bluuebunny/crossref_metadata_2025 huggingface dataset:
Attenuation of cysteinyl leukotrienes induces human mesenchymal stem cell differentiation
Authors: Akino Kozo , Mineda Takao , Mori Nozomu , Hirano Akiyoshi , Imaizumi Toshifumi , Akita Sadanori
Published: June 2006

Although there are numerous investigations describing bone marrow cells or bone‐marrow derived cells at the site of such injuries as bone fractures, infarction and subsequent ischemic reperfusion injury, or cutaneous wounds, little is know about the factors that affect the cells in those clinical situations. Cysteinyl leukotrienes have been extensively investigated in airway diseases that may eventually lead to lung fibrosis; while the engraftment of mesenchymal stem cells have been shown to reverse bleomycin‐induced lung fibrosis in vivo. Therefore, we elucidated the involvement of cysteinyl leukotrienes in human mesenchymal stem cell proliferation and differentiation. Human mesenchymal stem cells express the cysteinyl leukotriene type 1 receptor. Various doses of pranlukast, which is a specific cysteinyl leukotriene type 1 receptor antagonist, failed to affect the proliferation of cells; however, 10−6 M of pranlukast significantly induced cellular cytoplasmic differentiation by showing microvilli sprouting and the emersion of rough endoplasmic reticulum within a 16‐hour(s) incubation. Additionally, pranlukast‐induced fibronectin protein production by human mesenchymal stem cells. Therefore, attenuation of the cysteinyl leukotriene pathway contributes to human mesenchymal stem cell differentiation and may contribute to modulation of the local injury site.
Optimized delivery of skin keratinocytes by aerosolization and suspension in fibrin tissue adhesive
Authors: Harkin Damien G. , Dawson Rebecca A. , Upton Zee
Published: June 2006

Aerosolized suspensions of keratinocytes provide a potential therapy for wounds, but the effects of aerosolization on cell viability remain unclear. Likewise, little is known of the resulting cell distribution pattern and how this compares to the density required for epithelialization. The potential benefits of cospraying cells in the presence of fibrin adhesive are equally uncertain. Thus, in the present study we have optimized conditions for the aerosolization of cultured keratinocytes using a device (Tissomat™) that supports the option for coapplication with fibrin (Tisseel™). Cell viability was unaffected when sprayed at 10 psi, but a significant reduction in metabolic activity, as determined by the methylthiazoyldiphenol‐tetrazolium assay, was observed at higher pressure. Bursts of 0.2 mL cell suspension (1.5 × 106/mL) delivered from a height of 10 cm was sufficient to epithelialize an area of 10–15 cm2 within 7 days in vitro. Confluent areas corresponded to those with a density of 5,000–10,000 cells/cm2 at 24 hours. Optimal cell growth in Tisseel™ was achieved through dilution of fibrinogen (1–3 mg/mL) and thrombin (2–5 IU/mL). This optimized formulation eliminated fluid run‐off postspraying and stimulated a twofold increase in cellular response. Therefore, our in vitro data supports the theory that aerosolized suspensions of keratinocytes in fibrin will benefit healing.
Idiopathic pericarditis in dogs: no evidence for an immune‐mediated aetiology
Authors: Martin M. W. S. , Green M. J. , Stafford Johnson M. J. , Day M. J.
Published: June 2006

Objectives: To ascertain whether specific immunological changes are associated with canine pericardial effusion due to idiopathic pericarditis.

Methods: In this prospective study, serum antinuclear antibody and serum and pericardial fluid immunoglobulin (Ig) G, Ig M and Ig A concentrations were measured in dogs with pericardial effusion due to idiopathic pericarditis or pericardial neoplasia. The secretory index relative to albumin concentration was calculated in order to distinguish between Ig actively secreted into the pericardial fluid and that derived from the blood accumulating within the pericardial sac. Statistical analysis was performed comparing the results obtained between the two groups of dogs.

Results: Only three dogs were antinuclear antibody positive; two of these dogs had idiopathic pericarditis and one had neoplasia. Mean serum Ig M and Ig A concentrations were lower than the reference values in both groups, and the secretory indices for Ig M and Ig A were greater than 1·0. However, there was no significant difference with respect to any Ig measurement between the two groups of dogs (P>0·1).

Clinical Significance: The results of the present study do not support the hypothesis that canine idiopathic pericarditis has a significant ‘immune‐mediated’ aetiology or immunological features that distinguish it from the pericardial changes associated with local neoplastic disease.
Ureteral fibroepithelial polyp in a dog
Authors: Farrell M. , Philbey A. W. , Ramsey I.
Published: June 2006

Haematuria in a dog occurred secondarily to a unilateral ureteral fibroepithelial polyp. The diagnostic techniques, gross pathology and histopathological findings of this unusual benign tumour are reported. Complete resolution of clinical signs occurred following ureteronephrectomy.
Resolution of diabetes mellitus but not acromegaly in a cat with a pituitary macroadenoma treated with hypofractionated radiation
Authors: Littler R. M. , Polton G. A. , Brearley M. J.
Published: June 2006

