Cerebral Ventriculitis

Deciphering Tuberculous Meningitis: From Clinical Challenges to Novel Models and Pathogenic Pathways

During and after the COVID-19 pandemic, Tuberculosis (TB) has reestablished with higher figures due to interruptions in the Directly Observed Treatment Short course (DOTS) despite underreporting. The rising consequences would have extended to extra-pulmonary forms of TB as well, including Tuberculous Meningitis (TBM). Considering the fact that TBM is the most dangerous and worst form of TB, we found the need to scan the literature to highlight various aspects of TBM. Epidemiology of TBM is proportionally less frightening, but the consequent mortalities and morbidities are more alarming than pulmonary TB. Here, we address critical research gaps in Tuberculous Meningitis that warrant further investigations. The highlighted aspects encompass a comprehensive understanding of TBM's clinical presentation and improved diagnostic tools for timely detection, the exploration of innovative chemotherapies and surgical interventions, the unraveling of the role of the blood-brain barrier in disease onset, investigating of the contributions of various brain cells to TBM development, deciphering the complex inflammatory response, exploring the involvement of Matrix Metalloproteinases in tissue damage, delving into host-pathogen genetics influencing susceptibility, utilizing robust in-vivo and in-vitro models for mechanistic insights, and more importantly between TBM and SARS-COVID-19 are discussed. Addressing these gaps will substantially advance our understanding of TBM's complex pathogenesis, contributing to more effective diagnostic, therapeutic, and preventive strategies against this debilitating disease.

The Updated Role of the Blood Brain Barrier in Subarachnoid Hemorrhage: From Basic and Clinical Studies

Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke associated with high mortality and morbidity. The blood-brain-barrier (BBB) is a structure consisting primarily of cerebral microvascular endothelial cells, end feet of astrocytes, extracellular matrix, and pericytes. Post-SAH pathophysiology included early brain injury and delayed cerebral ischemia. BBB disruption was a critical mechanism of early brain injury and was associated with other pathophysiological events. These pathophysiological events may propel the development of secondary brain injury, known as delayed cerebral ischemia. Imaging advancements to measure BBB after SAH primarily focused on exploring innovative methods to predict clinical outcome, delayed cerebral ischemia, and delayed infarction related to delayed cerebral ischemia in acute periods. These predictions are based on detecting abnormal changes in BBB permeability. The parameters of BBB permeability are described by changes in computed tomography (CT) perfusion and magnetic resonance imaging (MRI). K_ep seems to be a stable and sensitive indicator in CT perfusion, whereas K^trans is a reliable parameter for dynamic contrast-enhanced MRI. Future prediction models that utilize both the volume of BBB disruption and stable parameters of BBB may be a promising direction to develop practical clinical tools. These tools could provide greater accuracy in predicting clinical outcome and risk of deterioration. Therapeutic interventional exploration targeting BBB disruption is also promising, considering the extended duration of post-SAH BBB disruption.

Impact of Cardiovascular Factors on Pulse Wave Velocity and Total Vascular Resistance in Different Age Group Patients with Cardiovascular Disorders

Background: Pulse Wave Velocity (PWV) is the propagation speed of the wave-induced along the aorta and arterial tree, each time the heart beats. PWV increases with increased arterial stiffness, thus establishing it as a reliable prognostic marker for cardiovascular morbidity and mortality. On the other hand, Total Vascular Resistance (TVR) is the overall resistance offered by systemic circulation and pulmonary circulation. This resistance needs to be overcome in order to create the flow of blood through the circulatory system. The goal of this study was to investigate the influence of different cardiovascular factors on arterial stiffness and vascular resistance in CVD patient from eastern India population.

Methods: Total of 782 patients with Cardiovascular Disease (CVD) like hypertension, Ischemic heart disease, Congestive cardiac failure and peripheral arterial disease were included to evaluate the cardiovascular hemodynamic and non-hemodynamic parameter by oscillometric method and investigated those factors on PWV and TVR in subjects of both sexes aged between 15 to 87 years.

Results: The old age (> 55 years) was found to have greatest impact on PWV as compared with younger age group. Systolic Blood Pressure (SBP), Heart Rate (HR), augmentation pressure and Body Surface Area (BSA) had a positive association with the PWV. Augmentation Index and Body Mass Index (BMI) had a negative impact on the PWV.

Conclusion: Despite the limitations, like unequal number of male and female participants, wide variation of the age of the subjects and analyzing association of many factors at a time, our large and community-based study show individual blood pressure and pulse pressure depending on complex interaction between large arteries and arterioles. This study sheds light on the relationship between proximal and distal part (PWV and TVR) of the arterial tree as well as their association with different hemodynamic and non-hemodynamic parameters.

CT and MR Imaging of the Encephalopathic Child

Background: Neonatal and paediatric encephalopathy can be a diagnostic challenge for clinicians. Potential aetiologies include hypoxic brain injury, stroke, infection, trauma, metabolic and electrolyte abnormalities, autoimmune conditions and drug ingestion. Radiology plays a key role in determining aetiology and, even when normal, directing further assessment.

