bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Activation of the Transcription Factor Cyclic AMP Response Element Binding Protein (CREB) in Macrophages following Infection with Pathogenic and Nonpathogenic Mycobacteria and Role for CREB in Tumor Necrosis Factor Alpha Production
Authors: Roach Shannon K. , Lee Seong-Beom , Schorey Jeffrey S. 
Published: December 2004

ABSTRACT

Previous studies in our laboratory have shown a differential activation of the mitogen-activated protein kinases (MAPKs) in primary bone marrow-derived macrophages following infection with pathogenic
Mycobacterium avium
compared to the activation following infection with nonpathogenic
Mycobacterium smegmatis
. Additionally,
M. smegmatis
-infected macrophages produced significantly elevated levels of tumor necrosis factor alpha (TNF-α) compared to the levels produced by
M. avium
-infected macrophages. The TNF-α production was dependent on both p38 and extracellular signal-regulated kinase 1/2 (ERK 1/2) activation. However, the macrophage transcription factors downstream of the MAPKs, which were required for TNF-α production, remained undefined. In this study we determined that the transcription factor cyclic AMP response element binding protein (CREB) is significantly more activated in
M. smegmatis
-infected macrophages than in
M. avium
-infected macrophages. We also found that CREB activation was dependent on p38 and protein kinase A but not on ERK 1/2 or calmodulin kinase II. Moreover, mutating the cAMP-responsive element on the TNF-α promoter resulted in significantly diminished promoter activity following
M. smegmatis
infection but not
M. avium
infection. The inability of macrophages infected with
M. avium
to sustain MAPK activation and to produce high levels of TNF-α was due, in part, to an increase in serine/threonine phosphatase PP2A activity. Our studies are the first to demonstrate an important role for the transcription factor CREB in TNF-α production by mycobacterium-infected macrophages, as well as a role for
M. avium
's induction of PP2A phosphatase activity as a mechanism to limit macrophage activation.
Replication Dynamics of
Mycobacterium tuberculosis
in Chronically Infected Mice
Authors: Muñoz-Elías Ernesto J. , Timm Juliano , Botha Tania , Chan Wai-Tsing , Gomez James E. , McKinney John D. 
Published: December 2004

ABSTRACT
The dynamics of host-pathogen interactions have important implications for the design of new antimicrobial agents to treat chronic infections such as tuberculosis (TB), which is notoriously refractory to conventional drug therapy. In the mouse model of TB, an acute phase of exponential bacterial growth in the lungs is followed by a chronic phase characterized by relatively stable numbers of bacteria. This equilibrium could be static, with little ongoing replication, or dynamic, with continuous bacterial multiplication balanced by bacterial killing. A static model predicts a close correspondence between “viable counts” (live bacteria) and “total counts” (live plus dead bacteria) in the lungs over time. A dynamic model predicts the divergence of total counts and viable counts over time due to the accumulation of dead bacteria. Here, viable counts are defined as bacterial CFU enumerated by plating lung homogenates; total counts are defined as bacterial chromosome equivalents (CEQ) enumerated by using quantitative real-time PCR. We show that the viable and total bacterial counts in the lungs of chronically infected mice do not diverge over time. Rapid degradation of dead bacteria is unlikely to account for the stability of bacterial CEQ numbers in the lungs over time, because treatment of mice with isoniazid for 8 weeks led to a marked reduction in the number of CFU without reducing the number of CEQ. These observations support the hypothesis that the stable number of bacterial CFU in the lungs during chronic infection represents a static equilibrium between host and pathogen.
Development of a Chinchilla Model To Allow Direct, Continuous, Biophotonic Imaging of Bioluminescent Nontypeable
Haemophilus influenzae
during Experimental Otitis Media
Authors: Novotny Laura A. , Mason Kevin M. , Bakaletz Lauren O. 
Published: December 2004

