Could routine forensic STR genotyping data leak personal phenotypic information?

The application of forensic genetic markers must comply with privacy rights and legal policies on a premise that the markers do not expose phenotypic information. The most widely-used short tandem repeats (STRs) are generally viewed as 'junk' DNA because most STRs are located in non-coding regions and therefore refrain from leaking phenotypic traits. But with a deepening understanding of phenotypes and underlying genetic structure, whether STRs could potentially reflect any phenotypic information may need re-examining. Therefore, we performed the following analyses. First, we analyzed the association between 15 STRs and three facial characteristics (single or double eyelid, with or without epicanthus, unattached or attached earlobe) on 721 unrelated Han Chinese individuals. Then, we collected 27199 individuals' STRs and geographic data from the literature to investigate the association between STRs and bio-geographic information, and predict geographic information by STRs on additional 1993 unrelated individuals. We found that there was scarcely any association between STRs with studied facial characteristics. Although allele19 in D2S1338 and allele 18 in FGA (P = 0.0032, P = 0.0030, respectively after Bonferroni correction) showed statistical significance, the prediction effectiveness was very low. For the STRs and bio-geographic information, the principal component analysis showed the first three components could explain 87.7% of the variance, but the prediction accuracy only reached 25.2%. We demonstrated that the forensic phenotypes are usually complex traits, it is hardly possible to uncover phenotypic information by testing only dozens of STR loci.

Sudden unexpected death due to spontaneous pneumothorax caused by ruptured bilateral pulmonary bullae.

Sudden unexpected death due to pneumothoraces caused by spontaneous rupture of bilateral pulmonary bullae is rare. This article reports the case of a 16-year-old girl who experienced this rare phenomenon without any precipitating factors. The patient did not have a history of chest pains or smoking but experienced chest tightness in the early morning and collapsed and died 4 h later. Autopsy identified the cause of death to be bilateral pneumothoraces and massive bilateral pulmonary collapse (atelectasis) due to ruptured apical bullae of the bilateral lungs. No injuries or other significant pathological findings were identified. A low body mass index (16.5) may have been a risk factor for the spontaneous tension pneumothoraces. In some situations, genetic counseling and testing may be helpful in identifying a heritable process associated with spontaneous pneumothoraces.

Development of Megaselia spiracularis (Diptera: Phoridae) at different constant temperatures.

Megaselia spiracularis Schmitz, 1938 (Diptera: Phoridae) is a pest that often appears in human living areas where it can spread pathogens. Besides, the species is of forensic value. Currently, studies focusing on the development of this species are limited. Understanding the developmental patterns of M. spiracularis, therefore, is important for controlling populations of this pest and for estimating the minimum postmortem interval (PMImin). Here, we studied the development of M. spiracularis exposed to seven constant temperatures ranging from 16 to 34 °C. The developmental durations, accumulated degree hours and larval body length changes were measured. Three kinds of development models that can be used to estimate the PMImin were established, including isomorphen diagram, isomegalen diagram and thermal summation model. The duration of M. spiracularis development at 16, 19, 22, 25, 28, 31 and 34 °C from egg to adult stage were 1131.1 ± 34.5, 807.3 ± 9.3, 529.6 ± 1.8, 367.0 ± 8.8, 302.4 ± 7.0, 250.0 ± 2.1 and 232.6 ± 1.9 h, respectively. The developmental threshold temperature and the thermal summation constant were estimated as 12.0 ± 0.5 °C and 4989.7 ± 308.9° hours, respectively. A general model represented by a logistic equation describing how larval body length will change with the time after hatching was fit to data. The present study provides basic developmental data of M. spiracularis, which can be used for achieving better control of this noxious insect as well as for estimation of its PMImin at different temperatures.

Development of Necrobia rufipes (De Geer, 1775) (Coleoptera: Cleridae) under constant temperatures and its implication in forensic entomology.

