Search PubMed⌕ Search

Biomedical subjects

M Steiner

Publications and source records attributed to M Steiner.

At least 181 records · Page 10Linked to original sources
PubMed1994

Fluoride varnishes (Duraphat): a meta-analysis.

In the present article we analyze a series of studies designed to detect the caries preventive effect of Duraphat by means of meta-analysis. Meta-analysis is a collection of statistical methods designed to investigate and to summarize a series of investigations. It may be a valuable tool to complement traditional narrative reviews. During the last years meta-analysis has attracted increasing interest in sociology, psychology and medicine. In order to find previous studies concerned with the clinical effects of Duraphat we applied a systematic literature search. Papers were included independent of results when they fulfilled a checklist of well defined methodological selection criteria. In order to aggregate the results of the Duraphat-studies we used different complementary statistical approaches: Firstly, the so-called file drawer problem is considered. This may help to get a better insight into the problem of underreporting non-significant results or publication bias. It was found to be very unlikely that underreporting of non-significant results could reverse the conclusion into an overall null-result. After that, the inhomogeneity between studies is investigated. The overall variation of caries reduction R is separated into two components: A between study component of variance and a variance pertaining to the individual studies (random effects model). It was found that the overall variation is dominated by the between studies variation and not by the sampling variation. Due to the pronounced variation between studies the confidence interval of the overall effect size (R = 0.38) is quite large (95%-Cl: 0.19-0.57).(ABSTRACT TRUNCATED AT 250 WORDS)

Bias↗
PubMed1994

A note concerning the caries preventive effect of Duraphat.

In a previous article (1) we analyzed a series of eight studies concerned with the effect of Duraphat in the prevention of dental caries by means of meta-analysis. A random effects model was used to estimate an overall effect size of caries reduction R and the corresponding confidence interval. In the present short communication we complement this previous study by neglecting the within study variation to the overall variation which is dominated by between study variation. This allows us to include a larger number of studies and thus make fuller use of the available information. We estimate nonparametrical confidence intervals for effect sizes (caries reduction) by means of the "bootstrap method". The overall caries reduction R on permanent teeth (14 studies) was estimated to be: R = 0.38 (95%-CI: 0.25-0.50).

Confidence Intervals↗
PubMed1994

Standardized protocols for condom breakage and slippage trials: a proposal.

In the absence of well-controlled studies on the clinical effectiveness of condoms against pregnancy and sexually transmitted diseases, breakage and slippage data may provide the best indication of the protection offered by condom use. According to the recent literature, condom breakage rates range from 0% to 12%, with many US studies falling in the 2% to 5% range. Few studies have collected slippage data. In addition to discussing methodological issues associated with these studies, we propose a standardized protocol for future condom breakage and slippage trials and discuss how results may be used to estimate perfect-use and typical-use pregnancy rates.

Condoms↗
PubMed1994

Increased levels of soluble adhesion molecules in type 2 (non-insulin dependent) diabetes mellitus are independent of glycaemic control.

Patients with Type 2 (non-insulin dependent) diabetes mellitus are at increased risk of thrombosis and the premature development of atherosclerosis. This may be related to damage to the endothelium (which may be the primary target tissue for the disease process) resulting from a loss of normal glycaemic metabolic control. Thus changes in endothelial cell function, such as modified release of soluble leukocyte and platelet adhesion molecules, may be important. Accordingly, E-selectin, von Willebrand factor (vWf), vascular cell adhesion molecule (VCAM) and intercellular adhesion molecule (ICAM) were measured in serum from 60 patients and 76 controls. Raised levels of vWf (p = 0.0002), E-selectin (p < 0.0001) and VCAM (p = 0.003) in patient's samples failed to correlate with glycaemic control as assessed by levels of fructosamine and glycated haemoglobin, or with 24 h urine albumin. Levels of ICAM were not increased in our patients. Levels of the two endothelial cell products, vWf and E-selectin, failed to correlate although E-selectin correlated with low density lipoprotein cholesterol (p = 0.016). vWf correlated with VCAM (p < 0.001) and hypertension (p = 0.032). We conclude that levels of soluble adhesion molecules vWf, E-selectin and VCAM are raised in Type 2 diabetes mellitus. The mechanisms for these changes appear to be independent of glycaemic control but may relate to concurrent hypertension and/or hypercholesterolaemia.

Aged↗
PubMed1994

Caries prevalence in Switzerland.

The first Swiss studies of DMFT counts were undertaken in the late 1950s and showed values of 7.7-11.3 for children of 12 years of age and 12.6-18.6 for children of 15 years of age. Although these studies did not use current statistical sampling methods, and so are not directly comparable, the results of the most recent surveys do present a startling contrast. In 1992, DMFT figures had fallen to an average of 1.12 and 2.22 DMFT in 12- and 15-year-olds respectively. Reasons for these sharp declines are discussed, as are the available figures for adults over the same period of time. Predictions are made for DMFT levels for the year 2008 and their likely impact on dental services.

Adolescent↗
PubMed1994

[Spontaneous, massive liver hemorrhage as a complication of thrombolysis with ultra-high dose streptokinase in deep thrombophlebitis].

