Characteristics and outcomes of COVID-19 patients with and without asthma from the United States, South Korea, and Europe

Objective: Large international comparisons describing the clinical characteristics of patients with COVID-19 are limited. The aim of the study was to perform a large-scale descriptive characterization of COVID-19 patients with asthma.Methods: We included nine databases contributing data from January to June 2020 from the US, South Korea (KR), Spain, UK and the Netherlands. We defined two cohorts of COVID-19 patients ('diagnosed' and 'hospitalized') based on COVID-19 disease codes. We followed patients from COVID-19 index date to 30 days or death. We performed descriptive analysis and reported the frequency of characteristics and outcomes in people with asthma defined by codes and prescriptions.Results: The diagnosed and hospitalized cohorts contained 666,933 and 159,552 COVID-19 patients respectively. Exacerbation in people with asthma was recorded in 1.6-8.6% of patients at presentation. Asthma prevalence ranged from 6.2% (95% CI 5.7-6.8) to 18.5% (95% CI 18.2-18.8) in the diagnosed cohort and 5.2% (95% CI 4.0-6.8) to 20.5% (95% CI 18.6-22.6) in the hospitalized cohort. Asthma patients with COVID-19 had high prevalence of comorbidity including hypertension, heart disease, diabetes and obesity. Mortality ranged from 2.1% (95% CI 1.8-2.4) to 16.9% (95% CI 13.8-20.5) and similar or lower compared to COVID-19 patients without asthma. Acute respiratory distress syndrome occurred in 15-30% of hospitalized COVID-19 asthma patients.Conclusion: The prevalence of asthma among COVID-19 patients varies internationally. Asthma patients with COVID-19 have high comorbidity. The prevalence of asthma exacerbation at presentation was low. Whilst mortality was similar among COVID-19 patients with and without asthma, this could be confounded by differences in clinical characteristics. Further research could help identify high-risk asthma patients.[Box: see text]Supplemental data for this article is available online at https://doi.org/10.1080/02770903.2021.2025392 .

Induction of a NOTCH3 Lehman syndrome mutation in osteocytes causes osteopenia in male C57BL/6J mice

Lateral Meningocele or Lehman Syndrome (LMS) is associated with NOTCH3 mutations causing deletions of the PEST domain and a gain-of-NOTCH3 function. We demonstrated that Notch3em1Ecan mice harboring Notch3 mutations analogous to those found in LMS are osteopenic because of enhanced bone resorption. To determine the contribution of specific cell lineages to the phenotype, we created a conditional-by-inversion (Notch3COIN) model termed Notch3em2Ecan in which Cre recombination generates a Notch3INV allele expressing a NOTCH3 mutant lacking the PEST domain. Germ line Notch3COIN inversion caused osteopenia and phenocopied the Notch3em1Ecan mutant, validating the model. To induce the mutation in osteocytes, smooth muscle and endothelial cells, Notch3COIN mice were bred with mice expressing Cre from the Dmp1, Sm22a and Cdh5 promoters, respectively, creating experimental mice harboring Notch3INV alleles in Cre-expressing cells and control littermates harboring Notch3COIN alleles. Notch3COIN inversion in osteocytes led to femoral and vertebral cancellous bone osteopenia, whereas Notch3COIN inversion in mural Sm22a or endothelial Cdh5-expressing cells did not result in a skeletal phenotype. In conclusion, introduction of the LMS mutation in osteocytes but not in vascular cells causes osteopenia and phenocopies Notch3em1Ecan global mutant mice.

Role of nuclear factor of activated T cells in chondrogenesis osteogenesis and osteochondroma formation

PURPOSE

Nuclear factor of activated T cells (NFATc) are transcription factors that play a function in the immune response and in osteoclast differentiation. In the present work, we define the function of NFATc2 in chondrogenic and osteogenic cells.

METHODS

Nfatc2^loxP/loxP and Nfatc1^loxP/loxP;Nfatc2^loxP/loxP conditional mice were crossed with Prx1-Cre transgenics to inactivate Nfatc2 singly and with Nfatc1. Femurs and vertebrae were examined by microcomputed tomography (µCT) X-Ray images and histology and analyzed for the presence of osteochondromas.

RESULTS

µCT demonstrated that Prx1-Cre;Nfatc2^∆/∆ female mice had transient osteopenia and male mice did not have a cancellous or a cortical bone phenotype when compared to control mice. In contrast, the dual inactivation of Nfatc1 and Nfatc2 in Prx1-expressing cells resulted in cancellous osteopenia and small bones at 1 month of age in both sexes. Nfatc1;Nfatc2 deleted mice exhibited a ~ 50% decrease in bone volume and connectivity. Total bone area, periosteal and endocortical bone perimeters and femoral length were reduced indicating smaller bones. As the mice matured, the shortening of the femoral length persisted, but the osteopenic phenotype resolved and cancellous femoral bone of 4-month-old Nfatc1;Nfatc2 deleted mice was not different from controls although male mice had vertebral osteopenia. In addition, Nfatc1;Nfatc2 deleted mice displayed distortion of the distal metaphysis and, as they matured, the articular presence of mineralized tumors with the appearance of osteochondromas.

CONCLUSION

Our studies reveal that NFATc1 and NFATc2 are necessary for optimal bone homeostasis and the suppression of osteochondroma formation.

A process to deduplicate individuals for regional chronic disease prevalence estimates using a distributed data network of electronic health records

Introduction

Learning health systems can help estimate chronic disease prevalence through distributed data networks (DDNs). Concerns remain about bias introduced to DDN prevalence estimates when individuals seeking care across systems are counted multiple times. This paper describes a process to deduplicate individuals for DDN prevalence estimates.

Methods

We operationalized a two‐step deduplication process, leveraging health information exchange (HIE)‐assigned network identifiers, within the Colorado Health Observation Regional Data Service (CHORDS) DDN. We generated prevalence estimates for type 1 and type 2 diabetes among pediatric patients (0‐17 years) with at least one 2017 encounter in one of two geographically‐proximate DDN partners. We assessed the extent of cross‐system duplication and its effect on prevalence estimates.

Results

We identified 218 437 unique pediatric patients seen across systems during 2017, including 7628 (3.5%) seen in both. We found no measurable difference in prevalence after deduplication. The number of cases we identified differed slightly by data reconciliation strategy. Concordance of linked patients' demographic attributes varied by attribute.

Conclusions

We implemented an HIE‐dependent, extensible process that deduplicates individuals for less biased prevalence estimates in a DDN. Our null pilot findings have limited generalizability. Overlap was small and likely insufficient to influence prevalence estimates. Other factors, including the number and size of partners, the matching algorithm, and the electronic phenotype may influence the degree of deduplication bias. Additional use cases may help improve understanding of duplication bias and reveal other principles and insights. This study informed how DDNs could support learning health systems' response to public health challenges and improve regional health.

