Investigation of metabolites for estimating blood deposition time.

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Investigation of metabolites for estimating blood deposition time.

Int J Legal Med. 2017 Aug 05;:

Authors: Lech K, Liu F, Davies SK, Ackermann K, Ang JE, Middleton B, Revell VL, Raynaud FJ, Hoveijn I, Hut RA, Skene DJ, Kayser M

Abstract
Trace deposition timing reflects a novel concept in forensic molecular biology involving the use of rhythmic biomarkers for estimating the time within a 24-h day/night cycle a human biological sample was left at the crime scene, which in principle allows verifying a sample donor’s alibi. Previously, we introduced two circadian hormones for trace deposition timing and recently demonstrated that messenger RNA (mRNA) biomarkers significantly improve time prediction accuracy. Here, we investigate the suitability of metabolites measured using a targeted metabolomics approach, for trace deposition timing. Analysis of 171 plasma metabolites collected around the clock at 2-h intervals for 36 h from 12 male participants under controlled laboratory conditions identified 56 metabolites showing statistically significant oscillations, with peak times falling into three day/night time categories: morning/noon, afternoon/evening and night/early morning. Time prediction modelling identified 10 independently contributing metabolite biomarkers, which together achieved prediction accuracies expressed as AUC of 0.81, 0.86 and 0.90 for these three time categories respectively. Combining metabolites with previously established hormone and mRNA biomarkers in time prediction modelling resulted in an improved prediction accuracy reaching AUCs of 0.85, 0.89 and 0.96 respectively. The additional impact of metabolite biomarkers, however, was rather minor as the previously established model with melatonin, cortisol and three mRNA biomarkers achieved AUC values of 0.88, 0.88 and 0.95 for the same three time categories respectively. Nevertheless, the selected metabolites could become practically useful in scenarios where RNA marker information is unavailable such as due to RNA degradation. This is the first metabolomics study investigating circulating metabolites for trace deposition timing, and more work is needed to fully establish their usefulness for this forensic purpose.

PMID: 28780758 [PubMed – as supplied by publisher]

SN 623: Inching Forward

This week we discuss and look into DigiCert’s acquisition of Symantec’s certificate authority business unit, LogMeIn’s LastPass Premium price hike, the troubling case of Marcus Hutchins’ post-Defcon arrest, another instance of WannaCry-style SMBv1 propagation, this week’s horrific IoT example, some hopeful IoT legislation, the consequences of rooting early Amazon Echoes, the drip drip drip of Wikileaks Vault 7 drips again, Mozilla’s VERY interesting easy-to-use secure large file encrypted store and forward service, the need to know what your VPN service is really up to, a bit of errata, miscellany, and some closing-the-loop feedback from our always-attentive terrific listeners.

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Development of the Oriental Latrine Fly, Chrysomya megacephala (Diptera: Calliphoridae), at Five Constant Temperatures.

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Development of the Oriental Latrine Fly, Chrysomya megacephala (Diptera: Calliphoridae), at Five Constant Temperatures.

J Med Entomol. 2017 Mar 01;54(2):290-298

Authors: Gruner SV, Slone DH, Capinera JL, Turco MP

Abstract
Chrysomya megacephala (Fabricius) is a forensically important fly that is found throughout the tropics and subtropics. We calculated the accumulated development time and transition points for each life stage from eclosion to adult emergence at five constant temperatures: 15, 20, 25, 30, and 35 °C. For each transition, the 10th, 50th, and 90th percentiles were calculated with a logistic linear model. The mean transition times and % survivorship were determined directly from the raw laboratory data. Development times of C. megacephala were compared with that of two other closely related species, Chrysomya rufifacies (Macquart) and Phormia regina (Meigen). Ambient and larval mass temperatures were collected from field studies conducted from 2001-2004. Field study data indicated that adult fly activity was reduced at lower ambient temperatures, but once a larval mass was established, heat generation occurred. These development times and durations can be used for estimation of a postmortem interval (PMI).

PMID: 27816915 [PubMed – indexed for MEDLINE]

Development of the Forensically Important Beetle Creophilus maxillosus (Coleoptera: Staphylinidae) at Constant Temperatures.

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Development of the Forensically Important Beetle Creophilus maxillosus (Coleoptera: Staphylinidae) at Constant Temperatures.

