THE ASSOCIATION OF GASTRO-DUODENAL ULCERATION AND PARKINSON'S DISEASE

Update: Protective and risk factors for Parkinson disease

We review the epidemiologic literature on potential protective and risk factors in Parkinson's Disease (PD). Prior research identified numerous possible protective and risk factors. Potential protective factors include tobacco abuse, physical activity, urate levels, NSAID use, calcium channel blocker use, statin use, and use of some α1-adrenergic antagonists. Some potential protective factors could be products of reverse causation, including increased serum urate, tobacco abuse, and coffee-tea-caffeine consumption. Potential risk factors include traumatic brain injury, pesticide exposure, organic solvent exposure, lead exposure, air pollution, Type 2 Diabetes, some dairy products, cardiovascular disease, and some infections including Hepatitis C, H. pylori, and COVID-19. Potential non-environmental risk factors include bipolar disorder, essential tremor, bullous pemphigoid, and inflammatory bowel disease. There is an inverse relationship with PD and risk of most cancers. Though many potential protective and risk factors for PD were identified, research has not yet led to unique, rigorous prevention trials or successful disease-modifying interventions. While efforts to reduce exposure to some industrial toxicants are well justified, PD incidence might be most effectively reduced by mitigation of risks, such as Type 2 Diabetes, air pollution, traumatic brain injury, or physical inactivity, that are general public health intervention targets.

RNA sequencing and proteomic profiling reveal alterations by MPTP in chronic stomach mucosal injury in tree shrew Chinese (Tupaia belangeri chinensis)

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin that can cause gastrointestinal ulcers by affecting dopamine levels. Therefore, MPTP has been considered a toxic substance that causes gastric ulcer disease in experimental animals. In this study, tree shrews were used as the animal model of gastric mucosa injury, and MPTP was intraperitoneally injected at a lower MPTP dosage 2 mg/kg/day for 13 weeks, while tree shrews were not injected as the control group. Under the light microscope, local congestion or diffuse bleeding points of gastric mucosa and multiple redness and swelling bleeding symptoms on the inner wall were observed in the treatment group, as well as immune cell infiltration was found in HE staining, but no such phenomenon was observed in the control group. In order to explore the molecular basis of changes in MPTP induced gastric mucosa injury, the transcriptome and proteome data of gastric mucosa were analyzed. We observed significant differences in mRNA and protein expression levels under the influence of MPTP. The changes in mRNA and proteins are related to increased immune infiltration, cellular processes and angiogenesis. More differentially expressed genes play a role in immune function, especially the candidate genes RPL4 and ANXA1 with significant signal and core role. There are also differentially expressed genes that play a role in mucosal injury and shedding, especially candidate genes GAST and DDC with certain signaling and corresponding functions. Understanding the factors and molecular basis that affect the expression of related genes is crucial for coping with Emotionality gastric mucosa injury disease and developing new treatment methods to establish the ability to resist disease.

Prediction of stress-related gastrointestinal bleeding in patients with aneurysmal subarachnoid hemorrhage using caudate Hounsfield unit value in ASPECT score

Background

Stress-related gastrointestinal bleeding (SRGB) is one of the major complications after aneurysmal subarachnoid hemorrhage (aSAH), and it can present challenges in patient care and treatment. The aim of this study was to explore the clinical significance of the caudate Hounsfield unit (HU) value in the Alberta Stroke Program Early CT (ASPECT) score for predicting SRGB in patients with aSAH.

Methods

We retrospectively analyzed the data of 531 aSAH patients admitted to our institution between 2019 and 2022. Potential predictors of SRGB were identified using multivariate Cox regression analysis. We used a restricted cubic spline (RCS) to evaluate whether there is a nonlinear relationship between the right caudate HU value and SRGB. MaxStat analysis (titled as maximally selected rank statistics) was performed to identify the optimal cutoff point for the right caudate HU value. Another Kaplan-Meier method with the log-rank test was used to analyze the right caudate HU value in predicting the occurrence of SRGB.

Results

The incidence rate of SRGB was 17.9%. In the multivariate Cox regression analysis, the right caudate HU value was an independent predictor of SRGB [Hazard ratio (HR) = 0.913; 95% confidence interval (CI): 0.847-0.983, and p = 0.016]. The RCS indicated that the incidence of developing SRGB reduces with increasing right caudate HU values (nonlinear p = 0.78). The optimal cut-off value of the right caudate HU was 25.1.

Conclusion

Among aSAH patients, lower right caudate HU values indicated a higher risk of developing SRGB. Our findings provide further evidence for the relationship between the gastrointestinal system and the brain.

Proton pump inhibitor use and the risk for Parkinson's disease: A nationwide population-based study in Taiwan

Previous studies have shown that proton pump inhibitors (PPIs) are associated with an increased risk of dementia. However, little is known about the relationship between PPIs use and Parkinson's disease (PD). This study aimed to examine whether PPI use was associated with an increased risk of developing clinically verified PD. This used data from the Taiwan National Health Insurance Research Database for the period between 1999 and 2011, and patients with PPI use were compared with 1 to 1 propensity score-matched controls by age, sex, cohort entry year, and comorbidity. A multivariate analysis was performed using Cox proportional hazards models to estimate the association between PPI use and PD risk. Subgroup analyses according to sex, age, and comorbidities were also conducted. In total, 56,785 PPI users and 56,785 matched controls were enrolled in this study. In the PPI cohort, 366 patients developed PD during a median follow-up of 5.0 years. The incidence rate of PD was 1.48-fold higher in PPI users than in non-PPI users (90.0 vs 133.2 per 100,000 person-years), with an adjusted hazard ratio of 1.76 (95% confidence interval, 1.48-2.08). In the subgroup analysis, the adjusted risk of PD in the PPI and non-PPI cohorts increased in the subgroups regardless of age, sex, and comorbidities. The results of this retrospective, nationwide, population-based cohort study in Taiwan indicate that PPI use is associated with the risk of PD development. Further mechanistic studies on the effect of PPI on PD are needed.

Intestinal Inflammation and Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease which significantly influences the life quality of patients. The protein α-synuclein plays an important driving role in PD occurrence and development. Braak's hypothesis suggests that α-synuclein is produced in intestine, and then spreads into the central nervous system through the vagus nerve. The abnormal expression of α-synuclein has been found in inflammatory bowel disease (IBD). Intestinal inflammation and intestinal dysbiosis have been involved in the occurrence and development of PD. The present review aimed to summarize recent advancements in studies focusing on intestinal inflammation and PD, especially the mechanisms through which link intestinal inflammation and PD. The intestinal dysfunctions such as constipation have been introduced as non-motor manifestations of PD. The possible linkages between IBD and PD, including genetic overlaps, inflammatory responses, intestinal permeability, and intestinal dysbiosis, are mainly discussed. Although it is not confirmed whether PD starts from intestine, intestinal dysfunction may affect intestinal microenvironment to influence central nervous system, including the α-synuclein pathologies and systematic inflammation. It is expected to develop some new strategies in the diagnosis and treatment of PD from the aspect of intestine. It may also become an exciting direction to find better ways to regulate the composition of gut microorganism to treat PD.

Gastrointestinal Dopamine in Inflammatory Bowel Diseases: A Systematic Review

BACKGROUND

an increased prevalence of gastro-duodenal ulceration was described almost sixty years ago as prodromal to idiopathic Parkinson's disease, while duodenal ulcers have been rarely diagnosed in patients with schizophrenia. The cytoprotective role of dopamine in animal models of gastrointestinal ulcerations has also been described. Interestingly, Parkinson's disease (PD) might share common pathophysiological links with inflammatory bowel disease (IBD) as epidemiological and genetic links already suggest. Thus, the aim of our study was to review the existing literature on the role of the gastrointestinal dopaminergic system in IBD pathogenesis and progression.

METHODS

a systematic search was conducted according to the PRISMA methodology.

RESULTS

twenty-four studies satisfied the predetermined criteria and were included in our qualitative analysis. Due to different observations (cross-sectional studies) as well as experimental setups and applied methodologies (in vivo and in vitro studies) a meta-analysis could not be performed. No ongoing clinical trials with dopaminergic compounds in IBD patients were found.

CONCLUSIONS

the impairment of the dopaminergic system seems to be a significant, yet underestimated, feature of IBD, and more in-depth observational studies are needed to further support the existing preclinical data.