Assessment of Allergic and Anaphylactic Reactions to mRNA COVID-19 Vaccines With Confirmatory Testing in a US Regional Health System

IMPORTANCE

As of May 2021, more than 32 million cases of COVID-19 have been confirmed in the United States, resulting in more than 615 000 deaths. Anaphylactic reactions associated with the Food and Drug Administration (FDA)-authorized mRNA COVID-19 vaccines have been reported.

OBJECTIVE

To characterize the immunologic mechanisms underlying allergic reactions to these vaccines.

DESIGN, SETTING, AND PARTICIPANTS

This case series included 22 patients with suspected allergic reactions to mRNA COVID-19 vaccines between December 18, 2020, and January 27, 2021, at a large regional health care network. Participants were individuals who received at least 1 of the following International Statistical Classification of Diseases and Related Health Problems, Tenth Revision anaphylaxis codes: T78.2XXA, T80.52XA, T78.2XXD, or E949.9, with documentation of COVID-19 vaccination. Suspected allergy cases were identified and invited for follow-up allergy testing.

EXPOSURES

FDA-authorized mRNA COVID-19 vaccines.

MAIN OUTCOMES AND MEASURES

Allergic reactions were graded using standard definitions, including Brighton criteria. Skin prick testing was conducted to polyethylene glycol (PEG) and polysorbate 80 (P80). Histamine (1 mg/mL) and filtered saline (negative control) were used for internal validation. Basophil activation testing after stimulation for 30 minutes at 37 °C was also conducted. Concentrations of immunoglobulin (Ig) G and IgE antibodies to PEG were obtained to determine possible mechanisms.

RESULTS

Of 22 patients (20 [91%] women; mean [SD] age, 40.9 [10.3] years; 15 [68%] with clinical allergy history), 17 (77%) met Brighton anaphylaxis criteria. All reactions fully resolved. Of patients who underwent skin prick tests, 0 of 11 tested positive to PEG, 0 of 11 tested positive to P80, and 1 of 10 (10%) tested positive to the same brand of mRNA vaccine used to vaccinate that individual. Among these same participants, 10 of 11 (91%) had positive basophil activation test results to PEG and 11 of 11 (100%) had positive basophil activation test results to their administered mRNA vaccine. No PEG IgE was detected; instead, PEG IgG was found in tested individuals who had an allergy to the vaccine.

CONCLUSIONS AND RELEVANCE

Based on this case series, women and those with a history of allergic reactions appear at have an elevated risk of mRNA vaccine allergy. Immunological testing suggests non-IgE-mediated immune responses to PEG may be responsible in most individuals.

Comparative transcriptome analysis of inner blood-retinal barrier and blood-brain barrier in rats

Although retinal microvessels (RMVs) and brain microvessels (BMVs) are closely related in their developmental and share similar blood-neural barriers, studies have reported markedly different responses to stressors such as diabetes. Therefore, we hypothesized that RMVs and BMVs will display substantial differences in gene expression levels even though they are of the same embryological origin. In this study, both RMVs and BMVs were mechanically isolated from rats. Full retinal and brain tissue samples (RT, BT) were collected for comparisons. Total RNA extracted from these four groups were processed on Affymetrix rat 2.0 microarray Chips. The transcriptional profiles of these tissues were then analyzed. In the present paper we looked at differentially expressed genes (DEGs) in RMVs (against RT) and BMVs (against BT) using a rather conservative threshold value of ≥  ± twofold change and a false discovery rate corrected for multiple comparisons (p < 0.05). In RMVs a total of 1559 DEGs were found, of which 1004 genes were higher expressed in RMVs than in RT. Moreover, 4244 DEGs between BMVs and BT were identified, of which 1956 genes were ≥ twofold enriched in BMVs. Using these DEGs, we comprehensively analyzed the actual expression levels and highlighted their involvement in critical functional structures in RMVs and BMVs, such as junctional complex, transporters and signaling pathways. Our work provides for the first time the transcriptional profiles of rat RMVs and BMVs. These results may help to understand why retina and brain microvasculature show different susceptibilities to stressors, and they might even provide new insight for pharmacological interventions.

The prevalence of COVID-19 in healthcare personnel in an adult and pediatric academic medical center

BACKGROUND

It is vital to know which healthcare personnel (HCP) have a higher chance of testing positive for severe acute respiratory syndrome coronavirus 2 (COVID-19).

METHODS

A retrospective analysis was conducted at Stanford Children's Health (SCH) and Stanford Health Care (SHC) in Stanford, California. Analysis included all HCP, employed by SCH or SHC, who had a COVID-19 reverse transcriptase polymerase chain reaction (RT-PCR) test resulted by the SHC Laboratory, between March 1, 2020 and June 15, 2020. The primary outcome was the RT-PCR percent positivity and prevalence of COVID-19 for HCP and these were compared across roles.

RESULTS

SCH and SHC had 24,081 active employees, of which 142 had at least 1 positive COVID-19 test. The overall HCP prevalence of COVID-19 was 0.59% and percent positivity was 1.84%. Patient facing HCPs had a significantly higher prevalence (0.66% vs 0.43%; P = .0331) and percent positivity (1.95% vs 1.43%; P = .0396) than nonpatient facing employees, respectively. Percent positivity was higher in food service workers (9.15%), and environmental services (5.96%) compared to clinicians (1.93%; P < .0001) and nurses (1.46%; P < .0001), respectively.

DISCUSSION AND CONCLUSION

HCP in patient-facing roles and in support roles had a greater chance of being positive of COVID-19.

Unraveling COVID-19: a large-scale characterization of 4.5 million COVID-19 cases using CHARYBDIS

Background: Routinely collected real world data (RWD) have great utility in aiding the novel coronavirus disease (COVID-19) pandemic response [1,2]. Here we present the international Observational Health Data Sciences and Informatics (OHDSI) [3] Characterizing Health Associated Risks, and Your Baseline Disease In SARS-COV-2 (CHARYBDIS) framework for standardisation and analysis of COVID-19 RWD. Methods: We conducted a descriptive cohort study using a federated network of data partners in the United States, Europe (the Netherlands, Spain, the UK, Germany, France and Italy) and Asia (South Korea and China). The study protocol and analytical package were released on 11 th June 2020 and are iteratively updated via GitHub [4]. Findings: We identified three non-mutually exclusive cohorts of 4,537,153 individuals with a clinical COVID-19 diagnosis or positive test, 886,193 hospitalized with COVID-19 , and 113,627 hospitalized with COVID-19 requiring intensive services . All comorbidities, symptoms, medications, and outcomes are described by cohort in aggregate counts, and are available in an interactive website: https://data.ohdsi.org/Covid19CharacterizationCharybdis/. Interpretation: CHARYBDIS findings provide benchmarks that contribute to our understanding of COVID-19 progression, management and evolution over time. This can enable timely assessment of real-world outcomes of preventative and therapeutic options as they are introduced in clinical practice.

