bluuebunny/crossref_metadata_2025_split huggingface dataset:
Taurine reduces high glucose induced leukocyte–endothelial interactions via down‐regulation of ICAM‐1
Authors: Casey R. G. , Chen G. , Joyce M. , Kelly C. J. , Bouchier‐Hayes D. J. 
Published: March 2003

Taurine is a semiessential amino acid and naturally occurring antioxidant. One of its main roles is to protect tissues against attack by chlorinated oxidants particularly hypochlorous acid (HOCl). It is found in high concentrations in neutrophils and previous studies showed it possesses potent antimicrobial properties and attenuates high glucose induced endothelial cell apoptosis. In humans taurine has been shown to up‐regulate constitutive nitric oxide synthase (cNOS), a known cytoprotector.No reported studies to date have looked at the possible therapeutic role of taurine in preventing diabetic endothelial dysfunction. We therefore hypothesised that taurine would attenuate the microvascular changes associated with hyperglycaemia in an animal model through alteration of leucocyte–endothelial interactions.Male Sprague Dawley rats were randomised into control, hyperglycaemia, and taurine + hyperglycaemia groups. Taurine was gavaged (200 mg/kg) for 5 d prior to the experiment. Hyperglycaemia was established by intravenous infusion of 50% glucose. Blood glucose reached a steady state of 3 times baseline at 30 min. Using intravital microscopy leukocyte rolling, adhesion and transendothelial migration was determined in mesenteric postcapillary venules for 3 h. Intracellular adhesion molecule‐1 (ICAM‐1) was immunohistochemically graded using a scoring system to determine the expression in mesenteric tissue.Taurine pretreatment significantly attenuates leukocyte‐endothelial adhesion and transendothelial migration following acute hyperglycaemia but not leukocyte rolling velocity. The mechanism by which taurine protects against these effects is in part by inhibition of ICAM‐1 expression.

Results at 120 min (n = 5/group)
Control
Hyperglycaemia
Taurine + Hyperglycaemia

Leukocyte rolling

velocity (m/s)
49.5 (4.5)
30.4 (6.4)
45.4 (5.5)

Leukocyte

adhesion (/100(m))
2.25 (1.70)*
44.0 (10.5)
9.25 (2.3)*

Transendothelial

migration (/field)
6.5 (1.3)*
76.8 (20.7)
12.25 (5.9)*

Expression of

ICAM‐1 (at 180 mins)
1.05 (0.40)*
2.9 (0.4)
1.1 (0.3)*

Data are expressed as mean (SEM). Analysis with anova and post Scheffe hoc test.
*P < 0.05 vs. Hyperglycaemia.
Electrophysiological study of the rectosigmoid canal: evidence of a rectosigmoid sphincter
Authors: Shafik Ahmed , Mostafa Randa M. , Shafik Ali A. 
Published: March 2003

AbstractPrevious studies strongly suggest the presence of a sphincter at the rectosigmoid junction, an area with a mean length of 2.8 cm in adults, called the rectosigmoid canal (RSC). To find supporting evidence of a sphincteric function for the RSC, two recording electrodes were applied to each of the sigmoid colon (SC), RSC and rectum (R) in 11 subjects during operative repair of huge incisional hernias. The RSC, SC and R were individually stimulated by a further electrode and their pressures monitored by a three‐channel microtip catheter. The variables of the slow waves or pacesetter potentials, recorded at rest from the RSC and R, were significantly higher than those of the SC. While the frequency and conduction velocity of pacesetter potentials of the RSC and R were similar, the potential pacesetter amplitude of the RSC was significantly higher. The increase of the electrical activity and pressure upon electrostimulation was significantly greater in the RSC than that of the SC or R. Electrostimulation led to an increase in pressure of all three areas, the RSC increase being significantly the greatest. The greater increase of the electrical activity and pressure of the rectosigmoid canal upon electrostimulation, compared to that of the SC or R, strongly supports the presence of a rectosigmoid sphincter.
The functional anatomy of the human anterior talofibular ligament in relation to ankle sprains
Authors: Kumai T. , Takakura Y. , Rufai A. , Milz S. , Benjamin M. 
Published: March 2003

