PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Postmortem Changes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources
PubMed1996

Evaluation of intracellular diffusion in normal and globally-ischemic rat brain via 133Cs NMR.

The question of whether the apparent diffusion coefficient (ADC) of intracellular water changes after brain injury was addressed by using 133Cs as an indicator to report on the state of the intracellular environment. Cesium is an NMR-detectable potassium analog that accumulates in the intracellular space and is detectable in rat brain after being added to the animal's diet. The ADC of cesium was measured before and after the death of the rat. The cesium ADC fell from 0.91 +/- 0.05 x 10(-3) mm2/s (mean +/- SEM, n=5) in the alive rat to 0.71 +/- 0.05 x 10(-3) mm2/s within 20 min (the best time resolution of the experiment) of the death of the animal and stayed at this value for at least 3 h (p < 0.001). Assuming that the ADC of cesium reflects motion in the intracellular environment, these results support the idea that there are changes associated with cell injury that would cause a reduction in the ADC of intracellular water. Hence, one factor contributing to the decrease in water ADC after brain injury is a change in the ADC of intracellular water.

Animals↗
PubMed1980

The cholinergic system in old age and Alzheimer's disease.

Activities relating to the cholinergic system in post-mortem brain tissue have been examined in relation to ageing and Alzheimer-type pathology. As senile plaque numbers increased in non-demented and demented old people, activities of choline acetyltransferase and acetylcholinesterase decreased, butyrylcholinesterase increased and muscarinic receptor binding remained unchanged. The behaviour of these biochemical activities was further examined in relation to the ageing process in mentally normal people. Loss of choline acetyltransferase also occurred, to a lesser extent, with increasing age and muscarinic binding decreased but there was no age-related loss in acetylcholinesterase. These biochemical findings are discussed in relation to the possible involvement of the cholinergic system in 'normal' ageing and in Alzheimer's disease and are compatible with an extension of age-related nerve terminal changes to abnormalities of cholinergic processes in the disease itself.

Acetylcholine↗
PubMed1992

[Detection of ischemic myocardial damage].

Cases of cardiac death (myocardial infarction, coronary artery thrombosis, coronary artery sclerosis) were investigated with histochemical and immunohistochemical methods. Histochemical staining methods (HE, LFB, CAB) were used, with immunohistochemical methods were detected the proteins Desmin, Myoglobin, Fibrinogen and Complement C5b-9. Macroscopically visible myocardial infarctions were detected with both methods clearly. The damage pattern was associated to the type of destruction. At myocardial infarction the changes were focal at the other groups more disseminated.

Coronary Artery Disease↗
PubMed1996

The speed of post mortem change to the human skeleton and its taphonomic significance.

The aim of this study was to assess the potential speed of post mortem alteration to skeletal microstructure by examining human material drawn from differing environmental contexts and time periods. The material was taken from terrestrial, intertidal and lacustrine contexts and extended over a range of 3 months to 83 years post mortem. The examination was conducted using backscattered electron imaging which provided information on microstructure and relative density. The results from this study have significantly brought forward the time of known onset for post mortem alteration for 3 morphological types of microstructural change, the earliest of which was 3 months post mortem. The contribution of the depositing environment was also shown to influence significantly the microstructural/ morphological type of post mortem alteration. It is hypothesized that microstructural changes to bone could occur within days of death as a result of endogenous bacterial migration to the skeleton. Further studies are required to establish definitively the earliest moment that such change can occur prior to skeletonisation.

Adult↗
PubMedDate not supplied

[Physiopathologic changes in brain death. Their importance for management and organ donation decisions].

