Triggered electromyography (tEMG) in the lumbar spine It́s reliable? Correlation of tEMG with postoperative CT images in lumbar instrumentation. / Electromiografía evocada (tEMG) en la columna lumbar. ¿Es confiable? Correlación de tEMG con imágenes de TC posoperatorias en la instrumentación lumbar.

INTRODUCTION: Instrumentation with pedicle screws (PS) can compromise the adjacent neural structures. Triggered electromyography (tEMG) is a modality of intraoperative neuromonitoring, used to assist in the placement of these. The objective of the present study is to evaluate the reliability of this tool. METHOD: Retrospective review of patients underwent posterior lumbar fusions from January 2017 to December 2019, correlating postoperative CT images (postop CT) with tEMG results for each PS with a threshold of 10mA, establishing sensitivity and specificity of this tool. Diagnostic test and receiver operating characteristic curve were performed to evaluate the area under the curve. RESULT: A total of 275 PS were evaluated between L1 to S1; 5 PS showed concordance for an inadequate trajectory, while 10PS, with tEMG <10mA, were correctly positioned. The postoperative CT identified 17 pedicle gaps not noticed by the tEMG. Sensitivity and specificity were 23% (95% CI: 8-45) and 96% (95% CI: 93-98), respectively, with a PPV of 33.3% and a NPV of 93.6%. The area under the curve was 0.74 (95% CI: 0.62-0.86) with a cut-off point of 24mA, showing a sensitivity of 77% (95% CI: 0.55-0.92) and specificity of 69% (95% CI: 0.63-0.75). CONCLUSION: Given its low sensitivity, we do not recommend tEMG as the sole test in the verification of PS. We recommend using a cut-off point ≤8mA as it demonstrated the highest levels of sensitivity and specificity. We do not recommend using high thresholds to increase sensitivity.

Electromiografía evocada (tEMG) en la columna lumbar. ¿Es confiable? Correlación de tEMG con imágenes de TC posoperatorias en la instrumentación lumbar / Triggered electromyography (tEMG) in the lumbar spine Its reliable? Correlation of tEMG with postoperative CT images in lumbar instrumentation

Introducción: La instrumentación con tornillos pediculares (TP) puede comprometer las estructuras neurales adyacentes. La electromiografía evocada (tEMG) es una modalidad del neuromonitoreo intraoperatorio utilizada para asistir la colocación de estos. El objetivo del presente estudio es evaluar la confiabilidad de esta herramienta. Método: Revisión retrospectiva de pacientes intervenidos de artrodesis lumbar posterolateral instrumentada desde enero del 2017 hasta diciembre del 2019. Se correlacionaron las imágenes de TC postoperatorias (TC-postop) con los resultados de la tEMG para cada TP con un umbral de 10mA, y se establecieron la sensibilidad y especificidad de esta herramienta. Se realizó test diagnóstico y la curva característica operativa del receptor para evaluar el área bajo la curva. Resultado: Se evaluaron 275 TP entre L1 y S1; 5 TP presentaban concordancia para una trayectoria inadecuada, mientras que 10TP, con tEMG <10mA, se encontraban correctamente posicionados. La TC-postop identificó 17 brechas pediculares no advertidas por la tEMG. La sensibilidad y la especificidad fue del 23% (IC 95%: 8-45) y 96% (IC 95%: 93-98), respectivamente, con un VPP del 33,3% y un VPN del 93,6%. El área bajo la curva fue de 0,74 (IC 95%: 0,62-0,86) con punto de corte de 24mA, que mostró una sensibilidad del 77% (IC 95%: 0,55-0,92) y una especificidad del 69% (IC 95%: 0,63-0,75). Conclusión: Dada su baja sensibilidad, no aconsejamos la tEMG como prueba única en la verificación de TP. Recomendamos la utilización de un punto de corte ≤8mA, ya que ha demostrado los niveles más altos de sensibilidad y especificidad. No recomendamos el uso de umbrales elevados para aumentar la sensibilidad.(AU)

