High Sensitivity (high + sensitivity)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of High Sensitivity

  • very high sensitivity

  • Terms modified by High Sensitivity

  • high sensitivity c-reactive protein

  • Selected Abstracts

    Rapid (partial) prescreening of cervical smears: the quality control method of choice?

    CYTOPATHOLOGY, Issue 4 2002
    Rapid rescreening of all negative and inadequate smears is the quality control method of choice in the UK. The sensitivity of primary screening of laboratory and individual screeners are major indicators of screening quality and are dependent on the number of false negative smears found by rapid screening for their calculation. High sensitivity may indicate good quality primary screening or poor quality rapid review. Quantifiably high quality rapid rescreening is essential if these sensitivity figures are to be meaningful. A 12-month study was undertaken in routine practice using the prescreening mode to ascertain the sensitivity of rapid (partial) screening in our department . The final results of smears were compared with those of rapid prescreening. The calculated sensitivity ranged from 92,54% for high-grade abnormalities and 75,33% for all grades, revealing a wide range of performance between individual prescreeners. Rapid prescreening can identify individuals best suited to rapid screening in routine practice. By using these prescreeners only, the sensitivity of cervical screening could be raised. Rapid (partial) prescreening should be considered as the quality control method of choice. [source]

    Ecdysteroid synthesis and imaginal disc development in the midge Chironomus riparius as biomarkers for endocrine effects of tributyltin

    Torsten Hahn
    Abstract Acute effects of the endocrine disruptor bis (tri- n -butyltin) oxide (TBTO) on molting-hormone biosynthesis and imaginaldisc development were investigated in larvae of the midge Chironomus riparius (Meigen). Ecdysteroid synthesis was measured by 24-h incubation of molting-hormone-synthesizing tissues (prothoracic glands) in vitro with or without the addition of TBTO. The amount of ecdysteroids produced was analyzed by radioimmunoassay. Developmental effects in vivo were investigated by determining the developmental phase of the genital imaginal discs before and after a 48-h exposure to TBTO in water. Sex-specific effects were found with both endpoints. Ecdysteroid synthesis was significantly reduced (analysis of variance [ANOVA], p , 0.005) in female larvae at all concentrations (TBTO-Sn at 50, 500, and 5,000 ng/L), whereas a significant elevation of the biosynthesis rate occurred in male larvae in the 500-ng/L treatment (ANOVA, p , 0.05). In vivo experiments with development of the genital imaginal disc within a 48-h exposure period revealed a significantly slower development in female larvae and a significantly faster development in male larvae (contingency tables, p , 0.001) at all concentrations tested (TBTO-Sn at 10, 50, 200, and 1,000 ng/L). These results partly coincided with the in vitro effects on molting-hormone synthesis. The 48-h median lethal concentration (LC50) was 25 ,g/L (20,30 ,g/L 95% confidence intervals). The combination of in vitro and in vivo methods has proven to be a useful approach for the detection of endocrine effects of TBTO in C. riparius at levels 2,000-fold below the LC50 value. High sensitivity and short test duration suggest that chironomids may have potential as freshwater sentinel organisms for endocrine-disrupting chemicals. [source]

    High sensitivity of chemiluminescent methodology for detection of clonal CDR3 sequences in patients with acute lymphoblastic leukemia

    E. Leal
    Abstract Detection of minimal residual disease (MRD) in patients with B-cell acute lymphoblastic leukemia (B-ALL) has been achieved using several radioactive labelling methodologies; however, limited information exists about the use of chemiluminescent labelling. Although many malignant disorders are related to cytogenetic alterations, there is not a consistent chromosomal translocation that could serve as a tumour marker for the monitoring of MRD. ALL are derived from B-lymphocytes in 80% of cases. In the early stages of their maturation, the immunoglobulin heavy chain genes (IgH) undergo rearrangements among their V, D, and J segments, giving rise to the Complementary Determining Regions (CDR). Among these, CDR3 is considered unique for each lymphocyte and used as a tumour-specific marker in B-ALL patients. In this study, the CDR3 was labelled with digoxigenin and used as a patient-specific probe to test its sensitivity for further detection of MRD. Fourteen pretreatment samples of bone marrow (BM) or peripheral blood (PB) from B-ALL patients were included. Tumour-specific probes were designed from each clonal product by elimination of the consensus sequences. Ten digoxigenin-labelled probes were hybridized with a mixture of their respective clonal DNA and the polyclonal product from a normal healthy donor, in serial dilutions from 1:1 up to 1:107. A sensitivity range of 1:103,1:106 was obtained, with an average of 1:105. Crossed tests performed in four patients, showed right probe specificity in all cases. We propose that the design of allele-specific probes with chemiluminescent labelling, represents a reliable, sure and sensitive alternative methodology for MRD detection in patients with B-cell lymphoproliferative disorders. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Screening for mild cognitive impairment: a systematic review

