gebhart/patrepeval huggingface dataset:
Exercise-induced arterial hypoxemia (1999)

Exercise-induced arterial hypoxemia (EIAH) at or near sea level is now recognized to occur in a significant number of fit, healthy subjects of both genders and of varying ages. Our review aims to define EIAH and to critically analyze what we currently understand, and do not understand, about its underlying mechanisms and its consequences to exercise performance. Based on the effects on maximal O(2) uptake of preventing EIAH, we suggest that mild EIAH be defined as an arterial O(2) saturation of 93-95% (or 3-4% <rest), moderate EIAH as 88-93%, and severe EIAH as <88%. Both an excessive alveolar-to-arterial PO(2) difference (A-a DO(2)) (>25-30 Torr) and inadequate compensatory hyperventilation (arterial PCO(2) >35 Torr) commonly contribute to EIAH, as do acid- and temperature-induced shifts in O(2) dissociation at any given arterial PO(2). In turn, expiratory flow limitation presents a significant mechanical constraint to exercise hyperpnea, whereas ventilation-perfusion ratio maldistribution and diffusion limitation contribute about equally to the excessive A-a DO(2). Exactly how diffusion limitation is incurred or how ventilation-perfusion ratio becomes maldistributed with heavy exercise remains unknown and controversial. Hypotheses linked to extravascular lung water accumulation or inflammatory changes in the "silent" zone of the lung's peripheral airways are in the early stages of exploration. Indirect evidence suggests that an inadequate hyperventilatory response is attributable to feedback inhibition triggered by mechanical constraints and/or reduced sensitivity to existing stimuli; but these mechanisms cannot be verified without a sensitive measure of central neural respiratory motor output. Finally, EIAH has detrimental effects on maximal O(2) uptake, but we have not yet determined the cause or even precisely identified which organ system, involved directly or indirectly with O(2) transport to muscle, is responsible for this limitation.
Endocytosis and intracellular sorting of ricin and Shiga toxin (1994)

Ricin and Shiga toxin belong to a group of protein toxins with targets in the cytosol. These toxins consist of one moiety that binds the toxin molecule to cell surface receptors, and another enzymatically active moiety that enters the cytosol after endocytic uptake of the toxin. The toxins are of current interest in relation to disease and the construction of immunotoxins. Moreover, they have proven useful to investigate mechanisms of endocytosis and to follow intracellular pathways of transport. Some of the recent results obtained with ricin and Shiga toxin are discussed.
Prolonged hematopoiesis in a primate bone marrow culture system: characteristics of stem cell production and the hematopoietic microenvironment (1979)

Maintenance of myelopoiesis and pluripotential stem cell production for prolonged periods in vitro hitherto has been limited to mouse bone marrow culture. In an effort to adapt the system for use in higher species, particularly in human and non-human primates, studies were undertaken using the prosimian species, Tupaia glis (tree shrew). In a number of experiments the duration of sustained normal hematopoiesis observed in cultures of this species, following a single inoculum of 5 X 10(6)--10(7) bone marrow cells, with or without addition of fresh allogeneic bone marrow exceeded 1 yr. Analysis of suspension cells obtained by weekly demidepopulation of such cultures revealed production of CFU-C, differentiating neutrophils, and basophils at high levels. Direct comparison with murine cultures indicated that in both species a complex series of cellular interactions takes place within an adherent environment of marrow-derived endothelial cells, macrophages, and fat-containing cells. Certain functional and ultrastructural features served to distinguish murine from Tupaia marrow cultures, and the prolonged duration of in vitro hematopoiesis in the latter species could be attributed to a regenerative capacity possessed by its adherent hematopoietic microenvironment. The availability of this primate marrow culture system should facilitate studies of hematopoiesis, viral leukemogenesis, and transplantation biology, which have more direct relevance to man than that provided by the existing murine system.
Electrical stimulation of the ventral and dorsal columns of the spinal cord for relief of chronic intractable pain: preliminary report. (1975)

