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Biomedical subjects

F Introna

Publications and source records attributed to F Introna.

At least 19 recordsLinked to original sources

Factors affecting decomposition and Diptera colonization.

Understanding the process of corpse decomposition is basic to establishing the postmortem interval (PMI) in any death investigation even using insect evidence. The sequence of postmortem changes in soft tissues usually gives an idea of how long an individual has been dead. However, modification of the decomposition process can considerably alter the estimate of the time of death. A body after death is sometimes subject to depredation by various types of animals among which insects can have a predominant role in the breakdown of the corpse thus, accelerating the decomposition rate. The interference of the insect community in the decomposition process has been investigated by several experimental studies using animal models and very few contributions directly on cadavers. Several of the most frequent factors affecting PMI estimates such as temperature, burial depth and access of the body to insects are fully reviewed. On account of their activity and world wide distribution, Diptera are the insects of greatest forensic interest. The knowledge of factors inhibiting or favouring colonization and Diptera development is a necessary pre-requisite for estimating the PMI using entomological data.

Animals↗

Entomotoxicology.

Entomotoxicology is a relatively new branch of forensic entomology. The potential use of insects for detecting drugs and other toxins in decomposing tissues has been widely demonstrated. In death investigations, Diptera and other arthropods can be reliable alternate specimens for toxicological analyses in the absence of tissues and fluids normally taken for such purposes. Entomotoxicology also investigates the effects caused by drugs and toxins on arthropod development in order to assist the forensic postmortem interval estimates. However, several remarks on the limitations of entomotoxicology have been highlighted recently. In this paper, the implications for the practice of this forensic procedure are fully reviewed.

Adult↗

The forensic entomologist in the context of the forensic pathologist's role.

An adequate death investigation requires the combined efforts and cooperation of experts in different disciplines: crime scene technicians, death investigators, forensic pathologists, anthropologists, entomologists, other medical and non-medical professionals. These front-line experts play a crucial role in every death investigation process. The forensic pathologist normally has the legal authority to take charge of the dead body at a death scene and his primary functions are the exterior and interior examination of the cadaver by analyzing the extent of antemortem injuries and the postmortem changes and the recovery of physical evidence. He is responsible for determining how, when and why of any death which is the result of violence, suspicious or unexplained circumstances or a death which is sudden or unattended, defending and explaining the reasons for making these diagnoses in a courtroom. The forensic entomologist can provide invaluable aid in death cases where human remains are colonized by insects and in the overall investigation. His principal role is to identify the arthropods associated with such cases and to analyze entomological data for interpreting insect evidence. He is responsible for determining the period of insect activity according to all the variables affecting insect invasion of remains and their development. The major goal of medico-criminal entomology is to contribute to the determination of the time, cause, manner and place of the investigated death (especially on badly decomposed corpses or skeletonized human remains) with the support of all the elements which can be inferred from the study of insects found on the cadaver or nearby. The application of techniques devised recently in forensic entomology can allow experts in the field to collect strong entomological evidence and provide useful information not only in a death investigation including movement or storage of the remains following death, time of dismemberment, postmortem artifacts on the body but also at the scene, and even more in child neglect, sexual molestation and identification of suspects. As the role of the forensic entomologist at the death scene, at the autopsy and in the laboratory is defined and well known, this paper focuses on the difficulties that could arise if forensic pathologists and entomologists are uncertain about the procedures that they have to follow, do not realize the value of objective findings or fail to evaluate them. Although every forensic case presents a slightly different set of circumstances and has to be tackled individually, the forensic pathologist should work with the forensic entomologist from the visual observations of the cadaver on the scene, through the collection of arthropods and temperature data at the death scene and at the autopsy, up to the final report with the interpretation of entomological and other biological evidence.

Animals↗

Human and insect mitochondrial DNA analysis from maggots.

