Blood versus bone marrow isopropanol concentrations in rabbits

The use of bone marrow to determine the blood isopropanol concentrations becomes important when a blood specimen is contaminated or unavailable. The blood/marrow isopropanol ratios were determined in rabbits autopsied 0, 4, and 24 h after sacrifice. The lipid content of the individual marrow specimens was shown to have a significant influence on the range of ratios. When the determined marrow isopropanol concentrations were corrected for lipid content, a better correlation between blood and marrow concentrations was obtained. The ratio (1.45 ± 0.17) was not altered significantly by postmortem time or temperature.Although acetone was not exogenously administered to the rabbits, but rather was endogenously produced from isopropanol metabolism, the relationship between blood and marrow acetone concentrations was somewhat linear. However, the range of observed and corrected blood/marrow acetone ratios was altered significantly by storage temperature, and delays between death and analysis. Thus, under the experimental conditions of this study, marrow isopropanol concentrations may be used to predict blood isopropanol concentrations, whereas marrow acetone concentrations can not.     

Blood versus bone marrow pentobarbital concentrations

Postmortem pentobarbital levels in rabbit heart blood and bone marrow were determined and compared. The average ratio of femur marrow/blood pentobarbital concentrations in 24 rabbits was 1.06 +/- 0.05. The average percent difference between actual plasma pentobarbital concentrations and calculated plasma pentobarbital concentrations was 5.82 +/- 1.96. Concentrations were determined by gas chromatography of extracted, derivatized pentobarbital.     

Blood Versus bone marrow ethanol concentrations in rabbits and humans

Post-mortem ethanol levels in bone marrow and heart blood were determined in rabbits and humans. The average ratio of blood/femur marrow ethanol in 39 rabbits was 2.10 ± 0.23 with a range of 1.27 – 3.50. In 18 human autopsy cases the average ratio of blood/rib marrow ethanol levels was 2.16 ± 0.32 with a range of 1.65 – 2.94. The average blood/marrow ratios in humans and rabbits were comparable. However, a wider range of ratios was noticed in the rabbit study.     

Blood, bone marrow and eye fluid ethanol concentrations in putrefied rabbits

The effect of putrefaction on postmortem blood, bone marrow and eye fluid ethanol levels was evaluated in rabbits. Control and dosed animals were sacrificed and stored at either room temperature (approx. 19 degrees C) or cold temperature (approx. 3.5 degrees C) for as long as 28 days. Control animals stored at room temperature showed ethanol levels in the bone marrow that peaked at 7 days after sacrifice, followed by decreases to a nondetectable level at 21 days. Overall decreases were demonstrated in bone marrow of dosed rabbits stored at room temperature for all postmortem intervals. The control animals stored at low temperature showed no ethanol in the bone marrow and blood until 21 days after sacrifice. Dosed rabbits stored at low temperature showed no significant changes in blood and marrow ethanol until 21 days after sacrifice.     

Plasma versus bone marrow flurazepam concentration in rabbits

Methods for the quantitation of flurazepam in plasma and bone marrow were developed for the purpose of determining the relationship between flurazepam concentrations in both tissues.Albino New Zealand rabbits, given flurazepam in doses of 5, 10, or 20 mg/kg, were sacrificed either one or three hours after drug administration. Flurazepam concentrations in plasma and bone marrow were determined utilizing a gas-liquid chromatograph equipped with an electron capture detector. The average plasma/bone marrow flurazepam ratios were 0.033 ± 0.012 and 0.024 ± 0.012 for rabbits sacrificed one hour and three hours after dosing, respectively. This study showed that a range of plasma flurazepam levels can be estimated from known bone marrow concentrations. The overall mean plasma/bone marrow ratio for all rabbits used in this study was 0.029 ± 0.012 with a range of 0.010 to 0.055.     

Plasma versus bone marrow desipramine: a comparative study

Correlation between plasma and bone marrow tricyclic antidepressants has not been studied before. Two groups of rabbits were given 10 and 20 mg of desipramine/kg body weight, respectively. Desipramine was administered to the animals once daily by mouth for 5 days. On the fifth day the animals were sacrificed and blood and bone marrow samples were collected and analyzed using a high performance liquid chromatographic (HPLC) method. Data showed that a correlation exists between bone marrow and blood desipramine. The bone marrow desipramine concentration increased as its blood levels increased. The average ratio of bone marrow to blood desipramine +/- S.D. (standard deviation) in both dosage groups was 37.2 +/- 4.46 with a range of 30.99-44.82. This investigation is promising and shows that bone marrow could be used as an alternative tissue in the absence of a suitable blood sample.     

