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Biomedical subjects

K M Sullivan

Publications and source records attributed to K M Sullivan.

At least 217 records · Page 12Linked to original sources
PubMed1989

Minimal risk of chronic renal dysfunction in marrow transplant recipients treated with cyclosporine for 6 months.

To determine whether 6 months of cyclosporine therapy is associated with chronic renal dysfunction, we evaluated serum creatinine concentrations 1 year post-transplant in 82 marrow transplant recipients randomized to receive either cyclosporine (n = 40) or methotrexate (n = 42) as graft-versus-host disease (GVHD) prophylaxis. Nine patients in the methotrexate group were later given cyclosporine as treatment for acute or chronic GVHD (methotrexate----cyclosporine). Cyclosporine prophylaxis was started on the day before marrow infusion, given at full doses until day 50, then gradually tapered and discontinued by day 180. Methotrexate prophylaxis was started on day 1 and given intermittently until day 102. Patients in the cyclosporine and methotrexate----cyclosporine groups had significantly higher mean serum creatinine values during the first 100 days post-transplant than methotrexate-treated patients, but by 1 year mean serum creatinine values were not significantly different between the three groups. Serum creatinine values at 1 year were also not significantly different from baseline values in each of the groups. None of the patients who had their cyclosporine discontinued by day 180 developed chronic renal dysfunction, defined as a doubling of the baseline serum creatinine at 1 year. We conclude that chronic renal dysfunction occurs rarely in marrow transplant recipients treated with 6 months of cyclosporine and when it does occur, it appears to have minimal clinical significance.

Bone Marrow Transplantation↗
PubMed1989

Graft-v-host disease is associated with autoimmune-like thrombocytopenia.

Persistent thrombocytopenia after allogeneic marrow transplantation is associated with poor patient survival. To identify the mechanisms of the thrombocytopenia, we studied platelet and fibrinogen kinetics and antiplatelet antibodies in 20 patients between 60 and 649 days (median 90) after transplantation. Seventeen patients had isolated thrombocytopenia (less than 100 X 10(9) platelets/L): the marrow cellularity was normal in five patients and slightly reduced in 12, and there was no discrepancy between thrombopoiesis and myeloerythropoiesis. Three patients had pancytopenia following marrow graft rejection (two) and relapse of leukemia (one). Only three patients had evidence of increased platelet production, indicating that in most cases there is a poor marrow response to thrombocytopenia early after marrow grafting. There was no correlation between platelet count and splenic pooling, suggesting that hypersplenism was an unlikely mechanism of the thrombocytopenia. Although there was a direct relationship between platelet count and platelet survival, the reduction in platelet survival was greater than what could be explained by the fixed platelet removal found in thrombocytopenic patients; this suggests increased platelet destruction. Seven patients had intercurrent infections that reduced both platelet and fibrinogen survivals. In addition, platelet antibodies bound to autologous or marrow donor platelets were present in five of the 12 patients studied. Patients with antiplatelet antibodies had lower platelet counts (30 +/- 10 X 10(9)/L v. 49.1 +/- 28.7 X 10(9)/L, P less than 0.05) and platelet survivals (1.32 +/- 0.92 days v. 3.58 +/- 2.02 days, P less than 0.05) than patients without antiplatelet antibodies. Furthermore, platelet-bound autoantibodies were present in five of six patients with grade II-IV acute or chronic graft-versus-host disease (GVHD), but were not present in six patients free of GVHD (P less than 0.01). We conclude that persistent thrombocytopenia after marrow transplantation is most often secondary to increased platelet destruction mediated by multiple mechanisms and that platelet autoantibodies are found in patients with acute or chronic GVHD.

Adolescent↗
PubMed1988

Long range structural communication between sequences in supercoiled DNA. Sequence dependence of contextual influence on cruciform extrusion mechanism.