    Jane A. Lonie
    Abstract Objective Patients with mild cognitive impairment account for a significant number of referrals to old age psychiatry services and specialist memory clinics. The cognitive evaluation of such patients is commonly restricted to brief dementia screens, with no consideration to their suitability for assessing MCI. Here, we review the utility of such cognitive screens for MCI and provide an overview of validated instruments. Methods We identified papers published after Petersen and colleagues 1999 MCI criteria (Petersen et al., 1999) and examining face-to-face cognitive screening for MCI from publication databases using combinations of the search terms ,mild cognitive impairment' and ,cognitive screening'. We also combined the former search with the names of 39 screening tests recently identified in a relevant review (Cullen et al., 2007). Results Fifteen cognitive screening instruments were identified, 11 cover a restricted range of cognitive domains. High sensitivity and specificity for MCI relative to healthy controls were reported for two comprehensive and two noncomprehensive screening instruments, adequate test-retest and inter-rater reliability for only one of these. With the exception of three studies, sample sizes were universally small (i.e. n,,,100), and prognostic values were reported for only two of the identified 15 screening measures. Sensitivities of the full domain measures were universally high, but information about their specificity against psychiatric and non-progressive neurological conditions and predictive validity is lacking. Conclusion Several cognitive screening instruments afford the clinician the ability to detect MCI, early AD, and in some cases non-AD dementia, but they cannot currently be used to make reliable inferences about the course and eventual outcome of MCI. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Author's Response to Professor Reiber's second letter concerning our article: High sensitivity of free lambda and free kappa light chains for the detection of intrathecal immunoglobulin synthesis in cerebrospinal fluid

    Borros Arneth
    No abstract is available for this article. [source]

    High sensitivity of free lambda and free kappa light chains for detection of intrathecal immunoglobulin synthesis in cerebrospinal fluid

    B. Arneth
    Background,,, So far, an inflammation of the central nervous system (CNS) is diagnosed by immunoglobulin measurement in cerebrospinal fluid (CSF) and serum as well as by determination of the oligoclonal bands. With the free kappa and lambda light chains, new markers to diagnose intrathecal synthesis are available. Methods,,, In addition to routine diagnostic tests and the assessment of standard parameters, free immunoglobulin light chains were measured in the CSF of patients with neurological disorders. Results,,, A significant agreement was found between an increase in free kappa light chain CSF serum quotients and results of the currently widely applied method of oligoclonal band measurement for the detection of intrathecal immunoglobulin synthesis. A sensitivity of 95% and 100% specificity for free kappa light chain concentrations at a cut-off of 0.41 mg/l was determined for free kappa light chains compared with oligoclonal bands. However, the free lambda light chains in 20 out of the 110 investigated samples were characterized by inconsistent behaviour. These otherwise unremarkable samples yielded increased CSF quotients, leading to the assumption that free lambda light chains represent a highly sensitive measure of intrathecal immunologlobulin synthesis. Thirteen of the 20 samples described above were obtained from patients with cerebral infarction, 4 samples derived from patients with cerebral paresis (primarily facial paresis), one sample was from a patient with multisystem atrophy and two were obtained from patients with migraine and neuralgia. Conclusion,,, These findings suggest that the high sensitivity of lambda light chains for the detection intrathecal immunoglobulin synthesis may be of benefit in establishing clinical diagnoses. [source]

    Triage Patients with Suspected Pulmonary Embolism in the Emergency Department Using a Portable Ultrasound Device

    ECHOCARDIOGRAPHY, Issue 5 2008
    Nicolas Mansencal M.D.
    The diagnosis of pulmonary embolism (PE) is difficult, despite validated diagnostic models. We sought to determine the value of a portable ultrasound device for triage of patients with suspected PE referred to the emergency department, using simplified echo criteria. We prospectively studied 103 consecutive patients with suspected PE, referred to our emergency department. After D-dimer screening, 76 patients were prospectively enrolled in this ultrasound study and underwent helical chest tomography, transthoracic echocardiography, and venous ultrasonography. Among patients with PE (n = 31), a right ventricular dilation was detected in 17 patients (55%), a direct visualization of clot in the lower limbs was present in 18 patients (58%), and 8 patients (26%) had both right ventricular dilation and deep venous thrombosis. The sensitivity and specificity of a combined ultrasound strategy using echocardiography and venous ultrasonography were respectively 87% (95% confidence interval 74% to 96%), and 69% (95% confidence interval 53% to 82%). The sensitivity of this combined strategy was significantly improved as compared to venous ultrasonography alone (P = 0.01) or echocardiography alone (P = 0.005). In patients with dyspnea or with high clinical probability of PE, this combined strategy was particularly relevant with high sensitivities (respectively 94% and 100%). Echocardiography combined with venous ultrasonography using a portable ultrasound device is a reliable method for screening patients with suspected PE referred to an emergency department, especially in patients with dyspnea or with high clinical probability. [source]

