986 resultados para Withdrawal


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BACKGROUND Psychomotor disturbances are a main clinical feature of major depressive disorder (MDD) but little is known about their EEG signature. One of the most replicated EEG findings in MDD is resting frontal asymmetry in the alpha band (FAA), which is thought to be a correlate of withdrawal behavior and reduced approach motivation. The purpose of this study was to assess psychomotor alterations, alpha band power, FAA and investigate the association between them. METHODS 20 MDD patients and 19 healthy subjects were enrolled. Alpha power and FAA scores were calculated from a resting state EEG. Wrist actigraphy was recorded from the non-dominant arm for 24 h and activity level scores (AL) were extrapolated from the wakeful periods. RESULTS MDD patients had a left-lateralized frontal alpha activity and lower AL scores when compared to healthy subjects. A significant correlation was found between mean FAA and AL scores. A negative covariance between power in the lower alpha range and AL scores over the motor cortex bilaterally was detected. LIMITATIONS Relatively small sample size. Patients were pharmacologically treated with antidepressants. CONCLUSIONS This study replicates the finding of left-lateralized FAA and lower AL scores in MDD patients, and establishes the first evidence of significant correlations between alpha power, FAA scores and measures of motor activity, which may be interpreted as an expression of impaired motivational drive in MDD.

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AIM Despite the large scientific debate concerning potential stigmatizing effects of identifying an individual as being in an at-risk mental state (ARMS) for psychosis, studies investigating this topic from the subjective perspective of patients are rare. This study assesses whether ARMS individuals experience stigmatization and to what extent being informed about the ARMS is experienced as helpful or harmful. METHODS Eleven ARMS individuals, currently participating in the follow-up assessments of the prospective Basel Früherkennung von Psychosen (FePsy; English: Early Detection of Psychosis) study, were interviewed in detail using a semistructured qualitative interview developed for this purpose. Data were analysed using Interpretative Phenomenological Analysis. RESULTS Most individuals experiencing first symptoms reported sensing that there was 'something wrong with them' and felt in need of help. They were relieved that a specific term was assigned to their symptoms. The support received from the early detection centre was generally experienced as helpful. Many patients reported stigmatization and discrimination that appeared to be the result of altered behaviour and social withdrawal due to the prepsychotic symptoms they experienced prior to contact with the early detection clinic. CONCLUSIONS The results suggest that early detection services help individuals cope with symptoms and potential stigmatization rather than enhancing or causing the latter. More emphasis should be put on the subjective experiences of those concerned when debating the advantages and disadvantages of early detection with regard to stigma. There was no evidence for increased perceived stigma and discrimination as a result of receiving information about the ARMS.

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Frontal alpha band asymmetry (FAA) is a marker of altered reward processing in major depressive disorder (MDD), associated with reduced approach behavior and withdrawal. However, its association with brain metabolism remains unclear. The aim of this study is to investigate FAA and its correlation with resting – state cerebral blood flow (rCBF). We hypothesized an association of FAA with regional rCBF in brain regions relevant for reward processing and motivated behavior, such as the striatum. We enrolled 20 patients and 19 healthy subjects. FAA scores and rCBF were quantified with the use of EEG and arterial spin labeling. Correlations of the two were evaluated, as well as the association with FAA and psychometric assessments of motivated behavior and anhedonia. Patients showed a left – lateralized pattern of frontal alpha activity and a correlation of FAA lateralization with subscores of Hamilton Depression Rating Scale linked to motivated behavior. An association of rCBF and FAA scores was found in clusters in the dorsolateral prefrontal cortex bilaterally (patients) and in the left medial frontal gyrus, in the right caudate head and in the right inferior parietal lobule (whole group). No correlations were found in healthy controls. Higher inhibitory right – lateralized alpha power was associated with lower rCBF values in prefrontal and striatal regions, predominantly in the right hemisphere, which are involved in the processing of motivated behavior and reward. Inhibitory brain activity in the reward system may contribute to some of the motivational problems observed in MDD.

