819 research outputs found

    Population genomics of post-glacial western Eurasia

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    : Western Eurasia witnessed several large-scale human migrations during the Holocene1-5. Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes-mainly from the Mesolithic and Neolithic periods-from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a 'great divide' genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 BP, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a 'Neolithic steppe' cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations

    Respiratory function in a large cohort of treatment-na√Įve adult spinal muscular atrophy patients: a cross-sectional study

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    : Due to poor data in literature, we aimed to investigate the respiratory function in a large cohort of na√Įve Italian adult (‚Č•18 years) SMA patients in a multi-centric cross-sectional study. The following respiratory parameters were considered: forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and need for non-invasive ventilation (NIV). We included 145 treatment-na√Įve adult patients (SMA2=18, SMA3=125; SMA4=2), 58 females (40¬†%), with median age at evaluation of 37 years (range 18-72). Fifty-six (37¬†%) and 41 (31¬†%) patients had abnormal (<80¬†%) values of FVC and FEV1, respectively. Fourteen (14¬†%) patients needed NIV, started at median age of 21 (range 4-68). Motor function, measured by Hammersmith Functional Motor Scale Expanded and Revised Upper Limb Module as well as SMA2, loss of walking ability, surgery for scoliosis, use of NIV, and cough assisting device (CAD) were all significantly associated to lower FVC and FEV1 values, while no association with age at baseline, disease duration, gender or 6¬†min walking test was observed, except for a correlation between FVC and age in SMA3 walkers (p¬†<¬†0.05). In conclusion, respiratory function in adult SMA patients is relatively frequently impaired, substantially stable, and significantly correlated with motor function and disease severity

    An in vivo humanized model to study homing and sequestration of plasmodium falciparum transmission stages in the bone marrow

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    Introduction Recent evidence suggests that the bone marrow (BM) plays a key role in the diffusion of P. falciparum malaria by providing a "niche" for the maturation of the parasite gametocytes, responsible for human-to-mosquito transmission. Suitable humanized in vivo models to study the mechanisms of the interplay between the parasite and the human BM components are still missing. MethodsWe report a novel experimental system based on the infusion of immature P. falciparum gametocytes into immunocompromised mice carrying chimeric ectopic ossicles whose stromal and bone compartments derive from human osteoprogenitor cells. ResultsWe demonstrate that immature gametocytes home within minutes to the ossicles and reach the extravascular regions, where they are retained in contact with different human BM stromal cell types. DiscussionOur model represents a powerful tool to study BM function and the interplay essential for parasite transmission in P. falciparum malaria and can be extended to study other infections in which the human BM plays a role

    Comparison of the skeletal, dentoalveolar, and periodontal changes after Ni‚ÄďTi leaf spring expander and rapid maxillary expansion: a three-dimensional CBCT based evaluation

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    Background: The aim of the present study was twofold:(1) three-dimensionally evaluate the quantitative skeletal and dentoalveolar changes after Ni‚ÄďTi leaf spring expander (leaf expander) and rapid maxillary expansion (RME) in mixed dentition patients;(2) analyze the modifications of the buccal alveolar bone plate of the maxillary first permanent molars. Methods: Patients who underwent CBCT scans before and after maxillary expansion were randomly selected from the records archived at the&nbsp;Department of Biomedical Surgical and Dental Sciences, University of Milan, Italy. Inclusion criteria were the following: no systemic disease or syndromes; maxillary transverse deficiencies (difference between the upper intermolar width and the lower intermolar width of at least 3&nbsp;mm and/or clinical need based on radiographic evaluation), early mixed dentition with ages between 7 to 10&nbsp;years old; cervical vertebra maturation stage (CVMS) 1 or 2; no pathologic periodontal status; skeletal class I or II; maxillary expander cemented on the upper second deciduous molars. Exclusion criteria were the following: patients with pubertal or post-pubertal stage of development (CVMS 3‚Äď6); late deciduous or late mixed dentition, impossibility to use the second primary molar as anchorage; skeletal class III malocclusion; craniofacial syndromes; patients unable to be followed during the treatment period. Twenty-three patients treated with Leaf Expander, 11 males (mean age 7.8 ¬Ī 0.6&nbsp;years) and 12 females (mean age 8.1 ¬Ī 0.8&nbsp;years), met the inclusion criteria and constituted the case group. Twenty-four (control group) treated with conventional RME, 12 males (mean age 8.4 ¬Ī 0.9&nbsp;years) and 12 females (mean age 8.1 ¬Ī 0.7&nbsp;years). The paired-sample T test was used for intra-group comparison to evaluate the difference between before (T1) and after (T2) maxillary expansion. Independent sample t-test was computed to perform between groups comparison of the skeletal, dentoalveolar, and periodontal changes. Results: The Leaf Expander and RME group showed a significant increase between T1 and T2 for most of the skeletal and dentoalveolar variables. Concerning the skeletal variables only the RME demonstrated a significant increase at the level of the posterior nasal (PNW) and apical base width (PABW) and maxillary mid-alveolar width (MMW). Despite this, when compare with the Leaf Expander, the RME group exhibited a statistically larger width increase for only two skeletal parameters: PNW (p = 0.03) and MMW (p = 0.02). No significant changes at the periodontal level were found in either group. Conclusions: According to the current research, the authors confirm the effectiveness of the Leaf Expander and RME to produce similar skeletal and dentoalveolar effects in mixed dentition subjects. Moreover, the devices anchored to deciduous teeth did not reduce the thickness and height of the buccal bone at the level of the maxillary permanent first molars in either of the two groups
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