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PubMed2003

University of Wyoming, College of Engineering, undergraduate design projects to aid Wyoming persons with disabilities.

In Spring 2002 the University of Wyoming received NSF funding from the Division of Bioengineering and Environmental Systems to provide a meaningful design experience for University of Wyoming, College of Engineering students that will directly aid individuals with disabilities within the state of Wyoming. Other universities have participated in this very worthwhile program [1, 2, 3]. To achieve the program purpose, the following objectives were established: Provide engineering students multi-disciplinary, meaningful, community service design projects, Provide persons with disabilities assistive devices to empower them to achieve the maximum individual growth and development and afford them the opportunity to participate in all aspects of life as they choose, Provide engineering students education and awareness on the special needs and challenges of persons with disabilities, and Provide undergraduate engineering students exposure to the biomedical field of engineering. To accomplish these objectives the College of Engineering partnered with three organizations that provide education and service related to disability. Specifically, the college has joined with the Wyoming Institute for Disabilities (WIND) assistive technology program, Wyoming New Options in Technology (WYNOT) and their Sports and Outdoor Assistive Recreation (SOAR) project along with the university's Special Education program. In this paper we will describe how the program was created, developed, and its current status.

Biomedical Engineering↗
PubMedDate not supplied

[The experience of the EPM (Ergonomics of Posture and Movement) Research Unit in risk analysis and the prevention of work-related musculo-skeletal diseases (WMSDs)].

The twenty-year experience of the "Ergonomics of Posture and Movement (epm)" Research Unit for prevention of work-related musculoskeletal disorders (WMSDs) is briefly summarized. The epm research unit is the outcome of an agreement between Milan University (Clinica del Lavoro Luigi Devoto), Milan Polytechnic, Don Gnocchi Foundation IRCCS (Bioengineering Centre) and the Regional Health Service (CEMOC of ICP Hospital). Early activities of epm (1985-1993) are first outlined: they are characterized by a wide range of laboratory studies allowing the development of original methods and criteria for on-site analysis of fixed postures and awkward movements and for ad hoc clinical examination of the musculoskeletal apparatus in working populations. Epm contributions are reviewed for the analysis of working activity involving manual load handling (adapted NIOSH method) and hospital patients (MAPO method) as well as for standardization of health surveillance protocols of spinal diseases. Updated contributions are reported on analysis and prevention of upper limb MSDs connected with upper limb repetitive movements (OCRA method). Finally epm's main collaborations with national and international Authorities are summarized as well as the major technical (health promotion) publications addressed to operators and workers, in different working situations, for prevention of musculoskeletal disorders due to biomechanical overload.

Ambulatory Care Facilities↗
PubMed2003

A biomechanical study in cadavers of cast boots used in the early postoperative period after first metatarsophalangeal joint arthrodesis.

OBJECTIVES: To compare the effectiveness of 3 common models of walking boots (Walkabout, Samson Walker and Equalizer Premium Walker) to that of a fibreglass cast in protecting an arthrodesis of the first metatarsophalangeal (MTP) joint in the early postoperative period, we carried out a biomechanical study in cadavers in the bioengineering laboratory at Memorial University of Newfoundland. METHODS: Two cadaver models of a first MTP joint arthrodesis were prepared by placing a strain gauge at the joint. This provided a measure of the bending moment across the fusion site. Walking was simulated by applying a force to the sole of the cadaver foot at multiple positions from heel to toe, representing the stages of gait from heel strike to toe off. RESULTS: For both cadaver specimens, the Walkabout boot had the lowest mean moment. The Walkabout and Sampson Walker boots were better than the Equalizer Premium Walker boot and the fibreglass cast (p < 0.05), but the Walkabout boot was the best (p < 0.05). Also, for both specimens, the Walkabout boot had the smallest absolute maximum moment (p < 0.05). CONCLUSION: On a first MTP joint arthrodesis site, removable cast boots provide the same, if not more, reduction of force as a traditional cast.

