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Self-motion perception was studied in patients with unilateral vestibular lesions (UVL) due to acute vestibular neuritis at 1 wk and 4, 8, and 12 mo after the acute episode. We assessed vestibularly mediated self-motion perception by measuring the error in reproducing the position of a remembered visual target at the end of four cycles of asymmetric whole-body rotation. The oscillatory stimulus consists of a slow (0.09 Hz) and a fast (0.38 Hz) half cycle. A large error was present in UVL patients when the slow half cycle was delivered toward the lesion side, but minimal toward the healthy side. This asymmetry diminished over time, but it remained abnormally large at 12 mo. In contrast, vestibulo-ocular reflex responses showed a large direction-dependent error only initially, then they normalized. Normalization also occurred for conventional reflex vestibular measures (caloric tests, subjective visual vertical, and head shaking nystagmus) and for perceptual function during symmetric rotation. Vestibular-related handicap, measured with the Dizziness Handicap Inventory (DHI) at 12 mo correlated with self-motion perception asymmetry but not with abnormalities in vestibulo-ocular function. We conclude that 1) a persistent self-motion perceptual bias is revealed by asymmetric rotation in UVLs despite vestibulo-ocular function becoming symmetric over time, 2) this dissociation is caused by differential perceptual-reflex adaptation to high- and low-frequency rotations when these are combined as with our asymmetric stimulus, 3) the findings imply differential central compensation for vestibuloperceptual and vestibulo-ocular reflex functions, and 4) self-motion perception disruption may mediate long-term vestibular-related handicap in UVL patients.NEW & NOTEWORTHY A novel vestibular stimulus, combining asymmetric slow and fast sinusoidal half cycles, revealed persistent vestibuloperceptual dysfunction in unilateral vestibular lesion (UVL) patients. The compensation of motion perception after UVL was slower than that of vestibulo-ocular reflex. Perceptual but not vestibulo-ocular reflex deficits correlated with dizziness-related handicap.
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Adaptación Fisiológica , Propiocepción , Reflejo Vestibuloocular , Enfermedades Vestibulares , Adulto , Evaluación de la Discapacidad , Medidas del Movimiento Ocular , Lateralidad Funcional , Movimientos de la Cabeza , Humanos , Masculino , Memoria , Persona de Mediana Edad , Estimulación Física , Estudios Prospectivos , Psicofísica , Recuperación de la Función , Rotación , Enfermedades Vestibulares/fisiopatología , Percepción Visual , Adulto JovenRESUMEN
Hepatitis E represents an important public-health concern throughout the world. It is one of the leading causes of hepatitis in North Africa, Asia and the Middle East. In Tunisia, the true burden of HEV infection is still unknown. The objectives of the present study were to assess the occurrence of hepatitis E virus in Tunisia through the monitoring of urban sewage and to characterize the strains identified using molecular assays. A total of 150 sewage samples (raw and treated) were collected from three wastewater treatment plants located in the regions of Monastir and Mahdia and analyzed by nested RT-PCR using a qualitative assay targeting the methyltransferase gene in ORF1. Of these, only three samples (2 %) were found to be positive for HEV, one belonging to genotype 1 and two to genotype 3. The results of the present study indicate a low level of virus excretion among the Tunisian population. Both genotypes 1 and 3 are circulating in this country, however, possibly causing sporadic infections. The presence of the zoonotic genotype 3, known to be transmitted to humans mainly by swine and demonstrated in Tunisia for the first time in this work, raises the question of possible reservoir species, since pork products are not consumed in this country, pigs are not bred, and wild boar is not endemic. Further studies will be needed to gather information on the occurrence and diversity of HEV strains circulating among humans and animals in Tunisia, and on possible animal reservoirs.
