Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Neurotactin, a membrane-anchored chemokine upregulated in brain inflammation

Chemokines are small secreted proteins that stimulate the directional migration of leukocytes and mediate inflammation. During screening of a murine choroid plexus complementary DNA library, we identified a new chemokine, designated neurotactin. Unlike other chemokines, neurotactin has a unique cysteine pattern, Cys-X-X-X-Cys, and is predicted to be a type 1 membrane protein. Full-length recombinant neurotactin is localized on the surface of transfected 293 cells. Recombinant neurotactin containing the chemokine domain is chemotactic for neutrophils both in vitro and in vivo. Neurotactin messenger RNA is predominantly expressed in normal murine brain and its protein expression in activated brain microglia is upregulated in mice with experimental autoimmune encephalomyelitis, as well as in mice treated with lipopolysaccharide. Distinct from all other chemokine genes, the neurotactin gene is localized to human chromosome 16q. Consequently we propose that neurotactin represents a new delta-chemokine family and that it may play a role in brain inflammation processes.

Cardiac progenitor cell-derived exosomes prevent cardiomyocytes apoptosis through exosomal miR-21 by targeting PDCD4

Cardiac progenitor cells derived from adult heart have emerged as one of the most promising stem cell types for cardiac protection and repair. Exosomes are known to mediate cell–cell communication by transporting cell-derived proteins and nucleic acids, including various microRNAs (miRNAs). Here we investigated the cardiac progenitor cell (CPC)-derived exosomal miRNAs on protecting myocardium under oxidative stress. Sca1⁺CPCs-derived exosomes were purified from conditional medium, and identified by nanoparticle trafficking analysis (NTA), transmission electron microscopy and western blotting using CD63, CD9 and Alix as markers. Exosomes production was measured by NTA, the result showed that oxidative stress-induced CPCs secrete more exosomes compared with normal condition. Although six apoptosis-related miRNAs could be detected in two different treatment-derived exosomes, only miR-21 was significantly upregulated in oxidative stress-induced exosomes compared with normal exosomes. The same oxidative stress could cause low miR-21 and high cleaved caspase-3 expression in H9C2 cardiac cells. But the cleaved caspase-3 was significantly decreased when miR-21 was overexpressed by transfecting miR-21 mimic. Furthermore, miR-21 mimic or inhibitor transfection and luciferase activity assay confirmed that programmed cell death 4 (PDCD4) was a target gene of miR-21, and miR-21/PDCD4 axis has an important role in anti-apoptotic effect of H9C2 cell. Western blotting and Annexin V/PI results demonstrated that exosomes pre-treated H9C2 exhibited increased miR-21 whereas decreased PDCD4, and had more resistant potential to the apoptosis induced by the oxidative stress, compared with non-treated cells. These findings revealed that CPC-derived exosomal miR-21 had an inhibiting role in the apoptosis pathway through downregulating PDCD4. Restored miR-21/PDCD4 pathway using CPC-derived exosomes could protect myocardial cells against oxidative stress-related apoptosis. Therefore, exosomes could be used as a new therapeutic vehicle for ischemic cardiac disease.

Resistance of Listeria monocytogenes biofilms to sanitizing agents in a simulated food processing environment

The objective of this study was to evaluate the resistance of biofilms of Listeria monocytogenes to sanitizing agents under laboratory conditions simulating a food processing environment. Biofilms were initially formed on stainless steel and Teflon coupons using a five-strain mixture of L. monocytogenes. The coupons were then subjected to repeated 24-h daily cycles. Each cycle consisted of three sequential steps: (i) a brief (60 s) exposure of the coupons to a sanitizing agent (a mixture of peroxides) or saline as a control treatment, (ii) storage of the coupons in sterile plastic tubes without any nutrients or water for 15 h, (iii) and incubation of the coupons in diluted growth medium for 8 h. This regimen was repeated daily for up to 3 weeks and was designed to represent stresses encountered by bacteria in a food processing environment. The bacteria on the coupons were reduced in number during the first week of the simulated food processing (SFP) regimen, but then adapted to the stressful conditions and increased in number. Biofilms repeatedly exposed the peroxide sanitizer in the SFP regimen developed resistance to the peroxide sanitizer as well as other sanitizers (quaternary ammonium compounds and chlorine). Interestingly, cells that were removed from the biofilms on peroxide-treated and control coupons were not significantly different in their resistance to sanitizing agents. These data suggest that the resistance of the treated biofilms to sanitizing agents may be due to attributes of extracellular polymeric substances and is not an intrinsic attribute of the cells in the biofilm.

