bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of the Moisture Capacity of Porous Building Materials
Authors: Carmeliet Jan , Roels Staf
Published: April 2009

The moisture capacity, which is required to solve the isothermal moisture transport equation, is generally expressed by parametric functions covering both the hygroscopic and over-hygroscopic regime. The modality or number of analytical functions needed to describe the corresponding pore volume distribution is introduced as an important parameter for a proper description of the moisture capacity or capillary pressure curve. We used the Markov procedure to estimate the parameters. The method allows not only to evaluate the goodness of fit and the wellposedness of the parameter identification problem, but also to determine the optimal location of the experimental data in order to minimize the effect of errors on the estimated parameters. We found that the wetting capillary pressure curve, relevant for many building physics problems of hygroscopic capillary active materials, is preferentially described by bimodal functions or unimodal functions withsufficient flexibility towards the hygroscopic zone. The use of fixed values of relative humidity for determining the limit between hygroscopic and over-hygroscopic regime cannot be recommended as useful a priori information. This limiting moisture content is rather a fitting parameter and is found not to coincide with the knick point moisture content defining the transition from vapor to liquid permeability. The optimal location of the experimental data is highly dependent on the chosen functional model and on the considered material. The goodness of fit only slightly reduces when using a minimal number of optimal data points compared to an extended data set.
Turnover in flightless invertebrate species composition over different spatial scales in Afrotemperate forest in the Drakensberg, South Africa
Authors: Uys Charmaine , Hamer Michelle , Slotow Rob
Published: April 2009

An understanding of species turnover at different spatial scales and the influence of environmental variables including distance are important for conservation planning and management. Ground dwelling, flightless invertebrates have poor dispersal abilities and other taxa may not be effective as surrogates. This is an important consideration for biodiversity conservation in Afrotemperate forests of the Drakensberg Mountains, South Africa, where flightless invertebrates are geographically isolated by the naturally fragmented state of forests. Seventeen Afrotemperate forests in four reserves across the Drakensberg were sampled using soil and leaf litter sampling, pitfall traps, active search quadrats and tree beats. Seventy‐two species were recorded, comprising 31 mollusc, nine earthworm, one onychophoran, six centipede, twelve millipede and thirteen ant species. Canonical correspondence analysis indicated that latitude (distance); fire history (disturbance) and mean annual precipitation were the most important factors governing invertebrate assemblage composition. βsim measurements detected change in species at all spatial scales investigated, but no clear trends were evident. Distance or spatial scale alone does not explain species turnover and community composition. Effective selection of target areas, therefore, requires species level information to identify species of special concern.
In vitro three‐dimensional modelling of human ovarian surface epithelial cells
Authors: Lawrenson K. , Benjamin E. , Turmaine M. , Jacobs I. , Gayther S. , Dafou D.
Published: April 2009

Objectives:  Ninety percent of malignant ovarian cancers are epithelial and thought to arise from the ovarian surface epithelium (OSE). We hypothesized that biological characteristics of primary OSE cells would more closely resemble OSE in vivo if established as three‐dimensional (3D) cultures.

Materials and methods:  OSE cells were cultured as multicellular spheroids (MCS) (i) in a rotary cell culture system (RCCS) and (ii) on polyHEMA‐coated plastics. The MCSs were examined by electron microscopy and compared to OSE from primary tissues and cells grown in 2D. Annexin V FACS analysis was used to evaluate apoptosis and expression of extracellular matrix (ECM) proteins was analysed by immunohistochemical staining.

Results:  On polyHEMA‐coated plates, OSE spheroids had defined internal architecture. RCCS MCSs had disorganized structure and higher proportion of apoptotic cells than polyHEMA MCSs and the same cells grown in 2D culture. In 2D, widespread expression of AE1/AE3, laminin and vimentin were undetectable by immunohistochemistry, whereas strong expression of these proteins was observed in the same cells grown in 3D culture and in OSE on primary tissues.

Conclusions:  Physiological and biological features of OSE cells grown in 3D culture more closely resemble characteristics of OSE cells in vivo than when grown by classical 2D approaches. It is likely that establishing in vitro 3D OSE models will lead to greater understanding of the mechanisms of neoplastic transformation in epithelial ovarian cancers.
Arsenic trioxide suppresses paclitaxel‐induced mitotic arrest
Authors: Duan Q. , Komissarova E. , Dai W.
Published: April 2009

Objectives:  To understand if there exists a functional interaction between arsenic trioxide and paclitaxel in vitro.

Materials and methods:  HeLa and HCT116 (ρ53+/+ and ρ53−/−) cells were treated with As2O3 and/or paclitaxel for various times. Treated cells were collected for analyses using a combination of flow cytometry, fluorescence microscopy and Western blotting.

Results:  Because As2O3 is capable of inhibiting tubulin polymerization and inducing mitotic arrest, we examined whether there existed any functional interaction between As2O3 and paclitaxel, a well‐known microtubule poison. Flow cytometry and fluorescence microscopy revealed that although As2O3 alone caused a moderate level of mitotic arrest, it greatly attenuated paclitaxel‐induced mitotic arrest in cells with p53 deficiency. Western blot analysis showed that As2O3 significantly blocked phosphorylation of BubR1, Cdc20, and Cdc27 in cells treated with paclitaxel, suggesting that arsenic compromised the activation of the spindle checkpoint. Our further studies revealed that the attenuation of paclitaxel‐induced mitotic arrest by As2O3 resulted primarily from sluggish cell cycle progression at S phase but not enhanced mitotic exit.

