PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Balance ability”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources
PubMed2005

Smelling renal dysfunction via electronic nose.

The human body odor plays an important role in social communication in various situations, like the olfactory identification of partners and relatives as well as in parents-child interactions. In patients with renal dysfunction the compound of sweat and volatile gases is changed because of the limited ability for removing metabolic products from the blood. The regulation of electrolyte composition and acid-base balance are also altered so that the body odor of these patients may be significantly influenced by these disorders. We show the ability of an electronic nose to detect changes in the human body odor in consequence of renal dysfunction by reducing multivariate sensor signals with principal component analysis to its first and second principal odor component (POC). All healthy subjects could clearly be distinguished from patients with renal failure using quadratic discriminant analysis, whereas a correct classification of 95.2% (98.4% using 1st-3rd POC) of patients between end stage renal failure and chronic renal failure was found. This methodology of analyzing human body odor may also provide new approaches for investigating symptoms of renal failure and for diagnosing other diseases of internal or cutaneous origin.

Biomarkers↗
PubMed1999

Balance disturbances in individuals with vibroacoustic disease.

INTRODUCTION: In previous studies, patients with vibroacoustic disease (VAD) presented hyperintense foci in T2 of the cerebral white matter, brainstem and basal nuclei. The most probable etiology is ischemia. One of the most frequent complaints of these patients is balance disturbances which, in two cases, has threatened the patients' ability to maintain their jobs. The purpose of this study was to compare two methods, one neurophysiological (auditory evoked potentials - AEP) and the other structural imaging (brain MRI), in order to determine to what extent the changes detected with these methods may be related to each other in this pathology. METHODS: Twenty individuals occupationally exposed to large pressure amplitude (> or = 90 dB SPL) and low frequency (< or = 500 Hz) noise, received neurological and otorhinolaryngological examinations. All of them had previously received audiograms, tympanograms and electronystagmograms. All 20 patients also received brain MRI and AEP studies. RESULTS: The individuals with vertigo and changes of the AEP present the greater number of changes in the brain MRI. CONCLUSION: This could be an indication that in many VAD cases vertigo may have a central origin.

Adult↗
PubMed2002

The effects of thyroxine on metabolism and water balance in a desert-dwelling rodent, Merriam's kangaroo rat (Dipodomys merriami).

Desert-dwelling mammals such as Merriam's kangaroo rat (Dipodomys merriani) need to conserve both energy and water to survive desert conditions characterized by aridity and low productivity. The thyroid hormone thyroxine increases both basal metabolic rate and urinary water loss in mammals. Increases in basal metabolism and urinary water loss are likely to be detrimental to D. merriami, therefore the regulation of this hormone may be important. To examine the effects of thyroxine in this species, we implanted adult kangaroo rats with pellets designed to release specific doses of thyroxine at a constant rate for 90 days or a placebo pellet. We measured plasma thyroxine concentration, basal metabolic rate, food consumption, urine concentration and water loss in all implanted animals. Thyroxine implants significantly increased both plasma thyroxine and basal metabolic rate in a relatively dose-dependent manner. In response to thyroxine. kangaroo rats increased food consumption only slightly, but this small increase was sufficient to compensate for their elevated metabolic rates. Neither urine concentration nor water loss varied among treatment groups. Thyroxine increased energy expenditure but not water loss in this species.

Animals↗
PubMedDate not supplied

Parenteral arginine infusion in humans: nutrient substrate or pharmacologic agent?

When given as a dietary supplement, arginine enhances lymphocyte mitogenesis and improves nitrogen balance. The purpose of this study was to evaluate arginine's ability to mediate these same effects when given as the sole nitrogen source with minimum additional calories. Thirty patients were randomized to receive 20 g/day arginine hydrochloride or a mixed amino acid solution (Travasol) by intravenous infusion for 7 days after abdominal operations. Mean patient age, body weight, gender ratios, and preoperative degree of weight loss were similar between groups. Mean plasma arginine and ornithine levels rose to 228 +/- 50 mumol/L and 191 +/- 76 mumol/L in the arginine group during infusion. Mean nitrogen balance was -8.8 g/day and -9.2 g/day in the arginine and Travasol groups, respectively. Mean lymphocyte stimulation indices to concanavalin A and phytohemagglutinin fell on postoperative day 1 in both groups. No significant differences in patterns of lymphocyte mitogenesis changes were noted between groups. The mean total number of circulating T cells increased in the arginine group at postoperative day 7. Thus, parenteral arginine infusion in postoperative patients provided comparable nitrogen balance to a balanced amino acid solution but did not increase peripheral blood lymphocyte mitogenesis. When arginine is given parenterally as the sole nitrogen source with minimal additional calories to postoperative patients, no enhancement of mitogen-stimulated lymphocyte proliferation could be demonstrated.

