Search PubMed⌕ Search

Biomedical subjects

E Simpson

Publications and source records attributed to E Simpson.

At least 217 records · Page 12Linked to original sources
PubMed1978

A survey of weighing performance in clinical biochemistry laboratories.

Results of a survey of accuracy and precision of weighing in a sample of clinical biochemistry laboratories in the U.K. are reported. 101 laboratories each carried out eight weighings. 94% of weighings were subject to errors of not more than 1.7 mg at the 2 g level and not more than 1.0 mg at the 100 mg level. However, 9% of the laboratories produced results which were consistently subject to larger errors.

Chemistry, Clinical↗
PubMed1978

Cytotoxic T-cell responses to H-Y: mapping of the Ir genes.

The secondary cytotoxic responses to the male specific antigen (H-Y) in in mice show H-2 restrictions so that cytotoxic female cells must share K and/or D end antigen with the male target cells. The production of cytotoxic cells is under the control of Ir genes, thus offering the possibility of studying the function of Ir genes in H-2-restricted cytotoxic responses. There are two kinds of Ir genes regulating this response; the dominant gene in the H-2b haplotype and complementary genes in other haplotypes. Now we have been able to map the dominant gene and some of the complementary genes: the dominant genes is in IAb, and in H-2k/H-2d complementation, the Ir genes are in ICk and ICd, and in H-2k/H2s and H-2k/H-2q complementations, at least the H-2k gene is in IC.

Animals↗
PubMed1978

Cytotoxic T-cell responses to H-Y: correlation with the rejection of syngeneic male skin grafts.

The ability of female mice to rapidly reject syngenic male skin grafts is largely determined by dominant genes in the IB region of the H-2b halotype, whereas the ability to produce anti-H-Y cytotoxic cells is determined by a dominant gene in the IA region the H-2b halotype, or by complementary genes in the IC region of some other haplotypes. Thus, it seems that H-2-retricted anti-H-Y cytotoxic T cells are not responsible for the rejection of syngeneic male skin grafts.

Animals↗
PubMed1978

Anti-H-Y responses of H-2b mutant mice.

Two strains of H-2b mutant mice, H-2ba and H-2bf, in which the mutational event took place at H-2K, make anti-H-Y cytotoxic T cell responses which are H-2-restricted, Db-associated and indistinguishable in target cell specificity from those of H-2b mice. Thus, alteration of the H-2K molecule affects neither the Ir gene controlling the response, nor the associative antigen. On the other hand, one H-2Db mutant strain, H-2bo, although it makes a good anti-H-Y cytotoxic response, shows target cell specificity restricted to its own Dbo antigen(s), and neither H-2b, H-2ba or H-2bf anti-H-Y cytotoxic cells kill H-2bo male target cells. Thus, the alteration of the H-2Db molecule does not affect the Ir gene of H-2b mice, but it does alter the H-2Db-associative antigen.

Animals↗
PubMed1978

H-2 complementation in anti-H-Y cytotoxic T-cell responses can occur in chimeric mice.

Cytotoxic T-cell responses against the H-Y antigen in mice are under the control of major histocompatibility complex genes. Not only must cytotoxic T cells recognize both H-Y antigens and "self" H-2K/D molecules to lyse male target cells, but also "appropriate association" between H-Y antigens and H-2K/D antigens is required to induce such cytotoxic responses. Furthermore, it is suggested that appropriate association with H-2-I antigens may also be required to generate H-Y specific helper cells for the cytotoxic response. BALB/c(KdIdDd) mice are nonresponders against syngeneic H-Y antigens, because they lack appropriate associative H-2K/D antigens. This results in the failure of generation of anti H-Y cytotoxic cells, although helper cells may be induced. F1 hybrid mice (BALB/c X C3H/He)F1 or H-2 recombinant mice C3H-OH(KdIdDk) are responders, because H-2Dk (and H-2Kk in the F1) molecules offer appropriate association to H-Y antigens. We here report that allophenic chimeras (H-2d reversible H-2k) and irradiation bone marrow chimeras [H-2d + H-2k leads to F1(H-2d X H-2k)] generate anti-H-Y cytotoxic responses but that cells of the BALB/c(H-2d) genotype comprise most if not all of the cytotoxic cells. A working model is proposed to account for major histocompatibility complex control over anti-H-Y cytotoxic T-cell responses.

Bone Marrow↗
PubMed1978

An evaluation of the Jeol Clinalyzer.

The Jeol Clinalyzer was evaluated over a period of 15 weeks. The operating principles are briefly described. The functions of the mechanical components were tested and assessments made of the instrument's safety and reliability. The mechanical and electrical reliability of the instrument was excellent and the pumps and spectrophotometer gave good accuracy and precision. Between-batch precision of the analytical methods was good for urea, protein and bilirubin and acceptable for alkaline phosphatase and aspartate transaminase. There was a poor relative accuracy for alkaline phosphatase and aspartate transaminase and some proportional inaccuracy for urea and bilirubin.

Alkaline Phosphatase↗
PubMed1977

Selective response to H-Y antigen by F1 female mice sensitized to F1 male cells.

T-cell mediated cytotoxic responses to H-Y antigen require co-recognition of H-Y and H-2 gene products. F1 mael stimulating cells and target cells express H-Y antigen in association with both parental H-2 haplotypes. However, F1 females primed in vivo and challenged in vitro with F1 male cells lyse male target cells of F1 and only one parental H-2 haplotype. Thus, (CBA X B10)F1 females sensitized to (CBA X B10)F1 male cells lyse (CBA X B10)F1 and CBA but not B10 male target cells, and (BALB/c X B10)F1 females sensitized to (BALB/c X B10)F1 male cells will lyse (BALB/c X B10)F1 and B10 but not BALB/c male target cells. It is suggested that this may represent an effect of immune response or suppressor genes mapping in the major histocompatibility gene complex which regulate responsiveness to H-Y antigen.

Animals↗
PubMed1977

The quality control of alkaline phosphatase determinations with placental phosphatase.

Human placenta has been recommended as the source of the alkaline phosphatase used for the preparation of control or reference materials. The effect of certain inhibitors, which may be present in the reagents, on control materials containing the placental isoenzyme, is shown to differ significantly from their effect on the isoenzymes in patient's sera. This finding indicates that if control materials are used which contain only human placental alkaline phosphatase, changes in accuracy resulting from differences in reagent quality may be missed, or alternatively a change in accuracy may be indicated by the quality control results which does not apply to the patient's sera.

Alkaline Phosphatase↗
PubMed1977

A method for visual assessment of the performance of components in a continuous flow system.

When two reagents are mixed in a continuous flow system it is difficult to detect variations in their proportions in the individual liquid segments because such variations produce only small changes in the final colour intensity. A method is described whereby these differences in reagent proportion produce a different pH in each segment and, by the addition of an appropriate pH indicator solution, a different colour for each segment. This method may be used to demonstrate the eveness of reagent injection, reagent mixing and segment/segment interaction associated with continuous flow systems.

Autoanalysis↗