BioFoot in-shoe system: Normal values and assessment of the reliability and repeatability

BackgroundBioFoot^® is an in-shoe system to measure plantar pressures at the interface between the shoe and the sole of the foot. Since reliability and good repeatability are necessary to ensure the consistency of measurements on which clinical judgements are based, the aim of the study was to assess the reliability and repeatability of the BioFoot^® system and identify normal values for healthy subjects.Materials and methodsThirty subjects, 18 women and 12 men, were measured twice, with a 7–10 day interval between the sessions, wearing the same kind of shoes. In each session, three trials were recorded. The foot was divided into ten areas: heel, midfoot, whole forefoot, 1st–5th metatarsal heads, hallux, and lesser toes.ResultsThe intra-class correlation coefficients were between 0.76 and 0.96 for all four variables evaluated. The coefficient of variation between two sessions was around 7% (range: 4.6–9%). The mean contact time was 0.81 s, and walking cadence was 101.5 steps per minute. The pressure measurements showed the greatest peak and mean pressures under the second metatarsal head, and the second peak and mean pressures under the third metatarsal head.ConclusionThe plantar pressure measurements showed good to excellent consistency, and it was concluded that the BioFoot^® in-shoe system has good reliability and is repeatable. The highest values were found beneath the forefoot, which is consistent with the literature.     

The decrease in serum IL-18 levels after bariatric surgery in morbidly obese women is a time-dependent event

Background We have evaluated the impact of the reproductive status of morbidly obese women, and of the time elapsed since surgery, on the response of the proinflammatory serum cardiovascular risk marker interleukin-18 (IL-18) to the sustained and marked weight loss achieved after bariatric surgery. Methods Serum IL-18 levels were measured in 33 morbidly obese women before bariatric surgery and after losing at least 15% of the initial weight, irrespective of the time needed to achieve this goal (5 to 33 months). Results Patients lost 30.7 ± 7.8% of the initial weight, with a concomitant reduction of serum IL-18 concentrations (P < 0.001). A stepwise multiple regression analysis showed that the percentual decrease in serum IL-18 levels was determined by the interaction between the time elapsed since surgery and the percentual reduction of waist circumference (R² = 0.333, F = 15.500, β = 0.577, P < 0.001), but not by the individual effects of the time elapsed since surgery, percentual body weight loss, percentual reduction of waist circumference, menopausal status or type of surgical procedure, or by the interaction between the time elapsed since surgery with the percentual body weight loss or with menopausal status. Conclusion Serum IL-18 levels decrease after bariatric surgery in a time-dependent manner, in relation to the reduction in waist circumference. The fact that the amelioration of the obesity-associated inflammatory process requires time and not only weight loss, might contribute to explain early non-surgical cardiovascular complications of bariatric surgery.     

Prevalence and Severity of Sleep Apnea in a Group of Morbidly Obese Patients

Background Obesity is the most important risk factor for obstructive sleep apnea. It is estimated that 70% of sleep apnea patients are obese. In the morbidly obese, the prevalence may reach 80% in men and 50% in women. The aim of this study was to determine the prevalence and severity of sleep apnea in a group of morbidly obese patients, leading to bariatric surgery. Methods In a cross-sectional study developed in Bahia, northeastern Brazil. 108 patients (78 women and 30 men) from the Obesity Treatment and Surgery Center - “Núcleo de Tratamento e Cirurgia da Obesidade” underwent standard polysomnography. Patients with an apnea-hypopnea index (AHI) ≥ 5 events/hour were considered apneic. Results Mean ± SD for age and BMI were 37.1 ± 10.2 years and 45.2 ± 5.4 kg/m2, respectively. The calculated AHI ranged widely from 2.5 to 128.9 events/hour. Sleep apnea was detected in 93.6% of the sample, wherein 35.2% had mild, 30.6% moderate and 27.8% severe apnea. Oxyhemoglobin desaturation was directly related to the AHI and was more severe in men. Conclusion There was a high frequency of sleep apnea in this group of morbidly obese patients, for whom it was very important to request polysomnography, thus enabling therapeutic management and prognostication.     

