bluuebunny/crossref_metadata_2025 huggingface dataset:
Host specificity and exchange of intestinal helminths among four species of grebes (Podicipedidae)
Authors: Stock T. M. , Holmes John C.
Published: April 2008

The infracommunities of intestinal helminths in 96 birds belonging to four species of grebes taken from lakes in Alberta were examined for patterns of species co-occurrence and relative abundance. Infracommunities were large (averages of 360–3640 worms) and complex (averages of 6.4–10.7 species). Three species of grebes (Aechmophorus occidentalis, Podiceps grisegena, P. nigricollis) had distinctive infracommunities, each characterized by a set (5–10) of frequent and numerous core helminth species, which regularly co-occurred with a consistent rank order of numbers. Infracommunities in Podiceps auritus overlapped those of the other two species of Podiceps and had few (2) core species. Most (11 of 14) core species are specialists in grebes, but only one was limited to a single host species. Most were shared among hosts, with the bulk of the population of each occurring in one host species. Sharing was particularly significant between the large, fish-eating grebes (A. occidentalis and P. grisegena) and between the smaller, mainly invertebrate-eating grebes (P. nigricollis and P. auritus). Host specificity and the pattern of exchange of helminths, mediated by the differentiated but overlapping host food habits, were important determinants of enteric helminth community structure.
The chromosome numbers of five North American and European leech species
Authors: Davies Ronald W. , Singhal R. N.
Published: April 2008

Chromosome counts were obtained for four glossiphoniid species belonging to three genera (Glossiphonia, Theromyzon, Placobdella) and for one erpobdellid species (Dina lineata) of freshwater leeches. Theromyzon rude, which has a Palaearctic distribution, had seven bivalents at prophase I and metaphase I, while the Holarctic T. tessulatum had eight bivalents, giving diploid chromosome numbers of 14 and 16, respectively. Placobdella papillifera from Alberta had a chromosome number of 2n = 24 and Glossiphonia complanata from Alberta and England had chromosome counts of 2n = 28. At prophase I and metaphase I nine bivalents occurred in the majority of the nuclei of Dina lineata. These findings are discussed in relation to the chromosome evolution and phylogenetic schemes proposed by previous authors.
Echthrogaleus disciarai sp.nov. (Siphonostomatoida: Pandaridae), a parasitic copepod of the devil ray Mobula lucasana Beebe and Tee Van, 1938 from the Sea of Cortez
Authors: Benz George W. , Deets Gregory B.
Published: April 2008

Echthrogaleus disciarai sp.nov. (Siphonostomatoida: Pandaridae) is described from female and male specimens found on the pectoral fins of the devil ray Mobula lucasana in the Sea of Cortez. The maxillipeds of E. disciarai sp.nov. are particularly distinctive because of both their large relative size and their morphology.
A comparison of methodological approaches to the subfamilial classification of the Naididae (Oligochaeta)
Authors: Nemec A. F. L. , Brinkhurst R. O.
Published: April 2008

A data matrix of 23 generic or subgeneric taxa versus 24 characters and a shorter matrix of 15 characters were analyzed by means of ordination, cluster analyses, parsimony, and compatibility methods (the last two of which are phylogenetic tree reconstruction methods) and the results were compared inter alia and with traditional methods. Various measures of fit for evaluating the parsimony methods were employed. There were few compatible characters in the data set, and much homoplasy, but most analyses separated a group based on Stylaria from the rest of the family, which could then be separated into four groups, recognized here for the first time as tribes (Naidini, Derini, Pristinini, and Chaetogastrini). There was less consistency of results within these groups. Modern methods produced results that do not conflict with traditional groupings. The Jaccard coefficient minimizes the significance of symplesiomorphy and complete linkage avoids chaining effects and corresponds to actual similarities, unlike single or average linkage methods, respectively. Ordination complements cluster analysis. The Wagner parsimony method was superior to the less flexible Camin–Sokal approach and produced better measure of fit statistics. All of the aforementioned methods contain areas susceptible to subjective decisions but, nevertheless, they lead to a complete disclosure of both the methods used and the assumptions made, and facilitate objective hypothesis testing rather than the presentation of conflicting phylogenies based on the different, undisclosed premises of manual approaches.
Simuliidae (Diptera) of Rendalen, Norway. Description of a new species of Eusimulium (Hellichiella) and previously undescribed stages of Eusimulium rendalense and Eusimulium fallisi
Authors: Golini Victor I.
Published: April 2008

Eusimulium (Hellichiella) usovae n.sp. is described in the larva, pupa, and adult female and male. The larva, pupa, and male of Eusimulium rendalense Golini and pupa of Eusimulium fallisi Golini are described for the first time. These three species are closely related; the first two are distinguished by a few consistent characters in all their developmental stages. Eusimulium fallisi is distinguished in the female from the other two species; its larva and adult male are still unknown. Keys distinguishing the stages of these species are provided. The immature stages of these species occur sympatrically in sedge – Sphagnum bog – fens, in slow water with currents of 1 to 30 cm/s.
Le caryotype de la Hyène rayée, Hyaena hyaena
Authors: Bérubé-Genest Fernande , Morisset Pierre , Patenaude Robert P.
Published: April 2008

The chromosomes of the striped hyena (Hyaena hyaena) were studied from fibroblast and lymphocyte cultures. The diploid number is 40, including 32 metacentric–submetacentric and 6 acrocentric autosomes. The gonosomatic formula is of the XY type. The X, a medium-sized metacentric, can be unambiguously identified through its G-banding pattern. The Y is a minute acrocentric. A pair of submetacentric marker chromosomes is also present.
A new species of Telorchis Luehe, 1899 (Digenea: Telorchiidae) from the yellow-bellied turtle, Chrysemys scripta scripta Schoepff, 1792
Authors: Macdonald Cheryl A. , Brooks Daniel R.
Published: April 2008

