bluuebunny/crossref_metadata_2025 huggingface dataset:
The development and initial validation of the Liverpool sicca index to assess symptoms and dysfunction in patients with primary Sjögren's syndrome
Authors: Field E. Anne , Rostron Jocelyne L. , Longman Lesley P. , Bowman Simon J. , Lowe Derek , Rogers Simon N.
Published: March 2003

Background:  A validated measure to assess sicca‐related symptoms in patients with primary Sjögren's syndrome (1°SS) is required for clinical studies.

Methods:  A self‐administered questionnaire was developed to assess sicca‐related symptoms and dysfunction in 1°SS. This was administered to three groups of 40 respondents to measure construct validity: 1°SS patients, non‐SS patients reporting xerostomia and a non‐patient group. The frequency of scores and the mean score for each question were calculated for each group. Reliability was assessed by test/retest.

Results:  The measure consisted of 28 items divided into five domains. Scores for questions in domains were generally worse (higher) for 1°SS patients than for patients with xerostomia. The non‐patient group reported the best (lowest) scores for all questions. The Kappa statistic for all but four questions was greater than 0.6, suggesting good reliability.

Conclusion:  Questionnaire showed good construct validity and reliability. The Liverpool sicca index needs to be further validated in larger, multicentre studies.
’Yonder lies the grave‐island, the silent island; yonder, too, are the graves of my youth’: A Commentary on Zarathustra's Grave‐Song
Authors: Bishop Paul
Published: March 2003

This article places Nietzsche's central work, Also sprach Zarathustra, in the context of his insistence on the importance of interpretation. In the form of a short commentary, the author attempts to explore the significance of the chapter entitled ‘Das Grablied’ (The Grave‐Song), in order to show how our understanding of Nietzsche's work can benefit from closer textual analysis. Situating the chapter within the rest of Zarathustra, the commentary examines the language, cultural references, and imagery of ‘Das Grablied’, arguing that the technique of repetition and slight variation of phrases creates a continuity across the text and a density of feeling. Zarathustra's logic, we learn, does not proceed in logical stages, but rather emerges from his pronouncements across the text. Thus an argument which, at first sight, appears jumbled and incoherent, is revealed, by close reading, to possess an intellectual logic amid an increaslingly ecstatic intensity of expression. Read in detail and in context, ‘Das Grablied’ is shown to represent a major step in the argument of Zarathustra, for it sings of how we, too, can learn to love the earth and obey the injunction: bleibt der Erde treu!
Melanocyte Subpopulation Turnover During the Human Hair Cycle: An Immunohistochemical Study
Authors: COMMO STÉPHANE , BERNARD BRUNO A.
Published: March 2003

The human hair cycle is characterized by successive phases of growth and involution that imply tissue regression and regeneration. As a consequence, the hair melanin unit has to be renewed in a cyclic manner. Actually, the behavior of human hair follicle melanocytes throughout the hair cycle has been poorly studied. Thus, the origin of melanocytes present in the bulb after human hair regeneration is still not clarified, and neither are the events that control the melanin biosynthesis activity in the human hair bulb. In this study, we showed at the cellular level that in human pigmented hair follicles, the expression of tyrosinase and tyrosinase‐related protein‐1 (TRP‐1) was detectable during the anagen phases III/IV through VI, only in those melanocytes which were located in the bulb. During the catagen phase, the two evaluated melanogenic enzymes were detectable no more, although melanocytes were still present in the preceding bulbar area. The epithelial column of catagen follicles and the capsule of telogen follicles also contained inactive melanocytes as evidenced by pMel‐17 labeling. At the induction of a new anagen hair follicle, some melanocytes were committed to cell division, but only when located in the nascent bulb close to the dermal papilla. Our results emphasize the close relationship between melanogenesis and the hair cycle and suggest that in humans, melanogenesis is restricted to anagen hair follicles not because of the regulation of tyrosinase activity, but because of melanogenic enzyme expression, e.g., tyrosinase and TRP‐1. Furthermore, the fact that in the newly developing anagen hair follicles, cell‐division commitment and tyrosinase and TRP‐1 expression were observed in melanocytes only when located in the nascent bulb suggests a highly regio‐specific melanocyte stimulation in early the anagen phase.
Monoclonal Antibody‐Mediated Manipulation as a Tool for Dissecting Genetic Pathways Underlying Specific Embryonic Processes
Authors: Nishikawa Shin‐Ichi , Nishikawa Satomi
Published: March 2003

The technology to produce monoclonal antibody (mAb) is one of mainstays supporting current biology. Identification and isolation of a specific molecule in situations where many other molecules coexist is the most popular way of using this technology. Some mAb can trigger or suppress the function of a given molecule, thus having a potential for use in manipulating developmental processes. A decade ago, we demonstrated that embryonic components of pigment cell development could be manipulated by injection of a mAb that inhibits the function of the c‐Kit tyrosine kinase receptor (RTK) into pregnant mice. While we believe that no other methods were available at that time to freely trigger or suppress the function of such molecules as c‐Kit, molecular genetic technologies enabling the same task have been developed recently.

