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Biomedical subjects

M L Jones

Publications and source records attributed to M L Jones.

At least 73 records · Page 4Linked to original sources
PubMed1996

Epidemiologic assessment of laboratory animal allergy among university employees.

The prevalence of, and risk factors for, laboratory animal allergy (LAA) among university employees were evaluated in a cross-sectional university-based study. A stratified random sample was drawn based on current or no laboratory animal exposure and smoking status. Participants received a modified ATS questionnaire; spirometry; methacholine challenge; and intradermal allergen skin tests. One hundred three currently animal-exposed and 113 never-occupationally-exposed employees participated. Controlling for smoking, currently exposed workers were significantly more likely than controls to describe work-related cough, odds ratio (O.R.) = 6.87; wheeze, O.R. = 12.96; and chest tightness, O.R. = 2.89. Skin test reactivity to non-animal antigens was associated in a dose-response fashion with both upper and lower respiratory symptoms, O.R. = 1.45 and 1.65, respectively, for each additional positive skin test. Exposed workers were significantly more likely than controls to react to methacholine at either 10 or 25 mg/ml, while controlling for smoking status, prior allergy, or asthma. Multiple logistic regression analysis revealed history of hay fever, family history of allergy, non-animal skin test positivity, animal bites, age, and smoking status to each be associated with work-related respiratory symptoms. These data suggest that atopy and smoking status are risk factors for LAA symptoms. Smoking was associated with work-related respiratory symptoms among animal-exposed workers, but not with skin test positivity. It is therefore recommended that periodic screening evaluations be performed on laboratory animal workers and that workers who are atopic, are smokers, or are symptomatic be placed in low exposure settings. These data further, support the need for efficient exhaust ventilation, personal protective clothing and, among high risk workers, the use of efficient respiratory protection.

Animals↗
PubMed1996

The utility of preliminary surveys to detect the cause of acute metalworking fluid hazards.

This paper describes preliminary studies undertaken to optimize a later epidemiologic study, the aim of which was to identify a causative agent of adverse respiratory effects and dermatitis among production machinists. Two methods were used to rate coolant system hazards. The results of a voluntary plantwide questionnaire with an 18% participation rate showed that both dermatologic and respiratory symptoms were higher among machine operators than among maintenance or assembly workers, that symptoms were not more prevalent early in the week, and that dermatitis may be associated with smoking status; however, the questionnaire was not helpful in rating individual coolant system hazards. The hazard ratings provided by an in-plant expert panel were strongly associated with particular synthetic coolant containing an ethoxylated phenol; however, the resulting design for a later epidemiologic study could not be implemented due to changes in coolants used at the plant.

Chromatography, High Pressure Liquid↗
PubMed1996

People with mobility impairments in the United States today and in 2010.

This article presents a study undertaken to develop a population profile of people with mobility impairments in the U.S.A. today and to estimate the profile of people with mobility impairments in the year 2010. The profile was developed under contract to the U.S. Architectural and Transportation Barriers Compliance Board (Access Board) as part of a project to examine technical requirements for ramp slope and length. The profile was used to establish a representative (both today and in the future) sampling frame for human subjects in the current project, as well as to guide the Access Board in developing accessibility guidelines in the future. The present article highlights findings concerning mobility impairments in the population today and trends likely to influence the future prevalence of such impairments. The findings have implications for accessibility requirements and disability policy in general.

Activities of Daily Living↗
PubMed1996

A national survey of orthodontic facebow injuries in the UK and Eire.

There have been several reports of soft tissue injuries from orthodontic facebows in the dental and medical literature, but the magnitude of the problem in the UK and Eire has never been previously investigated. In order to obtain information, questionnaires were distributed to 1682 Dental practitioners providing orthodontic treatment in the UK and Eire. A total of 1117 (66 per cent) replied. Of these 859 (77 per cent) reported using Kloehn type facebows. Thirty-one practitioners (3.6 per cent) gave details of 33 injuries from Kloehn type facebows. The results of this questionnaire are compared and discussed with previous reports in the dental and medical literature. The relative effectiveness of extra-oral traction safety products is discussed.

Adolescent↗
PubMed1995

Noncooperativity of biotin binding to tetrameric streptavidin.

