ALBERT

Description: Human erythrocytes (RBC) from whole blood were separated according to their specific densities by centrifugation on a polyvinyl-pyrrolidine- coated colloidal silica matrix (Percoll) into four major subpopulations. By indirect immunofluorescence assay, the most dense RBC subpopulation, with specific density greater than 1.110 g/ml (3%-5% of total RBC), was positive for membrane-bound immunoglobulin; the remaining, less dense subpopulations were negative. IgG was present on 85%-95%, IgM on 28%-32%, and IgA on 15%-20% of the RBC in the most dense population. When these immunoglobulins were eluted, radiolabeled, and used in binding studies with autologous RBC fractions subjected to thermal and/or enzymatic treatment, they reacted specifically with the less dense RBC subpopulations. These results suggest that previously cryptic antigens were revealed by the activity of neuraminidase on the plasma membranes of the treated RBC.

Description: Human erythrocytes (RBC) from whole blood were separated according to their specific densities by centrifugation on a polyvinyl-pyrrolidine- coated colloidal silica matrix (Percoll) into four major subpopulations. By indirect immunofluorescence assay, the most dense RBC subpopulation, with specific density greater than 1.110 g/ml (3%-5% of total RBC), was positive for membrane-bound immunoglobulin; the remaining, less dense subpopulations were negative. IgG was present on 85%-95%, IgM on 28%-32%, and IgA on 15%-20% of the RBC in the most dense population. When these immunoglobulins were eluted, radiolabeled, and used in binding studies with autologous RBC fractions subjected to thermal and/or enzymatic treatment, they reacted specifically with the less dense RBC subpopulations. These results suggest that previously cryptic antigens were revealed by the activity of neuraminidase on the plasma membranes of the treated RBC.

Description: Autologous membrane-bound IgG was isolated from a subpopulation of human red blood cells (RBC) with specific density greater than 1.110, by affinity chromatography of purified RBC membrane glycoprotein preparations using immobilized wheat germ agglutinin and immobilized anti-human immunoglobulin (Ig) as immunoabsorbents. The Ig-containing population thus obtained, when further separated by chromatography on Sephadex G-200 in the presence of chaotropic agents, yielded four peaks (Ia, Ib, II, and III). Double immunodiffusion revealed the presence of Ig in the first three peaks (IgM in peak Ia, IgA in Ib, and IgG in II) but not in peak III. Peak III was precipitated by the Ig-containing peaks (Ia, Ib, and II) in immunodiffusion assays, suggesting that the antigenic membrane determinants responsible for the binding of autologous Ig to senescent human RBC were contained in this peak (III). Peaks Ia, Ib and II precipitate purified asialoglycophorin; peak III was reactive with purified autoantibodies directed against asialoglycophorin. These results suggest that an age-related antigenic determinant(s) present on senescent human RBC is exposed by desialylation of the major sialoglycoprotein component of the RBC membrane.

Description: Autologous membrane-bound IgG was isolated from a subpopulation of human red blood cells (RBC) with specific density greater than 1.110, by affinity chromatography of purified RBC membrane glycoprotein preparations using immobilized wheat germ agglutinin and immobilized anti-human immunoglobulin (Ig) as immunoabsorbents. The Ig-containing population thus obtained, when further separated by chromatography on Sephadex G-200 in the presence of chaotropic agents, yielded four peaks (Ia, Ib, II, and III). Double immunodiffusion revealed the presence of Ig in the first three peaks (IgM in peak Ia, IgA in Ib, and IgG in II) but not in peak III. Peak III was precipitated by the Ig-containing peaks (Ia, Ib, and II) in immunodiffusion assays, suggesting that the antigenic membrane determinants responsible for the binding of autologous Ig to senescent human RBC were contained in this peak (III). Peaks Ia, Ib and II precipitate purified asialoglycophorin; peak III was reactive with purified autoantibodies directed against asialoglycophorin. These results suggest that an age-related antigenic determinant(s) present on senescent human RBC is exposed by desialylation of the major sialoglycoprotein component of the RBC membrane.

