Core assessment program for intracerebral transplantations (CAPIT).
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Activities of Daily Living↗
Biomedical subjects
R Watts
Publications and source records attributed to R Watts.
Identification of residues involved in polymorphic antibody binding epitopes on HLA-DR molecules.
Based on previous studies it was predicted that amino acids 4 or 25 of the DR4 beta 1 and DR7 beta 1 chains are involved in polymorphic antibody binding epitopes on DR4 or DR7 molecules. These predictions were tested by analyzing monoclonal antibody (mAb) binding to transfectants expressing mutant DR4 beta 1 or DR7 beta 1 chains with single amino acid substitutions at positions 4 or 25. Antibody binding to transfectants expressing additional DR4/7 beta 1 hybrids was also analyzed to assess further the contributions of four segments of the DR4 beta 1 or DR7 beta 1 chains: amino acids 1-20, 21-40, 41-97, and the beta 2 domain. Single amino acid substitutions at positions 4 and 25 of the DR4 beta 1 chain or DR7 beta 1 chain eliminate binding of several mAb to DR4 or DR7 molecules, documenting that these residues are involved in antibody epitopes. However, the data with the hybrid DR4/7 beta 1 chains indicate that some of these epitopes require contributions from both segments 1-20 and 21-40 of these DR beta chains, whereas other epitopes can be generated by placing the appropriate segment in the context of the other DR beta chain. In addition, the data with other mAb indicate that their epitopes are determined primarily by sequences within the 41-97 segment or in the beta 2 domain.
Amino Acids↗
Analysis of antibody reactivity in the sera of 42 patients with paraproteinaemia.
The clinical expression of disease in patients with conditions in which autoimmunity is thought to contribute to the pathogenesis of disease is the result of an unfortunate combination of predisposing and environmental factors. The presence of autoantibodies showing a variety of antigen specificities in sera from many of these patients has been closely correlated with particular spectra of organ involvement or tissue destruction. Their precise role in the disease process is as yet unclear. Sera from patients with paraproteinaemia also often contain autoantibodies to a variety of cell components, although symptoms of autoimmune disease are rarely found in this group of individuals. In this study of 42 sera from patients with paraproteinaemia we have confirmed the presence of autoantibodies in 33% (13/42) of samples. Amongst the autoantibodies detected were those to human neutrophils (3), U1RNP (8) and cardiolipin (4). In five sera, the immunoglobulin class of autoantibody did not correlate with that of the monoclonal band. This study extends previous reports of the repertoire of autoantibodies present in sera from patients with paraproteinaemia.
Antibodies, Anticardiolipin↗
Nursing diagnosis: implications for health, with particular concerns for community nursing.
As nursing terminology develops to include positive health/wellness related concepts, the appropriateness of nursing diagnoses is questioned. Nursing diagnoses have the potential to lead community nurses towards a reductionist and simplistic view of the complexities associated with community issues. Concerns and questions are raised in relation to the acceptance of nursing diagnoses in Australian community nursing practice.
Attitude to Health↗
Low-cost water supplies and their contribution to health.
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Africa↗
Independent analysis of the 16/6 idiotype lupus model. A role for an environmental factor?
The recent description of a lupus-like disease in normal mice after injections of human mAb that bind DNA and carry the common Id 16/6 Id has excited much attention. In an effort to reproduce this model we have performed two experiments using eight human mAb three of which bear the 16/6 Id. Despite using an injection protocol very similar to that of the original authors and waiting for up to 1 yr we were unable to detect any autoantibodies or any evidence of renal disease. We suspect that our failure to reproduce the model may be due to differences in either or both the batches of CFA used, or in the animal house environments. It supports the view that a mosaic of effects is required to induce clinical expression of an autoimmune disease.
Animals↗
The role of polymorphic HLA-DR beta chain residues in presentation of viral antigens to T cells.
