8,607 research outputs found
Epstein-Barr-Virus - Ein klinisch relevanter Marker fĂĽr das Nasopharynxkarzinom? = Epstein-Barr virus - a clinically relevant feature of nasopharyngeal carcinoma? (author's transl.)
Nasopharyngeal carcinoma (NPC) has been linked to Epstein-Barr Virus (EBV) by seroepidemiological evidence and by the regular proof of EBV-DNA in the epithelial tumor cells. We have been able to study the serological parameters of 62 NPC patients of the local ENT-Clinic. All patients were kaukasians in contrast to a previous study by Henle et al. Our results emphasize the remarkable predominance of EBV-IgA antibodies to viral capsid antigen (VCA) and early antigen (EA) in NPC patients and prove the value of the test for the initial diagnosis of the disease. Follow-up studies with subsequent serological tests strongly suggest that this test is related to the stage of the disease. We have also found NPC-typical serological EBV-IgA titers in 3 lymphoepithelial carcinomas of the tonsil and the soft palate. Similar titers have been found in two cases of poorly differentiated carcinomas of the base of the tongue. All these tumors arise in the lymphoepithelial tissue of Waldeyer's ring. We conclude that possibly some carcinomas of Waldeyer's ring are similarly related to EBV as nasopharyngeal carcinomas are
The heats of combustion of some rare-earth metals
A bomb calorimeter for measuring the heats of combustion of neodymium, samarium, gadolinium and erbium is described. The heats of combustion of these metals and the heats of formation of their oxides are reported
Microbial Decontamination and Weight of Carcass Beef as Affected by Automated Washing Pressure and Length of Time of Spray
Carcass beef has traditionally been washed by hand to remove foreign material such as hair, soil particles, and microbiological organisms that have contaminated the surfaces. These carcasses are inspected by the Food Safety Inspection Service (FSIS)to detect defects related to carcass cleanliness. Recent research and development of technology have emphasized automated machine washing.
At pressures above that normally used, it is conceivable that water could penetrate tissue surfaces and be absorbed by the carcasses. Also, longer wash periods may enhance water uptake by carcasses. According to the ASH RAE Handbook and Product Directory, the average shrinkage of carcass beef using good current practices was 1.3% at 20 hr postmortem. USDA meat inspection regulations required that carcasses sustain no net increase in weight due to absorption of water during the washing process. There is no available literature on the effects of various automated washing techniques on carcass weights after a 20-hr chill.
The objectives of the study reported presently were to determine the effects of nozzle pressure and length of time washed on the microflora and weights of carcass beef at 20 hr postmortem
Evidence for a Soft Nuclear Equation-of-State from Kaon Production in Heavy Ion Collisions
The production of pions and kaons has been measured in Au+Au collisions at
beam energies from 0.6 to 1.5 AGeV with the Kaon Spectrometer at SIS/GSI. The
K+ meson multiplicity per nucleon is enhanced in Au+Au collisions by factors up
to 6 relative to C+C reactions whereas the corresponding pion ratio is reduced.
The ratio of the K+ meson excitation functions for Au+Au and C+C collisions
increases with decreasing beam energy. This behavior is expected for a soft
nuclear equation-of-state.Comment: 14 pages, 2 figures, accepted for publication in Phys. Rev. Let
Production of Charged Pions, Kaons and Antikaons in Relativistic C+C and C+Au Collisions
Production cross sections of charged pions, kaons and antikaons have been
measured in C+C and C+Au collisions at beam energies of 1.0 and 1.8 AGeV for
different polar emission angles. The kaon and antikaon energy spectra can be
described by Boltzmann distributions whereas the pion spectra exhibit an
additional enhancement at low energies. The pion multiplicity per participating
nucleon M(pi+)/A_part is a factor of about 3 smaller in C+Au than in C+C
collisions at 1.0 AGeV whereas it differs only little for the C and the Au
target at a beam energy of 1.8 AGeV. The K+ multiplicities per participating
nucleon M(K+)/A_part are independent of the target size at 1 AGeV and at 1.8
AGeV. The K- multiplicity per participating nucleon M(K-)/A_part is reduced by
a factor of about 2 in C+Au as compared to C+C collisions at 1.8 AGeV. This
effect might be caused by the absorption of antikaons in the heavy target
nucleus. Transport model calculations underestimate the K-/K+ ratio for C+C
collisions at 1.8 AGeV by a factor of about 4 if in-medium modifications of K
mesons are neglected.Comment: 19 pages, 14 figures, accepted for publication in Eur. Phys. J.
