bluuebunny/crossref_metadata_2025 huggingface dataset:
Baseline and stress levels of cortisol in conscious and unrestrained Japanese macaques (Macaca fuscata)
Authors: Suzuki Juri , Ohkura Satoshi , Terao Keiji
Published: March 2003

Abstract: A vest and tethering system was applied to Japanese macaques (Macaca fuscata) to collect blood samples under less stressful conditions. The level of plasma cortisol was assayed to assess the amount of stress. The pattern of plasma cortisol fluctuation during 24 hours was consistent under non‐stress conditions. The plasma cortisol level was increased significantly by encounter and venipuncture. The increase was especially noteworthy when the experimental macaques encountered a large adult male, reflecting the strong stress on macaques. As venipuncture is a common medical procedure, and the encounter between macaques who have never met before occurs frequently, this vest and tethering system is useful for the assessment of the amount of stress in the daily care of macaques in a laboratory.
Preclinical AIDS vaccine research: survey of SIV, SHIV, and HIV challenge studies in vaccinated nonhuman primates
Authors: Warren Jon
Published: March 2003

Abstract: This current supplementary and systematic survey of 237 preclinical AIDS vaccine challenge/protection studies in nonhuman primates enumerates and broadly describes the recent status of different vaccine strategies in macaque and chimpanzee experimental models. Published studies since the previous survey were compiled and categorized by their vaccine types, challenge parameters, and challenge results. These models have supportively verified that some prophylactic vaccine approaches, though rarely preventing infection (which is observed in these models with some passively administered antibody‐based vaccines), can control to some degree primate lentivirus replication and disease development, and this is encouraging because it places more potentially effective immunogens on the precipice for early clinical studies. Many of these promising approaches may benefit from more testing in mucosal challenge models, and resources will be needed to follow more of these partially protected vaccinees for longer periods.
Fluid flow behaviour in a water model tundish under open, submerged and modified inlet conditions
Authors: Sinha S. K. , Godiwalla K. M. , Shaw D. K. , Sivaramakrishnan C. S.
Published: March 2003

A systematic study has been conducted on the fluid‐flow behaviour in in a two‐strand continuous casting model tundish under conditions of submerged entry nozzle (SEN) and open entry nozzle (OEN) with different levels of water in tundish. Flow has been characterised from the profiles of tracer responses at the tundish outlets. 2 configurations of entry nozzle, one the conventional straight tube (for SEN and OEN) and the other T‐shaped (for SEN only), were employed. Flow in the slag layer has been simulated by monitoring the tracer responses on the surface at 250, 500 and 750 mm away from the stream entry. It has been found that the lower the immersion depth of nozzle, the lower the inclusion level in the melt. Similarly a T‐shaped entry nozzle into the tundish also produces a cleaner melt and improves flow patterns in the vessel.
Modelling of alloy mixing into steel
Authors: Jauhiainen Anu , Jonsson Lage , Sheng Dong‐Yuan
Published: March 2003

Gas stirring of steel in the ladle is widely used in metallurgical industries to homogenise chemical composition and temperature, enhance reaction rates, etc. This study focused on the homogenisation, i.e., the mixing of alloy additions and steel during gas stirring. More specifically, the influence of porous plug location on alloy mixing into steel was studied theoretically. Flow fields were calculated and presented for simultaneous stirring with 2 porous plugs in 4 different arrangements. The alloy mixing into steel in the ladle with these different arrangements was studied with 2 different alloy addition methods. In the 1st method, the alloy was added in a batch at the beginning of the stirring. In the 2nd method, the alloy was added continuously throughout the stirring. When comparing the calculated results for the 4 different pairs of porous plug placements, it was found that centric stirring and centric addition rendered the best average mixing and also the least likelihood for “dead rooms” to develop. However, the combination of centric stirring and addition was found to be extremely sensitive to small variations in alloying position. It was therefore concluded that for steelmaking, the best of the studied alternatives is using 2 porous plugs placed such that their respective radii form an angle of 60°. Verification of calculated steel velocities was done with experimental data taken from a previous publication.
Thermodynamic study of spinel‐type solid solutions of the Fe3O4‐MgFe2O4 coexisting with Fe2O3 by emf method
Authors: Katayama Iwao , Iseda Atsuro
Published: March 2003

The emf of the following galvanic cell with ZrO2+ CaO solid electrolyte has been measured at temperatures between 1160 and 1390 K in the entire composition range of spinel‐type solid solutions of Fe3O4‐MgFe2O4 coexisting with Fe2O3.
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Thermodynamic functions are derived from the results. The activity of magnetite shows a positive deviation from Rauolt's law in the whole composition range. Activity and oxygen partial pressures in the spinel phase coexisting with Fe2O3 are compared with the published data. Integral Gibbs energy for the formation of (Fe3O4)x(MgFe2O4)1−x (M = Cu, Co, Zn, Ni and Mg) obtained by us with similar methods is listed.
Chemical wearing mechanism of refractory materials in a steel ladle slag line
Authors: Mattila R. A. , Vatanen J. P. , Härkki J. J.
Published: March 2003

