BCL6 gene rearrangements also occur in marginal zone B-cell lymphoma

Marginal zone B-cell lymphoma (MZBCL) represents a distinct subtype of B-cell non-Hodgkin's lymphoma (NHL) which has been recently recognized and defined as a disease entity. Cytogenetically, these lymphomas reveal a high prevalence of trisomy 3, and recent data obtained by comparative genomic hybridization indicate that the chromosomal regions 3q21-23 and 3q25-29 might be of particular pathogenetic significance. We identified structural chromosomal abnormalities involving the region 3q27 and rearrangements of the BCL6 proto-oncogene in three out of 34 (9%) well-defined cases of extranodal, nodal and splenic MZBCL using cytogenetic analysis. Southern blot, and fluorescence in situ hybridization (FISH). All three cases were characterized by a t(3;14)(q27;q32). Two of them showed additional chromosomal abnormalities including trisomy 3, which was found in one case. The patients displayed extranodal disease and did not demonstrate any striking clinical and histological differences when compared with MZBCL lacking BCL6 rearrangement. The present study for the first time demonstrates the occurrence of t(3;14)/BCL6 gene rearrangement in MZBCL, thus suggesting a role of the BCL6 proto-oncogene in the pathogenesis of MZBCL.     

Clinical relevance of BCL2, BCL6, and MYC rearrangements in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLCL) is characterized by a marked degree of morphologic and clinical heterogeneity. We studied 156 patients with de novo DLCL for rearrangements of the BCL2, BCL6, and MYC oncogenes by Southern blot analysis and BCL2 protein expression. We related these data to the primary site of presentation, disease stage, and other clinical risk factors. Structural alterations of BCL2, BCL6, and MYC were detected in 25 of 156, 36 of 116, and 10 of 151 patients, respectively. Three cases showed a combination of BCL2 and BCL6 rearrangements, and two cases had a combination of BCL6 and MYC rearrangements. BCL2 rearrangement was found more often in extensive (39%) and primary nodal (17%) lymphomas than in extranodal cases (4%) (P = .003). BCL2 rearrangement was present in none of 40 patients with stage I disease, but in 22% of patients with stage II to IV (P = .006). The presence of BCL2 rearrangements did not significantly affect overall survival (OS) or disease-free survival (DFS). In contrast, high BCL2 protein expression adversely affected both OS (P = .008) and DFS (P = .01). BCL2 protein expression was poorly correlated with BCL2 rearrangement: only 52% of BCL2-rearranged lymphomas and 37% of BCL2-unrearranged cases had high BCL2 protein expression. Rearrangement of BCL6 was found more often in patients with extranodal (36%) and extensive (39%) presentation versus primary nodal disease (28%). No significant correlation was found with disease stage, lymphadenopathy, or bone marrow involvement. DFS and OS were not influenced by BCL6 rearrangements. MYC rearrangements were found in 16% of primary extranodal lymphomas, versus 2% of primary nodal cases (P = .02). In particular, gastrointestinal (GI) lymphomas (5 of 18 cases, 28%) were affected by MYC rearrangements. The distinct biologic behavior of these extranodal lymphomas was reflected by a high complete remission (CR) rate: 7 of 10 patients with MYC rearrangement attained complete remission and 6 responders remained alive for more than 4 years, resulting in a trend for better DFS (P = .07). These data show the complex nature of molecular events in DLCL, which is a reflection of the morphologic and clinical heterogeneity of these lymphomas. However, thus far, these genetic rearrangements fail as prognostic markers.     

VH gene analysis of primary cutaneous B-cell lymphomas: evidence for ongoing somatic hypermutation and isotype switching

Primary cutaneous B-cell lymphomas are B-cell non-Hodgkin's lymphomas that arise in the skin. The major subtypes discerned are follicle center cell lymphomas, immunocytomas (marginal zone B-cell lymphomas), and large B-cell lymphomas of the leg. In this study, we analyzed the variable heavy chain (VH) genes of 7 of these lymphomas, ie, 4 follicle center cell lymphomas (diffuse large-cell lymphomas) and 3 immunocytomas. We show that all these lymphomas carry heavily mutated VH genes, with no obvious bias in VH gene usage. The low ratios of replacement versus silent mutations observed in the framework regions of 5 of the 7 lymphomas suggest that the structure of the B-cell antigen receptor was preserved, as in normal B cells that are selected for antibody expression. Moreover, evidence for ongoing mutation was obtained in 3 immunocytomas and in one lymphoma of large-cell type. In addition, in 1 immunocytoma, both IgG- and IgA-expressing clones were found, indicative of isotype switching. Our data provide insight into the biology of primary cutaneous B-cell lymphomas and may be of significance for their classification.     

