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Forensic Science International Jan 2020Body fluid analysis has played a crucial role in ascertaining various characteristics and has greatly aided in reconstructing events during crime scene investigation. It...
Body fluid analysis has played a crucial role in ascertaining various characteristics and has greatly aided in reconstructing events during crime scene investigation. It is often presumed that crimes that involve violence and mental disturbances such as murder or sexual assault provide good sources of body fluids such as blood, saliva, semen, vaginal secretions, urine and tears. Tears are secreted in response to any emotional or stressful situations and may be found deposited on surfaces such as bedding, tissue paper or cloth. In the absence of the commonly noted body fluids such as blood or saliva, tears can play an important role that can lead to personal identification by examining the biochemistry and molecular aspects to obtain a full DNA profile. Additionally, identification of an individual may be done by carefully observing certain unique eye characteristics such as heterochromia which is highly individualistic. Characteristics of eyewear such as spectacles and contact lenses have unique properties and prescription criteria for correcting an individual's eyesight that can provide vital clues in understanding the visual ability of an individual. In crime scene investigation, the presence or absence of eyewear provides immense evidentiary value that has greatly aided in solving cases such as Janet Abaroa's Murder. This paper provides a systematic review of the possibility of using tears and eyewear for the purpose of forensic investigation and to statistically support the inferences with prescription databases which may be initiated across different populations. Forensic Optometry is yet to get streamlined along with the routinely followed investigative techniques and scientifically explored although no standard protocols exist to analyse eyewear. The use of behavioural optometry is gaining attention in the context of driving laws of different countries and is a simple but powerful indicator of abnormal behaviour. It is speculated that the last seen image referred to as an 'Optogram' of an individual may be captured in the retina since our eyes functions like a camera. Although this claim is considerably unexplored, it is quite possible that the last seen image of a criminal, objects or a place may be noted that can positively help in linking individuals at the scene of crime or identify the primary crime location. In this review, the potential for new insights into the analysis of tears, eye and eyewear characteristics have been explored.
Topics: Contact Lenses; DNA; DNA Fingerprinting; Databases, Factual; Epithelium, Corneal; Eye; Eye Movements; Eyeglasses; Forensic Sciences; Humans; Postmortem Changes; Prescriptions; Specimen Handling; Substance-Related Disorders; Tears; Vitreous Body
PubMed: 31785512
DOI: 10.1016/j.forsciint.2019.110055 -
European Journal of Human Genetics :... Jun 2007As sequence analysis for BRCA1 and BRCA2 mutations is both time- and cost-intensive, current strategies often include scanning techniques to identify fragments... (Review)
Review
As sequence analysis for BRCA1 and BRCA2 mutations is both time- and cost-intensive, current strategies often include scanning techniques to identify fragments containing genetic sequence alterations. However, a systematic assessment of the diagnostic accuracy has been lacking so far. Here, we report on a systematic review to assess the internal and external validity of current scanning techniques. Inclusion criteria were: controlled design, investigators blinded, and tests suitable as a scanning tool for the whole genes BRCA1 and BRCA2. Outcome parameters were sensitivity, specificity, and positive and negative predictive values compared to direct sequencing. Out of 3816 publications, 10 studies reporting on 12 methods met our inclusion criteria. The internal and external validity of most of these studies was limited. Sensitivities were reported to be 100% for enzymatic mutation detection (EMD), multiple-dye cleavase fragment length polymorphism (MD-CFLP), fluorescence-based conformation-sensitive gel electrophoresis (F-CSGE), RNA-based sequencing, restriction endonuclease fingerprinting-single strand conformation polymorphism (REF-SSCP), stop codon (SC) assay, and denaturing high-performance liquid chromatography (DHPLC). Sensitivity was 50-96% for SSCP, 88-91% for two-dimensional gene scanning (TDGS), 76% for conformation-sensitive gel electrophoresis (CSGE), 75% for protein truncation test (PTT), and 58% for micronucleus test (MNT). Specificities close to 100% were reported, except for MNT. PTT and SC assay are only able to detect truncating mutations. Most studies were designed to introduce new experimental approaches or modifications of established methods and require further evaluation. F-CSGE, REF-SSCP, RNA-based sequencing, EMD, and MD-CFLP will need further evaluation before their use in a routine setting can be considered. SSCP, MNT, PTT, CSGE, and TDGS cannot be recommended because of their low sensitivity. DHPLC outperforms all other methods studied. However, none of the four studies evaluating DHPLC was performed on BRCA2.
