bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation of high‐frequency (600 Hz) somatosensory‐evoked potentials after rTMS of the primary sensory cortex
Authors: Restuccia Domenico , Ulivelli Monica , De Capua Alberto , Bartalini Sabina , Rossi Simone
Published: September 2007

Somatosensory inputs to the primary sensory cortex (S1) after median nerve stimulation include temporally overlapping parallel processing, as reflected by standard low‐frequency somatosensory‐evoked potentials (LF‐SEPs) and high‐frequency SEPs (HF‐SEPs), the latter being more sensitive to arousal and to other rapid adaptive changes. Experimental data suggest that cortical HF‐SEPs are formed by two successive pre‐ and postsynaptic components, respectively, generated in the terminal part of thalamo‐cortical radiation (early burst) and in specialized neuronal pools within S1 (later burst).

In eight healthy subjects, slow (1 Hz) or rapid (10 Hz) repetitive transcranial magnetic stimulations (rTMS), which are known to induce opposite changes on cortical excitability, applied on S1 did not modify LF‐SEPs, while HF‐SEPs showed a series of dissociate changes in the early and later high‐frequency burst, moreover occurring with a different time‐course. Slow rTMS caused an immediate and lasting decrease of the later burst activity, coupled with an immediate increase of the earlier part of the burst, suggesting that inhibition of cortical excitability triggered opposite, compensatory effects at subcortical levels; rapid rTMS induced a delayed increase of later HF‐SEPs, leaving unaltered the earlier subcortical burst.

Findings causally demonstrate that LF‐ and HF‐SEPs reflect two distinct functional pathways for somatosensory input processing, and that early and late high‐frequency burst do actually reflect the activity of different generators, as suggested by experimental data. Possible underlying neurophysiological phenomena are discussed.
“Earn Your Penny Elsewhere”: Banishment, Migrant Laborers, and Sociospatial Exclusion in Sixteenth‐Century Ulm*
Authors: COY JASON P.
Published: September 2007

Abstract  The town council in Ulm, Germany banished over a thousand offenders in the course of the sixteenth century. Examination of the banishment verdicts issued by these magistrates reveals how they used expulsion to regulate both the physical borders of their territory and inclusion in the urban commune. In banishment cases involving resident aliens, the local authorities sought to expel resident aliens who seemed to threaten the community's property or its purity, using purgation to police the margin between legal and physical inclusion and exclusion. Finally, the local magistrates used the public expulsion rituals that accompanied banishment to display their role in regulating these boundaries before their subjects.
Transmutation, Inclusion, and Exclusion: Political Arithmetic from Charles II to William III1
Authors: McCORMICK TED
Published: September 2007

Abstract  Political arithmetic, generally understood as an early form of political economy, was originally designed by Sir William Petty in the 1670s less as a method of quantitative analysis than as a program of government through the direct manipulation of demographic processes. In the context of the English colonization of Ireland, its goal was “the transmutation of Irish into English”; under the Catholic James II it briefly became a program for the catholicization of the three Stuart kingdoms. Both projects undermined the national and religious categories associated with traditional exclusionist policy and fostered a radical inclusionism. Only after 1688 did Petty's successors decisively rearticulate political arithmetic as a putatively apolitical analytical tool.
An Eleventh‐Century View of Chinese Ethnic Policy: Sima Guang on the Fall of Western Jin
Authors: STRANGE MARK
Published: September 2007

Abstract  At the start of the fourth century, China's Western Jin dynasty (265–317 AD) faced insurrection from non‐Chinese ethnic groups that resided as its internal clients. It fell to these barbarian usurpers in 317. Throughout the eleventh century, the Northern Song dynasty (960–1127) felt its sovereignty endangered by foreign states to the north. Parallels between the ethnic policies of Western Jin and Northern Song emerge from the representation of Western Jin's dynastic fortunes that the eleventh‐century statesman and historian Sima Guang (1019–1086) offered in his famous chronicle, Zizhi tongjian (A Comprehensive Mirror to Aid Government). The present article takes that text as its focus. It examines the textual and ideological spin that Sima Guang gave his account of fourth‐century ethnic tensions. It argues that his characterisation of the barbarians that threatened Western Jin resonated with his response to eleventh‐century foreign relations. And it shows that for Sima Guang the integrity of the Chinese imperial state, and even Chinese identity, was at stake.
Corporate Boards and Company Performance: review of research in light of recent reforms
Authors: Finegold David , Benson George S. , Hecht David
Published: September 2007

Recent US corporate governance reforms introduced extensive regulations and guidelines for public corporations, particularly corporate boards. This article evaluates the extent to which empirical research on corporate boards and firm performance supports these reforms. Building on the meta‐analysis conducted by Zahra and Pearce (1989), we review 105 studies published between 1989 and 2005. We find most of the practices mandated by the Sarbanes‐Oxley Act of 2002, and the regulations issued by the New York Stock Exchange (NYSE) and the NASDAQ, had not been subject to prior study. Where board characteristics have been studied, we find limited guidance for policymakers on identifying governance practices that result in more effective firm performance. In an effort to increase the relevance of future research on boards and firm performance, we provide a framework on corporate boards.
The Relationship between Corporate Governance and Firm Productivity: evidence from Taiwan's manufacturing firms
Authors: Chiang Min‐Hsien , Lin Jia‐Hui
Published: September 2007

