bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing use of gonadotropin‐releasing hormone agonists for the treatment of localized prostate carcinoma
Authors: Shahinian Vahakn B. , Kuo Yong‐fang , Freeman Jean L. , Orihuela Eduardo , Goodwin James S. 
Published: March 2005

AbstractBACKGROUNDThe role of androgen deprivation therapy in prostate carcinoma is controversial in earlier stages of disease. The authors examined the time trends and patterns of use for androgen deprivation in the form of gonadotropin‐releasing hormone (GnRH) agonists or orchiectomy, in population‐based tumor registries.METHODSData were obtained from the linked Surveillance, Epidemiology and End Results‐Medicare database. A total of 100,274 men with prostate carcinoma diagnosed from 1991 through 1999 were selected. The main outcome was the proportion of men who received ≥ 1 dose of a GnRH agonist in the first 6 months of diagnosis. This was plotted by year and stratified for age, grade, stage as well as primary versus adjuvant usage. Multiple logistic regression was used to examine predictors of GnRH agonist use in the subset of patients with localized cancer.RESULTSThere was a consistent increase in GnRH agonist use by year for all ages, stages, and grades. Even in men ≥ 80 years with localized stage and low to moderate grade tumors, primary GnRH agonist use increased over the study period, from 3.7% in 1991 to 30.9% in 1999 (P < 0.001). The multivariable analysis showed that significant variability in GnRH agonist use existed among SEER geographic regions.CONCLUSIONSThe use of GnRH agonists for prostate carcinoma increased dramatically during the 1990s. This increase occurred across all stages and histologic grades of prostate carcinoma, and was greatest in patients ≥ 80 years. Cancer 2005. © 2005 American Cancer Society.
Use of tamoxifen in advanced‐stage hepatocellular carcinoma
Authors: Nowak Anna K. , Stockler Martin R. , Chow Pierce K. H. , Findlay Michael 
Published: March 2005

AbstractBACKGROUNDHepatocellular carcinoma (HCC) is the third most common cause of cancer mortality worldwide. Survival is poor for patients with advanced‐stage HCC, and small trials of tamoxifen for patients with this disease have shown conflicting results. The authors conducted a systematic review of randomized clinical trials to compare the effect of a tamoxifen‐containing arm with a nontamoxifen‐containing arm in advanced HCC.METHODSEligible trials were identified from the Cochrane Hepato‐Biliary Group register and other databases. Studies were selected for inclusion and their methodologic quality assessed by three independent reviewers. Hazard ratios (HR) were derived for overall survival where possible. Metaanalysis was performed using a fixed‐effect model.RESULTSThe authors identified 10 randomized trials with a total of 1709 patients. Use of tamoxifen had no effect on median survival (HR, 1.05; 95% confidence interval, 0.94–1.16; P = 0.4) or tumor response rate. The findings were stable in sensitivity analyses and were not affected by publication bias or inclusion of low‐quality studies or studies reported in abstract form only. Few adverse events or withdrawals were noted.CONCLUSIONSThere was no support for the therapeutic use of tamoxifen in advanced HCC, nor for its use as a control arm in future clinical trials. Cancer 2005. © 2005 American Cancer Society.
Prinzipielle Beobachtungen zu Bauweise und Verfall der Gewölbe in den Tempeln von Angkor in Kambodscha
Authors: Pfefferkorn Stephan , Leisen Hans 
Published: March 2005

