bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex differences in the cerebral BOLD signal response to painful heat stimuli
Authors: Moulton Eric A. , Keaser Michael L. , Gullapalli Rao P. , Maitra Ranjan , Greenspan Joel D.
Published: April 2006

There are limited data addressing the question of sex differences in pain-related cerebral processing. This study examined whether pain-related blood oxygenation level-dependent (BOLD) signal change measured with functional magnetic resonance imaging (fMRI) demonstrated sex differences, under conditions of equivalent pain perception. Twenty-eight healthy volunteers (17 women, 11 men) were subject to a fMRI scan while noxious heat stimuli were applied to the dorsum of the left foot. Significant BOLD signal modulation was observed in several nociceptive processing regions of interest (ROIs) in all subjects. There were no sex differences in the spatial extent of BOLD signal change for any ROI, but the signal amplitude was lower for women in most ROIs and significantly so for the primary somatosensory cortex (S1), the midanterior cingulate cortex, and the dorsolateral prefrontal cortex (DLPFC). The BOLD signal response could be positive or negative, and frequently, both polarities were observed within a single ROI. In most ROIs, women show proportionately more voxels with negative signal change than men, and this difference was statistically significant for the S1 and the DLPFC. The time course of the negative signal change was very similar to that of the positive signal change, suggesting that the latter was not “driving” the former. The location of negative and positive clusters formed distinct patterns in several of the ROIs, and these patterns suggest something other than a local “steal” phenomenon as an explanation for the negative signal changes. Sex differences in baseline cerebral blood flow may contribute to the BOLD signal differences observed in this study.
Photoperiodic regulation of insulin receptor mRNA and intracellular insulin signaling in the arcuate nucleus of the Siberian hamster,Phodopus sungorus
Authors: Tups Alexander , Helwig Michael , Stöhr Sigrid , Barrett Perry , Mercer Julian G. , Klingenspor Martin
Published: April 2006

During the last 5 years it has been well established that photoperiod-induced changes in body weight in the seasonal hamster, Phodopus sungorus, are accompanied by a marked seasonal cycle in leptin sensitivity. In the present study, we investigated the possible involvement of insulin signaling in seasonal body weight regulation. We analyzed the expression pattern and relative intensity of insulin receptor (IR), phosphatidylinositol 3-kinase (PI3-kinase), and protein tyrosine phosphatase 1B (PTP1B) mRNAs by in situ hybridization in the brains of juvenile female hamsters acclimated to either long- (LD) or short-day length (SD) for 8 wk, with or without superimposed food deprivation for 48 h. Furthermore, the hypothalamic concentration and distribution of phospho-AKT, a marker of PI3-kinase activity was determined by immunoblotting and immunohistochemistry. Eight weeks of acclimation to SD led to a substantial downregulation of IR, PTP1B gene expression, and phospho-AKT concentration in this brain region, whereas PI3-kinase mRNA was unchanged. Food deprivation induced a decrease in PTP1B and a trend toward lowered IR gene expression in LD but not in SD. Additionally, a striking increase in PTP1B gene expression in the thalamus was observed after food deprivation in both photoperiods. The direction of change in neuronal insulin signaling contrasts to the central catabolic nature of this pathway described in other species. SD-induced reduction in insulin signaling may be due to decline in body fat stores mediated by enhanced central leptin sensitivity. Increased anorexigenic tone of leptin may overwrite central insulin signaling to prevent catabolic overdrive.
Regulation of the epithelial Na+ channel (ENaC) by phosphatidylinositides
Authors: Pochynyuk Oleh , Tong Qiusheng , Staruschenko Alexander , Ma He-Ping , Stockand James D.
Published: April 2006

The epithelial Na+ channel (ENaC) is an end-effector of diverse cellular signaling cascades, including those with phosphatidylinositide second messengers. Recent evidence also suggests that in some instances, phospatidylinositides can directly interact with ENaC to increase channel activity by increasing channel open probability and/or membrane localization. We review here findings relevant to regulation of ENaC by phosphatidylinositol 4,5- bisphosphate (PIP2) and phosphatidylinositol 3,4,5-triphosphate (PIP3). Similar to its actions on other ion channels, PIP2 is permissive for ENaC openings having a direct effect on gating. The PIP2 binding site in ENaC involved in this regulation is most likely localized to the NH2 terminus of β-ENaC. PIP3 also affects ENaC gating but, rather than being permissive, augments open probability. The PIP3 binding site in ENaC involved in this regulation is localized to the proximal region of the COOH terminus of γ-ENaC just following the second transmembrane domain. In complementary pathways, PIP3 also impacts ENaC membrane levels through both direct actions on the channel and via a signaling cascade involving phosphoinositide 3-OH kinase (PI3-K) and the aldosterone-induced gene product serum and glucocorticoid-inducible kinase. The putative PIP3 binding site in ENaC involved in direct regulation of channel membrane levels has not yet been identified.
Autocrine VEGF-A system in podocytes regulates podocin and its interaction with CD2AP
Authors: Guan Fangxia , Villegas Guillermo , Teichman Jason , Mundel Peter , Tufro Alda
Published: April 2006

