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PubMed2001

Detection of adulteration in Australian orange juices by stable carbon isotope ratio analysis (SCIRA).

Stable carbon isotope ratio analysis (SCIRA) was used to determine the authenticity of commercial Australian orange juices. Thirty-five samples of Valencia (delta(13)C values from -23.8 to -24.7 ppt) and eight samples of Navel juices (delta(13)C values from -24.1 to -24.5 ppt) of known origin were used to establish a decision level before analysis. No significant seasonal variations in (13)C/(12)C ratio were observed. Variations in combustion temperature in the method were also found to be insignificant.

Australia↗

PubMed2005

Patterns and predictors of prescription medication use in the management of headache: findings from the 2000 Medical Expenditure Panel Survey.

OBJECTIVE: The primary objectives were to examine national trends of prescription medication use for headache and explore patterns of variation in the use of these medications across social and demographic levels. BACKGROUND: Despite widespread use of prescription medication for management of headache, little is known about utilization patterns or patient characteristics associated with receiving this type of treatment. METHODS: This study conducted a secondary analysis of data obtained during the 2000 Medical Expenditure Panel Survey, a representative survey of the U.S. noninstitutionalized population. Weighted descriptive statistics and logistic regression models were used to evaluate patterns and rates of overall prescription medication use in patients reporting headache as a household condition. RESULTS: An estimated 9.7 million people 18 years or older reported suffering from headache in 2000. Of these, 46% reported using at least one medication for the treatment of headache. Migraine-specific abortive medication (ie, selective serotonin receptor agonists and ergotamine derivatives) was the most frequently reported medication class, used by 36% of participants. Opiate analgesics and butalbital-containing products also experienced extensive prescribing reported by 22% and 17% of survey respondents, respectively. After adjustment for covariates, wide variation in the use of prescription medication was observed across sociodemographic characteristics including age, ethnicity, and insurance status. CONCLUSION: The observed variation in prescription medication use by drug class and sociodemographic characteristics suggests strategies are needed for improving current prescribing patterns in this patient population.

Adult↗

PubMed1984

Seasonal variation of febrile convulsion in Japan.

The 6-year incidence rates of febrile convulsions in all 3-year-old children in Fuchu (covering 95% of children, number examined 17,044) was 8.2%. The incidence was higher in boys than in girls (9.0%: 7.5%, P less than 0.001). The incidence rates varied with the month and year of birth, but the variations observed were slight. Two peak appearances of seasonal variation of the first febrile convulsion were found in November-January and in June-August. The former could be interpreted as a tendency to winter virus infection of the upper respiratory tract in children. The other peak in summer could be explained as a tendency to gastrointestinal infection. Liability to febrile convulsion was influenced by the age of children and by the seasonal variations of febrile illness, but not by the season of birth.

Age Factors↗

PubMed1989

Applications of automated simultaneous double fluorescence (SDF). II. HLA class I phenotyping using immunomagnetically separated T lymphocytes.

HLA class I phenotyping was performed using T-lymphocyte populations isolated by immunomagnetic beads (IMBs) coated with monoclonal antibodies with specificity for CD2, CD4 or CD8. The results were compared to those obtained using density gradient-separated lymphocytes (PBL). The typing trays were read by the automated simultaneous double-fluorescence (SDF) technique previously established in our laboratory using an Astroscan 2100 system. The aims of the present study were to establish whether the advantages of IMB lymphocyte separation and automated plate reading by SDF were complementary and whether the results obtained by IMB-SDF and PBL-SDF were concordant. Similarity coefficients for paired results obtained by IMB-SDF and PBL-SDF varied between 0.825 using anti-CD8-coated IMBs and 0.914 using anti-CD4-coated IMBs with a consistent excess of stronger results observed with the PBL-SDF technique. The variations observed did not result in incorrect phenotype assignment but would significantly influence a cross-matching test. These results illustrate the feasibility of using IMB-separated lymphocytes for HLA phenotyping by SDF.

