[Characteristics of histochemical, molecular genetic and radiation-induced liver changes depending on the postmortem interval]. / Kharakteristika gistokhimicheskikh, molekulyarno-geneticheskikh i luchevykh izmenenii pecheni v zavisimosti ot davnosti smerti.

The aim of this study is to analyze literature data on postmortem changes in the liver and their use in determination of postmortem interval. Biological death expectedly causes the development of postmortem disorders not only in the liver structure, but also changes in its biochemical and histochemical parameters. Literature data about changes of histochemical, immunohistochemical and biomolecular characteristics of liver tissue, as well as bacterial migration to the liver depending on the duration of postmortem period, are presented. The effectiveness of radiology for visualization of postmortem changes and, accordingly, for determining the postmortem interval is noted.

[Characteristics of structural morphological changes of the liver depending on the prescription of death coming]. / Kharakteristika strukturnykh morfologicheskikh izmenenii pecheni v zavisimosti ot davnosti smerti.

The purpose of the work is to analyze the literature data devoted to the study of postmortem morphological changes in liver tissue and their use to determine the prescription of death. Postmortem changes are based on the processes of postmortem redistribution of blood and autolysis, the speed and severity of development of which depends primarily on the lifetime pathology, as well as external temperature and humidity during storage of the corpse. The onset of biological death naturally entails the development of postmortem changes in the liver, manifested by a decrease in temperature, violations of the structure of organelles, cells and organ tissue as a whole. The determination and evaluation of developing postmortem morphological changes is necessary both for differential diagnosis with lifetime-developed pathological processes, and for determining the prescription of death coming. This necessitates research to study the features of the development of postmortem changes and to develop ways to assess them to determine the prescription of death coming.

[Postmortem assessment of cerebral edema]. / Posmertnaya otsenka oteka golovnogo mozga.

An analysis of literature data on the methods of post-mortem assessment of cerebral edema is presented. Based on the mechanisms of development, two main types of cerebral edema are distinguished: cytotoxic (intracellular) and vasogenic (extracellular). To determine cerebral edema, a number of methods are used, both direct and indirect, invasive and non-invasive assessment. Direct methods for assessing cerebral edema are based on determining the amount of water in its tissue. Indirect methods include morphological and radiation studies. Traditionally, the most evidence-based criteria for the diagnosis of cerebral edema are macroscopic and microscopic changes determined at autopsy. Methods are also indicated for determining the content of water in brain tissue by comparing the mass of wet and dry brain, as well as estimating the specific density of brain tissue.

The Role and Place of Thanatoradiological Studies in the Pathological Examination of Fetuses and Newborns.

Analysis of published data on the possibilities of using postmortem radiation studies in perinatology is carried out and the results of own thanatoradiological studies of the bodies of dead fetuses and newborns are presented. The possibilities of postmortem radiation studies for differential diagnosis of stillborn and deceased newborns, evaluation of the severity of maceration and the time of intrauterine fetal death, detection of pathological changes in the brain and spinal cord, respiratory and digestive organs, in the cardiovascular and urinary systems were demonstrated. It is concluded that postmortem CT has a high diagnostic efficiency in the study of the bone skeleton, free fluid accumulations in serous cavities and gas in the vessels and tissues of dead fetuses and deceased newborns. The advantage of postmortem MRI is more effective visualization of internal organs and soft tissues, which allows assessing their topography and size, as well as identifying a wide range of pathological changes. For a comprehensive objective analysis of the bodies of stillborn and deceased newborns, combined use of both imaging methods (CT and MRI) is required. At the same time, thanatoradiology should be used as a part of a comprehensive pathological study, but not as a substitute for traditional autopsy.

Morphometric Parameters of Placental Villi in Parturient Women with COVID-19.

We performed a comparative morphological analysis of placental villi in parturient women with mild and moderate COVID-19 infection. The area and perimeter of terminal villi, their capillaries, and syncytiotrophoblast were assessed on immunohistochemical preparations with antibodies to CD31 using an image analysis system; the parameters of fetal vascular component in the placental villi were also assessed. Changes in the studied parameters differed in parturient women with mild and moderate COVID-19 infection. The observed increase in the total perimeter with a simultaneous decrease in the total capillary area and the degree of vascularization of the placental villi in parturient women with COVID-19 indicates impairment of circulation in the fetal compartment and the development of placental hypoxia, which can be the cause of unfavorable neonatal outcomes.