Conclusion:  The observations that As2O3 has a negative impact on the cell cycle checkpoint activation by taxol should have significant clinical implications because the efficacy of taxol in the clinics is associated with its ability to induce mitotic arrest and subsequent mitotic catastrophe.
Thalidomide has a therapeutic effect on interstitial lung fibrosis: evidence from in vitro and in vivo studies
Authors: Zhao L , Xiao K , Wang H , Wang Z , Sun L , Zhang F , Zhang X , Tang F , He W
Published: April 2009

The objective of this study was to investigate the effects of thalidomide (THD) on interstitial lung fibrosis (ILF). In vitro, human fetal lung fibroblast (HFL-F) to myofibroblast (MF) trans-differentiation was induced by transforming growth factor (TGF)-β1. The effects of THD on trans-differentiation process or differentiated MF were evaluated by measuring hydroxyproline (HYP) content by alkaline hydrolysis colorimetry, α-smooth muscle actin (α-SMA) protein by Western blot and α-SMA and pro-collagen III mRNA expressions by semi-quantitative reverse transcription–polymerase chain reaction; in vivo, a mouse model of ILF was generated by daily subcutaneous injection of bleomycin (BLM) in female C3H mice. Gastric perfusion of THD began 1 week prior to injection and lasted for 8 weeks. Lung specimens were harvested at different time-points (1, 4, 6 and 8 weeks) for pathology and immunohistochemistry examination. The HYP content, α-SMA and pro-collagen III mRNA expressions were also assessed. THD inhibited the up-regulation of HYP protein, pro-collagen III mRNA and α-SMA protein induced by TGF-β1 in HFL-F cells, and additionally inhibited pro-collagen III mRNA expression on trans-differentiated MF. THD reduced HYP synthesis in the lung tissues of BLM-treated mice at week 4, and slightly reduced the numbers of α-SMA-positive cells. THD had an effect on ILF models both in vitro and in vivo.
Mesangial medium with IgA1 from IgA nephropathy inhibits nephrin expression in mouse podocytes
Authors: Wang C. , Liu X. , Ye Z. , Zhang J. , Tang H. , Chen Z. , Zhang H. , Lou T.
Published: April 2009

Background  IgA nephropathy (IgAN) is characterized by mesangial deposition of polymeric IgA1, and podocyte injury plays an important role in glomerulosclerosis of the disease. Our previous study indicated that medium of mesangial cells co‐incubated with aggregated IgA1 (aIgA1), isolated from IgAN patients, down‐regulated nephrin expression. Yet the mechanism remains unclear.

Materials and methods  Podocytes were incubated with a medium of mesangial cells co‐incubated with aIgA1, which was isolated from IgAN patients, and enalaprilat (10−5 M), valsartan (10−5 M) and anti‐mouse tumour necrosis factor‐α antibody (50 ng mL−1) separately. Nephrin expression in podocytes was measured by real‐time polymerase chain reaction and Western blot analysis.

Results  The level of angiotensinogen and angiotensin‐converting enzyme mRNAs in podocytes, as well as angiotensin, was also increased by a medium of mesangial cells co‐incubated with aIgA1 from IgAN patients(P < 0·05). Enalaprilat or valsartan partly improved nephrin expression when compared with that by podocytes exposed to the mesangial medium (P < 0·05), while the nephrin expression of podocytes with enalaprilat or valsartan was lower than that of podocytes exposed to medium of mesangial cells stimulated by aIgA1 from healthy control (P < 0·05). However, anti‐mouse tumour necrosis factor‐α antibody did not show any improvement in nephrin expression.

Conclusion  Our findings implicate that local renin angiotensin system activation in podocytes is partly involved in down‐regulation of nephrin by mesangial medium in IgA nephropathy.
Climate change‐predicted shifts in the temperature regime of shallow groundwater produce rapid responses in ciliate communities
Authors: ANDRUSHCHYSHYN OKSANA P. , WILSON KEVIN P. , WILLIAMS D. DUDLEY
Published: April 2009

The ciliates living in a shallow groundwater system in southern Ontario, Canada were subjected to anin situtemperature manipulation over 14 months. Ciliates were collected from the bed surface of a small springbrook and from interstitial water collected at five depths beneath its surface. Mean temperature elevations established at each depth (−20, −40, −60, −80, and −100 cm) between the experiment's control and treatment blocks were 1.9, 3.5, 3.9, 3.8, and 3.6 °C, respectively, and were based on global warming projections for the region. In total, 160 species of ciliate belonging to 85 genera were identified. Overall, the treatment block had a higher density (6510±342 cells L−1; ±1 SE) than the control (5797±237 cells L−1), but densities were both vertically and longitudinally variable. Control densities decreased with depth, whereas treatment densities were more equal among depths. Total species richness showed no significant difference between blocks when combining all sampling dates and depths, although species composition changed. The ciliate community was dominated by small (15–50 μm), followed by medium (50–200 μm), and only a few large‐sized (>200 μm) species. Small ciliates contributed 82–97% of the total density. Small ciliates also contributed more to the treatment (94%) than the control block (88%). The most common ciliate feeding groups were bacterivores, omnivores, predators, and algae‐diatom feeders, with bacterivores being most dominant (83–99% of the total numbers collected). Ordination analyses revealed that ciliate distribution was strongly correlated with groundwater temperature, although dissolved oxygen level, concentrations of ammonia and nitrate, and depth also appeared to be influential. Peak densities of many species occurred in either the control or treatment blocks, but not in both. The benefits of using ciliates as a proxy for higher, much longer‐lived, eukaryotes in climate change studies are discussed.
Rainfall distribution is the main driver of runoff under future CO2‐concentration in a temperate deciduous forest
Authors: LEUZINGER SEBASTIAN , KÖRNER CHRISTIAN
Published: April 2009

