Biomedical subjects

M Graw

Publications and source records attributed to M Graw.

At least 19 recordsLinked to original sources

PubMed2003

Concentration dependency of the BAC/BrAC (blood alcohol concentration/breath alcohol concentration) conversion factor during the linear elimination phase.

According to the theoretical pharmacokinetical considerations put forward by Wehner et al. the BAC(ven)/BrAC conversion factor Q is not a constant value and varies depending on the pharmacokinetic phase deduced from the alcohol concentration curve. Based on these considerations we propose that Q must be inversely proportional to the BrAC during the postabsorptive linear elimination phase, expressed as the hyperbola Q=1/kappa+(CT)/BrAC. The constants kappa or 1/kappa and (CT)--where (CT) consists of different parameters which remain constant during the linear elimination phase--can be experimentally determined from the linear relationship BrAC = kappaBAC(ven)-kappa(CT). To test this hypothesis 12 human volunteers received parenteral doses of ethanol. During the elimination phase, BAC and BrAC of each volunteer were measured between 18 and 34 times in a BrAC range between 0.65 mg/l and 0.12 mg/l. The conversion factor Q was either expressed in the form of the hyperbola Q=1/kappa+(CT)/BrAC or directly calculated from the ratio BAC(ven)/BrAC and the results obtained using both methods were found to be very similar. The values of 1/kappa of the hyperbolic functions varied between 1.808 and 2.165 and those of (CT) between 0.004 and 0.127. For a BrAC of 0.25 mg/l, an average value of 2.308+/-0.080 could be calculated for the conversion factor Q(0.25). On average, the value of Q(0.40) amounted to 2.207+/-0.048 and that of Q(0.55) to 2.160+/-0.056.

Adult↗

PubMed2002

Fatal pedestrian-bicycle collisions.

Although, fatal collisions between pedestrians and bicycles are relatively rare, they are still of forensic relevance because of the need to explore the circumstances of the accident. Based on three reconstructed cases, situation and injury patterns are presented that might prove useful in future cases: usually the person causing the accident is the cyclist while the pedestrian generally suffers more severe injuries; the situation at the site of accident is important for its reconstruction: end location of the persons involved in the accident, injuries and traces on pedestrians and cyclists, traces at the site of accident and on the bicycle; because of the lack of pre-crash traces and any eyewitness accounts, the pedestrian's injuries are the best starting point for the reconstruction of the accident; a characteristic wound on the lower leg of the pedestrian that reveals the initial impact between the front wheel and the leg is crucial not because of its seriousness, but because of its external morphology; the injuries that can be expected by the following impact between body and handlebar are unspecific and only minor; the most severe injuries to the pedestrian as a result of the accident are caused secondarily by falling and hitting the head on the road; the fall of the cyclist, however, corresponds to a throw-off followed by a sliding phase with less impact load when the head hits the ground [maximum abbreviated injury scale 1 (MAIS 1)]; the cyclists involved are mainly younger persons on fashionable bicycles (here: mountain bikes); in the great majority of cases, the injured pedestrians are frail, elderly people with a lower tolerance of trauma.

Accidents, Traffic↗

PubMed2002

Investigations on the reliability of determining an individual's age from the proximal femur.

In the context of individual identifications the reliable determination of age is important. It has been suggested that the femur is appropriate for reliably determining age and excellent results were indeed claimed but calculated errors of estimation were often missing in the studies. In order to check the reliability and validity for forensic diagnostics, two independent investigators who were not informed of the actual age of the femur specimens evaluated x-ray views of 90 femurs according to methods described in the literature. The results of the two investigators differed by maximally 5 years in 64.4% of all cases examined; the average error of estimation amounted to 10.1-17.0 years. Only one-seventh of all cases examined could be precisely grouped into the 5-year class. Deviations of more than 15 years occurred in nearly one fourth of all cases. In particular, individuals over 50 years of age were estimated as being much younger. We must therefore conclude that the method under examination is only appropriate for rough estimations of age. A more accurate estimation within a five-year interval is only rarely possible.

