Structure-specific amyloid precipitation in biofluids.

The composition of soluble toxic protein aggregates formed in vivo is currently unknown in neurodegenerative diseases, due to their ultra-low concentration in human biofluids and their high degree of heterogeneity. Here we report a method to capture amyloid-containing aggregates in human biofluids in an unbiased way, a process we name amyloid precipitation. We use a structure-specific chemical dimer, a Y-shaped, bio-inspired small molecule with two capture groups, for amyloid precipitation to increase affinity. Our capture molecule for amyloid precipitation (CAP-1) consists of a derivative of Pittsburgh Compound B (dimer) to target the cross ß-sheets of amyloids and a biotin moiety for surface immobilization. By coupling CAP-1 to magnetic beads, we demonstrate that we can target the amyloid structure of all protein aggregates present in human cerebrospinal fluid, isolate them for analysis and then characterize them using single-molecule fluorescence imaging and mass spectrometry. Amyloid precipitation enables unbiased determination of the molecular composition and structural features of the in vivo aggregates formed in neurodegenerative diseases.

[Hydatidiform mole in Vietnam. The contribution of ultrasonography]. / Môle hydatiforme au Vietnam. Apport de l'échographie.

One-hundred-and-four cases of histopathologically confirmed hydatiform moles were subjected to ultrasound examination at the Hung Vuong Hospital, Ho-Chi-Minh-ville (Vietnam) over a period of 16 months (1988-1989). The diagnosis was confirmed only in some cases on clinical grounds (18%) or by laboratory tests (52%). In contrast, typical ultrasound signs were found in 82% of cases; in the other 18% of cases, other aspects had suggested disorders calling for aspiration (partial mole, clear ovum, pregnancy terminated). Some ultrasound images, highly suggestive of mole, were found in occasional cases of mucoid ovarian cyst, endometrial cancer or cystic necrobiosis of fibroma (HCG tests negative). Despite its limitations in Vietnam ultrasound constitutes the primary method of detecting hydatiform mole, the acquisition of practical experience is facilitated by the high number of cases and the concentration of cases reported.