bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Bedeutung der Interleukine und des Candida‐IgE bei der chronisch rezidivierenden Vulvovaginalcandidose
Authors: Weissenbacher E. R. , Weissenbacher T. , Spitzbart H.
Published: November 2004

Wir untersuchten 104 Patientinnen mit einer chronisch rezidivierenden Vulvovaginalcandidose. Als Kontrollgruppe dienten 41 völlig gesunde Frauen. Es wurde zunächst die kulturelle Anzüchtung mit Differenzierung von Candida durchgeführt. In 29,8% fanden wir Candida spp. im Scheideninhalt. Zwei Frauen der Kontrollgruppe waren kolonisiert. Weiterhin bestimmten wir die Interleukine IL 4, 5 und 13, wobei lediglich bei IL 4 ein signifikanter Anstieg der Werte zu verzeichnen war. Außerdem wurden Prostaglandin E2, das Gesamt‐IgE und das Candida‐spezifische IgE bestimmt. Auch hier waren Prostaglandin E2 und das Candida‐IgE im Vergleich zur Kontrollgruppe signifikant erhöht, während das Gesamt‐IgE keine signifikante Erhöhung zeigte. Daraus ergibt sich eine allergische Komponente bei der chronisch rezidivierenden Vulvovaginalcandidose, die dazu Anlass gibt, über die Therapie erneut nachzudenken.
Performance des Candida‐Mannan‐Antigennachweises bei Patienten mit Fungämien
Authors: Rimek D. , Redetzke K. , Singh J. , Heinrich K. , Kappe R.
Published: November 2004

Zur Diagnostik invasiver Candidosen steht seit einigen Jahren der kommerziell erhältliche Platelia®Candida Mannan Antigen Enzymimmunoassay (Candida EIA) zur Verfügung. Wir evaluierten den Candida EIA an Patienten mit nachgewiesener Fungämie durch Sproßpilze, von denen zumindest eine Serumprobe zur Verfügung stand. In die Studie eingeschlossen wurden 59 Patienten mit 121 Serumproben, von denen 61 verschiedene Sproßpilz‐Isolate aus Blutkulturen angezüchtet wurden. Der Candida EIA war bei 43 von 59 Fungämie‐Patienten positiv (n = 35) oder grenzwertig (n = 8), woraus eine Sensitivität von 73% resultierte. Für die einzelnen Sproßpilz‐Arten ergaben sich folgende Positiv‐Raten: Candida albicans 30 von 39 (77%), Candida glabrata 7 von 11 (64%), Candida parapsilosis 1 von 3, Candida tropicalis 2 von 2, Candida kefyr 2 von 2, Candida lipolytica 0 von 1, Candida lusitaniae 1 von 1, Candida krusei 1 grenzwertig von 1, Saccharomyces cerevisiae 1 von 1. Bei 6 Patienten war der zeitliche Antigen‐Verlauf auswertbar. In 3 Fällen war der Antigennachweis 3 bis 4 Tage vor dem Tag der Blutkulturentnahme positiv, in einem Fall am selben Tag und in 2 Fällen 2 bzw. 5 Tage danach.

Schlußfolgerungen

Der Candida EIA war zur Erfassung von Fungämien durch die häufigsten fakultativ pathogenen Sproßpilz‐Arten geeignet. Der Test war bei etwa der Hälfte der Patienten vor einer Blutkultur positiv und trug damit zur frühzeitigen Diagnosestellung einer invasiven Candidose bei.
Erfahrungen zum Antigennachweis bei invasiver Aspergillose und Candidose in Österreich
Authors: Willinger B.
Published: November 2004

Für die Beurteilung von verschiedenen Methoden zum Antigennachweis invasiver Mykosen wurden Daten aus fünf österreichischen Krankenhäusern herangezogen. Im Rahmen der Diagnose von invasiven Aspergillosen wurde der Enzymimmunoassay (EIA) Platelia®Aspergillus Antigen (Bio‐Rad, USA) verwendet und mit klinischen Angaben verglichen. Dabei zeigte sich, dass die Aussagekraft der Ergebnisse von Einzelseren beschränkt ist. Wesentlich günstiger ist es, seriell abgenommene Seren im Sinne eines Screeningverfahrens zu untersuchen. In Einzelfällen konnte auch mit der Untersuchung anderer Körperflüssigkeiten die Diagnose untermauert oder bestätigt werden. Beim Nachweis von invasiven Candidosen stehen mehrere Verfahren zum Antigennachweis zur Verfügung. Ergebnisse, die mit dem EIA Platelia®Candida Antigen (Bio‐Rad, USA), dem Latexagglutinationstest Cand‐Tec® (Ramco, USA) und dem Nachweis von (1‐3)‐Beta‐D‐Glucan mittels Glucatell® (CAPE COD, USA) erzielt wurden, konnten miteinander verglichen werden. Bei den uns zur Verfügung stehenden Daten zeigte der Nachweis von (1‐3)‐Beta‐D‐Glucan mittels Glucatell die besten Ergebnisse. Alle klinisch diagnostizierten Fälle tiefer oder systemischer Candida‐Infektionen zeigten eindeutig positive Ergebnisse. Bei dem Platelia Candida Antigennachweis und dem Cand‐Tec zeigten sich zum Teil widersprüchliche Ergebnisse, die eine weitere Evaluierung der Tests erfordern. Die Anzahl der getesteten Seren ist sicher zu klein, um diese Testkits abschließend zu beurteilen. Weitere Untersuchungen mit prospektiv erhobenen Daten sind unbedingt erforderlich, um den richtigen Einsatz der verschiedenen Methoden zum Antigennachweis klarzulegen und die adäquate Vorgangsweise empfehlen zu können.
Zur Bewertung der Zellwandantigen‐basierten Candida‐Serologie
Authors: Müller J. , Melchinger W.
Published: November 2004

