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PubMed2001

Proteome analysis applied to meat science: characterizing postmortem changes in porcine muscle.

The aim of this work was to test the application of two-dimensional electrophoresis (2DE)-based proteome analysis in studying muscle tissues and meat of pork, and to use this technology to characterize as many of the changes that occur in pig muscle proteins during post mortem storage of the carcass as possible. For this purpose, 2DE proved to be a powerful tool, as it is far more sensitive and shows a higher resolving power than conventional SDS-PAGE, allowing for the precise and semiquantitative recognition of approximately 1000 individual muscle proteins in every 2DE display. In this study, we have chosen to analyze the subset of muscle proteins that have molecular masses of 5-200 kDa, and can be reproducibly separated in the pH span of 4-9. By comparing 2DE patterns of muscle samples taken immediately after slaughter (time 0), as well as those taken 4, 8, 24, and 48 h post mortem, we have estimated the relative changes of individual muscle proteins during the post mortem storage of the carcass. In this paper, of these changes we report the 15 most notable.

Animals↗
PubMed1986

Postmortem changes of the dielectric properties of bovine brain tissues at low radiofrequencies.

The dielectric properties of the bovine brain grey and white matter in the frequency range from 20 kHz to 100 MHz were measured at different times following animal death. Changes in the dielectric parameters versus time are interpreted in terms of the reduction of the cell volume fraction that results from either cell disintegration or cell size reduction. Good agreement between the computer fitted parameters and the values calculated from the Maxwell-Wagner model of the static dielectric constants was found. At frequencies above 1 MHz the changes of the dielectric properties are less pronounced, confirming earlier observations made by other investigators for different species.

Animals↗
PubMed1990

Postmortem changes in the levels of monoamine metabolites in human cerebrospinal fluid.

Four monoamine metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxy-4-hydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA), were determined in the cerebrospinal fluid (CSF) of cadavers, whose causes of death had been suicidal hanging (SH) or ischemic heart failure (IHF). The concentration of DOPAC increased in parallel with the increment of the postmortem interval (PMI) (r = 0.626), whereas the concentrations of HVA, MHPG and 5-HIAA did not. The correlation coefficient was further increased by considering each cause of death separately: i.e., SH, r = 0.761; IHF, r = 0.705. These findings suggest the possible usefulness of the DOPAC level in CSF for estimating PMI.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1983

Endogenous gamma-hydroxybutyrate in rat brain areas: postmortem changes and effects of drugs interfering with gamma-aminobutyric acid metabolism.

The possibility that gamma-hydroxybutyrate (GHB), a metabolite of gamma-aminobutyric acid (GABA), may play a role in the CNS has recently come to attention. We describe here a sensitive and specific mass fragmentographic technique that allows the measurement of picomole amounts of GHB in single rat brain areas. Moreover, we show that GHB can accumulate postmortem, an effect that is blocked by the use of microwave irradiation to kill the animals. To understand further the relationship between GABA and GHB formation, we treated rats with drugs known to interfere with GABA metabolism at different levels and concomitantly measured GABA and GHB in cerebral cortex and cerebellum. Isoniazide, which blocks the formation of GABA, also decreases GHB. Blockers of the catabolism of GABA, such as aminooxyacetic acid and gamma-acetylenic GABA, increase GABA levels and decrease those of GHB. Sodium dipropylacetate increases both GABA and GHB, supporting the hypothesis that this effective antiepileptic drug also blocks in vivo the enzyme that converts succinic semialdehyde to succinic acid.

Alkynes↗
PubMed1981

Postmortem changes of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in mouse brain and their prevention by pargyline and microwave irradiation.

Postmortem (pm) manipulations of brain tissue of decapitated mice produced a maximum decline in 5-HT and a maximum rise in 5-HIAA of 20 and 40%, respectively. The pm treatments included freezing and thawing, mincing, and leaving over. Microwave irradiation or pretreatment of the animals with the enzymatic inhibitors NSD 1015 or pargyline suppressed the pm effects. The possible role of pm effects in the initial accumulation of 5-HT and decline of 5-HIAA in the brain following administration of pargyline was studied. Out data suggest that, when MAO inhibitors are used, 5-HT turnover might be overestimated by pm changes.

Animals↗
PubMed1977

[Postmortem changes of fine structure in the auditory pathways (organ of Corti and nucleus cochlearis of the guinea pig (author's transl)].

Autolytic changes in the guinea pig cochlear nucleus were studied by means of light- and transmission electron microscopy from 5 min. up to 5 h post mortem. Hyperchromasy and shrinking of neurons was observed already after 5 min. in areas, where the neurons have a high number of primary afferent nerve endings (Kane 1973). A second mode of post mortem degeneration was found. It was characterized by a swelling of the cell, which showed a diminished stain-ability. This lytic swelling seemed to be less rapid and probably less harmful in the beginning. The cochleae were examined by scanning electron microscopy. In contrary to known damaging agents (like noise or antibiotics) the outer haircells showed hardly any changes in the surface structures up to 1 hour in the basal coil, while lytic protrusions were observed in outer and inner haircells already after 5 min. in the apical parts. Post mortem changes in the cochlea and in the nucleus cochlearis show two different modes of autolytic degeneration.

Animals↗
PubMed1994

Postmortem changes in blood amitriptyline concentration.

