bluuebunny/crossref_metadata_2025 huggingface dataset:
The insulin‐like growth factor binding protein 3 ternary complex is reduced in cirrhosis
Authors: Ottesen Lone Harild , Bendtsen Flemming , Flyvbjerg Allan
Published: March 2003

Abstract: Background/Aims: In healthy adults, serum insulin‐like growth factor I (IGF‐I), IGF binding protein 3 (IGFBP‐3) and acid labile subunit (ALS) form a 150‐kDa ternary complex under the control of growth hormone (GH). Approximately 80–90% of circulating IGF‐I is bound to the ternary complex. In cirrhosis the GH/IGF axis is severely disturbed and the individual components of the ternary complex are reduced. However, the degree of ternary complex formation in cirrhosis has not previously been described. Methods: Serum IGF‐I, IGFBP‐3, ALS, the 150‐kDa ternary complex and IGFBP‐3 proteolysis were all measured in six compensated and six decompensated cirrhotic patients and compared to six healthy controls. Results: Patients with compensated cirrhosis had decreased levels of IGF‐I (55%), IGFBP‐3 (64%) and ALS (53%), and in the decompensated patients these levels were decreased even further: IGF‐I (32%), IGFBP‐3 (37%) and ALS (27%) compared to healthy controls. The levels of the ternary complex followed this pattern, with low levels seen in the compensated patients (66%) and a further reduction in the decompensated patients (27%). Ternary complex levels correlated negatively with the Child–Pugh score. No increase in IGFBP‐3 proteolysis was found in cirrhotic patients compared to healthy controls. Conclusion: Cirrhosis is associated with reduced levels of the 150‐kDa ternary IGFBP‐3 complex correlating with the degree of liver disease.
Yersinia pseudotuberculosis infection in breeding monkeys: detection and analysis of strain diversity by PCR
Authors: Kageyama T. , Ogasawara A. , Fukuhara R. , Narita Y. , Miwa N. , Kamanaka Y. , Abe M. , Kumazaki K. , Maeda N. , Suzuki J. , Gotoh S. , Matsubayashi K. , Hashimoto C. , Kato A. , Matsubayashi N.
Published: March 2003

In the last three decades, several monkeys reared in outdoor/indoor–outdoor breeding colonies and cages of the Primate Research Institute, Kyoto University, died of yersiniosis caused by Yersinia pseudotuberculosis, necessitating introduction of a method to detect the bacteria rapidly and thus allow preventive measures to be undertaken. A rapid nested polymerase chain reaction (PCR) method for identification of Y. pseudotuberculosis in fecal samples and a random amplified polymorphic DNA (RAPD)‐PCR approach for distinguishing between bacterial strains were therefore developed. Yersinia pseudotuberculosis isolates from monkey specimens were found to be classifiable into several types. To determine the source of infection, hundreds of fecal samples of wild rats, pigeons, and sparrows were collected from around the breeding colonies and cages, and subjected to PCR analyses. Yersinia pseudotuberculosis was detected in 1.7% of the fecal samples of wild rats. The DNA fingerprints of the bacteria revealed by RAPD‐PCR were the same as that of one strain isolated from macaques, suggesting the wild rat to be a possible source of infection.
Physical modelling of a sidewall‐blowing converter
Authors: Fabritius Timo , Kupari Pentti , Härkki Jouko
Published: March 2003

The flow patterns of the chromium converter (CRC) during top and side‐wall blowing have been studied using a physical model (1:7). The dynamic similarity between model and real system has been determined by the Froude number and specific mixing energy. This ensures reliability of model studies, although some simplifications have had to made. The model tests demonstrated clearly that mixing was not sufficient to form slag‐steel emulsion by the old blowing practice. Furthermore, the mixing time was 27% shorter in the model by the new practice according to conductivity measurements. Calculations and process tests indicated that back‐attack diminished and penetration of gas jets to the steel bath increased. The blowing practice of the CRC has been changed, based on the model tests and semi‐empirical calculations. The portion and amount of inert gas from the sidewall tuyeres have been increased and oxygen is brought mainly with a lance to liquid steel. In the previous practice, minor penetration of gas jets and hot reactive oxide mass effected an uneven wearing profile of tuyere area. The addition of an inert gas volume rate prevented forming of ‘hot spot’ areas near uyeres. As a result of practice change, the lining life in the tuyere area has increased by 12%. The processing time has decreased by 13% because of a more effective mixing and increased oxygen flowrate.
Metallurgical performance of the water‐cooled lance at the BHP Sydney Steel Mill
Authors: Lee Mark , Caffery Grant , Molloy Nei
Published: March 2003

This paper describes the findings of a water‐modelling study conducted on a 1/3 scale model of the Electric Arc Furnace (EAF) at BHP’s Sydney Steel Mill (SSM). The aim of the study was to improve operation of SSM super‐sonic, water‐cooled oxygen lance. The study consisted of 2 sections. The first was a study of the effect of lance vertical and horizontal angle on bath flow patterns. The second was a study of the effect of lance vertical angle height and flow rate on splash generation. From this investigation the preferred lance operating conditions have been determined.
Physical modelling of hot metal flow in a blast furnace hearth
Authors: Luomala Matti Juhani , Mattila Olli Juhani , Härkki Jouko Juhani
Published: March 2003

