bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene dispersal and outbreeding in a philopatric mammal
Authors: Winters Jonathan B. , Waser Peter M.
Published: July 2003

Extensive mark–recapture data from banner‐tailed kangaroo rats,Dipodomys spectabilis, have shown that both males and females are highly philopatric and suggest the possibility of close inbreeding. However, indirect analyses based on genetic structure appear to contradict direct observations, suggesting longer dispersal distances. Using microsatellite genotypes from most members of a banner‐tailed kangaroo rat population during five successive breeding seasons, we ask how relatedness is influenced by dispersal and how it in turn influences mating patterns. The data confirm that, because of philopatry, neighbours are often close relatives. However, patterns of parentage also show that the average distance between mates is large relative to natal dispersal distances and larger than the average distance between nearest opposite‐sexed neighbours. Females’ mates were often not their nearest male neighbour and many were less related than the nearest male neighbour. We detected multiple paternity in some females’ litters; both sexes produce offspring with multiple mates within and between breeding seasons. At the population level, heterozygosities were high and estimates ofFwere low, indicating that levels of inbreeding were low. Using individual inbreeding coefficients of all juveniles to estimate their parents’ relatedness, we found that parental relatedness was significantly lower than relatedness between nearest opposite‐sexed adult neighbours. Thus in philopatric populations, long breeding forays can cause genes to move further than individuals disperse, and polyandry may serve to reduce relatedness between mates.
Inferences from mitochondrial DNA patterns on the domestication history of alfalfa (Medicago sativa)
Authors: Muller M. H. , Prosperi J. M. , Santoni S. , Ronfort J.
Published: July 2003

The evolutionary history of a wild–cultivated complex is the outcome of different factors, among which are the domestication of the cultivated form, its geographical and demographic expansion, as well as gene flow between natural and cultivated populations. To clarify this history for alfalfa (Medicago sativa), we adopted a phylogeographical approach based on a sample of natural and cultivated populations of the M. sativa species complex. This sample was characterized for mtDNA variation through restriction fragment length polymorphisms. Twenty‐two mitotypes were identified in the whole data set (155 individuals). In the wild pool from the presumed area of origin (Near East to Central Asia), the diversity was high but the absence of geographical differentiation hinders a more precise location of the centre of domestication. Within the cultivated alfalfa, the geographical structure suggests strongly the existence of at least two independent routes of dissemination of alfalfa from its centre of origin. In particular, original mitotypes detected in some regions suggest that wild populations not sampled in this study, and located outside the presumed area of domestication, may have contributed to the diversity of the cultivated pool. Finally, analysis of the mtDNA variation shows that natural populations collected in Spain constitute an endemic wild pool now introgressed partially by cultivated alfalfa.
Genetic structure and gene flow in a metapopulation of an endangered plant species,Silene tatarica
Authors: Tero N. , Aspi J. , Siikamäki P. , Jäkäläniemi A. , Tuomi J.
Published: July 2003

We investigated the distribution of genetic variation within and between seven subpopulations in a riparian population ofSilene tataricain northern Finland by using amplified fragment length polymorphism (AFLP) markers. A Bayesian approach‐based clustering program indicated that the marker data contained not only one panmictic population, but consisted of seven clusters, and that each original sample site seems to consist of a distinct subpopulation. A coalescent‐based simulation approach shows recurrent gene flow between subpopulations. Relative highFSTvalues indicated a clear subpopulation differentiation. However,amovaanalysis and UPGMA‐dendrogram did not suggest any hierarchical regional structuring among the subpopulations. There was no correlation between geographical and genetic distances among the subpopulations, nor any correlation between the subpopulation census size and amount of genetic variation. Estimates of gene flow suggested a low level of gene flow between the subpopulations, and the assignment tests proposed a few long‐distance bidirectional dispersal events between the subpopulations. No apparent difference was found in within‐subpopulation genetic diversity among upper, middle and lower regions along the river. Relative high amounts of linkage disequilibrium at subpopulation level indicated recent population bottlenecks or admixture, and at metapopulation levels a high subpopulation turnover rate. The overall pattern of genetic variation within and between subpopulations also suggested a ‘classical’ metapopulation structure of the species suggested by the ecological surveys.
Phylogeography of the rock partridge (Alectoris graeca)
Authors: Randi E. , Tabarroni C. , Rimondi S. , Lucchini V. , Sfougaris A.
Published: July 2003

