Rituximab in auto-immune haemolytic anaemia and immune thrombocytopenic purpura: a Belgian retrospective multicentric study.

OBJECTIVES: For better characterizing the effect of anti-CD20 therapy, we analysed the use of rituximab in Belgian patients experiencing auto-immune haemolytic anaemia (AIHA) and immune thrombocytopenic purpura (ITP). DESIGN: We performed a retrospective multicentric analysis of patients with AIHA and ITP treated with rituximab in Belgium. SETTING: Haematological departments were invited to fill in a questionnaire about patient and disease characteristics. SUBJECTS: All patients with AIHA and ITP, both primary and secondary to other diseases, who received one or more courses of rituximab during their disease course were included. Sixty-eight courses of rituximab in 53 patients with AIHA and 43 courses in 40 patients with ITP were analyzed. INTERVENTION: Response rates, duration of response and factors predictive for response were assessed. RESULTS: All patients were given rituximab after failing at least one previous line of treatment, including splenectomy in 19% and 72.5% of AIHA-patients and ITP-patients respectively. Overall response rates were 79.2% in AIHA and 70% in ITP, with a median follow-up since first rituximab administration of 15 months (range 0.5-62) in AIHA and 11 months (range 0-74) in ITP. Progression free survival at 1 and 2 years were 72% and 56% in AIHA and 70% and 44% in ITP. In this retrospective analysis we were not able to identify pretreatment characteristics predictive for response to rituximab. Nine patients with AIHA and three patients with ITP were given one or more additional courses of rituximab. Most of these patients, who had responded to a previous course, experienced a new response comparable to the previous one, both in terms of quality and of duration of response. Finally, the outcome of patients who failed to respond to rituximab therapy was poor both in terms of response to subsequent therapy and in terms of survival. CONCLUSIONS: This study confirms that rituximab induces responses in a majority of previously treated patients with AIHA and ITP. Response duration generally exceeds 1 year. Retreatment with rituximab in responding patients is most often successful. The outcome of patients who fail on rituximab is poor. We were not able to identify pretreatment patient characteristics predicting for response.

[Developmental trajectories of anxiety disorder symptoms in adolescents: a five-year prospective community study]. / Ontwikkelingstrajecten van angstsymptomen: een vijfjarig prospectief onderzoek onder adolescenten uit de algemene populatie.

BACKGROUND: The relatively recent adoption of modern statistical analysis methods, such as latent growth modelling (lgm), makes it possible to study differences in the individual trajectories of development over time. AIM: To examine prospectively the developmental trajectories of anxiety disorder symptoms in a large sample of adolescents (N = 1,318) from the general population over a period of five years. METHOD: The adolescents were divided into two cohorts: early adolescents (average age 12 at the first measurement) and middle adolescents (average age 16 at the first measurement). Age and gender differences in the developmental trajectories of adolescent anxiety disorder symptoms over time were examined by means of lgm. results Over the course of five years there was a slight decrease in panic disorder, school anxiety and separation anxiety disorder symptoms for all adolescents, with the exception of social phobia symptoms, which remained fairly stable over time. Adolescent girls showed a slight increase in generalised anxiety disorder symptoms over time, whereas these symptoms decreased among adolescent boys. CONCLUSION: The use of individual trajectory-based analyses, enabled us to study advance our understanding of age and gender differences in the development of adolescent anxiety symptoms.

Yeast exosome mutants accumulate 3'-extended polyadenylated forms of U4 small nuclear RNA and small nucleolar RNAs.