Adolescent↗

PubMed2001

Sex determination and estimation of stature from the long bones of the arm.

The determination of sex and the estimation of stature from bones play an important role in identifying unknown bodies, parts of bodies or skeletal remains. In medico-legal practice statements on the probable sex of a decomposed body or part of a body are often expected even during autopsy. The present study was, therefore, restricted to few easily accessible dimensions from bones which were prepared only by mechanically removing soft tissues, tendons and ligaments. The specimens came from the Anatomical Institutes in Munich and Cologne from the years 1994-1998 including a total of 143 individuals (64 males and 79 females). The mean age was 79 years (46-108), the mean body height 161cm (134-189). The following measurements were taken: maximum humeral length (mean: 33.4cm in males; 30.7cm in females), vertical humeral head diameter (mean: 5.0cm in males, 4.4cm in females), humeral epicondylar width (mean: 6.6cm in males; 5.8cm in females), maximum ulnar length (mean: 26.5cm in males, 23.8cm in females), proximal ulnar width (mean: 3.4cm in males, 2.9cm in females), distal ulnar width (mean: 2.2cm in males; 1.8cm in females), maximum radial length (mean: 24.6cm in males; 22.0cm in females), radial head diameter (mean: 2.6cm in males, 2.2cm in females) and distal radial width (mean: 3.6cm in males; 3.2cm in females). The differences between the means in males and females were significant (P<0.0005). A discriminant analysis was carried out with good results. A percentage of 94.93% of cases were correctly classified when all measures of the radius were applied jointly, followed by humerus (93.15%) and ulna (90.58%). Applied singly, the humeral head diameter allowed the best distinction (90.41% correctly grouped cases), followed by the radial length (89.13%), the radial head diameter (88.57%) and the humeral epicondylar width (88.49%). The linear regression analysis for quantifying the correlation between the bone lengths and the stature led to unsatifactory results with large 95%-confidence intervals for the coefficients and high standard errors of estimate.

Adult↗

PubMed2001

Metric sex differentiation of the pars petrosa ossis temporalis.

The importance of the petrous portion for metric sex determination is a controversial subject in the archaeological and anthropological literature. To achieve a forensically suitable method for sex differentiation, 10 measuring distances were determined on recent forensic material in the form of 410 petrous portions, which had proved to be reliable in the preliminary examinations. The most important findings can be summarized as follows: the petrous portion revealed significant metric sex differences, in particular the width:height index (P < 0.001); the sex differences are age-dependent; differences in the measuring distances on the petrous portion can be observed with regard to their lateral location on either side of the skull; the discrimination analysis allows a correct classification of two-thirds of all petrous portions studied. To some extent, these findings contrast with those already published, but the discrepancies can be attributed primarily to the different composition of the samples used in the respective studies.

Adult↗

PubMed2000

Y chromosomal short tandem repeat (STR) loci in a representative group of males living in South Württemberg: a database for application in forensic medicine.

In this study, we resolved the allelic distribution of three Y chromosomal short tandem repeats (STRs), DYS19 (n=218), DYS390 (n=257) and DYS393 (n=215), in a population study of 257 unrelated men living in the area of South Wüerttemberg/Hohenzollern. In DYS19 and in DYS393, five different alleles were discovered, and in DYS390, six different alleles. Forty-nine different haplotypes were found in 202 unrelated male individuals. By investigating each of the three STR systems separately, the most powerful results were found in DYS390, with a PE (power of exclusion) of 0.74, followed by DYS19 (PE: 0.65) and DYS393 (PE: 0.47). Using a combination of two systems (n=202), the PEs ranged from 0.79 (DYS19 and DYS393) to 0.89 (DYS19 and DYS390). The combination of all three STR systems revealed a PE of 0.93.

DNA Fingerprinting↗

PubMed2000

DNA typing of human remains found in damp environments.

