bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discussion on Wang et al. (2000) ‘Chemistry of Hf-rich zircons from the Laoshan I- and A-type granites, Eastern China’, Mineralogical Magazine, 64, 867–877
Authors: Kempe U. , Gruner T. , Renno A. D. , Wolf D. , René M. 
Published: October 2004

AbstractWang et al. (2000) presented interesting new data on the occurrence of Hf-rich zircon in peralkaline granitic rocks. It is shown that the knowledge of the Hf distribution in zircon is important for the understanding of Zr/Hf ratios defined by whole-rock analysis. However, the processes leading to the unusual Zr/Hf fractionation are still poorly constrained. Some aspects are discussed further here. Analysis of available data demonstrates that extremely low Zr/Hf ratios found in topaz- and rare-metal bearing granites may be either a primary signature of some evolved granitic melts or, alternatively, they are produced during albitization of the rocks. Topaz- and rare-metal bearing granites may be P-rich and contain zircon moderately enriched in Hf (2—9 wt.% HfO2). Another group is P-poor and the Hf content in accessory zircon is high (up to 35 wt.% HfO2). Both types of intrusions may occur within a single orogen as demonstrated by the example of the Hercynian magmatism in the Erzgebirge/Krušné hory region (Germany/Czech Republic).
Carbonate nodules of probable stromatolitic origin in amphibolite from the Neoproterozoic terrain of southern Israel
Authors: Bogoch R. , Shirav M. 
Published: October 2004

AbstractSeveral small bodies of massive to banded amphibolite occur within plagioclase-quartz-biotite hornblende gneiss at or close to its boundary with a quartz diorite pluton in the Neoproterozoic terrain of southern Israel. Entrapped within the amphibolite are nodules consisting mainly of calcite+talc, and rare banded marble. Remnant laminae and certain geochemical features such as the negative Ce anomaly and depleted δ13C of the nodules sugggest that they initially formed as stromatolites. The local geological setting of the amphibolites together with the presence of the enclosed meta-carbonates favoured an origin as sediments, although some of the geochemical data point to a basaltic precursor and some of the carbonates have a puzzlingly high (>1000 ppm) Ni content. The origin of the amphibolites is thus enigmatic.
Suprasubduction-zone peridotite in the northern USA Appalachians: evidence from mineral composition
Authors: Coish R. A. , Gardner P. 
Published: October 2004

AbstractMineral compositions of small peridotite bodies in an Ordovician collision zone of the Vermont Appalachians provide important clues to their tectonic environment of origin. The bodies have been deformed and partially serpentinized under greenschist- to lower amphibolite-facies conditions during the Ordovician and Devonian. Before serpentinization, the peridotite bodies were dunite as shown by their mineral assemblage and by their high MgO, and low Ti and Al whole-rock contents. Despite deformation and metamorphism, remnant olivine and spinel grains occur; their compositions are taken to represent conditions prior to regional metamorphic events. High Mg/(Mg+Fe) in olivine and very high Cr/(Cr+Al) in spinel indicate that the peridotites formed as highly-depleted mantle residues. The compositions are similar to those in harzburgite and dunite from some ophiolites and from fore-arc regions of subduction zones. Accordingly, the southern Vermont peridotites probably formed in a forearc, supra-subduction zone during the Early Palaeozoic. They were subsequently emplaced by obduction of the upper plate of an east-facing subduction complex.
Apolipoprotein A-I infiltration in rheumatoid arthritis synovial tissue: a control mechanism of cytokine production?
Authors: Bresnihan Barry , Gogarty Martina , FitzGerald Oliver , Dayer Jean-Michel , Burger Danielle 
Published: October 2004