Application of Physiologically Based Pharmacokinetic (PBPK) Modeling to Support Dose Selection: Report of an FDA Public Workshop on PBPK

The US Food and Drug Administration (FDA) public workshop, entitled "Application of Physiologically-based Pharmacokinetic (PBPK) Modeling to Support Dose Selection focused on the role of PBPK in drug development and regulation. Representatives from industry, academia, and regulatory agencies discussed the issues within plenary and panel discussions. This report summarizes the discussions and provides current perspectives on the application of PBPK in different areas, including its utility, predictive performance, and reporting for regulatory submissions.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Natural history of Streptococcus sanguinis in the oral cavity of infants: evidence for a discrete window of infectivity

The heterogeneous group of oral bacteria within the sanguinis (sanguis) streptococci comprise members of the indigenous biota of the human oral cavity. While the association of Streptococcus sanguinis with bacterial endocarditis is well described in the literature, S. sanguinis is thought to play a benign, if not a beneficial, role in the oral cavity. Little is known, however, about the natural history of S. sanguinis and its specific relationship with other oral bacteria. As part of a longitudinal study concerning the transmission and acquisition of oral bacteria within mother-infant pairs, we examined the initial acquisition of S. sanguinis and described its colonization relative to tooth emergence and its proportions in plaque and saliva as a function of other biological events, including subsequent colonization with mutans streptococci. A second cohort of infants was recruited to define the taxonomic affiliation of S. sanguinis. We found that the colonization of the S. sanguinis occurs during a discrete "window of infectivity" at a median age of 9 months in the infants. Its colonization is tooth dependent and correlated to the time of tooth emergence; its proportions in saliva increase as new teeth emerge. In addition, early colonization of S. sanguinis and its elevated levels in the oral cavity were correlated to a significant delay in the colonization of mutans streptococci. Underpinning this apparent antagonism between S. sanguinis and mutans streptococci is the observation that after mutans streptococci colonize the infant, the levels of S. sanguinis decrease. Children who do not harbor detectable levels of mutans streptococci have significantly higher levels of S. sanguinis in their saliva than do children colonized with mutans streptococci. Collectively, these findings suggest that the colonization of S. sanguinis may influence the subsequent colonization of mutans streptococci, and this in turn may suggest several ecological approaches toward controlling dental caries.

Phosphorylation-dependent regulation of cardiac Na+/Ca2+ exchanger via protein kinase C

The cardiac Na+/Ca2+ exchanger (NCX1) plays a major role in the extrusion of Ca2+ from cardiomyocytes. We studied the role of protein phosphorylation in the regulation of cardiac NCX1 using CCL39 stably overexpressing the canine cardiac NCX1 and rat neonatal cardiomyocytes. In both cell types, the NCX1 protein immunoprecipitated with a chicken anti-NCX1 antibody exhibited a significant basal phosphorylation that was further enhanced by treatment with endothelin-1, acidic fibroblast growth factor, phorbol 12-myristate 13-acetate, or okadaic acid. In contrast, calphostin C, K252a, or EGTA inhibited the phosphorylation. The phosphorylation occurred on two major tryptic phosphopeptides (P1 and P2) exclusively on serine residues. Evidence is presented suggesting that P2 was derived from an N-terminal half (amino acids 240-475) of the central cytoplasmic domain of NCX1 and was phosphorylated directly by protein kinase C (PKC). The agents that increased NCX1 phosphorylation significantly enhanced both the forward and reverse modes of Na+/Ca2+ exchange. This exchange activation exhibited a very good correlation with the NCX1 phosphorylation. In NCX1-transfected cells, PKC down-regulation following prolonged exposure to phorbol 12-myristate 13-acetate abolished the acidic fibroblast growth factor-induced activation of exchange activity. On the other hand, cell ATP depletion reduced the exchange activity and abolished the effects of the above agents on exchange activity. These results indicate that the cardiac NCX1 is up-regulated by PKC-catalyzed phosphorylation. The cardiac NCX1 thus could play an important role in the previously reported negative inotropic actions of phorbol esters and other PKC-activating agents.