Topics: Apoptosis Regulatory Proteins; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Chromatography, High Pressure Liquid; DNA Mutational Analysis; Female; Genetic Techniques; Humans; Micronucleus Tests; Mutation; Nucleic Acid Denaturation; Polymorphism, Single-Stranded Conformational; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity; Sequence Analysis, RNA
PubMed: 17342152
DOI: 10.1038/sj.ejhg.5201806 -
Forensic Science International Nov 2017Molecular analyses in a post-mortem setting are becoming increasingly common, particularly in cases of sudden unexplained death, with the aim of identifying genetic... (Review)
Review
Molecular analyses in a post-mortem setting are becoming increasingly common, particularly in cases of sudden unexplained death, with the aim of identifying genetic mutations which may be responsible for causing death. In retrospective investigations, the access to suitable autopsy biological samples may be limited, and often formalin fixed paraffin embedded (FFPE) tissue is the only sample available. The preservation of tissue in formalin is known to damage DNA through crosslinking activity. This results in the extraction of severely fragmented DNA of variable yields, which subsequently reduces the ability to perform downstream molecular analyses. Numerous studies have investigated possible improvements to various aspects of the DNA extraction and amplification procedures from FFPE tissue and this review aims to collate these optimization steps in a cohesive manner. A systematic review was performed of three major databases, which identified 111 articles meeting the inclusion criteria. Five main areas for optimization and improvements were identified in the workflow: (1) tissue type, (2) fixation process, (3) post-fixation, (4) DNA extraction procedure and (5) amplification. It was found that some factors identified, for example tissue type and fixation process, could not be controlled by the researcher when conducting retrospective analyses. For this reason, optimization should be performed in other areas, within the financial means of the laboratories, and in accordance with the purposes of the investigation. Implementation of one or more of the optimization measures described here is anticipated to assist in the extraction of higher quality DNA. Despite the challenges posed by FFPE tissue, it remains a valuable source of DNA in retrospective molecular forensic investigations.
Topics: DNA; DNA Fingerprinting; Fixatives; Forensic Medicine; Formaldehyde; Humans; Paraffin Embedding; Polymerase Chain Reaction; Preservation, Biological
PubMed: 29078160
DOI: 10.1016/j.forsciint.2017.09.020 -
BMC Infectious Diseases Jun 2010Invasive meningococcal disease (IMD), is a widely distributed, complex human disease affecting all age categories. The causative agent, Neisseria meningitidis, is spread... (Review)
Review
BACKGROUND
Invasive meningococcal disease (IMD), is a widely distributed, complex human disease affecting all age categories. The causative agent, Neisseria meningitidis, is spread through aerosol respiratory droplets. 13 different serogroups have been identified, each with varying epidemiological features including prevalence, virulence, immunogenicity, geographical and temporal distribution. Although preventative measures are available for several of the serogroups, meningococcal disease caused by serogroup B is of particular interest due to the challenge it presents concerning vaccine development.
METHODS
A systematic review of peer reviewed studies and reports, the collection of data from national and international health resources, along with the analysis of the Multi Locus Sequence Typing database was carried out aimed at collecting information concerning serogroup B IMD and the epidemiology attached to it.
RESULTS
A continuous output of related and novel STs occurring worldwide in terms of the hypervirulent clonal complexes was observed both in published studies and the MLST database in this case using the eburst software, which highlights the genetically diverse nature of serogroup B strains.
CONCLUSIONS
With the recent dominance of serogroup B IMD seen in many countries, along with the presence of antibiotic resistance, vaccine development needs to target areas of the bacterium which tackle this widespread and heterogeneous aspect of meningococcal meningitis disease.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Typing Techniques; Child; Child, Preschool; Cluster Analysis; DNA Fingerprinting; Drug Resistance, Bacterial; Genotype; Humans; Infant; Infant, Newborn; Meningitis, Meningococcal; Middle Aged; Neisseria meningitidis, Serogroup B; Young Adult
PubMed: 20565757
DOI: 10.1186/1471-2334-10-175 -
The International Journal of... May 2008Many molecular epidemiology studies have been conducted to identify risk factors for clustering of tuberculosis (TB) cases in the population. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Many molecular epidemiology studies have been conducted to identify risk factors for clustering of tuberculosis (TB) cases in the population.
