bluuebunny/crossref_metadata_2025_split huggingface dataset:
High incidence of autoantibodies in Taiwanese patients with oral submucous fibrosis
Authors: Chiang C. P. , Hsieh R. P. , Chen T. H. H. , Chang Y. F. , Liu B. Y. , Wang J. T. , Sun A. , Kuo M. Y. P. 
Published: March 2003

AbstractBackground:  Previous study has shown a high incidence of autoantibodies including antinuclear (ANA), antismooth muscle (SMA), antigastric parietal cell (GPCA), antithyroid microsomal (TMA), and antireticulin antibodies in a small group of 26 patients with oral submucous fibrosis (OSF). The reasons why some of the OSF patients have high titers of autoantibodies in serum have not been completely explained and no further study on autoantibodies in OSF patients has been done in a large group of patients.Methods:  In this study, we determined the serum levels of ANA, SMA, GPCA, and TMA in a large group of 109 male Taiwanese patients with OSF by an indirect immunofluorescence technique (for ANA, SMA, and GPCA), and by a semiquantitative microtiter particle agglutination test (for TMA). The presence of serum autoantibodies in OSF patients was further correlated with patients' oral habits and the severity of OSF measured by maximum mouth opening (MMO) and sites of involvement.Results:  We found that the frequencies of presence of serum ANA (23.9%), SMA (23.9%), and GPCA (14.7%) in OSF patients were significantly higher than those (9.2, 7.3, and 5.5%, respectively) in healthy control subjects (P < 0.01, P < 0.005, and P < 0.05, respectively). Although the frequency of presence of TMA (5.5%) in OSF patients was also greater than that (2.8%) in healthy control subjects, the difference was not significant (P > 0.05). The presence of serum GPCA in OSF patients was significantly associated with daily areca quid (AQ) consumption (P < 0.05). The presence of serum ANA in OSF patients associated with daily AQ consumption was of borderline statistical significance (P = 0.066). However, no significant correlations were demonstrated between the presence of serum autoantibodies in OSF patients and other variables of oral habits, MMO, and sites of involvement.Conclusion:  In this study, all the 109 OSF patients had AQ chewing habit and 73.4% of the OSF patients swallowed the ‘juice’ of AQ during the chewing process. The presence of serum GPCA and ANA in OSF patients was associated with daily consumption of AQs. AQ chewing caused mucosal microtrauma, and ulcerations facilitated the diffusion of genotoxic and cytotoxic AQ ingredients into the oral and gastric tissues. Altered autoantigens released from AQ ingredients‐damaged cells may induce autoantibody production. Higher frequencies of specific HLA‐DR antigens in OSF patients may also help autoantibody production. Therefore, we conclude that the high incidence of autoantibodies in OSF patients may be due to AQ chewing habit, toxic AQ ingredients, and genetic susceptibility of the OSF patients.
Odontogenic cyst with verrucous proliferation
Authors: Aldred Michael J , Talacko Anna A , Allan Peter G , Shear Mervyn 
Published: March 2003

AbstractAn unusual case of an odontogenic cyst with verrucous proliferation is described in a 13‐year‐old girl. This histologically distinctive odontogenic cyst variant does not appear to have been reported previously. The cyst was characterised by a series of verrucous projections in the lumen with hypergranulosis and cells resembling koilocytes, raising the possibility of a viral aetiology. However, no evidence of human papillomavirus (HPV) was found using immunohistochemistry and polymerase chain reaction (PCR) amplification.
Metastatic infiltration of the dental pulp by medulloblastoma
Authors: Ahmad S. , Roberts G. J. , Lucas V. S. , Barrett A. W. , Harkness W. 
Published: March 2003

AbstractMedulloblastoma is an infratentorial primitive neuroectodermal tumour. It is the most commonly occurring brain tumour of childhood, accounting for 15–20% of all paediatric tumours. Extracranial metastasis is rare, but may involve the skeleton. Jaw lesions, however, have never been described. A case is reported of metastases of a medulloblastoma to the jaw including the dental pulp.
Epidemiology of necrotizing ulcerative gingival lesions in adolescents
Authors: Lopez R , Fernandez O , Jara G , Aelum V. B 
Published: March 2003

