bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognostic Implications of Warfarin Cessation After Major Trauma
Authors: Hackam Daniel G. , Kopp Alexander , Redelmeier Donald A.
Published: April 2005

Background—

Warfarin therapy is often withheld from elderly patients who fall or otherwise experience injury because of concerns regarding the long-term risk of hemorrhage in these individuals. We studied whether stopping warfarin after trauma is associated with a higher risk of subsequent adverse cardiovascular events.

Methods and Results—

We conducted a retrospective, population-based, cohort study using linked administrative databases in the province of Ontario, Canada for the years 1992 to 2001. A total of 8450 elderly patients (age >65 years) who survived an incident of major trauma and were receiving warfarin before injury were followed up for a mean of 3.3 years. During the 6-month interval after trauma, 1827 (22%) patients discontinued warfarin, whereas 6623 (78%) patients continued warfarin. Warfarin cessation was not associated with an increased risk of subsequent stroke (hazard ratio [HR] 0.99, 95% CI 0.82 to 1.21) or myocardial infarction (HR 0.94, 95% CI 0.74 to 1.20) but was associated with a lower risk of major hemorrhage (HR 0.69, 95% CI 0.54 to 0.88) and a higher risk of venous thromboembolism (HR 1.59, 95% CI 1.07 to 2.36). Adjustment for baseline demographics, stroke risk factors, other comorbidities, and characteristics of the trauma did not materially change these findings. On-treatment analyses yielded similar results.

Conclusions—

Cessation of warfarin in elderly patients after major trauma was not associated with an increased risk of arterial thrombotic events but was associated with a significantly increased risk of venous thromboembolism.
Rise in Insulin Resistance Is Associated With Escalated Telomere Attrition
Authors: Gardner Jeffrey P. , Li Shengxu , Srinivasan Sathanur R. , Chen Wei , Kimura Masayuki , Lu Xiaobin , Berenson Gerald S. , Aviv Abraham
Published: April 2005

Background—

Insulin resistance predisposes to cardiovascular disease and shortens human lifespan. We therefore tested the hypothesis that a rise in insulin resistance in concert with gain in body mass is associated with accelerated white blood cell telomere attrition.

Methods and Results—

We measured white blood cell telomere dynamics and age-related changes in insulin resistance and body mass index in young adults of the Bogalusa Heart Study. Over 10.1 to 12.8 years, the relative changes in telomere length were correlated with the homeostasis model assessment of insulin resistance (
r
=−0.531,
P
<0.001) and changes in the body mass index (
r
=−0.423,
P
<0.001).

Conclusions—

These findings provide the first tangible nexus of telomere biology with insulin resistance and adiposity in humans.
Effects of High Thoracic Epidural Analgesia on Myocardial Blood Flow in Patients With Ischemic Heart Disease
Authors: Nygård Eigil , Kofoed Klaus F. , Freiberg Jacob , Holm Søren , Aldershvile Jan , Eliasen Kirsten , Kelbæk Henning
Published: April 2005

Background—

In patients with ischemic heart disease, high thoracic epidural analgesia (TEA) has been proposed to improve abnormalities of coronary function by inhibiting cardiac sympathetic tone. We evaluated the effect of TEA on myocardial blood flow in patients with ischemic heart disease.

Methods and Results—

Twenty male patients with multivessel ischemic heart disease were studied. An epidural catheter was inserted between the second and third thoracic vertebral interspace (Th2 to Th3). Analgesia was induced by epidural injection of bupivacaine 0.5%, and a sensory block from the sixth cervical (C6 to C7) to Th10 (Th8 to Th11) vertebral interspace was achieved. Myocardial blood flow was measured with dynamic
13
N-ammonia PET with and without TEA at rest, during pharmacological vasodilation with dipyridamole, and during sympathetic stimulation with the cold pressor test. Myocardial blood flow during dipyridamole increased similarly, regardless of TEA, in all regions except in myocardium subtended by collateral arteries in which blood flow increased more with than without TEA (
P
<0.05). Without TEA, myocardial blood flow during the cold pressor test remained unchanged compared with myocardial blood flow at rest. In contrast, with TEA, myocardial blood flow increased in all vascular territories. Coronary vascular resistance increased during the cold pressor test without TEA, whereas with TEA, coronary resistance decreased in myocardium subtended by nonstenotic and stenotic coronary vessels and remained unchanged in myocardium subtended by occluded vessels.

Conclusions—

In patients with multivessel ischemic heart disease, TEA partly normalizes the myocardial blood flow response to sympathetic stimulation.
Endothelium-Intrinsic Requirement for
Hif-2
α During Vascular Development
Authors: Duan Li-Juan , Zhang-Benoit Yahui , Fong Guo-Hua
Published: April 2005

Background—

The development of the vascular system is a complex process that involves communications among multiple cell types. As such, it is important to understand whether a specific gene regulates vascular development directly from within the vascular system or indirectly from nonvascular cells. Hypoxia-inducible factor-2α (Hif-2α, or endothelial PAS protein-1 [EPAS-1]) is required for vascular development in mice, but it is not clear whether its requirement resides directly in endothelial cells.

