Showing papers by "Case Western Reserve University published in 1979"
TL;DR: Human aortic medial smooth muscle cells and umbilical vein endothelial cells in culture were exposed to various concentrations of plasma low density (LDL) and high density (HDL) lipoproteins prepared from normolipemic donors in order to assess their effects on cell growth.
513 citations
TL;DR: The blueprint hypothesis is proposed which asserts that inherent in the primitive germinal neuroepithelium and its derivative primitive glia is the pattern of the primary neuronal pathways which is expressed in neurogenesis as formed channels or spaces between the processes of the epithelial cells.
Abstract: In our previous studies on studies on spinal cord regeneration in the adult lizard and the newt, we observed that the radial processes of the regenerating ependyma form between them channels which are subsequently invaded by growing neurites. In the present study we compare embryogenesis of the newt spinal cord with regeneration in the adult. Except for minor differences, we observed that the germinal neuroepithelium of the embryo and larva patterns the longitudinal neural tracts in a similar manner. With these facts in mind we propose the blueprint hypothesis which asserts that inherent in the primitive germinal neuroepithelium and its derivative primitive glia is the pattern of the primary neuronal pathways which is expressed in neurogenesis as formed channels or spaces between the processes of the epithelial cells, the surfaces of which contain trace pathways which the growing neurites follow toward their destination. The trace pathways are envisoned as mechanical-chemical itineraries which the neurities follow according to their individual affinities. The hypothesis is compared to extant theories and the limitations in central nervous regeneration of vertebrates is compared.
481 citations
TL;DR: The book thickness bt(G) of a graph G is defined, its basic properties are delineated, and relations are given with other invariants such as thickness, genus, and chromatic number.
424 citations
407 citations
TL;DR: Clinically, the frequent occurrence of central pontine myelinolysis in a setting of severe metabolic derangement, particularly of the serum sodium, points in the same direction.
Abstract: No coherent theory has been advanced to explain either the particular localization of the myelinolytic lesions of central pontine myelinolysis or their pathogenesis. However, several lines of evidence support the generalization that the centre of the basis pontis has a special susceptibility to a metabolic fault. The constancy of localization of the lesion and its bilateral symmetry are the very attributes that characterize other metabolic (nutritional) disorders, such as the assymmetrical degeneragion of the papillomacular bundles within the optic nerves and tracts in deficiency amblyopia and the specific affection of the paraventricular regions in the Wernicke-Korsakoff syndrome. And clinically, the frequent occurrence of central pontine myelinolysis in a setting of severe metabolic derangement, particularly of the serum sodium, points in the same direction.
372 citations
TL;DR: In this article, microstructural development during aging of supersaturated solid solutions of cubic ZrO, stabilized with MgO, was studied, principally using transmission electron microscopy, and the starting materials were commercial Mg-PSZ, solution-annealed at 1850°C for 4 h.
Abstract: Microstructural development during aging of supersaturated solid solutions of cubic ZrO, stabilized with MgO was studied, principally using transmission electron microscopy. The starting materials were commercial Mg-PSZ, solution-annealed at 1850°C for 4 h. Optimum mechanical properties are obtained at aging temperatures of 1400° to 1500°C, where homogeneous intragranular precipitates of tetragonal ZrO2 form. The best materials are those in which the precipitation reaction is about two-thirds complete and the precipitates have not lost coherency. Under these conditions, the particles do not transform to monoclinic symmetry when cooled to room temperature, except near propagating cracks, where the stress-induced transformation contributes to the high fracture toughness and strengths observed. Aging at lower temperatures causes eutectoid decomposition, as expected from phase-equilibria considerations. Nucleation of the eutectoid reaction product invariably occurs at grain boundaries.
353 citations
TL;DR: In this paper, a system combining traffic sensors and strain gages on highway bridge girders to obtain axle and gross weights is described, and a weight prediction algorithm is derived that filters out the dynamic components of bridge response and obtains the equivalent static axle weights by a least square error minimization.
