Identification of the NRF2 transcriptional network as a therapeutic target for trigeminal neuropathic pain.

Trigeminal neuralgia, historically dubbed the "suicide disease," is an exceedingly painful neurologic condition characterized by sudden episodes of intense facial pain. Unfortunately, the only U.S. Food and Drug Administration (FDA)-approved medication for trigeminal neuralgia carries substantial side effects, with many patients requiring surgery. Here, we identify the NRF2 transcriptional network as a potential therapeutic target. We report that cerebrospinal fluid from patients with trigeminal neuralgia accumulates reactive oxygen species, several of which directly activate the pain-transducing channel TRPA1. Similar to our patient cohort, a mouse model of trigeminal neuropathic pain also exhibits notable oxidative stress. We discover that stimulating the NRF2 antioxidant transcriptional network is as analgesic as inhibiting TRPA1, in part by reversing the underlying oxidative stress. Using a transcriptome-guided drug discovery strategy, we identify two NRF2 network modulators as potential treatments. One of these candidates, exemestane, is already FDA-approved and may thus be a promising alternative treatment for trigeminal neuropathic pain.

ZikaPLAN: addressing the knowledge gaps and working towards a research preparedness network in the Americas.

Zika Preparedness Latin American Network (ZikaPLAN) is a research consortium funded by the European Commission to address the research gaps in combating Zika and to establish a sustainable network with research capacity building in the Americas. Here we present a report on ZikaPLAN`s mid-term achievements since its initiation in October 2016 to June 2019, illustrating the research objectives of the 15 work packages ranging from virology, diagnostics, entomology and vector control, modelling to clinical cohort studies in pregnant women and neonates, as well as studies on the neurological complications of Zika infections in adolescents and adults. For example, the Neuroviruses Emerging in the Americas Study (NEAS) has set up more than 10 clinical sites in Colombia. Through the Butantan Phase 3 dengue vaccine trial, we have access to samples of 17,000 subjects in 14 different geographic locations in Brazil. To address the lack of access to clinical samples for diagnostic evaluation, ZikaPLAN set up a network of quality sites with access to well-characterized clinical specimens and capacity for independent evaluations. The International Committee for Congenital Anomaly Surveillance Tools was formed with global representation from regional networks conducting birth defects surveillance. We have collated a comprehensive inventory of resources and tools for birth defects surveillance, and developed an App for low resource regions facilitating the coding and description of all major externally visible congenital anomalies including congenital Zika syndrome. Research Capacity Network (REDe) is a shared and open resource centre where researchers and health workers can access tools, resources and support, enabling better and more research in the region. Addressing the gap in research capacity in LMICs is pivotal in ensuring broad-based systems to be prepared for the next outbreak. Our shared and open research space through REDe will be used to maximize the transfer of research into practice by summarizing the research output and by hosting the tools, resources, guidance and recommendations generated by these studies. Leveraging on the research from this consortium, we are working towards a research preparedness network.

ZikaPLAN: addressing the knowledge gaps and working towards a research preparedness network in the Americas

Zika Preparedness Latin American Network (ZikaPLAN) is a research consortium funded by the European Commission to address the research gaps in combating Zika and to establish a sustainable network with research capacity building in the Americas. Here we present a report on ZikaPLAN's mid-term achievements since its initiation in October 2016 to June 2019, illustrating the research objectives of the 15 work packages ranging from virology, diagnostics, entomology and vector control, modelling to clinical cohort studies in pregnant women and neonates, as well as studies on the neurological complications of Zika infections in adolescents and adults. For example, the Neuroviruses Emerging in the Americas Study (NEAS) has set up more than 10 clinical sites in Colombia. Through the Butantan Phase 3 dengue vaccine trial, we have access to samples of 17,000 subjects in 14 different geographic locations in Brazil. To address the lack of access to clinical samples for diagnostic evaluation, ZikaPLAN set up a network of quality sites with access to well-characterized clinical specimens and capacity for independent evaluations. The International Committee for Congenital Anomaly Surveillance Tools was formed with global representation from regional networks conducting birth defects surveillance. We have collated a comprehensive inventory of resources and tools for birth defects surveillance, and developed an App for low resource regions facilitating the coding and description of all major externally visible congenital anomalies including congenital Zika syndrome. Research Capacity Network (REDe) is a shared and open resource centre where researchers and health workers can access tools, resources and support, enabling better and more research in the region. Addressing the gap in research capacity in LMICs is pivotal in ensuring broad-based systems to be prepared for the next outbreak. Our shared and open research space through REDe will be used to maximize the transfer of research into practice by summarizing the research output and by hosting the tools, resources, guidance and recommendations generated by these studies. Leveraging on the research from this consortium, we are working towards a research preparedness network.

