Opioid-receptor (OR) signaling cascades in rat cerebral cortex and model cell lines: the role of plasma membrane structure.

Large number of extracellular signals is received by plasma membrane receptors which, upon activation, transduce information into the target cell interior via trimeric G-proteins (GPCRs) and induce activation or inhibition of adenylyl cyclase enzyme activity (AC). Receptors for opioid drugs such as morphine (micro-OR, delta-OR and kappa-OR) belong to rhodopsin family of GPCRs. Our recent results indicated a specific up-regulation of AC I (8-fold) and AC II (2.5-fold) in plasma membranes (PM) isolated from rat brain cortex exposed to increasing doses of morphine (10-50 mg/kg) for 10 days. Increase of ACI and ACII represented the specific effect as the amount of ACIII-ACIX, prototypical PM marker Na, K-ATPase and trimeric G-protein alpha and beta subunits was unchanged. The up-regulation of ACI and ACII faded away after 20 days since the last dose of morphine. Proteomic analysis of these PM indicated that the brain cortex of morphine-treated animals cannot be regarded as being adapted to this drug because significant up-regulation of proteins functionally related to oxidative stress and alteration of brain energy metabolism occurred. The number of delta-OR was increased 2-fold and their sensitivity to monovalent cations was altered. Characterization of delta-OR-G-protein coupling in model HEK293 cell line indicated high ability of lithium to support affinity of delta-OR response to agonist stimulation. Our studies of PM structure and function in context with desensitization of GPCRs action were extended by data indicating participation of cholesterol-enriched membrane domains in agonist-specific internalization of delta-OR. In HEK293 cells stably expressing delta-OR-G(i)1alpha fusion protein, depletion of PM cholesterol was associated with the decrease in affinity of G-protein response to agonist stimulation, whereas maximum response was unchanged. Hydrophobic interior of isolated PM became more "fluid", chaotically organized and accessible to water molecules. Validity of this conclusion was supported by the analysis of an immediate PM environment of cholesterol molecules in living delta-OR-G(i)1alpha-HEK293 cells by fluorescent probes 22- and 25-NBD-cholesterol. The alteration of plasma membrane structure by cholesterol depletion made the membrane more hydrated. Understanding of the positive and negative feedback regulatory loops among different OR-initiated signaling cascades (micro-, delta-, and kappa-OR) is crucial for understanding of the long-term mechanisms of drug addiction as the decrease in functional activity of micro-OR may be compensated by increase of delta-OR and/or kappa-OR signaling.

Plasma membrane density of GABA(B)-R1a, GABA(B)-R1b, GABA-R2 and trimeric G-proteins in the course of postnatal development of rat brain cortex.

With the aim to understand the onset of expression and developmental profile of plasma membrane (PM) content /density of crucial components of GABA(B)-R signaling cascade, GABA(B)-R1a, GABA(B)-R1b, GABA(B)-R2, G(i)1/G(i)2alpha, G(i)3alpha, G(o)alpha, G(z)alpha and Gbeta subunit proteins were determined by quantitative immunoblotting and compared in PM isolated from brain cortex of rats of different ages: between postnatal-day-1 (PD1) and 90 (PD90). PM density of GABA(B)-R1a, GABA(B)-R2, G(i)1/G(i)2alpha, G(i)3alpha, G(o)alpha, G(z)alpha and Gbeta was high already at birth and further development was reflected in parallel decrease of both GABA(B)-R1a and GABA(B)-R2 subunits. The major decrease of GABA(B)-R1a and GABA(B)-R2 occurred between the birth and PD15: to 55 % (R1a, **) and 51 % (R2, **), respectively. Contrarily, PM level of the cognate G-proteins G(i)1/G(i)2alpha, G(i)3alpha, G(o)alpha, G(z)alpha and Gbeta was unchanged in the course of the whole postnatal period of brain cortex development. Maturation of GABA(B)-R cascade was substantially different from ontogenetic profile of prototypical plasma membrane marker, Na, K-ATPase, which was low at birth and further development was reflected in continuous increase of PM density of this enzyme. Major change occurred between the birth and PD25. In adult rats, membrane content of Na, K-ATPase was 3-times higher than around the birth.

Ontogenetic development of GABA(B)-receptor signaling cascade in plasma membranes isolated from rat brain cortex; the number of GABA(B)-receptors is high already shortly after the birth.

