Tobacco-free youth. Expanding focus group networks.
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Adolescent↗
Biomedical subjects
J Sanders
Publications and source records attributed to J Sanders.
Cyclophosphamide plus ATG conditioning is insufficient for sustained hematopoietic reconstitution in patients with severe aplastic anemia transplanted with marrow from HLA-A, B, DRB matched unrelated donors.
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Adolescent↗
Structural requirements for the utilization of ascorbate analogues in the prolyl 4-hydroxylase reaction.
The ability of structural analogues of ascorbate to serve as substitutes for this reducing agent in the prolyl 4-hydroxylase reaction was studied. In experiments using the purified enzyme, variations of the compounds' side chain were compatible with co-substrate activity. The presence of very large hydrophobic substituents or a positively charged group caused an increase in the observed Km values. A negative charge and smaller modifications did not change the affinity to the enzyme when compared with L-ascorbate. 6-Bromo-6-deoxy-L-ascorbate had a lower Km than the physiological reductant. Substitution at the -OH group in ring position 3 prevented binding to the enzyme. The same pattern of activity was observed when the full and uncoupled prolyl 4-hydroxylase reactions were studied. The Vmax. values with all compounds were similar. The reaction of microsomal prolyl 4-hydroxylase was supported by D-isoascorbate, O6-tosyl-L-ascorbate and 5-deoxy-L-ascorbate, giving the same dose-response behaviour as L-ascorbate itself. Again, 6-bromo-6-deoxy-L-ascorbate gave a lower Km and a similar Vmax. value. L-Ascorbic acid 6-carboxylate produced substrate inhibition at concentrations above 0.3 mM. The Km and Vmax. values calculated from concentrations up to 0.2 mM were similar to those of L-ascorbate. The enzyme activity observed with 6-amino-6-deoxy-L-ascorbate was very low in the microsomal hydroxylation system. The calculated Vmax. value was lower than that of L-ascorbate, suggesting a restriction of the access of this compound to the enzyme.
Amino Acid Sequence↗
Plasma melatonin concentration in neonatal northern elephant seals, Mirounga angustirostris.
The development of pineal function in northern elephant seals was examined in an attempt to understand the physiological basis for previously observed high daytime levels of melatonin in neonatal southern elephant seals. Pineal glands from four northern elephant seal pups, estimated age less than 1 week, weighted 3.0 +/- 0.80 g, which was significantly less than that previously found in southern elephant seals (4.6 +/- 0.35 g). Midday concentrations of plasma melatonin in pups averaged more than 3000 pmol/l in the first 5 days post-partum, but declined rapidly to less than 400 pmol/l after day 9. Daytime melatonin levels in northern elephant seals tended to be lower than in southern elephant seals, although they were very high compared with other species. A circadian cycle of plasma melatonin concentration was observed in newborn northern elephant seals, with levels of 3000-5000 pmol/l during the day, rising to more than 10,000 pmol/l late in the dark phase. Soon after weaning at 4 weeks of age, daytime and night-time levels were in the range 60-100 pmol/l and 100-400 pmol/l, respectively. When approximately 10 weeks old, most samples were in the range 100-400 pmol/l with no discernible difference between day and night levels. The results do not support the hypothesis that the pineal gland is involved in thermogenesis in new-born southern elephant seals. Instead, the very active pineal gland may contribute to energy conservation, by lowering body temperature, particularly at night. As physical insulation is acquired by the deposition of blubber, the mechanism is not required and melatonin falls to adult levels.
Aging↗
Circulation profile of technetium-99m labeled liposome encapsulated hemoglobin in a 10% or 50% rat hypovolemic shock model.
The circulation kinetics and organ biodistribution of liposome encapsulated hemoglobin (LEH) was determined non-invasively in hypovolemic rats using a technetium-99m (Tc-99m) liposome labeling procedure. Rats with an indwelling catheter had either 10% or 50% of their blood volume removed and replaced with an equal volume of LEH labeled with Tc-99m (Tc-99m LEH). Mean arterial pressures and heart rates were monitored throughout the experiment. Gamma camera images were acquired during the first 90 minutes following infusion of the Tc-99m LEH and at 20 hours post-infusion. Blood capillaries were drawn at various times to monitor Tc-99m activity and the amount of LEH remaining in circulation. There were significant differences in the kinetics and biodistribution for the two groups. In the 10% group, the LEH was removed quickly from circulation with only 0.9% remaining at 20 hours, while the 50% group had 51.2% at 20 hours. The liver and spleen were the major organs responsible for LEH clearance. The 20 hour biodistribution by tissue sampling showed that the 10% group had 37.6% in the liver and 34.3% in the spleen, while the 50% group had only 18.4% in the liver and 14.6% in the spleen.