Reduced stomatal conductance under elevated CO2 results in increased soil moisture, provided all other factors remain constant. Whether this results in increased runoff critically depends on the interaction of rainfall patterns, soil water storage capacity and plant responses. To test the sensitivity of runoff to these parameters under elevated CO2, we combine transpiration and soil moisture data from the Swiss Canopy Crane FACE experiment (SCC, 14 30–35 m tall deciduous broad‐leaved trees under elevated CO2) with 104 years of daily precipitation data from an adjacent weather station to drive a three‐layer bucket model (mean yearly precipitation 794 mm). The model adequately predicts the water budget of a temperate deciduous forest and runoff from a nearby gauging station. A simulation run over all 104 years based on measured sap flow responses resulted in only 5.5 mm (2.9%) increased ecosystem runoff under elevated CO2. Out of the 37 986 days (1 January 1901–31 December 2004), only 576 days produce higher runoff in the elevated CO2 scenario. Only 1 out of 17 years produces a CO2‐signal >20 mm a−1, which mostly depends on a few single days when runoff under elevated CO2 exceeds runoff under ambient conditions. The maximum signal for a double preindustrial CO2‐concentration under the past century daily rainfall regime is an additional runoff of 46 mm. More than half of all years produce a signal of <5 mm a−1, because trees consume the ‘extra’ moisture during prolonged dry weather. Increased runoff under elevated CO2 is nine times more sensitive to variations in rain pattern than to the applied reduction in transpiration under elevated CO2. Thus the key driver of increased runoff under future CO2‐concentration is the day by day rainfall pattern. We argue that increased runoff due to a first‐order plant physiological CO2‐effect will be very small (<3%) in a landscape dominated by temperate deciduous forests, and will hardly increase flooding risk in forest catchments. Monthly rainfall sums are unsuitable to realistically model such CO2 effects. These findings may apply to other ecosystems with comparable soil water storage capacity.
Promoted activation of matrix metalloproteinase (MMP)‐2 in keloid fibroblasts and increased expression of MMP‐2 in collagen bundle regions: implications for mechanisms of keloid progression
Authors: Imaizumi Risa , Akasaka Yoshikiyo , Inomata Naomi , Okada Emi , Ito Kinji , Ishikawa Yukio , Maruyama Yu
Published: April 2009

Aims:  Keloid is characterized by excessive deposition of collagen, resulting from aberrant extracellular matrix (ECM) production and degradation. The aim was to investigate the role of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in pathological wound healing in keloids.

Methods and results:  Semiquantitative analysis of 60 keloid tissue samples and 25 mature scar tissue samples demonstrated significantly increased expression of MMP‐2, TIMP‐2 and TIMP‐3 in keloids compared with mature scars. Within keloid regions, MMP‐2 expression was significantly higher in collagen bundle regions than in non‐collagen bundle regions. Double immunofluorescence revealed that keloid fibroblasts between collagen bundles exhibited MMP‐2, TIMP‐2 and membrane‐type 1 MMP (MT1‐MMP) co‐expression, whereas only MMP‐2 expression was evident on the edge of collagen bundles. Western blot analysis and gelatin zymography of 13 keloid‐derived fibroblasts (KFbs) and six normal skin dermal‐derived fibroblasts (NFbs) demonstrated that unstimulated KFbs exhibited significantly increased MMP‐2 activity and expression compared with NFbs under the same conditions.

Conclusions:  These results together indicate that MMP‐2 activity can be promoted in keloid fibroblasts between collagen bundles in cooperation with TIMP‐2 and MT1‐MMP. This could contribute to remodelling of collagen bundle regions and invasion of fibroblasts into peripheral normal regions through promoted degradation of ECM.
UbcH10 expression in human lymphomas
Authors: Troncone Giancarlo , Guerriero Eliana , Pallante Pierloronzo , Berlingieri Maria Teresa , Ferraro Angelo , Del Vecchio Luigi , Gorrese Marisa , Mariotti Elisabetta , Iaccarino Antonino , Palmieri Emiliano A , Zeppa Pio , Palombini Lucio , Fusco Alfredo
Published: April 2009

Aims:  The UbcH10 ubiquitin‐conjugating enzyme plays a key role in regulating mitosis completion. We have previously reported that UbcH10 overexpression is associated with aggressive thyroid, ovarian and breast carcinomas. The aim of this study was to investigate UbcH10 expression in human lymphomas.

Methods and results:  Cell lines and tissue samples of Hodgkin’s lymphoma (HL) and of non‐Hodgkin’s lymphoma (NHL) were screened for UbcH10 expression at transcriptional and translational levels. UbcH10 expression was related to the grade of malignancy. In fact, it was low in indolent tumours and high in a variety of HL and NHL cell lines and in aggressive lymphomas. It was highest in Burkitt’s lymphoma, as shown by quantitative real‐time polymerase chain reaction and by tissue microarray immunohistochemistry. Flow cytometry of cell lines confirmed that UbcH10 expression is cell‐cycle dependent, steadily increasing in S phase, peaking in G2/M phase and dramatically decreasing in G0/G1 phases. We also showed that UbcH10 plays a relevant role in lymphoid cell proliferation, since blocking of its synthesis by RNA interference inhibited cell growth.

