Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0241981 (loss of balance)
 452 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Orthostatic hypotension is a decrease in systolic blood pressure of more than 20 mm Hg or a decrease in diastolic blood pressure of at least 10 mm Hg, within 3 minutes of changing from a supine to an upright position. The typical clinical presentation of orthostatic hypotension includes dizziness, syncope, blurry vision and loss of balance. Symptoms may be more frequent in women, but the complicating roles played by comorbid factors and the estrogen mechanisms are not well understood. Women have a more active parasympathetic system, higher estrogen levels and a lower center of gravity. Thus, women less effectively compensate for the drop of blood pressure in response to positional change. An understanding of these mechanisms contributing to orthostatic hypotension may improve diagnosis and treatment of the problem.
Am J Med Sci 2011 Sep
PMID:Gender differences in orthostatic hypotension. 2128 99

Loss of balance is often due to loss of vestibular hair cells. In mammals, regeneration of functional hair cells in the mature sensory epithelium is limited; therefore, loss of sensory cells can lead to debilitating balance problems. Delivery of the transcription factor atonal (atoh1) after aminoglycoside ototoxicity has previously been shown to induce the transdifferentiation of supporting cells into new hair cells and restore function. A problem with mouse aminoglycoside models is that the partial loss of hair cells seen in human disease is difficult to establish consistently. To more closely mirror human clinical balance dysfunction, we have used systemic application of 3,3'-iminodipropionitrile (IDPN), a vestibulotoxic nitrile compound known to cause vestibular hair cell loss, to induce a consistent partial loss of vestibular hair cells. To determine if balance function could be restored, we delivered atoh1 using a new adenovirus vector, based on Ad28. The Ad28 adenovector is based on a human serotype with a low seroprevalence that appears to target gene delivery to vestibular supporting cells. To further provide cell type selectivity of gene delivery, we expressed atoh1 using the supporting cell-specific glial fibrillary acid protein promoter. Delivery of this vector to IDPN-damaged vestibular organs resulted in a significant recovery of vestibular hair cells and restoration of balance, as measured by time on rotarod compared with untreated controls.
Gene Ther 2011 Sep
PMID:Selective atonal gene delivery improves balance function in a mouse model of vestibular disease. 2147 6

The aim of this study is to characterize the changes of CD4(+) CD25(high) forkhead box P3 (FoxP3(+) ) regulatory T cells (T(reg) ), interleukin (IL)-17 secreting T helper type 17 (Th17) cell frequencies and the balance of these two subsets in a cohort of chronic human immunodeficiency virus type 1 (HIV-1)-infected patients in China. A total of 115 untreated chronic HIV-infected individuals and 32 healthy donors were recruited in this study. Peripheral blood mononuclear cells were isolated from ethylenediamine tetracetic acid (EDTA) anti-coagulated fresh whole blood and stained to characterize the frequencies of T(reg) and Th17. Of a total 115 patients, 42 individuals including 10 elite controllers were followed-up for more than 1 year, and changes of T(reg) and Th17 frequencies were analysed over time. The continuous loss of Th17 cells was accompanied by a concomitant rise in the frequency of T(reg) cells, resulting in a loss of Th17/T(reg) balance during the progressive HIV infection. Meanwhile, the T(reg) levels, Th17 levels and Th17/T(reg) ratios of the elite controller group were comparable to those of the HIV-1 negative controls in the follow-up study. Additionally, we demonstrated that loss of balance between Th17 and T(reg) is associated with an earlier CD4 T cell decline during the course of HIV infection. Our results indicate that a loss of immune-balance of Th17 to T(reg) during HIV-1 disease progression and the persistence of such an immune-balance in the elite controllers may have a critical role in HIV-1 infection and further shed new light into understanding the pathogenesis of HIV-1.
Clin Exp Immunol 2011 Sep
PMID:Loss of balance between T helper type 17 and regulatory T cells in chronic human immunodeficiency virus infection. 2170 92

