Biomedical Engineering and Bioengineering Commons^™

Immunocytochemical And Lectin-Gold Characterization Of The Interface Between Alveolar Bone And Implanted Hydroxyapatite In The Rat, H. Kawaguchi, M. D. Mckee, H. Okamoto, A. Nanci

Cells and Materials

The tissue response to implanted hydroxyapatite (HAP) in rat alveolar bone was investigated using morphological and cytochemical approaches. High-resolution immunogold labeling was used to examine the distribution of two non-collagenous bone proteins, osteopontin and osteocalcin, and two plasma proteins, a2HSglycoprotein (fetuin) and albumin. Glycoconjugates were characterized by lectin-gold cytochemistry using Ricinus communis I agglutinin and Wheat germ agglutinin. Transmission electron microscopy demonstrated the presence of an electron-dense, lamina limitans-like layer at the HAP particle-bone interface and organic material within the micropores of the particles. Mineral was observed in relation to both these sites. The HAP particle-bone interface was strongly …

The Peo/Pbt Copolymer-Mineralized Matrix Interface In Vitro, A. M. Radder, J. E. Davies, H. Leenders, C. A. Van Blitterswijk

Cells and Materials

Previous implantation experiments have investigated the interaction between a series of PEO/PBT copolymers (Polyactive®) and bone tissue, and shown the morphology of bone-bonding with several PEO/PBT ratios. However, the underlying mechanism of bone-bonding remains largely unknown. Therefore, an in-vitro approach was chosen to obtain more information on the events occurring at the PEO/PBT copolymer-bone interface. Rat marrow cells were cultured on two PEO/PBT copolymer proportions: a 60/40 ratio which is known to bond with bone tissue in-vivo and a 30170 ratio which, within one year of implantation, does not bond with bone. Evaluation was performed with light microscopy, scanning, backscatter …

Organic Extracellular Matrix Components At The Bone Cell/Substratum Interface, X. Shen, E. Roberts, S. A. F. Peel, J. E. Davies

Cells and Materials

We have recently shown that differentiating bone cells are capable of elaborating, in vitro, a calcified matrix at the interface with several non-biological substrata which is similar to cement lines found in remodelling bone tissue. From previous morphological observations, this matrix appeared free of assembled collagen fibres which indicated that osteogenic cells produce an initial mineralized matrix before overt collagen fibre production. In the work reported herein, we used six antibodies to extracellular matrix components and two conjugates of secondary antibody, fluorescein and colloidal gold, to initiate a preliminary characterization of the organic components at the bone cell substratum …

Attachment Kinetics And Differentiations Of Osteoblasts On Different Biomaterials, U. Meyer, D. H. Szulczewski, K Moller, H. Heide, D. B. Jones

Cells and Materials

Primary bovine osteoblast cell cultures were used to study the response of osteoblasts ton three different biomaterials, ionomeric cement (IC), tri-calcium phosphate poly-L-lactic acid composite foil (TCP) and poly-L-lactate-polycitric acid composite foil (PLA). The cells which grew on the materials produced all typical bone matrix proteins and were osteoblast-Iike as shown by immuno-staining. Analysis of the cell attachment kinetics revealed significant differences within the first 7 hours between the various materials. The best rate of cell attachment was found on the IC surface, followed by the TCP and then the PLA surface. The kinetics of attach ment appeared to be …

The Effect Of Substratum Roughness On Osteoclast-Like Cells In Vitro, K. Gomi, J. D. De Bruijn, M. Ogura, J. E. Davies

Cells and Materials

Calcium phosphate powders were used to produce three groups of experimental substrata for the culture of primary rat bone marrow cells in conditions which permitted the survival and function of osteoclasts. Each of the three experimental groups were subdivided by differences in substratum surface roughness and following a culture period of 7 to 11 days, the culture units were stained for tartrate-resistant acid phosphatase activity. In all samples both small, sometimes mononuclear, and large multinucleate cells stained positive for tartrate-resistant acid phosphatase activity and the numbers and types of cells were quantified and statistically analyzed. Following histochemical staining the samples …

Drying Rate Constants For Yellow Dent Corn As Affected By Fatty Acid Ester Treatments, Curtis L. Weller, J. M. Bunn

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Ethyl oleate and ethyl stearate solutions at various concentrations were used to treat corn samples prior to drying.

