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PubMed2005

Novel quality control methods in conjunction with chemometrics (multivariate analysis) for detecting honey authenticity.

The importance of honey has been recently upgraded because of its nutrient and therapeutic effect. The adulteration of honey increased exponentially in terms of both geographic and/or botanical origin. Therefore, the need has arisen for more effective quality control methods aiming at detecting adulteration. Various novel, fast, and accurate methods like AAS, HPLC, GC-MS, ES-MS, TLC, HPAED-PAD, NMR, FT-Raman, and NIR have enriched the arsenal of analytical chemist in this direction. However, apart from these novel methods, the application of multivariate analysis and, in particular, PCA, CLA, and CA, proved to be extremely useful for grouping and detecting honey of various origins. Mineral and trace element analysis were repeatedly shown to be a very effective means for the classification purposes of honey of various origins (geographical and botanical).

Amino Acids↗

PubMed1981

[Quality control of computer-assisted arrhythmia monitoring].

In the management of coronary care patients, continuous ECG analysis is best performed by a computerized monitoring system. For more than 2 years all the patients in this CCU have been monitored by the 78220 Hewlett-Packard arrhythmia monitoring system. As a quality control of the system the data of 15,068 alarm situations in 300 patients were first analyzed: the specificity of the system varied from 3% to 83% according to type and severity of arrhythmias. To evaluate the sensitivity of the system the amount of VES registered by Holter monitoring was then compared with the analysis by computerized monitoring during the same period of time: in a total of over 10,000 VES in 14 patients the sensitivity was 90%. Although the personnel of a CCU still have to deal with a large number of false positive alarms, a computerized arrhythmia monitoring system offers a higher degree of security for the patient than conventional monitoring.

Arrhythmias, Cardiac↗

PubMed2006

A pragmatic and readily implemented quality control strategy for HPLC-MS and GC-MS-based metabonomic analysis.

Metabonomic/metabolomic studies can involve the analysis of large numbers of samples for the detection of biomarkers and confidence in the analytical data, generated by methods such as GC and HPLC-MS, requires active measures on the part of the analyst. However, quality control for complex multi-component samples such as biofluids, where many of the components of interest in the sample are unknown prior to analysis, poses significant problems. Here the repeat analysis of a pooled sample throughout the run, thereby enabling the analysis to be monitored and controlled using targeted inspection of the data and pattern recognition, is advocated as a pragmatic solution to this problem.

Biomarkers↗

PubMedDate not supplied

Decomposition and quality control considerations in biological work with fecapentaene preparations.

Solutions of synthetic fecapentaene 12 (FP-12) intended for carcinogenicity studies were found to decompose extremely rapidly during customary dosage procedures. Apparent half-lives as short as 15 min were observed. While rates and even the qualitative course of decomposition were surprisingly variable in replicate experiments, high concentration and exposure to air were confirmed to be especially important destabilizing influences. The results suggested a primary role for a radical decomposition mechanism in the presence of atmospheric oxygen. Consistent with this hypothesis, FP-12 solutions were significantly stabilized by the radical chain-breaking antioxidant vitamin E. On the other hand, dithiothreitol greatly destabilized FP-12, presumably because of its nucleophilicity. The diacetyl diester of FP-12 was more soluble than the parent diol, but its decomposition rates in the presence and absence of vitamin E were similar to those of unesterified FP-12. Ultraviolet irradiation of an all-trans-FP-12 solution decreased its concentration by 70% in 0.5 min. The mutagenicities of the decomposition/isomerization products of FP-12, as studied in Salmonella typhimurium tester strain TA 100, ranged from negligible to comparable with all-trans-FP-12 itself. It is concluded that unchecked decomposition of fecapentaene preparations can profoundly affect biological tests therewith. While this can be largely controlled through the use of rigorous precautions, including protection from air, light, nucleophiles, and acids as well as selection of the lowest concentration compatible with the application at hand, the data argue strongly for inclusion of appropriate quality control measures in all future dosing operations to prove that the biological activity reported is that of the fecapentaene itself rather than that of a decomposed dosing solution.

