| 1. |
- Andréasson, Hanna, et al.
(författare)
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Quantification of mtDNA mixtures in forensic evidence material using pyrosequencing
- 2006
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Ingår i: International journal of legal medicine. - : Springer Science and Business Media LLC. - 0937-9827 .- 1437-1596. ; 120:6, s. 383-390
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of mtDNA variation using Sanger sequencing does not allow accurate quantification of the components of mtDNA mixtures. An alternative method to determine the specific mixture ratios in samples displaying heteroplasmy, consisting of DNA contributions from several individuals, or containing contamination would therefore be valuable. A novel quantification system for mtDNA mixture analysis has been developed based on pyrosequencing technology, in which the linear relationship between incorporated nucleotides and released light allows quantification of the components of a sample. Within five polymerase chain reaction fragments, seven variable positions in the mtDNA control and coding region were evaluated using this quantification analysis. For all single nucleotide polymorphisms quantified in this study, a linear relationship was observed between the measured and expected mixture ratios. This mtDNA quantification assay is an easy to use, fast and accurate quantification system, with the ability to resolve and interpret major and minor mtDNA components in forensic mixture samples.
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| 2. |
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| 3. |
- Ceciliason, Ann-Sofie, 1971-, et al.
(författare)
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Histological quantification of decomposed human livers : a potential aid for estimation of the post-mortem interval?
- 2021
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Ingår i: International journal of legal medicine. - : Springer Nature. - 0937-9827 .- 1437-1596. ; 135:1, s. 253-267
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to determine if a novel scoring-based model for histological quantification of decomposed human livers could improve the precision of post-mortem interval (PMI) estimation for bodies from an indoor setting. The hepatic decomposition score (HDS) system created consists of five liver scores (HDS markers): cell nuclei and cell structure of hepatocytes, bile ducts, portal triad, and architecture. A total of 236 forensic autopsy cases were divided into a training dataset (n = 158) and a validation dataset (n = 78). All cases were also scored using the total body score (TBS) method. We specified a stochastic relationship between the log-transformed accumulated degree-days (log10ADD) and the taphonomic findings, using a multivariate regression model to compute the likelihood function. Three models were applied, based on: (i) five HDS markers, (ii) three partial body scores (head, trunk, limbs), or (iii) a combination of the two. The predicted log10ADD was compared with the true log10ADD for each case. The fitted models performed equally well in the training dataset and the validation dataset. The model comprising both scoring methods had somewhat better precision than either method separately. Our results indicated that the HDS system was statistically robust. Combining the HDS markers with the partial body scores resulted in a better representation of the decomposition process and might improve PMI estimation of decomposed human remains.
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| 4. |
- Ceciliason, Ann-Sofie, et al.
(författare)
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Microbial neoformation of volatiles : implications for the estimation of post-mortem interval in decomposed human remains in an indoor setting
- 2021
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Ingår i: International journal of legal medicine. - : Springer Nature. - 0937-9827 .- 1437-1596. ; 135:1, s. 223-233
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to determine if a relationship between microbial neoformation of volatiles and the post-mortem interval (PMI) exists, and if the volatiles could be used as a tool to improve the precision of PMI estimation in decomposed human remains found in an indoor setting. Chromatograms from alcohol analysis (femoral vein blood) of 412 cases were retrospectively assessed for the presence of ethanol, N-propanol, 1-butanol, and acetaldehyde. The most common finding was acetaldehyde (83% of the cases), followed by ethanol (37%), N-propanol (21%), and 1-butanol (4%). A direct link between the volatiles and the PMI or the degree of decomposition was not observed. However, the decomposition had progressed faster in cases with microbial neoformation than in cases without signs of neoformation. Microbial neoformation may therefore act as an indicator of the decomposition rate within the early decomposition to bloating stages. This may be used in PMI estimation based on the total body score (TBS) and accumulated degree days (ADD) model, to potentially improve the model's precision.
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| 5. |
- Ceciliason, Ann-Sofie, et al.
