Rib fractures prediction method for kinetic energy projectile impact: from blunt ballistic experiments on SEBS gel to impact modeling on a human torso FE model.

The present paper aims to assess the risk of rib fractures caused by any rigid less-lethal kinetic energy projectiles. To that end, a coupled experimental and numerical approach is proposed to relate ballistic experiments with the risk of blunt trauma. A polymer gel block is employed as ballistic testing medium to interpret ballistic impacts through the measurement of the dynamic gel wall displacement. Moreover, a biofidelic 50th percentile human torso finite element model created in the code Hypermesh (Altair HyperWorks ©) is used to replicate experiments and real world accidents. Then, the probability curve of rib fractures is a function of the viscous criterion and derives from a study on human cadaver mid-sternum available in the literature. Twelve impact conditions of rigid projectiles are applied to a SEBS gel block and are replicated on the human torso model mid-sternum. A statistical analysis is performed by virtue of a Spearman's correlation matrix in order to identify relations between experimental measurements and the viscous criterion evaluated numerically. The determination of both statistical significances and correlation coefficients results in several strong correlations between experimental measurements and the viscous criterion evaluated numerically. These relations imply the establishment of transfer functions between experimental metrics on the gel block (the maximum gel wall displacement and a gel wall displacement - rate of displacement based metric) and the probability of rib fractures. Finally, these correlations constitute a primary and an up-and-coming predicting tool for the risk of rib fractures.

Case report: recovery of Calliphora vicina first-instar larvae from a human traumatic wound associated with a progressive necrotizing bacterial infection.

Human myiasis caused by Calliphora vicina is rare in Europe. Here we report a case of C. vicina infection occurring in the traumatic leg wound of a healthy 21-year-old man. Firstly, a progressive necrotizing infection developed in the wound despite administration of antibiotics. Aeromonas hydrophila was isolated from the wound samples. Secondly, during debridement, C. vicina first-instar larvae were isolated from the wound. To our knowledge, this is the first European case of C. vicina wound myiasis associated with severe A. hydrophila infection.

Morphine extraction in necrophagous insects remains for determining ante-mortem opiate intoxication.

To study the potential use of insects remains as toxicological indicators, we measured morphine in desiccated entomological materials using a radioimmunoassay method (Coat-A-Count Serum Morphine, Dade Behring, France) following enzymatic hydrolysis.First, enzymatic cuticle extraction of morphine (pronase digestion preceded by a 2h incubation with a dithiothreitol solution) was performed on various substrates (Calliphoridae puparial cases and desiccated adults, and desiccated pupae of Dermestidae) which were then tested to identify possible interferences with the radioimmunoassay procedure. This same procedure was performed on puparial cases and desiccated adults of Lucilia sericata (Diptera, Calliphoridae) previously reared on minced meat containing various morphine concentrations. Morphine was detected only in cuticle powder from insects reared on meats containing 100 and 1000mg/kg. Higher concentrations were measured in puparial cases. Rearings on psoas from eight heroin overdose victims confirmed previous experimental results. Remains of necrophagous insects, particularly puparial cases, are often preserved for a long time, and consequently can serve as late alternative specimens for toxicological analysis when suitable tissues are not available.

Determination of drug levels in two species of necrophagous Coleoptera reared on substrates containing morphine.

Two species of necrophagous Coleoptera: Dermestes frischi (Dermestidae) and Thanatophilus sinuatus (Silphidae), were reared on substrates containing different amounts of morphine. Colonies of D. frischi were reared on rabbit carcasses which had been given 10, 20, and 40 mg/h of morphine hydrochloride via ear artery perfusion over a 3 h period prior to death. A fourth rabbit served as a control. T. sinuatus was reared on minced beef spiked with morphine hydrochloride to give concentrations of 1,000, 2,500, 5,000, and 10,000 ng/g and one control colony. These dosages were calculated to create tissue concentrations of morphine similar to those encountered in human deaths due to morphine overdose. Larvae. pupae, and adults (except for T. sinuatus) were analyzed for morphine content. All developmental stages of D. frischi were positive for morphine and concentrations correlated with cadaveric tissue concentrations during larval stages and to a lesser extent in the adult stage. For T. sinuatus, the best correlations were found in 2nd and 3rd instar larvae. This study demonstrates the potential for use of necrophagous Coleoptera, as well as Diptera larvae, as alternate specimens for toxicological analyses.

Immunohistochemical contribution to the study of morphine metabolism in Calliphoridae larvae and implications in forensic entomotoxicology.

Morphine was detected by immunohistochemistry on sections of third stage larvae of Calliphora vomitoria (Diptera, Calliphoridae) reared on minced beef meat previously treated with morphine hydrochloride. The detection was performed with an avidin-biotin-peroxidase-complex method. Positive specimens showed specific staining of the haemolymph and a more intense immunoreaction in an area located at the limit between exocuticle and endocuticle. These results constitute an evidence of morphine accumulation inside the cuticle of Diptera larvae during their development. During the pupariation, the larval cuticle is transformed into the sclerotized puparium. This study consequently points out the possibilities of analyzing empty pupariae when suitable tissues or living necrophagous insects are absent.

