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Biomedical subjects

H E Prince

Publications and source records attributed to H E Prince.

At least 73 records · Page 4Linked to original sources

Azathioprine suppression of natural killer activity and antibody-dependent cellular cytotoxicity in renal transplant recipients.

The relative effects of azathioprine (AZA) and prednisone (PRED) on natural killer (NK) activity and the antibody-dependent cellular cytotoxicity (ADCC) of K (killer) cells and the number of FcR and other lymphoid cells were examined in renal transplant recipients. In addition to both long-term (greater than 6 months) and short-term (less than 6 months) transplant recipients receiving conventional AZA-PRED therapy, an important group of long-term recipients receiving PRED but not AZA was studied for the first time. Both NK activity and ADCC are profoundly reduced in the long-term AZA-PRED group but are normal in the long-term PRED-alone (no-AZA) group. The short-term AZA-PRED group exhibits NK and ADCC levels significantly lower than normal but not as low as those of the long-term AZA-PRED group. Patient groups with low NK and ADCC also have low circulating Fc receptor-bearing (FcR) cells. A single patient in the long-term AZA-PRED group was removed from AZA therapy, and approximately 3 months was required for the patient's suppressed NK and ADCC to return to normal. These findings indicate that AZA rather than PRED is the major drug important in suppressing ADCC and NK activity in renal transplant recipients. Several months are required for combination AZA-PRED therapy to reduce these cytotoxic activities. Similarly, several months are required for suppressed ADCC and NK activity to return to normal upon discontinuation of AZA.

Adolescent↗

Depressed interleukin 2 receptor expression in acquired immune deficiency and lymphadenopathy syndromes.

Because interleukin 2 (IL 2) production and IL 2 receptor (IL 2R) expression are essential steps in T cell proliferation, we undertook to measure these parameters, as defects in one or both seemed likely to account for the reduced proliferative response to mitogen in acquired immune deficiency syndrome (AIDS) and lymphadenopathy syndrome (LAS). Reduced proliferative responses to PHA are a well established feature of AIDS with opportunistic infection (AIDS-OI), AIDS with Kaposi's sarcoma (AIDS-KS), and LAS patient groups. IL 2R expression was significantly reduced in both AIDS groups; a similar trend was observed with the LAS group. Mean levels of IL 2 in culture supernatants for the three patient groups, however, did not significantly differ from controls. IL 2R expression was significantly correlated with proliferation and the Th:Ts ratio in the AIDS-OI and LAS groups, and a good correlation between proliferation and the Th:Ts ratio was also observed. The AIDS-KS group, in contrast, showed no significant correlations between IL 2R expression, proliferation, or Th:Ts ratio. IL 2 levels did not correlate with any of these parameters in any of the patient groups. These findings indicated that poor T cell proliferative responses to mitogen (PHA) are intrinsically related to decreased IL 2R expression in AIDS-OI and LAS. In AIDS-KS, however, a statistically significant correlational relationship between these altered immune parameters is not apparent.

Acquired Immunodeficiency Syndrome↗

Immunological studies of homosexual men with immunodeficiency and Kaposi's sarcoma.

Acquired immunodeficiency and Kaposi's sarcoma are epidemic among homosexual men in the United States. We have identified three clinically distinct disease syndromes in homosexually active men: a syndrome of severe cellular immunodeficiency including infection with Pneumocystis carinii and other opportunistic pathogens, a syndrome of chronic benign lymphadenopathy without severe opportunistic infections, and Kaposi's sarcoma. All 46 patients which we have studied with these three disease syndromes shared a common immune abnormality, that being a reduction in the circulating T-lymphocyte subpopulation bearing the Leu-3/OKT-4 antigen. The second major T-lymphocyte subpopulation, which bears the Leu-2/OKT-8 antigen, was numerically normal in all the disease syndromes, but increased as a percentage of all circulating lymphocytes. These abnormalities resulted in an inversion of the normal ratio of these two lymphocyte subpopulations. A similar, but less pronounced imbalance in circulating T-lymphocyte subpopulations was observed in a group of healthy homosexual men. The immune deficiency in these patients was most evident in the T-cell component of the immune system. Percentages of B cells, circulating immunoglobulin levels, and natural killer (NK) and antibody-dependent cell-mediated cytoxic (ADCC) functions were normal. Proliferative responses to antigen and mitogen were typically decreased in patients with the acquired immunodeficiency syndrome and some Kaposi's sarcoma patients, but not those with the prolonged lymphadenopathy syndrome or a control group of healthy homosexual men. Possible causes or factors contributing to the immunodeficiency and interrelationships among the three disease manifestations are discussed.