Arthrodesis↗
PubMed2003

Biomedical informatics: precious scientific resource and public policy dilemma.

Biomedical informatics includes the application of computers, information networks and systems, and a growing body of scientific understanding to a range of problems. As skill in this field increases and as progress in virtually all modern biomedical science becomes more data intensive, informatics becomes a precious resource. Applications areas include access to knowledge, discovery in genomics, medical records, mathematical modeling, and bioengineering. At the same time, progress in informatics is deeply dependent on resolution of four major public policy issues: digital intellectual property rights, genetic testing protection, medical data privacy, and the role of biomedical data in the context of information warfare and homeland security.

Anatomy, Cross-Sectional↗
PubMed2003

Tribological behavior of artificial hip joint under the effects of magnetic field in dry and lubricated sliding.

In recent years, there is an increasing utilization and demand to use magnetic fields in bioengineering applications due to its beneficial effects. Although in the last decade more attention has been given by tribologists to the electromagnetic processes taking place between sliding surfaces, which influence the tribological behaviors, but no attention has been concern with the sliding surfaces of the artificial implant joints. Therefore, the present work aims to elucidate the tribological behavior of an artificial joint implant under the effect of magnetic fields. Experimental investigation was carried out on a specially designed and constructed hip simulator on which the variations in the coefficients of friction and wear rates of the sliding surfaces were evaluated under the influence of a medium strength magnetic field suitable to apply in the human body. A realistic Ti-alloy implanted stem was used with an inserted head made from surgical grade stainless steel. This head was allowed to rub against UHMWPE sockets. The utilized type of prosthesis was "The JRI Modular Muller Standard-Total Hip Design". The performed experimental tests were conducted under both dry and lubricated sliding conditions using physiological saline solution. The designed simulator allows the coefficients of friction and the wear rates to be evaluated under realistic physiological loading and motion cycles encountered during normal walking of the human body. Comparative results are presented between the artificial joint performance in the presence and absence of the applied magnetic field. The experimental results have indicated that the presence of a medium strength magnetic field of 270 Gauss strength between rubbing surfaces resulted in high beneficial reductions in friction and wear rate of UHMWPE sliding on stainless steel either under dry or saline lubricating conditions. Therefore recommendation was forward to subject artificial implants made of stainless steel/UHMWPE combination of material to such medium strength magnetic field in animal clinical trials aiming to prolong the implant life. Scanning investigation of rubbing surfaces has revealed that the transfer of polymer to the counterface plays a dominant role in dictating the frictional and wear behaviors under dry sliding condition. Smooth molecular profile of the polymer-transferred leads to progressive reductions in friction and wear while the lumpy polymer transfer, formed at the beginning of sliding, increases both friction coefficient and wear. Two action mechanisms dominate the sliding process; adhesive and abrasive mechanisms. The presence of saline lubricant retards the formation of the beneficial polymer transfer thus leading to faster abrasion of the polymeric counterface which explains the relatively rapid and progressive increases in friction and wear.

Biocompatible Materials↗
PubMed1992

Clinical prosthodontic management of a new implant system.

Just prior to the advent of the branemark implant, the Harvard consensus on implantology condemned all maxillary implants. While implant utilization has skyrocketed in the last few years integration of implants in the maxilla is a persistent problem and even the branemark implant enjoys a lower success rate in this bone. These observations underscore the higher failure rate of the maxillary implant and suggest the need for development of a new implant design configuration that would favour long term successful integration despite the attenuated maxillary attributes. Such is the intent of the ostial implant. The basic considerations concerning this device, its bioengineering, experimental performance and clinical trials are discussed elsewhere. The purpose of this paper is to describe clinical prosthodontic applications of this implant system.

Dental Implants↗
PubMed1992

Controlled ecological life-support system. Use of plants for human life-support in space.