Objective and background:   Relatively little is known about the epidemiology of necrotizing ulcerative gingival lesions (NUG) in adolescent populations. Most studies have comprised special target groups, such as military recruits, HIV patients, or severely malnourished subjects.Methods:  A multistage random cluster sampling scheme was used to obtain a sample of 9203 students aged 12–21 years from 98 of a total of 618 high schools in Santiago, Chile. Students were given a clinical oral examination and questionnaire information was obtained on smoking and oral hygiene habits, dental attendance patterns, and diabetic status. The diagnostic criteria for NUG were the presence of necrosis and ulceration of at least one interproximal papillae.Results:  The estimated prevalence of NUG was 6.7% (95% CI = [6.2; 7.3]). A multivariable logistic regression analysis showed that last seeing a dentist more than 1 year ago (OR = 1.60), or never (OR = 1.93), and reporting diabetes (OR = 2.12) showed a significant positive association with the presence of NUG; whereas neither gender nor smoking were important predictors. Students aged 18‐21 years were more, albeit statistically insignificantly, likely to have NUG than were younger students (OR = 1.40).Conclusions:  Our observation that reporting to be diabetic was positively associated with the presence of NUG is interesting, as diabetes has never been addressed as a possible risk factor. As the association between diabetes and periodontitis in adults is thought to relate to impaired function of neutrophils, microangiopathy, and impaired wound healing this finding suggests a significant role of the host response also for the occurrence of NUG.
Cytolethal distending toxin of Actinobacillus actinomycetemcomitans
Authors: Tan Kai Soo , Song Keang‐Peng , Ong Grace 
Published: March 2003

The cytolethal distending toxin (Cdt) of Actinobacillus actinomycetemcomitans, a periodontal pathogen, is a newly described cytotoxin with immunosuppressive properties, capable of causing cell cycle arrest of lymphocytes. The objectives of this study were to investigate the occurrence of A. actinomycetemcomitans with the cdt genotype in the subgingival plaque of periodontitis patients and to determine the association of this bacterial genotype with periodontal disease.A total of 146 subgingival plaque samples from periodontitis patients were assayed by the PCR method using oligonucleotide primers targeting the cdt operon of A. actinomycetemcomitans. Primers targeting the leukotoxin gene A (ltxA) of A. actinomycetemcomitans was used to determine the occurrence of the bacteria in the plaque samples at baseline.At baseline, A. actinomycetemcomitans was detected in 106 out of 146 (73%) diseased sites studied. Among the 106 diseased sites found to harbor A. actinomycetemcomitans, 13 sites were positive for the bacteria with the cdt genotype (12%). Out of the 13 positive sites, 10 sites were obtained from patients diagnosed with aggressive periodontitis (77%).Thus, A. actinomycetemcomitans with the cdt genetic subtype has low occurrence in the subgingival plaque of periodontitis patients. However, a strong association was observed between the presence of the bacteria and aggressive forms of periodontitis. Thus, the cytotoxic and immunosuppressive properties of A. actinomycetemcomitans Cdt may function to cripple the host immunity and contribute to the pathogenesis of aggressive periodontitis.
Transmission of UVA radiation through epithelium of oral mucosa and skin in rat and man
Authors: Kuusilehto Asko 
Published: March 2003

Background/Methods: Transmission of 362 nm ultraviolet A radiation (UVA) through epithelium of oral mucosa and skin epidermis was compared in rat and man. The transmitted irradiance was measured by means of a radiometer.Results: In man, significantly (P<0.01) greater transmittance (2.8‐fold) was observed in skin compared to buccal mucosa. In rat, no significant differences were found.Conclusion: In different species and different types of epitheliae, separate studies are needed for the evaluation of UVA transmission.
Is vascular reactivity in skin predictable?
Authors: Lindén Maria , Andersson Thomas , Wårdell Karin , Anderson Chris 
Published: March 2003

