Whole-brain diffusion tensor imaging predicts 6-month functional outcome in acute intracerebral haemorrhage

INTRODUCTION

Small vessel disease (SVD) causes most spontaneous intracerebral haemorrhage (ICH) and is associated with widespread microstructural brain tissue disruption, which can be quantified via diffusion tensor imaging (DTI) metrics: mean diffusivity (MD) and fractional anisotropy (FA). Little is known about the impact of whole-brain microstructural alterations after SVD-related ICH. We aimed to investigate: (1) association between whole-brain DTI metrics and functional outcome after ICH; and (2) predictive ability of these metrics compared to the pre-existing ICH score.

METHODS

Sixty-eight patients (38.2% lobar) were retrospectively included. We assessed whole-brain DTI metrics (obtained within 5 days after ICH) in cortical and deep grey matter and white matter. We used univariable logistic regression to assess the associations between DTI and clinical-radiological variables and poor outcome (modified Rankin Scale > 2). We determined the optimal predictive variables (via LASSO estimation) in: model 1 (DTI variables only), model 2 (DTI plus non-DTI variables), model 3 (DTI plus ICH score). Optimism-adjusted C-statistics were calculated for each model and compared (likelihood ratio test) against the ICH score.

RESULTS

Deep grey matter MD (OR 1.04 [95% CI 1.01-1.07], p = 0.010) and white matter MD (OR 1.11 [95% CI 1.01-1.23], p = 0.044) were associated (univariate analysis) with poor outcome. Discrimination values for model 1 (0.67 [95% CI 0.52-0.83]), model 2 (0.71 [95% CI 0.57-0.85) and model 3 (0.66 [95% CI 0.52-0.82]) were all significantly higher than the ICH score (0.62 [95% CI 0.49-0.75]).

CONCLUSION

Our exploratory study suggests that whole-brain microstructural disruption measured by DTI is associated with poor 6-month functional outcome after SVD-related ICH. Whole-brain DTI metrics performed better at predicting recovery than the existing ICH score.

Acute corticospinal tract diffusion tensor imaging predicts 6-month functional outcome after intracerebral haemorrhage

INTRODUCTION

Diffusion tensor imaging (DTI) can assess the structural integrity of the corticospinal tract (CST) in vivo. We aimed to investigate whether CST DTI metrics after intracerebral haemorrhage (ICH) are associated with 6-month functional outcome and can improve the predictive performance of the existing ICH score.

METHODS

We retrospectively included 42 patients with DTI performed within 5 days after deep supratentorial spontaneous ICH. Ipsilesional-to-contralesional ratios were calculated for fractional anisotropy (rFA) and mean diffusivity (rMD) in the pontine segment (PS) of the CST. We determined the most predictive variables for poor 6-month functional outcome [modified Rankin Scale (mRS) > 2] using the least absolute shrinkage and selection operator (LASSO) method. We calculated discrimination using optimism-adjusted estimation of the area under the curve (AUC).

RESULTS

Patients with 6-month mRS > 2 had lower rFA (0.945 [± 0.139] vs 1.045 [± 0.130]; OR 0.004 [95% CI 0.00-0.77]; p =  0.04) and higher rMD (1.233 [± 0.418] vs 0.963 [± 0.211]; OR 22.5 [95% CI 1.46-519.68]; p = 0.02). Discrimination (AUC) values were: 0.76 (95% CI 0.61-0.91) for the ICH score, 0.71 (95% CI 0.54-0.89) for rFA, and 0.72 (95% CI 0.61-0.91) for rMD. Combined models with DTI and non-DTI variables offer an improvement in discrimination: for the best model, the AUC was 0.82 ([95% CI 0.68-0.95]; p = 0.15).

CONCLUSION

In our exploratory study, PS-CST rFA and rMD had comparable predictive ability to the ICH score for 6-month functional outcome. Adding DTI metrics to clinical-radiological scores might improve discrimination, but this needs to be investigated in larger studies.