The use of insulin‐like growth factor 1 assays in the diagnosis and subsequent monitoring after radiotherapy of an acromegalic cat with a secretory pituitary adenoma and secondary insulin‐resistant diabetes mellitus is described. Diabetes resolved, and exogenous insulin was no longer required for the maintenance of normoglycaemia 10 months after completion of a course of hypofractionated radiotherapy. However, insulin‐like growth factor 1 remained elevated, and the cat’s size and appetite continued to increase. It is suggested that radiotherapy may decrease growth hormone concentration to a level such that diabetogenic effects are no longer evident but not to a level required to decrease insulin‐like growth factor 1 secretion.
Surgical management of a double‐chambered right ventricle and chylothorax in a Labrador retriever
Authors: Tanaka R. , Shimizu M. , Hirao H. , Kobayashi M. , Nagashima Y. , Machida N. , Yamane Y.
Published: June 2006

A 22‐month‐old, male Labrador retriever was presented with anorexia, dyspnoea, and fainting. The dog was diagnosed with a double‐chambered right ventricle and tricuspid valve dysplasia using echocardiography and cardiac catheterisation. A marked bilateral pleural effusion was also present and chemical analysis of the fluid confirmed the diagnosis of chylothorax. Using echocardiography, a pressure gradient of 87·1 mmHg was found between the proximal and distal chambers of the double‐chambered right ventricle. Initiation of cardiopulmonary bypass allowed the anomalous muscle bundle that divided the right ventricle into two chambers to be resected via a right ventriculotomy. The fainting completely resolved postoperatively, and this treatment seemed quite effective in the reduction of pressure overload ascribable to ejection disturbance. Because the tricuspid dysplasia was not corrected in the first operation, the postoperative chyle effusion was reduced but did not cease. A combination of thoracic duct ligation and passive pleuroperitoneal shunting was effective in the resolution of the chyle effusion.
Panniculitis, polyarthritis and osteomyelitis associated with pancreatic neoplasia in two dogs
Authors: Gear R. N. A. , Bacon N. J. , Langley‐Hobbs S. , Watson P. J. , Woodger N. , Herrtage M. E.
Published: June 2006

A 12‐year‐old crossbred dog (case 1) and a 12‐year‐old Shetland sheepdog (case 2) were presented with a history of lameness and distal limb swelling. Physical examination revealed joint effusions and asymmetrical swellings of the extremities. In case 1, a diagnosis of arthritis and cellulitis was made on fine‐needle aspiration biopsy of the synovium and subcutis. In case 2, bone biopsies and synovial aspirates diagnosed osteomyelitis and arthritis. A diagnosis of pancreatic disease was made on the findings of marked elevations of serum lipase concentrations and ultrasonographic identification of pancreatic masses in both cases. Both the cases were non‐responsive to symptomatic management and were subsequently euthanased. Postmortem examination confirmed the diagnosis of panniculitis, arthritis and osteomyelitis in both cases. A pancreatic exocrine adenoma was identified in case 1 and a pancreatic adenocarcinoma with widespread metastases in case 2. To the authors' knowledge the association of panniculitis, polyarthritis and osteomyelitis with pancreatic disorders has not been reported previously in canine clinical cases.
Competing processes of clastic deposition and compartmentalized inversion in an actively evolving transpressional basin, western Mongolia
Authors: Howard J.P. , Cunningham W.D. , Davies S.J.
Published: June 2006

The Dariv Basin is an actively evolving intracontinental transpressional basin located on the eastern flank of the Mongolian Altai. The basin occupies a complex tectonic position between a restraining bend, a thrusted basement block, and two major conjugate strike-slip fault systems. Structures and sedimentary strata exposed within the Dariv Basin suggest a Mesozoic and Cenozoic two-stage evolution. Jurassic–Cretaceous strata fine upward and record alluvial fan, fluvial and lacustrine depositional environments. The distribution of Mesozoic sedimentary rocks and the presence of a suspected Jurassic normal fault array suggest that the Dariv Basin initially formed as an extensional basin. Following Palaeogene tectonic quiescence, Oligocene–Recent basin fill is dominated by alluvial fan sediments derived from basin-flanking ranges. The modern basin is deforming by thrusting, normal fault inversion and folding along discrete belts expressed as intrabasinal ridges and domes. These belts define a rhomboid of active deformation that compartmentalizes the basin. Sediments derived from these discrete deforming belts and from basin flanking ranges continue to accumulate in the basin centre. Thus, modern fans contain reworked older basin fill and competing processes of sedimentation, deformation, erosion and resedimentation can be observed. The Dariv Basin is an excellent example of a transpressional piggyback basin in the early stages of basin inversion and destruction.
Tectonic implications of the granite dyke swarm in the Ronda peridotites (Betic Cordilleras, Southern Spain)
Authors: Cuevas J. , Esteban J.J. , Tubía J.M.
Published: June 2006

This paper deals with the origin and structural relationships of the leucocratic dykes that intruded the Ronda peridotites. Plagiogranites are frequent in ophiolitic sequences, but similar Si-rich melts are scarce in orogenic lherzolites. The Ronda peridotites could be an excellent target in which to look for Si-rich melts of mantle origin, as they form the largest mass of orogenic lherzolites in the world and contain many granite dykes. However, petrographic and geochemical data provide evidence that the dykes come from felsic magmas originated from partial melting of the continental crust. Structural studies of the deformed and undeformed dykes reveal that they are non-Andersonian dykes that exploited pre-existing fractures. Undeformed dykes display N15°E strike, whereas the deformed ones show N50°E or N100°E trends and sinistral and dextral shear senses, respectively. These structural data point to reactivation of pre-existing fractures either as tensional cracks (undeformed dykes) or transtensional shear zones (deformed dykes) during the ENE-directed thrusting of the Ronda peridotites. Consequently, the dominant N15°E trend of the undeformed dykes can be used to infer an ENE-thrusting direction for the buried basal shear zone of the Ronda peridotites.
Extensional detachment faulting on the Tyrrhenian margin of the southern Apennines contractional belt (Italy)
Authors: Casciello E. , Cesarano M. , Pappone G.
Published: June 2006