Acquired Immunodeficiency Syndrome↗

Airborne fungi--a resurvey.

A 15-month survey of airborne fungi at 14 geographical stations was conducted to determine the incidence of different fungal genera. Five of these stations were surveyed 25 years earlier. A comparison between previous studies and present surveys revealed similar organisms at each station with slight shifts in frequency of dominant genera.

Air Microbiology↗

Inhibition of L-cell growth in agarose (ILGA): a simple inexpensive method for the detection and quantitation of factors inhibiting tumor cell growth.

By taking advantage of the ability of L-929 tumor cells to grow in agarose, we have developed an in vitro method for detecting tumor necrosis factor (TNF), a potent inhibitor of tumor cell growth. When placed in a well cut in agarose containing L-cells, TNF inhibits L-cell growth in the area adjacent to the well. The size of this area of growth inhibition is proportional to the amount of TNF placed in the well. The size of this area of growth inhibition is proportional to the amount of TNF placed in the well. This assay can be used to monitor TNF activity during purification procedures and may also prove useful in the analysis of other factors interfering with tumor cell proliferation.

Animals↗

A comparative analysis of human IgM rheumatoid factor degradation by purified elastase and total granule extracts from human polymorphonuclear leukocytes.

A modified digestion system using radiolabeled IgM rheumatoid factors (RF) and unlabeled IgG was used to examine IgM RF digestion by human polymorphonuclear leukocyte (PMN) elastase. Upon molecular sieve chromatography, the radioactive fragments coelute with fragments produced by elastase digestion of an IgM protein giving no RF activity. The fragments represent an Fab2-like fragment, an Fab-like fragment, and small peptides. Utilizing this same system, digests were performed at both acid and neutral pH to compare the proteolytic action of purified elastase on IgM RF (Ove) to the action of the total granule extract (TGE) from human PMN. At pH 4.5, purified elastase exhibits low-level protease activity, producing a slightly degraded IgM fragment with a molecular weight of about 800,000 daltons. In contrast, TGE at pH 4.5 completely degrades IgM RF to small peptides. At pH 7.5, the fragments produced by TGE digestion of IgM (Ove) coelute with fragments produced by elastase digestion under the same conditions. Thus elastase appears to be the major granule protease active in IgM RF degradation at the pH characterizing the inflammatory site.

Female↗

Interaction of human polymorphonuclear leukocyte (PMN) elastase with human IgM. Production of a factor enhancing PMN migration in vitro.

Digestion in vitro of human monoclonal IgM by human polymorphonuclear leukocyte (PMN) elastase produces small peptides in addition to larger fragments. These small peptides were shown to enhance PMN locomotion in vitro, as tested by the migration-under-agarose assay. The small peptides from elastase degradation of the Fc5u portion of the IgM molecule also increase PMN migration in vitro. The migration-enhancing factor is stable at 60 degrees C for 20 minutes but is inactivated by boiling for 10 minutes, and has a molecular weight which falls between 1,000 and 10,000 daltons.

Cell Movement↗

Proteolysis of human IgG by human polymorphonuclear leucocyte elastase produces an Fc fragment with in vitro biological activity.

The Fc fragment derived by proteolysis of human IgG by human polymorphonuclear leucocyte (PMN) elastase was tested for in vitro biological activity. This fragment could attach to the specific IgG receptor of Staphylococcus aureus Cowan I cells (protein A) and could be eluted from the cells with dissociating buffer. Taking advantage of this attachment, it was shown that the Fc fragment is capable of attaching to the antigen-combining site of an IgM rheumatoid factor and can bind to the Fc receptor of human PMN. A similar fragment produced in vivo at sites of inflammation could play a role in regulating the inflammatory response.

Binding Sites, Antibody↗

An up-to-date look at mold allergy.

The general distribution of the more frequently encountered airborne molds is reviewed. Improved diagnostic and therapeutic mold allergens, a knowledge of botanical relationships among molds and new injection techniques facilitate handling of clinical problems caused by molds.

Allergens↗