Chromatography, High Pressure Liquid↗

PubMed2005

Quality-controlled education in epileptology: experiences from Europe and possible developments for other regions.

As a consequence of the political system shift in Eastern Europe in the early 1990s, the new International League Against Epilepsy (ILAE) Commission on European Affairs (CEA) had to face the task of ensuring an equally good quality of epilepsy care across the whole region. A high standard of epileptologic education being the most important precondition for that, the decision was taken to make quality-controlled education a first priority. To reach this aim, an "European Epilepsy Academy" (Eurepa) was founded in 1996. Its activities comprise organization of its own educational courses, certification of other educational courses, responsibility for education at European Congresses, training of trainers in epilepsy (now 45 trainers from 27 countries), adoption of a curriculum to become a certified European epileptologist, establishment of a multinational educational network, and a "Website Academy" as a forum for discussion. In the first two years of its activity, the Academy received financial support from the ILAE (money generated by the European Congresses) but has since been self-supporting, with income from membership fees, participation fees at courses, and moderate support from pharmaceutical companies. The interest in the Academy is high, especially in those parts of Europe where epileptology was until recently not well developed. This should encourage other regional ILAE commissions to implement similar strategies, even if different regional structures will require variable regional approaches. Thus, in regions with long distances, it may be useful to include methods of distant learning and other specific features.

Academies and Institutes↗

PubMed2006

A note on the use of outlier criteria in Ontario laboratory quality control schemes.

OBJECTIVES: This paper examines the pitfalls that arise when an outlier is assessed using a criterion based on a fixed multiple of the standard deviation rather than an established statistical test. Although the former approach is statistically invalid, it is the favored method for identifying outliers in Ontario laboratory quality control protocols. DESIGN AND METHODS: Computer simulations are used to calculate the probability of a false positive result (classifying a valid observation as an outlier) when outlier criteria based on fixed multiples of the standard deviation are applied to samples containing no outliers. RESULTS: The estimated probability of a false positive result is tabulated over various sample sizes. Outlier criteria based on fixed multiples of the standard deviation are shown to be highly inefficient. CONCLUSIONS: This work presents arguments for discontinuing the widespread practice of using outlier criteria based on fixed multiples of the standard deviation to identify outliers in univariate samples.

Clinical Chemistry Tests↗

PubMed1980

Supplementary quality controls of plasma fractions for manufactures and consumers.

As a consequence of the increasing use of plasma fractions, there is an ever-growing abundance of such preparations. These preparations may be divided into three main groups: clotting factors, immunoglobulins, and plasma protein solutions. Frequency of component-induced side-effects are inversely proportional to those components' quality. Pharmacopoeas presently require only the following quality criteria for most plasma preparations: declaration of sort and concentration of the active component and stabilizers, sterility, and the absence of pyrogens. Of great importance is the origin of the raw material and the methods used to harvest the plasma, as well as the molecular condition of the proteins. While we can assume that presently-available preparations meet minimum requirements, it can be demonstrated that similar preparations can in no case be considered equivalent when immunoelectrophoresis, ultracentrifugation and gel filtration are used as additional quality control tests. Especially immunoelectrophoresis and gel filtration are tests easily available to the clinician to help him detect and thus select the optical product.

Antibodies↗

PubMed1997

[Important points concerning quality control of blood products under the product liability law].

Two years have passed since the product liability(PL) law took effect in our country on July 1, 1995. At the start, we were uneasy about such things as an increase in lawsuits, the rise of medical care costs and the concealment of medical information. However, no-one has brought an action concerning blood products so far under the PL law. In terms of quality control of blood products, regular inspection of various instruments, reagents and manuals is the fundamental rule. Moreover, in order to ensure blood products of good quality, it is very important to select blood donors on the basis of physical examination and questionnaires on their medical condition, not to mention a range of screening tests to detect viral and bacterial infection. Since the first HIV infection through blood derived from an HIV-seronegative donor was reported in our country, it is especially desirable to improve measures for detecting HIV in window period blood for HIV antibody. There is also a problem concerning the irradiation of blood products to prevent PT-GVHD. We expect the PL law to provide a higher degree of safety of blood transfusion; however, it is also necessary to make proper use of blood products and to take the right measures in the event of adverse transfusion reaction, so as to raise the safety of blood transfusion.