The tectonic evolution of the Campania margin during the late Pliocene–Pleistocene is characterized by extensional deformation coeval with the opening of the Marsili oceanic basin. The initial stages of stretching are represented in the analysed area by the development of low-angle normal faults that extended the belt in the same direction as the direction of spreading recognized for the oceanic basin. Detachment faulting was accompanied by the onset of magmatic activity and by major uplifts that resulted in the accumulation of thick conglomerate successions in the half-grabens that developed in the upper plate of the extensional detachment. Deformation continued during the Mid-Pleistocene with the formation of strike-slip and normal faults trending almost parallel to the spreading direction of the Marsili basin. These faults dissected the extensional detachment and promoted counter-clockwise block rotations about vertical axes, which accommodated the ESE-directed stretching of the Marsili basin and the consequent sinistral shear imposed on the southern Apennine chain. The development of a regional detachment fault along the Tyrrhenian margin of Campania explains the complex patterns of subsidence and uplift that characterize this area during the Pleistocene and fits well within the regional geodynamic framework of the southern Tyrrhenian Sea.
The tourmaline-bearing granite pluton of Bodmin (Cornwall, UK): magnetic fabric study and regional inference
Authors: Bouchez Jean Luc , Nguema Thierry Mintsa Mi , Esteban Lionel , Siqueira Roberto , Scrivener Richard
Published: June 2006

The magnetic fabrics and microstructures of the Variscan granite pluton of Bodmin (Cornwall) have been studied. Its low susceptibility magnitude, consistent with its lack of magnetite, comes from biotite and tourmaline. As the magneto-crystalline behaviour of tourmaline is ‘inverse’ compared with that of the phyllosilicates, the magnetic fabric was remeasured after heating the specimens to enhance the biotite magnetic signal by the growth of mimetic magnetite. The roughly similar magnetic fabrics before and after heating demonstrate that the effect of tourmaline is not important as long as the tourmaline content does not exceed that of the phyllosilicates. Regionally, this study reveals a well-defined NNW trend of the magnetic lineations with opposite plunges on each side of a separation line crossing the pluton centre. This pattern, very similar to that documented in the nearby Carnmenellis pluton, is ascribed to unroofing during emplacement. It agrees with the late to post-magmatic NW stretch that characterizes the Devonian to Carboniferous formations located to the north of this region, the thrust-and-fold structure of which is attributed to southward compression. We conclude that syntectonic emplacement may have characterized the whole Cornubian batholith at the very end of the Variscan orogeny in Cornwall.
Timing of early angiosperm radiation: recalibrating the classical succession
Authors: Hochuli P.A. , Heimhofer U. , Weissert H.
Published: June 2006

New stratigraphically controlled pollen data from the late Early Cretaceous of Portugal allow a recalibration of the classical continental succession of the Potomac Group (USA), which has long been used to demonstrate the gradual morphological changes of angiosperm leaves and pollen. The Portuguese record represents the best dated succession of angiosperm pollen assemblages of the interval between the late Barremian and the mid-Albian. Comparison of the angiosperm pollen record of the Potomac Group with the pollen assemblages from Portugal and with other independently dated records indicates that the distinct differences in the angiosperm pollen assemblages between the three formations of this group (the Patuxent Formation, Arundel Clay Formation and Patapsco Formation) are related to discontinuities. Our revised age model for the Potomac Group implies a major discontinuity between the Arundel Clay (of early Albian age), and the Patapsco Formation (of mid-Albian–early Cenomanian age). The Portuguese record reveals a so far undocumented radiation phase of angiosperms within the early Aptian to mid-Albian in which monocolpate angiosperm pollen of monocot and/or magnoliid affinity appear as a highly diversified group. These new findings imply that the onset of the radiation of monocots–magnoliids preceded the radiation of eudicots by at least 10 Ma.
First results from the CROP-11 deep seismic profile, central Apennines, Italy: evidence of mid-crustal folding
Authors: Billi A. , Tiberti M.M. , Cavinato G.P. , Cosentino D. , Di Luzio E. , Keller J.V.A. , Kluth C. , Orlando L. , Parotto M. , Praturlon A. , Romanelli M. , Storti F. , Wardell N.
Published: June 2006

The CROP-11 deep seismic profile across the central Apennines, Italy, reveals a previously unknown, mid-crustal antiform here interpreted as a fault-bend fold-like structure. The seismic facies and gravity signature suggest that this structure consists of low-grade metamorphic rocks. Geomorphological, stratigraphic and tectonic evidence in the overlying shallow thrusts suggests that this structure developed in early to mid-Messinian time and grew out of sequence in late Messinian–Pliocene time. The out-of-sequence growth may reflect a taper subcriticality stage of the Apenninic thrust wedge, which induced renewed contraction in the rear.
Zircon age constraints on sediment provenance in the Caspian region
Authors: Allen Mark B. , Morton Andy C. , Fanning C. Mark , Ismail-Zadeh Arif J. , Kroonenberg Salomon B.
Published: June 2006

