scholarly journals IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS

1971 ◽  
Vol 134 (2) ◽  
pp. 439-457 ◽  
Author(s):  
Carlos Moreno ◽  
Arne Lundblad ◽  
Elvin A. Kabat
Keyword(s):  
Complement Fixation ◽  
Blood Groups ◽  
Structural Basis ◽  
Antigenic Determinants ◽  
Absorption Studies ◽  
Inhibition Studies

The immunochemical properties of purified A1 and A2 glycoproteins have been compared to ascertain whether their antigenic determinants differ. Quantitative precipitin and complement-fixation studies using several anti-A sera as well as purified γG anti-A antibodies clearly showed a specificity difference. This was also supported by absorption studies: A2 substance specifically removed antibodies reacting with A2 substance leaving anti-A1 activity. A1 substance was more effective than A2 substance in dissolving an A1 anti-A1-specific precipitate. Purified γM anti-A hemolyzed A1 cells more readily than A2 cells. Inhibition studies using mono- and difucosyl type 2 A-active oligosaccharides showed that type 2 difucosyl receptors are present in A2 substance. The structural basis for the specificity difference between A1 and A2 would appear to be that A2 substances lack type 1 A determinants; this would account for the observed higher H and Leb activity in A2 substances.

Discovery of natural product ovalicin sensitive type 1 methionine aminopeptidases: molecular and structural basis

2019 ◽  
Vol 476 (6) ◽  
pp. 991-1003 ◽  
Author(s):  
Vijaykumar Pillalamarri ◽  
Tarun Arya ◽  
Neshatul Haque ◽  
Sandeep Chowdary Bala ◽  
Anil Kumar Marapaka ◽  
...  
Keyword(s):  
Natural Product ◽  
Active Site ◽  
Covalent Modification ◽  
Structural Basis ◽  
Wild Type ◽  
Methionine Aminopeptidases ◽  
Synthetic Derivative ◽  
Dynamics Simulations

Abstract Natural product ovalicin and its synthetic derivative TNP-470 have been extensively studied for their antiangiogenic property, and the later reached phase 3 clinical trials. They covalently modify the conserved histidine in Type 2 methionine aminopeptidases (MetAPs) at nanomolar concentrations. Even though a similar mechanism is possible in Type 1 human MetAP, it is inhibited only at millimolar concentration. In this study, we have discovered two Type 1 wild-type MetAPs (Streptococcus pneumoniae and Enterococcus faecalis) that are inhibited at low micromolar to nanomolar concentrations and established the molecular mechanism. F309 in the active site of Type 1 human MetAP (HsMetAP1b) seems to be the key to the resistance, while newly identified ovalicin sensitive Type 1 MetAPs have a methionine or isoleucine at this position. Type 2 human MetAP (HsMetAP2) also has isoleucine (I338) in the analogous position. Ovalicin inhibited F309M and F309I mutants of human MetAP1b at low micromolar concentration. Molecular dynamics simulations suggest that ovalicin is not stably placed in the active site of wild-type MetAP1b before the covalent modification. In the case of F309M mutant and human Type 2 MetAP, molecule spends more time in the active site providing time for covalent modification.

scholarly journals IMMUNOLOGIC STUDIES OF WATER-SOLUBLE HUMAN AMYLOID FIBRILS

1969 ◽  
Vol 130 (4) ◽  
pp. 797-808 ◽  
Author(s):  
Edward C. Franklin ◽  
Mordechai Pras
Keyword(s):  
Human Serum ◽  
Comparative Studies ◽  
Amyloid Fibrils ◽  
Complement Fixation ◽  
Cross Reactivity ◽  
Water Soluble ◽  
Antigenic Determinants ◽  
Normal Tissues ◽  
Absorption Studies ◽  
Normal Human

