Eye position compensation improves estimates of response magnitude and receptive field geometry in alert monkeys

Studies of visual function in behaving subjects require that stimuli be positioned reliably on the retina in the presence of eye movements. Fixational eye movements scatter stimuli about the retina, inflating estimates of receptive field dimensions, reducing estimates of peak responses, and blurring maps of receptive field subregions. Scleral search coils are frequently used to measure eye position, but their utility for correcting the effects of fixational eye movements on receptive field maps has been questioned. Using eye coils sutured to the sclera and preamplifiers configured to minimize cable artifacts, we reexamined this issue in two rhesus monkeys. During repeated fixation trials, the eye position signal was used to adjust the stimulus position, compensating for eye movements and correcting the stimulus position to place it at the desired location on the retina. Estimates of response magnitudes and receptive field characteristics in V1 and in LGN were obtained in both compensated and uncompensated conditions. Receptive fields were narrower, with steeper borders, and response amplitudes were higher when eye movement compensation was used. In sum, compensating for eye movements facilitated more precise definition of the receptive field. We also monitored horizontal vergence over long sequences of fixation trials and found the variability to be low, as expected for this precise behavior. Our results imply that eye coil signals can be highly accurate and useful for optimizing visual physiology when rigorous precautions are observed.     

Poor outcomes among elderly patients hospitalized for influenza-like illness

Background and objective: Global Influenza Hospital Surveillance Network is a worldwide initiative that aims to document the burden of influenza infections among acute admissions and vaccine effectiveness in particular countries. As a partner of this platform, we aimed to determine the frequency of influenza infections among acute admissions with influenza-like illness and the outcomes of enrolled patients during the 2015–2016 influenza season in selected hospitals in Turkey.

Patients and methods: The investigators screened the hospital admission registries, chart review or available records, and screened all patients hospitalized in the previous 24–48?hours or overnight in the predefined wards or emergency room. A total of 1351 patients were screened for enrollment in five tertiary care referral hospitals in Ankara and 774 patients (57.3% of the initial screened population) were eligible for swabbing. All of the eligible patients who consented were swabbed and tested for influenza with real-time polymerase chain reaction (PCR) based methods.

Results: Overall, influenza positivity was detected in 142 patients (18.4%). The predominant influenza strain was A H1N1pdm09. Outcomes were worse among elderly patients, regardless of the presence of the influenza virus. Half of the patients over 65 years of age were admitted to the intensive care unit, while one third required any mode of mechanical ventilation and one fourth died in the hospital in that particular episode.

Conclusion: These findings can guide hospitals to plan and prepare for the influenza season. Effective influenza vaccination strategies, particularly aimed at the elderly and adults with chronic diseases, can provide an opportunity for prevention of deaths due to influenza-like illness.     

Neurotoxic effects of lambda‐cyhalothrin modulated by piperonyl butoxide in the brain of Oreochromis niloticus

The objective of this research was to investigate the neurotoxic effects of pyrethroid pesticide lambda‐cyhalothrin by the modulation of cytochrome P450 with piperonyl butoxide in the brain of juvenile Oreochromis niloticus. The fish were exposed to 0.48 μg L^?1 (1/6 of the 96‐h LC₅₀) lambda‐cyhalothrin and 10 μg L^?1 piperonyl butoxide for 96 h and 15 days. tGSH, GSSG, TBARS contents, GPx, GR, GST, and AChE enzymes activities were determined by spectrophotometrical methods and Hsp70 content was analyzed by ELISA technique. Lambda‐cyhalothrin had no significant effect on the components of GSH redox system, lipid peroxidation and Hsp70 levels but inhibited AChE activity. In the presence of piperonyl butoxide, lambda‐cyhalothrin caused increases in tGSH, GSSG, TBARS and Hsp70 contents, GST activity, and decrease in AChE activity. Present results showed that in the presence of piperonyl butoxide, lambda‐cyhalothrin caused neurotoxic effects by increasing oxidative stress. Adaptation to its oxidative stress effects may be supplied by GSH‐related antioxidant system. Piperonyl butoxide revealed neurotoxic effect of lambda‐cyhalothrin. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1275–1282, 2014.     