Animals↗
Effect of graft-versus-host disease prophylaxis on relapse in patients transplanted for acute myeloid leukemia.
Between November 1978 and September 1988, 184 patients with acute myeloid leukemia in first remission received marrow transplants from HLA-identical siblings after conditioning with 120 mg/kg of cyclophosphamide and 12.0 Gy fractionated total body irradiation. Patients received either cyclosporine (CYA, n = 59), methotrexate (MTX, n = 82), or MTX + CYA (n = 43 as graft-versus-host disease (GVHD) prophylaxis. The probabilities of grades II-IV acute GVHD after CYA, MTX or MTX+CYA were 0.43, 0.48 and 0.28, respectively (p = 0.06). The probability of non-relapse mortality was 0.53, 0.50 and 0.42 at 4 years in patients treated with CYA, MTX, or MTX + CYA, respectively. The probability of relapse was 0.24 in patients receiving CYA, 0.24 in patients receiving MTX and 0.44 in patients receiving MTX + CYA (p = 0.02). The probability of survival at 4 years was 0.54 with CYA, 0.51 with MTX and 0.45 with MTX + CYA. A multivariate analysis of risk factors for relapse examined age, WBC at diagnosis, blast count at diagnosis, percentage of marrow blasts, FAB subtype, the number of remission induction courses to achieve a remission, maintenance therapy, consolidation therapy, marrow cell dose, donor-recipient sex, GVHD prophylaxis regimen and isolation and decontamination in laminar airflow rooms. GVHD prophylaxis with MTX + CYA was independently significantly associated with an increased risk of relapse (relative risk 2.25, p = 0.01). Acute GVHD was associated with increased non-relapse mortality (RR = 3.58, p < 0.0001). The administration of MTX + CYA did not adversely affect survival because patients receiving this regimen experienced less mortality from causes other than relapse when compared with patients receiving either CYA or MTX alone.
Adolescent↗
The human leucine zipper-containing guanine-nucleotide exchange protein elongation factor-1 delta.
Copy-DNA clones containing the complete coding region of the human elongation factor-1 delta (EF-1 delta) mRNA have been isolated and characterized. We present the deduced amino acid sequence and observe in it a leucine zipper motif seen recently in EF-1 delta from Artemia and Xenopus laevis. The human EF-1 delta sequence shows a strong conservation in its C-terminal domain. The homology between the N-terminal domains of EF-1 delta proteins is low and almost exclusively limited to the leucine zipper motif.
Amino Acid Sequence↗
Recombinant granulocyte-macrophage colony stimulating factor followed by immunosuppressive therapy for aplastic anaemia.
Seventeen patients with aplastic anaemia were treated with recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) for 14 d. Nonresponding patients were then treated with anti-human thymocyte globulin (ATG), methylprednisolone and oxymetholone. Side-effects of rhGM-CSF included fever, nausea and vomiting, diarrhoea, bone pain, headache and chills. Two patients had sustained trilineage haemopoietic recovery after receiving only rhGM-CSF. Of 11 patients who received immunosuppressive therapy, there was one complete response, two partial responses, one minimal response, and seven nonresponses. Actuarial survival at 2 years is 64%. Early administration of rhGM-CSF had no apparent effect on subsequent response to immunosuppressive therapy.
Adolescent↗
Intensively timed induction therapy followed by autologous or allogeneic bone marrow transplantation for children with acute myeloid leukemia or myelodysplastic syndrome: a Childrens Cancer Group pilot study.
