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Biomedical subjects

J Jeske

Publications and source records attributed to J Jeske.

At least 37 records · Page 2Linked to original sources
PubMed1990

Positron emission tomography of fluorine-18-deoxyglucose and image-guided phosphorus-31 magnetic resonance spectroscopy in brain tumors.

Positron emission tomography (PET) of 2(18F)-fluoro-2-deoxy-D-glucose (FDG) and volume-selective phosphorus-31 magnetic resonance spectroscopy (31P-MRS) are methods used to assess the energy metabolism of the brain. Both methods were studied with respect to their contribution to differential diagnosis in 23 patients with various brain tumors. The various neuroectodermal tumors differed with respect to their metabolic rate for glucose (MRGL). Benign and malignant tumors could be better differentiated by using tumor metabolism relative to contralateral brain and by evaluating heterogeneities in tumors. Low-grade gliomas usually showed normal 31P-MR spectra; high-grade gliomas were characterized by reduced and often split phosphodiester peaks and alkaline pH. Meningiomas, which had variable MRGL, typically showed extremely low phosphocreatine levels, reduced phosphodiesters, and alkaline pH. We concluded that FDG-PET and 31P-MRS examine different aspects of tumor metabolism. Therefore, both can contribute independently and complementarily to the differential diagnosis of brain tumors.

Astrocytoma↗
PubMed1989

[Metabolic studies of gliomas with positron emission tomography and phosphorus 31 MR spectroscopy in diagnosis and treatment planning].

Glioma are often histologically heterogenous. As many of these tumors are not removable in toto, due to their localisation, the most malignant part of the tumor may be missed and information for optimum therapeutic management is incomplete. Furthermore, low grade gliomas tend to become more malignant in their development; additional surgical intervention is often not possible. Non-invasive measurement of tumor glucose metabolism with (F-18)-2-fluoro-2-deoxyglucose (FDG) and positron-emission-tomography (PET) may be used to evaluate tumor malignancy. Malignant gliomas (astrocytoma III degree and glioblastoma) frequently showed increased peak metabolic rates (in comparison with normal white matter) and uncoupling of FDG transport and phosphorylation. Preliminary experiences with image-guided localized phosphorus-31 MR spectroscopy (P-31 MRS) demonstrated a decrease of phosphodiesters in malignant gliomas, whereas the phosphomonoesters showed an increase in several cases. The phosphocreatine peak was often reduced. A more active therapy of low grade gliomas might be indicated when signs of hypermetabolism in FDG-PET and alteration of energy-rich phosphates or membrane-phosphates in P-31 MRS are found.

Adenosine Triphosphate↗
PubMed1981

Ultrastructural modifications of the erythrocyte membrane in Down's syndrome.

Spin label studies of erythrocyte membranes from patients with Down's syndrome showed no differences in the rigidity of membrane lipids with respect to normal subjects and a tendency for alterations in the state of membrane proteins. Electron microscopic studies demonstrated the occurrence of ultrastructural defects in membranes from trisomics which can be due to accelerated red cell aging as similar alterations were found in the fraction of oldest (most dense) cells in normal subjects.

Adolescent↗
PubMed1980

Superoxide dismutase and radiation-induced haemolysis: no benefit of its increased content in red cells.

The sensitivity of human erythrocytes with normal and increased activity of superoxide dismutase (SOD) was compared under different types of oxidative stress. Red blood cells with increased SOD activity were more resistant to haemolysis induced by photoactivated riboflavin but no more resistant to radiation-induced haemolysis and acetylphenylhydrazine stress. These results indicate a negligible role of O(2) in mediation of the haemolytic action of ionizing radiation.

Cobalt Radioisotopes↗
PubMed1978

Down syndrome - transferrin parallels plasma iron changes.

The transferrin level was studied in patients with simple trisomy 21 and with Robertsonian unbalanced translocations 21/22 and 21/14. In all these groups of patients, known to have significantly lowered plasma iron levels, the transferrin levels were found to be decreased with respect to the control group.

Adolescent↗