The Role of Pathogens and Anti-Infective Agents in Parkinson's Disease, from Etiology to Therapeutic Implications

Parkinson's disease is a debilitating neurodegenerative disorder whose etiology is still unclear, hampering the development of effective treatments. There is an urgent need to identify the etiology and provide further effective treatments. Recently, accumulating evidence has indicated that infection may play a role in the etiology of Parkinson's disease. The infective pathogens may act as a trigger for Parkinson's disease, the most common of which are hepatitis C virus, influenza virus, and Helicobacter pylori. In addition, gut microbiota is increasingly recognized to influence brain function through the gut-brain axis, showing an important role in the pathogenesis of Parkinson's disease. Furthermore, a series of anti-infective agents exhibit surprising neuroprotective effects via various mechanisms, such as interfering with α-synuclein aggregation, inhibiting neuroinflammation, attenuating oxidative stress, and preventing from cell death, independent of their antimicrobial effects. The pleiotropic agents affect important events in the pathogenesis of Parkinson's disease. Moreover, most of them are less toxic, clinically safe and have good blood-brain penetrability, making them hopeful candidates for the treatment of Parkinson's disease. However, the use of antibiotics and subsequent gut dysbiosis may also play a role in Parkinson's disease, making the long-term effects of anti-infective drugs worthy of further consideration and exploration. This review summarizes the current evidence for the association between infective pathogens and Parkinson's disease and subsequently explores the application prospects of anti-infective drugs in Parkinson's disease treatment, providing novel insights into the pathogenesis and treatment of Parkinson's disease.

Effects of Helicobacter pylori on Levodopa Pharmacokinetics

BACKGROUND

Infection with Helicobacter pylori seems overrepresented in Parkinson's disease. Clinical observations suggest a suboptimal treatment effect of levodopa in Helicobacter positive patients.

OBJECTIVE

Describe and explain the connection between a Helicobacter pylori infection of the upper gut and changes in pharmacokinetics of oral levodopa treatment in Parkinson's disease.

METHODS

PubMed, Google Scholar, and Cross Reference search was done using the key words and combined searches: Bioavailability, drug metabolism, dyskinesia, Helicobacter, L-dopa, levodopa, motor control, pharmacodynamics, pharmacokinetics, prevalence, unified Parkinson's disease rating scale.

RESULTS

The prevalence of Helicobacter pylori in Parkinson's disease patients is reported to be about 1.6-fold higher than in a control population in some studies. Helicobacter has therefore been assumed to be linked to Parkinson's disease, but the mechanism is unclear. As regards symptoms and treatment, patients with Parkinson's disease on levodopa therapy and with Helicobacter pylori infection display worse motor control than those without Helicobacter infection. Eradication of the infection improves levodopa response in Parkinson's disease, likely as a consequence of an increased oral pre-systemic bioavailability of levodopa, likely to be explained by reduced Helicobacter-dependent levodopa consumption in the stomach. In addition, small intestinal bacterial overgrowth may also have an impact on the therapeutic setting for levodopa treatment but is less well established.

CONCLUSION

Eradication of Helicobacter pylori improves levodopa bioavailability resulting in improved motor control. Eradication of Helicobacter should be considered in patients with poor symptomatic control and considerable motor fluctuations.

The Spectrum of Helicobacter-Mediated Diseases

Helicobacter pylori is the leading cause of peptic ulcer disease. The infection has been implicated in more than 75% of duodenal ulcer cases and 17% of gastric ulcer cases. H. pylori has been classified as a human carcinogen, since it is the main cause of distal gastric adenocarcinoma and B cell mucosa-associated lymphoid tissue lymphoma. Evidence also links H. pylori with extragastric conditions including iron deficiency anemia, idiopathic thrombocytopenic purpura, and vitamin B₁₂ deficiency. Studies indicate that H. pylori may be protective against other conditions of the gastrointestinal tract (e.g., reflux esophagitis and related pathologies) and elsewhere in the body (e.g., asthma). The infection is asymptomatic in the vast majority of cases; more serious outcomes occur in only 10-15% of infected individuals. Despite extensive research over the past 3 decades, there is no effective vaccine, and the circumstances leading to disease development remain unclear. In addition, there is now a growing prevalence of antimicrobial resistance in H. pylori. This review discusses these important issues.

Role of Helicobacters in Neuropsychiatric Disease: A Systematic Review in Idiopathic Parkinsonism

Interest in an aetiopathogenic role for Helicobacter in neuropsychiatric diseases started with idiopathic parkinsonism (IP), where the cardinal signs can be assessed objectively. This systematic review, using an EMBASE database search, addresses Oxford Centre for Evidence-Based Medicine based questions on the inter-relationship of Helicobacter and IP, the benefits of eradicating Helicobacter in IP and the outcome of not treating. The search strategy was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines: 21 of 204 articles met the inclusion criteria. The results show that the assumption that any benefit of Helicobacter eradication results from improved levodopa bioavailability is unjustified. The inter-relationship between Helicobacter and IP is well-established. H. pylori virulence markers (associated with autoimmunity and immune tolerance) influence the risk, severity and progression of IP. The birth cohort effect for virulence marker antibodies, seen in controls, is obliterated in IP, suggesting causality. Successful H. pylori eradication in IP is disease-modifying (even in anti-parkinsonian treatment-naïve patients) but not preventive. Hypokinesia regresses with eradication and overall motor severity lessens. Eradication may influence gastrointestinal microbiota adversely, unlocking the next stage in the natural history, the development of rigidity. Failed eradication worsens hypokinesia, as does the presence/persistence of H. pylori at molecular level only. Adequate prognostic assessment of the consequences of not treating Helicobacter, for IP, is prevented by a short follow-up. We conclude that Helicobacter is a pathophysiological driver of IP.

Infectious Etiologies of Parkinsonism: Pathomechanisms and Clinical Implications

Extensive research in recent decades has expanded our insights into the pathogenesis of Parkinson's disease (PD), though the underlying cause remains incompletely understood. Neuroinflammation have become a point of interest in the interconnecting areas of neurodegeneration and infectious diseases. The hypothesis concerning an infectious origin in PD stems from the observation of Parkinson-like symptoms in individuals infected with the influenza virus who then developed encephalitis lethargica. The implications of infectious pathogens have later been studied in neuronal pathways leading to the development of Parkinsonism and PD, through both a direct association and through synergistic effects of infectious pathogens in inducing neuroinflammation. This review explores the relationship between important infectious pathogens and Parkinsonism, including symptoms of Parkinsonism following infectious etiologies, infectious contributions to neuroinflammation and neurodegenerative processes associated with Parkinsonism, and the epidemiologic correlations between infectious pathogens and idiopathic PD.

Inflammatory Bowel Diseases and Parkinson's Disease

The etiology of Parkinson's disease (PD) is multifactorial, with genetics, aging, and environmental agents all a part of the PD pathogenesis. Widespread aggregation of the α-synuclein protein in the form of Lewy bodies and Lewy neurites, and degeneration of substantia nigra dopamine neurons are the pathological hallmarks of PD. Inflammatory responses manifested by glial reactions, T cell infiltration, and increased expression of inflammatory cytokines, as well as other toxic mediators derived from activated glial cells, are currently recognized as prominent features of PD. Experimental, clinical and epidemiological data suggest that intestinal inflammation contributes to the pathogenesis of PD, and the increasing number of studies suggests that the condition may start in the gastrointestinal system years before any motor symptoms develop. Patients with inflammatory bowel disease (IBD) have a higher risk of developing PD compared with non-IBD individuals. Gene association study has found a genetic link between IBD and PD, and an evidence from animal studies suggests that gut inflammation, similar to that observed in IBD, may induce loss of dopaminergic neurons. Based on preclinical models of PD, it is suggested that the enteric microbiome changes early in PD, and gut infections trigger α-synuclein release and aggregation. In this paper, the possible link between IBD and PD is reviewed based on the available literature. Given the potentially critical role of gastrointestinal pathology in PD pathogenesis, there is reason to suspect that IBD or its treatments may impact PD risk. Thus, clinicians should be aware of PD symptoms in IBD patients.

