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J C Kiwit

Publications and source records attributed to J C Kiwit.

31 records · Page 2Linked to original sources
PubMed1989

Investigations of brain tumours with 99Tcm-HMPAO SPECT.

The cerebral uptake of 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO) as measured with the use of single photon emission computed tomography (SPECT) was studied in 66 patients with various types of brain tumours and quantified by tumour-to-cerebellum ratios. The uptake of 99Tcm-HMPAO by gliomas and meningiomas showed wide ranges of values. There were no significant differences among primary malignant gliomas (0.75 +/- 0.27, n = 25), recurrent malignant gliomas (0.81 +/- 0.25, n = 14) and benign gliomas (0.77 +/- 0.21, n = 9). Compared to gliomas, meningiomas exhibited a significantly higher 99Tcm-HMPAO uptake (1.14 +/- 0.31, n = 13, p less than 0.001) while the remaining four patients with tumours of various histopathology showed a low 99Tcm-HMPAO uptake. Three of the 66 patients were scanned immediately and again 2 h after injection and they revealed a decrease in tumour activity. No changes in the pattern of uptake were observed in two patients with gliomas which were studied before and after intra-arterial chemotherapy, but a decrease in tumour uptake was found in the glioma patient who was studied before and after radiotherapy. The results obtained with 99Tcm-HMPAO SPECT are in agreement with those on regional cerebral blood flow (rCBF) in brain tumours reported in the literature.

Brain Neoplasms↗
PubMed1989

Early effects of intra-arterial chemotherapy in patients with brain tumours studied with PET: preliminary results.

In ten patients with malignant gliomas the regional cerebral metabolic rate for glucose (rCMRGlc) was studied with positron emission tomography (PET) using 2-18F-deoxyglucose (18FDG) before and within 1 to 7 days after intra-arterial chemotherapy with the nitrosourea derivative ACNU (iaACNU). Three patients were studied before and after two iaACNU courses and one patients before and after three iaACNU courses. The early effects of iaACNU on tumour rCMRGlc were highly variable and appeared to be more pronounced after the first course of iaACNU than in later iaACNU courses, i.e. more pronounced in untreated patients. Although there was no clear correlation between the change of rCMRGlc following the first course of iaACNU and the clinical outcome in this small group of patients, the patient with the most pronounced decrease of tumour metabolism (-16.5%) after the first course of iaACNU exhibited full tumour remission for 12 months, while the patient with the most pronounced increase of tumour metabolism (+65%) after the first course of iaACNU developed rapid tumour progression. The first results indicate that early effects of intra-arterial chemotherapy may be observed with 18FDG PET, especially following the first course of iACNU. Further studies are needed to evaluate the predictive value of such studies for therapy response.

Adult↗
PubMed1988

Tomographic studies of rCBF with [99mTc]-HM-PAO SPECT in patients with brain tumors: comparison with C15O2 continuous inhalation technique and PET.

In 10 patients with malignant gliomas, the intracerebral distribution of [99mTc]-hexamethylpropylene-amine oxime [( 99mTc]-HM-PAO) was studied with single photon emission computed tomography (SPECT) in comparison with C15O2 steady-state inhalation technique to measure cerebral blood flow using positron emission tomography (PET). In all instances, the cerebral [99mTc]-HM-PAO distribution was comparable with the regional pattern of cerebral blood flow (rCBF) observed with PET. This was confirmed by a significant correlation of tumor to cortex and tumor to white matter ratios between these two experimental methods. However, the contrast between high and low activity regions in the SPECT scans was significantly less than that in the PET scans. Contrast enhancement of the SPECT scans was accomplished using a correction formula proposed by Lassen.

Brain Neoplasms↗
PubMed1988

[Plasma ANP levels and its relation to electrolyte and water regulation in neurosurgical intensive care patients].

We examined the relation between plasma atrial natriuretic peptide (ANP) and the changes of the regulating hormones ADH and renin aldosterone in 20 neurosurgical intensive care patients. All patients suffered from elevated intracranial pressure due to severe head trauma or severe subarachnoidal hemorrhage of the anterior circulation. Under controlled mechanical hyperventilation (CMV) with PEEP, 15 patients without evidence of central dysregulation showed no change in plasma ANP, ADH and aldosterone. In five patients with severe central dysregulation of either electrolytes or blood pressure, increases of plasma ANP of various degrees could be observed together with a decline in serum aldosterone.

Aldosterone↗
PubMed1987

The influence of magnetic resonance tomography on diagnosis and therapy in patients with intracranial manifestation of neurofibromatosis (Recklinghausen disease).

Recent research into the natural course of neurofibromatosis has revealed an outstandingly high proportion of central nervous system malignancies as well as cancers of various other organs. Due to the lack of ionizing radiation, the extraordinary reconstruction in the frontal and parasaggital planes as well as the diagnosis of intracanalicular acoustic neurinomas and intraorbital tumors, magnetic resonance tomography (MRT) is indicated for control of patients with neurofibromatosis.

Adolescent↗
PubMed1986

Osteoclastomas of the petrous bone.

Two cases of osteoclastoma of the petrous bone are presented that were clinically taken for tumors of the glomus jugulare. The petrous bone is a very uncommon location for such tumors, and only six cases have been reported in the English literature. The histopathological features as well as the clinical course are described, and the literature is critically reviewed.

Female↗
PubMed1986

RG2 glioma growth in rat cerebellum after subdural implantation.

