Showing papers by "University of Texas System published in 1993"

Gels for encapsulation of biological materials

Abstract: Water soluble macromers are modified by addition of free radical polymerizable groups, such as those containing a carbon-carbon double or triple bond, which can be polymerized under mild conditions to encapsulate tissues, cells, or biologically active materials. The polymeric materials are particularly useful as tissue adhesives, coatings for tissue lumens including blood vessels, coatings for cells such as islets of Langerhans, coatings, plugs, supports or substrates for contact with biological materials such as the body, and as drug delivery devices for biologically active molecules.

Photopolymerizable biodegradable hydrogels as tissue contacting materials and controlled-release carriers

Abstract: Hydrogels of polymerized and crosslinked macromers comprising hydrophilic oligomers having biodegradable monomeric or oligomeric extensions, which biodegradable extensions are terminated on free ends with end cap monomers or oligomers capable of polymerization and cross linking are described. The hydrophilic core itself may be degradable, thus combining the core and extension functions. Macromers are polymerized using free radical initiators under the influence of long wavelength ultraviolet light, visible light excitation or thermal energy. Biodegradation occurs at the linkages within the extension oligomers and results in fragments which are non-toxic and easily removed from the body. Preferred applications for the hydrogels include prevention of adhesion formation after surgical procedures, controlled release of drugs and other bioactive species, temporary protection or separation of tissue surfaces, adhering of sealing tissues together, and preventing the attachment of cells to tissue surfaces.

Multi-Phase Bioerodible Implant/Carrier and Method of Manufacturing and Using Same

Abstract: A carrier and method of manufacturing and using the same is provided for receiving supporting replenished tissue growing into a diseased or damaged area within a physiological system. The carrier can be implanted in the interface region between tissue having different mechanical properties to support the growth and regeneration of differing types of tissue within the region. The carrier includes bioerodible polymeric material having differing mechanical properties such as porosity, stiffness and compressibility.

Methods for targeting the vasculature of solid tumors

Abstract: The present invention relates generally to methods and compositions for targeting the vasculature of solid tumors using immunological- and growth factor-based reagents. In particular aspects, antibodies carrying diagnostic or therapeutic agents are targeted to the vasculature of solid tumor masses through recognition of tumor vasculature-associated antigens, such as, for example, through endoglin binding, or through the specific induction of endothelial cell surface antigens on vascular endothelial cells in solid tumors.

The Induction and Repair of DNA Photodamage in the Environment

Abstract: Since its discovery in bacteria 25 years ago, DNA repair, particularly in response to damage induced by UV radiation, has been a major focus of molecular biology. The roles played by DNA damage and repair in the aging and carcinogenic processes have been of particular interest. More recently, degradation of stratospheric ozone and the resultant increase in UV-B radiation at the earth’s surface have focused our attention on the environmental effects of solar DNA damage. Although we have learned much about DNA damage tolerance mechanisms in prokaryotes and some lower eukaryotes, our understanding of the molecular events that determine biological effects of UVR in complex higher eukaryotes is far from complete.

Interactive external defibrillation and drug injection system

Abstract: This invention involves an interactive external defibrillation and drug injection system for use by a human operator for treating cardiac conditions in a patient, particularly in an out-of-hospital or pre-hospital environment. The present invention may also be used within hospitals as well as where intravenous (IV) access has not been established. More specifically, this invention comprises measuring devices capable of measuring and monitoring various physiological indicators in a patient and an expert system capable of analyzing the measured data and making recommendations to an operator for treatment of the patient using any combination of defibrillation, cardioversion, transcutaneous pacing, or vascular drug delivery via intraosseous drug injection. This invention is designed to enable first responders to cardiac emergencies to provide care up to the standard of at least the beginning stages of Advanced Cardiac Life Support (ACLS).

Antibacterial coated medical implants

Abstract: An implantable medical device having long lasting resistance to staphylococcal biofilm colonization is provided. Implantable medical devices such as catheters, shunts, prosthesis, pacemakers, etc. are susceptible to colonization by biofilm adherent microorganisms, especially staphylococci. While systemic staphylococcal infections are effectively treated by many antibiotics, vancomycin being the antibiotic of choice, this same bacteria when encased in biofilm adhering to indwelling medical devices is generally resistant to antibiotic treatment. By the present invention, the combination of rifampin and minocycline or the combination of rifampin and novobiocin when coated on the surfaces of implantable medical devices unexpectedly provides superior antibacterial activity against staphylococcal biofilm colonization on the coated surface of indwelling medical devices.