Conclusion: We present a review of the neuroradiological manifestations of neonatal and paediatric encephalopathies which will aide paediatricians and radiologists in their assessment of children with this condition.

Nosocomial Infections and Antimicrobial Treatment in Coiled Patients with Aneurysmal Subarachnoid Hemorrhage

Background: Nosocomial infections are common in patients with spontaneous subarachnoid hemorrhage (SAH). The aim of this retrospective cohort study was to determine the incidence of infections during SAH and to evaluate the course of inflammation parameters and its implications for long term outcome.

Objective: Ninety-nine consecutive coiled SAH patients were included. Laboratory and clinical parameters as well as culture positive infections were followed over the disease course. Long-term outcome was assessed at 6-month by the Glasgow Outcome score (GOS) and dichotomized in favorable (GOS>3) and unfavorable outcome (GOS≤3).

Results: The most frequent infections were pulmonary (30.3%) urinary tract (25.3%), blood stream infections (20.2%) and ventriculitis (5.1%). The incidence of infections did not significantly differ between outcome groups. In contrast, patients with unfavorable outcome had a higher incidence of sepsis (46.7% versus 24.6%). C-reactive protein (CRP) and leukocytes were significantly higher in patients with unfavorable outcome. A CRP increase of 6 mg/dl or more in the first 3 days after SAH was independently associated with unfavorable outcome (OR 7.19 CI 1.7-30.52; p=0.008). Patients with an early CRP increase were more frequently treated with antimicrobial therapy in the first 3 days after admission which led to a significantly lower incidence of culture positive infections in the later course.

Conclusion: A sharp CRP-increase in the acute phase of SAH could potentially aid the intensivist in the early identification of patients at high risk for neurological morbidity. Early antimicrobial treatment reduces the rate of patients showing culture positive infections in the course of the disease.

Protective Effects of Terpenes on the Cardiovascular System: Current Advances and Future Perspectives

Background: Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide that seriously affect patient’s life quality and are responsible for huge economic and social burdens. It is widely accepted that a plant-based diet may reduce the risk of CVDs by attenuating several risk factors and/or modulating disease’s onset and progression. Plants are rich in secondary metabolites, being terpenes the most abundant and structurally diverse group. These compounds have shown broad therapeutic potential as antimicrobial, antiviral, anti-inflammatory and antitumor agents. Despite their popularity, scientific evidence on terpenes cardiovascular effects remains sparse, limiting their potential use as cardioprotective and/or cardiotherapeutic agents.

Objective: Bearing in mind the lack of comprehensive and systematic studies, the present review aims to gather the knowledge and some of the most scientific evidence accumulated over the past years on the effect of terpenes in the cardiovascular field with focus on CVDs namely ischemic heart disease, heart failure, arrhythmias and hypertension.

Method: Several popular search engines including PubMed, Science Direct, Scopus and Google Scholar were consulted. The bibliographic research focused primarily on English written papers published over the last 15 years.

Results: A systematic and comprehensive update on the cardiovascular effects of terpenes is provided. Moreover, whenever known, the possible mechanisms of action underlying the cardiovascular effects are pointed out as well as an attempt to identify the most relevant structure- activity relationships of the different classes of terpenes.

Conclusion: Overall, this review enables a better understanding of the cardiovascular effects of terpenes, thus paving the way towards future research in medicinal chemistry and rational drug design.

FDG-PET/CT for Systemic Infections

The use of whole-body imaging with ¹⁸F-fluorodeoxyglucose positron emission tomography/ computed tomography (FDG-PET/CT) is increasing in systemic infectious diseases, including fever of unknown origin (FUO), bacteraemia of unknown origin (BUO), and central nervous system infections, since the primary aim is to guide the clinicians towards potential sites of origin for further exploration, and a high sensitivity whole-body assessment is therefore pivotal. The literature on these subjects remains relatively sparse, but the available data and the widespread use in daily clinical practice seem justified in FUO and BUO, while results on CNS infections with systemic components are more equivocal. However, more systematic, well-designed prospective studies in defined patient populations are needed to clarify the controversies, including indications and cost effectiveness, scan parameters, and quantification.

An Intricate Mechanism of Action of Avonex in Relapsing Remitting Multiple Sclerosis Patients: Variation of Serum Titre of Interleukin-17A, Interleukin-10 and Transforming Growth Factor-β

Introduction: The immunopathogenesis of multiple sclerosis (MS) is a main field of research, together with the mechanism of action of most immune therapies in this disease, such as interferon beta. Interleukin (IL)-17 is considered to play a central part in the initial immune cascade in MS, though there are numerous interactions between other cytokines that might explain the heterogeneity of disease evolution and treatment response.

Material and Methods: We tested the serum levels of IL-17A, IL-10 and transforming growth factor (TGF-β) using the enzyme-linked immunosorbent assay method in three small groups of relapsing-remitting MS patients: 10 being naïve without treatment, 10 patients receiving Avonex treatment early in the MS evolution (≤ one year from the MS onset) and 12 MS patients who received Avonex later in the disease evolution. The values were compared with those obtained from 32 healthy subjects using statistical analysis.

