Isotope correction of mass spectrometry profiles.

Isotope correction of a profile is an important step in the analysis of mass spectrometry derived data. The problem is mathematically formulated as a system of linear equations which is general enough to include previous correction methods. For the solution of these equations when applied to the whole profile an efficient algorithm is developed. In experimental tests the resulting algorithm corrected the profile fast and successfully.

Towards functional transplant donor matching by measurement of granzyme A and granzyme B production levels.

Graft-versus-host disease (GvHD) can be a major complication after allogeneic stem cell transplantation (SCT) especially when donor and recipient are unrelated. The latter serious complication, together with the growing number of available unrelated stem cell donors, demand a simple in vitro assay for functional stem cell donor selection. Activated donor cytotoxic T lymphocytes (CTLs) and natural killer cells produce granzymes (Gr) that are involved in the pathogenesis of GvHD. We measured granzymes A and B (GrA and GrB) production levels in the supernatants of 96 h pretransplant mixed lymphocyte cultures (MLC) of 26 sibling and 31 unrelated patient/donor pairs by enzyme-linked immunosorbent assay (ELISA). In detail, the GrA and GrB production levels from a selected cohort of 37 potential patient/donor pairs were correlated with relative responses (RR) of MLC and with human leukocyte antigen (HLA) class II mismatches and with the development of acute GvHD in a second, consecutive cohort of 20 sibling SCT recipients. In vitro measurement of GrA and GrB production levels significantly correlated with the RR of pretransplant MLC (r=0.492, p< or =0.01 and r=0.853, p< or =0.01, respectively) and increased with the number of HLA class II mismatches between patient and donor. Pretransplant GrA production levels were significantly associated with the in vivo development of acute GvHD grades II-IV in patients transplanted with an HLA-identical sibling donor (p< or =0.001). In conclusion, in vitro GrA and GrB production levels can be measured by a quantitative and sensitive ELISA. This novel and simple method may be used for functional selection of unrelated stem cell donors and for the identification of patients who are at risk for acute GvHD grades II-IV.

No predictive value of cytotoxic or helper T-cell precursor frequencies for outcome when analyzed from the graft after stem cell transplantation.

The predictive value of limiting dilution analyses (LDA) measuring cytotoxic and helper T-lymphocyte precursor (CTLp and HTLp) frequencies for outcome after stem cell transplantation (SCT) is still a matter of debate. One reason may be that CTLp and HTLp frequencies are determined in peripheral blood mononuclear cells (PBMC) and this responder cell population does not reflect the cell type composition of the graft. We assessed whether CTLp and HTLp LDA can predict complications after human leukocyte antigen (HLA)-identical SCT when CTLp and HTLp frequencies are analyzed in PBMC of the respective stem cell graft [bone marrow (BMMC) or granulocyte colony-stimulating factor (G-CSF)-mobilized PBMC] and compared to PBMC of PB. Host-specific CTLp frequencies measured in 25 patients and HTLp frequencies analyzed in 6 patients were low in all responder cell sources. CTLp and HTLp frequencies seen against HLA-mismatched unrelated third-party cells were high, but third-party-specific CTLp and HTLp frequencies were lower in G-CSF-PBMC than in PBMC ( p=0.047 for CTLp frequencies). Host-specific CTLp frequencies analyzed in all responder cell sources did not predict acute or chronic graft-versus-host disease (GVHD). Lower CTLp frequencies were detected in all responder cell sources from patients who relapsed after SCT than in patients without relapse, but the differences between both groups were statistically significant only in PBMC. In conclusion, a significant correlation was detected only between relapse and CTLp frequencies measured in PBMC. The lower frequency of third-party-specific cells in G-CSF-PBMC indicates that the mobilization procedure with G-CSF itself may influence results.

Risk for cytomegalovirus infection following reduced intensity allogeneic stem cell transplantation.

