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PubMedDate not supplied

Under fives nutritional status in rural communities in western Nigeria. Use of age-standardised weight and mid upper arm circumference.

The nutritional status of all children under five years in each of two rural areas in the forest belt of western Nigeria was assessed by visiting overseas medical students. Each child under five was weighed and their mid upper arm circumference (MUAC) measured. One quarter of the children had weights below the third percentile for age (WHO standards). In one village nearly half of 45 children had weights below the third percentile and one sixth had weights further below the median than three standard deviations. Standardised weight scores (against reference standards) tended to be a little higher than, but correlated fairly well (r = 0.67) with standardised MUAC. New amalgamated standards for MUAC from 0 to 60 months are presented.

Age Factors↗
PubMed1990

The effect of immersion disinfection of elastomeric impressions on the surface detail reproduction of improved gypsum casts.

This investigation examined improved gypsum casts for surface roughness and line-detail reproduction after the immersion disinfection of elastomeric impression materials in an acid glutaraldehyde, an alkaline glutaraldehyde, and a phenol. Impressions were made of a surface roughness standard (Ra = 3.08 microns) that was custom made to include engraved grooves following American Dental Association specification No. 19. Mean surface roughness (Ra) values for all casts of all combinations of disinfectant treatments, impression materials, and improved gypsum stones were obtained with a surface analyzer. Untreated impressions served as controls. Data examined by an analysis of variance indicated that the addition silicone and polyether impression materials provided a surface roughness similar to the precision displacement specimen standard. The acid glutaraldehyde disinfectant demonstrated enhanced line-detail reproduction compared with the standard. Addition silicone and polyether impression materials combined with the acid glutaraldehyde provided the model system closest to the mean surface roughness of the reference standard. These combinations revealed differences in the surface roughness reproduction among the represented improved dental stones.

Calcium Sulfate↗
PubMed2005

Quantitation of cardiolipin molecular species in spontaneously hypertensive heart failure rats using electrospray ionization mass spectrometry.

Electrospray ionization mass spectrometry has previously been used to probe qualitative changes in the phospholipid cardiolipin (CL), but it has rarely been used in a quantitative manner. We assessed changes in the amount of individual molecular species of cardiac CL present in a model of congestive heart failure using 1,1',2,2'-tetramyristoyl cardiolipin as an internal standard. There was a linear relationship between the ratio of the negative molecular ion ([M-H]-) current from four different CL reference standards and the [M-H]- from the internal standard, as a function of the concentration of CL molecular species. Therefore, this internal standard can be used to quantitate many naturally occurring CL molecular species over a wide range of CL concentrations. Using this method, changes to individual molecular species of CL in failing hearts from male spontaneously hypertensive heart failure rats were examined. CL isolated from cardiac mitochondria was compared with left ventricular tissue to demonstrate the feasibility of extracting and quantitating CL from either mitochondrial or tissue samples. The acyl chain composition of individual CL molecular species was identified using tandem mass spectrometry. In animals with heart failure, the major cardiac CL species (tetralinoloyl) decreased significantly, whereas other minor CL species were significantly increased.

Animals↗
PubMed1993

Comparison of the use of Tanner and Whitehouse, NCHS, and Cambridge standards in infancy.

The British (Tanner and Whitehouse) and American (National Center for Health Statistics, NCHS) growth standards are widely used internationally, although the data are now over 30 years old. Routine weight data was retrieved from the child health records of a complete annual cohort of 3418 children aged 18-30 months to test the validity of these standards for modern infants. Compared with the Tanner and Whitehouse standards, Newcastle children rose initially and then fell a mean of 0.7 SDs between 6 weeks and 18 months, resulting in a threefold difference in the proportion of children below the 3rd centile at different ages. NCHS standards showed a similar pattern. When compared with modern standards from the Cambridge growth study, there was a much closer match, although Newcastle children showed a slight gain by the age of 1 year. Existing standards for weight introduce inaccuracy into the estimation of centile position in the early months of life. As both standards show similar problems this probably represents a real secular change due to changes in infant nutrition. These findings support the need to develop new national growth reference standards.

Anthropometry↗
PubMed1988

Standardization of allergen extracts.

