bluuebunny/crossref_metadata_2025 huggingface dataset:
Seed demography
Authors: Cavers Paul B.
Published: October 2007

"Some seeds fell by the way side, … some fell upon stony places,... and some fell among thorns;.... but other fell into good ground" (The Bible, St. Matthew's gospel, Chapt. 13).Much of modern plant ecology is concerned with demography. One major topic is the study of mortality rates. A common belief, originating with Charles Darwin's Origin of Species is that the seedling stage of the plant's life cycle exhibits the highest mortality rates. Evidence is provided in this paper to show that the highest rates of mortality for many species occur at the seed stage. The major causes of mortality associated with five major functions served by seeds are discussed. These functions enable the population to (i) invade new areas, (ii) occupy all possible microsites within a habitat, (iii) survive unfavorable periods, (iv) avoid predators and pathogens, and (v) recruit new genotypes which will be more successful in growth, survival, and reproduction than their predecessors. Seed mortality, somewhat paradoxically, has an integral role in each of these functions. The discussion includes a consideration of mortality at all stages of the seed's life history from formation through to germination.
Early establishment and vegetative growth of understory species in the western hemlock – Sitka spruce forests of southeast Alaska
Authors: Tappeiner II John C. , Alaback Paul B.
Published: October 2007

To determine how Vaccinium alaskaense, Cornus canadensis, Coptis asplenifolia, Tiarella trifoliata, and Rubus pedatus invade and maintain themselves in conifer forests, we conducted experiments on seed germination and seedling survival and examined clonal development in old-growth, young-growth, and 4- to 6-year-old stands. Seed of all species germinated well in laboratory and field tests (average 23 – 90%), but low germination rates of C. canadensis and T. trifoliata under actual field conditions may retard their invasion of young stands. Survival of all species at 3 and 4 years was lower in the young stand (40 years) than in the old stand (250 + years) and may be related to incident solar radiation. Regressions of the percentage of survival on percentage of transmitted solar radiation were significant (P ≤ 0.05) for all species except C. canadensis. Seed predation and type of seedbed (moss, logs, duff) had little effect on germination and survival rates. Average annual rhizome or stolon growth was slower in the young stand (1 – 3 cm) than in the old stand (1 – 34 cm). In the clearcut, clones had dense foliage because of shorter internodes and more leaves per node and annual rhizome and stolon growth averaged 77 – 160 cm. Both seedling establishment among clones and continual clonal expansion maintain species in old stands, while invasion in young stands is primarily by seedling establishment.
In vitro viability of diaspores in Limbella (Musci: Amblystegiaceae)
Authors: Christy John A.
Published: October 2007

Spores of Limbella tricostata and fragments of living gametophytes of L. tricostata and L. fryei germinated readily and grew prolifically in vitro. Viability of fragments of live plants was directly proportional to the size of the fragment. Growth rates were similar to those observed for other aquatic mosses. Plants dried above 20 °C for longer than 24 h did not regenerate. Fungi appeared in cultures as decomposers, not pathogens.
Acetylene-induced decline in acetylene reduction by nodulated roots of alfalfa
Authors: Macdowall F. D. H. , Kristjansson G. T.
Published: October 2007

Seedlings of three cultivars of alfalfa (Medicago sativa L.) were nodulated with two strains of rhizobia (Rhizobium meliloti) and grown with zero N nutrients at 25:20 °C for 6 weeks followed by growth at 10:7 °C for 2 weeks. Acetylene-reducing activity (ARA) was retarded by 10% acetylene to an extent dependent on time, cultivar, strain, and growth temperature. In the usual short term assay for nitrogenase by ARA, the inhibition was not sufficient to explain decreased apparent efficiency of nitrogenase in plants moved to the lower temperature. Inhibition of ARA was associated with correspondingly decreased respiration in cv. Drylander, but in cv. Apollo respiration was not affected. The differential loss of ARA relative to respiratory activity in a day of continuous treatment with 10% acetylene was very distinct and requires an explanation other than altered nodule resistance to diffusion of oxygen.
Anatomy and histochemistry of stromatal anamorphs in the Sclerotiniaceae
Authors: Kohn Linda M. , Grenville Douglas J.
Published: October 2007

As part of comparative studies of stromata in the Sclerotiniaceae, mature sclerotial and substratal stromata produced in vitro by 19 species, and 1 form-species, representing 13 genera and 1 form-genus, were examined using light microscopy and histochemical staining. Sclerotial-stromatal taxa were Sclerotinia sclerotiorum, S. trifoliorum, S. minor. Sclerotium cepivorum, Botrytis cinerea, B. porri, Dumontinia tuberose, Ciborinia erythronii, Myriosclerotinia dennisii, M. borealis, Monilinia fructicola, and Stromatinia gladioli. Substratal-stromatal taxa were Lambertella subrenispora, Lanzia luteovirescens, Rutstroemia sydowiana, Stromatinia gladioli, Ovulinia azaleae, Sclerotinia homoeocarpa, Scleromitrula shiraiana, and Ciboria acerina. Histochemical staining, particularly 0.05% toluidine blue O in benzoate buffer at pH 4.4, was found to be useful in demarcating the zones within stromata: rind, cortex, and medulla. All sclerotia contained extensive reserves of carbohydrates in thick cell walls and copious extracellular matrix, while protein bodies were usually the major cytoplasmic storage reserve. A group of saprophytic, substratal isolates had thin medullary cell walls and less extracellular matrix, and did not store protein but stored large deposits of lipid in cytoplasm. A group of phytopathogenic, substratal-stromatal isolates appeared to be transitional, with anatomical features and extensive cytoplasmic protein body reserves suggesting that they produce indeterminate sclerotial stromata rather than true substratal stromata.
Branching and leaf initiation in the erect aerial system of Stromatopteris moniliformis (Gleicheniaceae)
Authors: Hébant-Mauri R. , Veillon J. M.
Published: October 2007

