1000 resultados para Medical Subject Headings::Anatomy::Cells::Stem Cells::Neural Stem Cells
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CONTEXT: Cirrhosis after viral hepatitis has been identified as a risk factor for osteoporosis in men. However, in postmenopausal women, most studies have evaluated the effect of primary biliary cirrhosis, but little is known about the effect of viral cirrhosis on bone mass [bone mineral density (BMD)] and bone metabolism. OBJECTIVE: Our objective was to assess the effect of viral cirrhosis on BMD and bone metabolism in postmenopausal women. DESIGN: We conducted a cross-sectional descriptive study. SETTING AND PATIENTS: We studied 84 postmenopausal female outpatients with viral cirrhosis and 96 healthy postmenopausal women from the general community. BMD was measured by dual-energy x-ray absorptiometry at lumbar spine (LS) and femoral neck (FN). RESULTS: The percentage with osteoporosis did not significantly differ between patients (LS, 43.1%; FN, 32.2%) and controls (LS, 41.2%; FN, 29.4%), and there was no difference in BMD (z-score) between groups. Serum concentrations of soluble TNF receptors, estradiol, and osteoprotegerin (OPG) were significantly higher in patients vs. controls (P < 0.001, P < 0.05, and P < 0.05, respectively). No significant difference was observed in urinary deoxypyridinoline. Serum OPG levels were positively correlated with soluble TNF receptors (r = 0.35; P < 0.02) and deoxypyridinoline (r = 0.37; P < 0.05). CONCLUSIONS: This study shows that bone mass and bone resorption rates do not differ between postmenopausal women with viral cirrhosis and healthy postmenopausal controls and suggests that viral cirrhosis does not appear to increase the risk of osteoporosis in these women. High serum estradiol and OPG concentrations may contribute to preventing the bone loss associated with viral cirrhosis in postmenopausal women.
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BACKGROUND This study was realized thanks to the collaboration of children and adolescents who had been resected from cerebellar tumors. The medulloblastoma group (CE+, n = 7) in addition to surgery received radiation and chemotherapy. The astrocytoma group (CE, n = 13) did not receive additional treatments. Each clinical group was compared in their executive functioning with a paired control group (n = 12). The performances of the clinical groups with respect to controls were compared considering the tumor's localization (vermis or hemisphere) and the affectation (or not) of the dentate nucleus. Executive variables were correlated with the age at surgery, the time between surgery-evaluation and the resected volume. METHODS The executive functioning was assessed by means of WCST, Complex Rey Figure, Controlled Oral Word Association Test (letter and animal categories), Digits span (WISC-R verbal scale) and Stroop test. These tests are very sensitive to dorsolateral PFC and/or to medial frontal cortex functions. The scores for the non-verbal Raven IQ were also obtained. Direct scores were corrected by age and transformed in standard scores using normative data. The neuropsychological evaluation was made at 3.25 (SD = 2.74) years from surgery in CE group and at 6.47 (SD = 2.77) in CE+ group. RESULTS The Medulloblastoma group showed severe executive deficit (= 1.5 SD below normal mean) in all assessed tests, the most severe occurring in vermal patients. The Astrocytoma group also showed executive deficits in digits span, semantic fluency (animal category) and moderate to slight deficit in Stroop (word and colour) tests. In the astrocytoma group, the tumor's localization and dentate affectation showed different profile and level of impairment: moderate to slight for vermal and hemispheric patients respectively. The resected volume, age at surgery and the time between surgery-evaluation correlated with some neuropsychological executive variables. CONCLUSION Results suggest a differential prefrontal-like deficit due to cerebellar lesions and/or cerebellar-frontal diaschisis, as indicate the results in astrocytoma group (without treatments), that also can be generated and/or increased by treatments in the medulloblastoma group. The need for differential rehabilitation strategies for specific clinical groups is remarked. The results are also discussed in the context of the Cerebellar Cognitive Affective Syndrome.
