Cultured cortical networks described by conditional firing probabilities

Networks of cortical neurons were grown over multi electrode arrays to enable simultaneous measu-rement of action potentials from 60 electrodes. All possible pairs of electrodes (i,j) were tested for syn-chronized activity. We calculated conditional firing probability (CFPi,j[τ]) as the probability of an action potential at electrode j at t=τ, given that a spike was detected at i at t=0. If a CFPi,j[τ] distribution clearly deviated from flat, electrodes i and j were considered related. A function was fitted to each CFP-curve to obtain parameters for strength and delay. In young cultures the set of identified relationships changed rather quickly. At 16 days in vitro (DIV) 50% of the set changed within one day. Beyond 25 DIV this set stabilized: during a period of a week more than 50% of the set remained intact. Most individual relationships developed rather gradually. Moreover, beyond 25 DIV relational strength appeared quite stable during periods of ≈ 10 hours, with coefficients of variation (100×SD/mean) of ≈ 25% on average. CFP analysis provides a robust method to describe the stable underlying probabilistic structure of highly varying spontaneous activity in cultured cortical networks. It may offer a suitable basis for plasticity studies, in which induced changes should exceed spontaneous fluctuations. CFP analysis is likely to describe the network in sufficient detail to detect subtle changes in individual relationships. Analysis of data continuously recorded for ≈ 6 weeks, showed that highest stability is reached after ≈ 25 DIV, suggesting the 4th and 5th week as a suitable period for plasticity studies.\ud \u

Rapid detection of methicillin resistance in Staphylococcus aureus isolates by the MRSA-screen latex agglutination test

The slide agglutination test MRSA-Screen (Denka Seiken Co., Niigata, Japan) was compared with the mecA PCR ("gold standard") for the detection of methicillin resistance in Staphylococcus aureus. The MRSA-Screen test detected the penicillin-binding protein 2a (PBP2a) antigen in 87 of 90 genetically diverse methicillin-resistant S. aureus (MRSA) stock culture strains, leading to a sensitivity of 97%. The three discrepant MRSA strains displayed positive results only after induction of the mecA gene by exposure to methicillin. Both mecA PCR and MRSA-Screen displayed negative results among the methicillin-susceptible S. aureus strains (n = 106), as well as for Micrococcus spp. (n = 10), members of the family Enterobacteriaceae (n = 10), Streptococcus pneumoniae (n = 10), and Enterococcus spp. (n = 10) (specificity = 100%). Producing the same PBP2a antigen, all 10 methicillin-resistant Staphylococcus epidermidis strains score positived in both the latex test and the mecA PCR. Consequently, the MRSA-Screen test should be applied only after identification of the MRSA strain to the species level to rule out coagulase-negative staphylococci. In conclusion, due to excellent specificity and sensitivity the MRSA-Screen latex test has the potential to be successfully used for routine applications in the microbiology laboratory

Patient perceived needs and experiences of person-centered care in patients with inflammatory arthritis

BACKGROUND: Health care is shifting toward a person-centered care (PCC) approach. For implementation of PCC, there may be a special role for nurse practitioners (NPs). PURPOSE: The aim of this study was to explore the patient-perceived levels of and needs for of PCC in inflammatory arthritis patients who visited the NP at the outpatient clinic of an academic hospital in the Netherlands. METHODS: A cross-sectional study was performed. Disease characteristics were inventoried from the patient records. Patients filled out the PCCoc/rheum instrument, an instrument to measure patient perceived PCC, and a questionnaire based on the 14 life areas of the Self-Management Web, extended with areas including pain, fatigue, and night's rest. Participants were asked which life areas caused problems, and whether these problems were discussed. Mean values were calculated for normally distributed data and medians for nonnormally distributed data. RESULTS: Most of the patients had well-controlled disease (86.1%). The mean score of the PCCoc/rheum was 55.3 (SD 8.1). Patients experienced most problems in life areas fatigue (37.3%) and pain (35.3%), these were also the life areas that were most often addressed at consultation. The life areas that gave problems and that were least addressed during consultation were intimate relationships & sexuality (66.7%) and household chores (58.8%). CONCLUSIONS: Despite an overall high level of patient perceived PCC delivered by NPs, patient with low disease activity frequently reported problems in life areas not addressed at consultation. IMPLICATIONS FOR PRACTICE: Implementation of the Self-Management Web and changing the focus of NP consultations may help to improve accommodating individual patient needs

Sustainable Land Use: Methodology and Application

The chapters in this volume are edited versions of papers presented at the NATO Ad- vanced Research Workshop on Environmental Change Adaptation and Security held in Budapest, Hungary, from October 16 - 18, 1997. As is evident in this volume, the papers ranged from descriptions of environmental and health issues in Russia and Eastern Europe to models of sustainable land use. This diversity of perspectives on environ- ment and security is indicative of both the breadth of this new area of research as well as the varied background of the researchers involved. The discussions at the NATO workshop were remarkably animated and exciting, not surprising given the interest in the topic. I think this vitality is reflected in the papers in this volume as well. The main purpose of the NATO ARW is to foster research links among researchers from NATO countries and Central and Eastern European States, Russia, and the Newly Independent States. In editing this volume, a decision was made to keep to the spirit of this purpose and-if at all possible-include all papers prepared for the workshop. This required extensive editing and rewriting of some of the papers (and consequent delays in production). A determination was made early in the process by the workshop steering committee that the value of publishing the entire collection of articles out- weighed the advantages of accepting only a limited number

Longitudinal Assessment of Dementia Measures in Down Syndrome

Introduction: Early detection of dementia symptoms is critical in Down syndrome (DS) but complicated by clinical assessment barriers. The current study aimed to characterize cognitive and behavioral impairment using longitudinal trajectories comparing several measures of cognitive and behavioral functioning. Methods: Measures included global cognitive status (Severe Impairment Battery [SIB]), motor praxis (Brief Praxis Test [BPT]), and clinical dementia informant ratings (Dementia Questionnaire for People with Learning Disabilities [DLD]). One-year reliability was assessed using a two-way mixed effect, consistency, single measurement intraclass correlation among non-demented participants. Longitudinal assessment of SIB, BPT, and DLD was completed using linear mixed effect models. Results: One‐year reliability (n = 52; 21 male) was moderate for DLD (0.69 to 0.75) and good for SIB (0.87) and BPT (0.80). Longitudinal analysis (n = 72) revealed significant age by diagnosis interactions for SIB (F(2, 115.02) = 6.06, P = .003), BPT (F(2, 85.59) = 4.56, P = .013), and DLD (F(2, 103.56) = 4.48, P = .014). SIB progression (PR) had a faster decline in performance versus no‐dementia (ND) (t(159) = −2.87; P = .013). Dementia had a faster decline in BPT performance versus ND (t(112) = −2.46; P = .041). PR showed quickly progressing scores compared to ND (t(128) = −2.86; P = .014). Discussion: Current measures demonstrated moderate to good reliability. Longitudinal analysis revealed that SIB, BPT, and DLD changed with age depending on diagnostic progression; no change rates were dependent on baseline cognition, indicating usefulness across a variety of severity levels in DS

Evaluating score distributions in the revised Dutch version of the Childhood Health Assessment Questionnaire

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Computed Tomography of the Coronary Arteries

MSCT Coronary Angiography is a fast developing non-invasive diagnostic technique that can detect a coronary stenosis. The detection of a coronary stenosis is hampered by limited image quality and by motion artefacts and extensive calcifications. However, MSCT-coronary angiography is highly reliable to rule out coronary stenosis. The role of MSCT-coronary angiography in the diagnostic work-up of coronary artery disease needs further research