Sequence context may profoundly alter the character of structural transitions in supercoiled DNA (Sullivan, K. M., and Lilley, D. M. J. (1986) Cell 47, 817-827). The A + T-rich sequences of ColE1, which flank the inverted repeat, are responsible for cruciform extrusion following a mechanistic pathway which proceeds via a relatively large denatured region. This C-type mechanism results in kinetic properties which are very different from those of the S-type pathway, the normal mechanism of cruciform extrusion in the absence of the ColE1 flanking sequences. We have analyzed the sequence requirements for the induction of the C-type pathway. The 100-base pair left side sequence of ColE1 (colL) was subjected to systematic deletion using Bal31 exonucleolysis, showing that removal of 30 base pairs from its right end abolished extrusion by the C-type process. A cloned oligonucleotide of the same 30-base pair sequence was sufficient to confer C-type cruciform extrusion on an adjacent inverted repeat. An A + T-rich sequence from Drosophila was found to act like the ColE1 sequences. We have studied the effects of introducing sequences between the A + T-rich colL, and the inverted repeat on which it acts. A range of such fragments was found, from those which augment the effect of colL to those which block it completely. In general, it appears that the ability of a sequence to block the effect of colL depends on both the length and G + C content of the fragment. The sequences which are responsible for the extrusion by the C-type pathway are termed C-type inducing sequences, while sequences which are interposed between the inducing sequence and the inverted repeat, and which may either augment or attenuate the effect, but which cannot function as inducing sequences in isolation, are termed transmitting sequences. The results of these studies are most readily consistent with long range destabilization of DNA structure via telestability effects.

Animals↗
PubMed1988

Sequence analysis of the NgoPII methyltransferase gene from Neisseria gonorrhoeae P9: homologies with other enzymes recognizing the sequence 5'-GGCC-3'.

Recombinant plasmids harbouring the functional M.NgoPII methyltransferase (specificity 5'-GGCC-3') were isolated from amplified gene libraries of gonococcal chromosomal DNA cloned in pBR322 and in Escherichia coli RR1. The M.NgoPII gene was localized by sub-cloning and the nucleotide sequence of a cloned 1.6 kb segment of Neisseria gonorrhoeae DNA harbouring the methylase gene was determined. This data, coupled with sub-cloning experiments and in vitro transcription-translation studies, indicates a theoretical size of 38.5 kd for the methylase protein. The predicted amino acid sequence of the methylase contains significant regions of homology with the projected sequences of other cytosine-modifying methylases, upon which the activity of these enzymes is likely to depend.

Amino Acid Sequence↗
PubMed1988

Helix stability and the mechanism of cruciform extrusion in supercoiled DNA molecules.

The kinetic properties of cruciform extrusion in supercoiled DNA molecules fall into two main classes. C-type cruciforms extrude in the absence of added salt, at relatively low temperatures, with large activation energies, while S-type cruciforms exhibit no extrusion in the absence of salt, and maximal rates at 50 mM NaCl, with activation energies about one quarter those of the C-type. These diverse properties are believed to reflect two distinct pathways for the extrusion process, and are determined by the nature of the sequences which form the context of the inverted repeat. C-type kinetics are conferred by A + T rich sequences, implying a role of helix stability in the selection. In this study we have shown that: 1. Helix-destabilising solvents (dimethyl formamide and formamide) facilitate extrusion by normally S-type molecules at low temperatures in the absence of salt. 2. C-type extrusion is strongly suppressed by low concentrations (2-4 microM) distamycin, at which concentrations S-type extrusion is enhanced. 3. Some extrusion occurs in a C-type construct in the presence of 50 mM NaCl. This is increased by addition of 3 microM distamycin, under which conditions extrusion becomes effectively S-type. Thus S-type constructs can behave in a quasi-C-type manner in the presence of helix-destabilising solvents, and C-type extrusion is suppressed by binding a compound which stabilises A + T rich regions of DNA. Helix destabilisation leads to C-type behaviour, while helix stabilisation results in S-type properties. These studies demonstrate the influence of contextual helix stability on the selection of kinetic mechanism of cruciform extrusion.

Bacteriocin Plasmids↗
PubMed1988

Ovarian function following marrow transplantation for aplastic anemia or leukemia.