Vascular endothelial growth factor (VEGF-A) signaling is required for endothelial cell differentiation, vasculogenesis, angiogenesis, and vascular patterning. During kidney morphogenesis, podocyte VEGF-A guides endothelial cells toward developing glomeruli. Podocyte VEGF-A expression continues throughout life but its function after completion of development remains unclear. Here, we examined the expression of VEGF-A and its receptors VEGFR1, VEGFR2, NP1, and NP2 in conditionally immortalized mouse podocytes cultured in undifferentiated and differentiated conditions using RT-PCR and Western analysis. VEGF-A secretion was assessed by ELISA and Western analysis. Upon podocyte differentiation, VEGF-A protein expression and secretion increased threefold. Differentiated podocytes expressed eightfold higher VEGFR2 mRNA levels than undifferentiated podocytes, whereas VEGFR1, sVEGFR1, NP1, and NP2 mRNA levels were similar. We examined the regulation and function of the VEGF-A system by exposing differentiated podocytes to recombinant VEGF165(20 ng/ml) or control media for 24 h. VEGF165induced a twofold increase in VEGFR2 mRNA and protein levels, whereas VEGFR1, sVEGFR1, NP1, and NP2 mRNA levels remained unchanged. VEGF165induced VEGFR2 phosphorylation. VEGF165reduced podocyte apoptosis ∼40%, whereas anti-VEGFR2 neutralizing antibody enhanced it twofold. We determined that VEGF-A signaling regulates slit diaphragm proteins by inducing a dose-response podocin upregulation and increasing its interaction with CD2AP. The data indicate that podocytes in culture have a functional autocrine VEGF-A system that is regulated by differentiation and ligand availability. VEGF-A functions in podocytes include promoting survival through VEGFR2, inducing podocin upregulation and increasing podocin/CD2AP interaction.
Steep head-down tilt has persisting effects on the distribution of pulmonary blood flow
Authors: Henderson A. Cortney , Levin David L. , Hopkins Susan R. , Olfert I. Mark , Buxton Richard B. , Prisk G. Kim
Published: April 2006

Head-down tilt has been shown to increase lung water content in animals and alter the distribution of ventilation in humans; however, its effects on the distribution of pulmonary blood flow in humans are unknown. We hypothesized that head-down tilt would increase the heterogeneity of pulmonary blood flow in humans, an effect analogous to the changes seen in the distribution of ventilation, by increasing capillary hydrostatic pressure and fluid efflux in the lung. To test this, we evaluated changes in the distribution of pulmonary blood flow in seven normal subjects before and after 1 h of 30° head-down tilt using the magnetic resonance imaging technique of arterial spin labeling. Data were acquired in triplicate before tilt and at 10-min intervals for 1 h after tilt. Pulmonary blood flow heterogeneity was quantified by the relative dispersion (standard deviation/mean) of signal intensity for all voxels within the right lung. Relative dispersion was significantly increased by 29% after tilt and remained elevated during the 1 h of measurements after tilt (0.84 ± 0.06 pretilt, 1.09 ± 0.09 calculated for all time points posttilt, P < 0.05). We speculate that the mechanism most likely responsible for our findings is that increased pulmonary capillary pressures and fluid efflux in the lung resulting from head-down tilt alters regional blood flow distribution.
Subclasses of α‐spirallike functions associated with Ruscheweyh derivatives
Authors: Xu Neng , Yang Dinggong
Published: April 2006

Making use of the Ruscheweyh derivatives, we introduce the
subclasses T(n, α, λ)(n ∈ {0, 1, 2, 3, …}, −π/2 < α < π/2, and0 ≤ λ ≤ cos2α) of functions which are analytic in |z| < 1. Subordination and inclusion relations are
obtained. The radius of α‐spirallikeness of order ρ is calculated. A convolution property and a special member of T(n, α, λ) are also given.
A Voronovskaya‐type theorem for a positive linear operator
Authors: Ciupa Alexandra
Published: April 2006

We consider a sequence of positive linear operators which
approximates continuous functions having exponential growth at
infinity. For these operators, we give a Voronovskaya‐type
theorem
On the uncertainty inequality as applied to discrete signals
Authors: Venkatesh Y. V. , Raja S. Kumar , Vidyasagar G.
Published: April 2006

Given a continuous‐time bandlimited signal, the Shannon sampling theorem provides an interpolation scheme for exactly reconstructing it from its discrete samples. We analyze the relationship between concentration (or compactness) in the temporal/spectral domains of the (i) continuous‐time and (ii) discrete‐time signals. The former is governed by the Heisenberg uncertainty inequality which prescribes a lower bound on the product of effective temporal and spectral spreads of the signal. On the other hand, the discrete‐time counterpart seems to exhibit some strange properties, and this provides motivation for the present paper. We consider the following problem: for a bandlimited signal, can the uncertainty inequality be expressed in terms of the samples, using thestandard definitions of the temporal and spectral spreads of the signal? In contrast with the results of the literature, we present a new approach to solve this problem. We also present a comparison of the results obtained using the proposed definitions with those available in the literature.
Remarks on weak solutions for a nonlocal parabolic problem
Authors: de Menezes S. B.
Published: April 2006

We prove a result on existence and uniqueness of weak solutions
for a diffusion problem associated with nonlinear diffusions of
nonlocal type studied by Chipot and Lovat (1999) by an
application of the fixed point result of Schauder. Moreover,
making use of Faedo‐Galerkin approximation, coupled with some
technical ideas, we establish a result on existence of periodic
solution.
Inversion formulas for Riemann‐Liouville transform and its dual associated with singular partial differential operators
Authors: Baccar C. , Hamadi N. B. , Rachdi L. T.
Published: April 2006

We define Riemann‐Liouville transform ℛα and its dual  tℛα associated with two singular partial
differential operators. We establish some results of harmonic
analysis for the Fourier transform connected with
ℛα. Next, we prove inversion formulas for the
operators ℛα,  tℛα and a Plancherel theorem for  tℛα.
Explicit inverse of the Pascal matrix plus one
Authors: Yang Sheng-liang , Liu Zhong-kui
Published: April 2006