During the course of our forensic investigations, we have encountered situations where it would have been useful to have evidence, other than direct contact between the two, for concluding that a carrion-fly maggot developed on a particular human victim. If a maggot collected during a death investigation did not develop on the victim, then its age is not relevant to estimating the postmortem interval. In this study we demonstrate that mitochondrial DNA (mtDNA) sequence data can be obtained from the dissected gut of a maggot that had fed on human tissue. These data can be used to identify both the human corpse upon which the maggot had been feeding and the species of the maggot itself.

Animals↗

Determination of postmortem interval from old skeletal remains by image analysis of luminol test results.

The luminol test is routinely used in forensic serology to locate blood traces and identify blood stains not visible to the naked eye; its sensitivity is reported as ranging from 1:100,000 to 1:5,000,000. To evaluate the possibility of correlating the postmortem interval with blood remnants in bone tissue, the luminol test was performed on 80 femurs with a known time of death, grouped in five classes. Powdered bone (30 mg) was recovered from compact tissue of the mid-shaft of each femur and was treated with 0.1 mL of Luminol solution (Sirchie Finger Print Laboratories, Inc.). The reactions were observed in a dark room and filmed by a TV camera equipped with a recording tape. An intense chemiluminescence was observed after a few seconds in all 20 femurs with a PMI ranging from 1 month to 3 years. On the 20 femurs with a PMI ranging from 10-15 years, a clear chemiluminescence was visible with the naked eye in 80% of the sample. Among the 20 femurs with a PMI ranging from 25 to 35 years, a weaker chemiluminescence appeared in 7 femurs (33% of the sample). In the 10 femurs with a PMI ranging from 50 to 60 years, a faint reaction was observed only in a single femur. In none of the ten femurs with a PMI over 80 years was chemiluminescence observed. The image of each reaction was computerized and analyzed for gray scale. The results of image analysis show a possible quantitative relationship between the PMI and luminol chemiluminescence in powdered bone.

Bone and Bones↗

Sex determination by discriminant analysis of patella measurements.

The authors have analyzed 80 skeletons (40 males and 40 females) from the collection at the Institute of Legal Medicine of the University of Bari belonging to a known contemporary Southern Italian population; time of death was around 1970 and ages ranged from 25 to 80 years. Seven measurements taken on 80 intact, undeformed right patellae (max height, max width, thickness, height and width of the external facies articularis, height and width of the internal facies articularis) were used to determine sex by multivariate discriminant analysis. One function associating two parameters (max width and thickness) obtained the highest value of correct sex determination with a rate of 83.3%; other functions showed a higher percentage of misclassification (up to 17.5%). This study tests the success rate of correct sex prediction based exclusively on patellar dimensions. The discriminant factors carried out by statistical analysis may aid the forensic anthropologist when no other human skeletal remains suitable for sex determination are available.

Adult↗

Three case studies in forensic entomology from southern Italy.

Three cases of forensic interest regarding the estimation of postmortem interval (PMI) by entomological data are presented. The three cases concerning criminal investigations were performed in Southern Italy by the Entomological Laboratory of the Institute of Forensic Medicine at the University of Bari. For each case the authors present a detailed description of the remains as observed at the crime scene and a description of the arthropods collected from the remains. The PMI estimation was based on comparison of data from autopsy reports (rate of decay), local environmental conditions (temperature, humidity, rainfall) and development times for the immature stages of each species of local arthropod and succession patterns. The collection of insects was performed at the discovery site and during autopsy procedures. In the first case a PMI of 5 to 8 days was established based on the presence of adult specimens of Saprinus aeneus (family Histeridae), and mature larvae of Chrysomya albiceps and Sarcophaga carnaria (3rd instar). In the second case, on the charred remains of a corpse, larvae of Sarcophaga haemorrhoidalis (3rd instar) and Protophormia terraenovae (2nd instar) were observed in different developmental stages, as indicated, giving a PMI of 3 to 4 days based on entomological data. In the third case a PMI of 36 to 48 hours was defined from the evidence of Calliphora vicina 2nd instar on the two burnt bodies. In all cases the entomological evidence alone led to conclusions on PMI.

Adult↗

Sex determination by discriminant analysis of calcanei measurements.