Background/aims: Cutaneous microdialysis can be used to follow the pharmacology and metabolism of an inflammatory reaction. It is assumed that an equilibration period compensates for the trauma of catheter insertion.Methods: In the present paper, the vascular reactivity of the skin to histamine was tested using assessment by laser Doppler perfusion imaging. In a group of six subjects, the provocation was preceded by insertion of a microdialysis catheter. In a second control group, histamine provocation alone was performed (six subjects).Results: The vascular response to histamine was greater in the microdialysis catheter group than the control group. The histamine provocation caused a greater response than catheter insertion. Further, there was a correlation between the response to catheter insertion and the histamine provocation.Conclusion: It appears that the insertion and/or presence of a microdialysis catheter increases vascular reactivity to subsequent provocation. The response to catheter insertion may predict skin reactivity in general in the individual subject.
Optical analysis of displacement and strain fields on human skin
Authors: Marcellier H. , Vescovo P. , Varchon D. , Vacher P. , Humbert P. 
Published: March 2003

Background/aims: The aim of this article is to propose a new way to measure the mechanical behaviour of skin by using optical analysis software. Some examples on scars and stretch marks show the validity and the prospects of such a method.Methods: Software is used to compare two states of deformation. The user takes two photos of the skin surface he wants to study, before and after the deformation is applied. The software is used to process the data.Results: The software gives a mapping of the displacement, and strain fields of the area studied. Investigations can be realised in vitro or in vivo, and it is possible to study, for example, cutaneous lesions like scars and stretch marks.Conclusions: The method presented gives convincing results, which open many prospects in dermatology, surgery and cosmetology.
Age‐dependent response of energy metabolism of human skin to UVA exposure: anin vivostudy by31P nuclear magnetic resonance spectroscopy
Authors: Declercq Lieve , Perin Fabrice , Vial Francis , Savard Sébastien , Petitcollin Bénédicte , Beau Patrick , Collins Don , Mammone Tom , Maes Daniel 
Published: March 2003

PurposeThe aim of our study was to evaluate thein vivoenergy metabolism of human skin as a function of age, in conditions of rest and after a mild stress caused by a suberythemal UVA irradiation.MethodsThe kinetics of UVA‐induced modifications in high‐energy phosphorylated metabolites of young and old skins were non‐invasively monitored over a period of 24 h using31P nuclear magnetic resonance spectroscopy.In vivo31P spectra were obtained on the ventral aspect of the wrist, using a NMR Imaging Spectrometer equipped with a double‐tuned surface coil. Concentrations of phosphocreatine, inorganic phospate, adenosine tri‐phosphate, phosphomono and phosphodiesters were calculated from the spectra and results were expressed as relative concentrations. A total of 20 subjects were enrolled in this study (n = 10 for the age group below 25 years andn = 10 for the age group above 55 years). A second experiment was then performed on 10 old subjects (mean age 60) who were treated on one wrist, twice a day for one month prior to UVA irradiation, with a product that contained active ingredients to restore barrier function and modulate the inflammatory response, the other wrist being an untreated control.ResultsBaseline levels of phosphorylated metabolites were similar in young and old skins. A suberythemal dose of UVA (6 J.cm−2) led to a significant decrease in the PCr/Pi ratio (index of energy status) and a significant increase in the PME/PDE ratio (index of cellular turnover rate of lipid‐related metabolites) within 1 h. The observed variations were transient and the recovery was complete at T + 24 h post‐UVA, although recovery was significantly slower in the older group. The disturbances were significantly reduced after treatment of the older skin with a formula that restored barrier function of the stratum corneum and modulated the inflammatory response.Conclusion(i) baseline levels of energy metabolites in skin do not seem to vary with age; (ii) low dose UVA irradiation induces a rapid response in the energy metabolism of the skin; (iii) the kinetics of the response and recovery after an aggression by UVA suggest that older skin has significantly less energy rebound after a stress situation than younger skin; (iv) the energy reserve in older skin can be protected efficiently against UVA‐induced stress by restoring barrier function and modulating the inflammatory response.
Empirical evidence of a convection–diffusion model for pH patterns in the rhizospheres of root tips
Authors: Nichol S. A. , Silk W. K. 
Published: March 2003

