Interhemispheric Asymmetry of Corticomotor Excitability After Chronic Cerebellar Infarcts

Early after stroke, there is loss of intracortical facilitation (ICF) and increase in short-interval intracortical inhibition (SICI) in the primary motor cortex (M1) contralateral to a cerebellar infarct. Our goal was to investigate intracortical M1 function in the chronic stage following cerebellar infarcts (> 4 months). We measured resting motor threshold (rMT), SICI, ICF, and ratios between motor-evoked potential amplitudes (MEP) and supramaximal M response amplitudes (MEP/M; %), after transcranial magnetic stimulation was applied to the M1 contralateral (M1(contralesional)) and ipsilateral (M1(ipsilesional)) to the cerebellar infarct in patients and to both M1s of healthy age-matched volunteers. SICI was decreased in M1(contralesional) compared to M1(ipsilesional) in the patient group in the absence of side-to-side differences in controls. There were no significant interhemispheric or between-group differences in rMT, ICF, or MEP/M (%). Our results document disinhibition of M1(contralesional) in the chronic phase after cerebellar stroke.

Inhibition of motor cortex excitability with 15 Hz transcranial alternating current stimulation (tACS)

There remains a lack of solid evidence showing whether transcranial stimulation with weak alternating current (transcranial alternating current stimulation, tACS) can in fact induce significant neurophysiological effects. Previously, a study in which tACS was applied for 2 and 5 min with current density = 0.16-0.25 A/m(2) was unable to show robust effects on cortical excitability. Here we applied tACS at a significantly higher current density (0.80 A/m(2)) for a considerably longer duration (20 min) and were indeed able to demonstrate measurable changes to cortical excitability. Our results show that active 15 Hz tACS of the motor cortex (electrodes placed at C3 and C4) significantly diminished the amplitude of motor evoked potentials and decreased intracortical facilitation (ICF) as compared to baseline and sham stimulation. In addition, we show that our method of sham tACS is a reliable control condition. These results support the notion that AC stimulation with weak currents can induce significant changes in brain excitability; in this case, 15 Hz tACS led to a pattern of inhibition of cortical excitability. We propose that tACS may have a dampening effect on cortical networks and perhaps interfere with the temporal and spatial summation of weak subthreshold electric potentials. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Alteration of cortical excitability in patients with fibromyalgia

We assessed cortical excitability and intracortical modulation systematically, by transcranial magnetic stimulation (TMS) of the motor cortex, in patients with fibromyalgia. In total 46 female patients with fibromyalgia and 21 normal female subjects, matched for age, were included in this study. TMS was applied to the hand motor area of both hemispheres and motor evoked potentials (MEPs) were recorded for the first interosseous muscle of the contralateral hand. Single-pulse stimulation was used for measurements of the rest motor threshold (RMT) and suprathreshold MEP. Paired-pulse stimulation was used to assess short intracortical inhibition (SICI) and intracortical facilitation (ICF). Putative correlations were sought between changes in electrophysiological parameters and major clinical features of fibromyalgia, such as pain, fatigue, anxiety, depression and catastrophizing. The RMT on both sides was significantly increased in patients with fibromyalgia and suprathreshold MEP was significantly decreased bilaterally. However, these alterations, suggesting a global decrease in corticospinal excitability, were not correlated with clinical features. Patients with fibromyalgia also had lower ICF and SICI on both sides, than controls, these lower values being correlated with fatigue, catastrophizing and depression. These neurophysiological alterations were not linked to medication, as similar changes were observed in patients with or without psychotropic treatment. In conclusion, fibromyalgia is associated with deficits in intracortical modulation involving both GABAergic and glutamatergic mechanisms, possibly related to certain aspects of the pathophysiology of this chronic pain syndrome. Our data add to the growing body of evidence for objective and quantifiable changes in brain function in fibromyalgia. (C) 2010 International Association for the Study of Pain. Published by Elsevier B. V. All rights reserved.