Der Artikel gibt eine Übersicht über den derzeitigen Kenntnisstand der Zellwandantigen‐basierten Candida‐Serologie. Über Zellwandantigen‐basierte Candida‐Antikörpernachweisverfahren liegen Erfahrungen aus mehr als vier Jahrzehnten vor. Die Mannan‐Antigene der Candida‐Arten sind serologisch und biochemisch gut charakterisiert. Die Candida‐Mannan‐Antigene sind potente Immunogene, auf die das Immunsystem des menschlichen Wirts regelhaft reagiert. Der menschliche Wirt ist gegenüber Candida albicans‐Antigenen immunologisch nicht naiv. Bei Bewertungsverfahren der Candida‐Antikörpernachweise aus klinischer und labordiagnostischer Sicht müssen zwingend die pathogenetischen Besonderheiten der Candidämie und der Candidose als opportunistischer Infektionen berücksichtigt werden.
Do we have Room for Shining Eyes and Cows as Comrades ? Gender Perspectives on Organic Farming in Denmark
Authors: Pedersen Kirsten Bransholm , Kjærgård Bente
Published: November 2004

Starting from a theoretical discussion on the relations between women and nature, the overall aim of the paper is to discuss how the ongoing structural changes in organic agriculture affect the everyday life, roles and positions of professional women in the sector and relate to the construction of gender and identity in organic farming. When organic farming was implemented in Denmark, both women and men were active participants in defining its principles and practises. Hence organic farming has the potential for creating alternative relations and for reviving female values and interests in agriculture. To day however, organic farming has become more commercialised leading to the gradual penetration and dominance of the values and practises of conventional farming. So how sustainable will future organic farming be with respect to gender relations? The paper focuses on the recent development of organic farming and explores some of the dilemmas and prospects related to different discourses of organic farming. The dominating institutionalised discourse primarily aims at reducing or eliminating environmental problems or dilemmas characteristic of conventional farming. This is notably distinct from a more holistic discourse emphasising broader and more emancipatory organic principles and practises. Our view is that most professional women in the organic sector relate to the latter category and hence are in danger of becoming a ‘threatened species’ within the sector. Empirically we have challenged this view by interviewing women on their values, interests and practises within organic farming.
Adjunctive Bright Light in Non‐Seasonal Major Depression
Authors: Martiny K.
Published: November 2004

Objective:Bright light treatment is an established treatment for Seasonal Affective Disorder, but in non‐seasonal depression research results have been contrasting.

Method:This study was designed as a 5‐week controlled, double‐blind, parallel trial in out‐patients with a diagnosis (DSM‐IV) of non‐seasonal major depression, randomized to either active treatment (white light, 10 000 lux, 1 h daily) or placebo treatment (red light, 50 lux, 30 min daily) and concomitant treatment with sertraline in both groups.

Results:One hundred and two patients were included in the study. Analyses showed that on all used scales the reduction in depression scores was larger in the bright light group than in the dim light group, and this reached statistical significance on all observer rating scales and on the SCL‐90R self‐assessment scale. The HAM‐D6was the most sensitive scale to measure improvement at endpoint.

Conclusion:The study results support the use of bright light as an adjunct treatment to antidepressants in non‐seasonal depression.
Influence of oral antioxidants on ultraviolet radiation‐induced skin damage in humans
Authors: Swindells K. , Rhodes L. E.
Published: November 2004

Ultraviolet radiation (UVR) causes a range of acute and chronic adverse cutaneous effects, in addition to some beneficial effects. In present times, the skin is generally exposed to higher levels of UVR, such that inherent defence mechanisms become overwhelmed. Complications, notably skin malignancies, show a serious rise in incidence. Since many effects of UVR are mediated through generation of reactive oxygen species, antioxidant supplementation provides a strategy to combat their excess generation, and hence reduce the clinical consequences. Human supplementation studies examining the potential of a range of oral agents to protect against UVR‐induced skin effects show mixed results; further studies should examine whether certain subgroups of the population may show augmented benefit.
Iatrogenic skin cancer: induction by psoralen/ultraviolet A and immunosuppression of organ transplant recipients
Authors: McKenna K. E.
Published: November 2004

Photochemotherapy (psoralen/UVA (PUVA)) is an efficient therapeutic tool for a wide range of skin diseases. Concern, however, exists regarding the long‐term carcinogenic effects of this treatment modality and, as a consequence, is being used less frequently. PUVA remains an important treatment in our therapeutic armamentarium but must be used with caution in those patients with risk factors and cumulative dose exposure must be limited. PUVA‐induced cancers show features in common with skin cancers induced by immunosuppressed organ transplant recipients. Tumours in the latter group of individuals are, however, much more aggressive and difficult to manage.
Oro‐facial lesions and CD4 counts associated with HIV/AIDS in an adult population in Oyo State, Nigeria
Authors: Adurogbangba MI , Aderinokun GA , Odaibo GN , Olaleye OD , Lawoyin TO
Published: November 2004

Objective:  The objective of this study was to define the oro‐facial lesions associated with Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) in an adult population in Oyo state, Nigeria and to relate these with the level of immune suppression as measured by the CD4 counts.

Materials and method:  The study population consisted of 679 consecutive subjects who were seen at the state‐owned blood bank. Information on demography, medical and medication histories were obtained. Oro‐facial examinations were carried out according to Greenspan et al [Oral Surg Oral Med Oral Pathol (1992)73:142–144]. HIV sero‐prevalence status was determined for all patients. CD4+ T‐lymphocyte count was carried out for those sero‐positive for HIV and 31 randomly selected HIV‐negative subjects. Data were analyzed using the chi‐square test, Fisher's exact test, Student's t‐test and odds ratio where appropriate.