The exosome is a protein complex consisting of a variety of 3'-to-5' exonucleases that functions both in 3'-to-5' trimming of rRNA precursors and in 3'-to-5' degradation of mRNA. To determine additional exosome functions, we examined the processing of a variety of RNAs, including tRNAs, small nuclear RNAs (snRNAs), small nucleolar RNAs (snoRNAs), RNase P, RNase MRP, and SRP RNAs, and 5S rRNAs in mutants defective in either the core components of the exosome or in other proteins required for exosome function. These experiments led to three important conclusions. First, exosome mutants accumulate 3'-extended forms of the U4 snRNA and a wide variety of snoRNAs, including snoRNAs that are independently transcribed or intron derived. This finding suggests that the exosome functions in the 3' end processing of these species. Second, in exosome mutants, transcripts for U4 snRNA and independently transcribed snoRNAs accumulate as 3'-extended polyadenylated species, suggesting that the exosome is required to process these 3'-extended transcripts. Third, processing of 5.8S rRNA, snRNA, and snoRNA by the exosome is affected by mutations of the nuclear proteins Rrp6p and Mtr4p, whereas mRNA degradation by the exosome required Ski2p and was not affected by mutations in RRP6 or MTR4. This finding suggests that the cytoplasmic and nuclear forms of the exosome represent two functionally different complexes involved in distinct 3'-to-5' processing and degradation reactions.

Function of the ski4p (Csl4p) and Ski7p proteins in 3'-to-5' degradation of mRNA.

One of two general pathways of mRNA decay in the yeast Saccharomyces cerevisiae occurs by deadenylation followed by 3'-to-5' degradation of the mRNA body. Previous results have shown that this degradation requires components of the exosome and the Ski2p, Ski3p, and Ski8p proteins, which were originally identified due to their superkiller phenotype. In this work, we demonstrate that deletion of the SKI7 gene, which encodes a putative GTPase, also causes a defect in 3'-to-5' degradation of mRNA. Deletion of SKI7, like deletion of SKI2, SKI3, or SKI8, does not affect various RNA-processing reactions of the exosome. In addition, we show that a mutation in the SKI4 gene also causes a defect in 3'-to-5' mRNA degradation. We show that the SKI4 gene is identical to the CSL4 gene, which encodes a core component of the exosome. Interestingly, the ski4-1 allele contains a point mutation resulting in a mutation in the putative RNA binding domain of the Csl4p protein. This point mutation strongly affects mRNA degradation without affecting exosome function in rRNA or snRNA processing, 5' externally transcribed spacer (ETS) degradation, or viability. In contrast, the csl4-1 allele of the same gene affects rRNA processing but not 3'-to-5' mRNA degradation. We identify csl4-1 as resulting from a partial-loss-of-function mutation in the promoter of the CSL4 gene. These data indicate that the distinct functions of the exosome can be separated genetically and suggest that the RNA binding domain of Csl4p may have a specific function in mRNA degradation.

Long-term results of the R-CHOP study in the treatment of elderly patients with diffuse large B-cell lymphoma: a study by the Groupe d'Etude des Lymphomes de l'Adulte.

PURPOSE: To analyze the long-term outcome of patients included in the Lymphome Non Hodgkinien study 98-5 (LNH98-5) comparing cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) to rituximab plus CHOP (R-CHOP) in elderly patients with diffuse large B-cell lymphoma. PATIENTS AND METHODS: LNH98-5 was a randomized study that included 399 previously untreated patients, age 60 to 80 years, with diffuse large B-cell lymphoma. Patients received eight cycles of classical CHOP (cyclophosphamide 750 mg/m(2), doxorubicin 50 mg/m(2), vincristine 1.4 mg/m(2), and prednisone 40 mg/m(2) for 5 days) every 3 weeks. In R-CHOP, rituximab 375 mg/m(2) was administered the same day as CHOP. Survivals were analyzed using the intent-to-treat principle. RESULTS: Median follow-up is 5 years at present. Event-free survival, progression-free survival, disease-free survival, and overall survival remain statistically significant in favor of the combination of R-CHOP (P = .00002, P < .00001, P < .00031, and P < .0073, respectively, in the log-rank test). Patients with low-risk or high-risk lymphoma according to the age-adjusted International Prognostic Index have longer survivals if treated with the combination. No long-term toxicity appeared to be associated with the R-CHOP combination. CONCLUSION: Using the combination of R-CHOP leads to significant improvement of the outcome of elderly patients with diffuse large B-cell lymphoma, with significant survival benefit maintained during a 5-year follow-up. This combination should become the standard for treating these patients.