Wearing of the ladle slag line is the biggest refractory material problem with ladles. The purpose of this work was to study the wearing mechanism of refractory materials in a steel ladle slag line. The studied refractory materials were MgO–C bricks, doloma brick, corundum castable and spinel castable. Rotating‐furnace and sessile‐drop tests were conducted with converter and ladle slags. The corrosion index, infiltration zone and refractory/slag mineralogical reactions were studied. The wear mechanisms of refractory materials were studied using SEM, XRF and XRD analysing techniques. The driving force behind chemical wearing is the chemical potential differences of the components between lining and slag. In general, the main principles of chemical wearing depend on the structure and mineralogical character of the refractory material.
Production of pure tungsten oxide from scheelite concentrates
Authors: Gürmen Sebahattin , Timur Servet , Arslan Cüneyt , Duman Ismail
Published: March 2003

Scheelite concentrates, obtained from Uludag, Bursa (Turkey), containing roughly 50% W, are treated by the chelate‐added acidic leaching route. Dissolved tungsten ions are then selectively precipitated by the addition of ‘ammonia ion‐containing’ reagents – either organic or inorganic – and thus are purified from other ions present in the solution. Selective precipitation of pure (> 99%) tungstate salt was realized from the polytungstate solution at 25°C by adding a ‘chelate‐breaking agent’ at a NH4+/WO3 weight ratio of ≥ 1/4. The formula of the complex salt is indicated by (NH4)3PW12O40·9H2O. The optimum precipitation conditions are investigated with the aim of making pure tungsten oxide via a thermal breakdown process. Tri‐ammonium‐dodeka‐tungstate‐phosphate salt can be easily converted to nanometer‐sized WO3 particles by a simple calcination operation carried out above 650°C. Weight loss ratios of the samples vary between 8.7 and 9.6% at the end of this 2‐h thermal breakdown process. Tungsten trioxide obtained can be suitably employed in tungsten‐related powder metallurgy applications with its extremely low impurity content of 0.04% Mo, 0.15% SiO2, 0.06% Fe and 0.03% Al.
A thermochemical study of the CaO + P2O5+ FexO system—regions in equilibrium with solid Ca3P2O8
Authors: Hasegawa M. , Iwase M. , Wakimoto K. , McLean A.
Published: March 2003

Electrochemical measurements involving stabilized zirconia as solid electrolyte and Mo + MoO2 as reference electrode were conducted in order to determine the activities of FexO for slags coexisting with solid Ca3P2O8 in the system CaO + P2O5+ FexO.
Female mating success and risk of pre‐reproductive death in a protandrous grasshopper
Authors: Del Castillo Raúl Cueva , Núñez‐Farfán Juan
Published: March 2003

Numerous studies have assessed the adaptive value of protandry for males in several insect species, considering that male emergence is determined by female availability. However, the possible advantage of the time of emergence for females on their mating success in protandrous insect species has only been explored theoretically. By studying the grasshopper Sphenarium purpurascens we evaluated the hypothesis that late emergence could be adaptive for females. If female maturation occurs when the population density is higher and the sex ratio (males/females) is biased to males, their probability of mating increases. Thus, in this study we estimated (1) the opportunity for mating in females as a function of their sexual maturation time, population density, and sex ratio at the moment they reached sexual maturity. In addition, (2) an analysis incorporating female body size and the total number of female matings was performed. Both analyses support the occurrence of protandry in the studied population. Under the first approach, females with intermediate maturation time had a higher probability of being mated than earlier and late matured females. Thus, it suggests that stabilising selection is acting on female maturation time and this may affect selection on male maturation time. Furthermore, the proportion of mated females increased when the sex ratio was biased to males, and stabilising selection on maturation time was detected also. However, the number of matings of a female depended on her body size. Females with larger body size had more matings than smaller ones at the beginning of the reproductive season. Because selection acts differently on maturation time in males and females of S. purpurascens this result is consistent with a condition for the maintenance of protandry in the population. The present results are discussed in the light of the models for the evolution of protandry.
The impact of ticks on pheasant territoriality
Authors: Hoodless Andrew N. , Kurtenbach Klaus , Nuttall Patricia A. , Randolph Sarah E.
Published: March 2003

Pheasants are competent reservoir hosts for the Lyme disease spirochaete,Borrelia burgdorferis.l., and carry large, but highly over‐dispersed, infestations of the vector ticks,Ixodes ricinus. The effects of experimental reduction of tick infestation levels on the survival and territorial behaviour of male pheasants were studied. Over three years in two woodlands in southern England, birds were marked individually and half were fitted with a slow‐release acaricide, which substantially reduced their tick burdens from March to August. Acaricide treatment affected reproductive success but had no discernible impact on the survival rates of male pheasants. The degree of wattle inflation by males, an indicator of territorial status and a correlate of harem acquisition, was significantly greater among treated males. In each year, a significantly higher proportion of treated (overall 44%) than control (22%) males acquired harems. Males that acquired females ranged over small areas on field edges. By contrast, those with no females ranged more widely in woods and the adjoining fields, increasing their exposure to questing ticks. The relative contribution of such roving males to tick‐borne pathogen transmission may thus increase.
Temporal variability of top‐down forces and their role in host choice evolution of phytophagous arthropods
Authors: Scheirs Jan , De Bruyn Luc
Published: March 2003