Conclusions:  Taken together, these results indicate that UbcH10 is a novel lymphoid proliferation marker encompassing the cell cycle window associated with exit from mitosis. Its overexpression in aggressive lymphomas suggests that UbcH10 could be a therapeutic target in this setting.
Elucidation of the regulation of an adult cuticle gene Acp65A by the transcription factor Broad
Authors: Cui H.‐Y. , Lestradet M. , Bruey‐Sedano N. , Charles J.‐P. , Riddiford L. M.
Published: April 2009

Broad (BR), an ecdysone‐inducible transcription factor, is a major determinant of the pupal stage. The misexpression of BR‐Z1 isoform (BR‐Z1) during adult development of Drosophila melanogaster prevents the expression of the adult cuticle protein 65A gene (Acp65A). We found that the proximal 237 bp of the 5′ flanking region of Acp65A were sufficient to mediate this suppression. A targeted point mutation of a putative BR‐Z1 response element (BRE) within this region showed that it was not involved. Drosophila hormone receptor‐like 38 (DHR38) is required for Acp65A expression. We found that BR‐Z1 repressed DHR38 expression and that BR's inhibition of Acp65A expression was rescued by exogenous expression of DHR38. Thus, BR‐Z1 suppresses Acp65A expression by preventing the normal up‐regulation of DHR38 at the time of adult cuticle formation.
Assessment of acridine orange and SYTO 16 for in vivo imaging of the peritoneal tissues in mice
Authors: UDOVICH J.A. , BESSELSEN D.G. , GMITRO A.F.
Published: April 2009

The effect of peritoneal injection of acridine orange and SYTO 16 in mice was investigated. Images of peritoneal tissues stained with these dyes and obtained through a confocal micro‐endoscope are presented. Seventy‐five Balb/c mice were split into five groups and given peritoneal injections of dye or saline. The proportions of negative outcomes in each group were compared using confidence intervals and the Fisher's exact statistical test. A statistically significant increase in adverse events due to dye injection was not observed. These data provide an initial investigation into the safety of acridine orange and SYTO 16 for in vivo imaging.
Disassembly of DNA–ligand on mica surface: atomic force microscopy studies
Authors: SONG Y. , WANG L. , ZHAO S. , LIAN W. , LI Z.
Published: April 2009

Disassembly of DNA–ligands, including DNA–methylene blue (MB) complex and DNA–Co(phen)33+ complex on mica surface, were investigated by atomic force microscopy (AFM). The disassembly of these complexes occurred after they were immersed in ultra‐pure water. AFM results showed that the disassembly depended strongly on bridge ions that were used to immobilize the complex onto mica surface, DNA species and ligands. When Mg2+ was used as the bridge ion, the DNA–MB complex was completely disassembled because of the weak interactions between Mg2+ and DNA's bases or mica surface. Although if Co2+ was used as the bridge ion, the disassembly of the DNA–MB complex mainly depended on the species and shape of DNA. For plasmid DNA pBR 322, plasmid DNA pUC 18 and the linear DNA pBR 322/PstI, the degree of disassembly was gradually increased. Whereas if Co(phen)33+ was chosen as the ligand, the disassembly of the DNA–Co(phen)33+ complex was almost blocked because Co(phen)33+ could hardly diffuse into the ultra‐pure water. This obtained information may be useful for practical application of the AFM imaging of biological molecules, especially in liquid.
Fast linear feature detection using multiple directional non‐maximum suppression
Authors: SUN C. , VALLOTTON P.
Published: April 2009

The capacity to detect linear features is central to image analysis, computer vision and pattern recognition and has practical applications in areas such as neurite outgrowth detection, retinal vessel extraction, skin hair removal, plant root analysis and road detection. Linear feature detection often represents the starting point for image segmentation and image interpretation. In this paper, we present a new algorithm for linear feature detection using multiple directional non‐maximum suppression with symmetry checking and gap linking. Given its low computational complexity, the algorithm is very fast. We show in several examples that it performs very well in terms of both sensitivity and continuity of detected linear features.
Two‐colour two‐photon confocal microscopy with isotropic three‐dimensional resolution and parallel excitation
Authors: NI J. , QIAO L. , WANG C. , ZHAO F. , CHENG Y. , XU Z.
Published: April 2009

We demonstrate a novel design of two‐colour two‐photon fluorescence microscope in which isotropic three‐dimensional imaging resolution and high scanning speed can be achieved simultaneously. In our scheme, a three‐dimensional optical lattice constructed by multi‐beam interference is used for two‐colour two‐photon fluorescence excitation. Our simulation results show that a resolution of 113.5 nm can be achieved in both transverse and axial directions with two pump pulses at the wavelengths of 400 and 800 nm, respectively; meanwhile, imaging speed can be greatly improved compared with that of traditional two‐photon scanning fluorescence microscopes.
Capsule‐supporting ring: a new device for resin embedding of glass‐mounted specimens
Authors: SAWAGUCHI A. , AOYAMA F. , IDE S. , SUGANUMA T.
Published: April 2009