Translocation t(1;6)(p35.3;p25.2): a new recurrent aberration in "unmutated" B-CLL.

Although reciprocal chromosomal translocations are not typical for B-cell chronic lymphocytic leukemia (B-CLL), we identified the novel t(1;6)(p35.3;p25.2) in eight patients with this disorder. Interestingly, all cases showed lack of somatically mutated IgV(H). Clinical, morphological, immunologic, and genetic features of these patients are described. Briefly, the age ranged from 33 to 81 years (median: 62.5 years) and the sex ratio was 6M:2F. Most of the patients (6/8) presented with advanced clinical stage. Therapy was required in seven cases. After a median follow-up of 28 months, five patients are alive and three died from disease evolution. Three cases developed transformation into diffuse large B-cell lymphoma. Translocation t(1;6) was found as the primary karyotypic abnormality in three patients. Additional chromosomal aberrations included changes frequently found in unmutated B-CLL, that is, del(11)(q), trisomy 12 and 17p aberrations. Fluorescence in situ hybridization analysis performed in seven cases allowed us to map the t(1;6) breakpoints to the 1p35.3 and 6p25.2 chromosomal bands, respectively. The latter breakpoint was located in the genomic region coding for MUM1/IRF4, one of the key regulators of lymphocyte development and proliferation, suggesting involvement of this gene in the t(1;6). Molecular characterization of the t(1;6)(p35.3;p25.2), exclusively found in unmutated subtype of B-CLL, is in progress.

Maintenance of remission with human recombinant interferon alfa-2a in patients with stages III and IV low-grade malignant non-Hodgkin's lymphoma. European Organization for Research and Treatment of Cancer Lymphoma Cooperative Group.

PURPOSE: Interferon alfa has shown significant activity in patients with low-grade malignant non-Hodgkin's lymphoma (NHL). In 1985, we initiated a prospective randomized study in which the potential benefit of interferon alfa given as maintenance treatment was investigated after tumor load reduction was achieved with chemoradiotherapy in patients with advanced low-grade malignant non-Hodgkin's lymphoma. PATIENTS AND METHODS: The study involved 347 patients with stage III or IV disease, 315 satisfying the eligibility criteria. All were treated with a regimen of cyclophosphamide, vincristine, and prednisone (CVP) given every 3 weeks for eight cycles. Thereafter, patients were eligible for iceberg irradiation. Finally, all patients were completely restaged, and responding and stable-disease patients were then randomized, 122 to interferon alfa-2a maintenance, 3 million U three times weekly for 1 year; and 120 to no further treatment. RESULTS: Seventy-nine percent of the patients response to CVP, ie, 45% complete remissions (CR) and 34% partial remissions (PR). In the group of randomized patients, the response rate after CVP plus or minus radiotherapy was 90%. As compared with control patients, patients in the interferon (IFN) maintenance group had a tendency toward a prolonged time to progression (TTP) (median, 132 v 87 weeks; P = .054, adjusted for response to CVP). However, overall survival was similar in both groups. Interferon was well tolerated. The median dose of IFN actually received corresponded to 90% of the planned cumulative dose. The treatment had to be stopped because of toxicity in 16 patients (15% of the patients in whom IFN was started). CONCLUSION: Interferon maintenance treatment in the phase of minimal residual disease of patients with advanced low-grade malignant NHL increased TTP at the borderline of statistical significance, without remarkable toxicity. However, overall survival was not influenced.

Activity of oral fludarabine phosphate in previously treated chronic lymphocytic leukemia.

