Dose-response effects of methylphenidate on ecologically valid measures of academic performance and classroom behavior in adolescents with ADHD.

The effects of methylphenidate on the academic performance and classroom behavior of 45 adolescents with attention deficit hyperactivity disorder were studied. During a 6-week, placebo-controlled medication assessment in the context of a summer treatment program, participants received a double-blind, crossover trial of 3 doses of methylphenidate. Dependent measures included note-taking quality, quiz and worksheet scores, written language usage and productivity, teacher ratings, on-task and disruptive behavior, and homework completion.

Regulation of BOB.1/OBF.1 stability by SIAH.

The BOB.1/OBF.1 coactivator is critically involved in mediating octamer-dependent transcriptional activity in B lymphocytes.

Loss of Fas (CD95/APO-1) regulatory function is an important step in early MALT-type lymphoma development.

Fas (CD95, APO-1) mutations were found in autoimmune diseases and some lymphomas, suggesting impairment of Fas-mediated cell death signaling that may cause tumor development. Because mucosa-associated lymphoid tissue (MALT)-type lymphoma B cells recognize autoantigens and proliferate in response to antigen and T cell-mediated signals, it is suggestive that autoreactive B cell lymphoma precursor cells may have escaped the Fas-mediated checkpoint that normally operates in healthy individuals. Using different biochemical, molecular, and functional approaches, we analyzed the Fas signaling in malignant B cells from seven MALT-type lymphomas that were additionally characterized for the t(11;18)(q21;q21) and four gastric diffuse large B cell lymphomas (DLBL).

Complete remission of primary high-grade B-cell gastric lymphoma after cure of Helicobacter pylori infection.

Purpose: Treatment of low-grade gastric mucosa-associated lymphoid tissue lymphoma by eradication of Helicobacter pylori is reported to result in complete lymphoma remission in approximately 75% of cases. The effect that cure of the infection has on the course of a primary high-grade gastric lymphoma is largely uncertain. The aim of this study was to report the effect of cure of H pylori infection exerted in patients with high-grade B-cell gastric lymphoma.

[Impaired CD95-(Fas,APO-1-)apoptosis regulation is a progression factor in early MALT-type lymphoma genesis].

Background: MALT-type lymphomas are B cell tumors arising for so far unknown reasons on the background of chronic inflammation, e.g. Helicobacter pylori-associated gastritis.

Mucosal humoral immune response to CagA shows a high prevalence in patients with gastric MALT-type lymphoma.

In the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT)-type lymphoma, CagA-positive Helicobacter pylori strains have been suspected of making a significant contribution. To investigate this hypothesis in more detail, the mucosal humoral immune response of 15 patients with gastric MALT-type lymphoma was examined in the tumor and in the tumor-free gastritis of the same patient. Mononuclear cells from different sites (antrum, corpus, lymphoma) were cultured.

Behavioral versus behavioral and pharmacological treatment in ADHD children attending a summer treatment program.

As part of the behavioral treatment in the Multimodal Treatment Study of Children with ADHD (MTA9), children participated in an intensive summer treatment program (STP). This study examined the differences between 57 children in the combined treatment (Comb) group, who were medicated, and 60 children in the behavioral treatment (Beh) group, who were unmedicated throughout the STP. Comb children were significantly better than Beh on 5 measures: rule following, good sportsmanship, peer negative nominations, and STP teacher posttreatment ratings of inattention/overactivity.

Characterization of Wue-1, a novel monoclonal antibody that stimulates the growth of plasmacytoma cell lines.

A new monoclonal antibody, Wue-1, which specifically recognizes normal and malignant plasma cells, is characterized. Biochemical studies showed that monoclonal antibodies (mAbs) recognize a protein of 94 kDa. Using triple-staining flow cytometry and double-labeling immunohistochemical techniques, two populations of plasma cells, i.

Heterogeneity of the API2-MALT1 gene rearrangement in MALT-type lymphoma.

