Biomedical subjects
L Hurst
Publications and source records attributed to L Hurst.
Characterisation of monoclonal antibodies to ovine interleukin-6 and the development of a sensitive capture ELISA.
A purified recombinant ovine (rOv) interleukin-6 (IL-6) was used to generate specific murine monoclonal antibodies (mAbs) and a polyclonal rabbit antisera to this cytokine. From the 31 initial hybridoma cell lines generated, three stable clones were established which secreted mAbs to rOvIL-6, as judged by a direct enzyme-linked immunosorbent assay (ELISA) and Western blotting. Their specificity was further confirmed by demonstrating that none of the mAbs recognised any of the six other irrelevant recombinant ovine cytokines tested by direct ELISA. All three mAbs displayed cross-reactivity with human and African green monkey IL-6 as demonstrated by direct ELISA and Western blotting. In contrast, the polyclonal antibodies only cross-reacted with bovine IL-6 and not with either of the human or monkey homologues. By combining a mAb with the polyclonal antisera a sensitive, IL-6-specific, capture ELISA was developed that had a sensitivity of 150 pg/ml. This detection system was unequivocally validated by demonstrating that native OvIL-6 could be detected in efferent lymph draining from a stimulated popliteal lymph node. In addition, one of the mAbs was shown to allow the detection of OvIL-6 by intracellular cytokine staining and flow cytometry.
The use of recombinant ovine IL-1beta and TNF-alpha as natural adjuvants and their physiological effects in vivo.
In the present study we have investigated the use of recombinant ovine IL-1beta and TNF-alpha both alone and in combination, as natural adjuvants in vaccination trials in sheep. Initial experiments were conducted to investigate the physiological effects of the cytokines in vivo and determine what dose could be administered without adverse pyrogenic effects. Even at the maximum dose tested (100 microg) the only significant physiological effect was a transient increase in body temperature of approximately 2 degrees C in sheep injected with TNF-alpha. Administration of either cytokine had profound effects on the levels of circulating leucocytes for up to 5 days postinjection. The incorporation of either IL-1beta or TNF-alpha in aqueous or Al(OH)3 vaccine formulations enhanced antibody responses to a recombinant antigen from the cestode parasite Taenia ovis. The addition of IL-1beta to aqueous vaccine formulations increased antibody responses 15-20-fold and in Al(OH)3 formulations by three to six fold. TNF-alpha stimulated 1.5 to six-fold and 2.5 to seven-fold increases in antibody levels in aqueous and Al(OH)3-based formulations, respectively, in a dose-dependent manner. The addition of either cytokine to Quil A or IFA vaccines did not enhance the antibody levels elicited. When 10 microg of both IL-1beta and TNF-alpha were incorporated in the aqueous or Al(OH)3 vaccine formulations, increases of 21-fold and 25-fold, respectively, were observed in antibody levels. The adjuvant activity of IL-1beta and TNF-alpha in combination in the Al(OH)3-based vaccine resulted in antibody levels commensurate with those obtained using Quil A or IFA.
Expression of ovine interleukin-2 cDNA in Escherichia coli.
The expression plasmids pGEX-2T and pT7-7 were used to express ovine (Ov) IL-2 cDNA in Escherichia coli. The pGEX-2T vector contained glutathione-S-transferase (GST) as the affinity handle and resulted in high level expression of the GST-IL-2 fusion protein. However, only a small proportion of this fusion protein was present in the soluble fraction. The insoluble fraction was extracted with a detergent, sarkosyl, and even though a large amount of fusion product was obtained, it would not bind to glutathione beads efficiently. Thus, only low yields of biologically active rOvIL-2 were obtained. The yields were not significantly improved when other detergents were used for extraction except for a non-ionic detergent, Zwittergent 3-14, where there was a two- to three-fold increase compared with extraction with sarkosyl. An alternative vector, pT7-7 was used with a 6 x histidine tag followed by a thrombin cleavage site at the amino terminus of the mature ovine IL-2 protein to allow affinity purification by Ni-NTA resin. A large proportion of the rOvIL-2 was partitioned to the insoluble fraction. This expression system was more useful than the pGEX-2T as large quantities of biologically active rOvIL-2 of at least 10 mg l-1 were obtained. The presence of the six histidine residues at the amino end of rOvIL-2 did not reduce its biological activity. Both systems yielded rOvIL-2 with a high specific activity of about 1 x 10(7) U mg-1 as measured by the ability to maintain proliferation of ovine ConA lymphoblasts. Recombinant OvIL-2 was active on bovine but not porcine ConA lymphoblasts.
Analysis of ovine IL-1 beta production in vivo and in vitro by enzyme immunoassay and immunohistochemistry.