In order to increase the precision of diagnosis and the safety of specific immunotherapy, standardization of allergenic extracts has increasingly been required. Because allergenic extracts are complex mixtures of potential allergenic components, it is appropriate to express the composition and potency relative to a standard. Several such standard reference extracts have now been established by international working groups (statued as subcommittees under IUIS and WHO) and are available from central control authorities. The international standards (IS) are available freeze-dried in ampoules and are meant as calibrators (not prototypes) for use in research, production and quality control. The potency of each ampoule is defined the arbitrary assignment of 100,000 IU, whatever potency determination method is used. In individual laboratories the internal reference should be assigned a potency relative to the IS by each of the commonly used methods. This should enable the collaboration of researchers, manufacturers, and control authorities and improve safety in practical immunotherapy.

Allergens↗
PubMed2006

Enzyme-linked immunosorbent assay for measuring antibodies to pneumococcal polysaccharides for the PNEUMOVAX 23 vaccine: assay operating characteristics and correlation to the WHO international assay.

The Merck pneumococcal (Pn) enzyme-linked immunosorbent assays (ELISAs) for measuring antibodies to 12 serotypes (serotypes 1, 3, 4, 6B, 7F, 8, 9V, 12F, 14, 18C, 19F, and 23F) were validated in 1999. Merck Laboratories developed the Pn assays using 10 microg/ml C polysaccharide, 100 microg/ml Pn polysaccharide (PnPs) 25, and 100 microg/ml PnPs 72 for preadsorption of samples, standards, and controls in order to improve the specificity to the Pn serotypes in the vaccine. The Pn assays utilize postimmunization sera obtained from subjects immunized with PNEUMOVAX 23 as standards for measuring immunoglobulin G concentrations in sera obtained from vaccine clinical trials with adults and infants. This material was calibrated to the Pn reference standard serum, 89SF, subjected to the Merck Pn ELISA adsorbants. Comparisons were made between the Merck Pn assay and the international Pn assay, showing moderate agreement between the two assay formats. This work describes the test procedures and operating characteristics of the Merck Pn assays and the results of experiments performed to compare the Merck Pn ELISAs to the international Pn ELISAs.

Adult↗
PubMed1994

Standards for X-ray microanalysis of calcified structures.

The ability of electron probe X-ray microanalysis (EPMA) to solve biological problems often depends on the use of a quantitative approach. EPMA allows the quantitative determination of chemical elements of biological materials by using reference standards which resemble the specimen in the mode of interaction with the electron beam. Although there is a large experience in the quantification of elements in biological thin specimens, experience with standards for X-ray microanalysis of bulk specimens is limited, especially for calcified structures where the density of the specimen is difficult to estimate. The quality of the results in EPMA depends on obtaining accurate calibration curves which allow the establishment of the relationship between the signal measured and the concentration of the element of interest. The different methods for specimen preparation and the thickness of the specimen will also determine the precise nature of the standardization technique to be adopted. The physics of the electron beam-specimen interactions impose limitations upon the accuracy of calibration, and the choice of an unstable standard can result in large errors in the quantification of elements. We have reviewed the different types of compounds that have been used as standards for biological EPMA of thin and bulk specimens and discuss their potential use for quantitative analysis of mineralized tissues, with special reference to otoconia, the calcified structures of the vestibular system.

Animals↗
PubMed1987

SEAPAL quality control analysis of rheumatoid factor measurement in 29 diagnostic laboratories.

A programme for rheumatoid factor (RF) measurement was sponsored by the South East Asian Pacific League against Rheumatism (SEAPAL) and the Clinical Immunology Group (CIG) of the Australian Society for Immunology. Measurements in 29 laboratories in 12 countries showed: a large variety of methods were being used to measure RF, most using semiquantitative agglutination techniques; some laboratories have invalid techniques; the quoted upper normal limit varied considerably between assays, and false positives were identified in three laboratories; a wide range of intralaboratory precision within and between assays; and a reduction in discordance between laboratories by the inclusion of local standards. Before international standardisation of RF measurement can be achieved attention to many of these problems is required. In particular we recommend the wider use of reference standards and the regular participation in quality control programmes in order to monitor performance.

Asia, Southeastern↗
PubMed2003

Genetic effects on baseline values of C-reactive protein and serum amyloid a protein: a comparison of monozygotic and dizygotic twins.