Physical modelling was applied in order to gain information about the flow behavior in the blast furnace hearth. For that purpose, residence times of tracer injections were determined based on the electric conductivity measurements and flow paths were visualised by using KMnO4 (s). Especially the influence of a floating coke bed and blocked center of the deadman on flow characteristics in the blast furnace hearth were investigated using a ring‐shaped distributor and penetrated taphole, simulating sintered mud mass. When a coke‐free space is formed under the coke bed, the iron discharge route forms a V‐shaped cross‐sectional area in which iron flows completely inside the coke bed. The share of iron entering the V‐shaped area can be increased either by increasing the drain rate or by decreasing the height of the coke‐free layer. Inactive center of deadman causes iron to flow near the hearth wall which leads to severe erosion of hearth.
The production of low phosphorus and nitrogen steelsin an EAF using HBI
Authors: Lee Mark , Trotter David , Mazzei Orlando
Published: March 2003

Commercially‐produced hot briquetted iron (HBI) contains considerably more phosphorus than scrap. This raises the question of how much dephosphorisation can be achieved when using HBI in an electric arc furnace (EAF), or in oxygen steelmaking, and what the cost of this dephosphorisation will be. A commonly held misconception amongst EAF operators who do not currently use HBI, is that the relatively high level of phosphorus in HBI will make dephosphorisation difficult, if not impossible. The experience of EAF operators who do currently use HBI is that dephosphorisation is easily achieved, with no cost penalty, when a conventional flush slag practice is employed. The production of low phosphorus steel from a high phosphorus HBI charge, with no associated cost penalty, has been demonstrated by trials conducted at BHP’s Sydney Steel Mill and routine practice at CASIMA in Venezuela and other EAF operators.
Influence of temperature on the wettability at theslag/carbon interface during pulverised coal injection in a blast furnace
Authors: Mehta A. S. , Sahajwalla V.
Published: March 2003

One of the factors that could limit the maximum rate of pulverised coal injection (PCI) in a blast furnace is the accumulation of unburnt char, due to incomplete combustion. Consumption of this unburnt char in the blast furnace could result in achieving increased PCI rates. The Co‐operative Research Centre (CRC) for Black Coal Utilisation in Australia, is engaged in several projects to develop an understanding of the possible modes of consumption of the unburnt char within a blast furnace, through investigation of the interaction of different carbonaceous materials with slag, metal and gas phases. This paper presents some of the results of the investigation of slag/carbon interactions, studied in terms of the wettability at the slag/carbon interface. Influence of temperature on the wettability at slag/carbon interface has been investigated by measuring the variation of dynamic contact angle with time, at 3 different temperatures, 1500 °C, 1600 °C and 1700 °C for a blast furnace slag composition interacting with various carbonaceous materials, including graphite and chars. An increase in temperature generally results in improved wettability at the slag/carbon interface. The wetting behaviour of the slag on different carbonaceous materials can be explained on the basis of the changes in the interfacial energy during the interaction. An increase in temperature is associated with a greater decrease in interfacial energy due to an increased extent and rate of the reduction reactions and a decrease in surface tension of the slag. This paper discusses the wettability of various carbonaceous materials by the slag at different temperatures and the associated phenomena.
Are land bird assemblages functionally saturated? An empirical test in Mexico
Authors: De Silva Héctor Gómez , Medellín Rodrigo A.
Published: March 2003

According to the model of ideal free distribution, few or no assemblages will contain unused resources as long as species are free to colonize areas where resources are available. Consequently, because several food resources for birds are available throughout Mexico (nectar, seeds and fruits, vertebrates, carrion and different types of invertebrates), we predicted that all assemblages from Mexico contain birds from the corresponding foraging guilds. However, severe climates may prevent colonization by certain birds. Thus, a second prediction was that, if assemblages with unused resources were found, these would be from localities with climates that pose extreme stress (either extremely high temperature and low rainfall, or extremely low temperature). We tested these predictions on bird assemblages from 77 localities that represent the entire range of climatic conditions found in Mexico. Only two assemblages containing unused resources were found. These were from the localities with lowest temperature and lowest rainfall, respectively. We observed that land bird assemblages in Mexico do not contain unused resources, except when climate selectively restricts colonization by species from certain foraging guilds. Therefore, we conclude that even assemblages with almost no species in common have a common guild structure based on food resources. Null models of competition would be more realistic if they were to incorporate such patterns in their regional species pools.
Can saliva from moose, Alces alces, affect growth responses in the sallow, Salix caprea?
Authors: Bergman Margareta
Published: March 2003

