bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering of bypass conduits to improve patency
Authors: Rashid S. T. , Salacinski H. J. , Fuller B. J. , Hamilton G. , Seifalian A. M.
Published: September 2004

Abstract.  For patients with severe coronary artery and distal peripheral vascular disease not amenable to angioplasty and lacking sufficient autologous vessels there is a pressing need for improvements to current surgical bypass options. It has been decades since any real progress in bypass material has reached mainstream surgical practice. This review looks at possible remedies to this situation. Options considered are methods to reduce prosthetic graft thrombogenicity, including endothelial cell seeding and developments of new prosthetic materials. The promise of tissue‐engineered blood vessels is examined with a specific look at how peptides can improve cell adhesion to scaffolds.
Endothelial markers in chronic heart failure: training normalizes exercise‐induced vWF release
Authors: Sabelis L. W. E. , Senden P. J. , Fijnheer R. , De Groot P. G. , Huisveld I. A. , Mosterd W. L. , Zonderland M. L.
Published: September 2004

Background  Chronic heart failure (CHF) is characterized by endothelial dysfunction. Vascular endothelium is important for control of haemostasis and vasoregulation. The aim of the present study was to investigate plasma levels of several endothelial markers and the exercise‐induced changes on these plasma levels in CHF patients. Subsequently, the effect of a 6‐month training programme on these markers is described.

Materials and methods  Twenty‐nine male CHF patients (NYHA II/III, age 60 ± 8 year, body mass index 26·7 ± 2·3 kg m−2, left ventricular ejection fraction 26·3–7·2%; mean ± SD) participated. Patients were randomly assigned to a training or control group. Training (26 weeks; combined strength and endurance exercises) was four sessions/week: two sessions supervised and two sessions at home. Before and after intervention, anthropometry, endothelial markers (haemostasis and vasoregulation), maximal workload and peak oxygen uptake were assessed.

Results  Physical training positively affected maximal workload. Plasma levels of endothelial markers were not affected by physical training and not related to exercise tolerance. After training, stimulated (maximal exercise) plasma von Willebrand Factor (vWF) release was present, whereas at baseline this release was absent.

Conclusion  Physical training led to normalization of the stimulated plasma vWF release. Plasma levels of other endothelial markers were not affected by physical training either at rest or under stimulated (maximal exercise) conditions.
Do gene–environment interactions influence fasting plasma lipids? A study of twins
Authors: Greenfield J. R. , Samaras K. , Jenkins A. B. , Kelly P. J. , Spector T. D. , Campbell L. V.
Published: September 2004

Background  The aims of this study were to determine the influence of smoking, alcohol consumption, physical activity and hormone replacement therapy (HRT) on lipids, independently of genetic factors, and to detect whether gene–environment interactions influence these associations.

Materials and methods  Fasting plasma total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, apolipoproteins AI and B and lipoprotein(a) were measured in 685 female twins (96 monozygotic, 230 dizygotic pairs and 33 singletons).

Results  Smokers had higher triglyceride and lower HDL cholesterol levels than never‐smokers (P < 0·001). After controlling for genetic influences, smoking accounted for 0·35 mmol L−1 and 0·22 mmol L−1 differences in triglyceride and HDL cholesterol levels, respectively (P < 0·005), remaining significant after excluding alcohol‐discordant twin pairs. In a gene–environment interaction analysis, the association between smoking and triglycerides was exaggerated in subjects at high genetic risk of hypertriglyceridaemia (interaction P = 0·04). All levels of alcohol consumption were associated with higher HDL cholesterol levels than abstinence, but only moderate alcohol consumers had lower LDL cholesterol and triglyceride levels. In monozygotic twins concordant for smoking, an alcohol intake > 10 units week−1 accounted for a 0·32 mmol L−1 difference in LDL cholesterol, independently of genetic effects (P = 0·04). In postmenopausal women, those using HRT had 0·54 mmol L−1 lower LDL cholesterol and 0·21 µmol L−1 lower lipoprotein(a) levels than nonusers (P < 0·001 and P = 0·04, respectively); these differences were attenuated after accounting for genetic effects in monozygotic twins. Although physically active subjects had higher levels of HDL cholesterol than nonactive subjects, this was nonsignificant after adjusting for genetic factors.

Conclusions  Smoking‐induced aberrations in HDL cholesterol and triglycerides and alcohol‐related differences in LDL cholesterol were independent of genetic influences. The association between smoking and hypertriglyceridaemia was accentuated in high genetic risk individuals.
Precocious puberty at an endocrine centre in Jordan
Authors: Taher B. M. , Ajlouni H. K. , Hamamy H. A. , Shegem N. S. , Madanat A. Y. , Ajlouni K. M.
Published: September 2004

Background  Data from developed countries about precocious puberty are abundant; data from developing countries are limited. Causes are different, and diagnostic and treatment possibilities are very expensive. The present study aimed to display the spectrum of initial presentation and aetiology among children with precocious puberty and to assess any association between th e clinical features and the underlying cause of the condition.

Patients and method  Forty‐three girls and seven boys with precocious puberty were diagnosed at the Endocrine Clinic of Jordan University Hospital and at The National Center for Diabetes, Endocrinology and Genetics, Amman, Jordan, between the 1984 and 2003.