ABSTRACT

We transformed a nontypeable
Haemophilus influenzae
clinical isolate with a plasmid containing the
luxCDABE
operon driven by the
H. influenzae
outer membrane protein P2 promoter. Herein, we demonstrate the ability to detect bioluminescence and to monitor infection within the nasopharynges, eustachian tubes, and middle ears of chinchillas after intranasal and transbullar challenges.
Vaccination with Purified Dr Fimbriae Reduces Mortality Associated with Chronic Urinary Tract Infection Due toEscherichia coliBearing Dr Adhesin
Authors: Goluszko Pawel , Goluszko Elzbieta , Nowicki Bogdan , Nowicki Stella , Popov Vsevolod , Wang Hui-Qun 
Published: December 2004

ABSTRACTThe vaccination of C3H/HeJ mice withEscherichia coliDr fimbrial antigen reduced mortality associated with an experimental urinary tract infection due to a homologous strain bearing Dr adhesin. Immune sera with high titers of anti-Dr antibody inhibited bacterial binding to bladders and kidneys but did not affect the rate of renal colonization.
Osmolarity, a Key Environmental Signal Controlling Expression of Leptospiral Proteins LigA and LigB and the Extracellular Release of LigA
Authors: Matsunaga James , Sanchez Yolanda , Xu Xiaoyi , Haake David A. 
Published: December 2004

ABSTRACT

The high-molecular-weight leptospiral immunoglobulin-like repeat (Lig) proteins are expressed only by virulent low-passage forms of pathogenic
Leptospira
species. We examined the effects of growth phase and environmental signals on the expression, surface exposure, and extracellular release of LigA and LigB. LigA was lost from stationary-phase cells, while LigB expression was maintained. The loss of cell-associated LigA correlated with selective release of a lower-molecular-weight form of LigA into the culture supernatant, while LigB and the outer membrane lipoprotein LipL41 remained associated with cells. Addition of tissue culture medium to leptospiral culture medium induced LigA and LigB expression and caused a substantial increase in released LigA. The sodium chloride component of tissue culture medium was primarily responsible for the enhanced release of LigA. Addition of sodium chloride, potassium chloride, or sodium sulfate to leptospiral medium to physiological osmolarity caused the induction of both cell-associated LigA and LigB, indicating that osmolarity regulates the expression of Lig proteins. Osmotic induction of Lig expression also resulted in enhanced release of LigA and increased surface exposure of LigB, as determined by surface immunofluorescence. Osmolarity appears to be a key environmental signal that controls the expression of LigA and LigB.
Leptin responses to short term exercise in college level male rowers
Authors: Jürimäe J , Jürimäe T 
Published: December 2004

Objective:To investigate plasma leptin response to short term exercise in college level male rowers.Methods:Thirteen rowers performed a 30 minute maximal rowing ergometer test. Venous blood samples were obtained before, immediately after, and after 30 minutes of recovery. Concentrations of leptin, insulin, growth hormone, insulin-like growth factor-I (IGF-I), and IGF binding protein-3 (IGFBP-3) were measured.Results:Plasma leptin was significantly (p<0.05) decreased (from a mean (SD) of 2.7 (0.6) to 2.1 (0.8) ng/ml) and growth hormone significantly increased (from 0.6 (0.9) to 4.6 (5.4) μIU/l) immediately after the 30 minute maximal rowing exercise session (distance covered 7870.4 (443.3) m; blood lactate immediately after the test 14.9 (4.3) mmol/l). All other blood variables measured were not significantly changed as a result of the ergometer test. A positive relation was observed between the decreased plasma leptin concentration immediately after the test and the distance covered (R2 =  0.645; p<0.05). Changes in leptin and IGF-I concentrations immediately after the test were also related (R2 =  0.390; p<0.05). Percentage body fat explained 89.6% (p<0.05) of the variance (R2× 100) in basal leptin concentration. After normalisation for body fat, basal leptin was related (p<0.05) to basal insulin (r =  0.82) and training history (r =  −0.60).Conclusion:Leptin is sensitive to relatively short term intense exercise when all major muscles are involved.
An analysis of the pacing strategy adopted by elite competitors in 2000 m rowing
Authors: Garland S W 
Published: December 2004

