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G Berghaus

Publications and source records attributed to G Berghaus.

At least 19 recordsLinked to original sources
PubMed2006

Demands on scientific studies in different fields of forensic medicine and forensic sciences. Traffic medicine--impaired driver: alcohol, drugs, diseases.

Since human performance is a key factor in crash causation detailed knowledge of the involvement of alcohol, drugs and diseases is of fundamental interest for road safety. To better understand the effect of these influencing factors it is important to use a combination of witness observations and a range of experimental and epidemiological studies. Epidemiological approaches to research such as road-side-surveys, case-control-studies, culpability analysis, pharmaco-epidemiological studies are usually seen as being able to provide the best answers. This article discusses the relative merits of experimental and epidemiological approaches.

Accidents, Traffic↗
PubMed2006

Meta-analyses in research in forensic medicine: Alcohol, drugs, diseases and traffic safety.

The meta-analytic approach is one of the most informative methods to structure and combine findings of different studies. Hence, even in forensic sciences meta-analyses were used to arrange knowledge. At most this technique was applied to summarize results of experimental and epidemiological studies on alcohol, illegal drugs, medicines, diseases and driving or skills related to driving. The article demonstrates the method used and the results obtained.

Accidents, Traffic↗
PubMed2004

Dose related risk of motor vehicle crashes after cannabis use.

The role of Delta(9)-tetrahydrocannabinol (THC) in driver impairment and motor vehicle crashes has traditionally been established in experimental and epidemiological studies. Experimental studies have repeatedly shown that THC impairs cognition, psychomotor function and actual driving performance in a dose related manner. The degree of performance impairment observed in experimental studies after doses up to 300 microg/kg THC were equivalent to the impairing effect of an alcohol dose producing a blood alcohol concentration (BAC) >/=0.05 g/dl, the legal limit for driving under the influence in most European countries. Higher doses of THC, i.e. >300 microg/kg THC have not been systematically studied but can be predicted to produce even larger impairment. Detrimental effects of THC were more prominent in certain driving tasks than others. Highly automated behaviors, such as road tracking control, were more affected by THC as compared to more complex driving tasks requiring conscious control. Epidemiological findings on the role of THC in vehicle crashes have sometimes contrasted findings from experimental research. Case-control studies generally confirmed experimental data, but culpability surveys showed little evidence that crashed drivers who only used cannabis are more likely to cause accidents than drug free drivers. However, most culpability surveys have established cannabis use among crashed drivers by determining the presence of an inactive metabolite of THC in blood or urine that can be detected for days after smoking and can only be taken as evidence for past use of cannabis. Surveys that established recent use of cannabis by directly measuring THC in blood showed that THC positives, particularly at higher doses, are about three to seven times more likely to be responsible for their crash as compared to drivers that had not used drugs or alcohol. Together these epidemiological data suggests that recent use of cannabis may increase crash risk, whereas past use of cannabis does not. Experimental and epidemiological research provided similar findings concerning the combined use of THC and alcohol in traffic. Combined use of THC and alcohol produced severe impairment of cognitive, psychomotor, and actual driving performance in experimental studies and sharply increased the crash risk in epidemiological analyses.

Accidents, Traffic↗
PubMed2001

Sildenafil (Viagra): is there an influence on psychological performance?

BACKGROUND: Sildenafil (Viagra) is a well-introduced medicine for erectile dysfunction; many studies about effects and side effects are published. Beside these aspects of treatment the influence of sildenafil on psychophysical performance is of interest. cGMP is one of the most important second messengers in the central nervous system (CNS), so even very small changes of the intracellular cGMP-level caused by phosphodiesterases inhibition may be relevant for CNS-function. We wanted to verify the hypothesis whether sildenfail influences human psychomotor performance, especially under the aspect of traffic safety, or not. METHODS: Designed as a pilot study we tested 6 male healthy volunteers using a test battery of 7 different psychophysical performances tests. Each individual did the test battery twice, once without drug and once after a single oral dose of 100-mg sildenafil. 3 persons did the first and 3 others did the second experiment under the influence of drug (UID). All results (37 parameters) were analysed by t-test for paired samples using a confidence interval of 95%. RESULTS: Only two parameters of 2 different tests showed significant differences. In the simple choice reaction test (DR2) the mean reaction time got better in the group with sildenafil; in the multiple choice reaction test with stress induction (RST3) the amount of wrong answers indicated a weak influence of performance without statistical significance, six parameters (dominantly in the speed anticipation test (DEST)) represented an increase and one other (RST3 second part) showed a decrease UID. The uppermost parameters (76% of all items) stayed on equal levels for both groups. CONCLUSION: Sildenafil showed no important impairment of psychophysical performance, no strong improvement was found as well. With a look at the therapeutically indication of sildenafil the improvement in sexual activity may indicate no incapacity in traffic and other psychomotoric/psychophysical functions.

Adult↗
PubMed1993

[Empirical studies of automobile driving fitness of patients treated with methadone-substitution].

