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

A glimpse into the differential topology and geometry of optimal transport

This note exposes the differential topology and geometry underlying some of the basic phenomena of optimal transportation. It surveys basic questions concerning Monge maps and Kantorovich measures: existence and regularity of the former, uniqueness of the latter, and estimates for the dimension of its support, as well as the associated linear programming duality. It shows the answers to these questions concern the differential geometry and topology of the chosen transportation cost. It also establishes new connections --- some heuristic and others rigorous --- based on the properties of the cross-difference of this cost, and its Taylor expansion at the diagonal.Comment: 27 page

Poly(m-Phenylenediamine) Nanospheres and Nanorods: Selective Synthesis and Their Application for Multiplex Nucleic Acid Detection

In this paper, we demonstrate for the first time that poly(m-phenylenediamine) (PMPD) nanospheres and nanorods can be selectively synthesized via chemical oxidation polymerization of m-phenylenediamine (MPD) monomers using ammonium persulfate (APS) as an oxidant at room temperature. It suggests that the pH value plays a critical role in controlling the the morphology of the nanostructures and fast polymerization rate favors the anisotropic growth of PMPD under homogeneous nucleation condition. We further demonstrate that such PMPD nanostructures can be used as an effective fluorescent sensing platform for multiplex nucleic acid detection. A detection limit as low as 50 pM and a high selectivity down to single-base mismatch could be achieved. The fluorescence quenching is attributed to photoinduced electron transfer from nitrogen atom in PMPD to excited fluorophore. Most importantly, the successful use of this sensing platform in human blood serum system is also demonstrated

Worldwide epidemiology and modes of transmission of delta hepatitis

Since the discovery of HDV in 1977 by Rizzetto and collegues (10), several studies regarding the pathogenesis, natural history and epidemiology of this infection have been accumulated. It emerges that HDV is an agent with unusual biologic properties which requires HBV replication for its expression. Given the obligatory association between HDV and HBV, transmission of HDV follows the same routes of HBV transmission. This implies that one expects HDV infection to be much more prevalent in countries with high HBsAg carrier rates. This is true in most areas of the world but not in Far East Asia. Endemicity of HDV is maintained in the community through the network of HBsAg carriers. HDV can be transmitted to HBV positive and negative individuals, but survives only after encountering the carrier. Recent outbreaks of severe epidemics of fulminant hepatitis due to HDV among the Yucpa Indians in Northern Venezuela, pointed out very clearly that HDV superinfection is an ominous risk for all populations where HBV is endemic

Infections with the hepatitis B virus associated delta agent in an isolated West-African community

The occurrence of delta agent (delta) infection in the native population of the isolated Gbawein and Wroughbarh Clan region of Grand Bassa County, Liberia was studied. Sera of 97 patients with epilepsy, 73 non-epileptic relatives, and 31 non-epileptic control subjects were tested for hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs) and antibody to delta antigen (anti-delta). Of the 201 individuals tested 76 (37.8%) were HBsAg positive; the overall infection rate (HBsAg and anti-HBs positives) was 68.7%. No correlation with clinical disease could be established. Markers of delta infection were detected in seven index cases. All subjects with anti-delta were HBsAg positive except one, who was anti-HBs positive with a low titre of anti-delta (less than 1:10(2)), which is indicative of a recent delta infection. Mothers of six delta infected index cases were available for testing, one was found HBsAg and anti-delta positive, while the other five were anti-HBs positive and anti-delta negative. No delta infections occurred in children of HBV negative mothers. Presence of delta markers varied significantly (P less than 0.02) among HBsAg carriers of the Kpelle (18%) and the Bassa (2%) language group. A comparable difference in delta markers was observed among HBsAg carriers of the Gbawein (17%) and the Wroughbarh (4%) clan

Epidemiology of hepatitis delta virus (HDV) infection

Markers of hepatitis delta virus (HDV) infection have been detected all over the five continents. Geographical prevalence varied heavily: HDV infection is very rare in Far East Asia, but extremely frequent in Arabian countries, in Romania and in certain Indian populations of South America. In Europe and in the USA the infection is widely spread among high risk groups such as intravenous drug abusers and haemophiliacs