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1.
Zhongguo Zhong Yao Za Zhi ; 49(5): 1397-1405, 2024 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-38621988

RESUMO

This study employed evidence mapping to systematically sort out the clinical studies about the treatment of premature ventricular contractions with Chinese patent medicines and to reveal the distribution of evidence in this field. The articles about the treatment of premature ventricular contractions with Chinese patent medicines were searched against PubMed, Cochrane Library, Web of Science, CNKI, Wanfang, and VIP with the time interval from January 2016 to December 2022. Evidence was analyzed and presented by charts and graphs combined with text. According to the inclusion and exclusion criteria, 164 papers were included, including 147 interventional studies, 4 observational studies, and 13 systematic reviews. A total of 27 Chinese patent medicines were involved, in which Shensong Yangxin Capsules and Wenxin Granules had high frequency. There were off-label uses in clinical practice. In recent years, the number of articles published in this field showed a decreasing trend. Eight types of outcome indicators were used in interventional studies. Ambulatory electrocardiography, clinical response rate, safety, and echocardiography had high frequency, while the rate of ß-blocker decompensation, major cardiovascular events, and pharmaceutical economic indicators were rarely reported. The evaluation was one-sided. The low quality of the included articles reduced the reliability of the findings. In the future, the clinical use of medicines should be standardized, and the quality of clinical studies should be improved. Comprehensive clinical evaluation should be carried out to provide a sound scientific basis for the treatment of premature ventricular contractions with Chinese patent medicines.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional do Leste Asiático , Complexos Ventriculares Prematuros , Humanos , Complexos Ventriculares Prematuros/tratamento farmacológico , Medicamentos sem Prescrição/uso terapêutico , Reprodutibilidade dos Testes , Medicamentos de Ervas Chinesas/uso terapêutico , Cápsulas
2.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(1): 42-46, 2024 Jan 10.
Artigo em Chinês | MEDLINE | ID: mdl-38171558

RESUMO

OBJECTIVE: To study the genetic polymorphisms of short-tandem repeats (STR) for the D13S317 locus among an ethnic Han Chinese population and verify a novel tri-allelic pattern identified for the locus. METHODS: A total of 378 paternity test cases from Guangdong Forensic Authentication Institute from October 17, 2017 to December 28, 2017 were selected as the study subjects. A GlobalFilerTM Express kit was used for the STR genotyping. Samples suspected for having a novel tri-allelic pattern were verified with a PowerPlex 21 kit. Potential variant of the primer-binding region and flanking sequences underlying the tri-allelic pattern was excluded by molecular cloning and sequencing. RESULTS: Six alleles were detected for the D13S317 locus, with the characteristic distribution frequencies being 8 (29.1%), 9 (13.1%), 10 (15.21%), 11 (24.21%), 12 (13.89%) and 13 (3.44%), respectively. In one of the families, the D13S317 locus of the proband was suspected to harbor a triband allele (8, 9, 10). A re-test has confirmed the result of initial test. Molecular cloning and sequencing analysis of the D13S317 locus in the proband and his daughter has failed to find allelic variants in the primer-binding region and flanking sequence, which has confirmed the novel tri-allelic pattern for the locus. CONCLUSION: A novel type 2 tri-allelic pattern (8, 9, 10) at the D13S317 locus has been identified among the ethnic Han Chinese population. The pattern has not been transmitted to the female offspring, and has been included in the international STRBase database for the first time.


Assuntos
População do Leste Asiático , Polimorfismo Genético , Humanos , Alelos , China , Clonagem Molecular , Frequência do Gene , Genética Populacional , Repetições de Microssatélites , População do Leste Asiático/genética
3.
HLA ; 101(2): 184-185, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36269608

RESUMO

HLA-C*08:236N differs from C*08:01:01 by a single nucleotide exchange in exon 5 at position 1991.


