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Biomedical subjects

M Kormano

Publications and source records attributed to M Kormano.

At least 91 records · Page 5Linked to original sources

Otoneurological and ultra low field MRI findings in multiple sclerosis patients.

Otoneurological and ultra low field MRI findings in multiple sclerosis patients: 22 patients suffering from multiple sclerosis (MS) underwent thorough neurological and otological examination, extensive ENG testing and Magnetic Resonance Imaging (MRI) examination of the central nervous system. All patients fulfilled the Schumacher criteria for a diagnosis of definitive MS. 20 of the patients had been included in previous otoneurological studies three to five years ago. The general disability assessed according to Hyllested's scale was: Class 1-7, Class 2-4, Class 3-6, Class 4-3, Class 5-2 patients. Thus 11 patients had none or only slight disability. Nevertheless, all patients showed abnormal findings when classified according to the Kurtzke disability scale, which reflects the involvement of separate neuronal entities. The ENG examination revealed abnormal findings in all patients. The most common abnormalities found were as follows: abnormal pendular test 19, ocular fixation index 18, optokinetic nystagmus 14, saccadic eye movements 14 and spontaneous nystagmus 12. 14 patients had uni- or bilateral abnormally slow adduction movements in the saccadic test consistent with internuclear ophthalmoplegia (INO), which is caused by a lesion of the brain stem. MRI examination of the 21 patients studied revealed abnormal findings consistent with MS in sixteen cases. The lesions were unilateral in 5 and bilateral in 11 patients. The most common location for these abnormal findings consistent with MS plaques were in the white matter around the lateral ventricles. Plaques in the brain stem and/or cerebellum were found in only two cases despite numerous clinical and otoneurological findings that indicated the presence of functional lesions in these areas.

Adult↗

Induction of mitotic micronuclei by X-ray contrast media in human peripheral lymphocytes.

In vitro and in vivo cytogenetic effects of X-ray contrast media (CM) were determined by scoring micronuclei (MN) in 72-h cultures of human peripheral lymphocytes. Both ionic (sodium meglumine diatrizoate, methylglucamine diatrizoate, and sodium meglumine ioxaglate and nonionic CM (iosimide, iopromide, iohexol and iotrolan) were able to induce MN in lymphocytes. Based upon their calculated percent probabilities for MN induction, these agents could be ranked in their decreasing order of probability, as iosimide greater than sodium meglumine ioxaglate greater than iohexol greater than sodium meglumine diatrizoate greater than iopromide greater than methylglucamine diatrizoate greater than iotrolan. Stepwise logistic regression analysis of the data indicated that the frequency of MN in CM-exposed lymphocyte cultures was significantly higher than the frequency of MN in control cultures (P less than 0.001). In clinical studies where 14 patients were injected with an ionic CM methylglucamine diatrizoate, lymphocyte cultures from 10 patients showed higher frequencies of MN. The differences between pre- and post-CM counts of MN were significant in a Mann-Whitney U test (P less than 0.05). The effect of X-irradiation on MN formation in lymphocytes was separately determined and was found to be insignificant. These results indicate that irrespective of ionic and osmolality differences, X-ray contrast agents are capable of producing chromosomal damage in peripheral lymphocytes. Further studies are required to establish molecular mechanisms in the observed cytogenetic effects of CM in cell cultures.

Age Factors↗

Uptake and dissolution of particulate iodipamide ethyl ester in the spleen. A morphologic study.

Iodipamide ethyl ester (IDE) is an experimental particulate contrast agent being developed for CT image enhancement of the liver and spleen. IDE particles are phagocytized by the reticuloendothelial cells after an intravenous injection. The uptake and dissolution of IDE particles were studied in the spleen with light and electron microscopy. Two minutes after injection, intra- and extracellular IDE particles were found in the red pulp of the spleen. Highest concentration of IDE was seen in the marginal zone surrounding the white pulp. Particles also were seen elsewhere in the red pulp but only occasionally between the outermost cells of the white pulp. The extracellular particles disappeared within 4 hours postinjection. At one day postinjection, the amount of intracellular IDE particles had begun to decrease. Electron micrographs showed that the intracellular particles dissolved gradually in the phagocytes and caused transient degenerative morphologic changes. At three days postinjection, practically all IDE particles had disappeared from the spleen. Polystyrene latex particles were used as controls. They were phagocytized like the IDE particles, but they did not disappear from the phagocytes. IDE particles caused no morphologic injuries in nonphagocytic cells of the spleen.

Animals↗

Proton relaxation times in arterial wall and atheromatous lesions in man.

The proton relaxation times of autopsy samples of arterial intima-media were measured with an NMR spectrometer and results correlated to the microscopically estimated lipid content of the vascular wall. The normal arterial intima-media contained two T1 relaxation components. The short T1 component (T1s) was 90 +/- 13 ms and its relative weight was 11%. The long T1 component (T1l) was 523 +/- 89 ms and relative weight 88%, respectively. The average T2 was 99 +/- 18 ms. In diseased vessels, a positive correlation was found between the lipid content of the vessel wall and the relaxation rate of the fast component. T1s of the intima-media was significantly shorter (P less than .01) in severe atheromatosis compared with vessels without fat deposition. The results suggest that atheromatous lesions should be best highlighted in spin-echo images by using short TR and TE to suppress the influence of T1l and to avoid (noncontrast contributing) T2 decay of the signal intensity.