Streptavidin tetramers have been separated according to their biotin content by anion exchange chromatography. Biotin-free and biotin-saturated streptavidin were coincubated. Streptavidin at intermediate ligation levels, i.e., with one, two, or three molecules of bound biotin, accumulates over time. A steady state distribution of ligation levels is reached after 2 days. When biotin was allowed to redistribute starting from homogeneous populations containing two molecules of biotin per tetramer, a similar steady state distribution of ligation levels was observed, thereby demonstrating an equilibrium distribution. Quantification of this equilibrium indicates that biotin binds to streptavidin with no cooperativity.

Bacterial Proteins↗
PubMed1995

Role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in acute lung injury in rats.

The role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in the pathogenesis of acute lung injury in rats after intrapulmonary deposition of IgG immune complexes or intratracheal administration of LPS has been assessed. Critical to these studies was the cloning and functional expression of rat MIP-1 alpha. The resulting product shared 92% and 90% homology with the known murine sequence at the cDNA level and protein level, respectively. Recombinant rat MIP-1 alpha exhibited dose-dependent chemotactic activity for both rat and human monocytes and neutrophils, which could be blocked by anti-murine MIP-1 alpha Ab. Rat MIP-1 alpha mRNA and protein expression were determined as a function of time in both injury models. A time-dependent increase in MIP-1 alpha mRNA in lung extracts was observed in both models. In the LPS model, MIP-1 alpha protein could also be detected in bronchoalveolar lavage (BAL) fluids by Western blot analysis. Anti-MIP-1 alpha administered at commencement of IgG immune complex- or LPS-induced injury resulted in significant reductions in BAL neutrophils as well as in injury as measured by pulmonary vascular permeability. Under such conditions, in both models TNF-alpha content in BAL fluids was substantially reduced as compared with BAL fluids from positive control animals. These findings suggest that rat MIP-1 alpha plays an important role in the development of lung injury in these neutrophil-dependent models. The role of MIP-1 alpha seems to be related to production of TNF-alpha, which in turn up-regulates vascular adhesion molecules required for neutrophil influx.

Amino Acid Sequence↗
PubMed1995

Regulatory effects of intrinsic IL-10 in IgG immune complex-induced lung injury.

IL-10 has regulatory effects in vitro on cytokine production by activated macrophages. In the IgG immune complex model of lung injury, exogenously administered IL-10 has been shown to suppress in vivo formation of TNF-alpha, up-regulation of vascular ICAM-1, neutrophil recruitment, and ensuing lung injury. In the current study, we sought to determine whether endogenous IL-10 is playing a regulatory role in the lung inflammatory response. On the basis of lung mRNA and ELISA measurements, IL-10 induction was found during development of inflammation in the IgG immune complex model of lung injury. Blocking of IL-10 by Ab resulted in a 52% increase in lung vascular permeability, a 56% increase in TNF-alpha activity in bronchoalveolar lavage fluids, and a 47 to 48% increase in bronchoalveolar lavage neutrophils and lung myeloperoxidase content. These findings suggest that IL-10 is an important natural regulator of lung inflammatory injury after deposition of IgG immune complexes.

Animals↗
PubMed1995

Compartmentalized roles for leukocytic adhesion molecules in lung inflammatory injury.