Abstract: Acquisition of truck axle and gross weight information is necessary for structural and maintenance requirements of bridges and pavements. A system is described combining traffic sensors and strain gages on highway bridge girders to obtain axle and gross weights. A weight prediction algorithm is derived herein that filters out the dynamic components of bridge response and obtains the equivalent static axle weights by a least-square error minimization. It utilizes self-balancing signal conditioners, magnetic tape switches, analog-digital converters, and a minicomputer to record field data on magnetic tape. Output is subsequently obtained on a digital computer. The system showed predictions of gross truck weight and tandem axles consistent with calibration trucks and random traffic. The paper also describes modifications of the system that would allow its routine use in obtaining weigh-in-motion truck data and would also permit weight processing in the field.
304 citations
01 Jan 1979
TL;DR: A weight prediction algorithm is derived herein that filters out the dynamic components of bridge response and obtains the equivalent static axle weights by a least-square error minimization.
Abstract: Acquisition of truck axle and gross weight information is necessary for structural and maintenance requirements of bridges and pavements. A system is described combining traffic sensors and strain gages on highway bridge girders to obtain axle and gross weights. A weight prediction algorithm is derived herein that filters out the dynamic components of bridge response and obtains the equivalent static axle weights by a least-square error minimization. It utilizes self-balancing signal conditioners, magnetic tape switches, analog-digital converters, and a minicomputer to record field data on magnetic tape. Output is subsequently obtained on a digital computer. The system showed predictions of gross truck weight and tandem axles consistent with calibration trucks and random traffic. The paper also describes modifications of the system that would allow its routine use in obtaining weigh-in-motion truck data and would also permit weight processing in the field.
301 citations
TL;DR: It is suggested that HDL cholesterol is an independent risk factor for CHD, especially in males over 50, and the implication is that increased HDL cholesterol might play a protective role in the pathogenesis of CHD.
Abstract: Using univariate and multivariate analyses, the association between high density lipoprotein (HDL) cholesterol and coronary heart disease (CHD) incidence was investigated. Over 150 cases of myocardial infarction (MI) occurred among 6500 Israeli adult males in a five-year prospective study. At age 50 years and over, there is a significant inverse association between MI incidence and HDL cholesterol. This relationship persists when controlling for risk factors such as age, other cholesterol components, smoking, blood pressure, weight, and diabetes mellitus. Unlike hypercholesterolemia and smoking, the relative risk with HDL cholesterol increases with age above 50. Similar patterns of association occur between HDL cholesterol and angina pectoris incidence, sudden unexpected death and deaths from MI. It is suggested that HDL cholesterol is an independent risk factor for CHD, especially in males over 50, and the implication of this study is that increased HDL cholesterol might play a protective role in the pathogenesis of CHD.
266 citations
TL;DR: The fact that this and previous studies show that the projections of the pallidal complex are more widespread than would be expected if it was only involved in motor functions, raises questions about the functional organization of the basal ganglia.
263 citations
TL;DR: All of the studies indicate that heparan sulfate is a direct mediator of adhesion of cells to the substrate, and hyaluronate-chondroitin complexes in SAM appear to be most important in motility of cells by binding and labilizing fibronectin at the periphery of footpad adhesions, with subsequent cytoskeletal disorganization.
