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PubMed2002

Effects of refrigeration on the biometry and development of Protophormia terraenovae (Robineau-Desvoidy) (Diptera: Calliphoridae) and its consequences in estimating post-mortem interval in forensic investigations.

The aim of this study was to simulate the low temperatures that insects could experience between the time being sampled from cadavers and their arrival in the laboratory. This was in order to investigate the effect of low temperature on development of maggots. At different stages of development, individuals of Protophormia terraenovae (Robineau-Desvoidy) reared at 24 degrees C were submitted to a temperature of 4.0+/-0.5 degrees C for a period varying from 1 to 10 days. Independent of the stage of development at which the insects were refrigerated, the treatment induced significant changes on the duration of development. The effect of low temperature on the developmental time between the return to 24 degrees C to adult emergence depended on the larval stage that was refrigerated. When first instar larvae and prepupae were refrigerated, the time to emergence at 24 degrees C decreased with an increase of duration of the refrigeration period. Time to emergence increased under the same conditions when second instar larvae and pupae were refrigerated. These results indicate that keeping larvae of P. terraenovae at 4 degrees C does not just simply lead to a cessation of metabolism but disturbs the regular development. Ten days of cooling induced an error in estimating post-mortem interval (PMI) of more than 6h.

Animals↗

PubMed1999

What happens in freezing bodies? Experimental study of histological tissue change caused by freezing injuries.

In order to evaluate histological features of freezing damages to human tissue after death, we froze samples of liver and heart tissue to temperatures of -12 degrees C, -28 degrees C and -80 degrees C, and stored them for 24 and 72 h, respectively, at those temperatures. After thawing and routine preparation for histology, the samples were evaluated both by microscope and with an electronic image analyzer. In all cases, we found extended extracellular spaces and shrunken cells resulting from the freeze-thaw cycle. These features were more pronounced in tissues stored for longer durations. Such findings seem to be typical of tissue that has been frozen prior to examination. Two cases of dead bodies found outdoors at subzero temperatures demonstrate that formerly frozen and unfrozen tissues can be distinguished histologically. The findings are examined in relation to the fundamental laws of cryobiology.

Adult↗

PubMed1986

Post-mortem stability of progesterone in rat brain.

Progesterone concentrations in the brains of female rats kept at +20 degrees C or +4 degrees C for 0 to 48 hours after death were investigated. After two hours at +20 degrees C the progesterone concentration in seven studied brain areas were equal to that in control brains (dissected immediately after death). After four hours at +20 degrees C, levels decreased significantly in three brain regions. Intact rats that were placed in a refrigerator (+4 degrees C) after four hours at room temperature (+20 degrees C) showed no further changes in brain progesterone concentration. In the control group, the cerebral cortex, the hypothalamus and the hippocampus contained progesterone levels significantly higher than in all other areas (p less than 0.05). After four hours at room temperature only the hypothalamus showed higher levels (p less than 0.05). In conclusion, time after death and storage temperature affect the post-mortem levels of progesterone. Because of their differences in body masses, the conditions in the rat brain are not comparable to those in the human brain. However, it might be possible to study the regional distribution of progesterone in the human brain if control cases matched with regard to post-mortal time and brain temperature are used.

Animals↗

PubMed2006

Insulin degrading enzyme activity selectively decreases in the hippocampal formation of cases at high risk to develop Alzheimer's disease.

In this study we report that the membrane-bound, but not cytosolic insulin degrading enzyme (IDE) protein concentration and IDE activity are significantly decreased in the hippocampal formation of cases affected by mild cognitive impairment (MCI) which are at high risk to develop Alzheimer's disease (AD), relative to normal neurological controls. Membrane-bound IDE protein concentrations and activity in the hippocampal formation continued to decrease during the conversion from MCI to mild-severe AD. This selective decrease in hippocampal membrane-bound, but not cytosolic, IDE concentration and activity was tissue specific since no changes in either membrane-bound or cytosolic IDE were found in the occipital cortex of the same cases examined. Most interestingly, the decreased hippocampal membrane-bound IDE protein activity negatively correlated with brain beta-amyloid (Abeta)X-42 content in MCI and in AD brain. The study tentatively suggests that interventions aimed at promoting membrane-bound IDE activities in the brain of MCI cases may help to prevent the onset and possibly the progression into AD through mechanisms involving the clearance of monomeric Abeta from the brain.

