bluuebunny/crossref_metadata_2025 huggingface dataset:
AN ENHANCED TECHNIQUE FOR ANALYZING STRUCTURAL VIBRATION PROBLEMS UNDER SHOT NOISE LOADING
Authors: BARATTA ALESSANDRO , CORBI OTTAVIA
Published: December 2005

The present paper deals with dynamic nonlinear systems loaded by badly defined forcing actions. As an improvement on the first approximate procedure developed by the authors, a more feasible and reliable alternative entropic closure approach is presented herein. Such a procedure allows one to deal with high order nonlinearities, and it can be suitably generalized to treating multi-degree of freedom (MDOF) systems. In fact, the effectiveness of the proposed approach is intricately linked to the exact calculation of some multiple integrals related to the approximate expression of the chosen response probability function. To this end, a procedure that can guarantee high accuracy in the computation of integrals is also studied, which helps in validating the whole approach.
EVALUATION OF THE LEVER-TYPE MULTIPLE TUNED MASS DAMPERS FOR MITIGATING HARMONICALLY FORCED VIBRATION
Authors: LI CHUNXIANG , LI Q. S.
Published: December 2005

The lever-type multiple tuned mass dampers (LT-MTMD), consisting of several lever-type tuned mass dampers (LT-TMDs) with a uniform distribution of natural frequencies, are proposed for the vibration control of long-span bridges. Using the analytical expressions for the dynamic magnification factors (DMF) of the LT-MTMD structure system, an evaluation, with inclusion of the LT-MTMD stroke, is conducted on the performance of the LT-MTMD with identical stiffness and damping coefficients but unequal masses for mitigating harmonically forced vibrations. The LT-MTMD is found to possess the near-zero optimum average damping ratio regimen when the total number of dampers exceeds a certain value. In comparison, the LT-MTMD without the near-zero optimum average damping ratio and the traditional hanging-type multiple tuned mass dampers (HT-MTMD) without the near-zero optimum average damping ratio can achieve approximately the same optimum frequency spacing (an indicator for robustness), effectiveness, and stroke. Compared with the HT-MTMD, the LT-MTMD needs lesser optimum average damping ratio but significantly higher optimum tuning frequency ratio. Its main advantage is that the static stretching of the spring may be adjusted to meet the practical requirements through the support movement, while maintaining the same robustness, effectiveness, and stroke. Consequently, the LT-MTMD is a better choice for suppressing the vibration of long-span bridges as the static stretching of the spring required is not large.
Angiotensin-mediated increase in renal sympathetic nerve discharge within the PVN: role of nitric oxide
Authors: Li Yi-Fan , Wang Wei , Mayhan William G. , Patel Kaushik P.
Published: December 2005

The paraventricular nucleus (PVN) of the hypothalamus is known to be an important site of integration in the central nervous system for sympathetic outflow. ANG II and nitric oxide (NO) play an important role in regulation of sympathetic nerve activity. The purpose of the present study was to examine how the interaction between NO and ANG II within the PVN affects sympathetic outflow in rats. Renal sympathetic nerve discharge (RSND), arterial blood pressure (AP), and heart rate (HR) were measured in response to administration of ANG II and NG-monomethyl-l-arginine (L-NMMA) into the PVN. Microinjection of ANG II (0.05, 0.5, and 1.0 nmol) into the PVN increased RSND, AP, and HR in a dose-dependent manner, resulting in increases of 53 ± 9%, 19 ± 3 mmHg, and 32 ± 12 beats/min from baseline, respectively, at the highest dose. These responses were significantly enhanced by prior microinjection of L-NMMA and were blocked by losartan, an ANG II type 1 receptor antagonist. Similarly, administration of antisense to neuronal NO synthase within the PVN also potentiated the ANG II responses. Conversely, overexpression of neuronal NOS within the PVN with adenoviral gene transfer significantly attenuated ANG II responses. Push-pull administration of ANG II (1 nmol) into the PVN induced an increase in NO release. Our data indicate that ANG II type 1 receptors within the PVN mediate an excitatory effect on RSND, AP, and HR. NO in the PVN, which can be induced by ANG II stimulation, in turn inhibits the ANG II-mediated increase in sympathetic nerve activity. This negative-feedback mechanism within the PVN may play an important role in maintaining the overall balance and tone of sympathetic outflow.
Effect of chronic continuous or intermittent hypoxia and reoxygenation on cerebral capillary density and myelination
Authors: Kanaan Amjad , Farahani Reza , Douglas Robert M. , LaManna Joseph C. , Haddad Gabriel G.
Published: December 2005

Chronic hypoxia, whether continuous (CCH) or intermittent (CIH), occurs in many neonatal pathological conditions, such as bronchopulmonary dysplasia and obstructive sleep apnea. In this study, we explored the effect of CCH and CIH on cerebral capillary density and myelination. We subjected CD-1 mice starting at postnatal day 2 to either CCH 11% oxygen (O2), or CIH 11% O2(4-min cycles), for periods of 2 and 4 wk followed by reoxygenation for 4 wk. Mice were deeply anesthetized and perfused. Brains were removed to fixative for 24 h, then paraffin-embedded. Coronal brain sections were taken for analysis. Immunocytochemistry for glucose transporter 1 was used to assess angiogenesis, and Luxol fast blue and fluoromyelin stains were used to assess myelination. Capillary density increased after 2-wk exposure to CIH and CCH. By 4 wk, capillary density increased in both CIH and CCH by 25% and 47%, respectively, in cortex and by 29% and 44%, respectively, in hippocampus ( P < 0.05). There was a decrease in myelination in the corpus callosum of mice exposed to CIH (75% of control) and CCH (50% of control) ( P < 0.05). Reoxygenation reversed the increased capillary density seen in CCH to normoxic values. However, dysmyelination that occurred in CCH-exposed mice did not show any improvement upon reoxygenation. We conclude that neonatal chronic hypoxia 1) induces brain angiogenesis, which is reversible with reoxygenation, and 2) irreversibly reduces the extent of myelination in the corpus callosum. This potential irreversible effect on myelination in early life can, therefore, have long-term and devastating effects.
ABC drug transporter expression and functional activity in trophoblast-like cell lines and differentiating primary trophoblast
Authors: Evseenko Denis A. , Paxton James W. , Keelan Jeffrey A.
Published: December 2005

