The non-vesicle cell-free DNA (cfDNA) induces cell transformation associated with horizontal DNA transfer.

BACKGROUND: Cell-free DNA (cfDNA) is a source for liquid biopsy used for cancer diagnosis, therapy selection, and disease monitoring due to its non-invasive nature and ease of extraction. However, cfDNA also participates in cancer development and progression by horizontal transfer. In humans, cfDNA circulates complexed with extracellular vesicles (EV) and macromolecular complexes such as nucleosomes, lipids, and serum proteins. The present study aimed to demonstrate whether cfDNA not associated with EV induces cell transformation and tumorigenesis. METHODS: Supernatant of the SW480 human colon cancer cell line was processed by ultracentrifugation to obtain a soluble fraction (SF) and a fraction associated with EV (EVF). Primary murine embryonic fibroblast cells (NIH3T3) underwent passive transfection with these fractions, and cell proliferation, cell cycle, apoptosis, cell transformation, and tumorigenic assays were performed. Next, cfDNA was analyzed by electronic microscopy, and horizontal transfer was assessed by human mutant KRAS in recipient cells via PCR and recipient cell internalization via fluorescence microscopy. RESULTS: The results showed that the SF but not the EVF of cfDNA induced proliferative and antiapoptotic effects, cell transformation, and tumorigenesis in nude mice, which were reduced by digestion with DNAse I and proteinase K. These effects were associated with horizontal DNA transfer and cfDNA internalization into recipient cells. CONCLUSIONS: The results suggest pro-tumorigenic effects of cfDNA in the SF that can be offset by enzyme treatment. Further exploration of the horizontal tumor progression phenomenon mediated by cfDNA is needed to determine whether its manipulation may play a role in cancer therapy.

Nanoscale Dynamics of Streptococcal Adhesion to AGE-Modified Collagen.

The adhesion of initial colonizers such as Streptococcus mutans to collagen is critical for dentinal and root caries progression. One of the most described pathological and aging-associated changes in collagen-including dentinal collagen-is the generation of advanced glycation end-products (AGEs) such as methylglyoxal (MGO)-derived AGEs. Despite previous reports suggesting that AGEs alter bacterial adhesion to collagen, the biophysics driving oral streptococcal attachment to MGO-modified collagen remains largely understudied. Thus, the aim of this work was to unravel the dynamics of the initial adhesion of S. mutans to type I collagen in the presence and absence of MGO-derived AGEs by employing bacterial cell force spectroscopy with atomic force microscopy (AFM). Type I collagen gels were treated with 10 mM MGO to induce AGE formation, which was characterized with microscopy and enzyme-linked immunosorbent assay. Subsequently, AFM cantilevers were functionalized with living S. mutans UA 159 or Streptococcus sanguinis SK 36 cells and probed against collagen surfaces to obtain force curves displaying bacterial attachment in real time, from which the adhesion force, number of events, Poisson analysis, and contour and rupture lengths for each individual detachment event were computed. Furthermore, in silico computer simulation docking studies between the relevant S. mutans UA 159 collagen-binding protein SpaP and collagen were computed, in the presence and absence of MGO. Overall, results showed that MGO modification increased both the number and adhesion force of single-unbinding events between S. mutans and collagen, without altering the contour or rupture lengths. Both experimental and in silico simulations suggest that this effect is due to increased specific and nonspecific forces and interactions between S. mutans UA 159 and MGO-modified collagen substrates. In summary, these results suggest that collagen alterations due to aging and glycation may play a role in early bacterial adherence to oral tissues, associated with conditions such as aging or chronic hyperglycemia, among others.

