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Originally viewed as monstrosities or scientific curiosities, developmental anomalies have been widely reported in arthropods since the nineteenth century. However, it was only after Wheeler's studies on ants and Balazuc's investigations on numerous other arthropods that anomalous individuals began to be systematically analyzed. Denominations for these individuals have varied greatly, generating a confusing or often contradictory nomenclature. In Hymenoptera, sexual dimorphism arises from a haplodiploid sex-determination system. During embryonic and post-embryonic development, defects can result in the formation of abnormal individuals carrying morphological or genetic aberrations that can be classified according to criteria based on body location. Gynandromorphs or sex mosaics are individuals that simultaneously display male and female characters, either bilaterally or in mosaics. Other somatic abnormalities may be a consequence of defects and injuries that occurred during embryonic or post-embryonic development. Using literature data on 85 species of ants distributed in 8 subfamilies and detailed descriptions of a series of collection individuals, we reviewed the current definitions of somatic developmental anomalies and proposed a simplified classification based on currently available nomenclature. In addition to presenting a causality discussion, we arranged the cases of gynandromorphs, mosaics, and teratological forms in a sequence and hypothesized about the temporal origin of alterations. The large majority of cases reported in the literature are of gynandromorphism, followed by teratology. Analysis of such phenomena raises behavioral, genetic, and ecological questions related to the viability of anomalous individuals. [ABSTRACT FROM AUTHOR]

Ant inquiline social parasites obligately depend on their hosts for survival and reproduction. Because of their shift from a eusocial to a socially parasitic life history, inquiline social parasites are interesting study systems for exploring the dynamics between conflict and cooperation in eusocial insect colonies. In addition, inquiline social parasites are of interest to evolutionary biology, because some species evolved directly from their hosts via sympatric speciation. With five described species, inquiline social parasites are relatively diverse in the fungus-growing ants. So far, four species have been reported from the leaf-cutting ant genus Acromyrmex and its closely affiliated social parasite genus Pseudoatta. In contrast, only a single parasite species was described from the lower attine genus Mycocepurus. Here, we describe a new species of inquiline social parasite, Acromyrmex fowleri sp. nov., which was discovered 27 years ago in the tropical region of Brazil (State of Bahia), living inside the colonies of its host Acromyrmex rugosus. We also report observations on the behavioral ecology and natural history of A. fowleri and its host. Our study suggests that A. fowleri is an obligate, queen-tolerant, workerless inquiline social parasite of A. rugosus and that A. fowleri represents some but not all morphological and life history characters of the inquiline syndrome, supporting the hypothesis that the complex traits of the inquiline syndrome evolve in a mosaic fashion. Considering that A. fowleri is a new social parasite species from tropical Brazil, we discuss the paradoxical biogeographic distribution of ant social parasites, which we refer to as the "Kutter–Wilson Paradox", and conclude that the Kutter–Wilson Paradox is a genuine biogeographical pattern, instead of being a mere sampling artifact. [ABSTRACT FROM AUTHOR]

