Role of exosomes in the pathogenesis of inflammation in Parkinson’s disease

Inflammatory responses,including glial cell activation and peripheral immune cell infiltration,are involved in the pathogenesis of Parkinson’s disease(PD).These inflammatory responses appear to be closely related to the release of extracellular vesicles,such as exosomes.However,the relationships among different forms of glial cell activation,synuclein dysregulation,mitochondrial dysfunction,and exosomes are complicated.This review discusses the multiple roles played by exosomes in PD-associated inflammation and concludes that exosomes can transport toxicα-synuclein oligomers to immature neurons and into the extracellular environment,inducing the oligomerization ofα-synuclein in normal neurons.Misfoldedα-synuclein causes microglia and astrocytes to activate and secrete exosomes.Glial cell-derived exosomes participate in communications between glial cells and neurons,triggering anti-stress and anti-inflammatory responses,in addition to axon growth.The production and release of mitochondrial vesicles and exosomes establish a new mechanism for linking mitochondrial dysfunction to systemic inflammation associated with PD.Given the relevance of exosomes as mediators of neuron-glia communication in neuroinflammation and neuropathogenesis,new targeted treatment strategies are currently being developed that use these types of extracellular vesicles as drug carriers.Exosome-mediated inflammation may be a promising target for intervention in PD patients.     

Mechanisms of antinociceptive effects of ouabain in combination with neostigmine in the rat***★

BACKGROUND： It has been previously shown that intrathecal administration of either ouabain or neosdgmine can produce antinociceptive effects. Moreover, ouabain and neostigmine are differently associated with acetylcholine.
OBJECTIVE： It has been hypothesized that intrathecal administration of ouabain, in combination with neostigmine, can produce antinociceptive synergistic effects. Atropine, as a competitive antagonist, was pre-injected to verify the mechanisms of action.
DESIGN, TIME AND SETTING： This study was a randomized, controlled, animal experiment, performed at the State Key Laboratory of Oncology in Southern China between May 2006 and February 2007.
MATERIALS： A total of 102 healthy, adult, Sprague Dawley rats were included. Ouabain and neostigmine （Sigma, USA）, as well as atropine （Tanabe Seiyaku, Japan）, were also used.
METHODS： Varied doses of ouabain, neostigmine, and a combination of the two were intrathecally injected into rats. Six rats were allotted for each dose group. Intrathecal pretreatment with atropine was tested 10 minutes prior to intrathecal administration of neostigmine or the combination of ouabain and neostigmine.
MAIN OUTCOME MEASURES： Tail-flick tests were performed to measure tail-flick latency （seconds） prior to and after administration. The response in the tail-flick test was expressed as the percentage of maximum possible effect （% MPE）, where % MPE = [tail-flick latency after administration （seconds） -mean baseline value for tail-flick latency]/[ 10 seconds - the mean baseline value for tail-flick latency （seconds）] x 100%.
RESULTS： Rat spinal intrathecal administration of either ouabain or neostigmine alone produced antinociceptive effects in a dose-dependent manner. Intrathecally administration of neostigmine （0.05, 0.1, 0.3 μg ） in combination with ouabain （1 μ g ） produced enhanced antinociceptive effects, with a % MPE of 29%, 78%, and 95%, respectively （P 〈 0.05）. Intrathecally administration of 0.3μg neost     

Involvement of NO–cGMP pathway in anti-anxiety effect of aminoguanidine in stressed mice

In the present study, effect of aminoguanidine (12.5, 25 and 50 mg/kg, i.p.), a selective inhibitor of inducible nitric oxide synthase, was evaluated for its anti-anxiety activity in stressed mice employing elevated plus maze, open field test, light/dark test and social interaction test. Restraint stress induced by immobilizing for 6 h enhanced an anxiety-like behavior and increased plasma nitrite levels in mice. Only the highest dose (50 mg/kg) employed of aminoguanidine attenuated the stress-induced anxiety-like behavior and decreased plasma nitrite levels. There was no significant anxiolytic effect of aminoguanidine in unstressed mice. Sildenafil (1 mg/kg i.p.), was used to explore the probable mechanism of anti-anxiety activity of aminoguanidine through NO–cGMP signaling. Aminoguanidine (50 mg/kg) attenuated the anxiogenic effect of sildenafil. Aminoguanidine and sildenafil per se and in combination did not affect the locomotor activity of stressed and unstressed mice as compared to their respective control groups. Thus, aminoguanidine produced anti-anxiety activity in stressed mice through iNOS–NO–cGMP pathway.     