We used mitochondrial DNA control‐region and microsatellite data to infer the evolutionary history and past demographic changes in 332 rock partridges (Alectoris graeca) sampled from throughout the species’ distribution range, with the exception of the central Balkans region. Maternal and biparental DNA markers indicated concordantly that rock partridge populations are structured geographically (mtDNA φST = 0.86, microsatelliteFST = 0.35;RST = 0.31;P < 0.001). Phylogenetic analyses of 22 mtDNA haplotypes identified two major phylogroups (supported by bootstrap values = 93%), splitting partridges from Sicily vs. all the other sampled populations at an average Tamura–Nei genetic distance of 0.035, which corresponds to 65% of the average distance between closely related species ofAlectoris. Coalescent estimates of divergence times suggested that rock partridges in Sicily were isolated for more than 200 000 years. This deep subdivision was confirmed by multivariate, Bayesian clustering and population assignment analyses of microsatellite genotypes, which supported also a subdivision of partridges from the Alps vs. populations in the Apennines, Albania and Greece. Partridges in the Apennines and Albania–Greece were probably connected by gene flow since recently through a late Pleistocene Adriatic landbridge. Deglaciated Alps were probably colonized by distinct and, perhaps, not yet sampled source populations. Bottleneck and mismatch analyses indicate that rock partridges have lost variability through past population declines, and did not expand recently. Deglaciated areas could have been recolonized without any strong demographic expansion. Genetic data partially supported subspecies subdivisions, and allowed delimiting distinct conservation units. Rock partridges in Sicily, formally recognized asA. g. whitakeri, met the criteria for a distinct evolutionary significant unit.
Erfolgreiche Reduktion des SCORAD‐Scores bei Kindern mit atopischem Ekzem im 6‐Wochen‐Vergleich durch Kurzschulung mit einem vereinfachten Hautmodell
Authors: Kardorff Bernd , Schnelle‐Parker Gisela , Kardorff Maria , Wahlen Manuela , d'Orville Inga Hönig , Dorittke Peter
Published: July 2003

Hintergund: Zur langfristigen Stabilisierung des Hautbefundes bei Patienten mit atopischem Ekzem ist die konsequente Durchführung einer Hautpflege essentiell. Im Rahmen der ambulanten dermatologischen Sprechstunde bleibt häufig zu wenig Zeit für eine intensive Aufklärung der Patienten. Zur Evaluation der Effektivität einer kurzen, aber eindrucksvollen praktischen Hautpflegeschulung mit dem „Hautmodell nach Kardorff, Schnelle‐Parker” während der normalen Sprechstunde führten wir eine randomisierte prospektive Vergleichsstudie durch.

Patienten und Methodik: 30 konsekutiv in unserer Praxis als Patienten vorstellig gewordene Kinder zwischen 3 und 6 Jahren mit mittelschwerem atopischem Ekzem wurden eingeschlossen. Die Hälfte der Patienten erhielt an den Tagen 0 und 14 eine aktive Kurzzeitschulung von 10 Minuten mit dem Hautmodell, die Kontrollgruppe erhielt in der selben Zeit intensive verbale Erklärungen wie bei einer dermatologischen Routinebehandlung. Der SCORAD‐Score wurde an den Tagen 0, 14 und 42 blind ermittelt.

Ergebnisse: Nach 42 Tagen hatte die mit dem „Hautmodell nach Kardorff, Schnelle‐Parker” geschulte Gruppe einen signifikant geringeren SCORAD‐Score als die Kontrollgruppe (p < 0,006).

Schlußfolgerungen: Durch die auch für Vorschulkinder einleuchtende, den Tastsinn einbeziehende Schulung mit dem Hautmodell wird eine bessere Compliance in Bezug auf regelmäßige Hautpflege erzielt. Hierdurch werden positive Effekte für das langfristige Erkrankungsmanagement des atopischen Ekzems erwartet.
Benefit of migration in a female sika deer population in eastern Hokkaido, Japan
Authors: SAKURAGI MAYUMI , IGOTA HIROMASA , UNO HIROYUKI , KAJI KOICHI , KANEKO MASAMI , AKAMATSU RIKA , MAEKAWA KOJI
Published: July 2003

The major factors affecting migration in large herbivores have been shown to be access to food resources and the risk of predation. Three migratory types of deer (resident, north migrant and east migrant) occur within a wintering female sika deer (Cervus nippon) population in eastern Hokkaido, Japan. We tested the hypothesis that north and east migrants feed on a higher quality diet than residents during summer, based on analyses of fecal nitrogen content. Fresh fecal pellets were collected in 18 summer ranges in the wintering area, northern area and eastern area between 1–5 August 2000. Fecal nitrogen content for all sampling sites was positively correlated with elevation, but was not correlated with distance from the wintering area. North migrants that inhabited higher (above 300 m elevation) summer ranges fed on a higher quality diet than residents. In contrast, the dietary quality of east migrants that migrated over a long distance and inhabited lower (below 300 m elevation) summer ranges was similar to that of residents. We conclude that east migrants may have gained significant benefit from the use of agricultural pastures with low population density conditions and without hunting; however, the recent population control program has reduced this benefit by avoiding the use of pasturelands.
Seasonal change in browsing by sika deer on hinoki cypress trees on Mount Takahara, central Japan
Authors: UEDA HIRONORI , TAKATSUKI SEIKI , TAKAHASHI YASUNORI
Published: July 2003

Browsing by sika deer (Cervus nippon Temminck) on hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) was monitored for approximately 3 years on 300 trees at three sites on Mount Takahara, central Japan. We investigated the seasonal change in browsing on hinoki cypress in relation to the availability of other food plants (dominated by Sasa nipponica Makino et Shibata) and preferred food plants (deciduous broad leaves). Browsing occurred mostly from November to April, while no browsing damage occurred from June to October. Browsing was observed in November, even when the amount of other food plants did not decrease. Therefore, the cause of browsing cannot be fully explained by a decreased availability of other food plants. Comparison of fecal composition and food availability showed that deer had a preference for deciduous broad leaves. The availability of these preferred plants decreased in November and increased in May. Chemical analysis of the hinoki cypress and deciduous broad leaves (crude protein and neutral detergent fiber) showed that the quality of deciduous broad leaves decreased in November, and as a result the quality of hinoki became higher than that of the deciduous broad leaves. Browsing on hinoki cypress occurred when the availability of deciduous broad leaves decreased, and vice versa. These results suggest that the availability of preferred food plants influences browsing on hinoki cypress by sika deer.
Multiscale patterns of spatial variation in stream macroinvertebrate communities
Authors: BOYERO LUZ
Published: July 2003

