Focussed microwave radiation: a technique to minimize post mortem changes of cyclic nucleotides, dopa and choline and to preserve brain morphology.
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Acetylcholine↗
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Proteome analysis of early post-mortem changes in two bovine muscle types: M. longissimus dorsi and M. semitendinosis.
To study early post-mortem changes in muscle tissues from bull calves, cytosole proteins from two muscles: M. longissimus dorsi (LD) and M. semitendinosis (ST) at 0 and 24 h after slaughter were analysed by 2-DE. Principal component analysis (PCA) and rotation testing were used to analyse the protein patterns in the two muscles in order to select protein spots that were significantly different at the two time-points. Selected proteins were identified by MALDI-TOF/TOF. Five proteins, namely cofilin, lactoylglutathione lyase, substrate protein of mitochondrial ATP-dependent proteinase SP-22, HSP 27 and HSP20, were changed in both LD and ST muscles during post-mortem storage. Fifteen additional protein changes were observed in either LD or ST muscles, and some of these changes have not previously been observed to change during post-mortem storage of bovine muscles. Further studies will reveal the relevance of these biomarkers for meat quality.
Animals↗
Non-enzymatic weakening of myofibrillar structures during conditioning of meat: calcium ions at 0.1 mM and their effect on meat tenderization.
The tenderness of meat is set by the properties of connective tissue and myofibrils. Skeletal muscle connective tissues become firm with chronological aging concomitantly with the increase in intermolecular non-reducing cross-links of collagen, and this process toughens meat, however, connective tissues hardly change during conditioning of meat. Therefore, the tenderization of meat during post mortem aging, or to put it more precisely, during post rigor aging, stems for the most part from changes in myofibril structures. My research derives its origin on findings of two kinds of post mortem changes in myofibril structures; i) fragmentation of myofibrils; and ii) restoration of rigor-shortened sarcomeres. These results were published in 1967 [1], and were, thereafter proved by many workers to be closely related to meat tenderization. I report in this paper the essential molecular mechanisms of these phenomena, and of structural changes in connectin or titin filaments. All of them are non-enzymatically induced by 0.1 mM calcium ion, which is the ultimate concentration of sarcoplasmic calcium ion in post mortem muscles.
Calcium↗
The quantitative alteration of the DNA content in strangulation marks is an artefact.
UNLABELLED: It is frequently difficult to prove the vitality in cases of fatal hanging. Using impulse cytophotometry, Müller et al. (Krim. Forens. Wiss. 44, 1981) reported on possibly vital alterations of the DNA content in five strangulation marks (hypodiploidy). The objective of the present study was to perform a re-evaluation by means of current methods of quantitative DNA analysis. The investigation included 24 cases of hanging (typical, n = 11; atypical, n = 13). DNA was extracted by use of phenol/chloroform and quantitated photometrically in relation to the tissue weight. In addition, skin specimens were examined histologically and their water content was determined. The mean DNA content of strangulation marks was 3.2 micrograms DNA/mg tissue, that one of uninjured skin (control) 1.4 microgram DNA/mg tissue. The ratio of DNA content between strangulation grooves and control skin varied from 1.2 to 5.2 (average: 2.4) implicating apparently elevated DNA levels in strangulation marks. Histology revealed typical changes with absence of leukocyte infiltration suggesting mechanical compression of DNA containing layers. The additional determination of the water content emerged-in dependence on the macroscopic appearance, dried or non-dried-reduced values for strangulation marks (average: 42% vs. 66%). Statistical analysis demonstrated a significant correlation between elevated DNA content and reduced water content of strangulation marks. CONCLUSION: the markedly elevated DNA content of strangulation marks is interpreted as an artefact due to drying of the skin with a reduction of the water content (and weight) in the course of mechanical cutaneous alterations (compression). Therefore, quantitative changes in the local DNA content of the groove have no importance as a sign of vitality in fatal strangulations.
Artifacts↗
gamma-aminobutyric acid in the murine brain: mass fragmentographic assay method and post-mortem changes.
An improved mass fragmentographic assay method for the determination of gamma-aminobutyric acid (GABA) in the brain is described. Applicability of the method was examined in a study of the effect of semicarbazide on GABA levels and in a separate study to confirm post-mortem increase in GABA. The method itself is based on Cattabeni's procedure in which GABA is assayed as trimethylsilyl derivative. Three improvements were made: a) application of a more suitable mass spectrometry system for GABA determination; b) use of 6-aminocaproic acid as the internal standard; c) selection f a high intensive ion (m/z 174) for mass fragmentographic analysis. The mass spectrometer used is accurate to as little as 25 pg. GABA levels after semicarbazide treatment decreased 54.4% in rat whole brain and 44.2% in the dorsal hippocampus. Rapid post-mortem increases in GABA levels were confirmed by application of the improved assay method; decreases were most clearly observable following microwave irradiation. Post-mortem changes in GABA were observed within 3 min after death, as reported by other researchers.