Recovery of Renal Function in Heart Transplantation Patients After Conversion From a Calcineurin Inhibitor-Based Therapy to Sirolimus

Background. Renal failure is the most important comorbidity in patients with heart transplantation, it is associated with increased mortality. The major cause of renal dysfunction is the toxic effects of calcineurin inhibitors (CNI). Sirolimus, a proliferation signal inhibitor, is an imunossupressant recently introduced in cardiac transplantation. Its nonnephrotoxic properties make it an attractive immunosuppressive agent for patients with renal dysfunction. In this study, we evaluated the improvement in renal function after switching the CNI to sirolimus among patients with new-onset kidney dysfunction after heart transplantation. Methods. The study included orthotopic cardiac transplant (OHT) patients who required discontinuation of CNI due to worsening renal function (creatinine clearance <50 mL/min). We excluded subjects who had another indication for initiation of sirolimus, that is, rejection, malignancy, or allograft vasculopathy. The patients were followed for 6 months. The creatinine clearance (CrCl) was estimated according to the Cockcroft-Gault equation using the baseline weight and the serum creatinine at the time of introduction of sirolimus and 6 months there after. Nine patients were included, 7 (78%) were males and the overall mean age was 60.1 +/- 12.3 years and time since transplantation 8.7 +/- 6.1 years. The allograft was beyond 1 year in all patients. There was a significant improvement in the serum creatinine (2.98 +/- 0.9 to 1.69 +/- 0.5 mg/dL, P = .01) and CrCl (24.9 +/- 6.5 to 45.7 +/- 17.2 mL/min, P = .005) at 6 months follow-up. Conclusion. The replacement of CNI by sirolimus for imunosuppressive therapy for patients with renal failure after OHT was associated with a significant improvement in renal function after 6 months.

Salbutamol improves markers of epithelial function in mice with chronic allergic pulmonary inflammation

We investigated the effects of salbutamol on the markers of epithelial function in a murine model of chronic allergic pulmonary inflammation by recording the ciliary beat frequency (CBF) and the transepithelial potential difference (PD) in vivo. Mice were sensitized and received four challenges of ovalbumin (OVA group) or 0.9% saline (control group). Forty-eight hours after the 4th inhalation, we observed eosinophilia in the bronchoalveolar lavage and epithelium remodeling with stored acid mucus in the OVA group (P < 0.001). No difference in the baseline CBF was noticed between the groups; however, the OVA group had a significantly lower baseline PD (P = 0.013). Salbutamol increased the CBF in all groups studied, and the dose response curve to salbutamol increased the PD in the OVA group from 10(-4) M to 10(-2) M. We suggest that salbutamol affects the CBF and the depth of the periciliary layer, which, in great part, determines the ability of the cilia to propel the mucus layer. This effect may have a positive impact on airway mucociliary transport in asthma and may have clinical implications. (C) 2011 Elsevier B.V. All rights reserved.

Brainstem pathology and non-motor symptoms in PD

Parkinson`s disease (PD) is considered a multisystem disorder involving dopaminergic, noradrenergic. serotoninergic. and cholinergic systems, characterized by motor and non-motor symptoms. The causes of the non-motor symptoms in PD are multifactorial and unlikely to be explained by single lesions However, several evidence link them to damage of specific brainstem nuclei Numerous brainstem nuclei are engaged in fundamental homeostatic mechanisms, including gastrointestinal regulation, pain perception, mood control, and sleep-wake cycles In addition, these nuclei are locally interconnected in a complex manner and are subject to supraspinal control. The objective of this review is to provide a better overview of the current knowledge about the consequences of the involvement of specific brainstem nuclei to the most prevalent non-motor symptoms occurring in PD The multidisciplinary efforts of research directed to these non-nigral brainstem nuclei, in addition to the topographical and chronological spread of the disease - especially in the prodromal stages of PD. are discussed (C) 2009 Elsevier B V. All rights reserved

Increased number and function of natural killer cells in human immunodeficiency virus 1-positive subjects co-infected with herpes simplex virus 2

