bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Intestinal Calcium Transport
Authors: Khanal Ramesh C. , Nemere Ilka
Published: July 2008

Calcium is an essential ion in all organisms and participates in a variety of structural and functional roles. Calcium (re)absorption occurs in epithelia, including the intestine, kidney, mammary glands, placenta, and gills of fish. Its transport is regulated by a complex array of processes that are mediated by hormonal, developmental, and physiological factors involving the gastrointestinal tract, bone, kidney, and the parathyroids. Here we review the calcium transport mechanisms—paracellular, which is energy independent, and transcellular, which is energy dependent—primarily focusing on the intestine. We provide a new perspective on the facilitated diffusion and vesicular transport models to account for the emerging concepts on transcellular calcium transport. Finally, we discuss how 1,25(OH)2D3 and parathyroid hormone regulate calcium transport.
Where Does Fetal and Embryonic Cholesterol Originate and What Does It Do?
Authors: Woollett Laura A.
Published: July 2008

The development of a single-celled fertilized egg, through the blastocyst stage of a ball of cells and the embryonic stage when almost all organ systems begin to develop, and finally to the fetal stage where growth and physiological maturation occurs, is a complex and multifaceted process. A change in metabolism during gestation, especially when organogenesis occurs, can lead to abnormal development and congenital defects. Although many studies have described the roles of specific proteins in development, the roles of specific lipids, such as sterols, have not been studied as intensely. Sterol's functions in development range from being a structural component of membranes to regulating the patterning of the forebrain through sonic hedgehog to regulating expression of key proteins involved in metabolic processes. This review focuses on the roles of sterols in embryonic and fetal development and metabolism. Potential sources of cholesterol for the fetus and embryo are also discussed.
Translating Nutrition Science into Policy as Witness and Actor
Authors: Rosenberg Irwin H.
Published: July 2008

The sustained effort to witness and participate in the targeted translation of nutritional science and policy forms the structure of this narrative. The memoir starts with an early career-directing experience with nutrition and cholera and proceeds with a long thread of interest in folic acid malabsorption as one of the determinants of nutritional anemia in Asia and the tropics. The thread continues with the relationship of folate and associated vitamins to brain function and aging as a prototype of the study of the interface of aging biology and nutritional biology. My current interest in world hunger and famine and their impact on human security may circle back to studies of the great Bengal famine and the first Bangladesh survey of malnutrition.
Cell Volume and Sodium Content in Rat Kidney Collecting Duct Principal Cells During Hypotonic Shock
Authors: Solenov Evgeny I.
Published: July 2008

The purpose of this study was to investigate the time course of the volume-regulatory response and intracellular sodium concentration([Na+]i)in the principal cells of rat kidney outer medulla collecting duct (OMCD) epithelia during acute swelling in hypotonic medium. Hypotonic shock was created by PBS diluted with 50% of water. Changes in cell volume were measured with calcein quenching method. Intracellular sodium concentration was studied with fluorescence dye Sodium Green. Principal cells of microdissected OMCD fragments swelled very fast. The characteristic time of swelling (τ1) was0.65±0.05 seconds, and the volume increased more than 60% (92.9±5.6and151.3±9.8 μm3control and peak volumes correspondently,P<.01). After cell volume reached the peak of swelling, the RVD began without lag period. The characteristic time of volume decreasing to new steady-state level (τ2) was8.9±1.1 seconds. In hypoosmotic medium, cell volume stabilized on higher level in comparison with control (110.3±8.3 μm3,P<.01). After restoration of the medium osmolality to normotonic, cell volume stabilized on significantly low level in comparison with control level (71.4±6.1 μm3,P<.01). During the hypoosmotic shock,[Na+]idecreased from control level in isotonic PBS to the low level in hypoosmotic solution (27.7±1.4and5.8±0.23 mM,P<.01). Calculation of sodium content per cell has shown the significant sodium entry into the cells, which caused a temporary increase correlated with the peak of cell volume caused by swelling. The conclusion is made that in our model of hypoosmotic shock, swelling activates transporters with high permeability forNa+that provides sodium flux into the cells.
Templated Fabrication of InSb Nanowires for Nanoelectronics
Authors: Khan M. Ibrahim , Wang Xu , Bozhilov Krassimir N. , Ozkan Cengiz S.
Published: July 2008

Among various ways
to produce nanowires, anodic alumina membrane‐
(AAM‐) based synthesis has constantly received
much attention, because AAM has a uniform and parallel porous nanostructure which makes it an ideal template material for fabricating highly ordered nanostructures. In this paper, we report
fabrication of InSb nanowire arrays with
diameter of 200 nm and 30 nm by
direct current electrodeposition inside the
nanochannels of anodic alumina membranes without
subsequent annealing. The nanowires have four
major growth directions, (220) being the most
dominant with structure defects such as twins.
The transmission electron microscopy (TEM) and
scanning electron microscopy (SEM) results
demonstrate that these InSb nanowires are
uniform with diameters about 200 nm and
30 nm, corresponding to the pore diameter
of the AAMs. The I‐V measurement of a single
nanowire is also reported with encouraging
preliminary results.
Can You Hear the Femur Play? Bone Audio Speakers at the Nanoscale
Authors: Chapple Boo , Wong William
Published: July 2008

