RESUMO
BACKGROUND AND PURPOSE: Damage to the insula results in cardiovascular complications. In rats, activation of N-methyl-d-aspartate receptors (NMDARs) in the intermediate region of the posterior insular cortex (iIC) results in sympathoexcitation, tachycardia and arterial pressure increases. Similarly, focal experimental hemorrhage at the iIC results in a marked sympathetic-mediated increase in baseline heart rate. The dorsomedial hypothalamic region (DMH) is critical for the integration of sympathetic-mediated tachycardic responses. Here, whether responses evoked from the iIC are dependent on a synaptic relay in the DMH was evaluated. METHODS: Wistar rats were prepared for injections into the iIC and DMH. Anatomical (tracing combined with immunofluorescence) and functional experiments (cardiovascular and sympathetic recordings) were performed. RESULTS: The iIC sends dense projections to the DMH. Approximately 50% of iIC neurons projecting to the DMH express NMDARs, NR1 subunit. Blockade of glutamatergic receptors in the DMH abolishes the cardiovascular and autonomic responses evoked by the activation of NMDARs in the iIC (change in mean arterial pressure 7 ± 1 vs. 1 ± 1 mmHg after DMH blockade; change in heart rate 28 ± 3 vs. 0 ± 3 bpm after DMH blockade; change in renal sympathetic nerve activity 23% ± 1% vs. -1% ± 4% after DMH blockade). Experimental hemorrhage at the iIC resulted in a marked tachycardia (change 89 ± 14 bpm) that was attenuated by 65% ± 5% (p = 0.0009) after glutamatergic blockade at the DMH. CONCLUSIONS: The iIC-induced tachycardia is largely dependent upon a glutamatergic relay in the DMH. Our study reveals the presence of an excitatory glutamatergic pathway from the iIC to the DMH that may be involved in the cardiovascular alterations observed after insular stroke.
Assuntos
Núcleo Hipotalâmico Dorsomedial , Acidente Vascular Cerebral , Animais , Pressão Sanguínea , Frequência Cardíaca , Humanos , Hipotálamo , Ratos , Ratos Wistar , Transmissão Sináptica , Taquicardia/etiologiaRESUMO
In the original article, one of the co-authors' (Ken Khong Eng) given name has been published incorrectly. The correct given name should be Ken Khong. The original article has been corrected.
RESUMO
There has been a long-standing debate concerning the extent to which the spread of Neolithic ceramics and Malay-Polynesian languages in Island Southeast Asia (ISEA) were coupled to an agriculturally driven demic dispersal out of Taiwan 4000 years ago (4 ka). We previously addressed this question using founder analysis of mitochondrial DNA (mtDNA) control-region sequences to identify major lineage clusters most likely to have dispersed from Taiwan into ISEA, proposing that the dispersal had a relatively minor impact on the extant genetic structure of ISEA, and that the role of agriculture in the expansion of the Austronesian languages was therefore likely to have been correspondingly minor. Here we test these conclusions by sequencing whole mtDNAs from across Taiwan and ISEA, using their higher chronological precision to resolve the overall proportion that participated in the "out-of-Taiwan" mid-Holocene dispersal as opposed to earlier, postglacial expansions in the Early Holocene. We show that, in total, about 20% of mtDNA lineages in the modern ISEA pool result from the "out-of-Taiwan" dispersal, with most of the remainder signifying earlier processes, mainly due to sea-level rises after the Last Glacial Maximum. Notably, we show that every one of these founder clusters previously entered Taiwan from China, 6-7 ka, where rice-farming originated, and remained distinct from the indigenous Taiwanese population until after the subsequent dispersal into ISEA.
