bluuebunny/crossref_metadata_2025_split huggingface dataset:
C and N mineralisation in the decomposer food webs of a European forest transect
Authors: Schröter Dagmar , Wolters Volkmar , De Ruiter Peter C. 
Published: July 2003

Belowground processes are essential for the overall carbon and nitrogen fluxes in forests. Neither the functioning of the soil food web mediating these fluxes, nor its modulation by environmental factors is sufficiently understood. In this study the belowground carbon and nitrogen mineralisation of four European coniferous forest sites (northern Sweden to north‐east France) with different climate and N depositional inputs was analysed by investigating the soil food webs using field observations and modelling. The soil fauna directly contributed 7–13% to C mineralisation, among which the testate amoebae (Protozoa) made the largest contribution. Microbial grazing was suggested to have an important indirect effect by stimulating bacterial turnover. Due to relatively high C:N ratios of their substrate, bacteria immobilized N, while the fauna i.e. testate amoebae, nematodes, microarthropods and enchytraeids, counteracted this N immobilisation.Despite similar food web biomass, the sites differed with respect to food web structure and C and N flows. Model calculations suggested a significant influence of food web structure on soil ecosystem processes in addition to environmental factors and resource quality. Mineralisation rates were lowest at the low N input boreal site with a food web dominated by fungal pathways. Further south, as N availability increased, bacterial pathways became more important and the cycling of C and N was faster. The bioavailability of degradable C sources is suggested to be a limiting factor for microbial activity and overall mineralisation rates. In this respect, above‐ and belowground interactions e.g. transfers of labile C sources from the vegetation to the decomposer system deserve further attention.Our study revealed the combined effects of climate and nutrient inputs to ecosystems and the subsequent changes in the structure and functioning of the systems. If decomposition, and therefore carbon loss, is stimulated as a consequence of structural and/or nutritional changes, resulting for example from continuous industrial N emission, the storage capacity of forest ecosystems could be altered.
Do non‐additive effects on decomposition in litter‐mix experiments result from differences in resource quality between litters?
Authors: Smith Victoria C. , Bradford Mark A. 
Published: July 2003

Differences in resource quality between litter species have been postulated to explain why litter‐mixtures may decompose at a different rate to that which would be predicted from single species litters (termed ‘non‐additive effects’). In particular, positive, non‐additive effects of litter‐mixing on decomposition have been explained by differences in initial nitrogen concentration between litter species. This interpretation is confounded because litter species that differ in nitrogen content also differ by a number of other resource quality attributes. Thus, to investigate whether initial nitrogen concentration does account for positive, non‐additive effects of litter‐mixing, we mixed grass litters that differed in initial nitrogen concentration but not species or structural plant part identity, and then followed mass loss from the litter‐mixes over time. We used the litterbag technique and three grass species for which a gradient of four distinct initial nitrogen concentrations had been generated. We produced all no‐ to four‐mix compositions of litter qualities for each species. Litter from different species was never mixed.Contrary to what would be predicted, we found that when litters of the same species but with different initial nitrogen concentrations were mixed, that negative, non‐additive effects on decomposition were generally observed. In addition, we found that once mixed, increasing litter quality richness from two to four mixtures had no significant, non‐additive effect on decomposition. Litter quality composition explained little of the experimental variation when compared to litter quality richness, and different compositions generally behaved in the same manner. Our findings challenge the commonly held assumption that differences in nitrogen concentration between plant species are responsible for positive, non‐additive effects of litter‐mixing on decomposition.
Morphology dependent foraging efficiency in perch: a trade‐off for ecological specialization?
Authors: Svanbäck Richard , Eklöv Peter 
Published: July 2003