Navigating the Covid-19 Pandemic by Caring for Our Health Care Workforce as They Care for Our Patients

Leaders at Stanford Medicine, located in one of the first U.S. communities to be affected by Covid-19, quickly realized that they were not prepared to meet the escalating needs of their clinical and operational workforce. The pandemic would require existing care-delivery structures across the academic medical system to be expanded and aligned to prioritize workforce protection. Leaders identified an approach driven by connection, collaboration, and caring. They created specialized teams to develop a systemwide Occupational Health service with practices and procedures to assess health care workers and begin robust Covid-19 polymerase chain reaction testing; to centralize operations to maximize utilization of essential clinical and nonclinical staffing resources; to make visible and address psychological safety concerns and basic needs for faculty and staff; to aggressively address personal protective equipment supply chain issues and effectively assess infection risk; and to plan for a safe return of elective procedures and visits.

[The use of sunglasses during leisure time and work : Lack of prevention of sun-induced eye damage]

OBJECTIVE

This study aimed at collecting representative national data on the use of sunglasses on sunny summer days during leisure time or work as well as identifying population and professional groups with a pronounced lack of preventive measures to avoid sun-induced eye damage.

MATERIAL AND METHODS

Within the representative National Cancer Aid Monitoring, data on the use of sunglasses during leisure time was assessed among 3000 individuals aged 14-45 years in 2015, as well as on the use during outdoor work among 485 workers aged 14-45 years in 2016. Associations between the use of sunglasses and sociodemographic characteristics were assessed with the χ²-test. Additionally, descriptive and bivariate methods were used to assess connections between the use of sunglasses at work and each professional group.

RESULTS

While more than half of the general population normally or often wear sunglasses on a sunny summer day, only one third of outdoor workers do so. While approximately every seventh individual surveyed never wears sunglasses during leisure time, among outdoor workers it is one out of three. The use during leisure time increases with age.

DISCUSSION

Use of sunglasses during work could be supported by targeted information on UV-induced eye damage by ophthalmologists and company physicians with additional support from accident insurances and employers. Concerning preventive measures occupational groups such as landscapers, farmers and bricklayers who are strongly exposed to sunlight but rarely wear sunglasses are important groups.

Efficacy of metacognitive training for patients with borderline personality disorder: Preliminary results

'Metacognitive training for borderline personality disorder' (B-MCT) represents a complementary group intervention. It aims at raising awareness for cognitive biases that may play an important role in the development and maintenance of borderline symptomatology. For the present study, we evaluated the effectiveness of this new approach against a control condition. Seventy-four inpatients with borderline personality disorder (BPD) were randomly assigned to metacognitive training for BPD or progressive muscle relaxation training as an add-on intervention to treatment as usual. Severity of symptomatology was assessed at baseline, four weeks after beginning and six months after completion of the intervention. The per-protocol and intention-to-treat analyses revealed that patients in the metacognitive training group showed significantly greater reductions on the primary outcome (Borderline Symptom List-23) after six months. Progressive muscle relaxation was superior in alleviating depressive symptoms (secondary outcome: Beck Depression Inventory) at the long-term follow-up. Findings provide preliminary evidence that metacognitive training for BPD yields surplus effects to standard treatment.

Der aktuelle Stellenwert von PUVA- und UVA-1-Therapie als sichere und wirksame Therapieoptionen bei zahlreichen Hautkrankheiten

Sonnenlicht wurde von vielen Kulturvölkern schon vor langer Zeit zu gesundheitlichen Zwecken genutzt. Schon damals wurden photosensibilisierende Pflanzenbestandteile topisch oder systemisch angewendet, bevor die Haut dem Sonnenlicht ausgesetzt wurde. Nach Jahrzehnten der erfolgreichen Anwendung haben sich PUVA- und UVA-1-Phototherapie heute als sichere und effektive Standardoptionen zur Behandlung zahlreicher Dermatosen etabliert, wobei die UVA-1-Therapie in der Regel nur von spezialisierten Zentren angeboten wird. Unter Berücksichtigung internationaler Empfehlungen soll zur Minimierung des Langzeitrisikos die Anzahl der PUVA-Behandlungen in der Regel 200 – 250 nicht übersteigen. Bei einer Überschreitung dieser Zahl ist die Indikation für weitere PUVA-Behandlungen besonders kritisch abzuwägen. Daneben sind dann auch engmaschige Hautkrebsvorsorgeuntersuchungen erforderlich. Um eine noch bessere Risiko-Nutzen-Abwägung sowie Anwendungssicherheit für die Patienten zu gewährleisten, bedarf es weiterer Langzeit-Ergebnisse.

Reproductive activity triggers accelerated male mortality and decreases lifespan: genetic and gene expression determinants in Drosophila

Reproduction and aging evolved to be intimately associated. Experimental selection for early-life reproduction drives the evolution of decreased longevity in Drosophila whereas experimental selection for increased longevity leads to changes in reproduction. Although life history theory offers hypotheses to explain these relationships, the genetic architecture and molecular mechanisms underlying reproduction-longevity associations remain a matter of debate. Here we show that mating triggers accelerated mortality in males and identify hundreds of genes that are modulated upon mating in the fruit fly Drosophila melanogaster. Interrogation of genome-wide gene expression in virgin and recently mated males revealed coherent responses, with biological processes that are upregulated (testis-specific gene expression) or downregulated (metabolism and mitochondria-related functions) upon mating. Furthermore, using a panel of genotypes from the Drosophila Synthetic Population Resource (DSPR) as a source of naturally occurring genetic perturbation, we uncover abundant variation in longevity and reproduction-induced mortality among genotypes. Genotypes displayed more than fourfold variation in longevity and reproduction-induced mortality that can be traced to variation in specific segments of the genome. The data reveal individual variation in sensitivity to reproduction and physiological processes that are enhanced and suppressed upon mating. These results raise the prospect that variation in longevity and age-related traits could be traced to processes that coordinate germline and somatic function.

A Harmonized Data Quality Assessment Terminology and Framework for the Secondary Use of Electronic Health Record Data

Objective:

Harmonized data quality (DQ) assessment terms, methods, and reporting practices can establish a common understanding of the strengths and limitations of electronic health record (EHR) data for operational analytics, quality improvement, and research. Existing published DQ terms were harmonized to a comprehensive unified terminology with definitions and examples and organized into a conceptual framework to support a common approach to defining whether EHR data is ‘fit’ for specific uses.