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Objective: Limited research exists on internal risk processes in suicide attempters and factors that distinguish them from non-suicidal, depressive individuals. In this qualitative study, we investigated Plans, motives, and underlying self-regulatory processes of the two groups and conducted a comparative analysis. Methods: We analyzed narrative interviews of 17 suicide attempters and intake interviews of 17 non-suicidal, depressive patients using Plan Analysis. Then, we developed a prototypical Plan structure for both groups. Results: Suicidal behavior serves various Plans only found in suicide attempters. Plans of this group are especially related to social perfectionism and withdrawal in order to protect their self-esteem. Depressive patients employ several interpersonal control and coping strategies, which might help prevent suicidal behavior. Conclusion: The prototypical Plan structure of suicide attempters may be a valuable tool for clinicians to detect critical Plans and motives in their interaction with patients, which are related to suicide risk.

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BACKGROUND High-dose benzodiazepine dependence constitutes a major clinical concern. Although withdrawal treatment is recommended, it is unsuccessful for a significant proportion of affected patients. More recently, a benzodiazepine maintenance approach has been suggested as an alternative for patients' failing discontinuation treatment. While there is some data supporting its effectiveness, patients' perceptions of such an intervention have not been investigated. METHODS An exploratory qualitative study was conducted among a sample of 41 high-dose benzodiazepine (BZD)-dependent patients, with long-term use defined as doses equivalent to more than 40 mg diazepam per day and/or otherwise problematic use, such as mixing substances, dose escalation, recreational use, or obtainment by illegal means. A qualitative content analysis approach was used to evaluate findings. RESULTS Participants generally favored a treatment discontinuation approach with abstinence from BZD as its ultimate aim, despite repeated failed attempts at withdrawal. A maintenance treatment approach with continued prescription of a slow-onset, long-acting agonist was viewed ambivalently, with responses ranging from positive and welcoming to rejection. Three overlapping themes of maintenance treatment were identified: "Only if I can try to discontinue…and please don't call it that," "More stability and less criminal activity…and that is why I would try it," and "No cure, no brain and no flash…and thus, just for everybody else!" CONCLUSIONS Some patients experienced slow-onset, long-acting BZDs as having stabilized their symptoms and viewed these BZDs as having helped avoid uncontrolled withdrawal and abstain from criminal activity. We therefore encourage clinicians to consider treatment alternatives if discontinuation strategies fail.

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OBJECTIVE To determine a dexmedetomidine concentration, to be added to an alfaxalone-based bath solution, that will enhance the anaesthetic and analgesic effects of alfaxalone; and to compare the quality of anaesthesia and analgesia provided by immersion with either alfaxalone alone or alfaxalone with dexmedetomidine in oriental fire-bellied toads (Bombina orientalis). STUDY DESIGN Pilot study followed by a prospective, randomized, experimental trial. ANIMALS Fourteen oriental fire-bellied toads. METHODS The pilot study aimed to identify a useful dexmedetomidine concentration to be added to an anaesthetic bath containing 20 mg 100 mL(-1) alfaxalone. Thereafter, the toads were assigned to one of two groups, each comprising eight animals, to be administered either alfaxalone (group A) or alfaxalone-dexmedetomidine (group AD). After immersion for 20 minutes, the toads were removed from the anaesthetic bath and the righting, myotactic and nociceptive reflexes, cardiopulmonary variables and von Frey filaments threshold were measured at 5 minute intervals and compared statistically between groups. Side effects and complications were noted and recorded. RESULTS In the pilot study, a dexmedetomidine concentration of 0.3 mg 100 mL(-1) added to the alfaxalone-based solution resulted in surgical anaesthesia. The toads in group AD showed higher von Frey thresholds and lower nociceptive withdrawal reflex scores than those in group A. However, in group AD, surgical anaesthesia was observed in two out of eight toads only, and induction of anaesthesia was achieved in only 50% of the animals, as compared with 100% of the toads in group A. CONCLUSIONS AND CLINICAL RELEVANCE The addition of dexmedetomidine to an alfaxalone-based solution for immersion anaesthesia provided some analgesia in oriental fire-bellied toads, but failed to potentiate the level of unconsciousness and appeared to lighten the depth of anaesthesia. This limitation renders the combination unsuitable for anaesthetizing oriental fire-bellied toads for invasive procedures.