Dominio del fonoaudiólogo para la determinación del grado de viscosidad de alimentos líquidos / Speech pathologists proficiency for determining viscosity grade in liquid foods

La disfagia es una alteración del proceso deglutorio que afecta la seguridad, eficacia y calidad de la alimentación. Una de las estrategias más utilizadas para su intervención es la modificación de la viscosidad de los alimentos, sin embargo, la metodología empleada para determinarla es subjetiva y no está estandarizada. Esta investigación buscó establecer el dominio de los fonoaudiólogos para determinar el tipo de viscosidad. Se utilizaron 12 muestras de alimentos líquidos, cuyas viscosidades fueron determinadas objetivamente con un viscosímetro rotacional, clasificándolos bajo las categorías: fino, néctar, miel y pudín. Posteriormente, cuarenta fonoaudiólogos que se desempeñan en el área de los trastornos de la deglución en centros de salud de la Región Metropolitana en Santiago de Chile, evaluaron subjetivamente las 12 muestras. Con esta información se realizó un estudio comparativo objetivo/subjetivo para establecer el dominio de los profesionales. Los participantes lograron 66,87 por ciento de efectividad en la valoración del grado de viscosidad de las muestras, con un mejor rendimiento para aquellas viscosidades tipo fino y pudín. La repetibilidad intrasujeto fue superior a 75 por ciento para el 60 por ciento de la muestra. Existen además indicadores de que el tiempo de ejercicio profesional incidiría positivamente en estas capacidades, no así el nivel de perfeccionamiento. Por último, se establece que los fonoaudiólogos evaluados poseen un dominio regular para determinar el grado de viscosidad de alimentos líquidos, pero este no es homogéneo. Se hace necesario incentivar el conocimiento y manejo adecuado en este tema, en búsqueda de consensuar procedimientos y criterios que permitan una mayor estandarización al respecto.

Dysphagia is a disruption in the swallowing process which hinders movement of food, affecting the safety, efficiency and quality of feeding. Treatment includes different strategies, with viscosity modification being one of the most used strategies nowadays. However, the methodology used to determine food viscosity is subjective and not standardized. In this regard, this study seeks to establish the speech pathologists’ skills in determining the different types of food viscosity. Twelve samples of liquid foods were used, whose viscosities were determined objectively with a rotational viscometer. Then, the samples of liquid foods were classified into four categories: thin liquid, nectar, honey, and pudding. Forty speech pathologists working with patients diagnosed with dysphagia at health centers in the Metropolitan Region, Chile, subjectively evaluated the samples of liquid foods. Finally, an objective/subjective comparative study was performed to determine their competence in identifying the different types of food viscosity. Near 66,87 percent of the participants performed well in the task. Participants performed better in determining thin and pudding viscosities. Over 75 percent of intra-subject repeatability was obtained for 60 percent of the sample. Unlike postgraduate studies, it could be observed that professional experience has a positive impact on these skills. Finally, the results of this study indicate that the participants have intermediate skills in determining the degree of viscosity of liquid food. However, this is not homogeneous, and therefore, it is necessary to enhance our understanding and proper management of dysphagia. Agreement on standard procedures is also necessary.

Nicotinamide sensitizes human breast cancer cells to the cytotoxic effects of radiation and cisplatin.

Poly(ADP-ribose) polymerase (PARP) inhibitors enhance the effect of DNA alkylating agents on BRCA1­ and BRCA2-deficient cell lines. The aim of this study was to analyze the effect of the PARP inhibitor nicotinamide (NAM) on breast cancer cells with different BRCA1 expression or function, such as BRCA1­deficient MDA-MB-436 cells, low expression BRCA1 MCF-7 cells, and the BRCA1 wild­type MDA-MB-231 cells, to demonstrate its effects as a chemo­ or radiosensitizing agent. PARP activity was analyzed in MDA-MB-436, MCF-7 and MDA-MB-231 breast cancer cells subjected or not to NAM. Inhibition of PARP by NAM in the presence of DNA damage was examined by Alexa Fluor 488 immunofluorescence. Crystal violet assays were used to test growth inhibition and the chemo­ and radiosensitization effects of NAM were investigated using clonogenic assays. Significant differences among data sets were determined using two-tailed ANOVA and Bonferroni tests. We demonstrated that NAM reduces PARP activity in vitro, and in cells subjected or not to DNA damage, it also reduces the viability of breast cancer cell lines and synergyzes the cytotoxicity of cisplatin in MDA-MB-436 and MCF-7 cells. Downregulation of PARP1 with siRNA led to modest growth inhibition, which was further increased by cisplatin. Nicotinamide also induced radiosensitization in MDA-MB-436 and MDA-MB-231 cells. In conclusion, NAM may be used as a chemo­ or radiosensitizing agent regardless of the BRCA1 status in breast cancer.