Materials and Methods:

DQ publications, informatics and analytics experts, managers of established DQ programs, and operational manuals from several mature EHR-based research networks were reviewed to identify potential DQ terms and categories. Two face-to-face stakeholder meetings were used to vet an initial set of DQ terms and definitions that were grouped into an overall conceptual framework. Feedback received from data producers and users was used to construct a draft set of harmonized DQ terms and categories. Multiple rounds of iterative refinement resulted in a set of terms and organizing framework consisting of DQ categories, subcategories, terms, definitions, and examples. The harmonized terminology and logical framework’s inclusiveness was evaluated against ten published DQ terminologies.

Results:

Existing DQ terms were harmonized and organized into a framework by defining three DQ categories: (1) Conformance (2) Completeness and (3) Plausibility and two DQ assessment contexts: (1) Verification and (2) Validation. Conformance and Plausibility categories were further divided into subcategories. Each category and subcategory was defined with respect to whether the data may be verified with organizational data, or validated against an accepted gold standard, depending on proposed context and uses. The coverage of the harmonized DQ terminology was validated by successfully aligning to multiple published DQ terminologies.

Discussion:

Existing DQ concepts, community input, and expert review informed the development of a distinct set of terms, organized into categories and subcategories. The resulting DQ terms successfully encompassed a wide range of disparate DQ terminologies. Operational definitions were developed to provide guidance for implementing DQ assessment procedures. The resulting structure is an inclusive DQ framework for standardizing DQ assessment and reporting. While our analysis focused on the DQ issues often found in EHR data, the new terminology may be applicable to a wide range of electronic health data such as administrative, research, and patient-reported data.

Conclusion:

A consistent, common DQ terminology, organized into a logical framework, is an initial step in enabling data owners and users, patients, and policy makers to evaluate and communicate data quality findings in a well-defined manner with a shared vocabulary. Future work will leverage the framework and terminology to develop reusable data quality assessment and reporting methods.

Kaiser Permanente's performance improvement system, Part 4: Creating a learning organization

BACKGROUND

In 2006, recognizing variations in performance in quality, safety, service, and efficiency, Kaiser Permanente leaders initiated the development of a performance improvement (PI) system. Kaiser Permanente has implemented a strategy for creating the systemic capacity for continuous improvement that characterizes a learning organization. Six "building blocks" were identified to enable Kaiser Permanente to make the transition to becoming a learning organization: real-time sharing of meaningful performance data; formal training in problem-solving methodology; workforce engagement and informal knowledge sharing; leadership structures, beliefs, and behaviors; internal and external benchmarking; and technical knowledge sharing. Putting each building block into place required multiple complex strategies combining top-down and bottom-up approaches.

SUCCESSES AND CHALLENGES

Although the strategies have largely been successful, challenges remain. The demand for real-time meaningful performance data can conflict with prioritized changes to health information systems. It is an ongoing challenge to teach PI, change management, innovation, and project management to all managers and staff without consuming too much training time. Challenges with workforce engagement include low initial use of tools intended to disseminate information through virtual social networking. Uptake of knowledge-sharing technologies is still primarily by innovators and early adopters. Leaders adopt new behaviors at varying speeds and have a range of abilities to foster an environment that is psychologically safe and stimulates inquiry.

CONCLUSIONS

A learning organization has the capability to improve, and it develops structures and processes that facilitate the acquisition and sharing of knowledge.

Attributional "Tunnel Vision" in Patients With Borderline Personality Disorder

We aimed to examine the profile of interpersonal attributions in BPD. We hypothesized that patients show more mono-causal and internal attributions than healthy controls. A revised version of the Internal, Personal, Situational and Attributions Questionnaire was assessed in 30 BPD patients and 30 healthy controls. BPD patients and controls differed significantly in their attributional pattern. Patients displayed more mono-causal inferences, that is, they had difficulties considering alternative explanatory factors. For negative events, patients made more internal attributions compared to healthy controls. We concluded that mono-causal "trapped" thinking might contribute to (interpersonal) problems in BPD patients by fostering impulsive consequential behaviors, for example, harming one's self or others. A self-blaming tendency likely promotes depressive symptoms and low self-esteem.

Preliminary Results on Acceptance, Feasibility, and Subjective Efficacy of the Add-On Group Intervention Metacognitive Training for Borderline Patients

OBJECTIVE

The add-on intervention "metacognitive training for borderline patients (B-MCT)" targets cognitive biases in patients with borderline personality disorder (BPD). We aimed to evaluate acceptance, feasibility, and subjective use of this group intervention.

METHODS

Forty-eight inpatients with BPD were randomly assigned to 8 sessions of B-MCT versus an active control intervention (progressive muscle relaxation). Subjective use was assessed after 4 weeks.

RESULTS

B-MCT yielded significantly superior scores relative to the control group on several parameters, for example, use, fun, recommendation, and subjective improvements in symptomatology and cognitive abilities (e.g., perspective taking).

CONCLUSIONS

The trial provides preliminary evidence for the acceptance and feasibility of metacognitive training in BPD. However, randomized controlled trials with larger samples and symptomatic outcomes are needed to investigate the specific impact of B-MCT on psychopathology and cognition.

Trichotillomania and emotion regulation: is symptom severity related to alexithymia?

Previous research on trichotillomania (TTM) has demonstrated an emotion regulation function of hair pulling behavior. One condition that can impede the regulation of emotions is alexithymia. The present study aimed to explore the relationship between the degree of alexithymia and the severity of hair pulling behavior in individuals with TTM. Multiple strategies were used to recruit a sample of 105 participants via the internet. All participants were diagnosed with TTM by an experienced clinician via a subsequent phone-interview. Multiple linear regression analysis was performed to test the potential predictive value of the different facets of alexithymia (20-item Toronto Alexithymia Scale) on the severity of TTM (Massachusetts General Hospital Hair-Pulling Scale). Both the difficulty in identifying feelings (DIF) facet of alexithymia (p=0.045) and depression (p=0.049) were significant predictors of the severity of TTM. In conclusion, alexithymia seems to play a role in hair pulling behavior in individuals with TTM. However, the significant association was small in terms of the overall variance explained, thus warranting further research. If replicated in prospective studies, then these results indicate that therapeutic approaches aimed at supporting patients in recognizing and differentiating feelings might be useful for the treatment of TTM.

False memories and memory confidence in borderline patients

BACKGROUND AND OBJECTIVES

Mixed results have been obtained regarding memory in patients with borderline personality disorder (BPD). Prior reports and anecdotal evidence suggests that patients with BPD are prone to false memories but this assumption has to been put to firm empirical test, yet.

METHODS

Memory accuracy and confidence was assessed in 20 BPD patients and 22 healthy controls using a visual variant of the false memory (Deese-Roediger-McDermott) paradigm which involved a negative and a positive-valenced picture.