The goal of specimen preparation for transmission electron microscopy is to obtain high‐quality ultra‐thin sections with which we can correlate cellular structure to physiological function. In this study, we newly developed a capsule‐supporting ring that can be useful for resin embedding of glass‐mounted specimens. The present device allowed us to re‐embed a semi‐thin section on a microscope slide into a resin block not only for efficient ultra‐thin sectioning but also for a correlative light and electron microscopy. Similar to epoxy resins for morphological observations, semi‐thin sections of low‐viscosity hydrophilic resins, such as Lowicryl series, can be re‐embedded into the resin, which can be useful for cytochemical gold labelling. A further application of the present device improved flat embedding of cultured cells on glass cover slips for electron microscopy, preserving in situ sub‐cellular structures close to their native state. We practically describe the use of capsule‐supporting ring and demonstrate representative micrographs as results.
High‐resolution manometry in clinical practice: utilizing pressure topography to classify oesophageal motility abnormalities
Authors: Pandolfino J. E. , Fox M. R. , Bredenoord A. J. , Kahrilas P. J.
Published: April 2009

Abstract  High‐resolution manometry capable of pressure monitoring from the pharynx to the stomach together with pressure topography plotting represents an unquestionable evolution in oesophageal manometry. However, with this advanced technology come challenges and one of those is devising the optimal scheme to apply high‐resolution oesophageal pressure topography (HROPT) to the clinical evaluation of patients. The first iteration of the Chicago classification was based on a systematic analysis of motility patterns in 75 control subjects and 400 consecutive patients. This review summarizes the analysis process as it has evolved. Individual swallows are analysed in a stepwise fashion for the morphology of the oesophagogastric junction (OGJ), the extent of OGJ relaxation, the propagation velocity of peristalsis, the vigour of the peristaltic contraction, and abnormalities of intrabolus pressure utilizing metrics that have now been customized to HROPT. These results are then synthesized into a comprehensive diagnosis that, although based on conventional manometry criteria, is also customized to HROPT measures. The resultant classification objectifies the identification of three unique subtypes of achalasia. Additionally, it provides enhanced detail in the description of distal oesophageal spasm, nutcracker oesophagus subtypes, and OGJ obstruction. It is our expectation that modification of this classification scheme will continue to occur and this should further clarify the utility of pressure topography plotting in assessing oesophageal motility disorders.
Effects of clonidine and sumatriptan on postprandial gastric volume response, antral contraction waves and emptying: an MRI study
Authors: Kwiatek M. A. , Fox M. R. , Steingoetter A. , Menne D. , Pal A. , Fruehauf H. , Kaufman E. , Forras‐kaufman Z. , Brasseur J. G. , Goetze O. , Hebbard G. S. , Boesiger P. , Thumshirn M. , Fried M. , Schwizer W.
Published: April 2009

Abstract  Gastric emptying (GE) may be driven by tonic contraction of the stomach (‘pressure pump’) or antral contraction waves (ACW) (‘peristaltic pump’). The mechanism underlying GE was studied by contrasting the effects of clonidine (α2‐adrenergic agonist) and sumatriptan (5‐HT1 agonist) on gastric function. Magnetic resonance imaging provided non‐invasive assessment of gastric volume responses, ACW and GE in nine healthy volunteers. Investigations were performed in the right decubitus position after ingestion of 500 mL of 10% glucose (200 kcal) under placebo [0.9% NaCl intravenous (IV) and subcutaneous (SC)], clonidine [0.01 mg min−1 IV, max 0.1 mg (placebo SC)] or sumatriptan [6 mg SC (placebo IV)]. Total gastric volume (TGV) and gastric content volume (GCV) were assessed every 5 min for 90 min, interspersed with dynamic scan sequences to measure ACW activity. During gastric filling, TGV increased with GCV indicating that meal volume dictates initial relaxation. Gastric contents volume continued to increase over the early postprandial period due to gastric secretion surpassing initial gastric emptying. Clonidine diminished this early increase in GCV, reduced gastric relaxation, decreased ACW frequency compared with placebo. Gastric emptying (GE) rate increased. Sumatriptan had no effect on initial GCV, but prolonged gastric relaxation and disrupted ACW activity. Gastric emptying was delayed. There was a negative correlation between gastric relaxation and GE rate (r2 = 49%, P < 0.001), whereas the association between ACW frequency and GE rate was inconsistent and weak (r2 = 15%, P = 0.05). These findings support the hypothesis that nutrient liquid emptying is primarily driven by the ‘pressure pump’ mechanism.
A cytosolic class I small heat shock protein, RcHSP17.8, of Rosa chinensis confers resistance to a variety of stresses to Escherichia coli, yeast and Arabidopsis thaliana
Authors: JIANG CHANGHUA , XU JIANYAO , ZHANG HAO , ZHANG XUAN , SHI JINLEI , LI MIN , MING FENG
Published: April 2009