Alternativas de derivación de LCR en pacientes de alta complejidad. Revisión de la literatura a raíz del caso de un recién nacido con Hidrocefalia post hemorrágica / Alternatives CSF shunt in patients highly complex: review of the literature following the case of a newborn with post hemorrhagic hydrocephalus

La hemorragia intraventricular (HIV) es una causa importante de daño cerebral en los recién nacidos prematuros. Su impacto negativo en el resultado del desarrollo neurológico se relaciona no sólo a su impacto directo, sino que también a las lesiones asociadas, como la hidrocefalia posthemorrágica (HPH). En la mayoría de los casos, la hidrocefalia es causada por la alteración de la reabsorción del líquido cefalorraquídeo (LCR) debido a la inflamación de las vellosidades subaracnoideas por el contacto con la sangre. El drenaje ventricular se utiliza a menudo como un procedimiento temporal para manejo de la HPH y algunos pacientes tratados con drenaje ventricular no requieren una derivación permanente; de no ser así, las derivaciones más usadas en los prematuros incluyen la ventriculoperitoneal (DVP), seguida por las derivaciones ventriculosubgaleal y ventriculoatrial. Las derivativas se consideran el tratamiento definitivo para la HPH; pero puede asociarse a complicaciones, tales como la infección, obstrucción, rechazo y el drenaje insuficiente. Otra alternativa, es la derivación ventrículopleural. Sin embargo, esta alternativa de derivación se vincula a otras complicaciones específicas, principalmente el neumotórax y el derrame pleural. Se presenta el caso clínico de EAV, quien a raíz de un parto prematuro, complicado con Hemorragia intraventricular, desarrolló Hidrocefalia y un quiste de Fosa Posterior, debiendo intervenirse en 36 oportunidades, por múltiples complicaciones. Durante su evolución se instalaron catéteres en prácticamente todos los sitios posibles, lográndose finalmente la solución del problema. Se revisa la literatura

Ventricular haemorrhage is an important cause of neurologic damage in preterm babies. Its negative impact in the final neurologic damage is not just related with the direct impact, but also with associated lesions like posthaemorrhagic hydrocephalus (PHH). In most of cases, hydrocephalus is caused by impaired cerebrospinal fluid (CEF) resorption due to the inflammation of the Arachnoid granulations because of the contact with blood. Ventricular drainage system is often used as a temporal procedure for the management of the PHH in children who have not a good response to serials lumbar punctures. Some patients treated with ventricular drainage don't need a permanent derivation, but if they do the most used in preterm babies include ventriculoperitoneal derivation (VPD) followed by ventriculosubgaleal and ventriculoatrial derivation. Derivation is considered the definitive treatment for PHH, but it can be associated with some complications as infection, obstruction and insufficient drainage. Another option is ventriculopleural derivation but this alternative is related to other complications like pneumothorax and pleural effusion. The presentation is about the case of the newborn EAV, who after preterm birth, complicated with intraventricular haemorrhage, developed hydrocephalus and a posterior fossa cyst, requiring 36 surgical interventions because of multiple complications. During its evolution he needed catheters installations in almost every possible sites, finally getting the problem solved. The literature is reviewed

Differential regulation of Notch ligands in dendritic cells upon interaction with T helper cells.

