Deletions extending from a single Ty1 element in Saccharomyces cerevisiae.

Chromosomal rearrangements associated with one Ty1 element in the iso-1-cytochrome c (CYC1) region of Saccharomyces cerevisiae yeast cells were examined. Most of the rearrangements were deletions of the three linked genes, CYC1, OSM1, and RAD7, and resulted from recombination involving the single Ty1 element and a solo delta in the same orientation. These deletions differed by the number of Ty1 elements (zero, one, or two) remaining after deletion and by restriction site heterogeneities associated with these elements. A single Ty1 element remained at the deletion junction point much more frequently than no Ty1. Apparently the Ty1-associated delta element nearer to the solo delta was involved more often in recombination than the more distal Ty1-associated delta element. The restriction site data implicate gene conversion and suggest that site-specific recombination within the deltas, if occurring, is not the only mechanism of delta-delta recombination. Three other rearrangements bore deletions which began at the end of the Ty1 element and extended into regions not bearing Ty1 or delta sequences. Two of these deletions eliminated 7 kilobases of DNA, although they differed by an associated reciprocal translocation. The third involved a deletion of 14.7 kilobases of DNA associated with an overlapping inversion.

Radiation-free preparation for allogeneic bone marrow transplantation in adults with acute lymphoblastic leukemia.

PURPOSE: The study was undertaken to investigate the effectiveness of allogeneic bone marrow transplantation from HLA-identical siblings after preparation with busulfan and cyclophosphamide in adults with acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Thirty-nine patients aged 15 to 42 years underwent transplantation at three different centers from November 1984 through November 1990. All patients received 16 mg/kg busulfan and 120 mg/kg cyclophosphamide as preparative therapy. Cyclosporine plus methotrexate or cyclosporine plus corticosteroids with or without methotrexate were given for prevention of graft-versus-host disease (GVHD). RESULTS: Twelve patients died of treatment-related complications, 12 patients relapsed, and 15 patients are leukemia-free survivors. For 27 patients in group 1 (first remission, second remission, first relapse), the estimated leukemia-free survival (LFS) rate is 42.3% (95% confidence interval [CI], 22.9% to 71.7%) at 3 years. For 12 patients with more advanced disease (group 2), the 1-year LFS rate is 13.5% (95% CI, 0% to 37.1%). Chronic GVHD occurred at an estimated incidence of 63.3% and developed significantly more frequently among patients who received corticosteroids for prevention of acute GVHD. Chronic GVHD was associated with a significantly lower incidence of relapse and with improved LFS rates. CONCLUSION: LFS rate in this study is comparable to that obtained with radiation-containing regimens; however, the effectiveness of this preparative regimen in ALL requires further study.

Glutaredoxin 2a overexpression in macrophages promotes mitochondrial dysfunction but has little or no effect on atherogenesis in LDL-receptor null mice.

AIMS: Reactive oxygen species (ROS)-mediated formation of mixed disulfides between critical cysteine residues in proteins and glutathione, a process referred to as protein S-glutathionylation, can lead to loss of enzymatic activity and protein degradation. Since mitochondria are a major source of ROS and a number of their proteins are susceptible to protein-S-glutathionylation, we examined if overexpression of mitochondrial thioltranferase glutaredoxin 2a (Grx2a) in macrophages of dyslipidemic atherosclerosis-prone mice would prevent mitochondrial dysfunction and protect against atherosclerotic lesion formation. METHODS AND RESULTS: We generated transgenic Grx2aMac(LDLR-/-) mice, which overexpress Grx2a as an EGFP fusion protein under the control of the macrophage-specific CD68 promoter. Transgenic mice and wild type siblings were fed a high fat diet for 14 weeks at which time we assessed mitochondrial bioenergetic function in peritoneal macrophages and atherosclerotic lesion formation. Flow cytometry and Western blot analysis demonstrated transgene expression in blood monocytes and peritoneal macrophages isolated from Grx2aMac(LDLR-/-) mice, and fluorescence confocal microscopy studies confirmed that Grx2a expression was restricted to the mitochondria of monocytic cells. Live-cell bioenergetic measurements revealed impaired mitochondrial ATP turnover in macrophages isolated from Grx2aMac(LDLR-/-) mice compared to macrophages isolated from non-transgenic mice. However, despite impaired mitochondrial function in macrophages of Grx2aMac(LDLR-/-) mice, we observed no significant difference in the severity of atherosclerosis between wildtype and Grx2aMac(LDLR-/-) mice. CONCLUSION: Our findings suggest that increasing Grx2a activity in macrophage mitochondria disrupts mitochondrial respiration and ATP production, but without affecting the proatherogenic potential of macrophages. Our data suggest that macrophages are resistant against moderate mitochondrial dysfunction and rely on alternative pathways for ATP synthesis to support the energetic requirements.

