292 research outputs found
The Genomic Signature of Crop-Wild Introgression in Maize
The evolutionary significance of hybridization and subsequent introgression
has long been appreciated, but evaluation of the genome-wide effects of these
phenomena has only recently become possible. Crop-wild study systems represent
ideal opportunities to examine evolution through hybridization. For example,
maize and the conspecific wild teosinte Zea mays ssp. mexicana, (hereafter,
mexicana) are known to hybridize in the fields of highland Mexico. Despite
widespread evidence of gene flow, maize and mexicana maintain distinct
morphologies and have done so in sympatry for thousands of years. Neither the
genomic extent nor the evolutionary importance of introgression between these
taxa is understood. In this study we assessed patterns of genome-wide
introgression based on 39,029 single nucleotide polymorphisms genotyped in 189
individuals from nine sympatric maize-mexicana populations and reference
allopatric populations. While portions of the maize and mexicana genomes were
particularly resistant to introgression (notably near known
cross-incompatibility and domestication loci), we detected widespread evidence
for introgression in both directions of gene flow. Through further
characterization of these regions and preliminary growth chamber experiments,
we found evidence suggestive of the incorporation of adaptive mexicana alleles
into maize during its expansion to the highlands of central Mexico. In
contrast, very little evidence was found for adaptive introgression from maize
to mexicana. The methods we have applied here can be replicated widely, and
such analyses have the potential to greatly informing our understanding of
evolution through introgressive hybridization. Crop species, due to their
exceptional genomic resources and frequent histories of spread into sympatry
with relatives, should be particularly influential in these studies
Indications for implant removal after fracture healing: a review of the literature
Introduction: The aim of this review was to collect and summarize published data on the indications for implant removal after fracture healing, since these are not well defined and guidelines hardly exist. Methods: A literature search was performed. Results: Though there are several presumed benefits of implant removal, such as functional improvement and pain relief, the surgical procedure can be very challenging and may lead to complications or even worsening of the complaints. Research has focused on the safety of metal implants (e.g., risk of corrosion, allergy, and carcinogenesis). For these reasons, implants have been removed routinely for decades. Along with the introduction of titanium alloy implants, the need for implant removal became a subject of debate in view of potential (dis)advantages since, in general, implants made of titanium alloys are more difficult to remove. Currently, the main indications for removal from both the upper and lower extremity are mostly 'relative' and patient-driven, such as pain, prominent material, or simply the request for removal. True medical indications like infection or intra-articular material are minor reasons. Conclusion: This review illustrates the great variety of view points in the literature, with large differences in opinions and practices about the indications for implant removal after fracture healing. Since some studies have described asymptomatic patients developing complaints after removal, the general advice nowadays is to remove implants after fracture healing only in symptomatic patients and after a proper informed consent. Well-designed prospective studies on this subject are urgently needed in order to form guidelines based on scientific evidence
Role of the Functional Toll-Like Receptor-9 Promoter Polymorphism (-1237T/C) in Increased Risk of End-Stage Renal Disease:A Case-Control Study
