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N Henderson

Publications and source records attributed to N Henderson.

At least 55 records · Page 3Linked to original sources
PubMed1987

Requirements for transcriptional activation in vitro of the nitrogen-regulated glnA and nifLA promoters from Klebsiella pneumoniae: dependence on activator concentration.

Three proteins involved in nitrogen regulation in Klebsiella pneumoniae, NTRA, NTRB and NTRC, have been purified. In a defined in vitro system all three NTR proteins are required for initiation of transcription at the ntr activatable glnA and nifLA promoters. However, in crude S-30 extracts, transcription from the glnA promoter, but not the nifLA promoter, can be activated in the absence of NTRB. A higher concentration of NTRC is required for activation of nifLA transcription than for glnA transcription. Sequences located between -227 and -158 with respect to the nifL transcription start site are required for efficient activation of the nifLA promoter in vitro.

Base Sequence↗
PubMed1986

The ability of the serum thyrotrophin receptor antibody (TRAb) index and HLA status to predict long-term remission of thyrotoxicosis following medical therapy for Graves' disease.

In agreement with previous authors we found patients with Graves' disease to have an increased incidence of the DR 3 antigen. We could find no association, however, between the presence of the antigen and relapse after carbimazole treatment. A concordant HLA status and thyrotrophin receptor antibody (TRAb) index, obtained at either 6 or 12 months after the start of treatment could only predict cases of relapse and remission in a minority of patients making this of very limited clinical use. The TRAb index obtained at 12 months after the start of medical therapy could accurately predict cases of relapse and remission for the next 3 years in 24/30 patients studied.

Adult↗
PubMed1984

Acetylation of rat testis histones H2B and TH2B.

The in vivo acetylation of rat testis histones H3 and H4 has been demonstrated in previous studies. In this study, analysis of purified histone fractions revealed the in vivo acetylation of histone H2B, the testis histone variant designated TH2B, and two or more of the histone H2A variants. These findings are quite significant, because it is possible that all of the core histones are acetylated in elongating spermatids at the time of removal of the entire histone complement for replacement by basic spermatidal transition proteins (S.R. Grimes and N. Henderson, 1983, Arch. Biochem. Biophys. 221, 108-116).

Acetylation↗
PubMed1984

Hyperacetylation of histone H4 in rat testis spermatids.

Acetate was incorporated efficiently into rat testis histones after an intratesticular injection of [3H]acetate. The pattern of in vivo acetylation of the testis histones was quite similar to the pattern of in vitro acetylation seen in a previous study with histones H3 and H4 acetylated to the greatest extent [13]. Acetylation of one or more of the major testis H2A variants was confirmed by analysis of these histones on high resolution polyacrylamide gels (PAGE) containing Triton X-100. Of the four variants, H2A.1 appeared to be labeled to the greatest extent. When testis cells were separated into highly enriched populations of specific cell types by centrifugal elutriation after an intratesticular injection of labeled acetate, histone H4 from all fractions of cells was acetylated, but histone H4 from the fraction of cells most enriched in elongating spermatids was hyperacetylated. Thus, the in vivo hyperacetylation of histone H4 which occurs in elongating spermatids is a physiological event which occurs during the relatively short time period when the entire complement of histones is replaced by more basic, protamine-like proteins, and therefore must be one of the key steps in this dramatic protein transition.

Acetates↗
PubMed1984

Defective splenic reticuloendothelial function in idiopathic membranous nephropathy.

We studied splenic macrophage reticuloendothelial function in 18 patients with idiopathic membranous nephropathy and eight patients with mesangio-capillary glomerulonephritis by measuring the clearance from the circulation of technetium labelled, autologous, antibody coated erythrocytes (IgG cells) or heat damaged erythrocytes (HDE). Nine of 15 rhesus-D positive patients with membranous nephropathy had delayed clearance of the IgG cells and the defect did not correlate with disease activity. Circulating immune complexes were not detected in any of the patients with membranous nephropathy. The defect in clearance of the IgG cells in the membranous patients was associated with the presence of HLA-B8 and DR3. In the mesangio-capillary glomerulonephritis patients, the clearance rates of the IgG cells were fast-normal in six and enhanced in two, and correlated with the clearance of HDE. The clearance rates of the cells in this group correlated with the degree of hypocomplementaemia but not with the disease activity nor HLA haplotype.

Adult↗
PubMed1976

Occurrence of minute ring-shaped nucleoprotein particles in culture media conditioned by mammalian cells.

Conditioned media of 21 mammalian cell lines have been examined by electron microscopic and biochemical techniques for the presence of a minute ring-shaped nucleoprotein particle (RSP). Electron microscopy showed the presence of RSP in 20 of the 21 cell lines tested. Comparative analyses of sex cell cultures for radioactive RSP, following 3H-thymidine incorporation, suggested that quantitative differences exist in the amount of RSP detectable in conditioned media of normal and pathologic cells. The cell lines tested included cells of different morphologies, origin and function

Cell Line↗
PubMed1975

The association between HL-A antigens ankylosing spondylitis and sacro-iliitis.

The second series antigen W27 has been found to have an increased frequency in ankylosing spondylitis (82 per cent of 17 patients) and juvenile rheumatoid arthritis (Still's disease) (29 per cent of 24 patients). Three family studies are presented, including one in which the antigen W27 occurs both in the absence and the presence of ankylosing spondylitis. It is suggested that this family illustrates that the relationship between W27 and sacro-iliitis is affected by non-HL-A genes. The development of clinical disease depends upon the coincidence of several factors in one individual, some of which are genetically controlled by two or more loci which are not necessarily linked.

Adolescent↗
PubMed1975

Burkitt's lymphoma and HL-A antigens.

Studies were carried out on the distribution of HL-A antigens in 33 patients with Burkitt's lymphoma from several tribal groups in Kenya. The frequency of distribution of the HL-A antigens was not significantly different in these patients from that in a selected control population. Difficulty was experienced in the precise identification of some HL-A antigens in Africans using a Caucasoid serum panel, in particular those associated with HL-A7 and to a lesser extent, the "W19" complex.

Adolescent↗
PubMedDate not supplied

Homozygous MHC genotypes and longevity.

To investigate the relevance of the major histocompatibility complex (MHC) in longevity, we carried out a molecular analysis of the MHC in 432 unrelated healthy individuals. The comparison of individuals < or = 25 years and > 25 years showed that the 5.8-kb DQA1 allele, which corresponds to HLA-DR53, was negatively associated with longevity (p = 0.0035) resulting mainly from decreased homozygosity with age for that allele (p = 0.008), and restricted to males (p = 0.008). The difference was more striking for the 5.8 kb DQA1: 9.0 kb HSP70 haplotype again only in males (26.3 vs. 6.2%; p = 0.017, OR = 5.4, 95% CI = 1.5 - 19.5). The oldest male subject homozygous for this DQA1: HSP70 haplotype was 54 years (p = 0.005). Comparing leukemic patients and healthy individuals with the same ethnic and geographical origin, homozygosity for these genotypes was more frequent in the young leukemic group. The results suggested the existence of recessive deleterious genes in a segment of HLA-DR53 haplotypes.

Adult↗