By using the model of acute injury caused by intrapulmonary deposition of IgG immune complexes, blocking mAb to CD11a, CD11b, L-selectin, and intercellular adhesion molecule-1 (ICAM-1) were administered either i.v. or intratracheally (i.t.). The effects of these interventions were assessed according to lung injury, lung content of myeloperoxidase (MPO), TNF-alpha, and cellular content in bronchoalveolar lavage (BAL) fluids, and up-regulation of pulmonary vascular ICAM-1. In animals treated i.v. with Abs to CD11a, L-selectin, or ICAM-1 lung injury was significantly attenuated in parallel with reduced lung content of MPO. Under similar conditions, treatment with anti-CD11b had no effect. However, when the same mAb were administered i.t., anti-CD11a and anti-L-selectin were without protective effects, whereas i.t. administered anti-CD11b and anti-ICAM-1 were each highly protective. The protective effects of anti-CD11b were related to profound reductions in BAL levels of TNF-alpha, pulmonary vascular up-regulation of ICAM-1, and lung content of MPO. The protective effects of i.t.-administered anti-ICAM-1 were not associated with reduced BAL levels of TNF-alpha. Protective effects of mAb were also reflected in reductions of retrievable neutrophils in BAL fluids. mAb to rat CD11b and CD18 but not to rat CD11a suppressed in vitro production of TNF-alpha by immune complex-stimulated rat alveolar macrophages. The mAb did not reduce NO2-/NO3- generation in stimulated macrophages but all mAb (except anti-ICAM-1) reduced O2- responses in macrophages. These data suggest a compartmentalized role for adhesion molecules in lung inflammatory injury after intraalveolar deposition of IgG immune complexes, with CD11a, L-selectin, and ICAM-1 being important in the vascular compartment for neutrophil recruitment, whereas in the alveolar compartment CD11b and ICAM-1 (but not CD11a and L-selectin) seem to play key roles.

Alveolitis, Extrinsic Allergic↗
PubMed1995

Pattern of injury and the role of neutrophils in reperfusion injury of rat lung.

Using a rat lung model, we sought to characterize the time course for ischemia-reperfusion injury and the role of neutrophils in the development of injury. Adult male Long-Evans rats underwent left thoracotomy with dissection and clamping of the left pulmonary artery, bronchus, and vein for 90 min, resulting in complete left lung ischemia. The lungs were then ventilated and reperfused for up to 4 hr. Time-matched sham animals underwent the identical thoracotomy and hilar dissection, but the lungs were not rendered ischemic. Using vascular permeability of 125I-labeled bovine serum albumin as a measure of reperfusion injury, a bimodal pattern of injury was observed. Compared to sham controls, animals undergoing ischemia-reperfusion demonstrated a significant early phase of lung injury at 30 min of reperfusion (P < 0.0001), followed by partial recovery. A second peak of lung injury was noted after 4 hr of reperfusion (P < 0.001). Myeloperoxidase activity in reperfused lung tissue, a measure of neutrophil sequestration, increased during the reperfusion time course. To determine the role of neutrophils in the development of lung reperfusion injury, additional animals undergoing the identical ischemia-reperfusion protocol received either rabbit anti-rat neutrophil serum or preimmune serum the day prior to operation. Profound neutropenia (< 75/mm3 blood) was confirmed by differential leukocyte counts. Neutropenia had no protective effect against microvascular permeability at 30 min of reperfusion, but there was a significant reduction in lung injury at 4 hr (P < 0.005). We conclude that, during lung ischemia-reperfusion, there is a bimodal pattern of injury, consisting of both neutrophil-independent and neutrophil-mediated events.

Animals↗
PubMed1995

Ethylene-regulated expression of a carnation cysteine proteinase during flower petal senescence.

The senescence of carnation (Dianthus caryophyllus L.) flower petals is regulated by the phytohormone ethylene and is associated with considerable catabolic activity including the loss of protein. In this paper we present the molecular cloning of a cysteine proteinase and show that its expression is regulated by ethylene and associated with petal senescence. A 1600 bp cDNA was amplified by polymerase chain reaction using a 5'-specific primer and 3'-nonspecific primer designed to amplify a 1-aminocyclopropane-1-carboxylate synthase cDNA from reverse-transcribed stylar RNA. The nucleotide sequence of the cloned product (pDCCP1) was found to share significant homology to several cysteine proteinases rather than ACC synthase. A single open reading frame of 428 amino acids was shown to share significant homology with other plant cysteine proteinases including greater than 70% identity with a cysteine proteinase from Arabidopsis thaliana. Amino acids in the active site of cysteine proteinases were conserved in the pDCCP1 peptide. RNA gel blot analysis revealed that the expression of pDCCP1 increased substantially with the onset of ethylene production and senescence of petals. Increased pDCCP1 expression was also associated with ethylene production in other senescing floral organs including ovaries and styles. The pDCCP1 transcript accumulated in petals treated with exogenous ethylene within 3 h and treatment of flowers with 2,5-norbornadiene, an inhibitor of ethylene action, prevented the increase in pDCCP1 expression in petals. The temporal and spatial patterns of pDCCP1 expression suggests a role for cysteine proteinase in the loss of protein during floral senescence.

