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Medial Medulla Networks in Culture: a Multichannel Electrophysiologic and Pharmacological Study

Description: Spontaneously active primary cultures obtained from dissociated embryonic medial medulla tissue were grown on microelectrode arrays for investigating burst patterns and pharmacological responses of respiratory-related neurons. Multichannel burst rates and spike production were used as primary variables for analysis. Pacemaker-like neurons were identified by continued spiking under low Ca++/high Mg++conditions. The number of pacemakers increased with time under synaptic blocking medium. Sensitivity to CO2 levels was found in some neurons. Acetylcholine changed activity in a complex fashion. Curare, atropine and gallamine modified ACh effects. Eserine alone was ineffective, but potentiated ACh-induced responses. Norepinephrine caused channel-specific increases or decreases, whereas dopamine and serotonin had little effect at 30 μM. GABA and glycine stopped most spiking at 70 μM. Developmental changes in glycine sensitivity (increasing with age) were also observed. It is concluded that pacemaker and chemosensitive neurons develop in medial medulla cultures, and that these cultures are pharmacologically histiotypic.
Date: August 1998
Creator: Keefer, Edward W. (Edward Wesley)
Partner: UNT Libraries

Comparative Morphology of Sensilla Styloconica on the Proboscis of North American Nymphalidae and Other Selected Taxa: Systematic and Ecological Considerations.

Description: Sensilla styloconica on the proboscis of 107 species of North American and tropical butterflies were comparatively studied using the scanning electron microscope. Focus was on 76 species of North American Nymphalidae representing 45 genera and 11 subfamilies. Nomenclature for generalized and specific types of nymphalid sensilla is proposed. Written descriptions and micrographs are presented for each species studied. Morphological features were generally consistent for all or most species within genera and sometimes within subfamilies, with specified exceptions. Statistical analysis revealed significant differences for six of eight variables tested between two distinct feeding guilds of North American Nymphalidae. Average number, density, extent of proboscis coverage with sensilla, their total length, and shoulder spine length were all significantly greater in the non-nectar feeding guild than in nectar feeders, and may indicate adaptation for greater efficiency in feeding on flat surfaces. The greater frequency of apical shoulder spines in non-nectar feeders may represent adaptation for protection of sensory pegs from mechanical abrasion during feeding, or for anchoring the flexible proboscis tip to the surface. Correlation analysis revealed 9 out of 28 positive correlations in nectar feeders and 5 out of 28 in non-nectar feeders. Results of preliminary cladistic analysis were not considered to be meaningfully robust due to few available characters. The stylar characters identified in this study should be more useful in future analyses when included with characters from other lines of evidence. The presence of sensilla styloconica in all subfamilies of Nymphalidae, except Danainae, largely supports Ehrlich's (1958) higher classification concept for the family. The presence of less conspicuous sensilla in the Danainae, and other characteristics are presented as further evidence that they should be reconsidered for full family status. Sensilla styloconica in nymphalid butterflies appear to function as extensions that provide greater sensory reach during feeding. The role of these ...
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Date: December 2001
Creator: Petr, Daniel
Partner: UNT Libraries

Social Interest and the Communications Organ Score in Human Figure Drawings

Description: The relationship between social interest and personal adjustment described by Adler seems to imply that the CO score is positively correlated with personal adjustment. If the CO score in a human figure drawing indicates the degree of social interest manifested by an individual, it is reasoned that the CO score will measure that individual's adjustment level.
Date: August 1970
Creator: Long, Wesley L.
Partner: UNT Libraries

Neural Grafting: Repairing the Brain and Spinal Cord

Description: This special report, the second of our neuroscience series, discusses the field of neural grafting into the brain and spinal cord to treat neurological disorders. It describes the technology of neural grafting, the neurological conditions that it may be used to treat, and the patient populations that are affected. Also, the legal and ethical issues raised by the development of neural grafting techniques are discussed. The report includes a range of options for congressional action related to the Federal funding of transplantation research using human fetal tissue, the adequacy of existing Federal laws and regulations regarding the use of human fetal tissue, and the role of the Federal Government in guiding the development and promoting the safety and efficacy of neural grafting procedures.
Date: October 1990
Creator: United States. Congress. Office of Technology Assessment.
Partner: UNT Libraries Government Documents Department

CANCELLED EMT and back again: does cellular plasticity fuel neoplastic progression?