ATP-binding cassette (ABC) efflux transporters are expressed in the human placenta where they are thought to help protect the fetus from xenobiotics. To evaluate models for analysis of ABC transporter function and regulation in the placenta, we have characterized the expression and activity of multidrug resistance (MDR) 1/P glycoprotein (Pgp), MDR3/Pgp, breast cancer resistance protein (BCRP), and multidrug resistance proteins 1 and 2 (MRPs 1, 2) in differentiating primary trophoblast cells and BeWo and Jar cell lines. Real-time PCR and immunoblotting were used for analysis of mRNA and protein expression, respectively. Functional activity was measured using selective inhibitors of efflux of fluorescent substrates, calcein-AM (Pgp and MRPs) and Hoechst 33342 (BCRP). The levels of MDR1 mRNA and protein expression were much higher in trophoblast than in Jar and especially BeWo cells. Expression of MDR3 protein was also lower in BeWo cells. Levels of MDR3 expression were markedly higher than MDR1 levels in all tested cell types. Levels of both MDR1 and MDR3 expression decreased during trophoblast differentiation/syncytialization. BCRP was highly expressed in all cell types and increased with trophoblast differentiation. MRP1 expression was much lower in trophoblasts compared with both cell lines. In contrast to its abundant mRNA expression, MRP2 protein was practically undetectable in BeWo and Jar cells and was present only at very low levels in trophoblast. Functional studies confirmed the presence of active Pgp and BCRP in all studied cell types, whereas MRP functional activity was detected only in BeWo and Jar cells. Both cell lines may be useful models for studying various aspects of placental ABC transporter expression and function, but also have significant limitations. With respect to their ABC protein expression profile, Jar cells are more similar to nondifferentiated cytotrophoblast, whereas BeWo appear to more closely reflect differentiated syncytiotrophoblast.
Involvement of RhoA/Rho kinase signaling in pulmonary hypertension of the fawn-hooded rat
Authors: Nagaoka Tetsutaro , Gebb Sarah A. , Karoor Vijaya , Homma Noriyuki , Morris Kenneth G. , McMurtry Ivan F. , Oka Masahiko
Published: December 2005

The fawn-hooded rat (FHR) develops severe pulmonary hypertension (PH) when raised for the first 3–4 wk of life in the mild hypoxia of Denver’s altitude (5,280 ft.). The PH is associated with sustained pulmonary vasoconstriction and pulmonary artery remodeling. Furthermore, lung alveolarization and vascularization are reduced in the Denver FHR. We have recently shown that RhoA/Rho kinase signaling is involved in both vasoconstriction and vascular remodeling in animal models of hypoxic PH. In this study, we investigated the role of RhoA/Rho kinase signaling in the PH of Denver FHR. In α-toxin permeabilized pulmonary arteries from Denver FHR, the contractile sensitivity to Ca2+was increased compared with those from sea-level FHR. RhoA activity and Rho kinase I protein expression in pulmonary arteries of Denver FHR (10-wk-old) were higher than in those of sea-level FHR. Acute inhalation of the Rho kinase inhibitor fasudil selectively reduced the elevated pulmonary arterial pressure in Denver FHR in vivo. Chronic fasudil treatment (30 mg·kg−1·day−1, from birth to 10 wk old) markedly reduced the development of PH and improved lung alveolarization and vascularization in Denver FHR. These results suggest that Rho kinase-mediated sustained vasoconstriction, through increased Ca2+sensitivity, plays an important role in the established PH and that RhoA/Rho kinase signaling contributes significantly to the development of PH and lung dysplasia in mild hypoxia-exposed FHR.
Evidence for a Gene Influencing High-Density Lipoprotein Cholesterol on Chromosome 4q31.21
Authors: Dastani Zari , Quiogue Leigh , Plaisier Christopher , Engert James C. , Marcil Michel , Genest Jacques , Pajukanta Päivi
Published: December 2005

Objective—

A low level of plasma high-density lipoprotein cholesterol (HDL-C) is a major risk factor for coronary atherosclerosis. To identify novel genes regulating plasma HDL-C levels, we investigated 13 multigenerational French Canadian families with an average of 12 affected individuals per family for genome-wide signals, which we subsequently fine mapped.

Methods and Results—

We genotyped a total of 362 individuals, including 151 affected subjects for 485 autosomal microsatellite markers. In parametric 2-point linkage analyses, the highest 2-point logarithm of odds (lod) score of 4.6 was observed with marker D4S424 on chromosome 4q31.21 (at ≈142 Mb). The multipoint analysis of this region resulted in a lod score of 3.8 and a lod −1 region of 12.2 cM, containing 40 known genes. The results were obtained by allowing for genetic heterogeneity among these extended pedigrees, and ≈50% of families were linked to this region with the highest single-pedigree lod score being 3.6. We further restricted the linked region from 12.2 to 2.9 cM (2.37 Mb) by genotyping 15 additional markers in the 3 families with the highest lod scores. We sequenced 4 genes with a likely role in lipid metabolism as well as 2 genes residing directly under the linkage peak but found no evidence for a causative variant. None of the genes residing in the significantly restricted 2.37-Mb region has been associated previously with HDL-C metabolism.

