bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical evidence for hepatic progenitor cells in liver diseases
Authors: Tan Jianyou , Hytiroglou Prodromos , Wieczorek Rosemary , Park Young NyuN. , Thung Swan N. , Arias Byron , Theise Neil D. 
Published: March 2003

Abstract:  Background/Aim: Proliferative bile ductular reactions occur in a variety of liver diseases in humans. It is a matter of debate whether such reactions result from progenitor cell proliferation with biliary and hepatocytic differentiation, versus biliary metaplasia of damaged hepatocytes. We investigated bile ductular reactions in liver diseases, paying particular attention to the presence of cells with intermediate (hepatocytic/biliary) features (oval‐like cells).Methods: Five specimens each were selected of submassive hepatic necrosis and cirrhosis due to hepatitis B, hepatitis C, autoimmune hepatitis, alcohol injury, primary biliary cirrhosis and primary sclerosing cholangitis. Immunohistochemical stains were performed for biliary markers (cytokeratins [CKs] 7 and 19), as well as hepatocytic markers (HepParl and alpha‐fetoprotein[AFP]) in sequential sections. The degree of staining of each cell type (biliary, hepatocytic, intermediate) was graded semiquantitatively.Results: Hepatocytes always stained diffusely for HepParl, occasionally for CK7, and rarely for CK19. Biliary cells were always diffusely positive for CK7 and CK19, and rarely for HepParl. Intermediate cells were identified in all cases and showed widespread staining for both HepParl and CK7, and less commonly for CK19. AFP was not expressed in any cell type. The morphologic and immunohistochemical features of bile ductular reactions were similar in the different diseases.Conclusions: Proliferating hepatic parenchymal cells with intermediate (hepatocytic/biliary) morphologic features and combined immunophenotype can be identified in a variety of acute and chronic liver diseases. The similarity of bile ductular reactions among chronic hepatitic, alcoholic and biliary diseases suggests that they result from proliferation of oval‐like progenitor cells.
Spontaneous ovarian tumors in twelve baboons: a review of ovarian neoplasms in non‐human primates
Authors: Moore Charleen M. , Hubbard Gene B. , Leland M.Michelle , Dunn Betty G. , Best Robert G. 
Published: March 2003

Abstract: Twelve spontaneous ovarian tumors were found in the Southwest Foundation for Biomedical Research baboon colony. These included four granulosa cell tumors, three teratomas, two endometrioid carcinomas, one seromucinous cystadenofibroma, a cystic papillary adenocarcinoma, and an ovarian carcinoma. Age was a pre‐disposing factor. With one exception, the tumors of surface epithelial‐ and sex cord‐stromal origin occurred in baboons over 17 years of age. The exceptional animal was 7 years of age when a malignant granulosa cell tumor with Sertoli cell differentiation was identified. The two endometrioid tumors, which were found in 17‐ and 30‐year‐old animals, were both associated with endometriosis. In contrast, the teratomas, which are tumors of germ cell origin, were found in younger animals, i.e. 17 years of age or younger. One case of an ovarian carcinoma with metastases was observed in a 6‐month‐old infant. Cases of spontaneous ovarian tumors from the literature are reviewed.
Interspecific and intraspecific interactions between salt marsh plants: integrating the effects of environmental factors and density on plant performance
Authors: Huckle Jonathan M. , Marrs Rob H. , Potter Jacqueline A. 
Published: March 2003

There has been much debate about the role of plant interactions in the structure and function of vegetation communities. Here the results of a pot experiment with controlled environments are described where three environmental variables (nutrients, sediment type and waterlogging) were manipulated factorially to identify their effects on the growth and intensity of interactions occurring between Spartina anglica and Puccinellia maritima. The two species were grown in split‐plot planting treatments, representing intraspecific and interspecific addition series experiments, to determine individual and interactive effects of environmental factors and plant interactions on plant biomass.

Above‐ground growth of both species involved interactions between the environmental and planting treatments, while below‐ground, environmental factors affected the biomass irrespective of planting treatments. It was suggested that this difference in growth response is evidence that in our experiment plant interactions between the two species occur primarily at the above‐ground level.