Introduction: Instrumentation with pedicle screws (PS) can compromise the adjacent neural structures. Triggered electromyography (tEMG) is a modality of intraoperative neuromonitoring, used to assist in the placement of these. The objective of the present study is to evaluate the reliability of this tool. Method: Retrospective review of patients underwent posterior lumbar fusions from January 2017 to December 2019, correlating postoperative CT images (postop CT) with tEMG results for each PS with a threshold of 10mA, establishing sensitivity and specificity of this tool. Diagnostic test and receiver operating characteristic curve were performed to evaluate the area under the curve. Result: A total of 275 PS were evaluated between L1 to S1; 5 PS showed concordance for an inadequate trajectory, while 10PS, with tEMG <10mA, were correctly positioned. The postoperative CT identified 17 pedicle gaps not noticed by the tEMG. Sensitivity and specificity were 23% (95% CI: 8-45) and 96% (95% CI: 93-98), respectively, with a PPV of 33.3% and a NPV of 93.6%. The area under the curve was 0.74 (95% CI: 0.62-0.86) with a cut-off point of 24mA, showing a sensitivity of 77% (95% CI: 0.55-0.92) and specificity of 69% (95% CI: 0.63-0.75). Conclusion: Given its low sensitivity, we do not recommend tEMG as the sole test in the verification of PS. We recommend using a cut-off point ≤8mA as it demonstrated the highest levels of sensitivity and specificity. We do not recommend using high thresholds to increase sensitivity.(AU)

Triggered electromyography (tEMG) in the lumbar spine it's reliable? Correlation of tEMG with postoperative CT images in lumbar instrumentation / Electromiografía evocada (tEMG) en la columna lumbar. ¿Es confiable? Correlación de tEMG con imágenes de TC posoperatorias en la instrumentación lumbar

Introduction: Instrumentation with pedicle screws (PS) can compromise the adjacent neural structures. Triggered electromyography (tEMG) is a modality of intraoperative neuromonitoring, used to assist in the placement of these. The objective of the present study is to evaluate the reliability of this tool. Method: Retrospective review of patients underwent posterior lumbar fusions from January 2017 to December 2019, correlating postoperative CT images (postop CT) with tEMG results for each PS with a threshold of 10mA, establishing sensitivity and specificity of this tool. Diagnostic test and receiver operating characteristic curve were performed to evaluate the area under the curve. Result: A total of 275 PS were evaluated between L1 to S1; 5 PS showed concordance for an inadequate trajectory, while 10PS, with tEMG <10mA, were correctly positioned. The postoperative CT identified 17 pedicle gaps not noticed by the tEMG. Sensitivity and specificity were 23% (95% CI: 8-45) and 96% (95% CI: 93-98), respectively, with a PPV of 33.3% and a NPV of 93.6%. The area under the curve was 0.74 (95% CI: 0.62-0.86) with a cut-off point of 24mA, showing a sensitivity of 77% (95% CI: 0.55-0.92) and specificity of 69% (95% CI: 0.63-0.75). Conclusion: Given its low sensitivity, we do not recommend tEMG as the sole test in the verification of PS. We recommend using a cut-off point ≤8mA as it demonstrated the highest levels of sensitivity and specificity. We do not recommend using high thresholds to increase sensitivity.(AU)