Results:  Eighty‐one (11.9%) of the entire study sample were confirmed HIV positive. The prevalence of specific oral lesions by HIV sero‐status revealed that pseudomembranous oral candidiasis and angular cheilitis occurred significantly and more frequently in HIV‐positive subjects (33.3 and 21% respectively) than those who were HIV negative (4.3 and 1.8% respectively, P < 0.05). The mean CD4 count of the HIV‐positive subjects was 452 cells mm−3, s.d. 137, while it was 602 cells mm−3, s.d. 251, for the HIV negatives. The difference was statistically significant (P = 0.000). Forty‐four (66.7%) subjects with CD4 counts <500 cells mm−3 had oro‐facial lesions whereas among those with CD4 counts >500 cells mm−3 only 22 (33.3%) had oro‐facial lesions (OR = 4.57).

Conclusion:  The type of oro‐facial lesions most commonly associated with HIV/AIDS in Oyo state, Nigeria, has been shown to be pseudomembranous oral candidiasis. This was followed by angular cheilitis. These lesions, although found in HIV‐negative subjects, were in a lower proportion as compared with HIV‐positive subjects. Mean CD4 counts were lower in HIV‐positive subjects and this was associated with greater prevalence of oro‐facial candidiasis and angular cheilitis.
Liposarcoma circumscriptum (lipoma‐like) of the tongue: report of a case
Authors: Capodiferro S , Scully C , Maiorano E , Lo Muzio L , Favia G
Published: November 2004

Liposarcoma, first described by Virchow in 1857, is the second most frequent sarcoma of soft tissues, although it is rare both in the head and neck and the oral cavity. Intra‐orally, liposarcoma has been reported in the jawbones (particularly the maxilla) and the soft tissues – mainly the cheek and floor of mouth, but it is rare in the tongue. A case of well‐differentiated, superficial liposarcoma circumscriptum of the tongue is reported. The authors underline the difficulties in the clinical and histopathological diagnosis, as this tumour may be confused with lipoma. In view of the indolent behaviour of this tumour type, local recurrence or metastasis rarely occur; consequently, conservative surgical therapy is advised without adjuvant chemo‐radio therapy.
Regulation of interleukin‐6 expression by arecoline in human buccal mucosal fibroblasts is related to intracellular glutathione levels
Authors: Tsai C‐H , Yang S‐F , Chen Y‐J , Chu S‐C , Hsieh Y‐S , Chang Y‐C
Published: November 2004

Objectives:  Cytokines play an important role in regulating fibroblast function and is likely to play a key role in regulating the initiation and progression of scarring in any fibrotic disease. Interleukin‐6 (IL‐6) has been implicated in the development of a variety of fibrotic diseases. The aim of this study was to compare IL‐6 expression in fibroblasts cultured from normal human buccal mucosa and oral submucous fibrosis (OSF) specimens and further explore the potential mechanism that may lead to induce IL‐6 expression.

Methods:  mRNA level of IL‐6 in fibroblasts from OSF was compared with normal buccal mucosa. The effects of arecoline, the major areca nut alkaloid, on IL‐6 expression in normal human buccal mucosa fibroblasts (BMFs) were measured in vitro. mRNA was quantified with AlphaImager 2000. To determine whether glutathione (GSH) levels were important in the induction of IL‐6 by arecoline, we pretreated cells with 2‐oxothiazolidine‐4‐carboxylic acid (OTZ) to boost GSH levels or with buthionine sulfoximine (BSO) to deplete GSH.

Results:  Fibroblasts derived from OSF exhibited higher IL‐6 gene expression than BMF in mRNA levels (P < 0.05). The exposure of quiescent BMF to arecoline resulted in the elevation of IL‐6 mRNA expression in a dose‐dependent manner (P < 0.05). IL‐6 gene regulated by arecoline correlated with intracellular GSH levels in BMF. Arecoline at a concentration of 129 μM induced about 2.7‐fold IL‐6 mRNA levels over the 6‐h incubation period. However, BSO enhanced the IL‐6 mRNA levels by 3.9‐fold (P < 0.05). In addition, OTZ was found to marginally reduce the arecoline‐induced IL‐6 expression by about 1.7‐fold (P < 0.05).

Conclusions:  Taken together, these results suggest that IL‐6 expression is significantly upregulated in OSF fibroblasts in areca quid chewers and arecoline may be responsible for the enhanced IL‐6 expression. In addition, the regulation of IL‐6 expression induced by arecoline is critically dependent on the intracellular GSH concentrations.
Poland–Moebius syndrome: a case with oral anomalies
Authors: Domingos AC , Lopes SLCP , Almeida SM , Boscolo FN , Whaites EJ
Published: November 2004

The combination of Moebius and Poland anomalies is rarely described in the literature. While some authors believe this association is an independent syndrome, others think that Poland, Moebius and Poland–Moebius syndromes are variations of the same condition. We report a case of Poland–Moebius syndrome in a 6‐year‐old girl who presented with bilateral convergent strabismus, the inability to abduct her eyes beyond the midline and brachydactyly of her right hand. Oral manifestations included incompetent lips and an abnormal tongue. Other facial features included hypoplasia of her mandible and her left ear at a slightly lower level than her right ear. Panoramic and lateral skull radiographs confirmed the absence of certain teeth and the hypoplastic mandible. The diagnosis of Poland–Moebius syndrome was made on the basis of cranial nerve involvement and oro‐facial manifestations.
Activities of daily living and chewing ability in an 80‐year‐old population
Authors: Takata Y , Ansai T , Awano S , Sonoki K , Fukuhara M , Wakisaka M , Takehara T
Published: November 2004

Objectives:  The aim of this study was to determine whether chewing ability or number of intact teeth was related to performance of activities of daily living in 80‐year olds.

Design:  This was a cross‐sectional survey including dental examinations, chewing self‐assessment, and everyday function.

