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PPV
Kinds of PPV Terms modified by PPV Selected AbstractsO-13 ENDOMETRIAL CARCINOMA DETECTED WITH SUREPATH LIQUID BASED CERVICAL CYTOLOGY: COMPARISON WITH CONVENTIONAL CERVICAL CYTOLOGYCYTOPATHOLOGY, Issue 2006C. J. Patel Introduction:, Conventional Pap Smear (CPS) has had little impact on the detection of endometrial carcinoma (MC). Although Liquid Based Cytology (LBC) is replacing CPS in the UK, experience with identification of endometrial cancers with this is limited. A few studies of ThinPrep LBC show promise with reported increased detection rate, but to date, there has been no reported study of detection with SurePath LBC. Aim:, The purpose of this 2-year retrospective study was to compare the accuracy of the SurePath LBC with that of conventional smear in detecting endometrial cancers. Methods:, Our study group consisted of all SurePath cases of endometrial atypia/carcinoma diagnosed between 1st Jan 2004 and 31st Dec 2005, following 100% conversion of our laboratory to the SurePath system in 2001. Conventional smears reported over a 6-year period (1993,1998), comprised the control group. Histological follow up was obtained. Results:, Endometrial lesions were reported in 95 (0.07%) of 130352 SurePath LBC smears. These included 70 (0.053%) reports of endometrial atypia, 05 (0.003%) suspicious and 20 (0.015%) diagnostic of endometrial carcinoma. A total of 58 (0.014%) cases of 409495 CPS were diagnosed as endometrial carcinoma. Adequate histological follow up was available in 47 (49.5%) SurePath LBC and 52 (89.6%) conventional cases. In these, the positive predictive value (PPV) for endometrial carcinoma of SurePath LBC was 73.3% compared to 55.4% of CPS. The PPV for endometrial carcinoma of the atypical and suspicious LBC categories was 14.3% and 40% respectively. No categorisation as atypical or suspicious in the conventional study was available for comparison. The sensitivity of the SurePath LBC, calculated from retrograde analysis of histologically diagnosed endometrial cancers during the same period was 40%. Conclusion:, The SurePath LBC is at least an as accurate and sensitive method for detecting endometrial cancer as CPS. [source] Long-term follow-up of patients following negative colposcopy: a new gold standard and its implications for cervical screeningCYTOPATHOLOGY, Issue 5 2003P. D. Da Forno From 1189 colposcopy referrals in 1997 at a single cervical screening centre, 88 women who had no biopsy taken at colposcopy (negative colposcopy) were identified. We followed up these women for a maximum of 4 years and calculated the positive predictive value (PPV) of a single smear before and after follow-up. Using slide review we attempted to correlate the grade of smear leading to colposcopy referral with final outcome. Our results showed that long-term follow-up alters the PPV of cervical cytology. Analysis showed a strong correlation between the review grade of the referring smear and the final outcome after follow-up. From these results we suggest an evidence-based protocol for cervical screening follow-up after negative colposcopy. [source] Borderline nuclear change; can a subgroup be identified which is suspicious of high-grade cervical intraepithelial neoplasia, i.e. CIN 2 or worse?CYTOPATHOLOGY, Issue 5 2002J. M. Edwards Borderline nuclear change; can a subgroup be identified which is suspicious of high-grade cervical intraepithelial neoplasia, i.e. CIN 2 or worse? Only 10% of first borderline smears are associated with a histological high-grade (HG) abnormality, i.e. CIN 2,3, invasive malignancy or glandular neoplasia on subsequent investigation. The advantages of highlighting this subgroup are obvious but is this possible? From 1996 and 1997, 242 borderline smears with histological follow-up were examined by two independent experienced observers (observer 1 and 2) without prior knowledge of further investigation results. For each smear a profile of nuclear details was produced, also noting the type of cell mainly affected by the process; then the observers were asked to assess the degree of worry of HG disease for each smear i.e. whether the smear fell into group 1 borderline changes indicative of low-grade (normal, inflammatory, CIN1/HPV) disease (BL/LG) or group 2 difficult borderline smear, HG disease (CIN 2,3, invasive neoplasia or glandular neoplasia) cannot be excluded (BL/HG). Observer 1 selected a group of BL/HG with a PPV for HG disease of 38%, with observer 2 having a PPV of 50%; this compared with the overall laboratory HG disease PPV for borderline smears of 14%. Both observers found the most useful criterion to be the increase in nuclear:cytoplasmic ratio. Our results show that it is possible to separate a small group of borderline smears which should be classified as ,borderline/high grade lesion difficult to exclude' (BL/HG). Both observers had some success in arriving at this classification although their method of selecting out this group was quite different. [source] How predictive is a cervical smear suggesting glandular neoplasia?CYTOPATHOLOGY, Issue 2 2002M. E. MATHERS How predictive is a cervical smear suggesting glandular neoplasia The prevalence of endocervical