Results: In the naive multiple sclerosis group: IL-17A values were statistically higher than among healthy subjects; IL- 17A inversely correlated with MS duration; serum IL-17A negatively correlated with TGF-β. A direct correlation was found between the serum titre of IL-17A and IL-10 in the early treated multiple sclerosis group; the titre of IL-17A was significantly reduced compared with that from the late treated multiple sclerosis group.

Conclusion: The role in MS pathology of IL-17A, IL-10 and TGF-β is only partially elucidated. IL-17 plays an important role in the inflammatory phase of relapsing-remitting MS and is diminished by Avonex mainly if this disease modifying treatment is administered early in the evolution of MS.

Extrahepatic Targets and Cellular Reactivity of Drug Metabolites

Biotransformation is one of the key elements of chemically induced toxicity. Although organisms have an intrinsic tendency to diminish the harm posed by chemical exposure with or without structural modification and excretion of the agents (detoxification), this is not always the case; toxification may also occur. The liver has evolved to be the center of biotransformation from the anatomical, physiological and biochemical points of view; it is located alongside the stomach and intestine, it receives more than 25% of the cardiac output and it contains, in general, the richest quantity but also variety of drug metabolizing enzymes. That is why many orally taken drug-induced toxic effects are seen in the liver. Nevertheless, non-hepatic tissues in the organism are also subjected to toxic insult. Although several instances have suggested transport of liver-bioactivated reactive metabolites to the target tissue is responsible, such as monocrotaline-associated lung toxicity, tetraethyl lead- and n-hexane-associated nervous system toxicity and 2-methoxyethanol-associated testis toxicity, etc. [1], the vast majority of data show local bioactivation in the target tissue is responsible for the extrahepatic toxic outcome. The impact of extrahepatic bioactivation and toxicity of drugs can also be seen in cases of drug attrition due to unacceptable toxicity; adverse cardiovascular effects were the foremost reason for drug withdrawals between 1993 and 2006 [2]. On the other hand, the parent drug and/or its stable metabolite( s) may also cause adverse effects such as inhibition of transporters, occlusion of bile secretion (cholestasis) and accumulation in organelles such as mitochondria, causing steatosis in liver and possibly in other organs. However, this review attempts to summarize only extrahepatic bioactivation of drugs/chemicals and their effects at the cellular and tissue level. Specifically, it focuses on the two most perfused organs, lung and heart tissue, as well as thyroid, blood, brain, and skin. Clozapine, a still-in-use drug with severe off-target toxicities (agranulocytosis and cardiovascular toxicity), is investigated in depth and various drugs are reviewed with a special emphasize on the other mentioned organs.

Relationship Between Na⁺, K⁺-ATPase and NMDA Receptor at Central Synapses

Specific receptors for classical neurotransmitters and neuropeptides, as well as the Na⁺, K⁺-ATPase, are all molecular entities inserted into synaptic region membranes and localized contiguously. Herein, available experimental evidence showing close interactions between the activity of the Na⁺, K⁺-ATPase and the N-methyl-D-aspartate (NMDA) ionotropic glutamate receptor was reviewed, supporting a functional link between these macromolecules. The Na⁺, K⁺- ATPase and NMDA receptor are involved in ion movements through membranes. The former acts as an ion transporter, whereas the latter acts as an ion channel. The modulation of their activity plays a critical role in controlling neuronal function. Examples were taken from studies performed with specific agonists or antagonists of the NMDA receptor. Regarding the Na⁺, K⁺-ATPase, its involvement was postulated after observing its inhibition by ouabain or related cardiac glycosides. Additionally, experimental conditions known to prevent normal Na⁺, K⁺-ATPase (i. e., sodium pump functioning) led to similar valuable information. These findings indicate potential cross-talk between this enzyme and the NMDA receptor. The Na⁺, K⁺-ATPase and NMDA play very important roles in the regulation of learning and memory in the hippocampus. The fact that important changes here described were recorded in the hippocampus indicate a different vulnerability of this area to toxicity induced by the Na⁺, K⁺-ATPase inhibitor ouabain. Some interesting relationships include calcineurin actions, the participation of ERK or Src family kinases, and signaling cascades initiated by calcium. At present, many other examples of signaling related to the NMDA receptor cannot be correlated with Na+, K⁺-ATPase activity. It is desirable that the development of future research offer new clues for the relationship between Na⁺, K⁺-ATPase and NMDA receptor activation.

