Cerebrospinal fluid tau, phospho-tau181 and beta-amyloid1-42 in idiopathic normal pressure hydrocephalus: a discrimination from Alzheimer's disease.

The aim of the present study was the quantitation of total tau protein (tau(T)), tau phosphorylated at threonine 181 (tau(P-181)) and beta-amyloid(1-42) (Abeta42) in the cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH), Alzheimer's disease (AD) and controls. Double sandwich ELISAs (Innogenetics) were used for the measurements. Total tau was significantly increased in iNPH and highly increased in AD as compared with the control group, whilst Abeta42 was decreased in both diseases. CSF tau(P-181) levels were significantly increased only in AD, but not in iNPH as compared with the controls. A cut-off level for tau(T) at 300 pg/ml, successfully discriminated AD from normal aging with a 95.8% specificity and 91% sensitivity; whilst the tau(P-181)/tau(T) ratio (cut-off value 0.169) was more specific (100%) but less sensitive (92.5%). For the discrimination of iNPH from AD tau(T) achieved low specificity (77.8%) but high sensitivity (92.5%), whilst tau(P-181) (cut-off value 47.4) was both sensitive and specific (88.7% and 86.7% respectively) for the discrimination of these disorders. The present study, despite being clinical, supports the notion that CSF tau(P-181) alone or in combination with tau(T) may be a useful marker in the discrimination of iNPH from AD.

Cortical atrophy detected by computed tomography in gasoline station attendants.

BACKGROUND: To evaluate the contribution of leaded gasoline in the presence of abnormal calcifications or cortical atrophy seen in computed tomographies (CT) of the head of occupationally exposed professionals working in the centre of Athens. METHODS: One hundred and twenty-two head CTs from gas station employees and traffic-exposed professionals (taxi and bus drivers) were analyzed for evidence of cortical atrophy or abnormal calcifications. Blood lead level (BLL) of these lead occupationally exposed groups was compared with 37 non-exposed subjects. RESULTS: All three occupationally exposed-to-lead groups had similar blood lead levels compared to the non-exposed group and within the currently accepted norms for lead. No abnormal calcifications were found. Cortical atrophy was more frequently seen in the gas station employees group using univariate and multivariate analysis. In the logistic regression model gas station employment had a stronger impact in developing cortical atrophy [odds ratio of 6.43 (1.46-28.3, 95% CI)] than BLL [odds ratio of 1.4 (1.01-2.05, 95% CI)]. CONCLUSIONS: These results show that employment in gasoline stations may be associated with detectable cortical atrophy in imaging studies and suggest the contribution of a leaded gasoline to its development.

Blood lead levels of traffic- and gasoline-exposed professionals in the city of Athens.

During the past 10 y, blood lead levels in the population of Athens, Greece, have decreased steadily. This decrease has paralleled the reduction of tetraethyl lead in gasoline and the introduction of unleaded fuel. Blood lead levels and other parameters were studied in 42 gas-station employees, 47 taxi drivers, 47 bus drivers, and 36 controls, all of whom worked in Athens. The blood lead levels did not differ significantly among the four groups (5.64+/-1.7 microg/dl, 5.96+/-1.7 microg/dl, 5.88+/-1.3 microg/dl, and 5.76+/-1.7 microg/dl, respectively). Glutamic-oxaloacetic transaminase (i.e., aspartate aminotransferase) and glutamic-pyruvic transaminase (i.e., alanine aminotransferase) were elevated in gas-station employees, and the former was elevated in taxi drivers. Gas-station employees who smoked had higher blood lead levels than their nonsmoking counterparts. The absence of any difference in the blood lead levels of individuals for whom physical examinations were either normal or abnormal suggests that either lead was not the cause of increased blood lead levels or that its contribution may have been important in the past.