bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute Stress May Facilitate Recovery from a Subcutaneous Bacterial Challenge
Authors: Deak Terrence , Nguyen Kien T. , Fleshner Monika , Watkins Linda R. , Maier Steven F. 
Published: April 2003

The effects of stress on the immune system vary with both the duration and type of stressor. Many studies suggest that stress may compromise an organism’s ability to recover from immune challenge. However, recent findings suggest that stress may actually enhance some aspects of immune function. For example, exposure to a single session (∼2 h) of intermittent inescapable tailshocks (IS) has been shown to activate the acute phase response and increase some aspects of macrophage function. Thus, the following experiments assessed whether IS exposure would alter local inflammation produced by peripheral injection of streptomycin-killed bacteria. Rats (Harlan Sprague Dawley) were exposed to IS (100 1.6-mA, 60 s variable intertrial interval) and injected with <i>Escherichia coli</i> (∼2.5 × 10<sup>8</sup> CFU s.c. posterior to the shoulder blades). The area of inflammation was measured until the inflammation had completely resolved (typically 7–8 days). When bacteria were administered immediately after IS, rats resolved inflammation significantly faster than did nonstressed rats. Since adrenalectomy did not reduce the effect of IS, it is unlikely that this effect is a result of elevated corticosterone levels. Furthermore, IS does not appear to alter the rat’s ability to sequester bacteria in the subcutaneous space since no swelling of lymph nodes or chronic activation of the hypothalamic-pituitary-adrenal axis was observed.
Recombinant Forms of the Neurotrophic Factor Pigment Epithelium-Derived Factor Activate Cellular Metabolism and Inhibit Proliferation of the RAW Macrophage Cell Line
Authors: Cohen Joseph , Sugita Yukihiro , Chader Gerald J. , Schwartz Joan P. 
Published: April 2003

Recombinant forms of the neurotrophic factor pigment epithelium-derived factor (PEDF) activate metabolism of RAW macrophage cells while simultaneously inhibiting their proliferation. The recombinant forms (rPEDF) acted with EC<sub>50</sub>s of 0.1–1 n<i>M</i> while full-length native bovine PEDF was inactive. Urea, which is the buffer used to extract recombinant PEDF, stimulated RAW cell proliferation, the first report of an effect of urea on non-kidney cells. PEDF acted within 12 h and its effects persisted up to 72 h with continuous exposure. Although rPEDF had no direct action on glioma cell lines, it increased the amount of a soluble factor released by RAW cells which was capable of blocking glioma cell division. Thus PEDF may function as a neuroimmune modulator, affecting both neural and immune system cells.
Suppression of Lymphocyte Mitogenesis by Tamoxifen: Studies on Protein Kinase C, Calmodulin and Calcium
Authors: Baral Edward , Nagy Eva , Kwok Siuchan , McNicol Archibald , Gerrard Jon , Berczi Istvan 
Published: April 2003

The effect of tamoxifen (TX; 1.0 μ<i>M</i>) on the mitogenic response of rat lymphocytes was compared with the effect of drugs that are known to act on protein kinase C (PKC), calmodulin (CM), and calcium (Ca<sup>2+</sup>). The calcium ionophore A23187 (0.2 μ<i>M</i>) was mitogenic on its own which was not influenced by TX. The agents modulating PKC or CM (phorbol-myristate-13-acetate; R24571, chlorpromazine) influenced mitogenesis differently than did TX. General inhibition of lymphocyte proliferation was seen with the Ca<sup>2+</sup> antagonist agents (EGTA, TMB-8) as with TX. The antiproliferative effect of TX was partially reversed by the increase of Ca<sup>2+</sup> in the culture medium when T cell mitogens were used, but not in the case of lipid A, a B lymphocyte mitogen. However, the concanavalin A-induced Ca<sup>2+</sup> influx was further elevated by TX which differed from the effect of the Ca<sup>2+</sup> channel-blocking agent verapamil. The results suggest that TX resets the threshold stimulus necessary for mitogenesis and is completely reversible.
Time of Day-Dependent Effects of Thyroliberin and Thyrotropin on Thymocyte Proliferation in Rats
Authors: Winczyk Katarzyna , Pawlikowski Marek 
Published: April 2003