A new species of Telorchis (Telorchis scabrae) is described. It most closely resembles T. chelopi by possessing a large, muscular cirrus sac and a large, robust body. It differs from all other species in the genus by possessing a genital pore that is ventral to the left cecum, rather than medial or submedial, or dorsolateral to the cecum.
Escalation of an asymmetric contest: mortality resulting from mate competition in Atlantic salmon, Salmo salar
Authors: Hutchings Jeffrey A. , Myers Ransom A.
Published: April 2008

Male anadromous Atlantic salmon, Salmo salar, fatally injured mature male parr during spawning. The wound consisted of three parallel cuts which exposed musculature on one side of the parr either directly below or immediately posterior to the base of the dorsal fin. The spacing of the cuts matched the spacing of the anadromous male's lingual and mandibular teeth. The wounding of parr in this manner is consistent with the observation of larger males vigorously shaking smaller males between their jaws. Mortality resulting from anadromous male aggression contributes to the low survival of mature male parr. Given the high mortality associated with parr maturation, if male parr must compete with anadromous males and other parr at all spawning sites, parr may be willing to risk escalated contests during mate competition with anadromous males to fertilize eggs.
Lenticular junctions: a form of cell contact between hypodermal cells in the nematode Trichinella spiralis
Authors: Wright K. A. , Hong H. , Shivers R. R.
Published: April 2008

The intercellular junctions between hypodermal cells of the muscle larva of the nematode Trichinella spiralis were examined by thin section and freeze-fracture techniques of electron microscopy. The spacing between membranes varied greatly and the intercellular space contained dense material. In freeze-fractures, the P-fracture face had very few particles (especially compared with the rest of the lateral membranes), and possessed raised areas of an approximately lenticular shape. These areas were not outlined by particles. It is speculated that the form of the membranes is maintained by domains of phospholipids of conical and inverted cone shapes. These junctions likely have adhering and occluding functions.
Collagen phagocytosis is regulated by the guanine nucleotide exchange factor Vav2
Authors: Arora P. D. , Marignani P. A. , McCulloch C. A.
Published: April 2008

Collagen phagocytosis is a crucial α2β1-integrin-dependent process that mediates extracellular matrix remodeling by fibroblasts. We showed previously that after initial contact with collagen, activated Rac1 accelerates collagen phagocytosis but the Rac guanine nucleotide exchange factors (GEFs) that regulate Rac are not defined. We examined here the GEFs that regulate collagen phagocytosis in mouse fibroblasts. Collagen binding enhanced Rac1 activity (5–20 min) but not Cdc42 or RhoA activity. Analysis of collagen bead-associated proteins showed enrichment with Vav2, which correlated temporally with increased Rac1 activity. Knockdown of Vav2 prevented Rac activation, recruitment of Rac1 to collagen bead binding sites, and collagen bead binding, but knockdown of Sos-1 or β-Pix had no effect on Rac activation or collagen binding. Vav2 was associated with the nucleotide-free Rac1 mutant (G15ARac1) after collagen binding. Collagen bead binding promoted phosphorylation of Vav2, which temporally correlated with Rac1 activation and which required Src kinase activity. Blockage of Src activity prevented collagen bead-induced Rac activation and collagen bead binding. Collectively these data indicate that Vav2 regulates the Rac1 activity associated with the binding step of collagen phagocytosis.
Complex regulation of store-operated Ca2+entry pathway by PKC-ε in vascular SMCs
Authors: Smani Tarik , Patel Tina , Bolotina Victoria M.
Published: April 2008

The role of PKC in the regulation of store-operated Ca2+entry (SOCE) is rather controversial. Here, we used Ca2+-imaging, biochemical, pharmacological, and molecular techniques to test if Ca2+-independent PLA2β (iPLA2β), one of the transducers of the signal from depleted stores to plasma membrane channels, may be a target for the complex regulation of SOCE by PKC and diacylglycerol (DAG) in rabbit aortic smooth muscle cells (SMCs). We found that the inhibition of PKC with chelerythrine resulted in significant inhibition of thapsigargin (TG)-induced SOCE in proliferating SMCs. Activation of PKC by the diacylglycerol analog 1-oleoyl-2-acetyl- sn-glycerol (OAG) caused a significant depletion of intracellular Ca2+stores and triggered Ca2+influx that was similar to TG-induced SOCE. OAG and TG both produced a PKC-dependent activation of iPLA2β and Ca2+entry that were absent in SMCs in which iPLA2β was inhibited by a specific chiral enantiomer of bromoenol lactone ( S-BEL). Moreover, we found that PKC regulates TG- and OAG-induced Ca2+entry only in proliferating SMCs, which correlates with the expression of the specific PKC-ε isoform. Molecular downregulation of PKC-ε impaired TG- and OAG-induced Ca2+influx in proliferating SMCs but had no effect in confluent SMCs. Our results demonstrate that DAG (or OAG) can affect SOCE via multiple mechanisms, which may involve the depletion of Ca2+stores as well as direct PKC-ε-dependent activation of iPLA2β, resulting in a complex regulation of SOCE in proliferating and confluent SMCs.
The effect of angiotensin II on intracellular pH is mediated by AT1 receptor translocation
Authors: Thieme Karina , Eguti Débora Mai N. , Mello-Aires Margarida , Oliveira-Souza Maria
Published: April 2008

