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Biomedical subjects

A Pfahlberg

Publications and source records attributed to A Pfahlberg.

45 records · Page 3Linked to original sources

Diagnosis of Creutzfeldt-Jakob disease by measurement of S100 protein in serum: prospective case-control study.

OBJECTIVE: To analyse serum concentrations of brain specific S100 protein in patients with Creutzfeldt-Jakob disease and in controls. DESIGN: Prospective case-control study. SETTING: National Creutzfeldt-Jakob disease surveillance unit. SUBJECTS: 224 patients referred to the surveillance unit with suspected Creutzfeldt-Jakob disease and 35 control patients without dementia. MAIN OUTCOME MEASURE: Serum concentration of S100 protein in patients with Creutzfeldt-Jakob disease, in patients with other diseases causing dementia, and in the control group. RESULTS: Of the 224 patients with suspected Creutzfeldt-Jakob disease, 65 were classed as definitely having the disease after neuropathological verification, an additional 6 were classed as definitely having the disease as a result of a genetic mutation, 43 as probably having the disease, 36 as possibly having the disease, and 74 patients were classed as having other disease. In the 108 patients classed as definitely or probably having Creutzfeldt-Jakob disease the median serum concentration of S100 was 395 pg/ml (SD 387 pg/ml). This was significantly higher than concentrations found in the 74 patients classed as having other diseases (median 109 pg/ml; SD 177 pg/ml; P = 0.0001). At a cut off point of 213 pg/ml sensitivity for the diagnosis of the disease was 77.8% (95% confidence interval 68.8% to 85.2%) and specificity was 81.1% (70.3% to 89.3%). There was a significant difference in survival at different concentrations of S100 in Kaplan-Meier curves (P = 0.023). CONCLUSION: Measurement of serum concentrations of S100 is a valuable tool which can be used more easily than tests on cerebrospinal fluid in the differential diagnosis of Creutzfeldt-Jakob disease. More studies are needed to determine whether serial testing of serum S100 improves diagnostic accuracy.

Biomarkers↗

Prevalence and incidence of hand dermatitis in hairdressing apprentices: results of the POSH study. Prevention of occupational skin disease in hairdressers.

OBJECTIVE: Occupational skin changes in hairdressers are very common. Morbidity, however, has not yet been quantified precisely. METHODS: A cohort of 2,352 hairdressing apprentices (of the 2,570 invited to participate, i.e., 91.5% response) was prospectively followed for the duration of their vocational training (3 years) by three examinations. Three waves (years) were recruited in 1992, 1993, and 1994 from 15 vocational training schools in northwestern Germany. RESULTS: The point prevalence of (mostly slight) irritant skin changes of the hands increased from 35.4% in the initial examination to 47.5% in the intermediate examination and to 55.1% in the final examination. Given a more conservative definition of a case of "hand dermatitis," these estimates were 12.9%, 23.5%, and 23.9%, respectively. Altogether, 34.3 and 15.2 cases of "skin changes (any degree)" and "hand dermatitis," respectively, in 100 person-years were observed during the study period. The incidence rate, i.e., the number of newly diseased study participants in relation to the person-time at risk contributed, decreased in the course of the study. The proportion of dropouts until final follow-up was 51.8%. CONCLUSION: The present results appear to lie in a range with those found in other, much smaller cohort studies. However, comparison of the results is hampered either by the lack of a clear definition or by a different definition of "person-time at risk" or "a case of hand dermatitis." As compared with an external control group of office apprentices, the incidence was several times higher in hairdressing apprentices, which points to the high risk for skin damage in this occupation.

Beauty Culture↗

An empirical investigation on matching in published case-control studies.

The methodological discussion about matching when recruiting controls in case-control studies has been controversial for a long time. To delineate the impact of this discussion on the practice of matching we reviewed 266 case-control studies published in nine yearly volumes of three major epidemiological journals within the period 1955-1994. Among studies published until 1980 71.7% of the control groups were recruited by individual matching compared to 46.4% in 1994. This decline is paralleled by an increase in the application of frequency matching (from 5.0% to 26.2%). As the issue of matching is closely connected with methodological questions of the statistical analysis we also examined the type of analysis applied to the data. We found that the use of logistic regression modeling has dramatically increased during this period (from 18.4% up to 87.2%), whereas application of the traditional Mantel-Haenszel technique for estimating summary odds ratios has nearly vanished. The correct approach for individually matched data in the logistic modeling framework, the conditional likelihood technique, has been unknown in the early part of the time window of our investigation, but is even nowadays applied by only three quarters of the corresponding studies. Our literature-based investigation provides thus compelling evidence that the type of control selection and statistical analysis used in case-control studies have changed substantially during recent years.

Case-Control Studies↗

Hand eczema in a prospectively-followed cohort of office-workers.

A cohort of initially 111 office apprentices was prospectively followed for the duration of their training (2 and 3 years, respectively). The point prevalence of (slight) irritant or atopic hand eczema was 18.9% in the initial and 25.0% in the final examinations. Altogether, 37 cases of (slight) hand eczema were noted within the study period; of these, 10 qualified for a more conservative definition of "hand eczema". Expressed in a person-time-model, the incidence rates were 18.4 and 4.1 cases per 100 persons per year, respectively. The only significant risk factor for the development of (slight) irritant or atopic hand eczema within the study period was previous hand eczema--partly as a child, partly during a preceding occupation (e.g. hairdressing). Compared to one retrospective study in a cohort of older office employees and to a study sampling the general population, incidence rates were slightly higher in this study. Such differences may partly be due to different definitions of what has to be considered "a case of hand eczema". The necessity to (i) communicate on the method of case definition and (ii) develop guidelines for case definition in epidemiological studies is emphasised.

