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1.
BMC Vet Res ; 19(1): 90, 2023 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-37481518

RESUMO

BACKGROUND: Intervertebral disc herniation (IVDH) is one of the most common causes of spinal cord injury (SCI) in dogs. As a result of acute SCI, a complex inflammatory response occurs in the spinal cord. Th17 cells (Th17) produce pro-inflammatory cytokines, while regulatory T cells (Treg) have opposite effects producing anti-inflammatory cytokines. Therefore, the aim of this study was to determine whether Th17- and Treg cells are involved in the pathogenesis of SCI or whether cellular changes occur due to coexisting inflammatory diseases. We hypothesized that chronic alterations in the Th17/Treg ratio are associated with a worse outcome after SCI. METHODS: Twenty-six paretic or plegic dogs with IVDH with and without coexisting inflammatory disease were investigated in the acute stage of the disease and after recovery of SCI. In addition, a healthy control group was included (n = 14). Quantification of Th17 and Treg cells, from peripheral blood samples, was performed by multicolor flow cytometry and IL17 was measured using an enzyme-linked immunosorbent assay (ELISA). RESULTS: After recovery significantly higher levels of Th17 (p = 0.0265) and Treg cells (p = 0.00025) were detected compared to acute IVDH but Th17/Treg ratio did not differ significantly. Recovered dogs and the control group did not differ significantly from each other. No association between an imbalance in the ratio and neurologic severity or underlying inflammatory diseases was found. CONCLUSION: This study demonstrated that altered Th17 and Treg levels in peripheral blood are altered in the acute stage of IVDH, preexisting inflammatory diseases seem not to influence these cell populations. Th17 and Treg cells could be considered when evaluating new treatment strategies for SCI.


Assuntos
Doenças do Cão , Deslocamento do Disco Intervertebral , Traumatismos da Medula Espinal , Cães , Animais , Linfócitos T Reguladores , Deslocamento do Disco Intervertebral/veterinária , Células Th17 , Traumatismos da Medula Espinal/veterinária , Citocinas
2.
Nature ; 529(7586): 368-72, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26760209

RESUMO

Although water vapour is the main species observed in the coma of comet 67P/Churyumov-Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far. The nucleus of 67P/Churyumov-Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and organic-rich material. Here we report the identification at infrared wavelengths of water ice on two debris falls in the Imhotep region of the nucleus. The ice has been exposed on the walls of elevated structures and at the base of the walls. A quantitative derivation of the abundance of ice in these regions indicates the presence of millimetre-sized pure water-ice grains, considerably larger than in all previous observations. Although micrometre-sized water-ice grains are the usual result of vapour recondensation in ice-free layers, the occurrence of millimetre-sized grains of pure ice as observed in the Imhotep debris falls is best explained by grain growth by vapour diffusion in ice-rich layers, or by sintering. As a consequence of these processes, the nucleus can develop an extended and complex coating in which the outer dehydrated crust is superimposed on layers enriched in water ice. The stratigraphy observed on 67P/Churyumov-Gerasimenko is therefore the result of evolutionary processes affecting the uppermost metres of the nucleus and does not necessarily require a global layering to have occurred at the time of the comet's formation.


Assuntos
Meio Ambiente Extraterreno/química , Gelo/análise , Meteoroides , Difusão , Gases/análise , Gases/química , Análise Espectral
3.
Nature ; 523(7560): 308-12, 2015 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-26153863

RESUMO

Surface polysaccharides are important for bacterial interactions with multicellular organisms, and some are virulence factors in pathogens. In the legume-rhizobium symbiosis, bacterial exopolysaccharides (EPS) are essential for the development of infected root nodules. We have identified a gene in Lotus japonicus, Epr3, encoding a receptor-like kinase that controls this infection. We show that epr3 mutants are defective in perception of purified EPS, and that EPR3 binds EPS directly and distinguishes compatible and incompatible EPS in bacterial competition studies. Expression of Epr3 in epidermal cells within the susceptible root zone shows that the protein is involved in bacterial entry, while rhizobial and plant mutant studies suggest that Epr3 regulates bacterial passage through the plant's epidermal cell layer. Finally, we show that Epr3 expression is inducible and dependent on host perception of bacterial nodulation (Nod) factors. Plant-bacterial compatibility and bacterial access to legume roots is thus regulated by a two-stage mechanism involving sequential receptor-mediated recognition of Nod factor and EPS signals.