RESULTS

Groups did not differ regarding veridical item recognition. Importantly, patients did not display more false memories than controls. At trend level, borderline patients rated more items as new with high confidence compared to healthy controls.

CONCLUSIONS

The results tentatively suggest that borderline patients show uncompromised visual memory functions and display no increased susceptibility for distorted memories.

Orthopaedic Disorders in Myotonic Dystrophy Type 1: descriptive clinical study of 21 patients

Background

Myotonic Dystrophy Type 1 (DM1) is the most common form of hereditary myopathy presenting in adults. This autosomal-dominant systemic disorder is caused by a CTG repeat, demonstrating various symptoms. A mild, classic and congenital form can be distinguished. Often the quality of life is reduced by orthopaedic problems, such as muscle weakness, contractures, foot or spinal deformities, which limit patients’ mobility.

The aim of our study was to gather information about the orthopaedic impairments in patients with DM1 in order to improve the medical care of patients, affected by this rare disease.

Methods

A retrospective clinical study was carried out including 21 patients (11 male and 10 female), all diagnosed with DM1 by genetic testing. All patients were seen during our special consultations for neuromuscular diseases, during which patients were interviewed and examined. We also reviewed surgery reports of our hospitalized patients.

Results

We observed several orthopaedic impairments: spinal deformities (scoliosis, hyperkyphosis, rigid spine), contractures (of the upper extremities and the lower extremities), foot deformities (equinus deformity, club foot, pes cavus, pes planovalgus, pes cavovarus, claw toes) and fractures.

Five patients were affected by pulmonary diseases (obstructive airway diseases, restrictive lung dysfunctions). Twelve patients were affected by cardiac disorders (congenital heart defects, valvular heart defects, conduction disturbances, pulmonary hypertension, cardiomyopathy).

Our patients received conservative therapy (physiotherapy, logopaedic therapy, ergotherapy) and we prescribed orthopaedic technical devices (orthopaedic custom-made shoes, insoles, lower and upper leg orthoses, wheelchair, Rehab Buggy). We performed surgery for spinal and foot deformities: the scoliosis of one patient was stabilized and seven patients underwent surgery for correction of foot deformities.

Conclusions

An orthopaedic involvement in DM1 patients should not be underestimated. The most common orthopaedic impairments are contractures, foot deformities and spinal deformities. Contractures are typically located distally in the lower extremities, but can also occur in the hip or shoulder joints. Foot deformities could be treated with orthopaedic custom-made shoes, orthoses or insoles. Surgery is indicated for severe foot deformities or contractures.

Normal mind-reading capacity but higher response confidence in borderline personality disorder patients

AIM

Borderline personality disorder (BPD) is characterized by a pattern of instability in interpersonal relationships. Therefore, the investigation of social cognition is of compelling interest for the understanding of BPD. One important aspect of social cognition is theory of mind (ToM), which describes the ability to understand others' mental states, such as beliefs, desires and intentions. The aim of the present study was to further investigate ToM in BPD patients.

METHODS

The Reading the Mind in the Eyes Test was assessed in 31 BPD patients and 27 healthy controls. In addition, the test was complemented by a response confidence rating.

RESULTS

BPD patients and healthy controls did not differ in their mind-reading ability with respect to accuracy, but patients were significantly more often highly confident in their decisions than controls.

CONCLUSIONS

Overconfidence might contribute to the severe difficulties in interpersonal relationships often observed in BPD patients.

Larger than life: overestimation of object size is moderated by personal relevance in obsessive-compulsive disorder

BACKGROUND AND OBJECTIVES

Along with other cognitive biases overestimation of threat (OET) has been implicated in the pathogenesis of obsessive-compulsive disorder (OCD). The present study investigated whether OET would not only manifest in cognitive distortions but, also in overestimations of the object size of disorder-related visual objects.

METHODS

A total of 65 participants with OCD and 55 healthy controls who were recruited via OCD online forums underwent an incidental learning paradigm consisting of two blocks. In Block 1, participants were asked to rate the valence and the personal relevance for individual OCD concerns of 40 pictures which varied in size. Differences in size, however, were not explicitly communicated to the participants. Stimuli were selected from four categories: 1. neutral, 2. fear-related but OCD-unrelated, 3. washing (OCD-related), and 4. checking (OCD-related). In Block 2, participants were asked to recollect the original size of each stimulus (depicted as a small thumbnail) on a seven point scale.

RESULTS

Whereas few group differences emerged for pre-defined OCD items, OCD-relevant items (individual judgments) were judged as significantly larger by patients with OCD relative to controls. The opposite pattern emerged for neutral items.

LIMITATIONS

The sample was recruited via online forums and had probable but not externally validated diagnoses of OCD. No psychiatric control group was recruited.

CONCLUSIONS

The present study indicates that OET may extend to neuropsychological tasks. Further research is needed to pinpoint whether OET occurs at the level of encoding suggesting a perceptual bias and/or occurs at the level of retrieval suggesting a memory bias.

Psychotic-like cognitive biases in borderline personality disorder

Whereas a large body of research has linked borderline personality disorder (BPD) with affective rather than psychotic disorders, BPD patients frequently display psychotic and psychosis-prone symptoms, respectively. The present study investigated whether cognitive biases implicated in the pathogenesis of psychotic symptoms, especially delusions, are also evident in BPD. A total of 20 patients diagnosed with BPD and 20 healthy controls were administered tasks measuring neuropsychological deficits (psychomotor speed, executive functioning) and cognitive biases (e.g., one-sided reasoning, jumping to conclusions, problems with intentionalizing). Whereas BPD patients performed similar to controls on standard neuropsychological tests, they showed markedly increased scores on four out of five subscales of the Cognitive Biases Questionnaire for Psychosis (CBQp) and displayed a one-sided attributional style on the revised Internal, Personal and Situational Attributions Questionnaire (IPSAQ-R) with a marked tendency to attribute events to themselves. The study awaits replication with larger samples, but we tentatively suggest that the investigation of psychosis-related cognitive biases may prove useful for the understanding and treatment of BPD.

Kaiser Permanente's performance improvement system, part 2: developing a value framework

BACKGROUND

In 2008, Kaiser Permanente began phased implementation of a nationwide performance improvement (PI) system. The aim was to improve performance by providing consistent, highly meaningful performance measurement, increase PI skills in staff at all levels, develop organizational capabilities, and provide support for making improvements in medical centers and across regions. Evaluating the PI System: The intermediate results of the PI system were assessed in the 22 medical centers in four of the eight Kaiser Permanente regions. Implementation for 3 of these medical centers occurred in January 2008 through November 2008, with implementation for the remaining 19 medical centers occurring from September 2008 through September 2009.

FINDINGS

The 22 medical centers that were evaluated achieved a 61% improvement in selected capabilities, and improvement advisors (IAs) successfully completed 84% of initial PI projects. For each dollar invested, estimates suggested an average return on investment of $2.36.