This focus group, qualitative study (N = 18) reports the psychosocial impact, specifically, of spasticity symptoms on a sample of people with MS (multiple sclerosis). MS, a chronic disabling disease which attacks the central nervous system, currently affects about 100,000 people in the UK and estimates indicate that worldwide prevalence varies from around 10 to 250 per 100,000. The cause remains unknown and the rate of disease progression varies among individuals. The disease of MS itself has a severe impact on psychological well-being and quality of life. However, there is little evidence about the additional impact of the spasticity-related symptoms, which include involuntary muscle contractions, loss of dexterity, loss of balance, incontinence and pain. These are shown here to lead to further distress and embarrassment and to have a detrimental influence on emotional and social relationships.
J Health Psychol 2001 Sep
PMID:The psychosocial impact of spasticityrelated problems for people with multiple sclerosis: a focus group study. 2204 53

Cancer cachexia is a highly debilitating paraneoplastic disease observed in more than 50% of patients with advanced cancers and directly contributes to 20% of cancer deaths. Skeletal muscle wasting is a prominent feature of the disease and is believed to result from the loss of balance between protein synthesis and degradation. Quality of life and prognosis are severely compromised in patients with cancer cachexia. Despite current knowledge on the mediators involved in cancer cachexia, treatment targeting a single molecule has rendered limited effectiveness. This article aims to review the mediators of cancer cachexia and interventions attempted in the literature and discuss the common pathways leading to protein loss that these mediators modulate during cachexia. We believe that by targeting downstream effectors that are common in these pathways, a better therapeutic approach to reverse muscle wasting and maintain muscle function during cancer cachexia will be achieved.
Endocr Metab Immune Disord Drug Targets 2012 Sep
PMID:Cancer cachexia: molecular targets and pathways for diagnosis and drug intervention. 2238 13

Postural control deficits are associated with increased risk of loss of balance and potential injury. To assess balance deficits and estimate injury risk, there is a need to evaluate postural control during dynamic activities. Analysis during dynamic activities could assess if an individual's ability to control their posture is a fixed condition or if it is dependent on the demands of a task. The purpose of this study was to evaluate changes in postural control during a dynamic lower extremity task using time-to-contact (TtC) analysis. 3D motion capture with a force plate was used to evaluate 46 healthy recreational athletes performing an anterior reach with the right foot while standing on their left leg. TtC was calculated for nine valid trials. For each trial, the time from the toe leaving the force plate to the toe touching the floor at the maximum reach distance was divided into five epochs of equal duration. TtC was averaged over each epoch. Differences in TtC were evaluated with an unbalanced mixed effects ANOVA and post hoc Tukey's HSD comparisons. Epoch was a significant main effect (p<0.001), with both Epoch 4 and Epoch 5 having significantly greater TtC from all other epochs (p=0.05). Increasing TtC in later epochs suggests a higher demand for postural control when the task becomes more challenging. As an individual's reaching foot extends further from the body, postural control is adjusted to match the changing demands of the dynamic task.
Gait Posture 2013 Sep
PMID:Time-to-contact demonstrates modulation of postural control during a dynamic lower extremity task. 2352 69

Reactive postural control, the ability to recover from an external perturbation to stability, ultimately determines whether an individual will fall following a loss of balance and should be routinely incorporated in balance assessment. The purpose of this study was to identify (1) methods used to assess reactive postural control in clinical practice and (2) factors associated with regular assessment of reactive postural control. A cross-sectional survey was conducted. Three hundred and fifty-seven physiotherapists in Ontario, Canada who treated adults with balance impairments answered questions about the components of balance they assess and how they assess reactive control in their practice. Of the 273 respondents who assessed reactive postural control at least some of the time, 15.4% used a standardized measure, 79.1% used a non-standardized approach, and 5.5% used both. Forty-five methods of assessing reactive control were reported. The most common methods used were non-standardized perturbations (43.5%; 104/239 respondents) and movement observation (18.8%; 45/239). The remaining 43 methods were each used by less than 8% of respondents. Practice area had the strongest association with regular assessment of reactive postural control (>60% of the time), and respondents working with neurological disorders were more likely to regularly evaluate reactive control than those working with people with orthopedic conditions. Despite the availability of valid standardized measures to evaluate reactive postural control, respondents relied primarily on non-standardized approaches and observational assessment. Future work should examine the factors influencing choice of reactive control assessment tools and awareness of standardized measures for reactive postural control.
Gait Posture 2013 Sep
PMID:Clinical assessment of reactive postural control among physiotherapists in Ontario, Canada. 2381 87