Assuntos
População do Leste Asiático , Antígenos HLA-C , Humanos , Antígenos HLA-C/genética , Alelos , Povo Asiático/genética , Sequenciamento de Nucleotídeos em Larga Escala
4.
Electrophoresis ; 42(6): 766-773, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33415769

RESUMO

With a unique inheritance pattern compared to autosomal short tandem repeats (A-STRs), X chromosomal STRs (X-STRs) have special usage in forensic relationship testing. In this study, we designed a multiplex amplification system (named TYPER-X19 multiplex assay) consisting of 18 STR loci spreading from 7.837 to 149.460 Mb on the X chromosomes (DXS9895, DXS8378, DXS9902, DXS6810, DXS7132, DXS10079, DXS6789, DXS7424, DXS101, DXS6797, DXS7133, DXS6804, GATA165B12, DXS10103, HPRTB, GATA31E08, DXS8377, and DXS7423), and the amelogenin. PCR primers were marked with four kinds of fluorophores including FAM, HEX, TAMRA, and ROX. The multiplex system was optimized and tested for precision, concordance, reproducibility, sensitivity, stability, DNA mixture, and species specificity according to the conventional validation guidelines. The results indicated that the system was accurate, reliable, and sensitive enough, and was suitable for common forensic case-type samples. In the population genetic study, a total of 148 alleles were detected at the 18 X-STR loci in 398 Southern Han Chinese. Relatively high combined power of discrimination in male (PDm ), power of discrimination in female (PDf ), mean paternity exclusion chance in trios (MECtrio ), and mean paternity exclusion chance in duos (MECDuo ) by Desmarais were detected, and HPRTB-DXS10103 was in linkage disequilibrium. The results suggested that the TYPER-X19 multiplex assay was suitable for forensic applications.


Assuntos
Cromossomos Humanos X , Genética Forense , Genética Populacional , Cromossomos Humanos X/genética , Impressões Digitais de DNA , Feminino , Frequência do Gene , Humanos , Masculino , Repetições de Microssatélites/genética , Reprodutibilidade dos Testes
5.
Ann Hum Biol ; 48(1): 66-69, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33256486

RESUMO

Nowadays, kinship testing is very common in forensic caseworks, but the power of autosomal short tandem repeats (A-STRs) may be limited in complex cases. X-Chromosome short tandem repeats (X-STRs), having a unique heritage mode, should be of special use in some deficient cases. To evaluate and compare the potential of A-STR and X-STR as supplement genetic markers in deficient kinship testing, we simulated 10,000 duos for each of 18 kinds of relationships involving full sibling, half-sibling, grandparent-grandchild, and uncle/aunt-nephew/niece. Loci from STRTyper10, PowerPlex 16, and Investigator Argus X-12 were studied in Southern Han Chinese and the distribution of likelihood ratio (LR) values was analysed. With the addition of the X-12 system, the distribution of LR values for the full sisters, paternal half-sisters, paternal grandmother-granddaughters, maternal aunt-nieces, and maternal aunt-nephews separated much more obviously from those of unrelated duos, and the effectiveness was 1.0000, 0.99865, 0.9991, 0.8996 and 0.9634, respectively, which was more efficient than A-STRs. For the individual duos with other relationships, the effects of adding X-STRs and A-STRs were similar. Therefore, for the Southern Han Chinese, X-STRs can be very useful in kinship testing involving full sisters, paternal half-sisters, paternal grandmother-granddaughters, and maternal aunt-nieces/nephews.


