Quantitative analysis of the chimeric state in mice: III. Comparison of the colonizing capacities of syngeneic cell suspensions from different sources

Cytological analysis of the lymphoid organs of mice neonatally injected with syngeneic cell suspensions derived from different sources showed that the proportions of donor cells in the host spleen, thymus and bone marrow were low, irrespective of the type of suspension administered at birth. In contrast, the proportions of donor cells found in the host lymph nodes were for all inocula demonstrably higher than those found in other lymphoid organs. Various types of inocula, however, displayed different lymph node colonizing capacities depending upon the tissue from which the inoculum was prepared. The order of the lymph node colonizing properties showed a fair correlation with the known order of tolerance-conferring capacities of these inocula. Both phenomena are in accord with the hypothesis that the higher the content in recirculating small lymphocytes in a given tissue, the higher the capacity of the inoculum prepared from that tissue to colonize the host lymph node system and to induce tolerance

Shipboard Measurements of Nitrogen Dioxide, Nitrous Acid, Nitric Acid and Ozone in the Eastern Mediterranean Sea

Measurements of nitrogen dioxide, nitrous and nitric acids as well as ozone were made using newly developed instrumentation onboard the research vessel Aegeon in the Aegean Sea between 25th-29th July 2000. Typical nitrogen dioxide concentrations observed aboard the boat were 4-6 ppb (v/v) with a broad maximum of 20-30 ppb (v/v). Ozone concentrations typically ranged between 40 and 80 ppb (v/v). Mixing ratios of both nitric and nitrous acids in the ambient air of the Aegean Sea were mainly below 50 ppt (v/v). The data also showed a number of short pollution episodes with rapid changes in the concentration of reactive nitrogen compounds [nitrogen dioxide maximum up to 164 ppb (v/v), nitric acid maximum up to 12 ppb (v/v), nitrous acid maximum up to 2.7 ppb (v/v)] and ozone [maximum up to 88 ppb (v/v)]. These episodes were correlated with pollution plumes originating from boats upwind, at short distance, from the R/V Aegeon. The measurements revealed the importance of nitrous and nitric acids for the transport of nitrogen to marine biota in busy ship lanes. © 2007 Springer Science+Business Media B.V

Quantitative analysis of the chimeric state in mice: IV. Cytological examination of mice rendered tolerant by neonatal inoculation of F(1) hybrid spleen cells

Newborn CBA mice were injected intraperitoneally with adult F(1) hybrid spleen cells chromosomally distinguishable from host cells (T6). Two donor—host combinations were studied: (A×CBA)F(1)→CBA and (C57×CBA)F(1)→CBA. Chimeric analyses of host lymphoid organs were performed between days 8 and 260 post-natal in the former and between days 5 and 567 in the latter donor—host combination. Mice injected with (A×CBA)F(1) hybrid cells yielded uniformly low frequencies of donor cells in the spleen, thymus, bone marrow and caecum lymphoid tissue throughout the duration of the experiment; relatively high proportions of donor cells were identified during the first 3 weeks of life in the lymph nodes and Peyer's patches, but there was a subsequent slow but steady fall to low values. A similar phenomenon was noted also in the (C57×CBA)F(1)→CBA combination, so that after the 18th month of life few donor cells were found in all lymphoid organs examined. Despite marked fall in the degree of chimerism specific tolerance, as tested by repeated skin grafting, was fully maintained. Comparison of the results of chimeric analysis of hybrid→parent combinations with the results obtained in mice neonatally injected with similar numbers of either syngeneic or allogeneic spleen cells gave some insight into the mechanism of induction of `acquired tolerance', the speed by which tolerance is induced and the degree of tolerance attained

Shipboard measurements of ozone, nitrogen dioxide, nitrous and nitric acids, and sulfur dioxide in the eastern Mediterranean

Μη διαθέσιμη περίληψηNot available summarizationΠαρουσιάστηκε στο: 6th Czech and Slovakian Conference "Ovzduší 200

Sub-chronic inhalation of lead oxide nanoparticles revealed their broad distribution and tissue-specific subcellular localization in target organs

Abstract Background Lead is well known environmental pollutant, which can cause toxic effects in multiple organ systems. However, the influence of lead oxide nanoparticles, frequently emitted to the environment by high temperature technological processes, is still concealed. Therefore, we investigate lead oxide nanoparticle distribution through the body upon their entry into lungs and determine the microscopic and ultramicroscopic changes caused by the nanoparticles in primary and secondary target organs. Methods Adult female mice (ICR strain) were continuously exposed to lead oxide nanoparticles (PbO-NPs) with an average concentration approximately 106 particles/cm3 for 6 weeks (24 h/day, 7 days/week). At the end of the exposure period, lung, brain, liver, kidney, spleen, and blood were collected for chemical, histological, immunohistochemical and electron microscopic analyses. Results Lead content was found to be the highest in the kidney and lungs, followed by the liver and spleen; the smallest content of lead was found in brain. Nanoparticles were located in all analysed tissues and their highest number was found in the lung and liver. Kidney, spleen and brain contained lower number of nanoparticles, being about the same in all three organs. Lungs of animals exposed to lead oxide nanoparticles exhibited hyperaemia, small areas of atelectasis, alveolar emphysema, focal acute catarrhal bronchiolitis and also haemostasis with presence of siderophages in some animals. Nanoparticles were located in phagosomes or formed clusters within cytoplasmic vesicles. In the liver, lead oxide nanoparticle exposure caused hepatic remodeling with enlargement and hydropic degeneration of hepatocytes, centrilobular hypertrophy of hepatocytes with karyomegaly, areas of hepatic necrosis, occasional periportal inflammation, and extensive accumulation of lipid droplets. Nanoparticles were accumulated within mitochondria and peroxisomes forming aggregates enveloped by an electron-dense mitochondrial matrix. Only in some kidney samples, we observed areas of inflammatory infiltrates around renal corpuscles, tubules or vessels in the cortex. Lead oxide nanoparticles were dispersed in the cytoplasm, but not within cell organelles. There were no significant morphological changes in the spleen as a secondary target organ. Thus, pathological changes correlated with the amount of nanoparticles found in cells rather than with the concentration of lead in a given organ. Conclusions Sub-chronic exposure to lead oxide nanoparticles has profound negative effects at both cellular and tissue levels. Notably, the fate and arrangement of lead oxide nanoparticles were dependent on the type of organs

