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PubMed1990

An experimental model of death from anaphylactic shock with compound 48/80 and postmortem changes in levels of histamine in blood.

The present study was made on an experimental animal model of a death from anaphylaxis, in which postmortem changes in levels of histamine and 1-methylhistamine, in whole blood were measured. Instead of the usual immunological method administering compound 48/80, a degranulating agent of mast cell and the effect closely resembling the immuno-reaction, resulted in reliable death in a short time. The animals that died rapidly after the injection of compound 48/80, were found to have large increases in levels of histamine and 1-methylhistamine soon after the administration. These results were similar to the results of injecting histamine exogenously. On the other hand, the animals that died after a longer time showed no increases in levels of those amines within about 24 h, but 24 hours after death histamine levels were only increased tremendously without rise in 1-MHA levels. These phenomena closely resembled those in the control animals that were treated with overdoses of Nembutal.

Adult↗
PubMed1976

[Postmortem changes in the endothelial contour of the surface of large human arteries].

Changes in the relief of the endothelial surface of the common carotid artery common iliac artery in man in the postmortem period were studied by the method of scanning electron microscopy. It is established that the normal relief of the inner surface of the vessels could be studied only during the first few hours after death. Rapidly developing postmortem changes lead to drastic distortion of the stratified endothelial surface and to desquamation of the endothelial lining. On the 2nd and 3rd day of the postmortem period the relief of the inner surface of the vessel is determined by the elements which are incorporated into the composition of the subendothelial layer of the intima.

Carotid Arteries↗
PubMed1984

Postmortem changes of uric acid in various rat tissues: determination of uric acid by reversed-phase high-performance liquid chromatography with electrochemical detection.

As a function of time after decapitation, postmortem changes of uric acid in various rat tissues have been studied by reversed-phase high-performance liquid chromatography with electrochemical detection. The chromatographic examination revealed that uric acid in rat tissues such as brain, liver, musculus rectus abdominis, and femoral muscle tends to increase after decapitation as a function of time between the sacrifice and homogenization in a 2.0% metaphosphoric acid solution.

Animals↗
PubMed1993

Postmortem changes in resistivity of the anterior abdominal wall during the early postmortem period in rats.

An accurate and reproducible technique was employed for the determination of the resistivity of excised portions of the anterior abdominal wall of rats. Resistivity decreased linearly (r = -0.93; P < 0.001) from 1438 +/- 131 omega.cm, immediately following death, to 360 +/- 144 omega.cm at a postmortem interval of 36 h. These changes are believed to reflect the morphological and/or chemical changes which occur at the cellular level during the early postmortem period.

Abdominal Muscles↗
PubMed2000

The use of microscopic postmortem changes in anagen hair roots to associate questioned hairs with known hairs and reconstruct events in two murder cases.

In two cases investigated by the New Orleans Police Department Crime Lab, hairs recovered from crime scenes were found to exhibit microscopic postmortem changes in anagen hair roots. These microscopic characteristics were used to associate these hairs with various victims in the cases. In addition to associating questioned hairs with known hairs, the fact that the victims were dead when the hairs were pulled helped investigators reconstruct events in both crimes and corroborate statements made by the arrested subjects in each case.

Adult↗
PubMed1993

Critical evaluation of postmortem changes in human autopsy cisternal fluid. Enzymes, electrolytes, acid-base balance, glucose and glycolysis, free amino acids and ammonia. Correlation to total brain ischemia.

By studying early postmortem changes in cerebrospinal fluid (CSF) it is possible to draw conclusions as to premortem focal brain cell injury and terminal brain ischemia. Cisternal fluid (CF) from 40 different adult cadavers with no known neurological disorder was analyzed and compared with known in vivo values. They were divided into four groups (n = 10 in each group), CF samples taken 2, 4, 10, and 24 h after death. The enzyme activity of CK and CK-BB (EC 2.7.3.2) increased linearly and statistically significantly 4-24 h postmortem (P < 0.001) the 2 h values being already 10 to 20 times higher than in vivo, LD and its isoenzymes 1 to 3 (EC 1.1.1.27) distinctly 10 to 24 h after death. Glucose and pyruvate concentrations in the CF declined, as did Na+ and Cl-. Lactate and K+ increased over time. The earliest statistically significant changes between different timepoints were seen in lactate, pyruvate and K+ concentrations. The GABA concentration was already more than 170 times at 2 h postmortem, and glutamate more than 20 times higher than in vivo. The concentrations of alanine, glycine, lysine, histidine, isoleucine, phenylalanine, and tyrosine were 2 to 3 times higher at 2 h postmortem than during life. The concentrations of all amino acids and ammonia increased linearly and statistically significantly (P < 0.001) in the CF 4 to 24 h postmortem.

