Involvement of the central nervous system in patients with dengue virus infection

The findings of a neurological evaluation in 85 patients with confirmed, acute, dengue virus infection are described. Signs of central nervous system involvement were present in IS patients (21.2%). The most frequent neurological symptom was mental confusion. The frequency of neurological involvement did not differ between patients with primary and secondary dengue infection, and the prevalence of central nervous system involvement in dengue fever and dengue hemorrhagic fever also did not differ significantly. The presence of CNS involvement did not influence the prognosis of dengue infection. Dengue viral CSF RNA was found in 7 of 13 patients submitted to a spinal tap, the CSF viral load being less than 1000 copies/ml. PCR was negative in serum samples obtained from three patients on the same day as the CSF samples, suggesting that the dengue virus actively enters the CNS and that the presence of the virus in the CNS does not result from passive crossing of the blood-brain barrier. (C) 2007 Elsevier B.V. All rights reserved.

Salvage of long-term central venous catheters during an outbreak of Pseudomonas putida and Stenotrophomonas maltophilia infections associated with contaminated heparin catheter-lock solution

objective. To describe the management of patients with long-term central venous catheters (CVCs) during an outbreak of infection due to Pseudomonas putida and Stenotrophomonas maltophilia associated with contaminated heparin catheter-lock solution. design. Descriptive study. setting. Private, 250-bed tertiary-care hospital. methods. In March 2003, we identified 2 febrile cancer patients with P. putida bacteremia. Over 2 days, 7 cases of bacteremia were identified; lots of syringes prefilled with heparin catheter-lock solution, supplied by a compounding pharmacy, were recalled and samples were cultured. More cases of bacteremia appeared during the following days, and any patient who had had a catheter lock infused with the suspect solution was asked to provide blood samples for culture, even if the patient was asymptomatic. Isolates that were recovered from culture were typed by pulsed-field gel electrophoresis. Antimicrobial salvage treatment of long-term CVCs was attempted. results. A total of 154 patients had had their catheter lock infused with solution from the lots that were suspected of being contaminated. Only 48 of these patients had CVCs. By day 7 of the outbreak, 18 of these patients had become symptomatic. Twenty-six of the remaining 30 asymptomatic patients then also provided blood samples for culture, 10 of whom developed fever shortly after samples were collected. Thirty-two patients were identified who had P. putida bacteremia; 9 also had infection due to S. maltophilia. Samples from 1 of the 3 lots of prefilled syringes in use at the time of the outbreak also grew P. putida on culture. Molecular typing identified 3 different clones of P. putida from patients and heparin catheter-lock solution, and 1 clone of S. maltophilia. A total of 27 patients received antimicrobial therapy regimens, some of which included decontamination of the catheter lock with anti- infective lock solution. Of 27 patients, 19 (70%) retained their long-term CVC during the 6-month follow-up period. conclusions. To our knowledge, this is one of the largest prospective experiences in the management of bloodstream infection associated with long-term CVCs. The infections were caused by gram-negative bacilli and were managed without catheter removal, with a high response rate. We emphasize the risks of using intravenous formulations of medications supplied by compounding pharmacies that produce large quantities of drugs.

Effects of bilateral adrenalectomy on systemic kainate-induced activation of the nucleus of the solitary tract. Regulation of blood pressure and local neurotransmitters

