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K Kitz

Publications and source records attributed to K Kitz.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Stereotaxic biopsy of cerebral lesions. Results based on a series of 250 cases].

With the help of modern computer-assisted imaging techniques, direct evidence of intracerebral lesions can be provided earlier and in more detail, often before the patient begins to exhibit symptoms. In asymptomatic cases, however, it is often difficult to establish an indication for a certain therapy. The choice of treatment chiefly depends on the histological nature of the lesion. Even in the age of computer-assisted imaging techniques, the specific diagnosis can only be made under the microscope. CT-guided stereotactic biopsy is a valuable and safe diagnostic tool for classifying intracranial lesions. It provides the basis for selecting the appropriate therapy, whether it be surgery, radiotherapy, or conservative treatment. We present a series of 250 stereotactic biopsies. The indications, technique, complications and limits of the method are discussed, as well as the diagnostic yield which achieved 97.6% in our series.

Biopsy, Needle↗
PubMed1991

Proliferation in pituitary adenomas: measurement by MAb KI 67.

The monoclonal antibody MAb KI 67 reacts with a nuclear antigen throughout the entire cell cycle and allows easy evaluation of proliferating tumour cells on routinely prepared smear and frozen sections. 120 pituitary adenomas were investigated by use of the monoclonal antibody KI 67 in a two-step avidin-biotin-peroxidase complex (ABC) technique. The KI 67 labelling index (LI) ranged in all adenomas from 0.2 to 4.6%. In 90 cases of transphenoidally operated adenomas the dura of the sella floor was investigated histologically. Adenomas with histologically proven dural infiltration showed a statistically significant higher KI 67 LI (p less than 0.001) compared to non-invasive adenomas.

Adenoma↗
PubMed1991

Pituitary adenomas with parasellar invasion.

Pituitary adenomas with extension into the parasellar space, the so called "cavernous sinus" can be demonstrated best using MRI. To improve the delineation from the venous compartments the use of unenhanced and enhanced MRI scans is essential. In 25 pituitary adenomas with surgically proven infiltration into the space of the cavernous sinus we correlated the MRI findings with our surgical observations. When the adenoma encases the intracavernous internal carotid artery or reaches as far as to the lateral aspect of the artery, invasion was present in all cases. The critical area where invasion could not be predicted from MRI is the distance between the medial and the lateral aspect of the intracavernous internal carotid artery. By measurement with the monoclonal antibody KI-67 it could be shown, that pituitary adenomas infiltrating the parasellar space have a statistically significant higher growth rate (p less than 0.001), compared to non-invasive adenomas. This is of special interest, because surgical cure becomes unlikely, when invasion into the space of the cavernous sinus is present.

Adenoma↗
PubMed1991

Diagnostic potential of stereotactic biopsy of midline lesions.

The technique of CT-guided stereotactic biopsy is described and its reliability is discussed based on the experiences with a series of 1747 procedures. We could show that stereotactic biopsy has an overall diagnostic accuracy of 95% and therefore is a safe and reliable tool for planning the therapeutic strategy.

Biopsy↗
PubMed1991

Determination of proliferative activities in human brain tumor specimens: a comparison of three methods.

Proliferative activities were determined in 72 human brain tumors, including 20 metastatic carcinomas, 41 gliomas, 8 meningiomas and 3 hematological tumors. Immunocytochemical techniques included labeling with monoclonal antibody (mAb) to bromodeoxyuridine (BrdU) which identifies S phase cells after previous in vitro BrdU incubation and paraffin embedding of fixed tissue specimens, and with mAb Ki-67 which reacts, in frozen sections, with a nuclear antigen expressed by all proliferating cells. BrdU labeling index (LI), Ki-67 LI and mitotic index (MI) correlated well with histological malignancy. Among the three proliferation indices, Ki-67 LI and BrdU LI were highly significantly correlated. With the exception of hematological malignancies, hyperbaric oxygenation of in vitro BrdU labeling did not significantly increase BrdU LI or depth of BrdU penetration into tissue. This study indicates that in vitro BrdU labeling is a useful alternative to Ki-67 immunolabeling of human brain tumor specimens. By such determination of tumor proliferation, it might be possible to design a more adequate postoperative therapy tailored to patients individually.