The role of top‐down forces in host choice evolution of phytophagous arthropods is the subject of a vividly animated debate. Empirical evidence for the evolutionary role of top‐down forces comes from studies showing that phytophagous arthropods prefer hosts that entail enemy‐free space. The aim of this paper is to draw the attention of plant–arthropod researchers to the potentially, temporally variable nature of third trophic level effects. We show that this aspect is largely neglected in studies on enemy‐free space, despite the fact that relative enemy impact varies seasonally among plants in at least some studies. We conclude that rigorous testing of the enemy‐free space hypothesis can only be performed when within and between season variation in higher trophic level effects is taken into account.
Mast fruiting and ENSO cycles – does the cue betray a cause?
Authors: Williamson G. Bruce , Ickes Kalan
Published: March 2003

Evidence is mounting that flowering by the mast‐fruiting Dipterocarpaceae in Southeast Asia is triggered by ENSO events such that seeds are dispersed at the end of ENSO droughts. These droughts induce substantial defoliation and mortality of canopy trees, producing a favorable environment for seedling recruitment in the forest understory. Therefore, seedling release following droughts may have selected for synchronized, supra‐annual fruiting in these rain forests. Currently, mast fruiting in Southeast Asia is generally regarded as an evolutionary response to seed predation by nomadic vertebrates. Separating the two causes for mast fruiting, seedling release and predator satiation, may be difficult if they are coupled in nature by ENSO droughts. Nevertheless, if the cue for masting is environmental, then the post‐ENSO seedling environment should be considered a potential cause for masting, and if it operates in conjunction with predator satiation, then it may have provided the initial stimulus for supra‐annual synchrony in fruiting.
Latitudinal trends in plant‐pollinator interactions: are tropical plants more specialised?
Authors: Ollerton Jeff , Cranmer Louise
Published: March 2003

The increase in richness of species and higher taxa going from higher to lower latitudes is one of the most studied global biogeographical patterns. Latitudinal trends in the interactions between species have, in contrast, hardly been studied at all, probably because recording interactions is much less straightforward than counting species. We have assembled two independent data sets which suggest that plant‐pollinator interactions are not more ecologically specialised in the tropics compared to temperate latitudes. This is in contrast to a prevailing view that tropical ecological interactions tend towards higher specificity than their temperate counterparts.
Can interaction coefficients be determined from census data? Testing two estimation methods with Negev Desert rodents
Authors: Shenbrot Georgy , Krasnov Boris
Published: March 2003

Two approaches based on regression models are proposed to estimate competition from census data. The “static” approach is based on censuses of population sizes among species at one point in time over many sites. The “dynamic” approach relies on a time series of species abundance data to examine whether per capita changes in one species are associated with the abundance of other species. We estimated competition interactions in a Negev rodent community consisting of 10 species using both approaches, basing on 8 years (16 half‐year periods) of observations. The static approach revealed significant competitive interactions in four of 45 pairs of species, whereas the dynamic approach did so in the same four plus two more pairs. For each species pair, both approaches revealed significant negative interactions in only 1–4 of 16 seasons. The static approach provided nearly symmetric estimations of competition, whereas estimations of dynamic approach were asymmetric. Moreover, estimations of the two approaches did not coincide in time. Cases of negative interactions recorded by the static approach were more frequent at peak and increase phases of population density dynamics, whereas those recorded by the dynamic approach were more frequent at peak and decline phases. Results of field removal experiments with Mus musculus and Gerbillus dasyurus supported predictions of dynamic but not static approaches. We hypothesized that in harsh and fluctuating desert environments that disrupt equilibrium, the dynamic approach indicates true (exploitation) competition, whereas the static approach reflects negative interspecific spatial association (interference).
Odour‐mediated nectar foraging in the silver Y moth,Autographa gamma(Lepidoptera: Noctuidae): behavioural and electrophysiological responses to floral volatiles
Authors: Plepys Dainius , Ibarra Fernando , Francke Wittko , Löfstedt Christer
Published: March 2003

Naive male and female silver Y moths,Autographa gamma(Lepidoptera: Noctuidae), were attracted in a flight tunnel assay to potted creeping thistle,Cirsium arvense(Asteraceae), butterfly‐orchid,Platanthera bifolia(Orchidaceae), soapwort,Saponaria officinalis(Caryophyllaceae), greater knapweed,Centaurea scabiosa(Asteraceae), red clover,Trifolium pratense(Fabaceae), and catnip,Nepeta faasseni(Labiatae), plants with flowers. The most attractive plants wereC. arvense,P. bifoliaandS. officinalisthat elicited 87, 78 and 65% source contacts, respectively.C. scabiosawas less attractive eliciting 43% response.T. pratenseandN. faassenishowed the least attraction eliciting 28 and 26% source contacts, respectively. A cotton plant used as control, was not attractive. Floral volatiles from the investigated plant species were collected using headspace sampling technique. Samples were analysed using gas chromatography coupled with electroantennographic detection, and electrophysiologically active compounds were identified by coupled gas chromatography/mass spectrometry. Consistent electrophysiological responses were elicited by twelve compounds from headspace ofC. arvense, thirteen compounds fromP. bifolia, eleven compounds fromS. officinalis, nine fromC. scabiosa, ten fromT. pratenseand two fromN. faasseni. Most of the active compounds were specific for one or two species, while benzyl benzoate was present in four and benzaldehyde and benzyl alcohol in three species. Floral scents ofC. arvense,P. bifoliaandS. officinalis, the most attractive flowers, were dominated by aromatic compounds that were not abundant in the scent of other flowers. To conclude, the results demonstrate the absence of a common denominator of odours present in flowers of different plants visited byA. gamma.
Immunolocalization of tumor necrosis factor‐α expressing cells in recurrent aphthous ulcer lesions (RAU)
Authors: Natah Sirajedin S. , Häyrinen‐Immonen Ritva , Hietanen Jarkko , Malmström Maria , Konttinen Yrjö T.
Published: March 2003

