Role of interoceptive fear and maladaptive attention and behaviors in the escalation of psychopathology-a network analysis.

The complex interplay of fear, attention, and behavior toward bodily sensations with psychopathological symptoms and how they mutually influence and potentially reinforce one another remains to be fully elucidated. In this study, we used a network analytical approach to unravel these complex interactions. Specifically, we aimed to identify central symptoms and etiologically relevant factors that might be associated with anxiety and depressive core symptoms. To this end, the following clusters were assessed in 791 adults: interoceptive fear, interoceptive attention, maladaptive behaviors related to bodily sensations, and core symptoms of anxiety and depression. This network was modeled using a Gaussian Graphical Model. Central variables (nodes) were identified using centrality indices and bridge analysis. Self-examination and attention to bodily sensations emerged as central nodes. Moreover, time spent paying attention to bodily sensations, fear of anxiety-related sensations, and self-examination were identified as central bridge nodes, that is, central nodes connecting psychopathologically relevant symptom clusters. The present study indicates that fear of bodily sensations, the amount of attention and time spent focusing on somatic sensations, and self-examination are central factors. The findings suggest potential targets for future longitudinal studies on the impact of these factors for the escalation of anxiety and depressive symptoms.

Central variables were identified through centrality indices and bridge analysisAttention to bodily sensations and self-examination were identified as central nodesFear of bodily sensations and self-examination emerged as central bridge nodesTime spent paying attention to body sensations also emerged as central bridge nodeResults suggest possible targets for future experimental and longitudinal research.

Long-term changes in serum levels of lipoproteins in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting approximately 5% of children worldwide. The causal mechanisms of ADHD remain unclear as the aetiology of this disorder seems to be multifactorial. One research field addresses the impact on lipid metabolism and particularly serum lipid fractions on the development of ADHD symptoms. This post hoc analysis aimed to investigate long-term changes in serum levels of lipoproteins in children and adolescents with ADHD and controls. Data of German children and adolescents from the nationwide and representative "Kinder- und Jugendgesundheitssurvey (KiGGS)" study were analysed at baseline and at a ten-year follow-up. At the two time points, participants in the control group were compared with those in the ADHD group, both before and after propensity score matching. Differences in total cholesterol, low-density lipoproteins (LDL), high-density lipoproteins (HDL) and triglycerides were assessed between matched children with and without ADHD. In addition, subgroups with versus without methylphenidate use were compared at both time points. At baseline before matching, there were no significant differences for lipid parameters between participants in the ADHD group (n = 1,219) and the control group (n = 9,741): total cholesterol (Exp(ß) = 0.999, 95%-CI 0.911-1.094, p = .979), LDL (Exp(ß) = 0.967, 95%-CI 0.872-1.071, p = .525), HDL (Exp(ß) = 1.095, 95%-CI 0.899-1.331, p = .366) and triglycerides (Exp(ß) = 1.038, 95%-CI 0.948-1.133, p = .412). Propensity score matching confirmed the non-significant differences between the ADHD and non-ADHD group at baseline. At the 10-year follow-up, n = 571 participants fulfilled complete inclusion criteria, among them 268 subjects were classified as ADHD. The two groups did not significantly differ in lipid fractions, neither cross-sectionally nor with regard to long-term changes. There was also no significant difference between methylphenidate subgroups. In this sample of children and adolescents we could not reveal any significant associations between serum lipid fractions and the diagnosis of ADHD, neither cross-sectionally nor longitudinally; even when methylphenidate use was considered. Thus, further studies using larger sample sizes are required to investigate putative long-term changes in serum lipid fractions related to ADHD.

Comparison of treatment outcomes of 360° intraoperative laser retinopexy and focal laser retinopexy with pars plans vitrectomy in patients with primary rhegmatogenous retinal detachment.