Basal forebrain cholinergic system of the anuran amphibian Rana perezi: evidence for a shared organization pattern with amniotes

The organization of the basal forebrain cholinergic system (BFCS) in the frog was studied by means of choline acetyltransferase (ChAT) immunohistochemistry. The BFCS was observed as a conspicuous cholinergic cell population extending through the diagonal band, medial septal nucleus, bed nucleus of the stria terminalis, and pallidal regions. Abundant fiber labeling was also found around the labeled cell bodies. The combination of retrograde tract tracing with dextran amines and ChAT immunohistochemistry revealed intraseptal and intra-BFCS cholinergic connections. In addition, an extratelencephalic cholinergic input from the laterodorsal tegemental nucleus was demonstrated. The possible influence of monoaminergic inputs on the BFCS neurons was examined by means of tyrosine hydroxylase and serotonin immunohistochemistry combined with ChAT immunolabeling. Our results showed that catecholaminergic fibers overlapped the BFCS, with the exception of the medial septal nucleus. Serotoninergic innervation was widespread, but less abundant in the caudal extent of the BFCS. Taken together, our results on the localization of the cholinergic neurons in the basal forebrain and their relationship with cholinergic, catecholaminergic, and serotoninergic afferents have shown numerous common features with amniotes. In particular, anurans and mammals (for which most data is available) share a strikingly comparable organization pattern of the BFCS.     

'Functional' neuroanatomical tract tracing: analysis of changes in gene expression of brain circuits of interest

Neuroanatomical tracing when considered as an isolated method produces relatively straightforward answers. Although single-, double- or even triple-tracing paradigms produce valuable data on the organization of brain circuits, the final outcome often is too simplistic since it is not possible to elucidate the activity of these circuits. In this regard, emerging technologies contribute with additional information about the status of neuronal circuits. The laser-guided capture microdissection microscope (LCM) allows the accurate dissection of small brain areas under the microscope that could be further analyzed for gene expression or proteomics. In order to elucidate the gene expression of a given circuit of interest, we have developed a combination of methods comprising (i) fluorescent non-radioactive in situ hybridization for the detection of vGLUT2 mRNA expression combined with retrograde tracing with Fluoro-Gold (FG; analysis performed under the confocal microscope) and (ii) laser-guided capture microdissection of brain areas containing neurons retrogradely labeled with FG followed by the measurement of changes in mRNA levels encoding for vGLUT2 by real-time PCR. Our goal was to detect changes in gene expression of the thalamostriatal pathway in unilaterally 6-OHDA lesioned rats. Taking advantage of this procedure, we found a three-fold increase in vGLUT2 mRNA expression within thalamic neurons projecting to the dopamine-depleted striatum when compared with the activity of the thalamic neurons innervating the control striatum.     

Denial in the first days of acute stroke

Denial is a disorder of self-awareness that is frequent after acute stroke, with potential negative influence in the care of patients. The aim of this study was to describe the presence and correlates of denial in acute stroke. We assessed denial in a sample of 180 consecutive acute stroke patients (≤4 days) and in a control group of 50 acute coronary patients using the Denial of Illness Scale (DIS). 41% (74) acute stroke patients (mean DIS score=4.1, SD=2.2, range 0 to 10) and 24% (12) acute coronary patients (mean DIS score=3.2, SD=1.5, range 0 to 10) presented denial (χ²=4.19, p=.04; U=3405.50, p=.01). Denial was more frequent and severe in patients with lower educational level (χ² = 5.04, p=.04; U=2110.50; p=.01), neglect (χ² = 21.38, p=.00; U=1130.50; p=.00), cognitive impairment (χ² = 6.27, p=.02; U=1181.50; p=.01) and after hemispherical lesions (χ² =4.68, p=.05; U=1982.50; p=.04). In logistic regression low educational level, neglect and cognitive impairment were independent factors predicting denial in stroke patients (R²= 21%). Patients with denial can express depressive symptoms. Patients with denial had a worse outcome at discharge (χ² =4.91, p=.04; U=2918.00; p=.03). Denial is a frequent phenomenon after acute stroke. We propose that there is a multifactorial model for the emergence of denial, lower educational as a predisposing condition, and acute stroke due to hemisphere lesion and causing neglect and cognitive impairment as precipitating events. All these factors limit patients’ assessment of their condition and body functions.     

Glial cell line-derived neurotrophic factor promotes the arborization of cultured striatal neurons through the p42/p44 mitogen-activated protein kinase pathway

Glial cell line-derived neurotrophic factor (GDNF) promotes the survival or differentiation of several types of neurons. This study examines GDNF-induced signal transduction and biological effects in cultured striatal neurons. Results show that GDNF addition to striatal cultures transiently increased the protein levels of phosphorylated p42/p44, but did not change the levels of phosphorylated Akt. GDNF effects on phosphorylated p42/p44 levels were blocked by the mitogen-activated protein kinase (MAPK) pathway specific inhibitors (PD98059 and U0126). Activation of the p42/p44 MAPK pathway by GDNF led to an increase in the degree of dendritic arborization and axon length of both GABA- and calbindin-positive neurons but had no effect on their survival and maturation. These GDNF-mediated effects were suppressed in the presence of the inhibitor of the MAPK pathway (PD98059). Furthermore, the addition of the phosphatidylinositol 3-kinase pathway specific inhibitor (LY294002) blocked GDNF-mediated striatal cell differentiation suggesting that the basal activity of this pathway is needed for the effects of GDNF. Our results indicate that treatment of cultured striatal cells with GDNF specifically activates the p42/p44 MAPK pathway, leading to an increase in the arborization of GABA- and calbindin-positive neurons.     