Serious questions are raised as to whether electrical control of pain is related to stimulation of the dorsal columns per se or the conduction of the electrical impulse via the cerebrospinal fluid to the ventrolateral columns. Percutaneous on-surface spinal cord stimulation is advocated as an accurate screening method before implantation. Of 27 patients who underwent dorsal column stimulator implants, the last three patients also underwent ventral column stimulator implants. Results in the patients with both implants tend to predict much better results with the possibility that ventral column stimulation alone is sufficient.
Distributed strain measurement based on a fiber Bragg grating and its reflection spectrum analysis (1996)

A method of extracting the strain profile along a fiber Bragg grating from the intensity reflection spectrum is described. The procedure is based on a filter synthesis theory that relates the aperiodicity of a grating with its reflection spectrum. To illustrate the approach, we measured the strain profile near a hole in a plate and obtained a strain resolution of 80 micro. The spatial resolution depends on the strain gradient; i.e., the higher the gradient, the better the resolution. A resolution of 0.8 mm was achieved for a 5-mm grating with a gradient of 250 micro/mm.
Clostridium difficile Toxins A and B Are Cation-dependent UDP-glucose Hydrolases with Differing Catalytic Activities (1998)

Toxins A and B of Clostridium difficile are UDP-glucose glucosyltransferases that exert their cellular toxicity primarily through their abilities to monoglucosylate, and thereby inactivate, Rho family small GTPases. Toxin A also hydrolyzes UDP-glucose, although this activity is not well characterized. In this study, we measured the kinetics of UDP-glucose hydrolysis by toxins A and B and found significant differences in the catalytic activities of these two structurally homologous toxins. The toxins displayed similar Michaelis constants (Km) for UDP-glucose, but the maximal velocity (Vmax) of toxin B was approximately 5-fold greater than that of toxin A. Toxins A and B exert their enzymatic actions intracellularly, and, interestingly, we found that each toxin absolutely required K+ for optimal hydrolase activity; Na+ was inactive. The toxins also required certain divalent cations for activity and exhibited a significantly greater Vmax and lower Km in the presence of Mn2+ as compared with Mg2+. We conclude that C. difficile toxins A and B are cation-dependent UDP-glucose hydrolases that differ significantly in their catalytic activities, a finding that may have important implications in understanding their different cytotoxic effects.
Mesenchymal stem cells for the treatment of neurodegenerative disease (2010)

Mesenchymal stem cells/marrow stromal cells (MSCs) present a promising tool for cell therapy, and are currently being tested in US FDA-approved clinical trials for myocardial infarction, stroke, meniscus injury, limb ischemia, graft-versus-host disease and autoimmune disorders. They have been extensively tested and proven effective in preclinical studies for these and many other disorders. There is currently a great deal of interest in the use of MSCs to treat neurodegenerative diseases, in particular for those that are fatal and difficult to treat, such as Huntington's disease and amyotrophic lateral sclerosis. Proposed regenerative approaches to neurological diseases using MSCs include cell therapies in which cells are delivered via intracerebral or intrathecal injection. Upon transplantation into the brain, MSCs promote endogenous neuronal growth, decrease apoptosis, reduce levels of free radicals, encourage synaptic connection from damaged neurons and regulate inflammation, primarily through paracrine actions. MSCs transplanted into the brain have been demonstrated to promote functional recovery by producing trophic factors that induce survival and regeneration of host neurons. Therapies will capitalize on the innate trophic support from MSCs or on augmented growth factor support, such as delivering brain-derived neurotrophic factor or glial-derived neurotrophic factor into the brain to support injured neurons, using genetically engineered MSCs as the delivery vehicles. Clinical trials for MSC injection into the CNS to treat traumatic brain injury and stroke are currently ongoing. The current data in support of applying MSC-based cellular therapies to the treatment of neurodegenerative disorders are discussed.
Mechanisms of current rectification in an STM tunnel junction and the measurement of an operational tunneling time (1989)