BACKGROUND: This study was to compare the outcomes of 360° intra-operative laser retinopexy (ILR) and focal laser retinopexy in treating patients with pars plans vitrectomy (PPV) for primary rhegmatogenous retinal detachment (RRD). To identify other potential risk factors for retinal re-detachment after primary PPV. METHODS: This was a retrospective cohort study. Three hundred and forty-four consecutive cases of primary rhegmatogenous retinal detachment treated with PPV were included between July 2013 and July 2018. Clinical characteristics and surgical outcomes were compared between focal laser retinopexy and additional 360° intra-operative laser retinopexy groups. Both univariate and multiple variable analysis were used to identify potential risk factors for retinal re-detachment. RESULTS: Median follow-up was 6.2 months (Q1, Q3:2.0, 17.2). As estimated with survival analysis, the 360º ILR group had the incidence of 9.74% and focal laser 19.54% at 6 months postoperatively. At 12 months postoperatively the difference was 10.78% vs. 25.21%. The difference in survival rates was significant (p = 0.0021). In multivariate Cox regression, the risk factors for retinal re-detachment were without additional 360° ILR, diabetes and macula off before the primary surgery (relatively OR = 0.456, 95%-CI [0.245-0.848], p < 0.05; OR = 2.301, 95% CI [1.130-4.687], p < 0.05; OR = 2.243, 95% CI [1.212-4.149], p < 0.05). CONCLUSION: Additional 360° ILR group had a significantly lower rate of retinal re-detachment when compared with focal laser retinopexy group. Our study also elucidated that diabetes and macular off before the primary surgery might also be the potential risk factors for higher rate of retinal re-detachment outcome. TRIAL REGISTRATION: This was a retrospective cohort study.

Pravastatin Improves Colonic and Hepatic Microcirculatory Oxygenation during Sepsis without Affecting Mitochondrial Function and ROS Production in Rats.

Microcirculatory and mitochondrial dysfunction are considered the main mechanisms of septic shock. Studies suggest that statins modulate inflammatory response, microcirculation, and mitochondrial function, possibly through their action on peroxisome proliferator-activated receptor alpha (PPAR-α). The aim of this study was to examine the effects of pravastatin on microcirculation and mitochondrial function in the liver and colon and the role of PPAR-α under septic conditions. This study was performed with the approval of the local animal care and use committee. Forty Wistar rats were randomly divided into 4 groups: sepsis (colon ascendens stent peritonitis, CASP) without treatment as control, sepsis + pravastatin, sepsis + PPAR-α-blocker GW6471, and sepsis + pravastatin + GW6471. Pravastatin (200 µg/kg s.c.) and GW6471 (1 mg/kg) were applied 18 h before CASP-operation. 24 h after initial surgery, a relaparotomy was performed, followed by a 90 min observation period for assessment of microcirculatory oxygenation (µHbO2) of the liver and colon. At the end of the experiments, animals were euthanized, and the colon and liver were harvested. Mitochondrial function was measured in tissue homogenates using oximetry. The ADP/O ratio and respiratory control index (RCI) for complexes I and II were calculated. Reactive oxygen species (ROS) production was assessed using the malondialdehyde (MDA)-Assay. Statistics: two-way analysis of variance (ANOVA) + Tukey's/Dunnett's post hoc test for microcirculatory data, Kruskal-Wallis test + Dunn's post hoc test for all other data. In control septic animals µHbO2 in liver and colon deteriorated over time (µHbO2: -9.8 ± 7.5%* and -7.6 ± 3.3%* vs. baseline, respectively), whereas after pravastatin and pravastatin + GW6471 treatment µHbO2 remained constant (liver: µHbO2 pravastatin: -4.21 ± 11.7%, pravastatin + GW6471: -0.08 ± 10.3%; colon: µHbO2 pravastatin: -0.13 ± 7.6%, pravastatin + GW6471: -3.00 ± 11.24%). In both organs, RCI and ADP/O were similar across all groups. The MDA concentration remained unchanged in all groups. Therefore, we conclude that under septic conditions pravastatin improves microcirculation in the colon and liver, and this seems independent of PPAR-α and without affecting mitochondrial function.

Gemfibrozil Improves Microcirculatory Oxygenation of Colon and Liver without Affecting Mitochondrial Function in a Model of Abdominal Sepsis in Rats.