Glutamatergic transmission through metabotropic and ionotropic receptors, including kainate receptors, plays an important role in the nucleus of the solitary tract (NTS) functions. Glutamate system may interact with several other neurotransmitter systems which might also be influenced by steroid hormones. In the present study we analyzed the ability of systemic kainate to stimulate rat NTS neurons, which was evaluated by c-Fos as a marker of neuronal activation, and also to change the levels of NTS neurotransmitters such as GABA, NPY, CGRP, GAL, NT and NO by means of quantitative immunohistichemistry combined with image analysis. The analysis was also performed in adrenalectomized and kainate stimulated rats in order to evaluate a possible role of adrenal hormones on NTS neurotransmission. Male Wistar rats (3 month-old) were used in the present study. A group of 15 rats was submitted either to bilateral adrenalectomy or sham operation. Forty-eight hours after the surgeries, adrenalectomized rats received a single intraperitoneal injection of kainate (12 mg/kg) and the sham-operated rats were injected either with saline or kainate and sacrificed 8 hours later. The same experimental design was applied in a group of rats in order to register the arterial blood pressure. Systemic kainate decreased the basal values of mean arterial blood pressure (35%) and heart rate (22%) of sham-operated rats, reduction that were maintained in adrenalectomized rats. Kainate triggered a marked elevation of c-Fos positive neurons in the NTS which was 54% counteracted by adrenalectomy. The kainate activated NTS showed changes in the immunoreactive levels of GABA (143% of elevation) and NPY (36% of decrease), which were not modified by previous ablation of adrenal glands. Modulation in the levels of CGRP, GAL and NT immunoreactivities were only observed after kainate in the adrenalectomized rats. Treatments did not alter NOS labeling. It is possible that modulatory function among neurotransmitter systems in the NTS might be influenced by steroid hormones and the implications for central regulation of blood pressure or other visceral regulatory mechanisms control should be further investigated.

CENTRAL N-ACETYLCYSTEINE EFFECTS ON BAROREFLEX IN JUVENILE SPONTANEOUSLY HYPERTENSIVE RATS

In this study, we evaluated the acute effects of central NAC administration on baroreflex in juvenile SHR and Wistar Kyoto (WKY) rats. Male SHR and WKY rats (8 10 weeks old) were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. After basal MAP and HR recordings, the baroreflex was tested with a pressor dose of phenylephrine (PHE, 8 mu g/kg, bolus) and a depressor dose of sodium nitroprusside (SNP, 50 mu g/kg, bolus). Baroreflex was evaluated before, 5, 15, 30 and 60 minutes after NAC injection into the 4th V. Vehicle treatment did not change baroreflex responses in WKY and SHR. Central NAC slightly but significantly increased basal HR at 15 minutes and significantly reduced PHE-induced increase in MAP 30 and 60 minutes after NAC injection (p < 0.05) in WKY rats. In relation to SHR, NAC decreased HR range 15 and 30 minutes after its administration. In conclusion, acute NAC into the 4th V does not improve baroreflex in juvenile SHR.

Oral tolerance reduces Th17 cells as well as the overall inflammation in the central nervous system of EAE mice

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory immune response directed against myelin antigens of the central nervous system. In its murine model, EAE, Th17 cells play an important role in disease pathogenesis. These cells can induce blood-brain barrier disruption and CNS immune cells activation, due to the capacity to secrete high levels of IL-17 and IL-22 in an IL-6 + TGF-beta dependent manner. Thus, using the oral tolerance model, by which 200 mu g of MOG 35-55 is given orally to C57BL/6 mice prior to immunization, we showed that the percentage of Th17 cells as well as IL-17 secretion is reduced both in the periphery and also in the CNS of orally tolerated animals. Altogether, our data corroborates with the pathogenic role of IL-17 and IFN-gamma in EAE, as its reduction after oral tolerance, leads to an overall reduction of pro-inflammatory cytokines, such as IL-1 alpha, IL-6, IL-9, IL-12p70 and the chemokines MIP-1 beta, RANTES, Eotaxin and KC in the CNS. It is noteworthy that this was associated to an increase in IL-10 levels. Thus, our data clearly show that disease suppression after oral tolerance induction, correlates with reduction in target organ inflammation, that may be caused by a reduced Th1/Th17 response. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.