Our earlier studies have shown that thyroliberin (TRH) as well as thyrotropin (TSH) enhanced thymus cell proliferation. The aim of the present study was to investigate whether the effects of TRH and TSH on thymocyte proliferation depend on time of day. A single subcutaneous injection of TRH (25 μg/animal) or TSH (3 IU/animal) was made at 9:00 h (1 h after light onset) or at 18:00 h (10 h after light onset) in 3-month-old male Wistar rats. The animals were killed 24 h later. The proliferation of thymocytes was assessed by incorporation of bromodeoxyuridine into cell nuclei. Thymocyte proliferation was significantly increased by TSH administration at 9:00 h, whereas treatment given at 18:00 h was ineffective. TRH enhanced the proliferation when injected at 9:00 h, but had an inhibitory effect when administered at 18:00 h. These data indicate that the effects of TRH and TSH on thymocyte proliferation are dependent on time of day.
Human Amylin Stimulates Inflammatory Cytokine Secretion from Human Glioma Cells
Authors: Gitter Bruce D. , Cox Laura M. , Carlson Christopher D. , May Patrick C. 
Published: April 2003

Chronic neurodegeneration in the brains of Alzheimer’s disease (AD) patients may be mediated, at least in part, by the ability of amyloid beta (Aβ) to exacerbate inflammatory pathways in a conformation-dependent manner. In this regard, we previously reported that the Aβ-peptide-mediated potentiation of inflammatory cytokine secretion from interleukin-1β (IL-1β)-stimulated human astrocytoma cells was conformation dependent. Other amyloidogenic peptides, such as human amylin, which display similar conformation-dependent neurotoxic effects, may also elicit inflammatory cytokine secretion from glial cells. To test this hypothesis, we compared human and rat amylin for the effects on cytokine production in U-373 MG human astrocytoma cells. Human amylin alone stimulated U-373 MG cells to secrete IL-6 and IL-8 in a concentration-dependent manner with maximum effects seen at 10–25 μ<i>M</i> peptide. In addition, human amylin markedly potentiated IL-1β-stimulated cytokine production with a similar concentration dependence. In contrast, nonamyloidogenic rat amylin modestly stimulated cytokine secretion, either alone or combined with IL-1β. Aging human amylin resulted in diminished cytokine secretion, probably due to the formation of large, less active aggregates. In agreement with our previous studies using Aβ, extracellular Ca<sup>2+</sup> was necessary for human amylin stimulation of cytokine secretion. Our data suggest that amyloidogenic peptides promote cytokine secretion through similar β-sheeted secondary-structure- and extracellular-Ca<sup>2+</sup>-dependent mechanisms.
Modulation of IL-18 Production in the Adrenal Cortex following Acute ACTH or Chronic Corticosterone Treatment
Authors: Conti Bruno , Sugama Shuei , Kim Yoonseong , Tinti Cristina , Kim Hocheol , Baker Harriet , Volpe Bruce , Attardi Barbara , Joh Tong 
Published: April 2003