Aged↗

PubMed1993

Vitreous humour and cerebrospinal fluid hypoxanthine concentration as a marker of pre-mortem hypoxia in SIDS.

AIMS: To assess the rate at which premortem hypoxia occurs in sudden infant death syndrome (SIDS) when compared with death in early childhood. METHODS: The hypoxanthine concentration was measured as a marker of premortem hypoxia in vitreous humour and cerebrospinal fluid samples obtained at necropsy from 119 children whose ages ranged from 1 week to 2 years. RESULTS: Increasing interval between death and necropsy was accompanied by an increase in the hypoxanthine concentration of vitreous humour for the first 24 hours, at a rate of 8.3 mumol/l/hour. Thereafter, there was little change with time, and the results wer corrected to 24 hours according to a regression equation. Cerebrospinal fluid concentrations showed no significant change with time following death. Patients were divided into three groups according to the cause of death: SIDS, cardiac or pulmonary disease, and others. Median values for the cerebrospinal fluid hypoxanthine concentrations were not significantly different among the groups and no difference could be shown between the vitreous humour hypoxanthine concentration in cases of SIDS and those children dying from other causes. Patients with established cardiac or pulmonary disease had a significantly reduced vitreous humour hypoxanthine concentration which may have reflected the premortem use of artificial ventilation. CONCLUSIONS: The results of this study do not support the view that pre-mortem hypoxia is a common feature in SIDS when compared with other causes of death.

Biomarkers↗

PubMed1988

Cytokinetics of epidermic cells in skin from human cadavers. I. Dependency on the postmortal interval.

Punch biopsies taken from the extensor side of the thigh of 35 human cadavers were incubated in vitro with radioactively labeled thymidine (3H-thymidine = 3H-TdR, 14C-thymidine = 14C-TdR) to determine whether a relationship exists between changes in the proliferative activity of the skin and the postmortal interval after irreversible cardiac arrest. The cadavers were stored at 4 degrees C. Cadavers with indeterminable time of death or presence of intoxication, drug therapy with cytostatic agents, or a skin disease were excluded from the study. Single, double, or multiple biopsies were performed on the same cadaver; single labeling with 3H-TdR was done in all cases; double labeling with 3H-TdR and 14C-TdR in selected cases. No relevant changes in the labeling index (mean, 2.39 +/- 1.03%) were demonstrable within the examined postmortal interval of 77.75 h. The DNA synthesis time (ts) was, on the average, 4.75 +/- 1.44 h; a certain relationship to the postmortal interval existed since ts declined with increasing storage time. The potential doubling time (tpot) decreased accordingly, beginning with 181.7 h (mean storage time, 29.9 h) and ending with 137.7 h (mean storage time, 41.7 h). No statistically relevant differences, however, were established at the 1% level. Whereas both labeling index and tpot during the early postmortal interval are comparable with observations in live humans, ts was relatively short as compared to that for the epidermis of live humans.

Adolescent↗

PubMed1975

Relationship beteen activation of "detoxicating" enzymes in stored broken-cell preparations and in autolysing liver.

Activity of UDP-glucuronyltransferase (GT) towards o-aminophenol, p-nitrophenol and bilirubin has been followed in portions of mouse liver stored for periods up to 24 h and in mouse-liver homogenates stored under similar conditions of time and temperature. In both preparations and for all three substrates the pattern of change of GT activity was closely similar. Activity decreased initially, then rose to an optimum higher than in fresh tissue before finally falling. Overall glucuronidation, as measured in slices, also follwed this pattern. The effect of cycloheximide and of detergents, and the levels of UDP-glucose dehydrogenase, UDP-glucuronic acid and aniline hydroxylase were also studied. It is concluded that autolysing liver tissue passes through a period of increased GT activity and glucuronidation corresponding in onset with spontaneous activation of GT in stored homogenates and probably originating by a similiar mechanism. This increase contrasts with progressive fall in hydroxylating activity. The latency of GT in vivo and the value of its activation in damaged liver are discussed.