H. pylori and Parkinson's disease: Meta-analyses including clinical severity

The exact etiology of Parkinson's disease (PD) remains unclear. Some evidence supports Helicobacter pylori infection as a trigger or driving event, but detection and eradication of H. pylori are not part of PD management. The aims of this case-control study and meta-analysis were to determine (i) the prevalence of H. pylori infection in PD patients, (ii) associations between H. pylori infection and clinical status, and (iii) differences in motor status in PD patients before and after H. pylori eradication. A literature search was performed using the PubMed database. The prevalence of H. pylori infection in PD, its association with the unified Parkinson's disease rating scale (UPDRS), and the association of H. pylori eradication therapy with the UPDRS-III score were determined by calculating the odds ratios (OR) and the standardized mean differences (SMD) with 95% confidence intervals (CI). Fixed- and random-effects models were applied. Ten studies were included in the first meta-analysis (5043 PD patients, 23,449 HCs); H. pylori infection prevalence was higher in PD patients than in HCs [OR (95% CI): 1.47 (1.27, 1.70), P_z<0.00001]. In seven studies reporting UPDRS scores (150 H. pylori infected, 228 non-infected PD patients), there was a significant association between H. pylori infection and mean UPDRS scores [SMD (95% CI): 0.33 (0.12, 0.54), P_z = 0.003]. Regarding H. pylori eradication, in five studies (90 PD patients), there was a significant reduction in UPDRS-III scores after treatment [SMD (95% CI): 6.83 (2.29, 11.38), P_z = 0.003]. In conclusion, the present meta-analysis revealed a higher prevalence of H. pylori infection in PD patients suggesting that H. pylori may contribute to PD pathophysiology. In addition, the significantly lower UPDRS scores in non-infected PD patients and in patients after H. pylori eradication therapy demonstrate that the infection may deteriorate the clinical severity of the disease.

Stomaching the Possibility of a Pathogenic Role for Helicobacter pylori in Parkinson's Disease

While a small subset of Parkinson's disease cases have genetic causes, most cases are sporadic and may have an environmental contributor that has largely remained enigmatic. Remarkably, gastrointestinal symptoms in PD patients serve as a prodrome for the eventual motor dysfunctions. Herein, we review studies exploring a possible link between the gastric human pathogen Helicobacter pylori and PD. We provide plausible and testable hypotheses for how this organism might contribute to PD: 1) a toxin(s) produced by the bacteria; 2) disruption of the intestinal microbiome; 3) local inflammation that crosses the gut-brain axis, leading to neuroinflammation; and 4) manipulation of the pharmacokinetics of the PD drug levodopa by H. pylori, even in those not receiving exogenous levodopa. Key findings are: 1) people with PD are 1.5-3-fold more likely to be infected with H. pylori than people without PD; 2) H. pylori-infected PD patients display worse motor functions than H. pylori-negative PD patients; 3) eradication of H. pylori improves motor function in PD patients over PD patients whose H. pylori was not eradicated; and 4) eradication of H. pylori improves levodopa absorption in PD patients compared to that of PD patients whose H. pylori was not eradicated. Evidence is accumulating that H. pylori has a link with PD, but the mechanism is unclear. Future work should explore the effects of H. pylori on development of PD in defined PD animal models, focusing on the roles of H. pylori toxins, inflammation, levodopa absorption, and microbiome dysbiosis.

Meta-analysis: Association of Helicobacter pylori infection with Parkinson's diseases

BACKGROUND

The results from observational studies on the relationship between helicobacter pylori (H. pylori) infection and Parkinson's disease remain controversial. A meta-analysis was conducted to evaluate the association between helicobacter pylori infection and Parkinson's disease.

METHODS

A comprehensive literature search was performed on relevant studies published from January 1983 to January 2017 in PubMed, Web of Science and EMBASE databases. The fixed or random effects model was used to pool the odds ratio with 95% confidence interval from individual studies. Publication bias was estimated by Egger's test and the funnel plot.

RESULTS

Eight eligible studies involving 33 125 participants were included in this meta-analysis. Compared with the no helicobacter pylori infected person, the pooled odds ratio of Parkinson's disease in helicobacter pylori infected person was 1.59 (95% confidence interval: 1.37-1.85). In subgroup analyzes, the combined odds ratios were 1.96 (1.23-3.12) in Asia, 1.55 (1.32-1.82) in Europe, 1.59 (1.35-1.88) in case-control studies, 1.56 (1.01-2.39) in cross-sectional studies, 1.56 (1.32-1.85) in studies with confounders adjusted, and 1.71 (1.21-2.43) in studies with no confounder adjusted, respectively.

CONCLUSIONS

This meta-analysis indicated that H. pylori infection might be associated with the risk of Parkinson's disease.

Selye's general adaptation syndrome: stress-induced gastro-duodenal ulceration and inflammatory bowel disease

Hans Selye in a note to Nature in 1936 initiated the field of stress research by showing that rats exposed to nocuous stimuli responded by way of a 'general adaptation syndrome' (GAS). One of the main features of the GAS was the 'formation of acute erosions in the digestive tract, particularly in the stomach, small intestine and appendix'. This provided experimental evidence for the view based on clinical data that gastro-duodenal (peptic) ulcers could be caused by stress. This hypothesis was challenged by Marshall and Warren's Nobel Prize (2005)-winning discovery of a causal association between Helicobacter pylori and peptic ulcers. However, clinical and experimental studies suggest that stress can cause peptic ulceration in the absence of H. pylori Predictably, the etiological pendulum of gastric and duodenal ulceration has swung from 'all stress' to 'all bacteria' followed by a sober realization that both factors play a role, separately as well as together. This raises the question as to whether stress and H. pylori interact, and if so, how? Stress has also been implicated in inflammatory bowel disease (IBD) and related disorders; however, there is no proof yet that stress is the primary etiological trigger for IBD. Central dopamine mechanisms seem to be involved in the stress induction of peptic ulceration, whereas activation of the sympathetic nervous system and central and peripheral corticotrophin-releasing factor appears to mediate stress-induced IBD.

Multicomponent, multitarget integrated adjustment - Metabolomics study of Qizhiweitong particles curing gastrointestinal motility disorders in mice induced by atropine

ETHNOPHARMACOLOGICAL RELEVANCE

Qizhiweitong particles (QZWT) which is derived from the Sinisan decoction in Shang Han Za Bing Lun, composed of Bupleurum chinenis, Paeonia obovata, Citrus aurantium L., Glycyrrhiza uralensis Fisch., Cyperus rotundus and Rhizoma Corydalis is a traditional Chinese medicine (TCM) treating gastrointestinal diseases. It have been used in clinical for years. It have been used in clinical for years. According to previous research, Bupleurum chinenis, Citrus aurantium, Cyperus rotundus in QZWT play the role of promoting gastric peristalsis, which consist of complex chemical constituents. The aim of this study is to probe the multiple effective components with gastrointestinal prokinetic efficacy in QZWT and investigate the multitarget integrated adjustment mechanism of QZWT curing atropine-induced gastrointestinal motility dysfunction mice.

MATERIALS AND METHODS

One hundred and thirty two male mice were randomly divided into 11 groups, including control group, model group, Domperidone group, Mosapride group, QZWT group and six components groups. With gastric retention rate, rate of small intestine propulsion, serum content of GAS and MTL as indexes to evaluate the curing effect on gastrointestinal movement disorders caused by atropine in mice. A serum metabonomics method based on the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) had been established to investigate the mechanism of QZWT and these components, and PCA and PLS-DA have been used to distinguish different groups and found potential biomarkers.

RESULTS

Four components from six present good prokinetic effects, including Bupleurum Polysaccharide, Citrus aurantium flavonoid, Citrus aurantium essential oil and Cyperus rotundus flavonoids. These components and QZWT regulate 5 potential biomarkers in the body, and primarily involved in 5 metabolic pathways. These potential biomarkers possess direct or indirect connections, each biomarker regulated by multiple components, each component adjusting multiple targets, and QZWT is nearly the sum of its components.

CONCLUSIONS

This experiment deepened our understanding of insufficient gastrointestinal dynamics, confirmed that QZWT treating gastrointestinal disorders was through multicomponent, multitarget ways. These results fully reflect the multiple targets synergy characteristics of TCM.

Quantifying rigidity of Parkinson's disease in relation to laxative treatment: a service evaluation

Aim

To estimate whether laxatives prescribed for constipation in Parkinson's disease (PD) could moderate rigidity. Constipation predates diagnosis of PD by decades. Deposition of misfolded protein may begin in the gut, driven by dysbiosis. Successive antimicrobial exposures are associated with cumulative increase in rigidity, and rigidity has biological gradients on circulating leukocyte‐subset counts.

Methods

Retrospective service evaluation, in a gut/brain axis clinic, yielded an interrupted time series, relating maintenance laxative and other medication to rigidity, in consecutive outpatients identified by inclusion and exclusion criteria. Objective assessment of rigidity was used to bring greater sensitivity to change, validated against subjective gold standard (UPDRS).