The Notch signalling pathway has recently been linked to T helper 1 (Th1)/T helper 2 (Th2) cell polarization via a mechanism involving differential expression of Notch ligands, Delta-like and Jagged, in antigen-presenting cells. However, whether stimuli other than pathogen-derived factors are involved in the regulation of Notch ligand expression in dendritic cells (DCs) remains unknown. Here, we address the effect of T helper cells (Th1 and Th2) on Delta-like 4 and Jagged 2 expression in bone marrow-derived DCs. We demonstrate that both Th1 and Th2 cells induce Delta-like 4 mRNA expression in DCs, in a process that is, in part, mediated by CD40 signalling. In contrast, only Th2 cells induce a significant increase in Jagged 2 mRNA levels in DCs. Additionally, we show that IL-4, a hallmark Th2 cytokine, plays a role in Jagged 2 expression, as evidenced by the fact that cholera toxin, a Th2-promoting stimulus, induces Jagged 2 mRNA expression in DCs only in the presence of IL-4. Finally, we demonstrate that DCs also express Notch 1 and that this expression is downregulated by IL-4. These data suggest that Notch ligands are differentially regulated in DCs: Delta-like 4 is regulated by T helper cells and by pathogen-derived Th1 stimuli, whereas Jagged 2 is regulated by Th2 cells and pathogen-derived Th2-promoting stimuli. Based on our results, we propose that the positive feedback loop that Th2 cells exert on T cell polarization may involve the induction of Jagged 2 expression in DCs.

Epigenetic therapy and cisplatin chemoradiation in FIGO stage IIIB cervical cancer.

INTRODUCTION: This trial aimed to evaluate the safety and efficacy of epigenetic therapy associated with cisplatin chemoradiation in FIGO Stage IIIB patients. METHODS: Hydralazine containing either 182 mg for rapid-, or 83 mg for slow acetylators and magnesium valproate were administered at 30 mg/kg tid. Both drugs were taken until intracavitary therapy was finished. Pelvic external beam radiation and low-dose rate brachytherapy were administered at a total cumulative dose to point A of at least 85 Gy. Weekly cisplatin at 40 mg/m2 was delivered for six cycles. RESULTS: Twenty-two patients were included and 18 (82%) patients completed treatment. Mean dose to point A was 84.6 + 2.2. Median number of cisplatin cycles was 5.5 (range, 1-6). Brachytherapy was delayed for technical reasons; the mean overall treatment time was 11.8 weeks. Grade 3 anemia, leucopenia, neutropenia, and thrombocytopenia were observed in 9%, 45%, 45%, and 9% of patients, respectively. CONCLUSIONS: Hydralazine and valproate are well-tolerated and safe when administered with cisplatin chemoradiation. Unfortunately, the suboptimal administration of brachytherapy for technical reasons in this study, precluded assessing the efficacy of epigenetic therapy. However, the tolerability of this regimen administered concurrent to radiation needs to be further tested.

Evaluation of late immunologic parameters among renal transplant recipients induced with Campath-1H.

Organ transplantation success depends principally on avoiding rejection, a purpose almost accomplished with immunosuppressant therapy. Nevertheless, drug side effects have promoted the search for other mechanisms to restrain alloresponses. T-regulatory cells (Treg) might exert that function. Campath 1H (C1H) induces Treg proliferation in the period subsequent to T-cell depletion following C1H administration. In the present study, the status of Treg and de novo HLA antibody production was determined posttransplantation when T-cell repopulation had been completed. In 14 patients, the following parameters were analyzed: renal function, rejection, Treg, panel-reactive antibody (PRA), and HLA antibodies. Patient and graft survivals were 100%. At the moment of Treg determination (20 months following transplant) the mean tacrolimus level was 8.4 ng/mL. One patient experienced an antibody-mediated rejection at 15 months after transplantation while having 3.2% Treg, with excellent treatment responses. Mean leukocyte and lymphocyte counts were 5752 and 1183 cells/mm(3); the mean peripheral blood percentage of Treg of 7.1% +/- 5.9% was not different from that observed in subjects without induction (mean 5.5% +/- 2.5%). Three patients (21%) showed Treg greater than 8.0%. In seven patients, we compared Treg at 4 and 20 months posttransplant, observing a decline from a mean of 19.9% to 5.9% (P = .05). In seven recipients, posttransplant PRA was determined; five of them became "de novo" sensitized, three with a mean class I PRA of 16% and two with a mean class II PRA of 37%. In conclusion, patient and graft survivals were excellent, mean Treg percentage was not elevated with results lower than in the early posttransplant period. Rejection incidence was negligible. Late "de novo" sensitization occurred in 70% showing that B cell-mediated alloresponses were only partially controlled among recipients induced with C1H even when associated with sustained anticalcineurin treatment.

