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P Rubinstein

Publications and source records attributed to P Rubinstein.

At least 19 recordsLinked to original sources
PubMed2006

Comparative quantification of umbilical cord blood CD34+ and CD34+ bright cells using the ProCount-BD and ISHAGE protocols.

The total number of CD34+ cells is the most relevant clinical parameter when selecting human umbilical cord blood (HUCB) for transplantation. The objective of the present study was to compare the two most commonly used CD34+ cell quantification methods (ISHAGE protocol and ProCount - BD) and analyze the CD34+ bright cells whose 7-amino actinomycin D (7AAD) analysis suggests are apoptotic or dead cells. Twenty-six HUCB samples obtained at the Placental Blood Program of New York Blood Center were evaluated. The absolute numbers of CD34+ cells evaluated by the ISHAGE (with exclusion of 7AAD+ cells) and ProCount (with exclusion of CD34+ bright cells) were determined. Using the ISHAGE protocol we found 35.6 +/- 19.4 CD34+ cells/microL and with the ProCount method we found 36.6 +/- 23.2 CD34+ cells/microL. With the ProCount method, CD34+ bright cell counts were 9.3 +/- 8.2 cells/microL. CD34+ bright and regular cells were individually analyzed by the ISHAGE protocol. Only about 1.8% of the bright CD34+ cells are alive, whereas a small part (19.0%) is undergoing apoptosis and most of them (79.2%) are dead cells. Our study showed that the two methods produced similar results and that 7AAD is important to exclude CD34 bright cells. These results will be of value to assist in the correct counting of CD34+ cells and to choose the best HUCB unit for transplantation, i.e., the unit with the greatest number of potentially viable stem cells for the reconstitution of bone marrow. This increases the likelihood of success of the transplant and, therefore, the survival of the patient.

Antigens, CD34↗
PubMed2005

Immunophenotype of hematopoietic stem cells from placental/umbilical cord blood after culture.

Identification and enumeration of human hematopoietic stem cells remain problematic, since in vitro and in vivo stem cell assays have different outcomes. We determined if the altered expression of adhesion molecules during stem cell expansion could be a reason for the discrepancy. CD34+CD38- and CD34+CD38+ cells from umbilical cord blood were analyzed before and after culture with thrombopoietin (TPO), FLT-3 ligand (FL) and kit ligand (KL; or stem cell factor) in different combinations: TPO + FL + KL, TPO + FL and TPO, at concentrations of 50 ng/mL each. Cells were immunophenotyped by four-color fluorescence using antibodies against CD11c, CD31, CD49e, CD61, CD62L, CD117, and HLA-DR. Low-density cord blood contained 1.4 +/- 0.9% CD34+ cells, 2.6 +/- 2.1% of which were CD38-negative. CD34+ cells were isolated using immuno-magnetic beads and cultured for up to 7 days. The TPO + FL + KL combination presented the best condition for maintenance of stem cells. The total cell number increased 4.3 +/- 1.8-fold, but the number of viable CD34+ cells decreased by 46 +/- 25%. On the other hand, the fraction of CD34+CD38- cells became 52.0 +/- 29% of all CD34+ cells. The absolute number of CD34+CD38- cells was expanded on average 15 +/- 12-fold when CD34+ cells were cultured with TPO + FL + KL for 7 days. The expression of CD62L, HLA-DR and CD117 was modulated after culture, particularly with TPO + FL + KL, explaining differences between the adhesion and engraftment of primary and cultured candidate stem cells. We conclude that culture of CD34+ cells with TPO + FL + KL results in a significant increase in the number of candidate stem cells with the CD34+CD38- phenotype.

ADP-ribosyl Cyclase 1↗
PubMed2001

Peptides from the amino terminal mdm-2-binding domain of p53, designed from conformational analysis, are selectively cytotoxic to transformed cells.

We have synthesized three peptides from the mdm-2 binding domain of human p53, residues 12-26 (PPLSQETFSDLWKLL), residues 12-20, and 17-26. To enable transport of the peptides across the cell membrane and at the same time to maximize the active mdm-2 binding alpha-helical conformation for these peptides, each was attached at its carboxyl terminus to the penetratin sequence, KKWKMRRNQFWVKVQRG, that contains many positively charged residues that stabilize an alpha-helix when present on its carboxyl terminal end. All three peptides were cytotoxic to human cancer cells in culture, whereas a control, unrelated peptide attached to the same penetratin sequence had no effect on these cell lines. The same three cytotoxic peptides had no effect on the growth of normal cells, including human cord blood-derived stem cells. These peptides were as effective in causing cell death in p53-null cancer cells as in those having mutant or normal p53. Peptide-induced cell death is not accompanied by expression of apoptosis-associated proteins such as Bax and waf(p21). Based on these findings, we conclude that the antiproliferative effects of these p53-derived peptides are not completely dependent on p53 activity and may prove useful as general anticancer agents.