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Oriental fire-bellied toads (Bombina orientalis) are small semi-aquatic anuran species popular as both pets and laboratory animals. Although they are commonly anaesthetized to undergo clinical and experimental procedures, very little is known about their anaesthetic management. The aims of this prospective, randomized, cross-over experimental trial were to establish effective butorphanol and morphine concentrations to be added to alfaxalone for immersion anaesthesia (pilot study), and to compare the anaesthetic and antinociceptive effects of the two drug mixtures (alfaxalone-butorphanol and alfaxalone-morphine), in Bombina orientalis toads. For the actual trial, the toads were randomly assigned to one of two treatment groups: AB and AM, with seven animals in each group, which received alfaxalone-butorphanol and alfaxalone-morphine combinations, respectively, at the concentrations established during the pilot study. Heart rate, respiratory rate, von Frey filament threshold and response to nociceptive withdrawal (NWR), righting and myotactic reflexes were measured at 5 min intervals until return of righting reflex was observed. The investigator who carried out all the measurements was blinded to the treatment. Any undesired effect or complication was noted and recorded. The two treatments were found to be comparable in terms of onset and duration of anaesthesia, and occurrence of undesired effects. However, group AM resulted in lower NWR scores and higher von Frey filament thresholds than group AB. It is concluded that, at the investigated concentrations and in combination with alfaxalone by immersion, morphine provides better antinociception than butorphanol in oriental fire-bellied toads.

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Resistance to current chemo- and radiation therapy is the principal problem in anticancer treatment. Although intensively investigated, the therapeutic outcome is still far from satisfactory. Among the multiple factors which contribute to the drug resistance in cancer cells, the involvement of autophagy is becoming more and more evident. Autophagy describes a cellular self-digestion process, in which cytoplasmic elements can be selectively engulfed and finally degraded in autophagolysosomes to supply nutrients and building blocks for the cells. Autophagy controls cellular homeostasis and can be induced in response to stresses, like hypoxia and growth factor withdrawal. Since the essential physiological function of autophagy is to maintain cellular metabolic balance, dysregulated autophagy has been found associated with multiple diseases, including cancer. Interestingly, the role of autophagy in cancer is two-sided; it can be pro- or antitumor. Autophagy can suppress tumor formation, for example, by controlling cell proliferation and the production of reactive oxygen species. On the other hand, autophagy can provide nutrients to the tumor cells to support tumor growth under nutrition-limiting conditions, thereby promoting tumor development. This ambivalent behavior is also evident in anticancer therapy: By inducing autophagic cell death, autophagy has been shown to potentiate the cytotoxicity of chemotherapeutic drugs, but autophagy has also been linked to drug resistance, since inhibiting autophagy has been found to sensitize tumor cells toward anticancer drug-induced cell death. In this chapter, we will focus on the dual role of autophagy in tumorigenesis and chemotherapy, will classify autophagy inducers and inhibitors used in anticancer treatment, and will discuss topics related to future drug development which have arisen.