Herbivores have the potential to affect the morphological traits of the plants they feed on, such as the breaking of apical dominance that occurs when shoot tips are browsed, leading to increased lateral branching and decreased competition among growing points. Despite such effects, however, it remains unclear whether components in the saliva of the browsing animals are directly involved in amplifying and/or reducing the plant growth responses. To test this possibility, a controlled experiment was performed in which herbivory by moose (Alces alces) was simulated by tearing 60 sallow saplings (Salix caprea) with a moose jaw. Of these 60, half were also treated with moose saliva. Selected growth traits of the torn plants with and without saliva treatment were examined directly after treatment (week 0) and 1, 2, 4, 6, 8, 10, 12 and 15 weeks after the tearing. Also included in the study was an untreated (no tearing, no saliva) control group of another 30 sallow saplings. Traits monitored on the saplings were height and the number of branches, buds and leaves. Application of moose saliva on torn saplings led to significantly more branches than on saplings without saliva treatment. Moose saliva, however, had no significant effects on the other growth traits, although for most of these characteristics both groups of torn saplings showed increased values compared to the undamaged control. Overall, these results demonstrate that moose saliva has a consistent stimulatory effect on branching of sallow saplings but not on the other growth traits examined in this study.
Evidence of phosphorus‐limited individual and population growth of Daphnia in a Canadian Shield lake
Authors: Makino Wataru , Urabe Jotaro , Elser James J. , Yoshimizu Chikage
Published: March 2003

We performed bag experiments in a Canadian Shield lake with generally high seston (suspended food particles mainly composed of algae) carbon (C):phosphorus (P) ratios, and investigated the responses of individual and population growth of herbivorous Daphnia dentifera on their abundance with (+P) and without (−P) a phosphorus enrichment to lake water. In both treatments, increased abundance of D. dentifera reduced seston C concentration and was accompanied by decreases in population and individual growth rates. However, P‐enrichment increased seston P concentration and then reduced seston C:P ratio from 400–700 to ca 100 (by atoms). As a result, both individual and population growth rates were significantly higher in the +P treatment at all animal abundances even though seston C concentrations were similar between the treatments. The magnitude of the growth enhancement by the P‐enrichment was independent of animal abundance. Stepwise regression analyses revealed that 71 and 90% of the variance in the population and individual growth rates, respectively, were explained by seston C and P concentrations, and that the contribution of the seston P concentration was roughly the same as that of seston C. Such joint effects of seston C and P indicate that food quality (P content) as well as food quantity (C concentration) can influence Daphnia not only at the level of individual growth but also at the level of population dynamics in P‐limited lakes. Our results thus strongly corroborate the hypothesis that the population development of a key herbivore Daphnia in P‐limited Canadian Shield lakes is inhibited by the direct effects of P‐limited food on individual growth, which weaken the strength of trophic cascading interactions starting from piscivorous fish through planktivorous fish and zooplankton to algae.
Sexual dimorphism in Odonata: age, size, and sex ratio at emergence
Authors: Crowley Philip H. , Johansson Frank
Published: March 2003

Males and females of many organisms differ in important life‐history and behavioral characters. Following a recent optimization analysis of sexually dimorphic life histories, we employed an odonate‐like parameter set to identify patterns of life history and behavior to be expected in an odonate population. The default parameter magnitudes generated a smaller body size and shorter development time for males than for females, which resulted in a male‐biased sex ratio. Whether population growth was density dependent or density independent, and whether development time was fixed or flexible had major impacts on life‐history features. The model generated five general predictions for odonate systems. (1) For species with fixed development times, males and females should differ more in activity level, growth and mortality rates than for species with flexible life cycles. (2) In species with fixed development times, populations at high latitude or high altitude should be more active, emerge and reproduce at smaller size and have a more male‐biased sex ratio than low latitude and low altitude populations. (3) In density‐dependent populations, with density dependence mediated by activity‐dependent mortality, higher predation rates should increase activity levels and reduce development time in species with flexible development times. (4) For species with flexible development times, in strongly density‐dependent populations with density dependence mediated by mortality, activity levels should decrease and development times should increase at high prey abundance. (5) Males should be larger at emergence relative to females, and the sex ratio at emergence should be more female‐biased in territorial than in non‐territorial species. Existing empirical evidence concerning these predictions is generally sparse and equivocal; focused tests are clearly needed.
Predicting invertebrate diversity from disturbance regimes in forest streams
Authors: Death Russell G.
Published: March 2003

The link between substrate disturbance and stream invertebrate species richness is often complicated by the fact that substrate disturbance removes both invertebrates and periphyton (a potential food source). It is never clear whether disturbance acts directly on species diversity by removing animals or indirectly by reducing one of their food sources. To examine this relationship invertebrate diversity patterns were examined in 25 forest streams in Urewera National Park, New Zealand, where light attenuation from the forest canopy was postulated to limit periphyton biomass and remove the confounding influence of periphyton on the link between substrate disturbance and invertebrate diversity. Invertebrate species richness declined linearly with increasing substrate disturbance. Although periphyton biomass was comparatively low, species richness was more strongly related to periphyton biomass than to any disturbance measure. The highly mobile nature and terrestrial reproductive stage of many lotic invertebrates suggest that colonisation dynamics may have a more important influence on diversity patterns than monopolisation of resources for population growth. Although both the intermediate disturbance hypothesis and the dynamic equilibrium model encompass colonisation as a critical determinant of diversity both models also require a trade‐off between the colonising and competitive ability of individual species; a phenomenon which does not appear to occur widely in lotic communities. Rather, it is postulated that resource levels will set an upper limit to the species richness of a benthic community that can be achieved through colonisation of taxa in the absence of disturbance, while disturbance removes taxa and resets the colonisation process.
Disturbance and recovery following catastrophic grazing: studies of a successional chronosequence in a seagrass bed
Authors: Peterson Bradley J. , Rose Craig D. , Rutten Leanne M. , Fourqurean James W.
Published: March 2003

