Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MALT”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMed2001

Loss of expression of alpha4beta7 integrin and L-selectin is associated with high-grade progression of low-grade MALT lymphoma.

Expression of adhesion molecule in low-grade B-cell mucosa-associated lymphoid tissue (MALT) lymphoma of the gastrointestinal tract has been reported in recent years, but these reports have primarily focused on low-grade gastrointestinal MALT lymphoma. In this study, we examined the lymphocytic homing receptor alpha4beta7 integrin, L-selectin, and VLA-4 and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in low-grade lymphoma of the gastrointestinal tract and other organs such as the ocular adnexa and thyroid. We also observed changes in the expression pattern associated with high-grade transformation. Neoplastic cells in the gastrointestinal low-grade lymphoma and the low-grade component of high-grade MALT lymphoma were found to be alpha4beta7 integrin(+), L-selectin(+), whereas the gastrointestinal high-grade component and diffuse large B-cell lymphoma were found to be alpha4beta7 integrin(-), L-selectin(-). High endothelial venules in the gastric MALT lymphomas expressed MAdCAM-1. In the ocular adnexa low-grade MALT lymphoma, most cases were alpha4beta7 integrin(-), L-selectin(+); and in the thyroid, most cases of both low- and high-grade MALT lymphoma were alpha4beta7 integrin(-), L-selectin(-). These findings show that alpha4beta7 integrin and L-selectin may play an important role in the lymphocyte homing of gastrointestinal low-grade MALT lymphoma and in the loss of alpha4beta7 integrin expression throughout the course of high-grade progression.

Cell Adhesion Molecules↗
PubMed1998

The ATP-binding cassette subunit of the maltose transporter MalK antagonizes MalT, the activator of the Escherichia coli mal regulon.

Transcription of the mal regulon of Escherichia coli K-12 is regulated by the positive activator, MalT. In the presence of ATP and maltotriose, MalT binds to decanucleotide MalT boxes that are found upstream of mal promoters and activates transcription at these sites. The earliest studies of the mal regulon, however, suggested a negative role for the MalK protein, the ATP-binding cassette subunit of the maltose transporter, in regulating mal gene expression. More recently, it was found that overexpression of the MalK protein resulted in very low levels of mal gene transcription. In this report we describe the use of tagged versions of MalT to provide evidence that it physically interacts with the MalK protein both in vitro and in vivo. In addition, we show that a novel malK mutation, malK941, results in an increased ability of MalK to down-modulate MalT activity in vivo. The fact that the MalK941 protein binds but does not hydrolyse ATP suggests that the MalK941 mutant protein mimics the inactive, ATP-bound form of the normal MalK protein. In contrast, cells with high levels of MalK ATPase show a reduced ability to down-modulate MalT and express several mal genes constitutively. These results are consistent with a model in which the inactive form of MalK down-modulates MalT and decreases transcription, whereas the active form of MalK does not. This model suggests that bacteria may be able to couple information about extracellular substrate availability to the transcriptional apparatus via the levels of ATP hydrolysis associated with transport.

ATP-Binding Cassette Transporters↗
PubMed2002

The Aes protein directly controls the activity of MalT, the central transcriptional activator of the Escherichia coli maltose regulon.

MalT, the transcriptional activator of the maltose regulon from Escherichia coli, is the prototype of a new family of transcription factors. Its activity is controlled by multiple regulatory signals. ATP and maltotriose (the inducer) are two effectors of the activator that positively control its multimerization, a critical step in promoter binding. In addition, MalK, the ABC component of the maltodextrin transport system, and the two enzymes MalY and Aes down-regulate MalT activity in vivo. By using a biochemical approach, we demonstrate here that (i) Aes controls MalT activity through direct protein-protein interaction, (ii) Aes competes with maltotriose for MalT binding, (iii) ATP and ADP differentially affect the competition between Aes and the inducer, and (iv) part, if not all, of the Aes binding site is located in DT1, the N-terminal domain of the activator, which also contains the ATP binding site. All of these characteristics point toward an identical mode of action for MalY and Aes. However, we have identified an amino acid substitution in MalT that suppresses MalT inhibition by Aes without interfering with its inhibition by MalY, suggesting that the binding sites of the two inhibitory proteins do not coincide. The differential effects of ATP and ADP on the competition between the inducer and Aes (or MalY) suggest that the ATPase activity displayed by MalT plays a role in the negative control of its activity.