Assuntos
Cromossomos/genética , Testes Genéticos/instrumentação , Repetições de Microssatélites/genética , Cromossomos Humanos X/genética , Humanos
6.
Sci Rep ; 10(1): 12225, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32699278

RESUMO

Massively parallel sequencing (MPS) has rapidly become a promising method for forensic DNA typing, due to its ability to detect a large number of markers and samples simultaneously in a single reaction, and sequence information can be obtained directly. In the present study, two kinds of forensic genetic markers, short tandem repeat (STR) and identity-informative single nucleotide polymorphism (iiSNP) were analyzed simultaneously using ForenSeq DNA Signature Prep Kit, a commercially available kit on MPS platform. A total of 152 DNA markers, including 27 autosomal STR (A-STR) loci, 24 Y chromosomal STR (Y-STR) loci, 7 X chromosomal STR (X-STR) loci and 94 iiSNP loci were genotyped for 107 Tibetan individuals (53 males and 54 females). Compared with length-based STR typing methods, 112 more A-STR alleles, 41 more Y-STR alleles, and 24 more X-STR alleles were observed at 17 A-STRs, 9 Y-STRs, and 5 X-STRs using sequence-based approaches. Thirty-nine novel sequence variations were observed at 20 STR loci. When the flanking regions were also analyzed in addition to target SNPs at the 94 iiSNPs, 38 more alleles were identified. Our study provided an adequate genotype and frequencies data of the two types of genetic markers for forensic practice. Moreover, we also proved that this panel is highly polymorphic and informative in Tibetan population, and should be efficient in forensic kinship testing and personal identification cases.


Assuntos
Repetições de Microssatélites/genética , Polimorfismo de Nucleotídeo Único/genética , Alelos , Impressões Digitais de DNA/métodos , Feminino , Frequência do Gene/genética , Marcadores Genéticos/genética , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Análise de Sequência de DNA/métodos , Tibet
7.
Forensic Sci Int Genet ; 48: 102323, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32574994

RESUMO

African populations exhibit extensive linguistic and cultural diversity but are less studied from a population genetic standpoint. Although much genetic data on admixed African individuals, such as African Americans, have been published, genetic polymorphism data, especially that based on sequence-based typing, are still insufficient in indigenous Africans. In this study, we examined the genetic diversity of 85 Nigerians residing in Guangzhou, China. Forensically relevant genetic markers, including autosomal short tandem repeats (A-STRs), X-chromosomal STRs (X-STRs), Y-chromosomal STRs (Y-STRs), and identity-informative single nucleotide polymorphisms (iiSNPs) were genotyped to uncover the genetic polymorphisms of this population. Sequence-based allelic variations were observed in 22 A-STRs, ten Y-STRs, and four X-STRs. Using massively parallel sequencing (MPS), the allele number increased from 475 length-based alleles to 683 sequence-based alleles. Compared to other populations, the overall observed heterozygosity of the 27 A-STRs was the highest in Nigerians, which reflected the higher genetic diversity of this population. The combined match probability of the 27 A-STRs was low at 9.06 × 10-38. When both A-STRs and iiSNPs were considered, the cumulative discrimination power, and combined power of exclusion for duo and trio paternity testing was 1-2.97 × 10-57, 1-2.20 × 10-10 and 1-4.61 × 10-17, respectively, which demonstrated that the STRs and SNPs analyzed here can be applied to forensic investigations. In summary, this study uncovers the genetic features of the Nigerian population and provides valuable frequency data for forensic applications.


Assuntos
População Negra/genética , Genética Populacional , Sequenciamento de Nucleotídeos em Larga Escala , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , China , Cromossomos Humanos X , Cromossomos Humanos Y , Impressões Digitais de DNA , Feminino , Frequência do Gene , Genótipo , Heterozigoto , Humanos , Masculino , Nigéria/etnologia , Análise de Sequência de DNA
8.
Forensic Sci Int Genet ; 45: 102225, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31865225