Sensitive high-resolution ion microprobe (SHRIMP) U–Pb ages for detrital zircons from the Caspian region reveal the age ranges of basement terrains that supplied the sediment. One sample from the modern Volga river has groupings at
c
. 340–370 Ma,
c
. 900–1300 Ma and
c
. 1450–1800 Ma, with a small number of older zircons. This is consistent with derivation from the Precambrian basement of the East European Craton, and Palaeozoic arcs in the Urals. Mid- and Late Proterozoic components may be derived from beyond the present Volga drainage basin, such as the Sveconorwegian orogen. A Bajocian sandstone from the Greater Caucasus has 73% zircons that post-date 350 Ma. Ages cluster at
c
. 165–185 Ma,
c
. 220–260 Ma,
c
. 280–360 Ma and
c
. 440–460 Ma. This pattern suggests derivation from Palaeozoic basement of the Greater Caucasus itself and/or the Scythian Platform, and igneous rocks generated at a Jurassic arc in the Lesser Caucasus. Four samples from the Lower Pliocene Productive Series of the South Caspian Basin have common Phanerozoic grains, and groups between
c
. 900–1300 Ma and 1500–2000 Ma. Each sample contains zircons dated to
c
. 2700 Ma. The overall age patterns in the Productive Series samples suggest a combination of East European Craton and Greater Caucasus source components.
A possible earthquake-triggered mega-boulder slide in a Chilean Mio-Pliocene marine sequence: evidence for rapid uplift and bonebed genesis
Authors: Walsh S.A. , Martill D.M.
Published: June 2006

The type area of the Bahía Inglesa Formation (north–central Chile) is structurally complex as a result of active margin subduction at the Peru–Chile Trench. Inliers of subaerially exposed Mesozoic igneous basement are unconformably overlain by a mid-Miocene to late Pliocene marine siliciclastic sequence, which has become known for its abundance of fossil vertebrates found concentrated in a phosphatite on an omission surface. Mega-boulders derived from one of the largest inliers occur exclusively within this bonebed, which appears to have formed after major localized uplift caused removal of a significant thickness of unconsolidated sediment. The mega-boulders were probably dislodged by a high-magnitude earthquake event that accompanied tilting of the sea floor, and their emplacement was an integral part of the processes involved in genesis of the bonebed.
A discussion of possible heat sources during nappe stacking: the origin of Barrovian metamorphism within the Caledonian thrust sheets of NW Scotland
Authors: JOHNSON M.R.W. , STRACHAN R.A.
Published: June 2006

Geochronological data indicate that the Caledonian thrust sheets of NW Scotland were assembled in
<
18 Ma, yet regional Barrovian metamorphism to amphibolite facies and local melting occurred syn-thrusting. From theoretical studies, it is clear that there is insufficient time to generate the high metamorphic temperatures during the thrusting event. We suggest that a plausible explanation for the heat source is that it resulted from a 20–25 Ma period of crustal heating in a back-arc setting between the Grampian and Scandian orogenic events. Most of the orogenic heat therefore came from the pre-existing back-arc rather than the orogenic process itself.
The Molecular Diversity of Glycosaminoglycans Shapes Animal Development
Authors: Bülow Hannes E. , Hobert Oliver
Published: June 2006

Proteoglycans (PGs), molecules in which glycosaminoglycans (GAGs) are covalently linked to a protein core, are components of the extracellular matrix of all multicellular organisms. Sugar moieties in GAGs are often extensively modified, which make these molecules enormously complex. We discuss here the role of PGs during animal development, emphasizing the in vivo significance of sugar modifications. We explore a model in which the modification patterns of GAG chains may provide a specific code that contributes to the correct development of a multicellular organism.
Trafficking of dietary fat in obesity-prone and obesity-resistant rats
Authors: Jackman Matthew R. , Kramer Robert E. , MacLean Paul S. , Bessesen Daniel H.
Published: June 2006

The trafficking of dietary fat was assessed in obesity-prone (OP) and obesity-resistant (OR) male and female rats. Test meals containing [1-14C]palmitate were delivered through gastric feeding tubes while rats consumed a high-carbohydrate diet (HCD) or after 5 days of a high-fat diet (HFD). Over the subsequent 24 h, the appearance of14C was followed in the GI tract, skeletal muscles (SM), liver, adipose tissues (AT), and expired CO2. There was no difference in the production of14CO2between OP and OR rats consuming a HCD. However, after 5 days on HFD, OR rats produced significantly more14CO2after the test meal than OP rats ( P < 0.001 females, P = 0.03 males). The differential oxidation of dietary fat between OP and OR rats on HFD was not due to differences in absorption but rather was associated with preferential disposition of tracer to AT in OP rats. Measurements of lipoprotein lipase in part explained increased tracer uptake by AT in OP rats but were not consistent with increased SM tracer uptake in OR rats. Surprisingly, female rats oxidized more tracer than male rats irrespective of phenotype or diet. These results are consistent with the notion that differences in the partitioning of dietary fat between storage in AT and oxidation in SM and liver that develop shortly after the introduction of a HFD may in part underlie the differential tendency for OR and OP rats to gain weight on this diet.
Sex-specific differences in leg fat uptake are revealed with a high-fat meal
Authors: Votruba Susanne B. , Jensen Michael D.
Published: June 2006

