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Biomedical subjects

R Arnon

Publications and source records attributed to R Arnon.

303 records · Page 17Linked to original sources
PubMed1967

Biological activity of the cleavage product of human immunoglobulin G with cyanogen bromide.

Treatment of human IgG with cyanogen bromide in 0.05 M HCl under specified conditions resulted in the cleavage of about half of its methionyl peptide bonds. A major fragment of about 5S was isolated from the reaction mixture by gel filtration in quantitative yield. The CNBr fragment reacted fully with goat antiserum against human light chain, but its reaction with anti-heavy chain was markedly decreased. The treatment with CNBr caused a drastic decrease in the following biological activities of IgG: complement fixing, skin binding, reaction with antiglobulin factors, and reaction with specific anti-Gm(12) serum. On the other hand, the reaction with serum of anti-Gm(1) or anti-Gm(4) specificity was not impaired and antibody activity, namely antistreptolysin and isohemagglutinin, was retained after the treatment with CNBr. It is concluded that the CNBr cleaves preferentially the methionyl bonds in the Fc portion of IgG, and that the major fragment obtained, denoted F(ab'')(2), has still the combining properties of a divalent antibody. The possible therapeutic uses of F(ab'')(2) are discussed.

Antibody Formation↗
PubMedDate not supplied

Peptide-based synthetic recombinant vaccines with anti-viral efficacy.

Synthetic recombinant vaccines are constructs in which a synthetic oligonucleotide coding for a protective epitope is inserted into an adequate gene for expression of the epitope. We report the results obtained using recombinant flagella of Salmonella vaccine strain expressing epitopes of influenza virus or of the parasite Schistosoma mansoni. In the case of influenza virus, three conserved epitopes of the haemagglutinin and the nucleoprotein of the virus inducing B- and T-cell immune response, were expressed and the flagella were used for intranasal immunization without any adjuvant. Both humoral and cellular immune responses specific to the virus induced in mice cross-strain long-term protection against challenge infection. Aged mice were also able to resist infection. For the design of a human influenza vaccine, epitopes recognized by the HLAs prevalent in Caucasian populations were used, and the resulting vaccine was evaluated in human/mouse radiation chimaera in which human PBMC are functionally engrafted. The vaccinated mice demonstrated efficient clearance of the virus after challenge and resistance to lethal infection. In the case of the parasitic disease schistosomiasis, a 14-residue peptide denoted 9B peptide 1 was expressed in the flagella. Intranasal vaccination of mice with this construct, without the use of adjuvant, resulted in 40% protection against challenge infection.

Animals↗
PubMedDate not supplied

Transesophageal echocardiographic guidance of balloon atrial septostomy.

Two newborn infants with transposition of the great vessels and an intact ventricular septum were cyanotic when they underwent bedside balloon atrial septostomy in the neonatal intensive care unit. The procedure was conducted under direct transesophageal two-dimensional echocardiographic guidance. Success of the procedure was evaluated with color flow Doppler and the two-dimensional assessment of the septostomy. This procedure has advantages over catheterization and its attendant fluoroscopy, which usually are performed in the catheterization laboratory, expose the patient to radiation, and necessitate transportation of a patient who is hemodynamically unstable to an often distant catheterization laboratory. Transesophageal echocardiography has several advantages over transthoracic echocardiography in aiding this procedure. It provides an optimal view of the atrial septum, while keeping the chest exposed for observation of respiratory effort and for improved thermoregulation.

Catheterization↗