Dynamic compartmentalization of bacteria: accurate division in E. coli

Positioning of the midcell division plane within the bacterium E. coli is controlled by the min system of proteins: MinC, MinD and MinE. These proteins coherently oscillate from end to end of the bacterium. We present a reaction--diffusion model describing the diffusion of min proteins along the bacterium and their transfer between the cytoplasmic membrane and cytoplasm. Our model spontaneously generates protein oscillations in good agreement with experiments. We explore the oscillation stability, frequency and wavelength as a function of protein concentration and bacterial length.Comment: 4 pages, 4 figures, Latex2e, Revtex

Can prolonged sick leave after gynecologic surgery be predicted? An observational study in the Netherlands

BACKGROUND: Sick leave frequently has been used as an outcome to evaluate minimal invasive surgery compared with conventional open surgery. However, sick leave is determined not only by the surgical approach. Recently, a postoperative recovery-specific quality-of-life questionnaire, the Recovery Index (RI-10), has been developed and validated. This study investigated the relation of the Recovery Index 10, the RI-6 (a subset of 6 questions), and the type of surgery to sick leave. METHODS: The study enrolled 46 patients with a paid job scheduled for elective gynecologic surgery, who filled out the RI-10. After 8 weeks, the patients were approached by telephone to give information on their return to work. RESULTS: Of the 46 patients, 23 (50%) returned to work completely after 8 weeks, 14 (30%) resumed work partly, and 9 (20%) did not resume work at all. In the analysis, the patients who completely returned to work were compared with those who did not return or partially returned. Recovery as expressed in the RI-6 improved with time after surgery. It appeared that the measurement 2 weeks after surgery showed the best discriminative capacity to predict sick leave after 8 weeks, with an area under the curve of 0.88 (confidence interval, 0.74-1.03). The subjective postoperative recovery as expressed by the RI-6 is more closely related to the type of surgery (p = 0.001) sick leave is (p = 0.14). CONCLUSIONS: The subjective recovery scored by the patient on a questionnaire of six questions is a better outcome than sick leave for evaluating surgical approaches. If administered 2 weeks after surgery, it may predict prolonged sick leav

Development of the Gambling Disorder Identification Test: Results from an international Delphi and consensus process

Objectives Diverse instruments are used to measure problem gambling and Gambling Disorder intervention outcomes. The 2004 Banff consensus agreement proposed necessary features for reporting gambling treatment efficacy. To address the challenge of including these features in a single instrument, a process was initiated to develop the Gambling Disorder Identification Test (GDIT), as an instrument analogous to the Alcohol Use Disorders Identification Test and the Drug Use Disorders Identification Test. Methods Gambling experts from 10 countries participated in an international two‐round Delphi (n = 61; n = 30), rating 30 items proposed for inclusion in the GDIT. Gambling researchers and clinicians from several countries participated in three consensus meetings (n = 10; n = 4; n = 3). User feedback was obtained from individuals with experience of problem gambling (n = 12) and from treatment‐seekers with Gambling Disorder (n = 8). Results Ten items fulfilled Delphi consensus criteria for inclusion in the GDIT (M ≥ 7 on a scale of 1–9 in the second round). Item‐related issues were addressed, and four more items were added to conform to the Banff agreement recommendations, yielding a final draft version of the GDIT with 14 items in three domains: gambling behavior, gambling symptoms and negative consequences. Conclusions This study established preliminary construct and face validity for the GDIT

Rating the methodological quality in systematic reviews of studies on measurement properties: a scoring system for the COSMIN checklist

Background: The COSMIN checklist is a standardized tool for assessing the methodological quality of studies on measurement properties. It contains 9 boxes, each dealing with one measurement property, with 5-18 items per box about design aspects and statistical methods. Our aim was to develop a scoring system for the COSMIN checklist to calculate quality scores per measurement property when using the checklist in systematic reviews of measurement properties. Methods: The scoring system was developed based on discussions among experts and testing of the scoring system on 46 articles from a systematic review. Four response options were defined for each COSMIN item (excellent, good, fair, and poor). A quality score per measurement property is obtained by taking the lowest rating of any item in a box ("worst score counts"). Results: Specific criteria for excellent, good, fair, and poor quality for each COSMIN item are described. In defining the criteria, the "worst score counts" algorithm was taken into consideration. This means that only fatal flaws were defined as poor quality. The scores of the 46 articles show how the scoring system can be used to provide an overview of the methodological quality of studies included in a systematic review of measurement properties. Conclusions: Based on experience in testing this scoring system on 46 articles, the COSMIN checklist with the proposed scoring system seems to be a useful tool for assessing the methodological quality of studies included in systematic reviews of measurement properties. © The Author(s) 2011

Initial psychological responses to influenza A, H1N1 ("Swine flu")