LESSONS LEARNED

Critical factors include adequate dedicated time for PI activities by staff with necessary expertise, expert support to operations, alignment of projects with regional and national strategic priorities, and close working relationships between PI staff and operational management. Involving finance leaders in improvement planning, prioritization, and oversight is important. These elements can be adapted to smaller systems and single hospitals.

CONCLUSIONS

The initial evaluation of the Kaiser Permanente PI system indicated that (1) IAs successfully led projects in conjunction with frontline teams, (2) organizational capabilities increased, and (3) the investment in PI infrastructure and staff was sound. Expansion throughout the entire Kaiser Permanente system is under way.

Quality of life in thalassemia: a comparison of SF-36 results from the thalassemia longitudinal cohort to reported literature and the US norms

Thalassemia is a chronic, inherited blood disorder, which, in its most severe form, causes life-threatening anemia. Advances in treatment have led to increased life expectancy however the need for chronic blood transfusions and chelation therapy remains a significant burden for patients. Our study compared health related quality of life (HRQOL) from the Thalassemia Clinical Research Network's (TCRNs) Thalassemia Longitudinal Cohort (TLC) study to US norms and assessed association with clinical variables. There were 264 patients over age 14 who completed the Medical Outcomes Study 36-Item Short Form Health Survey version 2 (SF36v2) baseline assessment. When compared to US norms, TLC patients had statistically significant (P < 0.05) worse HRQOL on five of the eight subscales (physical functioning, role-physical, general health, social functioning, and role-emotional) and on both summary scales (physical component summary and mental component summary). Women, older patients, and those with more disease complications and side effects from chelation reported lower HRQOL. In general, adolescents and adults with thalassemia report worse HRQOL than the US population, despite contemporary therapy. The SF-36 should become a standard instrument for assessing HRQOL in thalassemia to determine predictors of low HRQOL which may be better addressed by a multidisciplinary team.

[Current concepts for experimental micro-CT in small animals]

The number of publications describing the use of micro-computed tomography (microCT) for preclinical in vivo imaging of small animals has risen considerably within the last few years. The purpose of this review is to familiarize the reader with the basic principles of microCT, to present successful experimental approaches in order of the evaluated organ system, and to highlight limitations that need to be considered when planning microCT-based studies.

Regular-to-chaotic tunneling rates using a fictitious integrable system

We derive a formula predicting dynamical tunneling rates from regular states to the chaotic sea in systems with a mixed phase space. Our approach is based on the introduction of a fictitious integrable system that resembles the regular dynamics within the island. For the standard map and other kicked systems we find agreement with numerical results for all regular states in a regime where resonance-assisted tunneling is not relevant.

Developing Quality Measures for Sepsis Care in the ICU

BACKGROUND

Sepsis is associated with increased morbidity, mortality, and costs of care. Although several therapies improve outcomes in patients with sepsis, rigorously developed measures to evaluate quality of sepsis care in the intensive care unit (ICU) are lacking.

METHODS

To select an initial set of candidate measures, in 2003-2004 an interdisciplinary panel reviewed the literature and used a modified nominal group technique to identify interventions that improve outcomes of patients with sepsis in the ICU. Design specifications or explicit definitions for each candidate measure were developed.

RESULTS

Ten potential measures were identified: vancomycin administration, time to vancomycin initiation, broad-spectrum antibiotic administration, time to broad-spectrum antibiotic initiation, blood culture collection, steroid administration, corticotropin stimulation test administration, activated protein C eligibility assessment, activated protein C administration, and vancomycin discontinuation.

DISCUSSION

The identification of potential measures of quality of care for patients with sepsis can help caregivers to focus on evidence-based interventions that improve mortality and to evaluate their current performance. Further work is needed to evaluate the feasibility and validity of the measures.

Cochrane Skin Group systematic reviews are more methodologically rigorous than other systematic reviews in dermatology

BACKGROUND

The Cochrane collaboration aims to produce high-quality systematic reviews. It is not known whether the methods used in producing Cochrane Skin Group (CSG) reviews result in higher quality reviews than other systematic reviews in dermatology.

OBJECTIVES

To determine how the methodological quality of dermatological CSG reviews published in The Cochrane Library and in peer-reviewed journals compare with non-Cochrane systematic reviews.

METHODS

Two blinded investigators independently assessed review quality using the 10-item Oxman and Guyatt scale.

RESULTS

Thirty-eight systematic reviews (17 Cochrane reviews published in The Cochrane Library, 11 Cochrane reviews published in peer-reviewed journals and 10 non-Cochrane reviews published in peer-reviewed journals) were examined. The Cochrane Library reviews included quality of life (11/17 vs. 1/10, P = 0.014) and adverse outcomes (14/17 vs. 2/10, P = 0.003) more often than non-Cochrane reviews published in peer-reviewed journals. Cochrane reviews published in both peer-reviewed journals and The Cochrane Library were more likely to include comprehensive search strategies (11/11 and 17/17 vs. 6/10, P-values = 0.04 and 0.01), take steps to minimize selection bias (11/11 and 16/17 vs. 3/10, P-values = 0.003 and 0.001) and appropriately assess the validity of all included trials (10/11 and 16/17 vs. 4/10, P-values = 0.04 and 0.007) than non-Cochrane reviews. Overall, Cochrane reviews published both in peer-reviewed journals and in The Cochrane Library were assigned higher quality scores by reviewers than non-Cochrane reviews (median = 6.0 and 6.5 vs. 4.5, P-values = 0.01 and 0.002).

CONCLUSIONS

The Cochrane Library systematic review methodology leads to higher quality reviews on dermatological topics.

Statins and fibrates for preventing melanoma

BACKGROUND

Effective treatment for advanced melanoma is lacking. While no drug therapy currently exists for prevention of melanoma, in vitro, case-control, and animal model evidence suggest that lipid-lowering medications, commonly taken for high cholesterol, might prevent melanoma.

OBJECTIVES

To assess the effects of statin or fibrate lipid-lowering medications on melanoma outcomes.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (February 2003), CENTRAL (The Cochrane Library Issue 1, 2005), MEDLINE (to March 2003), EMBASE (to September 2003), CANCERLIT (to October 2002), Web of Science (to May 2003), and reference lists of articles. We approached study investigators and pharmaceutical companies for additional information (published or unpublished studies).

SELECTION CRITERIA

Trials involving random allocation of study participants, where experimental groups used statins or fibrates and participants were enrolled for at least four years of therapy.

DATA COLLECTION AND ANALYSIS

Three authors screened 109 abstracts of articles with titles of possible relevance. We then thoroughly examined the full text of 72 potentially relevant articles. We requested unpublished melanoma outcomes data from the corresponding author of each qualifying trial.

