[3,4-benzpyrene in the exhaust gases of internal combustion engines (especially 2-cycle engines)].
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Air Pollution↗
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[Systems engineering and medicine--effects of systems engineering].
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Medicine↗
[Work efficiency and human engineering in nursing service. Organization and human engineering].
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Ergonomics↗
Committee on Prosthetics Research and Development Division of Engineering-National Research Council National Academy of Sciences--National Academy of Engineering. Annual summary report. Activities for year ended June 30, 1970.
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Academies and Institutes↗
Cellular engineering.
Cellular engineering applies the principles and methods of engineering to the problems of cell and molecular biology of both a basic and applied nature. As biomedical engineering has shifted from the organ and tissue level to the cellular and sub-cellular level, cellular engineering has emerged as a new area. A cornerstone of much of this activity is cell culture technology, i.e., the ability to grow living cells in the artificial environment of a laboratory. Cellular engineering includes the role of engineering in both basic cell biology research and in the making of products which use living cells, e.g., tissue engineering and bioprocess engineering. The former involves the use of living cells in the development of biological substitutes for the restoration or replacement of function, and the latter the use of living cells to manufacture a biochemical product, e.g., through the use of recombinant DNA technology. In fact, as biomedical engineering has expanded to include the cellular level, and bioprocess engineering has shifted in interest from microbial organisms to include mammalian cells, there are intellectual issues in which an interest is shared by these two formerly separate areas of engineering activity. Cellular engineering thus transcends the field of biomedical engineering.
Biomedical Engineering↗
[Successes and prospects for genetic engineering].
The review of literature (1970-1976) on problems of gene engineering is given. Gene engineering is pointed out to be a new method of modern biology and a new page of modern molecular genetics. Gene engineering detected a real possibility of artificial creating living hybrid organisms, i.e. constructing functional recombinant DNA molecules according to a project of investigator, but not to possibilities of crossing. The determination of gene engineering (in contrast with genetical engineering) is given in the first division of the article. Genetical engineering is a construction of hybrid organisms on the basis of recombination between non-homologous chromosomes cy crossing. Genetical engineering is based on sex crossing, thus the application of this method is restricted by crossability (i.e. experiments in vivo), which possibilities are determined by taxonomical limits. Gene engineering is a new method of operating directly with genes. It permits constructing in vitro any hybrid genomes desirable. There is no limits of combining ability for gene engineering. Three main stages of constructing hybrid genomes should be taken into account for the proper determination of gene engineering as a method of genome constructing: 1) the gene isolation; 2) their cross-linking in vitro; 3) the transfer of hybrid DNA into recipient cell or its genome. The cardinal stage of gene engineering is the construction of hybrid DNA, cross-linking any initial DNAs from any remote animals, plants and bacteria. All the methods known of gene isolation are described. The chemical method of gene isolation is based on that case, when DNA of some gene differs in its physico-chemical characteristics from total DNA, for example, DNAs of genes coding ribosomal RNAs or sea urchine histone DNA. Isolation of promotors and operators using DNA dependent RNA polymerase, which recognizes promotors, repressor and operator DNA, should also be considered as the chemical method of gene isolation. Restrictase method, which is also well known, is convenuent because the restricts have long enough sticky ends, which is important for the following gene cross-linking. The method of total restriction, reported by Lederberg et al. and Debabov et al., is described. The phage method (in particular, Shimada method) is given, permitting the direct integration of lambda phage into a number of sites of Escherichia coli chromosome. Gene engineering method of gene isolation is mentioned, in particular, the data of Kameron et al. on hybrid phages carrying DNA ligase gene, and Clark a. Carbon on hybrid plasmids carrying triptophane and arabinose operons genes. These methods are called "shot gun". Methods of gene isolation from higher organisms are less developed. A method of gene isolation using so called colony hybridization (according to Grünstein and Hognes) is also given...
Bacteriophages↗
Re-engineering the hospital: a house without rooms.