Recent studies observed, despite an anti-hyperlipidaemic effect, a positive impact of fibrates on septic conditions. This study evaluates the effects of gemfibrozil on microcirculatory variables, mitochondrial function, and lipid peroxidation levels with regard to its potential role as an indicator for oxidative stress in the colon and liver under control and septic conditions and dependencies on PPARα-mediated mechanisms of action. With the approval of the local ethics committee, 120 Wistar rats were randomly divided into 12 groups. Sham and septic animals were treated with a vehicle, gemfibrozil (30 and 100 mg/kg BW), GW 6471 (1 mg/kg BW, PPARα inhibitor), or a combination of both drugs. Sepsis was induced via the colon ascendens stent peritonitis (CASP) model. Then, 24 h post sham or CASP surgery, a re-laparotomy was performed. Measures of vital parameters (heart rate (HR), mean arterial pressure (MAP), and microcirculation (µHbO2)) were recorded for 90 min. Mitochondrial respirometry and assessment of lipid peroxidation via a malondialdehyde (MDA) assay were performed on colon and liver tissues. In the untreated sham animals, microcirculation remained stable, while pre-treatment with gemfibrozil showed significant decreases in the microcirculatory oxygenation of the colon. In the CASP animals, µHbO2 levels in the colon and the liver were significantly decreased 90 min after laparotomy. Pre-treatment with gemfibrozil prevented the microcirculatory aberrations in both organs. Gemfibrozil did not affect mitochondrial function and lipid peroxidation levels in the sham or CASP animals. Gemfibrozil treatment influences microcirculation depending on the underlying condition. Gemfibrozil prevents sepsis-induced microcirculatory aberrances in the colon and liver PPARα-independently. In non-septic animals, gemfibrozil impairs the microcirculatory variables in the colon without affecting those in the liver.

On the Edge of the Known: Extremely Electron-Rich (Di)Carboranyl Phosphines.

The syntheses of the first B9-connected carboranylphosphines (B9-Phos) featuring two carboranyl moieties as well as access to B9-Phos ligands with bulky electron-donating substituents, previously deemed unattainable, is reported. The electrochemical properties of the B9-Phos ligands were investigated, revealing the ability of the mesityl derivatives to form stabilized phosphoniumyl radical cations. The B9-Phos ligands display an extremely electron-releasing character surpassing that of alkyl phosphines and commonly used N-heterocyclic carbenes. This is demonstrated by their very small Tolman electronic parameters (TEPs) as well as extremely low P-Se coupling constants. Cone angles and buried volumes attest to the high steric demand exerted by the (di)carboranyl phosphines. The dicarboranyl phosphine AuI complexes show superior catalytic performance in the hydroamination of alkynes compared to the monocarboranyl phosphine analogs.

Exploring the Reactivity of B-Connected Carboranylphosphines in Frustrated Lewis Pair Chemistry: A New Frame for a Classic System.

The primary phosphines MesPH2 and tBuPH2 react with 9-iodo-m-carborane yielding B9-connected secondary carboranylphosphines 1,7-H2 C2 B10 H9 -9-PHR (R=2,4,6-Me3 C6 H2 (Mes; 1 a), tBu (1 b)). Addition of tris(pentafluorophenyl)borane (BCF) to 1 a, b resulted in the zwitterionic compounds 1,7-H2 C2 B10 H9 -9-PHR(p-C6 F4 )BF(C6 F5 )2 (2 a, b) through nucleophilic para substitution of a C6 F5 ring followed by fluoride transfer to boron. Further reaction with Me2 SiHCl prompted a H-F exchange yielding the zwitterionic compounds 1,7-H2 C2 B10 H9 -9-PHR(p-C6 F4 )BH(C6 F5 )2 (3 a, b). The reaction of 2 a, b with one equivalent of R'MgBr (R'=Me, Ph) gave the extremely water-sensitive frustrated Lewis pairs 1,7-H2 C2 B10 H9 -9-PR(p-C6 F4 )B(C6 F5 )2 (4 a, b). Hydrolysis of the B-C6 F4 bond in 4 a, b gave the first tertiary B-carboranyl phosphines with three distinct substituents, 1,7-H2 C2 B10 H9 -9-PR(p-C6 F4 H) (5 a, b). Deprotonation of the zwitterionic compounds 2 a, b and 3 a, b formed anionic phosphines [1,7-H2 C2 B10 H9 -9-PR(p-C6 F4 )BX(C6 F5 )2 ]- [DMSOH]+ (R=Mes, X=F (6 a), R=tBu, X=F (6 b); R=Mes, X=H (7 a), R=tBu, X=H (7 b)). Reaction of 2 a, b with an excess of Grignard reagents resulted in the addition of R' at the boron atom yielding the anions [1,7-H2 C2 B10 H9 -9-PR(p-C6 F4 )BR'(C6 F5 )2 ]- (R=Mes, R'=Me (8 a), R=tBu, R'=Me (8 b); R=Mes, R'=Ph (9 a), R=tBu, R'=Ph (9 b)) with [MgBr(Et2 O)n ]+ as counterion. The ability of the zwitterionic compounds 3 a, b to hydrogenate imines as well as the Brønsted acidity of 3 a were investigated.

