Fatal hypothermia related vacuolation of hormone-producing cells in the anterior pituitary

Immunohistochemical insights into hypothermia-related deaths: a systematic review

PURPOSE

Hypothermia occurs when core body temperature drops below 35 °C. The purpose of this review was to identify and analyze studies on the topic of hypothermia from an immunohistochemical perspective to determine robust markers of fatal hypothermia.

METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. It has been registered with Prospero (registration number: CRD42024572782).

RESULTS

In total, 2618 publications met the search criteria. A total of 63 duplicate articles were excluded and a further 2489 publications were excluded for not meeting the inclusion criteria, leaving 29 full-text articles. Furthermore, from the bibliographies of the included articles, four more publications were selected, which also respected the established inclusion and exclusion criteria. Only six studies identified a statistically significant correlation between immunohistochemical patterns and hypothermia-related deaths.

CONCLUSION

The existing literature examined appears fragmented and lacks robust statistical validation. Therefore, there is an evident need for more comprehensive and methodologically rigorous research to develop reliable diagnostic criteria.

Renal expression of Hsp27, 60, and 70 in cases of fatal hypothermia

Macromorphological findings can be missing in cases of fatal hypothermia when the agonal period is very short because of a large difference between environmental and core body temperatures. Expression of heat shock proteins (Hsps) increases under endogenous and exogenous cellular stresses such as thermal stress. These stress proteins can be revealed by immunohistochemical staining. Forty-five cases of death due to hypothermia and a control group of 100 deaths without any antemortem thermal stress were examined for Hsp27, 60, and 70 expression in renal tissue because renal tissue is sensitive to cellular stress. The results revealed no significant difference between Hsp27, 60, and 70 expression in both groups (28.8% positive staining in the study group and 19.0% positive staining in the control group), which is contradictory to a previous study on expression of Hsp70 in renal tissue in cases of fatal hypothermia. Hence, it is currently unclear whether immunohistochemical staining of Hsps supports a morphological diagnosis of fatal hypothermia.

Cortisol levels after cold exposure are independent of adrenocorticotropic hormone stimulation

We previously showed that postmortem serum levels of adrenocorticotropic hormone (ACTH) were significantly higher in cases of hypothermia (cold exposure) than other causes of death. This study examined how the human hypothalamic-pituitary-adrenal axis, and specifically cortisol, responds to hypothermia. Human samples: Autopsies on 205 subjects (147 men and 58 women; age 15-98 years, median 60 years) were performed within 3 days of death. Cause of death was classified as either hypothermia (cold exposure, n = 14) or non-cold exposure (controls; n = 191). Cortisol levels were determined in blood samples obtained from the left and right cardiac chambers and common iliac veins using a chemiluminescent enzyme immunoassay. Adrenal gland tissues samples were stained for cortisol using a rabbit anti-human polyclonal antibody. Cell culture: AtT20, a mouse ACTH secretory cell line, and Y-1, a corticosterone secretory cell line derived from a mouse adrenal tumor, were analyzed in mono-and co-culture, and times courses of ACTH (in AtT20) and corticosterone (in Y-1) secretion were assessed after low temperature exposure mimicking hypothermia and compared with data for samples collected postmortem for other cases of death. However, no correlation between ACTH concentration and cortisol levels was observed in hypothermia cases. Immunohistologic analyses of samples from hypothermia cases showed that cortisol staining was localized primarily to the nucleus rather than the cytoplasm of cells in the zona fasciculata of the adrenal gland. During both mono-culture and co-culture, AtT20 cells secreted high levels of ACTH after 10-15 minutes of cold exposure, whereas corticosterone secretion by Y-1 cells increased slowly during the first 15-20 minutes of cold exposure. Similar to autopsy results, no correlation was detected between ACTH levels and corticosterone secretion, either in mono-culture or co-culture experiments. These results suggested that ACTH-independent cortisol secretion may function as a stress response during cold exposure.