The translocation t(11;18)(q21;q21), which is the most frequent chromosomal aberration in extranodal marginal zone B cell lymphomas of MALT-type, was characterised in a series of 34 biopsies, including 18 gastric non-Hodgkin's lymphomas (NHL) of MALT-type, six MALT-type NHL of extragastral origin and 10 extranodal large B cell lymphomas (LBL). Based on fluorescence in situ hybridisation, STS-PCR analysis and screening of genomic PAC libraries, a physical map of contiguous DNA probes on chromosome 11 was constructed containing the anti-apoptotic genes API2 and API1 adjacent to the translocation breakpoint. RACE-PCR experiments revealed MALT1 the chromosome 18-derived fusion partner of API2, which has also been reported recently by other groups.

Primary gastric B-cell lymphoma: results of a prospective multicenter study. The German-Austrian Gastrointestinal Lymphoma Study Group.

Background & Aims: Appropriate management of primary gastric lymphoma is controversial. This prospective, multicenter study aimed to evaluate the accuracy of endoscopic biopsy diagnosis and clinical staging procedures and assess a treatment strategy based on Helicobacter pylori status and tumor stage and grade.

Methods: Of 266 patients with primary gastric B-cell lymphoma, 236 with stages EI (n = 151) or EII (n = 85) were included in an intention-to-treat analysis.

The role of microsatellite instability in gastric low- and high-grade lymphoma development.

DNA mismatch repair genes and their dysfunction as evidenced by microsatellite instability (MSI) play an important role in the pathogenesis of a variety of tumors, most prominently hereditary nonpolyposis colorectal cancer (HNPCC). However, their role in development of extranodal lymphomas has not been established yet. We therefore evaluated for MSI 25 gastric low-grade marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue type and 31 gastric high-grade diffuse large B-cell lymphomas (DLBCLs) with 29 and 118 microsatellites, respectively.

Marginal zone B-cell lymphomas (MZBL) arising at different sites represent different biological entities.

Most entities of B-cell malignant non-Hodgkin's lymphomas (NHL) are characterized by typical primary chromosomal changes such as the t(14;18) in follicular lymphoma or the t(11;14) in mantle cell lymphoma. In contrast, marginal zone B-cell lymphomas (MZBL), arising at different nodal and extranodal sites, are poorly characterized on the genetic level. We performed cytogenetic investigations in 20 splenic and in 10 nodal MZBL and analyzed 52 MZBL (including 12 MALT-type lymphomas) for deletions of TP53, D13S25, and RB1 loci by fluorescence in situ hybridization.

Tumor biology of mucosa-associated lymphoid tissue lymphomas.

Extranodal lymphomas arising at mucosal sites exhibit clinicopathological features that suggest a closer relationship of these tumors to the structure and function of mucosa-associated lymphoid tissue (MALT) than to lymph nodes. The factors that induce MALT in these tissues are operative in early MALT lymphoma development and the progressive independence on T-cell help defines late stages of MALT lymphoma genesis.

Helicobacter pylori in gastric mucosa-associated lymphoid tissue type lymphoma.

Infection with Helicobacter pylori triggers the acquisition of gastric mucosa-associated lymphoid tissue (MALT) and provides the background for MALT-type lymphoma development. This concept has been supported by a high association of H. pylori infection and MALT-type lymphoma and by the regression of most lymphomas after eradication therapy.

Genetic imbalances in primary gastric diffuse large B-cell lymphomas: comparison of comparative genomic hybridization, microsatellite, and cytogenetic analysis.

Extranodal malignant non-Hodgkin's lymphomas account for about 40% of lymphoid neoplasms, but few data are available concerning the genetic background of primary gastric diffuse large B-cell lymphoma (DLBCL). A study was performed of 27 primary gastric DLBCLs and 5 gastric DLBCLs with a concomitant low grade component of mucosa-associated lymphoid tissue-type lymphoma using comparative genomic hybridization (CGH), microsatellite studies, classic cytogenetics, and fluorescence in situ hybridization (FISH) to search for specific genetic aberrations. The most frequent aberrations were losses of material on chromosome 6q and gains of parts of chromosome 3.

[MALT-type B-cell lymphomas escape fas-mediated apoptosis].

Important prognostic factors in primary MALT-lymphomas are stage and grading since the localized low-grade lymphoma may be cured with antibiotic treatment that may result in lymphoma regression as exemplified in Helicobacter eradication (H.p.) in gastric low-grade MALT-lymphomas.

[MALT-type non-Hodgkin's lymphoma: advances in biopsy diagnosis and pathogenesis].