Results  Mean age for the girls with precocious puberty was 4·1 years ± 2·5 SD and for the boys was 2·4 years ± 1·9 SD. Among the girls, 21% presented with breast development only, 9% with pubic hair appearance only and 70% with multiple signs. All the boys presented with pubic hair appearance and enlarged genitalia. Organic causes for precocious puberty were detected in 42% of the girls and in all the boys. Idiopathic precocious puberty was more common among the girls presenting with breast development only (89%) compared with those presenting with multiple presenting signs (50%), and also was more common among girls presenting between 6 and 8 years (82%) than among those presenting < 6 years of age (42%). Congenital adrenal hyperplasia was diagnosed in four boys and four girls, and hypothyroidism in three girls.

Conclusion  Precocious puberty in the girls was usually of idiopathic origin when it presented with breast development only and at age older than 6 years. Congenital adrenal hyperplasia and hypothyroidism could represent important causes for precocious puberty in our community.
Resistance and resilience of stream insect communities to repeated hydrologic disturbances after a wildfire
Authors: Vieira Nicole K. M. , Clements William H. , Guevara Lynette S. , Jacobs Brian F.
Published: September 2004

1. Wildfires are often followed by severe, sediment‐laden floods in burned catchments. In this study, we documented resistance and resilience of stream insect communities to repeated postfire flash floods in a ‘burned stream’. We employed a before‐after‐control‐impact (BACI) design, where communities in comparable reaches of a burned stream and a reference stream were sampled from 2 years before, to 6 years after, a crown wildfire in north‐central New Mexico.

2. The first 100‐year flood following the 1996 Dome wildfire reduced total insect density and taxon richness to near zero in the burned stream. Despite showing low resistance, density returned rapidly to prefire levels because of colonisation by simuliids, chironomids and the mayfly Baetis tricaudatus. In general, taxa that were generalist feeders (collectors) with strong larval dispersal dominated communities in early postfire years with repeated, moderate flash floods.

3. Taxon richness and community composition were less resilient to postfire hydrologic disturbances. Taxon richness did not recover until floods dampened 4 years after the fire. Despite hydrologic recovery, composition in the burned stream still differed from prefire and reference stream compositions after 6 years postfire. A unique assemblage, dominated by taxa with strong larval or adult dispersal, was established after flash floods abated. Specialist feeders (shredders and grazers) that were common in prefire years were reduced or absent in the postfire assemblage.

4. Community succession in the burned stream was explained by the interaction between species traits, geographic barriers to colonisation and hydrologic conditions after the fire. Comparable changes in insect density, taxon richness, community composition and trait representation were not found in the reference stream, providing strong evidence that repeated postfire flash floods shaped community responses in the burned stream.
Contradictory results from different methods for measuring direction of insect flight
Authors: Macneale Kate H. , Peckarsky Barbara L. , Likens Gene E.
Published: September 2004

1. Stream ecologists have been puzzled by the apparent paradox that invertebrate populations persist in headwater streams despite the high frequency with which individuals drift downstream. To resolve this ‘drift paradox’, directions and distances of both larval and adult movement must be identified. Using over 50 interception traps in combination with results from several mark–capture experiments using 15N as a label, we tested the assumption that interception traps accurately represent the ultimate direction of adult insect flight.

2. In several streams in the Hubbard Brook Experimental Forest, 76% of 15N‐labelled stoneflies (Leuctra ferruginea) had flown upstream from where they emerged to where they were captured. In contrast, over 60% of stoneflies were flying downstream when captured, i.e. on the upstream side of an interception trap.

3. The instantaneous direction, as indicated by the side of the interception trap on which they were captured, indicated the ultimate flight direction for fewer than 1/3 of the individuals captured. Thus, such traps did not accurately reflect the ultimate flight patterns of individuals, as indicated by mark–capture data.

4. Conclusions drawn from interception trap counts regarding the direction of movement and the distribution and persistence of populations may need to be re‐evaluated. We suggest that better tracking methods, including mass mark–capture studies using stable isotopes, be used to evaluate the potentially complex patterns of adult insect movement and the consequences of that movement for individuals and populations.
A deep maximum of green sulphur bacteria (‘Chlorochromatium aggregatum’) in a strongly stratified reservoir
Authors: Chapin Bridgett R. K. , DeNoyelles Frank , Graham David W. , Smith Val H.
Published: September 2004

1. Fine‐scale physical and chemical gradients and deep photosynthetic microbial populations were assessed to provide an initial characterisation of a small, thermally stratified reservoir (Cross Reservoir, Kansas, U.S.A.) and its deep chlorophyll maxima (DCM). Factors were identified that may affect vertical positioning of subepilimnetic photosynthetic sulphur bacteria (PSB) in lakes.

2. Results indicate that Cross Reservoir is a mesotrophic, dimictic lake with large subepilimnetic chlorophyll maxima containing dense layers of PSB. Characteristics of the deep PSB community of Cross Reservoir strongly correlate with both light and nutrient gradients.

