bluuebunny/crossref_metadata_2025 huggingface dataset:
Sublingual immunotherapy reduces allergic symptoms in a mouse model of rhinitis
Authors: Brimnes J. , Kildsgaard J. , Jacobi H. , Lund K.
Published: November 2006

Background
Sublingual immunotherapy (SLIT) is a clinically effective treatment in both pollen and house dust mite‐induced rhinitis and asthma. However, the mechanisms by which this is accomplished are not clear.

Objective
The objective of the current study was to establish a mouse model of rhinitis in order to study the effect and mechanisms of SLIT.

Methods
Mice were sensitized by intraperitoneal injections of alum‐adsorbed Phleum pratense extract. Sensitized mice were SLIT‐treated and subsequently challenged intranasally and analysed for clinical symptoms, antibody levels, eosinophilia and T cell response.

Results
Intranasal challenge of sensitized mice led to the development of rhinitis characterized by significantly increased sneezing and influx of eosinophils into the nose. Levels of specific IgE were fivefold increased in nasopharyngeal lavage (NAL) fluid and more than doubled in serum. Furthermore, a T‐helper type 2 (Th2) like T cell response was observed in local draining lymph nodes. SLIT treatment of sensitized mice reduced sneezing, eosinophilia and IgE levels in the NAL by more than 50%. Moreover, serum levels of IgE and IgG1 as well as T cell response in the draining lymph nodes were also significantly reduced. Treatment for a shorter time or with a lower dose only led to minor reductions of the clinical and immunological parameters, indicating that the effect of SLIT is time and dose dependent.

Conclusion
In the present study, we have established a mouse model displaying the hallmarks of allergic rhinitis using a clinically relevant allergen. Using this model, we have demonstrated that SLIT treatment is able to reduce allergic symptoms in a time‐ and dose‐dependent manner.
Effect of a bone marrow microenvironment on the ex‐vivo expansion of umbilical cord blood progenitor cells
Authors: GALAN I. , DELEON J. A. , DIAZ L. , HONG J.‐S. , KHALEK N. , MUNOZ‐FERNANDEZ M.A. , SANTOLAYA‐FORGAS J.
Published: November 2006

Progenitor cells (CD34+) can be isolated from umbilical cord blood and used to correct or reconstitute various cell lines within the haematopoietic and endothelial cell lineage. The main disadvantage of this procedure relates to the low volume of blood that can be collected after the umbilical cord has been clamped, which limits the number of progenitor cells available for treatment. This limitation, however, can be overcome by expanding CD34+ cells ex vivo. Our aim was to perform a controlled study to determine if the ex‐vivo proliferation of umbilical cord CD34+ cells is enhanced when they are placed in a system that mimics the bone marrow microenvironment. For this purpose, CD34+ cells were isolated from umbilical cord blood using a magnetic cell sorting kit and seeded in platforms containing different cocktails of cytokines with and without a three‐dimensional (3D) biomatrix. Results from this study suggest that the number of viable cells can double after 1 week in any of the culture platforms and that the 3D biomatrix does not enhance cell proliferation.
Bacteria in oral secretions of an endophytic insect inhibit antagonistic fungi
Authors: CARDOZA YASMIN J. , KLEPZIG KIER D. , RAFFA KENNETH F.
Published: November 2006

Abstract1. Colonisation of host trees by an endophytic herbivore, the spruce beetle,Dendroctonus rufipennis, is accompanied by invasion of its galleries by a number of fungal species. Four of these associated species were identified asLeptographium abietinum,Aspergillus fumigatus,Aspergillus nomius, andTrichoderma harzianum.

2. TrichodermaandAspergillussignificantly reduced spruce beetle survival and reproduction in controlled assays.

3. A previously undescribed behaviour was observed, in which spruce beetle adults exuded oral secretions, especially within fungus‐pervaded galleries.

4. These oral secretions inhibited the growth of fungi exceptA. nomius, and disrupted the morphology of the latter. Administration of these secretions indicated a dose‐dependent inhibitory effect.

5. Oral secretions cultured on microbiological media yielded substantial bacterial growth.

6. Filter‐sterilised secretions failed to inhibit fungal growth, evidence that the bacteria are responsible for the antifungal activity.

7. Nine bacterial isolates belonging to the Actinobacteria, Firmicutes, Gammaproteobacteria, and Betaproteobacteria taxa were obtained from the secretions.

8. Bacterial isolates showed species‐specific inhibitory activity against the four fungi antagonistic to spruce beetle. The bacterium with the strongest fungal inhibition activity was the actinomyceteMicrococcus luteus.

9. The production of bark beetle secretions containing bacteria that inhibit fungal growth is a novel finding. This suggests an additional level of complexity to ecological associations among bark beetles, conifers, and microorganisms, and an important adaptation for colonising subcortical tissue.
Essential fatty acids and phosphorus in seston from lakes with contrasting terrestrial dissolved organic carbon content
Authors: GUTSEIT KELLY , BERGLUND OLOF , GRANÉLI WILHELM
Published: November 2006

1. It is often assumed that lakes highly influenced by terrestrial organic matter (TOM) have low zooplankton food quality because of elemental and/or biochemical deficiencies of the major particulate organic carbon pools. We used the biochemical [polyunsaturated fatty acids, especially eicosapentaenoic acid (EPA) – 20:5ω3] and elemental (C : P ratio) composition of particulate matter (PM) as qualitative measures of potential zooplankton food in two categories of lakes of similar primary productivity, but with contrasting TOM influence (clear water versus humic lakes).

