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S Krajewski

Publications and source records attributed to S Krajewski.

At least 181 records · Page 10Linked to original sources
PubMed1991

Development of subrenal capsule tumours following transplantation of rat RN6 multicell spheroids.

We describe here the growth rate, morphology and ultrastructure of the RN6 neurinoma spheroids in culture and after syngeneic transplantation under the renal capsule of adult BDIX rats, where sequential growth and tumour angiogenesis studies were performed. The tumour cells in solid avascular multicell spheroids (MTS) and in subrenal capsule tumours (SCT) showed similar morphology and ultrastructure. The vascularization of spheroids started 2 to 3 days after implantation under the renal capsule from proliferating venule-like vessels of the kidney parenchyma. The MTS were soon densely penetrated by hairpin loops of newly formed capillaries. Such vascularized spheroids grew rapidly. The morphology, ultrastructure and permeability characteristics of newly formed tumour vessels and their relationship to the development of tumour necrosis are described. This syngeneic model of subrenal capsule transplantation of neurogenic tumour spheroids appears to be useful for studies of the mechanisms of tumour angiogenesis, tumour necroses and the host response to malignant tumours of the nervous system.

Animals↗
PubMed1991

Do astroglial cells participate in the process of human spinal cord myelination?

The material comprised spinal cord segments C8 or Th1 of 6 human fetuses aged from 16-17 up to 34 weeks and 6 infants aged from one day to 3 years. On formalin-fixed, paraffin-embedded sections, peroxidase-antiperoxidase Sternberger's et al. (1970) method for visualization of astrocytic proteins (S-100 and GFAP), myelin basic protein (MBP) and neuron specific enolase (NSE), was used. Parallelly to the increasing immunoreactivity to MBP, more S-100 and GFAP-positive cells were observed. Immunoreactivity to S-100 was more distinct in astrocytic perikarya, whereas, in GFAP reaction immunostaining of astrocytic processes was more pronounced. It is very difficult to explain why reactivity of astrocytes appears during myelination.

Age Factors↗
PubMed1990

[Brain infarcts in humans during middle age and senility. I. Defects of blood-brain barrier permeability in immunocytochemical studies].

Brains of the deceased in the age from 45 to 57 years (6 cases) and from 80 to 101 years (9 cases) with ischemic brain damage were studied. Technique of the peroxidase-antiperoxidase (Sterberger et al. 1970) was used for visualization of the brain tissue reactivity for albumin, IgG, alpha 1-antitrypsin and alpha 2-macroglobulin. In all cases the disturbances of the blood vessels permeability were found. The BBB deterioration within the first days of brain infarct seems to be smaller in senile age than in middle age. However, after some days senile blood vessels permeability increases and become similar in both age groups.

Aged↗
PubMed1990

Enhanced immunocytochemical staining sensitivity in formalin-fixed and paraffin-embedded material by simultaneous use of PAP and ABC.

The simultaneous use of two immunoperoxidase (IP) methods; e.g. the PAP (Peroxidase-antiperoxidase) and ABC (Avidin-Biotin) to localize a single antigen enhances the sensitivity of polyclonal antibodies (FVIII/RAg and laminin) or monoclonal antibodies (MABs) (against human B-, T-cells and macrophages) in routinely formalin fixed and in paraffin embedded material. The increased sensitivity was not accompanied by loss of specificity. With antibodies against Factor VIII related antigen (FVIII/RAg) and laminin the increased staining intensity of blood vessels were demonstrated in experimental rat transplantation tumors. The similar enhancement of immunocytochemical reactions was observed with biopsies of human brain tumors, where the monoclonal antibodies against white blood cells were used. The staining results were of comparable intensity as in snapfrozen tissue or after special embedding procedure for immunocytochemical purposes acc. to Bolton and Mesnard formol sucrose gum, sucrose paraffin; FSGSP).

Animals↗
PubMed1989

Experimental transplantation gliomas in the adult cat brain. 2. Pathophysiology and magnetic resonance imaging.

