bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal regulation in fluctuating small mammal populations: feedback structure and climate
Authors: Merritt Joseph F. , Lima Mauricio , Bozinovic Francisco
Published: November 2004

We studied fluctuating populations of six small mammal species in the Appalachian Plateau of Pennsylvania, USA for 20 yr. We analyzed the feedback structure of these species using statistical time series models for spring and autumn abundances. All species showed a seasonal density‐dependent structure, and in five of them first‐order feedbacks were dominant in winter and summer. Instead, southern red‐backed voles (Clethrionomys gapperi) showed a different feedback structure during winter and summer. In three species (C. gapperi, Napaeozapus insignis and Peromyscus maniculatus), environmental factors were more important during summer, while the opposite pattern was found in Blarina brevicauda and Tamias striatus. Snowfall influenced positively the winter population growth rates of southern red‐backed voles, white‐footed mice, woodland jumping mice and eastern chipmunks. We found seasonal differences in the effects of the small mammals assemblage on population growth rates of the two Peromyscus species. The common feedback structure between seasons observed in most of the species, particularly among voles and mice, points to a different feedback structure from northern cyclic small mammals. We conclude that a seasonal feedback structure dominated by intra‐ and inter‐specific competitive interactions may be at the basis of the population dynamics of these species.
Effects of intraspecific competition on size variation and reproductive allocation in a clonal plant
Authors: Kleunen Mark van , Fischer Markus , Schmid Bernhard
Published: November 2004

Clonal plants grow in diameter rather than height, and therefore competition among genets is likely to be symmetric and to result in smaller variation in size of genets than in non‐clonal plants. Moreover, clonal plants can reproduce both sexually and vegetatively. We studied the effects of density on the size of rosettes and of clones, variation in the size of rosettes and of clones, and allocation to sexual and vegetative reproduction in the clonal herb Ranunculus reptans. We grew plants from an artificial population of R. reptans in 32 trays at two densities. After four months, differences in density were still apparent, although clones in the low‐density treatment had on average 155% more rosettes and 227% more rooted rosettes than clones in the high‐density treatment. The coefficient of variation of these measures of clone size was 15% and 83% higher, respectively, in the low‐density treatment. This indicates that intraspecific competition among clones of R. reptans is symmetric and increases the effective population size. Rooted rosettes were larger and varied more in size in the low‐density treatment. The relative allocation of the populations to sexual and to vegetative reproduction was 19% and 13% higher, respectively, in the high‐density treatment. Moreover, seeds produced in the high‐density treatment had a 24% higher mass and a 7% higher germination percentage. This suggests that with increasing density, allocation to sexual reproduction increases more than allocation to vegetative reproduction in R. reptans, which corresponds to the response of some other species with a spreading growth form but not of species with a compact growth form. We conclude that intraspecific competition is an important factor in the life‐history evolution of R. reptans because intraspecific competition affects its clonal life‐history traits and may affect evolutionary processes such as genetic drift and selection through its effect on the effective population size.
Results of a food addition experiment in a north‐central Chile small mammal assemblage: evidence for the role of “bottom‐up” factors
Authors: Meserve Peter L. , Milstead W. Bryan , Gutiérrez Julio R.
Published: November 2004

Since 1989, effects of biotic interactions including predation and herbivory have been examined in a replicated experimental study in a north‐central Chilean semiarid thorn scrub community. Strong responses of small mammals and plants to El Niño Southern Oscillations (ENSO) have also been documented suggesting that “bottom‐up” factors related to high rainfall are important. To simulate increased primary productivity effects on small mammals, ad lib rabbit pellet additions were initiated in mid‐1997 on unfenced grids near the experimental complex. Following the 1997 El Niño event with three times normal precipitation, numbers of small mammals during pre‐addition months and the first treatment year were similar on control and food addition grids. During the second year (1998–1999), a period of severe drought, food additions had significant positive effects on numbers of two predominantly herbivorous “core” (resident) species, Octodon degus and Phyllotis darwini, and an omnivorous “quasi‐core” (resident but highly fluctuating) species, Akodon olivaceus; however, all three species declined towards the end of the second treatment year. Two “opportunistic” (temporarily resident) species, Abrothrix longipilis (an insectivore) and Oligoryzomys longicaudatus (a granivore), showed no responses to food additions. An insectivorous marsupial, Thylamys elegans (also a “core species”), had significantly lower numbers on food addition grids. Changes in body weight distributions and proportions of reproductive individuals particularly in O. degus indicate in situ responses. Whereas no differences in residency, numbers of stations visited, and trappability were observed, energy compensation ratios greater than one suggest significant immigration in the second year. Thus, food additions elicited strong responses by herbivorous/omnivorous “core” and “quasi‐core species” whereas they had no effects on “opportunistic species”. These results reinforce the view that “bottom‐up” factors influencing food availability exert prevailing control on numerically important small mammal species by temporarily increasing carrying capacity, and that “top‐down” factors (i.e., biotic interactions) become important when small mammal numbers are at or near their carrying capacity. Spatial dynamics may be important in explaining declines of species populations exhibiting initially positive responses to food additions.
Competition between mutualists: the role of differential flower abscission in yuccas
Authors: Csotonyi Julius T. , Addicott John F.
Published: November 2004