Acetylesterase↗
PubMed2003

Supplements of transgenic malt or grain containing (1,3-1,4)-beta-glucanase increase the nutritive value of barley-based broiler diets to that of maize.

1. A diet with addition to normal barley of malt from transgenic barley expressing a protein engineered, thermotolerant Bacillus (1,3-1,4)-beta-glucanase during germination has previously been demonstrated to provide a broiler chicken weight gain comparable to maize diets. It also reduced dramatically the number of birds with adhering sticky droppings, but did not entirely eliminate sticky droppings. One of the objectives of the broiler chicken trials reported here was to determine if higher concentrations of transgenic malt could alleviate the sticky droppings. 2. Another aim was to investigate the feasibility of using mature transgenic grain containing the thermotolerant (1,3-1,4)-beta-glucanase as feed addition and to compare diets containing transgenic grain to a diet with the recommended amount of a commercial beta-glucanase-based product. 3. Inclusion of 75 or 151 g/kg transgenic malt containing 4.7 or 98 mg/kg thermotolerant (1,3-1,4)-beta-glucanase with 545 or 469 g/kg non-transgenic barley instead of maize yielded a weight gain in Cornish Cross broiler chickens indistinguishable from presently used maize diets. The gene encoding the enzyme is expressed in the aleurone with a barley alpha-amylase gene promoter and the enzyme is synthesised with a signal peptide for secretion into the endosperm of the malting grain. 4. Equal weight gain was achieved, when the feed included 39 g/kg transgenic barley grain [containing 66 mg/kg thermotolerant (1,3-1,4)-beta-glucanase] and 581 g/kg non-transgenic barley instead of maize. In this case, the gene encoding the enzyme has been expressed with the D-hordein gene (Hor3-1) promoter during grain maturation. The enzyme is synthesised as a precursor with a signal peptide for transport through the endoplasmic reticulum and targeted into the storage vacuoles. Deposition of the enzyme in the prolamin storage protein bodies of the endosperm protects it from degradation during the programmed cell death of the endosperm in the final stages of grain maturation and provides extraordinary heat stability. The large amount of highly active (1,3-1,4)-beta-glucanase in the mature grain allowed the reduction of the transgenic grain ingredient to 0.2 g/kg diet, thus making the ingredient comparable to that of the trace minerals added to standard diets. 5. A direct comparison using transgenic grain supplement at the level of 1 g/kg of feed with the standard recommended addition of the commercial enzyme preparation Avizyme 1100 at 1 g/kg yielded equal weight gain, feed consumption and feed efficiency in birds fed a barley-based diet. 6. The production of sticky droppings characteristic of broilers fed on barley diets was avoided with all 9 experimental diets and reduced to the level observed with a standard maize diet by supplementation with transgenic barley. 7. The excellent growth and normal survival of the 400 broilers tested on barley diets supplemented with transgenic grain or malt showed the grain and malt not to be toxic. 8. The barley feed with added transgenic grain or malt containing thermotolerant (1,3-1,4)-beta-glucanase provides an environmentally friendly alternative to enzyme additives, as it uses photosynthetic energy for production of the enzyme in the grain and thus avoids use of non-renewable energy for fermentation. The deposition of the enzyme in the protein bodies of the grain in the field makes coating procedures for stabilisation of enzyme activity superfluous. 9. Barley feed with the small amount of transgenic grain as additive to normal barley provides an alternative for broiler feed in areas where grain maize cannot be grown for climatic reasons or because of unsuitable soil and thus has to be imported.

Animal Feed↗
PubMed2001

CD4+ Th1-cells predominate in low-grade B-cell lymphoma of gastric mucosa-associated lymphoid tissue (MALT type).