Amino Acids↗
[The dynamics of the early changes in the monoaminergic nervous apparatus of the spinal cord arteries in blunt trauma].
Changes in the adrenergic nervous system and population of tissue basophils of human spinal arteries in the course of 24 h after a blunt injury to the spine were studied. A staged pattern of development of compensatory adaptive reaction of the mechanisms regulating the spinal circulation has been revealed. The detected time course of posttraumatic changes may be interesting as it concerns the diagnosis of the time when a blunt injury to the spine was inflicted.
Adolescent↗
Endothelial changes in human donor corneas.
The corneal endothelium of intact donor eyes was evaluated by means of a specular microscope. In a series of 278 corneas, different morphologic changes were found in the endothelium. These changes are described and systematically classified. The findings are analogous to results obtained on experimental animals and with light- and electron-microscopic studies of other authors.
Cadaver↗
Amino acid transport by synaptosomes isolated from post mortem human brain.
Synaptosomes isolated from post mortem human brain release the transmitter amino acids upon depolarisation. Active preparations can be isolated for up to 24 hours post mortem. The amount of depolarisation-induced release of the transmitter amino acids is correlated with the rate of oxygen uptake. Only when this correlation is taken into consideration would it be possible to detect disease-related changes in presynaptic amino-acid transport systems.
Alanine↗
Respirator brain. Report of a survey and review of current concepts.
Because of renewed public and scientific interest in the concept of brain death and its diagnostic criteria, an opinion survey was undertaken, polling the membership of the American Association of Neuropathologists, regarding the definition, gross and microscopical features, and pathogenesis of the syndrome popularly designated the "respirator brain." Of the 191 respondents who completed the questionnaire, 174 (91%) indicated that the term respirator brain is properly used to describe a specific pathological entity, and 160 (84%) considered the characteristics of respirator brain to be distinct from those of late fixation. Of the 174 respondents who accepted the designation, 148 (85%) regarded a history of respiratory dependency as essential, and a vast majority (95%) agreed that extensive tissue necrosis occurs with little inflammatory cell reaction; other criteria were more controversial. Microscopical changes that suggest a pathogenetic mechanism attracted a number of informative, limiting, or qualifying remarks. Nonetheless, 54% thought that impaired cerebral blood flow contributed to pathogenesis.
Brain↗
[Forensic medical examination of abrasions in the study of mummified tissues in experiment].
Morphological and biophysical characteristics of abrasions and intact skin were studied during the process of their mummification at temperatures from 40 to 70 degrees C. The time after which the injuries become undetectable because color of the skin and injuries coincides, was determined. Changes in configuration and area of abrasions while drying are described. The rate of mummification and duration of the latter were established by dielectric indices of abrasions and skin at 10 cm wave length.
Forensic Pathology↗
Acute trazodone and quipazine treatment attenuates apomorphine-induced aggressive behaviour in male rats without major impact on emotional behaviour or monoamine content post mortem.
We have studied the effect of acute trazodone (3--20 mg kg(-1)) and quipazine (1--3 mg kg(-1)) treatment on the apomorphine-induced (1 mg kg(-1), once daily over 2 weeks) aggressive behaviour in male Wistar rats. All doses of trazodone and quipazine tested attenuated the aggressiveness as evidenced by the abolished intensity of aggressive behaviour and increased time of latency before the first attack. The acute trazodone (3--10 mg kg(-1)) or quipazine (1--3 mg kg(-1)) treatment had no or only a minor effect on rat behaviour in the elevated plus-maze, open field, and forced swimming test. Concomitant apomorphine (1 mg kg(-1)) plus trazodone (3 mg kg(-1)), but not apomorphine (1 mg kg(-1)) plus quipazine (1 mg kg(-1)), treatment slowed the development of aggressive behaviour. Repeated apomorphine treatment moderately reduced the dopamine post mortem and increased the DOPAC and HVA contents in striatum. Other monoamines or their metabolites were unchanged. Neither trazodone and quipazine treatment nor forced swimming stress induced any changes in the monoamine contents. In conclusion, our results indicate that acute trazodone and quipazine treatment attenuates the apomorphine-induced aggressive behaviour in male rats, but this phenomenon cannot be implicated in the changes in emotional and motivational behaviour, or in changes of monoamine content post mortem.
Aggression↗
The effect of sacrifice on image signal, T1, T2, and T*2 in liver, kidney, and brain of the Wistar rat.