Identification of potential markers of fatal hypothermia by a body temperature-dependent gene expression assay

Diagnosis of fatal hypothermia is considered to be difficult in forensic practice and even if findings due to cold exposure are evident, cold exposure is not necessarily a direct cause of death. Identification of useful molecular markers for the diagnosis of fatal hypothermia has not been successful. In this study, to identify novel molecular markers that inform the diagnosis of fatal hypothermia, we focused on skeletal muscle, which plays a role in cold-induced thermogenesis in mammals. We made rat models of mild, moderate, and severe hypothermia and performed body temperature-dependent gene expression analysis in the iliopsoas muscle using next-generation sequencing (NGS). NGS showed that after severe hypothermia, the expression levels of 91 mRNAs were more than double those in mild and moderate hypothermia and control animals. Gene ontology (GO) analysis indicated that these mRNAs are involved in a number of biological processes, including response to stress and lipids, and cellular response to hypoxia. The expression of four genes [connective tissue growth factor (Ctgf), JunB proto-oncogene, AP-1 transcription factor subunit (Junb), nuclear receptor subfamily 4, group A, member 1 (Nr4a1), and Syndecan 4 (Sdc4)] and the level of one protein (CTGF) were induced only by severe hypothermia. These genes and protein are involved in muscle regeneration, tissue repair, and lipid metabolism. These results indicate that heat production to maintain body temperature in a process leading to fatal hypothermia might be performed by the iliopsoas muscle, and that Ctgf, Junb, Nr4a1, and Sdc4 genes are potential diagnostic markers for fatal hypothermia.

The Adult Pancreas in Trauma and Disease

The spectrum of traumatic and natural disease that can affect the adult pancreas is multiple and varied. Some entities are more commonly encountered in routine forensic pathology practice and the forensic pathologist needs to be very familiar with their pathological features and development from a pathophysiological perspective. However, many of the conditions are extremely rare and may never be encountered in the professional lifetimes of an individual pathologist. Still, forensic pathologists need to be aware of them in case they are one day faced with these entities as possible diagnoses to be established at postmortem examination. This can be the result of clinical concerns raised in life, potential natural disease explanations for unexpected biochemical results, and sudden, unexpected or otherwise unexplained deaths where criminal concern about the exogenous administration of a substance must be considered. Acad Forensic Pathol. 2018 8(2): 192-218.

Microscopic examination of pituitary glands in cases of fatal accidental hypothermia

In cases of death caused by hypothermia, histological analysis can be used to determine the cause of death. Certain histological alterations of the pituitary glands in hypothermia have been reported in the literature, including haemorrhage, hyperaemia and cellular vacuolization of cells in the anterior lobe. In the present study, the validity of these morphological alterations as markers for fatal accidental hypothermia was investigated in autopsy material. A total of 34 pituitary glands in cases of verified fatal accidental hypothermia were examined histologically (haematoxylin and eosin, ferric, azan) and immunohistochemically (LCA, ACTH, C5b-9). The findings were compared with 61 cases in a control group. Hyperaemia was found in 50.0% of the study group cases and 59.0% of the control group cases. Cellular vacuolization was observed in one case (2.9%) in the study group and one case (1.6%) in the control group. Acute or recent haemorrhage in the glandular tissue was never detected. In our study, the histopathological characteristics described in the literature as pathognomonic for hypothermia could not be confirmed. Furthermore, histological differences in the pituitary glands between fatal hypothermia cases and control group cases were not observed.

Effects of therapeutic agents on cellular respiration as an indication of metabolic activity

