Aerobic and resistance exercise training program intervention for enhancing gait function in elderly and chronically ill Taiwanese patients.

OBJECTIVES: This study aimed to develop an effective exercise training program for enhancing the postural stability and gait function of chronically ill patients to avoid falls. STUDY DESIGN: Pre training-post-training. Analyses were limited to those randomized to the exercise intervention. METHODS: The participants were chronically ill patients over 45 years old (47-89 years), of whom 25 completed the 12-week training regimen and assessment in the exercise group, whereas 29 completed the assessment in the control group, suffering from cardiovascular disease, diabetes mellitus, or osteoporosis. The average age of the participants was 67.56 ± 10.70 years in the intervention group. All patients in this study signed institutional review board (IRB) agreements before participating (IRB approval no: FEMH-IRB-101029-E, v. 02, date: 20120429). RESULTS: The results revealed the beneficial effects of regular aerobic and resistance training, which improved in elderly, chronically ill patients. According to our data, most of the gait function measurements exhibited significant differences between the exercise group and control group. The duration of the 'timed up-and-go' test decreased from 7.67 s to 6.76 s (P = 0.00013), and the 'the base of support area' increased from 392.0 cm(2) to 433.2 cm(2) (P = 0.0088). Women attained more significant differences than men in the exercise and control groups (P = 0.0008), and the participants aged 45-65 years had a more satisfactory outcome than those aged > 65 years (P = 0.0109). CONCLUSION: Regular exercise regimens, such as aerobic, resistance or combination exercise training, enhance the gait function and sense of postural stability in elderly, chronically ill patients. Younger patients attained more positive results than older patients, and women attained more positive results than men. Regular exercise is a means of preventing falls; thus, the government and hospitals should increase promotional measures in aging communities to encourage regular exercise among elderly, chronically ill outpatients.

Global comparison of gene expression between subcutaneous and intramuscular adipose tissue of mature Erhualian pig.

Adipose tissue plays an important role in energy metabolism and related diseases. The content of intramuscular fat significantly influences the pork quality. In this study, the whole gene expression of dorsal subcutaneous (s.c.) adipose tissue and intramuscular (i.m.) adipose tissue isolated from longissimus dorsi muscle tissue were compared using Affymetrix Gene-Chip microarray technology. The result revealed that 1228 genes were more highly expressed in s.c. adipose tissue, whereas 965 genes were higher expressed in i.m. adipose tissue. We found that the s.c. adipose tissue had a stronger capacity of lipid metabolism and fatty acid metabolism compared with i.m. adipose tissue, and angiopoietin-like-4, neuronatin, neuron-derived orphan receptor-1 alfa, and chloride intracellular channel 5 may play important roles in the regulation of fat deposition between i.m. and s.c. adipose tissues.

Inhibition of vascular endothelial growth factor A expression in mouse granulosa cells by lentivector-mediated RNAi.

Vascular endothelial growth factor (VEGF) has been found responsible for the induction of proliferation and differentiation in granulosa cells. We constructed four short hairpin RNA (shRNA) expression plasmids targeting the mouse VEGFA gene, and examined their effect on VEGF expression in mouse granulosa cells (MGC) in vitro. Four different shRNA oligonucleotides targeting the coding sequence of mouse VEGFA mRNA and one negative control (shNC) were designed and cloned into a pGPU6/GFP/Neo siRNA expression vector, and transiently transfected into MGC. At 48 h post-transfection, total RNA was extracted from the cells and subjected to qRT-PCR analysis. The most effective interference vector, shVEGF1487 was chosen for lentiviral construction. The recombinant plasmid was then transfected into 293FT cells via Lipofectamine(TM) 2000-mediated gene transfer, for the production of lentivirus, and then concentrated via ultracentrifugation. This lentiviral vector was then used for the transduction of MGC. VEGFA gene expression, apoptosis genes and VEGFA receptor genes were detected by qRT-PCR, the VEGFA protein level in culture media by ELISA assay and protein levels in MGC by Western blot analysis. The four VEGFA expression plasmids were successfully constructed and the most effective interference vector, shVEGF1487, was chosen for lentiviral production and MGC transduction. There was significant knockdown of the VEGFA gene, receptor genes and apoptosis genes for all the shVEGF constructs, compared with the shNC and Mock controls. The lentiviral vector also gave significant knockdown of the VEGFA gene. Protein levels were lower for most of the shVEGFs based on Western blot analysis with exception of VEGF1359; in this case, it was higher than shNC but lower than for the Mock group. Lentivector-transduced MGC also gave lower levels of protein. We conclude that shVEGF expression plasmids and lentivector carrying RNAi are promising tools for the inhibition of VEGF, the corresponding receptor genes, and apoptosis gene expression in MGC.