ZikaPLAN: addressing the knowledge gaps and working towards a research preparedness network in the Americas

Zika Preparedness Latin American Network (ZikaPLAN) is a research consortium funded by the European Commission to address the research gaps in combating Zika and to establish a sustainable network with research capacity building in the Americas. Here we present a report on ZikaPLAN's mid-term achievements since its initiation in October 2016 to June 2019, illustrating the research objectives of the 15 work packages ranging from virology, diagnostics, entomology and vector control, modelling to clinical cohort studies in pregnant women and neonates, as well as studies on the neurological complications of Zika infections in adolescents and adults. For example, the Neuroviruses Emerging in the Americas Study (NEAS) has set up more than 10 clinical sites in Colombia. Through the Butantan Phase 3 dengue vaccine trial, we have access to samples of 17,000 subjects in 14 different geographic locations in Brazil. To address the lack of access to clinical samples for diagnostic evaluation, ZikaPLAN set up a network of quality sites with access to well-characterized clinical specimens and capacity for independent evaluations. The International Committee for Congenital Anomaly Surveillance Tools was formed with global representation from regional networks conducting birth defects surveillance. We have collated a comprehensive inventory of resources and tools for birth defects surveillance, and developed an App for low resource regions facilitating the coding and description of all major externally visible congenital anomalies including congenital Zika syndrome. Research Capacity Network (REDe) is a shared and open resource centre where researchers and health workers can access tools, resources and support, enabling better and more research in the region. Addressing the gap in research capacity in LMICs is pivotal in ensuring broad-based systems to be prepared for the next outbreak. Our shared and open research space through REDe will be used to maximize the transfer of research into practice by summarizing the research output and by hosting the tools, resources, guidance and recommendations generated by these studies. Leveraging on the research from this consortium, we are working towards a research preparedness network.

Loss of Smooth Muscle α-Actin Leads to NF-κB-Dependent Increased Sensitivity to Angiotensin II in Smooth Muscle Cells and Aortic Enlargement.

RATIONALE: Mutations in ACTA2, encoding the smooth muscle isoform of α-actin, cause thoracic aortic aneurysms, acute aortic dissections, and occlusive vascular diseases. OBJECTIVE: We sought to identify the mechanism by which loss of smooth muscle α-actin causes aortic disease. METHODS AND RESULTS: Acta2-/- mice have an increased number of elastic lamellae in the ascending aorta and progressive aortic root dilation as assessed by echocardiography that can be attenuated by treatment with losartan, an angiotensin II (AngII) type 1 receptor blocker. AngII levels are not increased in Acta2-/- aortas or kidneys. Aortic tissue and explanted smooth muscle cells from Acta2-/- aortas show increased production of reactive oxygen species and increased basal nuclear factor κB signaling, leading to an increase in the expression of the AngII receptor type I a and activation of signaling at 100-fold lower levels of AngII in the mutant compared with wild-type cells. Furthermore, disruption of smooth muscle α-actin filaments in wild-type smooth muscle cells by various mechanisms activates nuclear factor κB signaling and increases expression of AngII receptor type I a. CONCLUSIONS: These findings reveal that disruption of smooth muscle α-actin filaments in smooth muscle cells increases reactive oxygen species levels, activates nuclear factor κB signaling, and increases AngII receptor type I a expression, thus potentiating AngII signaling in vascular smooth muscle cells without an increase in the exogenous levels of AngII.

Ultra High-Resolution In vivo Computed Tomography Imaging of Mouse Cerebrovasculature Using a Long Circulating Blood Pool Contrast Agent.