Abstract: When normal or SV40-transformed Balb/c 3T3 cells are treated with the Ca++-specific chelator EGTA, they round up and pull away from their footpad adhesion sites to the serum-coated tissue culture substrate, as shown by scanning electron microscope studies. Elastic membranous retraction fibers break upon culture agitation, leaving adhesion sites as substrate-attached material (SAM) (Cells leave "footprints" of substrate adhesion sites during movement by a very similar process.) SAM contains 1-2% of the cell's total protein and phospholipid content and 5-10% of its glucosamine-radiolabeled polysaccharide, most of which is glycosaminoglycan (GAG). By one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, there is considerable enrichment in SAM for specific GAGs; for the glycoprotein fibronectin; and for the cytoskeletal proteins actin, myosin, and the subunit protein of the 10 nm-diameter filaments. Fibrillar fibronectin of cellular origin and substratum-bound fibronectin of serum origin (cold-insoluble globulin, CIg) have been visualized by immunofluorescence microscopy. The GAG composition in SAM has been examined under different cellular growth and attachment conditions. Heparan sulfate content correlates with glycopeptide content (derived from glycoprotein). Newly attaching cells deposit SAM with principally heparan sulfate and fibronectin and little of the other GAGs. Hyaluronate and chrondroitin proteoglycans are coordinately deposited in SAM as cells begin spreading and movement over the substrate. Cells attaching to serum-coated or CIg-coated substrates deposited SAM with identical compositions. The proteoglycan nature of the GAGs in SAM has been examined, as well as the ability of proteoglycans to form two classes of reversibly dissociable "supramolecular complexes" - one class with heparan sulfate and glycopeptide-containing material and the second with hyaluronate-chondroitin complexes. Enzymatic digestion of "intact" SAM with trypsin or testicular hyaluronidase indicates that (1) only a small portion of long-term radiolabeled fibronectin and cyto-skeletal protein is bound to the substrate via hyaluronate or chondroitin classes of GAG; (2) most of the fibronectin, cytoskeletal protein and heparan sulfate coordinately resist solubilization; and (3) newly synthesized fibronectin, which is metabolically labile in SAM, is linked to SAM by hyaluronate- and/or chondroitin-dependent binding. All of our studies indicate that heparan sulfate is a direct mediator of adhesion of cells to the substrate, possibly by binding to both cell-surface fibronectin and substrate-bound CIg in the serum coating; hyaluronate-chondroitin complexes in SAM appear to be most important in motility of cells by binding and labilizing fibronectin at the periphery of footpad adhesions, with subsequent cytoskeletal disorganization.
TL;DR: In this article, an analysis of the quasi-equilibrium characteristics of an electrolyte-oxide-semiconductor (EOS) system has been carried out by initially considering two limiting cases: an ideal unblocked interface between the electrolyte and the oxide is assumed.
Abstract: In order to provide an improved understanding of ion-sensitive field-effect transistors (ISFET's) an analysis of the quasi-equilibrium characteristics of an electrolyte-oxide-semiconductor (EOS) system has been carried out. The characteristics of this system are examined by initially considering two limiting cases. In the first case, an ideal unblocked interface between the electrolyte and the oxide is assumed. Electrochemical processes of ion exchange dominates and consequently, a Nernstian response is experienced. The second limiting case assumes a totally blocked interface such that the behavior of the EOS system is dictated by electrostatic factors. The analysis is then generalized to examine the case of an electrolyte-pyrogenic SiO 2 -Si system using a site binding model to describe the ionic adsorption processes at the electrolyte-pyrogenic SiO 2 interface. The C-V characteristics and changes in flat-band voltage of the EOS system in response to pH are examined. Analytical results show that in general, the response does not obey the classical Nernst equation. Correlation of theoretical and experimental results yields excellent agreement suggesting that the models used in this study can provide an adequate description of the physical processes.
TL;DR: Improvements in a Newton-Euler approach to spatial open-chain mechanism analysis introduced by one of the authors are presented, which are shown to satisfy a number of necessary conditions, thereby validating to some extent both the methodology and the corresponding computer program.
Abstract: This paper presents some improvements in a Newton-Euler approach to spatial open-chain mechanism analysis introduced by one of the authors in an earlier publication. The improvements have to do both with the introduction of simplified notation and with more efficient computational procedures. The validity and utility of the method is illustrated by an application to the problem of calculating joint torques for the legs of a hexapod locomotion system. The results obtained agree well with experimental measurements and are also shown to satisfy a number of necessary conditions, thereby validating to some extent both the methodology and the corresponding computer program.
TL;DR: Data showed that the fetal glucose pool was in equilibrium with the maternal glucose pool in both normal and diabetic subjects, indicating that a brief maternal fast did not initiate systemic glucose production in human fetus.