Aniline Hydroxylase↗

PubMed1981

[The kinetics of the postmortal bacterial metabolism of the glutamic acid in brain (author's transl)].

This paper gives a brief report on investigations on bacterial enzyme activities in putrefied brain tissue. The effects of temperature changes (5--30 degrees C) and pH-changes (3--8) on the rate of the glutamic acid reactions, especially proteolysis and alpha- resp. gamma-decarboxylation, were examined to reveal to which extent a temperature and pH-independence is valid for the previously developed time of death formula: (formula: see text). The present investigation demonstrates the independence of the mentioned formula for the important pH-range of 6--7.2 and for a temperature range of 17.5--25 degrees C (room temperature). A second important result is that in these ranges a high proteolytic activity is observed so that the continuation of the reaction sequences will be maintained. These results reveal that the postmortal metabolism of the glutamic acid may be suitable to determine the time of death.

Aminobutyrates↗

PubMed1980

[Experimental examinations on forensic determination of time of death by electrofocusing of soluble muscle protein (author's transl)].

Proteolytic changes in the muscles of cadaver are demonstrable by putrefaction experiment with the electrofocusing on polyacrylamide gels. These changes can--within a narrow limit--be used in the determination of time of death at a stage when the early signs of death are not suitable any more. A fraction with a pI-value of 7.2 appears as a proteolytic fission at 30 degrees C not earlier than the second day after death. This fraction can be detected at 20 degrees C from the fifth to the sixth day p.m. At 10 degrees C it will not be detectable until the ninth day p.m. At a pH-range between 6.9 and 7.7, at 30 degrees C and 8 days after death, or at 20 degrees C and 9 days after death, only a relatively stable fraction is detectable with a pI-value between 6.9 and 7.0.

Forensic Medicine↗

PubMed2002

Evidence for a role for apoptosis in central pontine myelinolysis.

We have performed an immunocytochemical study of autopsy material from five cases of central pontine myelinolysis (CPM) and five age and sex-matched control subjects with the aim of exploring the possible involvement of apoptotic mechanisms in oligodendrocytes in this condition. We searched for immunoreactivity of glial cells for the apoptotic-related markers death receptor (DR) 3, Bax and Bak, the anti-apoptotic marker Bcl-2 and the cell cycle marker Ki-67. The latter marker was studied because it is known that entry of cells into the cell division cycle can trigger apoptosis if it does not result in mitosis. In CPM there was marked up-regulation of expression of the myelination-related enzyme carbonic anhydrase isoenzyme II and also markedly increased expression of Ki-67 in nuclei of glial cells of all types but particularly those of cells morphologically resembling oligodendrocytes. Despite this, there was no clear increase in density of such cells in CPM. The pro-apoptotic markers Bax, Bak and DR3 were all modestly increased in glial cell cytoplasm in CPM, while there was no change in expression of Bcl-2, which was only sparsely detected in glial cells both in controls and cases of CPM. The ratio of pro- to anti-apoptotic factors would appear from this evidence to have altered in favour of apoptosis in glial cells, most of which had the appearance of oligodendrocytes and many of which expressed Ki-67. We interpret this preliminary study as favouring apoptosis as a mechanism of oligodendrocytic death in CPM. Further study of this mechanism in CPM may lead to identification of factors that could reduce or prevent this rare but serious and often fatal disease.

Aged↗

PubMed1985

Sequential and diagnostic features in primary biliary cirrhosis based on serial histologic study in 209 patients.

