Fenestration Operation for Otosclerosis

it will be unaffected by any kind of anti-Rh or other irregular agglutinin which the mother may have produced; The mother's whole blood should not, of course, be used, as its content of antibodies would aggravate the haemolytic disease. It is rational, however, to use the mother's red cells after centrifuging and thorough washing with saline to remove all traces of plasma. In most cases it is simpler to submit a sample of the mother's serum to the Blood Bank or Regional Transfusion Officer and receive a supply of carefully matched blood; but occasionally, when the nature of the iso-immunization is obscure, the use of the mother's washed red cells may be necessary to save the child. In such cases it is unimportant that the mother's cells may be of Group A or B and the child's cells of Group 0; owing to the absence of the natural iso-agglutinins in the newborn child, other than small amounts derived from the mother, the maternal red cells, whatever their group, are always compatible with the serum of the child. It is very much more important to examine the mother's blood for its Rh type than the child's, for in all cases due to Rh incompatibility the infant if affected is Rh-positive. When a suspected case is sent into hospital a sample of the mother's blood must always go along with the affected infant, for if she is Rhpositive it depends upon her genotype what kind of anti-Rh she is likely to have made. Anti-d and anti-e have not yet been detected in association with pregnancy, but Rh-positive mothers have been foudd to make either anti-c or anti-E. Accordingly the routine transfusion of infants suffering from haemolytic disease with Rh-negative blood will occasionally fail to give the best result, for in those with anti-c such blood would be susceptible to the irregular antibody and would be less effective. It is for this reason that a sample of the mother's blood should always be sent to hospital along with the infant. The mother's serum is used to perform a careful cross-matching test with the blood to be administered to the child, both at room temperature and at 370 C., and with further experience of Diamond's open slide test this method may be helpful in detecting incompatibilities not readily demonstrated by other methods. Summary An account is given of the development of knowledge about the Rh blood group. The different types of human iso-antisera have been described and the consequent deductions as to the antigenic structure of the Rh factor have been pointed out. The nomenclatures appiied by different workers in this field have been correlated and the need for clearer definition of " Rh-positive " and " Rhnegative " has been emphasized. While in the present state of knowledge Fisher's synthesis affords the most satisfactory explanation of the antigenic structure and mode of inheritanch of the Rh group, it is suggested that Fisher's Greek letter terminology for the antibodies might advantageously be replaced by one based more directly on the hypothetical elementary antigens of the Rh complex-e.g., anti-C instead of r, anti-D for A, etc. The types of clinical disorder resulting from iso-immunization by transfusion and in pregnancy have been presented and the pathogenesis of haemolytic disease of the newborn is discussed. Attention is drawn to the relative infrequency of haemolytic disease in heterospecific pregnancy. An outline is given of the management of a case of haemolytic disease, and the principles of treatment for the affected infant, both of Rh-positive and of Rh-negative mothers, are described.