Abnormalities in the cerebrovascular system play a central role in many neurologic diseases. The on-going expansion of rodent models of human cerebrovascular diseases and the need to use these models to understand disease progression and treatment has amplified the need for reproducible non-invasive imaging methods for high-resolution visualization of the complete cerebral vasculature. In this study, we present methods for in vivo high-resolution (19 µm isotropic) computed tomography imaging of complete mouse brain vasculature. This technique enabled 3D visualization of large cerebrovascular networks, including the Circle of Willis. Blood vessels as small as 40 µm were clearly delineated. ACTA2 mutations in humans cause cerebrovascular defects, including abnormally straightened arteries and a moyamoya-like arteriopathy characterized by bilateral narrowing of the internal carotid artery and stenosis of many large arteries. In vivo imaging studies performed in a mouse model of Acta2 mutations demonstrated the utility of this method for studying vascular morphometric changes that are practically impossible to identify using current histological methods. Specifically, the technique demonstrated changes in the width of the Circle of Willis, straightening of cerebral arteries and arterial stenoses. We believe the use of imaging methods described here will contribute substantially to the study of rodent cerebrovasculature.

Steroid-responsive intracranial germinoma presenting as Holmes' tremor: importance of a tissue diagnosis.

Holmes' tremor (rubral or midbrain outflow tremor) refers to a hyperkinetic movement disorder characterized by mild resting and more severe postural and action tremor often with associated brainstem symptoms, dystonia and cerebellar deficits. This syndrome should prompt lesional evaluation with neuroimaging focused on the dorsal midbrain, cerebellar outflow tracts, and thalamus. Herein we report a 26-year-old previously healthy male who presented with 4 years of progressive horizontal diplopia, right Parinaud syndrome, and appendicular ataxia. Neuroimaging revealed a right dorsal midbrain enhancing lesion which completely resolved with intravenous methylprednisolone prompting a diagnosis of neuroinflammatory syndrome. Subsequent clinical and radiographic evaluations, however, revealed steadily progressive left dorsal midbrain syndrome with an expansile enhancing lesion which culminated 4 years from symptom onset with a right upper extremity low-frequency rest, postural and action tremor, ataxic dysarthria, and mild right dystonia with dysdiadochokinesia. Uncomplicated brainstem biopsy confirmed intracranial germinoma and the patient underwent definitive radiation therapy with dramatic radiographic response and partial clinical improvement. This case, which to our knowledge is only the second report of intracranial germinoma presenting as Holmes' tremor, highlights the critical importance of definitive tissue diagnosis in the evaluation of lesional brainstem pathology presenting as Holmes' tremor. Steroid responsiveness can be seen in non-inflammatory pathology including intracranial germinoma. Prompt evaluation and appropriate treatment are important as Holmes' tremor responds poorly to symptomatic therapies and response to radiation therapy is favorable for germinomas.

A selective thyroid hormone ß receptor agonist enhances human and rodent oligodendrocyte differentiation.

Nerve conduction within the mammalian central nervous system is made efficient by oligodendrocyte-derived myelin. Historically, thyroid hormones have a well described role in regulating oligodendrocyte differentiation and myelination during development; however, it remains unclear which thyroid hormone receptors are required to drive these effects. This is a question with clinical relevance since nonspecific thyroid receptor stimulation can produce deleterious side-effects. Here we report that GC-1, a thyromimetic with selective thyroid receptor ß action and a potentially limited side-effect profile, promotes in vitro oligodendrogenesis from both rodent and human oligodendrocyte progenitor cells. In addition, we used in vivo genetic fate tracing of oligodendrocyte progenitor cells via PDGFαR-CreER;Rosa26-eYFP double-transgenic mice to examine the effect of GC-1 on cellular fate and find that treatment with GC-1 during developmental myelination promotes oligodendrogenesis within the corpus callosum, occipital cortex and optic nerve. GC-1 was also observed to enhance the expression of the myelin proteins MBP, CNP and MAG within the same regions. These results indicate that a ß receptor selective thyromimetic can enhance oligodendrocyte differentiation in vitro and during developmental myelination in vivo and warrants further study as a therapeutic agent for demyelinating models.

Aortic remodeling after transverse aortic constriction in mice is attenuated with AT1 receptor blockade.