BACKGROUND: Little is known about the function of T cells in the inflammatory infiltrate in Helicobacter pylori-associated gastritis and B-cell lymphoma of mucosa-associated lymphoid tissue (MALT type). Previous studies have proposed a dominant Th1-type response in low-grade MALT lymphoma consistent with the Th1 response observed in H. pylori-associated gastritis. METHODS: We performed a novel flow cytometric approach in which CD3 panning for enrichment and activation of small numbers of T cells and intracellular cytokine analysis were combined to selectively characterize the cytokine profile of T cells (IFN-gamma for Th1) derived from the gastric mucosa of 23 patients with low-grade MALT lymphoma stage IEI1 (lymphoma infiltration of mucosa/submucosa sparing the muscularis). Endosonography was performed in each case to control the depth of lymphoma infiltration. For comparison, 19 patients with H. pylori-positive gastritis were also analysed. RESULTS: There was a CD4/CD8 ratio of 4 in patients with MALT lymphoma and of 2 in chronic gastritis. The proportion of IFN-gamma producing cells within the CD4-positive T-cell population in MALT lymphoma was 22%; in chronic gastritis it was 13% while no such difference could be encountered in CD8-positive T cells. CONCLUSIONS: The data point towards a dominant intratumoral IFN-gamma dominated T-cell response associated with early low-grade MALT lymphoma. A polarized IFN-gamma dominated Th1-type response may either contribute to the inability of the immune system to eradicate H. pylori infection, thereby promoting the activation status of the lymphocytic infiltrate in low-grade MALT lymphoma, or may mirror a concomitant tumor-specific T-cell response accompanying early stages of tumor progression.

Adult↗
PubMed2003

Molecular pathogenesis of mucosal-associated lymphoid tissue (MALT) lymphoma.

Extranodal marginal zone B-cell lymphomas of mucosal-associated lymphoid tissue (MALT)-type occur in a number of anatomic sites, but share overlapping morphological and immunophenotypic features. Helicobacter pylori infection has been identified as an etiological factor in gastric MALT lymphoma, but the cause of MALT lymphomas at other sites remains a matter of speculation. Despite these limitations in understanding the etiology of MALT lymphoma, standard cytogenetic analysis has proved useful by demonstrating similar alterations in MALT lymphomas from different anatomic sites. The common cytogenetic alterations that characterize MALT lymphomas include t(11:18)(q21:q21), t(1;14)(p22;q32) and, more recently, t(14;18)(q32;q21). The apparent complexity of the cytogenetic alterations that have now been implicated in the pathogenesis of extranodal MALT lymphoma serves as a paradigm for molecular cross talk in neoplastic disease. Recent data have shown that these very disparate translocations affect a common signaling mechanism, and thus unify all three under a common pathogenesis, resulting in the constitutive activation of the NF-kappaB pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Treatment of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) with mitoxantrone, chlorambucil and prednisone (MCP).

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively common type of lymphoma arising in various tissues throughout the human body. Currently, there is no standard chemotherapy for advanced stage MALT lymphoma. This has prompted us to retrospectively analyse our experience with the MCP regimen (mitoxantrone, chlorambucil and prednisone) in patients with MALT lymphoma. PATIENTS AND METHODS: Patients with histologically verified MALT lymphoma undergoing chemotherapy with MCP were evaluated retrospectively. The MCP regimen consists of mitoxantrone 8 mg/m(2) intravenously on days 1 and 2, chlorambucil 3 x 3 mg/m(2) per os (p.o.) on days 1-5 and prednisone 25 mg/m(2) p.o. on days 1-5. Information analysed included localisation of the lymphoma, clinical stage, pretreatment, number of chemotherapy cycles administered, toxicity, response to treatment, follow-up time, relapse and survival. RESULTS: A total of 15 patients (six females and nine males aged between 34 and 88 years) with histologically ascertained MALT lymphoma undergoing treatment with the MCP regimen were identified from our records. Ten patients had extragastric lymphoma, while five patients suffered from gastric MALT lymphoma. All patients were chemotherapy-naïve, while two had been locally irradiated before application of MCP for recurrent disease. A total of 74 cycles was administered to our patients, with a median number of five cycles per patient. Eight (53%) patients achieved complete remission, six (40%) patients partial response and only one (7%) patient had progressive disease. Subjective tolerance was excellent, and toxicities were mainly haematological, including granulocytopenia World Health Organisation grade 3 and 4 in three patients each. In two patients, this was accompanied by single episodes of uncomplicated herpes simplex infection. At the time of analysis, all patients are still alive. No relapses have occurred after a median follow-up time of 16 (range 12-29) months. CONCLUSIONS: Our data suggest that MCP is an effective and well-tolerated regimen for treatment of patients with MALT lymphoma irrespective of localisation. Judging from our data, MCP also appears to be a feasible regimen in elderly patients.