Conclusion—

This study provides significant evidence for a gene influencing HDL-C on chromosome 4q31.21.
Socioeconomic Differences in Progression of Carotid Intima-Media Thickness in the Atherosclerosis Risk in Communities Study
Authors: Ranjit Nalini , Diez-Roux Ana V. , Chambless Lloyd , Jacobs David R. , Nieto F. Javier , Szklo Moyses
Published: December 2005

Objective—

To examine the association of socioeconomic factors with progression of carotid intimal-medial thickness (IMT) in middle-aged adults. Cross-sectional associations of IMT with socioeconomic status (SES) have been demonstrated in middle-aged cohorts. It is unclear whether these factors are associated with progression of IMT.

Methods and Results—

We examined IMT progression over 9 years among a middle-aged cohort of 12 085 black and white subjects free of cardiovascular disease recruited from 4 US sites participating in the Atherosclerosis Risk in Communities (ARIC) study. Baseline IMT was inversely related to SES among whites and blacks. Repeated measures regression models of IMT progression showed moderate inverse relationships of IMT progression with income in whites so that the difference in 5-year IMT progression rates between the highest and lowest categories was −11.5 μm (CI, −17.4 to −5.6). In contrast, among blacks, this gradient is reversed, with an 11.1 μm (CI, −0.1 to 22.3) difference in 5-year progression between highest and lowest income category. Generally, similar patterns were observed for other socioeconomic indicators. Patterns were not accounted for by baseline cardiovascular risk factors.

Conclusions—

SES is inversely related to IMT progression in middle-aged whites but positively related to IMT progression among middle-aged blacks. These differences do not appear to be attributable to selective attrition or higher IMT among blacks at baseline.
Genotype and Haplotype Association Study of the
STRK1
Region on 5q12 Among Japanese
Authors: Nakayama Tomohiro , Asai Satoshi , Sato Naoyuki , Soma Masayoshi
Published: December 2005

Background and Purpose—

Cerebral infarction is thought to be a multifactorial disease that is affected by several environmental factors and genetic variants. Gretarsdottir et al identified a candidate locus (
STRK1
) for cerebral infarction with a significant logarithm of odds score at 5q12 in whites in 2002 and subsequently identified the
PDE4D
gene as a susceptibility gene at this locus in 2003. The aims of this haplotype-based case-control study were to confirm, using microsatellite markers and single-nucleotide polymorphisms (SNPs), whether
PDE4D
is also a susceptibility gene for cerebral infarction in Japanese subjects.

Methods—

Cerebral infarction was defined as noncardiogenic ischemic stroke with signs and symptoms lasting >1 month in duration. We genotyped 208 Japanese cerebral infarction patients and 270 non–cerebral infarction controls for 31 SNPs, 3 dinucleotide microsatellites, and 1 tetranucleotide variable number of tandem repeat. Haplotypes were constructed and their frequencies compared between the cerebral infarction patients and the controls.

Results—

The haplotype-based case-control study revealed that in addition to the region of the
PDE4D
gene (
P
=0.002), another region (
P
<0.001) also existed within the
STRK1
locus.

Conclusions—

The region of the
PDE4D
gene and the other newly detected region within the
STRK1
locus were associated with cerebral infarction.
A Randomized Controlled Trial of Functional Neuromuscular Stimulation in Chronic Stroke Subjects
Authors: Daly Janis J. , Roenigk Kristen , Holcomb, PhD John , Rogers Jean M. , Butler Kristen , Gansen Jennifer , McCabe Jessica , Fredrickson Eric , Marsolais E. Byron , Ruff Robert L.
Published: December 2005

Background and Purpose—

Conventional therapies fail to restore normal gait to many patients after stroke. The study purpose was to test response to coordination exercise, overground gait training, and weight-supported treadmill training, both with and without functional neuromuscular stimulation (FNS) using intramuscular (IM) electrodes (FNS-IM).

Methods—

In a randomized controlled trial, 32 subjects (>1 year after stroke) were assigned to 1 of 2 groups: FNS-IM or No-FNS. Inclusion criteria included ability to walk independently but inability to execute a normal swing or stance phase. All subjects were treated 4 times per week for 12 weeks. The primary outcome measure, obtained by a blinded evaluator, was gait component execution, according to the Tinetti gait scale. Secondary measures were coordination, balance, and 6-minute walking distance.

Results—

Before treatment, there were no significant differences between the 2 groups for age, time since stroke, stroke severity, and each study measure. FNS-IM produced a statistically significant greater gain versus No-FNS for gait component execution (
P
=0.003; parameter estimate 2.9; 95% CI, 1.2 to 4.6) and knee flexion coordination (
P
=0.049).

Conclusion—

FNS-IM can have a significant advantage versus No-FNS in improving gait components and knee flexion coordination after stroke.
Recruiting Subjects for Acute Stroke Trials
Authors: Elkins Jacob S. , Khatabi Talayeh , Fung Lawrence , Rootenberg John , Johnston S. Claiborne
Published: December 2005

Background and Purpose—

Recruitment rate is a major determinant of the duration, cost, and feasibility of acute stroke trials.

Methods—

We performed a meta-analysis of all randomized, controlled trials of ≥300 subjects that were designed to evaluate the efficacy of a medical intervention for the treatment of acute ischemic stroke. Data about trial recruitment, organization, and inclusion/exclusion criteria were abstracted independently by 2 reviewers who applied predefined criteria. Recruitment efficiency was defined as the number of subjects enrolled per study center per month of recruitment.

