bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct immunoblotting from histological sections of brain onto nitrocellulose: Evaluation with the protein neurophysin
Authors: Reisinger Peter W. M. , Unger Jürgen W.
Published: May 2005

A method for the isolation and localization of proteins and peptides from histological sections of rat and human brain by immunoblottin is described. For validation, the well‐characterized protein neurophysin was electrophoretically transferred from formaldehyde‐fixed or fresh tissue sections onto a nitrocellulose membrane. Neurophysin on the nitrocellulose membrane was detected by a specific antibody reaction. The antibody against neurophysin was visualized either by using secondary antibodies, conjugated with peroxidase or by protein A gold, followed by enhancement with silver. With this simple and fast method, neurophysin (or other proteins and peptides) can be identified on nitrocellulose membranes in areas that correspond to anatomically defined regions. Since the procedure combines the advantages of precise regional localization of polypeptides with the specificity of antibody‐antigen reactions, the method may prove useful for rapid screening of the distribution of peptides or proteins in (brain) tissue.
Involvement of cysteine residues in the electrophoretic mobility of histone H3 in acid‐urea‐Triton gels
Authors: Waterborg Jakob H.
Published: May 2005

Carbamylation of cysteines 96 and 110 in histone H3 increases the electrophoretic mobility of this histone in acetic acid‐urea‐Triton X‐100 polyacrylamide gels but has no effect in gels lacking Triton. Residue 96 appears to be a major determinant in the affinity of histone H3 for the nonionic detergent Triton. Carbamylation and carboxymethylation of cysteine 96 caused a major loss of the gel retardation caused by Triton. Carbamylation of cysteine 110 did not affect Triton binding but prevented ionization of the thiol side‐chain moiety in the acetic acid‐urea‐Triton X‐100 gel.
Serum proteins of rats exposed to organic solvents examined by horizontal two‐dimensional electrophoresis with an immobilized pH gradient in the first dimension
Authors: Zastrow Gabriela , Günther Siegfried , Görg Angelika , Postel Wilhelm , Diehl Horst A. , Jansen Eugéne H. J. M.
Published: May 2005

Serum proteins of exposed to methoxyethylacetate and a combination fo methoxyethylacetate and isobutylacetate, were analyzed horizontal high resolution two‐dimensional gel electrophoresis with immobilized pH gradienets in the first dimension. A total of 410 polypeptide were detected with either increasing or decreasing spot intensities after rat exposure to organic solvents.
Tumor suppressor p53 gene forms multiple isoforms: Evidence for single lucus origin and cytoplasmic complex formation with heat shock proteins
Authors: Selkirk James K. , He Chaoying , Patterson Rachel M. , Merrick B. Alex
Published: May 2005

The tumor suppressor protein p53 is a major cell cycle control factor, and mutations in p53 are the most common genetic lesion found in human tumors, resulting in loss of function and contributing to malignant transformation. This report reviews several studies which show that p53 protein appears as at least eleven isoforms having the same amino acid backbone but varying in charge by level of phosphorylation. All isoforms are derived from a single locus, which indicates that p53 activity is modulated by post‐translational modification. In addition, mutant p53 forms hetero‐oligomers with two families of proteins: HSP70 and a 90 kDa group similar to HSP90. Cytoplasmic complexes are most likely formed to protect p53 from proteolysis and are probably involved in translocation of activated p53 from the cytoplasm to the nucleus for transactivation of other cell cycle control genes.
Analysis of phosphorylated isoforms of the p53 tumor suppressor protein in human lung carcinoma cells undergoing apoptosis
Authors: Maxwell Steve A. , Roth Jack A. , Mukhopadhyay Tapas
Published: May 2005

The expression of p53 tumor suppressor protein isoforms in H460a cells induced to undergo apoptosis by 2‐methoxyestradiol was investigated by two‐dimensional gel electrophoresis. Whole‐cell proteins from control and apoptotic H460a cells were separated by two‐dimensional electrophoresis and were transferred to nitrocellulose. The p53 isoforms were detected by immunoblotting using p53 monoclonal antibody Bp53‐12. Four isoforms of p53 (2, 3, 5, and 6) differing in phosphorylation state were detected in control cells. Three additional isoforms (1, 4, and 7) were observed to be expressed at significant levels only in apoptotic cells. The differential expression of isoforms 1, 4, and 7 in apoptotic cells suggests that one or more specific phosphorylation events generating these forms of p53 could play a role in regulating the function of p53 in apoptosis.
Use of two‐dimensional gel electrophoresis to characterize protein synthesis during neuronal death in cerebellar culture
Authors: Charriaut‐Marlangue Christiane , Dessi Frédéric , Ben‐Ari Yezekiel
Published: May 2005

Two‐dimensional gel electrophoresis was performed to further investigate the biochemical changes in protein synthesis observed in two neuronal death models, induced respectively by cytosine arabinoside and glutamate. These drugs induced, respectively, apoptotic and necrotic types of cell death in cerebellar cultures, as previously reported. Most of the proteins showed decreased labeling after toxic exposure, as expected, but some polypeptides showed increased labeling or appeared to be newly synthesized. The identification of these polypeptides and their implication in neuronal death are discussed.
A critical evaluation of the application of capillary electrophoresis to the detection and determination of 1,4‐benzodiazepine tranquilizers in formulations and body materials
Authors: Smyth W. Franklin , McClean Stephen
Published: May 2005

