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Satomi Kato

Publications and source records attributed to Satomi Kato.

7 recordsLinked to original sources
PubMed2006

TRB3 modulates C2C12 differentiation by interfering with Akt activation.

TRB3 is a member of TRB protein family characterized by containing a variant kinase domain without enzymatic activity. Interacting with Ser/Thr protein kinases Akt, TRB3 impairs Akt activation induced by growth factors and insulin. In this study we have examined the potential role of TRB3 in muscle differentiation. Our data indicated that the expression of TRB3 is downregulated during C2C12 cells undergoing muscle differentiation and that overexpression of TRB3 inhibits Akt activation during differentiation. Correspondingly, overexpression of TRB3 inhibits, while knockdown TRB3 enhances C2C12 differentiation. Thus, our studies indicated that TRB3 plays a critical role in muscle differentiation.

Animals↗
PubMed2004

Cryptosporidium parvum oocyst inactivation in field soil and its relation to soil characteristics: analyses using the geographic information systems.

The need exists to understand the environmental parameters that affect inactivation of Cryptosporidium parvum oocysts in soil under field conditions. The inactivation of C. parvum oocysts placed in the natural environment was studied at a dairy farm in western New York State, USA. Seventy sampling points were arranged in a grid with points 150 m apart using the Geographic Information System. The sampling points were distributed among three distinct areas: woodland, corn field and pasture. Purified oocysts were inoculated into chambers filled with soil from each sampling point, and buried in the surface of each respective sampling point. To compare C. parvum oocyst survival with another organism known to survive environmental stresses, Ascaris suum eggs were also placed in soil contained in chambers and buried at the same sampling points as the oocysts. As controls oocysts and eggs in distilled water were also placed at each sampling point. Oocyst and egg viability, soil pH and percent gravimetric water content were measured at all sampling points at 0, 60 and 120 day sampling periods. Soil organic content was determined for each sampling point. At 120 days after placement, mean viability of C. parvum oocysts was 10% although at a few sampling points, 30% of oocysts were still potentially infective; whereas 90% of A. suum eggs were viable at all sampling points. Statistically significant differences were not observed among the three different sampling areas, and no statistically significant predictors were found by regression analysis. Results exemplified the heterogeneity of soil parameters and oocyst viability across a landscape; such results make predictive models for C. parvum inactivation problematical. The long-term survival of C. parvum oocysts in soil under field conditions, as this study demonstrated, emphasizes their potential as a risk to contaminate surface waters.

Agriculture↗
PubMed2003

Utility of the Cryptosporidium oocyst wall protein (COWP) gene in a nested PCR approach for detection infection in cattle.

A preliminary molecular epidemiological study was carried out to investigate the utility of the Cryptosporidium oocyst wall protein (COWP) gene in the detection of Cryptosporidium oocysts in fecal samples. A nested polymerase chain reaction (PCR) approach using COWP gene primers was adopted for this purpose. Fecal samples were spiked with each of 1, 10, and 100 oocysts of C. parvum, four samples for each number, and the DNA was extracted from each sample using a glassbead method. The presence of oocysts was determined using the nested PCR with COWP gene primers, and the limit of detection of oocysts by the PCR was determined. The limit of detection was 100 oocysts spiked in 1 ml of fecal material (50% sold material) (four positives/four samples tested). Seventy-five percent of DNA extracted samples spiked with 1 and 10 oocysts was positive by the PCR (three positives/four samples tested). Based on this, small sample size using the COWP gene primers with a nested PCR analysis could reliably identify infected animals rather conveniently and accurately.

Animals↗
PubMed2003

Effect of aerobic and anaerobic digestion on the viability of Cryptosporidium parvum oocysts and Ascaris suum eggs.

The viability of Cryptosporidium parvum oocysts and Ascaris suum eggs inoculated into aerobic and anaerobic digesters was measured. The digesters were maintained at 37 degrees C, 47 degrees C, and 55 degrees C, with 10-day detention times. Eggs and oocysts were added to each digester in a single spike or in chambers placed in the digesters for varying periods. Oocysts were inactivated very rapidly in all systems as determined by a dye permeability assay, > 99% inactivated after 10 days at 37 degrees C, 4 days at 47 degrees C, and 2 days at 55 degrees C. Eggs were more rapidly inactivated in anaerobic digesters than in aerobic digesters. At 55 degrees C, eggs in both anaerobic and aerobic digesters were > 99% inactivated within 1 h. At 47 degrees C, anaerobic digestion inactivated around 95% eggs in 2 days, but around 25% of the eggs were still viable after 10 days in aerobic digesters. At 37 degrees C, anaerobic digestion inactivated more than 75% of the eggs after 10 days, but in the aerobic digester at 37 degrees C, 10 days of treatment had no effect on viability. The oocysts and eggs added in chambers appeared to behave similarly to these pathogens added directly to the biosolids within the digesters.

Animals↗
PubMed2002

Using flow cytometry to determine the viability of Cryptosporidium parvum oocysts extracted from spiked environmental samples in chambers.

Cryptosporidium parvum oocyst viability was determined by a dye permeability assay using a flow cytometric method. Oocysts were inoculated into small chambers with soil and biosolids. Oocysts extracted from soil and biosolids were then stained with propidium iodide (PI) and labeled with a fluorescein isothiocyanate (FITC)-conjugated monoclonal antibody. The oocyst population in each sample was determined using forward and side scatter plots, then further analyzed with fluorescence. A red and green fluorescence detector using gates established single populations of unstained, PI-stained, or FITC-labeled oocysts. No statistical difference was observed between viability of oocysts extracted from soil and biosolids as determined by either flow cytometry or microscopy. The location of excysted oocysts was changed in forward and side scatter plots. Results indicated that, although oocysts are not identified if they excyst, the flow cytometric method could be used to determine oocyst viability from spiked environmental samples.

Animals↗
PubMed2002

Effects of freeze-thaw events on the viability of Cryptosporidium parvum oocysts in soil.

The effects of freeze-thaw events on the inactivation of Cryptosporidium parvum oocysts in soil were examined. Oocysts were inoculated into distilled water in microcentrifuge tubes or into chambers containing soil the water content of which was maintained at 3%, 43%, or 78% of the container capacity. The chambers and tubes were then embedded in 3 soil samples from different aspects of a hillside landscape (Experiments 1 and 2) and in 3 distinct soil types (Experiment 3) and frozen at -10 C. Containers were thawed every 3 days for a period of 24 hr in 1-9 freeze-thaw cycles over 27 days (Experiments 1 and 2) and 2-5 freeze-thaw cycles over 15 days (Experiment 3). Oocyst viability was measured using the fluorescent dyes 4'6-diaminidino-2-phenylindole and propidium iodide. Inactivation rates were greater in soils than in water and greater in dry soil than in moist and wet soils. Soil type showed no effect on inactivation. Oocysts subjected to freeze-thaw cycles had inactivation rates not significantly different from those of oocysts subjected to -10 C under static conditions. The results indicated that 99% of oocysts exposed to soils that are frozen at -10 C will become inactivated within 50 days whether or not freeze-thaw cycles occur.

Animals↗