PubMed Health⌕ Search

Biomedical subjects

H Lorentzen

Publications and source records attributed to H Lorentzen.

8 recordsLinked to original sources
PubMed1999

The dermatoscopic ABCD rule does not improve diagnostic accuracy of malignant melanoma.

The dermatoscopic ABCD rule has been suggested to improve diagnostic performance regarding cutaneous malignant melanoma. Using this rule, a total dermatoscopy score is calculated from the presence of various dermatoscopic elements. A total dermatoscopy score above 4.75 signifies possible and 5.45 probable melanoma. We compared the diagnostic accuracy of dermatoscopy with and without the use of the ABCD rule. Furthermore, receiver operating characteristic analysis was performed for the ABCD rule. The area under the receiver operating characteristic curve was 0.854 (range 0.777-0.906) demonstrating that in 85.4% of the cases, cutaneous malignant melanomas were rated higher than the non-melanoma skin lesions. Sensitivity for the melanoma diagnosis was higher for simple dermatoscopy than when the ABCD rule was used (p<0.05). There was no difference in specificity when a total dermatoscopy score of 4.75 was used as cut-off point, but specificity was lower for simple dermatoscopy than when the total dermatoscopy score of 5.45 was used. Diagnostic accuracy was higher for simple dermatoscopy than for the ABCD rule (p<0.01). In conclusion, the dermatoscopic ABCD rule was not superior to simple dermatoscopy, and fewer malignant melanomas were identified with this rule.

Biopsy, Needle↗
PubMed1999

Clinical and dermatoscopic diagnosis of malignant melanoma. Assessed by expert and non-expert groups.

We investigated the nosographic and diagnostic probabilities and likelihood ratios of dermatoscopy in order to evaluate the method's role in decision-making regarding melanoma. Clinical slides and dermatoscopic photos were obtained from 232 patients referred for dermatoscopy. Four dermatoscopy "experts" and 5 "non-experts" assessed the slides. Diagnoses were compared with histopathology. Sensitivity of the clinical assessments was 0.78 vs. 0.69 ("experts" vs. "non-experts"), sensitivity of dermatoscopy assessment was 0.83 vs. 0.69 (p = 0.04). The expert group demonstrated increased specificity (from 0.89 to 0.94) when applying dermatoscopy compared with clinical assessment alone (p=0.03). Positive likelihood ratios were doubled in the "expert group" and the negative likelihood ratios improved 25% with dermatoscopy compared with clinical assessment.

Data Interpretation, Statistical↗
PubMed1997

[Medication errors in a pediatric department].

In a prospective study, iatrogenic medication errors were registered among paediatric admissions. The two most common causes of incidents were neglecting to give a medication on schedule and administration of an incorrect dose-but extra dose errors, errors of omission, wrong rate errors and administration of unauthorized drugs also occurred. After implementation of a satellite pharmacy, medication error rates were compared, and a reduction of the more serious and potentially harmful incidents was shown.

Denmark↗
PubMed1996

Gentamicin concentrations in human subcutaneous tissue.

Wound infections frequently originate from the subcutaneous tissue. The effect of gentamicin in subcutaneous tissue has, however, normally been evaluated from concentrations in blood or wound fluid. The aim of the present study was to investigate the pharmacokinetic properties of gentamicin in human subcutaneous adipose tissue by a microdialysis technique. Seven healthy young volunteers each had four microdialysis probes placed in the fat (subcutaneous) layer of the abdominal skin. After the administration of a 240-mg gentamicin intravenous bolus, consecutive measurements of the drug concentrations in serum and subcutaneous interstitial fluid were obtained simultaneously for 6 h. The tissue gentamicin concentration peaked after 10 to 30 min. The peak concentration in the tissue was 6.7 +/- 2.0 mg.liter-1 (standard deviation), equivalent to 39.1% of the peak concentration in serum. The area under the concentration-versus-time curve for the first 6 h in the tissue was 1,281 +/- 390.0) mg.min liter-1, equivalent to 59.7% of the area under the concentration-versus-time curve in serum. It is concluded that the microdialysis technique can be used to make dynamic and quantitative measurements of the gentamicin concentration in human subcutaneous tissue. In this adipose tissue, the peak concentrations of gentamicin were approximately seven times the MIC for Pseudomonas aeruginosa and 33 times the MIC for Staphylococcus aureus after the administration of an intravenous bolus of 240 mg, indicating the presence of sufficient concentrations in the adipose tissue to be effective against common bacteria.

Adipose Tissue↗
PubMedDate not supplied

Comparison of dermatoscopic ABCD rule and risk stratification in the diagnosis of malignant melanoma.

For didactic and documentation purposes the dermatoscopic ABCD rule and the dermatoscopic risk stratification have been proposed. The aim of this investigation was to compare the ability of the 2 methods to separate patients with cutaneous malignant melanoma from individuals with other pigmented skin lesions. Three dermatologists, experienced users of dermatoscopy, assessed macroscopic clinical and dermatoscopic slides from 258 patients referred to the skin cancer outpatient clinic by the ABCD rule and risk stratification methods. Diagnostic performance of the 2 methods was compared by receiver operating characteristics curve analysis. When all pigmented skin lesions were compared, there was a trend for the observers to perform better using risk stratification. When only lesions with a well-defined pigment network were included, the diagnostic performance of the risk stratification method was superior to the dermatoscopic ABCD rule (areas under the receiver operating characteristics curve median 0.93 vs. 0.80, p<0.004) for all observers. The agreement between the 2 methods was moderate to substantial (kappa coefficient 0.53-0.62). More melanomas were identified when the rules were combined. The dermatoscopic ABCD rule has been accepted as a standard for identifying melanomas with the dermatoscope, but should be considered secondary to pigment network analysis.

Biopsy, Needle↗