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Biomedical subjects

L Kaczmarek

Publications and source records attributed to L Kaczmarek.

At least 91 records · Page 5Linked to original sources
PubMed1992

Peer-mediated intervention: attending to, commenting on, and acknowledging the behavior of preschoolers with autism.

This study investigated the effects of a peer-mediated intervention on the social interaction of five triads comprised of preschoolers with autism and their typical peers. Strategies thought to facilitate interaction were selected based on analyses of a descriptive data base. Peers were taught to attend to, comment on, and acknowledge the behavior of their classmates with disabilities. These are behaviors preschoolers typically exhibit frequently, but that do not obligate responses to the same extent as questions and requests do. The ABCB reversal designs revealed that improved rates of social interaction during play were clearly associated with the peer intervention for 4 of the 5 children with autism. This intervention offers an alternative peer-intervention package for increasing interaction between children with and without disabilities.

Attention↗
PubMed1991

Dextrorphan blocks long- but not short-term memory in a passive avoidance task in rats.

In the present study a mixed sigma and PCP (phencyclidine) site ligand, dextrorphan (22 mg/kg), blocked long- but not short-term memory in a passive avoidance task. This effect was not accompanied by any behavioral alterations that could interfere with passive avoidance performance. The action of dextrorphan was shared by a selective NMDA (N-methyl-D-aspartate) receptor antagonist, MK-801 (5-methyl-10,11-dihydro-5H-dibenzocyclohepten-5,10-imine maleate, 0.1 mg/kg). The results suggest that dextrorphan affects long-term memory, probably via blockade of NMDA receptors.

Animals↗
PubMed1991

c-fos protooncogene expression in rat hippocampus and entorhinal cortex following tetanic stimulation of the perforant path.

The elevated expression of the c-fos protooncogene has been proposed to be a marker of cell activation leading to a long term cellular response. In this communication we compared the c-fos mRNA accumulation in the hippocampus (i.e. postsynaptic cells) and entorhinal cortex (i.e. presynaptic cells) following high (tetanic) and low frequency electrical stimulation of the perforant path. Using Northern blot analysis we have found that high frequency stimulation elevates c-fos expression in both hippocampus and entorhinal cortex, and the increase of c-fos mRNA levels in the entorhinal cortex is less pronounced, but longer lasting, than in the hippocampus. Slight increase of c-fos mRNA levels has been also observed in low frequency treated animals in the entorhinal cortex, but not in the hippocampus. These findings raise the question about differences in mechanisms involved in c-fos activation in both parts of the brain after stimulation which evokes long term potentiation (LTP) of synaptic efficacy.

Animals↗
PubMed1990

Accumulation of ornithine decarboxylase mRNA accompanies activation of human and mouse monocytes/macrophages.

Accumulation of ornithine decarboxylase (ODC) mRNA was investigated in human monocytes and mouse peritoneal macrophages. Treatment of both populations of mononuclear phagocytes with bacterial lipopolysaccharide induced a marked and rapid increase in the accumulation of the ODC gene transcript. A similar phenomenon, albeit less pronounced, was also observed following treatment of human monocytes with human recombinant interferon-gamma. These results suggest a role for ODC, and therefore polyamines, in the regulation of mononuclear phagocyte functions.

Animals↗
PubMed1990

Glial fibrillary acidic protein messenger RNA and glutamine synthetase activity after nervous system injury.

The level of the mRNA for glial fibrillary acidic protein (GFAP), the major protein of the intermediate filaments of astroglial cells, and the activity of glutamine synthetase (GS), an enzyme selectively localized in astrocytes, were measured at different times after a unilateral mechanical lesion in the rat cerebral cortex. A rapid and early increase (6 hours post-lesion) in GFAP mRNA was observed; GFAP mRNA level reached a peak at 1-3 days and then decreased. Moreover, an astrocytic activation in cortical zones far from the injury site and in the contralateral hemisphere was detected. No change of GS activity was observed in the same model of brain injury, showing that this astroglial marker is not modified during the reactive gliosis obtained with this experimental model. GFAP mRNA has also been detected in the rat sciatic nerve; however, its level was not modified after nerve transection, suggesting a different regulation of GFAP expression in the peripheral nervous system.