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AIMS γ-Hydroxybutyrate (GHB) is used as a treatment for narcolepsy and alcohol withdrawal and as recreational substance. Nevertheless, there are limited data on the pharmacokinetics and pharmacokinetic-pharmacodynamic relationship of GHB in humans. We characterized the pharmacokinetic profile and exposure-psychotropic effect relationship of GHB in humans. METHODS Two oral doses of GHB (25 and 35 mg/kg) were administered to 32 healthy male subjects (16 for each dose) using a randomized, placebo-controlled, cross-over design. RESULTS Maximal concentrations of GHB were (geometric mean and 95%CI): 218 (176-270) nmol/ml and 453 (374-549) nmol/ml for the 25 and 35 mg/kg GHB doses, respectively. The elimination half-lives (mean ± SD) were 36 ± 9 and 39 ± 7 min and the AUC∞ values (geometric mean and 95%CI) were 15,747 (12,854-19,290) and 40,113 (33,093-48,622) nmol∙min/ml for the 20 and 35 mg/kg GHB doses, respectively. Thus, plasma GHB exposure (AUC0-∞ ) rose disproportionally (+40%) with the higher dose. γ-Hydroxybutyrate produced mixed stimulant-sedative effects, with a dose-dependent increase in sedation and dizziness. It did not alter heart rate or blood pressure. A close relationship between plasma GHB exposure and its psychotropic effects was found, with higher GHB concentrations associated with higher subjective stimulation, sedation, and dizziness. No clockwise hysteresis was observed in the GHB concentration effect plot over time (i.e., no acute pharmacological tolerance). CONCLUSION Evidence was found of a non-linear dose-exposure relationship (i.e., no dose proportionality) at moderate doses of GHB. The effects of GHB on consciousness were closely linked to its plasma exposure and exhibited no acute tolerance. This article is protected by copyright. All rights reserved.

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Hypersensitivity of pain pathways is considered a relevant determinant of symptoms in chronic pain patients, but data on its prevalence are very limited. To our knowledge, no data on the prevalence of spinal nociceptive hypersensitivity are available. We studied the prevalence of pain hypersensitivity and spinal nociceptive hypersensitivity in 961 consecutive patients with various chronic pain conditions. Pain threshold and nociceptive withdrawal reflex threshold to electrical stimulation were used to assess pain hypersensitivity and spinal nociceptive hypersensitivity, respectively. Using 10th percentile cutoff of previously determined reference values, the prevalence of pain hypersensitivity and spinal nociceptive hypersensitivity (95% confidence interval) was 71.2 (68.3-74.0) and 80.0 (77.0-82.6), respectively. As a secondary aim, we analyzed demographic, psychosocial, and clinical characteristics as factors potentially associated with pain hypersensitivity and spinal nociceptive hypersensitivity using logistic regression models. Both hypersensitivity parameters were unaffected by most factors analyzed. Depression, catastrophizing, pain-related sleep interference, and average pain intensity were significantly associated with hypersensitivity. However, none of them was significant for both unadjusted and adjusted analyses. Furthermore, the odds ratios were very low, indicating modest quantitative impact. To our knowledge, this is the largest prevalence study on central hypersensitivity and the first one on the prevalence of spinal nociceptive hypersensitivity in chronic pain patients. The results revealed an impressively high prevalence, supporting a high clinical relevance of this phenomenon. Electrical pain thresholds and nociceptive withdrawal reflex explore aspects of pain processing that are mostly independent of sociodemographic, psychological, and clinical pain-related characteristics.

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The deformation behavior of atomically clean, nanometer sized tungsten / gold contacts was studied at room temperature in ultra-high vacuum. An instrument that combines atomic force microscopy (AFM), scanning tunneling microscopy (STM), and field ion microscopy (FIM) into a single experimental apparatus was designed, constructed, and calibrated. A cross-hair force sensor having a spring constant of - 442 N/m was developed and its motion was monitored during indentation experiments with a differential interferometer. Tungsten tips of controlled size (12.8 nm < tip radius < 2 1.6 nm) were first shaped and characterized using FIM and then indented into a Au (1 10) single crystal to depths ranging from 1.5 nrn to 18 nm using the force sensor. Continuum mechanics models were found to be valid in predicting elastic deformation during initial contact and plastic zone depths despite our small size regime. Multiple discrete yielding events lasting < 1.5 ms were observed during the plastic deformation regime; at the yield points a maximum value for the principal shear stress was measured to be 5 + 1 GPa. During tip withdrawal, "pop-out" events relating to material relaxation within the contact were observed. Adhesion between the tip and sample led to experimental signatures that suggest neck formation prior to the break of contact. STM images of indentation holes revealed various shapes that can be attributed to the (1 1 1 ) (1 10) crystallographic slip system in gold. FIM images of the tip after indentation showed no evidence of tip damage