Subjects and Methods:  A total of 823 people (309 males, 514 females) who were 80 years of age and resident in the Fukuoka Prefecture, Japan participated in this study.

Results:  The mean number of intact teeth was 7.5 ± 8.7; of the 15 food items offered, the mean number of foods chewed was 11.2 ± 3.8. Function was independent in 713 subjects, and dependent in 93. After adjustment for gender, we found the number of foods chewed being linked to independent function by the multiple regression analysis (β = 0.223, P < 0.0001); the number of intact teeth was only weakly related (β = 0.077, P = 0.03). By logistic regression analysis, functional dependency was 7.5 times more prevalent in individuals capable of chewing four foods or fewer, and 3.3 times more prevalent in those chewing five to nine, than in those chewing all 15 items. No significant functional difference was related to the number of intact teeth.

Conclusion:  Chewing ability may be independently related with functional status in 80‐year olds.
Oral findings in coeliac disease and Sjögren's syndrome
Authors: Patinen P , Aine L , Collin P , Hietanen J , Korpela M , Enckell G , Kautiainen H , Konttinen YT , Reunala T
Published: November 2004

Objective:  Both coeliac disease (CD) and Sjögren's syndrome (SS) have an autoimmune background and increased risk of oral mucosal and dental abnormalities. Individuals suffering concomitantly from CD and SS could even be at a higher risk.

Study design:  Oral mucosal and dental abnormalities were examined in 20 patients with CD + SS (mean age 61 years) and compared with age‐ and sex‐matched controls with either CD or SS.

Results:  Oral mucosal changes were most common in SS (80%), followed by CD + SS (65%) and CD (40%). Coeliac‐type dental enamel defects were found in 89% in CD + SS and in 88% in CD compared with only 25% in SS (P < 0.001). The median number of teeth was six in the CD + SS, 24 in the CD and 22 in the SS group. The DMF index was higher (P < 0.005) in the CD + SS than in the CD group. CD + SS was characterized by higher salivary flow rate (P < 0.001) and lower inflammatory focus score in the salivary glands (P < 0.01) than SS.

Conclusions:  The co‐occurrence of CD and SS should be recognized because of its effects on dental and oral mucosal health. A lower salivary gland inflammatory focus score and higher salivary flow rate in CD + SS than in SS suggests that a gluten‐free diet treatment may alleviate autoimmune inflammation.
The association of tobacco and other factors with recurrent aphthous stomatitis in an US adult population
Authors: Rivera‐Hidalgo F , Shulman JD , Beach MM
Published: November 2004

Objective:  To determine point and annual prevalence of recurrent aphthous stomatitis (RAS).

Setting:  Reported prevalence of RAS in textbooks and much of the literature varies according to study location, patient selection and whether point prevalence (presence of lesions at examination) or period prevalence (history of lesions during a specified period) is reported. Many studies are based on non‐probability samples and this may contribute to significant variation in reported prevalence and factors presumed to be associated with RAS.

Methods:  We analyzed data from the Third National Health and Nutrition Examination Survey, 1988–1994, a large United States probability sample, for RAS and covariates suggested in the literature using bivariate and multivariate logistic regression.

Results:  Oral mucosal examinations were performed on 17 235 adults 17 years and older. Of these, 146 (0.89%) had at least one clinically apparent aphthous lesion. For annual (reported) prevalence, Whites (20.87%) and Mexican‐Americans (12.88%) had several fold higher prevalence of RAS than Blacks (4.96%). Adults younger than 40 years of age had almost twice the prevalence (22.54%) of those older than 40 years (13.42%).

Conclusion:  Annual prevalence was significantly higher in whites and Mexican‐Americans (compared with blacks), individuals 17–39 years of age, cigarette non‐smokers, and those with recurrent herpes labialis history; while it was lower in males. Point prevalence was significantly higher in whites, Mexican‐American, individuals 17–39 years of age, cigarette non‐smokers, and males.
Effects of stretch‐activated channel blockers on [Ca2+]i and muscle damage in the mdx mouse
Authors: Yeung Ella W. , Whitehead Nicholas P. , Suchyna Thomas M. , Gottlieb Philip A. , Sachs Frederick , Allen David G.
Published: November 2004

The mdx mouse lacks dystrophin and is a model of human Duchenne muscular dystrophy. Single mdx muscle fibres were isolated and subjected to a series of stretched (eccentric) contractions while measuring intracellular calcium concentration ([Ca2+]i) with fluo‐3 and confocal microscopy. Following the stretched contractions there was a slow rise in resting [Ca2+]i and after 30 min both the [Ca2+]i during a tetanus (tetanic [Ca2+]i) and the tetanic force were reduced. Two blockers of stretch‐activated channels, streptomycin and the spider venom toxin GsMTx4, prevented the rise of resting [Ca2+]i and partially prevented the decline of tetanic [Ca2+]i and force. Reducing extracellular calcium to zero also prevented the rise in resting [Ca2+]i and prevented some of the decline in tetanic [Ca2+]i and force. Patch‐clamping experiments identified a stretch‐activated channel in both wild‐type and mdx myotubes which was blocked by GsMTx4. These data suggest that blockers of stretch‐activated channels can ameliorate the force reduction following stretched contractions by reducing the influx of Ca2+ into the muscle. We therefore tested whether in intact mdx mice streptomycin, added to the drinking water, was capable of reducing muscle damage. mdx mice show a period of muscle damage from 20 to 40 days of life and fibres which regenerate from this damage display central nuclei. We measured the frequency of central nuclei in control mdx mice compared to streptomycin‐treated mdx mice and showed that the incidence of central nuclei was significantly reduced by streptomycin treatment. This result suggests that blockers of stretch‐activated channels may protect against muscle damage in the intact mdx mouse.
Layer‐specific pyramidal cell oscillations evoked by tetanic stimulation in the rat hippocampal area CA1 in vitro and in vivo
Authors: Vreugdenhil Martin , Bracci Enrico , Jefferys John G. R.
Published: November 2004