3. The deep bacterial community mostly contained single‐celled and aggregating green sulphur bacteria, specifically free‐livingChlorobium limicolaand the conspicuous motile ectosymbiotic consortium known as ‘Chlorochromatium aggregatum’. The bacteria were within the anaerobic hypolimnion, beneath a metalimnetic plate ofCryptomonasspp. and within very low sulphide and light conditions [mean of 67 μgS L−1and 0.05% photosynthetically active radiation (PAR)]. Pigment concentrations and fluorescence trends indicate that the bacteria made up a larger proportion of the DCM biomass than did phytoplankton in 1996.

4. Cross Reservoir shares characteristics with natural lakes world‐wide that also include a deep PSB community containing dense layers of ‘C. aggregatum’. Correlation analyses indicate that PSB community positioning and density are related to light, sulphide supply, redox potentials and pH. A 2‐factor principal components analysis (PCA) and other data trends supported these interpretations and indicated that PSB are sensitive to the thermal stability of the water column, are nitrogen limited and regulated more by sulphide or sulphide to light ratios than local levels of light. The sensitivity of these deep photosynthetic bacteria to environmental gradients, and their significance to some aquatic systems, demonstrate their potential as indicators of environmental disturbance.
Dissolved organic matter in small streams along a gradient from discontinuous to continuous permafrost
Authors: Kawahigashi Masayuki , Kaiser Klaus , Kalbitz Karsten , Rodionov Andrej , Guggenberger Georg
Published: September 2004

The Yenisei river passes every type of permafrost regime, from south to north, being characterized by increasing continuity of the permafrost and by decreasing thickness of the active layer. We used that situation to test the hypothesis that amounts and properties of dissolved organic matter (DOM) in small streams draining forested catchments respond to different permafrost regimes. Water samples were taken from eight tributaries along the Yenisei between 67°30′N and 65°49′N latitude. The samples were analysed for dissolved organic carbon (DOC) and nitrogen (DON) and DOM was characterized by its chemical composition (XAD‐8 fractionation, sugars, lignin phenols, amino acids, protein, UV and fluorescence spectroscopy), and its biodegradability. Most properties of the tributary waters varied depending on latitude. The higher the latitude, the higher were DOC, DON and the proportion of the hydrophobic fraction of DOC. The contribution of hexoses and pentoses to DOC were higher in southern tributaries; on the other hand, phenolic compounds were more abundant in northern tributaries. Mineralizable DOC ranged between 4% and 28% of total DOC. DOM in northern tributaries was significantly (P<0.05) less biodegradable than that in southern tributaries reflecting the differences in the chemical properties of DOM. Our results suggest that the differences in DOM properties are mainly attributed to differences of permafrost regime, affecting depth of active layer, soil organic matter accumulation and vegetation. Soil organic matter and vegetation determine the amount and composition of DOM produced in the catchments while the depth of the active layer likely controls the quantity and quality of DOM exported to streams. Sorptive interactions of DOM with the soil mineral phase typically increase with depth. The results imply that a northern shift of discontinuous permafrost likely will change in the long term the input of DOM into the Yenisei and thus probably into the Kara Sea.
Dynamics of carbon stocks in soils and detritus across chronosequences of different forest types in the Pacific Northwest, USA
Authors: Sun Osbert J. , Campbell John , Law Beverly E. , Wolf Vernon
Published: September 2004

We investigated variation in carbon stock in soils and detritus (forest floor and woody debris) in chronosequences that represent the range of forest types in the US Pacific Northwest. Stands range in age from <13 to >600 years. Soil carbon, to a depth of 100 cm, was highest in coastal Sitka spruce/western hemlock forests (36±10 kg C m−2) and lowest in semiarid ponderosa pine forests (7±10 kg C m−2). Forests distributed across the Cascade Mountains had intermediate values between 10 and 25 kg C m−2. Soil carbon stocks were best described as a linear function of net primary productivity (r2=0.52), annual precipitation (r2=0.51), and a power function of forest floor mean residence time (r2=0.67). The highest rates of soil and detritus carbon turnover were recorded on mesic sites of Douglas‐fir/western hemlock forests in the Cascade Mountains with lower rates in wetter and drier habitats, similar to the pattern of site productivity. The relative contribution of soil and detritus carbon to total ecosystem carbon decreased as a negative exponential function of stand age to a value of ∼35% between 150 and 200 years across the forest types. These age‐dependent trends in the portioning of carbon between biomass and necromass were not different among forest types. Model estimates of soil carbon storage based on decomposition of legacy carbon and carbon accumulation following stand‐replacing disturbance showed that soil carbon storage reached an asymptote between 150 and 200 years, which has significant implications to modeling carbon dynamics of the temperate coniferous forests following a stand‐replacing disturbance.
Neighbour identity modifies effects of elevated temperature on plant performance in the High Arctic
Authors: Dormann Carsten F. , Van Der Wal René , Woodin Sarah J.
Published: September 2004