Metabotropic Glutamate Receptor 5 in Down's Syndrome Hippocampus During Development: Increased Expression in Astrocytes

Metabotropic glutamate receptor 5 (mGluR5) is highly expressed throughout the forebrain and hippocampus. Several lines of evidence support the role of this receptor in brain development and developmental disorders, as well as in neurodegenerative disorders like Alzheimer’s disease (AD). In the present study, the expression pattern of mGluR5 was investigated by immunocytochemistry in the developing hippocampus from patients with Down's syndrome (DS) and in adults with DS and AD. mGluR5 was expressed in developing human hippocampus from the earliest stages tested (9 gestational weeks), with strong expression in the ventricular/subventricular zones. We observed a consistent similar temporal and spatial neuronal pattern of expression in DS hippocampus. However, in DS we detected increased prenatal mGluR5 expression in white matter astrocytes, which persisted postnatally. In addition, in adult DS patients with widespread ADassociated neurodegeneration (DS-AD) increased mGluR5 expression was detected in astrocytes around amyloid plaque. In vitro data confirm the existence of a modulatory crosstalk between amyloid-β and mGluR5 in human astrocytes. These findings demonstrate a developmental regulation of mGluR5 in human hippocampus and suggest a role for this receptor in astrocytes during early development in DS hippocampus, as well as a potential contribution to the pathogenesis of ADassociated pathology.

Cranial Ultrasound - Optimizing Utility in the NICU

Cranial ultrasonography (cUS) is a reliable tool to detect the most frequently occurring congenital and acquired brain abnormalities in full-term and preterm neonates.

Appropriate equipment, including a dedicated ultrasound machine and appropriately sized transducers with special settings for cUS of the newborn brain, and ample experience of the ultrasonographist are required to obtain optimal image quality. When, in addition, supplemental acoustic windows are used whenever indicated and cUS imaging is performed from admission throughout the neonatal period, the majority of the lesions will be diagnosed with information on timing and evolution of brain injury and on ongoing brain maturation. For exact determination of site and extent of lesions, for detection of lesions that (largely or partially) remain beyond the scope of cUS and for depiction of myelination, a single, well timed MRI examination is invaluable in many high risk neonates. However, as cUS enables bedside, serial imaging it should be used as the primary brain imaging modality in high risk neonates.

Advances in Metabonomics on Infectious Diseases

Metabonomics is a powerful holistic approach for biomarker discovery and an effective tool for pinpointing endpoint metabolic effects of external stimuli, such as pathogens. Therefore, metabonomics is a promising method to enhance our understanding of infection mechanism, and holds potential for discovery of novel targets for diagnostics, drugs and vaccines. Due to advances in metabonomics technology, emerging research on infectious diseases in the past decade has been reported. In this review, we emphasise the importance of host metabolic responses to infectious pathogens, including viruses, bacteria and parasites, in the understanding mechanism of infection and potential for diagnostic capability. Researches carried on cell, animal and human models are included. Finally, we conclude with a section on research needs for improved analytical techniques and integrative systems biological approach for in-depth understanding mechanisms of infection.

Antifungal Therapy of Aspergillosis of the Central Nervous System and Aspergillus Endophthalmitis

Cerebral Aspergillosis is the most lethal manifestation of infection due to Aspergillus species arising most commonly as hematogenous dissemination from a pulmonary focus, direct extension from paranasal sinus infection or direct inoculation through trauma and surgery of the central nervous system (CNS). Voriconazole is currently considered the standard of treatment of CNS aspergillosis with liposomal amphotericin B being the next best alternative. Neurosurgical resection of infected cerebral tissue in addition to antifungal therapy is frequently performed in patients with CNS aspergillosis to prevent neurological deficits and improve outcome.

Aspergillus endophthalmitis may occur endogenously mostly from a pulmonary focus or exogenously following eye surgery or trauma. Although amphotericin B is still described as the primary therapy, voriconazole is increasingly considered the first line treatment of Aspergillus endophthalmitis. Vitrectomy is recommended in most cases of Aspergillus endophthalmitis.

The Use of Stem Cells in Regenerative Medicine for Parkinson’s and Huntington’s Diseases

Cell transplantation has been proposed as a means of replacing specific cell populations lost through neurodegenerative processes such as that seen in Parkinson's or Huntington’s diseases. Improvement of the clinical symptoms has been observed in a number of Parkinson and Huntington’s patients transplanted with freshly isolated fetal brain tissue but such restorative approach is greatly hampered by logistic and ethical concerns relative to the use of fetal tissue, in addition to potential side effects that remain to be controlled. In this context, stem cells that are capable of self-renewal and can differentiate into neurons, have received a great deal of interest, as demonstrated by the numerous studies based on the transplantation of neural stem/progenitor cells, embryonic stem cells or mesenchymal stem cells into animal models of Parkinson's or Huntington’s diseases. More recently, the induction of pluripotent stem cells from somatic adult cells has raised a new hope for the treatment of neurodegenerative diseases. In the present article, we review the main experimental approaches to assess the efficiency of cell–based therapy for Parkinson's or Huntington’s diseases, and discuss the recent advances in using stem cells to replace lost dopaminergic mesencephalic or striatal neurons. Characteristics of the different stem cells are extensively examined with a special attention to their ability of producing neurotrophic or immunosuppressive factors, as these may provide a favourable environment for brain tissue repair and long-term survival of transplanted cells in the central nervous system. Thus, stem cell therapy can be a valuable tool in regenerative medicine.

