Sanitary Engineering
Tissue Engineering
Protein Engineering
Genetic Engineering
Metabolic Engineering
Biomedical Engineering
Role of biofilms in the survival of Legionella pneumophila in a model potable-water system. (1/79)
Legionellae can infect and multiply intracellularly in both human phagocytic cells and protozoa. Growth of legionellae in the absence of protozoa has been documented only on complex laboratory media. The hypothesis upon which this study was based was that biofilm matrices, known to provide a habitat and a gradient of nutrients, might allow the survival and multiplication of legionellae outside a host cell. This study determined whether Legionella pneumophila can colonize and grow in biofilms with and without an association with Hartmannella vermiformis. The laboratory model used a rotating disc reactor at a retention time of 6.7 h to grow biofilms on stainless steel coupons. The biofilm was composed of Pseudomonas aeruginosa, Klebsiella pneumoniae and a Flavobacterium sp. The levels of L. pneumophila cells present in the biofilm were monitored for 15 d, with and without the presence of H. vermiformis, and it was found that, although unable to replicate in the absence of H. vermiformis, L. pneumophila was able to persist. (+info)Urban history, urban health. (2/79)
Over the course of the 20th century, the United States became an urban nation: 80% of Americans now live in metropolitan areas. Supplying basic sanitary services-drinking water, sewers, and garbage removal-to these cities is a gargantuan task, yet most people have little understanding of urban infrastructure systems and their enormous regional ecologic impacts. Municipalization of sanitary services, especially since 1880, distanced people from their wastes and gave city dwellers a simplistic experience of one-way material flow through cities, without knowledge of the environmental costs. Most sanitary infrastructures were built primarily for durability and lack the elasticity to meet changing needs. The challenge now is to adapt sanitary systems for flexibility and simultaneously move from unchecked material consumption toward resource-based thinking. (+info)Barriers to safe hot tap water: results from a national study of New Zealand plumbers. (3/79)
INTRODUCTION: Many countries still have unacceptably high hospitalizations and deaths from scalds from hot tap water. Prevention strategies implemented in some countries may not work in others. Legislation aimed at changing environments that are conducive to hot tap water scalds may not be effective in many situations for a number of reasons, including lack of acceptability and practicality. METHOD: A qualitative study of a purposefully selected group of craftsman plumbers across New Zealand was conducted using a structured format with open ended questions. The questionnaire was administered by telephone. Information was sought on the opinions, knowledge, and practice of these plumbers regarding hot tap water safety in homes. RESULTS: Several barriers to hot tap water safety in homes were identified by the plumbers. These included common characteristics of homes with unsafe hot tap water, such as hot water systems heated by solid fuel, and public ignorance of hot tap water safety. Other factors that emerged from the analysis included a lack of knowledge by plumbers of the hazards of hot tap water, as well as a lack of importance given to hot tap water safety in their plumbing practice. Shower performance and the threat to health posed by legionella were prioritized over the prevention of hot tap water scalds. CONCLUSION: The findings of this study allow an understanding of the practical barriers to safe hot tap water and the context in which interventions have been applied, often unsuccessfully. This study suggests that plumbers can represent a barrier if they lack knowledge, skills, or commitment to hot tap water safety. Conversely, they represent a potential source of advocacy and practical expertise if well informed, skilled, and committed to hot tap water safety. (+info)Screening test for assessment of ultimate biodegradability: linear alkylbenzene sulfonates. (4/79)
A relatively simple shake-flask system for determining CO2 evolution was developed to assess the ultimate biodegradability by soil and sewage micro-organisms of chemicals which enter the environment. Linear alkylbenzene sulfonates (LAS) were used as model compounds to evaluate the method and were found to undergo substantial biodegradation in this dilute system. At the 30 mg/liter test concentration, higher-molecular-weight LAS compounds were biodegraded at a slower rate and to a lesser extent than lower-molecular-weight LAS, an effect which was eliminated or greatly reduced upon incremental addition of the LAS to the test medium during the first week of incubation. LA35S was used to demonstrate rapid LAS desulfonation, and 14CO2 evolution studies with (14C) benzene ring-labeled LAS indicated concomitant biodegradation of the entire LAS molecule as well as the LAS aromatic component. The test can be employed to examine numerous compounds at the same time and is readily adapted to studies of the effect of variation in temperature and oxygen concentration on biodegradation. (+info)Identification of bacteria in drinking and purified water during the monitoring of a typical water purification system. (5/79)