In adult cats experimental brain tumours were produced by stereotactical xenotransplantation of the rat glioma clone F 98 into the internal capsule of the left hemisphere. Two to four weeks after transplantation tumours and peritumoural oedema were investigated by magnetic resonance imaging (MRI), electrophysiological recording and analysis of tissue content of water, electrolytes and extravasated serum proteins. Spherical tumours with a diameter of about 10 mm developed at the injection site and were surrounded by massive white matter oedema. Water content in peritumoural white matter increased from 2.63 +/- 0.17 to 3.65 +/- 0.19 ml/g d.w. (means +/- SD), sodium from 187 +/- 11 to 351 +/- 55 mueq/g d.w. and calcium from 7.4 +/- 1.1 to 13.3 +/- 1.3 +/- 1.3 mueq/g d.w. Potassium and magnesium did not change. Oedema development was associated with the extravasation of 18.0 +/- 16.8 mg/g d.w. albumin and 15.8 +/- 12.2 mg/g d.w. immunoglobulin. The calculated electrolyte content of oedema fluid approximated that of plasma but the serum protein content was about 40% lower. The ratio of low (albumin) to high (immunoglobulin) molecular weight proteins was the same in blood and oedema fluid. It is, therefore, concluded that peritumoural oedema consist of two components, a whole plasma extravasate and a protein-free ultrafiltrate. Peritumoural oedema could be clearly detected by MRI but differentiation between tumour and oedema was only possible after contrast enhancement with gadolinium-DTPA. The ratios of the intensities of the MR signal correlated linearly with the water content within white matter. MRI, in consequence, allows quantification of oedema provided a reference area with normal water content is present.

Animals↗
PubMed1987

Distribution of anti-Leu-7, anti-Leu-11a and anti-Leu-M1 immunoreactivity in the brain of the adult rat.

This study reports a specific cross-reactivity of the three anti-human-hematopoietic-cell monoclonal antibodies, anti-Leu-7 (HNK-1), anti-Leu-11a (NKP-15), and anti-Leu-M1 (MMA), with different epitopes in the brain of the adult rat. The distribution of these epitopes in rat brain is determined by means of immunohistochemistry in paraffin-embedded frontal serial sections. The reaction pattern of anti-Leu-11a monoclonal antibody is very similar to that of polyclonal antibodies against the myelin basic protein. Both antisera give a specific reaction with myelinated fibers. Immunoreaction products with the anti-Leu-7 monoclonal antibody are found as diffuse, mostly punctiform material in the neuropil and even more evident as small granules coating the cell surface of many neurons. In the white matter anti-Leu-7 reveals a moderate reactivity, which occurs predominantly as spots and fine-stranded material within the myelinated fiber tracts. Anti-Leu-M1 immunoreactivity is present between myelinated fiber bundles of the white matter, where it has a reticulate appearance, and as fine-granulated material within the grey matter of the cortex and the nuclei. The characteristic feature in the grey matter is that of irregularly shaped immunopositive plaques, which are often located around small blood vessels. The cytoplasm of glial and neuronal cells appeared negative with this MAB. The exact topographical distribution of the Leu-7 and Leu-M1 epitopes throughout the rat brain is described. The present hypotheses concerning the nature of this shared antigenicity between hematopoietic cells and nervous tissue are discussed.

Animals↗
PubMed1987

Prolonged extracorporeal CO2-removal in severe adult respiratory distress syndrome. Neuropathological observations in two cases.

Extracorporeal CO2-removal (EC-CO2-R) using a membrane lung system was applied for 12 and 20 days respectively in two young men with adult respiratory distress syndrome (ARDS). Neuropathological examination revealed only moderate hypoxic changes of unusual distribution. In the first case nerve cell loss in Sommer's sector of the hippocampus and focal incomplete necroses in both putamina were interpreted as the result of cardiac arrest at the onset of the disease rather than of chronic hypoxia. Findings in the second case were confined to nerve cell necroses of a minor degree in the cerebral cortex. Remarkably, the cerebellum was spared in both cases. Our observations suggest that EC-CO2-R was not associated with neuropathological findings which could be attributed specifically to this procedure.

Adolescent↗
PubMed1986

Subcapsular renal transplantation of neurogenic tumors and tumor spheroids. A comparative study of RN6 and RG2 tumor clones after syngeneic and allogeneic transplantation.