Trade‐offs in foraging efficiency leading to divergent natural selection between and within populations exploiting different resources are thought to be a primary cause of trophic polymorphism. In this study we focused on the trade‐offs in foraging efficiency and growth in a polymorphic perch population. Specifically, we related habitat‐specific growth and diet of perch to perch morphology. In a subsequent laboratory study we experimentally tested the trade‐off by testing the efficiency of perch with different morphology feeding on pelagic (Daphnia sp., Chaoborus sp.) and littoral (mayfly larvae) food resources. The feeding performance was tested in different physical environments to see if we could predict growth patterns in the field based on foraging rate and behavior of perch.In the field study, we found that the perch from the littoral and the pelagic zones differed in both morphology and diet. Within the littoral zone the deeper‐bodied individuals grew faster compared to the more streamlined individuals, whereas the opposite pattern was found in the pelagic zone. In the aquarium experiments, perch from the littoral zone had higher capture rates on the pelagic prey types in vegetation trials and on mayfly larvae in both open water and vegetation trials. The pelagic perch had higher capture rates on the pelagic prey types in open water trials. The littoral perch had lower search velocity than the pelagic perch in open water trials whereas the opposite pattern was found in vegetation trials. The attack velocity of the pelagic perch was also higher than that of the littoral perch independent of vegetation structure. Our results suggest that there is a functional trade‐off between performance in alternate habitats and general body form in perch. Such trade‐offs may promote divergent natural selection and could be the mechanism that give rise to and upholds the pattern in the field.
Histopathological analysis and demonstration of EBV and HIV p‐24 antigen but not CMV expression in labial minor salivary glands of HIV patients affected by diffuse infiltrative lymphocytosis syndrome
Authors: Rivera Helen , Nikitakis Nikolaos G. , Castillo Sleygh , Siavash Hessam , Papadimitriou John C. , Sauk John J. 
Published: July 2003

AbstractBackground:  The diffuse infiltrative lymphocytosis syndrome (DILS) in HIV patients is characterized by the persistence of CD8‐circulating lymphocytes and lymphocytic infiltration, predominantly in salivary glands.Methods:  We examined seven HIV‐positive patients with bilateral parotid enlargement and sicca symptoms. Minor labial salivary gland biopsies were performed in all patients and submitted for histopathological analysis and immunohistochemistry for CD4, CD8, cytomegalovirus (CMV), LMP–EBV protein, and HIV p‐24 protein.Results:  In all cases, lymphocytic infiltration of the minor salivary glands, mainly periductal, was found. Acinar atrophy, ductal ectasia, and mild to moderate fibrosis were also observed. We noticed strong immunohistochemical reaction for LMP–EBV and p‐24 proteins in ductal cells in all cases, while staining for CMV was consistently negative. The lymphocytes were positive for CD8, but consistently negative for CD4.Conclusions:  A role of Epstein–Barr virus (EBV) and HIV, but not CMV, in the pathogenesis of DILS, is suggested by our immunohistochemical findings.
Construction of large area organotypical cultures of oral mucosa and skin
Authors: Igarashi M. , Irwin C. R. , Locke M. , Mackenzie I. C. 
Published: July 2003

AbstractBackground:  Skin and oral mucosal keratinocytes grown in vitro usually lose their normal patterns of differentiation, unless grown as organotypical cultures that are constructed by allowing collagen gels containing fibroblasts to contract before they are plated with keratinocytes and raised to the air/medium interface. However, the contraction process tends to produce small irregular cultures.Methods:  To generate uniformly differentiating large cultures, we have investigated several aspects of the factors involved in the culture construction. By adjusting the number of fibroblasts used and by plating the matrices with keratinocytes prior to contraction, cultures of up to 72 cm2 were constructed.Results:  The cultures retained almost the full surface areas of the original matrices and showed uniform patterns of epithelial plating and differentiation. Immunostaining for cytokeratins and integrins indicated restoration of in vitro phenotypes similar to those of the epithelial tissues of origin.Conclusions:  These methods successfully generate cultures required for certain types of investigations and tissues that are suitable for clinical use as grafts.
Synergistic enhancement of collagenous protein synthesis by human gingival fibroblasts exposed to nifedipine and TNF‐alpha in vitro
Authors: Johnson Roger B. 
Published: July 2003

AbstractBackground:  Gingival overgrowth occurs in patients receiving nifedipine. Gingival inflammation may be an etiologic factor.Methods:  Gingival fibroblasts were either exposed to (i) 0–500 ng/ml TNF‐alpha or 10−7 m nifedipine or (ii) 0–500 ng/ml TNF‐alpha + 10−7 m nifedipine for 7 days. 3H‐proline was used to quantify collagenous protein synthesis.Results:  Both TNF‐alpha and 10−7 m nifedipine significantly decreased cell proliferation, and 10−7 m nifedipine + 500 ng/ml TNF‐alpha reversed these effects. Collagenous protein synthesis was significantly reduced by TNF‐alpha and was significantly enhanced by either 10−7 m nifedipine or 5–500 ng/ml TNF‐alpha + 10−7 m nifedipine.Conclusions:  Our data report that nifedipine reverses the primary effects of TNF‐alpha on collagenous protein synthesis. Patients with gingivitis could be susceptible to gingival overgrowth during nifedipine therapy as a result of synergistic effects of these agents on fibroblast metabolism, which occurs irrespective of reduced cell numbers.
Comparative study of HPV prevalence in Japanese and North‐east Chinese oral carcinoma
Authors: Tang Xiaofei , Jia Lin , Ouyang Jie , Takagi Minoru 
Published: July 2003