Competition among yucca moths occurs because retention of flowers is resource limited: the more flowers that are visited the lower the probability that a visited flower will become a fruit. However, an unusual mechanism causes asymmetric competition between two species of yucca moths, with the asymmetry being based upon differential retention/abscission of flowers. Flowers containing eggs of yucca moths that oviposit through the carpel wall (=deeps) are more likely to abscise when other flowers on the same plant contain only the eggs of yucca moths that oviposit into the surface of the carpel wall (=shallows). The advantage of shallows over deeps suggests that shallows should be able to invade sites occupied by deeps, and outcompete deeps. However, proportions of deeps and shallows on Yucca kanabensis have been relatively stable for the last 12 years, and shallows have failed to invade sites with only deeps.  We examined four factors that could affect the ability of deeps to coexist with shallows. 1) The competitive advantage of shallows over deeps was greatest on plants with intermediate levels of visitation. With low visitation few pollinated flowers abscised, competition was weak, and the differential success of shallows was weak. With high visitation intra‐ and interspecific competition was strong, but the differential success was low because most flowers received eggs from both deeps and shallows. 2) There was a partial seasonal segregation of deeps and shallows, with deeps emerging earlier than shallows, thereby increasing the probability of some deeps occurring on plants with relatively few shallows. 3) Although independent aggregation of deeps and shallows at the level of plants could promote coexistence by generating plants where deeps encounter few shallows, association of deeps and shallows was positive. 4) Deeps aggregated among flowers within plants much less than did shallows, which decreases the number of flowers with only shallow ovipositions and decreases the opportunity for asymmetric competition.
Does the species/area relationship account for the density/area relationship?
Authors: Nee Sean , Cotgreave Peter
Published: November 2004

The best‐known macroecological generalisation is the species/area relationship: larger areas contain more species. It has also been observed that the estimated densities of individual species is lower when they are censused over a larger area. Let us call this the density/area relationship. Numerous explanations for the density/area relationship have been proposed – including the idea that the relationship is artefactual. One possible explanation is that it is a necessary consequence of the species/area relationship – after all, if a larger area is to contain more species then the average abundance of individual species must decline. We study a data set that allows us to study both relationships simultaneously. We conclude that the density/area relationship observed for the individual species in this study is consistent with the species/area relationship explanation: in other words, the densities of individual species decline, quantitatively, in the manner required to fit more species into communities with larger areas. We conclude that whatever explains the species/area relationship also explains the density/area relationship and discuss, in particular, the habitat heterogeneity hypothesis.
Genetic niche‐hiking: an alternative explanation for the evolution of flammability
Authors: Schwilk Dylan W. , Kerr Benjamin
Published: November 2004

In fire‐prone ecosystems, many plants possess traits that enhance their relative flammability and ecologists have suggested increased flammability could result from natural selection. To date, theoretical models addressing the evolution of flammable characteristics assume that flammable plants realize some direct fitness advantage. In this paper, we explore the idea that enhanced flammability can increase in frequency in a population without any direct fitness benefit to the flammable type. In our model, flammability evolves due to an association between an allele that promotes flammability and alleles at unlinked loci that give high fitness. In analogy to genetic hitchhiking, in which a deleterious allele can invade due to a genetic linkage, we call this process “genetic niche‐hiking,” because the association results from localized niche construction. Specifically, flammable plants sacrifice themselves and their neighbors to produce local fire‐cleared gaps (the constructed niche) in which their offspring are able to continually track an ever‐changing environment. Niche‐hiking requires that mating, dispersal and niche construction all occur locally (i.e. the population is spatially structured), such that offspring are likely to experience the niches their parents construct. Using a spatially‐explicit lattice‐based simulation, we find that increased flammability can evolve despite the “self‐killing” cost of such a trait. Genetic niche‐hiking may also be applicable to the evolution of other traits in spatially structured ecological systems such as plant disease susceptibility and forest tree characteristics that influence gap production.
Lognormality in ecological time series
Authors: Halley John , Inchausti Pablo
Published: November 2004

Among ecologists, it is often believed that population abundance is lognormally distributed. To test this hypothesis, we analysed and compared 544 annual time‐series of population abundance longer than 30 years (n≥30). Using Khamis’ modified KS test we found one‐half of the long‐term datasets were lognormally distributed (p‐value=0.05). Among those deviating from lognormality, the most consistent feature was that the skewness was less than that expected under the lognormal hypothesis, implying a shorter upper tail (i.e. fewer extremely high values) than expected. There was little evidence of systematic extreme heavy‐tail behaviour characteristic of the Lévy‐stable distributions in long (n≥50 years) time series. Both the standard KS test and the Akaike information criterion (AIC) were used to compare a number of alternative distributions for goodness of fit. Distributions symmetric in logarithmic scale (lognormal and log‐sech) were found to fit the data best according to the KS test. However, by the AIC the gamma distribution was most often the best model. Numbers of significant departures from lognormality varied among taxa, with insects having the highest departure from lognormality. There were also trophic differences, with herbivores deviating from lognormality more than carnivores. We found no habitat or geographic dependencies in the incidence of lognormality. The poor fit of the lognormal to real data means that it is not a good substitute for specific population dynamic and distributional information. However, being a superior “universal” descriptor of population abundance than other two‐parameter models, it may be useful in applications where such detailed information is unavailable.
Strong seasonality may attenuate trophic cascades: vertebrate predator exclusion in boreal grassland
Authors: Norrdahl Kai , Klemola Tero , Korpimäki Erkki , Koivula Minna
Published: November 2004

