PubMed Health⌕ Search

Biomedical subjects

M Steinlechner

Publications and source records attributed to M Steinlechner.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of an extended set of 15 candidate STR loci for paternity and kinship analysis in an Austrian population sample.

We investigated 15 polymorphic short tandem repeat (STR) loci (D1S1656, D7S1517, D8S306, D8S639, D9S304, D10S2325, D11S488, D12S391, D14S608, D16S3253, D17S976, D18S1270, D19S253, D20S161, and D21S1437) which are not included in the standard sets of forensic loci. The markers were selected according to the complexity of the polymorphic region: Of the 15 investigated loci, 7 loci showed a simple repeat structure (D9S304, D10S2325, D14S608, D16S3253, D18S1270, D19S253, and D21S1437), 3 loci (D7S1517, D12S391, and D20S161) consisted of compound repeat units, and 5 loci (D1S1656, D8S306, D8S639, D11S488, and D17S976) showed a more complex polymorphic region partly including different repeat blocks and incomplete repeat units, which resulted in a relatively high proportion of intermediate alleles. A population study on a sample of 270 unrelated persons from Austria was carried out. We did not observe significant deviations from Hardy-Weinberg expectations. The combined probability of exclusion for the 15 loci was 0.99999998. In combination with the conventional set of STR markers included in commercially available kits (no linkage was observed between these 15 loci and the Powerplex 16 System loci), these markers are approved as highly discriminating forensic tools, also suitable for the analysis of difficult paternity and kinship constellations.

Adolescent↗
PubMed2003

Scapholunate ligament reconstruction using a periosteal flap of the iliac crest: a biomechanical study.

INTRODUCTION: Advances continue to improve direct reconstruction of the dorsal scapholunate (SL) ligament, which is the strongest part of the entire SL ligament and is known as the turning point between the scaphoid and lunate. This study was designed to compare the biomechanical properties of the dorsal SL ligament with those of a periosteal flap of the iliac crest, which is a new graft candidate for dorsal SL reconstruction. MATERIALS AND METHODS: A bone-ligament-bone complex was harvested for biomechanical testing from the iliac crest and the dorsal SL complex. Ten specimens could be prepared in each group. After potting the bone blocks in methylmethacrylate for stable fixation, the specimens were tested, using a servohydraulic testing system, at a rate of 10 mm/min. RESULTS: Failure displacement, failure force, failure stress, energy to failure, and stiffness were assessed for both groups. Eight specimens in each group were tested successfully. In the ligament group, six specimens failed at the ligament level, whereas two failed at the insertion of the scaphoid. In the periosteum group, all eight specimens failed at the ligament level. The failure force of the dorsal SL ligament averaged 171.8 N, failure stress was 10.3 N/mm2, and failure displacement amounted to 2.9 mm. Energy to failure was 269.1 N-mm, and stiffness averaged 77.2 N/mm. Failure force of the periosteal flap amounted to 144.3 N, failure stress was 9.9 N/mm2, failure displacement was 3.0 mm, and energy to failure was 217.9 N-mm. Stiffness of the periosteal flap measured 60.5 N/mm. Comparison of the dorsal SL ligament and the periosteal flap of the iliac crest revealed no significant biomechanical differences. CONCLUSION: Therefore, the biomechanical properties of the periosteal flap recommend its use for reconstruction of the dorsal SL ligament.

Biomechanical Phenomena↗
PubMed2002

Rare failures in the amelogenin sex test.

Determination of sex using the amelogenin sex test is well established in the forensic field especially for casework and DNA databasing purposes. The sex test is part of commercially available PCR kits. Among 29,432 phenotypic male individuals stored in the Austrian National DNA database, 6 individuals were found to lack the amelogenin Y-specific PCR product which was confirmed using alternative amelogenin primers. The amplification of eight Y-chromosomal STR markers resulted in full profiles in five out of the six samples, one sample failed to amplify Y-STRs at all. The amplification of a fragment of the SRY gene gave positive results in all six samples, confirming the male phenotype of the individuals. The observed failure rate of the amelogenin sex test was 0.018% in this study.

Amelogenin↗
PubMed2002

Gabon black population data on the ten short tandem repeat loci D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01 and FGA.