AbstractWährend der Blüte der Khmer‐Kultur entstanden in der Zeit von um 800 bis um 1300 n. Chr. auf dem Gebiet des heutigen Kambodscha und Thailand beeindruckende Tempelanlagen. Eine bedeutende Konzentration dieser Bauten stellt das heutige Angkor im Zentrum Kambodschas unweit des Sees Tonle Sap dar. Je nach Stilperiode dominieren als Baumaterial Ziegel, Laterit oder Sandstein. Die zum Teil recht unterschiedlichen Formen der einzelnen Gebäudeteile der Tempelanlagen besitzen eine Gemeinsamkeit. Für den oberen Abschluß ihrer Türme, lang gestreckten Galerien, Bibliotheks‐ und Torbauten wählten deren Baumeister das Prinzip der Kragwölbung. Heute sind große Teile der Gewölbe vor allem der langgestreckten Galerien bereits eingestürzt bzw. stark geschädigt. Die folgenden Untersuchungen sollen diese Bauweise der Khmer näher beleuchten und einen Beitrag dazu leisten, das Tragverhalten der Gewölbe im Zusammenhang mit deren Unterkonstruktionen besser zu verstehen, um die Ursachen der Schäden sicherer herauszufinden und auf sicherer Basis Maßnahmekonzepte zur Sanierung zu entwickeln. Die Grundlage für diese Betrachtungen bildet ein Arbeitsaufenthalt der Autoren in Angkor im Februar 2000, der – thematisch in das vom Auswärtigen Amt Deutschlands finanzierte und von der Fachhochschule Köln geleitete German Apsara Conservation Project (GACP) eingebettet – von der Deutschen Forschungsgemeinschaft unterstützt wurde.
Der Wand‐Decken‐Knoten im Mauerwerksbau: Teil 1: Theoretische und experimentelle Untersuchungen zur Tragfähigkeit
Authors: Jäger Wolfram , Baier Gunar 
Published: March 2005

AbstractDer Wand‐Decken‐Knoten hat bei der Bemessung von Mauerwerk eine markante Bedeutung, da infolge der Verdrehung der Geschoßdecken in die Wände Biegemomente übertragen werden, die wiederum die Tragfähigkeit der Wand nachhaltig beeinflussen. Um den Arbeitsaufwand für deren Ermittlung in Grenzen zu halten, wird die Berechnung des Rahmensystems aus Wänden und Decken i. d. R. auf Ein‐Knoten‐Systeme zurückgeführt, die jeweils am Kopf und am Fuß der Wand angesetzt werden. Auf diese Weise läßt sich gleichzeitig die Lagerung der Wand an diesen Stellen berücksichtigen. Einer möglichst realitätsnahen Bestimmung der infolge Behinderung der Deckenverdrehungen indizierten Biegemomente und somit der Lastexzentrizität in der Wand kommt eine besondere Bedeutung bei der Bemessung zu. Die Güte der Modellierung und die zugrunde gelegten Annahmen haben Einfluß auf das rechnerische Ergebnis, das mehr oder weniger von dem realen Verhalten und der tatsächlichen Tragfähigkeit abweicht. Es soll auf der sicheren Seite liegen sowie einfach und schnell zu bestimmen sein.Das Verhalten des Wand‐Decken‐Knotens ist mit besonderem Bezug zum Eurocode 6 theoretisch, experimentell und numerisch untersucht worden, um ggf. vorhandene Reserven beim Übergang auf das neue Sicherheitskonzept offenlegen und ausnutzen zu können. Die wesentlichen Ergebnisse werden nachfolgend dargestellt.
Zur Einführung der DIN 1053‐100: Mauerwerk – Berechnung auf der Grundlage des semiprobabilistischen Sicherheitskonzepts
Authors: Jäger Wolfram 
Published: March 2005

AbstractIm August 2004 ist die DIN 1053‐100 [1] zur Berechnung von Mauerwerk nach dem neuen Sicherheitskonzept erschienen. Sie gestattet die Berechnung und Bemessung von Mauerwerksbauten mit Hilfe von Teilsicherheitsfaktoren. Dabei wurden die Nachweise von der Spannungs‐ auf die Kraftebene umgestellt. Im Zuge der Endfassung sind gegenüber bisherigen Veröffentlichungen aus der Erarbeitungsphase (s. [2] u. [3]) noch Veränderungen vorgenommen worden. Die Aufnahme in die Musterliste der Technischen Baubestimmungen [4] soll im Februar 2005 erfolgen, wobei eine Einschränkung hinsichtlich der Größe der zugelassenen Außermittigkeit im Gebrauchszustand unter vertikaler Belastung ergänzt wird. Der Beitrag stellt die wesentlichen Veränderungen vor und informiert über deren Hintergründe.
Mauermörtel und Putzmörtel nach europäischer Norm
Authors: Riechers Hans‐Joachim 
Published: March 2005