BACKGROUND: A typical purification system that provides purified water which meets ionic and organic chemical standards, must be protected from microbial proliferation to minimize cross-contamination for use in cleaning and preparations in pharmaceutical industries and in health environments. METHODOLOGY: Samples of water were taken directly from the public distribution water tank at twelve different stages of a typical purification system were analyzed for the identification of isolated bacteria. Two miniature kits were used: (i) identification system (api 20 NE, Bio-Merieux) for non-enteric and non-fermenting gram-negative rods; and (ii) identification system (BBL crystal, Becton and Dickson) for enteric and non-fermenting gram-negative rods. The efficiency of the chemical sanitizers used in the stages of the system, over the isolated and identified bacteria in the sampling water, was evaluated by the minimum inhibitory concentration (MIC) method. RESULTS: The 78 isolated colonies were identified as the following bacteria genera: Pseudomonas, Flavobacterium and Acinetobacter. According to the miniature kits used in the identification, there was a prevalence of isolation of P. aeruginosa 32.05%, P. picketti (Ralstonia picketti) 23.08%, P. vesiculares 12.82%,P. diminuta 11.54%, F. aureum 6.42%, P. fluorescens 5.13%, A. lwoffi 2.56%, P. putida 2.56%, P. alcaligenes 1.28%, P. paucimobilis 1.28%, and F. multivorum 1.28%. CONCLUSIONS: We found that research was required for the identification of gram-negative non-fermenting bacteria, which were isolated from drinking water and water purification systems, since Pseudomonas genera represents opportunistic pathogens which disperse and adhere easily to surfaces, forming a biofilm which interferes with the cleaning and disinfection procedures in hospital and industrial environments. (+info)Acute health effects after accidental exposure to styrene from drinking water in Spain. (6/79)
OBJECTIVES: We studied subjective health symptoms in a population accidentally exposed to high styrene concentrations in drinking tap water. The contamination occurred during the reparation of a water tank. METHODS: Residents of 27 apartments in two buildings using the contaminated water were contacted. A questionnaire on subjective symptoms was administered to 84 out of 93 persons living in the apartments at the time of the accident. Styrene concentration was measured in samples of water collected two days after the accident. The means of exposure associated with appearance of symptoms were examined through case-control analyses. RESULTS: Styrene in water reached concentrations up to 900 microg/L. Symptoms were reported by 46 persons (attack rate 55 %). The most frequent symptoms were irritation of the throat (26%), nose (19%), eyes (18%) and the skin (14%). General gastrointestinal symptoms were observed with 11% reporting abdominal pain and 7% diarrhea. The factors most strongly associated with symptoms were drinking tap water (OR = 7.8, 95% CI 1.3-48), exposure to vapors from the basement (OR = 10.4, 2.3-47) and eating foods prepared with tap water (OR = 8.6, 1.9-40). All residents in the ground floor reported symptoms. CONCLUSIONS: This accidental contamination led to very high styrene concentrations in water and was related to a high prevalence of subjective symptoms of the eyes, respiratory tract and skin. Similar exposures have been described in workers but not in subjects exposed at their residence. Various gastrointestinal symptoms were also observed in this population probably due to a local irritative effect. (+info)Alternative approaches in schistosomiasis control. (7/79)
Measures for the control of schistosomiasis were implemented in Egypt beginning 1922. This shows that developing endemic countries are facing this problem for near 70 years. However, results in the control of this infection have not been satisfactorily obtained in spite of the technologies and strategies recently developed. The idea that social and economic components are relevant in the control of schistosomiasis is not new although its extension and profundity have not usually been well understood. More recently, most of the workers have recognized that the focal distribution of the prevalence rates of schistosomiasis should not be neglected in the control of the infection. At present, field work projects on the control of schistosomiasis are being developed in rural areas of two Brazilian studies (Espirito Santo and Pernambuco). The adopted strategy aims to interfere in the complex relationships between man and his bio-social-cultural environment, without forgetting that the unequal distribution of the space is a consequence of the political and economic organization of the Society. (+info)The public health significance of trace chemicals in waste water utilization. (8/79)
The practice of waste water utilization has grown considerably in recent years, owing to the growing demand for water for agricultural, industrial and domestic purposes. Such utilization presents certain problems in respect of the quality of the reclaimed water, on account of the presence of certain trace chemicals in the waste waters to be re-used. The presence of these trace chemicals may have important consequences in the agricultural or industrial utilization of waste waters, but from the public health point of view it is in the re-use of waste waters for domestic purposes that their presence has most importance, owing to their possible toxic effects.This paper discusses the public health significance of trace chemicals in water, with special reference to some of the newer complex synthetic organic compounds that are appearing in ever-increasing numbers in industrial wastes. Current information on the acute and chronic toxicity of these substances is reviewed and related to possible methods of treatment of waste waters.In conclusion, the author points out that the problem of trace chemicals is not confined only to direct waste-water reclamation projects, but arises in all cases where surface waters polluted with industrial wastes are used as a source of domestic supply. (+info)Sanitary engineering is not typically considered a medical definition, but rather it falls under the field of public health and environmental engineering. However, it is closely related to medicine and public health due to its focus on preventing disease transmission through the design and construction of safe water supplies, sanitary sewage disposal systems, and solid waste management facilities.