In this article, we want to give a general overview of our previous experience of using mAb for manipulating embryonic processes, and discuss the potential of this technology in the age of new molecular genetics.
Noradrenaline‐ and Melatonin‐Mediated Regulation of Pigment Aggregation in Fish Melanophores
Authors: Aspengren Sara , Sköld Helén Nilsson , Quiroga Gabriela , Mårtensson Lena , Wallin Margareta
Published: March 2003

The effects of melatonin and noradrenaline (NA) on bi‐directional melanosome transport were analysed in primary cultures of melanophores from the Atlantic cod. Both agents mediated rapid melanosome aggregation, and by using receptor antagonists, melatonin was found to bind to a melatonin receptor whereas NA binds to an α2‐adrenoceptor. It has previously been stated that melatonin‐mediated melanosome aggregation in Xenopus is coupled with tyrosine phosphorylation of a so far unidentified high molecular weight protein and we show that although acting through different receptors and through somewhat different downstream signalling events, tyrosine phosphorylation is of the utmost importance for melanosome aggregation mediated by both NA and melatonin in cod melanophores. Together with cyclic adenosine 3‐phosphate‐fluctuations, tyrosine phosphorylation functions as a switch signal for melanosome aggregation and dispersion in these cells.
Parotid salivary S‐IgA antibodies during exjreimental gingivitis in smokers and non‐smokers
Authors: Lie M. A. , Myint M. M. , Schenck K. , Timmerman M. F. , Van Der Velden U. , Van Der Weijden G. A. , Loos B. G.
Published: March 2003

Jresons who smoke display a less pronounced increase of gingival bleeding in the exjreimental gingivitis model as compared with non‐smokers. The aim of the present study was to investigate whether this could partly be explained by differences in levels of parotid total secretory IgA (S‐IgA) or parotid S‐IgA reactive with selected oral microorganisms. Parotid saliva samples were obtained from 11 smoking and 14 non‐smoking volunteers, at baseline, after 5 and 14 days of full mouth exjreimental gingivitis. Output levels of total S‐IgA and of specific S‐IgA reactive with cell extracts fromActinobacillus actinomycetemcomitans,Actinomyces naeslundii,Campylobacter rectus,Fusobacterium nucleatum,Porphyromonas gingivalis,Prevotella intermedia,Prevotella nigrescens,Peptostreptococcus micros,Streptococcus gordoniiandStreptococcus mutanswere determined in the samples by means of ELISA. Smokers and non‐smokers were found to have similar output levels (μg/min) of total S‐IgA, and the values did not significantly change during the exjreimental gingivitis trial. Parotid salivary outputs (units/min) of the bacteria‐specific S‐IgA at baseline and at days 5 and 14, were not different between smokers and non‐smokers; no changes were observed during the exjreimental gingivitis trial. The present observations indicate that total S‐IgA and bacteria‐specific S‐IgA in saliva are not main factors that can explain the less pronounced increase of gingival bleeding in the exjreimental gingivitis model in smokers as compared with non‐smokers.
Occlusal hypofunction causes changes of proteoglycan content in the rat periodontal ligament
Authors: Kaneko S. , Ohashi K. , Soma K. , Yanagishita M.
Published: March 2003

The biological functions of proteoglycans and glycosaminoglycans are closely associated with mechanical stress on the tissue. In order to reveal the relationship between proteoglycans in the periodontal ligament and mechanical stress such as occlusal stimuli, occlusal hypofunction of rat unilateral mandibular molars was induced by extraction of the opposing first, second and third maxillary molars. Immunohistochemical analyses were performed using antibodies for chondroitin sulfate, decorin, biglycan, heparan sulfate and keratan sulfate, and hyaluronic acid‐binding protein. Chondroitin sulfate, observed more strongly in the cervical side than in the apical side of the periodontal ligament of the unextracted sides of mandible, and uniformly present in the extracellular matrix of the periodontal ligament, decreased significantly from 1 wk post‐extraction of the antagonists, with a decrease in thickness and disarrangement in fibrous components. Decorin core protein, uniformly present in the periodontal ligament of the unextracted sides, decreased as early on as 2 d post‐extraction. Heparan sulfate, mainly localized on the cell surface of vascular endothelial cells and osteoclastic cells as well as in the extracellular matrix of the unextracted sides, decreased significantly in association with the decreased number of blood vessels and osteoclastic cells as early on as 2 d post‐extraction. Biglycan, keratan sulfate and hyaluronic acid, uniformly distributed in the periodontal ligament of the unextracted sides, showed little change after the extraction. These results demonstrate that occlusal hypofunction causes tissue remodeling of the periodontal ligament, with a significant decrease of chondroitin sulfate, decorin and heparan sulfate.
A fluorometric microassay for histamine release from human gingival mast cells
Authors: Zhao Zhen Z. , Sugerman Philip B. , Walsh Laurence J. , Savage Neil W.
Published: March 2003

Mast cells are important effector cells of the immune system. We describe a rapid and inexpensive microassay to determine histamine release from human gingival mast cells. The assay is based on the coupling of histamine with o‐phthalaldehyde (OPT) at a highly alkaline pH to form a fluorescent product. Using this assay with a sample volume of 10 μl/well in a 384 black well microplate, the histamine detection limit was 0.031 μg/ml. The human mast cell line (HMC‐1) and fresh mast cells isolated from human gingival tissue (n=10) were stimulated with substance P, anti‐IgE or calcium ionophore A23187. Calcium ionophore significantly increased histamine release from HMC‐1 cells and gingival mast cells (p<0.05). This microassay will facilitate the study of mast cell histamine release in diseased oral mucosa.
Effects of glucose on formation of cytotoxic end‐products and proteolytic activity of Prevotella intermedia, Prevotella nigrescens and Porphyromonas gingivalis
Authors: Saito Kaoru , Takahashi Nobuhiro , Horiuchi Hiroshi , Yamada Tadashi
Published: March 2003

