PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Containment of Biohazards”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1992

Maintenance and killing efficiency of conditional lethal constructs in Pseudomonas putida.

Conditional lethal (suicidal) genetic constructs were designed and employed in strains of Pseudomonads as models for containment of genetically-engineered microbes that may be deliberately released into the environment. A strain of Pseudomonas putida was formed with a suicide vector designated pBAP24h that was constructed by cloning the host killing gene (hok) into the RSF1010 plasmid pVDtac24 and placing it under the control of the tac promoter. After hok induction in P. putida only 40% of surviving cells continued to bear the hok sequences within 4 h of induction; in contrast, 100% of the cells in uninduced controls bore hok. A few survivors that demonstrated resistance to hok-induced killing developed in P. putida, which may have been due to a mutation or physiological adaptation that rendered the membrane 'resistant' to hok. Conditional lethal strains of P. putida also were formed by inserting gef (a chromosomal homolog of hok) under the control of the tac promoter into the chromosome using a transposon. Constructs with chromosomal gef, as well as an RK2-derived plasmid construct containing gef, were only marginally more stable than the hok constructs; they were effective in killing P. putida when induced and within 2 h post-induction killing from either gef construct resulted in a 10(3)-10(5)-fold reduction in viable cell count compared to uninduced controls.

Cloning, Molecular↗
PubMed1993

Nature in the laboratory--nature as a laboratory. Considerations about the ethics of release experiments.

Field tests with genetically modified organisms go beyond the boundaries of the politically and morally neutralized space that normally surrounds scientific experiments. They enter public areas. As a social process of shaping nature they are political in a fundamental sense. Consequences of this observation concern the legitimacy of decisions and the legitimacy of deciding procedures. The political rights of citizens and their human rights can only be respected if these procedures are democratic. Without a more serious exploration of the specific circumstances of release tests--for example, the precise ecological context, the consequences for the future development of the affected ecosystem, the social consequences, and the possible institutional ways of establishing gene technology in agriculture--we do not really know what we are doing when we release transgenic organisms. Moral judgements today can therefore only be prima facie, not free from shortcomings. As responsible judges we must confess that we are still morally blind.

Containment of Biohazards↗
PubMed1993

Evaluating the fate of genetically modified microorganisms in the environment: are they inherently less fit?

Genetically modified microorganisms hold great promise for environmental applications. Nonetheless, some may have unintended adverse effects. Of particular concern for risk assessment is the simple fact that microorganisms are self-replicating entities, so that it may be impossible to control an adverse effect simply by discontinuing further releases of the organism. It has been suggested, however, that genetically modified microorganisms will be poor competitors and therefore unable to persist in the wild due to energetic inefficiency, disruption of genomic coadaptation, or domestication. Many studies support the hypothesis that genetically modified microorganisms are less fit than their progenitors, but there are a few noteworthy counter-examples in which genetic modifications unexpectedly enhance competitive fitness. Furthermore, subsequent evolution may eliminate the maladaptive effects of some genes, increasing the likelihood that a modified organism or its engineered genes will persist. Evaluating the likelihood that a genetically modified microorganism or its engineered genes will persist is a complex ecological and evolutionary problem. Therefore, an efficient regulatory framework would require such evaluations only when there are plausible scenarios for significant adverse environmental effects.

Bacteria↗
PubMed1993

The true meaning of 'exotic species' as a model for genetically engineered organisms.

The exotic or non-indigenous species model for deliberately introduced genetically engineered organisms (GEOs) has often been misunderstood or misrepresented. Yet proper comparisons of of ecologically competent GEOs to the patterns of adaptation of introduced species have been highly useful among scientists in attempting to determine how to apply biological theory to specific GEO risk issues, and in attempting to define the probabilities and scale of ecological risks with GEOs. In truth, the model predicts that most projects may be environmentally safe, but a significant minority may be very risky. The model includes a history of institutional follies that also should remind workers of the danger of oversimplifying biological issues, and warn against repeating the sorts of professional misjudgements that have too often been made in introducing organisms to new settings. We once expected that the non-indigenous species model would be refined by more analysis of species eruptions, ecological genetics, and the biology of select GEOs themselves, as outlined. But there has been political resistance to the effective regulation of GEOs, and a bureaucratic tendency to focus research agendas on narrow data collection. Thus there has been too little promotion by responsible agencies of studies to provide the broad conceptual base for truly science-based regulation. In its presently unrefined state, the non-indigenous species comparison would overestimate the risks of GEOs if it were (mis)applied to genetically disrupted, ecologically crippled GEOs, but in some cases of wild-type organisms with novel engineered traits, it could greatly underestimate the risks. Further analysis is urgently needed.

