Showing papers by "Case Western Reserve University published in 1987"
01 Apr 1987
2,759 citations
TL;DR: In this article, the authors investigated the relationship between a number of corporate characteristics and specific types of social responsibility disclosures, based on an extensive sample of U.S. corporate annual reports.
Abstract: Since the mid-1970s a number of studies have investigated the nature and frequency of corporate social responsibility disclosures, their patterns and trends, and their general relationships to corporate size and profitability. This study seeks to extend our knowledge of the relationship between a number of corporate characteristics and specific types of social responsibility disclosures, based on an extensive sample of U.S. corporate annual reports. Corporate size and industry category are found to correlate with certain types of disclosures while the existence of a corporate social responsibility committee appears to correlate with one particular type of disclosure.
1,138 citations
TL;DR: It is proposed that the ubiquitin-mediated degradative pathway may be effective in removing fibrillar structures in Alzheimer disease brain, but covalently associated with the insoluble neurofibrillary material of NFT and SP.
Abstract: Neurofibrillary tangles (NFT) and neurites associated with senile plaques (SP) in Alzheimer disease-affected brain tissues were specifically immunostained with affinity-purified antibody preparations directed against ubiquitin. In addition, a class of neurites seen in brain regions containing NFT and SP were also specifically stained. Cross-reactivity of the ubiquitin antisera for tau protein, neurofilament proteins, and high molecular weight microtubule-associated proteins (MAPs) were ruled out by (i) the inability of the ubiquitin antisera to stain these proteins in immunoblotting experiments and (ii) the inability of tau, neurofilament, and MAP preparations, when preincubated with the ubiquitin antisera, to inhibit the selective neurofibrillar staining observed. Our results are consistent with the suggestion that ubiquitin is covalently associated with the insoluble neurofibrillary material of NFT and SP. We propose that the ubiquitin-mediated degradative pathway may be ineffective in removing these fibrillar structures in Alzheimer disease brain.
572 citations
TL;DR: It is predicted that foot-and-mouth disease virus protein 2C binds GTP and, by analogy, thatprotein 2C from several related viruses (polio, rhino, encephalomyocarditis, and cowpea mosaic) will bind a nucleotide as part of its biologic activity.
Abstract: A sequence comparison of nine functionally different GTP-binding protein families has yielded further information on the general characterization of the conservation and importance of amino acid sequences in the GTP-binding domain, including a consensus sequence composed of three consensus elements GXXXXGK, DXXG, and NKXD with consensus spacings of either 40-80 or approximately equal to 130-170 amino acid residues between the first and second elements and approximately 40-80 amino acid residues between the second and third sequence elements; the sequence NKXW in place of NKXD in the sequence element responsible for base specificity allows the use of ITP as well as GTP; dGTP can be used with essentially the same efficiency as GTP; signal transducing proteins and enzymes have been identified in the nine families; and family conservations allow the identification of the most probable consensus sequence element when more than one is present. Employing these features we have screened the protein sequence data base of the Protein Identification Resource and have identified only known GTP-binding proteins with the exception of protein 2C from foot-and-mouth disease virus as matching the consensus sequence. Based on this finding we predict that foot-and-mouth disease virus protein 2C binds GTP and, by analogy, that protein 2C from several related viruses (polio, rhino, encephalomyocarditis, and cowpea mosaic) will bind a nucleotide as part of its biologic activity.
570 citations
TL;DR: The clinical outcome of bone grafting procedures depends on many factors, including type and fixation of the bone graft as well as the site and status of the host bed, which determines the success of these procedures.
Abstract: The increasing demand for bone graft material in revision arthroplasty and tumour reconstruction requires a thorough understanding of the natural history and biology of autografts and processed allografts. A number of reports in the literature indicate that bone grafts may have a failure rate approaching 25% (Mankin et al. 1987). The failure is a result of inadequate revascularisation and mineralisation of the bone graft. Immunological rejection of bone allografts still remains an important consideration in the failure of these grafts. The natural history of bone grafts has been defined from extensive laboratory studies and clinical experience (Goldberg and Stevenson 1987). This chapter will review the present knowledge in this field.
