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PubMed2006

A 30 year perspective of the quality of evidence published in 25 clinical journals: signs of change?

METHODS: The quality of clinical studies published in five different specialties, over three decades was evaluated. Computerised search of the Medline database was undertaken to evaluate the articles published in 25 clinical journals in 1983, 1993, and 2003 from five different specialties (medicine, surgery, paediatrics, anaesthesia, and psychiatry). The number of randomised controlled trials (RCTs), meta-analyses, and other clinical trials (non-RCT) were noted. RESULTS: From the 27,030 articles evaluated, there were 2283 (8.4%) RCTs, 166 (0.6%) meta-analyses, and 4153 (15.4%) other clinical trials. For the proportion of RCTs, the rank order of the specialties was; anaesthesia (503; 18%), psychiatry (294; 9.6%), medicine (899; 8.1%), paediatrics (326; 6.4%), and surgery (261; 5.3%) (p<0.001). For the proportion of meta-analysis, the rank order of the specialties was; psychiatry (36; 1.2%), medicine (105; 0.9%), paediatrics (15; 0.3%), anaesthesia (6; 0.2%), and surgery (4; 0.1%) (p<0.001). Overall, from 1983 to 2003, there were increases in the proportion of RCTs (449, 5.9% to 1027, 9.6%), meta-analysis (0, 0% to 127, 1.2%), and other clinical trials (897, 12% to 1983, 19%) (p<0.001). This trend was apparent in each clinical specialty (p<0.001). CONCLUSIONS: Over the three decades evaluated, clinical trials, notably RCTs and meta-analysis form only a small proportion of articles published in prominent journals from five clinical specialties. This is notwithstanding the modest increases in the proportions of RCTs and meta-analysis over the same period.

Consensus↗
PubMedDate not supplied

Effect of dentifrice containing fluoride and/or baking soda on enamel demineralization/remineralization: an in situ study.

The additive effect of baking soda on the anticariogenic effect of fluoride dentifrice is not well established. To evaluate it, a crossover in situ study was done in three phases of 28 days. Volunteers, using acrylic palatal appliances containing four human enamel blocks, two sound (to evaluate demineralization) and two with artificial caries lesions (to evaluate remineralization), took part in this study. During each phase, 10% sucrose solution was dripped (3 times a day) only onto the sound blocks. After 10 min, a slurry of placebo, fluoride (F) or fluoride and baking soda (F+NaHCO(3)) dentifrice was dripped onto all enamel blocks. The results showed a higher F concentration in dental plaque formed during treatment with F+NaHCO(3) than placebo (p<0.05), but the difference related to F dentifrice was not significant. The enamel demineralization was lower, and remineralization was greater, after treatment with F+NaHCO(3) than placebo (p<0.05), but the difference related to F dentifrice was not significant. The data suggest that baking soda neither improves nor impairs the effect of F dentifrice on reduction of demineralization and enhancement of remineralization of enamel.

Buffers↗
PubMedDate not supplied

Cariogenic potential of lactosylfructoside as determined by acidogenicity of oral streptococci in vitro and human dental plaque in situ.

The cariogenic potential of lactosylfructoside [O-beta-D-galactopyranosyl-(1-->4)-O-alpha-D-glucopyranosyl-(1<-->2)-beta-D-fructofuranoside] was estimated by experiments on oral streptococci in vitro and human dental plaque in situ. Lactosylfructoside was unable to support growth of the strains of Streptococcus mutans and S. sobrinus used in this study. However, it was able to support growth of strains of S. sanguis, S. mitis and S. oralis. Acid was produced rapidly by cell suspensions of S. oralis ATCC 10557 incubated with lactosylfructoside. Application of 5% w/v solution decreased the pH of human dental plaque. The minimum pH value was below 5.3. The results suggest that lactosylfructoside is as acidogenic as lactose and could be cariogenic if it is consumed frequently and retained for a long period in the mouth.

Acids↗
PubMedDate not supplied

Comparison between visual examination and a laser fluorescence system for in vivo diagnosis of occlusal caries.

This study compared a laser fluorescence (LF) system (DIAGNOdent) with a visual caries scoring system for in vivo detection and diagnosis of occlusal caries under the conditions of an epidemiological study, in 132 mandibular and 38 maxillary first permanent molars in 170 children (mean age: 6.85 +/- 0.58 years). The teeth were cleaned and occlusal caries status in a selected investigation site recorded using both visual and LF systems. The LF readings were interpreted both according to the cut-off points recommended by the manufacturers and those based on laboratory research with histological validation. The percentage agreement of the LF and visual scoring system was better using the cut-off limits recommended by the manufacturer. Histological validation was not possible in this clinical study, but it appeared that either the LF method was overscoring some lesions or the visual method was underscoring them. Since the LF instrument cannot be expected to differentiate caries from hypomineralisation, it should probably be used as an adjunct to a clinical examination.