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Virus de la Hepatitis E/genética , Virus de la Hepatitis E/aislamiento & purificación , Aguas Residuales/virología , Virus de la Hepatitis E/clasificación , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , TúnezRESUMEN
Hepatitis E is a liver disease caused by the hepatitis E virus (HEV), primarily transmitted through contaminated water or food. There are four different HEV genotypes in humans, with genotypes 1 and 2 being the most widespread. Genotypes 3 and 4 are found in animals and can also infect humans. Genotype 4 is prevalent in Asia, mainly in China. In Italy, only one outbreak of HEV-4 has been documented, which occurred in 2011, involving five patients. In 2013, HEV G4 was also detected in a pig farm. Since then, no further evidence of HEV genotype 4 has been found in the country. This study describes the first detection of HEV genotype 4, subtype d, in wastewater in central Italy, despite a lack of any clinical case reported in the area. By using a multiplex PCR protocol and two sequencing strategies, Illumina and ONT, the virus's complete genome was sequenced and characterized as subtype 4d. These findings shed light on the potential of environmental surveillance for infectious agents to improve our understanding of epidemiology and support public health efforts.
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Virus de la Hepatitis E , Humanos , Animales , Porcinos , Virus de la Hepatitis E/genética , Aguas Residuales , Genotipo , Italia/epidemiología , Genómica , FilogeniaRESUMEN
BACKGROUND: The number and projections of cancer survivors are necessary to meet the healthcare needs of patients, while data on cure prevalence, that is, the percentage of patients who will not die of cancer by time since diagnosis, are lacking. MATERIALS AND METHODS: Data from Italian cancer registries (duration of registration ranged from 9 to 40 years, with a median of 22 years) covering 47% of the population were used to calculate the limited-duration prevalence, the complete prevalence in 2018, projections to 2030, and cure prevalence, by cancer type, sex, age, and time since diagnosis. RESULTS: A total of 3 347 809 people were alive in Italy in 2018 after a cancer diagnosis, corresponding to 5.6% of the resident population. They will increase by 1.5% per year to 4 012 376 in 2030, corresponding to 6.9% of the resident population, 7.6% of women and â¼22% after age 75 years. In 2030, more than one-half of all prevalent cases (2 million) will have been diagnosed by ≥10 years. Those with breast (1.05 million), prostate (0.56 million), or colorectal cancers (0.47 million) will be 52% of all prevalent patients. Cure prevalence was 86% for all patients alive in 2018 (87% for patients with breast cancer and 99% for patients with thyroid or testicular cancer), increasing with time since diagnosis to 93% for patients alive after 5 years and 96% after 10 years. Among patients who survived at least 5 years, the excess risk of death (1 - cure prevalence) was <5% for patients with most cancer types except for those with cancers of the breast (8.3%), lung (11.1%), kidney (13.2%), and bladder (15.5%). CONCLUSIONS: Study findings encourage the implementation of evidence-based policies aimed at improving long-term clinical follow-up and rehabilitation of people living after cancer diagnosis throughout the course of the disease. Updated estimates of complete prevalence are important to enhance data-driven cancer control planning.