Administration, Oral↗
PubMed2007

Cytogenetic abnormalities in MALT lymphomas and their precursor lesions from different organs. A fluorescence in situ hybridization (FISH) study.

AIMS: To analyse the possible activation of distinct molecular pathways in mucosa-associated lymphoid tissue (MALT) lymphoma, we determined the prevalence of trisomies 3, 12, 18 in MALT lymphomas from different organs, as well as the prevalence of translocations of the MALT1 gene in a subset of primary breast MALT lymphomas. We compared the numerical cytogenetic alterations in lymphomas, precursor lesions and in normal non-haematolymphoid tissue from the same organs. METHODS AND RESULTS: Forty-two samples of paraffin-embedded tissue (29 MALT lymphomas from stomach, breast, parotid and thyroid; two Sjögren's syndrome; two Hashimoto's thyroiditis and nine reactive samples) were studied by fluorescence in situ hybridization (FISH). Analysed together, the cases of gastric, parotid and thyroid MALT lymphomas presented trisomy 3 in 46%, trisomy 12 in 28% and trisomy 18 in 21% of the cases. In contrast to other locations, trisomy 3 was not present in the majority of the cases of primary breast MALT lymphomas. None of the nine breast cases presented MALT1 gene rearrangements. Half of the cases of preneoplastic lesions exhibited trisomy 3 and trisomy 12; none exhibited trisomy 18. CONCLUSIONS: Trisomy 3 is the most frequent numerical abnormality in gastric, parotid and thyroid but not in primary breast MALT lymphomas. MALT1 gene rearrangements are also rare in this location, suggesting that distinct molecular pathways may be activated in breast cases.

Chromosome Aberrations↗
PubMed2006

Rapid development of diffuse large B-Cell lymphoma after successful eradication of Helicobacter pylori for gastric MALT lymphoma.

Primary low-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach has a potential to transform to high-grade diffuse large B-cell lymphoma (DLBCL). However, the clonal relation between MALT lymphoma and de novo DLBCL is still controversial. We report here three patients with Helicobacter pylori (H. pylori)-positive gastric MALT lymphoma rapidly progressing to DLBCL at the same site after successful eradication of H. pylori. Although MALT lymphomas in our cases did not possess t(11; 18)(q21;q21), sequence analysis of the rearranged immunoglobulin heavy chain gene showed no clonal relation between preceding MALT lymphoma cells and de novo DLBCL cells at the same site. These findings question the scenario of direct clonal progression of low-grade MALT lymphomas without t(11; 18)(q21;q21) to DLBCL and serve as a reminder of the risk of the progression of DLBCL with a distinct clonality immediately after H. pylori eradication for low-grade MALT lymphoma.

Adult↗
PubMed2001

Predictive value of endoscopic ultrasonography for regression of gastric low grade and high grade MALT lymphomas after eradication of Helicobacter pylori.

BACKGROUND: While a close association between gastric mucosa associated lymphoid tissue (MALT) lymphoma and Helicobacter pylori infection has been established, there are still cases which do not respond to H pylori eradication. AIMS: To investigate the clinicopathological factors which may help predict the therapeutic efficacy of H pylori eradication in gastric MALT lymphoma. PATIENTS: Forty one patients with gastric MALT lymphoma, including low and high grade lesions. METHODS: After endosonographic staging was determined, H pylori was eradicated in all patients, and the subsequent gastric pathological course was then investigated. RESULTS: Complete regression of MALT lymphoma was observed in 29(71%) patients, partial regression in five (12%), and no regression in seven (17%). Twenty six (93%) of 28 MALT lymphomas restricted to the mucosa but only three (23%) of 13 lymphomas which invaded the deep portion of the submucosa or beyond completely regressed. Kaplan-Meier analysis for the probability of complete regression of MALT lymphoma revealed a significant difference between tumours restricted to the mucosa and those invading the submucosa deeply or beyond (p<0.05). Neither the presence of a high grade component, perigastric lymphadenopathy, nor clinical staging prior to eradication correlated with the probability of lymphoma regression. CONCLUSIONS: Assessment of deep submucosal invasion by endosonography is valuable for predicting the efficacy of H pylori eradication in gastric MALT lymphoma.