Objectives:To determine the pacing strategies adopted by elite rowers in championship 2000 m races.Methods:Split times were obtained for each boat in every heavyweight race of the Olympic Games in 2000 and World Championships in 2001 and 2002, and the top 170 competitors in the British Indoor Rowing Championships in 2001 and 2002. Data were only included in subsequent analysis if there was good evidence that the athlete or crew completed the race in the fastest possible time. The remaining data were grouped to determine if there were different strategies adopted for on-water versus ergometer trials, “winners” versus “losers”, and men versus women.Results:Of the 1612 on-water race profiles considered, 948 fitted the inclusion criteria. There were no differences in pacing profile between winners and losers, and men and women, although on-water and ergometry trials showed a competitively meaningful significant difference over the first 500 m sector. The average profile showed that rowers performed the first 500 m of the race faster than subsequent sectors—that is, at a speed of 103.3% of the average speed for the whole race, with subsequent sectors rowed at 99.0%, 98.3%, and 99.7% of average speed for on-water rowing, and 101.5%, 99.8%, 99.0%, and 99.7% for ergometry.Conclusions:These data indicate that all athletes or crews adopted a similar fast start strategy regardless of finishing position or sex, although the exact pace profile was dependent on rowing mode. This strategy should be considered by participants in 2000 m rowing competitions.
Biomarker Responses during and after Treatment with Nesiritide Infusion in Patients with Decompensated Chronic Heart Failure
Authors: Miller Wayne L , Hartman Karen A , Burritt Mary F , Borgeson Daniel D , Burnett John C , Jaffe Allan S 
Published: December 2004

Abstract
Background: Objective methods to assess the adequacy of medication therapy for patients with advanced heart failure are lacking. Serial measurements of biomarkers might be beneficial. Therapy guided by N-terminal pro-B-type natriuretic peptide (NT-proBNP) might be helpful because NT-proBNP should be lowered by therapies that decrease endogenous BNP secretion.
Methods: NT-proBNP and BNP were measured in a nonconsecutive patient cohort receiving clinically indicated intravenous nesiritide. Blood samples were drawn before, at 6 and 24 h during, and at 6 h after infusion. A reduction in NT-proBNP was defined as a decrease from baseline during infusion (“infusion responders”) of &gt;3 SD of the variability of the assay measurement (∼20%). Patients with decreases &gt;20% in both NT-pro BNP and BNP at 6 h post infusion were designated “biochemical responders”.
Results: Forty patients [27 males; mean (SE) age, 68 (2) years; mean (SE) left ventricular ejection fraction, 25 (1.4)%] were studied. All patients improved clinically. Overall, the changes in NT-proBNP were a 18 (4.6)% [mean (SE)] and 19.8% (median) decrease from baseline at 24 h of infusion and a 22 (6.0)% and 17.8% decrease at 6 h post infusion (P &lt;0.001 compared with baseline). In a large number of patients, decreases in NT-proBNP were, however, within the variability of the assay. Subgroup analysis showed that 22 of 40 patients were infusion responders with a &gt;20% decrease from baseline in NT-proBNP during nesiritide infusion, whereas only 12 patients were biochemical responders with &gt;20% decreases from baseline postinfusion for both NT-proBNP and BNP.
Conclusions: In this study, many patients had decreased NT-proBNP and BNP values after therapy with nesiritide, but the majority of patients did not demonstrate biochemically significant decreases in analytes despite a clinical response. Until we know more about the responses of natriuretic peptides to therapies such as nesiritide, a strategy of monitoring NT-proBNP and BNP to guide therapy cannot be universally advocated.
Geschichte und Chemie des Schwarzpulvers. Le charbon fait la poudre
Authors: Seel Fritz 
Published: December 2004