BACKGROUND: C-Reactive protein (CRP) and serum amyloid A protein (SAA) are exquisitely sensitive acute-phase reactants, but their baseline values are surprisingly constant in individuals in the general population. These values, especially of CRP, are associated with future atherothrombotic events, and the determinants of baseline CRP and SAA concentration are therefore of considerable interest. METHODS: CRP and SAA concentrations were measured by well-validated automated microparticle capture enzyme immunoassays, standardized on the respective WHO International Reference Standards, in serum from 146 monozygotic and 164 dizygotic healthy female UK twin pairs from the general population, with mean (range) ages of 58.0 (40-69.6) and 55.7 (40-70.3) years, respectively, who were also very closely matched for height, weight, body mass index, blood pressure, and lifestyle variables. Statistical modeling based on variance components analysis was used to estimate the genetic contribution to the observed values. RESULTS: As reported previously, CRP values were associated with body mass index, smoking, and hormone replacement therapy. After exclusion of the few samples with CRP concentrations >10 mg/L, which indicate an ongoing acute-phase response rather than baseline values, and inclusion of adjustments for all known confounding variables, there was significantly higher correlation of CRP and SAA results among monozygotic than among dizygotic twins. The estimated hereditability (95% confidence interval) of baseline values was 52% (40-62%) for CRP and 59% (49-67%) for SAA. CONCLUSION: There is a substantial genetic contribution to baseline serum concentrations of CRP and SAA.

Adult↗
PubMed2002

Determination of accuracy in neonates for non-invasive blood pressure device using an improved algorithm.

BACKGROUND: New software (SuperSTAT(R) algorithm) with enhancements aimed at shorter determination times was developed for a non-invasive blood pressure (NIBP) device and a clinical evaluation was conducted to verify accuracy. OBJECTIVE: To determine the accuracy of the new algorithm according to ANSI/AAMI SP10-1992 and SP10A-1996 American National Standard for Electronic or Automated Sphygmomanometers. METHODS: The blood pressure values obtained from the test device were compared to the intra-arterial blood pressure reference standard (IBP). RESULTS: The NIBP and IBP comparisons for systolic, diastolic, and mean arterial pressure met the 1992 ANSI/AAMI accuracy standards by being within a mean difference of +/- 5 mmHg and standard deviation of < or = 8 mmHg. CONCLUSION: Non-invasive blood pressure determinations taken with the new algorithm, developed to provide greater patient comfort due to faster determinations, were accurate when compared to neonatal IBP.

Algorithms↗
PubMed1999

Reference methods in clinical chemistry.

For the measurements of analyses such as glucose, creatinine etc, in clinical chemistry, definitive methods and standard reference materials are available. On the other hand, for the measurements of the catalytic activity concentration of enzymes, various methods have been developed and those methods have generated a variety of results and reference ranges, difficulties in the interpretation of results, and difficulties in external quality assessment programs. Therefore, for the measurement of the catalytic activity of an enzyme, reference method is very important as the first start to obtain an accurate and precise result. We report the present situation of standardization for the measurement of the catalytic activity of enzymes and the comparison of reference methods including standards or consensus methods for the representative enzymes recommended by International Federation of Clinical Chemistry and the representative societies of clinical chemistry, and the survey results produced by Japan Medical Association.

Catalysis↗
PubMed1985

Acid dissociation constants and pH values for standard "bes" and "tricine" buffer solutions in 30, 40, and 50 mass% dimethyl sulfoxide/water between 25 and -25 degrees C.

Information is given concerning two standard buffer solutions suitable as pH references in 30, 40, and 50 mass% dimethyl sulfoxide (DMSO)/H2O mixed solvents at subzero temperatures from -20 to 0 degrees C, with the intention of establishing a pH (designated pH*) scale. The two buffers selected were the ampholytes N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid ("bes") and N-tris(hydroxymethyl)methylglycine ("tricine"), and the reference standard consisted of equal molal quantities of the buffer and its respective sodium salt. The assignment of pH* values was based on measurements of the emf of cells without liquid junction of the type: Pt;H2(g,l atm) /Bes, Na Besate, NaCl / AgCl;Ag and Pt;H2(g,l atm) /Tricine, Na Tricinate, NaCl /AgCl;Ag and the pH* was derived from a determination of K2, the equilibrium constant for the dissociation process (Buffer)+/- in equilibrium with(Buffer)- + H+.

Alkanesulfonates↗
PubMedDate not supplied

The feasibility of low-dose CT for pulmonary metastasis in patients with primary gynecologic malignancy.