Results—

Of 32 trials meeting inclusion criteria, the average recruitment efficiency was 0.79 subjects per center per month (range 0.08 to 3.7). Recruitment efficiency did not vary by geographic region (
P
=0.36), but trials conducted in 1 country had more efficient recruitment than international studies (
P
=0.03), and recruitment efficiency declined with each percentage increase in the total number of study centers (
P
=0.002). The primary study entry criteria that predicted reduced recruitment efficiency were the maximum allowable time from stroke to study enrollment (
P
=0.002) and the exclusion of mild strokes (
P
=0.009). Trials with a treatment window >6 hours had approximately double the recruitment rates of trials that used treatment windows ≤6 hours (1.03 versus 0.52 patients per center per month).

Conclusion—

Recruitment rates for acute stroke trials are influenced by organizational structure and study entry criteria. Characterizing predictors of recruitment may help optimize future trial design.
Elevations in Preoperative Monocyte Count Predispose to Acute Neurocognitive Decline After Carotid Endarterectomy for Asymptomatic Carotid Artery Stenosis
Authors: Mocco J. , Wilson David A. , Ducruet Andrew F. , Komotar Ricardo J. , Mack William J. , Zurica Joseph , Sciacca Robert R. , Heyer Eric J. , Connolly E. Sander
Published: December 2005

Background and Purpose—

Although the incidence of major stroke attributable to carotid endarterectomy (CEA) is low (1% to 2%), ≈25% of patients experience subtle postoperative neurocognitive dysfunction. This study examines whether preoperative leukocyte profiles predict cognitive outcome in asymptomatic CEA patients.

Methods—

Sixty-nine asymptomatic CEA patients underwent neuropsychometric testing preoperatively and on postoperative day 1 (POD1). Preoperative white blood cell counts and differentials were obtained. Logistic regression was performed for risk factors for neurocognitive decline. Variables achieving univariate
P
<0.10 were included in multivariate analysis.

Results—

Eighteen (26%) patients experienced neurocognitive decline on POD1; multivariate analysis demonstrated that preoperative monocyte count (
P
=0.011) and age (
P
=0.02) independently predicted outcome.

Conclusions—

Preoperative monocyte count and age are independently associated with acute neurocognitive decline after CEA for asymptomatic stenosis.
Reduced Vitamin D in Acute Stroke
Authors: Poole Kenneth E. S. , Loveridge Nigel , Barker Peter J. , Halsall David J. , Rose Collette , Reeve Jonathan , Warburton Elizabeth A.
Published: December 2005

Background and Purpose—

Stroke leads to a reduction in bone mineral density, altered calcium homeostasis, and an increase in hip fractures. Vitamin D deficiency is well documented in long-term stroke survivors and is associated with post-stroke hip fractures. Less is known regarding levels in acute stroke.

Methods—

We compared the serum 25-dihydroxyvitamin D levels of 44 patients admitted to an acute stroke unit with first-ever stroke with results obtained by measuring 96 healthy ambulant elderly subjects every 2 months for 1 year. Statistical
Z
scores of serum vitamin D were then calculated after seasonal adjustment for the month of sampling.

Results—

The mean
Z
score of vitamin D in acute stroke was −1.4 SD units (95% CI, −1.7, −1.1), with 77% of patients falling in the insufficient range.

Conclusions—

Reduced vitamin D was identified in the majority of patients with acute stroke throughout the year and may have preceded stroke. Vitamin D is a potential risk marker for stroke, and the role of vitamin D repletion in enhancing musculoskeletal health after stroke needs to be explored.
Genome-Wide Scan for White Matter Hyperintensity
Authors: DeStefano Anita L. , Atwood Larry D. , Massaro Joseph M. , Heard-Costa Nancy , Beiser Alexa , Au Rhoda , Wolf Philip A. , DeCarli Charles
Published: December 2005

Background and Purpose—

White matter hyperintensity (WMH) volume is associated with aging and cerebrovascular disease and has been demonstrated to have a high heritability in the Framingham Heart Study as well as in other studies. We performed a genome-wide linkage analysis to identify chromosomal regions that may harbor genes influencing WMH in a family-based sample of the Framingham Heart Study.

Methods—

Brain magnetic resonance scans were performed, and WMH and total cranial volume (TCV) were quantified as previously described on 2259 cohort and offspring participants. The outcome used for linkage analysis was an age specific (within 10-year age groups) z-score for the natural logarithm of the ratio of WMH to TCV. This z-score was based on 2230 individuals after excluding 26 participants with neurological conditions other than stroke and 3 individuals whose ages were out of range. Variance component linkage analysis included 747 individuals (mean age=62.16±12.43 years) with both magnetic resonance measure and genotype information in 237 families. Mean percent WMH to TCV was 0.098±0.175 with a range of 0.00025% to 1.37% in the linkage analysis subjects.

Results—

A maximum multipoint logarithm of the odds (LOD) score=3.69, which indicates significant evidence of linkage, was observed at 4 cM on chromosome 4. A suggestive peak with LOD=1.78 was observed at 95 cM on chromosome 17.

Conclusion—

We have significant evidence that a gene influencing WMH volume is located on chromosome 4 of the human genome.
Regular Aspirin-Use Preceding the Onset of Primary Intracerebral Hemorrhage is an Independent Predictor for Death
Authors: Saloheimo Pertti , Ahonen Mikko , Juvela Seppo , Pyhtinen Juhani , Savolainen Eeva-Riitta , Hillbom Matti
Published: December 2005

Background and Purpose—

Hematoma volume and impaired level of consciousness are the most potent predictors of outcome after spontaneous intracerebral hemorrhage (ICH). The effect of preceding aspirin-use on outcome after ICH is poorly investigated. We investigated short-term mortality and hematoma enlargement in subjects with ICH to find the predictors for these outcomes.

