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J Majewski

Publications and source records attributed to J Majewski.

52 records · Page 3Linked to original sources
PubMed1977

The activation of the C3b feedback cycle with human complement components. I. Through the classical pathway.

Reaction between the fourth, the oxidized second and the activated first components of human complement generated the stable enzyme C4oxy2 capable of cleaving the third component and depleting total complement in human serum. This enzyme was shown further to activate the C3b feedback cycle as shown by its ability to consume factor B in serum and the reduction in the extent of complement consumption in the presence of EDTA. OxyC2 on its own gave rise to C3 cleavage in normal human serum by a pathway needing classical pathway components. This unexpected finding suggests that there may be a 'C-1 tickover' in serum analogous to the 'C3b tickover'; the presence of oxyC2 allowing the 'capture' of the trivial amounts of C42 normally formed. In preliminary experiments in the rat, C4oxy2 was successfully formed in vivo, where it gave rise to cleavage of C3, consumption of C5, depletion of cobra venom factor cofactors and a biphasic change in the neutrophil count.

Animals↗
PubMed1977

The activation of the C3b feedback cycle with human complement components. II. Using components of the alternative pathway.

The C3 convertase of the C3b feedback cycle was generated in the fluid phase from C3b and factors B and D. It was shown to be an effective decomplementing agent when reacted with human serum. Many of the effects observed were dependent on the operation of the feedback during the ongoing reaction. Oxidization of factor B with iodine did not significantly increase the potency or the stability of the enzyme. Treatment of C3b with antrypol inhibited the formation of the enzyme. In preliminary experiments in the rat, the convertase was successfully formed in vivo, accompanied by cleavage of C3, consumption of C5, C6 and C7, and a biphasic change in the circulating neutrophils.

Animals↗
PubMedDate not supplied

[Spinal reflexes in the determination of brain death].

The authors present the results of spinal cord function evaluation in organ donors by examination of reflexes. The knee reflex and ankle jerk, as well as abdominal reflex and foot withdrawal reaction were tested in 31 donors. At least one of the above was seen in 25 individuals. It is suggested on the basis of data obtained not to hamper the transplant procedure in cases of tested reflex persistency when brain death is revealed on relevant examination.

Adolescent↗