We studied the indirect effects of vertebrate predator exclusion on plant communities in boreal grassland in western Finland to find out whether the removal of the top trophic level would result in a trophic cascade. Predators were excluded from 1996 to 2000 by eight predator‐proof fences (each 0.5 ha) constructed on old fields. Despite a major increase in vole densities, the expected trophic cascade attenuated rapidly so that the indirect effects of predator exclusion were restricted to a few plant species. The cause for the rapid attenuation of the trophic cascade appeared to be strong seasonality, as peak densities of voles were attained at the end of the growing season of vegetation, and vole populations declined before the next growing season so that the herbivory pressure during the growing season remained low or moderate. Accordingly, most plants escaped the heaviest grazing pressure either in time (plants completed their reproduction and withered before winter) or in space (living parts hidden under frozen ground and ice). However, heavy winter herbivory reduced the biomass of available vegetation and killed woody species (willows) at vole peaks, which implies that predator exclusion may have a strong effect on secondary succession. During summer, voles reduced the coverage of only a few preferred food plants (Elymus repens,Phleum pratense,Vicia cracca). Voles also maintained annual and biennial species in the community by creating gaps in the closed vegetation. We conclude that abiotic factors (harsh winter conditions) limited peak numbers of herbivores below a threshold density where herbivores could have caused a community‐level decline in the biomass of herbaceous plants during summer.
Mechanisms of Exocytosis in Insulin‐Secreting B‐Cells and Glucagon‐Secreting A‐Cells
Authors: Barg Sebastian
Published: November 2004

Abstract: In pancreatic B‐ and A‐cells, metabolic stimuli regulate biochemical and electrical processes that culminate in Ca2+‐influx and release of insulin or glucagon, respectively. Like in other (neuro)endocrine cells, Ca2+‐influx triggers the rapid exocytosis of hormone‐containing secretory granules. Only a small fraction of granules (<1% in insulin‐secreting B‐cells) can be released immediately, while the remainder requires translocation to the plasma membrane and further “priming” for release by several ATP‐ and Ca2+‐dependent reactions. Such functional organization may account for systemic features such as the biphasic time course of glucose‐stimulated insulin secretion. Since this release pattern is altered in type‐2 diabetes mellitus, it is conceivable that disturbances in the exocytotic machinery underlie the disease. Here I will review recent data from our laboratory relevant for the understanding of these processes in insulin‐secreting B‐cells and glucagon‐secreting A‐cells and for the identification of novel targets for antidiabetic drug action. Two aspects are discussed in detail: 1) The importance of a tight interaction between L‐type Ca2+‐channels and the exocytotic machinery for efficient secretion; and 2) the role of intragranular acidification for the priming of secretory granules and its regulation by a granular 65‐kDa sulfonylurea‐binding protein.
Highly Enhanced Permeability of Blood‐Brain Barrier Induced by Repeated Administration of Endothelin‐1 in Dogs and Rats
Authors: Narushima Itaru , Kita Taizo , Kubo Kaoru , Yonetani Yukio , Momochi Chikako , Yoshikawa Ichigo , Ohno Norikazu , Nakashima Toshikatsu
Published: November 2004

Abstract: The effects of intracisternal administration of endothelin‐1 on blood‐brain barrier permeability were examined in dogs and rats. Single doses of endothelin‐1 elevated blood‐brain barrier permeability about two times compared with control groups in both species. However, repeated dosing with endothelin‐1 at a 24 hr intervals caused a highly enhanced disruption of blood‐brain barrier permeability in dogs, but not in rats, whereas the repeated administration with a 48 hr interval markedly increased the blood‐brain barrier permeability in both species of animals (dogs: 923%, rats: more than 661%). Moreover, this abnormally enhanced permeability of blood‐brain barrier in dogs was completely blocked by pretreatment with the endothelin ET‐A receptor selective antagonist, S‐0139, administered prior to either the first or second dosing with endothelin‐1. From these results, we conclude that a repeated attack of endothelin‐1 from the adventitial site of brain blood vessels produces a severe disruption of blood‐brain barrier permeability through an endothelin ET‐A receptor‐mediated process.
Identification of dopamine transporter in bovine pineal gland using [3H]GBR 12935
Authors: Govitrapong P. , Vilaipun P. , Ebadi M.
Published: November 2004