Assuntos
Lipopolissacarídeos/metabolismo , Lotus/metabolismo , Lotus/microbiologia , Proteínas de Plantas/metabolismo , Receptores de Superfície Celular/metabolismo , Rhizobium/metabolismo , Simbiose , Sequência de Aminoácidos , Sequência de Carboidratos , Lipopolissacarídeos/química , Lotus/genética , Dados de Sequência Molecular , Mutação/genética , Fenótipo , Epiderme Vegetal/metabolismo , Epiderme Vegetal/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Nodulação , Proteínas Quinases/química , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Estrutura Terciária de Proteína , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Nódulos Radiculares de Plantas/metabolismo , Nódulos Radiculares de Plantas/microbiologia , Transdução de Sinais , Especificidade da Espécie , Supressão Genética/genética
4.
Ann Oncol ; 30(10): 1647-1652, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31373348

RESUMO

BACKGROUND: A previous analysis of 113 National Comprehensive Cancer Network® (NCCN®) recommendations reported that NCCN frequently recommends beyond Food and Drug Administration (FDA)-approved indications (44 off-label recommendations) and claimed that the evidence for these recommendations was weak. METHODS: In order to determine the strength of the evidence, we carried out an in-depth re-analysis of the 44 off-label recommendations listed in the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). RESULTS: Of the 44 off-label recommendations, 14 were later approved by the FDA and/or are supported by randomized controlled trial (RCT) data. In addition, 13 recommendations were either very minor extrapolations from the FDA label (n = 8) or were actually on-label (n = 5). Of the 17 remaining extrapolations, 8 were for mechanism-based agents applied in rare cancers or subsets with few available treatment options (median response rate = 43%), 7 were based on non-RCT data showing significant efficacy (>50% response rates), and 2 were later removed from the NCCN Guidelines because newer therapies with better activity and/or safety became available. CONCLUSION: Off-label drug use is a frequent component of care for patients with cancer in the United States. Our findings indicate that when the NCCN recommends beyond the FDA-approved indications, the strength of the evidence supporting such recommendations is robust, with a significant subset of these drugs later becoming FDA approved or supported by RCT. Recommendations without RCT data are often for mechanism-based drugs with high response rates in rare cancers or subsets without effective therapies.


Assuntos
Antineoplásicos/uso terapêutico , Aprovação de Drogas , Medicina Baseada em Evidências , Neoplasias/tratamento farmacológico , Uso Off-Label/normas , Administração dos Cuidados ao Paciente/normas , Guias de Prática Clínica como Assunto/normas , Humanos , Neoplasias/patologia , Uso Off-Label/legislação & jurisprudência , Uso Off-Label/estatística & dados numéricos , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Estados Unidos , United States Food and Drug Administration
5.
Ann Oncol ; 29(2): 352-360, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29069303

RESUMO

Background: Genomic aberrations have been identified in metastatic castration-resistant prostate cancer (mCRPC), but molecular predictors of resistance to abiraterone acetate/prednisone (AA/P) treatment are not known. Patients and methods: In a prospective clinical trial, mCRPC patients underwent whole-exome sequencing (n = 82) and RNA sequencing (n = 75) of metastatic biopsies before initiating AA/P with the objective of identifying genomic alterations associated with resistance to AA/P. Primary resistance was determined at 12 weeks of treatment using criteria for progression that included serum prostate-specific antigen measurement, bone and computerized tomography imaging and symptom assessments. Acquired resistance was determined using the end point of time to treatment change (TTTC), defined as time from enrollment until change in treatment from progressive disease. Associations of genomic and transcriptomic alterations with primary resistance were determined using logistic regression, Fisher's exact test, single and multivariate analyses. Cox regression models were utilized for determining association of genomic and transcriptomic alterations with TTTC. Results: At 12 weeks, 32 patients in the cohort had progressed (nonresponders). Median study follow-up was 32.1 months by which time 58 patients had switched treatments due to progression. Median TTTC was 10.1 months (interquartile range: 4.4-24.1). Genes in the Wnt/ß-catenin pathway were more frequently mutated and negative regulators of Wnt/ß-catenin signaling were more frequently deleted or displayed reduced mRNA expression in nonresponders. Additionally, mRNA expression of cell cycle regulatory genes was increased in nonresponders. In multivariate models, increased cell cycle proliferation scores (≥ 50) were associated with shorter TTTC (hazard ratio = 2.11, 95% confidence interval: 1.17-3.80; P = 0.01). Conclusions: Wnt/ß-catenin pathway activation and increased cell cycle progression scores can serve as molecular markers for predicting resistance to AA/P therapy.


