bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between MMPs and pH in whole saliva of radiated head and neck cancer patients
Authors: Vuotila T. , Ylikontiola L. , Sorsa T. , Luoto H. , Hanemaaijer R. , Salo T. , Tjäderhane L.
Published: March 2003

Background: Radiation therapy for head and neck tumour patients may lead to decreased salivary flow, oral mucosal lesions and increased caries experience. Salivary matrix metalloproteinases (MMPs) may participate in the pathogenesis of mucosal lesions and dentinal caries. The aims of this study were: (i) to assay the presence, molecular forms and proteolytic activity of MMP‐8 (collagenase‐2) and MMP‐9 (gelatinase B) in the whole saliva of head and neck cancer patients having radiation therapy; (ii) to see whether salivary pH affects the activity of MMP‐8 and MMP‐9; and (iii) to find out the possible connection between MMP‐8 and MMP‐9 with the eruption of oral mucosal lesions during radiation therapy.

Methods: The whole saliva samples of 39 head and neck cancer patients having radiation therapy were collected before, during and after radiation therapy, and saliva flow rate, pH, buffer capacity, Streptococcus mutans, Lactobacillus and Candida albicans were measured. Any oral mucosal lesions were examined during each visit. The levels of MMP‐8 were measured by immunofluorometric assay (IFMA) and the presence of different MMP‐8 forms was analysed using Western immunoblotting. The presence and molecular forms of MMP‐9 were analyzed by gelatin zymography. MMP‐9 capture activity assay was used to determine the APMA‐activated MMP‐9 activity (total) and the endogenously active MMP‐9 (free activity).

Results: Salivary flow rate, buffer capacity and pH decreased, and the levels of Lactobacilli increased significantly, during the first half of the radiation therapy. The endogenously activated salivary MMP‐9 correlated with low salivary pH (P = 0.013). No connection was found between the oral mucosal lesions and salivary MMP‐8 or MMP‐9.

Conclusions: In this study, salivary MMP‐8 or MMP‐9 did not correlate with the presence of radiation induced oral mucosal lesions, but the activation of MMP‐9 may be dependent on pH.
Interleukin‐1β induces interleukin‐6 mRNA expression and protein production in synovial cells from human temporomandibular joint
Authors: Ogura Naomi , Tobe Makiko , Sakamaki Hiroyuki , Kujiraoka Hiroaki , Akiba Masakazu , Abiko Yoshimitsu , Nagura Hideaki
Published: March 2003

Background:  Interleukin (IL)‐1β and IL‐6 were found to be elevated in fluid from the temporomandibular joint (TMJ), although the source of these cytokines was not elucidated. There is little known about the function and response of synovial cells in the TMJ. The purpose of this study was to prepare cultured human synovial cells (HTS cells) from the TMJ and to investigate IL‐6 production in HTS cells incubated with IL‐1β.

Methods:  HTS cells were isolated from temporomandibular joint synovial tissue using an outgrowth method and then cultured in Ham's F12 medium containing 10% fetal bovine serum. The HTS cells were treated with or without IL‐1β for 3, 6, 9 and 24 h. IL‐6 and soluble IL‐6 receptor (sIL‐6R) levels in cultured supernatant were measured by ELISA. IL‐6 mRNA expression was investigated using immunocytochemistry and RT‐PCR.

Results:  HTS cells were morphologically heterogeneous. IL‐1β increased IL‐6 production in HTS cells. In those treated with IL‐1β, several cells were strongly stained in the cytoplasm around the nucleus, while several cells were weakly stained in this area. IL‐1β also stimulated IL‐6 mRNA expression. In contrast, sIL‐6R could not be detected in cells treated with or without IL‐1β.

Conclusions:  IL‐1β increased IL‐6 production in synovial cells resulting from an increase in IL‐6 mRNA expression. Enhanced production of IL‐6, which is associated with bone resorption and inflammatory response, seems to be related to the progression of TMJ disorders.
Calcifying odontogenic cyst: clinicopathological features and immunohistochemical profile of 10 cases
Authors: Fregnani Eduardo Rodrigues , Pires Fábio Ramôa , Quezada Rivera Daniel , Shih Ie Ming , Vargas Pablo Agustin , De Almeida Oslei Paes
Published: March 2003

Background:  Calcifying odontogenic cyst (COC) is an uncommon odontogenic lesion with few studies describing its immunohistochemical profile and proliferative activity reported in the literature.

Methods:  Clinical and histological features and immunohistochemical expression of cytokeratins, Mel‐CAM (CD146), bcl‐2, PCNA and ki‐67, in 10 cases of COC were studied.

Results:  All 10 cases affected the maxilla, eight intraosseous and two peripheral. Five central cases were cystic and three were cystic associated with odontoma, and the two extraosseous showed solid histological pattern; immunohistochemistry was positive for cytokeratins 8, 14, 19, AE1/AE3 and 34βE12 and bcl‐2 in all cases, and Mel‐CAM in six cases. Proliferative activity was greater in the epithelium of central cystic COC in relation to COC associated with odontoma and peripheral lesions.