Abstract: The mammalian pineal gland contains several neurotransmitters and receptors for amino acids, biogenic amines, and peptides. Some of these, such as D1 and D2 dopamine receptors, have been previously identified and characterized in the bovine pineal gland by our group. As a matter of fact, the density of D1 dopamine receptors in the pineal gland is higher than that of corpus striatum, suggesting that this organ must possess a high affinity dopamine transporter, which has been identified in this study by using [3H]GBR 12935 as a radiological ligand and nomifensine to determine non‐specific binding. The association rate of [3H]GBR 12935 binding to the pineal membrane was examined as a function of time. The binding reached equilibrium within 45 min of incubation at 25°C. The specific binding was reversible and saturable. The dissociation time course of the specific [3H]GBR 12935 binding from the bovine pineal membrane was also studied. A half‐life (t1/2) of 14‐min was obtained. The saturation analysis of the [3H]GBR 12935 binding revealed a dissociation equilibrium constant (Kd) of 6.0 ± 0.9 nm and a receptor density (Bmax) of 6.9 ± 0.3 pmol/mg protein, which were comparable with those values obtained from bovine striatum and frontal cortex. In competitive experiments, the concentrations of drugs required to inhibit 50% of the binding (IC50) were in descending order GBR 12909 > GBR 12935 > trans‐flupenthixol > nomifensine > cis‐flupenthixol > amitriptyline > imipramine > desipramine > dopamine > fluoxetine > fuvoxamine > d‐amphetamine. However, nisoxetine, SCH 23390, norepinephrine, and serotonin were unable to displace [3H]GBR binding. These results show that drugs capable of blocking dopamine transporters were effective in displacing [3H]GBR binding; whereas specific norepinephrine and serotonin transporter inhibitors were less effective or ineffective. In addition, the dopamine transporter is ion‐dependent as sodium increased [3H]GBR binding in a concentration related manner. These results indicate that a high affinity dopamine transporter exists in the bovine pineal, which may exhibit circadian periodicity, and whose physiological functions need to be delineated and characterized in future investigations.
Regional heterogeneity in immunoreactive macrophages/microglia in the rat pineal gland
Authors: Jiang‐Shieh Ya Fen , Wu Ching Hsiang , Chang Min Lin , Shieh Jeng Yung , Wen Chen Yuan
Published: November 2004

Abstract: Using specific macrophage antibodies (OX‐42, OX‐6, ED‐1 and ED‐2), this study examined the distribution of macrophages/microglia in the pineal gland of adult rats. Except for ED‐2, all antibodies labeled distinct subpopulations of macrophages/microglia in the gland; ED‐2 labeling was hardly detectable. The quantitative study showed that the pineal macrophages/microglia (PMM) expressing complement type 3 receptors (OX‐42) were more numerous than those expressing the major histocompatibility complex class II antigen (OX‐6) or unknown cytoplasmic/lysosomal antigens (ED‐1). The PMM were ubiquitous, especially the OX‐42 labeled cells which were distributed from the dorsal to the ventral aspect of the gland. The macrophages/microglia labeled with OX‐6 or ED‐1 were localized mainly in the intermediate portion of the pineal gland. Immunolabeled cells were sparsely distributed in the distal portion of the pineal gland. A notable feature was that the OX‐6 labeled macrophages/microglia showed a proximal–distal gradient in cell density. Another interesting feature was the occurrence of prominent cell aggregations around the larger blood vessels. These cells were mostly round and exhibited different immunoreactivity. Confocal microscopic study with triple immunolabeling further revealed that individual PMM cell possessed two or more different antigens (ED‐1+/OX‐6+, OX‐42+/OX‐6+ or OX‐42+/ED‐1+). Remarkably, a large population co‐expressed ED‐1+/OX‐6+/OX‐42+. The present results show that the expression of immunoreactive molecules in PMM varies in topographical distribution of the cells. It is suggested that this may be linked to their immunoregulatory functions in the gland.
Mechanical properties of the skin: A comparison between two suction cup methods
Authors: Pedersen L. , Hansen B. , Jemec G. B. E.
Published: November 2004

Background/aims: The objective measure of mechanical properties of the skin is relevant to the clinician as well as to the researcher concerned with skin physiology. The lack of standardization among methods used to obtain visco‐elastic data from the skin is however, apparent and represents an obstacle to comparison of the results derived from the various studies concerning the subject.

Methods: The mechanical properties of the ventral forearm were studied in 35 healthy volunteers. The Dermaflex® and the DermaLab® (Both Cortex Technology, Hadsund, Denmark) were compared. The results were analyzed with descriptive statistics and correlations using non‐parametric methods. Measurement accuracy was assessed using coefficient of variation. Sub analysis was made in groups according to gender and age.

Results: The overall correlations between the two methods were moderate (r = 0.383–0.437). A greater coefficient of variation was found in the DermaLab® machine. Significant differences were found between all values of both methods when comparing the mechanical properties of the skin in 30–39 years olds versus the group of 40–58 years olds. No differences were found between the genders.

Conclusions: The results indicate that both methods are useful in the study of the mechanical aspects of the skin, especially for detecting age‐related changes. The Dermaflex® seems to produce more accurate for data. This is thought to be due to the conceptual design differences between the two methods. The methods measure related but not identical values of the mechanical properties of the skin, as reflected by the limited positive correlation between them.
A closed unventilated chamber for the measurement of transepidermal water loss
Authors: Nuutinen Jouni , Alanen Esko , Autio Pekka , Lahtinen Marjo‐Riitta , Harvima Ilkka , Lahtinen Tapani
Published: November 2004

Background/aimsOpen chamber systems for measuring transepidermal water loss (TEWL) have limitations related to ambient and body‐induced airflows near the probe, probe size, measurement sites and angles, and measurement range. The aim of the present investigation was to develop a closed chamber system for the TEWL measurement without significant blocking of normal evaporation through the skin. Additionally, in order to use the evaporimeter to measure evaporation rates through other biological and non‐biological specimens and in the field applications, a small portable, battery‐operated device was a design criteria.

