1000 resultados para sensitivity map


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PURPOSE: To determine whether implantation of an aspherical intraocular lens (IOL) results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery without critical reduction of depth of focus. DESIGN: Double-blinded, randomized, prospective study. METHODS: In an intraindividual study of 25 patients with bilateral cataract, an aspherical IOL (Akreos Advanced Optic [AO]; Bausch & Lomb, Inc., Rochester, New York, USA) was implanted in one eye and a spherical IOL (Akreos Fit; Bausch & Lomb, Inc) in the fellow eye. Higher-order aberrations with a 5- and 6-mm pupil were measured with a dynamic retinoscopy aberrometer at 1 and 3 months after surgery. Uncorrected and best-corrected visual acuity and contrast sensitivity under mesopic and photopic conditions also were measured. Distance-corrected near and intermediate visual acuity were studied as a measurement of depth of focus. RESULTS: There was no statistically significant difference between eyes in uncorrected and best-corrected visual acuity at I and 3 months after surgery. There was a statistically significant between-group difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. The Akreos AO group obtained statistically significant lower values of higher-order aberrations and spherical aberration with 5- and 6-mm pupils compared with the Akreos Fit group (P < .05). There was no significant difference in distance-corrected near and intermediate visual acuity between both groups. CONCLUSIONS: Aspherical aberration-free Akreos AO IOL induced significantly less higher-order aberrations and spherical aberration than the Akreos Fit. Contrast sensitivity was better under mesopic conditions with the Akreos AO with similar results of depth of focus. (Am J Ophthalmol 2010;149:383-389. (C) 2010 by Elsevier Inc. All rights reserved.)

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Two longitudinal experiments involving Angora goats challenged with either bovine or ovine strains of Mycobacterium avium subspecies paratuberculosis (Map) have been conducted over a period of 54 and 35 months, respectively. Blood samples for the interferon-gamma (IFN-gamma) test and the absorbed ELISA and faecal samples for bacteriological culture were taken pre-challenge and monthly post-challenge. Persistent shedding, IFN-gamma production, seroconversion and clinical disease occurred earlier with the bovine Map gut mucosal tissue challenge inoculum than with cultured bacteria. The IFN-gamma responses of the gut mucosal tissue and bacterial challenge groups were substantially and consistently higher than those of the control group. The in vivo and cultured cattle strains were much more pathogenic for goats than the sheep strains with persistent faecal shedding, seroconversion and clinical disease occurring in the majority of bovine Map challenged goats. With the ovine Map, 3 goats developed persistent antibody responses but only one of these goats developed persistent faecal shedding and clinical disease. However, there was no significant difference between the IFN-gamma responses of the tissue challenged, bacterial challenged and control groups. Compared with sheep, the ELISA appeared to have higher sensitivity and the IFN-gamma test lower specificity. (C) 2005 Elsevier B.V. All rights reserved.

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Because it permits self-teaching, phonological recoding (the efficient translation of letters or letter groups into sound) is arguably the key skill acquired in learning to read an alphabetic writing system. Deficits in this skill are the most common source of children's reading difficulties. In addition, poor readers tend to perform at a lower level than good readers on a wide variety of phonological processing tasks. These findings have been widely interpreted as implying a latent phonological processing ability as a distal cause of variation in reading skill. Clearly, such an interpretation does not imply that all phonological processing skills contribute directly to the phonological recoding process. This paper outlines a series of studies conducted at the University of Queensland. This work consistently suggests that children's phonological sensitivity contributes more directly than other phonological processing abilities to the development of phonological recoding skills.