Conclusion:  Calcifying odontogenic cysts showed odontogenic cytokeratin profile and bcl‐2 and Mel‐CAM expression indicate that these proteins may be involved in the development of COC. There were no recurrences after surgery, irrespective of their proliferative activity.
Le lecteur en procès: Analyse rhétorique du modèle judiciaire dans Les confessions de Rousseau
Authors: Brissette Pascal
Published: March 2003

Dès l'ouverture des Confessions, le lecteur est intégréà un procès qui oppose Rousseau à l'univers. Sous l'œil approbateur de l'« Être éternel », le narrateur se déclare essentiellement bon et sincère. Mais qu'en est‐il du lecteur, altérité construite à travers le discours qui occupe une position ambiguë, à la fois témoin et juge? Cet article cherche à montrer que les pages inaugurales des Confessions placent le lecteur dans une position inconfortable: est‐il ami ou ennemi, témoin bienveillant ou accusateur? Notre hypothèse est que, au contraire de ce que laisse croire le titre, ce n'est pas tant Rousseau qui est mis en procès, que le lecteur lui‐même, engagéà se « dévoiler », à avouer sa bienveillance ou son inimitiéà l'égard d'un narrateur ontologiquement innocent. L'analyse s'attachera à dégager un modèle judiciaire à trois instances (juge, accusé, accusateurs) et à mettre en lumière le glissement qui se produit dans la distribution initiale, le confessé se disculpant d'emblée par sa bonne foi et mettant en procès ses accusateurs. Nous examinerons plus particulièrement, à travers des épisodes comme celui du « vol du ruban », les schèmes argumentatifs et les topoï sur lesquels repose leur pouvoir persuasif.
Heinrich Manns Auseinandersetzung mit dem Haß: Eine Analyse der Henri Quatre‐Romane im Rahmen der exilbedingten Haßliteratur
Authors: Ireton Sean
Published: March 2003

Die Funktion des Hasses als Schreibmotor in der deutschen Exilliteratur wird anhand der Henri Quatre‐Romane von Heinrich Mann untersucht. Henris Haß gegen die katholische Liga entspricht dem der Exilanten gegen das nationalsozialistische Deutschland. Wie sein Geschöpf Henri, muß auch Heinrich Mann mit diesem erst lähmenden Gefühl des Hasses fertig werden, um produktiv gegen den Feind (wenn auch nur publizistisch) vorzugehen. Henris destruktiver Haß wird allmählich durch die Liebe zu Gabriele und zum französischen Volk überwunden. Diese Spannung zwischen Liebe und Haß ist ein wichtiges Problem nicht nur in den Henri Quatre‐Romanen, sondern durchzieht das Gesamtschaffen Heinrich Manns, vom frühen Professor Unrat bis hin zum Spätwerk Lidice. Zum Schluß zeigt eine vergleichende Analyse mit anderen zeitgenössischen Autoren (Thomas und Klaus Mann, Lion Feuchtwanger, u.a.), daß die Liebe/Haß‐Dialektik einen zentralen Platz in der Exilliteratur einnimmt und somit eine größere literarhistorische Thematik bildet.
Also sprach Confusius: Ein vergessenes Kapitel aus Nietzsches Wiener Frührezeption
Authors: Benne Christian
Published: March 2003

Blick in die Zukunft. – Was für ein Bein wird der Uebermensch haben? Ein Tanzbein? Tschandalagedanke! Ein Ueberbein! (Also sprach Confusius, 49)

Der Artikel beschreibt ein wiederentdecktes Dokument aus der Frühzeit der Nietzsche‐Rezeption. Es handelt sich um die anonym erschienene Nietzsche‐Parodie zweier Wiener Journalisten, die durch ihre satirische Technik eindrucksvoll die Verbreitung Nietzsches schon zu Beginn der 1890er Jahre erkennen lässt. Neben Darstellung und Bewertung von Also sprach Confusius wird den verschlungenen Wegen der frühen Nietzsche‐Rezeption nachgegangen, die nicht zuletzt über Dänemark führten. Nicht die Intensität der Rezeption unterschied die Aufnahme Nietzsches in Österreich und Deutschland, sondern die Art und Weise.
Mutant Alleles at the Brown Locus Encoding Tyrosinase‐Related Protein‐1 (TRP‐1) Affect Proliferation of Mouse Melanocytes in Culture	*
Authors: SARANGARAJAN RANGAPRASAD , ZHAO YANG , BABCOCK GEORGE , CORNELIUS JAMES , LAMOREUX M. LYNN , BOISSY RAYMOND E.
Published: March 2003

Tyrosinase related protein‐1 (TRP‐1) is a melanocyte‐specific gene product involved in eumelanin synthesis. Mutation in the Tyrp1 gene is associated with brown pelage in mouse and oculocutaneous albinism Type 3 in humans (OCA3). It has been demonstrated that TRP‐1 expresses DHICA oxidase activity in the murine system. However, its actual function in the human system is still unclear. The study was designed to determine the effects of mutation at two Typr1 alleles, namely the Tyrp1b (brown) and Tyrp1b‐cj (cordovan) compared with wild type Tyrp1B (black) on melanocyte function and melanin biosynthesis. The most significant finding was that both of the Tyrp1 mutations (i.e. brown expressing a point mutation and cordovan expressing decreased amount of TRP‐1 protein) resulted in attenuation of cell proliferation rates. Neither necrosis nor apoptosis was responsible for the observed decrease in cell proliferation rates of the brown and cordovan melanocytes. Ultrastructural evaluation by electron microscopic analysis revealed that both mutations in Tyrp1 affected melanosome maturation without affecting its structure. These observations demonstrate that mutation in Tyrp1 compromised tyrosinase activity within the organelle. DOPA histochemistry revealed differences in melanosomal stages between black and brown melanocytes but not between black and cordovan melanocytes. There were no significant differences in tyrosine hydroxylase activities of tyrosinase and TRP‐1 in wild type black, brown and cordovan melanocyte cell lysates. We conclude that mutations in Tyrp1 compromise cell proliferation and melanosomal maturation in mouse melanocyte cultures.
Tyrosine Levels Regulate the Melanogenic Response to α‐Melanocyte‐Stimulating Hormone in Human Melanocytes: Implications for Pigmentation and Proliferation
Authors: SCHWAHN DENISE J. , XU WEIDONG , HERRIN AMEY B. , BALES ELISE S. , MEDRANO ESTELA E.
Published: March 2003