A monoclonal antibody (mAb) specific for ovine IL-1 beta was produced and, in conjunction with a polyclonal rabbit antiserum, used to develop a sensitive enzyme immunoassay (EIA) for ovine interleukin 1 beta (IL-1 beta). The mAb neutralised the activity of recombinant ovine IL-1 beta (rOvIL-1 beta) and native OvIL-1 in an ovine thymocyte proliferation assay. However, it did not neutralise the biological activity of rOvIL-1 beta in the murine NOB1/CTLL assay. The mAb did not react with rOvIL-1 alpha, IL-2, IL-4, IL-8, tumor necrosis factor-alpha, gamma-interferon or recombinant human IL-1 beta in indirect EIA. Immunohistological staining of activated alveolar macrophages and frozen lymph node sections sections demonstrated that the mAb detected IL-1 beta secreted by ovine macrophages (CD11c-positive). The EIA was highly sensitive, detecting less than 50 pg ml-1 of rOvIL-1 beta and low levels of native IL-1 beta in supernatants from lipopolysaccharide-stimulated macrophages. The EIA did not detect heat-inactivated IL-1 beta.
ED use by older victims of family violence.
STUDY OBJECTIVE: To determine the nature and frequency of ED use by victims of physical elder abuse. METHODS: Community-dwelling victims of abuse were identified through a state elderly protective service program independent of the health care system in a geographic area served by two EDs. ED records were reviewed and abstracted to determine if and how victims used emergency services. RESULTS: During a 7-year period, 182 elderly victims of physical abuse were identified in the catchment area of the study, and 114 (62.6%) had been seen in one or both EDs at least once during a 5-year "window" surrounding the initial identification of abuse. These 114 individuals accounted for 628 visits (median 3, range 1-46); 30.6% of visits resulted in a hospital admission. An ordinal system was used that assigned a probability of any single ED visit being referable to abuse; 37.8% of subjects had at least one visit categorized as being of high probability, and 66% of subjects had at least one visit that resulted in an injury-related chief symptom or ICD-9 discharge diagnosis. CONCLUSION: Elder abuse victims have substantial interactions with EDs and these visits frequently result in admission. Strategies that identify elder abuse in less acute settings and effectively address the needs of victims would improve quality of life and likely result in substantial savings in health care expenditures.
Risk factors for reported elder abuse and neglect: a nine-year observational cohort study.
To determine longitudinal risk factors for elder abuse and neglect, an established cohort of community-dwelling older adults (n = 2,812) was linked with elderly protective service records over a 9-year follow-up period. Protective services saw 184 (6.5%) individuals in the cohort for any indication, and 47 cohort members were seen for corroborated elder abuse or neglect for a sampling adjusted 9-year prevalence of 1.6% (95% CI 1.0%, 2.1%). In pooled logistic regression, age, race, poverty, functional disability, and cognitive impairment were identified as risk factors for reported elder mistreatment. Additionally, the onset of new cognitive impairment was also associated with elder abuse and neglect. Because the mechanism of elder mistreatment case-finding in this study was a social welfare system (protective services), the influence of race and poverty as risk factors is likely to be overestimated due to reporting bias.
Older adults. An 11-year longitudinal study of adult protective service use.
BACKGROUND: Little is known about the epidemiology of adult protective services agency (APS) utilization, the state entities charged with assessment and advocacy for disenfranchised older adults. OBJECTIVE: To determine the prevalence of utilization by older adults and risk factors for APS. METHODS: A longitudinal study using the New Haven Established Population for Epidemiologic Studies in the Elderly population, a cohort of 2812 community-dwelling adults who were older than 65 years in 1982. The main outcome measure was referral to the state ombudsman on aging for protective services. RESULTS: Over the 11-year follow-up period, 209 cohort members (7.4%) were referred to the ombudsman 302 times as protective service cases for a community prevalence of 6.4% after adjusting for the sampling strategy of the cohort. Self-neglect was the most common indication for referral (73% of the cases). While in bivariate analyses a variety of baseline sociodemographic features, functional impairments, medical conditions, and social network factors were associated with APS use, in multivariable analysis only sociodemographic variables remained independent risk factors including low income (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.8 to 3.9), nonwhite race (OR, 2.2; 95% CI, 1.3 to 3.7), and age older than 75 years at cohort inception (OR, 1.9; 95% CI, 1.1 to 3.0). CONCLUSIONS: Prevalence of APS use by older adults is substantial, and sociodemographic features were the most compelling risk factors in our cohort. As the population ages, the number of older adults at risk for abuse, neglect, self-neglect, exploitation, and abandonment will increase; physicians will need to become familiar with APS referral pathways and mandatory reporting laws in their states.