The effect of ANG II on intracellular pH (pHi) recovery rate and AT1 receptor translocation was investigated in transfected MDCK cells. The pHi recovery rate was evaluated by fluorescence microscopy using the fluorescent probe BCECF-AM. The human angiotensin II receptor isoform 1 (hAT1) translocation was analyzed by immunofluorescence and confocal microscope. Our data show that transfected cells in control situation have a pHi recovery rate of 0.219 ± 0.017 pH U/min ( n = 11). This value was similar to nontransfected cells [0.211 ± 0.009 pH U/min ( n = 12)]. Both values were significantly increased with ANG II (10−9 M) but not with ANG II (10−6 M). Losartan (10−7 M) and dimethyl-BAPTA-AM (10−7 M) decreased significantly the stimulatory effect of ANG II (10−9 M) and induced an increase in Na+/H+ exchanger 1 (NHE-1) activity with ANG II (10−6 M). Immunofluorescence studies indicated that in control situation, the hAT1 receptor was predominantly expressed in cytosol. However, it was translocated to plasma membrane with ANG II (10−9 M) and internalized with ANG II (10−6 M). Losartan (10−7 M) induced hAT1 translocation to plasma membrane in all studied groups. Dimethyl-BAPTA-AM (10−7 M) did not change the effect of ANG II (10−9 M) on the hAT1 receptor distribution but induced its accumulation at plasma membrane in cells treated with ANG II (10−6 M). With ionomycin (10−6 M), the receptor was accumulated in cytosol. The results indicate that, in MDCK cells, the effect of ANG II on NHE-1 activity is associated with ligand binding to AT1 receptor and intracellular signaling events related to AT1 translocation.
Shear stress influences spatial variations in vascular Mn-SOD expression: implication for LDL nitration
Authors: Ai Lisong , Rouhanizadeh Mahsa , Wu Joseph C. , Takabe Wakako , Yu Hongyu , Alavi Mohammad , Li Rongsong , Chu Yi , Miller Jordan , Heistad Donald D. , Hsiai Tzung K.
Published: April 2008

Fluid shear stress modulates vascular production of endothelial superoxide anion (O2·−) and nitric oxide (·NO). Whether the characteristics of shear stress influence the spatial variations in mitochondrial manganese superoxide dismutase (Mn-SOD) expression in vasculatures is not well defined. We constructed a three-dimensional computational fluid dynamics model simulating spatial variations in shear stress at the arterial bifurcation. In parallel, explants of arterial bifurcations were sectioned from the human left main coronary bifurcation and right coronary arteries for immunohistolocalization of Mn-SOD expression. We demonstrated that Mn-SOD staining was prominent in the pulsatile shear stress (PSS)-exposed and atheroprotective regions, but it was nearly absent in the oscillatory shear stress (OSS)-exposed regions and lateral wall of arterial bifurcation. In cultured bovine aortic endothelial cells, PSS at mean shear stress (τave) of 23 dyn/cm2 upregulated Mn-SOD mRNA expression at a higher level than did OSS at τave = 0.02 dyn/cm2 ± 3.0 dyn·cm−2·s−1 and at 1 Hz (PSS by 11.3 ± 0.4-fold vs. OSS by 5.0 ± 0.5-fold vs. static condition; P < 0.05, n = 4). By liquid chromatography and tandem mass spectrometry, it was found that PSS decreased the extent of low-density lipoprotein (LDL) nitration, whereas OSS increased nitration ( P < 0.05, n = 4). In the presence of LDL, treatment with Mn-SOD small interfering RNA increased intracellular nitrotyrosine level ( P < 0.5, n = 4), a fingerprint for nitrotyrosine formation. Our findings indicate that shear stress in the atheroprone versus atheroprotective regions regulates spatial variations in mitochondrial Mn-SOD expression with an implication for modulating LDL nitration.
Hypoxia enhances lysosomal TNF-α degradation in mouse peritoneal macrophages
Authors: Lahat Nitza , Rahat Michal A. , Kinarty Amalia , Weiss-Cerem Lea , Pinchevski Sigalit , Bitterman Haim
Published: April 2008

Infection, simulated by lipopolysaccharide (LPS), is a potent stimulator of tumor necrosis factor-α (TNF-α) production, and hypoxia often synergizes with LPS to induce higher levels of the secreted cytokine. However, we show that in primary mouse peritoneal macrophages and in three mouse peritoneal macrophage cell lines (RAW 264.7, J774A.1, and PMJ-2R), hypoxia (O2 < 0.3%) reduces the secretion of LPS-induced TNF-α ( P < 0.01). In RAW 264.7 cells this reduction was not regulated transcriptionally as TNF-α mRNA levels remained unchanged. Rather, hypoxia and LPS reduced the intracellular levels of TNF-α by twofold ( P < 0.01) by enhancing its degradation in the lysosomes and inhibiting its secretion via secretory lysosomes, as shown by confocal microscopy and verified by the use of the lysosome inhibitor Bafilomycin A1. In addition, although hypoxia did not change the accumulation of the soluble receptor TNF-RII, it increased its binding to the secreted TNF-α by twofold ( P < 0.05). We suggest that these two posttranslational regulatory checkpoints coexist in hypoxia and may partially explain the reduced secretion and diminished biological activity of TNF-α in hypoxic peritoneal macrophages.
5-HT4 receptor activation facilitates recovery from synaptic rundown and increases transmitter release from single varicosities of myenteric neurons
Authors: Ren Jianhua , Zhou Xiaoping , Galligan James J.
Published: April 2008