AbstractA recently formulated convection–diffusion model predicted that root growth plus diffusion of protons in the neighbouring soil would lead to particular pH patterns around the moving root tip. To test the predictions of this theory, pH was measured at differing radial distances from the root surface after 24 h of growth in a medium with low diffusivity (sandy soil) and after a shorter period (55 min of growth) in a medium with high diffusivity (agar). In agreement with the theory, the growth zone was found to influence the pH of the soil for distances less than 1 mm from the root surface (even after many hours) and the pH of the agar for a distance of at least 5 mm (after only 1 h). The axial pattern of pH along the surface of soil‐grownZea maysL. root tips was found to be the same for roots growing at different rates under different temperatures (2·23 mm h−1at 26 °C or 1·27 mm h−1at 20 °C). Thus, the plant can synchronize proton flux with growth to maintain a particular surface pH pattern within the growth zone. This implies that root tips growing at different rates in response to different temperatures can carry the same microenvironment of pH through a homogeneous soil.
Spatial distribution of leaf water‐use efficiency and carbon isotope discrimination within an isolated tree crown
Authors: Le Roux X. , Bariac T. , Sinoquet H. , Genty B. , Piel C. , Mariotti A. , Girardin C. , Richard P. 
Published: March 2003

AbstractThe spatial variations in the stable carbon isotope composition (δ13C) of air and leaves (total matter and soluble sugars) were quantified within the crown of a well‐watered, 20‐year‐old walnut tree growing in a low‐density orchard. The observed leaf carbon isotope discrimination (Δ) was compared with that computed by a three‐dimensional model simulating the intracanopy distribution of irradiance, transpiration and photosynthesis (previously parameterized and tested for the same tree canopy) coupled to a biophysically based model of carbon isotope discrimination. The importance of discrimination associated with CO2 gradients encountered from the substomatal sites to the carboxylation sites was evaluated. We also assessed by simulation the effect of current irradiance on leaf gas exchange and the effect of long‐term acclimation of photosynthetic capacity and stomatal and internal conductances to light regime on intracanopy gradients in Δ. The main conclusions of this study are: (i) leaf Δ can exhibit important variations (5 and 8‰ in total leaf material and soluble sugars, respectively) along light gradients within the foliage of an isolated tree; (ii) internal conductance must be taken into account to adequately predict leaf Δ, and (iii) the spatial variations in Δ and water‐use efficiency resulted from the short‐term response of leaf gas exchange to variations in local irradiance and, to a much lesser extent, from the long‐term acclimation of leaf characteristics to the local light regime.
Comparative physiology of salt and water stress
Authors: Munns R. 
Published: March 2003

AbstractPlant responses to salt and water stress have much in common. Salinity reduces the ability of plants to take up water, and this quickly causes reductions in growth rate, along with a suite of metabolic changes identical to those caused by water stress. The initial reduction in shoot growth is probably due to hormonal signals generated by the roots. There may be salt‐specific effects that later have an impact on growth; if excessive amounts of salt enter the plant, salt will eventually rise to toxic levels in the older transpiring leaves, causing premature senescence, and reduce the photosynthetic leaf area of the plant to a level that cannot sustain growth. These effects take time to develop. Salt‐tolerant plants differ from salt‐sensitive ones in having a low rate of Na+and Cl–transport to leaves, and the ability to compartmentalize these ions in vacuoles to prevent their build‐up in cytoplasm or cell walls and thus avoid salt toxicity. In order to understand the processes that give rise to tolerance of salt, as distinct from tolerance of osmotic stress, and to identify genes that control the transport of salt across membranes, it is important to avoid treatments that induce cell plasmolysis, and to design experiments that distinguish between tolerance of salt and tolerance of water stress.
Differential genetic variation in adaptive strategies to a common environmental signal in Arabidopsis accessions: phytochrome‐mediated shade avoidance
Authors: Botto J. F. , Smith H. 
Published: March 2003

