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Biomedical subjects

S Andres

Publications and source records attributed to S Andres.

8 recordsLinked to original sources
PubMed2001

Phenotypic and functional comparison of monocytes from cord blood and granulocyte colony-stimulating factor-mobilized apheresis products.

OBJECTIVE: It is well established that T cells are effector cells in graft-vs-host disease (GVHD), yet the contribution of graft monocytes is less well characterized. Therefore, monocytes in cord blood (CB) and granulocyte colony-stimulating factor-mobilized apheresis products (G-AP), two stem cell grafts associated with reduction of acute and chronic GVHD and relative reduction of acute GVHD, respectively, were compared phenotypically and functionally. MATERIALS AND METHODS: The frequencies, phenotypes, and pinocytosis activities of monocytes from CB and G-AP were determined by flow cytometry and their allostimulatory potential in a primary mixed leukocyte reaction. RESULTS: G-AP contained significantly more monocytes than CB (24.9% +/- 7.1% vs 8.8% +/- 1.5% CD14+ and 62.4 +/- 27.5 x 10(6) vs 0.9 +/- 0.2 x 10(6) CD14+ cells/mL). Monocytes from both sources revealed similar phenotypes. They expressed CD4, CD11a, CD11b, CD11c, CD18, CD32, CD33, CD45R0, CD48, CD50, CD54, CD58, CD64, CD86, CD102, CD116, CD123, and HLA-DR; showed no expression of CD1a and CD83; and weak expression of CD16, CD45RA, and CD80. The levels of CD80 and CD86 expression were comparable; however, in contrast to G-AP monocytes, CB monocytes lacked CD40. There was no difference in pinocytosis activity and allostimulatory capacity of CB and G-AP monocytes. CONCLUSIONS: Monocytes in CB and G-AP are phenotypically and functionally comparable. The only difference observed is the lack of CD40 on CB monocytes.

Antigen Presentation↗
PubMed2000

Interspecific comparison of cadmium and zinc contamination in the organs of four fish species along a polymetallic pollution gradient (Lot River, France).

The impact of cadmium (Cd) and zinc (Zn) discharges related to an old zinc ore treatment facility in the Lot River (France) was investigated in four fish species (the chub: Leusciscus cephalus, the roach: Rutilus rutilus, the perch: Perca fluviatilis and the bream: Abramis brama). The organisms were sampled in four stations along the polymetallic contamination gradient. Cd and Zn analysis were carried out in five organs (gills, posterior intestine, liver, kidneys and skeletal muscle) in order to highlight the potential pathways of uptake, storage and elimination of metals. The results indicate a very strong Cd contamination in fish collected downstream from the metal source. The kidneys have the highest cadmium concentrations, but the gills and the intestine, as exchange organs, present the largest variations between the stations in close relation with the contamination gradient. Cd concentrations measured in the liver vary only slightly among the sampling stations. Unlike the trends observed for Cd, Zn levels in fish populations are strongly regulated and do not follow ambient Zn concentrations. The concentrations measured vary also according to fish species, for both Cd and Zn. This study shows that the trophic habits can explain the interspecific differences in Cd bioaccumulation. Zn levels observed for each species in non-contaminated populations also help to understand metal bioaccumulation patterns in polluted sites, suggesting that the determinism of interspecific differences is constitutive.

Animals↗
PubMed2000

Factors controlling the bioaccumulation of mercury, methylmercury, arsenic, selenium, and cadmium by freshwater invertebrates and fish.

Concentrations of mercury (Hg), methylmercury (MMHg), arsenic (As), selenium (Se), and cadmium (Cd) were measured in atmospheric deposition, stream water, and biota in two streams in western Maryland. Overall, concentrations were slightly higher in the water of the lower pH Herrington Creek tributary (HRCT). Bioaccumulation factors were also higher for HRCT compared to Blacklick Run (BLK). MMHg concentrations in biota increased with trophic level and essentially all the Hg was as MMHg in predatory insects and insectivorous/carnivorous fish. Thus, the overall trophic status of the organism was indicated by the %MMHg in its tissues. Levels of As, Se, Cd, and Hg, however, decreased with increasing trophic level. Adsorption of As to the exoskeleton of invertebrates appears to be an important accumulation mechanism. MMHg was distributed evenly throughout crayfish and fish organs, whereas As, Se, Cd, and Hg were found in higher concentrations in detoxifying organs. Concentrations in biota in this study were somewhat elevated compared to other rural sites, but were less than those of point source-contaminated sites. Overall, as atmospheric inputs to the two watersheds were similar, the results of this study show the importance of water chemistry in determining the bioaccumulation of the metals and metalloids into insects. Subsequent transfer to higher trophic levels is related to both the ability of the organisms to depurate and the mode of accumulation, either directly from water or from food.

Animals↗
PubMed1999

Temporal variations in blood glutathione peroxidase (GSHPx) activity in sheep at pasture in a Mediterranean area.

The present study evaluates blood GSHPx activity in 18 sheep flocks at range, to identify those seasons with the highest risk of selenium deficiency. Samples were taken from 1108 15-day-old lambs during the two usual lambing periods in this geographical area (autumn-winter and spring-summer). The overall mean values in the first period (146.69 +/- 3.41 i.u./g Hb) was higher than in the second one (107.50 +/- 3.53 i.u./g Hb). This may be explained by the special features of the climate in the Mediterranean area, which allow an optimum growth of grass from October to May. Therefore, the lambs born in spring-summer are from pregnancies in months when feeding is based only upon grazing. However, lambs born in autumn-winter comes from ewes gestating during the summer, when supplementation with cereal grains is given. As a conclusion, lambs born in spring-summer in this area are at higher risk to selenium-deficiency related disorders.

Animals↗
PubMed1998

Effects of Temperature and Exposure Duration on Transfer of Cadmium Between Naturally Contaminated Sediments and Burrowing Mayfly Nymphs (Hexagenia rigida)

Burrowing mayfly nymphs (Hexagenia rigida) were exposed to naturally contaminated sediments collected from two stations along a metallic pollution gradient on the Lot River (France) using indoor microcosms. Bioaccumulation kinetics (0, 20, 40, and 60 days) of cadmium (Cd) and the combined effects of temperature (12, 18, and 24 degreesC) were evaluated by a complete experimental design, jointly with the analysis of growth rate of the nymphs, bioturbation, and total and dissolved Cd concentrations in the water column. Cadmium was transferred from the sediment to the organisms with uptake influenced by contamination levels of the sediments, exposure duration, and temperature. The two complementary criteria-Cd concentration and burden in the nymphs-clearly demonstrate the importance of the growth dilution on the quantification of Cd bioaccumulation at the whole organism level.

Journal Article↗
PubMed1992

Implementing right-to-know legislation for health care workers in Manitoba: a bipartite sectoral train-the-trainer approach.

In October 1988, right-to-know legislation was introduced in Canada. This presented a technical and administrative challenge to the health care sector. With over 170 health care facilities in Manitoba to be brought into compliance, some large, some small, some rural, some urban, a cooperative approach was needed. A labor-management steering committee with representatives from a cross-section of facilities as well as the various health care unions was formed to design and implement a train-the-trainer program. A small-group, highly participatory modular program was developed with input from all parties, and delivered across the province by trainers selected jointly by labor and management. The program achieved its goal of assisting member facilities to implement the legislation. Follow-up surveys and discussions with health care workers showed improved understanding of labelling requirements, material safety data sheet interpretation, and requirements for hazard control. This first bipartite program empowered the health care workforce to use its newly acquired right-to-know, and has provided the incentive to implement other cooperative safety and health programs.

Evaluation Studies as Topic↗