[Technical and methodological support for postmortem radiation examinations in the pathological departments and the forensic bureau]. / Tekhnicheskoe i metodicheskoe obespechenie provedeniya posmertnykh luchevykh issledovanii v patologoanatomicheskikh otdeleniyakh i byuro sudebno-meditsinskoi ekspertizy.

The purpose of the work is to analyze the technical and methodological features of postmortem radiation studies based on literature data and the results of our own experience. To designate such studies, the term thanatoradiology has been proposed. The basis for the effective conduct of a thanatodiological examination is adequate technical support, which equally consists of the capabilities of the equipment for obtaining radiographs, CT and MR tomograms (type and generation of the device, technical features of a particular model), as well as the capabilities of the radiologist's workstation with the help of which the computer processing of the obtained images is carried out, three-dimensional reconstructions are performed, the calculation of planar and volumetric parameters and additional information is obtained. The use of an X-ray unit allows one to assess only pronounced pathology and the presence of foreign objects. The effectiveness of a computed tomography device depends on the choice of the slice thickness and the step of the examination table. Research on a magnetic resonance imager is effective at certain magnetic induction strength, the form of a magnetic coil and the used mode of recording a pulse sequence. The objectivity and efficiency of digital processing of tomograms consists of the type of a radiologist's workstation and installed programs for post-processing tomograms, including for modeling three-dimensional images and color mapping. The choice of a specific method of postmortem radiation research should be determined mainly by the research objectives. Research should be carried out taking into account age, body weight, individual characteristics and the state of body tissues. Today, it is advisable to use radiation methods as part of a comprehensive pathological and anatomical or forensic medical research to improve the quality and shorten the autopsy duration. The development of a unified protocol for postmortem CT and MRI studies that meets the pathological, anatomical and forensic requirements remains an urgent task.

Postmortem MRI Characterization of Cadaveric Hypostases in Deceased Newborns.

Using postmortem MRI, we studied the features of the development of internal cadaveric hypostasis in dead newborns. Postmortem radiological and pathoanatomical examination of 62 bodies of newborns and infants who died at the age of 1.5 h to 49 days was carried out. After the death was ascertained, prior to MRI, the bodies were stored in a refrigerator at 4°C in the supine position. Depending on the duration of the postmortem period (2-72 h), all observations were divided into eight groups. Prior to autopsy, an MRI scan was performed in T1 and T2 standard modes, followed by analysis of the presence and severity of the gradient line of the intensity of the MR signal in the liver and lung tissue in the ventral (overlying) and dorsal (underlying) areas, as well as the presence of a gradient of the intensity of the blood signal in the heart cavity and in the aortic lumen. The main manifestations of cadaveric hypostasis in the liver and lungs are changes of the MR signal intensity in the ventral and dorsal regions with the appearance of a horizontal gradient of the MR signal intensity, which reflects the location of the body after death. In the heart cavity and in the aortic lumen, there is also a gradient of the blood signal intensity of various severity with the visualization of two or three of its layers. The revealed features of the MRI signal intensity and, accordingly, the presence of its horizontal gradient depended not only on the MRI mode of the study, but also on the studied organ and the duration of the postmortem period. This should be taken into account when analyzing the results of virtopsy and determining the links of thanatogenesis of dead newborns and infants.

[Organization of postmortem radiological examination in the structure of pathological departments and forensic bureaus]. / Organizatsiya provedeniya posmertnykh luchevykh issledovanii v strukture patologo-anatomicheskikh otdelenii i byuro sudebno-meditsinskoi ekspertizy.

