ABSTRACT. To evaluate the response of the small intesAbbreviations tinal mucosa to Saccharomyces boulardii (S.b.), a yeast widely used in some countries as an adjuvant drug with S-b., Saccharomyces boulardii oral antimicrobial therapy, seven healthy adult volunteers BBM, brush border membrane were treated with high dbses of lyophilized S.b. (250 mg four times per day) for 2 wk. A peroral jejunal suction biopsy was performed on days 0 and 1 5 of the study. Compared to the initial biopsy, histological examination of the posttrial biopsy revealed no morphological alteration nor change in villus height or crypt depth. After treatment, the specific activity (per U protein) of sucrase, lactase, and maltase was, respectively, increased by 82% ( p < 0.05) 77% (p < 0.05), and 75% ( p < 0.05) over the basal activity of the enzymes measured on day 0, whereas mucosal protein content remained unchanged. Similar findings were found in the jejunum of adult rats treated for 5 days with either viable or killed S.b. cells. The changes in total enzyme activity (per jejunal segment) paralleled the changes in specific enzyme activity. I n vitro assays on freshly prepared suspensions of S.b. (6.0 x 10' viable cells/ ml) evidenced a high activity for sucrase (mean 2 SE: 8 364 + 1280 U . g . protein-') but no maltase, neutral lactase, acid P-galactosidase, or aminopeptidase activity. To determine whether treatment with S.b. could influence the incorporation rate of neutral lactase into the brush border membrane, 14-day-old sucklings treated either with saline or with S.b. were given intraperitoneally a dose of 20 pCi D-[ll'C] glucosamine 3 hours before sacrifice. Neutral lactase was isolated on SDS-PAGE of purified BBM. The amount of lactase protein eluted from the gel slices was similar in treated rats (mean + SE: 0.026 + 0.003) and in controls (0.021 -C 0.005 mg protein/ml). Expressed per millieram of brush border membrane lactase protein, there was no significant difference in the incorporation rate of labelled glucosamine between treated rats (mean 2 SE: 8 167 + 1 622 dpm.mg protein-') and controls (9 602 + 1 803 dpm.mg protein-'). In conclusion, short-term oral treatment of human volunteers and rats with S.b. is associated with a marked increase in the activity of disaccharidases without morphological alteration of the intestinal mucosa. Our findings do not suggest an effect of S.b. on the incorporation rate of enzymes into the brush border membrane. (Pediatr Res

to elucidate the planet's past climate, water activity, and habitability.Science is MER's primary driver, so making best use of the scientific instruments, within the available resources, is a crucial aspect of the mission. To address this criticality, the MER project team selected MAPGEN (Mixed Initiative Activity Plan Generator) as an activity-planning tool.MAPGEN combines two existing systems, each with a strong heritage: the APGEN activity-planning tool 1 from the Jet Propulsion Laboratory and the Europa planning and scheduling system 2 from NASA Ames Research Center. This article discusses the issues arising from combining these tools in this mission's context. Combining systemsIn a most exciting development, two NASA roversnamed Spirit and Opportunity-were slated to arrive at the Red Planet in January, at two scientifically distinct sites. (Spirit arrived successfully on 3 January, with Opportunity scheduled to arrive 24 January-see Figures 1 and 2.) Each rover will have an operational lifetime of 90 sols (Martian days) or more and can traverse an integrated distance of one kilometer or more, although the maximum range from the landing site might be less. Scientifically, MER seeks to • Determine the aqueous, climatic, and geologic history of a site where on Mars conditions might have been favorable to the preservation of evidence of prebiotic or biotic processes • Identify hydrologic, hydrothermal, and other processes that have operated at the landing site • Identify and investigate Martian rocks and soils that have the highest-possible chance of preserving evidence of ancient environmental conditions and possible prebiotic or biotic activity • Respond to other discoveries revealed by rover-based exploration Each sol, operations personnel on Earth receive telemetry from the rovers. On the basis of the downloaded data, they must construct, verify, and uplink a detailed sequence of commands for the next sol to the rovers. Thus, operations personnel must formulate a viable sequence that satisfies the mission goals within tight deadlines. To help address this critical need, MAPGEN can automatically generate plans and schedules for science and associated engineering activities; assist in hypothesis testing, such as what-if analysis on various scenarios; support plan editing; analyze resource usage; and perform constraint enforcement and maintenance.APGEN has served as a multimission tool for several flight projects (including Cassini and Deep Impact), while Europa flew onboard NASA's Deep Space 1 as part of a technology experiment to demonstrate the first onboard T he Mars Exploration Rover mission is one of NASA's most ambitious science missions to date.Launched in the summer of 2003, each rover carries instruments for conducting remote and in situ observations

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Kidney cortex DNA synthesis was studied in female rats treated with a low dose of gentamicin (10 mg/kg) up to 14 days. Synthesis was measured by incorporation of [3H]thymidine into DNA 1 h after intraperitoneal injection of the labeled precursor (200 muCi per animal). Gentamicin given in one injection per day resulted in a greater incorporation of [3H]thymidine into DNA after both 7 and 14 days of treatment as compared with control animals. When the daily dose was divided into three equal injections given at 8-h intervals, a statistically significant increase in thymidine incorporation was observed as early as 4 days after starting gentamicin administration. Excellent agreement was found between DNA specific radioactivity and kidney cortex nuclear labeling, as measured by histoautoradiography. The greatest amount of [3H]thymidine incorporation occurred within proximal tubular cells and interstitial cells. We conclude that a finite duration of gentamicin treatment at low dosage induces an increased DNA synthesis in vivo in rat kidney cortex. We suggest that this reaction results from cellular proliferation and could reflect a regenerative process after focal necrosis induced by gentamicin at low doses. The demonstrated early increase in DNA synthesis could be a useful tool to measure kidney cortex alterations caused by various aminoglycosides at low, therapeutic doses.