Biomedical subjects
Publications and source records attributed to M Just.
The typical findings of intracranial meningiomas seen in 24 patients are described. The signal intensities at different acquisition parameters are analysed and optimal pulse sequences derived from these data. In 90% of the patients MR-tissue parameters were measured and correlated with the histological findings. Marked prolongation of T2-times was found in tumours showing regressive changes.
The relatively rare neurocutaneous syndromes may produce neurological symptoms during childhood. After closure of the fontanelle, the radiological methods of choice are CT and MRT. The value of these two methods is demonstrated by twelve examples (eight neurofibromatoses, four tuberous scleroses). CT is superior to MRT in being able to show calcification; it is therefore the method of choice for tuberous sclerosis. On the other hand, MRT may show foci of neurofibromatosis; these can hardly be seen on CT. In order to show cerebral lesions in these two conditions, T2-weighted sequences are necessary.
69 Patients with benign brain tumours were examined via MRI (30 meningiomas, 17 pituitary adenomas, 14 acoustic neuromas, and 8 craniopharyngiomas). Typical morphological characteristics and values of the MR tissue parameters (T1, T2, Rho) are presented. The combined analysis of tissue parameters and morphological details allows a satisfying differentiation between different pathohistological entities. Tumour capsule and displacement of neighbouring structures without signs of infiltrating growth are typical criteria of benign neoplasms.
The value of MRI as a method for controlling treatment quantitatively was studied in four osteosarcomas and one Ewing sarcoma. Histologically proven change resulting from chemotherapy (2 patients) correlated with a significant increase in T2 of tumour tissue. In three other patients who did not respond to therapy, no change could be demonstrated. MRI appears to be valuable as a non-invasive method for monitoring treatment.
MRI-findings in a case of parenchymal neurocysticercosis are presented. The changes of the lesions as a response to chemotherapy were monitored by MRI and CT. Problems of sensitivity (MRI vs. CT) and MRI differential diagnoses are discussed.
A study of the immunogenicity and reactogenicity of three doses of lot L (10, 20, 40 micrograms), two doses of lot N (10, 20 micrograms) of the SmithKline Biologicals recombinant DNA yeast-derived hepatitis B vaccine and a 20 micrograms dose of the Merck, Sharp & Dohme plasma-derived hepatitis B vaccine was conducted in young adults under randomized, double-blind conditions. Immunization was carried out according to a 0, 1, and 6 month vaccination schedule. Results indicated that the yeast-derived hepatitis B vaccine was well tolerated and highly immunogenic. Reactogenicity to both yeast- and plasma-derived vaccines was mild in severity and low in incidence with no significant differences appearing between the study groups. One month after the third dose, the yeast-derived vaccines induced a high degree of seroconversion ranging between 97.8% and 100%. The response was not lot- or dose-dependent. The administration of the plasma-derived vaccine resulted in an anti-HBs geometric mean titre approximately twice as high as those elicited by the different yeast-derived hepatitis B vaccine doses one month after the third inoculation. However, 11 months following the third dose of vaccine, the anti-HBs titres were similar in all groups. Revaccination of subjects who no longer had detectable anti-HBs one year after the last vaccine dose resulted in an anamnestic response.
The effect of molsidomine on platelet function has been studied in various experimental models. Molsidomine prevented mortality induced by arachidonic acid as well as thrombocytopenia induced by collagenase, the combination of collagen plus adrenaline, or PAF-acether. Arterial bleeding time was prolonged. Carotid or coronary artery thrombosis and jugular venous thrombosis were inhibited. These effects were obtained in various animal species and were dose-dependent. They suggest the administration of molsidomine for the prevention of thrombotic disorders.
Within two and a half years 82 magnetic resonance imaging and 155 ultrasound examinations were performed in 46 children after treatment for brain tumors. In 42 cases the primary tumors were located in the posterior cranial fossa. Magnetic resonance imaging required sedation in 14 and anesthesia in 3 children. In 6 cases ultrasound was insufficient due to partial closure of the calvarian defect. In the remaining cases ultrasound was falsely negative in two cases, and falsely positive in one case. Magnetic resonance imaging was falsely negative in one case. Sequelae of chemo- and radiotherapy were only depicted by magnetic resonance imaging. For follow-up of tumors of the posterior cranial fossa after surgical treatment ultrasound is the method of choice.
