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PubMed1989

Serotonin- and catecholamine-related substances in the brain of ornithine transcarbamylase-deficient Sparse-fur mice in the hyperammonemic state: comparison of two procedures for obtaining brain extract, decapitation and microwave irradiation.

Increased flux through the 5-HT pathway during hyperammonemia was indicated by a significant positive correlation between Gln concentration and the ratio of 5-HIAA to 5-HT in the brain of spf mice taken after microwave irradiation to prevent postmortem changes in metabolites. There were no significant changes in the catecholamine pathway in the brain during hyperammonemia despite the increases in Try and Phe.

Ammonia↗

PubMed2004

Quantitative assessment of infarct size in vivo by myocardial contrast echocardiography in a murine acute myocardial infarction model.

BACKGROUND: In vivo measurement of the infarct size in a small animal model is still challenging. The purpose of this study was to evaluate the feasibility of quantitative assessment of infarct size by myocardial contrast echocardiography (MCE) in the acute myocardial infarction (AMI) model of the rat. METHODS: In 32 Sprague-Dawley rats with AMI, we measured total myocardial area (TMA) and infarct area (IA) of the rats by MCE study (MCE method). They were compared with those of postmortem heart measured by planimetry after histochemical staining with triphenyl tetrazolium chloride solution (TTC method). Simple TTC staining was done in 13 rats (Group 1). To reduce the postmortem change, continuous aortic and left ventricular (LV) pressure was loaded during TTC staining in 19 rats (Group 2). RESULTS: The TMA, IA, and IA/TMA ratio measured by the MCE method were 38.4+/-3.4 mm2, 18.3+/-0.8 mm2, and 0.37+/-0.02 in Group 1, and 43.7+/-1.8 mm2, 15.8+/-1.1 mm2, and 0.37+/-0.02 Group 2, respectively. Those measured by the TTC method were 66.1+/-2.2 mm2, 29.3+/-1.1 mm2, and 0.44+/-0.01 in Group 1, and 65.9+/-2.5 mm2, 26.5+/-1.7 mm2, and 0.40+/-0.02 in Group 2, and 65.9+/-2.5 mm2, 26.5+/-1.7 mm2, and 0.44+/-0.02 in Group 2, respectively. Compared with the TTC method, the MCE method underestimated the TMA and IA in both groups (p<0.001). There was no difference in TMA and IA between the two groups in both methods. IA/TMA ratio showed significant correlation between the two methods in both groups (r=0.85, p<0.001). CONCLUSION: The IA/TMA ratio measured by the MCE method may be useful for in vivo estimation of the myocardial infarct size in the AMI model of the rat.

Animals↗

PubMed2003

Artefact in forensic medicine: scrotal mummification.

Misinterpretation of postmortem artefacts in forensic medical practice may result in a misdiagnosis of criminal activity. Forensic physicians at the scene can liaise with forensic pathologists and visit the mortuary in the company of the crime scene investigators or scenes-of-crime officers to ensure all relevant facts are identified. In this case a postmortem change created by partial dessication of the scrotal skin was misinterpreted as a suspicious injury.

Journal Article↗

PubMed2006

Computed tomographic anatomy of the head of the loggerhead sea turtle (Caretta caretta).

The heads of three loggerhead sea turtles were disarticulated and imaged immediately to minimize postmortem changes and then frozen and sectioned. For computed tomography (CT) imaging, the heads were positioned in ventral recumbency. Transverse CT images with soft-tissue window were obtained from the olfactory sac region to the temporomandibular joint region. After CT imaging, the heads were sectioned and the gross sections were compared to CT images, to assist in the accurate identification of the anatomic structures. Different clinically relevant anatomic structures were identified and labelled in two series of photographs (CT images and anatomic cross-sections). CT images provided good differentiation between the bones and the soft tissues of the head. The information presented in this paper should serve as an initial reference to evaluate CT images of the head of the loggerhead sea turtle and to assist in the interpretation of lesions of this region.

Animals↗

PubMed2003

Glycogen synthase kinase (GSK)-3beta levels and activity in a neurodevelopmental rat model of schizophrenia.