Antibodies, Monoclonal↗

PubMed1979

Relationship between serum and saliva chloramphenicol concentrations.

The relationship between serum and saliva chloramphenicol (CAP) concentrations was evaluated in 27 paired specimens collected from 20 hospitalized patients during therapy with the drug. A significant (R = 0.80, P < 0.001) but variable relationship was found to exist. Serum protein binding of CAP was also evaluated (43.7 +/- 5.7% bound; N = 24). Differences in CAP binding did not apparently account for a significant portion of the variability in the observed saliva/serum CAP concentration ratios. The degree of variation observed indicated that saliva CAP concentrations could not be relied upon for the prediction of serum CAP concentrations.

Adult↗

PubMed1988

Estimating bacterial production in marine waters from the simultaneous incorporation of thymidine and leucine.

We examined the simultaneous incorporation of [H]thymidine and [C]leucine to obtain two independent indices of bacterial production (DNA and protein syntheses) in a single incubation. Incorporation rates of leucine estimated by the dual-label method were generally higher than those obtained by the single-label method, but the differences were small (dual/single = 1.1 +/- 0.2 [mean +/- standard deviation]) and were probably due to the presence of labeled leucyl-tRNA in the cold trichloroacetic acid-insoluble fraction. There were no significant differences in thymidine incorporation between dual- and single-label incubations (dual/ single = 1.03 +/- 0.13). Addition of the two substrates in relatively large amounts (25 nM) did not apparently increase bacterial activity during short incubations (<5 h). With the dual-label method we found that thymidine and leucine incorporation rates covaried over depth profiles of the Chesapeake Bay. Estimates of bacterial production based on thymidine and leucine differed by less than 25%. Although the need for appropriate conversion factors has not been eliminated, the dual-label approach can be used to examine the variation in bacterial production while ensuring that the observed variation in incorporation rates is due to real changes in bacterial production rather than changes in conversion factors or introduction of other artifacts.

Journal Article↗

PubMed1980

Serial measurements of left ventricular dimensions by echocardiography. Assessment of week-to-week, inter- and intraobserver variability in normal subjects and patients with valvular heart disease.

The week-to-week, inter- and intraobserver variation in left ventricular echocardiographic measurements has been studied in 10 normal male volunteers and in five patients with stable valvular disease. A two-way analysis of variance showed no statistically significant variation either from week to week or between observers. Furthermore the within observer variation was minimal. Calculation of the coefficient of variation allowed confidence limits to be applied to each of the six ventricular measurements, thus providing ranges of variation in follow-up studies using M-mode echocardiography.

Aged↗

PubMed1985

The role of cerebral blood volume changes in brain specific-gravity measurements.

Cerebral blood volume (CBV) was calculated in gerbils from specific-gravity (SG) changes between normal and saline-perfused brains. Furthermore, changes in CBV were investigated during ischemia using carbon-14-labeled dextran (MW 70,000) as an intravascular marker. Both data were used to evaluate the possible error due to a change in CBV on the measurement of ischemic brain edema by the SG method. The methodological error found was 0.0004 for a 100% CBV change. This error is insignificant, being less than the standard deviation in the SG measured for the gerbil cortex (SG 1.0494 +/- 0.0006). Thus, CBV changes are not responsible for the SG variations observed during the first phase of ischemia. These variations are better explained as an increase of brain water content during ischemia.

Animals↗

PubMed1999

Reliability of Semmes Weinstein monofilament and ballpoint sensory testing, and voluntary muscle testing in Bangladesh.

