119 research outputs found
Synthetic X-ray emission from white dwarf accreting planetary material
The emission of hard X-rays associated with white dwarfs (WD) can be
generated by the presence of a stellar companion either by the companion's
coronal emission or by an accretion disk formed by material stripped from the
companion. Recent studies have suggested that a Jupiter-like planet can also be
donor of material whose accretion onto the WD can generate hard X-rays. We use
the {\sc guacho} code to reproduce the conditions of this WD-planet scenario.
With the example of the hard X-ray WD KPD\,0005+5106, we explore different
terminal wind velocities and mass-loss rates of a donor planet for a future
network of simulations to investigate the luminosity and the spectral and
temporal properties of the hard X-ray emission in WD-planet systems. Our
simulations show that the material stripped from the planet forms a disk and
accretes onto the WD to reach temperatures high enough to generate hard X-rays
as usually seen in X-ray binaries with low-mass companions. For high terminal
wind velocities, the planet material does not form a disk, but it rather
accretes directly onto the WD surface. The simulations reproduce the X-ray
luminosity of another X-ray accreting WD (G\,2938), and only for some times
reaches the hard X-ray luminosity of KPD\,0005+5106. The X-ray variability is
stochastic and does not reproduce the period of KPD\,0005+5106, suggesting that
additional physical processes (e.g., hot spots resulting from magnetic
channelling of the accreting material) need to be explored.Comment: 16 pages, 13 figure
Ovulation failure in a Colombian Paso fino Mare : A combined antihomotoxic homeopathic therapy and hormonal treatment. A case report
ABSTRACT: Ovulation failure is one of the most frequent causes of infertility in mares. In the present case we
report a six-year-old Colombian Paso Fino maiden Mare that was attended for breeding purposes with a
previous history of ovulation failure. At ultrasound (US) examination of the reproductive tract and ovaries
the left ovary measured 15 x 13 cm and a pathologic 13 x 11 cm diameter anecoic structure was diagnosed.
The right ovary was found of normal size, and the uterus was found flacid. An anti homotoxic theraphy
with Ovarium compositum®, Damiana injeel®, Cerebrum compositum®, and Phosphor hommacord® for
1½ months and FK (neural) therapy (twice/15 days) were then established, the ovary size was reduced,
and softening of the follicular wall and a slight uterine response were observed. After 1½ month, the left
ovary had 13 x 11 cm diameter and showed a 9 x 8 cm follicle, whereas the right ovary was multifollicular.
Serum progesterone, estradiol and testosterone levels were those characteristics of an anestrous mare.
The mare was treated with hCG (3.000 UI, i.v./3 days) and 4 days later a corpus luteum was diagnosed
by US in the left ovary and serum progesterone levels raised to 14.91 ng/dl. At day 7 after hCG treatment
the mare was given PGF2α (9 μg/kg/for two days) intramuscular, estrous was evident 5 days later, and
artificial insemination (AI) with fertile semen was practiced resulting in a viable pregnancy as evaluated
by ultrasound at day 20; however, this pregnancy was lost at 40 days after AI. The mare returned to estrus
20 days later, she was then inseminated and the resulting pregnancy was confirmed at day 20th resulting
in a successful gestation and foaling of a full term viable foal. This report suggests hormonal therapy and
alternative medicine could be successfully combined for treatment of specific ovarian pathologies in mares.RESUMEN: La falla ovulatoria es una de las principales causas de infertilidad en yeguas cíclicas. En el presente
caso, se describe el seguimiento de una yegua nulípara de paso fino colombiano de seis años que ingresó
a consulta para ser sometida a reproducción. Al examen ecográfico se le halló el ovario izquierdo de 15
x 13 cm con una estructura patológica de aspecto anecóico y contenido líquido de 13 x 11 cm, el ovario
derecho sin estructuras y el útero flácido. La yegua fue sometida a tratamiento con antihomotóxicos del
tipo Ovarium compositum®, Damiana injeel®, Cerebrum compositum®, y Phosphor hommacord® durante
1½ mes, y terapia FK (terapia neural, dos en 15 días), lo cual disminuyó el tamaño del folículo y del
ovario, indujo ablandamiento de la pared folicular y leve respuesta uterina. Un mes y medio después,
el ovario izquierdo tenía 13 x 11 cm y un folículo de 9 x 8 cm, y el ovario derecho estaba multifolicular.