Pectus excavatum: reparación con la técnica de Nuss. Serie de 10 casos / Pectus excavatum: repair with Nuss technique. A series of 10 cases

Antecedentes. En 1997 Donald Nuss y colaboradores publicaron su experiencia en la Reparación Mínimamente Invasiva del Pectus Excavatum (RIMPE). Esta técnica basada en los principios físicos de la caja torácica y en las observaciones hechas a partir de la técnica abierta cambió radicalmente el tratamiento de la enfermedad, siendo adoptada por los cirujanos en el mundo entero. Objetivo. Describir los resultados de la Reparación Mínimamente Invasiva del Pectus Excavatum (RIMPE) en la Clínica Infantil Colsubsidio. Material y métodos. Se realizó un estudio descriptivo de serie de casos de los pacientes tratados con la técnica de Nuss en la Clínica Infantil Colsubsidio durante el período comprendido entre diciembre 2004 y julio del 2008. La recolección de datos fue realizada con base en historias clínicas, tomando datos personales, familiares y paraclínicos. Se evaluaron los resultados quirúrgicos incluyendo tiempo de cirugía, complicaciones tempranas, complicaciones tardías y uso de analgésicos. Resultados. Se incluyeron 10 pacientes entre los 13 y 17 años. El 90 por ciento de los pacientes fueron hombres. El resultado estético fue satisfactorio en todos los casos. Las complicaciones más frecuentes fueron dos de neumotórax y dos de desplazamiento de la barra. No se presentó ningún caso de infección, alergia, derrame pleural, pericarditis, o hemotórax . Discusión. Esta serie de casos describe nuestra experiencia inicial, encontrando que la cirugía de Nuss es una técnica segura, reproducible, con buenos resultados en la mayoría de los pacientes y con una rápida recuperación funcional y estética. Las complicaciones que se presentaron en nuestra serie corresponden a las reportadas en la literatura mundial.

Alemtuzumab induction in kidney transplantation: clinical results and impact on T-regulatory cells.

Alemtuzumab (ALT), a humanized monoclonal anti-CD52 antibody, was introduced in solid organ transplantation as an induction agent. ALT associated with anticalcineurins has provided a low incidence of acute rejection episodes (ARE) and potential tolerogenic properties. We analyzed the clinical outcomes and effects on peripheral Treg of renal transplant recipients treated with ALT. Six-month data on kidney alone or kidney combined with pancreas or liver patients treated with ALT and tacrolimus (TAC) in standard doses were compared with those on renal transplant recipients of similar demography who were not treated with ALT. We evaluated patient and graft survivals, ARE incidence, hematological parameters, renal function, adverse events, and CD4+CD25+FoxP3+ T cells in peripheral blood. Demographics of recipients, donors, and transplants were similar in both groups. Mean HLA mismatch was slightly greater among ALT-treated patients (3.5 vs 2.5). No combined transplantation was performed in the ALT-untreated group. Patient and graft survivals were 100% without rejection or serious infections in both groups. ALT-treated recipients showed anemia and leukopenia in 3 patients as well as severe lymphopenia in 5 recipients, who partially recovered on day 90. Final mean plasma creatinine was 1.4 mg/dL, while calculated creatinine clearance was approximately 65 mL/min in both groups. Mean Treg cell percentage was higher among ALT-treated recipients than the comparative group or healthy controls (P < .05). In conclusion, renal transplantation results obtained using ALT with rigorous immunosuppressive therapy were excellent; serious adverse events and acute rejection were absent. The effect of the increased proportion of Treg cells must be evaluated with longer observation.