Re-engineering of health care systems is defined, and the experience with re-engineering at a medical center is discussed. Re-engineering is a business concept that involves totally redesigning work processes to achieve much higher efficiencies and quality; it should not be confused with cost cutting, downsizing, and continuous improvement. Re-engineering seeks to combine multiple jobs into one, empower workers and make them more accountable, sequence the elements of work more naturally, create greater flexibility, and blur or remove organizational boundaries. Re-engineering at The Ohio State University Medical Center began with the formation of an operations improvement team consisting of department heads. Work processes were selected for re-engineering and prioritized, and teams were created to identify activities calling for radical change, such as activities that wasted time, could be done on an outpatient basis, or were duplicative. It was concluded that the redesign had to focus on the entire medical center, not the individual departments. A list of the characteristics of a better organization was prepared and distributed to the staff, along with other documents to help them understand the need for change. The operations improvement team specified expected outcomes of the re-engineering, and each re-engineering team developed measures of these outcomes. Many of the recommendations submitted have been implemented. One innovation has been the consolidation of the duties of utilization-review nurses, continuity-of-care nurses, social workers, and patient-education nurses into a single job category. When the medication-use re-engineering team meets, it will not be re-engineering the pharmacy department, it will be addressing the drug-use process. A medical center is re-engineering itself so that it will be able to continue to meet the health care needs of the community it serves.
Efficiency, Organizational↗
Carcinogenic potential of gasoline and diesel engine oils.
Used gasoline engine oils are carcinogenic in mouse skin and mutagenic in Salmonella. The toxicity of fresh gasoline engine oils and that of fresh and used diesel engine oils are less well defined. The present studies examined the dermal carcinogenic potential of a series of fresh and used oils from both gasoline and diesel engines. The used oils represented a variety of operating conditions. The objective of the study was to assess the potential carcinogenic hazards associated with exposure to these materials. The majority of the used gasoline engine oils tested were carcinogenic although one oil, collected after a relatively short drainage interval, was inactive in the dermal carcinogenesis bioassay. Additionally, polycyclic aromatic hydrocarbon (PAH) concentrations were elevated in the used oils in comparison to the fresh oils. The fresh gasoline engine oils and both the fresh and used diesel engine oil samples were noncarcinogenic, and there was little evidence of elevated PAH levels in the used diesel engine oils. The carcinogenic potency of used oils from gasoline engines was related to drainage interval, but other factors such as contribution of the fuel due to blowby and driving cycle may also have been important. The used diesel engine oils were not carcinogenic even after extended use.
Animals↗
Re-engineering for dramatic improvement in the medication-use process.
Planning for re-engineering the medication-use process at a university hospital is described. In summer 1992 the University of Cincinnati Hospital hired a consultant on quality to help with work-process improvement and re-engineering. By early 1993, re-engineering for patient-focused care was under way. Within a year of the implementation of patient-focused care in a pilot unit, it was realized that all departments that provided direct and indirect care would also have to undergo re-engineering. In August 1994 a retreat was held to begin the re-engineering effort in the pharmacy department. The retreat participants set as goals of the re-engineering (1) support of the hospital's strategic initiatives, (2) getting the right drug to the right patient at the right time, (3) improved patient outcomes, and (4) reducing the pharmacy labor and drug budget. Pharmacy activities for re-engineering were identified, and two planning teams were created, a pharmacy production team and a pharmacy knowledge-transfer team. The production team was made responsible for re-engineering dispensing, inspecting, producing, storing, and transporting, and the knowledge-transfer team was assigned teaching, recording, treating, and monitoring. A detailed plan was prepared for each team to follow using a framework provided by the consultant and consisting of strategy, technology, process, and personnel. Careful planning and a consultant helped a university hospital prepare for organizationwide re-engineering.
Focus Groups↗
Analysis of the polycyclic aromatic hydrocarbon content of petrol and diesel engine lubricating oils and determination of DNA adducts in topically treated mice by 32P-postlabelling.
Engine lubricating oils are known to accumulate carcinogenic polycyclic aromatic hydrocarbons (PAHs) during engine running. Oils from nine petrol-powered and 11 diesel-powered vehicles, in addition to samples of unused oil, were analysed for PAH content and ability to form DNA adducts when applied topically to mouse skin. The levels of 19 PAHs, determined by GC, were in total, approximately 22 times higher in used oils from petrol engines than in oils from diesel engines. Male Parkes mice were treated with 50 microliters of oil daily for 4 days before they were killed and DNA isolated from skin and lung tissue. DNA samples were analysed by nuclease P1-enhanced 32P-postlabelling. Used oils from both diesel and petrol engines showed several adduct spots on PEI-cellulose plates at total adduct levels of up to 0.57 fmol/microgram DNA [approximately 60 times greater than in experiments with samples of unused oil in which adduct levels (0.01-0.02 fmol adducts/microgram DNA) were close to the limit of detection]. Higher adduct levels were generally formed by petrol engine oils than by diesel engine oils. Lung DNA contained similar total adduct levels to those in skin although the adduct maps were less complex. Total adduct levels correlated with extent of oil use in the engine, the total PAH concentration in oils and with the concentrations of certain individual PAHs present in the oils. An adduct spot that co-eluted with that of the major benzo[a]pyrene-DNA adduct accounted for 9-26% of the total adducts in skin DNA, and approximately 8% of the adducts in lung DNA, of mice treated with petrol engine oils. A major, and as yet unidentified, adduct spot comprised up to 30% of the total adducts in skin DNA, and up to 89% of the total adducts in lung DNA, of these animals.
