RESUMO
A hominin mandible, KNM-ER 63000, and associated vertebrate remains were recovered in 2011 from Area 40 in East Turkana, Kenya. Tephrostratigraphic and magnetostratigraphic analyses indicate that these fossils date to â¼4.3 Ma. KNM-ER 63000 consists of articulating but worn and weathered mandibular corpora, with a broken right M2 crown and alveoli preserved at other tooth positions. Despite extensive damage, KNM-ER 63000 preserves diagnostic anatomy permitting attribution to Australopithecus anamensis. It can be distinguished from Australopithecus afarensis by its strongly inclined symphyseal axis with a basally convex, 'cut-away' external surface, a lateral corpus that sweeps inferomedially beneath the canine-premolar row, and alignment of the canine alveolus with the postcanine axis. KNM-ER 63000 is distinguished from Ardipithecus ramidus by its thick mandibular corpus and large M2 crown. The functional trait structure and enamel's stable carbon isotopic composition of the Area 40 large-mammal community suggests an environment comparable to Kanapoi and other â¼4.5-4 Ma eastern African sites that would have offered Au. anamensis access to both C3 and C4 food resources. With an age of â¼4.3 Ma, KNM-ER 63000 is the oldest known specimen of Au. anamensis, predating the Kanapoi and Asa Issie samples by at least â¼100 kyr. This specimen extends the known temporal range of Au. anamensis and places it in temporal overlap with fossils of Ar. ramidus from Gona, Ethiopia. The morphology of KNM-ER 63000 indicates that the reconfigured masticatory system differentiating basal hominins from the earliest australopiths existed in the narrow temporal window, if any, separating the two. The very close temporal juxtaposition of these significant morphological and adaptive differences implies that Ar. ramidus was a relative rather than a direct phyletic ancestor of earliest Australopithecus.
Assuntos
Fósseis , Hominidae , Mandíbula , Animais , Fósseis/anatomia & histologia , Quênia , Hominidae/anatomia & histologia , Mandíbula/anatomia & histologia , Meio AmbienteRESUMO
Living hominoids are distinguished by upright torsos and versatile locomotion. It is hypothesized that these features evolved for feeding on fruit from terminal branches in forests. To investigate the evolutionary context of hominoid adaptive origins, we analyzed multiple paleoenvironmental proxies in conjunction with hominoid fossils from the Moroto II site in Uganda. The data indicate seasonally dry woodlands with the earliest evidence of abundant C4 grasses in Africa based on a confirmed age of 21 million years ago (Ma). We demonstrate that the leaf-eating hominoid Morotopithecus consumed water-stressed vegetation, and postcrania from the site indicate ape-like locomotor adaptations. These findings suggest that the origin of hominoid locomotor versatility is associated with foraging on leaves in heterogeneous, open woodlands rather than forests.
Assuntos
Adaptação Fisiológica , Evolução Biológica , Hominidae , Locomoção , Animais , Fósseis , Hominidae/fisiologia , UgandaRESUMO
Inflammatory conditions, including allergic asthma and conditions in which chronic low-grade inflammation is a risk factor, such as stress-related psychiatric disorders, are prevalent and are a significant cause of disability worldwide. Novel approaches for the prevention and treatment of these disorders are needed. One approach is the use of immunoregulatory microorganisms, such as Mycobacterium vaccae NCTC 11659, which have anti-inflammatory, immunoregulatory, and stress-resilience properties. However, little is known about how M. vaccae NCTC 11659 affects specific immune cell targets, including monocytes, which can traffic to peripheral organs and the central nervous system and differentiate into monocyte-derived macrophages that, in turn, can drive inflammation and neuroinflammation. In this study, we investigated the effects of M. vaccae NCTC 11659 and subsequent lipopolysaccharide (LPS) challenge on gene expression in human monocyte-derived macrophages. THP-1 monocytes were differentiated into macrophages, exposed to M. vaccae NCTC 11659 (0, 10, 30, 100, 300 µg/mL), then, 24 h later, challenged with LPS (0, 0.5, 2.5, 250 ng/mL), and assessed for gene expression 24 h following challenge with LPS. Exposure to M. vaccae NCTC 11659 prior to challenge with higher concentrations of LPS (250 ng/mL) polarized human monocyte-derived macrophages with decreased IL12A, IL12B, and IL23A expression relative to IL10 and TGFB1 mRNA expression. These data identify human monocyte-derived macrophages as a direct target of M. vaccae NCTC 11659 and support the development of M. vaccae NCTC 11659 as a potential intervention to prevent stress-induced inflammation and neuroinflammation implicated in the etiology and pathophysiology of inflammatory conditions and stress-related psychiatric disorders.
