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The East Africa Consortium was formed to study the epidemiology of human papillomavirus (HPV) infections and cervical cancer and the influence of human immunodeficiency virus (HIV) infection on HPV and cervical cancer, and to encourage collaborations between researchers in North America and East African countries. To date, studies have led to a better understanding of the influence of HIV infection on the detection and persistence of oncogenic HPV, the effects of dietary aflatoxin on the persistence of HPV, the benefits of antiretroviral therapy on HPV persistence, and the differences in HPV detections among HIV-infected and HIV-uninfected women undergoing treatment for cervical dysplasia by either cryotherapy or LEEP. It will now be determined how HPV testing fits into cervical cancer screening programs in Kenya and Uganda, how aflatoxin influences immunological control of HIV, how HPV alters certain genes involved in the growth of tumours in HIV-infected women. Although there have been challenges in performing this research, with time, this work should help to reduce the burden of cervical cancer and other cancers related to HIV infection in people living in sub-Saharan Africa, as well as optimized processes to better facilitate research as well as patient autonomy and safety. KEY MESSAGESThe East Africa Consortium was formed to study the epidemiology of human papillomavirus (HPV) infections and cervical cancer and the influence of human immunodeficiency virus (HIV) infection on HPV and cervical cancer.Collaborations have been established between researchers in North America and East African countries for these studies.Studies have led to a better understanding of the influence of HIV infection on the detection and persistence of oncogenic HPV, the effects of dietary aflatoxin on HPV detection, the benefits of antiretroviral therapy on HPV persistence, and the differences in HPV detections among HIV-infected and HIV-uninfected women undergoing treatment for cervical dysplasia by either cryotherapy or LEEP.
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Aflatoxinas , Alphapapillomavirus , Infecciones por VIH , Infecciones por Papillomavirus , Displasia del Cuello del Útero , Neoplasias del Cuello Uterino , Detección Precoz del Cáncer , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Papillomaviridae/genética , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/epidemiología , Neoplasias del Cuello Uterino/epidemiología , Displasia del Cuello del Útero/epidemiologíaRESUMEN
This study evaluated the chronic effects of nitrate (NO3-) ingestion over three days, on 40 km TT performance in 11trained cyclists (VO2max: 60.8 ± 7.4 ml.kg-1.min-1; age: 36 ± 9 years; height: 1.80 ± 0.06 m; body mass: 87.2 ± 12.0 kg). Utilising a double-blind randomised cross-over design, participants completed three 40 km TT on a Velotron® ergometer following the ingestion of either a 140 ml of "BEET It sport®" NO3- shot containing 12.8 mmol or 800 mg of NO3-, a placebo drink or nothing (control). Performance, oxygen consumption (VO2), blood bicarbonate (HCO3-), pH and lactate (BLa) and ratings of perceived exertion (RPE) were measured every 10 km throughout the TT. The present findings show that NO3- ingestion had no effect on TT performance (NO3-: 4098.0 ± 209.8 vs. Placebo: 4161.9 ± 263.3 s, p = 0.296, ES = 0.11), or VO2 (p = 0.253, ES = 0.13). Similarly, blood lactate and RPE were also unaffected by the experimental conditions (p = 0.522, ES = 0.06; p = 0.085, ES = 0.30) respectively. Therefore, these results suggest that a high dose of NO3- over three days has limited efficacy as an ergogenic aid for 40 km TT cycling performance in trained cyclists.
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Rendimiento Atlético/fisiología , Ciclismo/fisiología , Nitratos/administración & dosificación , Sustancias para Mejorar el Rendimiento/administración & dosificación , Adulto , Beta vulgaris , Estudios Cruzados , Método Doble Ciego , Humanos , Ácido Láctico/sangre , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/efectos de los fármacosRESUMEN
This report documents the International Committee on Systematics of Prokaryotes Subcommittee on the taxonomy of Mollicutes by recording the minutes of the meeting, held 8 July 2018, Portsmouth, New Hampshire, USA.