Description: Allogeneic HSCT is the only curative intervention for patients with persistent disease or who recur after transplantation; however, these patients are often not considered for HSCT because of their persistent disease or high risk for regimen-related toxicity. We conducted a prospective study for patients who had hematologic malignancies with refractory disease or who relapsed after allogeneic HSCT using mismatched family member donors and a reduced intensity conditioning regimen in an effort to allow GVHD to occur to reduce disease recurrence in this high risk patient population. The conditioning regimen consisted of fludarabine (40 mg/m2/day for 5 days), melphalan (60 mg/m2/day for 2 days), and thiotepa (10 mg/kg/day for one day). One dose of melphalan was omitted in 6 patients who were aplastic at the time of transplantation. OKT3 was administered from day −9 to +17 for prevention of graft rejection. GVHD prophylaxis consisted of MMF initiated on day −2. Rituximab 375 mg/m2 was administered on day 0 as EBV prophylaxis. Patients received G-CSF starting on day +6 until ANC ≥ 2000/mm3 for two consecutive days. Peripheral blood grafts were obtained after mobilization with G-CSF and GM-CSF. Grafts were depleted of T-lymphocytes on the CliniMACS device using the anti-CD3 antibody OKT3. 25 patients were treated in this manner: 10 with refractory disease and 15 requiring another allogeneic HSCT (14 had one prior HSCT, one had 2 prior HSCT). For refractory patients, diagnoses included AML (2 secondary AML, 1 persistent disease (PD)) JMML (n=1, PD), ALL (n=3, PD), and NHL (n=3, PD including one after autologous HSCT). For patients who had failed prior allogeneic HSCT, diagnoses included AML (n=7), ALL (n=7), and CML (n=1, blast crisis). Patients had failed HSCT from matched sibling donors (n=5), unrelated donors (n=5), unrelated cord blood grafts (n=2), and haploidentical parents (n=3). Patients were a median of 11 years old at HSCT (range, 1–26). The median number of CD34+cells/kg infused was 13.64 x 106/kg (range, 2.23–42.46); the median number of CD3+ cells/kg infused was 0.122 x 106/kg (range, 0.006–0.45). Two patients suffered primary graft rejection: one with refractory JMML recovered with persistent disease after OKT3 and a re-infusion of paternal PBSCs. The second underwent infusion of the original unrelated donor cells and engrafted. The 23 evaluable patients had a median time to ANC ≥ 500/mm3 of 10 days (range, 7–12) post-HSCT. One patient undergoing second HSCT developed secondary graft rejection requiring infusion of original sibling donor marrow. 13 patients developed acute GVHD, but only 2 developed grade 3–4 acute GVHD. 5 patients developed chronic GVHD. None developed VOD. Of the refractory patients, 7 died of relapse and 1 of regimen-related toxicity. Of those undergoing subsequent HSCT, 6 died of relapse and 2 of regimen-related toxicity. With a median followup of 472 days, (range, 147–767), 9 remain alive. Transplantation of mismatched related donor PBSC grafts using OKT3 for ex vivo T-cell depletion following a reduced intensity conditioning regimen produces favorable outcomes with acceptable toxicity in this this high-risk patient population.

Description: Biophysical and other ‘outer limits’ of food, land, water, climatic change, stratospheric chemistry, energy, hazardous substances, non-fuel minerals, human stress, and social and ecological stability, raise fundamental questions about present trends in management methods and in global organization. The diverse outer limits surveyed in this paper reflect complex, poorly perceived, and often unsuspected, interconnections between numerous biological and geophysical processes, many of which are obscure or still unknown. Our lack of predictive power, let alone of quantitative understanding, implies a need to treat essential life-support systems with great caution and forbearance, lest we erode safety margins whose importance we do not yet appreciate.Even those outer limits which now seem remote are relevant to present policy, as their timely avoidance may require us to discard otherwise attractive short-term policies in favour of others that offer less immediate advantage but that retain options which may be needed later. Such alternative policies may have to rely more on social than on technical innovation in order to address underlying disequilibria rather than merely palliating their symptoms. Moreover, some outer limits are sufficiently imminent, or require such long lead-times to avoid, that fundamental changes in policy, in institutions, and in the degree of global interdependence, seem necessary if we are to live to enjoy some of the later and more interesting limits to human activity.