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Transforming growth factor beta-1 (TGF-β1) is a cytokine and neurotrophic factor whose neuromodulatory effects in Aplysia californica were recently described. Previous results demonstrated that TGF-β1 induces long-term increases in the efficacy of sensorimotor synapses, a neural correlate of sensitization of the defensive tail withdrawal reflex. These results provided the first evidence that a neurotrophic factor regulates neuronal plasticity associated with a simple form of learning in Aplysia, and raised many questions regarding the nature of the modulation. No homologs of TGF-β had previously been identified in Aplysia, and thus, it was not known whether components of TGF-β1 signaling pathways were present in Aplysia. Furthermore, the signaling mechanisms engaged by TGF-β1 had not been identified, and it was not known whether TGF-β1 regulated other aspects of neuronal function.^ The present investigation into the actions of TGF-β1 was initiated by examining the distribution of the type II TGF-β1 receptor, the ligand binding receptor. The receptor was widely distributed in the CNS and most neurons exhibited somatic and neuritic immunoreactivity. In addition, the ability of TGF-β1 to activate the cAMP/PKA and MAPK pathways, known to regulate several important aspects of neuronal function, was examined. TGF-β1 acutely decreased cAMP levels in sensory neurons, activated MAPK and triggered translocation of MAPK to the nucleus. MAPK activation was critical for both short- and long-term regulation of neuronal function by TGF-β1. TGF-β1 acutely decreased synaptic depression induced by low frequency stimuli in a MAPK-dependent manner. This regulation may result, at least in part, from the modulation of synapsin, a major peripheral synaptic vesicle protein. TGF-β1 stimulated MAPK-dependent phosphorylation of synapsin, a process believed to regulate synaptic vesicle mobilization from reserve to readily-releasable pools of neurotransmitter. In addition to its acute effect on synaptic efficacy, TGF-β1 also induced long-term increases in sensory neuron excitability. Whereas transient exposure to TGF-β1 was not sufficient to drive short-or long-term changes in excitability, prolonged exposure to TGF-β1 induced long-term changes in excitability that depended on MAPK. The results of these studies represent significant progress toward an understanding of the role of TGF-β1 in neuronal plasticity. ^

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Our national focus and emphasis on the promotion of healthy behavior choices regarding tobacco and other drugs continues to target adolescents. Multiple studies have shown that adolescence is the optimum period for the prevention of substance use initiation as life-long patterns of health behaviors are established during this critical developmental stage. Tobacco use is associated with an increase in morbid and mortal health conditions of which prevalence increases throughout the lifespan. Attention to the antecedents of preventable health conditions aims to modify the risks and identify health promotion factors. Modifying antecedent factors for tobacco initiation in youth and identifying protective factors for successful smoking cessation has major public health implications across the lifespan. Of foremost interest are those risk factors and resultant behaviors that predict a youth's probability of initiating cigarette use and their cessation of cigarette use. Specifically, this dissertation supports previous results identifying intervention variables on the initiation/cessation continuum model especially with the established predictors of smoking (decisional balance and susceptibility) and with more recently identified predictors of smoking (nicotine dependence and withdrawal symptoms) in current and former smokers in a sample of high school students in Austin and Houston, Texas. These results offer insight for the development of appropriate intervention program strategies for our youth. ^