Animal experiments are indispensable in the investigation of the toxicity of drugs on cells, but may not be preferred for ethical reasons and sensitivity. As an alternative procedure, we investigated the susceptibility of cells to drugs using the effect on cellular respiration as an indicator of cell activity (toxicity). The primary cultures (cell lines) used in this study included human fetal myocardial cells, skeletal muscle cells, nerve cells, hypophyseal cells, epithelial cells of gastric mucosa, lymphocytes, hepatocytes, pancreatic (exocrine) cells, renal tubular epithelial cells and fetal adrenal cortex cells, which were obtained from the American Type Culture Collection (ATCC). The drugs used were diazepam, haloperidol and levomepromazine maleate (psychoactive drugs), cisplatin and doxorubicin hydrochloride (anticancer agents). The cells were used at a density of 2–106 cells/2 mL of growth medium and, to test the susceptibility, each drug was prepared at a concentration of 10 g/mL. Experiment results indicated that, even with the same drug, sensitivity was markedly different depending on the cell lines. Cardiac muscle cells showed the strongest respiratory inhibition by Serenace and were least inhibited by Hirnamin. The highest sensitivity to Cercine was noted for neurons, while gastric mucosa cells had almost no sensitivity. Sensitivity to Serenace, which was expected to have a strong nerve action, was higher in myocardial cells instead. In the present study, we suggested the possibility of studying individual differences in drug sensitivity through investigation of toxicity in each organ as opposed to toxicity in the individual. In addition, Serenace, which was developed as a neurotopic agent, showed a higher toxicity in cardiac muscle cells than in neurons. This finding appeared noteworthy, not only for forensic toxicology, but also for clinical practice and drug development.

Death from Hypothermia during a Training Course under "Extreme Conditions": Related to Two Cases

Death from hypothermia following exhaustion or from various complicated pathologies is no longer a frequent cause of death among combat troops. During a training course under "extreme conditions" in the French Alps, two young African officers died. Confronted with these two clinically confirmed cases of hypothermia, the unknown anatomopathological and biological specificities associated with death from hypothermia were highlighted. In these typical and clinically confirmed cases of death from subacute exhaustion hypothermia, none of the signs revealed by the autopsy were specific. Although some recent publications have addressed the utility of postmortem biochemical markers when establishing a diagnosis, with no anamnesis, with no knowledge or analysis of the circumstances of death, and without an in situ examination of the body, it appears difficult, if not impossible, to confirm that death was caused by hypothermia.

Heterogeneous genetic background of the association of pheochromocytoma/paraganglioma and pituitary adenoma: results from a large patient cohort

CONTEXT

Pituitary adenomas and pheochromocytomas/paragangliomas (pheo/PGL) can occur in the same patient or in the same family. Coexistence of the two diseases could be due to either a common pathogenic mechanism or a coincidence.

OBJECTIVE

The objective of the investigation was to study the possible coexistence of pituitary adenoma and pheo/PGL.

DESIGN

Thirty-nine cases of sporadic or familial pheo/PGL and pituitary adenomas were investigated. Known pheo/PGL genes (SDHA-D, SDHAF2, RET, VHL, TMEM127, MAX, FH) and pituitary adenoma genes (MEN1, AIP, CDKN1B) were sequenced using next generation or Sanger sequencing. Loss of heterozygosity study and pathological studies were performed on the available tumor samples.

SETTING

The study was conducted at university hospitals.

PATIENTS

Thirty-nine patients with sporadic of familial pituitary adenoma and pheo/PGL participated in the study.

OUTCOME

Outcomes included genetic screening and clinical characteristics.

RESULTS

Eleven germline mutations (five SDHB, one SDHC, one SDHD, two VHL, and two MEN1) and four variants of unknown significance (two SDHA, one SDHB, and one SDHAF2) were identified in the studied genes in our patient cohort. Tumor tissue analysis identified LOH at the SDHB locus in three pituitary adenomas and loss of heterozygosity at the MEN1 locus in two pheochromocytomas. All the pituitary adenomas of patients affected by SDHX alterations have a unique histological feature not previously described in this context.

CONCLUSIONS

Mutations in the genes known to cause pheo/PGL can rarely be associated with pituitary adenomas, whereas mutation in a gene predisposing to pituitary adenomas (MEN1) can be associated with pheo/PGL. Our findings suggest that genetic testing should be considered in all patients or families with the constellation of pheo/PGL and a pituitary adenoma.

