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991.
Summary We have characterized the ribosomal proteins from Spinacia chloroplasts using two-dimensional gel electrophoresis. The 30S and 50S subunits contain 23–25 and 36 ribosomal proteins, respectively. In contrast to prokaryotic ribosomes, chloroplast ribosomes contain at least one (and possibly two) phosphorylated ribosomal proteins. Isolated chloroplasts synthesize in the presence of (35S) labeled methionine and cysteine at least seven 30S and thirteen 50S ribosomal proteins which are assembled into (pre)ribosomes. This suggests that about one third of the chloroplast ribosomal proteins is encoded by the chloroplast DNA itself. The identity of several labeled proteins in the two-dimensional gel electrophoretic patterns which did not comigrate with stained chloroplast ribosomal proteins is discussed.Abbreviations CBB
Coomassie Brilliant Blue
- CHI
cycloheximide
- cp
chloroplast
- DTT
dithiotreitol
- EDTA
ethylene diamine tetraacetate
- EGTA
ethylene glycol-bis (-amino ethyl ether) N,N-tetraacetic acid
- kD
kilodalton
- LHCP
light harvesting chlorophyll a/b protein
- PMSF
phenyl methyl sulfonyl fluoride
- RuBPCase
ribulose-1,5-bisphosphate carboxylase
- SDS
sodiumdodecylsulphate 相似文献
992.
993.
van den Hurk AF Cooper RD Beebe NW Williams GM Bryan JH Ritchie SA 《Journal of medical entomology》2000,37(1):153-161
In the Cairns area of far north Queensland, Australia, the seasonal abundance of Anopheles farauti Laveran sibling species was studied at 6 locations, representing 3 habitat types, between August 1995 and September 1997. A total of 45,401 An. farauti s.l. was collected using CO2 + octenol baited CDC light traps, and consisted of 29,565 An. farauti No. 2, 14,214 An. farauti No. 3, and 1,622 An. farauti s.s. The relative abundance of all 3 species differed significantly by season and location. An. farauti No.2 was the dominant species except in Cairns, where An. farauti s.s. was most abundant, and at Ninds Creek, where An. farauti No. 3 predominated. The dominant species at each location was present year round, although peaks in seasonal abundance were observed. An. farauti s.s. populations were highest during the wet season (January-April). In lowland freshwater swamp habitats and 1 brackish location, An. farauti No. 2 was more abundant during the wet season. However, at the highland freshwater swamp habitat, populations of An. farauti No. 2 were highest during the late dry season and early wet season (October-December). There was a significant positive correlation of both temperature and rainfall with An. farauti s.s. and An. farauti No. 2 trap collections. There was a negative correlation between An. farauti No. 3 and temperature, indicating that this species may be more abundant during cool weather. Although there were significant relationships among weather variables and An. farauti s.l. collections, correlation values were generally low, indicating that other factors may contribute to variability among An. farauti sibling species trap collections. 相似文献
994.
Severe intrauterine growth retardation,blepharophimosis, and cylindrical nose with midline groove: a new syndrome?
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A malformed female infant is described. In addition to cardiac, renal, and skeletal (rib) anomalies, severe intrauterine growth retardation and distinct facial dysmorphism were present. The question is raised whether this child represents a new syndrome. 相似文献
995.