Nest-site limitation is an important factor regulating ant diversity, particularly at low elevations. In savannas, trees and shrubs do not support large nests in their crowns and cavities for nest sites are limited. However, bamboos are very common and can provide vertically stacked hollow chambers for ants to establish their colonies. We evaluated the bamboo species Guadua paniculata as a source of nest cavities for ants in the Cerrado (Brazilian savanna). We hypothesized that the morphology of this bamboo species and its vertical arrangement regulate the distribution of ants nesting in it. Thirty bamboo patches distributed among four sites in the state of Tocantins (Brazil) were evaluated, in which 36 species of ants occupied more than half of the bamboo available. Wider and longer culms enabled a greater number of colonies of several ant species. Living or dead condition of bamboo had a significant effect on the diversity and composition of the ant fauna. Dead culms were occupied opportunistically by several generalist species, while Azteca fasciata dominated living bamboo. Finally, we observed the species distribution along a vertical gradient of bamboo height, and proposed that differential colonization of ground and canopy-dwelling species and habitat specialization may be key mechanisms for the observed pattern of distribution. This study contributes to a better understanding of species coexistence in low elevation forests in the Brazilian Cerrado by considering bamboo nest sites as a key factor affecting ant diversity. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cell lymphomas/leukemias are rare neoplasms with an aggressive clinical behavior. The majority of the cases belong to extranodal NK/T-cell lymphoma, nasal type (ENKTL) in the current WHO classification scheme. Gene-expression profiling (GEP) of 21 ENKTL and NK-cell lymphoma/leukemia patients, 17 NK- and T-cell lines and 5 indolent NK-cell large-granular-lymphocytic proliferation was performed and compared with 125 peripheral T-cell lymphoma (PTCL) patients previously studied. The molecular classifier derived for ENKTL patients was comprised of 84 transcripts with the majority of them contributed by the neoplastic NK cells. The classifier also identified a set of γδ-PTCLs both in the ENKTL cases as well as in cases initially classified as PTCL-not otherwise specified. These γδ-PTCLs expressed transcripts associated with the T-cell receptor (TCR)/CD3 complex, suggesting T cell rather than NK-cell lineage. They were very similar to NK-cell tumors by GEP, but were distinct from cytotoxic (αβ)-PTCL and hepatosplenic T-cell lymphoma, indicating derivation from an ontogenically and functionally distinct subset of γδ T cells. They showed distinct expression of Vγ9, Vδ2 transcripts and were positive for TCRγ, but negative for TCRβ by immunohistochemistry. Targeted inhibition of two oncogenic pathways (AURKA and NOTCH-1) by small-molecular inhibitors induced significant growth arrest in NK-cell lines, thus providing a rationale for clinical trials of these inhibitors in NK-cell malignancies. [ABSTRACT FROM AUTHOR]

In an initial epigenetic characterization of diffuse large B-cell lymphoma (DLBCL), we evaluated the DNA methylation levels of over 500 CpG islands. Twelve CpG islands (AR, CDKN1C, DLC1, DRD2, GATA4, GDNF, GRIN2B, MTHFR, MYOD1, NEUROD1, ONECUT2 and TFAP2A) showed significant methylation in over 85% of tumors. Interestingly, the methylation levels of a CpG island proximal to FLJ21062 differed between the activated B-cell-like (ABC-DLBCL) and germinal center B-cell-like (GCB-DLBCL) subtypes. In addition, we compared the methylation and expression status of 67 genes proximal (within 500 bp) to the methylation assays. We frequently observed that hypermethylated CpG islands are proximal to genes that are expressed at low or undetectable levels in tumors. However, many of these same genes were also poorly expressed in DLBCL tumors where their cognate CpG islands were hypomethylated. Nevertheless, the proportional reductions in BNIP3, MGMT, RBP1, GATA4, IGSF4, CRABP1 and FLJ21062 expression with increasing methylation suggest that epigenetic processes strongly influence these genes. Lastly, the moderate expression of several genes proximal to hypermethylated CpG tracts suggests that DNA methylation assays are not always accurate predictors of gene silencing. Overall, further investigation of the highlighted CpG islands as potential clinical biomarkers is warranted. [ABSTRACT FROM AUTHOR]

Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed biologically and prognostically distinct subgroups: germinal center B-cell-like (GCB), activated B-cell-like (ABC) and primary mediastinal (PM) DLBCL. The BCL6 gene is often translocated and/or mutated in DLBCL. Therefore, we examined the BCL6 molecular alterations in these DLBCL subgroups, and their impact on BCL6 expression and BCL6 target gene repression. BCL6 translocations at the major breakpoint region (MBR) were detected in 25 (18.8%) of 133 DLBCL cases, with a higher frequency in the PM (33%) and ABC (24%) subgroups than in the GCB (10%) subgroup. Translocations at the alternative breakpoint region (ABR) were detected in five (6.4%) of 78 DLBCL cases, with three cases in ABC and one case each in the GCB and the unclassifiable subgroups. The translocated cases involved IgH and non-IgH partners in about equal frequency and were not associated with different levels of BCL6 mRNA and protein expression. BCL6 mutations were detected in 61% of DLBCL cases, with a significantly higher frequency in the GCB and PM subgroups (>70%) than in the ABC subgroup (44%). Exon-1 mutations were mostly observed in the GCB subgroup. The repression of known BCL6 target genes correlated with the level of BCL6 mRNA and protein expression in GCB and ABC subgroups but not with BCL6 translocation and intronic mutations. No clear inverse correlation between BCL6 expression and p53 expression was observed. Patients with higher BCL6 mRNA or protein expression had a significantly better overall survival. The biological role of BCL6 in translocated cases where repression of known target genes is not demonstrated is intriguing and warrants further investigation. [ABSTRACT FROM AUTHOR]