MAIN RESULTS

We identified 16 qualifying randomised controlled trials (RCTs) (seven statin, nine fibrate). Thirteen of these trials (involving 62,197 participants) provided data on incident melanomas (six statin, seven fibrate). A total of 66 melanomas were reported in groups receiving the experimental drug and 86 in groups receiving placebo or other control therapies. For statin trials this translated to an odds ratio of 0.90 (95% confidence interval 0.56 to 1.44) and for fibrate trials an odds ratio of 0.58 (95% confidence interval 0.19 to 1.82). Subgroup analyses failed to show statistically significant differences in melanoma outcomes by gender, melanoma occurrence after two years of participation in trial, stage or histology, or trial funding. Subgroup analysis by type of fibrate or statin also failed to show statistically significant differences, except for the statin subgroup analysis which showed reduced melanoma incidence for lovastatin, based on one trial only (odds ratio 0.52, 95% confidence interval 0.27 to 0.99).

AUTHORS' CONCLUSIONS

The melanoma outcomes data collected in this review of RCTs of statins and fibrates does not exclude the possibility that these drugs prevent melanoma. There was a 10% and 42% reduction for participants on statins and fibrates, respectively, however these results were not statistically significant. Until further evidence is established, limiting exposure to ultraviolet radiation remains the most effective way to reduce the risk of melanoma.

Circadian periodicity of cerebral blood flow revealed by laser-Doppler flowmetry in awake rats: relation to blood pressure and activity

Cardiovascular parameters such as arterial blood pressure (ABP) and heart rate display pronounced circadian variation. The present study was performed to detect whether there is a circadian periodicity in the regulation of cerebral perfusion. Normotensive Sprague-Dawley rats (SDR, approximately 15 wk old) and hypertensive (mREN2)27 transgenic rats (TGR, approximately 12 wk old) were instrumented in the abdominal aorta with a blood pressure sensor coupled to a telemetry system for continuous recording of ABP, heart rate, and locomotor activity. After 5-12 days, a laser-Doppler flow (LDF) probe was attached to the skull by means of a guiding device to measure changes in brain cortical blood flow (CBF). After the animals recovered from anesthesia, measurements were taken for 3-4 days. The time series were analyzed with respect to the midline estimating statistic of rhythm (i.e., mean value of a periodic event after fit to a cosine function), amplitude, and acrophase (i.e., phase angle that corresponds to the peak of a given period) of the 24-h period. The LDF signal displayed a significant circadian rhythm, with the peak occurring at around midnight in SDR and TGR, despite inverse periodicity of ABP in TGR. This finding suggests independence of LDF periodicity from ABP regulation. Furthermore, the acrophase of the LDF was consistently found before the acrophase of the activity. From the present data, it is concluded that there is a circadian periodicity in the regulation of cerebral perfusion that is independent of circadian changes in ABP and probably is also independent of locomotor activity. The presence of a circadian periodicity in CBF may have implications for the occurrence of diurnal alterations in cerebrovascular events in humans.

Experimental approaches to evaluate endothelin-A receptor antagonists

A large body of evidence suggests a substantial role of the endothelin (ET) system in the pathophysiology of a variety of disease states, mainly of the cardiovascular system. Recently bosentan, an ET receptor antagonist, has received approval by the Food and Drug Administration (FDA) for use in pulmonary artery hypertension. The ET system may also be involved in cerebrovascular disorders such as stroke and, most notably, development of cerebral vasospasm following subarachnoid hemorrhage. The pathophysiological mechanisms contributing to the development of a cerebral vasospasm after subarachnoid hemorrhage may be taken as a paradigm to explore mechanisms leading to secondary ischemic brain damages in a variety of insults such as stroke and trauma. The present review provides the evidence to evaluate ET receptor antagonists for potential prophylactic and therapeutic use in patients suffering from subarachnoid hemorrhage. The rationale to develop selective ETA receptor antagonists is given with respect to basic and applied studies. This may be useful to better define the desired profile of action of a given compound, and it may also help to design appropriate preclinical and clinical trials, most desirably in close cooperation with pharmaceutical companies and neurosurgical departments.

Growth/differentiation factor-15 (GDF-15), a novel member of the TGF-beta superfamily, promotes survival of lesioned mesencephalic dopaminergic neurons in vitro and in vivo and is induced in neurons following cortical lesioning

This review summarizes the evidence that GDF-15, a recently discovered member of the TGF-beta superfamily, is a trophic factor for nigral dopamine neurons, both in vitro and in vivo. Specifically, GDF-15 promotes survival and differentiation of embryonic rat dopaminergic neurons, but not of other neuron populations, with the exception of serotonergic raphe neurons. The neurotrophic effect of GDF-15 seems to be direct and not mediated through glial cells. In the rat 6-hydroxydopamine model of parkinsonism GDF-15 rescues intoxicated dopaminergic neurons and abolishes abnormal turning behavior. The most prominent site of synthesis of GDF-15 within the brain is the choroid plexus, which secretes GDF-15 into the cerebrospinal fluid, from where the molecule can penetrate through the ependymal layer into the parenchyma. Analysis of mouse mutants lacking GDF-15 will reveal whether the endogenous factor also has a role in promoting embryonic and protecting lesioned nigral dopamine neurons.

Outpatient case presentations in the conference room versus examination room: results from two randomized controlled trials

PURPOSE

Ambulatory case presentations occur typically in conference rooms, and attending physicians often have little contact with patients. The purpose of this study was to examine the effects of two different ambulatory case presentation formats that involve attending physicians more directly.

SUBJECTS AND METHODS

We conducted two randomized controlled trials in a community-based ambulatory internal medicine clinic. Participants comprised 393 adult patients, 40 house officers, and 14 attending physicians. In the first trial, patient encounters were assigned randomly to either exclusive house officer-attending physician conference room discussion or to house officer-attending physician conference room discussion plus attending physician-patient interaction. In the second trial, patient encounters were assigned randomly to either exclusive house officer-attending physician conference room discussion or to exclusive house officer-attending physician discussion in the examining room with the patient present. Patient satisfaction; attending physician contributions to teaching, diagnosis, and therapy; and house officer comfort and autonomy were assessed.

RESULTS

Patient visit satisfaction and house officer assessment of attending physician teaching, diagnosis, and therapy were similar in the control and intervention groups of both trials. Patients involved in examination room discussions thought they were more comfortable with the discussion (mean +/- SD, 4.3 +/- 0.9 vs. 3.4 +/- 0.9 on a one- to five-point Likert scale, P <0.001) and more often indicated a preference to listen to the discussion in the future than did the control group (86% [71/83] vs. 63% [52/83], P <0.001). Some house officers (11% [9/83]) but no attending physicians (0/83, P <0.001) were made uncomfortable by examination room presentations, and some house officers (11% [9/83]) thought that examination room presentations diminished their autonomy.