This paper presents a simple approach to invert the matrix Pn + In by applying the Euler polynomials and Bernoulli numbers,
where Pn is the Pascal matrix.
Subordination properties of P‐valent functions defined by integral operators
Authors: Shams Saeid , Kulkarni S. R. , Jahangiri Jay M.
Published: April 2006

By applying certain integral operators to P‐valent functions we define a comprehensive family of analytic functins. The
subordinations properties of this family is studied, which in
certain special cases yield some of the previously obtained
results.
1′-Acetoxychavicol Acetate Inhibits RANKL–Induced Osteoclastic Differentiation of RAW 264.7 Monocytic Cells by Suppressing Nuclear Factor-κB Activation
Authors: Ichikawa Haruyo , Murakami Akira , Aggarwal Bharat B.
Published: April 2006

Osteoclastogenesis is commonly associated with various age-related diseases, including cancer. A member of the tumor necrosis factor superfamily, receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL), has been shown to play a critical role in osteoclast formation and bone resorption. Thus, agents that suppress RANKL signaling have a potential to suppress bone loss. In this report, we investigated the effect of 1′-acetoxychavicol acetate (ACA), a component of Alpina galanga, on RANKL signaling and consequent osteoclastogenesis in RAW 264.7 cells, a murine monocytic cell line. Treatment of these cells with RANKL activated NF-κB, and coexposure of the cells to ACA completely suppressed RANKL-induced NF-κB activation in a time- and concentration-dependent manner. The suppression of NF-κB by ACA was mediated through suppression of RANKL-induced activation of IκBα kinase, IκBα phosphorylation, and IκBα degradation. Furthermore, incubation of monocytic cells with RANKL induced osteoclastogenesis, and ACA suppressed it. Inhibition of osteoclastogenesis was maximal when cells were simultaneously exposed to ACA and RANKL and minimum when ACA was added 2 days after RANKL. ACA also inhibited the osteoclastogenesis induced by human breast cancer MCF-7 cells, multiple myeloma MM1 cells, and head and neck squamous cell carcinoma LICR-LON-HN5 cells. These results indicate that ACA is an effective blocker of RANKL-induced NF-κB activation and of osteoclastogenesis induced by RANKL and tumor cells, suggesting its potential as a therapeutic agent for osteoporosis and cancer-associated bone loss. (Mol Cancer Res 2006;4(4):275–81)
Economic Evaluation of the Familial Cancer Programme in Western Australia: Predictive Genetic Testing for Familial Adenomatous Polyposis and Hereditary Non-Polyposis Colorectal Carcinoma
Authors: Breheny N. , Geelhoed E. , Goldblatt J. , Ee H. , O’Leary P.
Published: April 2006

Aim: To evaluate costs and outcomes of genetic testing for familial colorectal cancer through services provided by Genetic Services of Western Australia (GSWA). Methods: Costs and outcomes of predictive DNA-based testing for inherited colorectal cancers (CRC) were assessed, specifically for familial adenomatous polyposis (FAP) and hereditary non-polyposis CRC (HNPCC) using a decision-analysis model. Costs were assigned according to standards of care in Western Australia (WA). Cancer risks and the efficacy of surveillance on long-term outcomes were derived from the published literature. Results: The cost-effectiveness of genetic testing was compared in first-degree relatives of known mutation carriers who have a 50% risk of carrying the mutated gene (intervention group) to individuals with the same risk but who do not undergo a genetic test (control subjects). Compared with control subjects undergoing the same high-level surveillance and surgery, the FAP and HNPCC intervention groups provided total savings of $ 13,390 and 14,783–15,460 per person (males-females), respectively. HPNCC mutation carriers also gained 1 CRC-free year. Compared to control subjects having only population surveillance, individuals in the FAP intervention group delayed the onset of CRC by 40 years for a net cost of $ 9,042. Individuals in the HNPCC intervention group delayed the onset of CRC by 8 years at a net cost of $ 12,141 for males and $ 12,596 for females. Conclusions: Genetic testing for familial CRC in WA allows targeted surveillance for mutation carriers, which ensures the efficient use of resources and reduces cancer-related morbidity, if clinical recommendations for intervention are adopted.
Assessment of a Pioneer Metabolic Information Service in Brazil
Authors: Brustolin Silvia , Souza Carolina , Puga Ana Cristina , Refosco Lilia , Pires Ricardo , Peres Rossana , Giugliani Roberto
Published: April 2006

The Information Service on Inborn Errors of Metabolism (SIEM), a pioneer toll-free service in both Brazil and South America, is based in Porto Alegre, Southern Brazil. SIEM has been operating since October 2001 providing support to health care professionals involved in the diagnosis and management of suspected metabolic diseases. We analyzed the demographic and clinical characteristics of the 376 consults received and followed in the first two and half years of SIEM. Our results show that the suspicion of a metabolic disease was most often associated with neurological symptoms. Among the consults, 24.4% were eventually confirmed as inborn errors of metabolism (IEM), with organic acidurias and amino acid disorders being the two most frequent diagnostic groups. Our conclusion shows this kind of service to provide helpful support to the diagnosis and acute management of IEM, especially to health professionals working in developing countries who are often far from reference centers.
Changes in Metalloproteinase and Tissue Inhibitor of Metalloproteinase during Tachycardia-Induced Cardiomyopathy by Rapid Atrial Pacing in Dogs
Authors: Zhong Jing-quan , Zhang Wei , Li Yan , Zhong Ming , Li Duoling , Zhang Cheng , Zhang Yun
Published: April 2006