5-HT4 receptor agonists facilitate synaptic transmission in the enteric nervous system, and these drugs are used to treat constipation. In the present study, we investigated the effects of the 5-HT4 receptor agonist, renzapride, on rundown and recovery of fast excitatory postsynaptic potentials (fEPSPs) during and after trains of stimulation and on transmitter release from individual myenteric neuronal varicosities. Intracellular electrophysiological methods were used to record fEPSPs from neurons in longitudinal muscle myenteric plexus preparations of guinea pig ileum in vitro. During trains of supramaximal electrical stimulation (10 Hz, 2 s), fEPSP amplitude declined (time constant = 0.6 ± 0.1 s) from 17 ± 2 mV to 0.7 ± 0.3 mV. Renzapride (0.1 μM) did not change the time constant for fEPSP rundown, but it decreased the time constant for recovery of fEPSP amplitude after the stimulus train from 7 ± 2 s to 1.6 ± 0.2 s ( P < 0.05). 5-HT (0.1 μM) also increased fEPSPs and facilitated recovery from rundown. The adenylate cyclase activator, forskolin (1 μM), mimicked the actions of renzapride and 5-HT, whereas H-89, a protein kinase A (PKA) inhibitor, blocked the effects of renzapride. We used nicotinic acetylcholine receptor containing outside-out patches obtained from myenteric neurons maintained in primary culture to detect acetylcholine release from single varicosities. Renzapride (0.1 μM) increased release probability twofold. We conclude that 5-HT4 receptors activate the adenylyl cyclase-PKA pathway to increase acetylcholine release from single varicosities and to accelerate recovery from synaptic rundown. These responses may contribute to the prokinetic actions of 5-HT4 receptor agonists.
Sprint interval and traditional endurance training induce similar improvements in peripheral arterial stiffness and flow-mediated dilation in healthy humans
Authors: Rakobowchuk Mark , Tanguay Sophie , Burgomaster Kirsten A. , Howarth Krista R. , Gibala Martin J. , MacDonald Maureen J.
Published: April 2008

Low-volume sprint interval training (SIT), or repeated sessions of brief, intense intermittent exercise, elicits metabolic adaptations that resemble traditional high-volume endurance training (ET). The effects of these different forms of exercise training on vascular structure and function remain largely unexplored. To test the hypothesis that SIT and ET would similarly improve peripheral artery distensibility and endothelial function and central artery distensibility, we recruited 20 healthy untrained subjects (age: 23.3 ± 2.8 yr) and had them perform 6 wk of SIT or ET ( n = 5 men and 5 women per group). The SIT group completed four to six 30-s “all-out” Wingate tests separated by 4.5 min of recovery 3 days/wk. The ET group completed 40–60 min of cycling at 65% of their peak oxygen uptake (V̇o2peak) 5 days/wk. Popliteal endothelial function, both relative and normalized to shear stimulus, was improved after training in both groups (main effect for time, P < 0.05). Carotid artery distensibility was not statistically altered by training ( P = 0.29) in either group; however, popliteal artery distensibility was improved in both groups to the same degree (main effect, P < 0.05). We conclude that SIT is a time-efficient strategy to elicit improvements in peripheral vascular structure and function that are comparable to ET. However, alterations in central artery distensibility may require a longer training stimuli and/or greater initial vascular stiffness than observed in this group of healthy subjects.
Intergenic bidirectional promoter and cooperative regulation of the IIx and IIb MHC genes in fast skeletal muscle
Authors: Rinaldi Chiara , Haddad Fadia , Bodell Paul W. , Qin Anqi X. , Jiang Weihua , Baldwin Kenneth M.
Published: April 2008

This study investigated the dynamic regulation of IIx-IIb MHC genes in the fast white medial gastrocnemius (WMG) muscle in response to intermittent resistance exercise training (RE), a model associated with a rapid shift from IIb to IIx expression ( 11 ). We investigated the effect of 4 days of RE on the transcriptional activity across the skeletal MHC gene locus in the WMG in female Sprague-Dawley rats. Our results show that RE resulted in significant shifts from IIb to IIx observed at both the pre-mRNA and mRNA levels. An antisense RNA (xII NAT) was detected in the intergenic (IG) region between IIx and IIb, extending across the entire IIx gene and into its promoter. The expression of the xII NAT was positively correlated with IIb pre-mRNA ( R = +0.8), and negatively correlated with IIx pre-mRNA ( R = −0.8). Transcription mapping of the IIx–IIb IG region revealed the generation of sense IIb and xII NATs from a single promoter region. This bidirectional promoter is highly conserved among species and contains several regulatory elements that may be implicated in its regulation. These results suggest that the IIx and the IIb genes are physically and functionally linked via the bidirectional promoter. In order for the IIx MHC gene to be regulated, a feedback mechanism from the IG xII NAT is needed. In conclusion, the IG bidirectional promoter generating antisense RNA appears to be essential for the coordinated regulation of the skeletal muscle MHC genes during dynamic phenotype shifts.
Angiotensin and NMDA receptors in the median preoptic nucleus mediate hemodynamic response patterns to stress
Authors: Schwartz Julie A. , Reilly Nichole S. , Knuepfer Mark M.
Published: April 2008