AbstractEs gibt wohl kaum ein anderes Ereignis in der Geschichte der Menschheit, das die Verbreitung und die Vernichtung von Kulturen, aber auch das Schicksal Einzelner mehr beeinflußt hat, als die Erfindung des Schießpulvers und seine Verwendung in Feuerwaffen. 500 Jahre lang – bis zur Erfindung des rauchlosen Pulvers im vergangenen Jahrhundert – war es eine Mischung aus Kalisalpeter, Holzkohle und Schwefel.Mit der Theorie der chemischen Reaktionen, die Entzündung und die Explosion dieses älteren Schießpulvers – des „Schwarzpulvers”︁ ‐ auslösen, haben sich viele berühmete Chemiker befaßt: Albertus Magnus, Roger Bacon, Claude Louis Berthollet, Joseph Louis Proust, Jöns Jacob Berzelius, Robert Bunsen. In neuerer Zeit scheint K. A. Hofmann [1] der letzte gewesen zu sein, der sich mit diesem Problem experimentell als Grundlagenforscher beschäftigt hat. Bis in die jüngste Zeit ist jedoch die nicht nur historisch, sondern auch vom rein chemischen Standpunkt faszinierende Schwarzpulver‐Reaktion nicht mit den subtilen Methoden der modernen physikalischen und präparativen Chemie erforscht worden. Auch in unserer Zeit spielt Schwarzpulver noch eine Rolle als technisches Produkt.
Flüssige Metalle
Authors: Hensel Friedrich , Winter Roland 
Published: December 2004

AbstractFlüssige Metalle unterscheiden sich von nichtmetallischen Flüssigkeiten, z. B. Wasser, durch die sogenannten „metallischen”︁ Eigenschaften, zu denen vor allem die hohe elektrische Leitfähigkeit, das sehr gute Wärmeleitvermögen, die hohe Verdampfungswärme und der große, bis zu hohen Temperaturen reichende Flüssigkeitsbereich gehören. Es ist sofort einsichtig, daß flüssige Metalle wegen dieser Kombination physikalischer Eigenschaften als Hochtemperatur‐Arbeitsflüssigkeiten besonders geeignet sind. Konsequenterweise ist ihr Einsatz in technischen Anlagen zur Produktion, Speicherung und Direktumwandlung von Energie, die bei hohen Temperaturen arbeiten, intensiv diskutiert und experimentell untersucht worden. Für die Auswahl eines bestimmten Metalls als Arbeitsmedium zum optimalen Betrieb solcher Anlagen ist die Kenntnis der physikalischchemischen Eigenschaften der Metalle wichtige Voraussetzung.
Die Wirkungen von Luftverunreinigungen auf Waldökosysteme
Authors: Schulze Ernst‐Detlef , Lange Otto Ludwig 
Published: December 2004

AbstractCharakteristisch für die “neuartigen Waldschäden” ist, daß sie auf großer Fläche und an mehreren Baumarten auftreten. Es handelt sich bei ihnen um eine Vielzahl von Symptomen, die im Einzelfall keinesfalls neu zu sein brauchen. Der folgende Beitrag konzentriert sich auf die Situation im Fichtelgebirge, wo Wissenschaftler aus sieben bayerischen Universitäten versucht haben, auf den gleichen Versuchsflächen die verschiedenen Hypothesen der Schadensursachen vergleichend zu untersuchen.
Was ist Natur?? Charaktere der Natur aus der Sicht der modernen Naturwissenschaft
Authors: Böhme Gernot 
Published: December 2004