533 citations
TL;DR: In this article, two possible mechanisms for the formation of alkyl carbonates are discussed: nucleophilic reaction of propylene carbonate with basic species such as OH−, and one-electron reduction by lithium metal, followed by free radical termination reactions.
Abstract: FTIR, IR, and XPS have been used to study the films formed on lithium in propylene carbonate solutions of ,, and . Over a range of conditions, the main components detected in the initial surface films were lithium alkyl carbonates . Another alkyl carbonate solvent, diethyl carbonate, was found to react with lithium to form lithium ethyl carbonate, . In addition to solvent reduction, XPS measurements gave indication of salt reduction reactions. , , and were reduced by lithium to form halide ions, which were detected on the lithium surface. Two possible mechanisms for the formation of alkyl carbonates are discussed. One is the nucleophilic reaction of propylene carbonate with basic species such as OH−, while the other involves one‐electron reduction of propylene carbonate by lithium metal, followed by free radical termination reactions. When high concentrations of water were present, lithium carbonate was formed by further reaction of the alkyl carbonates with water. On lithium surfaces without a mechanically stable surface film, such as those of lithium/mercury amalgams, the reduction reaction is believed to proceed by an overall two‐electron process, and the primary product is lithium carbonate.
532 citations
TL;DR: All chemicals were tested under code using a preincubation modification of the Salmonella/microsome test in the absence of exogenous metabolic activation and in the presence of liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters.
Abstract: The results and data from the testing of 255 chemicals for mutagenicity in Salmonella are presented. All chemicals were tested under code using a preincubation modification of the Salmonella/microsome test in the absence of exogenous metabolic activation and in the presence of liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters.
450 citations
TL;DR: Astrocytes appear to stop axons from regenerating in the mammalian spinal cord by activating the physiological stop pathway that is built into the axon and that normally operates when axons form stable terminals on target cells.
Abstract: Regenerating sensory axons in the dorsal roots of adult mammals are stopped at the junction between the root and spinal cord by reactive astrocytes. Do these cells stop axonal elongation by activating the physiological mechanisms that normally operate to stop axons during development, or do they physically obstruct the elongating axons? In order to distinguish these possibilities, the cytology of the axon tips of regenerating axons that were stopped by astrocytes was compared with the axon tips that were physically obstructed at a cul-de-sac produced by ligating a peripheral nerve. The terminals of the physically obstructed axon tips were distended with neurofilaments and other axonally transported structures that had accumulated when the axons stopped elongating. By contrast, neurofilaments did not accumulate in the tips of regenerating axons that were stopped by spinal cord astrocytes at the dorsal root transitional zone. These axo-glial terminals resembled the terminals that axons make on target neurons during normal development. On the basis of these observations, astrocytes appear to stop axons from regenerating in the mammalian spinal cord by activating the physiological stop pathway that is built into the axon and that normally operates when axons form stable terminals on target cells.
422 citations
TL;DR: The results show influence of internal muscle dynamics on muscle control histories vis a vis muscle forces and illustrate the strong sensitivity of the results to the differentiation procedure used in the static optimization approach.
358 citations
351 citations
TL;DR: In this paper, a new method was used to produce uniaxially aligned small single crystals of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-//sub delta.
Abstract: A new method has been used to produce uniaxially aligned small single crystals of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-//sub delta/. The superconducting critical current deduced from magnetization data is strongly field dependent and highly anisotropic. In the basal plane at T = 4.2 K we estimate that the critical current at zero field is in excess of 10/sup 7/ A/cm/sup 2/.
TL;DR: The observation that urine DAF has C4bp-(or factor H-)like activity shows that it could inhibit the fluid phase activation of the cascade, and the function of DAF in body fluids is unknown.