Aged↗
PubMed1996

Mobility and balance in the elderly: a guide to bedside assessment.

Elderly patients often have impaired balance and loss of mobility. Regular assessment of mobility status is essential to ensure that appropriate support is provided and to monitor recovery. Functions that should be assessed include mobility in bed, ability to rise to a sitting position, ability to transfer from bed to chair and in and out of a bathtub, balance, ambulation, and gait. Evaluation can be performed quickly at the patient's bedside. For some patients, stretching and strengthening exercises may help restore function.

Aged↗
PubMed2005

Development of postural control in healthy children: a functional approach.

From a set of experimental studies showing how intersegmental coordination develops during childhood in various posturokinetic tasks, we have established a repertoire of equilibrium strategies in the course of ontogenesis. The experimental data demonstrate that the first reference frame used for the organization of balance control during locomotion is the pelvis, especially in young children. Head stabilization during posturokinetic activities, particularly locomotion, constitutes a complex motor skill requiring a long time to develop during childhood. When studying the emergence of postural strategies, it is essential to distinguish between results that can be explained by biomechanical reasons strictly and those reflecting the maturation of the central nervous system (CNS). To address this problem, we have studied our young subjects in situations requiring various types of adaptation. The studies dealing with adaptation of postural strategies aimed at testing short and long-term adaptation capacity of the CNS during imposed transient external biomechanical constraints in healthy children, and during chronic internal constraints in children with skeletal pathologies. In addition to maintenance of balance, another function of posture is to ensure the orientation of a body segment. It appears that the control of orientation and the control of balance both require the trunk as an initial reference frame involving a development from egocentric to exocentric postural control. It is concluded that the first step for children consists in building a repertoire of postural strategies, and the second step consists in learning to select the most appropriate postural strategy, depending on the ability to anticipate the consequence of the movement in order to maintain balance control and the efficiency of the task.

Adaptation, Physiological↗
PubMed2001

Tipping the balance between replicative and simple transposition.

The bacterial insertion sequence IS903 has the unusual ability to transpose both replicatively and non-replicatively. The majority of products are simple insertions, while co-integrates, the product of replicative transposition, occur at a low frequency (<0.1% of simple insertions). In order to define the critical steps that determine the outcome of IS903 transposition, we have isolated mutants that specifically increase the rate of replicative transposition. Here we show that the nucleotide immediately flanking the transposon influences both overall transposition frequency and co-integrate formation. In particular, when the 3'-flanking nucleotide is A, co-integrates are increased 500-fold compared with a 3' C. In addition, we have isolated five transposase mutants that increase replicative transposition. These residues are close to the catalytic residues and are thus likely to be part of the active site. These are the first transposase mutations described that affect the product of transposition. Our results are consistent with the hypothesis that a delay in cleavage of the 5'-flanking DNA will increase the effective half-life of the 3'-nicked transposon intermediate and consequently enhance co-integrate formation.

Amino Acid Sequence↗
PubMed2001

Sodium and chloride regulation in freshwater and osmoconforming larvae of Culex mosquitoes.

In this study, we examined aspects of Na(+) and Cl(-) regulation in mosquito larvae of the genus Culex, a group that includes species that tolerate high salinity as well as other forms that are restricted to fresh water. When the euryhaline osmoconformer C. tarsalis was acutely transferred from 30 % to 50 % sea water, the patterns of hemolymph Na(+) and Cl(-) regulation were similar. The underlying regulatory mechanisms for these two ions have very different characteristics. In C. tarsalis, Na(+) efflux was significantly elevated compared with the rates measured in the freshwater-restricted C. quinquefasciatus, while Cl(-) influx was relatively lower. The modulation of Na(+) efflux and Cl(-) influx allowed C. tarsalis to avoid a potential salt load and ionic disturbance in the hemolymph during an acute increase ( )in salinity. The observed adjustment of NaCl regulation departs from that determined for other euryhaline organisms and is integral to the osmoconforming response. At the other extreme of the salinity spectrum, we observed that C. tarsalis faces difficulties in ion regulation in habitats with low NaCl levels because of its inability to reduce ion efflux and adjust ion absorption rates to maintain hemolymph ion balance. In contrast, C. quinquefasciatus exhibited a reduced ion efflux and the ability to upregulate Na(+) uptake, traits necessary to extend its lower salinity limit.