OBJECTIVE
To estimate the impact of commonly investigated risk factors on TB clustering.
METHODS
Ten electronic databases were searched up to January 2006 along with a hand search of the International Journal of Tuberculosis and Lung Disease and bibliographies of review articles. Meta-analyses of odds ratios (ORs) for various risk factors were conducted using random effect models, stratified by TB incidence. Meta-regressions were employed to account for the heterogeneity in clustering proportions and the magnitudes of risk.
FINDINGS
The TB clustering proportion varied greatly (7.0-72.3%) among 36 studies in 17 countries. In multiple meta-regression analyses, high TB incidence, mean cluster size and conventional contact tracing were significantly associated with higher clustering. The pooled ORs (95%CIs) for low and high/intermediate TB incidence studies, using a cut off of 25/100000 per year, were 3.4 (2.7- 4.2) and 1.6 (1.3-2.1) for local-born status, 1.6 (1.5-1.7) and 1.7 (1.3-2.2) for pulmonary TB and 1.2 (1.1-1.3) and 1.3 (1.1-1.7) for smear-positive cases, respectively. Male sex, local birth, alcohol abuse and injection drug use were significantly higher risks in low TB incidence studies than in the high/intermediate ones.
INTERPRETATION
Meta-analyses yielded significant estimates of ORs for several risk factors across both levels of TB incidence. Alcohol abuse, injection drug use and homelessness--all characteristics of marginalized populations--were found to be consistently significant in populations of low TB incidence. More research is needed to better understand TB transmission dynamics in high-burden countries.
Topics: Cluster Analysis; DNA Fingerprinting; Global Health; Humans; Incidence; Mycobacterium tuberculosis; Regression Analysis; Risk Factors; Tuberculosis
PubMed: 18419882
DOI: No ID Found -
Frontiers in Cellular and Infection... 2021Osseointegration is a well-established concept used in applications including the percutaneous Bone-Anchored Hearing System (BAHS) and auricular rehabilitation. To date,...
Multimodal Analysis of the Tissue Response to a Bone-Anchored Hearing Implant: Presentation of a Two-Year Case Report of a Patient With Recurrent Pain, Inflammation, and Infection, Including a Systematic Literature Review.
Osseointegration is a well-established concept used in applications including the percutaneous Bone-Anchored Hearing System (BAHS) and auricular rehabilitation. To date, few retrieved implants have been described. A systematic review including cases where percutaneous bone-anchored implants inserted in the temporal bone were retrieved and analyzed was performed. We also present the case of a patient who received a BAHS for mixed hearing loss. After the initial surgery, several episodes of soft tissue inflammation accompanied by pain were observed, leading to elective abutment removal 14 months post-surgery. Two years post-implantation, the implant was removed due to pain and subjected to a multiscale and multimodal analysis: microbial DNA using molecular fingerprinting, gene expression using quantitative real-time polymerase chain reaction (qPCR), X-ray microcomputed tomography (micro-CT), histology, histomorphometry, backscattered scanning electron microscopy (BSE-SEM), Raman spectroscopy, and fluorescence hybridization (FISH). Evidence of osseointegration was provided micro-CT, histology, BSE-SEM, and Raman spectroscopy. Polymicrobial colonization in the periabutment area and on the implant, including that with and , was determined using a molecular analysis a 16S-23S rDNA interspace [IS]-region-based profiling method (IS-Pro). The histology suggested bacterial colonization in the skin and in the peri-implant bone. FISH confirmed the localization of and coagulase-negative staphylococci in the skin. Ten articles (54 implants, 47 patients) met the inclusion criteria for the literature search. The analyzed samples were either BAHS (35 implants) or bone-anchored aural epitheses (19 implants) between 2 weeks and 8 years. The main reasons for elective removal were nonuse/changes in treatment, pain, or skin reactions. Most samples were evaluated using histology, demonstrating osseointegration, but with the absence of bone under the implants' proximal flange. Taken together, the literature and this case report show clear evidence of osseointegration, despite prominent complications. Nevertheless, despite implant osseointegration, chronic pain related to the BAHS may be associated with a chronic bacterial infection and raised inflammatory response in the absence of macroscopic signs of infection. It is suggested that a multimodal analysis of peri-implant health provides possibilities for device improvements and to guide diagnostic and therapeutic strategies to alleviate the impact of complications.
