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At least 1,495 records · Page 83Linked to original sources
PubMed1984

[Quality assurance and quality control of blood pressure measurements. Experiences with the Munich blood pressure study].

More than 12 000 blood pressure measurements were taken in the Munich Blood Pressure Study (MBS). The reliability of these blood pressure measurements is reported. After consideration of possibilities for systematic and random measurement errors we present methods used in the MBS to control and assess the quality of the blood pressure readings over a long period of time: measures for standardizing the recording conditions and procedures; training and testing of the field staff using audio tape-recording and simultaneous measurements with a double stethoscope; analysis of inter- and intraobserver-variation relative to that of reference measurements; analysis of observer preferences for certain terminal digits. With the application of these methods one can indeed successfully reduce observer variability to a tolerable amount even over a considerable period of time.

Blood Pressure Determination↗
PubMed2005

CHIP, a cochaperone/ubiquitin ligase that regulates protein quality control, is required for maximal cardioprotection after myocardial infarction in mice.

Limitation of damage after ischemia and reperfusion injury to the myocardium remains an elusive clinical goal. Previous studies have suggested that molecular chaperones, which include members of the heat shock protein (Hsp) family, may have cardioprotective effects, although the protective role of endogenous chaperones has not been well documented. CHIP (carboxyl terminus of Hsp70-interacting protein) is a cochaperone/ubiquitin ligase that integrates the response to stress at multiple levels. We tested the response of CHIP(-/-) mice to in vivo ischemia and reperfusion injury induced by left anterior descending coronary artery ligation. Compared with wild-type littermates, CHIP(-/-) mice had decreased survival and increased incidence of arrhythmias during reperfusion. The size of myocardial infarction, as assessed by the ratio of infarct area to area at risk, was 50% greater in CHIP(-/-) mice. Increased infarct size was accompanied by impaired upregulation of the chaperone Hsp70 after ischemia-reperfusion injury. In situ analysis also indicated that hearts of CHIP(-/-) mice were more prone to develop apoptosis in cardiomyocytes and especially endothelial cells of intramural vessels. Previous studies have found that CHIP plays a central role in maintaining protein quality control and coordinating the response to stress. The present data indicate that these functions of CHIP provide a critical cardioprotective effect in the setting of ischemia-reperfusion injury due in part to increased apoptosis in cardiac cells. Quality control mechanisms therefore may be underappreciated clinical targets for maximizing myocardial protection after injury.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Quality control of end results in a Danish adjuvant breast cancer multi-center study.

In a Danish multi-center study, quality control was performed on off-study data for high-risk breast cancer patients included in protocols of adjuvant therapy. In the two protocols 4455 patients were randomized and 2477 were registered off-study. Data from these patients were validated by reviewing the patients' records. Incorrect data were observed in 16.2% of the cases who went off-study due to recurrence, other malignant disease or death. In 258 of 2133 patients unidentical locations were demonstrated. Of these, 104 showed a time difference also. A major difference in site of recurrence was found in 107 patients (5.0%), 43 of whom were upstaged from local to a distant recurrence and 64 were downstaged. A time difference of more than 30 days was found in 192 patients (9.0%) and in 17 the difference exceeded 366 days. A time difference only was found in 88 patients (4%). The major parameter in the statistical analysis of the two protocols, i.e. recurrence-free survival, was not significantly influenced by the validation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Improved quality control method for Danshen products--consideration of both hydrophilic and lipophilic active components.

The current study intends to provide an improved quality control analysis for Danshen product-a representative herbal product with known active components that are both hydrophilic and lipophilic in nature. A simple HPLC method with photodiode-array (PDA) ultraviolet detection was developed for the simultaneous determination of three major lipophilic components (cryptotanshinone, tanshinone I and tanshinone IIA) and three major hydrophilic components (danshensu, protocatechuic aldehyde and salvianolic acid B) of Danshen (Salvia miltiorrhiza). These six components were successfully separated using Radial-pak C18 cartridge with the elution gradient consisting of 0.5% acetic acid in water and 0.5% acetic acid in acetonitrile at a flow rate of 1 ml/min. The intra-day and inter-day precisions of the analysis were within 2.32 and 2.0%, respectively. The detection limits were 0.02, 0.01, 0.01, 0.05, 0.005 and 0.02 microg/ml for cryptotanshinone, tanshinone I, tanshinone IIA, danshensu, protocatechuic aldehyde and salvianolic acid B, respectively. The developed method has been applied to the simultaneous determination of above six major components in Fufang Danshen Tablet and Dripping Pill products by extraction with methanol and water. It has been demonstrated that salvianolic acid B and danshensu are the major components among the eight commercial Fufang Danshen products studied. The current developed method with methanol as extraction solvent provides a simple and efficient method for simultaneous detection of both lipophilic and hydrophilic major components in Danshen products.

