Chromosome analysis of lymphocytes from patients who had been exposed to arsenic showed frequent structural and numerical aberrations, even with an interval of decades since the last exposure. The in vitro addition of sodium arsenate induced the same chromosome changes--even to extreme of chromosome pulverizations--upon lymphocyte cultures from healthy subjects. Radioactive incorporation studies showed that arsenate was able to inhibit dose-dependently the incorporation of radioactively labeled nucleotide in RNA and DNA. Beyond that, arsenic blocked the cells in the S- and G2-phase. A general explanation for the inhibitory effect of inorganic arsenic on cell metabolism is the known strong affinity of arsenic to enzymes, especially to those containing sulfhydryl groups.ImagesFIGURE 2. aFIGURE 2. bFIGURE 2. cFIGURE 3. aFIGURE 3. bFIGURE 4.
The exposure of Thomsen-Friedenreich (T) antigens on RBCs, serum neuraminidase, and serum hemoglobin levels were investigated in 53 adult surgical intensive care unit (ICU) patients with septicemia. Unmasked T-antigens were assayed by a hemagglutination test using peanut agglutinin (PNA) (direct anti-T test), and by an indirect anti-T test employing rabbit anti-PNA globulin. RBC T-activation was demonstrated in 17/53 patients (32%); in 2/53 patients (4%) the direct anti-T test was positive, indicating strong T-exposure. No polyagglutination phenomena were observed. Serum neuraminidase was elevated in 12/17 (71%) patients with T-activation and in 7/36 (19%) patients without T-activation. Free serum hemoglobin was elevated in 12/17 (71%) patients with T-activation and in 5/36 (14%) patients without T-activation. Correlations between T-activation and serum neuraminidase and between T-activation and serum hemoglobin were significant (p less than 0.001). Potentially neuraminidase-releasing bacteria were demonstrated in 13/17 (76%) patients with RBC T-exposure. We conclude that neuraminidase-induced RBC T-activation and subsequent hemolysis may be involved in the pathomechanism of hemolytic anemia in patients with severe infections.
Antibodies directed against specific human Ia-type antigens can easily be detected and quantitated by an improved radioimmunoassay using iodinated protein A bound to a specific antibody-Ia-antigen complex on the surface of freshly drawn peripheral human leukocytes, cultured human cell lines, or lymphoid cells fixed with glutardialdehyde or formaldehyde. The same principle can also be used for the detection of Ia alloantigens on human lymphocytes when testing them with specific antisera known to contain antibodies against transplantation antigens. These anti-Ia-alloantigen antibodies had been purified by a two-step procedure involving ion-exchange chromatography on DEAE-cellulose at pH 6.3 and the specific absorption on formaldehyde-fixed Ia-alloantigen-carrying homozygous cell lines, followed by elution of these antibodies with isotonic citrate buffer at pH 3.0. In this way an about 90-fold purification could be achieved. After such a purification the highly enriched antibody fraction still reacted selectively with one specificity of the Ia antigen system.
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