This study analyses the relationship between ownership structure and board of director composition and their influences on the total factor productivity (TFP) of Taiwan's firms. The empirical results show that the curvilinear specification is better to capture the relationship between inside ownership and firm productivity. Meanwhile, the ownership structure in a firm indeed affects differences in TFP between conglomerate firms and non‐conglomerate firms, high‐tech firms and non‐high‐tech firms, and family‐owned firms and non‐family‐owned firms. Additionally, a smaller board may be less encumbered by bureaucratic problems and more functional and CEO duality may be able to improve productivity. Furthermore, productivity deteriorates with increasing proportion of collateralised shares. More institutional holdings, however, are an effective way to alleviate the negative impact of collateralised shares on TFP.
Internal Governance in the Nonprofit Boardroom: a participant observer study
Authors: Parker Lee David
Published: September 2007

This paper presents the results of a longitudinal complete member researcher participant observer study of two nonprofit association boards with particular reference to their internal corporate governance processes. In doing so, it offers one of the very few available insider observational studies of boardroom behaviour currently available in the management literature. Its inductive analysis reveals boards that proactively manage director recruitment and selection, board member terms and rotation, with a strong emphasis on board membership diversity and representation. A clear progression from informal to formal processes of board and director performance evaluation are observed, and a variability in board–CEO relationships is explored. Agenda structuring changes are observed to directly impact upon strategy and policy focus, while informality and humour emerge as key weapons in the maintenance of cohesion in an increasingly business‐oriented environment. Boardroom culture emerges as a potent ingredient in the governance process, thereby signalling its future importance for both researchers and board chairs.
The Evolution of Corporate Governance: power redistribution brings boards to life
Authors: Anderson David W. , Melanson Stewart J. , Maly Jiri
Published: September 2007

To understand the evolving perspectives and behaviour of directors and institutional investors, field research was conducted in 2004–2005 by way of a survey with corporate directors in four countries (Australia, Canada, New Zealand and the United States; n = 658) and institutional investors in Canada (n = 34). Reported changes in directors' views and practices are substantial and consistent across countries, the defining characteristic of which is a fundamental shift in the positioning of the board toward becoming a strategic partner to management. The role of institutional investors also shifted in ways that are complementary to this new role of directors (e.g., toward increased monitoring). While most research has focused on agency concepts of the board as monitors of management, our research suggests that the board is evolving towards a more collaborative role with management, consistent with stewardship theory. Our findings also suggest that directors are seeking a balance between collaboration and their role as monitors of management, rejecting the notion of the board as primarily a monitoring body. An evolutionary model is offered to explain these changes and implications are discussed.
Onwards and Upwards: why companies change their executive remuneration schemes, and why this leads to increases in pay
Authors: Bender Ruth
Published: September 2007

This paper reports interview‐based research examining reasons for the continued increase in executive directors' remuneration in large UK companies. This issue has not specifically been addressed by previous studies, which have focused on the level of the increases, rather than their underlying explanations. Reasons given for making changes included: increases due to being below‐market; changing performance‐related schemes that did not pay out or paid less than expected; changes in the company's culture or strategy; changes to senior personnel; and compliance with good practice in human resource management and in corporate governance. The results are analysed through two theoretical lenses. Agency theory provides an explanation of the structure of the contracts; expectancy theory suggests why schemes might be changed to motivate the executives.
The Influence of Outside Directors' Stock‐Option Compensation on Firms' R&D
Authors: Deutsch Yuval
Published: September 2007

Using a sample of S&P 1500 firms between 1997 and 2000, this paper examines the effects of outside directors' stock‐option compensation on firms' R&D intensity. Results suggest that including stock options in outside directors' compensation enhances firms' R&D. Moreover, stock‐option compensation moderates the relationship between board composition and R&D intensity. These results suggest that outside directors' compensation schemes do matter. The results also highlight the need to re‐evaluate previous findings that addressed the effects of board composition on both firms' performance and strategic decisions.
Corporate Governance Reforms in Malaysia: the key leading players' perspectives
Authors: Liew Pik Kun
Published: September 2007

This paper focuses on the corporate governance reforms in Malaysia since the 1997/1998 Asian financial crisis. Drawing upon ten in‐depth semi‐structured interviews conducted with leading players who were highly involved in Malaysia's corporate governance development, together with a review of the literature in this area, the paper offers evidence on the meaning of corporate governance in the Malaysian context, the factors behind the recent reforms and views on the appropriate corporate governance system for Malaysia. While it is shown that Malaysia's corporate governance reforms has modelled on the Anglo‐American systems to a large extent, the majority of the interviewees placed greater emphasis on the social aspect of corporate governance in contrast to the traditional notion of shareholder accountability. The main concern raised in the paper is that without changes in the previous problematic corporate culture, the intended purpose of the recent corporate governance reforms will unlikely to be achieved.
The Effects of Ownership Structure and Board Composition on the Audit Committee Meeting Frequency: Spanish evidence
Authors: Méndez Carlos Fernández , García Rubén Arrondo
Published: September 2007