The mechanism(s) by which sex specific differences in regional body fat distribution develop are not known. We assessed the effects of a high-fat (HF) meal on fatty acid oxidation and uptake into regional fat depots using isotopic tracers and adipose biopsies. Thirty men (BMI 23.6 ± 0.3 kg/m2) and 29 women (BMI 22.4 ± 0.3 kg/m2) received a meal containing [3H]triolein. Twelve of the men and 13 of the women received an additional 80 g of triolein in the meal (HF) and the remainder received a normal-fat (NF) meal. Adipose tissue lipoprotein lipase (LPL) activity was measured in the fed and fasted state. After 24 h, meal fatty acid uptake into subcutaneous adipose tissue was assessed. The efficiency of meal fat uptake into upper body subcutaneous fat was similar in both sexes, but women had a greater leg fat uptake, especially in response to a HF meal ( P < 0.0001). A correlation between fed-state LPL activity and meal fat uptake was found in both upper and lower body fat ( P < 0.0001, r = 0.69). These studies show that, in times of net fat storage, women preferentially increase uptake in leg adipose tissue, and this is likely mediated by fed-state LPL activity.
Derangements in mitochondrial metabolism in intercostal and leg muscle of critically ill patients with sepsis-induced multiple organ failure
Authors: Fredriksson Katarina , Hammarqvist Folke , Strigård Karin , Hultenby Kjell , Ljungqvist Olle , Wernerman Jan , Rooyackers Olav
Published: June 2006

Critically ill patients treated for multiple organ failure often develop muscle dysfunction. Here we test the hypothesis that mitochondrial and energy metabolism are deranged in leg and intercostal muscle of critically ill patients with sepsis-induced multiple organ failure. Ten critically ill patients suffering from sepsis-induced multiple organ failure and requiring mechanical ventilation were included in the study. A group ( n = 10) of metabolically healthy age- and sex-matched patients undergoing elective surgery were used as controls. Muscle biopsies were obtained from the vastus lateralis (leg) and intercostal muscle. The activities of citrate synthase and mitochondrial respiratory chain complexes I and IV and concentrations of ATP, creatine phosphate, and lactate were analyzed. Morphological evaluation of mitochondria was performed by electron microscopy. Activities of citrate synthase and complex I were 53 and 60% lower, respectively, in intercostal muscle of the patients but not in leg muscle compared with controls. The activity of complex IV was 30% lower in leg muscle but not in intercostal muscle. Concentrations of ATP and creatine phosphate were, respectively, 40 and 34% lower, and lactate concentrations were 43% higher in leg muscle but not in intercostal muscle. We conclude that both leg and intercostal muscle show a twofold decrease in mitochondrial content in intensive care unit patients with multiple organ failure, which is associated with lower concentrations of energy-rich phosphates and an increased anaerobic energy production in leg muscle but not in intercostal muscle.
Hexose transporter mRNAs forGLUT4,GLUT5, andGLUT12predominate in human muscle
Authors: Stuart Charles A. , Yin Deling , Howell Mary E. A. , Dykes Rhesa J. , Laffan John J. , Ferrando Arny A.
Published: June 2006

In the past few years, 8 additional members of the facilitative hexose transporter family have been identified, giving a total of 14 members of the SLC2A family of membrane-bound hexose transporters. To determine which of the new hexose transporters were expressed in muscle, mRNA concentrations of 11 glucose transporters (GLUTs) were quantified and compared. RNA from muscle from 10 normal volunteers was subjected to RT-PCR. Primers were designed that amplified 78- to 241-base fragments, and cDNA standards were cloned for GLUT1, GLUT2, GLUT3, GLUT4, GLUT5, GLUT6, GLUT8, GLUT9, GLUT10, GLUT11, GLUT12, and GAPDH. Seven of these eleven hexose transporters were detectable in normal human muscle. The rank order was GLUT4, GLUT5, GLUT12, GLUT8, GLUT11, GLUT3, and GLUT1, with corresponding concentrations of 404 ± 49, 131 ± 14, 33 ± 4, 5.5 ± 0.5, 4.1 ± 0.4, 1.2 ± .0.1, and 0.9 ± 0.2 copies/ng RNA (means ± SE), respectively, for the 10 subjects. Concentrations of mRNA for GLUT4, GLUT5, and GLUT12 were much higher than those for the remainder of the GLUTs and together accounted for 98% of the total GLUT isoform mRNA. Immunoblots of muscle homogenates verified that the respective proteins for GLUT4, GLUT5, and GLUT12 were present in normal human muscle. Immunofluorescent studies demonstrated that GLUT4 and GLUT12 were predominantly expressed in type I oxidative fibers; however, GLUT5 was expressed predominantly in type II (white) fibers.
Insulin and IGF-I action on insulin receptors, IGF-I receptors, and hybrid insulin/IGF-I receptors in vascular smooth muscle cells
Authors: Johansson Git S. , Arnqvist Hans J.
Published: June 2006