Results

There were 1493 measurements of torque required to extend (flexor rigidity) and flex (extensor rigidity) the forearm in 79 PD patients over 374 person‐years. Both were strongly associated with UPDRS (P < 0.001 and P = 0.008, respectively). Before exhibition of laxative, flexor rigidity increased by 6% (95% CI 1, 10) per year, plateauing at −2% (−4, 1) per year after, with no shift at initiation. Change in slope was significant (P = 0.002), and manifest in those naïve to antiparkinsonian medication. The change was replicated for individual laxative classes (bulk, osmotic, enterokinetic). There was no temporal change in extensor rigidity. Limited experience with a quanylate cyclase‐C receptor agonist (17 patients, 6 person‐years) indicated a large and significant step down in flexor and extensor rigidity, of 19% (1, 34) and 16% (6, 24) respectively (P = 0.04 and <0.001).

Conclusions

Maintenance laxative usage was associated with apparent stemming of the temporal increase in rigidity in PD, adding to indicative evidence of a continuing role of gastrointestinal dysbiosis in pathogenesis.

Augmentation of Autoantibodies by Helicobacter pylori in Parkinson's Disease Patients May Be Linked to Greater Severity

Parkinson's disease (PD) is the second most common chronic and progressive neurodegenerative disorder. Its etiology remains elusive and at present only symptomatic treatments exists. Helicobacter pylori chronically colonizes the gastric mucosa of more than half of the global human population. Interestingly, H. pylori positivity has been found to be associated with greater of PD motor severity. In order to investigate the underlying cause of this association, the Sengenics Immunome protein array, which enables simultaneous screening for autoantibodies against 1636 human proteins, was used to screen the serum of 30 H. pylori-seropositive PD patients (case) and 30 age- and gender-matched H. pylori-seronegative PD patients (control) in this study. In total, 13 significant autoantibodies were identified and ranked, with 8 up-regulated and 5 down-regulated in the case group. Among autoantibodies found to be elevated in H. pylori-seropositive PD were included antibodies that recognize Nuclear factor I subtype A (NFIA), Platelet-derived growth factor B (PDGFB) and Eukaryotic translation initiation factor 4A3 (eIFA3). The presence of elevated autoantibodies against proteins essential for normal neurological functions suggest that immunomodulatory properties of H. pylori may explain the association between H. pylori positivity and greater PD motor severity.

Peripheral aetiopathogenic drivers and mediators of Parkinson's disease and co-morbidities: role of gastrointestinal microbiota

We seek an aetiopathogenic model for the spectrum of Parkinson's disease (PD), functional bowel disease, depression and cognitive impairment. The adopted concept is that systemic immuno-inflammatory processes mediate neuro-inflammation. The model would be based on phenotype, exposome (including gastrointestinal microbiome), milieu (immuno-inflammatory and metabolome), human genetics and their interactions. It would enable a patient's position, to be understood in terms of drivers, perpetuators and mediators, and a future position, with and without intervention, predicted. Even the cardinal facets of PD may have different drivers: halting one may allow escape down subordinate pathways. Peptic ulceration is prodromal to PD. In our randomised placebo-controlled trial, hypokinesia improved over the year following biopsy-proven Helicobacter pylori eradication and rigidity worsened. This was independent of any (stable, long t½) antiparkinsonian medication. There are pointers to an autoimmune process: for example, surveillance-confirmed hypokinesia effect was indication specific. During surveillance, successive antimicrobial courses, other than for Helicobacter, were associated with cumulative increase in rigidity. Exhibiting laxatives appeared to stem the overall temporal increase, despite antiparkinsonian medication, in rigidity. Thus, intestinal dysbiosis may be a major source of bystander neuronal damage. There are biological gradients of objective measures of PD facets on circulating inflammatory markers and leucocyte subset counts. Moreover, lactulose hydrogen breath test positivity for small-intestinal bacterial overgrowth (present in two thirds of PD patients) is associated with the same subsets: higher natural killer and total CD4+ counts and lower neutrophils. With greater aetiopathogenic understanding, relatively low cost and on-the-shelf medication could have a major impact. A new generation of animal models, based on the gut microbiome, is envisaged.

Eradication of Helicobacter pylori infection improves levodopa action, clinical symptoms and quality of life in patients with Parkinson's disease

BACKGROUND

Previous studies have demonstrated a higher prevalence of Helicobacter pylori (H. pylori) infection in patients with Parkinson's disease (PD) compared to controls. H. pylori infection affects levodopa absorption and its eradication significantly improves clinical response to levodopa. Here, we studied the prevalence of H. pylori infection and its eradication effects among our PD patients.

METHODS

A prospective study involving idiopathic PD patients on levodopa therapy. 13C-urea breath test (UBT) was used to detect H. pylori. UBT-positive patients were given standard eradication therapy and followed up at 6 and 12 weeks in an open label single arm design. Repeat UBT was performed at 12 weeks. The UPDRS, PD NMQ, PD NMSS and PDQ-39 were administered at baseline and post-eradication (6 and 12 weeks). Levodopa 'onset' time and ON-duration were recorded.

RESULTS

Of 82 patients recruited, 27 (32.9%) had positive UBT. H. pylori-positive patients had significantly poorer total UPDRS (p = 0.005) and PDQ39 (p<0.0001) scores compared to H. pylori-negative patients. At 12 weeks post-eradication, the mean levodopa onset time shortened by 14 minutes (p = 0.011). The mean ON duration time increased by 56 minutes at week 6 (p = 0.041) and 38 minutes at week 12 (p = 0.035). The total UPDRS scores (p<0.0001), scores for parts II (p = 0.001), III (p<0.0001) and IV (p = 0.009) were significantly better. The total PDQ-39 scores (p = 0.001) and subdomains mobility (p = 0.002), ADL (p = 0.001), emotional well being (p = 0.026) and stigma (p = 0.034) significantly improved. The PD NMSQ did not show significant improvement.

CONCLUSIONS

H. pylori eradication improved levodopa onset time, ON duration, motor severity and quality of life parameters. Screening and eradication of H. pylori is inexpensive and should be recommended in PD patients, particularly those with erratic response to levodopa.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02112812.

Host-microbial interactions in the metabolism of therapeutic and diet-derived xenobiotics

Our associated microbial communities play a critical role in human health and predisposition to disease, but the degree to which they also shape therapeutic interventions is not well understood. Here, we integrate results from classic and current studies of the direct and indirect impacts of the gut microbiome on the metabolism of therapeutic drugs and diet-derived bioactive compounds. We pay particular attention to microbial influences on host responses to xenobiotics, adding to the growing consensus that treatment outcomes reflect our intimate partnership with the microbial world, and providing an initial framework from which to consider a more comprehensive view of pharmacology and nutrition.

Significantly higher frequency of Helicobacter suis in patients with idiopathic parkinsonism than in control patients

BACKGROUND

There is increased proportional mortality from Parkinson's disease amongst livestock farmers. The hypokinesia of Parkinson's disease has been linked to Helicobacter pylori. H. suis is the most common zoonotic helicobacter in man.

AIM

To compare the frequency of H. suis, relative to H. pylori, in gastric biopsies of patients with idiopathic parkinsonism (IP) and controls from gastroenterology services.

METHODS

DNA extracts, archived at a Helicobacter Reference Laboratory, from IP patient and gastroenterology service biopsies were examined anonymously for H. suis, using species-specific RT-PCR.

RESULTS

Relative risk of having H. suis in 60 IP patients compared with 256 controls was 10 times greater than that of having H. pylori. In patients with IP and controls, respectively, frequencies of H. suis were 27 (exact binomial 95% C.I. 15, 38) and 2 (0, 3)%, and of H. pylori, 28 (17, 40) and 16 (12, 21)%. Excess of H. suis in IP held when only the antral or corporal biopsy was considered. Of 16 IP patients with H. suis, 11 were from 19 with proven H. pylori eradication, 3 from 17 pre-H. pylori eradication, 2 from 24 H. pylori culture/PCR-negative. Frequency was different between groups (P = 0.001), greatest where H. pylori had been eradicated. Even without known exposure to anti-H. pylori therapy, H. suis was more frequent in IP patients (5/41) than in controls (1/155) (P = 0.002). Partial multilocus sequence typing confirmed that strains from IP patients (6) and control (1) differed from RT-PCR standard strain.

CONCLUSIONS

Greater frequency of H. suis in idiopathic parkinsonism appears exaggerated following H. pylori eradication. Multilocus sequence testing comparison with porcine strains may clarify whether transmission is from pigs/porcine products or of human-adapted, H. suis-like, bacteria.

