SUMMARY Tomogrephic images of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) using the U O continuous inhalation technique, and positron emission tomography, were obtained from a patient with cerebral ischemia distal to an occluded left internal carotid artery. There was a focal mismatch between CBF and oxygen metabolism in the brain supplied by tbe middle cerebral artery where CBF was decreased and OEF increased ("misery-perfusion syndrome" as opposed to "luxury-perfusioa syndrome"). These abnormalities were most marked in tbe parieto-ocdpital watershed area. After left superficial temporal to middle cerebral artery anastomosis, the clinical attacks ceased and a repeat study did not demonstrate tbe prerious CBF and OEF abnormalities. This suggests that this pattern of abnormalities indicates potential liable tissue. The concept of "mlsery-perfuslon" may be of some importance In tbe patbophysiological mechanisms of hemodynamic cerebral ischemia and serve as a rational basis for rerascularization procedures.
We have developed a brief screening test aimed at identifying cognitive disorders in Parkinson's disease. The Mini-Mental Parkinson derives from the Mini-Mental State Examination of Folstein. It includes seven ordered subsections, with a total score of 32. A pilot study was conducted in 50 community-dwelling parkinsonian patients, in order to establish its metrological qualities. Comparisons were made with a neuropsychological battery including several tests widely used in the assessment of specific cognitive disorders in Parkinson's disease. The correlations between the Mini-Mental Parkinson and each component of this battery were substantial, especially for the performance subtests of the WAIS-R (r = 0.62 to 0.72), the Stroop test (r = 0.65) the 15-objects test (r = 0.64), the word fluency (r = 0.63) and the Odd Man Out test (r = 0.61). The validity of each subtest of the Mini-Mental Parkinson was adequate except for one, based on a word choice, which requires a modification in French before definitive use. The test-retest reliability was high (r = 0.84). There was a significant difference in the mean scores in cases with confusional event (22.4), even without current signs of dementia, compared with patients with no such history (27.2). In conclusion, this brief test is suitable for assessment of parkinsonian patients.
Background Titanium dioxide (TiO2) is broadly used in common consumer goods, including as a food additive (E171 in Europe) for colouring and opacifying properties. The E171 additive contains TiO2 nanoparticles (NPs), part of them being absorbed in the intestine and accumulated in several systemic organs. Exposure to TiO2-NPs in rodents during pregnancy resulted in alteration of placental functions and a materno-foetal transfer of NPs, both with toxic effects on the foetus. However, no human data are available for pregnant women exposed to food-grade TiO2-NPs and their potential transfer to the foetus. In this study, human placentae collected at term from normal pregnancies and meconium (the first stool of newborns) from unpaired mothers/children were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and scanning transmission electron microscopy (STEM) coupled to energy-dispersive X-ray (EDX) spectroscopy for their titanium (Ti) contents and for analysis of TiO2 particle deposition, respectively. Using an ex vivo placenta perfusion model, we also assessed the transplacental passage of food-grade TiO2 particles. Results By ICP-MS analysis, we evidenced the presence of Ti in all placentae (basal level ranging from 0.01 to 0.48 mg/kg of tissue) and in 50% of the meconium samples (0.02–1.50 mg/kg), suggesting a materno-foetal passage of Ti. STEM-EDX observation of the placental tissues confirmed the presence of TiO2-NPs in addition to iron (Fe), tin (Sn), aluminium (Al) and silicon (Si) as mixed or isolated particle deposits. TiO2 particles, as well as Si, Al, Fe and zinc (Zn) particles were also recovered in the meconium. In placenta perfusion experiments, confocal imaging and SEM-EDX analysis of foetal exudate confirmed a low transfer of food-grade TiO2 particles to the foetal side, which was barely quantifiable by ICP-MS. Diameter measurements showed that 70 to 100% of the TiO2 particles recovered in the foetal exudate were nanosized. Conclusions Altogether, these results show a materno-foetal transfer of TiO2 particles during pregnancy, with food-grade TiO2 as a potential source for foetal exposure to NPs. These data emphasize the need for risk assessment of chronic exposure to TiO2-NPs during pregnancy.
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