bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Consequences of Low‐Quality Schooling under Asymmetric Information
Authors: Pigliaru Francesco , Vannini Marco
Published: June 2007

ABSTRACT: The substantial failure of many public programmes intended to increase job opportunities of youth via better education and training has been ascribed mainly to quantitative factors like mismatching or insufficient funds This paper takes a different perspective and concentrates on qualitative aspects It proposes a simple analytical scheme designed to study the consequences of low quality education on the performance of the policy created educational organisations under asymmetric information The model considers two types of schools (high quality H and low quality B) and asks whether there is any room left for the low quality one It is found that an adverse selection process may start within the pool of applicants to school B even under very favourable demand conditions and that any worsening of these conditions lowers the equilibrium average quality of type B graduates Eventually the market for type B certificates may disappear
New Tasks for a Theory of the Labor Movement: New Beginnings in Eastern Europe
Authors: Scoville James G.
Published: June 2007

ABSTRACT:This paper briefly reviews the thinking about labor movements which grew out of the ideological conflicts stemming from the Cold War. The framework proposed by Adolf Sturmthal and James Scoville is contrasted with other recent views, especially in terms of applicability to the labor movement in post‐Communist Europe. Some empirical work is brought to bear on the subject.
Modelling Incomplete Spells of Unemployment and Employment
Authors: Lalla Michele
Published: June 2007

ABSTRACT:The procedure used to analyse a data set which includes only censored or incomplete spells is examined in this paper. First of all, the distributions of incomplete spell durations are analysed without explanatory variables (such as age, gender, and so on), assuming that unobserved completed spells have a Weibull distribution. The relationships between the mean of the incomplete spells and the mean of the completed spells are reported for first‐job seekers, unemployed, employed and self‐employed workers. Given that the unobserved completed spells are Weibull‐distributed, the unobserved heterogeneity is introduced on the scale parameter of the Weibull. The heterogeneity, considered as a variable, is analysed for a binomial or Weibull distribution. As the beginning of a spell is a retrospective datum, the recall errors are modelled including the heaping effect. Using some proportional hazards models, the methodology to study the influences of explanatory variables on spell distributions is then described, once again including both the heterogeneity and the heaping effect. On this basis, the lengths of on‐going spells of unemployment for first‐job seekers and unemployed workers are modelled, as well as the current job tenures of employed and self‐employed workers.
The Older Worker in the Low Countries
Authors: Simoens Peter , Denys Jan , Omey Eddy
Published: June 2007

Abstract. The paper deals with present, demographically‐based problems in highly‐developed labour markets, with special reference to the Belgian and Dutch experience. Both sluggish inflow by young cohorts and early retirement by senior workers are analysed. The first of these phenomena can be explained by the falling birth rate and increasing educational levels; the second phenomenon is the result of technological changes in the labour market and a social security system which offers attractive opportunities for early outflow. For companies, this trend translates into a loss of experience and a loss of corporate culture. On top of this, the social security system is coming under heavy pressure and scarcity symptoms are likely to develop on the supply side of the labour market.
An Integrated Model of Cumulative Growth: Empirical Evidence for Nine OECD Countries, 1960‐1990
Authors: Pini Paolo
Published: June 2007

ABSTRACT: This paper is an empirical analysis of the interaction between the dynamics of demand, productivity and employment in nine industrial countries: the United States, Canada, Japan, West Germany, France, Italy, the United Kingdom, the Netherlands and Belgium, 1960‐1990. Its theoretical framework derives from the Kaldorian approach to cumulative growth in both its external and internal causation versions. The model we adopt is of an integrated kind, in which foreign demand is determined endogenously and domestic demand is divided into various component parts: exogenous for the public sector and endogenous for the private. More specifically, this is carried out by describing the way the dynamics of private consumption and private investments depend on economic variables located in the spheres of distribution and of technology, so that we can consider the operations of income compensation effects induced by technological change — via changes in income and its social distribution — as well as price compensation effects— the higher competitiveness of national products in foreign markets — mediated through the dynamics of exports.
Mergers and Bargaining in the Airline Industry
Authors: Crémieux Pierre‐Yves , Van Audenrode Marc
Published: June 2007

ABSTRACT: Using newly collected firm‐level data, this paper analyzes the effect of mergers on the earnings and employment of pilots, flight attendants, and mechanics in the US airline industry between 1971 and 1990. The results show that mergers had a significant and largely negative impact on flight attendants’earnings but have a limited impact on mechanics’and none on pilots’earnings. Mergers have no significant direct impact on employment for pilots or mechanics but affected flight attendants’employment negatively. The indirect impact of reduced activity following mergers did lead to an overall negative impact on employment for pilots and significantly increased the magnitude of the effect for flight attendants.
Evaluating Effects of Training within a Company: Methods, Problems and One Application
Authors: Gelderblom Arie , de Koning Jaap
Published: June 2007

ABSTRACT: In the Netherlands, interest in the measurement of the effects of training has increased. In most cases this measurement has been done by drawing conclusions on analyses with samples of firms. However, individual companies will be more interested in the effects of training within their own organisation. In this paper we discuss possible methods of measuring the effects of training within an organisation. A crucial element of such an analysis is the use of performance indicators of individual workers. A first application of such a method in the Civil Service shows positive effects of training. However, the size of the effects should not be overrated.
Is the Preference for Children so Low, or is the Price of Time so High? A simultaneous model of fertility and participation in Italy with cohort effects
Authors: Colombino Ugo , Di Tommaso Maria Laura
Published: June 2007