Scientists and engineers within NASA are conducting research which will lead to development of advanced life-support systems that utilize higher plants in a unique approach to solving long-term life-support problems in space. This biological solution to life-support, Controlled Ecological Life-Support System (CELSS), is a complex, extensively controlled, bioengineered system that relies on plants to provide the principal elements from gas exchange and food production to potable water reclamation. Research at John F. Kennedy Space Center (KSC) is proceeding with a comprehensive investigation of the individual parts of the CELSS system at a one-person scale in an approach called the Breadboard Project. Concurrently a relatively new NASA sponsored research effort is investigating plant growth and metabolism in microgravity, innovative hydroponic nutrient delivery systems, and use of highly efficient light emitting diodes for artificial plant illumination.

Aerospace Medicine↗
PubMed2003

[Design of an impedance plethysmograph for reactive hyperemia evaluation in the forearm].

Impedance pletismography is based on the evaluation of the voltage change that occur as a consequence of blood flow variations in a particular tissue section. Current applied for the procedure should be alternating, weak and of high frequency to avoid electrically excitable cells stimulation, such as muscles and nerves. Blood volume changes can be measured by this method and has been applied in the diagnosis of deep venous thrombosis of limbs. An impedance meter was designed and built to be used in the forearm of patients. It consists of a voltage stabilizer TPS 76150 with simultaneous ECG recording (DII lead). Injected signal had 50 KHz (Wien's bridge) and registered through two operational amplifiers LM 3080 (1 mA). Signal was demodulated and amplified. Electrodes used were made of silver strips with conductance improved by conductivity gel, fixed by elastic rubber strips. Circuit wiring and equisition software was developed at the Bioengineering Department of Simón Bolívar University. Fifteen healthy subjects, age range 18-30 years old, were submitted to noninvasive forearm blood flow evaluation with the already described electronic device. Brachial artery occlusions were made with a cuff at subdiastolic, supradiastolic and suprasystolic blood pressures, for 60 and 90 seconds and then this occlusion was abruptly released. The curve was displayed and recorded in a portable PC (laptop). During suprasystolic occlusion the impedance observed curve showed a progressive increased until stabilization. When occlusion was released a sudden peak appeared which corresponds to reactive hyperemia of the forearm. This peak has been associated to the secretion of endothelial vasodilatory substances. In conclusion, this device is suitable to be used in clinical settings for the evaluation of reactive hyperemia and potentially useful in diagnosis of deep veins occlusions.

Adult↗
PubMed2003

Analysis of parental strain DNA fragments existing in GEMs-Fhhh.

There were 6 target DNA fragments of the three parental strains existing in the cell of GEMs (genetically engineered microorganism strain) Fhhh measured in this research by PCR(polymerase chain reaction). The determination showed that GEMs Fhhh contained all the 6 target DNA fragments, mnp1, mnp2, lip1, lip2, FLO1 and 16S rDNA, and had the molecular genetic stability. Meanwhile the PCR production of each parental strain could only had its target DNA fragments and was different from each other. It may illustrate that the technique of the inter-kingdom protoplast fusion for the construction of GEMs Fhhh through the process of intercellular gene recombination could be used as a reliable bioengineering technique to create the specific functional stain for the pollution control.

Bacteria↗
PubMed2003

[Vacuum--a novel method for treating chronic wounds].

Chronic wounds represent a major health burden and drain on resources. In spite of advances in our understanding of chronic wound biology and the development of new treatments, there is no one form of treatment suitable for all wounds and patients. Many factors can impair healing--local and systemic. The current treatments include different ways of debridement, occlusive hydrocolloid dressings, topical growth factors, hyperbaric oxygen, bioengineered skin equivalents and more. In the last decade there is an increment in the use of negative pressure dressing (VAC--vacuum assisted closure system) in the treatment of chronic wounds from different etiologies--diabetic, venous and pressure sores. Our experience demonstrated good results in the treatment of diabetic and venous insufficiency ulcers, and disappointing results in the treatment of pressure sores. Promising results were demonstrated in the treatment of acute injuries, lowering the need for microvascular reconstruction. Prospective researches examining the efficacy and cost effectiveness of this treatment in comparison to other methods are crucial for wise and extensive use of the VAC system.

