Increased thin-spine density in frontal cortex pyramidal neurons in a genetic rat model of schizophrenia-relevant features.

The cellular mechanisms altered during brain wiring leading to cognitive disturbances in neurodevelopmental disorders remain unknown. We have previously reported altered cortical expression of neurodevelopmentally regulated synaptic markers in a genetic animal model of schizophrenia-relevant behavioral features, the Roman-High Avoidance rat strain (RHA-I). To further explore this phenotype, we looked at dendritic spines in cortical pyramidal neurons, as changes in spine density and morphology are one of the main processes taking place during adolescence. An HSV-viral vector carrying green fluorescent protein (GFP) was injected into the frontal cortex (FC) of a group of 11 RHA-I and 12 Roman-Low Avoidance (RLA-I) male rats. GFP labeled dendrites from pyramidal cells were 3D reconstructed and number and types of spines quantified. We observed an increased spine density in the RHA-I, corresponding to a larger fraction of immature thin spines, with no differences in stubby and mushroom spines. Glia cells, parvalbumin (PV) and somatostatin (SST) interneurons and surrounding perineuronal net (PNN) density are known to participate in FC and pyramidal neuron dendritic spine maturation. We determined by stereological-based quantification a significantly higher number of GFAP-positive astrocytes in the FC of the RHA-I strain, with no difference in microglia (Iba1-positive cells). The number of inhibitory PV, SST interneurons or PNN density, on the contrary, was unchanged. Results support our belief that the RHA-I strain presents a more immature FC, with some structural features like those observed during adolescence, adding construct validity to this strain as a genetic behavioral model of neurodevelopmental disorders.

MEF2C transcription factor is associated with the genetic and epigenetic risk architecture of schizophrenia and improves cognition in mice.

Large-scale consortia mapping the genomic risk architectures of schizophrenia provide vast amounts of molecular information, with largely unexplored therapeutic potential. We harnessed publically available information from the Psychiatric Genomics Consortium, and report myocyte enhancer factor 2C (MEF2C) motif enrichment in sequences surrounding the top scoring single-nucleotide polymorphisms within risk loci contributing by individual small effect to disease heritability. Chromatin profiling at base-pair resolution in neuronal nucleosomes extracted from prefrontal cortex of 34 subjects, including 17 cases diagnosed with schizophrenia, revealed MEF2C motif enrichment within cis-regulatory sequences, including neuron-specific promoters and superenhancers, affected by histone H3K4 hypermethylation in disease cases. Vector-induced short- and long-term Mef2c upregulation in mouse prefrontal projection neurons consistently resulted in enhanced cognitive performance in working memory and object recognition paradigms at baseline and after psychotogenic drug challenge, in conjunction with remodeling of local connectivity. Neuronal genome tagging in vivo by Mef2c-Dam adenine methyltransferase fusion protein confirmed the link between cognitive enhancement and MEF2C occupancy at promoters harboring canonical and variant MEF2C motifs. The multilayered integrative approaches presented here provide a roadmap to uncover the therapeutic potential of transcriptional regulators for schizophrenia and related disorders.

Functional selectivity in GPCR heterocomplexes.

G protein-coupled receptors (GPCRs) can couple to more than one signaling pathway. Biophysical studies and pharmacological theory indicate that they exist in different active conformations that differ in their capacity to activate specific signaling pathways. Individual agonists stabilize particular active conformations and thereby can differ in their relative activation of different signaling pathways coupled to the same receptor, a phenomenon referred to as functional selectivity. Many pairs of GPCRs have been shown to interact and form heterocomplexes in vitro and in vivo. Recent studies implicate these complexes in the responses to some therapeutic drugs and drugs of abuse, and raise the possibility that they may be involved in mediating functional selectivity.

Haemodynamic strategy for treatment of diastolic anterograde giacomini varicose veins.

