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81.
13C NMR spectroscopic studies on polyanion-polycation complexes and their component polyelectrolytes
Joachim Ktz Andreas Ebert Jürgen Kunze Burkart Philipp Johan Lindberg Kari Soljamo 《Macromolecular chemistry and physics.》1990,191(3):651-658
Position and intensities of the 13C NMR signals and relaxation times T1 of several anionic and cationic polyelectrolytes in the solid state were compared with those of the appropriate polyanion-polycation complexes. At a high charge density of the components, the most significant changes of the parameters in question due to complex formation are observed for the C atoms adjacent to the charge centers, indicating a strong Coulombic interaction. At lower charge density, conformational changes of the polymer chains have also to be taken into consideration. 相似文献
82.
83.
Male rabbits were injured by a single mechanical dilatation injury of aorta and then injected with prednisone 2 mg/kg or saline for 14 days or subjected to starvation. The biosynthesis of the sulfated glycosaminoglycans as evaluated by the uptake of 35S-sulfate and the content of the glycosaminoglycans were measured on the intima-media layer of the descending thoracic aorta. The results indicate that prednisone may inhibit the biosynthesis of heparan and/or dermatan sulfate while starvation increases the biosynthesis of all the sulfated glycosaminoglycans. No alterations were observed in the total amount of glycosaminoglycans in aorta following glucocorticoid injection or starvation. The metabolism of aortic glycosaminoglycans during repair is less sensitive to the action of prednisone than in undamaged aorta. This contrasts with the effect of prednisone on the metabolism of aortic collagen. 相似文献
84.
Gabriella Lindgren Kaj Sandberg Helena Persson Stefan Marklund Matthew Breen Bjrn Sandgren Johan Carlstn Hans Ellegren 《Genome research》1998,8(9):951-966
A primary male autosomal linkage map of the domestic horse (Equus caballus) has been developed by segregation analysis of 140 genetic markers within eight half-sib families. The family material comprised four Standardbred trotters and four Icelandic horses, with a total of 263 offspring. The marker set included 121 microsatellite markers, eight protein polymorphisms, five RFLPs, three blood group polymorphisms, two PCR–RFLPs, and one single strand conformation polymorphism (SSCP). One hundred markers were arranged into 25 linkage groups, 22 of which could be assigned physically to 18 different chromosomes (ECA1, ECA2, ECA3, ECA4, ECA5, ECA6, ECA7, ECA9, ECA10, ECA11, ECA13, ECA15, ECA16, ECA18, ECA19, ECA21, ECA22, and ECA30). The average distance between linked markers was 12.6 cM and the longest linkage group measured 103 cM. The total map distance contained within linkage groups was 679 cM. If the distances covered outside the ends of linkage groups and by unlinked markers were included, it was estimated that the marker set covered at least 1500 cM, that is, at least 50% of the genome. A comparison of the relationship between genetic and physical distances in anchored linkage groups gave ratios of 0.5–0.8 cM per Mb of DNA. This would suggest that the total male recombinational distance in the horse is 2000 cM; this value is lower than that suggested by chiasma counts. The present map should provide an important framework for future genome mapping in the horse. 相似文献
85.
Molecular genetic analysis of familial early-onset Alzheimer's disease linked to chromosome 14q24.3 总被引:4,自引:2,他引:4
Cruts Marc; Backhovens Hubert; Wang Sheng-Yue; Van Gassen Geert; Theuns Jessie; De Jonghe Chris; Wehnert Anita; De Voecht Joke; De Winter Goedele; Cras Patrick; Bruyland Marc; Datson Nicole; Weissenbach Jean; Dunnen Johan T.den; Martin Jean-Jaques; Hendriks Lydia; Van Broeckhoven Christine 《Human molecular genetics》1995,4(12):2363-2371
Genetic linkage studies have indicated that chromosome 14q24.3harbours a major locus for early-onset (onset age <65 years)Alzheimer's disease (AD3). Positional cloning efforts have identifieda novel gene S182 or presenilin 1 as the AD3 gene. We have mappedS182 in the AD3 candidate region between D14S277 and D14S284defined by genetic linkage studies in the two chromosome 14linked, early-onset AD families AD/A and AD/B. We have shownthat S182 is expressed in lymphoblasts and have determined thecomplete cDNA in both brain and lymphoblasts by RT-PCR sequencing.S182 is alternatively spliced in both brain and lymphoblastswithin a putative phosphorylation site located 5' in the codingregion. We identified two novel mutations, Ile143Thr and Gly384Alalocated in, respectively, the second transmembrane domain andin the sixth hydrophilic loop of the putative transmembranestructure of S182. As families AD/A and AD/B have a very similarAD phenotype our observation of two mutations in functionallydifferent domains suggest that onset age and severity of ADmay not be very helpful predictors of the location of putativeS182 mutations. 相似文献
86.