Introducción: La instrumentación con tornillos pediculares (TP) puede comprometer las estructuras neurales adyacentes. La electromiografía evocada (tEMG) es una modalidad del neuromonitoreo intraoperatorio utilizada para asistir la colocación de estos. El objetivo del presente estudio es evaluar la confiabilidad de esta herramienta. Método: Revisión retrospectiva de pacientes intervenidos de artrodesis lumbar posterolateral instrumentada desde enero del 2017 hasta diciembre del 2019. Se correlacionaron las imágenes de TC postoperatorias (TC-postop) con los resultados de la tEMG para cada TP con un umbral de 10mA, y se establecieron la sensibilidad y especificidad de esta herramienta. Se realizó test diagnóstico y la curva característica operativa del receptor para evaluar el área bajo la curva. Resultado: Se evaluaron 275 TP entre L1 y S1; 5 TP presentaban concordancia para una trayectoria inadecuada, mientras que 10TP, con tEMG <10mA, se encontraban correctamente posicionados. La TC-postop identificó 17 brechas pediculares no advertidas por la tEMG. La sensibilidad y la especificidad fue del 23% (IC 95%: 8-45) y 96% (IC 95%: 93-98), respectivamente, con un VPP del 33,3% y un VPN del 93,6%. El área bajo la curva fue de 0,74 (IC 95%: 0,62-0,86) con punto de corte de 24mA, que mostró una sensibilidad del 77% (IC 95%: 0,55-0,92) y una especificidad del 69% (IC 95%: 0,63-0,75). Conclusión: Dada su baja sensibilidad, no aconsejamos la tEMG como prueba única en la verificación de TP. Recomendamos la utilización de un punto de corte ≤8mA, ya que ha demostrado los niveles más altos de sensibilidad y especificidad. No recomendamos el uso de umbrales elevados para aumentar la sensibilidad.(AU)

Respiratory medicine curriculum in Portuguese family medicine training: A Delphi study.

BACKGROUND: Respiratory diseases (RD) constitute a significant part of the workload of family physicians. There is no consensus on what family doctors should know in this area but established methods for achieving consensus may help to overcome this. OBJECTIVES: The purpose of the study was to obtain a national consensus on the required knowledge and skills in respiratory medicine for family medicine trainees after vocational training. METHODS: A Delphi study was conducted via e-mail with a diverse panel of experts. We developed a Learning Curriculum Framework (LCF) with 399 items adapted from the Royal Australasian College of Physicians - Respiratory Medicine Advanced Training Curriculum. The LCF was submitted to the experts in two rounds for consensus. Consensus was considered for items that had an agreement of 80% in the classifications above 4 on a scale of importance that ranged from 1 (not important) to 5 (very important). RESULTS: Consensus was obtained for 159 items (38.8%). These included structure and function of the respiratory tract (0.6%), presenting problems (21.4%), diagnosis (7.5%), interventions and prevention (11.3%), COPD-emphysema (12.6%), tumours (3.1%), infections (10.7%), tuberculosis (5.7%), HIV (1.3%), thromboembolic disease (2.5%), pleural-pulmonary disease (3.1%), pregnancy (0.6%) and sleep disorders (3.8%). Items on iatrogenic diseases and respiratory research did not reach consensus. CONCLUSIONS: Consensus on the respiratory medicine curriculum may contribute to further development of the vocational training curriculum in Portugal. This approach may help teachers in other countries in Europe to develop curricula for respiratory medicine and other areas of general practice.

Wild carnivores, domestic dogs and ticks: shared parasitism in the Brazilian Cerrado.

The increase of contact between natural and rural areas is prominent in Brazil, due to agricultural activities and concern with the environmental conservation. In this context, domestic animals, wild fauna and humans are exposed to mutual exchange of parasites, microorganisms and diseases. We studied tick parasitism of wild carnivores and domestic dogs, and the environmental of questing ticks, in extensive cattle ranch areas intermingled with natural vegetation, and in a natural reserve, both in a region of Cerrado biome, Midwestern Brazil. From 2008 to 2015, we inspected 119 wild carnivores from nine species, and collected six tick species (Amblyomma sculptum, Amblyomma ovale, Amblyomma dubitatum, Amblyomma tigrinum, Dermacentor nitens and Rhipicephalus microplus). The most numerous and infested hosts were Cerdocyon thous, Lycalopex vetulus, Chrysocyon brachyurus, Puma concolor and Conepatus amazonicus. From 139 domestic dogs, we collected A. sculptum, Rhipicephalus sanguineus and R. microplus. From vegetation, samplings resulted in A. sculptum, A. dubitatum, A. ovale, Amblyomma rotundatum and R. microplus, with dominance of A. sculptum. Domestics and wild animals presented high overlapping of infestations by A. sculptum, a generalist and anthropophilic tick species. This tick is the most important vector of the Brazilian spotted fever, a lethal human disease. This fact elicits attention and requires efforts to monitor the presence of pathogens vectored by ticks circulating in this type of agroecosystem, including in other regions of the Brazil, because the most of the natural vegetation remaining have been increasingly immersed in pastures and agricultural matrix.