Abstract: Decay-accelerating factor (DAF) is a 70 kD membrane regulatory protein that prevents the activation of autologous complement on cell surfaces. Using immunohistochemical methods and a radioimmunometric assay based on mAbs to DAF, we found large amounts of membrane-associated DAF antigen on the epithelial surface of cornea, conjunctiva, oral and gastrointestinal mucosa, exocrine glands, renal tubules, ureter and bladder, cervical and uterine mucosa, and pleural, pericardial and synovial serosa. Additionally, we detected soluble DAF antigen in plasma, tears, saliva, and urine, as well as in synovial and cerebrospinal fluids. While plasma, tear, and saliva DAF are larger than erythrocyte (Ehu) membrane DAF by Western blot analysis, urine DAF is slightly smaller (67,000) in Mr. Unlike purified Ehu DAF, however, urine DAF is unable to incorporate into the membrane of red cells. Although its inhibitory activity on the complement enzyme C3-convertase is lower than that of Ehu DAF, it is comparable to that of serum C4 binding protein (C4bp). Biosynthetic studies using cultured foreskin epithelium and Hela cells disclosed DAF levels (approximately 2 X 10(5) molecules/cell) exceeding those on blood cells. In addition, these studies revealed the synthesis of two DAF species, one with apparent Mr corresponding to that of epithelial cell membrane DAF and the other to urine DAF, suggesting that the urine DAF variant arises from adjacent epithelium. The function of DAF in body fluids is unknown, but the observation that urine DAF has C4bp-(or factor H-)like activity shows that it could inhibit the fluid phase activation of the cascade.
TL;DR: In this paper, a detailed failure criterion for ZrO2-toughened ceramics is presented, after which microstructural evolution in MgO-partially-stabilized Mg-PSZ is reviewed.
Abstract: Transformation toughening in ZrO2-containing ceramics is discussed. Specifically, microstuctures of the three distinct types of ZrO2-toughened ceramics are presented, after which microstructural evolution in MgO-partially-stabilized ZrO2 Mg-PSZ) is reviewed. The mechanical properties of such transformation-toughened ceramics are dominated by “resistance-curve” (R-curve) behavior, wherein the crack resistance increases during the course of crack propagation. Ceramics subject to R-curve behavior require a more detailed failure criterion than those subject to the usual linear elastic fracture mechanics criterion involving a critical stress intensity factor, KIC.R-curve-controlled fracture in ceramics provides a degree of very desirable flaw insensitivity, but can lead to counterintuitive relationships concerning strength, toughness, and initial flaw size. Examples of R curves of Mg-PSZ with different thermal histories are given.
TL;DR: Through the use of semicustom integrated circuit technology, an implantable muscle stimulator has been developed that is small, lightweight, has low power consumption, and is intended for permanent usage.
Abstract: Through the use of semicustom integrated circuit technology, an implantable muscle stimulator has been developed. The unit is small, lightweight, has low power consumption, and is intended for permanent usage. The stimulator circuitry is externally controlled and powered by a single encoded radio frequency carrier. Up to eight independently controlled stimulus output channels are provided, with output channel selection, stimulus pulse width, and stimulus pulse frequency under external control. A constant current biphasic stimulus pulse is used, in which the stimulus current amplitude can be preset by a single resistor value. The stimulator circuitry has been implemented in thick film hybrid form, and has undergone laboratory evaluation for 48 months.
TL;DR: In this paper, the authors examine the linkage between diversity and performance using a two-dimensional conceptualization of diversity in business enterprises and propose methods for measuring diversification in enterprises using a variety of metrics.
Abstract: The article discusses a study which examines the linkage between diversity and performance using a two-dimensional conceptualization of diversity in business enterprises. Methods for measuring dive...
TL;DR: Uromodulin (Tamm-Horsfall glycoprotein) may function as a unique renal regulatory glycop protein that specifically binds to and regulates the circulating activity of a number of potent cytokines, including IL-1 and TNF.