OBJECTIVES: To assess the diagnosis and outcome of a haemodynamic strategy for the treatment of primary varicose veins associated with anterograde diastolic flow (ADF) in the Giacomini vein (GV). METHODS: ADF in the GV, with the escape point located at the saphenopopliteal junction, was demonstrated in 15 patients (15 limbs) by duplex ultrasound. No other escape points were seen in this group. ADF was defined as the flow present in the relaxing phase after isometric contraction of the lower limb, measured in the standing position. Duplex and clinical follow-up was performed prospectively at 1 week, at 1, 3, 6, and 12 months and once per year thereafter, between 1998 and 2001. Surgery consisted of flush division of the GV from the small saphenous vein (SSV) and division of the incompetent collateral veins from the GV. RESULTS: GV diameter showed an average reduction from 6 to 4 mm 33 months after surgery. Fourteen patients (93%) showed no symptoms or varicose veins. GV reconnection and recurrent ADF was demonstrated in two patients (13%). CONCLUSIONS: ADF is a rare condition associated with primary varicose veins. ADF occurs when there is a closed venovenous shunt with recirculation in the muscular diastole. This implies that, although a part of the circuit is ascendant, the re-entry point must be located downstream to the escape point. Accurate duplex assessment is required to distinguish this atypical haemodynamic condition from an abnormal systolic circuit bypassing a deep vein obstruction. Interruption of the GV above its junction with the SSV abolished ADF with an acceptable rate of recurrences.

Durability of reflux-elimination by a minimal invasive CHIVA procedure on patients with varicose veins. A 3-year prospective case study.

OBJECTIVES: to assess the outcome of a conservative and haemodynamic method for insufficient veins on an ambulatory basis (French acronym, "CHIVA") with preservation of the greater saphenous vein (GSV) for treatment of primary varicose veins. METHODS: duplex incompetence of the sapheno-femoral junction (SFJ) and the GSV trunk, with the re-entry perforating point located on a GSV tributary was demonstrated in 58 patients with varices (58 limbs). The re-entry point was defined as the perforator, whose compression of the superficial vein above its opening eliminates reflux in the GSV. Duplex scanning was performed preoperatively and at 7 days, and patients were followed prospectively at 1, 3, 6, 12, 24, and 36 months after CHIVA. Operation consisted in flush ligation and division from the GSV of the tributary containing the re-entry perforating vein (no additional high ligation is included). If reflux returned, SFJ interruption was performed in a second surgical procedure. RESULTS: the GSV diameter showed an average reduction from 6.6 to 3.9 mm 36 months after surgery. Reflux in the GSV system was demonstrated in all but five (8%) patients. Of the 53 patients with recurrent reflux, 46 underwent SFJ interruption. CONCLUSIONS: elimination of reflux in the GSV after the interruption of insufficient collaterals is only temporary.

Neurotransmitter receptor-mediated activation of G-proteins in brains of suicide victims with mood disorders: selective supersensitivity of alpha(2A)-adrenoceptors.

Abnormalities in the density of neuroreceptors that regulate norepinephrine and serotonin release have been repeatedly reported in brains of suicide victims with mood disorders. Recently, the modulation of the [(35)S]GTPgammaS binding to G-proteins has been introduced as a suitable measure of receptor activity in postmortem human brain. The present study sought to evaluate the function of several G-protein coupled receptors in postmortem brain of suicide victims with mood disorders. Concentration-response curves of the [(35)S]GTPgammaS binding stimulation by selective agonists of alpha(2)-adrenoceptors, 5-HT(1A) serotonin, mu-opioid, GABA(B), and cholinergic muscarinic receptors were performed in frontal cortical membranes from 28 suicide victims with major depression or bipolar disorder and 28 subjects who were matched for gender, age and postmortem delay. The receptor-independent [(35)S]GTPgammaS binding stimulation by mastoparan and the G-protein density were also examined. The alpha(2A)-adrenoceptor-mediated stimulation of [(35)S]GTPgammaS binding with the agonist UK14304 displayed a 4.6-fold greater sensitivity in suicide victims than in controls, without changes in the maximal stimulation. No significant differences were found in parameters of 5-HT(1A) serotonin receptor and other receptor-mediated [(35)S]GTPgammaS binding stimulations. The receptor-independent activation of G-proteins was similar in both groups. Immunoreactive densities of G(alphai1/2)-, G(alphai3)-, G(alphao)-, and G(alphas)-proteins did not differ between suicide victims and controls. In conclusion, alpha(2A)-adrenoceptor sensitivity is increased in the frontal cortex of suicide victims with mood disorders. This receptor supersensitivity is not related to an increased amount or enhanced intrinsic activity of G-proteins. The new finding provides functional support to the involvement of alpha(2)-adrenoceptors in the pathogenesis of mood disorders.

Comparison of clinical outcome of stripping and CHIVA for treatment of varicose veins in the lower extremities.