    Development of an oxide semiconductor thick film gas sensor for the detection of total volatile organic compounds

    Masahiro Kadosaki
    Abstract Since the amendment of the Building Standards Law in 2003, the installation of ventilators is compulsory in newly built houses, because many persons suffer from indoor air pollution caused by volatile organic compounds (VOCs). The goal of this research is to develop a gas sensor that can monitor the total VOC (TVOC) gases indoors and then to control the ventilator efficiently using the sensor. In order to develop a sensor that detects TVOC, the responses of four oxide semiconductor materials to 37 different VOC gases were studied. These materials showed small responses to halogenated and aliphatic hydrocarbon gases. As a result of improving the response to these gases, among four metal oxides examined, SnO2 and WO3 showed high sensitivities by the addition of Pd and Pt. The sensing properties of SnO2 for halogenated hydrocarbon gases were greatly improved by the addition of 0.5 wt% Pd. The sensing properties of SnO2 for aliphatic hydrocarbon gases were improved by the addition of 0.7 wt% Pt. In addition, a sensor element with the addition of both platinum and palladium, that is, Pt (0.5 wt%)-Pd (0.5 wt%)-SnO2, showed a large response to many of the VOC gases examined. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(10): 34,41, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10190 [source]

    Low-Distortion Holographic Data Storage Media Using Free-Radical Ring-Opening Polymerization

    Kyongsik Choi
    Abstract Holographic data storage, due to its potential to increase capacity beyond one terabyte per disk, is tipped to be one of the next generation optical data storage technologies. Polymer-based systems are leading candidates due to their high dynamic range, high sensitivities, and flexible and easy production, and yet polymerization-shrinkage-induced distortion is a major hurdle for its reliable use. In this paper, a new free radical polymerization holographic recording medium, based on low shrink cyclic allylic sulfides (LS-CASs) ring-opening monomers, is proposed and demonstrated. The percentage of volume shrinkage is measured to be 0.02%, with refractive index (RI) contrast of (1.01,±,0.5),×,10,3. The measured volume shrinkage is, to the authors' best knowledge, the best reported so far in the literature. Other parameters such as sensitivity, dynamic range, and dark reaction properties are also measured, where the values can be optimized with high RI functional groups without sacrificing the low shrinkage. [source]

    Muscle ultrasound in neuromuscular disorders

    MUSCLE AND NERVE, Issue 6 2008
    Sigrid Pillen MD
    Abstract Muscle ultrasound is a useful tool in the diagnosis of neuromuscular disorders, as these disorders result in muscle atrophy and intramuscular fibrosis and fatty infiltration, which can be visualized with ultrasound. Several prospective studies have reported high sensitivities and specificities in the detection of neuromuscular disorders. Although not investigated in large series of patients, different neuromuscular disorders tend to show specific changes on muscle ultrasound, which can be helpful in differential diagnosis. For example, Duchenne muscular dystrophy results in a severe, homogeneous increase of muscle echo intensity with normal muscle thickness, whereas spinal muscular atrophy shows an inhomogeneous increase of echo intensity with severe atrophy. A major advantage of muscle ultrasound, compared to other imaging techniques, is its ability to visualize muscle movements, such as muscle contractions and fasciculations. This study reviews the possibilities and limitations of ultrasound in muscle imaging and its value as a diagnostic tool in neuromuscular disorders. Muscle Nerve, 2008 [source]

    Diagnostic value of electromyography and muscle biopsy in arthrogryposis multiplex congenita

    ANNALS OF NEUROLOGY, Issue 6 2003
    Peter B. Kang MD
    Arthrogryposis multiplex congenita (AMC), a clinical syndrome characterized by multiple congenital joint contractures, frequently is caused by lesions in the peripheral nervous system. Two standard tests for the evaluation of the motor unit are nerve conduction studies/electromyography (NCS/EMG) and muscle biopsy. We reviewed the diagnostic value of these two studies in the evaluation of AMC over a 23-year period, analyzing 38 patients with AMC who had NCS/EMG, muscle biopsy, or both. Final diagnoses were classified as neurogenic (8 patients), myopathic (10 patients), "other" (12 patients), or unknown (8 patients). Neither test alone had consistently high sensitivities, positive predictive values, or specificities. However, when NCS/EMG and muscle biopsy were concordant for neurogenic or myopathic findings, they were more accurate than either test alone, especially for neurogenic diseases. Test results were most commonly discordant in patients with "other" or unknown diagnoses. These findings suggest that when the clinical evaluation indicates a specific syndromic, developmental, or exogenous cause, NCS/EMG and muscle biopsy are not helpful and may not need to be performed. When the history, examination, and genetic evaluation are unrevealing, NCS/EMG and muscle biopsy together provide valuable diagnostic information. [source]