Abstract: The protein portion of the immunosuppressive glycoprotein uromodulin is identical to the Tamm-Horsfall urinary glycoprotein and is synthesized in the kidney. Evidence that the glycoproteins are the same is based on amino acid sequence identity, immunologic cross-reactivity, and tissue localization to the thick ascending limb of Henle's loop. Nucleic acid sequencing of clones for uromodulin isolated from a complementary DNA bank from human kidney predicts a protein 639 amino acids in length, including a 24--amino acid leader sequence and a cysteine-rich mature protein with eight potential glycosylation sites. Uromodulin and preparations of Tamm-Horsfall glycoprotein bind to recombinant murine interleukin-1 (rIL-1) and human rIL-1 alpha, rIL-1 beta, and recombinant tumor necrosis factor (rTNF). Uromodulin isolated from urine of pregnant women by lectin adherence is more immunosuppressive than material isolated by the original salt-precipitation protocol of Tamm and Horsfall. Immunohistologic studies demonstrate that rIL-1 and rTNF bind to the same area of the human kidney that binds to antiserum specific for uromodulin. Thus, uromodulin (Tamm-Horsfall glycoprotein) may function as a unique renal regulatory glycoprotein that specifically binds to and regulates the circulating activity of a number of potent cytokines, including IL-1 and TNF.
TL;DR: Results indicate that portions of the DAF gene may have evolved from a DNA element common to the above proteins, that DAF cDNA predicts a COOH-terminal anchoring polypeptide, and that distinct species of DAF message are elaborated in cells.
Abstract: cDNAs encoding the complement decay-accelerating factor (DAF) were isolated from HeLa and differentiated HL-60 lambda gt cDNA libraries by screening with a codon preference oligonucleotide corresponding to DAF NH2-terminal amino acids 3-14. The composite cDNA sequence showed a 347-amino acid protein preceded by an NH2-terminal leader peptide sequence. The translated sequence beginning at the DAF NH2 terminus encodes four contiguous approximately equal to 61-amino acid long repetitive units of internal homology. The repetitive regions contain four conserved cysteines, one proline, one glycine, one glycine/alanine, four leucines/isoleucines/valines, one serine, three tyrosines/phenylalanines, and one tryptophan and show striking homology to similar regions previously identified in factor B, C2, C4 binding protein, factor H, C1r, factor XIII, interleukin 2 receptor, and serum beta 2-glycoprotein I. The consensus repeats are attached to a 70-amino acid long segment rich in serine and threonine (potential O-glycosylation sites), which is in turn followed by a stretch of hydrophobic amino acids. RNA blot analysis of HeLa and HL-60 RNA revealed three DAF mRNA species of 3.1, 2.7, and 2.0 kilobases. The results indicate that portions of the DAF gene may have evolved from a DNA element common to the above proteins, that DAF cDNA predicts a COOH-terminal anchoring polypeptide, and that distinct species of DAF message are elaborated in cells.
TL;DR: Findings suggest that meeting patients' requests increased their satisfaction with the encounter, and at least 19% of the variance in patient satisfaction could be attributed to request fulfillment.
TL;DR: This short DNA sequence serves as a cAMP response element and also functions independently of other promoter-regulatory elements located in the 5' flanking sequence of the alpha-subunit gene.
Abstract: cAMP regulates transcription of the gene encoding the alpha-subunit of human chorionic gonadotropin (hCG) in choriocarcinoma cells (BeWo). To define the sequences required for regulation by cAMP, we inserted fragments from the 5' flanking region of the alpha-subunit gene into a test vector containing the simian virus 40 early promoter (devoid of its enhancer) linked to the bacterial chloramphenicol acetyltransferase (CAT) gene. Results from transient expression assays in BeWo cells indicated that a 1500-base-pair (bp) fragment conferred cAMP responsiveness on the CAT gene regardless of position or orientation of the insert relative to the viral promoter. A subfragment extending from position -169 to position -100 had the same effect on cAMP-induced expression. Furthermore, the entire stimulatory effect could be achieved with an 18-bp synthetic oligodeoxynucleotide corresponding to a direct repeat between positions -146 and -111. In the absence of cAMP, the alpha-subunit 5' flanking sequence also enhanced transcription from the simian virus 40 early promoter. We localized this enhancer activity to the same -169/-100 fragment containing the cAMP response element. The 18-bp element alone, however, had no effect on basal expression. Thus, this short DNA sequence serves as a cAMP response element and also functions independently of other promoter-regulatory elements located in the 5' flanking sequence of the alpha-subunit gene.
