bluuebunny/crossref_metadata_2025 huggingface dataset:
Geosciences research in East Antarctica (0°E–60°E): present status and future perspectives
Authors: Satish-Kumar M. , Hokada T. , Kawakami T. , Dunkley Daniel J.
Published: November 2008

In both palaeoenvironmental and palaeogeographical studies, Antarctica plays a unique role in our understanding of the history of the Earth. It has maintained a unique geographical position at the South Pole for long periods. As the only unpopulated continent, the absence of political barriers or short-term economic interests has allowed international collaborative science to flourish. Although 98% of its area is covered by ice, the coastal Antarctic region is one of the well-studied regions in the world. The integrity and success of geological studies lies in the fact that exposed outcrops are well preserved in the low-latitude climate. The continuing programme of the Japanese Antarctic Research Expedition focuses on the geology of East Antarctica, especially in the Dronning Maud Land and Enderby Land regions. Enderby Land preserves some of the oldest Archaean rocks on Earth, and the Mesoproterozoic to Palaeozoic history of Dronning Maud Land is extremely important in understanding the formation and dispersion of Rodinia and subsequent assembly of Gondwana. The geological features in this region have great significance in defining the temporal and spatial extension of orogenic belts formed by the collision of proto-continents. Present understanding of the evolution of East Antarctica in terms of global tectonics allows us to visualize how continents have evolved through time and space, and how far back in time the present-day plate-tectonic regime may have operated. Although several fundamental research problems still need to be resolved, the future direction of geoscience research in Antarctica will focus on how the formation and evolution of continents and supercontinents have affected the Earth's environment, a question that has been addressed only in recent years.
Early Palaeozoic metasomatism of the Archaean Napier Complex, East Antarctica
Authors: Carson Christopher J. , Ague Jay J.
Published: November 2008

Emplacement of post-tectonic Early Palaeozoic pegmatites on Tonagh Island, Napier Complex, East Antarctica, was accompanied by the introduction of aqueous low-salinity fluids at mid-
P
upper-amphibolite facies conditions (
c.
8 kbar,
c.
680 °C). Fluid–wall-rock interaction resulted in the development of spectacular alteration selvedges, in the immediate vicinity of the pegmatites, in adjacent Archaean orthogneisses. Archaean wall-rocks affected by the infiltration of aqueous fluids show contrasting patterns of K, Na and Ca metasomatism, which we demonstrate was fundamentally controlled by disequilibrium of invading fluids with wall-rock feldspars, rather than fluid flow up or down regional pressure or temperature gradients. Other species, such as the rare earth elements (REE; except Eu), Y, P, Rb, Th, U and Pb, for example, show significant enrichment in the metasomatized wall-rock in both examples studied. Enrichment of P (and Y), sympathetic with that of REE enrichment, is consistent with recent suggestions that REE transport in fluids may be enhanced by complexing with dissolved P and Y compounds. Dehydration and partial melting of previously unmetamorphosed sedimentary rocks, underthrust beneath the SW Napier Complex, has been long considered a viable source for felsic pegmatites (and associated fluids) observed in that region. Our results are consistent with the hypothesis that underplated sedimentary rocks were a viable source for pegmatite melt and aqueous fluids. Furthermore, as our study demonstrates a plausible relationship between Early Palaeozoic (
c.
500–530 Ma) pegmatites and fluid infiltration, we suggest that dehydration and prograde partial melting of the underthrust sedimentary rocks beneath the Napier Complex occurred, at least in part, by convergent Early Palaeozoic tectonism.
Origin of xenocrystic garnet and kyanite in clinopyroxene-hornblende-bearing adakitic meta-tonalites from Cape Hinode, Prince Olav Coast, East Antarctica
Authors: Hiroi Yoshikuni , Motoyoshi Yoichi , Ishikawa Naoto , Hokada Tomokazu , Shiraishi Kazuyuki
Published: November 2008

Xenocrystic garnet and kyanite, in addition to clinopyroxene and rare orthopyroxene, are newly found to occur in middle Proterozoic slightly metamorphosed adakitic trondhjemites and tonalites (meta-tonalites) at Cape Hinode on the eastern Prince Olav Coast in the latest Proterozoic–Early Palaeozoic Lützow-Holm Complex, East Antarctica. Textural and compositional features of garnet and kyanite suggest that these minerals formed most probably as restite phases of partial melting of mid-ocean ridge basalt (MORB) between 15 and 20 kbar pressure, and were entrained by the tonalitic magmas, which underwent fractional crystallization upon ascent to form cumulates that were also entrained and metamorphosed to basic–intermediate granulite blocks. Available geochronological data for the meta-tonalites indicate that all these events including MORB formation took place in the middle Proterozoic. The meta-tonalites and associated basic, calc-silicate, and pelitic rocks were emplaced as an allochthonous block in the Lützow-Holm Complex at the waning stage of its main regional metamorphism, most probably as a part of the final amalgamation of East and West Gondwana into the Gondwana supercontinent.
Kornerupine
sensu stricto
associated with mafic and ultramafic rocks in the Lützow-Holm Complex at Akarui Point, East Antarctica: what is the source of boron?
Authors: Kawakami T. , Grew E. S. , Motoyoshi Y. , Shearer C. K. , Ikeda T. , Burger P. V. , Kusachi I.
Published: November 2008