BCL6 gene rearrangement and other cytogenetic abnormalities in diffuse large cell lymphoma

Evidence for rearrangement of the BCL6 gene at 3q27 has been documented in 20-30% diffuse lymphomas with a large cell component (DLLC), and was found to be of prognostic significance at the time of diagnosis. To incorporate these observations into current cytogenetic and clinical prognostic models, 76 cases of DLLC with known BCL6 status were analyzed. Cytogenetic indicators of progression, including trisomy 7, trisomy 12, del(6)(q21q25), and structural alterations of 17p were less frequent in BCL6 rearranged DLLC compared to BCL6 germline tumors. Despite a 93% overall survival at median follow-up of 30 months, a trend for continued relapse resulted in a projected freedom from progression for the BCL6 rearranged cohort of 66% at 4 years, compared to 39% for the BCL6 germline cohort. Six cases among the BCL6 rearranged group lacked additional cytogenetic indicators of progression and remained free of disease at follow-up in excess of 7 years, whereas BCL6 rearranged cases with increasing numbers of cytogenetic aberrations showed decreased intervals free from progression of disease. These results suggest that BCL6 rearrangement should be combined with other known clinical and cytogenetic indicators in prognostic analyses of patients with DLLC.     

Identification of two novel 5'' noncoding exons in human MNB/DYRK gene and alternatively spliced transcripts

OBJECTIVES: This study was performed to determine the degree and time course over 6 years of cardiomyocyte hypertrophy and myocardial fibrosis of the cardiac allograft in transplanted patients. BACKGROUND: Diastolic dysfunction and to a certain extent systolic dysfunction are common cardiac findings after heart transplantation. The development of posttransplant cardiomyocyte hypertrophy and myocardial fibrosis likely contributes to these derangements. METHODS: Cardiomyocyte diameter and percent fibrosis were determined in serial endomyocardial biopsy specimens obtained from 1 month up to 6 years following heart transplantation in 50 patients. Endomyocardial biopsy specimens from 40 patients with primary dilated cardiomyopathy and 11 normal subjects were similarly analyzed for control data. Analyses were performed in a blinded format using a validated computerized image analysis system (Optimas 5.2). RESULTS: Early (1 month) cardiomyocyte enlargement decreased to the smallest diameter 6 months posttransplant, but thereafter progressively increased by 10% to 20% over the subsequent 5- to 6-year period. Although not statistically established, principal stimuli may include a discrepancy in body size (recipient > donor), coronary allograft vasculopathy and posttransplant systemic hypertension. Percent myocardial fibrosis rose early (1 to 2 months) posttransplant and thereafter remained at the same modest level of severity. CONCLUSIONS: Cardiomyocyte diameter of the transplanted heart gradually increases over time, while percent myocardial fibrosis rises early and remains in a modestly elevated plateau after 2 months posttransplant. These histostructural changes likely contribute to the hemodynamic and cardiac functional alterations commonly observed posttransplant.     

A sequence in the 5'' flanking region confers progestin responsiveness on the human c-myc gene

Sarcoidosis is a systemic granulomatous disease of undetermined etiology in which the immune system is overstimulated. Management of the patient with sarcoidosis entails continuity of patient care far beyond disease, even into remission. Care is comprehensive, including all involved organ systems, coordination of specialty consultations and services, and includes diagnostic tests. Therapeutic decisions are the responsibility of the primary care practitioner. Prognosis of sarcoidosis is not uniformly good. Patients can die. Subacute sarcoidosis patients usually do not require pharmacologic therapy. Chronic sarcoidosis may require long-term treatment for years to indefinitely. Corticosteroids are still the drugs of choice and other therapy is now available. Health organizations and private nonprofit support groups are available for patient education and assistance. Close support must still come from the family unit. Sarcoidosis may occur in family members in different cohorts at all ages in life and in any racial or ethnic group. The second in a two-part series on management of the patient with sarcoidosis, this article describes coordination of care and considers community, prevention, and family aspects of the disease.     