Interleukin (IL)-18 is a proinflammatory cytokine and a stimulator of cell-mediated immune responses. We have previously reported that acute stress stimulates the production of IL-18 mRNA in the glucocorticoid (GC)-producing cells of the adrenal cortex. In order to investigate the mechanisms governing the expression of IL-18 in the adrenal cortex, the effects of acute ACTH or chronic corticosterone treatment on the levels of IL-18 mRNA and protein were examined by in situ hybridization and Northern and Western blot assays. Adult male Sprague-Dawley rats received a subcutaneous injection of ACTH or subcutaneous implantation of slow-release corticosterone pellets followed by an injection of saline or ACTH. After 4 h, ACTH induced a 4-fold increase in IL-18 mRNA levels and elevated the content of pro-IL-18 peptide. Six days of chronic corticosterone treatment did not alter the basal levels of IL-18 mRNA and reduced those of pro-IL-18. Finally, ACTH treatment of animals under the corticosterone regimen induced a 2-fold increase in IL-18 mRNA and elevated the levels of the pro-IL-18 protein. The levels of the precursor, p45, and the active subunit p10 peptides of the IL-18-processing enzyme, IL-1β-converting enzyme (ICE), showed no substantial differences in all the conditions tested. IL-1β was not detected under these experimental conditions. These data demonstrate that the production of IL-18 in the adrenal cortex is stimulated by ACTH treatment and is not inhibited by the direct action of corticosterone. In contrast to the anti-inflammatory action of GCs, IL-18 may have an immunostimulatory role during acute stress.
Effects of Thyrotropin-Releasing Hormone on the Sleep EEG and Nocturnal Hormone Secretion in Male Volunteers
Authors: Hemmeter U. , Rothe B. , Guldner J. , Holsboer F. , Steiger A. 
Published: April 2003

Various peptides including corticotropin-releasing hormone (CRH) exert selective effects on sleep structure and noctural secretions of cortisol and growth hormone (GH). In animal studies analeptic effects and sleep disturbances after thyrotropin-releasing hormone (TRH) administration have been observed; studies of endocrine function in depressed patients suggest a pathological activity of CRH and TRH as compared with that in healthy volunteers. As the role of TRH in the regulation of the sleep endocrine pattern in humans has not yet been clarified, we performed a study to examine the effects of pulsatile administration of TRH on the sleep EEG pattern and the nocturnal secretions of cortisol and GH in 7 healthy male subjects. The sleep EEG was recorded from 23.00 to 07.00 h, and blood samples were collected every 20 min from 20.00 to 07.00 h for the analysis of GH and cortisol concentrations during intravenous administration of placebo or 4 × 50 µg TRH at 22.00, 23.00, 24.00, and 01.00 h. In contrast to the well-known effects of CRH on the sleep endocrine pattern, TRH exerts only a weak effect on the sleep EEG which is reflected in a slight decrease in sleep efficiency associated with a trend to wakefulness during the night. Furthermore, after TRH administration, the cortisol rise appeared earlier, and a nonsignificant tendency to an increased secretion of cortisol during the first half of the night was found. The GH secretion did not differ significantly after application of TRH or placebo. The activating, albeit weak, effect of TRH on the sleep EEG and nocturnal cortisol secretion in healthy volunteers confirms and adds to the results previously observed in animals. On the basis of these findings, we surmise that TRH may contribute to the disturbed sleep continuity seen in depressed patients, probably acting as a cofactor of CRH in a synergistic manner.
Impairment of the Correlation between Urinary Contents of Alpha-1-Microglobulin and Ulinastatin Is Induced by Intracerebroventricularly Administered Interleukin-6 in Mice
Authors: Kaku Koichi , Shikimi Tadahiro , Inagaki Takuji , Ishino Hiroshi , Okunishi Hideki , Takaori Shuji 
Published: April 2003

We have found previously that the correlation between urinary contents of alpha-1-microglobulin (α1M) and ulinastatin (UT) depends on the type of neuropsychiatric disease. Since interleukin (IL)-1β and IL-6 are closely involved in pathophysiological aspects of various neuropsychiatric diseases, effects of intracerebroventricularly (i.c.v.) administered IL-1β and IL-6 on the correlation between urinary contents of these two glycoproteins were examined in mice, a species in which α1M and UT and also the correlation between the urinary contents thereof are expressed similarly to humans. Indices (volume, contents of creatinine, α1M and UT, and α1M/UT ratio) in urine collected after i.c.v. administrations of 2 and 20 ng of either IL-1β or IL-6 were not statistically different from those of the vehicle-treated (control) groups. Neither IL-1β (2 and 20 ng) nor the lower dose of IL-6 (2 ng) affected the positive correlation between urinary contents of α1M and UT. However, a higher dose of IL-6 (20 ng) nullified the positive correlation for 2 days after administration. Recovery to a positive correlation was thereafter displayed. These findings suggest that central IL-6 plays an important role in correlating urinary contents of α1M and UT without affecting the renal functions.
Policosanol, Reaction Time and Event-Related Potentials
Authors: Fontani Giuliano , Maffei Domenico , Lodi Leda 
Published: April 2003

