RESUMO
Beta-thalassemia (ß-thalassemia) is a hematologic genetic condition that causes microcytic anemia due to defective synthesis of the hemoglobin beta chain. As a hypochromic microcytic anemia that is commonly associated with symptoms such as fatigue and pallor when identified in adulthood, ß-thalassemia may be commonly underdiagnosed or misdiagnosed as iron deficiency anemia. This study presents a case of a patient with ß-thalassemia who was initially misdiagnosed with treatment-resistant iron deficiency anemia. Here, we present the case of a 66-year-old male of Mediterranean descent with a history of military service who presented with persistent fatigue. He had a past medical history of hypertension, diabetes mellitus type 2, sleep apnea, and iron deficiency anemia. Despite undergoing unnecessarily prolonged iron supplementation for suspected iron deficiency anemia, the patient's complete blood count and peripheral blood smear continued to identify hypochromic microcytic anemia. Ultimately, hemoglobin electrophoresis was performed, and mutations were identified in the hemoglobin beta chain consistent with ß-thalassemia minor. Due to its rarity and wide variation in presentation, ß-thalassemia may be frequently misdiagnosed. ß-thalassemia is a spectrum of disorders ranging from ß-thalassemia minor, which may be asymptomatic and incidentally discovered in adulthood, to ß-thalassemia major, which may include bone marrow deformities from extramedullary hematopoiesis and require frequent blood transfusions to sustain life. Therefore, patients who present with symptoms of ß-thalassemia minor may not be identified until later in life after undergoing decades of ineffective treatment. ß-thalassemia is a multifactorial disease with a variety of clinical presentations that can easily be misdiagnosed as other types of anemia. This case highlights the importance of performing thorough laboratory testing and casting a wide net of differential diagnoses when evaluating patients with treatment-resistant anemia. This case calls for further research on the genetic contributions to ß-thalassemia as well as improved ways to identify this disorder, particularly in patients who may not have a severe form that is easily diagnosed in early childhood.
RESUMO
The colonization of Eurasia by early humans is a key event after their spread out of Africa, but the nature, timing and ecological context of the earliest human occupation of northwest Europe is uncertain and has been the subject of intense debate. The southern Caucasus was occupied about 1.8 million years (Myr) ago, whereas human remains from Atapuerca-TD6, Spain (more than 780 kyr ago) and Ceprano, Italy (about 800 kyr ago) show that early Homo had dispersed to the Mediterranean hinterland before the Brunhes-Matuyama magnetic polarity reversal (780 kyr ago). Until now, the earliest uncontested artefacts from northern Europe were much younger, suggesting that humans were unable to colonize northern latitudes until about 500 kyr ago. Here we report flint artefacts from the Cromer Forest-bed Formation at Pakefield (52 degrees N), Suffolk, UK, from an interglacial sequence yielding a diverse range of plant and animal fossils. Event and lithostratigraphy, palaeomagnetism, amino acid geochronology and biostratigraphy indicate that the artefacts date to the early part of the Brunhes Chron (about 700 kyr ago) and thus represent the earliest unequivocal evidence for human presence north of the Alps.
Assuntos
Atividades Humanas/história , Animais , Arqueologia , Clima , Europa (Continente)/etnologia , Fósseis , Sedimentos Geológicos/química , História Antiga , Humanos , Insetos/fisiologia , Mamíferos/fisiologia , Chuva , Estações do Ano , Temperatura , Fatores de TempoRESUMO
Understanding extinction events requires an unbiased record of the chronology and ecology of victims and survivors. The rhinoceros Elasmotherium sibiricum, known as the 'Siberian unicorn', was believed to have gone extinct around 200,000 years ago-well before the late Quaternary megafaunal extinction event. However, no absolute dating, genetic analysis or quantitative ecological assessment of this species has been undertaken. Here, we show, by accelerator mass spectrometry radiocarbon dating of 23 individuals, including cross-validation by compound-specific analysis, that E. sibiricum survived in Eastern Europe and Central Asia until at least 39,000 years ago, corroborating a wave of megafaunal turnover before the Last Glacial Maximum in Eurasia, in addition to the better-known late-glacial event. Stable isotope data indicate a dry steppe niche for E. sibiricum and, together with morphology, a highly specialized diet that probably contributed to its extinction. We further demonstrate, with DNA sequencing data, a very deep phylogenetic split between the subfamilies Elasmotheriinae and Rhinocerotinae that includes all the living rhinoceroses, settling a debate based on fossil evidence and confirming that the two lineages had diverged by the Eocene. As the last surviving member of the Elasmotheriinae, the demise of the 'Siberian unicorn' marked the extinction of this subfamily.
Assuntos
Extinção Biológica , Perissodáctilos , Animais , Osso e Ossos/química , Isótopos de Carbono/análise , DNA/análise , Evolução Molecular , Isótopos de Nitrogênio/análise , Perissodáctilos/genética , FilogeniaRESUMO
Whereas fossil evidence indicates extensive treeless vegetation and diverse grazing megafauna in Europe and northern Asia during the last glacial, experiments combining vegetation models and climate models have to-date simulated widespread persistence of trees. Resolving this conflict is key to understanding both last glacial ecosystems and extinction of most of the mega-herbivores. Using a dynamic vegetation model (DVM) we explored the implications of the differing climatic conditions generated by a general circulation model (GCM) in "normal" and "hosing" experiments. Whilst the former approximate interstadial conditions, the latter, designed to mimic Heinrich Events, approximate stadial conditions. The "hosing" experiments gave simulated European vegetation much closer in composition to that inferred from fossil evidence than did the "normal" experiments. Given the short duration of interstadials, and the rate at which forest cover expanded during the late-glacial and early Holocene, our results demonstrate the importance of millennial variability in determining the character of last glacial ecosystems.