Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Nodulos linfoides medulares em pacientes portadores de sindrome mielodisplasicas : incidencia, caracterização morfologica, imunohistoquimica e associação com criterios clinico-laboratoriais, progressão da doença e sobrevida

Orientadores : Irene Lorand-Metze, Jose VassalloTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: Síndromes mielodisplásicas (SMD) são um grupo heterogêneo de desordens caracterizado por anormalidades na proliferação e maturação dos precursores hematopoéticos, resultando em citopenias periféricas e potencial para transformação leucêmica. Nódulos linfóides (NL) medulares são, em geral, considerados fisiológicos e relacionados à idade. Em pacientes com SMD o seu significadoclínicopermanece obscuro. Nesse estudo, a presença de NL medulares foi investigada em 206 pacientes com SMD. A idade mediana foi de 58,5 anos (15-89). Segundo a classificaçãoFAB, foram avaliados 129 AR, 29 ARSA, 31 AREB/AREB-t, 11 LMMC, 5 variantes hiperfibróticas e 1 caso inclassificável. NL foram observados em 24,8% dos casos (51/206). Em 25 casos foi possível uma análise imunohistoquímica utilizando-se os anticorpos: CD20, CD3, CD45RO e anti-bcl-2. Embora os NL apresentassem, em geral localização central (88,3%) e limites precisos, alguns exibiam posição paratrabecular (3,9%) ou margens imprecisas (13,7%). O aumento nas fibras de reticulina foi evidenciado em 51,1% dos casos. Positividade para CD20 foi detectada em 92,0% das amostras (23/25) com padrão central perinodular ou difuso. Marcação com CD3 e/ou CD45RO foi evidenciada em 48,0% dos casos (12/25). Em 15 pacientes só marcação para células B (13 casos) ou T (2 casos) foi observada e em 10 casos uma população mista de células B e T foi notada. A expressão de bcl-2 foi detectada em apenas 2 casos. A incidência de NL foi alta quando considerada a idade dos pacientes. Quando comparados os grupos com e sem NL não se observou diferença significativa com relação à idade, sexo, contagem de neutrófilos, plaquetas, subtipo FAB, progressão da doença ou sobrevida global. A presença de NL mostrou uma associação significativa com o aumento de fibras de reticulina no tecido hematopoético (P=0,01) e, ainda, com menor dosagem de hemoglobina (p=0,03). A análise multivariada mostrou que hemoglobina e subtipo FAB foram os fatores preditivos de sobrevida mais significativos. Os resultados mostraram que NL em pacientes com SMD têm características morfológicas e imunofenotípicas heterogêneas. Não se observou associação com doença linfoproliferativa. Esses agregados podem representar reatividade a uma estimulação imunológica anormal e persistente e estão, provavelmente, relacionados à alteração da arquitetura medularAbstract: Myelodysplastic syndromes (MDS) are a heterogeneous group of c10na! disorders characterised by abnormalities in proliferation and maturation of haemopoietic precursors resulting in cytopenias and a preleukaemic state. Bone marrow lYffiphoid nodules (LN) are usually considered to be a physiological feature, closelyrelated to age. In patients with MDS their clinical and biological meaning remain obscure. In the present study the presence of LN in bone marrow biopsy was investigated in 206 patients with MDS. The median age was 58.5 years (range 15-89). According to FAB classification, there were 129 RA, 29 RARS, 31 AREB/AREB-t, 11 Clv1ML,5 hyperfibrotic variants and 1 unc1assifiablecase. Single or multiple LN were present in 24.8% of the cases. Twentyfive specimens were evaluated with a panel of antibodies reactive on routinely processed, paraffin-embedded trephine biopsies: CD20, CD3, CD45RO and anti-bc1-2.Although most LN were centrally located (88.3%), well circumscribed and polYffiorphous, some were paratrabecular (3.9%) or ill defined (13.7%). An increase in reticulin fibres was observed in 51.1% of cases. CD20 positive cells were found in 23/25 (92.0%) of the cases in three distinct pattems: strong central, perinodular and faint diffuse. Positivity with CD3 and/or CD45RO was detected in 12/25 (48.0%) ofthe cases. In 15 patients only B (13 cases) or T cells (2 cases) could be detected whereas in 10 cases a mixture ofB and T cells was noted. Bc1-2 expression was positive in only 2 specimens. The incidence of LN in our MDS patients was unexpectedly high considering the median age of patients. The comparison between patients with and without LN did not reveal statistically significant differences concerning age, sex, neutrophil counts, platelets, FAB subtype, disease progression or overall survival. The presence of LN showed a relationship with an increase in reticulin fibres in the OOematopoietic tissue (p=0.01), and patients with LN exhibited lower haemoglobin values (p=0.03). Multivariate survival analysis showed tOOtOOemoglobinand FAB subtype were the most significant predictors of survival. Our results show that LN in MDS patients OOveheterogeneous characteristics. No association with IYffiphoproliferative disease and no correlation with prognosis were found. These aggregates could be an expression of reactivity to an ongoing persistent and abnormal immune stimulation and are probably related to an altered bone marrow microenvironrnentDoutoradoClinica MedicaDoutor em Clínica Médic

Splicing factor SF3B1 mutations and ring sideroblasts in myelodysplastic syndromes: a Brazilian cohort screening study

ABSTRACT Background: Myelodysplastic syndromes (MDS) comprise a group of malignant clonal hematologic disorders characterized by ineffective hematopoiesis and propensity for progression to acute myeloid leukemia. Acquired mutations in the gene encoding RNA splicing factor 3B subunit 1 (SF3B1) are highly associated with the MDS subtypes presenting ring sideroblasts, and represent a specific nosological entity. The effects of these mutations on clinical outcomes are diverse and contrasting. Methods: A cohort of 91 Brazilian MDS patients, including patients with ring sideroblasts in the bone marrow, were screened for mutations in the SF3B1 hotspots (exons 12-15) by direct Sanger sequencing. Results: SF3B1 heterozygous mutations were identified in six patients (7%), all of them with ring sideroblasts, thus confirming the association between SF3B1 mutations and myelodysplastic syndrome subtypes bearing this morphologic feature (frequency of 6/13, p-value < 0.0001). Conclusion: This is the first screening of SF3B1 mutations in a cohort of Brazilian myelodysplastic syndrome patients. Our findings confirm that mutations in this splicing gene correlate with bone marrow ringed sideroblasts