Abstract: Tumor necrosis factor (TNF)‐α is a pro‐inflammatory cytokine and crucial mediator in many aspects of immunity. Although several studies have shown that recurrent aphthous ulcers (RAU) can be prevented by treatment that prevents the synthesis of endogenous TNF‐α, little is known about the location and distribution of TNF‐α‐expressing cells at disease sites. The aim of the present work is, therefore, to investigate TNF‐α and its cellular distribution in RAU lesions compared with those in induced oral traumatic ulcers (TUs). Twelve biopsies of RAU lesions of oral mucosa were obtained from 12 patients with RAU. They were compared to a control group consisting of ten samples of induced TUs. All samples were analyzed for TNF‐α expression by using monoclonal mouse anti‐human TNF‐α antibody in avidin‐biotin‐peroxidase complex (ABC) staining. Results were quantified by a semi‐automatic VIDAS image analysis system. TNF‐α immunoreactivity was contained mainly in monocyte/macrophages and lymphocytes within the mononuclear inflammatory infiltrates. TNF‐α was often seen in mast cells and vascular endothelial cells in connective tissue lateral to the inflammatory infiltrates. Interestingly, 32%–60% of the mononuclear cells were found to be TNF‐α immunoreactive in RAU lesions. TNF‐α‐containing cells were more numerous in aphthae (188±46 cells/0.2 mm2) compared with controls (52±14 cells/0.2 mm2, P<0.001). These findings suggest that RAU lesions are characterized by high expression of TNF‐α. Because such expression occurred in the mononuclear inflammatory cells, mast cells and vascular endothelial cells, TNF‐α, which is a major inflammatory mediator, may contribute to the activation and recruitment of leukocytes that are found in RAU lesions.
Comparative study of oral squamous cell carcinoma in Okinawa, Southern Japan and Sapporo in Hokkaido, Northern Japan; with special reference to human papillomavirus and Epstein‐Barr virus infection
Authors: Tsuhako K. , Nakazato I. , Miyagi J. , Iwamasa T. , Arasaki A. , Hiratsuka H. , Sunakawa H. , Kohama G. , Abo T.
Published: March 2003

Abstract: In Okinawa, a subtropical island in Southern Japan, the incidence of oral squamous cell carcinoma is 1.5 times higher than that in mainland Japan. Sixty cases of oral squamous cell carcinoma from 1993 to 1996 in Okinawa and 42 cases over the same period in Sapporo were examined histologically. Human papillomavirus (HPV) and Epstein‐Barr virus (EBV) were detected by polymerase chain reaction (PCR) amplification with primers specific for HPV and EBV. In situ hybridisations of the viruses were also carried out. In the case of Epstein‐Barr virus, in situ PCR was also performed. Thirty‐five (58.3%) Okinawan tumours were well‐differentiated in type, but in Sapporo, 18 (42%) were of such type. In Okinawa, tumours of the mouth floor (10 cases, 16.7%) and oropharynx (12 cases, 20%) were frequently observed, whereas in Sapporo only five cases (12%) of each were found. HPV was demonstrated in 78% of Okinawan cases and 26.2% of Sapporon cases by PCR or non‐isotopic in situ hybridisation (NISH). There were 76.6% (46 cases) of Okinawan and 38.1% (16 cases) of Sapporo cases positive for EBV by PCR. In only 12 Okinawan cases and 4 Sapporon cases, were positive signals demonstrated by in situ PCR on the cancer cells themselves. EBV was demonstrated in the large number of infiltrating lymphocytes, most of which were CD3+, and a few were CD19+. In Okinawa, HPV might be an important causative factor of oral squamous cell carcinoma and EBV a less important factor, whereas in Sapporo HPV and EBV might play only a small part in the aetiology of the tumour.
Prognostic and predictive factors in oral cancer: the role of the invasive tumour front
Authors: Bànkfalvi A. , Piffkò J.
Published: March 2003

Abstract: Most decisions for cancer patients are now made on the basis of prognostic and predictive factors. However, due to the limited prognostic value of conventional tumour/nodal/metastasis staging and histopathological grading in oral cancer, a large group of patients are still over‐ or under‐treated with significant personal and socioeconomical impact. Recent work indicates that morphological and functional characteristics of the invasive tumour front underlie the biological aggressiveness of oral cancer. Incorporation of these concepts into a prognostic system will better reflect the biologic diversity of oral cancer and more accurately predict clinical outcomes and responses to particular types of adjuvant therapy.
The p53 molecule and its prognostic role in squamous cell carcinomas of the head and neck
Authors: Nylander Karin , Dabelsteen Erik , Hall Peter A.
Published: March 2003

