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P Rubinstein

Publications and source records attributed to P Rubinstein.

At least 55 records · Page 3Linked to original sources
PubMed1994

Variation in expression of porcine xenogeneic antigens.

The rejection of organs transplanted between phylogenetically disparate animals such as pigs and primates is thought to be initiated by binding of naturally occurring antibodies of the recipient to blood vessels in the donor organ. The major porcine target antigens are a triad of glycoproteins, gp115/135, which are expressed on endothelial cells and platelets of all animals tested to date. Whether expression of these antigens varies to the extent that selection of particular animals as donors for xenotransplantation would be warranted is an important question that has not been addressed previously. We tested the reactivity of human natural antibodies with platelet-derived antigens isolated from > 60 pigs representing 4 strains. Reactivity with IgM from a single human serum sample varied to such an extent as to suggest a 5-fold difference in the levels of antigen expression. Significantly, approximately 10% of animals express very low levels of the target antigens. The variations in antigen levels were not due to the age or sex of the animal or to environmental effects. There appears to be genetic regulation of the expression, as sibling pairs were more likely to have similar levels of reactivity than nonsiblings. Western blotting of platelet extracts shows the same quantitative differences in expression of the individual glycoproteins gp115, 125, and 135 as is seen by ELISA for all xenogeneic antigens. The levels of expression of gp115/135 appear to be controlled coordinately and are consistent with genetic regulation. While the clinical relevance of these observations is unclear, it is possible that lower levels of expression of these antigens on donor organs might lead to enhanced xenograft survival. In addition, in the experimental situation, the outcome of particular experiments might be affected by the selection of particular donor-recipient pairs.

Animals↗
PubMed1994

Human immunodeficiency virus type 1 mRNA expression in peripheral blood cells predicts disease progression independently of the numbers of CD4+ lymphocytes.

To address the significance of human immunodeficiency virus (HIV) replication in peripheral blood mononuclear cells (PBMCs), we have used reverse transcriptase-initiated PCR to measure HIV-1 mRNA expression in PBMC specimens collected from a cohort of HIV-infected individuals during a long-term prospective study. We found dramatic differences in HIV mRNA expression among individuals with very similar clinical and laboratory indices, and this variation strongly correlated with the future course of the disease. No evidence of viral replication was detected in PBMCs from asymptomatic individuals who, thereafter, had normal levels of CD4+ cells for at least 5 years. Irrespective of whether the CD4+ cell numbers were normal at the time of sampling, abundant expression of HIV-1 mRNA in PBMCs predicted accelerated disease progression within the next 2 years. Thus, independently of what may be the rate of HIV replication in other viral reservoirs, such as lymphatic tissue, the amount of HIV mRNA in PBMCs appears to reflect the subsequent development of HIV disease. We have also used the reverse transcriptase-initiated PCR assay to demonstrate a transient response to 3'-azido-3'-deoxythymidine treatment. Determination of HIV-1 mRNA expression in the PBMCs of infected individuals could, therefore, have significant clinical utility as a prognostic indicator and as a means to guiding and monitoring antiviral therapies.

CD4-Positive T-Lymphocytes↗
PubMed1994

Umbilical cord blood infusion in a patient for correction of Wiskott-Aldrich syndrome.

A 2 3/4 year old male with thrombocytopenia secondary to Wiskott-Aldrich Syndrome (WAS) and a history of two intracranial hemorrhages as well as hemolytic anemia and neutropenia received a placental blood infusion from an HLA-identical female sibling born by caesarian section at 35 weeks gestation. The patient was prepared with Thiotepa and Cytoxan and received a nucleated cell dose of 3.0 x 10(7)/kg. Cyclosporin A and Methylprednisolone was given for graft versus host disease (GVHD) prophylaxis. An ANC of 0.5 x 10(9)/L and 1.0 x 10(9)/L were achieved on post-transplant days 18 and 28, respectively. Platelet recovery was rapid with a platelet count > or = 100 x 10(9)/L on day +39. On posttransplant day +11, the patient developed an erythematous rash consistent with grade I acute GVHD that resolved without therapy. He was discharged day on +60 and has remained free of infections with a normal platelet count off all immunosuppression therapy 30+ months post-transplantation. Chimerism studies performed on peripheral blood mononuclear cells by fluorescent in situ hybridization indicated that the percentage of donor cells ranged between 55 and 80%. The phenotype and function of peripheral blood lymphocytes are completely normal and the patient has responded in vivo with production of antibodies to both diphtheria and tetanus immunizations. This study demonstrates the feasibility of collecting placental blood after a multiple birth delivery and the ability of umbilical cord blood to provide complete hematopoietic and immunologic reconstitution in a patient with WAS.