The effects of material, thermal, and geometrical asymmetries on the nonlinearity of the I-V characteristics of a scanning tunneling microscope (STM) tunneling junction are investigated theoretically and experimentally. As a consequence of the nonlinearity, an STM junction can rectify an incident laser beam to produce both DC and AC tunneling current components. Using the dependence of the DC rectified current on the tip-sample distance s and the laser frequency v, an operational definition of a tunneling time is proposed. An experiment using a laser-irradiated STM junction is also performed to measure the rectified current as a function of s, for a fixed v. From the preliminary results of this experiment, a tunneling time on the order of 1.8 fs is determined. This time is in reasonable agreement with those obtained in other experimental and theoretical studies of tunneling junctions of comparable dimensions and energies. It is also shown that the AC current contains components at the laser frequency and its higher harmonics. This implies that the STM junction can be used as a nonlinear device to detect, generate, and measure laser frequency harmonics.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Development and Testing of Low-Volume Hyperoncotic, Hyperosmotic Spray-Dried Plasma for the Treatment of Trauma-Associated Coagulopathy (2011)

Plasma can be spray dried and reconstituted to one-third of its original volume without compromising the coagulation properties in vivo. This shelf-stable, low-volume, hyperoncotic, hyperosmotic plasma is a logistically attractive option for the treatment of trauma-associated coagulopathy in austere environments, such as a battlefield.
Novel Role for STIM1 as a Trigger for Calcium Influx Factor Production (2008)

STIM1 has been recently identified as a Ca(2+) sensor in endoplasmic reticulum (ER) and an initiator of the store-operated Ca(2+) entry (SOCE) pathway, but the mechanism of SOCE activation remains controversial. Here we focus on the early ER-delimited steps of the SOCE pathway and demonstrate that STIM1 is critically involved in initiating of production of calcium influx factor (CIF), a diffusible messenger that can deliver the signal from the stores to plasma membrane and activate SOCE. We discovered that CIF production is tightly coupled with STIM1 expression and requires functional integrity of its intraluminal sterile alpha-motif (SAM) domain. We demonstrate that 1) molecular knockdown or overexpression of STIM1 results in corresponding impairment or amplification of CIF production and 2) inherent deficiency in the ER-delimited CIF production and SOCE activation in some cell types can be a result of their deficiency in STIM1 protein; expression of a wild-type STIM1 in such cells was sufficient to fully rescue their ability to produce CIF and SOCE. We found that glycosylation sites in the ER-resident SAM domain of STIM1 are essential for initiation of CIF production. We propose that after STIM1 loses Ca(2+) from EF hand, its intraluminal SAM domain may change conformation, and via glycosylation sites it can interact with and activate CIF-producing machinery. Thus, CIF production appears to be one of the earliest STIM1-dependent events in the ER lumen, and impairment of this process results in impaired SOCE response.
Speaker recognition: a tutorial (1997)

A tutorial on the design and development of automatic speaker-recognition systems is presented. Automatic speaker recognition is the use of a machine to recognize a person from a spoken phrase. These systems can operate in two modes: to identify a particular person or to verify a person's claimed identity. Speech processing and the basic components of automatic speaker-recognition systems are shown and design tradeoffs are discussed. Then, a new automatic speaker-recognition system is given. This recognizer performs with 98.9% correct decalcification. Last, the performances of various systems are compared.
Effects of epinephrine on lipid metabolism in resting skeletal muscle (1998)

The effects of physiological (0, 0.1, 2.5, and 10 nM) and pharmacological (200 nM) epinephrine concentrations on resting skeletal muscle lipid metabolism were investigated with the use of incubated rat epitrochlearis (EPT), flexor digitorum brevis (FDB), and soleus (SOL) muscles. Muscles were chosen to reflect a range of oxidative capacities: SOL > EPT > FDB. The muscles were pulsed with [1-14C]palmitate and chased with [9,10-3H]palmitate. Incorporation and loss of the labeled palmitate from the triacylglycerol pool (as well as mono- and diacylglycerol, phospholipid, and fatty acid pools) permitted the simultaneous estimation of lipid hydrolysis and synthesis. Endogenous and exogenous fat oxidation was quantified by 14CO2 and 3H2O production, respectively. Triacylglycerol breakdown was elevated above control at all epinephrine concentrations in the oxidative SOL muscle, at 2.5 and 200 nM (at 10 nM, P = 0.066) in the FDB, and only at 200 nM epinephrine in the EPT. Epinephrine stimulated glycogen breakdown in the EPT at all concentrations but only at 10 and 200 nM in the FDB and had no effect in the SOL. We further characterized muscle lipid hydrolysis potential and measured total hormone-sensitive lipase content by Western blotting (SOL > FDB > EPT). This study demonstrated that physiological levels of epinephrine cause measurable increases in triacylglycerol hydrolysis at rest in oxidative but not in glycolytic muscle, with no change in the rate of lipid synthesis or oxidation. Furthermore, epinephrine caused differential stimulation of carbohydrate and fat metabolism in glycolytic vs. oxidative muscle. Epinephrine preferentially stimulated glycogen breakdown over triacylglycerol hydrolysis in the glycolytic EPT muscle. Conversely, in the oxidative SOL muscle, epinephrine caused an increase in endogenous lipid hydrolysis over glycogen breakdown.
Soft Lithographic Patterning of Hyaluronic Acid on Hydrophilic Substrates Using Molding and Printing (2004)

