Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Ograniczanie wyników
Czasopisma help
Lata help
Autorzy help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 385

Liczba wyników na stronie
first rewind previous Strona / 20 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  antibody
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 20 next fast forward last
EN
A simple method for stabilization of lyophilization or freezing/thawing sensitive enzyme-antibody conjugates is described. The method involves soaking of these reagents directly onto the placebo homoepathic sugar tablets followed by a brief air drying. This solid dry formulation is stable at elevated room temperature and is very convenient for storing or shipping small aliquots of these lyophilzation sensitive reagents.
EN
The rough mutants of Gram-negative bacteria are widely used to induce protective antisera but the nature of the target epitope for such antibodies is not precisely defined. Endotoxin is one of several antigens present on the surface of bacterial cells, which are able to elicit specific antibodies. We studied the specificity of antibodies produced against a conjugate of E. coli J5 endotoxin core oligosaccharide with tetanus toxoid. The use of chemically defined antigen for immunisation excludes the possibility of production of antibodies against other cell surface antigens. A comparison of this monospecific anti-endotoxin serum with antiserum against E. coli J5 whole cells was performed in order to distinguish the role that endotoxin core oligosaccharide plays in the interaction with humoral host defences from that of other potentially important Gram-negative bacterial surface antigens. The reactivity of both sera with smooth and rough lipopolysaccharides was determined in ELISA, immunoblotting and by flow cytometry. Both antisera reacted with similar specificity with most lipopolysaccharides of identical or related core type. Less distinct reactions with endotoxins of the antibacterial serum in comparison with the anti-conjugate serum were found in all serological tests. LPS of E. coli O100 that showed the strongest reactions with both sera was used to stimulate IL-6, TNFα and nitric oxide production by the J-774A.1 cell line. Both sera were used to inhibit that stimulation and no inhibitory effects of the examined sera in comparison with non-immune serum were observed.
EN
The postulated intramolecular signaling in immunoglobulins generated by antigen binding has been controversial for years. The high heterogeneity of immune complexes as signaling systems and the requirement of the immobilized antigen form for efficient triggering of effector activity is likely the reason for the lack of clarity. Here we present new evidence supporting the notion of intramolecular signaling, based on the use of supramolecular dyes that bind to signal-derived specific sites in immunoglobulins.
EN
Congenitally abnormal fibrinogens with impaired fibrin monomer polymerization have been described to contain single amino-acid substitutions localized in certain positions of the γ275-330peptide region. To evaluate the role of the amino-acid sequence in the vicinity of Arg 275 in fibrin monomer polymerization, the peptide fragment corresponding to γ268-282was synthesized and used to obtain peptide-specific antibodies. These antibodies, when purified immunochemically on the immobilized peptide, bound to the intact fibrinogen and fibrin monomers with the same binding affinity. However, they did not recognize the Y268-282epitopes on the denatured and reduced fibrinogen molecules. The lack of influence of antipeptide antibodies on fibrin monomer polymerization indicates that the γ268-282peptide is not directly involved in the structure of the polymerization site in the D domain of fibrinogen. It is suggested that substitution of Arg275either by His or Cys in abnormal fibrinogens results probably in conformational changes which disturb a proper orientation of the polymerization site and reduce its expression.
EN
The aim of these studies was to determine the performances of five commercial ELISA kits in the detection of BLV antibodies in serum samples. Different variants of ELI SA methods (indirect, blocking and double-well) were employed for these kits. Comparative investigations using 428 serum samples showed 418 consistent results (97.7%). Ten results (2.3%) proved to be inconsistent including 7 (1.6%) results which were totally different. The cause of these divergences in serological tests are discussed.