Assuntos
Impressão Genômica , Sudeste Asiático , DNA Mitocondrial/genética , Feminino , Efeito Fundador , Humanos , TaiwanRESUMO
There are two very different interpretations of the prehistory of Island Southeast Asia (ISEA), with genetic evidence invoked in support of both. The "out-of-Taiwan" model proposes a major Late Holocene expansion of Neolithic Austronesian speakers from Taiwan. An alternative, proposing that Late Glacial/postglacial sea-level rises triggered largely autochthonous dispersals, accounts for some otherwise enigmatic genetic patterns, but fails to explain the Austronesian language dispersal. Combining mitochondrial DNA (mtDNA), Y-chromosome and genome-wide data, we performed the most comprehensive analysis of the region to date, obtaining highly consistent results across all three systems and allowing us to reconcile the models. We infer a primarily common ancestry for Taiwan/ISEA populations established before the Neolithic, but also detected clear signals of two minor Late Holocene migrations, probably representing Neolithic input from both Mainland Southeast Asia and South China, via Taiwan. This latter may therefore have mediated the Austronesian language dispersal, implying small-scale migration and language shift rather than large-scale expansion.
Assuntos
Povo Asiático/genética , DNA Mitocondrial/genética , Genoma Humano , Sudeste Asiático , Cromossomos Humanos Y/genética , Bases de Dados Genéticas , Feminino , Estudos de Associação Genética , Loci Gênicos , Humanos , Masculino , Modelos Genéticos , Filogenia , Filogeografia , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos TestesRESUMO
Cardiovascular (CV) representation has been identified within the insular cortex (IC) and a lateralization of function previously suggested. In order to further understand the role of IC on cardiovascular control, the present study compared the CV responses evoked by stimulation of N-metil-D-aspartate (NMDA) receptors in the right and left posterior IC at different rostrocaudal levels. Intracortical microinjections of NMDA were performed into the IC of male Wistar rats anaesthetized with urethane (1.4 g/kg) prepared for blood pressure, heart rate and renal sympathetic nerve activity. Gene expression of NMDA receptor subunits NR2A and NR2B in the IC was confirmed by RT-PCR. Immunofluorescence for the NMDA receptor NR1 subunit was demonstrated in the IC (coordinates anteroposterior (AP) +1.5, 0.0 and -1.5 mm). A cardiac sympathoinhibitory site was identified, more rostrally located than identified in previous studies. A site of sympathoexcitatory cardiac control was identified more caudal to this region in agreement with earlier work. Under the experimental conditions, no lateralization of cardiovascular function was identified with chemical stimulation eliciting the same responses from either left or right insular cortices. No tonic role of the insula on cardiovascular control was identified with the use of the NMDA antagonist, AP-5. Peri-insular microinjection of NMDA was without cardiovascular effect indicating the specificity of the insula as a cardiovascular regulatory site. The current study reveals a functional topography for autonomic cardiovascular control along the rostrocaudal axis of the posterior IC.
Assuntos
Fenômenos Fisiológicos Cardiovasculares , Córtex Cerebral/fisiologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Antagonistas de Receptores Adrenérgicos beta 1/farmacologia , Animais , Pressão Arterial/efeitos dos fármacos , Sistema Nervoso Autônomo/efeitos dos fármacos , Sistema Nervoso Autônomo/fisiologia , Sistema Nervoso Autônomo/fisiopatologia , Bradicardia/induzido quimicamente , Bradicardia/fisiopatologia , Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Regulação da Expressão Gênica/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Rim/inervação , Masculino , Antagonistas Muscarínicos/farmacologia , N-Metilaspartato/farmacologia , Ratos , Ratos Wistar , Receptores de Glutamato/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Taquicardia/induzido quimicamente , Taquicardia/fisiopatologiaRESUMO
The "Polynesian motif" defines a lineage of human mtDNA that is restricted to Austronesian-speaking populations and is almost fixed in Polynesians. It is widely thought to support a rapid dispersal of maternal lineages from Taiwan ~4000 years ago (4 ka), but the chronological resolution of existing control-region data is poor, and an East Indonesian origin has also been proposed. By analyzing 157 complete mtDNA genomes, we show that the motif itself most likely originated >6 ka in the vicinity of the Bismarck Archipelago, and its immediate ancestor is >8 ka old and virtually restricted to Near Oceania. This indicates that Polynesian maternal lineages from Island Southeast Asia gained a foothold in Near Oceania much earlier than dispersal from either Taiwan or Indonesia 3-4 ka would predict. However, we find evidence in minor lineages for more recent two-way maternal gene flow between Island Southeast Asia and Near Oceania, likely reflecting movements along a "voyaging corridor" between them, as previously proposed on archaeological grounds. Small-scale mid-Holocene movements from Island Southeast Asia likely transmitted Austronesian languages to the long-established Southeast Asian colonies in the Bismarcks carrying the Polynesian motif, perhaps also providing the impetus for the expansion into Polynesia.
