409 research outputs found
Lanreotide depot deep subcutaneous injection: a new method of delivery and its associated benefits
Acromegaly is a rare disease characterized by excessive growth hormone secretion, usually from a pituitary tumor. Treatment options include surgery, medical therapy, and in some cases, radiation therapy. Current medical therapy consists of treatment with somatostatin analog medications or a growth hormone receptor antagonist. There are two somatostatin analogs currently in use, octreotide and lanreotide. Both are supplied in long-acting formulations and are of comparable biochemical efficacy. Lanreotide is supplied in a prefilled syringe and is injected into deep subcutaneous tissue. Studies have been conducted to assess the efficacy of self- or partner administration, and have demonstrated that injection of lanreotide can be accomplished reliably and safely outside a physician’s office. For patients who have achieved biochemical control with lanreotide, the FDA has recently approved an extended dosing interval. Selected patients may be able to receive the medication less frequently with injections of 120 mg administered every 6 or 8 weeks. This review focuses on the use of lanreotide in the treatment of acromegaly, the safety and efficacy of the drug, and the benefits afforded to patients because of unique aspects of the delivery of lanreotide
Resonance fluorescence in a band gap material: Direct numerical simulation of non-Markovian evolution
A numerical method of calculating the non-Markovian evolution of a driven
atom radiating into a structured continuum is developed. The formal solution
for the atomic reduced density matrix is written as a Markovian algorithm by
introducing a set of additional, virtual density matrices which follow, to the
level of approximation of the algorithm, all the possible trajectories of the
photons in the electromagnetic field. The technique is perturbative in the
sense that more virtual density matrices are required as the product of the
effective memory time and the effective coupling strength become larger. The
number of density matrices required is given by where is the number
of timesteps per memory time. The technique is applied to the problem of a
driven two-level atom radiating close to a photonic band gap and the
steady-state correlation function of the atom is calculated.Comment: 14 pages, 9 figure
Measurement master equation
We derive a master equation describing the evolution of a quantum system
subjected to a sequence of observations. These measurements occur randomly at a
given rate and can be of a very general form. As an example, we analyse the
effects of these measurements on the evolution of a two-level atom driven by an
electromagnetic field. For the associated quantum trajectories we find Rabi
oscillations, Zeno-effect type behaviour and random telegraph evolution spawned
by mini quantum jumps as we change the rates and strengths of measurement.Comment: 14 pages and 8 figures, Optics Communications in pres
Removal of a single photon by adaptive absorption
We present a method to remove, using only linear optics, exactly one photon
from a field-mode. This is achieved by putting the system in contact with an
absorbing environment which is under continuous monitoring. A feedback
mechanism then decouples the system from the environment as soon as the first
photon is absorbed. We propose a possible scheme to implement this process and
provide the theoretical tools to describe it
Quercetin Ingestion Does Not Alter Cytokine Changes in Athletes Competing in the Western States Endurance Run
The purpose of this study was to measure the influence of quercetin on plasma cytokines, leukocyte cytokine mRNA, and related variables in ultramarathoners competing in the 160-km Western States Endurance Run (WSER). Sixty-three runners were randomized to quercetin and placebo groups and under double-blinded methods ingested 1000 mg/day quercetin for 3 weeks before the WSER. Thirty-nine of the 63 subjects (n = 18 for quercetin, n = 21 for placebo) finished the race and provided blood samples the morning before the race and 15–30 min postrace. Significant prerace to postrace WSER increases were measured for nine proinflammatory and anti-inflammatory plasma cytokines, cortisol (quercetin = 94%, placebo = 96%), serum C-reactive protein (CRP) (mean ± SE absolute increase, quercetin = 31.8 ± 4.2, placebo = 38.2 ± 5.0 mg/L), and creatine kinase (CK) (quercetin = 21,575 ± 3,977, placebo = 19,455 ± 3,969 U/L), with no significant