Black‐pigmented bacteria which produce cytotoxic metabolic end‐products and cell membrane‐associated proteases have been reported to play an important role in the pathogenesis of periodontal diseases. These bacterial virulence factors can be modified by the environmental conditions including nutrients supplied variously into the oral cavity. Although glucose is one of the most essential nutrients for oral bacteria, the exogenous supply of glucose may be discontinuous and the glucose concentration in a periodontal pocket may be influenced by the depth of the periodontal pocket. Therefore, effects of glucose as an environmental factor on the virulence factors of Prevotella intermedia, Prevotella nigrescens and Porphyromonas gingivalis were studied. When grown in the presence of glucose, both P. intermedia and P. nigrescens markedly decreased the production of cytotoxic end‐products including succinate, isobutyrate, isovalerate and ammonia, although their growth was increased. Furthermore, the proteolytic activities such as immunoglobulin‐, albumin‐ and casein‐degrading activities of these bacteria were decreased in the presence of glucose. On the other hand, no effect of glucose on the metabolic activity of P. gingivalis was observed. These results suggest that pathogenicity of P. intermedia and P. nigrescens may be decreased by the presence of glucose.
Merkel‐like cells in Malassez epithelium in the periodontal ligament of cats: an immunohistochemical, confocal‐laser scanning and immuno electron‐microscopic investigation
Authors: Tadokoro O. , Maeda T. , Heyeraas K. J. , Vandevska‐Radunovic V. , Kozawa Y. , Hals Kvinnsland I.
Published: March 2003

The cellular heterogeneity of Malassez epithelium (ME) residing in the periodontal ligament has recently been reported, and the presence and coexistence of the neuropeptides calcitonin gene‐related peptide (CGRP), substance P (SP) and vasoactive intestinal peptide (VIP) in single cells in ME has been shown (1). However, the identity of these neuroendocrine cells has so far not been verified. This study was undertaken in order to elucidate the identity of the neuroendocrine cells in ME by means of transmission electron microscopy, confocal scanning microscopy and immunohistochemistry using antibodies to protein gene product (PGP) 9.5 and cytokeratin 20 (CK). Gingival tissue was included in the study as a positive control for identification of Merkel‐like cells in oral epithelium. CK 20 immunopositive cells were present in both Malassez epithelium and in basal cell layers of gingival epithelium showing a distribution consistent with PGP 9.5 labelled cells in both epithelia. The results from PGP 9.5 immuno electron microscopy clearly evidenced the presence of single, intensely labelled cells and some nerve fibres invested between the Malassez epithelial cells. The conformity of the immunopositive cells in Malassez and gingival epithelium verified by double immunolabelling with PGP 9.5 and CK 20, indicates that the labelled neuroendocrine cells are identical in ME and in gingival epithelium. This demonstrates that Malassez epithelium not only exhibits neuroendocrine cells, but additionally that the neuroendocrine cells represent Merkel‐like cells.
Improvement of periodontal status by green tea catechin using a local delivery system: A clinical pilot study
Authors: Hirasawa Masatomo , Takada Kazuko , Makimura Masaharu , Otake Shigeo
Published: March 2003

The purpose of this study was to determine the usefulness of green tea catechin for the improvement of periodontal disease. The minimum inhibitory concentration (MIC) and bactericidal activity of green tea catechin against black‐pigmented, Gram‐negative anaerobic rods (BPR) were measured. Hydroxypropylcellulose strips containing green tea catechin as a slow release local delivery system were applied in pockets in patients once a week for 8 weeks. The clinical, enzymatic and microbiological effects of the catechin were determined. Green tea catechin showed a bactericidal effect against Porphyromonas gingivalis and Prevotella spp. in vitro with an MIC of 1.0 mg/ml. In the in vivo experiment, the pocket depth (PD) and the proportion of BPR were markedly decreased in the catechin group with mechanical treatment at week 8 compared with the baseline with significant difference. In contrast, PD and BPR were similar to the baseline and the value at the end of the experimental period in the placebo sites of scaled groups. The peptidase activities in the gingival fluid were maintained at lower levels during the experimental period in the test sites, while it reached 70% of that at baseline in the placebo sites. No morbidity was observed in the placebo and catechin groups without mechanical treatment. Green tea catechin showed a bactericidal effect against BPR and the combined use of mechanical treatment and the application of green tea catechin using a slow release local delivery system was effective in improving periodontal status.
Capsular polysaccharide from Actinobacillus actinomycetemcomitans inhibits IL‐6 and IL‐8 production in human gingival fibroblast
Authors: Ohguchi Yuko , Ishihara Yuichi , Ohguchi Masahiro , Koide Masanori , Shirozu Norimitsu , Naganawa Takahiro , Nishihara Tatsuji , Noguchi Toshihide
Published: March 2003

