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Biomedical subjects

B Sundberg

Publications and source records attributed to B Sundberg.

At least 73 records · Page 4Linked to original sources
PubMed1991

Methotrexate combined with cyclosporin A decreases graft-versus-host disease, but increases leukemic relapse compared to monotherapy.

Forty patients with leukemia receiving HLA-identical sibling marrow and treated with four doses of methotrexate (MTX) in combination with cyclosporin A (CSA) for prevention of graft-versus-host disease (GVHD) were compared with retrospective controls consisting of 57 patients treated with MTX alone and 30 patients treated with CSA alone. Follow-up time ranged from 2.6 to 6.7 years after bone marrow transplantation. Patients in the MTX + CSA group were older and received a smaller marrow cell dose, but were otherwise comparable regarding disease status, donor/recipient sex match and seropositivity for cytomegalovirus (CMV) and other herpes viruses. Engraftment was slowest in the MTX + CSA group and fastest in the CSA group (p = 0.005 vs MTX and p less than 0.001 vs CSA). The incidence of moderate to severe acute GVHD (grade II-IV) was 8% among patients on MTX + CSA and 26% and 47% in the MTX (p = 0.028) and CSA (p = 0.0001) groups respectively. The corresponding figures for chronic GVHD were 25, 42 and 40% (n.s.). The incidence of CMV interstitial pneumonia was 0% in patients treated with MTX + CSA compared to 23% in the MTX treated patients (p = 0.01) and 11% in the CSA treated patients (p = 0.05). The actuarial 3-year survival in the three groups was similar, 56% for the MTX + CSA patients and 53% for both the MTX and CSA patients (n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Prevention of graft-versus-host disease with T cell depletion or cyclosporin and methotrexate. A randomized trial in adult leukemic marrow recipients.

In adult leukemic marrow recipients of HLA identical sibling marrow, 23 patients were randomized to T cell depletion and 25 received cyclosporin (CSA) and four doses of methotrexate (MTX) to prevent graft-versus-host disease (GVHD). Anti-CD8 and anti-CD6 antibodies plus complement depleted 95.3 +/- 5.8% (mean +/- SE) CD3 cells. All patients engrafted except one who died early. Patients receiving T cell-depleted marrow had a faster time to 0.2 x 10(9) WBC/l (p less than 0.001), but required more erythrocyte units (p = 0.03). Platelet transfusions, infections and time in hospital did not differ. The incidence of grade II-III acute GVHD was 23% following T cell depletion and 12% for those receiving CSA + MTX. Chronic GVHD occurred in 51% and 23% in the two groups, respectively (p = 0.06). Recipients of T cell-depleted marrow who developed grade I-III acute GVHD received more T cells compared to those without acute GVHD (p = 0.02). The major cause of death in both groups was relapse, the cumulative incidence of which, at 4 years, was 39% in the recipients of T cell-depleted marrow and 54% in the CSA + MTX group. The 3-year actuarial leukemia-free survival was 42% and 44% in the two respective groups.

Adult↗
PubMed1990

Induction of acropetal (14)C-photosynthate transport and radial growth by indole-3-acetic acid in Pinus sylvestris shoots.

The relationship between radial growth and assimilate movement was determined in one-year-old Pinus sylvestris (L.) cuttings collected during the dormant period and reactivated for 1-27 days under environmental conditions favorable for growth. The cuttings were either left with buds intact, defoliated along the distal 8 cm, or debudded and treated apically with 0 or 1 mg g(-1) indole-3-acetic acid (IAA) in lanolin. Radial growth was measured as tracheid production and bark radial width. The distribution of (14)C-photosynthate 1 or 5 days after exposure to (14)CO(2) was used to indicate assimilate movement. Debudding inhibited tracheid production and decreased acropetal (14)C-photosynthate transport, whereas applying IAA to debudded cuttings promoted both these processes and, in addition, induced vigorous callus growth within the bark immediately below the application point. Distal defoliation markedly increased the amount of (14)C-photosynthate transported toward the apex without altering how debudding and exogenous IAA affected tracheid production and the distribution of (14)C-photosynthate. The production of tracheids induced by apically applied IAA in debudded and distally defoliated cuttings increased progressively in material collected on September 9, October 14 and November 24, whereas bark radial width and acropetal (14)C-photosynthate movement increased only between the first two collection dates. Ringing midway between the IAA source and the bottom of the distally defoliated region with a lanolin mixture of 10 mg g(-1)N-1-naphthylphthalamic acid (NPA), 1 mg g(-1) methyl-2-chloro-9-hydroxy-fluorene-9-carboxylic acid (CF) or 10 mg g(-1) phenylacetic acid (PAA) reduced radial growth and [1-(14)C]IAA transport below the ring and locally promoted radial growth and accumulated radioactivity above. (14)C-Photosynthate transport into the region above the ring either was not altered (CF, PAA) or was increased (NPA). The results indicate that apically applied IAA induces the acropetal movement of (14)C-photosynthate in debudded P. sylvestris shoots by locally promoting activity correlated with tracheid and callus production rather than by affecting radial growth or phloem transport processes, or both, at a distance below the IAA source.

