Parkinson's disease in Africa: A systematic review of epidemiologic and genetic studies.

Parkinson's disease (PD) occurs worldwide, but little is known about PD in Africa. We systematically reviewed publications on PD in Africa, with emphasis on epidemiologic and genetic studies. Articles published between 1944 and December 2004 were identified using several strategies. The studies emanated from 13 African countries (Kenya, Uganda, Tanzania, Ethiopia, Nigeria, Senegal, Ghana, Togo, Libya, Tunisia, Algeria, Zimbabwe, and South Africa). The publications fell into four categories: clinical series (n = 17), prevalence studies (n = 7), incidence studies (n = 1), and genetic studies (n = 3). The clinical series documented the occurrence of PD in Africa and described its clinical characteristics. The prevalence studies suggested some intracontinental geographic variation in PD prevalence. Overall, the prevalence figures and the incidence rates of PD in Africa appeared lower than those reported for European and North American populations. Few genetic studies of PD have been reported from Africa, and none in blacks. There are no case-control or cohort studies of PD reported from Africa. This review provides a summary of PD research in Africa over the past 60 years and highlights the information gaps and potential areas for future research.     

Case-control study of the alpha-synuclein interacting protein gene and Parkinson's disease.

We conducted a case-control study of the alpha-synuclein-interacting protein gene (SNCAIP, also known as synphilin-1) and Parkinson's disease (PD). A total of 319 PD cases and 195 controls were genotyped for four SNCAIP variants, including a microsatellite repeat in intron 4 and three restriction fragment length polymorphisms (RFLP) proximal to the 5' terminal of exons 1, 4, and 6. None of the variants were found associated with PD overall. Global score statistics were not significant for four, three, and two loci haplotypes. All four loci were in linkage disequilibrium for cases, controls, or both groups combined (P < 0.0001). Recursive partitioning showed no interactions between variants of the SNCAIP gene and variants of the alpha-synuclein gene (SNCA) or the parkin (PARK2) gene.     

Complex interactions in Parkinson's disease: a two-phased approach.

The identification of pathogenic mutations in the three genes alpha-synuclein, parkin, and ubiquitin carboxy-terminal hydrolase L1 (UCHL1) has elucidated the ubiquitin proteasome system (UPS) and its potential role as a causal pathway in Parkinson's disease (PD). In addition, polymorphisms of these three genes have been shown to be independently associated with PD. In a sample of 298 unrelated PD cases and 185 controls, we applied a two-phased approach of recursive partitioning and logistic regression analyses to explore complex interactions. For women only, we observed an epistatic interaction of UCHL1 and alpha-synuclein genotypes with significant effects on PD risk (odds ratio = 2.42; P = 0.003). Our findings are consistent with the hypothesis that PD is a multigenic disorder of the UPS.     

Australian data and meta-analysis lend support for alpha-synuclein (NACP-Rep1) as a risk factor for Parkinson's disease

It remains unclear whether genetic variants in SNCA (the alpha-synuclein gene) alter risk for sporadic Parkinson's disease (PD). The polymorphic mixed sequence repeat (NACP-Rep1) in the promoter region of SNCA has been previously examined as a potential susceptibility factor for PD with conflicting results. We report genotype and allele distributions at this locus from 369 PD cases and 370 control subjects of European Australian ancestry, with alleles designated as -1, 0, +1, +2, and +3 as previously described. Allele frequencies designated (0) were less common in Australian cases compared to controls (OR=0.80, 95% CI 0.62-1.03). Combined analysis including all previously published ancestral European Rep1 data yielded a highly significant association between the 0 allele and a reduced risk for PD (OR=0.79, 95% CI 0.70-0.89, p=0.0001). Further study must now proceed to examine in detail this interesting and biologically plausible genetic association.     

Hirudin and Hirulog: Advances in antithrombotic therapy

Summary Over the past two decades, advances in the prevention and treatment of coronary artery disease, e.g., coronary angioplasty and coronary thrombolysis, have been coupled with the need for improved antithrombotic therapy to prevent acute, life-threatening thrombotic complications. Concurrently, studies on the pathophysiologic mechanisms for the arterial thrombotic process have demonstrated a central, mediating role for thrombin. Brought forward from its identification in the late 19th century, the leech protein hirudin emerged as a model for recombinant DNA engineering and protein-mimetic drug design. Recombinant hirudin (r-hirudin) and Hirulog are the resulting drug candidates which, as direct thrombin inhibitors, offer several potential advances in the management of acute thrombotic disorders. Clinical trials of these drug candidates have already provided evidence for clinical activity and tolerability in thromboembolic disease. Definitive evidence for efficacy is currently sought in large, controlled studies in the settings of coronary angioplasty, coronary thrombolysis and unstable angina.Hirulog antithrombin is a product of Biogen, Inc., Cambridge, MA, U.S.A.     