Allele frequencies for ten short tandem repeat (STR) loci D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01 and FGA were determined in a Black African sample population from Gabon. All loci were highly polymorphic and except for TH01, D21S11 and D16S539, all met Hardy-Weinberg expectations. There was little evidence of association of alleles between the loci in this database. The combined power of exclusion for the ten STR loci was 0.999981. While significant differences between the Gabon population and the Austrian Caucasian population were found at all loci, significant differences were found between the Gabon population and Zimbabweans only for D3S1358 and between the Gabon population and African Americans only for TH01 and D8S1179.

Black People↗
PubMed2001

Efficient DNA database laboratory strategy for high through-put STR typing of reference samples.

DNA intelligence databases were installed successfully in various countries during the past few years. It is a general trend that laboratories performing STR analysis for DNA databases have to adjust to increased sample through-put, especially when dealing with a high number of reference samples. In contrast to routine forensic casework analysis, where samples of suspects and unknown samples are interpreted with regard to the specific circumstances of the case and are kept distinctly apart from other cases, DNA databases consist of single, primarily unlinked DNA profiles. Problems areas associated with the high number of anonymous DNA profiles are the risk of logistic errors, such as sample mix-up during the laboratory procedure, and the risk of typing errors during manual transcription of data and/or results. Thus, DNA databases clearly require new laboratory strategies to rise to the challenge. This paper presents an efficient automated laboratory strategy on the platform of a laboratory management information system (LIMS) with the Austrian DNA Intelligence Database as example. Two goals were tackled in particular: first, data safety by avoiding both manual interaction during critical laboratory steps (i.e. when DNA is transferred form one tube into another), and errors due to manual transcription of sample information and results. Secondly, efficient sample processing by automizing the laboratory procedure with the help of robotic instruments, thus, giving the DNA staff more time to analyze data.

Austria↗
PubMed2001

Spontaneous remission in a secondary acute myelogenous leukaemia following invasive pulmonary aspergillosis.

Spontaneous remission of adult acute myelogenous leukaemia (AML) represents a rare event. We report a 60-year-old female patient suffering from secondary AML M1 and severe invasive pulmonary hyalohyphomycosis highly suggestive of aspergillosis. Two months after the diagnosis of leukaemia, she achieved a spontaneous remission lasting 3 months, although neither cytostatic drugs nor corticoids were administered because of a septic condition. At the time of remission, a chronic hepatitis C virus infection and a polyclonal hypergammaglobulinaemia were present, and the patient received granulocyte colony-stimulating factor once. This report represents the first documentation of a spontaneous remission in AML following invasive pulmonary hyalohyphomycosis. Possible mechanisms of this phenomenon are discussed.

Aspergillosis↗
PubMed2001

Population genetics of ten STR loci (AmpFlSTR SGM plus) in Austria.

A population study on the ten short tandem repeat (STR) loci D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01 and FGA was performed on 204 unrelated Austrian Caucasians. The DNA was amplified by multiplex PCR using the AmpF/STR SGM plus kit. All loci met Hardy-Weinberg expectations. The combined power of exclusion for the ten STR loci was 0.999976. The results show that these loci are very useful for forensic purposes.

Austria↗
PubMed2001

Automation and high through-put for a DNA database laboratory: development of a laboratory information management system.

Automation and high through-put production of DNA profiles has become a necessity in every DNA database unit. In our laboratory we developed a Laboratory Information Management System (LIMS) controlled workflow architecture, which comprises a robotic DNA extraction- and pipetting-system and a capillary electrophoresis unit. This allows a through-put of 4,000 samples per person per year. Improved sample handling and data management, full sample- and batch-histories, and software-aided supervision of result data, with a consequent average turn-around time of 8 days, are the main features of our new system.

Austria↗
PubMed2001

When autosomal short tandem repeats fail: optimized primer and reaction design for Y-chromosome short tandem repeat analysis in forensic casework.

Y-chromosomal short tandem repeats (Y-STRs) are useful forensic DNA markers in investigation of sexual assault cases when a mixture of male and female DNA (e.g., in vaginal swabs) is present in a sample, especially when DNA of the male contributor is present only in very small amount compared to the DNA of the female victim. With autosomal STR analysis of male and female DNA, male DNA in mixtures can usually be detected and correctly interpreted only when it exceeds 5%. However, the amplification of some Y-STRs is known to result in polymerase chain reaction (PCR) products that are not associated with the Y-chromosome, but derive from the X-chromosome and/or autosomal regions. This can cause problems in the interpretation of results, particularly when female DNA is present in excess. Consequently, more specific and sensitive Y-STR primers and PCR conditions are needed. This paper presents two casework examples in which sensitive Y-STR multiplexes (with the addition of PCR enhancer) were successfully used in the analysis of mixtures of male and female DNA, the male component not interpretable by standard autosomal STR typing.

