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Results for “Balance ability”

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At least 361 records · Page 20Linked to original sources

PubMed1995

Effect of early lead exposure on children's postural balance.

This study investigated the effect of chronic exposure to lead on children's ability to maintain upright postural balance as a biological marker of lead-induced modifications of the neuromotor system. For this study, 162 six-year-old children, with a five-year geometric mean lead concentration in blood of 11.9 micrograms/dL (range 4.0-28.0 micrograms/dL), were tested for postural balance with a microprocessor-based force platform system. An increase in blood lead was significantly associated with an increase in the variable postural sway--implying poorer postural balance. This association was not influenced by socio-economic, racial or environmental factors. This simple, objective and quick technique may be useful for assessing gross motor functions in children who are at or below the United States Centers for Disease Control's class III category and/or for monitoring the effectiveness of medical interventions aimed at reversing lead-associated impairment of upright postural balance.

Child↗

PubMed2002

Effect of arterial baroreceptor denervation on sodium balance.

During chronic increased dietary sodium intake, arterial baroreceptors buffer against sustained increases in arterial pressure, and renal sympathoinhibition contributes importantly to the maintenance of sodium balance by decreasing renal tubular sodium reabsorption and increasing urinary sodium excretion. The present study examined the effect of arterial baroreceptor denervation on sodium balance in conscious rats during low, normal, and high dietary sodium intake. Compared with measurements made before arterial baroreceptor denervation, arterial baroreceptor-denervated rats had similar sodium balance during normal dietary sodium intake but significantly more negative sodium balance during low dietary sodium intake and significantly more positive sodium balance during high dietary sodium intake. At the end of the high dietary sodium intake period, arterial pressure (under anesthesia) was 159+/-5 mm Hg after arterial baroreceptor denervation and 115+/-1 mm Hg before arterial baroreceptor denervation. Sham arterial baroreceptor denervation in time control rats had no effect on sodium balance or arterial pressure during the different dietary sodium intakes. These studies indicate that (1) arterial baroreceptor denervation impairs the ability to establish sodium balance during both low and high dietary sodium intake, and (2) arterial baroreceptor denervation leads to the development of increased arterial pressure during high dietary sodium intake in association with increased renal sodium retention.

Animals↗

PubMed2003

Antitumor activity of wheats with high orthophenolic content.

The purpose of the present study is to develop in vitro assays for rapid screening of a large number of food samples that contain components that prevent tumor formation in vivo and to identify the components that contribute to this antitumor effect. Wheat samples representing numerous strains and cultivars were screened for their in vitro ability to kill a human colon cancer cell, CaCo2, in culture by trypan blue dye exclusion assay. Wheat samples were assayed for orthophenolic acid content by use of a colorimetric assay using a bathochromatic shift at 350 nm. Blood levels of specific orthophenols were determined by high-performance liquid chromatography/mass spectrometry. Wheat samples, which contained low, mid-, and high in vitro protective ability, were used to formulate balanced diets fed to Min mice. Wheat samples with high ability to kill CaCo2 cells in culture had high levels of orthophenolic acids and produced elevated blood caffeic acid levels when used in diets. These factors correlated positively with their ability to prevent tumor formation in Min mice. When fiber content was equal in diets the content of orthophenolic acids in wheats predicted the antitumor activity in vivo.

Animals↗

PubMed2000

A prospective study of laboratory and clinical measures of postural stability to predict community-dwelling fallers.

