Publications by authors named "Helen Konrad"

The identification of the type of body fluid in crime scene evidence may be crucial, so that the efforts are high to reduce the complexity of these analyses and to minimize time and costs. Reliable immunochromatographic rapid tests for specific and sensitive identification of blood, saliva, urine and sperm secretions are already routinely used in forensic genetics. The recently introduced Seratec® PMB test is said to detect not only hemoglobin, but also differentiate menstrual blood from other secretions containing blood (cells) by detecting D-dimers.

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The determination of cellular origin of DNA is a useful method in forensic genetics and complements identification of the DNA donor by STR analysis, since it could provide helpful information for the reconstruction of crime scenes and verify or disprove the descriptions of involved people. There already exist several rapid/pre-tests for several secretions (blood, sperm secretion, saliva, and urine), RNA-based expression analyses (blood, menstrual blood, saliva, vaginal secretion, nasal secretion, and sperm secretion), or specific CpG methylation analyses (nasal blood, blood, saliva, vaginal secretion, nasal secretion, and sperm secretion) for determining the cell type.To identify and to discriminate seven different body fluids and mixtures thereof in a simple workflow from each other, assays based on specific methylation patterns at several CpGs combined with pre-/rapid tests were set up in this study.

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Secretion analysis is a useful tool in forensic genetics, since it establishes the (cellular) origin of the DNA prior in addition to the identification of the DNA donor. This information can be crucial for the construction of the crime sequence or verification of statements of people involved in the crime. For some secretions, rapid/pretests already exist (blood, semen, urine, and saliva) or can be determined via published methylation analyses or expression analyses (blood, saliva vaginal secretions, menstrual blood, and semen).

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DNA persistence and DNA transfer are important features in the assessment of a crime scene. The question how long DNA may persist at a certain location is similarly important as the one how the DNA has been transferred to this location. Depending on the source of the DNA as well as the conditions at the crime scene, the answer to this question is quite difficult.

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Since methylation analysis has become an important tool in forensic genetics, the reliability and credibility of the method must be ensured. After a successful validation and establishment of several pyrosequencing assays using a PyroMark® Q48 Autoprep instrument (Qiagen, Hilden, Germany), we decided to expand the method further purchasing a second instrument. But after initializing this second instrument side by side with the first, the majority of analyses failed (97 samples of 133 samples (73%)).

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The detection of DNA of a certain person on the inside of a piece of clothing involved in a crime scene is usually seen as confirmation that this person is the owner or bearer and therefore participated in this crime. However, besides the possibilities of secondary or even tertiary transfer of DNA, the accused often argues that he lent the garment to another person who by chance did not leave any DNA while committing the crime. Then, forensic genetic scientists have to answer the question how long DNA persists on an item used in daily routine and how long a piece of clothing must be worn to definitively leave detectable DNA behind.

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DNA quantification is an important step in the molecular genetic analysis of a forensic sample, hopefully providing reliable data on DNA content for a subsequent generation of reproducible STR profiles for identification. For several years, this quantification has usually been done by real-time PCR protocols and meanwhile a variety of assays are commercially available from different companies. The newest one is the PowerQuant(TM) assay by Promega Inc.

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In this report of our 3-yr protocol biopsy program, we describe the evolution of acute rejection (AR) and chronic renal allograft nephropathy (CAN) in a cohort of 21 children treated with antibody induction, tacrolimus, mycophenolate mofetil, and prednisone. The aims of this study were to compare the pathogenicity of clinical acute rejection (CAR) and subclinical acute rejection (SAR), and to determine whether functional studies accurately represent acute and chronic renal allograft pathology in pediatric recipients with disproportionately large grafts. Using concurrent biopsies, we evaluated: (i) the utility of changes in the baseline sCr (DeltasCr) to predict both the onset of AR and the response to immunosuppressive therapy; and (ii) the relationship of the calculated creatinine clearance and the presence of pathologic proteinuria to the severity of CAN.

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