    Second-order Scattering and Frequency Doubling Scattering Spectra of Thallium(III)-Methotrexate System and Its Analytical Application

    Cun-Xian XI
    Abstract In pH 4.9 Britton-Robinson buffer solution, methotrexate (MTX) reacted with thallium(III) to form a 3:1 chelate. This resulted in great enhancement of second-order scattering (SOS) spectra and frequency doubling scattering (FDS) spectra and appearance of new SOS and FDS spectra. Their maximum wavelengths were located at 520 and 390 nm, respectively. The increments of scattering intensities (,I) were directly proportional to the concentrations of MTX in the ranges of 0.022,2.0 µg·mL,1 (SOS method) and 0.008,2.5 µg·mL,1 (FDS method). The methods exhibited high sensitivities. The detection limits for MTX were 7.4 ng·mL,1 (SOS method) and 2.3 ng·mL,1 (FDS method), respectively. The optimum conditions of the reaction, the influencing factors and the effects of coexisting substances were investigated. A highly sensitive, simple and fast method for the determination of MTX has been developed. The method can be applied satisfactorily to the determination of MTX in human serum samples. In this work, the charge distribution of MTX was calculated by a CNDO quantum chemistry method. In addition, the reaction mechanism was discussed. [source]

    Evaluation of 2 self-administered questionnaires to ascertain dermatitis among metal workers and its relation with exposure to metalworking fluids

    CONTACT DERMATITIS, Issue 6 2007
    Berna Van Wendel de Joode
    We performed an exploratory study to evaluate 2 self-administered questionnaires assessing hand dermatitis and investigate a possible exposure,response relationship between dermal exposure to semi-synthetic metalworking fluids (SMWF) and dermatitis. In a cross-sectional survey on dermatitis, a symptom-based questionnaire and a picture-based skin screening list were applied in 80 SMWF-exposed workers and 67 referents. To evaluate the accuracy of the questionnaires, 47 subjects were examined by a dermatologist. Dermal exposure levels to SMWF were assessed on hands, forearms, and face with a observational method that was validated using a fluorescent tracer method. The symptom-based questionnaire had a relatively high sensitivity (0.86) but moderate specificity (0.64), and the skin screening list had a low sensitivity (0.36) and a relatively high specificity (0.84). The skin screening list seemed to represent the more severe cases of dermatitis and showed a significant relation with exposure for dermatitis on hands, forearms, or face. In epidemiological surveys where workers are not seen by a dermatologist, the skin screening list seems to be more appropriate to detect cases of dermatitis, as its higher specificity results in less false positives. Alternatively, it would be preferable applying the symptom-based questionnaire; workers with symptoms should be seen by a dermatologist to identify false positives. [source]

    Flow cytometry antibody screening using pooled red cells,

    CYTOMETRY, Issue 2 2010
    Dong Il Won
    Abstract Background: For red cell alloantibody screening, the column agglutination technique (CAT) is used extensively, and flow cytometry (FC) screening has recently been demonstrated to be accurate, rapid, and cost effective. We attempted to determine whether the high sensitivity of FC allows pooling of screening red cells, which is generally not an acceptable technique in CAT. Methods: For FC screening, a commercial two-cell screening panel was utilized for the preparation of individual cells (CSi), as well as pooled cells diluted 1 in 2 (CSp), and 1 in 3 (CS1/3). Another panel was pooled from 120 randomly selected group O donors (RSp). Results: Comparing the endpoint titrations of serial dilutions, CS1/3 was found to be one dilution, on the average, less sensitive than CSi. In 33 CAT-positive patient samples, the sensitivities of CSi and CSp did not differ significantly without polyethylene glycol (PEG) (30/33, 26/33, respectively, P = 0.125), although they did differ significantly with PEG (32/33, 25/33, respectively, P = 0.016). The percentages of reactive cells among the total cells from RSp were roughly proportional to the relevant antigen frequencies of the local donors. Conclusions: A trend toward reduced sensitivity was observed using pooled red cells, even via FC. Pooled cells from randomly selected group O donors may be employed as another method by which the characteristics of known antibodies might be assessed. © 2009 Clinical Cytometry Society [source]

    Development of micropost force sensor array with culture experiments for determination of cell traction forces