The brain renin-angiotensin system plays an important role in the regulation of arterial pressure in response to stress, in part due to activation of AT1receptors in the hypothalamic median preoptic nucleus (MnPO) by endogenous angiotensin II (ANG II). N-methyl-d-aspartate (NMDA) receptors are also involved in the angiotensinergic signaling pathway through the MnPO. We investigated whether AT1and NMDA receptors in the MnPO are responsible for variable hemodynamic response patterns to stress. Cocaine or startle with cold water evoked a pressor response in Sprague-Dawley rats due, in some rats [vascular responders (VR)], to a large increase in systemic vascular resistance (SVR) and, in other rats [mixed responders (MR)], to small increases in SVR and cardiac output (CO). Microinjection of the GABAAagonist muscimol into the MnPO to block synaptic transmission attenuated the cocaine- or stress-induced increase in SVR and the decrease in CO seen in VR without altering either response in MR. Likewise, administration of either an AT1receptor antagonist, losartan, or an NMDA receptor antagonist, MK-801, attenuated the increase in SVR and the decrease in CO in VR in response to either cocaine (losartan and MK-801) or startle with cold water (losartan) without altering either response in MR. We propose that the MnPO is responsible for greater SVR responses in VR and that AT1and NMDA receptors play an important role in greater SVR responses in VR. These data provide additional support for the critical role of the MnPO in cardiovascular responses to stress.
High resting triacylglycerol turnover of rainbow trout exceeds the energy requirements of endurance swimming
Authors: Magnoni Leonardo , Vaillancourt Eric , Weber Jean-Michel
Published: April 2008

Fish may use lipoproteins instead of albumin-bound fatty acids to fuel endurance exercise, but lipoprotein kinetics have never been measured in ectotherms. In vivo bolus injections of labeled very-low-density lipoproteins (3H-VLDL labeled in vivo from donor fish) and continuous infusions of Intralipid (3H-labeled artificial emulsion) were used to investigate the effects of prolonged exercise (6 h at 1.5 body length/s) and heparin (600 U/kg) on the turnover rate of circulating triacylglycerol (TAG) in rainbow trout. We hypothesized that swimming would stimulate TAG turnover rate to fuel working muscles and that heparin would reduce flux by releasing lipoprotein lipase (LPL) from endothelial cells. Results from both tracer methods show that the baseline TAG turnover rate of trout ranges from 24 to 49 μmol TAG·kg−1·min−1and exceeds all values measured to date in endotherms. More important, this high resting turnover rate is not stimulated during swimming, because it can already cover several times the energy requirements of locomotion. The fact that heparin causes a 50% decrease in baseline TAG turnover rate suggests that fish LPL must be bound to the endothelium for normal tissue uptake of fatty acids supplied by lipoproteins, as in mammals. We propose that the high resting TAG turnover rate of rainbow trout could be needed by ectotherms for rapid restructuring of membrane phospholipids. The continuous tracer infusion method implemented here could be a versatile tool to investigate the potential role of lipoproteins in providing fatty acids for rapid homeoviscous adaptation.
Role of AQP1 in endotoxemia-induced acute kidney injury
Authors: Wang Weidong , Li Chunling , Summer Sandra N. , Falk Sandor , Wang Wei , Ljubanovic Danica , Schrier Robert W.
Published: April 2008

The effect of endotoxemia (lipopolysaccharide, 2.5 mg/kg ip) was investigated in aquaporin (AQP) 1 knockout (KO) compared with wild-type (WT) mice. At baseline, KO mice exhibited higher water intake (WI) and urine output (UO). After endotoxemia, WI and UO remained higher in the KO than WT mice, and urine osmolality was lower. The higher serum osmolality in AQP1-KO mice during endotoxemia was associated with higher AQP2 (133 ± 8 vs. 100 ± 3%, P < 0.01), AQP3 (140 ± 8 vs. 100 ± 4%, P < 0.001) and Na+-K+-2Cl−cotransporter type 2 (NKCC2; 152 ± 14 vs. 100 ± 15%, P < 0.05) expression than that in WT mice. These responses during endotoxemia in the AQP1-KO mice compared with WT were associated with lower glomerular filtration rate (GFR) (69 ± 8 vs. 96 ± 8 ml/min, P < 0.05) and renal blood flow (0.77 ± 0.1 vs. 1.01 ± 0.1 ml/min, P < 0.01). Urinary sodium excretion and fractional sodium excretion were higher in KO compared with WT mice in endotoxemia and were accompanied by more severe tubular injury. With water repletion and comparable serum osmolalities, GFR was still lower in KO (57 ± 13 vs. 120 ± 6 ml/min, P < 0.01) compared with WT during endotoxemia. The abundance of AQP2 and AQP3 protein in KO mice was not different from WT mice; however, NKCC2, Na+/H+exchanger type 3, and fractional sodium excretion remained higher in KO compared with WT. Thus the polyuria in AQP1-KO mice does not protect against endotoxemia-induced acute kidney injury but rather absence of AQP1 predisposed to enhanced endotoximic renal injury.
The phosphorylation state of serine 256 is dominant over that of serine 261 in the regulation of AQP2 trafficking in renal epithelial cells
Authors: Lu Hua Jenny , Matsuzaki Toshiyuki , Bouley Richard , Hasler Udo , Qin Quan-Hong , Brown Dennis
Published: April 2008

Phosphorylation of serine 256 (S256) plays a critical role in vasopressin (VP)-mediated membrane accumulation of aquaporin-2 (AQP2). Recently, phosphorylation of serine 261 was also reported, raising the possibility that it has a role in AQP2 trafficking. We addressed this issue using transfected LLC-PK1cells that express point mutations of AQP2 S261 and S256, mimicking the phosphorylated (S to D) or dephosphorylated (S to A) states of these residues. Both AQP2 (S261A) and AQP2 (S261D) were located in the perinuclear cytoplasm without stimulation but, like wild-type AQP2, they both accumulated on the plasma membrane after 20-min exposure to VP or forskolin. Following membrane accumulation, S261A, S261D, and wild-type AQP2 reinternalization was complete over a similar time frame, between 30 and 60 min after VP washout. Using various combinations of point mutations, we showed that the phosphorylation state of S256 is dominant with respect to AQP2 behavior; AQP2 membrane accumulation and internalization were not detectably affected by the phosphorylation state of S261. Finally, blocking AQP2 endocytosis by methyl-β-cyclodextrin caused membrane accumulation of AQP2 in cells expressing either a single S-A mutation or double mutations of S256 and S261, although as previously reported, the S256D mutation was always present at the cell surface. This suggests that constitutive recycling of AQP2 was not modified by the phosphorylation state of S261. Together, our data indicate that the phosphorylation state of AQP2 at S261 does not detectably affect regulated or constitutive trafficking of AQP2. The potential role of S261 phosphorylation/dephosphorylation in vasopressin action remains to be determined.
Potent myofiber hypertrophy during resistance training in humans is associated with satellite cell-mediated myonuclear addition: a cluster analysis
Authors: Petrella John K. , Kim Jeong-su , Mayhew David L. , Cross James M. , Bamman Marcas M.
Published: April 2008