PURPOSE: Childrens Cancer Group (CCG) protocol 2861 was designed to test the feasibility of aggressively timed induction therapy followed by autologous or allogeneic bone marrow transplantation (BMT) as the sole postremission therapy for newly diagnosed children with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). PATIENTS AND METHODS: Between April 1988 and October 1989, 142 patients were eligible for study. All patients entered received a timing-intensive five-drug induction of dexamethasone, cytarabine (Ara-C), thioguanine, etoposide, and daunorubicin (DCTER) over 4 days with a second cycle administered after 6 days of rest, irrespective of hematologic status at that time. Most patients subsequently received a second two-cycle induction course. Those who achieved remission were eligible for bone marrow ablative therapy with busulfan and cyclophosphamide, followed by 4-hydroperoxy-cyclophosphamide (4-HC)-purged autologous or allogeneic BMT rescue. RESULTS: One hundred eight (76%) patients achieved remission: 19 (13%) died of complications of the leukemia and/or chemotherapy, and 15 (11%) failed to achieve remission. Seventy-four patients subsequently underwent BMT with either autologous (n = 58) or allogeneic (n = 16) rescue. For patients who received autologous rescue with 4-HC-purged grafts, the actuarial disease-free survival (DFS) rate at 3 years from the day of transplant is 51%, compared with 55% for patients who received allogeneic grafts (P = .92). At 3 years, the overall actuarial survival rate for all 142 patients entered on this study is 45%, with an event-free survival (EFS) rate of 37%. Adverse prognostic factors for outcome included an elevated WBC count or the presence of CNS leukemia at the time of AML diagnosis. CONCLUSION: Results suggest that aggressively timed induction therapy followed by marrow ablation and BMT rescue with either autologous or allogeneic grafts for children with newly diagnosed AML or MDS is both feasible and effective.
Actuarial Analysis↗
Developing Georgia's telemedicine network.
Passage of Georgia's Distance Learning and Telemedicine Act of 1992 resulted in a windfall of $50 million from telephone company over-earnings. Rather than refund the money to consumers, legislators created a fund to finance telecommunications projects in medicine and education. When Governor Zell Miller signed the Act into law more than a year ago, he said, "[It] will immediately catapult Georgia to the forefront of this nation in the use of advanced telecommunications to improve the quality of life of its people." The law also set the state's cable television and telephone companies at odds. Nancy Horne, executive director of the Cable Television Association of Georgia, said that her industry's broadband fiber and coaxial infrastructure is in place to provide the state with telemedicine capabilities, and that transmission of full motion video or high resolution diagnostic images could take hours over standard telephone lines. Representatives of telephone companies argue that new high-speed cell relay switching technology provides instantaneous communications. An appointed Board of Governors holds tightly to the strings that secure a purse containing the $50 million. No grants have yet been awarded. In the middle of the debate stands Georgia's Department of Administrative Services, which moderates the competition between the two industries. And, the Medical College of Georgia created a demonstration project based on telephone technology. Representatives of both institutions gave Healthcare Informatics their views on developments of telemedicine in Georgia.
Computer Communication Networks↗
From science to evidence: the testimony on causation in the Bendectin cases.
Critics of American tort law often question the ability of lay jurors to make factual determinations in trials involving complex scientific evidence. In this article, Professor Sanders attempts to refocus tort reform debate by studying how trial procedures themselves contribute to jurors' inability to properly assess scientific evidence. Professor Sanders' analysis centers on trials involving Bendectin, a drug which plaintiffs have claimed caused birth defects in the children of mothers who took it during pregnancy. After noting that the weight of scientific and federal judicial opinion concludes that plaintiffs cannot establish a causal link between Bendectin use and birth defects by a preponderance of the evidence, Professor Sanders analyzes the transcripts of six Bendectin trials to determine why jury verdicts do not comport with the weight of scientific and judicial opinion. Based on his conclusion that trials are incapable of adequately conveying the weight of scientific opinion to a lay jury, he evaluates the ability of various trial reform proposals to ameliorate this problem. Finally he recommends adopting proposals that would facilitate jurors' understanding of scientific evidence and lead to verdicts consistent with the weight of scientific opinion.
Abnormalities, Drug-Induced↗
Autologous bone marrow transplantation for acute lymphoblastic leukemia.
Between December 1979 and February 1991, 89 patients with ALL received autologous BMT. Median patient age was 18.4 years. Ten patients were in first remission, 52 were in second or greater remission and 27 were in relapse at the time of transplant. Conditioning regimens utilized chemotherapy alone (5 patients) or in combination with 10-15.75 Gy total body irradiation (84 patients). Disease-free survival at 1 year is 50% for patients transplanted in first remission, 27% for those in > or = second remission and 8% for patients in relapse. Pre- and post-transplant variables were evaluated in univariate and multivariate analyses for their effect on survival and relapse. Factors significantly associated with improved survival were being transplanted in first remission and achieving a self-sustained platelet count > or = 20 x 10(9)/l in a shorter period of time. A decreased relapse rate after transplant was associated with a lower white blood count at diagnosis, being transplanted in first remission and not being transplanted in relapse.