Rearrangements of the BCL6 gene and chromosome aberrations affecting 3q27 in 54 patients with non-Hodgkin's lymphoma

Chromosome aberrations affecting 3q27 are among the most frequent non-random abnormalities in non-Hodgkin's lymphomas (NHL), especially the diffuse, large cell type. Recently, an association between BCL6 rearrangement and frequent extranodal lesions, rare bone marrow infiltration and a favorable clinical outcome was reported. We performed molecular studies of the BCL6 gene in 54 patients with NHL. Twelve patients (22%) with rearranged BCL6 genes were selected for histological, clinical, molecular, and cytogenetic studies. Ten of these cases were diffuse, large cell type lymphoma, one a follicular lymphoma, and one a mantle cell lymphoma (MCL). All cases were of the B-cell type and this is the first time a rearranged BCL6 gene has been found in an MCL. Cytogenetic data for 10 cases were available and the partner sites of the 3q27 translocation were determined in 7 of 10 patients. These locations were variable, including 6p21.3, 9p22, and 14q11 in addition to the immunoglobulin loci 14q32 (IGH), 2p12 (IGK), and 22q11 (IGL). The heterogeneity in partner sites is distinct from other lymphoma subgroups and may suggest that the genetic events are not uniform among patients with BCL6 rearrangements.     

Bias in somatic hypermutation of human VH genes

Translationally silent mutations, which are not antigen selected, of human VH6 Ig gene rearrangements isolated from human spleen were analyzed for bias to gain insight into intrinsic features of the mutation process. Sixty-three clones representing 38 VH6DJ rearrangements had an overall mutation frequency of 4.5%, a replacement/silent (R/S) mutation ratio of 2.1 and 167 unique silent mutations. The silent mutations showed bias in: (i) targeting to CDR1 and CDR2, (ii) an increased frequency of mutations of A compared to T nucleotide bases on the coding strand, and (iii) an increased frequency of transitions versus transversions. Bias of C-->G over C-->A, of G-->C over G-->T and of A-->C over A-->T transversions was also present. Hot spots of mutation were observed, some which corresponded to potential sites of stem-loop formation. The results suggest that the somatic mutation process in man may be targeted to the complementarity determining region for some V genes, exhibits specific base substitutions favoring transitions and specific types of transversions, and may be occurring on only one DNA strand.     

Expression of the BCL6 gene in the pre- and postnatal mouse

Langerhans cell histiocytosis may be seen with goiter and histiocytic infiltration of the thyroid. We report a 2 1/2-year-old boy who had goiter and primary hypothyroidism develop, later had pulmonary disease, and died of neurologic involvement. Autopsy lesions suggested a transitional dendritic cell precursor of the epidermal Langerhans cell. Of the reported cases of Langerhans cell histiocytosis with goiter in children and adolescents, 82% were male when the relative incidence of Langerhans cell histiocytosis is two males to one female.     

Frequent deletion and 5' CpG island methylation of the p16 gene in primary malignant lymphoma of the brain

A total of 10 primary malignant lymphomas of the brain were examined for deletion, mutation, and 5' CpG island methylation of the p16 gene, which is a candidate tumor suppressor gene with CDK-inhibitory function. In Southern blot analysis, p16 gene deletion was suggested in nine cases, homozygously (five cases) or hemizygously (four cases). In the remaining one case, p16 gene deletion was not suggested. Although single-strand conformation polymorphism and nucleotide analyses suggested no mutations of the p16 gene in these cases, methylation analyses revealed 5' CpG island methylation in three cases, of which two were those with presumed hemizygous deletion and one was that without deletion in Southern blot analysis. Thus, p16 gene abnormality was detected in all 10 of the brain lymphomas examined, and in 8 of them, actual p16 gene inactivation was suggested by their homozygous deletion (5 cases) or 5' CpG island methylation (3 cases). These findings suggest that p16 gene abnormality and inactivation are closely related to carcinogenesis in primary malignant lymphoma of the brain. The p15 gene, another candidate tumor suppressor gene located in the vicinity of the p16 gene, to which it shows structural and functional similarity, was also presumed to be deleted similarly in most cases. Its methylation was seen in one case, the case without the methylated p16 gene.     

A cis-regulatory element within the 5'' flanking region of arylsulfatase gene of sea urchin, Hemicentrotus pulcherrimus