In August 1997, a large aggregation of the common sea urchin, Lytechinus variegatus, was discovered moving southward through a lush and productive seagrass monoculture of Syringodium filiforme in the Florida Keys, FL. Sea urchin densities at the grazing front were greater than 300 individuals m−2 which resulted in the overgrazing of seagrasses and a complete denuding of all vegetation from this area. The steady rate of the grazing front migration permitted the estimation of the time since disturbance for any point behind this grazing front allowing the use of a chronosequence approach to investigate the processes early on in succession of these communities.  In May 1999, six north‐south parallel transects were established across the disturbed seagrass communities and into the undisturbed areas south of the grazing front. Based on the measured rates of the migration of the grazing front, we grouped 60 sites into five categories (disturbed, recently grazed, active grazing front, stressed and undisturbed). The large scale loss of seagrass biomass initiated community‐wide cascading effects that significantly altered resource regimes and species diversity. The loss of the seagrass canopy and subsequent death and decay of the below‐ground biomass resulted in a de‐stabilization of the sediments. As the sediments were eroded into the water column, turbidity significantly increased, reducing light availability and significantly reducing the sediment nitrogen pool and depleting the seed bank. The portion of the chronosequence that has had the longest period of recovery now consists of a mixed community of seagrass and macroalgae, as remnant survivors and quick colonizers coexist and jointly take advantage of the open space.
Spatial interaction models: from human geography to plant‐herhivore interactions
Authors: Oom S. P. , Hester A. J. , Elston D. A. , Legg C. J.
Published: March 2003

The spatial pattern of defoliation by mammalian herbivores across vegetation mosaics bas been frequently discussed, but rarely spatially quantified. Here we considered the role of plant‐herbivore interactions in determining the spatial distribution of shrub defoliation by a large mammalian herbivore across a grass‐shrub mosaic.  We investigated the spatial pattern of heather defoliation by sheep in heather‐grass mosaics. Heather‐grass mosaics are two‐phased vegetation mosaics, in which a spatially localized plant community (grass) fulfils nutritional needs, whilst a spatially extensive plant community (heather) meets energy requirements but is nutritionally marginal.  We used a spatial analysis method, originating from human geography, to show that heather defoliation was not spread across the mosaic homogeneously, but that the spatial pattern was determined by geometric characteristics of the mosaic, grazing intensity, and the contrast between preferred and less preferred communities.  The spatial analysis method proved to be a powerful tool to describe the spatial pattern of shrub defoliation. Applications of the method are explored and the implications of the spatial distribution of shrub defoliation are discussed.
Host‐parasitoid dynamics in periodic boreal moths
Authors: Várkonyi Gergely , Hanski Ilkka , Rost Martin , Itämies Juhani
Published: March 2003

Numerous insect species with fixed multiannual life cycle emerge synchronously in large numbers, mostly with a period of two or three years. Moths in the genus Xestia with a two‐year life cycle are strikingly abundant in boreal forests around the Northern Hemisphere every second year but scarce in alternate years. Many hypotheses have been put forward to explain their periodic occurrence, including interaction with natural enemies. Here we present biological, numerical and modelling evidence strongly suggesting that the scarcity of the even‐year cohorts of eight coexisting Xestia species in eastern Finnish Lapland is due to regulation by the parasitoid wasp Ophion luteus, possibly reinforced by predation by shrews.
Disease resistance in Arabidopsisthaliana increases the competitive ability and the predicted probability of long‐term ecological success under disease pressure
Authors: Damgaard Christian , Jensen Brita D.
Published: March 2003

Disease resistance is believed to play a role in the dynamics of plant communities and plant populations. Here we study the competitive ability of two Arabidopsisthaliana genotypes, one exhibiting resistance and the other exhibiting susceptibility to an isolate of Peronospora parasitica. The A.thaliana genotypes were grown in competition experiments under controlled conditions at three densities in pure and mixed stands both in the presence and absence of P. parasitica. After seed set, the dry weight of the plants was determined and the amount of seeds produced was calculated from an established linear relationship. The two genotypes were found to be ecologically different; the susceptible genotype was the strongest competitor (significantly so in the absence of the disease), whereas the resistant genotype produced most seeds. The competitive ability of the disease resistant A.thaliana genotype increased significantly in the presence of a P. parasitica isolate when competing with the susceptible A.thaliana genotype, whereas the disease did not affect the competitive ability of the susceptible genotype significantly. Assuming that the population only consisted of the two genotypes and mainly was affected by the disease it was possible to predict the probabilities of four long‐term ecological scenarios. Without the disease the most likely long‐term ecological scenario was that the two A.thaliana genotypes would coexist, whereas, in the presence of the disease, the resistant genotype most likely would outcompete the susceptible genotype.
Grazing refuges, external avoidance of herbivory and plant diversity
Authors: Milchunas D. G. , Noy‐Meir I.
Published: March 2003