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Familial Mediterranean fever (FMF) is a recessive disorder of inflammation caused by mutations in a gene (designated MEFV) on chromosome 16p13.3, We have recently constructed a 1-Mb cosmid contig that includes the FMF critical region. Here we show genotype data for 12 markers from our physical map, including 5 newly identified microsatellites, in FMF families. Intrafamilial recombinations placed MEFV in the similar to 285 kb between D16S468/D16S3070 and D16S3376. We observed significant linkage disequilibrium in the North African Jewish population, and historical recombinants in the founder haplotype placed MEFV between D16S3082 and D16S3373 (similar to 200 kb). In smaller panels of Iraqi Jewish, Arab, and Armenian families, there were significant allelic associations only for D16S3370 and D16S2617 among the Armenians. A sizable minority of Iraqi Jewish and Armenian carrier chromosomes appeared to be derived from the North African Jewish ancestral haplotype. We observed a unique FMF haplotype common to Iraqi Jews, Arabs, and Armenians and two other haplotypes restricted to either the Iraqi Jewish or the Armenian population. These data support the view that a few major mutations account for a large percentage of the cases of FMF and suggest that same of these mutations arose before the affected Middle Eastern populations diverged from one another. (C) 1997 Academic Press.

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In this study, we evaluated the acute effects of central NAC administration on baroreflex in juvenile SHR and Wistar Kyoto (WKY) rats. Male SHR and WKY rats (8 10 weeks old) were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. After basal MAP and HR recordings, the baroreflex was tested with a pressor dose of phenylephrine (PHE, 8 mu g/kg, bolus) and a depressor dose of sodium nitroprusside (SNP, 50 mu g/kg, bolus). Baroreflex was evaluated before, 5, 15, 30 and 60 minutes after NAC injection into the 4th V. Vehicle treatment did not change baroreflex responses in WKY and SHR. Central NAC slightly but significantly increased basal HR at 15 minutes and significantly reduced PHE-induced increase in MAP 30 and 60 minutes after NAC injection (p < 0.05) in WKY rats. In relation to SHR, NAC decreased HR range 15 and 30 minutes after its administration. In conclusion, acute NAC into the 4th V does not improve baroreflex in juvenile SHR.

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Background: Selective serotonin reuptake inhibitors (SSRIs) are first-line treatments for posttraumatic stress disorder (PTSD). Serotonergic (5HT) attenuation of stress sensitivity is postulated from SSRIs` effects in other anxiety disorders, and we studied this in PTSD. Methods: Ten patients with PTSD fully recovered on SSRIs (Clinical Global Impression Scale-I 1 and 2) were enrolled in the study. Patients were tested on two occasions I week apart; in each session, they received a drink containing large neutral amino acids (LNAAs) either with (sham tryptophan depletion [STD], control) or without (acute tryptophan depletion [ATD]) tryptophan. At 5.5 hours after the drink, subjects were exposed to a trauma-related exposure challenge. Self-reports of PTSD (visual analogue scales [VAS] and the Davidson Trauma Scale [DTSI), anxiety (Spielberger State Inventory [STAI] Form Y-1), and mood (Profile of Mood States [POMS]) were obtained. Heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure were also measured. Results: The trauma-related exposure challenge induced anxiety on both days, with more marked responses on the ATD day according to VAS, DTS, POMS, and DBP (p < .05). A trend of significance (.1 > p >.05) was observed for STAI Form Y-1, HR, and SBP. Conclusions: These data demonstrate that ATD accentuates responses to trauma-related stimuli in SSRI-recovered PTSD. They also suggest that SSRI-induced increases in serotonin function restrain PTSD symptoms, especially under provocation, supporting a role for serotonin in mediating stress resilience.