This paper describes the research process involved in making audio speakers out of cow bone. The paper begins by discussing the conceptual basis of the work. It goes on to explain the piezoelectric nature of the bone matrix and how this makes it possible for bone to operate as an audio speaker. It then chronicles the process of working from a theoretical possibility to a functional speaker. In the concluding section of the paper, the final artifacts and conceptual outcomes of the process are discussed.
The Response of the ITCZ to Extratropical Thermal Forcing: Idealized Slab-Ocean Experiments with a GCM
Authors: Kang Sarah M. , Held Isaac M. , Frierson Dargan M. W. , Zhao Ming
Published: July 2008

Using a comprehensive atmospheric GCM coupled to a slab mixed layer ocean, experiments are performed to study the mechanism by which displacements of the intertropical convergence zone (ITCZ) are forced from the extratropics. The northern extratropics are cooled and the southern extratropics are warmed by an imposed cross-equatorial flux beneath the mixed layer, forcing a southward shift in the ITCZ. The ITCZ displacement can be understood in terms of the degree of compensation between the imposed oceanic flux and the resulting response in the atmospheric energy transport in the tropics. The magnitude of the ITCZ displacement is very sensitive to a parameter in the convection scheme that limits the entrainment into convective plumes. The change in the convection scheme affects the extratropical–tropical interactions in the model primarily by modifying the cloud response. The results raise the possibility that the response of tropical precipitation to extratropical thermal forcing, important for a variety of problems in climate dynamics (such as the response of the tropics to the Northern Hemisphere ice sheets during glacial maxima or to variations in the Atlantic meridional overturning circulation), may be strongly dependent on cloud feedback. The model configuration described here is suggested as a useful benchmark helping to quantify extratropical–tropical interactions in atmospheric models.
Improving Ocean Model Initialization for Coupled Tropical Cyclone Forecast Models Using GODAE Nowcasts
Authors: Halliwell G. R. , Shay L. K. , Jacob S. D. , Smedstad O. M. , Uhlhorn E. W.
Published: July 2008

To simulate tropical cyclone (TC) intensification, coupled ocean–atmosphere prediction models must realistically reproduce the magnitude and pattern of storm-forced sea surface temperature (SST) cooling. The potential for the ocean to support intensification depends on the thermal energy available to the storm, which in turn depends on both the temperature and thickness of the upper-ocean warm layer. The ocean heat content (OHC) is used as an index of this potential. Large differences in available thermal energy associated with energetic boundary currents and ocean eddies require their accurate initialization in ocean models. Two generations of the experimental U.S. Navy ocean nowcast–forecast system based on the Hybrid Coordinate Ocean Model (HYCOM) are evaluated for this purpose in the NW Caribbean Sea and Gulf of Mexico prior to Hurricanes Isidore and Lili (2002), Ivan (2004), and Katrina (2005). Evaluations are conducted by comparison to in situ measurements, the navy’s three-dimensional Modular Ocean Data Assimilation System (MODAS) temperature and salinity analyses, microwave satellite SST, and fields of OHC and 26°C isotherm depth derived from satellite altimetry. Both nowcast–forecast systems represent the position of important oceanographic features with reasonable accuracy. Initial fields provided by the first-generation product had a large upper-ocean cold bias because the nowcast was initialized from a biased older-model run. SST response in a free-running Isidore simulation is improved by using initial and boundary fields with reduced cold bias generated from a HYCOM nowcast that relaxed model fields to MODAS analyses. A new climatological initialization procedure used for the second-generation nowcast system tended to reduce the cold bias, but the nowcast still could not adequately reproduce anomalously warm conditions present before all storms within the first few months following nowcast initialization. The initial cold biases in both nowcast products tended to decrease with time. A realistic free-running HYCOM simulation of the ocean response to Ivan illustrates the critical importance of correctly initializing both warm-core rings and cold-core eddies to correctly simulate the magnitude and pattern of SST cooling.
An Efficient and Accurate Method for Computing the Wet-Bulb Temperature along Pseudoadiabats
Authors: Davies-Jones Robert
Published: July 2008

A new technique for computing the wet-bulb potential temperature of a parcel and its temperature after pseudoadiabatic ascent or descent to a new pressure level is presented. It is based on inverting Bolton’s most accurate formula for equivalent potential temperature θE to obtain the adiabatic wet-bulb temperature Tw on a given pseudoadiabat at a given pressure by an iterative technique. It is found that Tw is a linear function of equivalent temperature raised to the −1/κd (i.e., −3.504) power, where κd is the Poisson constant for dry air, in a significant region of a thermodynamic diagram. Consequently, Bolton’s formula is raised to the −1/κd power prior to the solving. A good “initial-guess” formula for Tw is devised. In the pressure range 100 ≤ p ≤ 1050 mb, this guess is within 0.34 K of the converged solution for wet-bulb potential temperatures θw ≤ 40°C. Just one iteration reduces this relative error to less than 0.002 K for −20° ≤ θw ≤ 40°C. The upper bound on the overall error in the computed Tw after one iteration is 0.2 K owing to an inherent uncertainty in Bolton’s formula. With a few changes, the method also works for finding the temperature on water- or ice-saturation reversible adiabats.