Background: It was the aim of this study to investigate the variation in metalloproteinase and tissue inhibitor of metalloproteinase (TIMP) connexin levels during tachycardia-induced cardiomyopathy (TIC). Methods: Canine models of TIC were established by rapid right atrial pacing at 350–400 beats per min for 8 weeks in 11 dogs, with another 6 dogs acting as sham operation group. Echocardiography, left ventricular pressure and its first derivation with time (positive and negative maximum, dp/dtmax and –dp/dtmax), as well as intracardiac electrograms were recorded before and after rapid pacing at 1, 4 and 8 weeks. Data were acquired in sinus rhythm. Ultrastructural changes in left ventricular tissue were observed by transmission electron microscope. The relative abundance of matrix metalloproteinase (MMP)-9 and TIMP-1 was studied by immunoblotting. Results: The following hemodynamic changes were detected after 8 weeks of rapid pacing: the TIC group had decreased dp/dtmax (p < 0.05), the left ventricular relaxation time constant (τ) was prolonged (p < 0.05), both left ventricular end-diastolic volume and left ventricular end-systolic volume were decreased (p <0.05), left ventricular end-diastolic pressure was significantly increased (p <0.05), and –dp/dtmax was significantly decreased (p <0.001) compared with the control group; no statistical differences in the left ventricular ejection fraction between weeks 1, 4 or 8 (p >0.05) were observed, but left ventricular ejection fraction was significantly decreased after 1 week of pacing (p < 0.05). The left ventricular end-diastolic volume was increased after 1 week of pacing compared with the control group (24.15 ± 8.15 vs.11.19 ± 4.41 ml; p <0.05), as shown by echocardiography. Compared with the control group, MMP-9 was significantly higher (0.217 ± 2.16 E-02 vs. 0.314 ± 5.263 E-02; p < 0.001), while TIMP-1 was decreased (0.230 ± 8.944 E-02 vs. 0.120 ± 9.258 E-03; p < 0.001). Conclusions: Ventricular dilatation and systolic dysfunction occurred after 1 week of rapid right atrial pacing. Enlarged and disarrayed fibers and mitochondria with disintegrated crystal and an anarchic pattern were observed. Additionally, moderate dilation of the rough endoplasmic reticulum and intercalated disk discontinuity were seen after 8 weeks of pacing, and MMP-9 was increased and TIMP-1 was decreased after the same time period.
Prediction of Empirical p Values from Asymptotic p Values for Conditional Logistic Affected Relative Pair Linkage Analysis
Authors: Sinha Moumita , Song Yeunjoo , Elston Robert C. , Olson Jane M. , Goddard Katrina A.B.
Published: April 2006

Objective: p Values are inaccurate for model-free linkage analysis using the conditional logistic model if we assume that the LOD score is asymptotically distributed as a simple mixture of chi-square distributions. When analyzing affected relative pairs alone, permuting the allele sharing of relative pairs does not lead to a useful permutation distribution. As an alternative, we have developed regression prediction models that provide more accurate p values. Methods: Let Eα be the empirical p value, which is the proportion of statistical tests whose LOD score under the null hypothesis exceeds a threshold determined by α, the nominal single test significance value. We used simulated data to obtain values of Eα and compared them with α. We also developed a regression model, based on sample size, number of covariates in the model, α and marker density, to derive predicted p values for both single-point and multipoint analyses. To evaluate our predictions we used another set of simulated data, comparing the Eα for these data with those obtained by using the prediction model, referred to as predicted p values (Pα). Results: Under almost all circumstances the values of Pα were closer to the Eα than were the values of α. Conclusion: The regression models suggested by our analysis provide more accurate alternative p values for model-free linkage analysis when using the conditional logistic model.
C-Reactive Protein Predicts Vascular Access Thrombosis in Hemodialysis Patients
Authors: Chou Che-Yi , Kuo Huey-Liang , Yung Ya-Fei , Liu Yao-Lung , Huang Chiu-Ching
Published: April 2006

Background: Vascular access thrombosis (VAT) is one of the most common morbidity in hemodialysis patients. The development of arteriovenous fistula thrombosis is associated with vascular intimal hyperplasia. Some studies suggested that serum C-reactive protein (CRP) predicts the development of vascular intima hyperplasia that conduces vascular access stenosis and thrombosis. This study aimed to access the clinical usefulness of CRP in predicting VAT in hemodialysis patients. Methods: We retrospectively reviewed all prevalent hemodialysis patients with native arteriovenous fistula (nAVF) between November 2001 and November 2004. The CRP levels and relation to the development of VAT was analyzed with Kaplan-Meier analysis in four groups of patients divided according to their serum CRP levels. Besides serum CRP levels, other factors possibly influencing vascular access thrombosis were also considered: gender, age, diabetes, aspirin, smoking, statin, serum albumin, hematocrit, cholesterol >200 mg/dl, Calcium-phosphate product, and intact parathyroid hormone >200 pg/ml. Results: We retrospectively reviewed 223 chronic hemodialysis patients. 198 patients with forearm nAVF and 25 with upper arm nAVF were included. Of the above 223 patients, 51 experienced one or more VAT episodes. In Kaplan-Meier survival analysis, patients with serum CRP levels >0.8 mg/dl were prone to develop VAT (log-rank, p < 0.001). In a multivariate Cox regression model, serum CRP greater than 0.8mg/dl was confirmed to be an independent predictor of VAT with a relative risk of 16.6 times (95% CI, 7.85–35.1). The area under the receiver operator characteristic (ROC) curve of CRP >0.8 mg/dl in predicting VAT events is 0.785 (95% CI, 0.712–0.858; p < 0.001). Sensitivity and specificity of CRP (>0.8 mg/dl) in predicting VAT were 80.4 and 72.7%. Conclusions: The serum CRP levels not only predict cardiovascular disease and mortality in hemodialysis patients but also predict the development of vascular access thrombosis in chronic hemodialysis patients.
The Endocannabinoid System: A New Player in the Neurochemical Control of Vestibular Function?
Authors: Smith Paul F. , Ashton John C. , Darlington Cynthia L.
Published: April 2006