The relative importance of 11 polymorphic positions in the HLA-DR7 beta 1 chain in T cell recognition of foreign antigens was investigated using transfectants expressing mutant DR7 beta 1 chains as APC for five rabies virus-specific T cell clones. The results indicate that multiple amino acids, located in both the beta-strands and alpha-helix of DR7 beta 1 in the model of a class II molecule, are involved in DR7-restricted T cell recognition of these antigens. Many of the substitutions appeared to reduce the affinity of an antigenic peptide for the mutant DR7 molecules but did not prevent binding. The heterogeneity of responses of the three G-specific T cell clones to presentation of the G11.3 peptide by several of the mutant DR7 molecules indicates that the T cell receptor (TCR) of each these clones requires a different view of the G11.3/DR7 complex and raises the possibility that the G11.3 peptide may bind to the DR7 molecule in more than one conformation.
Amino Acid Sequence↗
Surviving a plane crash.
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Accidents, Aviation↗
Characterization and partial purification of different factors with contraction-potentiating activities from neurohaemal organs of the locust.
Phe-Met-Arg-Phe (FMRF-NH2) and structurally related peptides enhance neuromuscular transmission and contraction of the M. extensor tibiae preparations of the locusts Locusta migratoria and Schistocerca gregaria (Walther et al.: Neurosci. Lett. 45:99-104, '84). Similar effects could also be obtained with extracts of locust ganglia (Walther and Schiebe: Neurosci. Lett. 77:209-214, '87). By using two HPLC systems, we have partially purified extracts of the unpaired median nerves (including their neurohaemal organs) of different locust ganglia. The biological activity of the extracts served as an estimate for the degree of purification. Six different bioactive fractions were identified migrating at and close to retention times of known -RFamide peptides with similar bioactivity. No fraction coeluted with authentic FMRF-NH2 or FLRF-NH2. We demonstrate that extensor tibiae muscle contractions were potentiated by HPLC fractions from raw material with -RF-NH2 immunoreactivity, but also by HPLC fractions from raw material without such immunoreactivity.
Animals↗
Stability of the mutagenicity in stored cigarette smokers' urine and extract.
Urine from cigarette smokers was analyzed for the effect upon mutagenic activity when stored for as long as 175 days. Frozen aliquots of urine were thawed out at various time points in the study and prepared for bioassay. These urine extracts were not bioassayed immediately, but rather refrozen until all of the unprocessed urine samples had eventually been prepared for bioassay. All extracts were obtained using cyanopropyl solid phase extraction techniques. At the end of 175 days, all extracts were bioassayed using a microsuspension assay of Salmonella typhimurium TA98. Urine from smokers was found to be mutagenic (14.4-30.9 revertants/ml equivalent) while a control set of urine from non-smokers was not. Data from the storage study when analyzed by analysis of variance techniques indicated no statistical loss of mutagens occurred over the 175-day period although near significance was observed (P = 0.054). This near significance was the result of decreasing mutant response as storage time increased for two of the higher doses tested.
Analysis of Variance↗
Effect of available surface water on levels of antidiuretic hormone (lysine vasopressin) and water and electrolyte metabolism of the Rottnest Island quokka (Setonix brachyurus).
A sensitive radioimmunoassay was developed to measure circulating levels of the neurohypophysial peptide lysine vasopressin (LVP) in the marsupial quokka (Setonix brachyurus), which is abundant on Rottnest Island off the coast of Western Australia. Animals from locations on the island where free water is completely absent were compared in midsummer with animals from sites where brackish water is available and utilized by the quokkas. In the animals from West End, where free water is absent, circulating levels of LVP averaged 89.2 +/- 19.6 pg/ml, which was significantly higher than the mean level of 35.6 +/- 15.8 pg/ml measured in individuals collected from the Lakes site with access to brackish drinking water. Rates of water and sodium turnover, measured with isotopes, were significantly greater in Lakes than West End animals, as were renal clearances of sodium, chloride, urea, and total osmolytes. Despite an obvious osmotic diuresis resulting from the ingestion of salty water, the Lakes animals were in better physical condition at the end of summer than the West End animals which lack free water, and these latter individuals showed signs of slight dehydration with elevated plasma and urinary electrolyte concentrations and osmolalities.
Animals↗
Identification of amino acids in HLA-DPw4b beta and -DR5 beta 1 chains that are involved in antibody binding epitopes using site-directed mutagenesis and DNA-mediated gene transfer.