Melanocyte‐stimulating hormone (α‐MSH) increases cytosolic levels of cAMP as well as tyrosinase activity in murine melanocytes. These activities depend upon the presence of melanin precursors and may differ in human melanocytes. In this study, we demonstrate that high levels of tyrosine (3.7 mM), the chief melanin precursor, reduced the proliferative effect of α‐MSH and altered human melanocyte morphology as compared to treatment with low (25–30 μM, half‐physiological) levels of tyrosine. The anti‐proliferative effect of high levels of tyrosine was not restricted to α‐MSH; tyrosine also reduced proliferation induced by forskolin, a direct activator of the cAMP pathway. Exposure to low tyrosine levels and α‐MSH induced a dendritic morphology; in the presence of high tyrosine and α‐MSH, melanocytes displayed large, pigmented cell bodies and less dendricity. Exposure to α‐MSH in the presence of low tyrosine for up to 9 days did not appreciably increase melanin levels, but culturing the human melanocytes in high levels of tyrosine with α‐MSH increased melanin levels 10–50‐fold, depending on the pigmentation background of the donor. A greater induction of melanin accumulation was observed in melanocytes derived from light‐skinned donors than was observed in cells obtained from dark‐skinned donors. The poor ability of α‐MSH to stimulate melanin synthesis was not caused by a lack of induction of melanogenic proteins, as α‐MSH increased the expression of microphthalmia (MITF), tyrosinase, dopachrome tautomerase (DCT), and Pmel‐17, compared to untreated cells or cells stimulated by phorbol ester alone, regardless of tyrosine levels. DCT levels were greatly induced by low tyrosine with α‐MSH, but were dramatically decreased by high tyrosine with α‐MSH. Interestingly, in this same medium (high tyrosine), MITF levels also decreased after 2 weeks and were barely detectable by the third week. Despite the absence of MITF at 3 weeks of treatment in high tyrosine medium, tyrosinase levels remained high, thereby suggesting that additional factors must be responsible for tyrosinase transcription in human melanocytes. Our results indicate that tyrosine levels can regulate the proliferative activity induced by α‐MSH, as well as the extent of melanogenesis in normal human melanocytes. The significance of this work is that tyrosine levels may be part of the mechanism that switches melanocytes out of a proliferative status and into a melanin‐synthesizing, terminally differentiated phenotype.
Redox Regulation in Human Melanocytes and Melanoma
Authors: Meyskens Jr. Frank L. , Farmer Patrick , Fruehauf John P.
Published: March 2003

The human melanocyte is continuously exposed to intrinsic and extrinsic sources of reactive biochemical species, but is finely tuned via the intrinsic anti‐oxidant and radical properties of melanin to suppress the build‐up of an altered redox phenotype. We propose that this control is lost during melanomagenesis and inappropriate redox‐sensitive transcriptional factor activations occur which result in enhancement of an anti‐apoptotic phenotype in the transformed cell. This conceptual framework offers testable steps to determine the role of redox alterations in the carcinogenic evolution, prevention and treatment of melanoma and other diseases of the melanocyte.
Over‐expression of MSG1 Transcriptional Co‐activator Increases Melanin in B16 Melanoma Cells: A Possible Role for MSG1 in Melanogenesis
Authors: Nair Sujit S. , Chaubal Vaishali A. , Shioda Toshi , Coser Kathryn R. , Mojamdar Manoj
Published: March 2003

MSG1 is a 27 kDa nuclear protein that is expressed strongly in melanotic B16 melanoma cells but very weakly in amelanotic B16 cells. Transient expression of B16 cells with an expression vector for MSG1 resulted in an increase in levels of the enzyme dopachrome tautomerase but not tyrosinase, as detected by western blotting. Stable transfection of B16 melanoma cells with plasmids containing the full length MSG1 or its deletion mutants, however, generated cell lines that showed an increase in levels of tyrosinase, dopachrome tautomerase and cellular melanin when compared with control transfected cells. Our results suggest that MSG1 plays an important role in melanogenesis, by regulating the levels of the enzymes of the pigmentary system via tyrosinase and dopachrome tautomerase.
RelA, p50 and Inhibitor of kappa B alpha are Elevated in Human Metastatic Melanoma Cells and Respond Aberrantly to Ultraviolet Light B
Authors: McNulty Susan E. , Tohidian Niloufar B. , Meyskens Frank L.
Published: March 2003

Metastatic melanomas are typically resistant to radiation and chemotherapy. The underlying basis for this phenomenon may result in part from defects in apoptotic pathways. Nuclear factor kappa B (NFκB) has been shown to control apoptosis in many cell types and normally functions as an immediate stress response mechanism that is rigorously controlled by multiple inhibitory complexes. We have previously shown that NFκB binding is elevated in metastatic melanoma cells relative to normal melanocytes. In the current study, Western blot analysis showed that, compared with normal melanocytes, melanoma cell lines have higher nuclear levels of the NFκB subunits p50 (7‐fold) and RelA (5–10‐fold). In response to tumor necrosis factor‐alpha (TNFα), both melanocytes and melanoma cells showed increased nuclear p50 and RelA levels, but levels in melanoma cells remained higher than in melanocytes. We also found that melanoma cells expressed higher cytoplasmic levels of RelA, p105/p50 and the inhibitory protein, inhibitor of kappa B alpha (IκBα) than melanocytes. To directly test whether RelA expression has an impact on melanoma cell survival, we used antisense RelA phosphorothioate oligonucleotides and found that melanoma cell viability was significantly decreased compared with untreated or control cultures. The constitutive activation of NFκB in metastatic melanoma cell cultures may, therefore, support an inappropriate cell survival pathway that can be therapeutically manipulated.
Stimulation of Melanogenesis by Tetradecanoylphorbol 13‐acetate (TPA) in Mouse Melanocytes and Neural Crest Cells
Authors: Prince S. , Wiggins T. , Hulley P. A. , Kidson S. H.
Published: March 2003