Preliminary data suggest a faster immune recovery following non-myeloablative stem cell transplantation because of the persistence of recipient T cells, but the real impact on post-transplant infectious complications remains unknown. We retrospectively analysed the incidence of cytomegalovirus (CMV) infection in twenty patients following reduced intensity conditioning with busulfan/fludarabine+/-thiotepa and post-transplant immunosuppression with cyclosporine A/mycophenolate mofetil. Results were compared with 20 patients receiving myeloablative transplants during the same time period and who were matched for CMV risk group and for donor origin. The cumulative incidence of CMV infection following reduced intensity vs. myeloablative transplants was 60.4% vs. 40.0%, respectively (p value 0.1, log rank test). The risk for CMV infection in both cohorts was increased after in vivo T cell depletion with antithymocyte globulin (75% and 60%, respectively). Acute GVHD preceded the diagnosis of CMV infection by a median of 25 (range, 9-61) days following reduced intensity transplants and a median of 14 (range, 10-34) days in myeloablative transplants. Recurrent CMV infections were observed only in patients receiving reduced intensity transplants. Using multivariate analysis only reduced intensity transplantation and in vivo T cell depletion had a significant impact on the risk of CMV infection. In our series the incidence for CMV infection following reduced intensity transplants seems to be increased as compared with risk-matched myeloablative transplants. When adding anti-T cell antibodies to the conditioning regimen, the risk for CMV infection increases by up to 75%. Thorough studies of the risk of post-transplant viral infection are necessary to optimize surveillance as well as pre-emptive and/or prophylactic treatment strategies in the non-myeloablative transplantation setting.

Perinatal bone turnover in term human neonates and the influence of maternal smoking.

Bone turnover in neonates appears independently of the comparably low maternal bone turnover, but there is only sparse information on the effect of the in utero environment on fetal bone turnover. Postnatally, the resuming growth velocity and alterations in mineral homeostasis affect neonatal bone turnover. This study evaluated the relationship of bone marker concentrations to maternal and fetal auxological variables as well as maternal smoking and assessed the short-term change in bone markers during the first days of life. Serum markers of bone formation [osteocalcin and bone-specific alkaline phosphatase (BALP)] and bone resorption (C-terminal telopeptide of type I collagen) were measured in cord blood and at discharge (median d 3) in 69 healthy term neonates. Concentrations of BALP were significantly lower in neonates of smokers (n = 16) compared with nonsmokers (n = 53), both at birth (p = 0.013) and at discharge (p = 0.036). Both cord osteocalcin and BALP were negatively related to maternal weight and maternal body mass index. Maternal smoking and pregnancy weight gain were the predictors of cord BALP (r2 = 0.24; p < 0.001), whereas the mode of delivery best predicted cord C-terminal telopeptide of type I collagen levels (r2 = 0.19; p < 0.001). C-terminal telopeptide of type I collagen and osteocalcin increased significantly (p < 0.001) from birth to discharge, whereas BALP levels did not change significantly during the same period. Our results suggest that maternal smoking during pregnancy and maternal obesity may have a negative impact on fetal bone formation. The significant increase of osteocalcin and C-terminal telopeptide of type I collagen may result either from an increase in bone turnover or altered renal clearance.

About the relationship between basic numerical processing and arithmetics in early Alzheimer's disease--a follow-up study.

We studied the relationship between basic numerical knowledge and arithmetics (facts and procedures) in early Alzheimer's Disease (AD). In most patients, basic numerical knowledge was found to be preserved, as reflected by low error rates, distance effect in number comparison, and subitizing in naming numerosities. However, within arithmetics, AD patients exhibited decreased fact and procedural knowledge. Interestingly, double dissociations were found not only between facts and procedures but also between basic numerical knowledge and arithmetics. Thus, our results suggest that basic numerical knowledge need not be a prerequisite for the maintenance of arithmetics, but rather corroborate calculation models that postulate the functional independence of its components. Further, we found patient specific error types which might serve to identify early AD. The follow-up about one year later indicated significant qualitative, but only marginal quantitative performance changes.

Prognostic significance of Ep-CAM AND Her-2/neu overexpression in invasive breast cancer.