We have previously reported reduced GSK-3beta protein levels and GSK-3 total (alpha + beta isoforms) activity in postmortem frontal cortex of schizophrenic patients. We now studied whether GSK-3beta is altered in the frontal cortex of rats with the neonatal excitotoxic hippocampal lesion used as a model of schizophrenia. Rats were infused with ibotenic acid (or artificial CSF in controls) bilaterally into the ventral hippocampus (VH) at postnatal day 7, then killed at postnatal day 35 (pre-puberty) or 56 (post-puberty). GSK-3beta protein levels were reduced in the frontal cortex of the lesioned rats as compared to sham animals; post-hoc comparisons revealed that the reduction was statistically significant at a pre-pubertal age. Total GSK-3 (alpha + beta) activity was not different between lesioned and sham rats at any age. These results demonstrate that reduced frontal cortical GSK-3beta levels may occur as a result of neonatal hippocampal damage and suggest that this animal model may be utilized to study the mechanism of GSK-3 reduction in schizophrenia, a disorder in which postmortem changes in GSK-3 were found.

Age Factors↗

PubMed1999

A 'keyhole lesion' gunshot wound in an adipocere case.

A corpse completely converted into adipocere and showing two adjacent bone defects--a typical gunshot entrance wound and a keyhole lesion--is reported. Postmortem changes, a comminuted fracture of the cranial base, and destruction of the bullets made it impossible to determine the direction of fire through the keyhole lesion. Gunshot wounds may show various atypical forms, including keyhole lesions, and especially in old corpses, the distinction between an entrance wound and an exit wound can be very difficult, even if a careful complete autopsy is performed.

Journal Article↗

PubMed1999

Forensic diagnosis of death from cold.

To clarify the forensic diagnosis of hypothermia, the postmortem changes in the bodies of 211 cases of hypothermia (partly including death from diseases) encountered between January 1990 and January 1999 were studied as follows:i) The rectal temperature had been measured in 83 cases in which the time after death was known relatively clearly, and the rate of decrease in the rectal temperature per hour was evaluated. The rate of decrease in the rectal temperature was 2.3 +/- 1.2 degrees C, 2.7 +/- 1.5 degrees C and 3.6 +/- 1.9 degrees C per hour (mean +/- SD) when the ambient temperature was > or = 0 degrees C, 0 degrees C > to >-10 degrees C and -10 degrees C > or =, respectively. ii) The color of blood collected from the right and left hearts was different in 43 (33.6%) of the 128 cases of death from cold that underwent inquest and in 20 (87.0%) of the 23 cases that underwent forensic autopsy. This color difference was useful for the diagnosis of fatal hypothermia. iii) Gastric or duodenal submucosal bleeding (Wishnewski's spots) was noted in 10 (43.5%) of the 23 cases that underwent forensic autopsy. iv) Paradoxical undressing was observed in 35 (21.3%) of the 164 cases that underwent inquest.

Journal Article↗

PubMed1996

A case of deferred death from drowning of a man found dead in bed at home.

An autopsy case of deferred death from drowning is reported. A 63-year-old man was found dead wearing wet clothing in his bed at home. At a medico-legal autopsy, mud was observed in the air passages as well as in the stomach, and a total of 210 g pleural effusion was also noted in the thoracic cavity (left 70 g, right 140 g). The left and right lungs were expanded and weighed 800 g and 950 g, respectively. Histological examination revealed the pathological finding of pneumonia with the exudation of numerous leucocytes into the alveoli as well as some postmortem changes. Diatoms were detected in the liver and both lungs by the disorganization method. In addition, scene investigation disclosed that he had fallen into a ditch in front of his house and had inhaled muddy water in the ditch, and had then managed to reach his bed and survive for a while, but dying eventually from aspiration pneumonia as a result of inhalation of exogenous water. The cause of his death was, therefore, given as deferred death from drowning rather than aspiration pneumonia.

Journal Article↗

PubMed2000

An immunohistochemical study on cathepsin D in human hippocampus.