In vitro studies have shown that the phorbol ester, 12‐tetradecanoylphorbol 13‐acetate (TPA) induces neural crest cell differentiation into melanocytes, and stimulates proliferation and differentiation of normal melanocytes. As TPA is not a physiological agent, its action is clearly mimicking some in vivo pathway involved in these processes. An understanding of the effect of TPA on the expression of melanogenic genes will therefore provide valuable insight into the molecular mechanisms regulating melanocyte differentiation. In this study, we utilized primary cultures of neural crest cells and an immortalized melanocyte cell line (DMEL‐2) which proliferates in the absence of TPA, to explore the effects of TPA on key melanogenic effectors. In neural crest cells, TPA was found to be necessary for both microphthalmia associated transcription factor (Mitf) up‐regulation and for melanin synthesis. Using northern blots, we show that in DMEL‐2 cells, TPA significantly increases the messenger ribonucleic acid (mRNA) levels of the tyrosinase gene family (tyrosinase, Tyrp1 and Dct) and the expression of Mitf. Western blots demonstrate that in these TPA‐treated cells there is a concomitant increase in Tyr, Tyrp1 and glycosylated Dct protein levels. Pax3, a known Mitf regulator, is unaltered by TPA treatment. This study demonstrates the utility of a novel cell line for investigating the long‐term effects of TPA on melanogenesis and provides an understanding of how TPA enhances mouse melanocyte differentiation.
Regulation of Yellow Pigment Formation in Mice: A Historical Perspective
Authors: Wolff George L.
Published: March 2003

Pigment synthesis by hair follicle melanocytes is modulated by a large number of environmental and genetic factors, many of which are discussed in this review. Eumelanic (non‐yellow) pigment is produced by hair follicle melanocytes following the binding of alpha‐melanocyte stimulating hormone to melanocortin receptor 1. Binding of this hormone to the melanocyte membrane is blocked by agouti signaling protein (ASP) which is encoded by the agouti locus and results in the synthesis of yellow pigment, instead of non‐yellow (black/brown) pigment. The cyclical release of ASP by hair follicle cells results in a black/brown hair with a subapical yellow band. This is the wild‐type coat color pattern of many mammals and is called agouti. Several dominant mutations at the agouti locus in mice, induced by retrotransposon‐like intracisternal A particles, result in ectopic over‐expression of ASP and animals with much higher proportions of all‐yellow hairs. This abnormal presence of ASP in essentially all body cells results in the ‘yellow agouti obese mouse syndrome.’ The obesity has been associated with binding of ASP to melanocortin receptor 4 inactivating the latter. The syndrome also includes hyperinsulinemia, increased somatic growth, and increased susceptibility to hyperplasia and carcinogenesis. The physiologic and molecular bases for these syndrome components have not yet been elucidated. This historically orientated review is subdivided, where applicable, into pre‐ and post‐1992 subsections to emphasize the impact of the cloning of the agouti and extension loci and their protein products on the identification of the molecular and physiological pathways modulating the manifold aspects of pheomelanogenesis.
Patterns of cytokeratin expression in monkey and human periodontium following regenerative and conventional periodontal surgery
Authors: Sculean A. , Berakdar M. , Pahl S. , Windisch P. , Brecx M. , Reich E. , Donos N.
Published: March 2003

The pattern of cytokeratin expression has been extensively described in the normal and inflamed periodontium. However, there is no information regarding the pattern of cytokeratin expression in the periodontium which has been reformed following regenerative periodontal surgery. The aim of the present investigation was to evaluate the pattern of cytokeratin expression in the reformed human and monkey periodontium following regenerative and conventional periodontal surgery. In 3 monkeys, acute fenestration‐type and chronic intrabony defects were treated with guided tissue regeneration (GTR), enamel matrix proteins (EMD), or coronally repositioned flap surgery (control). After a healing period of 5 months, the animals were sacrificed and perfused with 10% buffered formalin for fixation. Specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. Histological sections were cut with the microtome set at 3 μm. The sections were alternatively stained either with hematoxylin and eosin, or immunohistochemically by using one of the broad range monoclonal antibodies 34βE12 (for cytokeratins 1, 5, 10 and 14) or KL1 (for cytokeratins 1, 2, 5, 6, 7, 8, 10, 11, 16 and 19), or one of the individual monoclonal antibodies LL025 (for cytokeratin 16), DC 10 (for cytokeratin 18), A53‐B/A2 (for cytokeratin 19). Twelve patients, each displaying one deep intrabony defect scheduled for extraction due to advanced periodontitis or prosthetic reasons, were treated as described above. Following a healing period of 6 months, the teeth were extracted together with some of their surrounding soft and hard tissues. The histological and immunohistochemical processing of the human biopsies was identical to that described in monkeys. The results revealed that both the normal non‐treated (original) monkey and human junctional epithelium stained strongly with all of the monoclonal antibodies used. The reformed junctional epithelium displayed the same cytokeratin expression pattern as the non‐treated junctional epithelium. No differences regarding the cytokeratin expression pattern of the junctional epithelium were found between the treatments and types of healing (i.e. regenerative, through a new periodontal ligament, or reparative through a long junctional epithelium). In the intact periodontal ligament, the epithelial rests of Malassez displayed a comparable cytokeratin expression pattern to that of the junctional epithelium. However, no expression of cytokeratins was seen in the newly formed periodontal ligament. In such specimens, cytokeratin expression was observed only until the
In vitro kinetic evaluation of titanium alloy biodegradation
Authors: Sedarat Cyril , Harmand Marie‐Françoise , Naji Abdes , Nowzari Hessam
Published: March 2003