This paper examines the factors that affect the activity of the audit committees in Spain. The data used in the analyses are collected from the Spanish stock market in 2003. The results show the existence of a non‐linear relationship between the managerial stock ownership and the activity of the audit committee. We have also verified the existence of a lower audit committee's activity in highly leveraged firms and when the ownership structure is concentrated in the hands of large shareholders. The large firms have more active committees than small firms. Finally, we have not found any evidence of a significant influence of the composition of the board or the audit committee on the activity of the latter.
Developmental Instability and Individual Variation in Brain Development
Authors: Yeo Ronald A. , Gangestad Steven W. , Thoma Robert J.
Published: September 2007

Research on the origin of neurodevelopmental disorders has traditionally been pursued within a constrained, disorder-specific perspective. The developmental instability (DI) model described here offers a broader approach based on the evolutionary genetics of normal variation, reflecting our understanding that the processes generating genetic diversity are not unique to any specific disorder. The DI model helps account for shared features, including atypical functional and anatomic asymmetries, reduced general intellectual functioning, and complex patterns of heritability, across different types of neural variation. The model suggests research strategies that may help illuminate the specific and unique causal factors characterizing different types of neural variation.
Attention, Joint Attention, and Social Cognition
Authors: Mundy Peter , Newell Lisa
Published: September 2007

Before social cognition there is joint processing of information about the attention of self and others. This joint attention requires the integrated activation of a distributed cortical network involving the anterior and posterior attention systems. In infancy, practice with the integrated activation of this distributed attention network is a major contributor to the development of social cognition. Thus, the functional neuroanatomies of social cognition and the anterior–posterior attention systems have much in common. These propositions have implications for understanding joint attention, social cognition, and autism.
Does Estrogen Protect Against Cognitive Aging in Women?
Authors: Sherwin Barbara B.
Published: September 2007

Although there is evidence from randomized controlled trials that estrogen therapy protects against aspects of cognitive decline that occur with normal aging in women, findings from the Women's Health Initiative Memory Study and from some cross-sectional and longitudinal studies failed to find neuroprotective effects of estrogen in older women. There is growing empirical support for the critical-period hypothesis, formulated in the attempt to resolve these discrepancies. It holds that estrogen therapy has protective effects on verbal memory and on working memory only when it is initiated closely in time to menopause, whereas starting treatment many years following menopause does not protect and may even be harmful. Supporting evidence for this hypothesis from basic neuroscience and from animal and human studies is evaluated for its ability to explain the inconsistencies and to describe the conditions under which estrogen may protect cognitive function in aging women.
Entrepreneurial Academics: Developing Scientific Careers in Changing University Settings
Authors: Duberley Joanne , Cohen Laurie , Leeson Elspeth
Published: September 2007

This paper examines the impact of entrepreneurial initiatives within universities on scientific careers. Based on the career accounts of university‐based bioscientists involved in a government‐sponsored entrepreneurship training initiative, the paper explores the concept of academic entrepreneurialism. Three groups were identified in the data. First, academic entrepreneurs, who tended to be more experienced scientists and were now able to capitalise on their science. Second, those interested in technology transfer, who saw their career path taking them away from science, and finally a group of younger scientists who were trying to develop their career capital but were unsure what direction their career would take. The implications of these different groups for the management of universities and the development of knowledge are considered.
Institutional Diversity in Higher Education: a Cross‐National and Longitudinal Analysis
Authors: Huisman Jeroen , Meek Lynn , Wood Fiona
Published: September 2007

This paper contributes to the debate on institutional diversity in higher education systems by looking at the phenomenon from a comparative (cross‐national) and longitudinal perspective. Despite the attention to diversity in policy debates, surprisingly, only a limited amount of studies address methodological issues. In addition, the number of empirical studies on institutional diversity is low as well. Data on various Western higher education systems are used to illustrate developments in systems' diversity. Furthermore, these data are put in the context of current national (and supranational) policy debates, particularly the role of governments and markets, on maintaining or increasing diversity.
New and improved molecular sexing methods for museum bird specimens
Authors: BANTOCK TRISTAN M. , PRYS‐JONES ROBERT P. , LEE PATRICIA L. M.
Published: September 2007

We present two new avian molecular sexing techniques for nonpasserine and passerine birds (Neognathae), which are more suitable for use with museum specimens than earlier methods. The technique for nonpasserines is based on a new primer (M5) which, in combination with the existing P8 primer, targets a smaller amplicon in the CHD1 sex‐linked gene than previously. Primers targeting ATP5A1, an avian sex‐linked gene not previously used for sex identification, were developed for passerines. Comprehensive testing across species demonstrated that both primer pairs sex a range of different species within their respective taxonomic groups. Rigorous evaluation of each method within species showed that these permitted sexing of specimens dating from the 1850s. For corn bunting museum specimens, the ATP5A1 method sexed 98% of 63 samples (1857–1966). The M5/P8 CHD1 method was similarly successful, sexing 90% of 384 moorhen specimens from six different museum collections (1855–2001). In contrast, the original P2/P8 CHD1 sexing method only identified the sex of less than half of 111 museum moorhen samples. In addition to dried skin samples, these methods may be useful for other types of material that yield degraded or damaged DNA, and are hence potential new sexing tools for avian conservation genetics, population management and wildlife forensics.
Ten polymorphic STR loci in the cosmopolitan reef coral, Pocillopora damicornis
Authors: STARGER CRAIG J. , YEOH SEAN S. R. , DAI CHANG‐FENG , BAKER ANDREW C. , DESALLE ROB
Published: September 2007

