ABSTRACT The collapse of a stellar core is expected to produce gravitational waves (GWs), neutrinos, and in most cases a luminous supernova. Sometimes, however, the optical event could be ...significantly less luminous than a supernova and a direct collapse to a black hole, where the star just disappears, is possible. The GW event GW150914 was detected by the LIGO Virgo Collaboration via a burst analysis that gave localization contours enclosing the Large Magellanic Cloud (LMC). Shortly thereafter, we used DECam to observe 102 deg2 of the localization area, including 38 deg2 on the LMC for a missing supergiant search. We construct a complete catalog of LMC luminous red supergiants, the best candidates to undergo invisible core collapse, and collected catalogs of other candidates: less luminous red supergiants, yellow supergiants, blue supergiants, luminous blue variable stars, and Wolf-Rayet stars. Of the objects in the imaging region, all are recovered in the images. The timescale for stellar disappearance is set by the free-fall time, which is a function of the stellar radius. Our observations at 4 and 13 days after the event result in a search sensitive to objects of up to about 200 solar radii. We conclude that it is unlikely that GW150914 was caused by the core collapse of a relatively compact supergiant in the LMC, consistent with the LIGO Collaboration analyses of the gravitational waveform as best interpreted as a high mass binary black hole merger. We discuss how to generalize this search for future very nearby core-collapse candidates.
OBJECTIVE—Elevated serum amyloid A (SAA) levels are associated with increased cardiovascular risk in humans. Because SAA associates primarily with lipoproteins in plasma and has proteoglycan binding ...domains, we postulated that SAA might mediate lipoprotein retention on atherosclerotic extracellular matrix.
METHODS AND RESULTS—Immunohistochemistry was performed for SAA, apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), and perlecan on proximal aortic lesions from chow-fed low-density lipoprotein receptor (LDLR) and apoE mice euthanized at 10, 50, and 70 weeks. SAA was detected on atherosclerotic lesion extracellular matrix at all time points in both strains. SAA area correlated highly with lesion areas (apoE, r=0.76; LDLR, r=0.86), apoA-I areas (apoE, r=0.88; LDLR, r=0.80), apoB areas (apoE, r=0.74; LDLR, r=0.89), and perlecan areas (apoE, r=0.83; LDLR, r=0.79) (all P<0.0001). In vitro, SAA enrichment increased high-density lipoprotein (HDL) binding to heparan sulfate proteoglycans, and immunoprecipitation experiments using plasma from apoE and LDLR mice demonstrated that SAA was present on both apoA-I–containing and apoB-containing lipoproteins.
CONCLUSIONS—In chow-fed apoE and LDLR mice, SAA is deposited in murine atherosclerosis at all stages of lesion development, and SAA immunoreactive area correlates highly with lesion area, apoA-I area, apoB area, and perlecan area. These findings are consistent with a possible role for SAA-mediated lipoprotein retention in atherosclerosis.
Abstract
Background
Late-relapsing hepatitis after yellow fever (LHep-YF) during the convalescent phase of the disease has been described during recent yellow fever (YF) outbreaks in Brazil. LHep-YF ...is marked by a rebound in liver enzymes and nonspecific clinical manifestations around 46–60 days after YF symptom onset.
Methods
Here we have characterized the clinical course and risk factors for LHep-YF using data from a representative cohort of patients who survived YF in Brazil, 2017–2018. A total of 221 YF-positive patients were discharged from the infectious disease reference hospital in Minas Gerais and were followed up at 30, 45, and 60 days post–symptom onset.
Results
From 46 to 60 days post–symptom onset, 16% of YF patients (n = 36/221) exhibited a rebound of aminotransferases (aspartate aminotransferase or alanine aminotransferase >500 IU/L), alkaline phosphatase, and total bilirubin levels. Other etiologies of liver inflammation such as infectious hepatitis, autoimmune hepatitis, and metabolic liver disease were ruled out. Jaundice, fatigue, headache, and low platelet levels were associated with LHep-YF. Demographic factors, clinical manifestations, laboratory tests, ultrasound findings, and viral load during the acute phase of YF were not associated with the occurrence of LHep-YF.
Conclusions
These findings provide new data on the clinical course of Late-relapsing hepatitis during the convalescent phase of YF and highlight the need for extended patient follow-up after acute YF.
Late-relapsing hepatitis after yellow fever is a clinical picture described around 60 days after the acute yellow fever phase, presenting with nonspecific symptoms, such as fatigue and rebound in aminotransferases, alkaline phosphatase, and total bilirubin values, with a benign final outcome.