Therapy and diagnosis of conditions related to telomere length and/or telomerase activity

Abstract: Method and compositions are provided for the determination of telomere length and telomerase activity, as well as the ability to inhibit telomerase activity in the treatment of proliferative diseases. Particularly, primers are elongated under conditions which minimize interference from other genomic sequences, so as to obtain accurate determinations of telomeric length or telomerase activity. In addition, compositions are provided for intracellular inhibition of telomerase activity and means are shown for slowing the loss of telomeric repeats in aging cells.

Process for making custom joint replacements

Abstract: A process for forming a prosthesis related to bone structure internal to a body using CT scan data corresponding to the radiological density of the bone structure to derive the inner and outer bone surface contours. The density and the density gradient of discrete points in the bone structure is compared to threshold density levels and to threshold density gradient levels and points are selected to form a series of interim outer contours. A contour shape factor is derived for each interim outer contour, and that interim contour is chosen in which the contour shape factor is maximum denoting less fluctuations in the contour circumference. The bone surface contour data is used to develop a graphic model from which a set of digital data is generated for a surface model representing the graphic model. A set of numerical control machine instructions are generated to make the prosthesis.

Selective laser sintering using nanocomposite materials

Abstract: A method of fabricating three-dimensional objects in a layerwise fashion, and having high structural strength and high density, is disclosed. Methods are disclosed by which nanocomposite powders of ceramic-ceramic systems, ceramic-metal systems, ceramic-polymer systems, and metal-polymer systems are produced. Disclosed examples utilize solution chemistry approaches, such as sol-gel processing, by way of which a gel is produced which is then fired and milled to form a powder suitable for selective laser sintering, where a laser fuses selected portions of layers of the powders according to a computer-aided-design data base. The ultraheterogeneity of the powder results in larger surface area and grain boundaries of the constituents, which enhances the solid state diffusion mechanism, and thus reduces the time and temperature required for sintering to occur. In addition, the higher stored metastable energy of the nanocomposite powder is believed to enhance densification during solid-phase sintering. Objects of high density of complex shape may thus be obtained directly from CAD data base design representations.

Bacterial host strains for producing proteolytically sensitive polypeptides

Abstract: The invention relates to methods of producing recombinant polypeptides in protease-deficient bacterial hosts. Constructs of single, double, triple and quadruple protease deficient and protease/rpoH mutants of E. coli are described. Proteolytically sensitive polypeptides may be expressed and secreted in such cells, providing significantly increased yields compared with expression in wild-type strains.

Methods and compositions for targeting the vasculature of solid tumors

Abstract: The present invention relates generally to methods and compositions for targeting the vasculature of solid tumors using im-munologically-based reagents. In particular aspects, antibodies carrying diagnostic or therapeutic agents are targeted to the vas-culature of solid tumor masses through recognition of tumor vasculature-associated antigens, or through the specific induction of endothelial cell surface antigens on vascular endothelial cells in solid tumors.

Method and apparatus for direct spectrophotometric measurements in unaltered whole blood

Abstract: A method and apparatus which allow accurate spectrophotometric determinations of the concentrations of various hemoglobin species in whole blood without hemolysis or dilution. To overcome complex optical properties of whole blood, the invention employs 1) an optical apparatus (10, 11, 12, 13 and 14), designed to maximize the true optical absorbance of whole blood and to minimize the effects of light scattering on the spectrophotometric measurements of concentrations of various constituent components, and 2) methods to correct the hemoglobin concentration measurements for light scattering and for the effects of the finite bandwidth of the substantially monochromatic light. In the optical apparatus, (10-14), (including an optical cuvette (11)) all optical parameters, such as sample thickness, detector size and shape, sample to detector distance, wavelengths, monochromicity, maximum angle of light capture by detector, are optimal values to minimize the contribution of light scattering to the total optical attenuation of unaltered whole blood and maximize contribution of true optical absorbance.

Method of isolation and purification of fusion polypeptides

Abstract: Methods for isolation and purification of recombinant proteins are described. Fusion proteins incorporating a cleavage site sensitive to proteolysis by a plant virus proteinase may be cleaved from carrier proteins to provide high yields of protein product. Methods employing a plant virus proteinase to cleave expressed fusion proteins are particularly suitable for obtaining proteolytically sensitive polypeptides in the presence of added cell protease inhibitors. Also disclosed are recombinant vectors useful for overproducing plant virus proteinases in a suitable host.

Dentin sialoprotein: biosynthesis and developmental appearance in rat tooth germs in comparison with amelogenins, osteocalcin and collagen type-I.