The aim of the present study was to compare the results of a 1-week, double-blind placebo-controlled trial investigating the effects of isopolicosanol and octacosanol on reactivity and related brain activity. In particular, reaction time (RT) and event-related potentials such as contingent negative variations (CNV) and P300 (P3) have been studied. Thirty sedentary healthy students were tested before and after treatment (3.6 mg/die for 7 days) with orally administered tablets of placebo (group A), isopolicosanol (B) and octacosanol (C). RT were studied according to three procedures: simple RT (SRT), go/no-go RT (GRT) and choice RT (CRT). Results show that before treatment, there were no significant differences between groups A, B and C. After treatment, the RT of group A was unchanged, while the RT of groups B and C were reduced. In group B, in the SRT test, the reduction of RT was accompanied by electrical data exhibiting increased amplitudes of CNV and shorter latencies of P3. These results show that the main effect on reactivity and event-related potentials can be ascribed to policosanol and is mainly evident in the SRT test.
Effects of Antidepressants on γ-Aminobutyric Acid- and N-Methyl-<i>D</i>-Aspartate-Induced Intracellular Ca<sup>2+</sup> Concentration Increases in Primary Cultured Rat Cortical Neurons
Authors: Takebayashi Minoru , Kagaya Ariyuki , Inagaki Masatoshi , Kozuru Tosiro , Jitsuiki Hiroaki , Kurata Kenichi , Okamoto Yasumasa , Yamawaki Shigeto 
Published: April 2003

We investigated the effects of antidepressants on the intracellular Ca<sup>2+</sup> concentration ([Ca<sup>2+</sup>]<sub>i</sub>) increases induced by γ-aminobutyric acid (GABA) or N-methyl-D-aspartate (NMDA) in primary cultured rat cortical neurons using fluorescence imaging. Acute treatment with imipramine inhibited GABA- and NMDA-induced increases in [Ca<sup>2+</sup>]<sub>i</sub> in a concentration-dependent manner. Doses of 30 μ<i>M</i> clomipramine, desipramine, amoxapine and maprotiline also inhibited both the GABA- and NMDA-induced [Ca<sup>2+</sup>]<sub>i</sub> increases significantly. Both inhibitory effects of the five major antidepressants on the GABA- or the NMDA-induced [Ca<sup>2+</sup>]<sub>i</sub> increases were well-correlated. Imipramine could inhibit significantly high-K<sup>+</sup>-induced [Ca<sup>2+</sup>]<sub>i</sub> increases. Our previous study has already shown that the GABA-induced [Ca<sup>2+</sup>]<sub>i</sub> increase involves a similar pathway to high-K<sup>+</sup>-induced Ca<sup>2+</sup> influx. In conclusion, imipramine and several other antidepressants have acute inhibitory effects on the GABA-, NMDA- and high-K<sup>+</sup>-induced [Ca<sup>2+</sup>]<sub>i</sub> increases, suggesting that these inhibitory effects are not related to specific receptors. One possibility is that these effects may be commonly mediated via part of the high-K<sup>+</sup>-induced [Ca<sup>2+</sup>]<sub>i</sub> pathway.
Technik und Resultate der Hammergriffstapedektomie
Authors: Oestreicher E. , Häusler R. 
Published: April 2003