Sequence of a cDNA encoding a mouse cyclin B protein.

We report here the nucleotide sequence of a cDNA encoding a mouse (Mus musculus) cyclin B protein. The deduced protein shows 84%, 66% and 49% similarity with human cyclin, Xenopus cyclin B1 and B2, respectively.

Treatment of chronic myelogenous leukemia with allogeneic bone marrow transplantation after preparation with busulfan and cyclophosphamide (BuCy2): an update.

Allogeneic bone marrow transplantation (BMT) has been shown to result in long-term disease-free survival in patients with leukemia. However, the utility of this treatment approach is limited by treatment-related morbidity and mortality. We present an update of a study in which a BMT preparative regimen consisting of a 4-day course of busulfan and a 2-day course of cyclophosphamide (BuCy2) was used in patients with chronic myelogenous leukemia. Patient survival depended on disease stage, with a 58% survival rate for patients in first chronic phase, 41% for those in accelerated phase, and 25% for those in the blast transformation stage. There was a significant difference in patient survival between those who received transplants within 1 year of diagnosis and those who received transplants more than 1 year after diagnosis (70% v 40%). This difference appeared to be due to the extent of previous exposure to busulfan. The overall mortality rate in this study was 46%. We conclude that the BuCy2 preparative regimen is similar in effectiveness to regimens that include total body irradiation and results in comparable levels of transplant-related mortality. Our results strongly indicate that patients with chronic myelogenous leukemia who receive BMT within the first year after diagnosis have a significantly better clinical outcome than those who receive BMT later in the course of the disease.

Early placental ontogeny in the mouse.

Fundamental to placental morphogenesis is union between the allantois and the chorion, two tissues initially separated in the conceptus. Results of previous studies in the mouse have suggested that chorio-allantoic union is driven by the developmental maturity of the allantois and involves molecular interactions between Vascular Cell Adhesion Molecule (VCAM-1) in the allantois and alpha4-integrin in the chorion. Little more is known about the cellular and/or molecular control of this important morphogenetic event in any species.Gross, histological, microsurgical and immunohistochemical analyses in the mouse conceptus revealed that placental ontogeny took place in three major steps. The first, chorio-allantoic contact, was not enduring and was mediated by the allantois' mesothelial surface and the mesodermal component of the chorion. Modest amounts of VCAM-1 were found in distal allantoic mesothelium, whilst levels of alpha4-integrin were high throughout chorionic mesoderm. The second step, chorio-allantoic fusion, was more enduring. During this time, the distal allantoic region contained maximal levels of VCAM-1, and all allantoises had expanded far enough to reach the posterior chorion from where they spread toward a central chorionic depression. The last step, breakdown of chorio-allantoic fusing surfaces, was dependent upon chorio-allantoic fusion and resulted in the intimate juxtaposition of allantoic endothelium and chorionic ectoderm, possibly as a result of VCAM-1-mediated interactions. The umbilical connection was thereafter fixed at its perimeter to the chorionic surface by large amounts of VCAM-1 in disto-lateral allantoic mesothelium and alpha4-integrin in the remaining peripheral mesodermal component of the chorion.Thus, chorio-allantoic union is highly regulated, taking place in multiple steps. It is dependent upon the developmental maturity of distal allantoic mesothelium and involves the mesodermal component of the chorion. Breakdown of fusing surfaces enables penetration of the allantoic vasculature into the chorion. These findings provide a secure developmental foundation in which to elucidate the genetic control of early placentation.