BACKGROUND: The identification of specific risk factors for falls in community-dwelling elderly persons is required to detect early changes and permit a preventative approach to management. This study determines the ability of various laboratory measures and clinical tests of postural stability to prospectively predict fallers in community-dwelling elderly women. METHODS: One hundred elderly women (65-86 years, mean age 73 +/- 5 years) performed a reaction-time step task, a limits of stability, and a quiet stance balance task. Postural muscle timing and movement speed were recorded during the step task. Center of pressure (COP) motion was recorded in quiet stance and at the limits of stability. Four common clinical balance tests were performed, and balance confidence, medical and activity history questionnaires were completed. Subjects were followed up regularly for a 6-month period following testing to determine the frequency and characteristics of any falls that occurred. Predictive capabilities of the balance measures to determine fallers were determined through logistic regression models. RESULTS: The clinical balance tests investigated were not able to predict fallers in this community-dwelling elderly population. A combination of variables from the laboratory tasks provided the best overall prediction rate (77%) of fallers (sensitivity 51%) and nonfallers (specificity 91%) from laboratory measures. Of these, step movement time and gluteus medius onset times were the factors best able to predict fallers. Alone, measures of COP motion in quiet stance and at the limits of stability had a poor ability to predict fallers, although they could correctly identify most nonfallers. Prediction was not significantly improved when clinical balance test results were added to the most predictive laboratory measures. CONCLUSIONS: Not all older adults with a reduction in balance ability reported a fall over a 6-month period. Of those who did, a combination of measures reflective of different aspects of mediolateral postural stability during a rapid step task, quiet stance, and movement to the limits of stability were best able to predict faller status, with nonfallers better predicted than fallers. These results emphasize the importance of the multifactorial nature of falls in the community-dwelling elderly population in that the clinical and laboratory measures did not predict a high proportion of fallers.

Accidental Falls↗

PubMed1997

The outcome of scoliosis surgery in the severely physically handicapped child. An objective and subjective assessment.

STUDY DESIGN: A prospective, functional assessment based on physical ability and independence in daily activities was performed of patients who had severe physical handicaps and spinal deformities and were undergoing scoliosis surgery. OBJECTIVES: To determine whether improving spinal alignment and truncal balance improved the functional abilities of handicapped patients. SUMMARY OF BACKGROUND DATA: Loss of truncal stability compromises the physical independence of children who are severely handicapped. Physiologic function also may be compromised. It is not clear whether improving truncal balance actually improves their level of independence or merely halts further deterioration. METHODS: Twenty patients with significant physical handicaps resulting from neuromuscular disorders or multiple congenital anomalies and significant spinal deformity and truncal imbalance were treated surgically to realign and stabilize their spines. Their level of physical independence was evaluated before surgery, including their ability to sit, ambulate, and complete activities of daily living. Evaluation was done before surgery, 6 months after surgery, and 12 months after surgery. A subjective assessment of cosmesis also was made. RESULTS: Corrective spinal surgery resulted in a deterioration of physical ability for the first 6 months. Most patients subsequently returned to their preoperative level of function. An improvement of function exceeding their preoperative level was not seen after 12 months. The cosmetic results of surgery were excellent. CONCLUSIONS: Corrective spinal surgery in patients with severe physical handicap should be performed early to preserve function and should not be dictated solely by the severity of the curvature. Improvement in the patient's level of independence may not necessarily occur after truncal stabilization. Cosmetic results in these patients with severe disabilities were extremely gratifying to the patients and their caregivers.

Activities of Daily Living↗

PubMed2000

A model of the endogenous glucose balance incorporating the characteristics of glucose transporters.

This paper describes the development and preliminary test of a model of the endogenous glucose balance that incorporates the characteristics of the glucose transporters GLUT1, GLUT3 and GLUT4. In the modeling process the model is parameterized with nine parameters that are subsequently estimated from data in the literature on the hepatic- and endogenous- balances at various combinations of blood glucose and insulin levels. The ability of the resulting endogenous balance to fit blood glucose measured from patients was tested on 20 patients. The fit obtained with this model compared favorably with the fit obtained with the endogenous balance currently incorporated in the DIAS system.

Biological Transport, Active↗

PubMed1999

Effect of an orally active Th1/Th2 balance modulator, M50367, on IgE production, eosinophilia, and airway hyperresponsiveness in mice.