To assess the frequency and prognostic impact of Ep-CAM and Her-2/neu overexpression in patients with breast cancer and to determine its relationship with other prognostic markers, 205 breast cancer patients with a median follow-up of 10.8 years were enrolled in this retrospective study. Overexpression of Ep-CAM and Her-2/neu in tumor tissue samples was assessed by immunohistochemistry. Tumors presenting a Her-2/neu 2+ staining were additionally analyzed by FISH to exclude false positive results. Ep-CAM and Her-2/neu overexpression was found in 35.6% and 19.5% of the tumor samples, respectively. Both Ep-CAM and Her-2/neu overexpression were predictive for poor disease-free (DFS) and disease-related overall survival (DROS). Concurrent Ep-CAM and Her-2/neu overexpression was present in 13.2% of tumor specimens and had an additive negative impact on DFS and DROS. This minority of patients had a median time to relapse of only 34 months, whereas the median time to relapse was not reached in the patient population without Her-2/neu and Ep-CAM overexpression. By multivariate analysis Ep-CAM overexpression proved to be an indicator of poor prognosis, independent of tumor size, histologic grade, hormone receptor expression and Her-2/neu overexpression. In conclusion, overexpression of Ep-CAM and Her-2/neu complement each other as predictors for poor prognosis in patients with invasive breast cancer. Determination of these tumor markers should help in assigning breast cancer patients to 1 of 3 distinct risk categories.

Randomized double blind trial of an extract from the pentacyclic alkaloid-chemotype of uncaria tomentosa for the treatment of rheumatoid arthritis.

OBJECTIVE: To evaluate safety and clinical efficacy of a plant extract from the pentacyclic chemotype of Uncaria tomentosa (UT) in patients with active rheumatoid arthritis (RA). METHODS: Forty patients undergoing sulfasalazine or hydroxychloroquine treatment were enrolled in a randomized 52 week, 2 phase study. During the first phase (24 weeks, double blind, placebo controlled), patients were treated with UT extract or placebo. In the second phase (28 weeks) all patients received the plant extract. RESULTS: Twenty-four weeks of treatment with the UT extract resulted in a reduction of the number of painful joints compared to placebo (by 53.2% vs 24.1%; p = 0.044). Patients receiving the UT extract only during the second phase experienced a reduction in the number of painful (p = 0.003) and swollen joints (p = 0.007) and the Ritchie Index (p = 0.004) compared to the values after 24 weeks of placebo. Only minor side effects were observed. CONCLUSION: This small preliminary study demonstrates relative safety and modest benefit to the tender joint count of a highly purified extract from the pentacyclic chemotype of UT in patients with active RA taking sulfasalazine or hydroxychloroquine.

The role of L-alanyl-L-glutamine in the immune response in vitro.

INTRODUCTION: The amino acid glutamine plays an important role in the immune system by providing energy and precursors for biosynthetic processes. For lack of stability it could not so far be generally supplied in total parenteral nutrition. The development of dipeptides consisting of glutamine and a second amino acid offers a solution to this problem. METHODS: In vitro effects of the dipeptide L-alanyl-L-glutamine on different cells of the immune system are assessed and compared to those of glutamine on its own. RESULTS: T-lymphocyte proliferation stimulated with mitogens and alloantigens increased significantly and dose-dependently after addition of L-alanyl-L-glutamine or glutamine. Maximal effects were observed with a concentration of 2 mmol/l of either substance. The stimulatory effects were partly attributed to enhanced cytokine production following glutamine or L-alanyl-L-glutamine treatment. In contrast, the activity of natural killer and cytotoxic T-cells was not influenced by neither amino acid at concentrations of 0.2 and 2 mmol/l, and suppressed at 20 mmol/l. In all experiments, early addition of the amino acids to the cultures proved crucial. CONCLUSION: In this series of in vitro experiments the dipeptide L-alanyl-L-glutamine exerted almost identical immunostimulatory activities to glutamine alone. Its provision in parenteral nutrition appears commendable.