ABSTRACT: This paper presents a simultaneous model of fertility and female participation in Italy, estimated with a sequence of cross‐sections of micro data. Cohort dummies are used to capture permanent effects, including cohort changes in preferences. The cohort effects turn out to be not very significant, the point estimates suggesting a decreasing trend in participation and an increasing trend in fertility. The wage effects are instead rather strong and significant. The model produces simulations which are close to actual trends, which would seem largely explained by wage incentives. The explanation for a particularly high elasticity of fertility with respect to female wage should ultimately be searched for in the specific differences which characterize the Italian social and institutional environment.
Children and Gender — Wage Differentials
Authors: Tanda Paola , Bottone Germana
Published: June 2007

ABSTRACT: In this paper we present a test of wage discrimination between women and men in Italy, controlling for individual productive characteristics. We emphasise the importance, in empirical tests of wage discrimination, of explicitly modelling the reproductive role of women within the family. We show that ignoring the impact on women wages of the presence of children can seriously bias the results in favour of the hypothesis of wage discrimination. Our results illustrate that a considerable wages gap exists, but that only part of the observed differential can be attributed to pure discrimination; the remainder is explained either by heterogeneous productivity of men and women or by the effect of having children on female human capital formation.
Caring for Preschool Children in Urban Brazil
Authors: Connelly Rachel , DeGraff Deborah S. , Son Deborah Levi
Published: June 2007

ABSTRACT: This paper examines modes of child care choice for young children in urban Brazil. Analysis of child care in developing countries is rare, in spite of its relevance to many policy issues. We model child care choice as a function of characteristics of the child and the mother, including the mother's predicted wage and probability of employment, the presence of other young children and potential caregivers. The results highlight the importance of the institutional structure of the labour market and the formal child care market and reveal policy‐relevant information regarding the allocation of child care responsibility among household members.
Hepatitis B vaccination after living donor liver transplantation
Authors: Soejima Yuji , Ikegami Toru , Taketomi Akinobu , Yoshizumi Tomoharu , Uchiyama Hideaki , Harada Noboru , Yamashita Yoichi , Maehara Yoshihiko
Published: June 2007

Background: The efficacy of hepatitis B vaccination after living donor liver transplantation (LDLT) in patients transplanted anti‐HBc‐positive grafts or in patients who underwent LDLT for fulminant hepatitis B remains unknown.

Method: A total of 11 recipients who underwent LDLT between October 1996 and October 2002 prospectively received hepatitis B vaccination three times within 6 months, starting a few weeks after the cessation of hepatitis B immunoglobulin (HBIG) prophylaxis. Serial quantification of the hepatitis B surface antibody (HBsAb) was performed.

Results: At the last follow‐up, six out of 11 patients (54.5%) had seroconversion and were free from HBIG thereafter. Four out of those six responders had a peak HBsAb level of more than 1000 IU/L, while the other two patients had peak HbsAb levels below 1000 IU/L. Five patients never responded to the treatment and were back to HBIG prophylaxis. The average age of the six responders was 25.5 years, which was significantly younger than that of non‐responders (44.4 years, P<0.05). None had side effects or hepatitis B infection during the study period.

Conclusions: In conclusion, the use of this treatment modality could be used to reduce the cost of HBIG.
Body Size Variation of Mammals in a Fragmented, Temperate Rainforest
Authors: LOMOLINO MARK V. , PERAULT DAVID R.
Published: June 2007

Abstract:  Body size is perhaps the most important trait of an organism, affecting all of its physiological and ecological processes and, therefore, fundamentally influencing its ability to survive and reproduce in different environments, including those that have been modified by human activities. We tested the hypothesis that anthropogenic transformation of old‐growth forest landscapes can result in significant intraspecific changes in body size of resident biotas. We collected data on five species of nonvolant mammals (common deer mouse[Peromyscus maniculatus], northwestern deer mouse[P. keeni], southern red‐backed vole[Clethrionomys gapperi], montane shrew[Sorex monticolus], and Trowbridge's shrew[S. trowbridgii]) to test whether body size (mass and length) of these species varied across types of land cover (macrohabitats) and along elevational gradients of the fragmented, temperate rainforest of Olympic National Forest (Washington, U.S.A.). We measured 2168 and 1134 individuals for body mass and body length, respectively. Three species (P. keeni, S. monticolus, and S. trowbridgii) exhibited significantly different body size among macrohabitats: individuals from fragments were smaller than those in old‐growth corridors and those in more extensive stands of old‐growth forest. Body size of P. keeni was significantly correlated with elevation along corridors, peaking near the medial reaches of the corridors. The effects of anthropogenic transformations of this landscape of old‐growth, temperate rainforest, although not universal among the five species, were significant and rapid—developing in just a few decades following tree harvests. Thus, anthropogenic fragmentation may influence not only the diversity, species composition, and densities of local biotas, but also one of the most fundamental and defining characteristics of native species—their body size.
A Biological Framework for Evaluating Whether a Species Is Threatened or Endangered in a Significant Portion of Its Range
Authors: WAPLES ROBIN S. , ADAMS PETER B. , BOHNSACK JAMES , TAYLOR BARBARA L.
Published: June 2007