Methods and Results—

To address this issue, we expressed
Hif-2
α cDNA in the vascular endothelium of
Hif-2
α
−/−
embryos by an embryonic stem (ES) cell–mediated transgenic approach and assessed whether endothelium-specific reexpression of
Hif-2
α could rescue vascular development. Here we report that although ES cell–derived
Hif-2
α
−/−
embryos developed severe vascular defects by embryonic day (E) 11.5 and died in utero before E12.5, endothelium-specific expression of
Hif-2
α cDNA restored normal vascular development at all stages examined (up to E14.5) and allowed
Hif-2
α
−/−
embryos to survive at a frequency comparable to that of
Hif-2
α
+/−
embryos. Furthermore, we found that
Tie-2
expression was significantly reduced in
Hif-2
α
−/−
mutants but was restored by
Hif-2
α cDNA expression.

Conclusions—

These data demonstrate an intrinsic requirement for Hif-2α by endothelial cells and imply that hypoxia may control endothelial functions directly via Hif-2α–regulated
Tie-2
expression.
Infarct-Sparing Effect of A
2A
-Adenosine Receptor Activation Is Due Primarily to Its Action on Lymphocytes
Authors: Yang Zequan , Day Yuan-Ji , Toufektsian Marie-Claire , Ramos Susan I. , Marshall Melissa , Wang Xin-Qun , French Brent A. , Linden Joel
Published: April 2005

Background—

A
2A
-adenosine receptor (A
2A
AR) activation on reperfusion after ischemia reduces the size of myocardial infarction, but the mechanism of action has not been fully defined.

Methods and Results—

We created chimeric mice by bone marrow transplantation from A
2A
AR-knockout or green fluorescent donor mice to irradiated congenic C57BL/6 (B6) recipients. In the GFP chimeras, we were unable to detect green fluorescent–producing cells in the vascular endothelium, indicating that bone marrow–derived cells were not recruited to endothelium at appreciable levels after bone marrow transplantation and/or acute myocardial infarction. Injection of 5 or 10 μg/kg of a potent and selective agonist of A
2A
AR, ATL146e, had no effect on hemodynamic parameters but reduced infarct size in B6 mice after 45 minutes of left anterior descending artery occlusion followed by 24 hours of reperfusion to 42.5±3.0% and 39.3±4.7% of risk region, respectively, compared with 61.0±2.3% in vehicle-treated B6 mice (
P
<0.05). Myocardial myeloperoxidase activity in the risk region measured at 4 hours after reperfusion was significantly reduced by ATL146e. The salutary effects of ATL146e were absent in A
2A
AR-knockout mice or in mice treated with a selective A
2A
AR antagonist, ZM241385. ATL146e also reduced infarct size and myeloperoxidase in B6/B6 (donor/recipient) chimeras (
P
<0.05) but not in A
2A
AR-knockout/B6 chimeras. In immunocompromised Rag-1–KO mice, infarct size was significantly reduced compared with B6 mice but was not further reduced by ATL146e.

Conclusions—

The results indicate that A
2A
AR activation on bone marrow–derived cells, specifically T or B lymphocytes, is responsible for the infarct-sparing and antiinflammatory effects of ATL146e administered at the time of reperfusion after coronary occlusion.
Regulation of Bone Morphogenetic Protein-2 Expression in Endothelial Cells
Authors: Csiszar Anna , Smith Kira E. , Koller Akos , Kaley Gabor , Edwards John G. , Ungvari Zoltan
Published: April 2005

Background—

Recent studies suggest that bone morphogenetic protein-2 (BMP-2), a transforming growth factor-β superfamily member cytokine, plays an important role both in vascular development and pathophysiological processes, including endothelial activation that is likely to contribute to the development of coronary atherosclerosis, yet the factors that regulate arterial expression of BMP-2 are completely unknown. We tested the hypothesis that BMP-2 expression in endothelial cells is governed by an H
2
O
2
and nuclear factor (NF)-κΒ–dependent pathway that can be activated by both proinflammatory and mechanical stimuli.

Methods and Results—

The proinflammatory cytokine tumor necrosis factor (TNF)-α induced NF-κΒ activation and elicited significant increases in BMP-2 mRNA and protein in primary coronary arterial endothelial cells and human umbilical vein endothelial cells that were prevented by NF-κΒ inhibitors (pyrrolidine dithiocarbamate and SN-50), silencing of p65 (siRNA), or catalase. Administration of H
2
O
2
also elicited NF-κΒ activation and BMP-2 induction. In organ culture, exposure of rat arteries to high pressure (160 mm Hg) elicited H
2
O
2
production, nuclear translocation of NF-κΒ, and upregulation of BMP-2 expression. Although high pressure upregulated TNF-α, it appears that it directly regulates BMP-2 expression, because upregulation of BMP-2 was also observed in vessels of TNF-α knockout mice.

Conclusions—

Vascular BMP-2 expression can be regulated by H
2
O
2
-mediated activation of NF-κΒ both by inflammatory stimuli and by high intravascular pressure.
Left Ventricular Systolic Performance, Function, and Contractility in Patients With Diastolic Heart Failure
Authors: Baicu Catalin F. , Zile Michael R. , Aurigemma Gerard P. , Gaasch William H.
Published: April 2005

Background—

Patients with diastolic heart failure (DHF) have significant abnormalities in left ventricular (LV) diastolic function, including slow and delayed relaxation and increased chamber stiffness. Whether and to what extent these abnormalities in diastolic function occur in association with abnormalities in LV systolic performance, function, and contractility has not been investigated thoroughly.

