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PubMed1991

Molecular species of diacylglycerols and phosphoglycerides and the postmortem changes in the molecular species of diacylglycerols in rat brains.

The molecular species of 1,2-diacyl-sn-glycerol (DAG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), phosphatidylinositol 4-phosphate (PIP), and phosphatidylinositol 4,5-bisphosphate (PIP2) from brains of adult rats (weighing 150 g) were determined. The DAG, isolated from brain lipid extracts by TLC, was benzoylated, and the molecular species of the purified benzoylated derivatives were separated from each other by reverse-phase HPLC. The total amount and the concentration of each species were quantified by using 1,2-distearoyl-sn-glycerol (18:0-18:0) as an internal standard. About 30 different molecular species containing different fatty acids at the sn-1 and sn-2 positions of DAG were identified in rat brains (1 min postmortem), and the predominant ones were 18:0-20:4 (35%), 16:0-18:1 (15%), 16:0-16:0 (9%), and 16:0-20:4 (8%). The molecular species of PC, PE, PS, and PI were determined by hydrolyzing the lipids with phospholipase C to DAG, which was then benzoylated and subjected to reverse-phase HPLC. PIP and PIP2 were first dephosphorylated to PI with alkaline phosphatase before hydrolysis by phospholipase C. The molecular species composition of phosphoinositides showed predominantly the 18:0-20:4 species (50% in PI and approximately 65% in PIP and PIP2). PS contained mainly the 18:0-22:6 (42%) and 18:0-18:1 (24%) species. PE was mainly composed of the 18:0-20:4 (22%), 18:0-22:6 (18%), 16:0-18:1 (15%), and 18:0-18:1 (15%) species. In PC the main molecular species were 16:0-18:1 (36%), 16:0-16:0 (19%), and 18:0-18:1 (14%). Studies on postmortem brains (30 s to 30 min) showed a rapid increase in the total amount (from 40-50 nmol/g in 0 min to 210-290 nmol/g in 30 min) and in all the molecular species of DAG. Comparatively larger increases (seven- to 10-fold) were found for the 18:0-20:4 and 16:0-20:4 species. Comparison of DAG species with the molecular species of different glycerolipids indicated that the rapid postmortem increase in content of DAG was mainly due to the breakdown of phosphoinositides. However, a slow but continuous breakdown of PC to DAG was also observed.

Animals↗

PubMed1991

[Postmortem changes after 50 years immersion (1939 reconstructed suicide)].

In September 1989 an old motor car was accidentally discovered in a lake, 50 meters below the water surface. The automobile contained the torso of an adult woman with extensive adipocere formation and the skeletonized body of a man. Forensic and criminalistic investigations lead to the identification of the deceased persons. In the year 1939 the persons together had committed suicide. The corpses were immersed for fifty years.

Adult↗

PubMed1998

NADPH diaphorase-containing nerve fibers and neurons in the myenteric plexus are resistant to postmortem changes: studies in Hirschsprung's disease and normal autopsy material.

OBJECTIVE: Nitric oxide is considered to be the most important messenger of inhibitory nonadrenergic, noncholinergic nerves in the enteric nervous system. Histochemical studies have shown that nitric oxide synthase is identical to reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase. Histochemical staining with NADPH diaphorase has been widely used to study nitrergic innervation of the gastrointestinal tract, but fresh tissue is considered a prerequisite for satisfactory results. The purposes of this study were to evaluate whether whole-mount specimens of human bowel obtained after death are suitable for histochemical staining with NADPH diaphorase and to compare the staining properties with those of specimens of resected bowel from patients with Hirschsprung's disease METHODS: Whole-mount preparations of the myenteric plexus were examined using NADPH diaphorase histochemical staining of bowel specimens obtained at autopsy from 18 pediatric subjects (31 specimens). Fresh tissue was also obtained from the colon of four patients with Hirschsprung's disease. The staining properties of postmortem specimens were assessed in relation to the postmortem time before fixation (<12 hours, 13-24 hours, or 25-48 hours) and were compared with those of specimens of ganglionic bowel from patients with Hirschsprung's disease. Specimens of aganglionic bowel were also stained and examined. RESULTS: Strong NADPH diaphorase staining was achieved in 26 of the 31 postmortem bowel specimens, including all specimens from patients who underwent autopsy 25 to 48 hours after death. Staining properties were similar to those obtained in ganglionic bowel specimens from patients with Hirschsprung's disease. In aganglionic bowel the normal myenteric plexus meshwork was absent and was replaced by weakly staining nerve fibers. CONCLUSION: Histochemical staining with NADPH diaphorase is a robust technique suitable for use with whole-mount preparations to demonstrate nitrergic innervation in motility disorders such as Hirshsprung's disease. The technique may be used with both fresh tissue and specimens obtained up to 48 hours after death.