Studies of the capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) behaviour of 1,4‐benzodiazepines have seen application in subject areas such as the development of pharmaceuticals, therapeutic drug monitoring and forensic toxicology. In the development of pharmaceuticals, pKa determinations by CZE can be used in preclinical studies whereas analytical data on the detection and determination of 1,4‐benzodiazepines is of value primarily in raw material/formulation assay and in the analysis of body fluids in clinical studies. The capillary electrophoresis (CE) techniques, which generally have inferior limits of detection (LOD) to rival techniques such as gas chromatography (GC) and high‐performance liquid chromatography (HPLC), are particularly applicable in forensic toxicology where reasonably high concentrations of these drugs can be encountered. It is anticipated that, with the interfacing of CZE and capillary electrochromatography (CEC) with mass spectrometry (MS) techniques, the excellent selectivity of CZE and particularly CEC will be effectively combined with the sensitivity of MS and the identification capabilities of tandem mass spectrometry (MS/MS) and MS hyphenated (MSn) techniques.
Selectivity manipulation using nonaqueous capillary electrophoresis. Application to tropane alkaloids and amphetamine derivatives
Authors: Cherkaoui Samir , Varesio Emmanuel , Christen Philippe , Veuthey Jean‐Luc
Published: May 2005

Non‐aqueous capillary electrophoresis was investigated for its potential in the analysis of pharmaceutical compounds, namely tropane alkaloids and amphetamine derivatives. The separation of these drugs was compared in aqueous and organic media such as methanol and/or acetonitrile. Selectivity, migration times and efficiency were critically affected by the composition of the methanol/acetonitrile mixture, as well as by the nature and the concentration of the electrolyte. In particular, the migration orders of two positional isomers, littorine and hyoscyamine, were inverted in the presence of trifluoroacetic acid in the nonaqueous medium. The same behavior was observed for amphetamine‐methamphetamine and for two methylenedioxyamphetamine derivatives.
Two examples of rapid and simple drug analysis in pharmaceutical formulations using capillary electrophoresis: Naphazoline, dexamethasone and benzalkonium in nose drops and nystatin in an oily suspension
Authors: Raith Klaus , Althoff Eva , Banse Jutta , Neidhardt Hiltrud , Neubert Reinhard H. H.
Published: May 2005

Capillary electrophoresis is a versatile tool in pharmaceutical analysis. In the course of a revision of the “Standardrezepturen”, a German formula of standard dispensings for preparation in pharmacies, this technique has been applied to drug analysis in pharmaceutical formulations. The present paper deals with two different examples. First, naphazoline, dexamethasone and the preservative benzalkonium are quantified in nose drops without any sample preparation. Second, the antifungal antibiotic nystatin is quantified using nonaqueous capillary electrophoresis in methanol after sample preparation from an oily suspension.
Screening for urinary amphetamine and analogs by capillary electrophoretic immunoassays and confirmation by capillary electrophoresis with on‐column multiwave‐length absorbance detection
Authors: Ramseier Andreas , Caslavska Jitka , Thormann Wolfgang
Published: May 2005

This paper characterizes competitive binding, electrokinetic capillary‐based immunoassays for screening of urinary amphetamine (A) and analogs using reagents which were commercialized for a fluorescence polarization immunoassay (FPIA). After incubation of 25 μL urine with the reactants, a small aliquot of the mixture is applied onto a fused‐silica capillary and unbound fluorescein‐labeled tracer compounds are monitored by capillary electrophoresis with on‐column laser‐induced fluorescence detection. Configurations in presence and absence of micelles were investigated and found to be capable of recognizing urinary D‐(+)‐amphetamine at concentrations > about 80 ng/mL. Similar responses were obtained for racemic methamphetamine (MA) and 3,4‐methylenedioxymethamphetamine (MDMA). The electrokinetic immunoassay data suggest that the FPIA reagent kit includes two immunoassay systems (two antibodies and two tracer molecules), one that recognizes MA and MDMA, and one that is geared towards monitoring of A. For confirmation analysis of urinary amphetamines and ephedrines, capillary electrophoresis in a pH 9.2 buffer and multiwavelength UV detection was employed. The suitability of the electrokinetic methods for screening and confirmation is demonstrated via analysis of patient and external quality control urines.
Analysis of fluorescein isothiocyanate derivatized amphetamine and analogs in human urine by capillary electrophoresis in chip‐based and fused‐silica capillary instrumentation
Authors: Ramseier Andreas , Heeren Franz Von , Thormann Wolfgang
Published: May 2005

Amines can easily be derivatized with fluorescein isothiocyanate isomer I (FITC) and analyzed by capillary electrophoresis (CE) using alkaline buffers with or without dodecyl sulfate micelles. This paper reports the CE analysis of FITC‐derivatized amphetamine, methamphetamine, 3,4‐methylenedioxymethamphet‐amine and β‐phenylethylamine in human urine using chip‐based and fused‐silica capillary instrumentation with laser‐induced fluorescence detection. Data obtained via direct labeling of fortified urine are compared to those generated after FITC labeling of urinary extracts that were prepared by solid‐phase extraction using a copolymer phase. For a urine volume of 5 mL with a “spiked amine”: FITC ratio of 1:250, the latter approach was found to provide a sensitivity that is relevant for toxicological drug screening and confirmation (about 200 ng/mL urine). With direct labeling of 10 μL urine that was alkalinized and diluted for derivatization, the limit of identification was determined to be about 10 μg/mL, a value that is too high for practical purposes. Compared to fused‐silica capillaries, electrophoresis in microstructures is shown to provide faster separations and higher efficiencies without loss of accuracy and precision.
Serum procainamide analysis based on acetonitrile stacking by capillary electrophoresis
Authors: Shihabi Zakariya K.
Published: May 2005