The new technique is far more accurate and efficient than the Wobus method, which, although little known, is widely used in a software package. It is shown that, although the Wobus function, on which the Wobus method is based, is supposedly only a function of temperature, it has in fact a slight pressure dependence, which results in errors of up to 1.2 K in the temperature of a lifted parcel. This intrinsic inaccuracy makes the Wobus method far inferior to a new algorithm presented herein.
Weighted Position and Motion Vector Consensus of Tropical Cyclone Track Prediction in the Western North Pacific
Authors: Elsberry Russell L. , Hughes James R. , Boothe Mark A.
Published: July 2008

Two approaches are developed and tested to improve the unweighted position consensus for 96-, 108-, and 120-h tropical cyclone track guidance in the western North Pacific. A weighted position guidance technique uses a weighting factor for each model that is inversely proportional to how far the 60-, 66-, and 72-h positions of that model are from the corresponding positions of the 11-member position consensus. The weighted position consensus of 96-, 108-, and 120-h track errors for a sample of 24 storms during the 2006 season are consistently smaller than for the unweighted position consensus.

In the second approach, a weighted motion vector consensus is developed that uses the same weighting factors as in the weighted position consensus, except that the weights are applied to 12-h motion vectors between 84 and 120 h. This weighted motion vector consensus has substantially smaller errors than the unweighted position consensus, and results in smoother tracks when one or more of the model tracks drops out of the consensus. It is proposed that the weighted motion vector consensus would provide improved guidance for the 96-, 108-, and 120-h tropical cyclone track forecasts.
Sensitivity of the PBL and Precipitation in 12-Day Simulations of Warm-Season Convection Using Different Land Surface Models and Soil Wetness Conditions
Authors: Trier S. B. , Chen F. , Manning K. W. , LeMone M. A. , Davis C. A.
Published: July 2008

A coupled land surface–atmospheric model that permits grid-resolved deep convection is used to examine linkages between land surface conditions, the planetary boundary layer (PBL), and precipitation during a 12-day warm-season period over the central United States. The period of study (9–21 June 2002) coincided with an extensive dry soil moisture anomaly over the western United States and adjacent high plains and wetter-than-normal soil conditions over parts of the Midwest. A range of possible atmospheric responses to soil wetness is diagnosed from a set of simulations that use land surface models (LSMs) of varying sophistication and initial land surface conditions of varying resolution and specificity to the period of study.

Results suggest that the choice of LSM [Noah or the less sophisticated simple slab soil model (SLAB)] significantly influences the diurnal cycle of near-surface potential temperature and water vapor mixing ratio. The initial soil wetness also has a major impact on these thermodynamic variables, particularly during and immediately following the most intense phase of daytime surface heating. The soil wetness influences the daytime PBL evolution through both local and upstream surface evaporation and sensible heat fluxes, and through differences in the mesoscale vertical circulation that develops in response to horizontal gradients of the latter. Resulting differences in late afternoon PBL moist static energy and stability near the PBL top are associated with differences in subsequent late afternoon and evening precipitation in locations where the initial soil wetness differs among simulations. In contrast to the initial soil wetness, soil moisture evolution has negligible effects on the mean regional-scale thermodynamic conditions and precipitation during the 12-day period.
Stepwise Onset of Monsoon Weather Observed in the Nepal Himalaya
Authors: Ueno K. , Toyotsu K. , Bertolani L. , Tartari G.
Published: July 2008

Mountain weather changes in the Nepal Himalaya were intensively examined during the 2003 monsoon onset using in situ datasets, observed by multiple automatic weather stations (AWS) distributed across the Coordinated Enhanced Observing Period (CEOP) Himalaya reference site at locations with significant differences in altitude. Onset of monsoon rainfall characterized as nighttime precipitation was initiated simultaneously at all stations with the occurrence and migration of a monsoon depression in the north of the Bay of Bengal. Satellite infrared images detected evident suppression of diurnal cloud development after the onset. About two weeks prior to the onset, the mountain weather abruptly changed such that the daytime valley wind at lower elevations weakened associated with morning clouds and the nighttime southerly wind began at upper elevations. The timing corresponded with the weakening of the westerly wind over the Himalaya due to the northward shift of the upper subtropical jet stream. The time lag between the precipitation onset and the change in the mountain weather was confirmed by 9 yr of in situ AWS data. The mechanism of nighttime southerly winds at high elevations is also discussed in relation to large-scale monsoon flow and local circulation.
Probabilistic Forecast Calibration Using ECMWF and GFS Ensemble Reforecasts. Part II: Precipitation
Authors: Hamill Thomas M. , Hagedorn Renate , Whitaker Jeffrey S.
Published: July 2008

As a companion to Part I, which discussed the calibration of probabilistic 2-m temperature forecasts using large training datasets, Part II discusses the calibration of probabilistic forecasts of 12-hourly precipitation amounts. Again, large ensemble reforecast datasets from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Global Forecast System (GFS) were used for testing and calibration. North American Regional Reanalysis (NARR) 12-hourly precipitation analysis data were used for verification and training. Logistic regression was used to perform the calibration, with power-transformed ensemble means and spreads as predictors. Forecasts were produced and validated for every NARR grid point in the conterminous United States (CONUS). Training sample sizes were increased by including data from 10 nearby grid points with similar analyzed climatologies. “Raw” probabilistic forecasts from each system were considered, in which probabilities were set according to ensemble relative frequency. Calibrated forecasts were also considered based on three amounts of training data: the last 30 days of forecasts (available for 2005 only), weekly reforecasts during 1982–2001, and daily reforecasts during 1979–2003 (GFS only).