AbstractHeute werden in den Bereichen “Mauermörtel” und “Putzmörtel” praktisch ausschließlich Werkmörtel eingesetzt. Diese Mörtel unterliegen bei der Herstellung einer strengen Qualitätskontrolle. Verantwortlich dafür ist der Hersteller selbst. Daran ändern Normen und Festlegungen des Bauordnungsrechts nichts. Die Normen legen jedoch Begriffe, Bezeichnungen und Klasseneinteilungen fest, mit denen die Kommunikation zwischen Planern, Herstellern und Bauausführenden erleichtert wird. Deshalb ist es wichtig, daß alle am Mauerwerksbau Beteiligten über den neuesten Stand informiert sind. Die Umstellung auf europäische Normen hat zu einigen Änderungen geführt, die im folgenden – in Kurzform – erläutert werden.
Bemessung von horizontal beanspruchtem Mauerwerk nach prEN 1996‐1‐1 mit Hilfe modifizierter Momentenverteilungszahlen
Authors: Jäger Wolfram , Thieme Mike 
Published: March 2005

AbstractHorizontal beanspruchte Wände treten im Mauerwerksbau in Deutschland in Form von Ausfachungswänden mit Windbelastung bzw. Kellerwänden mit Erddruckbelastung auf. Diese werden nach DIN 1053‐1 [1] bisher mit Hilfe von Tabelle 9 auf ihre zulässige Größe hin überprüft. Bei Kellerwänden kann ein ausführlicher, rechnerischer Nachweis entfallen, wenn über einen Grenzlastvergleich das angenommene Bogenmodell sichergestellt ist.In der aktuellen Fassung des EC 6 [2] werden für die Bemessung von Mauerwerk bei Plattenbeanspruchung zwei Rechenmodelle angeboten, das Bogenmodell und das Plattenmodell. Ersteres läßt sich nur bei zutreffenden Randbedingungen, die die Ableitung des Bogenschubs garantieren, anwenden. Bei dem Plattenmodell wird die Momentenverteilung in Anlehnung an die Bruchlinientheorie des Stahlbetonbaus bestimmt und der Biegenachweis unter Ansatz der Elastizitätstheorie geführt. Die Vorteile dieses Bemessungsmodells gegenüber DIN 1053‐1 sind die einfache Berücksichtigung baustofflicher und geometrischer Gegebenheiten und die genauere Nachweisführung.Bei Untersuchungen zur Einführung des EC 6 in Deutschland wurde festgestellt, daß in bestimmten Parameterbereichen die in ENV 1996‐1‐3 [4] bisher zu findenden Momentenverteilungszahlen eine ungenügende Übereinstimmung mit Wandversuchen zeigen und ein Sicherheitsrisiko bei der Anwendung darstellen. Auf der Basis numerischer Analysen und begleitender Versuche zur Kalibrierung konnten die bestehenden Diskrepanzen beseitigt und modifizierte Momentenverteilungszahlen erarbeitet werden [4]. Der Beitrag informiert über die durchgeführten Untersuchungen und die ereichten Ergebnisse.
HPRT mutations, TCR gene rearrangements, and HTLV‐1 integration sites define in vivo T‐cell clonal lineages
Authors: Allegretta Mark , Ardell Stephanie K. , Sullivan Linda M. , Jacobson Steven , Mortreux Franck , Wattel Eric , Albertini Richard J. 
Published: March 2005