Our ability to detect patterns of variation of communities depends on the spatial scale of observation. I examined the spatial variation of macroinvertebrate community structure: abundance, richness, evenness, percentage of Ephemeroptera, Plecoptera and Trichoptera (EPT), and taxonomic composition across a wide range of spatial scales in two mountain streams. In a nested design, three segments were selected within each basin, three riffles within each segment, three sections within each riffle, and three samples within each section. Significant variation of communities occurred mainly at sample and riffle scales, although different community characteristics may vary at different scales. Environmental factors were strongly related to communities, but these relationships depended on spatial scale in many cases, suggesting that the influence of the environment is ultimately regulated by the grain and extent of organisms. This study highlights the importance of multiscale studies to obtain a complete understanding of the spatial variation of macroinvertebrate communities and their relationship with the environment.
Effects of aquatic macrophytes on water quality and phytoplankton communities in shallow lakes
Authors: TAKAMURA NORIKO , KADONO YASURO , FUKUSHIMA MICHIO , NAKAGAWA MEGUMI , KIM BAIK‐H. O.
Published: July 2003

We investigated aquatic macrophytes, water quality, and phytoplankton biomass and species composition in three shallow lakes with different levels of vegetation cover and nutrient concentration in Kushiro Moor, during August 2000. Trapa japonica can live in a wide range of nutrient levels. This species forms an environment with a steeper extinction of light, higher concentrations of dissolved organic carbon (DOC), lower concentrations of dissolved oxygen (DO) near the bottom, and lower concentrations of nitrate + nitrite and soluble reactive phosphorus (SRP) than other vegetation types. The pH was much higher in a Polygonum amphibium community, and the DO near the bottom did not decrease compared to a T. japonica community in the summer. The relationship between chlorophyll a and the limiting nutrient (total phosphorus (TP) when total nitrogen (TN) : TP is ≥10 and TN/10 when TN : TP is <10) significantly differed between lakes with and without submerged vegetation. The chlorophyll a concentrations at a given nutrient level were significantly lower in water with submerged macrophytes than in water without them. Correspondence analysis showed that the difference in phytoplankton community structure across sites was largely due to the presence or absence of submerged macrophytes, and the ordination of phytoplankton species in the lakes with submerged macrophytes is best explained by environmental gradients of TN, chlorophyll, pH and SRP.
Diversity–productivity–stability relationship in freshwater ecosystems: Whole‐systemic view of all trophic levels
Authors: AOKI ICHIRO
Published: July 2003

The idea of the diversity–productivity relationship in ecology was originated by Charles Darwin more than 100 years ago and was highlighted by McNaughton in 1993. There have been extensive studies on this relationship, mostly conducted in grasslands. Many studies assert that a high level of biodiversity leads to high primary productivity, in accord with Darwin. However, these studies have mostly been done in grasslands (primary producer) and do not take into account effects from other trophic levels. The possibility remains that the positive diversity–production relationship does not hold in other types of ecological systems and that multitrophic effects influence and modify the relationship. In the present study, the diversity–productivity relationship is examined for freshwater foodwebs, including whole trophic compartments, by using indices of diversity and productivity more suitable for a whole systemic study on ecological systems. It seems that there are two trends in the relationship: productivity increases with the increase of diversity in ecosystems when diversity is small, and decreases with diversity in ecosystems when diversity is large. The first trend may be due to nutrient‐limiting characteristics and the second trend may be due to photosynthetically active radiation–limiting characteristics. Also, both higher trophic and whole‐systemic productivities are found to increase relative to primary productivity with the increase of diversity. Stability indices introduced previously, combined with the present results, reveal a positive correlation between relative productivity and stability in freshwater foodwebs, including all trophic compartments.
Components of spatial patterning in a serpentine grassland
Authors: OVERTON JACOB McC. , LEVIN SIMON A.
Published: July 2003

We analyzed the components of spatial patterning in species abundance in a diverse grassland dominated by early season, annual forbs. Species abundance, soil depth and gopher disturbances were measured by means of a nested spatial design on two 8 m × 20 m plots that differed in the amount of larger scale variability in soil depth. Species distributions at the scale of the 10 cm × 10 cm quadrat were highly clumped, with a decline in clumping with mean abundance. Even with the effect of abundance on clumping removed, species showed differences in the degree of clumping and these differences were consistent between the two plots. The abundance of the species and the frequency of disturbance correlated weakly to moderately with soil depth. Semivariance analyses indicated that the most common species all showed complex spatial patterning at a range of scales. Some of this variation corresponded to patterns of soil depth variation and patterns of gopher disturbance; however, a large amount of the spatial patterning in species abundance remains unexplained.
Macronutrient input from pollen in two regenerating pine stands in southeast Korea
Authors: LEE EUN JU , BOOTH THOMAS
Published: July 2003