Role of interleukin 1 in antigen-induced exacerbations of murine arthritis. 总被引:4,自引:1,他引:4
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A. A. van de Loo O. J. Arntz A. C. Bakker P. L. van Lent M. J. Jacobs W. B. van den Berg 《The American journal of pathology》1995,146(1):239-249
The mechanism underlying the chronic and intermittent course of rheumatoid arthritis is not elucidated. In the present study, the role of interleukin 1 (IL-1) was investigated in exacerbations of antigen-induced arthritis in mice. A flare-up of smoldering inflammation (weeks 3 to 4 of antigen-induced arthritis) was inducible by injection of a small amount of methylated bovine serum albumin into the hypersensitive knee joint. Immunohistochemistry showed IL-1 expression in the synovial lining layer and in focal areas of the inflamed synovium during the flare-up. IL-1 was also measured in 1-hour culture supernatant of synovial tissue taken during the flare-up by a bioassay. The expression of both immunoreactive and bioactive IL-1 in the hypersensitive joint peaked around 6 hours after antigen (2 micrograms of methylated bovine serum albumin) injection and declined thereafter. Antigen rechallenge induced an acute joint swelling of the arthritic joint but not in the naive joint of the sensitized mouse, yet synovia of both joints produced IL-1 after antigen injection. Remarkably, a single intravenous injection of rabbit anti-IL-1 alpha and -beta antibodies 1 hour before antigen rechallenge neutralized IL-1 in the joint. Anti-IL-1 treatment significantly reduced the antigen-induced joint swelling (30 to 40%) but did not affect the profound influx of polymorphonuclear cells in the onset of the exacerbation. However, a profound relief of the inflammation (synovitis) was obtained by IL-1 blockade on day 4 of the exacerbation. Chondrocyte proteoglycan synthesis was markedly suppressed in the antigen-challenged naive knee joints suggesting that this was a direct IL-1 effect as the inflammation was insignificant. Anti-IL-1 treatment was able to maintain chondrocyte proteoglycan synthesis in the antigen-rechallenged joint, which was highly suppressed in the control group. Furthermore, the enhanced proteoglycan breakdown in the antigen-rechallenged joints was significantly decreased in the anti-IL-1 group. We concluded that IL-1 is an important mediator in exacerbations of murine arthritis, and amelioration of cartilage pathology was obtained with anti-IL-1 antibody treatment. 相似文献
996.
Food-initiated outbreak of methicillin-resistant Staphylococcus aureus analyzed by pheno- and genotyping. 总被引:3,自引:4,他引:3
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![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J Kluytmans W van Leeuwen W Goessens R Hollis S Messer L Herwaldt H Bruining M Heck J Rost N van Leeuwen 《Journal of clinical microbiology》1995,33(5):1121-1128
An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) involving 27 patients and 14 health-care workers (HCW) was studied. The outbreak started in the hematology unit of the University Hospital Rotterdam, Dijkzigt, The Netherlands, and spread to the surgical unit. Twenty-one patients (77.8%) developed clinical disease, and five died. Subsequently, MRSA was detected in food and in the throat of one of the HCW who prepared food for hematology patients. Food contaminated by an HCW most likely caused the first case of MRSA septicemia. This route of transmission has not been described before. The outbreak strain was probably transmitted to the surgical unit by a colonized nurse, where it caused an explosive outbreak. Airborne probably transmitted to the surgical unit by a colonized nurse, where it caused an explosive outbreak. Airborne MRSA transmission played an important role in disseminating the organism. The outbreak was controlled within 6 months by intensifying surveillance, temporarily closing the affected wards, treating carriers, and instituting an MRSA ward outside the hospital. Phage typing, insertion sequence probing, protein A gene typing, and DNA fingerprinting by PCR revealed that all outbreak-related isolates were identical. By pulsed-field gel electrophoresis, all but one of the outbreak-related isolates were determined to be identical. Protein A gene typing identified numerous (11) repeat units in all outbreak-related isolates, which supports the suggestion that the outbreak strain may have been more virulent and more transmissible than other MRSA strains. Pheno- and genotyping studies underlined the value of DNA fingerprinting methods for investigation of MRSA epidemiology. Optimal discriminatory power was achieved by combining the results of four genotyping methods. 相似文献
997.