Humans↗
PubMed2004

Changing trends in valve surgery in Europe: 1991-2000.

BACKGROUND AND AIM OF THE STUDY: This study sought to elaborate the changing trends in valve surgery in Europe during the 1990s. METHODS: The databases of different national surgical societies, registries and governments and international organizations were consulted and the data obtained were analyzed. RESULTS: The population of Europe (excluding Russia, CIS and Turkey) increased by 2.29%, from 509.67 million in 1991 to 519.15 million in 2000. During this period, the volume of cardiac surgery increased in Europe by 101% to 413,520 operations (797 per 10(6) population). The volume of valve surgery increased by 63% to 85,076 (164 per 10(6) population). The largest volumes of valve surgery were performed in Germany, France, UK, Italy and Spain. The increase in valve surgery volume was maximum in the Baltic states (+287%) and least in Scandinavia (+30%). Valve surgery volume per center per year changed from 139 in 1991 to 140 in 2000. The increase in overall valve surgery volume was sustained by an increase in subsets of octogenarian patients, valve surgery combined with coronary artery surgery, and increased productivity of the emerging economies of countries such as the Czech Republic, Hungary and Poland. Valve surgery as a proportion of cardiac surgery in Europe changed from 25.95% in 1991 to 21% in 2000. In 2000, valve surgery with combined procedures constituted 6.7% of total cardiac surgical volume, but 32% of valve surgical output in Europe. Mechanical valves have continued to dominate and were used in 77% of cases in 2000. Increased use of bioprostheses in the elderly subset among affluent economies was balanced by an increased use of mechanical prostheses in younger patients in emerging facilities in the East and South. The capital-intensive innovations (viz. robotic valve surgery, minimally invasive valve surgery, bioengineered valves) found niches only in some West European centers. Catheter-based procedures did not fulfil their promise. Balloon aortic valve dilatation investigations decreased drastically by the end of the decade, and balloon mitral dilatations number. Conservative aortic valve surgery is not yet practiced widely across Europe, while mitral repair has become widely accepted in clinical parlance. CONCLUSION: Despite the greater political and economic integration of Europe, the pattern of valve surgery continues to remain extremely diverse within the continent.

Aged↗
PubMed2004

Chronic obstructive lung disease: from structure to pathology.

Chronic obstructive pulmonary disease (COPD) is a complex disease characterized by progressive and irreversible airway obstruction and ubiquitous chronic inflammation in the lung. It is the end result of accumulated damage to many parts of the lung by many types of noxious agents, a destructive exhaustion of the lung reserve. Recent increases in the incidence of COPD have occurred mainly in older age groups, in non-smokers, and in females. Pathologically, COPD is characterized by chronic inflammation which perpetuates and accumulates locally. Discrete areas interact with each other, in the locus resistentia minoris (LRM), the sites of weak resistance of the lung, suggesting that insidious destruction with exhaustion of pulmonary reserves is still the main culprit of COPD. Traditional treatments of COPD are useful in symptomatic control but do not prevent progression of the disease. Prevention is still the best way to manage COPD. New pharmaceutical agents and bioengineered products using molecular or genetic techniques to block inflammatory mediators or their receptors may contain the inflammatory and noxious agents in the LRM and prevent their propagation. Methodologies involving structural approaches, such as devices to estimate the status of airways and associated vessels and the remaining lung reserve, creation of collateral or bypass ventilation pathways, and reduction of volume of over-inflated areas may be effective. The balance between exposure and clearance, injury and repair, ultimately decides how quickly the great reserves of the lung are depleted.

Humans↗
PubMedDate not supplied

Transgenic foods as a tool for malnutrition elimination and their impact on agricultural systems.