Eight preparations of soluble amyloid and degraded amyloid (DAM) were compared immunologically. Unlike amyloid fibrils, six of eight preparations of DAM proved to be relatively strong immunogens. Antisera to DAM reacted weakly or not at all with normal human serum or extracts of normal tissues, but were specifically reactive with amyloid fibrils or DAM. Comparative studies of DAM'S from eight different subjects showed some degree of cross-reactivity among them, yet demonstrated that they were not identical. Similar conclusions were obtained by quantitative precipitin and complement fixation analyses. Comparison of the amyloid fibrils with the homologous DAM by complement fixation and absorption studies demonstrated the existence in DAM of antigenic determinants that were lacking or inaccessible in the native fibrils. A search for amyloid precursors and antibodies to amyloid in the sera of 12 patients proved unsuccessful.

scholarly journals The use of new antigens in the complement-fixation test for acute poliomyelitis

1960 ◽  
Vol 58 (3) ◽  
pp. 321-330 ◽  
Author(s):  
Golda Selzer
Keyword(s):  
Antibody Response ◽  
Technical Assistance ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Fixation Test ◽  
City Hospital ◽  
Poliovirus Type ◽  
Acute Poliomyelitis

A complement-fixation test for acute poliomyelitis using unheated antigens derived from suckling mouse brain infected with poliovirus Type 1 or Type 2 is described.The results of tests in 62 patients clinically diagnosed as cases of acute poliomyelitis in a recent epidemic and in 26 controls are recorded.The CF tests were positive in 100% of 53 cases with poliovirus Type 1 and/or Type 2 in stool. A positive result was obtained in 23 (76%) of 30 cases whose sera were examined in the first 7 days of illness.Negative tests of the initial serum samples were found in 15 (28·5%) of 53 cases, but all these became positive in titres of 40 or 80 on testing of convalescent serum.In 31 (69%) of 45 cases whose sera were re-tested between the 3rd and 4th weeks of illness the CF antibody levels rose, reaching titres of 80 or 160 in most instances. Of the remaining 14 cases only one dropped in insignificant degree (from titre 320 to 160) and the 13 stationary results had been positive in titres of 40–160 on initial tests most of which were performed in the 2nd week of illness.Homotypic CF antibody response without crossing was found in 37 (71%) of 52 cases with Type 1 or Type 2 virus in stool. In the cases of crossing the heterotypic antibody response was either transient, diminishing or stationary in all and in only low titre in most instances.In 26 control cases there were seven positive CF tests, but one of these was nonspecific, five were in lowest titres, and one case appeared to have had recent poliomyelitis infection.Heating the antigens did not broaden the reaction. It caused only slight loss of potency except in two cases in which the CF titre increased substantially.The antigenic preparation described appears to be superior to antigens of other origin in the diagnosis of acute poliomyelitis by complement-fixation tests, as positive tests are recognized earlier in the illness and the titres are higher. Homotypic results were obtained in all cases and no instance of false negative occurred in this series.I would like to thank the medical staff of the Cape Town City Hospital for Infectious Diseases for the trouble taken in collecting stools and paired sera, and Prof. Kipps for his interest in this work. I am indebted to Miss Karin Larssen for valuable technical assistance.

scholarly journals ANTIGENIC RELATEDNESS OF SELECTED FLAVIVIRUSES: STUDY WITH HOMOLOGOUS AND HETEROLOGOUS IMMUNE MOUSE ASCITIC FLUIDS

1998 ◽  
Vol 40 (6) ◽  
pp. 343-349 ◽  
Author(s):  
S.S. BABA ◽  
A.H. FAGBAMI ◽  
O.D. OLALEYE
Keyword(s):  
Antigenic Variation ◽  
Complement Fixation ◽  
Haemagglutination Inhibition ◽  
Antigenic Relationship ◽  
Serological Relationship ◽  
Immune Mouse ◽  
Antigenic Relatedness ◽  
Relationship Of

The antigenic relationship of 9 flaviviruses, Yellow fever (YF) , Wesselsbron (WSL) , Uganda S (UGS) , Potiskum (POT), West Nile (WN) , Banzi (BAN) , Zika (ZK) , Dengue type 1 (DEN-1) and Dengue type 2 (DEN-2), was assessed by cross-haemagglutination-inhibition (Cross-HI) and cross-complement fixation (Cross-CF) reactions between each of the viruses and their homologous immune mouse ascitic fluids. Titre ratios were calculated using the heterologous and homologous titres. Cross-CF reactions revealed wider antigenic variations among viruses than Cross-HI reactions. There was no significant antigenic variation between WSL, POT and YF viruses using either of those methods. However, definite differences in antigenicity were observed between them and UGS, BAN and ZK viruses. There were no significant differences between UGS, BAN and ZK or between DEN-1 and DEN-2. The serological relationship among flaviviruses is important in establishing diagnosis and epidemiology of these infections in Africa.