Leukocyte-subset counts in idiopathic parkinsonism provide clues to a pathogenic pathway involving small intestinal bacterial overgrowth. A surveillance study

BACKGROUND

Following Helicobacter pylori eradication in idiopathic parkinsonism (IP), hypokinesia improved but flexor-rigidity increased. Small intestinal bacterial-overgrowth (SIBO) is a candidate driver of the rigidity: hydrogen-breath-test-positivity is common in IP and case histories suggest that Helicobacter keeps SIBO at bay.

METHODS

In a surveillance study, we explore relationships of IP-facets to peripheral immune/inflammatory-activation, in light of presence/absence of Helicobacter infection (urea-breath- and/or stool-antigen-test: positivity confirmed by gastric-biopsy) and hydrogen-breath-test status for SIBO (positivity: >20 ppm increment, 2 consecutive 15-min readings, within 2h of 25G lactulose). We question whether any relationships found between facets and blood leukocyte subset counts stand in patients free from anti-parkinsonian drugs, and are robust enough to defy fluctuations in performance consequent on short t½ therapy.

RESULTS

Of 51 IP-probands, 36 had current or past Helicobacter infection on entry, 25 having undergone successful eradication (median 3.4 years before). Thirty-four were hydrogen-breath-test-positive initially, 42 at sometime (343 tests) during surveillance (2.8 years). Hydrogen-breath-test-positivity was associated inversely with Helicobacter-positivity (OR 0.20 (95% CI 0.04, 0.99), p<0.05).In 38 patients (untreated (17) or on stable long-t½ IP-medication), the higher the natural-killer count, the shorter stride, slower gait and greater flexor-rigidity (by mean 49 (14, 85) mm, 54 (3, 104) mm.s-1, 89 (2, 177) Nm.10-3, per 100 cells.μl-1 increment, p=0.007, 0.04 & 0.04 respectively, adjusted for patient characteristics). T-helper count was inversely associated with flexor-rigidity before (p=0.01) and after adjustment for natural-killer count (-36(-63, -10) Nm.10-3 per 100 cells.μl-1, p=0.007). Neutrophil count was inversely associated with tremor (visual analogue scale, p=0.01). Effect-sizes were independent of IP-medication, and not masked by including 13 patients receiving levodopa (except natural-killer count on flexor-rigidity). Cellular associations held after allowing for potentially confounding effect of hydrogen-breath-test or Helicobacter status. Moreover, additional reduction in stride and speed (68 (24, 112) mm & 103 (38, 168) mm.s-1, each p=0.002) was seen with Helicobacter-positivity. Hydrogen-breath-test-positivity, itself, was associated with higher natural-killer and T-helper counts, lower neutrophils (p=0.005, 0.02 & 0.008).

CONCLUSION

We propose a rigidity-associated subordinate pathway, flagged by a higher natural-killer count, tempered by a higher T-helper, against which Helicobacter protects by keeping SIBO at bay.

CD4+ regulatory and effector/memory T cell subsets profile motor dysfunction in Parkinson's disease

Animal models and clinical studies have linked the innate and adaptive immune system to the pathology of Parkinson’s disease (PD). Despite such progress, the specific immune responses that influence disease progression have eluded investigators. Herein, we assessed relationships between T cell phenotype and function with PD progression. Peripheral blood lymphocytes from two separate cohorts, a discovery cohort and a validation cohort, totaling 113 PD patients and 96 age- and environment-matched caregivers were examined by flow cytometric analysis and T cell proliferation assays. Increased effector/memory T cells (Tem), defined as CD45RO+ and FAS+ CD4+ T cells and decreased CD31+ and α4β7+ CD4+ T cells were associated with progressive Unified Parkinson’s Disease Rating Scale III scores. However, no associations were seen between immune biomarkers and increased age or disease duration. Impaired abilities of regulatory T cells (Treg) from PD patients to suppress effector T cell function was observed. These data support the concept that chronic immune stimulation, notably Tem activation and Treg dysfunction is linked to PD pathobiology and disease severity, but not disease duration. The association of T cell phenotypes with motor symptoms provides fresh avenues for novel biomarkers and therapeutic designs.

Central dopaminergic system and its implications in stress-mediated neurological disorders and gastric ulcers: short review

For decades, it has been suggested that dysfunction of dopaminergic pathways and their associated modulations in dopamine levels play a major role in the pathogenesis of neurological disorders. Dopaminergic system is involved in the stress response, and the neural mechanisms involved in stress are important for current research, but the recent and past data on the stress response by dopaminergic system have received little attention. Therefore, we have discussed these data on the stress response and propose a role for dopamine in coping with stress. In addition, we have also discussed gastric stress ulcers and their correlation with dopaminergic system. Furthermore, we have also highlighted some of the glucocorticoids and dopamine-mediated neurological disorders. Our literature survey suggests that dopaminergic system has received little attention in both clinical and preclinical research on stress, but the current research on this issue will surely identify a better understanding of stressful events and will give better ideas for further efficient antistress treatments.

Treatment for Helicobacter pylori infection and risk of Parkinson's disease in Denmark

BACKGROUND AND PURPOSE

It has been speculated that gastrointestinal infection with Helicobacter pylori (HP) contributes to the development of Parkinson's disease (PD). We used nationwide Danish registers to investigate this hypothesis.

METHODS

 We identified 4484 patients with a first time PD diagnosis between 2001 and 2008 from the Danish National Patient Register (DNPR) and 22, 416 population controls from the Danish Civil Registration System (CRS). Information on drug use was obtained from the National Prescription Registry (NPR). We used logistic regression to compute odds ratios (OR) for the association between treatment for HP and risk of PD.

RESULTS

Prescriptions for HP-eradication drugs and proton pump inhibitors (PPI) 5 or more years prior to the diagnosis of PD were associated with a 45% and 23% increase in PD risk, respectively. Hospitalizations and outpatient visits for gastritis and peptic/duodenal ulcers, however, were not associated with PD.

CONCLUSIONS

  Our population-based study suggests that chronic HP infections and/or gastritis contribute to PD or that these are PD-related pathologies that precede motor symptoms.

Inflammatory Animal Model for Parkinson's Disease: The Intranigral Injection of LPS Induced the Inflammatory Process along with the Selective Degeneration of Nigrostriatal Dopaminergic Neurons

We have developed an animal model of degeneration of the nigrostriatal dopaminergic neurons, the neuronal system involved in Parkinson's disease (PD). The implication of neuroinflammation on this disease was originally established in 1988, when the presence of activated microglia in the substantia nigra (SN) of parkinsonians was reported by McGeer et al. Neuroinflammation could be involved in the progression of the disease or even has more direct implications. We injected 2 μg of the potent proinflammatory compound lipopolysaccharide (LPS) in different areas of the CNS, finding that SN displayed the highest inflammatory response and that dopaminergic (body) neurons showed a special and specific sensitivity to this process with the induction of selective dopaminergic degeneration. Neurodegeneration is induced by inflammation since it is prevented by anti-inflammatory compounds. The special sensitivity of dopaminergic neurons seems to be related to the endogenous dopaminergic content, since it is overcome by dopamine depletion. Compounds that activate microglia or induce inflammation have similar effects to LPS. This model suggest that inflammation is an important component of the degeneration of the nigrostriatal dopaminergic system, probably also in PD. Anti-inflammatory treatments could be useful to prevent or slow down the rate of dopaminergic degeneration in this disease.

Peripheral inflammation increases the damage in animal models of nigrostriatal dopaminergic neurodegeneration: possible implication in Parkinson's disease incidence

Inflammatory processes described in Parkinson's disease (PD) and its animal models appear to be important in the progression of the pathogenesis, or even a triggering factor. Here we review that peripheral inflammation enhances the degeneration of the nigrostriatal dopaminergic system induced by different insults; different peripheral inflammations have been used, such as IL-1β and the ulcerative colitis model, as well as insults to the dopaminergic system such as 6-hydroxydopamine or lipopolysaccharide. In all cases, an increased loss of dopaminergic neurons was described; inflammation in the substantia nigra increased, displaying a great activation of microglia along with an increase in the production of cytokines such as IL-1β and TNF-α. Increased permeability or disruption of the BBB, with overexpression of the ICAM-1 adhesion molecule and infiltration of circulating monocytes into the substantia nigra, is also involved, since the depletion of circulating monocytes prevents the effects of peripheral inflammation. Data are reviewed in relation to epidemiological studies of PD.