The present controlled in vitro experiment evaluated the dissolution kinetics of titanium (Ti), aluminum (Al) and vanadium (V). Titanium alloy (Ti90Al6V4) dental implants were inserted in 1.8 ml sterile tubes, containing equal volumes of NaCl 0.9%(w/v) and human serum. Metallic elements released by the atomic process of corrosion were measured at pH 7.2 and 37°C by atomic absorption spectrophotometer at 1, 3, 6, 9, 15, 21, 27, 33, 42, 51, 60, 69, 78, 87 and 96 days. Ti dissolution averaged 16±5 ng/cm2/day and 1565 ng/cm2 over the experimental period. Al dissolution was stable at 9±5 ng/cm2/day and averaged 945 ng/cm2 over the 96‐day period. V dissolution was stable at 0.15±0.18 ng/cm2/day after the sixth day of incubation and averaged 42 ng/cm2 over the 96‐day period. Major disparities in atomic dissolution were detected among implants. No local or systemic reaction to titanium has been documented. In contrast, 4% toxic V and 6% Al may suffice to elicit local and systemic reactions or inhibit cellular proliferation and differentiation.
Localized antimicrobial peptide expression in human gingiva
Authors: Dale Beverly A. , Kimball Janet R. , Krisanaprakornkit Suttichai , Roberts Frank , Robinovitch Murray , O'Neal Robert , Valore Erika V. , Ganz Tomas , Anderson G. Mark , Weinberg Aaron
Published: March 2003

The stratified epithelia of the oral cavity are continually exposed to bacterial challenge that is initially resisted by innate epithelial factors and by the recruitment of neutrophils. Antimicrobial peptides from phagocytes and epithelia contribute to this antimicrobial barrier. Using antibodies and in situ hybridization, we explored antimicrobial peptide expression in the varied epithelia of the periodontium and in cultured gingival epithelial cells. In gingival tissue, mRNA for the β‐defensins, human beta‐defensin 1 (hBD‐1) and human beta‐defensin 2 (hBD‐2) was predominately localized in suprabasal stratified epithelium and the peptides were detected in upper epithelial layers consistent with the formation of the stratified epithelial barrier. In cultured epithelial cells, both hBD‐1 and ‐2 peptides were detected only in differentiating, involucrin‐positive epithelial cells, although hBD‐2 required stimulation by proinflammatory mediators or bacterial products for expression. β‐defensins were not detected in junctional epithelium (JE) that serves as the attachment to the tooth surface. In contrast, α‐defensins and cathelicidin family member LL‐37 were detected in polymorphonuclear neutrophils (PMNs) that migrate through the JE, a localization that persists during inflammation, when the JE and surrounding tissue are highly infiltrated with PMNs. Thus, the undifferentiated JE contains exogenously expressed α‐defensins and LL‐37, and the stratified epithelium contains endogenously expressed β‐defensins. These findings show that defensins and other antimicrobial peptides are localized in specific sites in the gingiva, are synthesized in different cell types, and are likely to serve different roles in various regions of the periodontium.
Plasminogen activating capacity in gingival fluid from deteriorating and stable jreiodontal pockets
Authors: Olofsson Anna , Matsson Lars , Kinnby Bertil
Published: March 2003

The plasminogen activating system plays an important role in tissue proteolysis in physiological as well as pathological processes. Earlier studies have shown high concentrations of the plasminogen activator t‐PA as well as its inhibitor PAI‐2 in gingival crevicular fluid (GCF). In addition, gingival inflammatory reactions have been related to increases in t‐PA and PAI‐2. In order to explore the potential role of the plasminogen activating system for the development of destructive jreiodontal disease, the aim of this study was to assess the balance of the activator t‐PA to the inhibitor PAI‐2 in GCF from patients, clinically defined to represent different jreiodontal conditions. The Progression Group consisted of 12 jreiodontitis patients with 1 or more sites having shown an increased pocket depth of ≥3 mm during the last 2 years of maintenance care and with ≥8 unchanged or improving sites during the jreiod. The Non Progression Group consisted of patients who had shown a decreased or unchanged pocket depth of all sites during the last 3 years of maintenance care. Sampling of GCF was done with small disks of Millipore‐filter, and t‐PA and PAI‐2 were analyzed with ELISAs. There was no difference in the t‐PA/PAI‐2 ratio between the two groups. However, an intra‐individual comparison within the Progression Group showed a higher ratio at the deteriorating sites than at the stable sites. Even though no difference was found between the groups, the higher t‐PA/PAI‐2 ratio at the deteriorating sites in the Progression Group suggests an involvement of the plasminogen activating system in the proteolytic events leading to breakdown of the tooth supporting tissues.
Release and activation of matrix metalloproteinase 8 from human neutrophils triggered by the leukotoxin of Actinobacillus actinomycetemcomitans
Authors: Claesson R. , Johansson A. , Belibasakis G. , Hänström L. , Kalfas S.
Published: March 2003

