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PubMed1984

Postmortem and regional changes of serotonin, 5-hydroxyindoleacetic acid, and tryptophan in brain.

Using a specific and sensitive high pressure liquid chromatographic technique for the measurement of serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and tryptophan (TRP), we found that there were no changes in 5-HT or 5-HIAA in the rat cortex when left in situ for 6 h at room temperature or 24 h at 4 degrees C. Only a minimal 14% increase in 5-HT was observed after 24 h at 4 degrees C in the striatum of the same animals. Concentrations of TRP, however, were increased significantly in both brain regions by these postmortem delay procedures. A second study revealed that there were significant regional 5-HT and 5-HIAA concentration differences within the cerebral cortex. The frontal cortex was shown to have the highest concentrations of 5-HT and 5-HIAA. Further, within the frontal cortex, 5-HIAA levels varied, showing apparent progressive rostral to caudal increases. 5-HT concentrations, however, remained constant within the frontal cortex. These results are discussed in reference to the conflicting reports of the previous human suicide and postmortem studies.

Animals↗
PubMed1997

Effects of electrical stimulation and postmortem storage on changes in titin, nebulin, desmin, troponin-T, and muscle ultrastructure in Bos indicus crossbred cattle.

The effects of electrical stimulation (ES) on degradation of titin, nebulin, desmin, and troponin-T (TN-T) and on structural changes in the longissimus muscle (LM) from Brahman x Simmental (B x S) cattle (Bos indicus cross) were determined. The left side of seven B x S beef carcasses was stimulated (200 V, 20 Hz) within 1 h of death, and the right side was the nonstimulated (NS) control. Myofibrils for SDS-PAGE and samples for transmission electron microscopy were prepared from the LM at 0, 1, 3, 7, 14, and 28 d postmortem (PM). The SDS-PAGE results showed that the T1 band of titin was absent by 7 d in two animals, by 14 d in four animals, and by 28 d in one animal in both NS and ES samples. By SDS-PAGE, intact nebulin was gone by 7 d in two animals and by 14 d in five animals, but in blots, nebulin decreased by 7 d and was absent by 14 d in both NS and ES samples. The desmin band could still be seen as a light band at 28 d in Western blots of both NS and ES samples. A decrease in TN-T and a concomitant increase in the 30-kDa polypeptide were observed in both NS and ES samples. Western blots with a monoclonal antibody to TN-T confirmed that TN-T decreased at similar rates in NS and ES samples but showed that the 30-kDa polypeptide was more heavily labeled in ES samples from 7 to 28 d. Contraction nodes were present in O-d ES samples and were still observed in 28-d ES samples. Narrow, intermediate, and wide I-band fractures were seen earlier and at a greater frequency in ES than in NS samples. Overall, ES had no detectable effect on titin, nebulin, desmin, or TN-T degradation but accelerated the appearance and enhanced the frequency of three types of I-band fractures in the LM from Bos indicus crossbred cattle.

Animals↗
PubMed2006

Estimation of postmortem interval from human pericardial fluid electrolytes concentrations in Chandigarh zone of India: log transformed linear regression model.

Estimation of postmortem interval from changes in postmortem pericardial fluid electrolytes concentration is the topic of discussion in the study. Querido [Querido D. Double logarithmic, linear relationship between plasma sodium/potassium concentration ratio and postmortem interval during the 6-96h postmortem period in rats. Forensic Sci Int 1990;44:125-34; Querido D. Linearization of the relationship between postmortem plasma chloride concentration and postmortem interval in rats. Forensic Sci Int 1990;45:117-27] and Singh et al. [Singh D, Prashad R, Parkash C, Bansal YS, Sharma SK, Pandey AN. Linearization of relationship between serum sodium, potassium concentration, their ratio and time since deaths in Chandigarh zone of north west India. Forensic Sci Int 2002;130:107; Singh D, Prashad R, Parkash C, Sharma SK, Pandey AN. Double logarithmic linear relationship between plasma chloride concentration and time since death in humans in Chandigarh zone of north west India. Legal Med 2003;5:49-54] had demonstrated a highly significant double logarithmic linear relationship between the time since death and the plasma sodium/potassium ratio as well as with plasma chloride concentration in Wistar rats and human, respectively. In view of these facts, the present study was carried out to substantiate this propensity in this transcellular extension of blood plasma. Electrolytes analysis in postmortem pericardial fluid obtained from 311 subjects revealed that correlation of time since deaths with potassium, sodium/potassium ratio and phosphorus was highly significant (p<0.001) during 2.5-58h of deaths. Not withstanding, time since death although modulated by ambient temperature could be predicted by log transformed multiple regression equation derived from the combination of potassium, chloride and phosphorus electrolytes concentration with standard error (SE) of prediction (in log hours) of 0.1840h and by double logarithmic model with SE (in log hours) of 0.1959, 0.2068 and 0.2088h from potassium, sodium/potassium ratio and phosphorus electrolytes, respectively.