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This study compared the effects of administering rosiglitazone (RSG) vs pioglitazone (PIO) oil cardiovascular disease risk factors in insulin-resistant. nondiabetic individuals with no apparent disease. Twenty-two nondiabetic, apparently healthy individuals, classified as being insulin resistant oil the basis of a steady-state plasma glucose concentration of at least 10 mmol/L during the insulin suppression test, were treated with either RSG or 1110 for 3 months. Measurements were made before and after drug treatment of weight; blood pressure; fasting and daylong glucose, insulin, and free fatty acid (FFA) levels; and lipid and lipoprotein concentrations. Insulin sensitivity (steady-state plasma glucose concentration) significantly improved in both treatment groups, associated with significant decreases in daylong plasma concentrations of glucose, insulin, and FFA. Diastolic blood pressure fell somewhat in both groups, and this change reached significance in those receiving PIO. Improvement in lipid metabolism was confined to the PIO-treated group, signified by a significant decrease in plasma triglyceride concentration, whereas triglyceride concentration did not decline in the RSG-treated group, and these individuals also had increases in total (P = .047) and low-density lipoprotein cholesterol (P = .07). In conclusion, RSG and PIO appear to have comparable abilities to improve insulin sensitivity and lower daylong glucose, insulin, and FFA concentrations in nondiabetic, insulin-resistant individuals. However, despite these similarities, their effects on lipoprotein metabolism seem to be quite different, with beneficial effects confined to PIO-treated individuals. (C) 2009 Elsevier Inc. All rights reserved.

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The etiology of irritable bowel syndrome (IBS) is complex and multifaceted. Psychosocial factors play a role in such a process. Several reports suggest that IBS patients have increased psychopathology scores as compared with population controls. The influence of depressive symptoms on rectal sensitivity thresholds vary across different studies. The influence of predominant bowel habits on rectal sensitivity thresholds as determined by barostat-based investigations is not well established. The present report aimed to investigate the influence of depressive symptoms on rectal sensitivity in different subtypes of IBS patients (diarrhea/constipation-predominant vs. alternating subtypes). Depressive symptoms correlated well with first pain sensitivity threshold in alternating patients (n = 8; [rho] = -0.77; p = 0.02) but not in diarrhea/constipation predominant symptoms (n = 11; [rho] = -0.44; p = 0.27). These data suggest that depressive symptoms might impact pain thresholds differently according to the subtype of IBS.

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Aim Stapled haemorrhoidopexy may damage the anorectal musculature and its sensorimotor function. Most studies have not used a barostat for the measurement of compliance. This study aimed to investigate the effect of stapled haemorrhoidopexy on rectal compliance and sensitivity. Method After Ethical Committee approval, we studied 10 male patients (mean age 33.8 years) with third- or fourth-degree haemorrhoids. Rectal compliance and sensitivity were measured with a 600-ml bag and an electronic barostat. Volunteers were submitted to two consecutive rectal distension protocols, including continuous distension at 2, 4 and 6 months after stapled haemorrhoidopexy. Intraluminal volume and pressure were recorded, including the first rectal sensation, desire to defecate and onset of rectal pain. Another group of 10 male control patients (mean age 24.9 years) with pilonidal sinus and no haemorrhoids was also included in the study. Results Two months after stapled haemorrhoidopexy, rectal compliance decreased (7.1 +/- 0.2 vs 5.3 +/- 0.1, 6.4 +/- 0.1 vs 5.1 +/- 0.1 and 5.6 +/- 0.2 vs 4.7 +/- 0.1 ml/mmHg for first rectal sensation, desire to defecate and rectal pain, respectively; P < 0.05). The sensitivity threshold volume did not change for the first sensation but decreased significantly for the desier to defecate and pain (p < 0.05) (116.8 +/- 13.8 vs 148.4 +/- 14.61, 251.1 +/- 8.9 vs 185.8 +/- 8.6 and 293.3 +/- 16.6 vs 221.2 +/- 6.0 ml for first rectal sensation, desire to defecate and rectal pain, respectively). Four and 6 months after surgery, rectal compliance and sensitivity returned to levels similar to those in the basal period. Muscle tissue was found in only three of the 10 resected doughnuts. Controls remained without any change in rectal compliance and sensitivity. Conclusion Stapled haemorrhoidopexy transiently decreases rectal compliance and sensitivity threshold in young male patients.