CONCLUSIONS

Patients perceive that ambulatory examination room presentations are beneficial, whereas some house officers perceive that examination room presentations are associated with discomfort and diminished autonomy.

Impact of a simple intervention to increase primary care provider recognition of patient referral concerns

OBJECTIVE

To determine whether a brief previsit questionnaire about referral concerns can improve primary care provider (PCP) recognition of patient concerns and satisfaction with care.

DESIGN

Sequential prospective study in the internal medicine clinic of an academic medical center providing primary care to patients enrolled in a gatekeeper-model managed care plan.

PARTICIPANTS AND METHODS

Twelve faculty internists serving as PCPs for 1495 consecutive patient visits. Patients were given a previsit questionnaire asking about referral need and rationale and a postvisit questionnaire asking about discussion of referral concern and visit satisfaction. Providers were given a postvisit questionnaire asking whether a referral was discussed and made and about visit satisfaction. In the control phase, patient previsit questionnaires remained confidential, whereas in the intervention phase PCPs were shown the previsit questionnaires at the time of encounter.

RESULTS

The intervention significantly increased PCP referral recognition from 61% to 81% (P < .001) and was associated with increased visit satisfaction (P = .05). Satisfaction of PCPs with the referral discussion, overall rate of referral, and visit duration were not affected by the intervention.

CONCLUSIONS

Using a brief previsit questionnaire about patient referral concerns increases PCP recognition of such concerns. The intervention does not adversely affect PCP satisfaction with the referral discussion or the overall referral rate and may enhance patient visit satisfaction.

Expression of growth differentiation factor-15/ macrophage inhibitory cytokine-1 (GDF-15/MIC-1) in the perinatal, adult, and injured rat brain

We and others have recently cloned a new member of the transforming growth factor-beta superfamily, growth differentiation factor-15/ macrophage inhibitory cytokine-1 (GDF-15/MIC-1). Using in situ hybridization and immunohistochemistry, we determined the distribution of GDF-15/MIC-1 mRNA and protein in the perinatal and cryolesioned adult rat brain. The choroid plexus epithelium of all ventricles represents the site of strongest and almost exclusive mRNA expression in the normal perinatal and adult brain. The newborn rat brain reveals GDF-15/MIC-1 immunoreactivity (ir) in ependymal cells lining the ventricles, in the striatal subventricular zone, and in populations of nonneural cells of the thalamic/hippocampal lamina affixa, in addition to that in the choroid plexus. Unilateral cryogenic cortical lesioning induced a significant increase of GDF-15/MIC-1 mRNA expression and ir at the lesion site and expression in presumed neurons within the dorsal thalamic area. At the lesion site, GDF-15/MIC-1-producing cells showed immuncytochemical features of neurons, macrophages, and activated microglial cells. Fluorescent microscopy revealed both intra- and extracellular GDF-15/MIC-1 ir. Up-regulation of GDF-15/MIC-1 in activated macrophages (Mstraight phi) is also supported by RT-PCR, ICC, and Western blot experiments showing pronounced induction of GDF-15/MIC-1 expression (mRNA and protein) in retinoic acid/phorbol ester-stimulated human M phi. Our data suggest that 1) GDF-15/MIC-1 is secreted into the cerebrospinal fluid and 2) in the newborn brain may penetrate through the ependymal lining and act on developing neurons and/or glial cells. As a constituent of cells in the lamina affixa, the protein might be involved in the regulation of mesenchyme-epithelial interactions. Finally, GDF-15/MIC-1 may also act within the antiinflammatory cytokine network activated in CNS lesions.

Xenon-induced flow activation in patients with cerebral insult who undergo xenon-enhanced CT blood flow studies

BACKGROUND AND PURPOSE

Stable xenon-enhanced CT ((s)Xe/CT) has gained wide acceptance in the assessment of regional cerebral blood flow (rCBF) in patients with intracranial abnormalities. The aim of this study was to test whether the contrast medium (ie, (s)Xe) itself directly induces relevant changes in rCBF, thereby distorting any valid determination of cerebral perfusion by using (s)Xe/CT.

METHODS

To characterize the degree and temporal dynamics of (s)Xe-induced flow activation, a thermal diffusion (TD)-based microprobe was placed subcortically into the frontal lobe on either hemisphere to assess rCBF (TD-rCBF) continuously in 23 patients (mean age, 55 +/- 18 years) with severe intracranial insult who were undergoing (s)Xe/CT.

RESULTS

In 35, the (s)Xe/CT studies TD-rCBF rose from 25 +/- 17 mL/100 g per minute (range, 5-42 mL/100 g per minute) before (s)Xe administration to 28 +/- 21 mL/100 g per minute (range, 6-46 mL/100 g per minute) after arterial (s)Xe saturation was reached. Analysis of the flow activation curve showed a logarithmic shape with an increase in TD-rCBF between 3% and 7% within the first 76 seconds of (s)Xe wash-in (12% after 190 seconds) and showed no further augmentation until the end of the blood flow study.

CONCLUSION

The observed (s)Xe-induced rCBF activation, which showed significant inter- and intraindividual variability, might lead to overestimation of rCBF in patients with severe intracranial insult. The obtained flow activation curve provides essential information that may allow subsequent refinement of the methodology, aiming to further minimize the influence of (s)Xe-induced rCBF activation on rCBF calculations when using (s)Xe/CT technology.

Time course of apoptotic cell death after experimental neurotrauma

Traumatic or ischemic brain injury may give rise to the development of secondary brain damage. In the present study the time course of TUNEL staining which is widely used to delineate apoptotic reaction pattern was followed after experimental neurotrauma in order to test the hypothesis that apoptotic cell death may be involved in the development of secondary brain damage. Neurotrauma was induced in male Wistar rats by applying a cold probe to the exposed dura over the temporo-parietal cortex. Animals were sacrificed between 1 and 72 hours after trauma and coronal sections prepared from the lesioned area and adjacent tissue. The TUNEL staining was employed to detect DNA-fragmentation and conventional HE staining of sequential slices to delineate the extent of the lesion. Occurrence of positively stained cells was detected by a computer-based quantification system and stored on hard disk. TUNEL-positive nuclei were observed as early as one hour after lesion and peaked at 3 hours. There after, the number of cells detected decreased steadily. Histological examination revealed two different types of morphology in TUNEL-positive cells. A small proportion termed type I-cells displayed additional signs of apoptotic cell death such as nuclear condensation and fragmentation while type-II were considered to undergo necrotic cell death. Thus, TUNEL staining proved to be an unspecific marker of apoptotic cell death in the present study. Nevertheless, the data suggest that apoptotic cell death does not contribute substantially to the final extent of cold induced brain tissue damage.