J Med Entomol. 2017 Mar 01;54(2):281-289

Authors: Wang Y, Yang JB, Wang JF, Li LL, Wang M, Yang LJ, Tao LY, Chu J, Hou YD

Abstract
Creophilus maxillosus (L., 1758) is a common and widely distributed beetle species found on corpses, and its development duration is far longer than species belonging to the genus Calliphoridae and Sarcophagidae. Therefore, C. maxillosus can be used as a supplementary indicator to estimate minimum postmortem interval (PMImin), and could greatly extend the range of PMImin when the primary colonizers are no longer associated with the corpse or have emerged from pupae. Better descriptions of C. maxillosus development are needed to apply this species for forensic investigations. In this study, the development of C. maxillosus at seven constant temperatures ranging from 17.5-32.5 °C was studied. Through regression analyses, the simulation equations of larval body length variation with time after hatching were obtained. Isomegalen diagrams of the changes of larval body length over time at specific temperatures, and the isomorphen diagrams on the duration of different developmental milestones at specific temperatures were generated. In addition, thermal summation models of different developmental stages and the overall development process of C. maxillosus were generated through regression analysis, by estimating the development threshold temperatures (D0) and the thermal summation constants (K). These results provide important tools for forensic investigations to generate a long-range of PMImin estimation based on the development of C. maxillosus.

PMID: 28011726 [PubMed – indexed for MEDLINE]

Computed tomography evaluation of the iliac crest apophysis: age estimation in living individuals.

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Computed tomography evaluation of the iliac crest apophysis: age estimation in living individuals.

Int J Legal Med. 2016 Jul;130(4):1101-7

Authors: Ekizoglu O, Inci E, Erdil I, Hocaoglu E, Bilgili MG, Kazimoglu C, Reisoglu A, Can IO

Abstract
Determination of the ossification properties of the iliac apophysis is important not only in the clinical evaluation of patients undergoing orthopedic surgery but also in age estimation studies for forensic purposes. The literature includes both anthropological and radiological (conventional radiography, ultrasonography, and magnetic resonance imaging modalities) investigations of the different staging systems used for these purposes. In this study, we assessed the utility of computed tomography (CT) of the iliac crest apophysis in estimating forensic age. CT scans of the iliac crest apophysis of 380 patients (187 females, 193 males, and 10-29 years of age) were evaluated according to the four-stage system. Further subclassification did not give data properly due to the reference length measurement of the iliac wing with CT. Thus, in our series, stage 2 was first seen in 12 years of age and stage 3 in those 14 years of age in both sexes and on both sides of the pelvis. Stage 4 was first seen in 17 years of both sexes but only on the right side; on the left side, it appeared in females 18 years of age and in males 17 years of age. Present data was found consistent with previous pelvic radiographic findings. First seen ages for stage 2 and 3 are 12 and 14 years respectively which presented valuable information for legally important age thresholds. However, disadvantages of CT, including high-dose radiation exposure to gonads, the difficulty of evaluating the iliac crest, and the age boundary of 17 years, could make this method infeasible, as compared with hand wrist and pelvic radiographic methods. CT of the iliac crest has probably a greater utility where preexisting CT scans of the pelvic region are available, and it may be considered as a supportive method for age-estimation purposes.

PMID: 26914804 [PubMed – indexed for MEDLINE]

Third molar maturity index (I3M) for assessing age of majority in a black African population in Botswana.

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Third molar maturity index (I3M) for assessing age of majority in a black African population in Botswana.

Int J Legal Med. 2016 Jul;130(4):1109-20

Authors: Cavrić J, Galić I, Vodanović M, Brkić H, Gregov J, Viva S, Rey L, Cameriere R