Ulcerative colitis exacerbates lipopolysaccharide-induced damage to the nigral dopaminergic system: potential risk factor in Parkinson`s disease

Peripheral inflammation could play a role in the origin and development of certain neurodegenerative disorders. To ascertain this possibility, a model of dopaminergic neurodegeneration based on the injection of the inflammatory agent lipopolysaccharide (LPS) within the substantia nigra was assayed in rats with ulcerative colitis (UC) induced by the ingestion of dextran sulphate sodium. We found an increase in the levels of inflammatory markers from serum (tumor necrosis factor-α, IL-1β, IL-6 and the acute phase protein C-reactive protein) and substantia nigra (tumor necrosis factor-α, IL-1β, IL-6, inducible nitric oxide synthase, intercellular adhesion molecule-1, microglial and astroglial populations) of rats with UC, as well as an alteration of the blood-brain barrier permeability and the loss of dopaminergic neurons. UC reinforced the inflammatory and deleterious effects of LPS. On the contrary, clodronate encapsulated in liposomes (ClodLip), which depletes peripheral macrophages, ameliorated the effect of LPS and UC. Peripheral inflammation might represent a risk factor in the development of Parkinson's disease.

Differential effect of Helicobacter pylori eradication on time-trends in brady/hypokinesia and rigidity in idiopathic parkinsonism

BACKGROUND

We examine the effect of eradicating Helicobacter in idiopathic parkinsonism (IP). Marked deterioration, where eradication-therapy failed, prompted an interim report in the first 20 probands to reach de-blinding. The null-hypothesis, "eradication has no effect on principal outcome, mean stride length at free-walking speed," was rejected. We report on study completion in all 30 who had commenced post-treatment assessments.

METHODS

This is a randomized, placebo-controlled, parallel-group efficacy study of eradicating biopsy-proven (culture and/or organism on histopathology) Helicobacter pylori infection on the time course of facets of IP, in probands taking no, or stable long-t(1/2), anti-parkinsonian medication. Persistent infection at de-blinding (scheduled 1-year post-treatment) led to open active eradication-treatment.

RESULTS

Stride length improved (73 (95% CI 14-131) mm/year, p = .01) in favor of "successful" blinded active over placebo, irrespective of anti-parkinsonian medication, and despite worsening upper limb flexor rigidity (237 (57-416) Nm x 10(-3)/year, p = .01). This differential effect was echoed following open active, post-placebo. Gait did not deteriorate in year 2 and 3 post-eradication. Anti-nuclear antibody was present in all four proven (two by molecular microbiology only) eradication failures. In the remainder, it marked poorer response during the year after eradication therapy, possibly indicating residual "low-density" infection. We illustrate the importance of eradicating low-density infection, detected only by molecular microbiology, in a proband not receiving anti-parkinsonian medication. Stride length improved (424 (379-468) mm for 15 months post-eradication, p = .001), correction of deficit continuing to 3.4 years. Flexor rigidity increased before hydrogen-breath-test positivity for small intestinal bacterial overgrowth (208 (28-388) Nm x 10(-3), p = .02), increased further during (171 (67-274), p = .001) (15-31 months), and decreased (136 (6-267), p = .04) after restoration of negativity (32-41 months).

CONCLUSION

Helicobacter is an arbiter of progression, independent of infection-load.

Blood profile holds clues to role of infection in a premonitory state for idiopathic parkinsonism and of gastrointestinal infection in established disease

The two-stage neuroinflammatory process, containment and progression, proposed to underlie neurodegeneration may predicate on systemic inflammation arising from the gastrointestinal tract. Helicobacter infection has been described as one switch in the pathogenic-circuitry of idiopathic parkinsonism (IP): eradication modifies disease progression and marked deterioration accompanies eradication-failure. Moreover, serum Helicobacter-antibody-profile predicts presence, severity and progression of IP. Slow gastrointestinal-transit precedes IP-diagnosis and becomes increasingly-apparent after, predisposing to small-intestinal bacterial-overgrowth (SIBO). Although IP is well-described as a systemic illness with a long prodrome, there has been no comprehensive overview of the blood profile. Here, it is examined in relation to Helicobacter status and lactulose-hydrogen-breath-testing for SIBO.

A robust finding of reduced lymphocyte count in 126 IP-probands and 79 spouses (without clinically-definite IP), compared with that in 381 controls (p < 0.001 in each case), was not explained by Helicobacter-status or breath-hydrogen. This complements a previous report that spouses were 'down-the-pathway' to 'clinically-definite' disease. In 205 other controls without clinically-definite IP, there were strong associations between sporadic cardinal features and immunoglobulin class concentration, not explained by Helicobacter-status. Premonitory states for idiopathic parkinsonism associated with relative lymphopenia, higher serum immunoglobulin concentrations and evidence of enteric-nervous-system damage may prove viral in origin.

Although only 8% of the above 79 spouses were urea-breath-test-positive for Helicobacter, all 8 spouses with clinically-definite IP were (p < 0.0001). Transmission of a 'primer' to a Helicobacter-colonised recipient might result in progression to the diagnostic threshold.

Twenty-five percent of the 126 probands were seropositive for anti-nuclear autoantibody. In 20 probands, monitored before and serially after anti-Helicobacter therapy, seropositivity marked a severe hypokinetic response (p = 0.03). It may alert to continuing infection, even at low-density. Hyperhomocysteinemia is a risk factor for dementia and depression. Serum homocysteine exceeded the target in 43% of the 126 IP-probands. It was partially explained by serum B12 (12% variance, p < 0.001), but not by Helicobacter-status (gastric-atrophy uncommon in IP) or levodopa treatment. Immune-inflammatory activation increases homocysteine production. Since an estimated 60% of probands are hydrogen-breath-test positive, SIBO, with its increased bacterial utilisation of B12, is a likely cause. Thus, two prognostic indicators in established IP fit with involvement of Helicobacter and SIBO.

Pharmacometabonomic identification of a significant host-microbiome metabolic interaction affecting human drug metabolism

We provide a demonstration in humans of the principle of pharmacometabonomics by showing a clear connection between an individual's metabolic phenotype, in the form of a predose urinary metabolite profile, and the metabolic fate of a standard dose of the widely used analgesic acetaminophen. Predose and postdose urinary metabolite profiles were determined by (1)H NMR spectroscopy. The predose spectra were statistically analyzed in relation to drug metabolite excretion to detect predose biomarkers of drug fate and a human-gut microbiome cometabolite predictor was identified. Thus, we found that individuals having high predose urinary levels of p-cresol sulfate had low postdose urinary ratios of acetaminophen sulfate to acetaminophen glucuronide. We conclude that, in individuals with high bacterially mediated p-cresol generation, competitive O-sulfonation of p-cresol reduces the effective systemic capacity to sulfonate acetaminophen. Given that acetaminophen is such a widely used and seemingly well-understood drug, this finding provides a clear demonstration of the immense potential and power of the pharmacometabonomic approach. However, we expect many other sulfonation reactions to be similarly affected by competition with p-cresol and our finding also has important implications for certain diseases as well as for the variable responses induced by many different drugs and xenobiotics. We propose that assessing the effects of microbiome activity should be an integral part of pharmaceutical development and of personalized health care. Furthermore, we envisage that gut bacterial populations might be deliberately manipulated to improve drug efficacy and to reduce adverse drug reactions.

Helicobacter hypothesis for idiopathic parkinsonism: before and beyond

We challenge the concept of idiopathic parkinsonism (IP) as inevitably progressive neurodegeneration, proposing a natural history of sequential microbial insults with predisposing host response. Proof-of-principle that infection can contribute to IP was provided by case studies and a placebo-controlled efficacy study of Helicobacter eradication. "Malignant" IP appears converted to "benign", but marked deterioration accompanies failure. Similar benefit on brady/hypokinesia from eradicating "low-density" infection favors autoimmunity. Although a minority of UK probands are urea breath test positive for Helicobacter, the predicted probability of having the parkinsonian label depends on the serum H. pylori antibody profile, with clinically relevant gradients between this "discriminant index" and disease burden and progression. In IP, H. pylori antibodies discriminate for persistently abnormal bowel function, and specific abnormal duodenal enterocyte mitochondrial morphology is described in relation to H. pylori infection. Slow intestinal transit manifests as constipation from the prodrome. Diarrhea may flag secondary small-intestinal bacterial overgrowth. This, coupled with genetically determined intense inflammatory response, might explain evolution from brady/hypokinetic to rigidity-predominant parkinsonism.