Bacterial Physiological Phenomena↗
PubMed1981

Assessment of environmental contamination associated with a mammalian cell transformation assay.

To estimate worker exposures to, and environmental contamination from, test chemicals and organic solvents used in an in vitro assay to assess the carcinogenic potential of chemicals, sodium fluorescein, a noncarcinogenic fluorescent material, was dissolved in tissue culture medium used to maintain early passage hamster embryo cells. Personal an environmental samples were taken over a 14-d period. The assay was performed according to standard procedures in a ventilated glove box or laminar flow safety cabinet. Considerably more than 99% of the chemical contamination found was recovered from the interiors of the glove box and hood and from disposable equipment. Contamination outside the containment units (less than 1 microgram) resulted from intralaboratory transport of chemicals, treated cultures, and contaminated equipment. We conclude that the standard operating particles and procedures provided adequate safeguards for personnel and the environment.

Animals↗
PubMed2000

Occupational standards for the protection of employees in biotechnology.

A growing number of employees are exposed to biological agents (BAs) at the workplace. Their handling can be associated with the risk of occupational illnesses like infections, allergic or toxic reactions. Several legal considerations are making requirements for the safe handling of BAs necessary. A specific risk assessment has to consider both the adverse health effects deriving from BAs and the exposure situation at the workplace. Industrial hygiene is of critical importance for safe handling, especially with regard to allergic reactions. Occupational surveillance programs can help to further minimize the risks, especially in preventing infections through vaccinations and in counseling persons with impaired immune systems. For accidental exposures medical emergency plans should be prepared. Occupational medical examination programs, vaccinations and counseling of employees must be adapted to the outcome of the risk assessment.

Biological Products↗
PubMed2001

The effect of different oil spill remediation techniques on petroleum hydrocarbon elimination in Australian bass (Macquaria novemaculeata).

Petroleum hydrocarbons were investigated in juvenile Australian bass, Macquaria novemaculeata, following exposure to the water accommodated fraction (WAF) of Bass Strait crude oil, chemically dispersed crude oil, and burnt crude oil. Each treatment was administered for 16 days either through the water column or through the diet (amphipod, Allorchestes compressa). Polycyclic aromatic hydrocarbon (PAH) elimination was determined by measuring biliary benzo(a)pyrene (B(a)P) and naphthalene-type metabolites. Biliary PAH-type metabolite concentrations varied with the type of oil spill remediation technique, route of exposure (food versus water), and exposure concentration. Fish exposed to chemically dispersed crude oil via the water exhibited the highest PAH-type biliary metabolite concentrations, relative to fish exposed to other treatments. In fish exposed via the diet, the highest concentration of both types of biliary metabolites also appeared in the dispersed oil-exposed individuals. The results suggest that chemically dispersing oil may have the greatest effect on bioavailability of hydrocarbons, both through waterborne and food chain exposures.

Animals↗
PubMed1998

Safety analysis of contained low-hazard biotechnology applications.

A technical safety analysis has been performed on a containment-level-2 pilot plant in order to assess an upgrading of the existing facility, which should comply with good manufacturing practices. The results were obtained by employing the hazard and operability (HAZOP) assessment method and are discussed in the light of the appropriateness of this procedural tool for low-hazard biotechnology applications. The potential release of micro-organisms accounts only for a minor part of the hazardous consequences. However, in certain cases the release of a large or moderate amount of micro-organisms would not be immediately identified. Most of the actions required to avoid these consequences fall into the realm of operational procedures. As a major part of potential failures result from human errors, standard operating procedures play a prominent role when establishing the concept of safety management. The HAZOP assessment method was found to be adequate for the type of process under investigation. The results also may be used for the generation of checklists which, in most cases, are sufficient for routine safety assurance.

Animals↗
PubMed1999

Containment of a genetically engineered microorganism during a field bioremediation application.