The erect, upright shoots of Stromatopteris moniliformis Met., a gleicheniaceous fern endemic to New-Caledonia, are studied morphologically and histologically. The shoots are produced by an underground branching system (not studied) and traverse the soil litter. They form dormant buds in their lowermost part and several leaves in the upper part, before the terminal meristem degenerates. Afterwards, the dormant lateral buds start to develop, successively and basipetally, toward the soil litter surface. These also produce dormant buds in their lowermost part and some leaves distally. This fern, therefore, has a bushlike form of dense branching axes, with leaves confined to the tip, unique in this group.
Development of infection structures of Uromyces transversalis in leaves of the host and a nonhost
Authors: Ferreira Johan F. , Rijkenberg F. H. J.
Published: October 2007

Substomatal vesicle development of Uromyces transversalis on its host, gladiolus, was studied with a scanning electron microscope. Development after penetration occurred in distinct stages; the single infection peg developed into a globose immature substomatal vesicle, which initiated, singly or in pairs, primary hyphae that frequently developed asynchronously. One of the observed elongated primary hyphae delimited a haustorial mother cell. Observations on the orientation of the long axis of the substomatal vesicle in relation to the stomatal slit showed development of the primary hyphae at right angles rather than acute angles or parallel. A similar trend was observed in the substomatal vesicle formed in a nonhost, corn.
Tree branches as populations of twigs
Authors: Wilson Brayton F.
Published: October 2007

Populations of twigs (1-year-old, current branch segments) had similar frequency distributions of twig lengths on branches of five tree species (Quercus coccinea, Acer rubrum, Picea rubens, P. abies, Pinus strobus). The modal number of twigs for each of the species was in the 1, 2, 3, or 4 cm length class, with an exponential decrease in twig number through the 6- to 10-cm class plus a few longer twigs. These characteristic twig frequency distributions developed within the first decade of the life of a branch and were retained as the twig population size changed. Old branches had twigs only less than 5 cm long. The number of new twigs increased as their parent's (2-year-old segments, last year's growth) lengths increased. On parents with more than one twig the terminal twig was longest. Length of the shortest twig, furthest from the terminal, generally increased as parent length increased, but, in Acer rubrum, stayed less than 1 cm. Frequency distributions were determined for the lengths of terminal twigs from parents less than 5 cm long. Mortality of parents in conifers was first indicated when they produced no twigs. A simple computer model simulated growth of twig populations using equations and probabilities to calculate the number and lengths of new twigs formed by parents.
Photo-induction sexuée du pyrénomycète Nectria galligena: influence de la mycosporine sur le rapport des activités NADPM+-socitrate déshydrogénase/isocitrate lyase
Authors: Dehorter B. , Lacoste L.
Published: October 2007

The activity of two enzymes of the tricarboxylic acid cycle (NADP+-isocitrate dehydrogenase, EC 1.1.1.42) and the glyoxylate cycle (isocitrate lyase, EC 4.1.3.1) were assayed in vitro to determine the effects of darkness, light, and mycosporin (P310) on sexual morphogenesis in Nectria galligena Bres. In the absence of mycosporin, high isocitrate lyase activity was associated with vegetative growth of fungi kept in the dark. In contrast, light-induced perithecial development and mycosporin biosynthesis could be correlated with high ratios of isocitrate dehydrogenase to isocitrate lyase activity. This was confirmed by the fact that when mycosporin was added to the nutrient medium with incubation in darkness, the fertility of the fungus was partially expressed and the activity of isocitrate lyase was significantly reduced. Thus this enzyme would be repressed in vivo by mycosporin. Because of its photomimetic role in sexual differentiation and regulation of intermediate metabolism, mycosporin appears to be a biochemical transmitter of light energy required for the formation of ascocarps.
Role of the seed bank in providing colonizers on a tundra disturbance in Alaska
Authors: Ebersole James J.
Published: October 2007

Numbers of germinable seeds in soils from four undisturbed communities at an Alaskan Arctic Coastal Plain site ranged from 70 to 600 m−2 and numbers of distinct taxa were two to nine. Stratified soils contained more germinable taxa than unstratified soils, suggesting that seed banks in Alaskan tundra are more diverse than shown by earlier studies using unstratified soils. In contrast to temperate seed banks, which often contain early successional species no longer present in the vegetation, all seed bank taxa at this site occur within a short distance of the sample sites because of long persistence of the communities. Of the common colonizers on a nearby 30-year-old disturbance, Betula nana, Poa arctica, Salix spp., and Arctagrostis latifolia are absent or present in only small amounts in the seed bank and apparently colonize mainly from seeds dispersed following disturbance. Eriophorum angustifolium, another common colonizer, is present in the seed bank of wet areas and Carex bigelowii and C. aquatilis are abundant in the seed bank of several communities. Germination from the seed bank is an important means of colonizing disturbances for these taxa. No trend in seed bank size with intensity of disturbance (cryoturbation) was found, and comparison with other studies shows that seed bank size in Eriophorum vaginatum tussock tundra decreases with latitude.
Effects of phosphorus deficiency on root hydraulic conductivity in Fraxinus pennsylvanica
Authors: Andersen Christian P. , Sucoff Edward I. , Dixon Robert K. , Markhart III Albert H.
Published: October 2007