AbstractThe anterior talofibular ligament is the most commonly injured ligament in the ankle. Despite considerable interest in the clinical outcome of treatment protocols, we do not know whether the distinctive pattern of localization of the injuries relates to regional differences in the structure and molecular composition of the ligament. To address this issue, ligaments were examined by histology and immunohistochemistry. Differences in the structure of its two attachments (i.e. entheses) were evaluated with quantitative, morphometric techniques, and regional differences in the distribution of collagens, glycosaminoglycans and proteoglycans were determined qualitatively by immunolabelling. Morphometric analyses showed that bone density was less at the fibular attachment, but that enthesis fibrocartilage was more prominent. Immunohistochemistry revealed the presence of a fibrocartilage (containing type II collagen and aggrecan) at the site where the ligament wraps around the lateral talar articular cartilage in a plantarflexed and inverted foot: the fibrocartilage is regarded as an adaptation to resisting compression. We propose that avulsion fractures are less common at the talar end of the ligament because (1) bone density is greater here than at the fibular enthesis, and (2) stress is dissipated away from the talar enthesis by the ‘wrap‐around’ fibrocartilaginous character of the ligament near the talar articular facet.
Expression of parathyroid hormone‐related peptide (PTHrP) and its receptor (PTH1R) during the histogenesis of cartilage and bone in the chicken mandibular process
Authors: Zhao Qiong , Brauer Philip R. , Xiao Lei , McGuire Michael H. , Yee John A. 
Published: March 2003

AbstractThe purpose of this study was to examine the expression and actions of parathyroid hormone‐related protein (PTHrP) when skeletal histogenesis occurs in the chicken mandible. Prior to the appearance of skeletal tissues, PTHrP and PTH1R were co‐expressed by cells in the ectoderm, skeletal muscle, peripheral nerve and mesenchyme. Hyaline cartilage was first observed at HH stage 27 when many but not all chondroblasts expressed PTHrP and PTH1R. By stage 34, PTHrP and PTH1R were not detected in chondrocytes but were expressed in the perichondrium. Alkaline phosphatase (AP)‐positive preosteoblasts and woven bone appeared at stages 31 and 34, respectively. Preosteoblasts, osteoblasts and osteocytes co‐expressed PTHrP and PTH1R. Treatment with chicken PTHrP (1–36) increased cAMP in mesenchyme from stage 26 embryos. Continuous exposure to chicken PTHrP (1–36) for 14 days increased cartilage nodule number and decreased AP while intermittent exposure did not affect cartilage nodule number and increased AP in cultures of stage 26 mesenchymal cells. Adding a neutralizing anti‐PTHrP antibody to the cultures reduced cartilage nodule number and did not affect AP. These findings show that PTHrP and PTH1R are co‐expressed by extraskeletal and skeletal cells before and during skeletal tissue histogenesis, and that PTHrP may influence skeletal tissue histogenesis by affecting the differentiation of mandibular mesenchymal cells into chondroblasts and osteoblasts.
Ultrastructure of the placenta of the tammar wallaby, Macropus eugenii: comparison with the grey short‐tailed opossum, Monodelphis domestica
Authors: Freyer Claudia , Zeller Ulrich , Renfree Marilyn B. 
Published: March 2003

AbstractThe ultrastructure of the tammar placenta was studied throughout pregnancy. The uterine epithelium grows from a columnar to an enlarged, undulating epithelium between early gestation and mid‐gestation when the shell coat that surrounds the marsupial conceptus ruptures. Trophectoderm and uterine epithelium do not form syncytia, nor does invasion of the endometrium occur at any stage of pregnancy. Uterine secretion is provided to both the bilaminar and the trilaminar side of the yolk sac placenta up to birth. Fenestrations, abundant vesicles and lumenal processes of maternal capillaries, as well as deep basal folds of the uterine epithelium, suggest that there is transfer of hemotrophes adjacent to both parts of the yolk sac. In contrast, in the grey short‐tailed opossum, these structures are lacking. The yolk sacs of adjacent embryos fuse to form a common yolk sac cavity, thus losing most of the bilaminar yolk sac. The bilaminar and trilaminar components of the yolk sac placenta of the tammar are less different in structure and function than those of the grey short‐tailed opossum, but both types are fully functional placentas. The extended secretory phase of the tammar uterus and the maternal recognition of early pregnancy appear to be derived characters of macropodid marsupials.
Magnetic resonance imaging of the rat Harderian gland
Authors: Sbarbati Andrea , Calderan Laura , Nicolato Elena , Marzola Pasquina , Lunati Ernesto , Donatella Benati , Bernardi Paolo , Osculati Francesco 
Published: March 2003