AbstractShade avoidance is a syndrome of plastic responses to light signals encountered in crowded plant communities and is a crucial component of competitive strategy in higher plants. The responses are mediated via signal perception by specific members of the phytochrome family of photoreceptors, which detect the relative proportions of red (R) and far‐red (FR) radiation within dense communities. We analysed two aspects of shade avoidance, the acceleration of flowering and the enhancement of elongation growth, displayed by more than 100 accessions of Arabidopsis thaliana (Heyn.) in response to FR‐proximity signals. Both traits showed wide variation between accessions, which was unrelated to the latitude of the location of original collection. Flowering acceleration is a major feature of shade avoidance in rosette plants such as Arabidopsis, and most accessions showed dramatic responses, but several were identified as being recalcitrant to the proximity signal. These accessions are likely to be informative in the analysis of quantitative variation in shade avoidance. Hypocotyl elongation, treated here as an indicator of elongation growth responses, also varied widely amongst accessions. The variations in flowering acceleration and elongation were not correlated, indicating that microevolution in the downstream pathways from signal perception has occurred separately.
Several lanthanides activate malate efflux from roots of aluminium‐tolerant wheat
Authors: Kataoka T. , Stekelenburg A. , Nakanishi T. M. , Delhaize E. , Ryan P. R. 
Published: March 2003

AbstractMany elements of the lanthanide series exist as trivalent cations in solution below pH 6. The present study was carried out to investigate whether lanthanides could stimulate malate efflux from wheat (Triticum aestivum L.) roots, as has been found for trivalent aluminium (Al) cations. Excised root apices treated with 100 µm of each of seven different lanthanide elements (lanthanum, praseodymium, europium, gadolinium, terbium, erbium, and ytterbium) stimulated malate efflux, with five‐ to fifty‐fold more malate being released from an Al‐tolerant wheat line than from a near‐isogenic Al‐sensitive line. As erbium stimulated the greatest malate efflux of the lanthanides tested, this response was characterized further. The characteristics of the erbium‐activated efflux were similar to the Al‐activated efflux described previously suggesting that both of these ions activate the same transport mechanism. The capacity for erbium‐activated malate efflux cosegregated with Al tolerance in wheat seedlings derived from a cross between Al‐sensitive and Al‐tolerant near‐isogenic lines. This is the first study to identify cations, other than Al, which can activate malate release from wheat roots. It also provides additional evidence that malate efflux from root apices is the primary mechanism for Al tolerance in wheat.
Preferential production of interferon‐γ by CD4+ T cells expressing the homing receptor integrin α4/β7
Authors: Abramson Oren , Qiu Shiqiang , Erle David J. 
Published: March 2003

SummaryRecent studies indicate that T helper type 1 (Th1) and 2 (Th2) lymphocytes differ in their expression of molecules that control T‐cell migration, including adhesion molecules and chemokine receptors. We investigated the relationship between cytokine production and expression of the homing receptor integrin α4/β7 on T cells. We began by analysing cytokine production by human CD4+ CD45RA– memory/effector T cells following brief (4 hr) stimulation with phorbol 12‐myristate 13‐acetate (PMA) and ionomycin. α4/ CD4+ T cells were more likely to produce the Th1 cytokine interferon‐γ (IFN‐γ) than were α4/β7− CD4+ T cells in all six subjects studied. In contrast, production of the Th2 cytokine interleukin‐4 (IL‐4) was similar on α4/ and α4/β7− CD4+ T cells. In addition, we found that human CD4+ CD45RA– T cells that adhered to the α4/β7 ligand mucosal addressin cell adhesion molecule‐1 (MAdCAM‐1) had a greater capacity to produce IFN‐γ than did non‐adherent cells, suggesting that the association between α4/β7 expression and IFN‐γ production has functional significance. These results suggested that primary activation under Th1‐promoting conditions might favour expression of α4/β7. We directly examined this possibility, and found that naïve murine CD4+ T cells activated under Th1‐promoting conditions expressed higher levels of α4/β7 compared to cells activated under Th2‐promoting conditions. The association between α4/β7 expression and IFN‐γ production by CD4+ T cells may help to determine the cytokine balance when MAdCAM‐1 is expressed at sites of inflammation in the intestine or elsewhere.