Competition among plants in extreme environments such as the High Arctic has often been described as unimportant, or even nonexistent; environmental factors are thought to overrule any negative plant–plant interactions. However, few studies have actually addressed this question experimentally in the Arctic, and those that did found only little evidence for competition. Such species interactions will presumably become more important in the future, as Global Climate Change takes effect on terrestrial ecosystems. We investigated plant–plant interactions in the High Arctic, following the growth of Luzula confusa and Salix polaris in pure and mixed stands, and under elevated‐temperature treatment over 2 years. To understand the mechanisms of competition, a parallel experiment was undertaken in phytotrons, manipulating competition, temperature and nutrient availability. Our findings indicate that competition is acting in the natural vegetation, and that climatic warming will alter the balance of interactions in favour of the dwarf shrub S. polaris. The phytotron experiment suggested that the mechanism is a higher responsiveness of Salix to nutrient availability, which increased under warming in the field. While Luzula showed a positive response to higher temperature in the lab, its performance in mixed stands in the field was actually reduced by warming, indicating a competitive repression of growth by Salix. The growth of Salix was also reduced by the presence of Luzula, but it was still able to profit from warming. Our findings suggest that climatic warming will result in greater shrub dominance of High Arctic tundra, but we also conjecture that grazing could reverse the situation to a graminoid‐dominated tundra. These two divergent scenarios would have different implications for ecosystem feedbacks to climatic change.
Estimates of CO2 uptake and release among European forests based on eddy covariance data
Authors: Van Dijk Albert I. J. M. , (HAN) Dolman A. J.
Published: September 2004

The net ecosystem exchange (NEE) of forests represents the balance of gross primary productivity (GPP) and respiration (R). Methods to estimate these two components from eddy covariance flux measurements are usually based on a functional relationship between respiration and temperature that is calibrated for night‐time (respiration) fluxes and subsequently extrapolated using daytime temperature measurements. However, respiration fluxes originate from different parts of the ecosystem, each of which experiences its own course of temperature. Moreover, if the temperature–respiration function is fitted to combined data from different stages of biological development or seasons, a spurious temperature effect may be included that will lead to overestimation of the direct effect of temperature and therefore to overestimates of daytime respiration. We used the EUROFLUX eddy covariance data set for 15 European forests and pooled data per site, month and for conditions of low and sufficient soil moisture, respectively. We found that using air temperature (measured above the canopy) rather than soil temperature (measured 5 cm below the surface) yielded the most reliable and consistent exponential (Q10) temperature–respiration relationship. A fundamental difference in air temperature‐based Q10 values for different sites, times of year or soil moisture conditions could not be established; all were in the range 1.6–2.5. However, base respiration (R0, i.e. respiration rate scaled to 0°C) did vary significantly among sites and over the course of the year, with increased base respiration rates during the growing season. We used the overall mean Q10 of 2.0 to estimate annual GPP and R. Testing suggested that the uncertainty in total GPP and R associated with the method of separation was generally well within 15%. For the sites investigated, we found a positive relationship between GPP and R, indicating that there is a latitudinal trend in NEE because the absolute decrease in GPP towards the pole is greater than in R.
Carbon sequestration following afforestation of agricultural soils: comparing oak/beech forest to short‐rotation poplar coppice combining a process and a carbon accounting model
Authors: Deckmyn G. , Muys B. , Garcia Quijano J. , Ceulemans R.
Published: September 2004

To compare the benefits for carbon (C) sequestration of afforestation with a multifunctional oak–beech forest vs. a poplar short‐rotation coppice (SRC), model simulations were run through a serial linkage of a mechanistic model and an accounting model. The process model SECRETS (Stand to Ecosystem CaRbon and EvapoTranspiration Simulator) was used to predict growth, C allocation and soil C. The output from SECRETS was used as an input for the C accounting model GORCAM (Graz Oak Ridge Carbon Accounting Model) yielding data on C sequestration in wood products, substitution of wood fuel for fossil fuel and total CO2 emission reduction. Such C accounting based on a process model enables a more realistic calculation of forest growth, litter decomposition and soil processes. Moreover, it allows simulating the influence of climate change on the C budget.

Net primary production of an oak–beech forest is low, a stable 2.5 t C ha−1 yr−1 after 150 years, compared to 6.2 t C ha−1 yr−1 for a SRC plantation. But while the yield from the SRC poplar is used as fuel and thus returns quickly to the atmosphere, the yield from the oak‐beech forest is used in long‐lasting wood products. The total C pool in the mixed forest (living biomass, wood products and soil) after 150 years amounts to 324 t C ha−1 compared to 162 in the poplar coppice. However, when account is taken of the energy substitution, coppice culture reduces emissions with 24.3–29.3 t CO2 ha−1 yr−1 while the mixed forest reduces only 6.2–7.1 t CO2 ha−1 yr−1.

These results demonstrate the added value of combining detailed process models with C‐accounting models to improve the predictive capacity of model simulations.
Carbon sequestration and ecosystem respiration for 4 years in a Scots pine forest
Authors: Zha Tianshan , Kellomäki Seppo , Wang Kai‐Yun , Rouvinen Ismo
Published: September 2004