Assuntos
DNA Mitocondrial/genética , Fluxo Gênico , Genética Populacional , Haplótipos/genética , Havaiano Nativo ou Outro Ilhéu do Pacífico/genética , Polimorfismo Genético/genética , Sudeste Asiático , Humanos , Indonésia , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Polinésia , TaiwanAssuntos
Cabeça/anatomia & histologia , Obstetrícia/métodos , Pelve/anatomia & histologia , Feminino , Humanos , Masculino , GravidezRESUMO
Traumatic brain injury (TBI) is associated with the severest casualties from Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF). From October 1, 2008, the U.S. Army Medical Department initiated a transcranial Doppler (TCD) ultrasound service for TBI; included patients were retrospectively evaluated for TCD-determined incidence of post-traumatic cerebral vasospasm and intracranial hypertension after wartime TBI. Ninety patients were investigated with daily TCD studies and a comprehensive TCD protocol, and published diagnostic criteria for vasospasm and increased intracranial pressure (ICP) were applied. TCD signs of mild, moderate, and severe vasospasms were observed in 37%, 22%, and 12% of patients, respectively. TCD signs of intracranial hypertension were recorded in 62.2%; 5 patients (4.5%) underwent transluminal angioplasty for post-traumatic clinical vasospasm treatment, and 16 (14.4%) had cranioplasty. These findings demonstrate that cerebral arterial spasm and intracranial hypertension are frequent and significant complications of combat TBI; therefore, daily TCD monitoring is recommended for their recognition and subsequent management.
Assuntos
Lesões Encefálicas/complicações , Circulação Cerebrovascular/fisiologia , Hemodinâmica/fisiologia , Hipertensão Intracraniana/etiologia , Vasoespasmo Intracraniano/etiologia , Adolescente , Adulto , Lesões Encefálicas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índices de Gravidade do Trauma , Ultrassonografia Doppler Transcraniana , Vasoespasmo Intracraniano/diagnóstico por imagem , Adulto JovemRESUMO
There is currently no calibration available for the whole human mtDNA genome, incorporating both coding and control regions. Furthermore, as several authors have pointed out recently, linear molecular clocks that incorporate selectable characters are in any case problematic. We here confirm a modest effect of purifying selection on the mtDNA coding region and propose an improved molecular clock for dating human mtDNA, based on a worldwide phylogeny of > 2000 complete mtDNA genomes and calibrating against recent evidence for the divergence time of humans and chimpanzees. We focus on a time-dependent mutation rate based on the entire mtDNA genome and supported by a neutral clock based on synonymous mutations alone. We show that the corrected rate is further corroborated by archaeological dating for the settlement of the Canary Islands and Remote Oceania and also, given certain phylogeographic assumptions, by the timing of the first modern human settlement of Europe and resettlement after the Last Glacial Maximum. The corrected rate yields an age of modern human expansion in the Americas at approximately 15 kya that-unlike the uncorrected clock-matches the archaeological evidence, but continues to indicate an out-of-Africa dispersal at around 55-70 kya, 5-20 ky before any clear archaeological record, suggesting the need for archaeological research efforts focusing on this time window. We also present improved rates for the mtDNA control region, and the first comprehensive estimates of positional mutation rates for human mtDNA, which are essential for defining mutation models in phylogenetic analyses.