GMO crops were introduced for commercial production in 1996. Since then, their use has increased rapidly. GMOs have primarily benefited large farms and multinational companies in Industrialised Countries and now is more and more debating their utilisation in Developing World. The objective of the present review is an analysis of this subject from a comprehensive point of view; in addition to that, the changes related to the nutritional content of transgenic foods will be treated. Despite the progress that has been made, the world food situation is still marked by mass hunger and chronic malnutrition. In particular micronutrient malnutrition, that means vitamin and mineral deficiencies, represents an important public health problem in several areas of the world. The "golden rice" bioengineered to contain beta-carotene, as a source of vitamin A is the most famous example of GM food used for reduction (or even to solve) of a public health problem. The expected results of this approach have presently not been achieved. Further studies are necessary to increase the general knowledge about GMOs and their long-term effects on human health. Collaborative attitude of different research sectors (private and public) and involvement of different sectors of society will be an added value for comprehension of the real impact of the application of modern biotechnology to food and agriculture systems.

Agriculture↗
PubMedDate not supplied

[Intestinal autoflora of the test subjects in a 6-month biological engineering experiment].

During a 6-month bioengineering experiment the intestinal microflora of four test subjects was examined. Changes in the composition of different groups of intestinal microflora (bifidobacteria, lactic-acid bacteria, sporogenous anaerobes, proteus, etc) were found. In spite of the unstable pattern of the intestinal microflora and its tendency for simplification, the total number of microorganisms in 1 g of feces remained relatively unchanged in all the test subjects.

Biomedical Engineering↗
PubMed2004

[A pilot study on transdifferentiation of skin stem cell in reconstructing corneal epithelium].

OBJECTIVE: To observe the differentiation and development of skin stem cells on corneal stroma and to discuss the possibility of reconstructing corneal epithelium with skin stem cells. METHODS: Pieces of human and rabbit skin were obtained during operation. Rabbit eye balls were taken, and pieces of corneal stroma without epithelium were prepared. Skin stem cells from the rabbit skin and human skin were cultured. The human skin stem cells of the first generation to 4th generation were implanted on the rabbit corneal stroma and cultured. Three rabbits underwent autotransplantation of the rabbit skin stem cells of the first generation to 4th generation on the pieces of corneal stroma with the superficial lamina removed and then fed for 100 approximately 114 days. Another 3 rabbits underwent allotransplantation of the rabbit skin stem cells of first to 4th generation on the pieces of corneal stroma with the superficial lamina removed and then fed for 100 days. Then the rabbits were killed and their eye balls taken out. The rabbit corneas implanted with human or rabbit epithelial cells and the rabbit corneas with the autogeneous or heterogeneous epithelial cells were sliced and underwent immunohistochemistry with human AE5 antibody corresponding to the specific surface marker keratin K3/K12 common to humankind and rabbit, and human epithelial cell keratin K-19 monoclonal antibody. RESULTS: Since the 3(rd) day of transplantation the transplanted human epithelial cells formed multiplayer and were human AE5 antibody and human K19 monoclonal antibody positive. The autotransplanted corneas remained basically transparent without obvious vascular hyperplasia till the cornea specimens were taken. Histological examination showed intact multiplayer epithelium and immunohistochemistry showed human AE5 positive. The allotransplanted\rabbit corneas showed congestion since the 9(th) day. Histological examination showed that the corneas were nor so transparent as the autotransplanted ones and the epithelium was nor intact with a lot of lymphocyte infiltration. CONCLUSION: Corneal epithelium can be reconstructed from skin stem cell, which may be an alternative for constructing autogeneous bioengineered corneas.

Animals↗
PubMed2004

Revision total elbow arthroplasty with impaction allografting and uncemented partially hydroxyapatite-coated custom-made prostheses.

Total elbow arthroplasty has become a relatively common procedure in the last decade, and the number of primary total elbow replacements performed is likely to continue to increase as the population ages. The incidence of technically demanding prosthesis revisions involving complex problems such as major bone loss is therefore expected to increase. We report 3 cases of total elbow revision arthroplasty, all of which represented patients with severe bone loss. They were all treated using the impaction allografting technique and uncemented custom-made semiconstrained prostheses partially coated with hydroxyapatite manufactured at the bioengineering department of our institution.