Galectin-3 orchestrates the histology of mesentery and protects liver during lupus-like syndrome induced by pristane.

Galectin-3 (Gal-3) controls intercellular and cell-extracellular matrix interactions during immunological responses. In chronic inflammation, Gal-3 is associated with fibrotic events, regulates B cell differentiation and delays lupus progression. Gal-3 deficient mice (Lgals3-/-) have intense germinal center formation and atypical plasma cell generation correlated to high levels IgG, IgE, and IgA. Here, we used pristane (2,6,10,14-tetramethylpentadecane) to induce lupus-like syndrome in Lgals3-/- and Lgals3+/+ BALB/c mice. Mesentery and peritoneal cells were monitored because promptly react to pristane injected in the peritoneal cavity. For the first time, mesenteric tissues have been associated to the pathogenesis of experimental lupus-like syndrome. In Lgals3+/+ pristane-induced mice, mesentery was hallmarked by intense fibrogranulomatous reaction restricted to submesothelial regions and organized niches containing macrophages and B lymphocytes and plasma cells. In contrast, Lgals3-/- pristane-treated mice had diffuse mesenteric fibrosis affecting submesothelium and peripheral tissues, atypical M1/M2 macrophage polarization and significant DLL1+ cells expansion, suggesting possible involvement of Notch/Delta pathways in the disease. Early inflammatory reaction to pristane was characterized by significant disturbances on monocyte recruitment, macrophage differentiation and dendritic cell (DC) responses in the peritoneal cavity of pristane-induced Lgals3-/- mice. A correlative analysis showed that mesenteric damages in the absence of Gal-3 were directly associated with severe portal inflammation and hepatitis. In conclusion, it has suggested that Gal-3 orchestrates histological organization in the mesentery and prevents lupoid hepatitis in experimental lupus-like syndrome by controlling macrophage polarization, Notch signaling pathways and DC differentiation in mesenteric structures.

Properties of chars from the gasification and pyrolysis of rice waste streams towards their valorisation as adsorbent materials.

Rice straw (RS), rice husk (RH) and polyethylene (PE) were blended and submitted to gasification and pyrolysis processes. The chars obtained were submitted to textural, chemical, and ecotoxic characterisations, towards their possible valorisation. Gasification chars were mainly composed of ashes (73.4-89.8wt%), while pyrolysis chars were mainly composed of carbon (53.0-57.6wt%). Silicon (Si) was the major mineral element in all chars followed by alkaline and alkaline-earth metal species (AAEMs). In the pyrolysis chars, titanium (Ti) was also a major element, as the feedstock blends contained high fractions of PE which was the main source of Ti. Gasification chars showed higher surface areas (26.9-62.9m2g-1) and some microporosity, attributed to porous silica. On the contrary, pyrolysis chars did not present a porous matrix, mainly due to their high volatile matter content. The gasification bed char produced with 100% RH, at 850°C, with O2 as gasification agent, was selected for further characterization. This char presented the higher potential to be valorised as adsorbent material (higher surface area, higher content of metal cations with exchangeable capacity, and lowest concentrations of toxic heavy metals). The char was submitted to an aqueous leaching test to assess the mobility of chemical species and the ecotoxic level for V. fischeri. It was observed that metallic elements were significantly retained in the char, which was attributed mainly to its alkaline character. This alkaline condition promoted some ecotoxicity level on the char eluate that was eliminated after the pH correction.

Haploidentical hematopoietic stem cell transplantation in children with high-risk hematologic malignancies: outcomes with two different strategies for GvHD prevention. Ex vivo T-cell depletion and post-transplant cyclophosphamide: 10 years of experience at a single center.