Electrolytes↗
PubMed1992

Changes in vitreous humor associated with postmortem interval in rabbits.

Concentrations of serum and vitreous humor constituents at time of death, and concentrations of vitreous humor constituents at time of death and at 7 postmortem intervals were compared in 70 domestic, female New Zealand White rabbits (Oryctolagus cuniculus). Urea nitrogen concentration was significantly (P = 0.0094) different, but was linearly correlated in serum and vitreous humor at time of death and at the 4- and 8-hour postmortem intervals. Concentrations of gamma-glutamyltransferase were not significantly different in serum and vitreous humor at time of death, nor were concentrations significantly different in vitreous humor at time of death and at the 4-hour postmortem interval. The vitreous humor concentrations of glucose, triglycerides, sodium, potassium, cholesterol, total protein, albumin, lactate dehydrogenase, creatine kinase, aspartate transaminase, bilirubin, cortisol, and IgG were neither similar to nor predictive of serum constituents. Vitreous humor can be used as a source for estimates of serum urea nitrogen and gamma-glutamyltransferase up to 8 and 4 hours after death, respectively.

Albumins↗
PubMed1986

Inositol bis-, tris-, and tetrakis(phosphate)s: analysis in tissues by HPLC.

The concentration of isomers of inositol tris(phosphate) (InsP3) was measured in tissues of intact animals. The method employed involved anion-exchange HPLC with on-line enzymatic hydrolysis of the phosphate esters and detection of the inorganic phosphate formed. All seven organs tested from rats killed by decapitation contained Ins(1,4,5)P3 in concentrations of 13-40 nmol/g; a distribution that bears no resemblance to that reported for its precursor [phosphatidylinositol bis(phosphate)]. A second InsP3 isomer [probably Ins(1,3,4)P3] was also detectable in brain and salivary gland. The content of Ins(1,4,5)P3 in brain and salivary gland from rats killed by decapitation was 10-60 times greater than that from rats killed by focused microwave irradiation to block postmortem metabolism. Inositol bis(phosphate) concentrations also changed dramatically postmortem. A much smaller postmortem change was seen in the content of Ins(1,3,4)P3. Receptor stimulation by muscarinic cholinergic agonists increased the content not only of Ins(1,3,4)P3, but also its recently discovered probable precursor, inositol tetrakis-(phosphate).

Animals↗
PubMedDate not supplied

[Changes in rat skeletal muscle actin during postmortem autolysis].

Electrophoretic analysis of actin, obtained within 1.2 and 5 days after death, did not exhibit any destructions of the protein. At the same time, an ability of actin to develop the actomyosin complex was decreased during autolysis as shown by affinity chromatography of actin on CNBr-Sepharose containing immobilized myosin. Alterations in fluorescence spectra of the actin preparations enabled to suggest that an increase of inactive, unable to polymerization form of the protein during autolysis was responsible for reduction of its property to associate with myosin.

Actins↗
PubMed1990

High resolution scanning electron microscopy of stereocilia in the cochlea of normal, postmortem, and drug-treated guinea pigs.

The morphology of hair bundles has been studied by high resolution scanning electron microscopy using a variety of fixatives, including glutaraldehyde, glutaraldehyde-picrate, glutaraldehyde-tannic acid, glutaraldehyde followed by post-fixation in osmium tetroxide, and the osmium thiocarbohydrazide technique. Critical evaluation of several metal coatings, gold, gold-palladium, and platinum has been carried out. Both the surface texture of stereocilia and their cross-links are sensitive to fixation and metal coating. We are of the opinion that glutaraldehyde gives the best general quality of fixation and preservation for all types of cross-links. We have described three major sets of cross-links: first, lateral links connecting stereocilia within the same row; second, lateral links connecting stereocilia of adjacent rows; and third, upward-pointing links, one per stereocilium, connecting the tip of each shorter stereocilium to the lateral surface of the adjacent taller stereocilium. Current physiological and anatomical evidence suggests that the lateral links couple the individual stereocilia within the hair bundle so that they function as a single mechanical unit. The upward-pointing tip links are ideally placed to respond to mechanical deformation of the hair bundle, being stretched when the stereocilia are deflected in the excitatory direction towards the tallest row and relaxed when deflected in the opposite, inhibitory direction. Postmortem morphological changes are detected within 15 minutes of cardiac arrest and become progressively more pronounced in time. These results enabled us to distinguish specific drug-induced changes which could not be attributed simply to cell death. Effects of cisplatin and kanamycin upon hair bundles are described. The work reported here is based on studies using the guinea pig cochlea. Some of the postmortem changes described have also been confirmed in human cochleas. It is stressed that many of the postmortem and drug-induced effects can only reliably be studied by high resolution scanning electron microscopy coupled with appropriate preparation procedures.

Animals↗
PubMed2001

[Study on the relationship between postmortem interval and the change of absorbance in vitreous humor of rabbit after death].