We report on a rare case of spontaneous, life-threatening liver bleeding as a major complication of thrombolysis using short-term, ultrahigh streptokinase in deep venous thrombosis. The event occurred in a female patient (age 40 years) who presented no contraindication to thrombolytic therapy. Intraabdominal bleeding was suspected during intravenous streptokinase infusion. Emergency laparotomy revealed four liter of unclotted blood resulting from two ruptured subcapsular liver haematomas. Local haemostasis was achieved and the integrity of the liver restored. Multiple transfusions of red blood cells, fresh frozen plasma and fibrinogen were given. The postoperative period was uneventful and the patient recovered gradually. The patient could be discharged from the hospital in good health. Diagnostic and therapeutic approaches to this rare complication of thrombolysis are discussed. Additionally, a brief review of previously reported cases is provided.

Adult↗
PubMed1994

In situ flat embedding of monolayers and cell relocation in the acrylic resin LR white for comparative light and electron microscopy studies.

A simple and reliable method has been developed for the in situ LR White embedding of cell monolayers grown on glass cover-slips. Combined with cytochemical or immunological procedures, this technique allows light and/or electron microscopy investigations of a large number of cells in the same horizontal plane within a relatively short period of time. It can be applied to cells grown on microgrid finder cover-slips which allows a distinct site of even an individual cell of a monolayer to be studied at first at the light microscope level and subsequently at the electron microscope level. Hence, it is also suitable for controlling manipulation of single cells, followed by their serial sectioning after relocation in the electron microscope.

Acrylic Resins↗
PubMed1994

The use of logistic discrimination and receiver operating characteristics (ROC) analysis in dentistry.

Logistic regression is a statistical method which allows an investigator to 'explain' or 'predict' a binary response variable from a set of independent variables. In particular, it may be used to classify persons for example, as diseased or healthy, high risk or low risk etc. (logistic discrimination). During recent years this method has been of increasing interest and importance in dentistry. Since this demanding statistical method may not be easily accessible to dentists, a description is provided of its basic characteristics in an introductory and condensed form. A worked example, 'identification of children with high caries risk', is presented in order to demonstrate the application and use of the method. Following the presentation of the logistic model, evaluation of the performance of a classification model by means of 'receiver operating characteristic (ROC) analysis' is demonstrated. The presentation of these statistical tools here, puts more weight on verbal explanation and on graphical representations than on mathematical details. This statistical tools here, puts more weight on verbal explanation and on graphical representations than on mathematical details. This may help to make the methods accessible to readers who have insufficient time to study a more comprehensive discourse.

Child↗
PubMed1994

[The caries occurrence in schoolchildren of the city of Zurich in 1970-1993. A view of prevention in new immigrants].

Surveys of dental caries prevalence were carried out from 1970-1993 in schoolchildren of the city of Zurich. DMFT experience declined by 68 to 80%, while the average dmft decreased by 48-53% (ages 7 to 9). From 1988 to 1993, the average DMFT decreased further in the age group of 12- and 14-year-olds; in the ages 7 to 10, however, neither the DMFT nor the dmft showed a decline. In children who had of late immigrated, DMF levels were 2 to 3 times higher than in the children holding Swiss citizenship.

Adolescent↗
PubMed1994

[The caries occurrence in 7- to 12-year-old schoolchildren in Switzerland. The results of a country-wide survey 1987-89].

Between 1987 and 1989, a random sample of school children aged 7 and 12 years in Switzerland was drawn. In the first stage, districts were chosen. Within the districts, 12 children in the two specified age groups were selected. In addition, Switzerland was subdivided into two strata. The children of stratum 2 had consumed fluoridated salt since birth while those of stratum 1 had only done so during the preceding 4 to 5 years but had benefitted since the age of 5 to 7 from dental health education programs using fluorides at school. The oral examinations were carried out according to the methodology of the World Health Organization. Attendance was 94% (1115 children). 47% of the seven-year-old children were caries-free, and the average dmft was 2.20 (95% confidence limits at 1.87 and 2.52). The average dt was 1.06. These children had an average DMFT of 0.40, with 77% having DMFT = 0. At the age of 12, the average DMFT was 2.03, with confidence limits at 1.73 and 2.33. On average, they had 0.45 DT and 38% of them were caries-free (DMFT = 0). There were only minor differences between the 2 strata. These results agreed well with the data from 6 local surveys carried out during 1987 to 1989. When compared with the majority of European countries, caries experience of Swiss children was fairly low.

Age Distribution↗
PubMed1994

Neural connections of the suprachiasmatic nucleus and medial hypothalamus of the Syrian hamster (Mesocricetus auratus).

The neural connections of brain areas involved in the control of circadian rhythms were investigated in the Syrian hamster by observing the anterograde and retrograde neural labelling resulting from injections of HRP-WGA into the suprachiasmatic nucleus (SCN) and subparaventricular zone (SPZ). The neural connections of these 2 brain areas in the strongly photoperiodic hamster are very similar to those in the more weakly photoperiodic rat. Two differences were observed: (1) in the rat, but not in the hamster, the SCN projects to the ventral geniculate nucleus and intergeniculate leaflet of the thalamus; and (2) reciprocal contralateral neural connections appear to be more numerous in the hamster than in the rat SCN. These differences may relate to the differences in photoperiodic sensitivity of the 2 species.

Animals↗