DNA typing is often used to determine identity from human remains. The environment to which the material has been exposed, however, is crucial for the success of the investigation. Damp conditions in particular can cause a rapid degradation of DNA, even in bone and teeth, and thus reduce the chances of successful typing. Here, we present the results of investigations performed on four skulls that had been lying in a damp environment for periods ranging from almost 1 year to about 45 years. In none of these cases was DNA typing successful on bone or, where present, on teeth. Where remnants of brain tissue were used, however, complete STR typing was possible in one case, partial STR typing in another, and mtDNA sequencing could be carried out in three cases. These findings suggest that brain tissue is relatively resistant to putrefaction in damp environments and, unlike bone, appears to exhibit a certain degree of protection against DNA degradation.

Aged↗

PubMed2000

Determination of sex from femora.

The determination of sex from bones or bone fragments considerably contributes to identifying unknown bodies or skeletal remains. Due to temporal change and regional differences anthropometric standards have to be constantly renewed. The present study provides measurements of femoral dimensions in a contemporary German population and analyses sexual dimorphism by discriminant analysis. Maximum length (male: 46.4+/-2.4 cm, female: 43.4+/-2.4 cm), maximum midshaft diameter (male: 3.1+/-0.2 cm, female: 2.8+/-0.2 cm), condylar width (male: 8.4+/-1.0 cm, female: 7.7+/-0.5 cm), vertical head diameter (male: 4.9+/-0.3 cm, female: 4.4+/-0.3 cm), head circumference (male: 15.7+/-0.8 cm, female: 13.8+/-1.0 cm) and transverse head diameter (male: 4.9+/-0.3 cm, female: 4.3+/-0.3 cm) were measured in 170 femora, 100 from male (age: 16-92 years, mean: 60.8 years; body height: 153-190 cm, mean: 171 cm) and 70 from female (age: 20-96 years, mean: 72 years; body height: 146-175 cm, mean: 161 cm) individuals. In the discriminant analysis (leave-one-out-method) 67.7% of cases could be grouped correctly with the maximum length alone, 72.4% with the maximum midshaft diameter, 81.4% with the condylar width, 86.8% with the vertical head diameter, 87.7% with the head circumference and 89.6% with the transverse head diameter. The stepwise procedure with all head measurements showed that the results for the transverse head diameter could not be improved. With all measurements subjected to stepwise procedure 91.7% of cases could be classified correctly combining midshaft diameter and head circumference (D=3.012xmidshaft diameter in cm+0.780xhead circumference in cm 20.569).

Adolescent↗

PubMed2000

Invasion and distribution of methanol.

After the enzyme systems responsible for methanol oxidation were blocked by ethanol, five test persons were given methanol at a dose of approximately 10 mg/kg weight, once orally and once parenterally. Taking into account the endogenous blood methanol levels detectable before the administration of methanol, C0 concentrations of 11.1-15.9 mg/kg were reached. This corresponds to a distribution volume of approximately 0.77 +/- 0.07 l/kg, which is comparable to the 0.78 +/- 0.09 l/kg obtained for ethanol. After parenterally administering methanol as a bolus, the distribution half-life was on average 8 min (range: 3.8-13.8 min). After oral administration of methanol diluted in 100 ml water on an empty stomach, invasion took place with a half-life of approximately 5 min (3.8-6.9 min). In one case, however, due to vegetative disturbances the invasion half-life was 23.1 min.

Administration, Oral↗

PubMed1999

The form of the supraorbital margin as a criterion in identification of sex from the skull: investigations based on modern human skulls.

Sexual dimorphism in the shape of the supraorbital margin was reported by Broca and various subsequent authors, but no consistently applied, precise definition has been established. In this study of modern human skulls, the value of our definition of the sex-related difference in this area in the identification of sex from the skull was investigated. It was found that this feature can be assessed reliably, is strongly related to sex, and is independent of the side. The accuracy of identification of sex using this method alone was found to be about 70%.

Female↗

PubMed1998

Curvilinear increase in methanol concentration after inhibition of oxidation by ethanol: significance for the investigation of endogenous methanol concentration and formation.