Electroconvulsive Therapy in Children and Adolescents in Germany-A Case Series From 3 University Hospitals.

OBJECTIVE: Electroconvulsive therapy (ECT) is a well-established, safe, and efficacious treatment for severe psychiatric disorders. In children and adolescents, it is used much less frequently than in adults, likely because of a lack of knowledge. METHODS: We retrospectively analyzed all patients aged 12 to 17 years who completed a course of ECT at 3 psychiatric university hospitals in Germany between 2010 and 2020. Clinical Global Impression Severity (CGI-S) scores were assessed based on electronic medical records. Changes in CGI-S scores were assessed using a paired samples t test. Predictors for response and remission were assessed using binomial logistic regression. RESULTS: We included 32 patients. The CGI-S scores improved significantly from before to after ECT treatment (6.9 vs 3.9, t = 10.0, P < 0.01). A total of 40.6% of patients responded (CGI ≤ 3) and 21.9% remitted (CGI ≤ 2). The number of ineffective medication trials in the 6 months before ECT treatment was significantly associated with response (odds ratio, 0.54; P = 0.028) and remission (odds ratio, 0.31; P = 0.048). Five patients reported subjective cognitive adverse effects, 2 patients exhibited a prolonged seizure, 1 patient reported headaches, and 1 patient experienced a mild allergic reaction after anesthesia with etomidate. A total of 65.6% of patients experienced no adverse effects at all. CONCLUSIONS: This retrospective analysis found ECT to be effective and safe in children and adolescents irrespective of their main diagnosis. The reported data point to the importance of an early use of ECT for severe psychiatric diseases in child and adolescent psychiatry.

A Comparison of Partial Information Decompositions Using Data from Real and Simulated Layer 5b Pyramidal Cells.

Partial information decomposition allows the joint mutual information between an output and a set of inputs to be divided into components that are synergistic or shared or unique to each input. We consider five different decompositions and compare their results using data from layer 5b pyramidal cells in two different studies. The first study was on the amplification of somatic action potential output by apical dendritic input and its regulation by dendritic inhibition. We find that two of the decompositions produce much larger estimates of synergy and shared information than the others, as well as large levels of unique misinformation. When within-neuron differences in the components are examined, the five methods produce more similar results for all but the shared information component, for which two methods produce a different statistical conclusion from the others. There are some differences in the expression of unique information asymmetry among the methods. It is significantly larger, on average, under dendritic inhibition. Three of the methods support a previous conclusion that apical amplification is reduced by dendritic inhibition. The second study used a detailed compartmental model to produce action potentials for many combinations of the numbers of basal and apical synaptic inputs. Decompositions of the entire data set produce similar differences to those in the first study. Two analyses of decompositions are conducted on subsets of the data. In the first, the decompositions reveal a bifurcation in unique information asymmetry. For three of the methods, this suggests that apical drive switches to basal drive as the strength of the basal input increases, while the other two show changing mixtures of information and misinformation. Decompositions produced using the second set of subsets show that all five decompositions provide support for properties of cooperative context-sensitivity-to varying extents.

Enhanced Dendritic Inhibition and Impaired NMDAR Activation in a Mouse Model of Down Syndrome.