Abstract:  Under the U.S. Endangered Species Act (ESA), a species can be listed if it is at risk “in all or a significant portion of its range,” but the ESA provides no guidance on how to interpret this key phrase. We propose a simple test to determine whether the areas of a species' range in which it is currently at risk amount to a significant portion: If the species were to become extirpated from these areas, at that point would the entire species be at risk? If so, then these areas represent a significant portion of the species' range. By establishing the species itself as the point of reference for determining significance, this test directs attention to biological risk factors and avoids difficulties inherent in subjective evaluations of importance to humans. For broadly distributed species this framework could provide ESA protection due to cumulative risks before the entire species met the criteria to be considered threatened or endangered. This framework also allows a somewhat broader concept of range to include major components of diversity necessary for long‐term persistence. The concept of a historical template (i.e., conditions under which the species was known to be viable) is important in providing a fixed reference point for evaluating viability. Empirical examples illustrate how these concepts have been applied in recent ESA listing determinations. Most ESA‐listed units of Pacific salmon (Oncorhynchus spp.) can be divided into multiple strata that differ in terms of ecology, geology, or life‐history traits of the component populations. The goal of ESA recovery planning is to restore viable populations in enough strata that the listed unit as a whole is no longer threatened or endangered in all or a significant portion of its range. In a recent review of Pacific herring (Clupea pallasii) in Puget Sound, current status (some populations increasing and others declining) was evaluated in the context of the historical template, and it was concluded that current patterns of distribution and abundance do not depart substantially from what would be expected at any point in time under natural conditions in a large metapopulation. The Canadian lynx (Lynx canadensis) is ESA listed in the contiguous United States, where it occurs in four geographic areas. Populations in one region, the Northern Rockies/Cascades, have always been the most important for long‐term persistence of the species in the United States. Because the other regions never contained more than limited amounts of good‐quality lynx habitat, those areas are not considered to represent a significant portion of the species' range.
Prenatal Alcohol Exposure Affects Frontal–Striatal BOLD Response During Inhibitory Control
Authors: Fryer Susanna L. , Tapert Susan F. , Mattson Sarah N. , Paulus Martin P. , Spadoni Andrea D. , Riley Edward P.
Published: June 2007

Background: Prenatal alcohol exposure can lead to widespread cognitive impairment and behavioral dysregulation, including deficits in attention and response inhibition. This study characterized the neural substrates underlying the disinhibited behavioral profile of individuals with fetal alcohol spectrum disorders (FASD).

Methods: Children and adolescents (ages 8–18) with (n=13) and without (n=9) histories of heavy prenatal alcohol exposure underwent functional magnetic resonance imaging while performing a response inhibition (go/no‐go) task.

Results: Despite similar task performance (mean response latency, performance accuracy, and signal detection), blood oxygen level‐dependent (BOLD) response patterns differed by group. Region‐of‐interest analyses revealed that during portions of the behavioral task that required response inhibition, alcohol‐exposed participants showed greater BOLD response across prefrontal cortical regions (including the left medial and right middle frontal gyri), while they showed less right caudate nucleus activation, compared with control participants.

Conclusions: These data provide an account of response inhibition‐related brain functioning in youth with FASD. Furthermore, results suggest that the frontal–striatal circuitry thought to mediate inhibitory control is sensitive to alcohol teratogenesis.
Pre‐ and Post‐set Hydrophilicity of Elastomeric Impression Materials
Authors: Michalakis Konstantinos X. , Bakopoulou Athina , Hirayama Hiroshi , Garefis Dimitris P. , Garefis Pavlos D.
Published: June 2007

Purpose: To evaluate the hydrophilicity of one polyether, four poly(vinyl siloxanes), and one condensation silicone before and after setting under simulated clinical conditions, and to correlate the findings to the contact angle values of these materials.

Materials and Methods: The hydrophilicity before and after setting, as well as the contact angle values of the elastomeric impression materials were evaluated. Part I: A freshly extracted tooth, which was prepared for a full coverage restoration, was kept in saliva for 15 minutes and was then rinsed for 10 seconds. Impressions were taken without any drying of the tooth. A total of ten samples were taken for each material. The specimens were evaluated at a 10× magnification for defects. Part II: After the evaluation, the impressions were poured with a type IV dental stone and were left for 1 hour before separation. The stone specimens were then evaluated at a 10× magnification for negative voids. A total of 60 specimens were tested. Part III: Sixty identical 10 × 10 × 4 mm2 plastic molds were used for the fabrication of the impression material specimens. Contact angle measurements of each specimen were made 1 hour after separation from the plastic mold. A calibrated pipette was used to place a drop (0.05 ml) of saturated calcium sulfate dehydrate onto each specimen. Digital images were taken for each specimen, and contact angle values were measured with appropriate software.

Results: Part I: One‐way ANOVA revealed significant differences among the materials (F = 15.526, p < 0.0005). Polyether had the fewest voids. The poly(vinyl siloxanes) did not present any significant differences among them, according to Tukey's HSD test (p < 0.05). Part II: One‐way ANOVA revealed significant differences among the materials (F = 46.164, p < 0.0005). Polyether (Impregum) was the material which produced stone specimens with the fewest voids. Part III: One‐way ANOVA indicated significant differences among the elastomeric impression materials (F = 494.918, p < 0.0005). Polyether displayed the smallest contact angle values.

