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Biomedical subjects

J Kowalski

Publications and source records attributed to J Kowalski.

At least 145 records · Page 8Linked to original sources
PubMed1988

The disc angiogenesis system.

A new system for the study of angiogenesis in vivo has been devised. It consists of a small disc of polyvinyl alcohol foam, covered on both flat sides by Millipore filters, leaving only the edge as the area for cell penetration into the disc. Angiogenic agonists or antagonists, as well as other substances to be studied, are placed in the center of the disc. The slow release of these substances is maintained by a film of ethylene-vinyl acetate co-polymer, or by the use of agarose. The disc is implanted subcutaneously in the host animal through a distant skin incision. In mice, the optimal times for examination of the discs are 7 to 12 days after implantation for discs containing angiogenic stimulants and 12 to 20 days for those without stimulants. After a period of growth is completed, the disc is removed, fixed, and embedded in paraffin or methacrylate. Medial plane sections, stained by a variety of methods, are used to observe and measure the growth of vessels and stroma into the disc. Whether stimulated or not, this growth is centripetal and can be easily quantitated by simple morphometric technics. This system has already been used in mice, to study the proliferation of vessels and fibroblasts into discs devoid of, or containing angiogenic stimulants (epidermal growth factor, acidic fibroblastic growth factor). We have also utilized the discs to demonstrate the inhibition of vessel growth by hyperthermia. Examples of these applications are presented. The disc angiogenesis system is easy to prepare, inexpensive, and well tolerated, at least by mice. Its simplicity and reproducibility make it suitable for a wide range of applications beyond those described here.

Angiogenesis Inducing Agents↗
PubMed1987

Detection of a new Msp I restriction fragment length polymorphism in the apolipoprotein A-I gene.

We report the existence of a Msp I restriction fragment length polymorphism in the first intron of the apolipoprotein A-I gene that is different from the one described by Seilhamer et al. (DNA 3, 309 (1984)). Size comparison of the newly discovered Msp I fragment with a restriction map of the apolipoprotein A-I gene revealed that most likely the cutting site at the 5'-end of the normally seen 673 bp fragment is lost giving rise to the observed 719 bp Msp I fragment. Based on analyses of 136 DNAs of healthy and non-related caucasians the allelic frequency was determined to be 0.06. The observed Msp I genotype frequencies are in Hardy-Weinberg equilibrium.

Apolipoprotein A-I↗
PubMed1986

[Obstructive airway diseases and cigarette smoking].

The rate of uncomplicated bronchitis, obstructive bronchitis, obstructive emphysematous bronchitis, airways obstruction without bronchitis, emphysema, obstructive emphysema, and emphysematous bronchitis was determined in 300 patients. Assessment of smoking habits showed a ratio of non-smokers to smokers (smokers and ex-smokers) in uncomplicated bronchitis of 1 : 2, and in the various forms of obstructive lung disease of 1 : 1.41. Smoking, therefore, has a causative role in every third case of airways obstruction. The results support the view that smoking promotes the appearance of obstructive airways disease but that other additional or single factors such as infection and allergies probably have a more decisive role. Lung-function parameters in smokers and non-smokers, for the various forms of obstructive airways disease, are not affected differently.

Adult↗
PubMed1985

Vectors for the direct selection of cDNA clones corresponding to mammalian cell mRNA of low abundance.

We have constructed two cDNA cloning vectors which (1) carry the intergenic region of phage f1 and (2) permit efficient cloning (by the Okayama-Berg procedure) of full-length copies of mammalian mRNA in either orientation. Infection of cells harboring these vectors with f1 phage results in the encapsidation of single-stranded (ss) plasmid DNA carrying either the sense or the anti-sense sequence of the cDNA inserts. The complementary nature of the cDNA inserts in two such cDNA libraries facilitates preparative hybridization procedures. These vectors have general applicability to any eukaryotic system where changes in the abundance of mRNA transcripts are to be measured and the corresponding cDNA clones isolated.

Cloning, Molecular↗
PubMed1985

A unique family of endothelial cell polypeptide mitogens: the antigenic and receptor cross-reactivity of bovine endothelial cell growth factor, brain-derived acidic fibroblast growth factor, and eye-derived growth factor-II.