The intensity of plant interactions varied in a number of ways. First, interactions between Spartina and Puccinellia were distinctly asymmetrical, Puccinellia exerting a competitive effect on Spartina, with no reciprocal effect, and with a facilitative effect of Spartina on Puccinellia in low nutrient conditions. Second, the interactions varied in intensity in different environmental conditions. Interspecific competitive effects of Puccinellia on Spartina were more intense in conditions favourable to growth of Puccinellia and reduced or non‐existent in environments with more abiotic stress. Third, intraspecific competition was found to be less intense for both species than interspecific interactions. Finally, the intensity of plant interactions involving both species was more intense above ground than below ground, with a disproportionate reduction in the intensity of interspecific competition below relative to above ground in treatments with less productive sediments and greater immersion. This is interpreted as reflecting a potential mechanism by which Spartina may be able to evade competitive neighbours.
Size‐dependent competitive ability in a deposit‐feeding amphipod, Monoporeia affinis
Authors: Aljetlawi Albashir A. , Leonardsson Kjell 
Published: March 2003

We investigated the competitive ability in terms of maintenance resource density, C0, in relation to body size, of a deposit feeder Monoporeia affinis (Lindström) (Amphipoda). Growth curves were obtained from nine‐day single size‐class experiments with several food densities, consisting of fresh phytoplankton. The functional response and the size‐dependence of attack rate (clearance rate) and handling time were estimated using a dynamic growth model including ingestion and energetic costs. The energetic costs were obtained from treatments without food. C0 was solved from the growth model by setting growth to zero. The best description of growth was found using a Holling type II functional response. The attack rate was independent of M. affinis body size, while handling time decreased, and C0 increased with body size.

To investigate the occurrence of intercohort interference and its influence on C0, we used the parameter estimates to predict the growth in mixed size‐classes experiments. These experiments were similar to the single size‐class experiments except for the addition of two size‐classes of M. affinis. The observed growth was lower than predicted for all size‐classes. Incorporation of an interference term to the functional response in the growth model improved its fit to the observed data. This indicated that both interference and exploitation competition occurred. The interference increased C0 for the smallest sizes, and reduced its size‐dependence. C0 increased most for the largest individuals, but most likely for reasons other than interference. According to predictions by Persson et al. (1998) concerning population dynamic properties, our results indicate that the unstable dynamics commonly found for this species are due to higher competitive ability of juveniles rather than of maturing sub‐adults.
From inducible defences to population dynamics: modelling refuge use and life history changes in Daphnia
Authors: Vos Matthijs , Flik Ben J. G. , Vijverberg Jacobus , Ringelberg Joop , Mooij Wolf M. 
Published: March 2003

We investigated the relative importance of a behavioural defence (refuge use through diel vertical migration) and a life history change (a reduced size at first reproduction) that are used by daphnids to decrease the risk of predation by visually hunting fish. We used an individual based model of a Daphnia population in a stratified lake to quantify the effects of these inducible defences on Daphnia predation‐mortality and the resulting Daphnia population dynamics. Our analysis shows that diel vertical migration (DVM) confers a much stronger protection against fish predation than a reduced size at first reproduction (SFR). DVM allows daphnids to withstand a higher predation pressure in the epilimnion and it decelerates a Daphnia population decline more strongly than a reduced SFR. DVM effectively reduces the (P/B) flow of carbon from daphnids to fish.

Many theoretical studies have only considered the fitness benefits of DVM above ‘staying up’ in the epilimnion of a lake. Our results suggest that ‘staying down’ in the hypolimnion would confer an even stronger fitness benefit to Daphnia than DVM at times of peak predation risk. Daphnids that remain in the hypolimnion avoid the predation suffered by migrating daphnids around dusk and dawn. Staying down could prevent a Daphnia population decline, while DVM and a reduced SFR can only decelerate the decrease of Daphnia population densities under heavy fish predation. Staying down at high concentrations of fish infochemicals has in fact been observed within a variety of Daphnia clones and species, both in the laboratory and in stratified lakes.
The up‐regulation of cyclooxygenase‐2 expression in human buccal mucosal fibroblasts by arecoline: a possible role in the pathogenesis of oral submucous fibrosis
Authors: Tsai Chung‐Hung , Chou Ming‐Yung , Chang Yu‐Chao 
Published: March 2003