Stacking methods are important in capillary electrophoresis (CE) to overcome the poor detection limits. Cationic drugs are difficult to stack because they tend to interact with the capillary wall. As an example of the stacking of the cationic compounds, procainamide, an anti‐arrhythmic drug, is analyzed in serum by CE using an acetonitrile treatment. Serum was deproteinized with acetonitrile containing quinine as an internal standard. About 12% of the capillary volume was filled with sample and separated using an electrophoresis buffer composed of triethanolamine, 2‐(N‐cyclohexylamino)ethanesulfonic acid (CHES) and 20% isopropanol, pH 8.2. Both the triethanolamine and the CHES were critical for the stacking. The addition of isopropanol improved the plate number for the procainamide and decreased the interfering compounds. Procainamide, its metabolite N‐acetyl procainamide, and quinine were separated in about 7 min. The CE compared well with an immunoassay method.
Capillary ion analysis of lithium concentrations in biological fluids and tissues of Poecilia (teleost)
Authors: Creson Thomas K. , Monaco Paul J. , Rasch Ellen M. , Hagardorn Andrea H. , Ferslew Kenneth E.
Published: May 2005

Capillary ion analysis (CIA) is a form of capillary electrophoresis that uses the differential electrophoretic mobility of ions to perform a separation of an ionic mixture. Application of this technique for detection of lithium concentrations in plasma and tissues of Poecilia was the purpose of this investigation. CIA was performed using a 75 μm ID × 60 cm length fused‐silica capillary and a run electrolyte of 67.7 mg hydroxyisobutyric acid (HIBA), 52.8 mg 18‐crown‐6‐ether and 64 μL UV‐CAT‐1 reagent (4‐methylbenzylamine) in a volume of 100 mL water (18 MΩ) with a voltage of 20 kV using ultraviolet absorption detection at 214 nm. Migration times were: potassium, 2.98 min; calcium, 3.48 min; sodium, 3.60 min; barium (internal standard), 4.15 min and lithium, 4.26 min. Lithium and barium migration times were stable and reproducible. Correlation coefficients (r) between peak area ratios of lithium/barium for concentrations ranging from 0.1 to 2.0 mM were from 0.976 to 0.996. Coefficients of variation (CV) for lithium concentrations ranged from 4.07 to 15.71% between days and 4.38 to 7.76% within‐day. Application of this methodology for determination of lithium concentrations in the plasma, brains and livers of fish dosed with lithium for 23 days are presented. CIA is applicable to analysis of lithium concentrations in biological fluids and tissues of fish.
Monoclonal antibody binding affinity determined by microchip‐based capillary electrophoresis
Authors: Chiem Nghia H. , Harrison D. Jed
Published: May 2005

The affinity constant of a monoclonal antibody to fluorescently labeled bovine serum albumin (BSA*) was measured in diluted mouse ascites fluid using a microfluidic chip to perform affinity capillary electrophoresis. Borofloat glass‐based devices could be used repeatedly with samples for many months. On‐chip separations were performed in less than 60 s, and 30–60 s was required for manual sample exchange. The change in peak height for BSA* with increasing BSA*/anti‐BSA concentration ratio was used to determine concentration changes in bound and free BSA*. A Scatchard plot analysis gave an affinity constant (more exactly the intrinsic association constant) of 3.5 ± 0.6 × 107 M−1 for a 1:1 stoichiometric ratio. Two affinity complexes were separated. One complex was identified by the Scatchard method as having a 1:1 stoichiometric ratio. The other complex is proposed to have a stoichiometry with an excess of anti‐BSA to BSA*, most likely (anti‐BSA)2‐BSA*, on the basis of a faster migration time than the 1:1 complex, a decrease in the amount of this complex with increasing [BSA*], and predictions of theoretical models for multi‐valent antigens. Potential applications of microchip‐based devices in affinity measurements are discussed.
Smoke and fire assessment with the fire propagation test
Authors: Powel D. A. , Martin K. G.
Published: May 2005

Assesing the total potential fire hazard of modern interior surfacing of buildings requires a method which includes determination of smoke toxicity concurrently with fire and smoke production parameters. The Fire Propagation Box Test (British Standards Institution BS 476, Part 6) is a promising contender. It has been examined in the flaming mode as a method for evaluating smoke production concurrently with fire propagation indices for a range of surfacings, rather than resorting to a separate procedure by using fans with the same apparatus, as described in the former British Standards Institution Draft for relation to rate of burning the concurrent procedure is shown to be the more valied method.
Behaviour of concrete under thermal steady state and non‐steady state conditions
Authors: Schneider U.
Published: May 2005

Stress–strain behaviour of concrete at elevated temperatures is extremely complex and is not completely understood up to now. The creep properties of concrete at temperatures up to 300°C thus need to be determined, as well as the thermal stability of concrete during repeated cycles of heating and cooling. In this report the results of recent high temperature experiments with normal concrete specimens are presented. The main objectives of the tests were to investigate the dependence of strength and elasticity on temperature and to study the creep and deformation characteristics of concrete at temperatures up to 450°C. Transient creep data, i.e. data derived under transient temperature conditions, are compared with creep data which were measured at constant elevanted temperatures. The results suggest that transient creep values and steady state creep values in some cases may be of the same magnitude.