Background The outbreak of the pandemic flu, Influenza A H1N1 (Swine Flu) in early 2009, provided a major challenge to health services around the world. Previous pandemics have led to stockpiling of goods, the victimisation of particular population groups, and the cancellation of travel and the boycotting of particular foods (e.g. pork). We examined initial behavioural and attitudinal responses towards Influenza A, H1N1 ("Swine flu") in the six days following the WHO pandemic alert level 5, and regional differences in these responses. Methods 328 respondents completed a cross-sectional Internet or paper-based questionnaire study in Malaysia (N = 180) or Europe (N = 148). Measures assessed changes in transport usage, purchase of preparatory goods for a pandemic, perceived risk groups, indicators of anxiety, assessed estimated mortality rates for seasonal flu, effectiveness of seasonal flu vaccination, and changes in pork consumption Results 26% of the respondents were 'very concerned' about being a flu victim (42% Malaysians, 5% Europeans, p < .001). 36% reported reduced public transport use (48% Malaysia, 22% Europe, p < .001), 39% flight cancellations (56% Malaysia, 17% Europe, p < .001). 8% had purchased preparatory materials (e.g. face masks: 8% Malaysia, 7% Europe), 41% Malaysia (15% Europe) intended to do so (p < .001). 63% of Europeans, 19% of Malaysians had discussed the pandemic with friends (p < .001). Groups seen as at 'high risk' of infection included the immune compromised (mentioned by 87% respondents), pig farmers (70%), elderly (57%), prostitutes/highly sexually active (53%), and the homeless (53%). In data collected only in Europe, 64% greatly underestimated the mortality rates of seasonal flu, 26% believed seasonal flu vaccination gave protection against swine flu. 7% had reduced/stopped eating pork. 3% had purchased anti-viral drugs for use at home, while 32% intended to do so if the pandemic worsened. Conclusion Initial responses to Influenza A show large regional differences in anxiety, with Malaysians more anxious and more likely to reduce travel and to buy masks and food. Discussions with family and friends may reinforce existing anxiety levels. Particular groups (homosexuals, prostitutes, the homeless) are perceived as at greater risk, potentially leading to increased prejudice during a pandemic. Europeans underestimated mortality of seasonal flu, and require more information about the protection given by seasonal flu inoculation

A questionnaire to identify patellofemoral pain in the community: an exploration of measurement properties

Background Community-based studies of patellofemoral pain (PFP) need a questionnaire tool that discriminates between those with and those without the condition. To overcome these issues, we have designed a self-report questionnaire which aims to identify people with PFP in the community. Methods Study designs: comparative study and cross-sectional study. Study population: comparative study: PFP patients, soft-tissue injury patients and adults without knee problems. Cross-sectional study: adults attending a science festival. Intervention: comparative study participants completed the questionnaire at baseline and two weeks later. Cross-sectional study participants completed the questionnaire once. The optimal scoring system and threshold was explored using receiver operating characteristic curves, test-retest reliability using Cohen’s kappa and measurement error using Bland-Altman plots and standard error of measurement. Known-group validity was explored by comparing PFP prevalence between genders and age groups. Results Eighty-four participants were recruited to the comparative study. The receiver operating characteristic curves suggested limiting the questionnaire to the clinical features and knee pain map sections (AUC 0.97 95 % CI 0.94 to 1.00). This combination had high sensitivity and specificity (over 90 %). Measurement error was less than the mean difference between the groups. Test–retest reliability estimates suggest good agreement (N = 51, k = 0.74, 95 % CI 0.52–0.91). The cross-sectional study (N = 110) showed expected differences between genders and age groups but these were not statistically significant. Conclusion A shortened version of the questionnaire, based on clinical features and a knee pain map, has good measurement properties. Further work is needed to validate the questionnaire in community samples

Progression and Regression: Distinct Developmental Patterns of Diabetic Retinopathy in Patients With Type 2 Diabetes Treated in the Diabetes Care System West-Friesland, the Netherlands

OBJECTIVE: To identify distinct developmental patterns of diabetic retinopathy (DR) and assess the risk factor levels of patients in these clusters. RESEARCH DESIGN AND METHODS: A cohort of 3,343 patients with type 2 diabetes mellitus (T2DM) monitored and treated in the Diabetes Care System West-Friesland, the Netherlands, was followed from 2 to 6 years. Risk factors were measured, and two-field fundus photographs were taken annually and graded according to the EURODIAB study group. Latent class growth modeling was used to identify distinct developmental patterns of DR over time. RESULTS: Five clusters of patients with distinct developmental patterns of DR were identified: A, patients without any signs of DR (88.9%); B, patients with a slow regression from minimal background to no DR (4.9%); C, patients with a slow progression from minimal background to moderate nonproliferative DR (4.0%); D, patients with a fast progression from minimal or moderate nonproliferative to (pre)proliferative or treated DR (1.4%); and E, patients with persistent proliferative DR (0.8%). Patients in clusters A and B were characterized by lower risk factor levels, such as diabetes duration, HbA(1c), and systolic blood pressure compared with patients in progressive clusters (C-E). CONCLUSIONS: Clusters of patients with T2DM with markedly different patterns of DR development were identified, including a cluster with regression of DR. These clusters enable a more detailed examination of the influence of various risk factors on DR