Matrix metalloproteinase 8 (MMP 8) degrades type I collagen and may be involved in the pathogenesis of periodontitis. Latent MMP 8 is stored in neutrophil granules and can be activated when released extracellularly. The periodontitis‐associated bacterium Actinobacillus actinomycetemcomitans produces an RTX‐toxin, leukotoxin, that degranulates and lyses human neutrophils. This study deals with the ability of leukotoxic A. actinomycetemcomitans to trigger the release and activation of MMP 8. Whole bacteria of three A. actinomycetemcomitans strains or leukotoxin purified from the highly toxic strain HK 1519 were incubated with human neutrophils. The extracellularly released latent and active forms of MMP 8 were detected by an immunoblot technique using specific antibodies against the protease. The activity of MMP 8 was determined by a collagen degradation assay. All strains induced release and activation of MMP 8. The effect was more pronounced under aerobic than anaerobic conditions and correlated with the leukotoxicity of the strains. Pure leukotoxin also induced MMP 8 release and activation in a concentration‐dependent manner. Under aerobic conditions, oxidising substances formed by the neutrophils contributed to the rapid activation of the latent enzyme. Upon anaerobic incubation, the activation was slow and mainly caused by other proteases released during neutrophil degranulation. The activation was totally abolished in the presence of serum, probably due to the serum‐protease inhibitors. Compared to the calcium ionophore A 23187, a well‐known stimulus of neutrophil degranulation, leukotoxin was a more powerful inducer of MMP 8 release, since it triggered the process at a 1000‐fold lower concentration. The present findings reveal a specific mechanism that can be induced by A. actinomycetemcomitans leukotoxin and which may contribute to the degradation of periodontal tissues under certain conditions.
Effects of hippocampal lesioning on experimental periodontitis in Wistar rats
Authors: Breivik T. , Thrane P. S. , Gjermo P. , Cools A. , Myhrer T.
Published: March 2003

The hippocampus, which is a brain structure involved in learning and memory processes, plays a key role in the feedback regulation of the hypothalamic‐pituitary‐adrenal (HPA) axis and autonomic sympathetic nervous system, and the subsequent secretion of immuno‐modulatory hormones in response to pathogenic microorganisms. Dysregulation of these brain‐neuroendocrine‐immune regulatory networks, which act in concert to maintain homeostasis, is found to be of critical importance to the host defence against pathogens, as well as susceptibility to diseases, including periodontal disease. The present study was designed to determine the effects of hippocampal lesioning on the progression of periodontitis. Experimental ligature‐induced periodontitis was induced in 16 Wistar rats, which were bilaterally lesioned in their hippocampal region with an aspiration technique that is well documented to impair learning and memory, as well as in 15 sham‐operated control rats. The disease progression was evaluated radiographically and histometrically. The results revealed that the hippocampal lesioned rats developed significantly more destruction of the periodontium than did the sham‐operated controls. This finding supports recent studies that indicate that inappropriate brain‐neuroendocrine regulation of inflammatory responses to infectious agents may play an important role in disease susceptibility and progression.
Tensile strength, histological and immunohistochemical observations of periodontal wound healing in the dog
Authors: Werfully S. , Areibi G. , Toner M. , Bergquist J. , Walker J. , Renvert S. , Claffey N.
Published: March 2003

This study was designed to study wound strength at the dentine/connective tissue interface and at the bone/connective tissue interface following full thickness flap surgery. Flaps of uniform dimension were outlined in four young adult beagle dogs using a standardised double bladed knife and vertical incisions 10 mm apart, which extended 8 mm apical to the gingival margin. Bone was removed from half the sites (eight sites in each dog), giving 32 flaps replaced on dentine and 32 sites on bone. A tensile force was applied using a microprocessor force gauge at 1, 2, 3, 7, 10, 14, 21, and 28 days. Mean tensile strengths were markedly weaker for the dentine/flap interface. At 7 days the value for flaps to dentine was 1.82 N, in contrast to 5.08 N for flaps replaced on bone. Inflammatory cell counts tended to fall markedly at 3 days for both modalities, but were higher for the dentine/flap modality at all time points. Fibroblast density peaked at 7–14 days but did not vary with type of flap over the time points studied. The amounts of fibrin were greater for the dentine/flap interface at all time points but decreased for both flap types as time progressed. Collagen type V was localised to the basement membrane and blood vessels and tended to show more foci for flaps replaced on dentine. Procollagen levels showed little change over the healing interval for both flap/bone and flap/dentine interfaces. Type III collagen synthesis was at peak levels during the first week. These findings would support efforts to stabilise periodontal flaps at early time points, especially those on dentine.
Anti‐TGF‐β antibody blocks enamel matrix derivative‐induced upregulation of p21WAF1/cip1 and prevents its inhibition of human oral epithelial cell proliferation
Authors: Kawase Tomoyuki , Okuda Kazuhiro , Yoshie Hiromasa , Burns Douglas M.
Published: March 2003

We have previously demonstrated that porcine enamel matrix derivative (EMD) contains TGF‐β1 (or a TGF‐β‐like substance), and that EMD rapidly translocates smad2, which is an effector of the TGF‐β signaling pathway, into the nucleus and modulates the proliferation of both human gingival fibroblastic and oral epithelial cells in a cell type‐specific manner. To investigate the involvement of TGF‐β in the growth modulatory action of EMD, two approaches have been used in the present study: i) a neutralizing anti‐TGF‐β antibody to block EMD action, and ii) authentic porcine TGF‐β1 to compare with EMD. Both in epithelial and fibroblastic cells, TGF‐β1 closely mimicked EMD in nuclear accumulation of smad2, phosphorylation of MAP kinase family members, and consequent cell type‐specific growth modulation. Anti‐TGF‐β antibody, at levels which completely blocked TGF‐β1‐induced smad2 translocation, strongly blocked EMD‐induced smad2 translocation. This antibody also blocked other actions of EMD in epithelial cells, i.e. p38‐MAP kinase (p38‐K) phosphorylation, p21WAF1/cip1 expression, and inhibition of DNA synthesis. In support of our previousproposal,thesedatasuggest that TGF‐β1 (or a TGF‐β‐like substance), which is delivered as a principal bio‐active factor in EMD, inhibits epithelial cell proliferation probably by a smad2‐mediated, p21WAF1/cip1‐dependent mechanism. However, the same neutralizing antibody failed to convincingly block EMD‐induced fibroblastic proliferation, which suggests that EMD may contain additional unidentified mitogenic factor(s), which act in combination with TGF‐β to fully stimulate fibroblastic proliferation.
Effects of safrole on the defensive functions of human neutrophils
Authors: Hung Shan‐Ling , Chen Yu‐Ling , Chen Yen‐Ting
Published: March 2003