We report the development of 10 polymorphic molecular markers containing short tandem repeats in the cosmopolitan reef‐building coral, Pocillopora damicornis, an important model species for coral health, physiology, ecology, and genetics. The availability of polymorphic DNA markers in P. damicornis can act as impetus for investigations into inheritance and population genetics, as well as novel investigations into host‐symbiont ecology and evolution. Coral bleaching and gene flow studies performed with these markers can have direct conservation implications.
Presbyopia and heat: changes associated with aging of the human lens suggest a functional role for the small heat shock protein, α‐crystallin, in maintaining lens flexibility
Authors: Heys Karl R. , Friedrich Michael G. , Truscott Roger J. W.
Published: September 2007

Presbyopia, the inability to focus up close, affects everyone by age 50 and is the most common eye condition. It is thought to result from changes to the lens over time making it less flexible. We present evidence that presbyopia may be the result of age‐related changes to the proteins of the lens fibre cells. Specifically, we show that there is a progressive decrease in the concentration of the chaperone, α‐crystallin, in human lens nuclei with age, as it becomes incorporated into high molecular weight aggregates and insoluble protein. This is accompanied by a large increase in lens stiffness. Stiffness increases even more dramatically after middle age following the disappearance of free soluble α‐crystallin from the centre of the lens. These alterations in α‐crystallin and aggregated protein in human lenses can be reproduced simply by exposing intact pig lenses to elevated temperatures, for example, 50 °C. In this model system, the same protein changes are also associated with a progressive increase in lens stiffness. These data suggest a functional role for α‐crystallin in the human lens acting as a small heat shock protein and helping to maintain lens flexibility. Presbyopia may be the result of a loss of α‐crystallin coupled with progressive heat‐induced denaturation of structural proteins in the lens during the first five decades of life.
Is Sirt1 a miracle bullet for longevity?
Authors: Imai Shin‐ichiro
Published: September 2007

The Sir2 (silent information regulator 2) family of nicotinamide adenine dinucleotide‐dependent deacetylases has been implicated in the regulation of aging and longevity across a wide variety of organisms. Although controversial, Sir2 proteins have also been implicated as key mediators for the beneficial effects of caloric restriction (CR) on aging and longevity. In this issue, Bordone et al. report that transgenic mice in which the mammalian Sir2 ortholog Sirt1 is overexpressed mimic the physiological changes in response to CR. These findings have important implications for the development of CR mimetics and perhaps also for lifespan extension.
Non‐Surgical Salvage of Thrombosed Arterio‐Venous Fistulae: A Case Series and Review of the Literature
Authors: Moossavi Shahriar , Regan John D. , Pierson Eric D. , Kasey John M. , Tuttle Audrey B. , Vachharajani Tushar J. , Bettmann Michael A. , Russell Gregory B. , Freedman Barry I.
Published: September 2007

Attempts to salvage thrombosed hemodialysis arterio‐venous fistulae (AVF) using interventional techniques are not universally performed. Patients often require temporary dialysis catheters pending creation of a new vascular access. We determined the long‐term outcome of interventional (non‐surgical) repair of completely thrombosed AVF in 49 consecutive accesses (22 radio‐cephalic, 1 radio‐basilic, 19 brachio‐cephalic, and 7 brachio‐basilic) referred for an intervention within 48 hours of thrombosis. Subjects were 65% male (32), with mean ± SD age 63.7 ± 13.5 years (range 33–91), 51% African‐American (25), 47% Caucasian (23) and 65% had diabetes (32). Overall, 96% (47/49) of thrombosed AVF were salvaged with complications observed in four cases (two extravasations of contrast; two radial artery emboli), with no serious long‐term sequelae. Interventional procedures included 34 venous angioplasties, 11 venous angioplasties with stenting and two combined venous and arterial angioplasties. The primary and secondary patency rates for all salvaged AVF were 50.5 ± 8.7%, 72.5 ± 7.8% at 1 year, and 43.3 ± 10%, 55.4 ± 12.7% at 2 years, respectively. The median estimate to first intervention after the declot procedure was 14.7 months. The median estimate for continued function exceeded 23.1 months. There was no significant statistical difference in the primary (p = 0.73) and secondary patency rates (p = 0.057) for forearm vs. upper arm AVF. We conclude that interventional repairs should routinely be employed to salvage newly thrombosed AVF. The vast majority of these individuals can avoid receiving dialysis catheters or placement of a new dialysis vascular access.
“Raynaud's Disease” in Migraineurs: One Entity or Two?
Authors: Kaiser Ronald S.
Published: September 2007