We previously reported that a capsular polysaccharide (CP) from Actinobacillus actinomycetemcomitans Y4 induces bone resorption in a mouse organ culture system and osteoclast formation in mouse bone marrow cultures. However, the effects of A. actinomycetemcomitans Y4 CP on human gingival fibroblasts (HGF) are still unclear. The present study was undertaken to test the hypothesis that A. actinomycetemcomitans Y4 CP alters the production of inflammatory cytokines, such as interleukin‐6 (IL‐6) and IL‐8 by HGF. When HGF were cultured with various concentrations of Y4 CP for 24 h, IL‐6 and IL‐8 production decreased in a concentration‐dependent manner. Y4 CP (100 μg/ml) suppressed the release of IL‐6 from 9.09 ± 0.08 ng/ml to 0.34 ± 0.21 ng/ml (P < 0.01) and IL‐8 production decreased from 3.76 ± 0.03 ng/ml to 0.09 ± 0.01 ng/ml (P < 0.01). Y4 CP suppressed 70–80% of the release of IL‐6 and IL‐8 from HGF stimulated with Y4 lipopolysaccharide (LPS), too. Interestingly, anti‐A. actinomycetemcomitans Y4 CP completely inhibited the effect of A. actinomycetemcomitans Y4 CP on IL‐6 and IL‐8 production from HGF. These results indicate that Y4 CP inhibits the release of IL‐6 and IL‐8 from HGF, suggesting that A. actinomycetemcomitans Y4 modulates the inflammatory response in periodontitis. Remarkably, this inhibitory effect was reversed by specific anti‐A. actinomycetemcomitans Y4 CP suggesting an important relationship between the organism and the humoral host response.
Influence of subcutaneous administration of recombinant TNF‐α on ligature‐induced periodontitis in rats
Authors: Gašperšič Rok , Štiblar‐Martinčič Draga , Osredkar Joško , Skalerič Uroš
Published: March 2003

Proinflammatory cytokine tumor necrosis factor alpha (TNF‐α) was found in inflamed periodontal tissues and many studies pointed to its significant role in development of periodontal disease. In this study, the influence of subcutaneously administered recombinant human TNF‐α (rhTNF‐α) on inflammatory reaction and periodontal breakdown in rats was analyzed during experimental periodontitis, induced by placing silk ligatures around the maxillary right second molar tooth. The rats were divided into two groups with five animals in each; the first group was infused subcutaneously with rhTNF‐α via osmotic pumps for 2 weeks and the second group was infused with phosphate‐buffered saline (PBS) in the same manner. Inflammatory reaction and periodontal breakdown was evaluated morphometrically on hematoxylin and eosin stained sections. Serum ionized calcium and inorganic phosphates were monitored colorimetrically. Serum calcium and phosphate levels were similar in rats receiving rhTNF‐α and PBS. Ligation resulted in accelerated periodontal breakdown, while subcutaneous rhTNF‐α administration by itself had no significant effect. Combined effect of subcutaneous rhTNF‐α administration and ligation resulted in a significantly greater inflammatory reaction and periodontal breakdown then either treatment alone. We concluded that the subcutaneous administration of rhTNF‐α accelerates the progression of experimental periodontitis in rats.
Induction of c‐fos expression by nicotine in human periodontal ligament fibroblasts is related to cellular thiol levels
Authors: Chang Yu‐Chao , Hsieh Yih‐Shou , Lii Chong‐Kuei , Huang Fu‐Mei , Tai Kuo‐Wei , Chou Ming‐Yung
Published: March 2003

Cigarette smoking is associated with increased incidence of periodontal disease and poor response to periodontal therapy. Several studies have shown the detrimental effects of nicotine on periodontal tissue. To investigate the molecular toxicological implications of cigarette smoking on periodontal tissue, expression of c‐fos early stress response gene was examined in human periodontal ligament fibroblasts (PDLFs) after exposure to nicotine. The exposure of quiescent human PDLFs to nicotine resulted in the induction of c‐fos mRNA expression. The levels of the c‐fos mRNAs increased about 2.5 and 4.8‐fold after exposure to 2.5 mm and 10 mm nicotine for 2 h, respectively. Moreover, the peak of c‐fos mRNA levels induced by nicotine was 5 mm at 2‐h incubation period. Kinetic investigations of c‐fos mRNA expression in nicotine‐treated cells revealed a rapid accumulation of the transcript, a significant signal first detectable after 30 min of exposure. This increase was transient and the level of c‐fos mRNAs returned rapidly to that of control cells by 8 h. To determine whether thiol levels were important in induction of c‐fos by nicotine, we pretreated cells with the glutathione (GSH) precursor, 2‐oxothiazolidine‐4‐carboxylic acid (OTZ), to boost thiol levels, or buthionine sulfoximine (BSO) to deplete GSH. Our results demonstrate that OTZ pretreatment decreased in c‐fos mRNA level and BSO pretreatment enhanced in c‐fos mRNA level after exposure to nicotine. In addition, nicotine significantly depleted intracellular GSH in a dose‐dependent manner (P < 0.05). At a concentration of 5 mm and 20 mm, nicotine depleted about 22.2% and 56% of GSH, respectively. Taken together, c‐fos gene expression might be one signal transduction pathway linked to the induction of early response genes by cigarette smoking. These results suggest that the nicotine‐dependent stress‐specific expression of the c‐fos gene correlates with cellular thiol levels in human PDLFs.
Estimation of interleukin‐1β levels in the gingival crevicular fluid in health and in inflammatory periodontal disease
Authors: Faizuddin Mohamed , Bharathi S. H. , Rohini N. V.
Published: March 2003