Corneal myofibroblast generation from bone marrow-derived cells

The purpose of this study was to determine whether bone marrow-derived cells can differentiate into myofibroblasts, as defined by alpha-smooth muscle actin (SMA) expression, that arise in the corneal stroma after irregular phototherapeutic keratectomy and whose presence within the cornea is associated with corneal stromal haze. C578L/6J-GFP chimeric mice were generated through bone marrow transplantation from donor mice that expressed enhanced green fluorescent protein (GFP) in a high proportion of their bone marrow-derived cells. Twenty-four GFP chimeric mice underwent haze-generating corneal epithelial scrape followed by irregular phototherapeutic keratectomy (PTK) with an excimer laser in one eye. Mice were euthanized at 2 weeks or 4 weeks after PTK and the treated and control contralateral eyes were removed and cryo-preserved for sectioning for immunocytochemistry. Double immunocytochemistry for GFP and myofibroblast marker alpha-smooth muscle actin (SMA) were performed and the number of SMA+GFP+, SMA+GFP, SMA-GFP+ and SMA GFP cells, as well as the number of DAPI+ cell nuclei, per 400x field of stroma was determined in the central, mid-peripheral and peri-limbal cornea. In this mouse model, there were no SMA+ cells and only a few GFP+ cells detected in unwounded control corneas. No SMA+ cells were detected in the stroma at two weeks after irregular PTK, even though there were numerous GFP+ cells present. At 4 weeks after irregular PTK, all corneas developed mild to moderately severe corneal haze. In each of the three regions of the corneas examined, there were on average more than 9x more SMA+GFP+ than SMA+GFP myofibroblasts. This difference was significant (p < 0.01). There were significantly more (p < 0.01) SMA GFP+ cells, which likely include inflammatory cells, than SMA+GFP+ or SMA+GFP cells, although SMA GFP cells represent the largest population of cells in the corneas. In this mouse model, the majority of myofibroblasts developed from bone marrow-derived cells. It is possible that all myofibroblasts in these animals developed from bone marrow-derived cells since mouse chimeras produced using this method had only 60-95% of bone marrow-derived cells that were GFP+ and it is not possible to achieve 100% chimerization. This model, therefore, cannot exclude the possibility of myofibroblasts also developed from keratocytes and/or corneal fibroblasts. (C) 2010 Elsevier Ltd. All rights reserved.

Cerebrospinal fluid levels of chemokines in HIV infected patients with and without opportunistic infection of the central nervous system

Chemokines are chemoattractant cytokines involved in the immune response of a wide variety of diseases. There are few studies assessing their role in opportunistic infections in HIV-infected patients. In this study, we measured CC and CXC chemokines in cerebrospinal fluid (CSF) samples obtained from 40 HIV-infected patients with or without opportunistic infections of the central nervous system (CNS). CSF samples were also analyzed for quantification of total protein, cell count and HIV-1 RNA. HIV+ patients with cryptococcal meningitis had higher levels of CCL2, CCL3, CCL5, CXCL9 and CXCL10 when compared to patients without opportunistic neurological infections. Furthermore, HIV+ patients with associated cryptococcal meningitis had higher levels of CCL3, CXCL9 and CXCL10 when compared to HIV+ patients with associated toxoplasmic encephalitis. CCL3 and CXCL9 levels were positively correlated with CSF HIV-1 RNA levels, CSF protein concentration, and CSF cell count. CXCL10 level was correlated with the CSF viral load and the CSF cell count and CCL5 level was correlated with the CSF cell count. In conclusion, the profile of chemokines in CSF of HIV patients may differ according to the modality of the presented opportunistic infection and according to other biological markers, such as viral load in CSF. These differences are probably related to different patterns of neuroinflammatory responses displayed by patients with different opportunistic neurological infections. (C) 2009 Elsevier B.V. All rights reserved.