We have found a novel anti-allergic agent, M50367, which suppresses IgE biosynthesis and eosinophil accumulation in vivo. In this study, we evaluated the ability of M50367 to modulate Th1/Th2 balance in Th2-background BALB/c mice and to inhibit airway hyperresponsiveness in a murine model of atopic asthma. Oral M50367 at 3-30 mg/kg/day exhibited 51 to 73% reduction of IL-4/IL-5 production and 2- to 5-fold augmentation of IFN-gamma production by Ag-stimulated cultured splenocytes of the mice sensitized with DNP-Ascaris. These alterations in Th1/Th2 cytokine production were accompanied by 55-85% suppression of plasma IgE level. Oral M50367 at a dose of 10 mg/kg/day significantly inhibited Ig-independent peritoneal eosinophilia by 54%, which was induced by repeated i.p. injections of Ascaris suum extract. To develop airway hyperresponsiveness caused by allergic airway inflammation, BALB/c mice were sensitized with i.p. OVA injections, followed three times by OVA inhalation. Oral M50367 significantly inhibited the increase in airway reactivity to acetylcholine, together with the elevation of plasma IgE level and pulmonary eosinophilia, which were observed in vehicle-treated mice 1 day after the last inhalation. Moreover, M50367 treatment reduced IL-4 and IL-5 production and tended to enhance IFN-gamma production, not only by cultured splenocytes, but also in bronchoalveolar lavage fluid. These results suggest that M50367 has a modulating ability of Th1/Th2 balance to down-regulate Th2 response in the circulating system as well as at the sites of inflammation, and may be beneficial for the treatment of allergic disorders such as atopic asthma.

Adjuvants, Immunologic↗

PubMedDate not supplied

Magnetically coupled balance platform.

The purpose of this study was to develop a new device to assess balance in two planes and then to provide training paradigms for balance abnormalities. Based on the principal of a Biomechanical Ankle Platform System (BAPS) board, the device is different than other devices that are on the market today in that this device allows assessment of balance during body sway movement in the forward\back and side-to-side directions. Like the BAPS board, individuals balance themselves on the board with a pivot in the centre. However, unlike the BAPS board, a variable viscosity magnetic fluid is used to vary the dampening on the board such that the board can be fixed in the forward\back or side-to-side plane. It can also be allowed to move either freely in both planes or with some dampening in any direction. This device offers a major improvement over other balance measuring devices in that it allows movement in multiple planes. It also allows for rapid alterations of movement in any plane to test an individual's ability to maintain their balance against a challenge.

Diagnosis, Computer-Assisted↗

PubMed1999

A synergistic effect of extracellular hypocalcemic condition for hyperoxic reoxygenation injury in rat hepatocytes.

BACKGROUND: Calcium accumulation of cells and mitochondria during reperfusion or reoxygenation has been implicated as a potential factor in cell injury as the result of mitochondrial damage. The objective of this study was to disclose whether or not low extracellular calcium ion concentration ([Ca2+]ex) in the medium at the time of reoxygenation might prevent calcium accumulation and attenuate hepatocytes injury after severe hypoxia. METHODS: Isolated rat hepatocytes were incubated under a hyperoxic or hypoxic atmosphere for 60 min. During the ensuing 60-min hyperoxic reoxygenation, medium [Ca2+]ex was varied from 0.6 microM to 2.0 mM by altering total calcium and addition of chelators. RESULTS: Incubation in low [Ca2+]ex reduced total cellular calcium and mitochondrial calcium in both the hyperoxic and hypoxic group. Under hyperoxic/hyperoxic incubation (control), hepatocytes were able to maintain potassium balance when [Ca2+]ex was >3.0 microM (pCa=5.5) and cellular viability (% lactate dehydrogenase release) at all levels of extracellular calcium. Under hypoxic/hyperoxic incubation (reoxygenation), however, loss of the ability to restore potassium balance as well as apparent increase in lactate dehydrogenase release were observed at severely low [Ca2+]ex (<30 microM; pCa=4.5). This low [Ca2+]ex-induced exacerbation of hepatocytes viability could not be generated under mild reoxygenation such as normoxia. CONCLUSIONS: In normal isolated hepatocytes, very low [Ca2+]ex levels produce only very subtle changes in membrane permeability of isolated hepatocytes. After hypoxia, however, hypocalcemia acts synergistically with hyperoxic reoxygenation to produce more severe damage. These results suggested that [Ca2+]ex should be maintained on the physiological level to attenuate hepatocytes injury after severe hypoxia.