Several main results were found. (i) Raw probabilistic forecasts from the ensemble prediction systems’ relative frequency possessed little or negative skill when skill was computed with a version of the Brier skill score (BSS) that does not award skill solely on the basis of differences in climatological probabilities among samples. ECMWF raw forecasts had larger skills than GFS raw forecasts. (ii) After calibration with weekly reforecasts, ECMWF forecasts were much improved in reliability and were moderately skillful. Similarly, GFS-calibrated forecasts were much more reliable, albeit somewhat less skillful. Nonetheless, GFS-calibrated forecasts were much more skillful than ECMWF raw forecasts. (iii) The last 30 days of training data produced calibrated forecasts of light-precipitation events that were nearly as skillful as those with weekly reforecast data. However, for higher precipitation thresholds, calibrated forecasts using the weekly reforecast datasets were much more skillful, indicating the importance of large sample size for the calibration of unusual and rare events. (iv) Training with daily GFS reforecast data provided calibrated forecasts with a skill only slightly improved relative to that from the weekly data.
Edema and Leg Volume: Methods of Assessment
Authors: Guex J.J. , Perrin Michel
Published: July 2008

Various techniques may be used to assess leg edema. The value of these investigations has been discussed in depth in the consensus statement made in Vaux de Cernay in 1997 and supported by Servier Research Group.

These techniques can be classified into three groups:

• The most simple is leg circumference measurement, which can be assessed by a tape measure, or more rigorously with a Leg-O-Meter. This device is a cheap and repro ducible method that has been validated and that takes into account the height at which the circumference has been measured. However, circumference measurement is not always correlated with leg (including foot) volume measurement.

• The second group of techniques assess leg volume. The most simple method is water displacement volumetry, which has been validated in terms of reproducibility. Several other devices have been used: optoelectronic methods, computed tomography, magnetic resonance imaging (high resolution), dual X-ray absorptiometry. These methods are expensive and not all of them have been validated, but these might be the future investigations of choice. (continued on next page)

• Some other investigations assess immediate variations in volume such as water displacement using dynamic foot volumetry, rheoplethysmography, strain gauge plethysmography, and air plethysmography. The assessment made by these methods (using postural, dynamic, or compressive maneuvers) is more an assessment of the venomuscular pump and/or venous outflow than volume assessment.

In conclusion, edema, an early and frequent sign of chronic venous insufficiency (CVI), can be precisely measured by several methods. This measurement can be considered one of the most objective ways of assessing treatment efficacy in CVI-associated edema.
Management of Venous Edema: Insights from an International Task Force
Authors: Clement D.L.
Published: July 2008

An International Task Force made up of a panel of 16 experts has reviewed and objec tively evaluated all aspects of chronic venous disease of the leg (CVDL). All available publications on CVDL from 1983 to 1997 were identified through computerized search in Medline and by a manual search. Next, three different screenings were performed in order to select only relevant papers providing a level of scientific evidence that was considered moderate to strong. Final conclusions and further therapeutic recommenda tions were made based on these publications. Medication, compression, local therapy, sclerotherapy, and surgery are the accepted available therapeutic options for CVDL. For edema, the following recommendations can be made: edema is an early sign of CVDL, but before starting any treatment, nonvenous causes of edema should be excluded. Medication and compression are the therapeutic options for edema that are accepted by the Task Force. Evaluation of their efficacy is based on objective measures of edema. Several well-conducted, placebo-controlled trials have shown efficacy of drugs such as micronized purified flavonoid fraction, rutosides, calcium dobesilate, and coumarin rutin. Graduated compression stockings have been shown to be effective; compression needs to be exerted at least at 35 mm Hg. Bandages, if properly applied, both fixed and stretched, can produce favorable results. Sclerotherapy or surgery is not indicated unless there is saphenofemoral or saphenopopliteal reflux. In the absence of such reflux or following deep venous thrombosis, there is no evidence to support scle rotherapy or surgery.
Pharmacologic Aspects of a Phlebotropic Drug in CVI-Associated Edema
Authors: Ramelet Albert-Adrien
Published: July 2008