AbstractThe production of tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) by monocytes is strongly induced by direct contact with stimulated T lymphocytes, and this mechanism may be critical in the pathogenesis of rheumatoid arthritis (RA). Apolipoprotein A-I (apoA-I) blocks contact-mediated activation of monocytes, causing inhibition of TNF-α and IL-1β production. This study examined the hypothesis that apoA-I may have a regulatory role at sites of macrophage activation by T lymphocytes in inflamed RA synovial tissue. Synovial tissue samples were obtained after arthroscopy from patients with early untreated RA or treated RA and from normal subjects. As determined by immunohistochemistry, apoA-I was consistently present in inflamed synovial tissue that contained infiltrating T cells and macrophages, but it was absent from noninflamed tissue samples obtained from treated patients and from normal subjects. ApoA-I staining was abundant in the perivascular areas and extended in a halo-like pattern to the surrounding cellular infiltrate. C-reactive protein and serum amyloid A were not detected in the same perivascular areas of inflamed tissues. The abundant presence of apoA-I in the perivascular cellular infiltrates of inflamed RA synovial tissue extends the observations in vitro that showed that apoA-I can modify contact-mediated macrophage production of TNF-α and IL-1β. ApoA-I was not present in synovium from patients in apparent remission, suggesting that it has a specific role during phases of disease activity. These findings support the suggestion that the biologic properties of apoA-I, about which knowledge is newly emerging, include anti-inflammatory activities and therefore have important implications for the treatment of chronic inflammatory diseases.
Proteotypic classification of spontaneous and transgenic mammary neoplasms
Authors: Mikaelian Igor , Blades Natalie , Churchill Gary A , Fancher Karen , Knowles Barbara B , Eppig Janan T , Sundberg John P 
Published: October 2004

Abstract
Introduction
Mammary tumors in mice are categorized by using morphologic and architectural criteria. Immunolabeling for terminal differentiation markers was compared among a variety of mouse mammary neoplasms because expression of terminal differentiation markers, and especially of keratins, provides important information on the origin of neoplastic cells and their degree of differentiation.

Methods
Expression patterns for terminal differentiation markers were used to characterize tumor types and to study tumor progression in transgenic mouse models of mammary neoplasia (mice overexpressing Neu (Erbb2), Hras, Myc, Notch4, SV40-TAg, Tgfa, and Wnt1), in spontaneous mammary carcinomas, and in mammary neoplasms associated with infection by the mouse mammary tumor virus (MMTV).

Results
On the basis of the expression of terminal differentiation markers, three types of neoplasm were identified: first, simple carcinomas composed exclusively of cells with a luminal phenotype are characteristic of neoplasms arising in mice transgenic for Neu, Hras, Myc, Notch4, and SV40-TAg; second, 'complex carcinomas' displaying luminal and myoepithelial differentiation are characteristic of type P tumors arising in mice transgenic for Wnt1, neoplasms arising in mice infected by the MMTV, and spontaneous adenosquamous carcinomas; and third, 'carcinomas with epithelial to mesenchymal transition (EMT)' are a characteristic feature of tumor progression in Hras-, Myc-, and SV40-TAg-induced mammary neoplasms and PL/J and SJL/J mouse strains, and display de novo expression of myoepithelial and mesenchymal cell markers. In sharp contrast, EMT was not detected in papillary adenocarcinomas arising in BALB/cJ mice, spontaneous adenoacanthomas, neoplasms associated with MMTV-infection, or in neoplasms arising in mice transgenic for Neu and Wnt1.

Conclusions
Immunohistochemical profiles of complex neoplasms are consistent with a stem cell origin, whereas simple carcinomas might originate from a cell committed to the luminal lineage. In addition, these results suggest that the initiating oncogenic events determine the morphologic features associated with cancer progression because EMT is observed only in certain types of neoplasm.
Effect of lung compliance and endotracheal tube leakage on measurement of tidal volume
Authors: Al-Majed Sami I , Thompson John E , Watson Kenneth F , Randolph Adrienne G 
Published: October 2004

Abstract
Introduction
The objective of this laboratory study was to measure the effect of decreased lung compliance and endotracheal tube (ETT) leakage on measured exhaled tidal volume at the airway and at the ventilator, in a research study with a test lung.

Methods
The subjects were infant, adult and pediatric test lungs. In the test lung model, lung compliances were set to normal and to levels seen in acute respiratory distress syndrome. Set tidal volume was 6 ml/kg across a range of simulated weights and ETT sizes. Data were recorded from both the ventilator light-emitting diode display and the CO2SMO Plus monitor display by a single observer. Effective tidal volume was calculated from a standard equation.

Results
In all test lung models, exhaled tidal volume measured at the airway decreased markedly with decreasing lung compliance, but measurement at the ventilator showed minimal change. In the absence of a simulated ETT leak, calculation of the effective tidal volume led to measurements very similar to exhaled tidal volume measured at the ETT. With a simulated ETT tube leak, the effective tidal volume markedly overestimated tidal volume measured at the airway.

