Stillborn or liveborn? Comparing umbilical cord immunohistochemical expression of vitality markers (tryptase, alpha(1)-antichymotrypsin and CD68) by quantitative analysis and confocal laser scanning microscopy

Umbilical Cord Tissue: From Antemortem Monitoring to Postmortem Possibilities

ABSTRACT

Umbilical cord tissue (UCT) traditionally has been used as an antemortem matrix for identifying and monitoring fetal exposure to drugs suspected to have been used during pregnancy. The specimen offers several advantages as a testable tissue, including accessibility and ease of collection, ample sample volume, a long window of detection, and ability to detect for a wide range of drugs. Despite these advantages, little to no research exists on the use of UCT as a postmortem forensic toxicology specimen. This article aims to provide insights into UCT toxicological testing and infer potential applications for postmortem use, such as investigations into stillbirths and infant abandonment. Umbilical cord tissue offers several benefits as a postmortem toxicological specimen. Importantly, it can be collected with or without an autopsy being performed and may help explain factors that contribute to the underdevelopment and death of the neonate. With the limited sample volumes present in infant investigations, toxicological analysis of UCT could become a valuable tool for neonatal medicolegal death investigations.

Vitality markers in forensic investigations: a literature review

Determining whether an injury was sustained in life or not is one of the most important topics in forensic medicine. Morphological, cytological, and biological techniques are used to assess wound vitality. Several markers involved in vital and supravital reactions increase the accuracy of wound age estimation. This systematic review aimed to investigate the main vitality markers used in forensic medicine to date. This review was conducted by performing a systematic literature search on online resources (PubMed Central database and Google Scholar) until May 2022. We identified 46 articles published between 1987 and May 2022, analyzing a total of 53 markers. Based on the data of this review, the most studied vitality markers were adhesion molecules (fibronectin, p-selectin, CD 15), pro-inflammatory cytokines (IL-6, IL-1β, TNF-α), cathepsin D, tryptase, and microRNAs (miRNAs). The most interesting studies were based on animal models: the different markers were investigated through immunohistochemical and qRT-PCR methods. The experimental methods were usually based on skin incisions, ligature marks, and burned skin areas. To date, it has not been possible to identify any gold standard markers based on the criteria of efficacy, specificity, and reliability; however, studies are still in progress. In the future, the use of miRNAs is promising as well as the combination of multiple markers. In this way, it will be possible to increase the sensitivity and specificity to validate systems or models for determining wound vitality in forensic practice.

Objective evaluation of chest findings in infants by postmortem computed tomography

PURPOSE

The purpose of this study was to review the findings of computed tomography (CT) performed early postmortem on infants and to clarify the postmortem CT lung findings that occur in the absence of abnormal histopathological findings.

MATERIALS AND METHODS

From July 2016 to March 2022, 72 infants were autopsied with postmortem CT (41 boys 31 girls, aged 0-36 (mean 8.2) months). Autopsy and postmortem CT lung findings were compared with the causes of death identified by the autopsies, namely sudden infant death syndrome (n = 37), acute circulatory system disease (18), drowning (7), asphyxia (5), and dehydration/undernutrition (5).

RESULTS

The %aerated lung volume (-700 HU or less) ranged from 0 % to 33 % (mean 1.5 %, median 0 %), being <1 % in 61 cases (84.7 %) and >3 % in 3/5 (60 %) of the dehydration/undernutrition group. The dehydration/undernutrition group showed significant preservation of lung field air content compared with the other causes of death groups (p < 0.05). Receiver characteristic curve analysis showed a cut off value of 0.8 % and area under the curve of 0.88806. The drowning group had significantly greater pleural cavity fluid retention than the other causes of death groups (p < 0.05). No correlation was found between postmortem interval and pleural cavity fluid retention. However, resuscitation time and pleural cavity fluid retention were correlated.

CONCLUSION

Evaluation of CT values on postmortem lung fields of infants usually reveals a marked decrease in air content. When air content exceeds 0.8% on infant postmortem CT, dehydration/undernutrition should be considered in the differential diagnosis.

State-of-the-Art on Wound Vitality Evaluation: A Systematic Review

The vitality demonstration refers to determining if an injury has been caused ante- or post-mortem, while wound age means to evaluate how long a subject has survived after the infliction of an injury. Histology alone is not enough to prove the vitality of a lesion. Recently, immunohistochemistry, biochemistry, and molecular biology have been introduced in the field of lesions vitality and age demonstration. The study was conducted according to the preferred reporting items for systematic review (PRISMA) protocol. The search terms were "wound", "lesion", "vitality", "evaluation", "immunohistochemistry", "proteins", "electrolytes", "mRNAs", and "miRNAs" in the title, abstract, and keywords. This evaluation left 137 scientific papers. This review aimed to collect all the knowledge on vital wound demonstration and provide a temporal distribution of the methods currently available, in order to determine the age of lesions, thus helping forensic pathologists in finding a way through the tangled jungle of wound vitality evaluation.

"Was the Infant Born Alive?" A Review of Postmortem Techniques Used to Determine Live Birth In Cases of Suspected Neonaticide

The question of whether an infant was born alive has received much attention in the forensic literature. The volume of literature reflects the degree of controversy surrounding the techniques employed and their varied interpretation and utility. The majority of the investigation has been focused on the question "Has the infant breathed?" to determine if an infant was born alive by utilizing techniques that assess aeration of the lungs. However, caution must be employed when interpreting these techniques due to the well-recognized limitations in their interpretation, particularly in the presence of gaseous decomposition and/or resuscitation efforts. Although in some instances there may be irrefutable evidence that the infant was born alive, there is no single finding that can reliably be utilized to answer the question "Was the infant born alive?" in every case. Hence, the approach to postmortem investigation continues to include a wide range of observations, dissections, special techniques, and ancillary tests to assist the pathologist to form a considered opinion. There are a number of more recently described techniques which show great promise in assisting to answer this question including advanced imaging and immunohistochemical studies of the umbilical cord. It remains, though, that in many cases it is not possible to definitively answer this question and stillbirth should be assumed due to the potential legal implications of determining that an infant was born alive.

Forensic Aspects of Perinatal Deaths

From a forensic pathologist's perspective, there are several aspects of the perinatal postmortem that are particularly important. If a fetus is found abandoned, the pathologist needs to ascertain the fetal age, the appropriateness of growth, if the baby was born alive or dead, and the possible causes of death. In cases of litigation for perinatal deaths occurring in hospitals, access to the obstetric and neonatal notes (if the baby is born alive and dies a few hours or days later) is fundamental to reach a correct interpretation and conclusion. The most important points to consider in cases of intrapartum death are the roles of asphyxia and trauma in the causation of the baby's death. Timing of the fetal death in relation to delivery may also be an important point in these cases. Finally, intrapartum lesions should always be considered in the differential diagnosis of possible child abuse in babies aged two months or less.