adenocarcinoma and its precursors has increased, in part due to increased diagnostic awareness of these lesions. To date, limited information has been published regarding the predictive value of glandular abnormalities in cervical smears. This study details the histological follow up of 418 cervical smears showing glandular abnormality, reported in our department over a six year period from 1993 to 1998. Histological follow up was available for 395 of the 418 smears (94.50%). The overall positive predictive value (PPV) for this group of smears was 72.66% for either significant glandular or squamous pathology (at least low grade cervical glandular intraepithelial neoplasia or CIN2 on follow up biopsy), and 55.70% for significant glandular pathology alone. Examination of subcategories of abnormal glandular smear showed that the PPV increased with the degree of abnormality reported within the smears. [source] Comparison of the Medical Priority Dispatch System to an Out-of-hospital Patient Acuity ScoreACADEMIC EMERGENCY MEDICINE, Issue 9 2006Michael J. Feldman MD Abstract Background: Although the Medical Priority Dispatch System (MPDS) is widely used by emergency medical services (EMS) dispatchers to determine dispatch priority, there is little evidence that it reflects patient acuity. The Canadian Triage and Acuity Scale (CTAS) is a standard patient acuity scale widely used by Canadian emergency departments and EMS systems to prioritize patient care requirements. Objectives: To determine the relationship between MPDS dispatch priority and out-of-hospital CTAS. Methods: All emergency calls on a large urban EMS communications database for a one-year period were obtained. Duplicate calls, nonemergency transfers, and canceled calls were excluded. Sensitivity and specificity to detect high-acuity illness, as well as positive predictive value (PPV) and negative predictive value (NPV), were calculated for all protocols. Results: Of 197,882 calls, 102,582 met inclusion criteria. The overall sensitivity of MPDS was 68.2% (95% confidence interval [CI] = 67.8% to 68.5%), with a specificity of 66.2% (95% CI = 65.7% to 66.7%). The most sensitive protocol for detecting high acuity of illness was the breathing-problem protocol, with a sensitivity of 100.0% (95% CI = 99.9% to 100.0%), whereas the most specific protocol was the one for psychiatric problems, with a specificity of 98.1% (95% CI = 97.5% to 98.7%). The cardiac-arrest protocol had the highest PPV (92.6%, 95% CI = 90.3% to 94.3%), whereas the convulsions protocol had the highest NPV (85.9%, 95% CI = 84.5% to 87.2%). The best-performing protocol overall was the cardiac-arrest protocol, and the protocol with the overall poorest performance was the one for unknown problems. Sixteen of the 32 protocols performed no better than chance alone at identifying high-acuity patients. Conclusions: The Medical Priority Dispatch System exhibits at least moderate sensitivity and specificity for detecting high acuity of illness or injury. This performance analysis may be used to identify target protocols for future improvements. [source] Early motor repertoire is related to level of self-mobility in children with cerebral palsy at school ageDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 11 2009JANNEKE LM BRUGGINK MD Aim, To determine the predictive value of the early motor repertoire for the level of self-mobility in children with cerebral palsy (CP) at school age. Method, Video recordings were made at 11 to 17 weeks post-term of 37 preterm infants (20 males, 17 females) who later developed CP. The early motor repertoire was assessed by obtaining a motor optimality score. At 6 to 12 years, children were classified according to the Gross Motor Function Classification System (GMFCS). Results, Of 37 children (mean gestational age 29.1wks, SD 1.9; mean birthweight 1273g, SD 324), nine had unilateral and 28 had bilateral spastic CP. Twelve children were in GMFCS level I, three level II, 10 level III, four level IV, and eight level V. The absence of the age-adequate motor repertoire, a cramped motor repertoire, an abnormal kicking pattern, and a non-flat supine posture were associated with lower levels of self-mobility (,2 for trend test, p<0.05). Predictive for a low level of self-mobility was a cramped motor repertoire/non-flat supine posture (positive predictive values [PPV] 100%, negative predictive values [NPV] 54%). Predictive for a high level of self-mobility was a non-cramped repertoire/flat supine posture (PPV 80%, NPV 74%). Interpretation, Several aspects of the motor repertoire at 11 to 17 weeks post-term predicted the degree of functional limitations in children with CP at school age. [source] A multivariate logistic regression equation to screen for dysglycaemia: development and validationDIABETIC MEDICINE, Issue 5 2005B. P. Tabaei Abstract Aims To develop and validate an empirical equation to screen for dysglycaemia [impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and undiagnosed diabetes]. Methods A predictive equation was developed using multiple logistic regression analysis and data collected from 1032 Egyptian subjects with no history of diabetes. The equation incorporated age, sex, body mass