Showing papers by "University of Nevada, Reno published in 1977"
TL;DR: The data point to a strong need for testing of chemicals for genetic toxicology; particular attention must be given to the subject of co-mutagenicity.
Abstract: Mitomycin C (MMC), actinomycins (ACMs), daunomycin (DNM) and adriamycin (ADR) are antineoplastic, antibiotics, with the anthracyclines (DNM and ADR) being more promising that the others. All these chemicals interact with DNA. MMC brings about cross-linking of the DNA strands and acts as mono-, as well as, bifunctional alkylating agent. The other three intercalate with the DNA molecule. ACMs, especially ACM-D, inhibits RNA synthesis preferentially and discriminates between different species of RNA. At high concentrations, DNA, RNA and protein synthesis are all inhibited by any of these antibiotics. The agents effect the cell cycle traverse at various stages; MMC being most unspecific of all. Mitotic cells at post-G2 stages are the least effected by any of these chemicals. All these chemicals induce chromosome aberrations of chromatid type. The anthracyclines, in addition, produce chromosome-type aberrations perhaps by affecting the single stranded G1 chromosome. Rejoining occurs, but MMC creates a high frequency of quadriradial configurations by utilizing the analogous nucleotide sequences in the repetitive DNA. At other points, it mostly creates free fragments. The mechanisms of action appear to be different for induction of chromosome aberrations by MMC, ACT and the anthracyclines. Both in vitro and in vivo aberration induction has been reported. The associated phenomenon of sister chromatid exchanges is strongly potentiated by these agents. MMC has been a known mutagen in both akaryotes and eukaryotes, and it also increases the frequency of meiotic recombination. ACM-D does not appear to strongly effect these phenomena while sufficient data with the anthracyclines are not available, and perhaps, will turn out to be generally negative. MMC and ACM-D also induced somatic recombination and somatic mosaicism; the former is a potent recombinogen. Correlation between genetic effect and the information available on the binding of ACM-D to chromatin is discussed and some space has been allocated to the discussion of resistance and cross resistance induced by the four chemicals. The data point to a strong need for testing of chemicals for genetic toxicology; particular attention must be given to the subject of co-mutagenicity.
106 citations
69 citations
TL;DR: A summary of what appear to be the important recent developments in bilirubin photochemistry through 1976 is attempted.
Abstract: The increasing interest in and importance of bilirubin photochemistry have been stimulated largely by its relevance to the widely employed phototherapy for neonatal unconjugated hyperbilirubinemia. Symposia proceedings are still among the primary sources of broad overviews of this phototherapy field. Within these published proceedings and in a few other places one may locate summarizing articles on aspects of bilirubin photochemistry (Ostrow, 1972a, b; Ostrow rt ul., 1974, 1976; McDonagh, 1974, 1975a, b., 1976b; Lightner, 1974a, b ; McDonagh and Palma, 1976). In this review. no attempt will be made to render an exhaustive account of the field. Rather, a summary of what appear to be the important recent developments through 1976 will be attempted.
65 citations
TL;DR: In this article, an extension of previous process models of conversion, based on research on the Jesus movement, is presented. The detailed examination of "predispositions" for conversion and the discussion of the importance of affective ties in the conversion process are of particular interest.
Abstract: This paper is an extension of previous process models of conversion, based on research on the Jesus movement. The detailed examination of "predispositions" for conversion and the discussion of the importance of affective ties in the conversion process are of particular interest.
61 citations
TL;DR: The effects of different arrangements of furniture on the behavior of a group of hospitalized geriatric patients were studied and only talking changed systematically across all experimental conditions.
53 citations
TL;DR: In this paper, a bidirectional transfer procedure was used to transfer a rat trained on a successive discrimination problem to a simultaneous discrimination problem, where the transfer problems were either compatible or incompatible with the response mode present during training.
Abstract: Modes of responding in simultaneous and successive discrimination problems were investigated using a bidirectional transfer procedure. Rats receiving training on a simultaneous discrimination problem were transferred to successive discriminations. Rats trained on a successive problem were transferred to simultaneous problems. The transfer problems were either compatible or incompatible with the response mode present during training. The results suggest that a single response mode may underlie the solution of both simultaneous and successive discrimination problem.
45 citations
TL;DR: The structure of 5′-oxo-3′,4,4′-triethyl-3,5-dimethyl-1′,5′-dihydro[2.2′]-dipyrromethene 1, a model for bilirubin, has been determined from three dimensional counter data as discussed by the authors.