Cathepsin D is a lysosomal enzyme involved in neuronal degeneration. In this study, the immunohistochemistry of cathepsin D was studied in hippocampal CA1 neurons that are vulnerable to ischemia, and parahippocampal glial cells. CA1 neurons from the majority of cases showed cathepsin D immunoreactivity in the cytoplasm, whereas shrunk neurons were unstained in only one case. There was no statistically significant correlation between the postmortem interval between death and autopsy, and cathepsin D immunoreactivity in CA1 neurons. These observations indicate that cathepsin D immunoreactivity is not a sensitive marker for neuronal degeneration or postmortem changes. On the other hand, there was a statistically significant correlation between age and cathepsin D immunoreactivity in the cytoplasm of parahippocampal glial cells. This shows that senescence is correlated with cathepsin D expression in humans as has been reported previously in an animal study.

Adolescent↗

PubMed1991

Role of amniotic fluid cytogenetic analysis in the evaluation of recent fetal death.

Chromosome abnormalities may be present in approximately 10% of cases of fetal death. Because of cell maceration and autolysis, the likelihood of successful karyotype analysis of fetal tissue varies inversely with the time between fetal death and delivery. In an attempt to reduce the influence of these postmortem changes, we obtained amniotic fluid cells for cytogenetic studies from 12 fetuses as soon as possible after the diagnosis of fetal death was confirmed. We also obtained fetal tissue for cell culture in ten of the cases immediately following evacuation of the uterus. Cell culture was successful in 11 of 12 amniotic fluid specimens and in only one of ten fetal tissue specimens (p less than 0.001). Since the results of cytogenetic studies are of such importance in counseling patients regarding recurrence risk for fetal death, we recommend that amniotic fluid cells be obtained for karyotype analysis at the time of diagnosis of fetal death rather than awaiting delivery of a potentially macerated and autolyzed fetus.

Amniotic Fluid↗

PubMed1991

Safety versus efficacy of spinal cord stimulation for the generation of motor-evoked potentials in the rat.

The relative safety and efficacy of direct versus indirect methods of spinal cord stimulation for the production of descending motor-evoked responses was studied in pentobarbital-anesthetized rats (n = 39). Electrical stimuli were delivered for 1 h, either directly to the cord dorsum using silver ball electrodes or indirectly through jeweler's screws implanted in the intact laminae. Compound muscle action potentials (CMAPs) were recorded differentially in the quadriceps and evaluated for their morphology and reproducibility. The traumatic effects of stimulation were assessed using intraoperative somatosensory-evoked potentials, blinded neurological examinations for 2 weeks postoperatively, and histopathological and neurochemical analyses in postmortem spinal tissues. In separate experiments, the neural substrates of the muscle-evoked response to indirect cord stimulation were examined. Direct, epidural stimulation of the spinal cord at intensities sufficient to elicit reproducible CMAPs consistently resulted in mild behavioral deficits (13 of 18 animals) that were accompanied by postmortem changes in spinal histology and chemistry. Some of these behavioral deficits (5 of 13 animals) were resolved at 2 weeks. There was rarely an early sign of motor or sensory conduction derangement in these animals. In 2 animals with severe behavioral dysfunction, the somatosensory-evoked response was abolished immediately after spinal stimulation. However, CMAP responses were unaltered. Examination of the strength-duration relationship for the production of threshold responses to translaminar constant current stimulation, as well as experiments using selective transection of the dorsal columns, revealed the CMAP responses to be neurally mediated and conducted through the cord independent of the ascending sensory tracts that mediate the rat's somatosensory-evoked response. Data are discussed in terms of the potential experimental usefulness of CAMPs elicited by indirect dorsal spinal stimulation.

Action Potentials↗

PubMed1997

Oral autopsy of unidentified burned human remains. A new procedure.

Forensic dentistry plays an increasingly important role in medicolegal investigation and identification procedures. The oral examination may be difficult because of postmortem changes, especially those of carbonized corpses. We present a new technique of oral autopsy that includes a new means of access to the oral cavity designed for application on unidentified burned human remains. This technique preserves the facial configuration of the cadaver, allowing visual recognition by family members or other persons that is fundamental if the antemortem dental records do not exist or are not available. Also, this technique permits adequate work productivity by the forensic team members and can be used in difficult working conditions, such as mass-disaster scenarios.