Pierre-Paul van Bogaert Johan S. Vereecke Edward E. Carmeliet 《Pflügers Archiv : European journal of physiology》1978,375(1):45-52
- Cardiac Purkinje fibers exposed to alkaline solutions (pH 8 to 9.5) show an increase in rate of diastolic depolarization, eventually resulting in induction of spontaneous activity or an increase of the spontaneous firing rate.
- The voltage-clamp analysis of the transmembrane currents in pH 9–9.5 shows: i) a shift in the depolarizing direction of the activation (s∞) and time constants (τ s ) curve of the \(i_{{\text{K}}_{\text{2}} }\) current, ii) a small increase in the maximal value of the fully activated \(i_{{\text{K}}_{\text{2}} }\) current, iii) no significant change of background current in the pacemaker region of membrane potentials.
- The effect of NH4Cl was studied as a means to vary intracellular pH. In the presence of Tris buffer the addition of 5 mM NH4Cl resulted in i) a shift in the depolarizing direction and a decrease in slope of the activation curve of the \(i_{{\text{K}}_{\text{2}} }\) current, ii) a shift in the depolarizing direction of the time-constants curve together with an increase in the maximum value of τ s , iii) an increase in the maximum value of the fully activated \(i_{{\text{K}}_{\text{2}} }\) current and a depolarizing shift of the reversal potential, similar to the effect of addition of Kc. In the presence of CO2?HCO3 buffer the addition of NH4Cl had no significant effect on the kinetics of the \(i_{{\text{K}}_{\text{2}} }\) current. Since intracellular pH is only affected by NH4Cl in the presence of Tris buffer, the results suggest that intracellular alkalinization is responsible for the change in \(i_{{\text{K}}_{\text{2}} }\) kinetics.
- Based on the findings with NH4Cl it is suggested that perfusion with Tris buffered alkaline solutions not only affects net negative surface charges on the outside but also and to a larger extent increases negative surface charges on the inside of the cell membrane.
87.
Niels Lorenzen Ellen Lorenzen Katja Einer-Jensen Scott E LaPatra 《Developmental and comparative immunology》2002,26(2):173-179
It was recently reported that DNA vaccination of rainbow trout fingerlings against viral hemorrhagic septicaemia virus (VHSV) induced protection within 8 days after intramuscular injection of plasmid DNA. In order to analyse the specificity of this early immunity, fish were vaccinated with plasmid DNA encoding the VHSV or the infectious haematopoietic necrosis virus (IHNV) glycoprotein genes and later challenged with homologous or heterologous pathogens. Challenge experiments revealed that immunity established shortly after vaccination was cross-protective between the two viral pathogens whereas no increased survival was found upon challenge with bacterial pathogens. Within two months after vaccination, the cross-protection disappeared while the specific immunity to homologous virus remained high. The early immunity induced by the DNA vaccines thus appeared to involve short-lived non-specific anti-viral defence mechanisms. 相似文献
88.
Johan A. Maeland Lars Bevanger Randi Valsoe Lyng 《Clinical and Vaccine Immunology : CVI》2004,11(6):1035-1039
The majority of group B streptococcus (GBS) isolates express one or more of a family of surface-anchored proteins that vary by strain and that form ladder-like patterns on Western blotting due to large repeat units. These proteins, which are important as GBS serotype markers and as inducers of protective antibodies, include the alpha C (Cα) and R4 proteins and the recently described alpha-like protein 2 (Alp2), encoded by alp2, and Alp3, encoded by alp3. In this study, we examined antigenic determinants possessed by Alp2 and Alp3 by testing of antibodies raised in rabbits, mainly by using enzyme-linked immunosorbent assays (ELISA) and an ELISA absorption test. The results showed that Alp2 and Alp3 shared an antigenic determinant, which may be a unique immunological marker of the Alp variants of GBS proteins. Alp2, in addition, possessed an antigenic determinant which showed specificity for Alp2 and a third determinant which showed serological cross-reactivity with Cα. Alp3, in addition to the determinant common to Alp2 and Alp3, harbored an antigenic site which also was present in the R4 protein, whereas no Alp3-specific antigenic site was detected. These ELISA-based results were confirmed by Western blotting and a fluorescent-antibody test. The results are consistent with highly complex antigenic structures of the alpha-like proteins in a fashion which is in agreement with the recently described structural mosaicism of the alp2 and alp3 genes. The results are expected to influence GBS serotyping, immunoprotection studies, and GBS vaccine developments. 相似文献
89.