Inflammation induced by infectious and noninfectious triggers in the kidney may lead to end stage renal disease (ESRD). Toll-like receptor 9 (TLR-9) a receptor for CpG DNA is involved in activation of immune cells in renal disease and may contribute to chronic inflammatory disease progression through an interleukin-6 (IL-6) dependent pathway. Previous studies indicate that -1237T/C confers regulatory effects on TLR-9 transcription. To date the effect of TLR-9 polymorphisms on ESRD remains unknown. We performed a case-control study and genotyped 630 ESRD patients and 415 controls for -1237T/C, -1486T/C and 1635G/A by real-time PCR assays and assessed plasma concentration of IL-6 by ELISA. Haplotype association analysis was performed using the Haploview package. A luciferase reporter assay and real-time PCR were used to test the function of the -1237T/C promoter polymorphism. A significant association between -1237T/C in TLR-9 and ESRD was identified. The TCA, TTA and CCA haplotype of TLR-9 were associated with ESRD. ESRD patients carrying -1237TC had a higher mean plasma IL-6 level when compared with -1237TT. The TLR-9 transcriptional activity of the variant -1237CC allele is higher than the -1237TT allele. The results indicate that in a Han Chinese population the presence of the C allele of -1237T/C in the TLR-9 gene increases susceptibility towards development of ESRD. In vitro studies demonstrate that -1237T/C may be involved in the development of ESRD through transcriptional modulation of TLR-9
The functional capacity and quality of life of women with advanced breast cancer
The rehabilitation needs of patients with metastatic breast cancer (MBC) are poorly studied. The primary aim of the study was to evaluate the functional capacity of women with MBC and quality of life (QoL). The present study is an open, non-randomized, prospective cross-sectional observation study. The functional capacity of 128 MBC patients with ongoing cancer treatments, were studied in Helsinki University Hospital (HUS): Peak expiratory flow (PEF), dynamic and static balance, 6 minute walking distance (6MWD), 10 meter walking, sit-to-stand test, repeated squat, grip strength, shoulder movement, pain, and QoL by Beck's depression scale (BDI), health assessment questionnaire (HAQ), RAND SF-36 and EORTC QLQ-30 items. The walking capacity was compromised in half and the strength of the lower extremities in one-third of the patients. PEF was below the normal reference in 55 %, static balance in 62 % and dynamic balance in 73 % (= 61 year olds). The grip power was lowered in 44/30 % of the patients (right/left) and the shoulder movement was restricted in 30 %. Some disability in physical functioning experienced 55 % (HAQ) and 37 % felt depressive (BDI). The QoL (RAND SF-36) was poor especially in the field of physical, role and social functioning and bodily pain (<0.001). Pain, depression, and a poor 6MWD results independently determined the physical component of QoL (p <0.001). The functional capacity of patients with MBC was significantly lowered. This, in association with distressing symptoms like pain and depression causes a vicious circle further leading to functional disabilities and impaired QoL.Peer reviewe
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Ginseng and ginkgo biloba effects on cognition as modulated by cardiovascular reactivity: a randomised trial
Background
There is some evidence to suggest that ginseng and Ginkgo biloba can improve cognitive performance, however, very little is known about the mechanisms associated with such improvement. Here, we tested whether cardiovascular reactivity to a task is associated with cognitive improvement.
Methodology/Principal findings
Using a double-blind, placebo controlled, crossover design, participants (N = 24) received two doses of Panax Ginseng (500, 1000 mg) or Ginkgo Biloba (120, 240 mg) (N = 24), and underwent a series of cognitive tests while systolic, diastolic, and heart rate readings were taken. Ginkgo Biloba improved aspects of executive functioning (Stroop and Berg tasks) in females but not in males. Ginseng had no effect on cognition. Ginkgo biloba in females reversed the initial (i.e. placebo) increase in cardiovascular reactivity (systolic and diastolic readings increased compared to baseline) to cognitive tasks. This effect (reversal) was most notable after those tasks (Stroop and Iowa) that elicited the greatest cardiovascular reactivity during placebo. In males, although ginkgo also decreased cardiovascular readings, it did so from an initial (placebo) blunted response (i.e. decrease or no change from baseline) to cognitive tasks. Ginseng, on the contrary, increased cardiovascular readings compared to placebo.
Conclusions/Significance
These results suggest that cardiovascular reactivity may be a mechanism by which ginkgo but not ginseng, in females is associated with certain forms of cognitive improvement
The interaction of bacterial pathogens with platelets.