Doxycycline-regulated growth hormone gene expression system for swine.

Although growth hormone gene transgenic animals are much larger than normal animals, they manifest differences that have adverse effects on survival due to overexpression of growth hormone. We developed a stable pig embryonic fibroblast cell line expressing pig growth hormone (pGH) using the Tet-On system, with which we can conditionally manipulate expression of pGH in vivo. Inducible expression of pGH was achieved by combining reserve Tet-controlled transcriptional activator and tetracycline-responsive element in a single plasmid. The mRNA expression of pGH was significantly increased compared to the non-induced group by about 10-fold. The controlled secretion of pGH induced by doxycycline was further tested in stably transfected cells. We conclude that inducible GH expression can be achieved in pig embryonic fibroblasts.

Generation of induced pluripotent mouse stem cells in an indirect co-culture system.

Typically, production of induced pluripotent stem cells requires direct contact with feeder cells. However, once the stem cells have reached the appropriate maturation point, it is difficult to separate them from feeder cells, which must be irradiated with γ-rays or treated with the antibiotic mitomycin-C. We used a microporous poly-membrane-based indirect contact co-culture system with mouse embryonic fibroblasts to induce mouse pluripotent stem cells without radiation or antibiotics. We found that induced pluripotent stem cells induced by this co-culture method had a reprogramming efficiency and time similar to those induced using traditional methods. Furthermore, strongly expressed pluripotent markers showed a normal karyotype and formation and contained all three germ layers in a teratoma.

Testing the utility of mitochondrial cytochrome oxidase subunit 1 sequences for phylogenetic estimates of relationships between crane (Grus) species.

Morphology and biogeography are widely used in animal taxonomy. Recent study has suggested that a DNA-based identification system, using a 648-bp portion of the mitochondrial gene cytochrome oxidase subunit 1 (CO1), also known as the barcoding gene, can aid in the resolution of inferences concerning phylogenetic relationships and for identification of species. However, the effectiveness of DNA barcoding for identifying crane species is unknown. We amplified and sequenced 894-bp DNA fragments of CO1 from Grus japonensis (Japanese crane), G. grus (Eurasian crane), G. monacha (hooded crane), G. canadensis (sandhill crane), G. leucogeranus (Siberian crane), and Balearica pavonina (crowned crane), along with those of 15 species obtained from GenBank and DNA barcoding, to construct four algorithms using Tringa stagnatilis, Scolopax rusticola, and T. erythropus as outgroups. The four phylum profiles showed good resolution of the major taxonomic groups. We concluded that reconstruction of the molecular phylogenetic tree can be helpful for classification and that CO1 sequences are suitable for studying the molecular evolution of cranes. Although support for several deeper branches was limited, CO1 data gave remarkably good separations, especially considering that our analysis was based on just a fragment of the gene and that CO1 has generally been viewed as useful only for resolving shallow divergences.

Application of the Sleeping Beauty system in Saanen goat fibroblast cells for establishing persistent transgene expression.

The Sleeping Beauty (SB) transposon system is a promising new method for establishing persistent transgene expression in vivo. We applied the SB system for enhancing transgenesis in Saanen dairy goat fibroblast cells. We constructed a pKT2/CMV-EGFP-IRES-PURO vector and investigated the influence of transposon and transposase vector ratios on transfection efficiency in the Saanen goat fibroblast cells. To enhance the SB system performance, we developed a new transfection technique (double-transfection method) for the SB system. The cultured cells were transfected with transposase and transposon vectors successively, with a 42-h interval. Consequently, the transposase and DNA donor (transposon vector) can interact, both at the highest level. Compared with the traditional transfection method, this new double-transfection method approximately doubled integration efficiency.