Anxiolytic-like effect of cannabidiol in the rat Vogel conflict test

Cannabidiol (CBD) is a major constituent of the Cannabis sativa plant. It inhibits the anxiogenic activity of high doses of Δ⁹-tetrahydrocannabinol and induces anxiolytic-like effects. However, the mechanisms underlying the actions of CBD are unknown. Therefore, the aim of the present study was to test the effects of CBD in the Vogel test, a widely used animal model of anxiety. In addition, it was verified if these effects would depend on benzodiazepine-receptor activation. After 24 h of water deprivation, male Wistar rats were subjected to an initial 3-min non-punished (pre-test) drinking session. This was followed by an additional 24-h period of water deprivation followed by a 3-min punished-licking session (test). Diazepam (3 mg/kg) or CBD (2.5, 5 or 10 mg/kg) were intraperitoneally injected 30 min before the test session. CBD (10 mg/kg) and diazepam had similar anticonflict effects, increasing the number of punished licks. The effect of diazepam, but not of CBD, was prevented by the benzodiazepine-receptor antagonist flumazenil (10 mg/kg). To exclude that the anticonflict effects were reflecting non-specific drug effects, we checked the effects of CBD on water consumption and nociceptive response. The drug did not interfere on the former variable in a non-punished test session. Moreover, contrary to morphine (5 mg/kg), CBD was ineffective in the tail-flick test. In conclusion, CBD induced an anticonflict effect not mediated by benzodiazepine receptors or by non-specific drug interference on nociceptive threshold or water consumption. These results reinforce the hypothesis that this cannabinoid has anxiolytic properties.     

Nitric oxide synthase in retina and optic nerve head of rat with increased intraocular pressure and effect of timolol

We investigated the expression of nitric oxide synthase (NOS) isoforms -1, -2 and -3 in the retina and optic nerve head (ONH) in an experimental rat model of elevated intraocular pressure (IOP) before and after treatment with timolol, to assess whether its neuroprotective action is associated with the activity of these enzymes. Episcleral vein cauterization in unilateral eyes of Wistar rats was performed to produce elevated IOP. Histological sections of retina and ONH from animals with normal IOP, with elevated IOP, and elevated IOP treated with timolol, were studied by immunohistochemistry with antibodies to NOS-1, NOS-2, and NOS-3. In the control rats, NOS-1 was localized to photoreceptor inner segments, amacrine cells and bipolar cells in the retina, and in astrocytes, pericytes and vascular nitrergic terminals in the ONH. NOS-3 immunostaining localized to the endothelial cells. The rats with elevated IOP showed increased expression of NOS-1 in the plexiform layers of the retina and reactive astrocytes in the ONH. These cells also showed NOS-2 positivity. The rats treated with timolol showed reduced expression of NOS-1 in the retina and ONH. NOS-2 was only detected in a few groups of astrocytes in the ONH. NOS-3 was unchanged in both elevated IOP and timolol-treated groups. These results show that excessive levels of NO synthesized by the NOS-1 and -2 isoforms, considered neurotoxic, might contribute to the progressive lesions of retinal ganglion cell axons. Their reduction after treatment suggests a possible neuroprotective effect of timolol in neurons exposed to excessive amounts of NO.     

Pronounced individual variation in the response to the stimulatory action of exercise on immature hippocampal neurons

In the adult hippocampus, neurogenesis is influenced both by external stimuli, such as physical exercise, and by intrinsic conditions like age and disease. However, the way in which many of these external and internal cues interact in this process remains poorly understood. We have used a new, more precise, stereological cell counting method that involves confocal microscopy to analyze the effects of exercise on adult neurogenesis in the mouse. We found that treadmill exercise increases the number of differentiating neurons (doublecortin/calretinin cells) in the granule cell layer of the mouse hippocampus in a manner that is directly related to the size of the mature granule cell population. More immature neurons were found after exercise in animals that had a larger dentate gyrus (DG), while no changes were observed in those with a smaller DG. This differential response to physical exercise suggests that the pre-existing neuronal population regulates the neurogenic response in the DG to external stimuli. These data raise the possibility of anticipating an individuals' response to therapeutic interventions (like exercise) aimed at augmenting dentate neurogenesis and alleviating or preventing cognitive decline.