Assuntos
DNA Mitocondrial/genética , Mitocôndrias/genética , Mutação/genética , Seleção Genética , Evolução Molecular , Variação Genética , Genoma Humano , Humanos , Modelos Genéticos , FilogeniaRESUMO
BACKGROUND: The incidence of neurologic injury after proximal humerus fractures is variable, ranging from 6.2% to as much as 67%. However, it is unclear what factors might contribute to these injuries or whether they can be prevented by intraoperative nerve monitoring. QUESTIONS/PURPOSES: Therefore, using intraoperative nerve monitoring, we assessed the incidence, pattern of nerve involvement, and predisposing factors for nerve injury before and during shoulder fracture fixation. PATIENTS AND METHODS: We used continuous intraoperative monitoring of the brachial plexus in 37 patients undergoing open operative treatment of proximal humerus fractures. Impending intraoperative compromise of nerve function was signaled by sustained neurotonic EMG activity or greater than 50% amplitude attenuation of transcranial electrical motor evoked potentials (MEPs) (or both). When a nerve alert occurred, current surgical activity and arm and retractor position were recorded and adjustments were made to relieve tension. RESULTS: The intraoperative affected nerves included axillary (46%), combined (mixed plexopathy) (23%), radial (23%), musculocutaneous (4%), and ulnar (4%). Postoperatively, three patients had transient nerve palsies, which fully resolved within 3 weeks of surgery. Low body mass index (BMI) (22.7 ± 2.8), history of cervical spine disease, diabetes mellitus, and delay in surgical treatment (14 ± 2.9 days from time of injury) were associated with an increased incidence of nerve dysfunction. CONCLUSIONS: Our observations suggest transcranial electrical MEPs are sensitive indicators of impending iatrogenic injury to the brachial plexus or peripheral nerves (or both) during open operative treatment of proximal humerus fractures. The use of intraoperative nerve monitoring during these procedures may be considered for the prevention of nerve injury, particularly in patients with underlying cervical spine disease, low BMI, diabetes mellitus, and/or delay in surgical treatment greater than approximately 14 days. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Assuntos
Plexo Braquial/lesões , Eletromiografia , Potencial Evocado Motor , Fixação de Fratura/efeitos adversos , Monitorização Intraoperatória/métodos , Traumatismos dos Nervos Periféricos , Fraturas do Ombro/cirurgia , Traumatismos do Sistema Nervoso/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Doença Iatrogênica , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fraturas do Ombro/fisiopatologia , Traumatismos do Sistema Nervoso/diagnóstico , Traumatismos do Sistema Nervoso/etiologia , Traumatismos do Sistema Nervoso/fisiopatologiaRESUMO
Damage to the insular cortex (IC) results in serious cardiovascular consequences and evidence indicates that the characteristics are lateralized. However, a study comparing the effects of focal experimental hemorrhage between IC sides was never performed. We compared the cardiovascular, autonomic and cardiac changes produced by focal experimental hemorrhage (ICH) into the left (L) or right (R) IC. Wistar rats were submitted to microinjection of autologous blood (ICH) or saline (n = 6 each side/group) into the R or L IC. Blood pressure (BP), heart rate (HR) and renal sympathetic activity (RSNA) were recorded. Measurements of calcium transient and sarcoplasmic Ca2+ ATPase expression in cardiomyocytes were performed. ICH increased baseline HR (Δ:L-ICH 452 ± 13 vs saline 407 ± 11 bpm; R-ICH 450 ± 7 vs saline 406 ± 8 bpm, P < 0.05) without changing BP. HR was restored to baseline levels after i.v. atenolol. Strikingly, ICH rats presented a reduced baseline RSNA (Δ:L-ICH 122 ± 4 vs saline 148 ± 11 spikes/s; R-ICH 112 ± 5 vs saline 148 ± 7 spikes/s, P < 0.05). After 24 h of ICH we observed a marked increase in cardiac ectopies and this number was greater after ICH R-IC. Heart weight, calcium amplitude and SERCA expression were reduced only in ICH R-IC. Focal stroke into IC can alter the cardiac and renal autonomic control. Damage to the R-IC produces a greater number of arrhythmias and changes in calcium dynamics in cardiac cells indicating that the cardiovascular consequences are hemisphere-dependent. These findings confirm asymmetry for cardiac autonomic control at the IC and help to understand the cardiac and renal implications observed after specific side cortical damage.