Kornerupine, (□, Mg, Fe)(Al, Mg, Fe)
9
(Si, Al, B)
5
O
21
(OH, F), is known from only five mafic or ultramafic settings worldwide (of the >70 localities overall). We report a sixth occurrence from Akarui Point in the Lützow-Holm Complex, East Antarctica, where two ruby corundum (0.22–0.34 wt% Cr
2
O
3
)–plagioclase lenses are found at the same structural level as boudinaged ultrabasic rocks in hornblende gneiss and amphibolite. Ion microprobe analyses of kornerupine give 13–59 ppm Be, 181–302 ppm Li, and 5466–6812 ppm B, corresponding to 0.38–0.47 B per 21.5 O; associated sapphirine also contains B (588–889 ppm). Peak metamorphic conditions are estimated to be 770–790 °C and 7.7–9.8 kbar. Kornerupine encloses tourmaline and plagioclase, which suggests the prograde reaction tourmaline (1) + plagioclase (>An34)+ sapphirine±spinel→kornerupine+corundum (ruby)+plagioclase (<An82)±(fluid or melt). Alternatively, kornerupine and tourmaline could have formed sequentially under nearly constant
P
–
T
conditions during the infiltration of fluid that was originally B-bearing, but then progressively lost Na (or gained Ca) and B through reaction with mafic rocks. Kornerupine later reacted with H
2
O–CO
2
fluid in cracks at
P
–
T
conditions in the andalusite stability field: kornerupine+plagioclase+(Na, K, ± Si in fluid)→tourmaline+biotite+corundum (sapphire)± magnesite±andalusite+(Ca in fluid). Secondary tourmaline differs from the included tourmaline in containing less Ti and having a higher Na/(Na+Ca+K) ratio. There are two possible scenarios for introducing B into the lenses: (1) infiltration of boron-bearing aqueous fluids released by prograde breakdown of muscovite in associated metasedimentary rocks; (2) hydrothermal alteration of mafic and ultramafic rocks by seawater prior to peak metamorphism. The latter scenario is consistent with an earlier suggestion that Akarui Point could be part of an ophiolite complex developed between the Yamato–Belgica and Rayner complexes.
Empirical thermometer of TiO
2
in quartz for ultrahigh-temperature granulites of East Antarctica
Authors: Kawasaki Toshisuke , Osanai Yasuhito
Published: November 2008

Two preliminary experiments, heating of rutilated quartz grains with 0.082 wt% TiO
2
on average from Bunt Island, Napier Complex, East Antarctica and a synthetic TiO
2
–SiO
2
(rutile–cristobalite) system in air at 1300 °C for 39 days, showed increasing solubility of TiO
2
in silica minerals with temperature. Bunt quartz was converted to cristobalite and traversed by many transparent seams with the disappearence of needles and spots of rutile. Unreacted host grains retained many fine needles of rutile. The seams are homogeneous and slightly enriched in TiO
2
up to 0.149 wt% on average, which is about one-fifth lower than that of the synthesized TiO
2
–SiO
2
cristobalite (0.767 wt% on average). Area analyses with an electron beam in the raster mode at a magnification of ×5000 gave 0.308 wt% TiO
2
for the bulk composition of the Bunt quartz. This indicates that needles of rutile exsolved from the TiO
2
-saturated quartz at the cooling stage, or during retrograde metamorphism. Natural examples of quartz in geologically and petrologically well-characterized metamorphic rocks were chemically analysed to examine the temperature controls on the Ti saturation level in quartz. The TiO
2
content of quartz in equilibrium with rutile increases sensitively with the metamorphic temperature, which can be expressed as

T
(
°
C
)
=
−
5895
/
(
ln

X

TiO

2

Qtx

+
1.729
)
−
273

where
X

TiO
2

Qtz
is the mole fraction of TiO
2
, or the number of Ti atoms per formula unit based on a two-oxygen atom normalization. This empirical equation is very useful to evaluate the metamorphic temperatures for ultrahigh-temperature granulites. The temperatures calculated by the existing Ti-in-quartz thermometer are about 200 °C higher than those estimated by the present thermometer, potentially because of underestimates of Ti solubility in quartz in the previous calibration.
An overview of geological studies of JARE in the Napier Complex, Enderby Land, East Antarctica
Authors: Ishizuka Hideo
Published: November 2008