Forty patients with high-risk hematologic malignancies, median age 9 years, underwent haploidentical-HSCT from April 2005 to April 2015. Seventeen patients were transplanted with CD3-depleted PBSCs by negative selection (TCD group) following a reduced-intensity conditioning regimen (RIC), and 23 patients received T-cell-replete PBSCs followed by post-transplantation cyclophosphamide (PT-Cy group) after myeloablative conditioning (n=16) or RIC (n=7). Outcomes are reported for the TCD and PT-Cy recipients, respectively. Engraftment was achieved in 88% versus 100%. Median time to neutrophils>500/µL was 10 days versus 15 days. Platelets>20 000/µL occurred at a median of 16 days versus 20 days, respectively. Transplant-related mortality (TRM) was 24% versus 26% at 1 year. The cumulative incidence (CI) of grade III-IV acute GvHD was 7% versus 5%, and chronic GvHD 9% versus 53% (P=0.029). Relapse at 2 years was 31% versus 24%. Actuarial overall survival rates at 2 years were 47% versus 48%. Causes of death were infections (n=3), sinusoidal obstructive syndrome (n=4), acute GvHD (n=2) and relapse (n=9). These results indicate that haploidentical-HSCT is feasible in Uruguay. The TRM rate is of concern and should be the focus of continuing attention. Chronic GvHD risk was higher in the PT-Cy approach, so modifications are justified.

Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities.

BACKGROUND: Plants are hotbeds for parasites such as arthropod herbivores, which acquire nutrients and energy from their hosts in order to grow and reproduce. Hence plants are selected to evolve resistance, which in turn selects for herbivores that can cope with this resistance. To preserve their fitness when attacked by herbivores, plants can employ complex strategies that include reallocation of resources and the production of defensive metabolites and structures. Plant defences can be either prefabricated or be produced only upon attack. Those that are ready-made are referred to as constitutive defences. Some constitutive defences are operational at any time while others require activation. Defences produced only when herbivores are present are referred to as induced defences. These can be established via de novo biosynthesis of defensive substances or via modifications of prefabricated substances and consequently these are active only when needed. Inducibility of defence may serve to save energy and to prevent self-intoxication but also implies that there is a delay in these defences becoming operational. Induced defences can be characterized by alterations in plant morphology and molecular chemistry and are associated with a decrease in herbivore performance. These alterations are set in motion by signals generated by herbivores. Finally, a subset of induced metabolites are released into the air as volatiles and function as a beacon for foraging natural enemies searching for prey, and this is referred to as induced indirect defence. SCOPE: The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can give rise to exploitative competition and facilitation within ecological communities "inhabiting" a plant. CONCLUSIONS: Herbivores have evolved diverse strategies, which are not mutually exclusive, to decrease the negative effects of plant defences in order to maximize the conversion of plant material into offspring. Numerous adaptations have been found in herbivores, enabling them to dismantle or bypass defensive barriers, to avoid tissues with relatively high levels of defensive chemicals or to metabolize these chemicals once ingested. In addition, some herbivores interfere with the onset or completion of induced plant defences, resulting in the plant's resistance being partly or fully suppressed. The ability to suppress induced plant defences appears to occur across plant parasites from different kingdoms, including herbivorous arthropods, and there is remarkable diversity in suppression mechanisms. Suppression may strongly affect the structure of the food web, because the ability to suppress the activation of defences of a communal host may facilitate competitors, whereas the ability of a herbivore to cope with activated plant defences will not. Further characterization of the mechanisms and traits that give rise to suppression of plant defences will enable us to determine their role in shaping direct and indirect interactions in food webs and the extent to which these determine the coexistence and persistence of species.

Impact of the BEA zeolite morphology on isobutane adsorption followed by Reversed-Flow Inverse Gas Chromatography.

The mass transfer phenomena of isobutane (i-C4) were investigated at 343K on three protonic BEA zeolites. Defined by their crystallites sizes and degrees of aggregation, these samples were characterized by Reversed-Flow Inverse Gas Chromatography (RF-GC). This simple technique, used in conjunction with numerical computation, allowed the determination of physicochemical quantities like local monolayer capacities, probability density functions and diffusion coefficients in a time-resolved way. This study enabled to conclude that the effective diffusion coefficient was affected by the size of the zeolite agglomerate whereas the surface diffusion depended on the zeolite crystallite size.