Abstract: A non-collagenous protein, extracted from rat incisor dentin, is a dentin sialoprotein (DSP). We examined immunohistochemically the developmental appearance and tissue distribution of DSP in 1 to 3-day-old rat molar and incisor tooth germs. The earliest staining for DSP was observed in newly differentiated odontoblasts. In more advanced stages, immunostaining for DSP gradually increased in pre-dentin, odontoblasts and dentin, and appeared in many cells of the dental papilla. In early stages of development before the breakdown of the dental basement membrane, pre-ameloblasts were also positive for DSP. This staining disappeared from the ameloblast cell body soon after deposition of the first layer of mineralized dentin. Radiolabelling of tooth matrix proteins with 14C-serine in vitro followed by immunoprecipitation and fluorography confirmed that DSP was synthesized by tooth-forming cells. The immunolocalization for DSP was different from that of either collagen type-I, osteocalcin or the amelogenins. Whereas collagen type-I and osteocalcin were restricted to the mesenchymal dental tissues, the amelogenins were detectable in both epithelial and mesenchymal dental cells and tissues at the epithelio-mesenchymal interface at early stages of development, prior to the onset of dentin mineralization. We conclude that DSP is expressed in and secreted by odontoblasts and some dental papilla cells from early stages of dentinogenesis onwards, i.e. later than type-I collagen, but before deposition of the first layer of mineralized dentin. In pre-mineralizing stages, some of the matrix proteins may be endocytosed from the pre-dentin by both cell types involved in the epithelio-mesenchymal interaction.

The signal recognition particle database (SRPDB).

Abstract: This release of the SRPDB (signal recognition particle database, http://pegasus.uthct.edu/SRPDB/SRPDB . html ) adds four SRP RNA sequences (a total of 99 SRP RNA sequences), 23 SRP protein sequences (a total of 63 protein sequences from SRP9, SRP14, SRP19, SRP21, SRP54, SRP68 or SRP72), and, for the first time, sequences of the alpha subunit of the eukaryotic SRP receptor and its homologous bacterial proteins (a total of 21 sequences). Sequences are offered phylogenetically ordered, annotated with links to the primary databases, and in aligned form. Also downloadable are sample SRP RNA secondary structure diagrams, three-dimensional models of representative SRP RNAs, and search motifs.

Metal complexes of water soluble texaphyrins

Abstract: The present invention involves water soluble hydroxy-substituted texaphyrins retaining lipophilicity, of formula (I) wherein: M is H, a divalent or a trivalent metal cation; R1, R2, R3, R4 and R5 are independently H, OH, C n H(2n+1)O y or OC n H(2n+1)O y where at least one of R1, R2, R3, R4 and R5 has at least one hydroxy substituent; the molecular weight of any one of R1, R2, R3, R4 or R5 is less than or equal to about 1000 daltons; n is a positive integer or zero; y is zero or a positive integer less than or equal to (2n+ 1); and N is an integer between -20 and +2. These expanded porphyrin-like macrocycles are efficient chelators of divalent and trivalent metal ions. Various metal (e.g., transition, main group, and lanthanide) complexes of the hydroxy-substituted texaphyrin derivatives of the present invention have unusual water solubility and stability. They absorb light strongly in a physiologically important region (i.e. 690-880 nm). They have enhanced relaxivity and therefore are useful in magnetic resonance imaging. They form long-lived triplet states in high yield and act as photosensitizers for the generation of singlet oxygen. Thus, they are useful for inactivation or destruction of human immunodeficiency virus (HIV-1), mononuclear or other cells infected with such virus as well as tumor cells. They are water soluble, yet they retain sufficient lipophilicity so as to have greater affinity for lipid rich areas such as atheroma and tumors. They may be used for magnetic resonance imaging followed by photodynamic tumor therapy in the treatment of atheroma and tumors. These properties, coupled with their high chemical stability and appreciable solubility in water, add to their usefulness.

Method and apparatus for multiple-stage and recycle wet oxidation

Abstract: An organic or inorganic feed compound can be treated in two or more zones to progressively oxidize the compound. The first zone oxidizes the compound to an intermediate product which includes a first intermediate compound which is intermediate the feed compound and end product. The second zone further oxidizes the intermediate product to an end product or a second intermediate compound which is intermediate the first intermediate compound and an end product. One or both zones may operate catalytically and/or at supercritical conditions for water to oxidize the compounds.