Among the heat shock proteins (HSPs) of higher plants, those belonging to the small HSP (sHSP) family remain the least characterized in functional terms. To improve our understanding of sHSPs, we have characterized RcHSP17.8 from Rosa chinensis. Sequence alignments and phylogenetic analysis reveal this to be a cytosolic class I sHSP. RcHSP17.8 expression in R. chinensis was induced by heat, cold, salt, drought, osmotic and oxidative stresses. Recombinant RcHSP17.8 was overexpressed in Escherichia coli and yeast to study its possible function under stress conditions. The recombinant E. coli and yeast cells that accumulated RcHSP17.8 showed improved viability under thermal, salt and oxidative stress conditions compared with control cultures. We also produced transgenic Arabidopsis thaliana that constitutively expressed RcHSP17.8. These plants exhibited increased tolerance to heat, salt, osmotic and drought stresses. These results suggest that R. chinensis cytosolic class I sHSP (RcHSP17.8) has the ability to confer stress resistance not only to E. coli and yeast but also to plants grown under a wide variety of unfavorable environmental conditions.
Night‐time transpiration can decrease hydraulic redistribution
Authors: HOWARD AVA R. , VAN IERSEL MARC W. , RICHARDS JAMES H. , DONOVAN LISA A.
Published: April 2009

C3 plants dominate many landscapes and are critically important for ecosystem water cycling. At night, plant water losses can include transpiration (Enight) from the canopy and hydraulic redistribution (HR) from roots. We tested whether Enight limits the magnitude of HR in a greenhouse study using Artemisia tridentata, Helianthus anomalus and Quercus laevis. Plants were grown with their roots split between two compartments. HR was initiated by briefly withholding all water, followed by watering only one rooting compartment. Under study conditions, all species showed substantial Enight and HR (highest minus lowest soil water potential [Ψs] during a specified diel period). Suppressing Enight by canopy bagging increased HR during the nightly bagging period (HRN) for A. tridentata and H. anomalus by 73 and 33% respectively, but did not affect HRN by Q. laevis. Total daily HR (HRT) was positively correlated with the Ψs gradient between the rooting compartments, which was correlated with light and/or atmospheric vapour pressure deficit (VPDa) the prior day. For A. tridentata, HRT was negatively correlated with night‐time VPDa. Ecological implications of the impact of Enight on HR may include decreased plant productivity during dry seasons, altered ecosystem water flux patterns and reduced nutrient cycling in drying soils.
A single‐substrate model to interpret intra‐annual stable isotope signals in tree‐ring cellulose
Authors: OGÉE J. , BARBOUR M. M. , WINGATE L. , BERT D. , BOSC A. , STIEVENARD M. , LAMBROT C. , PIERRE M. , BARIAC T. , LOUSTAU D. , DEWAR R. C.
Published: April 2009

The carbon and oxygen stable isotope composition of wood cellulose (δ13Ccellulose and δ18Ocellulose, respectively) reveal well‐defined seasonal variations that contain valuable records of past climate, leaf gas exchange and carbon allocation dynamics within the trees. Here, we present a single‐substrate model for wood growth to interpret seasonal isotopic signals collected in an even‐aged maritime pine plantation growing in South‐west France, where climate, soil and flux variables were also monitored. Observed seasonal patterns in δ13Ccellulose and δ18Ocellulose were different between years and individuals, and mostly captured by the model, suggesting that the single‐substrate hypothesis is a good approximation for tree ring studies on Pinus pinaster, at least for the environmental conditions covered by this study. A sensitivity analysis revealed that the model was mostly affected by five isotopic discrimination factors and two leaf gas‐exchange parameters. Modelled early wood signals were also very sensitive to the date when cell wall thickening begins (twt). Our model could therefore be used to reconstruct twt time series and improve our understanding of how climate influences this key parameter of xylogenesis.
Developmental, genetic and environmental factors affect the expression of flavonoid genes, enzymes and metabolites in strawberry fruits*
Authors: CARBONE FABRIZIO , PREUSS ANJA , DE VOS RIC C. H. , D'AMICO ELEONORA , PERROTTA GAETANO , BOVY ARNAUD G. , MARTENS STEFAN , ROSATI CARLO
Published: April 2009

The influence of internal (genetic and developmental) and external (environmental) factors on levels of flavonoid gene transcripts, enzyme activity and metabolites was studied in fruit of six cultivated strawberry (Fragaria × ananassa Duch.) genotypes grown at two Italian locations. Gene expression and enzyme activity showed development‐ and genotype‐associated patterns, revealing gene coordination. Analysis clarified the regulation mechanism of the hydroxylation status of the B‐ring of the major flavonoid pools and pointed out examples of genotype‐specific post‐transcriptional regulation mechanisms and key steps of pathway regulation in strawberry fruits. Metabolite profiles were strongly affected by development and genotype. Flavan‐3‐ols, their proanthocyanidin (PA) derivatives and anthocyanins were the most abundant metabolites. Flavonol levels and PA‐associated traits (epicatechin/catechin ratio and mean degree of polymerization) showed significant environmental effects. Multivariate and correlation analyses determined the relationships among genes, enzymes and metabolites. The combined molecular and biochemical information elucidated more in depth the role of genetic and environmental factors on flavonoid metabolism during strawberry fruit development, highlighting the major impact of developmental processes, and revealing genotype‐dependent differences and environmental effects on PA‐related traits.
The current and future potential distribution of Melaleuca quinquenervia
Authors: WATT M S , KRITICOS D J , MANNING L K
Published: April 2009