Tetanic stimulation of axons terminating in the CA1 region of the hippocampus induces oscillations in the gamma‐to‐beta frequency band (13–100 Hz) and can induce long‐term potentiation (LTP). The rapid pyramidal cell discharge is driven by a mainly GABAA‐receptor‐mediated slow depolarization and entrained mainly through ephaptic interactions. This study tests whether cellular compartmentalization can explain how cells, despite severely reduced input resistance, can still fire briskly and have IPSPs superimposed on the slow GABAergic depolarization, and whether this behaviour occurs in vivo. Oscillations induced in CA1 in vitro by tetanic stimulation of the stratum radiatum or oriens were analysed using intracellular and multichannel field potentials along the cell axis. Layer‐specific effects of focal application of bicuculline indicate that the GABAergic depolarization is concentrated on tetanized dendrites. Current‐source density analysis and characteristics of partial spikes indicate that early action potentials are initiated in the proximal nontetanized dendrite but cannot invade the tetanized dendrite, where recurrent EPSPs and evoked IPSPs were largely suppressed. As the oscillation progresses, IPSPs recover and slow the neuronal firing to β frequencies, with a small subpopulation of neurons continuing to fire at γ frequency. Carbonic anhydrase dependence, threshold intensity, frequency, field strength and spike initiation/propagation of tetanus‐evoked oscillations in urethane‐anaesthetized rats, validate our observations in vitro, and show that these mechanisms operate in healthy tissue. However, the disrupted electrophysiology of the tetanized dendrites will disable normal information processing, has implications for LTP induction and is likely to play a role in pathological synchronization as found during epileptic discharges.
Frequency‐dependent acceleration of relaxation in mammalian heart: a property not relying on phospholamban and SERCA2a phosphorylation
Authors: Valverde Carlos A. , Mundiña‐Weilenmann Cecilia , Said Matilde , Ferrero Paola , Vittone Leticia , Salas Margarita , Palomeque Julieta , Petroff Martín Vila , Mattiazzi Alicia
Published: November 2004

An increase in stimulation frequency causes an acceleration of myocardial relaxation (FDAR). Several mechanisms have been postulated to explain this effect, among which is the Ca2+–calmodulin‐dependent protein kinase (CaMKII)‐dependent phosphorylation of the Thr17 site of phospholamban (PLN). To gain further insights into the mechanisms of FDAR, we studied the FDAR and the phosphorylation of PLN residues in perfused rat hearts, cat papillary muscles and isolated cat myocytes. This allowed us to sweep over a wide range of frequencies, in species with either positive or negative force–frequency relationships, as well as to explore the FDAR under isometric (or isovolumic) and isotonic conditions. Results were compared with those produced by isoprenaline, an intervention known to accelerate relaxation (IDAR) via PLN phosphorylation. While IDAR occurs tightly associated with a significant increase in the phosphorylation of Ser16 and Thr17 of PLN, FDAR occurs without significant changes in the phosphorylation of PLN residues in the intact heart and cat papillary muscles. Moreover, in intact hearts, FDAR was not associated with any significant change in the CaMKII‐dependent phosphorylation of sarcoplasmic/endoplasmic Ca2+ ATPase (SERCA2a), and was not affected by the presence of the CaMKII inhibitor, KN‐93. In isolated myocytes, FDAR occurred associated with an increase in Thr17 phosphorylation. However, for a similar relaxant effect produced by isoprenaline, the phosphorylation of PLN (Ser16 and Thr17) was significantly higher in the presence of the β‐agonist. Moreover, the time course of Thr17 phosphorylation was significantly delayed with respect to the onset of FDAR. In contrast, the time course of Ser16 phosphorylation, the first residue that becomes phosphorylated with isoprenaline, was temporally associated with IDAR. Furthermore, KN‐93 significantly decreased the phosphorylation of Thr17 that was evoked by increasing the stimulation frequency, but failed to affect FDAR. Taken together, the results provide direct evidence indicating that CaMKII phosphorylation pathways are not involved in FDAR and that FDAR and IDAR do not share a common underlying mechanism. More likely, a CaMKII‐independent mechanism could be involved, whereby increasing stimulation frequency would disrupt the SERCA2a–PLN interaction, leading to an increase in SR Ca2+ uptake and myocardial relaxation.
Oscillatory activity within rat substantia gelatinosa in vitro: a role for chemical and electrical neurotransmission
Authors: Asghar Aziz U. R. , Cilia La Corte Paul F. , LeBeau Fiona E. N. , Dawoud Mutaz Al , Reilly Siobhan C. , Buhl Eberhard H. , Whittington Miles A. , King Anne E.
Published: November 2004