Glucocorticosteroids as markers of death from hypothermia

In the course of hypothermia, biochemical changes occur that are associated with stimulation of protective thermogenic mechanisms as well as mobilization of internal energy resources mediated by the hormone system. The objective of the investigation was the assessment of validity of determinations of cortisol, cortisone and corticosterone as hypothermia markers in cases of fatal hypothermia combined with concomitant insobriety of the victims. The experimental group consisted of blood samples collected in the course of medico-legal autopsies of 23 hypothermia victims. The controls included blood samples originating from 34 victims of violent sudden deaths (deaths by hanging and traffic road accidents at the scene) and from ten individuals deceased after prolonged agony in consequence of post-traumatic subdural hematomas. In both groups, three subgroups were distinguished that included cases with ethanol levels within the following ranges: 0.0-0.99, 1.0-2.99 and ≥3.0‰. The comparison of determination results showed that irrespectively of blood ethanol concentration, cortisol, cortisone and corticosterone levels seen in hypothermia victims were significantly higher as compared to the controls (P<0.001).

Usefulness of postmortem biochemistry in forensic pathology: illustrative case reports

The aim of this work is to present some practical, postmortem biochemistry applications to illustrate the usefulness of this discipline and reassert the importance of carrying out biochemical investigations as an integral part of the autopsy process. Five case reports are presented pertaining to diabetic ketoacidosis in an adult who was not known to suffer from diabetes and in presence of multiple psychotropic substances; fatal flecainide intoxication in a poor metabolizer also presenting an impaired renal function; diabetic ketoacidosis showing severe postmortem changes; primary aldosteronism presented with intracranial hemorrhage and hypothermia showing severe postmortem changes. The cases herein presented can be considered representative examples of the importance of postmortem biochemistry investigations, which may provide significant information useful in determining the cause of death in routine forensic casework or contribute to understanding the pathophysiological mechanisms involved in the death process.

Histopathological Changed of the Hypophysis in Malnutrition in Elderly Subjects

Major objectives in forensic gerontology are physical and mental disorders during aging, which can be caused by various factors involving nutrition and stress, often accompanied by dysfunction in the neuroendocrine systems including the hypophysis. The objective of the present study was to investigate the histopathological changes in the adenohypophysis in elderly subjects using autopsy materials. Hypophyses with a scaphoid shape (group S: 16 males and 4 females; mean age, 78.6 years) and a normal one (group C: 30 males and 20 females; mean age, 65.2 years) were compared. Incidence of the scaphoid-shaped hypophysis mildly increased with age, being 17% in the elderly over 65 years of age. The weight of the pituitary gland in group S (0.42 +/- 0.1 g) was lower than that of group C (0.65 +/- 0.2 g). The degree of fibrosis was higher in group S (31.6% +/- 5.4%) than in group C (18.3% +/- 6.3%). Immunohistochemical staining showed no significant differences in the proportion of the ACTH cells and the TSH cells between the two groups (p > 0.05). However, there was an increase in the proportion of gonadotrophs, prolactin cells, and S-100-containing cells in group S and a decrease in that of GH cells (p < 0.05). These findings may be associated with reduced anabolic, gonadal and hepatic functions due to malnutrition.

Postmortem serum catecholamine levels in relation to the cause of death

Catecholamines are major humoral factors and neurotransmitters that contribute to various stress responses. However, they have been considered unstable due to agony, terminal medical care and postmortem interference. The present study was a comprehensive investigation of postmortem serum levels of adrenaline (Adr), noradrenaline (Nad) and dopamine (DA) with regard to the cause of death in serial medicolegal autopsy cases (n=542) including fatalities from various traumas and diseases. There was a slight tendency toward postmortem increases of Nad and DA in cardiac blood as well as Adr and Nad in peripheral blood, a slight age-dependent decrease in Adr and DA in right heart blood, and a marked increase in serum DA due to administration during critical medical care. When these factors were taken into consideration, significantly higher cardiac blood levels were observed for Adr and Nad in injury and asphyxiation cases and for Adr in fatal methamphetamine (MA) abuse and other poisoning cases, whereas those levels were lower in fatal hypothermia. Drowning, fire fatality, acute cardiac death and cerebrovascular disease showed intermediate Adr and Nad levels. The DA level was elevated in cases of injury, hyperthermia, MA fatality and other poisoning. Topographical analyses suggested that the major sources of increased serum catecholamines in cases of injury was abdominal viscera including adrenal glands, and that in cases of asphyxiation, drowning, fire fatality, hyperthermia, MA fatality, other poisoning, acute cardiac death and cerebrovascular disease was the extremities in addition to abdominal viscera. However, there was in part a large case-to-case difference in each marker related to individual causes of death. These findings differed markedly from clinical observations and suggest that the postmortem serum catecholamine levels may reflect the magnitude of physical stress responses during the process of death in individual cases.