The creep measurements appear to be in good agreement with data presented by other workers. However, the scatter in all data increases significantly with increasing temperature and differences of more than 100% can be observed. When loaded concrete specimens were cooled down to ambient temperature exptraordinarily large compressive strains can be observed. The experiments indicate clearly the considerable strain capacity of normal structural concrete can be used at temperatures higher than 100°C. In areas of high stress concentrations a tures. On the other hand, with respect to the whole structure it is necessary to limit the deformations. For a constant maximum temperature this can only be done by limiting the admissible stresses. The test results permit an initial estimation of maximum permissible stress and temperature values.
Interferences in the determination of nitrogen dioxide in a chemiluminescent analyser
Authors: Felstead D. K. , Maddison P. , Reilly D. A.
Published: May 2005

A commercial chemiluminescent nitrogen oxides analyzer performed well in its nitric oxide mode when applied to the combustion products of polyurethane materials, but when test gases were passed through a thermal converter prior to measurement of nitrogen dioxide, serious, interferences was encountered from hydrogen cyanide and other nitrogen compounds.
Combustion inhibition of cellulose by powders: Preliminary data and hypotheses
Authors: McCarter R. J.
Published: May 2005

Small‐scale qualitative tests were used to screen 185 inorganic powders for flame and inhibiting effects upon cellulose. Nearly half of the compounds inhibited smoldering. These were limited to inorganic salts whose anions include boron, phosphorus, sulfur or halogen. Over half the compounds inhibited flaming, and about one‐third inhibited both flaming and smoldering. Differences were found between the actions of the powders and of similar retardants used in other forms and conditions. An appendix is included reporting the effects of alkali metal halides on the pyrolysis of cellulose. Implications of the results to the inhibitors are discussed.
An improved affinity support and immunoadsorbent with a synthetic blood group oligosaccharide and polymer coating for hemoperfusion
Authors: Mazid M. Abdul , Kaplan Marie
Published: May 2005

An improved affinity support and an immunoadsorbent suitable for extracorporeal perfusion of whole blood (or plasma) are reported. The affinity support consists of calcined diatomite‐type silica particles to which a synthetic oligosaccharide hapten, viz. Atrisaccharide representing human blood group A, with a linking spacer‐arm is chemically attached. The immunoadsorbent thus obtained is surface‐modified with a polymer coating. The modified immunoadsorbent is not hemolytic and shows no loss of biological activity in reducing antibody titers in vitro. An important feature of the improved immunoadsorbent is that the polymer coating providesa better surface resistance and therefore stability to the affinity support to prevent the release of potentially harmful fines. The usefulness of a physically stable support as an affinity adsorbent for the selective removal of specific antibodies or unwanted substances directly from the blood circulation by extracorporeal immunoadsorption has profound medical significance because this would provide an efficient but safe and practical alternative to therapeutic intervention using plasma exchange or plasma perfusion, both of which require plasmapheresis.
Acrylic bone cements: Residuals and extractability of methacrylate monomers and aromatic amines
Authors: Trap Birna , Wolff Per , Jensen Jørgen Steen
Published: May 2005

A new formulation of acrylic bone cement [methylmethacrylate/n‐decylmethacrylate/isobornylmethacrylate (MMA/DMA/IBMA)] developed with the purpose of reducing the biologic adverse effects of bone cements was analyzed by high performance liquid chromatography for residual content of monomers and aromatic amines from the accelerator system [dimethyl‐p‐toluidine (DMPT), dihydroxypropyl‐p‐toluidine (DHPPT)] in the cured cement and for concentrations of these constituents in hydrophilic and lipophilic eluates. In comparison with conventional polymethyl‐methacrylate acrylics a considerable reduction of both released and residual MMA was experienced, being about 10‐ to 15‐fold. The residual content of the new DMA and IBMA monomers were 0.35% and 0.66%, respectively, in cured cement after 72 h and these could only be detected in the paraffin eluates. The residual content of aromatic amines was considerably reduced with the new cement formulation. No DMPT could be detected and the DHPPT represented a 3‐ to 4‐fold reduction in cured cement and a 8‐ to 10‐fold reduction in eluates. The residual DHPPT content of about 0.07% was found to be practically constant with time. It is concluded that MMA/DMA/IBMA cement cures faster and more completely.
Preliminary effects of in vitro lipid exposure on absorbable poly(ortho ester) films
Authors: Andriano Kirk P. , Chang Melissa K. O. , Daniels A. U. , Heller Jorge
Published: May 2005