This study examined macronutrient input from pollen in two naturally regenerating pine stands in southeast Korea. Durham gravity pollen collectors were used to measure pine pollen deposition and the macronutrients in the collected pine pollen were analyzed. In 1998, pine pollen deposition began just before 18 April and lasted for approximately 2 weeks. Total pine pollen deposition differed between the two sampling sites; 27.5 kg ha−1 was collected from the mature stand and 17.7 kg ha−1 was collected from the young stand. The values for nutrient deposition from pine pollen are 549 g ha−1 N, 78 g ha−1 P, 240 g ha−1 K, 45 g ha−1 S and 22 g ha−1 Mg at the mature stand and 353 g ha−1 N, 51 g ha−1 P, 151 g ha−1 K, 27 g ha−1 S and 14 g ha−1 Mg at the young stand, suggesting that nutrients from pine pollen contribute to forest nutrient cycling. The pine pollen deposition values obtained from our study (17.7–27.5 kg−1 ha−1 year−1) are approximately 1/115–180‐fold that of pine litterfall in Korea. If we take pollen nutrients into account, the contribution rate of pollen to the annual nutrient input is very high in our study (N 1/30, P 1/5, K 1/9 that of litterfall). Macronutrient deposition from pine pollen is concentrated temporally in spring. Although the annual contribution of nutrient mass by pollen is small compared to that of litterfall, the rapid turnover rate of pollen nutrients combined with episodic deposition suggests that pollen may play a disproportionate role in temperate pine forest nutrient cycling.
Microbial biomass and abundance after forest fire in pine forests in Japan
Authors: MABUHAY JHONAMIE A. , NAKAGOSHI NOBUKAZU , HORIKOSHI TAKAO
Published: July 2003

Microbial characteristics of soil are being evaluated increasingly as sensitive indicators of soil health because of the clear relationship between microbial diversity, soil and plant quality and ecosystem sustainability. This study aimed to determine microbial carbon biomass and microbial abundance after fire to estimate the degree of damage, including the rate of recovery of micro‐organisms, in each area. The study also aimed to establish relationships between microbial biomass and microbial abundance and the physico‐chemical properties of the soil. The study was conducted in three different study areas in Hiroshima prefecture, one unburned area and two burnt areas (one immediately after and one 2 years after fire). anova showed a significant difference in microbial carbon biomass and microbial abundance among the study areas. Microbial carbon biomass and microbial abundance were highest in the unburned area, followed by the area burnt 2 years ago and lastly by the area studied immediately after fire. Carbon biomass was highly correlated with microbial abundance (r2 = 0.950). Carbon biomass and microbial abundance were shown to be significantly correlated to the soil's physico‐chemical properties, such as pH, moisture content, water‐holding capacity and carbon : nitrogen (C : N) ratio. However, the C : N ratio was closely correlated to both carbon biomass and microbial abundance with r2 = 0.705 (P < 0.01) and r2 = 0.560 (P < 0.01), respectively.
Spatial distribution of canopy and subcanopy species along a sloping topography in a cool‐temperate conifer‐hardwood forest in the snowy region of Japan
Authors: HIRAYAMA KIMIKO , SAKIMOTO MICHINORI
Published: July 2003

The spatial distributions of canopy and subcanopy species (≥50 cm stem length) were investigated within a plot extending from the top of a ridge to the valley bottom in a cool‐temperate old‐growth mixed forest, dominated by Cryptomeria japonica and Fagus crenata, in the snowy region of Japan. Based on the longitudinal profile of the slope, the study slope was divided into the relatively gentle upper slope position (US), the steep lower slope position (LS), the flat valley bottom (VB) and the boundary zone between the upper and lower slopes (BS). Spatial dispersal and the association patterns of species were analyzed in upperstory (≥10 cm d.b.h) and understory (<10 cm d.b.h) layers. Dominant species in the upperstory layer abruptly changed from Cryptomeria to Fagus at the BS site. In contrast, the understory trees of many species, including shade‐intolerant and evergreen species, were independent of the location of conspecific upperstory trees or canopy gaps and extended their distributions on and around the BS site. Significant, diverse canopy and subcanopy species occurred at this site in both upperstory and understory layers. On the BS site, which is the lower margin of Cryptomeria‐dominated vegetation, there were many medium‐sized C. japonica that were killed by uprooting or breaking of the stems as a result of heavy snow pressure. It is suggested that the snow pressure gradient along a slope has a strong influence on community structure and the maintenance of diverse canopy and subcanopy species in this snowy mixed forest.
Why do B cells produce CD40 ligand?
Authors: Wykes Michelle
Published: July 2003

The CD40‐CD40 ligand (CD40L) interaction is one of the most important receptor−ligand interactions that occurs during a T dependent immune response. However, while CD40L is expressed on a range of cell types including activated T cells and B cells, dendritic cells granulocytes, macrophages and platelets, only CD40L on T cells is considered by most immunologists when planning experiments or analysing data. The current theory professes that T cells expressing CD40L can provide signals to B cells that induce proliferation, immunoglobulin class switching, antibody secretion, rescue from apoptosis at different times during the life of a B cell and also has a role in the development of germinal centres and the survival of memory B cells. However, the whole story is more complex than presently understood as human and mouse B cells express CD40L on their surface following activation and can release a soluble form of the ligand. This paper hypothesizes how CD40L on B cells may regulate antibody responses and the development of germinal centres.
mRNA of MUC2 is stimulated by IL‐4, IL‐13 or TNF‐α through a mitogen‐activated protein kinase pathway in human colon cancer cells
Authors: Iwashita Jun , Sato Yukita , Sugaya Hiroko , Takahashi Nagatomo , Sasaki Hiroshi , Abe Tatsuya
Published: July 2003