MethodsA closed unventilated chamber (inner volume 2.0 cm3) was constructed. For the skin measurement, the chamber with one side open (open surface area 1.0 cm2) is placed on the skin. The skin application time was investigated at low and high evaporation rates in order to assess the blocking effect of the chamber on normal evaporation. From the rising linear part of the relative humidity (RH) in the chamber the slope was registered. The slope was calibrated into a TEWL value by evaporating water at different temperatures and measuring the water loss of heated samples with a laboratory scale. The closed chamber evaporation technique was compared with a conventional evaporimeter based on an open chamber method (DermaLab®, Cortex Technology, Hadsund, Denmark). The reproducibility of the closed chamber method was measured with the water samples and with volar forearm and palm of the hand in 10 healthy volunteers.

ResultsThe skin application time varied between 7 and 9 s and the linear slope region between 3 and 5 s at the evaporation rates of 3–220 g/m2 h. A correlation coefficient between the TEWL value from the closed chamber measurements and the readings of the laboratory scale was 0.99 (P < 0.001). The reproducibility of the evaporation measurements with the water samples was 4.0% at the evaporation rate of 40 g/m2 h. A correlation coefficient of the TEWL values between the closed chamber and open chamber measurements was 0.99 (P < 0.001) in the range where the response of a conventional evaporimeter was linear (until 120 g/m2 h). With volar forearm and palm of the hand of 10 healthy volunteers the reproducibility of the measurements was 8.0 and 10.1%.

ConclusionThe closed chamber technique solves the drawbacks related to open chamber evaporimeters. Especially, it extends the measurement range to high evaporation rates and TEWL measurements can be performed practically at any anatomical sites and measurement angle. By the use of a closed chamber the disturbance related to external or body‐induced air flows on the measurement can be avoided.
Correlation between stinging, TEWL and capacitance
Authors: Wu Yanyu , Wang Xuemin , Zhou Yutian , Tan Yimei , Chen Deli , Chen Ying , Ye Meili
Published: November 2004

Background/aims: To study the correlation between stinging and skin barrier and to make the lactic acid stinging test much safer.

Methods: The modified lactic acid stinging test with 3% and/or 5% aqueous solution of lactic acid combined with transepidermal water loss (TEWL) and capacitance (CAP) was used. The amount of 50 µL‐test material was applied on test areas, the skin of both sides nasolabial fold of 50 healthy subjects. Subjects assessed stinging basing on a 4‐point scale at 0, 2.5, 5.0 and 8 min TEWL and CAP were measured at baseline and 8 min.

Results: The results show that the tendency of decrease in baseline CAP and increase in baseline TEWL are proportional with the increase of the sum of clinical scores (CSS). In 5% lactic acid test, negative correlation between changing ratio of TEWL (PTEWL) and clinical score at 5 min (CS5 min), and negative correlation between changing ratio of capacitance (PCAP) and CS5 min are registered.

Conclusion: Our data indicate that there is certain relationship between the degree of stinging and the skin barrier. The stinging test method modified by lower concentration aqueous lactic acid and the assessment combined with PTEWL and PCAP is suitable for Chinese to evaluate the skin susceptibility.
Colour histogram analysis for melanoma discrimination in clinical images
Authors: Faziloglu Yunus , Stanley R. Joe , Moss Randy H. , Van Stoecker William , McLean Rob P.
Published: November 2004

Background: Malignant melanoma, the most deadly form of skin cancer, has a good prognosis if treated in the curable early stages. Colour provides critical discriminating information for the diagnosis of malignant melanoma.

Methods: This research introduces a three‐dimensional relative colour histogram analysis technique to identify colours characteristic of melanomas and then applies these ‘melanoma colours’ to differentiate benign skin lesions from melanomas. The relative colour of a skin lesion is determined based on subtracting a representative colour of the surrounding skin from each lesion pixel. A colour mapping for ‘melanoma colours’ is determined using a training set of images. A percent melanoma colour feature, defined as the percentage of the lesion pixels that are melanoma colours, is used for discriminating melanomas from benign lesions. The technique is evaluated using a clinical image data set of 129 malignant melanomas and 129 benign lesions consisting of 40 seborrheic keratoses and 89 nevocellular nevi.

Results: Using the percent melanoma colour feature for discrimination, experimental results yield correct melanoma and benign lesion discrimination rates of 84.3 and 83.0%, respectively.

Conclusions: The results presented in this work suggest that lesion colour in clinical images is strongly related to the presence of melanoma in that lesion. However, colour information should be combined with other information in order to further reduce the false negative and false positive rates.
The “Haptic Finger”– a new device for monitoring skin condition
Authors: Tanaka Mami , Lévêque Jean Luc , Tagami Hachiro , Kikuchi Katsuko , Chonan Seifi
Published: November 2004

Background/aims: Touching the skin is of great importance for the Clinician for assessing roughness, softness, firmness, etc. This type of clinical assessment is very subjective and therefore non‐reproducible from one Clinician to another one or even from time to time for the same Clinician. In order to objectively monitor skin texture, we developed a new sensor, placed directly on the Clinician's finger, which generate some electric signal when slid over the skin surface.