Child↗

PubMed1988

Postmortem changes in the level of calcium pumping adenosine triphosphatase in rat heart sarcoplasmic reticulum.

The activity of calcium pumping adenosine triphosphatase (Ca2+-ATPase) in cardiac sarcoplasmic reticulum plays a pivotal role in myocardiac contraction-relaxation. The Ca2+-ATPase activity is controlled by phosphorylation and dephosphorylation of a sarcoplasmic reticulum protein "phospholamban" in response to neurotransmitters and drugs. To clarify the role of Ca2+-ATPase in the development of cardiac rigor mortis, we examined the changes of cardiac rigidity and cardiac sarcoplasmic reticulum Ca2+-ATPase activity up to 5 h after the decapitation of rats. Fifteen minutes after decapitation, the rats showed a cardiac rigidity on left ventricles. After 30 min, rigidity was obvious over the whole heart. After 1 h, the rigidity reached a high degree which was maintained for the rest of the observation period. On the other hand, the Ca2+-ATPase activity controlled by phosphorylation and dephosphorylation of phospholamban did not change for the whole observation period (5 h). Another Ca2+-ATPase activity representing the total amount of Ca2+-ATPase in sarcoplasmic reticulum gradually decreased. The data suggest that no significant phosphorylation or dephosphorylation of phospholamban occurs for a short time, at least for 5 h, after death and that the Ca2+-ATPase tends to relax the myocardium against the development of cardiac rigor mortis.

Animals↗

PubMed1991

Postmortem changes in rat brain extracellular opioid peptides revealed by microdialysis.

Microdialysis combined with a solid-phase radioimmunoassay was used to monitor changes in extracellular opioid peptide levels in the rat globus pallidus/ventral pallidum as a result of terminal brain ischemia. Ischemia was induced by anesthetic overdose or by severance of blood vessels supplying the brain. In control animals the recovered immunoreactivity increased an average of 13-fold in the 30-min sample following anesthetic overdose. Perfusion of a calcium-free, 10 mM EGTA-containing medium through the dialysis probe significantly attenuated the amplitude of this response, with the average increase being only threefold. Shorter sampling intervals (5 min) indicated that release of opioid peptide material into the extracellular environment occurs within the first 5 min of ischemia resulting from severance of the blood supply to the brain. HPLC analysis identified the majority of the postmortem-induced immunoreactive material as Met- and Leu-enkephalin.

Anesthetics↗

PubMed1991

Postmortem changes in hapten-specific IgE antibody responses in mice.

This Study was carried out to examine the post-mortem stability of hapten-specific immunoglobulin E (IgE) antibody in mice by the passive cutaneous anaphylaxis test in rats. In vitro IgE antibody responses in blood were stable for 3 days at room temperature. Even in cases when blood could not be obtained from the cadaver it was possible to measure the hapten-specific IgE antibody response up to 3 days after death using the supernatant of the visceral homogenates.

Animals↗

PubMed1981

Postmortem changes of normetanephrine determined by a mass-fragmentographic technique in different rat brain areas.

A specific and sensitive gas chromatographic-mass spectrometric assay for measurement of normetanephrine (NMN) in different rat brain regions is presented. The results show that hypothalamus contains the highest concentrations of the norepinephrine metabolite. An increase of NMN concentrations has been detected in animals killed by decapitation in comparison with microwave-irradiated rats. This finding has to be taken into consideration when NMN is measured in the brain in order to assess the functional activity of noradrenergic neurons.

Animals↗

PubMed1994

Susceptibility of C5b-9(m) to postmortem changes.

C5b-9(m) is a specific and sensitive marker for myocardial cell necrosis. The diagnostic value of this marker would be considerably limited in forensic practice if its immuno-histochemical demonstration were hampered by putrefaction or autolysis. We could demonstrate C5b-9(m) immunohistochemically in necrotic myocardium due to infarction up to the 11th day of experimentally induced putrefaction and autolysis, when reliable demonstration of myocardial infarction with hematoxylin-eosin was no longer possible. Under the experimental conditions of this study, no false positive immunohistochemical staining occurred.

Bias↗

PubMed1987

Importance of postmortem changes in measurements of thyroid function in studies of sudden infant death syndrome.

Various measurements of thyroid function were made from serum sampled at necropsy by cardiac puncture in adults and compared with the equivalent values before death. There were significant increases in serum total T3 (0.66 before death, 1.14 nmol/l after death), free T3 (0.82 to 1.52 pmol/l), and reverse T3 (1.12 to 1.75 nmol/l); and significant decreases in total T4 (73.7 to 56.6 nmol/l), free thyroxine index (FTI) (83.2 to 56.6), and free T4 (14.2 to 11.9 pmol/l). The increase in serum T3, presumably from T4 deiodination after death, observed in this study may explain the increased T3 concentration reported in serum sampled from cases of sudden infant death syndrome (SIDS).

