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PubMed1996

Investigations on the mechanism of adipocere formation and its relation to other biochemical reactions.

In the adipocere, which is one of the postmortem changes, some specific fatty acids possessing higher melting points, together with soap, play an important role in the formation of adipocere. These fatty acids were shown to be mainly 10-hydroxystearic and 10-hydroxypalmitic acids. Moreover, slight amounts of 10-oxostearic and 10-oxopalmitic acids, which have higher melting points than those of hydroxy fatty acids, exist in the adipocere as well. The substantial adipocere is formed and stabilized by these specific fatty acids together with the soap. The hydroxy fatty acid (OHFA) and oxo fatty acid (OXOFA) are biosynthesized by some bacterial enzymes. Various aerobic and anaerobic bacteria are involved in the formation of adipocere. For example, microbial conversion of various unsaturated fatty acids to 10-OHFA by Micrococcus luteus was investigated. It turned out that 10-OHFA was synthesized only from fatty acids possessing cis-9-unsaturation. It was also shown that 10-OHFAs were converted to the corresponding 10-OXOFAs but the 10-OXO compounds were inactive as substrates. Furthermore, it was found that the enzyme preparations from Flavobacterium meningosepticum solubilized by sonication catalyzed not only hydration of oleic acid to produce 10-hydroxystearic acid, but also dehydrogenation of this product in the presence of deuterium. On the other hand, we found out that there was 10-hydroxy-12-octadecenoic acid (10-OHODA) from linoleic acid in some kinds of adipocere. Recently, 10-epoxy-12-octadecenoic acid (leukotoxin, LTx), which is one of the lipid peroxides, was found not only in rice plants but in polymorphonuclear leukocytes. Since LTx was found in leukocytes related to inflammatory response, interest has been focused on its involvement, not only in the basic mechanism of biological defense, but also on the mechanism of shock as a vasoactive substance. A postmortem change itself is only remotely associated with a phenomenon in a living body. However, 10-OHODA found in adipocere seemed to exist also in polymorphonuclear leukocytes, suggesting that this compound might be closely related to a biological reaction.

Adipose Tissue↗
PubMed1981

Ontogeny of gamma-hydroxybutyric acid. I. Regional concentration in developing rat, monkey and human brain.

Steady state levels of gamma-hydroxybutyrate (GHB) were measured in whole brain and discrete regions of brain in developing and adult rat, monkey, and human brain. Postmortem changes in concentration of GHB in rat and human brain were also assessed. There were no significant postmortem changes in GHB under the conditions which the ontogeny experiments were done. The concentration of GHB was uniformly higher in the immature brains of the 3 species studied. In the rat the highest concentration was in immature hypothalamus and cortex with a significant decrease occurring between postnatal day 12 and 14. In human, the highest concentration was in fetal cerebellum and adult hypothalamus. Comparison of these data with published ontogeny data for gamma-aminobutyric acid (GABA) suggest that there may be a source of GHB in brain other than GABA.

Adolescent↗
PubMed2002

Environmental, biological, and methodological factors affecting cholinesterase activity in walleye (Stizostedion vitreum).

Organophosphorus (OP) insecticides have high acute toxicity toward many nontarget vertebrate and invertebrate organisms, but direct measurement of OPs in environmental samples is difficult because their concentrations may fall below detection limits within hours to days after entering aquatic ecosystems. Because OPs exert toxicity through cholinesterase (ChE) inhibition, which may persist for up to several weeks, ChE inhibition has been widely used in aquatic ecosystems as a biomarker for OP exposure in aquatic organisms. However, the biological, environmental, and methodological factors affecting ChE activity have not been well documented and must be considered and understood before ChE activity can be used as a dependable indicator of OP exposure to aquatic organisms. This study examined the influence of water temperature, size of larval and juvenile walleye (Stizostedion vitreum), stress, long-term storage, postmortem changes, and methods of euthanasia on ChE activity. Water temperature (17.2, 20.9, and 24.6 degrees C), stress, long-term storage (up to 180 days), postmortem changes, and method of euthanasia had no effect on ChE activity of walleye. There was a strong positive correlation (r = 0.87) between whole body ChE activity and total length (7.2-17.9 mm) for larval walleye, but a negative correlation between brain ChE activity and total length (59-164 mm) for juvenile walleye (r = 0.75). Because size, age, and development may affect ChE activity, fish of similar size should be used when evaluating the effects of ChE inhibitors. If fish of similar size are not available, it is recommended that relations between size, age, and development be understood so estimates of variation in ChE activity can be made.