Material and methods: The base of this Haptic Finger sensor is a thin stainless steel plate on which sponge rubber, PVDF foil, acetate film and gauze are layered. The signal generated by the sensor was filtered and digitally stored before processing. In a first in vitro experiment, the sensor was moved over different skin models (sponge rubber covered by silicon rubber) of varying hardness and roughness. These experiments allowed the definition of two parameters characterizing textures. The first parameter is variance of the signal processed using wavelet analysis, representing an index of roughness. The second parameter is dispersion of the power spectrum density in the frequency domain, corresponding to hardness. To validate these parameters, the Haptic Finger was used to scan skin surfaces of 30 people, 14 of whom displayed a skin disorder: xerosis (n = 5), atopic dermatitis (n = 7), and psoriasis (n = 2).

Results and conclusion: The results obtained by means of the sensor were compared with subjective, clinical evaluations by a Clinician who scored both roughness and hardness of the skin. Good agreement was observed between clinical assessment of the skin and the two parameters generated using the Haptic Finger. Use of this sensor could prove extremely valuable in cosmetic research where skin surface texture (in terms of tactile properties) is difficult to measure.
A quantitative electromyographic analysis of masticatory muscle activity in usual daily life
Authors: Saifuddin Md , Miyamoto K , Ueda HM , Shikata N , Tanne K
Published: November 2004

OBJECTIVE: This study was designed to investigate whether a quantitative electromyographic (EMG) analysis with a special reference to the EMG amplitude at 98N bite force could reduce the influence of electrode relocation and to examine the reproducibility of masticatory muscle activity in usual daily life within individuals.

SUBJECTS AND METHODS: In the first experiment, two sessions of surface EMG recording for masseter and anterior temporal muscles during tapping, and chewing gum and marshmallow were performed for 10 subjects with an interval of at least 1 week with electrode relocation. In the second experiment, two sessions of EMG recording during daytime (142 min, including mealtime) and sleep (142 min) were carried out for 10 subjects with an interval of at least 1 week. The average rectified EMG values were normalised with a special reference to the EMG amplitude induced by a 98N bite force.

RESULTS: In the first experiment, high correlation coefficients and no significant differences in the mean normalised values of muscle activity were found between two sessions. Although the average rectified values showed high correlation coefficients, the mean masseter muscle activity while chewing gum was significantly different between two sessions. In addition, the variation in temporal muscle activity between two sessions while chewing gum was significantly smaller in the normalised values than in the average rectified ones. In the second experiment, less intra‐individual variation in the normalised values of masticatory muscle activity between two sessions indicated the reproducibility. Normalised masticatory muscle activity showed less variation during mealtimes than during usual daytime and sleep.

CONCLUSIONS: This quantitative EMG analysis could estimate the masticatory muscle activity by reducing the influences of electrode relocation, demonstrating an availability of this analysis for the evaluation of masticatory muscle activity in usual daily life.
A case of elongated pterygoid hamulus syndrome
Authors: Sasaki T , Imai, Y , Fujibayashi T
Published: November 2004

Elongation of the pterygoid hamulus is a rare syndrome that shows various and complex symptoms in the palatal and pharyngeal region. A case of elongated pterygoid hamulus syndrome in a 47‐year old man is reported here.
Orofacial effects of antiretroviral therapies
Authors: Scully C , Diz Dios P
Published: November 2004

This paper summarises some of the oral adverse effects of antiretroviral agents. Some are related to bone marrow suppression which may also predispose to mouth ulcers. Erythema multiforme and toxic epidermal necrolysis are especially well recognized in HIV disease, particularly as reactions to sulphonamides and to antiretroviral agents. Oral lichenoid reactions have been described in HIV disease often relating to zidovudine use. Didanosine has also produced erythema multiforme and not unusually induces xerostomia, again by an unknown mechanism. Xerostomia may be seen in up to one‐third of patients taking didanosine. Taste abnormalities are common with the protease inhibitors and oral and perioral paraesthesia can be a disturbing adverse effect. Ritonavir in particular can give rise to circumoral paraesthesia in over 25% of patients. Indinavir can also produce cheilitis.
Oligodontia is associated with extra‐oral ectodermal symptoms and low whole salivary flow rates
Authors: Nordgarden H , Jensen JL , Storhaug K
Published: November 2004

INTRODUCTION: Ectodermal dysplasias (EDs) involve abnormal development of hair, teeth, nails, and sweat glands.

OBJECTIVES: (1) To investigate the frequency of extra‐oral ectodermal symptoms in persons with oligodontia (>6 congenitally missing teeth). (2) To examine whole salivary flow rates in oligodontia patients, with special emphasis on persons with EDs.

SURVEY GROUP AND METHODS: Sixty‐eight persons with oligodontia and 39 healthy control persons were included. All participants underwent an interview, general and oral examinations, and whole salivary secretory tests.