Avoidance and tolerance are the two means by which plants cope with herbivores. Avoidances internal to the plant, such as morphology, chemical repellants, thorns, etc., have received considerable attention in the plant‐herbivore literature, but relatively little consideration has been given to avoidances external to the plant. We develop a conceptual framework of external plant avoidances of herbivory based on foraging selection impedances (associational avoidances), behavioral impedances (indirect avoidances), and physical impedances (refuges) organized along axes of efficiency, degree of protection, and necessity of tolerance characteristics. Associational avoidances are uncommon for terrestrial mammalian herbivores compared to plant‐insect or marine situations. Indirect avoidances mediated through herbivore territoriality, predator avoidance, and other behaviors independent of foraging decisions are probably common in nature, but few have been formally documented. Biotic and geologic refuges providing a physical impedance are the only avoidances shown to have implications for plant biodiversity. This is particularly true for geologic refuges, where there is not a tradeoff between competition and the refuge effect. Small geologic refuges (rock outcrops, cliffs, etc.) are more likely to also positively or negatively alter associated plant microenvironments than large geologic refuges (mesas, islands, etc.). In a survey, 86% of small refuge studies reported positive effects on plant diversity compared to 50% for large refuges. Geologic refuges in more productive environments were more important in protecting diversity than refuges in less productive, semiarid environments, and the effects of protection were greater in communities with short compared to long evolutionary histories of grazing. Other characteristics of refuges such as extent across the landscape and the manner they alter or ameliorate the environment, as well as characteristics of the herbivore such as small or large, generalist or specialist may also determine the effectiveness of refuges, but there are too few studies to assess these factors.
Oral mucosal Langerhans’ cells as target, effector and vector in HIV infection
Authors: Chou L. L. , Epstein J. , Cassol S. A. , West D. M. , He W. , Firth J. D.
Published: March 2003

Abstract: The mechanism underlying a transition of the oral cavity mucosal epithelium towards susceptibility to opportunistic infections in HIV‐seropositive patients was investigated. Phenotypic markers CD1a, HLA‐DR, and CD86 of oral mucosal Langerhans’ cells (LCs), p17 core protein of human immunodeficiency virus (HIV), and CD45RO of memory T cells were labeled on oral hairy leukoplakia lesional biopsies and clinically normal autologous tissue of HIV‐infected patients. HIV p17 protein was detected in association with mucosal LCs, mainly within the lesional epithelium. There were significant correlations between the detection of HIV p17 and the depletion of LCs, and between the depletion of LCs and the presence of hairy leukoplakia lesions. Conjugates of activated LCs and memory T cells were also evident in the submucosal area of lesional biopsies. The findings from this study support the hypothesis that oral mucosal LCs are also the target of HIV infection. Cytopathic changes of LCs caused by productive HIV infection may contribute to selective depletion of LCs, which may impair the mucosal immunologic protection against colonization by microorganisms causing HIV‐associated oral mucosal lesions.
Co‐expression of interleukin‐1β and tumor necrosis factor α in synovial tissues and synovial fluids of temporomandibular joint with internal derangement: comparision with histological grading of synovial inflammation
Authors: Suzuki Toshikazu , Segami Natsuki , Nishimura Masaaki , Nojima Takayuki
Published: March 2003

Background:  It has been clarified that interleukin‐1 (IL‐1)β and tumor necrosis factor (TNF)α play an important role in pathogenesis of various joint disease. The purpose of this study was to investigate the cellular source of IL‐1β and TNFα in temporomandibular joint (TMJ), and to analyze the relation between the expression of these cytokines and the intensity of TMJ synovial inflammation.

Methods:   We examined 33 synovial biopsy specimens from patients with internal derangement of the TMJ by an immunohistochemical technique using specific antibodies to IL‐1β and TNFα. We also studied 20 synovial fluids from the patients by enzyme‐linked immunosorbent assay method. These data are compared with histological grading of synovial inflammation by Gynther's system.

Results:   Both IL‐1β and TNFα were predominantly localized in the synovial lining cell layer and the blood vessels of synovial biopsy specimens obtained from patients with TMJ internal derangement. A statistically significant correlation was found between the intensity of IL‐1β expression and that of TNFα. Additionally, the intensity of TNFα expression was statistically correlated with histological grading by Gynther's system.

Conclusion:   These results supported that IL‐1β and TNFα may be involved in the occurrence of TMJ internal derangement and that they coordinately play an role in pathogenesis of TMJ internal derangement.
Ameloblastomatoid, central odontogenic fibroma: an epithelium‐rich variant
Authors: Ide Fumio , Sakashita Hideaki , Kusama Kaoru
Published: March 2003

Two cases are presented of a central odontogenic fibroma (OF) in the mandible of a middle‐aged female, which posed considerable difficulty in microscopic diagnosis. These well‐demarcated but non‐encapsulated intraosseous tumors had hybrid features of both OF and ameloblastoma. Their clinical findings are more in keeping with the putative OF rather than ameloblastoma. The present lesions alert pathologists to this unusual type of central OF in order to avoid misdiagnosis.
Effect of home bleaching and smoking on marginal gingival epithelium proliferation: a histologic study in women
Authors: Da Costa Filho Luiz Cesar , Da Costa Carolina Covolo , Sória Marina Lara , Taga Rumio
Published: March 2003

Background:  Animal studies have suggested that home bleaching agents can cause morphological alterations and changes in the proliferative rate of oral epithelium.