Four forms of piecemeal necrosis--biliary, lymphocytic, ductular, and fibrotic--were identified in 605 liver biopsy specimens from 209 patients with primary biliary cirrhosis. Whereas lymphocytic piecemeal necrosis, often associated with lobular hepatitis, was most common in stages 2 and 3 of the classical histologic staging, biliary piecemeal necrosis was frequent in all stages, except stage 1, and the fibrotic form appeared to be a late, mainly cirrhotic feature. In 77% of patients cholestatic features predominated, whereas hepatitic changes producing some histologic overlap with chronic active hepatitis occurred in the remaining patients. These patterns tended to be maintained throughout the course of the disease. Large hypocellular scars found in 36% and 59% of stage 3 and 4 specimens, respectively, appeared to be a characteristic feature of biliary disease. The prevalence of classical features was assessed. The analysis of sequential biopsy specimens from those patients who died showed that cirrhotic transformation, increasing cholestasis (in particular with prominent hyaline inclusions), abundance of coarse collagen bundles, and "halo" formation at the margins of the fibrous septa were associated with a poor prognosis. We were unable to show that the presence of granulomas is associated with a more favorable course of the disease.

Adult↗

PubMed2006

Decreased MT1 melatonin receptor expression in the suprachiasmatic nucleus in aging and Alzheimer's disease.

The pineal hormone melatonin is involved in the regulation of circadian rhythms and feeds back to the central biological clock, the hypothalamic suprachiasmatic nucleus (SCN) via melatonin receptors. Supplementary melatonin is considered to be a potential treatment for aging and Alzheimer's disease (AD)-related circadian disorders. Here we investigated by immunocytochemistry the alterations of the MT1 melatonin receptor, the neuropeptides vasopressin (AVP) and vasoactive intestinal peptide (VIP) in the SCN during aging and AD. We found that the number and density of AVP/VIP-expressing neurons in the SCN did not change, but the number and density of MT1-expressing neurons in the SCN were decreased in aged controls compared to young controls. Furthermore, both MT1-expressing neurons and AVP/VIP-expressing neurons were strongly diminished in the last neuropathological stages of AD (Braak stages V-VI), but not in the earliest stages (Braak stages I-II), compared to aged controls (Braak stage 0). Our study suggests that the MT1-mediated effects of melatonin on the SCN are disturbed during aging and even more so in late stage AD, which may contribute to the clinical circadian disorders and to the efficacy of therapeutic melatonin administration under these conditions.

Adult↗

PubMed1982

Dopamine metabolism increases in post-mortem schizophrenic basal ganglia.

The dopamine-rich regions of post-mortem brains from 6 schizophrenics and 7 controls were analyzed. There were no significant changes in dopamine concentrations in basal ganglia and nucleus accumbens of schizophrenics compared with controls. Schizophrenic basal ganglia (putamen and caudate) showed significantly higher levels of homovanillic acid, and tyrosine hydroxylase activity. Among the schizophrenic patients, markedly high activity of tyrosine hydroxylase was measured in a patient diagnosed as catatonic type. He had not taken antipsychotic drugs for 3 months prior to death. In his relatives, three other schizophrenics were found to the second degree. A remarkable low level of dopamine and a high level of homovanillic acid measured indicate this case would have had an increased turnover rate of dopamine in the dopaminergic nerve terminals. Among the schizophrenic patients, there might be one group whose enzyme activity of dopamine synthesis in the brain is exceptionally high.

Adult↗

PubMed1985

[Immunoenzyme demonstration of isoantigens A, B and H in kidney tissue changed by putrefaction].

In contrast to blood serology, which usually fails in specimens more than a few days old, immunohistochemistry (PAP technique) provided reliable information on the blood group (ABO) and, in most cases, also the secretor character of 23 kidney specimens stored for months at room temperature. Better results were obtained with monoclonal antibodies than with human sera. In the late stages of decomposition, blood group diagnosis is based on the more decomposition-resistant antigens of the collecting tubular epithelium (in secretors) and the endothelia of the arteriolae medullares rectae and not on the identification of erythrocytic antigens. In addition, a decomposition-resistant epithelial antigen in the distal convoluted tubules (Tc II) is unmasked by autolysis or heterolysis. "Blood group" antigens were frequently detected in bacteria and fungi. These antigens, however, were clearly distinguishable from blood group characters of the tissue. A transient, weak, false-positive reaction with monoclonal anti-B appeared in decomposed Tc II epithelia.