44 citations
39 citations
TL;DR: In this paper, the responses of 12 phobic subjects to both phobic and non-phobic thoughts were compared with responses of twelve nonphobic subjects under the same conditions, where the stimulus for both groups of subjects was a self-generated subvocal statement.
35 citations
TL;DR: The regular representation of a restricted direct product of locally compact groups is analyzed in this paper, and examples of such groups for which the regular representations generate various type III infinite tensor product factors are constructed.
34 citations
TL;DR: Lipid and carbohydrate retaining procedures were utilized to retain these components of surfactant in thin section to postulated on morphological evidence an expansion of lamellae in pairs caused by the absorption of a homogeneous, probably carbohydratebased, material of undetermined origin.
Abstract: Lipid and carbohydrate retaining procedures were utilized to retain these components of surfactant in thin section. The origin of tubular myelin surfactant from multilamellar bodies was postulated on morphological evidence to be : an expansion of lamellae in pairs caused by the absorption of a homogeneous, probably carbohydratebased, material of undetermined origin; immediately after the pairs expanded to 438 A, the lamella (lipid bilayer) that was most peripheral in the multilamellar body underwent a molecular rearrangement to form the two cross lipid bilayers; the four lipid bilayers formed a square tubule 413 A of side and 0.16–1.8 μ long. The homogeneous material included within each tubule (the surfactant matrix) did not completely fill the intratubular space, but a centrally located, spherical, 57 A diameter, electron transparent, area was observed. The 413 A square tubules were separated on all sides by a 25 A fatty acid tail area. The phospholipid head areas were 46 A and the surfactant matrix was 132 A between the electron transparent, center area and the phospholipid heads layer. Extraction with several organic solvents was also studied: slight ethanol extraction—alteration of surfactant matrix and loss of transparent, central area. Moderate ethanol extraction—alteration of surfactant matrix to form artifactual tubules and filaments, disruption of lipid bilayers. Severe extraction—ethanol produced loss of integrity of both matrix and lipid bilayers; vinylcyclohexane dioxide or methacrylate produced complete loss of all lipid bilayers, but surfactant matrix retained tubular configuration ; DMP-30 produced complete loss of lipid bilayers, and although most of the matrix material was retained, all areas appeared fractured and randomly oriented.
TL;DR: This paper found that self-regulated internally elicited phobic thoughts produce as much and, at times, greater subjective anxiety, fear, and physiological activity than similar thoughts triggered externally by pictures or verbal statements about phobic objects.
TL;DR: In this article, an approximate expression for the eigenvalues for van der Waals molecules by use of the Lennard-Jones (12-6) potential in the WKB approximation is presented.
TL;DR: Bilirubin is stable in degassed chloroform to irradiation at 440 nm and its quantum yields vary from 10 −2 to 10 −4 with excitation wavelengths of 440, 340 and 280 nm and with the higher quantum yield generally appearing in chloro Form solvent and/or excitation at 280 nm.
TL;DR: Rodent and primate lung surfactant was studied at the ultrastructural level utilizing procedures that retained most of the carbohydrates and lipids in thin section and with three-dimensional understanding, many of the areas previously reported to be homogeneous were determined to actually be oblique cross or longitudinal sections through tubular myelin surfactor.
Abstract: Rodent and primate lung surfactant was studied at the ultrastructural level utilizing procedures that retained most of the carbohydrates and lipids in thin section The three-dimensional aspect of tubular myelin surfactant was observed to be four, lipid bilayer membranes oriented at right angles so that in cross-section it was square In longitudinal section it appeared as two parallel lipid bilayers Inside the tubular myelin was a homogeneous matrix material that completely filled the tubule except for a small, central area A single multilamellar body, after it expanded and rearranged lamellae to form tubular myelin surfactant, still retained its basic morphology so that it was possible to determine the number and orientation of bodies that comprised a given surfactant area This enabled quantification of surfactant by serial sectioning Each transformed multilamellar body was observed to contain from 2 to 13 groups of tubular myelin, oriented at angles within the transformed body With three-dimensional understanding, many of the areas previously reported to be homogeneous were determined to actually be oblique cross or longitudinal sections through tubular myelin surfactant Five distinct layers characterized tubular myelin surfactant: (1) Unexpanded layer—up to 63 recently secreted multilamellar bodies (2) Formation layerpaired lamellae expanding and rearranging to form tubules (3) Mature layer—tubular myelin surfactant (4) Air-surfactant interface layer—usually a single lipid bilayer which was the outermost layer of tubular myelin of from 1 to 12 transformed multilamellar bodies (5) Degraded surfactant layer—lipid bilayer spheres were formed at the interface and degraded in the alveolar space
TL;DR: The demonstrated properties of hyaluronate solutions indicate a system with memory of stress, with most of the transition in the pH range 7.0–7.5, and a large change in optical anisotropy as a function of pH.