Child↗
PubMedDate not supplied

Total fluoride intake and urinary excretion in German children aged 3-6 years.

There have only been few investigations comparing total fluoride intake and the fluoride proportion excreted in urine in pre-school children. In addition, the results of available studies are conflicting. Total fluoride intake was assessed in 11 healthy children aged 3-6 years on 2 consecutive days and urinary fluoride excretion was determined. The duplicate-diet approach was used for the assessment of fluoride intake from solid and liquid foods. Fluoride intake from toothbrushing was calculated as the difference between the amount of fluoride in the paste put on the toothbrush and the drinking water (fluoride concentration 0.25 mg/l) used for rinsing vs. the fluoride amounts recovered in the toothpaste spat out and in the rinsing water. Use of fluoridated domestic salt and/or fluoride tablets was recorded. The children's intake of fluoride from food averaged 202.5+/-116.2 microg F/day. They swallowed an average amount of 273.9+/-175.6 microg F/day when brushing their teeth. Daily fluoride ingestion from all sources totalled 930.7+/-391.5 microg or 53.0+/-21.4 microg/kg body weight. On average 51.5% of the fluoride ingested was excreted in urine. The wide interindividual variation makes it necessary to evaluate the urinary excretion rate for fluoride in larger study populations with varied fluoride exposure.

Body Weight↗
PubMedDate not supplied

Clinical investigation of two glass-ionomer restoratives used with the atraumatic restorative treatment approach in China: two-years results.

OBJECTIVE: To compare the clinical performance of two glass-ionomer cements, ChemFlex (Dentsply DeTrey) and Fuji IX GP (GC), when used with the atraumatic restorative treatment (ART) approach in China. METHODS: Eighty-nine school children aged between 6 and 14 years who had bilateral matched pairs of carious posterior teeth were included. A split-mouth design was used in which the two materials were randomly placed on contralateral sides. The performance of the restorations was assessed directly and also indirectly from die-stone replicas at baseline and after 6, 12, and 24 months. RESULTS: The 24-month cumulative survival rates of ART restorations in the primary teeth were 93 and 90% for the ChemFlex and Fuji IX GP class I restorations, respectively, while 40 and 46% of class II restorations placed with the respective materials were satisfactory. In the permanent dentition, only class I restorations were involved and the cumulative survival rates were 95 and 96% for ChemFlex and Fuji IX GP. For the primary teeth after 24 months, net mean occlusal wear was 87 microm for ChemFlex and 85 microm for Fuji IX GP. The occlusal wear in the permanent teeth was 75 microm for ChemFlex and 79 microm for Fuji IX GP. CONCLUSION: The clinical performance of both materials over a 24-month period was similar and the survival rates of class I ART restorations in both primary and permanent teeth were high.

Adolescent↗
PubMed2004

Antioxidant status in acute stroke patients and patients at stroke risk.

BACKGROUND AND PURPOSE: Antioxidant enzymes like copper/zinc superoxide dismutase (SOD), catalase and gluthatione peroxidase (GSHPx) are part of intracellular protection mechanisms to overcome oxidative stress and are known to be activated in vascular diseases and acute stroke. We investigated the differences of antioxidant capacity in acute stroke and stroke risk patients to elucidate whether the differences are a result of chronic low availability in arteriosclerosis and stroke risk or due to changes during acute infarction. METHODS: Antioxidant enzymes were examined in 11 patients within the first hours and days after acute ischemic stroke and compared to risk- and age-matched patients with a history of stroke in the past 12 months (n = 17). Antioxidant profile was determined by measurement of glutathione (GSH), malondialdehyde (MDA), SOD, GSHPx and minerals known to be involved in antioxidant enzyme activation like selenium, iron, copper and zinc. RESULTS: In comparison to stroke risk patients, patients with acute ischemic stroke had significant changes of the GSH system during the first hours and days after the event: GSH was significantly elevated in the first hours (p < 0.01) and GSHPx was elevated 1 day after the acute stroke (p < 0.05). Selenium, a cofactor of GSHPx, was decreased (p < 0.01). GSHPx levels were negatively correlated with National Institutes of Health Stroke Scale (NIHSS) scores on admission (r = -0.84, p < 0.001) and NIHSS scores after 7 days (r = -0.63, p < 0.05). MDA levels showed a trend for elevation in the first 6 h after the acute stroke (p = 0.07). No significant differences of SOD, iron, copper nor zinc levels could be identified. CONCLUSIONS: Differences of antioxidant capacity were found for the GSH system with elevation of GSH and GSHPx after acute stroke, but not for other markers. The findings support the hypothesis that changes of antioxidant capacity are part of acute adaptive mechanisms during acute stroke.