Organic insecticide spinosad causes in vivo oxidative effects in the brain of Oreochromis niloticus

Spinosad is an organic insecticide derived from a naturally occurring soil bacterium and is used in organic farming worldwide. The aim of this study was to evaluate in vivo toxic effects of spinosad in the brain of Oreochromis niloticus as a model organism. The fish were exposed to sublethal spinosad concentrations (25, 50, 75 mg L^?1) for 24–48–72 h to determine tGSH, GSH, GSSG, and TBARS contents, GSH/GSSG ratio, and GPx, GR, GST enzymes activities using spectrophotometrical methods, and Hsp70 content by an ELISA technique. Spinosad caused elevations in the contents of tGSH, GSH, GSSG, Hsp70, and reductions in the ratio of GSH/GSSG and GPx activity and an induction in the GR activity. The results indicated that spinosad had oxidative effects in the brain tissue by altering the parameters in GSH‐related antioxidant system and Hsp70. It was also suggested that spinosad‐induced free‐radicals were eliminated by GSH‐related antioxidant system in the brain of Oreochromis niloticus. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 253–260, 2014.     

Kompartmentsyndrom nach paravasaler Applikation von Röntgenkontrastmittel

The incidence of extravasation of contrast medium is reported in the literature to be between 0.2?% and 0.9 %. A rare consequence of this could be compartment syndrome of the affected limb which requires immediate treatment. We report the case of a patient who developed acute compartment syndrome of the forearm after intravenous injection of radiographic contrast medium in a radiovolar vein during a computed tomography (CT) scan for multiple trauma. The clinical symptoms with pain, loss of range of motion and sensitivity functions, measurement of compartment pressure and radiological images confirmed the diagnosis. After emergency dermatofasciotomy of the forearm the full range of motion and sensitivity functions could be restored.     

Modification of Serum Galectin-3 and Reversal of Cardiac Remodeling Following Pediatric Transcatheter Atrial Septal Defect Closure

Objectives: We aimed to evaluate the effect of percutaneous atrial septal defect (ASD) closure in children using right heart indices and serum galectin-3 (Gal-3), as potential biomarkers of right heart remodeling. Methods: This case–control prospective study included 40 children with ASD and 25 control subjects. An echocardiographic evaluation was performed before the procedure, as well as 24 h, 1 month, and 6 months after intervention. Serum Gal-3 was measured before, and 1 month after the procedure. Results: Serum Gal-3 concentration, right atrial (RA) dimensions, right ventricular (RV) dimensions, indexed RA area, and right index of myocardial performance (RIMP) were significantly increased in children with ASD compared with control subjects while tricuspid annular plane systolic excursion (TAPSE) was significantly decreased. Six months after closure, RA, and RV dimensions significantly decreased and RV function improved (RIMP decreased and TAPSE increased). Gal-3 oncentration significantly decreased 1 month after ASD closure, but it did not reach normal range compared with control subjects. A positive correlation between Gal-3 and age at closure, RA area, RV dimensions, and RIMP was observed. A positive correlation was observed between the decrease in Gal-3 concentration and the decrease in RA area and RV dimensions 1 month after ASD closure. A significant negative correlation was observed between TAPSE and Gal-3 concentration before and after intervention. Conclusions: Percutaneous ASD closure can improve right-sided indices and decrease serum Gal-3 concentration. Gal-3 can be used as a sensitive biomarker of right heart remodeling, with a decrease in Gal-3 concentration suggesting reversal of maladaptive remodeling.     

An inactive receptor-G protein complex maintains the dynamic range of agonist-induced signaling

Agonist binding promotes activation of G protein-coupled receptors (GPCRs) and association of active receptors with G protein heterotrimers. The resulting active-state ternary complex is the basis for conventional stimulus-response coupling. Although GPCRs can also associate with G proteins before agonist binding, the impact of such preassociated complexes on agonist-induced signaling is poorly understood. Here we show that preassociation of 5-HT₇ serotonin receptors with G_s heterotrimers is necessary for agonist-induced signaling. 5-HT₇ receptors in their inactive state associate with G_s, as these complexes are stabilized by inverse agonists and receptor mutations that favor the inactive state. Inactive-state 5-HT₇–G_s complexes dissociate in response to agonists, allowing the formation of conventional agonist–5-HT₇–G_s ternary complexes and subsequent G_s activation. Inactive-state 5-HT₇–G_s complexes are required for the full dynamic range of agonist-induced signaling, as 5-HT₇ receptors spontaneously activate G_s variants that cannot form inactive-state complexes. Therefore, agonist-induced signaling in this system involves two distinct receptor-G protein complexes, a conventional ternary complex that activates G proteins and an inverse-coupled binary complex that maintains the inactive state when agonist is not present.