One hundred eighty-seven women between 13 and 49 years of age had ovarian function evaluated from 1 to 15 years (median, 4) after marrow transplant for aplastic anemia or leukemia. Among 43 women transplanted for aplastic anemia following 200 mg/kg cyclophosphamide (CY), all 27 less than 26 years of age, but only five of 16 greater than 26 years of age recovered normal ovarian function. Nine of the 43 have had 12 pregnancies, resulting in eight live births, and two elective and two spontaneous abortions. All eight children are normal. Nine of 144 women transplanted for leukemia following 120 mg/kg CY and 9.20 to 15.75 Gy total body irradiation (TBI) recovered ovarian function. Two of these nine have had three pregnancies, resulting in two spontaneous and one elective abortion. The probability of having ovarian failure was 0.35 by 7 years for patients receiving CY alone and was 1.00 at 1 year for patients receiving CY plus TBI (P less than .0001). By 7 years after transplant the probabilities of having normal ovarian function were 0.92 after CY alone and 0.24 after CY plus TBI (P less than .0001). Multivariate analysis showed that TBI was the only factor significantly influencing ovarian failure and that both TBI and greater patient age at transplant were significantly associated with a decreased probability of recovering normal ovarian function. These data demonstrate that after high-dose CY, recovery of ovarian function occurs in younger women and in a minority of older women, but after CY and TBI, recovery occurs in only a few younger women and none of the older women.

Adolescent↗
PubMed1988

Prednisone and azathioprine compared with prednisone and placebo for treatment of chronic graft-v-host disease: prognostic influence of prolonged thrombocytopenia after allogeneic marrow transplantation.

We conducted a randomized, double-blind comparison of prednisone and placebo (group I) v prednisone and azathioprine (1.5 mg/kg/day) (group II) as early treatment of extensive chronic graft-v-host disease (GVHD). Patients with platelet counts less than 100,000/microL were placed into therapy with prednisone alone (group III). All three groups received identical doses of prednisone (1 mg/kg every other day) and one double-strength trimethoprim-sulfamethoxazole (TMP-SMX) tablet twice daily. Between January 1980 and December 1983, 179 previously untreated patients were enrolled and 164 were evaluable. Patients randomized to group I (n = 63) and group II (n = 63) were well matched for prognostic factors; those placed into group III (n = 38) had more frequent acute GVHD and progressive onset of chronic GVHD. Median duration of therapy was 2 years. Complications included diabetes (5%), aseptic necrosis (5%) and infection. For groups I, II, and III, the respective incidence of infection was disseminated varicella, 11%, 24%, 34%; bacteremia, 6%, 11%, 34%; and interstitial pneumonia, 5%, 14%, 18%. Recurrent malignancy was the most frequent cause of death and did not differ significantly across the groups. Nonrelapse mortality, however, did differ: 21% in group I, 40% in group II, and 58% in group III (I v II, P = .003; I v III, P = .001). Forty patients in group I, 30 in group II, and 10 in group III survive with a minimum follow-up of 3.8 years. Karnofsky performance scores for 68 survivors are 90% to 100%, scores for seven survivors are 70% to 89% and scores for five survivors are less than 70%. Actuarial survival at 5 years after transplant is 61% in group I, 47% in group II, and 26% in group III (I v II, P = .03; I v III, P = .0001). Treatment with prednisone alone results in fewer infections and better survival than prednisone and azathioprine in standard-risk chronic GVHD. Treatment with prednisone alone is less effective in high-risk patients with thrombocytopenia, and other strategies are required.

Adolescent↗
PubMed1988

Alternating-day cyclosporine and prednisone for treatment of high-risk chronic graft-v-host disease.

Therapy of chronic graft-v-host disease (GVHD) has been unsatisfactory in patients with platelet counts less than 100,000/microL. Survival at 5 years after marrow transplant is only 26% in such patients treated with trimethoprim-sulfamethoxazole (TMP-SMX) and every other day with prednisone. Since October 1982, 61 patients with high-risk extensive chronic GVHD were treated with a new alternating-day regimen of prednisone (1 mg/kg every other day) and oral cyclosporine (6 mg/kg every 12 hours every other day) with one double-strength TMP-SMX tablet twice daily. Forty patients (group I) received primary treatment of thrombocytopenic chronic GVHD (median platelet count 35 [range 7 to 87] x 10(3)/microL). Twenty-one patients (group II) received salvage treatment after failing initial prednisone +/- azathioprine. Twenty-one patients in group I and 15 in group II survive with a minimum of 2 years and a median of 3.7 years follow-up. At 4 years after transplant, actuarial survival is 51% (group I) and 67% (group II). Causes of death included interstitial pneumonia (six), relapse (five), GVHD without infection (five), infection (four), organ failure (three), and hemorrhage (two). Mortality increased with the progressive type onset of chronic GVHD and treatment failure. Toxicity included hypertension (13), nephrotoxicity (nine), nausea (seven), aseptic necrosis (five), neurologic abnormalities (four), and diabetes (three). Median cyclosporine levels at four and 36 hours were 296 and 64 ng/mL, respectively. Four patients required permanent discontinuation of cyclosporine, but none required renal dialysis. Karnofsky performance scores for 25 survivors are 90% to 100%, scores for six survivors are 70% to 89%, and scores for five survivors are less than 70%. Alternating-day cyclosporine and prednisone has acceptable toxicity and appears to improve survival in patients with high-risk chronic GVHD.