Journal Article↗
PubMed1990

Distribution of Indole-3-Acetic Acid and the Occurrence of Its Alkali-Labile Conjugates in the Extraxylary Region of Pinus sylvestris Stems.

Free and conjugated indole-3-acetic acid (IAA) were measured by quantitative gas chromatography-selected ion monitoringmass spectrometry in the extraxylary region of the stem of large Pinus sylvestris (L.) trees during the annual cycle of cambial activity and dormancy. The extraxylary region at the stem top and bottom was divided into 3 and 4 fractions, respectively, for the free IAA measurements, while the entire extraxylary region was extracted when the IAA-conjugates were analyzed. The effect on the distribution pattern of expressing IAA level as a concentration (per gram fresh weight or dry weight) and as total amount (per square centimeter) was examined. The IAA level was much higher in the cambial region than in the fractions that contained the nonfunctional phloem and the periderm. The largest IAA concentration occurred in the fraction that included the cambium, whereas the total amount of IAA was greatest in the phloemcontaining fraction. The significance of the nonuniform radial distribution of IAA for estimating the IAA concentration in the cambial region is discussed in relation to how the cambial region is sampled. A slight Iongitudinal gradient in IAA concentration, decreasing from the top to the bottom of the stem, was observed in the cambial region when the cambium was in the grand period of activity, but not at the end of the cambial growing period. In all fractions, the total amount of IAA was highest when the cambium was active. However, the IAA concentration in the cambial region did not follow the same pattern, actually being lowest during the tracheid production period at the stem bottom. IAA conjugates were detected on all sampling dates except June 23, but their concentrations were always less than 14% of that of free IAA, and their occurrence did not obviously vary during the year. In general, there was a higher concentration of ester conjugates than of amide conjugates, and the ester conjugates were more abundant at the top of the stem than at the bottom.

Journal Article↗
PubMed1990

Tracheid production in response to changes in the internal level of indole-3-acetic Acid in 1-year-old shoots of scots pine.

Different concentrations of indole-3-acetic acid (IAA) were applied in lanolin to 1-year-old shoots of Pinus sylvestris (L.) in a manner known to stimulate cambial activity. The internal concentration of free IAA was measured at a distance below the application point by combined gas chromatography-selected ion monitoring-mass spectrometry using [(13)C(6)]IAA as a quantitative internal standard, and related to the production of tracheids at the same site. The experiment was performed with: (a) debudded cuttings, where the major source of endogenous IAA, the apical buds, were replaced with exogenous IAA, and (b) intact, attached shoots, where endogenous IAA was supplemented by applying IAA around the circumference of the shoot. In both experimental systems, an increase in the internal IAA level was positively related to increased tracheid production. It was also demonstrated that the concentration of internal IAA measured at the sampling site was comparable with endogenous IAA levels found in intact control shoots, and that a wide range of applied IAA concentrations was associated with a relatively small range of internal IAA levels.

Journal Article↗
PubMed1989

Pretransplant herpes virus serology and chronic graft-versus-host disease.