AbstractThe intra‐orbital lachrymal gland (Harderian gland, or HG) of the female rat was studied by magnetic resonance imaging (MRI) to evaluate whether MRI can be used to visualize the gland in vivo and localized‐1H‐spectroscopy detect its lipid content. The results were correlated with post‐mortem anatomical sections, and with light and electron microscopy. On MRI, HG presented as a mass located between the ocular bulb and the orbit. In strongly T2W sequences the secretory structures had a reduced signal while intraparenchymal connective tissue was visible. T2‐quantitative maps values of HG (60.12 ± 8.15 ms, mean ± SD) were different from other tissues (i.e. muscular tissue, T2 = 44.79 ± 3.43 ms and olfactory bulb, T2 = 79.26 ± 4.25 ms). In contrast‐enhanced‐MRI, HG had a signal‐intensity‐drop of 0.074 ± 0.072 (mean ± SD), after injection of AMI‐25, significantly different from the muscle (0.17 ± 0.10). Localized MRI spectra gave a large part of the signal originating from fat protons, but with a significant percentage from water protons. At light and electron microscopy the lipid deposition appeared to be composed of low‐density material filling a large part of the cytoplasm, and the porphyrin aggregates were easily recognizable. The data demonstrate that an in vivo study of the HG was feasible and that high‐field MRI allowed analysis of the gross anatomy detecting the lipid content of the gland.
Covering the limb – formation of the integument
Authors: Byrne Carolyn , Hardman Matthew , Nield Kerry 
Published: March 2003

AbstractAn organism's outermost covering, the integument, has evolved to fulfil a diverse range of functions. Skin provides a physical barrier, an environment for immunological surveillance, and also performs a range of sensory, thermoregulatory and biosynthetic functions. Examination of the skin of limb digits reveals a range of skin types including the thickened hairless epidermis of the toe pads (palmar or plantar epidermis) and thinner epidermis between the hair follicles (interfollicular epidermis) of hairy skin. An important developmental function of skin is to give rise to a diverse group of appendages including hair follicles, with associated sebaceous glands (or feathers and scales in chick), eccrine sweat glands and the nail. A key question is how does this morphological variety arise from the single‐layered epithelium covering embryonic limb buds? This review will attempt to address this question by linking the extensive morphological/anatomical data on maturation of epidermis and its appendages with (1) current research into the range, plasticity and location of the putative epidermal stems cells; (2) molecular/microenvironmental regulation of epidermal stem cell lineages and lineage choice; and (3) regulation of the differentiation pathways, focusing on differentiation of the interfollicular epidermis.
Is sclerophylly of Mediterranean evergreens an adaptation to drought?
Authors: SALLEO S. , NARDINI A. , LO GULLO M. A. 
Published: March 2003

SUMMARYThe potential role of sclerophylly (leaf hardness and rigidity) in the control of leaf dehydration and rehydration was investigated in two sclerophylls (Viburnum tinus and Ilex aquifolium) and two non‐sclerophylls (Hedera helix ssp. helix and Sambucus nigra). After leaves were dehydrated in the pressure chamber, water transport from the apoplast (mainly consisting of xylem conduits and mechanical cells) to symplast was detected 15 min from pressure release, in terms of a spontaneous increase in leaf water potential (ϕ1). This ϕ1 increase was much larger in sclerophylls than in non‐sclerophylls.Positive pressures applied to leaves simulated the tensions developing in the leaf apoplast under water stress conditions, causing water to be expelled from leaf xylem conduits and mechanical cells and transferred to the leaf symplast, thus leading to symplast rehydration and to the consequent ϕ1 increase.No correlation was found between the leaf modulus of elasticity at full turgor or the degree of sclerophylly (in terms of the ratio of leaf d. wt to surface area) and the characteristic rehydration time of the leaves, i.e. between the two main parameters expressing the rigidity of the leaf blade and the rate of leaf rehydration. However, when changes in ϕ1 were measured as a function of leaf water deficit (RWD), equal ϕ1s corresponded with larger RWDs during leaf rehydration than during leaf dehydration in the two non‐sclerophylls. In particular, the two sclerophylls showed rehydration of their leaf apoplast and symplast completely and simultaneously. By contrast, the two non‐sclerophylls showed a persisting water loss, localized, it is likely, in their xylem conduits and mechanical cells.In other words, the two sclerophylls did not recover from water loss more rapidly than non‐sclerophylls but they recovered from xylem cavitation more completely. The major elasticity of the cavitation strain shown by the two sclerophylls studied was interpreted as of advantage to plants subjected to diurnal large drops in ϕ1 followed by nocturnal recovery. This is the case in Mediterranean sclerophylls growing in areas characterized by high humidity of the air condensing on the soil at night. The same mechanism of cavitation recovery, however, would be useless in very xeric areas.The hypothesis is advanced that sclerophylly of Mediterranean species may derive from similar anatomical structures developed in species formerly adapted to more humid environments which later migrated to more arid zones.
Components of pathozone behaviour
Authors: GILLIGAN C. A. , BAILEY D. J. 
Published: March 2003