OBJECTIVE: Although hypertension is the most common risk factor for thoracic aortic diseases, it is not understood how increased pressures on the ascending aorta lead to aortic aneurysms. We investigated the role of angiotensin II type 1 receptor activation in ascending aortic remodeling in response to increased biomechanical forces using a transverse aortic constriction (TAC) mouse model. APPROACH AND RESULTS: Two weeks after TAC, the increased biomechanical pressures led to ascending aortic dilatation and thickening of the medial and adventitial layers of the aorta. There was significant adventitial hyperplasia and inflammatory responses in TAC ascending aortas were accompanied by increased adventitial collagen, elevated inflammatory and proliferative markers, and increased cell density attributable to accumulation of myofibroblasts and macrophages. Treatment with losartan significantly blocked TAC-induced vascular inflammation and macrophage accumulation. However, losartan only partially prevented TAC-induced adventitial hyperplasia, collagen accumulation, and ascending aortic dilatation. Increased Tgfb2 expression and phosphorylated-Smad2 staining in the medial layer of TAC ascending aortas were effectively blocked with losartan. In contrast, the increased Tgfb1 expression and adventitial phospho-Smad2 staining were only partially attenuated by losartan. In addition, losartan significantly blocked extracellular signal-regulated kinase activation and reactive oxygen species production in the TAC ascending aorta. CONCLUSIONS: Inhibition of the angiotensin II type 1 receptor using losartan significantly attenuated the vascular remodeling associated with TAC but did not completely block the increased transforming growth factor-ß1 expression, adventitial Smad2 signaling, and collagen accumulation. These results help to delineate the aortic transforming growth factor-ß signaling that is dependent and independent of the angiotensin II type 1 receptor after TAC.

Smooth muscle hyperplasia due to loss of smooth muscle α-actin is driven by activation of focal adhesion kinase, altered p53 localization and increased levels of platelet-derived growth factor receptor-ß.

Mutations in ACTA2, encoding the smooth muscle cell (SMC)-specific isoform of α-actin (α-SMA), cause thoracic aortic aneurysms and dissections and occlusive vascular diseases, including early onset coronary artery disease and stroke. We have shown that occlusive arterial lesions in patients with heterozygous ACTA2 missense mutations show increased numbers of medial or neointimal SMCs. The contribution of SMC hyperplasia to these vascular diseases and the pathways responsible for linking disruption of α-SMA filaments to hyperplasia are unknown. Here, we show that the loss of Acta2 in mice recapitulates the SMC hyperplasia observed in ACTA2 mutant SMCs and determine the cellular pathways responsible for SMC hyperplasia. Acta2(-/-) mice showed increased neointimal formation following vascular injury in vivo, and SMCs explanted from these mice demonstrated increased proliferation and migration. Loss of α-SMA induced hyperplasia through focal adhesion (FA) rearrangement, FA kinase activation, re-localization of p53 from the nucleus to the cytoplasm and increased expression and ligand-independent activation of platelet-derived growth factor receptor beta (Pdgfr-ß). Disruption of α-SMA in wild-type SMCs also induced similar cellular changes. Imatinib mesylate inhibited Pdgfr-ß activation and Acta2(-/-) SMC proliferation in vitro and neointimal formation with vascular injury in vivo. Loss of α-SMA leads to SMC hyperplasia in vivo and in vitro through a mechanism involving FAK, p53 and Pdgfr-ß, supporting the hypothesis that SMC hyperplasia contributes to occlusive lesions in patients with ACTA2 missense mutations.

Granzyme B-induced neurotoxicity is mediated via activation of PAR-1 receptor and Kv1.3 channel.

Increasing evidence supports a critical role of T cells in neurodegeneration associated with acute and subacute brain inflammatory disorders. Granzyme B (GrB), released by activated T cells, is a cytotoxic proteinase which may induce perforin-independent neurotoxicity. Here, we studied the mechanism of perforin-independent GrB toxicity by treating primary cultured human neuronal cells with recombinant GrB. GrBactivated the protease-activated receptor (PAR)-1 receptor on the neuronal cell surface leading to decreased intracellular cyclic AMP levels. This was followed by increased expression and translocation of the voltage gated potassium channel, Kv1.3 to the neuronal cell membrane. Similar expression of Kv1.3 was also seen in neurons of the cerebral cortex adjacent to active inflammatory lesions in patients with multiple sclerosis. Kv1.3 expression was followed by activation of Notch-1 resulting in neurotoxicity. Blocking PAR-1, Kv1.3 or Notch-1 activation using specific pharmacological inhibitors or siRNAs prevented GrB-induced neurotoxicity. Furthermore, clofazimine protected against GrB-induced neurotoxicity in rat hippocampus, in vivo. These observations indicate that GrB released from T cells induced neurotoxicity by interacting with the membrane bound Gi-coupled PAR-1 receptor and subsequently activated Kv1.3 and Notch-1. These pathways provide novel targets to treat T cell-mediated neuroinflammatory disorders. Kv1.3 is of particular interest since it is expressed on the cell surface, only under pathological circumstances, and early in the cascade of events making it an attractive therapeutic target.

