bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of a Locus Increasing Rice Yield and Physiological Analysis of Its Function
Authors: Ishimaru Ken
Published: November 2003

I identified a new locus responsible for increased yield potential and evaluated its physiological function to understand how to improve potential yield in rice (Oryza sativa) plants. Quantitative trait loci (QTLs) for 1,000-grain weight (TGW) were analyzed under different environments over 3 years in backcross inbred lines of rice japonica cv Nipponbare × indica cv Kasalath. Four QTLs for this trait were detected across environments; rice cv Kasalath had a positive allele only at one QTL on chromosome 6 (tgw6). A near-isogenic line (NILtgw6) that carried a rice cv Kasalath chromosomal segment corresponding to tgw6 in the rice cv Nipponbare genetic background was selected and analyzed to clarify the physiological function of this locus. The carbohydrate storage capacity before heading in NILtgw6 was superior to that in rice cv Nipponbare (control), but other characters (e.g. photosynthetic ability in flag leaf and traits related to plant type) were the same in both plants. In the leaf sheath, the main organ that accumulates carbohydrate before heading in rice, higher contents of carbohydrate and transcripts of genes related to starch synthesis were found in NILtgw6 than in rice cv Nipponbare. Compared with those in rice cv Nipponbare, a high-yield modern cultivar, TGW and yield per plant were significantly higher in NILtgw6, by 10% and 15%, respectively (P[f] < 0.01). These results suggest that tgw6 improves the carbohydrate storage capacity and consequently increases the yield potential in NILtgw6.
Resorption Protection. Anthocyanins Facilitate Nutrient Recovery in Autumn by Shielding Leaves from Potentially Damaging Light Levels
Authors: Hoch William A. , Singsaas Eric L. , McCown Brent H.
Published: November 2003

The resorption protection hypothesis, which states that anthocyanins protect foliar nutrient resorption during senescence by shielding photosynthetic tissues from excess light, was tested using wild-type (WT) and anthocyanin-deficient mutants of three deciduous woody species, Cornus sericea, Vaccinium elliottii (Chapmn.), and Viburnum sargentii (Koehne). WT Betula papyrifera (Marsh) was included to compare the senescence performance of a species that does not produce anthocyanins in autumn. Plants were subjected to three environmental regimes during senescence: an outdoor treatment; a 5-d high-stress (high light and low temperature) treatment followed by transfer to a low-stress environment and a low-stress treatment that served as control. In the outdoor treatment, the appearance of anthocyanins in senescing leaves of WT plants was concomitant with the development of photo-inhibition in mutant plants of all three anthocyanin-producing species. In the high-stress environment, WT plants maintained higher photochemical efficiencies than mutants and were able to recover when transferred to the low-stress environment, whereas mutant leaves dropped while still green and displayed signs of irreversible photooxidative damage. Nitrogen resorption efficiencies and proficiencies of all mutants in both stressful treatments were significantly lower than the WT counterparts. B. papyrifera displayed photochemical efficiencies and nitrogen resorption performance comparable with the highest of the anthocyanin-producing species in all three senescing environments, indicating a photoprotective strategy divergent from the other species studied. These results strongly support the resorption protection hypothesis of anthocyanins in senescing leaves.
eEF1A Isoforms Change in Abundance and Actin-Binding Activity during Maize Endosperm Development
Authors: Lopez-Valenzuela Jose A. , Gibbon Bryan C. , Hughes Peter A. , Dreher Theo W. , Larkins Brian A.
Published: November 2003

Eukaryotic elongation factor 1A (eEF1A) appears to be a multifunctional protein because several biochemical activities have been described for this protein, in addition to its role in protein synthesis. In maize (Zea mays) endosperm, the synthesis of eEF1A is increased in o2 (opaque2) mutants, and its concentration is highly correlated with the protein-bound lysine content. To understand the basis of this relationship, we purified eEF1A isoforms from developing endosperm and investigated their accumulation and their functional and structural properties. Formation of three isoforms appears to be developmentally regulated and independent of the o2 mutation, although one isoform predominated in one high lysine o2 inbred. The purified proteins differ in their ability to bind F-actin in vitro, suggesting that they are functionally distinct. However, they share similar aminoacyl-tRNA-binding activities. Tandem mass spectrometry revealed that each isoform is composed of the four same gene products, which are modified posttranslationally by methylation and phosphorylation. The chemical differences that account for their different actin-binding activities could not be determined.
What Affects mRNA Levels in Leaves of Field-Grown Aspen? A Study of Developmental and Environmental Influences
Authors: Wissel Kirsten , Pettersson Fredrik , Berglund Anders , Jansson Stefan
Published: November 2003

We have analyzed the abundance of mRNAs expressed from 11 nuclear genes in leaves of a free-growing aspen (Populus tremula) tree throughout the growing season. We used multivariate statistics to determine the influence of environmental factors (i.e. the weather before sampling) and developmental responses to seasonal changes at the mRNA level for each of these genes. The gene encoding a germin-like protein was only expressed early in the season, whereas the other tested genes were expressed throughout the season and showed mRNA variations on a day-to-day basis. For six of the genes, reliable models were found that described the mRNA level as a function of weather, but the leaf age was also important for all genes except one encoding an early light-inducible protein (which appeared to be regulated purely by environmental factors under these conditions). The results confirmed the importance of several environmental factors previously shown to regulate the genes, but we also detected a number of less obvious factors (such as the variation in weather parameters and the weather of the previous day) that correlated with the mRNA levels of individual genes. The study shows the power of multivariate statistical methods in analyzing gene regulation under field conditions.
Multiple Hormones Act Sequentially to Mediate a Susceptible Tomato Pathogen Defense Response
Authors: O'Donnell Philip J. , Schmelz Eric , Block Anna , Miersch Otto , Wasternack Claus , Jones Jeffrey B. , Klee Harry J.
Published: November 2003