Assuntos
Doenças do Sistema Nervoso Autônomo/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Córtex Cerebral/fisiopatologia , Acidente Vascular Cerebral Hemorrágico/fisiopatologia , Nefropatias/fisiopatologia , Animais , Doenças do Sistema Nervoso Autônomo/etiologia , Doenças Cardiovasculares/etiologia , Córtex Cerebral/patologia , Modelos Animais de Doenças , Acidente Vascular Cerebral Hemorrágico/complicações , Acidente Vascular Cerebral Hemorrágico/patologia , Nefropatias/etiologia , Masculino , Ratos , Ratos WistarRESUMO
Modern humans have been living in Island Southeast Asia (ISEA) for at least 50,000 years. Largely because of the influence of linguistic studies, however, which have a shallow time depth, the attention of archaeologists and geneticists has usually been focused on the last 6,000 years--in particular, on a proposed Neolithic dispersal from China and Taiwan. Here we use complete mitochondrial DNA (mtDNA) genome sequencing to spotlight some earlier processes that clearly had a major role in the demographic history of the region but have hitherto been unrecognized. We show that haplogroup E, an important component of mtDNA diversity in the region, evolved in situ over the last 35,000 years and expanded dramatically throughout ISEA around the beginning of the Holocene, at the time when the ancient continent of Sundaland was being broken up into the present-day archipelago by rising sea levels. It reached Taiwan and Near Oceania more recently, within the last approximately 8,000 years. This suggests that global warming and sea-level rises at the end of the Ice Age, 15,000-7,000 years ago, were the main forces shaping modern human diversity in the region.
Assuntos
DNA Mitocondrial/genética , Emigração e Imigração , Efeito Estufa , Camada de Gelo , Sudeste Asiático , Sequência de Bases , DNA Mitocondrial/classificação , DNA Mitocondrial/história , Emigração e Imigração/história , Variação Genética , Haplótipos , História Antiga , Humanos , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNARESUMO
Natural killer (NK) cell functions are modulated by polymorphic killer cell immunoglobulin-like receptors (KIR). Among 13 human KIR genes, which vary by presence and copy number, KIR3DL3 is ubiquitously present in every individual across diverse populations. No ligand or function is known for KIR3DL3, but limited knowledge of expression suggests involvement in reproduction, likely during placentation. With 157 human alleles, KIR3DL3 is also highly polymorphic and we show heterozygosity exceeds that of HLA-B in many populations. The external domains of catarrhine primate KIR3DL3 evolved as a conserved lineage distinct from other KIR. Accordingly, and in contrast to other KIR, we show the focus of natural selection does not correspond exclusively to known ligand binding sites. Instead, a strong signal for diversifying selection occurs in the D1 Ig domain at a site involved in receptor aggregation, which we show is polymorphic in humans worldwide, suggesting differential ability for receptor aggregation. Meanwhile in the cytoplasmic tail, the first of two inhibitory tyrosine motifs (ITIM) is conserved, whereas independent genomic events have mutated the second ITIM of KIR3DL3 alleles in all great apes. Together, these findings suggest that KIR3DL3 binds a conserved ligand, and a function requiring both receptor aggregation and inhibitory signal attenuation. In this model KIR3DL3 resembles other NK cell inhibitory receptors having only one ITIM, which interact with bivalent downstream signaling proteins through dimerization. Due to the extensive conservation across species, selection, and other unusual properties, we consider elucidating the ligand and function of KIR3DL3 to be a pressing question.