Animals↗

PubMed1994

Nonlinear approaches for separation of slow and fast phase nystagmus signals.

Central nervous system (CNS) disorders and vestibulo-ocular reflex (VOR) degradation contribute to the loss of orientation and balance, typically causing the illusion of motion. VOR degradation may be caused by illnesses or common prescription medications, and this degradation may have serious repercussions in affecting one's ability to walk, maintain balance, or track moving objects. The two current VOR analysis techniques are applied to nystagmus signals (recordings of eye position during standardized tests) to isolate the two neuronal pathways used. These techniques are only partially successful because the VOR signal is passed through several filtering layers, to isolate the nystagmus signal, leaving it severely altered. In this paper, several alternate approaches are introduced: nonlinear robust ordering procedures, mathematical morphology, and wavelet filtering techniques are demonstrated. All approaches were as successful as the current techniques in isolating data from one neuronal pathway. Techniques for each of the three were also developed which would identify data from the second neuronal pathway as well. The nonlinear approach, which works using raw position data, bypasses layers of filtering. A robust technique is used to identify the points at which the data changes from that due to one neuronal pathway to the other, and the end result is obtained by concatenating the respective segments. The other two approaches work with velocity data obtained by differentiation, and because they are applied to non-original data, their results may be open to the possibility of error. Additionally, the two most recent approaches in the literature (using order statistic filters and fuzzy logic) have been implemented for a comparison of results.

Humans↗

PubMed1982

Physiologic and psychosocial assessment in labor.

The details of physiological and psychosocial assessment are available in many texts, and the techniques are relatively simple. Several assumptions underlie an excellent labor assessment: 1. that the nurse has a thorough knowledge of the physiological processes of pregnancy and labor; 2. that the nurse has a thorough knowledge of the psychosocial implications of pregnancy and labor; 3. that the nurse has the ability to set priorities and balance the focus of her assessment; 4. that the nurse has the ability to refrain from stereotyping the woman in labor; 5. that the nurse does not let her own expectations of feelings and behavior in labor mask what the patient is really experiencing; and 6. that the nurse is willing to follow up, evaluate, and reassess in order to verify her assessments and improve her assessment skills.

Adolescent↗

PubMed2004

Randomized clinical trial into the impact of rigid foot orthoses on balance parameters in excessively pronated feet.

OBJECTIVE: To evaluate the effect of rigid foot orthoses on balance parameters in participants with clinically diagnosed excessively pronated feet. DESIGN: Randomized clinical trial. SETTING: University biomechanics laboratory. PARTICIPANTS: Thirty female and 20 male healthy participants (mean 23.8+/-2.2 years old) with excessively pronated feet, according to a validated foot classification system were randomly assigned to either a control or intervention group. INTERVENTIONS: Balance testing was performed using the Balance Performance Monitor with an over-the-counter rigid foot orthoses. MAIN OUTCOME MEASURES: Standing balance in the form of mean balance (measures the participants ability to stand with an even load), medial-lateral sway and anterior-posterior sway. All participants were measured while standing bipedally. RESULTS: There was no significant mean difference in balance scores between the control and intervention group at baseline. After four weeks the results demonstrated no significant differences between mean% balance (p >0.05) and anterior-posterior sway (p >0.05). However, there was a reduction with the intervention group in medial-lateral sway (p=0.02). CONCLUSION: The use of foot orthoses in the current study may have improved postural control by stabilizing the rear foot and thus maintaining balance. By the same argument, the benefits of limiting excessive foot pronation may contribute to effective control of internal rotation of the tibia and thereby reduce counter-rotatory motion at the knee and lower leg and maintain balance.