2. C : P ratios (atomic ratio) in PM were similar between lake categories and were above 400. The concentration (μg L−1) and relative content (μg mg C−1) of EPA, as well as the particulate organic carbon concentration, were higher in the humic lakes than in the clear‐water lakes.

3. Our results show high fatty acid quality of PM in the humic lakes. The differences in the biochemical quality of the potential zooplankton food between lake categories can be attributed to the differences in their phytoplankton communities.

4. High biochemical quality of the food can result in high efficiency of energy transfer in the food chain and stimulate production at higher trophic levels, assuming that zooplankton are able to ingest and digest the resource available.
Upward range extension of Andean anurans and chytridiomycosis to extreme elevations in response to tropical deglaciation
Authors: SEIMON TRACIE A. , SEIMON ANTON , DASZAK PETER , HALLOY STEPHAN R.P. , SCHLOEGEL LISA M. , AGUILAR CÉSAR A. , SOWELL PRESTON , HYATT ALEX D. , KONECKY BRONWEN , E SIMMONS JOHN
Published: November 2006

High‐alpine life forms and ecosystems exist at the limits of habitable environments, and thus, are especially sensitive to environmental change. Here we report a recent increase in the elevational limit of anurans following glacial retreat in the tropical Peruvian Andes. Three species have colonized ponds in recently deglaciated terrain at new record elevations for amphibians worldwide (5244–5400 m). Two of these species were also found to be infected with Batrachochytrium dendrobatidis (Bd), an emerging fungal pathogen causally associated with global amphibian declines, including the disappearance of several Latin American species. The presence of this pathogen was associated with elevated mortality rates of at least one species. These results represent the first evidence of upward expansion of anurans to newly available habitat brought about by recent deglaciation. Furthermore, the large increase in the upper limit of known Bd infections, previously reported as 4112 m in Ecuador, to 5348 m in this study, also expands the spatial domain of potential Bd pathogenicity to encompass virtually all high elevation anuran habitats in the tropical Andes.
Comparison of carbon dioxide fluxes over three boreal black spruce forests in Canada
Authors: BERGERON ONIL , MARGOLIS HANK A. , BLACK T. ANDREW , COURSOLLE CAROLE , DUNN ALLISON L. , BARR ALAN G. , WOFSY STEVEN C.
Published: November 2006

Although mature black spruce forests are a dominant cover type in the boreal forest of North America, it is not clear how their carbon (C) budgets vary across the continent. The installation of an eddy covariance flux tower on an Old Black Spruce (OBS) site in eastern Canada (EOBS, Québec) provided a first opportunity to compare and contrast its annual (2004) and seasonal C exchange with two other pre‐existing OBS flux sites from different climatic regions located in Saskatchewan [Southern OBS (SOBS)] and Manitoba [Northern OBS (NOBS)]. Although there was a relatively uniform seasonal pattern of net ecosystem productivity (NEP) among sites, EOBS had a lower total annual NEP than the other two sites. This was primarily because warmer soil under a thicker snowpack at EOBS appeared to increase winter C losses and low light suppressed both NEP and gross ecosystem productivity (GEP) in June. Across sites, greater total annual GEP and ecosystem respiration (R) were associated with greater mean annual air temperatures and an earlier beginning of the growing season. Also, GEP at all three sites showed a stronger relationship with air temperature in spring and early summer compared with later in the growing season, highlighting the importance of springtime conditions to the C budget of these boreal ecosystems. The three sites had different parameter estimates describing the responses of R and GEP at the half hour time scale to near surface temperature and light, respectively. On the other hand, the responses of both R and GEP to temperature at the monthly scale did not differ among sites. These results suggest that a general parameterization could be sufficient at coarse time resolutions to model the response of C exchange to environmental factors of mature black spruce forests from different climatic regions.
Contrasting responses of migration strategies in two European thrushes to climate change
Authors: RIVALAN PHILIPPE , FREDERIKSEN MORTEN , LOL̈S GREGOIRE , JULLIARD ROMAIN
Published: November 2006

Migration is a widespread strategy that enables animals to escape harsh winter conditions. It has been well documented that migration phenology in birds is changing in response to recent climate warming in the northern hemisphere. Despite the existence of large temporal and geographical scale ringing data on birds in Europe, changes in migration strategies in relation to climate warming have not been well studied, mainly because of a lack of appropriate statistical methods. In this paper, we develop a method that enables us to investigate temporal changes in migration strategies from recoveries of dead ringed birds. We estimated migration probability as the ratio between recovery probabilities of conspecific birds originating from different countries but potentially wintering in the same country. We applied this method to two European thrushes: the entirely migrant redwingTurdus iliacus, and the partially migrant blackbirdT. merula. We tested for an immediate and a 1‐year lagged relationship between our migration probability and climatic covariates (i.e. mean winter temperature in France and the North Atlantic Oscillation). Using ringing‐recovery data collected in Finland, Germany, Switzerland and France from 1970 to 1999, we detected contrasting responses in these two species, likely related to their different migratory behaviours. Both species showed a decline in the probability for northern and eastern birds to winter in France. The entirely migratory redwing exhibited a year‐to‐year plastic response to climate, whereas the decline in the partially migrant blackbird was smooth, suggesting underlying genetic processes. The proposed method, thus, allows us to identify useful indicators of climatic impacts on migration strategies, as well as highlighting differences between closely related species.
Rhizospheric and heterotrophic components of soil respiration in six Chinese temperate forests
Authors: WANG CHUANKUAN , YANG JINYAN
Published: November 2006