Assuntos
Heterozigoto , Primatas/genética , Primatas/metabolismo , Receptores KIR/genética , Receptores KIR/metabolismo , Transdução de Sinais , Sequência de Aminoácidos , Animais , Evolução Biológica , Hominidae , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Modelos Moleculares , Filogeografia , Primatas/imunologia , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Receptores KIR/química , Seleção Genética , Relação Estrutura-AtividadeRESUMO
BACKGROUND: It is not known whether progression of aortic arch (AA) atheroma is associated with vascular events in patients with stroke or transient ischemic attack (TIA). METHODS AND RESULTS: AA atheroma was detected on baseline transesophageal echocardiogram in 167 consecutive patients who had prevalent stroke or TIA. Of these, 125 consented to a follow-up transesophageal echocardiogram at 12 months. Adequate paired AA images were obtained in 117 (78 with strokes, 39 with TIAs), which allowed detailed measurements of plaques. On admission for their index stroke or TIA, patients were assessed for stroke risk factors, stroke subtypes, baseline AA plaque characteristics, and laboratory parameters. Progression of AA atheroma was observed in 33 patients (28%) on 12-month follow-up transesophageal echocardiogram. It was determined that the progression group had significantly higher adjusted homocysteine levels (P<0.0001) and neutrophil counts (P<0.0001) than the no-progression group. These patients were followed up for a median of 1.7 years from the index stroke/TIA (range 0.5 to 4.5 years) for vascular events including stroke, TIA, myocardial infarction, and death due to vascular causes. Kaplan-Meier curves showed fewer patients with AA atheroma progression remained free of the composite vascular end point (49% compared with 89% in the no-progression group; P<0.0001). AA atheroma progression was associated with composite vascular events (hazard ratio 5.8, 95% confidence interval 2.3 to 14.5, P=0.0002) after adjustment for a propensity score based on confounders. CONCLUSIONS: In this preliminary study of stroke/TIA patients with AA atheroma on transesophageal echocardiogram, AA atheroma progression was associated with recurrent vascular events.
Assuntos
Aorta Torácica/patologia , Aterosclerose/epidemiologia , Aterosclerose/patologia , Ataque Isquêmico Transitório/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Idoso , Aterosclerose/diagnóstico por imagem , Progressão da Doença , Intervalo Livre de Doença , Ecocardiografia Transesofagiana , Feminino , Seguimentos , Homocisteína/sangue , Humanos , Hipertensão/epidemiologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prevalência , Recidiva , Fatores de RiscoRESUMO
Interoception refers to the process by which the nervous system senses, interprets, and integrates signals originating from within the body, providing a moment-by-moment mapping of the body's internal landscape across conscious and unconscious levels. Interoceptive signaling has been considered a component process of reflexes, urges, feelings, drives, adaptive responses, and cognitive and emotional experiences, highlighting its contributions to the maintenance of homeostatic functioning, body regulation, and survival. Dysfunction of interoception is increasingly recognized as an important component of different mental health conditions, including anxiety disorders, mood disorders, eating disorders, addictive disorders, and somatic symptom disorders. However, a number of conceptual and methodological challenges have made it difficult for interoceptive constructs to be broadly applied in mental health research and treatment settings. In November 2016, the Laureate Institute for Brain Research organized the first Interoception Summit, a gathering of interoception experts from around the world, with the goal of accelerating progress in understanding the role of interoception in mental health. The discussions at the meeting were organized around four themes: interoceptive assessment, interoceptive integration, interoceptive psychopathology, and the generation of a roadmap that could serve as a guide for future endeavors. This review article presents an overview of the emerging consensus generated by the meeting.
Assuntos
Conscientização/fisiologia , Cognição/fisiologia , Emoções/fisiologia , Interocepção/fisiologia , Saúde Mental , Encéfalo/fisiologia , HumanosRESUMO
Recent genomic analyses show that the earliest peoples reaching Remote Oceania-associated with Austronesian-speaking Lapita culture-were almost completely East Asian, without detectable Papuan ancestry. However, Papuan-related genetic ancestry is found across present-day Pacific populations, indicating that peoples from Near Oceania have played a significant, but largely unknown, ancestral role. Here, new genome-wide data from 19 ancient South Pacific individuals provide direct evidence of a so-far undescribed Papuan expansion into Remote Oceania starting ~2,500 yr BP, far earlier than previously estimated and supporting a model from historical linguistics. New genome-wide data from 27 contemporary ni-Vanuatu demonstrate a subsequent and almost complete replacement of Lapita-Austronesian by Near Oceanian ancestry. Despite this massive demographic change, incoming Papuan languages did not replace Austronesian languages. Population replacement with language continuity is extremely rare-if not unprecedented-in human history. Our analyses show that rather than one large-scale event, the process was incremental and complex, with repeated migrations and sex-biased admixture with peoples from the Bismarck Archipelago.