Comparative genomic hybridization (CGH) was employed to study chromosomal aberrations in relation to cell proliferation, apoptosis, and patient survival in 94 cases of B-cell non-Hodgkin's lymphoma diagnosed between 1983 and 1993. Eighty cases had aberrations by CGH. Chromosomal regions 1p21-31.1 (10%), 6cen-q24 (12%), 8p (11%), 9p21-ter (14%), 11q21-23.1 (11%), 13q13-21.1 (12%), and 17p (15%) were frequently lost. Gains were found at 3q21-ter (22%), 6p (11%), 7p (12%), 8q23-ter (13%), 12cen-q15 (17%), 17q24-ter (13%), and 18q13.3-21 (20%). A high number of aberrations (≥ 4, 33 cases) was associated (P ≤ 0.001) with the mantle cell and diffuse large B-cell lymphoma subtypes, a high fraction of tumour cells in S phase, and short survival (RR (relative risk) = 3.7). Loss of 1p21-31.1, 8p, 9p21-ter, 11q21-23.1, and 13q13-21.1 were associated with mantle cell lymphoma (P ≤ 0.03), while gain of 6p and 12cen-q15 were more frequent in diffuse large B-cell and small lymphocytic lymphoma, respectively (P = 0.04). Loss of 8p and 17p, and gain of 3q21-ter, 6p, 7p, and 8q23-ter were associated with a high S phase fraction (P ≤ 0.03), but none of the aberrations were associated with tumour apoptotic fraction (P ≥ 0.13). The most important prognostic CGH parameters (P < 0.001) were losses of 11q21-23.1 (RR = 3.8) and 17p (RR = 4.4), and gain of 6p (RR = 4.2). The latter parameters and IPI were the only ones with independent prognostic value (RR = 10, 5.0, 6.7, and 3.7, respectively; P < 0.001) when assessed together with lymphoma sub-type, primary versus relapse cases, treatment, B symptoms, S phase fraction, and presence of BCL1 and BCL2 translocations. A combined CGH/IPI binary parameter had high prognostic value for patients receiving different treatments, with various lymphoma sub-types, and for primary as well as relapse cases. [ABSTRACT FROM AUTHOR]

Register data suggest that patients with Hodgkin’s disease (HD) given high-dose therapy (HDT) with peripheral blood progenitor cells (PBPC) have a less favourable prognosis as compared to those given bone marrow as stem cell support. Since this can be due to infusion of tumour cells contaminating the PBPC grafts, we initiated a feasibility study in which PBPC grafts from HD patients were purged by CD34+ cell enrichment. Controversy exists about whether the use of CD34+ enriched stem cells leads to a delayed haematological and immune reconstitution. We compared these parameters, including risk of infections and clinical outcome after HDT, in patients with HD given either selected CD34+ cells or unmanipulated PBPC as stem cell support. From October 1994 to May 2000, 40 HD patients with primary refractory disease or relapse were treated with HDT and supported with either selected CD34+ cells (n = 21) or unmanipulated PBPC (n = 19) as stem cell support. All patients had chemosensitive disease at the time of transplantation. A median of 5.8 (range 2.7–20.0) vs 4.5 (range 2.3–17.6) × 106 CD34+ cells per kilo were reinfused in the CD34+ group and PBPC group, respectively. No difference was observed between the two groups with regard to time to haematological engraftment, reconstitution of B cells, CD56+ cells and T cells at 3 and 12 months and infectious episodes after HDT. Two (5%) treatment-related deaths, one in each group, were observed. The overall survival at 4 years was 86% for the CD34+group and 74% for the PBPC group with a median follow-up of 37 months (range 1–61) and 46 months (range 4–82), respectively (P = 0.9). The results of this study demonstrate that the use of CD34+ cells is safe and has no adverse effects either with respect to haematological, immune reconstitution or to infections after HDT. Bone... [ABSTRACT FROM AUTHOR]

