Eradication of Helicobacter pylori may be beneficial in the management of Alzheimer's disease
ABSTRACT Infectious agents have been proposed as potential causes of Alzheimer's disease (AD). Recently, we documented a high prevalence of Helicobacter pylori (Hp) infection in patients with AD. We aim to access the effect of Hp eradication on the AD cognitive (MMSE: Mini Mental State Examination and CAMCOG: Cambridge Cognitive Examination for the Elderly) and functional (FRSSD: Functional Rating Scale for Symptoms of Dementia) status parameters. In the first part of the study, a total of 50 consecutive patients with AD and 30 age-matched anaemic controls underwent an upper gastrointestinal endoscopy, and gastric mucosal biopsies were obtained to detect the presence of Hp infection by histologic analysis and rapid urease test. Serum anti-Hp-specific IgG level was analysed by enzyme-linked immunosorbent assay. In the second part, Hp-positive AD patients received a triple eradication regimen (omeprazole, clarithromycin and amoxicillin), and all patients were followed up for 2 years, while under the same treatment with cholinesterase inhibitors. Hp was detected in 88% of AD patients and in 46.7% of controls (P < 0.001). Hp eradication was successful in 84.8% of treated patients. At the 2-year clinical endpoint, cognitive and functional status parameters improved in the subgroup of patients where Hp eradication was successful (P < 0.001 and P = 0.049 for MMSE and CAMCOG, respectively; P < 0.001 for FRSSD), but not in the other patients. Hp eradication may positively influence AD manifestations, suggesting a possible common link between Hp and AD.
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ABSTRACT: Management of Helicobacter pylori infection is evolving and in this 4th edition of the Maastricht consensus report aspects related to the clinical role of H pylori were looked at again in 2010. In the 4th Maastricht/Florence Consensus Conference 44 experts from 24 countries took active part and examined key clinical aspects in three subdivided workshops: (1) Indications and contraindications for diagnosis and treatment, focusing on dyspepsia, non-steroidal anti-inflammatory drugs or aspirin use, gastro-oesophageal reflux disease and extraintestinal manifestations of the infection. (2) Diagnostic tests and treatment of infection. (3) Prevention of gastric cancer and other complications. The results of the individual workshops were submitted to a final consensus voting to all participants. Recommendations are provided on the basis of the best current evidence and plausibility to guide doctors involved in the management of this infection associated with various clinical conditions.Gut 05/2012; 61(5):646-64. DOI:10.1136/gutjnl-2012-302084 · 13.32 Impact Factor
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ABSTRACT: Dogs with Canine Cognitive Dysfunction (CCD) accumulate amyloid beta (Aβ) in the brain. As the cognitive decline and neuropathology of these old dogs share features with Alzheimer's disease (AD), the relation between Aβ and cognitive decline in animal models of cognitive decline is of interest to the understanding of AD. However, the sensitivity of the biomarker Pittsburgh Compound B (PiB) to the presence of Aβ in humans and in other mammalian species is in doubt. To test the sensitivity and assess the distribution of Aβ in dog brain, we mapped the brains of dogs with signs of CCD (n = 16) and a control group (n = 4) of healthy dogs with radioactively labeled PiB ([(11)C]PiB). Structural magnetic resonance imaging brain scans were obtained from each dog. Tracer washout analysis yielded parametric maps of PiB retention in brain. In the CCD group, dogs had significant retention of [(11)C]PiB in the cerebellum, compared to the cerebral cortex. Retention in the cerebellum is at variance with evidence from brains of humans with AD. To confirm the lack of sensitivity, we stained two dog brains with the immunohistochemical marker 6E10, which is sensitive to the presence of both Aβ and Aβ precursor protein (AβPP). The 6E10 stain revealed intracellular material positive for Aβ or AβPP, or both, in Purkinje cells. The brains of the two groups of dogs did not have significantly different patterns of [(11)C]PiB binding, suggesting that the material detected with 6E10 is AβPP rather than Aβ. As the comparison with the histological images revealed no correlation between the [(11)C]PiB and Aβ and AβPP deposits in post-mortem brain, the marked intracellular staining implies intracellular involvement of amyloid processing in the dog brain. We conclude that PET maps of [(11)C]PiB retention in brain of dogs with CCD fundamentally differ from the images obtained in most humans with AD.Frontiers in Aging Neuroscience 12/2013; 5:99. DOI:10.3389/fnagi.2013.00099 · 2.84 Impact Factor
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ABSTRACT: It is widely accepted that hypoperfusion and changes in capillary morphology are involved in the etiopathogenesis of Alzheimer's disease (AD). This is difficult to reconcile with the hyperperfusion observed in young high-risk subjects. Differences in the way cerebral blood flow (CBF) is coupled with the local metabolic needs during different phases of the disease can explain this apparent paradox. This review describes this coupling in terms of a model of cerebral oxygen availability that takes into consideration the heterogeneity of capillary blood flow patterns. The model predicts that moderate increases in heterogeneity requires elevated CBF in order to maintain adequate oxygenation. However, with progressive increases in heterogeneity, the resulting low tissue oxygen tension will require a suppression of CBF in order to maintain tissue metabolism. The observed biphasic nature of CBF responses in preclinical AD and AD is therefore consistent with progressive disturbances of capillary flow patterns. Salient features of the model are discussed in the context of AD pathology along with potential sources of increased capillary flow heterogeneity.Neurobiology of aging 10/2012; 34(4). DOI:10.1016/j.neurobiolaging.2012.09.011 · 4.85 Impact Factor