SYNOPSIS

Two cases are reported of patients who were diagnosed as having both migraine and Raynaud's disease. Because they were able to achieve effective control of both headaches and extremity temperature after undergoing a comprehensive approach‐utilizing medication, biofeedback, and psychotherapy‐it is suggested that both conditions are manifestations of the same disorder. It is recommended that a first step in approaching concurrent diagnoses of this type involve combined treatment as is often used in response to the singular diagnosis of migraine.
Recurrent Syncope, Hypotension, Asthma, and Migraine With Aura: Role of Metoclopramide
Authors: Gupta Vinod K.
Published: September 2007

Migraine associated with asthma or symptomatic orthostatic hypotension is a particularly difficult subgroup to manage. Metoclopramide is a useful pharmacological agent for orthostatic hypotension. I present the case report of a migraine patient with asthma and recurrent hypotensive syncope. Metoclopramide relieved recurrent syncope as well as migraine attacks in this patient. Metoclopramide has a striking influence on arginine vasopressin (AVP) secretion. AVP promotes antinociception and influences vasomotor and behavior control, which actions possibly keep migraine in remission. Further studies are necessary to confirm the migraine prophylactic value of metoclopramide.
Reducing the risk of transfusion‐transmissible viral infection through blood donor selection: the Australian experience 2000 through 2006
Authors: Polizzotto Mark N. , Wood Erica M. , Ingham Helen , Keller Anthony J. ,   Australian Red Cross Blood Service Donor and Product Safety Team
Published: September 2007

BACKGROUND: Selection of voluntary donors who are at low risk of transfusion‐transmissible viral infection (TTVI) is central in maintaining the safety of the blood supply. Evaluation of its effectiveness and the dynamics of the process may offer opportunities to further improve transfusion safety.

STUDY DESIGN AND METHODS: The impact of donor selection on prevalence of TTVI was analyzed in all allogeneic donations in Australia between July 2000 and June 2006 by interviewing donors found to have a TTVI. The presence and disclosure of infective risks was reassessed.

RESULTS: A total of 6.3 million donations were tested; of these, 1449 (0.02%) were repeat‐reactive for a TTVI and were discarded. This comprised 605 (42%) positive for the presence of hepatitis B, 818 (56%) positive for the presence of hepatitis C, 18 (1%) positive for the presence of human immunodeficiency virus, and 20 (1%) positive for the presence of human T‐cell lymphotropic virus‐I and/or ‐II (HTLV‐I/II). This prevalence was 50 to 350 times lower than in the Australian population. In 1158 cases (80%), an infective risk was identified; 509 donors (44%) had more than one. The most common identified were country of birth and parental ethnicity (n = 682, 26% of risks), tattoos and/or piercings (n = 448, 18%), and intravenous drug use (n = 302, 12%). In 302 cases (21%) disclosure at predonation screening would have resulted in deferral. Factors influencing nondisclosure included temporal remoteness and perceptions that laboratory testing rendered disclosure unnecessary.

CONCLUSION: These findings affirm the effectiveness of current stringent donor selection criteria in reducing the residual risk of TTVI. Ongoing donor education regarding the importance of risk disclosure is required.
Understanding the meaning of permanent deferral for blood donors
Authors: Whittaker Susan , Carter Nancy , Arnold Emmy , Shehata Nadine , Webert Kathryn E. , DiStefano Lanis , Heddle Nancy M.
Published: September 2007

BACKGROUND:To ensure the safety of the blood supply, it is necessary to permanently defer blood donors with a repeat‐reactive transmissible disease test result. The purpose of this study was to explore the permanent deferral experience from the donor's perspective.

STUDY DESIGN AND METHODS:A qualitative study was conducted with donors from two Canadian blood centers who received written notice of permanent deferral in six deferral categories: human immunodeficiency virus‐1 and/or ‐2 and hepatitis C virus and/or hepatitis B virus (negative, indeterminate, or positive). Telephone interviews were conducted with a semistructured questionnaire. Interview transcripts were coded and central themes were identified. The data were then modeled to illustrate the relationships between the themes.

RESULTS:Twenty‐eight permanently deferred donors were interviewed and described a variety of negative emotional and behavioral responses including confusion, shock, disbelief, panic, fear, anger, stigmatization, and loss. A conceptual model was developed illustrating the phases that a deferred donor goes through (identifying as a healthy donor, receiving notification, experiencing emotional and behavioral reactions, trying to make sense of what happened, and taking action) as they travel along the path to becoming either a “reconciled” or “not reconciled” permanently deferred donor. Participants offered constructive suggestions for modifying the notification process including revising the letter, providing follow‐up, and educating family physicians.

CONCLUSIONS:To our knowledge, this is the first study to use qualitative research methodology to explore the experience of permanent blood donor deferral. More studies are needed to validate and expand this preliminary conceptual model.
A systematic review and survey of the management of unexpected neonatal alloimmune thrombocytopenia
Authors: Bassler Dirk , Greinacher Andreas , Okascharoen Chusak , Klenner Anne , Ditomasso Juliana , Kiefel Volker , Chan Anthony , Paes Bosco
Published: September 2007

BACKGROUND:Unexpected neonatal alloimmune thrombocytopenia (NAIT) may have devastating consequences and its management is challenging. To design future trials, evidence from the literature and existing best practice need review.