Phytohormones regulate plant responses to a wide range of biotic and abiotic stresses. How a limited number of hormones differentially mediate individual stress responses is not understood. We have used one such response, the compatible interaction of tomato (Lycopersicon esculentum) and Xanthomonas campestris pv vesicatoria (Xcv), to examine the interactions of jasmonic acid (JA), ethylene, and salicylic acid (SA). The role of JA was assessed using an antisense allene oxide cyclase transgenic line and the def1 mutant to suppress Xcv-induced biosynthesis of jasmonates. Xcv growth was limited in these lines as was subsequent disease symptom development. No increase in JA was detected before the onset of terminal necrosis. The lack of a detectable increase in JA may indicate that an oxylipin other than JA regulates basal resistance and symptom proliferation. Alternatively, there may be an increase in sensitivity to JA or related compounds following infection. Hormone measurements showed that the oxylipin signal must precede subsequent increases in ethylene and SA accumulation. Tomato thus actively regulates the Xcv-induced disease response via the sequential action of at least three hormones, promoting expansive cell death of its own tissue. This sequential action of jasmonate, ethylene, and SA in disease symptom development is different from the hormone interactions observed in many other plant-pathogen interactions.
pH modulation of currents that contribute to the medium and slow afterhyperpolarizations in rat CA1 pyramidal neurones
Authors: Kelly Tony , Church John
Published: November 2003

We examined the effects of changes in pHoand pHion currents contributing to the medium and slow afterhyperpolarizations (mIAHPand sIAHP, respectively) in rat CA1 neurones. Reducing pHofrom 7.4 to 6.7 inhibited mIAHPand sIAHPwhereas increasing pHoto 7.7 augmented mIAHPand, to a greater extent, sIAHP. The ability of changes in pHoto modulate mIAHPreflected changes in the Ca2+‐activated K+current,IAHP, and a Co2+‐ and XE991‐resistant component of mIAHP, but not the muscarine‐sensitive current,IM. In the presence of 1 μmTTX and 5 mmTEA, low pHo‐evoked reductions in sIAHPwere associated with reductions in Ca2+‐dependent depolarizing potentials; because neither effect was attenuated when internal H+buffering power was raised by including 100 mmtricine in the patch pipette, the actions of reductions in pHoto inhibit sIAHPand, possibly,IAHPin large part appear to reflect a low pHo‐dependent decrease in Ca2+influx. In contrast, the effects of high pHoto augment mIAHPand sIAHPwere associated with relatively small increases in Ca2+potentials but were significantly attenuated by 100 mminternal tricine, indicating that a rise in pHiconsequent upon the rise in pHowas largely responsible. The possibility that changes in pHicould act to modulate mIAHPand sIAHP, independently of changes in Ca2+influx, was also suggested by experiments in which pHiwas lowered at a constant pHoby the external application of propionate or by the withdrawal of HCO−3from the perfusing medium. Lowering pHiat a constant pHohad little effect on Ca2+potentials but inhibited mIAHPand, to a greater extent, sIAHP, effects that were attenuated by 100 mminternal tricine. Together, the results indicate that changes in pHoand pHimodulate mIAHPand sIAHPin rat CA1 neurones and suggest that, depending on the direction of the pHochange, the sensitivities of the underlying currents to changes in Ca2+influx and/or pHimay contribute to the effects of changes in pHoto modulate mIAHPand sIAHP.
Measuring spike coding in the rat supraoptic nucleus
Authors: Bhumbra G. S. , Dyball R. E. J.
Published: November 2003

Measuring spike coding objectively is essential to establish whether activity recorded under one set of conditions is truly different from that recorded under another set of conditions. However, there is no generally accepted method for making such comparisons. Measuring firing frequency alone only partially reflects spike patterning. In this paper, novel quantities based on the logarithmic interspike intervals are proposed as useful measures of spontaneous activity. We illustrate the methods by comparing extracellular recordings from magnocellular cells of the rat supraoptic nucleus in vivo and in vitro and between oxytocin and vasopressin cells in vivo. A bimodal Gaussian function fitted to the log interspike interval histogram accurately described the distribution profile for very different types of activity. We introduce the entropy of the log interval distribution as a novel quantity that measures the capacity of a cell to encode information other than a constant instantaneous frequency. Unlike existing entropy measures that are based on spike counts, it quantifies the variability in the interval distribution. In addition, the mutual information between adjacent log intervals is proposed as an objective measure of patterned activity. For cells recorded in vivo and in vitro, there was no significant difference in mean spike frequencies but there were differences in the log interval entropy (t=–4.97, P < 0.001) and the mutual information (z=–2.64, P < 0.01). The differences may result from the disruption of connections in the slice preparation. When a comparison was made between the spike activity of oxytocin and vasopressin cells recorded in vivo, there was a difference in mutual information (z= 5.15, P < 0.001) but not in mean spike frequency. Both comparisons highlight the potential limitations of using mean spike frequency alone as a measure of spike coding. We propose that our novel parameters based on interval analysis constitute informative measures of spontaneous activity under different physiological conditions.
Inactivation and recovery in Kv1.4 K+ channels: lipophilic interactions at the intracellular mouth of the pore
Authors: Bett Glenna C. L. , Rasmusson Randall L.
Published: November 2003