A study was designed to examine the influence of phosphorus deficiency on root hydraulic characteristics in green ash (Fraxinus pennsylvanica Marsh.). Seedlings were grown in nutrient solution complete with phosphorus for 7 days before omitting phosphorus from one half of the seedlings. The effects of phosphorus deficiency, plant size, and biomass distribution on root hydraulic conductivity were determined on excised root systems after 17 to 48 d of growth with or without phosphorus. Phosphorus deficiency reduced root conductivity and decreased leaf weight ratios (leaf dry weight/total plant dry weight) in green ash seedlings. In both the high (with phosphorus) and low phosphorus (without phosphorus) treatments, root conductivity increased linearly with increased root phosphorus concentration. However, the relationship between root phosphorus and root conductivity differed in magnitude in the high and low phosphorus treatments, suggesting that factors besides phosphorus nutrition were influencing root conductivity. Root conductivity increased with leaf weight ratio similarly in high and low phosphorus plants regardless of seedling size, tissue phosphorus, or age. Root conductivity decreased with seedling age, possibly because of increased root suberization. Root conductivity to water appears to change in response to a change in biomass distribution in green ash.
Involvement of ethylene in ectomycorrhiza formation and dichotomous branching of roots of mugo pine seedlings
Authors: Rupp L. A. , Mudge K. W. , Negm F. B.
Published: October 2007

The role of ethylene in mycorrhiza formation and root development on axenically grown seedlings of Pinus mugo Turra var. mugo was examined. Mycorrhizal formation by Laccaria laccata and Pisolithus tinctorius in a defined liquid medium was associated with increased ethylene production. Ethephon (100 μM) stimulated dichotomous branching of roots inoculated with P. tinctorius, but had no effect on those inoculated with L. laccata, or on uninoculated roots. Ethephon had no effect on the percentage of susceptible roots that became mycorrhizal with either fungus. The inhibitor of ethylene action, silver thiosulfate, had no significant effect on mycorrhiza formation by P. tinctorius, but it did show a trend toward decreased mycorrhiza formation by L. laccata when applied at concentrations of 10 μM or higher. Silver thiosulfate at 100 or 500 μM slightly increased dichotomous root branching of seedlings inoculated with either fungus, but these concentrations also caused blackening of root meristems and inhibition of root growth. These results are consistent with the interpretation that endogenous ethylene may influence mycorrhiza formation and associated changes in root morphology.
Effect of aminocyclopropane carboxylic acid and aminoethoxyvinylglycine on ethylene production by ectomycorrhizal fungi
Authors: Rupp L. A. , DeVries II H. E. , Mudge K. W.
Published: October 2007

Aminoethoxyvinylglycine, an inhibitor of ethylene production in higher plants, does not inhibit methionine-induced ethylene production by the ectomycorrhizal fungus Laccaria laccata (Scop, ex Fr.) Berk. & Br. Aminocyclopropane carboxylic acid is not a precursor of ethylene formation by L. laccata or Hebeloma crustiliniforme.
Vegetation patterns in James Bay coastal marshes. II. Physiological adaptation to salt-induced water stress in three halophytic graminoids
Authors: Ewing Kern , Earle J. Chris , Piccinin Beryl , Kershaw Kenneth A.
Published: October 2007

The responses of three halophytes to an incremental increase in soil-water salinity have been studied under greenhouse conditions. Biomass accumulation of both the roots and shoots of each species decreased markedly as osmotic stress increased. Differences in salt sensitivity accounted for the species natural separation along a salinity gradient identified from the low marsh to the high marsh. The three species utilized different strategies to metabolically lower their internal osmotic potential during salt stress. Puccinellia phryganodes reduced cell water content and accumulated high concentrations of proline. Carex paleacea exhibited no adjustment in water retention, but accumulated high concentrations of glycine betaine and a small amount of proline. The most salt-sensitive species, Scirpus americanus, reduced cell water content while it accumulated high concentrations of glycine betaine. The reliance on proline as an osmoregulant in P. phryganodes is suggested to be an adaptation to its highly fluctuating salinity regime. There is no definitive evidence that suggests that any of the species accumulate carbohydrates in response to saline stress. The loss of reducing sugars in C. paleacea and S. americanus grown under moderately saline conditions (i.e., 5 and 10 ppt) may be attributed to a significant reduction in the photosynthetic capacity of the species. The subsequent increase in carbohydrates at higher salinities may have been due to their accumulation during severe osmotic stress.
Organogenèse de la fleur pistillée du Begonia horticola (Begoniaceae)
Authors: Charpentier Anne , Brouillet Luc , Barabé Denis
Published: October 2007

The placentation of the inferior ovary of the female flower of Begonia horticola Irmscher (section Tetraphila) is mostly axile with the upper part parietal. A study of the vascular organisation and of the organogenesis of this species allows us to better understand the transition from axile to parietal placentation observed in other Begoniaceae, from both morphological and evolutionary points of view. The anatomy of the mature female flower is similar to that of other Begonia species. Anatomical sections and scanning electron microscopy of young developmental stages show that the inferior ovary grows underneath the perianth primordia. The two types of placentation are established early. The axile part develops from an axial meristem, while the parietal placentas are formed by the development of septa towards the inside of the cavity. It is however impossible to draw a clear boundary between the two tissues. The present data do not allow us to infer the evolutionary status of placentation types in Begonia.
Field observations on growth and development of Morchella rotunda and Mitrophora semilibera in relation to forest soil temperature
Authors: Buscot F.
Published: October 2007