Autophagy and apoptosis interplay during follicular atresia in fish ovary: a morphological and immunocytochemical study.

Follicular atresia in fish ovary provides an interesting model for studying autophagy and apoptosis. In order to improve knowledge of the mechanisms regulating ovarian regression, we investigated the immunolocalisation of various proteins involved in the complex network of autophagy and apoptosis. Females of three species of freshwater fish maintained in captivity were sampled after the reproductive period and the main events of follicular atresia were assessed by histology: splits in the zona radiata, yolk degradation and reabsorption, hypertrophy of the follicular cells, accumulation of autophagic vacuoles, closing of the follicular lumen and thickening of the theca. The interplay of apoptosis and autophagy was analysed by TUNEL in situ and by immunocytochemistry for caspase-3, bax, bcl-2, beclin-1 and cathepsin-D. During early and advanced stages of follicular regression, the actin cytoskeleton was well developed and labelling for bcl-2 and cathepsin-D were pronounced in the follicular cells at a stage when they were intensively involved in yolk phagocytosis. Immunofluorescence for beclin-1 was prevalent in the follicular cells, punctate labelling often surrounding autophagic vacuoles during the advanced stage of follicular regression, a critical step towards cell death. TUNEL-positive reaction and immunostaining for bax and caspase-3 demonstrated the participation of apoptosis in late follicular regression. Overall, this study provides evidence that autophagic and apoptotic proteins are activated in a coordinated fashion depending on the stage of follicular regression, with interplay between autophagy and apoptosis being essential in determining the fate of the cell during follicular atresia in fish ovary.

Feasibility and outcome of haploidentical SCT in pediatric high-risk hematologic malignancies and Fanconi anemia in Uruguay.

In total, 17 pediatric patients with hematologic malignancies (n=14) and Fanconi anemia (FA) (n=3) underwent haploidentical SCT with T-cell depletion. The patients were conditioned with reduced-intensity regimens, and CYA was used for GVHD prophylaxis. Successful engraftment occurred in 16 patients (94%). One patient failed to achieve a primary engraftment. Another patient rejected the first SCT after 10 weeks and had a successful second transplant. Of all engrafted patients, only one developed severe acute GVHD. Ten patients were alive at a median follow-up of 18 months (range, 5-62 months). The 5-years' OS was 53.8%. The three patients with FA are currently well with full-donor chimerism at 16, 6 and 5 months post transplant, respectively. The OS of 14 patients with high-risk hematologic malignancies was 47.6%. Three patients died as a result of post transplant leukemia relapse. CMV infection, GVHD and organ injury were other causes of mortality. Haploidentical SCT was found to be an alternative feasible treatment in Uruguay for patients who need allogenic transplantation but lack an HLA-identical family donor. It should be considered as an early option in FA patients before transformation or significant exposure to blood products.

Enhancing the thermal stability of lipases through mutagenesis and immobilization on zeolites.

The hydrolysis reaction of p-nitrophenyl butyrate catalyzed by lipases was followed with in situ UV/vis diode array spectrophotometry. Five enzymes - Candida antarctica lipase B and Fusarium solani pisi cutinase wild-type and three single-mutation variants - were tested as catalysts in homogeneous conditions and immobilized on zeolite NaY, on a polyacrylate support and as cross-linked aggregates. Using deconvolution techniques and kinetic modeling, the thermal stability of the different biocatalysts was compared in operational conditions and the results were supported by steady-state enzyme fluorescence measurements. We concluded that both the mutagenesis and the immobilization on zeolite NaY had a positive effect on the thermal stability of F. solani pisi cutinase.

Following multi-component reactions in liquid medium using spectral band-fitting techniques.