The net exchange of CO2 (NEE) between a Scots pine (Pinus sylvestris L.) forest ecosystem in eastern Finland and the atmosphere was measured continuously by the eddy covariance (EC) technique over 4 years (1999–2002). The annual temperature coefficient (Q10) of ecosystem respiration (R) for these years, respectively, was 2.32, 2.66, 2.73 and 2.69. The light‐saturated rate of photosynthesis (Amax) was highest in July or August, with an annual average Amax of 10.9, 14.6, 15.3 and 17.1 μmol m−2 s−1 in the 4 years, respectively. There was obvious seasonality in NEE, R and gross primary production (GPP), exhibiting a similar pattern to photosynthetically active radiation (PAR) and air temperature. The integrated daily NEE ranged from 2.59 to −4.97 g C m−2 day−1 in 1999, from 2.70 to −4.72 in 2000, from 2.61 to −4.71 in 2001 and from 5.27 to −4.88 in 2002. The maximum net C uptake occurred in July, with the exception of 2000, when it was in June. The interannual variation in ecosystem C flux was pronounced. The length of the growing season, based on net C uptake, was 179, 170, 175 and 176 days in 1999–2002, respectively, and annual net C sequestration was 152, 101, 172 and 205 g C m−2 yr−1. It is estimated that ecosystem respiration contributed 615, 591, 752 and 879 g C m−2 yr−1 to the NEE in these years, leading to an annual GPP of −768, −692, −924 and −1084 g C m−2 yr−1. It is concluded that temperature and PAR were the main determinants of the ecosystem CO2 flux. Interannual variations in net C sequestration are predominantly controlled by average air temperature and integrated radiation in spring and summer. Four years of EC data indicate that boreal Scots pine forest ecosystem in eastern Finland acts as a relatively powerful carbon sink. Carbon sequestration may benefit from warmer climatic conditions.
Identification and characterization of macaque CD89 (immunoglobulin A Fc receptor)
Authors: Rogers Kenneth A. , Scinicariello Franco , Attanasio Roberta
Published: September 2004

The interaction of the immunoglobulin A (IgA) molecule with its specific cellular receptor is necessary to trigger a variety of effector functions able to clear IgA‐opsonized antigens. The human IgA‐specific Fc receptor, FcαRI or CD89, is expressed on cells of the myeloid lineage. Recently, CD89 homologues have been identified in rats and cattle. Because non‐human primates represent well established models for a variety of human diseases and for the testing of immunotherapeutic strategies, we cloned and sequenced cDNAs corresponding to the CD89 gene from rhesus (Macaca mulatta) and cynomolgus (Macaca fascicularis) macaques. Macaque sequences of full‐length CD89 consist of five exons of length identical to the corresponding human CD89 exons. The rhesus and cynomolgus macaque derived amino acid sequences are highly homologous to each other (99·3% identity) and exhibit 86·5% and 86·1% identity to the human counterpart, respectively. Transfection of HeLa cells with plasmids containing the cloned macaque cDNAs resulted in the expression of surface molecules recognized by an anti‐human CD89 antibody. Five splice variants were identified in rhesus macaques. Three of the five variants are similar to described human CD89 splice variants, whereas two variants have not been described in humans. Three splice variants were identified in cynomolgus macaques. Of the three variants, one is present also in humans and rhesus macaques, whereas the other two are shared with rhesus macaques but not humans. Similarly to the human CD89, macaque CD89 is expressed on myeloid cells from peripheral blood. The characterization of macaque CD89 represents an essential step in establishing a non‐human primate model for the testing of immunotherapeutic approaches based on the manipulation of the IgA/CD89 interaction.
Differential analysis of CD4+ Th memory clones with identical T‐cell receptor (TCR)‐αβ rearrangement (non‐transgenic), but distinct lymphokine phenotype, reveals diverse and novel gene expression
Authors: Graham Christine M. , Thomas D. Brian
Published: September 2004

This study describes a subtractive hybridization analysis to identify differences in gene expression between sibling Th memory clones, elicited by virus infection and expressing identical T‐cell receptor (TCR)‐αβ rearrangements but distinct lymphokine phenotype: clone Bpp9 secretes interleukin (IL)‐4, IL‐5 and IL‐10; clone Bpp19 secretes interferon (IFN)‐γ, low levels of IL‐4, and IL‐5 on TCR ligation. cDNA sequencing of difference products (DP) identified both novel and known regulatory (DNA: RNA‐binding) or signalling proteins (kinases: phosphatases). Of the 10 novel genes identified, three were putative membrane proteins, one a predicted nuclear protein containing a PEST sequence motif, one a predicted transporter fragment and one contained a zinc‐finger motif. One of the membrane proteins was found only in RNA from the activated IFN‐γ‐producing clone, i.e. not in other tissues. In addition, a high frequency of granzyme A, B, C and G transcripts (for clone Bpp9) or transcripts for CD94 and NKG2A (for clone Bpp19) were expressed differentially, together with transcripts that mapped to, so far, unassigned regions of the mouse genome that may be further novel genes. The transcriptional profiles presented here may therefore include candidate regulators of Th diversity and effector function.
Oligodeoxynucleotides lacking CpG dinucleotides mediate Toll‐like receptor 9 dependent T helper type 2 biased immune stimulation
Authors: Vollmer Jörg , Weeratna Risini D. , Jurk Marion , Samulowitz Ulrike , Mccluskie Michael J. , Payette Paul , Davis Heather L. , Schetter Christian , Krieg Arthur M.
Published: September 2004