Acid-Base Equilibrium↗
PubMed1999

[Histological study of early postmortem changes in various organs: comparison of the paraffin embedding method and the epoxy resin embedding method].

For the purpose of morphological assessment of the early postmortem interval, Wistar rats were killed by cervical dislocation and left at 23 degrees C for 1, 3, 5, 10, 15 and 24 hours. After a given postmortem interval, tissue samples taken from kidney, pancreas, liver, heart and skeletal muscle were embedded in paraffin or epoxy resin and examined by light microscopy. Specimens obtained from the paraffin block did not show a good correlation between histological changes and postmortem interval, because the postmortem changes continued during the fixation period. On the other hand, the time course of histological changes in specimens obtained from the epoxy block, particularly the development of clumping of nuclear chromatin and cytoplasmic vacuolation in each organ, reflected the postmortem interval because of the rapid fixation by glutaraldehyde. These histological changes were characteristic of each organ up to 24 hours after death. In addition, the semithin epoxy resin section made high-resolution light microscopy possible. Therefore, the epoxy resin embedding method is superior to the paraffin embedding method for the purpose of estimation of the time of death. The morphological changes characterising time after death are as follows: at 1 hour after death, cytoplasmic vacuolization and slight clumping of nuclear chromatin in pancreatic acinar cells; at 3 hours after death, slight clumping of nuclear chromatin in distal tubules, cytoplasmic vacuolization in skeletal muscle, and edema in cardiac muscle; at 5 hours after death, clumping of nuclear chromatin in proximal tubules as well as distal tubules, and cytoplasmic vacuolization in hepatocytes; at 10 hours after death, edema in proximal tubules, condensation of nuclear chromatin (apoptosis) and edema in distal tubules, and atrophy of acinar cells in the pancreas; at 15 hours after death, cytolysis of distal tubules; at 24 hours after death, cytolysis of hepatocytes and clumping of chromatin in skeletal muscle. Thus we can conclude that the time course of histological changes is useful for the estimation of postmortem interval.

Animals↗
PubMed1987

Mitochondrial DNA of the extinct quagga: relatedness and extent of postmortem change.

Sequences are reported for portions of two mitochondrial genes from a domestic horse and a plains zebra and compared to those published for a quagga and a mountain zebra. The extinct quagga and plains zebra sequences are identical at all silent sites, whereas the horse sequence differs from both of them by 11 silent substitutions. Postmortem changes in quagga DNA may account for the two coding substitutions between the quagga and plains zebra sequences. The hypothesis that the closest relative of the quagga is the domestic horse receives no support from these data. From the extent of sequence divergence between horse and zebra mitochondrial DNAs (mtDNAs), as well as from information about the fossil record, we estimate that the mean rate of mtDNA divergence in Equus is similar to that in other mammals, i.e., roughly 2% per million years.

Animals↗
PubMed2002

G protein-coupled receptor kinases, beta-arrestin-2 and associated regulatory proteins in the human brain: postmortem changes, effect of age and subcellular distribution.