The results of recent clinical trials of medicinal cannabinoid drugs show that dizziness and vertigo are commonly reported adverse side-effects. Cannabinoid CB1 receptors were initially thought to be expressedin very low densities in the vestibular nucleus complex (VNC). Recent immunohistochemical studies have challenged this idea and suggested that CB1 receptors may exist in numbers similar to the granule cell layer of the cerebellum. This, together with evidence that brainstem CB1 receptors have a higher efficacy than those in many other parts of the brain and that application of cannabinoids can elicit potent electrophysiological effects in VNC neurons, suggests that CB1 receptors and their endogenous ligands may be important in central vestibular function. In this review, we consider the potential clinical significance of the endocannabinoid system for the development of vestibular disorders, the effects of recreational cannabis use and the therapeutic use of medicinal cannabinoids.
Thermal Behaviour of Human Stratum Corneum
Authors: Silva C.L. , Nunes S.C.C. , Eusébio M.E.S. , Pais A.A.C.C. , Sousa J.J.S.
Published: April 2006

Purpose: To use high-speed differential scanning calorimetry (DSC) in the identification of transitions in human stratum corneum (SC). Several scanning rates (100°C/min to 400°C/min) are used. Results: Eight transitions from 0 to 120°C are detected in a significant number of samples. Most of these transitions have already been identified in previous studies, but have been labeled considering essentially that only four are present. Results also indicate some degree of reversibility for transitions occurring at temperatures above 90°C. Dehydrated SC samples displayed slightly more defined transition peaks and a less frequent presence of the transitions below 50°C. In turn, the delipidised SC matrix showed two major endothermic signals, centered around 55 and 100°C, in conjunction with other much less marked features. Conclusions: The interpretation of DSC traces in terms of four main transition temperatures must be complemented having in mind the occurrence of other transitions, some of them at physiological temperatures. This work further suggests that transitions at temperatures above 90°C may to a large degree be associated to lipids, while transition at approx. 55°C is probably related to lipids covalently linked to proteins, as previously suggested.
Evaluation of Body Fat Changes during Weight Loss by Using Improved Anthropometric Predictive Equations
Authors: García Ada L. , Wagner Karen , Einig Christiana , Trippo Ulrike , Koebnick Corinna , Zunft Hans-Joachim F.
Published: April 2006

Background/Aim: Skinfold-based equations are widely used to evaluate body fat (BF), but over-/underestimation is often reported. We evaluate the capacity of improved skinfold-based equations to estimate BF changes during weight reduction and compare them against well-established equations. Methods: Overweight adults (n = 44) participated in a 4-month weight reduction intervention. Dual-energy X-ray absorptiometry (DXA) and anthropometric measurements were taken at baseline and after intervention. The BF% was calculated using García, Peterson, and Durnin and Womersley (DW) equations. Results: Baseline and postintervention BF% measured by DXA correlated highest with BF% predicted according to García (r = 0.934 and r = 0.948, respectively), followed by Peterson (r = 0.941 and r = 0.932, respectively) and DW (r = 0.557 and r = 0.402, respectively); only a slight systematic error in overestimating the BF% was observed in estimates according to García (r = 0.147 and r = 0.104, respectively; p < 0.001), while increasing errors occurred using the Peterson (r = 0.624 and r = 0.712, respectively; p < 0.001) and DW (r = 0.767 and r = 0.769, respectively; p < 0.001) equations. Moderate correlations between BF changes (kg) measured by DXA and predicted by DW (r = 0.7211), Peterson (r = 0.697), and García (r = 0.645) were observed. Conclusion: Improved skinfold equations cannot accurately measure changes in BF after weight reduction.
Propylene Glycol Today
Authors: Vilaplana J. , Alsina M. , Coll J. , Reig J.M. , Campos G. , Trullas C. , Pelejero C. , Recasens M. , Costa D. , Romaguera C.
Published: April 2006

Propylene glycol (PG) has been described as responsible for contact allergy and irritant reactions, but there are a lot of non-conclusive studies reporting a different percentage of patients irritated, with diverse concentrations and doses applied. As this substance is contained in a large amount of products, we reviewed its irritant capacity and the appropriate concentration to be tested. PG from two different origins was tested in 230 healthy volunteers. We applied 25 µl of PG at two different concentrations (70 and 100%). PG from origin B (PGB) was tested furthermore with two different qualities. Biophysical measurements were performed in those subjects patch-tested with PGB and its acute dermal irritation was tested in human skin culture. After 48 h results did not show any difference between PG from both origins and qualities. After 96 h PGB was slightly more irritant than PGA. Biophysical measurements only increased significantly in the subjects with a positive allergic reaction and there were no differences in the in vitro test. PG is not valid as pattern of irritation even at 100% concentration because it irritates a small percentage of patients. The recommended concentration should be between 30 and 70% in water, and the 100% concentration could be used in non-reactive patients.
Perivascular Adipose Tissue and Mesenteric Vascular Function in Spontaneously Hypertensive Rats
Authors: Gálvez Beatriz , de Castro Javier , Herold Diana , Dubrovska Galyna , Arribas Silvia , González M. Carmen , Aranguez Isabel , Luft Friedrich C. , Ramos M. Pilar , Gollasch Maik , Fernández Alfonso Maria S.
Published: April 2006

Objective—

Perivascular adipose tissue of normotensive rats releases a transferable factor that induces relaxation by opening voltage-dependent K
+
(K
v
) channels. The relevance of these observations to hypertension is unknown.