Viral Encephalitis: Current Treatments and Future Perspectives

Several viruses may cause central nervous system infections that lead to a broad range of clinical manifestations. The course of the viral encephalitis can be acute, sub acute, or chronic. Some viruses have the ability to enter into the brain and cause direct injury, while others activate inflammatory cells that attack the central nervous system (CNS) secondarily. Some types of viral encephalitis occur in previously healthy individuals, while others affect immunocompromised patients. The epidemiology of viral encephalitis has undergone changes in recent years. Factors such as evolving lifestyles and ecological changes have had a considerable impact on the epidemiology of some types of viral encephalitis. The result is a change in the etiology spectrum of viral encephalitis, with new types of encephalitis arising or returning from time to time. Many scientific achievements in neuroimaging, molecular diagnosis, antiviral therapy, immunomodulatory treatments, and neurointensive care have allowed more precise and earlier diagnoses and more efficient treatments, resulting in improved outcomes. Despite these advances, there is still considerable morbidity and mortality related to these disorders. This aim of this article is to review the current knowledge of the current drugs used in the management of the most important viral encephalitis, focusing on the mechanisms of action, efficacy, and side effects of the drugs. In addition, future perspectives in this area will be addressed. Despite the technological advances, much effort has yet to be undertaken to reduce the impact of these potentially devastating diseases.

PDE5 Inhibitor Treatment Options for Urologic and Non-Urologic Indications: 2012 Update

Phosphodiesterase (PDE) enzymes are widely distributed throughout the body, having numerous effects and functions. The use of on demand PDE5 inhibitors (-Is) for the treatment of erectile dysfunction (ED) has recently obtained approval for chronic daily dosing for the same indication. There are published data supporting the use of PDE5-Is for the treatment of lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH). Additional reports suggest benefit by these agents in patients with chronic heart failure, pulmonary hypertension, essential hypertension, and for the treatment of ischemia. Various central nervous system disorders have been described as targets by PDE5-Is. Sildenafil may have a potential therapeutic indication as a cognitive enhancer in age-related cerebral conditions. There is preclinical evidence for further investigation of the use of PDE5A -Is to improve recovery of cerebral function in humans after stroke by enhancing angiogenesis, neurogenesis and improving neurologic function. Sildenafil delays intestinal ulceration by an increase in the secretion of mucus/fluid and a decrease in hypermotility, and has a protective effect in reducing gastric damage. Larger scale, well designed clinical trials are needed to ascertain the safety, efficacy and cost-effectiveness of PDE5-Is in the future treatment of both urologic and non-urologic diseases. In this review, potential applications of PDE5-Is on urologic, cardiovascular, gastrointestinal, and central nervous system disorders will be updated.

Ibubrofen in the Treatment of Patent Ductus Arteriosus in Preterm Infants: What We Know, What We Still Do Not Know

The patency of the ductus arteriosus has ever been considered as a pathological situation in preterm infants and one likely cause of mortality and morbidity, including broncho-pulmonary dysplasia, necrotizing enterocolitis, intraventricular haemorrhage, retinopathy of prematurity. The incidence of patent ductus arteriosus is inversely proportional to gestational age and infants with the lowest gestational ages are the most exposed to the complications of prematurity. So, associations between patent ductus arteriosus and the other morbidities may not be causative and patent ductus arteriosus could be more a sign of immaturity and severity of disease than the cause of these problems. Non-steroidal anti-inflammatory agents, such as indomethacin or ibuprofen, have been shown to be effective in closing or preventing patent ductus arteriosus, with differences in side effects. However nearly all randomized controlled trials have been designed with the closure of the ductus arteriosus, not mortality or morbidity, as the main endpoint. Thus, evidence is still lacking on the eventual benefits for the patient of pharmacological or surgical intervention on PDA. Moreover, both ibuprofen and indomethacin efficacy seems markedly reduced in extremely low gestational age infants, who are the most likely to benefit from such intervention. The explanation of the reduced pharmacodymanic effect in such population is unclear; so far, studies using increased dosing of ibuprofen have failed to show a clear benefit. Prophylaxis with indomethacin or ibuprofen has failed to show sustained benefits on neurodevelopment at 2 years of age in low gestational age infants. New curative trials may aim at investigating the effects of early curative administration of ibuprofen, which has reduced side effects compared to indomethacin, on immature kidney function, on mortality and morbidity in very low gestational age infants, ideally with a combined endpoint such as survival in the absence of severe neurodevelopmental alteration at 2 years age. Despite an understandable reluctance given the historical background of systematic, therapeutic closure of ductus arteriosus in preterm infants, there are no definite ethical obstacles to a placebo-controlled design.