Based on comparisons of the amino acid sequences of the beta chains of HLA class II molecules that do or do not bind the I-LR1 monoclonal antibody, we predicted that glutamic acid 56 of I-LR1-positive DPw2, DPw3, and DPw4b beta chains and the analogous glutamic acid 58 of I-LR1-positive DR5 beta 1 chains are involved in the I-LR1 epitope. Site-directed mutagenesis of DPw4b beta and DR5 beta 1 cDNAs was used to change the codons for glutamic acid 56 in DPw4b beta and glutamic acid 58 in DR5 beta 1 to the codon for alanine found in I-LR1-negative beta chains. Transfectants expressing wild-type DPw4b beta chains or DR5 beta 1 chains bind the I-LR1 monoclonal antibody, whereas transfectants expressing the mutant DPw4b beta or DR5 beta 1 chains do not bind I-LR1. Therefore, DPw4b beta glutamic acid 56 and DR5 beta 1 glutamic acid 58 are involved in the epitope recognized by the I-LR1 monoclonal antibody. Interestingly, the DR5 beta 1 glutamic acid----alanine 58 substitution also causes the loss of binding of two DR5-specific monoclonal antibodies to DR5 beta 1 molecules. Because the sequences of amino acids 36 to 64 of the DPw4b beta chain and 38 to 66 of the DR5 beta 1 chain are identical, these data raise some interesting issues about the formation of antibody epitopes on class II molecules.
Amino Acid Sequence↗
DNA antibody idiotypes: an analysis of their clinical connections and origins.
Approximately thirty common DNA antibody idiotypes have been described on hybridoma derived or affinity purified DNA-binding antibodies. There are associations between some idiotypes and the clinical manifestations of systemic lupus erythematosus although none are sufficiently firm to be clinically useful in identifying subsets of SLE or in assessing disease activity in individual patients. The expression of these idiotypes is not confined to DNA antibodies in SLE. They may be found in the serum from patients with a range of autoimmune rheumatic disorders, infectious disease and blood dyscrasias. In most cases the antigen binding specificity of the antibody bearing the idiotype is unknown. The precise relationship between the various idiotypes is becoming better understood with increasing availability of genetic and structural data. DNA antibody idiotype manipulation may provide a potential new therapeutic modality in SLE.
Antibodies, Antinuclear↗
Multiple regions of HLA-DR beta 1 chains determine polymorphic epitopes recognized by monoclonal antibodies.
To investigate the locations of antibody binding epitopes on HLA class II molecules, four DR4/7 beta 1 hybrid cDNA were constructed by exchanging the DNA encoding the NH2-terminal portions (amino acids 1 to 40) or the COOH-terminal portions (amino acids 41 to 94) of the first domains of DR4 beta 1- and DR7 beta 1-chains, in association with DNA encoding either the DR4 beta 1 or DR7 beta 1 second domains. Transfectants expressing a DR alpha cDNA and a wild-type DR4 beta 1 or DR7 beta 1 cDNA or one of four hybrid DR4/7 beta 1 cDNA were produced, and the binding to the transfectants of anticlass II mAb, which detect polymorphic epitopes on either DR4 or DR7 molecules, was analyzed. Four different patterns of mAb binding to the transfectants were observed, indicating that multiple regions of DR beta 1-chains play the predominant roles in the contributions of these chains to polymorphic epitopes recognized by mAb on intact molecules. The relevant regions of these chains and the number of mAb that recognize the associated polymorphic epitopes are: 1) the COOH-terminal portion of the first domain of DR4 beta 1; a DR4-specific mAb, 2) the NH2-terminal portion of the first domain of DR7 beta 1; two mAb, including a DR7-specific mAb, 3) the NH2-terminal portion of the first domain of DR4 beta 1; seven mAb, and 4) the second domain of DR4 beta 1; one mAb.
Amino Acid Sequence↗
Comparative yields of mutagens from cigarette smokers' urine obtained by using solid-phase extraction techniques.
Urine from cigarette smokers was prepared for mutagenicity testing by extracting mutagens with solid-phase extraction columns. Commercially available prepacked bonded silicas (octadecyl, cyclohexyl, cyanopropyl) were compared for their ability to concentrate the urinary mutagens. Recovered urinary metabolites were evaluated for mutagenic activity by using a microreversion assay with Salmonella typhimurium. Dose-response data indicated that while mutagens were recovered by all three adsorbents, samples prepared by using the bonded cyanopropyl columns yielded the most bioactivity and/or the least amount of test organism toxicity. Varying pH of the urine was found to influence only the basified samples in terms of mutagenic recovery with the cyanopropyl base. Combinations of different adsorbents were not found to offer significant advantages over use of a singular extraction adsorbent.