Adolescent↗
Consequences of cryopreserving first remission autologous marrow for use after relapse in patients with acute myeloid leukemia.
Ninety-eight patients with AML had marrow harvested and cryopreserved at a median of 6 months (range 1-36 months) after achieving first CR with the intent of performing an ABMT at the first sign of relapse. Thirty-three of the 98 patients have not relapsed and 32 survive at a median of 64 months (range 10-105 months) after marrow storage. Sixty-five of the 98 patients relapsed at a median of 7 months (range 1-53 months) after marrow storage. The survival at 2 and 4 years for the 65 patients who relapsed was 22% and 8% respectively. Sixteen of 24 patients treated initially with chemotherapy were ultimately transplanted and two are surviving 21 and 41 months following ABMT and allogeneic marrow transplant respectively. There were no survivors among the eight patients treated with chemotherapy who were not transplanted. Thirty-eight of the 65 patients who relapsed proceeded directly to ABMT without attempts at remission induction, and eight survive disease-free 15-114 months following ABMT. One of the first 17 patients treated with cyclophosphamide and total body irradiation survives without relapse. The probabilities of relapse-free survival, non-relapse mortality, and relapse for the 17 most recent patients prepared with busulfan-containing regimens were 41%, 39% and 32% respectively. Surviving patients had longer first remissions (p = 0.08) and lower peripheral blood blast counts at the time of transplant (p = 0.02) when compared with patients who died. These data suggest that ABMT in untreated first relapse is a reasonable approach for the treatment of patients with AML who relapse.
Adolescent↗
Elongation factor-1 messenger-RNA levels in cultured cells are high compared to tissue and are not drastically affected further by oncogenic transformation.
Copy-DNA clones covering the complete coding sequence of human Elongation Factor-1 gamma mRNA have been isolated and characterized. The expression of Elongation Factor-1 in a variety of cell lines and a number of tissues shows a large increase in Elongation Factor-1 mRNA going from tissue to cultured cells (20-fold). Messenger-RNA levels for Elongation Factor-1 alpha, -1 beta and -1 gamma increase in parallel suggesting coordinate regulation of the expression of these genes. Oncogenic transformation in vitro does not strongly affect Elongation Factor-1 mRNA levels.
Amino Acid Sequence↗
Immunosuppressive therapy of aplastic anemia: results of a prospective, randomized trial of antithymocyte globulin (ATG), methylprednisolone, and oxymetholone to ATG, very high-dose methylprednisolone, and oxymetholone.
Sixty-eight patients with moderate (n = 15) or severe (n = 53) aplastic anemia were entered into a prospective, randomized, two-arm treatment study comparing antihuman thymocyte globulin (ATG), lower-dose methylprednisolone (LDM) and oxymetholone to ATG, higher-dose methylprednisolone (HDM), and oxymetholone. There were no differences between the two groups when comparing age, sex, etiology of aplasia, disease duration, severity of aplasia, or pretherapy granulocyte counts. Side effects of LDM and HDM were similar. Of the 64 patients evaluable for response to therapy, 12 of 33 (36%) who received LDM had complete, partial, or minimal responses compared with 15 of 31 patients (48%) who received HDM (P = .33). Actuarial survival at 4 years is 43% for patients in the LDM group and 47% for patients in the HDM group (P = .99). Causes of death included hemorrhage, infection, evolution to acute leukemia, and complications of subsequent bone marrow transplantation. Long-term complications included paroxysmal nocturnal hemoglobinuria (n = 3), evolution to myelodysplasia or acute leukemia (n = 6), and recurrent aplasia (n = 6). We were unable to show a significant difference in toxicity, response rate, or survival for patients treated with ATG, oxymetholone, and LDM compared with patients who received ATG, oxymetholone, and HDM.
Adult↗
Phase II trial of recombinant human granulocyte-macrophage colony-stimulating factor in patients undergoing allogeneic bone marrow transplantation from unrelated donors.