ACCM/PALS haemodynamic support guidelines for paediatric septic shock: an outcomes comparison with and without monitoring central venous oxygen saturation

Introduction: The ACCM/PALS guidelines address early correction of paediatric septic shock using conventional measures. In the evolution of these recommendations, indirect measures of the balance between systemic oxygen delivery and demands using central venous or superior vena cava oxygen saturation ( ScvO(2) >= 70%) in a goal-directed approach have been added. However, while these additional goal-directed endpoints are based on evidence-based adult studies, the extrapolation to the paediatric patient remains unvalidated. Objective: The purpose of this study was to compare treatment according to ACCM/PALS guidelines, performed with and without ScvO(2) goal-directed therapy, on the morbidity and mortality rate of children with severe sepsis and septic shock. Design, participants and interventions: Children and adolescents with severe sepsis or fluid-refractory septic shock were randomly assigned to ACCM/PALS with or without ScvO(2) goal-directed resuscitation. Measurements: Twenty-eight-day mortality was the primary endpoint. Results: Of the 102 enrolled patients, 51 received ACCM/PALS with ScvO(2) goal-directed therapy and 51 received ACCM/PALS without ScvO(2) goal-directed therapy. ScvO(2) goal-directed therapy resulted in less mortality ( 28-day mortality 11.8% vs. 39.2%, p = 0.002), and fewer new organ dysfunctions ( p = 0.03). ScvO(2) goal-directed therapy resulted in more crystalloid ( 28 ( 20-40) vs. 5 ( 0-20) ml/kg, p < 0.0001), blood transfusion ( 45.1% vs. 15.7%, p = 0.002) and inotropic ( 29.4% vs. 7.8%, p = 0.01) support in the first 6 h. Conclusions: This study supports the current ACCM/PALS guidelines. Goal-directed therapy using the endpoint of a ScvO(2) = 70% has a significant and additive impact on the outcome of children and adolescents with septic shock.

Vestibular rehabilitation with biofeedback in patients with central imbalance

Central Nervous System disorders may cause important functional unbalance in the maintenance of balance and posture. There is no effective rehabilitation for these symptoms until now. Objective: The aim of this paper is to evaluate the use of tongue electrotactile stimulation on patients with central imbalance using BrainPort. Materials and Methods: This is a prospective case series study. We evaluated 8 patients with central imbalance, 6 men and 2 women, with mean age of 67.75 years. The patients were submitted to Computed Dynamic Posturography (CDP) and then received 18 sessions of electrotactile stimulation by BrainPort (R) device for 20 minutes, twice a day. Then they were submitted to a new CDP test and to a self-perception scale to assess symptom remission, partial improvement and no improvement at all. Results: 75% of the patients reported being more stable. There was no improvement in the balance control of the mass center in these patients. Conclusion: The patients were able to use the electrotactile stimulus to improve their balance control.

Toxoplasma gondii: The severity of toxoplasmic encephalitis in C57BL/6 mice is associated with increased ALCAM and VCAM-1 expression in the central nervous system and higher blood-brain barrier permeability

In order to investigate the differential ALCAM, ICAM-1 and VCAM-1 adhesion molecules mRNA expression and the blood-brain barrier (BBB) permeability in C57BL/6 and BALB/c mice in Toxoplasma gondii infection, animals were infected with ME-49 strain. It was observed higher ALCAM on day 9 and VCAM-1 expression on days 9 and 14 of infection in the central nervous system (CNS) of C57BL/6 compared to BALB/c mice. The expression of ICAM-1 was high and similar in the CNS of both lineages of infected mice. In addition, C57BL/6 presented higher BBB permeability and higher IFN-gamma and iNOS expression in the CNS compared to BALB/c mice. The CNS of C578L/6 mice presented elevated tissue pathology and parasitism. In conclusion, our data suggest that the higher adhesion molecules expression and higher BBB permeability contributed to the major inflammatory cell infiltration into the CNS of C57BL/6 mice that was not efficient to control the parasite. (C) 2010 Elsevier Inc. All rights reserved.