scholarly journals Long-Term Circulation of Vaccine-Derived Poliovirus That Causes Paralytic Disease

2002 ◽  
Vol 76 (13) ◽  
pp. 6791-6799 ◽  
Author(s):  
Elena A. Cherkasova ◽  
Ekaterina A. Korotkova ◽  
Maria L. Yakovenko ◽  
Olga E. Ivanova ◽  
Tatyana P. Eremeeva ◽  
...  
Keyword(s):  
Vaccine Strain ◽  
Natural Circulation ◽  
Population Analysis ◽  
Paralytic Poliomyelitis ◽  
Antigenic Determinants ◽  
Successful Implementation ◽  
Amino Acid Mutations

ABSTRACT Successful implementation of the global poliomyelitis eradication program raises the problem of vaccination against poliomyelitis in the posteradication era. One of the options under consideration envisions completely stopping worldwide the use of the Sabin vaccine. This strategy is based on the assumption that the natural circulation of attenuated strains and their derivatives is strictly limited. Here, we report the characterization of a highly evolved derivative of the Sabin vaccine strain isolated in a case of paralytic poliomyelitis from a 7-month-old immunocompetent baby in an apparently adequately immunized population. Analysis of the genome of this isolate showed that it is a double (type 1-type 2-type 1) vaccine-derived recombinant. The number of mutations accumulated in both the type 1-derived and type 2-derived portions of the recombinant genome suggests that both had diverged from their vaccine predecessors ∼2 years before the onset of the illness. This fact, along with other recent observations, points to the possibility of long-term circulation of Sabin vaccine strain derivatives associated with an increase in their neurovirulence. Comparison of genomic sequences of this and other evolved vaccine-derived isolates reveals some general features of natural poliovirus evolution. They include a very high preponderance and nonrandom distribution of synonymous substitutions, conservation of secondary structures of important cis-acting elements of the genome, and an apparently adaptive character of most of the amino acid mutations, with only a few of them occurring in the antigenic determinants. Another interesting feature is a frequent occurrence of tripartite intertypic recombinants with either type 1 or type 3 homotypic genomic ends.

scholarly journals THE ESSAY IN RUSSIAN 18th-CENTURY SATIRICAL MAGAZINES

2020 ◽  
Vol 12 (3) ◽  
pp. 124-131
Author(s):  
Lev A. Trakhtenberg ◽  
Keyword(s):  
18Th Century ◽  
Structural Basis ◽  
Focus Attention ◽  
Class Iii ◽  
Form Type ◽  
Literary Unity ◽  
Description Form

18th-century satirical magazines laid the foundations of the essay as a genre in the modern sense of the word. They formed a paradigm of essay in its various forms. The paper presents a typology of essays in satirical magazines. There are considered such magazines as Vsyakaya vsyachina (All Sorts of Things) edited by Catherine II, I to i se (This and That) and Parnasskiy shchepetil’nik (The Parnassian Vendor) by Mikhail Chulkov, Truten’ (The Drone), Pustomelya (The Tattler), Zhivopisets (The Painter) and Koshelek (The Purse) by Nikolai Novikov, Rasskazchik zabavnykh basen (The Teller of Amusing Stories) by Aleksandr Ablesimov etc. Essays are divided into three classes: in the first one, reflection and description form the structural basis of the text; the second is organized by narration; the third one combines the features of the first two. The classes are further subdivided into types according to the role of the editor as a fictitious persona being the primary subject of speech in the magazine. The first type of all classes is formed by essays that focus attention on the editor; articles where the editor plays a secondary role fall within the second type. In class I, type 1 is formed by essays characterizing the editor, while those in which other topics prevail fall under type 2. In class II, essays in which the editor takes part in the plot form type 1, while those where they do not fall into type 2. In class III, type 1 is characterized by the editor’s hegemony throughout the whole text, while in type 2 the editor’s position may change from part to part of the essay. The classification also takes into account such devices as dialogue and frame. Essays involving fantasy elements are specially marked. The editor’s persona makes essays in satirical magazines unique among all versions of the genre. It unites all the articles in a single magazine. This gives the magazine integrity, making it a continuum. Thus, essays become part of a complex literary unity.