Metabolic changes following conversion from an anticalcineurin-based therapy to an everolimus-based one: a single-center experience.

Everolimus (EVL), an antagonist of mammalian target of rapamycin, has been recently introduced into solid organ transplantation either associated with low dose of anticalcineurins (CNI) or replacing them in an attempt to avoid nephrotoxicity and chronic allograft nephropathy. Due to the molecular similarities with sirolimus, it has been expected that there would be the same incidence of metabolic changes and adverse events. We retrospectively studied kidney allograft recipients converted from CNI to EVL during a 12-month period. Patients received a standard dose of EVL starting at 1.5 mg/d and thereafter titrating to achieve trough levels in the range of 3 to 5 ng/mL. Patients achieved mean EVL trough levels of 5.2, 4.0 and 4.5 ng/mL at 1, 6, and 12 months, respectively. One year following conversion, the calculated creatinine clearance increased from 57 to 63 mL/min and proteinuria did not change. Fasting blood glucose levels decreased significantly following conversion to EVL. During the same time, no significant changes were observed in body weight, body mass index, albumin, cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, lipid-lowering medication requirements, blood magnesium, and uric acid. We concluded that EVL did not negatively influence various nutritional parameters.

A phase II study of epigenetic therapy with hydralazine and magnesium valproate to overcome chemotherapy resistance in refractory solid tumors.

BACKGROUND: Epigenetic aberrations lead to chemotherapy resistance; hence, their reversal by inhibitors of DNA methylation and histone deacetylases may overcome it. PATIENTS AND METHODS: Phase II, single-arm study of hydralazine and magnesium valproate added to the same schedule of chemotherapy on which patients were progressing. Schedules comprised cisplatin, carboplatin, paclitaxel, vinorelbine, gemcitabine, pemetrexed, topotecan, doxorubicin, cyclophosphamide, and anastrozole. Patients received hydralazine at 182 mg for rapid, or 83 mg for slow, acetylators, and magnesium valproate at 40 mg/kg, beginning a week before chemotherapy. Response, toxicity, DNA methylation, histone deacetylase activity, plasma valproic acid, and hydralazine levels were evaluated. RESULTS: Seventeen patients were evaluable for toxicity and 15 for response. Primary sites included cervix (3), breast (3), lung (1), testis (1), and ovarian (7) carcinomas. A clinical benefit was observed in 12 (80%) patients: four PR, and eight SD. The most significant toxicity was hematologic. Reduction in global DNA methylation, histone deacetylase activity, and promoter demethylation were observed. CONCLUSIONS: The clinical benefit noted with the epigenetic agents hydralazine and valproate in this selected patient population progressing to chemotherapy' and re-challenged with the same chemotherapy schedule after initiating hydralazine and valproate' lends support to the epigenetic-driven tumor-cell chemoresistance hypothesis (ClinicalTrials.gov Identifier: NCT00404508).

Conversion from a calcineurin inhibitor-based immunosuppressive regimen to everolimus in renal transplant recipients: effect on renal function and proteinuria.

New immunosuppressive agents are being actively researched to avoid complications of chronic allograft nephropathy (CAN), calcineurin inhibitor (CNI) nephrotoxicity, and posttransplantation cancer. The family of mTOR inhibitors offers a unique immunosuppressive opportunity to avoid CNI toxicity and reduce the incidence of malignancy. Nevertheless, increasing data have demonstrated that sirolimus (SRL), the first mTOR introduced in the treatment of solid organ transplant recipients, induces proteinuria, an adverse event that could produce deterioration of long-term renal function. In this short-term study of patients followed for 1 to 16 months, we examined changes in renal function and proteinuria among renal transplant recipients converted from a CNI-based regimen to an everolimus (EVL)-based one, a recently introduced mTOR inhibitor. Our data showed that renal function can be optimized after conversion to EVL by up to 42% in recipients showing CAN grade 1 or 2, or CNI nephrotoxicity. Importantly, patients who improved their creatinine clearance did not show increased proteinuria measured in a voided specimen as the ratio of urinary protein and creatinine concentration (P/C). These results, if confirmed with long-term follow-up and a larger number of patients, would allow us to consider EVL as a promising agent for maintenance immunosuppressive regimens in kidney transplantation.