AbstractHPRT mutations in vivo in human T‐lymphocytes are useful probes for mechanistic investigations. Molecular analyses of isolated mutants reveal their underlying mutational changes as well as the T‐cell receptor (TCR) gene rearrangements present in the cells in question. The latter provide temporal reference points for other perturbations in the in vivo clones as well as evidence of clonal relationships among mutant isolates. Immunological studies and investigations of genomic instability have benefited from such analyses. A method is presented describing a T‐cell lineage analysis in a patient with HTLV‐1 infection. Lineage reconstruction of an in vivo proliferating HPRT mutant clone allows timing of the integration event to a postthymic differentiated cell prior to the occurrence of HPRT mutations. Environ. Mol. Mutagen., 2005. © 2005 Wiley‐Liss, Inc.
Role of infectious diseases in human carcinogenesis
Authors: Herrera Luis A. , Benítez‐Bribiesca Luis , Mohar Alejandro , Ostrosky‐Wegman Patricia 
Published: March 2005

AbstractThe burden of human infectious diseases remains a public health problem worldwide. At least 2 billion people are affected by viral infections, and a similar number by bacteria or helminths. The long‐term effects of these maladies have raised particular concern since some infectious agents have been associated with chronic human diseases, especially cancer. It is estimated that 13–20% of the world cancer cases are associated with some virus, bacteria, or helminth, e.g., human papillomavirus,Helicobacter pylori, andSchistosoma haematobiumthat cause cervical, stomach, and urinary bladder cancer, respectively. Certain associations between infection and malignancy are strong and irrefutable; others are still speculative. This article reviews the infectious agents that have been associated with cancer and current knowledge about the mechanisms underlying these associations. Environ. Mol. Mutagen., 2005. © 2005 Wiley‐Liss, Inc.
Is the hippocampal theta rhythm related to cognition in a non‐locomotor place recognition task?
Authors: Kelemen Eduard , Morón Ignacio , Fenton André A. 
Published: March 2005

AbstractThe possible correlation of 4–12 Hz hippocampal field oscillations (theta rhythm) with motor and cognitive behavior was studied by recording the hippocampal electroencephalogram in non‐locomoting rats as they solved a hippocampus‐dependent place recognition task. The electroencephalogram (EEG) during the place recognition task was compared with the EEG during a control task, which had the same motor demands but did not require place recognition. In the place recognition task, the rat was passively transported on the periphery of a circular rotating arena, operant responses (lever pressing in Experiment 1 and licking in Experiment 2) emitted in a 60° reward sector of the arena trajectory were reinforced. As expected the theta rhythm was observed during “voluntary” movements such as walking and lever pressing. During walking and lever pressing, when prominent theta was observed, the frequency increased within the first 10 min of a session. When the rats were not moving, during licking or staying motionless, both the theta amplitude and frequency were lower compared with the EEG during walking. There were no correlations between any theta characteristics and cognitive demand of the tasks. © 2005 Wiley‐Liss, Inc.
Tetrodotoxin infusions into the dorsal hippocampus block non‐locomotor place recognition
Authors: Klement Daniel , Pašt'alková Eva , Fenton André A. 
Published: March 2005

AbstractThe hippocampus is critical for navigation in an open field. One component of this navigation requires the subject to recognize the target place using distal cues. The experiments presented in this report tested whether blocking hippocampal function would impair open field place recognition. Hungry rats were trained to press a lever on a feeder for food. In Experiment 1, they were passively transported with the feeder along a circular trajectory. Lever pressing was reinforced only if the feeder was passing through a 60°‐wide sector. Thus, rats preferentially lever pressed in the vicinity of the reward sector indicating that they recognized its location. Tetrodotoxin (TTX) infusions aimed at the dorsal hippocampi caused rats to substantially increase lever pressing with no preference for any region. The aim of Experiment 2 was to determine whether the TTX injections caused a loss of place recognition or a general increase of lever pressing. A separate group of rats was conditioned in a stationary apparatus to press the lever in response to a light. The TTX injections did not abolish preferential lever pressing in response to light. Lever pressing increased less than half as much as the TTX‐induced increase in Experiment 1. When these animals with functional hippocampi could not determine the rewarded period because the light was always off, lever pressing increased much more and was similar to the TTX‐induced increase in Experiment 1. We conclude that the TTX inactivation of the hippocampi impaired the ability to recognize the reward place. © 2005 Wiley‐Liss, Inc.
Hippocampal neurogenesis is not enhanced by lifelong reduction of glucocorticoid levels
Authors: Brunson Kristen L. , Baram Tallie Z. , Bender Roland A. 
Published: March 2005

