656 research outputs found
Pro: Can neuropathology really confirm the exact diagnosis?
Recent advances in the clinical diagnostic instruments for diagnosing Alzheimer's disease (AD) and in neuroimaging may cast doubt in the minds of some practitioners about the continued need for neuropathology to provide the ultimate diagnosis. Certainly the majority of cases of AD can be clinically correctly diagnosed by experienced clinicians but many cases are given this label by less experienced practitioners. Even after the most thorough work-up, a few cases of confidently diagnosed AD turn out to be something else when microscopy of the brain is undertaken. Even for neuropathologists, however, it can be difficult to correctly assign cognitive decline to the various pathological processes that can be found together in an older brain. We need further clinicopathogical study to enlighten us about, for example, the contribution of commonly found cerebrovascular disease to dementia. Human studies are also needed to explore the changes in pathology that new treatments for AD may produce
Size of hippocampal pyramidal neurons in schizophrenia
Background Meta-analyses of
hippocampal size have indicated thatthis
structure is smaller in schizophrenia.This
could reflect a reductioninthe size of
constituent neurons or a reduced number
of neurons.
Aims To measure the size of
hippocampalpyramidalneuronsinthe hippocampalpyramidalneurons inthe
brains of peoplewith andwithout
schizophrenia.
Method Pyramidalneuron size in
hippocampal subfieldswas estimated
stereologically fromsections taken at
5mmintervals throughoutthewhole
length of right and left hippocampi from
andleft the brains of13 peoplewith schizophrenia
and16 controls.Resultswere assessed
using repeated-measures analysis of
covariance looking for amain effectof
diagnosis and gender, andinteractions of
and interactions thesewith side.
Results Wewere unable to detect
significantdifferences related to diagnosis,
gender or side for any hippocampal
subfield for this series of cases.
Conclusions For this series of brains,
hippocampal cell size is unchangedin
schizophrenia
The Impact of International Broadcasting On Africa
This study examined the impact of global broadcasting on Africa. The survey research method was applied to collect data with the structured questionnaire as the research instrument. 150 respondents who were purposively selected from Nigeria, South Africa and Egypt were administered the questionnaire online through the surveymonkey.com website. However, 110 respondents properly completed and submitted their questionnaires representing 73 percent response rate. Findings revealed that Cable News Network (CNN) is the preferred global TV news channel of 41 percent of the respondents followed by Al Jezeera (32 percent), China Central Television (18 per cent) and BBC World (9 percent). This is consistent with the 2012 European Media Survey (EMS) report which declared CNN as the undisputed No 1 news brand in Africa. Findings further revealed that global TV news channels carried mostly negative stories about Africa as indicated by 86 percent of the respondents. Furthermore, 60 percent of the respondents indicated that this pattern of coverage not only gave the continent a negative perception but worsened her economic woes. The study concluded that decades after the New World Information and Communication Order debate was rested, negative coverage of the continent persists in the powerful global TV news channels. It then recommended that global TV channels still need to do more to improve on their coverage of Africa by focusing less on negative reports from the continent. It further recommended that stakeholders in the region need to take more practical steps to tell their own stories to the outside world. Key words Global television   International communication  Coverage  News  channel
Proliferation, bcl-2 expression and angiogenesis in pituitary adenomas: relationship to tumour behaviour