Assuntos
Acetato de Abiraterona/administração & dosagem , Resistencia a Medicamentos Antineoplásicos/genética , Prednisona/administração & dosagem , Neoplasias de Próstata Resistentes à Castração/genética , Via de Sinalização Wnt/genética , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclo Celular , Proliferação de Células , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/genética , Estudos Prospectivos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico
7.
Appl Opt ; 56(18): 5274-5294, 2017 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29047582

RESUMO

The Cassini spacecraft orbiting Saturn carries the composite infrared spectrometer (CIRS) designed to study thermal emission from Saturn and its rings and moons. CIRS, a Fourier transform spectrometer, is an indispensable part of the payload providing unique measurements and important synergies with the other instruments. It takes full advantage of Cassini's 13-year-long mission and surpasses the capabilities of previous spectrometers on Voyager 1 and 2. The instrument, consisting of two interferometers sharing a telescope and a scan mechanism, covers over a factor of 100 in wavelength in the mid and far infrared. It is used to study temperature, composition, structure, and dynamics of the atmospheres of Jupiter, Saturn, and Titan, the rings of Saturn, and surfaces of the icy moons. CIRS has returned a large volume of scientific results, the culmination of over 30 years of instrument development, operation, data calibration, and analysis. As Cassini and CIRS reach the end of their mission in 2017, we expect that archived spectra will be used by scientists for many years to come.

9.
Rep Prog Phys ; 78(1): 016501, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25551840

RESUMO

Diamondoids are small hydrocarbon molecules which have the same rigid cage structure as bulk diamond. They can be considered the smallest nanoparticles of diamond. They exhibit a mixture of properties inherited from bulk cubic diamond as well as a number of unique properties related to their size and structure. Diamondoids with different sizes and shapes can be separated and purified, enabling detailed studies of the effects of size and structure on the diamondoids' properties and also allowing the creation of chemically functionalized diamondoids which can be used to create new materials. Most notable among these new materials are self-assembled monolayers of diamondoid-thiols, which exhibit a number of unique electron emission properties.

10.
Tech Coloproctol ; 18(3): 257-64, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23907675

RESUMO

BACKGROUND: The aim of this study was to determine whether mobilization of the splenic flexure during anterior resection is associated with an increased number of complications. METHODS: This is a retrospective cohort analysis of all non-emergent anterior resections with anastomosis (open and laparoscopic) between January 2005 and December 2009 from the American College of Surgeons National Surgical Quality Improvement Program. Infectious, renal, and pulmonary adverse events as well as operative times were analyzed for cases with splenic flexure mobilization as compared to no mobilization. We then constructed multivariate models to identify risk factors for postsurgical adverse events. RESULTS: During the 5-year study period, 6,324 (57 %) open resections and 4,788 (43 %) laparoscopic resections were performed. Mobilization of the splenic flexure was associated with an increase in operating room time (204 vs 172 min, p < 0.0001). Although anastomotic leaks were not recorded, there was no difference in organ space infections (3.9 vs 3.7 %, p = 0.7) or return to operating room events between the two groups. However, patients who underwent splenic flexure mobilization had significantly more superficial surgical site infections (10.6 vs 8.4 %, p < 0.0002). Multivariate analysis accounting for laparoscopic or open surgery and standard preoperative and intraoperative variables demonstrated a persistent increase in superficial surgical site infections for patients with splenic flexure mobilization. CONCLUSIONS: Operating room times are longer and superficial surgical site infections are more common when the splenic flexure is mobilized. The absolute indications for splenic flexure mobilization should be addressed in further research.


Assuntos
Colo Transverso/cirurgia , Doenças do Colo/cirurgia , Complicações Pós-Operatórias/epidemiologia , Anastomose Cirúrgica , Comorbidade , Feminino , Humanos , Laparoscopia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
11.
Front Physiol ; 15: 1334874, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38784113