Detailed toxicological studies were undertaken on two suicides by amitriptyline overdose, one with salicylate also. In the first case, 10 initial blood samples taken 21 h after body discovery and an estimated 28 1/2 h after overdose had drug concentration (mg/L) ranges of 2.5-12 for amitriptyline (AM), 0.7-3.1 for nortriptyline (NOR), and 81-244 for salicylate (SAL). Ten blood samples taken 42 h later showed corresponding ranges of 1-39 AM, 0.6-7.0 NOR, and 86-310 SAL. Sample haemoglobin concentrations (range, 8.7-23.5 g/dl) did not correlate with drug concentrations. Postmortem increase in pulmonary vein AM concentration occurred more rapidly than in the pulmonary artery, likely reflecting relative ease of diffusion across the vessel walls from lung (AM, 60 mg/kg). In nine tissue samples, drug concentrations (mg/kg) were highest in the liver: AM, 301; and SAL, 670. Considerable drug residue was present in gastric contents, duodenal contents, and seven sequential small bowel contents. In both cases, sanguineous putrefactive pleural fluid showed higher AM concentrations on the left than on the right (2.0 vs 1.4 and 23 vs 16), likely reflecting diffusion from gastric drug residue. The detailed case data illustrate the intensity and complexity of postmortem drug diffusion from reservoirs in solid organs, such as the lungs, and unabsorbed gastric residue, into the blood and putrefactive fluids.

Adult↗
PubMed1988

High-resolution proton magnetic resonance spectroscopy of rabbit brain: regional metabolite levels and postmortem changes.

The changes in 16 cerebral metabolites produced by cardiac arrest and subsequent room temperature autolysis were studied using high-resolution proton nuclear magnetic resonance spectroscopy. Biopsies of rabbit cerebral cortex, cerebral white matter, and cerebellum were quantitatively analyzed for acetate, alanine, gamma-aminobutyric acid, creatine, glutamate, glycine, inositol, lactate, N-acetylaspartate, phosphocreatine, succinate, taurine, and threonine. Of these, N-acetylaspartate and the total creatine pool are the best candidates for use as concentration reference standards linking in vitro to in vivo 1H nuclear magnetic resonance measurements. Both changed little immediately after death, and they varied in a distinctive way among cortex, white matter, and cerebellum.

3-Hydroxybutyric Acid↗
PubMed1996

[Postmortem changes in ear canal resonance and tympanic membrane impedance in the human ear].

BACKGROUND: The human temporal bone preparation is a common model for research of physical processes of the ear canal and middle ear. In the past decade only a few reports were published discussing changes of the vibration behaviour of the tympanic membrane, as well as the ear canal resonance, during the time between death and preparation of the temporal bone. The aim of our study is to verify whether measurements at the temporal bone of dead humans can be really applied to the in vivo situation. METHODS: We investigated whether changes of the ear canal resonance and the vibration of the tympanic membrane depend on temperature and time after death. In a female human body we defined the resonance of the outer ear and the impedance of the tympanic membrane using a tympanometer and a real ear measurement system during nine hours post mortem. RESULTS: We were able to prove that before the preparation of the temporal bone none of the parameters changed significantly. CONCLUSIONS: In conclusion, the method of preserving the bone after its preparation is decisive for the validity of measurements at the isolated (post mortem) human temporal bone.

Acoustic Impedance Tests↗
PubMedDate not supplied

[Confusing muscular hemorrhage in a drowned cadaver. A contribution to differentiation between vital and postmortem changes].

The autopsy on an body recovered from the water showed evidence of drowning and, in addition, the occurrence of extensive intramuscular bleeding on the neck, in the area of the shoulder girdle and the upper arms. There was a suspicion that criminal violence had been used, and the police carried out extensive investigations; these were inconclusive. The subsequent histological examination of the affected musculature revealed "reactive" changes throughout which corresponded to post mortem damage. The case presented here serves to illustrate the usefulness of muscle histology for differentiating between the occurrence of intramuscular bleeding before and after death; the corresponding histological criteria are outlined.

Aged↗
PubMed1990

Postmortem changes in endothelium-dependent and independent responses of porcine coronary arteries.

1. Studies were performed in porcine left circumflex coronary arteries to determine the time course of changes in their responses to smooth muscle and endothelial cell agonists following death. 2. The pigs were kept at room temperature for 3, 6, 12 and 24 hr after death before removing the arteries, and the responses compared with fresh arteries. Rings of the arteries were mounted in organ chambers filled with modified Krebs-Ringer solution for isometric tension recording. 3. Fresh rings with endothelium relaxed with stretching, whereas 3- and 6-hr rings developed an increase in tension and often rhythmic activity. In 3-hr rings, there were diminished contractile responses to KCl and serotonin. The contractile responses to prostaglandin F2 alpha were depressed at 3 and 6 hr. 4. At 6 hr, rings from six of 14 pigs failed to contract and the responses of the other eight to histamine and serotonin but not to KCl or acetylcholine, were depressed compared to fresh rings. 5. 6 hr after death endothelium-mediated relaxations to bradykinin and calcium ionophore A-23187 were depressed while endothelium-mediated as well as direct smooth muscle relaxation by adenosine diphosphate did not change. 6. These studies indicate that caution must be observed in interpreting the findings in autopsy specimens examined as early as 3 hr after death.

Acetylcholine↗
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↗
PubMedDate not supplied

[An ultrastructural analysis of the postmortem changes in the sinoauricular area of the canine heart].

The EM study of all tissues and myocyte components in the sinus node (SN) and adjacent working myocardium of the right atrium was performed in normal dogs and in dogs 1, 2, and 3 hours after death. A quantitative evaluation of the myocyte density, connective tissue components, vessels and nerve fibers in the SN and working myocardium of this region was performed. Destructive changes having mosaic appearance were observed in the conducting and working myocytes, myelinated and non-myelinated, nerve fibers, in vessels and partly in components of connective tissue of both SN and working myocardium. Possible mechanism of development of the ultrastructural pathology in the sinoauricular region of the heart during autolysis are discussed.

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↗