Several phlebotropic drugs, or edema-protecting drugs, are available, the most important of which are found in the γ-benzopyrone family (flavonoids). γ-Benzopyrones can be plant extracts, semisynthetic preparations, or synthetic preparations. This family is divided into two different groups: flavones and flavonols, and flavanes (flavanones). The flavone group contains various types of molecule and includes diosmin. Here we discuss the pharmacologic aspects in edema associated with chronic venous insufficiency (CVI) of one of the reference phlebotropic drugs, micronized purified flavonoid fraction (MPFF*), a semisynthetic preparation from the diosmin group, which represents the latest improvement in flavonoid formulation. Before we detail the pharmacologic aspects, a brief summary of the pathophysiology of edema in CVI is necessary. Several factors are implicated: the veins, which create the conditions favorable to edema; the microcir culation, which is the site of fluid transfer into the interstitial tissue; and the lymphatics, which have a limited possibility to reduce edema. Major discoveries are currently being made in CVI and the microcirculation. Results of studies show that MPFF decreases capillary permeability and increases capillary resistance, which could partly be explained by inhibition of leukocyte activation, migration, and adhesion. This inhibition is linked to a significant decrease in plasma levels of endothelial adhesion molecules (VCAM-1 and ICAM-1) after MPFF treatment. Thus, the CVI-induced damage to the microcirculation is counteracted by MPFF. The lymphatic system is also improved by MPFF treatment. The lymphagogue activity of MPFF has been demonstrated in experimental animal models and confirmed by microlymphographic measurement in patients suffering from severe CVI. The pharmacologic activity of MPFF in lymphedema was observed in a study using an animal model of acute lymphedema and in a study in patients with upper limb lymphedema secondary to breast cancer treatment. All these findings point to the impor tance of acting on each factor involved in the formation and maintenance of edema. This pharmacologic activity is indeed reflected by the clinical efficacy on edema observed during treatment with MPFF.
RELIEF Study: First Consolidated European Data
Authors: Jantet Georges
Published: July 2008

The RELIEF study (Reflux assEssment and quaLity of lIfe improvement with micronized Flavonoids in chronic venous insufficiency [CVI]) is a prospective, controlled, multi center, international study performed in patients with or without venous reflux. This study was conducted between March 1997 and December 1998 in 23 countries worldwide with the participation of more than 10,000 patients suffering from CVI. The European countries, the subject of this report, were represented by the Czech and Slovak Republics, Hungary, Poland, Russia, and Spain.

The principal aims of the study were:

1. To validate the first quality-of-life scale specific to chronic venous insufficiency (CIVIQ) in different languages and to assess the evolution of quality of life in patients suffering from CVI, with or without venous reflux, treated with micronized purified flavonoid fraction (MPFF*) (1,000 mg/day)

2. To collect international epidemiologic data on venous reflux assessed with pocket Doppler and photoplethysmography

3. To assess the evolution of symptoms and signs with a specific emphasis on edema through validated Leg-O-Meter measurement (heaviness, pain, cramps, sensation of swelling, edema) in patients suffering from CVI and treated with MPFF, 1,000 mg/day, during 6 months.

The first country-by-country statistical analysis and the European consolidated analysis are now available. The CIVIQ questionnaires adapted to each participating country have been validated with highly significant validity and reproducibility (p < 0.0001). All dimen sions have demonstrated a highly significant and evolving improvement during the study.

The results show several interesting findings concerning the epidemiologic data and, of these, two were particularly interesting:

• More than 50% of patients suffering from CVI (class 0 to 4 of the CEAP classification) were reflux-free, which means that they were suffering from functional CVI.

• Patient distribution between the different classes of the CEAP classification changed in a statistically significant manner after 6 months' treatment with MPFF; the number of patients in the more severe classes decreased to the benefit of the less severe classes.

Symptoms such as pain, leg heaviness, sensation of swelling, and cramps were signifi cantly improved (p=0.0001). This was associated with a significant decrease in edema, when present, measured by leg circumferences with the Leg-O-Meter (p=0.0001).

In conclusion, the European results of the RELIEF study showed the perfect validity and reproducibility of CIVIQ questionnaire adaptations, and the positive progression of quality-of-life scores on MPFF treatment. This progression was paralleled by clinical improvement of patients reflected not only by assessment of CVI symptoms and signs but also by evolution of the CEAP classification.
The Relative Influence of Lesion Length and Other Stenosis Morphologies on Procedural Success of Coronary Intervention
Authors: Iliadis Elias A. , Zaacks Stephen M. , Calvin James E. , Allen Jill , Parrillo Joseph E. , Klein Lloyd W.
Published: July 2008