Down syndrome (DS) or Trisomy 21 is a developmental disorder leading to cognitive deficits, including disruption of hippocampus-dependent learning and memory. Enhanced inhibition has been suggested to underlie these deficits in DS based on studies using the Ts65Dn mouse model. Here we show that, in this mouse model, GABAergic synaptic inhibition onto dendrites of hippocampal pyramidal cells is increased. By contrast, somatic inhibition was not altered. In addition, synaptic NMDAR currents were reduced. Furthermore, dendritic inhibition was mediated via nonlinear α5-subunit containing GABAARs that closely matched the kinetics and voltage dependence of NMDARs. Thus, enhanced dendritic inhibition and reduced NMDA currents strongly decreased burst-induced NMDAR-mediated depolarization and impaired LTP induction. Finally, selective reduction of α5-GABAAR-mediated inhibition rescued both burst-induced synaptic NMDAR activation and synaptic plasticity. These results demonstrate that reduced synaptic NMDAR activation and synaptic plasticity in the Ts65Dn mouse model of DS can be corrected by specifically targeting nonlinear dendritic inhibition.SIGNIFICANCE STATEMENT Mild to moderate intellectual disability is a prominent feature of Down syndrome. Previous studies in mouse models suggest that increased synaptic inhibition is a main factor for decreased synaptic plasticity, the cellular phenomenon underlying memory. The present study shows that increased inhibition specifically onto dendrites together with reduced NMDAR content in excitatory synapses may be the cause. Reducing a slow nonlinear component that is specific to dendritic inhibitory inputs and mediated by α5 subunit-containing GABAA receptors rescues both NMDAR activation and synaptic plasticity.

Exogenous vasopressin dose-dependently modulates gastric microcirculatory oxygenation in dogs via V1A receptor.

BACKGROUND: Hypercapnia improves gastric microcirculatory oxygenation (µHbO2) and increases vasopressin plasma levels, whereas V1A receptor blockade abolishes the increase of µHbO2. The aim of this study was to evaluate the effect of exogenous vasopressin (AVP) in increasing doses on microcirculatory perfusion and oxygenation and systemic hemodynamic variables. Furthermore, we evaluated the role of the vasopressin V1A receptor in mediating the effects. METHODS: In repetitive experiments, six anesthetized dogs received a selective vasopressin V1A receptor inhibitor ([Pmp1, Tyr (Me)2]-Arg8-Vasopressin) or sodium chloride (control groups). Thereafter, a continuous infusion of AVP was started with dose escalation every 30 min (0.001 ng/kg/min-1 ng/kg/min). Microcirculatory variables of the oral and gastric mucosa were measured with reflectance spectrometry, laser Doppler flowmetry, and incident dark field imaging. Transpulmonary thermodilution was used to measure systemic hemodynamic variables. AVP plasma concentrations were measured during baseline conditions and 30 min after each dose escalation. RESULTS: During control conditions, gastric µHbO2 did not change during the course of experiments. Infusion of 0.001 ng/kg/min and 0.01 ng/kg/min AVP increased gastric µHbO2 to 87 ± 4% and 87 ± 6%, respectively, compared to baseline values (80 ± 7%), whereas application of 1 ng/kg/min AVP strongly reduced gastric µHbO2 (59 ± 16%). V1A receptor blockade prior to AVP treatment abolished these effects on µHbO2. AVP dose-dependently enhanced systemic vascular resistance (SVR) and decreased cardiac output (CO). After prior V1A receptor blockade, SVR was reduced and CO increased (0.1 ng/kg/min + 1 ng/kg/min AVP). CONCLUSIONS: Exogenous AVP dose-dependently modulates gastric µHbO2, with an increased µHbO2 with ultra-low dose AVP. The effects of AVP on µHbO2 are abolished by V1A receptor inhibition. These effects are independent of a modulation of systemic hemodynamic variables.

Sequence-Specific Self-Assembly of Positive and Negative Monomers with Cucurbit[8]uril Linkers.

