier-transform infrared analysis. Four metabolites of THBS were found in this protein fraction, and the major component (approximately 70%) was identified as the cis gamma-lactone of 3,5,5-trimethylhexanoic acid. Experiments were also conducted in mice to determine whether THBS bound to any mouse kidney proteins, particularly mouse urinary protein. The results indicated that there was no interaction between THBS and mouse urinary protein, a protein which shares significant homology with alpha 2u-globulin. These results indicate that THBS treatment exacerbates hyaline droplet formation in male rat kidneys by binding to alpha 2mu-globulin, thereby causing the protein to accumulate in the renal cortex. The interaction between THBS and alpha 2mu-globulin appears to be unique to this male rat-specific protein as THBS does not interact with a very similar protein found in mice.

Design of a gas chromatograph with parallel radioactivity and mass spectrometric detection. Application to the identification of the major metabolite of d-limonene associated with alpha 2u-globulin.

A Perkin Elmer 3920 gas chromatograph, equipped with a versatile inlet system (i.e. an injector/trap), was interfaced to a radioactivity detector and a mass-selective detector (H/P 5970B) to identify 14C-labeled compounds. The use of a pre-trap as a demountable, programmable-temperature injector, in conjunction with the injector/trap, allowed the introduction of 0.5-ml samples of rat kidney cytosol extracts to 0.32 mm I.D. capillary columns. The instrumentation greatly facilitated the identification of the major radiolabeled metabolite of d-limonene associated with the male rat-specific protein alpha 2u-globulin as 1,2-cis-d-limonene oxide.

d-Limonene-induced male rat-specific nephrotoxicity: evaluation of the association between d-limonene and alpha 2u-globulin.

d-Limonene is a naturally occurring monoterpene, which when dosed orally, causes a male rat-specific nephrotoxicity manifested acutely as the exacerbation of protein droplets in proximal tubule cells. Experiments were conducted to examine the retention of [14C]d-limonene in male and female rat kidney, to determine whether d-limonene or one or more of its metabolites associates with the male rat-specific protein, alpha 2u-globulin, and if so, to identify the bound material. The results indicated that, 24 hr after oral administration of 3 mmol d-limonene/kg, the renal concentration of d-limonene equivalents was approximately 2.5 times higher in male rats than in female rats. Equilibrium dialysis in the presence or absence of sodium dodecyl sulfate indicated that approximately 40% of the d-limonene equivalents in male rat kidney associated with proteins in a reversible manner, whereas no significant association was observed between d-limonene equivalents and female rat kidney proteins. Association between d-limonene and male rat kidney proteins was characterized by high-performance gel filtration and reverse-phase chromatography. Gel filtration HPLC indicated that d-limonene in male rat kidney is associated with a protein fraction having a molecular weight of approximately 20,000. Separation of alpha 2u-globulin from other kidney proteins by reverse-phase HPLC indicated that d-limonene associated with a protein present only in male rat kidney which was definitively identified as alpha 2u-globulin by amino acid sequencing. The major metabolite associated with alpha 2u-globulin was d-limonene-1,2-oxide. Parent d-limonene was also identified as a minor component in the alpha 2u-globulin fraction. Thus, d-limonene, and more specifically d-limonene-1,2-oxide, associates with alpha 2u-globulin in a reversible manner in male rat kidney. This interaction may be responsible for excessive accumulation of alpha 2u-globulin in kidneys of male rats exposed to d-limonene.

Niveles sericos de magnesio en ninos con malnutricion proteico-calorica. / Serum magnesium levels in children with protein-calorie malnutrition

Se realizo determinacion serica de magnesio (Mg++) en 79 ninos; 17 casos eran desnutridos con kwashiorkor y 22 eran marasmaticos. Cuarenta ninos eutroficos que sirvieron de control. El valor promedio de Mg++ serico en ninos desnutridos con kwashiorkor fue de 1.08 +/- 0.05 mEq/l mientras que en los marasmaticos fue de 1.83 +/- 0.08 mEq/l. En los eutroficos el valor promedio de Mg++ fue de 1.7 +/- 0.06 mEq/l El valor promedio de Mg++ en los ninos con kwashiorkor fue significativamente menor que en los desnutridos marasmaticos y los ninos eurotroficos, p < 0.01. No se encontro diferencia entre los desnutridos mararasmaticos y el grupo control. Se analizan las posibles hipotesis que explicarian estas diferencias