Effects of in vivo and in vitro administration of neuro-Behcet’s disease IgG

Antibodies directed against membrane antigens of neuronal axonal processes (neuropil) have been recently identified in neuro-Behcet’s disease (NBD) patients. To delineate the potential pathogenic action of these antibodies, pooled sera from seven NBD patients with neuropil antibodies and seven healthy controls were divided into purified IgG and IgG-depleted serum (IgG-DS) fractions and each fraction was administered into lateral ventricles of rats. NBD IgG-injected rats showed reduced locomotor activity in the open field test as compared to NBD IgG-DS, healthy control IgG, healthy control IgG-DS and PBS injected rats (n = 10 for each group). There were no significant differences among treatment groups by means of anxiety-like behaviors (assessed by elevated plus maze test) and learning/memory functions (assessed by passive avoidance test). Administration of NBD IgG on cultured SH-SY5Y neuroblastoma cells induced significantly increased cell death and apoptosis (as measured by nucleosome levels in the supernatants) as compared to other treatment groups. Our results suggest that IgGs isolated from sera of neuropil antibody-positive NBD patients have a neurotoxic action, which is presumably mediated by apoptotic mechanisms. Motor deficits frequently observed in NBD patients might at least partially be caused by the pathogenic action of anti-neuronal IgG.     

Observation of treatment of depression in primary care setting in first week - what happens in first week of treatment with antidepressants?

Depression is frequently diagnosed and treated by general practicioners. In observational study we investigated the influence of the severity of depressive and anxiety symptoms on the frequency of patients' questions about mental disorder and their tendency to misinterpret the signs and symptoms of depression as side effects of medication. In 60 public health centers across Slovenia a total of 422 patients with depression treated with paroxetine were included. After one week of treatment one quarter of patients reported adverse effects and 15% of these patients misinterpreted signs of depression and anxiety for adverse effects. These patients tend to be more anxious and more depressed at the beginning of treatment. Half of them could not accept the explanation of their misinterpretation. A total of 55% patients had additional questions about illness at the second visit and these patients were also more anxious and more depressed at the beginning of treatment.     

Accumulation of α-synuclein in the bowel of patients in the pre-clinical phase of Parkinson’s disease

Parkinson’s disease primarily affects the central nervous system, but autopsy and small patient studies have revealed autonomic nervous system pathology in most cases. We looked for α-synuclein pathology in routinely acquired biopsies from patients and matched controls. Immunocytochemistry was performed and assessed blind to the clinical diagnoses. One hundred and seventeen gastrointestinal tissue samples from 62 patients, and 161 samples from 161 controls, were examined. Twelve biopsies from seven patients showed accumulation of α-synuclein within mucosal and submucosal nerve fibres, and ganglia, which was more extensive with an antibody to phosphorylated, than with an antibody to non-phosphorylated, α-synuclein. These included gastric, duodenal and colonic biopsies, and were taken up to 8 years prior to the onset of motor symptoms. All patients with positive biopsies had early autonomic symptoms and all controls were negative. This large scale study demonstrates that accumulation of α-synuclein in the gastrointestinal tract is a highly specific finding that could be used to confirm a clinical diagnosis of Parkinson’s disease. We have shown that α-synuclein accumulation occurs prior to the onset of motor symptoms in the upper, as well as the lower gastrointestinal tract, remains present in serial biopsies until the onset of motor symptoms and is predominantly composed of phosphorylated α-synuclein. Accumulation of α-synuclein in the bowel therefore offers an accessible biomarker which allows further study of the early stages of the disease and could be of value in the assessment of disease modifying treatments.     