The self-assembly into dynamic oligomers of Cucurbit[8]uril (CB[8]), a positive ditopic Ir(III) bis-terpyridine complex, and a negative ditopic Fe(II) bis-terpyridine complex flanked by four butyrate side chains was assessed to answer a seemingly straightforward question: does CB[8] adopt a social self-sorting pattern by encapsulating both positive and negative units into a heteroternary complex? We showed that this is indeed the case, with CB[8] linking a positive Ir unit to a neighboring negative Fe unit whenever possible. Furthermore, the solubility of the dynamic oligomers was significantly affected by their sequence; upon addition of 0.6-1.2 equiv of positive Ir oligomer to its negative Fe counterpart, the predominant assembly present in solution was a mixed oligomer with a (Fe-Ir-Ir-) n sequence. Weak interactions between the negative butyrate side chains and the partially positive outer wall of CB[7] were also identified by two-dimensional nuclear magnetic resonance techniques, and resulted in a negative p Ka shift (0.10 p Ka unit) for the terminal carboxylic groups.

COMP-assisted collagen secretion--a novel intracellular function required for fibrosis.

Cartilage oligomeric matrix protein (COMP) is an abundant component in the extracellular matrix (ECM) of load-bearing tissues such as tendons and cartilage. It provides adaptor functions by bridging different ECM structures. We have previously shown that COMP is also a constitutive component of healthy human skin and is strongly induced in fibrosis. It binds directly and with high affinity to collagen I and to collagen XII that decorates the surface of collagen I fibrils. We demonstrate here that lack of COMP-collagen interaction in the extracellular space leads to changes in collagen fibril morphology and density, resulting in altered skin biomechanical properties. Surprisingly, COMP also fulfills an important intracellular function in assisting efficient secretion of collagens, which were retained in the endoplasmic reticulum of COMP-null fibroblasts. Accordingly, COMP-null mice showed severely attenuated fibrotic responses in skin. Collagen secretion was fully restored by introducing wild-type COMP. Hence, our work unravels a new, non-structural and intracellular function of the ECM protein COMP in controlling collagen secretion.

12-Vertex Zwitterionic Bis-phosphonium-nido-carborates through Ring-Opening Reactions of 1,2-Diphosphetanes.

Carborane-substituted 1,2-diphosphetanes (Ia,b) react with elemental lithium in THF with cleavage of the P-P bond to give a deep red solution from which, in the case of Ia, red crystals of a lithiated intermediate, [{1-Li(THF)PtBu-6-PtBu-4,1,6-closo-Li(THF)C2 B10 H10 }{Li(THF)3 }]2 ⋅2 THF (2 a), are obtained. The compound is dimeric, C2 -symmetric and contains six lithium and four phosphorus atoms. Two lithium atoms cap the six-membered C2 B4 faces, resulting in two 13-vertex closo-clusters (according to Wade's rules) with docosahedral geometry. The addition of methyl iodide resulted in the formation of zwitterionic bis-phosphonium-nido-carborates 7,10-bis(tert-butyldimethylphosphonium)dodecahydro-7,10-dicarba-nido-dodecaborate(2-) (1 a) and 7,10-bis(N,N-diisopropylaminodimethylphosphonium)dodecahydro-7,10-dicarba-nido-dodecaborate(2-) (1 b) in moderate to good yields. Compounds 1 a and 1 b exhibit short Ccluster -P bonds and large Ccluster ⋅⋅⋅Ccluster distances in the solid state. Further insight into the ring opening and reduction potential of the alkyl halide was obtained from methylation reactions of different 1,2-bis-phosphinocarboranes. The reaction of rac-/meso-1,2-bis(tert-butylmethylphosphino)-1,2-dicarba-closo-dodecaborane(12) (3 a) with two equivalents of methyl iodide also resulted in the formation of 1 a (as shown by NMR spectroscopy), whereas the reaction of 1,2-bis(diphenylphosphino)-1,2-dicarba-closo-dodecaborane(12) with methyl triflate afforded the phosphonium salt 1-methyl-diphenylphosphonium-2-diphenylphosphino-1,2-dicarba-closo-dodecaborane(12) triflate (4) without reduction of the cluster.

Stabilization of integrin-linked kinase by the Hsp90-CHIP axis impacts cellular force generation, migration and the fibrotic response.