Subsequent to the reconnaissance fieldwork in 1982, the Japanese Antarctic Research Expedition (JARE) carried out extensive geological studies that focused on structural and tectonic aspects, petrology, geochemistry and geochronology of the Napier Complex in Enderby Land, East Antarctica. Detailed field investigations in several key areas, including geological mapping of the Mt. Riiser-Larsen area and Tonagh Island, revealed that the Napier Complex comprises layered and massive gneiss units, of which the layered unit is composed of garnet felsic gneiss, orthopyroxene felsic gneiss, pelitic and basic gneisses, impure quartzite, and minor metamorphosed banded iron formation, whereas the massive unit consists mainly of orthopyroxene felsic gneiss. The boundary between the units is transitional in the Mt. Riiser-Larsen area, in which metamorphosed anorthosite and ultramafic rocks occur as thin layers, or blocks or pods, but on Tonagh Island the boundary is closely associated with the shear zone. Nine deformation episodes (D
1
–D
9
) were suggested for Tonagh Island. These results of fieldwork were presented in detail in two geological maps. Geochemical studies showed that (1) garnet–sillimanite gneisses and garnet-rich felsic gneisses were derived from mudstone and sandstone, respectively, both enriched in MgO, Cr and Ni; (2) orthopyroxene felsic gneisses have a close REE affinity with Archaean tonalite–trondhjemite–granodiorite (TTG); (3) basic gneisses were derived from light rare earth element (LREE)-enriched or -depleted basalts; (4) meta-ultramafic rocks are comparable with komatiite and related depleted mantle peridotite. This suite of protoliths is reminiscent of Archaean greenstone–granite belts. Precise analyses of physical conditions of metamorphism were carried out by using reliable approaches such as feldspar thermometry, alumina content of orthopyroxene, inverted pigeonite and bulk-rock compositions, and clino- and orthopyroxene compositions with different textures (porphyroblastic and neoblastic), and the results suggested that the maximum metamorphic temperature might have reached 1130 °C (i.e. ultrahigh-temperature (UHT) metamorphism).
P
–
T
evolution of the Napier UHT metamorphism was examined by analyses of reaction textures combined with fluid inclusion studies, suggesting both clockwise (Bunt Island) and counterclockwise (Mt. Riiser-Larsen and Tonagh Island)
P
–
T
–
t
paths. U–Pb sensitive high-resolution ion microprobe and secondary ionization mass spectrometry zircon ages from the Mt. Riiser-Larsen area and Tonagh Island indicate three stages of protolith formation at around 3.28–3.23, 3.07 and 2.68–2.63 Ga, and two contrasting ages for the timing of peak UHT metamorphism at either
c.
2.55 or
c.
2.51–2.45 Ga. On the basis of these results, more comprehensive studies on the Napier Complex are essential in the future for understanding (1) the role and age of TTG protolith and (2) the origin and timing of UHT metamorphism.
Phloem Transport: Cellular Pathways and Molecular Trafficking
Authors: Turgeon Robert , Wolf Shmuel
Published: November 2008

The phloem transports nutrients, defensive compounds, and informational signals throughout vascular plants. Sampling the complex components of mobile phloem sap is difficult because of the damage incurred when the pressurized sieve tubes are breached. In this review we discuss sampling methods, the artifacts that can be introduced by different sampling procedures, the intricate pathways by which materials enter and exit the phloem, and the major types of compounds transported. Loading and unloading patterns are largely determined by the conductivity and number of plasmodesmata and the position-dependent function of solute-specific, plasma membrane transport proteins. Recent evidence indicates that mobile proteins and RNA are part of the plant's long-distance communication signaling system. Evidence also exists for the directed transport and sorting of macromolecules as they pass through plasmodesmata. A future challenge is to dissect the molecular and cellular aspects of long-distance macromolecular trafficking in the signal transduction pathways of the whole plant.
Hepatocyte growth factor regulates the development of highly pure cultured chief cells from rat stomach by stimulating chief cell proliferation in vitro
Authors: Tashima Kimihito , Zhang Songhua , Ragasa Regina , Nakamura Eiji , Seo Ji Hye , Muvaffak Asli , Hagen Susan J.
Published: November 2008

The physiology of gastric epithelial cells is often studied by using cancer cell lines, which may or may not provide information relevant to normal cells. Because few models exist to study chief cell physiology in vitro, our purpose was to develop primary cultured chief cells from rodent species that are structurally and functionally similar to native chief cells. For this, isolated chief cells from the rat stomach, purified by counterflow elutriation and density gradient centrifugation, were grown in media with growth factors. Purity and the continuity of tight junctions were determined, and permeability, viability, transepithelial resistance (TER), cell number and proliferation, and pepsinogen secretion in response to carbachol were measured. When plated in media alone or with basic fibroblast growth factor, the isolated chief cells attached by 2 days and were confluent by 4 days after seeding. However, tight junctions were discontinuous, TER was less than 300 Ω·cm2, and permeability was high. In contrast, chief cells incubated with hepatocyte growth factor (HGF) were confluent in 3 days and had a TER greater than 2,000 Ω·cm2, continuous tight junctions, and low permeability. EGF was intermediate. HGF facilitated monolayer development by increasing cell number, which occurred by the proliferation of chief cells. Chief cell cultures, grown with HGF, consisted of more than 99% gastric intrinsic factor-expressing cells and showed robust pepsinogen secretion. Coexpression studies for neck and chief cell markers suggest that the cultures are a mixture of mature, immature, and transitional zone cells. This model will be useful for investigating mechanisms that regulate chief cell physiology in health and disease.
Effect of acute resistance exercise and sex on human patellar tendon structural and regulatory mRNA expression
Authors: Sullivan Bridget E. , Carroll Chad C. , Jemiolo Bozena , Trappe Scott W. , Magnusson S. Peter , Døssing Simon , Kjaer Michael , Trappe Todd A.
Published: November 2008

Tendon is mainly composed of collagen and an aqueous matrix of proteoglycans that are regulated by enzymes called matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Although it is known that resistance exercise (RE) and sex influence tendon metabolism and mechanical properties, it is uncertain what structural and regulatory components contribute to these responses. We measured the mRNA expression of tendon's main fibrillar collagens (type I and type III) and the main proteoglycans (decorin, biglycan, fibromodulin, and versican) and the regulatory enzymes MMP-2, MMP-9, MMP-3, and TIMP-1 at rest and after RE. Patellar tendon biopsy samples were taken from six individuals (3 men and 3 women) before and 4 h after a bout of RE and from a another six individuals (3 men and 3 women) before and 24 h after RE. Resting mRNA expression was used for sex comparisons (6 men and 6 women). Collagen type I, collagen type III, and MMP-2 were downregulated ( P < 0.05) 4 h after RE but were unchanged ( P > 0.05) 24 h after RE. All other genes remained unchanged ( P > 0.05) after RE. Women had higher resting mRNA expression ( P < 0.05) of collagen type III and a trend ( P = 0.08) toward lower resting expression of MMP-3 than men. All other genes were not influenced ( P > 0.05) by sex. Acute RE appears to stimulate a change in collagen type I, collagen type III, and MMP-2 gene regulation in the human patellar tendon. Sex influences the structural and regulatory mRNA expression of tendon.
Early Prenatal Diagnosis of Cloacal Exstrophy with Fetal Magnetic Resonance Imaging
Authors: Gobbi D. , Fascetti Leon F. , Tregnaghi A. , Gamba P.G. , Midrio P.
Published: November 2008