Kaon and Antikaon Production in Heavy Ion Collisions at 1.5 AGeV
At the Kaon Spectrometer KaoS at SIS, GSI the production of kaons and
antikaons in heavy ion reactions at a beam energy of 1.5 AGeV has been measured
for the collision systems Ni+Ni and Au+Au. The K-/K+ ratio is found to be
constant for both systems and as a function of impact parameter but the slopes
of K+ and K- spectra differ for all impact parameters. Furthermore the
respective polar angle distributions will be presented as a function of
centrality.Comment: 4 pages, 4 figures, SQM2001 in Frankfurt, Sept.2001, submitted to
Journal of Physics
K+ and K- production in heavy-ion collisions at SIS-energies
The production and the propagation of K+ and of K- mesons in heavy-ion
collisions at beam energies of 1 to 2 AGeV have systematically been
investigated with the Kaon Spectrometer KaoS at the SIS at the GSI. The ratio
of the K+ production excitation function for Au+Au and for C+C reactions
increases with decreasing beam energy, which is expected for a soft nuclear
equation-of-state. At 1.5 AGeV a comprehensive study of the K+ and of the K-
emission as a function of the size of the collision system, of the collision
centrality, of the kaon energy, and of the polar emission angle has been
performed. The K-/K+ ratio is found to be nearly constant as a function of the
collision centrality. The spectral slopes and the polar emission patterns are
different for K- and for K+. These observations indicate that K+ mesons
decouple earlier from the reaction zone than K- mesons.Comment: invited talk given at the SQM2003 conference in Atlantic Beach, USA
(March 2003), to be published in Journal of Physics G, 10pages, 7 figure
Bim and Bmf synergize to induce apoptosis in Neisseria gonorrhoeae infection
Abstract: Bcl-2 family proteins including the pro-apoptotic BH3-only proteins are central regulators of apoptotic cell death. Here we show by a focused siRNA miniscreen that the synergistic action of the BH3-only proteins Bim and Bmf is required for apoptosis induced by infection with Neisseria gonorrhoeae (Ngo). While Bim and Bmf were associated with the cytoskeleton of healthy cells, they both were released upon Ngo infection. Loss of Bim and Bmf from the cytoskeleton fraction required the activation of Jun-N-terminal kinase-1 (JNK-1), which in turn depended on Rac-1. Depletion and inhibition of Rac-1, JNK-1, Bim, or Bmf prevented the activation of Bak and Bax and the subsequent activation of caspases. Apoptosis could be reconstituted in Bim-depleted and Bmf-depleted cells by additional silencing of antiapoptotic Mcl-1 and Bcl-XL, respectively. Our data indicate a synergistic role for both cytoskeletal-associated BH3-only proteins, Bim, and Bmf, in an apoptotic pathway leading to the clearance of Ngo-infected cells. Author Summary: A variety of physiological death signals, as well as pathological insults, trigger apoptosis, a genetically programmed form of cell death. Pathogens often induce host cell apoptosis to establish a successful infection. Neisseria gonorrhoeae (Ngo), the etiological agent of the sexually transmitted disease gonorrhoea, is a highly adapted obligate human-specific pathogen and has been shown to induce apoptosis in infected cells. Here we unveil the molecular mechanisms leading to apoptosis of infected cells. We show that Ngo-mediated apoptosis requires a special subset of proapoptotic proteins from the group of BH3-only proteins. BH3-only proteins act as stress sensors to translate toxic environmental signals to the initiation of apoptosis. In a siRNA-based miniscreen, we found Bim and Bmf, BH3-only proteins associated with the cytoskeleton, necessary to induce host cell apoptosis upon infection. Bim and Bmf inactivated different inhibitors of apoptosis and thereby induced cell death in response to infection. Our data unveil a novel pathway of infection-induced apoptosis that enhances our understanding of the mechanism by which BH3-only proteins control apoptotic cell death
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