Investigation of the prevalence of essential tremor in individuals aged 18–60 in Erzurum

Essential tremor (ET) is one of the common neurological diseases and it is the most common movement disorder in adults. The main clinical finding in patients with ET is kinetic tremor in the arms. There is no adequate study investigating the prevalence of ET in Turkey. Therefore, this study was planned in the center of the city of Erzurum in order to determine the prevalence of essential tremor in our region. This study was performed door to door in the center of the city of Erzurum. ET screening questionnaires were administered to all participants between the ages of 18–60 at first stage. Those who answer yes to any of the first five questions of the questionnaire were evaluated. Patients without a clear differential diagnosis were called for examination to the neurology department and they were re-evaluated by a faculty member specializing in movement disorders. Patients were classified by using Washington Heights-Inwood Genetic Study of Essential Tremor diagnostic and clinical evaluation scale. The prevalence of ET was calculated as 1.60 % (64 out of 4,024 participants). 30 of the cases were male and 34 were female. First-degree relatives of 30 patients with ET had a history of tremor. While 52 patients had tremor only in their hands, 11 patients had in various organs including hands. There was isolated head tremor in one patient. ET prevalence was increasing with age. The prevalence of ET in people between the ages of 18 and 60 was calculated as 1.60 %. This value is compatible with other measurements of the prevalence of ET.     

Adaptation of skull clamp for use in image-guided surgery of children in the first 2 years of life

Introduction We describe a simple but effective modification of the skull clamp, aimed at stabilising the head of very young children, while avoiding the risk of creating a depressed skull fracture, in order to enable the utilisation of image-guidance in such young patients.Methods We machined three small perspex discs 3 cm in diameter. On the outer surface of these pads we drilled reception holes for the pins to prevent slippage. To avoid direct contact with the skin, we interfaced a thick pad of soft felt. During intraoperative positioning, the weight of the head was supported by a suction bean-bag placed on the operating table. Hence, the clamp apparatus was employed only to secure the head position, and not to support the weight of the head, thus requiring less clamp force. We employed this modification in three children (aged 9, 13 and 15 months) who required image-guided surgery for brain tumours.Outcome In all cases the head remained immobile throughout the operation, making possible the accurate use of image guidance. At the end of the operation, some transient skin redness was noticed in the contact areas, which settled in a few days.The material in this paper was presented as a poster at the 31st Annual Meeting of the International Society for Pediatric Neurosurgery, Monaco, 14–18 September 2003     

The use of University of Pennsylvania Smell Identification Test in the diagnosis of Parkinson’s disease in Italy

Hyposmia is a common finding in Parkinson’s disease (PD). The 40-item University of Pennsylvania Smell Identification Test (UPSIT-40) has been adapted and administered in several countries as a diagnostic tool in the diagnosis of PD. We have developed a culturally adapted version of the UPSIT-40 and applied it to 61 nondemented Italian controls and to 68 PD patients. Multiple linear regression analysis was performed to assess the factors that independently influence UPSIT-40 and logistic regression analysis was employed to study the usefulness of UPSIT-40 to predict PD diagnosis. Multiple linear regression analysis showed that PD diagnosis (p < 0.001), age (p = 0.006), gender (p = 0.003) and smoking status (p = 0.03) were significant independent predictors of the UPSIT-40 total score. Using diagnosis as dependent variable, logistic regression analysis showed that UPSIT-40 total score (p < 0.001) was an independent predictor of PD. Using a score ≤21/40 as a cut-off point for assigning subjects to PD group, the UPSIT-40 total score differentiated PD and control subjects with 82 % sensitivity and 88.2 % specificity. The adapted version of UPSIT-40 may be useful in addition to clinical examination to improve accuracy of diagnosis of PD in Italian population.     

Regional differences in expression of β-tubulin isoforms in schizophrenia

A growing body of evidence suggests that abnormal elements of the cytoskeleton may be associated with the pathophysiology of schizophrenia. Isoforms of a major cytoskeleton protein, β-tubulin, were recently demonstrated to have distinct roles in neuronal differentiation and cell viability. For these reasons, we tested the hypothesis that there are differences in the expression of β-tubulin isoforms (βI-βIV) in the brain in schizophrenia, using western blot analysis in an elderly group of subjects with this illness and a control group. We found that βI-tubulin protein expression was decreased in the anterior cingulate cortex and increased in the dorsolateral prefrontal cortex, but not changed in superior temporal gyrus or hippocampus in schizophrenia. Our data supports the growing body of evidence suggesting abnormalities of the cytoskeleton in schizophrenia.     