Prenatal diagnosis of cloacal exstrophy can be challenging during pregnancy and, subsequently, the counseling very difficult. Available ultrasonographic criteria may be inadequate, especially in early gestational ages. A case of early prenatal detection of cloacal exstrophy with fetal magnetic resonance imaging is reported herein for the first time.
Turkey Coronavirus Non-Structure Protein NSP15 – An Endoribonuclease
Authors: Cao Jianzhong , Wu Ching-Ching , Lin Tsang Long
Published: November 2008

Turkey coronavirus (TCoV) polyprotein was predicted to be cleaved into 15 non-structural proteins (nsp2 to nsp16), but none of these nsps have been characterized. TCoV nsp15 consists of 338 residues and shares 40% sequence similarity to U-specific Nidovirales endoribonuclease (NendoU) of severe acute respiratory syndrome coronavirus. Objective: The purpose of the present study was to characterize TCoV nsp15. Methods: The TCoV nsp15 gene was cloned into pTriEX1 and expressed as a C-terminal His-tagged recombinant protein in BL21 (DE3). The recombinant nsp15 was purified by Ni-NTA resin. Synthetic RNA substrates were used to determine the substrate specificity of the TCoV nsp15. RNA zymography was used to determine the active form of the nsp15. Results: The TCoV nsp15 did not cleave DNA but degraded total cellular RNA. The TCoV nsp15 cleaved single-stranded (ss) RNA at the uridylate site. The TCoV nsp15 cleaved hairpin RNA, pRNA, and double-stranded RNA (dsRNA) of infectious bursal disease virus very slowly, implying that dsRNA is not a good substrate for the TCoV nsp15. No divalent metal ion was required for in vitro enzymatic activity of the TCoV nsp15. The active form of the TCoV nsp15 was a homohexamer and disulfide bond was essential for the enzymatic activity. Conclusion: The TCoV nsp15 is a NendoU but has some characteristics different from other NendoU.
Long-Term Follow-up of Patients Treated for Thyrotoxicosis Using the Achilles’ Reflex Time
Authors: Nordyke R.A.
Published: November 2008

Hypothyroidism commonly occurs after both radioiodineand surgical treatment of thyrotoxicosis. Since the incidence increases with the passage of time, it is important to follow all such patients for life. A system is presented which makes use of clinical judgement and the measured Achilles’ reflex time. In persons with easily reproducible reflexes this combination may be used to assure the continued euthyroid state after it has been reached, to suggest the presence of hypothyroidism, and to verify the hypothyroidism once suspected. Application of the method may help to reduce the large pool of patients with post-treatment hypothyroidism.
Induction of Ovulation with Human Gonadotrophins: Factors Affecting Ovulation, Pregnancy and Complications
Authors: Crooke A.C. , Eleftheriadis G. , Bertrand P.V.
Published: November 2008

All results on 106 women with failure of ovulation who were treated here with gonadotrophins up to November 1968 are summarised. Twenty-three patients failed to ovulate as judged by their excretion of pregnanediol, 39 appeared to ovulate without conceiving and 44 patients conceived and had 56 pregnancies. The dosage of FSH required to induce ovulation varied between 500 and 16,150 IU per monthly course. Adverse results of therapy were nine mild and two severe cases of hyperstimulation syndrome in 203 months with positive pregnanediol responses and there were five pregnancies with triplets or more. An additional case of triplets is included in the appendix. These complications did not appear to be associated with high dosages of FSH or HCG but were associated with elevated excretions of oestriol at the time of giving the ovulating dose of HCG and at the mid-cycle peak and of pregnanediol 8 days after the ovulating dose of HCG. Treatment with FSH which contained little LH was associated with fewer pregnancies with triplets or more but with more abortions than were those with FSH rich in LH. The importance of these results in modifying the method of treatment with gonadotrophins is discussed.
Relative Oestrogen Concentrations in Human Tumours
Authors: Braunsberg H. , James V.H.T. , Irvine W.T. , Carter A.E.
Published: November 2008

Using a technique of constant infusion of tritium labeled oestradiol, the relative concentration of this hormone in malignant breast tumours, and other human tissues has been studied. Some, but not all breast tumours showed a higher oestrogen concentration than did normal breast or tumours from other body sites. No significant difference was found whentumours from testosterone or drostanolone treated patients were studied.
Recent Studies on the Estimation of Human Pituitary Gonadotrophins in Urine in Clinical Conditions
Authors: Loraine J.A. , Adamopoulos D.A.
Published: November 2008

(a) In women approaching the menopause urinary LHlevels tend to be high while those of FSH are within the normal range for subjects during the reproductive life. In a proportion of women in this group high LH levels can occur in absence of any clinical symptoms of the menopause, (b) In postmenopausal subjects urinary LH output is significantly higher than in normally menstruating women and is in the same range as that found in the perimenopausal group, (c) In patients with Turner’s syndrome excretion values for LH are variable and are not correlated with the chromosomal karyotype. In phenotypic males with a 47, XYY sex chromosomal constitution, urinary LH readings are grossly elevated, (d) In infertile women treated with clomiphene a significant effect on urinary LH output was not observed, suggesting that the compound did not act directly on the pituitary-hypothalamic axis to produce release of this hormone, (e) In patients treated on a long term basis with oral contraceptives, urinary LH activity was not completely suppressed, levels being within or at the lower end of the normal range for women during reproductive life.
Myxoedema Crisis
Authors: Hausmann W.
Published: November 2008