ABO Blood-Group System↗

PubMed1981

Post mortem changes in drug-metabolizing enzymes of rat liver and human liver.

The aim of this investigation was to obtain information on the time-dependent decrease of the drug-metabolizing system in autolysing rat liver, and also in human cadaver liver. Rat liver, divided into three parts, was tested immediately after removal and 6 and 12 hrs later. Parameters investigated were: microsomal protein, cytochrome P-450, NADPH cytochrome C reductase, glucose-6-phosphatase, aminopyrine-N-demethylation and aniline-p-hydroxylation. In human liver, samples taken from 0.5 up to 3.5 hrs after death, microsomal protein cytochrome P-450, NADPH cytochrome C reductase and phospholipids were tested. Nearly all parameters based on microsomal protein decrease during autolysis, but by different amounts. Interestingly, the cytochrome P-450 content of patients with signs of shock 12 hrs before death is significantly lower than in patients without shock.

Adult↗

PubMed1990

Amyloid in intervertebral discs of surgery and autopsy material. A new class of amyloid?

Intervertebral discs from 82 consecutive operations on herniation and 59 autopsies (one case with generalized amyloidosis) were studied. Amyloid deposits observed in surgical and autopsy specimens increased with age in both series. Degenerative changes were related to age and to amyloid deposits in autopsy, but not in surgical cases. Calcium pyrophosphate dihydrate deposits (often in proximity to amyloid deposits) were found in autopsy discs of six patients and in surgical specimens of three patients with previous operations on herniated discs. Antisera against amyloid fibril proteins of different types including AA-, A lambda-, A kappa, AF- and AB-types showed no reaction with disc amyloid. In one case with generalized A lambda-amyloidosis the disc amyloid was not of the A lambda-type. Based on our results, we suppose that disc amyloid is a form of localized senile amyloidosis - possibly representing a new class of amyloid limited to cartilage tissue.

Adult↗

PubMed2002

Time of submergence using aquatic invertebrate succession and decompositional changes.

Pig carcasses were placed in pond and stream habitats in the Malcolm Knapp Research Forest in Maple Ridge, B.C. for approximately one year, to examine the development, species, and sequence of invertebrates associated with the carrion. An invertebrate successional database was created for pond and stream habitats for potential use in estimating time of submergence in water related death investigations. Analysis has shown that a predictable succession of invertebrates colonize the carrion. However, whether or not this succession is carrion dependent or seasonal is unknown. There is a difference in the species composition between pond and stream habitats. Habitats influence invertebrate fauna, therefore, species colonizing carrion are habitat-specific. In both habitats, no one organism can determine time of submergence alone. Decompositional descriptions from this research were compared with 15 freshwater related death investigations. Similarities were seen in the earlier decompositional characteristics including bloat, discoloration, and nail shedding; however, the human descriptions were so vague that they had little value in determining time of submergence and hence time of death.

Animals↗

PubMed1985

The diagnostic value of glycated haemoglobin levels in post-mortem blood.

Glycated haemoglobin (HbA1) in post mortem blood was estimated following electrophoretic separation. HbA1 was measured in preserved and unpreserved specimens and its stability in vitro was studied. No significant change in the proportion of HbA1 was observed in samples stored for more than 40 days at 4 degrees C. Specimens were analysed for glucose and HbA1. There was poor correlation between these parameters, and no significant difference between the mean values of HbA1 in specimens collected within 24, 48 and 72 or more hours following death, from subjects with no previous history of diabetes. The levels were within the laboratory reference range, whilst eight specimens collected from diabetic subjects demonstrated elevated levels. There was no significant difference in HbA1 levels collected from different sites in the body even though the glucose levels showed some variation. The measurement and apparent stability of HbA1 post mortem may be a more useful diagnostic test than glucose alone where diabetes may be suspected.

Blood Glucose↗