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1.
Lipid composition was studied on cerebral tissue from nine children who had died of a progressive encephalopathy called the infantile form of neuronal ceroid lipofuscinosis (INCL) or polyunsaturated fatty acid lipidosis (PFAL). In the terminal stage of the disease, the concentrations of all lipid classes were found to be significantly reduced in the cerebral and cerebellar cortex and white matter. The concentration of gangliosides of the cerebral cortex was 15% and that of cerebrosides (galactosylceramide) in white matter 0.2-5% of the normal values for the children's ages. The reduction of gangliosides mainly affected those of the gangliotetraose series, particularly GD1a. The fatty acids of the linolenic acid series were strongly reduced in ethanolamine and serine phosphoglycerides. A very large increase up to 100-fold of oligoglycosphingolipids of the globo series and two fucose-containing lipids of the neolacto series was found in the forebrain of the three advanced cases examined. The brain tissue also contained very high concentrations of mono-, di-, and trisialogangliosides of the lacto and neolacto series, gangliosides with type 1 chain dominating. The structures of the gangliosides were tentatively identified by gas chromatography-mass spectrometry and monoclonal antibodies with carefully determined epitope specificity. The gangliosides and neutral glycosphingolipids had very similar fatty acid composition, consisting of about 40% stearic acid and 40% C24-acids.  相似文献   
2.
Adenovirus type 5 (Ad5) host range mutants dl312 and hr-1, with lesions in region E1A (0 to 4.5 map units) of the viral genome, fail to accumulate virus-specific early RNA during infection in HeLa cells. In a recent report, we showed that the addition of anisomycin, a stringent inhibitor of protein synthesis, at 1 h after infection of HeLa cells with hr-1 virus resulted in the accumulation of properly spliced and translatable mRNA from all early regions (M. G. Katze, H. Persson, and L. Philipson, Mol. Cell. Biol. 1:807-813, 1981). Based on these results we proposed a model in which expression of early mutant RNA was achieved through inactivation of a cellular protein normally causing a reduction in the amount of viral RNA. These studies have been extended in the present report, which shows that early viral proteins can be detected in Ad5 dl312- and Ad5 hr-1-infected HeLa cells which have been treated for several hours with anisomycin either shortly after infection or before infection. A pulse of drug treatment also resulted in expression of substantial amounts of adenovirus structural proteins after infection with both Ad5 hr-1 and Ad5 dl312, whereas in drug-free controls no late proteins were detected. The Ad5 hr-1 virus previously reported to be DNA replication negative in nonpermissive HeLa cells was found to replicate its DNA, albeit at low levels, when anisomycin was present either from 1 to 5 h postinfection or for 5 h before infection. When infectious virus production was examined in mutant-infected cells the titer of Ad5 dl312 virus was found to increase at least 500-fold in anisomycin-treated HeLa cells. Taken together, these and our previous results suggest that the block in gene expression characteristic for complementation group I Ad5 host range mutants in HeLa cells can be overcome by inactivating cellular gene products serving as negative regulators of viral gene expression.  相似文献   
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The iron-containing B2 subunit of ribonucleotide reductase from Escherichia coli has been investigated by Raman spectroscopy. Both the tyrosyl radical-containing native protein and the radical-free protein exhibit a resonance-enhanced Raman band at 500 cm?1. This band is assigned to an Fe-O vibrational mode arising from an oxygen-containing ligand. The failure to observe any tyrosinate ring modes makes it unlikely that ribonucleotide reductase is an iron-tyrosinate protein and rules out tyrosinate oxygen as a ligand. It is proposed that the 500 cm?1 band in ribonucleotide reductase is analogous to the 510 cm?1 Fe-O vibrational mode of methemerythrin and arises from an oxo- or carboxylate-bridge between the antiferromagnetically-coupled Fe(III) ions.  相似文献   
5.

Background

Little is known about the management of patients suffering from chronic obstructive pulmonary disease (COPD) during the last years of life. The aim of the study was to describe how management of COPD is performed in Sweden during the last two years of life.

Methods

From the nationwide Cause of Death register all individuals with COPD as the underlying cause of death during two years were identified in one sparsely and one densely populated area of Sweden. Data were collected from medical records using a pre-defined protocol, especially developed for this purpose.