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OBJECTIVE. The main goal of this paper is to obtain a classification model based on feed-forward multilayer perceptrons in order to improve postpartum depression prediction during the 32 weeks after childbirth with a high sensitivity and specificity and to develop a tool to be integrated in a decision support system for clinicians. MATERIALS AND METHODS. Multilayer perceptrons were trained on data from 1397 women who had just given birth, from seven Spanish general hospitals, including clinical, environmental and genetic variables. A prospective cohort study was made just after delivery, at 8 weeks and at 32 weeks after delivery. The models were evaluated with the geometric mean of accuracies using a hold-out strategy. RESULTS. Multilayer perceptrons showed good performance (high sensitivity and specificity) as predictive models for postpartum depression. CONCLUSIONS. The use of these models in a decision support system can be clinically evaluated in future work. The analysis of the models by pruning leads to a qualitative interpretation of the influence of each variable in the interest of clinical protocols.
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Evidence shows that the endocannabinoid system modulates the addictive properties of nicotine. In the present study, we hypothesized that spontaneous withdrawal resulting from removal of chronically implanted transdermal nicotine patches is regulated by the endocannabinoid system. A 7-day nicotine dependence procedure (5.2 mg/rat/day) elicited occurrence of reliable nicotine abstinence symptoms in Wistar rats. Somatic and affective withdrawal signs were observed at 16 and 34 hours following removal of nicotine patches, respectively. Further behavioral manifestations including decrease in locomotor activity and increased weight gain also occurred during withdrawal. Expression of spontaneous nicotine withdrawal was accompanied by fluctuation in levels of the endocannabinoid anandamide (AEA) in several brain structures including the amygdala, the hippocampus, the hypothalamus and the prefrontal cortex. Conversely, levels of 2-arachidonoyl-sn-glycerol were not significantly altered. Pharmacological inhibition of fatty acid amide hydrolase (FAAH), the enzyme responsible for the intracellular degradation of AEA, by URB597 (0.1 and 0.3 mg/kg, i.p.), reduced withdrawal-induced anxiety as assessed by the elevated plus maze test and the shock-probe defensive burying paradigm, but did not prevent the occurrence of somatic signs. Together, the results indicate that pharmacological strategies aimed at enhancing endocannabinoid signaling may offer therapeutic advantages to treat the negative affective state produced by nicotine withdrawal, which is critical for the maintenance of tobacco use.
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An association between anorexia nerviosa (AN) and low bone mass has been demonstrated. Bone loss associated with AN involves hormonal and nutritional impairments, though their exact contribution is not clearly established. We compared bone mass in AN patients with women of similar weight with no criteria for AN, and a third group of healthy, normal-weight, age-matched women. The study included forty-eight patients with AN, twenty-two healthy eumenorrhoeic women with low weight (LW group; BMI < 18.5 kg/m2) and twenty healthy women with BMI >18.5 kg/m2 (control group), all of similar age. We measured lean body mass, percentage fat mass, total bone mineral content (BMC) and bone mineral density in lumbar spine (BMD LS) and in total (tBMD). We measured anthropometric parameters, leptin and growth hormone. The control group had greater tBMD and BMD LS than the other groups, with no differences between the AN and LW groups. No differences were found in tBMD, BMD LS and total BMC between the restrictive (n 25) and binge-purge type (n 23) in AN patients. In AN, minimum weight (P = 0.002) and percentage fat mass (P = 0.02) explained BMD LS variation (r2 0.48) and minimum weight (r2 0.42; P = 0.002) for tBMD in stepwise regression analyses. In the LW group, BMI explained BMD LS (r2 0.72; P = 0.01) and tBMD (r2 0.57; P = 0.04). We concluded that patients with AN had similar BMD to healthy thin women. Anthropometric parameters could contribute more significantly than oestrogen deficiency in the achievement of peak bone mass in AN patients.