Chromatography, High Pressure Liquid↗
PubMed2000

The influence of flood source placement on radiation exposure during quality control testing.

OBJECTIVE: This study examined the photon energy distribution and exposure rate from a 250-MBq 57Co flood source during quality control (QC) procedures as a function of source placement and measurement location. The optimum placement of the source to reduce the radiation dose to the nuclear medicine technologist during QC checks was determined. METHODS: Measurements of exposure rate were made inside and outside a camera room with the source positioned either above or below the camera head. The energy distribution of the photon field was examined at the same locations using a high-resolution gamma-ray spectrometer. Additional measures of exposure rate were made with the source at various distances from the camera face. RESULTS: The lowest exposure rates occurred when the source was lying directly on the face of the camera head. The exposure rates at locations inside the camera room increased by a factor of 4.3 +/- 3.0 when the source was placed on an imaging table below the camera head. This increase can be attributed to decreased shielding provided by the camera head. CONCLUSION: A large portion of the radiation dose received by technologists during QC checks is due to scattered radiation and x-rays produced by gamma-ray interactions within the camera. This dose can be reduced significantly if QC checks are performed with the flood source lying directly on the inverted gamma camera head rather than placing the flood source on an imaging table under the gamma camera.

Cobalt Radioisotopes↗
PubMed2006

[Some possibilities of using spectrometry in the near infrared region in drug quality control].

Spectrometry in the near infrared region ranks among the modern methods of analytical chemistry and is of use also in drug quality control. The paper draws attention to some possibilities of using the method in this respect, including its possible use in the check-out of the identity of the content of closed packages of medicinal and auxiliary substances supplied to pharmacies.

Pharmaceutical Preparations↗
PubMed2001

Assessment of BMS284756 MIC and 5-microg disk diffusion quality control studies tested against seven American type culture collection strains.

BMS284756 is a novel des-fluoro(6)-quinolone with antimicrobial activity similar to recently developed fluorinated quinolones. The purpose of this investigation was to determine the appropriate disk diffusion and MIC quality control (QC) ranges for BMS284756 when used against commonly tested QC strains (M23-A2). The BMS284756 5-microg disk content was tested against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Hemophilus influenzae ATCC 49247, Streptococcus pneumoniae ATCC 49619 and Staphylococcus aureus ATCC 25923. In addition, Enterococcus faecalis ATCC 29212 and S. aureus ATCC 29213 were evaluated by the broth microdilution method. Seven laboratories tested 2 disk lots on 3 agar media or 3-4 broth lots over a 10 day period. A total of 420 zone diameter values and 210 or 280 MIC values per organism were generated. The following disk diffusion and MIC QC ranges were suggested for BMS284756 and the seven QC strains: E. coli ATCC 25922 (28-35 mm/0.004-0.016 microg/mL), E. faecalis ATCC 29212 (0.03-0.25 microg/mL), S. aureus ATCC 25923 (30-36 mm), S. aureus ATCC 29213 (0.004-0.016 microg/mL), P. aeruginosa ATCC 27853 (19-25 mm/0.5-2 microg/mL), H. influenzae ATCC 49247 (33-41 mm/0.002-0.008 microg/mL), S. pneumoniae ATCC (26-33 mm/0.016-0.06 microg/mL). The proportion of participant results observed within the proposed ranges was 97.4-98.8% and 94.6-100% for the disk diffusion and MIC tests, respectively.

Anti-Infective Agents↗
PubMed1986

Quality control requirements in estrogen receptor determination.