index (BMI), post-prandial time (self-reported number of hours since last food or drink other than water), systolic blood pressure, high-density lipoprotein (HDL) cholesterol and random capillary plasma glucose as independent covariates for prediction of dysglycaemia based on fasting plasma glucose (FPG) , 6.1 mmol/l and/or plasma glucose 2 h after a 75-g oral glucose load (2-h PG) , 7.8 mmol/l. The equation was validated using a cross-validation procedure. Its performance was also compared with static plasma glucose cut-points for dysglycaemia screening. Results The predictive equation was calculated with the following logistic regression parameters: P = 1 + 1/(1 + e,X) = where X = ,8.3390 + 0.0214 (age in years) + 0.6764 (if female) + 0.0335 (BMI in kg/m2) + 0.0934 (post-prandial time in hours) + 0.0141 (systolic blood pressure in mmHg) , 0.0110 (HDL in mmol/l) + 0.0243 (random capillary plasma glucose in mmol/l). The cut-point for the prediction of dysglycaemia was defined as a probability , 0.38. The equation's sensitivity was 55%, specificity 90% and positive predictive value (PPV) 65%. When applied to a new sample, the equation's sensitivity was 53%, specificity 89% and PPV 63%. Conclusions This multivariate logistic equation improves on currently recommended methods of screening for dysglycaemia and can be easily implemented in a clinical setting using readily available clinical and non-fasting laboratory data and an inexpensive hand-held programmable calculator. [source] Assessing diabetic control , reliability of methods available in resource poor settingsDIABETIC MEDICINE, Issue 3 2002A. P. Rotchford Abstract Aims and methods To examine the reliability of random venous or capillary blood glucose testing, random urine glucose testing, and a current symptom history in predicting a high HbA1c in Type 2 diabetic patients taking oral hypoglycaemic agents in a poorly controlled rural African population. Results For a cut-off point for HbA1c of , 8%, for random venous plasma glucose of , 14 mmol/L (present in 47.2% of subjects), specificity was 97.1% (95% CI 85.1,99.9), sensitivity 56.8% (48.8,64.5) and positive predictive value (PPV) 98.9% (94.2,99.9). HbA1c, 8% is predicted by a random capillary blood glucose of 17 mmol/L (present in 28.4% of subjects) with specificity 100% (90.0,100.0), PPV 100% (93.7,100.0) and sensitivity of 34.3% (27.2,42.1). HbA1c, 8% is predicted by the presence of heavy glycosuria (, 55 mmol/L) (present in 35.6%) with specificity 94.1% (80.3,99.3), sensitivity of 41.9% (34.1,49.9) and PPV 97.1% (89.9,99.6). Polyuria/nocturia (present in 31.3%) was the only symptom found to be associated with poor control, with a specificity for predicting HbA1c of , 8% of 81.5% (61.9,93.7), PPV 89.1% (76.4,96.4) and sensitivity 30.6% (22.9,39.1). Conclusions Where resources are short, random glucose testing can be used to detect a significant proportion of those with the worst control with a high degree of specificity enabling primary care staff to modify treatment safely. Where facilities are limited capillary blood or urine testing with reagent strips, may be substituted for venous plasma testing in the laboratory. A symptom history was insufficient to replace biochemical testing, but where this is unavailable, urinary symptoms may be helpful. Diabet. Med. 19, 195,200 (2002) [source] A correlation study on diagnostic endoscopic ultrasound-guided fine-needle aspiration of lymph nodes with histological and clinical diagnoses, the UCLA Medical Center experienceDIAGNOSTIC CYTOPATHOLOGY, Issue 7 2008Bita V. Naini M.D. Abstract Endoscopic ultrasound guided (EUS) FNA procedure has two aspects, the endoscopic sampling and the FNA interpretation. The two aspects of the procedure are performed in two different disciplines; gastroenterology (EUS) and pathology (FNA). The aim of this study was to evaluate the concordance, sensitivity, specificity, positive predictive (PPV), and negative predictive values (NPV). Sixty-one EUS-FNA procedures of the lymph nodes were analyzed by correlating the FNA results with histological or clinical diagnoses. The lymph nodes were divided in five groups; mediastinal, gastrohepatic, peripancreatic, portal, and perirectal. The study showed a concordance of 92% in mediastinal, 80% in gastrohepatic, 81% in peripancreatic, 95% in portal, and 100% in perirectal lymph nodes with an overall sensitivity of 84%, specificity of 92%, PPV of 88%, and NPV of 89%. In conclusion, EUS-FNA offers an invaluable approach for diagnostic examination of the internal lymph nodes where percutaneous FNA is either difficult or impossible. impossible. Diagn. Cytopathol. 