Abstract: The flow birefringence and extinction angle over a velocity gradient range of approximately 5–100 sec−1, and the zero shear-viscosity have been obtained from human umbilical cord hyaluronic acid at concentrations of 0.25, 0.125 and 0.0625%, and pHs 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 and constant ionic strength 0.1. The data indicate a large change in optical anisotropy as a function of pH, with most of the transition in the pH range 7.0–7.5, i.e., across the physiological range. The sign of the anisotropy changes between pH 8.0 and 8.5. These results, together with changes in the extinction angle and intrinsic viscosity as a function of pH, suggest a pH-dependent structural change in the system. Due to the abruptness of the transition, as evidenced by the intrinsic viscosity and flow birefringence, it is probable that the structural transition is cooperative. If the data are interpreted in terms of the Rouse-Zimm Gaussian subchain theory, a modification of the model in terms of the Haller-Cerf concept of internal viscosity is required. Thus, the demonstrated properties of hyaluronate solutions indicate a system with memory of stress. Due to the presence of large concentration effects discernible in the extinction angle measurements, hyaluronic acid probably exists as a network in solution. The results are discussed with respect to the mechanoelectrical transducing properties of hyaluronates and stress-dependent changes in ORD already reported.
TL;DR: In contrast to oxodipyrromethenes and bilirubin, benzalpyrrolinones appear not to undergo dye-sensitized photo-oxygenation.
TL;DR: The relationship between phases of the moon and emergency calls to a 24-hr.
Abstract: The relationship between phases of the moon and emergency calls to a 24-hr. telephone crisis intervention service was investigated. The frequency and types of calls were compared for the dates of t...
TL;DR: The dependence of the reaction cross section for all the alkali-methyl iodide reactions on the translational energy in the range E T = 0 −40 kcal/mole has been discussed in an idealized collision model of hard-sphere interaction between colliding particles as mentioned in this paper.
TL;DR: From the results obtained with soybean, the prediction is made that carofur has potentials of bringing about chromosome aberrations.
TL;DR: The results indicate that cytoplasmic lamellar inclusions are not restricted to myomorph rodents, but may well be present in other species, and Thomomys is the only species to date in which a close topographical association develops between the lamellars inclusions and elements of the endoplasmic reticulum.
Abstract: The object of the present study was to examine ovarian oocytes of the sciuromorph rodent. Thomomys townsendii, to determine if they contained cytoplasmic inclusions similar to those reported in myomorph rodents. Our observations indicated the presence of cytoplasmic lamellar inclusions of oocytes of primary, secondary and large vesicular follicles of Thomomys. Small primary oocytes contained numerous cytoplasmic lamellae which appeared as spirals or concentric rings in cross-section. Longitudinal sections suggested the inclusions were arranged as concentric cylindrical sheets of material. Secondary and vesicular oocytes had morphologically similar inclusions, but, in addition, often had a tubular element of the endoplasmic reticulum associated with the core of the lamellae. Tangential sections through the lamellae revealed a crystalline substructure, regardless of the age of the oocyte. Our results indicate that cytoplasmic lamellar inclusions are not restricted to myomorph rodents, but may well be present in other species. The lamellar inclusions are three-dimensionally most similar in structure to those described in the hamster, but several fine structural differences exist even between these species. Thomomys is the only species to date in which a close topographical association develops between the lamellar inclusions and elements of the endoplasmic reticulum. Since the lamellae-endoplasmic reticulum association was not observed in the youngest oocytes examined, it is unlikely the endoplasmic reticulum is involved in synthesis of the lamellae, but it may, nonetheless, be metabolically related to the lamellae.
TL;DR: In this article, short synthetic procedures have been developed to produce gram quantities of 4,5-dimethyl-3-ethyl-5-hydroxy-3pyrrolin-2-one and 3,5dimethyl 4-ethyl 5-hydroxypyrrole-3 pyrrobin-2.1 (1) factors associated with psychiatric and prophyric disorders.