In recent years, the frequency of serious cardiovascular infections such as endocarditis has increased, particularly in association with nosocomially acquired antibiotic-resistant pathogens. Growing evidence suggests a crucial role for the interaction of bacteria with human platelets in the pathogenesis of cardiovascular infections. Here, we review the nature of the interactions between platelets and bacteria, and the role of these interactions in the pathogenesis of endocarditis and other cardiovascular diseases
Societal-level versus individual-level predictions of ethical behavior: a 48-society study of collectivism and individualism
Is the societal-level of analysis sufficient today to understand the values of those in the global workforce? Or are individual-level analyses more appropriate for assessing the influence of values on ethical behaviors across country workforces? Using multi-level analyses for a 48-society sample, we test the utility of both the societal-level and individual-level dimensions of collectivism and individualism values for predicting ethical behaviors of business professionals. Our values-based behavioral analysis indicates that values at the individual-level make a more significant contribution to explaining variance in ethical behaviors than do values at the societal-level. Implicitly, our findings question the soundness of using societal-level values measures. Implications for international business research are discussed
Full-length human placental sFlt-1-e15a isoform induces distinct maternal phenotypes of preeclampsia in mice
<div><p>Objective</p><p>Most anti-angiogenic preeclampsia models in rodents utilized the overexpression of a truncated soluble fms-like tyrosine kinase-1 (sFlt-1) not expressed in any species. Other limitations of mouse preeclampsia models included stressful blood pressure measurements and the lack of postpartum monitoring. We aimed to 1) develop a mouse model of preeclampsia by administering the most abundant human placental sFlt-1 isoform (hsFlt-1-e15a) in preeclampsia; 2) determine blood pressures in non-stressed conditions; and 3) develop a survival surgery that enables the collection of fetuses and placentas and postpartum (PP) monitoring.</p><p>Methods</p><p>Pregnancy status of CD-1 mice was evaluated with high-frequency ultrasound on gestational days (GD) 6 and 7. Telemetry catheters were implanted in the carotid artery on GD7, and their positions were verified by ultrasound on GD13. Mice were injected through tail-vein with adenoviruses expressing hsFlt-1-e15a (n = 11) or green fluorescent protein (GFP; n = 9) on GD8/GD11. Placentas and pups were delivered by cesarean section on GD18 allowing PP monitoring. Urine samples were collected with cystocentesis on GD6/GD7, GD13, GD18, and PPD8, and albumin/creatinine ratios were determined. GFP and hsFlt-1-e15a expression profiles were determined by qRT-PCR. Aortic ring assays were performed to assess the effect of hsFlt-1-e15a on endothelia.</p><p>Results</p><p>Ultrasound predicted pregnancy on GD7 in 97% of cases. Cesarean section survival rate was 100%. Mean arterial blood pressure was higher in hsFlt-1-e15a-treated than in GFP-treated mice (∆MAP = 13.2 mmHg, p = 0.00107; GD18). Focal glomerular changes were found in hsFlt-1-e15a -treated mice, which had higher urine albumin/creatinine ratios than controls (109.3±51.7μg/mg vs. 19.3±5.6μg/mg, p = 4.4x10<sup>-2</sup>; GD18). Aortic ring assays showed a 46% lesser microvessel outgrowth in hsFlt-1-e15a-treated than in GFP-treated mice (p = 1.2x10<sup>-2</sup>). Placental and fetal weights did not differ between the groups. One mouse with liver disease developed early-onset preeclampsia-like symptoms with intrauterine growth restriction (IUGR).</p><p>Conclusions</p><p>A mouse model of late-onset preeclampsia was developed with the overexpression of hsFlt-1-e15a, verifying the <i>in vivo</i> pathologic effects of this primate-specific, predominant placental sFlt-1 isoform. HsFlt-1-e15a induced early-onset preeclampsia-like symptoms associated with IUGR in a mouse with a liver disease. Our findings support that hsFlt-1-e15a is central to the terminal pathway of preeclampsia, and it can induce the full spectrum of symptoms in this obstetrical syndrome.</p></div
Papillary fibroelastoma of the aortic valve - a case report and literature review
The prevalence of primary cardiac tumour ranges from 0.0017-0.28% and papillary fibroelastoma is rare but not uncommon benign cardiac neoplasm. Currently, with the advent of higher-resolution imaging technology especially transoesophageal echocardiography such cases being recognized frequently. The clinical presentation of these tumours varies from asymptomatic to severe ischaemic or embolic complications. We herein, present a 50-year-old female patient with a papillary fibroelastoma of the aortic valve arising from the endocardium of the right coronary cusp very close to the commissure between the right and non-coronary cusps. The patient presented with angina-like chest pain and was investigated using echocardiography and CT angiographic modalities in addition to the usual investigations. The differential diagnosis considered was a thrombus, myxoma, Lambl's excrescence and infective vegetation. The surgical management included a prompt resection of the tumour on cardiopulmonary bypass avoiding injury to the aortic valve. The patient recovered well. A review of the literature suggests that the cardiac papillary fibroelastoma is a rare but potentially treatable cause of embolic stroke and other fatal complications, therefore, a strong suspicion; appropriate use of imaging modality, preoperative anticoagulation and urgent surgical resection is warranted. Also, possibility of this diagnosis should be kept in mind while managing cardiac or valvular tumours
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