Fourteen cases of myxoedema crisis have been reportedand 93 additional cases have been collected from the literature. Hypothermia, coma and shock have been identified as the main clinical features of crisis. It has been pointed out that while clouding of consciousness is universal, coma is of doubtful prognostic significance. The importance of hypothermia in prognosis has been stressed. Various stress factors have been described which may initiate crisis especially respiratory infections and epileptic fits. The urgency of adequate treatment has been emphasised but overenthusiastic treatment is only slightly less dangerous than delay and inadequate treatment. However, even the best available treatment will only lead to a moderate improvement in outlook and the only successful way is prevention.
Abnormal Iodoproteins in Human Congenital Goiter
Authors: Andreoli M. , Monaco F. , D’Armiento M. , Fontana S. , Scuncio G. , Salabé G.B.
Published: November 2008

Soluble iodoproteins from three congenitally goitrousthyroids have been isolated by salt fractionation followed by DEAE-cellulose chromatography, gel filtration and density gradient centrifugation and characterized by analytical ultracentrifugation, polyacrylamide electrophoresis and by immunological procedures. It has been shown that the amount of 19 S thyroglobulin is strikingly decreased, the soluble proteins consisting of several slow-sedimenting iodocompounds: (3 S-6S) not identified as any of the known thyroglobulin subunit. The immunological data suggest that some of the heterogenous 3 S-6 S fractions is related to the thyroglobulin metabolism.
Influence of Time Factor on the Restoration of Adrenal Weight and Cortical Functions in Hypophysectomized Rats
Authors: Barthe P.L. , Desaulles P.A.
Published: November 2008

It has been shown that repeated doses of a long-acting synthetic ACTH preparation (Synacthen Depot®) are able to restore adrenal function in rats with adrenal atrophy (induced by hypophysectomizing the animals and leaving them untreated for varying periods of time). Restoration of responsiveness to single doses of synthetic ACTH (Synacthen®) can be effected after a relatively short time (10 days’ treatment is sufficient for this purpose); restoration of adrenal weight, how ever, calls for at least 30 days’ treatment with the doses used in this study. In other words, the animals’ adrenals, though greatly reduced in size, are nevertheless capable of displaying a virtually normal response to stimulation. This discrepancy indicates that, during the stimulation test, they must be more active than normal adrenals. This phenomenon cannot be accounted for at present.
Lipolytic Enzymes and the Action of ACTH on Lipid Metabolism in Rat Adrenals
Authors: Macho Ladislav , Palkovič Michal
Published: November 2008

A pronounced lipolytic activity was found in homogenate of rat adrenal gland. The pH optimum of adrenal lipase was wide and the highest lipolytic activity was found at pH 8.5. An inhibition of lipolytic activity in the presence of 1 M NaCl, protamine sulphate, diisopropylfluorophosphate at pH 8,5 and after the addition on NaF at pH 7.2 was noted. Heparine activated the lipase activity at pH 8.5. These result suggested that both lipoprotein like lipase and neutral ‘tissue’ lipase are present in rat adrenal gland. An activation of adrenal lipase activity with ACTH and 3’5’ cyclic adenosine monophosphate was demonstrated. The other pituitary hormones and adrenaline did not increased the adrenal lipase activity.
Calcific Aortic Stenosis
Authors: Rajamannan Nalini M.
Published: November 2008

Calcific aortic stenosis is the most common indication for surgical valve replacement in the United States. For years this disease has been described as a passive degenerative process during which serum calcium attaches to the valve surface and binds to the leaflet to form nodules. Therefore, surgical treatment of this disease has been the approach toward relieving outflow obstruction in these patients. Recent studies demonstrate an association between atherosclerosis and its risk factors for aortic valve disease. In 2008, there are increasing number of epidemiology and experimental studies to provide evidence that this disease process is not a passive phenomena. There is an active cellular process that develops within the valve leaflet and causes a regulated bone formation to develop. If the atherosclerotic hypothesis is important in the initiation of aortic stenosis, then treatments used in slowing the progression of atherosclerosis may be effective in patients with aortic valve disease. This review will discuss the pathogenesis and the potential for medical therapy in the management of patients with calcific aortic stenosis by examining the lessons provided from the experimental research.
Efficacy of Simvastatin Treatment of Valvular Interstitial Cells Varies With the Extracellular Environment
Authors: Monzack Elyssa L. , Gu Xiaoxiao , Masters Kristyn S.
Published: November 2008

Objective—

The lack of therapies that inhibit valvular calcification and the conflicting outcomes of clinical studies regarding the impact of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors on valve disease highlight the need for controlled investigations to characterize the interactions between HMG-CoA reductase inhibitors and valve tissue. Thus, we applied multiple in vitro disease stimuli to valvular interstitial cell (VIC) cultures and examined the impact of simvastatin treatment on VIC function.