Methods and Results—

We characterized mesenteric perivascular adipose tissue from 3-month-old Wistar Kyoto rats (WKY) and aged-matched spontaneously hypertensive rats (SHR). Mesenteric bed (MB) weight and MB total lipid content were lower in SHR than in WKY. Freshly isolated MB adipocytes were smaller in SHR. Plasma triglycerides, glycerol, nonesterified free-fatty acids, and cholesterol were also lower in SHR. Plasma and mesenteric leptin were correlated with the quantity of mesenteric fat. To study vascular function, the MB was cannulated and perfused at a constant 2 mL/min flow. The K
v
channel blocker 4-aminopyridine (4-AP; 2 mmol/L) increased perfusion pressure less in SHR MB than WKY and was directly correlated with the mesenteric fat amount. In isolated mesenteric artery rings, 4-AP (2 mmol/L) induced a contractile effect that was attenuated in SHR compared with WKY. The anticontractile effects of perivascular fat were reduced in SHR mesenteric artery rings compared with WKY.

Conclusions—

Differences in visceral perivascular adipose tissue mass and function may contribute to the increased vascular resistance observed in SHR.
Molecular Mechanisms of Vascular Calcification
Authors: Shao Jian-Su , Cai Jun , Towler Dwight A.
Published: April 2006

Vascular calcification increasingly afflicts our aging and dysmetabolic population. Once considered a passive process, it has emerged as an actively regulated form of calcified tissue metabolism, resembling the mineralization of endochondral and membranous bone. Executive cell types familiar to bone biologists, osteoblasts, chondrocytes, and osteoclasts, are seen in calcifying macrovascular specimens. Lipidaceous matrix vesicles, with biochemical and ultrastructural “signatures” of skeletal matrix vesicles, nucleate vascular mineralization in diabetes, dyslipidemia, and uremia. Skeletal morphogens (bone morphogenetic protein-2 (BMP) and BMP4 and Wnts) divert aortic mesoangioblasts, mural pericytes (calcifying vascular cells), or valve myofibroblasts to osteogenic fates. Paracrine signals provided by these molecules mimic the epithelial–mesenchymal interactions that induce skeletal development. Vascular expression of pro-osteogenic morphogens is entrained to physiological stimuli that promote calcification. Inflammation, shear, oxidative stress, hyperphosphatemia, and elastinolysis provide stimuli that: (1) promote vascular BMP2/4 signaling and matrix remodeling; and (2) compromise vascular defenses that limit calcium deposition, inhibit osteo/chondrogenic trans-differentiation, and enhance matrix vesicle clearance. In this review, we discuss the biology of vascular calcification. We highlight how aortic fibrofatty tissue expansion (adventitia, valve interstitium), the adventitial-medial vasa, vascular matrix, and matrix vesicle metabolism contribute to the regulation of aortic calcium deposition, with greatest emphasis placed on diabetic vascular disease.
Secretory Phospholipase A2Group V
Authors: Rosengren Birgitta , Peilot Helena , Umaerus Mia , Jönsson-Rylander Ann-Cathrine , Mattsson-Hultén Lillemor , Hallberg Carina , Cronet Philippe , Rodriguez-Lee Mariam , Hurt-Camejo Eva
Published: April 2006

Objective—To study the distribution of group V secretory phospholipase A2(sPLA2) in human and mouse lesions and compare its expression by human vascular cells, its activity toward lipoproteins, and the interaction with arterial proteoglycans (proteoglycans) with those of sPLA2-IIA. In addition, we also investigated the effect of a Western diet and lipopolysaccharide challenge on the aortic expression of these enzymes in mouse models.

Methods and Results—Immunohistochemistry showed sPLA2-V in human and mouse lesions to be associated with smooth muscle cells and also surrounding foam cells in lipid core areas. mRNA of the enzyme was expressed in human lesions and human vascular cells, supporting the immunohistochemistry data. sPLA2-V but not sPLA2-IIA was active on lipoproteins in human serum. The association with proteoglycans enhanced 2- to 3-fold sPLA2-V activity toward low-density lipoproteins but not that of the group IIA enzyme. Experiments in mouse models showed that treatment with a Western diet induced expression of sPLA2-V but not that of sPLA2-IIA in aorta. On the other hand, lipopolysaccharide-induced acute inflammation augmented the expression of sPLA2-IIA but not that of sPLA2-V.