AbstractBackground:  Aberrant and persistent tissue inflammation are believed to play an important role on the occurrence of tissue fibrosis. Cyclooxygenase (COX)‐2 is an inducible enzyme responsible for prostaglandin synthesis in certain inflammatory diseases. The purpose of this study was to compare COX‐2 expression in normal human buccal mucosa and oral submucous fibrosis (OSF) specimens and further explore the potential mechanism that may lead to induce COX‐2 expression.Methods:  Fifteen OSF specimens and six normal buccal mucosa were examined by immunohistochemistry. Primary human buccal mucosa fibroblasts (BMFs) were established and challenged with arecoline analyzed by reverse transcriptase polymerase chain reaction. Furthermore, to elucidate whether induction of COX‐2 is associated with cytotoxicity, aspirin (a non‐selective inhibitor of COX enzyme) and NS‐398 (a selective COX‐2 inhibitor), were added to test their protective effects.Results:  COX‐2 expression was significantly higher in OSF specimens and expressed mainly by epithelial cells, endothelial cells, and cells with fibroblast morphology. In vitro studies indicated that BMFs did not express COX‐2 constitutively. However, when the cells were treated with 80 µg/ml arecoline, COX‐2 expression was up‐regulated as early as half an hour. This indicates that COX‐2 expression is an early cellular response and regulated by arecoline at transcriptional level. In addition, pre‐treatment with glutathione (GSH) precursor, 2‐oxothiazolidine‐4‐carboxylic acid (OTZ), led to a decrease in induction of COX‐2 mRNA by arecoline. GSH synthesis inhibitor, buthionine sulfoximine (BSO), was found to increase arecoline‐induced COX‐2 mRNA levels. Moreover, both of aspirin and NS‐398 at non‐cytotoxic doses are not able to prevent arecoline‐induced cytotoxicity. This indicates that arecoline cytotoxicity is not directly via the induction of COX‐2 expression.Conclusions:  Taken together, these results suggest that COX‐2 expression is significantly up‐regulated in OSF tissues from areca quid chewers and arecoline may among other constituents be responsible for the enhanced COX‐2 expression in vivo. The regulation of COX‐2 expression induced by arecoline is critically dependent on the cellular GSH concentration.
Candida‐induced stomatopyrosis and its relation to diabetes mellitus
Authors: Vitkov Ljubomir , Weitgasser Raimund , Hannig Matthias , Fuchs Karl , Krautgartner Wolf Dietrich 
Published: March 2003

AbstractBackground:  Glycaemic disorders and oral candidosis can be accompanied by burning mouth sensations. However, no clear relation between all three disorders is known.Methods:  Seventy‐two native Upper‐Austrians with burning mouth sensations were examined and smears for Candida estimation were taken from the spots where the sensations were felt. All patients with previously unknown diabetes mellitus (DM) were subjected to an oral glucose tolerance test (OGTT). Use of glucocorticoid‐containing anti‐asthmatic sprays and the body mass index (BMI) were determined.Results:  Of the examined non‐inhalers of sprays, 52% had increased candidal density. A correlation between that increase and type 2 DM was found. The burning sensations in all patients with increased candidal density subsided completely after anti‐mycotic therapy.Conclusion:  The perception of burning sensations was hypothesised to occur via stimulation of the capsaicin (vanilloid) receptor by Candida metabolites. The Candida‐induced stomatopyrosis should be regarded as a single symptom indicating (predisposition to or established) type 2 DM in non‐inhalers of the concerned population.
Th1 cytokines in oral lichen planus
Authors: Khan Ambereen , Farah Camile S. , Savage Neil W. , Walsh Laurence J. , Harbrow Doug J. , Sugerman Philip B. 
Published: March 2003

AbstractBackground:  Cell‐mediated immune responses in oral lichen planus (OLP) may be regulated by cytokines and their receptors.Methods:  In situ cytokine expression and in vitro cytokine secretion in OLP were determined by immunohistochemistry and ELISA.Results:  The majority of subepithelial and intraepithelial mononuclear cells in OLP were CD8+. In some cases, intraepithelial CD8+ cells were adjacent to degenerating keratinocytes. CD4+ cells were observed mainly in the deep lamina propria with occasional CD4+ cells close to basal keratinocytes. Mononuclear cells expressed IFN‐γ in the superficial lamina propria and TNF‐α adjacent to basal keratinocytes. Basal keratinocytes expressed TNF‐α as a continuous band. TNF R1 was expressed by mononuclear cells and basal and suprabasal keratinocytes. There was variable expression of TGF‐β1 in the subepithelial infiltrate while all intraepithelial mononuclear cells were TGF‐β1−. Keratinocytes in OLP stained weakly for TGF‐β1. Unstimulated OLP lesional T cells secreted IFN‐γin vitro. TNF‐α stimulation down‐regulated IFN‐γ secretion and up‐regulated TNF‐α secretion. IL‐4, IL‐10 and TGF‐β1 secretion were not detected.Conclusions:  These data suggest the development of a T helper 1 immune response that may promote CD8+ cytotoxic T‐cell activity in OLP.
Alterations of nitrate and nitrite content in saliva, serum, and urine in patients with salivary dysfunction
Authors: Xia Dengsheng , Deng Dajun , Wang Songlin 
Published: March 2003