Adolescent↗
PubMed1988

Transfer of specific immunity in marrow recipients given HLA-mismatched, T cell-depleted, or HLA-identical marrow grafts.

The transfer of tetanus toxoid (TT) and diphtheria toxoid (DT) specific immunity was evaluated in 209 short-term (less than 120 days postgrafting) and 257 long-term (greater than 198 days postgrafting) non-boosted recipients after HLA-identical, HLA non-identical, and HLA-identical T cell-depleted marrow transplantation. TT or DT immunizations were not given to donors in the 6 months prior to transplant and the recipients received no immunizations post-transplantation. In 209 short-term recipients, 94% and 74% of recipients had detectable anti-TT and anti-DT titers respectively. In long-term recipients, 110 of 210 (52%) who received HLA-identical grafts, 17 of 38 (45%) who received HLA-non-identical grafts, and seven of seven (100%) who received HLA-identical T cell-depleted grafts had anti-TT titers; and 86 of 212 (40%) who received HLA-identical grafts, 11 of 38 (29%) who received HLA-non-identical grafts, and four of seven (57%) who received HLA-identical T cell-depleted grafts had anti-DT titers. When compared to non-boosted normal donor and control subjects, the magnitudes of anti-TT and anti-DT titers from the recipients were comparable to controls. These data show that transferred specific immunity is detectable in long-term recipients of T cell-depleted or HLA-non-identical grafts without immunizations of donors or recipients before or after transplantation.

Antibodies↗
PubMed1988

Use of thymic grafts or thymic factors to augment immunologic recovery after bone marrow transplantation: brief report with 2 to 12 years' follow-up.

Thymus tissue implants, thymic epithelial cells obtained from third party donors sharing one HLA-A and -B locus with the recipient, or the thymic hormones thymosin fraction 5 and thymopentin were given to recipients of HLA-identical sibling bone marrow to prevent chronic graft-versus-host disease (GVHD) and accelerate immunologic reconstitution. The clinical courses of 17 patients receiving thymus tissue and 18 patients receiving thymic hormones were reported initially 5 years ago and showed no difference in the incidence of chronic GVHD or immunologic recovery from those of concurrent or historical controls. We report here for the first time nine new patients who received thymus tissue implants with modifications of the culture method to lower the number of lymphocytes in the transplanted tissue with the intent of reducing rejection of the thymus tissue grafts. The clinical outcomes and immunologic functions of these nine patients were similar to those of the recipients of the earlier thymus tissue implants. With follow-up now ranging from 2.2 to 12.3 years (median 6.7) for the total group, 16 patients are alive. Seven never developed chronic GVHD. Nine were treated for chronic GVHD, seven of whom recovered and are leading normal lives, one has chronic pulmonary insufficiency, and one is disabled from chronic GVHD. We conclude that thymus tissue grafts or thymic epithelial cells partially HLA-matched to the recipient, thymosin fraction 5, or thymopentin used as described were not effective in reducing the incidence of chronic GVHD, improving immunologic recovery, or altering long-term survival.

Adolescent↗
PubMed1988

Graft failure in patients receiving T cell-depleted HLA-identical allogeneic marrow transplants.

Results of a previous study suggested that the risk of graft failure after transplantation of HLA-identical T cell-depleted marrow may be influenced by the preparative regimen. Subsequent clinical trials were carried out to clarify this relationship and to determine whether post-transplant immunosuppression could have an effect on graft durability. Two factors were found to be associated with graft failure. Patients with hematologic malignancy given a preparative regimen of cyclophosphamide (120 mg/kg) and 15.75 Gy fractionated total body irradiation (TBI) had a 27% cumulative incidence of graft failure, which was less than the 69% incidence seen previously in patients given cyclophosphamide and 12.0 Gy fractionated TBI (p less than 0.05, log-rank test). Patients with acute leukemia had a higher risk of graft failure than patients with chronic myelogenous leukemia (p less than 0.005). The incidence of graft failure was not influenced by post-transplant immunosuppression with cyclosporine, methotrexate or a combination of cyclosporine plus methotrexate or by the omission of all post-transplant immunosuppression. Similarly, graft failure was not associated with the complement lot used for marrow treatment, the recovery of BFU-E or CFU-GM, or with the number of nucleated cells or T cells in the graft. The effect of primary diagnosis and the inverse relationship between the amount of pretransplant TBI and the graft failure rate suggest that a host factor may have been involved in a presumably immune-mediated rejection. This observation further leads to the inference that certain T cells present in donor marrow can suppress host immunity or help to maintain function of the graft.