Role of ammonia in reversal of glutamate-mediated Müller cell swelling in the rat retina

Glutamate is thought to participate in a variety of retinal degenerative disorders. However, when exposed to glutamate at concentrations up to 1 mM, ex vivo rat retinas typically exhibit Müller cell swelling, but not excitotoxic neuronal damage. This Müller cell swelling is reversible following glutamate washout, indicating that the glial edema is not required for glutamate-induced neuronal injury. It is unclear whether glutamate directly induces the Müller cell swelling or whether a metabolite of glutamate such as glutamine acts as an osmolyte to generate the cellular edema. To examine this issue, ex vivo rat retinas were exposed to 1 mM glutamate or 1 mM glutamine and were evaluated histologically. Glutamate was also combined with 1 mM ammonia or with methionine sulfoximine (MSO), an inhibitor of glutamine synthetase, the enzyme that catalyzes the synthesis of glutamine from glutamate and ammonia. Glutamate-mediated Müller cell swelling was blocked by co-administration of ammonia and the reversibility of Müller cell swelling was inhibited by MSO administered following glutamate exposure. Glutamine alone failed to induce Müller cell swelling. These results indicate that glutamate-mediated Müller cell swelling is unlikely to result from glutamine accumulation. Rather, conversion of glutamate to glutamine in a reaction involving ammonia helps reverse Müller cell swelling following exposure to exogenous glutamate.     

Attenuation of perceptual asymmetries in patients with early-onset schizophrenia: evidence in favour of reduced hemispheric differentiation in schizophrenia?

Lateral biases in visual perception have been demonstrated in normal individuals and in patients with unilateral brain lesions. It has been suggested that the absence of structural and functional asymmetries in schizophrenia could be due to a failure in lateralisation that may be most pronounced in those patients whose illness onset is at an early age. Here we examined lateral biases in patients with schizophrenia of an early onset (N = 21) and a late onset (N = 19), and their respective age-matched control groups, using the greyscales task, a sensitive measure of asymmetries in visual processing. The stimuli consisted of two rectangles, one above the other, shaded in opposite directions and matched overall for darkness. Participants judged which of the two rectangles looked darker overall. Previous studies using this task in healthy participants have reported a reliable bias, such that the rectangle with the darker end on the left is selected preferentially. Whereas the late-onset patients in this study exhibited a perceptual bias of similar direction and magnitude to that of controls, this was not the case for the early-onset patients, who exhibited significantly less bias than their control group. The reduced perceptual bias seen in the early-onset group, but not the late-onset group, suggests an attenuation of right hemisphere mechanisms dedicated to processing visuospatial information. The attenuated perceptual asymmetry in the early-onset group only may be consistent with the view that (i) an earlier illness onset reflects a greater loss of hemispheric differentiation and (ii) reduced functional asymmetries in the early-onset group are a manifestation of a failure to allocate functions to one or the other hemisphere.     

Changes in the Expression of Genes of the Glutamate Transporter and Subunits of the NMDA and AMPA Receptors in the Rat Amygdala in the Lithium–Pilocarpine Model of Epilepsy

The molecular changes in the glutamatergic system of the rat amygdala were studied during the latent phase of the lithium–pilocarpine model of temporal lobe epilepsy in order to identify the potential involvement of these changes in epileptogenesis. The real-time PCR method was used to evaluate the mRNA expression of the NMDA and AMPA receptor subunits, as well as the excitatory amino acid transporter-2 (EAAT2) in the basolateral nucleus of the amygdala 7 days after the seizures caused by administration of pilocarpine. The results of the experiments were as follows: (1) an increase in the expression ratio of the GluN2a/GluN2b NMDA receptor subunits with an unchanged expression level of the GluN1 subunit; (2) increased expression of the GluA2 subunit of AMPA receptors with the invariance of GluA1, and (3) enhanced expression of the EAAT2. According to literature data, the expression of the same genes decreased in the hippocampus in the same model of epilepsy. Neurodegeneration was reported in both brain regions. The opposite changes in the expression of the glutamatergic system genes in the hippocampus and amygdala during the latent period of the lithium–pilocarpine model suggest the occurrence of factors that can both contribute to and hinder epileptogenesis.     

