437 research outputs found
Olanzapine and fluoxetine combination therapy for treatment-resistant depression: review of efficacy, safety, and study design issues
Treatment-resistant depression (TRD) is a common occurrence in clinical practice. Up to 30% of patients with major depression do not respond to conventional antidepressant treatment, while a significantly greater number of patients experience only partial symptom reduction. Numerous strategies may be applied by the practicing clinician to overcome limitations in the effectiveness of antidepressant monotherapy, including combining drug treatment with evidence-supported psychotherapies, combining antidepressants (combination pharmacotherapy), and combining antidepressants with other non-antidepressant psychotropic medications (augmentation treatment). One such augmentation strategy, the combination of the selective serotonin reuptake inhibitor, fluoxetine (FLX), with the atypical antipsychotic drug, olanzapine (OLZ), is supported by the results of four randomized, double-blind, acute phase studies of patients who had responded inadequately to antidepressant monotherapy. In each study, the FLX/OLZ combination caused rapid reduction in Montgomery-Asberg Depression Rating scale scores, with two of the four studies showing significantly greater improvement than antidepressant monotherapy at study endpoint. Effects of the FLX/OLZ combination were strongest in cases where failure to respond to two antidepressants prior to randomization was established during the current depressive episode. The FLX/OLZ combination was well-tolerated; however, body weight gain and increases in prolactin were greater than that of the antidepressant monotherapy groups, and were comparable to that of OLZ monotherapy. While effective during acute-phase treatment, questions remain regarding the long-term efficacy and safety of FLX/OLZ relative to antidepressant monotherapy and other combination strategies. Efforts aimed at determining the placement of FLX/OLZ among the available options for addressing TRD are limited by lack of comparison and sequential treatment studies. Important aspects of study design and directions for future research are discussed
Combinatorial Pharmacogenomic Algorithm is Predictive of Citalopram and Escitalopram Metabolism in Patients with Major Depressive Disorder
Pharmacogenomic tests used to guide clinical treatment for major depressive disorder (MDD) must be thoroughly validated. One important assessment of validity is the ability to predict medication blood levels, which reflect altered metabolism. Historically, the metabolic impact of individual genes has been evaluated; however, we now know that multiple genes are often involved in medication metabolism. Here, we evaluated the ability of individual pharmacokinetic genes (CYP2C19, CYP2D6, CYP3A4) and a combinatorial pharmacogenomic test (GeneSight Psychotropic(R); weighted assessment of all three genes) to predict citalopram/escitalopram blood levels in patients with MDD. Patients from the Genomics Used to Improve DEpression Decisions (GUIDED) trial who were taking citalopram/escitalopram at screening and had available blood level data were included (N=191). In multivariate analysis of the individual genes and combinatorial pharmacogenomic test separately (adjusted for age, smoking status), the F statistic for the combinatorial pharmacogenomic test was 1.7 to 2.9-times higher than the individual genes, showing that it explained more variance in citalopram/escitalopram blood levels. In multivariate analysis of the individual genes and combinatorial pharmacogenomic test together, only the combinatorial pharmacogenomic test remained significant. Overall, this demonstrates that the combinatorial pharmacogenomic test was a superior predictor of citalopram/escitalopram blood levels compared to individual genes
Alginate hydrogel has a negative impact on in vitro collagen 1 deposition by fibroblasts
Hydrogels have been widely investigated as 3D culture substrates because of their reported structural similarity to the extracellular matrix (ECM). Limited ECM deposition, however, occurs within these materials, so the resulting “tissues” bear little resemblance to those found in the body. Here matrix deposition by fibroblasts encapsulated within a calcium alginate (Ca-alg) hydrogel was investigated. Although the cells transcribed mRNA for coll Iα over a period of 3 weeks, very little collagen protein deposition was observed within the gel by histology or immunohistochemistry (IHC). Although molecular diffusion demonstrated charge dependency, this did not prevent the flux of both positively and negative charged amino acids through the gel, suggesting that the absence of ECM could not be attributed to substrate limitation. The flux of protein, however, was charge-dependent as proteins with a net negative charge passed quickly through the Ca-alg into the medium. The minimal collagen deposition within the Ca-alg was attributed to a combination of rapid movement of negatively charged procollagen through the gel and steric hindrance of fibril formation
Combinatorial pharmacogenomic algorithm is predictive of citalopram and escitalopram metabolism in patients with major depressive disorder