AbstractNeurogenesis of dentate gyrus granule cells is generally considered to be negatively regulated by glucocorticoids. We tested the hypothesis that exposure to low plasma corticosteroid levels starting in the early postnatal period enhances granule cell proliferation rate during adulthood. Rat pups were adrenalectomized (ADX) on postnatal day 10 and were then “clamped” throughout life at low corticosterone levels via oral supplementation. Neurogenesis was determined using BrdU immunochemistry at 3 and 12 months in clamped rats as compared with age‐matched, sham‐operated controls. Rate of neurogenesis did not differ between the groups at either 3 or 12 months. It was significantly lower in 12‐month‐old compared with 3‐month‐old rats, despite the presence of an age‐dependent increase of plasma corticosterone only in the sham‐ADX rats. Granule cell layer volume, granule cell density, and granule cell degeneration (determined using apoptotic markers) were indistinguishable in the two groups, further supporting the comparable rate of neurogenesis under differing chronic glucocorticoid levels. In addition, whereas acute deprivation of plasma glucocorticoids (adrenalectomy) in adult rats evoked a burst of granule cell neurogenesis, complete elimination of these hormones (by stopping hormone supplementation) in adult, early‐life ADX/clamped rats did not. These data do not support a simple inverse relationship between chronic plasma glucocorticoid levels and granule cell neurogenesis. Specifically, chronic modulation of glucocorticoid levels commencing early in life evokes additional, adaptive, and compensatory mechanisms that contribute to the regulation of granule cell proliferation. © 2005 Wiley‐Liss, Inc.
Mouse models of impaired fear memory exhibit deficits in amygdalar LTP
Authors: Schimanski Lesley A. , Nguyen Peter V. 
Published: March 2005

AbstractInbred mouse strains have different genetic backgrounds that can result in impairments of synaptic plasticity and memory. They are valuable models for probing the mechanisms of memory impairments. We examined fear memory in several inbred strains, along with synaptic plasticity that may underlie fear memory. Long‐term potentiation (LTP) is a form of activity‐dependent synaptic plasticity that is a candidate cellular mechanism for some forms of learning and memory. Strains with impaired contextual or cued fear memory may have selective LTP deficits in different hippocampal subregions, or in the amygdala. We measured fear memory and its extinction in five inbred strains: C57BL/6NCrlBR (B6), A/J, BALB/cByJ (BALB), C57BL/10J (B10), and SM/J (SM). We also measured LTP in the basolateral amygdala and in the hippocampal Schaeffer collateral–commissural (SC) and medial perforant pathways (MPP). All strains exhibited intact contextual fear memory 24 h post‐training, but cued fear memory was impaired in strains A/J, BALB, and SM. At 1 h post‐training, both contextual and cued fear memory deficits were more widespread: all strains except for B6 and B10 showed impairments of both types of memory. Contextual fear extinction was impaired in BALB and SM. We found that amygdalar LTP was reduced in strains A/J and BALB, but SC LTP was intact in all strains (except for a selective multi‐train LTP impairment in BALB). MPPLTP was similar in all five strains. Thus, reduced amygdalar LTP is correlated with impaired cued fear memory in strains A/J and BALB. Also, hippocampal SC LTP is more strongly correlated with 24‐h (long‐term) than with 1‐h (short‐term) contextual fear memory. In this first conjoint study of amygdala‐dependent memory and amygdalar LTP in inbred mice, we identified specific hippocampal and amygdalar LTP deficits that correlate with fear memory impairments. These deficits should be considered when selecting inbred strains for genetic modification. © 2005 Wiley‐Liss, Inc.
Regulation of manganese accumulation in perinatally exposed rat pups
Authors: Kostial Krista , Blanuša Maja , Piasek Martina 
Published: March 2005