Abstract
Assessment of legal age, also known as age of majority, is a controversial issue as there are few body biomarkers or evidence during late adolescence differentiating a subject from being a minor or adult. The third molar was recognized as a suitable site for age examination in late adolescence. We analyzed the development of the left mandibular third molar by the third molar maturity index (I3M) and a specific cut-off value of I3M = 0.08, established by Cameriere et al. in 2008 and used it for discriminating between minors and adult black Africans from Gaborone, Botswana. A final sample of panoramic radiographs (OPTs) of 1294 people (582 males and 712 females) aged between 13 and 23 years was evaluated. The real age decreased as I3M gradually increased. There was no statistically significant difference in the third molar development evaluated using I3M between males and females (p > 0.05) across different I3M classes. Results of 2 × 2 contingency tables for different cut-off values indicated that I3M = 0.08 was useful in discriminating between adults and minors. Precisely, for I3M = 0.08, the values of accuracy or overall fraction of correctly classified were 0.91 in males with a 95 % confidence interval (95 % CI) of 0.88 to 0.93 and 0.92 (95 % CI, 0.90 to 0.93) in females. Values of sensitivity of the test or the proportion of participants being 18 years and older were 0.88 (95 % CI, 0.87 to 0.90) in males and 0.88 (95 % CI, 0.90 to 0.93) in females, while values of specificity or proportion of individuals younger than 18 who have I3M <0.08 were 0.94 (95 % CI, 0.91 to 0.96) in males and 0.96 (95 % CI, 0.94 to 0.98) in females. Positive predictive values of the test, where the participants whose I3M <0.08 were adults, were 0.94 (95 % CI 0.91 to 0.96) in males and 0.97 (95 % CI, 0.94 to 0.98) in females, while negative predictive values of the test, where the participants whose I3M was ≥0.08 were minors, were 0.88 (95 % CI 0.85 to 0.90) in males and 0.97 (95 % CI, 0.94 to 0.98) in females. The likelihood ratios of the positive test (LR+) were 13.67 (95 % CI, 9.21 to 21.02) in males and 23.73 (95 % CI, 14.20 to 42.28) in females, while likelihood ratios of the negative test (LR-) were 0.12 (95 % CI 0.10 to 0.16) in males and 0.12 (95 % CI, 0.11 to 0.15) in females. Bayes post-test probabilities, p, were 0.94 (95 % CI 0.90 to 0.98) in males and 0.97 (95 %CI, 0.93 to 1.00) in females. These results indicate with high accuracy that I3M may be a useful alternative method in legal and forensic practice to discriminate individuals of black African origin who are around the legal adult age of 18 years in Botswana. Further studies should address the usefulness of this method and specific cut-off for different adolescent populations.

PMID: 26972694 [PubMed – indexed for MEDLINE]

Contribution of magnetic resonance imaging of the wrist and hand to forensic age assessment.

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Contribution of magnetic resonance imaging of the wrist and hand to forensic age assessment.

Int J Legal Med. 2016 Jul;130(4):1121-8

Authors: Serin J, Rérolle C, Pucheux J, Dedouit F, Telmon N, Savall F, Saint-Martin P

Abstract
Forensic age estimation of living individuals is a controversial subject because of the imprecision of the available methods which leads to errors. Moreover, young persons are exposed to radiation, without diagnostic or therapeutic advantage. Recently, non-invasive imaging techniques such as magnetic resonance imaging (MRI) have been studied in this context. The aim of this work was to study if the analysis of wrist/hand MRI enabled determination of whether a subject was 18 years old. Two observers retrospectively analyzed metaphyseal-epiphyseal fusion of the distal epiphysis of the radius and the ulna and the base of the first metacarpus in wrist/hand MRI of living people between 9 and 25 years of age. A three-stage scoring system was applied to all epiphyses. Intra- and inter-observer variability was excellent. Staging of the distal radial epiphysis allowed the subjects to be correctly evaluated with regard to the 18-year-old threshold in more than 85 % of cases. Analysis of the radius alone was as good as the analysis of the three epiphyses together. Evaluation of the metaphyseal-epiphyseal fusion of the distal radius in wrist MRI gave good results in forensic age estimation. Wrist MRI could meet ethical expectations with regard to the link between the benefit and risk of practicing radiologic examination on individuals in this context.

PMID: 27025715 [PubMed – indexed for MEDLINE]

Age estimation based on pelvic ossification using regression models from conventional radiography.

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Age estimation based on pelvic ossification using regression models from conventional radiography.