Bioabsorbable films show promise in preventing postoperative interfacial tissue adhesion. Absorbable polymers in film form are generally more sensitive to chemical environments, due to their large surface area to volume ratio. The in vivo environment contains lipids such as cholesterol, triglycerides, and phospholipids, which are known to affect the degradation of permanent and absorbable polymeric biomateials. Preliminary investigations of in vitro lipid exposure of bioabsorbable poly(ortho ester) (POE) films for implant use are described. POE has been studied previously for use in controlled drug delivery and fracture fixation. Six‐week in vitro exposure of 65:35 POE films to a cholesterol emulsion (1 g/L) showed no apparent difference in hydrolytic degradation rates of mechanical properties or mass loss compared to deionized water exposed films. Decreases of 28 and 6% in inherent viscosity were observed after 5 weeks for cholesterol and deionized water exposed films, respectively, suggesting cholesterol may have some effect. Further examination of the data, due to sample variation, revealed that clear, uniform films showed only minor changes in mass loss and mechanical properties after 6 weeks in either of the in vitro media. But slightly cloudy films possessing microscopic bubbles showed accelerated degradation in both media, indicating the effect of cholesterol was inconclusive due to sample variation. Control of the microbubble formation process could have utility in controlling hydrolytic degradation of POE films. © 1995 John Wiley & Sons, Inc.
Experimental anastomoses of small arteries employing alkyl‐cyanoacrylates
Authors: Herrmann John B. , Katz Abraham R. , Woodward Stephen C.
Published: May 2005

Sutured, stapled, and methyl‐ or thickened n‐pentyl‐2‐cyanoacrylate‐adhered end‐to‐end arterial anastomoses were compared in two series of 10 dogs, employing the three 4‐mm diameter terminal branches of the aorta for these comparisons. Patency rate, speed of construction, and gross and microscopic appearances were employed as criteria for evaluation. In a series of adult white rabbits the same criteria were applied to compare sutured and thickened n‐pentyl‐2‐cyanoacrylateadhered end‐to‐end anastomoses of the 2‐mm diameter abdominal aorta. Anastomoses adhered with methyl‐2‐cyanoacrylate were significantly more often thrombosed than any other variety; a marked inflammatory response followed application of this material. Thickened n‐pentyl‐2‐cyanoacrylate adhesive was well tolerated, and the results obtained with this material were equivalent to those obtained by suturing or stapling in the dog, or by suturing in the rabbit.
Confirmation of the presence of β(AgHg) in dental amalgam
Authors: Johnson Lewis B.
Published: May 2005

The presence of the β1 phase in dental amalgam after 60°C heating has been confirmed by x‐ray diffraction, metallography, microhardness tests, and electron beam analysis. It appeared that the γ1 → β1 transformation began at preferred sites, believed to be possibly areas deficient in Hg, and grew outward from these sites. Even after heating for nearly a year, however, some γ1 still remained in the sample.
The behavior of biological materials at different sites of implantation
Authors: Kaminski Edward J. , Oglesby Richard J. , Wood Norman K. , Sandrik James
Published: May 2005

Adult albino rabbits were implanted with disks of 316 and 304 stainless steel in the subperiosteum of the anterior calvarium and the left mandible and in the left paravertebral and thigh muscles. The corresponding opposite sites were sham operated. The histopathological slides revealed that there was variation in thickness of the membrane in sections of both the paravertebral and thigh muscles; one side showing greater reaction than the other, which corresponded with the appearance of the implants. Sections of the calvarium revealed minimal bone and soft tissue reaction, although the implants showed corrosion compatible with soft tissue sites. The mandibular sections revealed extensive bone tissue reactions with minimum masseter muscle reactions, but the appearance of the implants due to corrosion was different than those of all other sites. Moderate eosinophilic infiltration was observed in sections containing deposits of corrosion products.
Discussion of correlations of blood coagulation with surface properties of materials
Authors: Bischoff Kenneth B.
Published: May 2005

An alternate correlation of blood coagulation time with surface properties of solids is proposed in that the work of adhesion is used rather than the surface free energy. The overall quality of the two correlations is about the same, but the new method does allow the important data point for glass to also be included. Possible useful future work of this type is discussed.
Implantation of autologous tissue fragments in velour fabric used to line cardiovascular prostheses: An in vivo culture system to produce cellular blood–prosthesis interfaces
Authors: Ghidoni John J. , Liotta Domingo , Adams J. Gordon , O'Neal Robert M. , Hall C. William
Published: May 2005

Previous observations of pseudointimal organization within impermeable cardiovascular prostheses indicated that rapid spontaneous healing was dependent upon proximity of host vascular tissue at the suture line. Autologous connective tissue fragments were prepared from skeletal muscle biopsies by blender‐mincing muscle tissue. The fragments were embedded in the fabric used to line the inner wall of arterial prostheses. A tightly fitting piston was drawn through the prosthesis, forcing the suspended tissue fragments to flow around the piston and become entwined in the loops of the velour fabric. The arterial prostheses prepared in this way were inserted as replacements for segments of canine abdominal aorta. This in vivo culture system supported cellular proliferation and pseudointimas healed uniformly. Pseudointimas of paracorporeal pumps in operation for as long as 5 weeks did not show signs of healing. The same principle of filtration of tissue fragments into a lining fabric was applied to diaphragms of left ventricular bypass pumps. This type of paracorporeal pump supported in vivo culture of implanted fragments.
Use of spongy hydron in plastic surgery
Authors: Kliment K. , Štol M. , Fahoun K. , Stockar B.
Published: May 2005