Animals↗
PubMed1997

Architecture of human corneal nerves.

PURPOSE: The corneal innervation, mainly analyzed in light microscopical studies, has been described as radially oriented stromal nerve bundles that ramify as leashes in the subbasal plexus. The current study aims to determine the orientation, the size, and the postmortem changes of the nerve fibers in the subbasal plexus of the human cornea. METHODS: Before processing for light and electron microscopy, the position of the corneas within the enucleated eyes of persons with melanoma and pairs of postmortem eyes was marked. The orientation and postmortem changes of the fibers were studied in serial "en face" semithin sections, and the size was determined in random, ultrathin cross-sections. RESULTS: Thirteen and a half hours after death, the majority of the nerve fibers were degenerated or gone. Nerve fiber bundles in the subbasal plexus run first in the 9-3 hours direction, then after bifurcation in the 12-3 hours direction and after a second bifurcation again in the 9-3 hours direction. From the main straight bundles, single-beaded fibers branch and run obliquely. Quantification of the nerve fibers shows an equally dense innervated central and central-peripheral cornea (mean fiber diameter, 0.4 micron) and a five to six times lower innervated peripheral cornea (mean fiber diameter, 0.67 micron). CONCLUSIONS: The nerve bundles in the subbasal plexus of the human cornea form a regular dense meshwork with equal density over a large central and central-peripheral area. Because of their size, the majority of the fibers can be classified as C-fibers.

Aged↗
PubMed1998

Protection of goats against experimental enterotoxaemia by vaccination with Clostridium perfringens type D epsilon toxoid.

Enterotoxaemia in goats is mainly characterized by enterocolitis, and it has been suggested that the poor efficacy of commercial vaccines in preventing the disease is due to the local action of Clostridium perfringens toxin/s within the intestine, where circulating antibodies might not exert their action. Five goat kids were vaccinated with an incomplete Freund's adjuvant C perfringens type D epsilon toxoid vaccine on three occasions at three-week intervals, four similar kids were vaccinated with a commercial enterotoxaemia vaccine at the same times, and five other unvaccinated kids were used as controls. All the animals were challenged intraduodenally, one week after the last vaccination, with C perfringens type D filtered culture supernatant. At the time of challenge, the level of epsilon toxin antibodies in the serum of the Freund's adjuvant-vaccinated kids ranged between 2.45 and 230 iu/ml, while the kids that received the commercial vaccine had levels between 0.22 and 1.52 iu/ml. No clinical or postmortem changes were observed in the kids that received the Freund's adjuvant-vaccine. Three of the four kids that received the commercial vaccine developed mild, pasty diarrhoea, with a slight reddening of the colonic mucosa being observed postmortem. All the unvaccinated kids developed severe diarrhoea, respiratory distress and central nervous system signs, and were killed humanely between six and 24 hours after challenge. The postmortem changes consisted of pseudomembranous colitis, lung oedema and perivascular oedema of the brain. Moderate to high serum levels of anti-epsilon antibody appeared to protect the goats against both the systemic and the intestinal effects of C perfringens type D toxins.

Animals↗
PubMed1985

Relative postmortem stability of spinal motoneuronal proteins detectable by two-dimensional electrophoresis.

The suitability of using spinal tissue several hours after death for analysis by high resolution two-dimensional electrophoresis has been examined. It was found that many of the proteins of bovine spinal motoneurons detectable on two-dimensional polyacrylamide gels appear to be relatively stable in situ at room temperature during the first postmortem day. When extracts of total proteins from ventral roots and motoneuronal cell bodies isolated from 1-d-old tissue were examined, all spots could be matched to control gels. Upon visual inspection of the gels, postmortem changes in the amount of stain associated with a spot were obvious in three of 364 proteins from isolated motoneuronal cell bodies and none of 237 proteins from ventral roots. Other proteins underwent quantitative changes that were detected only after computer-assisted densitometry on the gels, whereas some did not appear to change at all. In the neuropil surrounding the motoneuron cell bodies, more pronounced changes in protein patterns occurred during the postmortem period. We conclude that properly controlled two-dimensional electrophoretic analyses of postmortem spinal tissue can provide reliable qualitative and quantitative information about the antemortem protein composition of spinal motoneurons.