Methods and Results—

The systolic properties of the LV were examined in 75 patients with heart failure and a normal ejection fraction (ie, DHF) and 75 normal control subjects with no evidence of cardiovascular disease. LV systolic properties were assessed with echocardiographic and cardiac catheterization data. Stroke work (an index of LV systolic performance), preload recruitable stroke work and ejection fraction (indices of LV systolic function), systolic stress-shortening relationship, end-systolic pressure-volume relationship, and peak (+)dP/dt (indices of LV contractility) were examined. The systolic properties of the LV were normal in patients with DHF. Stroke work was 8.4±2.3 in DHF versus 8.8±2.5 kg · cm in controls (
P
=0.26). Preload recruitable stroke work was 99±22 in DHF versus 109±18 g/cm
2
in controls (
P
=0.13). The relationship between stroke work and end-diastolic volume was similar in DHF and controls. Peak (+) dP/dt was 1596±362 in DHF versus 1664±305 mm Hg/s in controls (
P
=0.54). The end-systolic pressure-volume relationship was increased in DHF. The systolic stress versus endocardial fractional shortening relationship was similar in DHF and controls.

Conclusions—

Patients with DHF had normal LV systolic performance, function, and contractility. The pathophysiology of DHF does not appear to be related to significant abnormalities in these systolic properties of the LV.
Cyclooxygenase-2 Inhibitors Attenuate Angiotensin II–Induced Oxidative Stress, Hypertension, and Cardiac Hypertrophy in Rats
Authors: Wu Rong , Laplante Marc-André , de Champlain Jacques
Published: April 2005

Angiotensin II is an important oxidative stress mediator. Our previous studies have indicated that the potent antioxidative properties of acetylsalicylic acid play an important role in its cardiovascular protective effects. There are some ongoing controversies concerning the use of selective cyclooxygenase-2 inhibitors in cardiovascular disease. The aim of this study was to determine whether the cyclooxygenase-2 selective inhibitors rofecoxib and nimesulide possess antioxidative and cardiovascular protective effects against angiotensin II. Chronic subcutaneous angiotensin II infusion increased cardiovascular but not colonic tissue superoxide production, heart/body weight ratio, and blood pressure. Moreover, angiotensin II selectively increased cardiac cyclooxygenase-2 but not cyclooxygenase-1 expression, which was totally prevented by acetylsalicylic acid treatment. Similar to acetylsalicylic acid, rofecoxib or nimesulide treatments significantly attenuated angiotensin II–induced oxidative stress, hypertension, and cardiac NAD(P)H oxidase subunit p47
phox
expression. Rofecoxib also reduced cardiac hypertrophy. Treatment with nonselective anti-inflammatory drugs ibuprofen, indomethacin, or salicylic acid did not show any effect on angiotensin II–induced superoxide production, hypertension, or cardiac hypertrophy. Although acetylsalicylic acid and salicylic acid inhibited angiotensin II–induced nuclear factor κB (NF-κB) activation, nimesulide did not modify NF-κB activation. In conclusion, cyclooxygenase-2 pathway is implicated in angiotensin II–induced oxidative stress and deleterious cardiovascular changes. Rofecoxib and nimesulide produced significant antioxidative effect by reducing NAD(P)H oxidase–dependent superoxide generation. These effects seem to be independent of NF-κB inhibition.
Advanced Glycation End Products Are Associated With Pulse Pressure in Type 1 Diabetes
Authors: Schram Miranda T. , Schalkwijk Casper G. , Bootsma Aart H. , Fuller John H. , Chaturvedi Nish , Stehouwer Coen D.A.
Published: April 2005

We investigated the associations of pulse pressure (a measure of arterial stiffness) with the early glycation products hemoglobin A1c (HbA1c) and Amadori albumin and the advanced glycation end products pentosidine,
N
ε
-(carboxymethyl)lysine and
N
ε
-(carboxyethyl)lysine in a large group of type 1 diabetic individuals of the EURODIAB Prospective Complications Study. We did a cross-sectional nested case-control study from the EURODIAB Prospective Complications Study of 543 (278 men) European individuals with type 1 diabetes diagnosed at <36 years of age. We used linear regression analyses to investigate the association of pulse pressure with glycation products. Pulse pressure was significantly associated with plasma levels of
N
ε
-(carboxymethyl)lysine and
N
ε
-(carboxyethyl)lysine but not with HbA1c, Amadori albumin, and urinary levels of pentosidine. Regression coefficients adjusted for age, sex, mean arterial pressure, and duration of diabetes were 0.09 mm Hg (
P
=0.003) per 1 μM/M lysine
N
ε
-(carboxymethyl)lysine; 0.24 mm Hg (
P
=0.001) and −0.03 mm Hg (
P
=0.62) per 1 μM/M lysine
N
ε
-(carboxyethyl)lysine (in individuals with and without complications, respectively;
P
interaction=0.002); and 0.50 mm Hg (
P
=0.16) per 1% HbA1c; 0.07 mm Hg (
P
=0.12) per 1 U/mL Amadori albumin; and 0.77 mm Hg (
P
=0.48) per 1 nmol/mmol creatinine pentosidine. In young type 1 diabetic individuals, arterial stiffness is strongly associated with the advanced glycation end products
N
ε
-(carboxymethyl)lysine and
N
ε
-(carboxyethyl)lysine. These findings suggest that the formation of advanced glycation end products is an important pathway in the development of arterial stiffness in young type 1 diabetic individuals.
Progression of Coronary Artery Calcium and Occurrence of Myocardial Infarction in Patients With and Without Diabetes Mellitus
Authors: Raggi Paolo , Cooil Bruce , Ratti Carlo , Callister Tracy Q. , Budoff Matthew
Published: April 2005