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Neoplasias , Humanos , Italia/epidemiología , Femenino , Masculino , Prevalencia , Neoplasias/epidemiología , Neoplasias/terapia , Anciano , Persona de Mediana Edad , Adulto , Adolescente , Adulto Joven , Niño , Anciano de 80 o más Años , Sistema de Registros , Supervivientes de Cáncer/estadística & datos numéricos , Preescolar , Lactante , Predicción , Recién NacidoRESUMEN
HBV/HCV co-infection is common in HIV-1-infected prisoners. To investigate the characteristics of HIV co-infections, and to evaluate the molecular heterogeneity of HIV, HBV and HCV in prisoners, we carried-out a multicenter cross-sectional study, including 65 HIV-1-infected inmates enrolled in 5 Italian detention centers during the period 2017-2019. HIV-1 subtyping showed that 77.1% of inmates were infected with B subtype and 22.9% with non-B subtypes. Italian nationals were all infected with subtype B (93.1%), except two individuals, one infected with the recombinant form CRF72_BF1, and the other with the HIV-1 sub-subtype A6, both previously not identified in inmates of Italian nationality. Non-Italian nationals were infected with subtype B (52.6%), CRFs (36.8%) and sub-subtypes A1 and A3 (5.2%). HIV variants carrying resistance mutations to NRTI, NNRTI, PI and InSTI were found in 7 inmates, 4 of which were never exposed to the relevant classes of drugs associated with these mutations. HBV and/or HCV co-infections markers were found in 49/65 (75.4%) inmates, while 27/65 (41.5%) showed markers of both HBV and HCV coinfection. Further, Italian nationals showed a significant higher presence of HCV markers as compared to non-Italian nationals (p = 0.0001). Finally, HCV phylogenetic analysis performed in 18 inmates revealed the presence of HCV subtypes 1a, 3a, 4d (66.6%, 16.7% and 16.7%, respectively). Our data suggest the need to monitor HIV, HBV and HCV infections in prisons in order to prevent spreading of these viruses both in jails and in the general population, and to implement effective public health programs that limit the circulation of different genetic forms as well as of viral variants with mutations conferring resistance to treatment.
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Coinfección , Seropositividad para VIH , VIH-1 , Hepatitis C , Humanos , Estudios Transversales , VIH-1/genética , Virus de la Hepatitis B/genética , Coinfección/epidemiología , Filogenia , Hepatitis C/complicaciones , Hepatitis C/epidemiología , Italia/epidemiologíaRESUMEN
The imputation of missing values in the detail data of Educational Institutions is a difficult task. These data contain multivariate time series, which cannot be satisfactory imputed by many existing imputation techniques. Moreover, almost all the data of an Institution are interconnected: the number of graduates is not independent from the number of students, the expenditure is not independent from the staff, etc. In other words, each imputed value has an impact on the whole set of data of the institution. Therefore, imputation techniques for this specific case should be designed very carefully. We describe here the methods and the codes of the imputation methodology developed to impute the various patterns of missing values which appear in similar interconnected data. In particular, a first part of the proposed methodology, called ``trend smoothing imputation'', is designed to impute missing values in time series by respecting the trend and the other features of an Institution. The second part of the proposed methodology, called ``donor imputation'', is designed to impute larger chunks of missing data by using values taken form similar Institutions in order to respect again their size and trend.â¢Trend smoothing imputation can handle missing subsequences in time series, and is given by a weighted combination of: (a) weighed average of the other available values of the sequence, and (b) linear regression.â¢Donor imputation can handle full sequence missing in time series. It imputes the Recipient Institution using the values taken from a similar institution, called Donor, selected using optimization criteria.â¢The values imputed by our techniques should respect the trend, the size and the ratios of each Institution.
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The primary function of lung surfactant is to form monolayers at the alveolar interface capable of lowering the normal surface tension to near zero. To accomplish this process, the surfactant must be capable of maintaining a coherent, tightly packed monolayer that avoids collapse during expiration. The positively charged amino-terminal peptide SP-B1-25 of lung surfactant-specific protein SP-B increases the collapse pressure of an important component of lung surfactant, palmitic acid (PA), to nearly 70 millinewtons per meter. This alteration of the PA isotherms removes the driving force for "squeeze-out" of the fatty acids from the primarily dipalmitoylphosphatidylcholine monolayers of lung surfactant. An uncharged mutant of SP-B1-25 induced little change in the isotherms, suggesting that a specific charge interaction between the cationic peptide and the anionic lipid is responsible for the stabilization. The effect of SP-B1-25 on fatty acid isotherms is remarkably similar to that of simple poly-cations, suggesting that such polymers might be useful as components of replacement surfactants for the treatment of respiratory distress syndrome.