G protein-coupled receptor kinases (GRKs) and beta-arrestin-2 play a crucial role in the regulation of neurotransmitter receptors in brain. In this study, GRK2, GRK6, beta-arrestin-2 and associated regulatory proteins (Gbeta proteins and protein phosphatase (PP)-2A) were quantitated in human brains (immunodensity with specific antibodies) to assess for postmortem changes (pattern of protein degradation) and to investigate the effect of aging on these regulatory proteins as well as their subcellular distribution (cytosol and membrane fractions). In brain (prefrontal cortex, total homogenate) of healthy subjects (n=14) the immunodensities of GRK2 (r=-0.76), GRK6 (r=-0.64), beta-arrestin-2 (r=-0.57), Gbeta proteins (r=-0.59) and neurofilament (NF)-L (r=-0.64), but not PP-2A, declined markedly with the length of postmortem delay (PMD, 3-81 h). With these linear decay models, the average decreases per 12 h of PMD (from 12 to 72 h) were 7-11% for the various proteins. The immunodensities of GRK2 (r=-0.71), GRK6 (r=-0.61), and beta-arrestin-2 (r=-0.54) in human brain (n=12) also declined with aging (16 to 87 years) and the average decreases per decade (from 20 to 80 years) were 3-5%. In contrast, the immunodensities of PP-2A, Gbeta and NF-L in brain did not correlate significantly with the age of the subject at death (16-87 years). The immunodensities of GRK2/6 and beta-arrestin-2 showed marked individual variations and were strongly reduced after several freeze/thaw cycles. In the prefrontal cortex the subcellular distribution (cytosol/membrane) of the two GRKs differed markedly (GRK2: 60%/40%; GRK6: 5%/95%), and that of beta-arrestin-2 was as expected for a soluble protein (60%/40%). In brains of healthy subjects, the immunodensities of cytosolic GRK2 and beta-arrestin-2 correlated, respectively, with those of membrane-associated GRK2 (r=0.67, P=0.049, n=9) and membrane-associated beta-arrestin-2 (r=0.77, P=0.01, n=9). The results of this study emphasize the importance of examining relevant variables (PMD, age) and potential artifacts (individual variation, freeze-thawing effect) when designing signal transduction studies in neuropsychiatric disorders using the postmortem human brain.

Adolescent↗
PubMed1993

Species differences in dopamine transporters: postmortem changes and glycosylation differences.

The apparent molecular masses of photoaffinity-labeled dopamine transporters (DATs) from rat, human, dog, and primate kidney COS cells expressing the rat DAT1 cDNA differ. Sequences predicted from cDNA cloning reveal only one amino acid difference between the length of the rat and human DAT but one less site for potential N-linked glycosylation in the human DAT. Possible posttranslational and postmortem bases for species differences in DAT molecular mass were explored. Rat DAT proteins from striata subjected to approximately 5 h of postmortem delay modeled after the human postmortem delay process revealed small but consistent losses in apparent molecular mass and in cocaine analogue binding; the DAT molecular mass displayed no further losses for up to 30 h of model postmortem treatment. Degradative postmortem changes could thus contribute to molecular mass differences between rat and human DATs. Neuraminidase treatment reduced the apparent molecular mass of native rat DAT but not that of the rat DAT expressed in COS cells, suggesting that the sugars added to the DAT expressed in COS cells were different than those added to the rat brain striatal transporter. These differences could account for the somewhat higher Km values for expressed DAT cDNA in COS cells when compared with the wild-type striatal transporter. These results are in accord with the differences in number of predicted N-linked glycosylation sites between rat and human DATs and with cell-type specificity in transporter posttranslational processing.

Affinity Labels↗
PubMed1983

[Dynamics of postmortem changes in the adrenergic nerve fibers of the cerebral arteries].

The authors studied the changes in the quantity and intensity of adrenergic nerve fiber fluorescence in the rat and human brain arteries every two hours after death at varying temperatures of keeping cadavers (18-20, 10, 4 degrees C). It was established that the differences in the temperatures had an appreciable effect on the duration of complete exposure of nerve fibers as compared with control. No significant reduction in the number of fluorescent conductors was seen for the longest period of time (up to 10 h in rats and up to 8 h in man) at a temperature of 4 degrees C. The relationships are defined between postmortem changes in nerve fiber fluorescence and their number under varying temperatures.

Adolescent↗
PubMed1997

Influence of postmortem changes on immunohistochemical reactions in skin.

The influence of postmortem damage of tissues on the immunohistochemical diagnosis of wound age has not as yet been clarified. We utilized antibodies against the proteinase inhibitors alpha-1-antichymotrypsin and alpha-2-macroglobulin, fibronectin and lysozyme to study samples of skin which had been intact intravitally, but were damaged postmortem either by autolysis or compression with a surgical clamp at the time of dissection. Even in the absence of autolysis, antibodies against the proteinase inhibitors and fibronectin exhibited staining of tissue margins. Autolysis caused an increase in false positive results. In contrast, antibodies against lysozyme did not give false positive staining. There were no antigens sensitive to postmortem clamping and false positive results were not observed. Antibodies against proteinase inhibitors are not useful for the diagnosis of wound age because of a high number of false positive reactions in marginal areas. Fibronectin also showed false positive band-shaped staining patterns at the tissue margin. In addition, autolytic processes increase the number of false positives. The antibody against lysozyme is much less sensitive to autolysis and no false positive reactions were observed in our series of tests.