Partitioning soil respiration (RS) into heterotrophic (RH) and rhizospheric (RR) components is an important step for understanding and modeling carbon cycling in forest ecosystems, but few studies on RR and RH exist in Chinese temperate forests. In this study, we used a trenching plot approach to partition RS in six temperate forests in northeastern China. Our specific objectives were to (1) examine seasonal patterns of soil surface CO2 fluxes from trenched (RT) and untrenched plots (RUT) of these forests; (2) quantify annual fluxes of RS components and their relative contributions in the forest ecosystems; and (3) examine effects of plot trenching on measurements of RS and related environmental factors. The RT maximized in early growing season, but the difference between RUT and RT peaked in later summer. The annual fluxes of RH and RR varied with forest types. The estimated values of RH for the Korean pine (Pinus koraiensis Sieb. et Zucc.), Dahurian larch (Larix gmelinii Rupr.), aspen‐birch (Populous davidiana Dode and Betula platyphylla Suk.), hardwood (Fraxinus mandshurica Rupr., Juglans mandshurica Maxim. and Phellodendron amurense Rupr.), Mongolian oak (Quercus mongolica Fisch.) and mixed deciduous (no dominant tree species) forests averaged 89, 196, 187, 245, 261 and 301 g C m−2 yr−1, respectively; those of RR averaged 424, 209, 628, 538, 524 and 483 g C m−2 yr−1, correspondingly; calculated contribution of RR to RS (RC) varied from 52% in the larch forest to 83% in the pine forest. The annual flux of RR was strongly correlated to biomass of roots <0.5 cm in diameter, while that of RH was weakly correlated to soil organic carbon concentration at A horizon. We concluded that vegetation type and associated carbon metabolisms of temperate forests should be considered in assessing and modeling RS components. The significant impacts of changed soil physical environments and substrate availability by plot trenching should be appropriately tackled in analyzing and interpreting measurements of RS components.
Bactericidal efficacy of Er,Cr:YSGG laser irradiation against Enterococcus faecalis compared with NaOCl irrigation: an ex vivo pilot study
Authors: Eldeniz A. U. , Ozer F. , Hadimli H. H. , Erganis O.
Published: November 2006

Aim  To compare the efficacy of a standard NaOCl irrigation procedure with that of Er,Cr:YSGG laser irradiation in contaminated root canals having small and large apical foramina.

Methodology  Forty root canals of extracted central incisor teeth with straight roots were chosen so that their apical foramina just permitted the tip of a size 20‐K file to pass through. The canals were then enlarged with files to size 60 and randomly divided into four groups of 10 teeth each. The apical foramina of one group were widened further so that the tip of a size 45‐K file could just pass through. After sterilization, all roots were inoculated with Enterococcus faecalis for 48 h at 37 °C. The first group was used as a control, the second group was irrigated with 3% NaOCl solution for 15 min, and the last two groups having different sizes of apical foramina were irradiated with the Er,Cr:YSGG laser at output power from 0.5 W, with 20% air and water levels. The disinfecting efficacy of the groups was tested by collecting dentine chips from the inner canal walls of the specimens and counting viable E. faecalis on Mueller–Hinton agar plates.

Results  The differences in the mean number of viable colonies between the control and laser groups were statistically significant (P < 0.05). The control specimens had the highest number of microorganisms (153 × 103 ± 39 × 103). Complete sterilization was achieved in the 3% NaOCl group. The mean colony forming units (CFU) values obtained after Er,Cr:YSGG laser irradiation were 6.6 × 103 CFU and 6.5 × 103 CFU in root canals having large and small apical foramina respectively.

Conclusion  In teeth with straight roots the Er,Cr:YSGG laser reduced the viable microbial population in root canals with small and large apical foramina but did not eradicate all bacteria. Three percent NaOCl inhibited the growth of E. faecalis and effectively sterilized all root canals.
Intraosseous schwannoma mimicking a periapical lesion on the adjacent tooth: case report
Authors: Martins M. D. , Taghloubi S. A. , Bussadori S. K. , Fernandes K. P. S. , Palo R. M. , Martins M. A. T.
Published: November 2006

Aim  To present an additional case of intraosseous schawannoma involving the apical area in the mandibular alveolar bone mimicking an inflammatory periapical lesion.

Summary  This article describes a case of schwannoma periapically located mimicking an inflammatory periapical lesion in the mandible of a 34‐year‐old female. Diagnostic and therapeutic problems can occur when this lesion is misinterpreted as being endodontic in origin. The diagnosis, radiograph, immunohistochemical aspects and treatment are also discussed.

Key learning points 

Intraosseous schwannoma is a rare unilocular radiolucency that when located periapically could be misdiagnosed as an endodontic lesion and result in unnecessary root canal treatment.

The vitality of the pulp is an important test to exclude lesions of inflammatory origin.

Histological examination is important to establish the diagnosis of lesions in the periradicular region.
Calcium hydroxide barrier over the apical root‐end of a type III dens invaginatus after endodontic and surgical treatment
Authors: Soares J. , Santos S. , Silveira F. , Nunes E.
Published: November 2006

Aim  To report the simultaneous endodontic and surgical treatment of a tooth associated with Oehlers type III dens invaginatus and a persistent periapical lesion, which comprised root‐end resection, root‐end filling and application of a calcium hydroxide barrier placed on the resected dentine surface.