36 Patients with glioblastomas (17 cases) and cerebral metastases (19 cases) were investigated by MRI. The typical signal behavior at different acquisition parameters (T1-, T1/T2-, Rho- and Rho/T2-weighted) was analysed using an interlaced triple sequence. In most cases the NMR-tissue parameter T1, T2 and proton-density (Rho) were determined to evaluate the potentials for tissue characterisation. The results of unenhanced vs. enhanced scans (MRI plus Gd-DTPA, CT) were analysed.
A case of multiple intracranial tuberculomas is presented. CT and MRI findings are discussed and compared. MRI showed multiple tuberculomas characterised by the same signal intensity as the surrounding brain parenchyma. Differentiation could be achieved only by the perifocal oedema of high signal intensity. Changes of the lesions during chemotherapy were monitored by CT and MRI and the results are presented.
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Sera of 47 patients with serious Staphylococcus aureus infections, 55 patients with septicemias caused by other organisms and 147 healthy controls were examined for teichoic acid antibodies by ELISA, counterimmunoelectrophoresis (CIE) and immunodiffusion (ID). The specificity and the predictive value of positive results for metastatic-septic complications were 100% each for ELISA, 93%/88% for CIE and 87%/80% for ID. The low sensitivity with all three test methods of 50-60% relates to single sera. The indication for prolonged antibiotic treatment should therefore be derived only from the analysis of consecutive serum samples. With 12% of the controls above the cut-off, the ID test seems not a very good screening test.
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Forty-seven children and adolescents with brain tumors were examined by magnetic resonance imaging (MRI) after tumor resection. The typical changes and complications after surgery and chemotherapy, as well as the corresponding MRI findings, are discussed. Typical examples of boundary-layer lesions, tumor recurrences, hydrocephalus, porencephalic cysts, and hygromas are given.
The prophylactic efficacy of low-dose intranasal recombinant leucocyte interferon alpha (rIFN-alpha A, Ro 22-8181) was investigated under field conditions in 147 families (n = 587 participants), randomized to receive placebo or rIFN-alpha A intranasally in daily doses of 1.5 or 0.3 X 10(6) IU. Treatment was started within 2 days after the appearance of an index case in the household and was continued for 5 days. Clinical data of the index case and of all members of the household were recorded for 10 days. In index cases and all ill contact persons nasal washes were collected for rhinovirus isolation and immunochemical detection of other respiratory viruses. The local tolerance of the intranasal rIFN-alpha A was excellent. Both doses of rIFN-alpha A failed to exert therapeutic effects on established common cold or to prevent the spread of common cold within families. Prophylactic treatment with 1.5 X 10(6) IU did however shorten the duration of the cold (median of 2 days vs. 4 in the placebo group, P = 0.01) and reduced the severity of any ensuing common cold (median total score of 10.5 vs. 30, P less than 0.001). No correlation was found between viral etiology (55% rhinoviruses vs. 13% other respiratory viruses, n = 122 nasal washes) and prophylactic efficacy or clinical severity.
Tumours of the brain, mesencephalon and cervical spinal cord in 10 children were examined by MRI. The most useful anatomical information was supplied by the sagittal midplane tomogram. Due to the prolongation of T2-times in brain tumours T2-weighted images were appropriate for detecting pathological structures even without space-occupying signs. Questions of operability and therapeutic effectiveness were reliably answered.
Synthetic images of the tumour region were computed in the case of ten meningiomas for the purpose of determining retrospectively pulse sequences and sequence parameters supplying an optimal contrast between tumour and adjacent tissue in plain imaging. It was found that best results were obtained via the partial saturation/spin-echo sequence with a long recovery time (TR approximately greater than 2,000 msec) and a long maximum echo delay (TE max approximately greater than 200 msec). A comparable contrast quality can be attained by using the inversion-recovery sequence with an inversion time T1 approximately 450 msec. Nevertheless, it was not possible in our study to identify two small meningiomas with a diameter of just below one centimetre by studying the MR tomogram.
There was neither a difference in the (low) percentage of only harmless side-reactions nor in the rate of sero-conversions (between 95-100%), when groups of 15 to 24 months old children were vaccinated either with the single components or with a combined MMR + Chickenpox-vaccine of a high potency.