<b>Fragestellung:</b> Retrospektive Evaluation der Hammergriffstapedektomie in bezug auf Indikation, Operationstechnik, postoperativen Verlauf und Hörresultate. <b>Patienten und Methoden:</b> Zwischen 1992 und 1998 wurden an der Klinik für HNO, Hals- und Kopf-Chirurgie des Inselspitals in Bern vom Senior-Autor 44 Hammergriffstapedektomien an 40 Patienten durchgeführt. Bei 31 Patienten (71%) handelte es sich um einen Revisionseingriff, welcher wegen zusätzlicher Ankylose von Incus und/oder Hammerkopf (n = 8), Nekrose des langen Incusfortsatzes (n = 6), Luxation der Incus (n = 3) oder nach vorangegangener Fenestration (n = 4) durchgeführt wurde. In 6 Fällen wurde der Eingriff nach verschiedenen anderen Ohroperationen durchgeführt, z.B. nach vorangegangener Incusinterposition bei fixiertem Stapes. Eine primäre Hammergriffstapedektomie wurde bei 13 Patienten (29%) wegen kongenital oder entzündlich fixiertem Amboss und/oder Hammerkopf zusätzlich zur Steigbügelfixierung durchgeführt. In 4 Fällen handelt es sich um eine Revision bzw. eine Zweitrevision einer Hammergriffstapedektomie. Die Hammergriffstapedektomie wurde transkanalär unter Lokalanästhesie durchgeführt unter Benützung des Skeeter-Mikrodrills und des Argon-Lasers. Eingesetzt wurden überlange Draht-Teflonpiston-Prothesen, die unter Verwendung von Zement am Hammergriff fixiert wurden. <b>Ergebnisse:</b> 39 Patienten konnten nachkontrolliert werden. 36 Patienten (92%) hatten postoperativ ein verbessertes Gehör mit einem positiven Stimmgabeltest nach Rinne. Der mittlere residuelle Air-bone gap bei 0,5, 1, 2 und 3 kHz betrug in 40% der Fälle ≤10 dB und in 85% der Fälle ≤20 dB. Ein Patient entwickelte einige Wochen nach der Hammergriffstapedektomie einen hochgradigen Innenohrhörverlust mit vorübergehenden Schwindelanfällen, wahrscheinlich aufgrund eines aus dem ovalen Fenster gesprungenen Pistons. <b> Schlussfolgerungen:</b> Verglichen mit den Resultaten nach der üblichen primären Incusstapedektomie sind die Resultate nach der Hammergriffstapedektomie weniger gut, aber die Technik hat sich als relativ sicher erwiesen und erlaubt in den meisten Fällen einen Hörgewinn. Moderne technische Mittel, wie überlange Draht-Teflonpiston-Prothesen, die Benützung des Skeeter-Mikrodrills und des Argon-Lasers mit fiberoptischem Mikrohandstück sowie der Einsatz von Zement erwiesen sich als besonders nützlich bei diesen chirurgisch heiklen Eingriffen.
Neurektomie des Nervus singularis nach Gacek
Authors: Häusler Rudolf , Marchal Francis 
Published: April 2003