Cloning and sequencing of an ovine interleukin-5 cDNA.
Interleukin-5 (IL-5) is a T-cell derived cytokine which stimulates eosinophil production and activation in human, mice and sheep. IL-5 is active as a growth factor for mouse but not human B cells. The role of IL-5 on ruminant B cells has not been clearly defined. By hybridisation with human IL-5 cDNA, the ovine IL-5 gene was isolated from a liver genomic library. The IL-5 cDNA was obtained by reverse-transcriptase PCR using primers designed from the 5' and 3' coding sequence derived from the ovine IL-5 gene. The sequences of the cDNA shows that there is 79% and 73% nucleotide homology with the human and mouse sequences. The ovine IL-5 cDNA encoded a protein of 132 amino acids and the level of amino acid homology with human and mouse IL-5 is 64% and 56%, respectively. Two cysteine residues are conserved in ovine, human and mouse IL-5. There are two potential N-linked glycoyslation sites in ovine IL-5.
Herpes simplex virus type 1 infection of mouse astrocytes treated with basic fibroblast growth factor.
We explored a possible role for the basic fibroblast growth factor (FGF) receptor during herpes simplex virus type 1 (HSV-1) infection of primary mouse astrocytes, glial cells of the central nervous system known to express FGF receptors. Plaque reduction experiments showed that treatment of astrocyte monolayers with human recombinant basic FGF failed to inhibit HSV-1 infectivity, although treatment with either heparin or poly-L-lysine reduced it by approximately 100%. Identical results were obtained when monolayers of human embryonic lung fibroblasts or African green monkey kidney cells were treated with FGF, heparin or poly-L-lysine prior to HSV-1 infection. We conclude that the basic FGF receptor is not involved in the uptake of HSV-1 during productive infection of astrocytes. Our findings suggest that this molecule is not the predominant cellular receptor for HSV-1 among vertebrate cells and plays no role in defining HSV-1 neurotropism in vivo.
Tuberculosis of the hand and wrist.
Explore the source record for details and available documents.
Material prepared from normal brain inhibits migration of leukocytes from Huntington's disease patients.
Material inhibiting migration of leukocytes in vitro from Huntington's disease patients, was obtained from human brain removed at autopsy. The active material was present in brainstem, basal ganglia and cerebellum but not in cerebral cortex. It could be recovered at autopsy up to 21.5 h after death, but not from patients who had died following prolonged anoxia. It was susceptible to heating and to freezing and thawing. Its activity was preserved in acid medium to pH 3, and its iso-electric point was around pH 5. Activity was present in the fraction eluted from gel filtration with molecular weight of 1.9 X 10(5). Protein, carbohydrate, lipid and nucleic acid could be identified in the active material, and its activity depended on intact protein and carbohydrate moieties. Sialic acid, although present, did not contribute to antigenicity. Extraction with lipid solvents abolished activity.
Effects of low-modulus coatings on pin-bone contact stresses in external fixation.
The intent of this study was to investigate the stress distribution in cortical bone around fracture fixation pins and around pins coated with various polymeric and elastomeric materials. Since these interface stresses cannot be measured directly, a photoelastic technique was employed and stresses were measured in two-dimensional bone models fabricated from sheets of epoxy resin. Our results showed that when a fixation pin was loaded in compression, the compressive stress measured in the model was greatest at the pin-model interface. The magnitude of the compressive stress was found to diminish steeply away from the hole in a log decrement distribution which was asymptotic to the value of the average stress in the model. When polymeric and elastomeric materials were applied as pin coatings and the performance of the coated pins was compared to that of uncoated pins of the same overall diameter, a reduction of the maximum stress in the bone model was demonstrated. Among the coatings tested, we found that of the polymeric materials ultrahigh molecular weight polyethylene (UHMWPE) was most effective at reducing the peak cortical stress magnitude. The most effective coating material overall was found to be silicon elastomer. Computation of stress values in models loaded through stainless-steel pins and through pins coated with 1-mm silicon elastomer showed that the presence of the elastomer layer caused a reduction of about 50% in the maximum compressive stress in the model.
Uptake of Zn++ and aflatoxin from perlite and liquid culture by Zea mays seedlings.
Explore the source record for details and available documents.
An unusual first branchial cleft cyst.
First branchial cleft anomalies have been documented with increasing frequency within the past decade, with more than 200 cases reported to date. A case of a first branchial cleft cyst with some unusual features is presented. The literature of such anomalies is reviewed, with some distinct clinical differences being noted between cysts and other branchial cleft anomalies.
Letter: Disruption of the family.
Explore the source record for details and available documents.
Parenteral cephalexin in a general surgical unit.
Explore the source record for details and available documents.