Mutations in the V2 vasopressin receptor gene are associated with X-linked nephrogenic diabetes insipidus

X-linked nephrogenic diabetes insipidus (NDI) is a rare disorder in which the kidney is insensitive to the antidiuretic hormone, vasopressin. It has been proposed that the kidney-specific V2 vasopressin receptor, a G protein-coupled receptor, is defective in this disorder as both the disease and the receptor map to Xq28. We report six unique mutations in the V2 receptor gene of five unrelated NDI patients, with one patient having two mutations. The most severely affected patient has a nonsense mutation which would terminate the protein in transmembrane domain III. Other mutations include three missense mutations, a frameshift and one small in-frame deletion. These results represent one of the first examples of recessive mutations affecting a G protein-coupled receptor.

PTEN induces chemosensitivity in PTEN-mutated prostate cancer cells by suppression of Bcl-2 expression

The tumor suppressor gene PTEN (MMAC1/TEP1) is lost frequently in advanced prostate cancer (PCa). However, the function of PTEN in tumorigenesis is not understood fully. In this study, we demonstrate that expression of Bcl-2 in prostate tumors correlates with loss of the PTEN protein. This finding was verified by studies in the PCa cell lines DU145, PC-3, LNCaP, and an androgen-refractory subline of LNCaP. Transient transfection of PTEN into the PTEN-null cells resulted in decreased levels of Bcl-2 mRNA and protein. These effects appear to be mediated at the level of gene transcription, since a Bcl-2 promoter-reporter construct was down-regulated by ectopic expression of PTEN in LNCaP cells. The inhibition of Bcl-2 required the lipid-phosphatase activity of PTEN and was blocked by overexpression of a constitutively active form of Akt. Moreover, the transcription-regulatory protein cAMP-response element-binding protein (CREB) may be involved, since decreased phosphorylation of CREB at Ser(133) was detected following PTEN expression, and ectopic expression of CREB repressed completely the PTEN-induced inhibition of Bcl-2 promoter activity. Furthermore, cotransfection of Bcl-2 and PTEN expression vectors rescued PTEN-induced cell death but not G(1) cell cycle arrest. Finally, forced expression of PTEN sensitized LNCaP cells to cell death induced by staurosporine, doxorubicin, and vincristine, and this chemosensitivity was attenuated by exogenous expression of Bcl-2. Taken together, these data demonstrate that loss of PTEN leads to up-regulation of the bcl-2 gene, thus contributing to survival and chemoresistance of PCa cells. These findings suggest that the PTEN gene and its regulated pathway are potential therapeutic targets in prostate cancer.

Identification and gene organization of three novel members of the IL-1 family on human chromosome 2

Members of the IL-1 family of cytokines are important in mediating inflammatory responses. The genes encoding IL-1alpha, IL-beta, and the IL-1 receptor antagonist (IL-1Ra) are clustered within 450 kb on human chromosome 2q. By searching the EST databases and sequencing this region of chromosome 2, we have identified three novel genes that show homology to the IL-1 family, which we have named IL-1-related protein 1, 2, and 3 (IL-1RP1, IL-1RP2, and IL-1RP3). All three genes contain a signature motif common to the IL-1 family and appear to be more closely related to IL-1Ra. Similar to the intracellular form of IL-1Ra, these genes lack conventional hydrophobic signal sequences. The expression of these genes appears to be highly restricted to various epithelial cell populations. Our results demonstrate the existence of additional IL-1 gene family members within the previously defined IL-1 cluster and point to this region of chromosome 2 as an evolutionary hotspot for IL-1 gene duplication. These genes may prove to have an important role in inflammatory responses.