AbstractBackground:  Human papillomavirus (HPV) plays a role in the development of oral carcinoma. However, the reported prevalence of HPV in oral carcinoma has varied widely.Methods:  The prevalence of HPV 16, 18 and 33 was investigated in Japanese and North‐east Chinese oral squamous cell carcinomas (OSCCs) with polymerase chain reaction (PCR). The expression of p53 protein was examined immunohistochemically.Results:  HPV 16 and 18 were detected in 7 (23.3%) and 10 (33.3%) of 30 Japanese and 11 (36.7%) and 5 (16.7%) of 30 Chinese samples, respectively. HPV 16 and 18 coinfection was detected in 3/30 Japanese and 2/30 Chinese samples. HPV 33 was not detected. There was no significant correlation between HPV 16 and 18 and the sites, gender, age and histological grade. The prevalence of both HPV 16 and 18 was similar and higher in the Japanese and North‐east Chinese samples (46.7% each). HPV 16 or/and 18 infection or/and p53 overexpression were in 22 (73.3%) of 30 Japanese samples and 24 (80.0%) of 30 North‐east Chinese samples, respectively.Conclusions:  HPV 16/18 infection or/and p53 overexpression may play an important role in developing some OSCCs. and the presence of HPV sequences and mutant p53 are not necessarily mutually exclusive.
Modulation of KGF‐1 gene expression in oral fibroblasts by ripe areca nut extract
Authors: Ko Shun‐Yao , Lin Shu‐Chun , Chang Kuo‐Wei , Liu Chung‐Ji , Chang Shu‐Shin , Lu Suu‐Yi , Liu Tsung‐Yun 
Published: July 2003

AbstractBackground:  Areca chewing is a common habit of Asians, leading to a high propensity for a variety of oral diseases in this population. This research aimed to study the expression level of genes in oral fibroblast cell lines in response to exposure to ripe areca nut extract (rANE).Methods:  Fifteen oral fibroblast cell lines obtained from individuals aged 20–77 years were established. Treatment of a cell line with 40 µg/ml rANE for 24 h was performed to achieve RNA for cDNA microarray analysis.Results:  Among some 320 genes exhibiting detectable expression levels, 14 were up‐regulated and 26 were down‐regulated more than 2.5‐fold. Semi‐quantitative RT‐PCR analysis suggested that up‐regulation of IL‐6 expression and down‐regulation of PDGFR, APP‐1 and KGF‐1 expressions in multiple cell lines assayed, were compatible with the results of the microarray analysis. Using quantitative real‐time RT‐PCR analysis, a remarkable down‐regulation of KGF‐1 expression in response to 40 µg/ml rANE, ranging 1.5–ninefold as compared to controls, was found in 60% (9/15) of the cell lines.Conclusion:  This study established a novel toxicogenomic database for rANE. The down‐regulation of KGF‐1 expression in oral fibroblast cell lines potentially impairs the proliferation of overlying keratinocytes, which could partially explain the frequent epithelial atrophy observed in chronic areca chewers in vivo.
Synovial osteochondromatosis accompanying an ossified articular disk in the temporomandibular joint: a case report
Authors: Shibuya Tomoaki , Kino Koji , Kitamura Yuri , Takahashi Testu 
Published: July 2003

AbstractA 51‐year‐old woman was referred for pain in the right temporomandibular joint (TMJ) and the trismus. Conventional radiography showed a radiopaque area in the disk, which suggested calcification. At surgery, multiple, round‐to‐ovoid cartilagenous nodules were found in the joint cavity. Synovectomy and diskectomy were carried out via a pre‐auricular incision to remove the nodules. Examination under light microscopy confirmed the diagnosis of synovial osteochondromatosis (SOC). The disk contained a large ossified mass. To our knowledge, this is the first reported example of SOC accompanied by ossification of a large part of the disk.
Proliferative verrucous leukoplakia: high incidence of gingival squamous cell carcinoma
Authors: Bagan Jose V. , Jimenez Yolanda , Sanchis Jose M. , Poveda Rafael , Milian Mari A. , Murillo Judith , Scully Crispian 
Published: July 2003