P>Natural killer (NK) cells bridge the interface between innate and adaptive immunity and are implicated in the control of herpes simplex virus 2 (HSV-2) infection. In subjects infected with human immunodeficiency virus 1 (HIV-1), the critical impact of the innate immune response on disease progression has recently come into focus. Higher numbers of NK cells are associated with lower HIV-1 plasma viraemia. Individuals with the compound genotype of killer cell immunoglobulin-like receptor (KIR) 3DS1 and human leucocyte antigen (HLA)-Bw4-80I, or who have alleles of KIR3DL1 that encode proteins highly expressed on the NK cell surface, have a significant delay in disease progression. We studied the effect of HSV-2 co-infection in HIV-1-infected subjects, and show that HSV-2 co-infection results in a pan-lymphocytosis, with elevated absolute numbers of CD4+ and CD8+ T cells, and NK cells. The NK cells in HSV-2 co-infected subjects functioned more efficiently, with an increase in degranulation after in vitro stimulation. The number of NK cells expressing the activating receptors NKp30 and NKp46, and expressing KIR3DL1 or KIR3DS1, was inversely correlated with HIV-1 plasma viral load in subjects mono-infected with HIV-1, but not in subjects co-infected with HSV-2. This suggests that HSV-2 infection mediates changes within the NK cell population that may affect immunity in HIV-1 infection.

THE EFFECTS OF BROMAZEPAM ON THE PERFORMANCE OF A SENSORY-MOTOR ACTIVITY: AN ELECTROENCEPHALOGRAPHIC STUDY

Aims. To investigate the effects of using bromazepam on the relative power in alpha while performing a typing task. Bearing in mind the particularities of each brain hemisphere, our hypothesis was that measuring the relative power would allow its to investigate the effects of bromazepam oil specific areas of the cortex. More, specifically, we expected to observe different patterns of powers in sensory-motor integration, attention and activation processes. Subjects and methods. The sample was made up of 39 subjects (15 males and 24 females) with a mean age of 30 +/- 10 years. The control (placebo) and experimental (3 mg and 6 mg of bromazepam) groups were trained ill the typing task with a randomised double-blind model. Results. A three-way ANOVA and Scheffe test were used to analyse interactions between the factors condition and moment, and between condition and sector Conclusions. The doses used ill this study facilitated motor performance of the typing task. Ill this study, the use of the drug did not prevent learning of the task, but it did appear to concentrate mental effort on more restricted and specific aspects of typing. It also seemed to influence the rhythm and effectiveness of the operations performed during mechanisms related to the encoding and storage often, information. Likewise, a predominance of activity was observed in the left (dominant) frontal area in the 3 mg bromazepam group, which indicates that this close of the drug affords the subject a greater degree of directionality of cortical activity for planning and performing the task. [REV NEUROL 2009; 49: 295-9]

Genetic association and cellular function of MC1R variant alleles in human pigmentation

We have examined MC1R variant allele frequencies in the general population of South East Queensland and in a collection of adolescent dizygotic and monozygotic twins and family members to define statistical associations with hair and skin color, freckling, and mole count. Results of these studies are consistent with a linear recessive allelic model with multiplicative penetrance in the inheritance of red hair. Four alleles, D84E, R151C, R160W, and D294H, are strongly associated with red hair and fair skin with multinomial regression analysis showing odds ratios of 63, 118, 50, and 94, respectively. An additional three low-penetrance alleles V60L, V92M, and R163Q have odds ratios 6, 5, and 2 relative to the wild-type allele. To address the cellular effects of MC1R variant alleles in signal transduction, we expressed these receptors in permanently transfected HEK293 cells. Measurement of receptor activity via induction of a cAMP-responsive luciferase reporter gene found that the R151C and R160W receptors were active in the presence of NDP-MSH ligand, but at much reduced levels compared with that seen with the wild-type receptor. The ability to stimulate phosphorylation of the cAMP response element binding protein (CREB) transcription factor was also apparent in all stimulated MC1R variant allele-expressing HEK293 cell extracts as assessed by immunoblotting. In contrast, human melanoma cell lines showed wide variation in the their ability to undergo cAMP-mediated CREB phosphorylation. Culture of human melanocytes of known MC1R genotype may provide the best experimental approach to examine the functional consequences for each MC1R variant allele. With this objective, we have established more than 300 melanocyte cell strains of defined MC1R genotype.