Progression of coronary artery calcium, a marker of atherosclerosis, can be slowed with statins, and continued progression of calcium is associated with an increased risk of myocardial infarction. However, it is not known whether statins are effective in slowing calcium progression in diabetes mellitus. In a retrospective study, we examined 1153 nondiabetic and 157 diabetic subjects who underwent sequential electron beam tomography scans at a minimum 1-year interval to assess progression of coronary calcium. A yearly score increase >15% was considered evidence of true progression. The use of statins and occurrence of myocardial infarction were recorded. There was no difference in baseline calcium score between diabetic and nondiabetic patients. Diabetic patients with no coronary calcium on the baseline scans developed it more often than nondiabetic subjects (42% versus 25%;
P
=0.046) during follow-up. Calcium progression was 33% greater in diabetic patients than nondiabetic subjects (
P
<0.001) if no statin therapy was provided and 17.7% greater when statins were used (
P
<0.001). Among the 49 subjects who experienced a myocardial infarction, the calcium score increased on average 20% more in diabetic than nondiabetic patients (
P
<0.001). In logistic models, diabetes mellitus and systemic hypertension were the best predictors of calcium progression (odds ratio, 3.1 and 1.9, respectively), whereas baseline calcium score percentile and statin therapy were the best predictors of infarction. These findings support the notion that diabetes mellitus causes accelerated atherosclerosis, even in the presence of statin therapy, and provide evidence that coronary calcium monitoring is an effective method to assess treatment efficacy.
Structural and Genetic Bases of Arterial Stiffness
Authors: Laurent Stéphane , Boutouyrie Pierre , Lacolley Patrick
Published: April 2005

Arterial stiffness has independent predictive value for cardiovascular events. We review data concerning the heritability of arterial stiffness, and propose an integrated view of the structural and genetic determinants of arterial stiffness, based on a candidate gene approach and recent studies on gene expression profile. Arterial stiffness seems to have a genetic component, which is largely independent of the influence of blood pressure and other cardiovascular risk factors. In animal models of essential hypertension (SHR and SHR-SP), structural modifications of the arterial wall include an increase in the number of elastin/smooth muscle cell (SMC) connections, and smaller fenestrations of the internal elastic lamina, possibly leading to redistribution of the mechanical load toward elastic materials. These modifications may give rise to mechanisms that explain why changes in arterial wall material accompanying wall hypertrophy in these animals are not associated with an increase in arterial stiffness. In monogenic connective tissue diseases (Marfan, Williams, and Ehlers-Danlos syndromes) and the corresponding animal models, precise characterization of the arterial phenotype makes it possible to determine the influence of abnormal genetically determined wall components on arterial stiffness. Such studies have highlighted the role of extracellular matrix signaling in the vascular wall and have shown that elastin and collagen not only display elasticity or rigidity but also are involved in the control of SMC function. These data provide strong evidence that arterial stiffness is affected by the amount and density of stiff wall material and the spatial organization of that material.
Stereoscopic Synergy: Twin-Relief Sculpture and Painting
Authors: Biegon Glenn
Published: April 2005

Two accelerated-relief sculp-tures depicting the same scene from slightly different viewpoints can serve as sculpted stereo-scopic half-images—or “twin-reliefs.” Unlike traditional relief sculpture, which compresses sculptural space, twin-reliefs expand it, creating lifelike illusionistic depths. Viewed binocularly in a large Wheat-stone stereoscope, the twin-relief's virtual world appears colorful, atmospheric and life-size— even infinitely deep. Furthermore, unlike flat-picture stereoscopy, which allows just one undistorted, perspectively robust view, twin-reliefs provide infinitely many such views because, being sculptural, they “adapt” to the observer's movement. Twin-reliefs syner-gistically combine essential physical attributes previously separated between the domains of painting, sculpture and traditional flat-picture stereoscopy.
Theory of the Snowflake Plot and Its Relations to Higher-Order Analysis Methods
Authors: Czanner Gabriela , Grün Sonja , Iyengar Satish
Published: April 2005

The snowflake plot is a scatter plot that displays relative timings of three neurons. It has had rather limited use since its introduction by Perkel, Gerstein, Smith, and Tatton (1975), in part because its triangular coordinates are unfamiliar and its theoretical properties are not well studied. In this letter, we study certain quantitative properties of this plot: we use projections to relate the snowflake plot to the cross-correlation histogram and the spike-triggered joint histogram, study the sampling properties of the plot for the null case of independent spike trains, study a simulation of a coincidence detector, and describe the extension of this plot to more than three neurons.
Observations of Quasi-Stationary and Shallow Orographic Snow Clouds: Spatial Distributions of Supercooled Liquid Water and Snow Particles
Authors: Kusunoki Kenichi , Murakami Masataka , Orikasa Narihiro , Hoshimoto Mizuho , Tanaka Yoshinobu , Yamada Yoshinori , Mizuno Hakaru , Hamazu Kyosuke , Watanabe Hideyuki
Published: April 2005