Amino Acid Sequence↗
PubMed1995

Disparate effects of nitric oxide on lung ischemia-reperfusion injury.

BACKGROUND: Inhaled nitric oxide (.NO) has been found to be a potent pulmonary vasodilator. We assessed whether .NO, through this function or others, could alleviate lung reperfusion injury. METHODS: Rats underwent thoracotomy, with clamps used to create left lung ischemia. After 90 minutes of ischemia, clamps were released, permitting reperfusion for either 30 minutes or 4 hours. Additional animals received inhaled .NO via the ventilator to determine its effects on reperfusion injury. RESULTS: Lung injury, measured by increased vascular permeability using iodine-125-labeled bovine serum albumin leakage, was significantly increased in ischemic-reperfused animals compared with time-matched shams not undergoing ischemia. Inhaled .NO delivered at the start of reperfusion worsened injury at 30 minutes but was protective at 4 hours. The increased injury could be avoided either by delaying .NO for 10 minutes or by treating the animals with superoxide dismutase before reperfusion. .NO reversed postischemic pulmonary hypoperfusion at 4 hours, as measured by labeled microspheres. Lung neutrophil content was significantly reduced at 4 hours in .NO-treated animals. CONCLUSIONS: .NO is toxic early in reperfusion, due to its interaction with superoxide, but is protective at 4 hours of reperfusion, due to reversal of postischemic lung hypoperfusion and reduction of lung neutrophil sequestration.

Administration, Inhalation↗
PubMed1995

Expression of monocyte chemoattractant protein-1 and macrophage inflammatory protein-1 after focal cerebral ischemia in the rat.

Chemoattractant cytokines, the chemokines, play an important role in early events of inflammation at the site of tissue damage. We examined the expression of mRNA and the protein products of two such chemokines; i.e. monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1 alpha (MIP-1 alpha) in the ischemic brain tissue following middle cerebral artery occlusion (MCAo). The mRNA transcripts of MCP-1 and MIP-1 alpha were detected by Northern hybridization and reverse transcriptase polymerase chain reaction (RT/PCR), respectively, and the anatomic distribution of specific proteins was analyzed by immunohistochemistry. We found that MCP-1 mRNA was not expressed in the brains of normal rats or rats sacrificed 2 h after MCAo. 6 h after the induction of cerebral ischemia, weak expression of both mRNAs was detected in the ischemic tissue. mRNAs were expressed up to 48 h, and were markedly attenuated at 96 h. In the rats subjected to MCA occlusion, MCP-1 immunoreactivity was diffusely expressed and localized to the ischemic area, and was most intense at 48 h after MCA occlusion. Endothelial cells and macrophage-like cells expressed MCP-1 protein in the ischemic brain. The distribution and morphology of MIP-1 alpha immunoreactive cells were identical with activated astrocytes. We conclude that MCP-1 and MIP-1 alpha mRNAs and proteins are induced after cerebral ischemia in the rat. They may have a role in promoting inflammatory and/or repair processes in the ischemic brain, possibly by attracting or modulating inflammatory cells in the ischemic area.

Animals↗
PubMed1995

A study of the accuracy of predicted soft tissue changes produced by a computer software package (COG 3.4) in a series of patients treated by the Le Fort I osteotomy.

This study was performed to compare soft tissue movements resulting from a series of Le Fort I osteotomies with those predicted for the same cases by means of a computerised software package (COG 3.4). The source material consisted of serial lateral cephalometric radiographs for 25 consecutive patients that had received similar Le Fort I osteotomies primarily to correct an antero-posterior skeletal discrepancy. Generally it was found that many of the digitised points on the facial profile were surprisingly well predicted. In addition, the chin and profile changes resulting from mandibular auto-rotation also were reasonably well predicted. However, in a number of cases prediction was less consistent and this was particularly true in the region of the nose and lips. In such instances, initial size, thickness and the existing morphology of the soft tissues appeared to be important factors. The tendency of the software occasionally to 'cross-over' the plots for the upper and lower lip profile made the judgement in this area of predicted profile change difficult in some cases.