Adult↗
PubMed2001

Regression of gastric high grade mucosa associated lymphoid tissue (MALT) lymphoma after Helicobacter pylori eradication.

BACKGROUND: Most low grade gastric lymphomas arising from the mucosa associated lymphoid tissue (MALT) are related to Helicobacter pylori colonisation. Cases with disease limited to the stomach can be cured after H pylori eradication and remain in remission for years. In contrast, high grade lymphomas of the stomach, although also related to H pylori, do not usually respond to eradication treatment. CASE REPORT: A 36 year old patient was referred from another hospital with a diagnosis of a low grade gastric MALT lymphoma associated with H pylori. The patient was in stage I and while waiting for the biopsies to be reviewed H pylori eradication therapy was given as the first step of treatment. Review of the biopsies showed a high grade immunoblastic lymphoma with areas of low grade gastric MALT lymphoma (high grade gastric MALT lymphoma or diffuse large B cell lymphoma with areas of MALT type lymphoma of the WHO classification). The patient received no further treatment but has been closely followed up for 32 months with sequential endoscopies to obtain biopsies for histological studies, H pylori cultures, and polymerase chain reaction analysis of the IgH gene. RESULTS: After H pylori eradication the patient had a complete histological response that has been maintained for 32 months. Monoclonal IgH gene rearrangement persisted for 32 months. CONCLUSION: The response of this patient indicates the possibility that some cases of high grade gastric MALT lymphoma (possibly patients in stage I with a superficial or limited disease) may still be responsive to H pylori antigenic drive and may be cured with eradication therapy. Prospective studies should be performed to identify patients with high grade gastric MALT lymphomas that may respond to eradication therapy and be spared of other more aggressive treatments.

Adult↗
PubMed2002

The natural history of a gastric low grade B cell MALT lymphoma followed during 11 years without treatment.

Low grade B cell mucosa associated lymphoid tissue (MALT) lymphoma of the stomach is usually an indolent tumour that remains localised for a long time before dissemination occurs. MALT appears in the stomach in response to infection by Helicobacter pylori, which is present in 80-90% of cases. The pathogenesis of the evolution from chronic gastritis to malignant lymphoma has not yet been fully explained and the exact role of H pylori in the pathogenesis and progression of gastric lymphoma remains unclear. This report describes the case of a 72 year old woman with a low grade B cell MALT lymphoma localised in the gastric fundus, who refused to be treated for eradication of H pylori. The histological diagnosis of B cell MALT lymphoma was supported by both immunohistochemical and molecular genetic analysis. After 11 years of follow up, this MALT lymphoma remained indolent, without local progression or blastic transformation, and the H pylori infection was still persistent, even though the density of bacteria had decreased drastically. Interestingly, two different clonal immunoglobulin (Ig) gene rearrangements were found in two series of biopsies performed with an interval of 11 years. This case report supports the following notions: (1) H pylori associated gastritis is a risk factor for gastric MALT lymphoma, but might not be sufficient by itself for the progression of the disease, and (2) in the evolution of MALT lymphomas, different cell clones characterised by different Ig rearrangements may emerge.

Aged↗
PubMed2004

Translocation t(11;18)(q21;q21) is not predictive of response to chemotherapy with 2CdA in patients with gastric MALT lymphoma.