Determination of drug levels in larvae of Protophormia terraenovae and Calliphora vicina (Diptera: Calliphoridae) reared on rabbit carcasses containing morphine.

Two species of blow flies (Diptera: Calliphoridae) were reared on tissues from rabbits administered different dosages of morphine. These species, Protophormia terraenovae and Calliphora vicina are among the first wave of insects colonizing a dead body. Two series of 3 rabbits were given dosages of 10, 20, and 40 mg/h of morphine over a 3 h period via ear artery perfusion. A morphine blood level plateau was attained after 1 h of perfusion. Two other rabbits were used as controls. Samples of tissues collected from rabbits using a coelioscopic technique were determined to have morphine concentrations similar to those encountered in human overdoses and were correlated with dosages of morphine administered. All samples from control rabbits were negative for morphine. Larvae and puparia of both species were regularly collected from each rabbit for toxicological analysis. Concentrations of morphine in larvae reared on rabbit carcasses containing morphine were significantly lower than concentrations found in the tissues. There was a decrease in concentration in morphine observed in transition from feeding 3rd instar larva to puparium. A correlation between larval concentration and tissue concentration was found only in feeding 3rd instar larvae.

[Human nasal myiasis due to Oestrus ovis]. / Myiase nasale humaine à Oestrus ovis.

One case of human nasal myiasis caused by second and third instar larvae of Oestrus ovis was observed in Lille (North France). Oestrosis is a common myiasis of sheep and goats in Mediterranean and Tropical countries. The authors examine the oestrosis pathogenesis in the usual host (sheep) or in humans, and analyse the epidemiology, the symptomatology and the treatment of human oestrosis.

Necrophilous insect succession on rabbit carrion in sand dune habitats in northern France.

Six freshly killed rabbit carcasses were exposed in different habitats in the coastal dune massif of Ambleteuse (northern France) during the spring seasons of 1996 and 1997. In total, 66 arthropod species were collected during the decomposition of these carcasses, and particular attention was paid to taxa of necrophilic significance. The pattern of insect activity was recorded and is discussed in relation to meteorological conditions. One significant feature in this study was the delay in initial oviposition by flies during 1996, which demonstrates the need for caution in estimation of postmortem interval by entomological techniques in early spring. Although daily temperatures may be favorable for adult fly activity, flies may be absent because of small population size and low nocturnal temperatures during this period.

Morphine perfused rabbits: a tool for experiments in forensic entomotoxicology.

In order to establish an animal model for entomotoxicological studies, the kinetics of morphine elimination from blood after a single intravenous injection of morphine and the concentration of morphine in tissues following a continuous perfusion were studied. The aim of these experiments was to obtain controlled morphine tissue concentrations similar to those encountered in fatal human heroin overdoses. These tissues can be used as a food source for developing fly larvae in entomotoxicological studies. In the single injection experiment, seven rabbits were administered 1 or 2 mg/kg body weight of morphine chlorhydrate via the main ear artery. Blood samples of 200 microL were removed regularly via a catheter. Morphine concentration was determined using RIA techniques. Morphine was found to be first rapidly distributed and then slowly eliminated, following a two-exponential equation. Elimination of morphine from blood can be described as a two-compartment model. Constants of the equation were determined using the Kaleidagraph program. Using those constants, the main pharmacokinetics parameters were calculated. Results of these parameters showed the following: clearance from 13.3 to 16.2 L.h.1, half-life of the distribution phase from 0.6 to 0.9 min, and half-life of the elimination phase from 21 to 26 min. These results were used to calculate the rate of perfusion of morphine for rabbits to obtain desired, controlled, and constant concentrations of morphine in tissues. In the second experiment, three rabbits received a perfusion of morphine intravascularly at a rate of 2 mg/kg/h for a period of 3 h. These rabbits were sacrificed and analyses performed on several abdominal and thoracic organs. Results showed that the concentrations of morphine differed according to the organ analyzed, but were reproducible for organs between animals. These concentrations were similar to those normally encountered in cases of human death due to heroin overdoses.

Determination of drug levels in larvae of Lucilia sericata (Diptera: Calliphoridae) reared on rabbit carcasses containing morphine.