AbstractThe risk of manganese (Mn)‐related ill effects in the neonate has been the topic of several investigations because in formula‐fed infants Mn intake is much higher than in breast‐fed infants. In the young, when Mn homeostasis is not yet developed, increased Mn intake might pose a neurotoxic risk. Our work aimed at collecting new data on Mn accumulation during the perinatal period by using an experimental rat model in pups whose mothers were exposed orally to Mn in drink (as manganese chloride; dose of 2000 ppm Mn) throughout pregnancy and 11 days of lactation. Pups were cross‐fostered at birth and placental and mammary transfer of Mn at birth and at the age of 11 days was evaluated. The total pup body burden of Mn was analysed by atomic absorption spectrometry. Concentrations of iron (Fe), zinc (Zn) and calcium (Ca) also were analysed at the end of the experiment.The concentration of Mn in perinatally exposed pups was 6–8 times higher than in controls, irrespective of the period and duration of exposure. After cessation of exposure, the Mn concentration decreased almost to control levels. Concentrations of other essential elements (Fe, Zn, Ca) were not affected by Mn exposure. Our results indicate the existence of an accurate regulation of Mn accumulation in pups exposed to Mn during the perinatal period. Copyright © 2005 John Wiley & Sons, Ltd.
Etoposide‐induced cytogenotoxicity in mouse spermatogonia and its potential transmission
Authors: Palo Anil K. , Sahu Prajyoti , Choudhury Ramesh C. 
Published: March 2005

AbstractAs cancer chemotherapeutic agents are cytogenotoxic but not target‐specific during systemic treatment, they affect all the encountered cells including the non‐cancerous ones and consequently lead to the recurrence of second malignancy in post‐chemotherapeutic cancer survivors. The effects would be persistent if the stem cells were affected. These drugs also may affect germline cells during therapeutic treatments. There is every chance that the effects are transmitted through the germline cells to the gametes and to the next generation if the gonadal mother cells are affected. Such transmission of effects from the post‐chemotherapeutic childhood cancer survivors is of serious concern but very little attention has been given so far to such studies.Etoposide (VP‐16) — a semi‐synthetic epipodophyllotoxin derivative, a DNA non‐intercalating agent and a topoisomerase II inhibitor — is prescribed frequently for the treatment of various types of cancers. It is a potent clastogen inducing chromosomal damage both in vitro and in vivo. Its clastogenic effect is indirect through inhibition of the catalytic activity of topoisomerase II enzymes, which maintain the topology of DNA during replication, recombination, transcription, etc. by forming a ‘cleavable complex’ and facilitate the cleaving and re‐ligation of the cleaved DNA to relieve the torsional stress during such events. Transient stabilization of the cleavable complex by etoposide leads to illegitimate ligation of the cleaved DNA. Consequently, single‐ and double‐strand breaks occur.In the present study, the clastogenic potential of three different doses of etoposide (10, 15 and 20 mg kg−1) in the male germline of mice was assessed from the dividing spermatogonia after a single exposure for one cell cycle duration at 24 h post‐treatment. Transmission of such effects was assessed from the frequency of aberrant primary spermatocytes at week 4 post‐treatment and of abnormal sperm at week 8 post‐treatment.All three doses of etoposide were found to be clastogenic to the dividing spermatogonia of mice, and mostly chromatid breaks were induced. The effects also were transmitted through the male germline of mice, which was evident from the prevalence of statistically significant increased percentages of aberrant primary spermatocytes at week 4 posttreatment and the higher percentages of abnormal sperm at week 8 post‐treatment. Thus, there is every chance that the cytogenotoxic effects of etoposide are transmitted to the next generation through the male germline of post‐chemotherapeutic cancer survivors, therefore it is essential to make etoposide target‐specific or modulate its effects. Copyright © 2005 John Wiley & Sons, Ltd.