Methods and Results—

VICs were cultured on 3 different substrates that supported various levels of nodule formation. Transforming growth factor (TGF)-β1 was also applied as a disease stimulus to VICs on 2-D surfaces or encapsulated in 3-D collagen gels and combined with different temporal applications of simvastatin. Simvastatin inhibited calcific nodule formation in a dose-dependent manner on all materials, although the level of statin efficacy was highly substrate-dependent. Simvastatin treatment significantly altered nodule morphology, resulting in dramatic nodule dissipation over time, also in a substrate-dependent manner. These effects were mimicked in 3-D cultures, wherein simvastatin reversed TGF-β1–induced contraction. Decreases in nodule formation were not achieved via the HMG-CoA reductase pathway, but were correlated with decreases in ROCK activity.

Conclusions—

These studies represent a significant contribution to understanding how simvastatin may impact heart valve calcification.
Serotonin and Angiotensin Receptors in Cardiac Fibroblasts Coregulate Adrenergic-Dependent Cardiac Hypertrophy
Authors: Jaffré Fabrice , Bonnin Philippe , Callebert Jacques , Debbabi Haythem , Setola Vincent , Doly Stéphane , Monassier Laurent , Mettauer Bertrand , Blaxall Burns C. , Launay Jean-Marie , Maroteaux Luc
Published: November 2008

By mimicking sympathetic stimulation in vivo, we previously reported that mice globally lacking serotonin 5-HT
2B
receptors did not develop isoproterenol-induced left ventricular hypertrophy. However, the exact cardiac cell type(s) expressing 5-HT
2B
receptors (cardiomyocytes versus noncardiomyocytes) involved in pathological heart hypertrophy was never addressed in vivo. We report here that mice expressing the 5-HT
2B
receptor solely in cardiomyocytes, like global 5-HT
2B
receptor–null mice, are resistant to isoproterenol-induced cardiac hypertrophy and dysfunction, as well as to isoproterenol-induced increases in cytokine plasma-levels. These data reveal a key role of noncardiomyocytes in isoproterenol-induced hypertrophy in vivo. Interestingly, we show that primary cultures of angiotensinogen null adult cardiac fibroblasts are releasing cytokines on stimulation with either angiotensin II or serotonin, but not in response to isoproterenol stimulation, demonstrating a critical role of angiotensinogen in adrenergic-dependent cytokine production. We then show a functional interdependence between AT
1
Rs and 5-HT
2B
receptors in fibroblasts by revealing a transinhibition mechanism that may involve heterodimeric receptor complexes. Both serotonin- and angiotensin II–dependent cytokine production occur via a Src/heparin-binding epidermal growth factor–dependent transactivation of epidermal growth factor receptors in cardiac fibroblasts, supporting a common signaling pathway. Finally, we demonstrate that 5-HT
2B
receptors are overexpressed in hearts from patients with congestive heart failure, this overexpression being positively correlated with cytokine and norepinephrine plasma levels. Collectively, these results reveal for the first time that interactions between AT
1
and 5-HT
2B
receptors coexpressed by noncardiomyocytes are limiting key events in adrenergic agonist-induced, angiotensin-dependent cardiac hypertrophy. Accordingly, antagonists of 5-HT
2B
receptors might represent novel therapeutics for sympathetic overstimulation-dependent heart failure.
Protein Kinase G Modulates Human Myocardial Passive Stiffness by Phosphorylation of the Titin Springs
Authors: Krüger Martina , Kötter Sebastian , Grützner Anika , Lang Patrick , Andresen Christian , Redfield Margaret M. , Butt Elke , dos Remedios Cris G. , Linke Wolfgang A.
Published: November 2008

The sarcomeric titin springs influence myocardial distensibility and passive stiffness. Titin isoform composition and protein kinase (PK)A-dependent titin phosphorylation are variables contributing to diastolic heart function. However, diastolic tone, relaxation speed, and left ventricular extensibility are also altered by PKG activation. We used back-phosphorylation assays to determine whether PKG can phosphorylate titin and affect titin-based stiffness in skinned myofibers and isolated myofibrils. PKG in the presence of 8-pCPT-cGMP (cGMP) phosphorylated the 2 main cardiac titin isoforms, N2BA and N2B, in human and canine left ventricles. In human myofibers/myofibrils dephosphorylated before mechanical analysis, passive stiffness dropped 10% to 20% on application of cGMP-PKG. Autoradiography and anti-phosphoserine blotting of recombinant human I-band titin domains established that PKG phosphorylates the N2-B and N2-A domains of titin. Using site-directed mutagenesis, serine residue S469 near the COOH terminus of the cardiac N2-B–unique sequence (N2-Bus) was identified as a PKG and PKA phosphorylation site. To address the mechanism of the PKG effect on titin stiffness, single-molecule atomic force microscopy force–extension experiments were performed on engineered N2-Bus–containing constructs. The presence of cGMP-PKG increased the bending rigidity of the N2-Bus to a degree that explained the overall PKG-mediated decrease in cardiomyofibrillar stiffness. Thus, the mechanically relevant site of PKG-induced titin phosphorylation is most likely in the N2-Bus; phosphorylation of other titin sites could affect protein–protein interactions. The results suggest that reducing titin stiffness by PKG-dependent phosphorylation of the N2-Bus can benefit diastolic function. Failing human hearts revealed a deficit for basal titin phosphorylation compared to donor hearts, which may contribute to diastolic dysfunction in heart failure.
Inflammatory Interaction Between LIGHT and Proteinase-Activated Receptor-2 in Endothelial Cells
Authors: Sandberg Wiggo J. , Halvorsen Bente , Yndestad Arne , Smith Camilla , Otterdal Kari , Brosstad Frank R. , Frøland Stig S. , Olofsson Peder S. , Damås Jan K. , Gullestad Lars , Hansson Göran K. , Øie Erik , Aukrust Pål
Published: November 2008