MUC2 mucin is a secretory glycoprotein which is produced from the intestinal goblet cells and is a major component of the intestinal epithelial mucus. The biological function of MUC2 mucin is considered to be the protection of intestinal epithelial surface, whereas the regulatory mechanism of MUC2 mucin production in immune response is not completely understood. We have studied the effects of cytokines, IL‐4, IL‐13 and TNF‐α, on the regulation of MUC2 mRNA in the human colonic cancer cell lines, LS174T and HT29. The quantitative reverse transcription‐polymerase chain reaction showed that single addition of IL‐4, IL‐13 and TNF‐α to cell culture induced about two‐fold increase of MUC2 mRNA level in LS174T cells. Interleukin‐4 and IL‐13 activated phosphorylation of mitogen‐activated protein kinase in LS174T cells. A specific inhibitor of mitogen‐activated protein kinase pathway, U0126, totally inhibited the increase of MUC2 mRNA by IL‐4 or IL‐13 in those cells. Therefore, mitogen‐activated protein activation of kinase is required for the increase of MUC2 mRNA by IL‐4 or IL‐13 in LS174T cells. In contrast to LS174T cells, only TNF‐α increased MUC2 mRNA through a mitogen‐activated protein kinase pathway in HT29 cells that express low levels of MUC2 mRNA. These findings sustain a novel phenomenon that MUC2 mRNA expression is differently controlled by IL‐4, IL‐13, or TNF‐α in LS174T and HT29 cells, whereas the mitogen‐activated protein kinase pathway plays a role in the MUC2 mRNA expression induced by those cytokines in both cell lines.
Cytotoxic T cells with reciprocal antigenic peptide presentation function are not generally resistant to mutual lysis
Authors: Staege Martin S , Gisch Karina , Reske‐Kunz Angelika B
Published: July 2003

Cytotoxic T cells normally express major histocompatibility complex class I molecules, to which their T cell antigen receptors are restricted. Therefore, a single cytotoxic T cell can not only act as a cytolytic effector cell, but also as an antigen‐presenting cell for other cytotoxic T cells of the same or a different clone. In the present paper, we used a murine cytotoxic T cell clone, 10BK.1, recognizing the ovalbumin‐derived peptide OVA257‐264 in combination with H‐2Kb to investigate the consequences of reciprocal antigen presentation by these cytotoxic T cells. These cells proliferate after incubation with the relevant peptide in the absence of added accessory cells, indicating reciprocal antigenic peptide presentation by the cytotoxic T cell. We found that reciprocal lysis of these cells was dependent on the time point of incubation with antigen. We did not observe reciprocal lysis of cytotoxic T cells used 30 days after the last restimulation with antigen. In contrast, 10BK.1 cells used two days after the last restimulation showed an increased capacity for reciprocal lysis. The lytic capacity decreased with time after restimulation. Reciprocal lysis of 10BK.1 cells depended on reciprocal peptide presentation by at least two 10BK.1 cells. Recognition of the antigenic peptide, together with class I molecules on the surface of classical syngeneic target cells did not induce lysis of freshly stimulated 10BK.1 cells, suggesting that reciprocal lysis was not just a consequence of re‐activation of the cytotoxic T cells. Reciprocal destruction of freshly activated 10BK.1 cells proceeded independent of CD95/CD95 ligand. Despite an increased secretion of tumour necrosis factor‐α by 10BK.1 cells on day 2 after antigen stimulation, compared with cells on day 30 after stimulation, tumour necrosis factor‐α was not responsible for the reciprocal destruction of freshly stimulated 10BK.1 cells. Lysis of preactivated 10BK.1 cells was independent of autocrine interleukin‐2 production by the cytotoxic T cells, but interleukin‐2 was required for optimal priming of cytotoxic T cells for reciprocal lysis.
Murine dendritic cell development: Difficulties associated with subset analysis
Authors: Wilson Heather L , O'Neill Helen C
Published: July 2003

Dendritic cells are bone marrow‐derived professional antigen presenting cells that play major roles in both the induction of primary immune responses and tolerance. It has become clear that dendritic cells are a heterogenous group of cells that vary in cell surface marker expression and function. Multiple dendritic cell subsets have now been defined in mouse lymphoid organs and peripheral tissues. A knowledge of the function and relationship between dendritic cell subsets will be essential for understanding the regulation of immune homeostasis, immune responses and tolerance. While an increasing number of dendritic cell progenitors are being identified, the pathways that connect them remain unclear. In addition, it is unclear whether the functional divisions reflect maturation status, subset specialization or functional plasticity in response to specific pathogen and environmental signals. This review summarizes the current knowledge about the function and lineage relationship of dendritic cell subsets. It also discusses some of the difficulties associated with dendritic cell subset analysis.
Alveolar macrophages from subjects with chronic obstructive pulmonary disease are deficient in their ability to phagocytose apoptotic airway epithelial cells
Authors: Hodge Sandra , Hodge Greg , Scicchitano Raffaele , Reynolds Paul N , Holmes Mark
Published: July 2003