Achieving change readiness for health service innovations

Continual innovation to address emerging population needs necessitates health service ongoing redesign and transformation worldwide. Recent examples include service transformations in response to Covid-19, many of which were led and managed by nurses. Ensuring change readiness is central to delivering these transformative changes yet has been identified as a central challenge impacting nurse leaders and managers. Recent evidence indicates that affective commitment to change among healthcare staff may be an important contributor to gaining support for change implementation but understudied in healthcare. A cross-sectional survey study was used to examine the association between affective commitment to change and change readiness among 30 healthcare staff across four projects in one state-wide health system in Australia. Our findings indicate that affective commitment to change; healthcare worker's emotional and personal perception of the value of the proposed change is independently associated with individual and collective change readiness. Given that achieving change readiness is a central goal of change management strategies, this pilot work provides valuable insight to inform the change management practices of nurse leaders and managers.

Is Gaining Affective Commitment the Missing Strategy for Successful Change Management in Healthcare?

Despite the requirement for continual change and development, change failure is omnipresent in health care, ranging from small technical errors within new systems, processes or technologies, through to breakdowns and large-scale disaster. Despite decades of research investment, consultancy and initiatives, creating a healthcare context that promotes clinician engagement with change remains elusive, with limited demonstrated progress. Affective commitment to change refers to commitment that is driven by a desire to support change based on its perceived benefits or value, as opposed to commitment that is based on a sense of obligation or the minimization of costs. Recent evidence from health-care contexts indicates that affective commitment to change drives change readiness more so than the individual’s self-efficacy for dealing with the change. Considering evidence regarding the effect of affective commitment to change on individual and collective change readiness among health-care staff, we may need to reorient our current strategies for managing change. We explore the opportunities to enhance affective commitment to change and, in turn, change readiness through adopting values-based approaches to designing and executing change proposals with clinicians and service users.

Distributed leadership in healthcare: leadership dyads and the promise of improved hospital outcomes

PURPOSE

This paper aims to extend the consideration of distributed leadership in health-care settings. Leadership is typically studied from the classical notion of the place of single leaders and continues to examine distributed leadership within small teams or horizontally. The purpose is to develop a practical understanding of how distributed leadership may occur vertically, between different layers of the health-care leadership hierarchy, examining its influence on health-care outcomes across two hospitals.

DESIGN/METHODOLOGY/APPROACH

Using semi-structured interviews, data were collected from 107 hospital employees (including executive leadership, clinical management and clinicians) from two hospitals in Australia and the USA. Using thematic content analysis, an iterative process was adopted characterized by alternating between social identity and distributed leadership literature and empirical themes to answer the question of how the practice of distributed leadership influences performance outcomes in hospitals?

FINDINGS

The perceived social identities of leadership groups shaped communication and performance both positively and negatively. In one hospital a moderating structure emerged as a leadership dyad, where leadership was distributed vertically between hospital hierarchal layers, observed to overcome communication limitations. Findings suggest dyad creation is an effective mechanism to overcome hospital hierarchy-based communication issues and ameliorate health-care outcomes.

ORIGINALITY/VALUE

The study demonstrates how current leadership development practices that focus on leadership relational and social competencies can benefit from a structural approach to include leadership dyads that can foster these same competencies. This approach could help develop future hospital leaders and in doing so, improve hospital outcomes.

MRI-related anxiety can induce slow BOLD oscillations coupled with cardiac oscillations

OBJECTIVE

Although about 1-2% of MRI examinations must be aborted due to anxiety, there is little research on how MRI-related anxiety affects BOLD signals in resting states.

METHODS

We re-analyzed cardiac beat-to beat interval (RRI) and BOLD signals of 23 healthy fMRI participants in four resting states by calculation of phase-coupling in the 0.07-0.13 Hz band and determination of positive time delays (pTDs; RRI leading neural BOLD oscillations) and negative time delays (nTDs; RRI lagging behind vascular BOLD oscillations). State anxiety of each subject was assigned to either a low anxiety (LA) or a high anxiety (HA, with most participants exhibiting moderate anxiety symptoms) category based on the inside scanner assessed anxiety score.