A role for cannabinoids in the treatment of myotonia? Report of compassionate use in a small cohort of patients

Journal of Neurology - The symptomatic treatment of myotonia and myalgia in patients with dystrophic and non-dystrophic myotonias is often not satisfactory. Some patients anecdotally report...     

An ecological study of temporal trends in ‘deaths of despair’ in England and Wales

Social Psychiatry and Psychiatric Epidemiology - There is growing interest in the concept of ‘deaths of despair’ (DoD)—defined as deaths from three causes: suicide, drug...     

A cluster of multiple sclerosis cases in Lysvik in the Swedish county of Värmland

Objectives – When surveying the county of Värmland in Sweden in order to determine the prevalence of multiple sclerosis (MS), we observed an aggregation of MS cases originating from the parish of Lysvik in the local region called Fryksdalen. Our intention was to analyse this cluster thoroughly, confirming the MS diagnosis and seeing if a hereditary or environmental background was plausible. Methods – The medical files were studied and the cases were classified by a neurologist according to Poser's criteria. Hereditary factors were analysed. Results – Sixteen living cases of MS were found, either living in the parish (n = 6) or born or raised there and had later moved to another place (n = 10). All patients had clinically definite MS. Eleven patients had relatives with MS, all of these being descendants of the Suhoinen family. Another two cases were Suhoinen descendants who did not have relatives with MS. Other common ancestors were also identified. Two cases were adopted. Eleven deceased MS patients from Lysvik were found, 10 of them had Suhoinen ancestry. Conclusion – We report a cluster of MS cases with a common ancestry indicating heredity for MS in 85% of the cases. Lysvik is a parish where Finnish immigration was pronounced in the 17th century and there has been inbreeding to a certain extent through marriage between cousins. Thus, we interpret this aggregation as possibly being genetically based, and neurogenetic studies are now being performed. However, as two of the cases were adopted environmental factors must also be considered.     

Evaluation of modified hemodilution combined therapy in the treatment of acute ischemic stroke in the elderly

IN T R O D U C T IO N Atpresent, throm bolysis therapy applied atthe early stage is devel- oped in patients w ith acute stroke, and itw orks w elland decreases disability rate.Butthrom bolysis therapy is notsuitable forsom e elder- ly patients w ho delaye…     

Are subjects in pharmacological treatment trials of depression representative of patients in routine clinical practice?

OBJECTIVE: The methods used to evaluate the efficacy of antidepressants differ from treatment for depression in routine clinical practice. The rigorous inclusion/exclusion criteria used to select subjects for participation in efficacy studies potentially limit the generalizability of these trials' results. It is unknown how much impact these criteria have on the representativeness of subjects in efficacy trials. This study estimated the proportion of depressed patients treated in routine clinical practice who would meet standard inclusion/exclusion criteria for an efficacy trial. METHOD: A total of 803 individuals, aged 16--65 years, who were seen at intake at an outpatient practice underwent a thorough diagnostic evaluation, including the administration of semistructured diagnostic interviews; 346 patients had current major depression. Common inclusion/exclusion criteria used in efficacy studies of antidepressants were applied to the depressed patients to determine how many would have qualified for an efficacy trial. RESULTS: Approximately one-sixth of the 346 depressed patients would have been excluded from an efficacy trial because they had a bipolar or psychotic subtype of depression. The presence of a comorbid anxiety or substance use disorder, insufficient severity of depressive symptoms, or current suicidal ideation would have excluded 86.0% (N=252) of the remaining 293 outpatients with nonpsychotic unipolar major depressive disorder from an antidepressant efficacy trial. CONCLUSIONS: Subjects treated in antidepressant trials represent a minority of patients treated for major depression in routine clinical practice. These results show that antidepressant efficacy trials tend to evaluate a subset of depressed individuals with a specific clinical profile.