Conclusions:
Polyether was the most hydrophilic of all materials tested.
Politics and the Limits of a Science of Governance: Some Reflections on the Thought of Bernard Crick
Authors: Spicer Michael
Published: June 2007

This paper examines Bernard Crick’s ideas on the nature of politics and explores their implications for a scientific approach to governance like that advocated recently by public management writers. It is argued here that such an approach generally downplays the inherently political character of governance because it ignores the conflicts of values and the uncertainty that are an inherent part of the way in which we have come to govern ourselves.
Comparison of Complete and Incomplete Revascularization by Coronary Angioplasty for Unstable Angina
Authors: SMALL ROY S. , HOLMES DAVID R. , VLIETSTRA RONALD E. , REEDER GUY S. , BRESNAHAN JOHN F. , BRESNAHAN DENNIS R.
Published: June 2007

When a “culprit lesion” can be identified in a patient with unstable angina, it may be possible to achieve clinical improvement with incomplete revascularization. We analyzed actuarial survival free of an event (severe angina, myocardial infarction, coronary artery bypass graft, or death) at 6, 12, 18, and 24 months in 83 patients with multi‐vessel disease and unstable angina who had undergone successful percutaneous transluminal coronary angioplasty (PTCA); revascularization was complete in 31 patients and incomplete in 52. Event‐free survival in 85 patients with single‐vessel disease and unstable angina who had undergone successful PTCA also was analyzed. Event‐free survival at 24 months was worse in the multivessel disease patients than in the single‐vessel disease patients (62% vs 85%; P = 0.001). Multivessel disease patients with complete revascularization had the same event‐free survival as those with incomplete revascularization (63% vs 61%; P NS). Diagnostic angiograms revealed thrombus or an irregular ulcerated lesion in 42 of the multivessel disease patients. The event‐free survival of these 42 patients was not different from that of the multivessel disease patients as a whole (64% vs 60%; P NS). We conclude that in patients with multivessel disease and unstable angina the event‐free survival after PTCA is poorer than in patients with single‐vessel disease and unstable angina. In the former patients, event‐free survival does not necessarily depend on the completeness of revascularization. The outcome of patients who have intra‐coronary thrombus or an irregular ulcerated lesion resembles the outcome of patients who lack these findings. (J Interven Cardiol: 1988:1:1)
Assessment of Coronary Flow Reserve During Angioplasty Using A Doppler Tip Balloon Catheter. Comparison With Digital Subtraction Cineangiography
Authors: SERRUYS PATRICK W. , ZIJLSTRA FELIX , REIBER HANS H. C. , KONING RENE , ROELANDT JOS
Published: June 2007

Intracoronary blood flow velocity measurements with a Doppler probe and the radiographic assessment of myocardial perfusion with contrast media previously have been used to investigate regional coronary flow reserve. In the present study we applied both techniques in the same patients to measure the immediate improvement in coronary flow reserve as a result of angioplasty. In addition we compared papaverine induced hyperemia with reactive hyperemia following transient transluminal occlusion of a major coronary artery. In 13 consecutive patients with a single proximal stenosis, coronary flow reserve was measured pre‐ and postangioplasty by digital subtraction cineangiography, while pre‐ and postangioplasty Doppler measurements before and after papaverine were obtained in the proximal part of the stenotic vessel. After the last transluminal occlusion, reactive hyperemia recorded with the Doppler probe was also compared to the coronary flow reserve measurement obtained during papaverine induced hyperemia. As a result of the angioplasty, coronary flow reserve measured with the radiographic technique (mean ± SD) increased from 1.1 ± 0.4 to 2.2 ± 0.4 (P < 0.001), while coronary flow reserve measured with the Doppler probe (mean ± SD) increased from 1.2 ± 0.3 to 2.4 ± 0.4 (P < 0.001). Pharmacologically induced hyperemia measured with the radiographic technique and the Doppler probe were linearly related (r = 0.91 with a SEE 0.3) and confirmed the reliability of the intracoronary measurements. Using these two independent techniques, coronary flow reserve immediately after angioplasty was found to be substantially improved but still abnormal. In addition, the magnitude of hyperemia induced by papaverine was comparable to the reactive hyperemia following transluminal occlusion, although the latter measurement was recorded with the angioplasty catheter still across the dilated lesion. (J Interven Cardiol, 1988:1:1)
The Excimer Laser: Current Knowledge and Future Prospects
Authors: FORRESTER JAMES S. , LITVACK FRANK , GRUNDFEST WARREN , MOHR FRIEDRICH W. , PAPAIOANNOU THANASSIS , GOLDENBERG TSVI , LAUNDENSLAGER JAMES
Published: June 2007

We have developed a complete excimer laser and fiber‐optic angioplasty system and successfully opened completely occluded blood vessels in humans. We use the 308 nm XeCL excimer laser and fiber‐optic delivery system that can be passed through a catheter or over a guidewire. In this article, we describe the knowledge essential for the interventionalist using the device: the method for generating 308 nm laser light, laser‐tissue interaction, healing after laser injury, and how the rate of laser ablation is controlled. Our initial experience using the excimer laser in the superficial femoral artery has been excellent. (J of Interv Cardiology; 1988;1:1)
Utility of Continuous Measurement of Pulmonary Artery Oxygen Saturation During Episodic Myocardial Ischemia in Patients
Authors: KERN MORTON J. , AGUIRRE FRANK , SHAH YOGESH , GABLIANI GREGORY , DELIGONUL UBEYDULLAH , BODET JOSEPH , VANDORMAEL MICHEL
Published: June 2007

