Lankesterella alencari n. sp., a toxoplasma-like organism in the central nervous system of Amphibia (Protozoa, Sporozoa)

Lankesterella alencari n. sp. a Sporozoa that occur in the blood and CNS of the South American frog Leptodactylus acellatus is described. Since the tissue forms of this parasite have been previously reported as belonging to the genus Toxoplasma, we attempted in fection of 2 species of amphibia (Bufo marinus an dLeptodactylus ocellatus) with a Toxoplasma strain of human origen; inoculation was by intraperitoneal injection of parasite-containing ascitic fluid from infected mice. Attempt of experimental inoculation of the parasite found in the CNS of L. ocellatus in a highly susceptible host (mice) was unsuccessful. These results suggest that Toxoplasma does not occur naturally in the amphibia; be related to Toxoplasma is excluded. The following genera of haematozoa found in brazilian amphibia have been considered briedfly: Haemobartonella, Cytamoeba, Dactylosoma, Hepatozoon and Trypanosoma.

Neuromodulation by oxytocin and vasopressin in the central nervous system as a basis for their rapid behavioral effects

The last several years have seen an increasing number of studies that describe effects of oxytocin and vasopressin on the behavior of animals or humans. Studies in humans have reported behavioral changes and, through fMRI, effects on brain function. These studies are paralleled by a large number of reports, mostly in rodents, that have also demonstrated neuromodulatory effects by oxytocin and vasopressin at the circuit level in specific brain regions. It is the scope of this review to give a summary of the most recent neuromodulatory findings in rodents with the aim of providing a potential neurophysiological basis for their behavioral effects. At the same time, these findings may point to promising areas for further translational research towards human applications.

Development of natural products as drugs acting on central nervous system

We have recenty studied several natural product constituents which have effects on the CNS. (1) Tetrahydropalmatine (THP) and its analogues were isolated from Corydalis ambigua and various species of Stephania. (+)-THP and (-)-THP posses not only analgesic activity, but also exert sedative-tranquillizing and hypnotic actions. Results of receptor binding assay and their pre-and post-synaptic effects on dopaminergic system indicate that (-)-THP and (-)-stepholidine are dopamine receptor antagonists while (+)-THP is a selective dopamine depletor. (2) 3-Acetylaconitine (AAC) is an alkaloid isolated from Aconitum flavum. The relative potency of analgesic action of AAC was 5.1-35.6 and 1250-3912 times that of morphine and aspirin, respectively. The analgesic effect of AAC was antagonized by naloxone, but was eliminated by reserpine. In monkeys, after AAC was injected for 92 days, no abstinence syndrome was seen after sudden AAC withdrawal or when challenged with nalorphine. (3) Huperzine A (Hup-A) is an alkaloid isolated from Huperzia serrata which was found to be a selective ChE inhibitor and could improve learning and retrieval process. Preliminary clinical studies showed that Hup-A improve short-and long-term memory in patients of cerebral arteriosclerosis with memory impairment. (4) Ranamargarin is a new tetradecapeptide isolated from the skin of the Chines frog Rana margaratae. This peptide may mainly act on NK-1 receptor.

Central nervous system stimulants and sport practice.

BACKGROUND AND OBJECTIVES: Central nervous system (CNS) stimulants may be used to reduce tiredness and increase alertness, competitiveness, and aggression. They are more likely to be used in competition but may be used during training to increase the intensity of the training session. There are several potential dangers involving their misuse in contact sports. This paper reviews the three main CNS stimulants, ephedrine, amfetamine, and cocaine, in relation to misuse in sport. METHODS: Description of the pharmacology, actions, and side effects of amfetamine, cocaine, and ephedrine. RESULTS: CNS stimulants have psychotropic effects that may be perceived to be ergogenic. Some are prescription drugs, such as Ephedra alkaloids, and there are issues regarding their appropriate therapeutic use. Recently attention has been given to their widespread use by athletes, despite the lack of evidence regarding any ergogenic or real performance benefit, and their potentially serious side effects. Recreational drugs, some of which are illegal (cocaine, amfetamines), are commonly used by athletes and cause potential ergolytic effects. Overall, these drugs are important for their frequent use and mention in anti-doping laboratories statistics and the media, and their potentially serious adverse effects. CONCLUSIONS: Doping with CNS stimulants is a real public health problem and all sports authorities should participate in its prevention. Dissemination of information is essential to prevent doping in sport and to provide alternatives. Adequate training and education in this domain should be introduced.