Chronic obstructive pulmonary disease is a highly prevalent, complex disease, usually caused by cigarette smoke. It causes serious morbidity and mortality and costs the global community billions of dollars per year. While chronic inflammation, extracellular matrix destruction and increased airway epithelial cell apoptosis are reported in chronic obstructive pulmonary disease, the understanding of the basic pathogenesis of the disease is limited and there are no effective treatments. We hypothesized that the accumulation of apoptotic airway epithelial cells chronic obstructive pulmonary disease in could be due to defective phagocytic clearance by alveolar macrophages. There have been no previous studies of the phagocytic capacity of alveolar macrophages in chronic obstructive pulmonary disease using physiologically relevant apoptotic airway epithelial cells as phagocytic targets. We developed a phagocytosis assay whereby cultured 16HBE airway epithelial cells were induced to apoptosis with ultraviolet radiation and stained with mitotracker green. Alveolar macrophages from bronchoalveolar lavage from eight control and six chronic obstructive pulmonary disease subjects were analysed following 1.5 h incubation with apoptotic airway epithelial cells, then staining with macrophage marker anti CD33. CD33+/mitotracker green + events (i.e., alveolar macrophages which had phagocytosed apoptotic airway epithelial cells) were analysed using flow cytometry. Phagocytosis of polystyrene microbeads was investigated in parallel. A significantly reduced proportion of alveolar macrophages from chronic obstructive pulmonary disease subjects ingested apoptotic airway epithelial cells compared with controls (11.6 ± 4.1% for chronic obstructive pulmonary disease versus 25.6 ± 9.2% for control group). Importantly, the deficiency was not observed using polystyrene beads, suggesting that the failure to resolve epithelial damage in chronic obstructive pulmonary disease may result, at least partially, from specific defects in phagocytic ability of alveolar macrophages to ingest apoptotic airway epithelial cells.
Optimization of an ovine antibody‐secreting cell assay for detection of antigen‐specific immunoglobulin production in peripheral blood leukocytes
Authors: Sedgmen Bradley J , Lofthouse Shari A , Meeusen Els NT
Published: July 2003

Enumeration of antibody‐secreting cells in peripheral blood by enzyme‐linked immunospot (ELISPOT) has been used in human studies to detect antigen‐specific antibody production at mucosal tissue sites. An alternative assay for detecting and quantitating antigen‐specific antibody responses involves culturing circulating peripheral blood antibody‐secreting cells and quantitating specific antibody production in culture supernatant by ELISA. In the present study, antigen‐specific peripheral blood lymphocytes were isolated from subcutaneously immunized sheep and the parameters for maximizing in vitro antibody production by in vivo‐induced antibody‐secreting cells optimized for this species. Maximum antibody‐secreting cell responses were observed in peripheral blood collected four days after antigen challenge. The addition of lipopolysaccharide and antisheep immunoglobulin had no effect on in vitro antibody secretion by blood antibody‐secreting cells, while the effects of pokeweed mitogen were highly variable. However, the combination of anti‐Ig and recombinant ovine interleukin‐6 to peripheral blood lymphocyte cultures was found to markedly and consistently enhance specific antibody production. In unstimulated cultures, the optimal peripheral blood lymphocyte concentration for generating the greatest antibody responses was 5.0 × 107 cells per mL, but in cultures stimulated with recombinant ovine interleukin‐6/antisheep immunoglobulin, the optimal cell concentration was lowered to approximately 1.0 × 107 cells per mL. In vitro, peak immunoglobulin production was usually achieved by day one in unstimulated cultures. In recombinant ovine interleukin‐6/antisheep immunoglobulin‐stimulated cultures, antibody levels were similar to unstimulated cultures by day one, however, the levels continued to rise during incubation to reach a maximum between days four and five of incubation. This optimized antibody‐secreting cell culture assay is amenable for increasing the sensitivity and reducing the cell numbers required for quantitating antigen‐specific antibody induction in large‐scale immunization trials in sheep and other large animal species.
A novel CD44 antibody identifies an epitope that is aberrantly expressed on acute lymphoblastic leukaemia cells
Authors: Bendall Linda J , James Alexander , Zannettino Andrew , Simmons Paul J , Gottlieb David J , Bradstock Kenneth F
Published: July 2003

Previous studies have shown that the antibody 7H9D6 identifies CD44, a glycoprotein receptor for hyaluronic acid. 7H9D6 recognizes an epitope of CD44 that is not always present on CD44 molecules. The 7H9D6 antibody bound to the hyaluronic acid binding domain of CD44 and inhibited cell adhesion to immobilized hyaluronic acid. However, the expression of the 7H9D6 epitope was not sufficient for hyaluronic acid binding. Immunofluorescent staining with 7H9D6 revealed a punctate surface staining pattern, suggesting that CD44 molecules recognized by 7H9D6 are located in clusters on the cell surface. In contrast, other CD44 antibodies produced a uniform staining pattern. Early bone marrow B cells were negative for 7H9D6 but reactive with other CD44 monoclonal antibodies. In contrast, leukaemic cells from 65% of patients (28 of 43) with B lineage acute lymphoblastic leukaemia bound 7H9D6. Patients expressing the 7H9D6 epitope on their leukaemic cells had an increased risk of death (HR 3.5 95% CI 1.1−10.9, P = 0.029) and of disease relapse (HR 3.2 95% CI 1.2−8.5, P = 0.017) when corrected for white cell count. This antibody may be useful for the detection of residual disease in B lineage acute lymphoblastic leukaemia and as a prognostic indicator and for the study of CD44 function.
Mucosal vascular addressin cell adhesion molecule‐1 is expressed outside the endothelial lineage on fibroblasts and melanoma cells
Authors: Leung Euphemia , Kanwar Rupinder K , Kanwar Jagat R , Krissansen Geoffrey W
Published: July 2003