Assuntos
Lipopolissacarídeos , Mycobacterium , Humanos , Lipopolissacarídeos/farmacologia , Doenças Neuroinflamatórias , Inflamação , MacrófagosRESUMO
The early Pliocene site of Kanapoi (Turkana Basin, Kenya) has a large, diverse vertebrate sample that contains the earliest representatives of the hominin genus Australopithecus. Included in this sample is an impressive assemblage of fossil proboscideans, comprised of deinotheres (Deinotherium bozasi), anancine gomphotheres (Anancus ultimus), and at least three species of elephant (Loxodonta adaurora, a primitive morph of Loxodonta exoptata, and Elephas ekorensis). A single specimen from high in the sequence could plausibly belong to a primitive stage of Elephas recki. A review of dental carbon isotope analyses indicates a range of dietary habits for these taxa, from dedicated browsing (deinotheres) to mixed feeding/grazing (elephants and gomphotheres), which in early Pliocene elephants corresponds to molars with greater crown height and more plates than in late Miocene confamilials, bringing their morphology more in phase with feeding behavior than was the case in their earlier relatives. Variation in feeding preferences among Kanapoi proboscideans corresponds to evidence for habitat heterogeny, including inferred substantial presence of grasses; the occurrence of multiple megaherbivores may have contributed to the fragmentation of ecosystems, positively affecting early hominin success and aiding diversification of other ungulate groups.
Assuntos
Evolução Biológica , Biota , Dieta/veterinária , Comportamento Alimentar , Fósseis/anatomia & histologia , Mamífero Proboscídeo/classificação , Animais , Meio Ambiente , Quênia , Mamífero Proboscídeo/anatomia & histologia , DenteRESUMO
BACKGROUND: Sickle cell trait is usually an asymptomatic presentation of a patient with slightly different hemoglobin molecule makeup than normal. It is similar to a more serious disease, sickle cell disease, in which a person's hemoglobin is mutated in such a way that causes their red blood cells to easily change shape in certain environmental and internal states; this causes red blood cells to adhere to the walls and occlude the lumen of the arteries in which they travel, leading to downstream effects secondary to ischemia. Sickle cell trait does not have these ischemic effects, usually. CASE PRESENTATION: In this case, a young African American female patient presents to the clinic with severe right hip pain. Her past medical history includes sickle cell trait and asthma. She has not been symptomatic of her asthma for years and is not on therapy for it. The pain has lasted for several months and has not improved with anti-inflammatory medication. There is severe pain with internal and external rotation of the hip. The neurovascularity of the lower extremities is intact bilaterally. MRI of the femur shows stage 2 or 3 avascular necrosis of the femoral head, while X-rays of the femur are unremarkable. Non weight-bearing for several weeks was unsuccessful; shortly thereafter, the patient underwent core decompression of the right femoral head as well as starting bisphosphonates. The patient improved temporarily but regressed shortly thereafter. Her avascular necrosis worsened radiographically over the next several months. At this point, the only other option would be to do a total hip arthroplasty, but the patient may need several more throughout her lifetime due to the lifespan of the artificial replacement. CONCLUSION: There have only been scarce reports of avascular necrosis in patients with sickle cell trait. This manuscript presents such a case and includes the trials and tribulations associated with its management.