Involvement of central nervous system in the schistosomiasis

The involvement of the central nervous system (CNS) by schistosomes may or may not determine clinical manifestations. When symptomatic, neuroschistosomiasis (NS) is one of the most severe presentations of schistosomal infection. Considering the symptomatic form, cerebral involvement is almost always due to Schistosoma japonicum and the spinal cord disease, caused by S. mansoni or S. haematobium. Available evidence suggests that NS depends basically on the presence of parasite eggs in the nervous tissue and on the host immune response. The patients with cerebral NS usually have the clinical manifestations of increased intracranial pressure associated with focal neurological signs; and those with schistosomal myeloradiculopathy (SMR) present rapidly progressing symptoms of myelitis involving the lower cord, usually in association with the involvement of the cauda esquina roots. The diagnosis of cerebral NS is established by biopsy of the nervous tissue and SMR is usually diagnosed according to a clinical criterion. Antischistosomal drugs, corticosteroids and surgery are the resourses available for treating NS. The outcome is variable and is better in cerebral disease.

Irinotecan-induced central nervous system toxicity: a case report.

Here we describe the first case, to our knowledge, of CNS [Central nervous system] toxicity in a patient treated with irinotecan.

Central nervous system involvement at first relapse in patients with acute promyelocytic leukemia treated with all-trans retinoic acid and anthracycline monochemotherapy without intrathecal prophylaxis.

BACKGROUND The prevalence of and risk factors for central nervous system recurrence in patients with acute promyelocytic leukemia are not well established and remain a controversial matter. DESIGN AND METHODS Between 1996 and 2005, 739 patients with newly diagnosed acute promyelocytic leukemia enrolled in two consecutive trials (PETHEMA LPA96 and LPA99) received induction therapy with all-trans retinoic acid and idarubicin. Consolidation therapy comprised three courses of anthracycline monochemotherapy (LPA96), with all-trans retinoic acid and reinforced doses of idarubicin in patients with an intermediate or high risk of relapse (LPA99). Central nervous system prophylaxis was not given. RESULTS Central nervous system relapse was documented in 11 patients. The 5-year cumulative incidence of central nervous system relapse was 1.7% (LPA96 3.2% and LPA99 1.2%; p=0.09). The cumulative incidence was 0%, 0.8%, and 5.5% in low-, intermediate-, and high-risk patients, respectively. Relapse risk score (p=0.0001) and the occurrence of central nervous system hemorrhage during induction (5-year cumulative incidence 18.7%, p=0.006) were independent risk factors for central nervous system relapse. CONCLUSIONS This study shows a low incidence of central nervous system relapse in patients with acute promyelocytic leukemia following therapy with all-trans retinoic acid and anthracycline without specific central nervous system prophylaxis. Central nervous system relapse was significantly associated with high white blood cell counts and prior central nervous system hemorrhage, which emerged as independent prognostic factors.