Abstract Purpose Sexual activity is an important component of quality of life for women across their lifespan. Prior studies show a decline in sexual activity with age, but these studies often fail ...to consider the role of sexual satisfaction. The aim of this study is to give updated prevalence estimates of sexual activity among women and to elucidate factors associated with sexual activity and sexual satisfaction. Methods We report a cross-sectional analysis of the second wave of a nationally representative sample of US adults aged 28 to 84 years, the Survey of Midlife Development in the United States. The survey used self-administered questionnaires to assess demographic data, self-rated physical and mental health, medical problems and medication use, relationship factors, and sexual activity and satisfaction. Results Of 2,116 women who answered the questions regarding sexuality, 1,345 (61.8%) women were sexually active in the previous 6 months. The proportion of women who were sexually active decreased with advancing age. Women who were married or cohabitating had approximately 8 times higher odds of being sexually active (odds ratio = 7.91, 95% CI, 4.16-15.04; P <.001). Among women aged 60 years and older who were married or cohabitating, most (59.0%) were sexually active. Among women who were sexually active, higher relationship satisfaction ( P <.001), better communication ( P = .011), and higher importance of sex P = .040) were related to higher sexual satisfaction, but age was not ( P = .79). Conclusions A considerable proportion of midlife and older women remain sexually active if they have a partner available. Psychosocial factors (relationship satisfaction, communication with romantic partner, and importance of sex) matter more to sexual satisfaction than aging among midlife and older women.
Patients with thymic tumors (thymoma and thymic carcinoma) are known to respond to a variety of chemotherapeutic agents, including single-agent ifosfamide and cisplatin with etoposide. The purpose of ...this trial was to evaluate the response rate, progression free survival, overall survival, and toxicity of combined etoposide, ifosfamide, and cisplatin (VIP) in patients with advanced thymoma and thymic carcinoma.
From July 1995 through February 1997, 34 patients with advanced thymoma or thymic carcinoma were entered on trial to receive etoposide (75 mg/m2 on Days 1-4) ifosfamide (1.2 g/m2 on Days 1-4), and cisplatin (20 mg/m2 on Days 1-4). Cycles were repeated every 3 weeks for four total cycles.
Among 28 evaluable patients (pathology review excluded 6 patients), there were no complete responses and 9 partial responses (complete and partial responses combined, 32%; 95% confidence interval, 16-52%). The median follow-up was 43 months (range, 12.8-52.3 months), the median duration of response was 11.9 months (range, < 1-26 months), and the median overall survival was 31.6 months. Based on Kaplan-Meier estimates, the 1-year and 2-year survival rates were 89% and 70%, respectively. The toxicity was predominantly myelosuppression.
The VIP regimen has moderate activity in patients with advanced thymic malignancies. However, with limited follow-up, the results of this trial appear to be inferior to other chemotherapy regimens reported in large Phase II trials performed in patients with this disease.
We present evidence that the heritable genetic variation within individual species, especially dominant and keystone species, has community and ecosystem consequences. These consequences represent ...extended phenotypes, i.e., the effects of genes at levels higher than the population. Using diverse examples from microbes to vertebrates, we demonstrate that the extended phenotype can be traced from the individuals possessing the trait, to the community, and to ecosystem processes such as leaf litter decomposition and N mineralization. In our development of a community genetics perspective, we focus on intraspecific genetic variation because the extended phenotypes of these genes can be passed from one generation to the next, which provides a mechanism for heritability. In support of this view, common-garden experiments using synthetic crosses of a dominant tree show that their progeny tend to support arthropod communities that resemble those of their parents. We also argue that the combined interactions of extended phenotypes contribute to the among-community variance in the traits of individuals within communities. The genetic factors underlying this among-community variance in trait expression, particularly those involving genetic interactions among species, constitute community heritability. These findings have diverse implications. (1) They provide a genetic framework for understanding community structure and ecosystem processes. The effects of extended phenotypes at these higher levels need not be diffuse; they may be direct or may act in relatively few steps, which enhances our ability to detect and predict their effects. (2) From a conservation perspective, we introduce the concept of the minimum viable interacting population (MVIP), which represents the size of a population needed to maintain genetic diversity at levels required by other interacting species in the community. (3) Genotype X environment interactions in dominant and keystone species can shift extended phenotypes to have unexpected consequences at community and ecosystem levels, an issue that is especially important as it relates to global change. (4) Documenting community heritability justifies a community genetics perspective and is an essential first step in demonstrating community evolution. (5) Community genetics requires and promotes an integrative approach, from genes to ecosystems, that is necessary for the marriage of ecology and genetics. Few studies span from genes to ecosystems, but such integration is probably essential for understanding the natural world.
The growing propensity to diagnose AD in individuals with very mild cognitive impairment increases the danger of false-positive diagnostic errors. Unfortunately, there is little systematically ...acquired information about the accuracy of the AD diagnosis in very mildly impaired patients.
To determine the accuracy of the diagnosis of AD in very mildly impaired patients and to identify objective measures that effectively distinguish these patients from elderly normal controls (NC).
