Effects of meta-chlorophenylpiperazine infusions in patients with seasonal affective disorder and healthy control subjects. Diurnal responses and nocturnal regulatory mechanisms

BACKGROUND: Multiple lines of evidence suggest that brain serotonergic systems may be disturbed in seasonal affective disorder (SAD). Previously, we found that the serotonergic agent meta-chlorophenylpiperazine (m-CPP) produced increases in activation and euphoria in depressed patients with SAD, but not in patients with SAD following light treatment or in the summer, nor in healthy control subjects in any condition. In the present study, we attempted to replicate and extend this finding using better methods. METHODS: Seventeen outpatients with SAD and 15 control subjects underwent successive 3-week periods of bright light treatment and light avoidance in a randomized order. During the third week of each condition, on 2 different occasions, subjects were admitted to the hospital for a night of sleep (core temperatures were recorded), followed by infusions of m-CPP (0.08 mg/kg) or placebo the next morning. Dependent measures included the 24-item National Institute of Mental Health Self-Rating Scale, plasma corticotropin, cortisol, prolactin, growth hormone, and norepinephrine concentrations, and core temperatures. RESULTS: Meta-chlorophenylpiperazine produced (1) significant increases in "activation-euphoria" ratings only in depressed patients with SAD in the untreated condition and (2) blunted corticotropin and norepinephrine responses in patients with SAD compared with controls across both light treatment conditions. In both groups, light treatment was associated with significant reductions in nocturnal core temperatures, which were correlated with similarly significant reductions in mean diurnal growth hormone concentrations. In patients with SAD, (1) the reductions in nocturnal core temperatures also were correlated with the reductions in baseline depression ratings and (2) the reductions in mean growth hormone concentrations were significantly smaller compared with controls. CONCLUSIONS: The abnormal m-CPP-induced activation-euphoria responses represent a replicated state marker of winter depression in patients with SAD. The blunted m-CPP-induced responsiveness of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system may represent traitlike abnormalities. The improvements in mood following light treatment in patients with SAD seem to be associated with the lowering of nocturnal core temperatures. The findings, although not easily explained based on a uniform abnormality of serotonin receptors, are nonetheless compatible with the notion that selected regions of the central nervous system are deficient in serotonin transmission during winter depression.     

Pulmonary involvement in systemic lupus erythematosus

BACKGROUND: We wanted to find out whether the borders of the blind spot depend on the surface topography of the optic disc and its surrounding area. PATIENTS AND METHODS: We therefore examined ten eyes with parapapillary atrophy adjacent to the temporal side of the disc. Fundus perimetry was performed under direct fundus control using a Rodenstock scanning laser ophthalmoscope. We examined the horizontal meridian of the optic discs in 0.5 degree steps using Goldmann IV-stimuli with 10 different degrees of brightness and the Goldmann stimulus 1, 0 dB (greatest luminance). Six eyes with symmetric, "normal" excavation served as controls. Optic disc topography was measured with the Heidelberg Retina Tomograph (HRT). RESULTS: Stimuli with a large luminance power (Goldmann IV, 4 dB) were seen up to 0.8 degree centrally (i.e., towards the optic disc center) from the temporal edge of the parapapillary atrophy, but up to 1.9 degrees centrally from the nasal optic disc border (P < 0.01). Horizontal HRT section profiles of the optic disc consistently showed prominent nasal disc borders contrasting with a shallow excavation within the temporal parapapillary atrophy. In all six subjects with a normally shaped disc there was no such "nasotemporal asymmetry." CONCLUSIONS: The size of scotomas depends on the surface topography of the tested area. The prominent nasal part of the optic disc appears less "blind" than the shallow temporal part, probably due to more intensive light scattering by the prominent nasal part of the disc.     

Cucurbit[8]uril‐Regulated Colloidal Dispersions Exhibiting Photocontrolled Rheological Behavior

In situ photocontrol over shear‐thickening of condensed colloidal dispersions is of paramount importance in a wide range of applications including process technology and photorheological fluids. Its development and practicability, however, are hampered by the lack of well‐designed photoresponsive systems. Here, a colloidal suspension whose rheological behavior is readily switchable between shear‐thinning and shear‐thickening using an external light stimulus is reported. This smart colloidal solution contains hybrid raspberry‐like colloids prepared by employing cucurbit[8]uril as a supramolecular linker to assemble functional Fe₃O₄ nanoparticles onto a silica core. The formed raspberry colloids are photoresponsive and can be reversibly disassembled under UV irradiation.     