PURPOSE: A prospective, multicenter, open-label phase II clinical trial was conducted to assess the efficacy and safety of oral fludarabine phosphate. Reference to an historical group of patients treated with the intravenous (IV) formulation allowed the investigators to compare the two formulations. PATIENTS AND METHODS: Efficacy was assessed using the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) and National Cancer Institute (NCI) criteria for complete remission (CR), partial remission (PR), stable disease, or disease progression. Safety monitoring included World Health Organization (WHO) toxicity grading for all adverse events. RESULTS: Seventy-eight (96.3%) of 81 recruited patients with previously treated B-cell chronic lymphocytic leukemia (CLL) received 10-mg tablets of fludarabine phosphate to a dose of 40 mg/m(2)/d for 5 days, repeated every 4 weeks, for a total of six to eight cycles. According to IWCLL criteria, the overall remission rate was 46.2% (CR, 20.5%; PR, 25.6%). The comparative figures using NCI criteria were 51.3% (CR, 17.9%; PR, 33.3%). Overall, 30 incidents of severe adverse events were reported for 22 patients. WHO grade 3 or grade 4 hematologic toxicities included granulocytopenia (53.8%), leukocytopenia (28.2%), thrombocytopenia (25.6%), and anemia (24.4%). Gastrointestinal adverse events were more common with the oral formulation than previously reported with IV fludarabine phosphate. However, these events were generally mild to moderate. CONCLUSION: This study demonstrates that oral fludarabine phosphate has similar clinical efficacy to the IV formulation and a safety profile that is both predictable and essentially similar to that of the IV formulation.

Efficacy and safety of oral fludarabine phosphate in previously untreated patients with chronic lymphocytic leukemia.

PURPOSE: A prospective, multicenter, open-label, phase II clinical trial to assess oral fludarabine phosphate treatment in terms of safety, efficacy, and quality of life. Reference to a historical group of patients treated with the intravenous (IV) formulation allowed the two formulations to be compared. PATIENTS AND METHODS: Patients with previously untreated B-cell chronic lymphocytic leukemia received 10-mg tablets of fludarabine phosphate to a dose of 40 mg/m(2)/d for 5 days, repeated every 4 weeks, for a total of six to eight cycles. Efficacy was assessed using International Workshop on Chronic Lymphocytic Leukemia and National Cancer Institute criteria for response. Safety monitoring included WHO toxicity grading for adverse events. Quality of life was also assessed. RESULTS: Eighty-one patients received treatment. According to International Workshop on Chronic Lymphocytic Leukemia criteria, the overall response rate was 71.6% (complete remission, 37.0%; partial remission, 34.6%). The response rate using National Cancer Institute criteria was 80.2% (complete remission, 12.3%; partial remission, 67.9%). Median time to progression was 841 days (range, 28 to 1,146 days). The most frequently reported grade 3/4 toxicity was myelosuppression. WHO grade 3/4 hematological toxicities included granulocytopenia (32.1%), anemia (9.9%), and thrombocytopenia (4.9%). Gastrointestinal toxicity was more common with the oral formulation than with IV fludarabine phosphate, but was generally mild to moderate and did not require treatment. Statistically significant improvements in mean emotional and insomnia quality-of-life scores were seen after treatment. CONCLUSION: This study demonstrates that oral fludarabine phosphate is clinically effective and generally well tolerated by patients with previously untreated B-cell chronic lymphocytic leukemia. Oral fludarabine phosphate has a similar clinical efficacy and safety profile to the IV formulation. Oral fludarabine phosphate does not adversely affect quality of life and may improve emotional and insomnia scores.

Cytogenetic analysis of B cell chronic lymphoid leukemias classified according to morphologic and immunophenotypic (FAB) criteria.