RESUMO

Background: High-altitude populations exhibit distinct cellular, respiratory, and cardiovascular phenotypes, some of which provide adaptive advantages to hypoxic conditions compared to populations with sea-level ancestry. Studies performed in populations with a history of high-altitude residence, such as Tibetans, support the idea that many of these phenotypes may be shaped by genomic features that have been positively selected for throughout generations. We hypothesize that such traits observed in Tibetans at high altitude also occur in Tibetans living at intermediate altitude, even in the absence of severe sustained hypoxia. Methodology: We studied individuals of high-altitude ancestry (Tibetans, n = 17 females; n = 12 males) and sea-level ancestry (Han Chinese, n = 6 females; n = 10 males), both who had been living at ∼1300 m (∼4327 ft) for at least 18 months. We measured hemoglobin concentration ([Hb]), hypoxic ventilatory response (HVR), and hypoxic heart rate response (HHRR) with end-tidal CO2 (PetCO2) held constant (isocapnia) or allowed to decrease with hypoxic hyperventilation (poikilocapnia). We also quantified the contribution of CO2 on ventilation and heart rate by calculating the differences of isocapnic versus poikilocapnic hypoxic conditions (Δ V˙I/ΔPetCO2 and ΔHR/ΔPetCO2, respectively). Results: Male Tibetans had lower [Hb] compared to Han Chinese males (p < 0.05), consistent with reports for individuals from these populations living at high altitude and sea level. Measurements of ventilation (resting ventilation, HVR, and PetCO2) were similar for both groups. Heart rate responses to hypoxia were similar in both groups during isocapnia; however, HHRR in poikilocapnia was reduced in the Tibetan group (p < 0.03), and the heart rate response to CO2 in hypoxia was lower in Tibetans relative to Han Chinese (p < 0.01). Conclusion: These results suggest that Tibetans living at intermediate altitude have blunted cardiac responses in the context of hypoxia. Hence, only some of the phenotypes observed in Tibetans living at high altitude are observed in Tibetans living at intermediate altitude. Whereas blunted cardiac responses to hypoxia is revealed at intermediate altitudes, manifestation of other physiological adaptations to high altitude may require exposure to more severe levels of hypoxia.

12.
Nature ; 450(7170): 641-5, 2007 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-18046396

RESUMO

The upper atmosphere of a planet is a transition region in which energy is transferred between the deeper atmosphere and outer space. Molecular emissions from the upper atmosphere (90-120 km altitude) of Venus can be used to investigate the energetics and to trace the circulation of this hitherto little-studied region. Previous spacecraft and ground-based observations of infrared emission from CO2, O2 and NO have established that photochemical and dynamic activity controls the structure of the upper atmosphere of Venus. These data, however, have left unresolved the precise altitude of the emission owing to a lack of data and of an adequate observing geometry. Here we report measurements of day-side CO2 non-local thermodynamic equilibrium emission at 4.3 microm, extending from 90 to 120 km altitude, and of night-side O2 emission extending from 95 to 100 km. The CO2 emission peak occurs at approximately 115 km and varies with solar zenith angle over a range of approximately 10 km. This confirms previous modelling, and permits the beginning of a systematic study of the variability of the emission. The O2 peak emission happens at 96 km +/- 1 km, which is consistent with three-body recombination of oxygen atoms transported from the day side by a global thermospheric sub-solar to anti-solar circulation, as previously predicted.

13.
Nature ; 450(7170): 637-40, 2007 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-18046395

RESUMO

Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright 'dipole' feature surrounded by a cold 'collar' at its north pole. The polar dipole is a 'double-eye' feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus' south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50 km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition.

14.
Appl Microbiol Biotechnol ; 97(15): 7049-59, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23771779

RESUMO

Phaeodactylum tricornutum is a marine diatom in the class Bacillariophyceae and is important ecologically and industrially with regards to ocean primary production and lipid accumulation for biofuel production, respectively. Triacylglyceride (TAG) accumulation has been reported in P. tricornutum under different nutrient stresses, and our results show that lipid accumulation can occur with nitrate or phosphate depletion. However, greater lipid accumulation was observed when both nutrients were depleted as observed using a Nile Red assay and fatty acid methyl ester (FAME) profiles. Nitrate depletion had a greater effect on lipid accumulation than phosphate depletion. Lipid accumulation in P. tricornutum was arrested upon resupplementation with the depleted nutrient. Cells depleted of nitrogen showed a distinct shift from a lipid accumulation mode to cellular growth post-resupplementation with nitrate, as observed through increased cell numbers and consumption of accumulated lipid. Phosphate depletion caused lipid accumulation that was arrested upon phosphate resupplementation. The cessation of lipid accumulation was followed by lipid consumption without an increase in cell numbers. Cells depleted in both nitrate and phosphate displayed cell growth upon the addition of both nitrate and phosphate and had the largest observed lipid consumption upon resupplementation. These results indicate that phosphate resupplementation can shut down lipid accumulation but does not cause cells to shift into cellular growth, unlike nitrate resupplementation. These data suggest that nutrient resupplementation will arrest lipid accumulation and that switching between cellular growth and lipid accumulation can be regulated upon the availability of nitrogen and phosphorus.


