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Adequate Sensitivity (adequate + sensitivity)
Selected AbstractsA national retinal screening programme for diabetes in ScotlandDIABETIC MEDICINE, Issue 12 2003G. P. Leese Abstract The Health Technology Board Scotland (HTBS) have issued recommendations for eye screening in patients with diabetes. These are based on evidence-based clinical studies. Evidence-based studies do not answer all the practical issues, and some conclusions have thus been extrapolated from the known evidence base. Other factors such as patient issues, organizational issues and cost effectiveness have also been incorporated into the recommendations. HTBS recommend single-field digital retinal photography. Retinal photography best addresses the issues of adequate sensitivity and accountable quality assurance. Non-mydriatic photography is recommended, followed by immediate use of dilating eye drops if it is unsuccessful, followed by slit-lamp examination if both of these approaches fail. An independent grading scheme has been established, which is similar to the ,Global', and compatible with the National Screening Committee (NSC) grading scheme. The rationale for these recommendations, and debate behind some of the decisions, is laid out in this article. [source] Electroanalytical Determination of Promethazine Hydrochloride in Pharmaceutical Formulations on Highly Boron-Doped Diamond Electrodes Using Square-Wave Adsorptive VoltammetryELECTROANALYSIS, Issue 18 2008Francisco, Wirley Abstract The electrochemical oxidation of promethazine hydrochloride was made on highly boron-doped diamond electrodes. Cyclic voltammetry experiments showed that the oxidation mechanisms involved the formation of an adsorbed product that is more readily oxidized, producing a new peak with lower potential values whose intensity can be increased by applying the accumulation potential for given times. The parameters were optimized and the highest current intensities were obtained by applying +0.78,V for 30 seconds. The square-wave adsorptive voltammetry results obtained in BR buffer showed two well-defined peaks, dependent on the pH and on the voltammetric parameters. The best responses were obtained at pH,4.0, frequency of 50,s,1, step of 2,mV, and amplitude of 50,mV. Under these conditions, linear responses were obtained for concentrations from 5.96×10,7 to 4.76×10,6,mol L,1, and calculated detection limits of 2.66×10,8,mol L,1 (8.51,,g L,1) for peak 1 and of 4.61×10,8,mol L,1 (14.77,,g L,1) for peak 2. The precision and accuracy were evaluated by repeatability and reproducibility experiments, which yielded values of less than 5.00% for both voltammetric peaks. The applicability of this procedure was tested on commercial formulations of promethazine hydrochloride by observing the stability, specificity, recovery and precision of the procedure in complex samples. All results obtained were compared to recommended procedure by British Pharmacopeia. The voltammetric results indicate that the proposed procedure is stable and sensitive, with good reproducibility even when the accumulation steps involve short times. It is therefore very suitable for the development of the electroanalytical procedure, providing adequate sensitivity and a reliable method. [source] Faecal screening of colorectal cancerINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 3 2008A. Loganayagam Summary Aims:, Screening and prevention of colorectal cancer (CRC) is a public health priority. Recent progress in understanding the biology of CRC has lead to possible new approaches to screening. In particular, assay of faecal molecular markers represents a promising non-invasive approach to screening, with improved safety, accuracy and patient compliance. Methods:, MEDLINE/PubMed searches were used to identify key articles relating to faecal-based screening with secondary review of cited publications. Results:, Faecal markers of CRC can be broadly divided into DNA based and non-DNA based. Conclusions:, Faecal occult blood testing for CRC screening has been advocated for decades for its non-invasiveness and low cost. It has exhibited a 15,33% decrease in mortality, despite drawbacks with sensitivity and compliance. Other non-DNA markers have the adequate sensitivity for inflammatory lesions but do not have the required specificity for screening average-risk populations. Faecal DNA testing has the potential to enhance the performance characteristics of stool testing. Because of molecular heterogeneity of cancer, no single DNA marker has yielded adequate sensitivity. Analysis of several combinations of markers in studies have produced high detection rates of both CRC and advanced adenomas in selected patient groups. However, the currently available markers, both non-DNA and DNA, have not yet been validated in large-scale studies screening average -risk population nor have they so far shown the necessary sensitivity and specificity required for large-scale screening programmes. Another major drawback with the DNA-based markers is the cost-effectiveness. Issues regarding implementation and compliance remain unanswered. These critical problems have to be rectified before these techniques can be recommended for large-scale CRC screening. [source] Electrophoretic analysis of urinary proteins