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Alterations in motor functions are well-characterized features observed in humans and experimental animals subjected to thyroid hormone dysfunctions during development. Here we show that congenitally hypothyroid rats display hyperactivity in the adult life. This phenotype was associated with a decreased content of cannabinoid receptor type 1 (CB(1)) mRNA in the striatum and a reduction in the number of binding sites in both striatum and projection areas. These findings suggest that hyperactivity may be the consequence of a thyroid hormone deficiency-induced removal of the endocannabinoid tone, normally acting as a brake for hyperactivity at the basal ganglia. In agreement with the decrease in CB(1) receptor gene expression, a lower cannabinoid response, measured by biochemical, genetic and behavioral parameters, was observed in the hypothyroid animals. Finally, both CB(1) receptor gene expression and the biochemical and behavioral dysfunctions found in the hypothyroid animals were improved after a thyroid hormone replacement treatment. Thus, the present study suggests that impairment in the endocannabinoid system can underlay the hyperactive phenotype associated with hypothyroidism.
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The aim of this study was to analyze the sagittal spinal morphology of thoracic and lumbar spine in standing and sitting in women workers from a cooperative in the production, handling and marketing business of vegetable and fruit products. A total of 50 women (mean age: 43.62±8.43 years old) were evaluated. The Spinal Mouse system was used to mesasure the sagittal thoracic and lumbar curvatures in standing and relaxed sitting. The values for thoracic and lumbar curvatures were 32.74±8.76 and -21.66±19.12 in standing and 36.32±10.55 and -1.08±18.14 in sitting. A high frequency (86.0% and 68.3%) of normal thoracic kyphosis and lumbar lordosis were found in standing posture. While sitting the 74.0% and 20.0% presented thoracic hyperkyphosis and lumbar kyphosis. In conclusion, a high percentaje of women workers presented normality values in standing posture, although a high percentage of women were found with thoracic hyperkyphosis and lumbar flexed while sitting relaxed. It is recommended that these women carry out a program to improve their actitudinal postures in their work place.
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Knowledge on the patterns of repetition amongst individuals who develop language deficits in association with right hemisphere lesions (crossed aphasia) is very limited. Available data indicate that repetition in some crossed aphasics experiencing phonological processing deficits is not heavily influenced by lexical-semantic variables (lexicality, imageability, and frequency) as is regularly reported in phonologically-impaired cases with left hemisphere damage. Moreover, in view of the fact that crossed aphasia is rare, information on the role of right cortical areas and white matter tracts underpinning language repetition deficits is scarce. In this study, repetition performance was assessed in two patients with crossed conduction aphasia and striatal/capsular vascular lesions encompassing the right arcuate fasciculus (AF) and inferior frontal-occipital fasciculus (IFOF), the temporal stem and the white matter underneath the supramarginal gyrus. Both patients showed lexicality effects repeating better words than non-words, but manipulation of other lexical-semantic variables exerted less influence on repetition performance. Imageability and frequency effects, production of meaning-based paraphrases during sentence repetition, or better performance on repeating novel sentences than overlearned clichés were hardly ever observed in these two patients. In one patient, diffusion tensor imaging disclosed damage to the right long direct segment of the AF and IFOF with relative sparing of the anterior indirect and posterior segments of the AF, together with fully developed left perisylvian white matter pathways. These findings suggest that striatal/capsular lesions extending into the right AF and IFOF in some individuals with right hemisphere language dominance are associated with atypical repetition patterns which might reflect reduced interactions between phonological and lexical-semantic processes.
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Growing awareness of cerebellar involvement in addiction is based on the cerebellum's intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] and the gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-arachidonylglycerol (2-AG) production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and glutamate systems. Repeated cocaine results in normalization of glutamate receptor expression, although sustained changes in eCB is observed. We suggest that cocaine-induced alterations to cerebellar eCB should be considered when analyzing the adaptations imposed by psychostimulants that lead to addiction.
