Lack of association between HLA antigen DR3 and α<inf>1</inf> deficiency in liver transplant recipients

The relationship between α1-antitrypsin deficiency (α-ATD) and the HLA antigen system was studied in 32 liver transplant recipients. Despite previous reports of an association of HLA antigen DR3 with homozygosity for α-AT ZZ, no such association was seen in this population of α-ATD homozygous ZZ patients with advanced hepatic disease. Thus, the reported association of HLA class II antigens and homozygosity for the Z allele for α-AT may be an artifact of either a small study population or geographic inbreeding and a coincidental association of certain HLA antigens with the presence of homozygosity for the Z allele of α-AT. © 1993 Plenum Publishing Corporation

High figure of merit (FOM) of Bragg modes in Au-coated nanodisk arrays for plasmonic sensing

We report that gold-coated nanodisk arrays of nearly micron periodicity have high figure of merit (FOM) and sensitivity necessary for plasmonic refractometric sensing, with the added benefit of suitability for surface-enhanced Raman scattering (SERS), large scale microfabrication using standard photolithographic techniques and a simple instrumental setup. Gold nanodisk arrays were covered with a gold layer to excite the Bragg modes (BM) which are the propagative surface plasmons localized by the diffraction from the disk array. This generated surface-guided modes, localized as standing waves, leading to highly confined fields confirmed by a mapping of the SERS intensity and numerical simulations with 3D finite element method (3D FEM). The optimal gold-coated nanodisk arrays were applied for refractometric sensing in transmission spectroscopy with better performance than nanohole arrays and they were integrated to a 96-well plate reader for detection of IgY proteins in the nM range in PBS. The potential for sensing in biofluids was assessed with IgG detection in 1:1 diluted urine. The structure exhibits a high FOM of up to 46, exceeding the FOM of structures supporting surface plasmon polaritons (SPPs) and comparable to more complex nanostructures, demonstrating that sub-wavelength features are not necessary for high performance plasmonic sensing

Spatial memory in rats with lesions to the region of the mammillary bodies

The objective of this investigation was to determine whether lesions to the region of the mammillary bodies of rats impair performance on various learning and memory tasks. It was demonstrated that such lesions are sufficient to impair performance on tasks that require memory for spatial information. Deficits were found in both working and reference memory paradigms, with more severe impairments in the former. Ability to discriminate spatial location was not affected when delay was minimal, but retention was progressively impaired as delay was increased. A dissociation in the effect of the lesions on performance of analogous spatial and nonspatial tasks was observed. The lesions did not impair the learning of a visual discrimination/reversal, or a conditioned taste aversion. It is concluded that lesions to the region of the mammillary bodies have a selective effect on spatial learning and memory. The relevance of these findings to Korsakoff's psychosis is discussed