Abstract: Despite intense research, the 5‐year survival rate for patients with squamous cell carcinoma of the head and neck (SCCHN) is still low. Several different factors have been studied in the search for one or more factors that give important prognostic information at the time of diagnosis. Many recent studies have focused on the TP53 tumour suppressor gene, analysing its gene status and protein status. When looking at p53 protein expression, using immunohistochemistry, no correlation to patient outcome has been seen for the whole group of SCCHN. However, a significant association between p53 expression and poor patient outcome was found when looking only at patients with laryngeal squamous cell carcinomas. Also, in oral premalignant lesions, expression of p53‐positive cells in the suprabasal layers of the epithelium has been seen as an indication of impending malignant development. Concerning the prognostic significance of mutations in the TP53 gene, results differ. But when restricting analysis to tumours with mutations causing an obvious change in protein, TP53 mutation was found to be a strong and independent variable for prognosticating survival. This review article gives an up‐to‐date overview of the p53 molecule and evaluates its possible prognostic role in SCCHN. Today it is clear that the p53 pathway is very important in SCCHN biology and potentially in its treatment. The function and importance of a few other cell cycle proteins connected to p53 are also discussed.
Variation in the response to ductal obstruction of feline submandibular and sublingual salivary glands and the importance of the innervation
Authors: Harrison J. D. , Fouad H. M. A. , Garrett J. R.
Published: March 2003

Abstract: A variable response following ductal ligation of feline salivary glands corresponds to the human condition but contrasts with a predictable atrophy in obstructed salivary glands of rodents popularly used as a model for human salivary problems. The present investigation is concerned with a possible reason for the variable response, namely the preservation of the innervation. Ducts of feline submandibular and sublingual salivary glands were ligated with or without the inclusion of the chorda tympani. Inclusion led to a delayed initial response followed by progressive atrophy until the parenchyma was extremely atrophic, whereas avoidance of the chorda led to the variable response in which variable numbers of acini of a similar form to normal persisted. The results establish the atrophic effect of inclusion of the chorda tympani in ductal ligation and indicate the caution that should be exercised in the extrapolation of the rodent model to the human condition.
Expression of matrix metalloproteinase‐2 and ‐9 in synovial fluid of the temporomandibular joint accompanied by anterior disc displacement
Authors: Tanaka Akira , Kumagai Shigehiro , Kawashiri Shuichi , Takatsuka Shigeyuki , Nakagawa Kiyomasa , Yamamoto Etsuhide , Matsumoto Nario
Published: March 2003

Abstract: The purpose of this study was to determine whether or not matrix metalloproteinases (MMPs) in synovial fluid are helpful in the biochemical diagnosis of temporomandibular joint (TMJ) disorder (TMD). We examined the synovial fluid from 38 TMD patients with disc displacement and 20 volunteers by gelatin zymography and immunoblotting analysis to clarify the involvement of the joint pathology from the viewpoint of expression of MMPs. Two gelatinolytic enzymes, MMP‐2 and ‐9, were detected in the samples. The incidences of expression, except for pro‐MMP‐2, in anterior disc displacement (ADD) without reduction (ADD w/o R) were significantly higher than in ADD with reduction (ADD w R) (P<0.05). Quantitative analysis showed that the degree of MMP‐2 and ‐9 expression in ADD w/o R were higher than in ADD w R. These data suggest that the presence or absence of disc reduction is a major turning point in the process of joint destruction, and these MMPs are useful as biochemical markers for TMD diagnosis.
Immunohistochemical study during healing of free palatal mucosa grafts on plastic‐embedded samples
Authors: Lauer G. , Wiedmann‐Al‐Ahmad M. , Otten J. E. , Hübner U.
Published: March 2003

Abstract: This immunohistochemical study describes changes in the histology and in the distribution of the basement membrane components laminin and collagen IV as well as of the cytokeratins (CK)1/2/10/11, CK5/6, CK13, CK14, CK17, CK19 during the take of free split mucosa (epithelial and connective tissue) transplants in humans up to 36 months post‐operative. Histology showed a flattening of the epithelial layer within the first 2 weeks after grafting, followed initially by an increase (25–30 layers, week 6) and later on by a decrease of cell layers in the epithelium (15–20 layers, week 20). From that time onwards, clear stratification and rete‐ridges as signs of differentiation were present. Up to day 14 of graft take, the linear staining patterns for laminin and collagen IV were interrupted, which was not observed at any later stage. During this early interval CK5/6, CK1/2/10/11, CK14 and CK17 were expressed in all epithelial layers. The reactions for CK5/6 and CK1/2/10/11 were less intensive. At 6 weeks, CK1/2/10/11 stained the intermediate and superficial layers, being consistent with findings after longer graft take. CK5/6 reacted in the basal and intermediate cell layers, and CK13, CK14 and CK17 reacted in all layers. In the following period up to week 20, CK5/6 were found in the parabasal cells of the intermediate cell layers and the basal cells. CK14 staining was confined to these cell layers too, but also showed some reaction in the superficial layers. CK13 and CK17 were still bound to all layers. At 7 months post‐operative, CK5/6 and CK14 were seen in their typical localisation in the basal cell layer and the parabasal cells of the intermediate layers, CK17 was seen mainly in the intermediate layer and CK13 was seen in focal areas of all layers. Anti‐CK19 reacted only with single basal and parabasal cells up to week 20. These results suggest that during healing of mucosal autografts there is a sequence of changes in the expression of cell biological differentiation markers that may involve an epithelio‐connective tissue interaction before the typical patterns for the donor side were observed again on the gingiva or mucosa of the hard palate.
Comparison of apoptosis and apoptosis‐related gene products between extranodal oral B‐cell lymphoma and maxillofacial nodal B ‐ cell lymphoma
Authors: Yin Hong‐fang , Okada Norihiko , Takagi Minoru
Published: March 2003