Here's a definition of sanitary engineering from the American Public Health Association (APHA):
"Sanitary engineering is the application of engineering principles to public health problems involving the control of environmental factors that affect human health. It includes the design, construction, and maintenance of systems for the collection, treatment, and disposal of wastewater and solid waste; the protection of water supplies from contamination; and the control of vectors of disease through the management of public facilities and environments."
In summary, sanitary engineering involves the application of engineering principles to prevent the spread of diseases by ensuring safe and adequate water supplies, proper sewage disposal, and effective solid waste management.
Tissue engineering is a branch of biomedical engineering that combines the principles of engineering, materials science, and biological sciences to develop functional substitutes for damaged or diseased tissues and organs. It involves the creation of living, three-dimensional structures that can restore, maintain, or improve tissue function. This is typically accomplished through the use of cells, scaffolds (biodegradable matrices), and biologically active molecules. The goal of tissue engineering is to develop biological substitutes that can ultimately restore normal function and structure in damaged tissues or organs.
Protein engineering is a branch of molecular biology that involves the modification of proteins to achieve desired changes in their structure and function. This can be accomplished through various techniques, including site-directed mutagenesis, gene shuffling, directed evolution, and rational design. The goal of protein engineering may be to improve the stability, activity, specificity, or other properties of a protein for therapeutic, diagnostic, industrial, or research purposes. It is an interdisciplinary field that combines knowledge from genetics, biochemistry, structural biology, and computational modeling.
Genetic engineering, also known as genetic modification, is a scientific process where the DNA or genetic material of an organism is manipulated to bring about a change in its characteristics. This is typically done by inserting specific genes into the organism's genome using various molecular biology techniques. These new genes may come from the same species (cisgenesis) or a different species (transgenesis). The goal is to produce a desired trait, such as resistance to pests, improved nutritional content, or increased productivity. It's widely used in research, medicine, and agriculture. However, it's important to note that the use of genetically engineered organisms can raise ethical, environmental, and health concerns.
Metabolic engineering is a branch of biotechnology that involves the modification and manipulation of metabolic pathways in organisms to enhance their production of specific metabolites or to alter their flow of energy and carbon. This field combines principles from genetics, molecular biology, biochemistry, and chemical engineering to design and construct novel metabolic pathways or modify existing ones with the goal of optimizing the production of valuable compounds or improving the properties of organisms for various applications.
Examples of metabolic engineering include the modification of microorganisms to produce biofuels, pharmaceuticals, or industrial chemicals; the enhancement of crop yields and nutritional value in agriculture; and the development of novel bioremediation strategies for environmental pollution control. The ultimate goal of metabolic engineering is to create organisms that can efficiently and sustainably produce valuable products while minimizing waste and reducing the impact on the environment.
Biomedical engineering is a field that combines engineering principles and design concepts with medical and biological sciences to develop solutions to healthcare challenges. It involves the application of engineering methods to analyze, understand, and solve problems in biology and medicine, with the goal of improving human health and well-being. Biomedical engineers may work on a wide range of projects, including developing new medical devices, designing artificial organs, creating diagnostic tools, simulating biological systems, and optimizing healthcare delivery systems. They often collaborate with other professionals such as doctors, nurses, and scientists to develop innovative solutions that meet the needs of patients and healthcare providers.
Tissue scaffolds, also known as bioactive scaffolds or synthetic extracellular matrices, refer to three-dimensional structures that serve as templates for the growth and organization of cells in tissue engineering and regenerative medicine. These scaffolds are designed to mimic the natural extracellular matrix (ECM) found in biological tissues, providing a supportive environment for cell attachment, proliferation, differentiation, and migration.
Tissue scaffolds can be made from various materials, including naturally derived biopolymers (e.g., collagen, alginate, chitosan, hyaluronic acid), synthetic polymers (e.g., polycaprolactone, polylactic acid, poly(lactic-co-glycolic acid)), or a combination of both. The choice of material depends on the specific application and desired properties, such as biocompatibility, biodegradability, mechanical strength, and porosity.
The primary functions of tissue scaffolds include:
1. Cell attachment: Providing surfaces for cells to adhere, spread, and form stable focal adhesions.
2. Mechanical support: Offering a structural framework that maintains the desired shape and mechanical properties of the engineered tissue.
3. Nutrient diffusion: Ensuring adequate transport of nutrients, oxygen, and waste products throughout the scaffold to support cell survival and function.
4. Guided tissue growth: Directing the organization and differentiation of cells through spatial cues and biochemical signals.
5. Biodegradation: Gradually degrading at a rate that matches tissue regeneration, allowing for the replacement of the scaffold with native ECM produced by the cells.
Tissue scaffolds have been used in various applications, such as wound healing, bone and cartilage repair, cardiovascular tissue engineering, and neural tissue regeneration. The design and fabrication of tissue scaffolds are critical aspects of tissue engineering, aiming to create functional substitutes for damaged or diseased tissues and organs.