Antibodies, Monoclonal↗
PubMed1990

Monocyte subpopulations in human gliomas: expression of Fc and complement receptors and correlation with tumor proliferation.

Cryostat sections of 12 gliomas and of 3 peritumoral brain tissue samples were investigated for mononuclear cell infiltration by immunohistochemistry, concentrating on cells expressing monocyte/macrophage markers. Only low numbers of T cells were detected in the tumors, whereas in average 20%-30% of all cells present in the samples were recognized by various macrophage markers. These cells carried surface epitopes with known function, like Fc-gamma (Fcg) and complement receptors. Microglial cells, in comparison to typical debris laden macrophages, were only recognized by a restricted panel of macrophages markers (anti-Fcg receptors 1, 2, 3, complement receptor CR3, HLA DR, common leucocyte antigen CD45 and the monocyte marker RM3/1). In peritumoral tissue mainly dendritic, microglia-like cells were present, which revealed decreased expression of antigens CD4, RM3/1 and Fcg receptors in comparison to those in gliomas. A significant positive correlation was found between the number of RM3/1 or CR3 (CD11b)-positive cells and the proliferation rate of the tumors as documented by the number of bromodeoxyuridine-positive or Ki-67+ cells.

Antigens, CD↗
PubMed1990

Argyrophilic nucleolar organizer region proteins (Ag-NORs) in human brain tumors: relations with grade of malignancy and proliferation indices.

Proliferation indices and mean number of silver-stained nucleolar organizer region-associated proteins (Ag-NORs) are compared in 65 brain tumors, including 34 gliomas, 8 meningiomas, 17 metastatic tumors, and 6 other tumors. Immunocytochemical investigations include labeling with the monoclonal antibody Ki-67 which identifies the whole growth fraction, and with a monoclonal antibody against bromodeoxyuridine (BrdUrd) which detects cells in the S phase of the cell cycle after in vitro incubation with BrdUrd. When all types of tumors are collectively considered, mean numbers of Ag-NORs did not correlate with Ki-67 and Brd-Urd labeling indices (LIs) and mitotic index. Among tumor subtypes, only meningiomas showed significant correlations between Ag-NOR counts, LIs, and malignancy. Mean number of Ag-NORs did not correlate with proliferation indices and tumor grade in low-grade and high-grade gliomas. However, recurrent high-grade gliomas showed a tendency to higher Ag-NOR counts than primary tumors. This study indicates that counting of Ag-NORs in paraffin sections is of limited value in tumor neuropathology. Correlations found in meningeal tumors should be substantiated in larger series.

Adult↗
PubMed1989

[Stereotaxic biopsy of intracranial processes: validity of histologic diagnosis].

The diagnostic validity of stereotactic intracranial biopsies was investigated in 70 patients retrospectively. In 56 cases (80%) the presence of a neoplastic lesion as well as its grade of malignancy was proved by cytological, histological and immunohistochemical techniques. An inflammatory or vascular lesion was found in 8 patients (11.4%). In 6 patients (8.6%) the nature of the lesion remained unclear because of nonspecific histological findings. In 27 cases a correlation was found between the biopsy specimens and corresponding material obtained during open surgery or autopsy. 24 concordant results were found (88.9%). In one case a malignant tumour was classified only according to the findings obtained at operation. In two cases subsequently diagnosed as glioblastoma biopsy reported a higher differentiated astrocytoma and a non-neoplastic lesion, respectively. These results confirm stereotactic biopsy of intracranial lesions as a method with low complication rate and high diagnostic validity.

