IntroductionGastric mucosa-associated lymphoid tissue (MALT) B-cell lymphoma develops in the context of long-term infection with the Gram-negative gastric bacterium Helicobacter pylori. 1-3 Persistent infection with H pylori causes chronic gastritis that, in some people, can develop into more organized gastric mucosa-associated lymphoid tissue (MALT) with histologic similarity to the Peyer patches of the small intestine. 4 The disease progresses when individual malignant clones grow out, displace the benign lymphoid tissue, and ultimately form the lymphoepithelial lesions that are a hallmark of MALT lymphoma. 5,6 In its early stages, gastric MALT lymphoma is believed to be an antigen-dependent disease; H pylori infection is detectable in a large majority of cases. 1,3,7 Eradication therapy induces tumor regression in approximately 75% of patients at this stage. 8,9 Early-stage low-grade MALT lymphoma is generally considered an indolent tumor due to its slow growth, low proliferation rates, and minimal propensity for spreading. At later stages, however, the tumors can eventually undergo high-grade transformation or acquire one of several known characteristic chromosomal translocations, thereby rendering the lymphoma independent of antigen exposure and refractory to H pylori eradication therapy.In contrast to cases with chromosomal rearrangements, which grow autonomously due to constitutive activation of the nuclear factor B (NF-B) signaling pathway brought about by overexpression of MALT-1, B-cell leukemia 10 (Bcl-10), or production of the Baculovirus IAP repeat-containing 3 (API2)-MALT1 fusion protein (reviewed in Isaacson and Du), 5 little is known about the pathogenesis of early MALT lymphoma. Several studies have implicated the abundant population of tumor-infiltrating T cells in providing growth signals to tumor B cells. [10][11][12] In one study, depletion of T cells was shown to abrogate the proliferation of explanted MALT lymphoma cultures. 12 We and others have reported that MALT lymphomas express high levels of interleukin-4 (IL-4) and other T helper 2 cytokines in vivo, supporting a role for T helper 2-polarized T-helper responses in early MALT lymphomagenesis. 10,11 An alternative possibility is that early stage MALT lymphoma B cells receive signals via antigenic stimulation through their B-cell receptor (BCR), which would lead to NF-B activation, survival, and proliferation. Indeed, MALT lymphoma cells carry functional, rearranged, and somatically mutated immunoglobulin genes on their surface. 13,14 Sequence analysis of the V H genes suggests that the tumor cells have undergone positive selection in germinal centers. [14][15][16] Intraclonal variation caused by ongoing somatic mutation and/or replacement of a part of the variable heavy segment (receptor revision) has been reported. [15][16][17] Despite these clear results, the search for a target antigen has proven difficult and has yielded controversial results, either providing evidence for reactivity toward certain structures of normal human tissu...

The performance of a diagnostic test is best evaluated against a reference test that is without error. For many diseases, this is not possible, and an imperfect reference test must be used. However, diagnostic accuracy estimates may be biased if inaccurately verified status is used as the truth. Statistical models have been developed to handle this situation by treating disease as a latent variable. In this paper, we conduct a systematized review of statistical methods using latent class models for estimating test accuracy and disease prevalence in the absence of complete verification.

Trust has been considered a central aspect of successful IT outsourcing. Although a great deal of interest in trust has been described, there are very few theoretical models in the IT outsourcing literature to explain mutual trust, its role, and its impact in IT outsourcing. This study proposes a trust-based relationship research model to assess the perceived IT outsourcing success in terms of (1) mutual trust with its temporal dimension of initial trust and initial distrust, and (2) knowledge sharing with the moderating effect of mutual dependency. This model was then validated and applied in a study involving organizations in Korea. The data was collected and analyzed to understand initial trust, initial distrust, knowledge sharing, and mutual dependency as contributing factors to success in IT outsourcing. The results show that mutual trust between the service receiver and provider is very important for knowledge sharing and outsourcing success, and is affected by the initial perception to each other's partner at the beginning of the outsourcing process. Interestingly, this study also shows that initial trust is considered a significant factor in the perception of mutual trust from the service receiver's perspective, but not from the service provider's viewpoint. The results help extend our understanding of critical success factors in outsourcing success and of different standpoints between the service receiver and provider.

Summary Haemato‐oncological patients are at risk in case of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection. Currently, vaccination is the best‐evaluated preventive strategy. In the present study, we aimed to assess serological response, predictive markers, and safety of BNT162b2 in haemato‐oncological patients. A total of 259 haemato‐oncological patients were vaccinated with two 30 µg doses of BNT162b2 administered 21 days apart. Serological response was assessed by ELECSYS® Anti‐SARS‐CoV‐2‐S immunoassay before vaccination, and at 3 and 7 weeks after the first dose (T1, T2). Safety assessment was performed. At T2 spike protein receptor binding domain (S/RBD) antibodies were detected in 71·4% of haematological and in 94·5% of oncological patients (P < 0·001). Haematological patients receiving systemic treatment had a 14·2‐fold increased risk of non‐responding (95% confidence interval 3·2–63·3, P = 0·001). Subgroups of patients with lymphoma or chronic lymphocytic leukaemia were at highest risk of serological non‐response. Low immunoglobulin G (IgG) level, lymphocyte‐ and natural killer (NK)‐cell counts were significantly associated with poor serological response (P < 0·05). Vaccination was well tolerated with only 2·7% of patients reporting severe side‐effects. Patients with side‐effects developed a higher S/RBD‐antibody titre compared to patients without side‐effects (P = 0·038). Haematological patients under treatment were at highest risk of serological non‐response. Low lymphocytes, NK cells and IgG levels were found to be associated with serological non‐response. Serological response in oncological patients was encouraging. The use of BNT162b2 is safe in haemato‐oncological patients.

Experts and business pundits forecasted drastic changes in Vietnam’s fledgling e-commerce when the Southeast Asian country became an official member of the World Trade Organization (WTO) in 2007. Over the past few years, as part of the Reform – called Doi moi – some Vietnamese enterprises have adopted e-commerce and already benefitted from it. In this research, the authors adapt the Technology-Organization-Environment (TOE) framework and test a model of e-commerce adoption including numerous internal and external factors identified in empirical studies. The final sample of 926 small and medium-sized enterprises in Vietnam includes both adopter and non-adopter firms. The policy implications of this study on promoting e-commerce adoption by SMEs in transition economies, such as Vietnam, are discussed.