Antibodies, Bacterial↗
PubMed1994

The use of umbilical cord blood in mismatched related and unrelated hemopoietic stem cell transplantation.

Over the past 6 years, umbilical cord blood has emerged as an efficacious alternative source of hematopoietic stem cells in related bone marrow transplantation. These encouraging results led us to extend this technology to the mismatched related and unrelated settings in three high-risk leukemic children lacking a matched-related donor for transplantation. Two of the three children also lacked identifiable donors through the National Marrow Donor Program, while the third was in relapse and did not have time to wait for completion of a search. The first child was transplanted with haploidentical umbilical cord blood-derived mononuclear cells from his sister, while the remaining two children were transplanted with partially mismatched, unseparated, unrelated umbilical cord blood banked through the Placental Blood Project at the New York Blood Center. All three children demonstrated trilineage engraftment with donor cells within 6 weeks of transplantation. The patient transplanted with haploidentical marrow developed grade 2 graft vs. host disease (GVHD), which was controlled with steroid and anti-thymocyte globulin (ATG) therapy. One of the two patients grafted with unrelated umbilical cord blood developed mild grade 1 GVHD of the skin, which rapidly cleared with steroid therapy. One patient remains alive, in good health and disease-free 12 months from transplantation.

Acute Disease↗
PubMed1994

Unrelated placental blood for bone marrow reconstitution: organization of the placental blood program.

The usefulness of placental/umbilical cord blood as a source of stem cells for marrow reconstitution of HLA-matched siblings has now been extended to the unrelated-donor setting. The need for HLA-matched donor tissue makes it essential to have available a frozen inventory of ready-to-use placental blood units. The New York Blood Center's Placental Blood Project, designed to evaluate the practical feasibility of unrelated placental blood transplantation, consists of four basic modules: collection of placental blood, maternal samples and donor data, accession and testing for genetic and infectious disease markers, freezing placental blood units, and data organization and retrieval. Additional modules include a computerized HLA matching algorithm and organization of data about patients requiring transplantation, which may be best taken up by organ-sharing organizations in the future. In this report, we describe the organization and discuss the methods and overall experience after collecting the first 1,000 units and supplying the tissue for the first two unrelated-donor placental blood transplants.

Adult↗
PubMed1994

Collection, separation and cryopreservation of umbilical cord blood for use in transplantation.

Bone marrow transplantation (BMT) is limited by the paucity of HLA-matched donors and the frequent occurrence of graft-versus-host disease (GVHD). Recent clinical reports have implied that the use of umbilical cord blood (UCB) may alleviate some of the problems associated with BMT. Banks of frozen UCB could make the problem of finding suitable stem cell donors easier and stem cell grafts would be more readily available. However, definitive experiments are needed to develop optimal methods for collection, separation and storage of cryopreserved UCB for extended periods of time. We have found that several simple techniques may be utilized to collect large volumes of UCB (up to 220 ml). Also, modification of a common density gradient separation method permits recovery of large quantities of UCB mononuclear cells. Finally, we have examined the effects of prolonged frozen storage on the ability to recover viable and functional UCB, particularly stem/progenitor cells. It was observed that storage of UCB in liquid nitrogen for as long as 7 years had minimal effects on cell viability, cellular composition of UCB and progenitor/stem cell capacity. Thus, the establishment of UCB banks for use in transplantation appears to be a feasible approach.

Blood Banks↗
PubMed1993

Regulation by heparan sulfate and interleukin 1 alpha of the ontogenic expression of T-cell receptor, CD4, and CD8 in developing thymus.