STUDY DESIGN AND METHODS:This study was a cross‐sectional survey of neonatal units in Germany and Canada to determine management strategies of NAIT and a systematic search for randomized controlled trials (RCTs).

RESULTS:Management of NAIT differs substantially between countries with regard to platelet (PLT) thresholds for screening, initiation of therapy, and treatment. Seventy‐seven percent of Canadian physicians versus 68 percent of German physicians screen preterm and term infants, at a PLT threshold of 30 × 109to 100 × 109per L. In preterm infants, 60 percent of Canadian neonatologists commence treatment at a PLT count of between 30 × 109and 50 × 109per L. In Germany 32 percent of the physicians start treatment at this level and 25 percent use a threshold of between 10 × 109and 20 × 109per L. In term infants, 6 percent of the Canadian physicians and 16 percent of the German physicians use even lower treatment triggers of between 5 × 109and 10 × 109per L. In the presence of bleeding, 61 percent of German physicians await the arrival of antigen‐negative PLTs, while 64 percent of Canadian neonatologists prefer intravenous immunoglobulin or random‐donor PLTs (81%). Maternal PLTs are utilized by 31 percent of physicians in both countries. No RCTs were identified.

CONCLUSION:In the absence of RCTs, management of unexpected NAIT differs between countries. Clinicians and transfusion services may use the results of our study to develop collaborative protocols, redefine preferred hospitalwide strategies, and design future controlled trials.
Prediction of Atrial Fibrillation with Atrial Late Potentials and Pathological Chemoreflexsensitivity
Authors: BUDEUS MARCO , HENNERSDORF MARCUS , REINSCH NICO , WIENEKE HEINRICH , SACK STEFAN , ERBEL RAIMUND
Published: September 2007

Background:

Atrial fibrillation (AF) is a very common arrhythmia that often causes the serious complication of a stroke.

Object:

The aim was to evaluate the utility of pathological chemoreflexsensitivity (PCHRS) and atrial late potentials (ALP) to predict AF in follow‐up.

Methods:

We investigated a prospective study on the basis of our observation about a PCHRS and ALP in paroxysmal AF. The PCHRS was predefined as a chemoreflexsensitivity below 3.0 ms/mmHg and ALP were predefined as a filtered P‐wave duration ≥120 ms and a root mean square voltage of the last 20 ms of the P‐wave ≤3.5 μV. A P‐wave triggered P‐wave signal averaged electrocardiograph (ECG) and chemoreflexsensitivity was performed on 250 consecutive patients who were divided into four groups. Group I consisted of patients with ALP and PCHRS, patients of group II had only ALP, a PCHRS was only present in group III, and patients of group IV had neither ALP nor PCHRS.

Results:

During the mean follow‐up of 37.8 months AF was observed in 10 patients (4%). The patients of the four groups were similar according to clinical baseline characteristics. The incidence of AF was higher in group I (18% of patients) than in group II (6% of patients, P = 0.229) and significantly higher than in group III (3% of patients, P = 0.034) or group IV (1% of patients, P < 0.0001). Patients with ALP and PCHRS showed a 33‐fold risk (P < 0.001) for the onset AF.

Conclusions:

The results of our study suggest that the probability of AF could be predicted with a P‐wave signal averaged ECG and an analysis of chemoreflexsensitivity. The predictive power of the combination of ALP and PCHRS seemed not high enough for risk stratification.
Use of a Retained Guidewire to Improve the Left Ventricular Pacing Threshold
Authors: SANKARANARAYANAN RAJIV , JAMES MICHAEL A.
Published: September 2007

Although transvenous access to the coronary veins has considerably simplified left ventricular (LV) pacing, it can remain a time consuming and arduous task achieving satisfactory pacing positions for the LV electrode. Common problems include negotiating small veins with adequate guide catheter stability, pacing electrode stability once positioned, and phrenic nerve stimulation. We report a case where use of the pacing lead guidewire resulted in a dramatic reduction in the pacing threshold of the LV lead, and saved the patient the need to undergo thoracotomy placement.
Multiplanar Visualization in 3D Transthoracic Echocardiography for Precise Delineation of Mitral Valve Pathology
Authors: Liang David , Paloma Allan , Kuppahally Suman S. , Craig Miller D. , Schnittger Ingela
Published: September 2007

A novel multiplanar reformatting (MPR) technique in three‐dimensional transthoracic echocardiography (3D TTE) was used to precisely localize the prolapsed lateral segment of posterior mitral valve leaflet in a patient symptomatic with mitral valve prolapse (MVP) and moderate mitral regurgitation (MR) before undergoing mitral valve repair surgery. Transesophageal echocardiography was avoided based on the findings of this new technique by 3D TTE. It was noninvasive, quick, reproducible and reliable. Also, it did not need the time‐consuming reconstruction of multiple cardiac images. Mitral valve repair surgery was subsequently performed based on the MPR findings and corroborated the findings from the MPR examination.
REVIEW: Aortic Atheromas: Current Concepts and Controversies—A Review of the Literature
Authors: Thenappan Thenappan , Ali Raza Jaffar , Movahed Assad
Published: September 2007