609 patients with B cell chronic lymphoproliferative disorder were studied with the primary aim of analyzing the cytogenetic profile of B cell chronic lymphocytic leukemias and, if possible, define correlations with FAB classification of these diseases. Morphological and immunological studies were performed according to criteria proposed by the FAB group. A panel of monoclonal antibodies, including at least sIg, CD19, CD5, and FMC7 was used. Interpretations of morphology and cytogenetics were made independently. When applying strict FAB criteria 65% of the cases could be classified. Most of them (44%) were chronic lymphocytic leukemia (CLL). The cases not satisfying strict FAB criteria could be divided into two groups: one closely related to CLL, and here defined as atypical CLL (aCLL) (21%) and another group consisting of patients with leukemic manifestations of B cell non-Hodgkin's lymphoma (LL) (14%). Analyzable metaphases were obtained in 89% of patients. Clonal abnormalities were present in 35% of patients. The most frequent chromosomal changes were abnormalities of chromosome 11q (60 cases), trisomy 12 (46 cases) and structural rearrangements of chromosome 14q (44 cases). Statistical associations with FAB subtypes were found: aCLL and trisomy 12 (P < 0.00001); mantle zone lymphoma (MZL) and t(11;14) (P < 0.00001) and del(6)(q) (P < 0.0001); CLL/mixed cell type and del(6)(q) (P < 0.002); follicular lymphoma and t(14;18) (P < 0.00001); splenic lymphoma with villous lymphocytes and del(7)(q) (P < 0.0004); leukemic lymphoma (LL) with rearrangements in chromosome 9q (P < 0.0001) and trisomy of 3 (P < 0.001). Chronic lymphocytic leukemia was not statistically associated with any specific chromosomal abnormality. However, this subtype showed a high incidence of del(11)(q) and rearrangements of 13q. This study confirms the value of cytogenetic investigation in the diagnosis of these disorders and may provide some new elements for future refinement of the FAB classification in mature B cell lymphocytic disorders.

Clinical and molecular features of FIP1L1-PDFGRA (+) chronic eosinophilic leukemias.

Detection of the FIP1L1-PDGFRA fusion gene or the corresponding cryptic 4q12 deletion supports the diagnosis of chronic eosinophilic leukemia (CEL) in patients with chronic hypereosinophilia. We retrospectively characterized 17 patients fulfilling WHO criteria for idiopathic hypereosinophilic syndrome (IHES) or CEL, using nested RT-PCR and interphase fluorescence in situ hybridization (FISH). Eight had FIP1L1-PDGFRA (+) CEL, three had FIP1L1-PDGFRA (-) CEL and six had IHES. FIP1L1-PDGFRA (+) CEL responded poorly to steroids, hydroxyurea or interferon-alpha, and had a high probability of eosinophilic endomyocarditis (n=4) and disease-related death (n=4). In FIP1L1-PDGFRA (+) CEL, palpable splenomegaly was present in 5/8 cases, serum vitamin B(12) was always markedly increased, and marrow biopsies revealed a distinctively myeloproliferative aspect. Imatinib induced rapid complete hematological responses in 4/4 treated FIP1L1-PDGFRA (+) cases, including one female, and complete molecular remission in 2/3 evaluable cases. In the female patient, 1 log reduction of FIP1L1-PDGFRA copy number was reached as by real-time quantitative PCR (RQ-PCR). Thus, correlating IHES/CEL genotype with phenotype, FIP1L1-PDGFRA (+) CEL emerges as a homogeneous clinicobiological entity, where imatinib can induce molecular remission. While RT-PCR and interphase FISH are equally valid diagnostic tools, the role of marrow biopsy in diagnosis and of RQ-PCR in disease and therapy monitoring needs further evaluation.

Chemical and quantum mechanical studies of the free radical C-C bond formation in the lipoxygenase-catalyzed dimerisation of octodeca-9,12-diynoic acid.

Triple bond analogues of poly-unsaturated fatty acids are well-known inactivators of lipoxygenases. In an earlier study we proposed that, since 11-oxo-octadeca-9,12-diynoic acid (11-oxo-ODYA) is the only oxygenated product formed during the irreversible inactivation of soybean lipoxygenase-1, the inactivation should proceed via a C11 centered octadeca-9,12-diynoic acid radical (ODYA radical). In the present study we investigated the lipoxygenase-catalysed formation of the ODYA radical. In the reaction of lipoxygenase with ODYA in the absence of dioxygen and in the presence of 13(S)-hydroperoxy-octadeca-9Z, 11E-dienoic acid (13-HPOD), free ODYA radicals were formed which resulted in the formation of three dimeric ODYA products in which one ODYA moiety is linked via its C9 (12%), C11 (72%) or C13 (16%) to the C11 methylene of the other ODYA moiety. With the ab initio Hartree-Fock method, using the 2,5-heptadiynyl radical as a model compound, the electron spin in the ODYA radical was calculated to be located for 12.0, 75.0 and 12.0% on carbon atoms C9, C11 and C13 of the ODYA radical, respectively. The ODYA-ODYA dimer formation could thus be explained on the basis of the electron spin distribution in the ODYA radical. The dimer formation, i. e. reaction of an ODYA radical with an ODYA molecule was compared with the reaction of the ODYA radical with dioxygen. On the basis of this comparison it is concluded that a) the ODYA dimer formation occurs at the carbon atom with the highest electron spin population; b) ODYA dimer formation is predominantly a kinetically determined process; c) the electron spin distribution in the ODYA radical can be used to predict the composition of the dimer mixture; and d) the regiospecific oxygen addition in the formation of 11-oxo-ODYA is enzymatically controlled.