A comparative study of ethchlorvynol levels in blood versus bone marrow

Bone marrow may be utilized as an alternative biological sample in cases where uncontaminated blood samples are not available for analyses. Bone marrow/blood ratios of ethchlorvynol as a function of time and dosage level were determined in 40 rabbits. A modified quantitative analysis that produced accurate and reproducible results was employed for the determination of ethchlorvynol levels. Further, ten blood and bone marrow samples containing ethchlorvynol were chosen to study the effects of storage for a period of 24 hours. Studies of blood and bone marrow ethchlorvynol levels with time showed no linear relationship. Bone marrow/blood ratios as a function of dose resulted in close mean averages with a wide range of values. Significant losses in both blood and bone marrow ethchlorvynol levels were evidenced in most of the samples subjected to the 24-hour storage study.     

Evaluation of post-mortem ethanol concentrations in pericardial fluid and bone marrow aspirate

This study confirmed post-mortem ethanol concentrations in pericardial fluid and bone marrow aspirate in comparison with those in the blood in medicolegal autopsy cases (n = 140, within 48 h post-mortem). The specimens were examined by head-space gas chromatography/mass spectrometry. Ethanol concentrations in the pericardial fluid (y) were approximately equivalent to those in peripheral blood (x): y = 0.99x + 0.02, n = 44, r = 0.972. A high stomach ethanol concentration (>10 mg/ml) appeared to mildly affect the pericardial levels. There was no significant interference in drowning cases. Ethanol concentrations in bone marrow aspirates (y) also showed a good correlation with those in the peripheral blood (x): y = 0.77 x + 0.02, n = 20, r = 0.981. A dissociation was observed in cases of delayed death from hemorrhagic/traumatic shock and elderly victims. These findings suggest that pericardial fluid and bone marrow aspirate can be used as an alternative material when adequate blood specimens are not available.     

Determination of morphine in postmortem rabbit bone marrow and comparison with blood morphine concentrations

The aim of this study is to predict how long after time of death a buried body could be analyzed for opiates in soft tissues and to show the accessibility and suitability of bone marrow as a useful toxicological specimen from buried bodies. Morphine solutions were injected in nine albino rabbits. Doses ranged from 0.3 to 1.1 mg/kg with 0.1 mg/kg increments. One hour after the injections, the rabbits were sacrificed. Blood, urine and bone marrow samples were collected for analysis. After the whole bodies were buried, femur bone marrow specimens were collected on the seventh and fourteenth days. CEDIA was used to monitor morphine contents of the collected samples. All experimental cases showed that the increase in the given morphine doses correlated with the increase in blood and bone marrow morphine concentrations. High morphine concentrations were detected in urine samples, but there was no correlation between the urine and blood or urine and bone marrow morphine concentrations. Statistically meaningful increases in bone marrow morphine concentrations were found parallel to increase of blood morphine concentrations. Seventh and fourteenth day postmortem morphine concentrations also followed this correlation. Morphine concentrations in bone marrow at 7 and 14 day postmortem decreased consistently when compared with bone marrow morphine concentrations collected immediately after death. We conclude that in sudden death when other specimens are unavailable due to degradation, bone marrow can be a most useful specimen. Further experimental research in this area is required to validate bone marrow as an alternative tissue.     

The relationship of methanol and formate concentrations in fatalities where methanol is detected