Bidirectional signaling between sarcoglycans and the integrin adhesion system in cultured L6 myocytes

The rat L6 skeletal muscle cell line was used to study expression of the dystrophin-containing glycoprotein complex and its interaction with the integrin system involved in the cell-matrix adhesion reaction. A complex of dystrophin and its associated proteins was fully expressed in L6 myotubes, from which anti-dystrophin or anti-alpha-sarcoglycan co-precipitated integrin alpha 5 beta 1 and other focal adhesion-associated proteins vinculin, talin, paxillin, and focal adhesion kinase. Immunostaining and confocal microscopy revealed that dystrophin, alpha-sarcoglycan, integrin alpha 5 beta 1, and vinculin exhibited overlapping distribution in the sarcolemma, especially at focal adhesion-like, spotty structures. Adhesion of cells to fibronectin- or collagen type I-coated dishes resulted in induction of tyrosine phosphorylation of alpha- and gamma-sarcoglycans but not beta-sarcoglycan. The same proteins were also tyrosine-phosphorylated when L6 cells in suspension were exposed to Arg-Gly-Asp-Ser peptide. All of these tyrosine phosphorylations were inhibited by herbimycin A. On the other hand, treatment of L6 myotubes with alpha- and gamma-sarcoglycan antisense oligodeoxynucleotides resulted in complete disappearance of alpha- and gamma-sarcoglycans and in significant reduction of levels of the associated focal adhesion proteins, which caused about 50% reduction of cell adhesion. These results indicate the existence of bidirectional communication between the dystrophin-containing complex and the integrin adhesion system in cultured L6 myocytes.

Baseline IOP predicts selective laser trabeculoplasty success at 1 year post-treatment: results from a randomised clinical trial

BACKGROUND/AIMS

The efficacy and safety of selective laser trabeculoplasty (SLT) has been found to be equivalent to argon laser trabeculoplasty (ALT). Since SLT produces significantly less disturbance to the trabecular meshwork and is theoretically more repeatable than ALT, it has potential to replace ALT as the standard procedure to treat medically uncontrolled open angle glaucoma. This study's objective is to determine factors that predict successful SLT at 1 year post-treatment.

METHODS

As part of a randomised clinical trial comparing the efficacy and safety of SLT to ALT, data on 72 SLT patients were collected, and successful SLT defined as having an SLT induced intraocular pressure (IOP) reduction of >or=20% at 1 year post-treatment follow up.

RESULTS

43 out of the 72 patients who had completed their 1 year follow up visit had an IOP reduction of >or=20% from baseline. No glaucoma risk factors studied predicted successful SLT. The amount of trabecular meshwork pigmentation was not a significant predictor. However, it was discovered that baseline IOP strongly predicted SLT success (odds ratio=1.16; p=0.0001).

CONCLUSION

SLT success was significantly predicted by baseline IOP but not by age, sex, other glaucoma risk factors, type of open angle glaucoma, or by degree of trabecular meshwork pigmentation.

Improved metagenome assemblies and taxonomic binning using long-read circular consensus sequence data

DNA assembly is a core methodological step in metagenomic pipelines used to study the structure and function within microbial communities. Here we investigate the utility of Pacific Biosciences long and high accuracy circular consensus sequencing (CCS) reads for metagenomic projects. We compared the application and performance of both PacBio CCS and Illumina HiSeq data with assembly and taxonomic binning algorithms using metagenomic samples representing a complex microbial community. Eight SMRT cells produced approximately 94 Mb of CCS reads from a biogas reactor microbiome sample that averaged 1319 nt in length and 99.7% accuracy. CCS data assembly generated a comparative number of large contigs greater than 1 kb, to those assembled from a ~190x larger HiSeq dataset (~18 Gb) produced from the same sample (i.e approximately 62% of total contigs). Hybrid assemblies using PacBio CCS and HiSeq contigs produced improvements in assembly statistics, including an increase in the average contig length and number of large contigs. The incorporation of CCS data produced significant enhancements in taxonomic binning and genome reconstruction of two dominant phylotypes, which assembled and binned poorly using HiSeq data alone. Collectively these results illustrate the value of PacBio CCS reads in certain metagenomics applications.