Animals↗
PubMed1993

[Investigation of activity of daily living performance in patients with Duchenne muscular dystrophy].

The purpose of this study was to reach a better understanding the deficits of activity of daily living (ADL) skills in patients with Duchenne muscular dystrophy (DMD), and their influencing factors. Our samples consisted of 35 male DMD patients, aged 3-24 years. The Barthel index was used to assess daily living abilities. Besides ten different motor abilities, muscle strengths of both upper and lower extremities and joint contractures were also included in each patient's evaluation. The results of degree of severity in ADL performance showed that 21.1% of patients were classified as totally dependent, 48.5% were severely dependent, 12.1% moderately dependent, 9.1% mildly dependent and 9.1% totally independent. Among the ADL skills, the bathing needed most assistance whereas feeding required the least. Two of the sixteen factors influencing ADL performance was calculated to be significant after stepwise multiple regression analysis. They were hip contracture and static sitting balance. In conclusion, we find that DMD patients are highly dependent in carrying out ADL tasks. Therefore, it is very important to avoid contracture, to increase static sitting balance and to use appropriate devices to improve their daily living abilities. Finally, the Barthel index proved acceptable in evaluating Taiwanese children over six years of age.

Activities of Daily Living↗
PubMed2006

Dual function of the long pentraxin PTX3 in resistance against pulmonary infection with Klebsiella pneumoniae in transgenic mice.

The long pentraxin PTX3 is expressed during acute inflammation and appears to control nitric oxide (NO) and tumor necrosis factor (TNF)-alpha production. In the present study, the physiological function of PTX3 was investigated in a model of pulmonary infection caused by the Gram-negative bacterium Klebsiella pneumoniae. Transgenic mice expressing multiple copies of PTX3 under the control of its own promoter were used to assess lethality rates, bacterial counts and inflammatory indices following pulmonary infection of mice. Expression of PTX3 is enhanced during pulmonary infection in wild-type mice. In transgenic mice given a high inoculum, overt PTX3 expression was associated with faster lethality. Faster lethality correlated with enhanced nitrate in plasma, an inability of neutrophils to migrate to lung tissue and greater dissemination of bacteria to blood at 20h after infection. In contrast, transgenic PTX3 expression conferred protection to mice given lower pulmonary inocula. In the latter experiments, there was enhanced TNF-alpha production, greater neutrophil influx and phagocytosis of bacteria by migrated neutrophils. By controlling the production of TNF-alpha and NO, and depending on the intensity of the inflammatory response induced by a given inoculum, the expression of PTX3 may favor or disfavor the influx of neutrophils and the ability of the murine host to deal with pulmonary infection with K. pneumoniae. These experiments highlight the delicate balance that exists among the various mediators that control the inflammatory response and suggest that PTX3 is an essential part of the ability of a host to deal with bacterial infection.

Animals↗
PubMed2001

Regulation of macronutrient balance in healthy young and older men.

OBJECTIVE: To determine the influence of age on the ability to adjust macronutrient oxidation to changes in diet composition. Our hypothesis was that the ability to adjust macronutrient oxidation to changes in diet composition would be impaired with age. DESIGN: Cross-sectional, randomized to three different isocaloric diets containing a constant percentage protein but varying in percentage fat and percentage carbohydrate: mixed diet (M; 15/30/55); high-fat diet (HF; 15/60/25), and high-carbohydrate (HC; 15/15/70). SUBJECTS: Six young (YM; age=25+/-1 y) and five middle-aged and older men (OM; age=63+/-3 y). MEASUREMENTS: Each subject underwent 24 h whole-room calorimetry on day 4 of each diet to determine 24 h macronutrient oxidation rates. Macronutrient balance was calculated from the individual macronutrient oxidation rates and the corresponding macronutrient intake. RESULTS: Body mass, percentage fat, and fat-free mass were similar in the two groups. Twenty-four-hour energy expenditure (EE) and energy balance did not differ across diets or between groups; 24 h EE was approximately 7% lower (NS) in the OM. Macronutrient oxidation rates were not significantly different in YM vs OM during M. Protein oxidation was similar across diets, but higher (P<0.05) in OM. Fat oxidation contributed 28.8+/-7.0% vs 37.8+/-4.7% to 24 h EE on M (NS) in the OM vs YM, respectively. This increased to 58.4+/-6.7 vs 51.9+/-5.3% of 24 h EE (NS) in the OM vs YM, respectively, during HF and decreased to 25.4+/-9.7 vs 20.2+/-14.3% (NS) during HC (diet effect, both P<0.05). Carbohydrate oxidation contributed 54.3+/-10.5% vs 56.6+/-2.4% of 24 h EE (NS) on M in the OM vs YM, respectively. This decreased to 19.5+/-10.6 vs 29.9+/-12.6% (NS) during HF and increased to 53.6+/-12.3 vs 64.7+/-14.3% (NS) in the OM vs YM, respectively during HC (diet effect, P<0.05). CONCLUSION: Taken together, these results suggest that the ability to adjust macronutrient oxidation to changes in diet composition is maintained in OM and, thus, is unlikely to contribute to the increased susceptibility to weight gain and obesity development that accompanies aging.