An automated headspace gas chromatography method was developed for the determination of formate (formic acid) in postmortem specimens, based on the in situ sulfuric acid-methanol methylation of formic acid to methyl formate. Diisopropyl ether was used as an internal standard. The method was applied to over 150 postmortem cases where methanol was detected. Of the 153 cases presented, 107 deaths were attributed to acute methanol toxicity. In the vast majority of the remaining 46 deaths, the methanol was determined to be present as a postmortem or perimortem artifact, or was otherwise incidental to the cause of death. Of the 76 victims who were found dead and blood was collected by the medical examiner, all but one had a postmortem blood formate concentration greater than 0.50 g/L (mean 0.85 g/L; n = 74). The sole exception involved suicidal ingestion of methanol where the blood methanol concentration was 7.9 g/L (790 mg/100 mL) and blood formate 0.12 g/L. In 97% (72/74) of the cases where blood was available, the blood formate was between 0.60 and 1.40 g/L. In 31 of the 153 cases, the victim was hospitalized and blood obtained on admission or soon after was analyzed for methanol and formate during the subsequent death investigation; the vast majority (27/30) had antemortem blood formate concentrations greater than 0.50 g/L. Cases with samples taken prior to death with blood formate concentrations less than 0.5 g/L can readily be explained by active treatment such as dialysis. The blood formate method has also been useful in confirming probable perimortem or postmortem contamination of one of more fluids or tissues with methanol (e.g., windshield washer fluid or embalming fluid), where methanol ingestion was unlikely.     

Comparative study of ethanol levels in blood versus bone marrow,vitreous humor,bile and urine

Post-mortem ethanol levels in blood were compared to corresponding levels in rib bone marrow, vitreous humor, urine and bile. In forensic toxicology, a good correlation between blood and a tissue or body fluid is needed to estimate a blood alcohol concentration when blood is unavailable or contaminated. In this study, direct injection and headspace gas-chromatographic techniques were employed to quantitate the ethanol concentrations. Comparable findings by these two techniques showed a reproducibility of results. When the determined bone marrow ethanol levels were corrected for the lipid fraction, a consistent correlation could be established between ethanol levels in blood and bone marrow. The relationship (linearity and ratio range) between ethanol levels in blood and corrected levels in bone marrow was better than that between blood and vitreous humor, bile or urine. This study showed that blood ethanol levels can be predicted by extrapolating the corrected rib bone marrow ethanol level.     

Blood carbofuran concentrations in suicidal ingestion cases

We describe four fatal cases due to ingestion of carbofuran, a carbamate insecticide. Carbofuran was detected in the gastric contents using thin layer chromatography (TLC) and gas chromatography/mass spectrophotometry (GC/MS), and quantified in the blood using a gas chromatograph equipped with nitrogen-phosphorus detector (NPD). Fatal concentrations of carbofuran in blood ranged from 0.32 to 11.6 microg/ml.     

Determination of opiates in postmortem bone and bone marrow.

Bone and bone marrow of a fatally poisoned heroin addict were analyzed by FPIA and GC-FID, immediately after death. A piece of the bone from the above case was buried for 1 year and analyzed by the same procedure. Morphine was detected in all specimens at concentrations of 195, 340 and 155 ng/g for bone marrow, bone and buried bone, respectively. A loss of 54.4% of morphine concentration was observed during 1-year burial. Such findings have potential forensic value in cases of skeletonized remains.     

Morphine and 6-acetylmorphine concentrations in blood, brain, spinal cord, bone marrow and bone after lethal acute or chronic diacetylmorphine administration to mice

The aim of this study was to evaluate postmortem incorporation of opiates in bone and bone marrow after diacetylmorphine (heroin) administration to mice. Mice were given acute (lethal dose of 300 mg/kg) or chronic (10 and 20 mg/kg/24 h for 20 days) intraperitoneal administration of diacetylmorphine. The two metabolites of diacetylmorphine, 6-acetylmorphine (6-AM) and morphine, were extracted from whole blood, brain, spinal cord, bone marrow and bone (after hydrolysis) using a liquid/liquid method. Quantification was performed by gas chromatography-mass spectrometry (GC/MS). Results showed that after acute administration, opiates were present in all studied tissues. Morphine concentrations appeared to be higher than those of 6-AM in blood (52.4 microg/mL versus 27.7 microg/mL, n=12), bone marrow (87.8 ng/mg versus 8.9 ng/mg, n=6) and bone (0.85 ng/mg versus 0.43 ng/mg, n=6), but 6-AM concentrations were higher than those of morphine in brain (14.0 ng/mg versus 7.4 ng/mg, n=12) and spinal cord (27.8 ng/mg versus 20.8 ng/mg, n=12). No correlation was found for both compounds between blood concentrations and either brain, spinal cord, bone or bone marrow concentrations while a significant one was found between brain and spinal cord concentrations either for morphine (r=0.89, n=12, p<0.001) or 6-AM (r=0.93, n=12, p<0.001), the concentration being higher in spinal cord than in brain. When bones were stored for 2 months, only 6-AM remained in bone marrow but not in bone. After chronic administration, mice being sacrificed by cervical dislocation 24 h after the last injection, no opiate was detected in any studied tissues. Further studies are required, in particular in human bones, but these results seem to show that 6-AM could be detect in bone marrow several weeks after the death and could be an alternative tissue for forensic toxicologist to detect a fatal diacetylmorphine overdose, even if no correlation between blood and bone marrow was observed. On the other hand, neither bone tissue nor bone marrow will allow the confirmation of a chronic diacetylmorphine use.     