Int J Legal Med. 2016 Jul;130(4):1143-8

Authors: Zhang K, Dong XA, Fan F, Deng ZH

Abstract
To establish regression models for age estimation from the combination of the ossification of iliac crest and ischial tuberosity. One thousand three hundred and seventy-nine conventional pelvic radiographs at the West China Hospital of Sichuan University between January 2010 and June 2012 were evaluated retrospectively. The receiver operating characteristic analysis was performed to measure the value of estimation of 18 years of age with the classification scheme for the iliac crest and ischial tuberosity. Regression analysis was performed, and formulas for calculating approximate chronological age according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity were developed. The areas under the receiver operating characteristic (ROC) curves were above 0.9 (p < 0.001), indicating a good prediction of the grading systems, and the cubic regression model was found to have the highest R-square value (R (2) = 0.744 for female and R (2) = 0.753 for male). The present classification scheme for apophyseal iliac crest ossification and the ischial tuberosity may be used for age estimation. And the present established cubic regression model according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity can be used for age estimation.

PMID: 27169673 [PubMed – indexed for MEDLINE]

Age estimation based on pulp cavity/chamber volume of 13 types of tooth from cone beam computed tomography images.

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Age estimation based on pulp cavity/chamber volume of 13 types of tooth from cone beam computed tomography images.

Int J Legal Med. 2016 Jul;130(4):1159-67

Authors: Ge ZP, Yang P, Li G, Zhang JZ, Ma XC

Abstract
AIM: The aims of this study are to identify which type of tooth has the strong relationship between age and pulp cavity/chamber volume among 13 types of tooth from the same dentition and to determine whether the inclusion of multiple types of tooth may improve the accuracy of age estimation.
MATERIALS AND METHODS: Cone beam computed tomography (CBCT) images from 115 females and 125 males aged between 16 and 63 years were analyzed. The DICOM data of all the images were imported into ITK-SNAP 2.4 for the calculation of pulp cavity/chamber volumes. Logarithmic regression analysis and multiple linear regression analysis were applied to establish the relationship between age and pulp cavity/chamber volumes.
RESULTS: Among the 13 types of tooth, maxillary second molars have the largest R (2) (0.491, 0.642, and 0.498) and the smallest SEE (8.119, 6.754, and 8.022) in male, female, and pooled gender samples, respectively. The multiple linear regression analysis for the combination of multi-types of tooth indicated that a larger R (2) (0.627, 0.701, and 0.631) and smaller SEE (7.100, 6.258, and 6.970) than the counterpart calculated from the logarithmic regression analysis of a single type of tooth in male, female, and pooled gender samples, respectively.
CONCLUSION: The pulp chamber volume of the maxillary second molars has the largest correlation coefficient with age. Using multiple types of tooth may improve the accuracy of age estimation compared with only one type of tooth used.

PMID: 27221534 [PubMed – indexed for MEDLINE]

Index/Ring Finger Ratio, Hand and Foot Index: Gender Estimation Tools.

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Index/Ring Finger Ratio, Hand and Foot Index: Gender Estimation Tools.

J Clin Diagn Res. 2017 Jun;11(6):ZC73-ZC77

Authors: Gupta S, Gupta V, Tyagi N, Ettishree, Bhagat S, Dadu M, Anthwal N, Ashraf T

Abstract
INTRODUCTION: Gender estimation from dismembered human body parts and skeletal remains in cases of mass disasters, explosions, and assaults cases is an imperative element of any medico-legal investigations and has been a major challenge for forensic scientists.
AIM: The aim of the present study was to estimate the gender by using index and ring finger length ratio, hand and foot index along with the correlation of both the hand and foot index to determine the vital role of all the indices in establishing gender identity.
MATERIALS AND METHODS: A descriptive cross-sectional study was done on 300 subjects (150 males and 150 females). Various anthropometric measurements like hand length, hand breadth and hand index, Index Finger Length (IFL), Ring Finger Length (RFL) and IFL/RFL ratio as well as foot length, foot breadth and foot index were estimated in millimeters (mm) with the help of sliding-anthropometric caliper. The data was analysed using independent t-test and Pearson correlation coefficient test. A probability value (p) of ≤ 0.05 was considered statistically significant.
RESULTS: The index and ring finger ratio was found to be higher in females as compared to males. The hand and foot index was more in males than in females. The index and ring finger length ratio, hand and foot index between males and females was found to be statistically significant for both hands and feet. A statistically significant correlation was determined between hand indexes versus foot index.
CONCLUSION: This study can be useful to establish the gender of a dismembered hand or foot when subjected for medicolegal examination.

PMID: 28764298 [PubMed]