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Biomedical subjects

G Salamon

Publications and source records attributed to G Salamon.

At least 73 records · Page 4Linked to original sources
PubMed1983

[Progressive multifocal leukoencephalopathy. Clinical, CT scan and neuropathologic findings. Apropos of 4 cases].

Four cases of progressive multifocal leukoencephalopaty are reported, 3 of them with an ultrastructural study and 2 with a C.T. scan study. In 2 cases, there were no other associated pathological condition. In 1 case chronic alcoholism only was present; in the last case a primitive hemochromatosis with a prevailing hepatic dysfunction was evidenced. In 2 of these cases, the initial clinical picture was made of mental disorders while it was made of a progressive left hemiparesis in one case and of a brain stem syndrome in the other case. The results of neuroradiological and isotopical investigations remained negative throughout the evolution in the 4 cases except for some C.T. scan abnormalities. Indeed, in 2 cases the C.T. scan evidenced brain lesions identified as large demyelinated areas. These were low density areas non altered by contrast and unaccompanied by any mass effect. These areas were not seen when the first clinical signs were present and thus, normality of C.T. scan appears not to allow infirmation of the diagnosis of progressive multifocal leukoencephalopathy. In the 4 cases the pathological study showed characteristic lesions of the white matter. Mononucleated cells inflammatory infiltration was observed at the periphery of the demyelinizated regions. This may be related with the primitive aspect of these cases. An ultrastructural study was performed in 3 cases: viral inclusions were present not only in the nucleus of oligodendrocytes but also in their cytoplasm and in some astrocytes.

Adult↗
PubMed1982

Normal CT anatomy of the spine. Anatomo-radiological correlations.

To analyse the anatomo-radiological correlation of the spine and spinal cord, 22 formalized, frozen anatomical specimens corresponding to different regions of the spinal column (8 cervical, 5 dorsal, and 9 lumbar) were studied by CT scans on axial, sagittal and coronal planes and by contact radiography after they were cut into anatomical slices in order to clarify the normal CT anatomy of the spinal column. The results obtained from CT patient scans, performed exclusively on the axial plane, were compared with those obtained from the anatomical specimens (both CT and contrast radiography). High resolution CT programs were used, enabling us to obtain better individualization of the normal structures contained in the spinal column. Direct sagittal and coronal sections were performed on the specimens in order to get further anatomo-radiological information. Enhanced CT studies of the specimens were also available because of the air already present in the subarachnoid spaces. Excellent visualization was obtained of bone structures, soft tissue and the spinal cord. High CT resolution of the spine appears to be an excellent neuroradiological procedure to study the spine and spinal cord. A metrizamide CT scan is, however, necessary when a normal unenhanced CT scan is insufficient for diagnosis and when the spinal cord is not clearly visible, as often happens at the cervical level. Clinical findings are certainly very useful to ascertain the exact CT level and to limit the radiation exposure.

Cervical Vertebrae↗
PubMed1981

Local cerebral glucose utilization in the newborn brain.

Local cerebral glucose utilization (LCGU) was determined in 2- to 8-day-old beagle dogs by the quantitative 14C-deoxyglucose autoradiographic method. In physiologically controlled puppies (BP 66 +/- 3 mm Hg; paO2 71 +/- 2 mm Hg; paCO2 35 mm Hg, pH 7.39 +/- 0.04; hematocrit 39 +/- 2%), the 2-deoxyglucose (2-DG) autoradiographs and quantitative data reveal a characteristic pattern of regional energy metabolic needs in the normal newborn brain: highest glucose consumption values are found in brain stem nuclei (inferior olivary nucleus 19 +/- 4 mumol/100 g/min; vestibular nucleus 26 +/- 5; red nucleus 15 +/- 2) and in selected deep cerebral structures (subthalamic nucleus 18 +/- 4; ventrolateral thalamic nucleus 12 +/- 2, ...) whereas consistently relative lower glucose consumption is found in the cerebral cortex (mean 7 +/- 1). This data is in agreement with local cerebral blood flow studies in the newborn puppy. A characteristic functional anatomy of the newborn dog brain is demonstrated. The value of 0.558 +/- 0.031 for the lumped constant was used in the calculation of LCGU. In puppies previously asphyxiated for 2.5-3.5 min 1-2 days prior to the 2-DG procedure, no significant effect upon regional metabolism was demonstrated.

Animals↗
PubMed1980

Nuclear scattering radiography.

The quasi-elastic scattering of 1 GeV protons permits the three-dimensional reconstruction of the density distribution in extended bodies. Fast multiwire proportional chambers are used to localize the position of every incoming and outgoing charged particle and to determine the coordinates at the interaction vertex. This article describes tests on a human head fixed on formalin. The comparison with computed tomography scans and anatomical sections is encouraging. Slices with a volume element of 5.5 mm3 illustrate the sensitivity of the method. The results also demonstrate the ability of the method to select the density distribution of hydrogen by making use of the kinematic relations specific to elastic scattering. Trials of this method in living humans are being planned.

Brain↗
PubMed1979

Correlative study between computerized transverse scanning and stereoimpedoencephalography in space-occupying lesions of the brain.

Stereoimpedoencephalography (SIEG) is routinely used by the authors during stereotactic investigations of glial brain tumours prior to stereotactic implantation of isotopes or prior to conventional surgery: the brain tissue impedance is measured along a probe track according to the four electrodes impedance technique. The correlation between the tissue structures and the corresponding impedance values has been studied by comparison with the CATScan data reported on the stereotactic schedules; impedance values are influenced by changes in arterial pCO2 and also by other unknown factors; in order to avoid these uninterpretable changes of the impedance, the recorded values have been normalized with respect to the average impedance along a control track in the normal hemisphere. As a rule, the impedance profile exhibits a "hole" at the site of the pathological processes like tumours as well as surrounding oedema, and the delimitation of the pathological area is very similar to that obtained by the CATScan. There is a good linear correlation between the values of normalized impedance and the x-ray absorption as given by the computer listing of the CATScan. Lastly, statistical values of normalized impedances are determined for the main structures of the brain, showing that the tumour tissue has an impedance equal to half the impedance of the normal tissue.

Brain Neoplasms↗
PubMed1978

Investigations of nontumoral hydrocephalus in children.

An analysis was made of 175 cases of pediatric nontumoral hydrocephalus. CT scan by itself permits a precise diagnosis in only one-third of the cases. However, when the clinical context suggests that hydrocephalus is secondary to certain conditions such as infection, bleeding, or trauma, CT scan may suffice, unless more advanced investigation permits more efficient treatment. When hydrocephalus is associated with brain malformations, however, more complete investigation is needed for a better understanding of the condition. Conventional contrast studies are quite safe, especially ventriculography which is easy to perform in this type of patient, who is usually investigated during the first 12 months of life.

Age Factors↗