Animals↗
PubMed2006

Pathological features in dead on arrival broilers with special reference to heart disorders.

A gross postmortem investigation was done on 302 broilers that died between catching and slaughter to establish predisposing factors for dying in this period. Special attention was paid to heart disorders, which were established by determining the ratio of the right ventricle mass to the total ventricle mass (RV:TV) and to postmortem changes in hearts and lungs of broilers that were dead on arrival (DOA). Macroscopic pathologic lesions were found in 89.4% of DOA broilers. Signs of infectious diseases appeared to be most frequent (64.9%), followed by heart and circulation disorders (42.4%), and trauma (29.5%). The RV:TV was significantly higher for DOA broilers in comparison with slaughtered broilers. The prevalence of hearts with an abnormal RV:TV in DOA broilers was 34.4 vs. 4.1% in slaughtered broilers. The DOA broilers with an abnormal heart ratio more frequently showed ascites and hydropericardium. Postmortem changes in lungs depend on the position of the carcass the first several hours after death. Broilers, which remain in dorsal recumbency for several hours after death, develop engorged lungs. A good health status as well as more attention for the catching and crating process is crucial in decreasing the percentage of DOA broilers. Prevention of an increased heart ratio and of ascites will improve the livability in the broiler house and also decrease the DOA rate enormously.

Abattoirs↗
PubMed1992

Alpha-[3H]amino-3-hydroxy-5-methylisoxazole-4-propionic acid binding to human cerebral cortical membranes: minimal changes in postmortem brains of chronic schizophrenics.

The binding of alpha-[3H]amino-3-hydroxy-5-methylisoxazole-4-propionic acid ([3H]AMPA), a selective ligand for the ion channel-linked quisqualate receptor, was evaluated in Triton X-100-treated membranes of human cerebral cortex. The presence of chaotropic ions produced divergent effects on specific [3H]AMPA binding: A twofold increase in the binding was observed with thiocyanide at 100 mM, although iodide (100 mM) and perchlorate (100 mM) reduced the binding. Chemical modifications of the sulfhydryl group with p-chloromercuriphenylsulfonic acid (PCMBS) produced threefold increases in specific [3H]-AMPA binding in the absence of KSCN as well as in the presence of KSCN. Treatment with dithiothreitol restored the enhanced specific [3H]AMPA binding by PCMBS to the basal level. Although specific [3H]AMPA binding in the absence of KSCN showed a single site (KD = 220 nM, Bmax = 235 fmol/mg of protein), curvilinear Scatchard plots of specific [3H]AMPA binding in the presence of 100 mM KSCN can be resolved into two binding sites with the following parameters: KD1 = 5.82 nM, Bmax1 = 247 fmol/mg of protein; KD2 = 214 nM, Bmax2 = 424 fmol/mg of protein. Quisqualate and AMPA were the most potent inhibitors of the [3H]AMPA binding in the presence of KSCN. Potent inhibitors of the binding included beta-N-oxalylamino-L-alanine (L-BOAA), cysteine-S-sulfate, L-glutamate, 6-cyano-7-nitroquinoxaline-2,3-dione, and 6,7-dinitroquinoxaline-2,3-dione. Kainate, L-homocysteine sulfinic acid, and L-homocysteic acid were active with an IC50 value of a micromolar concentration, whereas L-cysteic acid and L-cysteine sulfinic acid were weakly active.(ABSTRACT TRUNCATED AT 250 WORDS)

4-Chloromercuribenzenesulfonate↗
PubMed1985

Comparative radiological and morphological study of human pancreas. Pancreatitis like changes in postmortem ductograms and their morphological pattern. Possible implication for ERCP.

A postmortem study by ductography and histology was performed on 69 human pancreata with no clinical or histological signs of chronic pancreatitis. The ductograms, supplemented by five postmortem ductograms of chronic pancreatitis, were independently evaluated by six clinicians, skilled in ERCP; the degree of alteration was estimated by simple rating, forced choice rating, and by determination of the grade of chronic pancreatitis, Histologically, the amount of intraductal epithelial proliferation, periductal, intralobular and perilobular fibrosis, intraductal protein plugs, and fat necrosis was determined by semiquantitative methods. The six ductographical evaluations significantly differed in the level of their data, but corresponded in the range of distribution. All evaluations were correct regarding judgement of ductograms from patients with chronic pancreatitis. Ductograms of patients without chronic pancreatitis, however, were also frequently classified as chronic pancreatitis; overall 81% (minimal 37%, moderate 33%, severe 11%). This high level of false positive diagnosis indicates the frequency of pancreatitis like lesions in the main duct and its side branches in patients without chronic pancreatitis. Ductal lesions were significantly correlated with perilobular fibrosis. This finding favours the assumption, that in the non-inflamed pancreas, perilobular fibrosis plays a key-role in the development of ductal alterations, as in chronic pancreatitis. Perilobular fibrosis may result from intralobular inflammation caused by age-dependent intraductal epithelial hyperplasia.