Assuntos
Idioma , Dinâmica Populacional , DNA Antigo/análise , Genoma Humano , Humanos , OceaniaRESUMO
Ancient DNA from Vanuatu and Tonga dating to about 2,900-2,600 years ago (before present, BP) has revealed that the "First Remote Oceanians" associated with the Lapita archaeological culture were directly descended from the population that, beginning around 5000 BP, spread Austronesian languages from Taiwan to the Philippines, western Melanesia, and eventually Remote Oceania. Thus, ancestors of the First Remote Oceanians must have passed by the Papuan-ancestry populations they encountered in New Guinea, the Bismarck Archipelago, and the Solomon Islands with minimal admixture [1]. However, all present-day populations in Near and Remote Oceania harbor >25% Papuan ancestry, implying that additional eastward migration must have occurred. We generated genome-wide data for 14 ancient individuals from Efate and Epi Islands in Vanuatu from 2900-150 BP, as well as 185 present-day individuals from 18 islands. We find that people of almost entirely Papuan ancestry arrived in Vanuatu by around 2300 BP, most likely reflecting migrations a few hundred years earlier at the end of the Lapita period, when there is also evidence of changes in skeletal morphology and cessation of long-distance trade between Near and Remote Oceania [2, 3]. Papuan ancestry was subsequently diluted through admixture but remains at least 80%-90% in most islands. Through a fine-grained analysis of ancestry profiles, we show that the Papuan ancestry in Vanuatu derives from the Bismarck Archipelago rather than the geographically closer Solomon Islands. However, the Papuan ancestry in Polynesia-the most remote Pacific islands-derives from different sources, documenting a third stream of migration from Near to Remote Oceania.
Assuntos
DNA Antigo/análise , Genética Populacional , Genoma Humano , Migração Humana/estatística & dados numéricos , Havaiano Nativo ou Outro Ilhéu do Pacífico/genética , Dinâmica Populacional , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Oceania , FilogeniaRESUMO
The goals of the KIR component of the 17th International HLA and Immunogenetics Workshop (IHIW) were to encourage and educate researchers to begin analyzing KIR at allelic resolution, and to survey the nature and extent of KIR allelic diversity across human populations. To represent worldwide diversity, we analyzed 1269 individuals from ten populations, focusing on the most polymorphic KIR genes, which express receptors having three immunoglobulin (Ig)-like domains (KIR3DL1/S1, KIR3DL2 and KIR3DL3). We identified 13 novel alleles of KIR3DL1/S1, 13 of KIR3DL2 and 18 of KIR3DL3. Previously identified alleles, corresponding to 33 alleles of KIR3DL1/S1, 38 of KIR3DL2, and 43 of KIR3DL3, represented over 90% of the observed allele frequencies for these genes. In total we observed 37 KIR3DL1/S1 allotypes, 40 for KIR3DL2 and 44 for KIR3DL3. As KIR allotype diversity can affect NK cell function, this demonstrates potential for high functional diversity worldwide. Allelic variation further diversifies KIR haplotypes. We determined KIR3DL3â¯â¼â¯KIR3DL1/S1â¯â¼â¯KIR3DL2 haplotypes from five of the studied populations, and observed multiple population-specific haplotypes in each. This included 234 distinct haplotypes in European Americans, 191 in Ugandans, 35 in Papuans, 95 in Egyptians and 86 in Spanish populations. For another 35 populations, encompassing 642,105 individuals we focused on KIR3DL2 and identified another 375 novel alleles, with approximately half of them observed in more than one individual. The KIR allelic level data gathered from this project represents the most comprehensive summary of global KIR allelic diversity to date, and continued analysis will improve understanding of KIR allelic polymorphism in global populations. Further, the wealth of new data gathered in the course of this workshop component highlights the value of collaborative, community-based efforts in immunogenetics research, exemplified by the IHIW.