Integrin-linked kinase (ILK) is an adaptor protein required to establish and maintain the connection between integrins and the actin cytoskeleton. This linkage is essential for generating force between the extracellular matrix (ECM) and the cell during migration and matrix remodelling. The mechanisms by which ILK stability and turnover are regulated are unknown. Here we report that the E3 ligase CHIP-heat shock protein 90 (Hsp90) axis regulates ILK turnover in fibroblasts. The chaperone Hsp90 stabilizes ILK and facilitates the interaction of ILK with α-parvin. When Hsp90 activity is blocked, ILK is ubiquitinated by CHIP and degraded by the proteasome, resulting in impaired fibroblast migration and a dramatic reduction in the fibrotic response to bleomycin in mice. Together, our results uncover how Hsp90 regulates ILK stability and identify a potential therapeutic strategy to alleviate fibrotic diseases.

Role of Integrins α1ß1 and α2ß1 in Wound and Tumor Angiogenesis in Mice.

Integrins are transmembrane receptors composed of one α subunit and one ß subunit and are involved in cellular growth, differentiation, and apoptosis. The collagen-binding integrins α1ß1 and α2ß1 have been shown to regulate wound and tumor vascularization by different mechanisms. In this study, we assessed wound and tumor vascularization in mice with genetic ablation of both integrin subunits α1 and α2, which resulted in loss of integrins α1ß1 and α2ß1. Wound angiogenesis was investigated in excisional wounds that were inflicted on the back skin of control and mice lacking integrin α1ß1 and α2ß1. Mutant mice displayed reduced wound angiogenesis, which correlated with decreased macrophage numbers at 3 and 7 days after injury, and showed significantly attenuated vascularization of sponge implants. Angiogenesis induced by tumors arising from intradermal injection of B16 F1 melanoma cells was also reduced in comparison to controls 7 days after injection. This reduction in angiogenesis correlated with increased levels and activity of circulating matrix metalloproteinase 9 and elevated angiostatin levels in plasma of mutant mice, which reduced endothelial cell proliferation. Ex vivo mutant aortic ring explants developed significantly fewer and thinner aortic sprouts with fewer branch points than controls because of impaired endothelial cell proliferation. In conclusion, the loss of integrins α1ß1 and α2ß1 in mice results in reduced wound and tumor angiogenesis by cell-autonomous and extrinsic mechanisms.

Effect of Topical Iloprost and Nitroglycerin on Gastric Microcirculation and Barrier Function during Hemorrhagic Shock in Dogs.

BACKGROUND: Topical drug application is used to avoid systemic side effects. The aim of this study was to analyze whether locally applied iloprost or nitroglycerin influence gastric mucosal perfusion, oxygenation, and barrier function during physiological and hemorrhagic conditions. METHODS: In repeated experiments, 5 anesthetized dogs received iloprost, nitroglycerin, or normal saline during physiological and hemorrhagic (-20% blood volume) conditions. Macro- and microcirculatory variables were recorded continuously. Gastric barrier function was assessed via translocation of sucrose into the blood. RESULTS: During hemorrhage, gastric mucosal oxygenation decreased from 77 ± 4 to 37 ± 7%. This effect was attenuated by nitroglycerin (78 ± 6 to 47 ± 13%) and iloprost (82 ± 4 to 54 ± 9%). Sucrose plasma levels increased during hemorrhage from 7 ± 4 to 55 ± 15 relative amounts. This was alleviated by nitroglycerin (5 ± 8 to 29 ± 38 relative amounts). These effects were independent of systemic hemodynamic variables. CONCLUSIONS: During hemorrhage, topical nitroglycerin and iloprost improve regional gastric oxygenation without affecting perfusion. Nitroglycerin attenuated the shock-induced impairment of the mucosal barrier integrity. Thus, local drug application improves gastric microcirculation without compromising systemic hemodynamic variables, and it may also protect mucosal barrier function.

C2-Symmetric P,N Ligands Derived from Carborane-Based Diphosphetanes: Synthesis and Coordination Chemistry.