In the upper Rhine forests, ascocarps of Morchella rotunda (Pers.) Boudier and Mitrophora semilibera (DC.) Lév. develop at the expense of preexisting subterranean mycelial structures (connective mycelium and mycelial muffs) associated with higher plants. Field data correlate the initial extent of springtime reheating of soil with ascocarp maturation and suggest that mycelial muffs may be storage and resistance structures formed as early as the summer preceding the spring fruiting. This suggests morels are biennial.
Whole-genome array-CGH for detection of submicroscopic chromosomal imbalances in children with mental retardation
Authors: Thuresson A.-C. , Bondeson M.-L. , Edeby C. , Ellis P. , Langford C. , Dumanski J.P. , Annerén G.
Published: October 2007

Chromosomal imbalances are the major cause of mental retardation (MR). Many of these imbalances are caused by submicroscopic deletions or duplications not detected by conventional cytogenetic methods. Microarray-based comparative genomic hybridization (array-CGH) is considered to be superior for the investigation of chromosomal aberrations in children with MR, and has been demonstrated to improve the diagnostic detection rate of these small chromosomal abnormalities. In this study we used 1 Mb genome-wide array-CGH to screen 48 children with MR and congenital malformations for submicroscopic chromosomal imbalances, where the underlying cause was unknown. All children were clinically investigated and subtelomere FISH analysis had been performed in all cases. Suspected microdeletion syndromes such as deletion 22q11.2, Williams-Beuren and Angelman syndromes were excluded before array-CGH analysis was performed. We identified de novo interstitial chromosomal imbalances in two patients (4%), and an interstitial deletion inherited from an affected mother in one patient (2%). In another two of the children (4%), suspected imbalances were detected but were also found in one of the non-affected parents. The yield of identified de novo alterations detected in this study is somewhat less than previously described, and might reflect the importance of which selection criterion of patients to be used before array-CGH analysis is performed. However, array-CGH proved to be a high-quality and reliable tool for genome-wide screening of MR patients of unknown etiology.
Initial maternal meiotic I error leading to the formation of a maternal i(2q) and a paternal i(2p) in a healthy male
Authors: Baumer A. , Basaran S. , Taralczak M. , Cefle K. , Ozturk S. , Palanduz S. , Schinzel A.
Published: October 2007

We report on the investigation of the parental origin and mode of formation of the two isochromosomes, i(2p) and i(2q), detected in a healthy adult male. Conventional cytogenetic analysis revealed the proband’s lack of structurally normal chromosomes 2, these being replaced by an i(2p) and an i(2q). Investigation of the parental origin of the isochromosomes revealed a paternal origin of the i(2p) chromosome and a maternal origin of the i(2q) chromosome. Thus, the formation of both isochromosomes, or at least of the paternal i(2p), appears to have occurred postzygotically. Interestingly, whilst a paternal isodisomy was observed for the entire 2p, maternal heterodisomy was detected for two segments of 2q, separated by a segment showing isodisomy. The results are indicative of an initial error (non-disjunction or i(2q) formation) concerning the maternal chromosomes 2 during meiosis I, which likely favored the subsequent mitotic recombination event resulting in the presence of two isochromosomes. To the best of our knowledge this is the first case of an initial meiotic error, followed by postzygotic trisomy rescue through the formation of isochromosomes, resulting in a normal phenotype. A prenatal detection, by cytogenetic and molecular analysis, of such chromosome abnormality would have led to the incorrect conclusion of a most likely poor prognosis for the fetus.
Exclusion of NFYB as candidate gene for congenital splay leg in piglets and radiation hybrid mapping of further five homologous porcine genes from human chromosome 12 (HSA12)
Authors: Boettcher D. , Paul S. , Bennewitz J. , Swalve H.H. , Thaller G. , Maak S.
Published: October 2007

Nuclear transcription factor Y, beta (NFYB) was evaluated as candidate gene for congenital splay leg in piglets based on data from differential display and QTL analysis. We mapped NFYB to pig chromosome 5 (SSC5). By assigning further five porcine genes from the corresponding region on human chromosome (HSA) 12q23.3→ q24.11 to SSC5 and 14 we could confine an evolutionary breakpoint from an interval of more than 10 Mb to less than 400 kb. Comparative sequence analysis of the coding region of NFYB in healthy and splay leg piglets revealed no polymorphism. Inter-species conservation of the codons ranges from 87% to 95% between pig, human, cow, dog, rat and mouse, respectively. The expression of NFYB in M. biceps femoris was not different between healthy and splay leg piglets. However, healthy male piglets had a significantly higher expression than females. Our results exclude NFYB as candidate gene for congenital splay leg but provide a basis for selection of further candidates for the disease from SSC5.
Karyotypic differences in two sibling species of Scotophilus from South Africa (Vespertilionidae, Chiroptera, Mammalia)
Authors: Eick G.N. , Jacobs D.S. , Yang F. , Volleth M.
Published: October 2007