Hyaluronic acid (HA) was patterned using two soft lithographic methods on various substrates including glass, silicon dioxides, poly(hydroxyethyl methacrylate) [poly(HEMA)], polystyrene cell culture dishes, and biodegradable polylactic glycolic acid (PLGA), with no or minor chemical modification. Results indicate that HA could be used as a general platform on hydrophilic substrates for cell and protein patterning (see Figure).
Mobile robot navigation by circular path planning algorithm using camera and ultrasonic sensor (2009)

In this paper we propose a circular path planning algorithm using a monocular camera and ultrasonic sensors in order for a mobile robot to avoid obstacles. The proposed circular path algorithm determines the radius of a circular to avoid the detected obstacle using its position and size data. A monocular camera and ultrasonic sensors are used in order to compensate the shortage of usage of each sensor. Multiple sensor data are combined using the grid map method. Velocity of the mobile robot to move along the circular path to avoid an obstacle is controlled to guarantee stable motion. The control performance of the proposed algorithm is shown through the experiments using Pioneer2-DX mobile robot.
The interleukin-12 and interleukin-12 receptor system in normal and transformed human B lymphocytes. (2002)

Taken together, the studies herein reviewed indicate that human B-cells, at variance with their murine counterparts, can produce IL-12 following CD40 ligation. IL-12 p35 and p40 transcripts are found in B-cells from different lymphoproliferative disorders, but the evidence that the cytokine is produced at the protein level is poor. IL-12R is expressed in the main human B-cell subsets, but it is functional only in naive B-cells. Finally, the failure of transformed B-cell lines to express IL-12Rb2 mRNA opens up new perspectives in the investigation of B-cell malignant transformation.
Identification of a hemagglutinin-specific idiotype associated with reovirus recognition shared by lymphoid and neural cells. (1982)

A xenogeneic antiserum raised to antireovirus immunoglobulin was used to define an idiotypic determinant present on antibodies to reovirus type 3 hemagglutinin. The same idiotype was identified on nonimmune lymphoid cells and on neuronal cells that specifically bind the hemagglutinin of type 3 reovirus. This idiotypic determinant, called Id3, is shared by (a) a monoclonal antibody to the neutralization site of hemagglutinin from type 3 reovirus; (b) BALB/c serum antibodies to the hemagglutinin of reovirus type 3; (c) R1.1, a murine thymoma cell line that binds reovirus type 3; (d) primary cultures of murine neuronal cells. The presence of an idiotype shared by antihemagglutinin antibodies and by structures on nonlymphoid cells suggests a general relationship between disparate receptors that recognize a common determinant. Furthermore, this suggests a novel approach for the study of viral receptor interactions and for analysis of mechanisms of autoimmune responses.
Inhibitory actions of the selective serotonin re‐uptake inhibitor citalopram on HERG and ventricular L‐type calcium currents (2002)