The frequent use of transesophageal echocardiogram (TEE) has led to the increased recognition of aortic atheromas. Retrospective and prospective follow‐up studies have reported an association between aortic atheromas and stroke in the high‐risk patient population, with complex plaques being more likely to embolize than simple plaques. However, TEE‐based studies in the low‐risk cohorts have failed to show a similar association. There is growing body of evidence suggesting that aortic atheroma is a marker of generalized atherosclerosis. Although magnetic resonance (MR) imaging and computed tomography (CT) scan are emerging as a powerful noninvasive tool for characterization of aortic atheromas, TEE is the imaging modality of choice. Currently, treatment of aortic atheromas is not well defined, and mixed outcomes have been reported for anticoagulation therapy with warfarin. Statins appear promising based on their plaque stabilization properties. However, there are no randomized control trials to establish the role of both anticoagulation and statins in patients with aortic atheromas, and are warranted in the future.
Mitral Annular Calcification as a Marker of Complex Aortic Atheroma in Patients with Stroke of Uncertain Etiology
Authors: Pujadas Ramón , Arboix Adrià , Anguera Núria , Rafel Josefa , Sagués Federico , Casañas Roser
Published: September 2007

The aim of this study was to evaluate the presence of dense mitral annular calcification as a marker of complex aortic atherosclerosis in patients with stroke of uncertain etiology. One hundred twenty‐one patients with stroke of uncertain etiology were evaluated for complex aortic atherosclerotic plaques; their presence and severity were correlated with transthoracic echocardiographic findings, demographic data, and cardiovascular risk factors. Complex plaques in the ascending aorta or aortic arch were found in 72 of the 121 patients (59.5%). The only difference seen in patients with or without plaques was the presence of dense mitral annular calcification (58.3 vs 16.3%; P < 0.001). Dense mitral annular calcification (n = 50) was associated with higher prevalence of complex aortic plaques (84.0% vs 42.3%; P < 0.001), mobile components (28.0% vs 9.9%; P < 0.01), and protruding (80.0% vs 36.6%; P < 0.001), ulcerated (16.0% vs 1.4%; P < 0.01), and multisite complex plaques (46.0% vs 9.0%; P < 0.001). Therefore, in patients with stroke of uncertain etiology dense mitral annular calcification is an important marker of aortic atherosclerosis with high risk of embolism, and this association may explain in part the high prevalence of stroke and peripheral embolism in patients with mitral annular calcification.
Multivalvular Infective Endocarditis in a Tetralogy of Fallot
Authors: Anwar Ashraf M. , Nosir Youssef F. M. , Ajam Aref , Mushtaq Maimoona , Alama Mohammed N. , Chamsi‐Pasha Hassan
Published: September 2007

Infective endocarditis (IE) is still a problem in patients with adult congenital heart disease. Tetralogy of Fallot (TOF) is one of the most important manifestations of congenital heart disease, which carries a high risk for the development of IE. We present an 18‐year‐old male with TOF complicated by an aggressive form of IE involving all cardiac valves.
Dialysis quality and quantity: How much and how often?
Authors: SPALDING Elaine , FARRINGTON Ken
Published: September 2007

Hemodialysis is accepted as standard therapy for end‐stage renal failure but despite four decades of experience the morbidity and mortality associated with the treatment remains unacceptably high. Quality of dialysis is traditionally measured with reference to urea clearance but it is becoming increasingly apparent that other solutes across the range of molecular size are also important. More prolonged or more frequent therapy may improve dialysis delivery and enhance survival in patients with end‐stage renal disease.
Dialysate calcium and calcium/phosphate balance in hemodialysis
Authors: HUTCHISON Alastair J.
Published: September 2007

The changing pattern of pharmaceutical use in dialysis patients has resulted in several alterations to dialysate calcium concentration over the past 40 years. Non‐calcium–containing phosphate binders and calcimimetics are the most recent examples of drugs that influence the overall calcium balance in dialysis patients. Renal osteodystrophy, vascular disease, and mortality are believed to be linked in patients with chronic kidney disease (CKD), although to date most of the evidence is based only on statistical associations. The precise pathophysiology of vascular calcification in end‐stage renal disease is unknown, but risk factors include age, hypertension, time on dialysis, and, most significantly, abnormalities in calcium and phosphate balance. Prospective studies are required before “cause and effect” can be established with certainty, but it is an active metabolic process with inhibitors and promoters. Serum calcium levels are clearly influenced by dialysate calcium and may therefore play an important role in influencing vascular calcification. Clinical management of hyperphosphatemia is being made easier by the introduction of potent non‐calcium–based oral phosphate binders such as lanthanum carbonate. Short‐term and long‐term studies have demonstrated its efficacy and safety. Vitamin D analogs have been a disappointment in the control of serum parathyroid hormone (PTH) levels, but evidence is emerging that vitamin D has other important metabolic effects apart from this, and may confer survival advantages to patients with CKD. Calcimimetics such as cinacalcet enable much more effective and precise control of PTH levels, but at the cost of a major financial burden. While it is unreasonable to expect that any one of these recent pharmacological developments will be a panacea, they provide researchers with the tools to begin to examine the complex interplay between calcium, phosphate, vitamin D, and PTH, such that further progress is fortunately inevitable.
Nephrogenic systemic fibrosis: A nephrologist's perspective
Authors: SAAB Georges , CHENG Steven
Published: September 2007