Karyotype descriptions are given for Scotophilus dinganii (2n = 36, FNa = 50) and a recently discovered sister-species, Scotophilus sp. nov. (2n = 36, FNa = 52). These two sibling species occur sympatrically and are distinguished by body size, echolocation frequency and cytochrome b sequence. Cytogenetically, both species differ from other Scotophilus species in the subtelocentric morphology of chromosome 2 and a terminal heterochromatic segment on the X chromosome. Further, Scotophilus sp. nov. is characterized by a subtelocentric chromosome 4 not found in any other Scotophilus species. Comparing the Scotophilus karyotype with that of the vespertilionid genus Myotis, extensive conservation of whole chromosome arms has been found recently. However, out of 25 chromosomal arms six could not be identified in Scotophilus. Therefore, in the present study fluorescence in situ hybridization with whole chromosome painting probes from Myotis myotis was carried out on metaphase preparations from Scotophilus dinganii and Scotophilus sp. nov. These experiments revealed that three previously unidentified Scotophilus chromosomes (A, B, C) contain homologous sequences to Myotis chromosomes 18 plus 22, 19 plus 25, and 16/17, respectively.
Comparative chromosome mapping of 5S rDNA and 5SHindIII repetitive sequences in Erythrinidae fishes (Characiformes) with emphasis on the Hoplias malabaricus ‘species complex’
Authors: Ferreira I.A. , Bertollo L.A.C. , Martins C.
Published: October 2007

Chromosomal localization of 5S rDNA and 5SHindIII repetitive sequences was carried out in several representatives of the Erythrinidae family, namely in karyomorphs A, D, and F of Hoplias malabaricus, and in H. lacerdae, Hoplerythrinusunitaeniatus and Erythrinus erythrinus. The 5S rDNA mapped interstitially in two chromosome pairs in karyomorph A and in one chromosome pair in karyomorphs D and F and in H. lacerdae. The 5SHindIII repetitive DNA mapped to the centromeric region of several chromosomes (18 to 22 chromosomes) with variations related to the different karyomorphs of H. malabaricus. On the other hand, no signal was detected in the chromosomes of H. lacerdae, H. unitaeniatus and E. erythrinus, suggesting that the 5SHindIII-DNA sequences have originated or were lost after the divergence of H. malabaricus from the other erythrinid species. The chromosome distribution of 5S rDNA and 5SHindIII-DNA sequences contributes to a better understanding of the mechanisms of karyotype differentiation among the Erythrinidae members.
Steroid-Sparing Effect of Pimecrolimus Cream 1% in Children with Severe Atopic Dermatitis
Authors: Zuberbier Torsten , Heinzerling Lucie , Bieber Thomas , Schauer Uwe , Klebs Sven , Bräutigam Matthias
Published: October 2007

Objective: To investigate if pimecrolimus cream 1% reduces the need for steroids in the long-term management of severe pediatric atopic dermatitis (AD). Methods: A total of 184 pediatric patients (aged 2–17 years) with a history of severe AD according to Rajka and Langeland were enrolled. Patients were randomized to treatment with pimecrolimus cream or vehicle cream for a 24-week period. Prednicarbate 0.25% was applied as rescue medication. Results: Patients on pimecrolimus required steroids on a mean of 29% of study days, compared with 35% of patients on vehicle (p = 0.1841). On the head and neck only, the respective figures were 10 versus 19% (p = 0.0009). In patients enrolled with acute severe disease (Investigator’s Global Assessment ≧4), steroids were used on 28% of the days in the pimecrolimus group compared to 45% in the control group (p = 0.0024). On the head and neck, steroids were used on 10% of study days with pimecrolimus versus 30% with vehicle (p < 0.0001). Conclusion: The results indicate that the need for topical steroids on the head and neck is reduced with pimecrolimus cream 1% in the management of severe pediatric AD according to the definition of Rajka and Langeland.
Quality of Life Impairment and Psychological Distress in Elderly Patients with Psoriasis
Authors: Sampogna F. , Tabolli S. , Mastroeni S. , Di Pietro C. , Fortes C. , Abeni D.
Published: October 2007

Background/Aims: The management of psoriasis, which has a major impact on quality of life (QoL), deserves a specific attention to elderly patients’ problems and needs. Our aim was to describe the QoL of elderly patients with psoriasis. Methods: This is a cross-sectional study on 305 psoriatic inpatients, aged ≧65 years. QoL, measured by the Skindex-29, was compared in groups of patients based on clinical and sociodemographic characteristics, and the possible determinants of psychological distress were investigated. Results: The mean age of the patients was 71 years (range: 65–93). Clinical severity tended to increase with age. Psychological distress was higher in patients >70 years of age, while QoL showed an improvement for all the Skindex-29 scales in older age groups. Gender (women vs. men), and Skindex-29 emotions and functioning scales emerged as associated with psychological distress, after adjusting for age and clinical severity. Conclusion: These observations indicate that clinical severity of psoriasis increases among very elderly patients and is associated with different levels of skin-related QoL and psychological distress. It is important for dermatologists to be aware of the specific impact of psoriasis in the different subgroups of the elderly population, to meet the peculiar needs of each group.
Multiple and Clustered Eruptive Epidermoid Cysts following Treatment with Topical Imiquimod
Authors: Nasca Maria Rita , De Pasquale Rocco , Micali Giuseppe
Published: October 2007

A 61-year-old woman developed multiple and clustered eruptive epidermoid cysts at the site of treatment of a basal cell carcinoma located on her nose with imiquimod 5% cream (5 times/week for 6 weeks). Clearing was achieved after topical treatment with tretinoin 0.025% cream (1 application/day for 1 month).
Dermoscopic and Reflectance Confocal Microscope Findings of Trichoepithelioma
Authors: Ardigo Marco , Zieff Jonathon , Scope Alon , Gill Melissa , Spencer Philip , Deng Liang , Marghoob Ashfaq A.
Published: October 2007