G protein-coupled receptors (GPCRs) transduce a wide variety of physiological signals and are targeted by a substantial fraction of all therapeutic drugs (1). GPCRs are conformationally dynamic and transition between inactive and active states, the latter being capable of interacting with and activating heterotrimeric G proteins (2). Although some level of constitutive activity is common, the conformational equilibrium “setpoint” usually favors the inactive state of the receptor, thus keeping the system turned off and ready to respond to agonists. Agonist binding stabilizes active conformations and promotes the formation of transient active-state ternary agonist-receptor-G protein complexes (3). This positive allosteric interaction between agonist and G protein binding is the hallmark of conventional GPCR coupling. Receptor-G protein complexes that form before agonist binding have also been described (4–8) and are generally thought of as a means to promote rapid or specific signaling after agonist binding. However, the properties and functional significance of such “preassociated” complexes are largely unknown, and inactive receptor conformations are generally considered unable to interact with G proteins. Here we show that unliganded 5-HT₇ serotonin receptors form complexes with G_s heterotrimers, and that these complexes help maintain the receptor in an inactive state. Agonist binding leads to dissociation of inactive-state 5-HT₇–G_s complexes, which in turn allows increased formation of active-state 5-HT₇–G_s complexes and G protein activation. Thus, a negative allosteric interaction between agonist and G protein binding is required for the full sensitivity of these receptors to serotonin.     

One-year follow up results of Smoking Cessation Outpatient Clinic

In this study we investigated the five-year-results of our smoking cessation outpatient clinic retrospectively. Out of 839 subjects admitted to our clinic during this time period 634 of them completed the one-year follow up period. 318 (50.2%) of these subjects were male and 316 (49.8%) of them were female. Subjects were divided into two groups. While one group received nicotine patch therapy, education and motivation the other group received just education and motivation. Mean age was 43.5 +/- 12 years. Nicotine patch therapy administered to 297 subjects and smoking cessation rates in this group were 46.8% at 15th day and 33.6% at the end of first year. The other group had smoking cessation rates of 11.8% at 15th day and 10.9% at the end of one year. Out of 185 subjects who did not smoke at the end of 15th day 98 of them were also not smoking at the end of one year. 449 subjects were smoking at the end of 15th day and just 26 (5.7%) of them gave up smoking at the end of first year. Therapy compliance was 82.2% at the 15th day and 23.2% at 12th week. Most frequent side effects were local skin reactions (13.8%) due to nicotine patches, irritability and nervousness (8.5%) and concentration difficulties (7.4%). In this retrospective analysis we concluded that nicotine replacement therapy in conjunction with education and motivation may be an effective method for helping individuals in giving up smoking. We also observed that smoking situation in first 15 days is a good predictor of long-term success.     

Serum galectin-3 level in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease of unknown etiology characterized by progressive fibrosis. Activated fibroblasts are mainly responsible for fibrosis in SSc. Galectin-3, a β-galactoside-binding lectin, plays many important regulatory roles in both physiological and pathological processes including proliferation, apoptosis, inflammation, and fibrosis. The purpose of this study was to assess the serum galectin-3 levels in patients with SSc. Thirty-seven SSc patients, 23 systemic lupus erythematosus (SLE) patients (serving as patient control group), and 28 healthy volunteers were enrolled in this study. Disease activity and severity scores were detected with Valentini disease activity index and Medsger disease severity scale in the SSc group and SLE disease activity index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index in the SLE group. The serum levels of galectin-3, vascular endothelial growth factor, transforming growth factor-β, and interleukin-6 were determined. Compared to the control group, the galectin-3 levels were higher in the SSc and SLE groups. The galectin-3 levels were not correlated with the disease activity and severity indexes in both patient groups. But, the serum galectin-3 levels were higher in the active SSc and SLE subgroups than in the inactive SSc (4.6?±?5.8 vs. 1.3?±?1.1 ng/ml, p?=?0.015) and SLE (17.4?±?11.3 vs. 6.5?±?8.9 ng/ml, p?=?0.019) subgroups. These results suggest that galectin-3, which is associated with fibrosis and inflammation by previous studies, may be a prominent biomarker of disease activity in SSc.