Methods—

This population-based study included all subjects with ICH during a period of 33 months in the population of Northern Ostrobothnia, Finland. The subjects were identified, and their clinical characteristics and outcomes were checked from hospital records or death records.

Results—

Three-month mortality of the 208 identified subjects with ICH was 33%. The independent risk factors for death were regular aspirin-use at the onset of ICH (relative risks [RR], 2.5; 95% CI, 1.3 to 4.6;
P
=0.004), warfarin-use at the onset of ICH (RR, 3.2; 95% CI, 1.6 to 6.1;
P
=0.001), and ICH score higher than 2 on admission (RR, 13.8; 95% CI, 6.0 to 31.4;
P
<0.001). Regular aspirin-use preceding the onset of ICH associated significantly with hematoma enlargement during the first week after ICH (
P
=0.006).

Conclusions—

We observed poor short-term outcomes and increased mortality, probably attributable to rapid enlargement of hematomas, in the subjects with ICH who had been taking regularly moderate doses of aspirin (median 250 mg) immediately before the onset of the stroke.
Environmental Perspectives and Behavior in China
Authors: Harris Paul G.
Published: December 2005

Some of the world's most profound environmental changes are under way in China. Studying the underlying forces of environment-related behaviors at all levels in China is therefore extraordinarily important. This essay helps people outside China increase their understanding of these variables by summarizing findings of Chinese-language surveys conducted in China to measure environmental awareness, attitudes, and behaviors. People in different parts of China have differences in perceptions and behaviors. The article takes a macroscopic snapshot of how the Chinese view their environment as a prelude to analyses of more particularistic perceptions and actions. This snapshot depicts environmental destruction and rampant resource exploitation that is likely to continue for decades to come. However, by understanding this trend it may be possible to findways of eventually slowing it and thereby mitigating long-term environmental damage. The article includes an annotated bibliography of Chinese-language reports on environmental attitudes and behaviors.
Revolutionary family life and the Self Respect movement in Tamil south India, 1926–49
Authors: Hodges Sarah
Published: December 2005

During the second quarter of the 20th century, the Self Respect movement (cuyamariyatai iyakkam) introduced a programme of non-Brahmin uplift in Tamil south India that consisted of a radical critique of social, political and economic relations. By following the coverage of family and marriage in the Self Respect popular press (the weekly newspaper Kudi Arasu in particular), and through interviews with Self Respecters who lived through the period 1926–49, this article attempts to sketch out how and why the family was interpolated both as an object of criticism and as a site of struggle. That is to say, Self Respect was not only a set of arguments, but also a set of practical strategies for transforming everyday and ritual life into revolutionary propaganda through choice of dress, names, home décor and domestic ritual, as well as through attending public meetings and reading newspapers. In particular, ‘modern, Self Respecting Tamil couples’ were projected as a resolution to what the Self Respect movement high-lighted as the social, political and economic problems perpetuated by the traditional joint family. Yet, over the course of the 20th century in the Tamil south, marriage and family proved to be unstable vehicles for the revolutionary transformation of socio-political domains.
Protection of erythrocytes from human complement–mediated lysis by membrane-targeted recombinant soluble CD59: a new approach to PNH therapy
Authors: Hill Anita , Ridley Simon H. , Esser Dirk , Oldroyd Rodney G. , Cullen Matthew J. , Kareclas Paula , Gallagher Seán , Smith Geoffrey P. , Richards Stephen J. , White Jennifer , Smith Richard A. G. , Hillmen Peter
Published: December 2005

Paroxysmal nocturnal hemoglobinuria (PNH) results from the expansion of a hematopoietic clone that is deficient in glycosylphosphatidylinositol-anchored molecules. PNH is characterized by chronic hemolysis with acute exacerbations due to the uncontrolled activity of complement on PNH cells, which lack the inhibitor of homologous complement, CD59. Symptoms include severe fatigue, hemoglobinuria, esophageal spasm, erectile dysfunction, and thrombosis. We report the use of a novel synthetically modified recombinant human CD59, rhCD59-P, a soluble protein that attaches to cell membranes. In vitro treatment of PNH erythrocytes with rhCD59-P resulted in levels of CD59 equivalent to normal erythrocytes and effectively protected erythrocytes from complement-mediated hemolysis. The administration of rhCD59-P to CD1 mice resulted in levels of CD59 on erythrocytes, which protected them from complement-mediated lysis. Thus, rhCD59-P corrects the CD59 deficiency in vitro and can bind to erythrocytes in an in vivo murine model, protecting the cells from the activity of human complement, and represents a potential therapeutic strategy in PNH.
Intravascular survival of red cells coated with a mutated human anti-D antibody engineered to lack destructive activity
Authors: Armour Kathryn L. , Parry-Jones David R. , Beharry Nigel , Ballinger James R. , Mushens Rosey , Williams R. Keith , Beatty Cynthia , Stanworth Simon , Lloyd-Evans Paul , Scott Marion , Clark Michael R. , Peters A. Michael , Williamson Lorna M.
Published: December 2005

