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Biomedical subjects

A Resch

Publications and source records attributed to A Resch.

26 records · Page 2Linked to original sources

Comparison of imaging accuracy at different MRI units based on phantom measurements.

In this investigation standardized on-site phantom measurements at 27 MRI units were carried out. A scoring system was developed for rating both symmetry and distortion of the image. This study shows, with regard to the clinical use of MRI-assisted treatment planning in radiotherapy, that in more than 85% of all planes (transversal, sagittal, coronal) the MRI units were equivalent to the standard known from literature.

Artifacts↗

Ternary complex formation on leaderless phage mRNA.

The phage Lambda PRM promoter-derived cI mRNA and phage P2 gene V mRNA are transcribed beginning with the A residue of the AUG start codon. Using lacZ fusion analysis we have assessed the effects of alterations in the immediate downstream coding region on the translational efficiency of these mRNAs. Mutations, including deletions of the putative downstream box of either cI or gene V mRNAs, showed no significant reduction in expression of the different lacZ fusions. Primer extension inhibition analysis suggests a role of ribosomal protein S1 in cI mRNA recognition.

Bacteriophage lambda↗

Risk of vertebral fractures in men: relationship to mineral density of the vertebral body.

OBJECTIVE: Vertebral fracture is the most frequent manifestation of osteoporosis in women. Because there is a lack of information about bone density and the occurrence of fractures in men with osteoporosis, we evaluated the relationship between vertebral fractures and spinal bone mineral density (BMD) to determine if there is a threshold of BMD below which fractures are likely to occur. SUBJECTS AND METHODS: Radiographs of the spine and BMD measurements of the lumbar spine as measured by quantitative CT were obtained in 201 men 21-86 years old (mean age, 68 +/- 4 years) who were referred consecutively for osteoporosis screening. Radiographs were interpreted for the presence or absence of vertebral fractures. The probability of fractures was determined after classifying the patients into subgroups according to their quantitative CT values. The relationship of spinal bone mass to spinal fracture was examined by both logistic regression and receiver operating characteristic (ROC) analysis. RESULTS: Seventy-one patients were classified as having definite vertebral compression fractures. Spinal BMD was 132 +/- 34 mg/ml for the 130 men without vertebral fractures and 75 +/- 22 mg/ml for the 71 men with vertebral fractures (p < .001). The number of fractures per patient and the BMD were negatively correlated (r = -0.71, p < 0.0001). When a BMD of 100 mg/ml was given as a fracture threshold, 15% of the patients without fractures were below this value and 14% of the patients with fractures were above this threshold. Quantifying the overlap between values from patients with and without fractures by ROC analysis, the value of 100 mg/ml gave a sensitivity of 86%. Logistic regression showed 105 mg/ml as the most discriminate value, resulting in a sensitivity of 90%. Logistic regression analysis of the predicted fracture probability also indicated that age does not significantly influence the regression curve. CONCLUSION: We found that direct quantitative CT measurement of the BMD of the vertebral body is a highly efficient approach to distinguish men without vertebral fractures from those with fractures. Thus, a fracture-threshold concept could provide a quantitative criterion to identify men at high risk for vertebral fractures.

Adult↗

[Evidence of fluoride-induced effects on the calcaneus by measurements of broadband ultrasound attenuation (BUA)].

We measured broadband ultrasound attenuation (BUA) of the calcaneus as well as radial (RBD) and spinal bone density (SBD) in normal and osteoporotic females (n = 188) both before treatment and after long-term fluoride therapy. RBD was measured using single photon absorptiometry of the non-dominant distal forearm (SPA) and spinal bone density (SBD) was assessed using quantitative CT (QCT). In untreated osteoporotic patients (n = 62), BUA as well as the other densitometric methods showed significantly lower values (p < 0.05) when compared to age matched controls (n = 75). Females with osteoporosis and long-term treatment with fluoride (n = 51) had both significantly higher BUA values and higher spinal bone density when compared to women with untreated osteoporosis. BUA and SBD were correlated in the entire group (r = 0.5, r < 0.0001) as well as in the subgroups of untreated (r = 0.48, p < 0.001) and fluoride-treated patients with osteoporosis (r = 0.4, p < 0.05). These results suggest that BUA provides further evidence of an osteogenic response to fluoride at peripheral weight-bearing skeletal sites such as the calcaneus.

Absorptiometry, Photon↗

[Myiasis in female travelers to the tropics].

Myiasis is a rare disease in Europe and the USA; it is defined by the development of parasitic, mostly tropical maggots in the human body. They are best identified by the pattern of their terminal spiracles and the shape of their stigmal plates. In spite of the size of the larvae of Cordylobia anthropophaga, there is only low-grade inflammation; the clinical course is benign.

Aged↗

Silastic cup vacuum extractor or forceps: a comparative study.

A retrospective analysis over a 2-year period was carried out to compare the limitations in the use of the Silastic Cup vacuum extractor and forceps as the preferred instrument for operative vaginal delivery. Whilst the use of the vacuum extractor was associated with less maternal morbidity (54.9% episiotomy rate; 20.9% nil analgesia) and comparable neonatal problems, an increased failure rate (6.5%) was demonstrated in comparison to forceps delivery (0.7% failed vaginal delivery rate). A comparison of their use for rotational vaginal delivery failed to reveal any significant difference in maternal or neonatal outcome apart from an increased failure rate (30%) to complete vaginal delivery after application of the vacuum extractor. It is concluded that the vacuum extractor is a comparable instrument for midcavity or lift-out instrumental delivery but Kielland's forceps may still be a more appropriate instrument for rotational vaginal delivery.

Delivery, Obstetric↗