Fibronectins↗
PubMed1991

Site-dependent postmortem changes in blood cocaine concentrations.

When a forensic toxicologist interprets postmortem blood cocaine findings he usually must make assumptions regarding perimortem drug concentrations. In-vitro studies have shown that cocaine rapidly hydrolyzes in unpreserved blood, particularly at elevated temperatures. However, other studies have demonstrated site-dependent postmortem release of some drugs from tissue stores accompanied by increases in drug concentrations in the blood. This study was undertaken to investigate whether blood cocaine concentrations change in the body during the postmortem interval and, if so, to measure the direction and magnitude of the changes. In medical examiner cases in which scene investigation suggested that the decreased was a cocaine user, blood samples were collected as soon after death as possible. At autopsy, a second set of samples was collected. Analysis of paired samples by gas chromatography/mass spectrometry (GC/MS) revealed dramatic differences in the cocaine concentration. The magnitude and direction of the change appears to be site dependent. Usually, but not invariably, cocaine concentration in subclavian vein blood decreases while that in heart, aorta, and femoral vein blood increases during the interval between death and autopsy. The findings emphasize the danger inherent in attempting to estimate the concentration of cocaine in blood at the time of death from postmortem data.

Adolescent↗
PubMed2005

Gross and histologic postmortem changes of the skin.

Many methods have been attempted to accurately and systematically determine the estimated time of death in autopsy cases. Gross changes of the skin which occur during the postmortem interval have occasionally been used to estimate the time of death under different conditions; however, the postmortem gross and histologic changes of the skin have not been systematically analyzed. We sequentially studied the gross and microscopic appearance of skin in 3 individuals during the early postmortem interval (<1 week) in an outdoor, shaded, cool to temperate climate. Photos and skin biopsy specimens were taken from 4 sites (acral skin, scalp, dependent truncal skin, and nondependent truncal skin) every 12-24 hours on each individual. The gross appearance of the skin remarkably did not change significantly in any of the sites after 1 week of decomposition. Three main histologic changes were seen in the skin biopsy specimens: focal dermal-epidermal separation, eccrine duct necrosis, and dermal degeneration. Although bullae were not present in the gross examination of the skin, focal separation of the epidermis from the dermis was appreciated in several skin biopsies; however, the timing of development was unpredictable. Eccrine duct necrosis was another histologic finding and was relatively predictable, occurring in dependent and nondependent truncal skin biopsies from all 3 individuals between days 4 and 7. Dermal degeneration was a uniform histologic finding only in biopsies from nondependent truncal skin, occurring in all individuals on day 2. Although this study is limited by the small number of subjects and uncontrolled extrinsic factors, histologic findings, such as eccrine gland necrosis and dermal degeneration, in select cutaneous biopsies may be useful in estimating the time of death in the early postmortem interval.

Aged↗
PubMed1998

[Effect of postmortem change on detection of apoptosis in rats].

Terminal deoxynucleotidyl transferase(TdT)-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay is useful to detect apoptotic cells in situ. We examined by hematoxylin-eosin (H-E) and TUNEL assay whether or not postmortem delay affects the development of apoptotic signals of cells in various organs. Wistar Imamichi rats were radiated by X-ray and sacrificed six hours after radiation. The spleen, thymus, adrenal and testis were excised and kept in a moist chamber at room temperature. Each tissue was fixed after different time intervals 0, 6, 12, 24 hours and paraffin-embedded sections were made. In the no-radiation group, a few of TUNEL positive cells were observed in the spleen, thymus and testis sections, but not in the adrenal. No increase in the number of apoptotic cells was observed with postmortem delay. In the radiation group, we observed in the spleen and thymus, much increase in the number of TUNEL positive cells, of which nuclei were clearly and deeply stained, corresponding to the area where shrinking nuclei were observed in H-E section. In testis sections, there was a little increase in the number of positively stained cells, and no change was observed in H-E section. With postmortem delay, the margin of the TUNEL positive cells changed from clear to indistinct, and the positive area was spread around. Our results show that it is difficult to distinguish apoptotic cells from postmortem change. It is possible, however, to detect TUNEL positive cell together with postmortem changes as the spread of the TUNEL positive area after 24 hours postmortem delay. It is important to consider the effect of the postmortem change when we adapt TUNEL assay to autopsy cases.

Animals↗