Asbestos fibers, members of complex crystal-chemical systems, possess some range in characteristic properties. Identification of fibers requires morphological, structural, and chemical data. Most current work centers on identification of single, sublight-microscopic fibers present as contaminants in a range of media. Constraints encountered in the analysis of such materials are: sample preparat...

The assembly of the gnathostome bodyplan constitutes a formative episode in vertebrate evolutionary history, an interval in which the mineralized skeleton and its canonical suite of cell and tissue types originated. Fossil jawless fishes, assigned to the gnathostome stem-lineage, provide an unparalleled insight into the origin and evolution of the skeleton, hindered only by uncertainty over the...

Chemical modifications to DNA and histone proteins form a complex regulatory network that modulates chromatin structure and genome function. The epigenome refers to the complete description of these potentially heritable changes across the genome. The composition of the epigenome within a given cell is a function of genetic determinants, lineage, and environment. With the sequencing of the huma...

Histocompatibility testing was performed in 48 multiple sclerosis patients and two carefully matched control groups in Orkney Islands, an area of high multiple sclerosis prevalence. The frequency of HLA-A3, HLA-B7, and DW2 was comparable in patients and controls. However, HLA-B7 was significantly more common in female patients compared with male patients. A B-cell alloantigen (B-cell 4) was als...

Direct microcytotoxicity testing and absorption analyses were employed to determine whether H-2K, H-2D, and Ia antigens are present on murine islet of Langerhans cells. Products of the H-2K and H-2D loci were found on beta-cells from three different mouse strains, but I-region (Ia) antigens were not detected. The absence of Ia gene products from islet cells may be of importance in explaining th...

Non-identical transplants (allogeneic) have been a modern medicine milestone; however, the major pitfall for completed succeed is recognition of foreign organ by immune system. The myriad variations in sequence molecules histocompatibility complex (MHC) or human leukocyte antigen (HLA) between individuals are cause allograft rejection. Thus, B T lymphocytes receptor occurs hypervariable regions...

Preimplantation tissue typing has been proposed as a method for creating a tissue matched child that can serve as a haematopoietic stem cell donor to save its sick sibling in need of a stem cell transplant. Despite recent promising results, many people have expressed their disapproval of this method. This paper addresses the main concerns of these critics: the risk of preimplantation genetic di...

Proteasomes are 650-kDa, multisubunit endopeptidases that might be involved in the MHC class I Ag processing pathway. We demonstrate the existence of multiple structurally distinct subsets of proteasomes. Distinct forms of proteasomes share a hypothetical core to which unique subunits are added. One of these subsets, LMP2+ proteasome, contains the product of the MHC-linked Lmp-2 gene, and can b...

1. The mixed lymphocyte culture test where live lymphocytes of female mice are cultured with supersonicated cell homogenate of isogeneic male mice does not reflect the difference in H-Y histocompatibility antigen alone. 2. When non-H-2 antigens are cumulated in various combinations, the rate of blastformation becomes greater than the combination of C3H ♀ themselves. 3. When non-H-2 antig...