Insulin and insulin-like growth factor I (IGF-I) are known to affect cardiovascular disease. We have investigated ligand binding and the dose-response relationship for insulin and IGF-I on vascular smooth muscle cells (VSMCs) at the receptor level. VSMCs from rat thoracic aorta were serum starved, stimulated with IGF-I or insulin, lysed, immunoprecipitated, and analyzed by Western blot. d-[U-14C]Glucose accumulation and [6-3H]thymidine incorporation into DNA were also measured. Specific binding of both insulin and IGF-I was demonstrated, being higher for IGF-I. Both IGF-I receptor (IGF-IR) and insulin receptor (IR) β-subunits were detected and coprecipitated after immunoprecipitation (IP) against either of the two. No coprecipitation was found after reduction of disulphide bonds with dithiotreitol before IP. After stimulation with 10−10–10−9M IGF-I, IP of the IGF-IR, or IR β-subunit and immunoblot with anti-phosphotyrosine antibody, we found two distinct bands indicating phosphorylation of both the IGF-IR and the IR β-subunit. Stimulation with 10−10–10−9M insulin and IP against the IGF-IR did not show phosphorylation of either β-subunit, whereas after IP of the IR we found phosphorylation of the IR β-subunit. [14C]Glucose accumulation and [3H]thymidine incorporation were elevated in cells stimulated with IGF-I at 10−10–10−7M, reaching maximum by 10−9M. Insulin stimulation showed measurable effects only at supraphysiological concentrations, 10−8–10−7M. In conclusion, coprecipitation of both the IGF-IR and the IR β-subunit indicates the presence of hybrid insulin/IGF-I receptors in VSMC. At a physiological concentration, insulin activates the IR but does not affect either glucose metabolism or DNA synthesis, whereas IGF-I both activates the receptor and elicits biological effect.
Combination therapy with acipimox enhances the effect of growth hormone treatment on linear body growth in the normal and small-for-gestational-age rat
Authors: Vickers M. H. , Hofman P. L. , Gluckman P. D. , Lobie P. E. , Cutfield W. S.
Published: June 2006

Growth hormone (GH) therapy is often associated with adverse side effects, including impaired insulin sensitivity. GH treatment of children with idiopathic short stature does not lead to an optimized final adult height. It has been demonstrated that FFA reduction induced by pharmacological antilipolysis can stimulate GH secretion per se in both normal subjects and those with GH deficiency. However, to date, no investigation has been undertaken to establish efficacy of combination treatment with GH and FFA regulators on linear body growth. Using a model of maternal undernutrition in the rat to induce growth-restricted offspring, we investigated the hypothesis that combination treatment with GH and FFA regulators can enhance linear body growth above that of GH alone. At postnatal day 28, male offspring of normally nourished mothers (controls) and offspring born with low birth weight [small for gestational age (SGA)] were treated with saline, GH, or GH (5 mg·kg−1·day−1) in combination with acipimox (GH + acipimox, 20 mg·kg−1·day−1) or fenofibrate (GH + fenofibrate, 30 mg·kg−1·day−1) for 40 days. GH plus acipimox treatment significantly enhanced linear body growth in the control and SGA animals above that of GH, as quantified by tibial and total body length. Treatment with GH significantly increased fasting plasma insulin, insulin-to-glucose ratio, and plasma volumes in control and SGA animals but was not significantly different between saline and GH-plus-acipimox-treated animals. GH-induced lipolysis was blocked by GH plus acipimox treatment in both control and SGA animals, concomitant with a significant reduction in fasting plasma FFA and insulin concentrations. This is the first study to show that GH plus acipimox combination therapy, via pharmacological blocking of lipolysis during GH exposure, can significantly enhance the efficacy of GH in linear growth promotion and ameliorate unwanted metabolic side effects.
Sustained renal interstitial macrophage infiltration following chronic angiotensin II infusions
Authors: Ozawa Yuri , Kobori Hiroyuki , Suzaki Yuki , Navar L. Gabriel
Published: June 2006

Chronic angiotensin (ANG) II infusions into rats lead to augmented intrarenal levels of ANG II and inflammatory factors, impaired renal function, and progressive hypertension. Residual effects persist after cessation of ANG II infusions, as manifested by a hypertensive response to high-salt intake. This study was performed to determine the residual cytokines and chemokines following the cessation of ANG II infusion. Male Sprague-Dawley rats, maintained on a normal diet, received either a sham operation or continuous ANG II infusion (120 ng/min) subcutaneously via minipumps. The ANG II-infused rats were further subdivided into three subgroups. Minipumps were removed on day 12 with subsequent harvesting of kidneys at 0, 3, and 6 days after cessation of ANG II infusion. After 12 days of ANG II infusion, systolic blood pressure, interstitial fibrosis, preglomerular hypertrophy, and interstitial macrophage infiltration were significantly enhanced compared with the shams. By 3 days following the cessation of ANG II infusion, systolic blood pressure was normalized; however, interstitial fibrosis and preglomerular hypertrophy were still present. Furthermore, increased interstitial macrophage infiltration was still present 6 days after cessation of ANG II infusion. Importantly, augmented mRNA levels of monocyte chemotactic protein (MCP)-1 (1.55 ± 0.15 vs. 1.00 ± 0.13, relative ratio) and transforming growth factor (TGF)-β1(1.52 ± 0.16 vs. 1.00 ± 0.08) persisted 6 days after the withdrawal of ANG II infusion (1.60 ± 0.20 for MCP-1 and 1.43 ± 0.17 for TGF-β1). Thus, the ANG II-induced activation of MCP-1 and TGF-β1is sustained and may account for the persistent effect of chronic ANG II infusions on interstitial macrophage infiltration, suggesting a possible mechanism for the development of salt sensitivity in ANG II-dependent hypertension.
Silencing and overexpression of the γ-subunit of Na-K-ATPase directly affect survival of IMCD3 cells in response to hypertonic stress
Authors: Capasso Juan M. , Rivard Christopher J. , Berl Tomas
Published: June 2006