Mucosal vascular addressin cell adhesion molecule‐1 (MAdCAM‐1) is predominantly expressed on high endothelial venules in inflamed tissues where it assists with leucocyte extravasation. Here we report that MAdCAM‐1 has the potential to be more widely expressed outside the endothelial cell lineage than previously appreciated. Thus, MAdCAM‐1 RNA transcripts and cell‐surface protein were expressed by NIH 3T3 fibroblasts following activation with tumour necrosis factor‐α (TNF‐α), and by freshly isolated and cultured primary mouse splenic and tail fibroblasts in the absence of TNF‐α stimulation. They were constitutively expressed by B16F10 melanoma cells, and expression was enhanced by cell activation with TNF‐α. Mucosal vascular addressin cell adhesion molecule‐1 was expressed on the apical surface of isolated cells, but became predominantly localized to cell junctions in confluent cell monolayers, suggesting it may play a role in the homotypic aggregation of cells. Tumour necrosis factor‐α enhanced the expression of a firefly luciferase reporter directed by the MAdCAM‐1 promoter in NIH 3T3 and B16F10 cells. A DNA fragment extending from nt −1727 to −673 was sufficient to confer cell‐type selective expression. Mucosal vascular addressin cell adhesion molecule‐1 expressed by NIH 3T3 cells was biologically active, as it supported the adhesion of TK‐1 T cells in an α4β7‐dependent fashion. The expression of MAdCAM‐1 by fibroblasts, and melanomas suggests MAdCAM‐1 may play a role in regulating host responses in the periphery, leucocyte transmigration across nonendothelial boundaries, or the homotypic interactions of some malignant melanomas.
Tryptophan and the immune response
Authors: Moffett John R , Namboodiri MA Aryan
Published: July 2003

The immune system continuously modulates the balance between responsiveness to pathogens and tolerance to non‐harmful antigens. The mechanisms that mediate tolerance are not well understood, but recent findings have implicated tryptophan catabolism through the kynurenine metabolic pathway as one of many mechanisms involved. The enzymes that break down tryptophan through this pathway are found in numerous cell types, including cells of the immune system. Some of these enzymes are induced by immune activation, including the rate limiting enzyme present in macrophages and dendritic cells, indoleamine 2,3‐dioxygenase (IDO). It has recently been found that inhibition of IDO can result in the rejection of allogenic fetuses, suggesting that tryptophan breakdown is necessary for maintaining aspects of immune tolerance. Two theories have been proposed to explain how tryptophan catabolism facilitates tolerance. One theory posits that tryptophan breakdown suppresses T cell proliferation by dramatically reducing the supply of this critical amino acid. The other theory postulates that the downstream metabolites of tryptophan catabolism act to suppress certain immune cells, probably by pro‐apoptotic mechanisms. Reconciling these disparate views is crucial to understanding immune‐related tryptophan catabolism and the roles it plays in immune tolerance. In this review we examine the issue in detail, and offer additional insight provided by studies with antibodies to quinolinate, a tryptophan catabolite which is also necessary for nicotinamide adenine dinucleotide (NAD +) production. In addition to the immunomodulatory actions of tryptophan catabolites, we discuss the possible involvement of quinolinate as a means of replenishing NAD + in leucocytes, which is depleted by oxidative stress during an immune response.
Case of mucinous adenocarcinoma with porcelain gallbladder
Authors: JOO YOUNG‐EUN , KIM HYUN‐SOO , CHOI SUNG‐KYU , REW JONG‐SUN , KIM HYUN‐JONG , KANG HEOUNG‐KEUN , JUHNG SANG‐WOO , KIM SEI‐JONG
Published: July 2003

Abstract Histologically, the majority of gallbladder cancers are adenocarcinomas. Among the adenocarcinomas, the mucinous adenocarcinoma is relatively uncommon. Porcelain gallbladder is a rare finding and the risk of gallbladder cancer is significantly increased in porcelain gallbladder. We describe a rare case of mucinous adenocarcinoma with porcelain gallbladder. A 46‐year‐old man was admitted to Chonnam National University Hospital with a 2‐week history of right upper quadrant pain. Three and 2 years previously, he had two episodes of cholecystitis with gallstones. An abdominal computed tomography revealed a contracted gallbladder with circumferential mural calcification, and the possibility of gallbladder cancer and porcelain gallbladder were considered. At laparotomy, cholecystectomy, liver wedge resection, and radical lymph node dissection were performed. The resected gallbladder showed thickened wall, luminal narrowing and mucosal irregularity. A histological examination of the resected gallbladder showed a mucinous adenocarcinoma composed of poorly differentiated glandular cells with mucin lakes. Porcelain gallbladder may be an end result of a chronic inflammatory reaction, and this change is associated with the development of gallbladder cancer.
Peripheral neuropathy in liver cirrhosis
Authors: KHARBANDA PARAMPREET S , PRABHAKAR SUDESH , CHAWLA YOGESH K , DAS CHANDI P , SYAL PUNEET
Published: July 2003

Background and Aims:  Neuropathy in association with chronic liver disease, including cirrhosis, is recognized; however, there are differences in the incidence and type of neuropathy reported. The causal relationship of liver disease to neuropathy has been questioned. This study was designed to evaluate the incidence and character of peripheral neuropathy in patients with liver cirrhosis. The effect of alcohol consumption, severity of liver disease and encephalopathy on the incidence and severity of neuropathy were also studied.