Interleukin-4 selectively inhibits interleukin-2 secretion by lipopolysaccharide-activated dendritic cells.

Dendritic cells (DCs) generated in vitro from bone marrow precursors using granulocyte-macrophage colony-stimulating factor (GM-CSF) secrete interleukin-2 (IL-2) upon activation, an event probably associated to the initiation of adaptive immune responses. Additionally, they produce IL-12, a cytokine related to T-cell polarization. To analyse the effect of IL-4 on DC differentiation and function, we assessed the capacity of murine bone marrow dendritic cells (BMDCs) differentiated with GM-CSF in the presence or absence of IL-4 to produce IL-2 and IL-12 upon lipopolysaccharide (LPS) activation. We found that although IL-4 enhanced DC IL-12p70 production, it strongly impaired IL-2 secretion by BMDCs. This inhibition, which depends on the presence of IL-4 during LPS activation, is DC specific, as IL-4 did not affect IL-2 secretion by T cells. Interestingly, inhibition of DC IL-2 production did not prevent DC priming of T lymphocytes. These results illustrate a new putative role for IL-4 on the regulation of the immune response and should help clarify the controversial reports on the effect of IL-4 on DCs.

Cyclosporine preconditions dendritic cells during differentiation and reduces IL-2 and IL-12 production following activation: a potential tolerogenic effect.

The mode of action of cyclosporine (CsA) has been ascribed to its capacity to inhibit IL-2 and IFNgamma production by T cells, two cytokines implicated in allograft rejection. Recently, it has been reported that upon activation, dendritic cells (DCs) exhibit transient production of IL-2, a property that appears to be related to their capacity to initiate immune responses. On the other hand, DCs can generate signals determining Th1/Th2 polarizing effects, an effect that can drastically influence the outcome of organ transplant. The purpose of the present study was to investigate the effect of CsA on cytokine production by immature and mature DCs. DC precursors from mouse bone marrow were induced to differentiate by incubation with GM-CSF for 5 days followed by activation with LPS for 4 hours. CsA was added at different times during this process. Our results show that when CsA is added during the differentiation period following activation with LPS, IL-2 and IL-12 secretion are significantly reduced without affecting the evolution of the DC. Conversely, CsA had no effect when added during the LPS activation period. These results show that CsA affects DCs before they receive the final activation stimulus, preconditioning them to antigen stimulation. This preconditioning of DCs by calcineurin-inhibiting drugs conceptually integrates the mode of action of CsA with the tolerogenic and T-cell polarization function ascribed to DCs. These results may be especially meaningful for the future design of immunosuppressive protocols.

Comparación farmacocinética de Sinemet y Grifoparkin (levodopa/carbidopa 250/25 mg) en pacientes con enfermedad de Parkinson avanzada: un estudio con dosis única / Pharmacokinetic comparison of Sinemet and Grifoparkin (levodopa/carbidopa 250/25 mg) in Parkinson s disease: a single dose study

