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At least 37 records · Page 2Linked to original sources
PubMed2002

Experiences with MARS liver support therapy in liver failure: analysis of 176 patients of the International MARS Registry.

Extracorporeal liver support using the MARS recently has shown remarkable results in several trials. This study aims to extend the basis for analyses by making available the worldwide data with help of an international registry. One hundred and seventy six patients were analysed, main indications are acute-on-chronic liver failure (56%), acute liver failure (22%), primary graft dysfunction (15%), liver failure post liver surgery (4%) and miscellaneous (3%). The predicted survival within the first group based on a mean MELD score of 30.4 pts. and a mean Child score of 12.6 pts. was quite limited. The data suggest an improved survival accompanied by significant improvements of hepatic encephalopathy, mean arterial pressure, serum bilirubin level, creatinine, urea, albumin, INR, ammonia and MELD score. The results are confirming observations of other trials before which have shown MARS therapy to be an effective and safe extracorporeal liver support in liver failure.

Acute Disease↗
PubMed1997

Selection of multiple-antibiotic-resistant (mar) mutants of Escherichia coli by using the disinfectant pine oil: roles of the mar and acrAB loci.

Mutants of Escherichia coli selected for resistance to the disinfectant pine oil or to a household product containing pine oil also showed resistance to multiple antibiotics (tetracycline, ampicillin, chloramphenicol, and nalidixic acid) and overexpressed the marA gene. Likewise, antibiotic-selected Mar mutants, which also overexpress marA, were resistant to pine oil. Deletion of the mar or acrAB locus, the latter encoding a multidrug efflux pump positively regulated in part by MarA, increased the susceptibility of wild-type and mutant strains to pine oil.

Ampicillin↗
PubMed2006

Mars 1064 nm spectral radiance measurements determined from the receiver noise response of the Mars Orbiter Laser Altimeter.

A technique was developed to compute the radiance of the scene viewed by the optical receiver of the Mars Orbiter Laser Altimeter. The technique used the detection threshold and the false detection rate of the receiver to provide a passive radiometry measurement of Mars at the 1064 nm wavelength over a 2 nm bandwidth and subkilometer spatial resolution in addition to the altimetry and active radiometry measurements. The passive radiometry measurement is shown to have a 2% or better precision and has been stable over several Martian years. We describe the principle of operation of the instrument and its calibration and assess its performance from sample orbital measurements.

Journal Article↗
PubMedDate not supplied

MArs Neutron Energy Spectrometer (MANES): an instrument for the Mars 2003 Lander.

We describe the instrument design and detector development for MANES which has been selected to fly on the Mars 2003 Lander. Section 1 explains the need for the spectrometer in determining the increased risk of carcinogenesis for astronauts. Section 2 presents the instrument design including an outline drawing, a cross-sectional view and a detailed block diagram. Sections 3 and 4 describe the low and high energy detector components of the spectrometer and present responses to monoenergetic neutron beams. Sections 5 and 6 explain the design approaches to charged particle discrimination and instrument transfer function modeling.

Equipment Design↗
PubMed2002

Global distribution of neutrons from Mars: results from Mars odyssey.

Global distributions of thermal, epithermal, and fast neutron fluxes have been mapped during late southern summer/northern winter using the Mars Odyssey Neutron Spectrometer. These fluxes are selectively sensitive to the vertical and lateral spatial distributions of H and CO2 in the uppermost meter of the martian surface. Poleward of +/-60 degrees latitude is terrain rich in hydrogen, probably H2O ice buried beneath tens of centimeter-thick hydrogen-poor soil. The central portion of the north polar cap is covered by a thick CO2 layer, as is the residual south polar cap. Portions of the low to middle latitudes indicate subsurface deposits of chemically and/or physically bound H2O and/or OH.

Dry Ice↗
PubMed1998

Observations of the north polar region of Mars from the Mars orbiter laser altimeter.

Elevations from the Mars Orbiter Laser Altimeter (MOLA) have been used to construct a precise topographic map of the martian north polar region. The northern ice cap has a maximum elevation of 3 kilometers above its surroundings but lies within a 5-kilometer-deep hemispheric depression that is contiguous with the area into which most outflow channels emptied. Polar cap topography displays evidence of modification by ablation, flow, and wind and is consistent with a primarily H2O composition. Correlation of topography with images suggests that the cap was more spatially extensive in the past. The cap volume of 1.2 x 10(6) to 1.7 x 10(6) cubic kilometers is about half that of the Greenland ice cap. Clouds observed over the polar cap are likely composed of CO2 that condensed out of the atmosphere during northern hemisphere winter. Many clouds exhibit dynamical structure likely caused by the interaction of propagating wave fronts with surface topography.

Carbon Dioxide↗
PubMed1999

The gravity field of Mars: results from Mars Global Surveyor.