Administration, Topical↗
Assessment of exposure to polycyclic aromatic hydrocarbons in engine rooms by measurement of urinary 1-hydroxypyrene.
OBJECTIVE: Machinists have an increased risk of lung cancer and bladder cancer, and this may be caused by exposure to carcinogenic compounds such as asbestos and polycyclic aromatic hydrocarbons (PAHs) in the engine room. The aim of this study was to investigate the exposure of engine room personnel to PAHs, with 1-hydroxypyrene in urine as a biomarker. METHODS: Urine samples from engine room personnel (n = 51) on 10 ships arriving in different harbours were collected, as well as urine samples from a similar number of unexposed controls (n = 47) on the same ships. Urinary 1-hydroxypyrene was quantitatively measured by high performance liquid chromatography. The exposure to PAHs was estimated by a questionnaire answered by the engine room personnel. On two ships, air monitoring of PAHs in the engine room was performed at sea. Both personal monitoring and area monitoring were performed. The compounds were analysed by gas chromatography of two types (with a flame ionisation detector and with a mass spectrometer). RESULTS: Significantly more 1-hydroxypyrene was found in urine of personnel who had been working in the engine room for the past 24 hours, than in that of the unexposed seamen. The highest concentrations of 1-hydroxypyrene were found among engine room personnel who had experienced oil contamination of the skin during their work in the engine room. Stepwise logistic regression analysis showed a significant relation between the concentrations of 1-hydroxypyrene, smoking, and estimated exposure to PAHs. No PAHs were detected in the air samples. CONCLUSION: Engine room personnel who experience skin exposure to oil and oil products are exposed to PAHs during their work. This indicates that dermal uptake of PAHs is the major route of exposure.
Carcinogens↗
Hydrophobicity engineering to increase solubility and stability of a recombinant protein from respiratory syncytial virus.
Site-directed mutagenesis has been employed to engineer the hydrophobic properties of a 101-amino-acid fragment from the human respiratory syncytial virus (RSV) major glycoprotein (G protein). When this protein was produced in Escherichia coli, more than 70% of the gene product was found as inclusion bodies, and the product recovered from the soluble fraction was severely degraded. Substitution of two cysteine residues for serine residues, did not significantly change the solubility or stability of the gene product. In contrast, a dramatic increase in both solubility and stability was achieved by multiple engineering of hydrophobic phenylalanine residues. As compared to the non-engineered protein, the fraction of soluble protein in vivo could be increased from 27% to 75%. Surprisingly, this effect was accompanied by a remarkable increase in stability. The in vitro solubility of the purified gene products was similarly increased approximately fivefold. Structural studies using circular dichroism suggest that the two engineered fragments have a distribution of secondary-structure elements similar to the non-engineered fragment. In addition, the two engineered G-protein variants were demonstrated to be at least in part antigenically authentic to the non-engineered gene product. These results demonstrate that engineering of hydrophobic residues can be used as a tool to increase the solubility and proteolytic stability of poorly soluble and labile proteins.
Amino Acid Sequence↗
Survival and impact of genetically engineered Pseudomonas putida harboring mercury resistance gene in aquatic microcosms.
