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Biomedical subjects

R Burger

Publications and source records attributed to R Burger.

At least 181 records · Page 10Linked to original sources
PubMed1977

Technique of general anesthesia for tonsillectomy and adenoidectomy.

This article reports a technique of general anesthesia for tonsillectomy, according to the method of Sluder-Ballanger. For induction of the anesthesia the children receive: ketamine (1 to 1.5 mg/kg), succinylcholine (1 mg/kg). They are intubated through the nose and then ventilated by a mixture of N2O and O2 (50% - 50%). For the intervention they are brought in sitting position. The authors discuss the advantages of this technique as much from the anesthetic as from the surgical point of view.

Adenoidectomy↗
PubMed1976

Mouse factor B of the alternative pathway of complement activation. I. Purification, characterization, and functional behavior.

Mouse factor B was purified and a monospecific antiserum was raised. The physicochemical data of this protein (108,000 m.w., 5.9 S, 5.9 to 6.05 isoelectric point) were determined. The functional behavior resembles that of human and guinea pig factor B and it operates efficiently in the C3 feedback cycle of the alternative pathway of complement activation. A provisional scheme is given for the operation of the C3bB enzyme on the cellular (macrophage) level.

Animals↗
PubMed1975

D-alanyl-D-alanine carboxypeptidase in the bacterial form and L-form of Proteus mirabilis.

Membranes of the bacterial form and the stable and unstable L-forms of Proteus mirabilis contain LD and DD-carboxypeptidase. The DD-carboxypeptidase is inhibited non-competitively by penicillin G. The enzyme of the bacterial form is highly penicillin-sensitive (Ki - 4 X 10(-9) M penicillin G). Inhibition is only partly reversible by treatment with penicillinase or by dialysis against buffer. In contrast, the DD-carboxypeptidase of the unstable L-form, grown in the presence of penicillin, is 175-fold less penicillin-sensitive (Ki = 7 X 10(7) M penicillin G). Inhibition is completely reversed by penicillinase or dialysis. After inhibition by penicillin and subsequent reactivation the penicillin sensitivity of the bacterial DD-carboxtpeptidase is similar to the sensitivity of the enzyme of the unstable L-form. The hypothesis is proposed that P. mirabilis contains two DD-carboxypeptidases of different penicillin sensitivity and with different mechanisms of penicillin binding. Peptidoglycan synthesis in the cell walls of the unstable L-form is probably carried out with the help of only one DD-carboxypeptidase, viz. the completely reactivatable enzyme with the lower penicillin sensitivity.

Alanine↗
PubMed1975

Dextran sulphate: a synthetic activator of C3 via the alternative pathway. I. Influence of molecular size and degree of sulphation on the activation potency.

The polyanion dextran sulphate (DS) triggers the alternative pathway of complement. The influence of the molecular weight and degree of sulphation on this potency was studied. The degree of substitution turned out to be the critical parameter for optimal C3 turnover: 60 SO4/100 glucose units (Glc) showed optimal activity; an increase up to 190 SO4/100 Glc did not increase the activation potency, while lowering the degree of sulphation diminished this activity. DS preparations (120 SO4/100 Glc) of molecular weight: 1 x 10(4); 8 x 10(4); 2-5 x 10(5); 2 x 10(6) were equally active; a DS of molecular weight 5 x 10(3) was inactive. These results indicate that above a critical molecular size (greater than 5 x 10(3)) only the degree of substitution is responsible for the C3 activating capacity. Clusters of several glucose residues each carrying one or two sulphate groups are thought to be the essential structure in DS for the activation of the alternative pathway.

Animals↗
PubMed1975

Interaction of C3b, B, and D in the alternative pathway of complement activation.

The interaction of ZXd2, an insoluble intermediate of the alternative pathway on zymosan (Z5), with factor B and the enzyme D proceeds in a two-step reaction: 1) B binds in the presence of Mg++ to ZXd2 to form the intermediate ZXd2B, 2) B bound to ZXd2 is subsequently activated enzymatically by D to yield the complex ZXd2B which cleaves C3. Evidence was obtained that C3b, which is present on ZXd2, is required for ZXd2B formation. Studies of the functional role of C3b for ZXd2B formation revealed that C3b is involved in the first reaction step i.e., binding of B to ZXd2 to yield ZXd2B. Formation of ZXd2B is inhibited by pretreatment of ZXd2 with either anti-C3 Fab or with C3b-INA. Low ionic strength of about 2 mS was found to favor the interaction of the C3b with B. Mg++ concentrations from 1 to 31 mM as well as variation of pH in the range from 6.2 to 8.5 did not greatly influence the reaction of B with ZXd2. For the enzymatic activation of B only C3b on ZXd2 and factor D are required. This is concluded from the finding that fluid phase C3b is sufficient for the activation of B in the presence of D. This does not exclude the fact that other proteins present on ZXd2 may help to stabilize the intermediate ZXd2B or the enzymatically active complex AXd2B, or both of them.

Animals↗