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Proteolípidos/fisiología , Surfactantes Pulmonares/fisiología , 1,2-Dipalmitoilfosfatidilcolina/química , Ácidos Eicosanoicos/química , Humanos , Ácido Palmítico , Ácidos Palmíticos/química , Fragmentos de Péptidos/química , Proteolípidos/química , Surfactantes Pulmonares/química , Tensión Superficial , TermodinámicaAsunto(s)
Brotes de Enfermedades , Contaminación de Alimentos/estadística & datos numéricos , Fragaria/virología , Virus de la Hepatitis A Humana/aislamiento & purificación , Hepatitis A/epidemiología , Alimentos Marinos/virología , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Niño , Preescolar , Notificación de Enfermedades , Femenino , Hepatitis A/transmisión , Hepatitis A/virología , Virus de la Hepatitis A Humana/genética , Humanos , Incidencia , Italia/epidemiología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/genética , Estudios Retrospectivos , Análisis de Secuencia de ADN , Adulto JovenRESUMEN
BACKGROUND: Alexithymia refers to a set of cognitive and emotional deficits. Its effect on surgical outcome has been demonstrated but no studies have been published on colorectal cancer patients. STUDY DESIGN: A series of 60 consecutive colorectal cancer patients were enrolled in a 3-year prospective study on quality of life by using the SF-36 test and Toronto Alexithymia Scale questionnaires. Patients were investigated pre- and postoperatively (before discharge and then 1 and 3 months thereafter). The control group consisted of patients undergoing laparoscopic cholecystectomy for cholelithiasis. These two groups were divided into two subsets: high-level alexithymia (HA) and low-level alexithymia (LA). The prevalence of HA was 34% in colorectal patients and 35% in cholelithiasis patients. RESULTS: During the postoperative period, in the colorectal group the SF-36 score was significantly higher in HA than in LA subsets. This result was confirmed in the cholelithiasis group. During follow-up, a progressive reduction of the SF-36 score was observed in both HA populations. DISCUSSION: Results emerging from this investigation demonstrate that surgery significantly improves the quality of life in HA patients. These findings suggest that alexithymia might be advantageous in evaluating the adaptation after surgery in the short follow-up period.
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Síntomas Afectivos/psicología , Neoplasias Colorrectales/psicología , Neoplasias Colorrectales/cirugía , Calidad de Vida , Anciano , Colecistectomía Laparoscópica , Colelitiasis/psicología , Colelitiasis/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosAsunto(s)
Brotes de Enfermedades/prevención & control , Monitoreo Epidemiológico , Microbiología de Alimentos/tendencias , Alimentos Congelados/virología , Frutas/virología , Hepatitis A/epidemiología , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Hepatitis A/diagnóstico , Hepatitis A/virología , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVE: Aim of this study was to evaluate the prevalence of alexithymia in patients affected by SLE or RA and to investigate the correlation between alexithymia and immunoendocrine parameters (PRL, hGH, IL-6 and TNF-alfa). METHODS: Twenty-five patients (12 and 13 affected by SLE and RA, respectively) were enrolled into the study. The Toronto Alexithymia Scale-20 (TAS-20) was administered. PRL, hGH, IL-6 and TNF-alfa levels were measured by commercially available ELISA kits. RESULTS: Alexithymia prevalence (TAS-20 > or = 51) was 54% in RA and 42% in SLE patients. hGH serum levels were 3.1+/-4.2 and 1.1+/-0.9 IU/ml in SLE and RA, respectively. PRL concentration was 18.4+/-6.5 ng/ml and 14.2+/-4.0 ng/ml in SLE and RA patients, respectively (p=0.03). In RA group, TNF-alpha was 20+/-36.2 whereas in SLE it was 4.9+/-12.8 pg/ml (p=0.03); IL-6 serum concentrations were 24.4+/-25.1 and 2.9+/-5.4 pg/ml, in RA and SLE respectively (p=0.004). The serum level of hGH showed slight increase in alexithymic group (A) compared to non alexithymic group (NA) in both SLE and RA patients. PRL serum levels in SLE-A patients was 26.7+/-17.3 ng/ml while in SLE-NA patients was 12.4+/-3.3 ng/ml (p=0.04). In RA patients increased values of IL-6 and TNF-alpha were present in the A group compared to NA group (IL-6: 35.3+/-28 pg/mL vs 3.5+/-3.9 pg/mL, p=0.01; TNF-alpha: 34.7+/-39 pg/mL vs 3.1+/-3.4 pg/mL, p=0.01). CONCLUSIONS: In this preliminary results we found an high prevalence of alexithymia and a correlation between immunoendocrine parameters and alexhytimic features in SLE and RA, suggesting that an immunomodulatory pathway could influence this cognitive style in patients with autoimmune disorders. Other studies should contribute to find a common biological pathway linking alexithymia and autoimmunity.