A hydrophilic plastic material (USA trademark Hydron), developed by Wichterle and Lím, was used as a sponge for augmentation of breasts in the clinic for plastic surgery. The preparation of the prosthesis and the operational procedures are described.
Experimental experiences with the collagen sponge as hemostaticum and tampon
Authors: Chvapil M. , Holuša R.
Published: May 2005

The paper sums up experimental data for the preparation of a collagen sponge to be used as hemostaticum or tampon. Optimal conditions were found with respect to the degree of porosity and tanning of the sponge in order to attain both these properties separately. The native sponge partially ages by storage and its stability increases with increase of temperature during storage. The heat‐induced stability of the sponge, however, is not as great as the stability induced by tanning agents. No effect of irradiation on the stability of the collagen sponge was found within doses of 1–10 Mrad. The speed of resorption and tissue reaction of the subcutaneously implanted native and tanned collagen sponge was followed up and no hypersensitive reaction by the tissue was found. However, different reactions of the tissue to native and to tanned sponge were ascertained.
The toxicogenic potential of medical plastics sterilized with ethylene oxide vapors
Authors: O'Leary Robert K. , Guess Wallace L.
Published: May 2005

Ethylene oxide appears to be an ideal sterilant for many heat‐sensitive items, but there are a number of disadvantages which require caution in its usage. Ethylene oxide has some deleterious effects on certain plastics and rubber. In particular, it acts as a solvent on such acrylic plastics as Lucite and Plexiglas, and it will attack the plasticizers found in many flexible medical‐grade tubing formulations. Perhaps more significant is the fact that this sterilant can produce some serious toxic manifestations when medical plastics are not properly degassed. This paper reviews some of the toxicities already reported in the medical literature and also presents new data on the hemolysis liability of many gassterilized pharmaceutical plastics. Both human blood hemolysis studies and cell culture data on 18 different polymers suggest that plasticized vinyl plastics have the highest toxicogenic potential. Experimental data presented on the solubility and partial pressure of ethylene oxide in a homologous series of phthalic acid esters indicate that the structure and concentration of plasticizers play a major role in the selection of the most effective degassing procedures to be used following ethylene oxide sterilization.
Study on a new soft denture liner of the sofdent type
Authors: Kliment K. , Štol M. , Raab M. , Štokr J.
Published: May 2005

It has been shown that the admixture of diacetins in the capacity of a diluent in the polymerization of hydrophilic poly(ethyleneglycol methacrylate) gels improves the properties of products used as soft denture liners, especially by inhibiting the volume changes caused by swelling, and by improving the mechanical properties of gels as well as the strength of bond between the gel and the basic material of the prosthesis.
Use of porous ceramics to obliterate mastoid cavities
Authors: Leonard Ralph B. , Sauer Barry W. , Hulbert Samuel F. , Per‐Lee John H.
Published: May 2005

The mastoid process of the temporal bone can become infected with possible serious complications. If the infection does not respond to antibiotics, the infected area must be surgically removed, with the result that a cavity is formed. This cavity must be obliterated before the soft tissues can be closed over the site.

Many biological tissues have been used in attempts to obliterate the mastoid cavity. Fat grafts and diced cartilage have shown less than optimum success because of their tendency to suffer various degrees of resorption. The most popular obliterative technique has been the musculoplasty in which a flap is cut from the temporalis muscle and rotated into the cavity. This method shows a great deal of success, but is a difficult procedure to do since the flap must be provided with adequate vascularity and must be cut to exactly the correct length. Hence this procedure works best for otologic surgeons who have had a great deal of experience in this method.

Various forms of ceramics (either impervious spheres or porous pieces) have been used to obliterate the surgically produced cavity in the feline tympanic bulla. This bulla is a common model for the human mastoid. Since the ceramics must only fill the cavity and no stress is involved in this application, the brittle nature of ceramics is not a factor in their usefulness.

The ceramics are held in place well by the ingrowing soft tissue and hence obliterate the cavity. Porous pieces of alumina seem to be best from the point of view of rapid tissue ingrowth holding them in place faster than the impervious spheres which require tissue to grow around them.

The use of bioceramics to obliterate mastoid cavities would lead to an obliterative procedure in which an otologic surgeon would only have to excavate the infected cavity, fill it with ceramics, and close the site. He would not have to be involved with the tricky business of tailoring muscle flaps or obtaining homologous or autologous tissue.
Polyester textile bioadhesion to muscle and bone
Authors: Dunn Harold K. , King Robert , Andrade Joseph D. , de Vries Kenneth L.
Published: May 2005

Surgical repair of injuries to the flexor tendons of the hand does not give satisfactory clinical results. In an attempt to solve this clinical problem, basic studies have been done aimed at developing an artificial tendon. In this paper, the anatomy of the flexor tendons and the physiology of their wound healing is related to the clinical problems encountered in this type surgery. It is proposed that a satisfactory way to solve this clinical problem is development of a permanently implantable functional flexor tendon prosthesis. Dacron polyester fabric of four various weave configurations were implanted into the musculotendinous junction of rabbits and into the femurs of dogs for periods varying from 2 to 8 weeks. The strength of the ingrowth into these fabrics was mechanically measured and related to surface area and porosity of the implant. Histological studies of the ingrowth was made. It would appear, at the musculotendinous junction, the strength of the ingrowth into the implant is primarily dependent on the internal fabric porosity and not the surface morphology. The strength of the ingrowth from the bone into the implant exceeded the strength of the materials in all specimens.
Replacement of intervertebral discs in chimpanzees by silicone‐Dacron implants: A preliminary report
Authors: Urbaniak James R. , Bright Donald S. , Hopkins Jay E.
Published: May 2005