C‐type inactivation is present in many voltage‐gated potassium channels and is probably related to ‘slow’ inactivation in calcium and sodium channels. The mechanisms underlying C‐type inactivation are unclear, but it is sensitive to mutations on both the extra‐ and intracellular sides of the channel. We used an N‐terminal deleted channel with a valine to alanine point mutation at the intracellular side of S6 (fKv1.4[V561A]ΔN). This construct alters recovery from inactivation and inverts the relationship between C‐type inactivation and [K+]o. We used this inverted relationship to examine C‐type inactivation and coupling mechanisms between N‐ and C‐type inactivation. The valine to alanine mutation reduces the channel's affinity for both quinidine and the N‐terminal domain. However, binding of the N‐terminal or quinidine restores normal recovery from inactivation. This suggests that coupling between N‐ and C‐type inactivation is dominated by allosteric mechanisms. The permeation mechanism, driven by a reduction in permeant [K+]o following pore block (which would retard C‐type inactivation), contributes minimally to coupling in these channels. We propose that the cytoplasmic half of S6 forms part of the N‐terminal binding site, as previously predicted from X‐ray crystallography studies in the distantly related KcsA channel. Binding of the N‐terminal domain or a positively charged lipophilic compound such as quinidine interacts with the hydrophobic moieties on S6 in the bound state. This binding can orientate S6 into a conformation which resembles the normal C‐type inactivated state. This is the probable mechanism by which drug or N‐terminal binding increases the rate of C‐type inactivation via an allosteric mechanism.
A reduced cerebral metabolic ratio in exercise reflects metabolism and not accumulation of lactate within the human brain
Authors: Dalsgaard Mads K. , Quistorff Bjørn , Danielsen Else R. , Selmer Christian , Vogelsang Thomas , Secher Niels H.
Published: November 2003

During maximal exercise lactate taken up by the human brain contributes to reduce the cerebral metabolic ratio, O2/(glucose + 1/2 lactate), but it is not known whether the lactate is metabolized or if it accumulates in a distribution volume. In one experiment the cerebral arterio‐venous differences (AV) for O2, glucose (glc) and lactate (lac) were evaluated in nine healthy subjects at rest and during and after exercise to exhaustion. The cerebrospinal fluid (CSF) was drained through a lumbar puncture immediately after exercise, while control values were obtained from six other healthy young subjects. In a second experiment magnetic resonance spectroscopy (1H‐MRS) was performed after exhaustive exercise to assess lactate levels in the brain (n = 5). Exercise increased the AVO2 from 3.2 ± 0.1 at rest to 3.5 ± 0.2 mm (mean ±s.e.m.; P < 0.05) and the AVglc from 0.6 ± 0.0 to 0.9 ± 0.1 mm (P < 0.01). Notably, the AVlac increased from 0.0 ± 0.0 to 1.3 ± 0.2 mm at the point of exhaustion (P < 0.01). Thus, maximal exercise reduced the cerebral metabolic ratio from 6.0 ± 0.3 to 2.8 ± 0.2 (P < 0.05) and it remained low during the early recovery. Despite this, the CSF concentration of lactate postexercise (1.2 ± 0.1 mm; n= 7) was not different from baseline (1.4 ± 0.1 mm; n= 6). Also, the 1H‐MRS signal from lactate obtained after exercise was smaller than the estimated detection limit of ∼1.5 mm. The finding that an increase in lactate could not be detected in the CSF or within the brain rules out accumulation in a distribution volume and indicates that the lactate taken up by the brain is metabolized.
Separase Regulates INCENP-Aurora B Anaphase Spindle Function Through Cdc14
Authors: Pereira Gislene , Schiebel Elmar
Published: November 2003

The inner centromere-like protein (INCENP) forms a complex with the evolutionarily conserved family of Aurora Bkinases. The INCENP-Aurora complex helps coordinate chromosome segregation, spindle behavior, and cytokinesis during mitosis. INCENP-Aurora associates with kinetochores in metaphase and with spindle microtubules in anaphase, yet the trigger for this abrupt transfer is unknown. Here we show that the conserved phosphatase Cdc14 regulated the yeast INCENP-Aurora complex, Sli15-Ipl1. Cdc14 dephosphorylated Sli15 and thereby directed the complex to spindles. Activation of Cdc14 by separase was sufficient for Sli15 dephosphorylation and relocalization. Cdc14 not only regulates mitotic exit but also modulates spindle midzone assembly through Sli15-Ipl1.
Serous effusions: diagnosis of malignancy beyond cytomorphology. An analytic review
Authors: Mohanty S K , Dey P
Published: November 2003

In this brief review, the role of various ancillary techniques to detect malignancy in effusion fluid are evaluated and discussed. The data were collected from a large number of research articles published in various medical journals. The role of these techniques to increase the diagnostic accuracy in serous effusions is emphasised.
“Osler’s phenomenon”: misdiagnosing Cushing’s syndrome
Authors: De P , Evans L M , Scanlon M F , Davies J S
Published: November 2003

The clinical manifestations of Cushing’s syndrome can be quite variable and are frequently mistaken, with consequent delayed diagnosis and significant morbidity and mortality. Harvey Cushing described the typical signs and symptoms of Cushing’s syndrome but unfortunately attributed the features to myxoedema. The first typical description of a patient with Cushing’s syndrome was probably made by Sir William Osler in 1898. Thus delay or misdiagnosis with consequent high morbidity and mortality exemplifies the history of Cushing’s syndrome.