Adolescent↗

Response of white blood cells to iodipamide ethyl ester particles.

The effect of intravenously injected iodipamide ethyl ester (IDE) particles (150 mgl/kg) on white blood cells was studied by light and electron microscopy. The clearance of IDE from rat plasma also was determined by analyzing free IDE particles in a counting chamber. The total white blood cell count remained essentially unchanged up to 40 minutes after the IDE injection, but the polymorphonuclear (PMN) neutrophil count decreased significantly. At 5 minutes postinjection, occasional PMNs contained ingested IDE particles, but by 40 minutes no intracellular particles could be found in the peripheral circulation. In vitro incubation experiments confirmed that human PMNs ingest IDE particles. In electron microscopy, the cells and particles seemed to be morphologically intact. Of the IDE particles counted at 5 minutes postinjection, only 4% remained in plasma at 30 minutes and none at 40 minutes. The decrease in PMN count apparently reflects sequestration of phagocytic cells from the circulation.

Animals↗

Contrast media-induced chromosomal damage in human lymphocyte cultures.

Ionic (diatrizoate, ioxaglate) and nonionic (iohexol, iosimide, iopromide, and iotrolan) contrast media (CM) were evaluated for their cytogenetic effects in lymphocytes. Heparinized blood was mixed with culture medium RPMI-1640 supplemented with phytohemagglutinin, fetal calf serum, and antibiotics. Plastic tubes containing blood samples were incubated at 37 degrees C in 5% CO2 humidified air for 48 hours. To these cultures, increasing amounts of CM were added and cells incubated for an additional 24 hours. After this exposure, red blood cells were lysed with hypotonic KC1, lymphocyte smears fixed on glass slides and stained with May-Grünwald Giemsa. Chromosomal damage was analyzed by a micronucleus test. All CM tested induced micronuclei in lymphocytes quite significantly (P less than .001) when compared with the frequency of micronuclei in controls. These observations on the genotoxic potential of nonionic CM suggest that factors other than ionic composition and osmolality are involved in clastogenesis; further studies are needed to establish the molecular mechanisms in CM induced chromosomal damage.

Cell Nucleus↗

Prostaglandin levels in human renal venous blood during renal arteriography.

In view of the possible role of prostaglandins (PG) and thromboxane (TX) in the disturbances of renal function and blood flow after the injection of diatrizoate into the renal artery, we have determined the levels of PGE2, 6-keto-PGF1 alpha (a stable metabolite of prostacyclin) and TXB2 in the renal venous blood before, during and after renal arteriography in 12 patients. Radioimmunologically assayed PGE2 was the most abundant prostaglandin in renal venous blood. Lower basal levels of PGs were associated with renal adenocarcinomas or other tumours than non-tumour kidneys. The concentrations of 6-keto-PGF1 alpha and PGF2 alpha rapidly increased after diatrizoate injection and returned to the basal levels within 5 minutes. Slower elevation was noticed in the PGF2 level of 5 tumour kidneys. Renal plasma concentration of TXB2 remained unchanged throughout the study. The rapid elevation of renal venous prostacyclin and PGF2 alpha concentration after the contrast injection may reflect the enhanced intrarenal prostaglandin synthesis or may be secondary to hemodynamic changes in the kidney caused by hypertonic diatrizoate.

6-Ketoprostaglandin F1 alpha↗

Ultrasonic echoes registered from erythrocytes.

Erythrocytes at various concentrations were examined with a sensitive A-mode ultrasonic scanner; simultaneous measurements were made under light microscopic control. Individual erythrocytes caused weak (about 1 dB) echoes while erythrocyte aggregates (ten to 100 cells) produced stronger echoes (up to 15 dB), grossly proportional to the size of the aggregates. The latter type echoes were characteristic of higher erythrocyte concentrations (hematocrit 0.1 - 0.8). It is concluded that these echoes originate from red cell aggregates within the stagnant blood.

Erythrocyte Aggregation↗

Correlation of the echogenicity and structure of clotted blood.

The echogenicity of clotting human blood in sterile plastic bags was studied for up to 21 days and correlated with the histology of the clots. As observed with a 6-MHz A-scanner and a 5-MHz real-time gray-scale scanner, fresh blood and fresh clots were rich in internal echoes. The blood clot gradually became anechoic as a result of erythrocyte packing, hemolysis, and formation of fibrin thrombus, except for the irregular upper border, which also remained histologically inhomogeneous. This study shows that the echogenicity of a hematoma or clot is dependent on its histology; namely, on the distribution and integrity of cells within the clot.

Blood Coagulation↗

Prostacyclin (PGI2) and thromboxane (TXA2) levels during intravenous contrast medium administration in CT.