Bovine brain, hypothalamus, pituitary, and retina contain potent anionic polypeptide mitogens for endothelial cells. Immunological assays using murine monoclonal antibodies against bovine endothelial cell growth factor (ECGF) and radioreceptor assays using [125I]ECGF were performed to determine the cross-reactivity of ECGF with bovine acidic pI brain-derived fibroblast growth factor (acidic FGF) and bovine eye-derived growth factor-II [EDGF-II). We observed that acidic FGF and EDGF-II are recognized by anti-ECGF monoclonal antibodies and compete with [125I] ECGF for receptor occupancy. Furthermore, the biological activity of ECGF, acidic FGF, and EDGF-II is potentiated by the glycosaminoglycan, heparin. These results argue that ECGF, acidic FGF, and EDGF-II belong to a common family of polypeptide growth factors.

Animals↗
PubMed1984

Enkephalin content in rat striatum during prolonged treatment with fluphenazine.

Male Wistar rats were injected with fluphenazine /FLU/ i.p. in doses of 1 or 5 mg/kg for twelve months. Striatal met- and leu-enkephalin contents were determined after 1, 3, 6, 9 and 12 months of treatment, and one week after the drug withdrawal following a 12-month treatment, Enkephalin levels were significantly increased with slight fluctuations in some months and returned to normal one week after the last neuroleptic dose following a 12-month administration. Apomorphine, but not naloxone, prevented elevation of enkephalin levels after a one month FLU administration. Our findings confirm previous observations that prolonged disturbances in functions of the dopaminergic mechanism result in specific disturbances in the endogenous opioid peptide content, release and biosynthesis, and demonstrate that enkephalins are one of the factors with take part in the mechanism of neuroleptic action during a long-term treatment.

Animals↗
PubMed1983

The effect of a single temazepam administration on enkephalin content in the striatum and hypothalamus of the rat.

Temazepam, a benzodiazepine ataractic, given in a dose of 10 mg/kg ip to rats depressed the striatal contents of met-enkephalin and leu-enkephalin by 60 and 35% resp. The changes were most pronounced 30 min after the treatment. In the hypothalamus temazepam produced a short-lasting elevation of met-enkephalin content (225% of the control value). The pattern of changes produced by temazepam resembles that described for diazepam. This suggests that enkephalins participate in the pharmacological effects of benzodiazepine ataractics on the central nervous system.

Animals↗
PubMed1982

Adenovirus DNA replication in vivo: properties of short DNA molecules extracted from infected cells.

Adenovirus type 5 (Ad5) DNA replicating in intact HeLa cells was pulse-labeled with [3H]thymidine extracted by the procedure of Hirt and analyzed on neutral sucrose gradients. In addition to viral replicative forms (over 33 kb), slowly sedimenting species of DNA (0.05-3 kb) was observed. Hybridization analysis showed that this DNA contained about 30% Ad5 DNA sequences. Analysis of the sensitivity of this DNA to the 5' OH-specific spleen exonuclease after alkali or RNAase treatment revealed that about 80% of these molecules contained ribonucleotides. DNA in this fraction was labeled at the 5' end with 32P and hybridized together with control 3H-labeled Ad5 DNA to Hpa I restriction fragments immobilized on nitrocellulose paper. Many of these small molecules were located near the termini. Alkali treatment prior to hybridization decreased the 32P/3H ratio throughout the genome. This suggests that some of these Ad5 molecules possess ribonucleotides and therefore may be intermediates in discontinuous DNA replication. Longer molecules (over 0.5 kb) were found sedimenting with viral replicative forms and mature DNA. The Ad5 molecules in this fraction showed no evidence of alkali-labile termini.

Adenoviridae↗
PubMed1982

An outbreak of mycoplasma pneumoniae respiratory illness in a semi-closed religious commune.

Of approximately 200 members of a religious commune, 37 came to the emergency department of Cook County Hospital for primary medical care of respiratory illness. Of the 37, 31 were seen during a two-week period, indicating a rapid spread of disease. The major symptoms were cough, fever, coryza, and sore throat. Infiltrates were detected in 38%. Paired sera from four of nine patients showed a significant rise to Mycoplasma pneumoniae. Of 24 sera collected at the time of the first visit, 33% had a titer to the agent, of 64 or greater--presumptive evidence of Mycoplasma infection. Therefore, M pneumoniae was implicated as the causative agent in this outbreak of respiratory illness in a semi-closed community.

Adolescent↗