2008;36:460,466. © 2008 Wiley-Liss, Inc. [source] Comparison of p16INK4A and Hybrid Capture® 2 human papillomavirus testing as adjunctive tests in liquid-based gynecologic SurePathÔ preparationsDIAGNOSTIC CYTOPATHOLOGY, Issue 3 2008Aziza Nassar M.D., F.I.A.C. Abstract p16INK4a, cyclin-dependent kinase inhibitor, is functionally inactivated in many tumors, including cervical cancer. We compared p16INK4A immunocytochemical staining and Hybrid Capture® 2 (HCII) on SurePathÔ specimens using tissue biopsies (as the gold standard). Their utility in a spectrum of atypical and preneoplastic lesions, and their ability to accurately identify underlying lesions of CIN II or greater was assessed using biopsy follow-up data. One-hundred and seventeen residual SurePathÔ samples were collected: 43 atypical squamous cells of undetermined significance (ASCUS), 47 low-grade (LGSIL), and 27 high-grade (HGSIL) squamous intraepithelial lesions. Two slides were prepared from each sample; one stained with the SurePathÔ autocyte stain and one immunostained using the CINtecÔ p16INK4a Cytology Kit (Dakocytomation). High-risk HPV testing was performed using the HCII DNA test (Digene, Gaithersburg, MD). Available tissue biopsy follow-up data was retrieved. p16INK4a was positive in 32.6% (14/43) ASCUS, 46.8% (22/47) LGSIL, and 48.1% (13/27) HGSIL specimens. HCII DNA test was positive in 41.9% (18/43) ASCUS, 78.7% (37/47) LGSIL, and 96.3% (26/27) HGSIL samples. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of p16INK4a and HCII were: 58.7% and 89.8%, 58.6% and 34.6%, 69.2% and 72.1%, 47.2% and 64.3%, respectively. In patients with cervical biopsies, the PPV of HCII (92.3%) results for a biopsy with CINII/III was significantly higher than the PPV of p16INK4a (52%) (P = 0.001). Using liquid-based cytology specimens, HCII is a more sensitive test than p16INK4a for detection of abnormal cytology. HCII has a higher PPV than p16INK4a for identifying CIN II/III. Diagn. Cytopathol. 2008;36:142,148. © 2008 Wiley-Liss, Inc. [source] A prospective study of the diagnostic accuracy of cytological criteria in the FNAB diagnosis of breast papillomasDIAGNOSTIC CYTOPATHOLOGY, Issue 8 2007Andrew Field M.B., F.R.C.P.A. Abstract Seventy-four fine needle aspiration biopsies (FNAB) of breast were selected from the 133 cases with surgical biopsy follow up, from a total of 1,154 consecutive breast FNAB received in a 6-month-period. These 74 cases were reviewed and scored using all relevant cytological criteria for proliferative breast lesions used in our recent retrospective study, without reference to the original cytological and surgical biopsy diagnoses. Of the 42 criteria scored, 13 had a statistically significant association between the cytology score and the presence or absence of a papilloma (PAP), and the sensitivities, specificities and positive predictive values (PPV) of these individual criteria, or a combination of criteria, were derived. It was found that stellate and meshwork tissue fragments and papillary fragments were all highly specific (0.98) for the diagnosis of PAP, with meshwork fragments having the highest PPV (0.93). Stellate fragments (0.41) and papillary fragments (0.24) were less sensitive not only because they occurred less often, but also because they were present in smaller numbers. The presence of a proteinaceous background with macrophages and siderophages or a moderate to marked number of apocrine sheets were useful indicators only when coexisting with at least one of the above three features. Diagn. Cytopathol. 2007;35:465,475. © 2007 Wiley-Liss, Inc. [source] Clinical impact (cost-effectiveness) of qualifying atypical squamous cells of undeterminate significance (ASCUS) in cases favoring a reactive or dysplastic processDIAGNOSTIC CYTOPATHOLOGY, Issue 1 2003F.M. Carozzi Ph.D. Abstract The cost-effectiveness of qualifying ASCUS cases into two different subcategories, favoring a reactive (ASCUS-R) or dysplastic process (ASCUS-S), was evaluated at the Centro per lo Studio e la Prevenzione Oncologica of Florence in a prospective study. The study determined the positive predictive value (PPV) for histologically confirmed cervical intraepithelial neoplasia grade 2 (CIN2) or more (CIN>) severe lesion of the two ASCUS subgroups. ASCUS-S had a PPV (10.78%) comparable to low-grade squamous intraepithelial lesions (LSIL) (11.40%). For ASCUS-R cases, the recommendation of 6-mo repeat cytology prompting colposcopy in cases of persistent ASCUS or more severe cytology was also effective, as it selected a subgroup with a relatively high PPV (10.34%). The cost-effectiveness of a protocol based on ASCUS qualification was compared with two other possible options for nonqualified ASCUS cases: immediate colposcopy and colposcopy in persistent ASCUS at 6-mo repeat cytology.. The detection rate of CIN2> was substantially higher using ASCUS qualification (35.9 vs 14.8 or 17.1). The cost per ASCUS subject was ,24.99, 27.11, or 25.14 and that per CIN2> detected was ,697, 1,831 or 1,470 for the three options, respectively. The evidence that ASCUS detection option implies a higher detection rate of CIN2> and subsequently a lower cost per CIN2> detection must be considered with caution and deserves confirmation by other comparative studies. Diagn. Cytopathol. 