Anti-HIV effects of chloroquine: inhibition of viral particle glycosylation and synergism with protease inhibitors 总被引:2,自引:0,他引:2
Savarino A Lucia MB Rastrelli E Rutella S Golotta C Morra E Tamburrini E Perno CF Boelaert JR Sperber K Cauda R 《Journal of acquired immune deficiency syndromes (1999)》2004,35(3):223-232
OBJECTIVE: We tested the effects of chloroquine (CQ) on glycosylation of HIV particles and in combination with protease inhibitors (PIs) on HIV replication and on P-glycoprotein (P-gp)/multidrug resistance protein-1 (MRP1). DESIGN: CD4 cell lines were infected with laboratory strains and peripheral blood mononuclear cells were infected with primary isolates for evaluation of the anti-HIV effects. Peripheral blood lymphocytes were evaluated for of P-gp and MRP1 functions. METHODS: HIV replication was assessed by enzyme-linked immunosorbent assay. HIV glycosylation was measured by metabolic labeling of viral particles with [H] glucosamine. Synergism was tested using isobolograms. P-gp and MRP1 functions were assayed using rhodamine 123 (Rh123) and carboxyfluorescein (CF) efflux assays, respectively. RESULTS: CQ alone inhibited HIV replication and glycosylation in a dose-dependent manner. In combination with indinavir (IDV), ritonavir, or saquinavir (SQV), CQ had a synergistic effect at concentrations found in plasma of subjects receiving malaria prophylaxis. CQ decreased the 50% effective concentration of IDV in primary isolates from Africa and restored the response to IDV or SQV in 3 PI-resistant isolates. CQ increased the block of Rh123 and CF efflux activity exerted by PIs. CONCLUSION: The inhibitory effects of CQ on HIV glycosylation are associated with synergistic effects in combination with PIs. The CQ/PI combination exerts combined inhibitory effects on P-gp and MRP1 function. 相似文献
90.
Helin H Lundin M Lundin J Martikainen P Tammela T Helin H van der Kwast T Isola J 《Human pathology》2005,36(4):381-386
Gleason grading forms the basis of prognostic and therapeutic assessment in prostatic carcinoma despite its subjective nature and substantial interobserver variation. The accuracy of Gleason grading can be improved by the use of educational tools such as reference images. However, conventional microscopy images are of limited educational value because it is neither possible to view the sample at different magnifications nor to navigate into different areas of the specimen. This limitation can be overcome by the use of virtual microscopy, which allows viewing entire digitized microscope slides. We created an interactive Web site ( www.webmicroscope.net/gleason ) featuring a comprehensive set of prostatic needle biopsies as virtual slides, which can be viewed with a standard Web browser (Internet Explorer or Netscape). To evaluate the validity of Web-based virtual microscopy for Gleason grading, an experienced uropathologist (TK) scored a series of 62 biopsies from the original glass slides and 6 weeks later from virtual slides on the Web site using an ordinary desktop computer. The intraobserver agreement was excellent, with identical Gleason scores found in 48 of the 62 cases ( kappa = 0.73). The 14 remaining scores differed only by 1 point on the Gleason scale (2-10). The virtual slides were viewed by 2 other uropathologists (PM and HH), with interobserver kappa coefficients ranging from 0.55 to 0.62, which is within the range of previously reported studies using glass slides. The 3 uropathologists' Gleason scores were included as reference scores on the Web site, which now serves as a publicly open platform for self-testing and learning of Gleason grading. We conclude that Web-based virtual microscopy is a promising new tool for teaching and standardizing Gleason grading. 相似文献