Amino Acid Sequence↗
PubMed2001

Hematopoietic engraftment and survival in adult recipients of umbilical-cord blood from unrelated donors.

BACKGROUND: Umbilical-cord blood from unrelated donors who are not HLA-identical with the recipients can restore hematopoiesis after myeloablative therapy in children. We studied the use of transplantation of umbilical-cord blood to restore hematopoiesis in adults. METHODS: Sixty-eight adults with life-threatening hematologic disorders received intensive chemotherapy or total-body irradiation and then transplants of HLA-mismatched umbilical-cord blood. We evaluated the outcomes in terms of hematologic reconstitution, the occurrence of acute and chronic graft-versus-host disease (GVHD), relapses, and event-free survival. RESULTS: Of the 68 patients, 48 (71 percent) received grafts of umbilical-cord blood that were mismatched for two or more HLA antigens. Of the 60 patients who survived 28 days or more after transplantation, 55 had neutrophil engraftment at a median of 27 days (range, 13 to 59). The estimated probability of neutrophil recovery in the 68 patients was 0.90 (95 percent confidence interval, 0.85 to 1.0). The presence of a relatively high number of nucleated cells in the umbilical-cord blood before it was frozen was associated with faster recovery of neutrophils. Severe acute GVHD (of grade III or IV) occurred in 11 of 55 patients who could be evaluated within the first 100 days after transplantation. Chronic GVHD developed in 12 of 33 patients who survived for more than 100 days after transplantation. The median follow-up for survivors was 22 months (range, 11 to 51). Of the 68 patients, 19 were alive and 18 of these (26 percent) were disease-free 40 months after transplantation. The presence of a high number of CD34+ cells in the graft was associated with improved event-free survival (P=0.05). CONCLUSIONS: Umbilical-cord blood from unrelated donors can restore hematopoiesis in adults who receive myeloablative therapy and is associated with acceptable rates of severe acute and chronic GVHD.

Acute Disease↗
PubMed2001

Comparison of outcomes of unrelated bone marrow and umbilical cord blood transplants in children with acute leukemia.

In order to compare the outcomes of unrelated umbilical cord blood transplants (UCBTs) or bone marrow transplants, 541 children with acute leukemia (AL) transplanted with umbilical cord blood (n = 99), T-cell-depleted unrelated bone marrow transplants (T-UBMT) (n = 180), or nonmanipulated (UBMT) (n = 262), were analyzed in a retrospective multicenter study. Comparisons were performed after adjustment for patient, disease, and transplant variables. The major difference between the 3 groups was the higher number in the UCBT group of HLA mismatches (defined by serology for class I and molecular typing for DRB1). The donor was HLA mismatched in 92% of UCBTs, in 18% of UBMTs, and in 43% of T-UBMTs (P <.001). Other significant differences were observed in pretransplant disease characteristics, preparative regimens, graft-versus-host disease (GVHD) prophylaxis, and number of cells infused. Nonadjusted estimates of 2-year survival and event-free survival rates were 49% and 43%, respectively, in the UBMT group, 41% and 37% in the T-UBMT group, and 35% and 31% in the UCBT group. After adjustment, differences in outcomes appeared in the first 100 days after the transplantation. Compared with UBMT recipients, UCBT recipients had delayed hematopoietic recovery (Hazard ratio [HR] = 0.37; 95% confidence interval [95CI]: 0.27-0.52; P <.001), increased 100 day transplant-related mortality (HR = 2.13; 95CI: 1.20-3.76; P <.01) and decreased acute graft-versus-host disease (aGVHD) (HR = 0.50; 95CI: 0.34-0.73; P <.001). T-UBMT recipients had decreased aGVHD (HR = 0.25; 95CI: 0.17-0.36; P <.0001) and increased risk of relapse (HR = 1.96; 95CI: 1.11-3.45; P =.02). After day 100 posttransplant, the 3 groups achieved similar results in terms of relapse. Chronic GVHD was decreased after T-UBMT (HR = 0.21; 95CI: 0.11-0.37; P <.0001) and UCBT (HR = 0.24; 95CI: 0.01-0.66; P =.002), and overall mortality was higher in T-UBMT recipients (HR = 1.39; 95CI: 0.97-1.99; P <.07). In conclusion, the use of UCBT, as a source of hematopoietic stem cells, is a reasonable option for children with AL lacking an acceptably matched unrelated marrow donor.