The kinetics of the hydrolysis reaction of p-nitrophenyl butyrate catalyzed by a single-site mutant of Fusarium solani pisi cutinase, supported on zeolite NaY by adsorption, was followed using ultraviolet-visible (UV/Vis) in situ diode array spectrophotometry. Spectral band-fitting techniques allowed the use of in situ diode array spectrophotometry to obtain quantitative data on the concentrations of the various species present in an aqueous reaction medium even in the presence of the solid catalyst particles, which interfere with the absorption measurements. This technique overcame the problems arising from the variable light scattering produced by these highly dispersible catalyst particles. Kinetic modeling of the reaction system was used to compute estimates of the reaction rate constants involved.

Comparing the effect of immobilization methods on the activity of lipase biocatalysts in ester hydrolysis.

The activity of various lipases was compared, in both free and immobilized forms, using the kinetics of the hydrolysis reaction of p-nitrophenyl butyrate, which was followed with in situ UV/Vis diode array spectrophotometry. Several enzymes were used to catalyze the reaction, namely Candida antarctica lipase B and Fusarium solani pisi cutinase wildtype and three single-mutation variants. The enzymes were tested in three different forms: free, immobilized as cross-linked aggregates and supported on zeolite NaY. A simple kinetic model was used to allow a quantitative comparison of the behavior of the different catalysts. It was concluded that although immobilization reduces the activity of the enzyme, the zeolite offers a much higher specific activity when compared to the cross-linked aggregates, thus supplying a heterogeneous catalyst with promising catalytic properties.

Cellular autoreactivity against heat shock protein 60 in renal transplant patients: peripheral and graft-infiltrating responses.

Autoreactivity to heat shock protein 60 (Hsp60) has been implicated in the pathogenesis and regulation of chronic inflammation, especially in autoimmune diseases. In transplantation, there is a lack of information regarding the cytokine profile and specificity of cells that recognize self-Hsp60 as well as the kinetics of autoreactivity following transplantation. We studied the cellular reactivity of peripheral and graft-infiltrating lymphocytes against Hsp60 in renal transplant patients. Cytokine production induced by this protein in peripheral blood mononuclear cells indicated a predominance of interleukin (IL)-10 during the late post-transplantation period, mainly in response to intermediate and C-terminal peptides. Patients with chronic rejection presented reactivity to Hsp60 with a higher IL-10/interferon (IFN)-gamma ratio compared to long-term clinically stable patients. Graft-infiltrating T cell lines, cocultured with antigen-presenting cells, preferentially produced IL-10 after Hsp60 stimulation. These results suggest that, besides its proinflammatory activity, autoreactivity to Hsp60 in transplantation may also have a regulatory role.

Kinetic modelling of phenol co-oxidation using horseradish peroxidase.

Phenol is an industrial pollutant and its removal from industrial wastewaters is of great importance. In order to design optimised phenol removal procedures by using horseradish peroxidase-based systems, there are some points that have to be dealt with. One of the most important issues is the need for reliable kinetics as this is one of the difficulties found during process scale-up. Although simplified kinetics can be used for limited ranges of operating conditions, they are not usually reliable for the description of varying process conditions. The present work describes the implementation of a kinetic model, based on a mechanism, for the co-oxidation of phenol and 4-aminoantipyrine (Am-NH2), which is used as a chromogen agent, with hydrogen peroxide as the oxidant. The model covers not only the variation of the concentrations of all the species involved, but also the effect of temperature in the reaction. The estimation of kinetic rate constants and activation energies for the various steps in the mechanism is performed with a single optimisation procedure, and all the experimental results are described using a unique set of parameters, which, thus, is valid over an extended range of operating conditions. The mechanism allowed the determination of a reliable kinetic model which is appropriate for the range of experimental conditions used. The computational model was also tested with an independent set of experiments with different conditions from the ones for which the parameters were estimated.

Identifying cyclosporine blood levels associated with the prevention of renal transplant rejection: a single-center, randomized prospective study.