Exome sequencing identifies SMAD3 mutations as a cause of familial thoracic aortic aneurysm and dissection with intracranial and other arterial aneurysms.

RATIONALE: Thoracic aortic aneurysms leading to acute aortic dissections (TAAD) can be inherited in families in an autosomal dominant manner. As part of the spectrum of clinical heterogeneity of familial TAAD, we recently described families with multiple members that had TAAD and intracranial aneurysms or TAAD and intracranial and abdominal aortic aneurysms inherited in an autosomal dominant manner. OBJECTIVE: To identify the causative mutation in a large family with autosomal dominant inheritance of TAAD with intracranial and abdominal aortic aneurysms by performing exome sequencing of 2 distantly related individuals with TAAD and identifying shared rare variants. METHODS AND RESULTS: A novel frame shift mutation, p. N218fs (c.652delA), was identified in the SMAD3 gene and segregated with the vascular diseases in this family with a logarithm of odds score of 2.52. Sequencing of 181 probands with familial TAAD identified 3 additional SMAD3 mutations in 4 families, p.R279K (c.836G>A), p.E239K (c.715G>A), and p.A112V (c.235C>T), resulting in a combined logarithm of odds score of 5.21. These 4 mutations were notably absent in 2300 control exomes. SMAD3 mutations were recently described in patients with aneurysms osteoarthritis syndrome and some of the features of this syndrome were identified in individuals in our cohort, but these features were notably absent in many SMAD3 mutation carriers. CONCLUSIONS: SMAD3 mutations are responsible for 2% of familial TAAD. Mutations are found in families with TAAD alone, along with families with TAAD, intracranial aneurysms, abdominal aortic and bilateral iliac aneurysms segregating in an autosomal dominant manner.

Paucity of skeletal manifestations in Hispanic families with FBN1 mutations.

Marfan syndrome (MFS) is an autosomal dominant condition with pleiotropic manifestations involving the skeletal, ocular, and cardiovascular systems. The diagnosis is based primarily on clinical involvement of these and other systems, referred to as the Ghent criteria. We have identified three Hispanic families from Mexico with cardiovascular and ocular manifestations due to novel FBN1 mutations but with paucity of skeletal features. The largest family, hMFS001, had a frameshift mutation in exon 24 (3075delC) identified as the cause of aortic disease in the family. Assessment of eight affected adults revealed no major skeletal manifestation of MFS. Family hMFS002 had a missense mutation (R1530C) in exon 37. Four members fulfilled the criteria for ocular and cardiovascular phenotype but lacked skeletal manifestations. Family hMFS003 had two consecutive missense FBN1 mutations (C515W and R516G) in exon 12. Eight members fulfilled the ocular criteria for MFS and two members had major cardiovascular manifestations, however none of them met criteria for skeletal system. These data suggest that individuals of Hispanic descent with FBN1 mutations may not manifest skeletal features of the MFS to the same extent as Caucasians. We recommend that echocardiogram, ocular examination and FBN1 molecular testing be considered for any patients with possible MFS even in the absence of skeletal features, including Hispanic patients.

Antineuronal antibodies in OCD: comparisons in children with OCD-only, OCD+chronic tics and OCD+PANDAS.

Autoimmunity associated with a streptococcal infection has been proposed as a pathogenic mechanism for obsessive-compulsive disorder (OCD) in children. Antibrain antibody profiles were compared in children with OCD-only (n = 13; 14.1 +/- 3.1 years), OCD+PANDAS (n = 20; 11.3 +/- 1.5 years), OCD+Chronic Tic Disorder (n = 23; 13.4 +/- 3.5 years), and controls (n = 29; 12.4 +/- 2.4 years) using ELISA (orbitofrontal (OFC) and dorsolateral prefrontal cortex (DLPFC), caudate (CD), cingulate gyrus (CG)), immunoblotting (four regions plus putative antigens), and immunohistochemistry. ELISA and immunohistochemistry showed no differences among groups. Immunoblot showed that a greater percentage of individuals in the OCD+PANDAS cohort had reactive bands at 27 kDa (CD, CG, DLPFC), 36 kDa (CD), and 100 kDa (CD, OFC) and increased peak height at 67 kDa (all regions). Immunoblotting studies using the putative antigens (pyruvate kinase M1, aldolase C, alpha- and gamma-enolase) did not differ among groups. ASO titers were similar in all groups and did not correlate with immunoassays. It remains controversial whether childhood OCD is associated with autoimmune mechanisms.