    CYTOSKELETON, Issue 7 2007
    Bin Li
    Abstract Cell traction forces (CTFs) are critical for cell motility and cell shape maintenance. As such, they play a fundamental role in many biological processes such as angiogenesis, embryogenesis, inflammation, and wound healing. To determine CTFs at the sub-cellular level with high sensitivity, we have developed high density micropost force sensor array (MFSA), which consists of an array of vertically standing poly(dimethylsiloxane) (PDMS) microposts, 2 ,m in diameter and 6 ,m in height, with a center-to-center distance of 4 ,m. In combination with new image analysis algorithms, the MFSA can achieve a spatial resolution of 40 nm and a force sensitivity of 0.5 nN. Culture experiments with various types of cells showed that this MFSA technology can effectively determine CTFs of cells with different sizes and traction force magnitudes. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source]

    Panic Disorder Severity Scale: Reliability and validity of the Turkish version,,

    E. Serap Monkul M.D.
    Abstract We assessed the reliability and validity of the Turkish version of the seven-item Panic Disorder Severity Scale (PDSS). We recruited 174 subjects, including 104 with current DSM-IV panic disorder with (n = 76) or without(n = 28)agoraphobia, 14 with a major depressive episode, 24 with a non-panic anxiety disorder, and 32 healthy controls. Assessment instruments were Panic Disorder Severity Scale, Panic and Agoraphobia Scale, both the observer-rated (P&Ao) and self-rating (P&Asr); Clinical Global Impression Scale (CGI); Hamilton Anxiety Scale, and Beck Depression Inventory. We repeated the measures for a group of panic disorder patients (n = 51) after 4 weeks to assess test,retest reliability. The internal consistency (Cronbach's ,) of the PDSS was .92,94. The inter-rater correlation coefficient was .79. The test,retest correlation coefficient after 4 weeks was .63. In discriminant validity analyses, the highest correlation for PDSS was with P&Ao, P&Asr (r=.87 and .87, respectively) and CGI (r=.76) and the lowest with Beck Depression Inventory (r=.29). The cut-off point was six/seven, associated with high sensitivity (99%) and specificity (98%). This study confirmed the objectivity, reliability and validity of the Turkish version of the PDSS. Depression and Anxiety 00:000,000, 2004. © 2004 Wiley-Liss, Inc. [source]

    What drives cell morphogenesis: A look inside the vertebrate photoreceptor

    Breandán Kennedy
    Abstract Vision mediating photoreceptor cells are specialized light-sensitive neurons in the outer layer of the vertebrate retina. The human retina contains approximately 130 million of such photoreceptors, which enable images of the external environment to be captured at high resolution and high sensitivity. Rod and cone photoreceptor subtypes are further specialized for sensing light in low and high illumination, respectively. To enable visual function, these photoreceptors have developed elaborate morphological domains for the detection of light (outer segments), for changing cell shape (inner segments), and for communication with neighboring retinal neurons (synaptic terminals). Furthermore, rod and cone subtypes feature unique morphological variations of these specialized characteristics. Here, we review the major aspects of vertebrate photoreceptor morphology and key genetic mechanisms that drive their formation. These mechanisms are necessary for cell differentiation as well as function. Their defects lead to cell death. Developmental Dynamics 238:2115,2138, 2009. © 2009 Wiley-Liss, Inc. [source]

    Do we agree about when patients are psychotic?

    J. Nielsen
    Objective:, To investigate into the use of the term ,psychotic' as defined by ICD-10 or by the concept of impaired reality testing, among psychiatric staff members. Method:, Questionnaire investigation using 11 short case vignettes. Results:, Responses were received from 266 psychiatric staff members: psychiatrists, nursing staff and psychologists. When using ICD-10, patients were identified as psychotic with a sensitivity ranging from 90% to 55%. Specificity ranged from 60% to 75%. According to the concept of impaired reality testing, all three groups showed a sensitivity of about 60%, whereas specificity ranged from 65% to 50%. The combined use of the terms correlated significantly with responses regarding indication for legal detention for psychiatrists and nursing staff. Conclusion:, In identifying a patient as ,psychotic' a broad concept of impaired reality testing was widely used particularly in cases with legal issues. Psychotic symptoms, however, were identified with high sensitivity and specificity. [source]

    The value of the Rydel-Seiffer tuning fork as a predictor of diabetic polyneuropathy compared with a neurothesiometer