Alloimmune feto-maternal destruction of blood cells is thought to be mediated by binding of alloantibodies to Fc receptors on effector cells. Blocking the antigen using inert antibodies might prolong cell survival. We have performed a “proof of principle” study in volunteers to measure the intravascular survival of autologous red cells coated with human recombinant IgG antibody containing a novel constant region, G1Δnab, devoid of in vitro cytotoxic activity. RhD-positive red blood cells (RBCs), labeled with chromium-51 or technetium-99m, were separately coated to equal levels with wild-type IgG1 or G1Δnab anti-D antibody (Fog-1). After re-injection, there was complete, irreversible clearance of IgG1-coated RBCs by 200 minutes, concomitant with appearance of radiolabel in plasma. Gamma camera imaging revealed accumulation in spleen and, at higher coating levels, in liver. In contrast, clearance of G1Δnab-coated cells was slower, incomplete, and transient, with whole blood counts falling to 7% to 38% injected dose by about 200 minutes before increasing to 12% to 67% thereafter. There was no appearance of plasma radiolabel and no hepatic accumulation. These findings suggest that G1Δnab-coated RBCs were not hemolysed but temporarily sequestered in the spleen and that our approach merits investigation in larger studies.
Heterodimerization of FGF-receptor 1 and PDGF-receptor-α: a novel mechanism underlying the inhibitory effect of PDGF-BB on FGF-2 in human cells
Authors: Faraone Debora , Aguzzi Maria S. , Ragone Gianluca , Russo Katia , Capogrossi Maurizio C. , Facchiano Antonio
Published: December 2005

Previous evidence has shown that platelet-derived growth factor-BB (PDGF-BB) and fibroblast growth factor-2 (FGF-2) directly interact with high affinity, leading to potent reciprocal inhibitory effects on bovine endothelial cells and rat vascular smooth muscle cells. In this study, we report that PDGF-BB inhibits a series of FGF-2–induced events, such as proliferation of human umbilical vein endothelial cells (HUVECs), FGF-2 cellular internalization, phosphorylation of intracellular signaling factors including p38, rac1/cdc42, MKK4, and MKK3/6, and phosphorylation of FGF-receptor 1 (FGF-R1). PDGF-receptor-α (PDGF-Rα) was found to mediate PDGF-BB inhibitory effects because its neutralization fully restored FGF-2 mitogenic activity and internalization. Additional biochemical analyses, coimmunoprecipitation experiments, and FRET analysis showed that FGF-R1 and PDGF-Rα directly interact in vitro and in vivo and that this interaction is somehow increased in the presence of the corresponding ligands FGF-2 and PDGF-BB. These results suggest that FGF-R1/PDGF-Rα heterodimerization may represent a novel endogenous mechanism to modulate the action of these receptors and their ligands and to control endothelial cell function.
The soluble extracellular domain of EphB4 (sEphB4) antagonizes EphB4-EphrinB2 interaction, modulates angiogenesis, and inhibits tumor growth
Authors: Kertesz Nathalie , Krasnoperov Valery , Reddy Ramachandra , Leshanski Lucy , Kumar S. Ram , Zozulya Sergey , Gill Parkash S.
Published: December 2005

The receptor tyrosine kinase EphB4 and its ligand EphrinB2 play a crucial role in vascular development during embryogenesis. The soluble monomeric derivative of the extracellular domain of EphB4 (sEphB4) was designed as an antagonist of EphB4/EphrinB2 signaling. sEphB4 blocks activation of EphB4 and EphrinB2; suppresses endothelial cell migration, adhesion, and tube formation in vitro; and inhibits the angiogenic effects of various growth factors (VEGF and bFGF) in vivo. sEphB4 also inhibits tumor growth in murine tumor xenograft models. sEphB4 is thus a therapeutic candidate for vascular proliferative diseases and cancer.
Impact of mutations in the von Willebrand factor A2 domain on ADAMTS13-dependent proteolysis
Authors: Hassenpflug Wolf Achim , Budde Ulrich , Obser Tobias , Angerhaus Dorothea , Drewke Elke , Schneppenheim Sonja , Schneppenheim Reinhard
Published: December 2005

Classical von Willebrand disease (VWD) type 2A, the most common qualitative defect of VWD, is caused by loss of high-molecular-weight multimers (HMWMs) of von Willebrand factor (VWF). Underlying mutations cluster in the A2 domain of VWF around its cleavage site for ADAMTS13. We investigated the impact of mutations commonly found in patients with VWD type 2A on ADAMTS13-dependent proteolysis of VWF. We used recombinant human ADAMTS13 (rhuADAMTS13) to digest recombinant full-length VWF and a VWF fragment spanning the VWF A1 through A3 domains, harboring 13 different VWD type 2A mutations (C1272S, G1505E, G1505R, S1506L, M1528V, R1569del, R1597W, V1607D, G1609R, I1628T, G1629E, G1631D, and E1638K). With the exception of G1505E and I1628T, all mutations in the VWF A2 domain increased specific proteolysis of VWF independent of the expression level. Proteolytic susceptibility of mutant VWF in vitro closely correlated with the in vivo phenotype in patients. The results imply that increased VWF susceptibility for ADAMTS13 is a constitutive property of classical VWD type 2A, thus explaining the pronounced proteolytic fragments and loss of HMWM seen in multimer analysis in patients.
Overexpression of HES-1 is not sufficient to impose T-cell differentiation on human hematopoietic stem cells
Authors: Hoebeke Inge , De Smedt Magda , Van de Walle Inge , Reynvoet Katia , De Smet Greet , Plum Jean , Leclercq Georges
Published: December 2005