Adult↗
PubMed1988

HLA-identical marrow transplantation during accelerated-phase chronic myelogenous leukemia: analysis of survival and remission duration.

Results of HLA-identical allogeneic marrow transplantation were analyzed for 66 patients with accelerated-phase chronic myelogenous leukemia (CML). Multivariate proportional hazards regression models were used to determine disease-related and transplant-related factors associated with posttransplant mortality and relapse. The projected 5-year survival rate was estimated at 18% by the product-limit method. The major causes of death were interstitial pneumonia, infection, and relapse. Splenomegaly at initial diagnosis and longer time interval from diagnosis to transplant were associated with decreased overall survival and event-free survival. Sixteen patients have relapsed between 17 and 1,569 days (median, 486) posttransplant. The use of T-cell-depleted marrow and older age of the donor or recipient were associated with an increased probability of leukemic relapse. Ten of the 16 relapses occurred among the 15 patients who received T-cell-depleted marrow. The actuarial relapse risk 2.5 years posttransplant was 100% in patients administered T-cell-depleted marrow as compared with 25% in patients administered unmodified marrow. The data in this report emphasize the increased risks and relatively poor results that occur when marrow transplantation is deferred until after signs of acceleration appear. When compared with results for patients who received transplants during chronic phase, the poor results seen here in patients administered unmodified marrow stem primarily from increased transplant-related mortality rather than increased relapse risk. The strikingly increased relapse rate associated with the use of T-cell depletion would discourage its use for graft-v-host disease prevention in patients who receive transplants for CML.

Adolescent↗
PubMed1988

Allogeneic marrow transplantation for children with juvenile chronic myelogenous leukemia.

Fourteen children between the ages of 2 and 5 years with juvenile chronic myelogenous leukemia were given cyclophosphamide, total-body irradiation, and marrow transplants. Unmodified marrow was given to six patients who received marrow from HLA-identical siblings and eight patients who received marrow from family members HLA identical for one haplotype but mismatched for one to three loci on the nonshared haplotype. Five patients died of transplant-related complications, and three relapsed at 48, 81, and 1,670 days posttransplant and died of leukemia. Six patients survive in continuous remission from 0.5 to 11.5 years posttransplant.

Bone Marrow Transplantation↗
PubMed1987

Immunoglobulin therapy in bone marrow transplantation.

Following ablative treatment with supralethal doses of chemotherapy and total body irradiation, patients demonstrate multiple immunologic deficiencies after bone marrow transplantation. Immune function usually recovers and the risk of infection decreases within six to 12 months. However, patients in whom chronic graft-versus-host disease (GVHD) develops have persisting B and T cell abnormalities, and in vivo and in vitro studies show impaired immunoglobulin regulation and function despite normal levels of serum immunoglobulin G. This review summarizes 12 published clinical trials of immunoglobulin therapy to correct immunodeficiency and prevent infection after marrow grafting. In five controlled studies, cytomegalovirus infection developed in a total of 52 of 172 (30 percent) immunoglobulin recipients and 71 of 165 (43 percent) control patients not given globulin. In four controlled trials, interstitial pneumonia developed in a total of 21 of 127 (17 percent) immunoglobulin recipients and 40 of 94 (43 percent) control patients. Three randomized trials reported a reduced rate of GVHD or post-engraftment septicemia in immunoglobulin recipients. However, methods of immunoglobulin preparation, antibody titer, and dose and schedule of prophylaxis varied widely in these studies, as did other critical patient, transplant regimen, and supportive care factors. Accordingly, data should be interpreted with caution. Ongoing controlled clinical trials will further define the proper role of immunoglobulin therapy in bone marrow transplantation.

Bacterial Infections↗