As coronary interventional technology improves, the influence of lesion length (LL) on procedural success and device selection may vary. Thus, the authors prospectively analyzed 957 consecutive coronary interventions (CI) in 1,404 stenoses to ascertain the influence of lesion length on CI outcome. Stenosis morphology was prospectively classi fied by the AHA/ACC criteria. LL was analyzed both as dichotomous (S: < 10 mm, L: > 10 mm) variables and by the three-tiered AHA/ACC criteria (I: < 10 mm, II: 10-20 mm, III: > 20 mm). There was a significant univariate relationship between CI success and S stenosis (S: 95.8% vs L: 91.8%, p = 0.002 and I: 96.0%, II: 91.7%, III: 89.3%). Numerous interrelationships involving the morphologic characteristics were noted: lesion morphologies associated with S lesions were concentric (p = 0.0001) and had smooth contour (p = 0.0001), ostial location (p = 0.05) and little calcification (p = 0.0007), while irregular contour (p = 0.0001), calcification (p = 0.0076), eccentric (p = 0.0001), thrombus (p = 0.0001), recent (p = 0.0001) or chronic (p = 0.001) total occlusion were associated with L lesions. When these relationships were taken into account by multiple logistic regression analysis, lesion length was not predictive of procedural outcome (p = 0.099). One morphologic type was associated with increased CI success: irregular contour (p = 0.022); recent (p < 0.0001) or chronic (< 0.0001) occlusions were associ- ated with decreased CI success. Another factor considered was device selection: S lesions were associated with greater balloon angioplasty usage (p = 0.002), whereas more coronary stents (p = 0.024) and rotoblator (p = 0.018) devices were used in L lesions. More balloon angioplasty was performed in concentric (p < 0.0001) lesions; interven tional devices were employed more often in eccentric (p < 0.0001) and irregular lesions (p < 0.0001). More complications were noted in lesions with thrombus (p = 0.0002), but lesion length was not predictive (p = NS). Lesion length is not a significant predictor of procedural success when adjusted for other lesion morphologies in the modern inter ventional era. The availability of new devices has improved the results in longer lesions since the AHA/ACC criteria were originally proposed.
Successful Percutaneous Balloon Mitral Valvuloplasty Using Left Ventricular Pressure as a Guide to Cross the Mitral Valve
Authors: Kwan Tak , Clark Luther T. , Safi Arshad M.
Published: July 2008

Percutaneous balloon mitral valvuloplasty (PBMV) provides an effective alternative to surgery in a selective group of patients with symptomatic mitral stenosis. The Inoue balloon technique involves transseptal catheterization followed by catheter manipulation to cross the mitral valve. The authors describe a case of successful percutaneous balloon mitral valvuloplasty in a patient with severe mitral stenosis and pulmonary hyperten sion. Left ventricular systolic pressure was used as a guide to locate and to advance the balloon catheter across the mitral valve. This technique to cross the mitral valve has not been reported in the literature.
Ventricular Ectopic Activity, Left Ventricular Mass, Hyperinsulinemia, and Intracellular Magnesium in Normotensive Patients with Obesity
Authors: Žemva Žarka , Žemva Aleš
Published: July 2008

Insulin resistance, a well-known feature of obesity, is associated with several pathological changes, which are potentially arrhythmogenic. Ventricular ectopic activity in normoten sive obese patients has not been studied in detail. Therefore the authors designed a study to investigate potential relationships among ventricular ectopic activity, left ventricular mass, hyperinsulinemia, and intracellular magnesium concentration in obese patients. Thirty-two obese patients and 32 nonobese control subjects, who were referred to outpa tient department because of ventricular ectopy, participated in the study. The groups were matched for age and gender. All had normal glucose tolerance. All subjects underwent a 75-g glucose tolerance test, and blood samples were obtained at 30, 60, and 120 minutes thereafter for determination of glucose and insulin concentrations. Echocardiography was performed and left ventricular mass index was calculated. The number of ventricular ectopic beats per hour (VEB/hour) was recorded by 24-hour ECG Holter monitoring. Plasma and erythrocyte magnesium concentrations were determined by atomic absorption spectrophotometer. Obese patients had higher body weight, body mass index, heart rate, and left ventricular mass index. Obese subjects had higher fasting insulin as well as insulin/glucose ratio and broader area under the curve of insulin (AUC-I) compared to nonobese subjects. Insulin sensitivity appeared to be lower in the obese group. Holter monitoring showed more VEB/hour in the obese group. Magnesium concentration in serum and in erythrocytes was lower in obese persons. In the obese group a positive correlation was found between left ventricular mass index and fasting insulin ( r=0.345, p=0.027), insulin/glucose index ( r=0.351, p=0.049), and AUC-I ( r=0.405, p=0.011). The number of VEB/hour in obese patients was in positive corre lation with age ( r=0.681, p<0.001), left ventricular mass index ( r=0.542, p=0.001), fasting insulin ( r=0.380, p=0.016), and AUC-I ( r=0.493, p=0.002) and in negative correlation with magnesium concentration in erythrocytes ( r=-0.457, p=0.004). Multiple regression analysis showed that age and AUC-I are the only determinants of VEB/hour and together explained 56% of the variability in the obese subjects. It appears that in obese normotensive subjects, ventricular ectopic beats are related to age, insulin resistance, left ventricular mass index, and decreased intracellular magnesium content.
Influence of the Ultrasound Contrast Agent Levovist® on Human Nailfold Capillary Microcirculation
Authors: Immer Franz F. , Seiler Andrea M. , Aeschbacher Beat C. , Mahler Felix , Saner Hugo , Saner H.
Published: July 2008

