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S Krajewski

Publications and source records attributed to S Krajewski.

193 records · Page 11Linked to original sources
PubMed1986

[Application of renal subcapsular assay to rat malignant brain tumor].

As a rapid screening method for testing chemotherapeutic agents against human tumor explants, renal subcapsular assay has been established by Bogden et al (1978). The authors investigated the effectiveness of the technique of Bogden for rat glioma. Preselected 1 mm3 fragments of viable tumor tissue of rat (CDF) were implanted under the renal capsule of normal immunocompetent rats. Then initial and final tumor sizes (formula; see text) were measured in situ with an oculometer inserted into a surgical microscope, and evaluated the changes of tumor sizes. The experiments were divided into three groups. The first group was that tumor pieces of rat (CDF) were implanted under the renal capsule of the syngenetic rats (CDF). Non-irradiated and preirradiated (400 rad) heterogenetic rats (Wistar) were used as the second and third groups. The explanted tumor pieces grew rapidly in the first group (syngenetic rats). On the other hand, poor growth of the second group (non-irradiated heterogenetic rats) was seen within 7 days after implantation, and rejected completely until 15 days after implantation. Explanted tumor pieces in the third group (pre-irradiated heterogenetic rats), however, grew enough big, though the change of tumor sizes was less than that of the first group. Histological examination was also performed. In the first and third group, proliferation of glioma cells was remarkable under the renal capsule, and neovascularization in the explanted tumor tissue was provided from the capsule, first, and then parenchym of the kidney. Even necrosis and hemorrhage were seen in the tumor tissue 15 days after implantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Necrotic changes of the spinal cord with immune-complex-mediated disseminated vasculitis in a case of atypical allergic encephalomyelitis.

A 42-year-old woman demonstrated recurrent, progressive neurological symptoms of peripheral and central nervous system damage of undefined infectious origin. Laboratory investigations showed abnormalities in the CSF and serum, suggesting subacute viral infection. Neuropathological examination revealed complete, widespread necrosis in the cervical and thoracic segments of the spinal cord with mononuclear and microglial infiltrations. There was pronounced thickening and fibrinoid necrosis of the vessel walls with mononuclear cuffs along the spinal cord. Dispersed, similar but less intensive inflammatory changes were present in the medulla oblongata, midbrain and basal ganglia. Surprisingly, there was diffuse demyelination with only slight glial and inflammatory reactions throughout the white matter of both hemispheres. The finding of coarse- and fine-grained deposits of IgG and C3 component of complement in the vessel walls of the spinal cord and vasa nervorum of cervical roots and peripheral spinal nerves, together with positive heterologous complement binding and the results of glycine-HC1 buffer elution, suggested immune-complex-mediated disseminated vasculomyelinopathy of the CNS and PNS. Consequent local ischemic changes and hypersensitivity phenomena led to frank necrosis of the cervical spinal cord and to extreme white matter demyelination in the brain. The case was diagnosed as allergic encephalomyelitis in which diffuse demyelination occurred coincidentally with spinal cord necrosis.

Adult↗
PubMed1983

Detection and quantitation of immune complexes by polyethylene glycol-laser nephelometer assay. I. Immunological study in chronic serum sickness in rabbits.

Polyethylene glycol (PEG)-laser nephelometer assay for the detection of circulating immune complexes (i.c.) has been developed. The method proved to be useful in the detection of i.c. in sera of rabbits with chronic serum sickness. I.c. were detected in 28 animal experimental sera and in samples with preformed immune complexes, but not in sera of 10 healthy rabbits and 5 rabbits prior to immunization. Laser nephelometer assay is a rapid, simple, quantitative screening test suited for clinical use as a first step in i.c. detection.

Animals↗
PubMedDate not supplied

Down-regulation of survivin by antisense oligonucleotides increases apoptosis, inhibits cytokinesis and anchorage-independent growth.

Survivin, a member of the inhibitor of apoptosis protein (IAP) family, is detected in most common human cancers but not in adjacent normal cells. Previous studies suggest that survivin associates with the mitotic spindle and directly inhibits caspase activity. To further investigate the function of survivin, we used a survivin antisense (AS) oligonucleotide to downregulate survivin expression in normal and cancer cells. We found that inhibition of survivin expression increased apoptosis and polyploidy while decreasing colony formation in soft agar. Immunohistochemistry showed that cells without survivin can initiate the cleavage furrow and contractile ring, but cannot complete cytokinesis, thus resulting in multinucleated cells. These findings indicate that survivin plays important roles in a late stage of cytokinesis, as well as in apoptosis.

Apoptosis↗
PubMedDate not supplied

Chronic ureteral obstruction in the rat suppresses renal tubular Bcl-2 and stimulates apoptosis.

Unilateral ureteral obstruction (UUO) results in widespread tubular apoptosis in obstructed kidneys of both adults and neonates. The oncoprotein bcl-2 inhibits many forms of apoptosis, whereas the related protein bax promotes apoptosis. To evaluate the interaction of bcl-2, bax, and apoptosis in the renal response to UUO, adult and neonatal rats were subjected to UUO or sham operation, and kidneys were harvested 14 days later. Apoptotic cells were identified by the Tunel technique, and the distribution of bcl-2 and bax was determined by immunochemistry. In both adults and neonates, tubular and interstitial apoptosis was present in the obstructed kidney, but not in intact kidneys. In both adults and neonates, there was diffuse tubular bcl-2 and bax staining of sham-operated and intact kidneys. While bcl-2 was increased in scattered nonapoptotic tubules of the obstructed kidney, there was minimal staining of dilated apoptotic tubules. These results are consistent with the premise that bcl-2 normally suppresses renal tubular apoptosis. The distribution of bax staining in tubules of the obstructed kidney overlapped that of bcl-2. We conclude that chronic UUO inhibits bcl-2 expression in selected tubules of the obstructed kidney which contributes to activation of apoptosis and progressive renal damage in either neonatal or adult kidneys. Dysregulation of apoptosis may be a response to renal injury similar to that underlying the development of cystic kidney disease or renal dysplasia.

Animals↗