The effects of safrole on the defensive functions of human neutrophils were examined. At the concentrations employed in this study, safrole did not significantly affect the viability of peripheral blood neutrophils as verified by their ability to exclude trypan blue dye. However, exposure of neutrophils to safrole inhibited their bactericidal activity against oral pathogens, including Actinobacillus actinomycetemcomitans and Streptococcus mutans, in a dose dependent manner. In addition, safrole inhibited the production of bactericidal superoxide anion by neutrophils as measured by cytochrome c reduction. In conclusion, the results demonstrated that safrole reduced the antibacterial activity and the superoxide anion production of neutrophils. Inhibition of the defensive functions of neutrophils may be one possible mechanism by which safrole compromises the oral health.
Combined TUNEL and TRAP methods suggest that apoptotic bone cells are inside vacuoles of alveolar bone osteoclasts in young rats
Authors: Cerri P. S. , Boabaid F. , Katchburian E.
Published: March 2003

Although it is generally accepted that osteoclasts breakdown and resorb bone matrix, the possibility that they may also be able to engulf apoptotic osteoblasts/lining cells and/or osteocytes remains controversial. Apoptosis of osteoblasts/ lining cells and/or osteocytes and interactions between these cells and osteoclasts are extremely rapid events that are difficult to observe in vivo. A suitable in vivo model for studying these events is the alveolar bone of young rats because it is continuously undergoing intense resorption/remodeling. Thus, sections of aldehyde fixed alveolar bone of young rats were stained by the combined terminal deoxynucleotidyl transferase‐mediated dUTP nick end labeling (TUNEL) method and the tartrate‐resistant acid phosphatase (TRAP) method for the simultaneous visualization of apoptotic cells and osteoclasts in the same section.

The combined TUNEL and TRAP reactions, in the same section, greatly facilitated visualization of relationship between osteoclasts and apoptotic bone cells during alveolar bone remodeling. Our results showed that several TRAP‐positive osteoclasts exhibited large vacuoles containing TUNEL positive apoptotic structures, probably derived from osteoblasts/lining cells and/or osteocytes. These results support the idea that alveolar bone osteoclasts are able to internalize dying apoptotic bone cells.
Ecstasy during Loud Noise Exposure Induces Dramatic Ultrastructural Changes in the Heart
Authors: Gesi Marco , Soldani Paola , Lenzi Paola , Ferrucci Michela , Giusiani Alberto , Fornai Francesco , Paparelli Antonio
Published: March 2003

Abstract: The acute toxicity induced by 3,4‐methylenedioxymethamphetamine appears as rabdomyolysis involving the myocardium (myocytolysis) and it is often suspected to be responsible for sudden death. In line with this, cardiac symptoms such as tachycardia, hypertension, and arrhythmia are present in persons abusing ecstasy. In most cases, ecstasy is abused in loud noise, which in itself might affect the myocardium. To our knowledge no study has investigated the concomitant exposure to ecstasy and loud noise in order to evaluate the role of the loud noise in modulating MDMA toxicity. In the present study, we analyzed whether cardiac effects following a typical “binging” pattern of MDMA administration are enhanced by concomitant exposure to loud noise. Our findings did not show any myocardial lesion detectable under light microscopy. In contrast, alterations were visible at the ultrastructural level as mitochondrial changes. In particular, we found a marked enhancement in the number of altered mitochondria when MDMA was administered during exposure to loud noise.
Separate Effects of 1,25‐Dihydroxyvitamin D and Calcium on Renal Calbindin‐D28k and Intestinal Calbindin‐D9k
Authors: Hemmingsen Claus , Staun Michael , Nielsen Palle K. , Olgaard Klaus
Published: March 2003

Abstract: The effects of normal, low and high plasma concentrations of 1,25‐(OH)2vitamin D (1,25‐(OH)2D) combined with normal, low and high concentrations of plasma calcium on renal calbindin‐D28k and intestinal calbindin‐D9k were examined in rats. We found that the expression of renal calbindin‐D28k was significantly (P<0.05) increased by high levels of 1,25‐(OH)2D, but was not affected by a 50% reduction in 1,25‐(OH)2D. In contrast the intestinal calbindin‐D9k responded significantly (P<0.005) to both high and low 1,25‐(OH)2D levels. The effect of 1,25‐(OH)2D on intestinal calbindin‐D9k was modulated by plasma calcium concentrations. Increased plasma calcium levels did not affect the renal calbindin‐D28k concentrations, but suppressed intestinal calbindin‐D9k (P<0.05). The effect of calcium was not mediated by calciotropic hormones. This suggests the existence of a calcium‐sensing mechanism in the proximal duodenum. It is concluded that intestinal calbindin‐D9k is more sensitive than renal calbindin‐D28k to changes in 1,25‐(OH)2D and that intestinal calbindin‐D9k in contrast to renal calbindin‐D28k is sensitive to changes in plasma calcium concentrations.
Gastrin Agonists and Antagonists
Authors: Black James W. , Kalindjian S. Barret
Published: March 2003