We have developed a prosthetic replacement for the intervertebral disc. Although current management of a patient with degenerative disc disease is usually effective, certain inadequacies in permanent pain relief do exist. Most of the persistent symptoms seem to occur because of vertebral settling with subsequent posterior joint incongruities followed by arthritic changes. Theoretically, the replacement of a diseased intervertebral disc, prior to the onset of irrevocable changes, with a spacer would maintain anatomical congruity and physiologic function. This study is the preliminary report of the development of a silicone‐Dacron prosthesis and its experimental trials in chimpanzees. Our early evaluation shows that the prosthesis allows motion, maintains the intervertebral space, and absorbs the compressive stresses placed on the spine. The artificial disc has a biomechanical behavior comparable to the normal chimp disc. Resorption of adjacent bone, reactive bone formation, and infection are complications that we have experienced. Continued evaluation is necessary.
Studies on the skeletal attachment of experimental hip prostheses in the pygmy goat and the dog
Authors: Esslinger John O. , Rutkowski Edward J.
Published: May 2005

Significant hazards to the use of femoral head prostheses–infection, corrosion, fatigue failure, interface motion, latent failure–dictate new standards for new prosthesis models. This study investigates ceramic‐coated metal hip prostheses which have the theoretical advantage of tissue ingrowth. In long‐term analysis, ingrowth did not occur in this study in the pygmy goat. Sintered metal prosteses were inserted in two dogs with bilateral congenital hip dysplasia. Excellent clinical results were obtained with radiologic evidence of bone envelopment of the sintered metal. Based on previous applications of silicone rubber to weight bearing by the author, the advantages of a silicone rubber prosthesis or silicone rubber‐covered prosthesis are tissue compatibility, new bone formation, peak stress dispersal, and simulation of normal articular cartilage. A silicone rubber prosthesis was fabricated for the pygmy goat. It was inserted and initially has given good clinical results.
Stress distribution in bone arising from loading on endosteal dental implants
Authors: Tesk J. A. , Widera O.
Published: May 2005

Results of a preliminary study of stress in bone around dental implants are presented. Stress is calculated using the method of finite elements. Two blade type and one pin type implant are subjected to horizontal and to vertical forces of 19 lb. Differences in blade implant design do not alter the stress distribution significantly. The pin implant shows that most of the load is carried near the entrance into the bone, with a rapid fall in stress.
The biomechanics of the epiphyseal lines as a guide to design considerations for the attachment of prosthesis to the musculo‐skeletal system
Authors: Bechtol Charles O.
Published: May 2005

The configuration of epiphyseal lines in the growing mammal is extremely variable depending upon the principal stresses applied to the specific epiphysis in question. Because man is not highly specialized for rapid locomotion, the configuration of epiphysis in the human is not as well developed as that seen in animals specialized for rapid running, such as the artiodactyls. The several different typical configurations of the epiphyseal line are described and demonstrated in photographs using the deformed coordinate method. It is suggested that when coupling of porous structures, such as ceramics to bone, has been adequately worked out, configurations similar to those seen in the epiphyseal lines may be a successful method of attaching the prosthetic part to bone.
Mechanical properties of the bone‐porous biomaterial interface: Elastic behavior
Authors: Moyle D. D. , Klawitter J. J. , Hulbert S. F.
Published: May 2005

The possibility of evaluating the elastic moduli of the bone‐porous biomaterial interface by treating it as a two‐phase composite is discussed. Methods of placing bounds on the elastic moduli of such a composite are presented and applied to five materials currently being considered for use in porous prosthetic devices: 316 stainless steel, titanium, cobalt‐chromium‐molybdenum alloy (Vitallium), alumina (Al2O3), and high density polyethylene. The results show that when the prosthetic material becomes completely ingrown with bone, the elastic modulus of the composite becomes more compatible with bone. Titanium appears to be very favorable. Young's modulus for bulk titanium is about four times that of bone, while the fully ingrown composite has a Young's modulus approximately twice that of bone. Similar results obtain for the other elastic moduli. It is noted that the results for 316 SS apply to all surgical stainless steels, those for Co‐Cr‐Mo apply to other Co‐Cr alloys and those for titanium apply to alloyed titanium.
Corrosion product formation sequence on Cu‐rich amalgams in various solutions
Authors: Lin Jiin‐Huey C. , Marshall Grayson W. , Marshall Sally J.
Published: May 2005