SUMMARYPathozone behaviour of soil‐borne plant pathogenic fungi is characterized by curves for the change in probability of infection with distance of inoculum from a host. We identify three major components that give rise to the pathozone profile for infection efficiency: the germinability of inoculum, given that it occurs in the pathozone (P1), the growth of the resulting fungal colony outwards to make contact with the host (P2), and the infectivity of mycelium once contact is made (P3). The probability of infection (P) is then given by the product, P1×P2×P3. Using Raphanus sativus and two contrasting types of inoculum of Rhizoctonia solani as a model experimental system, we measured each of the three components by quantifying germinability, colony architecture (to determine the chance of contact by one or more hyphae) and the change in susceptibility over time as a measure of infectivity as mycelium arrives from different distances away. The germinability of inoculum is uniform across the pathozone whereas the probability of contact declines with distance, and the net effect of host susceptibility and infectivity increases. The characteristics of these components result in pathozone profiles that vary in shape. Infection efficiency can decline in an exponential or sigmoidal fashion with increasing distance from the host or follow a curve that rises close to the host and then falls asymptotically to zero with increasing distance. Colony architecture was summarized by the distribution of the furthest extent of hyphal growth amongst colonies growing out from single inoculum units (described, because of its asymmetrical pattern, by a gamma distribution) and by the radial density of hyphae on concentric circles at different distances from the centre of the colony (described by a negative binomial distribution with parameters changing with distance).The mechanistic model for the components of pathozone behaviour is tested by comparing the magnitude and shape of pathozone profiles predicted by the model with independent estimates for P obtained by placing inoculum at fixed distances from the host, and measuring the proportion of successful infections. The shape depends on the relative magnitudes and change with distance of the three components, P1, P2 and P3, which differed between the two types of inoculum. The profiles could be reproduced accurately when the probability of contact was based on the distribution and density of hyphae reaching the host rather than on the furthest extent of hyphal growth amongst colonies. The model is used to analyse the effects of replication and stochastic variability in the components of pathozone behaviour on the comparison of treatments for disease control.
Cyclic AMP, a possible regulator of glycolysis in the ectomycorrhizal fungus Amanita muscaria
Authors: HOFFMANN E. , WALLENDA T. , SCHAEFFER C. , HAMPP R. 
Published: March 2003

summaryThe amounts of cyclic AMP (cAMP), fructose‐2,6‐bisphosphate (F26BP), trehalose and glycogen were determined in cell suspension cultures of the ectomycorrhiza‐forming fungus Amanita muscaria (L. ex Fr.) Hooker. For the assay of cAMF a protocol was developed that enabled the detection of as little as 50 fmol of this secondary messenger by an enzyme‐linked immuno assay (EIA). Values varied from < 1 and up to 5 pmol cAMP mg1d. wt according to the age of the fungal culture. Typically, a transient increase in cAMP occurred after c. 4 d of culture of the fungus on glucose‐containing medium. This increase (up to 100%) was followed by the start of the logarithmic growth phase, and by a more persistent increase in F26BP. In parallel, glucose in the medium started to decrease, whilst the amounts of fungal carbohydrates, especially the disaccharide trehalose, increased, From these data we assume that a high initial rate of glucose uptake caused an increase in the fungal pools of storage carbohydrates and, via activation of an adenylate cyclase, of cAMP. According to data reported for yeast cells this should enhance the formation of F26BP by phosphorylation of relevant enzymes. In animal and yeast cells an increase in the concentration of F26BP stimulates glycolysis by activation of the ATP‐dependent phosphofructokinase (PFK). A. muscaria also possesses an F26BP activated PFK and, under conditions of symbiosis, host‐derived carbohydrates are supplied mainly in the form of glucose. The implications of these findings to the regulation of carbohydrate metabolism of symbiotic plant root/fungus structures (ectomycorrhiza) are discussed.
B chromosomes: a physiological enigma
Authors: BOUGOURD SUSAN M. , JONES R. NEIL 
Published: March 2003