Malignant Non-Hodgkin's lymphomas of the mucosa-associated lymphoid tissue display unique morphological and biological features. Unlike the situation in nodal lymphomas, they almost invariably arise from defined and recognisable precursor lesions, such as chronic infections or autoimmune diseases. From the diagnostic point of view, efforts have been undertaken to define (1) the minimal requirements for the unequivocal diagnosis of MALT-type lymphoma, (2) the regression stages after Helicobacter pylori eradication, and (3) to establish a grading system for the respective lesions.

Up-regulation of BOB.1/OBF.1 expression in normal germinal center B cells and germinal center-derived lymphomas.

The BOB.1/OBF.1/OCAB.

Genetic aberrations common in gastric high-grade large B-cell lymphoma.

Genetic aberrations associated with the development of extranodal high-grade large B-cell lymphoma originating in the stomach have not been fully identified yet. We analyzed 31 such lymphomas using 73 microsatellite markers for allelic imbalance and microsatellite instability. The highest frequency (42%) of loss of heterozygosity (LOH) was found on the long arm of chromosome 6.

Interleukin-4 mediates STAT6 activation in 3T3-L1 preadipocytes but not adipocytes.

STAT6 is abundantly expressed in 3T3-L1 preadipocytes and adipocytes but activating ligands are not well defined. In this report, we provide evidence that interleukin 4 (IL-4) induced JAK2-mediated STAT6 tyrosine phosphorylation and DNA binding in 3T3-L1 preadipocytes but not in 3T3-L1 adipocytes. Loss of IL-4-mediated STAT6 tyrosine phosphorylation occurred 2 days after preadipocytes were induced to differentiate into adipocytes but when cells remained phenotypically preadipocytes.

Evaluation of Helicobacter pylori in gastric MALT-type lymphoma: differences between histologic and serologic diagnosis.

Helicobacter pylori provides the pathogenic background for the development of gastric MALT-type lymphoma. The assessment of H. pylori is limited by the accuracy of the detection method used.

Expression of costimulatory molecules in low-grade mucosa-associated lymphoid tissue-type lymphomas in vivo.

B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) type develop against a background of chronic inflammation and have functional autoantigen receptors. Because they respond to environmental factors in vivo, the expression of costimulatory molecules, which play a key role in the differentiation of normal B-lymphocytes and in T-/B-cell interaction, may be critical in early MALT-type lymphoma pathogenesis until further chromosomal aberration leads to progression. We found a high number of tumor-infiltrating T-lymphocytes (TITLs) in all low-grade MALT-type lymphomas.

Exclusive detection of the t(11;18)(q21;q21) in extranodal marginal zone B cell lymphomas (MZBL) of MALT type in contrast to other MZBL and extranodal large B cell lymphomas.

Extranodal mucosa-associated lymphoid tissue (MALT)-type lymphomas and nodal and splenic marginal zone B cell lymphomas (MZBL) share morphological and immunophenotypic features with marginal zone B cells of reactive lymphoid tissues. Although displaying a similar immunophenotype, recent investigations suggest fundamental genetic differences among these subgroups. To determine the prevalence of the t(11;18) in a larger series of MALT-type lymphomas and to investigate a possible occurrence in other lymphomas, we screened 106 non-Hodgkin's lymphomas (NHL) by interphase cytogenetics using yeast artificial chromosome (YAC) probes flanking the breakpoint at 11q21.

Oligoclonal expansions of T-cell repertoire in gastric mucosa associated lymphoid tissue type B-cell lymphoma and adjacent gastritis.

Local stimulation by Helicobacter pylori (HP), autoantigen, and a concurrent T-cell-mediated stimulation of B cells are believed to play an important role in gastric mucosa-associated lymphoid tissue (MALT) type B cell lymphomagenesis. Many autoimmune diseases have shown to lead to a skewed T-cell repertoire with autoantigen specific expansions and deletions. Characterization of lymphoma and gastritis areas of seven gastrectomy specimens using a T-cell receptor beta variable chain (TCR betaV) family-specific reverse transcriptase (RT)-polymerase chain reaction (PCR) assay and fluorescence-activated cell sorter (FACS) analysis revealed a local chronic and acute activation of T cells in lymphoma and an oligoclonal T-cell repertoire in gastritis and in lymphoma, partially sharing the same clones.