group differences. Interleukin-6 (IL-6) mRNA did not change post-WSER, with a significant decrease measured for leukocyte IL-8 mRNA (0.21 ± 0.03-fold and 0.25 ± 0.04-fold change from rest, quercetin and placebo, respectively) and significant increases for IL-1Ra mRNA (1.43 ± 0.18-fold and 1.40 ± 0.16-fold change, quercetin and placebo, respectively) and IL-10 mRNA (12.9 ± 3.9-fold and 17.2 ± 6.1-fold change, quercetin and placebo, respectively), with no significant differences between groups. In conclusion, quercetin ingestion (1 g/day) by ultramarathon athletes for 3 weeks before a competitive 160-km race significantly increased plasma quercetin levels but failed to attenuate muscle damage, inflammation, increases in plasma cytokine and hormone levels, and alterations in leukocyte cytokine mRNA expression
Dihydropyridine receptors and type 1 ryanodine receptors constitute the molecular machinery for voltage-induced Ca2+ release in nerve terminals
Ca2+ stores were studied in a preparation of freshly dissociated terminals from hypothalamic magnocellular neurons. Depolarization from a holding level of -80 mV in the absence of extracellular Ca2+ elicited Ca2+ release from intraterminal stores, a ryanodine-sensitive process designated as voltage-induced Ca2+ release (VICaR). The release took one of two forms: an increase in the frequency but not the quantal size of Ca2+ syntillas, which are brief, focal Ca2+ transients, or an increase in global [Ca2+]. The present study provides evidence that the sensors of membrane potential for VICaR are dihydropyridine receptors (DHPRs). First, over the range of -80 to -60 mV, in which there was no detectable voltage-gated inward Ca2+ current, syntilla frequency was increased e-fold per 8.4 mV of depolarization, a value consistent with the voltage sensitivity of DHPR-mediated VICaR in skeletal muscle. Second, VICaR was blocked by the dihydropyridine antagonist nifedipine, which immobilizes the gating charge of DHPRs but not by Cd2+ or FPL 64176 (methyl 2,5 dimethyl-4[2-(phenylmethyl)benzoyl]-1H-pyrrole-3-carboxylate), a non-dihydropyridine agonist specific for L-type Ca2+ channels, having no effect on gating charge movement. At 0 mV, the IC50 for nifedipine blockade of VICaR in the form of syntillas was 214 nM in the absence of extracellular Ca2+. Third, type 1 ryanodine receptors, the type to which DHPRs are coupled in skeletal muscle, were detected immunohistochemically at the plasma membrane of the terminals. VICaR may constitute a new link between neuronal activity, as signaled by depolarization, and a rise in intraterminal Ca2+
Successive Bouts of Cycling Stimulates Genes Associated with Mitochondrial Biogenesis
Exercise increases mRNA for genes involved in mitochondrial biogenesis and oxidative enzyme capacity. However, little is known about how these genes respond to consecutive bouts of prolonged exercise. We examined the effects of 3 h of intensive cycling performed on three consecutive days on the mRNA associated with mitochondrial biogenesis in trained human subjects. Forty trained cyclists were tested for VO2max (54.7 ± 1.1 ml kg−1 min−1). The subjects cycled at 57% wattsmax for 3 h using their own bicycles on CompuTrainer™ Pro Model trainers (RacerMate, Seattle, WA) on three consecutive days. Muscle biopsies were obtained from the vastus lateralis pre- and post-exercise on days one and three. Muscle samples were analyzed for mRNA content of peroxisome proliferator receptor gamma coactivator-1 alpha (PGC-1α), sirtuin 1 (Sirt-1), cytochrome c, and citrate synthase. Data were analyzed using a 2 (time) × 2 (day) repeated measures ANOVA. Of the mRNA analyzed, the following increased from pre to post 3 h rides: cytochrome c (P = 0.006), citrate synthase (P = 0.03), PGC-1α (P \u3c 0.001), and Sirt-1 (P = 0.005). The following mRNA showed significant effects from days one to three: cytochrome c (P \u3c 0.001) and citrate synthase (P = 0.01). These data show that exhaustive cycling performed on three consecutive days resulted in both acute and chronic stimuli for mRNA associated with mitochondrial biogenesis in already trained subjects. This is the first study to illustrate an increase in sirtuin-1 mRNA with acute and chronic exercise. These data contribute to the understanding of mRNA expression during both acute and successive bouts of prolonged exercise
Comparative inverse analysis of satellite (MOPITT) and aircraft (TRACE-P) observations to estimate Asian sources of carbon monoxide
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