Inhibition of nitric oxide-mediated hypotension and septic shock with iron-containing hemoprotein

Abstract: The invention is directed to a method for the prophylaxis or treatment of an animal for deleterious physiological effects such as systemic hypotension caused by nitric oxide production induced by a biological response modifier. Examples of such biological response modifiers include but are not limited to a cytokine and an endotoxin. The invention is also directed to a method for the treatment of septic shock.

Three-Phase Gas/Oil/Brine Relative Permeabilities Measured Under CO2 Flooding Conditions

Abstract: Steady-state three-phase gas/oil/brine relative permeabilities were measured in a carbonate core under CO 2 flooding conditions. Results show that the relative permeability of each phase depends only on the saturation of that phase instead of on two saturations, as many previous studies have concluded. All previously reported gas/oil/brine relative permeability studies have been conducted with low-pressure N 2 gas or air. In this work, CO 2 gas, oil, and brine were injected into a carbonate core at 71°C and 9.65 MPa so that the phase behavior and flow would be similar to reservoir conditions. Results show that significant differences exist between the three-phase gas/oil/brine relative permeabilities measured when the gas is CO 2 and those measured when the gas was N 2

Nanophase diamond films

Abstract: Films of nanometer-scale nodules of diamond-bonded carbon structures are disclosed. Such films may be used, for example, to coat objects to improve their resistance to wear. Moreover, because the nanophase diamond films of the present invention are of optical quality, they may be used to coat optical lenses and the like. The nanophase diamond films of the present invention have diamond-like properties, indicating a preponderance of sp3 bonds within the nodules and a substantial absence of hydrogen and graphite within the nodules. If desired, the nanophase diamond films disclosed herein may be created to have a hardness exceeding that of natural diamond, depending on the quantity of graphite left in the voids between the nodules. The nanophase diamond films of the present invention are also characterized by a low coefficient of friction, by low average internal stress, and by an optical quality capable of providing a visual appearance of Newton's rings of interference.

Combined perfusion and oxygenation organ preservation apparatus

Abstract: A method and apparatus is provided for long-term extracorporeal preservation of living tissue. A tissue preservation device including a gas permeable membrane and perfusate allows oxygenation of the living tissue. The gas permeable membrane allows gas from a cyclically pumped source to permeate and expand the membrane, simultaneously oxygenating the perfusate and pumping the oxygen-enriched perfusate through the tissue. Simply constructed of a few basic components, the tissue preservation device is capable of operating in many physical orientations, and requires no electrical power for operation. Also provided is an apparatus for cooling and transporting the tissue preservation device.

Low toxicity interleukin-2 analogues for use in immunotherapy

Abstract: The properties of two recombinant human IL-2 analogues with mutations at Arginine 38 (← Alanine) and Phenylalanine 42 (← Lysine) were analyzed and compared to those of native IL-2. These analogues were found to maintain their ability to bind to the intermediate IL-2 receptor, p75, while binding only minimally to the high affinity p55 + p75 receptor complex. The analogues also maintained the ability to stimulate peripheral blood mononuclear cells to generate lymphokine activated killing (LAK). However, IL-1β and TNF-α secretions were significantly reduced in response to the analogues, as compared to the native IL-2 molecule. These analogues are therefore potentially valuable low-toxicity alternatives to IL-2 in human immunotherapy and adoptive immunotherapy treatment strategies.

Methods of using steroid-polyanionic polymer-based conjugated targeted to vascular endothelial cells

Abstract: This invention discloses new targeted conjugates for the delivery of a compound, and particularly, a steroid, to vascular endothelial cells. The conjugates comprise two components, preferably linked by a selectively-hydrolyzable bond, such as an acid-labile bond or enzyme-sensitive bond. The first component, a polyanionic polymer, and preferably, a polysulphated polymer such as a heparin-derivative, specifically directs the conjugate to vascular endothelial cells. The second component is a selected agent, such as a steroid, which exerts a specific effect on the target cell following its release. In particular, the present invention provides novel conjugated angiogenesis inhibitors, for use in the treatment of pathogenic conditions including cancer, arthritis, and diabetic blindness. An inhibitor comprising a heparin derivative and the anti-angiogenic steroid, cortisol, is herein shown to be markedly acid-labile, to suppress DNA synthesis and cell migration in human umbilical vein endothelial cells, to retard or abolish (depending pending on the route of injection) the vascularization of sponges in vivo and to retard lung tumor growth in mice by 65%. No adverse effects of the conjugate were detected, and equivalent treatments with a mixture of heparin plus cortisol were significantly less effective in all cases.