Multiple-drug therapy may allow reduced individual drug doses with fewer side effects. Blood levels of cyclosporine (CsA) necessary to avoid rejection may vary with different drug combinations. Fifty-eight kidney transplant patients were randomized into two groups: 25 subjects were assigned to the 4-hour area under the curve (AUC(0-4)) Cohort-the "high arm" (4500 to 5500 ng . h/mL)--1 and 33 to the AUC(0-4) "low arm" (2400 to 3400 ng . h/mL). After CsA introduction, AUC(0-4) was drawn on days 4, 7, 14, 21, 28, 42, 56, 70, 84, 90. We compared the proportion of rejection versus rejection-free patients, according to the CsA exposure. Logistic regression analysis showed that an AUC(0-4) of > or =4000 ng . h/mL or a 2-hour cyclosporine level (C(2)) of > or =1450 ng/mL predicted a rejection-free course among patients not receiving induction therapy. When either basiliximab or thymoglobulin was administered, a C(2) and AUC(0-4) of 1043 +/- 151 ng/mL or 3146 +/- 262 ng . h/mL, respectively, were associated with a rejection-free course. Our findings confirm the need for different CsA levels to prevent rejection according to induction therapy. Induction with either basiliximab or thymoglobulin allows reduced CsA levels during the first 3 months after renal transplantation.

Modelling of ex vivo expansion/maintenance of hematopoietic stem cells.

In this study, we described the modelling of the expansion/maintenance of human hematopoietic stem/progenitor cells from adult human bone marrow. CD 34(+)-enriched cell populations from bone marrow were cultured in the presence and absence of human stroma in serum-free media containing bFGF, SCF, LIF and Flt-3 ligand for several days. The cells in the culture were analysed for expansion and phenotype by flow cytometry. Although significant expansion of bone marrow cultures occurred in the presence and absence of human stroma, the results of expansion were effectively better in the presence of a stromal layer. In both situations the phenotypic analysis demonstrated a great expansion of CD 34(+)38(-) cells. The differentiative potential of bone marrow CD 34(+) cells co-cultured with human stroma was primarily shifted towards the myeloid lineage with the presence of CD 15 and CD 33.

Introduction of mycophenolate mofetil and cyclosporin reduction in children with chronic transplant nephropathy.

Chronic transplant nephropathy (CTN) is the most important cause of kidney graft dysfunction. Studies in adult populations have reported a beneficial effect of non-nephrotoxic mycophenolate mofetil (MMF) on graft function in this setting. However, few studies were reported in children in this setting. We therefore reviewed the charts/medical records of renal transplanted patients < 18 yr of age at a single center who had switched from azathioprine to MMF as a result of progressive loss in graft function, for which vascular, infectious, and urological causes were excluded. Serum creatinine (SCr) and calculated creatinine clearance were compared prior to and after MMF introduction. Thirteen patients (nine male/four female), followed-up for 59.3 +/- 35.4 months after transplantation, were analyzed. Age at MMF introduction was 14.2 +/- 3.6 yr. In 11 patients a previous biopsy had shown features of CTN and four patients also presented signs of chronic cyclosporin A (CsA) nephrotoxicity. MMF was started at a dose of 1211 +/- 351 mg/day, and the CsA dose was decreased from 6.69 +/- 3.15 mg/kg/day 6 months before MMF to 4.8 +/- 2.3 mg/kg/day at the time of MMF introduction. CsA was withdrawn in four patients. The median (25-75%) SCr value increased from 1.60 mg/dL (range 1.3 to 1.87 mg/dL) 6 months before MMF to 2.2 mg/dL (range 1.87-2.32 mg/dL) when MMF was introduced. Six months after introduction of MMF, the SCr level had decreased to 1.5 mg/dL (range 1.2-1.8 mg/dL) and remained stable until the last follow-up (17.5 +/- 9.2 months after MMF was started). A similar pattern occured with calculated SCr clearance. There were no acute rejections after changes in immunosuppression. The safety of MMF was also analyzed and in only one patient was the drug stopped as a result of intractable diarrhea. These findings suggest that MMF is sufficiently powerful to allow a decrease/withdrawal of CsA without the burden of acute rejection in a pediatric population with CTN.