Queens of the neotropical ponerine ant Pachycondyla cf. 'inversa' may cooperate during colony founding. Pleometrosis leads to permanent primary polygyny, with queens still co-existing in the same nest when the colony has become mature. Using multilocus DNA-fingerprinting we examined the genetic structure of colonies. Nestmate queens are typically not close relatives. Excepting one pair of queens, which appeared to be closely related, the band-sharing coefficients of co-occurring queens were similar to the background similarity among individuals from different nests. In mature colonies, queens typically contribute equally to workers and sexuals. Only in one of seven colonies did one queen produce significantly more workers than the other. Polygynous ants with unrelated queens might provide an interesting system to test predictions from kin selection theory. [ABSTRACT FROM AUTHOR]

Peripheral T cell lymphomas (PTCL) have a poorer prognosis after conventional treatment than do high-grade B cell lymphomas. The place for high-dose therapy (HDT) with autologous stem cell support in these patients is still not clear. Forty patients, 10 women and 30 men, median age 41.5 years (range 16–61) with PTCL were treated with HDT and autologous stem cell support at The Norwegian Radium Hospital, Oslo, Norway and The University Hospital, Uppsala, Sweden, between February 1990 and September 1999. The histologic subtypes were: PTCL unspecified, 20 patients; intestinal, two patients; angioimmunoblastic (AILD), two patients; angiocentric, two patients and anaplastic large cell lymphoma (ALCL), 14 patients. All patients had chemosensitive disease and had received anthracycline-containing regimens prior to transplantation. At the time of HDT, 17 patients were in first PR or CR and 23 were in second or third PR or CR. Conditioning regimens were BEAM in 15 patients, BEAC in 14 patients, cyclophosphamide and total body irradiation (TBI) in eight patients, BEAC, without etoposide and TBI in one patient and mitoxantrone and melphalan in two patients. There were three (7.5%) treatment-related deaths. The estimated overall survival (OS) at 3 years was 58%, the event-free survival (EFS) 48% and the relapse-free survival (RFS) 56%, with a median follow-up of 36 months (range 7–100) for surviving patients. The patients with ALCL tended to have a better prognosis compared to those with other PTCL subtypes, OS 79% vs 44%, respectively. In conclusion, patients with chemosensitive PTCL who are failing to achieve CR with first-line chemotherapy or are in relapse can successfully be treated with HDT and autologous stem cell support. Bone Marrow Transplantation (2001) 27, 711–716. [ABSTRACT FROM AUTHOR]

The Atlantic rain forest of south-eastern Brazil has been substantially cleared, resulting in the creation of a fragmented landscape. In addition to the small fragments of forest that remain, the pasture is often scattered with isolated trees. This paper investigates the capacity of these isolated trees to support representatives of the original Atlantic rain forest ant communities and also how these arboreal ants interact with the disturbance-associated ant fauna of the pasture beneath them. Twenty trees in the grassland, representing a range of distances from the forest, and 10 trees within the forest, were selected for sampling. Arboreal ants were sampled by hand collection and chemical knockdown, while the ants on the ground beneath were sampled by pitfall traps and Winkler sacks. Pasture trees supported a moderately high richness of arboreal ant species. The richness of ants on pasture trees appears to be independent of distance from forest, although this might become a significant factor on trees that are more isolated than those studied here. Ant species richness on pasture trees is higher if the trees are large, support a high epiphyte load and are native to the area. Isolated trees within the agricultural matrix therefore play some role in conserving elements of the original forest ant fauna. Since some of the species on pasture trees have been observed to reach dominant or sub-dominant status in nearby forest and cocoa farms, they may play some role in limiting pest outbreaks in the pasture close to the trees. If this is so, there may be a case for retaining an adequate density of trees to enable the influence of arboreal ants to extend over as much pasture as possible. [ABSTRACT FROM AUTHOR]