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OBJECTIVE: The objective of the present study is to analyze prognostic factors affecting survival of patients receiving stereotactic radiosurgery (SRS) for second brain metastatic event (SBME) following initial treatment with whole brain irradiation (WBI), surgical resection, or previous SRS. METHODS: The 88 patients treated with SRS for SBME at Philadelphia CyberKnife between January 2006 and October 2013 were included in the study group. Cox proportional-hazards regression was used to identify prognostic factors that significantly impacted survival from the time of SRS for SBME. Independent variables considered in survival analysis included primary disease, first brain metastatic event (FBME) treatment type, age, gender, number of brain metastases at SBME, Karnofsky performance status (KPS), recursive partitioning analysis (RPA), and presence of extracranial metastasis. RESULTS: The median survival for all patients was 7.31 months. Log-rank comparison of Kaplan-Meier survival curves revealed significant impact by Karnofsky performance status (p = 0.003), RPA class (p = 0.008), age (p = 0.014), and FBME treatment type (p = 0.010). Median survival was longer for patients who had not previously received WBI (14.7 months). Median survival was further increased in patients who had not received previous WBI and demonstrated KPS scores of 70-100 (19.5 months). Patients who received WBI prior to SBME treatment experienced a pronounced decrement in median survival (5.7 months), yet patients in this group who demonstrated strong KPS scores (80-100) experienced significantly increased survival (15.5 months). CONCLUSIONS: The outcomes of SRS for SBME are most favorable for patients who have not received previous WBI or who have maintained higher performance status despite previous WBI.
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Modern spallation neutron sources generate high intensity neutron beams with a broad wavelength band applied to exploring new nano- and meso-scale materials from a few atomic monolayers thick to complicated prototype device-like systems with multiple buried interfaces. The availability of high performance neutron polarizers and analyzers in neutron scattering experiments is vital for understanding magnetism in systems with novel functionalities. We report the development of a new generation of the in situ polarized 3He neutron polarization analyzer for the Magnetism Reflectometer at the Spallation Neutron Source at Oak Ridge National Laboratory. With a new optical layout and laser system, the 3He polarization reached and maintained 84% as compared to 76% in the first-generation system. The polarization improvement allows achieving the transmission function varying from 50% to 15% for the polarized neutron beam with the wavelength band of 2-9 Angstroms. This achievement brings a new class of experiments with optimal performance in sensitivity to very small magnetic moments in nano systems and opens up the horizon for its applications.
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The σ factor is a functionally obligatory subunit of the bacterial transcription machinery, the RNA polymerase. Bacteriophage-encoded small proteins that either modulate or inhibit the bacterial RNAP to allow the temporal regulation of bacteriophage gene expression often target the activity of the major bacterial σ factor, σ70. Previously, we showed that during Xanthomonas oryzae phage Xp10 infection, the phage protein P7 inhibits the host RNAP by preventing the productive engagement with the promoter and simultaneously displaces the σ70 factor from the RNAP. In this study, we demonstrate that P7 also inhibits the productive engagement of the bacterial RNAP containing the major variant bacterial σ factor, σ54, with its cognate promoter. The results suggest for the first time that the major variant form of the host RNAP can also be targeted by bacteriophage-encoded transcription regulatory proteins. Since the major and major variant σ factor interacting surfaces in the RNAP substantially overlap, but different regions of σ70 and σ54 are used for binding to the RNAP, our results further underscore the importance of the σ-RNAP interface in bacterial RNAP function and regulation and potentially for intervention by antibacterials.
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Proteínas Bacterianas/antagonistas & inhibidores , Bacteriófagos/crecimiento & desarrollo , ARN Polimerasas Dirigidas por ADN/antagonistas & inhibidores , Interacciones Huésped-Parásitos , Transcripción Genética , Proteínas Virales/metabolismo , Xanthomonas/virología , Regiones Promotoras Genéticas , Unión Proteica , Factor sigma/metabolismo , Xanthomonas/genéticaRESUMEN
High affinity aryl hydrocarbon receptor (AHR) ligands, such as certain polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), cause severe cardiac teratogenesis in fish embryos. Moderately strong AHR agonists, for example benzo[a]pyrene and ß-naphthoflavone, are capable of causing similar cardiotoxic effects, particularly when coupled with cytochrome P450 1A (CYP1A) inhibitors (e.g., fluoranthene (FL). Additionally, some weaker AHR agonists (carbaryl, 2-methylindole, 3-methylindole, and phenanthrene) are known to also cause cardiotoxicity in zebrafish (Danio rerio) embryos when coupled with FL; however, the cardiotoxic effects were not mediated specifically by AHR stimulation. This study was performed to determine if binary exposure to weak AHR agonists and FL were also capable of causing cardiotoxicity in Atlantic killifish Fundulus heteroclitus embryos. Binary exposures were performed in both naïve and PAH-adapted killifish embryos to examine resistance to weak agonists and FL binary exposures. Weak agonists used in this study included the following: carbaryl, phenanthrene, 2-methylindole, 3-methylindole, indigo, and indirubin. Carbaryl, indigo, and indirubin induced the highest CYP1 activity levels in naïve killifish embryos, but no significant CYP1 induction was observed in the PAH-adapted killifish. Embryos were coexposed to subteratogenic levels of each agonist and 500µg/L FL to assess if binary administration could cause cardiotoxicity. Indigo and indirubin coupled with FL caused cardiac teratogenesis in naïve killifish, but coexposures did not produce cardiac chamber abnormalities in the PAH-adapted population. Knockdown of AHR2 in naïve killifish embryos did not prevent cardiac teratogenesis. The data suggest a unique mechanism of cardiotoxicity that is not driven by AHR2 activation.