Adolescent↗

[Prevention of melanoma by sun protective measures in childhood. Temporal changes in awareness of parents].

Numerous epidemiological studies on risk factors of malignant melanoma confirm the etiologic role of excessive UV-exposure especially in childhood. Preventive educational campaigns directed to parents of pre-school children have been inaugurated in several countries. In Germany the information was distributed by the "Working group for Preventive Measures in Dermatology" in cooperation with different public health institutions and the media starting in 1993. To evaluate the influence of these efforts on the knowledge and behaviour of the parents, two successive cross-sectional studies at all 56 nursery schools using the same standardised questionnaire were performed. The first interview took place in spring 1993 (before the campaign) with 1341 evaluable questionnaires', the second in fall 1994 (after the campaign) with 1150 evaluable questionnaire. The knowledge of the parents on melanoma risk factors was significantly improved in the second interview. Also the parental behavior regarding sun-protective measures when their children were outdoor at the beach or in the garden definitely changed. In 1993 the best textile sun protection was used by 21% of the parents at the beach and 36% in the garden. These numbers rose to 34% (beach) and 57% (garden) by the second interview. The percentage of children with no sunburn recorded during the preceding summer rose from 39% to 51%. According to the child's gender the parental behavior was different between the sexes; boys were always better protected than girls. The design of this study with two cross-sectional surveys in the same populations does not provide a methodologically sound basis for attributing the observed positive changes to the campaign. Without any doubt it can be stated that the parental knowledge and their attention to sun protection in their children showed substantial improvement in the second survey after the campaign. Thus, these results provide some evidence for the success of the preventive activities and confirm the necessity to continue with such activities.

Child, Preschool↗

Public awareness of malignant melanoma risk factors in Germany.

STUDY OBJECTIVE: To evaluate the effects of a German public education campaign which aimed to improve knowledge on risk factors for malignant melanoma. DESIGN: Comparison of data from two successive cross sectional surveys conducted before (spring 1993) and after (autumn 1994) the campaign. SETTING: All 56 nursery schools in Göttingen, the capital of southern Lower Saxony, Germany. PARTICIPANTS: Parents of children attending the nursery schools. Altogether 1341 questionnaires from parents were included in the first survey (response rate 64.9%) and 1150 questionnaires in the second survey (response rate 61.4%). MAIN RESULTS: The respondents in the second survey were much better at distinguishing true melanoma risk factors from false ones. The distribution of scores measuring the degree of accurate knowledge about melanoma risks indicated that this had improved significantly (p < 0.001). The most pronounced change with regard to knowledge of single risk factors could be observed for "sunburn during childhood," which was correctly identified by 63.1% in the first survey and by 85.6% in the second. Substantial improvement in accurate knowledge about the influence of constitutional skin factors--number of naevi, skin type etc--was also found. CONCLUSIONS: Notwithstanding the methodological problems in this analysis (non-randomised design, only before and after comparison, no control group, number of non-respondents), it is concluded that this campaign improved understanding of the risks of melanoma. Continuing public education activities should be implemented to sustain and improve further knowledge on prevention of malignant melanoma.

Adult↗

Systematic review of case-control studies: oral contraceptives show no effect on melanoma risk.

BACKGROUND: Parallel to the rising incidence of malignant melanoma in fair-skinned populations, intensive efforts are currently devoted to identifying risk factors for melanoma in addition to the well-known cutaneous factors and those variables related to UV-exposure. OBJECTIVE: Systematic review of published results to elucidate the role of oral contraceptives in the development of malignant melanoma. DATA SOURCES: Literature retrieval systems MEDLINE and CANCERLIT as well as reference lists of already collected studies. STUDY SELECTION: All 18 (non-duplicate) case-control studies on the above relationship. DATA EXTRACTION: From the published data, study-specific odds ratios (OR) and accompanying confidence intervals (CI) were recalculated. For a quantitative meta-analytical summarisation two different models have been applied: a "fixed effects" (FE) and a "random effects" (RE) model. DATA SYNTHESIS: Study-specific ORs ranged from 0.13 up to 1.85; however, the majority of studies (14 of 18) yielded similar ORs within the interval [0.82, 1.15]. The summary ORs estimated from FE- and RE-models were both 0.95 (95% CI: [0.87, 1.04] for the FE-model, [0.87, 1.05] for the RE-model). CONCLUSION: The systematic review of case-control studies revealed no evidence for an aetiological role of oral contraceptives in the development of malignant melanoma.

Case-Control Studies↗

[Incidence of ultrasound detectable liver hematomas after ultrasound controlled fine needle puncture with the 0.95 mm cutting biopsy cannula in comparison with percutaneous liver biopsy with the 1.4 mm Menghini needle].

BACKGROUND: Recently, a high incidence of ultrasound-detected hepatic hematomas due to percutaneous liver biopsy has been reported. Until yet, little is known about the incidence of asymptomatic hepatic hematomas following sonographically guided fine-needle biopsy. PATIENTS AND METHODS: For that reason, we carried out a prospective study with sonographic examinations before and after liver biopsy in 160 patients. 51 patients, aged 50 to 83, median 67 years, with focal liver lesions had ultrasound-guided liver biopsy using the 0.95 mm-cut biopsy-needle, in 109 patients (17 to 80, median 49 years) with diffuse liver disease percutaneous liver biopsy with the 1.4 mm-needle of Menghini was performed. RESULT: After fine-needle biopsy none of the 51 patients with focal liver lesions displayed liver hematoma on ultrasonography. In the group of patients who underwent percutaneous Menghini biopsy a liver hematoma, sized up to 12 x 5 cm in diameter, occurred four times (3.7%). CONCLUSION: The results of this study indicate that fine-needle biopsy of the liver is a particularly safe diagnostic procedure, when compared with percutaneous Menghini biopsy.

Adolescent↗