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Biomedical subjects

J Ellis

Publications and source records attributed to J Ellis.

At least 307 records · Page 17Linked to original sources
PubMed1984

Structure and organization of genes for sporozoite surface antigens.

The major surface antigen (circumsporozoite-protein) of the sporozoite stage of Plasmodium knowlesi has been cloned and characterized. The gene is notable for the presence of a 36 base pair unit repeated in tandem 12 times. These repeats may function at the DNA level in regulating gene expression and at the protein level in providing multiple copies of a single epitope (repitope) as part of a protein designed to evade and decoy the immune system.

Amino Acid Sequence↗
PubMed1984

DNA cloning of Plasmodium falciparum circumsporozoite gene: amino acid sequence of repetitive epitope.

A clone of complementary DNA encoding the circumsporozoite (CS) protein of the human malaria parasite Plasmodium falciparum has been isolated by screening an Escherichia coli complementary DNA library with a monoclonal antibody to the CS protein. The DNA sequence of the complementary DNA insert encodes a four-amino acid sequence: proline-asparagine-alanine-asparagine, tandemly repeated 23 times. The CS beta-lactamase fusion protein specifically binds monoclonal antibodies to the CS protein and inhibits the binding of these antibodies to native Plasmodium falciparum CS protein. These findings provide a basis for the development of a vaccine against Plasmodium falciparum malaria.

Amino Acid Sequence↗
PubMed1984

Monoclonal antibody LICR-LON-E36 recognizes gonadotrophs in female rat pituitaries.

The distribution of the antigen localized by monoclonal antibody LICR-LON-E36 has been studied by means of light and electron microscopical immunocytochemical procedures on resin-embedded pituitaries from male and female rats. Using both immunoperoxidase and immunogold labeling techniques, the localization of LICR-LON-E36 has been compared with that obtained with antibodies against the beta subunit of rat luteinizing hormone (beta LH) and human follicle stimulating hormone (beta FSH), porcine adrenocroticotropic hormone (ACTH) and rat S-100. LICR-LON-E36 is localized in a portion of beta LH-containing cells in female rat pituitaries and where present both antigens are localized within the same storage granules. LICR-LON-E36 is rarely detectable within beta LH-containing cells of male rat pituitaries that also stain positively with anti-beta FSH antibodies. ACTH and S-100 were localized within different cell populations.

Adrenocorticotropic Hormone↗
PubMed1984

Malaise and fatigue.

Patients used to complain of not being "in the pink". Nowadays they are "bushed", "beat", or "washed out". They used to expect a simple diagnosis and treatment; now both are much more complex.

Adolescent↗
PubMed1983

Localization of a Plasmodium surface antigen epitope by Tn5 mutagenesis mapping of a recombinant cDNA clone.

A recombinant complementary DNA clone from Plasmodium knowlesi makes a beta-lactamase fusion polypeptide in Escherichia coli that reacts with a monoclonal antibody to a Plasmodium surface antigen. An epitope of the surface antigen was localized by transposon Tn5 mutagenesis mapping of the complementary DNA clone. The Tn5 mutation having the farthest 5' insert into the complementary DNA portion of the chimeric gene, giving the shortest truncated protein that maintained the ability to bind monoclonal antibody, defined the location of the epitope.

Antibodies, Monoclonal↗
PubMed1983

Cloning and expression in E. coli of the malarial sporozoite surface antigen gene from Plasmodium knowlesi.

The malarial sporozoite, the infective stage found in the salivary gland of the insect vector, bears highly immunogenic surface antigen(s). Repeated exposure to irradiated sporozoites induces protection against malaria in several host species, including man. Further, monoclonal antibodies that confer passive immunity react with the immunogenic surface determinants of different sporozoite species. One approach to prevent malaria, therefore, would be to produce a vaccine that induces high titres of circulating antibodies against the sporozoite surface determinant(s). However, production of such a vaccine has not been possible since sporozoites cannot be cultivated in vitro and, therefore, only limited amounts of surface antigen may be obtained. To overcome this problem, we have prepared mRNA from Plasmodium knowlesi-infected mosquitoes to construct a cDNA library. From this library we have isolated a clone that expresses the sporozoite surface antigen as a beta-lactamase fusion protein in the plasmid pBR322. This is the first potentially protective malarial antigen to be cloned by recombinant DNA technology.