CCR2 receptor is essential to activate microbicidal mechanisms to control Toxoplasma gondii infection in the central nervous system

Chemokines comprise a structurally related family of cytokines that regulate leukocyte trafficking. Because infection with Toxoplasma gondii can induce an important inflammatory reaction that, if left uncontrolled, can lead to death, we investigated the role of the chemokine receptor CCR2 in T gondii infection. We orally infected CCR2(-/-) mice with five ME-49 T gondii cysts and monitored morbidity, survival, and immune response thereafter. The CCR2(-/-) mice displayed higher susceptibility to infection as all mice died on day 28 after infection. Despite similar Th1 responses, a more evident anti-inflammatory response was induced in the peripheral organs of CCR2(-/-) mice compared with wild-type C57BL/6 mice. Additionally, CCR2-/- mice presented greater parasitism and a milder inflammatory reaction in their peripheral organs with lesser CD4(+) and MAC-1(+) and greater CD8(+) cell migration. The parasite load decreased in these organs in CCR2(-/-) mice but remained uncontrolled in the central nervous system. Additionally, we observed down-regulated inducible nitric oxide synthase expression in peripheral organs from CCR2(-/-) mice that was associated with a small nitric oxide production by spleen macrophages. In conclusion, in the absence of CCR2, another mechanism is activated to control tissue parasitism in peripheral organs. Nevertheless, CCR2 is essential for the activation of microbicidal mediators that control T gondii replication in the central nervous system.

GABA(A) receptor blockade in dorsomedial and ventromedial nuclei of the hypothalamus evokes panic-like elaborated defensive behaviour followed by innate fear-induced antinociception

Dysfunction in the hypothalamic GABAergic system has been implicated in panic syndrome in humans. Furthermore, several studies have implicated the hypothalamus in the elaboration of pain modulation. Panic-prone states are able to be experimentally induced in laboratory animals to study this phenomenon. The aim of the present work was to investigate the involvement of medial hypothalamic nuclei in the organization of panic-like behaviour and the innate fear-induced oscillations of nociceptive thresholds. The blockade of GABA(A) receptors in the neuronal substrates of the ventromedial. or dorsomedial hypothalamus was followed by elaborated defensive panic-like reactions. Moreover, innate fear-induced antinociception was consistently elicited after the escape behaviour. The escape responses organized by the dorsomedial and ventromedial hypothalamic nuclei were characteristically more elaborated, and a remarkable exploratory behaviour was recorded during GABA(A) receptor blockade in the medial hypothalamus. The motor characteristic of the elaborated defensive escape behaviour and the patterns of defensive alertness and defensive immobility induced by microinjection of the bicuculline either into the dorsomedial. or into the ventromedial hypothalamus were very similar. This was followed by the same pattern of innate fear-induced antinociceptive response that lasted approximately 40 min after the elaborated defensive escape reaction in both cases. These findings suggest that dysfunction of the GABA-mediated neuronal system in the medial hypothalamus causes panic-like responses in laboratory animals, and that the elaborated escape behaviour organized in both dorsomedial and ventromedial hypothalamic nuclei are followed by significant innate-fear-induced antinociception. Our findings indicate that the GABA(A) receptor of dorsomedial and ventromedial hypothalamic nuclei are critically involved in the modulation of panic-like behaviour. (C) 2009 Elsevier B.V. All rights reserved.

Central but not systemic inhibition of inducible nitric oxide synthase modulates oxytocin release during endotoxemic shock

Previous studies have shown that immunological challenges as lipopolysaccharide (LPS) administration increases plasma oxytocin (OT) concentration. Nitric oxide (NO), a free radical gas directly related to the immune system has been implicated in the central modulation of neuroendocrine adaptive responses to immunological stress. This study aimed to test the hypothesis that the NO pathway participates in the control of OT release induced by LPS injection. For this purpose, adult male Wistar rats received bolus intravenous (i.v.) injection of LPS, preceded or not by iv. or intracerebroventricular (i.c.v.) injections of aminoguanidine (AG), a selective inducible nitric oxide synthase (iNOS) inhibitor. Rats were decapitated after 2, 4 and 6 h of treatment, for measurement of OT by radioimmunoassay. In a separate set of experiments, mean arterial pressure (MAP) and heart rate (HR) were measured every 15 min over 6 h, using a polygraph. These studies revealed that LPS reduced MAP and increased HR at 4 and 6 h post-injection. LPS significantly increased plasma OT concentration at 2 and 4 h post-injection. Pre-treatment with i.c.v. AG further increased plasma OT concentration and attenuated the LPS-induced decrease in MAP, however, i.v. AG failed to show similar effects. Thus, iNOS pathway may activate a central inhibitory control mechanism that attenuates OT secretion during endotoxemic shock. (C) 2009 Elsevier Inc. All rights reserved.