Although rhythmic behaviour of mammalian spinal ventral horn networks has been extensively studied little is known about oscillogenesis in the spinal dorsal horn. The aims of this in vitro study were to record and determine the underlying mechanisms of potassium‐evoked network field oscillations in the substantia gelatinosa of the neonatal rat dorsal horn, a lamina involved in nociceptive processing. Transient pressure ejection of a potassium solution evoked reproducible rhythmic activity in discrete areas of the substantia gelatinosa which lasted for 5–15 s with a single prominent peak in the 4–12 Hz frequency band (7.7 ± 0.1 Hz,
n= 60). Oscillations of similar frequency and amplitude were also observed in isolated dorsal horn quadrants. Application of CNQX (10 μm) reduced peak power amplitude and integrated power area (from 4 to 12 Hz) of the power spectrum, whereas d‐AP5 (50 μm) had no effect on the potassium‐evoked rhythm. Bicuculline (30 μm) or strychnine (10 μm) reduced the power amplitude and area. On combination of bicuculline (30 μm) and strychnine (10 μm) the reductions in power amplitude and area were not significantly different
(P > 0.05) when compared with application of either drug alone. The gap junction blockers carbenoxolone (100 μm) or octanol (1 mm) significantly reduced power amplitude and area. Although TTX (1 μm) or a calcium‐free perfusate both caused reductions in the power amplitude and area, potassium‐evoked rhythmic activity persisted. However, this persistent rhythm was further reduced on combination of calcium‐free perfusate with octanol (1 mm) and was abolished using a cocktail of drugs. Blockade of the potassium delayed rectifier current by tetraethylammonium (5 mm) or the hyperpolarization‐activated current (Ih) by ZD7288 (10 μm) disrupted the synchronization of the potassium‐induced oscillation. The frequency of potassium‐induced rhythms was unaffected by any of the drugs tested. These novel findings demonstrate that transient pressure ejection of potassium evokes oscillatory activity in the substantia gelatinosa in vitro. This rhythm is partly dependent upon various receptors (AMPA/kainate, GABAA and glycine), ion channels (potassium delayed rectifier and Ih) and gap junctions. Oscillatory behaviour in the substantia gelatinosa could potentially play a role in the processing of nociceptive signals.
Aspects of the homeostaic plasticity of GABAA receptor‐mediated inhibition
Authors: Mody Istvan
Published: November 2004

Plasticity of ligand‐gated ion channels plays a critical role in nervous system development, circuit formation and refinement, and pathological processes. Recent advances have mainly focused on the plasticity of channels gated by excitatory amino acids, including their acclaimed role in learning and memory. These receptors, together with voltage‐gated ion channels, have also been known to be subjected to a homeostatic form of plasticity that prevents destabilization of the neurone's function and that of the network during various physiological processes. To date, the plasticity of GABAA receptors has been examined mainly from a developmental and a pathological point of view. Little is known about homeostatic mechanisms governing their plasticity. This review summarizes some of the findings on the homeostatic plasticity of tonic and phasic inhibitory activity.
Two developmental switches in GABAergic signalling: the K+–Cl− cotransporter KCC2 and carbonic anhydrase CAVII
Authors: Rivera Claudio , Voipio Juha , Kaila Kai
Published: November 2004

GABAergic signalling has the unique property of ‘ionic plasticity’, which is based on short‐term and long‐term changes in the Cl− and HCO3− ion concentrations in the postsynaptic neurones. While short‐term ionic plasticity is caused by activity‐dependent, channel‐mediated anion shifts, long‐term ionic plasticity depends on changes in the expression patterns and kinetic regulation of molecules involved in anion homeostasis. During development the efficacy and also the qualitative nature (depolarization/excitation versus hyperpolarization/inhibition) of GABAergic transmission is influenced by the neuronal expression of two key molecules: the chloride‐extruding K+–Cl− cotransporter KCC2, and the cytosolic carbonic anhydrase (CA) isoform CAVII. In rat hippocampal pyramidal neurones, a steep up‐regulation of KCC2 accounts for the ‘developmental switch’, which converts depolarizing and excitatory GABA responses of immature neurones to classical hyperpolarizing inhibition by the end of the second postnatal week. The immature hippocampus generates large‐scale network activity, which is abolished in parallel by the up‐regulation of KCC2 and the consequent increase in the efficacy of neuronal Cl− extrusion. At around postnatal day 12 (P12), an abrupt, steep increase in intrapyramidal CAVII expression takes place, promoting excitatory responses evoked by intense GABAergic activity. This is largely caused by a GABAergic potassium transient resulting in spatially widespread neuronal depolarization and synchronous spike discharges. These facts point to CAVII as a putative target of CA inhibitors that are used as antiepileptic drugs. KCC2 expression in adult rat neurones is down‐regulated following epileptiform activity and/or neuronal damage by BDNF/TrkB signalling. The lifetime of membrane‐associated KCC2 is very short, in the range of tens of minutes, which makes KCC2 ideally suited for mediating GABAergic ionic plasticity. In addition, factors influencing the trafficking and kinetic modulation of KCC2 as well as activation/deactivation of CAVII are obvious candidates in the ionic modulation of GABAergic responses. The down‐regulation of KCC2 under pathophysiological conditions (epilepsy, damage) in mature neurones seems to reflect a ‘recapitulation’ of early developmental mechanisms, which may be a prerequisite for the re‐establishment of connectivity in damaged brain tissue.
Stimulation of β‐adrenoceptors inhibits store‐operated channel currents via a cAMP‐dependent protein kinase mechanism in rabbit portal vein myocytes
Authors: Liu M , Large WA , Albert AP
Published: November 2004

Previously we have described the properties of store‐operated channel currents (SOCs) in freshly dispersed rabbit portal vein smooth muscle cells. In addition to Ca2+ store depletion these SOCs could also be activated by α‐adrenoceptor stimulation and diacylglycerol (DAG) via a protein kinase C (PKC)‐dependent mechanism. In the present study we have investigated the effect of β‐adrenoceptor stimulation on SOCs in rabbit portal vein myocytes. With whole‐cell recording the selective β‐adrenoceptor agonist isoprenaline reduced the current evoked by cyclopiazonic acid (CPA, sarcoplasmic/endoplasmic reticulum ATPase inhibitor) by over 85%. With cell‐attached patch recording, bath application of isoprenaline produced a pronounced inhibition of SOC activity evoked by either CPA or the acetoxymethyl ester form of BAPTA (BAPTA‐AM). SOC activity evoked by CPA, the DAG analogue, 1‐oleoyl‐acetyl‐sn‐glycerol (OAG) or the phorbol ester, phorbol‐12,13‐dibutyrate (PDBu) was also markedly inhibited by the adenylate cyclase activator, forskolin, and the cell‐permeable non‐hydrolysable analogue of cyclic adenosine monophosphate (cAMP), 8‐Br‐cAMP. With inside‐out patches, bath application of PDBu evoked channel currents with similar properties to SOCs which were inhibited by over 90% by a catalytic subunit of protein kinase A (PKA) and by 8‐Br‐cAMP. Moreover bath application of PKA inhibitors, H‐89, KT5720 and an inhibitory peptide to quiescent cell‐attached or inside‐out patches, activated channel currents with similar properties to SOCs. These data suggest that in rabbit portal vein myocytes, stimulation of β‐adrenoceptors inhibits SOC activity via a cAMP‐dependent protein kinase signal transduction cascade. In addition it is concluded that constitutive PKA activity has a profound inhibitory effect on SOC activity in this vascular preparation.
A Study on Squeeze Films Between Porous Rubber Surface and Rigid Surface: Analysis Based on the Viscoelastic Continuum Model
Authors: Kaneko Satoru , Tanaka Takemi , Abe Satoru , Ishikawa Takuya
Published: November 2004