Summary  Three root canals were identified in a tooth with a type III dens invaginatus, which presented with a necrotic pulp, wide foraminal opening and extensive periapical lesion, and with a previous history of acute abscess, intracanal exudate and fistula. After root canal preparation followed by intracanal application of calcium hydroxide pastes, the clinical–pathological status persisted. After periapical curettage and root‐end resection, the root canals were filled, followed by root‐end filling with Sealer 26 mixed with zinc oxide powder to a clay‐like consistency. Calcium hydroxide paste was then applied over the exposed dentinal surface forming a covering over the root apex. At the 20‐month follow‐up examination the patient had no symptoms and no fistula; advanced periapical bone repair was obvious on the radiograph.

Key learning points

• Because of the variable morphology and extent of invagination, type III dens invaginatus represents a challenge for conventional treatment, often leading to the need for a surgical approach.

• Sealer 26 thickened with zinc oxide powder provided satisfactory clinical properties for use as a root‐end filling material.

• Application of a calcium hydroxide barrier over the resected root‐end is a potential treatment option to encourage tissue repair.
Potential migration routes and barriers for vascular plants of the Neotropical Guyana Highlands during the Quaternary
Authors: Rull Valentí , Nogué Sandra
Published: November 2006

Aim  To reconstruct in detail the potential migration routes and barriers for vascular plants from the summits of the Guyana mountains during the Quaternary, in order to test the possibility of migration among them during the glaciations. These changes in connectivity are predicted based on the altitudinal migration of plant communities associated with glacial cooling. To examine the effects of these cycles, the extent of the potential biotic interchange and its influence on patterns of endemism was modelled.

Location  The summits of the tepuis or table mountains of the Neotropical Guyana Highlands, which constitute the peculiar and discontinuous Pantepui phytogeographical province (total surface 5000 km2, altitudinal range 1500–3014 m a.s.l.), and is characterized by a unique and diverse flora with a high degree of endemism.

Methods  GIS‐based palaeotopographical reconstruction using a high‐precision digital elevation model, combined with phytogeographical analysis by means of a data base built up from the Flora of the Venezuelan Guyana, which includes the geographical and altitudinal ranges for each Pantepui species.

Results  During the Last Glacial Maximum, which serves as a representative of a standard Quaternary glaciation, most migration pathways among tepuis were open for species with lower altitudinal levels (LAL) ≤ 1500 m (1678 species or c. 69% of the total Pantepui species), and closed for species with LAL ≥ 2300 m altitude (c. 3%). The species in between these altitudes have intermediate migratory possibilities, depending on the district and the tepui considered. If these local factors are considered, the number of species with no possibility of glacial interchange increases to 202 or c. 8% of the total. The strongest topographical barrier separated eastern locations above 1600–1700 m elevation from all others. The highest possibility of interchange was among the tepuis of the eastern sector, in which internal topographical barriers were only effective for species with LALs at or above 1900 m.

Main conclusions  The Quaternary evolution of the vascular flora from the Guyana Highlands took place in a predominantly migration‐prone, glacial‐era landscape, in which more than 70% of the flora (maximum estimate) was able to move from one tepuian district to another, thanks to the downward bioclimatic shift caused by cooling. Interglacials were too short to drive significant evolutionary diversification. A number of present high‐altitude local endemics are species that were unable to migrate, even during glaciations. However, some endemic species do appear to have been able to migrate among regions, suggesting that topographical isolation alone is not enough to explain patterns of endemism. Other factors such as tepui summit area, habitat heterogeneity or pre‐Quaternary evolution are considered. These studies should be complemented with palaeoecological and phylogeographical surveys.
Marine biogeography and ecology: invasions and introductions
Authors: Briggs John C.
Published: November 2006

Although biogeography and ecology had previously been considered distinct disciplines, this outlook began to change in the early 1990s. Several people expressed interest in creating a link that would help ecologists become more aware of external influences on communities and help biogeographers realize that distribution patterns had their genesis at the community level. They proposed an interdisciplinary approach called macroecology. This concept has been aided by the advent of phylogeography, for a better knowledge of genetic relationships has had great interdisciplinary value. Two areas of research that should obviously benefit from a macroecological approach are: (1) the question of local vs. regional diversity and (2) the question of whether invader species pose a threat to biodiversity. The two questions are related, because both deal with the vulnerability of ecosystems to penetration by invading species. Biogeographers, who have studied the broad oceanic patterns of dispersal and colonization, tend to regard isolated communities as being open to invasion from areas with greater biodiversity. It became evident that many wide‐ranging species were produced in centres of origin, and that the location of communities with respect to such centres had a direct effect on the level of species diversity. Ecologists, in earlier years, thought that a community could become saturated with species and would thereafter be self‐sustaining. But recent research has shown that saturation is probably never achieved and that the assembly of communities and their maintenance is more or less dependent on the invasion of species from elsewhere. The study of invasions that take place in coastal areas, usually the result of ship traffic and/or aquaculture imports, has special importance due to numerous opinions expressed by scientists and policy‐makers that such invasions are a major threat to biodiversity. However, none of the studies so far conducted has identified the extinction of a single, native marine species due to the influence of an exotic invader. Furthermore, fossil evidence of historical invasions does not indicate that invasive species have caused native extinctions or reductions in biodiversity.
Molecular phylogeography of the fruit bat genusMelonycterisin northern Melanesia
Authors: Pulvers Jeremy N. , Colgan D. J.
Published: November 2006

Aim To investigate patterns of genetic divergence between populations of the fruit bat genusMelonycterisDobson 1877in relation to the possible effects on dispersal of the geological history of water barriers within and between northern Melanesian archipelagos.