Technological advances in the medical area have allowed for development of useful techniques to treat patients with diverse diseases. For example, at intensive care units this technology allows maintenance blood flow and tissue oxygenation even when brain death (BD) is already established and the individual cannot function. The function of heart, lungs, and other organs can be maintained with different devices, but maintenance of cerebral functions is not not yet possible. Therefore, when a subject fulfills legal and medical requirements for BD, we must be clear that any patient procedure will not keep him alive, although the subject looks alive due to support devices; when BD is present, death must be accepted. Obviously, death is a difficult process to accept, including for health personnel. We consider that it is very important for medical and nursing personnel directly responsible for patient care to receive knowledge on BD and recognize the alternatives with regard this situation, to be able to provide specific orientation when it is required. This paper is a review of the BD concept, main physiopathologic changes, and some possible treatment alternatives to maintain the patient as a potential organ donor.

Brain Death↗
PubMed1977

Immunohistochemical localization of cyclic GMP in rat cerebellum.

The technique of cyclic nucleotide fluorescence immunohistochemistry has been applied for the specific localization of cyclic GMP in rat cerebellum. We report immunofluorescence associated with fibres and membranes, contrasting with previously reported cytoplasmic localization of cyclic AMP in different cell populations, using a similar technique. We have been unable to detect changes in cyclic GMP staining in response to post-mortem changes, harmaline and pentobarbitone administration. A role of cyclic GMP is suggested in membrane ion transport.

Animals↗
PubMed1991

Non-invasive 1H NMR spectroscopy of the rat brain in vivo using a short echo time STEAM localization sequence.

Fully localized proton NMR spectra were obtained from the brains of normal anaesthetized rats in vivo using stimulated echo (STEAM) spectroscopy sequences. Investigations were carried out at 2.35 T using a 40 cm bore magnet equipped with an actively shielded gradient system. Localized shimming resulted in water proton linewidths of 6.5-7.8 Hz permitting excellent water suppression. Thus, high-quality proton NMR spectra (TE = 20 ms) were acquired within measuring times of 1.5-6.4 min from 64 to 125 microL volumes-of-interest. The spectra show metabolite resonances due to N-acetyl aspartate, glutamate, creatine and phosphocreatine, cholines, taurine and inositols. The assignments of strongly spin-coupled resonances were confirmed by comparison with spectra from model solutions obtained under identical experimental conditions to those used in vivo. T1 relaxation times as well as relative metabolite concentrations were evaluated from spectra obtained for repetition times ranging from 900 to 6000 ms. Sequential acquisitions of 1.5 min spectra before, during and after killing the animals exhibited a rapid accumulation of lactate, but did not reveal significant changes in other metabolite levels for several hours post mortem.

Animals↗
PubMed1984

Studies on neurotransmitter receptor systems in neocortex and hippocampus in senile dementia of the Alzheimer-type.

Ligand binding to alpha 1-, alpha 2- and beta-adrenergic, serotonin, benzodiazepine and GABA receptors was studied in neocortex and hippocampus of controls and patients with senile dementia of the Alzheimer-type. A selective loss of serotonergic binding sites characterised as a loss of both S1 and S2 sites was observed. The reduction in serotonin receptors did not correlate with a clinical assessment of the degree of dementia, or with the extent of Alzheimer-type neuropathological change.

Aged↗
PubMed1996

Hepatocyte vacuolation and autolytic changes in the liver of pilot whales, Globicephala melas, stranded on Cape Cod, MA, USA.

Most cetacea available for internal sampling in recent times have died through mass or single stranding events. It is important to know how the time elapsed between death and sampling affect quality of tissues. This study evaluated histological quality in the liver of long-finned pilot whales that either died or were euthanased after mass stranding events. Histological detection of significant autolysis was found in animals when 2 or more hours elapsed between death and sampling. In addition, hepatocytes often had marked idiopathic cytoplasmic vacuolation that did not stain with hematoxylin and eosin. The extent of this vacuolation did not show any correlation with time between death and sampling, but did appear more often in animals of greater total length. These observations suggest that when animals die or are euthanased at a single or mass stranding, every effort should be made to obtain samples as soon as possible, although meaningful histological observations can still be made in the presence of significant autolysis. These data also suggest that a multi-disciplinary study should be conducted to determine whether increasing autolysis is associated with changes in the organic chemical residues, molecular biology, histopathology and microbiology of those tissues.

Animals↗