Assuntos
Antígenos HLA/genética , Imunogenética/métodos , Família Multigênica , Receptores KIR/genética , Frequência do Gene , Genética Populacional/métodos , Genótipo , Haplótipos , Humanos , Isoformas de Proteínas/genética , Análise de Sequência de DNARESUMO
BACKGROUND AND PURPOSE: Leukocyte count is an independent predictor of stroke. We investigated the association between leukocyte count and progression of aortic atheroma over 12 months in stroke/transient ischemic attack (TIA) patients. METHODS: Consecutive ischemic stroke and transient ischemic attack patients underwent 12-month sequential transesophageal echocardiography and were assessed for total and differential leukocyte counts on admission. Paired aortic plaque images were assessed for several parameters, including changes in grade, intimal-medial thickness (IMT), and cross-sectional area. Multivariate linear and logistic regressions were used to calculate the effect of leukocyte count on the change in aortic atheromas over 12 months. RESULTS: Of the 115 participants (mean+/-SD age, 64.6+/-11.9 years; 53.1% men; 73.4% white, 24.2% black, and 2.3% Asian), 45 (35%) showed clinically significant progression of aortic atheromas (maximal change in IMT >0.70 mm over 12 months). The mean admission leukocyte count was higher in the progression group compared with the no-progression group (8.6+/-2.2 vs 7.3+/-2.2 x 10(9)/L respectively, P=0.002). Each unit increase in leukocyte count was associated with a 0.26-mm increase in aortic arch IMT over 12 months (P=0.006). After adjustment for other atherosclerosis risk factors, the relation persisted (mean increase in aortic arch IMT per unit increase in leukocyte count=0.27 mm, P=0.007). Each unit increase in leukocyte count was associated with an increased risk of significant progression of aortic atheromas (adjusted odds ratio=1.33; 95% CI, 1.09 to 1.61). CONCLUSIONS: In stroke/transient ischemic attack patients, leukocyte count is independently associated with the progression of aortic atheroma over 12 months (>0.70 mm), which is associated with cardiovascular risk.
Assuntos
Doenças da Aorta/epidemiologia , Doenças da Aorta/imunologia , Aterosclerose/epidemiologia , Aterosclerose/imunologia , Inflamação/imunologia , Acidente Vascular Cerebral/epidemiologia , Idoso , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/imunologia , Aorta Torácica/patologia , Doenças da Aorta/diagnóstico por imagem , Aterosclerose/diagnóstico por imagem , Biomarcadores/análise , Estudos de Coortes , Comorbidade , Progressão da Doença , Feminino , Humanos , Inflamação/diagnóstico , Inflamação/fisiopatologia , Ataque Isquêmico Transitório/diagnóstico por imagem , Ataque Isquêmico Transitório/epidemiologia , Ataque Isquêmico Transitório/imunologia , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , UltrassonografiaRESUMO
This review comments on and summarizes five expert presentations and reports made at a meeting hosted by the World Health Organization (WHO) in Lyon, France, 12-14 June 2006, related to iron and folate supplementation and their interactions with infection. The meeting was called because of the mortality implications of the Pemba iron study and the possible need to change WHO policy as soon as possible. Six tabled presentations were reviewed. A majority of these expert reviews regarded the Pemba study as indicating a specific adverse interaction between iron supplementation and malaria. A majority regarded such an effect as already reviewed, demonstrated, and predicted in existing literature published prior to the Pemba study. A majority concluded that there was a risk of malarial morbidity associated with oral iron supplementation. A majority made recommendations for change, indicating either that the 1998 WHO/UNICEF recommendation for iron supplementation in malarious areas should be suspended pending further research or that it should be stopped. A majority felt that folate supplementation was a less likely cause of the Pemba result; two mentioned the interference of oral folate with antifolate antimalarials; a majority suggested suspension of folic acid supplementation to children in malarious areas. Only one presentation argued for net population benefits of folate and none for iron.