Results

Of 822 individuals with COPD as underlying cause of death, medical records from 729 were available. The COPD diagnosis was based on lung function measurements in approximately half of the patients and median age at COPD diagnosis was 74 years (range 34-95). Women died at younger age, median 78 years (range 52-96) than did men (80 years (51-99)). The median survival time from diagnosis to death was 6 years in men and women in both areas. Among women and men 8.3% and 4.3% were never smokers, respectively. The structure of COPD management differed between the two areas, with utilization of physiotherapists, dieticians and working therapists being more used in the northern area, likely because of differences in accessibility to care institutions.

Conclusions

In Sweden COPD is mostly diagnosed late in life and often not verified by lung function measurements. Opposite to the general population, women with COPD die at a lower age than men.  相似文献   
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Assessments of bacterial community diversity and dynamics are fundamental for the understanding of microbial ecology as well as biotechnological applications. We show that the choice of PCR primers has great impact on the results of analyses of diversity and dynamics using gene libraries and DNA fingerprinting. Two universal primer pairs targeting the 16S rRNA gene, 27F&1492R and 63F&M1387R, were compared and evaluated by analyzing the bacterial community in the activated sludge of a large-scale wastewater treatment plant. The two primer pairs targeted distinct parts of the bacterial community, none encompassing the other, both with similar richness. Had only one primer pair been used, very different conclusions had been drawn regarding dominant phylogenetic and putative functional groups. With 27F&1492R, Betaproteobacteria would have been determined to be the dominating taxa while 63F&M1387R would have described Alphaproteobacteria as the most common taxa. Microscopy and fluorescence in situ hybridization analysis showed that both Alphaproteobacteria and Betaproteobacteria were abundant in the activated sludge, confirming that the two primer pairs target two different fractions of the bacterial community. Furthermore, terminal restriction fragment polymorphism analyses of a series of four activated sludge samples showed that the two primer pairs would have resulted in different conclusions about community stability and the factors contributing to changes in community composition. In conclusion, different PCR primer pairs, although considered universal, target different ranges of bacteria and will thus show the diversity and dynamics of different fractions of the bacterial community in the analyzed sample. We also show that while a database search can serve as an indicator of how universal a primer pair is, an experimental assessment is necessary to evaluate the suitability for a specific environmental sample.  相似文献   
8.
Cytomegalovirus (CMV) has been suggested as a contributing force behind the impaired immune responsiveness in the elderly, with decreased numbers of naïve T-cells and an increased proportion of effector T-cells. Immunological impairment is also implicated as a part of the pathogenesis in Alzheimer’s disease (AD). The aim of this study was to investigate whether AD patients present with a different CMV-specific CD8 immune profile compared to non-demented controls. Blood samples from 50 AD patients and 50 age-matched controls were analysed for HLA-type, CMV serostatus and systemic inflammatory biomarkers. Using multi-colour flow cytometry, lymphocytes from peripheral blood mononuclear cells were analysed for CMV-specific CD8 immunity with MHC-I tetramers A01, A02, A24, B07, B08 and B35 and further classified using CD27, CD28, CD45RA and CCR7 antibodies. Among CMV seropositive subjects, patients with AD had significantly lower proportions of CMV-specific CD8 T-cells compared to controls, 1.16 % vs. 4.13 % (p=0.0057). Regardless of dementia status, CMV seropositive subjects presented with a lower proportion of naïve CD8 cells and a higher proportion of effector CD8 cells compared to seronegative subjects. Interestingly, patients with AD showed a decreased proportion of CMV-specific CD8 cells but no difference in general CD8 differentiation.  相似文献   
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Assessments of climate change impacts on forests and their vitality are essential for semi-arid environments such as Central Asia, where the mountain regions belong to the globally important biodiversity hotspots. Alterations in species distribution or drought-induced tree mortality might not only result in a loss of biodiversity but also in a loss of other ecosystem services. Here, we evaluate spatial trends and patterns of the growth-climate relationship in a tree-ring network comprising 33 juniper sites from the northern Pamir-Alay and Tien Shan mountain ranges in eastern Uzbekistan and across Kyrgyzstan for the common period 1935–2011. Junipers growing at lower elevations are sensitive to summer drought, which has increased in intensity during the studied period. At higher elevations, juniper growth, previously favored by warm summer temperatures, has in the recent few decades become negatively affected by increasing summer aridity. Moreover, response shifts are observed during all seasons. Rising temperatures and alterations in precipitation patterns during the past eight decades can account for the observed increase in drought stress of junipers at all altitudes. The implications of our findings are vital for the application of adequate long-term measures of ecosystem conservation, but also for paleo-climatic approaches and coupled climate-vegetation model simulations for Central Asia.  相似文献   
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