Conclusions—These results indicate that these phospholipases could have different roles in atherosclerosis.
Caveolin Plays a Central Role in Endothelial Progenitor Cell Mobilization and Homing in SDF-1–Driven Postischemic Vasculogenesis
Authors: Sbaa Elhem , DeWever Julie , Martinive Philippe , Bouzin Caroline , Frérart Françoise , Balligand Jean-Luc , Dessy Chantal , Feron Olivier
Published: April 2006

When neovascularization is triggered in ischemic tissues, angiogenesis but also (postnatal) vasculogenesis is induced, the latter requiring the mobilization of endothelial progenitor cells (EPC) from the bone marrow. Caveolin, the structural protein of caveolae, was recently reported to directly influence the angiogenic process through the regulation of the vascular endothelial growth factor (VEGF)/nitric oxide pathway. In this study, using caveolin-1 null mice (Cav
−/−
), we examined whether caveolin was also involved in the EPC recruitment in a model of ischemic hindlimb. Intravenous infusion of Sca-1
+
Lin
−
progenitor cells, but not bone marrow transplantation, rescued the defective neovascularization in Cav
−/−
mice, suggesting a defect in progenitor mobilization. The adhesion of Cav
−/−
EPC to bone marrow stromal cells indeed appeared to be resistant to the otherwise mobilizing SDF-1 (
S
tromal cell–
D
erived
F
actor-
1
) exposure because of a defect in the internalization of the SDF-1 cognate receptor CXCR4. Symmetrically, the attachment of Cav
−/−
EPC to SDF-1–presenting endothelial cells was significantly increased. Finally, EPC transduction with caveolin small interfering RNA reproduced this advantage in vitro and, importantly, led to a more extensive rescue of the ischemic hindlimb after intravenous infusion (versus sham-transfected EPC). These results underline the critical role of caveolin in ensuring the caveolae-mediated endocytosis of CXCR4, regulating both the SDF-1–mediated mobilization and peripheral homing of progenitor cells in response to ischemia. In particular, a transient reduction in caveolin expression was shown to therapeutically increase the engraftment of progenitor cells.
T Cell Recognition and Killing of Vascular Smooth Muscle Cells in Acute Coronary Syndrome
Authors: Pryshchep Sergey , Sato Kayoko , Goronzy Jörg J. , Weyand Cornelia M.
Published: April 2006

Loss of vascular smooth muscle cells (VSMCs) has been proposed to destabilize the atherosclerotic plaque and contribute to plaque rupture, superimposed thrombosis, and acute coronary syndromes (ACSs). We examined whether VSMCs are susceptible to T cell–induced apoptosis and found that CD4 T cells are highly effective in establishing cell–cell contact with VSMCs and triggering apoptotic death. Visualization of the T cell–VSMC contact zone on the single-cell level revealed that both patient-derived and control CD4 T cells reorganized their cell membrane to assemble an immunologic synapse with the VSMCs. Within 4 to 10 minutes, the membrane proximal signaling molecule ZAP-70 was recruited and phosphorylated. However, only patient-derived CD4 T cells sustained an intact immunologic synapse beyond 10 minutes and generated intracellular calcium signals. CD4 T cells that maintained a synaptic contact and appeared to be responsible for VSMC apoptosis accounted for approximately 20% of the circulating memory T cell population in ACS patients and were rare in the blood of age-matched controls. CD4 T cells from ACS patients were also hyperresponsive to T cell receptor–mediated stimulation when triggered by a superantigen and non-VSMC target cells. Lowered setting of the T cell activation threshold, attributable to excessive amplification of proximal CD3-mediated signals, may contribute to CD4 T cell-mediated killing of VSMCs and promote plaque instability.
Gene Expression Profile Signatures Indicate a Role for Wnt Signaling in Endothelial Commitment From Embryonic Stem Cells
Authors: Wang Hong , Charles Peter C. , Wu Yaxu , Ren Rongqin , Pi Xinchun , Moser Martin , Barshishat-Kupper Michal , Rubin Jeffrey S. , Perou Charles , Bautch Victoria , Patterson Cam
Published: April 2006

We have used global gene expression analysis to establish a comprehensive list of candidate genes in the developing vasculature during embryonic (ES) cell differentiation in vitro. A large set of genes, including growth factors, cell surface molecules, transcriptional factors, and members of several signal transduction pathways that are known to be involved in vasculogenesis or angiogenesis, were found to have expression patterns as expected. Some unknown or functionally uncharacterized genes were differentially regulated in flk1
+
cells compared with flk1
−
cells, suggesting possible roles for these genes in vascular commitment. Particularly, multiple components of the Wnt signaling pathway were differentially regulated in flk1
+
cells, including Wnt proteins, their receptors, downstream transcriptional factors, and other components belonging to this pathway. Activation of the Wnt signal was able to expand vascular progenitor populations whereas suppression of Wnt activity reduced flk1
+
populations. Suppression of Wnt signaling also inhibited the formation of matured vascular capillary-like structures during late stages of embryoid body differentiation. These data indicate a requisite and ongoing role for Wnt activity during vascular development, and the gene expression profiles identify candidate components of this pathway that participate in vascular cell differentiation.
AT
1
Receptor Blockade Regulates the Local Angiotensin II System in Cerebral Microvessels From Spontaneously Hypertensive Rats
Authors: Zhou Jin , Pavel Jaroslav , Macova Miroslava , Yu Zu-Xi , Imboden Hans , Ge Linna , Nishioku Tsuyoshi , Dou Jingtao , Delgiacco Elizabeth , Saavedra Juan M.
Published: April 2006

Background and Purpose—

Blockade of angiotensin II AT
1
receptors in cerebral microvessels protects against brain ischemia and inflammation. In this study, we tried to clarify the presence and regulation of the local renin-angiotensin system (RAS) in brain microvessels in hypertension.

Methods—

Spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) controls were treated with an AT
1
receptor antagonist (candesartan, 0.3 mg/kg per day) via subcutaneous osmotic minipumps for 4 weeks. The expression and localization of RAS components and the effect of AT
1
receptor blockade were assessed by Affymetrix microarray, qRT-PCR, Western blots, immunohistochemistry and immunofluorescence.