Cycad toxins, Helicobacter pylori and parkinsonism: cholesterol glucosides as the common denomenator

Understanding sporadic cases of age-dependent neurodegenerative diseases such as parkinsonism requires the evaluation of potential environmental factors. Amyotrophic lateral sclerosis-parkinsonism dementia complex (ALS-PDC), a neurological disorder in which features of parkinsonism are present and for which no consistent genetic explanation has been found, has been linked to the consumption of cycad (Cycas micronesica). Similarly, epidemiological evidence suggests an association between parkinsonism and gastric ulcer caused by Helicobacter pylori infection. While common immunological and inflammatory changes have been proposed to account for the link between parkinsonism and H. pylori infection, we propose an alternate explanation based on our work on the "cycad theory" of ALS-PDC. Recent experiments in our laboratory have identified several sterol glucosides in cycad that have neurotoxic properties in vitro and that appear to be linked to the development of neurodegenerative disease in vivo. Specifically, mice fed cycad display behavioural symptoms of parkinsonism such as reduced gait length, as well as neuropathological signs such as a loss of striatal dopaminergic (DAergic) terminals and an upregulation of the dopamine D2 receptor. These cycad-derived sterol glucosides are structurally similar to cholesterol glucosides that account for a significant part pf the lipid profile of H. pylori. We hypothesize that cholesterol glucosides arising from H. pylori infection may act as neurotoxins, promoting the degeneration of the DAergic neurons affected in parkinsonism, in a similar reaction to that which is thought to link cycad consumption and ALS-PDC. This hypothesis will be tested in future studies that will include exposing mice to purified sterol or cholestorol glucosides derived from cycad and comparing these mice behaviourally and neuropathologically to ones chronically infected with H. pylori.

Role of inflammation in gastrointestinal tract in aetiology and pathogenesis of idiopathic parkinsonism

Idiopathic parkinsonism (IP) is a common disorder, conventionally regarded as neurodegenerative. Its cardinal features, poverty and slowness of movement, muscle rigidity, postural abnormality and a characteristic tremor, are associated with loss of dopaminergic neurones in the substantia nigra of the brain. Genetic factors explain only a minority of cases, and a common toxic environmental insult remains elusive. We propose that IP is a systemic disorder resulting from a ubiquitous peripheral infection, and that only the tip of the iceberg comes to diagnosis. There is evidence for inflammatory/immune activation peripherally and in the brain. We have used statistical modelling to explore links with non-specific and specific systemic markers of inflammation/infection in IP probands, and explore whether their partners and siblings have a frank or pre-presentation parkinsonian state. Critical to this approach is continuous objective measures of the facets of IP. Hypotheses on causality and mechanism are based on the statistical models. There is pathological and clinical evidence for direct involvement of the gastrointestinal tract in IP. The candidacy of Helicobacter pylori infection as a trigger event or driving infection is relatively high. We have found that eliminating infection in late parkinsonism with cachexia, a stage usually considered intractable, can result in a U-turn. However, eradication therapy may not provide a complete solution. Persistence of antibody against cytotoxin-associated antigen (CagA), increases the predicted probability of being labelled as having parkinsonism. Evidence for autoimmunity and immunocompromise is used to build schemes for the natural history. We conclude that current classifications of neuropsychiatric disease may not prove the best with respect to defining sub-clinical disease, prophylaxis or halting progression.

Role of chronic infection and inflammation in the gastrointestinal tract in the etiology and pathogenesis of idiopathic parkinsonism. Part 3: predicted probability and gradients of severity of idiopathic parkinsonism based on H. pylori antibody profile

BACKGROUND

Eradicating Helicobacter may convert rapidly progressive idiopathic parkinsonism to quieter disease, however only a minority of probands have evidence of current infection.

AIM

To explore the cross-sectional fit of parkinsonism as an extra-alimentary consequence of Helicobacter pylori, using the serum antibody profile.

METHODS

A discriminant index for parkinsonism was based on the Western Blot pattern of IgG antibodies against electrophoretically separated H. pylori antigens in 124 subjects with idiopathic parkinsonism, 196 without. In parkinsonism, association was assessed between index and 1, anthropometric measures; 2, current and 3, increase over 4 years in hypokinetic and psychomotor/psychometric disability; and 4, a global score of current severity.

RESULTS

Predicted probability of being labeled parkinsonian was greatest with cytotoxin-associated-gene-product (CagA) positivity and vacuolating-toxin negativity (p = .03 and .004, respectively, for antibody-age interactions), and urease-B negativity (p = .03, irrespective of age). In this circumstance, the odds for parkinsonism increased fivefold by age 80 years (p = .001). Helicobacter status, according to anti-urease enzyme-linked immunosorbent assay (ELISA), did not complement the model. Gradients, of clinically relevant size, were found between index and disease burden, despite the potentially confounding effect of antiparkinsonian medication. The higher the index 1, the worse was posture, as gauged by forward displacement of occiput (p = .04), 2, the shorter mean stride-length (p = .003), longer reaction time (= .002) and lesser cognitive efficiency (= .03), 3, the greater their deterioration (p = .006, .002, and .03 respectively), and 4, the greater the overall severity of parkinsonism (< .001).

CONCLUSION

The apparent importance of H. pylori in the etiology/pathogenesis of idiopathic parkinsonism is not confined to those with evidence of current infection.

Role of chronic infection and inflammation in the gastrointestinal tract in the etiology and pathogenesis of idiopathic parkinsonism. Part 1: eradication of Helicobacter in the cachexia of idiopathic parkinsonism

BACKGROUND

Neuronal damage in idiopathic parkinsonism may be in response to ubiquitous occult infection. Since peptic ulceration is prodromal, Helicobacter is a prime candidate.

AIM

To consider the candidature of Helicobacter in parkinsonism with cachexia.

METHODS

We explore the relationship between being underweight and inflammatory products in 124 subjects with idiopathic parkinsonism and 195 controls, and present the first case-series evidence of efficacy of Helicobacter eradication, in parkinsonism advanced to the stage of cachexia.

RESULTS

Association of a low body mass index with circulating interleukin-6 was specific to parkinsonism (p = .002), unlike that with antibodies against Helicobacter vacuolating-toxin and cytotoxicity-associated gene product (p < .04). Marked reversibility in both cachexia and disability of idiopathic parkinsonism followed Helicobacter heilmannii eradication in one case, Helicobacter pylori eradication in another, follow-up being > or = 3.5 years. The latter presented with postprandial bloating, and persistent nausea: following eradication, radioisotope gastric-emptying returned towards normal, and upper abdominal symptoms regressed. Reversibility of their cachexia/disability contrasts with the outcome of anti-Helicobacter therapy where eradication repeatedly failed (one case), and in non-Helicobacter gastritis (three cases). Anti-parkinsonian medication remained constant. Intestinal absorption and barrier function were normal in all.

CONCLUSION

Categorization, according to presence or absence of Helicobacter infection, was a useful therapeutic tool in late idiopathic parkinsonism.

Role of chronic infection and inflammation in the gastrointestinal tract in the etiology and pathogenesis of idiopathic parkinsonism. Part 2: response of facets of clinical idiopathic parkinsonism to Helicobacter pylori eradication. A randomized, double-blind, placebo-controlled efficacy study

BACKGROUND

Links between etiology/pathogenesis of neuropsychiatric disease and infection are increasingly recognized.

AIM

Proof-of-principle that infection contributes to idiopathic parkinsonism.

METHODS

Randomized, double-blind, placebo-controlled efficacy study of proven Helicobacter pylori eradication on the time course of facets of parkinsonism. Intervention was 1 week's triple eradication therapy/placebos. Routine deblinding at 1 year (those still infected received open-active), with follow-up to 5 years post-eradication. Primary outcome was mean stride length at free-walking speed, sample size 56 for a difference, active vs. placebo, of 3/4 (between-subject standard deviation). Recruitment of subjects with idiopathic parkinsonism and H. pylori infection was stopped at 31, because of marked deterioration with eradication failure. Interim analysis was made in the 20 who had reached deblinding, seven of whom were receiving antiparkinsonian medication (long-t(1/2), evenly spaced) which remained unchanged.

RESULTS

Improvement in stride-length, on active (n = 9) vs. placebo (11), exceeded size of effect on which the sample size was calculated when analyzed on intention-to-treat basis (p = .02), and on protocol analysis of six weekly assessments, including (p = .02) and excluding (p = .05) those on antiparkinsonian medication. Active eradication (blind or open) failed in 4/20, in whom B-lymphocyte count was lower. Their mean time course was: for stride-length, -243 (95% CI -427, -60) vs. 45 (-10, 100) mm/year in the remainder (p = .001); for the ratio, torque to extend to flex relaxed arm, 349 (146, 718) vs. 58 (27, 96)%/ year (p < .001); and for independently rated, visual-analog scale of stance-walk videos (worst-best per individual identical with 0-100 mm), -64 vs. -3 mm from anterior and -50 vs. 11 lateral (p = .004 and .02).