    DIABETIC MEDICINE, Issue 6 2004
    T. Kästenbauer
    Abstract Aims The aim of the study was to investigate the predictive value of the Rydel-Seiffer tuning fork for detecting diabetic neuropathy and to compare it with an electronic neurothesiometer. Methods In 2022 consecutive diabetic subjects, peripheral polyneuropathy was diagnosed by vibration perception threshold (VPT) at the tip of both great toes using a 128-Hz tuning fork and a neurothesiometer, by simple bedside tests and by the presence of neuropathic symptoms. These evaluations were further combined to diagnose peripheral nerve dysfunction (abnormal bedside tests) and symptomatic neuropathy. VPT was also measured in 175 non-diabetic control subjects to define normal values. Results VPT was normal in 1917 subjects and abnormal in 105 (5.2%) patients when measured by the tuning fork. Patients with an abnormal vibration test were significantly (P < 0.0001) older than subjects with a normal vibration sense, while diabetes duration and HbA1c of the former were also significantly elevated. The same was true for the percentages of an abnormal 10-g monofilament test (66.7% vs. 7.2%, P < 0.0001) and a missing Achilles' tendon reflex (68.6% vs. 24.8%, P < 0.0001). Finally, the VPT measured by the neurothesiometer was 2.5 times higher in patients with an abnormal tuning fork test (32.0 ± 9.8 vs. 12.5 ± 6.4 V, P < 0.0001). The plot of the difference of both methods against their mean yielded a good agreement of the two VPT measurements, and the tuning fork had a high sensitivity and positive predictive value for the diagnosis of abnormal bedside tests and for symptomatic neuropathy. Conclusion The tuning fork reliably detected peripheral neuropathy in comparison with the neurothesiometer. A tuning fork is a useful screening test for diabetic neuropathy. [source]

    Review of validation studies of the Edinburgh Postnatal Depression Scale

    Malin Eberhard-Gran
    Objective: ,To review validation studies of the Edinburgh Postnatal Depression Scale (EPDS). Method: ,A systematic search was performed in Medline and the Science Citation Index Expanded (ISI) from the period 1987,2000. For sensitivity and specificity of the EPDS presented in each study, 95% confidence intervals were estimated. Positive and negative predictive values were estimated assuming prevalences of postpartum depression ranging from 5% to 20%. Results: ,Eighteen validation studies were identified. The study design varied between studies. The sensitivity and specificity estimates also varied: 65,100% and 49,100%, respectively. The confidence intervals were estimated to be wide. Our estimates suggest a lower positive predictive value in a normal population than in the validation study samples. Conclusion: ,Most studies show a high sensitivity of the EPDS. Because of the differences in study design and large confidence intervals, uncertainty remains regarding the comparability between the sensitivity and specificity estimates of the different EPDS versions. [source]

    Analysis of micrometastatic disease in histologically negative lymph nodes of patients with adenocarcinoma of the distal esophagus or gastric cardia

    C. J. Buskens
    SUMMARY., Lymphatic dissemination is the most important prognostic factor in patients with esophageal carcinoma. However, the clinical significance of lymph node micrometastases is still debated due to contradictory results. The aim of the present study was to identify the incidence of potentially relevant micrometastatic disease in patients with histologically node-negative esophageal adenocarcinoma and to analyze the sensitivity and specificity of three different immunohistochemical assays. From a consecutive series of 79 patients who underwent a transthoracic resection with extended 2-field lymphadenectomy, all 20 patients with pN0 esophageal adenocarcinoma were included in this study. A total of 578 lymph nodes were examined for the presence of micrometastases by immunohistochemical analysis with the antibodies Ber-EP4, AE1/AE3 and CAM 5.2. Lymph node micrometastases were detected in five of the 20 patients (25%). They were identified in 16 of the 578 lymph nodes examined (2.8%) and most frequently detected with the Ber-EP4 and AE1/AE3 antibody (sensitivity 95% and 79% respectively). In 114 of the 559 negative lymph nodes (20.4%), positive single cells were found that did not demonstrate malignant characteristics. These false-positive cells were more frequently found with the AE1/AE3 staining (specificity of the Ber-Ep4 and AE1/AE3 antibody 94% and 84% respectively). The presence of nodal micrometastases was associated with the development of locoregional recurrences (P=0.01), distant metastases (P=0.01), and a reduced overall survival (log rank test, P=0.009). For the detection of clinically relevant micrometastatic disease in patients operated upon for adenocarcinoma of the distal esophagus or gastric cardia, Ber-EP4 is the antibody of first choice because of its high sensitivity and specificity. Immunohistochemically detected micrometastases in histologically negative lymph nodes have potential prognostic significance and are associated with a high incidence of both locoregional and systemic recurrence. Therefore, this technique has the potential to refine the staging system for esophageal cancer and to help identify patients who will not be cured by surgery alone. [source]

    Viable Myocardium: How Much Is Enough?