Initial research indicated that the levels of interleukin‐1β (IL‐1β) are higher in sites of inflammation than in healthy sites. However, subsequent studies suggest heterogenous responses and indicate the quantitative levels of IL‐1β to be the characteristic of an individual rather than simply being the reflection of the inflammatory status of the tissues. This study has been designed to find out the relationship between IL‐1β levels in the gingival crevicular fluid and the inflammatory status of the periodontal tissues in the Indian population. Sixty patients were selected for the study. They were categorized in to three groups based on their periodontal tissue status as group I (clinically healthy gingiva with no loss of attachment), group II (gingivitis with no attachment loss) and group III (gingivitis with attachment loss). Microcapillary pipettes were used to collect gingival crevicular fluid samples from one site in each person and the samples were analysed for IL‐1β using a commercially available ELISA kit. The concentration of IL‐1β in the gingival crevicular fluid of patients in group III is statistically higher (P < 0.0001) than that in group II and the concentration of IL‐1β in groups II and III is statistically at much higher levels (P < 0.0001) than in the group I subjects. However, there is a significant overlap in the values obtained in groups II and III and the values in both the groups range over a wide spectrum. The composite values obtained within the groups and the overlapping values in groups II and III could indicate the role of genetic polymorphism in determining the quantity of IL‐1β produced and also the contributory role of other cytokines that share similar biologic activity.
A TEM/SEM study of the microbial plaque overlying the necrotic gingival papillae of HIV‐seropositive, necrotizing ulcerative periodontitis
Authors: Cobb Charles M. , Ferguson Brett L. , Keselyak Nancy T. , Holt Lorie A. , MacNeill Simon R. , Rapley John W.
Published: March 2003

The purpose of this study was to examine by transmission (TEM) and scanning electron microscopy (SEM) the supragingival microbial plaque overlying the ulcerated gingival papillae of necrotizing ulcerative periodontitis (NUP) lesions in HIV‐seropositive patients. The microbiota of NUP and HIV‐seropositive patients with periodontitis has been reported to be similar to that of conventional periodontitis in non‐infected subjects, although several investigators have also reported high recovery rates of microbes not generally associated with the indigenous oral microbial flora. Light and electron microscopic observations and microbial culture studies indicate a similar high prevalence of spirochetes in both necrotizing ulcerative gingivitis (NUG) and NUP. In addition, several studies have reported more frequent isolation of Candida albicans from diseased periodontal sites in HIV‐seropositive patients than from non‐diseased sites. Ten male and six female patients, each HIV‐seropositive and exhibiting NUP, constituted the study population. Two biopsies of involved gingival papillae from between posterior teeth were obtained from each patient and processed for examination by both TEM and SEM. Microscopic examination revealed a surface biofilm comprised of a mixed microbial flora of various morphotypes in 81.3% of biopsy specimens. The subsurface flora featured dense aggregations of spirochetes in 87.5% of specimens. Zones of aggregated polymorphonuclear leukocytes and necrotic cells were also noted. Yeasts were observed in 65.6% of specimens and herpes‐like viruses in 56.5% of the specimens. Collectively, except for the presence of yeast and viruses, the results suggest that the microbial flora and possibly the soft tissue lesions of NUP and necrotizing ulcerative gingivitis are very similar.
Transgenic Mice Expressing Cholecystokinin 2 Receptors in the Pancreas
Authors: Clerc Pascal , Saillan‐Barreau Corinne , Desbois Christine , Pradayrol Lucien , Fourmy Daniel , Dufresne Marlène
Published: March 2003

Abstract: Several studies argue for the presence of CCK2 receptors in the human pancreas but their physiological role in normal exocrine pancreas and their contribution to pancreatic pathologies is unknown. In order to allow an easy investigation of their pancreatic function, we created the ElasCCK2 transgenic mice expressing the human receptor in pancreatic exocrine cells. In this model, the CCK2 receptor is specifically expressed in the exocrine pancreas and has typical molecular and binding features. It is functional and mediates enzyme release but stimulating concentrations of agonists are not physiological. Results of phenotypic and long‐term studies show that activation of CCK2 receptors stimulates growth of the pancreas in correlation with an increase of acinar tissue. This finding is also consistent with the demonstration of an efficient coupling of the transgenic receptor to protein synthesis. Alterations in pancreatic histology and development of preneoplastic lesions are apparent from postnatal day 50. Moreover, expression of this G‐protein‐coupled receptor leads to the development of tumours in older animals with an incidence of 15%. Although tumours have distinct phenotypes they all exhibit ductular strucures. Immunohistochemical analysis of these structures shows their acinar origin. These data, linking for the first time the development of pancreatic carcinogenesis in vivo to the expression of the CCK2 receptor, support a key role of the CCK2 receptor in the initiation of pancreatic cancer. Moreover, ElasCCK2 mice provide a model for carcinogenesis by transformation and dedifferentiation of acinar cells.
Extragastric Effects of Gastrin Gene Knock‐Out Mice
Authors: Koh Theodore J.
Published: March 2003

Abstract: Gastrin is a peptide hormone that regulates both acid secretion and growth of the gastric oxyntic mucosa. Recent studies suggest that gastrin, in both its amidated, and less processed forms (glycine‐extended gastrin and progastrin) may also exert biological activity in other organs in the gastrointestinal tract. This article will review the studies performed to date addressing the physiological role of gastrin outside of the gastric mucosa, with particular emphasis on the information gleaned from gastrin‐deficient mice. Most of these studies address the potential role for the less processed forms of gastrin in regulating the proliferation of the colonic mucosa and colon cancers. There is also some data to support a potential role for gastrin in the regulation of the pancreas and the kidney, although the effects of gastrin deficiency on the function of these organs in mice have not yet been rigorously studied.
Sunscreen protection in the ultraviolet A region: how to measure the effectiveness
Authors: Cole C.
Published: March 2003