Humans↗

PubMedDate not supplied

[The dynamic postmortem changes of the nucleoproteins in the tissues of the liver and eye].

Postmortal changes in nucleoproteins were examined in the hepatocytes and anterior corneal and crystalline lenticular epithelial cells from 106 cadavers within 48 h after death by microfluorometry. Cryostat tissue sections were stained by acridine yellow by the method of R. Rigler (1966). The author found a natural decrease in fluorescence intensity of the examined tissue cellular nuclei at 530 nm within 4-24 h. and an increase in their fluorescence intensity at 640 nm within 4-48 h. after death. Data obtained may be used to establish the time of death.

Acridine Orange↗

PubMed1998

Diabetes and decomposition: a case of diabetic ketoacidosis with advanced postmortem change.

The case is presented of a 34-year-old man, an insulin-dependent diabetic, who was found decomposed in his apartment. The victim had been recently discharged from a mental hospital and was to be monitored by the community's mental health personnel. While the autopsy revealed little in the way of disease, toxicological studies yielded a blood acetone level of 0.070 g/dl and a urine acetone level of 0.086 g/dl. The medical examiner ruled the cause of death diabetic ketoacidosis. To support this conclusion in the absence of a vitreous humor glucose concentration, 18 well-documented cases of diabetic ketoacidosis were reviewed, and acetone concentrations were compared with the acetone concentrations found in the presented case.

Acetone↗

PubMed1983

Postmortem changes in binding to the muscarinic receptor from human cerebral cortex.

The effects of storage at 4 degrees C on the antagonist and agonist binding properties of the muscarinic acetylcholine receptor from fresh surgical and frozen autopsy samples from human cerebral cortex were studied. The number of L-[3H]3-quinuclidinyl benzilate binding sites and their affinities were stable up to 51 h, both when stored as pieces of intact nonfrozen tissue and as a homogenate. The agonist binding properties as measured by the ability of the muscarinic agonist carbachol to compete with L-[3H]3-quinuclidinyl benzilate were also stable up to 51 h when the tissue was stored in the form of pieces. The affinity for carbachol decreased when the tissue was stored as a homogenate. The frozen autopsy samples showed no significant differences in binding properties in comparison with fresh neurosurgical tissue.

Aged↗

PubMedDate not supplied

A comparative study of analytical methods to determine postmortem changes in carbon monoxide concentration.

Twenty-one autopsy blood samples were analyzed using spectrophotometric and gas chromatographic procedures after storage for 30 and 150 days. When carboxyhemoglobin was measured spectrophotometrically at the absorbance ratio of 540 nm/555 nm, the observed average percent losses were 8 +/- 9% and 35 +/- 27% after 30 and 150 days of storage, respectively. When measured at the absorbance ratio of 540 nm/579 nm, the average percent losses of carboxyhemoglobin were 7 +/- 8% and 34 +/- 25% after 30 and 150 days, respectively. Wavelength shifts and distorted spectral scans were observed at 150 days. When carbon monoxide was determined by gas chromatographic methods based on combining capacity, the average percent loss was 15 +/- 24% and 37 +/- 36% after 30 days and 150 days, respectively. The average percent loss of calculated CO based on hemoglobin concentration after 30 days was 31 +/- 14% and at 150 days, 40 +/- 24%. The average percent loss of calculated CO based on iron content was 23 +/- 13% and 37 +/- 23% after 30 and 150 days, respectively.

Carbon Monoxide↗

PubMed1981

Postmortem changes of amino compounds in human and rat brain.

Contents of 35 amino acids and related compounds were measured in whole rat brain, and in superficial areas of biopsied and autopsied human brain, after incubation for various intervals at temperatures simulating those likely to occur in cadavers under mortuary conditions. These data should aid interpretation of values for amino compounds determined in autopsied brain from patients with neurological or psychiatric disorders. The contents of glutamic acid, glutamine, taurine, phosphoethanolamine, cystathionine, and homocarnosine remain unchanged for long periods in human brain. Aspartic acid content is stable for 4 h after death, but thereafter rises rapidly. Glycine content rises rapidly, as do the contents of most amino acid components of proteins. Glutathione content drops rapidly in human brain after death. GABA content is stable for about 30 min, and rises to a maximum 2 to 3 h after death, after which it remains unchanged for at least 24 h. In rat brain, GABA content rises more rapidly, aspartate content rises more slowly, homocarnosine content decreases progressively, and glycerophosphoethanolamine content decreases more rapidly than in human brain.

Amines↗

PubMed1986

Postmortem changes in uric acid and ascorbic acid in human cerebral cortex tissues excised after cardiac death.