Repetitive Transient Phosphodiesterase-3 Inhibition Eliminates Non-ischemic Cardiac Remodeling and Failure

Background: Established therapies against chronic heart failure (CHF) like beta-blockade or renin-angiotensin inhibition still remain insufficient to conquer CHF, mainly because of the presence of non-responder or intolerability because of extremely low cardiac output. Recent report including ours revealed that transient administration of phosphodiesterase- 3 (PDE-III) inhibitor and subsequent PKA activation mimic preconditioning, reduce infarct size and restore cardiac function after myocardial infarction. Since PDE-III inhibition increases cardiac output, we tested whether intermittent transient PDE-III inhibition is also applicable to preventing non-ischemic cardiac remodeling and failure.

Methods and Results: Male Wistar-Kyoto rats underwent inhibition of nitric oxide synthase by L-NAME for 8 weeks, in the presence or absence of PDE-III inhibitor olprinone by gavage once a day, 3 times a week. L-NAME specifically increased blood pressure, promoted LV hypertrophy and remodeling. Hydralazine totally canceled blood pressure increase but unaffected LV remodeling and reduced contraction, as reported previously. Olprinone was well tolerated and reduced LV hypertrophy, fibrosis and wet lung weight/body weight ratio but unchanged high blood pressure afforded by L-NAME, suggesting that olprinone inhibited the progression of cardiac remodeling and failure beyond blood pressurelowering. Furthermore, LV infiltration of polymorphic neutrophils induced by L-NAME was eliminated by olprinone.

Conclusion: The intermittent transient PDE-III inhibition elicits cardioprotection against non-ischemic heart failure beyond hemodynamic effects, and the inhibition of inflammatory change might be involved in pathophysiology. Since PDE-III inhibition provides positive inotropic effect, this therapy might be a widely acceptable option for patients even with poor response to conventional therapies or severely low cardiac output.

Neurocysticercosis: The Enigmatic Disease

Neurocysticercosis (NCC) is an infection of the central nervous system (CNS) caused by the metacestode larval form of the parasite Taenia sp. Many factors can contribute to the endemic nature of cysticercosis. The inflammatory process that occurs in the tissue surrounding the parasite and/or distal from it can result from several associated mechanisms and may be disproportionate with the number of cysts. This discrepancy may lead to difficulty with the proper diagnosis in people from low endemic regions or regions that lack laboratory resources. In the CNS, the cysticerci have two basic forms, isolated cysts (Cysticercus cellulosae = CC) and racemose cysts (Cysticercus racemosus = CR), and may be meningeal, parenchymal, or ventricular or have a mixed location. The clinical manifestations are based on two fundamental syndromes that may occur in isolation or be associated: epilepsy and intracranial hypertension. They may be asymptomatic, symptomatic or fatal; have an acute, sub-acute or chronic picture; or may be in remission or exacerbated. The cerebrospinal fluid (CSF) may be normal, even in patients with viable cysticerci, until the patients begin to exhibit the classical syndrome of NCC in the CSF, or show changes in one or more routine analysed parameters. Computed tomography (CT) and magnetic resonance imaging (MRI) have allowed non-invasive diagnoses, but can lead to false negatives. Treatment is a highly controversial issue and is characterised by individualised therapy sessions. Two drugs are commonly used, praziquantel (PZQ) and albendazole (ABZ). The choice of anti-inflammatory drugs includes steroids and dextrochlorpheniramine (DCP). Hydrocephalus is a common secondary effect of NCC. Surgical cases of hydrocephalus must be submitted to ventricle-peritoneal shunt (VPS) immediately before cysticidal treatment, and surgical extirpation of the cyst may lead to an absence of the surrounding inflammatory process. The progression of NCC may be simple or complicated, have remission with or without treatment and may exhibit symptoms that can disappear for long periods of time or persist until death. Unknown, neglected and controversial aspects of NCC, such as the impaired fourth ventricle syndrome, the presence of chronic brain oedema and psychic complaints, in addition to the lack of detectable glucose in the CSF and re-infection are discussed.

Neurotuberculosis: An Overview

Although pulmonary tuberculosis is the most common form of this disease, neurotuberculosis is more severe and presents higher morbidity and mortality. Its diagnosis continues to challenge physicians all over the world. Contributing to this fact is the nonspecificity of its clinical manifestations, the low density of bacilli in the cerebrospinal fluid (CSF), and the delayed recovery of Mycobacterium tuberculosis through culture techniques. Thus, the diagnosis is largely based on suspicious symptoms, and the prognosis is directly related to the stage of the disease at the beginning of treatment. Even thought there is no consensus regarding the best therapeutic regimen, the WHO recommends using the same regimen used for pulmonary tuberculosis with a longer treatment time. It is important to note that in most cases, the doctor will not have a definite diagnosis at the beginning of the treatment. However, this should not delay the initiation of therapy. A delay in initiating treatment, in most cases, is directly associated with a poor prognosis. This review gives an overview of the current state of the neurotuberculosis research. It covers the epidemiological aspects of the infection, pathogenesis, principal clinical presentations, diagnosis highlighting neuroimaging, where a series of imaging are presented, prognosis, prevention and therapeutic regimens.