Signal intensity in SE240/25 and GE240/25 images, T*2, T2, and T1 were measured prior to and after sacrifice at 1.5 T in liver, kidney, and brain of Wistar rats. Presacrifice, animals were maintained on 2-3% halothane, ensuring a high saturation of venous haemoglobin with oxygen, which emphasised blood oxygenation level dependent (BOLD) effects upon deoxygenation of haemoglobin postsacrifice. T*2 values (in ms) changed on sacrifice from 27.8 +/- 4.1 to 15.0 +/- 1.1 in liver (p << .001), from 57.4 +/- 6.5 to 52.8 +/- 5.7 in brain (p < .02), and from 52.3 +/- 10.3 to 37.6 +/- 11.9 in kidney cortex (p < .01). T*2 was also reduced in kidney medulla and papilla. T2 reduced on sacrifice (by a lesser amount than T*2), except in brain, which showed a small increase. T1 (ms) changed only in liver, showing a significant increase from 670 +/- 31 to 834 +/- 69 (p << .001). The ratio of signal postsacrifice to presacrifice was lowest in the SE240/25 and GE240/25 images of liver (0.73 +/- 0.03 and 0.52 +/- 0.05, respectively), but increased T1 may account for some of these changes. Expected signal ratios at sacrifice calculated from measured relaxation times agreed well with those observed experimentally. Relaxation changes observed on sacrifice were consistent with deoxygenation of haemoglobin. These results give an estimate of the maximum effects which changes of blood oxygen level might produce at 1.5 T and suggest that contrast due to variation of endogenous deoxyhaemoglobin may be exploitable in the liver.
Animals↗
Stability of pro-opiocortin-related peptides in post-mortem mouse brain tissue.
The stability of pro-opiocortin-related peptides, growth hormone and somatostatin was investigated in mouse brain for up to 72 h post mortem. The peptide content in acid extracts of whole mouse brain was measured by radioimmunoassay and the molecular forms characterised by chromatography on Sephadex G-50 under acid-dissociating conditions. The brain content of the pro-opiocortin-related peptides and growth hormone rose markedly with time after death and chromatography showed this to be due to an increase in the same molecular forms present immediately post mortem, with no significant peptide fragmentation or precursor cleavage. These rises were not seen in the brains of those animals hypophysectomized at death. In contrast, the levels of somatostatin were not significantly altered post mortem though there was a shift in the relative distribution of immunoactivity between the different molecular forms. These results indicate that the peptide content of post-mortem mouse brain may be affected by leakage of pituitary contents and that even though the levels of other neuropeptides may not change, their molecular forms may be altered.
Adrenocorticotropic Hormone↗
[Role of the structural changes of lungs in thanatogenesis of cranio-cerebral complicated trauma].
The lungs of 27 persons, who died of severe craniocerebral and combined trauma, were histologically examined. A deformation of the bronchi is registered in 15-60 min after craniocerebral trauma; desquamated epithelium and mucinous contents are found in their lumens. Erythrocytes and macrophages are detected in the alveolar lumens. The capillary alveolar septums are full-blooded; the alveolar septums are edematous with signs of hemorrhages and clusters of lymphoid cells. The venules are enlarged and full-blooded. Regions of the emphysema alternate with dystelectases and atelectases. The interstitial edema set on and the alveolar edema aggravates in 2-8 hours after trauma. There is an aggregation of erythrocytes. The leukocytic infiltration worsens. Hyaline membranes take shape. Similar changes are observed in the lungs in case of combined trauma; at the same time, the morphological changes are faster in the latter trauma variation. The detected structural impairments are typical of an acute pulmonary lesion and are crucial in thanatogenesis in craniocerebral and combined trauma.
Adult↗
Early post-mortem change of the crista ampullaris. A light and electron microscopic study of the Guinea-pig.
Post-mortem change (autolysis) of the sensory and the secretory epithelia was studied by means of the light and the electron microscope. The first ultrastructurally recognizable sign of autolysis occurred 10-15 min after death in the mitochondria of the hair cells and their adjacent nerve endings. The morphology of hair cells was occasionally well preserved 30 min post-mortem, but after 90 min or more autolytic changes were invariably severe. The secretory epithelium, however, was considerably less affected by autolysis than the hair cells during the first 5 h after death.
Animals↗
Changes in the release of amino acid neurotransmitters in the brains of calves and sheep after head-only electrical stunning and throat cutting.
In calves aged two to five months, throat cutting resulted in an increase in the concentration of the amino acid neurotransmitters glutamate and aspartate in the brain. Electrical head-only stunning by itself also increased the concentrations of these two neurotransmitters. The levels induced by stunning resulted in a seizure state characterised by epileptiform-like activity in the electroencephalograph. Combing head-only stunning with throat cutting within 10 seconds of the stun had a synergistic effect upon glutamate and aspartate, increasing their concentration by a greater amount and more quickly than either procedure on its own. An irreversible loss of brain function also occurred more quickly than after throat cutting alone. The administration of glutamate and aspartate receptor antagonists before the throat cutting lengthened the time to the loss of brain function in a dose dependent manner. Similar changes were observed in sheep but they occurred much more quickly than in cattle.