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Inhibidores Enzimáticos del Citocromo P-450/toxicidad , Familia 1 del Citocromo P450/antagonistas & inhibidores , Proteínas de Peces/agonistas , Proteínas de Peces/antagonistas & inhibidores , Fluorenos/toxicidad , Fundulidae/metabolismo , Corazón/efectos de los fármacos , Miocardio/enzimología , Hidrocarburos Policíclicos Aromáticos/toxicidad , Receptores de Hidrocarburo de Aril/agonistas , Contaminantes Químicos del Agua/toxicidad , Animales , Cardiotoxicidad , Familia 1 del Citocromo P450/metabolismo , Relación Dosis-Respuesta a Droga , Embrión no Mamífero/efectos de los fármacos , Embrión no Mamífero/enzimología , Proteínas de Peces/metabolismo , Fundulidae/embriología , Fundulidae/genética , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Ligandos , Receptores de Hidrocarburo de Aril/genética , Receptores de Hidrocarburo de Aril/metabolismo , Medición de RiesgoRESUMEN
Alpha-synuclein has long been studied due to its involvement in the progression of Parkinson's disease (PD), a common neurodegenerative disorder, although a consensus on the exact function of this protein is elusive. This protein shows remarkable structural plasticity and this property is important for both correct cellular function and pathological progression of PD. Formation of intracellular oligomeric species within the substantia nigra correlates with disease progression and it has been proposed that formation of a partially folded intermediate is key to the initiation of the fibrillisation process. Many factors can influence changes in the structure of alpha-synuclein such as disease mutations and interaction with metals and neurotransmitters. High concentrations of both dopamine and metals are present in the substantia nigra making this an ideal location for both the structural alteration of alpha-synuclein and the production of toxic oxygen species. The recent proposal that alpha-synuclein is a ferrireductase is important as it can possibly catalyse the formation of such reactive species and as a result exacerbate neurodegeneration.
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Metales/metabolismo , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Dopamina/metabolismo , Humanos , Hierro/metabolismo , Mutación/genética , Agregado de Proteínas , alfa-Sinucleína/antagonistas & inhibidoresRESUMEN
Acute exposures to some individual polycyclic aromatic hydrocarbons (PAHs) and complex PAH mixtures are known to cause cardiac malformations and edema in the developing fish embryo. However, the heart is not the only organ impacted by developmental PAH exposure. The developing brain is also affected, resulting in lasting behavioral dysfunction. While acute exposures to some PAHs are teratogenically lethal in fish, little is known about the later life consequences of early life, lower dose subteratogenic PAH exposures. We sought to determine and characterize the long-term behavioral consequences of subteratogenic developmental PAH mixture exposure in both naive killifish and PAH-adapted killifish using sediment pore water derived from the Atlantic Wood Industries Superfund Site. Killifish offspring were embryonically treated with two low-level PAH mixture dilutions of Elizabeth River sediment extract (ERSE) (TPAH 5.04 µg/L and 50.4 µg/L) at 24h post fertilization. Following exposure, killifish were raised to larval, juvenile, and adult life stages and subjected to a series of behavioral tests including: a locomotor activity test (4 days post-hatch), a sensorimotor response tap/habituation test (3 months post hatch), and a novel tank diving and exploration test (3months post hatch). Killifish were also monitored for survival at 1, 2, and 5 months over 5-month rearing period. Developmental PAH exposure caused short-term as well as persistent behavioral impairments in naive killifish. In contrast, the PAH-adapted killifish did not show behavioral alterations following PAH exposure. PAH mixture exposure caused increased mortality in reference killifish over time; yet, the PAH-adapted killifish, while demonstrating long-term rearing mortality, had no significant changes in mortality associated with ERSE exposure. This study demonstrated that early embryonic exposure to PAH-contaminated sediment pore water caused long-term locomotor and behavioral alterations in killifish, and that locomotor alterations could be observed in early larval stages. Additionally, our study highlights the resistance to behavioral alterations caused by low-level PAH mixture exposure in the adapted killifish population. Furthermore, this is the first longitudinal behavioral study to use killifish, an environmentally important estuarine teleost fish, and this testing framework can be used for future contaminant assessment.