Pharmacogenomic tests used to guide clinical treatment for major depressive disorder (MDD) must be thoroughly validated. One important assessment of validity is the ability to predict medication blood levels, which reflect altered metabolism. Historically, the metabolic impact of individual genes has been evaluated; however, we now know that multiple genes are often involved in medication metabolism. Here, we evaluated the ability of individual pharmacokinetic genes (CYP2C19, CYP2D6, CYP3A4) and a combinatorial pharmacogenomic test (GeneSight Psychotropic®; weighted assessment of all three genes) to predict citalopram/escitalopram blood levels in patients with MDD. Patients from the Genomics Used to Improve DEpression Decisions (GUIDED) trial who were taking citalopram/escitalopram at screening and had available blood level data were included (N=191). In multivariate analysis of the individual genes and combinatorial pharmacogenomic test separately (adjusted for age, smoking status), the F statistic for the combinatorial pharmacogenomic test was 1.7 to 2.9-times higher than the individual genes, showing that it explained more variance in citalopram/escitalopram blood levels. In multivariate analysis of the individual genes and combinatorial pharmacogenomic test together, only the combinatorial pharmacogenomic test remained significant. Overall, this demonstrates that the combinatorial pharmacogenomic test was a superior predictor of citalopram/escitalopram blood levels compared to individual genes
Bacillus thuringiensis plants expressing Cry1Ac, Cry2Ab and Cry1F are not toxic to the assassin bug, Zelus renardii
Cotton‐ and maize‐producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis (Bt), have been commercialized since 1996. Bt plants are subjected to environmental risk assessments for non‐target organisms, including natural enemies that suppress pest populations. Here, we used Cry1F‐resistant Spodoptera frugiperda (J.E. Smith) and Cry1Ac and Cry2Ab‐resistant Trichoplusia ni (Hübner) as prey for the assassin bug, Zelus renardii (Kolenati), a common predator in maize and cotton fields. In tritrophic studies, we assessed several fitness parameters of Z. renardii when it fed on resistant S. frugiperda that had fed on Bt maize expressing Cry1F or on resistant T. ni that had fed on Bt cotton expressing Cry1Ac and Cry2Ab. Survival, nymphal duration, adult weight, adult longevity and female fecundity of Z. renardii were not different when they were fed resistant‐prey larvae (S. frugiperda or T. ni) reared on either a Bt crop or respective non‐Bt crops. ELISA tests demonstrated that the Cry proteins were present in the plant at the highest levels, at lower levels in the prey and at the lowest levels in the predator. While Z. renardii was exposed to Cry1F and Cry1Ac and Cry2Ab when it fed on hosts that consumed Bt‐transgenic plants, the proteins did not affect important fitness parameters in this common and important predator
Ecological Studies of Wolves on Isle Royale, 1982-1983
Annual Report 1982-1983 (Covering the twenty-fifth year of research)https://digitalcommons.mtu.edu/wolf-annualreports/1038/thumbnail.jp
Shock Speed, Cosmic Ray Pressure, and Gas Temperature in the Cygnus Loop
Upper limits on the shock speeds in supernova remnants can be combined with
post-shock temperatures to obtain upper limits on the ratio of cosmic ray to
gas pressure (P_CR / P_G) behind the shocks. We constrain shock speeds from
proper motions and distance estimates, and we derive temperatures from X-ray
spectra. The shock waves are observed as faint H-alpha filaments stretching
around the Cygnus Loop supernova remnant in two epochs of the Palomar
Observatory Sky Survey (POSS) separated by 39.1 years. We measured proper
motions of 18 non-radiative filaments and derived shock velocity limits based
on a limit to the Cygnus Loop distance of 576 +/- 61 pc given by Blair et al.
for a background star. The PSPC instrument on-board ROSAT observed the X-ray
emission of the post-shock gas along the perimeter of the Cygnus Loop, and we
measure post-shock electron temperature from spectral fits. Proper motions
range from 2.7 arcseconds to 5.4 arcseconds over the POSS epochs and post-shock
temperatures range from kT ~ 100-200 eV. Our analysis suggests a cosmic ray to
post-shock gas pressure consistent with zero, and in some positions P_CR is
formally smaller than zero. We conclude that the distance to the Cygnus Loop is
close to the upper limit given by the distance to the background star and that
either the electron temperatures are lower than those measured from ROSAT PSPC
X-ray spectral fits or an additional heat input for the electrons, possibly due
to thermal conduction, is required.Comment: Submitted to ApJ, 7 color figure
Small conductance calcium-activated potassium current is important in transmural repolarization of failing human ventricles
BACKGROUND: The transmural distribution of apamin-sensitive small conductance Ca(2+)-activated K(+) (SK) current (IKAS) in failing human ventricles remains unclear.
METHODS AND RESULTS: We optically mapped left ventricular wedge preparations from 12 failing native hearts and 2 rejected cardiac allografts explanted during transplant surgery. We determined transmural action potential duration (APD) before and after 100 nmol/L apamin administration in all wedges and after sequential administration of apamin, chromanol, and E4031 in 4 wedges. Apamin prolonged APD from 363 ms (95% confidence interval [CI], 341-385) to 409 (95% CI, 385-434; P<0.001) in all hearts, and reduced the transmural conduction velocity from 36 cm/s (95% CI, 30-42) to 32 cm/s (95% CI, 27-37; P=0.001) in 12 native failing hearts at 1000 ms pacing cycle length (PCL). The percent APD prolongation is negatively correlated with baseline APD and positively correlated with PCL. Only 1 wedge had M-cell islands. The percentages of APD prolongation in the last 4 hearts at 2000 ms PCL after apamin, chromanol, and E4031 were 9.1% (95% CI, 3.9-14.2), 17.3% (95% CI, 3.1-31.5), and 35.9% (95% CI, 15.7-56.1), respectively. Immunohistochemical staining of subtype 2 of SK protein showed increased expression in intercalated discs of myocytes.
CONCLUSIONS: SK current is important in the transmural repolarization in failing human ventricles. The magnitude of IKAS is positively correlated with the PCL, but negatively correlated with APD when PCL is fixed. There is abundant subtype 2 of SK protein in the intercalated discs of myocytes
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