Observations of the gravity field of Mars reveal a planet that has responded differently in its northern and southern hemispheres to major impacts and volcanic processes. The rough, elevated southern hemisphere has a relatively featureless gravitational signature indicating a state of near-isostatic compensation, whereas the smooth, low northern plains display a wider range of gravitational anomalies that indicates a thinner but stronger surface layer than in the south. The northern hemisphere shows evidence for buried impact basins, although none large enough to explain the hemispheric elevation difference. The gravitational potential signature of Tharsis is approximately axisymmetric and contains the Tharsis Montes but not the Olympus Mons or Alba Patera volcanoes. The gravity signature of Valles Marineris extends into Chryse and provides an estimate of material removed by early fluvial activity.

Atmosphere↗
PubMed1998

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.

Journal Article↗
PubMedDate not supplied

The Mars oxidant experiment (MOx) for Mars '96.

The MOx instrument was developed to characterize the reactive nature of the martian soil. The objectives of MOx were: (1) to measure the rate of degradation of organics in the martian environment; (2) to determine if the reactions seen by the Viking biology experiments were caused by a soil oxidant and measure the reactivity of the soil and atmosphere: (3) to monitor the degradation, when exposed to the martian environment, of materials of potential use in future missions; and, finally, (4) to develop technologies and approaches that can be part of future soil analysis instrumentation. The basic approach taken in the MOx instrument was to place a variety of materials composed as thin films in contact with the soil and monitor the physical and chemical changes that result. The optical reflectance of the thin films was the primary sensing-mode. Thin films of organic materials, metals, and semiconductors were prepared. Laboratory simulations demonstrated the response of thin films to active oxidants.

Electron Probe Microanalysis↗
PubMed1998

Early views of the martian surface from the Mars Orbiter Camera of Mars Global Surveyor.

High-resolution images of the martian surface at scales of a few meters show ubiquitous erosional and depositional eolian landforms. Dunes, sandsheets, and drifts are prevalent and exhibit a range of morphology, composition (inferred from albedo), and age (as seen in occurrences of different dune orientations at the same location). Steep walls of topographic depressions such as canyons, valleys, and impact craters show the martian crust to be stratified at scales of a few tens of meters. The south polar layered terrain and superposed permanent ice cap display diverse surface textures that may reflect the complex interplay of volatile and non-volatile components. Low resolution regional views of the planet provide synoptic observations of polar cap retreat, condensate clouds, and the lifecycle of local and regional dust storms.

Carbon Dioxide↗
PubMed1990

[The treatment of imported Plasmodium falciparum malaria with halofantrine. Apropos of 59 case reports (corrected and republished article orginally printed in Med Trop (Mars) 1990 Jan-Mar;50(1):113-7)].

59 cases of Plasmodium falciparum malaria fever occurring in non-immune Caucasian subjects having got a correct chemoprophylaxis by chloroquine were treated by halofantrine (HALFAN). They were given 1500 mg divided in 3 doses of 500 mg every 6 hours from D1 to D8. All them were back from a malarial highly endemic zone with chloroquine resistance. Analysis of the main biological and clinical efficiency parameters displayed very satisfactory results: disappearances of fever (mean 22 H) and parasitemia (mean 36 H) are short. After two months of monitoring, no malaria recrudescence was noted. With an efficacy of 10 p.c. associated to a noticeable clinical and biological tolerance Halofantrine is a first-class treatment of chloroquine resistant malaria fever.

Adolescent↗
PubMed2003

MARS therapy in critically ill patients with advanced malignancy: a clinical and technical report.

BACKGROUND/METHODS: Molecular Adsorbent Recirculating System (MARS) was used in three consecutive critically ill patients at the Singapore General Hospital with advanced malignancy and acute liver failure (ALF). Case 1 was a male patient with hepatocellular carcinoma (HCC) for which initial right hepatectomy was followed by left hepatectomy 5 months later for recurrent HCC. The postoperative course following second surgery was complicated by severe methicillin-resistant Staphylococcus aureus (MRSA) sepsis, mild azotaemia and subacute cholestatic liver failure. MARS was used thrice in this patient. Case 2 was a female patient with advanced acute lymphoblastic leukaemia (ALL) with post bone marrow transplantation (BMT) acute haemolytic-uraemic syndrome (HUS) secondary to cyclosporin A (Cy A), cytomegalovirus (CMV) infection, severe nosocomial pneumonia, acute renal failure (ARF) treated with continuous haemofiltration and acute veno-occlusive disease resulting in Budd-Chiari syndrome. The latter precipitated ALF. MARS was instituted twice. Case 3 was a male patient with advanced, refractory Hodgkin's disease previously treated with multiple courses of chemotherapy. ALF developed secondary to acute viral hepatitis B flare. He was given a trial of MARS once in the ICU. All the three patients eventually died. RESULTS: Mean MARS intradialytic systemic pressures were as follows: systolic pressure range was 95 +/- 17 to 128 +/- 17 mmHg and diastolic pressure range was 51 +/- 5 to 67 +/- 7 mmHg. Pressure at albumin dialysate exit point from dialyser 1 (Ae) ranged from 253 +/- 11 to 339 +/- 15 mmHg and that at albumin dialysate entry point into dialyser 1 (Aa) ranged from 142 +/- 11 to 210 +/- 6 mmHg. Ultrafiltration (UF) was 633 +/- 622 mL over mean treatment duration of 6.3 +/- 0.9 h with a total heparin dose of 1583 +/- 817 IU. Coagulation status pre- and 6-h post-MARS was similar: aPTT (P=0.116) and platelet count (P=0.753). There were no bleeding complications or circuit thromboses. MARS had a significant de-uraemization effect (pre- and post-MARS serum creatinine and urea: P=0.046 and 0.028, respectively) but did not significantly attenuate blood lactate, ammonia or total bilirubin levels. Albumin dialysate (Ae - Aa) urea and creatinine concentrations appeared to be sharply attenuated after 6 h of MARS. In contrast, the removal of total bilirubin by albumin dialysate from the blood compartment appeared to plateau after 4 h of continuous MARS operation. CONCLUSIONS: MARS was well-tolerated in critically ill patients with advanced and complicated cancer. Low-dose heparin was safe and did not compromise MARS circuit integrity. Although MARS had a significant de-uraemization effect, this appeared to be limited by the duration of MARS operation. Our data suggested that such a limit was reached earlier for total bilirubin. More data are needed to confirm the present findings and further delineate the saturation limit of MARS for different toxins that accumulate in ALF. This would affect the optimal duration of MARS therapy.