TL;DR: This paper extends the relational algebra with three new operators, namely, pack, unpack, and aggregation-by-template, to manipulate set-valued attributes and to utilize aggregate functions.
Abstract: In commercial network database management systems, set-valued fields and aggregate functions are commonly supported. However, the relational database model, as defined by Codd, does not include set-valued attributes or aggregate functions. Recently, Klug extended the relational model by incorporating aggregate functions and by defining relational algebra and calculus languages.In this paper, relational algebra and relational calculus database query languages (as defined by Klug) are extended to manipulate set-valued attributes and to utilize aggregate functions. The expressive power of the extended languages is shown to be equivalent. We extend the relational algebra with three new operators, namely, pack, unpack, and aggregation-by-template. The extended languages form a theoretical framework for statistical database query languages.
TL;DR: General, robust modifications of the standard gradient or spin-echo sequences are discussed by using rephasing gradients that force the phase of constant-velocity moving spins to be zero at the echo to lead to a significant reduction in motion artifacts and hence improvement in image quality.
Abstract: Numerous techniques exist for suppressing ghosting artifacts due to respiratory motion on MR images. Although such methods can remove coherent ghosting artifacts, motion during gradient pulses also leads to poor image quality. This is due to phase variations at the echo caused by changes in velocity from one phase-encoding view to the next. The effect becomes severe for long sampling times and long TE values and can lead to low estimates of T2. We discuss general, robust modifications of the standard gradient or spin-echo sequences by using rephasing gradients that force the phase of constant-velocity moving spins to be zero at the echo. These sequences lead to a significant reduction in motion artifacts and hence improvement in image quality. They can be applied to multislice, multiecho, water/fat, and gating schemes as well. Since motion problems are universal, it would appear that these modified sequences should come into common usage for MR imaging.
TL;DR: Study of intubated, intensive care unit patients prospectively by serial examinations of tracheal aspirates for elastin fibers, graded Gram's stains, and quantitative bacterial cultures in conjunction with clinical and radiologic observations in an attempt to develop criteria for the early detection of pulmonary infection.
Abstract: The clinical distinction between bacterial colonization of the tracheobronchial tree and nosocomial pneumonia is difficult, especially in intubated patients We studied 51 intubated, intensive care unit patients prospectively by serial examinations of tracheal aspirates for elastin fibers, graded Gram's stains, and quantitative bacterial cultures in conjunction with clinical and radiologic observations in an attempt to develop criteria for the early detection of pulmonary infection Patients with infection had new or progressive pulmonary infiltrates plus 1 of the following: positive blood culture results, radiographic evidence of cavitation, or histologic evidence of pneumonia, or 2 or more of the following: new fever, new leukocytosis, or grossly purulent tracheal aspirates Twenty-one patients developed infection, 22 remained colonized, and 8 had an uncertain status Infiltrates developed in 34 patients (21 infected, 8 colonized, 5 uncertain status) Gram-negative bacilli were most commonly isolated and were more frequent in infected patients (81 versus 47%, p less than 005); Pseudomonas aeruginosa and Serratia marcescens were most often associated with infection No differences were observed between infected and colonized patients in demographic features, smoking history, underlying disease, previous antibiotic therapy, days in hospital before intubation, preexisting pneumonia upon intubation, or highest temperature or leukocyte count during course By univariate analysis, infected patients had a longer duration of intubation (p less than 005), higher Gram's stain grading for neutrophils (p less than 005) or bacteria (p less than 0005), higher bacterial colony counts (p less than 005), and more frequent detection of elastin fibers in tracheal aspirates (p less than 002)(ABSTRACT TRUNCATED AT 250 WORDS)
Journal Article•
TL;DR: It is proposed that, in the absence of both maternal and zygotic expression of l(1)dsh+, cells from each posterior compartment die and cells from the anterior compartment must rearrange their positional values to generate the segment polarity phenotype.