Standardisation of Western blotting to detect HTLV-1 antibodies synthesised in the central nervous system of HAM/TSP patients

Intrathecal synthesis of human T-lymphotropic virus type 1 (HTLV-1) antibodies (Abs) represents conclusive evidence of a specific immune response in the central nervous system of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Western blotting (WB) for HTLV Abs in serum is a confirmatory test for HTLV-1 infection. The aim of this study was to standardise the Western blot to demonstrate the intrathecal pattern of Abs against HTLV-1 proteins in HAM/TSP patients. Paired cerebrospinal fluid (CSF) and serum samples were selected from 20 patients with definite HAM/TSP, 19 HTLV-1 seronegative patients and two HTLV-1 patients without definite HAM/TSP. The presence of reactive bands of greater intensity in the CSF compared to serum (or bands in only the CSF) indicated the intrathecal synthesis of anti-HTLV-1 Abs. All definite HAM/TSP patients presented with an intrathecal synthesis of anti-HTLV-1 Abs; these Abs were not detected in the control patients. The most frequent intrathecal targets of anti-HTLV-1 Abs were GD21, rgp46-I and p24 and, to a lesser extent, p19, p26, p28, p32, p36, p53 gp21 and gp46. The intrathecal immune response against env (GD21 and rgp46-I) and gag (p24) proteins represents the most important humoral pattern in HAM/TSP. This response may be used as a diagnostic marker, considering the frequent association of intrathecal anti-HTLV-1 Ab synthesis with HAM/TSP and the pathogenesis of this neurological disease.

Creatine, central nervous system and creatine deficiency syndromes

It was long thought that most of brain creatine was of peripheral origin. However, recentworks have demonstrated that creatine crosses blood-brain barrier only with poor efficiency, and thatCNS must ensure parts of its creatine needs by its own creatine synthesis pathway, thank to the brainexpression of AGAT and GAMT (creatine synthesis) and SLC6A8 (creatine transporter). This newunderstanding of creatine metabolism and transport in CNS allows a better comprehension of creatinedeficiency syndromes, which are due to deficiencies in AGAT, GAMT and SLC6A8 and mainly affectthe brain of patients who show severe neurodevelopmental delay and present neurological symptomsin early infancy.

Clinical Proton MR Spectroscopy in Central Nervous System Disorders.

A large body of published work shows that proton (hydrogen 1 [(1)H]) magnetic resonance (MR) spectroscopy has evolved from a research tool into a clinical neuroimaging modality. Herein, the authors present a summary of brain disorders in which MR spectroscopy has an impact on patient management, together with a critical consideration of common data acquisition and processing procedures. The article documents the impact of (1)H MR spectroscopy in the clinical evaluation of disorders of the central nervous system. The clinical usefulness of (1)H MR spectroscopy has been established for brain neoplasms, neonatal and pediatric disorders (hypoxia-ischemia, inherited metabolic diseases, and traumatic brain injury), demyelinating disorders, and infectious brain lesions. The growing list of disorders for which (1)H MR spectroscopy may contribute to patient management extends to neurodegenerative diseases, epilepsy, and stroke. To facilitate expanded clinical acceptance and standardization of MR spectroscopy methodology, guidelines are provided for data acquisition and analysis, quality assessment, and interpretation. Finally, the authors offer recommendations to expedite the use of robust MR spectroscopy methodology in the clinical setting, including incorporation of technical advances on clinical units. © RSNA, 2014 Online supplemental material is available for this article.

Clinical characteristics and outcome of isolated extracerebral relapses of primary central nervous system lymphoma: a case series.

There is very limited data on isolated systemic relapses of primary central nervous system lymphomas (PCNSL). We retrospectively reviewed the clinical characteristics and outcome of 10 patients with isolated systemic disease among 209 patients with PCNSL mainly treated with methotrexate-based chemotherapy (CT) with or without radiation therapy (RT). Isolated systemic relapse remained rare (4.8%, 10/209 patients). Median time from initial diagnosis to relapse was 33 months (range, 3-94). Sites of relapse were mostly extranodal. Three patients presented with early extra-cerebral (EC) relapse 3, 5 and 8 months from the beginning of initial treatment, respectively, and 7 patients had later relapses (range, 17-94 months). Treatment at relapse included surgery alone, RT alone, CT with or without radiotherapy, or CT with autologous stem cell transplantation (ASCT). Median overall survival (OS) after relapse was 15.5 months (range, 5.8-24.5) compared to 4.6 months (range, 3.6-6.5) for patients with central nervous system (CNS) relapse (p = 0.35). In conclusion, isolated systemic relapses exist but are infrequent. Early EC relapse suggests the presence of systemic disease undetectable by conventional evaluation at initial diagnosis. Patient follow-up must be prolonged because systemic relapse can occur as late as 10 years after initial diagnosis. Whether EC relapses of PCNSL have a better prognosis than CNS relapses needs to be assessed in a larger cohort. Copyright © 2010 John Wiley & Sons, Ltd.