Adolescent↗
PubMed1995

Multiflex versus superelastic: a randomized clinical trial of the tooth alignment ability of initial arch wires.

Two arch wires commonly used for initial tooth alignment were compared with regard to their clinical effectiveness. The two arch wires tested were 0.0155-inch diameter multiple-stranded stainless steel wire (Dentaflex, Dentaurium, Optident, Yorkshire, England) and 0.014-inch diameter nickel-titanium alloy wire (NiTi, ORMCO Co., Monrovia, Calif.). Consecutive patients attending an orthodontic clinic for routine placement of a fixed appliance were randomly assigned one of these two initial arch wires. Good quality alginate impressions of the appropriate dental arch were taken before arch wire placement and also at the subsequent appointment, which was, on average, 6 weeks later. Seventy-four arches were used in this study. The degree of tooth alignment achieved for each wire type was compared with a Reflex Microscope (Reflex Measurement Ltd., Butleigh, England) to make detailed measurements on the resultant casts. The degree of initial alignment achieved with the two wires was similar over this 6-week period. However, some differences were found for the lower labial segment where the interbracket span is usually reduced and where the superelastic nickel-titanium wire was found to give improved alignment. No threshold of crowding was found where one arch wire performed better than the other.

Adolescent↗
PubMed1995

Significance of anti-LU8 in pregnancy.

Anti-LU8, an antibody defining a high-frequency antigen in the Lutheran system, was identified in the serum of a gravida 4 para 0 pregnant women who had never been transfused. The antibody consisted of both an IgM and an IgG1 component and was nonreactive in the antibody-dependent cell-mediated cytotoxicity (ADCC) assay. The red cells of the mother and 3 siblings of the patient typed as LU:8,14 and were incompatible with the patient's serum. The baby was born at term with a negative direct antiglobulin test and typed as LU:8,14. There was no clinical evidence of haemolytic disease of the newborn.

Adult↗
PubMed1995

Regulation of monocyte chemoattractant protein-1 gene expression and secretion in rat pulmonary alveolar macrophages by lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-1 beta.

Chemotactic cytokines coordinate the recruitment of leukocytes into the lung during pulmonary inflammation. In a previous study, we determined that rat pulmonary alveolar macrophages (PAMs) facilitate monocyte recruitment and activation in the lung during acute inflammatory lung injury, in part, through the inducible expression of monocyte chemoattractant protein-1 (MCP-1). MCP-1 is an 11 to 15 kD basic peptide that specifically mediates monocyte chemotaxis and activation. Inflammatory mediators that regulate the expression and secretion of MCP-1 by rat PAMs have not been identified. We determined that stimulation of resident rat PAMs with bacterial lipopolysaccharide (LPS), murine tumor necrosis factor-alpha, or human interleukin-1 beta resulted in the inducible expression of MCP-1 mRNA and the secretion of biologically active MCP-1. In contrast, phorbol myristate acetate, a nonphysiologic leukocyte activator, was significantly less effective in stimulating either enhanced MCP-1 mRNA expression or secretion of MCP-1. These results indicate that the expression of MCP-1 mRNA and the secretion of MCP-1 by rat PAMs are regulated by bacterial products (LPS) and inflammatory cytokines. Further, these results suggest PAMs are regulated by bacterial products (LPS) and inflammatory cytokines. Further, these results suggest that resident PAMs, through elaboration of MCP-1, may play a pivotal role in regulating recruitment and activation of monocytes in the lung during acute inflammatory lung injury.

Alkaloids↗
PubMed1995

A technique for the computerized identification of orthodontic instruments.

Increasingly, orthodontic instruments must leave the chairside or even the clinic in order to facilitate adequate sterilization. The tray system employed in an orthodontic clinic is outlined. Inevitably, there are problems with instruments being lost from these trays and finding some method for individual 'tagging', which is also resistant to autoclaving, would be a useful facility. To address this problem a robust procedure of automatic instrument identification, similar to bar coding, has been deployed. This system, termed matrix coding, not only facilitates easy instrument identification, but also allows every episode of clinical use and sterilization to be recorded. By such a method it could become possible to quickly establish when instruments are likely to require servicing, sharpening or replacement.

Computers↗