After the death of humans or animals, the odors released at different stages of decay attract various insects, and other arthropods, to the corpses. Therefore, the development of insects, and other arthropods present on corpses, can be assessed to estimate the minimum postmortem interval since death. In general, necrophagous blow flies are the insects that first colonize corpses. With progressing decay, other necrophagous and predatory insects arrive at the corpses, which will develop on or around these either by feeding directly on the corpses or by prey on other immature insects. Beetles (Coleoptera) mainly arrive at the corpses during the later stages of decay, and play important roles in cases with longer postmortem intervals. Necrobia rufipes (De Geer, 1755) (Coleoptera: Cleridae) is an important stored-product species with world-wide distribution. Moreover, it is also a forensically important insect species. At temperatures of 22, 25, 28, 31, 34, and 36°C (±0.5°C), the developmental periods from egg to adult were 113.20±2.96, 66.16±3.22, 50.61±1.95, 38.26±2.48, 37.97±2.40, and 31.20±2.11 days, respectively. In vivo measurements obtained the morphological indexes of larvae. The growth curve and the equation of the relationship between development time, body lengths, and mesonotum widths were simulated. The isomorphen diagram model, the isomegalen diagram model, and the thermal summation model were established. In addition, the widths of head capsules and pronota of larvae at different instars were determined by cluster analysis. Classifiers were created and validated by linear discriminant analysis.

Development of Lucilia sericata (Diptera: Calliphoridae) Under Constant Temperatures and its Significance for the Estimation of Time of Death.

Forensic entomologists usually estimate the minimum postmortem interval (PMImin) using the time required for the oldest immature insects found on the corpse to grow to its development stage and age at the time of discovery. The sheep blow fly Lucilia sericata (Meigen, 1826) is a carrion fly found nearly worldwide, and important in forensics. We studied the development time of L. sericata from egg to adult at constant temperatures of 16, 19, 22, 25, 28, 31, and 34°C, and found that the times required are 913.2 ± 19.4, 588.8 ± 35.8, 459.8 ± 15.2, 373.2 ± 15.3, 308.0 ± 9.7, 272.5 ± 9.2, and 267.5 ± 10.5 h, respectively. We established three development models to infer the age of the immature insect: isomegalen diagram, isomorphen diagram, and thermal summation model. In addition, a regression analysis was performed on the relationship between body length and total development time from hatching to dispersing. The thermal summation constant during the development of L. sericata is 6023.2 degree hours and development threshold temperature is 9.19°C. The results of this experiment provide a basis for the use of L. sericata in the estimation of PMImin.

[Expression of Fas protein in myocardiac tissue of viral myocarditis and dilated cardiomyopathy].

OBJECTIVE: To study the pathogenesis of viral myocarditis (VMC) and dilated cardiomyopathy (DCM) and their relationship. METHODS: Sixty samples including 20 VMC, 20 DCM and 20 controls were collected. The expression of Fas protein in myocardium of each group was detected by modified immunohistochemistry with unequivocal brown staining in the myocardial membrane scored as positive, and the results of positive reaction were analyzed by Ridit test. RESULTS: Fas protein expression increased obviously in VMC and DCM groups as compared with that of the control group. The difference of positive results between each group analyzed by Ridit test was statistically significant (P<0.005). Statistically significant differences were found between VMC and control groups as well as between DCM and control groups (P<0.05), but not between VMC and DCM groups (P>0.05) by multiple comparison Ridit test. CONCLUSION: The expression of Fas protein is significantly higher in the VMC and DCM groups than in that of the control group. These results suggest that both the VMC and DCM may share a similar pathogenesis, which most likely involves cell apoptosis.

[Bcl-2 expression following the brain concussion in rats].

OBJECTIVE: To evaluate the expression of Bcl-2 protein after brain concussion. METHODS: Expression levels of Bel-2 protein in cortex, pontine and cerebellum of rats were investigated using immunohistochemistry. RESULTS: There was no expression of Bcl-2 protein in control group seen. The expression of Bcl-2 protein in brain concussion groups was detected at l hour, and the expression level reached its peak 4 days after the concussion and then declined gradually. CONCLUSION: Our findings suggest that the detection of Bel-2 protein could be an indicator for diagnosis of brain concussion and for estimation of the post injury time interval.

[Apoptosis in myocardial cells after macleaya cordata total alkaloids poisoning in rats].

OBJECTIVE: To observe pathological changes and apoptosis in rats myocardial cells after Macleaya cordata total alkaloids poisoning, and to provide some references for Macleaya cordata total alkaloids poisoning detection. METHODS: An experimental model of Macleaya cordata total alkaloids poisoning was established, and the technology of TUNEL staining was used.The results were analyzed by computer image analysis competitive system. RESULTS: Quantities of apoptosis in myocardial cells in poisoning groups were much more than those in the control groups at different tages (P<0.01). In addition the quantities of apoptosis were different after different poisoning duration. CONCLUSION: Although clinical symptoms was not obvious and could not be detected by poison analysis. Pathological changes induced by Macleaya cordata total alkaloids could be found through the apoptosis detection.