CONCLUSIONS

Interim analysis points to a direct or surrogate (not necessarily unique) role of a particular infection in the pathogenesis of parkinsonism. With eradication failure, bolus release of antigen from killed bacteria could aggravate an effect of ongoing infection.

Neurodegenerative memory disorders: a potential role of environmental toxins

The hypothesis that neurotoxins may play a role in neurodegenerative disorders remains an elusive one, given that epidemiologic studies often provide conflicting results. Although these conflicting results may result from methodological differences within and between studies, the complexity of chemical disruption of the central nervous system cannot be ignored in attempts to evaluate this hypothesis in different neurodegenerative disorders. Spencer provides a detailed review of the complex processes involved in defining the neurotoxic potential of naturally occurring and synthetic agents. Even concepts such as exposure and dose, as often reported in studies attempting to evaluate the risk imparted by a potential compound, can be deceptive. For example, although dose reflects "that amount of chemical transferred to the exposed subject", factors such as time and concentration in the organism, the ability to access the central nervous system, and how a compound reaches the central nervous system (routes of administration) or secondarily affects other organ systems leading to central nervous system disruption are clearly important to the concept of neurotoxic risk in neurodegenerative disorders. These factors would appear to explain the observed disagreements between studies using animal or neuronal models of neurotoxicity and population-based studies in humans. The importance of these factors and how a potential neurotoxin is investigated are clearly seen in the data on AD and aluminum. In contrast, the impact of MTPT on the central nervous system is more direct and compelling. Added complexity in the study of neurotoxins in human neurodegeneration is derived from data showing that agents may have additive, potentiating, synergistic, or antagonistic effects. Therefore, data from studies evaluating EMF risks could be readily confounded by the presence or absence of heavy metals (eg, arc welding). Other factors that may conceal neurotoxic causes for a given disorder focus on additional features such as genetic predispositions, physiologic changes that occur in aging, and even nutritional status that can support or hinder the affect of a given agent on the central nervous system. Finally, many studies that investigate exposure risk do not readily incorporate the five criteria proposed by Schaumburg for establishing causation. For example, if we apply Schaumburg's first criterion, epidemiologic studies often determines the presence of an agent through history, yet they cannot readily confirm exposure based on environmental or clinical chemical analyses to fulfill this criterion for causation. Additional limitations in research design along with the populations and methods that are sued to study neurotoxins in human neurodegenerative disorders often fail to meet other criteria such as linking the severity and onset with duration and exposure level. Therefore, although studies of agents such as MTPT provide compelling models of neurotoxins and neurodegeneration in humans, disorders such as ALS, PD, and particularly AD will require additional effort if research is to determine the contribution (presence or absence) of neurotoxins to these neurologic disorders.

Effect of Acanthopanax senticosus Harms on biogenic monoamine levels in the rat brain

The extract of the stem bark of Acanthopanax senticosus Harms (ASH) is known to have healing and protective effects on stress-induced disturbance of mental status. We have analysed whether a single or chronic (2 week) administration of ASH can affect concentrations of noradrenaline (NA), dopamine (DA) and their metabolites in the normal rat brain. A single p.o. administration of ASH elevated the NA and DA levels in the whole brain of rats in a dose-dependent manner. A single or 2 week administration of ASH (500 mg/kg) showed a marked increase in the DA level only in the striatum. However, NA levels were increased by a single dose of ASH in a wide range of brain regions such as the cortex, hypothalamus, striatum, hippocampus, substantia nigra and pons. When administered for 2 weeks no increase in NA levels was seen in these brain regions, except for an increase in the frontal cortex and anterior hypothalamus. The present results suggest that ASH may act by regulating NA and DA levels in specific brain regions related to stress response and Parkinson's disease.

Susceptibility of dopamine D5 receptor targeted mice to cysteamine

BACKGROUND

Recently we demonstrated that gastric mucosa of rats can synthesize, store and release dopamine. Out of five different subtypes, mRNA of D5 (=D1b) dopamine receptor is very abundant in the gastric epithelium. D1 receptor selective dopamine agonists have been shown to protect against experimental gastro-duodenal lesions.

AIMS

To test the hypothesis that protective effects of dopamine involve D5 receptors, mucosal lesions were induced in D5 receptor deficient (KO) and wild-type (WT) mice using cysteamine. Morphology and gastric acid secretion of D5 KO mice were also studied.

METHODS

Single doses of 600 mg/kg, 300 mg/kg cysteamine or vehicle were administered subcutaneously to fasted animals. After 24 h, number and severity of gastro-duodenal lesions were analyzed. Basal and histamine-induced maximal gastric acid output were measured by a stomach-sac wash-through method.

RESULTS

All the KOs in the 600 mg/kg cysteamine group died within 4 h showing symptoms of toxicity while three out of four WTs survived (P<0.05). Mortality after 300 mg/kg cysteamine was significantly higher in KOs versus the WTs: 6/14 versus 2/11, P<0.05. Gastric lesion-index was also significantly higher in KOs (median, middle quartile): four (3-9) versus 0 (0-0), P<0.05. Duodenal lesions did not develop from this single dose of cysteamine in either genotype. Basal and histamine-induced maximal gastric acid output were comparable in the two genotypes.

CONCLUSIONS

This study demonstrates that loss of D5 receptor causes mucosal vulnerability and increased toxicity of cysteamine in genetically manipulated mice. Thus, D5 receptor subtype is indeed likely to be involved in protective effects of dopamine in the stomach.

Parkinsonism: differential age-trend in Helicobacter pylori antibody

BACKGROUND

Parkinsonism is associated with prodromal peptic ulceration. Dopamine antagonists provoke experimental ulcer, dopaminergic agents protect, and might inhibit growth of Helicobacter pylori.

OBJECTIVE

To describe the relationship between H. pylori serology and parkinsonism.

METHODS

Serum H. pylori anti-urease-IgG antibody was measured in 105 people with (idiopathic) parkinsonism, 210 without, from same locality. None had received specific eradication therapy.

RESULTS

Controls showed a birth-cohort effect: antibody titre rose from 30 to 90 years (P < 0. 001). Parkinsonism obliterated this (disease status. age interaction, P < 0.05), the differential age trend not being attributable to social class. Those with diagnosed parkinsonism were more likely to be seropositive (odds ratio 2.04 (95% CI: 1.04, 4.22) P < 0.04) before 72.5 years. Overall, titre fell (P=0.01) by 5 (1, 9)% per unit increase in a global, 30-point rating (median 14 (interquartile range 10.5, 17)) of disease severity. No individual category of anti-parkinsonian medication (92% taking) had a differential lowering effect.

CONCLUSIONS

Higher prevalence of seropositivity in parkinsonism, before 8th decade, may be due to host susceptibility/reaction, or, conversely, infection with particular H. pylori strain(s) lowering dopaminergic status. Absence of a birth cohort effect in parkinsonism, despite similar social class representation, may be consequent on eradication, spontaneous (gastric atrophy) or by anti-parkinsonian medication.

Link between Helicobacter pylori infection and idiopathic parkinsonism

The conventional concept for an environmental cause of idiopathic parkinsonism is an insult (e.g. neurotoxin or encephalitis), superimposed on age-related attrition of nigral dopaminergic neurons, and temporally remote from neurological diagnosis. To the contrary, we describe the fit of Helicobacter pylori. This commonest of known bacterial infections, usually acquired in childhood, persists, and has been linked with peptic ulcer/non-ulcer dyspepsia, immunosuppression and autoimmunity. Acquired immunosuppression, predisposing to auto-immunity, is assessed as a model for the pathogenesis of parkinsonism and parkinsonian-like attributes of ageing. Eradication of a trigger has potential to change the approach to parkinsonism, just as it did to peptic ulcer. The tenet of inevitable age-related attrition of dopaminergic neurons may also require revision.

Aluminum-containing antacids as a cause of idiopathic Parkinson's disease

The mechanism of pathogenesis of idiopathic Parkinson's disease (PD) is unknown. In a study of 200 PD patients and 200 age- and sex-matched controls, Strang noted a marked and statistically significant higher incidence of ulcers (diagnosed by X-ray or surgery) in the PD patients compared to the controls (14% to 4%). These results have been discussed but never explained. Studies have shown increased concentrations of aluminum in the substantia nigra of PD patients compared to controls. Aluminum is thought to be a cellular toxin. Here I suggest that aluminum, and in particular aluminum-containing antacids may contribute to the pathogenesis of idiopathic PD.