2003;29:4,7. © 2003 Wiley-Liss, Inc. [source] Diagnostic value of needle aspiration cytology (NAC) in the assessment of palpable inguinal lymph nodes: A study of 210 casesDIAGNOSTIC CYTOPATHOLOGY, Issue 4 2003F.I.A.C., Raj K. Gupta M.D. Abstract The aim of this study was to evaluate the diagnostic value of needle aspiration cytology (NAC) in the assessment of palpable inguinal lymph nodes, which were analyzed in 210 cases. NAC in all the cases were performed by the conventional aspiration method and cytologic examination was done on site after staining smears with the Papanicolaou method. In addition, Diff-Quik-stained air-dried smears, Papanicolaou-stained fixed smears, and filter preparations from needle washings and hematoxylin-eosin-stained sections of cell blocks were studied. The NAC diagnosis was supported by examining cell blocks in 92/210 cases which showed a reliable histologic architecture; further support was also obtained with a tissue biopsy in 9/12 cases of inflammatory lesions, 7/7 cases with a suspicious diagnosis, 20/26 cases of melanomas, 15/15 cases of lymphomas, and/or a comparison with the primary tumor in other cases of metastatic tumors. Additionally, immunoperoxidase and/or histochemical stains were done. Twelve cases were diagnosed as inflammatory lesions and 88 cases were regarded as negative (normal cellular elements n = 40; reactive elements n = 48). In 58 cases a variety of metastatic tumors were diagnosed (melanoma n = 26; others n = 32) and in 15 cases a diagnosis of lymphoma was made. Seven cases were diagnosed as suspicious of malignancy and 30 cases were unsatisfactory due to scanty/acellular samples (despite 2,3 repeat samplings). However, in five of these malignant tumors were later found on a biopsy which was done due to a persistent and continued enlargement of lymph node(s). The sensitivity was 91.7%, specificity 98.2%, positive predictive value (PPV) 97.7.%, and negative predictive value (NPV) was 95.45%. Based on our study we feel that NAC as a first line of investigation is not only useful in the diagnosis of lesions in inguinal lymph nodes, but can also help in deciding on an appropriate management. Also, histologic architecture from cell blocks can be correlated with cytology and such material can be used for histochemical and immunomarker studies. Diagn. Cytopathol. 2003;28:175,180. © 2003 Wiley-Liss, Inc. [source] Validity of suspected alcohol and drug violations in aviation employeesADDICTION, Issue 10 2010Guohua Li ABSTRACT Aims In the United States, transportation employees who are suspected of using alcohol and drugs are subject to reasonable-cause testing. This study aims to assess the validity of suspected alcohol and drug violations in aviation employees. Methods Using reasonable-cause testing and random testing data from the Federal Aviation Administration for the years 1995,2005, we calculated the positive predictive value (PPV) and positive likelihood ratio (LR+) of suspected alcohol and drug violations. The true status of violations was based on testing results, with an alcohol violation being defined as a blood alcohol concentration of ,0.04 mg/dl and a drug violation as a test positive for marijuana, cocaine, amphetamines, phencyclidine or opiates. Results During the 11-year study period, a total of 2284 alcohol tests and 2015 drug tests were performed under the reasonable-cause testing program. The PPV was 37.7% [95% confidence interval (CI), 35.7,39.7%] for suspected alcohol violations and 12.6% (95% CI, 11.2,14.1%) for suspected drug violations. Random testing revealed an overall prevalence of 0.09% for alcohol violations and 0.6% for drug violations. The LR+ was 653.6 (95% CI, 581.7,734.3) for suspected alcohol violations and 22.5 (95% CI, 19.6,25.7) for suspected drug violations. Conclusion The discriminative power of reasonable-cause testing suggests that, despite its limited positive predictive value, physical and behavioral observation represents an efficient screening method for detecting alcohol and drug violations. The limited positive predictive value of reasonable-cause testing in aviation employees is due in part to the very low prevalence of alcohol and drug violations. [source] The Accuracy of Predicting Cardiac Arrest by Emergency Medical Services Dispatchers: The Calling Party EffectACADEMIC EMERGENCY MEDICINE, Issue 9 2003Alex G. Garza MD Abstract Objectives: To analyze the accuracy of paramedic emergency medical services (EMS) dispatchers in predicting cardiac arrest and to assess the effect of the caller party on dispatcher accuracy in an advanced life support, public utility model EMS system, with greater than 90,000 calls and greater than 60,000 transports per year. Methods: This was a retrospective analysis from January 1, 2000, through June 30, 2000, of 911 calls with dispatcher-assigned presumptive patient condition (PPC) or field diagnosis of cardiac arrest. Sensitivity and positive predictive value (PPV) of the PPC code for cardiac arrest by calling parties were calculated. Homogeneity of sensitivity and PPV of the PPC code for cardiac arrest by calling parties was studied with chi-square analysis. Relevant proportions, relative risk ratios, and associated 95% confidence intervals (95% CIs) were calculated. Student's t-test was used to compare quality assurance scores between calling parties. Results: There were 506 patients included in the study. Overall sensitivity for dispatcher-assigned PPC of cardiac arrest was 68.3% (95% CI = 63.3% to 73.0%) with a PPV of 65.0% (95% CI = 60.0% to 69.7%). There was a significant difference in the PPV for the EMS dispatcher diagnosis of cardiac arrest depending on the type of caller (,2= 17.34, p < 0.001). Conclusions: A higher