Blood Component Transfusion↗

PubMed1977

Quality control in the microbiological serum folate assay.

Low values obtained in the microbiological assay of serum folate are often due to the presence of antibiotics in the test serum. The assay has been modified to permit consistent recognition of the presence and extent of such contamination. Other assay variables have been investigated and a quality control system devised which rapidly identifies the presence of inconsistencies in any one assay batch. The system further allows for the reporting of some clinically useful results from an imperfect assay batch thus reducing the necessity for reassay of some test sera.

Anti-Bacterial Agents↗

PubMed1992

Interpretive criteria and quality control parameters for testing susceptibility of Haemophilus influenzae to enoxacin, ofloxacin, and temafloxacin.

Haemophilus influenzae isolates were uniformly susceptible to enoxacin, ofloxacin, and temafloxacin. Zone diameter and MIC interpretive criteria were proposed to define susceptible populations so that mutants with diminished susceptibility might be detected when and if they appear in clinical specimens. Additional collaborative quality control studies defined MIC and zone size limits for tests with H. influenzae ATCC 49247.

Anti-Infective Agents↗

PubMed2005

[Quality control of pathological examination in colorectal cancer].

Pathological assessment of colorectal cancer resection specimens is the most significant prognostic indicator. This includes determination of TNM stage, tumour type and grade, status of resection margins, extramural vascular and perineural invasion, and molecular features such as defects in the mismatch repair system. The pathological assessment contributes significantly to the quality control of surgery and preoperative staging. Reporting should be standardized by using DSPAC's registration scheme for colorectal carcinomas.

Biological Specimen Banks↗

PubMed2006

Use of the Coccidioides posadasii Deltachs5 strain for quality control in the ACCUPROBE culture identification test for Coccidioides immitis.

Coccidioides posadasii Deltachs5 is a strain that is excluded from the select agent list. Sixteen assays using test reagents from three different ACCUPROBE Coccidioides immitis culture identification test lots had an average of 132,998 relative light units (RLU), which is well beyond the 50,000-RLU positive cutoff value for the test. Coccidioides posadasii Deltachs5 is a satisfactory quality control isolate in the ACCUPROBE culture identification test for Coccidioides immitis.

Animals↗

PubMed1983

[Direct and indirect parameters of free thyroxine. I. Method, quality control and in vitro experiments on storage of samples and effect of drugs].

The clinical applicability of direct FT4 determinations by the radioimmunoassays ImmoPhase, GammaCoat, Liquisol, Amerlex and LisoPhase is tested in comparison to the FT4 index and the T4/TBG ratio. Part I of this study deals with technical aspects concerning quality control as well as with in-vitro experiments concerning storage of samples and interference of drugs. The precision of FT4-RIAs is satisfactory; inter-assay coefficients of variation are generally lower than 10% for medium hormone concentrations. Because of a change of the standard curve calibration by the manufacturer of the Liquisol kit, the inter-assay variability (17%) of this assay is unacceptably high. The comparison of working ranges shows that the sensitivity of all FT4 assays is sufficient. However, the upper limits of working ranges of the Liquisol and LisoPhase kits are too low. Storing the samples in form of serum yields lower values for any FT4 parameter than storing as whole blood. This unexpected observation is true for room temperature as well as for refrigeration at 4 degrees C. To be sure, the values of indirect FT4 parameters from serum and whole blood coincide somewhat better especially when the samples are stored in the refrigerator. Repeated thawing and refreezing does not influence the results of FT4-RIAs significantly. In vitro testing of drug interferences by addition of therapeutic doses of primidone, phenobarbital, phenytoin and acetylsalicylic acid yields significant effects only for the last quoted pharmaceutical. While the FT4 levels of the Liquisol and LisoPhase assays rise with the acetylsalicylic acid dose according to expectations, the values of the Amerlex and GammaCoat assays decrease. With regard to handling of the tests, there are no special technical problems for all FT4-RIAs tested.