Conclusion
Previous investigators have emphasized the need to measure tidal volume at the ETT for all children. When ETT leakage is minimal, it seems from our simulated lung models that calculation of effective tidal volume would give similar readings to tidal volume measured at the airway, even in small patients. Future studies of tidal volume measurement accuracy in mechanically ventilated children should control for the degree of ETT leakage.
Metabolic Syndrome Is Associated with Elevated Oxidative Stress and Dysfunctional Dense High-Density Lipoprotein Particles Displaying Impaired Antioxidative Activity
Authors: Hansel Boris , Giral Philippe , Nobecourt Estelle , Chantepie Sandrine , Bruckert Eric , Chapman M. John , Kontush Anatol 
Published: October 2004

AbstractA metabolic syndrome (MetS) phenotype is characterized by insulin-resistance, atherogenic dyslipidemia, oxidative stress, and elevated cardiovascular risk and frequently involves subnormal levels of high-density lipoprotein (HDL) cholesterol. We evaluated the capacity of physicochemically distinct HDL subfractions from MetS subjects to protect low-density lipoprotein against oxidative stress.MetS subjects presented an insulin-resistant phenotype, with central obesity and elevation in systolic blood pressure and plasma triglyceride, LDL-cholesterol, apolipoprotein B, glucose, and insulin levels. Systemic oxidative stress, assessed as plasma 8-isoprostanes, was significantly higher (3.7-fold) in MetS subjects (n = 10) compared with nonobese normolipidemic controls (n = 11). In MetS, small, dense HDL3a, 3b, and 3c subfractions possessed significantly lower specific antioxidative activity (up to −23%, on a unit particle mass basis) than their counterparts in controls. In addition, HDL2a and 3a subfractions from MetS patients possessed lower total antioxidative activity (up to −41%, at equivalent plasma concentrations). The attenuated antioxidative activity of small, dense HDL subfractions correlated with systemic oxidative stress and insulin resistance and was associated with HDL particles exhibiting altered physicochemical properties (core triglyceride enrichment and cholesteryl ester depletion).We conclude that antioxidative activity of small, dense HDL subfractions of altered chemical composition is impaired in MetS and associated with elevated oxidative stress and insulin resistance. Induction of selective increase in the circulating concentrations of dense HDL subfractions may represent an innovative therapeutic approach for the attenuation of high cardiovascular risk in MetS.
A Case of Chromosome 22q11 Deletion Syndrome Diagnosed in a 32-Year-Old Man with Hypoparathyroidism
Authors: Maalouf Naim M. , Sakhaee Khashayar , Odvina Clarita V. 
Published: October 2004

AbstractCongenital hypoparathyroidism typically manifests with hypocalcemia with or without associated characteristic physical findings and is usually diagnosed during the neonatal period. This report describes an African-American male who was diagnosed at age 32 yr to have dysgenesis of the parathyroid glands due to chromosome 22 microdeletion. Symptomatic hypocalcemia did not develop until age 14 yr, a few weeks after initiation of anticonvulsant therapy for generalized tonic-clonic seizures. Because of the timing for onset of symptomatic hypocalcemia, it was presumed that the patient had anticonvulsant-induced hypocalcemia, and he carried that diagnosis for 18 yr. Chromosome 22q11 deletion syndrome was first suspected at age 32 yr, based on the findings of subtle dysmorphic facial features and a history of learning disability in a patient with PTH-deficient hypocalcemia. The diagnosis was confirmed by fluorescence in situ hybridization analysis.This case underscores the variable clinical presentation of this congenital form of hypoparathyroidism. Chromosome 22q11 microdeletions are relatively common, and the diagnosis should be considered even in adults with hypoparathyroidism because of the potential benefit of genetic counseling.
Growth Hormone Treatment Improves Peripheral Muscle Oxygen Extraction-Utilization during Exercise in Patients with Human Immunodeficiency Virus-Associated Wasting: A Randomized Controlled Trial
Authors: Esposito John G. , Thomas Scott G. , Kingdon Lori , Ezzat Shereen 
Published: October 2004