Las concentraciones de progesterona, estradiol y testosterona eran características de anestro. La yegua
fue tratada con eCG (3.000 UI/3 días, i.v.), cuatro días después la progesterona ascendió a 14.91 ng/
dl, el examen ecográfico reveló un cuerpo lúteo en el ovario izquierdo y a los siete días fue tratada con
PGF2α (9 μg/kg/2 días) intramuscular. Cinco días después la yegua presentó estro, fue inseminada y tuvo
una gestación que perdió a los 40 días; luego presentó un nuevo estro a los 20 días, fue inseminada, se
le confirmó gestación a los 20 días y tuvo una gestación a término con un potro viable al momento del parto. Este caso sugiere la posibilidad de combinar terapia hormonal con medicina alternativa para el
tratamiento de algunos tipos de anormalidades en el funcionamiento ovárico en las yeguas
Patient knowledge of fecal calprotectin in inflammatory bowel disease (IBD) : an observational study in Mexico
Background: Fecal calprotectin (FC) can be a valuable tool to optimize health care for patients with inflammatory bowel disease (IBD). The objective of this observational study was to determine the level of knowledge of the FC test in Mexican patients with IBD.
Methods: A self-report questionnaire was distributed via Facebook to patients with IBD. The survey consisted of 15 questions in two categories: the first category assessed knowledge of IBD diagnosis, and the second category assessed knowledge of the FC test.
Results: In total, 460 patients with IBD participated, of which 83.9% (386) had ulcerative colitis (UC) and 16.0% (74) had Crohn’s disease (CD). Regarding IBD diagnosis, 41.9% of participants stated that they did not know of a non-invasive test for fecal matter to identify inflammation of the colon. Regarding the FC test, 57.5% (UC) and 58.1% (CD) stated that they did not know about the test. Additionally, 65.8% (UC) and 51.3% (CD) of participants stated that they had never received the FC test and 82.6% (UC) and 77.0% (CD) recognized that the FC test was difficult to access in their medical practice. Furthermore, 66% (UC) and 52.7% (CD) of participants noted that their specialist doctor had never suggested the FC test to them, yet 89.1% (UC) and 87.8% (CD) stated that they would prefer FC analysis for their IBD follow-up assessments.
Conclusions: There is little knowledge of the FC biomarker among Mexican patients with IBD. This suggests the need for greater dissemination of its use and scope as a biomarker in IBD
Tailoring 3D single-walled carbon nanotubes anchored to indium tin oxide for natural cellular uptake and intracellular sensing.
The ability to monitor intracellular events in real time is paramount to advancing fundamental biological and clinical science. We present the first demonstration of a direct interface of vertically aligned single-walled carbon nanotubes (VASWCNTs) with eukaryotic cells, RAW 264.7 mouse macrophage cell line. The cells were cultured on indium tin oxide with VASWCNTs. VASWCNTs entered the cells naturally without application of any external force and were shown to sense the intracellular presence of a redox active moiety, methylene blue. The technology developed provides an alluring platform to enable electrochemical study of an intracellular environment
Gut dysbiosis and clinical phases of pancolitis in patients with ulcerative colitis
Ulcerative colitis (UC) is a frequent type of inflammatory bowel disease, characterized by periods of remission and exacerbation. Gut dysbiosis may influence pathophysiology and clinical response in UC. The purpose of this study was to evaluate whether gut microbiota is related to the active and remission phases of pancolitis in patients with UC as well as in healthy participants. Fecal samples were obtained from 18 patients with UC and clinical‐endoscopic evidenced pancolitis (active phase n = 9 and remission phase n = 9), as well as 15 healthy participants. After fecal DNA extraction, the 16S rRNA gene was amplified and sequenced (Illumina MiSeq), operational taxonomic units were analyzed with the QIIME software. Gut microbiota composition revealed a higher abundance of the phyla Proteobacteria and Fusobacteria in active pancolitis, as compared with remission and healthy participants. Likewise, a marked abundance of the genus Bilophila and Fusobacteria were present in active pancolitis, whereas a higher abundance of Faecalibacterium characterized both remission and healthy participants. LEfSe analysis showed that the genus Roseburia and Faecalibacterium were enriched in remission pancolitis, and genera Bilophila and Fusobacterium were enriched in active pancolitis. The relative abundance of Fecalibacterium and Roseburia showed a higher correlation with fecal calprotectin, while Bilophila and Fusobacterium showed AUCs (area under the curve) of 0.917 and 0.988 for active vs. remission pancolitis. The results of our study highlight the relation of gut dysbiosis with clinically relevant phases of pancolitis in patients with UC. Particularly, Fecalibacterium, Roseburia, Bilophila, and Fusobacterium were identified as genera highly related to the different clinical phases of pancolitis
Mollicutes antibiotic resistance profile and presence of genital abnormalities in couples attending an infertility clinic.