AbstractBackground:  Proliferative verrucous leukoplakia (PVL) is a multifocal and progressive lesion of the oral mucosa, often associated with papillomavirus, seen mainly in older females, and characterized by a high recurrence rate and high rate of transformation into verrucous or oral squamous cell carcinoma (OSCC). The aim of this study was to analyse the clinical characteristics of a substantial group of patients with PVL, evaluating the characteristics of those who developed cancer, and comparing them with a group of patients with OSCC but no preceding PVL.Methods:  A group of 30 patients with PVL was studied for the clinical aspects and characteristics, age, sex, location, recurrence, the appearance of new lesions, and the frequency of development of oral cancer. A disease control group was formed with 110 patients with OSCC chosen randomly from among those treated in the same Service in this period of time. The patients were grouped as PVL and no cancer (Group 1); PVL developing cancer (Group 2) and patients with OSCC without clinical lesions associated with PVL (Group 3).Results:  The average age of the PVL patients (Groups 1 and 2 combined) was 70.97 ± 12.73 years, of which 80% were women. Only 23.3% were cigarette smokers. The area most frequently affected with PVL was the lower gingiva. Recurrence after treatment was seen in 86.7%, and new lesions appeared in 83.3%. Many (63.3%) developed cancer (Group 2). Comparison of Groups 2 and 3 patients showed that those with PVL developing cancer were more likely to develop gingival carcinoma and also to be older, more often females, and less likely to smoke tobacco.Conclusion:  Cancer developing in patients with PVL manifested particularly on the gingiva.
Aggressive, multifocal oral verrucous leukoplakia: proliferative verrucous leukoplakia or not?
Authors: Ghazali Naseem , Bakri Marina Mohd , Zain Rosnah Binti 
Published: July 2003

AbstractBackground:  Some oral verrucal lesions may constitute parts of the clinicopathological spectrum of proliferative verrucous leukoplakia (PVL). Because of its idiopathic yet sinister nature, it is possible that PVL may exist in other populations. The aim of this study was to review the clinicopathological features of persistent, multifocal, oral verrucal lesions in Malaysian population.Methods:  Patients with multifocal oral verrucal lesions were selected from surgical and histopathological records.Results:  Nine patients of diverse ethnicity with 43 biopsies were reviewed. The mean age at the presentation was 62 years. The most frequent sites affected were gum, sulci, cheek and tongue. Indulgence in risk habits was reported in about 70% of patients. Four cases developed multifocal carcinoma from multifocal leukoplakia.Conclusions:  In retrospect, none of the cases fulfilled the original PVL criteria, although three cases were suggestive of PVL. Nevertheless, these findings do not necessarily preclude the existence of PVL as a clinicopathological entity in Malaysian population.
Distribution and toxicity resulting from adenoviral vector administration to a single salivary gland in adult rats
Authors: O'Connell Brian C. , Zheng Changyu , Jacobson‐Kram David , Baum Bruce J. 
Published: July 2003

AbstractBackground:  We examined the distribution and toxicity associated with a single salivary gland administration of a recombinant adenoviral vector, AdCMVH3, encoding human histatin 3.Methods:  Adult rats received different doses of AdCMVH3 (0, 106, 3 × 107, and 109 pfu; 50 µl) via the right submandibular gland and were followed for 15 days. Food consumption, weight gain, clinical appearance, and serum chemistry were monitored, and a necropsy was performed. Vector distribution was examined by polymerase chain reaction, and selected saliva samples were tested for replication‐competent adenovirus (RCA).Results:  All animals survived to sacrifice (days 2, 8, and 15), and appeared normal clinically. There were no differences in food consumption, weight gain, and serum chemistry. The only consistent necropsy findings were lymphoid infiltrates and necrosis in the target submandibular glands of high‐dosage animals. AdCMVH3 detection was virus dose dependent, decreased with time, and at low dose preferentially observed in the targeted gland. No RCA was detected.Conclusions:  Salivary gland administration of 109 pfu AdCMVH3 elicits an initial focal pathologic response and wide tissue distribution. There is no associated systemic toxicity up to 15 days, and lower doses are primarily found in glands.
Wegener's granulomatosis presenting with otologic and neurologic symptoms: clinical and pathological correlations
Authors: Bucolo Sebastiano , Torre Valerio , Montemagno Alberto , Beatrice Fabio 
Published: July 2003