Our data indicate the significant intrinsic efficacy of GABA(B)-receptors in rat brain cortex already at birth (PD1, PD2). Subsequently, baclofen- and SKF97541-stimulated G-protein activity, measured by agonist-stimulated, high-affinity [(35)S]GTPgammaS binding assay, was increased; the highest level of both baclofen and SKF97541-stimulated [(35)S]GTPgammaS binding was detected between PD10 and PD15. In older rats, baclofen- and SKF97541-stimulated [(35)S]GTPgammaS binding was continuously decreased so, that the level in adult, 90-days old animals, was not different from that in newborn animals. The potency of G-protein response to baclofen (characterized by EC(50) values) was also high at birth but unchanged by further postnatal development. An individual variance among different agonists was observed in this respect as the potency of SKF97541 response was decreased between the birth and adulthood. Accordingly, the highest plasma membrane density of GABA(B)-R, determined by saturation binding assay with antagonist [(3)H]CGP54626, was measured in 1-day old animals (2.27+/-0.08 pmol · mg(-1)). The further development was reflected in a decrease of [(3)H]CGP54626 binding as the B(max) values of 1.38+/-0.05 and 0.93+/-0.04 pmol · mg(-1) were determined in PM isolated from 13- and 90-days old rats, respectively.

Motion-driven sensing and biosensing using electrochemically propelled nanomotors.

Electrochemically-propelled nanomotors offer considerable promise for developing new and novel bioanalytical and biosensing strategies based on the direct isolation of target biomolecules or changes in their movement in the presence of target analytes. For example, receptor-functionalized nanomotors offer direct and rapid target isolation from raw biological samples without preparatory and washing steps. Microtube engines functionalized with ss-DNA, aptamer or antibody receptors are particularly useful for the direct isolation of nucleic acids, proteins or cancer cells, respectively. A new nanomotor-based signal transduction involving measurement of speed and distance travelled by nanomotors, offers highly sensitive, rapid, simple and low cost detection of target biomarkers, and a new dimension of analytical information based on motion. The resulting distance signals can be easily visualized by optical microscope (without any sophisticated analytical instrument) to reveal the target presence and concentration. The attractive features of the new micromachine-based target isolation and signal transduction protocols reviewed in this article offer numerous potential applications in biomedical diagnostics, environmental monitoring, and forensic analysis.

A faint type of supernova from a white dwarf with a helium-rich companion.

Supernovae are thought to arise from two different physical processes. The cores of massive, short-lived stars undergo gravitational core collapse and typically eject a few solar masses during their explosion. These are thought to appear as type Ib/c and type II supernovae, and are associated with young stellar populations. In contrast, the thermonuclear detonation of a carbon-oxygen white dwarf, whose mass approaches the Chandrasekhar limit, is thought to produce type Ia supernovae. Such supernovae are observed in both young and old stellar environments. Here we report a faint type Ib supernova, SN 2005E, in the halo of the nearby isolated galaxy, NGC 1032. The 'old' environment near the supernova location, and the very low derived ejected mass ( approximately 0.3 solar masses), argue strongly against a core-collapse origin. Spectroscopic observations and analysis reveal high ejecta velocities, dominated by helium-burning products, probably excluding this as a subluminous or a regular type Ia supernova. We conclude that it arises from a low-mass, old progenitor, likely to have been a helium-accreting white dwarf in a binary. The ejecta contain more calcium than observed in other types of supernovae and probably large amounts of radioactive (44)Ti.

Field trial of a diagnostic axis for defense mechanisms for DSM-IV.

Following critiques that the DSM multiaxial system lacks psychodynamic information useful for treatment, an axis for defense mechanisms was developed for DSM-IV, including up to 7 individual defenses from a glossary of 27, and 3 predominant defense levels from a list of 7. We tested the feasibility, reliability, and discriminability of the proposed axis. Clinician and psychiatric resident volunteers were trained at two U.S. and one Norwegian sites. After conducting initial interviews on 107 patients, they rated the DSM-III-R and defense axes, as did a second blind rater. Median kappa reliabilities were .42 (individual defenses), and .47 (defense levels). A summary measure, Overall Defensive Functioning (ODF), had similar reliability to current GAF (IR .68 vs. .62), similar 1-month stability (.75 vs. .78), but greater 6-month stability (.51 vs. .17). Independent of Axis III, ODF had small to moderate associations with other Axes and symptoms. Our findings indicate that the defense axis is a feasible, acceptably reliable, and nonredundant addition to DSM-IV, which may prove useful for planning and conducting treatment.

Refining a method of identifying CUNY Medical School graduates practicing in underserved areas.

PURPOSE: To determine what percentage of graduates from the City University of New York (CUNY) Medical School/Sophie Davis School of Biomedical Education practiced in underserved areas of New York State and, in the process, to develop a reliable way of collecting and verifying the information needed to carry out such an outcomes study. METHOD: The study group consisted of the 414 CUNY graduates who had completed their MD degrees by 1986. Addresses of graduates' practices were confirmed for 79% of the graduates, 49% of whom practiced in New York State. New York State zip codes were used as a way to identify underserved areas throughout the state. RESULTS: Of the 160 graduates with practices in New York State, 33% had practices in underserved areas (and 81% of these were located in New York City). In all, 26% of the whites, 73% of the African Americans, 43% of the Asian Americans, 50% of the Latinos, 34% of the women, and 32% of the men had practices in underserved areas. CONCLUSION: The graduates' race-ethnicity was an important factor in the likelihood of their practicing in an underserved area, whereas gender was not, a finding consistent with previous studies. Medical schools and residency programs need to institute long-term programs to track the career paths of all their graduates so that questions about the proportions of graduates in underserved areas will be relatively easy to answer.