Abstract: Twenty‐seven cases of primary extranodal oral B‐cell lymphoma and 22 cases of primary maxillofacial nodal B‐cell lymphoma were investigated for the presence of apoptotic cells and the expression of apoptosis‐related gene products by terminal deoxynucleotidyl‐mediated dUTP nick end labeling (TUNEL) and immunohistochemistry. The majority of extranodal oral diffuse large B‐cell lymphomas (17/25, 68%) and maxillofacial nodal diffuse large B‐cell lymphomas (14/16, 88%) contained no or less than 10% apoptotic cells. Whereas the majority of extranodal oral diffuse large B‐cell lymphomas (18/25, 72%) and maxillofacial nodal diffuse large B‐cell lymphomas (13/16, 81%) contained more than 10% of Ki‐67‐positive cells. Bcl‐2‐, Bax‐, p53‐ and Ki‐67‐positive rates were higher in maxillofacial nodal diffuse large B‐cell lymphomas than in extranodal oral diffuse large B‐cell lymphomas, but only Bax (χ2 test, 0.01<P<0.025) and p53 (χ2 test, 0.005<P<0.01) had significant differences. Extranodal oral diffuse large B‐cell lymphomas had a higher frequency of TUNEL expression than maxillofacial nodal diffuse large B‐cell lymphomas. In maxillofacial nodal diffuse large B‐cell lymphomas, stage III and stage IV tumors had a significantly higher frequency of Bcl‐2 expression than stage I and stage II tumors (Fisher’s exact test, P<0.01). These findings indicated that in the majority of both extranodal oral and maxillofacial nodal diffuse large B‐cell lymphomas, apoptosis was inhibited – whereas proliferative activity was accelerated. Impairment of apoptosis and apoptotic related gene products may have a more important relation to maxillofacial nodal diffuse large B‐cell lymphoma than extranodal oral diffuse large B‐cell lymphoma.
Reactive pocket epithelium in untreated chronic periodontal disease: possible derivation from developmental remnants of the enamel organ and root sheath
Authors: Hunter Neil , Nicholls Brent , Srivastava Mukesh , Chapple Cheryl C. , Zoellner Hans F. , Gibbins John R.
Published: March 2003

Abstract: The pathological lining epithelium of destructive periodontitis was studied by analysis of the expression of intermediate filament proteins in biopsies of untreated advanced periodontitis. The cytokeratin (CK) pair 8/18 characteristic of simple epithelia was expressed consistently in a distribution pattern confined to the reactive pocket epithelium. The pattern of CK8/18 expression was complex with two broad presentations evident. In two‐thirds of the advanced disease biopsies, the entire pathological lining epithelium was strongly reactive for both CK8 and CK18. In the remainder, the more superficial lining epithelium was mixed with foci of reactive and unreactive cells, with the deeper epithelium uniformly reactive. Only occasional highly localised reactivity for the simple keratins (CK8/18) was found in the lining epithelia of biopsies from minimally inflamed periodontal tissues. The pathological lining epithelium of advanced periodontitis was further characterised by the co‐expression in basal layers of CK14, and of CK13 but not CK4, which are characteristic of suprabasal layers of stratified squamous epithelia. Cytokeratin 17, a marker of high turnover and migrating epithelial cells was extremely variable with no clear association between expression pattern and location of the epithelium or disease status. There was no reactivity for CK10/11 typical of cornifying cells nor of vimentin, the characteristic intermediate filament of mesenchymal cells. The intermediate filament protein profile of the reactive lining epithelium was indistinguishable from the reactive epithelium present in three of five biopsies of periapical granulomas containing hyperplastic epithelium from activation of the developmental remnants of Hertwig’s sheath, known as the cell rests of Malassez. The data reported are compatible with a contribution by remnants of developmental epithelium, including the reduced enamel epithelium and the cell rests of Malassez, to the reactive lining epithelium of the subgingival pocket in the pathogenesis of chronic periodontitis.
Expression of hMSH2 and hMLH1 proteins of the human DNA mismatch repair system in ameloblastoma
Authors: Castrilli Graziella , Piantelli Mauro , Artese Luciano , Perfetti Giorgio , Rubini Corrado , Fioroni Massimiliano , Ranelletti Franco O. , Piattelli Adriano
Published: March 2003

Abstract: The human DNA mismatch repair (hMMR) system plays an important role in reducing mutation and maintaining genomic stability. The MMR system in human cells is composed of at least six genes (hMSH2, hMLH1, hMSH3, hPMS1, hPMS2 and GTBP/hMSH6). In particular, hMSH2 and hMLH1 are expressed in human cells that are undergoing rapid renewal; their reduced expresion has been reported in several tumors. We examined the protein expression pattern of hMSH2 and hMLH1 by immunohistochemistry in 25 ameloblastomas. All ameloblastomas expressed hMSH2 and hMLH1 proteins in the outer layer of epithelial cells. The localization of the staining was exclusively nuclear. These data suggest that the development and progression of these tumors do not depend on a defect in the hMMR system.
Epithelial–mesenchymal interactions in experimental oral mucosal carcinogenesis
Authors: Rich Alison M. , Reade Peter C.
Published: March 2003