Sub-chronic inhalation of lead oxide nanoparticles revealed their broad distribution and tissue-specific subcellular localization in target organs

Abstract Background Lead is well known environmental pollutant, which can cause toxic effects in multiple organ systems. However, the influence of lead oxide nanoparticles, frequently emitted to the environment by high temperature technological processes, is still concealed. Therefore, we investigate lead oxide nanoparticle distribution through the body upon their entry into lungs and determine the microscopic and ultramicroscopic changes caused by the nanoparticles in primary and secondary target organs. Methods Adult female mice (ICR strain) were continuously exposed to lead oxide nanoparticles (PbO-NPs) with an average concentration approximately 106 particles/cm3 for 6 weeks (24 h/day, 7 days/week). At the end of the exposure period, lung, brain, liver, kidney, spleen, and blood were collected for chemical, histological, immunohistochemical and electron microscopic analyses. Results Lead content was found to be the highest in the kidney and lungs, followed by the liver and spleen; the smallest content of lead was found in brain. Nanoparticles were located in all analysed tissues and their highest number was found in the lung and liver. Kidney, spleen and brain contained lower number of nanoparticles, being about the same in all three organs. Lungs of animals exposed to lead oxide nanoparticles exhibited hyperaemia, small areas of atelectasis, alveolar emphysema, focal acute catarrhal bronchiolitis and also haemostasis with presence of siderophages in some animals. Nanoparticles were located in phagosomes or formed clusters within cytoplasmic vesicles. In the liver, lead oxide nanoparticle exposure caused hepatic remodeling with enlargement and hydropic degeneration of hepatocytes, centrilobular hypertrophy of hepatocytes with karyomegaly, areas of hepatic necrosis, occasional periportal inflammation, and extensive accumulation of lipid droplets. Nanoparticles were accumulated within mitochondria and peroxisomes forming aggregates enveloped by an electron-dense mitochondrial matrix. Only in some kidney samples, we observed areas of inflammatory infiltrates around renal corpuscles, tubules or vessels in the cortex. Lead oxide nanoparticles were dispersed in the cytoplasm, but not within cell organelles. There were no significant morphological changes in the spleen as a secondary target organ. Thus, pathological changes correlated with the amount of nanoparticles found in cells rather than with the concentration of lead in a given organ. Conclusions Sub-chronic exposure to lead oxide nanoparticles has profound negative effects at both cellular and tissue levels. Notably, the fate and arrangement of lead oxide nanoparticles were dependent on the type of organs

Estimation of NH3 emissions from a naturally ventilated livestock farm using local-scale atmospheric dispersion modelling

Agricultural livestock represents the main source of ammonia (NH3) in Europe. In recent years, reduction policies have been applied to reduce NH3 emissions. In order to estimate the impacts of these policies, robust estimates of the emissions from the main sources, i.e. livestock farms are needed. In this paper, the NH3 emissions were estimated from a naturally ventilated livestock farm in Braunschweig, Germany during a joint field experiment of the GRAMINAE European project. An inference method was used with a Gaussian-3D plume model and with the Huang 3-D model. NH3 concentrations downwind of the source were used together with micrometeorological data to estimate the source strength over time. Mobile NH3 concentration measurements provided information on the spatial distribution of source strength. The estimated emission strength ranged between 6.4±0.18 kg NH3 d−1 (Huang 3-D model) and 9.2±0.7 kg NH3 d−1 (Gaussian-3D model). These estimates were 94% and 63% of what was obtained using emission factors from the German national inventory (9.6 kg d−1 NH3). The effect of deposition was evaluated with the FIDES-2D model. This increased the emission estimate to 11.7 kg NH3 d−1, showing that deposition can explain the observed difference. The daily pattern of the source was correlated with net radiation and with the temperature inside the animal houses. The daily pattern resulted from a combination of a temperature effect on the source concentration together with an effect of variations in free and forced convection of the building ventilation rate. Further development of the plume technique is especially relevant for naturally ventilated farms, since the variable ventilation rate makes other emission measurements difficult. [abstract from: http://www.biogeosciences.net/6/2847/2009/bg-6-2847-2009.html