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Síntomas Afectivos/epidemiología , Síntomas Afectivos/etiología , Artritis Reumatoide/complicaciones , Lupus Eritematoso Sistémico/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Persona de Mediana Edad , PrevalenciaRESUMEN
The need for a time-resolved monochromatic x-ray imaging diagnostic at photon energies >15 keV has motivated the development of a Wolter optic to study x-ray sources on the Z-machine at Sandia National Laboratories. The work is performed in both the LLNL's x-ray calibration facility and SNL's micro-focus x-ray lab. Characterizations and calibrations include alignment, measurement of throughput within the field of view (FOV), the point-spread function within the FOV both in and out of focus, and bandpass in the FOV. These results are compared with ray tracing models, showing reasonable agreement.
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A facility to calibrate x-ray imaging optics was built at Lawrence Livermore National Laboratory to support high energy density (HED) and inertial confinement fusion (ICF) diagnostics such as those at the National Ignition Facility and the Sandia Z-Machine. Calibration of the spectral reflectivity and resolution of these x-ray diagnostics enable absolute determination of the x-ray flux and wavelengths generated in the HED and ICF experiments. Measurement of the optic point spread function is used to determine spatial resolution of the optic. This facility was constructed to measure (1) the x-ray reflectivity to ±5% over a spectral range from 5 to 60 keV; (2) point spread functions with a resolution of 50 µm (currently) and 13 µm (future) in the image plane; and (3) optic distance relative to the x-ray source and detector to within ±100 µm in each dimension. This article describes the capabilities of the calibration facility, concept of operations, and initial data from selected x-ray optics.
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Recent breakthroughs in the fabrication of small-radii Wolter optics for astrophysics allow high energy density facilities to consider such optics as novel x-ray diagnostics at photon energies of 15-50 keV. Recently, the Lawrence Livermore National Laboratory, Sandia National Laboratories (SNL), the Smithsonian Astrophysical Observatory, and the NASA Marshall Space Flight Center jointly developed and fabricated the first custom Wolter microscope for implementation in SNL's Z machine with optimized sensitivity at 17.5 keV. To achieve spatial resolution of order 100-200 microns over a field of view of 5 × 5 × 5 mm3 with high throughput and narrow energy bandpass, the geometry of the optic and its multilayer required careful design and optimization. While the geometry mainly influences resolution and the field of view of the diagnostic, the mirror coating determines the spectral response and throughput. Here we outline the details of the design and fabrication process for the first multilayer-coated Wolter I optic for SNL's Z machine (Z Wolter), including its W/Si multilayer, and present results of raytrace simulations completed to predict and verify the performance of the optic.
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A new Wolter x-ray imager has been developed for the Z machine to study the emission of warm (>15 keV) x-ray sources. A Wolter optic has been adapted from observational astronomy and medical imaging, which uses curved x-ray mirrors to form a 2D image of a source with 5 × 5 × 5 mm3 field-of-view and measured 60-300-µm resolution on-axis. The mirrors consist of a multilayer that create a narrow bandpass around the Mo Kα lines at 17.5 keV. We provide an overview of the instrument design and measured imaging performance. In addition, we present the first data from the instrument of a Mo wire array z-pinch on the Z machine, demonstrating improvements in spatial resolution and a 350-4100× increase in the signal over previous pinhole imaging techniques.