RESUMO
Our understanding of locomotor evolution in anthropoid primates has been limited to those taxa for which good postcranial fossil material and appropriate modern analogues are available. We report the results of an analysis of semicircular canal size variation in 16 fossil anthropoid species dating from the Late Eocene to the Late Miocene, and use these data to reconstruct evolutionary changes in locomotor adaptations in anthropoid primates over the last 35 Ma. Phylogenetically informed regression analyses of semicircular canal size reveal three important aspects of anthropoid locomotor evolution: (i) the earliest anthropoid primates engaged in relatively slow locomotor behaviours, suggesting that this was the basal anthropoid pattern; (ii) platyrrhines from the Miocene of South America were relatively agile compared with earlier anthropoids; and (iii) while the last common ancestor of cercopithecoids and hominoids likely was relatively slow like earlier stem catarrhines, the results suggest that the basal crown catarrhine may have been a relatively agile animal. The latter scenario would indicate that hominoids of the later Miocene secondarily derived their relatively slow locomotor repertoires.
Assuntos
Evolução Biológica , Haplorrinos/anatomia & histologia , Haplorrinos/fisiologia , Locomoção , Canais Semicirculares/anatomia & histologia , Animais , Fósseis , Análise dos Mínimos Quadrados , Filogenia , Especificidade da EspécieRESUMO
It is widely understood that Hominoidea (apes and humans) and Cercopithecoidea (Old World monkeys) have a common ancestry as Catarrhini deeply rooted in Afro-Arabia. The oldest stem Catarrhini in the fossil record are Propliopithecoidea, known from the late Eocene to early Oligocene epochs (roughly 35-30 Myr ago) of Egypt, Oman and possibly Angola. Genome-based estimates for divergence of hominoids and cercopithecoids range into the early Oligocene; however, the mid-to-late Oligocene interval from 30 to 23 Myr ago has yielded little fossil evidence documenting the morphology of the last common ancestor of hominoids and cercopithecoids, the timing of their divergence, or the relationship of early stem and crown catarrhines. Here we describe the partial cranium of a new medium-sized (about 15-20 kg) fossil catarrhine, Saadanius hijazensis, dated to 29-28 Myr ago. Comparative anatomy and cladistic analysis shows that Saadanius is an advanced stem catarrhine close to the base of the hominoid-cercopithecoid clade. Saadanius is important for assessing competing hypotheses about the ancestral morphotype for crown catarrhines, early catarrhine phylogeny and the age of hominoid-cercopithecoid divergence. Saadanius has a tubular ectotympanic but lacks synapomorphies of either group of crown Catarrhini, and we infer that the hominoid-cercopithecoid split happened later, between 29-28 and 24 Myr ago.
Assuntos
Cercopithecidae/classificação , Fósseis , Hominidae/classificação , Filogenia , Primatas/classificação , Animais , Tamanho Corporal , Cercopithecidae/anatomia & histologia , Geografia , História Antiga , Hominidae/anatomia & histologia , Humanos , Primatas/anatomia & histologia , Arábia Saudita , Crânio/anatomia & histologiaRESUMO
BACKGROUND: Protocetidae are middle Eocene (49-37 Ma) archaeocete predators ancestral to later whales. They are found in marine sedimentary rocks, but retain four legs and were not yet fully aquatic. Protocetids have been interpreted as amphibious, feeding in the sea but returning to land to rest. METHODOLOGY/PRINCIPAL FINDINGS: Two adult skeletons of a new 2.6 meter long protocetid, Maiacetus inuus, are described from the early middle Eocene Habib Rahi Formation of Pakistan. M. inuus differs from contemporary archaic whales in having a fused mandibular symphysis, distinctive astragalus bones in the ankle, and a less hind-limb dominated postcranial skeleton. One adult skeleton is female and bears the skull and partial skeleton of a single large near-term fetus. The fetal skeleton is positioned for head-first delivery, which typifies land mammals but not extant whales, evidence that birth took place on land. The fetal skeleton has permanent first molars well mineralized, which indicates precocial development at birth. Precocial development, with attendant size and mobility, were as critical for survival of a neonate at the land-sea interface in the Eocene as they are today. The second adult skeleton is the most complete known for a protocetid. The vertebral column, preserved in articulation, has 7 cervicals, 13 thoracics, 6 lumbars, 4 sacrals, and 21 caudals. All four limbs are preserved with hands and feet. This adult is 12% larger in linear dimensions than the female skeleton, on average, has canine teeth that are 20% larger, and is interpreted as male. Moderate sexual dimorphism indicates limited male-male competition during breeding, which in turn suggests little aggregation of food or shelter in the environment inhabited by protocetids. CONCLUSIONS/SIGNIFICANCE: Discovery of a near-term fetus positioned for head-first delivery provides important evidence that early protocetid whales gave birth on land. This is consistent with skeletal morphology enabling Maiacetus to support its weight on land and corroborates previous ideas that protocetids were amphibious. Specimens this complete are virtual 'Rosetta stones' providing insight into functional capabilities and life history of extinct animals that cannot be gained any other way.