Analysis of Variance↗
PubMed2001

[Spontaneous bacterial peritonitis in hepatic cirrhosis with ascites: incidence, bacteriology and mortality in Uruguay].

Spontaneous bacterial peritonitis (SBP) is a frequent and severe complication of cirrhotic patients with ascites. In order to analyze the incidence, bacteriology and in-hospital mortality, we studied 64 consecutive patients with cirrhosis and ascites (47 males, 17 females average age 59 years) hospitalized in a general adults 3rd level hospital (Pasteur hospital, Montevideo, Uruguay), between September 1998 and May 2000. The diagnostic criteria was more than 250 polymorphonuclear cells/cu.mm. in ascitic fluid and/or a positive culture. We found 17 SBP in 17 patients (10 males 24-81 years) which means an incidence of 26.56%. 15 alcoholic cirrhosis and 2 autoimmune disease. 12% (2/17) were asymptomatic; 8/17 were SBP culture positive (5 E. Coli, 2 St. Pneumoniae, 1 Klebsiella sp.), and 9 were culture negative. The mortality rate associated with SBP was 47% (8/17), greater than the cirrhotic group without SBP (12.7% p < 0.01).

Adult↗
PubMed2000

Cell dose and speed of engraftment in placental/umbilical cord blood transplantation: graft progenitor cell content is a better predictor than nucleated cell quantity.

There is evidence that the total cellular content of placental cord blood (PCB) grafts is related to the speed of engraftment, though the total nucleated cell (TNC) dose is not a precise predictor of the time of neutrophil or platelet engraftment. It is important to understand the reasons for the quantitative association and to improve the criteria for selecting PCB grafts by using indices more precisely predictive of engraftment. The posttransplant course of 204 patients who received grafts evaluated for hematopoietic colony-forming cell (CFC) content among 562 patients reported previously were analyzed using univariate and multivariate life-table techniques to determine whether CFC doses predicted hematopoietic engraftment speed and risk for transplant-related events more accurately than the TNC dose. Actuarial times to neutrophil and platelet engraftment were shown to correlate with the cell dose, whether estimated as TNC or CFC per kilogram of recipient's weight. CFC association with the day of recovery of 500 neutrophils/microL, measured as the coefficient of correlation, was stronger than that of the TNC (R = -0.46 and -0.413, respectively). In multivariate tests of speed of platelet and neutrophil engraftment and of probability of posttransplantation events, the inclusion of CFC in the model displaced the significance of the high relative risks associated with TNC. The CFC content of PCB units is associated more rigorously with the major covariates of posttransplantation survival than is the TNC and is, therefore, a better index of the hematopoietic content of PCB grafts. (Blood. 2000;96:2717-2722)

Adolescent↗
PubMed2000

The frequency and proliferative potential of megakaryocytic colony-forming cells (Meg-CFC) in cord blood, cytokine-mobilized peripheral blood and bone marrow, and their correlation with total CFC numbers: implications for the quantitation of Meg-CFC to predict platelet engraftment following cord blood transplantation.

CFC numbers have shown to correlate with success of engraftment and speed of neutrophil recovery following cord blood (CB) transplantation. To investigate whether the number of Meg-CFC in a CB stem cell preparation might correlate with time to platelet engraftment, we evaluated the frequency of Meg-CFC among all CFC types in 134 CB, 21 adult bone marrow (BM) and 52 cytokine-mobilized peripheral blood (PB) stem cell preparations. The correlation of Meg-CFC with the total number of CFC and mixed cell-CFC was also assessed. The frequency of Meg-CFC was highest in CB and correlated significantly with total CFC numbers (mean 20.8%, correlation coefficient (r) 0.84, P = 0.0001) compared with Meg-CFC from mobilized PB (mean 13.1%, r = 0.29, P = 0.07) and BM (mean 4%, r = 0. 39, P = 0.13). In addition, mixed-cell CFC numbers in CB were highly correlated with the total number of Meg-CFC (r = 0.7, P = 0.0001). No such correlations were found with mobilized PB or BM. We conclude that, based on the high degree of correlation between Meg-CFC and non-Meg-CFC numbers in CB, no additional information concerning time to platelet engraftment would be gained by routinely performing Meg-CFC assays in addition to non-Meg-CFC assays. The fact that CB Meg-CFC and mixed-cell CFC are strongly correlated suggests that CB Meg-CFC are more primitive than their counterparts in BM and PB and may reflect the number of stem cells in CB. Bone Marrow Transplantation (2000).