Adolescent↗
PubMed2000

Species identification by means of the cytochrome b gene.

Species identification was carried out by nucleotide sequence analysis of the cytochrome b (cytb) gene. The aim of the study was to identify biological specimens from diverse vertebrate animals by extracting and amplifying DNA from 44 different animal species covering the 5 major vertebrate groups (i.e. mammals, birds, reptiles, amphibians and fishes). The sequences derived were used to identify the biological origin of the samples by aligning to cytb gene sequence entries in nucleotide databases using the program BLAST. All sequences were submitted to the GenBank including new species which were not observed in the databases. The applicability of this method to the forensic field is demonstrated by simulated casework conditions where different types of samples including problematic specimens such as hair, bone samples, bristles and feathers were investigated to identify the species.

Animals↗
PubMed2000

Age dependent apoptosis and loss of rhabdosphincter cells.

PURPOSE: To our knowledge the exact age dependent morphological and functional changes of the sphincter mechanism have not been investigated. Therefore, cell densities of the urethra and the urethral rhabdosphincter across various age groups, and the appearance of apoptosis were examined to explore the changes in these structures during the aging process. MATERIALS AND METHODS: Specimens were obtained from 16 male and 7 female cadavers 5 weeks to 92 years old. Histological sections were taken from 3 different levels of the rhabdosphincter and urethra. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling method was used to detect apoptosis in the urethra and rhabdosphincter. In all specimens relative volume densities of the striated muscle fibers, apoptotic indexes and diameters of the rhabdosphincter and urethra were determined. RESULTS: An age dependent increase of apoptosis of the striated muscle fibers of the rhabdosphincter led to a dramatic decrease in the number of striated muscle cells. In the 5-week-old neonate 87.6% and in the 91-year-old woman 34.2% of the rhabdosphincter consisted of striated muscle cells. Overall, a direct linear correlation between the age of the specimens and decrease in volume densities of the striated muscle cells was evident. CONCLUSIONS: The dramatic decrease in the number of striated muscle cells in the rhabdosphincter of the elderly due to apoptosis represents the morphological basis for the high incidence of stress incontinence in this population.

Adolescent↗
PubMed1999

Quantitative determination of joint incongruity and pressure distribution during simulated gait and cartilage thickness in the human hip joint.

The objective of this study was to provide quantitative data on hip-joint incongruity and pressure during a simulated walking cycle and on articular-cartilage thickness in the same set of specimens. Using a casting technique in eight specimens of the human hip (age: 18-75 years), we determined the width of the joint space (incongruity) required at minimal load for contact at four phases of the gait cycle. The pressure distribution, measured with pressure-sensitive film, was determined at physiologic load magnitudes on the basis of in vivo measurements of hip-joint forces. Cartilage thickness was assessed with A-mode ultrasound. At minimal loading, the average maximum width of the joint space ranged from 1.1 to 1.5 mm in the acetabular roof, with the contact areas located ventro-superiorly and dorso-inferiorly throughout the gait cycle. At physiological loading, the width decreased and the contact areas covered the complete articular surface during midstance and heel-off but not during heel-strike or toe-off. The pressure distribution was inhomogeneous during all phases, with average maximum pressures of 7.7 +/- 1.95 MPa at midstance. The cartilage thickness varied considerably throughout the joint surfaces; maxima greater than 3 mm were found ventro-superiorly. These data can be used to generate and validate computer models to determine the load-sharing between the interstitial fluid and the solid proteoglycan-collagen matrix of articular cartilage, the latter being relevant for the initiation of mechanically induced cartilage degeneration.

Adolescent↗
PubMed1999

[Quantitative determination of pressure distribution in the hip joint during the gait cycle].

The objective of this investigation was the experimental determination of the contact pressures in the hip joint for characteristic phases of the gait cycle. The joint forces determined in vivo with telemetric endoprosthesis by Bergmann et al. (1993) were converted into a pelvic reference system, based on kinematic gait analysis. In eight cadaveric hip joints (age 18-75 yrs.) the reaction forces were applied corresponding to four phases of the gait cycle (heel strike, mid-stance, heel off, toe off) and the pressure distribution determined with FUJI pressure sensitive film. We found maxima of 10 MPa during mid stance. The areas of highest pressure were located in the ventro-superior aspect of the acetabulum (anterior part of the acetabular roof) and in the dorso-inferior aspect of the lunate surface. The pressure distribution was relatively constant during the four phases and the maxima did not vary proportional to the applied load. The normal pressure distribution in the hip appears to be determined by the physiological incongruity of the articular surfaces and the inhomogeneous bony support of the acetabulum. During operative interventions this normal load transfer should be restored as accurately as possible.