Racemic carborane-based bisphosphanes were obtained by dismutation reactions between a carborane-based diphosphetane and diaryl dichalogenides. NMR spectroscopic and theoretical studies revealed a two-step mechanism explaining the high stereoselectivity of these reactions. The coordination chemistry of the multidentate P,N ligands 6c and 6d in copper(I) and silver(I) complexes was studied. While 6d acted exclusively as tetradentate ligand, 6c showed either tridentate or tetradentate coordination depending on the metal and the counterion.

Vasopressin V1A receptors mediate the stabilization of intestinal mucosal oxygenation during hypercapnia in septic rats.

BACKGROUND: Microvascular oxygen saturation (µHBO2) plays an essential role in the development and outcome of sepsis. Hypercapnia (HC) improves the microvascular oxygenation of the mucosa in both healthy and septic animals. Vasopressin V1A receptor blockade prevents this positive effect under otherwise physiological conditions. The aim of this study was to investigate the effects and mechanisms of the vasopressin system during hypercapnia under septic conditions. METHODS: 80 rats were randomized into 8 groups (N=10). Colon ascendens stent peritonitis (CASP) or sham surgery was performed on 40 animals each to establish a moderate polymicrobial sepsis or sham control, respectively. 24h after sepsis induction the animals were subjected to 120min of volume-controlled and pressure-limited ventilation with either normocapnic (pCO2 35-45mmHg) or moderate hypercapnic (pCO2 of 65-75mmHg) ventilation targets. Animals received either vasopressin V1A receptor blockade (SR 49059, 1mgkg(-1) i.v.) or vehicle solution (dimethyl sulfoxide, 1%). Blood pressure, heart rate, pO2 and pCO2 were measured and microcirculatory oxygenation (µHBO2) and microcirculatory flow (µflow) were recorded using tissue reflectance spectrophotometry. Oxygen supply (µDO2) and consumption (µVO2) were calculated from intermittent blood gas analysis. RESULTS: In septic animals, µHBO2 declined during normocapnia (-11±10.3) but remained unchanged during hypercapnia. µHBO2 declined with vasopressin V1A receptor blockade both during normocapnia (-7.4±10.6) and hypercapnia (-9.2±9.8). Microcirculatory oxygen consumption was significantly reduced by hypercapnia in septic animals (-2.4·10(5) [AU]±2.4·10(5) [AU]). In sham animals, µHBO2 and µVO2 did not change. CONCLUSION: Vasopressin V1A receptors mediate the beneficial effects of hypercapnia on microcirculatory oxygenation during sepsis. The effects of vasopressin on µHBO2 might be related to decreased oxygen consumption during hypercapnia.

Interlaboratory study on differential analysis of protein glycosylation by mass spectrometry: the ABRF glycoprotein research multi-institutional study 2012.

One of the principal goals of glycoprotein research is to correlate glycan structure and function. Such correlation is necessary in order for one to understand the mechanisms whereby glycoprotein structure elaborates the functions of myriad proteins. The accurate comparison of glycoforms and quantification of glycosites are essential steps in this direction. Mass spectrometry has emerged as a powerful analytical technique in the field of glycoprotein characterization. Its sensitivity, high dynamic range, and mass accuracy provide both quantitative and sequence/structural information. As part of the 2012 ABRF Glycoprotein Research Group study, we explored the use of mass spectrometry and ancillary methodologies to characterize the glycoforms of two sources of human prostate specific antigen (PSA). PSA is used as a tumor marker for prostate cancer, with increasing blood levels used to distinguish between normal and cancer states. The glycans on PSA are believed to be biantennary N-linked, and it has been observed that prostate cancer tissues and cell lines contain more antennae than their benign counterparts. Thus, the ability to quantify differences in glycosylation associated with cancer has the potential to positively impact the use of PSA as a biomarker. We studied standard peptide-based proteomics/glycomics methodologies, including LC-MS/MS for peptide/glycopeptide sequencing and label-free approaches for differential quantification. We performed an interlaboratory study to determine the ability of different laboratories to correctly characterize the differences between glycoforms from two different sources using mass spectrometry methods. We used clustering analysis and ancillary statistical data treatment on the data sets submitted by participating laboratories to obtain a consensus of the glycoforms and abundances. The results demonstrate the relative strengths and weaknesses of top-down glycoproteomics, bottom-up glycoproteomics, and glycomics methods.