    ECHOCARDIOGRAPHY, Issue 1 2005
    A Comparison of Viability by Comparative Imaging Techniques to Assess the Quantity, Functionality of Ischemic Myocardium
    Left ventricular systolic dysfunction is mainly a result of coronary artery disease (CAD). Decrease in myocardial contractility results as a response to a chronic hypoperfusion state that produces a change in cardiac myocyte metabolism, resulting in a perfusion-contraction mismatch in which function is sacrificed for survival. If revascularization is performed in a timely fashion, metabolism can be restored leading to recovery of function. Through the use of noninvasive imaging modalities, assessing myocardial viability can be easily performed and will aid in selecting those patients who will benefit from revascularization. Viable myocardium can be identified by nuclear modalities that have a high sensitivity but a lower specificity, such as thallium-201 single photon emission computed tomography and positron emission tomography (PET); or by the use of dobutamine stress echocardiogram (DSE), which has a decreased sensitivity but a better specificity. A modality that is increasingly being used with an overall good sensitivity and specificity is contrast-enhanced magnetic resonance imaging. The purpose of this review is to explore the amount of myocardial viability that is relevant to pursue revascularization, since as myocardial function improves there is a decrease in morbidity and mortality from heart failure and arrhythmias. [source]

    A Novel Polycatechol/Ordered Mesoporous Carbon Composite Film Modified Electrode and Its Electrocatalytic Application

    ELECTROANALYSIS, Issue 15 2010
    Jing Bai
    Abstract Polycatechol (PCC) was prepared by electropolymerizing catechol (CC) on the surface of an ordered mesoporous carbon (OMC) modified electrode for the first time. Scanning electron microscopy (SEM) and cyclic voltammetry (CV) were used to characterize the structure and electrochemical behaviors of PCC/OMC nanocomposite film. Compared with the bare GC and OMC/GC electrodes, the PCC/OMC/GC electrode exhibits a good electrocatalysis toward the oxidation of NADH at 0.0,V with a high sensitivity (8.7 mA/mM). These make PCC/OMC/GC electrode a promising candidate for stable and efficient electrochemical sensors for the detection of NADH. [source]

    Lable-Free Electrochemical DNA Sensor Based on Gold Nanoparticles/Poly(neutral red) Modified Electrode

    ELECTROANALYSIS, Issue 6 2010
    Keying Zhang
    Abstract We present a new strategy for the label-free electrochemical detection of DNA hybridization based on gold nanoparticles (AuNPs)/poly(neutral red) (PNR) modified electrode. Probe oligonucledotides with thiol groups at the 5-end were covalently linked onto the surface of AuNPs/PNR modified electrode via S-Au binding. The hybridization event was monitored by using differential pulse voltammetry (DPV) upon hybridization generates electrochemical changes at the PNR-solution interface. A significant decrease in the peak current was observed upon hybridization of probe with complementary target ssDNA, whereas no obvious change was observed with noncomplementary target ssDNA. And the DNA sensor also showed a high selectivity for detecting one-mismatched and three-mismatched target ssDNA and a high sensitivity for detecting complementary target ssDNA, the detection limit is 4.2×10,12,M for complementary target ssDNA. In addition, the DNA biosensor showed an excellent reproducibility and stability under the DNA-hybridization conditions. [source]

    Electrogenerated Chemiluminescence Sensor Based on Tris(2,2,-bipyridine)ruthenium(II)-Immobilized Natural Clay and Ionic Liquid

    ELECTROANALYSIS, Issue 2 2010
    Ping Jiang
    Abstract A novel electrogenerated chemiluminescence (ECL) sensor based on natural clay and ionic liquid was fabricated. Tris(2,2,-bipyridine)ruthenium(II) (Ru(bpy)32+) was immobilized on natural clay surface through simple adsorption. An ECL sensor was prepared by mixing Ru(bpy)32+ -incorporated clay, graphite powder and an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) as the binder. The electrochemical behavior and ECL of the immobilized Ru(bpy)32+ was investigated. It was observed that the ECL of immobilized Ru(bpy)32+ was activated by the ionic liquid. The proposed ECL sensor showed high sensitivity to tri- n -propylamine (TPrA) and the detection limit was found to be 20,pM. In addition, the ECL sensor displayed good stability for TPrA detection and long-term storage stability. [source]

    Ammonia Gas Sensor Using Polypyrrole-Coated TiO2/ZnO Nanofibers

    ELECTROANALYSIS, Issue 12 2009
    Ying Wang
    Abstract Highly porous polypyrrole (PPy)-coated TiO2/ZnO nanofibrous mat has been successfully synthesized. The core TiO2/ZnO nanofibers have an average diameter of ca. 100,nm and the shell of ultrathin PPy layer has a thickness of ca. 7,nm. The NH3 gas sensor using the as-prepared material exhibited a fast response over a wide dynamic range and high sensitivity with a detection limit of 60,ppb (S/N=3). Compared to conventional pristine PPy film, the improved performance in NH3 detection can be attributed to the free access of NH3 to PPy and a minimized gas diffusion resistance through the ultrathin PPy layer. [source]

    A Biomimetic Potentiometric Sensor Using Molecularly Imprinted Polymer for the Cetirizine Assay in Tablets and Biological Fluids