The purpose of this work is to develop an optimal scheme for organizing and conducting postmortem radiation studies in the Russian Federation based on literature data and our own results. One of the primary points in organizing virtopsiy is to determine the place where radiation examinations of deceased patients will be performed. The absence or presence of the equipment and capabilities available in the institution, i.e., the department of radiation diagnostics with functioning CT and MRI devices and software, determines the volume of economic costs. The analysis of the results of radiation research methods should be carried out by a highly qualified radiologist who has both general knowledge of radiation diagnostics and information about the radiation pattern of nonspecific postmortem changes. Based on our own experience in organizing postmortem radiation examinations, we consider it optimal to conduct postmortem CT and/or MRI scans by an X-ray technician in the radiation diagnostics department and to introduce a separate radiologist in the staffing of the pathology department or forensic medical examination bureau. In our opinion, an examination of the corpse by a radiologist in conjunction with a forensic expert is required to determine the most important areas of interest, tactics and methodology of radiation research. The final conclusion of the radiologist should be formed after consultation and agreement of the identified changes with a pathologist or forensic expert. Virtopsy is a highly effective objective method for examining a corpse. This dictates the need for its widespread introduction into the practice of the forensic medical examination bureaus and pathological and anatomical departments.

Postmortem Computed Tomography Angiography of Newborns.

We propose an original method of postmortem computed tomography angiography of the body of a deceased newborn. The work is based on the analysis of the results of comprehensive postmortem computed tomography and pathological examination of 30 newborns, who died from congenital malformations. The key to a full-fledged postmortem radiation study using intravascular contrasting of deceased newborns and infants is the presence of vascular catheters established during life, as well as conducting it no earlier than 12 h and no later than 48 h after death. As a contrast agent, we recommend to use an iodine-containing water-soluble radiopaque drug containing at least 250 mg of iodine per 1 ml. The volume of contrast agent is calculated based on body weight, taking into account the general edema syndrome. The introduction of a contrast agent is carried out through vascular catheters in 3 stages in various positions of the body. The analysis of tomograms and 3D-reconstruction of blood vessels using their pseudocoloring allows accurate assessment of the topography of blood vessels with the possibility of separate study of the arterial and venous vessels, and to identify both congenital abnormalities of the heart and blood vessels, and their acquired pathology. CT angiography in some cases is superior to traditional autopsy in the diagnosis of blood vessel pathology. Postmortem CT angiography should be considered as an important stage of postmortem radiology in the structure of comprehensive pathological analysis of newborns and infants.

Postmortem MRI Evaluation of Maceration Degree of Deceased Fetus.

We studied the possibilities of postmortem MRI for assessing the degree of maceration and determining the duration of intrauterine fetal death. Postmortem radiological and pathoanatomic study of the bodies of 38 stillbirths who died antenatally (main group, n=31) and intranatally (control group, n=5), who were born at gestational periods of 22-40 weeks was performed. Before the autopsy, MRI was performed in standard T1 and T2 modes. The tissue of the liver, kidney, brain, femoral muscle, lung, and skin in the hip, abdomen, and skull were studied on T1- and T2-weighted images (WI), followed by calculation of the of MR signal intensity ratio in T2- and T1-WI (SIR). The duration of intrauterine fetal death was determined based on the results of autopsy and analysis of histological preparations. It was found that the calculated values of SIR depended on the evaluated organ and the duration of intrauterine fetal death. Unfortunately, the revealed dynamics of changes in SIR does not allow unambiguous assessment of the severity of maceration processes and, accordingly, the time of fetal death due to its non-linear nature. Nevertheless, the use of SIR indicators of several organs and areas of the body makes it easier to determine the duration of intrauterine fetal death and, hence, to clarify the links of thanatogenesis of the stillborn. The advantages of post-mortem MRI compared to autopsy include non-invasive nature of the study, the possibility of archiving and subsequent multiple delayed analysis of tomograms, as well as the speed of MRI analysis, in contrast to microscopic stage of pathological examination associated with the need to prepare histological preparations.

Complex Method of CT and Morphological Examination of Placental Angioarchitechtonics.