Oligodeoxynucleotides (ODN) with unmethylated CpG dinucleotides mimic the immune stimulatory activity of bacterial DNA in vertebrates and are recognized by Toll‐like receptor 9 (TLR9). It is also possible to detect immune activation with certain phosphorothioate sequences that lack CpG motifs. These ODN are less potent than CpG ODN and the mechanism by which they stimulate mammalian leucocytes is not understood. We here provide several lines of evidence demonstrating that the effects induced by non‐CpG ODN are mediated by TLR9. First, non‐CpG ODN could not stimulate cytokine secretion from the splenocytes of TLR9‐deficient (TLR9–/–) mice. Second, immunization of TLR9+/+ but not TLR9–/– mice with non‐CpG ODN enhanced antigen‐specific antibody responses, although these were T helper type 2 (Th2)‐biased. Third, reactivity to non‐CpG ODN could be reconstituted by transfection of human TLR9 into non‐responsive cells. In addition, we define a new efficient immune stimulatory motif aside from the CpG dinucleotide that consists of a 5′‐TC dinucleotide in a thymidine‐rich background. Non‐CpG ODN containing this motif induced activation of human B cells, but lacked stimulation of Th1‐like cytokines and chemokines. Our study indicates that TLR9 can mediate either efficient Th1‐ or Th2‐dominated effects depending on whether it is stimulated by CpG or certain non‐CpG ODN.
Signal transduction by the lipopolysaccharide receptor, Toll‐like receptor‐4
Authors: Pålsson‐McDermott Eva M. , O'Neill Luke A. J.
Published: September 2004

An understanding of lipopolysaccharide (LPS) signal transduction is a key goal in the effort to provide a molecular basis for the lethal effect of LPS during septic shock and point the way to novel therapies. Rapid progress in this field during the last 6 years has resulted in the discovery of not only the receptor for LPS – Toll‐like receptor 4 (TLR4) – but also in a better appreciation of the complexity of the signalling pathways activated by LPS. Soon after the discovery of TLR4, the formation of a receptor complex in response to LPS, consisting of dimerized TLR4 and MD‐2, was described. Intracellular events following the formation of this receptor complex depend on different sets of adapters. An early response, which is dependent on MyD88 and MyD88‐like adapter (Mal), leads to the activation of nuclear factor‐κB (NF‐κB). A later response to LPS makes use of TIR‐domain‐containing adapter‐inducing interferon‐β (TRIF) and TRIF‐related adapter molecule (TRAM), and leads to the late activation of NF‐κB and IRF3, and to the induction of cytokines, chemokines, and other transcription factors. As LPS signal transduction is an area of intense research and rapid progress, this review is intended to sum up our present understanding of the events following LPS binding to TLR4, and we also attempt to create a model of the signalling pathways activated by LPS.
Mutation analysis of the BOULE gene in men with non‐obstructive azoospermia: identification of a novel polymorphic variant in the black population
Authors: Lepretre Anne Claire , Patrat Catherine , Jouannet Pierre , Bienvenu Thierry
Published: September 2004

The BOULE gene is a member of the ‘deleted in azoospermia’DAZ family. As in flies and worms, disruption of the BOULE homologues leads to meiotic defects during the first meiotic division, we screened the coding region of the BOULE gene from 40 infertile men with non‐obstructive azoospermia or severe oligoasthenoteratozoospermia by denaturing high‐pressure liquid chromatography and direct sequencing in order to make progress in elucidating the aetiology of male infertility. Two infertile patients were heterozygous for a novel G to C transversion in exon 2 resulting in a Q2E amino acid substitution. As these two infertile men were from African origin, screening of fertile African subjects identified this novel variant in two fertile male subjects suggesting that this novel Q2E substitution had non‐pathologic role. Taking into account the size of our sample, we conclude that BOULE coding sequence mutations are not an important factor in the aetiology of azoospermia.
Electron microscopic observations of human sperm whole‐mounts after extraction for nuclear matrix and intermediate filaments (NM‐IF)
Authors: Markova Maya Dyankova
Published: September 2004

The extraction for nuclear matrix and intermediate filaments (NM–IF) is used to reveal, isolate and study these highly resistant structures in different cell types. We applied for the first time this chemical dissection to human spermatozoa and observed them as whole‐mounts by unembedded electron microscopy. The general appearance of NM–IF extracted sperm cells was preserved, showing the intermediate filament‐like properties of their cytoskeletal components. In most heads, a network was observed in subacrosomal position, consisting of hubs interconnected by filaments. It seemed to be overlaid on another, finer network. The neck retained its integrity, allowing observations of the three‐dimensional structure of the segmented columns. More distally, axoneme and outer dense fibres were covered by submitochondrial cytoskeleton in the middle piece and fibrous sheath in the principal piece, with the annulus usually detached from the fibrous sheath. End piece microtubules were retained in most cells and showed a tendency of cohesion, remaining in a parallel bundle or forming flat sheets. In conclusion, our results provided additional structural details of human sperm cytoskeleton and demonstrated the advantages of combining different methodological approaches in ultrastructural research.
Insulin‐like 3 signalling in testicular descent
Authors: Adham Ibrahim M. , Agoulnik Alexander I.
Published: September 2004