Adolescent↗
PubMed1999

Determination of calcaneal ultrasound properties ex situ: reproducibility, effects of storage, formalin fixation, maceration, and changes in anatomic measurement site.

The objective of this study was to determine the reproducibility of ultrasonic bone properties with a system for measuring calcanei ex situ; the influence of changes of the measurement site; and the effects of fixation, storage, and maceration. We examined 14 fixed calcanei and 12 fresh bones. Ultrasonic measurements were performed ex situ after degassing, using an Achilles+ system and a special positioning device. The instrument precision was 0.16% for speed of sound (SOS), 1.4% for broadband ultrasonic attenuation (BUA), and 1. 8% for the stiffness index (SI). The short-term precision was 0.54%, 1.9%, and 2.8%, respectively. A defined shift of the measurement site (5 mm distal of the middle) led to unpredictable changes in ultrasound (US) properties (r = 0.65 for SOS, 0.82 for BUA, and 0.75 for SI). Embalment with 4% formalin/96% alcohol caused a systematic decrease in SOS, an increase in BUA, and a decrease in SI (mean = -12.7 units; P < 0.001), the effect increasing with time. However, values at 6 months of fixation and later were highly correlated with those in fresh specimens (r = 0.95 for the SI). Two weeks storage in degassed and normal solution had only modest effects on ultrasound properties. Maceration did not lead to a systematic increase or decrease of ultrasound variables, but introduced unpredictable changes (r = 0.64-0.94). We conclude that in comparative biomechanical studies it is feasible to measure calcaneal specimens embalmed in formalin/alcohol ex situ, if the primary interest is not in the absolute values but in the correlation with mechanical failure loads at other skeletal sites.

Aged↗
PubMed1999

In situ measurement of articular cartilage deformation in intact femoropatellar joints under static loading.

The deformational behavior of articular cartilage has been investigated in confined and unconfined compression experiments and indentation tests, but to date there exist no reliable data on the in situ deformation of the cartilage during static loading. The objective of the current study was to perform a systematic study into cartilage compression of intact human femoro-patellar joints under short- and long-term static loading with MR imaging. A non-metallic pneumatic pressure device was used to apply loads of 150% body weight to six joints within the extremity coil of an MRI scanner. The cartilage was delineated during the compression experiment with previously validated 2D and 3D fat-suppressed gradient echo sequences. We observed a mean (maximal) in situ deformation of 44% (57%) in patellar cartilage after 32 h of loading (mean contact pressure 3.6 MPa), the femoral cartilage showing a smaller amount of deformation than the patella. However, only around 7% of the final deformation (3% absolute deformation) occurred during the first minute of loading. A 43% fluid loss from the interstitial patellar matrix was recorded, the initial fluid flux being 0.217 +/- 0.083 microm/s, and a high inter-individual variability of the deformational behavior (coefficients of variation 11-38%). In conjunction with finite-element analyses, these data may be used to compute the load partitioning between the solid matrix and fluid phase, and to elucidate the etiologic factors relevant in mechanically induced osteoarthritis. They can also provide direct estimates of the mechanical strain to be encountered by cartilage transplants.

Adolescent↗
PubMed1999

Measurement of vertebral rotation: a comparison of two methods based on CT scans.

This study compared Ho's and Aaro's method to measure vertebral axial rotation in order to find the more accurate one. Two hundred fifty-nine CT scans were taken from 11 cadaver vertebrae. The scans were performed with vertebrae in neutral position and angulated up to 20 degrees in the sagittal and frontal plane to simulate kyphosis/lordosis and side bending. Axial rotation was measured according to both methods. The mean difference between true and measured values was 3.7 +/- 6.7 (95% confidence limit) (Ho's method) and 2.3 +/- 3.7 (Aaro's method), respectively. Correlation with true axial rotation was r2 = 0.66 (Ho's method) and r2 = 0.77 (Aaro's method). We recommend using Aaro's method as the more accurate measure of axial rotation in scoliotic vertebrae.

Cadaver↗