Aged↗
PubMed2004

Development and testing of a novel biosynthesized XCell for treating chronic wounds.

Biosynthesized cellulose is produced by the bacteria, Acetobacter xylinum, and possesses unique properties not present in other biomaterials. The material is formed during fermentation having a multi-layered structure composed of fine, nonwoven, cellulose hydrophilic fibers. This structure allows biosynthesized cellulose to have a high-fluid capacity, superior strength, and biocompatibility, which makes it suitable for topical and implantable biomedical applications. Initial product development of biosynthesized cellulose has focused on advanced wound-care applications. The product, XCell (Xylos Corporation, Langhorne, PA, USA), has been bioengineered to have the ability to both donate and absorb moisture, depending on the wound environment. Comparative bench testing has shown that XCell is the only wound dressing with this unique dual-fluid-handling capability. The product has been studied thoroughly using animal models and proved to be safe and biocompatible. Human clinical testing has demonstrated its effectiveness in providing a moist environment, essential to treating hard-to-heal chronic wounds. The major clinical benefits of the product include: 1) help in removal of non-viable tissue and promotion of autolytic debridement, which results in increased granulation tissue; 2) cleansing of wound margins that leads to epithelial migration and reduction of wound size; and 3) healing of various types of chronic wounds.

Bandages, Hydrocolloid↗
PubMed2004

Fetal cell/tissue therapy in adult disease: a new horizon in regenerative medicine.

Fetal tissue is the richest source of primordial stem cells and has several properties that make it particularly useful for transplantation. It is superior to adult (mature) tissue in certain respects. First, fetal cells are capable of proliferating faster and more often than mature, fully differentiated cells. This means that these donor cells are able to quickly reverse the lost function of the host. In addition, these fetal cells can often differentiate in response to the environmental cues around them. This is because of their location--they can grow, elongate, migrate, and establish functional connections with other cells around them in the host. It has been found that fetal tissue is not easily rejected by the recipient due to the low levels of histocompatibility antigens in the fetal tissue. At the same time, angiogenic and trophic factors are at high levels, enhancing their ability to grow once they are transplanted. Since early fetal hematopoietic tissue lacks lymphocytes, graft vs host reactions are minimized. Fetal cells tend to survive excision, dissection, and grafting better because they generally do not have long extensions or strong intercellular connections. Finally, fetal tissue can survive at lower oxygen levels than mature cells. This would make them more resistant to the ischemic conditions found during transplantation or in vitro situations. Studies on fetal cell/tissue transplant have been encouraging. Fetal tissue can be used in different indications, for instance, fetal liver transplants may be used in combating aplastic anemia, placental umbilical cord whole blood transfusion can serve as an emergency alternative to adult whole blood transfusion, fetal adrenal transplant has been tried in combating intractable pain in arthritis, and fetal thymic transplant in combating leucopenia in non-Hodgkin's lymhoma and other immunodeficiency conditions like DiGeorge Syndrome, only to name a few. Fetal brain tissue transplant has also been done in a heterotopic site and the proliferation of the tissue has been observed. Neurotransplantation with fetal tissue in Parkinsonism shows positive results in some globally accepted studies. There are futuristic potential uses of fetal tissue in bioengineering through coating/seedling of fetal tissue on implants, stents and other artificial surgical life-saving devices to improve their functioning, and it may also extend the life of these costly gadgets. By properly using pre-HLA fetal tissue seedling in orthopedic, thoracic and also neurosurgical appliances, there could be a reduction of long-term irritation sequelae of the implant and the host interphase, and thus, a better device, i.e., a more biofriendly interphase could be developed. This may help in the reduction of pseudomembrane formation, loss of patency and other resultant TH2 reactions of the host system.

Biocompatible Materials↗