level of medical training may improve dispatch accuracy for predicting cardiac arrest. The type of calling party influenced the PPV of dispatcher-assigned condition. [source] Validation of a brief screening instrument for the ascertainment of epilepsyEPILEPSIA, Issue 2 2010Ruth Ottman Summary Purpose:, To validate a brief screening instrument for identifying people with epilepsy in epidemiologic or genetic studies. Methods:, We designed a nine-question screening instrument for epilepsy and administered it by telephone to individuals with medical record,documented epilepsy (lifetime history of ,2 unprovoked seizures, n = 168) or isolated unprovoked seizure (n = 54), and individuals who were seizure-free on medical record review (n = 120), from a population-based study using Rochester Epidemiology Project resources. Interviewers were blinded to record-review findings. Results:, Sensitivity (the proportion of individuals who screened positive among affected individuals) was 96% for epilepsy and 87% for isolated unprovoked seizure. The false positive rate (FPR, the proportion who screened positive among seizure-free individuals) was 7%. The estimated positive predictive value (PPV) for epilepsy was 23%, assuming a lifetime prevalence of 2% in the population. Use of only a single question asking whether the subject had ever had epilepsy or a seizure disorder resulted in sensitivity 76%, FPR 0.8%, and estimated PPV 66%. Subjects with epilepsy were more likely to screen positive with this question if they were diagnosed after 1964 or continued to have seizures for at least 5 years after diagnosis. Discussion:, Given its high sensitivity, our instrument may be useful for the first stage of screening for epilepsy; however, the PPV of 23% suggests that only about one in four screen-positive individuals will be truly affected. Screening with a single question asking about epilepsy yields a higher PPV but lower sensitivity, and screen-positive subjects may be biased toward more severe epilepsy. [source] An Assessment of the Potential Value of Elevated Homocysteine in Predicting Alcohol-withdrawal SeizuresEPILEPSIA, Issue 5 2006Stefan Bleich Summary:,Purpose: Higher homocysteine levels were found in actively drinking patients with alcohol dependence. Recent studies have shown that high homocysteine levels are associated with alcohol-withdrawal seizures. The aim of the present study was to calculate the best predictive cutoff value of plasma homocysteine levels in actively drinking alcoholics (n = 88) with first-onset alcohol-withdrawal seizures. Methods: The present study included 88 alcohol-dependent patients of whom 18 patients had a first-onset withdrawal seizure. All patients were active drinkers and had an established diagnosis of alcohol dependence, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Sensitivity and specificity were calculated by using every homocysteine plasma level found in the study population as cut-off value. A Bayes theorem was used to calculate positive (PPV) and negative (NPV) predictive values for all cutoff values used. Results: The highest combined sensitivity and specificity was reached at a homocysteine plasma cutoff value of 23.9 ,M. Positive predictive values ranged from 0.23 to 0.745; the maximum was reached at a homocysteine plasma level of 41.7 ,M. Negative predictive values ranged from 0.50 to 0.935, with a maximum at a homocysteine plasma level of 15.8,M. Conclusions: Homocysteine levels above this cutoff value on admission are a useful screening tool to identify actively drinking patients at higher risk of alcohol-withdrawal seizures. This pilot study gives further hints that biologic markers may be helpful to predict patients at risk for first-onset alcohol-withdrawal seizures. [source] Plum pox virus (PPV) in FranceEPPO BULLETIN, Issue 2 2006Pierre Speich No abstract is available for this article. [source] Plum pox virus (PPV) in GermanyEPPO BULLETIN, Issue 2 2006W. Jarausch No abstract is available for this article. [source] Plum pox virus (PPV) in PolandEPPO BULLETIN, Issue 2 2006T. Malinowski No abstract is available for this article. [source] Plum pox virus (PPV) in RomaniaEPPO BULLETIN, Issue 2 2006M. Isac No abstract is available for this article. [source] Plum pox virus (PPV) in RussiaEPPO BULLETIN, Issue 2 2006Y. Prichodko No abstract is available for this article. [source] Epidemiology of sharka disease in FranceEPPO BULLETIN, Issue 2 2006G. Labonne Plum pox virus was first detected in France in the 1960s. Both PPV-D and PPV-M strains are present but epidemics related to the PPV-M strain detected in the late 1980s are the most problematic. The two PPV strains have unequal distributions in peach and apricot orchards and different prevalences. More than 20 different aphid species have been identified as vectors of PPV but most of them do not colonize Prunus species. Thus, aphids involved in the spread of PPV in orchards are essentially visiting aphids. The main sources of inoculum for the vectors are leaves and fruits of infected stone-fruit trees. Spontaneous, wild and ornamental Prunus species such as Prunus dulcis, P. spinosa or P. pissardii are susceptible to PPV isolates found in France but their role as a