Abstract: The effects of pregnancy and diabetes on systemic glucose production rates and the sources of glucose for the human fetus in utero were evaluated in five normal, four gestationally diabetic, and one insulin-dependent diabetic subject undergoing elective caesarean section at term gestation. Five normal nonpregnant women were studied for comparison. Systemic glucose production rates were measured with stable tracer [1-(13)C]glucose according to the prime-constant rate infusion technique. Even though the plasma glucose concentration during normal pregnancy had declined as compared with the nonpregnant subjects (P < 0.0005), the systemic glucose production rate was 16% greater, a rate sufficient to provide the glucose requirement of the fetus at term gestation. The decline in glucose concentration could be the result of an increase in apparent volume of distribution of glucose. Systemic glucose production rates in well-controlled, gestationally diabetic subjects were similar to those in normal pregnant subjects (2.07+/-0.53 vs. 2.42+/-0.51 mg/kg.min). The sources of glucose for the human fetus at term gestation were evaluated by comparing (a) natural variation in (13)C:(12)C ratio of plasma glucose and (b) enriched (13)C:(12)C ratio of plasma glucose during [1-(13)C]glucose infusion in maternal and fetal blood at delivery in both normal and diabetic subjects. These data showed that the fetal glucose pool was in equilibrium with the maternal glucose pool in both normal and diabetic subjects, indicating that a brief maternal fast did not initiate systemic glucose production in human fetus. A materno-fetal gradient was observed for betahydroxybutyrate.
TL;DR: In this paper, the classical notions of solution, to an ordinary differential equation, are sometimes insufficient and three generalisations have been proposed (Filippov, Krasovskij, and, implicitly, Hermes).
TL;DR: In this article, Eshelby's transformed-inclusion analysis has been used to model the transformation toughening: a transformation zone is calculated from an energy balance approach, the size of this zone determining the mechanical energy dissipated during crack propagation.
TL;DR: In this paper, the steady-state flame spread over a thermally thin solid fuel is investigated, and qualitative agreement is obtained with experimental results in the near-extinction limit region.
TL;DR: In this article, a well-collimated NaI gamma detector scanned each sediment column (∼10 cm deep) at daily or weekly intervals for six months, depicting the time evolution of radioactivity with and without added benthos.
TL;DR: Improved oxygenation in the prone position appears to be the result of enhanced ventilation/perfusion ratios and not merely secondary to an alteration in sleep state with positioning of the infant.
Abstract: To determine the optimal position for the preterm infant, arterial oxygen tension (Pao2) was monitored in 16 preterm infants by the transcutaneous method with the infants in both supine and prone positions. When the infants were prone, Pao2 rose by a mean of 7.4 mm Hg (P less than .001), an increase of 15%. In those infants with residual cardiopulmonary disease a 25% increase was noted. The higher Pao2 in the prone position was accompanied by a significant decrease in the amount of time the chest wall moved asynchronously. This improved oxygenation in the prone position appears to be the result of enhanced ventilation/perfusion ratios and not merely secondary to an alteration in sleep state with positioning of the infant. These findings may have important implications in the management of preterm infants, requiring neonatal intensive care.
TL;DR: Improvement in survival of neonates at high risk, particularly those with a very low birth weight (less than 1500 g), has now been described in this country and abroad.
Abstract: IMPROVED survival of neonates at high risk, particularly those with a very low birth weight (less than 1500 g), has now been described in this country and abroad.1 , 2 A major concern persists, how...
01 Jan 1979
TL;DR: A review of the recent theoretical and experimental results which have occurred since the review of Zbinden [3] can be found in this paper. But the review is limited to infrared and Raman measurements since they are complementary to each other in their a...
Abstract: The mechanical properties of polymers are strongly influenced not only by the structure of the material but by the magnitude of the molecular orientation. Thus a great deal of interest exists in information about the molecular orientation in samples introduced by drawing or other forming processes. Several techniques of evaluation of this orientation exist such as birefringence, x-ray diffraction, sonic modulus, and fluorescence measurements [l, 2]. Vibrational analysis of oriented polymers provides a method of determining independently the molecular orientation both in the crystalline and amorphous phases of polymers. By using vibrational techniques, a number of macromolecules have been studied in the solid state for a variety of different processes. It is the purpose of this review to summarize the recent theoretical and experimental results which have occurred since the review of Zbinden [3]. Infrared and Raman measurements will be reported since they are complementary to each other in their a...
TL;DR: In this paper, a triclinic unit cell is proposed for the structure with approximate dimensions a = 5.2 A, b = 4.8 A, c = 35.0 A, α = 115°, β = 121° and γ = 85°.
TL;DR: Review of 11 cases of agenesis of the corpus callosum studied at an institution revealed a high incidence of associated anomalies, with the possible exception of facial abnormalities.