The survival of wild-type and genetically engineered Pseudomonas putida PpY101 that contained a recombinant plasmid pSR134 conferring mercury resistance were monitored in aquatic microcosms. We used lake, river, and spring water samples. The density of genetically engineered and wild-type P. putida decreased rapidly within 5 days (population change rate k -0.87 approximately -1.00 day-1), then moderately after 5 to 28 days (-0.10 approximately -0.14 day-1). The population change rates of genetically engineered and wild-type P. putida were not significantly different. We studied the important factors affecting the survival of genetically engineered and wild-type P. putida introduced in aquatic microcosms. Visible light exerted an adverse effect on the survival of the two strains. The densities of genetically engineered and wild-type P. putida were almost constant until 7 days after inoculation in natural water filtered with a 0.45-micron membrane filter, or treated with cycloheximide to inhibit the growth of protozoa. These results suggested that protozoan predation was one of the most important factors for the survival of two strains. We examined the impact of the addition of genetically engineered and wild-type P. putida on indigenous bacteria and protozoa. Inoculation of genetically engineered or wild-type P. putida had no apparent effect on the density of indigenous bacteria. The density of protozoa increased in microcosms inoculated with genetically engineered or wild-type P. putida at 3 days after inoculation, but after 5 to 21 days, the density of protozoa decreased to the same level as the control microcosms.
Animals↗
Novel insulinoma cell lines produced by iterative engineering of GLUT2, glucokinase, and human insulin expression.
Cellular engineering studies in our group are directed at creating insulin-secreting cell lines that simulate the performance of the normal islet beta-cell. The strategy described in this article involves the stepwise stable introduction of genes relevant to beta-cell performance into the RIN 1046-38 insulinoma cell line, a process that we term "iterative engineering." RIN cells stably engineered to contain multiple copies of the human insulin gene exhibit a large increase in insulin content, such that they approach the content of human islets assayed in parallel. Analysis by high-performance liquid chromatography demonstrates that these engineered cell lines process human proinsulin to mature insulin with high efficiency. Cell lines that are further engineered to express the GLUT2 and glucokinase genes demonstrate stable expression of the three transgenes for the full lifetime of the lines produced to date (6 months to 1 year in continuous culture). Transplantation of the engineered cell lines into nude rats reveals that stably integrated genes are expressed at constant levels in the in vivo environment over the full duration of experiments performed (48 days). Several endogenous genes expressed in normal beta-cells, including rat insulin, amylin, sulfonylurea receptor, and glucokinase, are stably expressed in the insulinoma lines during these in vivo studies. Endogenous GLUT2 expression, in contrast, is rapidly extinguished during in vivo passage. The loss of GLUT2 is overcome in engineered cell ines in which transporter expression is provided by a stably transfected transgene. These results suggest that a potential advantage of the iterative engineering approach may be to preserve stability of function and phenotype, particularly in the in vivo setting.
Animals↗
Simplifying multiplex genome engineering in Saccharomyces cerevisiae with intron-mediated Random Assembly and INtegration (RAIN).
Engineering of multistep enzymatic pathways often involves extensive optimization of heterologous gene expression levels and requires cloning of promoter and open reading frames (ORFs) to generate expression cassettes. We present work on a nascent method for multiplex genome engineering in Saccharomyces cerevisiae that negates the requirement for cloning of expression cassettes. Our system, Random Assembly and INtegration (RAIN), uses intron-mediated homologous recombination (HR) for random in vivo assembly of exogenous promoter and ORF libraries, which are combined and cotransformed in a one-pot method. The libraries include consensus homology arms which target long terminal repeat regions of the Ty1 retrotransposon, providing over a hundred possible integration loci. In this way, our developmental system aims to negate the need for in vitro combinatorial cloning of promoters and ORFs to generate expression cassettes, simplifying in vitro DNA preparation before multiplex genome engineering. This paper presents findings from a series of experiments to demonstrate a proof of concept for the RAIN system. These include: the first reported use of intron-mediated assembly of promoters and ORFs for expression of a functional gene product; up to three markerless genomic integrations; and up to five integrations with antibiotic selection. We also present a number of innovations to improve integration efficiency during multiplex engineering in S. cerevisiae including: SGS1 gene knockout; disruption of heteroduplex rejection; modified Cas9 expression architecture; and overexpression of HR genes RAD52, MRE11, and RAD59. To demonstrate how our system can be used for single transformation phenotype engineering of multiple strains, we also transformed a library of methylotrophy associated genes to generate four new strains that were able to grow on a solid minimal medium with methanol as the sole additional carbon source. Our findings contribute to the ongoing efforts to improve multiplex genome engineering tools in S. cerevisiae, and provide the foundations for further development of a novel toolbox for generating useful genetic diversity for metabolic pathway engineering.