reservoir in sharka epidemics is probably negligible. The disease spreads rapidly in orchards but the rate of progression may vary according to the identity of the PPV strain and the Prunus species. Analysis of spatial patterns of disease has shown that secondary spread by aphids frequently occurs over short distances in the orchards (aggregated patterns) but also that dissemination at longer distances (of several hundred metres) is a common event. [source] Epidemiology of sharka disease in SpainEPPO BULLETIN, Issue 2 2006M. Cambra PPV was first detected in Spain in 1984 in Japanese plum (Prunus salicina Lindl) cv. Red Beaut and spread very quickly to other Japanese and European plums and apricot cultivars but left peach cultivars unaffected. In the years following the detection of PPV, the predominant aphid species visiting Prunus orchards in Mediterranean areas were Aphis gossypii followed by Aphis spiraecola, the latter being the main aphid species found at present. Both species are considered to be the main vectors of PPV in Spanish early Prunus growing areas. Spatial analysis of the spread of PPV-D in Japanese plum and apricot trees confirmed the lack of significant association between immediately adjacent trees. The observed spatial pattern of sharka suggests a lack of movement of PPV-viruliferous aphid vectors to immediately adjacent trees and indicates their preferential movement to trees several tree spaces away. PPV-D is the only type currently present in Spain, with the exception of a PPV-M outbreak that was detected in and successfully eradicated from Aragón in 2002. The short-distance spread of PPV-M infection occurred as far as 12 m along the rows of peach trees. However, PPV-D has not been observed to spread through peach cultivars, despite being grown in the vicinity of heavily infected plots of apricot or Japanese plum trees. [source] Control and monitoring: control of Plum pox virus in the United KingdomEPPO BULLETIN, Issue 2 2006R. A. Mumford Plum pox virus (PPV) was first identified in the United Kingdom in 1965. Despite a rigorous eradication policy, the disease spread quickly and established itself in all the main plum-growing areas in England. In 1975, the policy was changed from a blanket eradication campaign to one of containment; retaining statutory control of PPV on propagation material but allowing the industry to control the disease in orchards. As part of the current containment campaign, annual surveys are carried out on propagation material. These surveys show that the incidence of PPV in this material is very low and that only the D-strain is present. The precise situation regarding PPV incidence in commercial orchards is unknown. Given the low incidence in propagation material, it is likely that PPV is uncommon in actively managed orchards. However, some infected orchards probably do still exist, especially older, unmanaged or abandoned ones. Overall, the history of PPV control in the UK is one of unsuccessful eradication but successful containment. The UK experience demonstrates that given the right combination of strain and host, alongside a regular testing regime, it is possible to control PPV through the establishment of a regulated certification scheme and the supply of virus-free planting material. [source] Breeding for resistance: conventional breeding for Plum pox virus resistant apricots (Prunus armeniaca L.) in GreeceEPPO BULLETIN, Issue 2 2006I. Karayiannis A large apricot breeding programme has been conducted at NAGREF-Pomology Institute, Naoussa-Greece, for the control of sharka disease, since 1989. Ten apricot cultivars of North American origin: ,Stark Early Orange', ,Stella', ,NJA2', ,Sunglo', ,Veecot', ,Harlayne', ,Henderson', ,Goldrich', ,Orangered' and ,Early Blush', selected for their resistance to the highly virulent local strain of Plum pox virus (PPV)-M (Marcus), have been used as parents in crosses with quality cultivars, mainly with the local cv. Bebecou, from 1989 to 2003. Approximately 7000 hybrids have been created. Resistance to PPV was the main criterion of selection. Most hybrids have been subjected to artificial inoculation by PPV-M and examined for symptom expression for more than five years. Indexing to GF-305, as well as laboratory diagnostic tests, have been applied. The genetic analysis showed that: (1) 50% of the hybrids inherited resistance to PPV in the families where cvs. Stark Early Orange, NJA2, Sunglo, Veecot and Harlayne were used as a parent, and (2) 100% of the hybrids inherited resistance to PPV in the families where cv. Stella was one of the parents. Resistance to PPV appears to be under simple genetic control involving one gene locus. Promising apricot selections resistant to PPV-M have been released. [source] Conjugated Polymers: High-Resolution Scanning Near-Field Optical Lithography of Conjugated Polymers (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Mater. The fabrication of high-resolution nanostructures in both poly(p -phenylene vinylene), PPV, and a crosslinkable derivative of poly(9,9,-dioctylfluorene), F8, using scanning near-field optical lithography, is reported. The ability to draw complex, reproducible structures with 65000 pixels and lateral