Background: Trichoepitheliomas (TE) are benign neoplasms of follicular differentiation. Solitary lesions are often confused with basal cell carcinoma (BCC). Reflectance confocal microscopy (RCM) and dermoscopy are imaging tools for in vivo, noninvasive evaluation of skin lesions. To date, there has been no description of their findings in the evaluation of TE. Objective: Our aim is to describe the dermoscopic and RCM findings of histopathologically confirmed TE. Methods: Four TE were evaluated, 2 each of the desmoplastic and nondesmoplastic variants. RCM was performed on 1 of the desmoplastic and both of the nondesmoplastic lesions. Results: Dermoscopically, all of the lesions showed arborizing telangiectasias. The desmoplastic lesions also had an ivory-white background throughout. RCM showed oval, darker-appearing tumor islands that contained brightly refractile material, consistent with keratin horn cysts at the center, as well as parallel bundles of highly refractile dermal collagen surrounding the tumor islands. Conclusion: The ivory-white background throughout the lesion seen on dermoscopy may be helpful in distinguishing desmoplastic TE from BCC. The RCM findings in TE of keratin-filled cysts in tumor islands and attachment of the tumor to follicular structures have not been previously observed in BCC, and thus may also be diagnostically helpful. Further study is necessary for validation of these findings.
Topical Retapamulin Ointment, 1%, versus Sodium Fusidate Ointment, 2%, for Impetigo: A Randomized, Observer-Blinded, Noninferiority Study
Authors: Oranje Arnold P. , Chosidow Olivier , Sacchidanand Sarvajnamurthy , Todd Gail , Singh Krishan , Scangarella Nicole , Shawar Ribhi , Twynholm Monique
Published: October 2007

Background: Retapamulin is a novel pleuromutilin antibacterial developed for topical use. Objective: To compare the efficacy and safety of retapamulin ointment, 1% (twice daily for 5 days), with sodium fusidate ointment, 2% (3 times daily for 7 days), in impetigo. Methods: A randomized (2:1 retapamulin to sodium fusidate), observer-blinded, noninferiority, phase III study in 519 adult and pediatric (aged ≧9 months) subjects. Results: Retapamulin and sodium fusidate had comparable clinical efficacies (per-protocol population: 99.1 and 94.0%, respectively; difference: 5.1%, 95% confidence interval: 1.1–9.0%, p = 0.003; intent-to-treat population: 94.8 and 90.1%, respectively; difference: 4.7%, 95% confidence interval: –0.4 to 9.7%, p = 0.062). Bacteriological efficacies were similar. Success rates in the small numbers of sodium-fusidate-, methicillin- and mupirocin-resistant Staphylococcus aureus were good for retapamulin (9/9, 8/8 and 6/6, respectively). Both drugs were well tolerated. Conclusion: Retapamulin is a highly effective and convenient new treatment option for impetigo, with efficacy against isolates resistant to existing therapies.
The Endothelin-1 Pathway and the Development of Cardiovascular Defects in the Haemodynamically Challenged Chicken Embryo
Authors: Groenendijk Bianca C.W. , Stekelenburg-de Vos Sandra , Vennemann Peter , Wladimiroff Juriy W. , Nieuwstadt Frans T.M. , Lindken Ralph , Westerweel Jerry , Hierck Beerend P. , Ursem Nicolette T.C. , Poelmann Robert E.
Published: October 2007

Background/Aims: Ligating the right lateral vitelline vein of chicken embryos (venous clip) results in cardiovascular malformations. These abnormalities are similar to malformations observed in knockout mice studies of components of the endothelin-1 (ET-1)/endothelin-converting enzyme-1/endothelin-A receptor pathway. In previous studies we demonstrated that cardiac ET-1 expression is decreased 3 h after clipping, and ventricular diastolic filling is disturbed after 2 days. Therefore, we hypothesise that ET-1-related processes are involved in the development of functional and morphological cardiovascular defects after venous clip. Methods: In this study, ET-1 and endothelin receptor antagonists (BQ-123, BQ-788 and PD145065) were infused into the HH18 embryonic circulation. Immediate haemodynamic effects on the embryonic heart and extra-embryonic vitelline veins were examined by Doppler and micro-particle image velocimetry. Ventricular diastolic filling characteristics were studied at HH24, followed by cardiovascular morphologic investigation (HH35). Results: ET-1 and its receptor antagonists induced haemodynamic effects at HH18. At HH24, a reduced diastolic ventricular passive filling component was demonstrated, which was compensated by an increased active filling component. Thinner ventricular myocardium was shown in 42% of experimental embryos. Conclusion: We conclude that cardiovascular malformations after venous clipping arise from a combination of haemodynamic changes and altered gene expression patterns and levels, including those of the endothelin pathway.
Geometric Characteristics of Arterial Network of Rat Pial Microcirculation
Authors: Lapi D. , Marchiafava P.L. , Colantuoni A.
Published: October 2007