Aspirin↗

PubMed2005

Use of non-aqueous capillary electrophoresis for the quality control of commercial saffron samples.

A non-aqueous capillary electrophoresis (NACE) method for quantifying the seven crocin metabolites that are the major biologically active ingredients of saffron was developed. Separation is done by using a fused silica capillary filled with a 12.5 mM H3BO3/37.5 mM sodium tetraborate methanolic solution as background electrolyte. The results obtained were compared with the total index "safranal value", widely used as a quality measure of saffron products. The comparison revealed that the proposed NACE method provides useful information not obtained in the safranal value. Infact, samples with a similar safranal value can contain crocin metabolites in different concentrations and relative proportions. This new method is very useful for quality control in commercial saffron samples.

Carotenoids↗

PubMedDate not supplied

[Methodology and quality control in EPIGRAM, a pharmacoepidemiological study of obesity in general practice].

The EPIGRAM pharmacoepidemiological study was conducted in general practitioners prescribing orlistat (Xenical) in order to describe, under real clinical conditions, the management of obese or overweight patients. A 1-year follow-up of a patient cohort treated with orlistat was also conducted. Quality criteria specific to the study were defined to ensure the scientific validity of the results; these criteria mainly involved the following items: independent scientific committee, sampling investigator's recruitment, study organisation and quality control of the collected data. On-site control visits of a sample of 13% of participating GPs revealed that 75% of the controlled data were documented in a source file of which 85% were consistent with the source data. Only 1% of the 130 000 controlled data (data were controlled only on visits for which information was available) gave rise to correction requests. Of the patients treated with orlistat on inclusion, 17% were lost to follow-up by their GP and 25% were contacted directly at the end of the study.

Adult↗

PubMed1994

[Centralized preparations of cytostatic agents: a method for quality control].

Cytotoxic drugs are frequently used in a hospital setting. They are mainly administered intravenously and require reconstitution and preparation of the solutions. This is commonly done by nurses in the nursing station. However, cytotoxic drugs are potentially hazardous to personnel and patients, and appropriate waste disposal is necessary. Centralized preparation of cytotoxic medication reduces these risks and problems. We review our experience with centralized preparation and controlled application of chemotherapy in a major medical center. It improves overall safety in reducing exposure to the drugs, while errors of dosage and handling can be decreased and costs and volume of hazardous waste are lower to a substantial extent. Central preparation of cytotoxic drugs is feasible and allows improved quality control.

Antineoplastic Agents↗

PubMed1983

Medicaid program; reduction in error rate tolerance; Medicaid quality control program--HCFA. Interim final rule with comment period.

This interim final rule implements the provisions of section 133 of the Tax Equity and Fiscal Responsibility Act of 1982 (Pub. L. 97-248). These regulations provide for disallowance of Federal financial participation to States whose eligibility payment error rate for Medicaid, as measured by the Medicaid quality control system, exceeds 3 percent for the period April 1 through September 30, 1983, and for each fiscal year thereafter. The regulations further provide for HCFA to project a payment error rate for each State and to reduce the State's quarterly estimate of expenditures if the anticipated error rate exceeds the 3-percent national standard.

Centers for Medicare and Medicaid Services, U.S.↗

PubMed1992

Quality control in nerve conduction studies with coupled knowledge-based system approach.

Contemporary equipment used for nerve conduction studies is usually capable of computerized measurement of latency, amplitude, duration, and area of nerve and muscle action potentials and resulting conduction velocities. Abnormalities can be due to technical error or disease. Identification of technical error is a major element of quality control in electromyography, and artificial intelligence could be useful for this purpose. We have developed a coupled knowledge-based prototype system (QUALICON) to assess the correctness of recording and stimulating characteristics in routine conduction studies. QUALICON extracts numeric features from CMAPs or SNAPs, which are translated into symbolic form to drive a Bayesian network. The network uses high-level knowledge to infer the quality of stimulating and recording electrode placement as well as polarity and stimulus strength making recommendations as to the likely technical error when abnormal potentials are detected. A preliminary assessment shows that QUALICON performs as well as manual assessment performed by professionals.

Action Potentials↗