The clinical significance of estrogen receptor (ER) levels determined in breast cancer tissue depends on the quality of the ER assay procedure itself as well as on several critical factors beyond the direct responsibility of the receptor laboratory. A novel immunobiochemical assay (ER-EIA) has been made available by Abbott Laboratories. In comparison to the classical radioligand binding assay, the use of ER-EIA resulted in lower intra- and interassay as well as interlaboratory coefficients of variation. This may be explained by the complete standardization of ER-EIA as compared to ER radioligand binding assay. Considerable attention must be paid to the source of origin of quality control material if identical ER levels are to be obtained by both methods, as the monoclonal antibodies of ER-EIA bind less avidly to cytosolic ER of calf uterus and, in contrast to routine ER radioligand binding assay, are able to recognize occupied ER.

Antibodies, Monoclonal↗
PubMed2004

Quality control of bacterial contamination in autologous peripheral blood stem cells for transplantation.

BACKGROUND AND OBJECTIVES: Microbiological follow-up is part of quality control of peripheral blood stem cell (PBSC) manipulation. DESIGN AND METHODS: We prospectively studied microbiological cultures performed in 865 consecutive untreated autologous PBSC harvests from 348 patients. Our aim was to know the rate of microbiological contamination, the optimum moment to evaluate the sample and the clinical significance of the positive findings. RESULTS: Fifty-nine of the 852 samples (6.9%) yielded a positive culture after PBSC collection (sample 1) and 62 samples also yielded positive results before cryopreservation (7.2%) (sample 2). At the time of the analysis, a total of 520 aphereses had been infused and the number of positive cultures after thawing (sample 3) and after washing (sample 4; 82 aphereses) was 5.4% and 2.3%, respectively. Most of the positive cultures were due to coagulase-negative staphylococci (48 isolates). After thawing 15 coagulase-negative staphylococci and 2 enterococci isolates were recovered. Comparison between samples using a marginal homogeneity test showed no differences in the rate of contamination observed at the different sampling points. INTERPRETATION AND CONCLUSIONS: Positive microbiological findings in collected PBSC are not due to contamination within the laboratory. Cryopreservation using DMSO does not eradicate bacteria and manipulation does not seem to affect results. To simplify the procedure it would be possible to eliminate the microbiological controls performed immediately before cryopreservation.

Antibiotic Prophylaxis↗
PubMed1994

[Guidelines for radiation protection in medicine--radiopharmaceutical quality control. German Society of Nuclear Medicine].

For the first time the revision of the "Guideline for radiation protection in medicine" defines extensive quality control procedures for radiopharmaceuticals. The principles of the 99Mo/99mTc-generator, the preparation of 99mTc-radiopharmaceuticals and the origin of the most frequent radiochemical impurities are illustrated. An introduction into the theory of thin layer chromatography is combined with a listing of radiochromatographic systems. This enables the determination of the radiochemical purity of the most important radiopharmaceuticals in clinical routine.

Germany↗
PubMed1975

[Results of 2 quality control programs performed in Tuscany in the year 1973 and 1974].

Here after are reported all the results obtained from an interlaboratory quality control program performed in Tuscany in 1973 and in 1974. In 1973, 35 hospital laboratories partecipated to the program, while in 1974 the partecipating laboratories were 79: hospital's, private's and of public bodies. The results obtained in the program performed in 1974 were less satisfactory of those obtained in 1973 and showed the need of repeating such programs in order to improve the operating efficiency of laboratories.

Blood Glucose↗
PubMed1999

Capillary electrophoretic method for quality control of phospholipid products.

A practical, low cost capillary electrophoretic method for phospholipid products employed in pharmaceutical, cosmetic and food industries with quality control purposes is described. The phospholipid components of the samples were hydrolyzed prior to their electrophoretic separation. The carrier electrolyte to determine choline, ethanolamine and serine consisted of 5 mM imidazole, pH 3.0 using indirect UV detection at 214 nm. Inositol was quantified employing a buffer of 40 mM sodium borate, pH 10.0 at 40 degrees C and detection at 185 nm. Analytical parameters were evaluated and the results obtained of phospholipid composition in commercial samples from soybeans and animal sources showed acceptable values.

Electrophoresis, Capillary↗