Adult↗
PubMed2000

Graft-versus-leukemia-induced complete remission following unrelated umbilical cord blood transplantation for acute leukemia.

A 15-year-old female received an unrelated three of six HLA antigen matched umbilical cord blood (UCB) transplant for refractory, relapsed T-cell ALL. Conditioning consisted of TBI, melphalan, and anti-thymocyte globulin (ATG), with cyclosporin A (CsA) and solumedrol for GVHD prophylaxis. She engrafted and a day 34 bone marrow aspirate showed 100% donor cells and no evidence of leukemia. The post-transplant course was complicated by mild grade I acute GVHD involving skin, and limited chronic GVHD of the gut which resolved with the addition of 1 mg/kg/day of steroids to her CsA prophylaxis. One hundred and ninety days after transplantation the patient developed pancytopenia and was subsequently found to have a leukemic relapse. Immunosuppression was discontinued and she was started on G-CSF and erythropoietin. Moderate skin and gut GVHD developed which was treated with both topical and low-dose oral steroids. Over the next few weeks she became transfusion independent and a follow-up bone marrow aspirate showed complete remission. She continued in complete remission for 4 months, at which time localized leukemic relapse was found in a soft tissue breast mass in spite of continued bone marrow remission. While the patient ultimately died of progressive disease, this case demonstrates that mismatched UCB in conjunction with G-CSF is capable of generating a GVL effect that can induce a complete remission.

Adolescent↗
PubMed2000

Placental blood for bone marrow replacement: the New York Blood Center's program and clinical results.

BACKGROUND AND OBJECTIVES: Placental/umbilical cord blood (PCB) has been used for allogeneic bone marrow replacement since 1988. The Placental Blood Program of the New York Blood Center has developed techniques for collecting, testing, freezing and searching units on behalf of unrelated patients in need of hematopoietic stem cell replacement since 1993 and provided analysis of the outcomes of these transplants identified variables associated with clinical outcomes. In this review, after considering practical and conceptual aspects of the technology, we update information on the clinical outcomes of these transplants. MATERIALS AND METHODS: All 861 patients transplanted through 1999 with PCB from our Program are included in this report. Two thirds were diagnosed with leukaemia or lymphoma, 25% with inherited conditions and 7% with acquired diseases. Outcome data were provided by the respective Transplant Center and analyses included both univariate and multivariate regression tests and actuarial (Kaplan-Meier) techniques. RESULTS: Engraftment was achieved by over 90% of recipients (Kaplan-Meier estimate). Multivariate analysis confirmed the influence of cell dose, HLA matching, disease diagnosis and transplant center location (US vs. foreign). Patient age and HLA match grade independently affected the frequency and severity of acute graft vs. host disease. Leukaemic relapse was associated with the stage of disease at transplantation and the prior existence of acute graft vs. host disease. The probability of transplant-related events was independently associated with disease diagnosis, cell dose, number of HLA mismatches and transplant center, while the cell dose failed to associate significantly with the relative risk of reaching this endpoint in the subset of patients who achieved engraftment. Overall, event-free survival rates at one year post-transplant were 49 and 30%, respectively for genetic disease and haematologic malignancies and 35% for patients with acquired diseases, respectively. CONCLUSIONS: These results confirm and extend earlier data, particularly establishing the significant association of transplant success with histocompatibility matching grades, and indicatng the urgency of improving the transplant match levels.

Adolescent↗
PubMed2000

Population-based estimates of surfactant protein B deficiency.

OBJECTIVE: Surfactant protein B deficiency is a lethal cause of respiratory distress in infancy that results most commonly from a homozygous frameshift mutation (121ins2). Using independent clinical ascertainment and molecular methods in different populations, we sought to determine allele frequency. STUDY DESIGN: Using clinical characteristics of the phenotype of affected infants, we screened the Missouri linked birth-death database (n = 1 052 544) to ascertain potentially affected infants. We used molecular amplification and restriction enzyme digestion of DNA samples from a metropolitan New York birth cohort (n = 6599) to estimate allele frequency. RESULTS: The point estimate and 95% confidence interval of the 121ins2 allele frequency in the Missouri cohort are 1/1000 individuals (.03-5.6/1000) and in the New York cohort are.15/1000 (. 08-.25/1000). These estimates are not statistically different. CONCLUSIONS: The close approximation of these independent estimates suggests accurate gene frequency (approximately one 121ins2 mutation per 1000-3000 individuals) despite its rare occurrence and that this mutation does not account for the majority of full-term infants with lethal respiratory distress.