On 25 February 1999, due to a winter monsoon after a cyclonic storm, orographic snow clouds formed under conditions of weak cold advection on the western side of the central mountain range of Japan. In this study, the Ka-band Doppler radar and vehicle-mounted microwave radiometer and 2D-Grey imaging probe were used to obtain unique datasets for analyzing the spatial distributions of microphysical structures of the snow clouds at the windward slope. The liquid water path, number concentration of snow particles (0.1–6.4 mm diameter), and precipitation rate were found to be correlated with altitude. The greater concentration of larger particles tended to appear up the slope. The echo top was at about 2.5 km (−30 dBZ), and the relatively strong echo region (>−3 dBZ) appeared at 5 km up the slope and extended nearly parallel to the slope. According to the echo pattern, the ice water path increased with terrain height and reached the maximum intensity at about 14 km up the slope. These observations provide indirect evidence that terrain-induced updrafts lead to the generation and growth of supercooled cloud droplets and indicate that the riming process plays an important role in the growth of snow particles at higher altitudes. In this paper, it is confirmed that the abundance of supercooled liquid water (SLW) during intensified monsoon flow is due to larger water production rates caused by higher vertical velocities induced by topography. Furthermore, it can be shown that small-scale terrains enhance localized updrafts embedded within the larger-scale flow and have noticeable impact on SLW cloud distribution.
CIRA/CSU Four-Dimensional Variational Data Assimilation System
Authors: Zupanski Milija , Zupanski Dusanka , Vukicevic Tomislava , Eis Kenneth , Haar Thomas Vonder
Published: April 2005

A new four-dimensional variational data assimilation (4DVAR) system is developed at the Cooperative Institute for Research in the Atmosphere (CIRA)/Colorado State University (CSU). The system is also called the Regional Atmospheric Modeling Data Assimilation System (RAMDAS). In its present form, the 4DVAR system is employing the CSU/Regional Atmospheric Modeling System (RAMS) nonhydrostatic primitive equation model. The Weather Research and Forecasting (WRF) observation operator is used to access the observations, adopted from the WRF three-dimensional variational data assimilation (3DVAR) algorithm. In addition to the initial conditions adjustment, the RAMDAS includes the adjustment of model error (bias) and lateral boundary conditions through an augmented control variable definition. Also, the control variable is defined in terms of the velocity potential and streamfunction instead of the horizontal winds. The RAMDAS is developed after the National Centers for Environmental Prediction (NCEP) Eta 4DVAR system, however with added improvements addressing its use in a research environment.

Preliminary results with RAMDAS are presented, focusing on the minimization performance and the impact of vertical correlations in error covariance modeling. A three-dimensional formulation of the background error correlation is introduced and evaluated. The Hessian preconditioning is revisited, and an alternate algebraic formulation is presented. The results indicate a robust minimization performance.
Diurnal Circulation of the Bolivian Altiplano. Part I: Observations
Authors: Egger Joseph , Blacutt Luis , Ghezzi Flavio , Heinrich Richard , Kolb Philip , Lämmlein Stephan , Leeb Martin , Mayer Stephanie , Palenque Eduardo , Reuder Joachim , Schäper Wolfgang , Schween Jan , Torrez Rene , Zaratti Francesco
Published: April 2005

In July and August 2003 a field campaign was conducted to explore the diurnal circulation of the Bolivian Altiplano. Vertical soundings by remote-controlled aircraft yielded profiles of temperature, pressure, and humidity at six passes and in a valley. Pilot balloon observations provided wind profiles. Two permanent stations collected additional data. Typically, inflow toward the Altiplano commences a few hours after sunrise at about the time when the stable nocturnal layer near the ground is transformed by the solar heating into an almost neutrally stratified convective boundary layer. The depth of the inflow layer is comparable to but normally less than that of this boundary layer. There are indications of return flow aloft. The inflow continues at least until sunset. Moisture is imported at the passes leading to the Yungas in the east. Strong upvalley flows were found in the valley of the Rio de La Paz, which connects the wide canyon of La Paz with the tropical lowlands to the east. Inflow was absent at one of the passes despite favorable synoptic conditions. Cases of synoptically forced flows are presented as well where the diurnal signal is difficult to separate. A simple flow scheme is presented that fits the observations reasonably well.
Dropsonde Observations in Low-Level Jets over the Northeastern Pacific Ocean from CALJET-1998 and PACJET-2001: Mean Vertical-Profile and Atmospheric-River Characteristics
Authors: Ralph F. Martin , Neiman Paul J. , Rotunno Richard
Published: April 2005

Dropsonde observations are used to document the mean vertical profiles of kinematic and thermodynamic conditions in the pre-cold-frontal low-level-jet (LLJ) region of extratropical cyclones over the eastern Pacific Ocean. This is the region within storms that is responsible not only for the majority of heavy rainfall induced by orography when such storms strike the coast, but also for almost all meridional water vapor transport at midlatitudes. The data were collected from NOAA’s P-3 aircraft in 10 storms during the California Land-falling Jets Experiment (CALJET) of 1998 and in 7 storms during the Pacific Land-falling Jets Experiment (PACJET) of 2001. The mean position of the dropsondes was 500 km offshore, well upstream of orographic influences. The availability of data from two winters that were characterized by very different synoptic regimes and by differing phases of ENSO—that is, El Niño in 1998 and La Niña in 2001—allowed examination of interannual variability.

The composite pre-cold-frontal profiles reveal a well-defined LLJ at 1.0-km altitude with a wind speed of 23.4 m s−1 and a wind direction of 216.7°, as well as vertical shear characteristic of warm advection. The composite thermodynamic conditions were also documented, with special attention given to moist static stability due to the nearly saturated conditions that were prevalent. Although the dry static stability indicated very stable conditions (4.5 K km−1), the moist static stability was approximately zero up to 2.8-km altitude. Although the composite winds, temperatures, and water vapor mixing ratios in 2001 differed markedly from 1998, the moist static stability remained near zero from the surface up to 2.8–3.0-km altitude for both seasons. Hence, orographic precipitation enhancement is favored in this sector of the storm, regardless of the phase of ENSO.