AbstractA case of Wegener's granulomatosis in a 59‐year‐old woman is reported. The disease first involved the parotid gland, the brain stem and the spinal cord, then running a rapidly progressive course as systemic pathology. Anti‐neutrophil cytoplasmic antibody (cANCA) levels raised as renal failure set in. Renal biopsy confirmed the diagnosis of Wegener's granulomatosis and an appropriate therapy was adopted.
Comparison between Cytokine Concentration in Follicular Fluid of Poor and High Responder Patients and their Influence of ICSI‐outcome
Authors: Hammadeh M. E. , Fischer‐Hammadeh C. , Georg T. , Rosenbaum P. , Schmidt W. 
Published: July 2003

OBJECTIVE: The aim of this study was to compare the cytokine concentration in follicular fluid (FF) of low and high responder intracytoplasmic sperm injection (ICSI) patients and to find out the impact of these cytokines in FF on ICSI outcome.DESIGN: The levels of insulin‐like growth factor (IGF)‐I, IL‐6, IL‐8, epidermal growth factor (EGF), platelet‐derived growth factor (PDGF), granulocyte‐macrophage‐colony stimulating factor (GM‐CSF) were measured from low and high responder ICSI patients, the results were compared between the two groups and their influence on ICSI outcome was analysed.MATERIAL AND METHODS: A total of 49 low (G.I) and 34 high (G.II) responder patients were enrolled in this study. FF was collected at the time of oocyte retrieval and measured either by enzyme‐linked immunosorbent assay (IL‐6, IL8, EGF, PDGF, GM‐CSF) or radio immuno assay (IGF‐I).RESULTS: The concentration of IL‐6 (pg/mL), IL‐8 (pg/mL), IGF‐I (ng/mL), PDGF (pg/mL), EGF (pg/mL), GM‐CSF (pg/mL) in G.I was 6.0 ± 4.3, 288.1 ± 139.2, 0.416 ± 0.089, 249.8 ± 150.1, 9.12 ± 5.5 and 1.45 ± 2.10 and the corresponding value in G.II was 7.4 ± 4.8, 208.6 ± 64.0, 0.431 ± 0.094, 387.6 ± 36.0, 8.9 ± 5.4 and 1.8 ± 3.3, respectively. Only the PDGF concentration showed a significant (P = 0.007) difference between the two groups. Besides, negative correlations were found between PDGF and fertilization rate (r = −0.287; P = 0.046) of G.I. The mean number of retrieved (6.4 ± 2.3 versus. 15.7 ± 5.4) and fertilized (3.6 ± 1.6 versus 7.0 ± 4.5) oocytes differ significantly (P = 0.001) between the two groups. The fertilization rate was significantly higher in G.I than in G.II (60.9 ± 25.1 versus 43.4 ± 20.7%).CONCLUSION: There was no significant difference between IGF‐I, IL‐6, IL‐8, EGF and GM‐CSF concentrations of low and high responder patients. Besides, PDGF was significantly (P = 0.007) higher in high responder compared with low responder patients. Moreover, in poor responder patients, a negative correlation was found between PDGF and fertilization rate. However, the cytokine levels in FF of the patients undergoing controlled ovarian hyperstimulation for ICSI could not be used as a marker of oocyte fertilization and implantation potential.
Analyses of Dendritic Cell Subsets in Pregnancy
Authors: Yoshimura T. , Inaba M. , Sugiura K. , Nakajima T. , Ito T. , Nakamura K. , Kanzaki H. , Ikehara S. 
Published: July 2003

PROBLEM: Changes in the frequency of dendritic cell (DC) subsets in the peripheral blood were analyzed as pregnancy progressed, and the effects of human chorionic gonadotropin (hCG) on myeloid and lymphoid DC subsets were phenotypically and functionally examined.METHOD OF STUDY: Two major subsets of DCs were prepared from the peripheral blood by flowcytometry. Major histocompatibility complex class II molecules and adhesion/costimulatory molecules were examined before and after culture with hCG. hCG receptors on both DC subsets were analyzed by reverse transcriptase‐polymerase chain reaction (RT‐PCR).RESULTS: The frequency of myeloid DCs increased in the late stage of pregnancy, while that of lymphoid DCs gradually decreased. The addition of hCG (physiological concentrations in pregnancy) to cultures induced the maturation of both DC subsets in conjunction with increases in the expression of adhesion/costimulatory molecules, their stimulatory activities in allogeneic mixed lymphocyte/leukocyte reaction, and cytokine secretion (interleukin‐12 and interferon‐γ). hCG receptors were found in both DC subsets by RT‐PCR, suggesting that these stimulatory activities of hCG are mediated by hCG receptors on the DCs.CONCLUSIONS: hCG can modulate immune responses through the activation of myeloid and lymphoid DCs.