RESUMO

Despite improvements in characterizing stutters of short tandem repeats (STRs), the relationships among the amounts of stutter variants and the relationships among motifs are not well understood yet. In the present study, 750 peripheral blood samples from human subjects were included to characterize the stutters of 58 STRs via the ForenSeq DNA Signature Prep Kit on a MiSeq FGx instrument. Alleles and corresponding stutter products were identified with a sequence simplification procedure. After screening, 26,921 alleles were included, that resulted in over 50 million reads, among which 8.69% were stutter products. Among these stutter products, 83.44% were N-1 stutters. Additionally, N-4, N-3, N-2, N0, N + 1, and N + 2 variants accounted for 0.11%, 0.77%, 6.45%, 3.01%, 5.95%, and 0.25% of the stutter products, respectively. For backward stutters, stutter products correlated best with the corresponding one-unit-longer stutter (or parental allele), which may represent a good predictor for backward stutters. For forward stutters, the N + 2 stutter correlated best with the N + 1 stutter, whereas the N + 1 stutter correlated best with the N-1 stutter rather than the expected parental allele, which indicated that the patterns were more complex for forward stutters. Additionally, some interesting findings were obtained for D21S11. For two adjacent contiguous motifs, co-stuttering patterns were observed where one motif tended to increase one repeat unit while the other motif decreased one repeat unit, whereas the inter-motif dependency was not significant for interrupted motifs. In conclusion, with massively parallel sequencing technology and our sequence simplification strategy, sequence variations within alleles and stutter products were identified, which was useful to determine the origin of stutters, identify more stutter variants, and explore the relationships among motifs. These findings may be helpful for allele designation, a deeper understanding of the mechanism of stutter, and improving resolution in forensic mixture analyses.


Assuntos
Alelos , Impressões Digitais de DNA , Sequenciamento de Nucleotídeos em Larga Escala , Repetições de Microssatélites , Humanos
9.
Forensic Sci Int Genet ; 42: 235-243, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31382158

RESUMO

Mongolians played a pivotal role in shaping the culture and genetic architecture of modern Eurasia through the rapid expansion of the Mongol Empire in the 13th century. While the historical aspects of the Mongolian Empire are well documented, research on the genetic variations among Mongolian populations is still insufficient. In this study, we examined the genetic diversity of 70 Torghut Mongols residing in the Ili region of China compared with 88 Jalaid Mongols residing 3000 km away. Over 200 forensically relevant genetic markers, including autosomal short tandem repeats (A-STRs), X chromosomal STRs (X-STRs), Y chromosomal STRs (Y-STRs), identity-informative single nucleotide polymorphisms (iiSNPs), ancestry-informative SNPs (aiSNPs), and phenotype-informative SNPs (piSNPs), were genotyped to uncover the genetic polymorphism of the Torghut Mongols. The STR genotyping results showed that 80 alleles (39 A-STRs, 25 Y-STRs, and 16 X-STRs; 14.4% of 554 alleles) identified in Torghut Mongols were not identified in Jalaid Mongols, while 155 alleles (84 A-STRs, 59 Y-STRs and 12 X-STRs; 24.6% of 630 alleles) identified in Jalaid Mongols were not observed in Torghut Mongols. Calculation of the forensic parameters demonstrated that the STRs and SNPs analyzed here could be employed in forensic applications. Interpopulation comparisons via principal component analysis (PCA), phylogenetic tree, and STRUCTURE analysis showed that the two Mongolian populations were closely related by their genetic background, although genetic differences were also discovered. When both the sequence-based A-STRs and iiSNPs were included in the STRUCTURE analysis, the Torghut population was more similar to the Uyghur population than to Jalaid Mongols, indicating certain population structure differences between the two Mongolian populations. The Y-DNA haplogroup prediction showed that although haplogroup C (C2-M217) was dominant in both Mongolian populations, haplogroup O2-M122 was rarely presented in Torghut Mongols, which differentiated the Torghut Mongols from the other Mongolian populations. This study not only uncovered the genetic features of the two Mongolian tribes, providing valuable frequency data for forensic applications, but the genetic patterns of the two Mongolian populations also provide a genetic evidence that the Torghut Mongols may have developed via the gradual intermixing of nomadic groups of Mongol and Turkic origin, as recorded in historical records. This study also highlighted the importance of building regional reference databases that consider both ethnic and geographic location information, instead of a more universal reference database, for forensic applications.