The purpose of this nonrandomized case-review study was to compare the outcome of stripping and CHIVA for treatment of varicose veins in the lower extremities in our department. Outcome was evaluated by independent physicians. A total of 85 patients underwent saphenous vein stripping in association with phlebectomy and 90 patients underwent CHIVA cure. The duration of follow-up was 3 years. Study criteria were (1) presence of varicose veins as a cause of failure (1.1% in the CHIVA group vs. 15.3% in the stripping group), (2) appearance of telangiectasia (8.9% in the CHIVA group vs. 65.9% in the stripping group), (3) patient dissatisfaction rate (3.3% in the CHIVA group vs. 16.5% in the stripping group), (4) postoperative symptoms as a cause of failure (1.1% in the CHIVA group vs. 21.2% in the stripping group), and (5) saphenous nerve injury (1 patient in the CHIVA group vs. 16 in the stripping group). Differences between all five criteria were significantly in favor of the CHIVA group as compared to saphenous vein stripping with phlebectomy. Clinical results at 3 years are better for patients treated with CHIVA than stripping with regard to presence of varicose veins, clinical symptoms, presence of telangiectasia, cosmetic satisfaction, and neurologic complications. Data in our series of CHIVA treatments are comparable to those reported in the literature and better than those described in three series of stripping procedures with 3-year follow-up. A prospective randomized study is now underway to confirm these findings.

mu-opioid receptor and alpha2-adrenoceptor agonist stimulation of [35S]GTPgammaS binding to G-proteins in postmortem brains of opioid addicts.

Repeated opioid administration has been associated in human brain with unaltered density of mu-opioid receptors (agonist radioligand binding sites and immunodetected receptor protein). These receptors are coupled to Gi/Go-proteins, which are increased in brain of heroin addicts. To assess the activity of G-proteins and their coupling to receptors after chronic opioid abuse, [35S]GTPgammaS binding was quantified in postmortem prefrontal cortices of 15 opioid-dependent subjects and 15 matched controls. The stimulation of [35S]GTPgammaS binding by the mu-opioid receptor agonist DAMGO or the alpha2-adrenoceptor agonist UK14304 was used as a functional measure of the status of the receptor-G-protein coupling. [35S]GTPgammaS binding basal values were similar in opioid addicts (819+/-83 fmol mg-1 of protein) and controls (918+/-106 fmol mg(-1) of protein). In opioid addicts, [35S]GTPgammaS binding stimulation by DAMGO showed a maximal effect (62+/-8%) and a potency (EC50 = 1.09+/-0.26 microM) that did not differ from the maximal effect (60+/-12%) and potency (EC50 = 2.01+/-0.58 microM) in controls. In opioid addicts, [35S]GTPgammaS binding stimulation by UK14304 was not different in maximal effect (28+/-3%) from controls (32+/-8%), but the potency of the agonist was decreased (EC50 = 4.36+/-1.81 microM) when compared with controls (EC50 = 0.41+/-0.15 microM). The results provide a direct evidence of an apparent normal functional activity of brain mu-opioid receptors (Gi/Go-protein coupling) during the opioid dependence process in humans. The data also demonstrate a functional uncoupling of alpha2-adrenoceptors from G-proteins, which indicates a heterologous desensitization of these receptors. This finding could represent an adaptive mechanism against the decreased noradrenergic activity induced by the chronic presence of opioid drugs.

Characterization of receptor-mediated [35S]GTPgammaS binding to cortical membranes from postmortem human brain.

The [35S]GTPgammaS binding assay represents a functional approach to assess the coupling between receptors and G-proteins. The optimal conditions for [35S]GTPgammaS binding to human brain homogenates were established in postmortem samples of prefrontal cortex. The influence of protein content, incubation time, GDP, Mg(2+), and NaCl concentrations on the [35S]GTPgammaS binding were assessed in the absence and presence of the alpha(2)-adrenoceptor agonist UK14304 5-bromo-N-(4,5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine). In conditions of 50 microM GDP and 100 mM NaCl, UK14304 increased the apparent affinity of the specific [35S]GTPgammaS binding without changing the apparent density. Concentration-response curves to agonists of alpha(2)-adrenoceptors, mu-opioid, 5-HT(1A), cholinergic muscarinic, and GABA(B) receptors displayed, in the presence of NaCl, maximal stimulations between 24% and 61% with EC(50) values in the micromolar range. Selective antagonists shifted to the right the agonist-induced stimulation curves. The G(i)/G(o)-protein alkylating agent N-ethylmaleimide decreased basal [35S]GTPgammaS binding in a concentration-dependent manner and inhibited the stimulation induced by the different agonists. In cortical sections, [35S]GTPgammaS binding to gray matter was stimulated by the agonist UK14304. The present study demonstrates that functional studies of the receptor coupling to G(i)/G(o)-proteins can be performed in postmortem human brain samples.