Abstract: This review generally describes work in the area of CCK2 or gastrin receptor agonists and antagonists before focussing on highlights of studies in these areas carried out at the James Black Foundation over the last dozen years. Thus, an alanine scan of BOC‐tetragastrin coupled with a bioassay in the isolated mouse stomach led to new insights as to the nature of the function of the various residues of the peptide. This in turn produced molecules such as the peptoid, JB 90118 which was an antagonist in all in vitro systems explored but was found to be CCK1 selective and an agonist still in vivo. We then go on to describe attempts to mimic a putative 310 helical conformation for BOC‐tetragastrin which had been suggested by fluorescence studies. Structures based on the dibenzobicylo[2.2.2]octane skeleton appeared to fulfil the requirements of the pharmacophore and promising initial results were obtained after the requisite molecules were synthesised. Optimisation of this series led to compounds with affinities in the nanomolar range but which were lacking in consistency when examined in vivo. Further manipulation, this time of the skeleton, led to molecules such as JB 93182 which were of equivalent affinity but with a better profile of action in vivo. It was found during exploration of the SAR of this new series that even relatively small alterations to the structure could give rise to molecules which behaved as agonists. Attempts to improve the oral bioavailability of JB 93182 by reduction of its molecular weight were aided by a molecular modelling approach which ultimately gave rise to another new series, some imidazole derivatives, exemplified by JB 98248.
The Role of Spinal Cholecystokinin in Chronic Pain States
Authors: Wiesenfeld‐Hallin Zsuzsanna , Xu Xiao‐Jun , Hökfelt Tomas
Published: March 2003

Abstract: It is well established that cholecystokinin (CCK) reduces the antinociceptive effect of opioids. The level of CCK and CCK receptors, as well as CKK release, exhibits considerable plasticity after nerve injury and inflammation, conditions known to be associated with chronic pain. Such altered CCK release coupled in some situation with changes in CCK receptor levels may underlie the clinical phenomenon of varying opioid sensitivity in different clinical pain conditions. In particular, neuropathic pain after injury to the peripheral and central nervous system does not respond well to opioids, which is likely to be caused by increased activity in the endogenous CCK system. CCK receptor antagonists may thus be useful as analgesics in combination with opioids to treat neuropathic pain.
A new method of phototesting before narrowband UVB therapy
Authors: Wishart J.
Published: March 2003

Narrowband UVB therapy is versatile and generally preferred to broadband sources. Recently, a convenient device has been described which gives 10 different doses simultaneously to the forearm to determine the minimal erythema dose (MED). It is known there is no relation between sun reactive skin type and MED. Twenty‐four individuals were tested using 26% increments giving a range of MED of between 0.38 J/cm2 and over 1.5 J/cm2. When compared to conventional window testing in 15 cases, it was found to be identical or within one increment.
Efficacy of ultraviolet A1 phototherapy on the expression of bcl‐2 in atopic dermatitis and cutaneous T‐cell lymphoma in vivo: a comparison study
Authors: Breuckmann F. , Von Kobyletzki G. , Avermaete A. , Kreuter A. , Altmeyer P.
Published: March 2003

Background/Purpose: Atopic dermatitis (AD) is characterized immunohistochemically by a high number of skin infiltrating T‐helper cells (CD4 + ). In most cases cutaneous T‐cell lymphoma (CTCL) is characterized by a malignant proliferation of CD4 +  T‐helper lymphocytes. The purpose of our study was to evaluate the extent of anti‐apoptotic effects in patients suffering from AD or CTCL, respectively, which may contribute to the prolonged inflammation. Furthermore, we investigated whether medium‐dose ultraviolet A1 (UVA1) phototherapy is able to modulate the expression of bcl‐2 within the dermal inflammatory infiltrate.

Methods: In order to enumerate bcl‐2+ cells pre‐ and post‐therapeutic punch skin biopsies of ten patients with AD and five patients with CTCL were stained immunohistochemically for features of apoptosis using a monoclonal antibody detecting bcl‐2.

Results: Both AD and CTCL sections revealed a high percentage of bcl‐2+ cells within the dermal perivascular infiltrate before therapy. After the successful treatment using medium‐dose UVA1 phototherapy this percentage could be decreased significantly.

Conclusion: Both T‐cell‐derived skin diseases exhibit an increased pre‐therapeutic number of bcl‐2+ cells. After medium‐dose UVA1 phototherapy the substantial improvement of the skin condition was linked to a significant decrease of the dermal bcl‐2+ cell count. Moreover, we could demonstrate a remarkable correlation referring to the decrease and staining pattern of bcl‐2 between these two groups as well as within each group. Because the bcl‐2 protein is known to act as an apoptosis inhibitor, its pre‐therapeutic increase may provide the persistent cutaneous inflammatory reaction in T‐cell‐derived skin diseases. Additionally, the post‐therapeutic reduction of bcl‐2+ cells might represent a key mechanism of medium‐dose UVA1 phototherapy.
Circadian variation of portal, arterial and venous blood levels of melatonin in pigs and its relationship to food intake and sleep
Authors: Bubenik G.A. , Pang S.F. , Cockshut J.R. , Smith P.S. , Grovum L.W. , Friendship R.M. , Hacker R.R.
Published: March 2003

Circadian levels of melatonin were determined in the hepatic portal vein, cranial vena cava, and the lower aorta of ten juvenile pigs. Blood was sampled every hour for a total of 24 hr via temporary cannulas introduced into blood vessels under anesthesia. No peak levels of melatonin were found in the mid‐scotophase, but hepatic portal concentrations peaked at 06.00 hr. Overall levels of melatonin were highest in the hepatic portal vein (range 35–65 pg/mL), followed by an artery (range 30–55 pg/mL) and the vena cava (range 25–35 pg/mL). Levels of melatonin exhibit strong variation between individual pigs, but generally the average levels from all three sources follow each other's time course. However, on occasion, melatonin levels in the hepatic portal vein varied independently from the levels in the vena cava. Large portal peaks were usually preceded by a feeding period and were associated with a subsequent period of sleep. The data indicate that: 1) there is no clear circadian rhythm of melatonin in the peripheral blood of pigs, 2) relatively little melatonin is metabolized during the first liver passage, 3) food intake may elevate melatonin levels in the hepatic portal vein, and 4) increased levels of melatonin originated in the gastrointestinal tract may induce sleep.