Assuntos
Parto , Caracteres Sexuais , Baleias/crescimento & desenvolvimento , Envelhecimento , Animais , Feminino , Feto/anatomia & histologia , Fósseis , Geografia , Masculino , Paquistão , Paleontologia , Análise de Componente Principal , Comportamento Sexual Animal , Esqueleto , Coluna Vertebral/anatomia & histologia , Fatores de Tempo , Baleias/anatomia & histologiaRESUMO
As part of a fully integrated and comprehensive strategy to discover novel antibacterial agents, NMR- and mass spectrometry-based affinity selection screens were performed to identify compounds that bind to protein targets uniquely found in bacteria and encoded by genes essential for microbial viability. A biphenyl acid lead series emerged from an NMR-based screen with the Haemophilus influenzae protein HI0065, a member of a family of probable ATP-binding proteins found exclusively in eubacteria. The structure-activity relationships developed around the NMR-derived biphenyl acid lead were consistent with on-target antibacterial activity as the Staphylococcus aureus antibacterial activity of the series correlated extremely well with binding affinity to HI0065, while the correlation of binding affinity with B-cell cytotoxicity was relatively poor. Although further studies are needed to conclusively establish the mode of action of the biphenyl series, these compounds represent novel leads that can serve as the basis for the development of novel antibacterial agents that appear to work via an unprecedented mechanism of action. Overall, these results support the genomics-driven hypothesis that targeting bacterial essential gene products that are not present in eukaryotic cells can identify novel antibacterial agents.
Assuntos
Adenosina Trifosfatases/metabolismo , Antibacterianos/química , Proteínas de Bactérias/metabolismo , Química Farmacêutica/métodos , Haemophilus influenzae/metabolismo , Sequência de Aminoácidos , Animais , Linfócitos B/metabolismo , Desenho de Fármacos , Genoma Bacteriano , Genômica , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Dados de Sequência Molecular , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
This study provides a taphonomic analysis of the largest known sample of bone fragments collected from chimpanzee hunts. The entire sample consists of 455 bone fragments from 57 chimpanzee hunting episodes of 65 prey individuals at Ngogo, Kibale National Park, Uganda. It has low taxonomic diversity, consisting overwhelmingly of primates, especially red colobus monkeys. The age distribution of the prey remains is skewed towards pre-adults. Cranial bones are the dominant element, followed by long bones. Axial postcranial elements have low survivorship, with a complete absence of pre-caudal vertebrae. Bone is damaged in distinct ways, such as: destruction of long bone ends, typically with intact but chewed shafts; fragmentation and compression cracking of crania; and preservation of only the iliac blades of the innominates. Tooth marks are present but uncommon (4.4% of total NISP). These analyses enable us to: 1) describe and characterize consistent patterns of bone damage inflicted by chimpanzees across a much larger prey sample than has been previously studied; 2) make a preliminary comparison of the generalized chimpanzee taphonomic signature to that of leopard and eagle consumption of primates, as well as modern human consumption of small mammals; and 3) assess the utility of such samples for recognition of early hominin small mammal carnivory. We present a model that may be useful for detecting a pre-technological hominin carnivory and suggest some fossil locales at which close inspection of cercopithecoid remains for the above patterns might reveal traces of hominin hunting, though we caution that a pre-technological hominin hunted "assemblage" is not likely to be archaeologically visible.