Alleles↗
PubMed1999

The Placental/Umbilical Cord Blood Program of the New York Blood Center. A progress report.

The transplantation of placental/umbilical cord blood (P/CB) has been used successfully to reconstitute bone marrow function in both related and unrelated recipients. We report here the experience of the New York Blood Center P/CB Program. Since its inception in 1992, over 400 unrelated transplants were supported between July 1993 and September 1997. Overall, event-free survival for all diagnoses and ages approached 0.45. Success and rapidity of engraftment correlated most strongly with the degree of human leukocyte antigen (HLA) disparity and cell dose/kg body weight recipient. Acute graft-versus-host disease (GVHD) was common in all patients but, surprisingly, did not differ between those patients who received grafts having one or more antigen mismatches. Chronic GVHD was uncommon and only rarely contributed to death. These results demonstrate the feasibility of large-scale P/CB banking for the provision of cryopreserved stem cell preparations for unrelated transplants. The degree of the program's success argues strongly for additional P/CB banks in order to increase the likelihood of finding a suitable stem cell preparation for patients for whom related matched donors do not exist.

Anemia↗
PubMed1999

Prevalence of mild apparent mineralocorticoid excess in Mennonites.

UNLABELLED: We have studied an unusual patient with mild low-renin hypertension due to a homozygous mutation in the HSD11B2 gene (PNAS 95:10200-10205, 1998). The patient came from an inbred Mennonite family, and though the mutation identified her as an AME patient, she had a normal birth weight and did not demonstrate the typical features of AME, such as hypokalemic alkalosis, low birth weight, failure to thrive, poor growth, and in many cases nephrocalcinosis. Biochemically, typical patients with AME have abnormal cortisol metabolites and an exceedingly diminished ability to convert [11-3H]cortisol to cortisone. In this patient with mild AME, the conversion of cortisol to cortisone was 58% compared to 0 to 6% in typical AME patients, while the normal conversion is 90 to 95%. Molecular analysis of the HSD11B2 gene of this patient showed a homozygous mutation in codon 227 (P227L). We studied this Mennonite population for the prevalence of the P227L mutation. Our hypothesis was that this mild form of AME would be prevalent in the somewhat inbred Mennonite population to which the patient belongs. Our proposed study was 1) to determine if there are other cases of this mild form of AME, and 2) to establish the heterozygote frequency of the mutation in the Mennonites. RESULTS: We did not detect any additional cases of mild AME. We detected 15 carriers of the P227L mutation out of 445 Mennonites, resulting in a heterozygote frequency of 0.03. CONCLUSION: Since this is an inbred population, the chance of two heterozygotes marrying would be 0.001, which is 1 in 1000 people. This population is known to have large families and therefore the possibility of having an affected child is high. The population consists of 2000 members and we have discovered one affected patient. Thus, there might be one other patient in this population.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1998

Outcomes among 562 recipients of placental-blood transplants from unrelated donors.

BACKGROUND: A program for banking, characterizing, and distributing placental blood, also called umbilical-cord blood, for transplantation provided grafts for 562 patients between August 24, 1992, and January 30, 1998. We evaluated this experience. METHODS: Placental blood was stored under liquid nitrogen and selected for specific patients on the basis of HLA type and leukocyte content. Patients were prepared for the transplantation of allogeneic hematopoietic cells in the placental blood and received prophylaxis against graft-versus-host disease (GVHD) according to routine procedures at each center. RESULTS: Outcomes at 100 days after transplantation were known for all 562 patients, and outcomes at 1 year for 94 percent of eligible recipients. The cumulative rates of engraftment among the recipients, according to actuarial analysis, were 81 percent by day 42 for neutrophils (median time to engraftment, 28 days) and 85 percent by day 180 for platelets (median, day 90). The speed of myeloid engraftment was associated primarily with the leukocyte content of the graft, whereas transplantation-related events were associated with the patient's underlying disease and age, the number of leukocytes in the graft, the degree of HLA disparity, and the transplantation center. After engraftment, age, HLA disparity, and center were the primary predictors of outcome. Severe acute GVHD (grade III or IV) occurred in 23 percent of patients, and chronic GVHD occurred in 25 percent. The rate of relapse among recipients with leukemia was 9 percent within the first 100 days, 17 percent within 6 months, and 26 percent by 1 year. These rates were associated with the severity of GVHD, type of leukemia, and stage of the disease. CONCLUSIONS: Placental blood is a useful source of allogeneic hematopoietic stem cells for bone marrow reconstitution.

Actuarial Analysis↗