By retroviral overexpression of the Notch-1 intracellular domain (ICN) in human CD34+ hematopoietic stem cells (HSCs), we have shown previously that Notch-1 signaling promotes the T-cell fate and inhibits the monocyte and B-cell fate in several in vitro and in vivo differentiation assays. Here, we investigated whether the effects of constitutively active Notch-1 can be mimicked by overexpression of its downstream target gene HES1. Upon HES-1 retroviral transduction, human CD34+ stem cells had a different outcome in the differentiation assays as compared to ICN-transduced cells. Although HES-1 induced a partial block in B-cell development, it did not inhibit monocyte development and did not promote T/NK-cell-lineage differentiation. On the contrary, a higher percentage of HES-1-transduced stem cells remained CD34+. These experiments indicate that HES-1 alone is not able to substitute for Notch-1 signaling to induce T-cell differentiation of human CD34+ hematopoietic stem cells.
Human neutrophil peptides induce interleukin-8 production through the P2Y6 signaling pathway
Authors: Khine Aye Aye , Del Sorbo Lorenzo , Vaschetto Rosanna , Voglis Stefanos , Tullis Elizabeth , Slutsky Arthur S. , Downey Gregory P. , Zhang Haibo
Published: December 2005

Antimicrobial human neutrophil peptides (HNPs) play a pivotal role in innate host defense against a broad spectrum of prokaryotic pathogens. In addition, HNPs modulate cellular immune responses by producing the chemokine interleukin-8 (IL-8) in myeloid and epithelial cells and by exerting chemotaxis to T cells, immature dendritic cells, and monocytes. However, the mechanisms by which HNPs modulate the immune responses in the eukaryotic cells remain unclear. We demonstrated that, as with adenosine triphosphate (ATP) and uridine diphosphate (UDP), HNP stimulation of human lung epithelial cells selectively induced IL-8 production in 10 pro- and anti-inflammatory cytokines examined. HNP-induced IL-8 release was inhibited by treatment with the nucleotide receptor antagonists suramin and reactive blue. Transfection of lung epithelial cells with antisense oligonucleotides targeting specific purinergic P2Y receptors revealed that the P2Y6 (ligand of UDP) signaling pathway plays a predominant role in mediating HNP-induced IL-8 production.
Id helix-loop-helix proteins negatively regulate TRANCE-mediated osteoclast differentiation
Authors: Lee Junwon , Kim Kabsun , Kim Jung Ha , Jin Hye Mi , Choi Han Kyung , Lee Seoung-Hoon , Kook Hyun , Kim Kyung Keun , Yokota Yoshifumi , Lee Soo Young , Choi Yongwon , Kim Nacksung
Published: December 2005

Tumor necrosis factor (TNF)–related activation-induced cytokine (TRANCE) induces osteoclast formation from monocyte/macrophage lineage cells via various transcription factors, including the Mi transcription factor (Mitf). Here, we show that inhibitors of differentiation/DNA binding (Ids), helix-loop-helix (HLH) transcription factors, negatively regulate TRANCE-induced osteoclast differentiation. Expression levels of Id1, Id2, and Id3 genes are significantly reduced by TRANCE during osteoclastogenesis. Interestingly, overexpression of the 3 Id genes in bone marrow–derived monocyte/macrophage lineage cells (BMMs) inhibits the formation of tartrate-resistant acid phosphatase (TRAP)–positive multinuclear osteoclasts, but it does not alter the ability of BMMs to either phagocytose or differentiate into dendritic cells (DCs). Overexpression of Id2 in BMMs attenuates the gene induction of nuclear factor of activated T cells c1 (NFATc1) and osteoclast-associated receptor (OSCAR) during TRANCE-mediated osteoclastogenesis. Furthermore, Id proteins interact with Mitf, a basic HLH (bHLH) transcription factor, and inhibit its transactivation of OSCAR, which is a costimulatory receptor expressed by osteoclast precursors, by attenuating the DNA binding ability of Mitf to the E-box site of the OSCAR promoter. Taken together, our results reveal both a new facet of negative regulation, mediated by Id proteins, as well as the mechanism whereby TRANCE signaling overcomes it, allowing osteoclastogenesis to proceed.
Multiple phosphorylation events control mitotic degradation of the muscle transcription factor Myf5
Authors: Doucet Christine , Gutierrez Gustavo J , Lindon Catherine , Lorca Thierry , Lledo Gwendaline , Pinset Christian , Coux Olivier
Published: December 2005

Background

The two myogenic regulatory factors Myf5 and MyoD are basic helix-loop-helix muscle transcription factors undergoing differential cell cycle dependent proteolysis in proliferating myoblasts. This regulated degradation results in the striking expression of these two factors at distinct phases of the cell cycle, and suggests that their precise and alternated disappearance is an important feature of myoblasts, maybe connected to the maintenance of the proliferative status and/or commitment to the myogenic lineage of these cells. One way to understand the biological function(s) of the cyclic expression of these proteins is to specifically alter their degradation, and to analyze the effects of their stabilization on cells. To this aim, we undertook the biochemical analysis of the mechanisms governing Myf5 mitotic degradation, using heterologous systems.

Results

We show here that mitotic degradation of Myf5 is conserved in non-myogenic cells, and is thus strictly under the control of the cell cycle apparatus. Using Xenopus egg extracts as an in vitro system to dissect the main steps of Myf5 mitotic proteolysis, we show that (1) Myf5 stability is regulated by a complex interplay of phosphorylation/dephosphorylation, probably involving various kinases and phosphatases, (2) Myf5 is ubiquitylated in mitotic extracts, and this is a prerequisite to its degradation by the proteasome and (3) at least in the Xenopus system, the E3 responsible for its mitotic degradation is not the APC/C (the major E3 during mitosis).