p38 MAP Kinase Inhibitors as Potential Therapeutic Drugs for Neural Diseases

Mammalian p38 mitogen-activated protein kinases (MAPKs) are activated by various cellular stresses, as well as in response to inflammatory cytokines. In the central nervous systems (CNS), activation of the p38 MAPK pathway constitutes a key step in the development of several diseases, and the molecular mechanisms mediated by p38 MAPK signaling have been defined. Activation of this cascade releases pro-inflammatory cytokines that are known to be involved in cerebral ischemia, Alzheimers disease (AD), Parkinsons disease (PD), multiple sclerosis (MS), neuropathic pain and depression. In AD, stimulated p38 MAPK may trigger the hyperphosphorylation of a neural microtubule-associated protein, tau. In addition, we have recently revealed that activation of p38 MAPK signaling decreases dendritic spine number, which may be associated with memory impairment after epileptic seizures. Thus, p38 MAPK can serve as a target for novel drug development for neural diseases. p38 MAPK inhibitors have been studied extensively in both preclinical experiments and clinical trials for inflammatory diseases. New p38 MAPK inhibitors are now being tested in phase II clinical trials for neuropathic pain and depression. Here, we review current and possible future applications of p38 MAPK inhibitors as therapeutic agents in neural diseases.

The Role of Mitochondria in Brain Aging and the Effects of Melatonin

Melatonin is an endogenous indoleamine present in different tissues, cellular compartments and organelles including mitochondria. When melatonin is administered orally, it is readily available to the brain where it counteracts different processes that occur during aging and age-related neurodegenerative disorders. These aging processes include oxidative stress and oxidative damage, chronic and acute inflammation, mitochondrial dysfunction and loss of neural regeneration. This review summarizes age related changes in the brain and the importance of oxidative/nitrosative stress and mitochondrial dysfunction in brain aging. The data and mechanisms of action of melatonin in relation to aging of the brain are reviewed as well.

Significance of High Levels of Endogenous Melatonin in Mammalian Cerebrospinal Fluid and in the Central Nervous System

Levels of melatonin in mammalian circulation are well documented; however, its levels in tissues and other body fluids are yet only poorly established. It is obvious that melatonin concentrations in cerebrospinal fluid (CSF) of mammals including humans are substantially higher than those in the peripheral circulation. Evidence indicates that melatonin produced in pineal gland is directly released into third ventricle via the pineal recess. In addition, brain tissue is equipped with the synthetic machinery for melatonin production and the astrocytes and glial cells have been proven to produce melatonin. These two sources of melatonin may be responsible for its high levels in CNS. The physiological significance of the high levels of melatonin in CNS presumably is to protect neurons and glia from oxidative stress. Melatonin as a potent antioxidant has been reported to be a neuroprotector in animals and in clinical studies. It seems that long term melatonin administration which elevates CSF melatonin concentrations will retard the progression of neurodegenerative disorders, for example, Alzheimer disease.

Aquaporin Biology and Nervous System

Our understanding of the movement of water through cell membranes has been greatly advanced by the discovery of a family of water-specific, membrane-channel proteins: the Aquaporins (AQPs). These proteins are present in organisms at all levels of life, and their unique permeability characteristics and distribution in numerous tissues indicate diverse roles in the regulation of water homeostasis. Phenotype analysis of AQP knock-out mice has confirmed the predicted role of AQPs in osmotically driven transepithelial fluid transport, as occurs in the urinary concentrating mechanism and glandular fluid secretion. Regarding their expression in nervous system, there are evidences suggesting that AQPs are differentially expressed in the peripheral versus central nervous system and that channel-mediated water transport mechanisms may be involved in cerebrospinal fluid formation, neuronal signal transduction and information processing. Moreover, a number of recent studies have revealed the importance of mammalian AQPs in both physiological and pathophysiological mechanisms and have suggested that pharmacological modulation of AQP expression and activity may provide new tools for the treatment of variety of human disorders in which water and small solute transport may be involved. For all the AQPs, new contributions to physiological functions are likely to be discovered with ongoing work in this rapidly expanding field of research.

Treatment of Viral Encephalitis

Several viruses may cause central nervous system diseases with a broad range of clinical manifestations. The time course of the viral encephalitis can be acute, subacute, or chronic. Pathologically there are encephalitis with direct viral entry into the CNS in which brain parenchyma exhibits neuronal damaging and viral antigens and there are postinfectious autoimmune encephalitis associated with systemic viral infections with brain tissue presenting perivascular aggregation of immune cells and myelin damaging. Some virus affect previously healthy individuals while others produce encephalitis among imunocompromised ones. Factors such evolving lifestyles and ecological changes have had a considerable impact on the epidemiology of some viral encephalitis [e.g. West-Nile virus, and Japanese B virus]. Citomegalovirus and JC virus are examples of infections of the brain that have been seen more frequently because they occur in immunocompromised patients. In the other hand many scientific achievements in neuroimaging, molecular diagnosis, antiviral therapy, immunomodulatory treatments, and neurointensive care have allowed more precise and earlier diagnoses and more efficient treatments, resulting in improved outcomes. In this article, we will present the current drug options in the management of the main acute and chronic viral infection of the central nervous system of immunocompetent and immunocompromised adults, focusing on drugs mechanisms of action, efficacy, and side effects. The early diagnosis and correct management of such diseases can reduce mortality and neurological sequelae; however, even with recent treatment advances, potentially devastating outcomes are still possible.