The γ-subunit of Na-K-ATPase is robustly expressed in inner medullary collecting duct (IMCD)3 cells either acutely challenged or adapted to hypertonicity but not under isotonic conditions. Circumstantial evidence suggests that this protein may be important for the survival of renal cells in a hypertonic environment. However, no direct proof for such a contention has been forthcoming. The complete mRNA sequences of either γ-subunit isoforms were spliced into an expression vector and transfected into IMCD3 cells. Multiple clones stably expressed γ-subunit protein under isotonic conditions. Clones expressing the γbisoform showed enhanced survival at lethal acute hypertonicity compared with either γaisoform or empty vector (control) expressing clones. We also evaluated the loss of γ-subunit expression on the survival of IMCD3 cells exposed to hypertonicity employing silencing RNA techniques. Multiple stable γ-subunit-specific siRNA clones were obtained and exposed to sublethal hypertonicity. Under these conditions, both the level of γ mRNA and protein was essentially undetectable. The impact of silencing γ-subunit expression resulted in a 70% reduction at 48 h ( P < 0.01) in cell survival compared with empty vector (control) clones. γ siRNA clones showed a 45% decrease in myo-inositol uptake compared with controls after an 18-h exposure to sublethal hypertonicity. Taken together, these data demonstrate a direct and critical role of the γ-subunit on IMCD3 cell survival and/or adaptation in response to ionic hypertonic stress.
Vascular endothelial growth factor administration does not improve microvascular disease in the salt-dependent phase of post-angiotensin II hypertension
Authors: Long David A. , Mu Wei , Price Karen L. , Roncal Carlos , Schreiner George F. , Woolf Adrian S. , Johnson Richard J.
Published: June 2006

Renal microvascular injury and tubulointerstitial inflammation may provide a potential mechanism for the development of salt-sensitive hypertension. Therefore, we hypothesized that vascular endothelial growth factor (VEGF) administration would prevent the development of salt-sensitive hypertension induced by ANG II. Infusion of ANG II in rats for 2 wk led to an elevation in blood pressure and an increase in blood urea nitrogen. Prominent tubular injury, focal areas of peritubular capillary loss accompanied by a decrease in urinary nitrites, thickening of the afferent arteriole, and an elevation in systemic and renal VEGF protein levels also occurred. In separate studies, animals were infused with ANG II and then placed on a low-salt diet for 1 wk. At this point, the animals were paired on the basis of weight and blood pressure and treated with either VEGF121or vehicle subcutaneously for 8 wk while being fed a high-salt diet. During the treatment period, a spontaneous improvement in many parameters, including both renal function and healing of the peritubular capillaries, occurred to the same degree in both vehicle- and VEGF121-treated rats. VEGF121significantly reduced blood pressure and accelerated the recovery of tubular injury. In contrast, vehicle-treated rats demonstrated a persistent increase in afferent arteriolar media-to-lumen ratio, which was further enhanced in rats treated with VEGF121. Therefore, VEGF therapy has only limited benefits on the healing of renal lesions in the salt-dependent phase of post-ANG II-mediated hypertension.
Two splice variants of claudin-10 in the kidney create paracellular pores with different ion selectivities
Authors: Van Itallie Christina M. , Rogan Sarah , Yu Alan , Vidal Lucia Seminario , Holmes Jennifer , Anderson James M.
Published: June 2006

Members of the large claudin family of tight junction (TJ) proteins create the differences in paracellular conductance and charge selectivity observed among different epithelia. Previous studies demonstrated that ionic charge selectivity is influenced by acidic or basic amino acids on the first extracellular domain of claudins. We noted two alternatively spliced variants of claudin-10 in the database, 10a and 10b, which are predicted to encode two different first extracellular domains and asked whether this might be a novel mechanism to generate two different permselectivities from a single gene. Using quantitative PCR, we found that claudin-10b is widely expressed among tissues including the kidney; however, claudin-10a is unique to the kidney. Using a nondiscriminating antibody, we found that claudin-10 (a plus b) is expressed in most segments of the nephron. In situ hybridization, however, showed that mRNA for 10a is concentrated in the cortex, and mRNA for 10b is more highly expressed in the medulla. Expression in Madin-Darby canine kidney (MDCK) II and LLC-PK1cells reveals that both variants form low-resistance pores, and that claudin-10b is more selective for cations than claudin-10a. Charge-reversing mutations of cationic residues on 10a reveal positions that contribute to its anion selectivity. We conclude that alternative splicing of claudin-10 generates unique permselectivities and might contribute to the variable paracellular transport observed along the nephron.
Operant Conditioning of Reciprocal Inhibition in Rat Soleus Muscle
Authors: Chen Xiang Yang , Chen Lu , Chen Yi , Wolpaw Jonathan R.
Published: June 2006

Operant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex (SSR), induces activity-dependent plasticity in the spinal cord and might be used to improve locomotion after spinal cord injury. To further assess the potential clinical significance of spinal reflex conditioning, this study asks whether another well-defined spinal reflex pathway, the disynaptic pathway underlying reciprocal inhibition (RI), can also be operantly conditioned. Sprague-Dawley rats were implanted with electromyographic (EMG) electrodes in right soleus (SOL) and tibialis anterior (TA) muscles and a stimulating cuff on the common peroneal (CP) nerve. When background EMG in both muscles remained in defined ranges, CP stimulation elicited the TA H-reflex and SOL RI. After collection of control data for 20 days, each rat was exposed for 50 days to up-conditioning (RIup mode) or down-conditioning (RIdown mode) in which food reward occurred if SOL RI evoked by CP stimulation was more (RIup mode) or less (RIdown mode) than a criterion. TA and SOL background EMG and TA M response remained stable. In every rat, RI conditioning was successful (i.e., change ≥20% in the correct direction). In the RIup rats, final SOL RI averaged 171± 28% (mean ± SE) of control, and final TA H-reflex averaged 114 ± 14%. In the RIdown rats, final SOL RI averaged 37 ± 13% of control, and final TA H-reflex averaged 60 ± 18%. Final SOL RI and TA H-reflex sizes were significantly correlated. Thus like the SSR and the H-reflex, RI can be operantly conditioned; and conditioning one reflex can affect another reflex as well.
Kainate Receptor–Mediated Inhibition of Glutamate Release Involves Protein Kinase A in the Mouse Hippocampus
Authors: Negrete-Díaz José V. , Sihra Talvinder S. , Delgado-García José M. , Rodríguez-Moreno Antonio
Published: June 2006