(författare)
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Mummification in a forensic context : an observational study of taphonomic changes and the post-mortem interval in an indoor setting
- 2023
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Ingår i: International journal of legal medicine. - : Springer Nature. - 0937-9827 .- 1437-1596. ; 137:4, s. 1077-1088
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to evaluate the presence of mummification in an indoor setting, with an emphasis on the forensic perspective. A dataset of 102 forensic autopsy cases was assessed for distribution of desiccation of skin and soft tissue (i.e., subcutaneous fat and musculature) and for moist decompositional (i.e., putrefactive) changes. Further, possible correlation with the post-mortem interval (PMI) was evaluated, as well as the effects of clothing coverage of the body. The results indicated that yellow to orange parchment-like desiccated skin was found at significantly shorter PMIs than reddish brown to black leathery desiccated skin, even when soft tissue desiccation was included in the comparative analysis. Clothing appeared to have a significant decelerating effect on the extent of desiccation on the legs, but findings in regard to whole body or torso/arms were inconclusive. A large variation in PMIs was evident as regards fully desiccated skin (PMI 18-217 days), indicating difficulties in PMI estimation due to a variable repressive effect on the decompositional process per se in an indoor setting. For the specific case in forensic practice, no definite conclusion can be drawn from the observed desiccation changes to the PMI. One way forward might be creating a systematic and standardized method for describing different desiccation types, as well as other cooccurring decompositional changes and how they relate to the PMI, as a foundation for a future quantification model.
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| 6. |
- Dorum, Guro, et al.
(författare)
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Mixtures with relatives and linked markers
- 2016
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Ingår i: International journal of legal medicine. - : SPRINGER. - 0937-9827 .- 1437-1596. ; 130:3, s. 621-634
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Tidskriftsartikel (refereegranskat)abstract
- Mixture DNA profiles commonly appear in forensic genetics, and a large number of statistical methods and software are available for such cases. However, most of the literature concerns mixtures where the contributors are assumed unrelated and the genetic markers are unlinked. In this paper, we consider mixtures of linked markers and related contributors. If no relationships are involved, linkage can be ignored. While unlinked markers can be treated independently, linkage introduces dependencies. The use of linked markers presents statistical and computational challenges, but may also lead to a considerable increase in power since the number of markers available is much larger if we do not require the markers to be unlinked. In addition, some cases that cannot be solved with an unlimited number of unlinked autosomal markers can be solved with linked markers. We focus on two special cases of linked markers: pairs of linked autosomal markers and X-chromosomal markers. A framework is presented for calculation of likelihood ratios for mixtures with general relationships and with linkage between any number of markers. Finally, we explore the effect of linkage disequilibrium, also called allelic association, on the likelihood ratio.
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| 7. |
- Edston, Erik, 1948-, et al.
(författare)
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Death in anaphylaxis in a man with house dust mite allergy
- 2003
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Ingår i: International journal of legal medicine. - : Springer Science and Business Media LLC. - 0937-9827 .- 1437-1596. ; 117:5, s. 299-301
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Tidskriftsartikel (refereegranskat)abstract
- Up to recently the post-mortem diagnosis of anaphylaxis has been based solely on circumstantial evidence. With the development of assays for mast cell tryptase it is now possible to verify cases of suspected anaphylaxis. Here we present one such case, which initially appeared to be due to sudden death of unknown cause. A 47-year-old farmer was found dead in his bathroom around midnight. Hospital records revealed that he had previously been diagnosed with an allergy to house dust mites. He had also had infrequent episodes of airway symptoms, nausea, hypotension and diarrhoea usually after going to bed. The forensic autopsy did not give any clue to the cause of death. Serum tryptase in post-mortem blood was found to be substantially elevated in two samples (170 and >200 ╡g/L). Analysis of allergen-specific IgE showed high values for Dermatophagoides pteronyssinus and farinae. High mite allergen levels were found in dust obtained from the patient's mattress. The results of the immunological tests support the assumption that he died of anaphylactic shock. The circumstances and the patient's history of previous attacks after going to bed point to the fact that exposure to mite contaminated food and/or exposure to mite allergens in bed might have caused his death.
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| 8. |
- Edston, Erik, et al.
(författare)
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Histiocytoid cardiomyopathy and ventricular non-compaction in a case of sudden death in a female infant
- 2009
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Ingår i: International journal of legal medicine. - : Springer Science and Business Media LLC. - 0937-9827 .- 1437-1596. ; 123:1, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- A case of sudden infant death with histiocytoid cardiomyopathy and ventricular non-compaction was investigated with immunohistochemical methods. Histiocytoid cardiomyopathy is thought to be a developmental defect of the cardiomyocytes of the conduction system. In contrast to mature cardiomyocytes, the histiocytoid cells showed only weak reactions to desmin and myosin antibodies. They lacked cross-striation but reacted strongly to enolase and myoglobin antibodies. The protein Pax-7, seen only in cells undergoing differentiation, and the proliferation marker Ki-67 were not expressed in the histiocytoid cells. In areas of altered myocardium, clusters of CD4-, CD8-, and CD68-positive inflammatory cells were seen as well an abundance of mast cells. With the TUNEL method, it was found that many of the histiocytoid cells were undergoing apoptosis. Our results confirm that the histiocytoid cells are defective cardiomyocytes. The apoptotic and inflammatory changes point to a degenerative process rather than defective maturation of cardiomyocytes as has been suggested in some earlier studies. Ventricular non-compaction is a developmental defect of the subendocardial tissue with hypertrabeculation and weak development of the papillary muscles. Only one case combined with histiocytoid cardiomyopathy has been described previously. A causal connection between the two conditions cannot be established until more cases have been analyzed.
