Demonstration for cold atmospheric pressure plasma jet operation and antibacterial action in microgravity.

Cold atmospheric pressure plasma (ionized gas) is an innovative medical tool for the treatment of infected wounds thanks to its potential to inactivate drug-resistant microorganisms and promote tissue regeneration and vascularization. The low power consumption, compactness, and versatility of Cold Atmospheric Pressure Plasma (CAPP) devices make them an ideal tool for risk mitigation associated with human spaceflights. This work presents results in microgravity on the operability of CAPP and its antimicrobial effect. The experiments carried out in parabolic flights make it possible to optimize the treatment conditions (i.e., the distance, the gas mixture) and to obtain the rapid inactivation (<15 s) of Escherichia coli samples. Interestingly, the inactivation efficiency of CAPP was higher during parabolic flights than under terrestrial conditions. Overall, these results encourage the further development of CAPP medical devices for its implementation during human spaceflights.

Sacrococcygeal chordomas: potential role of high LET therapy.

Chordomas are rare malignant neoplasms representing less than 3% of all primary bone tumors. They usually have a benign histological appearance and a slow growth rate. Their locoregional progression nearly always causes suffering and eventually death. Efforts to increase local control have included aggressive surgery, radiation therapy or combined approaches but locally free survival rates remain relatively low and have not exceeded 30% at 5 years. Sacrococcygeal chordomas, which represent approximately 50% of the localizations, have been investigated less frequently than those at the base of the skull or cervical region with primary or post-operative radiation therapy. The disappointing results with photon therapy in a multimodality approach and the good results reported by Schoenthaler with charged particles in the Lawrence Berkeley laboratory led us to propose fast neutron therapy in the management of inoperable or recurrent sacrococcygeal chordomas. Preliminary results obtained from only 12 patients indicate that high linear energy transfer (LET) therapy seems to be a good alternative for radical treatment of chordomas in the case of microscopic or macroscopic residual tumor.

Fast neutron therapy for inoperable or recurrent sacrococcygeal chordomas.

Between 1981 and 1994, 13 patients were referred to the Orleans neutrontherapy department with inoperable or recurrent pelvic chordomas. One patient who had already been irradiated refused the treatment, fearing complications. Among the 12 patients suitable for evaluation, ten had undergone one to five previous surgical operations. The time lapse between the last surgical operation and neutrontherapy was 13 months. Neutrons were used alone or as a boost depending on the tumor volume or treatment purpose. At four years, crude survival and local control probability (Kaplan-Meier) were 61 and 54% respectively. This small series suggests that fast neutrontherapy can provide a good alternative for the treatment of inoperable sacral chordomas.

[Changes in resistance of Pseudomonas aeruginosa to beta-lactams in a general intensive care unit over a three-year period. Role of piperacillin]. / Evolution de la résistance aux beta-lactamines chez Pseudomonas aeruginosa en réanimation polyvalente sur une période de trois ans. Rôle de la pipéracilline.

Nosocomial infections by Pseudomonas aeruginosa seen in a general intensive care unit from January 1987 through December 1989 were studied. Use of piperacillin, ticarcillin, cefsulodine, ceftazidime, and imipenem over the same period were recorded. Rate of infection by P. aeruginosa among the 1,844 patients admitted during the study period was 3.2%; 32% of all nosocomial infections during this period were due to P. aeruginosa. The proportion of P. aeruginosa strains exhibiting in vitro susceptibility to ticarcillin rose from 45.5% in 1987 to 59% in 1988 and 86% in 1989. Concomitantly, the proportion of P. aeruginosa strains simultaneously resistant to ticarcillin, piperacillin, cefsulodine and ceftazidime fell from 32% to 18.5% then 0%. A statistically significant correlation was found between the decrease in piperacillin use and the fall in penicillinase-producing ticarcillin-resistant strains of P. aeruginosa. Because piperacillin has undesirable effects on the intestinal flora and promotes the emergence of resistant strains of P. aeruginosa, the authors now use narrow spectrum antimicrobial agents as first line treatment of nocosomial infections.