Kidney Function and 24-Hour Proteinuria in Patients with Fabry Disease during 36 Months of Agalsidase Alfa Enzyme Replacement Therapy: A Brazilian Experience

Background. Prior to the introduction of enzyme replacement therapy (ERT), management of Fabry disease (FD) consisted of symptomatic and palliative measures. ERT has been available for several years using recombinant human agalsidase alfa, an analogue of alpha-galactosidase A (GALA). However, the limitations of ERT in improving kidney function have not been established. This study evaluates the safety and therapeutic effect of agalsidase alfa replacement in terms of kidney function and reduction in 24-hour proteinuria. Methods. During the period between January 1, 2002, and August 1, 2005, nine Fabry patients (7 male, 2 female) were treated according to protocol, receiving 0.2 mg/kg agalsidase alfa IV every two weeks. Kidney function was evaluated by measuring the glomerular filtration rate (GFR) using chromium ethylene diamine tetra-acetate clearance ((51)Cr-EDTA mL/min/1.73 m(2)) at baseline, 12, 24, and 36 months. 24-hour proteinuria was measured at baseline, 3, 6, 12, 18, 24, and 36 months of ERT. Kidney disease was classified according to National Kidney Foundation Disease Outcome Quality Initiative (NKF/DOQI) Advisory Board criteria, which define stage I chronic kidney disease (CKD) as GFR >= 90mL/min/1.73 m(2), stage II as 60-89 mL/min/1.73m(2), stage III as 30-59 mL/min/1.73 m(2), stage IV as 15-29 mL/min/1.73m(2), and stage V as < 15 mL/min/1.73m(2). Results. Six patients completed 36 months of therapy, 2 patients completed 18 months, and 1 patient completed 12 months. Mean patient age at baseline was 34.6 +/- 11.3 years. During the study period, kidney function remained stable in patients with stages I, II, or III CKD. One patient, who entered the study with stage IV CKD, progressed to end-stage chronic kidney disease, beginning hemodialysis after 7 months and receiving a kidney transplant after 12 months of ERT. Proteinuria also remained stable in the group of patients with pathologic proteinuria. The use of agalsidase alfa was well tolerated in 99.5% of the infusions administered. Conclusion. Over the course of 36 months of ERT, there was no change in kidney function and 24-hour proteinuria. This suggests thatagalsidase alfa may slow or halt the progression of kidney disease when used before extensive kidney damage occurs. No significant side effects were observed with ERT during the course of the study.

The role played by the parietoocciptal cortex in the process of sensory-motor integration: An electroencephalographic study

Introduction. A fundamental aspect of planning future actions is the performance and control of motor tasks. This behaviour is done through sensory-motor integration. Aim. To explain the electrophysiological mechanisms in the cortex (modifications to the alpha band) that are involved in anticipatory actions when individuals have to catch a free-falling object. Subjects and methods. The sample was made up of 20 healthy subjects of both sexes (11 males and 9 females) with ages ranging between 25 and 40 years (32.5 +/- 7.5) who were free of mental or physical diseases (previous medical history); the subjects were right-handed (Edinburgh Inventory) and were not taking any psychoactive or psychotropic substances at the time of the study. The experiment consisted in a task in which subjects had to catch freely falling objects. The experiment was made up of six blocks of 15 tests, each of which lasted 2 minutes and 30 seconds before and two seconds after each ball was dropped. Results. An interaction of the factors moment and position was only observed for the right parietooccipital cortex, in the combination of electrodes P4-O2. Conclusion. These findings suggest that the right parietooccipital cortex plays an important role in increasing expectation and swiftness in the process of preparing for a motor task.