Undescended testis is one of the most common congenital defects in the newborn boys and the common cause of cryptorchidism. If left untreated, this condition is strongly associated with infertility and drastically increased risk of testicular cancer in adulthood. Testis position in developing males is defined by sexual dimorphic differentiation of two gonadal ligaments, gubernaculum and cranial suspensory ligament. Recent transgenic mouse studies identified testicular hormone insulin‐like 3 (INSL3), and its receptor, GREAT/LGR8, as the critical regulators of the gubernacular differentiation. Mutation analysis of the two genes in patients with undescended testis revealed functionally deleterious mutations, which may be responsible for the abnormal phenotype in some of the patients.
Partial purification and characterization of a trypsin‐like serine protease from bovine sperm
Authors: Cesari Andreina , Cacciato Claudio Santiago , De Castro Rosana Esther , Sánchez Jorge Julián
Published: September 2004

Sperm proteolytic activities are relevant in the enzymatic mechanism of fertilization. Several authors have suggested the presence of serine proteases other than acrosin in mice and human spermatozoa. In this work we describe the characterization of a partially purified bovine sperm serine protease BSp66 and its dimmer, BSp120. Partial purification of the monomer was performed from fresh spermatozoa, while the dimer form of the protease was obtained from cryopreserved spermatozoa. The Mr of BSp120 and BSp66 estimated by zymography and gel filtration chromatography were 120 and 66 kDa, respectively. They were positively stained by Schiff‐PAS reagent for glycoproteins and they both digested synthetic peptides with basic amino acids in the P1 site. Polyclonal antibodies against acrosin or proacrosin did not cross‐react neither with BSp120, nor BSp66. In addition, antibodies raised in our laboratory against BSp120 and BSp66 did not recognize acrosin or proacrosin suggesting that they are not antigenically related proteins. Also, no cross‐ reactivity was detected with proteins in the range of 120–66 kDa when antibodies against the proteasome were used. The cellular localization of this protease by optical immunocytochemistry using specific antibodies revealed a positive signal in the apical portion of the sperm head suggesting acrosomal or membrane localization. The evidences presented here characterize BSp66 as a trypsin‐like serine protease, a putative new member of this highly redundant proteolytic system of the sperm acrosome.
CFTR mutations and polymorphisms in male infertility
Authors: Cuppens Harry , Cassiman Jean‐Jacques
Published: September 2004

Apart from cystic fibrosis, mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are also involved in congenital bilateral absence of the vas deferens (CBAVD). A mutation is identified in about 80% of the CFTR genes derived from CBAVD patients; the genetic defect in the remainder is yet unknown. In contrast to CF patients, when CFTR is involved, at least one of the mutant CFTR genes of CBAVD patients harbors a mild mutation. A polyvariant mutant CFTR gene is the most frequent CBAVD causing mutant CFTR gene. Here, combinations of particular alleles at several polymorphic loci yield insufficient functional CFTR. The fact that most CBAVD patients, that carry mutations on both CFTR genes, have no lung disease is most probably explained by tissue specific alternative splicing, which is increased in vas deferens compared to bronchial tissue. It has also been reported that CBAVD may be involved in other forms of infertility than CBAVD, however this has not always been confirmed in other studies. Because of techniques such as intracytoplasmic sperm injection, CBAVD patients are now able to father children, however such couples have an increased risk of having a child with cystic fibrosis, and therefore genetic testing and counselling should be provided.
Estradiol levels in prepubertal boys and girls – analytical challenges
Authors: Bay Katrine , Andersson Anna‐Maria , Skakkebaek Niels E.
Published: September 2004

Increasing evidence points at an important function of low concentrations of estradiol (E2) in prepubertal boys and girls. E2 serum levels in prepubertal children are, however, often immeasurable in conventional E2 assays. This strongly hampers further investigation of the physiological relevance of E2 in children. In addition, there is an increasing concern of the potential effect of exposure to endocrine disrupters with estrogenic or antiandrogenic activity on pubertal development. A requirement of assessing the instance for this concern, adds further to the demands for applicable methodologies for the evaluation of the sensitivity of the organism to low E2 concentrations. Traditionally, E2 is measured by use of the radioimmunoassay (RIA). As an ultrasensitive alternative to the RIA, a recombinant cell bioassay has been developed. In this review, methodological aspects for these methods of analysis are examined and their applicability for evaluation of low E2 serum concentrations in children is estimated. Furthermore, available data on E2 levels in prepubertal boys and girls are evaluated and discussed, taking into consideration the limitations of the methods of analysis. In conclusion, there is a pronounced demand for new and improved methods of analysis for accurate and sensitive evaluation of low concentrations of E2.
Systematic relaxation to relieve postoperative pain
Authors: Roykulcharoen Varunyupa , Good Marion
Published: September 2004

Background.  Unrelieved pain after surgery can lead to complications, prolonged hospital stay, and delayed recovery. Because of side effects from opioids and differences in response, it is important to use non‐pharmacological methods in addition to analgesics to decrease patient discomfort and anxiety.

Aims.  We examined the effects of a systematic method of relaxing the body on the sensory and affective components of postoperative pain, anxiety, and opioid intake after initial ambulation.

Design.  A randomized controlled trial with relaxation and control groups was used.

Method.  The convenience sample of 102 adults underwent abdominal surgery at a large hospital in Thailand. Systematic relaxation was used for 15 minutes during recovery from the first ambulation after surgery. Pain was measured with 100 mm Visual Analogue Sensation and Distress of Pain Scales before and after the intervention. State anxiety was measured before surgery and after the intervention; opioid intake was recorded 6 hours later.