BACKGROUND: t(11;18)(q21;q21) resulting in the API2-MALT1 fusion transcript is an exclusive finding in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). While it has recently been demonstrated as a negative predictor for gastric MALT lymphoma undergoing eradication of Helicobacter pylori, nothing is known about the relation between t(11;18)(q21;q21) status and response to chemotherapy. We have therefore performed a retrospective analysis of t(11;18)(q21;q21) in patients undergoing chemotherapy with the nucleoside analogue cladribine (2CdA) for gastric MALT lymphoma. PATIENTS AND METHODS: Eighteen cases of gastric MALT lymphoma treated with 2CdA were reviewed, and 17 could be investigated for t(11;18)(q21;q21) by reverse-transcription polymerase chain reaction and fluorescence in situ hybridization. t(11;18)(q21;q21) was correlated with response to chemotherapy. RESULTS: Of the 17 patients with gastric MALT lymphoma treated with 2CdA, 9 were at stage IE, 2 at stage IIE and 6 at stage IV. Eight cases with stage IE lymphoma were first treated with H. pylori eradication, but none of them showed histological regression during a minimum follow-up of 12 months, and they were subsequently treated with primary chemotherapy. One patient received chemotherapy due to absence of H. pylori infection. Another patient initially rated as stage IE whose gastric lymphoma did not respond developed spread to the lung during follow-up after eradication. All the remaining 13 cases were treated by chemotherapy at the time of diagnosis. Out of these 17, 8 patients (47%) were found to carry t(11;18)(q21;q21). One patient, who was negative for t(11;18)(q21;q21), progressed during chemotherapy and died 5 months after initiation of treatment. One patient each with and without t(11;18)(q21; q21) had a partial response lasting for 14 and >18 months, respectively. One t(11;18)(q21;q21)-positive patient had stable disease for >16 months. The remaining patients achieved a complete remission (CR) following treatment; 6 were positive for t(11;18)(q21;q21), while the remaining 6 were negative. Two patients [1 positive and 1 negative for t(11;18)(q21;q21), respectively] have developed a local relapse following CR and were salvaged by radiotherapy. CONCLUSION: Our findings suggest that the presence of the API2-MALT1 fusion transcript resulting from t(11;18)(q21;q21) does not adversely affect the response of gastric MALT lymphoma to chemotherapy with 2CdA. 2CdA appears to be an attractive agent for treatment of gastric MALT lymphoma unresponsive to H. pylori eradication, including those positive for t(11;18)(q21;q21).

Adult↗
PubMed2006

MALT lymphoma and extranodal diffuse large B-cell lymphoma are targeted by aberrant somatic hypermutation.

Recently, a novel mechanism introducing genetic instability, termed aberrant somatic hypermutation (ASHM), has been described in diffuse large B-cell lymphoma. To further investigate whether ASHM also occurs in mucosa-associated lymphoid tissue type (MALT) lymphoma, we studied the mutation profile of PIM1, PAX5, RhoH/TTF, and c-MYC in 17 MALT lymphomas and 17 extranodal diffuse large B-cell lymphomas (DLBCLs) still exhibiting a low-grade MALT lymphoma component (transformed MALT lymphoma). Mutations in one or more genes were detected in 13 (76.5%) of 17 cases of MALT lymphomas and in all of 17 (100%) cases of extranodal DLBCL. A total of 100 sequence variants were found in 30 of 34 cases, 28 in the MALT lymphomas and 72 in extranodal DLBCL. Further, in PIM1 and c-MYC some of the mutations were found to affect coding exons, leading to amino acid exchanges, thus potentially altering gene function. Expression levels of activation-induced cytidine deaminase (AID), an enzyme essential for somatic hypermutation (SHM), was associated with the mutational load. These data indicate that aberrant SHM is associated with extranodal DLBCL and MALT lymphoma, likewise. By mutating regulatory and coding sequences of the targeted genes, ASHM may represent a major contributor to their pathogenesis.

Genomic Instability↗
PubMed2002

Gastric marginal zone B-cell lymphomas of MALT type develop along 2 distinct pathogenetic pathways.

Low-grade marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type can transform into high-grade diffuse large B-cell lymphoma (DLBCL). Up to 60% of the MALT lymphomas contain the recently described t(11;18). However, this translocation has not been detected in any DLBCL so far. To elucidate the pathogenesis of these tumors, microsatellite screening of 24 gastric MALT lymphomas was performed and the results were compared with aberrations detected in a previous study on gastric DLBCL. The most frequent aberration, found in 21% of the MALT lymphomas that were exclusively t(11;18)-negative cases, was amplification of the 3q26.2-27 region (harboring the locus of the BCL6 gene). Allelic imbalances in regions 3q26.2-27, 6q23.3-25, 7q31, 11q23-24, and 18q21 were shared by both MALT lymphoma and DLBCL. Loss of heterozygosity in regions 5q21 (APC gene locus), 9p21 (INK4A/ARF), 13q14 (RB), and 17p13 (p53) and allelic imbalances in 2p16, 6p23, and 12p12-13 occurred exclusively in DLBCL. Only one of 10 t(11;18)-positive MALT lymphomas showed an additional clonal abnormality. These tumors thus display features of a clonal proliferation characterized by the presence of the t(11;18). However, they only rarely display secondary aberrations and do not seem to transform into DLBCL. In contrast, t(11;18)-negative MALT lymphomas show numerous allelic imbalances--some of them identical with aberrations seen in DLBCL--suggesting that this group is the source of tumors eventually transforming into high-grade DLBCL.