Assuntos
Etnicidade/genética , Genética Populacional , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , Povo Asiático/genética , China , Cromossomos Humanos X , Cromossomos Humanos Y , Impressões Digitais de DNA , Feminino , Genótipo , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mongólia/etnologia , Análise de Componente Principal , Análise de Sequência de DNA
10.
J Hum Genet ; 64(1): 29-38, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30348993

RESUMO

The human leukocyte antigen (HLA) genes are the most polymorphic genes in the human genome and have great power in forensic applications, especially in relationship testing and personal identification. However, the extreme polymorphism of HLA has made unambiguous genotyping of these genes very challenging and resulted in the limited application in relationship testing. Fortunately, massively parallel sequencing (MPS) technology offers the promise of unambiguous and high-throughput HLA typing. In this study, 11 HLA genes were typed in one extended family residing in North China and encompassing six generations. Phase-resolved genotypes for HLA genes were generated and HLA haplotype structure was defined. The paternity/kinship index, or in other words, likelihood ratio (LR) was calculated. A total of 88 alleles were identified, of which eight alleles were newly discovered. The inheritance of HLA alleles followed Mendelian law. With the discovery of new HLA alleles and three recombination events, a total of eleven new HLA haplotypes were identified in this population. LR distribution showed that, when HLA alleles were applied, the Log10LR for a single locus could reach very high and the median average Log10LRs of HLA genes were much higher than that of short tandem repeat loci. The result showed that high-throughput HLA genotyping could be achieved rapidly by MPS, and the contribution of HLA genes on system performance could be high, which may be applied as a supplement in forensic genetics studies. This study was also valuable in demonstrating the genetic mechanisms governing the generation of polymorphisms of the HLA genes.


Assuntos
Testes Genéticos/métodos , Antígenos HLA/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Teste de Histocompatibilidade/métodos , Polimorfismo Genético , Análise de Sequência de DNA/métodos , Família , Feminino , Genoma Humano , Genótipo , Haplótipos , Humanos , Masculino
11.
Ann Hum Biol ; 45(4): 359-364, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30200780

RESUMO

AIM: To evaluate the 23 autosomal short tandem repeat (STR) loci included in GoldenEye™ 25 A kit using forensic human identification and paternity testing. SUBJECTS AND METHODS: In total, 3751 unrelated individuals from the Southern Chinese Han population were genotyped with the 5-dye GoldenEye™ 25 A multiplex amplification system. PCR products were separated using arrayed capillary electrophoresis. Allele frequencies and forensic parameters for the 23 autosomal STR loci were statistically analysed. RESULTS: A total of 344 alleles were observed, with corresponding allelic frequencies ranging from 0.0001-0.5519 for the 23 STR loci. No significant deviation from the Hardy-Weinberg equilibrium and linkage disequilibrium was observed. The combined power of discrimination (CPD) was 1-1.6290 × 10-28 and the combined power of exclusion (CPE) was 0.999 999 999 89 and 0.999 999 286 93 for trio and duo cases, respectively. From 3865 meioses, 87 mutation events were discovered. The mutation rate varied from 0-0.00285 for each locus. One-step mutation accounted for 94.25% of total mutations. The ratio of paternal vs maternal mutation was 3.76:1.13 kinds of n/(n + 1) heterozygote genotypes were observed. CONCLUSIONS: The results show that 23 STR loci of GoldenEye™ 25 A kit are highly polymorphic in the Southern Chinese Han population, indicating the kit is suitable for forensic application.


