Biomedical subjects

B Kus

Publications and source records attributed to B Kus.

5 recordsLinked to original sources

PubMed1999

Neuroprotective effects of acetylsalicylic acid in an animal model of focal brain ischemia.

Recent studies have shown neuroprotective effects of acetylsalicylic acid (ASA) in cell cultures and hippocampal slices. The present study demonstrates similar effects in a whole-animal modal of focal ischemic stroke. Focal cortical ischemia was produced in Wistar rats by ligation of the common carotid and middle cerebral arteries. Subjects were sacrificed 8 days after ligation, and infarct volume was assessed via automated densitometry. Significant reductions in infarct volume were seen with i.p. ASA doses of 15 mg/kg and above. Reductions occurred when ASA was injected 2 h or 30 min before ligation, but not when it was injected 8 or 24 h before, or 30 min after ligation.

Animals↗

PubMed1996

Searching for new TNF-alpha analogs having potential application in cancer therapy.

Two new TNF-alpha analogs were prepared and tested for their anti-tumor activity on fibrosarcoma SA-1 tumor model in vivo. In analog LK-801 two histidines (His107His108) were introduced into the surface loop thus enabling efficient purification by metal-affinity chromatography. This analog showed less side effects and can serve as a lead compound to look for other useful mutations. Another analog LK-802 was designed by introduction of additional pair of mutations (Cys95Cys148) into LK-801 in order to prepare disulfide linked TNF trimers. Cytotoxicity on mouse cell line L929 was comparable to TNF-alpha, but effect on tumor growth was quite reduced. Pharmacokinetic study revealed that serum levels of LK-802 were quite low in comparison to native TNF-alpha. This at least partially explains why anti-tumor activity of LK-802 is reduced and also illustrates the problems in designing the analogs with desired in vivo biological properties.

Animals↗

PubMed1994

Purification of human tumour necrosis factor by membrane chromatography.

The recombinant human tumour necrosis factor alpha from an extract of Escherichia coli was enriched to homogeneity according to specific activity and sodium dodecyl sulphate-polyacrylamide gel electrophoresis by purification using anion-exchange HPLC and hydrophobic interaction HPLC. Parallel experiments with the same separation methods, but carried out with membrane chromatography on compact discs, gave similar results in terms of yield and purity of the product. The active form of the protein is a trimer. The second isolation step, hydrophobic interaction chromatography, causes dissociation of the trimer into monomers and a partial loss of the biological activity of the protein. The phenomenon occurs on both the column and the disc. This in turn indicates strongly that the dissociation of the protein is a consequence of interaction between the samples and the hydrophobic ligand, and is not caused by non-specific interaction with the matrix.

Blotting, Western↗

PubMed1993

Modification of TNF-alpha pharmacokinetics in SA-1 tumor-bearing mice.

Fibrosarcoma-SA-I-tumor-bearing mice were treated s.c. in the vicinity of tumors (peri-tumorally) or intravenously, with recombinant human TNF-alpha lacking 1 to 3 amino acids from N-terminal part (TNF-alpha Nv3). Tumor growth delay, observed after both routes of TNF-alpha Nv3 application, was statistically significant, though a better anti-tumor effect was achieved after peri-tumoral application. TNF-alpha Nv3 serum levels were determined in these animals and compared with TNF-alpha Nv3 serum levels in healthy animals, which were treated with TNF-alpha Nv3 either s.c. or i.v. The peak serum levels of TNF-alpha Nv3 applied peri-tumorally/s.c. were significantly higher in tumor-bearing than in healthy mice, whereas smaller differences in peak serum levels were found after i.v. application, which might correlate with anti-tumor activity. Whatever the route of application, TNF-alpha Nv3 elimination from the serum of tumor-bearing mice was slower than that in healthy animals. Also, comparison of TNF-alpha Nv3 pharmacokinetic parameters for tumor-free and sarcoma- or melanoma-bearing mice has demonstrated that the pharmacokinetics of TNF-alpha Nv3 are modified in tumor-bearing animals.

Animals↗

PubMed1993

[Auricular leiomyoma].

An auricular leiomyoma is reported. This neoplasm is extremely rare in the head and neck region. The clinical and histopathological features are discussed.

Aged↗