Increasing expression by T-cell precursors of the T-cell antigen receptor and of the CD4 and CD8 glycoproteins during thymus development enables specific interactions between primitive T cells and thymic epithelial cells, which initiate the development of the T-cell repertoire. Given the importance of GAGs, such as HS, in cell-cell interactions in other organs, we asked whether such molecules might participate in the cellular interactions essential for the development of the thymus. Using an organ culture model in which fetal murine thymuses explanted on gestational day 14 undergo phenotypic maturation from CD3-CD4-CD8- to CD3+CD4+/CD8+, the consequences of inhibiting GAG synthesis with 6-diazo-5-oxo-L-norleucine (DON) were explored. Inhibition of GAG synthesis prevented elaboration of cortical thymocyte-associated HS, IL-1, and de novo expression of the TCR, CD4, and CD8. DON did not alter the expression of TCR or CD4/CD8 by mature thymocytes. Synthesis of IL-1 alpha, TCR, CD4, and CD8 was restored by addition of HS to the cultured organs. These findings support the concept that the ontogenic (but not the constitutive) expression of the TCR and of CD4 and CD8 depends on the synthesis in the thymus of IL-1, and that IL-1 synthesis is in turn regulated by the metabolism of GAGs. Our findings suggest that components of the thymic microenvironment, particularly HS, play a critical role in the maturation of T-cell precursors.

Animals↗
PubMed1993

Placental blood-derived hematopoietic stem cells for unrelated bone marrow reconstitution.

"Transplants" of placental blood from siblings have been successful in the reconstitution of ablated bone marrow. We are currently evaluating the feasibility of applying this source of hematopoietic stem cells in the case of unrelated recipients. Availability, ease and low cost of recovery, absence of risk to the donors, unbiased ethnic participation, and possibly advantageous immunological and infectious disease characteristics are evident advantages in comparison to registries of volunteer marrow donors. In this report we review selected aspects of the comparison and discuss selected areas of special interest to the practical application of this source of stem cells. We also present new data that reinforce earlier suggestions of a reduced capacity of allorecognition of placental blood lymphocytes, using as controls the lymphocytes of their respective HLA-identical siblings.

Adult↗
PubMed1992

Growth characteristics and expansion of human umbilical cord blood and estimation of its potential for transplantation in adults.

We estimated whether single collections of cord blood contained sufficient cells for hematopoietic engraftment of adults by evaluating numbers of cord blood and adult bone marrow myeloid progenitor cells (MPCs) as detected in vitro with steel factor (SLF) and hematopoietic colony-stimulating factors (CSFs). SLF plus granulocyte-macrophage (GM)-CSF detected 8- to 11-fold more cord blood GM progenitors [colony-forming units (CFU)-GM] than cells stimulated with GM-CSF or 5637 conditioned medium (CM), growth factors previously used to estimate cord blood CFU-GM numbers. SLF plus erythropoietin (Epo) plus interleukin 3 (IL-3) enhanced detection of cord blood multipotential (CFU-GEMM) progenitors 15-fold compared to stimulation with Epo plus IL-3. Under the same conditions, bone marrow CFU-GM and CFU-GEMM were only enhanced in detection 2- to 4- and 6- to 8-fold. Increased detection of cord blood CFU-GEMM correlated directly with decreased detection of cord blood erythroid burst-forming units (BFU-E). In contrast, adult bone marrow CFU-GEMM and BFU-E numbers were both enhanced by SLF plus Epo plus IL-3. This suggests that most cord blood BFU-E may actually be CFU-GEMM. Cord blood collections (n = 17) contained numbers of MPCs (especially CFU-GM) similar to the number found in nine autologous bone marrow collections. To assess additional sources of MPCs, the peripheral blood of 1-day-old infants was assessed. However, average concentrations of MPCs circulating in these infants were only 30-46% that in their cord blood. Expansion of cord blood MPCs was also evaluated. Incubation of cord blood cells for 7 days with SLF resulted in 7.9-, 2.2-, and 2.7-fold increases in numbers of CFU-GM, BFU-E, and CFU-GEMM compared to starting numbers; addition of a CSF with SLF resulted in even greater expansion of MPCs. The results suggest that cord blood contains a larger number of early profile MPCs than previously recognized and that there are probably sufficient numbers of cells in a single cord blood collection to engraft an adult. Although the expansion data must be considered with caution, as human marrow repopulating cells cannot be assessed directly, in vitro expansion of cord blood stem and progenitor cells may be feasible for clinical transplantation.

Age Factors↗
PubMed1992

Effect of duration of hepatitis B virus infection on the association between human immunodeficiency virus type-1 and hepatitis B viral replication.

