Development of Integrated Device of Trace Bloodstains Imaging and Age Analysis / 法医学杂志

Objective To develop a device of trace bloodstains imaging and age analysis, so as to provide a non-destructive, simple and objective method for age estimation of bloodstains at the crime scene. Methods Based on the principle of digital imaging and color pattern analysis, the mobile terminal of the device was used to collect images of bloodstains of different ages. The time-dependent pattern of 6 parameters （R, G, B, C, Y, M） reflecting the changes of color of images of different ages was obtained by computer image analysis. A multiparameter comprehensive inference equation of bloodstains age was established and embedded into the device software to realize the intelligent inference of the bloodstains age. Then the capability and reliability of the device was verified. Results This integrated device of bloodstains imaging and age analysis could quickly collect bloodstains at the crime scene and automatically analyze and infer the age of bloodstains combined with related intelligence software. In the blind test, the detection accuracy of this device was 95% in both natural light airtight group and dark airtight group, and 80% in the natural light ventilation group. Conclusion The integrated device of trace bloodstains imaging and age analysis can be used in a simple manner, which provides a new objective method for bloodstains age estimation.

Effect of Benzidine Test on DNA Analysis of Bloodstain / 法医学杂志

Objective To explore the effect of benzidine test and related reagents on DNA analysis of bloodstain. Methods A total of 970 bloodstain filter paper samples with 1μL venous blood were collected, and 10 of them acted as control samples. After benzidine test and related reagent processing, DNA of 960 samples was extracted by Chelex-100 and silica bead methods and then multiplex amplified by AmpF(e)STRTM IdentifilerTM Plus PCR kits. The results of STR typing were compared between different groups. Results DNA were extracted immediately after benzidine test. Totally STR loci (3.80±1.34) were detected by silica bead method, while no STR loci were obtained by Chelex-100 method. Thirteen sam-ples (21.7％) with whole STR typing results were obtained by drying after benzidine test, and the STR locus number (12.90±1.49) which obtained by silica bead method was much higher than by Chelex-100 method (4.70±1.96) (P<0.05). When DNA was extracted immediately after the addition of glacial acetic acid, the STR locus number was (9.40±2.09) by silica bead method, but no STR typing result was obtained by Chelex-100 method. All 15 STR loci could be obtained by only adding glacial acetic acid after drying and only adding tetramethylbenzidine alcoholization liquid or 3％ hydrogen peroxide liquid. Conclusion Benzidine test has significant influence on DNA analysis of bloodstain. The Chelex-100 method is not suitable for the DNA extraction of bloodstain after benzidine test. Drying after benzidine test and silica bead methods can effectively enhance the STR locus number of bloodstain.

Simulation and Observation of Vertical Cast-off Bloodstain Pattern / 法医学杂志

Objective To observe the characteristics of vertical cast-off bloodstain pattern by different hitting-tools. Methods The regular hitting tools, a kitchen knife, a dirk, a plane set-hammer and an iron pipe, were selected. At a distance of 30 cmaway fromthe wall, the hitting tool with 5 mL fresh chick-en blood made the cast-off bloodstain fromtop to bottom. Then the holistic distribution characteristics ( length , width and density ) of cast-off bloodstain and morphology characteristics ( length , width and contact angle) of first single cast-off bloodstain were analyzed. Results The distribution length of cast-off bloodstain formed by dirk was minimum( P<0 .05 ) . The distribution width of cast-off bloodstain formed by kitchen knife was minimum(P<0.05). Except the pair of kitchen knife and plane set-hammer, the distribution density between each two tools had statistical differences (P<0.05). The length of first single cast-off bloodstain formed by plane set-hammer was longest compared (P<0.05). The width of first single cast-off bloodstain had statistical differences between kitchen knife and plane set-hammer, and between dirk and plane set-hammer (P<0.05). Conclusion The type of hitting tool could be inferred by the specific characteristics of cast-off bloodstain pattern formed by every specific type of hitting tool in crime scene.

Talon noir: auxílio da dermatoscopia no diagnóstico diferencial de lesão pigmentada / Talon noir: dermoscopy assisted differential diagnosis of pigmented lesions

Talon noir foi descrita pela primeira vez em 1961 por Peachey, como erupção petequial traumática característica dos saltos dos jogadores de basquete e originalmente chamada de petéquias do calcâneo. É dermatose relacionada ao trauma, com lesões assintomáticas e marcada pela presença de sangue dentro do estrato córneo. Apresenta manifestações clínicas variadas e sua localização depende do fator provocativo envolvido. Os autores apresentam caso de talon noir em paciente com psoríase vulgar e demonstram a importância da correlação das características clínicas, dermatoscópicas e histopatológicas.

Talon noir was first described in 1961 by Peachey as atraumatic petechial eruption characteristic of basketball players' heels, and were originally called calcaneal petechiae. It is a dermatosis linked to trauma, with asymptomatic lesions, marked by the presence of blood within the stratum corneum. It presents varied clinical manifestations, with the location depending on the involved provocative fac-tor. The present study describes a case of talon noir in a patient with psoriasis vulgaris and demonstrates the importance of the correlation of clinical, dermoscopic, and histopathological characteristics.

PGM_1 SUBTYPING IN BLOODSTAINS AND A METHOD FOR PERMANENT STORAGE OF THE PGM1ZYMOGRAM / 中国法医学杂志

The effects of the temperature,materials and quantities of blood on results of PGM_1 phenotyping inbloodstains in a latin square were studied using polyacrylamide gel isoelectric focusing.The detectabletime of the bloodstains kept at 0℃,4℃,18℃ and 30℃ were 6 months,2 months,1 months and3 weeks respectively.The quantity of blood staining also had an effect on the detectable time of PGM_1subtyping in bloodstains.However,there was not any significant difference of detectable time of PGM_1subtyping in bloodstains on different materials was observed.In addition,a method for permanent storageof zymogram was developed using polyester sheet.

SPECIES IDENTIFICATION OF BLOOD STAINS USING ISOELECTRIC FOCUSING WITH AMPHOLINE MADE IN CHINA / 中国法医学杂志

The spceics identification by the hemoglobin band patterns in blood stains using isoelectric focusing with amphotine made in China is reported. Forty different sorts of bloodstain from human and animals were studied. Although the ability of species identification of hemogolbin band patterns in blood stains is lower than those in hemolysates, but the indentification of humen blood stain and the blood stains from most different spcies of animads were achieved. With the exception blood stain indintification between human adult foetus and monkey as well as between five groups in classes of bird and fish Human adult blood stain could be distinguished much easily from animal's blood stains but not from human foetus ,if the blood stairis were pretreated with PCMB. It is concluded that the species indentification of blood staine using isoelectice focusing with ampholinemade in china is possible.