in diabetic adolescentsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2001George Koliakos Abstract Pathological changes in the urine sodium dodecyl sulphate gel electrophoresis (SDS PAGE) patterns often precede the occurrence of any sign of renal involvement in diabetes. However, data concerning the most frequent SDS PAGE pattern of the urine in early stages of type I diabetes mellitus are controversial. In the present study an SDS PAGE technique has been used that provides an adequate sensitivity for the detection of the abnormal pattern. Urinary proteins have been analyzed by SDS PAGE in twenty two diabetic adolescents and twenty four age matched controls. Albumin concentration, and N acetyl-beta-D-glucosaminidase (NAG) activity were also measured in the same samples. There was no significant difference in urine albumin concentration and NAG activity between diabetic children and controls. However twelve patients showed an electrophoretic pattern characteristic for glomerulopathy, two had a pattern indicating tubular dysfunction and another two patients had a mixed pattern. Among the twenty four controls only three showed abnormal electrophoretic patterns. The results support the view that early stages of diabetic nephropathy may involve both glomerular and tubular dysfunction. However the exact clinical and prognostic significance of the information provided by SDS PAGE analysis remains to be elucidated. J. Clin. Lab. Anal. 15:178,183, 2001. © 2001 Wiley-Liss, Inc. [source] IgG classification of anti-PF4/heparin antibodies to identify patients with heparin-induced thrombocytopenia during mechanical circulatory supportJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2 2007S. SCHENK Summary., Commercial immunoassays frequently detect anti-PF4/heparin antibodies during mechanical circulatory support (MCS), but only a small minority of patients develops heparin-induced thrombocytopenia (HIT). Whereas platelet functional tests can distinguish between platelet-activating and non-platelet-activating antibodies, commercial PF4-dependent immunoassays do not. Between 2003 and 2004, 113 patients were placed on MCS. Blood samples were obtained on postimplant day 5,7 for analyses by antibody assays and the functional heparin-induced platelet activation (HIPA) assay. Three distinct groups of patient sera were identified: platelet-activating anti-PF4/heparin antibodies (n = 10), non-platelet-activating anti-PF4/heparin antibodies (n = 53), and anti-PF4/heparin antibody negative (n = 50). Patients with platelet-activating antibodies had the highest risk for thromboembolic events (P < 0.005), whereas those with non-platelet-activating antibodies did not differ from antibody negative patients (P = 0.369). The enzyme-immunoassay and column agglutination assays, which cover all immunoglobulin classes, demonstrated adequate sensitivity and negative predictive value; yet, both lacked specificity with respect to the platelet-activating antibodies. If all antibody positive patients were further classified by an IgG-specific anti-PF4/heparin enzyme-immuno assay, specificity for platelet-activating antibodies increased. Whereas IgG-specific optical density (OD) values below 1.0 were likely for non-platelet-activating anti-PF4/heparin antibodies, higher values were progressively predictive for pathogenic platelet activation. The probability of the development of clinical HIT also increased steeply. In conclusion, platelet-activating anti-PF4/heparin antibodies are relatively common (about 9%) in patients on MCS and are associated with significantly higher thrombotic event rates. Low IgG-specific OD values (< 1.0) in the enzyme-immunoassay indicate low likelihood for the presence of platelet-activating antibodies. These results justify further validation so that anticoagulation during MCS becomes safer and adequate. [source] Mouse diaphragm assay for detection of antibodies against botulinum toxin type BMOVEMENT DISORDERS, Issue 12 2005Dirk Dressler MD Abstract With the advent of a commercial preparation of botulinum toxin type B (BT-B) for treatment of cervical dystonia detection of antibodies against BT-B (BT-B-AB) becomes necessary. For this purpose, we carried out a mouse diaphragm assay (MDA) by continuous measurement of the twitch force of a mouse hemidiaphragm preparation elicited by electric stimulation of its phrenic nerve. After exposing the preparation to BT-B 3 ng/ml the time to half-maximal twitch force reduction (paralysis time [PT]) was 69 ± 4 min (n = 25). Addition of sera from patients with antibodies against BT-A produced a PT of 68 ± 5 min (n = 24), whereas addition of sera from controls with antibodies against tetanus toxoid produced a PT of 67 ± 6 min (n = 30). When defined amounts of BT-B-AB were added to the MDA, PT was prolonged. This prolongation was correlated closely to the amount of BT-B-AB added, thus producing a calibration curve. The threshold for BT-B-AB detection was 0.4 mU/ml. When sera from 7 patients (4 women, 3 men; age 50.6 ± 14.2 years) with cervical dystonia (Toronto Western Spasmodic Torticollis Rating Scale score, 18.9 ± 2.9) and complete secondary failure of BT-B therapy (NeuroBloc; Elan Pharmaceuticals, Shannon, Ireland; 12,229 ± 2,601 MU/injection series, 1.86 ± 0.69 injection series before complete secondary therapy