TL;DR: It is concluded that stimulation of either 5-HT1A or5-HT2 receptors results in an activation of the hypothalamic-pituitary-adrenal axis in the rat.
TL;DR: New rifampin interactions have been described for cyclosporine, ketoconazole, chloramphenicol, beta-blockers, verapamil, and phenytoin that seem to be of clinical significance.
Abstract: Rifampin is a potent inducer of cytochrome P-450 oxidative enzymes. Examples of well-documented, clinically significant interactions include warfarin, oral contraceptives, cyclosporine, glucocorticoids, ketoconazole, theophylline, quinidine, digitoxin, and verapamil. Recent reports have demonstrated clinically relevant interactions with protease inhibitors, zidovudine, delavirdine, itraconazole, nifedipine, midazolam or triazolam, nortriptyline, and doxycycline. To avoid reduced therapeutic response, therapeutic failure, or toxic reactions when rifampin is added to or discontinued from medication regimens, clinicians need to be cognizant of these interactions. Enhanced knowledge of known interactions will continue to develop, including research on induction of specific cytochrome P-450 isoenzymes. New rifampin interactions will be discovered with further investigations. Arch Intern Med. 1997;157:2453-2458
TL;DR: It is suggested that to completely avoid alcohol-related anatomic abnormalities, advice to discontinue drinking or at least to reduce it to a minimal level before conception is clinically appropriate.
TL;DR: Surgical findings agreed with those from MR images in all seven patients who underwent arthroscopy before MR imaging and in ten of the 12 who underwent surgery afterward, suggesting MR imaging is an accurate means of examining the posterior patellar cartilage.
Abstract: Magnetic resonance (MR) images of the posterior patellar hyaline articular cartilage were obtained in 23 subjects to determine if MR imaging could accurately demonstrate the patellar cartilage. Arthroscopy was used as the standard of reference. Three subjects were asymptomatic volunteers. In the remaining 20 who had patellofemoral pain, arthroscopy was performed before MR imaging in seven and afterward in 12; one did not undergo arthroscopy. MR imaging showed focal areas of swelling of the patellar cartilage, focal hypointensity, surface irregularity, areas of thinning, and areas of cartilage loss with exposure of subchondral bone. The surgical findings agreed with those from MR images in all seven patients who underwent arthroscopy before MR imaging and in ten of the 12 who underwent surgery afterward. MR imaging is an accurate means of examining the posterior patellar cartilage and should be considered as an alternative to diagnostic arthroscopy when chondromalacia patellae is suspected.
TL;DR: The effects of the discrete cellular structure on propagation of electrical excitation in cardiac muscle were studied in a one-dimensional fiber model containing a periodic intercalated disk structure and results demonstrate the discontinuous nature of propagation and the importance of the structure in arrhythmogenesis.
Abstract: The effects of the discrete cellular structure on propagation of electrical excitation in cardiac muscle were studied in a one-dimensional fiber model containing a periodic intercalated disk structure. Globally, the macroscopic velocity of propagation follows the behavior associated with propagation in a continuous tissue (except for high values of disk resistance). In addition, the computed spatial extracellular potential along the fiber is a smooth biphasic waveform and does not reflect the underlying discrete cellular structure of the tissue. Other results of the simulations demonstrate the discontinuous nature of propagation and the importance of the structure in arrhythmogenesis. Vmax displays a biphasic behavior as a function of increasing intercalated disk resistance. An initial "paradoxical" increase in Vmax (with a simultaneous decrease in conduction velocity) is followed by a decrease that leads to decremental propagation and conduction block. The time constant of the foot of the action potential (tau foot) increases monotonically with increasing intercalated disk resistance. An increase in the leakage current to extracellular space brings about a significant decrease in the action potential duration and a loss of the plateau. This major effect is accompanied by a relatively smaller decrease in conduction velocity. Collision of two activation wavefronts results in a significant (100%) increase in Vmax and a very small (0.6%) decrease in tau foot.