The dropsonde data were also used to characterize the depth and strength of atmospheric rivers, which are responsible for most of the meridional water vapor transport at midlatitudes. The vertically integrated along-river water vapor fluxes averaged 525 × 105 kg s−1 (assuming a 100-km-wide swath), while the meridional and zonal components were 387 × 105 kg s−1 and 302 × 105 kg s−1, respectively. Although the composite meridional transport in 2001 was less than half that in 1998 (230 × 105 kg s−1 versus 497 × 105 kg s−1), the characteristic scale height of the meridional water vapor transport remained constant; that is, 75% of the transport occurred below 2.25-km altitude.
Outcome After Tracheostomy for Respiratory Failure in the Elderly
Authors: Engoren Milo C. , Arslanian-Engoren Cynthia M.
Published: April 2005

The purpose of this study was to determine hospital and postdischarge survival and functional status at follow-up in elderly patients receiving tracheostomy for respiratory failure and to determine if these outcomes differed between the younger elderly (65-74 years) and the older elderly (= 75 years). This was a retrospective chart review with prospective administration of the SF-36 conducted in 228 patients aged 65 years or older who had undergone tracheostomy to facilitate mechanical ventilation for respiratory failure at a tertiary care, university-affiliated, urban medical center. Demographics, comorbidities, hospital survival, liberation from mechanical ventilation, long-term survival, and functional status were determined. Combined hospital and hospice mortality did not differ by age, being 34% and 26% in the 65- to 74-year and = 75-year groups, respectively ( P> .05). However, older patients (= 75 years old) were more likely to be discharged still requiring mechanical ventilation (62% vs 45%, P< .05). Only one half of hospital survivors survived for 1 additional year. Those discharged ventilator-dependent were more likely to die. Of the 20 participants in the SF-36 portion of the study, most had fair to good emotional and social functioning but were extremely limited physically.
Lung Injury and Bronchopulmonary Dysplasia in Newborn Infants
Authors: Christou Helen , Brodsky Dara
Published: April 2005

Bronchopulmonary dysplasia is the most common morbidity among surviving premature infants. Injury to the developing lung is the result of the interaction between a susceptible host and a number of contributing factors such as mechanical ventilation and infection. The resulting persistent impairment of pulmonary function and need for ongoing therapy are the underlying characteristics of bronchopulmonary dysplasia. Important insights into the pathogenesis of bronchopulmonary dysplasia have led to numerous therapies and preventive approaches. Although significant progress has been made, in order to further affect the incidence and severity of the disease, we need to further study (a) the genetically determined predisposing factors, (b) the relative contribution of the various pathogenetic pathways, and, most important, (c) how to best translate the knowledge gained from these studies into effective clinical approaches.
Propofol Use Precludes Prescription of Estimated Nitrogen Requirements
Authors: Taylor Stephen J. , Bowles Jon , Jewkes Claire
Published: April 2005

The objective was to determine whether reducing enteral nutrition to accommodate 1% Propofol-derived energy results in suboptimal nitrogen prescription. This was a prospective observational study of 85 consecutive patients requiring mechanical ventilation and receiving 1% Propofol. Enteral nutrition prescription often failed to meet nitrogen requirements (<90%, in 50.6%; <80%, in 21.1%), whereas fat provided 51% of total energy input, exceeding 2 g fat/kg/d in 20%. However, gastroparesis was common, resulting in suboptimal nutrition (median of requirements: energy 71%; nitrogen 57%). If energy balance had been strictly maintained, substituting 1% with 2% Propofol would reduce the number of patients failing to meet nitrogen requirements (1% vs 2%: <90%: in 58.8% vs 17.6%, P< .001; <80% in 35.3% vs 4.7%, P< .014). These effects are directly related to the amount of fat delivered with Propofol. Intensive care unit–associated gastroparesis commonly reduces enteral nutrition input. However, even where this is overcome, use of 1% Propofol frequently precludes prescription of estimated nitrogen requirements; either 2% Propofol or a non-Propofol alternative should be considered.
Radiocontrast-Induced Acute Renal Failure
Authors: Weisbord Steven D. , Palevsky Paul M.
Published: April 2005

The intravascular administration of iodinated radiocontrast media can lead to acute renal dysfunction. Even small changes in renal function have been associated with increased morbidity and mortality, making the prevention of radiocontrast nephropathy of paramount importance. This review summarizes the principal risk factors for radiocontrast nephropathy and evidence-based preventive strategies that should be used to limit its occurrence. Risk factors for radiocontrast nephropathy include preexistent kidney disease, diabetes mellitus, dose of radiocontrast used, advanced congestive heart failure, and intravascular volume depletion. Proven preventive measures include volume expansion with intravenous saline or sodium bicarbonate and the use of low-osmolar or iso-osmolar radiocontrast media. Studies evaluating N-acetylcysteine have been conflicting, with meta-analyses suggesting a small beneficial effect. Studies of other pharmacologic agents have not demonstrated clinical benefit.
Trends in Complete Blood Count Values During Acute Painful Episodes in Children With Sickle Cell Disease
Authors: Jacob Eufemia , Miaskowski Christine , Savedra Marilyn , Beyer Judith E. , Treadwell Marsha , Styles Lori
Published: April 2005