Autopsy↗

PubMed1997

Particulate matter in the posterior semicircular canal.

The pathoetiology of benign paroxysmal positional vertigo (BPPV) is controversial. Particulate matter within the posterior semicircular canal has been identified intraoperatively in patients with BPPV but has also been reported in non-BPPV patients at the time of translabyrinthine surgery (Parnes LS, McClure JA. Free-floating endolymphatic particles: a new operative finding during posterior semicircular canal occlusion. Laryngoscope 1992;102:988-92; Schuknecht HF, Ruby RRF. Cupulolithiasis. Adv Otorhinolaryngol 1973;20: 434-43; Kveton JF, Kashgarian M. Particulate matter within the membranous labyrinth: pathologic or normal? Am J Otol 1994;15:173-6). The nature of the particulate matter remains unknown. The purpose of this study was to prospectively examine the posterior semicircular canal of patients with and without a clinical history of BPPV for the presence of particulate matter. Seventy-three patients without BPPV symptoms undergoing labyrinthine surgery (vestibular schwannoma excision or labyrinthectomy) and 26 patients with BPPV undergoing the posterior semicircular canal occlusion procedure were compared. Additionally, 70 archived temporal bones without a history of BPPV were examined microscopically for the presence of particulate matter within the lumen of the membranous labyrinth. No particles were observed intraoperatively in any of the 73 patients without a history of BPPV. Particulate matter was observed in 8 of 26 patients at the time of the posterior semicircular canal occlusion procedure for intractable BPPV. Of the 70 temporal bones examined, 31 did not show significant postmortem changes and also did not demonstrate cupulolithiasis or canalithiasis. Particulate matter from within the membranous posterior semicircular canal was removed from one patient at the time of posterior semicircular canal occlusion for intractable BPPV symptoms and was examined by scanning electron microscopy. The particulate matter appeared morphologically consistent with degenerating otoconia. These data show a statistically significant association between the presence of particles within the posterior semicircular canal in this study and the symptom complex of BPPV.

Ear, Inner↗

PubMed1990

In vivo biological effects of stereotactic radiosurgery: a primate model.

Single-fraction, closed skull, small-volume irradiation (radiosurgery) of intact intracranial structures requires accurate knowledge of radiation tolerance. We have developed a baboon model to assess the in vivo destructive radiobiological effects of stereotactic radiosurgery. Three baboons received a single-fraction, 150-Gy lesion of the caudate nucleus, the thalamus, or the pons using the 8-mm diameter collimator of the gamma unit. Serial standard neurodiagnostic tests (neurological examination, computed tomographic scan, magnetic resonance imaging, stable xenon-enhanced computed tomographic scan of cerebral blood flow, somatosensory and brain stem evoked potentials, and myelin basic protein levels of cerebrospinal fluid) were compared with preoperative studies. Magnetic resonance imaging revealed the development of a lesion at the target site between 45 and 60 days after irradiation. Deterioration of the brain stem evoked potentials preceded imaging changes when the lesion encroached on auditory pathways. Myelin basic protein levels increased subsequent to imaging changes. Postmortem neuropathological examination confirmed a well-demarcated radionecrosis of the target volume. The baboon model appears to be an excellent method to study the in vivo biological effects of radiosurgery.

Animals↗

PubMed1976

The structure and permeability of isolated hepatocyte gap junctions.