Adult↗
Use of bioassay methods to evaluate mutagenicity of ambient air collected near a municipal waste combustor.
An ambient air sampling study was conducted around a municipal waste combustor; a primary goal was to develop procedures and methods to evaluate the emissions of organic mutagens resulting from incomplete combustion of municipal waste. The products of incomplete combustion from incineration include complex mixtures of organics, particularly polycyclic aromatic compounds, which are present after atmospheric dilution and cooling in emissions as semi-volatile or particle bound organic compounds. Combustion emissions are generally recognized as a potential cancer risk since they contain many carcinogenic and mutagenic polycyclic aromatic hydrocarbons. Analyzing such a complex mixture for the presence of even a few selected chemicals is difficult and provides risk information on only a fraction of the chemicals present. Bioassay methods, however, may be directly applied to evaluate the mutagenic and potential carcinogenic activity of the complex organics from combustion emissions. The Salmonella (Ames) assay was used to determine the mutagenicity associated with particles from ambient air collected near a municipal waste combustor. Dose-response data was generated, and mutagenicity concentrations were calculated to demonstrate the utility of bioassay in assessing the potential impact of emissions from municipal waste combustion. This phase of study quantified mutagenicity concentrations in ambient air but did not detect organic mutagens that could be attributed to incinerator emissions.
Air Pollutants, Occupational↗
Analysis of the molecular specificities of anti-class II monoclonal antibodies by using L cell transfectants expressing HLA class II molecules.
Expressible HLA class II alpha- and beta-chain cDNA were used for DNA-mediated gene transfer to produce L cell transfectants expressing single types of human class II molecules. Cloned transfectants expressing nine different class II molecules were isolated: DR alpha: DR1 beta I, DR alpha: DR4 beta I, DR alpha: DR5 beta I, DR alpha: DR5 beta III (DRw52), DR alpha: DR7 beta I, DR alpha: DR4/7 beta IV (DRw53), DQ7 alpha: DQw2 beta, DQ7 alpha: DQw3 beta, and DPw4 alpha: DPw4 beta. These class II-expressing transfectants were used to analyze by flow cytometry the molecular specificities of 20 anti-class II mAb. These analyes indicate that some mAb are more broadly reactive than was previously thought based on immunochemical studies. In contrast, the narrow molecular specificities of other anti-class II mAb were confirmed by this approach. Transfectants expressing human class II molecules should be valuable reagents for studies of B cell and T cell defined epitopes on these molecules.
Animals↗
A newly characterized HLA-DP beta-chain allele. Evidence for DP beta heterogeneity within the DPw4 specificity.
cDNA clones corresponding to the DPw4 alpha- and DPw4 beta-chains were isolated from a cDNA library prepared from a DPw4 homozygous cell line, their nucleotide sequences were determined, and the corresponding amino acid sequences were deduced. This DPw4 alpha-chain is identical to the conserved DP alpha-chains from DPw4 and DPw2 haplotypes, although the DPw4 beta-chain (referred to as DPw4b beta) differs from all reported DP beta-chain sequences. The DPw4b beta-chain differs from the reported DPw4 beta sequence (referred to as DPw4a beta) at three amino acid positions in the first domain (36, 55, and 56). The DPw4b beta-chain sequence differs from the DPw2 beta-chain sequence only at position 69 in the first domain, suggesting that the lysine at position 69 in DPw4b beta and the glutamic acid at position 69 in DPw2 beta contribute to the epitopes that define "DPw4-ness" and "DPw2-ness," respectively. In addition, the patterns of sequence identities and differences among the DPw4b beta-, DPw4a beta-, DPw2 beta-, and DPw3 beta-chains suggest that the DPw4b beta sequence arose via a gene conversion event or a point mutation. The I-LR1 mAb, which was previously found to bind only to DPw2, DPw3, and DR5 molecules, binds to an L cell transfectant expressing the DPw4 alpha:DPw4b beta molecule. The DPw4b beta sequence provides the first evidence for structural heterogeneity within the DPw4 specificity.
Amino Acid Sequence↗