Island Biogeography Reveals the Deep History of SIV Worobey, Michael; Telfer, Paul; Souquière, Sandrine ...
Science (American Association for the Advancement of Science),
09/2010, Letnik:
329, Številka:
5998
Journal Article
Recenzirano
Simian immunodeficiency virus (SIV) lineages have been identified that are endemic to Bioko Island. The time the island formed offers a geological time scale calibration point for dating the most ...recent common ancestor of SIV. The Bioko viruses cover the whole range of SIV genetic diversity, and each Bioko SIV clade is most closely related to viruses circulating in hosts of the same genus on the African mainland rather than to SIVs of other Bioko species. Our phylogeographic approach establishes that SIV is ancient and at least 32,000 years old. Our conservative calibration point and analyses of gene sequence saturation and dating bias suggest it may be much older.
Haemoglobin E (HbE) β-thalassaemia causes approximately 50% of all severe thalassaemia worldwide; equating to around 30,000 births per year. HbE β-thalassaemia is due to a point mutation in codon 26 ...of the human HBB gene on one allele (GAG; glutamatic acid → AAG; lysine, E26K), and any mutation causing severe β-thalassaemia on the other. When inherited together in compound heterozygosity these mutations can cause a severe thalassaemic phenotype. However, if only one allele is mutated individuals are carriers for the respective mutation and have an asymptomatic phenotype (β-thalassaemia trait). Here we describe a base editing strategy which corrects the HbE mutation either to wildtype (WT) or a normal variant haemoglobin (E26G) known as Hb Aubenas and thereby recreates the asymptomatic trait phenotype. We have achieved editing efficiencies in excess of 90% in primary human CD34 + cells. We demonstrate editing of long-term repopulating haematopoietic stem cells (LT-HSCs) using serial xenotransplantation in NSG mice. We have profiled the off-target effects using a combination of circularization for in vitro reporting of cleavage effects by sequencing (CIRCLE-seq) and deep targeted capture and have developed machine-learning based methods to predict functional effects of candidate off-target mutations.
Thalassaemia, a hereditary haemoglobin disorder, is a major public health concern in some parts of the world. Although Bangladesh is in the world's thalassaemia belt, the information on this disease ...is scarce. Additionally, the awareness of this life threatening, but potentially preventable disease is surprisingly poor. However, mass awareness is pivotal for the development of an effective preventive strategy. In this context, the understanding of parental perspectives is essential to grasp the magnitude of the problem. Therefore, this study aimed to investigate the parental knowledge gaps and perceptions regarding thalassemia, the barriers confronted by the parents for caring for their thalassaemic children and their attitude to prenatal screening and prenatal diagnosis.
This cross-sectional study was conducted between January 2018 and December 2018 at a dedicated thalassemia hospital located in Dhaka. A structured questionnaire was used for face-to-face interviews with parents of thalassaemic children. Descriptive statistics were used to analyse data.
Of 365 respondents, nearly all respondents (97%) had not heard about the term, 'thalassemia' before the disease was diagnosed in their children; all (100%) were unscreened for carrier status prior to marriage. Mean knowledge scores were significantly higher in respondents with higher income and education. Most respondents (~ 91%) had a guilty feeling for not undergoing premarital screening. Only around 36% of them had heard about prenatal diagnosis. Approximately 25% participants would consider prenatal diagnosis in a future pregnancy, while 70% of them were unsure and only ~ 5% would decline prenatal diagnosis. Only 9.3% mothers had prenatal diagnosis in a previous pregnancy. Nearly 80% of the parents faced difficulty for obtaining blood donors regularly and a similar proportion (~ 81%) of them did not receive support from any organized blood clubs. More than 40% of the parents reported they felt socially stigmatized.
This study suggests poor parental knowledge regarding thalassaemia including prenatal diagnosis and the challenges faced while caring for their children. These findings would be of paramount importance in planning and devising effective prevention and intervention strategies in Bangladesh as well as other countries with similar sociocultural setting.
Snoring and poor sleep may affect cognition, particularly in young children with chronic conditions. Parents of London preschoolers with sickle cell anemia (SCA; n = 22), matched controls (n = 24), ...and unselected typically developing (n = 142) preschoolers completed sleep questionnaires. Preschoolers with SCA had significantly more sleep problems when compared to matched controls and the larger population. Snoring occurred at least one to two nights a week for 79% of the SCA group. This is compared with 25% of matched controls and 33% of larger population. Randomized controlled trials to improve sleep in young children with SCA already at‐risk for cognitive dysfunction should be considered.
The most common form of neurologic injury in sickle cell anemia (SCA) is silent cerebral infarction (SCI). In the Silent Cerebral Infarct Multi-Center Clinical Trial, we sought to identify risk ...factors associated with SCI. In this cross-sectional study, we evaluated the clinical history and baseline laboratory values and performed magnetic resonance imaging of the brain in participants with SCA (HbSS or HbSβ° thalassemia) between the ages of 5 and 15 years with no history of overt stroke or seizures. Neuroradiology and neurology committees adjudicated the presence of SCI. SCIs were diagnosed in 30.8% (251 of 814) participants who completed all evaluations and had valid data on all prespecified demographic and clinical covariates. The mean age of the participants was 9.1 years, with 413 males (50.7%). In a multivariable logistic regression analysis, lower baseline hemoglobin concentration (P < .001), higher baseline systolic blood pressure (P = .018), and male sex (P = .030) were statistically significantly associated with an increased risk of an SCI. Hemoglobin concentration and systolic blood pressure are risk factors for SCI in children with SCA and may be therapeutic targets for decreasing the risk of SCI. This study is registered at www.clinicaltrials.gov as #NCT00072761.
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