AbstractDie Frage, “Was ist Natur?”, ist keine Frage der Naturwissenschaft, die ja vielmehr Gegenstände, Prozesse, Verhältnisse in der Natur thematisiert. Gleichwohl müssen wir diese Frage beantworten, da sonst der vielfältige Gebrauch, den wir heute vom Naturbegriff machen ‐ in lebensweltlichen, politischen, philosophischen Zusammenhängen ‐, ideologisch zu werden droht. Eine Antwort darf aber auch nicht ohne die Naturwissenschaft gegeben werden, vielmehr sind unsere traditionellen Naturvorstellungen auf der Basis der modernen Naturwissenschaft an vielen Stellen zu Korrigieren. Wenn es nun auch nicht möglich ist, auf der Basis der mannigfaltigen Naturwissenschaft ein Gesamtbild von der Natur zu entwerfen, so lassen sich doch einzelne charakteristische Züge (Charaktere) benennen. Der Begriff der Naturcharaktere, die auf der einen Seite hochaggregierte Erfahrungen mit der Natur enthalten und auf der anderen Seite als Heuristiken für weitere Forschung dienen, wird im folgenden Artikel erlätert und durch Beispiele illustriert.
Ökologische Chemie. Das schlechte Gewissen der Zivilisation oder Herausforderung für umwelttechnische Innovationen?
Authors: Bahadir Müfit 
Published: December 2004

AbstractIn diesem Aufsatz wird eine ganzheitliche Beschreibung der Aufgaben der ökologischen Chemie versucht und dabei der Bogen gespannt von den Quellen der Umweltkontamination, über das Verhalten von Stoffen in der Umwelt einschließlich in umweltrelevanten technischen Prozessen bis hin zu den methodischen Aspekten zur Erkennung adverser Effekte, um schließlich einen Ausblick auf ein umweltverträgliches Wirtschaften in der Hochtechnologie zu geben.
Chemie „nackter”︁ Moleküle. Oder das Massenspektrometer als Laboratorium
Authors: Schwarz Helmut 
Published: December 2004

AbstractDie moderne Massenspektrometrie bietet ein Methodenarsenal, das es gestattet, Detailfragen an isolierten Molekülen in einem Umfang und mit einer Genauigkeit zu beantworten, wie es vor wenigen Jahren noch undenkbar schien. Daß davon auch die Chemie in Lösung profitieren wird, ist vermutlich keine falsche Behauptung, lernen wir doch durch den Vergleich der Chemie eines isolierten Teilchens mit der des Moleküls in seiner „natürlichen”︁ Umgebung die Rolle dieser Umgebung erst richtig kennen.
Angewandte Biolumineszenz: Luciferasen in der biochemischen Analytik
Authors: Albrecht Steffen , Brandl Herbert , Schönfels Christoph , Adam Waldemar 
Published: December 2004

AbstractSelbstleuchtende Organismen faszinieren die Menschen seit Jahrtausenden. Trotz intensiver Forschung der Chemiker auf der ganzen Welt ist die effektive „Lichtproduktion”︁ dieser bemerkenswerten Lebewesen bis heute einmalig und unerreicht. Moderne molekularbiologische Methoden ermöglichen jetzt die gentechnische Synthese der interessantesten Luciferasen mit hoher Aktivität. Damit stehen diese für die Biolumineszenz entscheidenden Enzyme dem Analytiker endlich in ausreichender Menge, quasi im Reagenzglas, zur Verfügung und begünstigen damit die Anwendung biolumineszenter Systeme in der biochemischen und biomedizinischen Forschung. Ausgewählte Anwendungsbeispiele werden hier vorgestellt.
Kombinatorische Synthese
Authors: Frobel Klaus , Krämer Thomas 
Published: December 2004

AbstractIndustrial drug research is undergoing radical changes. Advances in molecular biology and gene technology have resulted in the development of test systems with which a very large number of substances can be screened for their biological activity. In order to keep pace with this high‐throughput screening procedure, preparative chemists need to reconsider conventional synthetic strategies.
Lichtblicke – Petrischalenexperimente in der Overhead‐Projektion
Authors: Full Roland 
Published: December 2004

AbstractOverhead projection with supplementary lenses provides „wallfilling big screen”︁ detailed pictures of physical and chemical phenomena and thus helps to train chemists to make accurate observations, comparisons, and interpretations. By using divided petri dishes, it is possible to present parallel and control experiments with minimal amounts of substances in one field of vision, and thus to establish the links between substance and reaction, and formula and equation. In particular, for the demonstration of electrochemical processes, the divided petri dish proves to be a projectable minimal system, which is characterized by maximum economy and ecology. Great recognition with little substance?.
Chemie und Liebe: ein Gleichnis
Authors: Soentgen Jens 
Published: December 2004