Assuntos
Biocombustíveis , Diatomáceas/metabolismo , Meios de Cultura , Ésteres , Ácidos Graxos/metabolismo , Triglicerídeos/metabolismo
15.
J Neurotrauma ; 40(1-2): 112-124, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35979888

RESUMO

Traumatic brain injuries (TBIs) affect more than 10 million patients annually worldwide, causing long-term cognitive and psychosocial impairments. Frontal lobe TBIs commonly impair executive function, but laboratory models typically focus primarily on spatial learning and declarative memory. We implemented a multi-modal approach for clinically relevant cognitive-behavioral assessments of frontal lobe function in rats with TBI and assessed treatment benefits of the serotonin-norepinephrine reuptake inhibitor, milnacipran (MLN). Two attentional set-shifting tasks (AST) evaluated cognitive flexibility via the rats' ability to locate food-based rewards by learning, unlearning, and relearning sequential rule sets with shifting salient cues. Adult male rats reached stable pre-injury operant AST (oAST) performance in 3-4 weeks, then were isoflurane-anesthetized, subjected to a unilateral frontal lobe controlled cortical impact (2.4 mm depth, 4 m/sec velocity) or Sham injury, and randomized to treatment conditions. Milnacipran (30 mg/kg/day) or vehicle (VEH; 10% ethanol in saline) was administered intraperitoneally via implanted osmotic minipumps (continuous infusions post-surgery, 60 µL/h). Rats had a 10-day recovery post-TBI/Sham before performing light/location-based oAST for 10 days and, subsequently, odor/media-based digging AST (dAST) on the last test day (26-27 days post-injury) before sacrifice. Both AST tests revealed significant deficits in TBI+VEH rats, seen as elevated total trials and errors (p < 0.05), which generally normalized in MLN-treated rats (p < 0.05). This first simultaneous dual AST assessment demonstrates oAST and dAST are sufficiently sensitive and robust to detect subtle attentional and cognitive flexibility executive impairments after frontal lobe TBI in rats. Chronic MLN administration shows promise for attenuation of post-TBI executive function deficits, thus meriting further investigation.


Assuntos
Lesões Encefálicas Traumáticas , Função Executiva , Animais , Masculino , Ratos , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/tratamento farmacológico , Modelos Animais de Doenças , Lobo Frontal , Aprendizagem em Labirinto , Milnaciprano , Ratos Sprague-Dawley
16.
Brain Res ; 1808: 148336, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36948353

RESUMO

Impaired attention is central to the cognitive deficits associated with long-term sequelae for many traumatic brain injury (TBI) survivors. Assessing complex sustained attention post-TBI is clinically-relevant and may provide reliable avenues towards developing therapeutic and rehabilitation targets in both males and females. We hypothesized that rats subjected to a moderate TBI will exhibit attentional deficits seen as reduced accuracy and increased distractibility in an operant 3-choice serial reaction time task (3-CSRT), designed as an analogue of the clinical continuous performance test. Upon reaching baseline of 70% accuracy at the 300 ms cue, adult male and female Sprague-Dawley rats were subjected to a controlled cortical impact (2.8 mm deformation at 4 m/s) or sham injury over the right parietal cortex. After two weeks of recovery, they were retested on the 3-CSRT for ten days. Dependent measures include percent accuracy (overall and for each of the three cue ports), percent omissions, as well as latency to instrumental poke and retrieve reward. Results demonstrate that both males and females displayed reduced percent accuracy and increased omissions when re-tested post-TBI on 3-CSRT compared to Sham rats and to their own pre-insult baseline (p's < 0.05). Performance accuracy was impaired consistently throughout the ten days of post-surgery re-testing, suggesting pronounced and long-lasting dysfunction in sustained attention processes. Deficits were specifically more pronounced when the cue was pseudorandomly presented in the left-side cue port (p < 0.05), mirroring clinical hemispatial neglect. These data demonstrate significant and persistent complex attention impairments in both sexes after TBI, rendering identifying efficient therapies for cognitive recovery as pivotal.