A case of proliferative myositis in the lumbar paraspinal muscles in a 14-year-old boy is presented. Imaging investigations including plain radiograph, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), bone scan and positron emission tomography (PET) were suggestive of an inflammatory process such as myositis ossificans. The diagnosis was made by incisional biopsy. More pronounced edema, more muscle fiber necrosis and a higher cellularity were found compared to adult cases. The karyotype of the lesion was normal. Clinically, the mass disappeared spontaneously. After 24 months, asymptomatic bridging ossification between the third and fourth lumbar vertebrae was noted. [ABSTRACT FROM AUTHOR]

Gastric low grade MALT lymphomas show a pattern of somatic mutations in their rearranged immunoglobulin genes, indicative of antigen selection. This provides evidence for antigen stimulation in the lymphomagenesis. Gastric diffuse large B cell lymphomas develop secondary to low grade MALT lymphoma or de novo. To study whether antigen-selection is also a feature of primary diffuse large B cell lymphomas, we analysed somatic mutations in the rearranged immunoglobulin heavy chain (IgH) variable genes (VH). The rearranged VH genes of six cases of gastric primary diffuse large B cell lymphoma were amplified from genomic or complementary DNA by a VH gene family-specific polymerase chain reaction method. The PCR products were directly sequenced and were compared to published germline sequences to analyse somatic mutations. Similarly to low grade MALT lymphomas 5/6 primary diffuse large B cell lymphomas show a pattern of somatic mutation in their rearranged VH genes, indicative of antigen selection and suggesting a role for antigens in lymphomagenesis. One case showed bi-allelic VH gene rearrangements, which were non-functional due to extensive deletions. Antigen selection could not be demonstrated or excluded. Antigen selection is a common feature in most analysed primary diffuse large B cell lymphomas, although some heterogeneity in the mechanisms involved in the lymphomagenesis of gastric primary diffuse large B cell lymphomas has not been excluded entirely (case 4). [ABSTRACT FROM AUTHOR]

Ligation of CD28 on T cells with its natural ligands B7-1 (CD80) or B7-2 (CD86) provides a major costimulatory signal for T cells and is of potential importance for tumor rejection. We previously reported a strong expression of B7-1 on Reed-Sternberg cells and anaplastic large cell lymphoma cells. We report here our findings on B7-2 expression by malignant lymphomas (n = 70). B7-2 was present on the neoplastic cells of anaplastic large cell lymphoma in two of three cases studied, and on a subpopulation of the malignant cells in one out of four cases of follicular lymphoma. B7-2 was not expressed by the neoplastic cells of the other non-Hodgkin's lymphomas (n = 32), including T cell-rich B cell lymphoma. In contrast, Reed-Sternberg cells in lymph nodes affected by Hodgkin's disease are strongly positive for B7-2 (n = 31). Evidence for a functional correlate of this expression was obtained by our findings that the combination of anti-B7-1 and anti-B7-2 monoclonal antibodies was more effective than each separately in blocking allogeneic T cell activation (proliferation and cytokine secretion) by Hodgkin's disease-derived cell lines as stimulators. The possible role of B7-1 and B7-2 expression for the course and symptomatology of Hodgkin's disease is discussed. [ABSTRACT FROM AUTHOR]

The composition of the ant community was assessed along standardized 100 m transects in annually flooded Varzea forest and in terra firme forests on sandy soil (Flanco forest) and on claytopped mesas (Planalto forest). Standardized samples were taken by unit-time hand collecting (day and night times), sweeping, beating, baiting and by Winkler sacks. A total of 156 species, representing 49 genera were found, of which 98, 88 and 55 were respectively found in the Planalto, Flanco and Varzea forests. Species lists are presented and the ant community composition and species richness are compared between the three forests. By considering the nesting and foraging habits of the various species, the differences in overall community composition are related to the forest type and susceptibility to inundation of the three forests which were surveyed. The data confirm the view that tropical rain forests support an extremely diverse ant fauna and comparisons with other forested areas suggest that ant species richness declines in subtropical and temperate rain forests. Although alpha diversity is high, species turnover between forests is lower than expected, suggesting that ant species richness in this forested region is not as great as is implied in some published estimates of global arthropod diversity. [ABSTRACT FROM AUTHOR]