Pollen tubes are tip-growing cells that create safe routes to convey sperm cells to the embryo sac for double fertilization. Recent studies have purified and biochemically characterized ...detergent-insoluble membranes from tobacco pollen tubes. These microdomains, called lipid rafts, are rich in sterols and sphingolipids and are involved in cell polarization in organisms evolutionarily distant, such as fungi and mammals. The presence of actin in tobacco pollen tube detergent-insoluble membranes and the preferential distribution of these domains on the apical plasma membrane encouraged us to formulate the intriguing hypothesis that sterols and sphingolipids could be a “trait d’union” between actin dynamics and polarized secretion at the tip. To unravel the role of sterols and sphingolipids in tobacco pollen tube growth, we used squalestatin and myriocin, inhibitors of sterol and sphingolipid biosynthesis, respectively, to determine whether lipid modifications affect actin fringe morphology and dynamics, leading to changes in clear zone organization and cell wall deposition, thus suggesting a role played by these lipids in successful fertilization.
Live optical microscopy has become an essential tool for studying the dynamical behaviors and variability of single cells, and cell-cell interactions. However, experiments and data analysis in this ...area are often extremely labor intensive, and it has often not been achievable or practical to perform properly standardized experiments on a statistically viable scale. We have addressed this challenge by developing automated live imaging platforms, to help standardize experiments, increasing throughput, and unlocking previously impossible ones. Our real-time cell tracking programs communicate in feedback with microscope and camera control software, and they are highly customizable, flexible, and efficient. As examples of our current research which utilize these automated platforms, we describe two quite different applications: egress-invasion interactions of malaria parasites and red blood cells, and imaging of immune cells which possess high motility and internal dynamics. The automated imaging platforms are able to track a large number of motile cells simultaneously, over hours or even days at a time, greatly increasing data throughput and opening up new experimental possibilities.
Herpes simplex viruses (HSV) can produce encephalitis (HSE), which requires early detection, typically using polymerase chain reaction (PCR) in cerebrospinal fluid (CSF). However, other neurological ...conditions not directly caused by HSV may also present with a positive HSV PCR in the CSF (NCNHPCR+). We aimed to analyze the clinical features of both groups of patients (HSE vs. NCNHPCR+) and to consider the potential relevance of this finding in the latter.
A retrospective analysis of clinical presentation, workup (CSF, EEG, and MRI) and outcome of patients with an HSV+ result in CSF was conducted from Jan-2007 to Sep-2015 in our institution. Patients under 18 years and those with nonencephalitic HSV associated disorders were excluded. Group comparison between HSE and NCNHPCR+ patients was conducted using parametric and nonparametric tests accordingly.
Sixteen HSE and 23 NCNHPCR+ patients were included. Patients with HSE presented a higher incidence of headache (87.5% vs. 43.5%; P=0.008), meningeal symptoms (50% vs. 17.4%; P=0.04), pleocytosis (75% vs. 18%; P=0.001), EEG abnormalities (46.67% vs. 22%; P=0.02) and typical MRI findings (50% vs. 0%; P<0.001), whereas 35% of patients with NCNHPCR+ had an underlying immunologic disorder (35% vs. 0%; P=0.012).
The pathogenic role of HSV in NCNHPCR+ is uncertain. This finding must be interpreted in the appropriate clinical, EEG, and neuroimaging context. Immunocompromise and neuroinflammation states could be related to a higher presence of HSV in CSF.
In this work, the laccase catalyzed degradation of reactive textile dyes was studied in supercritical carbon dioxide media. A two level Box–Behnken factorial design with two factors and response ...surface methodology (RSM) were performed to investigate and optimize the effects of pressure and temperature on reactive red 239 (RR239), reactive yellow 15 (RY15) and reactive black 5 (RB5) dye degradations by commercial laccase in supercritical carbon dioxide media. Mathematical models were developed for each dye showing the effect of each factor and their interactions on color removal. Pressure and the interaction between temperature and pressure were the main factors affecting the decolorization. The optimum conditions for RB5 and RY15 were found to be high pressure values (>120 bar), whilst the temperature presented a minor effect on their degradation at these pressures. For RR239, both variables influenced the decolorization and the optimum conditions appear to be at low values of pressure and high values of temperature.
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