It is well known that the cerebellum is important for movement control and plays a critical role in balance and locomotion. As such, one of the most characteristic and sensitive signs of cerebellar damage is gait ataxia. However, characterizing ataxic gait is no easy task, because gait patterns are highly variable. This variability seems to result from the interaction of different factors, namely, (1) the primary motor deficits in balance control and multi-joint coordination and oculomotor dysfunction, (2) the safety strategies used, and (3) inaccurate adjustments in patients with loss of balance. In this report, we review different approaches to analyzing ataxic gait and studies to identify and quantify the different factors contributing to this movement disorder. We also discuss the influence of the cerebellum in adaptive locomotor control, the interaction between cognitive load and gait in dual-task paradigms, and the recent advances in rehabilitation of gait and posture for patients with cerebellar degeneration. In the second part, we discuss open questions concerning cerebellar mechanisms in multi-joint coordination during different walking conditions. Furthermore, we point out potential future directions in motor rehabilitation, with the objective of identifying predictors of rehabilitation outcome and the development of individualized training programs that potentially involve rehabilitation technology.
Mov Disord 2013 Sep 15
PMID:Gait ataxia--specific cerebellar influences and their rehabilitation. 2413 45

Cerebellar dysfunction causes ataxia characterized by loss of balance and coordination. Until now, the molecular and neuronal mechanisms of several types of inherited cerebellar ataxia have not been completely clarified. Here, we report that leucine-rich G protein-coupled receptor 4 (Lgr4/Gpr48) is highly expressed in Purkinje cells (PCs) in the cerebellum. Deficiency of Lgr4 leads to an ataxia-like phenotype in mice. Histologically, no obvious morphological changes were observed in the cerebellum of Lgr4 mutant mice. However, the number of PCs was slightly but significantly reduced in Lgr4(-/-) mice. In addition, in vitro electrophysiological analysis showed an impaired long term depression (LTD) at parallel fiber-PC (PF-PC) synapses in Lgr4(-/-) mice. Consistently, immunostaining experiments showed that the level of phosphorylated cAMP-responsive element-binding protein (Creb) was significantly decreased in Lgr4(-/-) PCs. Furthermore, treatment with forskolin, an adenylyl cyclase agonist, rescued phospho-Creb in PCs and reversed the impairment in PF-PC LTD in Lgr4(-/-) cerebellar slices, indicating that Lgr4 is an upstream regulator of Creb signaling, which is underlying PF-PC LTD. Together, our findings demonstrate for first time an important role for Lgr4 in motor coordination and cerebellar synaptic plasticity and provide a potential therapeutic target for certain types of inherited cerebellar ataxia.
J Biol Chem 2014 Sep 19
PMID:Lgr4 protein deficiency induces ataxia-like phenotype in mice and impairs long term depression at cerebellar parallel fiber-Purkinje cell synapses. 2506 12

Although considerable arm movements have been observed at loss of balance, research on standing balance focused primarily on the ankle and hip strategies. This study aimed to investigate the effect of arm motion on feet-in-place balance recovery. Participants stood on a single force plate and leaned forward with a straight body posture. They were then released from three forward-lean angles and regained balance without moving their forefeet under arm-swing (AS) and arm-constrained (AC) conditions. Higher success rates and shorter recovery times were found with arm motion under moderate balance perturbations. Recovery time was significantly correlated with peak linear momentum of the arms. Circumduction arm motion caused initial shoulder extension (backward arm movement) to generate reaction forces to pull the body forward, but later forward linear momentum of the arms helped move the whole body backward to avoid forward falling. However, greater lean angles increased difficulty in balance recovery, making the influences of the arms less significant. Since arm motions were observed in all participants with significantly enhanced performance under moderate balance perturbation, it was concluded that moving the arms should also be considered (together with the ankles and hips) as an effective strategy for balance recovery.
J Biomech 2015 Sep 18
PMID:Role of arm motion in feet-in-place balance recovery. 2620 86


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