resolution below 60 nm (< ,/5) is demonstrated over areas up to 20 ,m × 20 ,m. Patterning on length-scales of this order is desirable for realizing applications both in organic nanoelectronics and nanophotonics. The technique is based on the site-selective insolubilization of a precursor polymer under exposure to the confined optical field present at the tip of an apertured near-field optical fiber probe. In the case of PPV, a leaving-group reaction is utilized to achieve insolubilization, whereas the polyfluorene is insolubilized using a photoacid initiator to create a crosslinked network in situ. For PPV, resolubilization of the features is observed at high exposure energies. This is not seen for the crosslinked F8 derivative, r-F8Ox, allowing us to pattern structures up to 200 nm in height. [source] High-Resolution Scanning Near-Field Optical Lithography of Conjugated PolymersADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Daniel Credgington The fabrication of high-resolution nanostructures in both poly(p -phenylene vinylene), PPV, and a crosslinkable derivative of poly(9,9,-dioctylfluorene), F8, using scanning near-field optical lithography, is reported. The ability to draw complex, reproducible structures with 65000 pixels and lateral resolution below 60 nm (< ,/5) is demonstrated over areas up to 20 ,m × 20 ,m. Patterning on length-scales of this order is desirable for realizing applications both in organic nanoelectronics and nanophotonics. The technique is based on the site-selective insolubilization of a precursor polymer under exposure to the confined optical field present at the tip of an apertured near-field optical fiber probe. In the case of PPV, a leaving-group reaction is utilized to achieve insolubilization, whereas the polyfluorene is insolubilized using a photoacid initiator to create a crosslinked network in situ. For PPV, resolubilization of the features is observed at high exposure energies. This is not seen for the crosslinked F8 derivative, r-F8Ox, allowing us to pattern structures up to 200 nm in height. [source] Enhanced Optical Properties and Opaline Self-Assembly of PPV Encapsulated in Mesoporous Silica SpheresADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Timothy L. Kelly Abstract A new poly(p -phenylenevinylene) (PPV) composite material has been developed by the incorporation of insoluble PPV polymer chains in the pores of monodisperse mesoporous silica spheres through an ion-exchange and in situ polymerization method. The polymer distribution within the resultant colloidal particles is characterized by electron microscopy, energy dispersive X-ray microanalysis, powder X-ray diffraction, and nitrogen adsorption. It was found that the polymer was selectively incorporated into the mesopores of the silica host and was well distributed throughout the body of the particles. This confinement of the polymer influences the optical properties of the composite; these were examined by UV,vis and fluorescence spectroscopy and time-correlated single-photon counting. The results show a material that exhibits an extremely high fluorescence quantum yield (approaching 85%), and an improved resistance to oxidative photobleaching compared to PPV. These enhanced optical properties are further complemented by the overall processability of the colloidal material. In marked contrast to the insolubility of PPV, the material can be processed as a stable colloidal dispersion, and the individual composite spheres can be self-assembled into opaline films using the vertical deposition method. The bandgap of the opal can be engineered to overlap with the emission band of the polymer, which has significant ramifications for lasing. [source] Design of Multilayered Nanostructures and Donor,Acceptor Interfaces in Solution-Processed Thin-Film Organic Solar Cells,ADVANCED FUNCTIONAL MATERIALS, Issue 10 2008Hiroaki Benten Abstract Multilayered polymer thin-film solar cells have been fabricated by wet processes such as spin-coating and layer-by-layer deposition. Hole- and electron-transporting layers were prepared by spin-coating with poly(3,4-ethylenedioxythiophene) oxidized with poly(4-styrenesulfonate) (PEDOT:PSS) and fullerene (C60), respectively. The light-harvesting layer of poly-(p -phenylenevinylene) (PPV) was fabricated by layer-by-layer deposition of the PPV precursor cation and poly(sodium 4-styrenesulfonate) (PSS). The layer-by-layer technique enables us to control the layer thickness with nanometer precision and select the interfacial material at the donor,acceptor heterojunction. Optimizing the layered nanostructures, we obtained the best-performance device with a triple-layered structure of PEDOT:PSS|PPV|C60, where the thickness of the PPV layer was 11,nm, comparable to the diffusion length of the PPV singlet exciton. The external quantum efficiency spectrum was maximum (ca. 20%) around the absorption peak of PPV and the internal quantum efficiency was estimated to be as high as ca. 50% from a saturated photocurrent at a reverse bias of ,3,V. The power conversion efficiency of the triple-layer solar cell was 0.26% under AM1.5G simulated solar illumination with 100,mW,cm,2 in air. 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