Consecutive patients with Mini-Mental State Examination scores of > or = 24 who received a clinical diagnosis of AD were evaluated annually for at least 3 years. The initial diagnosis was verified or refuted by autopsy or by information obtained in subsequent evaluations. Initial neuropsychological test scores of verified AD patients were compared with those of NC subjects to identify effective diagnostic measures.
The diagnosis of AD was confirmed in 98 of 110 (89%) very mildly impaired patients (33/36 by autopsy, 65/74 by disease progression). The diagnosis was inaccurate in 12 patients (11%): Seven were subsequently diagnosed with other neurologic disorders, and five were ultimately found to be normal. Neuropsychological measures of delayed recall, verbal fluency, and global cognitive status (i.e., Mattis Dementia Rating Scale) provided excellent sensitivity (> or = 96%) and specificity (> or = 93%) for differentiating between very mildly impaired AD patients and NC subjects.
When comprehensive assessment procedures are employed, AD can be diagnosed with reasonably high accuracy in very mildly impaired individuals. However, the dementia evaluation should be repeated after approximately 1 year to ensure the accuracy of the initial diagnosis.
Synaptic plasticity in the mesolimbic dopamine (DA) system is thought to contribute to the neural adaptations that mediate behavioral sensitization, a model for core aspects of addiction. Recently, ...it has been demonstrated that multiple classes of drugs of abuse, as well as acute stress, enhance strength at excitatory synapses on midbrain DA neurons. Here, we show that both the cocaine- and stress-induced synaptic enhancement involves an up-regulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. This enhancement requires the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit GluRA as evidenced by its absence in mice lacking this subunit. The cocaine-elicited, but not the stress-elicited, synaptic potentiation in DA neurons was blocked by a D1-like receptor antagonist, indicating that the in vivo triggering mechanisms differ for these forms of experience-dependent synaptic modification. Surprisingly, behavioral sensitization to cocaine was elicited in GluRA(-/-) mice, indicating that potentiation of excitatory synaptic transmission in DA neurons is not necessary for this form of behavioral plasticity. However, GluRA(-/-) mice did not exhibit a conditioned locomotor response when placed in a context previously paired with cocaine, nor did they exhibit conditioned place preference in response to cocaine. We suggest that the drug-induced enhancement of excitatory synaptic transmission in midbrain DA neurons, although not required for behavioral sensitization per se, may contribute to the attribution of incentive value to drug-associated cues.
There is an urgent need for a therapy that reverses disability after stroke when initiated in a time frame suitable for the majority of new victims. We show here that intramuscular delivery of ...neurotrophin-3 (NT3, encoded by NTF3) can induce sensorimotor recovery when treatment is initiated 24 h after stroke. Specifically, in two randomized, blinded preclinical trials, we show improved sensory and locomotor function in adult (6 months) and elderly (18 months) rats treated 24 h following cortical ischaemic stroke with human NT3 delivered using a clinically approved serotype of adeno-associated viral vector (AAV1). Importantly, AAV1-hNT3 was given in a clinically-feasible timeframe using a straightforward, targeted route (injections into disabled forelimb muscles). Magnetic resonance imaging and histology showed that recovery was not due to neuroprotection, as expected given the delayed treatment. Rather, treatment caused corticospinal axons from the less affected hemisphere to sprout in the spinal cord. This treatment is the first gene therapy that reverses disability after stroke when administered intramuscularly in an elderly body. Importantly, phase I and II clinical trials by others show that repeated, peripherally administered high doses of recombinant NT3 are safe and well tolerated in humans with other conditions. This paves the way for NT3 as a therapy for stroke.
The placenta is a transient organ that develops upon the initiation of pregnancy and is essential for embryonic development and fetal survival. The rodent placenta consists of distinct lineages and ...includes cell types that are analogous to those that make up the human placenta. Trophoblast cells within the labyrinth layer, which lies closest to the fetus, fuse and come in contact with maternal blood, thus facilitating nutrient and waste exchange between the mother and the baby. Abnormalities of the placenta may occur as a result of cellular stress and have been associated with pregnancy-associated disorders: such as preeclampsia, intrauterine growth restriction, and placental insufficiency. Cellular stress has also been shown to alter proliferation and differentiation rates of trophoblast cells. This stress response is important for cell survival and ensures continued placental functionality. AMP-activated protein kinase is an important sensor of cellular metabolism and stress. To study the role of AMPK in the trophoblast cells, we used RNA interference to simultaneously knockdown levels of both the AMPK alpha isoforms, AMPKα1 and AMPKα2. SM10 trophoblast progenitor cells were transduced with AMPKα1/2 shRNA and stable clones were established to analyze the effects of AMPK knockdown on important cellular functions. Our results indicate that a reduction in AMPK levels causes alterations in cell morphology, growth rate, and nutrient transport, thus identifying an important role for AMPK in the regulation of placental trophoblast differentiation.
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