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| 9. |
- Edston, Erik, et al.
(författare)
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Mast cell tryptase in postmortem serum - Reference values and confounders
- 2007
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Ingår i: International journal of legal medicine. - : Springer Science and Business Media LLC. - 0937-9827 .- 1437-1596. ; 121:4, s. 275-280
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the effects of some factors suspected of inducing spuriously increased tryptase concentrations, specifically sampling site, conjunctival petechial bleeding and prone position at the time of death as indicators of premortem asphyxia, and resuscitation efforts by external cardiac massage. Tryptase was measured in blood from the femoral vein in 60 deaths: 39 control cases who died rapidly (within minutes) from natural causes (sudden cardiac death and acute aortic dissection), 16 with death caused by prolonged asphyxia (traumatic compression of the chest and suffocation due to body position or smothering), and five anaphylactic deaths. In 44 of these cases, tryptase was measured in both heart and femoral blood. Mast cell tryptase was analyzed with a commercial FEIA method (Pharmacia Diagnostics AB, Uppsala, Sweden) measuring both a- and ß-tryptase. Assuming that tryptase values in the control group were gamma distributed, we calculated the upper normal limits for tryptase concentrations in femoral blood. It was found that 95% of the controls had values below 44.3 µg/l (femoral blood), SD 5.27 µg/l. All but one of the anaphylactic deaths had tryptase concentrations exceeding that limit. Tryptase was significantly elevated in femoral blood from anaphylactic deaths (p<0.007), compared with the controls. Also, in the cases where death had occurred due to asphyxia tryptase was elevated in femoral blood (p<0.04). A significant difference in tryptase concentrations was seen between blood from the heart and the femoral vessels (p<0.02) in the whole material (n=44). Tryptase concentrations in femoral blood were not influenced by prone position at death, or resuscitation efforts. It is concluded that asphyxia premortem seems to affect tryptase concentrations, that postmortem tryptase measurements should be done in serum from femoral blood, and that the normal upper limit, covering 95%, is 44.3 µg/l. © 2006 Springer-Verlag.
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| 10. |
- Edston, Erik, et al.
(författare)
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TUNEL : A useful screening method in sudden cardiac death
- 2002
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Ingår i: International journal of legal medicine. - : Springer Science and Business Media LLC. - 0937-9827 .- 1437-1596. ; 116:1, s. 22-26
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Tidskriftsartikel (refereegranskat)abstract
- The primary objective of this study was to investigate if detection of apoptosis in the heart can be used to diagnose early myocardial ischaemia. The material consisted of myocardial tissue from autopsy cases: 10 cases with occlusive, thrombotic coronary artery disease and acute myocardial infarction, 10 cases of sudden cardiac death without coronary artery disease (CAD) and 8 controls without cardiovascular disease and with known causes of death. Necrotic changes in the myocardium were detected with hematoxylin-erythrosin-saffron, Mallory's PTAH stain and with antibodies against complement 9. Apoptotic nuclei were visualised with two different kits using the terminal deoxynucleotidyl transferase-mediated desoxyuridinetriphosphate nick end-labeling (TUNEL) method on histological sections. In the patients with CAD, early myocardial infarction was found in one defined area of the ventricular wall, apoptotic myocyte nuclei were observed not in the necrotic lesions, but evenly spread usually without a gradient, all over the myocardium with a mean number per high power field of 29% (range 3-56%) of the total number of myocyte nuclei. In the sudden cardiac deaths without CAD, necrosis was scarce and distributed both focally and irregularly in both the left and right ventricular walls. With few exceptions, the percentage of apoptotic myocyte nuclei exceeded 20% in all sections (mean 24%, range 0-68%). No difference was seen between patients with CAD and those without CAD (p > 0.05). With the TUNEL method, positively stained nuclei were seen very early and extensively all over the myocardium. It is not certain that they represent true apoptosis induced by ischemia, but TUNEL appears to be a useful screening method in cases where sudden cardiac death is suspected.
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