Bone marrow transplantation performed as first-time treatment in two cases of secondary acute myeloid leukemia.

Two young patients with secondary acute myeloid leukemia were treated with allogeneic bone marrow transplantation as first-line treatment for their disease. High dose cytosine arabinoside was added to the conventional preparative regiment of cyclophosphamide and total body irradiation. No major problems were encountered to the immediate post-transplantation period. Complete remission of the acute myeloid leukemia was noted in both patients, with no evidence of recurrent disease at 15+ and 13 months. One patient developed severe pancytopenia 10 months after grafting with the presence of antibodies against platelets and granulocytes from the bone marrow donor. She died 3 months later from a generalised Aspergillus septicemia, probably precipitated by therapy with high doses of methylprednisolone. The other patient is alive in excellent clinical condition and in hematologic remission. Bone marrow transplantation must be taken into consideration as first-line therapy in any young patient who is suffering from a refractory type of leukemia and who has a suitable donor.

Cutaneous mastocytosis after autologous bone marrow transplantation.

A 41-year-old male patient developed cutaneous mastocytosis 3 months after autologous bone marrow transplantation (ABMT). The ABMT was performed as part of consolidation treatment for a high-grade malignant non-Hodgkin's lymphoma. There was no evidence for systemic mastocytosis. Recurrence of the lymphoma could not be shown. Mast cell proliferation frequently coexists with dysplastic and neoplastic disorders of myeloid and, more rarely, of lymphoid cells. Mast cells are growth factor responsive and ultimately originate from the pluripotent hematopoietic stem cell. After autologous bone marrow transplantation, hematological reconstitution may in rare cases lead to an abnormal proliferation of mast cells possibly due to unbalanced production of growth factors.

Efficacy of autologous stem cell transplantation in mantle cell lymphoma: a 3-year follow-up study.

This study was designed to evaluate the efficacy of therapeutic intensification with autologous stem cell transplantation (ASCT) for mantle cell lymphomas (MCL) in terms of response rate, duration of response, and event-free and overall survivals. Twenty-four patients with confirmed MCL responding to chemotherapy received a high-dose chemo-radiotherapy regimen followed by ASCT. Transplantation was performed during first-line therapy in nine cases, second-line in 13 cases and third-line in two cases. The source of hematopoietic stem cells was peripheral blood for 19 cases. At the time of ASCT, eight patients were in complete remission (33%). Seventeen of the 24 cases received an intensified regimen with TBI and seven received the BEAM or the BEAC regimen. After transplantation, 19 patients were in CR (79%). Nine of these were alive in continued CR at a median follow-up of 34 months, while seven relapsed at a median of 18 months. One patient died from Pneumocystis carinii interstitial pneumonitis and five patients developed secondary malignancies. With a median follow-up after transplantation of 34 months, the 3-year event-free survival was 55% and the 3-year overall survival was 68%. These results indicate that therapeutic intensification with ASCT might be an effective treatment for mantle cell lymphomas. Bone Marrow Transplantation (2000) 25, 251-256.

Covalent and non-covalent dissociations of gas-phase complexes of avoparcin and bacterial receptor mimicking precursor peptides studied by collisionally activated decomposition mass spectrometry.