Abstract
The arteriovenous oxygen difference (a-vO2 difference), a measure of peripheral muscle oxygen extraction-utilization during exercise, is reduced in antiretroviral-treated patients with human immunodeficiency virus (HIV), thus causing a shift in the cardiac output-oxygen consumption (Q-VO2) relationship. We investigated the impact of recombinant human GH (rhGH) treatment on a-vO2 difference and the Q-VO2 relationship during submaximal exercise by randomizing 12 HIV-infected patients (mean ± sem: age, 43.3 ± 1.5 yr; body mass, 69.5 ± 2.9 kg; body mass index, 22.4 ± 0.9 kg/m2; maximum oxygen consumption, 33.6 ± 1.5 ml/kg·min), with documented unintentional weight loss (≥10% within the preceding 12 months) despite antiretroviral therapy, to receive 3 months of rhGH (6 mg/d) in a double-blind, placebo-controlled, cross-over trial. We assessed Q (determined noninvasively using CO2 rebreathing), and subsequently a-vO2 difference, from Q-VO2 relationships. At study entry, the mean slope (8.1 ± 1.0 liters/min·1-liter increase in VO2) and intercept (3.1 ± 1.3 liters/min), generated from each patient’s Q-VO2 relationship, were greater and lower, respectively, than those reported for healthy individuals (6.0 and 4.0, respectively), thereby indicating a deficit in the a-vO2 difference. After 3 months of rhGH treatment, the slope decreased to 7.0, and the intercept increased to 3.5. After 1 month of rhGH treatment, the a-vO2 difference (at a VO2 of 1250 ml/min) significantly (P &lt; 0.05) increased (17.1 ± 8.9%) from baseline (9.92 ± 0.51 ml/dl) and remained elevated (10.39 ± 0.48 ml/dl) after 3 months of treatment. No significant changes were seen with placebo. Therefore, treatment with rhGH leads to an improvement in peripheral muscle oxygen extraction-utilization and the Q-VO2 relationship during exercise in patients with HIV-associated wasting despite antiretroviral therapy.
Gonadal Dysgenesis Without Adrenal Insufficiency in a 46, XY Patient Heterozygous for the Nonsense C16X Mutation: A Case of SF1 Haploinsufficiency
Authors: Mallet Delphine , Bretones Patricia , Michel-Calemard Laurence , Dijoud Frederique , David Michel , Morel Yves 
Published: October 2004

Abstract
Targeted disruption of the orphan nuclear receptor SF1 results in the absence of adrenals and gonads, establishing that this transcription factor is implicated in gonadal determination and adrenal development. Four human SF1 gene mutations have been described to date: three (G35E, R92Q, R255L) were responsible for adrenal insufficiency associated with a gonadal dysgenesis in two 46, XY individuals, one (8 bp deletion in exon 6) resulted in gonadal dysgenesis without adrenal insufficiency. We identified a new heterozygous SF1 gene mutation, C16X, in a 46, XY patient showing gonadal dysgenesis with normal adrenal function: low basal levels of AMH and testosterone (T), weak T response to hCG, hypoplastic testes with abundant seminiferous tubules but rare germ cells. This mutation causes premature termination of translation and should abolish all SF1 activity. Therefore haploinsufficiency could explain the deleterious effect of this mutation in our patient suggesting that testis development is more SF1 dose-dependant than adrenal development. Although the same mechanism explains the deleterious effects of SF1 missense mutations, recent studies have demonstrated an additional dominant negative effect. These data suggest that heterozygous mutation impaired adrenal development only if the two mechanisms, gene dosage and dominant negative effects occur.
Motor output characterizing thanatosis in the cricketGryllus bimaculatus
Authors: Nishino Hiroshi 
Published: October 2004

SUMMARYThe cricket Gryllus bimaculatus displays a sudden rigid immobility(thanatosis) when voluntary leg movements are forcibly restrained. The tibial joints in all legs are stiffly immobilized for several minutes. The flexed-leg posture typical of thanatosis is maintained by the flexor tibiae muscle. To characterize thanatosis at the motor output level, the mechanical and physiological properties of the metathoracic tibia muscle were investigated. The accessory flexor muscle, especially well-developed in the cricket, acts to stably maintain the tibial flexion driven by the main flexor muscle. Extracellular recordings from the flexor muscle of tethered crickets revealed that activity of intermediate- and fast-excitatory units was almost completely suppressed, while slow-excitatory units persisted in firing tonically during thanatosis. The firing rate of slow-excitatory units progressively increased as the tibia flexed, but remained less than the firing rate seen in the quiescent state. Common inhibitory motor neurones that fire sporadically in the quiescent state were suppressed during thanatosis, especially in the beginning, and showed a large excitation immediately after arousal. These findings suggest that the entire motor neuronal pool is held under active suppression during thanatosis, and that flexor muscle rigidity is maintained by a weak discharge of the slow exciters together with suppression of the inhibitors.
Characterization of the voltage-activated currents in cultured atrial myocytes isolated from the heart of the common oysterCrassostrea gigas
Authors: Pennec Jean-Pierre , Talarmin Hélène , Droguet Mikaël , Giroux-Metgès Marie-Agnès , Gioux Maxime , Dorange Germaine 
Published: October 2004