There has been no report on the determination of uric acid (UA) in human brain and heart tissues. UA and ascorbic acid (AA) in human cerebral cortex and heart tissues excised after cardiac death have been studied by reversed-phase high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). It has been found that the levels of AA and UA in the human cerebral cortex tissues tend to decrease and increase, respectively, after cardiac death as a function of time between death and forensic operation. In addition, it has been found that there is no special relationship between UA levels in human heart tissues and time after cardiac death, also that the UA levels in the heart are high as compared with those in human cerebral cortex tissues. We have emphasized that the HPLC-ECD method is useful in determining UA and AA in mammalian tissues by one-time chromatography to gain a better understanding of the relationship between disease and serum urate level.

Ascorbic Acid↗

PubMed1993

Rapid postmortem changes of rat striatum dopamine, serotonin, and their metabolites as monitored by brain microdialysis.

Brain microdialysis was used to monitor changes in extracellular dopamine (DA), serotonin (5-HT), and their metabolite levels in the rat striatum at death by cervical dislocation. Maximum respective 450-fold and 150-fold increases in the extracellular output of DA and 5-HT were observed within the first 30 min of death. DA and 5-HT outputs remained elevated over the following 2 h at levels about 100-fold and 50-fold above pre-death values, respectively. In contrast with monoamine outputs, the outputs of the DA metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), and the 5-HT metabolite, 5-hydroxyindoleacetic acid (5-HIAA), rapidly decreased by 10% and 20%, respectively 1 h after death. 5-Hydroxytryptophol (5-HTOL) gradually decreased after death. Before death both the extracellular DOPAC/DA and 5-HIAA/5-HT ratios were about 400; after death these ratios dropped to 0.56 and 4.0, respectively at 30 min. These observations suggested that regulation of neurotransmitter releases through the neuronal membrane and metabolisms in the rat striatum were seriously disrupted at death. This finding may be helpful in the determination of death in the field of forensic medicine.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1987

Postmortem changes in rat brain: studies on membrane-bound enzymes and receptors.

The relationship between the stability of potential neurochemical markers and autolysis time was studied at 4 degrees C and 25 degrees C using postmortem brain samples from two rat strains. In general, qualitatively similar results were obtained with either N/Nih or Sprague-Dawley rats; however, quantitative differences were often observed, particularly in regard to benzodiazepine receptor changes. For every enzyme activity or binding property examined, no significant change was found when brains were kept at 4 degrees C for up to 72 h prior to freezing at -70 degrees C. Na,K-ATPase and low-affinity Ca-ATPase activities were also stable in brains kept at 25 degrees C for up to 72 h. Mg-ATPase activity was reduced in brains kept at 25 degrees C for 24 and 48 h. [3H]Guanidinoethylmercaptosuccinic acid [( 3H]GEMSA) binding to enkephalin convertase in the cytosol was not significantly changed in brains kept at 25 degrees C; however, a small increase was seen for [3H]GEMSA binding to the membrane fraction at 24, but not 48 and 72 h postmortem. [3H]Quinuclidinyl benzilate [( 3H]QNB) binding to muscarinic cholinergic receptors decreased in brains kept at 25 degrees C for 72 h. Opioid receptor binding also decreased in brains kept at 25 degrees C. Using [3H]2-D-alanine-5-D-leucine enkephalin to label delta opioid receptors, a statistically significant decrease in binding was observed as early as 6 h postmortem, and was completely abolished after 72 h at 25 degrees C. In contrast, [3H]naloxone binding was unchanged after 24 h at 25 degrees C, but was decreased after 48 and 72 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1980

Postmortem changes in stereological parameters of cerebral neurons.

The form and size of neurons in the cat cerebral cortex were stereologically investigated intravitally, and 30 sec., 5 hours, and 22 hours postmortem. For comparison, the human cerebral cortex of a 60 year old male subject was deep frozen 16 hours postmortem, and fixed in formalin. The stereologic parameters of the cat experiment included neuronal surface Ai, perimeter LPi, and formfactor fi. In our experiment, the neurons showed swelling and metachromasia 30 sec. postmortem, which disappeared with progressive autolysis. Postmortem neuronal swelling was attributed to circulatory disturbances in the course of fatal cardiac arrest, whereas metachromasia of nucleoli and Nissl bodies appeared together with increased lysosomal acid phosphatase activity. "Dark neurons were only found in the human cerebral cortex fixed by immersion, and are thus recognized as artefact due to fixation. The intravital occurence of "dark" neurons could not be excluded, however. Size and form determinations of the neuronal perikaryon are expected to give additional information on pathologic changes during the aging process of the human brain, especially in senile dementia and organic brain syndrome.

Acid Phosphatase↗