Methods:  A bleaching agent containing 10% carbamide peroxide with carbopol was used in 11 women (five smokers and six non‐smokers) during a 5‐week period. Two biopsies were performed, one of them 15 days before the beginning of the home bleaching treatment and the other immediately after the 5‐week bleaching treatment. Two analyses were performed in the histological sections obtained from the biopsies: epithelium morphometry and assessment of the epithelium's proliferative activity by proliferating cell nuclear antigen (PCNA) immunohistochemistry.

Results:  The home bleaching agent increases epithelium thickness and the PCNA index in both smoker and non‐smoker patients.

Conclusion:  Carbamide peroxide (10%) caused an augmentation in the proliferative activity within the basal and parabasal layers of the gingival epithelium, resulting in a change in this tissue's morphometry.
Rising trends in oral cancer mortality in Spain, 1975–94
Authors: Nieto Adoración , Ramos Miguel Ruiz
Published: March 2003

Background: Epidemiological studies have shown that the worldwide incidence and mortality rates for oral cancer have increased considerably over the last decade. This study investigates the Spanish trend in mortality of oral cancer from 1975–94.

Methods: Age‐standardized, truncated, cumulative, age‐specific and potential years of life lost (PYLL) rates were calculated by gender. Poisson regression models allowed the measurement of age and period effects.

Results: Age‐standardized and cumulative mortality rates increased in males, while truncated and PYLL rates doubled. Changes were less marked in females. There were annual increases in oral cancer mortality from 1975–94, of 25% and 9% in males and females, respectively. In males there was an interaction between age and period. There was also an increase in age‐specific mortality rates in males.

Conclusions: Mortality from oral cancer rose substantially in males, with concomitant changes in the age‐distribution pattern of mortality. Increases were less marked in females, with some minor modifications to the age‐distribution pattern of mortality.
Infrequent genetic alterations of the tumor suppressor gene PTEN/MMAC1 in squamous cell carcinoma of the oral cavity
Authors: Mavros A. , Hahn M. , Wieland I. , Koy S. , Koufaki O. N. , Strelocke K. , Koch R. , Haroske G. , Schackert H. K. , Eckelt U.
Published: March 2003

Background: Fifty tumor specimens from primarily untreated patients were analyzed to elucidate the involvement of the tumor suppressor gene PTEN/MMAC1 in the development of oral squamous cell cancer.

Methods: Eight microsatellite markers, spanning 10 cM of genomic DNA located centromeric, telomeric or intragenic of PTEN/MMAC1 were used for loss of heterozygosity (LOH) and breakpoint analysis. The microsatellite panel within or in close proximity (1 cM) to the 10q23.3 locus showed a LOH rate of 12%. Complete sequence analysis of the genes coding region was performed in all 10 cases that exhibited LOH in one of the eight microsatellite markers within or around the PTEN/MMAC1 gene. Comparative multiplex PCR reactions served to screen for homozygous deletions.

Results: There was no association between allelic loss of the gene, overall patient survival and recurrence‐free survival. Sequencing did not reveal any mutation in the coding region of PTEN/MMAC1. Differential PCR analysis failed to detect any homozygous deletion.

Conclusions: We conclude that PTEN/MMAC1 gene alterations do not play a key role in tumorigenesis of oral squamous cell cancers.
Progressive bulbar palsy: a case report diagnosed by lingual symptoms
Authors: Cerero Lapiedra R. , Moreno López L. A. , Esparza Gómez G. C.
Published: March 2003

The aim of this report is to show a case of Progressive Bulbar Palsy (PBP), diagnosed by oral medicine specialists, from oral symptoms of the disease. We have found no more than two published cases of PBP diagnosed by lingual alterations. We have followed the patient for almost four years, which is remarkable considering that the normal survival period for these patients is up to three years. We would like to emphasize the role of general dentists in the diagnosis of systemic conditions based on an oral examination that should include the oro‐facial muscles.
Thermal sensation and pain in oral lichen planus and lichenoid reaction
Authors: Niissalo Sirkku , Hampf Göran , Hietanen Jarkko , Malmström Maria , Solovieva Svetlana , Pertovaara Antti , Konttinen Yrjö T.
Published: March 2003

Background:  Our previous findings in oral lichen planus (OLP) and lichenoid reactions (LR) raised the question whether the histopathological changes observed in sensory and autonomic innervation produce oral sensory disorders.

Methods:  Spontaneous pain was assessed using the Visual Analogue Scale (VAS). Thermal pain thresholds were measured with a contact thermostimulator and mechanical pain thresholds with an electronic algometer.

Results:  Patients with OLP reported a higher intensity of spontaneous pain than LR patients (P = 0.001). Even erosive LRs were relatively painless. No thermal or mechanical hyperalgesia was detected in oral lesions. Highest separate cold pain threshold was measured in lesions affected by intense Candida growth.