The aesthetic items scale: A tool for the evaluation of aesthetic outcome after breast reconstruction

__Background:__ Valid tools to assess aesthetic outcomes after breast reconstructive surgery are scarce. Previously a professional aesthetic assessment scale was introduced, the Aesthetic Items Scale (AIS). We aim to determine if this method is a valid and reliable tool to assess aesthetic outcome after breast reconstructive surgery. __Methods:__ The study population was consenting women who underwent prophylactic mastectomy with subsequent implant-based breast reconstruction. The aesthetic outcome with regard to breast volume, shape, symmetry, scars, and nipple areola complex was rated on a 5-point scale using standardized photographs to give a summed total score. Photographs were evaluated by the patient, 5 plastic surgeons, and 3 mammography nurses. An overall rating of aesthetic outcome on a 1-10 scale was given separately. We determined the intraclass correlation coefficient and assessed interobserver agreement. To assess validity, we calculated the correlation between total score and overall rating of aesthetic outcome. __Results:__ Interobserver reliability was highest between plastic surgeons for the subitem and overall scores and ranged between 0.56 and 0.82. The summed score of the AIS correlates strongly with the overall rating in professionals but not in patients. __Conclusions:__ The AIS is a valid and reliable method for evaluating aesthetic outcome of breast reconstruction by plastic surgeons. The results indicate that patients judge aesthetic outcome differently, taking into account factors that are not represented in the AIS. Professionals can use this method to evaluate surgical results, but other measurements are needed to map satisfaction of the patient with her breasts

The COSMIN checklist for evaluating the methodological quality of studies on measurement properties: A clarification of its content

<p>Abstract</p> <p>Background</p> <p>The COSMIN checklist (COnsensus-based Standards for the selection of health status Measurement INstruments) was developed in an international Delphi study to evaluate the methodological quality of studies on measurement properties of health-related patient reported outcomes (HR-PROs). In this paper, we explain our choices for the design requirements and preferred statistical methods for which no evidence is available in the literature or on which the Delphi panel members had substantial discussion.</p> <p>Methods</p> <p>The issues described in this paper are a reflection of the Delphi process in which 43 panel members participated.</p> <p>Results</p> <p>The topics discussed are internal consistency (relevance for reflective and formative models, and distinction with unidimensionality), content validity (judging relevance and comprehensiveness), hypotheses testing as an aspect of construct validity (specificity of hypotheses), criterion validity (relevance for PROs), and responsiveness (concept and relation to validity, and (in) appropriate measures).</p> <p>Conclusions</p> <p>We expect that this paper will contribute to a better understanding of the rationale behind the items, thereby enhancing the acceptance and use of the COSMIN checklist.</p

Observational pain assessment in older persons with dementia in four countries:observer agreement of items and factor structure of the Pain Assessment in Impaired Cognition

Background: Recognition of pain in people with dementia is challenging. Observational scales have been developed, but there is a need to harmonize and improve the assessment process. In EU initiative COST-Action TD1005, 36 promising items were selected from existing scales to be tested further. We aimed to study the observer agreement of each item, and to analyse the factor structure of the complete set. Methods: One hundred and ninety older persons with dementia were recruited in four different countries (Italy, Serbia, Spain and The Netherlands) from different types of healthcare facilities. Patients represented a convenience sample, with no pre-selection on presence of (suspected) pain. The Pain Assessment in Impaired Cognition (PAIC, research version) item pool includes facial expressions of pain (15 items), body movements (10 items) and vocalizations (11 items). Participants were observed by health professionals in two situations, at rest and during movement. Intrarater and interrater reliability was analysed by percentage agreement. The factor structure was examined with principal component analysis with orthogonal rotation. Results: Health professionals performed observations in 40–57 patients in each country. Intrarater and interrater agreement was generally high (≥70%). However, for some facial expression items, agreement was sometimes below 70%. Factor analyses showed a six-component solution, which were named as follows: Vocal pain expression, Face anatomical descriptors, Protective body movements, Vocal defence, Tension and Lack of affect. Conclusions: Observation of PAIC items can be done reliably in healthcare settings. Observer agreement is quite promising already without extensive training. Significance: In this international project, promising items from existing observational pain scales were identified and evaluated regarding their reliability as an alternative to pain self-report in people with dementia. Analysis on factor structure helped to understand the character of the items. Health professionals from four countries using four different European languages were able to rate items reliably. The results contributed to an informed reduction of items for a clinical observer scale (Pain Assessment in Impaired Cognition scale with 15 items: PAIC15)