New SMS mutation leads to a striking reduction in spermine synthase protein function and a severe form of Snyder-Robinson X-linked recessive mental retardation syndrome

We report the identification of a novel mutation at a highly conserved residue within the N-terminal region of spermine synthase (SMS) in a second family with Snyder-Robinson X-linked mental retardation syndrome ( OMIM 309583). This missense mutation, p.G56S, greatly reduces SMS activity and leads to severe epilepsy and cognitive impairment. Our findings contribute to a better delineation and expansion of the clinical spectrum of Snyder-Robinson syndrome, support the important role of the N-terminus in the function of the SMS protein, and provide further evidence for the importance of SMS activity in the development of intellectual processing and other aspects of human development.

The role of BPH, lower urinary tract symptoms, and PSA levels on erectile function of Brazilian men who undergo prostate cancer screening

Introduction. Lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) are common problems in middle-aged and older men. Recently, epidemiologic studies have shown significant associations between severity of LUTS and male sexual dysfunction. Aim. We analyzed the role of prostate enlargement, LUTS, and prostate specific antigen (PSA) levels in the erectile function of Brazilian men who underwent prostate cancer (PCa) screening. Method. We analyzed data from 1,008 consecutive patients enrolled in a PCa screening program. Benign prostatic hyperplasia (BPH) was defined as a prostate weight greater than 30 g as defined by digital rectal examination. For statistical analysis, we used the chi-squared and analysis of variance tests. The odds ratios (OR) for correlation of ED with prostate volume LUTS and PSA were estimated using logistic regression models. Main Outcome Measure. The American Urological Association (AUA) symptom score for LUTS and the International Index of Erectile Function. Results. Mean patient age was 61.2 years (45-87) and median PSA value was 1.9 ng/mL. BPH was identified in 48.5% of patients. Mild, moderate, and severe LUTS were found in 52.3%, 30.9%, and 16.8% of cases, respectively. ED was classified as absent, mild, mild to moderate, moderate, and severe in 18.6%, 23.1%, 18.6%, 15.2%, and 24.5%, respectively. While only 5.4% of the patients with no ED presented severe LUTS, this finding was observed in 27.1% of patients with severe ED (P<0.001). Univariate logistic regression analysis demonstrated that age, prostate volume, AUA symptom score, and PSA levels were significant predictors of ED. However, when controlled for patient age, only LUTS remained as an independent predictor of ED. Conclusions. Controlling for patient age, LUTS are independent risk factors for the development of ED among Brazilian men who undergo PCa screening.

Altered endothelial function following the Fontan procedure

Objective: Thrombosis has been widely described after the Fontan procedure. The vascular endothelium plays a central role in the control of coagulation and fibrinolysis. The aim of this study was to investigate if patients undergoing a modified Fontan procedure have impaired endothelial function and fibrinolysis in the late postoperative course. Patients and methods: We compared 23 patients aged from 7 to 26 years with age-matched healthy volunteers, collecting blood samples prior to and following standardized venous occlusion testing. Plasma levels of von Willebrand factor antigen, tissue-type plasminogen activator antigen, plasminogen activator inhibitor-1, and D-dimer were measured with enzyme-linked immunosorbent assay. Results: We found increased plasma levels of von Willebrand factor antigen in patients when compared to controls (p = 0.003). At the basal condition, concentrations of tissue-type plasminogen activator antigen and plasminogen activator inhibitor-1 antigen in the plasma, as well as their activity, were not significantly different between patients and controls. Following venous occlusion, concentrations of tissue-type plasminogen activator antigen in the plasma were significantly increased both in patients and controls, compared to pre-occlusion values. D-dimer was within the reference range. Multivariate discriminant analysis differentiated patients and their controls on the basis of differences for plasminogen activator inhibitor-1 and von Willebrand factor antigen (p = 0.0016). Conclusions: Our data suggest that patients with the Fontan circulation may have endothelial dysfunction, as indicated by raised levels of von Willebrand factor. Fibrinolysis seems to be relatively preserved, as suggested by appropriate response to venous occlusion.