Adult↗
PubMed2005

Effect of hypothermia on postmortem alterations in MAP2 immunostaining in the human hippocampus.

Ischemic neuronal injury induce degradation of microtubule-associated protein 2 (MAP2). In addition to ischemia, postmortem brains show alterations in MAP2 immunoreactivity in the hippocampus, suggesting that the factors inducing cytoskeletal disruption in postmortem brain are similar to those in ischemic brains. Hypothermia reduces the severity of ischemic injury including disruption of MAP2 in the hippocampus. However, whether hypothermia reduces postmortem changes of MAP2 was not clear. In this study, we evaluated the effect of hypothermia on postmortem degradation of MAP2 in the human hippocampus at various postmortem intervals using immunohistochemistry. In postmortem brains without hypothermia (the normothermic group), the locus of MAP2 immunoreactivity moved from the dendrites to the cell bodies prior to becoming undetectable with increasing postmortem interval, particularly in the CA1-subiculum region. On the other hand, the change in MAP2 immunoreactivity was remarkably attenuated in brains of death from cold (the hypothermic group). The present study demonstrated that MAP2 disruption is remarkable in the CA1-subiculum region of autopsied brains and that hypothermia reduces the postmortem change of MAP2, as observed in ischemic brain. Therefore, immunostaining of MAP2 in the hippocampus could be used to diagnose hypothermia.

Adolescent↗
PubMed2005

Effect of hypothermia on postmortem alterations in MAP2 immunostaining in the human hippocampus.

Ischemic neuronal injury induce degradation of microtubule-associated protein 2 (MAP2). In addition to ischemia, postmortem brains show alterations in MAP2 immunoreactivity in the hippocampus, suggesting that the factors inducing cytoskeletal disruption in postmortem brain are similar to those in ischemic brains. Hypothermia reduces the severity of ischemic injury including disruption of MAP2 in the hippocampus. However, whether hypothermia reduces postmortem changes of MAP2 was not clear. In this study, we evaluated the effect of hypothermia on postmortem degradation of MAP2 in the human hippocampus at various postmortem intervals using immunohistochemistry. In postmortem brains without hypothermia (the normothermic group), the locus of MAP2 immunoreactivity moved from the dendrites to the cell bodies prior to becoming undetectable with increasing postmortem interval, particularly in the CA1-subiculum region. On the other hand, the change in MAP2 immunoreactivity was remarkably attenuated in brains of death from cold (the hypothermic group). The present study demonstrated that MAP2 disruption is remarkable in the CA1-subiculum region of autopsied brains and that hypothermia reduces the postmortem change of MAP2, as observed in ischemic brain. Therefore, immunostaining of MAP2 in the hippocampus could be used to diagnose hypothermia.

Adolescent↗
PubMed2004

Indicators of tenderization are detectable by 12 h postmortem in ovine longissimus.