Assuntos
Osso e Ossos , Pan troglodytes , Comportamento Predatório , Animais , Feminino , Masculino , UgandaRESUMO
We report on a late Oligocene proboscidean species from Eritrea, dated to 26.8 +/- 1.5 Mya. This "missing link" between early elephantiformes and Elephantimorpha is the oldest known nongomphothere proboscidean to probably display horizontal tooth displacement, typical of elephants [Elephantimorpha consists of Mammutida (mastodons) and Elephantida, and Elephantida includes gomphotheres, stegodons, and elephants]. Together with the newly discovered late Oligocene gomphotheres from Chilga, Ethiopia, the Eritrean taxon points to the importance of East Africa as a major area for the knowledge of the early evolution of Elephantimorpha before the faunal exchange between Eurasia and Africa.
Assuntos
Elefantes/genética , Animais , Evolução Biológica , Elefantes/classificação , Eritreia , Fósseis , Arcada Osseodentária/anatomia & histologia , Fatores de TempoRESUMO
Methionine aminopeptidase-2 (MetAP2) is a novel target for cancer therapy. As part of an effort to discover orally active reversible inhibitors of MetAP2, a series of anthranilic acid sulfonamides with micromolar affinities for human MetAP2 were identified using affinity selection by mass spectrometry (ASMS) screening. These micromolar hits were rapidly improved to nanomolar leads on the basis of insights from protein crystallography; however, the compounds displayed extensive binding to human serum albumin and had limited activity in cellular assays. Modifications based on structural information on the binding of lead compounds to both MetAP2 and domain III of albumin allowed the identification of compounds with significant improvements in both parameters, which showed good cellular activity in both proliferation and methionine processing assays.
Assuntos
Aminopeptidases/química , Antineoplásicos/síntese química , Metaloendopeptidases/química , Albumina Sérica/química , Sulfonamidas/síntese química , ortoaminobenzoatos/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Técnicas In Vitro , Espectrometria de Massas , Metionina/metabolismo , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Ratos , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , ortoaminobenzoatos/química , ortoaminobenzoatos/farmacologiaRESUMO
We have screened molecules for inhibition of MetAP2 as a novel approach toward antiangiogenesis and anticancer therapy using affinity selection/mass spectrometry (ASMS) employing MetAP2 loaded with Mn(2+) as the active site metal. After a series of anthranilic acid sulfonamides with micromolar affinities was identified, chemistry efforts were initiated. The micromolar hits were quickly improved to potent nanomolar inhibitors by chemical modifications guided by insights from X-ray crystallography.
Assuntos
Aminopeptidases/antagonistas & inibidores , Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Glicoproteínas/antagonistas & inibidores , Sulfonamidas/farmacologia , Inibidores da Angiogênese/síntese química , Inibidores da Angiogênese/química , Antineoplásicos/síntese química , Antineoplásicos/química , Sítios de Ligação , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Manganês/química , Espectrometria de Massas/métodos , Metionil Aminopeptidases , Modelos Moleculares , Estrutura Molecular , Sensibilidade e Especificidade , Estereoisomerismo , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/químicaRESUMO
Attempts to synthesize pyridoazepinone carboxylic acids such as 33 by standard methodologies resulted exclusively in unusual and unexpected rearrangement products. Seven-membered ring formation was attempted by ring expansion of a six-membered ring and by aldol ring closure. In each case, the major product resulted from rearrangement of the starting material without detection of the desired product. Ultimately, an isomeric pyridoazepinone ethyl ester was prepared; however, attempted saponification resulted in another unusual rearrangement. [reaction: see text]
RESUMO
Potent inhibitors of 7,8-dihydroneopterin aldolase (DHNA; EC 4.1.2.25) have been discovered using CrystaLEAD X-ray crystallographic high-throughput screening followed by structure-directed optimization. Screening of a 10 000 compound random library provided several low affinity leads and their corresponding X-ray crystal structures bound to the enzyme. The presence of a common structural feature in each of the leads suggested a strategy for the construction of a directed library of approximately 1000 compounds that were screened for inhibitory activity in a traditional enzyme assay. Several lead compounds with IC(50) values of about 1 microM against DHNA were identified, and crystal structures of their enzyme-bound complexes were obtained by cocrystallization. Structure-directed optimization of one of the leads thus identified afforded potent inhibitors with submicromolar IC(50) values.