Astrocytoma↗
PubMed1989

In situ analysis of cell kinetics in human brain tumors. A comparative immunocytochemical study of S phase cells by a new in vitro bromodeoxyuridine-labeling technique, and of proliferating pool cells by monoclonal antibody Ki-67.

A newly developed in vitro labeling method with bromodeoxyuridine (BrdU) identifies S phase cells in situ in freshly obtained surgical tissue of human brain tumors which is subsequently fixed and embedded in paraffin for BrdU immunovisualization. For the first time, the BrdU labeling index (LI) is successfully compared here with the LI obtained by immunostaining of frozen sections of the same tumors with monoclonal antibody Ki-67 which identifies all proliferating cells, i.e., the growth fraction. LIs were counted in at least five different areas with high density of labeled cells; at least 1,000 cells were counted. In 13 metastatic tumors, Ki-67 LI was 8.3%-62.6%, and BrdU LI was 5.1%-28.0%. In 18 gliomas, Ki-67 LI was 1.4%-19.3%, and BrdU LI was 0.2%-11.6%. In 7 meningiomas, Ki-67 LI was 0.3%-3.0%, and BrdU LI was 0%-2.0%. Statistical comparison of Ki-67 and BrdU LIs by linear regression analysis revealed a highly significant correlation: BrdU LI = 0.99 + 0.34 Ki-67 LI (r = 0.92, P less than 0.001). A significant heterogeneity of proliferation patterns may occur within one sample from area to area, as well as between different samples of the same tumor, especially in gliomas; thus, some subjective influence on LIs by arbitrary sampling and selection could occur in quantitative evaluation of in situ cell kinetics of human brain tumors. This study indicates that our in vitro BrdU-labeling method allows the in situ identification of S phase cells in excellently preserved fixed tumor tissue which is well suited for further histological examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1989

Proliferation activity in pituitary adenomas: measurement by monoclonal antibody Ki-67.

The monoclonal antibody (MAb) Ki-67 detects a nuclear antigen expressed by proliferating cells during the entire cell cycle. In contrast to conventional histological techniques, the use of MAb Ki-67 on frozen sections or cytological smear preparations allows direct determination of the growth rate of tumors routinely. Sixty-two pituitary adenomas were investigated by use of the MAb Ki-67 in a two-step avidin-biotin-peroxidase complex technique. The proliferation activity ranged from 0.1 to 2.8%. There was no significant difference between the proliferation and hormonal state of the adenomas. Adenomas for which there was histological evidence of dural infiltration, however, showed a statistically significant higher proliferation activity (P less than 0.05) compared to noninvasive adenomas.

Adenoma↗
PubMed1987

[Stereotaxic biopsy of brain tumors].

The management of patients with a brain tumour is essentially dependent on the knowledge of the histology. Because of its high accuracy and low complication rate stereotactic tumour biopsy has proven to be an important diagnostic procedure, especially in deep-seated lesions. Stereotactic tumour biopsy was carried out in 18 patients with target calculation either from computerized tomography (CT) or magnetic resonance imaging (MR).

Adult↗
PubMed1986

Ganglioside GM1, a molecular target for immunological and toxic attacks: similarity of neuropathological lesions induced by ganglioside-antiserum and cholera toxin.

Ganglioside-antisera, the ganglioside GM1-ligands, cholera toxin (CT), and CT subunit B, respectively, were injected into the lumbosacral subarachnoid space of normal rats. The cytotoxic effects of the injected compounds on the peripheral and central nervous system were investigated by light and electron microscopy; the severity of CNS lesions was evaluated by quantitation of macrophages containing debris. In contrast to control sera and GM2-antiserum, antisera against a mixture of the major brain gangliosides GM1, GD1a, GD1b, and GT1b (MaBG) or against GM1 induced demyelination in spinal roots and spinal cord, as well as alterations of astroglia. CT induced the same cytotoxic effects as MaBG- and GM1-antisera, whereas CT subunit B was without effect. The ineffectiveness of GM2-antiserum is obviously due to the very low concentration of the specific binding target, GM2, on cell surfaces; that of CT subunit B to the lack of the cytotoxic operator, subunit A. Our results indicate that a similar pattern of neuropathological lesions may be effected by different cytotoxic mechanisms through attachment of the cytotoxic agent onto the cell surface via a common target molecule, and further substantiate the role of GM1-antibodies in the pathogenesis of demyelination.