The interaction between inflammatory cytokines and endothelial cells is a critical step in atherogenesis leading to endothelial dysfunction and inflammation. We have previously reported that the tumor necrosis factor superfamily member LIGHT could be involved in atherogenesis through its ability to promote vascular inflammation. In the present study we identified proteinase-activated receptor (PAR)-2 as an inflammatory mediator that was markedly enhanced by LIGHT in endothelial cells. We also found that LIGHT acted synergistically with PAR-2 activation to promote enhanced release of the proatherogenic chemokines interleukin-8 and monocyte chemoattractant protein-1, underscoring that the interaction between LIGHT and PAR-2 is biologically active, promoting potent inflammatory effects. We showed that the LIGHT-mediated upregulation of PAR-2 in endothelial cells is mediated through the HVEM receptor, involving Jun N-terminal kinase signaling pathways. A LIGHT-mediated upregulation of PAR-2 mRNA levels was also found in human monocytes when these cells were preactivated by tumor necrosis factor α. We have previously demonstrated increased plasma levels of LIGHT in unstable angina patients, and here we show a similar pattern for PAR-2 expression in peripheral blood monocytes. We also found that LIGHT, LIGHT receptors, and PAR-2 showed enhanced expression, and, to some degree, colocalization in endothelial cells and macrophages, in the atherosclerotic plaques of ApoE
−/−
mice, suggesting that the inflammatory interaction between LIGHT and PAR-2 also may be operating in vivo within an atherosclerotic lesion. Our findings suggest that LIGHT/PAR-2–driven inflammation could be a pathogenic loop in atherogenesis potentially representing a target for therapy in this disorder.
Protective Effect of Delayed Treatment With Low-Dose Glibenclamide in Three Models of Ischemic Stroke
Authors: Simard J. Marc , Yurovsky Vladimir , Tsymbalyuk Natalia , Melnichenko Ludmila , Ivanova Svetlana , Gerzanich Volodymyr
Published: November 2008

Background and Purpose—

Ischemia/hypoxia induces de novo expression of the sulfonylurea receptor 1-regulated NC(Ca-ATP) channel. In rodent models of ischemic stroke, early postevent administration of the sulfonylurea, glibenclamide, is highly effective in reducing edema, mortality, and lesion volume, and in patients with diabetes presenting with ischemic stroke, pre-event plus postevent use of sulfonylureas is associated with better neurological outcome. However, the therapeutic window for treatment with glibenclamide has not been studied.

Methods—

We examined the effect of low-dose (nonhypoglycemogenic) glibenclamide in 3 rat models of ischemic stroke, all involving proximal middle cerebral artery occlusion (MCAo): a thromboembolic model, a permanent suture occlusion model, and a temporary suture occlusion model with reperfusion (105 minutes occlusion, 2-day reperfusion). Treatment was started at various times up to 6 hours post-MCAo. Lesion volumes were measured 48 hours post-MCAo using 2,3,5-triphenyltetrazolium chloride.

Results—

Glibenclamide reduced total lesion volume by 53% in the thromboembolic MCAo model at 6 hours, reduced corrected cortical lesion volume by 51% in the permanent MCAo model at 4 hours, and reduced corrected cortical lesion volume by 41% in the temporary MCAo model at 5.75 hours (
P
<0.05 for all 3). Analysis of pooled data from the permanent MCAo and temporary MCAo series indicated a sigmoidal relationship between hemispheric swelling and corrected cortical lesion volume with the half-maximum cortical lesion volume being observed with 10% hemispheric swelling.

Conclusions—

Low-dose glibenclamide has a strong beneficial effect on lesion volume and has a highly favorable therapeutic window in several models of ischemic stroke.
Effect of Weight Reduction with Dietary Intervention on Arterial Distensibility and Endothelial Function in Obese Men
Authors: Miyaki Asako , Maeda Seiji , Yoshizawa Mutsuko , Misono Maiko , Saito Yoko , Sasai Hiroyuki , Endo Takayuki , Nakata Yoshio , Tanaka Kiyoji , Ajisaka Ryuichi
Published: November 2008

Obesity and reduction in central arterial distensibility, respectively, have been identified as powerful and independent risk factors for cardiovascular disease. However, the effect of weight reduction on central arterial function in obese subjects has not yet been clarified. We investigated whether low-calorie diet-induced weight reduction affects central arterial distensibility and endothelial function in middle-aged obese men. Twelve obese men (age: 45 ± 2 yrs, BMI: 30±1 kg/m2) completed a 12-week dietary intervention. Caloric restriction induced significantly weight loss and decrease in BMI. After the program, carotid arterial compliance significantly increased and β-stiffness index and aortic pulse-wave velocity remarkably decreased. Concentrations of plasma endothelin-1 (ET-1) significantly decreased and plasma nitric oxide (NO) markedly increased after the program. Weight reduction by low-calorie diet in obese men increases central arterial distensibility, which may contribute to the improvement in endothelial function, as noted by a decrease in ET-1 and an increase in NO.
Diabetic Ketoacidosis: A Current Appraisal of Pathophysiology and Management
Authors: Koul Pulin B.
Published: November 2008

Diabetic ketoacidosis (DKA) is a frequent abnormal metabolic entity seen in high-dependency units such as critical care units and in the emergency department. Having an understanding of its pathophysiology, a consequence of absent to low insulin levels, delineates the clinical presentation. Most clinical features are caused by hyperglycemia and acidosis, including weight loss. The newer management modalities are discussed that include the need for intensive laboratory workup, meticulous monitoring of the insulin, and fluid management. Among the complications, cerebral edema (CE) is the most dreaded, albeit with low incidence. The new insights into its pathophysiology and management are outlined, and a timeline for management of DKA is proposed.
Promoting Reading in Children: Do Reading Practices Differ in Children With Developmental Problems?
Authors: Butz Arlene M. , Crocetti Michael , Thompson Richard E. , Lipkin Paul H.
Published: November 2008

Objective The objective of this study was to describe and compare reading practices in caregivers of children with developmental/behavioral problems (DEV) to caregivers of children without developmental problems attending a general pediatric clinic (GEN).