PURPOSE: To assess the feasibility of low-dose CT (LDCT) in the detection of pulmonary metastases in patients with primary gynecologic malignancies and also to compare the performance of chest digital radiography (DR) and LDCT for their delectability of pulmonary metastases, with use of standard-dose CT (SDCT) as the reference standard. MATERIALS AND METHODS: Thirty female patients with primary gynecologic malignancies (age range, 20-76 years; mean age, 50 years) underwent DR, noncontrast LDCT and contrast-enhanced SDCT, which were performed within an interval of 2 weeks. We used lung nodule, mediastinal lymphadenopathy (>10 mm in the short axis) and pleural changes (including effusion, irregular thickening, or nodularity) as the cardinal imaging findings of lung metastases. A five-point scoring system was designed to indicate the probability of lung metastasis from primary gynecologic malignancies. The five-point scores of DR, LDCT, and SDCT were analyzed by receiver operating characteristic (ROC) curve. RESULTS: SDCT probability scores of +2 and -2 were set to indicate true positive and true negative for pulmonary nodule, mediastinal lymphadenopathy, and pleural effusion, respectively. All the areas under the ROC curve of LDCT appeared to be larger than those of DR[pulmonary nodule: 0.96 [95% confidence interval (CI): 0.92-1.01] vs. 0.74 [95% CI: 0.57-0.91], 0.82 [95% CI: 0.70-0.95] vs. 0.61 [95% CI: 0.50-0.77]; mediastinal lymphadenopathy: 0.98 [95% CI: 0.93-1.03] vs. 0.90 [95% CI: 0.79-1.01], 0.94 [95% CI: 0.82-1.06] vs. 0.66 [95% CI: 0.44-0.88]; and pleural effusion: 0.98 [95% CI: 0.93-1.03] vs. 0.56 [95% CI: 0.29-0.82], 0.90 [95% CI: 0.74-1.05] vs. 0.46 [95% CI: 0.23-0.68]]. CONCLUSION: The performance of LDCT were comparable to those of SDCT and superior to those of DR for detection of pulmonary nodule, mediastinal lymphadenopathy, and pleural effusion. By using LDCT, there was no need of intravenous contrast injection and less radiation exposure. We propose a protocol including standard-dose abdominal CT and low-dose chest CT for the initial and follow-up stagings of primary gynecologic malignancy. The use of chest DR is unnecessary.

Adult↗
PubMed1999

A time course study on STR profiles derived from human bone, muscle, and bone marrow.

The use of the polymerase chain reaction (PCR) to define deoxyribonucleic acid (DNA) types at several loci was investigated. PCR was used to amplify nine short tandem repeat (STR) loci along with the amelogenin locus on the X and Y chromosomes using the AmpF/STR Profiler Plus PCR amplification kit (Perkin Elmer). Rib bones were collected from 12 individuals. Five cm portions were buried at a depth of approximately 30 cm and 5 cm portions were left on the surface of the ground. Samples were exposed to the environment for periods of time ranging from two weeks to 17 months. Dried blood standards were prepared for use as reference standards for each rib sample. Bone, muscle, and bone marrow were collected from each sample. DNA from each tissue type was extracted. Complete profile results were obtained from the surface bone samples out to an exposure time of 17 months. None of the muscle or bone marrow samples produced complete profile results beyond eight weeks. All DNA typing results from complete or incomplete profiles were consistent with DNA typing results of the corresponding blood standard. Results suggest that using the AmpF/STR Profiler Plus PCR Amplification Kit is a valid way to establish the DNA profile of tissue types from human remains.

Alleles↗
PubMedDate not supplied

[Validation of an ELISA for the measurement of human IgG against serogroup B Neisseria meningitidis protein].

An indirect ELISA test was optimised in which B meningoccocus outer membrane proteins included in the Cuban Vaccine known as VA-MENGOC-BC were used as capture antigents. Specific antibodies in serum samples from vaccinated individuals were detected using a human anti-IgG conjugate, i.e. alklayne phosphatase, thus the reaction developed with a specific substrate called p-nitrophenilphophate. Standard serum was obtained from a reference standard, the gage curve range was 625 to 20,000/mL. The control serum was selected from the most interesting areas for the samples, hence, assay characteristics were determined. Intra-assay, inter-assay and total inaccuracies were lower than 10% in the most linear area of the curve. Detectability was 700/mL. Recovery, paralelism and linearity studies showed an under 10% inaccuracy.