OBJECTIVE: The present study aimed to identify Mollicutes infection in the reproductive system. We also examined the microbiological, biochemical, and antimicrobial profiles of Mollicutes infection, which are potentially associated with clinical reproductive abnormalities causing infertility in couples. METHODS: Thirty-seven couples who were attending an infertility clinic were enrolled. Detection of genital mycoplasmas was performed in cervicovaginal samples or male urethral swabs. Microbiological culture and biochemical and antimicrobial profiles were characterized using a Mycoplasma kit. The results were associated with reproductive abnormalities, as assessed by medical specialists from the infertility clinic. RESULTS: Up to 28.3% of all biological samples (n = 74) showed positive cultures. Bacterial isolates were Ureaplasma urealyticum (71.4%), Mycoplasma hominis (9.5%), or coinfections (19%). Most Mollicutes showed significant resistance to fluoroquinolones, macrolides, and tetracycline; and showed susceptibility to doxycycline, josamycin, and pristinamycin. The presence of resistant strains to any antibiotic was significantly associated with genital abnormalities (χ2 test, relative risk = 11.38 [95% confidence interval: 5.8-22.9]), particularly in women. The highest statistical association was found for macrolide-resistant strains. CONCLUSION: The microbiological antibiotic resistance profile is epidemiologically associated with abnormalities of the reproductive system in couples attending an infertility clinic
Isolation and Characterization of Human Trophoblast Side-Population (SP) Cells in Primary Villous Cytotrophoblasts and HTR-8/SVneo Cell Line
Recently, numerous studies have identified that immature cell populations including stem cells and progenitor cells can be found among “side-population” (SP) cells. Although SP cells isolated from some adult tissues have been reported elsewhere, isolation and characterization of human trophoblast SP remained to be reported. In this study, HTR-8/SVneo cells and human primary villous cytotrophoblasts (vCTBs) were stained with Hoechst 33342 and SP and non-SP (NSP) fractions were isolated using a cell sorter. A small population of SP cells was identified in HTR-8/SVneo cells and in vCTBs. SP cells expressed several vCTB-specific markers and failed to express syncytiotrophoblast (STB) or extravillous cytotrophopblast (EVT)-specific differentiation markers. SP cells formed colonies and proliferated on mouse embryonic fibroblast (MEF) feeder cells or in MEF conditioned medium supplemented with heparin/FGF2, and they also showed long-term repopulating property. SP cells could differentiate into both STB and EVT cell lineages and expressed several differentiation markers. Microarray analysis revealed that IL7R and IL1R2 were exclusively expressed in SP cells and not in NSP cells. vCTB cells sorted as positive for both IL7R and IL1R2 failed to express trophoblast differentiation markers and spontaneously differentiated into both STB and EVT in basal medium. These features shown by the SP cells suggested that IL7R and IL1R2 are available as markers to detect the SP cells and that vCTB progenitor cells and trophoblast stem cells were involved in the SP cell population
Invasive Extravillous Trophoblasts Restrict Intracellular Growth and Spread of Listeria monocytogenes
Listeria monocytogenes is a facultative intracellular bacterial pathogen that can infect the placenta, a chimeric organ made of maternal and fetal cells. Extravillous trophoblasts (EVT) are specialized fetal cells that invade the uterine implantation site, where they come into direct contact with maternal cells. We have shown previously that EVT are the preferred site of initial placental infection. In this report, we infected primary human EVT with L. monocytogenes. EVT eliminated ∼80% of intracellular bacteria over 24-hours. Bacteria were unable to escape into the cytoplasm and remained confined to vacuolar compartments that became acidified and co-localized with LAMP1, consistent with bacterial degradation in lysosomes. In human placental organ cultures bacterial vacuolar escape rates differed between specific trophoblast subpopulations. The most invasive EVT—those that would be in direct contact with maternal cells in vivo—had lower escape rates than trophoblasts that were surrounded by fetal cells and tissues. Our results suggest that EVT present a bottleneck in the spread of L. monocytogenes from mother to fetus by inhibiting vacuolar escape, and thus intracellular bacterial growth. However, if L. monocytogenes is able to spread beyond EVT it can find a more hospitable environment. Our results elucidate a novel aspect of the maternal-fetal barrier
Lo glocal y el turismo. Nuevos paradigmas de interpretación.
El estudio del turismo se realiza desde múltiples escalas y enfoques, este libro aborda muchos temas que es necesario discutir desde diversas perspectivas; es el caso de la reflexión sobre la propia disciplina y sus conceptos, así como los asuntos específicos referidos al impacto territorial, los tipos de turismo, las cuestiones ambientales, el tema de la pobreza, la competitividad, las políticas públicas, el papel de las universidades, las áreas naturales protegidas, la sustentabilidad, la cultura, el desarrollo, la seguridad, todos temas centrales documentados y expuestos con originalidad y dominio del asunto. Lo multiescalar es básico para la comprensión del sistema turístico, sistema formado de procesos globales, regionales y locales. El eje de discusión del libro es lo glocal, esa interacción entre lo nacional y local con lo global
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