We propose an original method of complex assessment of the placental angioarchitechtonics based on computed tomography (CT) and morphological examination. A prerequisite condition of successful examination and assessment of the placental angioarchitechtonics is the pre-preparative stage including clearing of the placental and umbilical cord vessels from blood clots by placement of placenta into 10% hypertonic NaCl solution and then on a hygroscopic substrate. The major stage of this method is injection of contrast staining mixtures into the umbilical vessels followed by CT. The concentration of radiocontrast agent in water solution of gouache should be 70% for arteries and 15% for veins. The volumes of mixtures for contrast staining should be calculated according to the weight of the placenta. The contrast staining mixture was first injected into the catheterized unpaired umbilical vein, and then into both umbilical arteries. Each injection of the contrast staining mixture was visually inspected; then branching of the stained vessel was photographed and scanned by CT. The CT scans were used to construct 3D models of placental vessels and spectral color maps, which made it possible to examine the peculiarities of placental angioarchitechtonics, to identify and evaluate anastomoses of placental vessels, and to establish the type of these anastomoses.

Potentialities of Postmortem Magnetic Resonance Imaging for Identification of Live Birth and Stillbirth.

The potentialities of postmortem MRI for differential diagnosis of stillbirth and death of a live newborn are studied. The results of MRI and pathomorphological studies of autopsy material from 20 stillborns dead at weeks 22-40 of gestation (group 1) and 19 newborns dead at the age of 2 h to 36 days (group 2) are analyzed. Control group has been formed from 7 live newborns aged 1-7 days. Postmortem MRI provides an objective quantitative evaluation of the intensity of MR signal in various tissues and regions. Calculation of the proportions of MR signal intensities in the lung tissue and environmental air and/or pleural fluid and the respiration values promotes an objective differential diagnosis of stillbirth and death of a live newborn. These data are expected to facilitate clearing out the circumstances and the direct cause of death. However, postmortem MRI cannot completely replace autopsy with complex macroscopic and microscopic studies of organs and tissues.

Possibilities of Postmortem Magnetic Resonance Imaging for Evaluation of Anasarca in Newborns.

We studied the possibilities of postmortem magnetic resonance imaging (MRI) for evaluation of anasarca in newborns. Before the autopsy, MRI in T1 and T2 standard modes was performed, signal intensity tomograms in the subcutaneous tissue were analyzed, and tissue hydration index was calculated. Using 3D reconstruction, we determined the values of hydrothorax, hydropericardium, and ascites, as well as specific volumes of fluid in the abdominal and thoracic cavities. It has been established that postmortem MRI of deceased newborns provides objective quantitative assessment of anasarca, as well as absolute and relative volumes of hydrothorax and ascites, which improves the diagnostic capacities of pathoanatomical autopsy or forensic examination of a corpse and contributes to the determination of tanatogenesis. However, postmortem MRI cannot fully replace traditional autopsy that allows conducting complex macroscopic and microscopic analysis of organs and tissues.

The Possibility of Postmortem Magnetic Resonance Imaging for the Diagnostics of Lung Hypoplasia.

We explored the possibility of using postmortem MRI for the diagnostics of lung hypoplasia associated with innate diaphragmatic hernia in neonates. The main experimental group consisted of 17 newborns with innate diaphragmatic hernia including 10 non-operated newborns and 7 newborns died after surgery for innate diaphragmatic hernia. It was demonstrated that postmortem MRI allows objective quantitative assessment of the absolute and relative dimensions of the lungs in the thoracic cavity and thereby reveals their hypoplasia, which contributes to the determination of tanatogenesis. Surgery for congenital diaphragmatic hernia leads to an increase in the mass and volume of the lungs, but does not always eliminate their hypoplasia.

[Pathological estimation of the time of fetal death]. / Patologo-anatomicheskaia otsenka davnosti vnutriutrobnoi gibeli ploda.

The paper analyzes the data available in the literature on the possibilities of determining the time of fetal death during an autopsy study. It presents gross changes in the appearance and internal organs of the fetus, as well as histological changes in the organs and placenta, which develop during maceration. The microscopic characteristics of the development of lung and kidney tissues are given in relation to the gestational age of the fetus. Changes in the mass of internal organs during maceration, as well as their standard values are indicated depending on gestational age and degree of maceration.

Conditions for Collection of Placental Tissue Samples for Culturing of Multipotent Mesenchymal Stromal Cells.