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Granulocyte-colony stimulating factor (G-CSF) is a current pharmacological approach to increase peripheral neutrophil counts after anti-tumor therapies. Pain is most relevant side effect of G-CSF in healthy volunteers and cancer patients. Therefore, the mechanisms of G-CSF-induced hyperalgesia were investigated focusing on the role of spinal mitogen-activated protein (MAP) kinases ERK (extracellular signal-regulated kinase). JNK (Jun N-terminal Kinase) and p38, and PI(3)K (phosphatidylinositol 3-kinase). G-CSF induced dose (30-300 ng/paw)-dependent mechanical hyperalgesia, which was inhibited by local post-treatment with morphine. This effect of morphine was reversed by naloxone (opioid receptor antagonist). Furthermore, G-CSF-induced hyperalgesia was inhibited in a dose-dependent manner by intrathecal pre-treatment with ERK (PD98059), JNK (SB600125), p38 (SB202190) or PI(3)K (wortmanin) inhibitors. The co-treatment with MAP kinase and PI(3)K inhibitors, at doses that were ineffective as single treatment, significantly inhibited G-CSF-induced hyperalgesia. Concluding, in addition to systemic opioids, peripheral opioids as well as spinal treatment with MAP kinases and PI(3)K inhibitors also reduce G-CSF-induced pain. (C) 2011 Elsevier Inc. All rights reserved.

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The present study investigated morpho-functional relations of the aortic depressor nerve (ADN) 5, 15 and 120 days after the onset of streptozotocin-induced diabetes in rats. Time control animals received vehicle. Under pentobarbital anesthesia, ADN activity was recorded simultaneously with arterial pressure. After the recordings, nerves were prepared for light microscopy study and morphometry. ADN function was accessed by means of pressure-nerve activity curve (fitted by sigmoidal regression) and cross-spectral analysis between mean arterial pressure (MAP) and ADN activity. The relation between morphological (myelinated fibers number and density, total myelin area, total fiber area and percentage of occupancy) and functional (gain, signal/noise relation, frequency) parameters were accessed by linear regression analysis and correlation coefficient calculations. Functional parameters obtained by means of the sigmoidal regression curve as well as by cross-spectral analysis were similar in diabetic and control rats. Morphometric parameters of the ADN were similar between groups 5 days after the onset of diabetes. Average myelin area and myelinated fiber area were significantly smaller on diabetic rats 15 and 120 days after the onset of diabetes, being the myelinated fiber and respective axons area and diameter also smaller on 120 days group. Nevertheless, G ratio (ratio between axon and fiber diameter) was nearly 0.6 and not different between groups or experimental times. No significant relationship between morphological and functional parameters was detected in all experimental groups. The present study suggests that ADN diabetic neuropathy was time-dependent, with damage to myelinated fibers to be the primary event, not evidenced by physiological methods. (C) 2010 Elsevier B.V. All rights reserved.

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Santos FM, Dias DPM, Silva CAA, Fazan Jr R, Salgado HC. Sympathetic activity is not increased in L-NAME hypertensive rats. Am J Physiol Regul Integr Comp Physiol 298: R89-R95, 2010. First published November 4, 2009; doi:10.1152/ajpregu.00449.2009.-The role played by the sympathetic drive in the development of N(G)-nitro-L-arginine methyl ester (L-NAME)-induced hypertension is not firmly established. Therefore, the present study was undertaken in conscious rats in which hypertension was induced by treatment with L-NAME over the course of either 2 or 14 days. Mean arterial pressure (MAP) was measured via a catheter placed in the femoral artery, drugs were administered via a cannula placed in the femoral vein, and renal sympathetic nerve activity (RSNA) was monitored using an implanted electrode. Despite the remarkable increase in arterial pressure, heart rate did not change after treatment with L-NAME. RSNA was similar in L-NAME-induced hypertensive rats treated over the course of 2 or 14 days, as well as in normotensive rats. It was also demonstrated that L-NAME-induced hypertensive rats displayed a resetting of the baroreflex control of RSNA to hypertensive levels, with decreased sensitivity over the course of 2 or 14 days. Furthermore, the sympathetic-vagal balance examined in the time and frequency domain and the renal and plasma norepinephrine content did not differ between groups. In conclusion, the evaluation of the sympathetic drive in conscious rats demonstrated that the arterial hypertension induced by L-NAME treatment over the course of 2 and 14 days does not show sympathetic overactivity.