Effect of sodium azide on the metabolic activity of cultured fetal cells

Sodium azide is a highly toxic substance. However, the mechanism of its toxicity has not been fully established. In the present study, we attempted to investigate the toxicity of sodium azide in various cultured fetal cells, using changes in cellular respiration as an indicator of metabolic inhibition to elucidate tissue-specificity. The human fetal cell lines used in this study included myocardial cells, nerve cells, fibroblasts, hepatocytes and renal tubular epithelial cells. The cells were seeded in wells at a density of 2 x 10(6)cells/2mL, sodium azide was added at a concentration of 0.01 ng/mL to 10 microg/mL, and the respiration of each type of cell was measured 1 h later using a dissolved oxygen meter. The concentration at which sodium azide inhibited metabolic activity was lower in the nerve and myocardial cells than in the fibroblasts, hepatocytes and renal tubular epithelial cells. These findings may serve to clarify the dynamic mechanisms of sodium azide toxicity in vivo.

Age-dependent increase of clusterin in the human pituitary gland

Clusterin is a glycoprotein known to play various physiological roles including complement activity, amyloid binding activity in Alzheimer disease, as well as binding with heat shock proteins and abnormal prions. The present study immunohistochemically investigated the expression of clusterin in the human pituitary gland in subjects of 10-88 years of age (n=173). Causes of death were blunt injury (n=35), sharp injury (n=15), poisoning (n=11), drowning (n=14), fire fatalities (n=28), asphyxiation (n=15), hypothermia (n=7), hyperthermia (n=3), and natural diseases (n=45). Clusterin was detected in mixed cell follicles and the anterior lobar parenchymal cells. The area occupied by cells positive for clusterin were measured, and the ratio to the whole area of the anterior lobe (% clusterin-positive cell area) was estimated. There was a good correlation between the age of the subjects in years and the % clusterin-positive cell area in the anterior lobe of the pituitary gland (r=0.736, P<0.01). Relationships between % clusterin-positive cell and gender, cause of death, and survival time were insignificant. These findings indicate an age-dependent accumulation of clusterin in the pituitary gland, which may be related to the aging of endocrine systems.

Postmortem stability of pituitary hormones in the human adenohypophysis

The hypophysis is embedded in the fossa at the base of skull, having important functions in the hormonal system. The present study investigated its postmortem morphological changes and the stability of adenohypopyseal hormones. The pituitaries were collected at autopsy 6 h to 20 days postmortem and were studied by histology, immunohistochemistry and electron microscopy. To avoid the influence of prolonged brain hypoxia or swelling, subjects who survived not longer than 12 h were examined. Histological changes were seen in the nucleus 6 h after death, followed by cytoplasmic changes, and the cell shapes were hardly identifiable 7 days postmortem. Electron microscopy revealed evident ultra-structural changes 6 h postmortem, involving rough endoplasmic reticulum, Golgi complexes, mitochondria, nuclei and cell membranes. However, secretory granules remained well preserved 7 days postmortem. Immunostaining showed positivities for growth hormone, prolactin, adenocorticotropic hormone, luteinizing hormone and thyroid-stimulating hormone up to 15 days after death. These findings suggest the usefulness of immunohistochemical investigation of the adenohypophysis for estimating the time of death and endocrinologic evaluation in decomposed cadavers.