Abstract: Review of 11 cases of agenesis of the corpus callosum studied at our institution revealed a high incidence of associated anomalies. Nine patients had associated malformations of the central nervous system, 6 involving the pyramidal system. Eight cases were associated with malformations in the rest of the body. Review of completely examined cases from the literature yielded 47 examples of associated malformations. These were varied and without consistent pattern, with the possible exception of facial abnormalities.
TL;DR: Density of trophozoite colonization of the jejunal epithelium correlated with stool cyst excretion and Giardia produced no apparent ultrastructural damage in normal mice but elicited a previously undescribed intraluminal cellular immune response during clearance by the host.
TL;DR: It was found that the rate of axonal elongation decreased as neurons aged, related to the changes with age which occur in the axonal transport system.
TL;DR: The spontaneous forward mutation rate at CAN1 did not increase during meiosis, and genetic fine-structure analysis revealed that the map length is at least 40, and possibly as much as 60 X-ray map units; this is the longest gene map yet reported in S. cerevisiae.
Abstract: A system of strains and growth media was developed to allow efficient detection of forward mutation, reversion, complementation, and suppression at the canavanine-resistance (CAN1) locus of Saccharomyces cerevisiae. Genetic fine-structure analysis revealed that the map length is at least 40, and possibly as much as 60 X-ray map units; this is the longest gene map yet reported in S. cerevisiae. Allelic complementation was not observed, despite testing of a large number of allele pairs, and alleles suppressible by the ochre suppressor SUP11 were absent from a sample of 48 spontaneous mutants and occurred infrequently (7%) among a sample of ultraviolet-induced mutants. Infrequent mutant types included canavanine-resistant mutants capable of arginine uptake and alleles thought to represent deletions or inversions. In contrast to previous reports in the literature, the spontaneous forward mutation rate at CAN1 did not increase during meiosis.
TL;DR: The results show that a dramatic increase in the synthesis or accumulation in the parotid glands of a series of proteins rich in proline also occurs with isoproterenol treatment, and these proline-rich proteins (PRPs) comprise more than 50% of the total soluble proteins inParotid gland homogenates.
TL;DR: Clinical isolates of Pseudomonas aeruginosa from patients with cystic fibrosis were studied in an effort to determine the unique characteristics of the infecting strains and to elucidate the pattern of colonization.
Abstract: Clinical isolates of Pseudomonas aeruginosa from patients with cystic fibrosis were studied in an effort to determine the unique characteristics of the infecting strains and to elucidate the pattern of colonization. Of 413 patients studied, 81% were chronically infected with P. aeruginosa. Patients from whom P. aeruginosa was never or only occasionally isolated were in better clinical condition than the chronically infected patients. Isolates were classified into six morphologic varieties: classic, rough, mucoid, gelatinous, dwarf, and enterobacter. Most patients had two or more of these varieties. Such multiple varieties from the same individual were of the same serotype but often differed in antibiotic susceptibility as determined by both the disk and the minimal inhibitory concentration methods. These differences were apparent when mucoid strains were compared with nonmucoid strains and when nonmucoid strains were compared with one another. Studies of antibiotic susceptibility should be performed on each morphologically different type of P. aeruginosa obtained from patients with cystic fibrosis. Chronic pulmonary infection is responsible for most of the morbidity and almost all of the mortality in patients with cystic fibrosis. Severe chron
TL;DR: The response of a single Node of Ranvier to short duration biphasic stimulating currents was studied and peak twitch force from the tibialis anterior muscle of cat was found to be reduced by the use of bipwasic motor nerve stimulation in place of monophasic stimulation.
Abstract: The response of a single Node of Ranvier to short duration biphasic stimulating currents was studied. Such stimulus patterns are known to be less likely to induce tissue damage than are longer monophasic stimuli. The presence of the anodic phase of a pulse pair was found to abolish excitation in cases where the cathodic phase alone was near threshold. In addition, peak twitch force from the tibialis anterior muscle of cat was found to be reduced by the use of biphasic motor nerve stimulation in place of monophasic stimulation. The abolition phenomenon could be eliminated by the introduction of a delay of 100 μs between the phases of a biphasic stimulus waveform.
TL;DR: The observations reported here suggest that initial cell plating densities may provide environmental conditions deterministic to a particular limb phenotype, and relating differential vascularization and nutrient flow to the determination of limb phenotypes in vivo is presented.