Eight measurements taken on the right calcaneus (maximum length, load arm width, minimum width, height of calcaneus, body height, breadth of the facies articularis talaris posterior, breadth and height of the facies articularis cuboidea) of a known contemporary Southern Italian skeletal population (40 males and 40 females) were used to determine sex by multivariate discriminant analysis. Three functions revealed a correct sex-determination of 85%. These functions were obtained by the association of the following parameters: maximum length, load arm width and breadth of the facies art. talaris post. (function no. 1); maximum length and breadth of the facies art. talaris post. (function no. 2); maximum length and height of the facies art. cuboidea and breadth of the facies art. cuboidea (function no. 3). These results may aid the forensic anthropologist when no other remains, useful for skeletal sex determination, are available.

Adult↗

Skeletal sex determination by scapular measurements.

Measurements of seven scapular parameters (max. length, max. breadth, max. distance acromion-coracoid, max. length of acromion, max. length of coracoid, length and breadth of glenoid cavity), taken from a known contemporary Italian (Apulian) skeletal population were analyzed to obtain sex determination by discriminant analysis. In the univariate analysis, the maximum scapular breadth shows the best discriminant attitude with lowest percentage of misclassification (8.75%). In the multivariate discriminant analysis it's possible to have a 95% correct sex determination using only three parameters (max. distance acromion-coracoid, maximum length of coracoid and length of glenoid cavity). The association of two measurements of glenoid cavity allows the determination of skeletal sex with 10% misclassification rate. The application of these measurements can therefore be considered quite useful in forensic investigation when just fragmented scapular remains are recovered.

Acromion↗

[Determination of height in life using multiple regression of skull parameters].

The Authors have evaluated the possible correlations between cranial diameters and height in a population of 358 young males aged between 17 to 27 years old. The maximum anterior-posterior and lateral cranial diameters were measured along with stature. Then, the data was correlated using the SAS Program (Stepwise method) to obtain a multiple linear regression between height (dependent variable) and the cranial diameters (independent variable). Secondly, the Authors also studied the probable correlation between height and cranial diameters obtained without including the thickness of the soft tissues. In conclusion, they proposed a mathematical formula, applicable in forensic investigation, regarding the determination of the actual living stature of subjects for whom skills are the only skeletal remains available for identification procedures.

Adolescent↗

[Sexual dimorphism of deciduous teeth in medico-legal identification].

Sexual identification of immature skeletal remains is still a difficult problem to solve in Forensic Anthropology. For this reason we have attempted to use sexual dimorphism of deciduous teeth. Mesial-distal and vestibular-palatal crown diameters of maxillary deciduous molars were obtained from 80 (40 male, 40 female) Apulian (southern Italian) children with age included from 3 to 11. In addition, for each tooth, three dental indexes were calculated from crown measurements. Data, so obtained, were separately analyzed using discriminant functions. The results revealed that the combinations of crown diameters were not able to give significant functions for "sexing" immature skeletal remains. Only specific combinations of dental indexes gave significant results. The best function, obtained by the association of crown index of 54, 55, 65 and crown module of 64, allow correct sex determination of prepuberal human skeleton with a misclassification of 20%.

Child↗

[Determination of height from tibia fragments].

In a study involving the skeletal identification of stature, the Authors have performed multiple regression analysis between the measurements taken from 80 tibias (40 male and 40 female) and the living stature of the subjects to whom the tibias belonged to in life. The goal was to allow the forensic investigator to estimate the living stature by integral tibias or fragments just using association or single tibial measurements. The regression equations obtained allow to estimate living stature from different associations of well defined segments of tibia. This is a useful aid in forensic investigations, where it may be necessary to ascertain the individual's height during his/her life from isolated fragmented or mixed skeletal remains.

Adult↗

[Determination of skeletal sex using discriminant analysis of ulnar measurements].

