Biomedical subjects
J A Pierce
Publications and source records attributed to J A Pierce.
The results of intensive treatment of patients with chronic bronchitis and pulmonary emphysema.
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Preoperative medication and its effect on blood gases.
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Tensile strength of human lung.
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The measurement of contact angles on circular tubing surfaces using the captive bubble technique.
Circular tubings are used extensively in biomedical implants and devices. It is desirable to determine contact angles on the inner or outer surfaces of such tubing in its final fabricated form. In this study, a technique for the measurement of contact angles on tubing surfaces in an aqueous environment is reported. This has particular applications to biomaterials research, where polymer tubings contact the biologic environment. In this technique, air or octane captive bubble dimensions can be measured, and an underwater contact angle calculated from these dimensions. The validity of the technique was experimentally confirmed using Solution Grade Biomer and NIH standard polyethylene surfaces.
Physiological and genetic strategies for enhanced subtilisin production by Bacillus subtilis.
Defined minimal media conditions were used to assess and subsequently enhance the production of subtilisin by genetically characterized Bacillus subtilis strains. Subtilisin production was initiated by the exhaustion or limitation of ammonium in batch and fed-batch cultures. Expression of the subtilisin gene (aprE) was monitored with a chromosomal aprE::lacZ gene fusion. The beta-galactosidase production driven by this fusion reflected subtilisin accumulation in the culture medium. Subtilisin gene expression was temporally extended in sporulation-deficient strains (spoIIG), relative to co-genic sporogenous strains, resulting in enhanced subtilisin production. Ammonium exhaustion not only triggered subtilisin production in asporogenous spoIIG mutants but also shifted carbon metabolism from acetate production to acetate uptake and resulted in the formation of multiple septa in a significant fraction of the cell population. Fed-batch culture techniques, employing the spoIIG strain, were investigated as a means to further extend subtilisin production. The constant provision of ammonium resulted in linear growth, with doubling times of 11 and 36 h in each of two independent experiments. At the lower growth rate, the responses elicited (subtilisin production, glucose metabolism, and morphological changes) during the feeding regime closely approximated the ammonium starvation response, while at the higher growth rate a partial starvation response was observed.
Red cell destruction in the absence of detectable antibody.
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Anti-JMH identified in serum and in eluate from red cells of a JMH-negative man.
Anti-JMH was identified in the serum of an 80-year-old JMH-negative man. Before transfusion, his direct antiglobulin test was weakly positive with polyspecific reagents, anti-C3 and anti-IgG. An eluate prepared from his red cells contained anti-JMH. Chromium-51-labeled JMH-positive cells which were weakly incompatible in vitro appeared to survive normally. Following transfusion with three JMH-positive units, the patient's hematocrit increased from 20.7 percent to 32.1 percent.
Immunological characteristics and clinical significance of anti-H in the Ah phenotype.
A red cell survival study with 51Chromium-labeled A1 cells was performed in a patient with the Ah phenotype whose serum contained IgM anti-H but not anti-A1. A1 cells were agglutinated weakly at 37 degrees C in the crossmatch, but not in the antiglobulin test. One hour after the survival study was begun, 67 percent of injected cells had been destroyed, and only 20 percent of the labeled cells remained after 24 hours. This study suggests that Ah individuals should be transfused only with Ah or Oh red cells.
Low incidence of red cell and HLA antibody formation by bone marrow transplant patients.
BACKGROUND: Bone marrow transplant (BMT) patients, although immunosuppressed, are at risk for the development of red cell (RBC) and HLA antibodies, and they often are given filtered blood in an effort to prevent the latter complication. This study attempts to determine the rate of formation and the specificity of both RBC and HLA alloantibodies in this patient population. STUDY DESIGN AND METHODS: BMT patients (148 received autologous marrow; 45 received allogeneic marrow) from an 18-month period, including patients with leukemia (57 patients), lymphoma (54), breast cancer (68), myeloma (8), myelodysplastic syndrome (5), and aplastic anemia (1), were studied to determine the rate of alloantibody formation to RBC and HLA antigens. A total of 2,410 RBC antibody screens were performed. The patients received 3,921 packed RBCs and 5,915 single-donor platelet units; all were irradiated and administered via white cell-reduction filters. RESULTS: Seven (3.6%) of 193 patients had RBC antibodies upon hospital admission. Four (2.1%) of 193 developed RBC antibodies during the course of BMT: 3 patients had one RBC antibody and 1 patient had two RBC antibodies. RBC antibodies included anti-E (n = 2), anti-M (n = 1), anti-Jkb (n = 1), and anti-Lu14 (n = 1). Thus, 98 percent of patients (189/193) did not develop new (182/186) or additional (7/7) RBC antibodies during BMT. BMT patients were also screened weekly for HLA antibody formation (60-cell panel). Upon admission, 170 (85%) patients were negative. Of these, 8 (4.7%) developed persistent HLA antibodies (mean panel-reactive antibody score, 33 +/- 29%) and 9 (5.3%) were variably positive. Thus, in our setting and population, RBC antibody formation was 0.1 percent per unit transfused, and the HLA alloimmunization rate was 5 to 10 percent. CONCLUSION: As RBC antibody screens are done every Monday, Wednesday, and Friday on this BMT service and as RBC antibody formation is low in these patients, screening for unexpected antibodies might be possible on a more infrequent basis. Also, the rate of HLA alloimmunization in this population receiving filtered blood components is low.