RESULTS

Although anxiety strongly differed between HA and LA categories, no significant difference was found for nTDs. In contrast, pTDs indicating neural BOLD oscillations exhibited a significant cumulation in the high anxiety category.

CONCLUSIONS

Findings may suggest that vascular BOLD oscillations related to slow cerebral blood circulation are of about similar intensity during low/no and elevated anxiety. In contrast, neural BOLD oscillations, which might be associated with a central rhythm generating mechanism (pacemaker-like activity), appear to be significantly intensified during elevated anxiety.

SIGNIFICANCE

The study provides evidence that fMRI-related anxiety can activate a central rhythm generating mechanism very likely located in the brain stem, associated with slow neural BOLD oscillation.

CIP2A regulates MYC translation (via its 5'UTR) in colorectal cancer

BACKGROUND

Deregulated expression of MYC is a driver of colorectal carcinogenesis, suggesting that decreasing MYC expression may have significant therapeutic value. CIP2A is an oncogenic factor that regulates MYC expression. CIP2A is overexpressed in colorectal cancer (CRC), and its expression levels are an independent marker for long-term outcome of CRC. Previous studies suggested that CIP2A controls MYC protein expression on a post-transcriptional level.

METHODS

To determine the mechanism by which CIP2A regulates MYC in CRC, we dissected MYC translation and stability dependent on CIP2A in CRC cell lines.

RESULTS

Knockdown of CIP2A reduced MYC protein levels without influencing MYC stability in CRC cell lines. Interfering with proteasomal degradation of MYC by usage of FBXW7-deficient cells or treatment with the proteasome inhibitor MG132 did not rescue the effect of CIP2A depletion on MYC protein levels. Whereas CIP2A knockdown had marginal influence on global protein synthesis, we could demonstrate that, by using different reporter constructs and cells expressing MYC mRNA with or without flanking UTR, CIP2A regulates MYC translation. This interaction is mainly conducted by the MYC 5'UTR.

CONCLUSIONS

Thus, instead of targeting MYC protein stability as reported for other tissue types before, CIP2A specifically regulates MYC mRNA translation in CRC but has only slight effects on global mRNA translation. In conclusion, we propose as novel mechanism that CIP2A regulates MYC on a translational level rather than affecting MYC protein stability in CRC.

Managing Complex Healthcare Change: A Qualitative Exploration of Current Practice in New South Wales, Australia

PURPOSE

As the cost of healthcare continues to rise, healthcare organizations internationally are seeking long-term solutions to eradicate inefficiency, achieve value-based healthcare, and minimize hospital inpatient services. This requires transformational change in healthcare organizations, and associated change management and leadership capability at multiple levels. Despite the critical need for effective change leadership and management in healthcare, limited evidence exists that this currently occurs in addition to the capability and capacity for managing change in health systems.

METHODS

Semi-structured interviews were undertaken with 16 healthcare managers and leaders at a range of levels in nine healthcare organizations across the public health system of one Australian state (New South Wales), including metropolitan, regional and rural geographical areas. Thematic content analysis was undertaken with the emergent data.

RESULTS

Four key themes emerged from the data: 1) lack of adoption of frameworks and methods for change management for any scope or scale of change, 2) inadequate resources for delivering, managing and leading change, 3) insufficient leadership, capacity and capability in managing change, and 4) the need for support and culture that supports change at all levels of the system.

CONCLUSION

Ensuring dedicated resources for change and sufficient capacity and capability amongst health professionals and managers at every level in a health system are required for effective management of change. An enabling culture for change, supported by adequate education and training in change leadership and management are critical in order for the benefits of health service and system changes to be realised.