Objective: The aim of the study was to assess the geometric characteristics of rat pial microcirculation and describe the vessel bifurcation patterns by ‘connectivity matrix’. Methods: Male Wistar rats were used to visualize pial microcirculation by a fluorescent microscopy technique through an open cranial window, using fluorescein isothiocyanate bound to dextran (molecular weight 70 kDa). The arteriolar network was mapped by stop-frame images. Diameters and lengths of arterioles were measured with a computer-assisted method. Pial arterioles were classified according to a centripetal ordering scheme (Strahler method modified according to diameter) from the smallest order 1 to the largest order 5 arterioles in the preparation. A distinction between arteriolar segments and elements was used to express the series-parallel features of the pial arteriolar networks. A connectivity matrix was used to describe the connection of blood vessels from one order to another. Results: The arterioles were assigned 5 orders of branching by Strahler’s ordering scheme, from order 1 (diameter: 16.0 ± 2.5 µm) to order 5 (62 ± 5.0 µm). Order 1 arterioles gave origin to capillaries, assigned order 0. The diameter, length and branching of the 5 arteriolar orders grew as a geometric sequence with the order number in accordance with Horton’s law. The segments/elements ratio was the highest in order 4 and 3 arterioles, indicating the greatest asymmetry of ramifications. Finally, the branching vessels in the networks were described in details by the connectivity matrix. Fractal dimensions of arteriolar length and diameter were 1.75 and 1.78, respectively. Conclusions: The geometric characteristics of rat pial microcirculation indicate that distribution of vessels is fractal. The connectivity matrix allowed us to describe the number of daughter vessels spreading from parent vessels. This ordering scheme may be useful to describe vessel function, according to diameter, length and branching.
Effects of Ozone and Sodium Hypochlorite on Caries-Like Lesions in Dentin
Authors: Zaura E. , Buijs M.J. , ten Cate J.M.
Published: October 2007

The hypothesis that ozone promotes remineralization of dentinal lesions was tested in vitro. Artificial caries-like lesions in dentin were treated with ozone gas, with another potent oxidizer (sodium hypochlorite, NaOCl, 10%) or with water. The specimens were then remineralized and subsequently demineralized again. Mineral content was assessed by transverse microradiography. NaOCl-treated samples showed damaged surface and, after being remineralized, demineralized significantly more than water- or ozone-treated groups. No difference was found between ozone and water groups. The exposure to ozone had thus no effect on remineralization and subsequent demineralization of remineralized dentinal lesions.
Fibrinogen Apheresis in the Treatment of Peripheral Arterial Disease
Authors: Ramunni A. , Brescia P. , Quaranta D. , Plantamura M. , Ria R. , Coratelli P.
Published: October 2007

Background: Fibrinogen is mainly responsible for determining the viscosity of whole blood. In peripheral arterial disease (PAD) the fibrinogen concentration seems to affect the microcirculation flow. Aim: To study the effects of an abrupt reduction of fibrinogen on the hemodynamics of the lower extremities and the clinical picture of patients with PAD. Methods: Ten patients affected by various stages of PAD underwent 1 session of fibrinogen apheresis (TheraSorb, Miltenyi Biotec, Germany). Laboratory parameters of endothelial activation were assessed before and after the session, as well as walking distance (WD), the ankle-brachial index and laser Doppler flowmetry. Results: A significant reduction in the laboratory parameters was observed: fibrinogen (50%), total cholesterol (18%), LDL cholesterol (24%), sE-selectin (23%), sICAM-1 (19%) and sVCAM-1 (10%). The procoagulant factors, factor VIII and von Willebrand factor, did not vary significantly. Both pain-free and total WD were significantly improved (p < 0.003 and p <0.006, respectively), the ankle-brachial index remained unchanged, and laser Doppler flowmetry showed a modest but not significant increase. Conclusions: Fibrinogen apheresis allowed us to study the effects of an acute modification of fibrinogen in PAD, on both some aspects of the endothelial function and on the hemodynamics, demonstrating an improvement of WD and a minimal increase in the skin microcirculation.
Comparative Erythropoietin Receptor Binding Kinetics of C.E.R.A. and Epoetin-β Determined by Surface Plasmon Resonance and Competition Binding Assay
Authors: Jarsch Michael , Brandt Michael , Lanzendörfer Martin , Haselbeck Anton
Published: October 2007

C.E.R.A., a continuous erythropoietin (EPO) receptor activator, has been developed to provide stable maintenance of hemoglobin levels at once-monthly dosing intervals and smooth and steady anemia correction. The comparative EPO receptor binding properties of C.E.R.A. and epoetin-β were assessed by surface plasmon resonance using soluble recombinant EPO receptors and by competition binding on cultured UT-7 cells. Calculated equilibrium dissociation constants (surface plasmon resonance assay) for C.E.R.A. and epoetin-β were 140 and 2.9 nmol/l, respectively. Respective IC50 values (competition binding assay) were 200 and 1.5 nmol/l. Compared with epoetin-β, C.E.R.A. has ∼50- to 100-fold lower affinity for EPO receptor binding sites. Analysis of the equilibrium binding curves indicates that the difference in affinity is mainly due to slower association. The different receptor binding properties of C.E.R.A. may enable continuous stimulation of erythropoiesis and, combined with a long half-life and slow systemic clearance, permit administration at extended intervals.
Direct Injection of Calcitriol or Its Analog Improves Abnormal Gene Expression in the Hyperplastic Parathyroid Gland in Uremia
Authors: Shiizaki Kazuhiro , Fukagawa Masafumi , Yuan Qunsheng , Hatamura Ikuji , Nii-Kono Tomoko , Saji Fumie , Shigematsu Takashi , Akizawa Tadao
Published: October 2007