Using whole-cell patch clamp recording of heterologous HERG-mediated currents in transfected mammalian cells, we observed that the selective serotonin re-uptake inhibitor citalopram blocks HERG with an IC(50) of 3.97 microM. This is slightly less potent than fluoxetine in our system (IC(50) of 1.50 microM). In isolated guinea pig ventricular cardiomyocytes citalopram inhibited L-type calcium current (I(Ca,L)). The voltage dependence of I(Ca,L) inactivation in the presence of 100 microM citalopram was shifted significantly leftward. As a result, the I(Ca,L) 'window' in citalopram was found to be (a) smaller and (b) leftward-shifted compared to control. The effects of citalopram on both calcium current amplitude and the I(Ca,L) 'window' may help to explain citalopram's good cardiac safety profile, given its propensity to block HERG at excessive dosages.
Post-Passage rock inhibition induces cytoskeletal aberrations and apoptosis in Human embryonic stem cells (2019)

Human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) are prone to anoikis after single cell dissociation. The small molecule, Y-27632 is known to increase survival of hESCs and hiPSCs by inhibiting the Rho-associated protein kinase (ROCK). However, the underlying mechanisms are still unclear. Here, we thoroughly screened small molecules to investigate the adhesion and survival of hESCs in adherent culture. Y-27632 provided higher adhesion and survival of hESCs by increased cell migration and preventing cell blebbing in single dissociated cells. The combination of Matrigel with poly-d-lysine increased the attachment and survival of dissociated cells via actin filament and microtubule spreading in Y-27632-treated cells. Although Y-27632 prevented apoptosis by suppressing actin filament contraction, microtubule bundling, and blebbing, prolonged Y-27632 treatment presented a different morphology in the attached growing hESC colony. It induced apoptosis of cells by promoting cytoplasmic spread, E-cadherin structural change, and increased detachment. It also induced actin cytoskeleton disruption, combined with microtubule and intermediate filament elongation. For optimal hPSC culture, our research suggests that Y-27632 should be removed shortly after passaging. Keywords: Cytoskeletal changes, ROCK inhibitor, Apoptosis, Human embryonic stem cells, Adhesion, Extracellular matrices
Immunoglobulins from Egg Yolk: Isolation and Purification (1992)

ABSTRACT Simple water dilution was employed for the separation of water‐soluble plasma proteins from egg yolk granules. An optimum recovery of immunoglobulin Y (IgY, 93–96%) in water‐soluble fraction was obtained by sixfold water dilution at pH between 5.0–5.2 with incubation time of 6 hr at 4°C. Among the factors studied, pH was found to be the most important factor affecting IgY recovery. Active IgY of high purity with good recovery was obtained by a combination of several techniques including salt precipitation, alcohol precipitation, ultrafiltration, gel filtration and ion exchange chromatography. Salt precipitation, ultrafiltration, and get filtration is the recommended sequence. Over 100 mg of electrophoretically pure IgY was routinely obtained from one egg.
Biologically Active Domain of the Secreted Form of the Amyloid β/A4 Protein Precursora (1993)

The amyloid beta/A4 protein precursor (APP), a large transmembrane protein, is expressed ubiquitously in many organisms, as well as in a variety of cultured cells. Studies of the synthesis and processing of APP have revealed several intricate metabolic pathways for this protein. One of these pathways involves the cleavage of APP in the middle of the beta/A4 domain and results in the secretion of the large amino-terminal portion of the protein. The biological function of this secreted form of APP has been the subject of intense investigation by several groups and various activities have been described for the different domains of APP studied. Our initial approach was to create a fibroblast cell line in which APP expression is dramatically reduced. These fibroblasts, called A-1, have a very slow growth rate. Addition of exogenous APP in the medium of A-1 cells restores their growth to the level of normal parent fibroblasts, demonstrating a growth factor-like activity for the secreted form of APP. Using APP fragments made in bacteria as well as synthetic peptides, we have been able to locate the active site of APP within a domain of 17 amino-acids (Ala319-Met335). This domain of APP can stimulate neurite extension of cultured neuroblastoma cells and it is proposed that APP mediates this effect through binding to a cell surface receptor, triggering intracellular transduction mechanisms. Thus, the secreted form of APP can function as a growth and/or differentiation factor and the site involved in these activities is within a 17-mer domain in the middle of the molecule. Our current lines of research seek to further characterize the mechanisms of APP function as well as its activity in vivo.