Placentas from women aged 25-32 years with normal course of gestation were studied. It is essential to stick to certain methodological approaches for preparing viable multipotent mesenchymal stromal cell culture and to carry out morphological (macro and micro) evaluation of the chorionic villi, umbilical cords, and placentas. At stage I of the study, patients' histories, labor course, and examinations of the newborns should be analyzed to exclude women with genital and extragenital diseases. At stage II, it is essential to stick to special regulations and methods for collection of specimens of the cord, amnion, and placental tissue proper. Histological control of the placental structures collected for multipotent mesenchymal stromal cell culturing is obligatory.

[Twin reversed arterial perfusion syndrome in the monochorionic diamniotic placenta with the development of an acardiac fetus]. / Sindrom obratnoi arterial'noi perfuzii v monokhorial'noi diamnioticheskoi platsente s razvitiem ploda-akardiusa.

The article describes an acardiac fetus in a patient with monochorionic diamniotic twin pregnancy with reversed arterial perfusion syndrome at 30 weeks' gestation. It gives postmortem fetal computed tomographic and pathoanatomic data. Microarray of acardiac fetal tissues revealed that there was deletion of chromosome 19 - arr [hg19] 19p13.3q11 (260,911-23,005,001) x1; size, 23 Mbp; the signal level in about 30% of fetal tissue cells containing deletion.

[Histological hanges in the placenta and vascularization of its villi in early- and late-onset preeclampsia].

AIM: to make a comparative histological study of the placenta and a morphometric analysis of its terminal villi in early- and late-onset preeclampsia. MATERIAL AND METHODS: Placentae from patients whose pregnancy had been complicated by the development of early- (n=26) or late-onset (n=84) preeclampsia were examined. A control group comprised placentae from 28 patients with physiological pregnancy and no extragenital diseases. The authors made a comparative histological study of placental tissue and a morphometric analysis of the terminal villi using the sections immunohistochemically stained for CD31. RESULTS: It was determined that there was a preponderance of branching angiogenesis in the preeclamptic chorionic villi and an increase in the number of syncytial nodules and microcysts in the septae in late-onset preeclampsia. Morphometric analysis of immunohistochemical placental specimens established a reduction in the sizes and vascularization indicators of terminal villi that determine the development of placental hypoxia and are more pronounced in cases of early-onset preeclampsia.

[Radio-visualization of non-specific postmortem changes in the cardiovascular system]. / Luchevaia vizualizatsiia nespetsificheskikh posmertnykh izmenenii serdechno-sosudistoi sistemy.

This paper presents a review of the literature concerning radio-visualization of non-specific postmortem changes in the cardiovascular system during computed tomography and magnetic resonance imaging. The peculiar radiological characteristics of postmortem blood clots and cadaveric hypostases in the internal organs are described. It is emphasized that postmortem CT and MRI can not replace the pathological anatomical studies and forensic medical autopsy. Roentgenologists engaged in the postmortem examination of the bodies must have relevant knowledge of pathological anatomy and forensic medicine (namely, they must be aware of the non-specific postmortem changes) to be able to adequately interpret the tomograms obtained and correctly establish the diagnosis. It is recommended that the postmortem CT and MRI images should be used as an additional material for the traditional autopsy, e.g. as a preliminary 'guide' preceding the postmortem examination.

[STAGING SYSTEMS OF HEPATOCELLULAR CARCINOMA].

It is the data of literature on existing classifications and systems of assessment and prognosis of hepatocellular carcinoma (HCC). In some classifications takes into account only the characteristics of the tumor tissue, in others are used biochemical and clinical characteristics in addition. Some systems allow to predict the survival of patients regardless of the stage of the disease, while others are most effective for the individual stages. The international TNM classification is generally accepted for the development of treatment methods and determining the forecast mainly for resectable HCC forms. The Japanese staging system (JIS) is mainly recommended for operable patients. Italian scale (CLIP), on the contrary, is intended to analyze HCC, which is not subject to surgical treatment. The Barcelona classification of liver cancer (BCLC) is considered the most universal, because it takes into account the stage of disease, the condition of the liver parenchyma and does not depend on the method of treatment and the patient's place of residence. Therefore, the choice of staging system and assessment of disease prognosis should be based on the clinical and morphological features of the disease, taking into account features of application of various scales.