Methods:  Patients having an identifiable cause of peripheral neuropathy, except alcohol, were excluded from the study. Patients with evidence of vitamin B12 deficiency or diabetes were also excluded from the study. In this study, 33 patients with liver cirrhosis were evaluated clinically and electrophysiologically to detect any evidence of peripheral neuropathy. Nerve conduction studies were performed in the upper and lower limbs using surface electrodes. These patients also underwent a detailed clinical examination.

Results:  Clinical signs of peripheral neuropathy were found in seven (21%) patients. Nerve conduction studies were abnormal in 24 (73%) patients. The pattern of involvement was predominantly of an axonal sensory motor polyneuropathy. Neuropathy was found both in patients with alcohol‐related and non‐alcohol‐related cirrhosis. The presence of encephalopathy did not have a significant bearing on the incidence and severity of neuropathy. The neuropathy was also not significantly related to the severity of liver disease.

Conclusions:  The present study reveals that a significant number of patients with liver cirrhosis show evidence of peripheral neuropathy, which is present regardless of the etiology of cirrhosis, and is subclinical in a majority of these patients. The cause of neuropathy was probably the liver disease itself, as the incidence and severity of neuropathy in the alcohol‐related cirrhosis, although higher, was not significantly different from the neuropathy in patients with non‐alcohol‐related cirrhosis.
Hepatic ischemia reperfusion injury: Pathogenic mechanisms and basis for hepatoprotection
Authors: TEOH NARCI C , FARRELL GEOFFREY C
Published: July 2003

Abstract  This review highlights recent advances in our understanding of mechanisms underlying reperfusion injury to the liver after warm hepatic ischemia. Sinusoidal endothelial cells and hepatocytes are targets of injury in the early ‘cytotoxic’ phase, although participation of apoptosis in the cell‐death process remains contentious. Kupffer cells may play an important role as the initial cytotoxic cell type and are likely a source of reactive oxygen species and proinflammatory mediators, particularly tumor necrosis factor (TNF)‐α. The latter are involved with subsequent neutrophil activation and recruitment. Microcirculatory disruption results from an imbalance between the actions of vasoconstrictors and vasodilators, such as nitric oxide, and also has a major impact on reperfusion injury. There is growing evidence that a brief prior ischemia–reperfusion period, termed ‘ischemic preconditioning’, is hepatoprotective. This can be mimicked by drugs that produce oxidative stress, and by interleukin‐6 and TNF‐α; both these cytokines are involved with priming hepatocytes to enter the cell cycle. Several mechanisms have been implicated including mobilization of adenosine and activation of adenosine type 2 receptors, nitric oxide, abrogation of TNF synthesis, preservation of energy metabolism, protection of the microcirculation and accelerated cell‐cycle entry. A better understanding of preconditioning mechanisms will lead to novel approaches to improve outcomes of liver surgery.
Clinicopathological features and management of gallbladder cancer in Pakistan: A prospective study of 233 cases
Authors: MALIK IMTIAZ A
Published: July 2003

Background and Aims:  Gallbladder cancer is common in Pakistan and has an extremely poor prognosis. Treatment is primarily surgical. Chemotherapy is frequently used in patients with advanced disease. This study was performed to evaluate and compare the clinicopathological features and management of gallbladder cancer in Pakistani patients, with particular emphasis on factors that influence survival.

Methods:  Two hundred and thirty‐three patients with histologically proven gallbladder cancer were studied. Information was prospectively collected on demographic features, clinical and laboratory findings at the time of presentation, influence of therapy, and survival. Data were analyzed to evaluate variables that influenced survival. Kaplan–Meier analysis was used to calculate survival.

Results:  Most patients were women (77%). Mean age was 55 years (±11 years). Fourteen per cent of females were nulliparous. Twenty‐six per cent had five or more children. Only 4% of patients had a documented history of typhoid fever. The majority (69%) had a history of symptomatic gallbladder disease. The commonest presenting symptom was pain (89%), followed by nausea and vomiting (52%), weight loss (42%), and jaundice (33%). One‐quarter of patients had a palpable abdominal mass. Most had abnormal hepatic function tests and 58% had elevated carcinoma embryonic antigen levels. Stage (P < 0.001), jaundice (P = 0.01) and palpable mass (P = 0.02) were statistically significant variables. However, on multivariate analysis, tumor node metastases (TNM) stage was the only factor influencing survival. Median survival of the patients was 44 months for patients with stage I disease, 23 months for stage II, 17 months for stage III and 6 months for stage IV.

Conclusion:  These data are comparable with those reported from other developing countries. Most patients presented at an advanced stage of disease and had an extremely poor prognosis. Systemic therapy did not provide any survival benefit. The TNM stage remains the most important factor influencing survival.