A present debate in muscle biology is whether myonuclear addition is required during skeletal muscle hypertrophy. We utilized K-means cluster analysis to classify 66 humans after 16 wk of knee extensor resistance training as extreme (Xtr, n = 17), modest (Mod, n = 32), or nonresponders (Non, n = 17) based on myofiber hypertrophy, which averaged 58, 28, and 0%, respectively (Bamman MM, Petrella JK, Kim JS, Mayhew DL, Cross JM. J Appl Physiol 102: 2232–2239, 2007). We hypothesized that robust hypertrophy seen in Xtr was driven by superior satellite cell (SC) activation and myonuclear addition. Vastus lateralis biopsies were obtained at baseline and week 16. SCs were identified immunohistochemically by surface expression of neural cell adhesion molecule. At baseline, myofiber size did not differ among clusters; however, the SC population was greater in Xtr ( P < 0.01) than both Mod and Non, suggesting superior basal myogenic potential. SC number increased robustly during training in Xtr only (117%; P < 0.001). Myonuclear addition occurred in Mod (9%; P < 0.05) and was most effectively accomplished in Xtr (26%; P < 0.001). After training, Xtr had more myonuclei per fiber than Non (23%; P < 0.05) and tended to have more than Mod (19%; P = 0.056). Both Xtr and Mod expanded the myonuclear domain to meet (Mod) or exceed (Xtr) 2,000 μm2 per nucleus, possibly driving demand for myonuclear addition to support myofiber expansion. These findings strongly suggest myonuclear addition via SC recruitment may be required to achieve substantial myofiber hypertrophy in humans. Individuals with a greater basal presence of SCs demonstrated, with training, a remarkable ability to expand the SC pool, incorporate new nuclei, and achieve robust growth.
Median Raphe Stimulation Disrupts Hippocampal Theta Via Rapid Inhibition and State-Dependent Phase Reset of Theta-Related Neural Circuitry
Authors: Jackson Jesse , Dickson Clayton T. , Bland Brian H.
Published: April 2008

Evidence has accumulated suggesting that the median raphe (MR) mediates hippocampal theta desynchronization. However, few studies have evaluated theta-related neural circuitry during MR manipulation. In urethane-anesthetized rats, we investigated the effects of MR stimulation on hippocampal field and cell activity using high-frequency (100 Hz), theta burst (TBS), and slow-frequency electrical stimulation (0.5 Hz). We demonstrated that high-frequency stimulation of the MR did not elicit deactivated patterns in the forebrain, but rather elicited low-voltage activity in the neocortex and small-amplitude irregular activity (SIA) in the hippocampus. Both hippocampal phasic theta-on and -off cells were inhibited by high-frequency MR stimulation, although MR stimulation failed to affect cells that had neither state or phase relationships with theta field activity. TBS of the MR-induced theta field activity phase locked to the stimulation. Slow-frequency stimulation elicited a state-dependent reset of theta phase through a short-latency inhibition (5 ms) in phasic theta-on cells. Subpopulations of phasic theta-on cells responded in either oscillatory or nonoscillatory patterns to MR pulses, depending on their intraburst interval. off cells exhibited a state-dependent modulation of cell firing occurring preferentially during nontheta. The magnitude of MR-induced reset varied as a function of the phase of the theta oscillation when the pulse was administered. Therefore high-frequency stimulation of the MR appears to disrupt hippocampal theta through a state-dependent, short-latency inhibition of rhythmic cell populations in the hippocampus functioning to switch theta oscillations to an activated SIA field state.
A Functional Equation Originating from Elliptic Curves
Authors: Park Won-Gil , Bae Jae-Hyeong
Published: April 2008

We obtain the general solution and the stability of the functional
equation
f(x + y + z, u + v + w) + f(x + y − z, u + v + w) + 2f(x, u − w) + 2f(y, v − w) = f(x + y, u + w) + f(x + y, v + w) + f(x + z, u + w) + f(x − z, u + v − w) + f(y + z, v + w) + f(y − z, u + v − w).
The function f(x, y) = x3 + ax + b − y2 having level curves as elliptic curves is a solution of the above functional equation.
On Chung‐Teicher Type Strong Law of Large Numbers for ρ∗‐Mixing Random Variables
Authors: Kuczmaszewska Anna
Published: April 2008

In this paper the classical strong laws of large number of Kolmogorov, Chung, and Teicher for independent random variables were generalized on the case of ρ∗‐mixing sequence. The main result was applied to obtain a Marcinkiewicz SLLN.
On Krasnoselskii's Cone Fixed Point Theorem
Authors: Kwong Man Kam
Published: April 2008