The mechanisms involved in the inhibition of glutamate release mediated by the activation of presynaptic kainate receptors (KARs) at the hippocampal mossy fiber–CA3 synapse are not well understood. We have observed a long-lasting inhibition of CA3 evoked excitatory postsynaptic currents (eEPSCs) after a brief application of kainate (KA) at concentrations ranging from 0.3 to 10 μM. The inhibition outlasted the change in holding current caused by the activation of ionotropic KARs in CA3 pyramidal cells, indicating that this action is not contingent on the opening of the receptor channels. The inhibition of the eEPSCs by KA was prevented by G protein and protein kinase A (PKA) inhibitors and was enhanced after stimulation of the adenylyl cyclase (AC) with forskolin. We conclude that KARs present at mossy fiber terminals mediate the inhibition of glutamate release through a metabotropic mechanism that involves the activation of an AC-second messenger cAMP-PKA signaling cascade.
Quest for arthritis-causative genetic factors in the rat
Authors: Joe Bina
Published: June 2006

Experimental rat models of arthritis are extensively studied with a view to understand the genetic underpinnings of rheumatoid arthritis (RA). Genome scans using these models have led to the detection of arthritis regulatory quantitative trait loci (QTLs) on all but three chromosomes of the rat. Whereas some of the QTLs are model specific, others overlap between models. Some arthritis susceptibility and/or severity QTLs identified by genetic linkage analyses are corroborated by substitution mapping using congenic strains, whereas others are not. In these cases, testing alternate arthritis models proved to be useful to identify QTL effects. Nevertheless, development and testing of congenic substrains containing progressively shorter introgressed regions have not only fine mapped the location of the arthritis QTLs but also resulted in the identification of multiple QTLs within several originally identified individual QTL. Most of these studies progressed rapidly since 2001, when the rat genome sequence was published. Proof of principle for substitution mapping as a successful method for QTL gene discovery is provided by the positional cloning of Ncf1 as one of the arthritis QTLs in rats. This finding is encouraging for similar sustained dissection of all the other arthritis QTLs mapped in the rat. Identification of rat arthritis QTLs is expected to pave the way for discovery of yet-unidentified arthritis-causative genetic elements and/or pathways for RA in humans and potential development of targeted therapeutics. This review catalogs some of the recent advances made in QTL discovery projects of experimentally induced rat models of arthritis.
The Emerging Role of Arsenic Trioxide as an Immunomodulatory Agent in the Management of Multiple Myeloma
Authors: Kalmadi Sujith R. , Hussein Mohamad A.
Published: June 2006

Multiple myeloma is a clonal disorder of plasma cells which is considered incurable with currently available therapies. Substantial advances have been achieved in the past decade with the identification of cellular mechanisms that confer drug resistance. This has resulted in newer agents such as arsenic trioxide (Trisenox™), lenalidomide (Revlimid™) and bortezomib (Velcade™) with promising activity in this disease. In this review article we will outline the history, mechanisms of action, pharmacology, and clinical trials of arsenic trioxide in multiple myeloma.
Platelet Activation in Helicobacter pylori-Associated Idiopathic Thrombocytopenic Purpura: Eradication Reduces Platelet Activation but Seldom Improves Platelet Counts
Authors: Ahn Eugene R. , Tiede Maike P. , Jy Wenche , Bidot Carlos J. , Fontana Vincenzo , Ahn Yeon S.
Published: June 2006

Introduction: It has been suggested that Helicobacter pylori eradication often increases platelet counts in patients with chronic idiopathic thrombocytopenic purpura (ITP). In addition, H. pylori has been shown to induce platelet activation (CD62p or P-selectin expression) in previous studies. We assessed the response of platelet count and CD62p expression after eradication therapy in patients with ITP and H. pylori infection. Methods and Results: We prospectively studied 15 ITP patients diagnosed with H. pylori infection by serology and breath test. A follow-up breath test was used to document eradication. Two out of 15 patients showed improvement in platelet counts after 6 months, 1 of which may have had drug-induced thrombocytopenia. Overall, certain platelet response rate in our series was 6.7% (1/15). We found that platelet CD62p expression by flow cytometry was elevated in 10/15 (66.7%) H. pylori-infected patients, which is a statistically significant difference when compared with 3/33 (9.1%) control ITP patients seronegative for H. pylori (p = 0.002). In addition, eradication therapy decreased CD62p expression (p = 0.04). However, reduction in platelet activation was not associated with an increase in platelet counts (mean 72.4 × 109/l before and 68.7 after therapy; p = 0.4). Conclusion: In our series, platelet activation was common in ITP patients with H. pylori, and eradication therapy decreased platelet activation but seldom increased platelet counts. Increased platelet CD62p expression is a putative link between chronic infections and atherosclerosis, but further study is needed to clarify the implications of our observation.