Search Results

You are looking at 1 - 10 of 10 items

  • Author: J.T. Reddy x
Clear All Modify Search

Abstract

Introduction of a bean phenylalanine ammonia-lyase (PAL) transgene into tobacco plants results in epigenetic post-transcriptional gene silencing which is unstable, such that after self-pollination first generation progeny may become PAL over-expressors. The change from gene silencing to PAL over-expression is accompanied by a loss of cytosine methylation of the PAL transgene and reduced methylation of the endogenous tobacco PAL2 gene, but not the PAL1 gene. These changes are associated with the appearance of high levels of bean PAL and tobacco PAL2 transcripts in the total RNA fraction from PAL over-expressing plants. However, tobacco PAL2 transcripts are inefficiently recruited into polysomes, and tobacco PAL2 protein is not detected in leaves of PAL over-expressing or wild-type lines. Thus, in spite of the post-transcriptionally controlled increase in tobacco PAL2 transcripts in PAL over-expressors, the increased PAL activity is primarily the result of the increase in bean PAL transcripts and corresponding enzymatic activity. These results reveal a complex cross-talk between expression of the PAL transgene and the corresponding endogenous PAL genes at the levels of transcription, transcript stability and polysomal recruitment during sense transgene-mediated silencing and subsequent over-expresson of PAL in tobacco.

Abstract

The laminar boundary layer MHD three-dimensional mixed convective flow of Maxwell nanofluid towards a bidirectional stretching sheet with non-linear radiation is analyzed. A constant magnetic field is implemented normal to the fluid flow direction. A numerical technique of Runge-Kutta-Fehlberg (RFK45) is utilized to obtain the numerical solution of the dimensionless coupled ODEs with associated boundary conditions. The various pertinent dimensionless parameters on the flow are examined with the help of graphs and tables. Results shows that, nonlinear thermal radiation is more influential o on temperature profile when compared to linear thermal radiation.

Abstract

Background: Spinal cord stimulation has been in use for decades and is growing as a therapeutic treatment option. A significant problem arising from the epidural location of the lead is electrical shunting through the cerebrospinal fluid, providing sub-optimal delivery of the electrical current specifically to the Aβ fibers of the dorsal column.

Objective: Our goal is to design a safe and effective intradural spinal cord stimulator (SCS) that places the stimulating electrodes directly against the pia similar to what is currently employed with the auditory brainstem implant.

Methods: We have reviewed the literature on the early original intradural SCSs and designed, built, and tested an improved device that seeks to overcome the limitations the existing epidural stimulators.

Results: In particular, we have shown that the present design of our device allows for motion of the spinal cord without the device being displaced itself, exerts a surface pressure on the spinal cord surface that is below what would cause ischemia or vessel injury, activates somato-sensory evoked potentials at a lower threshold than epidural stimulation, and (iv) does not cause deleterious neurological deficits in a chronic ovine model of intradural stimulator implantation.

Conclusion: While further studies to prove long-term safety and durability of the device are underway, we believe that revisiting an intradural approach to spinal cord stimulation may continue to improve our ability to treat certain chronic pain states and possibly the spasticity associated with spinal cord injuries.

Abstract

Objective

To determine the frequency of sepsis and other adverse neonatal outcomes in women with a clinical diagnosis of chorioamnionitis.

Methods

We performed a secondary analysis of a multi-center placebo-controlled trial of vitamins C/E to prevent preeclampsia in low risk nulliparous women. Clinical chorioamnionitis was defined as either the “clinical diagnosis” of chorioamnionitis or antibiotic administration during labor because of an elevated temperature or uterine tenderness in the absence of another cause. Early-onset neonatal sepsis was categorized as “suspected” or “confirmed” based on a clinical diagnosis with negative or positive blood, urine or cerebral spinal fluid cultures, respectively, within 72 h of birth. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression.

Results

Data from 9391 mother-infant pairs were analyzed. The frequency of chorioamnionitis was 10.3%. Overall, 6.6% of the neonates were diagnosed with confirmed (0.2%) or suspected (6.4%) early-onset sepsis. Only 0.7% of infants born in the setting of chorioamnionitis had culture-proven early-onset sepsis versus 0.1% if chorioamnionitis was not present. Clinical chorioamnionitis was associated with both suspected [OR 4.01 (3.16–5.08)] and confirmed [OR 4.93 (1.65–14.74)] early-onset neonatal sepsis, a need for resuscitation within the first 30 min after birth [OR 2.10 (1.70–2.61)], respiratory distress [OR 3.14 (2.16–4.56)], 1 min Apgar score of ≤3 [OR 2.69 (2.01–3.60)] and 4–7 [OR 1.71 (1.43–2.04)] and 5 min Apgar score of 4–7 [OR 1.67 (1.17–2.37)] (vs. 8–10).

Conclusion

Clinical chorioamnionitis is common and is associated with neonatal morbidities. However, the vast majority of exposed infants (99.3%) do not have confirmed early-onset sepsis.