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Hepatitis E virus (HEV) is an emergent causative agent of acute hepatitis, transmitted by fecal-oral route. Infection with HEV is a global cause for morbidity and mortality throughout the world: it mainly causes large outbreaks in endemic areas and sporadic autochthonous cases in industrialized countries where HEV infections seem to be an emergent zoonotic disease. Infection of porcine livestock and its relationship with the human cases have been demonstrated. The present study describes an investigation on the prevalence and diversity of HEV in pig slurry in Italy. Slurry samples (24) were collected from ten farms located in North Italy during 2015 and analyzed for HEV, using four broad-range nested PCR assays targeting ORF1 (MTase), ORF2 (capsid) genes, and ORF2/3 regions. Overall, 18 samples (75%) were positive for HEV RNA, and characterized as genotype 3. Nine samples could be subtyped by ORF2 sequencing: Eight belonged to subtype 3f, while one sequence could not be characterized by blast analysis and phylogenetic analysis and may actually represent a new subtype. Furthermore, similarity of 99% was found between 3f Italian HEV sequences of human and swine origins. Real-Time PCR assay was also performed, in order to obtain quantitative data on positive samples. Two swine slurry samples were positive, containing 600 and 1000 UI per mL of sewage. The results of this study show that HEV strains belonging to zoonotic genotype 3 are widely present in swine excreta, and have high degree of identity with strains detected in autochthonous HEV cases. Improving swine farming operations safety and increasing operators' awareness of the zoonotic potential connected with the handling of swine effluents turn out to be key points in order to reduce the environmental and sanitary problem represented by the possible dissemination of HEV to water bodies.
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Heces/virología , Virus de la Hepatitis E/aislamiento & purificación , Hepatitis E/veterinaria , Enfermedades de los Porcinos/virología , Animales , Genotipo , Hepatitis E/virología , Virus de la Hepatitis E/clasificación , Virus de la Hepatitis E/genética , Italia , Sistemas de Lectura Abierta , Filogenia , PorcinosRESUMEN
Alexithymia is conceptualized as a disorder of emotion regulation mechanisms, which involves a dissociation of emotional and physical responses to life events and bodily sensations. Our results might suggest a possible relationship between the alexithymic construct and TNF levels in RA patients. These preliminary findings corroborate the integrated bidirectional interactions between neuropsychological mechanisms and the neuroendocrine-immune system in patients affected by autoimmune diseases and contribute to finding a common biological pathway linking alexithymia and autoimmune-inflammatory diseases.
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Síntomas Afectivos/sangre , Síntomas Afectivos/inmunología , Enfermedades Autoinmunes/sangre , Enfermedades Autoinmunes/inmunología , Sistemas Neurosecretores/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Síntomas Afectivos/complicaciones , Síntomas Afectivos/diagnóstico , Enfermedades Autoinmunes/complicaciones , Enfermedades Autoinmunes/diagnóstico , Niño , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Essential oils extracted from different plants (Anthemis nobilis L., Artemisia dracunculus L., Cannabis sativa L., Cupressus sempervirens L., Cymbopogon citratus (DC.) Stapf., Curcuma longa L., Foeniculum vulgare L., Hypericum perforatum L., Hyssopus officinalis L., Mentha spicata L., Monarda didyma L., Ocimum basilicum L., Ocotea quixos Kosterm., Origanum vulgare L., Pinus nigra J.F. Arnold, Pinus silvestris L., Piper crassinervium Kunth., Rosmarinus officinalis L., Salvia officinalis L., Salvia sclarea L., Santolina chamaecyparissus L., Thymus vulgaris L., Zingiber officinaie L.) were screened in guinea pig and rat plasma in order to assess antiplatelet activity and inhibition of clot retraction. The oils were chemically analysed and a relationship between components and ability to affect hemostasis was evidenced. O. quixos, F. vulgaris, and A. dracunculus showed the highest antiplatelet activity against ADP, Arachidonic Acid and the Thromboxane A2 agonist U46619 (IC50, 4-132 microg ml(-1)), and a good ability to destabilize clot retraction (IC50, 19-180 microg ml(-1)). For these oils a significant correlation between antiplatelet potency and phenylpropanoids content (54-86%) was evidenced thus suggesting a key role for this moiety in the prevention of clot formation. These findings provide the rationale to take in account the antiplatelet activity in the pharmacological screening of natural products containing phenylpropanoids.