RESULTS: Thirty‐nine (57%) of the oligodontia patients had disturbances in either hair, nails and/or sweat production in addition to teeth and were classified as the ED group. The remaining 29 oligodontia patients had no obvious signs of EDs (non‐ED group). The prevalences of dry skin, asthma and eczema were higher, and whole salivary secretory rates lower, in the ED group as compared to the control group. Intermediate values were observed in the non‐ED group. Incisors, canines and molars were more frequently missing in the ED group than in the non‐ED group, whereas no differences were observed in the frequency of missing premolars. Negative correlations between the number of missing teeth and unstimulated and chewing stimulated whole salivary secretory rates were found.
Mast cell degranulation and the role of T cell RANTES in oral lichen planus
Authors: Zhao ZZ , Sugerman PB , Zhou XJ , Walsh LJ , Savage NW
Published: November 2004

OBJECTIVES: The present study investigated mast cell degranulation in oral lichen planus (OLP) and the effect of OLP lesional T cell supernatants on mast cell degranulation.

MATERIALS AND METHODS: Immunohistochemistry was used to identify mast cell degranulation in both OLP (n= 22) and normal control (n= 14) tissues. OLP lesional T cell lines (n= 5) and HMC‐1 (a human leukemia mast cell line) were used to examine the effects of OLP T cell supernatants on mast cell degranulation in vitro.

RESULTS: Approximately 60% of mast cells were degranulated in OLP. OLP lesional T cells expressed mRNA for RANTES, and TNF‐α stimulation upregulated OLP lesional T cell RANTES secretion. OLP lesional T cell supernatants induced degranulation of HMC‐1 with release of TNF‐α and histamine. Human recombinant RANTES similarly induced mast cell degranulation. Anti‐RANTES antibody blocked OLP lesional T cell supernatant‐ induced mast cell degranulation.

CONCLUSIONS: This study is the first to show that OLP lesional T cells produce and secrete RANTES which triggers human mast cell degranulation. Degranulating mast cells release TNF‐α which upregulates OLP lesional T cell RANTES secretion. Such a cyclical mechanism may underlie disease chronicity and future therapies may include blocking RANTES or TNF‐α activity in OLP.
Implantation of octacalcium phosphate nucleates isolated bone formation in rat skull defects
Authors: Kamakura S , Sasano Y , Homma H , Suzuki O , Kagayama M , Motegi1 K
Published: November 2004

OBJECTIVE: Our previous radiographic examinations have indicated that the synthetic octacalcium phosphate (OCP) may provide the core for nucleating multiple osteogenic sites in the experimentally created cranial defect.

DESIGN: The present study was designed to confirm the possibility that the implanted OCP causes the osteoinduction as well as the osteoconduction in the rat cranial defect.

MATERIALS AND METHODS: Standardized defects were created in male Wistar rat calvaria, and the OCP granules were implanted into the defect. The sham operated rats were processed in the same way except that nothing was implanted. The rats were fixed at 4 weeks after implantation of OCP or the sham operation. We examined bone formed on the implanted OCP, analyzing serial sections histologically combined with immunohis‐tochemistry for the bone specific protein, osteocalcin.

RESULTS: In the defects treated with OCP, the radiopacity was scattered throughout the defect besides being observed along the defect margin of the parietal bone. Examination of the serial sections showed that some of new bones on the implanted OCP were formed away from the defect margin of the parietal bone with regard to both histological identification and specific molecular marker.

CONCLUSIONS: The present study suggested that the implanted OCP can serve as a core for initiating bone formation and cause the osteoinduction as well as the osteoconduction in the defect.
Post‐harvest fungal quality of selected chewing sticks
Authors: Etebu E , Tasie AA , Daniel‐Kalio LA
Published: November 2004

OBJECTIVE:  To study post‐harvest fungal overgrowth on chewing sticks used for oral hygiene measures and role of disinfection.

METHODS:
 The post‐harvest fungal spoilage of chewing sticks (

Garcinia kola
,
Glyphea brevis
and
Azadirachta indica ) was investigated by subjecting the chewing sticks to different preparatory methods (some disinfected in 0.7% sodium hypochlorite before storage), storage conditions (unsealed or sealed in clear polythene) and different storage periods (2, 3 and 4 weeks).

RESULTS:
 Significant differences (
P
 = 0.05) in mean percentage fungal colonization were dependent on plant type and storage period, but not on preparative methods and storage conditions. There were, however, significant interactions between chewing sticks and preparative methods, storage conditions and storage periods, respectively.
Azadirachta indica
was observed to be more susceptible to post‐harvest spoilage organisms than other test plants. Generally, percentage fungal colonization increased with increase in storage period. Four genera,
Penicillium
spp.,
Aspergillus
spp.,
Mucor
spp. and
Botryodiplodia spp., were implicated with post‐harvest colonization of chewing sticks after 4 weeks of storage.

CONCLUSION:  The use of harvested chewing sticks after prolonged storage period is therefore not advisable for oral hygiene measures.
Parotid gland involvement in advanced AIDS
Authors: Vargas PA , Mauad T , Böhm GM , Saldiva PHN , Almeida OP
Published: November 2004

OBJECTIVE:  This study describes the involvement and the histological alterations found in the parotid glands of 100 patients who died with AIDS.

MATERIALS AND METHODS:  Sex, age, CD4 cell count and clinical history were obtained from the files of 100 patients who died with AIDS. Histological analysis of the parotid glands was performed using H&E, Gomori–Grocott, Ziehl–Neelsen and Mucicarmine. Histological findings were grouped in reactive, infectious, cystic, neoplastic and concomitant lesions.

