Biomedical subjects
Publications and source records attributed to J Freedman.
With increasing demand for platelet transfusion the need to use platelets from Rh-positive persons for Rh-negative individuals often arises. The administration of Rho(D) immune globulin (human) in this situation has been recommended, but may cause serologic difficulties owing to the recipient's passive acquisition of antibodies other than anti-D.
Normal red blood cells (RBC) from fresh EDTA and CPD blood and from stored CPD blood were examined for the presence of bound subcomponents of C3 and C4. By serologic agglutination tests, only C3d was detectable on the cells. Incubation in compatible fresh normal serum (FNS) at 37 degrees C appeared to increase the amount of 3Cd on the RBC. C3b was serologically detectable only on stored CPD cells and only after incubation in compatible FNS. No. C4 components were detected on the cell surfaces in agglutination tests. Using an indirect labeling technique, small, but significant, amounts of C3d and C4d were found on all three types of untreated cells. C3b was present on stored CPD cells only. The indirect labeling technique showed a significant increase in C3d and C4d on all cells following incubation i- compatible FNS, whereas bound C3b was significantly increased only with stored CPD cells. There was no increase in bound C4b following serum incubation. The average number of C3d molecules per cell on normal EDTA cells was 557 and average Ko was 3.6 x 10(7) l/mol.
Four cases of conjunctival squamous carcinoma invading the cornea are presented. The surgical technique of excising the tumours from the cornea by lamellar keratectomy is described. Histology of the lesions showed well differentiated squamous carcinoma invading the superficial layers of the cornea only. Large invasive squamous cell carcinomas of the cornea result because of neglect of small paralimbal tumours and can be adequately removed by lamellar keratectomy, leaving the globe intact.
An antiglobulin reagent containing anti-IgG, -C4c, -C4d, -C3c, and -C3d was used to test red blood cells from healthy subjects and from patients in hospital. In tests read macroscopically on opal tiles, no positive reactions were found in the healthy subjects. Positive reactions were, however, observed in 7% of the hospital patients. Further tests with monospecific reagents showed the positive reactions to be due to the presence of C4d and C3d on the red cells. All patients with positive antiglobulin reactions had serious disease, in most cases associated with abnormal antibody production or abnormal immunoglobulin levels.
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Three cases of xeroderma pigmentosa in Bantu patients with corneal opacification are presented. The histologic appearances of the corneae following corneal transplantation is given.
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Two cases of late endophthalmitis after trabeculectomy surgery are described. Despite intensive antibiotic therapy, the visual end result in both cases was poor. The incidence of endophthalmitis after trabeculectomy, according to this report is similar to that after Scheie's procedure, but less than that after trephination. A possible cause of endophthalmitis is the anterior dissection of the superficial scleral flap into the cornea.
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The characteristics of an immunohematologic reaction to isoniazid are described with emphasis on the mechanism of development of the positive antiglobulin test. In contrast to previous findings, the antibody is a firmly bound IgG complement-binding antibody, reacting best at 37 degrees C by antiglobulin techniques and only with isoniazid presensitized cells. A method for preparing isoniazid-sensitized cells is described.
Peripheral iridectomy in trabeculectomy surgery should be larger than the scleral opening to prevent adherence of iris to the edges of the scleral opening. A method for the fashioning of such an iridectomy is described.
Two patients with autoimmune haemolytic anaemia of no obvious aetiology are presented. Both cases had IgM autoantibodies which were cold agglutinins with anti-I specificity and were complement binding. Both cases also had IgG autoantibodies which were incomplete, of wide thermal range and also had anti-I specificity, but were not complement binding. The red cells of both patients were coated with C4/C3d and IgG.
A patient with autoimmune haemolytic anaemia due to an autoagglutinin of anti-IT specificity is reported. The antibody was of the IgM class and bound complement; unexpectedly, it reacted optimally at 37 degrees C. A prozone was noted when testing serial dilutions of the patient's serum against appropriate red cells in saline, but was not found when testing an eluate prepared from the patient's red cells. Investigations suggested that the prozone was due to a blocking antibody of high molecular weight, which appeared to be specific for I and IT.
A simplified method was developed for preparing rabbit red cells coated only with human C3d by the alternative pathway; these cells were injected into the donor rabbit to prepare an anti-C3d serum. Monkey red cells were sucessfully coated with human C4d, using a low-ionic-strength method, and these cells were injected into the donor monkey to prepare anti-human C4d. The reactions of these reagents were compared with those of antisera raised to complement-coated red cells by previously described methods and with those of antisera obtained by immunizing rabbits with purified soluble human C3d.
Substitution of trypsin for Konglutinogen-activating factor (KAF) in the procedure for cleaving C3d from C3-C3b substrate produced a relatively heterogeneous low-molecular-weight fraction (C3d-Tryp) which differed in a number of ways from the KAF-mediated cleavage product (C3d-KAF). The differences were demonstrable by agar and polyacrylamide gel electrophoresis, 125I-labelling, content of immunoreactive 125I-labelled C3d, inhibition of anti-complement antiglobulin reagents and rabbit immunization. By comparison with C3d-KAF, the C3d in C3d-Tryp was more heterogeneous and exhibited a faster electrophoretic mobility in agar at pH 8.6. By contrast to C3d-KAF, C3d-Tryp contained protein carrying C3c antigenic determinants.
A comparative study of the effectiveness of Watson's and Cairns's trabeculectomy in a Black South African population with open-angle glaucoma is presented. The eventual success rate of 91-6% is comparable with that found in Whites, and the results were similar with both methods.
A case of xeroderma pigmentosum with associated band-shaped nodular dystrophy of the cornea is discussed. Band-shapped nodular dystrophy of the cornea usually occurs in elderly Bantu men. Band-shaped nodular dystrophy in a young Bantu man suffering from a genetically determined solar sensitive disease lends credence to the possibility that band-shaped nodular dystrophy is a solar sensitive disease, as has so often been postulated.
Purified soluble C3d has been employed to measure the concentration of anti-C3d antibodies in immune rabbit sera. Multiple batches of C3d, prepared from C3-C3b substrate by treatment with C3b-inactivator (KAF), after labelling with 125I, retained 80% immunoreactivity, and were stable on storage at -50 degrees and +4 degrees. Concentrations of anti-C3d were determined by Scatchard analysis of equilibrium concentrations of bound and free C3d in a mixture of 125I-labelled C3d and anti-C3d. Separation of bound from free C3d was by G-75 Sephadex filtration. Assuming a 1:1 molar ratio in the antibody-C3d complex, anti-C3d antibody concentrations for four rabbit whole antisera and four IgG preparations fell in the range 288-2433 microgram/ml, with Ko values of 6-2 X 10(8)-2-9 X 10(9) litres/mol. One commercial antiglobulin-serum contained 3-6 microgram anti C3d/ml and had a Ko value of 1-7 X 10(8) litres/mol. Values for anti-C3d concentrations measured independently by an indirect method employing 125I-labelled sheep anti-rabbit IgG averaged 20% lower than those obtained with 125I-labelled C3d. Antibody concentrations were correlated with antiglobulin agglutination titres against C3d-coated red cells; a titre of 1 was given by an anti-C3d concentration of 0-5 microgram/ml.