Assuntos
Frequência do Gene , Repetições de Microssatélites/genética , Mutação , Polimorfismo Genético , China , Humanos
12.
Int J Legal Med ; 132(3): 667-674, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28821964

RESUMO

In this study, we investigated the potential of attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy combined with advanced chemometrics for species identification of bloodstains similar to evidence obtained from real crime scenes. Two partial least squares-discriminant analysis classification models (a human-mammal-domestic fowl trilateral model and a species-specific model) were established. The models demonstrated complete separation among the three classes (human, mammal, and domestic fowl) and distinguished six species (human, rat, rabbit, dog, chicken, and duck). Validation was subsequently conducted to evaluate the robustness of these two models, which resulted in 100 and 94.2% accuracy; even human bloodstains placed in an outdoor environment for up to 107 days were successfully identified. Additionally, all bloodstains were positively identified as blood using the squared Euclidean cosine method by comparing the spectra with those of non-blood substances that had a similar appearance or easily produced false positives. These results demonstrate that ATR-FTIR spectroscopy combined with chemometrics can be a powerful tool for species identification of bloodstains.


Assuntos
Manchas de Sangue , Especificidade da Espécie , Espectroscopia de Infravermelho com Transformada de Fourier , Animais , Galinhas , Análise Discriminante , Cães , Patos , Meio Ambiente , Medicina Legal , Humanos , Análise dos Mínimos Quadrados , Análise de Componente Principal , Coelhos , Ratos , Fatores de Tempo
13.
Forensic Sci Int ; 281: 113-120, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29127892

RESUMO

Due to a lack of reliable and accurate methods, determining the postmortem interval (PMI) of human skeletal remains is one of the most important and challenging tasks in forensic medicine. In this paper, we studied the changes to bone chemistry with increasing PMI in two different experimental conditions using Fourier transform infrared (FTIR) spectroscopy in conjunction with chemometrics methods Paired bone samples collected from 56 human corpses were buried (placed in soil) and unburied (exposed to the air) for intervals between 76 and 552 days. The results of principle component analysis (PCA) showed the chemical differences of these two cases had a significant influence on the rate of decomposition of the remains. Meanwhile, satisfactory predictions were performed by the genetic algorithm combined with partial least-squares (GA-PLS) with the root mean square errors of prediction (RMSEP) of 50.93days for buried bones and 71.03days for unburied bones. Moreover, the amide I region of proteins and the area around 1390cm-1, which is associated with fatty acids, were identified with regular changes by GA-PLS and played an important role in estimating PMI. This study illustrates the feasibility of utilizing FTIR spectroscopy and chemometrics as an attractive alternative for estimating PMI of human remains and the great potential of these techniques in real forensic cases with natural conditions.


Assuntos
Mudanças Depois da Morte , Crânio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Adolescente , Adulto , Idoso , Algoritmos , Restos Mortais , Sepultamento , Criança , Pré-Escolar , Ácidos Graxos , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Proteínas , Adulto Jovem
14.
Sci Rep ; 7(1): 13254, 2017 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-29038589

RESUMO

Estimation of the age of human bloodstains is of great importance in forensic practices, but it is a challenging task because of the lack of a well-accepted, reliable, and established method. Here, the attenuated total reflection (ATR)-Fourier transform infrared (FTIR) technique combined with advanced chemometric methods was utilized to determine the age of indoor and outdoor bloodstains up to 107 days. The bloodstain storage conditions mimicked crime scene scenarios as closely as possible. Two partial least squares regression models-indoor and outdoor models with 7-85 days-exhibited good performance for external validation, with low values of predictive root mean squared error (5.83 and 4.77) and high R2 values (0.94 and 0.96) and residual predictive deviation (4.08 and 5.14), respectively. Two partial least squares-discriminant analysis classification models were built and demonstrated excellent distinction between fresh (age ≤1 d) and older (age >1 d) bloodstains, which is highly valuable for forensic investigations. These findings demonstrate that ATR-FTIR spectroscopy coupled with advanced chemometric methods can be employed as a rapid and non-destructive tool for age estimation of bloodstains in real-world forensic investigation.


