A new HLA-A allele, HLA-A*6824, identified in three unrelated individuals

A novel allele, human leukocyte antigen (HLA)-A*6824, has been identified in three unrelated individuals of northwestern European origin in a period of less than 4 months, implying that this allele may be quite common in this population. HLA-A*6824 differs from A*680102 by a single nucleotide change at position 275 in exon 2, which results in a conservative amino acid substitution from lysine to arginine in the peptide-binding groove at codon 68.     

Identification of a new HLA-B*15 allele,HLA-B*1569

We have identified a new HLA-B*15 allele (B*1569) by polymerase chain reaction (PCR) using sequence-specific primers (SSP) and sequence-based typing (SBT). This novel allele was found in a 67-year-old white Caucasian male and differs from HLA-B*1503 at 3 positions. The nucleotide substitutions at positions 544, 559 and 560 result in amino acid changes at codon 158 from GCC (alanine) to ACC (threonine), and at codon 163 from CTG (leucine) to ACG (threonine).     

Polymorphic Alu Insertions and their Associations with MHC Class I Alleles and Haplotypes in the Northeastern Thais

Polymorphic Alu insertions (POALINs) are known to contribute to the strong polymorphic nature of the Major Histocompatibility Complex (MHC). Previous population studies on MHC POALINs were limited to only Australian Caucasians and Japanese. Here, we report on the individual insertion frequency of the five POALINs within the MHC class I region, their HLA‐A and ‐B associations, and the three and four locus alpha block POALIN haplotype frequencies in the Northeastern (NE) Thai population. Of the five POALINs, the lowest frequency was 0.018 for AluyHF and the highest frequency was 0.292 for AluyHJ and AluyHG. The strongest positive associations between the POALINs and HLA class I alleles was between AluyMICB and HLA‐B*57, AluyHJ and HLA‐A*24 and HLA‐A*01, and AluyHG and HLA‐A*02, supporting previous findings in Caucasians and Japanese. Single POALIN haplotypes were found more frequently than multiple POALIN haplotypes. However, of the seven different POALIN haplotypes within the MHC alpha block, there were only two significant differences between the NE Thais, Caucasians and Japanese. This study confirms that the MHC POALINs are in linkage disequilibrium with HLA‐A and –B alleles and that there are significant frequency differences for some of the POALINs when compared between NE Thai, Caucasians and Japanese.     

Correlation of leukocyte interleukin-1 production with the stimulation of prostaglandin and tissue factor synthesis by human umbilical vein endothelial cells

Human leukocyte suspensions (neutrophils 80–85%, monocyte 15–20%) were incubated alone or with cultured human umbilical vein endothelial cells. Leukocytes were either directly added to the endothelial cell cultures or separated from them by a 0.4 micron insert filter. Supernatants or cell lysates were obtained at 0.5, 1, 2, and 4 hours of incubation. Supernatants were assayed for the prostacyclin (PGI₂) metabolite 6-keto prostaglandin F₁ and prostaglandin E₂ (PGE₂) by radioimmunoassay and for interleukin-1 (IL-1) by the thymocyte co-mitogen assay. Cell lysates were analyzed for cell-associated procoagulant activity (PCA). Co-incubation of endothelial cells with leukocytes stimulated the synthesis of PGI₂, PGE₂, and PCA. These biochemical changes correlated partially with the release of IL-1 beta. The results suggest that IL-1 released in monocyte/neutrophil co-cultures can produce prothrombotic (increased PCA expression) and inflammatory changes (increased synthesis of vasodilatory and permeability enhancing PGI₂ and PGE₂) in endothelial cells. Neutrophils may represent a source of the released IL-1 and/or may act to stimulate monocyte release of this cytokine and thus play an important role in vascular pathology by a mechanism unrelated to their more direct cytotoxic activity.     

Two-dimensional gel electrophoresis and immunoblotting of Campylobacter pylori proteins.