This study concerns the determination of morphine concentrations in fly larvae reared on rabbits administered different concentrations of morphine and a correlation between concentrations of the drug in larvae and tissues. Three rabbits (R1, R2 and R3) were given dosages of 12.5, 25.0 and 50.0 mg/h of morphine over a 3 h period via continuous ear artery perfusion. These dosages and time of perfusion were calculated to create tissue concentrations of morphine similar to those encountered in human death due to overdose. Morphine blood level plateau was attained after 1 h of perfusion. A fourth rabbit was used as a control. To evaluate drug concentrations, tissues were sampled using a coelioscopic technique. Approximately 400 eggs of Lucilia sericata, all of the same age category, were placed in eyes, nostrils and mouth of each rabbit carcass. Larvae and puparia were regularly collected from each rabbit for toxicological analysis. The concentrations of the drug in the tissues sampled were determined to be similar to those normally encountered in human overdoses and were correlated with the dosage of morphine that had been administered. Morphine was detected in all larvae and pupae fed on tissues from carcasses administered morphine, except for puparia from the colony fed on the R1 animal which received 12.5 mg/h dosage of morphine. All samples from the control rabbit were negative for morphine. Concentrations of morphine in larvae reared on rabbit carcasses containing morphine were 30 to 100 times lower than the concentrations found in the tissues. A correlation between the tissue concentrations and larval concentrations was found in only 3rd instar larvae (80 to 140 h following hatching). No correlations were found between administered dosages, tissue concentrations and younger larvae, prepuparial larvae or puparia.

Effects of morphine in decomposing bodies on the development of Lucilia sericata (Diptera: Calliphoridae).

This study concerns the effects of morphine in tissues on the rate of development of Lucilia sericata (Diptera: Calliphoridae) using those tissues as a food source. Lucilia sericata is a species of fly commonly found on human corpses in Europe during the early stages of decomposition and thus of forensic interest. Three rabbits were administered 12.5, 25.0 and 50.0 mg/h of morphine chlorhydrate via ear perfusion over a period of 3 h. These dosages and duration of perfusion were calculated to give tissue concentrations of morphine similar to those encountered in fatal human overdoses. A fourth rabbit was used as a control. Following administration of the drug, rabbits were sacrificed and 400 eggs of Lucilia sericata, all of the same age, were placed in the eyes, nostrils and mouth of each rabbit. Developing larvae were sampled daily to determine growth rate and weight. Puparia and emerging adult flies were also sampled. Data were analyzed using analysis of variance (ANOVA) and Student's T-test. Results of this study show that an underestimation of the postmortem interval of 24 h is possible if the presence of morphine in tissues is not considered. This study demonstrates again the necessity of considering the possible effects of drugs in tissues on insect growth rates when estimating the postmortem interval using entomological techniques.

Endocytosis and binding of asialoorosomucoid by hepatocytes from rats with jejunoileal bypass.

Rats with jejunoileal bypass were used to study the biological activity of the hepatic binding protein. Hepatocytes were prepared 11 weeks after surgical procedure, and presence of asialoorosomucoid in serum has been determined. Compared to control rat hepatocytes, endocytosis of [3H]asialoorosomucoid by bypassed rat hepatocytes was decreased by about 60%. This was due to a decreased number of total and surface receptors. In most sera, an accumulation of asialoorosomucoid was found. A reduction of protein synthesis or turnover could be considered.

Circulating LH, FSH, prolactin, testosterone, delta 4-androstenedione, dehydroepiandrosterone sulfate and cortisol levels in the fetus in late gestation and in newborn male and female lambs.

Gonadotropins, prolactin (PRL), testosterone (T), delta 4-androstenedione, dehydroepiandrosterone sulfate and cortisol (F) levels were determined from 14 days before birth to term in 3 female and 3 male ovine fetuses with a chronically implanted venous catheter, and in the same animals from birth to 72 h of age. In both sexes, plasma gonadotropins and androgens were low throughout the period of study while plasma F increased with gestational age. After birth, plasma gonadotropins and PRL tended to increase progressively with time while PRL concentrations were significantly higher in female than in male lambs. F and T concentrations decreased significantly within the first 12 and 6 h of postnatal life. Higher T values were again observed at 36 h in male lambs. These data indicate that the fetal hypothalamic-pituitary-gonadal axis is relatively quiescent in the last 14 days of gestation but is activated within the first 72 h after birth.

Perinatal activity of the hypothalamic-pituitary-gonadal axis in the lamb. II. In vitro testicular response to human chorionic gonadotropin and choleratoxin in the first 2 months of life.

Testicular response to human chorionic gonadotropin (hCG) was studied in male lambs. Adenosine 3':5'-cyclic monophosphate (cAMP), testosterone (T), delta 4-androstenedione and 17 alpha-hydroxyprogesterone content and cAMP and T production by dispersed interstitial cells were assessed in control and hCG-pretreated animals. Plasma T levels increased after hCG at 1, 4 and 8 weeks. Increments in the testicular content of cAMP, delta 4-androstenedione, and T were greater at 8 weeks and that of 17 alpha-hydroxyprogesterone and 125I-hCG binding to dispersed interstitial cells were identical at all ages. cAMP and T production by dispersed interstitial cells from nonstimulated animals and the response to hCG and choleratoxin were similar in all lambs. In contrast, cAMP and T production were higher at 1 week only in animals pretreated with hCG in vivo. These data are compatible with hCG-induced desensitization at 4 and 8 weeks.