Glutathione treatment protects the rat liver against injury after warm ischemia and Kupffer cell activation

Background/Aim: The generation of reactive oxygen species by activated Kupffer cells (KC) may contribute to reperfusion injury of the liver during liver transplantation or resection. The aim of our present studies was to investigate (1) prevention of hepatic reperfusion injury after warm ischemia by administration of the antioxidant glutathione (GSH) and (2) whether GSH confers protection through influences on KC toxicity. Methods: Isolated perfused rat livers were subjected to 1 h of warm ischemia followed by 90 min of reperfusion without (n = 5) or with GSH or catalase (n = 4-5 each). Selective KC activation by zymosan (150 mug/ml) in continuously perfused rat livers was used to investigate KC-related liver injury. Results: Postischemic infusion of 0.1, 0.5, 1.0 and 2.0 mM GSH, but not 0.05 mM GSH prevented reperfusion injury after warm ischemia as indicated by a marked reduction of sinusoidal LDH efflux by up to 83 +/- 13% (mean +/- SD; p < 0.05) and a concomitant significant improvement of postischemic bile flow by 58 +/- 27% (p < 0.05). A similar protection was conveyed by KC blockade with gadolinium chloride indicating prevention of KC-related reperfusion injury by postischemic GSH treatment. Postischemic treatment with catalase (150 U/ml) resulted in a reduction of LDH efflux by 40 +/- 9% (p < 0.05). Accordingly, catalase as well as GSH (0.1-2.0 mM) nearly completely prevented the increase in LDH efflux following selective :KC activation by zymosan in continously perfused rat livers. Conclusion: Postischemic administration of GSH protects the liver against reperfusion injury after warm ischemia. Detoxification of KC-derived hydrogen peroxide seem to be an important feature of the protective mechanisms. Copyright (C) 2002 S. Karger AG, Basel

Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter

The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8 +- 0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the \gamma-spectrum following the \alpha-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.Comment: 32 pages, 8 figures, eq. (3) correcte

A proteinaceous organic matrix regulates carbonate mineral production in the marine teleost intestine

Marine teleost fish produce CaCO(3) in their intestine as part of their osmoregulatory strategy. This precipitation is critical for rehydration and survival of the largest vertebrate group on earth, yet the molecular mechanisms that regulate this reaction are unknown. Here, we isolate and characterize an organic matrix associated with the intestinal precipitates produced by Gulf toadfish (Opsanus beta). Toadfish precipitates were purified using two different methods, and the associated organic matrix was extracted. Greater than 150 proteins were identified in the isolated matrix by mass spectrometry and subsequent database searching using an O. beta transcriptomic sequence library produced here. Many of the identified proteins were enriched in the matrix compared to the intestinal fluid, and three showed no substantial homology to any previously characterized protein in the NCBI database. To test the functionality of the isolated matrix, a micro-modified in vitro calcification assay was designed, which revealed that low concentrations of isolated matrix substantially promoted CaCO(3) production, where high concentrations showed an inhibitory effect. High concentrations of matrix also decreased the incorporation of magnesium into the forming mineral, potentially providing an explanation for the variability in magnesium content observed in precipitates produced by different fish species

Apportionment of primary and secondary organic aerosols in Southern California during the 2005 Study of Organic Aerosols in Riverside (SOAR-1)

Ambient sampling was conducted in Riverside, California during the 2005 Study of Organic Aerosols in Riverside to characterize the composition and sources of organic aerosol using a variety of state-of-the-art instrumentation and source apportionment techniques. The secondary organic aerosol (SOA) mass is estimated by elemental carbon and carbon monoxide tracer methods, water soluble organic carbon content, chemical mass balance of organic molecular markers, and positive matrix factorization of high-resolution aerosol mass spectrometer data. Estimates obtained from each of these methods indicate that the organic fraction in ambient aerosol is overwhelmingly secondary in nature during a period of several weeks with moderate ozone concentrations and that SOA is the single largest component of PM1 aerosol in Riverside. Average SOA/OA contributions of 70−90% were observed during midday periods, whereas minimum SOA contributions of ~45% were observed during peak morning traffic periods. These results are contrary to previous estimates of SOA throughout the Los Angeles Basin which reported that, other than during severe photochemical smog episodes, SOA was lower than primary OA. Possible reasons for these differences are discussed

The alpha subunit of RNA polymerase and transcription antitermination

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72225/1/j.1365-2958.1996.451409.x.pd

An Evolutionary Cancer Epigenetic Approach Revealed DNA Hypermethylation of Ultra-Conserved Non-Coding Elements in Squamous Cell Carcinoma of Different Mammalian Species