In recent years, the Krasnoselskii fixed point theorem for cone maps and its many generalizations have been successfully applied to establish the existence of multiple solutions in the study of boundary value problems of various types. In the first part of this paper, we revisit the Krasnoselskii theorem, in a more topological perspective, and show that it can be deduced in an elementary way from the classical Brouwer-Schauder theorem. This viewpoint also leads to a topology-theoretic generalization of the theorem. In the second part of the paper, we extend the cone theorem in a different direction using the notion of retraction and show that a stronger form of the often cited Leggett-Williams theorem is a special case of this extension.
Classification Models for Early Detection of Prostate Cancer
Authors: Wichard Joerg D. , Cammann Henning , Stephan Carsten , Tolxdorff Thomas
Published: April 2008

We investigate the performance of different classification models and their ability to recognize prostate cancer in an
early stage. We build ensembles of classification models in order to increase the classification performance. We measure
the performance of our models in an extensive cross‐validation procedure and compare different classification
models. The datasets come from clinical examinations and some of the classification models are already in use to support
the urologists in their clinical work.
De Novo Balanced Translocation t (7;16) (p22.1; p11.2) Associated with Autistic Disorder
Authors: Bayou Nadia , M′rad Ridha , Belhaj Ahlem , Daoud Hussein , Ben Jemaa Lamia , Zemni Ramzi , Briault Sylvain , Helayem M. Bechir , Chaabouni Habiba
Published: April 2008

The high incidence of de novo chromosomal aberrations in a population of persons with autism suggests a causal relationship between certain chromosomal aberrations and the occurrence of isolated idiopathic autism. We report on the clinical and cytogenetic findings in a male patient with autism, no physical abnormalities and a de novo balanced (7;16)(p22.1;p16.2) translocation. G‐banded chromosomes and fluorescent in situ hybridization (FISH) were used to examine the patient′s karyotype as well as his parents′. FISH with specific RP11‐BAC clones mapping near 7p22.1 and 16p11.2 was used to refine the location of the breakpoints. This is, in the best of our knowledge, the first report of an individual with autism and this specific chromosomal aberration.
Active Noise Cancellation for Ventilation Ducts Using a Pair of Loudspeakers by Sampled‐Data ℋ∞ Optimization
Authors: Kobayashi Yasuhide , Fujioka Hisaya
Published: April 2008

We deal with the design of active noise control systems for ventilation ducts with a pair of loud‐speakers based on sampled‐data ℋ∞ optimization, in order to improve our previous study with a single loudspeaker. The resultant controller requires lower computational complexity for the implementation, compared to the standard time‐varying adaptive controllers, since it is time‐invariant and the order is comparable. Moreover, the effect of Swinbanks′ source is automatically recovered by the ℋ∞ optimization. The benefit of the proposed method is also confirmed from experimental results for a real house, where the achieved noise attenuation level is about twice as much as that of the single loudspeaker case.
Optical Filters Utilizing Ion Implanted Bragg Gratings in SOI Waveguides
Authors: Bulk M. P. , Knights A. P. , Jessop P. E. , Waugh P. , Loiacono R. , Mashanovich G. Z. , Reed G. T. , Gwilliam R. M.
Published: April 2008

The refractive index modulation associated with the implantation
of oxygen or silicon into waveguides formed in silicon‐on‐insulator (SOI)
has been investigated to determine the feasibility of producing planar, implantation
induced Bragg grating optical filters. A two‐dimensional coupled mode theory‐based
simulation suggests that relatively short grating lengths, on the order of a thousand microns,
can exhibit sufficient wavelength suppression, of >10 dB, using the implantation technique. Fabricated planar implanted slab‐guided SOI waveguides demonstrated an extinction of −10 dB for TE modes and −6 dB for TM modes for the case of oxygen implantation. Extinctions of −5 dB and −2 dB have been demonstrated with silicon implantation.
Radioiodinated Naphthylalanine Derivatives Targeting Pancreatic Beta Cells in Normal and Nonobese Diabetic Mice
Authors: Amartey John K. , Shi Yufei , Al-Jammaz Ibrahim , Esguerra Celestina , Al-Otaibi Basem , Al-Mohanna Futwan
Published: April 2008

An imaging method capable of using a signal from pancreatic beta cells to determine their mass would be of immense value in monitoring the progression of diabetes as well as response to treatment. Somatostatin receptors (SSTRs) are expressed on beta cells and are a potential target for imaging. The main objective of this study was to investigate whether pancreatic beta cells are a target for radiolabeled naphthylalanine derivatives. The molecules were subjected to in
vitro and ex vivo evaluations. Pancreatic uptake of radioactivity was lower in nonobese diabetic (NOD) mice than normal mice at all time points investigated (P < .05) and correlated with the number of islets in tissue sections of both control and NOD mice. Immunohistochemical and confocal fluorescent microscopic studies showed colocalization of insulin and the conjugate radioligand in the pancreas. The results demonstrated that pancreatic uptake is receptor‐mediated, and that beta cells are the primary target.
Accurate Analysis of Practical 3D Periodic Leaky‐Wave Patch Antennas
Authors: Zunoubi Mohammad R. , Kalhor Hassan A.
Published: April 2008

This paper presents a new analysis method based on the finite integral technique (FIT) of practical three‐dimensional leaky‐wave antennas comprised of a finite number of patches arranged in arrays. Radiation patterns and scattering parameters are calculated and compared with corresponding measured results to demonstrate the adequacy and the accuracy of the proposed method. The technique is then used as an antenna design tool to obtain the desired radiation patterns and beam scanning by selective choice of array elements dimensions, spacing, and substrate parameters.
Peroxisome Proliferator‐Activated Receptor‐γ in Amyotrophic Lateral Sclerosis and Huntington′s Disease
Authors: Kiaei Mahmoud
Published: April 2008