Assuntos
Manchas de Sangue , Crime , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Discriminante , Medicina Legal/métodos , Humanos , Análise Multivariada , Curva ROC , Análise de Regressão , Fatores de Tempo
15.
PLoS One ; 12(7): e0182161, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28753641

RESUMO

Estimating PMI is of great importance in forensic investigations. Although many methods are used to estimate the PMI, a few investigations focus on the postmortem redistribution. In this study, ultraviolet-visible (UV-Vis) measurement combined with visual inspection indicated a regular diffusion of hemoglobin into plasma after death showing the redistribution of postmortem components in blood. Thereafter, attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy was used to confirm the variations caused by this phenomenon. First, full-spectrum partial least-squares (PLS) and genetic algorithm combined with PLS (GA-PLS) models were constructed to predict the PMI. The performance of GA-PLS model was better than that of full-spectrum PLS model based on its root mean square error (RMSE) of cross-validation of 3.46 h (R2 = 0.95) and the RMSE of prediction of 3.46 h (R2 = 0.94). The investigation on the similarity of spectra between blood plasma and formed elements also supported the role of redistribution of components in spectral changes in postmortem plasma. These results demonstrated that ATR-FTIR spectroscopy coupled with the advanced mathematical methods could serve as a convenient and reliable tool to study the redistribution of postmortem components and estimate the PMI.


Assuntos
Plasma/química , Mudanças Depois da Morte , Espectroscopia de Infravermelho com Transformada de Fourier , Algoritmos , Animais , Coelhos , Espectrofotometria Ultravioleta
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 173: 733-739, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-27788472

RESUMO

Postmortem interval (PMI) determination is one of the most challenging tasks in forensic medicine due to a lack of accurate and reliable methods. It is especially difficult for late PMI determination. Although many attempts with various types of body fluids based on chemical methods have been made to solve this problem, few investigations are focused on blood samples. In this study, we employed an attenuated total reflection (ATR)-Fourier transform infrared (FTIR) technique coupled with principle component analysis (PCA) to monitor biochemical changes in rabbit plasma with increasing PMI. Partial least square (PLS) model was used based on the spectral data for PMI prediction in an independent sample set. Our results revealed that postmortem chemical changes in compositions of the plasma were time-dependent, and various components including proteins, lipids and nucleic acids contributed to the discrimination of the samples at different time points. A satisfactory prediction within 48h postmortem was performed by the combined PLS model with a good fitting between actual and predicted PMI of 0.984 and with an error of ±1.92h. In consideration of the simplicity and portability of ATR-FTIR, our preliminary study provides an experimental and theoretical basis for application of this technique in forensic practice.


Assuntos
Proteínas Sanguíneas/metabolismo , Lipídeos/sangue , Ácidos Nucleicos/sangue , Mudanças Depois da Morte , Animais , Coelhos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Fatores de Tempo
17.
J Forensic Sci ; 62(3): 761-767, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27982433

RESUMO

The time since deposition (TSD) of a bloodstain is a valuable piece of evidence for forensic scientists to determine the time at which a crime took place. The objective of this study was to determine whether attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy could be used to estimate the TSD of a bloodstain in a relatively early period (from 0 min to the time required for the bloodstain to dry out). For this purpose, we used ATR-FTIR to study the variation in absorbance at certain wavelengths as rat and human blood sample dried out. The absorbance at 3308/cm (A3308) was found to have a close correlation with the TSD during this time period, and the changes in A3308 during the drying of rat and human blood drops under the same controlled conditions showed similar results. The current study indicates that ATR-FTIR spectroscopy has potential as a tool for estimating TSD at early time periods of blood deposition.