Adult↗
PubMed1988

Patterns of visual-spatial performance and 'spatial ability': dissociation of ethnic and sex differences.

Is there a common basis for the ethnic and sex differences that are characteristically obtained on psychometric tests of spatial ability? Three experiments approached this question by observing subject differences in the recognition and reconstruction of visual-spatial displays. The pattern of performance on these experimental tasks was compared with that on a traditional spatial ability test. In the first experiment, two samples of 40 students, balanced for sex, from Zimbabwe and Scotland respectively, attempted a forced-choice recognition task for meaningful scenes. Both ethnic groups and both sexes showed equivalent performance. The same subjects then undertook a task involving the reproduction of an arrangement of blocks into two-dimensional plan and elevation views. On this task, involving spatial reorientation, the Zimbabweans made over three times as many errors as the Scots. In a third experiment the requirement for spatial reorientation was added to the original recognition task and this was performed by a further 40 subjects. A significant difference between ethnic groups now emerged and this effect covaried with spatial ability. Again, however, no sex difference was observed. The overall pattern of results points to spatial reorientation as a major factor in the cross-ethnic differences. The absence of a sex difference on the experimental tasks contrasts with its appearance in both samples on the spatial ability test and represents a puzzling obstacle to our current understanding. This dissociation of sex and ethnic differences provides evidence against the hypothesis that they stem from the same source.

Adult↗
PubMed1997

The consequences of a mild respiratory chain deficiency on substrate competitive oxidation in human mitochondria.

The competition between the respiratory substrates to gain access simultaneously to the respiratory chain depends on the dehydrogenase activity, the mitochondrial ubiquinone pool, and the oxidizing activity of the cytochrome segment. By studying the co-oxidation of NADH and succinate by control human liver homogenates, we found that a change in the balance between respiratory chain complex activities may affect significantly the ability of the mitochondria to oxidize one or the other substrate. Accordingly, in the particular case of a patient presenting with a partial complex I and IV deficiency, we observed a strongly reduced ability to oxidize NADH in the presence of succinate. It therefore appeared that even a slight imbalance between respiratory chain enzyme activities may result in a full blockade of a given substrate oxidation.

Cytochrome-c Oxidase Deficiency↗
PubMed1995

The dynamics of mitochondrial plasmids in a Hawaiian population of Neurospora intermedia.

We analysed the distribution of mitochondrial plasmids among 82 Neurospora intermedia isolates from Hawaii; 74% of the isolates carried the neutral circular plasmid Han-2, whereas 38% contained the linear senescence-causing plasmid kalDNA. The distributions of the two plasmids are independent. There is no significant difference between the Kauaian population of 1972 and that of 1976. To further examine the reasons for this frequency distribution we studied the transmission of both Hawaiian plasmids through the maternal parent in a large series of crosses using non-Kalilo isolates as conidial parents. Plasmids can be lost during the sexual cycle. The Han-2 plasmid is transmitted more efficiently than kalDNA. No clear cases of autonomous or non-autonomous plasmid suppression were observed, so loss can be considered accidental. One Kalilo strain proved to be ineffectual as a maternal parent, and this reduced its ability to transmit kalDNA to the next generation. The dynamic balance of plasmids in natural populations over time is probably a result of the interplay of many forces, including those described in this work and those from several other studies on Neurospora plasmids.

Crosses, Genetic↗
PubMed2004

Dementia in Parkinson's Disease.