The safety and possible efficacy of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) were evaluated in 40 consecutive patients who received transplants from unrelated donors. rhGM-CSF was administered by 2-hour daily intravenous infusion from day 0 to day 20 or day 27 after the marrow infusion. These patients were compared with 78 historical patients who received transplants from unrelated donors who did not receive rhGM-CSF. The rhGM-CSF-treated patients were older (P = .037) and were treated less frequently in laminar air flow rooms (P = .005) than were control patients. However, the rhGM-CSF-treated group had a higher proportion of "good risk" patients with chronic myelogenous leukemia in chronic phase (P = .006) than did the comparison group (P = .017), rendering comparisons of transplant-related complications not meaningful. rhGM-CSF was well tolerated and did not adversely increase the incidence of graft rejection or increase the incidence and severity of acute graft-versus-host disease. The median day the absolute neutrophil count reached 500/mm3 in patients who received rhGM-CSF was day 21, which was not different from that of historical patients. Nevertheless, the numbers of febrile days and septicemic episodes within the first 28 days in patients who received rhGM-CSF were less than in historical patients. The probability of nonrelapse mortality at 1 year in patients who received rhGM-CSF was 22%. In view of the retrospective nature of the control group, we cannot conclusively determine whether rhGM-CSF administration was beneficial. A prospective, randomized controlled study of rhGM-CSF is required to confirm these suggestive data.
Adult↗
Circle reopening in the Tetrahymena ribozyme resembles site-specific hydrolysis at the 3' splice site.
The Tetrahymena intron, after splicing from its flanking exons, can mediate its own circularization. This is followed by site-specific hydrolysis of the phosphodiester bond formed during the circularization reaction. The structural components involved in recognition of this bond for hydrolysis have not been established. We have made base substitutions to the P9.0 pairing and at the 3'-terminal guanosine residue (G414) of the intron to investigate their effects on circle formation and reopening. We have found that disruption of either P9.0 pairing or binding of the terminal nucleotide result in the formation of a large circle, C-413:5E23 from precursor RNA molecules that have undergone hydrolysis at the 3' splice site. This circle is formed at the phosphodiester bond of the 5'-terminal guanosine residue of the upstream exon via nucleophilic attack by the 3'-terminal nucleotide of the intron. The large circle is novel since it can reopen eight bases downstream from the original circularization junction at a site resembling the normal 3' splice site, restoring a guanosine to the 3' terminus and re-establishing P9.0 pairing. The new 3' terminus of the intron is capable of recircularization at any of the three normal wild-type sites. We conclude that both P9.0 and the 3'-terminal guanosine residue are required for the selection of the phosphodiester bond hydrolysed during circle reopening.
Animals↗
Allogeneic marrow transplantation during untreated first relapse of acute myeloid leukemia.
PURPOSE: The purpose of this report was to review the Seattle experience in bone marrow transplantation (BMT) for acute myeloid leukemia (AML) during untreated first relapse. PATIENTS AND METHODS: Through 1990, 126 patients were transplanted during untreated first relapse of AML. Several preparative regimens were used, two of which involved more than 20 patients. Regimen 1 (29 patients) consisted of cyclophosphamide (CY) 120 mg/kg and 15.75 Gy of fractionated total-body irradiation (TBI) with methotrexate (MTX) given intermittently during a 102-day period to prevent graft-versus-host disease (GVHD). Regimen 2 (22 patients) consisted of the same CY and TBI treatment and a combination of MTX and cyclosporine (CSP) for GVHD prophylaxis. The remaining 75 patients were treated with 17 other transplant regimens. Outcome was compared for patients who were treated with regimen 1, regimen 2, and any other regimen. RESULTS: The 5-year probabilities of relapse-free survival (RFS), relapse, and nonrelapse mortality for 126 patients were .23, .57, and .44, respectively. With regimen 1, relapse (.26) was significantly less than for regimen 2 (.70; P = .004) or any other regimen (.76; P = .004). Regimen 1 patients developed more acute GVHD (.67) than regimen 2 patients (.26; P = .02) or patients on other regimens (.41; P = .02), and had increased nonrelapse mortality. Nevertheless, regimen 1 patients had a significantly higher 3-year RFS (.38) than those treated with regimen 2 (.18; P = .04) or any other regimen (.20; P = .05). CONCLUSIONS: For patients who received 120 mg/kg CY and 15.75 Gy TBI, relapse incidence was less and survival was better after GVHD prophylaxis with MTX alone than after a combination of MTX and CSP, despite a significantly higher incidence of acute GVHD. The results of treatment with regimen 1 justify future studies of the optimal timing of allogeneic BMT in the treatment of patients with AML.
Acute Disease↗