Glomerular Nucleus of the Weakly Electric Fish, Gymnotus sp.: Cytoarchitecture, Histochemistry, and Fiber Connections-Insights from Neuroanatomy to Evolution and Behavior

The present study provides a detailed description of morphological and hodological aspects of the glomerular nucleus in the weakly electric fish Gymnotus sp., and explores the evolutionary and functional implications flowing from this analysis. The glomerular nucleus of Gymnotus shows numerous morphological similarities with the glomerular nucleus of percomorph fish, although cytoarchitectonically simpler. In addition, congruence of the histochemical acetylcholinesterase (AChE) distribution with cytoarchitectonic data suggests that the glomerular nucleus, together with the ventromedial cell group of the medial subdivision of the preglomerular complex (PGm-vmc) rostrally, and the subglomerular nucleus (as identified by Maler et al. [1991] J Chem Neuroanat 4:1-38) caudally, may form a distinct longitudinally organized glomerular complex. Our results show that an important source of sensory afferents to the glomerular nucleus originates in the pretectal and electrosensorius nuclei. The glomerular nucleus in turn projects to the hypothalamus (inferior lobe and anterior hypothalamus), to the anterior tuberal nucleus, and to the medial region of the preglomerular nucleus (PGm). These data suggest that visual and electrosensory information reach the glomerular nucleus and are relayed to the hypothalamus and, via PGm, to the pallium. Such connections are similar to those of the glomerular nucleus in percomorphs and the posterior pretectal nucleus in osteoglossomorph, esocids, and salmonids, where they comprise one component of a visual processing pathway. In Gymnotiform fish, however, the pretectal region that projects to the glomerular nucleus is dominated by electrosensory input (visual input is minor), which is consistent with the dominant role of electroreception in these fish. J. Comp. Neurol. 519:1658-1676, 2011. (c) 2011 Wiley-Liss, Inc.

Prostaglandin mediates endotoxaemia-induced hypophagia by activation of pro-opiomelanocortin and corticotrophin-releasing factor neurons in rats

Corticotrophin-releasing factor (CRF) and alpha-melanocyte-stimulating hormone (alpha-MSH), both of which are synthesized by hypothalamic neurons, play an essential role in the control of energy homeostasis. Neuroendocrine and behavioural responses induced by lipopolyssacharide (LPS) have been shown to involve prostaglandin-mediated pathways. This study investigated the effects of prostaglandin on CRF and alpha-MSH neuronal activities in LPS-induced anorexia. Male Wistar rats were pretreated with indomethacin (10 mg kg(-1); i.p.) or vehicle; 15 min later they received LPS (500 mu g kg(-1); i.p.) or saline injection. Food intake, hormone responses and Fos-CRF and Fos-alpha-MSH immunoreactivity in the paraventricular and arcuate nuclei, respectively, were evaluated. In comparison with saline treatment, LPS administration induced lower food intake and increased plasma ACTH and corticosterone levels, as well as an increase in Fos-CRF and Fos-alpha-MSH double-labelled neurons in vehicle-pretreated rats. In contrast, indomethacin treatment partly reversed the hypophagic effect, blunted the hormonal increase and blocked the Fos-CRF and Fos-alpha-MSH hypothalamic double labelling increase in response to the LPS stimulus. These data demonstrate that the activation of pro-opiomelanocortin and CRF hypothalamic neurons following LPS administration is at least partly mediated by the prostaglandin pathway and is likely to be involved in the modulation of feeding behaviour during endotoxaemia.