The prediction of pituitary tumour behaviour, in terms of response to treatment from which can be derived optimal management strategies, is a challenge that has been approached using several different means. Angiogenesis in other tumour types has been shown to be correlated with poor response to treatment and tumour recurrence. The aim of this paper is to assess the role of measurements of cell proliferation and angiogenesis in predicting pituitary tumour behaviour. The proliferative capacity of the tumour was assessed using the Ki-67 labelling index (LI) while bcl-2 expression was used to assess anti-apoptotic pathways. The microvessel density (MVD) was assessed using antibodies to CD31 and factor VIII-related antigen, and with biotinylated ulex europaeus agglutinin I. There was no difference between Ki-67 LI and MVD of functionless tumours that recurred and those that did not, but bcl-2 expression was significantly lower in tumours that subsequently regrew. Macroprolactinomas had significantly higher LI than microprolactinomas and than all other tumours. Cell proliferation and angiogenesis were not related, showing that both processes are under different control mechanisms in pituitary tumours. In contrast there was a positive relationship between markers of angiogenesis and bcl-2 expression in prolactinomas, GH-secreting tumours and non-recurrent functionless tumours with higher levels of bcl-2 expression being found in the more vascular tumours. These findings may suggest that angiogenesis is related to the ability of tumour cells to survive rather than their proliferative activity. © 2000 Cancer Research Campaig
Complement and humoral adaptive immunity in the human choroid plexus: roles for stromal concretions, basement membranes, and epithelium
The choroid plexus (CP) provides a barrier to entry of toxic molecules from the blood into the brain and transports vital molecules into the cerebrospinal fluid. While a great deal is known about CP physiology, relatively little is known about its immunology. Here, we show immunohistochemical data that help define the role of the CP in innate and adaptive humoral immunity. The results show that complement, in the form of C1q, C3d, C9, or C9neo, is preferentially deposited in stromal concretions. In contrast, immunoglobulin (Ig) G (IgG) and IgA are more often found in CP epithelial cells, and IgM is found in either locale. C4d, IgD, and IgE are rarely, if ever, seen in the CP. In multiple sclerosis CP, basement membrane C9 or stromal IgA patterns were common but were not specific for the disease. These findings indicate that the CP may orchestrate the clearance of complement, particularly by deposition in its concretions, IgA and IgG preferentially via its epithelium, and IgM by either mechanism
IL-21 and IL-21 Receptor Expression in Lymphocytes and Neurons in Multiple Sclerosis Brain
IL-17âproducing CD4+ T cells (Th-17) contribute to the pathogenesis of experimental autoimmune encephalomyelitis and are associated with active disease in multiple sclerosis (MS). In addition to IL-17, Th-17 cells can also express IL-21, IL-22, and IL-6 under Th-17âpolarizing conditions (IL-6 and transforming growth factor-ÎČ). In this study we investigated IL-21 and IL-21 receptor (IL-21R) expression in MS lesions by in situ hybridization and immunohistochemistry. We detected strongly IL-21+ infiltrating cells predominantly in acute but also in chronic active white matter MS lesions in which IL-21 expression was restricted to CD4+ cells. In contrast, IL-21R was much more broadly distributed on CD4+, CD19+, and CD8+ lymphocytes but not major histocompatibility complex class-II+ macrophages/microglia. Interestingly, in cortical areas we detected both IL-21 and IL-21R expression by neurons. These findings suggest role(s) for IL-21 in both the acute and chronic stages of MS via direct effects on T and B lymphocytes and, demonstrated for the first time, also on neurons
Evidence for a novel neuronal mechanism driving Alzheimer's disease, upstream of amyloid
This perspective offers an alternative to the amyloid hypothesis in the etiology of Alzheimer's disease (AD). We review evidence for a novel signaling mechanism based on a littleâknown peptide, T14. T14 could drive neurodegeneration as an aberrantly activated process of plasticity selective to interconnecting subcortical nuclei, the isodendritic core, where cell loss starts at the preâsymptomatic stages of the disease. Each of these cell groups has the capacity to form T14, which can stimulate production of pâTau and ÎČâamyloid, suggestive of an upstream driver of neurodegeneration. Moreover, results in an animal AD model show that antagonism of T14 with a cyclated variant, NBP14, prevents formation of ÎČâamyloid, and restores cognitive function to that of wildâtype counterparts. Any diagnostic and/or therapeutic strategy based on T14âNBP14 awaits validation in clinical trials. However, an understanding of this novel signaling system could bring muchâneeded fresh insights into the progression of cell loss underlying AD. Highlights: The possible primary mechanism of neurodegeneration upstream of amyloid. Primary involvement of selectively vulnerable subcortical nuclei, isodendritic core. Bioactive peptide T14 trophic in development but toxic in context of mature brain. Potential for earlyâstage biomarker to detect Alzheimer's disease. Effective therapeutic halting neurodegeneration, validated already in 5XFAD mice