Nephrogenic systemic fibrosis (NSF) is a debilitating disorder that affects patients with renal insufficiency. Recent evidence suggests that the development of NSF may be related to the administration of gadolinium‐based contrast media (GBCM) in the setting of magnetic resonance imaging. As no treatment has consistently been effective in the management of NSF, strategies to prevent the development of this condition appear to be the best therapy. Identification of patients at greatest risk for developing NSF after exposure to GBCM is crucial. Risk factors include advanced chronic kidney disease (stages 4 and 5) and acute or chronic inflammatory events. The United States Food and Drug Administration has updated its public health advisory to include patients with moderate renal insufficiency (chronic kidney disease stage 3) as being at risk for developing NSF. However, these data require further verification and the vast majority of affected patients are already on renal replacement therapy. Another strategy in prevention may include consultation with a radiologist for imaging alternatives. If GBCM must be administered, immediate hemodialysis may be protective in patients already on hemodialysis; however, given the lack of data to support this, we do not recommend routine dialysis for patients not yet on dialysis or who are currently being treated with peritoneal dialysis. Decisions such as this should be made on a case by case basis after evaluating additional risk factors.
Acute renal failure and chronic kidney disease following liver transplantation
Authors: YALAVARTHY Rajesh , EDELSTEIN Charles L. , TEITELBAUM Isaac
Published: September 2007

Acute renal failure (ARF) and chronic kidney disease (CKD) are common complications after liver transplantation (LTx). The incidence of ARF post‐LTx varies between 48% and 94%; 8% to 17% of patients require renal replacement therapy (RRT). The most common cause of ARF early after LTx is ischemic acute tubular necrosis, followed later by cyclosporine toxicity and sepsis. Preoperative serum creatinine >1.5 mg/dL and early hepatic allograft dysfunction are risk factors for the occurrence of postoperative ARF. Of patients with ARF due to the hepatorenal syndrome, approximately two‐thirds will recover, although recovery may be delayed 3 months or longer after LTx. Mortality after LTx is affected modestly by the presence of ARF pretransplant (<2‐fold increase), but increases markedly (up to 8‐fold) in the face of ARF posttransplant. Mortality does not appear to be influenced by the mode of RRT used. The risk of CKD after LTx is approximately 18% at 5 years and increases to approximately 25% by 10 years after transplantation. Calcineurin inhibitor toxicity is the most common cause. Specific prognosticators for predicting CKD after LTx are presently lacking. The occurrence of CKD after LTx markedly impairs long‐term survival.
Hydration abnormalities in Nigerian patients on chronic hemodialysis
Authors: TZAMALOUKAS Antonios H. , ONIME Aideloje , AGABA Emmanuel I. , VANDERJAGT Dorothy J. , MA Irene , LOPEZ Andrea , TZAMALOUKAS Rolinda A. , GLEW Robert H.
Published: September 2007

The state of hydration affects the outcomes of chronic dialysis. Bioelectrical impedance analysis (BIA) provides estimates of body water (V), extracellular volume (ECFV), and fat‐free mass (FFM) that allow characterization of hydration. We compared single‐frequency BIA measurements before and after 14 hemodialysis sessions in 10 Nigerian patients (6 men, 4 women; 44±7 years old) with clinical evaluation (weight removed during dialysis, presence of edema) and with estimates of body water obtained by the Watson, Chertow, and Chumlea anthropometric formulas. Predialysis and postdialysis values of body water did not differ between BIA and anthropometric estimates. However, only the BIA estimate of the change in body water during dialysis (−0.8±2.9 L) did not differ from the corresponding change in body weight (−1.3±3.0 kg), while anthropometric estimates of the change in body water were significantly lower, approximately one‐third of the change in weight. Bioelectrical impedance analysis correctly detected the intradialytic change in body water content (the ratio V/Weight) in 79% of the cases, while anthropometric formula estimates of the same change were erroneous in each case. Compared with patients with clinical postdialysis euvolemia (n=7), those with postdialysis edema (n=5) had higher values of postdialysis BIA ratios V/FFM (0.77±0.01 vs. 0.72±0.03, p<0.01) and ECFV/V (0.53±0.02 vs. 0.47±0.06, p<0.05), respectively. Bioelectrical impedance analysis appeared to underestimate body water and extracellular volume in a patient with massive ascites and bilateral pleural effusions. Anthropometric formulas are not appropriate for evaluating the state of hydration in patients on chronic hemodialysis. In contrast, BIA provides estimates of hydration agreeing with clinical estimates in the same patients, although it tends to underestimate body water and extracellular volume in patients with large collections of fluid in central body cavities.