The gas-phase stability and reactivity of non-covalent complexes of avoparcin and bacterial receptor mimicking precursor peptides were probed by electrospray ionization mass spectrometry combined with collisionally activated decomposition (CAD) studies. The order of the gas-phase stabilities of these non-covalent complexes is different from the order of the stabilities of the same complexes in solution. The specific stereoselectivity observed in non-covalent binding in solution is not retained in the gas phase. The presence of a lysine residue in the bacterial receptor mimicking precursor peptides appears to promote the gas-phase stabilities of the antibiotic-peptide complexes. Complexes of avoparcin with receptor peptides containing a lysine residue are stabilized in the gas phase to such an extent that CAD of these non-covalent complexes proceeds through a competition between non-covalent and covalent fragmentation pathways. These results indicate clearly that the use of CAD mass spectra for the quantitative characterization of the stability of non-covalent complexes in solution should be applied with extreme caution.

Variant translocation t(15q;17q) accompanying a promyelocytic accelerated phase of Ph-positive chronic myeloid leukemia.

One case of Philadelphia-positive chronic myeloid leukemia showed a high promyelocytic component associated with a variant t(15q-,17q+) translocation. A key role for chromosome #17 in the promyelocytic proliferation and/or differentiation is emphasized.

Distribution of methyl substituents in amylose and amylopectin from methylated potato starches.

Granular potato starches were methylated in aqueous suspension with dimethyl sulfate to molar substitution (MS) values up to 0.29. Fractions containing mainly amylose or amylopectin were obtained after aqueous leaching of the derivatised starch granules. Amylopectin in these fractions was precipitated with Concanavalin A to separate it from amylose. Amylose remained in solution and was enzymatically converted into D-glucose for quantification, thereby taking into account the decreased digestibility due to the presence of methyl substituents. It was found that the MS of amylose was 1.6-1.9 times higher than that of amylopectin in methylated starch granules. The distributions of methyl substituents in trimers and tetramers, prepared from amylose- or amylopectin-enriched fractions, were determined by FAB mass spectrometry and compared with the outcome of a statistically random distribution. It turned out that substituents in amylopectin were distributed heterogeneously, whereas substitution of amylose was almost random. The results are rationalised on the basis of an organised framework that is built up from amylopectin side chains. The crystalline lamellae are less accessible for substitution than amorphous branching points and amylose.

FAB CIDMS/MS analysis of partially methylated maltotrioses derived from methylated amylose: a study of the substituent distribution.

Amylose was methylated with CH3I in alkaline aqueous suspension, yielding methylated amylose (MeAl) with a degree of substitution of 1.44 (s < 0.01). Determination of the monomer composition showed that HO-6 and HO-2 were highly substituted in contrast to HO-3 (7:2:5.5, HO-2:HO-3:HO-6). By using partial acid hydrolysis, oligomers were prepared that varied both in degree of polymerisation and in methyl-content. Studies on the distribution of substituents in trimers showed large deviations from random distributions. By using CID tandem mass spectrometry, the substituent distribution in these trimers was determined in more detail. Various sets of trimers with equal amounts of methyl-groups but differing in substituted positions were quantified. From the monomer composition of MeAl, the probability of each trimer was calculated and compared to the outcome of the measured distributions. It was concluded that trimers with terminal tri- or non-substituted glucose monomers at the non-reducing end were formed preferentially during partial hydrolysis and that partial hydrolysis of MeAl yielded oligomers in a non-random way. This is the first study that describes the partial hydrolysis of MeAl in such detail.

Screening for Ureaplasma urealyticum infections in the neonate and the association with prematurity.

Ureaplasma urealyticum has been implicated in gynaecological, obstetrical and neonatal pathology. Increased levels of C-reactive protein and total IgM concentrations in cord blood have often been used as a screening method for infectious disease in the fetus and the newborn. Analysis of the isolation rate of U. urealyticum in function of the concentrations of these two parameters in cord blood showed that U. urealyticum was significantly (P less than 0.05) more frequently isolated when CRP was above normal in cord blood. No correlation between the IgM level in the newborn and the presence of U. urealyticum could be established. A significant relationship was found (P less than 0.01) between Ureaplasma isolation in the urine of mother and child on the one hand and gestational age on the other hand, which supports the hypothesis that U. urealyticum may play a role in preterm delivery.