Cases, Regulations, and Statutes
With the exception of ApoE4, genome-wide association studies have failed to identify strong genetic risk factors for late-onset Alzheimer's disease, despite strong evidence of heritability, suggesting that many low penetrance genes may be involved. Additionally, the nature of the identified genetic risk factors and their relation to disease pathology is also largely obscure. Previous studies have found that a cancer-associated variant of the cell cycle inhibitor gene p21cip1 is associated with increased risk of Alzheimer's disease. The aim of this study was to confirm this association and to elucidate the effects of the variant on protein function and Alzheimer-type pathology. We examined the association of the p21cip1 variant with Alzheimer's disease and Parkinson's disease with dementia. The genotyping studies were performed on 719 participants of the Oxford Project to Investigate Memory and Ageing, 225 participants of a Parkinson's disease DNA bank, and 477 participants of the Human Random Control collection available from the European Collection of Cell Cultures. The post mortem studies were carried out on 190 participants. In the in-vitro study, human embryonic kidney cells were transfected with either the common or rare p21cip1 variant; and cytometry was used to assess cell cycle kinetics, p21cip1 protein expression and sub-cellular localisation. The variant was associated with an increased risk of Alzheimer's disease, and Parkinson's disease with dementia, relative to age matched controls. Furthermore, the variant was associated with an earlier age of onset of Alzheimer's disease, and a more severe phenotype, with a primary influence on the accumulation of tangle pathology. In the in-vitro study, we found that the SNPs reduced the cell cycle inhibitory and anti-apoptotic activity of p21cip1. The results suggest that the cancer-associated variant of p21cip1 may contribute to the loss of cell cycle control in neurons that may lead to Alzheimer-type neurodegeneration
Concurrent multiple sclerosis and amyotrophic lateral sclerosis: where inflammation and neurodegeneration meet?
The concurrence of multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) is exceedingly rare and the pathological features have not been examined extensively. Here we describe the key pathological features of a 40 year old man with pathologically confirmed concurrent MS and ALS
Immunohistochemical study of N-epsilon-carboxymethyl lysine (CML) in human brain: relation to vascular dementia
<p>Abstract</p> <p>Background</p> <p>Advanced glycation end-products (AGEs) and their receptor (RAGE) occur in dementia of the Alzheimer's type and diabetic microvascular disease. Accumulation of AGEs relates to risk factors for vascular dementia with ageing, including hypertension and diabetes. Cognitive dysfunction in vascular dementia may relate to microvascular disease resembling that in diabetes. We tested if, among people with cerebrovascular disease, (1) those with dementia have higher levels of neuronal and vascular AGEs and (2) if cognitive dysfunction depends on neuronal and/or vascular AGE levels.</p> <p>Methods</p> <p>Brain Sections from 25 cases of the OPTIMA (Oxford Project to Investigate Memory and Ageing) cohort, with varying degrees of cerebrovascular pathology and cognitive dysfunction (but only minimal Alzheimer type pathology) were immunostained for N<sup><it>Δ</it></sup>-(carboxymethyl)-lysine (CML), the most abundant AGE. The level of staining in vessels and neurons in the cortex, white matter and basal ganglia was compared to neuropsychological and other clinical measures.</p> <p>Results</p> <p>The probability of cortical neurons staining positive for CML was higher in cases with worse cognition (p = 0.01) or a history of hypertension (p = 0.028). Additionally, vascular CML staining related to cognitive impairment (p = 0.02) and a history of diabetes (p = 0.007). Neuronal CML staining in the basal ganglia related to a history of hypertension (p = 0.002).</p> <p>Conclusion</p> <p>CML staining in cortical neurons and cerebral vessels is related to the severity of cognitive impairment in people with cerebrovascular disease and only minimal Alzheimer pathology. These findings support the possibility that cerebral accumulation of AGEs may contribute to dementia in people with cerebrovascular disease.</p
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