Results.  The relaxation group had less post‐test sensation and distress of pain (26 and 25 mm less, respectively) than the control group (P = 0·001). Relaxation did not result in significantly less anxiety or 6‐hour opioid intake. However, group differences in state anxiety were in the expected direction and fewer participants in the relaxation group requested opioids. Nearly all reported that systematic relaxation reduced their pain and increased their sense of control.

Conclusion.  Substantial reductions in the sensation and distress of pain were found when postoperative patients used systematic relaxation. Although tested in Thailand, we recommend that nurses in other countries try systematic relaxation with postoperative patients, in addition to analgesic medication, measuring pain scores and asking about cultural acceptance.
Effect of metal strengthener length on stress distribution in acrylic denture bases: a finite element study
Authors: Shimizu H. , Ikeda T. , Wakabayashi N. , Ohyama T.
Published: September 2004

summary  This study investigated the influence of metal strengthener length on stress created in acrylic denture bases in relation to location of the vertical support to the dentures. Finite element analysis was conducted to calculate stress generated in the straps of 2 mm‐thickness and 18 mm‐width that were reinforced with metal strengtheners of five different lengths. A vertical biting force of 60 N was directed on one end of each strap, while the other end was fixed. Vertical movements were restricted at one of the three support locations between the centre of the strap and the loading site. When the straps were vertically supported near the loading site, greater maximum tensile stresses were seen in the straps with relatively short strengtheners than those shown in the straps with longer strengtheners. The metal strengtheners with sufficient length may provide a preventive denture design against the acrylic fractures.
Relationship between dental care and oral health in institutionalized elderly people in Japan
Authors: Shimazaki Y. , Soh I. , Koga T. , Miyazaki H. , Takehara T.
Published: September 2004

summary  This study examined the relationship between dental care and dental health status in institutionalized elderly people in Japan through a 6‐year prospective cohort study. All the 719 subjects received both baseline and follow‐up surveys. The uptake of dental care was examined at the follow‐up survey. We examined the relationship between baseline variables and the provision of dental care, and the relationship between dental care and change of oral health status. About 47% of the subjects and about 60% of the baseline dentate subjects received some dental treatment during the 6‐year follow‐up period. The subjects who were in better systemic and dental health at baseline used dental services frequently. The number of teeth needing extraction decreased in the subjects who received dental treatment, and increased in the untreated subjects. Denture status was better in the treated subjects than in the untreated subjects. Dental care appears to be an important factor in maintaining a healthy oral status for the institutionalized elderly.
Contribution of indole alkaloids to Sitobion avenae (F.) resistance in wheat
Authors: Cai Q. N. , Zhang Q. W. , Cheo M.
Published: September 2004

Abstract:  Indole alkaloid contents of five winter wheat varieties at different growth stages, and the relationship between indole alkaloids and carboxylesterase activities of Sitobion avenae (F.) from wheat ears of different varieties were studied. The results indicated that KOK1679 and My295, highly and moderately aphid‐resistant varieties, had a high indole alkaloid content during vegetative growth. During their reproduction growth, resistant varieties had a high alkaloid content in penultimate leaves, and indole alkaloid contents of KOK1679 were significantly higher than that of other varieties in wheat ears. The indole alkaloid contents of all varieties were low in flag leaves except for Han4564. A significant correlation was shown between carboxylesterase activity in aphids collected from wheat ears and indole alkaloid contents in ears of the wheat varieties (r = 0.9646).
Ecological, Reproductive and Ontogenetic Features in Pajaudina atlantica Logan (Thecideidae, Brachiopoda, Recent) from the Canary Islands
Authors: Logan Alan
Published: September 2004

Abstract.  The lacazelline brachiopod Pajaudina, with type species P. atlantica, was originally described by the author in 1988 from dead and transported shells collected by Dutch CANCAP expeditions to the Canary Islands. Living sites have now been discovered in shallow‐water caves on El Hierro and La Palma in the Canary Islands. From photographs and specimens, information has been obtained on life habits and associated biota, the nature of the ptycholophe lophophore, sexually dimorphic characters of the shell and ontogenetic growth stages of the dorsal valve. The latter are shown to be similar to those of Lacazella, as exemplified by L. caribbeanensis from the Bahamas, up to the penultimate stage, following which there are repeated furcations of the minor interbrachial lobes not seen in Lacazella but present in Ospreyella Lüter & Wörheide.
Do Harpacticoids (Copepoda) Use Water‐Borne Cues to Aid in Locating Food Parcels?
Authors: Fechter Andrea , Thistle David , Arlt Günter , Suderman Keith , Vopel Kay
Published: September 2004

Abstract.  Harpacticoid copepod food is patchily distributed and individuals must episodically move to new food patches. Key questions in harpacticoid feeding ecology include how individuals detect food patches and how rapidly they move toward patches. Based on literature reports, we hypothesized that harpacticoids locate food parcels by sensing a water‐borne cue. We tested this idea using individuals of Leptastacus coulli Huys, 1992 and Praeleptomesochra similis Lang, 1965 from a sandy beach in north Florida (29.948° N, 84.341° W). Individuals from both species selected seawater that had been exposed to food significantly more frequently than they selected control seawater. The rate of movement of these species was millimeters per second, which agreed with previous reports.