Aims: In this study, we investigated the effects of direct injection (DI) of calcitriol or maxacalcitol into the hyperplastic parathyroid gland (PTG) on altered gene expression related to the advanced status of secondary hyperparathyroidism (SHPT). Methods: Sprague-Dawley rats were 5/6-nephrectomized (uremic) or sham-operated (normal). In each uremic rat, one of the bilateral PTG was treated by DI of calcitriol (PTGCAL) or maxacalcitol (PTGOCT), and the other gland was treated with control solution (PTGCONT). The PTG were evaluated for levels of expression of various mRNA and immunohistochemical staining of proliferating cell nuclear antigen (PCNA). Results: Significant differences in levels of expression of mRNA and PCNA were confirmed between the uremic and normal groups. In PTGCAL and PTGOCT, expressions of almost all mRNA and PCNA were significantly improved; both agents were able to normalize the abnormalities of the uremic PTG, in contrast to the baseline and individual PTGCONT. However, the difference in effect between PTGCAL and PTGOCT was only small. Conclusion: Our results suggest that very high concentrations of calcitriol or maxacalcitol in the PTG improve abnormal gene expression and proliferation activity of parathyroid cells, and might explain the better control of SHPT using the DI technique.
Identification of a Novel Role of T Cells in Postnatal Vasculogenesis
Authors: Hur Jin , Yang Han-Mo , Yoon Chang-Hwan , Lee Choon-Soo , Park Kyung-Woo , Kim Ji-Hyun , Kim Tae-Youn , Kim Ju-Young , Kang Hyun-Jae , Chae In-Ho , Oh Byung-Hee , Park Young-Bae , Kim Hyo-Soo
Published: October 2007

Background—

The colony number of early endothelial progenitor cells (EPCs) has been used as a quantitative indicator of the number of EPCs in the blood or as a biological marker of cardiovascular diseases. In the present study, we found a subset of T cells that were localized at the center of the EPC colony and played a pivotal role in colony formation and differentiation of early EPCs.

Methods and Results—

We found that CD3
+
CD31
+
CXCR4
+
T cells (referred to as angiogenic T cells in the present study) constituted the center of EPC colonies during cultures of human peripheral blood mononuclear cells. These angiogenic T cells were required for colony formation and differentiation of early EPCs. They secreted high levels of angiogenic cytokines such as vascular endothelial growth factor, interleukin-8, and matrix metalloproteinases. Angiogenic T cells showed superior angiogenic potential to the other subset of T cells in the experiments with regard to Matrigel tube formation, adhesion, transendothelial migration, and collagen invasion assay, mainly through the stromal cell–derived factor 1/CXCR-4 axis. Furthermore, angiogenic T cells enhanced endothelial cell proliferation and function. In vivo study showed that angiogenic T cells play an important role in the process of vessel formation. Clinical study showed that the level of angiogenic T cells in the peripheral blood was well correlated with EPC colony numbers and had inverse relationships with age and the number of risk factors for coronary artery disease.

Conclusions—

These findings suggest that angiogenic T cells could be a potential therapeutic target for ischemic cardiovascular diseases.
Differing Pattern of Sympathoexcitation in Normal-Weight and Obesity-Related Hypertension
Authors: Lambert Elisabeth , Straznicky Nora , Schlaich Markus , Esler Murray , Dawood Tye , Hotchkin Elodie , Lambert Gavin
Published: October 2007

Hypertension in normal-weight and obese individuals is characterized by activation of the sympathetic nervous system. Measurement of spillover of the sympathetic transmitter, norepinephrine, to plasma indicates that the regional pattern of sympathetic activation in the 2 “variants” of essential hypertension differs, excluding the heart in obesity-related hypertension. Whether sympathetic nerve firing characteristics also differ is unknown. We studied multiunit and single fiber sympathetic nerve firing properties in patients with normal-weight hypertension and obesity-related hypertension, comparing these with nerve characteristics in normal-weight and obese people with normal blood pressure. Both normal-weight hypertensive (n=10) and obese hypertensive (n=14) patients had increased total multiunit muscle sympathetic nerve activity compared with the normal-weight (n=11) and obese (n=11) people with normal blood pressure (65±4 versus 47±6 bursts per 100 heartbeats,
P
<0.01 in the normal-weight groups and 68±4 versus 53±3 bursts per 100 beats,
P
<0.01 in the obese groups). Sympathetic activation in normal-weight hypertension was characterized by increased firing rate of single vasoconstrictor fibers (70±8 versus 28±3 spikes per 100 beats;
P
<0.001), increased firing probability per heartbeat (39±3% versus 20±3%;
P
<0.001), and higher incidence of multiple spikes per heartbeat (30±4% versus 17±4%;
P
<0.05). Sympathetic activation in obesity-related hypertension differed, involving recruitment of previously silent fibers, which fired at a normal rate. The pattern of sympathetic activation in normal-weight and obesity-related hypertension differs in terms of both the firing characteristics of individual sympathetic fibers and the sympathetic outflows involved. The underlying central nervous system mechanism and the adverse consequences of the 2 modes of sympathetic activation may differ.
A Study of Regional Precipitation Trends in Iceland Using a High-Quality Gauge Network and ERA-40
Authors: Crochet Philippe
Published: October 2007

The climatic variability and trends of precipitation in Iceland are examined for the period 1961–2000 using bias-corrected rain gauge data and precipitation forecasts from the 40-yr ECMWF Re-Analysis (ERA-40). Several quantities are studied: the monthly and annual precipitation amounts as well as the statistical characteristics of 12-hourly precipitation rate and the geometrical features of the precipitation fields. The study highlights the credibility of ERA-40 and its ability to capture in a realistic manner the climatic variability of precipitation in Iceland, despite local discrepancies related to the crude horizontal resolution of these data. The observed intra- and interannual variations in the precipitation characteristics can be linked to variations in size, location, and occurrence of the large-scale precipitation systems crossing Iceland that are in turn influenced by the strength of the North Atlantic Oscillation, especially in winter.