Canine distemper virus : persistence and pathology in the central nervous system

Résumé : Le virus de la maladie de Carré (en anglais: canine distemper virus, CDV) qui est pathogène pour les chiens et autres carnivores, est très semblable au virus de la rougeole humaine (en anglais MV). Ces deux virus font partie du genre des Morbillivirus qui appartient à la famille des Paramyxoviridae. Ils induisent des complications dans le système nerveux central (SNC). Au stade précoce et aigu de l'infection du SNC, le CDV induit une démyélinisation (1). Ce stade évolue dans certains cas vers une infection chronique avec progression de la démyélinisation. Pendant le stade précoce, qui suit en général de trois semaines les premiers symptômes, le processus de démyélinisation est associé à la réplication du virus et n'est pas considéré comme inflammatoire (1). Par contre, au stade chronique, la progression des plaques de démyélinisation semble être plutôt liée à des processus immunogènes caractéristiques (2), retrouvés également dans la sclérose en plaques (SEP) chez les humains. Pour cette raison, le CDV est considéré comme un modèle pour la SEP humaine et aussi pour l'étude des maladies et complications induites par les Morbillivirus en général (3). Dans notre laboratoire, nous avons utilisé la souche A75/17-CDV, qui est considérée comme le modèle des souches neurovirulentes de CDV. Nous avons cherché en premier lieu à établir un système robuste pour infecter des cultures neuronales avec le CDV. Nous avons choisi les cultures primaires de l'hippocampe du nouveau-né de rat (4), que nous avons ensuite infecté avec une version modifiée du A75/17, appelée rgA75/17-V (5). Dans ces cultures, nous avons prouvé que le CDV infecte des neurones et des astrocytes. Malgré une infection qui se diffuse lentement entre les cellules, cette infection cause une mort massive aussi bien des neurones infectés que non infectés. En parallèle, les astrocytes perdent leur morphologie de type étoilé pour un type polygonal. Finalment, nous avons trouvé une augmentation importante de la concentration en glutamate dans le milieu de culture, qui laisse présumer une sécrétion de glutamate par les cultures infectées (6). Nous avons ensuite étudié le mécanisme des effets cytopathiques induits par le CDV. Nous avons d'abord démontré que les glycoprotéines de surface F et H du CDV s'accumulent massivement dans le réticulum endoplasmique (RE). Cette accumulation déclenche un stress du RE, qui est caractérisé par une forte expression du facteur de transcription proapoptotique CHOP/GADD 153 et de le la calreticuline (CRT). La CRT est une protéine chaperonne localisée dans le RE et impliquée dans l'homéostasie du calcium (Ca2+) et dans le repliement des protéines. En transfectant des cellules de Vero avec des plasmides codant pour plusieurs mutants de la glycoprotéine F de CDV, nous avons démontré une corrélation entre l'accumulation des protéines virales dans le RE et l'augmentation de l'expression de CRT, le stress du RE et la perte de l'homéostasie du Ca2+. Nous avons obtenu des résultats semblables avec des cultures de cellules primaires de cerveau de rat. Ces résultats suggèrent que la CRT joue un rôle crucial dans les phénomènes neurodégénératifs pendant l'infection du SNC, notamment par le relazgage du glutamate via le Ca2+. De manière intéressante, nous démontrons également que l'infection de CDV induit une fragmentation atypique de la CRT. Cette fragmentation induit une re-localisation et une exposition sélective de fragments amino-terminaux de la CRT, connus pour êtres fortement immunogènes à la surface des cellules infectées et non infectées. A partir de ce résultat et des résultats précédents, nous proposons le mécanisme suivant: après l'infection par le CDV, la rétention dans le RE des protéines F et H provoque un stress du RE et une perte de l'homéostasie du Ca2+. Ceci induit la libération du glutamate, qui cause une dégénération rapide du SNC (sur plusieurs jours ou semaines) correspondant à la phase