BRAINDEX: An Interactive, Knowledge-Based System Supporting Brain Death Diagnosis

BRAINDEX (Brain-Death Expert System) is an interactive, knowledge-based expert system offering support to physicians in decision making concerning brain death. The physician is given the possibility of communicating in almost natural language and, therefore, in terms with which he is familiar. This updated version of the system is implemented on an IBM-PC/AT with the expert system shell PC-PLUS and consists of about 430 rules. The determination of brain death is realized with backward chaining and for the optional coma-scaling a forward-chaining mechanism is used.

Ring-Closing Polycondensations

The role of cyclization in polycondensations is discussed for two different scenarios: thermodynamically-controlled polycondensation (TCPs) on the one hand and kinetically-controlled polycondensations (KCPs) on the other. The classical Carothers–Flory theory of step-growth polymerization does not include cyclization reactions. However, TCPs involve the formation of cycles via ‘back-biting degradation’, and when the ring–chain equilibrium is on the side of the cycles the main reaction products of the TCP will be cyclic oligomers. Two groups of examples are discussed: polycondensations of salicyclic acid derivatives (e.g. aspirin) and polycondensations of dibutyltin derivatives with long α-, ω-diols or dicarboxylic acids. Furthermore, various kinetically-controlled syntheses of polyesters and polyamides were studied and carefully optimized in the direction of high molecular weights. High fractions of cyclic oligomers and polymers were found by MALDI-TOF mass spectrometry, and their fractions increased with optimization of the process for molecular weight. These results disagree with the Carothers–Flory theory but agree with the theoretical background of the Ruggli–Ziegler dilution method (RZDM). When poly(ether-sulfone)s were prepared from 4,4′-difluorodiphenylsulfone and silylated bisphenol-A two different scenarios were found. With CsF as catalyst at a temperature of more than 145°C cyclic oligoethers were formed under thermodynamic control. When the polycondensation was promoted with K2CO3 in N-methylpyrolidone at ≤145°C the formation of cyclic oligoethers and polyethers occurred under kinetic control. A new mathematical formula is presented correlating the average degree of polymerization with the conversion and taking into account the competition between cyclization and propagation.

Establishing the Feasibility of Face Transplantation in Granulomatosis With Polyangiitis

Granulomatosis with polyangiitis (GPA; formerly Wegener's granulomatosis) is a rare vasculitis that commonly starts in the craniofacial region. We report a case that was masked by prior facial trauma and associated with pyoderma gangrenosum (PG). Disease progression and aggressive debridements led to severe facial tissue loss. The decision to perform a face transplant was controversial because of the risk of disease relapse on the facial allograft. We reviewed renal transplant outcomes in GPA for possible relevance. A PubMed search retrieved 29 studies. Patient and graft survival, relapse, morbidity, mortality, rejection and immunosuppression were assessed. Ten-year patient survival and graft survival were 84.4% and 72.6%, respectively. GPA relapse occurred in 31.5%, and upper airway/ocular relapse occurred in 17.8% (resolved in 76.9%). Mortality was 12.3%. Acute and chronic rejection rates were 14.9% and 6.8%, respectively. Traditional posttransplant immunosuppression was effective. Our review suggests that GPA renal transplant outcomes are comparable to general renal transplant cohorts. Furthermore, transplanted GPA patients exhibit lower disease relapse secondary to lifelong immunosuppression. This supported our decision to perform a face transplant in this patient, which has been successful up to the present time (1-year posttransplantation). Untreated GPA and PG are potential causes of worse surgical outcomes in the craniofacial region.