Description: Epithelial-mesenchymal transition (EMT) is a cellular transdifferentiation program that facilitates organ morphogenesis and tissue remodeling in physiological processes such as embryonic development and wound healing. However, a similar phenotypic conversion is also detected in fibrotic diseases and neoplasia, in which it is associated with disease progression. EMT in cancer epithelial cells often appears to be an incomplete and bi-directional process. Here we discuss the phenomenon of EMT as it pertains to tumor development, focusing on exceptions to the commonly held rule that EMT promotes invasion and metastasis. We also highlight the role of the Ras-controlled signaling mediators, ERK1, ERK2 and PI3-kinase, as microenvironmental responsive regulators of EMT.
Date: February 24, 2007
Creator: Turley, Eva A.; Veiseh, Mandana; Radisky, Derek C. & Bissell, MinaJ.
Partner: UNT Libraries Government Documents Department

Of extracellular matrix, scaffolds, and signaling: Tissuearchitectureregulates development, homeostasis, and cancer

Description: The microenvironment surrounding cells influences gene expression, such that a cell's behavior is largely determined by its interactions with the extracellular matrix, neighboring cells, and soluble cues released locally or by distant tissues. We describe the essential role of context and organ structure in directing mammary gland development and differentiated function, and in determining response to oncogenic insults including mutations. We expand on the concept of 'dynamic reciprocity' to present an integrated view of development, cancer, and aging, and posit that genes are like piano keys: while essential, it is the context that makes the music.
Date: March 9, 2006
Creator: Nelson, Celeste M. & Bissell, Mina J.
Partner: UNT Libraries Government Documents Department

Extracellular Matrix, Nuclear and Chromatin Structure and Gene Expression in Normal Tissues and Malignant Tumors: A Work in Progress

Description: Almost three decades ago, we presented a model where theextracellular matrix (ECM) was postulated to influence gene expressionand tissue-specificity through the action of ECM receptors and thecytoskeleton. This hypothesis implied that ECM molecules could signal tothe nucleus and that the unit of function in higher organisms was not thecell alone, but the cell plus its microenvironment. We now know that ECMinvokes changes in tissue and organ architecture and that tissue, cell,nuclear, and chromatin structure are changed profoundly as a result ofand during malignant progression. Whereas some evidence has beengenerated for a link between ECM-induced alterations in tissuearchitecture and changes in both nuclear and chromatin organization, themanner by which these changes actively induce or repress gene expressionin normal and malignant cells is a topic in need of further attention.Here, we will discuss some key findings that may provide insights intomechanisms through which ECM could influence gene transcription and howtumor cells acquire the ability to overcome these levels ofcontrol.
Date: August 1, 2006
Creator: Spencer, Virginia A.; Xu, Ren & Bissell, Mina J.
Partner: UNT Libraries Government Documents Department

VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

Description: Reproductive toxicants are a very important class of compounds. They present unique hazards to those of child bearing ages, perform their 'dirty work' using a wide variety of mechanisms on a number of different organs, and are regulatorily important. Because of all of this, properly identifying reproductive toxicants is important, but fraught with difficulty. In this paper we will describe types or reproductive toxicants, their importance, and both mistakes and good practices that people who are not experts in reproductive toxicology may use in their attempts to identify them. Additionally, this paper will focus on chemical reproductive toxicants and will not address biological agents that could affect reproductive toxicity although many principles outlined here could be applied to that endeavor.
Date: May 13, 2008
Creator: Simmons, F
Partner: UNT Libraries Government Documents Department

[King's College Chapel Interior]

Description: Photograph of the interior of the King's College Chapel in Cambridge, England. On the right side, large stained-glass windows arch upwards toward the carved stone ceiling. To the left of the windows, the dark silhouette of the organ is visible.
Date: September 1970
Creator: Gough, Ray
Partner: UNT College of Visual Arts + Design

Biologic response to complex blast waves

Description: Small, bare charges were detonated inside an M59 armored personnel carrier (APC) in an attempt to simulate the complex blast waves generated by the jets from shaped-charge warheads penetrating into armored vehicles. Anesthetized sheep were placed inside the APC at 92- and 122-cm ranges from 57- or 113-g pentolite charges. Pressure-time was measured by pressure transducers either mounted on the animals or free standing at comparable ranges on the opposite side of the vehicle. In general, the waveforms were characterized by an initial shock wave of less than 1-msec duration followed by repeated reflections of decreasing magnitude. No deaths nor lung hemorrhages were observed, but all the animals sustained severe ear injury. Animals subjected to peak overpressures of 1.2 to 2.3 bar from the 113-g explosions also received slight non-auditory blast injuries to the upper respiratory and gastrointestinal tracts; those exposed to peak overpressures of just under 1 bar from the 57-g charges did not. The non-auditory blast injuries inside the APC were more severe than those sustained by sheep at comparable distances from 113-g charges in the open. The results suggested that the biological consequences of a complex wave of the type encountered in this study can be equated approximately to a Friedlander wave with a peak overpressure equal to that of the complex wave and with a total impulse equal to the impulse over the first 2 to 3 msec of the complex wave. 9 refs., 7 figs., 1 tab.
Date: January 1, 1985
Creator: Richmond, D.R.; Yelverton, J.T.; Fletcher, E.R. & Phillips, Y.Y.
Partner: UNT Libraries Government Documents Department

Multipolar corneal-shaping electrode

Description: The disclosure relates to a multipolar probe using radiofrequency energy to reshape the cornea of an eye. The surface of the cornea is flushed continuously with a conductive coolant during operation.
Date: April 30, 1981
Creator: Doss, J.D.
Partner: UNT Libraries Government Documents Department