Comparative immunohistochemical distributions of carboxy terminus epitopes from the mu-opioid receptor splice variants MOR-1D, MOR-1 and MOR-1C in the mouse and rat CNS

The present study examined immunohistochemically the CNS distributions of a splice variant of the mu-opioid receptor, MOR-1D, in both rats and mice. In MOR-1D, exon 4 of MOR-1 is replaced by two additional exons that code for seven amino acids. Using rabbit antisera, we compared immunohistochemically the regional distribution of a C-terminal epitope of MOR-1D to that of a C-terminal epitope from MOR-1 and a C-terminal epitope from another splice variant, MOR-1C. The general distribution of MOR-1D-like immunoreactivity was similar in both mouse and rat. MOR-1D-like immunoreactivity was seen in the dentate gyrus and in the mossy fibers of the hippocampal formation, the nucleus of the solitary tract and the area postrema, the inferior olivary nucleus, the nucleus ambiguous, the spinal trigeminal nucleus and the spinal cord. MOR-1D-like immunoreactivity was not observed in some regions containing dense MOR-1-like immunoreactivity, such as the striatum or the locus coeruleus. In regions containing MOR-1, MOR-1C and MOR-1D, the pattern of each variant was unique.MOR-1D and MOR-1C are splice variants of the cloned mu-opioid receptor MOR-1. Although they differ only at the tip of the carboxy terminus, they show marked differences in their regional distributions, as determined immunohistochemically by epitopes in their unique carboxy termini. Since the splice variants are derived from the same gene, these differences in regional distribution imply region-specific messenger RNA processing.

Synthesis and biological activities of potent peptidomimetics selective for somatostatin receptor subtype 2

A series of nonpeptide somatostatin agonists which bind selectively and with high affinity to somatostatin receptor subtype 2 (sst2) have been synthesized. One of these compounds, L-054,522, binds to human sst2 with an apparent dissociation constant of 0.01 nM and at least 3,000-fold selectivity when evaluated against the other somatostatin receptors. L-054,522 is a full agonist based on its inhibition of forskolin-stimulated adenylate cyclase activity in Chinese hamster ovary-K1 cells stably expressing sst2. L-054,522 has a potent inhibitory effect on growth hormone release from rat primary pituitary cells and glucagon release from isolated mouse pancreatic islets. Intravenous infusion of L-054,522 to rats at 50 microgram/kg per hr causes a rapid and sustained reduction in growth hormone to basal levels. The high potency and selectivity of L-054, 522 for sst2 will make it a useful tool to further characterize the physiological functions of this receptor subtype.

Evidence for an excess of B→D*τ(-)ν(τ) decays

Based on the full BABAR data sample, we report improved measurements of the ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D(*))=0.332±0.024±0.018, which exceed the standard model expectations by 2.0σ and 2.7σ, respectively. Taken together, our results disagree with these expectations at the 3.4σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

Endoscopic optical coherence tomography based on a microelectromechanical mirror

An endoscopic optical coherence tomography (OCT) system based on a microelectromechanical mirror to facilitate lateral light scanning is described. The front-view OCT scope, adapted to the instrument channel of a commercial endoscopic sheath, allows real-time cross-sectional imaging of living biological tissue via direct endoscopic visual guidance. The transverse and axial resolutions of the OCT scope are roughly 20 and 10.2mum, respectively. Cross-sectional images of 500x1000 pixels covering an area of 2.9 mmx2.8 mm can be acquired at ~5 frames/s and with nearly 100-dB dynamic range. Applications in thickness measurement and bladder tissue imaging are demonstrated.

Ethnic difference in the relationship between acute inflammation and serum ferritin in US adult males

This study examined the ethnic difference in the association between increased serum ferritin (SF) (>300 microg/l) and acute inflammation (AI) (C-reactive protein > or = 1.0 mg/dl) between black and white males aged > or = 20 years. Using data from the third National Health and Nutrition Examination Survey (NHANES III), we determined the risk for having elevated SF in black males (n=164) and white males (n=325) with AI present as well as black males (n=1731) and white males (n=2877) with AI absent. Black subjects with AI present were 1.71 times (95% CI 1.18-2.49), and 1.87 times (95% CI 1.46-2.40) more likely to have increased SF than AI absent blacks and AI present whites, respectively. Furthermore, with AI present, every increment of C-reactive protein, white blood cell count, serum albumin, lymphocyte count and platelet count was associated with higher odds of having elevations in SF in blacks than whites. Regardless of AI status, blacks were more likely to have elevations in SF than whites, and the prevalence of elevated SF was significantly higher in blacks than whites. This finding suggested that black males may respond to inflammation with a more aggressive rise in SF compared to white males. Future research is needed to investigate the underlying mechanisms.