Z H Yang P E de Haas C H Wachmann D van Soolingen J D van Embden A B Andersen 《Journal of clinical microbiology》1995,33(8):2077-2081
The incidence of tuberculosis (TB) is increasing all over the world, including in countries with a high standard of living and good social security. Denmark represents such a region. Furthermore, it is a small country (5 million inhabitants) with a long tradition in TB control, including a centralization of the bacteriological diagnostic facility. The present study was intended to analyze the transmission of Mycobacterium tuberculosis in a country in which TB has low endemicity by a combination of conventional epidemiological approaches and DNA fingerprinting techniques, whereby individual bacterial strains can be traced. M. tuberculosis isolates from 92% of all new cases of bacteriologically verified TB in Denmark during 1992 were subjected to IS6110 DNA fingerprinting to visualize the DNA restriction fragment length polymorphism (RFLP) patterns of the isolated strains. The data obtained from the RFLP analyses were interpreted by using demographic data, such as age, sex, ethnicity, and residence, for the patients. The risk factors among the patients for being part of an active chain of transmission, as opposed to demonstrating reactivation of a previously acquired latent infection, were estimated by statistical analyses. The magnitude of TB transmission in 1992 in Denmark was determined, and transmitted infections were shown to comprise at least one quarter of the total number of cases. Almost half of the TB cases involved patients of foreign origin. However, most of these isolates showed unique DNA fingerprint patterns and were rarely part of an active chain of transmission. The major chains of recent transmission were localized to distinct geographical regions in the country.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
998.
Functional defects in the fanconi anemia pathway in pancreatic cancer cells 总被引:17,自引:0,他引:17
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van der Heijden MS Brody JR Gallmeier E Cunningham SC Dezentje DA Shen D Hruban RH Kern SE 《The American journal of pathology》2004,165(2):651-657
Biallelic BRCA2-mutations can cause Fanconi anemia and are found in approximately 7% of pancreatic cancers. Recently, several sequence changes in FANCC and FANCG were reported in pancreatic cancer. Functional defects in the Fanconi pathway can result in a marked hypersensitivity to interstrand crosslinking agents, such as mitomycin C. The functional implications of mutations in the Fanconi pathway in cancer have not been fully studied yet; these studies are needed to pave the way for clinical trials of treatment with crosslinking agents of Fanconi-defective cancers. The competence of the proximal Fanconi pathway was screened in 21 pancreatic cancer cell lines by an assay of Fancd2 monoubiquitination using a Fancd2 immunoblot. The pancreatic cancer cell lines Hs766T and PL11 were defective in Fancd2 monoubiquitination. In PL11, this defect led to the identification of a large homozygous deletion in FANCC, the first cancer cell line found to be FANCC-null. The Fanconi-defective cell lines Hs766T, PL11, and CAPAN1 were hypersensitive to the crosslinking agent mitomycin C and some to cis-platin, as measured by cell survival assays and G(2)/M cell-cycle arrest. These results support the practical exploration of crosslinking agents for non-Fanconi anemia patients that have tumors defective in the Fanconi pathway. 相似文献
999.
1000.
Refractoriness to Gal N toxicity occurs especially in fetal rats, newborn rats, and in rats after partial hepatectomy. An injury however (laparotomy, incision on the back or ip BaSO4 suspension), prior to Gal N administration, also inhibits Gal N toxicity. In all these circumstances high levels of rat α2-macrofetoprotein (αMFP) occur. This protein is an acute phase reactant and is identical to rat α2-macroglobulin. αMFP isolated from the serum of injured rats and then administered to normal rats strongly inhibits Gal N toxicity. When time interval between the preceding injury, provoking αMFP production and Gal N administration shortens, the inhibiting effects are less and αMFP production remains low.During resistance to Gal N, the primary and secondary biochemical lesions of Gal N persist and the protecting effect of αMFP must be due to another mechanism, operating in later phases of cell injury. Very probably this is attributable to the stabilizing effect on membranes of hepatocytic organelles and the plasma membranes. As αMFP is an acute phase reactant the importance of these proteins to the course of hepatitis must be considered. 相似文献