failure; 100.4 ± 15.8 days between injection series with normal therapeutic effect) were tested, BT-B-AB titers of more than 10 mU/ml were found in all of them. The MDA can be used to measure neutralizing BT-B-AB titers quantitatively and with adequate sensitivity and specificity. Further studies are necessary to understand the role of intermediate BT-B-AB titers in partial BT-B therapy failure. © 2005 Movement Disorder Society [source] Evaluation of Selective Lymph Node Sampling in the Node-Negative Neck,THE LARYNGOSCOPE, Issue 6 2002Richard O. Wein MD Abstract Objective To determine whether intraoperative selective lymph node sampling before neck dissection in the node-negative (N0) neck accurately reflects the disease content of the neck and can be used to assist in treatment selection. Study Design A prospective clinical study at a university medical center. Methods Over a 2-year period, 36 patients with head and neck squamous cell carcinoma scheduled to undergo 41 elective neck dissections were enrolled. At the initiation of the neck dissection, biopsy of the "most suspicious" lymph node within the tumor's primary nodal drainage basin was performed, and the specimen was measured and sent for frozen-section evaluation. The results of lymph node sampling were compared with the final histopathologic interpretation of the resected primary and neck dissection. Results Of the 41 N0 necks, 29% (12 of 41) were positive for occult metastases. Results of selective lymph node biopsy correlated with the results of neck dissection in 34 of 41 specimens (83%). The specificity and positive predictive value of node sampling were both 100%. The proportion of cases with a positive neck dissection with a positive sampled node (sensitivity) was 42% (5 of 12). Conclusion The results of selective lymph node biopsy with frozen-section analysis in the N0 neck, as defined in the current study, did not reflect a technique with adequate sensitivity to alter intraoperative treatment strategy. [source] Immune Function Tests for Hazard Identification: A Paradigm Shift in Drug DevelopmentBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2006Elizabeth R. Gore The purpose of the more stringent approach to immunotoxicology testing was to better identify unintended immunosuppression; however, the requirement was met with much discussion and debate. At the center of the discussion was an attempt to reconcile opposing regulatory directives from agencies outside of Europe that adhere to a more selective, weight-of-evidence approach to functional evaluations. Uncertainty over the predictive value of the recommended immune function tests relative to conventional toxicology parameters prompted an investigation by the International Committee on Harmonization (ICH). The results of a preliminary, industry-wide survey indicated that only a low percentage of pharmaceuticals adversely affect immune function without alterations to standard toxicology parameters. Expected ICH guidelines will ultimately determine to what extent and for what purpose immune function tests will be conducted. In the meantime, optimization of the recommended immune function tests is ongoing. The T-cell dependent antibody response (TDAR) by either conventional Sheep Red Blood Cell (SRBC) plaque assay or by the modified ELISA method using either SRBC or keyhole limpet hemocyanin (KLH) as antigen is being extensively evaluated to determine best practices and procedures for preclinical immunotoxicity evaluations. This review addresses some aspects of the debate concerning the appropriateness of immune function tests for hazard identification, along with recommendations for optimizing TDAR methodology to ensure adequate sensitivity and predictability in risk assessments for immunotoxicity. [source] Diagnosing bipolar disorder in trauma exposed primary care patientsBIPOLAR DISORDERS, Issue 4 2007Ruth Elaine Graves Objectives:, Bipolar disorder (BD) is often under-recognized in non-psychiatric settings, especially in African Americans. The Mood Disorder Questionnaire (MDQ) is a screening instrument proposed to show adequate sensitivity and specificity for bipolar spectrum disorders. The current study is an examination of the usefulness of this instrument in a trauma exposed subgroup of mainly African American patients attending primary care clinics. Methods:, The sample is a part of a larger study exploring traumatic stress exposure and psychopathology. Consenting patients in 3 academically affiliated primary care clinics were asked to complete the MDQ. Ninety percent of the participants were African American. Diagnostic performance was determined in a trauma exposed subgroup by employing the Structured Clinical Interview for DSM-IV (SCID) as a gold standard. Results:, Of the total group of 579 participants, 178 (30.7%) screened positive for BD along with 77 (33.7%) of the 228 trauma exposed subjects who were SCID interviewed. Only 13 (27%) of the MDQ positives met SCID criteria for BD and were true positives. The sensitivity was 61.9% and the specificity was 69%, with a positive predictive value of 16.8% and a negative predictive value of 94.7%. Conclusions:, The MDQ was found to have low specificity in a predominately African American group of trauma exposed patients attending primary care. [source] | ||||||||||