Topics: Bone-Anchored Prosthesis; Hearing; Hearing Aids; Humans; In Situ Hybridization, Fluorescence; Inflammation; Pain; Staphylococcus aureus; X-Ray Microtomography
PubMed: 33859952
DOI: 10.3389/fcimb.2021.640899 -
BMC Infectious Diseases May 2020The burden of drug resistant tuberculosis in Africa is largely driven by the emergence and spread of multidrug resistant (MDR) and extensively drug resistant (XDR)...
BACKGROUND
The burden of drug resistant tuberculosis in Africa is largely driven by the emergence and spread of multidrug resistant (MDR) and extensively drug resistant (XDR) Mycobacterium tuberculosis strains. MDR-TB is defined as resistance to isoniazid and rifampicin, while XDR-TB is defined as MDR-TB with added resistance to any of the second line injectable drugs and any fluoroquinolone. The highest burden of drug resistant TB is seen in countries further experiencing an HIV epidemic. The molecular mechanisms of drug resistance as well as the evolution of drug resistant TB strains have been widely studied using various genotyping tools. The study aimed to analyse the drug resistant lineages in circulation and transmission dynamics of these lineages in Africa by describing outbreaks, nosocomial transmission and migration. Viewed as a whole, this can give a better insight into the transmission dynamics of drug resistant TB in Africa.
METHODS
A systematic review was performed on peer reviewed original research extracted from PubMed reporting on the lineages associated with drug resistant TB from African countries, and their association with outbreaks, nosocomial transmission and migration. The search terms "Tuberculosis AND drug resistance AND Africa AND (spoligotyping OR molecular epidemiology OR IS6110 OR MIRU OR DNA fingerprinting OR RFLP OR VNTR OR WGS)" were used to identify relevant articles reporting the molecular epidemiology of drug resistant TB in Africa.
RESULTS
Diverse genotypes are associated with drug resistant TB in Africa, with variations in strain predominance within the continent. Lineage 4 predominates across Africa demonstrating the ability of "modern strains" to adapt and spread easily. Most studies under review reported primary drug resistance as the predominant type of transmission. Drug resistant TB strains are associated with community and nosocomial outbreaks involving MDR- and XDR-TB strains. The under-use of molecular epidemiological tools is of concern, resulting in gaps in knowledge of the transmission dynamics of drug resistant TB on the continent.
CONCLUSIONS
Genetic diversity of M. tuberculosis strains has been demonstrated across Africa implying that diverse genotypes are driving the epidemiology of drug resistant TB across the continent.
Topics: Africa; Antitubercular Agents; Drug Resistance, Multiple, Bacterial; Epidemics; Extensively Drug-Resistant Tuberculosis; Genotype; High-Throughput Nucleotide Sequencing; Humans; Molecular Epidemiology; Mycobacterium tuberculosis; Polymorphism, Restriction Fragment Length
PubMed: 32404119
DOI: 10.1186/s12879-020-05031-5 -
Nutrients Aug 2017The mechanisms behind the efficacy of exclusive enteral nutrition (EEN) in Crohn's disease (CD) remain poorly understood, despite the high rate of treatment response.... (Review)
Review
The mechanisms behind the efficacy of exclusive enteral nutrition (EEN) in Crohn's disease (CD) remain poorly understood, despite the high rate of treatment response. Evidence accumulated in the last 20 years suggests that a positive shift of the disrupted microbiota is one of the treatment effects. The purpose of this study was to critically review and summarize data reporting the microbiological effects of EEN in patients with CD. Fourteen studies were considered in the review, overall involving 216 CD patients on EEN. The studies were heterogeneous in methods of microbiota analysis and exclusion criteria. The most frequently reported effect of EEN was a reduction in microbiota diversity, reversible when patients returned to a normal diet. The effect of EEN on specific bacteria was very variable in the different studies, partially due to methodological limitations of the mentioned studies. The EEN seem to induce some metabolomic changes, which are different in long-term responder patients compared to patients that relapse earlier. Bacterial changes can be relevant to explaining the efficacy of EEN; however, microbiological data obtained from rigorously performed studies and derived from last generation techniques are largely inconsistent.