Saccharomyces cerevisiae↗
32P-postlabelling analysis of DNA adducts in the skin of mice treated with petrol and diesel engine lubricating oils and exhaust condensates.
Samples of unused or used petrol and diesel engine lubricating oils were applied to the shaved dorsal skin of 4- to 6-week-old male Parkes mice, either as a single treatment (50 microliters/mouse) or as four consecutive daily treatments (50 microliters/application). DNA isolated from the skin 24 h after the final treatment was digested to 3'-mononucleotides and analysed by 32P-postlabelling for the presence of aromatic adducts. Enhancement of sensitivity using butanol extraction or nuclease P1 digestion of the DNA hydrolysates led to the detection of up to eight adduct spots on polyethyleneimine-cellulose thin-layer chromatograms with samples of DNA from skin treated with used engine oils, at levels of 40-150 amol total adducts/micrograms DNA. Multiple treatments with the used oils gave rise to similar patterns of adducts in lung DNA. A single treatment of mouse skin with petrol engine exhaust condensate (50 microliters), or diesel engine exhaust condensate (50 microliters), containing 20 and 46 micrograms benzo[a]pyrene (BaP)/g respectively, gave rise to approximately 75 amol total adducts/micrograms DNA in skin. A significant proportion, 31 and 48% respectively, of the adducts formed by the petrol and diesel engine exhaust condensates co-chromatographed with the major BaP-DNA adduct, but with the used engine oils, only petrol engine oil, and not diesel engine oil, produced significant amounts of an adduct (22% of total) that corresponded to the BaP-DNA adduct.
Adenosine Triphosphate↗
Skin disorders in ship's engineers exposed to oils and solvents.
Ship's engineers are exposed to mineral oil and solvents in their work. This study was intended to investigate if the ship's engineers had an increased prevalence of skin disorders and whether any such increased risk could be linked to exposure to mineral oils and solvents. A self-administered questionnaire was sent to 700 male seamen from 3 Norwegian ferry countries. Of the 492 respondents, 169 were currently working as ship's engineers and 295 had never worked as ship's engineers. The outcomes eczema, acne, dry skin, and dermatitis and hand dermatitis were defined from the questionnaire. Prevalences of these skin disorders were compared between the groups. Logistic regression was used to elucidate explanatory variables further. When comparing current ship's engineers with those who had never worked as ship's engineers, the crude prevalence ratios were 1.7 (95% CI 1.1-2.7) for dry skin, 1.7 (95% CI 1.1-2.5) for any dermatitis, 1.3 (95% CI 0.66-2.67) for acne and 1.2 (CI 0.61-2.27) for eczema. The risk of these symptoms increased for the engineers in the regression analysis, after controlling for age, self-reported use of Stoddard solvent, and the use of fuel oil as hand cleansing agent. The increased prevalence of skin disorders found among ship's engineers in this investigation may be explained by direct contact with mineral oils and solvents.
Adult↗
Exposure to mineral oil mist and respiratory symptoms in marine engineers.
The purpose of the study was to see if marine engineers have an increased prevalence of respiratory symptoms, and if so whether it can be related to occupational exposures. A self-administered questionnaire was sent to 700 male seamen from three Norwegian ferry companies. Of the 492 respondents, 169 were currently working as marine engineers and 295 had never worked as marine engineers. The outcomes of cough and wheezing, chronic bronchitis, severe dyspnea, any dyspnea, and mucous membrane irritation (MMI) were defined from the questionnaire. Age and smoking-adjusted prevalences of these respiratory conditions were compared between the groups. Logistic regression was used to further elucidate the explanatory variables. The exposure assessment indicated an exposure (TWAC) to oil mist for marine engineers in the range from 0.12 to 0.74 mg/m3 (mean 0.45 mg/m3) When comparing current marine engineers with those who had never worked as marine engineers, the prevalence ratios were 1.38 (95% CI 1.0-1.9) for MMI, 1.53 (95% CI 1.2-1.9) for any dyspnea, and 1.63 (95% CI 1.0-2.6) for severe dyspnea. The differences remained for some of the symptoms after controlling for self-reported former asbestos exposure in the regression analysis. The increased prevalence of respiratory symptoms found among marine engineers in this investigation may partly be explained be oil-mist exposure, or more probably by a combination of past asbestos exposure and past and present oil-mist exposure.
Cross-Sectional Studies↗