SUMMARYUsing the macro-patch clamp technique, we show that cardiac myocytes isolated from the heart of the oyster Crassostrea gigas possess several types of voltage-activated ionic currents. (1) A classical non-inactivating potassium current of the IK type that is inhibited by tetraethyl ammonium and shows an outward rectification and a slow activation. (2) A potassium current of the IA type that shows rapid activation and inactivation, and is blocked by 4-amino pyridine or preliminary depolarisation. (3) A potassium calcium-dependent current that is inhibited by charybdotoxin, activated by strong depolarisations and shows a large conductance. (4) A calcium inward current of the L-type that is inhibited by verapamil, cobalt and high concentrations of cadmium. This current is identified in most cells, but a T-type calcium current and classical fast sodium current are only identified in few cells, and only after a strong hyperpolarizing pulse. This suggests that these channels are normally inactivated in cultured cells and are not involved in the spontaneous activity of these cells. When they exist, the fast sodium channel is blocked by tetrodotoxin. The L-type calcium conductance is increased by serotonin. The identification in cultured oyster atrial cells of classical ionic currents,which are observed in most vertebrate species but only in a few species of molluscs, demonstrates that these cells are an interesting model. Moreover the viability and the electrophysiological properties of these cells are not significantly modified by freezing and thawing, thus increasing their usefulness in various bioassays.
Developmental changes in cardiorespiratory patterns associated with terrestrial apnoeas in harbour seal pups
Authors: Lapierre Jennifer L. , Schreer Jason F. , Burns Jennifer M. , Hammill Michael O. 
Published: October 2004

SUMMARYDuring the nursing period seals undergo several physiological and behavioural changes. A key component of development is increased cardiorespiratory control, fundamental for breath-holding and thus diving. This study focused on the ontogenetic changes in cardiac responses to respiration in quietly resting, pre-weaned harbour seal pups (Phoca vitulina). During periods of quiet rest, breathing became episodic,eupnoea interspersed with periods of apnoea. Little change was observed in respiration (∼35 breaths min–1) and eupnoeic heart rate(∼160 beats min–1) throughout the nursing period. However, apnoea duration increased (from ∼20 to 40 s), while apnoeic heart rate decreased with age (from ∼150 to 90 beats min–1). The observed decline in apnoeic heart rate resulted from an increase in cardiorespiratory control as pups approached weaning, evident by the ability to maintain a lower heart rate more consistently. Similar changes in cardiorespiratory patterns have been reported for elephant and Weddell seals. Due to the early onset of independent foraging, however, the rate of cardiorespiratory control development was more rapid in harbour seals. Our findings suggest that by 1 month of age, harbour seal pups possess the cardiorespiratory control necessary to sustain long-duration apnoeas,fundamental for proficient diving and successful foraging upon weaning.
Acclimatization to 4100 m does not change capillary density or mRNA expression of potential angiogenesis regulatory factors in human skeletal muscle
Authors: Lundby Carsten , Pilegaard Henriette , Andersen Jesper L. , van Hall Gerrit , Sander Mikael , Calbet Jose A. L. 
Published: October 2004

SUMMARYIncreased skeletal muscle capillary density would be a logical adaptive mechanism to chronic hypoxic exposure. However, animal studies have yielded conflicting results, and human studies are sparse. Neoformation of capillaries is dependent on endothelial growth factors such as vascular endothelial growth factor (VEGF), a known target gene for hypoxia inducible factor 1 (HIF-1). We hypothesised that prolonged exposure to high altitude increases muscle capillary density and that this can be explained by an enhanced HIF-1αexpression inducing an increase in VEGF expression. We measured mRNA levels and capillary density in muscle biopsies from vastus lateralis obtained in sea level residents (SLR; N=8) before and after 2 and 8 weeks of exposure to 4100 m altitude and in Bolivian Aymara high-altitude natives exposed to approximately 4100 m altitude (HAN; N=7). The expression of HIF-1α or VEGF mRNA was not changed with prolonged hypoxic exposure in SLR, and both genes were similarly expressed in SLR and HAN. In SLR, whole body mass, mean muscle fibre area and capillary to muscle fibre ratio remained unchanged during acclimatization. The capillary to fibre ratio was lower in HAN than in SLR (2.4±0.1 vs 3.6±0.2; P&lt;0.05). In conclusion, human muscle VEGF mRNA expression and capillary density are not significantly increased by 8 weeks of exposure to high altitude and are not increased in Aymara high-altitude natives compared with sea level residents.