Time to Take Off the Theoretical Straightjacket and (Re-)Introduce Phenomenon-Driven Research

Recently, at an Academy of Management meeting workshop, reflecting on the field, Warner Burke asked “where are the new models and theories of change?” This provocative question has been pondered within organization studies and specifically on organization theory for several decades. And yet it persists. Borrowing this debate, in this essay we reverse the question to consider whether theory might be the problem in change research. Specifically, we argue that theory has become a (figurative) straightjacket. Far from advancing debate as significantly as has regularly been assumed, an obsession with theory and a narrow understanding of what constitutes a contribution could be hampering the development of knowledge about change. The criteria for publishing organizational research are increasingly focused on adding to specific and already existing theory. As a challenge to the restrictions that have become convention, we decode what this theoretical straightjacket looks like, and query why change researchers have willingly gone down this path, shutting down other promising opportunities. In response, we present phenomenon-driven research as a possible solution. It is time for change researchers to reclaim our heritage and take off the theoretical straightjacket.

[Transcranial cerebral oxymetry in interventional neuroradiology. Sources of error in interpretation of measurement data]

Transcranial cerebral oximetry is a non-invasive method to support the estimation of the balance in cerebral oxygen metabolism status during interventional neuroradiological procedures. The simple data acquisition can lead to errors by oversimplification in interpretation of the displayed data. To avoid fatal mistakes of the acquired data the complex interactions of the examined substrate with physiological and pathophysiological interactions have to be critically judged as well as the procedural approach and methodological limitations.

S-palmitoylation represents a novel mechanism regulating the mitochondrial targeting of BAX and initiation of apoptosis

The intrinsic pathway of apoptotic cell death is mainly mediated by the BCL-2-associated X (BAX) protein through permeabilization of the mitochondrial outer membrane (MOM) and the concomitant release of cytochrome c into the cytosol. In healthy, non-apoptotic cells, BAX is predominantly localized in the cytosol and exhibits a dynamic shuttle cycle between the cytosol and the mitochondria. Thus, the initial association with mitochondria represents a critical regulatory step enabling BAX to insert into MOMs, promoting the release of cytochrome c and ultimately resulting in apoptosis. However, the molecular mode of how BAX associates with MOMs and whether a cellular regulatory mechanism governs this process is poorly understood. Here we show that in both primary tissues and cultured cells, the association with MOMs and the proapoptotic action of BAX is controlled by its S-palmitoylation at Cys-126. A lack of BAX palmitoylation reduced BAX mitochondrial translocation, BAX oligomerization, caspase activity and apoptosis. Furthermore, ectopic expression of specific palmitoyl transferases in cultured healthy cells increases BAX S-palmitoylation and accelerates apoptosis, whereas malignant tumor cells show reduced BAX S-palmitoylation consistent with their reduced BAX-mediated proapoptotic activity. Our findings suggest that S-palmitoylation of BAX at Cys126 is a key regulatory process of BAX-mediated apoptosis.

Appraisal of long-term radiation trends in the environs of nuclear power plants – Examples from Switzerland

Annually since 1989, biannually since 1994 the sites of the Swiss nuclear facilities (4 power plant sites, a nuclear research institute and a waste storage facility) are surveyed flying the same survey lines by airborne gamma ray spectrometry. The equipment and the data processing software used for those surveys was built and developed at the Institute of Geophysics, ETH Zurich. For mapping the ground radiation around the nuclear facilities a pixel representation and a modified Spectrum Dose Index (SDI) method is used. In the search for long-term trends the local dose-rates are calculated first and in turn the net dose rates over the time span 1992–2010. So far no significant change in the radiation levels was detected over the last 18 years outside of the fenced sites of the nuclear facilities, except for the operation of an industrial radiation facility in 1995.

Experimental model of laryngotracheal stenosis in infants: effects of different high-frequency jet ventilation patterns on pulmonary parameters

BACKGROUND

Supraglottic high-frequency jet ventilation (HFJV) in laryngotracheal surgery in infants with modified jet laryngoscopes offers the surgeon an unimpaired operating field. However, supraglottic HFJV is associated with the development of high airway pressures, inadvertent positive end-expiratory pressure (PEEP) levels, and barotrauma.

METHODS

We investigated the total lung volumes (TLV) and tidal volume variations at peak inspiratory pressure levels (PIP) and at PEEP levels along with the pulmonary pressures (PIP and PEEP) during two conventional methods of supraglottic HFJV in an infant trachea-lung model without stenosis and with different degrees of stenosis.