Amyloidophilic Compounds for Prion Diseases

Recent outbreaks of variant Creutzfeldt-Jakob disease and iatrogenic Creutzfeldt-Jakob disease have aroused great concern in many countries and have necessitated the development of suitable therapies. We have demonstrated that sulfated glycans such as pentosan polysulfate and fucoidan, and amyloidophilic compounds such as amyloid dye derivatives, styrylbenzoazole derivatives, and phenylhydrazine derivatives have efficacies in prion-infected animals. Amyloidophilic compounds present potentialities not only as therapeutic candidates but also as prion amyloid imaging probes for use in nuclear medicine technology such as positron emission tomography. A representative of styrylbenzoazole compounds has been used recently for clinical trials of brain prion amyloid imaging in patients. On the other hand, a representative of phenylhydrazine compounds, compB, displays excellent effectiveness in prolonging the incubation times of infected animals when given orally. However, both its anti-prion effectiveness in vitro and its therapeutic efficacy in vivo are consistently dependent on the prion strain. This prion-strain-dependency is similarly observed in other amyloidophilic compounds. Therefore, aside from further improvement of the safety profiles and pharmacokinetic properties of such compounds, elucidation and management in the mechanism of the prion straindependent effectiveness is necessary. Nevertheless, because compB studies suggest that amyloidophilic compounds are also therapeutic candidates for Alzheimers disease, amyloidophilic compounds might be attractive as drug candidates for various conformational diseases and hasten development of therapeutic drugs for prion diseases.

Alterations in Cerebral Metabolomics and Proteomic Expression during Sepsis

The cause of brain dysfunction during sepsis and septic encephalopathy is still under ongoing research. Sepsis induced changes in cerebral protein expression may play a significant role in the understanding of septic encephalopathy. The aim of the present study was to explore cerebral proteome alterations in septic rats. Fifty-six male Wistar rats were randomly assigned to a sepsis group (coecal ligature and puncture, CLP) or a control group (sham). Surviving rats were killed 24 or 48 hours after surgery and whole-brain lysates were used for two-dimensional gel electrophoresis and subsequent protein identification. Differentially expressed proteins were identified by mass spectrometry. Using the Ingenuity Pathways Analysis (IPA) tool, the relationship and interaction between the identified proteins was analyzed. Mortality was 53 % in septic rats. No rat of the control group was lost. More than 1,100 spots per gel were discriminated of which 29 different proteins were significantly (2-fold, P < 0.01) changed: 24 proteins down-regulated after 24 hours; two proteins up-regulated and three down-regulated after 48 hours. IPA identified 11 of 35 differentially regulated proteins allocating them to an existing inflammatory pathway. In the analysis of septic rat brains, multiple differentially expressed proteins associated with metabolism, signaling, and cell stress can be identified via proteome analysis, that may help to understand the development of septic encephalopathy.

Role of ABC Transporters in the Chemoresistance of Human Gliomas

Malignant gliomas are frequently chemoresistant and this resistance seems to depend on at least two mechanisms. First, the poor penetration of many anticancer drugs across the blood-brain barrier (BBB), the blood-cerebrospinal fluid barrier (BCSFB) and blood-tumor barrier (BTB), due to their interaction with several ATP-binding cassette (ABC) drug efflux transporters that are overexpressed by the endothelial or epithelial cells of these barriers. Second, resistance may involve the tumor cells themselves. Although ABC drug efflux transporters in tumor cells confer multidrug resistance (MDR) on several other solid tumors, their role in gliomas is unclear. This review focuses on astrocytes and summarizes the current state of knowledge about the expression, distribution and function of ABC transporters in normal and tumor astroglial cells. The recognition of anticancer drugs by ABC transporters in astroglial cells and their participation in the multidrug resistance phenotype of human gliomas is discussed.

Melanocortin Receptors as Drug Targets for Disorders of Energy Balance

There is overwhelming evidence that the brain melanocortin system is a key regulator of energy balance, and dysregulations in the brain melanocortin system can lead to obesity. The melanocortin system is one of the major downstream leptin signaling pathways in the brain. In contrast to leptin, preclinical studies indicate that diet-induced obese animals are still responsive to the anorectic effects of melanocortin receptor agonists, suggesting the melanocortin system is an interesting therapeutic opportunity. Besides regulating energy balance, melanocortins are involved in a variety of other neuroendocrine processes, including inflammation, blood pressure regulation, addictive and sexual behavior, and sensation of pain. This review evaluates the melanocortin system function from the perspective to use specific melanocortin (MC) receptors as drug targets, with a focus on the treatment of obesity and eating disorders in humans, and the implications this may have on mechanisms beyond the control of energy balance.