Property Modification Of Edible Wheat, Gluten-Based Films, A. Gennadios, Curtis L. Weller, R. F. Testin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Procedures were developed to produce edible wheat, gluten-based films. A film was produced as a standard. Five additional films were then produced by modifying the initial film-forming solution. Modifications included changing the plasticizer, partially substituting wheat gluten with soy protein isolate and corn zein, and incorporating two acetylated monoglyceride products. All films were characterized by measuring selected mechanical properties, and permeabilities to water vapor and to oxygen. Comparison of the films, in terms of their measured properties, indicates ways to improve the overall performance of the standard film as a potential packaging material. A main limitation of all of the …

Relative Humidity And Temperature Effects On Tensile Strength Of Edible Protein And Cellulose Ether Films, A. Gennadios, H. J. Park, Curtis L. Weller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The effect of relative humidity and temperature on tensile strength of two types of protein-based [corn zein (CZ) and wheat gluten (WG)] and two types of cellulosic [methylcellulose (MC) and hydroxypropyl cellulose (HPC)] hydrophilic edible films was investigated.

Modification Of Physical And Barrier Properties Of Edible Wheat Gluten-Based Films, Aristippos Gennadios, Curtis L. Weller, Robert F. Testin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Edible films were produced from wheat gluten-based film-forming solutions. One film was produced as a control. Other types came from subjecting control films to three different soaking treatments. Three additional films were also produced by modifying the control film-forming solution. For all films, selected physical properties and permeability to water vapor and oxygen were measured. Comparisons indicated possible ways to improve the control film. All films were good oxygen barriers but limited water vapor barriers. Films containing hydrolyzed keratin had lower oxygen permeability (83%) and lower water vapor permeability (23%). Films containing mineral oil had lower water vapor permeability (25%). …

Chemical Tracing Techniques For Evaluating Rill Hydraulics, John E. Gilley, Eugene R. Kottwitz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Development of water erοsiοn and surface water quality control practices requires information concerning the hydraulic characteristics of upland areas. The relatively small flow rates normally found within rills make measurement of hydraulic parameters difficult. Chemical tracing procedures, originally developed for stream and river systems, have been successfully used to measure rill flow properties. A chemical tracer of known concentration is added to the rill and by knowing the degree of dilutiοn at a downstream sampling point, flow rate can be calculated. Rill flow velocity can be measured by determining the time required for a slug of tracer material to travel …

Interposed Abdominal Compression Cardiopulmonary Resuscitation: Are We Missing The Mark In Clinical Trials?, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Straightforward considerations of abdominal anatomy in human beings set tight constraints on the theoretically optimal technique for abdominal compressions during interposed abdominal compression (IAC)-CPR. The location and extent of the abdominal aorta lead naturally to the recommendation that IAC be applied at a level corresponding to the lower two thirds of the sterno-umbilical line. The force vector required to achieve contact compression of the abdominal aorta is inclined in the transverse plane at an angle of 11 degrees from the vertical toward the left. Such slightly angled compression subjects the abdominal aorta to maximally flattening; while the inferior vena cava …

Interposed Abdominal Compression-Cpr: A Case Study In Cardiac Arrest Research, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

When the abdomen is compressed manually in counterpoint to the rhythm of chest compression, in the performance of interposed abdominal compression-CPR, artificial circulation is approximately doubled in animal experiments and in electronic models of the circulatory system. These studies suggest that external manual compression of the abdominal aorta acts like an intra-aortic balloon pump to increase aortic pressure, whereas external manual compression of the abdominal veins acts to prime the right heart and pulmonary vessels before the next chest compression. As a result, perfusion pressures and flows are increased. Several clinical studies of this technique have shown promising results, including …

Development Of A Rapidly Computable Descriptor Of Prostate Tissue Temperature During Transurethral Conductive Heat Therapy For Benign Prostate Hyperplasia, U H. Patel, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Benign prostate hyperplasia (BPH) is a condition in older men in which the mass of tissue in the prostate gland gradually increases over the course of many years, ultimately leading to urinary outflow obstruction. Current treatment of this condition is to surgically remove the obstructing tissue. One novel alternative therapy being studied is transurethral thermocoagulation of excessive prostatic mass. In this approach, a heat emitting catheter is placed in the prostatic urethra, and the intraprostatic segment of the catheter is heated to temperatures above 60 oC for one hour. Two dimensional cylindrical coordinate computer simulations of this treatment modality were …

Design And Evaluation Of An Augmentative Communication Aid For Multiply Impaired Individuals, Mark S. Annett

Theses and Dissertations

Individuals with sensory and multiple physical impairments, which may include the loss of the ability to speak, have very specialized communication needs. Based on the belief that the current technology does not fully meet these needs, a prototype communication aid was developed for an individual who is cortically blind, dysphonic, and motor impaired. Furthermore, the communication device has broader applications beyond the present individual.

The prototype system has a direct selection of "Yes" and "No" responses, scanning access to daily phrases, rate enhancement of all scans, prompted encoding for selection of letters, two letter codes for complete sentences, access to …