Melaleuca quinquenervia (broad‐leaved paperbark) is a tree native to Australia, Papua New Guinea and New Caledonia that has become moderately to highly invasive in a number of countries over the last century. Although a synoptic view of the invasion would be of considerable use in devising appropriate control strategies, little effort has been applied to investigate the potential distribution of this invasive species. A climate suitability analysis was undertaken in this study, to assess the risk of geographic range expansion of M. quinquenervia under current climate and how this distribution will be modified by climate change during the 2080s. CLIMEX™ was used to infer the climatic requirements of M. quinquenervia from observations in both the native and exotic range. The accuracy of the developed model was assessed using independent naturalised observations of the species in Asia, Africa, Oceania and the Caribbean. Projections of climatic suitability indicate considerable scope for further invasion, with the most suitable areas occurring adjacent to existing populations in south‐east Asia, the Caribbean, Central and South America and the Gulf coast in southern USA. Under future climates, model projections indicate there will be a marked contraction of suitable habitat in most regions and a slight poleward range expansion within south‐eastern China, southern Europe and northern New Zealand.
Breastfeeding stimulates total and cow’s milk‐specific salivary IgA in infants
Authors: Piirainen Laura , Pesola Jouni , Pesola Ilkka , Komulainen Jorma , Vaarala Outi
Published: April 2009

Breastfeeding may increase the rate of mucosal maturation and IgA production. We sought to determine the effect of breastfeeding vs. formula‐feeding on the maturation of oral mucosa by measuring the salivary total antibodies and cow’s milk protein‐specific IgA. Fifty‐eight saliva samples were collected from 39 healthy, full term infants. At the age of 3 months (n = 25) eight infants received only breast milk and seventeen formula (cow’s milk based n = 10, hydrolysed n = 7) and breast milk; and at the age of 6 months (n = 33) eleven received breast milk, seventeen formula and breast milk and five were not breastfed any more (cow’s milk based n = 14, hydrolysed n = 8). Total IgA, IgG, IgM and protein, and β‐lactoglobulin specific IgA were measured from saliva with enzyme‐linked immunoassay (ELISA). The antibody results were proportioned to total protein. No differences in antibody levels between the feeding groups were found at 3 months of age. At 6 months, total IgA, total IgM and β‐lactoglobulin‐specific IgA were higher among the breastfed infants compared to those receiving formula as supplement to breast milk or not breastfed any more (breast milk vs. any formula p = 0.029, p = 0.015, p = 0.058; breast milk vs. cow’s milk formula p = 0.025, p = 0.044, p = 0.038). To conclude, breastfeeding stimulated the mucosal immune system to produce IgA to saliva, which is a marker for immunological maturation and likely provides protection against environmental antigens.
Effect of temporary changes in light intensity on carbon transport, partitioning and respiratory loss in young tomato seedlings raised under different light intensities
Authors: Nishizawa Takashi , Shishido Yoshihiro , Murakami Hiroharu
Published: April 2009

Tomato plants were grown under light intensities of 36 or 90 W m−2 [photosynthetically active radiation (PAR)], and then the light intensity was changed to 36, 90 or 180 W m−2 for 8 h to investigate the effect of temporary changes in light intensity on the carbon budget of photoassimilates from the third leaf using a 14CO2 steady‐state feeding method. In the plants that were raised under 90 W m−2, the photosynthetic rate increased when the light intensity was increased to 180 W m−2, whereas no increase occurred in the plants that were raised under 36 W m−2. Although the total amount of carbon fixed during the 8‐h light period showed a large difference between plants grown at the two initial light intensities, the proportion of carbon exported during the light period did not differ apparently, irrespective of the change in light intensity. However, the amount of carbon exported during the time course was higher in plants that were raised under 90 W m−2 than those raised under 36 W m−2, irrespective of the change in light intensity. The partitioning pattern of 14C‐photoassimilates was not changed by the change in light intensity, irrespective of whether the light intensity was increased or not. However, the amount of 14C‐photoassimilates accumulated in each part differed according to the two initial light intensities. The carbon transport from a source leaf was also investigated through a quantitative analysis of carbon balance.
Alternative oxidase: what information can protein sequence comparisons give us?
Authors: McDonald Allison E.
Published: April 2009

The finding that alternative oxidase (AOX) is present in most kingdoms of life has resulted in a large number of AOX sequences that are available for analyses. Multiple sequence alignments of AOX proteins from evolutionarily divergent organisms represent a valuable tool and can be used to identify amino acids and domains that may play a role in catalysis, membrane association and post‐translational regulation, especially when these data are coupled with the structural model for the enzyme. I validate the use of this approach by demonstrating that it detects the conserved glutamate and histidine residues in AOX that initially led to its identification as a di‐iron carboxylate protein and the generation of a structural model for the protein. A comparative analysis using a larger dataset identified 35 additional amino acids that are conserved in all AOXs examined, 30 of which have not been investigated to date. I hypothesize that these residues will be involved in the quinol terminal oxidase activity or membrane association of AOX. Major differences in AOX protein sequences between kingdoms are revealed, and it is hypothesized that two angiosperm‐specific domains may be responsible for the non‐covalent dimerization of AOX, whereas two indels in the aplastidic AOXs may play a role in their post‐translational regulation. A scheme for predicting whether a particular AOX protein will be recognized by the alternative oxidase monoclonal antibody generated against the AOX of Sauromatum guttatum (Voodoo lily) is presented. The number of functional sites in AOX is greater than expected, and determining the structure of AOX will prove extremely valuable to future research.
Study of the microcirculation in hDAF transgenic rat livers xenoperfused with human blood
Authors: Tomat Silvia , Russo Francesco Paolo , Guido Maria , Kechagias Georgios , Masier Annalisa , Calore Chiara , De Silvestro Giustina , Anegon Ignacio , Cozzi Emanuele , Calabrese Fiorella , Burra Patrizia
Published: April 2009

Abstract: Background:  The microcirculation was assessed in the livers of human decay accelerating factors (hDAF) and wild‐type transgenic rats by fluorescent intravital microscopy, histology and histomorphology to determine the benefits of hDAF expression for the microcirculation of a rat liver xenograft perfused with human blood.