The use of continuously monitored pulmonary artery oxygen saturation (PAOS)for the assessment of transient myocardial ischemia was examined in a controlled human model during coronary angioplasty, producing brief reversible episodes of myocardial ischemia. Clinical and anatomic variables were prospectively recorded and correlated with changes in continuous PAOS during repeated episodes of coronary artery occulsion. Forty‐seven patients underwent left anterior descending (LAD, n = 43) or circumflex (n = 4) coronary balloon occlusion. Patients were subgrouped by PAOS responses: group 1, 22 patients with ± 10% drop in PAOS during balloon inflation and group 2, 25 patients in whom the PAOS signal was stable or only minimally affected during transient ischemia. Anatomical features analyzed included normal coronary diameter, location of lesion (e.g., proximal to the first septal branch) and extent of myocardium supplied by an occluded artery (LAD extending beyond the apex of the left ventricle [LV] or a large diagonal after the occlusion point). Left ventricular wall motion abnormalities, presence of other coronary artery disease, diabetes and hypertension were also analyzed. Groups were similar with respect to age (61 ± 13, 62 ± 10 years), LV ejection fraction, LV score, incidence of hypertension and diabetes or anatomic scores (2.2 ± 1.0, for group 1 vs 2.0 ± 0.9 for group 2), normal angiographic arterial diameter and presence of coronary collateral supply.

Although some episodes of myocardial ischemia in electively studied stable patients may be associated with significant reducitons in PAOS, the occurrence or degree of PAOS reduction is not predicted by coronary anatomy, LV function or other clinical variables. Use of PAOS to identify ischemic events in more critically ill patients is potentially useful, but must be assessed individually during the clinical situation. (J Interven Cardiol 1988:1:2)
Laser Angioplasty of Totally Occluded Superficial Femoral Arteries Via a Percutaneous Popliteal Approach
Authors: SIRAGUSA VINCENT , BOWERS JOHN A. , THOMAS HARRY M.
Published: June 2007

Percutaneous laser hot‐tip recanalization of totally occluded superficial femoral arteries has previously been dependent on access to the superficial femoral artery via the common femoral artery. Certain subsets of disease do not permit this approach and thus make patients ineligible for this nonsurgical option. In order to extend the benefits of laser angioplasty to these patients, we have investigated the applicability of percutaneous popliteal artery puncture as an access point from which superficial femoral artery percutaneous laser balloon angioplasty can be performed. Twenty‐one procedures were performed on 20 patients with total superficial femoral artery occlusions. Eighteen had successful recanalization (85%). All 18 recanalized vessels were patent at 3 weeks post procedure. Minor complications which did not require surgical or medical intervention occurred in nine patients. We concluded that a percutaneous popliteal approach to laser angioplasty of a totally occluded superficial femoral artery can be safe and effective in selected patients.
Percutaneous Balloon Aortic Valvuloplasty: The State of the Art. A Review of Two Years Experience in Rouen
Authors: CRIBIER A. , GERBER L. , BERLAND J. , GAMRA H. , KONING R. , ELTCHANINOFF H. , LETAC B.
Published: June 2007

Since the first case performed by us in September 1985, percutaneous transluminal aortic valvuloplasty (PTAV) has been applied in Rouen in a broad clinical spectrum of patients with aortic stenosis. After our encouraging initial experience, there have been changes in our objectives and technique which have allowed us to proceed more quickly, with less discomfort to the patient, lower risk, and improved results. The development of a new device, a triple lumen‐double size balloon catheter has been a major advance as well as the use of extra‐stiff guidewires and arterial sheaths.

Our series has grown to more than 300 patients, mostly elderly (mean age 73 ± 11, 25% at or above 80) and very ill (71% in NYHA functional class HI or IV). Indication for PTA V was either absolute contraindication to valve replacement (30%), increased surgical risk (31%), refusal of surgery (10%), or attempt to postpone surgery (29%).

The largest balloon size used has been 20 mm or above (23 mm or even 25 mm) in 70% of the cases. The double‐balloon technique has been used in only 5% of the cases. In our series, PTAV resulted in a decrease in transvalvular peak gradient from 71 ± 26 mm Hg to 28 ± 13 mm Hg and an increase in aortic valve area from 0.54 ± 0.18 cm2 to 0.96 ± 0.33 cm2. With gained experience and the use of larger balloon sizes, the results have clearly improved: in the last 100 patients a valve area to or above 1 an2 has been obtained in 55% compared to 30% of the cases in our early experience. Patients less than 70 years old had the best results but the aortic stenosis was less severe before PTAV.

The total procedural and post‐PTA V mortality was 4% and involved primarily very old patients. The nonfatal complication rate remained low. Clinical information for 204 patients followed for 12 ± 5 months has been obtained and repeat catheterization has been done in 56 patients at an average of 4.5 months after PTA V.