Animals↗
PubMed1990

The regulation of G0-S transition in mouse T lymphocytes by polyamines.

While the role of polyamines in DNA synthesis during the S phase of the cell cycle has been repeatedly postulated, recent studies point also to polyamine involvement in the early phase of the G0-S transition. In order to determine polyamine-dependent steps in the cell cycle we have studied the effects of inhibitors of polyamine biosynthesis and exogenous polyamines on the proliferation of T lymphocytes as well as on the expression of some growth-regulated genes. The ability of Con A-stimulated mouse T lymphocytes to enter DNA synthesis was markedly inhibited by methylglyoxal bis(guanylhydrazone) in a dose-dependent manner. This inhibitory effect was stronger in the presence of fetal calf serum containing a high level of activities of polyamine oxidases than in the presence of horse serum. Putrescine and spermine added to T splenocyte culture instead of mitogen-Con A stimulated [3H]thymidine incorporation with kinetics similar to that observed with Con A. The growth-stimulating effects of polyamines were concentration-dependent. Polyamines at optimal growth-stimulating concentrations (10 microM spermine and 80 microM putrescine) induced the expression of genes encoding the cytoskeletal proteins beta-actin, vimentin, and alpha-tubulin to an extent and with kinetics similar to those of Con A. The results presented herein suggest that polyamines are capable of stimulating the transition of G0 cells to the S phase and that this effect may be mediated by their influence on the gene expression.

Animals↗
PubMed1990

Accumulation of c-fos mRNA in rat hippocampus during acquisition of a brightness discrimination.

Training rats to attain a foot-shock-motivated brightness discrimination in a Y-maze results in an early and transient increase of hippocampal c-fos mRNA levels. Maximal accumulation was observed immediately after training, returning to basal levels during the following 2 h. A similar increase was obtained when rats were subjected to a pseudotraining with an equal number of runs, but with random pairing of the choice of bright and dark alleys with foot shock. It is suggested that induction of hippocampal c-fos mRNA expression is a necessary, but not sufficient, prerequisite for the formation of long-term memory trace. This early gene expression seems rather to correspond to an initial stage induced by complex stimulus presentation of both the training and the pseudotraining procedure. The subsequent late synthesis or processing of target proteins finally contributing to the formation of a permanent trace requires the action of further convergent signals to principal cells, probably mediating reward or emotional influences.

Animals↗
PubMed1990

c-fos protooncogene expression and neuronal plasticity.

Protooncogene c-fos is a nuclear protein repeatedly implicated in regulation of gene expression. The elevated expression of the c-fos protooncogene in neurons has been observed in many instances of neuronal activation both in vitro and in vivo. The increase of c-fos mRNA and/or protein levels has been shown to result from the action of neurotransmitters on membrane receptors and seems to be induced by physiological stimuli. We suggest that the elevated expression of c-fos protooncogene couples stimulation of the neurons by extracellular ligands with intracellular long term effector responses including long lasting memory formation.

Animals↗
PubMed1989

Tissue specific distribution of calcyclin--10.5 kDa Ca2+-binding protein.

Expression of calcyclin in different cell lines and mouse tissues was determined with polyclonal antibodies raised against calcyclin from Ehrlich ascites tumour (EAT) cells. The protein was detected in mouse skeletal and cardiac muscle, in lung, kidney and spleen, and was especially enriched in mouse smooth muscle as well as in rat fibroblasts. No positive immunological reaction was detected in mouse brain, liver and intestine and some tumourigenic cell lines. The level of calcyclin mRNA found in different cells and tissues corresponded well to the calcyclin level estimated by immunoblotting. The calcyclin-like protein was purified from mouse stomach and appeared to be very similar to the EAT protein.

Animals↗
PubMed1989

Levels and size complexity of DNA polymerase beta mRNA in rat regenerating liver and other organs.