A single particle and four blended Cu‐rich amalgam systems were immersed in 37 °C solutions for 1–20 months in order to determine the characterization and sequence of corrosion product formation. X‐ray diffraction and SEM/EDS were used to characterize the products. The same sequence of formation occurred in all systems in Ringer's and 0.1% Ringer's solutions. The times at which each product formed varied with the brand of the amalgam and the concentration of the solution. The initial products were ZnSn(OH)6 in Zn‐containing systems and SnO2 in most other systems. Cu2O formed next, followed by CuCl2·3Cu(OH)2. Immersion in 1% Na2S yielded only HgS on all brands. A combination of 1% Na2S and Ringer's solution yielded CaSn(OH)6 after 2 months and Cu2O at later periods. Artificial saliva resulted in a retardation of corrosion product formation and only limited amounts of a Sn‐rich product could be found after 20 months. Interactions of the various components appear to alter the nature and rate of corrosion product formation on these systems and additional systematic investigations are necessary to understand the influence of these interactions on corrosion.
The mechanisms of passive dissolution of titanium in a model physiological environment
Authors: Healy Kevin E. , Ducheyne Paul
Published: May 2005

The surface chemistry, oxidation, and dissolution kinetics of titanium were measured to establish the mechanisms of passive dissolution in physiological environments. Titanium thin films were immersed in 8.0 mM ethylenediamine‐ tetraacetic acid in simulated interstitial electrolyte (EDTA/SIE) and maintained at 37°C, 10% O2, 5% CO2 and 7.2 pH for periods of time up to 3200 h (133 days). Two immersion schemes were employed: the integral sequentially determined the titanium released into a solution of accumulated dissolution products; and the differential continuously replenished the test solution. The solutions were analyzed for titanium by electrothermal atomic absorption spectrometry (EAAS), and the sample surfaces were analyzed by Auger electron spectroscopy (AES) and x‐ray photoelectron spectroscopy (XPS) to determine oxide composition, stoichiometry, and thickness. Prior to immersion two types of hydroxyl (OH) groups were distinguished on the TiO2 surface. Upon immersion, the chemistry of the surface changed as a function of immersion: the presence of OH groups increased and P (nonelemental) was detected at the surface. The dissolution kinetics obeyed a two‐phase logarithmic model, where the transition between phases occurred simultaneously with the adsorption of the P‐containing species. The dissolution kinetics depended on surface reactions, electric field strength, and molecular diffusion. These mechanisms explain the observed dependence of dissolution kinetics on the properties of the surface oxide and solution ligands.
Ex vivo and in vitro platelet adhesion on RFGD deposited polymers
Authors: Kiaei David , Hoffman Allan S. , Hanson Stephen R.
Published: May 2005

Clinical applications of small‐diameter synthetic vascular grafts are hindered by their highly thrombogenic surfaces. To develop vascular grafts that resist thrombotic occlusion, a radio frequency glow discharge (RFGD) process was employed to modify the surface of existing graft materials. Ultrathin coatings of RFGD polymers of ethylene (E), tetrafluoroethylene (TFE), and hexamethyldisiloxane (HMDS) were deposited on the lumen of Dacron grafts. Surfaces were characterized by electron spectroscopy for chemical analysis (ESCA). The effect of glow discharge treatments on plateletgraft interactions was evaluated in an ex vivo baboon shunt model. Following placement of an untreated or RFGD‐ treated graft in the shunt, deposition of 111Indium‐labeled platelets was monitored for 60 min by γ camera imaging. Untreated Dacron rapidly accumulated large numbers of platelets, reaching a plateau i n 60 min. HMDS‐ and TFE‐treated Dacron had significantly lower levels of platelet deposition compared to the untreated control. In contrast, the ethylene treatment of Dacron augmented platelet deposition, making it the most platelet‐ adherent surface studied. In vitro studies were also performed using untreated and RFGD‐treated poly (ethylene terephthalate) (PET) coverslips. ESCA verified that the surface composition of the untreated and RFGD‐treated coverslips were virtually identical to their untreated and treated Dacron graft counterparts. Samples were incubated in washed baboon platelet suspensions for 2 h at 37°C. Platelet adhesion on the untreated PET was relatively high, and many of the platelets had a completely spread morphology. The HMDS and TFE treatment of PET reduced the number of adherent platelets and prevented platelet spreading on the surface. Platelet adhesion and spreading on the ethylene‐treated surface was the highest among the four studied. There is a remarkable linear correlation of the ex vivo and in vitro platelet adhesion data.
Glow discharge plasma deposition of tetraethylene glycol dimethyl ether for fouling‐resistant biomaterial surfaces
Authors: Löpez Gabriel P. , Ratner Buddy D. , Tidwell Caren D. , Haycox Claire L. , Rapoza Richard J. , Horbett Thomas A.
Published: May 2005

The glow discharge plasma deposition (GDPD) of tetraethylene glycol dimethyl ether is introduced as a novel method for obtaining surfaces that are resistant to protein adsorption and cellular attachment. Analysis of films by x‐ray photoelectron spectroscopy and several biological assays indicate the formation of a foulingresistant, PEO‐like surface on several substrata (e.g., glass, polytetrafluoroethylene, polyethylene). Adsorption of 125I‐radiolabelled proteins (fibrinogen, albumin and IgG) from buffer and plasma was very low (typically <20 ng/cm2) when compared to the untreated substrata, which exhibited much higher levels of protein adsorption. Not all coated substrata adsorbed equal amounts of protein (e.g., coated glass samples typically adsorbed more protein than coated polyethylene or coated polytetrafluoroethylene samples), suggesting that the substratum used may affect the amount of protein adsorbed. Measurement of dynamic platelet adhesion, using epifluorescent video microscopy, and endothelial cell attachment further demonstrates the short‐term nonadhesiveness of these surfaces.