Postmortem changes in osmotic pressure; ionic strength; pH; temperature; mu- and m-calpain; calpastatin; desmin degradation; and myofibril fragmentation index (MFI) were determined in ovine longissimus muscle. Our objectives were to characterize changes in these variables and to identify postmortem time points at which significant proteolysis and tenderization (as measured by change in MFI) could be detected. Seven crossbred (Dorset x Romanov) lambs were slaughtered, and samples of the longissimus muscle were removed at 0, 3, 6, 9, 12, 24, 72, and 360 h postmortem. Osmotic pressure increased (P < 0.05) from 379 to 528 mOsm during the postmortem storage period, with two-thirds of the increase occurring within the first 24 h. By measuring conductivity, we showed that ionic strength increased (P < 0.05) from 8.13 to 9.78 mS/cm during the storage period, which is equivalent to 79 and 97 mM NaCl solutions, respectively. In accordance with pH and temperature, conductivity reached ultimate levels at 24 h postmortem. Within 9 h postmortem, mu-calpain activity had decreased (P < 0.05) from at-death values and continued to decrease until 72 h, at which time it was undetectable. It was still possible to detect the 76-kDa isoforms (a product of the autolysis of the 80-kDa subunit of mu-calpain) immunologically, which implies that the loss of activity was not caused by extensive autolysis. In contrast, m-calpain activity remained constant throughout the aging period, whereas calpastatin activity was stable until 24 h postmortem, after which it gradually decreased. Autolysis products of mu-calpain were detected at 3 h postmortem, indicating that mu-calpain was activated some time between 0 and 3 h postmortem. Moreover, the effect of mu-calpain activity on myofibrillar substrates was first observed at 9 h postmortem, when a 23% loss of native desmin was detected. This degradation translated into an increase in MFI at 12 h. Collectively, these results imply that mu-calpain is active in postmortem muscle in the presence of calpastatin, and that effects of mu-calpain activity as determined by increased MFI are detectable during the first 12 h postmortem.

Animals↗
PubMed2005

Postmortem imaging of blood and its characteristics using MSCT and MRI.

The rapid development of computed tomography (CT) and magnetic resonance imaging (MRI) led to the introduction and establishment in postmortem investigations. The objectives of this preliminary study were to describe the imaging appearances of the early postmortem changes of blood after cessation of the circulation, such as sedimentation, postmortem clotting, and internal livores, and to give a few first suggestions on how to differentiate them from other forensic findings. In the Virtopsy project, 95 human corpses underwent postmortem imaging by CT and MRI prior to traditional autopsy and therefore 44 cases have been investigated in this study. Postmortem alterations as well as the forensic relevant findings of the blood, such as internal or subcutaneous bleedings, are presented on the basis of their imaging appearances in multislice CT and MRI.

Aorta↗
PubMed1991

In vitro loss of potassium from erythrocytes during the 0-108 h postmortem period in rats: relationship between potassium loss and postmortem interval.

A simple technique was employed for measurement of potassium loss (K(los)s) from normal and from postmortem rat erythrocytes during controlled exposure to physiologically isosmotic NaCl solution. Potassium loss from the cells decreased in a (non-linear) time-related manner during the 0-108 h postmortem period; expression of the data in the form of a double logarithmic plot (log K(loss) versus log postmortem interval (PMI) linearized the relationship between 18 and 108 h post mortem (r = -0.86; P less than 0.001 (n = 24)). Experimental data revealed that the observed postmortem changes in K(loss) were associated with and probably resulted from, the postmortem decrease in magnitude of the potassium concentration gradient across the erythrocyte membrane. Attention is drawn to the possibility of utilizing measurements of in vitro loss of potassium from erythrocytes as a means of estimating time elapsed since death.

Animals↗
PubMed2000

Morphologic preservation and variability of human donor retina.

PURPOSE: To facilitate studies of human retina and utilization of human retinal tissue for treatment of retinal diseases, we studied morphologic preservation in postmortem human retina. METHODS: Morphology of retinas from thirty-one human eyes was examined using light and electron microscopy. The inner and outer retina, rod and cone photoreceptor cells, and central and peripheral retina were compared with regard to morphologic preservation. Possible factors affecting survival were analyzed. RESULTS: The earliest postmortem change was vacuolation of the nerve fiber layer within a few hours postmortem, followed by vacuolation and cytoplasmic swelling of the inner retina. As compared with the inner retina, outer retinal structure was better preserved, i.e., the photoreceptor cells maintained better morphology. Rod cell morphology was better preserved than cone cell morphology, with good preservation of the rod outer segment disc membranes and the inner segment mitochondrial membranes. Thus, well-preserved rod photoreceptor cells were evident in specimens at least 48-hours postmortem. Peripheral retina was better preserved than the central retina including the fovea and perifovea. Factors affecting anatomical integrity included the total time postmortem and, more importantly, the time between death and enucleation. Other factors, including age and sex, did not appear to affect morphological preservation in the present study. CONCLUSIONS: Human retina postmortem remained morphologically intact for a relatively long period of time, with differential preservation among different geographic areas and cell types. This morphologic evidence is consistent with previous findings of functional preservation (e.g. , photoresponses) in such tissue. This study may shed some light on understanding of human retina and its utilization for retinal transplantation.

Adolescent↗