The data confirms that PTA V is feasible and can be accomplished with a relatively low risk in an elderly and ill population and in patients with contraindication to valve replacement or very high surgical risk. The procedure alters the natural history of the disease in these patients, improving both symptoms and survival. Indications in other categories of patients deserve further studies.
Validation of A New Femoral Venous Method of Endomyocardial Biopsy. Comparison with Internal Jugular Approach
Authors: ANASTASIOU‐NANA MARIA I. , SORENSEN SHERMAN G. , FOWLES ROBERT E. , ALLISON SCOTT B. , NANAS JOHN N. , ANDERSON JEFFREY L.
Published: June 2007

Endomyocardial biopsy is a reliable and reproducible technique to confirm or establish a clinical diagnosis in many cases of idiopathic heart muscle disease. Our overall experience of 243 consecutive nontransplant related biopsy procedures (combined experience of previously reported and current series) comparing a new femoral venous (n = 94) with a standard internal jugular venous (n = 149) approach is reviewed. In the current series, the femoral (n = 59) and the internal jugular (n = 80) approaches, performed on 139 consecutive nontransplant‐related procedures (466 myocardial samples), were compared. Vascular access was achieved in all femoral procedures; the internal jugular vein could not be located in 4% (three) of neck approaches (P = NS). Myocardial sampling was sufficient in all internal jugular procedures; sampling was adequate in all femoral procedures except two (3%, P = NS). Two cases of hematoma were observed after an internal jugular approach. Pericardial effusion was observed in one patient after femoral and in one patient after internal jugular approaches (P = NS), and in the latter case, tamponade developed requiring intervention. Transient atrioventricular block (complete in 2 and 2:1 in 1) developed in three patients (femoral procedures), but all of these patients had shown predisposing complete left bundle branch block on their electrocardiogram. No difference in vascular access, sampling efficiency and complication rate between our previous and current series regarding the internal jugular and femoral approaches was observed. Our overall experience with the femoral and internal jugular approaches was similar for complication rate (1% in both). Vascular access was better overall with the femoral approach (100% vs 93%, P <0. 01), reflecting more difficulty with internal jugular access in the first series. Thus, the femoral venous approach described is comparable in efficacy and safety to the standard internal jugular approach and may be especially useful as an alternative to right ventricular biopsy when the internal jugular vein cannot be successfully cannulated or when a cardiac catheterization from the femoral area is being performed at the same time for other reasons.
Transcatheter Modulation of Atrioventricular Nodal Conduction by Radiofrequency Current
Authors: KUNZE KLAUS‐PETER. , SCHLUTER MICHAEL. , GEIGER MANFRED. , KUCK KARL‐HEINZ.
Published: June 2007

A new technique is presented in which atrioventricular (A V) nodal conduction properties can be altered in a controlled way through the application of radiofrequency current. In 13 patients with supraventricular arrhythmias (maximal heart rate 215/min) radiofrequency current was delivered to the A V node via a catheter. Nine patients had atrial fibrillation, three had A V nodal reentrant tachycardia, and one patient had accessory pathway mediated A V tachycardia. Radiofrequency current application in these patients increased AV nodal conduction time and antegrade A V nodal effective refractory period significantly. In three patients radiofrequency current had no effect, and the A V node was ablated with direct current shocks. During a mean follow‐up period of 10 ± 3 months, all ten patients in whom radiofrequency current application had been successful were asymptomatic without antiarrhythmic medication. No complications were observed, neither during nor after the procedure.
Transcatheter Atrial Septal Defect Closure: Preliminary Experience with the Rashkind Occluder Device
Authors: BEEKMAN ROBERT H. , ROCCHINI ALBERT P. , SNIDER A. REBECCA , ROSENTHAL AMNON
Published: June 2007

The early experience at the University of Michigan with the Rashkind ASD occluder in three children with a secundum atrial septal defect (ASD) is reported. Successful transcatheter ASD closure was accomplished in one child. The procedure was not successful in the other two. In one, the ASD occluder was inadvertently implanted in the right atrium. The ASD was successfully closed in the other child, but the occluder device partially detached from the atrial septum 4 days later and required emergency surgical retrieval from the left atrium. Based on this early experience, revisions in the occluder device and the technique of its delivery are suggested that should improve the safety and efficacy of transcatheter ASD occlusion in the future.
Retrograde Coronary Angioplasty of Native and Branch Vessels Via a Vein Bypass Graft
Authors: DISCIASCIO GERMANO , GOUDREAU EVELYNE , COWLEY MICHAEL J.
Published: June 2007

A case of retrograde coronary angioplasty of native and branch vessels in a patient with prior bypass surgery is presented. The procedure was performed through the vein graft. This unusual, complex approach was employed due to inaccessibility of the lesion antegrade via the native vessel. (J Interven Cardiol 1989:2:1)
Transesophageal Echocardiography: Current Indications
Authors: PAVLIDES GREGORY S. , HAUSER ANDREW M. , O'NEILL WILLIAM W. , TIMMIS GERALD C.
Published: June 2007