The subcapsular renal transplantation tumor model was explored to standardize the growth of rat RN6 neurinoma and RG2 glioma nitrosourea-induced clonal cell lines in syngeneic and allogeneic systems. Growth of RN6 and RG2 tumor spheroids was compared with that of solid subcutaneous tumor pieces transplanted under the renal capsule. Two morphometrical methods were applied to evaluate growth rates. Tumor specimens were examined histologically with regard to their morphology, extent of immune reactions, and development of tumor necroses. The take rate was 98%. In the syngeneic system linear progressive tumor growth was found, while in preirradiated allogeneic rats this was only the case up to 21 to 25 days post transplantation (p.t.). Strong rejection reactions in the allogeneic RN6 tumors were noted from 4 to 7 days p.t. resulting in total tumor rejection after 10 to 14 days. Both kinds of tumors, especially in the first days of growth, were characterized by strong desmoplastic reaction with rich reticulin fiber formation. However, after 10 days, in the center of RG2 subcapsular renal tumors (SRT) this kind of reaction was found only in the vicinity of tumor vessels, while RN6 SRT demonstrated reticulin fibers around tumor cells in all cases studied. The transplantation experiments revealed that the malignant RN6 and RG2 spheroids represent a suitable tool to study three-dimensional early tumor growth in both in vivo and in vitro cultures. The model of spheroid transplantation under the renal capsule is simple to handle and well reproducible. Compared with subcutaneous tumors the SRT model has advantages in early stages of tumor growth because the tumors are clearly visible grossly and can be easily submitted to adequate morphometry, indicating that this model may be suitable for experimental chemotherapy and radiotherapy studies.

Animals↗
PubMed1986

Binding specificity of two monoclonal antiglioma antibodies: immunocytochemical studies using a new tissue embedding technique.

The binding specificities of two monoclonal antiglioma antibodies (MAB) derived from hybrids GE2 and BF7 (Schnegg et al. 1981) were tested by indirect immunofluorescence (IF) and two immunoperoxidase (IP) methods. Studies were done on biopsies from 33 human CNS tumors, human derived glioma cells, and N-ethylnitrosourea-induced neurogenic rat cells in culture. The immunohistochemical reactions of MAB were investigated in snap-frozen tumor material, conventionally paraffin-embedded material, and tumors embedded in formol sucrose/gum sucrose/paraffin (FSGSP) by the new tissue processing technique of Bolton and Mesnard (1982), which preserves and enhances the antigenicity of tissues. The FSGSP processing offered a better immunocytochemical staining with MAB as compared to cryostat material, while the conventionally embedded paraffin sections of tumors did not stain at all. The binding of MAB revealed an affinity to both glial tumor cells and normal astrocytes. The techniques described are suitable for the identification of an astrocytic subpopulation within gliomas, and may improve the understaining of antigen expression in various stages of astrocytic dedifferentiation.

Animals↗
PubMed1986

Disseminated vasculomyelinopathy in the peripheral nervous system mediated by immune complexes (ICs). Immunohistochemical studies of sciatic nerves in chronic serum sickness (CHSS) in rabbits.

Histological examination of 20 sciatic nerves from rabbits with experimental chronic serum sickness (CHSS) revealed patchy vasculitis of the vasa nervorum of various intensity. The vessel lesions ranged from endothelial proliferation to vessel wall necrosis with fibrinoid degeneration and infiltration by lymphocytes, plasma cells, macrophages and, sporadically, by neutrophils. Perivascularly, there were oedema, chronic infiltrates or small haemorrhages. The myelinated fibres in close relation to the vascular system were focally depleted and features of perivascular demyelination were found. Teased fibres showed paranodal and segmental demyelination, axonal degeneration and, sporadically, remyelination. In all cases, immunofluorescent deposits of bovine serum albumin (BSA), IgG and C3 complement were found in and around some vasa nervorum. Other indirect evidence for immune complex (IC) deposition was provided by ultrastructural examination where vascular and endoneurial osmophilic deposits were found; in 4 cases with paracrystalline organization resembling cryoglobulin component. IC-mediated vasculitis led to blood-nerve barrier impairment and leakage of serum proteins into the endoneurial space. The morphological and immunohistochemical changes in this model which develop after a latency period of 2 or more weeks, strongly resemble those observed in human acquired inflammatory demyelinating polyradiculoneuropathies or in connective tissue diseases.

Animals↗
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↗