<b>Fragestellung:</b> Evaluation der Wirksamkeit der Neurektomie des Nervus singularis nach Gacek bei Patienten, die an chronisch persistierendem paroxysmalem Lagerungsschwindel leiden. <b>Patienten und Methodik:</b> Zwischen 1980 und 1998 wurde bei 14 Patienten, die an chronisch persistierendem paroxysmalem Lagerungsschwindel (Symptomdauer 1–15 Jahre, mittlere Dauer 5 Jahre) litten, eine selektive Singularisneurektomie unter Lokalanästhesie durch transkanalären Zugang durchgeführt. Zusätzlich wurden die Variationen des anatomischen Verlaufs des N. singularis und seine Beziehung zum runden Fenster anhand von Bohrungen in Felsenbeinpräparaten studiert. <b>Ergebnisse:</b> 13 (93%) von den 14 operierten Patienten waren nach dem Eingriff von ihrem Lagerungsschwindel befreit. Während des Eingriffs konnte der N. singularis allerdings nur bei 3 Patienten eindeutig identifiziert und durchtrennt werden. Bei 9 weiteren Patienten provozierte die Bohrung unter dem runden Fenster plötzlich ein Schwindelgefühl mit einem vertikalen, nach unten schlagenden Nystagmus, was ebenfalls als Zeichen einer Durchtrennung des N. singularis gedeutet wurde. Bei 1 Patientin kam es zu einer zusätzlichen Innenohreröffnung mit postoperativem Hörverlust. Dieser Hörverlust war die einzige Komplikation bei den 14 operierten Patienten. Bei 1 Patienten konnte der N. singularis nicht identifiziert werden, und der Eingriff wurde abgebrochen. Dieser Patient wurde später durch eine Okklusion des hinteren Bogengangs vom Lagerungsschwindel befreit. <b>Schlussfolgerung:</b> Die Ergebnisse unserer Studien bestätigen die Resultate von Gacek und anderen Autoren, wonach die selektive Neurektomie des N. singularis ein wirksamer und wenig invasiver Eingriff ist, um chronisch persistierenden und rezidivierenden Lagerungsschwindel definitiv zu heilen.
Der Einfluss der Stapesfussplattenfläche auf den Druck in der Perilymphe und die Auslenkung der Basilarmembran
Authors: Arnold W. , Böhnke F. , Scherer E. 
Published: April 2003

Bei Steigbügeloperationen hängt die Qualität der Resultate einerseits von Geschick und Erfahrung des Operateurs, andererseits aber auch von der Art der verwendeten Prothese ab. Eine statistische Auswertung der qualitativen Ergebnisse von Stapedektomien und Stapedotomien ergab, dass der postoperative Knochenleitungsgewinn bei der Stapedektomie im Frequenzbereich von 1–2 kHz um etwa 8 dB höher ist. <i>Methode:</i> Um eine optimale Prothese zu entwickeln, wird eine numerische Simulation der Mechanik der Koppelstelle zwischen der Stapesfussplatte und der Perilymphe der Cochlea in drei Dimensionen vorgenommen, die zu einer speziellen Geometrie der Grenzfläche zwischen der Prothese und der angekoppelten Perilymphe führt. <i>Resultate:</i> Die Resultate zeigen, dass eine Vergrösserung der Stapesfussplattenfläche eine Erhöhung des Drucks in der Perilymphe bewirkt. Da dies auch eine Zunahme der maximalen Auslenkung der Basilarmembran zur Folge hat, wäre eine weitere Verbesserung der Knochenleitung nach Stapedektomie bei Otosklerose mit bereits vorliegender Innenohrdepression mit einer entsprechend verbesserten Prothesenform zu erwarten.
Funktionelle und morphologische Zweiteilung der Eustachi-Röhre
Authors: Mulder J.J.S. , Peters T.A. , Tonnaer E.L.G.M. , Kuijpers W. 
Published: April 2003

Vom histologischen Aufbau der Eustachi-Röhre können deren Grundfunktionen (Schutz, Reinigung und Belüftung) abgeleitet werden. Neuere systematische histologische und Mikroschnittuntersuchungen sowie embryologische Untersuchungen zur Entwicklung der Tuba auditiva führten zu Ergebnissen, die unsere Einsicht in die Funktion der Eustachi-Röhre vertieft haben. Diese Befunde sind: 1. Squamöses, nicht sekretorisches Epithel kommt nur im dorsalen Teil der Tube vor. 2. Die Öffnungsmuskeln der Tube setzen ausschliesslich am dorsalen Abschnitt an. 3. Zur Zeit der Geburt ist lediglich das mukoziliare Epithel ausgereift. Das dorsale, squamöse hingegen erst kurz vor der Belüftung des Mittelohres (10 Tage postpartal). Diese Befunde führten zum Konzept der räumlich-funktionellen Zweiteilung des Tubenepithels: Der dorsale Teil spielt eine Rolle bei der Belüftung des Mittelohres, der ventrale dient der Clearance.