Transesophageal echocardiography is rapidly gaining acceptance among the medical community with the number of accepted indications increasing. Used in conjunction with the transthoracic examination, the transesophageal approach provides a complementary means for evaluating a wide variety of cardiac pathology. It is uniquely suited to evaluate pathology in the aortic root and left atrium, including valves or their prosthetic replacement. Although transesophageal echocardiography cannot be considered a noninvasive examination, patient discomfort and risk are generally low. An experienced echocardiographer may quickly achieve proficiency in the examination following instruction in passage of the transducer and orientation to the imaging methodology. The often spectacular display of anatomy fosters confidence in the data and enhances acceptance by other physicians and especially surgeons who may be called upon to act on the findings.
Reopening of Chronic Coronary Artery Occlusions by Low Speed Rotational Angioplasty
Authors: KALTENBACH MARTIN , VALLBRACHT CHRISTIAN
Published: June 2007

Following successful application in chronic peripheral artery occlusions, rotational angioplasty was refined and miniaturized for application in patients with chronic coronary artery occlusions. The new catheter system comprises a motor‐driven rotating inner steel catheter made up of several steel coils providing maximum elasticity and complete torque control with an olive‐like rounded tip (1.0–1.7 mm). The catheter has a lumen for contrast injection and a shielding plastic tube. It is introduced through a conventional 8 Fr guiding catheter. The slowly rotating (200 RPM) catheter passes nontraumatically through the occlusions, thus creating a new channel with smooth contours in a “remodeling” fashion. Once the channel (diameter 1–1.5 mm) is confirmed angiographically, balloon angioplasty is performed over an exchange wire in conventional technique. The new technique was applied to patients with chronic coronary occlusions. Reopening was first attempted with conventional guidewire technique. If the occlusion could be probed with the guidewire, patients were excluded from the study. Twenty patients in whom the occlusion could not be probed with a wire were studied: 1 ACVB, 2 LAD, and 17 RCA. Average duration of occlusion was 7.4 months; it exceeded 3 months in 15/20 and 6 months in 12/20 patients. Successful reopening was achieved in 9/20 (3 from the first 10, 6 from the second 10 patients). No vessel wall perforation or any other severe complication was encountered. Residual stenosis diameter ranged from 30%–70%. Duration of occlusion was similar among patients from the successful and unsuccessful group. It is concluded that with low speed rotational angioplasty reopening of chronic coronary artery occlusions can be achieved in a considerable part of patients in whom conventional technique is unsuccessful. (J Interven Cardiol 1989:2:3)
The Relationship Between Intimal Tears During Coronary Angioplasty and Fibrinopeptide A
Authors: JAMES KAREN B. , BRODSKY MARC S. , SCHLUCHTER MARK D. , WHITLOW PATRICK L. , LUCAS FRED V. , HOLLMAN JAY L.
Published: June 2007

Arterial injury during routine percutaneous trans‐luminal coronary angioplasty (PTCA) may stimulate clotting mechanisms. Excessive (i.e., angiographically visible) arterial trauma might accordingly predispose to a greater tendency for thrombosis. This study evaluates whether arterial trauma (i.e., angiographically visible intimal tears and arterial dissections) is related to evidence of active thrombosis. Fibrinopeptide A (FPA), a sensitive marker of thrombin activity, was measured in 79 patients undergoing elective PTCA immediately following angioplasty, as well as prior to hospital discharge (mean 2 days post‐PTCA). Levels > 2.0 ng/mL were considered elevated. Intimal tears were visualized in 41 patients. Of these 41, 31 had elevated FPA levels (sensitivity = 0.76). This association between FPA elevation and intimal tears was significant (P = 0.033). Of the remaining 38 patients without intimal tears, 20 had elevated FPA levels (specificity = 0.47). Concomitant arterial dissection, as well as an intimal tear, was found in four patients with elevated FPA and in one patient with normal FPA. Conclusion. Arterial trauma during PTCA is accompanied by a greater degree of ongoing thrombosis. Although FPA elevation was not specific for intimal tears, a highly significant association with intimal tears was observed. Further study may yield even more specific hematologic parameters on ongoing early thrombosis following PTCA, particularly in patients with intimal tears. (J Interven Cardiol 1989:2:3)
Efficacy and Safety of Thrombolysis with Intravenous Streptokinase Initiated Prior to Ambulance Transport from Community Hospital to Tertiary Health Care Center
Authors: MANGER VOLKERT , BOSKER HANS A. , OEMRAWSINGH PRANOBE V. , VAN DER LAARSE ARNOUD , BRUSCHKE ALBERT V. G.
Published: June 2007

We studied the safety and efficacy of thrombolytic therapy for acute myocardial infarction initiated prior to ambulance transport. Two treatment regimens were compared in a prospective design: 40 patients (group A) received intravenous streptokinase 5 ± 105 IU (SK‐IV) prior to and during ambulance transport and were compared with 36 patients (group B) in whom the same dosage of streptokinase was given after arrival in our hospital. In all patients immediate coronary angiography was performed, followed by intracoronary streptokinase administration. Infarct size was assessed by cumulative release of α‐hydroxybutyrate dehydrogenase. Apart from three episodes of ventricular fibrillation no procedure‐related complications occurred during transport. Median time to SK‐IV was 70 minutes in group A versus 125 minutes in group B (P < 0.001). At first visualization the infarct‐related vessel was patent in 23 patients (58%) in group A and in 6 patients (17%) in group B (P < 0.001). Anterior wall infarction median infarct size in group A was 32% smaller than that in group B (P < 0.05). We conclude that SK‐IV started before ambulance transport is safe, accelerates early reperfusion rate, and consequently leads to a further limitation of infarct size in patients with anterior wall infarction. (J Interven Cardiol 1989:2:3)
Successful Recanalization Using a Hydrophilic‐Coated Guide Wire in Total Coronary Occlusions After Unsuccessful PTCA Attempts with Standard Steerable Guide Wires
Authors: HOSNY AYMAN A. , LAI DONALD M. , MANCHERJE CYRUS. , LEE GARRETT.
Published: June 2007