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BACKGROUND Lower limb amputees exhibit postural control deficits during standing which can affect their walking ability. OBJECTIVES The primary purpose of the present study was to analyze the thorax, pelvis, and hip kinematics and the hip internal moment in the frontal plane during gait in subjects with Unilateral Transtibial Amputation (UTA). METHOD The participants included 25 people with UTA and 25 non-amputees as control subjects. Gait analysis was performed using the Vicon(r) Motion System. We analyzed the motion of the thorax, pelvis, and hip (kinematics) as well as the hip internal moment in the frontal plane. RESULTS The second peak of the hip abductor moment was significantly lower on the prosthetic side than on the sound side (p=.01) and the control side (right: p=.01; left: p=.01). During middle stance, the opposite side of the pelvis was higher on the prosthetic side compared to the control side (right: p=.01: left: p=.01). CONCLUSIONS The joint internal moment at the hip in the frontal plane was lower on the prosthetic side than on the sound side or the control side. Thorax and pelvis kinematics were altered during the stance phase on the prosthetic side, presumably because there are mechanisms which affect postural control during walking.
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The role of lysophosphatidic acid (LPA) in the control of emotional behavior remains to be determined. We analyzed the effects of the central administration of 1-oleoyl-LPA (LPA 18∶1) in rats tested for food consumption and anxiety-like and depression-like behaviors. For this purpose, the elevated plus-maze, open field, Y maze, forced swimming and food intake tests were performed. In addition, c-Fos expression in the dorsal periaqueductal gray matter (DPAG) was also determined. The results revealed that the administration of LPA 18∶1 reduced the time in the open arms of the elevated plus-maze and induced hypolocomotion in the open field, suggesting an anxiogenic-like phenotype. Interestingly, these effects were present following LPA 18∶1 infusion under conditions of novelty but not under habituation conditions. In the forced swimming test, the administration of LPA 18∶1 dose-dependently increased depression-like behavior, as evaluated according to immobility time. LPA treatment induced no effects on feeding. However, the immunohistochemical analysis revealed that LPA 18∶1 increased c-Fos expression in the DPAG. The abundant expression of the LPA1 receptor, one of the main targets for LPA 18∶1, was detected in this brain area, which participates in the control of emotional behavior, using immunocytochemistry. These findings indicate that LPA is a relevant transmitter potentially involved in normal and pathological emotional responses, including anxiety and depression.
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Background. Hamstring injuries continue to affect active individuals and although inadequate muscle extensibility remains a commonly accepted factor, little is known about the most effective method to improve flexibility. Purpose. To determine if an isolated neurodynamic sciatic sliding technique would improve hamstring flexibility to a greater degree than stretching or a placebo intervention in asymptomatic subjects with short hamstring syndrome (SHS). Study Design. Randomized double-blinded controlled trial. Methods. One hundred and twenty subjects with SHS were randomized to 1 of 3 groups: neurodynamic sliding, hamstring stretching, and placebo control. Each subject's dominant leg was measured for straight leg raise (SLR) range of motion (ROM) before and after interventions. Data were analyzed with a 3 × 2 mixed model ANOVA followed by simple main effects analyses. Results. At the end of the study, more ROM was observed in the Neurodynamic and Stretching groups compared to the Control group and more ROM in the Neurodynamic group compared to Stretching group. Conclusion. Findings suggest that a neurodynamic sliding technique will increase hamstring flexibility to a greater degree than static hamstring stretching in healthy subjects with SHS. Clinical Relevance. The use of neurodynamic sliding techniques to improve hamstring flexibility in sports may lead to a decreased incidence in injuries; however, this needs to be formally tested.