EN
The aim of this study was to evaluate the occurrence of antibodies to the bluetongue virus (BTV) in animals imported to Poland in 2008, the calves born to bluetongue positive cows and Polish-origin animals kept together with imported cattle. From January 1 to December 15, 2008, a total of 25,495 samples of sera was tested using the c-ELISA and direct ELISA. Out of the tested sera, 1,511 (5.92 %) were found to be positive for BTV. The majority of seropositive cattle were imported to Poland from Germany (987; 65.3%) and the Netherlands (290; 19.2%). Maternal antibodies were detected in 129 (8.5%) samples of sera taken from calves born to seropositive dams of German and Dutch origin. The high number of seroreagents was the result of bluetongue vaccination implemented in BTV-infected EU member States in 2008. In conclusion, it can be stated that surveillance studies should be continued to monitor the actual bluetongue status of Poland. However, an ELISA for the differentiation of infected and vaccinated animals should be introduced to laboratory practice to determine the number of BTV post-infected seropositive animals in the population of imported animals.
EN
Background. The strongest immunogen of the Rh system is the D antigen. It is found in several variants and categories, which makes it difficult to determine the correct RhD (Rh+) or RhD negative (Rh-) phenotype. Although only some of the varieties and types of this antigen are of clinical significance, it is important to determine the normal Rh phenotype in recipients and donors. The aim of this study was to determine the frequency of weak D antigen in a population of potential recipients. Material and methods. The study group consisted of selected blood recipients in whom weak expression of the D antigen or its antibody was detected. In order to estimate the expression of antigen D, the blood was analyzed in the laboratory of the Regional Center of Blood Donation and Blood Treatment in Lublin. Blood from 220 potential recipients (149 women and 71 men) were used in the conducted research. The clinical material from the Laboratory of Transfusion Serology at the Provincial Specialist Hospital in Biała Podlaska was also used. Results. The presence of a weak D was confirmed in 21 recipients. 4 cases of weak D were confirmed among recipients of blood transplant, while 17 cases among those who did not have blood transfusions. There were significant differences in the occurrence of the weak D in relation to the transfusion in both women (χ² = 18.34 df = 2, p = 0.0001) and men (χ² = 17.25) . Conclusions. The correct determination of the RhD+ or RhD- phenotype is important for pregnant women who should be subjected to immunoprophylaxis of maternal-fetal conflict when a weak D is detected. In order to avoid post-transfusion complications among recipients, it is necessary to choose serologically and phenotypically crossed-matched blood components.
PL
Wprowadzenie. Najsilniejszym immunogenem układu Rh jest antygen D. Może on występować w kilku wariantach i odmianach, co stanowi trudność w ustaleniu prawidłowego fenotypu RhD dodatni (Rh+) lub RhD ujemny (Rh-). Chociaż tylko niektóre z odmian i warianty tego antygenu mają znaczenie kliniczne, to jednak istotne jest oznaczenie prawidłowego fenotypu Rh u biorców i dawców. Celem pracy było określenie częstości występowania antygenu D słaby w populacji potencjalnych biorców. Materiał i metody. Grupę badaną stanowili wyselekcjonowani biorcy krwi, u których wykryto słabą ekspresję antygenu D lub jego przeciwciała. W celu oceny wielkości ekspresji antygenu D, krew analizowano w pracowni Regionalnego Centrum Krwiodawstwa i Krwiolecznictwa w Lublinie. W przeprowadzonych badaniach przeanalizowano 220 potencjalnych biorców (149 kobiet i 71 mężczyzn). Wykorzystano też materiał kliniczny pochodzący z laboratorium Serologii Transfuzjologicznej przy Wojewódzkim Szpitalu Specjalistycznym w Białej Podlaskiej. Wyniki. Obecność słabego antygenu D potwierdzono u 21 biorców. Biorcom, którym przetaczano krew, w 4 przypadkach potwierdzono antygen D słaby, natomiast tym, którym nie przetaczano krwi, 17 przypadków. Wykazano istotne różnice w występowaniu antygenu D słaby w zależności od transfuzji zarówno w grupie kobiet (χ² = 18,34 df = 2, p = 0,0001), jak i mężczyzn (χ² = 17,25) . Wnioski. Prawidłowe określenie fenotypu RhD+, RhD- jest istotne dla kobiet w ciąży, które w przypadku wykrycia antygenu D słaby powinny być poddawane immunoprofilaktyce konfliktu matczyno-płodowego. Chcąc uniknąć powikłań poprzetoczeniowych, biorcom należy dobierać zgodne serologicznie i fenotypowo składniki krwi.