Four cases of Cushing’s syndrome are described that were associated with deteriorating morbidity because of the considerable delay from first presentation to a secondary care physician to eventual diagnosis. The clinical diagnosis was delayed in all the four patients, although they had symptoms and signs that were missed by a number of primary and secondary care physicians. Trans-sphenoidal surgery resulted in biochemical cure as well as improvement in the accompanying co-morbidity.

Although still rare, the prevalence of Cushing’s syndrome is increasing. Increasing clinical awareness and the use of appropriate screening tests should facilitate earlier diagnosis with reduced morbidity and mortality. Although the syndrome is named after Harvey Cushing, Sir William Osler was probably the first to describe it. Therefore, in deference to Osler’s contribution to Cushing’s syndrome and the work of Harvey Cushing, it is suggested that to the list of the other eponymous conditions of Osler-Weber-Rendu and Osler’s nodes, should be added the delay or misdiagnosis of Cushing’s syndrome—“Osler’s phenomenon”.
Detection, Management, and Prospects for the Medical Treatment of Small Abdominal Aortic Aneurysms
Authors: Powell Janet T. , Brady Anthony R.
Published: November 2003

Small abdominal aortic aneurysms, up to 5.5 cm in diameter, are very common. Ultrasonography is the most cost-effective method of detecting these aneurysms and keeping them under surveillance, because the natural history is 1 of continued expansion. The expansion rate is in the range 0.25 to 0.35 cm/y and is fastest in current smokers. From a study of expansion rates, it has been possible to formulate guidelines for the intervals at which surveillance should occur. Although the evidence from randomized trials indicates that early, open, elective surgery for small aneurysms does not save lives, when aneurysms exceed 5.5 cm in diameter, either open or endovascular surgery is recommended. To prevent small aneurysms reaching the 5.5-cm threshold, new treatments to reduce the expansion rate by >50% need to be designed, based on the underlying pathologic processes: proteolysis and inflammation. Any proposed treatments, including statins, will need to be tested in clinical trials.
Atrophic Remodeling of the Heart In Vivo Simultaneously Activates Pathways of Protein Synthesis and Degradation
Authors: Razeghi Peter , Sharma Saumya , Ying Jun , Li Yi-Ping , Stepkowski Stanislaw , Reid Michael B. , Taegtmeyer Heinrich
Published: November 2003

Background—

Mechanical unloading of the heart results in atrophic remodeling. In skeletal muscle, atrophy is associated with inactivation of the mammalian target of rapamycin (mTOR) pathway and upregulation of critical components of the ubiquitin proteosome proteolytic (UPP) pathway. The hypothesis is that mechanical unloading of the mammalian heart has differential effects on pathways of protein synthesis and degradation.

Methods and Results—

In a model of atrophic remodeling induced by heterotopic transplantation of the rat heart, we measured gene transcription, protein expression, polyubiquitin content, and regulators of the mTOR pathway at 2, 4, 7, and 28 days. In atrophic hearts, there was an increase in polyubiquitin content that peaked at 7 days and decreased by 28 days. Furthermore, gene and protein expression of UbcH2, a ubiquitin conjugating enzyme, was also increased early in the course of unloading. Transcript levels of TNF-α, a known regulator of UbcH2-dependent ubiquitin conjugating activity, were upregulated early and transiently in the atrophying rat heart. Unexpectedly, p70S6K and 4EBP1, downstream components of mTOR, were activated in atrophic rat heart. This activation was independent of Akt, a known upstream regulator of mTOR. Rapamycin treatment of the unloaded rat hearts inhibited the activation of p70S6K and 4EBP1 and subsequently augmented atrophy in these hearts compared with vehicle-treated, unloaded hearts.

Conclusions—

Atrophy of the heart, secondary to mechanical unloading, is associated with early activation of the UPP. The simultaneous activation of the mTOR pathway suggests active remodeling, involving both protein synthesis and degradation.
Effect of Atrial Fibrillation on Hematopoietic Progenitor Cells
Authors: Goette Andreas , Jentsch-Ullrich Kathleen , Lendeckel Uwe , Röcken Christoph , Agbaria Mahmood , Auricchio Angelo , Mohren Martin , Franke Astrid , Klein Helmut U.
Published: November 2003

Background—

Injury to the heart causes hematopoietic progenitor cells (HPCs) to migrate to the site of damage and to undergo cell differentiation. Studies suggest that myocardial progenitor cells invade atrial tissue. So far it is unclear, however, whether an atrial disease per se affects circulating HPCs.

Methods and Results—

Seventeen patients with persistent atrial fibrillation (persistAF), 12 with paroxysmal AF (paroxAF), and 17 matched patients with sinus rhythm (SR) were studied. HPCs (CD34
+
and CD34
+
/CD117
+
) were quantified with the use of a fluorescence-activated cell sorter; stromal cell–derived factor-1α (SDF-1α), vascular endothelium growth factor (VEGF), and atrial natriuretic peptide (ANP) were determined by immunoassays. In patients with persistAF, blood samples were obtained before as well as 10 minutes, 24 hours, and 48 hours after electrical cardioversion. CD34
+
HPCs (AF, 7.0±2.3×103/mL versus SR, 5.0±1.6×10
3
/mL;
P
<0.01) were increased during persistAF only. Highest SDF-1α levels were also observed during persistAF. Successful and unsuccessful cardioversion decreased CD34
+
HPCs temporarily (7.0±2.3×10
3
/mL versus 24 hours: 5.0±1.5×10
3
/mL;
P
<0.05). Forty-eight hours after successful cardioversion, SDF-1α and CD34
+
HPC levels started to decline, reaching control levels after 59±19 days. CD34
+
/CD117
+
and VEGF levels, however, were increased by DC energy but not by AF. ANP levels correlated with CD34
+
HPC (
r
=0.76;
P
<0.01) and SDF-1α (
r
=0.56;
P
<0.01). HPCs from patients with AF had a greater tendency to differentiate into cells expressing (cardio)myocyte markers ANP and myocyte enhancer factor-2.