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Adaptación Biológica/efectos de los fármacos , Embrión no Mamífero/anomalías , Desarrollo Embrionario/efectos de los fármacos , Locomoción/efectos de los fármacos , Hidrocarburos Policíclicos Aromáticos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Embrión no Mamífero/efectos de los fármacos , Ambiente , Conducta Exploratoria/efectos de los fármacos , Fundulidae , Cardiopatías Congénitas/inducido químicamente , Larva/efectos de los fármacos , Reflejo de Sobresalto/efectos de los fármacos , Estadísticas no Paramétricas , Factores de TiempoRESUMEN
We constructed a compact in situ polarized (3)He neutron spin filter based on spin-exchange optical pumping which is capable of continuous pumping of the (3)He gas while the system is in place in the neutron beam on an instrument. The compact size and light weight of the system simplifies its utilization on various neutron instruments. The system has been successfully tested as a neutron polarizer on the triple-axis spectrometer (HB3) and the hybrid spectrometer (HYSPEC) at Oak Ridge National Laboratory. Over 70% (3)He polarization was achieved and maintained during the test experiments. Over 90% neutron polarization and an average of 25% transmission for neutrons of 14.7 meV and 15 meV was also obtained.
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The contractile effects of neurotensin (NT) and cholecystokinin octapeptide (CCK-8) on isolated circular smooth muscle strips of chicken gallbladder were investigated. The NT (0.25-300 nM) produced concentration-dependent contractions on smooth muscle with an EC50 of 8.5 nM (95% confidence limits = 5.3-13.6 nM). In comparison, CCK-8 produced concentration-dependent contractions with an EC50 of 13 nM (95% confidence limits of 9-20 nM). There were no statistical differences in contractile responses when comparing NT and CCK-8 at equimolar concentrations. The NT appears to act directly on smooth muscle tissue in the chicken; the contractile responses were not blocked by 10 µM atropine or tetrodotoxin. A portion of the activity is mediated by extracellular calcium as 100 nM nifedipine inhibited 30% of peptide-induced muscle tension. The NT receptor (NTR) type 1 antagonist SR 48692 (0.1 µM) did not significantly reduce NT potency. The contractile effects of CCK-8 remained unaltered in tissues pretreated with atropine, TTX, or nifedipine. The CCK-A antagonist lorglumide, at a concentration of 1 µM, reduced the contractile potency of CCK-8 by one-half. Avian receptors for NT and CCK may differ pharmacologically from their mammalian counterparts, but their contractile actions on the gallbladder resulting in increased biliary output by flow are further evidence of their role in the postprandial regulation of lipid digestion in chickens.
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Pollos , Vesícula Biliar/anatomía & histología , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Neurotensina/farmacología , Sincalida/farmacología , Animales , Atropina/farmacología , Músculo Liso/fisiología , Nifedipino/farmacología , Receptores de Colecistoquinina/antagonistas & inhibidores , Receptores de Neurotensina/antagonistas & inhibidoresRESUMEN
The Hybrid Spectrometer (HYSPEC) is a new direct geometry spectrometer at the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is equipped with polarization analysis capability with 60° horizontal and 15° vertical detector coverages. In order to provide wide angle polarization analysis for this instrument, we have designed and built a novel polarized (3)He filling station based on the spin exchange optical pumping method. It is designed to supply polarized (3)He gas to HYSPEC as a neutron polarization analyzer. In addition, the station can optimize the (3)He pressure with respect to the scattered neutron energies. The depolarized (3)He gas in the analyzer can be transferred back to the station to be repolarized. We have constructed the prototype filling station. Preliminary tests have been carried out demonstrating the feasibility of the filling station. Here, we report on the design, construction, and the preliminary results of the prototype filling station.