Assuntos
Lesões Encefálicas Traumáticas , Transtornos Cognitivos , Ratos , Masculino , Feminino , Animais , Tempo de Reação , Ratos Sprague-Dawley , Lesões Encefálicas Traumáticas/tratamento farmacológico , Atenção
18.
Vet Immunol Immunopathol ; 243: 110366, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34896773

RESUMO

Th17 cells are T helper cells which play an important role during inflammation and autoimmune disease. To investigate the role of these cells in diseases in dogs in a clinical setting, methods for fast identification had to be established. Th17 cells are a rare cell population, for their measurement stimulation is recommended. To examine more samples simultaneously and to receive a relatively high purity of cell population of CD3 + CD4+ cells, different methods on various levels of preselection of cells as well as the possibility of storing blood overnight for measuring Th17 cells by flow cytometry were investigated. Firstly, to receive a high number of mononuclear cells, two different density gradients were compared and analysed. Furthermore, the enrichment of CD3 + CD4+ cells via depletion of CD8alpha+, CD11b + and CD21+ cells by cell sorting (autoMACS Pro Separator) was tested. It was also investigated whether stimulation processes led to better interpretation of results and whether there was a significant difference in measurement of directly processed blood samples and samples that had been stored overnight. In conclusion, the use of the density gradient (Lymph24+ Spin Medium) resulted in a purer cell population through a significant decrease in polymorphonuclear cells (*p = 0.01). After cell sorting, a significant difference in cell population purity was detected. Within the target fraction (containing mainly CD3 + CD4+ cells), CD8alpha+, CD21+, CD11b + cell percentages were significantly lower (***p < 0.001, *p < 0.02, ***p < .0001, respectively), and CD3 + CD4+ cell percentage was significantly higher (***p < .0001). There was a significant difference in Th17 cell percentage between unstimulated and stimulated cell populations (***p < .0001), but no significant difference in the percentage of unstimulated Th17 cells (p = 0.29) or stimulated Th17 cells (p = 0.71) in stored blood in comparison to directly processed EDTA blood samples. Finally, a modified protocol that offers an efficient way to investigate samples that were stored overnight by means of flow cytometry was evolved to research the role of Th17 cells in dogs with different diseases or in healthy populations.


Assuntos
Citometria de Fluxo , Células Th17 , Animais , Separação Celular/veterinária , Cães , Citometria de Fluxo/veterinária , Leucócitos , Neutrófilos
19.
Nature ; 427(6970): 132-5, 2004 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-14712270

RESUMO

The Earth's equatorial stratosphere shows oscillations in which the east-west winds reverse direction and the temperatures change cyclically with a period of about two years. This phenomenon, called the quasi-biennial oscillation, also affects the dynamics of the mid- and high-latitude stratosphere and weather in the lower atmosphere. Ground-based observations have suggested that similar temperature oscillations (with a 4-5-yr cycle) occur on Jupiter, but these data suffer from poor vertical resolution and Jupiter's stratospheric wind velocities have not yet been determined. Here we report maps of temperatures and winds with high spatial resolution, obtained from spacecraft measurements of infrared spectra of Jupiter's stratosphere. We find an intense, high-altitude equatorial jet with a speed of approximately 140 m s(-1), whose spatial structure resembles that of a quasi-quadrennial oscillation. Wave activity in the stratosphere also appears analogous to that occurring on Earth. A strong interaction between Jupiter and its plasma environment produces hot spots in its upper atmosphere and stratosphere near its poles, and the temperature maps define the penetration of the hot spots into the stratosphere.

20.
Can J Microbiol ; 56(4): 342-7, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20453901

RESUMO

Bacteria from the genus Herbaspirillum are endophytes responsible for nitrogen fixation in gramineous plants of economic importance such as maize, sugarcane, sorghum, rice, and wheat. Some species are known to produce plant growth substances. In contrast, Herbaspirillum rubrisubalbicans strains are known to be mild plant pathogens. The molecular communication between the plant and the microbes might involve lipopolysaccharides present in the outer membrane of these gram-negative bacteria. Phenol-water extraction was used to obtain lipopolysaccharides from 7 strains of Herbaspirillum seropedicae (SmR1, Z67, Z78, ZA95, and M2) and H. rubrisubalbicans (M1 and M4). The electrophoretic profiles and chemical composition of the lipopolysaccharides obtained in the phenol and aqueous extracts were shown herein.


Assuntos
Herbaspirillum/química , Lipopolissacarídeos/química , Poaceae/microbiologia , Herbaspirillum/fisiologia , Fixação de Nitrogênio
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