AbstractBackground:  The role of the salivary glands in the maintenance of nitrate and nitrite in saliva is poorly understood. The aim was to study alterations of nitrate and nitrite metabolisms in patients with Sjogren's syndrome (SS) or sialosis.Methods:  Saliva, serum, and urine samples were collected from healthy volunteers (n = 29), patients with SS (n = 31), and patients with sialosis (n = 30). Concentrations of nitrate and nitrite were determined by high‐performance liquid chromatography (HPLC).Results:  In the healthy group, the highest concentration of nitrate was found in parotid saliva (172 mg/l), followed by urine (160 mg/l), whole saliva (97 mg/l), and serum (33 mg/l). In the SS group, concentration of nitrate was decreased in parotid saliva and whole saliva, and increased significantly in urine. Concentration of nitrite in whole saliva was significantly decreased in the SS group and increased in the sialosis group.Conclusion:  Hypofunction of the salivary glands is associated with significant changes of nitrate and nitrite levels in the saliva and urine.
Lichtenberg's Paraclete Fragments
Authors: Katritzky Linde 
Published: March 2003

Lichtenberg conceived his Paraclete satire originally against the excessive exuberance of the Sturm und Drang, but gradually his focus shifted, and the work never materialized. As the disconnected, surviving fragments give only vague impressions of his intentions, they have attracted little attention, and have been mostly dismissed as negligible and lacking in merit. Yet the complexities of Lichtenberg's vision emerge when his scattered sketches are integrated with related remarks in his voluminous notes. Then the enigmatic hints, allusions and incomplete memoranda appear as integral parts of the consistent attitude which Lichtenberg invariably directed towards practical applications in everyday life.The title, Paraclete, is taken as key to his design. Greek for advocate, comforter, intercessor, it is a synonym for the Holy Ghost, translated by Luther as Spirit of Truth. Lichtenberg secularized this term to convey the ideals of the Enlightenment, against which he gauged the inadequate reality and the intellectual failings and abuses that aroused his disapproval and apprehension. Thus, while his targets changed, this focus remained steady. Interpreted in light of the title, these fragments demonstrate Lichtenberg's consuming concern about the misuse of human potential through disregard of the spirit of the Enlightenment and truth.
Evaluation of the inhibitory activity of topical indomethacin, betamethasone valerate and emollients on UVL‐induced inflammation by means of non‐invasive measurements of the skin elasticity
Authors: Dobrev Hristo 
Published: March 2003

Background/Aim: Topical indomethacin has been reported to inhibit ultraviolet light‐induced erythema. The objective of this study was to verify this assertion and to compare indomethacin 10% ointment to betamethasone valerate 0.1% ointment, water‐in‐oil emulsion and oil‐in‐water emulsion by means of non‐invasive skin elasticity measurements.Methods: Products were applied on the back skin 60 min and 5 min before and 5 min after UVL irradiation. Untreated test sites served as controls. Clinical evaluation, measurements of epidermal hydration (Corneometer) and mechanical properties of the skin (Cutometer) were made 1 h before and 24 h after exposure.Results: Test areas treated with indomethacin 60 min and 5 min before irradiation showed the significantly lowest visual erythema scores and no significant changes in skin mechanical parameters. At all other test sites, a significant decrease in elasticity parameters (Ue, Ur, Ua/Uf, Ur/Uf) and an increase in viscoelasticity parameters (Uv, Uv/Ue) of the skin were observed. No significant changes of epidermal hydration were found at any of the test sites.Conclusion: The inhibitory action of topical indomethacin on UVL‐induced inflammation is superior to betamethasone valerate and emollients. Non‐invasive measurement of skin elasticity could be used as a supplementary tool for objective evaluation and comparison of the photoprotective activity of different topical agents.
Sunscreen use and melanoma:a case of evidence‐based prevention?
Authors: Gefeller O. , Pfahlberg A. 
Published: March 2003