    ELECTROANALYSIS, Issue 18 2008
    Mehran Javanbakht
    Abstract Despite the increasing number of applications of molecularly imprinted polymers (MIPs) in analytical chemistry, the construction of a biomimetic potentiometric sensor remains still challenging. In this work, a biomimetic potentiometric sensor, based on a non-covalent imprinted polymer was fabricated for the recognition and determination of cetirizine. The MIP was synthesized by precipitation polymerization, using cetirizine dihydrochloride as a template molecule, methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross linking agent. The sensor showed high selectivity and a sensitive response to the template in aqueous system. The MIP-modified electrode exhibited Nernstian response (28.0±0.9 mV/decade) in a wide concentration range of 1.0×10,6 to 1.0×10,2 M with a lower detection limit of 7.0×10,7 M. The electrode has response time of ca. 20,s, high performance, high sensitivity, and good long term stability (more than 5,months). The method was satisfactory and used to the cetirizine assay in tablets and biological fluids. [source]

    Dendritic Silver/Silicon Dioxide Nanocomposite Modified Electrodes for Electrochemical Sensing of Hydrogen Peroxide

    ELECTROANALYSIS, Issue 17 2008
    Peixi Yuan
    Abstract A novel biosensor for hydrogen peroxide was prepared by immobilizing horseradish peroxidase (HPR) on newly synthesized dendritic silver/silicon dioxide nanocomposites, which were coated on a glassy carbon electrode. The modified electrode was characterized with XPS, SEM, and electrochemical methods. This biosensor showed a very fast amperometric response to hydrogen peroxide with a linear range from 0.7 to 120,,M, a limit of detection of 0.05,,M and a sensitivity of 1.02,mA mM,1 cm,2. The Michaelis-Menten constant of the immobilized HRP was estimated to be 0.21,mM, indicating a high affinity of the HRP to H2O2 without loss of enzymatic activity. The preparation of the proposed biosensor was convenient, and it showed high sensitivity and good stability. [source]

    Fabrication, Characterization, and Application of ,Sandwich-Type' Electrode Based on Single-Walled Carbon Nanotubes and Room Temperature Ionic Liquid

    ELECTROANALYSIS, Issue 17 2008
    Xuzhi Zhang
    Abstract The much-enhanced electrochemical responses of potassium ferricyanide and methylene blue (MB) were firstly explored at the glassy carbon electrode modified with single-walled carbon nanotubes (SWNT/GCE), indicating the distinct electrochemical activity of SWNTs towards electroactive molecules. A hydrophobic room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), was used as electrode modification material, which presented wide electrochemical windows, proton permeation and selective extraction ability. In consideration with the advantages of SWNTs and RTIL in detecting target molecules (TMs), a novel strategy of ,sandwich,type' electrode was established with TMs confined by RTIL between the SWNT/GCE and the RTIL membrane. The strategy was used for electrochemical detection of ascorbic acid (AA) and dopamine (DA), and detection limits of 400 and 80 fmol could be obtained, respectively. The selective detection of DA in the presence of high amount of AA could also be realized. This protocol presented many attractive advantages towards voltammetric detection of TMs, such as low sample demand, low cost, high sensitivity, and good stability. [source]

    Synthesis and Characterization of MWNTs/Au NPs/HS(CH2)6Fc Nanocomposite: Application to Electrochemical Determination of Ascorbic Acid

    ELECTROANALYSIS, Issue 16 2008
    Jian-Ding Qiu
    Abstract In this article, a detailed electrochemical study of a novel 6-ferrocenylhexanethiol (HS(CH2)6Fc) self-assembled multiwalled carbon nanotubes-Au nanoparticles (MWNTs/Au NPs) composite film was demonstrated. MWNTs/Au NPs were prepared by one-step in situ synthesis using linear polyethyleneimine (PEI) as bifunctionalizing agent. HS(CH2)6Fc, which acted as the redox mediator, was self-assembled to MWNTs/Au NPs via Au-S bond. Transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), Fourier transformed infrared absorption spectroscopy (FT-IR), UV-visible absorption spectroscopy, and cyclic voltammetry were used to characterize the properties of the MWNTs/Au NPs/HS(CH2)6Fc nanocomposite. The preparation of the nanocomposite was very simple and effectively prevented the leakage of the HS(CH2)6Fc mediator during measurements. The electrooxidation of AA could be catalyzed by Fc/Fc+ couple as a mediator and had a higher electrochemical response due to the unique performance of MWNTs/Au NPs. The nanocomposite modified electrode exhibited excellent catalytic efficiency, high sensitivity, good stability, fast response (within 3,s) and low detection limit toward the oxidation of AA at a lower potential. [source]