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Plaquetas/fisiología , Aceites Volátiles/farmacología , Fenilpropionatos/análisis , Aceites de Plantas/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Animales , Plaquetas/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Cobayas , Masculino , Aceites Volátiles/química , Fenilpropionatos/farmacología , Aceites de Plantas/química , Ratas , Ratas WistarRESUMEN
The respiratory distress syndrome of premature infants is caused by both surfactant deficiency and surfactant inhibition by capillary-alveolar leakage of serum factors. Dispersions of a standard surfactant lipid mixture, with and without various synthetic peptides, modeled on human surfactant proteins SP-B (residues 1-25, 49-66, 1-78) and SP-C (residues 1-10), were evaluated for inhibition by serum and by plasma constituents using a pulsating bubble surfactometer. Inhibition was derived from the changes in surface properties of these mixtures after addition of human serum or plasma constituents. Modified bovine surfactant (TA) containing native SP-B and SP-C was used as a control. In the absence of serum inhibitors, mixtures with synthetic peptides gave results similar to surfactant TA. However, inhibition was more evident in the dispersions with synthetic peptides when compared with surfactant TA. The peptide/phospholipid mixture with the entire sequence of SP-B and the first 10 residues of SP-C were more resistant to inhibition than mixtures with synthetic peptides containing fewer domains. Addition of calcium reduced the inhibitory effects of serum both in mixtures containing synthetic peptides and in surfactant TA. Therefore, synthetic SP-B and SP-C peptides in surfactant lipids, in cooperation with calcium, permit resistance to inhibition by several plasma constituents that probably inactivate surfactant by a variety of different mechanisms.
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Fenómenos Fisiológicos Sanguíneos , Proteolípidos/antagonistas & inhibidores , Surfactantes Pulmonares/antagonistas & inhibidores , Adulto , Secuencia de Aminoácidos , Calcio/farmacología , Humanos , Datos de Secuencia Molecular , Fragmentos de Péptidos/antagonistas & inhibidores , Fragmentos de Péptidos/síntesis química , Fosfolípidos/metabolismo , Proteolípidos/síntesis química , Surfactantes Pulmonares/síntesis química , Propiedades de SuperficieRESUMEN
To clarify perinatal transformations of surfactant we performed lung lavage in term fetuses and in 0-24-h-old newborn rabbits. Lavage fluid was separated into three pools, namely lavage pellet, lavage supernatant and cells. We found that at birth the pellet contains 94.1 +/- 1.4% (S.E.) saturated phosphatidylcholine, while the supernatant and cells contain traces of it. At birth the pellet contains secreted lamellar bodies while the supernatant lacks any recognizable structure. After birth, the alveolar saturated phosphatidylcholine level increases 5.1-times in 24 h, the proportions between pools reaching adult values in 90 min (pellet = 75.9 + 4.8%, supernatant = 22.7 +/- 4.9%), and small vesicles appear in the supernatant, probably originating from the turnover of alveolar surfactant during breathing. The saturated phosphatidylcholine associated with cells remains unchanged. At birth, the 32-38 kDa surfactant apolipoprotein appears to be less extensively sialylated than in adult life.