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INTRODUCTION: Alterations in lipid metabolism and bone mineral metabolism disturbances are common disorders among renal transplant patients, contributing to the apparition of oxidative metabolic and cardiovascular diseases that threaten the integrity of the graft. AIMS: Describe and observe the evolution of alterations in bone mineral density (BMD) and lipid abnormalities in a population of kidney transplant patients. MATERIAL AND METHOD: The samples consisted of 119 kidney transplant patients of both sexes, measurements were performed pretransplant and posttransplant for five years of biochemical parameters, anthropometric measurements and measurement of bone mineral density at the lumbar spine, femur and radioulnar. RESULTS: During the five years after transplantation a significant increase in biochemical parameters, BMI, dyslipidemia, diabetes and hypertension occurs. At six months there is a high percentage of patients with pathologic BMD increase by 4.1% per year of transplantation. CONCLUSIONS: After kidney transplantation, a large increase of hyperlipidemia associated with a characteristic pattern of altered lipid with elevated total cholesterol, low density lipoprotein, high density lipoprotein, and the resulting increase in triglycerides, occurs despite statin therapy, leading to an increase in risk factors for diabetes, hypertension, diseases and cardiovascualres further loss of bone mass which carries a high risk of serious fractures occurs, threatening kidney graft and quality of life of patients.
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Vestibular migraine (VM) is a common disorder in which genetic, epigenetic, and environmental factors probably contribute to its development. The pathophysiology of VM is unknown; nevertheless in the last few years, several studies are contributing to understand the neurophysiological pathways involved in VM. The current hypotheses are mostly based on the knowledge of migraine itself. The evidence of trigeminal innervation of the labyrinth vessels and the localization of vasoactive neuropeptides in the perivascular afferent terminals of these trigeminal fibers support the involvement of the trigemino-vascular system. The neurogenic inflammation triggered by activation of the trigeminal-vestibulocochlear reflex, with the subsequent inner ear plasma protein extravasation and the release of inflammatory mediators, can contribute to a sustained activation and sensitization of the trigeminal primary afferent neurons explaining VM symptoms. The reciprocal connections between brainstem vestibular nuclei and the structures that modulate trigeminal nociceptive inputs (rostral ventromedial medulla, ventrolateral periaqueductal gray, locus coeruleus, and nucleus raphe magnus) are critical to understand the pathophysiology of VM. Although cortical spreading depression can affect cortical areas involved in processing vestibular information, functional neuroimaging techniques suggest a dysmodulation in the multimodal sensory integration and processing of vestibular and nociceptive information, resulting from a vestibulo-thalamo-cortical dysfunction, as the pathogenic mechanism underlying VM. The elevated prevalence of VM suggests that multiple functional variants may confer a genetic susceptibility leading to a dysregulation of excitatory-inhibitory balance in brain structures involved in the processing of sensory information, vestibular inputs, and pain. The interactions among several functional and structural neural networks could explain the pathogenic mechanisms of VM.
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Symptomatic arachnoiditis after posterior fossa surgical procedures such as decompression of Chiari malformation is a possible complication. Clinical presentation is generally insidious and delayed by months or years. It causes disturbances in the normal flow of cerebrospinal fluid and enlargement of a syrinx cavity in the upper spinal cord. Surgical de-tethering has favorable results with progressive collapse of the syrinx and relief of the associated symptoms. Case Description: A 30-year-old male with Chiari malformation type I was treated by performing posterior fossa bone decompression, dura opening and closure with a suturable bovine pericardium dural graft. Postoperative period was uneventful until the fifth day in which the patient suffered intense headache and progressive loose of consciousness caused by an acute posterior fossa epidural hematoma. It was quickly removed with complete clinical recovering. One year later, the patient experienced progressive worsened of his symptoms. Upper spinal cord tethering was diagnosed and a new surgery for debridement was required. Conclusions: The epidural hematoma compressing the dural graft against the neural structures contributes to the upper spinal cord tethering and represents a nondescribed cause of postoperative fibrosis, adhesion formation, and subsequent recurrent hindbrain compression.