The squeeze-film effect between a porous rubber surface and a rigid surface has been investigated as a problem of viscoelastic hydrodynamic lubrication (VEHL). An axisymmetric continuum model is introduced to estimate the surface deformation of a cylindrical porous rubber block based on a three-element viscoelastic model. The coefficients in the viscoelastic constitutive equation are experimentally determined and then the deformation of the porous rubber block is calculated by the FEM technique. The approximate solutions for the fluid pressures in the squeeze film are obtained from the equation of motion, which includes both local and convective inertia terms, and the continuity equation, using the perturbation method. Experimental data on the squeeze-film pressures and forces are also obtained under the sinusoidal squeezing motion of a rigid plate facing a cylindrical porous rubber block. It is found that the difference between the VEHL solutions and the EHL (elastohydrodynamic lubrication) solutions becomes more marked for a higher frequency of squeeze oscillation due to the effect of viscoelasticity of the porous rubber. The VEHL solutions hence correspond better to the measured results and yield a smaller surface deformation of the porous rubber block than the EHL solutions as the frequency of squeeze oscillation increases. The results also show that the fluid inertia effect due to the flow in the squeeze film becomes noticeable for a higher frequency of the squeezing motion as the effect of viscoelasticity of the porous rubber.
Ge
O
2
-doped SiO2 sputtered thin films: Microstructure, stoichiometry, and optical properties
Authors: Quartarone E. , Mustarelli P. , Marabelli F. , Battagliarin M. , Turato S.
Published: November 2004

Radio frequency sputtering is a reliable and low-cost technique for the deposition of oxide thin films. Here we report on the nonreactive preparation of SiO2 and SiO2–GeO2 films, which can be of interest in optics and optoelectronics. The deposition rate of SiO2–GeO2 is roughly three times higher than that of SiO2. Secondary ion mass spectroscopy shows SiO nonstoichiometry in SiO2 films, and the formation of Ge or Ge-based defects in SiO2–GeO2 samples. The best fits of the ellipsometric spectra confirm the nonstoichiometry of SiO2 films, showing that SiO fraction (and the refractive index, n) tends to decrease by increasing the deposition time.
Boron surfactant enhanced growth of thin Si films on CaF2∕Si
Authors: Wang C. R. , Müller B. H. , Bugiel E. , Wietler T. , Bierkandt M. , Hofmann K. R. , Zaumseil P.
Published: November 2004

Boron surfactant enhanced solid-phase epitaxy (SPE) of thin Si films on CaF2∕Si(111) substrates has been studied. Two different growth processes were investigated. In the first process, 1ML of boron atoms was predeposited on the CaF2 surface at room temperature before Si evaporation followed by an anneal to 635°C. This resulted in Si cluster formation. The surface morphology of the Si layer did not show any improvement compared to SPE without surfactant. In the second process, boron atoms were deposited directly on top of the amorphous Si film. This resulted in continuous and smooth epitaxial Si layers on CaF2 with a sharp B-induced (3×3)R30° surface reconstruction after annealing.
Micro-Auger electron spectroscopy studies of chemical and electronic effects at GaN-sapphire interfaces
Authors: Sun X. L. , Bradley S. T. , Jessen G. H. , Look D. C. , Molnar R. J. , Brillson L. J.
Published: November 2004

We have used cross-sectional micro-Auger electron spectroscopy (AES), coupled with micro-cathodoluminescence (CLS) spectroscopy, in a UHV scanning electron microscope to probe the chemical and related electronic features of hydride vapor phase epitaxy GaN/sapphire interfaces on a nanometer scale. AES images reveal dramatic evidence for micron-scale diffusion of O from Al2O3 into GaN. Conversely, plateau concentrations of N can extend microns into the sapphire, corresponding spatially to a 3.8eV defect emission and Auger chemical shifts attributed to Al-N-O complexes. Interface Al Auger signals extending into GaN indicates AlGaN alloy formation, consistent with a blue-shifted CLS local interface emission. The widths of such interface transition regions range from <100nmto∼1μm, depending on surface pretreatment and growth conditions. Secondary ion mass spectroscopy depth profiles confirm the elemental character and spatial extent of diffusion revealed by micro-AES, showing that cross-sectional AES is a useful approach to probe interdiffusion and electronic properties at buried interfaces.
Origin of H− in collisions of hydrogen atoms with an adsorbate-covered Cu(100) surface
Authors: DeFazio J. N. , Peko B. L.
Published: November 2004