One of the more recently recognized problems in treatment of patients with Parkinson's disease (PD) is development of cognitive dysfunction and, in many cases, frank dementia. As patients with PD live longer, because of improved care and treatment of motor symptoms, dementia in PD is becoming a major contributor to morbidity in the illness. Prevalence studies suggest that up to 30% of patients with PD develop dementia. Dementia in PD patients is often a multifactorial condition. Neuropathologic changes caused by PD itself may cause memory loss. However, some patients with PD and memory decline also have pathologic changes that are more consistent with Alzheimer's disease. Many PD patients have a mix of the two types of pathology. Other factors, such as underlying illnesses, medication side effects, and interaction of therapeutic agents, may contribute to cognitive changes in PD patients. Predictors of development of dementia in PD include advancing age and severity of neurologic symptoms, which may interact with one another to produce this effect. Recent work suggests that tobacco use also may increase risk of PD dementia, despite its possible protective effect against development of PD itself. Presence of psychiatric illness, especially depression, may interfere with cognition and exacerbate memory loss. Reduction in the dose of dopaminergic agents and of other medications may be helpful in partially improving cognitive function in some cases. The balance between improvement of motor function and preservation of cognitive abilities must be weighed, and it is important for clinicians to discuss this trade-off with patients and their families. At this time, there is no US Food and Drug Administration-approved pharmacologic treatment for dementia in PD. However, medication used to treat Alzheimer's disease, such as acetylcholinesterase inhibitors, may slow progression of memory loss in some PD patients. Based on work from small double-blind studies, open-label trials, and case reports, cholinesterase inhibitors may be tried for treatment of dementia in PD, as long as the patient and caregivers understand that these agents are being used on an off-label basis. Surgical intervention, such as deep brain stimulation of the subthalamic nucleus or globus pallidus internus, although useful for treatment of motor symptoms in some PD patients, does not improve cognitive function in most cases and may actually worsen cognition in patients with pre-existing dementia. There is no specific exercise regimen or dietary guidelines for patients with PD who develop dementia. However, patients should be encouraged to lead a healthy lifestyle; this may improve overall well-being, which could impact positively on cognition function. Similarly, although assistive devices have not been developed for people with PD who have memory loss, any aid that increases mobility will probably improve mental and physical function. Clinicians should be mindful of the increased caregiver burden posed by PD patients who also have dementia. They should intervene appropriately to prevent caregiver distress and "burn out." Herbal and nutritional supplements have not been shown in clinical trials to be beneficial for treatment of any type of dementia, and thus are not recommended for PD patients with cognitive decline.

Journal Article↗
PubMed1994

Tick-induced modulation of the host immune response.

The tick-host-pathogen interface is characterised by complex immunological interactions. Host immune responses to tick infestation and infection with tick-borne pathogens involve cytokines, antibodies, complement and T lymphocyte regulatory and effector pathways. A successful host-parasite relationship is a balance between limiting the parasite by host defenses and the ability of the parasite to modulate, evade or restrict the host response. Hosts acquire immunological based resistance to tick infestation, which reduces engorgement, production of ova and viability. Salivary glands of ixodid ticks produce a complex array of immunogens and pharmacologically active molecules. Tick salivary gland derived material can modulate host cytokine, antibody and cell mediated immune responses. Both immunoregulatory and immune effector pathways of the host are suppressed. Tick feeding impairs the ability to develop a primary immune response to a thymic dependent immunogen. Lymphocytes obtained from tick infested hosts are reduced in their ability to proliferate in vitro to T lymphocyte mitogens, while responses to B lymphocyte polyclonal activators are unaltered. Normal macrophages and lymphocytes were exposed to female tick salivary gland extracts prepared daily during the course of engorgement. All extracts reduced lymphocyte responses to T cell mitogens and enhanced in vitro proliferation in the presence of a B lymphocyte mitogen. Macrophage elaboration of tumour necrosis factor alpha and interleukin-1 are significantly reduced in a differential manner. Production of interleukin-2 and interferon-gamma by T lymphocytes is reduced. Tick modulation of the host immune response could enhance the ability of the arthropod to obtain a blood meal and facilitate pathogen transmission to an immunocompetent host.

Animals↗
PubMed2006

Surviving cell death through epidermal growth factor (EGF) signal transduction pathways: implications for cancer therapy.

There is a balance between cell death and survival in living organisms. The ability of cells to sense their environment and decide to survive or die is dependent largely upon growth factors. Epidermal growth factor (EGF) is a key growth factor regulating cell survival. Through its binding to cell surface receptors, EGF activates an extensive network of signal transduction pathways that include activation of the PI3K/AKT, RAS/ERK and JAK/STAT pathways. These pathways predominantly lead to activation or inhibition of transcription factors that regulate expression of both pro- and anti-apoptotic proteins effectively blocking the apoptotic pathway. In cancer, EGF signaling pathways are often dysfunctional and targeted therapies that block EGF signaling have been successful in treating cancers. In this review, we will discuss the EGF survival signaling network, how it cross-talks with the apoptotic signaling pathways and the therapeutic drugs targeting the EGF survival pathway used to treat cancers.

Animals↗