Autoradiography of receptor-activated G-proteins in post mortem human brain.

The agonist-stimulated guanosine 5'-(gamma-[(35)S]thio)triphosphate binding assay was used to anatomically localize receptor-activated G-proteins by autoradiography in post mortem human brain. The optimal conditions for guanosine 5'-(gamma-[(35)S]thio)triphosphate binding to human brain sections were established in post mortem samples of the prefrontal cortex, hippocampus, basal ganglia, brainstem and cerebellar cortex. An excess of GDP (2mM) was required to decrease basal activity and obtain effective stimulation by specific agonists. guanosine 5'-(gamma-[(35)S]Thio)triphosphate binding was increased after stimulation with specific agonists of different G-protein-coupled receptors. They include cannabinoid (WIN55212-2), mu-opioid ([D-Ala(2),N-Me-Phe(4), Gly(5)-ol]enkephalin), serotonin-1A [(+/-)-8-hydroxy-2-(di-n-propylamino)tetralin] and serotonin-1B/1D (sumatriptan), cholinergic muscarinic receptors (carbachol) and alpha(2)-adrenoceptors (UK14304). Such stimulation reached 1458%, 440%, 188%, 219%, 61% and 339%, respectively, over the basal levels. In tissue sections, the use of the above-mentioned agonists (10(-4)M) showed patterns of anatomical distribution similar to those already described by receptor autoradiography, with high densities over the hippocampus (serotonin-1A receptors), cortex (alpha(2)-adrenoceptors) and striatum (mu-opioid receptors). The highest binding levels were reached with the cannabinoid receptor agonist in most of the analysed brain regions. Carbachol produced only moderate stimulation of those same regions. The blockage of agonist-stimulated guanosine 5'-(gamma-[(35)S]thio)triphosphate binding by selective antagonists verified that the effect was receptor mediated. This technique provides a method to identify modifications of the receptor-mediated activation of G-proteins in post mortem human brain with anatomical resolution. It also provides valuable information on the level of drug efficacy in the human species.

[Distal bypass to the critical ischemia]. / Bypass distal a la poplítea en la isquemia crítica.

Possibilities from the distal popliteal by-pass practiced with the purpose to conserve the extremity in cases of critical ischaemia at lower limbs are analyzed. A variant from the III-Fountaine-stage based on an haemodynamic criterium was established. Authors's experience with such distal by-pass is exposed and indications and results are analyzed.

[New criteria for the classification of the popliteal artery entrapment syndrome. Our experience with 14 extremities]. / Nuevos criterios de clasificación del síndrome de atrapamiento de la arteria poplítea. Nuestra experiencia sobre 14 extremidades.

Authors explain their experiences with eight patients (14 affected limbs) with a popliteal artery entrapment syndrome. Classification, diagnosis and treatment were reviewed. Six limbs, with any malformation and presenting as a unique sign an important hypertrophy of their intern gastrocnemius muscle, couldn't be classified. As a result, a new classification of this pathology is presented being based on the anatomical and arteriographic aspects as well as oh the surgical indication. The important correlation between anomaly, physical complexion typus athletic and sports is noted.

[An etiopathogenetic and prognostic study of sudden sensorineural hypoacusis]. / Aportación al estudio etiopatogénico y pronóstico de la hipoacusia neurosensorial brusca.

From October 1987 till November 1989 the AA. have studied 40 cases with Sensorineural sudden hypoacusis. The control term varied between 3 months and 2 years. The whole group followed an scheduled prospective protocol with the aim of find out the more significative factors regarding the etiology and prognostic of the process. On the other hand, minimize the cost of explorations, spare nuisances to the patients and select the most reliable methods were the purposes of the AA.

Nasal myiasis due to Oestrus ovis larvae.

Herein we report our experiences in managing nasal infestation due to fly larvae in an urban population. The nasosinus location is infrequently seen in cases with human infection. The life cycle of the fly (Oestrus ovis) is discussed in view of the clinical features of our case.