Bacterial Proteins↗
PubMedDate not supplied

[Role of mycoplasma pneumoniae infection in aetiopathogenesis of juvenile idiopatic arthritis].

UNLABELLED: Although more and more is known about chronic autoimmune diseases, attempts to establish one trigger factor have been unsuccessful. The role of endogenic factors is beyond doubt. But it is emphasized that environmental factors are necessary to cause the disease. Infections are taken under consideration as trigger mechanism in the development of autoimmune diseases including chronic arthritis. Both numerous viruses and bacteria are among the microorganism mentioned. We considered it sensible to conduct research on Mycoplasma pneumoniae infections in a group of patients with juvenile idiopathic arthritis (JIA). MATERIALS: 19 patients diagnosed with JIA aged between 6-17 were investigated for Mycoplasma pneumoniae infection whose blood was examined for antibodies against Mycoplasma pneumoniae in class IgG and IgM. The control group comprised 20 children of similar age admitted to hospital with digestive tract complaints. METHODS: Serologic tests were made in serum. Marking of antigens of class IgM and IgG were made by Elisa method using commercial kits produced by Scientific Point. Quantitative calculations of a level of antigens were done using appropriate standards, positive and negative serum of reference standard and calibration curve. RESULTS: In 11 patients positive reaction for Mycoplasma pneumoniae in class IgG was observed and only in 2 in class IgM with low titer. In the control group positive reaction was observed in 3 children (15%). The fact that 58% of patients were infected (contact either with Mycoplasma pneumoniae) indicates that in the group of our patients with JIA, infections with these bacteria might have had a role in triggering the disease.

Adolescent↗
PubMed2006

Development of a subject search filter to find information relevant to palliative care in the general medical literature.

PURPOSE: The research developed and validated palliative care search filters for use in the general biomedical literature. METHODS: Four general medical journals were hand-searched to identify articles relevant to palliative care, forming a "gold standard" reference set. Searches comprising Medical Subject Headings (MeSH) and text-words were created for use in Ovid MEDLINE, and retrieved references were compared to the gold standard. Sensitivity, specificity, accuracy, and precision rates were calculated. RESULTS: By hand-searching 20,501 articles published in the 4 journals during the 3-year study period (1999-2001), reviewers identified 773 items relevant to palliative care (3.8%). A master search combining 9 MeSH descriptors with 3 text-words achieved 45.4% sensitivity, 99.3% specificity, 73% precision, and 97.3% accuracy. Efforts to increase the sensitivity by modifying 3 relevant published but unvalidated searches did not improve the yield, except in 1 case which resulted in an improved sensitivity of 56.9% but was offset by reduced specificity (92.1%), precision (22%), and accuracy (90.8%). CONCLUSIONS: The study confirmed that literature relevant to palliative care is difficult to identify in general medical journals. While the filter developed in this research represents the best trade-off between sensitivity, specificity, accuracy, and precision, the sensitivity is unacceptably low. Further research, such as frequency analysis of text-words and MeSH terms, is required to increase the sensitivity of searching in this subset of the literature.

Humans↗
PubMed1999

Impact of DNA typing on standards and practice in the forensic community.

This article reviews the history of DNA-based human identification from its inception in 1985. Since the development of the technology, experts called for setting of standards and use of proficiency tests for quality assurance measures. The response of the National Institute of Standards and Technology to DNA forensic standards needs was catalyzed by the Technical Working Group on DNA Analysis Methods, sponsored by the Federal Bureau of Investigation with funding provided by the National Institute of Justice. Standard reference materials were developed for the original technologies used in DNA identification and for the newer polymerase chain reaction-based technologies. Adoption of recommended standards developed through the Federal Bureau of Investigation-commissioned DNA Advisory Board show the acceptance of National Institute of Standards and Technology standards for calibration of laboratory protocols. New technologies will require a process of validation and continued testing through the use of proficiency tests, such as those provided through the College of American Pathologists. Robotics and parallel processing of samples will lead to increased efficiency in DNA testing. The use of DNA data banks of convicted felons will increase dramatically with the the Federal Bureau of Investigation's national implementation of a computerized identification system known as the Combined DNA Index System. This system that will make major use of short, tandem, repeat genetic systems and will be the major driver of technology for the next 5 to 10 years. Finally, sample collection and training are of major concern for those who look at the long-term impact of DNA testing in forensic laboratories.

DNA↗