A field release of a genetically engineered microorganism was performed at the Field Lysimeter Site on the Oak Ridge Reservation. Six large lysimeters were filled with soil that had been contaminated with a mixture of naphthalene, phenanthrene, and anthracene. A genetically engineered bacterial strain, Pseudomonas fluorescens HK44, was sprayed onto the surface of the soil during soil loading. This strain contains a fusion between the lux genes of Vibrio fischeri and the promoter for the lower pathway of naphthalene degradation, enabling the strain to become bioluminescent when it is degrading naphthalene. Release of the bacteria outside the lysimeters was monitored, using selective agar plates and one-stage Anderson air samplers. Although approximately 10(14) bacteria were sprayed during the loading process, escape was only detected sporadically; the highest incidence of bacterial escape was found when the relative humidity and wind speed were low.

Air Microbiology↗
PubMed2006

Bisexual sterility conferred by the differential expression of barnase and barstar: a simple and efficient method of transgene containment.

To establish a simple and an efficient system to minimize the environmental risk of genetically modified plants, we tested the applicability of the barnase/barstar system in conferring bisexual sterility; that is, in preventing plants setting seeds by self-fertilization and out-crossing. Transgenic tobacco plants were generated to express barnase, a cell death inducing ribonuclease, under the control of the gamete-specific AtDMC1 promoter, and barstar, a specific inhibitor of barnase, under the control of the ACT2 promoter, which is constitutively active in almost all tissues except gametes. In contrast to control plants harboring the barstar expression unit only, which set seeds normally with self-pollination, all transformants harboring both barnase and barstar were bisexually sterile. They produced aberrant anthers containing no detectable pollen and failed to set seeds even after pollination with wild-type tobacco pollen.

Arabidopsis↗
PubMed2002

Protection from epistaxis blood aerosol contamination: a novel use of a surgical facemask.

Epistaxis is one of the most common otorhinolaryngological emergencies. It is also one of the most common emergencies that places medical staff at risk of blood contamination. We report a simple yet extremely effective method in which a standard surgical facemask is worn by the patient, thereby reducing blood aerosol contamination without interfering with effective management.

Aerosols↗
PubMed1992

Developing a workable infection control policy for the dental laboratory.

An enforced infection control policy in a laboratory will reduce occupational exposure to blood-borne pathogens and other infectious diseases and protect the dental laboratory personnel from exposure to infective disease. An outline of a workable laboratory infection control policy based on "Occupational Exposure to Bloodborne Pathogens" requirements is presented.

Containment of Biohazards↗
PubMed1991

Two cases of intestinal obstruction caused by tuberculosis--the role of frozen section diagnosis.

Upper intestinal obstruction caused by tuberculosis is relatively rare, and the diagnosis is often missed. Two cases are described that were diagnosed by frozen section during laparotomy. It might be thought that endoscopy would have eliminated these difficulties, but this is not in fact the case. Many laboratory safety codes forbid the use of frozen sections on tuberculous material, but in endemic areas this restriction is not practical. Special facilities are required so that all frozen sections can be handled safely.

Adult↗
PubMed1992

Agroinfection of transgenic plants leads to viable cauliflower mosaic virus by intermolecular recombination.

Intermolecular reconstitution of a plant virus has been detected in whole plants in a system using a defective cauliflower mosaic virus genome and transgenic host plants containing the missing viral gene. The information for the gene VI protein of the virus was integrated into the chromosome of host Brassica napus plants and leaves of these plants were inoculated with Agrobacterium tumefaciens containing the complementing viral sequences. In several cases, upper leaves contained replicating viral DNA which was able to incite CaMV symptoms on turnip plants. The sequence of the resultant recombinant viral molecules suggested that both DNA and RNA recombination events may have been involved in the production of functional virus, one event being gene targeting of the T-DNA.

Containment of Biohazards↗
PubMed1992

Space habitat contaminant growth models.

This paper outlines the need for and role of Contaminant Growth Models (CGM) in designing space habitats and space mission operations. The tremendous complexity of the contamination problem and the current lack of data suggests that a "layered" approach to CGM development and utilization be made in conjunction with medical/toxicological research and risk assessments. Two space habitat contaminant examples: thermodegradation and hydrazine, are utilized to show how such a model might be useful in analyzing the environment of a space habitat. The examples also depict how NASA's interdisciplinary Center for Space Environmental Health (CSEH) will combine medical/toxicological research results with engineering environmental system design tools to set standards and help in the design, prediction, monitoring and safe control of space habitats. Since the CSEH project is just beginning, the contents of the paper are descriptive of the goal and the approach being taken, rather than conclusive in nature.

Ammonia↗