Background:
A preventive effect of sunscreens on melanoma development is still subject of intense discussion. The practical consequences for changes in public health campaigns are neglected in this debate.
Methods:
An extensive literature search for studies on the association between sunscreen use and melanoma occurrence was performed. The principles of evidence‐based medicine (EBM) are applied to the issue to derive at recommendations for an evidence‐based prevention of melanoma.Results: We identified 17 case‐control studies providing risk estimates for the relationship under study. These risk estimates are too heterogeneous to allow a reasonable conclusion by summarizing the evidence. The application of the EBM approach yields therefore an inconclusive result: the melanoma protective potential of sunscreens cannot be proven using the existing evidence. The information necessary to fully assess the effect of sunscreen use on melanoma development is not currently available.Conclusion: Based on the current evidence the focus of recommendations for melanoma prevention in public awareness campaigns has to be changed. It should be much more emphasized to minimize exposure to ultraviolet (UV) radiation during peak hours, wear protective clothing, hats and UV‐opaque sunglasses, seek shade and protect infants and children against too much UV radiation exposure at all than to use sunscreens.
UV‐induced skin changes due to regular use of commercial sunbeds
Authors: Ruegemer J. , Schuetz B. , Hermann K. , Hein R. , Ring J. , Abeck D. 
Published: March 2003

Background/aim: Increased pigmentation and thickening of the epidermis are the most important photoprotective skin reactions induced by ultraviolet (UV) radiation. The present study was designed to find out what changes are induced by regular use of commercial sunbeds twice weekly over a period of 6 weeks.
Methods:
The parameters analysed were skin pigmentation measured by chromametry, minimal erythema dose (MED) as a parameter of light sensitivity, epidermal thickening as determined by histology, induction of keratinocyte apoptosis as determined by TUNEL staining and antioxidant metabolism as measured by changes of cis‐ and trans‐urocanic acid (UCA) content of the skin.Results: As expected, chromametry confirmed the clinically obvious increased skin pigmentation. However, no increase in MED was observed. In addition, neither epidermal thickening nor sunburn cells were seen. Significant detectable changes in proportion of the UCA isomer content of the UV‐exposed skin were seen. The total UCA and cis‐UCA content increased significantly between nearly all points of measurement. The amount of trans‐UCA first decreased, then increased significantly between the different time points.Conclusion: Our data indicate that sunbed‐induced tanning is non‐protective, which has to be addressed for persons looking for this effect before planning a stay in a sunny climate. However, sunbed‐induced tanning may influence immunological reactions.
Myocardial ischemia–reperfusion in rats: reduction of infarct size by either supplemental physiological or pharmacological doses of melatonin
Authors: Sahna Engin , Acet Ahmet , Kaya Ozer M. , Olmez Ercument 
Published: March 2003

Abstract: Myocardial ischemia–reperfusion (I/R) represents a clinically relevant problem associated with thrombolysis, angioplasty and coronary bypass surgery. I/R injury is believed to be a consequence of free radical generation in the heart especially during the period of reperfusion. The pineal secretory product, melatonin, is known to be a potent free radical scavenger and pharmacological concentrations have been shown to reduce the I/R‐induced cardiac damage in isolated rat hearts. However, the physiological role of melatonin in the prevention of this damage is unknown. Rats were pinealectomized or sham‐operated (control) 2 months before the I/R studies. To produce cardiac damage, the left main coronary artery was occluded for 30 min, followed by 120 min reperfusion, in anesthetized rats. Infarct size, expressed as the percentage of the risk zone, was found significantly higher in pinealectomized rats (49±3.4%) than in the control group (34±3.6%). Melatonin administration (4 mg/kg, either before ischemia or reperfusion) to pinealectomized rats significantly reduced the infarct size values and returned them to the control values. On the other hand, melatonin administration (4 mg/kg) to sham‐operated rats failed to attenuate significantly the I/R‐induced infarct size. These results suggest that physiological melatonin concentrations are important in reducing the I/R‐induced myocyte damage, while pharmacological concentrations of melatonin did not add to the beneficial effect. As melatonin levels have been reported to decrease with age, melatonin replacement therapy may attenuate I/R‐induced myocardial injury, especially in older patients.