Method Cross-sectional, convenience samples of 321 caregivers of DEV and GEN children self-report reading practices including amount of daytime and nighttime reading, TV viewing, and number of books in the house. Reading 4 or more days per week is the primary outcome. Multivariate logistic regression analysis was used to compare reading 4 or more days per week with specific predictors. Odds ratios and 95% confidence intervals were reported.

Results Three hundred and twenty-one caregivers participated in the study (DEV 204, GEN 117). Mean number of books in home (51.1 ± 49.9), TV viewing hours per day (2.6 ± 2.0), and days or nights read per week (days, 4.9 ± 2.1; nights, 4.0 ± 2.4) did not differ by group. Caregivers reporting incomes at 200% above the federal poverty level (FPL) were more likely to engage in reading more than 4 days per week (odds ratio 5.32; 95% confidence intervals, 1.19, 23.81) after controlling for developmental status, caregiver education and age, and frequency of television viewing.

Conclusion Positive home reading practices were predicted by FPL in children with and without developmental or behavioral problems and while controlling for child group status (DEV or GEN), caregiver education and age, and amount of TV viewing. Reading promotion programs should focus on children from low socioeconomic environments regardless of disability risk status.
A Broken Heart—The Physician's Role: Bereaved Parents' Perceptions of Interactions with Physicians
Authors: Bright Katherine L. , Belew Huff Marlene , Hollon Karen
Published: November 2008

This survey study provides pediatricians the opportunity to hear directly from surviving parents and caretakers and is an initial step in developing training curricula for doctors and other health care professionals who wish to improve the effectiveness of their interactions with grieving families. A privately maintained listserve, originating in Kentucky, of bereaved parents and guardians was used to send written surveys via the U.S. Postal Service to those individuals living in Kentucky. Survey results include thematic concerns identified by the bereaved parents about physician interaction and actions at the time of a child's death. Although published guidelines are available for physicians attending to bereaved parents at the time of a child's death, these results suggest that the availability of guidelines alone may be insufficient and that more in-depth physician training and education are needed.
Parental Management of Childhood Diarrhea
Authors: Li Su-Ting T. , Klein Eileen J. , Tarr Phillip I. , Denno Donna M.
Published: November 2008

The objective was to determine the prevalence of therapies used by parents to manage acute diarrhea in their children and determine extent of parental adherence to current management guidelines and utilization of functional foods. Parents (N = 623) of children with diarrhea were surveyed in a tertiary care pediatric emergency department. Most (53%) treated their child's diarrhea with appropriate fluids, including oral rehydration solution (52%), but 14% used treatments not recommended in current guidelines (antidiarrheals, 8%; fluids high in simple sugars, 6%). In addition, 13% used functional foods (yogurt, 11%; probiotics, 4%). Children whose parents did not adhere to guidelines were older (OR 1.02; 95% CI 1.01-1.02 years) and Hispanic (OR 2.1; 95% CI 1.1-3.9). Although most parents use appropriate fluids to treat their children's diarrhea, functional foods and antidiarrheal medications were also frequently administered. Further data on effectiveness of functional foods and education regarding avoidance of potentially harmful medications are needed.
An Overview of Pediatric Dysphagia
Authors: Prasse Jane E. , Kikano George E.
Published: November 2008

Difficulty swallowing or dysphagia can be present in children and adults alike. Pediatric dysphagias have long been recognized in the literature. Certain groups of infants with specific developmental and/or medical conditions have been identified as being at high risk for developing dysphagia. Still others may present with a swallowing or feeding problem as their primary symptom. Left untreated, these problems in infants and children can lead to failure to thrive, aspiration pneumonias, gastroesophageal reflux, and/or the inability to establish and maintain proper nutrition and hydration. Awareness of the prevalence of pediatric dysphagia in today's population and the signs and symptoms of this condition aids in its treatment. Early detection of dysphagia in infants and children is important to prevent or minimize complications. This article provides a review of symptoms, etiologies, and resources available regarding management of this condition to help the primary care physician and the families of young children and infants in its management.
The Impact of Attitude Accessibility and Decision Style on Adolescents' Biased Processing of Health-Related Public Service Announcements
Authors: Lijiang Shen  , Monahan Jennifer L. , Rhodes Nancy , Roskos-Ewoldsen David R.
Published: November 2008

This article examines how cognitive structures and processes that highlight some aspects of messages but inhibit the salience of others affect adolescents' processing of public service announcements (PSAs). The cognitive structures assessed were attitude accessibility and decision styles (need for cognition and faith in intuition). A 2 (gender: male vs. female) × 2 (race: Caucasian vs. African American) × 4 (message type) mixed design with message type as a within-subjects factor was utilized. Three hundred twenty-five teens ( M age = 14.97) were randomly assigned to view one PSA of each type, presented in a random order. Multilevel modeling analyses showed that attitude accessibility and need for cognition interact with attitude to affect adolescents' biased processing while faith in intuition negatively predicts perceived message bias. Race and gender were also significant predictors of perceived message bias. Implications for message design and health communication are discussed.