Little is known about the behavior of ultrasound contrast microbubbles in human capil laries. The evaluation of circulatory effects of echo contrast media may bring valuable information for the interpretation of echo contrast phenomena in the human myocardium. In 12 healthy volunteers (aged 31 ±6.7 years; five women), nailfold capil laries were examined by means of TV microscopy. The authors investigated acral micro circulation at rest and after local cold application with and without saccharide-based microbubbles (10 mL Levovist® 300 mg/mL IV). The mean blood flow velocity at rest was 1.18 ±0.18 mm/s (mean value ±1 SD) and 1.11 ±0.11 mm/s (mean value ±1 SD) after the injection of Levovist® (ns). One minute after local cold exposure a decrease of the blood flow velocity by 61% before and by 75% after intravenous Levovist® was found. In both groups the cold-induced decrease of blood flow velocity was statistically significant (p<0.01), whereas there was no significant difference in flow reaction between the two groups. No wall adhesion of blood cells or extravasation of contrast into the surrounding tissue was detected. After intravenous injection of a regular dose of saccharide-based microbubbles Levovist®, no change of blood cell flow velocity and no wall adhesion or extravasation could be found at rest and after cold application in human nailfold capil laries. Since microcirculatory flow characteristics in the finger nailfold capillaries are not influenced by Levovist®, it might be assumed also that myocardial blood flow behavior remains unchanged, so that this contrast agent may be used as a flow tracer for cardiac investigation.
Incomplete Caval Protection Following Suprarenal Caval Filter Placement
Authors: Lemmon Gary W. , Litscher Lawrence J. , Lemmon Gary W.
Published: July 2008

Inferior vena cava filters are increasingly utilized to prevent pulmonary emboli origi nating from lower extremity, pelvis, or caval thromboses. Unique indications exist for filter placement in the suprarenal portion of the vena cava. The largest reported experi ence in suprarenal position has involved the use of the Greenfield filter. Although unique in design, little differences have been described between the stainless steel and titanium version of this device. The authors present a case report of incomplete caval protection after successful placement of a stainless steel Greenfield filter in the suprarenal cava. Subtle differences between the titanium and the stainless steel Greenfield filter may exist and should be taken into consideration for placement in the suprarenal cava. Physiologic conditions supporting this premise are described. Further investigation between the two filter types appears justified.
Deep Venous Thrombosis and Pulmonary Thromboembolism Associated with a Huge Uterine Myoma
Authors: Nishikawa Hiroaki , Ideishi Munehito , Nishimura Taku , Kawamura Akira , Kamochi Hideyuki , Tahara Hisafumi , Tsuchiya Yoshihiro , Shirai Kazuyuki , Okabe Masanori , Arakawa Kikuo , Ideishi Munehito
Published: July 2008

A 51-year-old woman with a large uterine myoma suffered from acute pulmonary throm boembolism. Venography revealed thrombosis in the right common iliac vein and almost complete obstruction of the left common iliac vein. The ascending lumbar vein showed collateral drainage. Treatment was initiated with continuous intravenous heparin sodium, and a Greenfield filter was inserted to prevent the extension of the pulmonary embolism during and after hysterectomy. After a total hysterectomy, venography revealed restora tion of patency in the bilateral common iliac veins, and no flow was seen in the ascending lumbar vein. Thorough clinical examinations failed to identify any other prothrombotic conditions. These results suggest that a large uterine myoma compressed veins in the pelvis, and the resulting impaired blood flow caused deep venous thrombosis and pulmonary thromboembolism.
Relationship Between Physical Activity Recall and Free-Living Daily Physical Activity in Older Claudicants
Authors: Otis Rosemary B. , Brown Allison S. , Womack Christopher J. , Fonong Tekum , Gardner Andrew W. , Gardner Andrew W.
Published: July 2008

The purposes of this study were to determine the relationship between the physical activity values obtained from the peripheral arterial disease-physical activity recall (PAD-PAR) questionnaire and (1) the free-living daily physical activity obtained from the doubly labeled water technique and (2) clinical measures of PAD severity. Fifty-one older PAD patients (age=70 ±6 years) were recruited from the Vascular Clinic at the Baltimore Veterans Affairs Medical Center and from radio and newspaper advertisements. Energy expenditure of physical activity (EEPA) was determined by using doubly labeled water and indirect calorimetry techniques. PAD severity was measured by ankle/brachial index (ABI) and walking distance to maximal claudication pain determined during a graded treadmill test. In addition, patients were also characterized on body composition and total daily energy expenditure. The physical activity values obtained from the PAD-PAR questionnaire (113 ±37 MET-hr/wk) were not related to EEPA (542 ±260 kcal/day; r= -0.057, p=0.690), ABI (0.64 ±0.19; r=0.032, p=0.826), or distance to maximal clau dication pain (376 ±229 m; r=-0.054, p=0.731). The authors conclude that the PAD-PAR questionnaire is not an accurate measurement of free-living daily physical activity when compared to EEPA by use of the criterion method of doubly labeled water, and the activity questionnaire measures were poorly correlated with clinical measures of PAD severity.
Brachial Artery Blood Flow Velocity Pattern in Patients with Congestive Heart Failure: Duplex Doppler Ultrasonographic Assessment
Authors: Güler Niyazi , Bilge Mehmet , Eryonucu Beyhan , Erkoç Reha , Ipeksoy Ümit , Güler Niyazi
Published: July 2008