The reliability of methods of testing nerve function is important, since diagnostic decision making is a direct function of the quality of the test. Three methods of nerve function testing were investigated at the Danish Bangladesh Leprosy Mission (DBLM) in north Bangladesh, and assessed for inter-observer reliability. The three methods were 1) ballpoint pen test (BPT) for sensory function; 2) graded Semmes Weinstein monofilament test (SWM) for sensory function and 3) voluntary muscle testing (VMT) for motor function. The weighted kappa (kappa w) statistic was used to express inter-observer reliability. Using this statistic, 0 represents agreement no better than random, and 1.0 complete agreement. kappa w values of > or = 0.80 are reckoned to be adequate for monitoring and research. Fifty-three patients were tested, a Senior physiotechnician acting as 'gold standard' against whom four other staff physiotechnicians were assessed. All three testing methods were found to have minimal inter-observer variation, with the kappa w for inter-observer agreement using BPT being 0.86, the SWM 0.92, and VMT 0.94. It is concluded that in trained and experienced hands, all three methods are reliable and repeatable to a level allowing confident use of results obtained in monitoring and research.

Bangladesh↗

PubMed2001

Surveillance programs for early stage non-seminomatous testicular cancer: a practice guideline.

BACKGROUND AND PURPOSE: To identify an appropriate surveillance program for men with clinical stage I non-seminomatous germ cell tumors of the testis (NSGCT). MATERIALS AND METHODS: A systematic review of the published literature was combined with a consensus process, around the interpretation of the evidence in the context of conventional practice, to develop an evidence-based practice guideline. RESULTS: No randomized controlled trials (RCTs) comparing surveillance schedules were found, but data from 12 case series and one RCT which compared radiotherapy with surveillance were reviewed. Variations in the schedules were not associated with observed variations in relapse, salvage, or survival rates. CONCLUSIONS: Men with clinical stage I testicular cancer, as defined by a normal physical examination, normal radiological scans (computed tomography [CT]) and serum markers (alpha-fetoprotein [AFP] and beta-subunit of human chorionic gonadotropin (betaHCG) which are normal or fall within normal limits during their expected half-lives, are eligible for surveillance. A recommended surveillance schedule is as follows: 1) Physical examination, blood serum marker tests (AFP and HCG), and chest x-rays should be conducted every month in the first year, every 2 months in the second year, every 3 months in the third year, and every 6 months in the fourth and fifth years; and 2) CT scans of the abdomen and pelvis should be conducted every 3 months in the first year, every 4 to 6 months in the second year and every 6 months in the third year, and once a year in the fourth and fifth year.

Germinoma↗

PubMed1992

[Coenzyme Q10: contractile dysfunction of the myocardial cell and metabolic therapy].

Coenzyme Q10, a mitoquinone involved in mitochondrial energy synthesis and the removal of free radicals, may be lacking in a number of cardiac pathologies leading to reduced contractile activity. The administration of exogenous coenzyme Q10 may help to improve contractile activity. In order to assess this hypothesis 63 patients suffering from altered myocardial contractile function (29 dilated cardiopathies, 15 valvular cardiopathies, 19 ischemic cardiopathies) which presented a NYHA class above 2 were selected. The study was open and patients were subdivided into two groups, one of which received conventional therapy alone whereas the other also received exogenous coenzyme Q10. After 4 months of follow-up clinical (NYHA class, effort tolerance) and echocardiographical (ventricular diameter and contraction fraction %) parameters were evaluated. In those patients treated with coenzyme Q10 and suffering from dilated cardiomyopathy a significant reduction in the NYHA class and a marked improvement in echocardiographic parameters were observed at the end of this period. The variations observed in other groups of patients treated were less conspicuous and not always statistically significant. The results of this study confirm that the association of coenzyme Q10 and conventional therapy may lad to a marked improvement in contractile function and correlated clinical conditions.

Adult↗

PubMed1998

[Life situation as a reason for sick leave].

The variation in general morbidity can not explain the observed variation in the incidence of sickness certification. 91% of patients who ask for a medical certificate for sick leave are granted the request, and it has been claimed that doctors often issue medical certificates because of the patients' social problems rather than their illness. We used a questionnaire to perform a survey of 1,401 consecutive adult patients who visited 89 general practitioners. 218 patients stated that they were given a medical certificate for sick leave. In 48 (22%) of these patients the doctors assessed that social and occupational factors influenced their decision to issue a medical certificate. In 34 patients occupational problems were stated as the reason, in five patients non-occupational problems, and in nine a combination of the two. According to the doctors, social problems were rarely the only reason for their issuing medical certificates for sick leave.