Complete blood count (CBC) values are monitored as crude indicators of the hemolytic and inflammatory processes that accompany an acute painful episode in children with sickle cell disease. As part of a larger study that examined the pain experience and pain management of hospitalized children during painful vaso-occlusive episodes, the authors examined trends in CBC values and determined whether there were relationships between these values and pain intensity scores. Children, 5 to 19 years of age, with sickle cell disease whose primary reason for admission was vasoocclusive pain were recruited for participation in the study. Once every evening from the day of admission until the day of discharge, they were asked to rate their worst and least pain using the numeric rating scale of the African American Oucher pain scale. Complete blood count values were obtained from the hospital information system on a daily basis. Parallel changes in CBC values and pain intensity scores were evident within the first 48 hours of hospitalization. However, although the inflammatory and hemolytic processes were resolving, pain persisted at moderate levels throughout the course of hospitalization.
Factor V Leiden and Its Effect on Children With Cardiac Pathology
Authors: Connor Jean A.
Published: April 2005

Factor V Leiden thrombophilia, formed by a genetic mutation, slows the body’s anticoagulation response to clot formation. First described in 1994, factor V Leiden mutation has been identified as a contributing risk factor for venous thromboembolism. Although venous thromboembolism is considered rare in the pediatric population, Factor V Leiden has implications for certain at-risk pediatric patients.
Neurocognitive Sequelae of Sickle Cell Disease: Current Issues and Future Directions
Authors: Routhieaux Julie , Sarcone Susan , Stegenga Kristin
Published: April 2005

Sickle cell disease is a genetic disorder with an autosomal recessive pattern of inheritance. This disease is most prevalent among those of African American and Mediterranean descent. Cerebral vascular accident (CVA) or stroke is one of the major complications of hemoglobin SS (Hgb SS) disease. CVA has implications for physical as well as neurocognitive function for children. Recent literature suggests that some children with sickle cell disease without overt signs of CVA may still have evidence of neurological deficit, both on magnetic resonance imaging and neurological examination. There is a growing body of knowledge that further aids in delineation of risk factors for CVA, silent infarct, and neurocognitive deficits in children with Hgb SS disease. More research is needed to continue to explore avenues for identification and intervention. The purpose of this article is to delineate areas of ongoing research in this important area.
Neonatal Hematologic Disorders
Authors: Purves Erica
Published: April 2005

Neonatal hematology is a complex subspecialty of pediatric hematology, combining the unique aspects of the maternal/fetal relationship, the delicate balance of coagulation factors, and the distinctive physiologic conditions of the newborn period. The objective of this article is to briefly review specific hematologic disorders that commonly present in the newborn period. Alloimmune cytopenias, polycythemia, thrombosis and bleeding associated with vitamin K deficiency will be discussed through a focus on pathophysiology, signs and symptoms, current treatment strategies, and implications for nursing care.
Inherited Coagulation Factor Abnormalities: A Pediatric Review
Authors: Sevier Nicole
Published: April 2005

Clotting factor abnormalities in children provide an interesting challenge to the medical care team. Understanding the diagnostic process and the medical management of children with factor abnormalities is crucial, as life-threatening complications can occur. This article will familiarize the reader with symptoms, laboratory testing, diagnosis, and treatment of hereditary coagulation factor abnormalities.
Using Community-Based Participatory Research Methods to Reach Women With Health Messages: Results From the North Carolina BEAUTY and Health Pilot Project
Authors: Linnan Laura A. , Ferguson Yvonne Owens , Wasilewski Yvonne , Lee Ann Marie , Yang Jingzhen , Solomon Felicia , Katz Mira
Published: April 2005

This pilot study used a community-based participatory research approach to recruit and train five licensed cosmetologists from two beauty salons to deliver health promotion messages to their customers. Stylists attended a 4-hr workshop to develop skills for delivering targeted health messages. Educational displays in the salons reinforced these messages. Qualitative and quantitative methods assessed satisfaction, readiness to change, and self-reported health behavior changes in customers immediately postintervention and at 12 months. Trained stylists reported they would continue delivering health messages after the 7-week pilot was completed; 81% of customers read the educational displays, and 86% of customers talked with their cosmetologist about the Bringing Education and Understanding to You Project. At 12 months, 55% of customers reported making changes in their health because of the conversations they had with their cosmetologist. Customers who spoke more often with their cosmetologists about health also reported a higher percentage of self-reported behavior changes. It appears that trained licensed cosmetologists are effective in promoting health messages to their customers.
Under the Influence: Taking Alcohol Issues Into the College Classroom
Authors: Riley Joan Burggraf , Durbin Patrick T. , D'Ariano Mary
Published: April 2005

Alcohol use and abuse among college students pose an enormous and unique public health problem that is associated with significant harm to students. Colleges nationwide are seeking to address student alcohol use through a variety of programs and policies. An effort at Georgetown University in Washington, D.C., combines a campus-wide dialogue on the subject with the infusion of alcohol issues into the curriculum of an undergraduate course in the School of Nursing and Health Studies. Course evaluations indicate that participants benefited from the curriculum infusion approach. Participants became aware of the health education resources available to students and the campus culture contributing to alcohol. In addition, student participants evaluated their own alcohol use, with significant modifications of alcohol consumption behaviors.
Implementation of a Family Intervention to Increase Fruit and Vegetable Intake: The Hi5+ Experience
Authors: Harrington Kathleen F. , Franklin Frank A. , Davies Susan L. , Shewchuk Richard M. , Binns Maria Brown
Published: April 2005