BACKGROUND: Ultra-conserved non-coding elements (UCNEs) are genomic sequences that exhibit &gt; 95% sequence identity between humans, mammals, birds, reptiles, and fish. Recent findings reported their functional role in cancer. The aim of this study was to evaluate the DNA methylation modifications of UNCEs in squamous cell carcinoma (SCC) from different mammal species. METHODS: Fifty SCCs from 26 humans, 17 cats, 3 dogs, 1 horse, 1 bovine, 1 badger, and 1 porcupine were investigated. Fourteen feline stomatitis and normal samples from 36 healthy human donors, 7 cats, 5 dogs, 5 horses, 2 bovines and 1 badger were collected as normal controls. Bisulfite next generation sequencing evaluated the DNA methylation level from seven UCNEs (uc.160, uc.283, uc.416, uc.339, uc.270, uc.299, and uc.328). RESULTS: 57/59 CpGs were significantly different according to the Kruskal-Wallis test (p &lt; 0.05) comparing normal samples with SCC. A common DNA hypermethylation pattern was observed in SCCs from all the species evaluated in this study, with an increasing trend of hypermethylation starting from normal mucosa, through stomatitis to SCC. CONCLUSIONS: Our findings indicate that UCNEs are hypermethylated in human SCC, and this behavior is also conserved among different species of mammals

A regional scale modeling analysis of aerosol and trace gas distributions over the eastern Pacific during the INTEX-B field campaign

The Sulfur Transport and dEposition Model (STEM) is applied to the analysis of observations obtained during the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B), conducted over the eastern Pacific Ocean during spring 2006. Predicted trace gas and aerosol distributions over the Pacific are presented and discussed in terms of transport and source region contributions. Trace species distributions show a strong west (high) to east (low) gradient, with the bulk of the pollutant transport over the central Pacific occurring between similar to 20 degrees N and 50 degrees N in the 2-6 km altitude range. These distributions are evaluated in the eastern Pacific by comparison with the NASA DC-8 and NSF/NCAR C-130 airborne measurements along with observations from the Mt. Bachelor (MBO) surface site. Thirty different meteorological, trace gas and aerosol parameters are compared. In general the meteorological fields are better predicted than gas phase species, which in turn are better predicted than aerosol quantities. PAN is found to be significantly overpredicted over the eastern Pacific, which is attributed to uncertainties in the chemical reaction mechanisms used in current atmospheric chemistry models in general and to the specifically high PAN production in the SAPRC-99 mechanism used in the regional model. A systematic underprediction of the elevated sulfate layer in the eastern Pacific observed by the C-130 is another issue that is identified and discussed. Results from source region tagged CO simulations are used to estimate how the different source regions around the Pacific contribute to the trace gas species distributions. During this period the largest contributions were from China and from fires in South/Southeast and North Asia. For the C-130 flights, which operated off the coast of the Northwest US, the regional CO contributions range as follows: China (35%), South/Southeast Asia fires (35%), North America anthropogenic (20%), and North Asia fires (10%). The transport of pollution into the western US is studied at MBO and a variety of events with elevated Asian dust, and periods with contributions from China and fires from both Asia and North America are discussed. The role of heterogeneous chemistry on the composition over the eastern Pacific is also studied. The impacts of heterogeneous reactions at specific times can be significant, increasing sulfate and nitrate aerosol production and reducing gas phase nitric acid levels appreciably (~50%)

Low expression of the putative tumour suppressor spinophilin is associated with higher proliferative activity and poor prognosis in patients with hepatocellular carcinoma

BACKGROUND: Spinophilin, a multifunctional intracellular scaffold protein, is reduced in certain types of cancer and is regarded as a novel putative tumour suppressor protein. However, the role of spinophilin in hepatocellular carcinoma (HCC) has never been explored before. METHODS: In this study, we determined for the first time the expression pattern of spinophilin in human HCC by immunohistochemistry and quantitative reverse transcriptase–PCR analysis. In addition, we performed immunohistochemical analysis of p53, p14(ARF) and the proliferation marker Ki-67. Kaplan–Meier curves and multivariate Cox proportional models were used to study the impact on clinical outcome. Small interfering RNA (siRNA) was used to silence spinophilin and to explore the effects of reduced spinophilin expression on cellular growth. RESULTS: In our study, complete loss of spinophilin immunoreactivity was found in 44 of 104 HCCs (42.3%) and reduced levels were found in an additional 37 (35.6%) cases. After adjusting for other prognostic factors, multivariate Cox regression analysis identified low expression of spinophilin as an independent prognostic factor with respect to disease-free (hazard ratio (HR)=1.8; 95% confidence interval (CI)=1.04–3.40; P=0.043) and cancer-specific survival (HR=2.0; CI=1.1–3.8; P=0.025). Reduced spinophilin expression significantly correlated with higher Ki-67 index in HCC (P=0.014). Reducing spinophilin levels by siRNA induced a higher cellular growth rate and increased cyclin D2 expression in tumour cells (P<0.05). CONCLUSION: This is the first study of the expression pattern and distribution of spinophilin in HCC. According to our data, the loss of spinophilin is associated with higher proliferation and might be useful as a prognostic marker in patients with HCC