Results—

We found transcripts of most of RAS components in our microarray database, and confirmed their expression by qRT-PCR. Angiotensinogen (Aogen), angiotensin-converting enzyme (ACE) and AT
1
receptors were localized to the endothelium. There was no evidence of AT
2
receptor localization in the microvascular endothelium. In SHR, (pro)renin receptor mRNA and AT
1
receptor mRNA and protein expression were higher, whereas Aogen, ACE mRNA and AT
2
receptor mRNA and protein expression were lower than in WKY rats. Candesartan treatment increased Aogen, ACE and AT
2
receptor in SHR, and increased ACE and decreased Aogen in WKY rats, without affecting the (pro)renin and AT
1
receptors.

Conclusions—

Increased (pro)renin and AT
1
receptor expression in SHR substantiates the importance of the local RAS overdrive in the cerebrovascular pathophysiology in hypertension. AT
1
receptor blockade and increased AT
2
receptor stimulation after administration of candesartan may contribute to the protection against brain ischemia and inflammation.
Health-Related Quality of Life Among Young Adults With Ischemic Stroke on Long-Term Follow-Up
Authors: Naess Halvor , Waje-Andreassen Ulrike , Thomassen Lars , Nyland Harald , Myhr Kjell-Morten
Published: April 2006

Background and Purpose—

We sought to compare health-related quality of life (HRQoL) in young adults with ischemic stroke on long-term follow-up with controls and to evaluate HRQoL in clinically relevant patient subgroups.

Methods—

HRQoL was determined with the use of the 8 subscales of the Short-Form General Health Survey (SF-36). Subgroups of patients were defined by sex, age, functional status (modified Rankin Scale), marital status, education, depression (Montgomery-Åsberg Depression Rating Scale), and fatigue (Fatigue Severity Scale). SF-36 scores among patients were compared with SF-36 scores among age- and sex-matched controls and SF-36 scores available from the general Norwegian population.

Results—

SF-36 scores were obtained after a mean follow-up of 6.0 years among 190 young adults with ischemic stroke during 1988–1997 and among 215 responding controls (55%). The difference in HRQoL between patients, controls, and the general Norwegian population was restricted mainly to the 3 subscales physical functioning, general health, and social functioning (
P
<0.001). Subgroup analysis showed significantly reduced scores for all SF-36 items among patients who were depressed, suffered from fatigue, or unemployed. Linear regression analysis showed that fatigue and depression were major independent variables correlated with low HRQoL.

Conclusions—

Compared with controls and the general Norwegian population, low level of HRQoL among young adults with ischemic stroke was most pronounced in regard to physical functioning. Early identification and treatment of depression, fatigue, and physical disability may potentially improve HRQoL among stroke patients.
Large-Eddy Simulation of Air Parcels in Stratocumulus Clouds: Time Scales and Spatial Variability
Authors: Kogan Yefim L.
Published: April 2006

Large ensembles of air parcel trajectories driven by the (large-eddy simulation) LES-generated velocity fields from simulations of stratocumulus clouds were analyzed, focusing on statistics of air parcel in-cloud time scales, as well as their spatial variability. In the case of a drizzling stratocumulus cloud the in-cloud residence time is 2–5 times longer than the characteristic cloud eddy turnover time. About 70% of all air parcels cycle in the cloud more than 2 times and about 50% more than 3 times, thus indicating that air cycling is an essential feature of drizzling stratocumulus cloud dynamics. The extent of cycling is different in the case of nondrizzling stratocumulus cloud, where mean in-cloud time scales are on the order of eddy turnover time. Evidently air cycling in cloud depends on boundary layer stability and flow circulation; the latter is affected by cooling of evaporating drizzle and heating by solar radiation.

Results show significant inhomogeneity of in-cloud time scales, which leads to inhomogeneity in cloud microphysical parameters. The potential effects of in-cloud residence time spatial inhomogeneity on cloud microstructure are obvious and significant. Older parcels will contain larger droplets and previously processed cloud condensation nuclei (CCN). Nonadiabatic mixing between old and new parcels provides new embryos for coagulation and accelerates drizzle formation. It is hypothesized that mixing of parcels with different histories, that is, with drop size distributions at different stages of their evolution, may contribute to the drop spectrum broadening. The results also suggest a possible positive feedback mechanism between drizzle and decoupling, namely, parcels with long time trajectories will favor enhanced drizzle growth, which, in turn, will lead to stronger evaporation below cloud base followed by a stronger increase in stability of the subcloud layer and stronger decoupling; all resulting in more air parcel cycling in cloud and more drizzle, which may eventually lead to stratocumulus cloud breakup.
Laser pressure welding of Al alloy and low C steel
Authors: Nishimoto K. , Fujii H. , Katayama S.
Published: April 2006

This study was performed to obtain fundamental knowledge concerning the development of laser pressure welding technology for the joining of dissimilar metals. Laser pressure welding of Al alloy A6061 and low C steel SPCC sheets was carried out to investigate the effects of the roller pressure, laser beam scanning speed and irradiation position on the tensile shear and peel strength of welded joints. The interfaces of the joints were observed and analysed by SEM and EDX, and the formation phases on the peeled surfaces were identified with XRD. It was revealed that prevention and suppression of oxidation during welding was extremely important to the production of a sound joint with good mechanical properties. The highest tensile strength and the highest peel strength of joints were obtained at a laser power of 1·8 kW, laser scanning speed of 30 Hz, laser irradiation position at the centreline, roller pressure of more than 245 MPa and welding speed of 0·5 m min−1 in an Ar atmosphere. The fracture occurred not in the welded zone but in the A6061 base alloy specimen.