This study examined the effect of duration of hepatitis B virus infection on the association between human immunodeficiency virus type-1 infection and hepatitis B viral replication. Twenty-five chronic HBsAg carriers were studied. Presence of hepatitis B virus DNA and expression of HBeAg were more frequent among 20 chronic HBsAg carriers positive for human immunodeficiency virus type-1 antibody compared with five chronic HBsAg carriers negative for human immunodeficiency virus type-1 antibody, but the associations were not statistically significant. Hepatitis B virus DNA and HBeAg were inversely related to duration of hepatitis B virus infection (p less than 0.001). Stratifying for duration of hepatitis B virus infection, the presence of viral replication was similar among patients negative and positive for antibody to human immunodeficiency virus type-1. Hepatitis B virus DNA levels did not increase with the decline of cellular immunity over time. In conclusion, hepatitis B virus replication among chronic carriers may be a function of duration of hepatitis B virus infection rather than of an effect of human immunodeficiency virus type-1.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Genetics of autoimmune thyroid disease: lack of evidence for linkage to HLA within families.

Clinical and epidemiologic observations, including the association of Graves' disease (GD) and Hashimoto's thyroiditis (HT) with the HLA gene complex, support a role for specific disease-related genes in the development of autoimmune thyroid disease (AITD). The combination of HLA and immunoglobulin heavy chain allotypes (Gm) has previously been reported to be predictive of AITD in multiply affected Japanese families. We have investigated the immunogenetics of AITD in families in the United States. Twenty-seven pedigrees including 15 with GD, 8 with HT, and 4 with both HT and GD were immunogenetically typed and analyzed for population and within family disease associations. The majority of families (63%) were multiplex for AITD. HLA-DR3 was increased in affected family members with GD and HLA-DR5 was increased in affected family members with HT. Formal linkage analysis was applied to test for coinheritance of disease with the HLA locus within families. The LIPED computer program was used to calculate the probability of linkage in terms of the lod score. Evidence from linkage analysis was consistently against linkage of either GD or HT to the HLA region under various penetrances and different modes of inheritance. The combination of HLA and Gm was not found to be predictive of disease in 7 selected multiplex families with multigenerational instances of AITD. T cell function was also examined in 3 pairs of siblings genetically identical for HLA and Gm but discordant for disease expression. We found no evidence of a global T cell defect in the small number of patients examined. We conclude that whereas there is an association of AITD with the HLA region, our linkage analysis demonstrates that alleles of the HLA region are not cosegregating with either GD or HT within these families. Thus, whereas HLA may increase susceptibility to AITD, as shown by the existence of an HLA association, the major genetic influence on the inheritance of AITD must be at another locus.

B-Lymphocytes↗
PubMed1991

HLA and IDDM: facts and speculations on the disease gene and its mode of inheritance.

1. The mode of inheritance of the DR3- and DR4-associated susceptibility genotype is essentially recessive, based on both the segregation data and the existence of Hardy-Weinberg equilibrium in Ashkenazi Jewish and possibly in patients of other populations. 2. Maternal effects may alter the expressivity of IDDM in some susceptible offspring, depending on the maternal DR genotype. Thus, the number of susceptible DR4 types inherited from the mothers may be decreased in certain population samples. Conceivably, these maternal effects also account for the smaller proportion of diabetic children born to diabetic women than to diabetic men. Conversely, maternal DRw6 may raise this risk. 3. The locus of the susceptibility gene is most likely in the DQ region. While specific DQA1 and DQB1 alleles are very closely associated with IDDM in some populations, neither is completely associated with it in DR4 haplotypes and neither accounts for the differences in IDDM susceptibility associated with DR3 haplotypes. 4. Linkage disequilibrium between DR and DP alleles in affected haplotypes indicates the existence of subsets of DR3 and DR7, which account for all or most of the risk to those haplotypes. The possibility of direct DP effects is less likely because the respective DP alleles are different and because DR4 does not maintain disequilibrium with DP alleles in either affected or unaffected haplotypes. 5. The DQA2-BglII-7.2Kb polymorphism in complete association with affected B8,DR3 haplotypes suggests the possible involvement of DQA2.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗
PubMed1990

Search for epitope-specific antibody responses to the human immunodeficiency virus (HIV-1) envelope glycoproteins signifying resistance to disease development.