scholarly journals DEVELOPMENT, PERSISTENCE, AND SIGNIFICANCE OF TYPE 2, POLIOMYELITIS COMPLEMENT-FIXING ANTIBODY IN MAN

1952 ◽  
Vol 96 (1) ◽  
pp. 35-53 ◽  
Author(s):  
Jordi Casals ◽  
Peter K. Olitsky ◽  
Albert B. Sabin
Keyword(s):  
Complement Fixation ◽  
Age Groups ◽  
Neutralizing Antibody ◽  
Paralytic Poliomyelitis ◽  
Newborn Mice ◽  
History Of ◽  
Almost All ◽  
Type 3

Sera from 81 patients with a diagnosis of paralytic or non-paralytic poliomyelitis, and from 159 individuals of similar age groups giving no history of the disease, were tested with a high titered, complement-fixing poliomyelitis antigen of Type 2 (Lansing-like). The antigen consisted of brain tissue from newborn mice injected with the MEF1 strain of virus as previously adapted to these animals. The presence or absence of Type 2 neutralizing antibody in the sera under test was found not to affect the complement fixation. Positive reactions were obtained with 57 per cent of the sera deriving from non-paralytic patients and in 70 per cent from paralytics, when the specimens were tested at a dilution of 1:16. The complement-fixing antibody was often present in highest titer as early as 24 hours after the onset of poliomyelitis, and in almost all instances within 7 days. In about half of the patients a 4-fold or greater drop in titer occurred within 3 months, with little or no change in the others. The incidence of titers of 1:16 or higher with the control sera varied with the season of the year at which they were procured, 3 per cent of the winter samples proving positive and 13 per cent of the summer. The tests of sera from the group of patients from whom poliomyelitis virus was recovered, disclosed no significant differences between those having the paralytic and those having the non-paralytic disease. Type 1 (Brunhilde-like) strains of virus were recovered from many of the patients yielding positive tests, although they presented no evidence of previous or concurrent infection with Type 2 virus. This finding shows that Type 1 virus can give rise in patients to Type 2 complement-fixing antibody. The application of these data to the serologic diagnosis of poliomyelitis infection in man will of necessity be limited until information is obtained on the development, persistence, and significance of complement-fixation reactions with antigens deriving from Type 1 and Type 3 poliomyelitis strains.

The conformations of oligosaccharides related to the ABH and Lewis human blood group determinants

1980 ◽  
Vol 58 (6) ◽  
pp. 631-653 ◽  
Author(s):  
R. U. Lemieux ◽  
K. Bock ◽  
L. T. J. Delbaere ◽  
S. Koto ◽  
V. S. Rao
Keyword(s):  
Blood Group ◽  
Human Blood ◽  
Antigenic Determinants ◽  
Anomeric Effect ◽  
Human Blood Group ◽  
Good Accord ◽  
Resonance Properties ◽  
Synthetic Oligosaccharides

Nuclear magnetic resonance properties are shown to be in good accord with those that are expected for synthetic oligosaccharides in the conformations which are predicted by hard-sphere molecular modelling and taking into consideration the important contribution by the exo-anomeric effect. The studies involve first a comparison of the βDGal(1 → 3)βDGlcNAc (Type 1) and βDGal(1 → 4)βDGlcNAc (Type 2) disaccharide structures based mainly on 13Cmr and then an examination of the relationships between the calculated conformations and 1Hmr and 13Cmr parameters for human blood group determinants which are derived from the Type 1 core disaccharide. Among the structures examined are the di-, tri-, and tetrasaccharides for the ABH and Lewis antigenic determinants. Certain immunological–conformational relationships are noted.

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