Conclusions—

PersistAF appears to increase the potential of HPCs for (cardio)myogenesis. Restitution of CD34
+
HPC levels, mediated by SDF-1α and possibly ANP, occurs within several weeks after successful cardioversion.
Cost-Effectiveness of Coronary Stenting and Abciximab for Patients With Acute Myocardial Infarction
Authors: Bakhai Ameet , Stone Gregg W. , Grines Cindy L. , Murphy Sabina A. , Githiora Louise , Berezin Ronna H. , Cox David A. , Stuckey Thomas , Griffin John J. , Tcheng James E. , Cohen David J.
Published: November 2003

Background—

Both stenting and the glycoprotein IIb/IIIa inhibitor abciximab improve outcomes for patients undergoing primary angioplasty for acute myocardial infarction (AMI). However, the cost-effectiveness of these strategies is unknown.

Methods and Results—

We performed a prospective cost-utility analysis among US participants in the CADILLAC trial. Patients with AMI (n=1703) were randomized to stenting versus balloon angioplasty (PTCA) and abciximab versus no abciximab according to a 2-by-2 factorial design. Total 1-year costs and lifetime incremental cost-effectiveness ratios, measured as cost per quality-adjusted year of life (QALY) gained, were calculated. Compared with PTCA, stenting increased procedural costs by $1148 and initial hospital costs by $1384 (both
P
<0.001). By 1-year, stenting led to fewer repeat revascularization procedures and reduced follow-up medical care costs by $1215, such that aggregate costs were similar for the PTCA and stent groups ($18 690 versus $18 859,
P
=0.75). The cost-effectiveness ratio for stenting versus PTCA was favorable at $11 237/QALY gained and remained <$20 000/QALY in sensitivity analyses. Compared with standard anticoagulation, abciximab increased initial procedural costs by $1122 (
P
<0.001). By facilitating accelerated hospital discharge, abciximab reduced length of stay by ≈0.6 days, offsetting most of the drug costs. These cost offsets were not maintained, however; aggregate 1-year costs for the abciximab group were $1244 greater than for standard therapy ($19 389 versus $18 145,
P
=0.02). Abciximab was reasonably cost-effective (cost-effectiveness ratio $21 305/QALY) only if nonsignificant differences in 1-year mortality (3.7% versus 4.3%,
P
=0.62) were incorporated in the analysis.

Conclusions—

Primary stenting is a highly cost-effective treatment for AMI. The cost-effectiveness of abciximab in this setting is uncertain and depends primarily on whether long-term survival is enhanced.
Postovariectomy Hypertension Is Linked to Increased Renal AT
1
Receptor and Salt Sensitivity
Authors: Harrison-Bernard Lisa M. , Schulman Ivonne Hernandez , Raij Leopoldo
Published: November 2003

The functional balance between angiotensin II (Ang II) and nitric oxide (NO) plays a key role in modulating salt sensitivity. Estrogen has been shown to downregulate angiotensin type 1 (AT
1
) receptor expression and to increase the bioavailability of endothelium-derived NO, which decreases AT
1
receptor expression. The present study tests the hypothesis that in the presence of genetic salt sensitivity, deficiency of endogenous estrogens after ovariectomy (OVX) fosters an upregulation of Ang II. Female Dahl salt-resistant (DR), Dahl salt-sensitive (DS), Wistar-Kyoto (WKY), and spontaneously hypertensive (SHR) rats underwent bilateral OVX or sham surgery (SHX) and were fed a normal salt diet (0.5% NaCl) for 14 weeks. Systolic blood pressures were measured every 2 weeks and were not significantly different between OVX and SHX for DR, WKY, and SHR groups. However, at the end of 14 weeks of normal salt diet, hypertension developed in DS OVX but not SHX rats (160±3 versus 136±3 mm Hg;
P
<0.05). Hypertension also developed in DS OVX rats pair-fed a normal salt diet (166±7 mm Hg). Development of hypertension in DS OVX rats was prevented by estrogen replacement (132±3 mm Hg), AT
1
receptor blockade (119±3 mm Hg), or feeding a very low salt diet (0.1% NaCl; 129±4 mm Hg). Renal AT
1
receptor protein expression was significantly elevated 2-fold in DS OVX relative to SHX rats and was prevented by estrogen replacement. These data strongly suggest that after OVX in salt-sensitive rats there is a lower threshold for the hypertensinogenic effect of salt that is linked to an activation of Ang II.
Protein Kinase Cα Negatively Regulates Systolic and Diastolic Function in Pathological Hypertrophy
Authors: Hahn Harvey S. , Marreez Yehia , Odley Amy , Sterbling Amber , Yussman Martin G. , Hilty K. Chad , Bodi Ilona , Liggett Stephen B. , Schwartz Arnold , Dorn Gerald W.
Published: November 2003

