Biomedical subjects

N Tremblay

Publications and source records attributed to N Tremblay.

54 records · Page 3Linked to original sources

PubMed1987

Acetylcholine permits long-term enhancement of neuronal responsiveness in cat primary somatosensory cortex.

Acetylcholine (ACh) was administered iontophoretically to single neurons in cat somatosensory cortex. Using extracellular recording techniques, neuronal responsiveness was determined at regular intervals from the number of action potentials produced either by iontophoretically applied glutamate or by tactile stimulation of the cutaneous receptive field. The responses were altered in only 21% (13/61) of the neurons following the application of ACh alone. In contrast, 75% (66/88) of the neurons displayed altered responses during administration of ACh simultaneously with either iontophoretically administered glutamate or with tactile stimulation of the receptive field. Forty-seven percent (29/62) of the responses potentiated in the presence of ACh remained enhanced for periods lasting from 8 min to over 1 h. The responsiveness of cortical neurons to afferent inputs changes during the reorganization of somatotopic maps that occurs after deafferentation, and perhaps during some forms of learning. As ACh has been implicated in some of these processes, it may be that the changes in responsiveness observed here following iontophoretically applied ACh are similar to those which facilitate the acquisition of neuronal responses to altered or novel afferent inputs.

Acetylcholine↗

PubMed1983

A double-masked comparison of ocular decongestants as therapy for allergic conjunctivitis.

A prospective, randomized, double-masked study of three commercially available ocular decongestant products was conducted to compare their relative efficacies in the treatment of allergic conjunctivitis. All three products contained a vasoconstrictor (naphazoline hydrochloride) and an antihistamine (antazoline phosphate or pheniramine maleate) in varying concentrations. Eighty-nine (89) patients presenting the ocular signs and symptoms of allergic conjunctivitis were enrolled and randomly distributed among the three treatment groups. Patients were evaluated for three ocular signs (lid swelling, bulbar conjunctival inflammation and palpebral conjunctival inflammation) and three ocular symptoms (itching, tearing and discomfort). An overall follow-up impression of treatment results was also recorded. The treatment period lasted one week. The three preparations were found to vary greatly in patient comfort and acceptability but were not different in their ability to ameliorate the itching, tearing, redness, edema and discomfort when dosed topically for the relief of allergic conjunctivitis.

Antazoline↗

PubMed1967

[Summer school of the Canadian Association of Medical Students and Interns--Haiti].

Six Canadian medical students record their experience at a summer school of tropical medicine in Haiti, sponsored by the Canadian Association of Medical Students and Internes. The social, economic and medical background is described, including "Voodoo" practices, language and Haitian art. Attention is directed to the occurrence of umbilical tetanus, diarrhea and malnutrition. From even a brief stay in a country such as Haiti one comes to appreciate that a public health program in an underdeveloped nation is not strictly a medical undertaking but must be seen in its social and economic contexts.

Adult↗

PubMedDate not supplied

Production of bioengineered cancer tissue constructs in vitro: epithelium-mesenchyme heterotypic interactions.

A few models have been established to study cancer cells in vitro. However, the cellular interactions have rarely been studied specifically using bioengineered cancer constructs combining human carcinoma cells and tumor-associated fibroblasts. We developed an in vitro model of tridimensional bioengineered cancer tissue constructs (bCTC) by seeding mammary epithelial cancer cells or normal keratinocytes over a mesenchymal layer containing tumor-derived fibroblastic cells or normal skin fibroblasts. After the introduction of epithelial cells, each construct was cultured for another 10 d. Histologic analyses showed that carcinoma cell lines could invade the subjacent mesenchymal layer and that the capacity to migrate was related to the invasive potential of cancer cells and the type of fibroblasts used, while noninvasive populations did not. Of the tested epithelial cells, MDA-MB-231 and, to a lesser degree, HDQ-P1 cell lines were invasive, and the invasion was deeper into the mesenchymal component containing tumor-derived fibroblasts. However, with normal skin fibroblasts, the mesenchymal layer was degraded twice faster than with tumor-derived fibroblastic cells. MDA-MB-231 cells and normal keratinocytes induced the highest level of gelatinase B, and the level was lowest with the MCF-7 cell line. The activated form of gelatinase B was, however, induced to the highest levels in the keratinocyte-seeded bCTC containing tumor-derived but not normal fibroblasts. MDA-MB-231 was the only epithelial cancer cell line whose activity of gelatinase A was reduced when cocultured with tumor-derived fibroblasts but not under normal fibroblast stimulation. Finally, a 50/48-kDa gelatinase band has been observed in bCTCs with noninvasive epithelial cells only. Our study demonstrates the selective secretion of gelatinases according to the phenotype of the cells seeded in the various bCTCs.

Breast↗

PubMedDate not supplied