EN
Background: Lyme disease is a multi-organ disease caused by spirochetes, Borrelia burgdorferi sensu lato, transmitted by Ixodes, with its clinical picture including involvement of the skin, joints, nervous system and heart. Laboratory diagnostic tests for Lyme disease are mainly based on the detection of anti-Borrelia burgdorferi antibodies by means of serological methods. Aim of the work: assessment of the level of antibodies against specific B. burgdorferi s.l. antigens in persons with suspected Lyme disease. Material and methods: the tested group consisted of 98 patients with suspected Lyme disease. During the first phase of the tests, anti-Borrelia burgdorferi IgM/IgG antibodies were marked using ELISA method, and positive and uncertain results were confirmed by Westernblot test (Wb). Results: anti-B. burgdorferi IgM/IgG antibodies were present in 60 patients (61.2%). IgM and IgG antibodies were detected as positive in 8 (8.1%) and 35 (35.7%) patients respectively. IgM and IgG were co-present in 6 persons (6.1%), including 2 persons (2%) with positive results in both classes. All patients with positive IgM (12 persons) had anti-OspC antibodies, and 2 patients had, in addition, anti-p31 antibodies. In patients with positive IgG the results were as follows: antibodies against antigen p17 - 77% of cases, VlsE - 74%, p30 - 46%, p39 - 44%, p83 - 38%, p19 - 31%, OspC/p25- 28%, p31 - 23%, p21 - 8%. Conclusions: laboratory diagnostic tests for Lyme disease must be performed in accordance with the current standards, positive and uncertain results must be confirmed by Westernblot test. Results of lab tests must correlate with patient’s symptoms.
PL
Wprowadzenie: Borelioza z L yme jest wielonarządową chorobą wywoływaną przez krętki Borrelia burgdorferi sensu lato, przenoszone przez kleszcze Ixodes, której obraz kliniczny wiąże się z zajęciem skóry, stawów, układu nerwowego i serca. Diagnostyka laboratoryjna boreliozy z L yme opiera się głównie na wykrywaniu przeciwciał anty-Borrelia burgdorferi metodami serologicznymi. Cel pracy: ocena poziomu przeciwciał dla specyficznych antygenów B. burgdorferi s.l. u osób z podejrzeniem boreliozy z L yme. Materiały i metody: grupę badaną stanowiło 98 pacjentów z podejrzeniem boreliozy z L yme. W pierwszym etapie wykonano oznaczenie przeciwciał IgM/IgG anty-Borrelia burgdorferi metodą ELISA, a wyniki pozytywne i graniczne potwierdzono testem Western blot (Wb). Wyniki: obecność przeciwciał IgM/IgG anty-B. burgdorferi wykazano u 60 pacjentów (61,2%). Przeciwciała tylko w klasie IgM oraz tylko IgG na poziomie dodatnim stwierdzono odpowiednio u 8 (8,1%) oraz 35 (35,7%) pacjentów. Współistnienie IgM i IgG stwierdzono u 6 osób (6,1%), w tym u 2 (2%) na poziomie dodatnim w obu klasach. U wszystkich pacjentów z pozytywnym wynikiem w klasie IgM (12 osób) obecne były przeciwciała anty-OspC, u 2 pacjentów dodatkowo obecne były przeciwciała anty-p31. U pacjentów z pozytywnym wynikiem w klasie IgG uzyskano następujące wyniki: przeciwciała przeciwko antygenowi p17 - 77% przypadków, VlsE - 74%, p30 - 46%, p39 - 44%, p83 - 38%, p19 - 31%, OspC/p25- 28%, p31 - 23%, p21 - 8%. Wnioski: prowadząc diagnostykę laboratoryjną boreliozy z L yme należy postępować zgodnie z obowiązującymi standardami, wyniki dodatnie i graniczne uzyskane metodą ELISA, należy potwierdzić testem Western blot. Wyniki badań laboratoryjnych muszą korelować z objawami występującymi u pacjenta.
first rewind previous Strona / 20 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.