Conclusion:  Together with previous histological findings, the present data suggest that increased somatic innervation and sympathetic denervation do not promote clinical pain sensitivity or hyperalgesia in oral mucosa and that these sensory functions are not affected by OLP and LR. Candida growth may function as secondary irritant modulating the pain responses.
Jaw bone remodeling at the invasion front of gingival squamous cell carcinomas
Authors: Ito Masahiro , Izumi Naoya , Cheng Jun , Sakai Hideaki , Shingaki Susumu , Nakajima Tamio , Oda Kimimitsu , Saku Takashi
Published: March 2003

Background:  It is still unknown how jaw bone remodeling occurs at actual invasion sites of oral squamous cell carcinomas. Since there is no other human carcinomas which make a direct invasion of the bone, gingival carcinomas are valuable examples.

Methods:  Twelve surgical specimens of gingival squamous cell carcinoma were examined histopathologically and immunohistochemically for remodeling of bone and its surrounding tissue.

Results:  Three types of bone interfaces with carcinomatous invasion were distinguished. These included areas with bone resorption, smooth bone surface and new bone formation. In the bone‐resorption area, numerous osteoclasts were located along the bone surface, which was surrounded by myxoid stroma. The myxoid stroma was characterized by immunopositivity for heparan sulfate proteoglycan (HSPG), abundant vascularity and macrophagic infiltration. In the bone‐formation area, rows of osteoblasts were aligned on the bone surface. The stroma around osteoblasts was also HSPG‐immunopositive, poor in vascularity but rich in activated fibroblasts. In the smooth‐bone area, the stroma showed an organizing phase of granulation tissue with slender fibroblasts and mature collagen fibers but with less vascularity and inflammatory infiltrates.

Conclusion:  The results indicate that the stromal architecture, especially in terms of its inflammatory cellular, vascular and matrix compositions, is strictly regulated in the timing and site of jaw bone remodeling which is causes by carcinomatous invasion.
Góngoras Soledades. Der barocke Traum von der enzyklopädischen Beherrschung der Welt
Authors: Kluge Sofie
Published: March 2003

Inhaltsangabe.

Unter allen Werken der spanischen Literaturgeschichte ist Góngoras Soledades (1614) das am meisten diskutierte und strittigste. Im ersten Teil dieser Untersuchung werde ich versuchen, seine unmäßig komplizierte Rezeptionshistorie nachzuzeichnen, während der zweite Teil eine Interpretation bietet, die anstrebt, die heterogenen Fäden des ‘gongorinischen Problems’ zu sammeln. Dieses Verfahren repräsentiert die Anschauung, daß die fast 500 Jahre lange Diskussion über die Bedeutung und den Wert der gongorinischen Gedichte weit über die Grenzen des konkreten Textes hinausgeht und ein universales, literaturtheoretisches Problem bildet: die Frage der literarischen Form als Beherrschung eines Objekts dieser oder jener Art. Die Interpretation der Soledades als eine komplizierte Diskussion der menschlichen Beherrschung veranschaulicht meiner Meinung nach die verschiedenen Teile der Rezeption, die zu verschiedenen Zeiten aus verschiedenen Ursachen diesen oder jenen Aspekt hervorgehoben haben, meist reduzierend und selten synthetisierend. Die Implikation ist die, daß die vielen, einander gegenseitig widersprechenden Interpretationen nicht zufällige, oder schlechthin historisch bedingte sind, sondern ihren Ursprung in der eigenen Komplexität oder Konfliktualität der Soledades haben. Ich bin also davon ausgegangen, daß die Diskussion über die gongorinische Form im 17. Jahrhundert ihren Grund in dem ambivalenten Verhältnis der Gedichte selbst zur literarischen Form als Beherrschung habe, und daß diese Ambivalenz im Verhältnis zur Form der Grund des Zwiespalts zwischen Ästhetizismus und Materialismus in der Interpretation des Inhalts der Gedichte im 20. Jahrhundert sei. Die Diskussion der literarischen Form ins Zentrum der Aufmerksamkeit zu stellen bedeutet aber nicht, daß die Gedichte unabhängig von ihrem historischen Kontext gelesen werden. Ganz im Gegenteil soll es mir gerade darum gehen, die besondere Problematisierung der Beherrschung in Soledades als Ausdruck eines historisch bedingten Schismas zwischen der Dämonisierung der menschlichen Beherrschung der Welt durch ein theologisches Weltbild auf der einen Seite, und dem optimistischen und neugierigen Entdeckungs‐Geist der Aufklärung auf der anderen Seite zu verstehen.
Increased Blood Levels of Human S100 in Melanoma Chick Embryo Xenografts’ Circulation
Authors: KUNZI‐RAPP KARIN , KASKEL* PETER , STEINER RUDOLF , UWE PETER RALF , KRÄHN GERTRAUD
Published: March 2003