Abstract: In an effort to come to a better understanding of human oral mucosal carcinogenesis, an animal model was used in which the carcinogen 4‐nitroquinoline‐1‐oxide was applied to rat palatal mucosa for varying periods of time. Histological and histometric analyses showed that there were quantifiable differences in the palatal epithelium to which carcinogen had been applied in comparison with control tissue. Tissue recombination experiments, using various combinations of the palatal mucosa and analysed after recovery from transplantation to hypothymic BALB/c mice, showed that control epithelium recombined with connective tissue from carcinogen‐treated mucosa was altered, indicating that the underlying connective tissue modified histomorphological aspects of the epithelium in the later stages of carcinogenesis.
Immunohistochemical analysis of cell‐cycle‐ and apoptosis‐related factors in lining epithelium of odontogenic keratocysts
Authors: Kimi Kenji , Kumamoto Hiroyuki , Ooya Kiyoshi , Motegi Katsutoshi
Published: March 2003

Abstract: We examined the immunohistochemical expressions of cell‐cycle‐ and apoptosis‐related factors to investigate the possible role of these factors in odontogenic keratocyst (OKC). Expression of cyclin D1 and p16 protein was detected in the basal and parabasal cells in lining epithelium of OKCs and was found more frequently in basal cell nevus syndrome (BCNS)‐associated OKCs than in primary or recurrent OKCs. Positivity for p21 protein was detected in basal to superficial cells, whereas that for p27 protein was detected in parabasal to superficial cells in lining epithelium of OKCs. DNA topoisomerase IIα reacted with nuclei in basal and parabasal cells of the lining epithelium of OKCs, and positive cells were observed in BCNS‐associated OKCs significantly more frequently than in primary or recurrent OKCs. Expression of Fas in suprabasal to superficial cells and expression of Fas‐L in basal and parabasal cells were detected in lining epithelium of OKCs. Immunoreactivity for caspase‐3 was detected in basal to suprabasal or superficial cells in lining epithelium of OKCs. Single stranded (ss)DNA‐positive nuclei were detected in superficial cells in lining epithelium of OKCs. Fas was more broadly distributed in BCNS‐associated OKCs than in primary OKCs, and ssDNA‐positive cells were observed in BCNS‐associated OKCs significantly more frequently than in primary or recurrent OKCs. These results suggest that BCNS‐associated OKCs might be a distinguishable entity from solitary OKCs.
Epidemiological aspects of oral and pharyngeal cancers in the Basque Country
Authors: Izarzugaza M. Isabel , Esparza Hortensia , Aguirre J. Manuel
Published: March 2003

Abstract: Oral and pharyngeal cancer is an entity constituted by a group of tumours that arise in several heterogeneous anatomical sites, and for this reason it is difficult to establish comparisons. The aim of the study was to describe the characteristics of oropharyngeal cancer in the Basque Autonomous Community (BAC), to learn the incidence rate and to establish comparisons. Data of cases are from the Basque Country Cancer Registry for the period 1986–1994, and the methodology used is descriptive. We included 2548 cases, and the sex ratio was 7.4:1. Diagnosis was made by histology in most cases (99%). The crude incidence rate was 24.1/100,000 population for men and 3.1/100,000 for women. Higher incidence rates were found in the tongue (6.6), lip (5.8) and oropharynx (4.9). No variation was found in the incidence during the period. In comparison with other Spanish registries, there is a high incidence in men of cancer in the oral cavity. The results obtained show the characteristics of oral and pharyngeal cancer in the BAC and its magnitude, highlighting the importance of future preventive actions.
The correlation between alteration of p16 gene and clinical status in oral squamous cell carcinoma
Authors: Tsai Chung‐Hung , Yang Chi‐Chiang , Chou Lin Shin‐Shen , Chou Ming‐Yung
Published: March 2003

Abstract: The purpose of the study was to evaluate the presence of alteration of the tumor suppressor gene p16 and to correlate these changes with the clinical status of the patients in oral squamous cell carcinoma. Forty‐eight oral squamous cell carcinomas were included in the analyses. Deletion analysis was performed by the polymerase chain reaction (PCR). Mutation analysis was restricted to exon 1 and exon 2 of the p16 gene, previously shown to have a high incidence of mutations. The sequences containing exon 1 and exon 2 were amplified by PCR and screened with a single‐strand conformation polymorphism (SSCP) technique. Samples showing band shifts in SSCP were sequenced by PCR direct sequencing. Western blots were used to detect the protein expression of the p16 gene, and the results were evaluated with regard to their biological relevance in correlation with clinicopathological factors. Seven (14.6%) deletions were found; 5 (10.4%) mutations were discovered and located in different codons; 26 (54%) specimens had no p16 protein expression; in 11 specimens with p16 deletion or mutation, p16 protein could not be detected. One mutation was non‐sense. The p16 gene alterations showed no relationship with location and clinical stage of cancer; however, a close relationship between p16 alterations and cancer metastasis to neck lymph node was found. The alteration rate gradually elevated from well to poorly differentiated grades. We perceive two results. First, the alterations of the p16 gene are common in oral squamous cell carcinoma. Second, the alterations of the p16 gene may attribute to the metastatic behavior or histological grade of cancer cells.
Clear cell odontogenic carcinoma of the mandible
Authors: Mosqueda‐Taylor Adalberto , Meneses‐García Abelardo , Ruíz‐Godoy Rivera Luz María , De Lourdes Suárez‐Roa María
Published: March 2003