Adult↗

PubMedDate not supplied

[Clinicopathologic characteristics and distribution of number of autopsies of patient death due to coccidioidomycosis at a referral hospital in northeastern México].

AIMS: 1. To describe clinical and pathologic characteristics of patients with coccidioidomycosis (CM) who died from 1983-2000 at a hospital in northeastern Mexico, and 2, to know distribution of number of deaths due to CM per year and month. METHODS: From 4598 autopsies, 31 cases of CM were selected. Clinical chart and autopsy protocols were examined. Distribution of cases was analyzed by contingence table and Kolmogorov-Smirnov tests. RESULTS: There were 10 women and 21 men (aged 4 months to 60 years). In women, pregnancy was present in 40% of cases. In men, chronic renal failure (CRF) (38%) and AIDS (19%) were the pathologic conditions most frequently observed. Variation in distribution of cases throughout 18 years was not observed (p > 0.05). CONCLUSIONS: Mortality due to CM was 0.67% and variation in number of deaths was not found. In this endemic area, CM must be included in differential diagnosis of patients with risk factors such as pregnancy, CRF, and AIDS, especially if associated with pneumonia with miliary pattern or septicemia with splenomegaly.

Adolescent↗

PubMed1994

Observer variability in measuring elevation and external rotation of the shoulder. Primary Care Rheumatology Society Shoulder Study Group.

The aim of the study was to assess the observer variation between trained primary care physicians in their assessment of two key shoulder movements: elevation and external rotation. Six observers each examined and recorded their visual estimate of the range of movements in six patients assessed in random order. There was good agreement on the range of passive elevation assessed to the start of pain (if present): intraclass correlation coefficient (ICC) = 0.84, and to the point of maximum elevation: ICC = 0.95. There was no evidence of an important systematic bias between observers. By contrast, external rotation was poorly reproducible: ICC = 0.43, with important systematic differences between observers. In the second experiment, six observers simultaneously witnessed a range of movements in a single volunteer subject, and the agreement on their visual estimation of the angles achieved was assessed. There was a marked reduction in the systematic bias in external rotation, but agreement was still poor. Agreement for elevation remained high with a reduction in the small amount of bias observed in the first experiment when variability in both examination and visual assessment had been investigated. We conclude that shoulder elevation is a reliable measurement for use in multicentre studies by trained primary care physicians. By contrast, external rotation is poorly reproducible because of systematic variation in examination technique and random variation in visual assessment.

Female↗

PubMed2001

Neonatal chest and abdominal radiation dosimetry: a comparison of two radiographic techniques.

Radiographs of the chest and the abdomen are the most commonly requested diagnostic X-ray examinations undertaken in neonatal intensive care units. Frequently, for a single child, both radiographs are requested simultaneously. These images can be obtained either as two separate exposures (one of the chest and one of the abdomen), or as a single exposure to include both anatomical regions on one film. This study compared the effective dose imparted as a result of each technique. A neonatal anthropomorphic phantom was designed and constructed, and each radiographic technique was simulated. Entrance surface dose (ESD) and dose-area product (DAP) were measured and estimates of effective dose were made from the DAP values. The mean effective dose for the separate exposure technique was estimated to be 37.3 microSv compared with 35.5 microSv for the combined exposure technique. However, observed variations in field size gave rise to uncertainties in DAP and thus the effective doses estimated from it. Hence, no significant difference in effective dose was observed between the radiographic techniques. The observed coefficient of variation in field size (16% for a 2.5 kg neonate) demonstrates that good standards of radiographic practice are more important than choice of technique.

