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Biomedical subjects

W Borkowsky

Publications and source records attributed to W Borkowsky.

117 records · Page 7Linked to original sources
PubMed1979

Erythrocyte adenosine deaminase deficiency without immunodeficiency. Evidence for an unstable mutant enzyme.

Inherited deficiency of the purine salvage enzyme adenosine deaminase (ADA) gives rise to a syndrome of severe combined immunodeficiency (SCID). We have studied a 2.5-yr-old immunologically normal child who had been found to lack ADA in his erythrocytes during New York State screening of normal newborns. His erythrocytes were not detectably less deficient in ADA than erythrocytes of ADA(-)-SCID patients. In contrast, his lymphocytes and cultured long-term lymphoid cells contained appreciably greater ADA activity than those from patients with ADA(-)-SCID. This residual ADA activity had a normal molecular weight and K(m) but was markedly unstable at 56 degrees C. His residual erythrocytes-ADA activity also appeared to have diminished stability in vivo. ADA activity in lymphoid line cells of a previously reported erythrocyte-ADA-deficient!Kung tribesman was found to contain 50% of normal activity and to exhibit diminished stability at 56 degrees C. ATP content of erythrocytes from both partially ADA-deficient individuals was detectably greater than normal (12.3 and 6.1 vs. normal of 2.6 nmol/ml packed erythrocytes). However, the dATP content was insignificant compared to that found in erythrocytes of ADA(-)-SCID patients (400-1,000 nmol/ml packed erythrocytes). The New York patient, in contrast to normals, excreted detectable amounts of deoxyadenosine, but this was <2% of deoxyadenosine excreted by ADA(-)-SCID patients. Thus, the residual enzyme in cells other than erythrocytes appears to be sufficient to almost totally prevent accumulation of toxic metabolites.

Adenosine↗
PubMed1979

Purine and phosphoribosylpyrophosphate metabolism of lymphocytes and erythrocytes of an adenosine deaminase deficient immunocompetent child.

Purine metabolism and phosphoribosylpyrophosphate content of lymphocytes and erythrocytes were studied in an immunocompetent black male child with a total deficiency of erythrocyte and partial deficiency of lymphocyte adenosine deaminase. The partial genetic deficiency of adenosine deaminase was demonstrated in intact lymphocytes, and was approximately one third of the deaminating activity of control lymphocytes. Intact lymphocytes of the patient did not incorporate adenosine at a faster rate than those of control lymphocytes. The patient's erythrocytes deaminating activity was low and adenine ribonucleotide synthesis from adenosine was increased several fold, while adenine incorporation into purine ribonucleotides was comparable to that of control erythrocytes. Transfusion with packed erythrocytes temporarily improved the deaminating capacity of circulating erythrocytes, but did not reduce the elevated incorporation of adenosine into purine ribonucleotides. Phosphoribosylpyrophosphate content of the patient's lymphocytes and erythrocytes was not diminished. Incubation of erythrocytes with adenosine lowered phosphoribosylpyrophosphate content while incubation with phosphate increased phosphoribosylpyrophosphate content to the same extent in mutant and control erythrocytes.

Adenine Nucleotides↗
PubMed1979

The proliferative response of human lymphocytes to antigen is suppressed preferentially by lymphocytes precultured with the same antigen.

Human blood lymphocytes activated in vitro with antigen to which the donor is reactive are capable of suppressing the secondary proliferative response of autochthonous fresh cells to antigen. Both antigen-specific and antigen-nonspecific suppression can be detected in each experiment. These suppressor cells act by decreasing the number of lymphocytes entering the proliferative response rather than by slowing or otherwise inhibiting ongoing proliferation. The suppressor cells must be added soon after fresh cells are stimulated with antigen to be effective, but the suppressor cells themselves need not proliferate to exert their effect. Suppressor cells are optimally effective when added in numbers equal to those of the responding population, but still exert a significant effect at one-eighth that number.

Antigens↗
PubMedDate not supplied

Live attenuated rubella virus vaccine: comparison of responses to HPV-77-DE5 and RA 27/3 strains.

The responses of seronegative adults to two live attenuated rubella virus vaccines were compared. Of 50 women who received the HPV-77-DE5 strain, 49 (98%) had an antibody response; the geometric mean antibody titer (GMT) was 1:38 at two to five months and 1:59 at six to 14 months. Of 66 women and three men who received the RA 27/3 strain all (100%) had an antibody response; the GMT was 1:55 at two to five months and 1:75 at six to 14 months. The incidence of mild to moderate transient clinical reactions, occurring in approximately one-fourth of those vaccinated, was similar for both groups. The serologic response to both vaccines was excellent.

Adolescent↗
PubMedDate not supplied

IgM to varicella-zoster virus: demonstration in patients with and without clinical zoster.

Antibody to varicella-zoster (VZ) virus of the IgM type was detected in sera from 50% of persons with clinical zoster, 67% of asymptomatic varicella immunes with a recent intimate exposure to VZ virus and 22 to 40% of varicella immunes with no symptoms of zoster or known exposure to the virus. No VZ IgM was found in newborn sera or in sera from persons susceptible to varicella, demonstrating specificity of the VA IgM assay. Since development of specific IgM is associated with acute infection, these data suggest that reinfection with VA virus occurs and also that antigenic stimulation due to exposure to endogenous VZ virus may occur. We hypothesize that during reactivation of VZ virus, persons with intact VZ cell-mediated immunity (CMI) remain asymptomatic but that those with depressed VZ CMI may develop clinical zoster. These data suggest that there is an unstable relationship between VZ virus and the human host.

Adult↗