This article describes a case of clear cell odontogenic carcinoma (CCOC) in a 55‐year‐old woman who presented such a tumor extending from the midline of the mandible to the right first molar. The tumor was surgically excised and has not recurred or metastasized 6 months after surgery. To date, only 33 well‐documented cases have been reported (including the present case) in the English literature. Twenty‐eight (84.8%) have developed in the mandible and five (15.2%) in the maxilla. Eighteen (54.5%) occurred anterior to the first molar. The vast majority have been diagnosed in patients older than 40 years (30/33), and the mean age at diagnosis is 57.4 years (range: 17–89), with a male/female ratio: 1/2. Recurrences have been described in 17 cases (51.5%) and metastasis in 10 (30.3%). Based on its morphologic, histochemical and immunophenotypic features, CCOC should be distinguished from other primary and metastasic clear cell tumors of the oral and maxillofacial regions.
Immunohistochemical evidence of PTEN in oral squamous cell carcinoma and its correlation with the histological malignancy grading system
Authors: Squarize Cristiane Helena , Castilho Rogério Moraes , Pinto Décio Santos
Published: March 2003

PTEN is a tumor suppressor gene that encodes a dual phosphatase protein capable of modulating membrane receptors and interaction of the cell and extracellular stimuli. PTEN regulates cell physiology such as division, differentiation/apoptosis and also migration and adhesion. The expression of PTEN was evaluated by immunohistochemistry in OSCC and compared to a well‐established histological malignancy grading system. The well‐differentiated OSCC were 59.1% and poorly differentiated were 40.9%. According to PTEN expression, the cases were 45.5% positive (the entire tumor showed stained), 22.7% mixed (both negative and positive cells were present) and 31.8% negative (no staining was seen in the tumor cells). PTEN expression in OSCC was related to the malignancy grade (P < 0.0005). Aggressive tumors with a high score of malignancy did not express PTEN, and clearly, the PTEN expression was present in the epithelium adjacent to the tumor. Negative cells were in the invasion border of the tumor. This result suggests that PTEN is related to histologic pattern and biological behavior of OSCC and may be a used as a prognostic marker in the future. The role of PTEN during carcinogenesis and as a biomarker should be further investigated.
SPARC stimulates the synthesis of OPG/OCIF, MMP‐2 and DNA in human periodontal ligament cells
Authors: Fujita Tsuyoshi , Shiba Hideki , Sakata Masatoshi , Uchida Yuushi , Nakamura Shigeo , Kurihara Hidemi
Published: March 2003

Background:  Osteonectin/secreted protein, acidic and rich in cysteine (SPARC) is expressed in periodontal ligaments. Therefore, a better understanding of the action of SPARC on periodontal ligament cells could help to elucidate remodelling and repair mechanisms in periodontal tissue. In the present study, we examined the effects of human platelet‐derived SPARC (hp‐SPARC) on the expressions of SPARC and osteoprotegerin/osteoclastogenesis inhibitory factor (OPG/OCIF), alkaline phosphatase (ALPase) activity, matrix metalloproteinase‐2 (MMP‐2) production and DNA synthesis in cultures of human periodontal ligament (HPL) cells.

Methods:  HPL cells at the sixth passage were exposed to hp‐SPARC. The expression of OPG/OCIF and SPARC mRNAs was examined by Northern blot analysis. The protein levels for OPG/OCIF and MMP‐2 were determined by Western blot analysis. ALPase activity was measured by the method of Bessey et al. DNA synthesis was estimated by incorporation of [3H]thymidine.

Results:  Hp‐SPARC enhanced OPG/OCIF synthesis at the protein and mRNA levels. Hp‐SPARC also enhanced DNA and MMP‐2 synthesis dose‐dependently, but had little effect on ALPase activity and SPARC mRNA expression.

Conclusion:  SPARC may play a role in remodelling and repair of periodontal tissue by promoting proliferation and MMP‐2 production. It may also regulate osteoclast formation through OPG/OCIF in periodontal ligament cells.
The effect of diabetes mellitus on the expression of Argyrophilic nucleolar organizer regions (AgNORs) in mucosal epithelium under experimental denture bases in rats
Authors: Maruo Yukinori , Sato Takashi , Hara Testuya , Mori Shingo , Shirai Hajime , Minagi Shogo
Published: March 2003

Background:  Expression of argyrophilic nucleolar organizer regions (AgNOR) was counted on mucosal epithelium to detect whether the AgNOR count (the number of AgNOR per nucleus) is, for 20 weeks, affected by streptozotocin‐induced diabetes mellitus.

Methods:  Diabetic rats were applied non‐denture wearing, non‐pressure contact, continuous pressure (0.5, 1.5 or 3.4 kPa) and intermittent pressure (10.5, 33.0 or 81.7 kPa), respectively.

Results:  In the non‐denture wearing or the non‐pressure contact group, AgNOR count was almost constant (ranging 1.86–1.92) without significant difference. Under continuous pressure, AgNOR count significantly decreased at earlier stage and finally recovered to the non‐pressure contact group. A similar effect of continuous pressure appeared to manifest itself in intermittent pressure, but to a greater degree. Consequently, AgNOR count under intermittent pressure showed no recovery at 20‐week stage.

Conclusion : Diabetes mellitus exerted, by itself, no influence on the cellular proliferative activity under continuous pressure, whereas the activity deteriorated under intermittent pressure.