Conclusion

Altogether, our data strongly suggest that the mitotic degradation of Myf5 by the ubiquitin-proteasome system is precisely controlled by multiple phosphorylation of the protein, and that the APC/C is not involved in this process.
Evolution and origin of merlin, the product of the Neurofibromatosis type 2 (NF2) tumor-suppressor gene
Authors: Golovnina Kseniya , Blinov Alexander , Akhmametyeva Elena M , Omelyanchuk Leonid V , Chang Long-Sheng
Published: December 2005

Background

Merlin, the product of the Neurofibromatosis type 2 (NF2) tumor suppressor gene, belongs to the ezrin-radixin-moesin (ERM) subgroup of the protein 4.1 superfamily, which links cell surface glycoproteins to the actin cytoskeleton. While merlin's functional activity has been examined in mammalian and Drosophila models, little is understood about its evolution, diversity, and overall distribution among different taxa.

Results

By combining bioinformatic and phylogenetic approaches, we demonstrate that merlin homologs are present across a wide range of metazoan lineages. While the phylogenetic tree shows a monophyletic origin of the ERM family, the origin of the merlin proteins is robustly separated from that of the ERM proteins. The derivation of merlin is thought to be in early metazoa. We have also observed the expansion of the ERM-like proteins within the vertebrate clade, which occurred after its separation from Urochordata (Ciona intestinalis). Amino acid sequence alignment reveals the absence of an actin-binding site in the C-terminal region of all merlin proteins from various species but the presence of a conserved internal binding site in the N-terminal domain of the merlin and ERM proteins. In addition, a more conserved pattern of amino acid residues is found in the region containing the so-called "Blue Box," although some amino acid substitutions in this region exist in the merlin sequences of worms, fish, and Ciona. Examination of sequence variability at functionally significant sites, including the serine-518 residue, the phosphorylation of which modulates merlin's intra-molecular association and function as a tumor suppressor, identifies several potentially important sites that are conserved among all merlin proteins but divergent in the ERM proteins. Secondary structure prediction reveals the presence of a conserved α-helical domain in the central to C-terminal region of the merlin proteins of various species. The conserved residues and structures identified correspond to the important sites highlighted by the available crystal structures of the merlin and ERM proteins. Furthermore, analysis of the merlin gene structures from various organisms reveals the increase of gene length during evolution due to the expansion of introns; however, a reduction of intron number and length appears to occur in the merlin gene of the insect group.

Conclusion

Our results demonstrate a monophyletic origin of the merlin proteins with their root in the early metazoa. The overall similarity among the primary and secondary structures of all merlin proteins and the conservation of several functionally important residues suggest a universal role for merlin in a wide range of metazoa.
SiteFind: A software tool for introducing a restriction site as a marker for successful site-directed mutagenesis
Authors: Evans Paul M , Liu Chunming
Published: December 2005

Background

Site-directed mutagenesis is a widely-used technique for introducing mutations into a particular DNA sequence, often with the goal of creating a point mutation in the corresponding amino acid sequence but otherwise leaving the overall sequence undisturbed. However, this method provides no means for verifying its success other than sequencing the putative mutant construct: This can quickly become an expensive method for screening for successful mutations. An alternative to sequencing is to simultaneously introduce a restriction site near the point mutation in manner such that the restriction site has no effect on the translated amino acid sequence. Thus, the novel restriction site can be used as a marker for successful mutation which can be quickly and easily assessed. However, finding a restriction site that does not disturb the corresponding amino acid sequence is a time-consuming task even for experienced researchers. A fast and easy to use computer program is needed for this task.

Results

We wrote a computer program, called SiteFind, to help us design a restriction site within the mutation primers without changing the peptide sequence. Because of the redundancy of genetic code, a given peptide can be encoded by many different DNA sequences. Since the list of possible restriction sites for a given DNA sequence is not always obvious, SiteFind automates this task. The number of possible sequences a computer program must search through increases exponentially as the sequence length increases. SiteFind uses a novel "moving window" algorithm to reduce the number of possible sequences to be searched to a manageable level. The user enters a nucleotide sequence, specifies what amino acid residues should be changed in the mutation, and SiteFind generates a list of possible restriction sites and what nucleotides must be changed to introduce that site. As a demonstration of its use, we successfully generated a single point mutation and a double point mutation in the wild-type sequence for Krüppel-like factor 4, an epithelium-specific transcription factor.

Conclusion

SiteFind is an intuitive, web-based program that enables the user to introduce a novel restriction site into the mutated nucleotide sequence for use as a marker of successful mutation. It is freely available from http://www.utmb.edu/scccb/software/sitefind.html
Stability of response characteristics of a Delphi panel: application of bootstrap data expansion
Authors: Akins Ralitsa B , Tolson Homer , Cole Bryan R
Published: December 2005

Background

Delphi surveys with panels of experts in a particular area of interest have been widely utilized in the fields of clinical medicine, nursing practice, medical education and healthcare services. Despite this wide applicability of the Delphi methodology, there is no clear identification of what constitutes a sufficient number of Delphi survey participants to ensure stability of results.

Methods

The study analyzed the response characteristics from the first round of a Delphi survey conducted with 23 experts in healthcare quality and patient safety. The panel members had similar training and subject matter understanding of the Malcolm Baldrige Criteria for Performance Excellence in Healthcare. The raw data from the first round sampling, which usually contains the largest diversity of responses, were augmented via bootstrap sampling to obtain computer-generated results for two larger samples obtained by sampling with replacement. Response characteristics (mean, trimmed mean, standard deviation and 95% confidence intervals) for 54 survey items were compared for the responses of the 23 actual study participants and two computer-generated samples of 1000 and 2000 resampling iterations.

Results

The results from this study indicate that the response characteristics of a small expert panel in a well-defined knowledge area are stable in light of augmented sampling.

Conclusion

Panels of similarly trained experts (who possess a general understanding in the field of interest) provide effective and reliable utilization of a small sample from a limited number of experts in a field of study to develop reliable criteria that inform judgment and support effective decision-making.