AbstractGoethe's nouel „Die Wahlverwandtschaften”︁ deals with a love‐story, but it also deals with chemistry. Goethe draws parallels between both chemical processes and the attraction of the characters. These parallels will be explained in detail in the essay. The essay also deals with Goethes knowledge of the chemical theory of his time and explains his subtle literary strategies.
Mathematikprogramm mit großem Funktionsumfang. Maple V Release 4, The Power Edition
Authors: Hecker Martin 
Published: December 2004

AbstractMaple ist ein mathematisches Werkzeug der vierten Generation. Nach Funktions‐ und Zahlentafeln, Rechenstäben und Taschenrechnern beherrschen heute Computeralgebrasysteme wie Maple V Release 4 das symbolische Rechnen.
Supermikroskopie bei organischen Kristallreaktionen
Authors: Kaupp Gerd 
Published: December 2004

AbstractSupermicroscopic techniques like STM, AFM and SNOM are able to image surfaces down to atomic resolution. Their application to chemically reacting rough organic surfaces leads to unprecedented results which do not accord with the topochemical principle of minimum molecular movement. Rather, feature‐forming long‐range molecular movements are essential for chemical reactivity. Thus, waste‐free solid‐state reactions proceed in three steps: phase rebuilding, phase transformation and crystal disintegration. Liquid phases are avoided in solid photochemical, solid thermal, gadsolid and solid/solid syntheses, the upscaling of which will provide the future chemical production techniques. Chemical contrast with SNOM is shown for the first time. It complements the AFM results which are interpreted in terms of crystal structure.
Organische Festkörperchemie, Teil II
Authors: Laschat Sabine 
Published: December 2004

AbstractAlthough the bond energies of weak non‐co‐valent interactions like hydrogen bonds, van der Waals forces and dipolar interactions are about 10–20 times smaller than those of covalent single bonds, the weak interactions can accumulate in the solid state, thus determining interesting physical and chemical properties of organic crystalline or polymeric solids, like inclusion of guest molecules, unprecedented solid state reactions, induced electric conductivity, resolution of racemates and photochemical‐thermal switches.
Vernetzte Gleichgewichte: Verhalten von lod gegenüber Petrolether, Wasser und Kaliumiodid
Authors: Wiskamp Volker , Wirth Mario 
Published: December 2004

AbstractBecause of the formation of KI3, potassium iodide increases the extraction rate of iodine from petroleum ether into water. Nernst's constant of the distribution of iodine in the system water/petroleum ether (KN = 34.1 ± 4.6) and the equilibrium constant of the formation of KI3 from iodine and potasium (KK = 820 ± 203 1 · mol−1) are determined by titration of I2 or KI3 in the separated organic and aqueous layers with thiosulfate standard solution. Aspects of environmental protection are an integral part of the experiments,e.g. iodine and petroleum ether are recycled.
Breite Qualifikation erforderlich. Zentrale Referentin für Arbeitssicherheit und Umweltschutz
Authors: Zimmermann Katrin 
Published: December 2004

AbstractOrganisation, Koordination sowie Druchsetzung von sicherheits‐technischen Maßnahmen bilden den Kern des Tätigkeitsfeldes der Zentralen Referentin für Arbeitssicherheit und Umweltschutz. Sie erfordern als Basis eine umfassende naturwissenschaftliche Ausbildung, so daß sich hier ein verantwortungsvoller Aufgabenbereich für Diplom‐Chemiker/innen auftut, bei dem es gilt, Personen‐ und Umweltschäden präventiv entgegenzutreten. Darüber hinaus ist ein sicherer Umgang mit der entsprechenden Rechtsmaterie unumgänglich.