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OBJECTIVE: To evaluate levels of proinflammatory cytokines and sialidase activity in aerobic vaginitis (AV) in relation to normal vaginal flora and bacterial vaginosis (BV). STUDY DESIGN: In this cross-sectional study, a total of 682 consecutive non-pregnant women attending the gynecology service were assessed and 408 women were included. Vaginal rinsing samples were collected from 223 women with microscopic finding of BV (n=98), aerobic vaginitis (n=25) and normal flora (n=100). Samples were tested for interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor (TNF)-α, and sialidase activity. RESULTS: Compared to women with normal flora, vaginal levels of IL-1ß were highly increased in both BV and AV (p<0.0001). Significantly higher vaginal IL-6 was detected in AV (p<0.0001) but not in BV, in relation to normal flora. Women with AV also presented increased IL-8 levels (p<0.001), while those with BV presented levels similar to normal flora. Sialidase was increased in BV and AV compared with the normal group (p<0.0001) but no difference in sialidase activity was observed between BV and AV. CONCLUSION: A more intense inflammatory host response occurs for AV than for BV when compared with normal flora. Furthermore, the increased sialidase activity in AV and BV indicates that both abnormal vaginal flora types can be harmful to the maintenance of a healthy vaginal environment.
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Proteínas Bacterianas/metabolismo , Membrana Mucosa/metabolismo , Neuraminidasa/metabolismo , Regulación hacia Arriba , Vagina/metabolismo , Vaginosis Bacteriana/metabolismo , Adolescente , Adulto , Bacterias Aerobias/clasificación , Bacterias Aerobias/enzimología , Bacterias Aerobias/aislamiento & purificación , Proteínas Bacterianas/aislamiento & purificación , Brasil , Estudios Transversales , Femenino , Humanos , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Persona de Mediana Edad , Tipificación Molecular , Membrana Mucosa/inmunología , Membrana Mucosa/microbiología , Neuraminidasa/aislamiento & purificación , Vagina/inmunología , Vagina/microbiología , Frotis Vaginal , Vaginosis Bacteriana/inmunología , Vaginosis Bacteriana/microbiología , Adulto JovenRESUMEN
To understand its potential to cause invasive disease, the genome of Mycoplasma canis strain PG14(T) from a dog's throat was compared to those of isolates from the genital tract or brain of dogs. The average nucleotide identity between strain pairs is 98%, and their genome annotations are similar.
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ADN Bacteriano/química , ADN Bacteriano/genética , Genoma Bacteriano , Mycoplasma/genética , Análisis de Secuencia de ADN , Animales , Encéfalo/microbiología , Perros , Datos de Secuencia Molecular , Mycoplasma/aislamiento & purificación , Infecciones por Mycoplasma/microbiología , Infecciones por Mycoplasma/veterinaria , Faringe/microbiología , Infecciones del Sistema Genital/microbiología , Infecciones del Sistema Genital/veterinariaRESUMEN
BACKGROUND: Granulomatous meningoencephalomyelitis (GME) and necrotizing meningoencephalitis (NME) are common inflammatory conditions of the central nervous system of dogs. Infectious pathogens, particularly viruses, are suspected to contribute to the etiopathogenesis of GME and NME. HYPOTHESIS: Broadly reactive PCR might aid in the identification of infectious agents in GME and NME. ANIMALS: Sixty-eight client-owned dogs evaluated by necropsy at 1 university referral hospital. METHODS: A mixed prospective/retrospective case-control study was performed. Brain tissue prospectively collected at necropsy from GME, NME, and control cases was evaluated by broadly reactive polymerase chain reaction (PCR) for adenoviruses, bunyaviruses, coronaviruses, enteroviruses, flaviviruses, herpesviruses, paramyxoviruses, and parechoviruses. In addition, these tissues were retrospectively evaluated for the presence of mycoplasmas by PCR, culture, and immunohistochemistry (IHC). RESULTS: Brain tissue was collected from 11 GME and 27 NME cases and 30 controls. Viral nucleic acids were not identified in the 6 GME cases, 25 NME cases, and 2 controls evaluated by viral PCR. Mycoplasma canis was identified by Mycoplasma genus PCR in 1/5 GME and 4/25 NME cases and subsequently was cultured from 4/5 GME and 4/8 NME cases as well as 2/9 controls. The IHC did not detect M. canis in any of the 11 GME and 27 NME cases or 14 controls evaluated with strain PG14 polyclonal antiserum. CONCLUSIONS AND CLINICAL IMPORTANCE: The negative results suggest that viral pathogens are not common in the brain tissue of dogs with GME and NME. Further investigation is warranted to determine the importance of M . canis in cases of GME and NME.