Methods:  Male hDAF transgenic rats (group A; n = 20) and wild‐type Sprague–Dawley rats (group B; n = 20) were xenoperfused with human blood, while other male wild‐type Sprague–Dawley rats (group C; n = 10) were perfused with allogeneic blood. Following plasma and leukocyte staining with fluorescein sodium, and platelet staining with rhodamine, the right lobe of the liver was assessed by intravital microscopy, counting the numbers of perfused sinusoids and leukocytes adhering to the endothelium per mm2, and calculating the acinar perfusion index (Pi). The liver underwent histological assessment at the end of each experiment. Mean ± SEM values were calculated and the Mann–Whitney U‐test was used for statistical analysis.

Results:  The number of perfused sinusoids was higher in the group of hDAF rat livers (group A) and controls (group C) than in the group of non‐transgenic rat livers perfused with human blood (group B) (P < 0.05), although only group C still had a significantly more perfused sinusoids than the other groups after 90 min of perfusion (P < 0.05). The acinar perfusion index was higher in groups A and C than in group B (P < 0.05); here again, only group C still had a significantly higher Pi than group B after 90 min of perfusion (P < 0.05). There was a massive accumulation of leukocytes that peaked after 5 min and persisted throughout the perfusion in all three groups. Histology showed portal and subendothelial hepatic vein hemorrhage, necrosis and inflammatory reaction, which were particularly evident in group B.

Conclusion:  In our study, rat livers transgenic for hDAF were better protected against early tissue damage by perfusion with human blood, but this did not result in a longer xenograft survival.
Pathogenesis of coxsackievirus‐B5 acquired from intra‐renal porcine islet cell xenografts in diabetic mice
Authors: Myers Suzanne E. , LaRue Rebecca , Njenga Moses K. , Shaw Daniel P. , Love Brenda C.
Published: April 2009

Abstract: Background:  We previously demonstrated the ability of a human isolate of coxsackievirus‐B5 (CVB5) to infect productively adult porcine islet cells (PICs) in vitro. PICs infected with CVB5 remain viable, and upon transplantation reversed diabetes in C56BL/6 mice for up to 5 days.

Methods:  In the present work, we expanded this graft‐to‐host xenozoonosis model by examining the long‐term functionality of CVB5‐infected PIC xenografts in immunosuppressed mice. And, we characterized the pathogenesis of CVB5 infection in mice resulting from directional transmission of the virus from PIC xenografts to surrounding tissues in a mouse model for immunosuppressed human PIC xenograft recipients.

Results:  Both acutely (12 h) and chronically (72 h) infected PIC xenografts functioned in vivo to reverse diabetes in mice. The efficacy of both infected and un‐infected PICs was transient beyond 5 days post‐inoculation and the long‐term functionality of the grafts was compromised by host‐to‐graft rejection. CVB5‐infected PIC xenografts transmitted infectious virus to immunosuppressed recipient mice resulting in extensive histopathologic changes. The virus replicated in the heart, liver, spleen, kidney, pancreas, brain and skeletal muscle in higher levels in severe‐combined immunodeficient (SCID) mice that were directly inoculated with virus when compared to controls. In addition, infectious virus was recovered for up to 22 days after inoculation in SCID mice whereas it was only detected up to Day 4 PI in non‐SCID mice.

Conclusions:  Immunosuppressed PIC xenograft recipients may be more susceptible to infection with CVB5 which could target the xenograft leading to disseminated infection in the host.
Comparison of high‐performance liquid chromatography and bioassay of amphotericin B in serum
Authors: Hülsewede J. W. , Dermoumi Heide
Published: April 2009

Summary. For the determination of amphotericin B in serum a high‐performance liquid chromatography (HPLC) method using simple protein precipitation and an isocratic mobile phase as well as a plate diffusion bioassay are described. Using 5‐fluorocytosine‐resistant strain of Candida albicans and peptone in medium as an antagonist of 5‐fluorocytosine allows simple measurement of amphotericin B both in the absence and in the presence of 5‐fluorocytosine. The correlation coefficient (r) between bioassay and HPLC runs is 0.88. Generally, the biological determination gives slightly higher values of amphotericin B than the HPLC method. Both methods are useful for amphotericin B drug monitoring.

Zusammenfassung. Es werden für die Bestimmung von Amphotericin B im Serum eine HPLC‐Methode, die eine einfache Proteinfällung und eine isokratische mobile Phase verwendet, und ein Bioassay mittels eines Plattendiffusionstests beschrieben. Die Verwendung eines 5‐Fluorcytosin‐resistenten Stammes von Candida albicans und Pepton im Medium erlauben die Bestimmung von Amphotericin B sowohl in Abwesenheit als auch in Anwesenheit von 5‐Fluorcytosin in einfacher Weise. Die Korrelation zwischen Bioassay und der HPLC‐Methode beträgt r= 0.88. Im allgemeinen ergibt die biologische Methode etwas höhere Werte im Vergleich zur HPLC‐Bestimmung. Beide Methoden sind für die Bestimmung von Amphotericin‐B‐Serumspiegeln brauchbar.