Meglumine/sodium diatrizoate was administered as a one minute bolus of 60 ml. (60%) and subsequent 5 minute infusion of 250 ml. (24%) into antecubital veins during pelvic CT Scanning of 15 patients. Blood samples were taken from the opposite arm before and at 1 and 5 minutes after starting the contrast medium injection. The average plasma concentrations of diatrizoate were 2.2 +/- 0.5 and 3.8 +/- 0.8 mg./ml. in the 1 and 5 minute blood samples, respectively. The systemic levels of thromboxane A2 (TXA2) increased in 10 patient's plasma during contrast medium infusion while the level of prostacyclin (PGI2) remained unchanged. One patient had immediate adverse reaction due to contrast without any changes in PGI2 of TXA2 levels. Contrast medium infusion increased the systemic ratio of TXA2/PGI2 which may predispose to hemostatic disorders.

6-Ketoprostaglandin F1 alpha↗

Streak artifacts in dynamic CT. A phantom study of the anterior upper abdomen.

Experiments with a body phantom during dynamic CT scanning with the Somatom 2 CT scanner indicate that the periodic streak artifacts seen on the anterior part of the liver in patients are caused by peristalsis of the stomach and resulting motion of the air fluid level. Therefore, the attenuation values of the anterior portion of the liver artifactually oscillate around the baseline value during the dynamic series of scans. This artifact is produced by a change in the position of the stomach air fluid level and is dependent on the direction of tube rotation. The mean of the artifactually oscillating attenuation readings is close to the mean density but usually useless in dynamic CT because the attenuation values change so rapidly in the dynamic phase that averaging measurements also will cause errors.

Humans↗

Computer-tomographic evaluation of gynecologic tumors.

The accuracy of contrast-enhanced computer tomography (CT) of the pelvis in the detection, characterization and staging of known or suspected pelvic tumors was compared with clinical and operative findings in a prospective study of 79 patients (25 cervical carcinomas, 27 endometrial carcinomas, 10 ovarian carcinomas, 4 vulval or vaginal carcinomas and 13 benign ovarian or uterine tumors). In cervical carcinoma, there was a tendency towards lower staging of the tumor, especially in stage IIa, which is not easily detected in CT. Even small tumors of the cervix and endometrium can be visualized by contrast enhancement, which clearly delineates heavily vascularized myometrium and less enhancing tumor tissue. The accuracy of CT in tumor detection, characterization and evaluation of spread was best in ovarian neoplasms, weakest in cervical carcinomas. The importance of proper CT technique is stressed.

Carcinoma↗

Real time sonographic diagnosis of adrenal haemorrhage.

The diagnosis of adrenal haemorrhage in 4 infants using a linear real-time ultrasound scanner is described. The resolution of real-time equipment appears to be sufficient for such a diagnosis and its flexibility is well suited for small babies.

Adrenal Gland Diseases↗

Comparison of iohexol and metrizamide in dynamic CT of the upper abdomen.

Contrast enhancement (CE) of the aorta, liver and spleen obtained with non-ionic monomer of contrast media (CM) iohexol and metrizamide, was studied by dynamic computerized tomography in 18 and 14 patients, respectively. Six scans per minute were performed during 2 minutes and then single scans were taken at 3, 4 and 5 minutes after intravenous bolus doses of 18.5 g iodine. The mean CE and the pattern of washout with these two CM were similar in spite of their different molecular structure and physiochemical properties.

Aortography↗

Predicting malignancy of suspected ovarian tumours by CT.

The CT appearance of 47 clinically suspected ovarian tumours was analysed and compared to operative findings. By using simple differential diagnostic criteria, such as the relative amount of cystic and solid tumour tissue, presence of ascites and density readings, it was possible to correctly predict the malignancy of 18 out of 20 primary and 4 out of 5 recurrent ovarian tumours. In 6 out of 16 benign ovarian tumours or pelvic masses the CT pattern was either indeterminate or similar to malignant neoplasms. Since some non-ovarian tumours may produce an identical picture, the site of origin of large tumours could not be always detected. CT provides significant complementary information on the characteristics of suspected ovarian malignancies. A tumour which has a typical benign, cystic CT appearance is very likely benign, while some of the masses which contain solid tissue, consistent with a malignancy, may still be benign.

Adenocarcinoma↗

Dynamic topography of the contrast enhancement of the spleen.

Topographic variations of the contrast enhancement (CE) with time were studied in 74 dynamic CT scans of the spleen. After an 8-10 second bolus of urographic contrast medium containing 18.5 g. iodine, six scans per minute were done through the same section for two minutes, and single scan at 3, 4 and 5 minutes with a scanning time of 5.5 seconds. Early inhomogeneous CE of the normal spleen appearing 0-20 seconds after the peak CE of the aorta was found in 38 of 70 patients due to inhomogeneous parenchymal opacification (capillary phase) (19), delayed opacification of intrasplenic veins (8) or both (10) or due to other causes (1). Inhomogeneous CE in normal structures disappeared after 40 seconds from the aortic peak CE had elapsed, while all four pathological focal splenic lesions of different histology appeared as low density areas in postcontrast scans up to four minutes.

Adult↗