RESULTS

With augmentation of the driving pressure in the experiment without stenosis, the TLV plus the pulmonary pressures increased. With narrowing of the stenosis, TLV reduced at PIP level and increased at PEEP level. Volume shifts were significantly higher during superimposed HFJV compared with monofrequent HFJV at equivalent stenosis diameter (P < 0.05) except for the setting with 0.3 bar driving pressure (P > 0.05). The pulmonary PIP was in none of the test series higher than 20 mbar, and the pulmonary PEEP did not exceed 14 mbar.

CONCLUSIONS

The results from our experimental model support the safe and effective clinical use of supraglottic HFJV in infants with tracheal stenosis. Moderate driving pressures provide acceptable pulmonary pressures in normal compliant lungs.

Pore formation kinetics in membranes, determined from the release of marker molecules out of liposomes or cells

We discuss the efflux of entrapped marker material from liposomes or cells through pores in the membrane, being monitored by the time course of a certain signal F (e.g., fluorescence emission). This is expressed in terms of an appropriate normalized function of time, the so-called efflux function E(t). Under conditions frequently encountered in practice the measured E(t) can be easily related to the forward rate of pore formation if the liposomes/cells are monodisperse in size. In the basic case of a time-independent rate law it turns out that E(t) must be single exponential. Deviations from such a simple functional behavior might be due to a fairly broad distribution of liposome/cell sizes and/or a more complicated pore formation mechanism. A relevant evaluation of original data is demonstrated making use of experimental results obtained with small unilamellar lipid vesicles where pores are induced by the antibiotic peptide alamethicin. This includes the application of a general method to eliminate the effect of a given liposome/cell size distribution.

Effects of ageing on postreceptoral short-wavelength gain control: transient tritanopia increases with age

We investigated the effect of ageing on the neural gain control in the short-wavelength opponent channel. In order to tackle specifically postreceptoral changes, we determined the effect of ageing on transient tritanopia, a paradoxical and transient reduction of short-wavelength sensitivity after the presentation of a long-wavelength adapting light. The results demonstrate an unexpected and significant increase of transient tritanopia with age, which cannot be explained by a general decline of short-wave sensitivity or the selective reduction of retinal illumination. Instead, our data imply that ageing affects also short-wavelength gain control at the site of chromatic opponency or beyond. Age-related changes of adaptation processes should therefore be considered an important factor influencing the visual performances of the elderly.

Search for long-term radiation trends in the environs of Swiss nuclear power plants

Annually since 1989, biannually since 1994 the sites of the Swiss nuclear facilities are surveyed flying the same survey lines by airborne gamma ray spectrometry. The equipment and the data processing software used for those surveys were built and developed at the Institute of Geophysics, ETH Zurich. For mapping the ground radiation around the nuclear facilities, a pixel representation and a modified spectrum dose index (SDI) method are used. In the search for long-term trends, the local dose rates are calculated first and in turn the net dose rates. So far, no change in the radiation levels was detected over the last 13 years outside of the fenced sites of the nuclear facilities and, especially, no artificial radioactivity was present that could not be explained by nuclear weapon tests or by the Chernobyl event.

Linear cooperative binding of large ligands involving mutual exclusion of different binding modes

A rigorous treatment is given for mutually exclusive multiple mode cooperative binding on a linear structure of equivalent binding "contacts". This will be of special interest with regard to larger ligands implicating the possibility that there are different kinds of binding interactions with more than one monomeric sub unit of a linear biopolymer. Quantitative evaluation of binding properties is shown to be essentially based on calculating the largest root of an algebraic equation. The whole procedure can be practically executed by means of a fairly simple computer program. Various typical examples comprising only two modes are discussed in more detail. For some nucleotide-polylysine systems definite binding parameters have been determined from pertinent experimental data.