The nitrosourea-induced rat glioma clone RG2 was tested for its capacity to form multicellular tumor spheroids (MTS's). Resulting spheroids were investigated by light and electron microscopy with regard to their proliferation patterns and morphological features. Using microsurgical techniques and avoiding mechanical injury of the brain tissue, the authors successfully transplanted avascular MTS's under the dura of the cerebellum, above the vermis, in 43 adult syngeneic Fischer CD rats. The rate of tumor establishment was 93%, and the tumors that were solid and spheroid in shape grew exponentially. Neovascularization could be observed at 3 days after implantation, and invasion of the cerebellum occurred by 3 to 5 days. Neurological deterioration, including ataxia, impairment of walking, and apathy, could be observed after 10 days. The mean survival time was approximately 16 days. The subdural cerebellar tumors were studied by histological techniques, and two morphometric methods were applied to check the growth of implanted spheroids. All tumors were deeply stained with the Evans blue dye-albumin complex, demonstrating disturbance of the blood-brain barrier. The easy accessibility of the cerebellar vermis in rats, the microsurgical implantation of glioma spheroids under the dura avoiding nerve tissue disruption, and the high percentage of reproducible establishment of tumors favor this experimental brain-tumor model. This should be an excellent model for study of experimental therapies.

Animals↗
PubMed1986

Intra-arterial chemotherapy with ACNU for the treatment of glioblastoma. Preliminary experience.

In November 1985, we started a study of intra-arterial (i-a) chemotherapy with ACNU for the treatment of glioblastomas of the central nervous system: 19 patients with histologically proved glioblastoma and recurrent, progressive or newly diagnosed disease were entered. Five patients were treated three times. We observed reduction of mass effect, of neovascularization, and of contrast enhancement. As to the time of survival, or follow-up is too short to allow definite conclusions. The quality of life in those patients who received several courses of chemotherapy, did not deteriorate as evidenced by a constant Karnofsky performance rating score. Systemic complications of i-a chemotherapy were negligible. However, some severe side-effects were seen: cerebral ischemia in two cases, and amaurosis in one. Direct ACNU related neurotoxicity was not seen to the present. According to these preliminary results, we feel encouraged to treat further patients with i-a chemotherapy, particularly in view of the disappointing results of several other treatment modalities in the management of glioblastomas of the brain.

Adult↗
PubMedDate not supplied

In vivo MRI thermometry using a phase-sensitive sequence: preliminary experience during MRI-guided laser-induced interstitial thermotherapy of brain tumors.

The purpose of this study was the application of the proton-resonance-frequency method to monitor laser-induced interstitial thermotherapy (LITT) in a patient with an astrocytoma WHO II. A phase-sensitive two-dimensional (2D) fast low-angle shot (FLASH) sequence was used to determine the temperature-related phase shifts during LITT. Temperature maps were displayed during therapy with a temporal resolution of 20 seconds. Irradiation was discontinued as soon as the 60 to 65 degrees C isotherm reached the margin of the tumor. A contrast-enhanced MRI study performed immediately after therapy showed a good correlation of the size of an enhancing rim around the lesion with the 60 to 65 degrees C isotherm. The preliminary results of our study indicate that MRI guidance of LITT may be improved by temperature quantification based on the proton-resonance-frequency method.

Astrocytoma↗
PubMedDate not supplied

Pleomorphic xanthoastrocytoma with desmoplastic reaction: angiomatous variant. Report of two cases.

Two cases of cerebral pleomorphic xanthoastrocytomas (PXA-s) with prominent vascularity and desmoplastic changes occurring in young subjects are presented. The tumors displayed the marked pleomorphism characteristic of PXA-s and had variable cellularity. The cytoplasm of many tumor cells contained an abundance of lipid droplets. Most tumor cells were positive for glial fibrillary acidic protein. The unusual feature about these tumors was the presence of very large numbers of tiny blood vessels with variable thickness of their walls. In many areas the small vessels and the neoplastic astrocytes were in close proximity to each other, with capillaries adjacent to or protruding into tumor cell cytoplasm, reminiscent of the pattern seen in highly vascularized or "angiomatous" meningiomas. In other areas extensive fibrosis was seen. We feel that the latter, as in the cases of comparably vascular meningiomas, had its origin in congelation and secondary organization of plasma proteins that have exuded through leaky walls of newly formed blood vessels. These are the first reported cases of PXA with an angiogliomatous pattern.

Adult↗
PubMedDate not supplied

[Critical analysis of fetal risk recognition by serum estriol determination].

In 901 pregnancies between 1978-1981 a total of 5281 serum estriol determinations were performed. 596 gravidas were high-risk patients (diabetes mell., toxemia, IUGR, premature labour, prolonged pregnancy, Rh incompatibility). In 142 of these high-risk pregnancies the estriol values were below the 10th percentile or the estriol decrease extended 40%. These cases were analysed individually, in order to answer the question, how often serum estriol values were decisive for active obstetrical management. Our data show that a drop of estriol over 40% was very rare (0.53%). For the newborn such an estriol-drop does not mean higher perinatal morbidity or mortality in any case. The endocrine parameters were not very often decisive for an active obstetrical intervention. Probably because of the large fluctuations and day-to-day-variations of the estriol values mainly due to drugs which were widely used in risk pregnancies. These exogenous factors had a negative effect on the clinical value of the serum estriol determinations.

Estriol↗