OBJECTIVE: To seek a exact method of estimating Postmortem interval (PMI). METHODS: This study was preformed to investigate the relationship between postmortem interval and absorbance in vitreous humor of rabbit after death. The absorbance in vitreous humor of 48 rabbits after death were investigated with Model 754 spectrophotometer in apt wavelength (420 nm). RESULTS: There exists positive linear regression association between postmortem interval (Y) and absorbance in vitreous humor (X) (r = 0.98327, P < 0.05), during rabbits after death 0 to 72 hours. The formula of linear regression is Y = 453.30 X + 0.75 (Y = postmortem interval = PMI, X = absorbance in vitreous humor). CONCLUSION: The absorbance in vitreous humor can be as reference indicator to estimate PMI within hour 72.

Animals↗
PubMed1995

Vitreous humor cocaine and metabolite concentrations: do postmortem specimens reflect blood levels at the time of death?

The interpretation of postmortem cocaine concentrations is made in an attempt to estimate drug concentrations present at the time of death and thus infer not only drug presence but drug toxicity. Previous data suggest that changes in postmortem blood cocaine concentrations over time are not predictable and interpretation of cocaine levels should be done with caution. However, these data come from autopsy case series where vital information, such as blood cocaine concentration at the time of death, dose and time since last use, and postmortem interval is often not known. The purpose of this study was to characterize postmortem changes in cocaine and metabolite concentrations relative to premortem concentrations over time at two anatomic sites: peripheral blood and vitreous humor, in a controlled, large animal model. Juvenile swine were given cocaine HCl 10 mg/kg as an IV bolus which resulted in seizures and wide complex tachycardia. Five minutes after cocaine administration, animals were euthanized. At time of death and eight hours postmortem, femoral venous blood and vitreous humor (VH) samples were obtained for quantitation of cocaine, benzoyl ecgonine (BE), and ecgonine methyl ester (EME) by GC/MS. There were no significant increases over time in mean femoral vein concentrations of cocaine or BE. However, a large interanimal variability in direction and magnitude of concentration changes was seen. Mean EME concentrations at the femoral site increased significantly over 8 hours (P < 0.03). Mean VH cocaine concentrations at time of death were significantly lower than corresponding blood concentrations (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Changes of biogenic amines and their metabolites in postmortem brains from patients with Alzheimer-type dementia.

Noradrenaline (NA), 3,4-dihydroxyphenylethylamine (dopamine, DA), 5-hydroxytryptamine (serotonin, 5-HT), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were measured in 22 regions of postmortem brains from four histologically verified cases with Alzheimer-type dementia (ATD) and nine histologically normal controls. Compared with the controls, concentrations of 5-HT and 5-HIAA in the ATD brains were significantly reduced in nine regions (superior frontal gyrus, insula, cingulate gyrus, amygdala, putamen, medial and lateral segments of globus pallidus, substantia nigra, lateral nucleus of thalamus) and in eight regions (amygdala, substantia innominata, caudate, putamen, medial and lateral segments of globus pallidus, medial and lateral nuclei of thalamus), respectively. NA concentrations of the ATD brains were significantly reduced in six regions (cingulate gyrus, substantia innominata, putamen, hypothalamus, medial nucleus of thalamus, raphe area). In contrast, significant reductions of DA and HVA concentrations in the ATD brains were found only in putamen and amygdala, respectively. The 5-HIAA/5-HT ratio in the ATD brains decreased significantly in locus coeruleus, while the HVA/DA ratio increased significantly in putamen and medial segment of globus pallidus. These findings suggest that the serotonergic and noradrenergic systems are affected, while the dopaminergic system is relatively unaffected in ATD brains.

Alzheimer Disease↗
PubMed1999

[Study of elastic fiber changes of human skin in distinction between antemortem and postmortem wounds].

Elastic fiber changes of volunteers' antemortem and postmortem skin wounds of various time were observed in order to find possible differences between them. These sections of the wounds were stained by Hart's modification of Weigert's elastic tissue stain.. However, this study showed that there were no differences in the nature and distribution of the elastic fibers in the dermis of volunteers' antemortem and postmortem human skin wounds. Therefore, this suggests that the appearances of the elastic fibers in the dermis should not be as a means of differentiating antemortem skin wounds from postmortem wounds in forensic identification.

Adolescent↗
PubMed2003

[The relationship between the postmortem interval and the changes of DNA content in rabbit's cornea epithelial and endothelium by the computerized image analysis].

OBJECTIVE: To study the relationship between the postmortem interval (PMI) and the changes of DNA content in rabbit's cornea epithelial and endothelium. METHODS: Using the computerized image analysis to measure the DNA content in the cornea epithelial and endothelium of 105 rabbit's at every six hours during 72 hours after death. RESULTS: The degradation rate of DNA in nuclear has an apparent relationship in 72 hours after death of the rabbits. CONCLUSION: The determination of the quantity of DNA in cornea nuclear is a new method to estimate the PMI accurately.

Animals↗