Serum autoantibodies measured by immunofluorescence confirm a failure to differentiate PANDAS and Tourette syndrome from controls.

PANDAS and some cases of Tourette syndrome (TS) have been proposed to be post-streptococcal movement disorders in which antibodies produced against group A beta-hemolytic streptococcus cross react against brain epitopes. Attempts to identify disease specific anti-striatal antibodies in the serum of affected patients have focused on the use of Western immunoblotting and ELISA methodologies. In this study, immunohistochemical techniques were used to identify serum anti-striatal antibody reactivity. In positive samples, double staining with anti-GFAP (glial) and anti-MAP2 (neuronal) was used to establish localization of the immunofluorescence. No significant differences in immunofluorescence or localization were identified in patients with PANDAS (n=30) and TS (n=30) as compared to controls (n=30). IF reactivity did not correlate with tic severity or elevated titers of antistreptococcal antibodies. Further comparisons showed no correlation between autoreactivity determined by immunofluorescence and the presence of previously measured immunoblot reactivity against human caudate or putative antigens (pyruvate kinase M1 and aldolase C). These results confirm an inability to distinguish patient populations by antibody measurements and raise further concerns about the presence of an autoimmune mechanism in PANDAS and TS.

Infecciones en terapia intensiva: infecciones nosocomiales en UTI / Infections in intensive therapy: nosocomial infections in ICU: part II: nosocomial pneumonia

Las infecciones nosocomiales respiratorias representan hasta un 70 por ciento de las infecciones nosocomiales y el 50-70 por ciento de la mortalidad en las unidades de cuidados intensivos, por lo que constituyen un verdadero problema a pesar de los grandes esfuerzos en la investigación de nuevos antibióticos y técnicas novedosas para el diagnóstico. Existen numerosos factores predisponentes inherentes al paciente y asociadas a la ventilación mecánica y el ambiente de la UCI. Los mecanismos patógenos son diversos, destacando entre ellos la aspiración del contenido de la boca hacia las vías aéreas superiores. Los gérmenes más frecuentes asociados con neumonía nosocomial son los Gram-negativos, y entre ellos las Pseudomonas, Proteus, E.coli, y Haemophilus, y de los Gram-positivos destaca el Staphylococcus. Dentro de las complicaciones, la más frecuente es el derrame paraneumónico. La terapéutica inicial se instituye en base a la coloración de Gram, mientras se obtiene el resultado de los cultivos y antibiograma. En la actualidad existen diversas medidas preventivas con el fin de evitar la colonización, aspiración y deterioro de los diferentes sistemas de defensa del huesped.

Infecciones en terapia intensiva: infecciones nosocomiales en UTI / Infections in critical care: nosocomial infections in UTI

Bacteremia nosocomial, se define como el crecimiento de un microorganismo en un cultivo tomado con las medidas de asepsia y antisepsia adecuadas en un paciente sin signos o síntomas de infección o el crecimiento de nuevos gérmenes en un cultivo previamente positivo. La bacteremia primaria es aquella producida sin ningún foco séptico a distancia, mientras que la secundaria es aquella donde si existe un foco séptico primario: adbomen, pulmones, etc. Existen factores predisponentes para la bacteremia nosocomial relacionada con catéter, entre los cuales están: métodos y sitio de inserción, material del catéter, tipo de catéter y duración del catéter en el sitio. Los gérmenes más frecuentes asociados a bacteremis nosocomiales asociadas a catéter son: cocos Gram (+), S. coagulosa (-) en 25 por ciento, S. aureus con 15 por ciento, y el Enterococcus spp; los Gram (-) más frecuente encontrados: E. coli, Enterobacter spp; y la levadura Candida albicans, con 5 a 8 por ciento para cada uno de ellos. La infección nosocomial relacionada con líneas corresponde entre el 25 y el 30 por ciento del total de las bacteremias nosocomiales. Existen diversas medidas preventivas tales como el lavado de las manos, preparación del sitio de la inserción, cambio de curas, catéteres, equipos de infusión, transductores y soluciones de infusión, así como el uso de catéteres con "cuffs" de colágeno, y la realización de la técnica de tunelización, con el fin de disminuir la frecuencia de estas infecciones