Adolescent↗
PubMed1990

A novel monoclonal antibody, Mar 1, directed specifically against mononuclear phagocyte system cells in rats.

Three different monoclonal antibodies (mAb), designated Mar 1, Mar 2, and Mar 3, recognizing three distinct novel antigen molecules expressed preferentially in rat macrophages, were produced by the hybridoma technique. Binding of these mAb to isolated cells or fixed cells was detected by radioactive binding assay, immunohistochemical technique and flow cytometry. Mar 1 binds specifically to the cells constituting the mononuclear phagocyte system (MPS), but not to granulocytes nor endocytosis-positive cells from non-lymphoid tissues. Mar 2 and Mar 3 recognize both the former and the latter. The isotypes of Mar 1, Mar 2 and Mar 3 were defined as IgG1, IgG1 and IgG2b, respectively. These mAb were species specific, allo-non-specific and not cytotoxic for rat peritoneal macrophages. Immunoelectron microscopic observation demonstrated that Mar 1-3 antigens are located on both surface membrane and cytoplasmic membrane structures of peritoneal macrophages, particularly on the limiting membrane of phagocytic small vesicles and large phagosomes. Immunoprecipitation experiments demonstrated that the apparent molecular weights (MW) of the reactive antigens of Mar 1, Mar 2 and Mar 3 are 95,000, 100,000 and 55,000 and 27,000, respectively. These findings indicate that all of Mar 1-3 mAb have considerable value in the identification of rat phagocytes and that, of the three kinds of antigens detected with Mar 1-3, Mar 1 antigen is a specific marker for identification of the cells constituting the MPS and may offer the means to assess the functional capability and differentiation process of the macrophage populations.

Animals↗
PubMed2003

Successful use of Molecular Absorbent Regenerating System (MARS) dialysis for the treatment of fulminant hepatic failure in children accidentally poisoned by toxic mushroom ingestion.

BACKGROUND: Acute liver failure (ALF) as a result of mushroom poisoning is associated with a high mortality (particularly in children), despite optimal medical therapy (OMT), including charcoal haemoperfusion and haemodiafiltration. MARS is a new, cell-free, extracorporeal liver assistance method utilizing an albumin dialysate for the removal of albumin-bound toxins. METHODS: We describe the first series in the literature (also first MARS treatments in Romania) with ALF because of mushroom poisoning in children (M/F=2/4, age=7-16 years). Liver function was evaluated pre-MARS and 15-min post-MARS, 24 h following each treatment and 30 days post-MARS. FINDINGS: All patients had severe hepatic dysfunction: hepatic encephalopathy (HE; four grade II, one grade III, one grade IV), ALT=4082 (3400-5600) IU/L, bilirubin=6.3 (2-10) mg/dL, prothrombin time (PT)=52.5 (23-141) s. MARS was uneventful and well-tolerated. Two 6-h sessions per patient were performed with a similar immediate impact on liver tests: mean drop in ALT of -33 and -35%, respectively, and in bilirubin of -39 and -36%, respectively. ALT levels 24 h following MARS-1, remained unchanged but continued to drop by a further -28% following MARS-2. By contrast, all patients had a significant rebound in bilirubin (+39%) 24 h following MARS-1; however, following MARS-2 a rebound was seen only in two cases (+220%). PT improved by 37% after MARS-1 and normalized in four patients after MARS-2. OUTCOME: Four patients survived and completely recovered the hepatic function. Negative prognostic markers: lack of complete correction of PT, continuous rebound and increase in bilirubin, and lack of improvement in HE post-MARS-1. Survival in six well-matched cases, treated by OMT=0/6 (P<0.05). CONCLUSIONS: MARS is a safe and highly effective depurative therapy in children with ALF. Survival is predicted only by the impact/results of the initial MARS sessions and not by any of the baseline parameters.

Adolescent↗