summaryThe concept of the ‘nucleotype’ embraces aspects of the nuclear DNA that affect the phenotype other than through the coding sequences. In this context, we consider one particular situation, namely DNA variation due to the presence of supernumerary B chromosomes (Bs); these Bs, which are additional to the basic complement of A chromosomes, generate a spectrum of DNA amounts, and thus nucleotypes, within many species. We consider the physiological consequences of carrying extra chromosomes that appear by and large to lack coding sequences, and focus on two species with contrasting case histories: rye (Secale cereale L.) and chives (Allium schoenoprasum L.), which illustrate ‘selfish’ and ‘adaptive’ explanations of the persistence of B chromosomes.
Nitrogen and phosphorus acquisition by the mycelium of the ectomycorrhizal fungus Paxillus involutus and its effect on host nutrition
Authors: BRANDES BETTINA , GODBOLD DOUGLAS L. , KUHN ARND J. , JENTSCHKE GEORG 
Published: March 2003

The contribution of the extramatrical mycelium to N and P nutrition of mycorrhizal Norway spruce (Picea abies (L.) Karst.) was investigated. Seedlings either inoculated with Paxillus involutus (Batsch) Fr. or non‐mycorrhizal were grown in a two compartment sand culture system where hyphae were separated from roots by a 45 μm nylon net. Nutrient solution of the hyphal compartment contained either 1.8 mm NH4+ and 0.18 mm H2PO4− or no N and P. Aluminium added to the hyphal compartment as a tracer of mass flow was not detected in the plant compartment, indicating that measurements of N and P transfer by the mycelium were not biased by solute movement across the nylon net.The addition of N and P to the hyphal compartment markedly increased dry weight, N and P concentration and N and P content of mycorrhizal plants. Calculating uptake from the difference in input and output of nutrient in solution confirmed a hyphal contribution of 73% and 76% to total N and P uptake, respectively. Hyphal growth was increased at the site of nutrient solution input.
Ecotypic variation in selenium accumulation among populations of Stanleya pinnata
Authors: Feist Laura J. , Parker David R. 
Published: March 2003

Abstract• Ecotypic variation in selenium (Se) hyperaccumulation in plants is reported here among populations of Stanleya pinnata (Brassicaceae), which has a broad biogeographical range in the western USA.• In a glasshouse study, Se and sulfur accumulation were examined in 16 populations of S. pinnata. Plants grown from seed (collected from sites representing the species range) were subjected to five treatments differing in selenate (SeO42−) and sulfate (SO42−) concentrations.• The populations differed in shoot Se concentration by 1.4‐ to 3.6‐fold, depending on the treatment, and these concentrations were positively correlated with the indigenous soil Se levels at the collection sites. Shoot S concentrations varied by less than two‐fold, and did not correlate with the shoot Se levels. All populations accumulated SeO42− preferentially over SO42−. By contrast, Brassica juncea seedlings grown in a similar solution series consistently accumulated SO42− preferentially over SeO42−. Biomass production differed up to three‐fold between populations.•  S. pinnata is a primary Se accumulator, but populations exhibit significant ecotypic differences in Se accumulation. Environmental concerns about Se are common, and the broad adaptation of S. pinnata makes it an attractive candidate for phytoremediation.
Nutritive value and the nitrogen dynamics of Trifolium subterraneum and Phalaris aquatica under warmer, high CO2 conditions
Authors: Lilley J. M. , Bolger T. P. , Peoples M. B. , Gifford R. M. 
Published: March 2003

Summary

Will changes in nutritive values and N‐relations offset initial gains in forage productivity under potential climate change observed for grass–legume pastures of south‐eastern Australia?
Herbage nutritive value and symbiotic nitrogen fixation were investigated for pure and mixed swards of subterranean clover (Trifolium subterraneum) and phalaris (Phalaris aquatica) in field tunnels at ambient and 690 µmol mol−1 CO2 concentrations and at ambient and warmed (+3.4°C) air temperatures.
Elevated CO2 increased the nonstructural carbohydrate content of herbage whereas warming tended to decrease it. These effects were mainly on soluble carbohydrates in phalaris and starch in clover herbage. The N concentration of both species was decreased by elevated CO2 but unaffected by warming. The proportion of clover‐N derived from N2 fixation was increased by 12% under elevated CO2 but decreased by 6% under warming.
Concurrent warming and high‐CO2 conditions are expected to lead to improved herbage nutritive value for ruminants due to increased nonstructural soluble carbohydrate content. Longer term effects on nutritive value and N‐dynamics via species persistence and competition require further study.