Assuntos
Manchas de Sangue , Dessecação , Espectroscopia de Infravermelho com Transformada de Fourier , Animais , Medicina Legal , Humanos , Modelos Logísticos , Ratos Sprague-Dawley , Fatores de Tempo
18.
Fa Yi Xue Za Zhi ; 32(1): 21-5, 2016 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-27295852

RESUMO

OBJECTIVE: To analyze postmortem chemical changes in Landrace costal cartilages and ribs using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, and to provide a novel technique for estimation of postmortem interval (PMI). METHODS: The swines were sacrificed by hemorrhage and their costal cartilages and ribs were kept in 20 degrees C. The chemical analysis of the costal cartilages and ribs were performed using ATR-FTIR every 72 h. The correlation between the certain spectral parameters and PMI was also analyzed. The time-dependent changes of costal cartilages were more significant than ribs. RESULTS: There were no obvious changes for the main absorbance bands position, and some absorbance band ratios showed time-dependent changes and significant correlations with the PMI. CONCLUSION: ATR-FTIR has the ability to analyze postmortem chemical changes of the swine costal cartilages and ribs, and it can be a new method to estimate PMI based on spectroscopy.


Assuntos
Cartilagem Costal , Modelos Animais , Mudanças Depois da Morte , Costelas , Animais , Autopsia , Patologia Legal/métodos , Hemorragia , Ratos , Ratos Sprague-Dawley , Análise de Regressão , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos , Fatores de Tempo
19.
Forensic Sci Res ; 1(1): 3-13, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-30483604

RESUMO

The determination of time since death or the postmortem interval (PMI) is one of the most important and frequently asked questions in forensic medicine. Medicolegal scholars and forensic pathologists around the world have studied the estimation of PMI extensively in the past, and many novel methods and advanced technologies have now been applied in the field. For several centuries, Chinese forensic examiners have also worked on the estimation of the PMI, and there are a large number of excellent studies published in Chinese rather than in English, and these are not easily accessible or known internationally. Therefore we have conducted a review of relevant studies published by Chinese forensic scholars in the last few decades. The scope of this review is to provide a concise summary of the current progress in the estimation of PMI by Chinese forensic researchers using molecular biology, spectroscopic technology, entomological methods, energy changes, thanatochemistry and other methods.

20.
Int J Legal Med ; 128(1): 1-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23549598

RESUMO

The short tandem repeat (STR) loci used in human genetic studies are characterized by having relatively high mutation rates. In particular, to ensure an appropriate evaluation of genetic evidence in parentage and forensic analyses, it is essential to have accurate estimates of the mutation rates associated with the commonly used autosomal and sex chromosome STR loci. Differences in STR mutation rates between different ethnic groups should also be determined. Mutation data from two laboratories working with different ethnic groups were extracted from many meiotic transmissions ascertained for 15 autosomal STR loci currently used in forensic routine. Forty-five thousand and eighty-five trios were checked for the biological consistency of maternity and paternity through the analysis of a minimum of 15 loci. Mutations were scored as paternal, maternal, or ambiguous according to the most parsimonious explanation for the inconsistency, using always the least requiring hypothesis in terms of number of repeat differences. The main findings are: (a) the overall mutation rate across the 15 loci was 9.78 × 10(-4) per gamete per generation (95% CI = 9.30 × 10(-4)-1.03 × 10(-3)), and with just 48 (out of 1,587) exceptions, all of the mutations were single-step; (b) repeat gains were more frequent than losses; (c) longer alleles were found to be more mutable; and (d) the mutation rates differ at some loci between the two ethnic groups. Large worldwide meiotic transmission datasets are still needed to measure allele-specific mutation rates at the STR loci consensually used in forensic genetics.


Assuntos
Povo Asiático/genética , Cromossomos Humanos/genética , Genética Forense/métodos , Loci Gênicos/genética , Genética Populacional , Repetições de Microssatélites/genética , Mães/legislação & jurisprudência , Taxa de Mutação , Paternidade , População Branca/genética , Alelos , Brasil , China , Feminino , Frequência do Gene , Humanos , Masculino
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