Endogenous methanol production was assessed over a period of 5 h in subjects given an infusion of ethanol to inhibit methanol oxidation in the liver after a period of fasting and abstinence from alcohol. Ethanol was administered to each of five subjects at rates of 0.35 g/kg per hour and 0.70 g/kg per hour. The rise in methanol concentration was biphasic regardless of the rate of ethanol administration, with a steeper gradient in the first 10-30 min. This may be due to the existence of a deep compartment from which methanol can be displaced by ethanol. This could take the form of loose binding of methanol to the hepatic oxidation enzymes as an enzyme-substrate complex, or a shift of the oxidation-reduction equilibrium between methanol and formaldehyde. The biphasic nature of the increase, with an initial steeper rise, means that the values obtained in the first 30 min should be excluded from the calculations when the rate of endogenous methanol production is determined by linear regression analysis. Endogenous methanol concentrations to be taken into account after ethanol administration are on average 0.4-0.6 mg/kg higher than those detectable in the absence of ethanol due to the additional method displaced from the deep compartment.

Adult↗

PubMed1997

The kinetics of methanol elimination in alcoholics and the influence of ethanol.

Methanol concentrations were studied during the end phase of ethanol elimination and for about five hours afterwards in 12 alcoholics admitted with alcohol intoxication for acute care. The rate of ethanol elimination (beta 60) ranged from 0.114 g/kg/h to 0.270 g/kg/h (mean 0.178 +/- 0.045 g/kg/h). The methanol concentration was found to remain almost steady as long as ethanol levels were relatively high, and changed only to an extent that could be explained by the combined opposing influences of methanol excretion and endogenous synthesis. There was no significant relationship between the rate of ethanol elimination and the methanol level. The methanol concentration began to decrease when the ethanol concentration had fallen to under 0.2 g/kg. When the ethanol concentration had fallen to base levels, methanol was eliminated at a rate characterized by an elimination constant (kel) of 0.212-0.481 h-1, and a half life of 1.44-3.27 h. There was a positive correlation between the rate of ethanol elimination and the rate of methanol elimination (r = 0.642; p < 0.05).

Adult↗

PubMed1997

Methanol elimination in non-alcoholics: inter- and intraindividual variation.

Five male subjects aged between 25 and 40 years were given methanol at a dose of 10 mg/kg, once orally and once intravenously, while the enzyme systems responsible for methanol oxidation were blocked by ethanol. The study assessed the duration of inhibition of methanol oxidation in relation to the blood ethanol concentration, and the elimination of methanol not influenced by ethanol. Methanol elimination was found to begin at a blood ethanol concentration of 0.04-0.13 g/kg. Elimination constants of 0.406-0.267 h-1 with corresponding half-lives of 1.71-2.60 h were established for methanol not influenced by ethanol. When data from a previous study using an identical protocol for parenteral administration were included, making the total number of subjects nine, the mean elimination constant was found to be 0.298 +/- 0.470 h-1 and the mean half-life 2.37 +/- 0.357 h, distribution being normal. No evidence of any differences in methanol elimination kinetics between alcoholics and non-alcoholics or of a significant influence of the route of administration was found. The extent of intraindividual variation in methanol elimination as indicated by the difference in each subject between the values established, expressed as a percentage of the corresponding mean values, was found to be 3-25%, which is comparable to the magnitude of intraindividual variation in the rate of ethanol elimination.

Administration, Oral↗

PubMed1996

Endogenous methanol: variability in concentration and rate of production. Evidence of a deep compartment?