The ultrastructure of the gap junction may be visualized in both in situ and isolated preparations by using a variety of electron microscope techniques. The junction is composed of a lattice of subunits, called connexons, which show variable degrees of packing into a hexagonal lattice depending on a variety of poorly understood conditions. In general, it appears that more uncoupled and "dead" the junction, the more regular and condensed the hexagonal lattice becomes. It is not yet known whether these are "postmortem" changes or physiologically active and reversible changes involved in regulation of junctional permeability. Using a variety of techniques, it can be seen that the connexon extends completely across the junctional membranes, from the cytoplasmic surface of one cell to the cytoplasmic surface of the other, spanning the 2-nm "gap" between the apposed junctional membranes. Thus it is possible to implicate the connexon as a permeability channel from cytoplasm to cytoplasm, although the hydrophilic pore through the center of the connexon has not yet been demonstrated to span the full junction thickness. X-ray diffraction experiments support these conclusions, and the excellent correlation between the electron microscope and X-ray diffraction data lends great confidence to the interpretations of gap junction structure presented thus far. These data are summarized in the drawing in Figure 17. This is a scale drawing of two connexons, each of which is imagined to be composed of a dimer of hexamers. It must be emphasized that as yet there is no direct evidence for a sixfold symmetry within the connexon. Of special interest now are the types of protein-protein interactions that hold the two halves of the connexon together across the 2-nm gap and the lateral interactions between the connexons at the level of the lipid bilayers.

Animals↗

PubMed1979

Central nervous system defects in early human abortuses.

Thirteen embryos with various central nervous system (cns) defects were examined macroscopically and by serial sectioning, and were compared with seven control embryos. All had been aborted spontaneously. Examples of anencephaly, anencephaly with spina bifida, spina bifida alone, encephalocele, iniencephaly and cyclops were found. Histological assessment was directed mainly to the cns, the skeletal axis, the neural-crest derivatives and remaining viscera. The cns was affected by postmortem change in some cases. Brain tissue was absent in most anencephalic embryos and spinal-cord tissue was absent at the level of the external lesion in all except one of the spina-bifida embryos. Defects such as diastematomyelia were found occasionally. Widespread abnormalities were found in the cartilaginous vertebral colun. The meninges were unusually vascular, but other neural crest derivatives appeared to be normal. The possible causes of absent brain or spinal cord are discussed and the findings are compared with the pathology of cns defects in childhood.

Abortion, Spontaneous↗

PubMed1991

The posttranslational processing of beta-endorphin in human hypothalamus.

beta-Endorphin is posttranslationally processed to six derivatives, which, although structurally similar, produce distinctly different biological effects. beta-Endorphin 1-31 is a potent opioid receptor agonist, but beta-endorphin 1-27 exhibits antagonist properties, and beta-endorphin 1-26 and the alpha-N-acetyl derivatives of all three peptides lack opioid receptor activity. In the present study, we identified the beta-endorphin peptides synthesized in human hypothalamus using cation exchange HPLC. First, we tested whether postmortem changes occur by storing rat hypothalami at 4 degrees C. This demonstrated that relative amounts of the six beta-endorphin forms did not change for up to 24 h, although total beta-endorphin immunoreactivity significantly declined after 6 h. HPLC analysis of human hypothalami revealed that beta-endorphin 1-31 was the principal form, constituting 58.4 +/- 5.4% of total immunoreactivity. Substantial amounts of beta-endorphin 1-27 (13.4 +/- 1.2%) and beta-endorphin 1-26 (13.1 +/- 1.6%) were also present, but alpha-N-acetylated forms were quantitatively minor, each comprising approximately 5% of total beta-endorphin. A similar processing pattern occurred in preoptic and suprachiasmatic areas of the hypothalamus. These results show that, despite differences in primary sequence, beta-endorphin is processed similarly in both rat and human hypothalamus. Opiate-active beta-endorphin 1-31 is the principal form in both species.

Adult↗

PubMed1973

Cyclic adenosine monphosphate, metabolites, and phosphorylase in neural tissue: a comparison a methods of fixation.

Fixation of rat brain tissue by freeze-blowing, microwave irradiation, immersion of whole rats in liquid nitrogen, and decapitation into liquid nitrogen indicates that postmortem changes in metabolites and enzyme forms are minimal in freeze-blown brains. Cyclic adenosine monophosphate levels are lowest in microwave-irradiated brains, which has been interpreted by some investigators to indicate rapid fixation and minimal anoxia. However, the changes in phosphocreatine, adenosine triphosphate, lactate, and phosphorylase clearly demonstrate that fixation by freeze-blowing or immersion in liquid nitrogen more closely approximate the state in vivo.

Adenosine Triphosphate↗