Design Principles for Aqueous Interactive Materials: Lessons from Small Molecules and Stimuli-Responsive Systems

Interactive materials are at the forefront of current materials research with few examples in the literature. Researchers are inspired by nature to develop materials that can modulate and adapt their behavior in accordance with their surroundings. Stimuli-responsive systems have been developed over the past decades which, although often described as “smart,” lack the ability to act autonomously. Nevertheless, these systems attract attention on account of the resultant materials' ability to change their properties in a predicable manner. These materials find application in a plethora of areas including drug delivery, artificial muscles, etc. Stimuli-responsive materials are serving as the precursors for next-generation interactive materials. Interest in these systems has resulted in a library of well-developed chemical motifs; however, there is a fundamental gap between stimuli-responsive and interactive materials. In this perspective, current state-of-the-art stimuli-responsive materials are outlined with a specific emphasis on aqueous macroscopic interactive materials. Compartmentalization, critical for achieving interactivity, relies on hydrophobic, hydrophilic, supramolecular, and ionic interactions, which are commonly present in aqueous systems and enable complex self-assembly processes. Relevant examples of aqueous interactive materials that do exist are given, and design principles to realize the next generation of materials with embedded autonomous function are suggested.     

Adjoint sensitivity analysis and optimization of hysteretic dynamic systems with nonlinear viscous dampers

In this paper we discuss the adjoint sensitivity analysis and optimization of hysteretic systems equipped with nonlinear viscous dampers and subjected to transient excitation. The viscous dampers are modeled via the Maxwell model, considering at the same time the stiffening and the damping contribution of the dampers. The time-history analysis adopted for the evaluation of the response of the systems relies on the Newmark-β time integration scheme. In particular, the dynamic equilibrium in each time-step is achieved by means of the Newton-Raphson and the Runge-Kutta methods. The sensitivity of the system response is calculated with the adjoint variable method. In particular, the discretize-then-differentiate approach is adopted for calculating consistently the sensitivity of the system. The importance and the generality of the sensitivity analysis discussed herein is demonstrated in two numerical applications: the retrofitting of a structure subject to seismic excitation, and the design of a quarter-car suspension system. The MATLAB code for the sensitivity analysis considered in the first application is provided as “Supplementary Material”.     

Thin-film composite nanofiltration membranes prepared by electropolymerization

A novel approach to preparation of composite asymmetric nanofiltration membranes is reported based on a thin selective layer deposited by electropolymerization (EP) on top of an asymmetrically porous and electronically conductive porous support. Support films with ultrafiltration characteristics were cast from a concentrated dispersion of carbon black particles, a few tens of nanometers large, in a solution of polysulfone followed by precipitation in a non-solvent bath (phase inversion). Composite membranes with poly(phenylene oxide) and polyaniline thin top layers were prepared by EP deposition from solutions of phenol and aniline, respectively, of which polyaniline film demonstrated a dense uniform structure and water flux and rejection to sucrose and magnesium sulfate in the nanofiltration range.     

Targeted blue nanoparticles as photoacoustic contrast agent for brain tumor delineation

Distinguishing a tumor from non-neoplastic tissue is a challenging task during cancer surgery. Several attempts have been made to use visible or fluorescent agents to aid in the visualization of a tumor during surgery. We describe a novel method to delineate brain tumors, using a highly sensitive photoacoustic imaging technique that is enhanced by tumor-targeting blue nanoparticles serving as a contrast agent. Experiments on phantoms and on rat brains, ex vivo, demonstrate the high sensitivity of photoacoustic imaging in delineating tumors containing contrast agent at a concentration much lower than needed for visualization by the naked eye. The limit of detection of the system for the nanoparticles is about 0.77 μg/mL in water (equivalent to 0.84 μmol/L Coomassie Blue dye). The present exploratory study suggests that photoacoustic imaging, when used with strongly optical absorbing contrast agents, could facilitate cancer surgery intraoperatively by revealing the distribution and extent of the tumor.