Results are presented from an experimental study of electron capture and loss during collisions of low-energy hydrogen atoms and ions with a residual gas covered metal surface. Ground-state hydrogen atoms (H1s) and the atomic ions (H−,H+) were scattered from a Cu(100) surface with energies ranging from 25to200eV. Energy loss analysis indicates that the dominant process leading to H− formation proceeds directly through the adsorbed vacuum species, with the metallic crystal acting primarily as a physical scattering platform. In addition, ion beam experiments reveal effects due to the charge state of the incident particle that are inconsistent with the results expected for clean metal surfaces. Measurements indicate that the neutralization of incident ions as expected for clean metals is suppressed, a feature that is attributed to the band gap and dielectric strength of the adsorbed layer.
Suboxide characteristics in ultrathin oxides grown under novel oxidation processes
Authors: Lin Yen-Po , Hwu Jenn-Gwo
Published: November 2004

Interfacial suboxide (SiOx,0<x<2) between Si and its stable SiO2 is observed to be a key factor to affect the ultrathin-oxide quality. SiO2 grown by anodic oxidation (anodization) or by repeated-spike oxidation (RSO) presents a better dielectric characteristic than conventional rapid-thermal oxidation (RTO). This improvement can be attributed to two reasons: (1) A thinner transition region and/or (2) more stoichiometric S–O bonds under the same oxide thickness. Anodic SiO2 presents a thinner suboxide width (interface region) and RSO SiO2 demonstrates the existence of less suboxide existence at the near-surface region (oxide bulk). The reduction of the imperfect bonding structure in suboxide gives an abrupt Si–SiO2 interface and consequently, the reduction of electron tunneling probability through oxide.
Etching with electron beam generated plasmas
Authors: Leonhardt D. , Walton S. G. , Muratore C. , Fernsler R. F. , Meger R. A.
Published: November 2004

A modulated electron beam generated plasma has been used to dry etch standard photoresist materials and silicon. Oxygen–argon mixtures were used to etch organic resist material and sulfur hexafluoride mixed with argon or oxygen was used for the silicon etching. Etch rates and anisotropy were determined with respect to gas compositions, incident ion energy (from an applied rf bias) and plasma duty factor. For 1818 negative resist and i-line resists the removal rate increased nearly linearly with ion energy (up to 220nm∕min at 100eV), with reasonable anisotropic pattern transfer above 50eV. Little change in etch rate was seen as gas composition went from pure oxygen to 70% argon, implying the resist removal mechanism in this system required the additional energy supplied by the ions. With silicon substrates at room temperature, mixtures of argon and sulfur hexafluoride etched approximately seven times faster (1375nm∕min) than mixtures of oxygen and sulfur hexafluoride (∼200nm∕min) with 200eV ions, the difference is attributed to the passivation of the silicon by involatile silicon oxyfluoride (SiOxFy) compounds. At low incident ion energies, the Ar–SF6 mixtures showed a strong chemical (lateral) etch component before an ion-assisted regime, which started at ∼75eV. Etch rates were independent of the 0.5%–50% duty factors studied in this work.
Evolution of local texture and grain morphology in metal plasma immersion ion implantation & deposition of TiN
Authors: Manova D. , Attenberger W. , Mändl S. , Stritzker B. , Rauschenbach B.
Published: November 2004

The local crystallographic texture and grain orientation was investigated for deposition of TiN by metal plasma immersion ion implantation & deposition (MePIIID) at different ion incident angles across one sample. A very good match between the tilt of (fiber) texture and the tilt of grains was observed, indicating the validity of models for ion beam assisted deposition (IBAD) also for MePIIID. A (100) orientation was obtained for 5kV pulses at 9% duty cycle. The ion incident angle changed from near normal at the center towards 35° tilt away from the surface normal at the sample edge for the substrate orientation at 45° towards the cathode. However, due to the pulsed regime in MePIIID, there exist certain differences from IBAD.
Simple energy spike model for paracrystalline silicon in ion implantation
Authors: Cheng Ju-Yin , Gibson J. M.
Published: November 2004

A simple energy spike model is used to interpret the experimental results of medium-range order in ion-implanted amorphous silicon. This model can justify the liquid state, which is speculated to be the initial state of paracrystalline silicon in ion implantation. According to this model, we hypothesize that a crystallite is produced from the hottest spot of a liquid state. As solidification to an amorphous state proceeds from the boundary, the central spot undergoes the maximum undercooling. Such a condition can induce homogeneous crystallization, but it is not possible to form a perfect crystal therein. One can envisage that the spike finally becomes a paracrystallite. In support of the theory, we provide the key equations of the model in this article. But this model still needs to be verified by computer simulations in the future.
Effects of thermal annealing on the structural, mechanical, and tribological properties of hard fluorinated carbon films deposited by plasma enhanced chemical vapor deposition
Authors: Maia da Costa M. E. H. , Baumvol I. J. R. , Radke C. , Jacobsohn L. G. , Zamora R. R. M. , Freire F. L.
Published: November 2004

Hard amorphous fluorinated carbon films (a-C:F) deposited by plasma enhanced chemical vapor deposition were annealed in vacuum for 30min in the temperature range of 200–600°C. The structural and compositional modifications were followed by several analytical techniques: Rutherford backscattering spectrometry (RBS), elastic recoil detection analysis (ERDA), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Nanoidentation measurements and lateral force microscopy experiments were carried out in order to provide the film hardness and the friction coefficient, respectively. The internal stress and contact angle were also measured. RBS, ERDA, and XPS results indicate that both fluorine and hydrogen losses occur for annealing temperatures higher than 300°C. Raman spectroscopy shows a progressive graphitization upon annealing, while the surface became slightly more hydrophobic as revealed by the increase of the contact angle. Following the surface wettability reduction, a decrease of the friction coefficient was observed. These results highlight the influence of the capillary condensation on the nanoscale friction. The film hardness and the internal stress are constant up to 300°C and decrease for higher annealing temperatures, showing a direct correlation with the atomic density of the films. Since the thickness variation is negligible, the mass loss upon thermal treatment results in amorphous structures with a lower degree of cross-linking, explaining the deterioration of the mechanical properties of the a-C:F films.