Radiation dose estimates for radiopharmaceuticals

Description: Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms.
Date: April 1996
Creator: Stabin, M. G.; Stubbs, J. B. & Toohey, R. E.
Partner: UNT Libraries Government Documents Department

BEST: Bilingual environmental science training: Kindergarten level

Description: This booklet is one of a series of bilingual guides to environmental-science learning activities for students to do at home. Lesson objectives, materials required, procedure, vocabulary, and subjects integrated into the lesson are described in English for each lesson. A bilingual glossary, alphabetized by English entries, with Spanish equivalents in both English and Spanish, follows the lesson descriptions, and is itself followed by a bibliography of English-language references. This booklet includes descriptions of six lessons covering the senses of touch and sight, the sense of smell, how to distinguish living and non-living things, cell structures, the skeletal system, and the significance of food groups. 8 figs.
Date: March 1, 1996
Partner: UNT Libraries Government Documents Department

MONOAMINE OXIDASE: RADIOTRACER DEVELOPMENT AND HUMAN STUDIES.

Description: PET is uniquely capable of providing information on biochemical transformations in the living human body. Although most of the studies of monoamine oxidase (MAO) have focused on measurements in the brain, the role of peripheral MAO as a phase 1 enzyme for the metabolism of drugs and xenobiotics is gaining attention (Strolin Benedetti and Tipton, 1998; Castagnoli et al., 1997.). MAO is well suited for this role because its concentration in organs such as kidneys, liver and digestive organs is high sometimes exceeding that in the brain. Knowledge of the distribution of the MAO subtypes within different organs and different cells is important in determining which substrates (and which drugs and xenobiotics) have access to which MAO subtypes. The highly variable subtype distribution with different species makes human studies even more important. In addition, the deleterious side effects of combining MAO inhibitors with other drugs and with foodstuffs makes it important to know the MAO inhibitory potency of different drugs both in the brain and in peripheral organs (Ulus et al., 2000). Clearly PET can play a role in answering these questions, in drug research and development and in discovering some of the factors which contribute to the highly variable MAO levels in different individuals.
Date: September 28, 2000
Creator: Fowler, J. S.; Logan, J.; Volkow, N. D.; Wang, G. J.; MacGregor, R. R. & Ding, Y. S.
Partner: UNT Libraries Government Documents Department

Hydroxylapatite Otologic Implants

Description: A Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corporation (LMER) and Smith and Nephew Richards Inc. of Bartlett, TN, was initiated in March 1997. The original completion date for the Agreement was March 25, 1998. The purpose of this work is to develop and commercialize net shape forming methods for directly creating dense hydroxylapatite (HA) ceramic otologic implants. The project includes three tasks: (1) modification of existing gelcasting formulations to accommodate HA slurries; (2) demonstration of gelcasting to fabricate green HA ceramic components of a size and shape appropriate to otologic implants: and (3) sintering and evaluation of the HA components.
Date: January 1, 2000
Creator: McMillan, A.D.; Lauf, R.J.; Beale, B. & Johnson, R.
Partner: UNT Libraries Government Documents Department

External exposure to radionuclides in air, water, and soil

Description: Federal Guidance Report No. 12 tabulates dose coefficients for external exposure to photons and electrons emitted by radionuclides distributed in air, water, and soil. The dose coefficients are intended for use by Federal Agencies in calculating the dose equivalent to organs and tissues of the body.
Date: May 1, 1996
Creator: Eckerman, K.F. & Ryman, J.C.
Partner: UNT Libraries Government Documents Department

Signal transduction regulating meristem development in Arabidopsis. Final report

Description: Research support by DE-FG02-96ER20227 focused on the CLV loci and their regulation of organ formation at the Arabidopsis shoot meristem. Shoot meristem function is central to plant development as all of the above-ground organs and tissues of the plant are derived post-embryonically from the shoot meristem. At the shoot meristem, stem cells are maintained, and progeny cells undergo a switch toward differentiation and organ formation. The CLV loci, represented by three genes CLV1, CLV2 and CLV3 are key regulators of meristem development. Each of the CLV loci encode a putative receptor-mediated signaling component. When this work began, virtually nothing was known about receptor-mediated signaling in plants. Thus, our goal was to both characterize these genes and the proteins they encode as regulators of meristem development, and to investigate how receptor-mediated signaling might function in plants. Our work lead to several major publications that were significant contributions to understanding this system.
Date: September 10, 2003
Creator: Cark, Steven E.
Partner: UNT Libraries Government Documents Department

Executive Summary-Final Technical Report

Description: The primary goal since inception of this DOE grant award in 1991 to Wellman Laboratories of Photomedicine, Harvard Medical School, Massachusetts General Hospital, has been to support competitive research fellowships aimed at solving important medical problems, contributing significant new knowledge and/or technology. This approach was taken according to the original intent of the DOE program, to foster excellent centers for research and development of lasers and optics in medicine. Laser photomedicine broadly encompasses optical therapy and optical diagnostics, within any organ system. The research supported clearly reflects this breadth and depth.
Date: February 18, 2004
Creator: Anderson, R. R.
Partner: UNT Libraries Government Documents Department