Animals↗
PubMed1986

[Visual field fluctuations in necrotic hypophyseal adenoma].

The authors report on an acute bitemporal visual field depression with spontaneous reversibility of the defects, associated with necrotic pituitary adenoma. As the same time as the visual field defects regressed it was established by computer tomography that the suprasellar portion of the pituitary tumor had diminished in size.

Adenoma↗
PubMed1984

Blood-brain barrier in chronic relapsing experimental allergic encephalomyelitis: a correlative study between cerebrospinal fluid protein concentrations and tracer leakage in the central nervous system.

Blood-brain barrier (BBB) permeability in chronic relapsing experimental allergic encephalomyelitis was studied morphologically in tracer studies with horseradish peroxidase (HRP) as well as by quantitative determination of HRP, albumin, and IgG in serum and cerebrospinal fluid (CSF). BBB damage was found to be localized in demyelinating plaques and in blood vessels with vasculitis. Actively demyelinating lesions showed massive increase in BBB permeability, whereas in inactive or remyelinated lesions BBB damage was either minimal or absent. Determination of serum proteins in the CSF of animals with severe disease and a high incidence of actively demyelinating lesions showed evidence of BBB damage (reduction of Q-albumin) and an IgG-index in the normal range. In animals with only inactive lesions the Q-albumin was normal, the IgG index, however, was elevated. This finding indicates intrathecal IgG synthesis. A correlation between morphologically visualized tracer leakage in the central nervous system (CNS) with serum protein concentrations in the CSF revealed that elevated CSF albumin is a reliable indicator for BBB damage in lesions, located near the inner or outer surface of the brain and spinal cord. However, singular focal lesions with BBB damage located in the depth of the CNS parenchyma may not be accompanied by CSF protein alterations. The invariable presence of BBB damage in active inflammatory demyelinating lesions and its absence in inactive plaques or in the unaffected nervous tissue may be important in therapy, not only in experimental allergic encephalomyelitis but also in multiple sclerosis (MS).

Animals↗
PubMed1984

The role of brain edema in epileptic brain damage induced by systemic kainic acid injection.

Edema formation and blood-brain barrier permeability was studied in animals with epileptic seizures induced by subcutaneous injection of kainic acid. Brain edema was most pronounced between 3 and 24 h after kainic acid injection. It was reflected by massive swelling of perineuronal and perivascular astroglia. Three hours after kainic acid perivascular astroglia swelling resulted in disturbance of local microcirculation in the affected brain areas. In addition, compression of drainage veins by the edematous brain induced focal perivenous hemorrhages similar to herniation damage in human brain edema. Tracer studies with sodium fluorescein, Evans blue, albumin and horseradish peroxidase revealed only a mild increase in the permeability of cerebral vessels, topographically unrelated to areas of brain edema. This finding indicates the presence of cytotoxic brain edema in kainic acid-induced epileptic brain damage. Treatment of brain edema with dexamethasone did not influence the incidence and severity of kainic acid-induced epileptic brain damage. However, in 54% of animals injected with kainic acid, lesions were completely prevented by treatment of brain edema with mannitol. The present results indicate that brain edema plays an important role in the pathogenesis of epileptic brain damage following systemic kainic acid intoxication. It is suggested that in this model of limbic epilepsy the brain edema is due to the massive ionic imbalance elicited in the affected brain regions by the kainic acid-induced persistent neuronal excitation.

Animals↗