The purpose of this study was to determine whether there are abnormalities in blood flow velocity pattern of the brachial artery in patients with congestive heart failure (CHF). Brachial artery blood flow velocities were measured with duplex Doppler ultrasonog raphy in 12 normal subjects, 31 patients with congestive heart failure (CHF), and 26 patients with coronary artery disease (CAD). None of the patients had clinical evidence of arterial disorders at upper extremities. In both patient groups, the presence of hyper tension was correlated with the peak systolic velocity (r=0.48, p<0.05). Patients with heart failure had significantly larger (p<0.0001) peak reverse velocity (20 ± 6 m/sec) than healthy subjects (5 ±4 m/sec) and patients with CAD (7 ±3 m/sec). Peak reverse velocity did not differ significantly between normal subjects and CAD group. These data indicate that the blood flow velocity pattern at brachial artery is abnormal in CHF. The simple measurement of brachial artery flow velocity suggests changes in peripheral vascu lature related to CHF.
Deep Venous Thrombosis Associated with Acute Brucellosis
Authors: Odeh Majed , Pick Neora , Oliven Arie , Odeh Majed
Published: July 2008

Vascular complications, including arteries and veins associated with Brucella infection, have rarely been reported. To date, only three cases of deep venous thrombosis (DVT) of the lower extremities associated with brucellosis have been previously reported. The authors describe another case of DVT of the right leg in association with acute Brucella infection. Since infection with Brucella may be asymptomatic, and the manifestations of acute brucellosis are exceedingly nonspecific, and in view of the potential for Brucella to cause unexplained or unusual illness involving almost any organ including blood vessels, the authors' case and those previously reported suggest that brucellosis should be included among the causes and infections taken into account in patients suffering from DVT, particularly in those coming from Brucella-endemic areas.
Assessment of Collateral Perfusion: A Pharmacodynamic Study with Bulflomedil Hydrochloride
Authors: Eichlisberger Remy , Jeanneret Christina , Frauchiger Beat , Aschwanden Markus , Jäger Kurt A. , Labs Karl-Heinz
Published: July 2008

The aim of the study was to assess the influence of Buflomedil hydrochloride on collat eral function. Ten patients with isolated superficial femoral occlusions were investigated twice by duplex sonography with measurement sites at the common femoral artery (CF) and the popliteal artery (PA). After the second scan 200 mg of Buflomedil hydrochloride were infused; the infusion was followed by a third duplex examination. Endpoints assessed included the arterial diameter (DCF, DPA), the systolic peak velocity (Vmax), the mean velocity of the maximum envelope (Vmean m.e.), the intensity weighted time average mean velocity (Vmean i.w.), the maximum reverse flow velocity (Vrev), the end- diastolic velocity (Venddiast), the calculated volume flow (Q), the pulsatility and the resistance indices (PI, RI), and PI and RI based segmental damping factors (DFPI, DFRI). For the CF measurement site the infusion of Buflomedil hydrochloride resulted in a signif icant reduction in Vrev and PI (p < 0.05), whereas trends in the opposite direction (increase) were observed for both measures of Vmean and for Q (0.1<p<0.05). No significant changes were reported for the PA measurement site. DFPI numerically decrcased (0.1 <p<0.05). The pattern of changes suggest that Buflomedil hydrochloride induces collateral vasodilation and thus improves collateral function.
Combined Genetic Defect (Homogeneity for Factor V Leiden and Heterogeneity for Prothrombin G20210A Allele), in a Young Patient, with Recurrent Deep Vein Thrombosis and Serious Postphlebitic Syndrome
Authors: Ioannou Hristos , Eleftheriou Athanasios , Nousias Vasilios , Basioukas Constantinos , Kakosimos George , Batsis Charalabos , Vartholomatos George , Mitsis M.
Published: July 2008

Just a few years ago, resistance to activated protein C (APCR) was reported to be of high significance representing a strong predisposing factor in the development of venous thrombosis (VT). A little while later, APCR was established to be the result of a point mutation of the factor V gene (factor V Leiden: a G-to-A transition at position 1691). Up to today, it is not certain whether factor V Leiden is in itself able to lead to VT, or whether it acts in synergy with other factors. Nevertheless, heterozygous subjects have a tenfold increase in the risk of VT when compared to general population, whereas the risk is 80 times greater in homozygous individuals. In 1996, a prothrombin gene mutation (prothrombin G20210A allele), which is a single-nucleotide G-to-A transition at position 20210 in the sequence of the 3'-untranslated region (3'UTR) on chromosome 11, was discovered. The presence of this mutant gene results in elevated plasma prothrombin concentrations, increasing the possibility for the development of VT. However, the coex- istence of these two abnormalities, as well as the clinical consequence, have not yet been studied. So far, only a few reports are found in the literature describing the coexistence of both mutations. The authors present a 25-year-old patient with a simultaneous double mutation of the FV and F II gene. The patient was homozygous for the factor V Leiden and heterozygous for the prothrombin G20210A allele. It is unclear whether the coexis tence of the two predisposes more to the development of VT than the summation of the two as independent factors.
Ischemic Preconditioning: The Endogenous Power
Authors: Alsaddique Ahmed A.
Published: July 2008

With the re-emergence of surgery on a beating heart, it is important to examine the unique phenomenon of ischemic preconditioning (IPC) and its role as a form of myocardial protec tion under these circumstances. Ischemic preconditioning is defined as a short period of ischemia, regional or global, imposed before a more prolonged period of ischemia, which increases the myocardium's tolerance to ischemia by endogenous adaptive mechanism. 1 Until recently, it was generally held that repeated ischemic episodes would have a cumu lative adverse effect and could lead to a "stuttering infarction."