It is essential for the development of strategies for prevention and therapy of human immunodeficiency virus (HIV-1) infections to define host factors playing a dominant role in determining the clinical outcome of infection. Antibodies directed against restricted regions of the HIV-1 glycoproteins gp120 and gp41 are likely to represent important factors involved in host defense against HIV-1. Definition of qualitative and quantitative differences in the spectrum of anti-gp120 and anti-gp41 antibodies between two vastly different groups of HIV-1-infected individuals, long-term asymptomatic carriers, and individuals with acquired immunodeficiency syndrome (AIDS) who died, might reveal the epitope specificity of antibodies contributing to prevention of clinical disease. To accomplish this goal, sera from both groups were assayed for antibodies recognizing synthetic peptides from gp120/gp41 which were shown in earlier experiments to mimic epitopes on the two HIV-1 glycoproteins. None of the sera recognized all of the distinct 27 peptides from gp120 and gp41. The spectrum of antibodies was distinct for each of the sera from both groups of HIV-1-infected individuals. Nevertheless, antibody responses distinguishing the two groups from each other were discerned. In particular, it was possible to predict the unfavorable outcome of disease by comparative measurements of levels of antibodies to a peptide (303-338), corresponding to the entire V3 hypervariable loop of gp120 and/or by providing evidence for declining levels of these antibodies during the course of infection. Antibodies recognizing additional peptides [(219-245), (280-306), (425-452), (658-682), (729-758), (808-845), and (845-862)] were significantly less prevalent in AIDS patients than in asymptomatic carriers. It appears possible that maintenance of high levels of the respective antibodies would contribute to preventing AIDS in HIV-1-infected individuals. Active immunization with antigens containing epitopes defined by the respective peptides and/or administration of the corresponding antibodies may be considered as a modality for therapy of HIV-1 infections.

Epitopes↗
PubMed1990

Amplification of T cell blastogenic responses in healthy individuals and patients with acquired immunodeficiency syndrome.

Human immunodeficiency virus (HIV) infection is associated with a profound impairment of T cell function. Hence, enhancement of T cell reactivity to viral and bacterial antigens is important in the treatment of patients with AIDS. To develop tools for amplifying T cell reactivity, we have immunized mice with human helper T cell clones and selected monoclonal antibodies (MAbs) that enhance in vitro blastogenic responses. MAb NDA5, which recognizes the leukocyte common antigen CD45, amplifies human T cell responses to mitogens and soluble antigens including HIV-1 glycoprotein (gp)-120 and peptides derived from the HIV-1 gp-120 sequence. In the presence of MAb NDA5, peripheral blood mononuclear cells (PBMC) from healthy, HIV-1-seronegative individual displayed augmented blastogenic responses to HIV-1 gp-120 and to HIV-1 gp-120 synthetic peptides. In vitro memory responses to various vaccines and to alloantigens were also enhanced in cultures with MAb. Similarly, the response of PBMC from AIDS patients to pokeweed mitogen, HIV-1 gp-120, and tetanus toxoid was enhanced with MAb NDA5. The finding that the in vitro immune response of patients with AIDS can be amplified with MAb NDA5, suggests that the in vivo immune response of immunodeficient individuals can also be enhanced.

Acquired Immunodeficiency Syndrome↗
PubMed1990

No excess of DR*3/4 in Ashkenazi Jewish or Hispanic IDDM patients.

The gene frequencies, haplotype relative risks, and zygotic assortments of HLA-DR in three ethnically defined samples of insulin-dependent diabetes mellitus (IDDM) patients were determined in a prospective family study. Although DR3 and DR4 were positively associated with IDDM in the probands of 123 northern European, 94 Ashkenazi Jewish, and 49 New York Hispanic families, significant excess of DR*3/4 heterozygotes was observed only among the probands from families of northern European ancestry. There was also a significant decrease in the frequency of Bw62,DR4 haplotypes derived by northern European patients from their mothers compared with their fathers. This difference, together with data reported in the literature, suggests that the expressivity of the susceptible genotype(s) in IDDM patients may be modified by protective maternal effects associated with Bw62,DR4 and probably other DR4 haplotypes. Samples of IDDM patients from populations with high frequencies of these modifiers should have different DR-gene frequencies contributed by fathers and mothers, capable of accounting for the observed Hardy-Weinberg disequilibrium. We postulate that, because the mechanism of action of these modifiers is distinct from that of the susceptibility gene, the difference must be considered in devising strategies for elucidation of the mode of inheritance of the disease and for understanding the molecular nature of the susceptibility.

Diabetes Mellitus, Type 1↗