Twelve ulnar measurements take on a series of 80 skeletons (40 male, 40 female) of a known Southern Italian population have been used in 9 combinations to produce discriminant functions for skeletal sex determination. The highest percentage of correct sex classification (95%) was obtained by the association of the minimum circumference and the maximal length. Using other four discriminant functions sex is correctly identified in 93.75% of the sample; in addition two of these functions, obtained by the associations of: minimum circumference and distal epiphyseal breadth, height of proximal articular surface, superior breadth and corio-olecranic distance, allowed to have a sex determination even by fragmented ulnae. For each discriminant function proposed, coefficients of discrimination, section points, male and female centroid and the percentage of misclassification are reported. Practical applications of this method will be certainly of aid in sexual identification in case of forensic interest.

Adult↗

Clinical spectrum of accidental hemlock poisoning: neurotoxic manifestations, rhabdomyolysis and acute tubular necrosis.

In the past, hemlock poisoning was only known for its neurotoxic effects; quite recently non-neurological features, consisting of rhabdomyolysis and acute renal failure, have been also described. Here we report our experience with these clinical findings, which we frequently observe in accidental hemlock poisoning. Between 1972 and 1990 we studied 18 patients: 17 of them were poisoned by conline (an alkaloid of Conium maculatim) in Apulia (Italy), and one by cicutoxin (the active principle of water hemlock) in New Mexico (USA). In the non-rapidly-fatal cases we tested myoglobinuria, serum muscle enzymes, and renal function. In the patients with acute renal failure we performed microscopical examination of kidney specimens; immunohistochemistry was carried out to identify myoglobin and actin in tubules. Coniine was detected in urine, serum, or tissues. Neurological features were present in all of our cases: coniine had a curare-like effect on the neuromuscular junction, whereas cicutoxin was convulsant on the central nervous system. In addition rhabdomyolysis was noted in the 17 subjects poisoned by coniine. Acute renal failure was observed in five patients; it was confirmed by histological evidence of tubular necrosis with intratubular deposition of myoglobin and actin released by rhabdomyolysis. Our cases seem to be the first with histopathologically proven acute tubular necrosis in coniine intoxication. In conclusion, in hemlock poisoning neurotoxic manifestations may be accompanied by rhabdomyolysis and acute tubular necrosis; increased awareness of these clinical features is recommended in order to improve the diagnostic and therapeutic procedure.

Adult↗

Sarcosaprophagous fly activity in Maryland.

Eighty-six successful rearings of sarcosaprophagous flies characteristic of the first successional insect wave of infestation of a corpse were conducted under field conditions in Maryland. Different species were observed to be active during spring and summer. The development times for the immature stages of each species, with the related temperatures at which the development occurred are reported for both seasons studied.

Animals↗

Opiate analysis in cadaveric blowfly larvae as an indicator of narcotic intoxication.

Specimens of liver were collected from 40 cases in which the cause of death had been determined to be opiate intoxication. Rearings of Calliphora vicina larvae were then promoted on the decomposing liver. A control group of 10 decomposed liver specimens from non-opiate deaths was treated similarly. Analysis of larvae and liver for opiates (morphine) was conducted by radioimmunoassay. Good qualitative and quantitative correlation was observed in both the positive and negative groups. Regression analysis comparing the concentrations of opiates found in the larvae with those found in the liver in the positive group resulted in a correlation of r = 0.790.

Animals↗

Suicide from multiple gunshot wounds.

Nine cases of multiple-shot suicides (suicides involving more than two gunshot wounds) examined in the last 6 years at the Office of the Chief Medical Examiner. State of Maryland, are reported. All victims, with the exception of one, were white: three were women and six were men, with ages ranging from 22 to 81 years. For each case, the results of the scene investigation, the ammunition used, and the autopsy and toxicological findings are described. Each victim suffered 3-5 gunshot wounds. The most common site for the gunshot wounds of entrance was the precordial region, followed by the left chest, the head, and the abdomen. Gunshot wounds were rarely localized exclusively to the head, whereas gunshot wounds scattered on different classic suicide body sites or all confined to the precordial region and the left chest were common. A distinction between instantaneously lethal targets, rapidly lethal targets, and targets of secondary importance is provided, and the guidelines for the proper determination of a multiple-shot suicide are presented.

Abdominal Injuries↗