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Biomedical subjects

N Page

Publications and source records attributed to N Page.

31 records · Page 2Linked to original sources

A monoclonal anti-idiotypic antibody against a human monoclonal IgM with specificity for myelin-associated glycoprotein.

A human monoclonal IgM lambda antibody, directed against MAG, obtained from a patient with polyneuropathy associated with a gammopathy, was used as an immunogen to generate mouse monoclonal anti-idiotype antibodies. One hybridoma antibody, designated A8F2, reacts uniquely with the M-IgM of the patient, shows high affinity binding to the patient's M-IgM, and dose-dependently inhibits binding of the patient's M-IgM to its specific antigen MAG. Thus, A8F2 is a monoclonal anti-idiotype antibody that recognizes a region of the MAG binding site of the patient's IgM. Use of this anti-idiotype antibody in a competition RIA revealed the presence of naturally occurring anti-idiotype in the patient's serum. Because anti-idiotype antibodies may be part of a mechanism for down-regulation of antibody production, the use of A8F2 to induce a specific immunosuppression should be considered.

Animals↗

Human monoclonal antibodies to myelin-associated glycoprotein are directed against the polypeptide and not the carbohydrate moiety.

We have used an approach which combines the technique of electrophoretic blotting of polyacrylamide gels with methods for the degradation of carbohydrates, to study the myelin-associated glycoprotein (MAG)-specific antibodies found in 5 patients with demyelinating neuropathy. Our results show that it is possible to deglycosylate proteins on nitrocellulose blots and then to examine their antigenicity and lectin-binding properties. With MAG, our findings suggest that the monoclonal IgM antibodies from all the patients studied have specificity for the polypeptide and not the carbohydrate moiety.

Antibodies, Anti-Idiotypic↗

The differential diagnosis of congenital nystagmus.

The decision whether a nystagmus is congenital or acquired may be difficult and is of importance in patients presenting with neurological complaints. In this article, established diagnostic criteria are critically reviewed with particular emphasis on types of nystagmus waveform and their relationship to pursuit and optokinetic responses. Attention is drawn to certain acquired nystagmus which may have similar features which have hitherto been accepted as pathognomonic of congenital nystagmus. Symptoms due to congenital nystagmus are discussed and related to the oculomotor abnormalities. The importance of the characteristics of congenital nystagmus are evaluated for use in differential diagnosis.

Diagnosis, Differential↗

Binding properties of cerebrospinal fluid IgG in multiple sclerosis and other neurological diseases.

A solid phase radioimmunoassay (RIA) was used to detect antibodies to myelin or myelin basic protein (MBP) in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) or other neurological diseases (OND). When measured at the same IgG concentration, MS samples had higher binding values than OND against myelin, but not against MBP. Using F(ab')2 fragments purified from pools of MS and OND CSF there was no difference in binding to myelin between MS and OND samples. These results indicate that anti-MBP antibodies are nt a feature of MS and binding of CSF IgG to myelin is not due to specific antibody, but is probably the result of non-specific binding to Fc receptors.

Humans↗

Demyelinating neuropathy and monoclonal IgM antibody to myelin-associated glycoprotein.

We studied a patient with demyelinating neuropathy and monoclonal IgM kappa antibody to the major myelin-associated glycoprotein (MAG). Binding of this monoclonal antibody to the myelin antigen was demonstrated by immunoelectroblot. Binding to MAG seemed to be specific, because it was completely inhibited by MAG isolated from human myelin. Immunostaining was observed with MAG from CNS and peripheral nervous system myelin.

Antibodies, Monoclonal↗

The effect of specific antibody on antibody-independent interactions between E. coli J5 and human complement.

We previously reported that Escherichia coli J5, the galactose epimerase-deficient mutant of E. coli O111:B4, can bind and activate purified human C1. The effects of hyperimmune rabbit anti-J5 IgG or IgM on E. coli J5 interactions with human C have been examined. Specific IgG or IgM increased the binding of 125I-C1 by J5. However, the rate of C1 activation, as determined by SDS-PAGE of eluted 125I-C1s, was decreased if bacteria were preincubated with immune IgG. Complexes formed between J5 preincubated with immune Ig and C1, under conditions in which all of the C1 was allowed to activate, consumed more C4 than J5 alone plus C1. However, the amount of C4 consumed per C1 molecule was identical for all bacteria preparations. Concentrations of specific IgG or IgM that significantly increased C1 binding did not appear to enhance C3b deposition upon incubation of E. coli J5 in NHS. Thus, although specific antibody may enhance C1 binding by E. coli J5, the ability of these additional C1 molecules to alter later events in the C cascade may depend on the control of C1 activation and its subsequent activity when bound to different membrane components.

Animals↗

Synergism between iron chelators and complement for bactericidal activity.

Iron-binding agents such as the plasma protein transferrin or the siderophore desferal from Streptomyces pilosus inhibit the growth of pathogenic bacteria, supposedly by interfering with iron uptake by those bacteria. This study shows that anti-Escherichia coli activity exerted by desferal and transferrin can be increased in a synergistic way by complement and anti-E. coli antibodies of normal serum.

Complement System Proteins↗

The development of a genetic profile of placental gene expression during the first trimester of pregnancy: a potential tool for identifying novel secreted markers.

OBJECTIVES: Many of the maternal serum markers used in prenatal screening have been developed or evolved based on serendipity. This study determines the feasibility of developing a genetic profile of placental gene expression during early pregnancy; such a gene repertoire may serve as a tool for identifying novel secreted markers. METHODS: RNA fingerprinting was used to produce a differential expression map in normal aborted placentae of weeks 9 and 13. RESULTS: Out of 212 gene expression differences, 115 were up-regulated at week 9 and the remaining 97 up-regulated at week 13. Ninety-four were found to be previously characterised genes and 118 were expressed sequence tags or novel genes. Seven of the known genes were found to be secreted proteins and included well-characterised pregnancy markers. mRNA levels of these secreted proteins were found to correlate with levels found in maternal serum. CONCLUSION: This approach enabled the identification of known secreted markers leaving open the possibility of finding new markers. With the human genome project nearing completion, it will be vital to use a systematic approach to understand the actual pattern of gene expression during pregnancy. This will also allow a more ordered and precise identification of novel prenatal diagnostic markers.

Amino Acid Sequence↗