Whole-cell, outer-membrane protein, flagellum-associated antigens and partially purified urease of Campylobacter pylori were analyzed by two-dimensional gel electrophoresis. C. pylori strains were readily distinguished from strains of Campylobacter jejuni, C. coli, and C. fetus by absence of major outer membrane proteins with Mrs of 41,000 to 45,000. C. pylori strains also lacked the acidic surface-array proteins at Mr 100,000 to 149,000 identified previously in serum-resistant strains of C. fetus. Surface labeling of intact C. pylori cells with 125I revealed two common major proteins, which we have designated protein 2 (pI 5.6 to 5.8, Mr 66,000) and protein 3 (pI 5.2 to 5.5, Mr 63,000). Proteins 2 and 3 were also the major components (subunits) observed in partially purified urease. Partially purified preparations of flagella consistently contained proteins 2 and 3. Thus, urease appears to be associated with both outer membranes and flagella of C. pylori. C. pylori strains also possessed an antigen at Mr 59,000 which was cross-reactive with antiserum against flagella of C. jejuni. However, the antigen did not appear to be associated with flagella per se in C. pylori. Protein 2 was unique to C. pylori among the Campylobacter species studied. It was not recognized by antibody against whole cells of C. jejuni or C. fetus or flagella of C. jejuni. Protein 3 was cross-reactive with antiserum against whole cells of C. jejuni and C. fetus, as were several other major protein antigens. Because protein 2 is a major outer membrane protein that is apparently unique to C. pylori, development of monospecific antibodies against this antigen may be useful for the identification of C. pylori in tissues, and purified antigen may be useful for serologic tests for specific diagnosis of C. pylori infections.     

Functional evaluation of collagen fiber scaffolds for ACL reconstruction: cyclic loading in proteolytic enzyme solutions

The mechanical properties of anterior cruciate ligament (ACL) reconstruction scaffolds were evaluated after exposure to functional challenges in vitro: cyclic loading combined with various proteolytic enzymes. Scaffolds were prepared from collagen fibers that were uncrosslinked (UNXL), crosslinked with ultraviolet irradiation (UV), or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC; 10 or 25 mM). Structural properties of scaffolds were determined following 1-h exposure to saline, trypsin, or bacterial collagenase, with and without simultaneous cyclic tensile loading (0 to 50 g; 0.5 Hz) in vitro. The breaking load and stiffness of UNXL and UV crosslinked scaffolds were significantly reduced by exposure to either trypsin or collagenase. Cyclic loads interacted synergistically with enzymes, rendering UNXL scaffolds untestable and further decreasing the breaking load of UV crosslinked scaffolds by approximately 35%. In contrast, the breaking load and stiffness of EDC crosslinked scaffolds, which were greater than those of UNXL or UV crosslinked scaffolds, were virtually unaffected by the same load and enzyme treatments. These results suggest that EDC is more effective than UV for crosslinking and stabilizing load-bearing collagen fiber ACL reconstruction scaffolds. Application of cyclic loads and enzymes may lead to development of physiologically relevant in vitro test methods for load-bearing scaffolds.     

Serotypic and genotypic characterization of human serotype 10 rotaviruses from asymptomatic neonates.

Human rotaviruses were isolated from asymptomatic neonates at various hospitals and clinics in the city of Bangalore, India, and were found to be subgroup I specific and possess long RNA patterns (M. Sukumaran, K. Gowda, P. P. Maiya, T. P. Srinivas, M. S. Kumar, S. Aijaz, R. R. Reddy, L. Padilla, H. B. Greenberg, and C. D. Rao, Arch. Virol. 126:239-251, 1992). Three of these strains were adapted to tissue culture and found by serotype analysis and neutralization assays to be of serotype 10, a serotype commonly found in cattle but infrequently found in humans and not previously identified in neonates. By RNA-RNA hybridization, a high level of relatedness to a serotype 10 bovine rotavirus strain and a low-to-medium level of relatedness to a human rotavirus strain were observed. Since this human isolate shares a genogroup with bovine rotavirus, it is likely that it originated by interspecies transmission. A human rotavirus strain isolated from asymptomatic neonates and similar to bovine rotavirus might represent a good vaccine candidate.     

32P-Postlabelling analysis of aromatic DNA adducts in human oral mucosal cells

Exfoliated mucosal cells were collected from the oral cavityof three groups at high risk for oral cancer: Indian betel nutchewers, Filipino inverted smokers (burning end of cigar inmouth) and Indian Khaini tobacco chewers. DNA was extractedfrom these samples, as well as from samples of exfoliated cellsof Canadian non-smoking controls. DNA was analyzed for the presenceof aromatic DNA adducts using ³²P-postlabel-ling analysis. Fivechromatographically distinct adducts were found in samples fromboth the high risk groups and the nonsmoking controls. Individualadducts were detectable in 30–95% of samples, dependingon the adduct and population group. Estimated levels of specificadducts ranged from non-detectable (prevalence relative to normalnucleotides < 1 x 10^-9) to occasionally > 1x 10^-7. Noadducts were found in high risk groups which did not also appearin control subjects.     

Development of a Programme Theory for Early Intervention Vocational Rehabilitation: A Realist Literature Review

Journal of Occupational Rehabilitation - Purpose Little is currently known about how early intervention vocational rehabilitation (EIVR) works for people with newly acquired neurological conditions...