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Encéfalo/virología , Enfermedades de los Perros/virología , Meningoencefalitis/veterinaria , Animales , Encéfalo/inmunología , Estudios de Casos y Controles , ADN Viral/química , ADN Viral/genética , Enfermedades de los Perros/inmunología , Perros , Femenino , Inmunohistoquímica/veterinaria , Masculino , Meningoencefalitis/inmunología , Meningoencefalitis/virología , Estudios Prospectivos , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Estudios Retrospectivos , Análisis de Secuencia de ADNRESUMEN
Mycoplasma alligatoris and Mycoplasma crocodyli are closely related siblings, one being highly virulent and the other relatively attenuated. We compared their genomes to better understand the mechanisms and origins of M. alligatoris' remarkable virulence amid a clade of harmless or much less virulent species. Although its chromosome was refractory to closure, M. alligatoris differed most notably by its complement of sialidases and other genes of the N-acetylneuraminate scavenging and catabolism pathway.
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ADN Bacteriano/química , ADN Bacteriano/genética , Genoma Bacteriano , Mycoplasma/genética , Análisis de Secuencia de ADN , Redes y Vías Metabólicas/genética , Datos de Secuencia Molecular , Mycoplasma/patogenicidad , VirulenciaRESUMEN
The texture, or topography, interior of shells from native and exotic mollusks are measured and compared to determine if they can be discriminated. Area-scale fractal analysis is used to calculate relative areas as a function of scale, and the relative areas are used to evaluate the measurements. Measurements from a scanning laser profiler and from confocal and interferometric microscopes are compared, as are measurements of an original and a replica. The relative areas indicate clear differences between the measurement instruments. The largest relative areas are calculated from the confocal measurements. The trueness of the measurements has not been determined. However, the relative areas calculated from the confocal measurements are capable of discriminating the native clam from the exotic mussels with a confidence of greater than 99% at scales below 10 µm².
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Moluscos/anatomía & histología , Moluscos/clasificación , Animales , Biometría/métodos , Microscopía Confocal/métodos , Microscopía de Interferencia/métodos , América del Norte , Ríos , Propiedades de SuperficieRESUMEN
BACKGROUND: We report measurements of the temporal response of serum vasopressin concentrations in the period after reperfusion of the liver graft during orthotopic liver transplantation (OLT). METHODS: Vasopressin concentrations were determined in 11 adult patients undergoing OLT by radioimmunoassay of samples collected after induction, at 5 minutes prior to reperfusion, and at 10, 20, 30, 40, 50, 60, 90, and 120 minutes after reperfusion. RESULTS: Pre-incision vasopressin concentrations ranged from <0.5 to 2.6 pg/mL (reference serum vasopressin, <1.7 pg/mL). Overall, levels increased before reperfusion, but fell thereafter. Individual patients manifested elevated levels during the period after reperfusion. Values immediately before reperfusion exhibited most variability, ranging from 0.8 to 40 pg/mL (median, 15; interquartile range [IQR], 4-29) Median vasopressin concentrations 10 minutes postreperfusion were 7.6 pg/mL (IQR, 3-27). Only 3 of the 11 patients failed to generate vasopressin levels >20 pg/mL. In each of these patients, hemodynamics were satisfactory without the need for additional pressor infusion. Maximum vasopressin concentration measured in any patient was 85 pg/mL. There was no correlation between vasopressin concentration and mean blood pressure or systemic vascular resistance index. CONCLUSION: Vasopressin concentrations during OLT vary widely and are elevated periodically during the anhepatic and postreperfusion stages, with no apparent relationship between vasopressin concentrations and blood pressure. Although vasopressin concentrations were not as high as those measured during some other clinical situations, these data suggest that a relative vasopressin deficiency is not a direct cause of hypotension during OLT.