The protein kinase C (PKC) family is implicated in cardiac hypertrophy, contractile failure, and β-adrenergic receptor (βAR) dysfunction. Herein, we describe the effects of gain- and loss-of-PKCα function using transgenic expression of conventional PKC isoform translocation modifiers. In contrast to previously studied PKC isoforms, activation of PKCα failed to induce cardiac hypertrophy, but instead caused βAR insensitivity and ventricular dysfunction. PKCα inhibition had opposite effects. Because PKCα is upregulated in human and experimental cardiac hypertrophy and failure, its effects were also assessed in the context of the Gαq overexpression model (in which PKCα is transcriptionally upregulated). Normalization (inhibition) of PKCα activity in Gαq hearts improved systolic and diastolic function, whereas further activation of PKCα caused a lethal restrictive cardiomyopathy with marked interstitial fibrosis. These results define pathological roles for PKCα as a negative regulator of ventricular systolic and diastolic function.
Determination of Etiologic Mechanisms of Strokes Secondary to Coronary Artery Bypass Graft Surgery
Authors: Likosky Donald S. , Marrin Charles A.S. , Caplan Louis R. , Baribeau Yvon R. , Morton Jeremy R. , Weintraub Ronald M. , Hartman Gregg S. , Hernandez Felix , Braff Steven P. , Charlesworth David C. , Malenka David J. , Ross Cathy S. , O’Connor Gerald T.
Published: November 2003

Background and Purpose—

Current research focused on stroke in the setting of coronary artery bypass graft (CABG) surgery has missed important opportunities for additional understanding by failing to consider the range of different stroke mechanisms. We developed and implemented a classification system to identify the distribution and timing of stroke subtypes.

Methods—

We conducted a regional study of 388 patients with the diagnosis of stroke after isolated CABG surgery in northern New England from 1992 to 2000. Data were collected on patient and disease characteristics, intraoperative and postoperative care, and outcomes. Stroke etiology was classified into 1 of the following: hemorrhage, thromboembolic (embolic, thrombotic, lacunar), hypoperfusion, other (subtype not listed above), multiple (≥2 competing mechanisms), or unclassified (unknown mechanism). The reliability of the classification system was determined by percent agreement and κ statistics.

Results—

Embolic strokes accounted for 62.1% of strokes, followed by multiple etiologies (10.1%), hypoperfusion (8.8%), lacunar (3.1%), thrombotic (1.0%), and hemorrhage (1.0%). There were 54 strokes with unknown etiology (13.9%). There were no strokes classified as “other.” Nearly 45% (105/235) of the embolic and 56% (18/32) of hypoperfusion strokes occurred within the first postoperative day.

Conclusions—

We used a locally developed classification system to determine the etiologic mechanism of 388 strokes secondary to CABG surgery. The principal etiologic mechanism was embolic, followed by stroke having multiple mechanisms and hypoperfusion. Regardless of mechanism, strokes predominantly occurred within the first postoperative day.
Endovascular Treatment of Intracranial Aneurysms With Radioactive Coils
Authors: Raymond Jean , Roy Daniel , Leblanc Philippe , Roorda Sjoerd , Janicki Christian , Normandeau Lysanne , Morel François , Gevry Guylaine , Bahary Jean-Paul , Chagnon Miguel , Guilbert François , Weill Alain
Published: November 2003

Background and Purpose—

Endovascular treatment of intracranial aneurysms is safe and effective but is associated with angiographic recurrences. Beta radiation prevents recanalization after coil embolization in experimental models. We wanted to assess the feasibility of using radioactive coil embolization to improve long-term results of endovascular treatment.

Methods—

Platinum coils were ion-implanted with 0.13 to 0.26 μCi/cm of
32
P. Forty-one patients aged 34 to 84 years with 44 aneurysms with a high propensity for recurrences were included. Radioactive coils were introduced into aneurysms to reach a target volumetric activity of 0.018 μCi/mm
3
. Nonradioactive coils were also used to ensure the same safety and the same angiographic results as the standard procedure. Angiographic results, procedure-related complications, and neurological events during follow-up were recorded. Angiographic follow-up data are available in 36 lesions 6 months after treatment.

Results—

Forty of 44 aneurysms (91%) could be treated with radioactive coils. Target activities could be reached in 88% of lesions that could actually be coiled (35/40). Total activities ranged from 1.72 to 80.9 μCi, for a mean of 20.13±20.80 μCi. Procedure-related complications occurred in 7% of patients. Initial angiographic results were satisfactory (complete occlusions or residual necks) in 75% of lesions. Angiographic recurrences occurred in 11 (31%) of patients followed, within the expected range for standard coils. There was no complication from beta radiation during a mean follow-up period of 10 months.

Conclusions—

Radioactive coil embolization is feasible; target volumetric activities can be reached in most aneurysms considered for endovascular treatment.
Repeated Screening for Intracranial Aneurysms in Familial Subarachnoid Hemorrhage
Authors: Wermer Marieke J.H. , Rinkel Gabriël J.E. , van Gijn Jan
Published: November 2003

Background and Purpose—

In families with ≥2 first-degree relatives with subarachnoid hemorrhage (SAH), screening for aneurysms is often recommended. The benefit of repeated screening and the interval at which screening should be performed are unknown. We studied patient compliance and the yield of repeated screening for familial intracranial aneurysms.