The aim of this experimental study was to gain an impression on the driver fitness of heroin addicts which were at the moment substituted by methadone especially within a methadone program sponsored by the government of NRW. 21 out of 34 patients investigated were unfit to drive because they were at the time the tests were conducted under the effect of at least one additional psychotropic substance other than methadone or because at prior blood tests within 3 months they had been found at least twice under the effect of psychotropic drugs or they were known as concomitant drug users. The remaining 13 methadone patients were matched with 13 control subjects of the same sex, education and-within a range of +/- 2 years-also the same age. Testing short term memory, tracking, decision and reaction behavior, perception, sustained attention, speed estimation, peripheral attention with simultaneous central task, reactive loading, personality questionnaires including traffic specific questions and psychopathologic characteristics the patients yielded significant poorer results compared with the control group. When selecting 6 very good patients according to the decision of the physicians the significant differences concerning performance measures vanished but some differences concerning personality traits still remained. The results confirm the expert's opinion-called "disease and motor traffic"-that in general methadone substituted patients are unfit to drive. The driver fitness of the very few optimal patients depends on the amount of the personality disorders.

Adult↗
PubMed1990

The effect of various stain carriers on the quality and quantity of DNA extracted from dried bloodstains.

Bloodstains were made with 200 microliters blood on each of 11 different common substrates to examine the effect of the stain carrier on the amount and quality of DNA recoverable. High-molecular-weight DNA was extracted from all samples after 2 days. The yield of DNA from each sample varied considerably, not only between the different stain carriers but also within a given category. With a DNA yield of up to 10 micrograms, paper, glass, nylon, wood, smooth leather and wool gave the best results, followed by blue denim and wallpaper (up to 6 micrograms), cotton fabric and carpeting (up to 4 micrograms) and suede (up to 2 micrograms). For several stain carriers the DNA-containing solution was contaminated by chemical substances, which in the case of the blue denim, suede, and carpet samples inhibited the digestion of the DNA with restriction enzymes and prevented DNA typing. The different textures of the stain carriers tested and (as for varying yields on the same carrier) the differing degree of loss of DNA during extraction and the physiological variation in the number of leukocytes in human blood are discussed as possible reasons for the wide range of variation in the amounts of DNA it was possible to extract.

Blood Stains↗
PubMed1990

[Possibilities for individual identification of hair roots using DNA probes].

High-molecular weight DNA was extracted from hair roots. The obtained DNA was digested with Hae III and Msp I and transferred to nylon membranes by Southern blotting. The possibility of applying a probe for sex determination (pHY2.1) a "single-locus"-probe (YNH24) as well as a "multi-locus"-probe (M13) was examinated as a function of the amount of hair being supplied. In the laboratory experiment a single hair root was enough for a sex determination or individual identification. Because of methodical difficulties in practice this kind of profiling should only be done with several hair roots.

Adolescent↗
PubMed1989

DNA extraction from bloodstains in respect to age and stained substrate.

The amount and the quality of DNA that could be extracted from bloodstains equivalent to 200 microliters blood were examined after 3, 6, 9, 12, 15, 18 and 21 days of storage under dry or humid conditions at room temperature. DNA was also extracted from two days old 200 microliters bloodstains on different stain carriers. The amount of DNA that could be extracted showed a dependency on all the parameters that were examined. On carriers with a rough surface structure, where the blood can soak in, the resolving of leukocytes was impaired and the DNA recovery rate was low, e.g. carpeting and suede. The DNA yield was higher for substrates with a smooth surface, e.g. paper, glass and smooth leather. The aging experiments revealed that for the stains stored under dry conditions, there was no decrease in the DNA yield for stains on glass, while the amount of DNA that could be extracted became less for older stains on cotton. Under humid conditions the DNA yield was high and did not decrease for both glass and cotton fabric. The quality of the DNA was not impaired by aging or storage conditions, but for several stain carriers the DNA was contaminated by chemical substances which inhibited restriction enzyme digestion and successful DNA-typing.

Aging↗
PubMed1989

[Methodologic variants of DNA blood stain analysis: extraction in agarose and digoxigenin marking].

DNA was extracted from 1 microliter bloodstains on glass, cotton cloth and paper using proteinase K digestion in a solution containing low gelling temperature agarose. This method is advantageous for small amounts of source material because the purifying procedures of other methods that contain a risk of loss of DNA, are avoided. The recovered DNA was digested with Hae III and after Southern blotting, a Digoxigenin labeled probe (Amprobe, human Y-chromosome specific repeat) was successfully used for sex determination. With this non-radioactive method quantities of DNA smaller than 1.5 pg were detected.

Blood Grouping and Crossmatching↗
PubMed1986

Brain macrophages in human cortical contusions as indicator of survival period.

The aim of this study was to establish a morphologic time scheme with which cases of cerebral contusion with unknown survival periods can be dated. Our study of 275 cases was limited to qualitative and quantitative changes in macrophages. The appearance of macrophages and their distribution as well as their content of neutral fat, esterified cholesterol, erythrocytes, siderin, hematoidin, and ceroid were correlated with the survival period. For each cytologic criterium, the observation period, distribution-free limits of tolerance, and relative frequency of identification in different survival periods were determined, and the limits of confidence calculated. The findings permit the dating of trauma in cases with unknown survival periods. Moreover, the probability of this dating was calculated.

Adolescent↗