A cDNA probe encoding DNA polymerase beta (beta-pol) was used to study the level and size complexity of beta-pol mRNA in regenerating rat liver and other rat tissues. An almost 2-fold increase in beta-pol mRNA was observed 18-24 h after partial hepatectomy. In most adult rat tissues (liver, heart, kidney, stomach, spleen, thymus, lung and brain) the abundance of beta-pol mRNA was low. In contrast, young brain and testes exhibited beta-pol mRNA levels 5- and 15-times higher, respectively. The observed changes in the level of beta-pol mRNA in regenerating rat liver and in developing brain are correlated with reported changes in DNA polymerase beta activity. Four different (4.0, 2.5, 2.2, 1.4 kb) transcripts hybridizing to beta-pol probe were found in all tissues examined. The 4.0 kb transcript was dominant for young and adult brain, whereas the 1.4 kb transcript was dominant for testes. The significance of these transcripts is discussed.

Animals↗
PubMed1989

Induction of protooncogene fos by extracellular signals in primary glial cell cultures.

In the present study various extracellular factors, acting through different second messenger systems, were examined for their capacity to increase the level of c-fos mRNA in primary glial cell cultures. In particular EGF, 12-O-tetradecanoylphorbol 13-acetate, the beta-adrenergic agonist isoproterenol, and the glutamate agonists, ibotenic and quisqualic acid, were studied. All the extracellular stimuli tested induced a rapid and transient increase in c-fos mRNA level in glial cell cultures regardless of the signal transduction pathway and the final effect on cell proliferation.

Animals↗
PubMed1989

Molecular biology of cell activation.

This article summarizes common features of activation of different types of cells along different physiological lines such as proliferation, differentiation, and execution of function of terminally differentiated cells. The common basis of many of these phenomena includes (i) first messengers (growth factors, cytokines, neurotransmitters, etc.) acting on membrane receptors, (ii) second messengers (cAMP, IP3, DAG, Ca2+) spreading an activating signal inside the cell, and (iii) elevated expression of some genes (c-fos, c-myc, ornithine decarboxylase). The role of the genetic correlate in cell activation is emphasized, and it is concluded that the aforementioned genes (their protein products) should be called third messengers, whose function is mediation of long-term phenotypic changes.

Animals↗
PubMed1989

Thymic non-lymphoid cells cultured for transplantation purposes. Immunostimulatory effect on ataxia telangiectasia peripheral blood mononuclear cells.

The analysis of various methods of thymic non-lymphoid cells (TNLC) culture in vitro was performed. The TNLC obtained in culture of small thymic fragments in Eagle's minimal essential medium with 30% of fetal calf serum have been found to be biologically active as indicated by their ability to enhance proliferative activity and Il-2 production of peripheral blood mononuclear cells derived from ataxia telangiectasia patients.

Ataxia↗
PubMed1988

Proto-oncogene c-fos induction in rat hippocampus.

The apparently non-specific accumulation of c-fos proto-oncogene mRNA was found in rat hippocampus as a result of injection of either glutamate, noradrenaline, or physiological saline. There was no c-fos gene induction following an electroconvulsive shock.

Animals↗
PubMed1988

Postirradiation recovery of haemopoiesis in Steel mutant mice.

The recovery of haemopoiesis in Steel mutant mice following 1 Gy sublethal irradiation is described. Steel homozygotes (S1/S1) did not display the abortive phase of erythropoietic recovery while the secondary phase of erythropoietic recovery was more pronounced in S1/S1 than in control (+/+) animals. On the contrary, the neutrophilopoietic recovery in S1/S1 mice was defective only during the secondary phase of recovery. Steel heterozygotes (S1/+) manifested similar, albeit less pronounced, defects. In the course of studies of recovery of eosioniphils it was observed that neither wild-type nor mutant animals expressed the abortive rise. Moreover, the kinetics of recovery of eosinophils was essentially different from both erythropoietic and neutrophilopoietic recovery, and the preirradiation level was reached in both normal and mutant animals on day 60 postirradiation as opposed to 24 and 35 days for erythropoiesis and neutrophils respectively.

Animals↗