Location The genus is found only in the Bismarck Archipelago and Solomon Islands of northern Melanesia.

Methods Up to 935 aligned bases of cytochromeband cytochromecoxidase subunit I DNA sequences were determined for specimens of most species and subspecies ofMelonycteris. Measures of genetic distance, analysis of molecular variation and phylogenetic investigations (using maximum parsimony, maximum likelihood and Bayesian approaches) were conducted to assess the evolutionary relationships amongst populations.

Results The deepest divergences withinMelonycterisseparate the genus into two reciprocally monophyletic clades from first, the Bismarck Archipelago, and secondly, the Solomon Islands. Within the Solomon Islands, five major clades received strong support. Listed in a generally north‐western to south‐eastern direction these were: (1) specimens from Choiseul and Santa Isabel; (2) specimens from New Georgia and Kolombangara; (3) specimens from Malaita; (4) specimens from Guadalcanal; and (5) specimens from Makira. Outgroup rooting suggested that the clade from Makira was the most basal within the Solomon Islands, being shown as the sister group to all otherMelonycterisfrom this archipelago.

Main conclusions Patterns of genetic variation withinMelonycteriswere generally consistent, given current knowledge of northern Melanesian geological history, with the hypothesis that the dispersal of these fruit bats is strongly inhibited by water barriers. Within the Solomon Islands the main genetic clades were each restricted to a single island or to a group of islands that are thought to have belonged to larger landmasses (Greater Gatumbangara and Greater Bukida) formed by land bridges during the Pleistocene. The high genetic distance between specimens from the Bismarck Archipelago and from the Solomon Islands reflects the persistently large geographic distance between these archipelagos. The unexpected phylogenetic position of the Makira specimens suggests either that this island was the first colonized byMelonycterisin the Solomon Islands or that this population is the relict of a clade that was previously more widely distributed.
Analysis of the incidence of infectious pancreatic necrosis mortality in pedigreed Atlantic salmon, Salmo salar L., populations
Authors: Guy D R , Bishop S C , Brotherstone S , Hamilton A , Roberts R J , McAndrew B J , Woolliams J A
Published: November 2006

A total of 77 124 Atlantic salmon post‐smolts, representing 197 full‐sib families produced by 149 males and 197 females, experienced a field challenge from infectious pancreatic necrosis virus (IPNV), following transfer to three separate seawater sites. The first IPN mortality was observed 45 days after transfer, and the duration of the epidemic varied between 37 and 92 days among sites. Mortalities were traced to their parental families by PIT (Passive Integrated Transpondes) tag records and DNA genotyping. Full‐sib family mean incidence of mortality was calculated for each family on each site. Heritabilities were estimated based on the heterogeneity of chi‐square using incidence within half‐sib families and the variance in incidence among full‐sib families, both on the observed and underlying liability scale. The observed correlation among families across sites was used to estimate genetic correlations. The overall mortality rate was 10.8%, with only small differences between sites, ranging from 10.3% to 11.9%. Heritabilities on the liability scale were found to be moderate to strong, and ranged between 0.24 and 0.81, with a pooled estimate of 0.43, greater than is typically associated with disease traits. Genetic correlations among sites were all substantial, between 0.71 and 0.78, and indicated that a substantial component of the genetic variation displayed within sites was common to all. The results show that field challenges can yield very good genetic information on family differences in resistance, especially when replicated over sites, which may then be developed for use in selection for breeding strains of Atlantic salmon with greater resistance to IPN.
The Critical Period Hypothesis: Can It Explain Discrepancies in the Oestrogen‐Cognition Literature?
Authors: Sherwin B. B.
Published: November 2006

Although there is compelling evidence from small randomised controlled trials and cross‐sectional studies indicating that oestrogen helps to protect against cognitive ageing in women, the findings of the large, Women's Health Initiative Memory Study failed to support the earlier findings. The attempt to resolve these discrepancies led to the formulation of the Critical Period Hypothesis which holds that oestrogen has maximal protective benefits on cognition in women when it is initiated closely in time to a natural or surgical menopause but not when treatment is begun decades after the menopause. This article reviews the evidence from basic neuroendocrinology, from animal behavioural studies and from human studies that supports the critical period hypothesis. In view of the promise of this hypothesis and its considerable clinical implications, a direct test of its validity is warranted.
Different Neural Melatonin‐Target Tissues are Critical for Encoding and Retrieving Day Length Information in Siberian Hamsters
Authors: Teubner B. J. W. , Freeman D. A.
Published: November 2006