The endogenous methanol concentration was determined in 72 men aged between 18 and 35 years in the morning after a 12-h period of fasting and abstinence from alcohol. The distribution curve was found to be skewed to the right, the concentrations ranging from '0' (below the detection threshold) to 3.4 mg/kg. The median was 0.1 mg/kg and the mean 0.35 mg/kg. Significant differences were found between three groups defined according to the duration of prior abstinence from alcohol (8 h, 30 h, and 5 days). The highest values were seen after the shortest period of abstinence and the lowest values after the longest period of abstinence. The course followed by the methanol concentration in the presence of blocking of methanol oxidation by orally or parenterally administered ethanol was observed over at least 10 h on two separate occasions in a further 8 subjects aged between 24 and 35 years. At blood ethanol concentrations of more than 0.20 g/kg, the rate of production of methanol, calculated by regression, ranged from 0.09-0.37 mg/kg/h (r = 0.970-0.554, S(y.x) = 0.227-0.565 mg/kg). The rise in methanol concentration at the start of ethanol administration was significantly more rapid than the subsequent rise. It is hypothesised that there may be a so-called deep compartment for methanol that would explain the dependence of the endogenous methanol level on the duration of the preceding period of abstinence from ethanol, and the occurrence of an initial phase of faster rise in methanol concentration associated with the administration of ethanol.

Adolescent↗

PubMed1996

[Changes in the spectrum of alcohol-induced traffic accidents in relation to blood alcohol level].

A retrospective study was undertaken to determine whether the degree of alcohol intoxication has an effect on the driving performance with regards to both the quantity and quality. A total of 625 accidents caused by drivers who were under the influence of alcohol were reviewed. They were divided into three groups according to the blood alcohol concentration (BAC):0.30 - 1.09 g/kg, 1.10 - 1.99 g/kg and > 2.00 g/kg. In order to exclude the influence of factors unrelated to alcohol, the groups were matched for age, sex, location of accident and the light and road conditions. This resulted in a total of 85 accidents in each group. The accidents were classified with reference to the "Register of causes of accidents" used in road accident statistics. The three groups differed significantly in their causes of accidents (p < 0.025), although those due to speeding dominated in each group. In the group with low BAC, the next most common accidents were the ones caused by failure to give way. In the group with medium BAC, rear-end collisions and accidents occurring during low speed manoeuvres were the second most common. In the group with highest BAC, the next most common causes of accidents were the leaving of the correct traffic lane unassociated with speeding.

Accidents, Traffic↗

PubMed1994

Spleen findings in drowning.

A retrospective study of spleen findings in 42 victims of drowning and a comparison group of 42 cases of asphyxiation due to other causes (hanging, ligature strangulation and manual strangulation), that were matched for sex, age, body weight and build, was performed. Significantly smaller spleen weights (P < 0.05), spleen weight:body weight ratios (P < 0.01) and spleen weight:liver weight ratios (P < 0.01) were found in the victims of drowning. The difference in weight was approximately 18%. A significant negative correlation between spleen weight and blood alcohol concentration was found in the study group (r = -0.44; P < 0.01), but not in the control group. The possibility that the findings are due to a stress reaction caused by hypoxia in the presence of cooling and an influence of alcohol on reflex mechanisms is discussed.

Adolescent↗

PubMed1993

[Fatal complications of a colon contrast enema due to erroneous insertion of the infusion catheter in the vagina].

A 68-year-old woman was to have a barium enema of the colon to discover the cause of recurrent cramp-like symptoms in the lower abdomen. At the beginning of the examination the responsible radiologist saw, during a fluoroscopic check, that the contrast medium had not advanced beyond the region of the infusion catheter tip. Believing this to be due to blockage in the catheter he increased the infusion pressure. Suddenly the patient went into treatment-resistant shock and died. The autopsy revealed that the infusion catheter had by mistake been placed into the vagina. This had caused a tear in the vagina with resulting subperitoneal contrast-medium infiltration. Embolization of contrast medium to the lung was demonstrated both histologically and radiologically. The cause of death was the combined effect of the embolism and peritoneally induced vagal shock.

Aged↗

PubMed1993

[Rate of ethanol clearance after oral and parenteral ethanol administration].

A crossover investigation of the ethanol concentration decline after oral and parenteral administration of ethanol respectively was performed with direct intra- and interindividual comparison. No significant differences in relation to the kind of administration were noted. An influence of the circadian rhythm on the rate of decline could be excluded. The low beta 60 values derived (average: 0.111 g/kg/h) can be explained by the long period over which the probands were denied food.

Adult↗