Aged↗
PubMed2004

Sensation seeking, sexual curiosity and testosterone in inmates.

The relationships between sensation seeking, curiosity about sex, and total and free testosterone in inmates were investigated. The role of other hormones such as luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex hormone-binding globulin (SHBG) in these relationships was also analyzed. Previous analysis allowed the deletion of extreme hormone values affecting the distribution of the variables. In spite of obtaining a high mean for SHBG, relationships between hormones were appropriate. It was observed that higher values of SHBG produce an increment in total testosterone, but not in free testosterone. Positive relationships between total testosterone and the Disinhibition scale of the Sensation Seeking Scale Form V were replicated, although they were affected by SHBG. Significant relationships between total and free testosterone and curiosity about sex were also found. LH and FSH did not influence these patterns of relations. It was suggested that relationships between SHBG and sensation seeking in inmates could be mediated by items referring to alcohol and drugs. The high levels of SHBG observed in the sample reinforced this suggestion. In spite of the role of SHBG, subjects who were desinhibited and concerned about sex presented higher concentrations of total and free testosterone. The results support Zuckerman's sensation seeking theory.

Adult↗
PubMed2007

Effects of calcium on the erosive potential of acidic candies in saliva.

Theoretical calculations have shown that acidic candies may be potentially erosive upon consumption. However, little is known about the protective effect of adding calcium to potentially erosive candies and about the protective effects of saliva that cannot be fully accounted for by theoretical calculations. Therefore, the aims of this study were to (1) determine the erosive potential of acidic candies with and without calcium and (2) to determine differences between theoretically calculated erosive potential and actual erosive potential in saliva. Twenty healthy test persons sucked acidic candy with and without calcium while their whole saliva was collected into a closed system at different times: baseline, candy-stimulated, and post-stimulated. The erosive potential of the candy was evaluated from candy-induced changes in saliva degree of saturation with respect to hydroxyapatite (HAp) and directly by dissolution of HAp crystals in candy-stimulated saliva. The results showed that similar salivary stimulation was obtained with both candies. The modified candy released more than 13 mmol/l of calcium into saliva, resulting in a lower critical pH, and considerably lower erosive potential than the control (p < 0.001). Although a significant correlation was obtained between theoretical calculation of DS(HAp) and dissolution of HAp crystals (r(s) = 0.65; p < 0.001), many samples obtained by sucking modified candy showed no signs of HAp dissolution in spite of being undersaturated. We conclude that saturation levels and critical pH may not fully reflect when dental erosion is expected to occur in saliva and that calcium addition reduces the erosive potential of acidic candies.

Adult↗
PubMed2002

Advice on statistical analysis for Circulation Research.

Since the late 1970s when many journals published articles warning about the misuse of statistical methods in the analysis of data, researchers have become more careful about statistical analysis, but errors including low statistical power and inadequate analysis of repeated-measurement studies are still prevalent. In this review, several statistical methods are introduced that are not always familiar to basic and clinical cardiologists but may be useful for revealing the correct answer from the data. The aim of this review is not only to draw the attention of investigators to these tests but also to stress the conditions in which they are applicable. These methods are now generally available in statistical program packages. Researchers need not know how to calculate the statistics from the data but are required to select the correct method from the menu and interpret the statistical results accurately. With the choice of appropriate statistical programs, the issue is no longer how to do the test but when to do it.

Analysis of Variance↗
PubMed2004

Estimating the temporal interval entropy of neuronal discharge.

To better understand the role of timing in the function of the nervous system, we have developed a methodology that allows the entropy of neuronal discharge activity to be estimated from a spike train record when it may be assumed that successive interspike intervals are temporally uncorrelated. The so-called interval entropy obtained by this methodology is based on an implicit enumeration of all possible spike trains that are statistically indistinguishable from a given spike train. The interval entropy is calculated from an analytic distribution whose parameters are obtained by maximum likelihood estimation from the interval probability distribution associated with a given spike train. We show that this approach reveals features of neuronal discharge not seen with two alternative methods of entropy estimation. The methodology allows for validation of the obtained data models by calculation of confidence intervals for the parameters of the analytic distribution and the testing of the significance of the fit between the observed and analytic interval distributions by means of Kolmogorov-Smirnov and Anderson-Darling statistics. The method is demonstrated by analysis of two different data sets: simulated spike trains evoked by either Poissonian or near-synchronous pulsed activation of a model cerebellar Purkinje neuron and spike trains obtained by extracellular recording from spontaneously discharging cultured rat hippocampal neurons.

Action Potentials↗