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Biomedical subjects

M Oppenheim

Publications and source records attributed to M Oppenheim.

13 recordsLinked to original sources
PubMed2001

Electrostatic mode excitation in electron holes due to wave bounce resonances.

A kinetic theory of resonant interaction between electrostatic waves and the bounce motion of electrostatically trapped electrons is developed. Precise criteria are derived for the stability of electrostatic potential structures which trap electrons in a highly magnetized plasma. The theory explains the energy transfer from electron phase space holes to waves observed in simulations. It may also account for the destabilization of electrostatic waves propagating obliquely to the geomagnetic field and some characteristics of the holes as observed in the auroral ionosphere.

Journal Article↗
PubMed1996

Inhibition of nitric oxide synthesis does not improve interleukin-2-mediated antitumor effects in vivo.

Nitric oxide (NO) decreases cytotoxicity and proliferation of cytotoxic lymphocytes (CTLs) in vitro. Both can be prevented by inhibitors of the NO synthase (NOS). To elucidate whether inhibition of the IL-2-induced NOS could boost efficacy of IL-2-stimulated CTLs in vivo, we assessed lung metastases in mice injected with IL-2, the NOS inhibitor aminoguanidine (AG), their combination and the diluent. No improvement was observed for IL-2 + AG compared to IL-2 while NO production was normalized. Since NO causes one of the two major side effects of IL-2 treatment, hypotension, we further studied whether capillary leak could be attributed to NO, too. While IL-2-inducible NO was reduced to control levels by AG, pulmonary edema was unaffected. Thus a decrease in NO does not improve antitumor effects of IL-2-stimulated CTLs nor does it attenuate IL-2-associated capillary leak.

Animals↗
PubMed1995

Addition of interleukin 12 to low dose interleukin 2 treatment improves antitumor efficacy in vivo.

Interleukin 12 (IL-12) enhances lysis mediated by NK- and lymphokine activated killer (LAK) cells. It also causes proliferation of IL-2 stimulated T and NK cells in vitro. For these IL-2 complementing properties murine pulmonary metastases of a coloncarcinoma line were treated with IL-12 and IL-2 or with the individual agents. Results were compared to sham treated controls. IL-2 alone mediated significant tumor reduction but provoked pulmonary edema and concomittand toxicity, graded in three steps. IL-12 combined with an IL-2 dose reduced by 81% still resulted in significant antitumoral activity. Toxicity, however, was not discernable from sham treated controls. IL-12 thus appears as an attractive cytokine for combination with IL-2 in antitumor therapy. Particularly treatment of tumors, like gastrointestinal tract cancers, so far mainly resistant to cell mediated antitumor therapy, might profit from this approach.

Animals↗
PubMed1980

Healers.

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Diagnosis↗
PubMed1977

Clinical comparison of sealant and bonding systems in the restoration of fractured anterior teeth.

This study compared the clinical performance of the ultraviolet light-initiated fissure sealant and composite system (Nuva-Seal/Nuva-Fil) with a chemically activated system (Adaptic Bonding Agent/Adaptic). A total of 63 fractured permanent anterior teeth involving only enamel and dentin were restored. All teeth were isolated with rubber dams, and the acid etch technique was used. The degree of success was determined from an assessment of retention, marginal integrity, marginal staining, and color change. The restorations were evaluated at 3, 6, 12, 18, and 24 months postoperatively. Of the restorations, 93% were retained in both groups of patients after two years. Varying degrees of marginal problems (lack of marginal integrity or marginal staining) were directly attributable to the extension of the bonding medium and the composite in relation to the conditioned enamel and to each other. Repolishing of the margins should be considered at the time of the recall appointments to improve the quality of restoration.

Adolescent↗