Adult↗
PubMed2004

Helicobacter pylori (H. pylori) molecular signature in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma.

Conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal marginal zone B-cell lymphoma that is characterized by an exaggerated clonal expansion of B cells, which implicate a pathological proliferative response to antigen(s) including bacteria. Helicobacter pylori (H. pylori) infection is recognized as one of the causative agents of gastric MALT lymphoma; however, it has not been reported in extra gastric MALT lymphoma. We studied 5 patients (4 adults and 1 child) with salmon-colored conjunctival lesions. One patient also had a history of abnormal bone marrow biopsy a year earlier with lymphoid aggregates involving 5% of the overall bone marrow. The conjunctival lesions of the 5 patients were biopsied. Histopathological diagnoses were consistent with conjunctival MALT lymphoma. Lymphoma and normal conjunctival cells were microdissected using laser capture microscopy or manual techniques. DNA was extracted and subjected to PCR amplification using H. pylori gene-specific primers from the urease B and vac/m2 gene. Cells from chronic conjunctivitis (normal lymphocytes), conjunctival human T-cell lymphotropic virus type-1/adult T-cell leukemia/lymphoma (HTLV-1/ATL), and orbital B-cell lymphoma were also microdissected, processed and analyzed. PCR amplification and Southern blot hybridization demonstrated H. pylori DNA in the conjunctival MALT lymphoma cells of 4/5 cases. The negative case was the one with a history of abnormal bone marrow. In contrast, H. pylori gene was not detected in normal conjunctival cells from the cases of MALT lymphoma or the lymphocytes, ATL and orbital B-lymphoma cells from the controls. These data suggest that H. pylori may play a role in conjunctival MALT lymphoma.

Aged↗
PubMed1996

Effect of malting time on chemical composition and functional properties of soybean and bambara groundnut flours.

Soybean and bambara groundnut were malted for 0, 24, 48, 72, 96 and 120 h, respectively. The malted beans were dried, devegetated and milled into flour. The protein contents of unmalted soybean and bambara groundnut flours which were 48.3 and 18.8% (dry weight), respectively, increased on malting to maximum levels of 56.17 and 28.55% (dry weight) after 2 days before decreasing to 19.51 and 20.92% (dry weight) for soybean and bambara groundnut flours, respectively. The same pattern of change was observed for the fat, soluble sugar and nitrogen contents of the malted bean flours. Approximately 76 and 59% of the phytic acid contents of soybean and bambara groundnut flours were removed, respectively, on malting for 120 h. Malting significantly affected the water and oil absorption capacities as well as the viscosities of both bean flours. The optimum malting time for both beans was found to be between 72 and 96 h.

Adsorption↗
PubMed1986

Malt sprouts as a source of supplemental protein for ruminants.

Nitrogen solubility, ruminal degradation, and amino acid composition of pelleted malt sprouts, pelleted corn gluten feed, and soybean meal were studied. Four rumen-cannulated steers were fed diets containing 45% pelleted malt sprouts or 45% pelleted corn gluten feed in a 2 X 2 crossover design with 15-d periods. Ruminal degradation of dry matter and nitrogen from malt sprouts or corn gluten feed was estimated by disappearance of these components from polyester bags after 1, 2, 3, 4, 6, 8, 10, 12, 16, or 24 h of in situ fermentation. For comparison, degradation of soybean meal after 2, 4, 8, or 24 h was measured. Malt sprouts had less soluble nitrogen than corn gluten feed, but available crude protein contents were similar. Malt sprouts dry matter was degraded more slowly than was corn gluten feed dry matter. Nitrogen degradation rates of the two feeds, after correction for unavailable nitrogen, did not differ. Malt sprouts had higher concentrations of arginine, lysine, and aspartate than corn gluten feed; however, corn gluten feed had higher concentrations of the other amino acids measured. Malt sprouts would be expected to provide more amino acids of feed origin to the lower gut of ruminants, provided passage rates of the supplements are similar.

Animal Feed↗