During a balloon angioplasty procedure, cardiac interventionalists frequently have difficulty passing standard guide wires into coronary arteries with chronic total occlusion. In the past year, we encountered eight patients with occluded coronary arteries where standard guide wires were tried (average duration 15.5 minutes) but were unsuccessful. Application of a 0.025–0.035‐inch hydrophilic guide wire was then attempted and was successful in recanalizing seven of the eight coronary occlusions (average duration 3.9 minutes). The channel created by the hydrophilic guide wire remained patent after its removal and permitted subsequent balloon angioplasty to be performed. Thus, in some patients with coronary occlusion where difficulty in guide wire passage is encountered, the application of a hydrophilic guide wire for crossing the occlusion and facilitating PTCA should be considered. However, a larger clinical series will be needed to determine the safety and efficacy of this technique.
Internal Cardioversion of Chronic Atrial Fibrillation
Authors: LÉVY SAMUEL
Published: June 2007

Chronic atrial fibrillation (AF), a common arrhythmia in clinical practice presents the danger of systemic embolization and an untoward effect on cardiac function. Furthermore, in occasional patients symptoms related to rapid ventricular response, resistant to bradycardiac agents, may lead to electrical ablation of the atrioventricular junction. A new technique of internal cardioversion of AF is described. It consists of delivering high energy shocks (200–400 joules) between the proximal electrode of a quadripolar catheter (cathode) and a backplate (anode). The catheter is positioned in the tricuspid valve area and pulled back just inferior to the site of the His bundle recording. This technique was performed in 24 patients. In all patients external cardioversion failed to restore sinus rhythm. All patients complained of symptoms despite antiarrhylhmic therapy. Sinus rhythm was restored by internal cardioversion in 20 of the 24 patients (83%). However, AF recurred in 7 of the 20 patients before hospital discharge. The only complication noted was transient atrioventricular block in 9 patients treated with prophylactic ventricular pacing. Of the 13 patients who were in sinus rhythm at the time of hospital discharge, 6 patients (46%) remained on stable sinus rhythm. Recurrence of atrial fibrillation was noted in the remaining 7 patients, in 4 within the first 4 months and in 3 patients 8, 9 and 18 months, respectively, after the procedure. A second attempt of internal cardioversion was performed in 3 and was successful in 2. With a follow‐up ranging from 13 to 37 months (mean 25 months), 6 patients (49%) are in sinus rhythm. This study suggests that internal cardioversion may be useful in selected patients with chronic AF.
Damage to Cardiologists’Gloves During Cardiac Catheterization, Pacemaker Implantation, and Percutaneous Transluminal Coronary Angioplasty
Authors: RHODEN WALTER E. , LEVY RICHARD , BENNETT DAVID H.
Published: June 2007

Glove perforation during catheter laboratory procedures exposes the operator to potentially infected fluids and the patient to wound infection. To assess the extent of this problem, 200 consecutive pairs of surgical gloves worn during cardiac catheterization, percutaneous transluminal coronary angio‐plasty (PTCA), or permanent transvenous pacemaker (PPM) insertion were examined for perforations by a water distension test. The overall puncture rate for pairs of gloves was 18%. The rate of glove puncture differed between cardiac catheterization, PPM implantation, and PTCA (21.4%, 25.6%, and 4.8%, respectively; P = 0.018). The incidence of glove damage at cardiac catheterization was significantly higher when arterial access was obtained by a brachial cut‐down rather than by the Seldinger technique (25.7% and 11.3%, respectively; P = 0.015) and was independent of operator experience. Glove perforation is common. Operators should be aware of the problem and be particularly vigilent during brachial arteriotomy and PPM implantation, especially when operating on potentially infected patients. (J Interven Cardiol 1991; 4:167–170)
The Influence of Balloon Inflation Duration on the Acute Angiographic Result of Percutaneous Transluminal Coronary Angioplasty
Authors: GARRAHY PAUL J. , DEAN LARRY S. , BULLE THOMAS M. , ANDERSON JOAN C. , BAXLEY WILLIAM A. , NATH HRUDAYA
Published: June 2007

This study was performed to evaluate the importance of the duration of balloon inflation during PICA, by comparing two common inflation durations. Patients were randomized to a 30‐second inflation protocol (group I, 83 procedures, 109 lesions), or a 60‐second protocol (group II, 83 procedures, 115 lesions). There were no differences in baseline characteristics between the two groups, and no subsequent differences in mean inflation number (3.4 ± 1.6 vs 3.1 ± 1.6), residual stenosis (34%± 17% vs 33%± 16%), presence of dissection (29% vs 34%), or clinical success (89% vs 84%), group I versus group II, respectively. The 30‐second inflations caused significantly less chest pain score (147 ± 239 vs 399 ± 516, P < 0.001), and ST segment alteration (75 ± 94 seconds vs 136 ± 163, P < 0.05). These results indicate that 60‐second inflations do not produce a superior result to 30‐second inflations. Furthermore, shorter inflations are much better tolerated.