The chorioallantoic membrane (CAM) of the fertilized egg allows grafting of human melanomas for short‐term investigations and offers the opportunity to investigate the behavior of metastasizing cells and the release of S100β into peripheral blood. Tissue from one primary melanoma as well as cutaneous and subcutaneous metastases of 10 melanoma patients with elevated levels of S100 in the peripheral blood before surgery were transplanted onto the CAM of chick embryos at day 5/6 of development. Grafts were nourished by the host blood supply 2 days after transplantation. Histologically, 3 days after grafting, metastasizing melanoma cells could be found near the vessels of the host membrane, penetrating the endothelial layer and entering the blood system. Growth conditions remained stable for 6 days after transplantation. Blood samples were taken from a larger CAM vessel before collecting the xenografts 5 days after grafting. Measurement of human S100 in peripheral blood was performed in a blinded manner. No negative control showed elevated levels of human S100 protein. Samples deriving from melanoma xenografts contained highly elevated levels of S100 protein in 80% of cases. The data strongly support the concept of graft–host interaction concerning adherence of tumors and extravasation of human melanoma cells.
Keratinocytes Suppress TRP‐1 Expression and Reduce Cell Number of Co‐cultured Melanocytes – Implications For Grafting of Patients with Vitiligo
Authors: PHILLIPS J. , GAWKRODGER D.J. , CADDY C.M. , HEDLEY S. , DAWSON R.A. , SMITH‐THOMAS L. , FREEDLANDER E. , MAC NEIL S.
Published: March 2003

A pilot study for grafting of patients with vitiligo using cultured epithelial autografts containing melanocytes gave disappointing clinical results, with pigmentation achieved in only one out of five patients. Irrespective of the fate of melanocytes grafted back onto the patients, we experienced problems in identifying melanocytes within these well‐integrated keratinocyte sheets. This led us to explore the fate of these cells within these sheets in vitro and to seek to improve their number and function within the sheets. We report that the introduction of a fibroblast feeder layer can improve melanocyte number within melanocyte/keratinocyte co‐cultures initially, but at very high keratinocyte density, there is a marked loss of melanocytes (as detected by staining for S100). Additionally, we found that keratinocytes not only down‐regulate melanocyte number, but also pigmentary function; thus, it was possible to identify melanocytes that were S100 positive but tyrosinase‐related protein‐1 (TRP‐1) negative in confluent well‐integrated keratinocyte sheets. In summary, our data suggest that keratinocytes at high density initially suppress melanocyte pigmentation (as evidenced by a lack of TRP‐1 expression) and then cause a physical loss of melanocytes. The introduction of a fibroblast feeder layer can help maintain melanocyte number while keratinocytes are subconfluent, but fails to oppose the inhibitory influence of the keratinocytes on melanocyte TRP‐1 expression.
Interaction of Melanin with Proteins – The Importance of an Acidic Intramelanosomal pH
Authors: Mani Indu , Sharma Vandana , Tamboli Irfan , Raman Govindarajan
Published: March 2003

Melanin is a highly irregular heteropolymer consisting of monomeric units derived from the enzymatic oxidation of the amino acid tyrosine. The process of melanin formation takes place in specialized acidic organelles (melanosomes) in melanocytes. The process of melanin polymerization requires an alkaline pH in vitro, and therefore, the purpose of an acidic environment in vivo remains a mystery. It is known that melanin is always bound to protein in vivo. It is also seen that polymerization in vitro at an acidic pH necessarily requires the presence of proteins. The effect of various model proteins on melanin synthesis and their interaction with melanin was studied. It was seen that many proteins could increase melanin synthesis at an acidic pH, and that different proteins resulted in the formation of different states of melanin, i.e., a precipitate or a soluble, protein‐bound form. We also present evidence to show that soluble protein‐bound melanin is present in vivo (in B16 cells as well as in B16 melanoma tissue). An acidic pH appeared to be necessary to ensure the formation of a uniform, very high molecular weight melano–protein complex. The interaction between melanin and proteins appears to be largely charge‐dependent as evidenced by zeta potential measurements, and this interaction is also increased in an acidic pH. Thus, it appears that an acidic intramelanosomal pH is essential to ensure maximum interaction between protein and melanin, and also to ensure that all the melanin formed is protein‐bound.
Volume Changes of Individual Melanosomes Measured by Scanning Force Microscopy
Authors: Testorf Martin F. , Roback Kerstin , Lundström Ingemar , Svensson Samuel P.S.
Published: March 2003

Black pigment cells, melanophores, e.g. located in the epidermis and dermis of frogs, are large flat cells having intracellular black pigment granules, called melanosomes. Due to a large size, high optical contrast, and quick response to drugs, melanophores are attractive as biosensors as well as for model studies of intracellular processes; e.g. organelle transport and G‐protein coupled receptors. The geometry of melanosomes from African clawed toad, Xenopus laevis, has been measured using scanning force microscopy (SFM). Three‐dimensional images from SFM were used to measure height, width, and length of the melanosomes (100 from aggregated cells and 100 from dispersed cells). The volumes of melanosomes isolated from aggregated and dispersed melanophores were significantly different (P<0.05, n=200). The average ellipsoidal volume was 0.14±0.01 (aggregated) and 0.17±0.01 μm3 (dispersed), a difference of 18%. The average major diameter was 810±20 and 880±20 nm for aggregated and dispersed melanosomes, respectively. To our knowledge, this is the first time SFM has been used to study melanosomes. This may provide an alternative non‐destructive technique that may be particularly suitable for studying morphological aspects of various melanin granules.