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Biomedical subjects

R Monti

Publications and source records attributed to R Monti.

At least 19 recordsLinked to original sources
PubMed2006

Production of beta-galactosidase by Trichoderma reesei FTKO-39 in wheat bran: partial purification of two isozymes.

Trichoderma reesei FTKO-39 grown at 35 degrees C for 5 d on wheat bran supplemented with MgCl2 and lactose as the carbon source produced two isozymes of beta-galactosidase: BGT I and BGT II. These isozymes were partially purified on a DEAE-Trisacryl column. Both BGT I and BGT II fractions exhibited optimum activity at 65 degrees C, but the pH optima were 4.0 and 6.5, respectively. The isozymes also showed similar thermal stability. However, BGT I was more stable than BGT II in a pH range of 3.0-10.0. At least two different beta-galactosidases are produced by T. reesei, as revealed by the two bands seen on a 6% polyacrylamide gel stained for activity.

Dietary Fiber↗
PubMed2005

Xylanases from fungi: properties and industrial applications.

Xylan is the principal type of hemicellulose. It is a linear polymer of beta-D-xylopyranosyl units linked by (1-4) glycosidic bonds. In nature, the polysaccharide backbone may be added to 4-O-methyl-alpha-D-glucuronopyranosyl units, acetyl groups, alpha-L-arabinofuranosyl, etc., in variable proportions. An enzymatic complex is responsible for the hydrolysis of xylan, but the main enzymes involved are endo-1,4-beta-xylanase and beta-xylosidase. These enzymes are produced by fungi, bacteria, yeast, marine algae, protozoans, snails, crustaceans, insect, seeds, etc., but the principal commercial source is filamentous fungi. Recently, there has been much industrial interest in xylan and its hydrolytic enzymatic complex, as a supplement in animal feed, for the manufacture of bread, food and drinks, textiles, bleaching of cellulose pulp, ethanol and xylitol production. This review describes some properties of xylan and its metabolism, as well as the biochemical properties of xylanases and their commercial applications.

Endo-1,4-beta Xylanases↗
PubMed2005

The fluid-dynamic disturbances induced on the ISS, based on the first acceleration measurements on board the space station.

The different acceleration components on the ISS that are responsible for the generation of convective motions in a fluid cell either in the presence of density gradients or in quasi-isodense processes, are analyzed. The NASA measurements of the quasi-steady and periodic acceleration on the ISS are considered and their effects on fluid-dynamic experiments are computed and discussed under different assumptions. In particular, numerical simulations are carried out to identify the relative importance of linear and pendular accelerations, due to possible rotations of the P/L around its center of mass. The effects caused by variable accelerations created by an isolation mount that exhibits an attenuation factor not constant within the payload volume, caused by the reaction forces of the umbilicals, are computed and analyzed.

Acceleration↗
PubMed2001

Controlled hydrolysis of cheese whey proteins using trypsin and alpha-chymotrypsin.

This study examined the production of protein hydrolysates with controlled composition from cheese whey proteins. Cheese whey was characterized and several hydrolysis experiments were made using whey proteins and purified beta-lactoglobulin, as substrates, and trypsin and alpha-chymotrypsin, as catalysts, at two temperatures and several enzyme concentrations. Maximum degrees of hydrolysis obtained experimentally were compared to the theoretical values and peptide compositions were calculated. For trypsin, 100% of yield was achieved; for alpha-chymotrypsin, hydrolysis seemed to be dependent on the oligopeptide size. The results showed that the two proteases could hydrolyze beta-lactoglobulin. Trypsin and alpha-chymotrypsin were stable at 40 degrees C, but a sharp decrease in the protease activity was observed at 55 degrees C.

Cheese↗
PubMed1999

Inhibitory effect of propolis and bee venom on the mutagenicity of some direct- and indirect-acting mutagens.

The antimutagenic effect of ethanolic extract of propolis (EEP) and honeybee (Apis mellifera) venom, both collected in the State of São Paulo, Brazil, was assessed by the Salmonella/microsome assay upon direct- and indirect-acting mutagens. EEP had inhibitory effect (in an ascending order) on the mutagenicity power of daunomycin (TA102), benzo(a)pyrene (TA100), and aflatoxin B(1)(TA98) and the venom acted against the mutagenicity of 4-nitro-o-phenylenediamine (TA98) and daunomycin (TA102). Teratogenesis Carcinog. Mutagen. 19:403-413, 1999.

Aflatoxin B1↗
PubMed1991

[Oxygen toxicity].

Explore the source record for details and available documents.

Free Radicals↗
PubMed1989

Telescience and microgravity impact on future facilities, ground segments and operations.

Scientific activities related to experimentation in long duration microgravity missions can only be accomplished by the implementation of the Telescience Concept. Telescience is in fact the logical answer to the need of an intelligent interactive conduct of experiments, to the lack (or very little availability) of crew time on board of the Segments of the Columbus project and to the PIs demand for decentralized operations. Telescience could also be seen as the preparative phase for the ultimate, future exploitation of Microgravity by means of Expert Systems that will utilize AI and Robotics for routine operations (Data Factories, Space Productions and Commercial Enterprises). The implications of Telescience on future Space Activities is reviewed with reference to the Principal Investigator Activities, Crew Members Roles and Facilities. The possibilities offered by newly designed Facilities to be operated in Telescience are pointed out with reference to the scientific objectives that would not be achieved otherwise. Diagnostic facilities (mainly non invasive) that provide digital measurements to be inputted (in real time) into numerical codes for computation of field parameters are being considered. Ground Segment Structure, User Support Centers Organization and Test Bedding activities will be discussed as essential factors of the Telescience Scenario of the Multiuser, permanent platform Facilities for the Microgravity disciplines (Material, Fluid, Life and Engineering Science).

Equipment Design↗
PubMed1988

Effect of superoxide dismutase on liver ischemia-reperfusion injury in the rat: a biochemical monitoring.

Oxygen free radicals have been implicated in the pathogenesis of postischemic liver injury. High-dose superoxide dismutase (SOD), a radical scavenging enzyme, has been investigated in a rat model of liver ischemia reperfusion by biochemical monitoring. Blood vessels to the median and left lobe were clamped for 1 h and then reperfusion was allowed. The indices used were serial venous blood levels of AST, ALT, calcium, and ATP determination in liver tissue. In SOD-treated animals (7,5000 U i.v.) a significant attenuation of the rise in enzyme levels was observed as well as the absence of the decrease in calcium level in the early phase after reperfusion as compared with control rats, and furthermore ATP restoration was significantly increased.

Adenosine Triphosphate↗