Siberian hamsters exhibit several seasonal rhythms in physiology and behaviour, including reproduction, energy balance, body mass, and pelage colouration. Unambiguous long‐ and short day lengths stimulate and inhibit reproduction, respectively. Whether gonadal growth or regression occurs in an intermediate day length (e.g. 14 h L : 10 h D; 14L), depends on whether the antecedent day lengths were shorter (10L) or longer (16L). Variations in day length are encoded by the duration of nocturnal pineal melatonin secretion, which is decoded at several neural melatonin target tissues to control testicular structure and function. We assessed participation of three such structures in the acquisition and retrieval of day length information. Elimination of melatonin signalling to the nucleus reuniens (NRe), but not to the suprachiasmatic nucleus (SCN) or paraventricular thalamus (PVt), interfered with the acquisition of a long day reproductive response, whereas the obscuring of melatonin signals to the SCN and the NRe, but not to the PVt, interfered with the photoperiod history response. The SCN and NRe contribute in different ways to the melatonin‐based system that mediates seasonal rhythms in male reproduction.
TcYSL3, a member of the YSL gene family from the hyper‐accumulator Thlaspi caerulescens, encodes a nicotianamine‐Ni/Fe transporter
Authors: Gendre Delphine , Czernic Pierre , Conéjéro Geneviève , Pianelli Katia , Briat Jean‐François , Lebrun Michel , Mari Stéphane
Published: November 2006

The two main features of plant hyper‐accumulator species are the massive translocation of heavy metal ions to the aerial parts and their tolerance to such high metal concentrations. Recently, several lines of evidence have indicated a role for nicotianamine (NA) in metal homeostasis, through the chelation and transport of NA–metal complexes. The function of transport of NA–metal chelates, required for the loading and unloading of vessels, has been assigned to the Yellow Stripe 1 (YSL)‐Like family of proteins. We have characterized three YSL genes in Thlaspi caerulescens in the context of hyper‐accumulation. The three YSL genes are expressed at high rates compared with their Arabidopsis thaliana homologs but with distinct patterns. While TcYSL7 was highly expressed in the flowers, TcYSL5 was more highly expressed in the shoots, and the expression of TcYSL3 was equivalent in all the organs tested. In situ hybridizations have shown that TcYSL7 and TcYSL5 are expressed around the vasculature of the shoots and in the central cylinder in the roots. The exposure to heavy metals (Zn, Cd, Ni) does not affect the high and constitutive expression of the TcYSL genes. Finally, we have demonstrated by mutant yeast complementation and uptake measurements that TcYSL3 is an Fe/Ni–NA influx transporter. This work provides therefore molecular, histological and biochemical evidence supporting a role for YSL transporters in the overall scheme of NA and NA–metal, particularly NA–Ni, circulation in a metal hyper‐accumulator plant.
Precursor binding to an 880‐kDa Toc complex as an early step during active import of protein into chloroplasts
Authors: Chen Kuan‐Yu , Li Hsou‐min
Published: November 2006

The import of protein into chloroplasts is mediated by translocon components located in the chloroplast outer (the Toc proteins) and inner (the Tic proteins) envelope membranes. To identify intermediate steps during active import, we used sucrose density gradient centrifugation and blue‐native polyacrylamide gel electrophoresis (BN‐PAGE) to identify complexes of translocon components associated with precursor proteins under active import conditions instead of arrested binding conditions. Importing precursor proteins in solubilized chloroplast membranes formed a two‐peak distribution in the sucrose density gradient. The heavier peak was in a similar position as the previously reported Tic/Toc supercomplex and was too large to be analyzed by BN‐PAGE. The BN‐PAGE analyses of the lighter peak revealed that precursors accumulated in at least two complexes. The first complex migrated at a position close to the ferritin dimer (approximately 880 kDa) and contained only the Toc components. Kinetic analyses suggested that this Toc complex represented an earlier step in the import process than the Tic/Toc supercomplex. The second complex in the lighter peak migrated at the position of the ferritin trimer (approximately 1320 kDa). It contained, in addition to the Toc components, Tic110, Hsp93, and an hsp70 homolog, but not Tic40. Two different precursor proteins were shown to associate with the same complexes. Processed mature proteins first appeared in the membranes at the same fractions as the Tic/Toc supercomplex, suggesting that processing of transit peptides occurs while precursors are still associated with the supercomplex.
Translation efficiencies of synonymous codons are not always correlated with codon usage in tobacco chloroplasts
Authors: Nakamura Masayuki , Sugiura Masahiro
Published: November 2006

Codon usage in chloroplasts is different from that in prokaryotic and eukaryotic nuclear genomes. However, no experimental approach has been made to analyse the translation efficiency of individual codons in chloroplasts. We devised an in vitro assay for translation efficiencies using synthetic mRNAs, and measured the translation efficiencies of five synonymous codon groups in tobacco chloroplasts. Among four alanine codons (GCN, where N is U, C, A or G), GCU was the most efficient for translation, whereas the chloroplast genome lacks tRNA genes corresponding to GCU. Phenylalanine and tyrosine are each encoded by two codons (UUU/C and UAU/C, respectively). Phenylalanine UUC and tyrosine UAC were translated more than twice as efficiently than UUU and UAU, respectively, contrary to their codon usage, whereas translation efficiencies of synonymous codons for alanine, aspartic acid and asparagine were parallel to their codon usage. These observations indicate that translation efficiencies of individual codons are not always correlated with codon usage in vitro in chloroplasts. This raises an important issue for foreign gene expression in chloroplasts.
Linkage disequilibria between human leucocyte antigen‐B and closely linked microsatellites in the Croatian population
Authors: Grubić Z. , Štingl K. , Žunec R. , Car H. , Čečuk‐Jeličić E. , Brkljačić‐Kerhin V.
Published: November 2006