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Background. There is currently a push to increase the number of minorities in cancer clinical trials in an effort to reduce cancer health disparities. Overcoming barriers to clinical trial research for minorities is necessary if we are to achieve the goals of Healthy People 2010. To understand the unexpectedly high rate of attrition in the A NULIFE study, the research team examined the perceived barriers to participation among minority women. The purpose of this study was to determine if either personal or study-related factors influenced healthy pre-menopausal women aged 25-45 years to terminate their participation in the A NULIFE Study. We hypothesized that personal factors were the driving forces for attrition rates in the prevention trial.^ Methods. The target population consisted of eligible women who consented to the A NULIFE study but withdrew prior to being randomized (N= 46), as well as eligible women who completed the informed consent process for the A NULIFE study and withdrew after randomization (N= 42). Examination of attrition rates in this study occurred at a time point when 10 out of 12 participant groups had completed the A NULIFE study. Data involving the 2 groups that were actively engaged in study activities were not used in this analysis. A survey instrument was designed to query the personal and study-related factors that were believed to have contributed to the decision to terminate participation in the A NULIFE study.^ Results. Overall, the highest ranked personal reason that influenced withdrawal from the study was being “too busy” with other obligations. The second highest ranked factor for withdrawal was work obligations. Whereas, more than half of all participants agreed that they were well-informed about the study and considered the study personnel to be approachable, 54% of participants would have been inclined to remain in the study if it were located at a local community center.^ Conclusions. Time commitment was likely a major factor for withdrawal from the A NULIFE study. Future investigators should implement trials within participant communities where possible. Also, focus group settings may provide detailed insight into factors that contribute to the attrition of minorities in cancer clinical trials.^

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Patients living with a spinal cord injury (SCI) often develop chronic neuropathic pain (CNP). Unfortunately, the clinically approved, current standard of treatment, gabapentin, only provides temporary pain relief. This treatment can cause numerous adverse side effects that negatively affect the daily lives of SCI patients. There is a great need for alternative, effective treatments for SCI-dependent CNP. Minocycline, an FDA-approved antibiotic, has been widely prescribed for the treatment of acne for several decades. However, recent studies demonstrate that minocycline has neuroprotective properties in several pre-clinical rodent models of CNS trauma and disease. Pre-clinical studies also show that short-term minocycline treatment can prevent the onset of CNP when delivered during the acute stage of SCI and can also transiently attenuate established CNP when delivered briefly during the chronic stage of SCI. However, the potential to abolish or attenuate CNP via long-term administration of minocycline after SCI is unknown. The purpose of this study was to investigate the potential efficacy and safety of long-term administration of minocycline to abolish or attenuate CNP following SCI. A severe spinal contusion injury was administered on adult, male, Sprague-Dawley rats. At day 29 post-injury, I initiated a three-week treatment regimen of daily administration with minocycline (50 mg/kg), gabapentin (50 mg/kg) or saline. The minocycline treatment group demonstrated a significant reduction in below-level mechanical allodynia and above- level hyperalgesia while on their treatment regimen. After a ten-day washout period of minocycline, the animals continued to demonstrate a significant reduction in below-level mechanical allodynia and above-level hyperalgesia. However, minocycline-treated animals exhibited abnormal weight gain and hepatotoxicity compared to gapabentin-treated or vehicle-treated subjects.The results support previous findings that minocycline can attenuate CNP after SCI and suggested that minocycline can also attenuate CNP via long-term delivery of minocycline after SCI (36). The data also suggested that minocycline had a lasting effect at reducing pain symptoms. However, the adverse side effects of long-term use of minocycline should not be ignored in the rodent model. Gabapentin treatment caused a significant decrease in below-level mechanical allodynia and below-level hyperalgesia during the treatment regimen. Because gabapentin treatment has an analgesic effect at the concentration I administered, the results were expected. However, I also found that gabapentin-treated animals demonstrated a sustained reduction in pain ten days after treatment withdrawal. This result was unexpected because gabapentin has a short half-life of 1.7 hours in rodents and previous studies have demonstrated that pre-drug pain levels return shortly after withdrawal of treatment. Additionally, the gabapentin-treated animals demonstrated a significant and sustained increase in rearing events compared with all other treatment groups which suggested that gabapentin treatment was not only capable of reducing pain long-term but may also significantly improve trunk stability or improve motor function recovery.