Mycobacteria generally have thick cell walls and contain large amounts of lipid, making them resistant to DNA extraction. Five methods, namely, extensive enzymic digestion method (M1), 2-min mechanical glass-bead disruption method (M2), thermal shock method (M3), modified conventional enzymic digestion method (M4), and manual disruption with modified conventional enzymic digestion method (M5), were used to compare their effectiveness and simplicity in extracting DNA from slowly growing mycobacteria (Mycobacterium leprae, M. lepraemurium and M. bovis BCG), and a rapidly growing mycobacterium (M. phlei). The highest DNA yield was obtained by M2 from M. lepraemurium which produced 2.82 micrograms DNA/mg wet weight of cells, representing a theoretical yield of 78%. M3 gave the lowest DNA yield; 0.01 microgram DNA/mg wet weight of cells of M. lepraemurium was obtained. M4, in which proteinase K was used, is more effective than M1, in which subtilisin and pronase were used. M5 yielded a higher amount of DNA, but it required more manipulations to extract DNA as compared to M4. Extraction of DNA of M. leprae from nude mice is more difficult than that of M. leprae from armadillos by all of the methods used. These results suggest that the biosynthetic capabilities of these two forms of M. leprae may vary, depending on their cultural conditions and/or strain differences. Our results have shown that both M2 and M4 are the simplest, most effective and time-saving methods which are suitable for every routine laboratory to extract DNA from slowly and rapidly growing mycobacteria.     

Cloning and characterization of the 5'' flanking sequences (promoter region) of the human GLP-1 receptor gene

We have investigated in rat brain slices the effects of the volatile anaesthetics enflurane, isoflurane and halothane on spontaneous discharge patterns and mean firing rates of cerebellar Purkinje cells. In the absence of these anaesthetics, Purkinje cells fired bursts of action potentials separated by quiescent periods lasting less than 2 s. Mean discharge rates were 10.8 (SEM 0.4) Hz at 23 +/- 1 degrees C and 25.6 (1.2) Hz at 35 +/- 1 degrees C. The agents exhibited qualitatively different effects when applied at concentrations corresponding to 1-3 MAC. Enflurane markedly lengthened burst and inter-burst durations. Isoflurane acted in a similar manner, but effects were less pronounced. In contrast with isoflurane and enflurane, halothane shortened burst durations. At concentrations corresponding to 1-1.5 MAC, halothane, isoflurane and enflurane significantly depressed action potential firing by 15-30% (P < 0.05). Enflurane 1.2 mmol litre-1 (2.0 MAC), isoflurane 0.9 mmol litre-1 (2.8 MAC) and halothane 0.9 mmol litre-1 (3.8 MAC) depressed spontaneous spike rates by 50%. The changes in discharge patterns and the concentration-dependent decrease in the firing rates were similar at 23 +/- 1 degrees C and 35 +/- 1 degrees C. In summary, we observed that neither the anaesthetic-induced alterations in spontaneous discharge patterns nor the EC50 values of the concentration-dependent depression of the mean firing rates were in accordance with the Meyer-Overton rule. However, at clinically relevant concentrations, depression of average spike rates did not differ significantly between the anaesthetics and thus followed the rule. Our results suggest that anaesthetic actions, which are in accordance with the rule, are frequently masked by several side effects.     

The 5'' region of intron 11 of the dystrophin gene contains target sequences for mobile elements and three overlapping ORFs

This paper locates the need for an urban health agenda in a broader social context. This broader context is characterized by increasing diversity and extensive privatization--developments that accentuate tendencies leading away from a shared sense of the common good. The paper then outlines ways that Columbia University seeks to work for healthier cities in this challenging context.     

A rearrangement of the CDD gene at the 5'' UTR produces two types of transcripts that contain a natural antisense region

BACKGROUND: Mothers with multiple sclerosis (MS) often face fatigue and episodic exacerbations during their child-rearing years. These problems affect their support of their children, including physical affection. Children, depending on their age and gender, may or may not understand the changes. OBJECTIVES: To increase knowledge about mothers with MS concerning the relationship of fatigue and functional status to the perception of physical affection with their children, their perceptions of physical affection with their children in relation to exacerbation of their symptoms and the age and gender of their children, and the children's perceptions of their mothers' physical affection in relation to the children's age and gender and exacerbations in their mothers' symptoms. METHOD: Thirty-five mothers with relapsing-remitting MS and a child of each mother were studied, using interviews and questionnaires. RESULTS: Functional status and fatigue were not significant predictors of physical affection during an exacerbation. When the mothers' symptoms were stable, perceptions of mothers and children with respect to maternal physical affection were similar. Significant changes were reported in both the mothers' perceptions of their physical affection and the children's perceptions of their mothers' physical affection during exacerbations. There was a significant difference between the perceptions of the mothers and children regarding the magnitude of that change. Mothers significantly underestimated changes in their physical affection. CONCLUSIONS: Physical affection was selected as an important aspect of family functioning that could be affected by characteristics of illness, including exacerbations, fatigue, and functional status. However, fatigue and functional status did not explain the perception of physical affection during an exacerbation.