The aim of the present study was to investigate polymorphism of D6S2927, STR_MICA, D6S2793, TNFa (D6S2792), TNFb and TNFd (D6S2789) microsatellites and linkage disequilibria between these loci and human leucocyte antigen (HLA)‐B (previously tested) for better characterisation of extended HLA haplotypes. A total of 176 healthy unrelated Croatians were studied using polymerase chain reaction amplification and electrophoresis on 6% polyacrylamide gel in ALFexpress sequencer. Eight HLA‐B/D6S2927 haplotypic associations (B*07/D6S2927‐4, B*08/D6S2927‐3, B*18/D6S2927‐3, B*27/D6S2927‐1, B*35/D6S2927‐5, B*38/D6S2927‐4, B*51/D6S2927‐2 and B*61/D6S2927‐1) showed strong association (P < 0.001, D > 0.5). Among 88 different HLA‐B/STR_MICA haplotypic associations, seven combinations (B*07/STR_MICA‐A5.1, B*08/STR_MICA‐A5.1, B*15/STR_MICA‐A5, B*18/STR_MICA‐A4, B*27/STR_MICA‐A4, B*38/STR_MICA‐A9 and B*51/STR_MICA‐A6) demonstrated high linkage (D≥ 0.3) with significant P value (P < 0.001). Strong associations were also observed for five HLA‐B/D6S2793 haplotypes (B*07/D6S2793‐CA17, B*08/D6S2793‐CA24, B*13/D6S2793‐CA18, B*14/D6S2793‐CA14 and B*27/D6S2793‐CA14). HLA‐B*08/TNFb3 and HLA‐B*50/TNFb7 were the strongest associations for HLA‐B/TNFb. Nine HLA‐B/TNFa combinations were observed with significant P value (B*07/TNFa11, B*08/TNFa2, B*13/TNFa7, B*18/TNFa10, B*27/TNFa6, B*37/TNFa9, B*38/TNFa10, B*39/TNFa13 and B*44/TNFa4). Out of six HLA‐B/TNFd haplotypic associations with strong D value, HLA‐B*08/TNFd2 and B*37/TNFd3 showed the highest statistical significance (P < 0.0001). These results provide data on the region around the HLA‐B that is very attractive because of its contribution to genetic susceptibility for many HLA‐associated diseases and therefore this information will help in all further HLA‐B locus–associated disease studies.
Associations of leptin gene polymorphisms with production traits in pigs
Authors: De Oliveira Peixoto J. , Facioni Guimarães S.E. , Sávio Lopes P. , Menck Soares M.A. , Vieira Pires A. , Gualberto Barbosa M.V. , De Almeida Torres R. , De Almeida e Silva M.
Published: November 2006

The associations of leptin (LEP) gene polymorphisms C798T, T2411C, T3266G and T3469C with production traits were investigated in a F2 pig population produced by divergent crosses. The statistical model included genotype, sex, batch and genotype by sex interaction as fixed effects and sire as random effect. Polymorphism C798T was associated with variation in total teat number (p < 0.02) and left teat number (p < 0.03), and polymorphism T3469C was associated with weight at 21 days (p < 0.03), 42 days (p < 0.05), 63 days (p < 0.02) and 77 days of age (p < 0.04) as well as feed intake (p < 0.01), average daily gain (p < 0.01), feed conversion (p < 0.01), bacon depth (p < 0.03) and slaughter weight (p < 0.03). Phenotypic associations were also performed by combining T3469C and C798T genotypes. Interaction between C798T genotypes and sex was observed for some traits. LEP genotypes had significant influence on performance traits, and can be considered as potential genetic markers for selection. However, these results have to be validated in commercial herds.
Heritability of hair whorl position on the forehead in Konik horses
Authors: Górecka A. , Słoniewski K. , Golonka M. , Jaworski Z. , Jezierski T.
Published: November 2006

There are studies on the relationship between the position and shape of hair whorls on bovine forehead and phenotypic traits. According to anecdotal beliefs by horse users and handlers, temperamental traits may be related to the position of hair whorls in horses. No previous research on the mechanisms of inheritance of hair whorls has been performed, so the aim of the present study was to determine the heritability of the position of the hair whorl on the forehead of Konik horses. The horses (n = 362) were classified into five groups based on the whorl position on forehead with respect to the top and bottom eye lines. The estimated heritability of hair whorl position was 0.753 (SE = 0.056). Heritability adjusted for the discontinuity of the trait was 0.836. The results show that hair whorl position in Konik Polski horses is highly heritable. The possible relationship between position of hair whorls on the forehead and other morphological traits needs further research and should be interpreted with caution.
Characterization of a line of pigs previously selected for increased litter size for RBP4 and follistatin
Authors: Blowe C.D. , Boyette K.E. , Ashwell M.S. , Eisen E.J. , Robison O.W. , Cassady J.P.
Published: November 2006