Adult↗

PubMed1998

The balance of pro- and anti-inflammatory cytokines in cardiac surgery.

Homeostatic control of the balance of pro- and anti-inflammatory cytokines is important for the maintenance of health. Cardiac surgery, with its intense pro-inflammatory stimulus, constitutes a major challenge to the patient's ability to maintain this balance. Pre- and intraoperative factors influencing the maintenance of cytokine balance are discussed.

Journal Article↗

PubMed1999

Role of the splanchnic circulation in acid-base balance during cardiopulmonary bypass.

OBJECTIVE: The role of the splanchnic circulation in the development of the metabolic acidosis of cardiopulmonary bypass (CPB) is not fully understood. New quantitative methods of acid-base balance now offer the ability to define this phenomenon more accurately. Accordingly, we studied acid-base changes across the splanchnic circulation during CPB and defined and quantified the factors that contributed to acid-base balance. DESIGN: Prospective cohort study. SETTING: Tertiary institution. PATIENTS: Ten patients undergoing CPB for coronary artery bypass surgery. INTERVENTIONS: Sampling of arterial and hepatic venous blood at four time intervals: postinduction, on CPB during cooling and rewarming, and at skin closure. MEASUREMENTS: Measurement of serum Na+, K+, Mg++, Ca++, Cl-, HCO3-, and phosphate concentrations, arterial and hepatic venous blood gases and serum albumin, and lactate and pyruvate concentrations at each collection point. Analysis of findings according to quantitative physicochemical principles. MAIN RESULTS: All patients developed a mild metabolic acidosis with a decrease in median serum bicarbonate concentration from 24.97 mEq/L after induction to 22.29 mEq/L at cooling and 22.23 mEq/L at rewarming (p < .05). Before CPB, the pH decreased by 0.0275 (p < .05) across the splanchnic circulation, representing an increase of 2.26 nmol/L of hydrogen ions. Nevertheless, the splanchnic circulation induced a metabolic alkalosis, with a median transsplanchnic increase in the base excess of 1.50 mEq/L (p < .05). This change was largely due to a decrease in serum chloride and lactate concentration across the splanchnic circulation (p < .05). The acidifying effect of the splanchnic circulation was therefore the result of cell respiration with a median increase in carbon dioxide tension of 5.75 mm Hg (p < .05), causing the strong ion difference effective to increase by 1.94 mEq/L (p < .05). There were no other anions or acids added to the circulation by splanchnic organs (no change in strong ion gap). During and after CPB the splanchnic metabolic alkalinizing effect continued and the respiratory acidifying effect was reduced. This caused the splanchnic circulation to be pH neutral at these times. CONCLUSIONS: Using quantitative biophysical methods it can be demonstrated that the splanchnic circulation does not contribute to the metabolic acidosis of CPB, and that it continues to have a metabolic alkalinizing effect involving significant lactate extraction. However, its respiratory acidifying effect continues, although at a reduced rate.

Acid-Base Equilibrium↗

PubMed1994

Balance and stabilization capability of paraplegic wheelchair athletes.

The orientation of paraplegic athletes toward adapted sport activities required good knowledge of their functional characteristics. Wheelchair locomotion, especially for highly dynamic situations, poses the problem of trunk equilibrium management and head stabilization. The study aimed at designing a quantitative method to assess the ability of paraplegics to obtain trunk balance under dynamic stresses, and to analyze the various balance strategies, according to the spinal lesion level of the subjects. High (HPA) and low (LPA) paraplegic athletes were subjected to four series of antero-posterior stresses of increasing intensity, generated by an oscillating platform. By means of a computerized video-based movement analyzer, acceleration in the saggittal plane was measured at four different spinal level and, for each one, a damping factor was determined. This factor, computed at the head level, appeared to be representative of the subjects' ability to maintain balance. We attempted to differentiate balance strategies in the LPA and HPA groups through analysis of the relative contributions to damping of the thoracic and cervical spinal segments. The first results show an increasing tendency of neck reflex stiffening according to the neurological level.