Determination of formic acid tissue and fluid concentrations in three fatalities due to methanol poisoning

Three fatalities caused by methanol ingestion are reported. Admission blood methanol concentrations ranged from 0.28 to 4.6 g/L. Two patients had been admitted after a significant delay (>20 hours), and one patient was observed within 90 minutes following ingestion. Formic acid levels were determined in blood samples at admission and ranged from 302 to 680 mg/L. The patients died 44, 55, and 82 hours after poisoning. Formic acid determinations in postmortem tissues were performed by a gas chromatograph method. The authors found great variability in formic acid distribution among the patients and among organs.     

Postmortem tricyclic antidepressant concentrations. Lethal versus nonlethal levels

Evidence has accumulated that postmortem release of tissue-bound tricyclic antidepressants (TCAs) may cause falsely elevated postmortem blood levels, thus rendering it more difficult to determine if the cause of death was an overdose. This study, a review of 24 TCA-related deaths, is aimed at defining the practical significance of such a problem and providing a workable approach to interpreting postmortem TCA levels. Deaths clearly due to TCA drugs were compared with deaths that were not caused by TCA drugs, but in which the decedent's postmortem blood tested positive for TCA medications. There is little evidence that postmortem elevations in blood TCA levels cause frequent problems in differentiating lethal from nonlethal levels (overdose from nonoverdose cases). The data suggest that using a heart blood level of 0.100 mg/dl as an indicator of lethality is practical at the present time and poses little likelihood of error. Isolated cases suggest that postmortem TCA increases can occur; further work is needed in this area to clarify more fully the significance and frequency of such cases. At present, it seems prudent to utilize peripheral blood samples for TCA testing on autopsy material, if a conservative estimate of TCA concentration is desired, possibly augmented by liver TCA levels and parent-metabolite ratios if money, facilities, and time permit.     

Quantitative assessment of the percent fat in domestic animal bone marrow

Measurement of the amount of fat in femoral bone marrow can provide a quantitative assessment of the nutritional status of an individual animal. An analytical method is presented for quantitating the percent fat in bone marrow from three domestic species: bovine, canine, and equine. In this procedure, fat is extracted from bone marrow using pentane, and the percent fat recovered is determined gravimetrically. Based on analyses from adult animals (normal body condition scores), the average percentage of fat in the bone marrow was >80%. In cases in which animals have been diagnosed as emaciated or exhibit serous atrophy of fat (body scores of 1 or 2), the femoral bone marrow fat was less than 20%. In domestic animals, bone marrow fat analysis can be a useful, quantitative measure that, when used in conjunction with all other data available, can support a diagnosis of starvation or malnutrition.     

A storage study of ethanol in rabbit and human bone marrow

The study reports the effect of storage on ethanol concentrations in bone marrow.     

Blood concentrations of tetracaine and its metabolite following spinal anesthesia

Blood concentrations of tetracaine and its metabolite, p-butylaminobenzoic acid, were measured after spinal anesthesia with tetracaine which had been administered to patients under going orthopedic surgery. Tetracaine, an ester anesthetic, was given to 10 patients, the dose was 8-14mg, and blood samples were collected 1, 2 and 6h after the injection of tetracaine. We used gas chromatography/mass spectrometry for purposes of analysis. Tetracaine was not detected in any blood sample, but the metabolite was detected in each sample with the mean concentrations of 126.5, 97.9 and 43.3ng/ml at 1, 2 and 6h, respectively. This data will be useful in determination of the cause of death after spinal anesthesia with tetracaine.