Early-life educational attainment,APOE ε4 alleles,and incident dementia risk in late life

GeroScience - We examined the interactions between educational attainment and genetic susceptibility on dementia risk among adults over 60&nbsp;years old. A total of 174,161 participants were...     

Combination of inhibition of thrombin and blockade of thromboxane A2 synthetase and receptors enhances thrombolysis and delays reocclusion in canine coronary arteries.

BACKGROUND. The efficacy of thrombolytic therapy in treating patients with acute myocardial infarction is limited by failure to achieve reperfusion in some patients, by the prolonged time required to achieve reperfusion, and by reocclusion of some coronary arteries. We designed this study to examine the effect of combined inhibition of thrombin and thromboxane synthesis and blockade of thromboxane A2 receptors in addition to tissue-type plasminogen activator (t-PA) on thrombolysis and reocclusion in an experimental canine model with coronary thrombosis. METHODS AND RESULTS. Blood flow velocity in the left anterior descending coronary artery (LAD) of 32 anesthetized mongrel dogs was monitored by a pulsed Doppler flow probe. Coronary thrombosis was induced by applying electrical stimulation to the LAD at the site where an external constrictor was used to narrow the artery. Three hours after the formation of occlusive thrombus, animals were randomly assigned to receive one of the following: 1) t-PA (80 micrograms/kg + 8 micrograms.kg-1.min-1 i.v.) and saline; 2) t-PA and hirulog, a hirudin-based synthetic peptide and specific thrombin inhibitor (2 mg/kg + 2 mg.kg-1.hr-1 i.v.); 3) t-PA and ridogrel, a combined thromboxane A2 synthetase inhibitor and receptor antagonist (5 mg/kg + 2.5 mg.kg-1.hr-1 i.v.); or 4) t-PA, hirulog, and ridogrel. Reperfusion developed in 14% (one of seven) of dogs treated with t-PA alone at an average of 86 +/- 4 minutes after treatment, in 78% (seven of nine) of dogs treated with t-PA plus hirulog at 53 +/- 11 minutes, in 13% (one of eight) of dogs treated with t-PA plus ridogrel at 85 +/- 5 minutes, and in 88% (seven of eight) of dogs treated with t-PA, hirulog, and ridogrel at 37 +/- 10 minutes (comparison of the frequency of and the time to reperfusion, both p < 0.01). Among the dogs with reestablished coronary blood flow, reocclusion developed in the one treated with t-PA alone at 36 minutes after reperfusion, in seven of the seven treated with t-PA plus hirulog at 66 +/- 15 minutes, and in two of the seven treated with t-PA, hirulog, and ridogrel at 151 +/- 21 minutes (comparison of the frequency of and time to reocclusion, both p < 0.05). Reocclusion was not detected in the one dog treated with t-PA and ridogrel or in the other five dogs treated with t-PA, hirulog, and ridogrel within 180 minutes after reperfusion. Hirulog prolonged and maintained activated clotting times at a level twice that of baseline values. Hirulog inhibited ex vivo platelet aggregation induced by thrombin, and ridogrel inhibited platelet aggregation induced by U46619, a thromboxane mimetic. CONCLUSIONS. Inhibition of thrombin in addition to treatment with t-PA enhances thrombolysis. A combination of inhibition of thrombin and thromboxane synthetase and blockade of thromboxane A2 receptor enhances thrombolysis and delays or may prevent reocclusion of the recanalized coronary arteries.     

Smoking, alcohol, and coffee consumption preceding Parkinson's disease: a case-control study

OBJECTIVE: To study the association of PD with preceding smoking, alcohol, and coffee consumption using a case-control design. METHODS: The authors used the medical records linkage system of the Rochester Epidemiology Project to identify 196 subjects who developed PD in Olmsted County, MN, during the years 1976 to 1995. Each incident case was matched by age (+/-1 year) and sex to a general population control subject. The authors reviewed the complete medical records of cases and control subjects to abstract exposure information. RESULTS: For coffee consumption, the authors found an OR of 0.35 (95% CI = 0.16 to 0.78, p = 0.01), a dose-effect trend (p = 0.003), and a later age at PD onset in cases who drank coffee compared with those who never did (median 72 versus 64 years; p = 0.0002). The inverse association with coffee remained significant after adjustment for education, smoking, and alcohol drinking and was restricted to PD cases with onset at age <72 years and to men. The OR for cigarette smoking was 0.69 (95% CI = 0.45 to 1.08, p = 0.1). The authors found no association between PD and alcohol consumption. Extreme or unusual behaviors such as tobacco chewing or snuff use and a diagnosis of alcoholism were significantly more common in control subjects than cases. CONCLUSIONS: These findings suggest an inverse association between coffee drinking and PD; however, this association does not imply that coffee has a direct protective effect against PD. Alternative explanations for the association should be considered.