The objective of this study was to determine if selection response for increased litter size in pigs could be partially attributed to three type 1 marker loci coding for genes known to affect litter size: oestrogen receptor (ESR), retinol‐binding protein 4 (RBP4) and follistatin (FS). In the high litter size line (LS), pigs from the largest litters, based on number of pigs born alive (NBA), were retained to parent the next generation. A randomly selected control line (LC) was maintained. Gilts were reared in litters of 10 pigs or less to minimize maternal effects. Pigs were measured at generations 10–12. Additional traits scored were number of fully formed pigs (NFF) and number of mummified fetuses (MUM). Breeding values for NFF and NBA were greater (p < 0.05) in LS than LC in generations 11 and 12, but no significant line differences were found for MUM. The A allele of the ESR locus was fixed in both lines. After adjustment for effects of genetic drift, frequency of the two alleles segregating for the FS and RBP4 loci did not differ significantly between lines. No significant additive or dominance effects of the FS markers were detected for NFF, NBA and MUM in either LS or LC. Response to selection for increased litter size could not be attributed to effects at the ESR, RBP4 or FS loci.
SeagrassNet monitoring across the Americas: case studies of seagrass decline
Authors: Short Frederick T. , Koch Evamaria W. , Creed Joel C. , Magalhães Karine M. , Fernandez Eric , Gaeckle Jeffrey L.
Published: November 2006

Seagrasses are an important coastal habitat worldwide and are indicative of environmental health at the critical land–sea interface. In many parts of the world, seagrasses are not well known, although they provide crucial functions and values to the world's oceans and to human populations dwelling along the coast. Established in 2001, SeagrassNet, a monitoring program for seagrasses worldwide, uses a standardized protocol for detecting change in seagrass habitat to capture both seagrass parameters and environmental variables. SeagrassNet is designed to statistically detect change over a relatively short time frame (1–2 years) through quarterly monitoring of permanent plots. Currently, SeagrassNet operates in 18 countries at 48 sites; at each site, a permanent transect is established and a team of people from the area collects data which is sent to the SeagrassNet database for analysis. We present five case studies based on SeagrassNet data from across the Americas (two sites in the USA, one in Belize, and two in Brazil) which have a common theme of seagrass decline; the study represents a first latitudinal comparison across a hemisphere using a common methodology. In two cases, rapid loss of seagrass was related to eutrophication, in two cases losses related to climate change, and in one case, the loss is attributed to a complex trophic interaction resulting from the presence of a marine protected area. SeagrassNet results provide documentation of seagrass change over time and allow us to make scientifically supported statements about the status of seagrass habitat and the extent of need for management action.
In vitro and in vivo antifungal activity of cetrimide (cetyltrimethyl ammonium bromide) against fungal keratitis caused by Fusarium solani
Authors: Mahmoud Yehia A.‐G.
Published: November 2006

Mycotic keratitis is a devastating eye infection acquired after eye injury. Cetrimide at 15 and 20 mg ml−1 produced no surviving Fusarium solani growth with minimal inhibitory concentration value of 0.10 mg ml−1. Topical administration of three drops (0.3 ml) of cetrimide aqueous solution of 10 mg ml−1 at pH 6.4 three times daily succeeded to cure human severe resistant F. solani keratitis in a time course of <3 weeks, and with complete healing after 6 weeks. Cetrimide‐treated rabbit corneas section appeared with normal compact epithelium and endothelium with no vacuolation in Descemet's endothelial complex: an indication that cetrimide has no significant toxic effects. So, cetrimide at 10 mg ml−1 may be effective and safe topical therapy in patients with mycotic keratitis, especially F. solani ulcers. Currently, there is no antimycotic drug with a good corneal penetration, which is safe and has a fungicidal activity.
Elucidation of the molecular mechanism of platelet activation: Dense granule secretion is regulated by small guanosine triphosphate‐binding protein Rab27 and its effector Munc13‐4
Authors: Horiuchi Hisanori , Shirakawa Ryutaro , Kondo Hirokazu , Higashi Tomohito , Kawato Mitsunori , Kita Toru
Published: November 2006

Cardiovascular diseases such as myocardial and cerebral infarction are common critical diseases occurring more frequently in the elderly. The trigger of the diseases is platelet activation following plaque rupture or erosion. Investigation of the molecular mechanism in platelet activation has been exclusively performed pharmacologically. We have succeeded in establishing the granule secretion and aggregation assays using permeabilized platelets. These systems enabled us to examine the molecular mechanism in platelet activation with molecular biological and biochemical methods. Using these assay systems, we have been investigating the molecular mechanism of platelet activation. With a support grant from the Novartis Foundation for Gerontological Research, we found several molecules involved in the regulation. In this report, I present the progress in the research of the granule secretion mechanism in activated platelets, which was reported in the Japanese Geriatric Society Meeting in 2005.
Simple screening test for risk of falls in the elderly
Authors: Okochi Jiro , Toba Kenji , Takahashi Tai , Matsubayashi Kozo , Nishinaga Masanori , Takahashi Ryutaro , Ohrui Takashi
Published: November 2006

Background:  The aim of this study is to construct a simple screening test for the risk of falls in community‐dwelling elder persons.

Methods:  A total of 1378 community‐dwelling people aged 65 years and older in five different communities in Japan were asked to answer a self rated questionnaire including 22 items covering physical, cognitive, emotional and social aspects of functioning and environmental factors. At a six‐month follow‐up, the outcome of fall occurrence and the number of falls was ascertained by social workers, health visitors or nurses.

Results:  Five out of 22 items were selected using a logistic regression model. Using this five‐item version, a screening test was constructed, and at the best cut‐off point, the sensitivity and specificity were 68% and 70%, respectively. The validity of this scale was tested on persons with cognitive dysfunction.

Conclusion:  The simplicity and the predictive validity of the screening test support the use of this test in health check ups or general outpatient facilities.