[Cataract surgery at the Berlin Virchow clinic. Overview of the last 16 years]. / Kataraktchirurgie am Virchow-Klinikum-Berlin. Uberblick über die letzten 16 Jahre.

PURPOSE: The aim was to compare the different techniques of cataract surgery regarding early postoperative astigmatism and visual acuity. PATIENTS AND METHODS: The data of three groups of patients (100 eyes) were analyzed retrospectively (1980-1982; 1987-1990; 1991-1993). Three different techniques of cataract surgery were used. Included in the prospective study were the data for 285 eyes, which underwent phacoemulsification, self-sealing incision and controlled induction of astigmatism. RESULTS: In the time period retrospectively investigated, we found that because of the advancements in operation methods, there was a reduction in the amount of surgically induced astigmatism. From 1980 to 1995 there was a clear increase in the number of patients with early low-grade postoperative astigmatism < 1 D (1980-1982: 6%, 1987-1990: 19%, 1991-1993: 64%, 1994-1995: 84%). There was an improvement in postoperative vision (with correction > 0.5) of 16% in 1980-1982 to 45% from 1987 to 1990, 58% from 1991 to 1993, and to 76% in 1994-1995. CONCLUSIONS: Surgical induced a stigmatism, which was considered to be a sign of unwanted increased postoperative astigmatism, was reduced from 1980 to 1993. Through controlled induction of astigmatism it was possible to compensate for preoperative astigmatism in the prospective group. Improved surgical techniques led to improvements in early postoperative visual acuity.

Separation of two hepatitis B human antibody fractions by cold-ethanol precipitation.

Antibodies to three different samples of hepatitis B antigen-positive serum were found to be absent from a Cohn fraction II hepatitis B immune globulin preparation, but present in the whole plasma from which the immune globulin was made. Fractions containing the antibodies specific for the three antigen samples were isolated from the plasma by euglobulin precipitation, and the antibodies were characterized as to immunoglobulin class and precipitability in the Cohn fractionation procedure. They appear to be IgG antibodies which, however, were detectable only in Cohn fraction I, while the remainder of the HB specificity present in the original plasma was found, as expected, in fraction II.

The Duffy blood group system: a review of recent developments.

Five antigenic specificities are associated with the Duffy blood group system. Fya, Fyb, By3 and Fy4 are under the genetic control of a locus near the centromere of chromosome 1. Fy5 is absent from Fy (a-b-) red cells and also from cells that have the Rhnull phenotype. It appears that interaction between Duffy and Rh gene products may be necessary for synthesis of Fy5 antigen. Most Caucasians have a Fya or Fyb gene (or both), inherited by strict Mendelian principles. No evidence has been found to suggest that independently segregating Duffy modifying genes exist. The frequency of Duffy genes varies greatly in different sections of the world population. Aboriginal populations have a high frequency of Fya, Fyb is the most common gene in European Caucasians, and Negroes have a high frequency of an allele named Fy. Anti-Fya is the most common Duffy antibody and is found most frequently in the serum of Caucasians immunized by blood transfusion. The Fya antigen is about 40 times less immunogenic than K antigen of the Kell system. Only about one anti-Fyb serum is found foe every 20 that are anti-Fya. The Fya and Fyb red cell antigen receptors are inactivated by proteolytic enzymes but not by neuraminidase. Sialic acid does not appear to be an essential component of the antigen structure. Duffy antigens appear to be thermolabile membrane proteins and they are not present in a soluble form in plasma or in body secretions.