BACKGROUND: There are doubts wether generic medications have the same bioavailability and efficacy compared with the original drugs developed by pharmaceutical companies with research capabilities. AIM: To compare the pharmacokinetics and clinical (motor) responses of Sinemet and Grifoparkin (generic carbidopa/levodopa 250/25 mg) in patients with advanced Parkinson's disease. PATIENTS AND METHODS: Patients were randomly assigned to Sinemet (15 patients 62 +/- 12 years old; mean disease duration 11 +/- 7 years) or Grifoparkin (15 patients, 64 +/- 11 years old; mean disease duration 12 +/- 4 years) groups. Medication and food were withheld 12 h before the study. Fifteen blood samples were collected (starting 9 AM) immediately before (sample 1, t = 0 min) and after (samples 2-15, t = 20-360 min) oral administration of a single dose of Sinemet or Grifoparkin, and plasmatic L-DOPA was quantified using HPLC with electrochemical detection. Additionally, each patient was clinically evaluated every 20 minutes, using the tapping test and the unified Parkinson's disease scale Hoehn & Yarh. RESULTS: Tmax (time at which the maximal L-DOPA concentration was reached) were 69 +/- 12 min and 64 +/- 11 min for Sinemet and Grifoparkin respectively (NS). Cmax (maximal L-DOPA concentration reached) was 3161 +/- 345 ng/ml for Sinemet and 3274 +/- 520 ng/ml for Grifoparkin (NS). The t1/2 (half life time), CL (clearance) and volume of distribution (Vd) values calculated were 159 +/- 32 min, 51.7 +/- 5.1 1/h and 3.6 +/- 1.2 l/kg for Sinemet and 161 +/- 48 min, 58.7 +/- 8 l/h and 3.0 +/- 0.7 l/kg for Grifoparkin (NS). UPDRS-III value for the best on state and for the worst off state were 23 +/- 11 and 50 +/- 19 for Sinemet and 20 +/- 7 and 46 +/- 13 for Grifoparkin respectively (NS). CONCLUSION: The results obtained showed that both drugs are bioequivalent in patients with advanced Parkinson's disease.

Experiencia preliminar en cirugías ambulatorias en el Servicio de Cirugía Pediátrica del Hospital Clínico Regional de Valdivia / Preliminar experience in ambulatory surgeries at Hospital Clínico Regional de Valdivia surgical paediatric service

Se presenta en forma preliminar la experiencia en cirugía ambulatoria de 300 pacientes en edades entre los 30 días y 15 años realizadas en el Servicio de Cirugía Infantil del Hospital Base de Valdivia, entre los años 1997 y octubre 2002, entendiendo por cirugía ambulatoria a la internación electiva, tratamiento y alta de pacientes durante el transcurso de un día hábil, excluyendo las cirugías menores efectuadas a pacientes occidentados o tratados en la Unidad de Emergencia. Se utilizaron criterios de selección como la edad (>30 días a <15 años), problemas anestésicos previsibles de acuerdo a la clasificación de estado físico de la Sociedad Americana de Anestesiología (status ASA I y II). Las patologías más frecuentemente resueltas mediante cirugía ambulatoria fueron las hernias inguinales, fimosis y testículos no descendidos. Las complicaciones no superaron el 1 por ciento y no obligaron a prolongar la estadía de los pacientes. La experiencia presentada sugiere continuar y extender esta práctica.

Infección por hongos en catéteres venosos centrales / Fungal infections in central venous catheters

Objetivo: presentar nuestra experiencia en el manejo de infecciones micóticas de catéteres venosos centrales (CVC) de larga duración en pacientes pediátricos con enfermedades hemato-oncológicas. Material y método: estudio retrospectivo entre enero de 1998 y diciembre de 1999 en el Servicio de Pediatría del Hospital Clínico Regional Valdivia. Se registraron 19 pacientes con CVC. Resultados: ocho casos presentaron infección del catéter, 5 por cándida. De estos últimos, todos consultaron por síndrome febril. El tiempo de permanencia del CVC fue en promedio de 208 días (rango 92 y 451 días). La tasa de infección de torrente sanguíneo por hongos asociado a 1000 días de uso de CVC Hickman es de 1,9 por ciento. Todos se manejaron con antifúngicos y retiro del catéter. Conclusiones: las cándidas constituyen la causa principal de infección de catéter en el presente estudio. El adecuado manejo de esta infección es el retiro precoz del catéter asociado a una terapia antifúngica oportuna