RESULTS:
 None of the patients presented complaints or symptoms related to salivary gland alterations prior to death. The mean age of the patients and CD4 cell count were 36.4 years and 76.07 cells μl
−1 , respectively. Histological alterations of the parotid glands were found in 51% of the patients. The most common alteration was non‐specific chronic sialadenitis (29 cases), followed by infectious conditions (22 cases). Mycobacteriosis was the most common infectious disease (10 cases), followed by cytomegalovirus (nine cases), cryptococcosis (three cases) and histoplasmosis (two cases). Lymphoepithelial cysts occurred in six cases, Warthin's tumor and non‐Hodgkin Lymphoma in one case each.

CONCLUSIONS:  These results indicate that infection and other lesions in the parotid glands are more frequent than hitherto described in the specialized literature in AIDS patients. Clinicians should consider parotid gland involvement, when evaluating disease extension in advanced AIDS patients.
Differential distribution of glycosaminoglycans in human cementifying fibroma and fibro‐osseous lesions
Authors: Endo Y , Uzawa K , Mochida Y , Nakatsuru M , Shiiba M , Yokoe H , Yamauchi M , Tanzawa H
Published: November 2004

OBJECTIVE:  Differential diagnosis of cementifying fibroma, ossifying fibroma and fibrous dysplasia by histological evaluation is often difficult. The aim of this study was to examine the immunoreactivities for keratan sulfate (KS) and chondroitin‐4‐sulfate (C4S) glycosaminoglycans of the histological samples obtained from mandibles of patients with these diseases.

MATERIALS AND METHODS:  The samples were collected from three patients with cementifying fibroma, two with ossifying fibroma and three with fibrous dysplasia and were subjected to immunohistochemical analyses.

RESULTS:  The results demonstrated that a significant immunoreactivity for KS was found in lacunae housing cells in the cementum‐particles of cementifying fibromas, while both ossifying fibromas and fibrous dysplasias showed no significant immunoreactivity for KS. For C4S, while the former showed little immunoreactivity, the latter two cases exhibited intensive immunostaining in the pre‐ and poorly mineralized matrices.

CONCLUSIONS:  These results suggest that cementifying fibromas could be distinguished from these fibro‐osseous tumors by using immunohistochemical analysis for KS and C4S.
Inhibitory effect of titanium particles on osteoclast formation generated by treatment of mouse bone marrow cells with PGE2
Authors: Nakano M , Tsuboi T , Kato M , Kurita K , Togari A
Published: November 2004

OBJECTIVE:  The present study was designed to evaluate the effect of titanium (Ti) particles with no endotoxin on osteoclast differentiation and osteoclast activity in in vitro experiments.

METHODS:  Osteoclast formation as well as osteoclastic bone resorbing activity were examined using the mouse bone marrow culture system and purified rabbit osteoclasts treated with Ti particles (2.5–20 μg cm−2).

RESULTS:  Ti particles, with no adherent endotoxin, inhibited osteoclastogenesis and receptor activator of NF‐κB ligand (RANKL) expression in bone marrow cells treated with prostaglandin E2 (PGE2) (100 nM). The inhibitory effect of Ti particles was concentration‐dependent (5–20 μg cm−2), and was observed only on the generation of osteoclasts by PGE2, but not by 1,25‐dihydroxyvitamin D3 or soluble RANKL. This suggests that Ti particles did not act uniformly on a common process in the generation of osteoclasts, but specifically on signal transduction for PGE2 in generating osteoclasts. In highly purified osteoclasts, Ti particles showed no effect on survival and bone resorbing activity.

CONCLUSION:  Ti particles inhibited osteoclast differentiation and RANKL expression in mouse bone marrow cells treated with PGE2, without affecting mature osteoclast survival or activity. Thus, Ti particles may alter the osteoclastogenetic action of PGE2, which is one of the regulatory factors of bone remodeling.
Relating model parameters to basic soil properties
Authors: Merdun Hasan , Quisenberry Virgil L.
Published: November 2004

Relating model parameters to basic soil characteristics can help to differentiate and classify soils based on their flow and transport characteristics and ultimately helps to develop a sound management tool to protect groundwater from industrial and agricultural contaminants. In this study, the model parameters (effective diffusion path-length or aggregate half-width, boundary soil water pressure, boundary hydraulic conductivity, saturated hydraulic conductivity, tortuosity in macropores, dispersivity, mixing depth) obtained from simulation of water flow and solute transport for 3 soils (Maury, Cecil, Lakeland) with contrasting properties were related to see whether these derived parameters can be related to variation in fundamental soil properties such as texture and structure and thus the flow and transport characteristics of the soils. The boundary is a division point in which the soil porosity is divided into macropores and micropores. The ANOVA test showed that the parameter values of effective diffusion path-length and tortuosity in macropores for 3 soils were not different from each other, but the parameter values of saturated and boundary hydraulic conductivities including the texture (clay content) were statistically different. Moreover, the means of boundary soil water pressure, dispersivity, and mixing depth for 3 soils were significantly different. These results suggest that relating model parameters to basic soil properties in order to differentiate and classify soils based on their flow and transport characteristics is promising and needs further study.