Products containing ultraviolet (UV) radiation absorbing or scattering ingredients provide varying degrees of protection from sunlight (or other UV sources), thus minimizing the deleterious effects on the skin. The “sun protection factor” (SPF) of sunscreen products has become a well recognized indicator of protection against sunburn induced predominantly by ultraviolet B radiation (UVB: 290–320 nm). A similar system of denoting sunscreen protection from ultraviolet A (UVA: 320–400 nm) radiation has not been universally recognized. A variety of test methods have been proposed, both in vitro and in vivo, each with specific virtues and shortcomings. Regulatory agencies and industry have been reviewing the available methods over the past decade in an effort to develop consumer meaningful claims and appropriate substantiation methods. This article reviews these test methodologies, in vitro and in vivo, as well as the biological background that establishes the need for UVA protection, and the UVA content of solar radiation and its variability.
Xeroderma pigmentosum – bridging a gap between clinic and laboratory
Authors: Moriwaki Shin‐Ichi , Kraemer Kenneth H.
Published: March 2003

Xeroderma pigmentosum (XP) is an autosomal recessive photosensitive disorder with an extremely high incidence of UV‐related skin cancers associated with impaired ability to repair UV‐induced DNA damage. There are seven nucleotide excision repair (NER) complementation groups (A through G) and an NER proficient form (XP variant). XPA, B, D and G patients may also develop XP neurological disease. The laboratory diagnosis of XP can be performed by autoradiography. Recently, the isolation and characterization of the genes responsible for XP have made it possible to use molecular biological techniques to diagnose XP patients, for carrier detection and for prenatal diagnosis, especially in Japanese XPA patients. These techniques include polymerase chain reaction (PCR) and plasmid host cell reactivation assays with cloned XP genes. DNA damage is not repaired by the NER system equally throughout the genome. There are two DNA repair pathways: 1) transcription‐coupled repair, and 2) global genome repair. Many factors involved in these pathways are related to the pathogenesis of XP and a related photosensitive disease, Cockayne syndrome. Clinical management consists of early diagnosis followed by a rigorous program of sun protection including avoidance of unnecessary UV exposure, wearing UV blocking clothing, and use of sunblocks on the skin. Although there is no cure for XP, the efficacy of oral retinoids for the prevention of new skin cancers, local injection of interferon, and the external use of a prokaryotic DNA repair enzyme have been reported.
Effects of low dose ultraviolet A‐1 phototherapy on morphea
Authors: Gruss Claus J. , Von Kobyletzki Gregor , Behrens‐Williams Stefanie C. , Lininger John , Reuther Tilmann , Kerscher Martina , Altmeyer Peter
Published: March 2003

Aim:

The effects of low dose ultraviolet A‐1 (UVA‐1) phototherapy on different clinical stages of morphea (localized scleroderma) were analyzed in this case study. Based on these data, the different types of phototherapy described in the literature and currently used for treatment of morphea are compared.

Methods: Three patients with severe plaque type morphea in different stages were studied: one patient with late‐stage lesions having stable sclerotic plaques; another patient with active inflammatory lesions; and a third patient with late‐stage lesions associated with overlying lichen sclerosus et atrophicus (LSA). The treatment given was low dose UVA‐1 phototherapy with single doses of 20 J/cm2 administered four times a week for 6 weeks, and once a week for another 6 weeks.

Results: Following UVA‐1 phototherapy, the sclerotic plaques resolved, leaving smooth and soft tanned skin with normal structure, consistency and folding capability. In morphea with overlying LSA the elastic fibers did not completely return to the superficial papillary dermis despite the clinical clearance of both morphea and LSA. These data suggest that low dose UVA‐1 phototherapy may improve, but not completely reverse, the histopathological changes of LSA. No side effects were observed during or after treatment.

Conclusion: Our observations show in three patients that low‐dose UVA‐1 phototherapy is highly effective for treatment of all stages of morphea, including early inflammatory and late sclerotic lesions, and morphea with overlying lichen sclerosus et atrophicus. Because of its safety and efficacy, low dose UVA‐1 phototherapy appears to be the treatment modality of choice.
Genomic scale analysis of the human keratinocyte response to broad‐band ultraviolet‐B irradiation
Authors: Takao Joe , Ariizumi Kiyoshi , Dougherty Irene I. , Cruz Ponciano D.
Published: March 2003

Ultraviolet B (UVB) radiation is an important inducer of many biologic changes in skin, of which keratinocytes are a key target. To gain better insight into changes in gene expression generated in the early phase after UVB exposure, we used complementary RNA (cRNA) microarray hybridization to compare differences in mRNA expression of UVB‐irradiated (single dose of 100 J/m2 broad‐band UVB) and sham‐irradiated primary cultured human keratinocytes. Six hours after irradiation, total RNA was isolated from keratinocytes, and cRNA was synthesized and hybridized to a GeneChip expression array (Affymetrix) consisting of 6800 genes. Based on a threshold of > twofold change, 187 genes (2.8%) were designated to be the most UVB‐responsive. Surprisingly, none of these genes had been shown previously to be modulated by UVB. Conversely, several genes in the microarray that had been reported previously to be UVB‐ responsive by other methods showed less (< twofold) or no change. Northern blotting of seven differentially modulated genes produced results similar to those derived from microarray technology, thereby validating the accuracy of screening. Clustering based on known or likely functions indicated that among 88 upregulated genes, nine encode for cytochrome c subunits, six for ribosomal proteins, and two for regulators of apoptosis. By contrast, many of the 99 downregulated genes are involved in transcription, differentiation and transport. These findings indicate that keratinocytes respond to a single low dose of broad‐band UVB irradiation by enhancing processes involved in energy production and translation, while suppressing those related to transcription, differentiation and transport.
All‐night exposure to EMF does not alter urinary melatonin, 6‐OHMS or immune measures in older men and women
Authors: Graham Charles , Sastre Antonio , Cook Mary R. , Gerkovich Mary M.
Published: March 2003