Methods—

Relatives with familial SAH screened between 1990 and 1997 were advised to return every 5 years for follow-up screening with MR angiography. If neurosurgical clipping had been performed in the past, screening was done with CT angiography. We analyzed the results for the group as a whole and for the subgroups of relatives with and without previous aneurysms.

Results—

Of 129 relatives who were advised to undergo further screening, 27 did not return, 74 had 1 repeated screening, and 28 had a second repeated screening. We detected 10 new aneurysms in 9 of the 102 screened relatives (9%), 3 of the 19 relatives with previous aneurysms (16%), and 6 of the 83 relatives without previous aneurysms (7%). One of the 9 subjects with a new aneurysm and 1 other relative had an SAH 3 years after a negative screening procedure.

Conclusions—

In persons with familial occurrence of aneurysms, the motivation for repeated screening every 5 years is high and the yield is considerable, particularly in relatives who have been treated for aneurysms in the past. The occurrence of SAH <5 years after a negative screen suggests that screening may have to be repeated at shorter intervals.
Temporal Alterations in Cerebrospinal Fluid Amyloid β-Protein and Apolipoprotein E After Subarachnoid Hemorrhage
Authors: Kay Andrew , Petzold Axel , Kerr Mary , Keir Geoff , Thompson Ed , Nicoll James
Published: November 2003

Background and Purpose—

The mechanism underlying the association between possession of the
APOE
ε4 allele and less favorable outcome after subarachnoid hemorrhage (SAH) remains to be determined. After SAH the level of apolipoprotein E (apoE) in the cerebrospinal fluid (CSF) is decreased, and lower levels are associated with more severe injury and less favorable outcome. This study examined serial CSF samples to determine the time course for the decrease in CSF apoE and the relationship between CSF apoE and amyloid β-protein (Aβ), testing the hypothesis that apoE-Aβ interactions occur in vivo after SAH.

Methods—

Enzyme-linked immunosorbent assay was used to assay apoE, Aβ
1–40
, and Aβ
1–42
in serial ventricular CSF samples from 19 patients with SAH and 13 controls. CSF S100B and τ were assayed as surrogate markers of brain injury.

Results—

There was a sustained decrease in CSF apoE (
P
<0.001) and Aβ (
P
<0.001) after SAH in contrast to the observed elevation in CSF S100B (
P
<0.001) and τ (
P
<0.001) concentration. There was significant correlation between CSF Aβ concentration and clinical outcome (
r
=0.65,
P
<0.01), and the decrease in CSF Aβ concentration correlated significantly with that of apoE (
r
=0.85,
P
<0.0001).

Conclusions—

After SAH both apoE and Aβ levels decrease in the CSF, supporting the concept that interactions between these proteins occur in vivo. The possibility that apoE and Aβ influence outcome after SAH warrants further investigation.
Tissue Plasminogen Activator for Acute Ischemic Stroke in Clinical Practice
Authors: Graham Glenn D.
Published: November 2003

Background and Purpose—

Concerns persist regarding the safety of tissue plasminogen activator (tPA) therapy for acute ischemic stroke. Numerous case series of clinical experience with tPA have been published that provide additional data on the safety of thrombolytic therapy.

Methods—

This is a meta-analysis of 15 published, open-label studies that broadly followed approved indications and guidelines for tPA use in nonselective patient populations.

Results—

In 2639 treated patients, the symptomatic intracerebral hemorrhage rate was 5.2% (95% confidence interval, 4.3 to 6.0), slightly lower than the 6.4% rate in the treated group of the randomized, placebo-controlled National Institute of Neurological Disorders and Stroke (NINDS) trial. The mean total death rate (13.4%) and proportion of subjects achieving a very favorable outcome (37.1%) were comparable to the NINDS trial results. Protocol deviations were reported in 19.8%. Comparing across studies showed that the mortality rate was correlated with the percentage of protocol violations (
r
=0.67,
P
=0.018).

Conclusions—

Postapproval data support the safety of intravenous thrombolytic therapy with tPA for acute ischemic stroke, especially when established treatment guidelines are followed.
Emergent Stenting to Treat Patients With Carotid Artery Dissection
Authors: Cohen José E. , Leker Ronen R. , Gotkine Marc , Gomori Moshe , Ben-Hur Tamir
Published: November 2003

Background and Purpose—

Carotid artery dissection (CAD) is a common cause of stroke in young patients. Clots formed at the low-flow zone in the false arterial lumen may give rise to distal emboli, and the mural hematoma may eventually occlude the artery. Anticoagulation is currently the accepted treatment, but it is unknown which patients will improve spontaneously, which will respond to anticoagulation, and which will have an exacerbation of ischemic symptoms despite therapy. Endovascular treatment of CAD may be an attractive alternative to anticoagulation, and methods of identifying patients who stand to benefit from such therapy need to be established.

Methods—

We present here 3 cases of spontaneous symptomatic CAD in which endovascular stenting procedures were performed on the basis of a paradigm aimed at identifying potentially salvageable but at-risk brain tissue by combining clinical with MRI (diffusion and perfusion) and angiographic data.

Results—

Diffusion-perfusion MRI mismatches and/or evidence of cerebral ischemia on angiographic parenchymography were identified in all patients. They did not respond to anticoagulation, were therefore treated with endovascular stents, and had excellent outcomes.