Equipment Design↗

PubMed2004

The demographic and social class basis of inequality in self reported morbidity: an exploration using the Health Survey for England.

STUDY OBJECTIVES: To assess the relative contribution of age and social class to variations in the prevalence of a selection of self reported health problems. To examine the implications of observed variations for research on health inequalities. DESIGN: Secondary analysis of the Health Survey for England (1991-1997) using morbidities that are particularly prone to class effects. A statistical measure of the "relative class effect" is introduced to compare the effects of adjusting for social class and age. MAIN RESULTS: There is substantial variation in the relative importance of the age and class distributions of different diseases. Age effects often overshadow those of class even for conditions where an apparently strong social gradient exists. Only for self reported mental health among women does the social gradient exceed the age gradient. Within the context of a dominating age gradient, social gradients are relatively high for mental health and general health for both sexes. Variation in the relative strengths of the social gradients between the sexes are observed for angina symptoms. CONCLUSIONS: Given variations in the "relative class effect", analysis recognising the distinct contributions of age, sex, and social class to specific morbidities is advocated as a transparent and robust approach to the assessment of morbidity based inequality.

Adolescent↗

PubMed2001

The use of computed tomography to define zygomatic complex position.

PURPOSE: The purpose of this study was to analyze the use of midline references and landmarks to assess the position of the zygomatic complex relative to the cranial base, and to test the reliability of these measurements in assessing facial symmetry. METHODS: Direct skull measurements were compared with measurements made on computed tomography (CT) images. The effect of CT scanner error, technologist error, gantry angle error, error of skull inclination, and error due to the presence of titanium rigid fixation hardware were assessed. To test observer variation and the effect of each level of error, 4 blinded bilateral measurements were repeated 3 times by 5 observers on both dry skull and CT scans. A mixed effect analysis of variance model then assessed for effect of method of measurement (dry skull vs CT), observer, CT scanner, technologist, gantry angle, skull inclination, and rigid fixation. RESULTS: A total of 2,040 measurements were made. Measurements for zygomatic complex posterior and anterior width and height were reliable and had an interobserver variations of 0.02 +/- 0.03 mm, 0.5 +/- 0.4 mm, and 0.37 +/- 0.3 mm, respectively. The difference between dry skull and CT assessment for the 3 reliable measurements was 1.2 +/- 0.3 mm, 0.44 +/- 0.4 mm, and 1.1 +/- 0.5 mm, respectively. The errors produced by the CT scanner, technologist, and rigid internal fixation hardware were not clinically significant. The measurements were not sensitive to gantry angle and skull inclination changes of 10 degrees or less. A fourth measurement assessing zygomatic complex projection was found not to be accurate or reliable. CONCLUSIONS: These findings suggest that the 3 CT scan measurements describing the position of the zygomatic complex relative to the cranial base are clinically useful.

Cephalometry↗

PubMed1982

Observer variability in grading patients with subarachnoid hemorrhage.

The management of individual patients with subarachnoid hemorrhage depends greatly on assessment of the patient's clinical condition. Difficulty in applying current grading systems prompted the authors to conduct studies of observer variability and to attempt to identify sources of inconsistency. Observers graded 15 patients by both the Hunt and Hess and Nishioka systems. Considerable observer variability was found, with up to four different grades being selected for the same patient. Kappa statistics were used to evaluate the data. This method determines observer agreement occurring in excess of chance. Kappa values for each grading system showed observer agreement to be significantly better than chance, yet revealed marked observer variation. Most variation occurred when Grade 3 was selected, irrespective of the system used. In a further study where observers graded clinical summaries, similar variation occurred; therefore, inconsistency was due mainly to difficulty in matching patients with levels described in the grading system, rather than to fluctuation in the patient's clinical condition or difference in the observers' examination technique. Variability was high when patients with systemic disease or vasospasm on angiography were graded with the Hunt and Hess system. The studies show that a simpler and more reliable grading system is required, and emphasize and need for caution when interpreting the results from different published series.

Adult↗