Protection of xenogeneic cardiac endothelium from human complement by expression of CD59 or DAF in transgenic mice.

We investigated the ability of membrane-bound human complement regulatory proteins to control complement-driven humoral immune reactions on murine microvasculature. The human complement regulatory proteins CD59 and DAF were expressed using heterologous promoters in a variety of tissues in transgenic mice. Animals expressing these gene products are healthy and exhibit significant levels of endothelial cell expression of CD59 and DAF in cardiac muscle. Transgenic hearts perfused with human plasma exhibited profound reductions in the level of complement deposition compared with nontransgenic controls. We have also produced transgenic pigs that express these two human genes. Our results indicate that expression of complement regulatory proteins can control activation of complement and suggest that these proteins may have therapeutic applications in some inflammatory diseases and in the development of xenogeneic organs for human transplantation.

[Amyloidosis in the autopsy data from a general hospital of Leningrad]. / Amiloidoz po dannym autopsii v mnogoprofil'noi bol'nitse Leningrada.

Over the recent 20 years the incidence of amyloidosis did not undergo any noticeable changes, accounting for 1.48% of the total number of autopsies in 1964-1968 and for 1.52% in 1984-1988 (P less than 0.5). The number of cases of the clinically unrecognized amyloidosis increased from 37.5% in the first period to 52.18% in the second one. In most cases amyloidosis affects the kidneys (94.9%), spleen (58.2%), liver (48%) and then, in the descending order, there follow adrenals, intestine, heart, pancreas and other organs (the total data for both the periods).

Inquiry mode, occupational stress, and preferred leadership style among American elementary school teachers.

The relationship between teachers' cognitive styles and the kind of leadership style they prefer and the types of occupational stress they experience was explored by obtaining self-reports from 70 elementary school teachers. Analytic teachers preferred principals who were task rather than relationship oriented. Preferences in leadership style appeared to be related to subjects' tendencies to perceive and evaluate situations in particular ways. Compatibility with a principal's leadership style may have depended on how closely the style matched a teacher's fundamental affective and cognitive characteristics.

Backpropagating neurons from bichromatic interaction with a three-level system.

Optical implementation of a backpropagating neuron by means of a nonlinear Fabry-Perot etalon requires thresholding a forward signal beam while the transmittance of a backpropagating beam is multiplied by the differential of the forward signal. This is achievable by inputting a bichromatic field to a three-level system in an optical cavity. The response characteristics of this device have the added possibility of adaptability of the threshold by the backward probe input intensity.

The relationship between aerobic activity and cognitive performance under stress.

This study examined the relationship between regular aerobic activity and cognitive performance under stress when personality and inherent aptitude were statistically controlled. Aerobically conditioned subjects have been shown to mediate the physiological response to stress under physical challenge. Would aerobically conditioned subjects also respond more efficiently to psychological stress under cognitive challenge? Forty volunteers completed a battery of personality and aptitude measures and then completed two cognitive tasks (written tests of logic), one under a condition of no stress, the other while being verbally pressured by a test monitor. Heart rate and blood pressure were measured during and after each cognitive task. Contrary to the experimental hypothesis, aerobic activity was related to inferior cognitive performance and to elevated blood pressure under stress. Inherent cognitive aptitude and personality traits emerged as far more important correlates of cognitive performance under stress than did the level of exercise.

Illicit methamphetamine: analysis, synthesis, and availability.

Methamphetamine has been marketed illicitly since the 1960s. Much of the street material was illicitly synthesized. Although methamphetamine quality was variable in the past decade, it has emerged since 1978 as the only street stimulant which is likely to contain what it purports to contain. Although there is a small volume of legitimate methamphetamine still made by the pharmaceutical industry, most material analyzed by street-drug laboratories appears to have been illegitimately synthesized and not diverted. For a decade, relatively little methamphetamine was submitted to street-drug analytical labs. In recent years, although the absolute volume of methamphetamine submissions changed little, this drug made up the bulk of alleged stimulant samples submitted to such facilities because of the paucity of amphetamine submissions. Methamphetamine synthesis and use appears to constitute a small but continuing portion of the illicit drug market.

Addictive personality factors.

This study was designed to compare mean scores obtained by alcoholics, compulsive gamblers, smokers, chronic joggers, and control subjects on six subfactors of the MacAndrew Alcoholism Scale. Results indicated that some MacAndrew factors may be more sensitive to additive pathology than others. Alcoholics emerged as the most pathological group, in terms of scores on the Cognitive Impairment, Social Maladjustment, and Risk Taking scales. Gamblers and smokers appeared to be distinctly different, more socially oriented addicts. Frequency of jogging was negatively related to measures of addiction but positively related to measures of compulsiveness.