Healthy men (n=22) and women (n=24), 40–60 years of age, were exposed all‐night (23:00–07:00 hr) to 60‐Hz magnetic fields at an intensity (resultant flux density=28.3 microTesla [μT]) well within the occupational‐exposure range, or sham exposed under equivalent, counter‐balanced, no‐exposure (≤0.2 μT) control conditions. Concentrations of melatonin, and the major metabolite of melatonin, 6‐hydroxymelatonin‐sulfate (6‐OHMS), in first‐void morning urine were not altered in either gender by exposure to the magnetic field, compared to control conditions. Statistical analysis also failed to reveal any evidence for exposure‐related alterations in blood concentrations of multiple hematologic and immune system parameters (CD3, CD4, CD8, natural killer [NK] cells). The present results replicate and extend earlier negative findings based on the exposure of young men to power‐frequency magnetic fields.
Direct comparison of the potency of three novel cAMP analogs to induce CREB‐phosphorylation in rat pinealocytes
Authors: Maronde Erik , Korf Horst‐Werner , Niemann Percy , Genieser Hans‐Gottfried
Published: March 2003

A modified analog of cyclic adenosine 3′,5′‐monophosphate (cAMP), Sp‐adenosine‐3′,5′‐monophosphorothioate, designed to be highly membrane‐permeable and resistant towards phosphodiesterases was found to induce the phosphorylation of the cAMP‐regulated transcription factor cyclic AMP‐responsive element binding protein in cultured rat pinealocytes more efficiently than previously described cAMP analogs.
2[125I]Iodomelatonin binding and interaction with β‐adrenergic signaling in chick heart/coronary artery physiology
Authors: Pang Celia S. , Xi Si C. , Brown Gregory M. , Pang Shiu F. , Shiu Stephen Y. W.
Published: March 2003

2[125I]Iodomelatonin ([125I]Mel) binding sites were characterized on membrane preparations of young chick hearts. [125I]Mel binding was rapid, saturable, stable, reversible, specific and of picomolar affinity and femtomolar density. Guanosine 5′‐O‐(3‐thiotriphosphate) significantly lowered the binding affinity by one‐ to twofold, supporting G‐protein linkage of melatonin receptors. Binding was detected as early as embryonic day‐9 (E9), and increased steadily peaking at E13 before it slowly declined to about 15% of the peak level a week posthatch. Specific [125I]Mel binding was significantly increased by in ovo administration of inotropic agents dopamine and isoproterenol. Melatonin or 2‐iodo‐N‐butanoyl‐tryptamine inhibited isoproterenol‐stimulated cAMP accumulation in primary heart cell cultures and the effect was attenuated after pretreatment with pertussis toxin (PTX). Localization of melatonin receptors using autoradiography showed intense labeling in the coronary arteries in all age groups whereas those in the myoblasts decreased as the heart matured. While the myoblasts and undifferentiated developing coronary arteries expressed melatonin MT1 receptor subtype in E11 hearts as detected by immunostaining with anti‐MT1 receptor serum, immunoreactivities were observed mostly on the endothelium/subendothelium and smooth muscle cells of the well developed coronary vessels in posthatch hearts. Collectively, our data suggest the presence of PTX‐sensitive, G protein‐coupled melatonin receptors, whose expression is up‐regulated by dopamine and isoproterenol, in the chick heart. Activation of these receptors, which include MT1 subtype, may modulate β‐adrenergic receptor‐mediated cAMP signaling in the control of chick heart and coronary artery physiology.
Melatonin attenuates MPP+‐induced neurodegeneration and glutathione impairment in the nigrostriatal dopaminergic pathway
Authors: Chen Shur Tzu , Chuang Jih Ing , Hong Mei Huei , Li Eric I‐Chian
Published: March 2003

In this study we selected a rat model of Parkinson's disease (PD) by using intrastriatal infusion of the 1‐methyl‐4‐phenyl‐pyridinium ion (MPP+) to investigate the neuroprotective action of melatonin and its inhibitory activity on MPP+‐impaired glutathione (GSH) system in the nigrostriatal system. Results show that MPP+ caused not only a severe neuronal injury in the striatum and in the ipsilateral substantia nigra (SN), but it also induced a significant decrease in GSH levels and an increase in the GSSG/GSH ratio 3 days after intrastriatal MPP+ infusion. Intraperitoneal co‐administration of melatonin (10 mg/kg, five times) significantly attenuated MPP+‐induced nigrostriatal neurotoxicity and GSH impairment. Depletion of cytosolic GSH by L‐buthionine sulfoximine (BSO) did not cause neuronal damage by itself. It, however, when co‐administrated with MPP+, potentiated the GSH reduction in the striatum, without aggravating nigrostriatal neurodegeneration induced by MPP+. Moreover, the MPP+‐caused neuronal damage was positively correlated with a rising ratio of GSSG/GSH, but not with a drop of GSH. These results suggest that the MPP+‐triggered oxidative stress may play a more important role than the loss of the antioxidant GSH in determining neuronal injury. Interestingly, the neuronal damage and oxidative stress elicited by co‐treatment of BSO with MPP+ were effectively reduced by melatonin. Our results hence provide direct evidence showing that melatonin attenuates MPP+‐induced nigrostriatal dopaminergic injury by its ability to impede the increase of GSSG/GSH ratio; therefore melatonin may have therapeutic implications in PD.
Melatonin's unique radical scavenging properties – roles of its functional substituents as revealed by a comparison with its structural analogs
Authors: Poeggeler Burkhard , Thuermann Sandra , Dose Andreas , Schoenke Markus , Burkhardt Susanne , Hardeland Rüdiger
Published: March 2003