Amyotrophic lateral sclerosis (ALS) is a debilitating and one of the most common adult‐onset neurodegenerative diseases with the prevalence of about 5 per 100 000 individuals. It results in the progressive loss of upper and lower motor neurons and leads to gradual muscle weakening ultimately causing paralysis and death. ALS has an obscure cause and currently no effective treatment exists. In this review, a potentially important pathway is described that can be activated by peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) agonists and has the ability to block the neuropathological damage caused by inflammation in ALS and possibly in other neudegenerative diseases like Huntington′s disease (HD). Neuroinflammation is a common pathological feature in neurodegenerative diseases. Therefore, PPAR‐γ agonists are thought to be neuroprotective in ALS and HD. We and others have tested the neuroprotective effect of pioglitazone (Actos), a PPAR‐γ agonist, in G93A SOD1 transgenic mouse model of ALS and found significant increase in survival of G93A SOD1 mice. These findings suggest that PPAR‐γ may be an important regulator of neuroinflammation and possibly a new target for the development of therapeutic strategies for ALS. The involvement of PPAR‐γ in HD is currently under investigation, one study finds that the treatment with rosiglitazone had no protection in R6/2 transgenic mouse model of HD. PPAR‐γ coactivator‐1α (PGC‐1α) is a transcriptional coactivator that works together with combination of other transcription factors like PPAR‐γ in the regulation of mitochondrial biogenesis. Therefore, PPAR‐γ is a possible target for ALS and HD as it functions as transcription factor that interacts with PGC‐1α. In this review, the role of PPAR‐γ in ALS and HD is discussed based on the current literature and hypotheses.
Biological Monitoring of Hexavalent Chromium and Serum Levels of the Senescence Biomarker Apolipoprotein J/Clusterin in Welders
Authors: Alexopoulos Evangelos C. , Cominos Xenophon , Trougakos Ioannis P. , Lourda Magda , Gonos Efstathios S. , Makropoulos Vassilios
Published: April 2008

Welding fumes contain metals and other toxic substances known or strongly suspected to be related with oxidative stress and premature cellular senescence. Apolipoprotein J/Clusterin (ApoJ/CLU) is a glycoprotein that is differentially regulated in various physiological and disease states including ageing and age‐related diseases. In vitro data showed that exposure of human diploid fibroblasts to hexavalent chromium (Cr(VI)) resulted in premature senescence and significant upregulation of the ApoJ/CLU protein. In this study we analyzed blood and urine samples from shipyard industry welders being exposed to different levels of Cr(VI) over a period of five months in order to assay in vivo the relation of ApoJ/CLU serum levels with Cr(VI). Our findings confirmed the previously reported in vitro data since reduction of Cr levels, after a worksite intervention, associated with lower levels of ApoJ/CLU serum levels. We concluded that the human ApoJ/CLU gene is responsive to the acute in vivo oxidative stress induced by heavy metals such as hexavalent chromium.
Asymmetric Variate Generation via a Parameterless Dual Neural Learning Algorithm
Authors: Fiori Simone
Published: April 2008

In a previous work (S. Fiori, 2006), we proposed a random number generator based on a tunable non-linear neural system, whose learning rule is designed on the basis of a cardinal equation from statistics and whose implementation is based on look-up tables (LUTs). The aim of the present manuscript is to improve the above-mentioned random number generation method by changing the learning principle, while retaining the efficient LUT-based implementation. The new method proposed here proves easier to implement and relaxes some previous limitations.
Peroxisome Proliferator‐Activated Receptor‐ γ Ligands: Potential Pharmacological Agents for Targeting the Angiogenesis Signaling Cascade in Cancer
Authors: Giaginis Costas , Tsantili-Kakoulidou Anna , Theocharis Stamatios
Published: April 2008

Peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) has currently been considered as molecular target for the treatment of human metabolic disorders. Experimental data from in vitro cultures, animal models, and clinical trials have shown that PPAR‐γ ligand activation regulates differentiation and induces cell growth arrest and apoptosis in a variety of cancer types. Tumor angiogenesis constitutes a multifaceted process implicated in complex downstream signaling pathways that triggers tumor growth, invasion, and metastasis. In this aspect, accumulating in vitro and in vivo studies have provided extensive evidence that PPAR‐γ ligands can function as modulators of the angiogenic signaling cascade. In the current review, the crucial role of PPAR‐γ ligands and the underlying mechanisms participating in tumor angiogenesis are summarized. Targeting PPAR‐γ may prove to be a potential therapeutic strategy in combined treatments with conventional chemotherapy; however, special attention should be taken as there is also substantial evidence to support that PPAR‐γ ligands can enhance angiogenic phenotype in tumoral cells.
A Discrete Monetary Economic Growth Model with the MIU Approach
Authors: Zhang Wei-Bin
Published: April 2008

This paper proposes an alternative approach to economic growth with money. The production side is the same as the Solow model, the Ramsey model, and the Tobin model. But we deal with behavior of consumers differently from the traditional approaches. The model is influenced by the money‐in‐the‐utility (MIU) approach in monetary economics. It provides a mechanism of endogenous saving which the Solow model lacks and avoids the assumption of adding up utility over a period of time upon which the Ramsey approach is based.
Use of the Natural Circulation Flow Map for Natural Circulation Systems Evaluation
Authors: Cherubini M. , Giannotti W. , Araneo D. , D'Auria F.
Published: April 2008

The aim of this paper is to collect and resume the work done to build and develop, at the University of Pisa, an engineering tool related to the natural circulation. After a brief description of the different loop flow regimes in single phase and two phase, the derivation of a suitable tool to judge the NC performance in a generic system is presented. Finally, an extensive comparison among the NC performance of various nuclear power plants having different design is done to show a practical application of the NC flow map.