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Biomedical subjects

E Schultz

Publications and source records attributed to E Schultz.

At least 109 records · Page 6Linked to original sources
PubMed1986

A cytogenetic study of familial medullary carcinoma of the thyroid.

Familial medullary carcinoma of the thyroid (MCT) is a malignant neoplasm of the calcitonin-producing C-cells of the thyroid gland, inherited in an autosomal dominant pattern with a high degree of penetrance. We have studied 26 individuals from 5 New England families with MCT with the goal of finding a cytogenetic test useful in the detection of the presence of the gene. G-banded metaphase spreads, segregational errors of chromosomes, breakage in untreated cells, breakage in bleomycin-challenged cells, and high-resolution banding of prophase/prometaphase spreads were examined; one or more of each of these procedures were studied in at least one affected individual in each of 5 families. All specimens were coded, and slides were scored blindly. All tests were negative with respect to significant differences from controls. We did not observe the minute deletion from the short arm of chromosome 20 that was reported by other investigators to occur in individuals with multiple endocrine neoplasia types 2A and 2B which include MCT. Contrasting results from our study and several other cytogenetic studies of MCT may reflect genetic heterogeneity among the families studied and/or differing environmental factors in various geographic locations that are possibly associated with initiation and onset of the disease.

Bleomycin↗
PubMed1986

[Phantom substances for the quantitative evaluation of MR T images. I. Paramagnetic agar gels for the optimal simulation of tissue specific MR T parameters].

Reference material for quantitative magnetic resonance imaging (MRI) has been developed by combining water, gelling agent agar, and paramagnetic ions (Gd3+). By in-vitro measurement of the relaxation times T1 and T2 it can be shown that tissue-relevant values can be attained. The substances described are physically and chemically stable and can be handled without problems.

Agar↗
PubMed1986

Phantom material for quantitative evaluation of MR images.

Reference material for quantitative Magnetic Resonance Imaging (MRI) has been developed by combining heavy and light water (D2O, H2O), gelling agent agar, and paramagnetic transition metal ions (Gd3+). The process of preparation is described. By in vitro measurement of relaxation times, T1 and T2, it can be shown that tissue relevant values are achievable. The influence of different relaxation times, as well as the effect of different proton spin densities, on MRI signal intensities is determined. Some similarities existing between the magnetic resonance behaviour of tissue water and phantom substance water are discussed.

Agar↗
PubMed1986

[Phantom substances in the quantitative evaluation of magnetic resonance T-images. II. Effect of relaxation times on magnetic resonance T-intensity values].

Reference material for quantitative MR Imaging (paramagnetic agar gel) is examined with regard to effects of small T1 and T2 variations on MRI signals. For some pulse sequences that are important in clinical practice, it can be shown that SE images are very sensitive to T2 variations, whereas IR images are influenced by both T1 and T2.

Electron Spin Resonance Spectroscopy↗
PubMed1985

Effects of skeletal muscle regeneration on the proliferation potential of satellite cells.

Skeletal muscle satellite cells are myogenic stem cells that function to repair damaged muscle fibers. Participation of satellite cells in a regeneration response following muscle injury results in a significant reduction in their cumulative proliferation potential. The magnitude of the reduction is proportional to the number of regeneration responses in which the cells participate.

Animals↗
PubMed1985

[A simple method for imaging disorders of cardiac wall contraction using MRT].

By means of ECG triggering, it is possible to demonstrate various phases of cardiac action. It is then possible to derive a measure for cardiac function. The disadvantage of the method consists of the long measurement period required and the creation of movement artifacts. A method is discussed which would permit the demonstration of normal cardiac movement during a short time span and which reduces artifacts. In order to obtain optimum results, a new sequence of measurements is suggested. This is based on spin-echo sequences and can readily be used with any type of MRT apparatus.

Adult↗
PubMed1985

[The effect of periodic object movements on MRT image quality].

Object movement influences the images in MRT, producing phantom images and blurred contours, while also affecting the intensity of the signal. Phantom images and blurring of contours can be largely prevented by suitable signal triggering in case of rhythmic movements caused, for example, by cardiac pulsation or respiration. However, the intensity of the signal follows a different pattern. Periodic movement in the image plane (sagittal plane) has no effect on signal intensity if the exposures are triggered. Object movement across the image plane causes changes in signal intensity, even with triggered exposures.

Heart↗
PubMed1985

Effects of chronic exercise during aging on muscle and end-plate morphology in rats.

Terminal sprouting, myofiber atrophy, and fiber type changes were studied in soleus and distal gastrocnemius muscles of 21- and 26-mo-old rats and in rats who performed treadmill running from 21 to 26 mo. End-plate structure and muscle fiber types were demonstrated by staining for acetylcholinesterase and myosin ATPase activity. Terminal sprouting was expressed as the percentage of end plates with growth configurations. Fiber atrophy was assessed as percentage of small-diameter fibers. In all three groups, the percentage of small-diameter fibers was significantly smaller and the percentage of growth configurations significantly larger in the soleus than in the gastrocnemius. The exercised-soleus group had a significantly higher percentage of growth configurations than the 26-mo controls, which had a higher percentage than the 21-mo controls. Percentages among gastrocnemius groups were not different. Fiber type was similar among gastrocnemius groups. However, the exercised-soleus had significantly more slow-twitch fibers than the controls. These data suggest that the soleus responds differently to chronic exercise during aging than does the gastrocnemius.

Aging↗
PubMed1985

Fat as a factor affecting resolution in diagnostic ultrasound: possibilities for improving picture quality.

Fat and air are the main factors affecting quality by causing interference in ultrasound. Deterioration in resolution with increasing thickness of overlapping fat has been verified experimentally. The following factors have provided better resolution in experimental studies: large aperture transducers; compound technique (good axial resolution compensates for poor lateral resolution); compression of fat and location of the fat in the focus of the transducer; large beam width of the ultrasound signal. In a clinical study with 663 patients the influence of compression and compound technique on visualisation of abdominal structures was tested with a Combison 100 real-time scanner, Combison 202 compound scanner and the Octoson system. The retroperitoneal space was not demonstrated in 66 patients. Compression with the real-time transducer improved demonstration in 50% of studies (33/66), as compared to 20% (19/66) with the compound technique. Resolution was affected by velocity errors and reflection in 30% of cases (19/66) examined with the compound technique.

Adipose Tissue↗
PubMed1985

[Physical and technical bases for the use of magnetic resonance in radiological diagnosis].

This article describes the most important fundamentals of the application of MR to radiologic diagnostics--especially with regard to the tomographic measurements (MR-T) that, at present, provide many different and interesting clinical results. The properties of MR-sensitive nuclei are discussed together with their behavior in magnetic fields under the influence of radiofrequency energy. Technical problems such as slice definition, encoding and decoding of spatial information within the slice by the application of gradient fields, are also presented. This is then followed by some aspects of spectroscopic measurements (MR-S), including chemical shift and intensity relations within the spectra. Finally the most important characteristics of the different tomographic and spectroscopic apparatus are described.

Humans↗