Animals↗
PubMed1983

Automated analysis of stereotypic behavior induced by psychomotor stimulants.

A newly developed rotation sensing device has been applied to the continuous monitoring of animal movement. Animals treated with morphine, amphetamine or apomorphine display different stereotypic movements which can be distinguished by the apparatus. Initial studies have indicated that the apparatus is able not only to identify but also to quantitate some measures of stereotypic behavior. For example, the number and direction of rotations (a measure of motor asymmetry), frequency of changes in movement direction (a measure of stereotypic movement) and periods of cessation of movement are affected differentially with acute morphine, apomorphine or amphetamine treatment. Moreover, using this apparatus, morphine was shown to increase the degree of rotational asymmetry of normal animals and of animals with unilateral lesions of the nigrostriatal pathway.

Amphetamine↗
PubMed1983

Human hybridomas from patients with malignant disease.

Lymphocytes from 180 patients with a variety of malignant diseases were collected and fused with a human myeloma-derived line, LON-LICR-HMy2/CAM1. A total of 162 hybridomas was obtained. Only B lymphocyte markers were found on the surface of the fusion products. Flow cytometric analysis revealed a stably increased DNA content in the hybridoma cells. Some hybridoma supernatants were found to contain new Ig chains. Anti-tumour binding activity was found in 12 supernatants.

Antibodies, Monoclonal↗
PubMed1983

Unpredictable error in calculated bicarbonate homeostasis during pediatric intensive care: the delusion of fixed pK'.

Bicarbonate balance is usually calculated from indirect total CO2 values determined by blood-gas analysis. Total CO2 is computed from the Henderson-Hasselbalch equation, under the assumption that the pK' is constant or at most varies insignificantly. In pediatric patients in intensive care, we have found instances of large errors in this assumption. We join Natelson and Nobel in asserting that total CO2 should be measured. Little reliance should be placed on bicarbonate estimation.

Bicarbonates↗
PubMed1982

Sociological aspects of attenders and non-attenders of antenatal classes.

One hundred and eighty-six women delivering in a one-month period were questioned about their attendance at antenatal education classes and various sociological characteristics. Forty-three women had never attended antenatal classes: young women, unmarried women, Maori or Pacific Island women and women of low socio-economic status or educational achievement were disproportionately represented amongst the non-attenders. Non-attenders of antenatal classes also lacked knowledge about the classes and had more transport and child care problems when compared with attenders. The present antenatal classes are not being attended by those who would probably benefit most from education for parenthood.

Adult↗
PubMed1982

Competitive interaction of gallamine with multiple muscarinic receptors.

Gallamine, a cholinergic antagonist at the (nicotinic) neuromuscular junction possesses antimuscarinic potency in several systems. We report here that gallamine inhibited the binding of [3H] quinuclidinyl benzilate (QNB) in a competitive manner in the brainstem and forebrain of the rat. The occupancy curves derived from these studies suggest that gallamine has widely varying affinities for different subpopulations of muscarinic receptors, a finding which sets gallamine apart from classical muscarinic antagonists such as atropine and QNB. The greatest difference in affinities for gallamine occurred in the brainstem, where the data could be satisfactorily fitted to a two-site model, with 77% of the receptors having high affinity (Kd = 25 nM) and 23% low affinity (93 microM). Further, these affinities displayed rank order correlation with those of carbachol (an agonist), although gallamine has not, so far, displayed agonist (or partial agonist) activity. The finding that antagonists as well as agonists can display multiple affinities for muscarinic receptors suggests that there are fundamental differences among subpopulations of these receptors.

Animals↗
PubMed1982

Acute effects of testosterone on serum PGE2 levels in male dogs.

Serum prostaglandin levels are influenced by testosterone. To test the hypothesis that the effect of testosterone is mediated through the prostate gland, testosterone was given acutely to intact and to prostatectomized male dogs. Intact dogs responded to testosterone with an abrupt, transient rise in plasma PGE2 levels; prostatectomized dogs did not respond. We conclude that testosterone has an acute effect on the prostate gland which results in release of PGE2 into the blood stream.

Animals↗