Inhaled corticosteroids for asthma therapy: patient compliance, devices, and inhalation technique.

BACKGROUND: Patient compliance, inhalation devices, and inhalation techniques influence the effectiveness of inhaled medications. METHODS: This article presents the results of a systematic literature review of studies measuring compliance with inhaled corticosteroids, measuring inhalation technique with different inhalation devices, and estimating the proportion of inhaled drug that is deposited in the lung. RESULTS: Overall, patients took the recommended doses of inhaled medication on 20 to 73% of days. Frequency of efficient inhalation technique ranged from 46 to 59% of patients. Education programs have been shown to improve compliance and inhalation techniques. The lung deposition achieved with different inhalers depends on particle size as well as inhaler technique. CONCLUSION: This review demonstrates that multiple factors may come between a prescription of an inhaled corticosteroid and the arrival of that medicine at its target organ, the lung.

Omission of day 11 methotrexate does not appear to influence the incidence of moderate to severe acute graft-versus-host disease, chronic graft-versus-host disease, relapse rate or survival after HLA-identical sibling bone marrow transplantation.

Sixty-five patients with haematological malignancy received high-dose chemotherapy or chemoradiotherapy followed by a T replete, HLA-identical sibling bone marrow transplant. All were scheduled to receive a standard cyclosporine/methotrexate immune suppressive regimen to minimise the risk of graft-versus-host disease post-transplant. Forty-six patients received all four scheduled doses of methotrexate, while in nineteen the day 11 dose was omitted due to marked oropharyngeal mucositis or febrile neutropenia. There was a slight increase in the incidence of acute graft-versus-host disease (GVHD) grades I-IV in those not receiving compared to those receiving day 11 methotrexate (84 vs 71% (P = 0.04)). However, there was no difference in the incidence of acute GVHD grades II-IV (14 vs 22%), in the incidence of chronic GVHD (38 vs 47%), in transplant-related mortality (21 vs 24%), in relapse rate (42 vs 51%), in 4-year survival (38 vs 48%), or in disease-free survival (38 vs 42%). These findings suggest that the day 11 methotrexate dose could be omitted without a major deleterious effect on the outcome of HLA-identical sibling marrow transplantation.

Bone marrow transplantation in Australia during 1992. Australian Bone Marrow Transplant Recipient Data Registry.

Australia has a population of 17.5 million people distributed in six states and two territories. The first allogeneic transplants were performed in the early 1970s. There are now 19 hospitals registered with the Australian Bone Marrow Transplant Recipient Data Registry. In 1992 a total of 478 transplant procedures were carried out, of which 228 were allografts and 250 were autografts. The principal indications for allografting were acute leukaemia and chronic myeloid leukaemia; the principal indications for autografting were non-Hodgkin's lymphoma, acute myeloid leukaemia and myeloma. In general the patterns of indications and donor use do not differ from those seen in most European countries and North America.

Lenograstim administration to HLA-identical donor-recipient pairs to accelerate marrow recovery post-transplant.

In an attempt to accelerate marrow recovery after HLA-identical sibling bone marrow transplantation, the donors of 12 patients with haematological malignancy were given recombinant human granulocyte colony-stimulating factor (rHuG-CSF; lenograstim; Granocyte) 5 micrograms/kg/day for seven doses prior to marrow harvest. All 12 recipients also received lenograstim 5 micrograms/kg/day from the day of transplant until their neutrophil count was 1.0 x 10(9)/1. In addition to lenograstim post-transplant and lenograstim-stimulated donor bone marrow the first six recipients also received donor peripheral blood stem cells that had been enriched for CD34+ stem/progenitor cells and T cell depleted on an immune absorption column (cohort 1). The second six patients (cohort 2) received lenograstim post-transplant and lenograstim-stimulated donor marrow only. All 12 patients showed a marked elevation of their circulating white blood cell count (predominantly neutrophils) on day 1 post-transplant. Compared to carefully matched historical control patients the rate of neutrophil engraftment was significantly accelerated in both patient cohorts and platelet engraftment was accelerated in cohort 2.