Topics: Bacteria; Crohn Disease; Enteral Nutrition; Gastrointestinal Microbiome; Humans; Intestines; Ribotyping; Treatment Outcome
PubMed: 28777338
DOI: 10.3390/nu9080832 -
Acta Dermato-venereologica Jan 2019The immune mechanisms involved in atopic dermatitis (AD) are complex and little is known about the possible role of the gut microbiota in the aetiopathogenesis of AD. A...
The immune mechanisms involved in atopic dermatitis (AD) are complex and little is known about the possible role of the gut microbiota in the aetiopathogenesis of AD. A systematic review of the literature was performed according to PRISMA guidelines, and included 44 of 2,199 studies (26 observational and 18 interventional studies). Detection of gut microbiota was performed by either 16s rRNA PCR, or by culture. Observational studies were diverse regarding the age of study participants and the bacterial species investigated. Overall, the results were conflicting with regard to diversity of the gut microbiota, specific bacterial colonization, and subsequent risk of AD. Nearly half of the included interventional studies showed that an altered gut microbial colonization due to use of probiotics had a positive effect on the severity of AD. The remaining studies did not show an effect of probiotics on the severity of AD despite an alteration in the gut microbial composition. The role of the gut microbiome for the onset and severity of pre-existing AD remains controversial.
Topics: Bacteria; Dermatitis, Atopic; Gastrointestinal Microbiome; Gastrointestinal Tract; Host-Pathogen Interactions; Humans; Probiotics; Ribotyping; Risk Factors; Severity of Illness Index
PubMed: 30085318
DOI: 10.2340/00015555-3008 -
Journal of Plastic, Reconstructive &... Jan 2019We present a case of skin allograft survival in a patient who previously received a bone marrow transplant from the same HLA-matched donor. DNA fingerprinting of skin...
BACKGROUND
We present a case of skin allograft survival in a patient who previously received a bone marrow transplant from the same HLA-matched donor. DNA fingerprinting of skin biopsies showed mixed cellularity originating from the donor and recipient (68% and 32% donor DNA in the allograft skin and the native recipient's skin, respectively). Histologic sections demonstrated both grade 3/4 rejection and graft-versus-host-disease. We have conducted a systematic review in search for other cases of donor skin allograft survival after a bone marrow or hematopoietic stem cell transplantation.
METHODS
All reported cases in English, Spanish, French, and German were captured using the electronic databases. Bibliographies of relevant articles were manually searched.
RESULTS
Nineteen patients (12 females) who received skin allografts from their bone marrow or hematopoietic stem cell donors were identified. Average age was 27.2 years (range: 5 months to 64 years). Skin allografts were used to treat graft-versus-host-disease, Herlitz junctional epidermolysis bullosa, and to test tolerance before a kidney transplantation from the same donor. Eight cases were not receiving immunosuppressive therapy. Allografts survived in all patients. In three patients, skin punch biopsies were taken, and these biopsies demonstrated mixed donor and recipient cellularity. The pathology result is specified in two more cases, with no signs of rejection.
CONCLUSIONS
The same donor skin allografts may be a safe option to treat severe cutaneous conditions in recipients of a bone marrow/hematopoietic stem cell transplantation. However, future studies are needed to confirm these results.
Topics: Adolescent; Adult; Allografts; Bone Marrow Transplantation; Child; Child, Preschool; Escherichia coli Infections; Fasciitis, Necrotizing; Fatal Outcome; Female; Graft Survival; Graft vs Host Disease; Humans; Infant; Living Donors; Male; Middle Aged; Skin Transplantation; Transplant Donor Site; Transplantation, Homologous; Wound Healing; Young Adult
PubMed: 29983364
DOI: 10.1016/j.bjps.2018.05.018