The influence of pretransplant herpes virus antibodies in patients and donors in the subsequent development of chronic graft-versus-host disease (GVHD) was analysed in 150 consecutive HLA identical bone marrow recipients. The Cox regression bivariate analysis showed that (i) pretransplant seropositivity for cytomegalovirus (CMV) in the patients and the donors, (ii) donor seropositivity for herpes simplex virus and Epstein-Barr virus, (iii) high donor and patient age, (iv) a previous grade II-IV acute GVHD, (v) patients receiving unirradiated donor buffy coat cells post-transplant, (vi) overall CMV infection, (vii) high donor herpes virus load (positive serology for 3-4 herpes viruses versus 0-2), and (viii) high recipient herpes virus load prior to BMT were all associated with a high incidence of chronic GVHD. In Cox regression multivariate analysis, high pretransplant donor herpes virus load (p less than 0.001) and a previous grade II-IV acute GVHD (p = 0.02) were the strongest predictors of chronic GVHD. Thus, herpes virus immune cells in the donated marrow may play a role in the pathophysiology of chronic GVHD.

Adolescent↗
PubMed1989

Variables predicting deep fungal infections in bone marrow transplant recipients.

Deep fungal infections (FI) were diagnosed in 27 out of 209 consecutive bone marrow transplantation (BMT) recipients. Autopsy verified that the incidence of deep FI was 10% and the overall incidence was 13%. Using bivariate logistic regression analysis at the time of BMT, high recipient age (p = 0.003), low bone marrow cell dose (p = 0.007), recipient cytomegalovirus (CMV) seropositivity (p = 0.009) and splenectomy (p = 0.03) were significant risk factors for deep FI. In multivariate analysis, splenectomy (p = 0.008), recipient CMV seropositivity (p = 0.01) and low bone marrow cell dose (p = 0.01) held as significant. At 30 days post-BMT anti-thymocyte globulin treatment (p = 0.0006) and graft-versus-host disease grade II-IV (p = 0.005) were significant risk variables in bivariate logistic regression analysis and Fisher's exact probability test. Patients with these risk factors are candidates for treatment with antifungal drugs when they suffer from leukopenia and unclear fever.

Adolescent↗
PubMed1988

Pretransplant herpesvirus serology and acute graft-versus-host disease.

Logistic regression was used to analyze the influence of pretransplant herpesvirus antibodies, in both patients and donors, on the development of acute graft-versus-host disease in 111 consecutive HLA-identical bone marrow recipients. In bivariate analysis, recipient seropositivity for cytomegalovirus (P = 0.01), donor seropositivity for herpes simplex virus (P = 0.02), and low bone marrow cell dosage (P less than 0.05) were associated with a high incidence of grade II-IV acute GVHD. In multivariate analysis the P values were P less than 0.05 for a positive recipient CMV serology and P = 0.07 for a positive donor HSV serology. Positive serology for 1-2 herpes-viruses among recipients or donors both resulted in a 12% incidence of grade II-IV acute GVHD. Positive serology for 3-4 herpesviruses among patients or donors resulted in an incidence of 32% and 38% of acute GVHD, respectively (P less than 0.05). It is concluded that recipient and donor pretransplant herpesvirus immunity can be used to calculate the risk of moderate-to-severe acute GVHD.

Acute Disease↗
PubMed1988

Allogeneic bone marrow transplantation for leukemia: factors of importance for long-term survival and relapse.

From 1977 until June 1987, 139 patients with leukemia underwent allogeneic bone marrow transplantation at Huddinge Hospital. Among recipients of HLA identical bone marrow the survival plateau for 30 patients with acute myeloid leukemia in first remission was 71% from 3 to 7 years. Children (n = 11) had a survival of 100% compared with 52% (n = 19) in adults (p = 0.01). Among patients with acute lymphoblastic leukemia in first remission (n = 15) the actuarial 5-year survival was 73% compared with 31% for those (n = 25) in second to fourth remissions. The probability of relapse in these two groups was 9% and 45% respectively (p less than 0.05). Patients with chronic myeloid leukemia in first chronic phase (n = 27) had a survival plateau from 1 to 6 years of 65%. In Cox's multivariate regression analysis, improved survival was associated with grade 0-I acute graft-versus-host disease (GVHD) (p less than 0.0001), HLA-matched siblings (p less than 0.001), recipient age less than 17 years (p = 0.02), first remission and first chronic phase (p = 0.03), cytomegalovirus (CMV) seronegative recipients (p = 0.04) and absence of symptomatic CMV infection (p = 0.04). A decreased risk of relapse was seen in patients with first remission or first chronic phase (p less than 0.001) and in patients with asymptomatic CMV infection (p = 0.03). In multivariate analysis the p values were 0.002 and 0.09 for these two groups respectively. In these patients acute GVHD was the major obstacle to successful outcome.

Adolescent↗