Adolescent↗

PubMed2003

Phosphatases in concert with kinases set the gain for signal transduction through the T cell receptor.

The 'tunable activation thresholds' model for signal transduction through the T cell receptor (TCR)/CD3 signaling complex proposes that rapid cycles of phosphorylation and dephosphorylation are integral to regulating the frequency of protein-protein interaction, thus having considerable influence over the activation of downstream signaling pathways. Co-temporal activation of kinases and phosphatases could serve to modulate the ongoing signaling response, depending on the relative balance of their opposing enzymatic activities. Although recent reports have addressed the mechanisms by which specific kinase/phosphatase pairs contribute to the initiation and termination of signaling, we sought a more global understanding of the ability of the kinase/phosphatase balance to regulate, or "tune", the very proximal steps of TCR signaling in primary human T cells. Herein, we provide biochemical evidence that phosphotyrosine induction via the TCR is subject to fine-tuning based on the overall activity of kinases and phosphatases relative to one another, leading to cycles of phosphorylation and dephosphorylation, with implications for developing the next generation of immunotherapeutic agents.

Animals↗

PubMed1988

Relations of basic arithmetic and motor skills in deaf elementary school children.

3 segregated groups of Arab and Jewish deaf children of CA 10;9 (n = 28) were compared with a group of hearing Arab first graders (CA = 6;10, n = 32) on tests of basic arithmetic, static balance control, and the ability to suppress synkinetic finger movements. The hearing-impaired performed as well on arithmetic tasks and on the tests of synkinetic control as their normal peers who were four years younger, while on static balance they were even inferior to the latter. Significant correlations were found between the basic arithmetic and motor skills, within the hearing as well as within the hearing-impaired groups; these remained significant even within the small subgroups of the latter. As these results cannot be accounted for by low intelligence and neurological disturbances, or by direct or indirect effects of deficient language development, the assumption is supported that some type of neurological immaturity, unrelated to hearing loss, interferes with the acquisition of numerical skills in deaf children.

Achievement↗

PubMed2003

The comparative role of activator protein 1 and Smad factors in the regulation of Timp-1 and MMP-1 gene expression by transforming growth factor-beta 1.

The balance between matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), is pivotal in the remodeling of extracellular matrix. TGF-beta has profound effects on extracellular matrix homeostasis, in part via its ability to alter this balance at the level of gene expression. The intracellular signaling pathways by which TGF-beta mediates its actions include the Smad pathway, specific to the TGF-beta superfamily, but also, for example, mitogen-activated protein kinase pathways; furthermore, cross-talk between the Smads and other signaling pathways modifies the TGF-beta response. The reciprocal effect of TGF-beta on the expression of Timp-1 and MMP-1 supports its role in matrix anabolism, yet the mechanisms by which TGF-beta induces Timp-1 and represses induced MMP-1 have remained opaque. Here, we (i) investigate the mechanism(s) by which TGF-beta1 induces expression of the Timp-1 gene and (ii) compare this with TGF-beta1 repression of phorbol ester-induced MMP-1 expression. We report that the promoter-proximal activator protein 1 (AP1) site is essential for the response of both Timp-1 and MMP-1 to TGF-beta (induction and repression, respectively). c-Fos, JunD, and c-Jun are essential for the induction of Timp-1 gene expression by TGF-beta1, but these AP1 factors transactivate equally well from both Timp-1 and MMP-1 AP1 sites. Smad-containing complexes do not interact with the Timp-1 AP1 site, and overexpression of Smads does not substitute or potentiate the induction of the gene by TGF-beta1; furthermore, Timp-1 is still induced by TGF-beta1 in Smad knockout cell lines, although to varying extents. In contrast, Smads do interact with the MMP-1 AP1 site and mediate repression of induced MMP-1 gene expression by TGF-beta1.

Animals↗