Abattoirs↗
Post mortem changes in Ca2+ transporting proteins of sarcoplasmic reticulum in dependence on malignant hyperthermia status in pigs.
Meat quality of pigs is dependent on biochemical and biophysical processes in the time course post mortem (p.m.) and is associated with the intracellular Ca2+ homeostasis. However, there is little known about changes in the Ca2+ transporting proteins controlling the Ca2+ uptake of sarcoplasmic reticulum (SR) in the time course p.m. In this study changes in the Ca2+ transporting proteins were investigated in homogenates of longissimus muscles of 4 malignant hyperthermia susceptible (MHS) and 6 malignant hyperthermia resistant (MHR) Pietrain pigs. Muscle samples were obtained at different time intervals: biopsy 2 h prior slaughtering and from the carcass immediately after exsanguination (0 h), 45 min, 4 h, and 22 h p.m. The SR Ca2+ uptake rate was measured immediately after homogenization with closed calcium release channel (CRC), with opened CRC and without manipulation of CRC. Additionally the SR Ca2+ ATPase activity was determined. The results show: (i) The ability of SR to sequester Ca2+ declined to about 60% in the first 45 min p.m. in MHS samples irrespective of CRC state, whereas in MHR samples this decline was about 5%; (ii) Ca2+ uptake and Ca2+ ATPase activity were not different between the biopsy and 0 h samples, i.e. the stress of slaughter was of no immediate influence; (iii) The Ca2+ ATPase activity of the SR declined at about the same rate as the Ca2+ uptake in both MHS and MHR pig samples in the course of time p.m.; (iv) In samples, taken immediately after exsanguination, the Ca2+ ATPase activity of MHS pigs was higher than that of MHR pigs. However, in samples taken 4 h p.m. Ca2+ ATPase activity of MHS pigs has declined to about 30% of the value at 0 h; (v) The CRC can be closed and opened in all samples up to 22 h p.m. and seems to be fully functional at all sampling times; (vi) The CRC of MHS pigs is almost fully open, whereas the CRC of MHR pigs is only partially open at all sampling times; (vii) The permeability of the SR membrane to Ca2+ (determined as the ratio of SR Ca2+ ATPase with and without ionophore A23187) is the same in both MHS and MHR and did not change with ongoing time; (viii) No uncoupling of uptake from ATP hydrolysis occurred up to 4 h p.m., but the coupling differed between MHS and MHR for all time intervals with lower values for MHS pigs. The results suggest that the decreasing Ca2+ uptake rate of homogenates, sampled at different times p.m., is essentially caused by changes in the Ca2+ pump and not by changes in the CRC or an increased phospholipid membrane permeability to Ca2+.
Animals↗
Qualitative and quantitative studies on human myelin basic protein in situ with respect to time interval between death and autopsy.
Normal human frontal lobe white matter obtained at autopsy was used to determine the extent of in situ post-mortem degradation of myelin basic protein (BP). Effects of the following two factors were studied: 1) time interval between death and autopsy, and 2) freezing and thawing the tissue. Quantitative extraction of BP from the autopsy material showed only minimal loss of BP that could be attributed to the time interval between death and autopsy (up to 48 h). The purified BP from these samples was electrophoresed on acrylamide gels at pH 4.3 and it was found that the electrophoretic patterns were comparable to zero hour bovine BP samples. The BP obtained from the autopsy samples was found to be encephalitogenic in guinea pigs. When tested against rabbit anti-human-BP serum, the purified BP preparations gave a single arc in immunoprecipitin test. BP extracted and purified from tissue that was frozen once and processed before it could thaw showed yields, encephalitogenic activity and acrylamide disc gel electrophoretic patterns that were similar to those of BP from tissue that was never frozen. However, frozen tissue that was thawed and then incubated for 8 h at room temperature before processing yielded only 13-25% of the total extractable protein. This BP also was encephalitogenic and showed acrylamide banding pattern that was similar to BP from tissue that was never frozen. Samples of white matter were examined by electron microscope. Unfrozen autopsy material showed some separation of myelin lamellae. Myelin in sections of frozen and thawed white matter showed separation as well as disruption of the lamellae. Samples that were frozen, thawed and then incubated at room temperature for 8 h showed sporadic loss of dense line material in addition to lamellar separation and disruption. The results a) show that BP is quite resistant to autolytic changes and b) are consistent with the location of BP along the cytoplasmic surface of the myelin membrane.
Aged↗