aiguë de la maladie chez le chien. En revanche, les fragments amino-terminaux de la CRT libérés à la surface des cellules infectées peuvent avoir un rôle important dans l'établissement d'une démyélinisation d'origine immunogène, typique de la phase chronique de l'infection de CDV. Summary : The dog pathogen canine distemper virus (CDV), closely related to the human pathogen measles virus (MV), belongs to the Morbillivirus genus of the Paramyxoviridae family. Both CDV and NIV induce complications in the central nervous system (CNS). In the acute early stage of the infection in CNS, the CDV infection induces demyelination. This stage is sometimes followed by a late persistent stage of infection with a progression of the demyelinating lesions (1). The acute early stage occurs around three weeks after the infection and demyelinating processes are associated with active virus replication and are not associated to inflammation (1). In contrast during late persistent stage, the demyelination plaque progression seems to be mainly due to an immunopathological process (2), which characteristics are shared in many aspects with the human disease multiple sclerosis (MS). For these reasons, CDV is considered as a model for human multiple sclerosis, as well as for the study of Morbillivirus-mediated pathogenesis (3). In our laboratory, we used the A75/17-CDV strain that is considered to be the prototype of neurovirulent CDV strain. We first sought to establish a well characterized and robust model for CDV infection of a neuronal culture. We chose primary cultures from newborn rat hippocampes (4) that we infected with a modified version of A75/17, called rgA75/17-V (5). In these cultures, we showed that CDV infects both neurons and astrocytes. While the infection spreads only slowly to neighbouring cells, it causes a massive death of neurons, which includes also non-infected neurons. In parallel, astrocytes undergo morphological changes from the stellate type to the polygonal type. The pharmacological blocking of the glutamate receptors revealed an implication of glutamatergic signalling in the virus-mediated cytopathic effect. Finally, we found a drastic increase concentration of glutamate in the culture medium, suggesting that glutamate was released from the cultured cells (6). We further studied the mechanism of the CDV-induced cytopathic effects. We first demonstrated that the CDV surface glycoprotein F and H markedly accumulate in the endoplasmic reticulum (ER). This accumulation triggers an ER stress, which is characterized by increased expression of the proapoptotic transcription factor CHOP/GADD 153 and calreticulin (CRT). CRT is an ER resident chaperon involved in the Ca2+ homeostasis and in the response to misfolded proteins. Transfections of Vero cells with plasmids encoding various CDV glycoprotein mutants reveal a correlation between accumulation of viral proteins in the ER, CRT overexpression, ER stress and alteration of ER Ca2+ homeostasis. Importantly, similar results are also obtained in primary cell cultures from rat brain. These results suggest that CRT plays a crucial role in CNS infection, particularly due to CRT involvement in Ca2+ mediated glutamate releases, and subsequent neurodegenerative disorders. Very intriguingly, we also demonstrated that CDV infection induces an atypical CRT fragmentation, with relocalisation and selective exposure of the highly immunogenic CRT N-terminal fragments at the surface of infected and neighbouring non-infected cells. Altogether our results combined with previous findings suggest the following scenario. After CDV infection, F and H retention alter Ca2+ homeostasis, and induce glutamate release, which in turn causes rapid CNS degeneration (within days or a week) corresponding to the acute phase of the disease in dogs. In contrast, the CRT N-terminal fragments released at the surface of infected cells may rather have an important role in the establishment of the autoimmune demyelination in the late stage of CDV infection.