Family is an important, yet challenging, target for dietary intervention. This article describes the implementation of Hi5+, a family fruit and vegetable (FV) promotion program. Complementing a fourth-grade school curriculum, the seven weekly Family Fun Nites were at-home family meal sharing and game evenings. A sample of families (N = 575; 69% consented) from schools in a southeastern U.S. urban area received tailored intervention materials based on their FV attitudes and family interaction styles. A pyramidal organizational design, using peer leaders, facilitated 71% of families to complete all seven sessions, whereas 84% completed at least one session. Significant independent predictors of program completion were attending an introductory Kick-Off Nite, interactive family style, additional adults in the household, married parents, being African American, earning more than $60,000, and additional children in the household. Familyspecific issues and initial program experience are important considerations for implementing a family intervention.
Mind the Gap! Insight From the First 5 Years of the Circle of Research and Practice
Authors: Roe Kathleen M. , Lancaster Brick
Published: April 2005

This article provides a summary of insight, thoughts, discussions, diversity, and lessons learned in the first 5 years of invited commentaries in this health promotion practice department, the Circle of Research and Practice. The summary is framed in the four persistent gaps that need attention if the circle of research and practice is to be unbroken: communication, accessibility, credibility, and expectations.
Redefinition of Affymetrix probe sets by sequence overlap with cDNA microarray probes reduces cross-platform inconsistencies in cancer-associated gene expression measurements
Authors: Carter Scott L , Eklund Aron C , Mecham Brigham H , Kohane Isaac S , Szallasi Zoltan
Published: April 2005

Background

Comparison of data produced on different microarray platforms often shows surprising discordance. It is not clear whether this discrepancy is caused by noisy data or by improper probe matching between platforms. We investigated whether the significant level of inconsistency between results produced by alternative gene expression microarray platforms could be reduced by stringent sequence matching of microarray probes. We mapped the short oligo probes of the Affymetrix platform onto cDNA clones of the Stanford microarray platform. Affymetrix probes were reassigned to redefined probe sets if they mapped to the same cDNA clone sequence, regardless of the original manufacturer-defined grouping. The NCI-60 gene expression profiles produced by Affymetrix HuFL platform were recalculated using these redefined probe sets and compared to previously published cDNA measurements of the same panel of RNA samples.

Results

The redefined probe sets displayed a substantially higher level of cross-platform consistency at the level of gene correlation, cell line correlation and unsupervised hierarchical clustering. The same strategy allowed an almost complete correspondence of breast cancer subtype classification between Affymetrix gene chip and cDNA microarray derived gene expression data, and gave an increased level of similarity between normal lung derived gene expression profiles using the two technologies. In total, two Affymetrix gene-chip platforms were remapped to three cDNA platforms in the various cross-platform analyses, resulting in improved concordance in each case.

Conclusion

We have shown that probes which target overlapping transcript sequence regions on cDNA microarrays and Affymetrix gene-chips exhibit a greater level of concordance than the corresponding Unigene or sequence matched features. This method will be useful for the integrated analysis of gene expression data generated by multiple disparate measurement platforms.
GABAAreceptor γ2 subunit knockdown mice have enhanced anxiety-like behavior but unaltered hypnotic response to benzodiazepines
Authors: Chandra Dev , Korpi Esa R , Miralles Celia P , De Blas Angel L , Homanics Gregg E
Published: April 2005

Background

Gamma-aminobutyric acid type A receptors (GABAA-Rs) are the major inhibitory receptors in the mammalian brain and are modulated by a number of sedative/hypnotic drugs including benzodiazepines and anesthetics. The significance of specific GABAA-Rs subunits with respect to behavior and in vivo drug responses is incompletely understood. The γ2 subunit is highly expressed throughout the brain. Global γ2 knockout mice are insensitive to the hypnotic effects of diazepam and die perinatally. Heterozygous γ2 global knockout mice are viable and have increased anxiety-like behaviors. To further investigate the role of the γ2 subunit in behavior and whole animal drug action, we used gene targeting to create a novel mouse line with attenuated γ2 expression, i.e., γ2 knockdown mice.

Results

Knockdown mice were created by inserting a neomycin resistance cassette into intron 8 of the γ2 gene. Knockdown mice, on average, showed a 65% reduction of γ2 subunit mRNA compared to controls; however γ2 gene expression was highly variable in these mice, ranging from 10–95% of normal. Immunohistochemical studies demonstrated that γ2 protein levels were also variably reduced. Pharmacological studies using autoradiography on frozen brain sections demonstrated that binding of the benzodiazepine site ligand Ro15-4513 was decreased in mutant mice compared to controls. Behaviorally, knockdown mice displayed enhanced anxiety-like behaviors on the elevated plus maze and forced novelty exploration tests. Surprisingly, mutant mice had an unaltered response to hypnotic doses of the benzodiazepine site ligands diazepam, midazolam and zolpidem as well as ethanol and pentobarbital. Lastly, we demonstrated that the γ2 knockdown mouse line can be used to create γ2 global knockout mice by crossing to a general deleter cre-expressing mouse line.

Conclusion

We conclude that: 1) insertion of a neomycin resistance gene into intron 8 of the γ2 gene variably reduced the amount of γ2, and that 2) attenuated expression of γ2 increased anxiety-like behaviors but did not lead to differences in the hypnotic response to benzodiazepine site ligands. This suggests that reduced synaptic inhibition can lead to a phenotype of increased anxiety-like behavior. In contrast, normal drug effects can be maintained despite a dramatic reduction in GABAA-R targets.