Melatonin's O‐methyl and N‐acetyl residues are not only the basis of its amphilicity enabling the molecule to enter all organs and all subcellular compartments, but are also decisive for its antioxidant properties. We have compared melatonin's redox chemistry with that of several structural analogs: tryptamine, N‐acetyltryptamine, serotonin, N‐acetylserotonin, 5‐methoxytryptamine, 6‐chloromelatonin and 2‐iodomelatonin. Scavenging of hydroxyl radicals (·OH) was measured in a scavenger competition assay based on ABTS cation radical (ABTS·+) formation. The capability of undergoing single‐electron transfer reactions was studied using an ABTS·+ reduction assay, reflecting the more general property of scavenging organic cation radicals. Direct scavenging of superoxide anions (O2·−), under non‐catalyzed conditions, was investigated in a hematoxylin autoxidation assay. Measurements of chemiluminescence were used for studying scavenging of O2·− under catalyzed conditions, either by hemin‐mediated interaction or by combination with the respective indolyl cation radicals. Light emission was determined in the absence or presence of the ·OH scavenger dimethylsulfoxide and the O2·− scavenger Tiron. Products formed by oxidation of the respective indoles in a moderately alkaline, hemin‐catalyzed H2O2 system were analyzed by thin‐layer chromatography and fluorometry. Absence of either the O‐methyl or the N‐acetyl residue causes marked diminutions in the capacities of scavenging ·OH and ABTS·+ as well as in chemiluminescence emitted during oxidation. The importance of the N‐acetyl group is insofar remarkable as it seems, at first glance, to be isolated from the indolic moiety; interactions between side chain and indolic moiety are therefore decisive for melatonin's redox properties. The 5‐hydroxylated compounds are not generally more efficient scavengers, but particularly better reducers of ABTS·+; in the alkaline H2O2 system generating ·OH and O2·−, melatonin was much more rapidly oxidized than the 5‐hydroxylated and non‐substituted analogs. Oxidative products formed from any of the compounds studied contained much less of substituted kynuramines as in the case of melatonin, indicating that radical chain termination by O2·− is considerably more efficient with melatonin. These findings are supported by measurements of chemiluminescence, which largely reflects pyrrole ring cleavage as a result of combination with superoxide anions. In this regard, only 6‐chloromelatonin equalled melatonin, whereas the efficiency of 2‐iodomelatonin was much lower, another indication for the importance of 2,3‐dioxygenation.
The effect of melatonin on bleomycin‐induced pulmonary fibrosis in rats
Authors: Arslan Seyfullah O , Zerin Mustafa , Vural Huseyin , Coskun Ali
Published: March 2003

The present investigation was designed to determine the protective effects of melatonin against bleomycin (BLM)‐induced oxidant lung toxicity. Wistar‐albino rats were divided into four groups: saline (SA, 0.4 mL/animal), 1% ethanol‐saline (ALC, 0.4 mL/animal), bleomycin sulphate (BLM, 10 mg/kg), or bleomycin sulphate + melatonin (BLM, 10 mg/kg + MLT, 10 mg/kg). All injections were given intraperitoneally (i.p.), twice weekly for a period of 3 wk (a total of seven injections for each group). Twenty‐five days after BLM treatment, pulmonary fibrosis was assessed as hydroxyproline content in lung homogenates. Findings show that BLM‐induced pulmonary injury resulted in increases in bronchoalveolar lavage fluid (BALF) biomarkers including total protein, lactate dehydrogenase (LDH), glutathione‐peroxidase (GSH‐Px), superoxide dismutase (SOD), and catalase (CAT). Additionally, the levels of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation (LPO), were also increased in BALF. Conversely, the level of glutathione (GSH) was reduced in BALF of BLM‐treated rats. Melatonin provided protection against BLM‐induced pulmonary fibrosis by suppressing oxidative stress. It abolished BLM‐stimulated LPO and reversed the imbalance between oxidants and antioxidants in the BALFs. Results thus indicate that melatonin inhibits BLM‐induced lung toxicity associated with oxidative damage.
First cloning and functional characterization of a melatonin receptor in fish brain: a novel one?
Authors: Gaildrat Pascaline , Becq Frédéric , Falcón Jack
Published: March 2003

Melatonin, a neuroendocrine transducer of photoperiod, influences a number of physiological functions and behaviors through specific seven transmembrane domains receptors. We report here the first full‐length cloning and functional characterization of a melatonin receptor (P2.6) in a fish, the pike (Teleost). P2.6 encodes a protein that is ˜80% identical to melatonin receptors previously isolated partially in non‐mammals and classified as members of the Mel1b subtype; but, it shares only 61% identity with the full‐length human Mel1b melatonin receptor (hMT2). Expression of P2.6 results in ligand binding characteristics similar to that described for endogenous melatonin receptors. Selective antagonists of the hMT2 (4‐phenyl‐2‐propionamidotetraline and luzindole) were poor competitors of 2‐[125I]iodomelatonin binding to the recombinant receptor. In Chinese hamster ovary cells expressing both the cystic fibrosis transmembrane conductance regulator chloride channel and P2.6 receptor, melatonin counteracted the forskolin induced activation of the channel. The results are best explained by a selective inhibition of the adenylyl cyclase. By reverse transcription‐polymerase chain reaction, P2.6 mRNA appeared expressed in the optic tectum and, to lesser extent, in the retina and pituitary. In conclusion, these results, together with those of a phylogenetic analysis, suggest that P2.6 might belong to a distinct subtype group within the vertebrate melatonin receptor family.