Assuntos
Aldeído Liases/antagonistas & inibidores , Aldeído Liases/química , Benzoatos/química , Inibidores Enzimáticos/química , Neopterina/química , Pirimidinas/química , Triazóis/química , Benzoatos/síntese química , Sítios de Ligação , Cristalografia por Raios X , Bases de Dados Factuais , Inibidores Enzimáticos/síntese química , Guanina/análogos & derivados , Guanina/síntese química , Guanina/química , Modelos Moleculares , Estrutura Molecular , Purinas/química , Pirimidinas/síntese química , Relação Estrutura-Atividade , Triazóis/síntese químicaRESUMO
Afro-Arabian mammalian communities underwent a marked transition near the Oligocene/Miocene boundary at approximately 24 million years (Myr) ago. Although it is well documented that the endemic paenungulate taxa were replaced by migrants from the Northern Hemisphere, the timing and evolutionary dynamics of this transition have long been a mystery because faunas from about 32 to 24 Myr ago are largely unknown. Here we report a late Oligocene fossil assemblage from Ethiopia, which constrains the migration to postdate 27 Myr ago, and yields new insight into the indigenous faunal dynamics that preceded this event. The fauna is composed of large paenungulate herbivores and reveals not only which earlier taxa persisted into the late Oligocene epoch but also demonstrates that one group, the Proboscidea, underwent a marked diversification. When Eurasian immigrants entered Afro-Arabia, a pattern of winners and losers among the endemics emerged: less diverse taxa such as arsinoitheres became extinct, moderately species-rich groups such as hyracoids continued into the Miocene with reduced diversity, whereas the proboscideans successfully carried their adaptive radiation out of Afro-Arabia and across the world.
Assuntos
Biodiversidade , Fósseis , Mamíferos , Migração Animal , Animais , Arábia , Ásia , Evolução Biológica , Etiópia , Europa (Continente) , Sedimentos Geológicos , Mamíferos/anatomia & histologia , Mamíferos/classificação , Dente/anatomia & histologiaRESUMO
This study provides a taphonomic analysis of prey accumulations of crowned hawk-eagles (Stephanoaetus coronatus) from Ngogo, Kibale National Park, Uganda, collected over 37 months from below nests of two eagle pairs. Crowned hawk-eagles are powerful predators capable of killing animals much larger than themselves, and are significant predators of cercopithecoid monkeys in forest habitats throughout sub-Saharan Africa. At Ngogo, 81% of the individuals in the kill sample are monkeys. Redtail monkeys (Cercopithecus ascanius) are particularly well represented in the sample, making up 66% of monkeys identified to species. Despite an impressive killing apparatus, crowned hawk-eagles are fastidious eaters that inflict far less damage to bone than mammalian predators. Examination of skeletal material from the Ngogo kill sample reveals that crania, hindlimb elements, and scapulae survive predation better than do other bones. Crania of adults are typically complete and accompanied by mandibles, while crania of young individuals are usually dissociated from mandibles and lack basicrania and faces. Long bones are often whole or show minimal damage. Thin bones, such as crania and innominates, are marked by numerous nicks, punctures, and "can-opener" perforations. Scapular blades are heavily raked and shattered. Along with the strong preference for cercopithecoids, these distinct patterns of bone survival and damage indicate the feasibility of recognizing specific taphonomic signatures of large raptors in fossil assemblages. Berger and Clarke (1995) hypothesized that crowned hawk-eagles or similar large raptors were principally responsible for the accumulation of the late Pliocene fossil fauna from Taung, South Africa, including the type infant skull of Australopithecus africanus. The results of our study suggest that the faunal composition and type of damage to the hominid skull and other bone from Taung are consistent with the predatory activities of large raptors. More rigorous assessment of their hypothesis will require sorting the Taung fauna by locality and further detailed analysis of species composition and bone damage and survivability patterns.