Conclusions—

Endovascular stent placement may be an immediate, effective, and safe method of restoring vessel lumen integrity. It may be considered for selected patients who are clinically symptomatic despite anticoagulant treatment and in whom neuroimaging methods suggest that the neurological signs originate from a viable, hypoperfused, ischemic penumbra.
Pressures for Continuity in the Context of Globalization
Authors: Smelser Neil J.
Published: November 2003

This article challenges the widely held assumption that globalization is creating a new type of world society at the expense of the nation-state. Arguments assembled to support this challenge include the reminder that vast social changes are inevitably incremental in character; that increasing complexity rather than revolutionary transformation is the theme of contemporary social changes in the world; that the staying-power of sovereign states is impressive, and that a number of factors including the international terrorist threat are shoring them up; and with respect to cultural change the prospect is for continuity of processes already under way rather than radical transformation.
A Global World, Multiple Angles, One Sociological Community
Authors: Reis Elisa P.
Published: November 2003

The author calls attention to the need to contemplate systematic spatial comparisons and to embrace an explicit commitment to the analysis of processes with greater determination. In her view, the option for recontextualizing disembodied social players may contribute to a sharper picture of the present day malaise, and hopefully also elicit new interpretations or explanations. She envisages an enlarged role for sociologists as an international community of scholars based upon investigations that incorporate an awareness of the historical transformations of the very concepts in use. As she puts it, to take into account changes in sociologys conceptual universe is, in itself, a way to re-embody time, to reintroduce history into the self-reflexive transformation in process.
Sociology without Societies
Authors: Touraine Alain
Published: November 2003

Sociology is the study of societ(ies): this expression sounds so obvious that it has not even been discussed. Most people have agreed, moreover, that a society is defined by a correspondence between institutions, values and forms of authority, on one side, and internalized norms and agencies of socialization and maintenance of normal behavior, on the other. Very few people today use these words or this general frame of reference, because societies, to a large extent, have disappeared, fallen into pieces or faded away. We are in a constantly changing world and there is no general, integrated process of change. We live in social settings in which the autonomization of various components of social life is so complete that it is useless to consider them as subsystems. Many sociologists are satisfied with notions like mass culture, individualization, fragmentation or dissocialization processes, or are fascinated by a spreading violence, internal or international wars and our capacity for self-destruction, etc. But this approach is too limited, because it is entirely negative. Thus, a high priority for sociologists is to propose one or various images of social actors collective or individual. But is it possible to propose an analysis of actors completely separate from a theory of social systems? This article proposes a positive answer to this difficult question.
Analysis for Load-Balancing Techniques in Intelligent Network Systems
Authors: Deok Noh Yong , Hoon Song Sang
Published: November 2003

The main idea behind the intelligent networks (IN) concept is to place the intelligence/service logic in the dedicated server and to meet various service requirements of subscribers and the development of new services in time. The ( N + 1)-type architecture of the IN service system consists of front-end processors (FEP) and back-end processors (BEP), which are currently in service by a telecommunications company in Korea. The main characteristic of this architecture is a separation between the data plane and control plane of the network, such that the load-balancing table is used to distribute the traffic load among the processors, FEP and BEP, taking into account services. Since the values used in the load-balancing table affect the IN system performance significantly, this paper simulates the IN system and evaluates system performance depending on the values used in the table.
Views of War: Britain Before the ‘Great War’ – and After
Authors: Steiner Zara
Published: November 2003

The First World War changed everything, including European attitudes towards war–and we should not forget what a sea-change this represented. But we should not underestimate the extent to which war before 1914 was thought possible, probable and even desirable. And this was as true for Great Britain as it was for its main German rival. Certain currents of thought made the idea of war seem acceptable. A number of organizations indeed propagated the notion that imperial expansion and conflict–fuelled by jingoism and dreams of Empire–were to be expected in a world where the fittest survived and the weak did not. With the coming of peace following such huge losses on the western front, the mood, inevitably, shifted in almost the opposite direction, and after 1919 public opinion became decidedly anti-war and deeply opposed to rearmament, even when Britain was confronted with the threat of Hitler. Appeasement thus was not merely a policy agreed from on high, but had the solid backing of a public whose attitudes had been so altered by the experience 1914–1918. This mood only began to change after Munich and Kristallnacht. Even so, the mood in 1939 was very different to what it had been in 1914: war with Germany now was not embraced enthusiastically but as a politicaland strategic necessity imposed from without. The Great War had left its indelible mark on those who remembered.
The Political Theory of Trusteeship and the Twilight of International Equality
Authors: Bain William
Published: November 2003

The appalling state in which a significant proportion of the world’s population lives has reinvigorated interest in trusteeship as a way of responding to problems of international disorder and injustice. Trusteeship presupposes a relationship in which a natural person or a legal person is responsible for the well-being of persons who are incapable of acting for themselves. This article explores what is at stake in resurrecting trusteeship in a society of states that is constituted in part by the fundamental juridical equality of its members. An examination of the procedural ethics of trusteeship, prevailing beliefs about independence in international society, and the type of association in which trusteeship might be morally sustainable informs the conclusion that the resurrection of trusteeship necessarily entails the death of the principle of universal equality among states.
‘Losing Control’ – War and the Modern World
Authors: Rogers Paul
Published: November 2003

Trends in military postures since the end of the Cold War have involved major changes in force dispositions that are considered appropriate to maintaining western security in a volatile world. These trends are analysed in the context of the US posture and the development of asymmetric warfare and the evolution of political violence both before and after 11 September 2001. In doing so the article questions whether it is possible for the United States and its allies to maintain control of the international security environment or whether more radical approaches to ensuring international stability are required.