TL;DR: In this paper, the authors parlay some familiar ideas concerning the description-relativity of explanation contexts into explanation contexts, and parlay them into a description-based explanation of historical and lawful explanations.
Abstract: Recent work in archaeology once again raises basic questions concerning historical and lawful explanation. Covering law theorists, including the leaders of the ’new archeology’, have considered singular causal explanation to be nothing more than a poor substitute for explanation by subsumption under covering laws. In this paper I parlay some familiar ideas concerning the description-relativity of explanation contexts into
TL;DR: In this article, the vibrational energy levels for the van der Waals bond of argon-hydrogen halide (Ar…XH) molecules were calculated by use of the WKB method with available potential parameters for the Lennard-Jones (12-6) function.
TL;DR: A basic and fundamental structure was found to be common to all casts studied, and consisted of a fibrillar protein meshwork, and Hyaline casts were composed entirely of this complex proteinaceous material.
Abstract: A method for the scanning electron microscopic (SEM) study of elements contained in the urinary sediment is described. Abnormal urinary sediments were obtained from patients having a wide variety of intrinsic renal diseases as well as from “normals.” The sediments were initially observed using ordinary light, phase and interference microscopy. For study using the scanning electron microscope they were then filtered through a membrane filter and fixed with cold phosphate-buffered 3.5 glutaraldehyde. The filters containing urinary sediment were washed, postfixed in 1% osmium tetroxide, dehydrated and critical-point dried using carbon dioxide, then mounted and sputter-coated with gold–palladium for study using scanning electron microscopy. Preliminary data have indicated numerous, previously undescribed, ultramicroscopic peculiarities of cast structure. A basic and fundamental structure was found to be common to all casts studied, and consisted of a fibrillar protein meshwork. Hyaline casts were composed entirely of this complex proteinaceous material. The same structural material was present in cellular and waxy casts. Blood and epithelial cells were found to be closely adherent to the fibrillar cast matrix in cellular casts. In many instances they were attached by means of encompassing fibrils, in contrast to the time-honored theory of their incorporation within the matrix during cast formation.
TL;DR: The diffusion coefficient for Fe in Y from Mossbauer experiments is several orders of magnitude lower than from bulk diffusion measurements as mentioned in this paper, which can be explained by a combination substitution-interstitial diffusion mechanism.
TL;DR: In this paper, an approximate solution of the time-dependent Schrodinger equation is developed for vibration-vibration energy transfer in a collinear collision of two diatomic molecules.
TL;DR: An interesting phenomenon of "centromeric association" was observed in the bone marrow cells of mice treated with carofur, where the centromeres of the acrocentric chromosomes were oriented towards each other in groups of 2's or more.
Abstract: Summary Chinese hamster cells (line V-79) and human leukocytes in vitro and mice of the CBA strain were treated with carofur (also called nifurprazinum), an antibacterial agent of pharmaceutical importance. At concentrations as low as 20 ppm, the in vitro treatments of cells of Chinese hamster and human lymphocytes expressed chromosome aberrations, almost exclusively of deletion type. This effect resembles that of fluorodeoxyuridine but may not necessarily reflect the same basic mechanism involved. When Chinese hamster cells were treated with 5 ppm or more of carofur for 24 h, a 3-fold increase in the frequency of somatic sister chromatid exchanges was observed. An interesting phenomenon of “centromeric association” was observed in the bone marrow cells of mice treated with carofur, where the centromeres of the acrocentric chromosomes were oriented towards each other in groups of 2's or more.
TL;DR: The assessment device showed significant concurrent validity, although the evidence for construct validity was minimal, and the behavioral-analytic model of competence has both theoretical and practical advantages in constructing other assessment devices for the elderly.
Abstract: This study developed a behavioral measure of assertiveness for older adults The behavioral assessment device was developed by use of procedures outlined by Goldfried and D'Zurilla (1969) and Price and Bouffard (1974) Four assertion-appropriate situations for older adults were developed The situations were administered to 33 Ss Their responses were scored two ways, for overall assertion and content assertion Generalizability of the device was examined Reliability of judges' ratings (for assertion and content) was high, as was test-retest reliability Assertion was shown to be situation-specific since estimated individual by situation uninerse variance was relatively hight The assessment device showed significant concurrent validity, although the evidence for construct validity was minimal Despite the rigorousness of the methods involved, the behavioral-analytic model of competence (Goldfried & D'Zurilla, 1969) has both theoretical and practical advantages in constructing other assessment devices for the elderly