Vergence dynamics predict fixation disparity.

The neural origin of the steady-state vergence eye movement error, called binocular fixation disparity, is not well understood. Further, there has been no study that quantitatively relates the dynamics of the vergence system to its steady-state behavior, a critical test for the understanding of any oculomotor system. We investigate whether fixation disparity can be related to the dynamics of opponent convergence and divergence neural pathways. Using binocular eye movement recordings, we first show that opponent vergence pathways exhibit asymmetric angle-dependent gains. We then present a neural model that combines physiological properties of disparity-tuned cells and vergence premotor cells with the asymmetric gain properties of the opponent pathways. Quantitative comparison of the model predictions with our experimental data suggests that fixation disparity can arise when asymmetric opponent vergence pathways are driven by a distributed disparity code.

Oculomotor function after virtual reality use differentiates symptomatic from asymptomatic individuals.

UNLABELLED: Some individuals who use virtual reality (VR) head-mounted displays (HMD) have adverse visual symptoms. PURPOSE: We measured oculomotor functions of symptomatic (n = 10) and asymptomatic (n = 10) individuals to determine if there were fundamental oculomotor performance differences. METHOD: Before and after 20 min of biocular VR-HMD use, we measured: phorias, fixation disparity, gradient accommodative convergence to accommodation ratio (AC/A), stereopsis, and nearpoint of convergence. RESULTS: We observed an exophoric shift in the nearpoint phoria of almost all subjects, whereas the farpoint phoria showed no trend. Interestingly, we observed that the phoric shift at far and near was highly correlated for the asymptomatic subjects but not for the symptomatic subjects. In addition, the (stimulus) AC/A ratio of symptomatic subjects was reduced after a period of VR-HMD use, whereas asymptomatic subjects' AC/A ratio was not reduced. CONCLUSION: The oculomotor changes among the symptomatic subjects (increased exophoria at near and reduced AC/A) appears consistent with a reduced accommodative response. In contrast, the asymptomatic subjects show changes (correlated change in phorias) which seem most consistent with adaptation in the tonic component of vergence and/or accommodation.

Nonlinear alteration of transient vergence dynamics after sustained convergence.

BACKGROUND: Adaptation models of the horizontal disparity vergence system assume a nonadaptable transient component. They also predict identical postadaptation dynamics during convergence and divergence movements. METHOD: To test the adaptation property of the transient component, a set of experiments were performed in which closed-loop vergence dynamics measured before and after sustained convergence were compared, primarily by comparing the peak vergence velocity, occurrence time of peak vergence velocity, and steady-state vergence posture. Vergence dynamics after durations of 30, 60, and 90 s of sustained convergence were compared with those after a control duration of 5 s. RESULTS: The peak divergence velocity was reduced by about 25% within 30 s of sustained vergence. However, the peak convergence velocity was unchanged for all the exposure durations. Additionally, for all durations, the peak divergence velocity was significantly higher than peak convergence velocity. In contrast to peak velocities, the occurrence time of peak convergence and divergence velocity did not differ significantly and remained unchanged for all durations. CONCLUSIONS: The transient component is adaptable. Furthermore, the adaptation is direction dependent and affects divergence and convergence dynamics differently, thereby suggesting involvement of separate pathways for convergence and divergence in the vergence sensorimotor control.

Effect of accommodative adaptation on static and dynamic accommodation in emmetropia and late-onset myopia.

PURPOSE: Prolonged near work is considered to be an environmental factor leading to the development of late-onset myopia. Accommodation may be the specific mechanism underlying the association between near work and late-onset myopia. To determine whether late-onset myopes have abnormal accommodation, we compared accommodative static responses and dynamic facilities before and after a near task in two groups of subjects, emmetropes and late-onset myopes. METHODS: In experiment 1, the accommodative stimulus/response function with monocular viewing and the dark focus (the accommodative response in the dark) were objectively measured with a Canon R-1 infrared optometer before (preadaptation) and after (postadaptation) a 20-min near task. In experiment 2, monocular accommodative facility (AF) and dark focus were measured before and after the near task. Facility was measured as the subjective time needed to clear an accommodative target (20/40 letters) at 40 cm through +/-2.00 D lenses. The time between when the subject flipped the lenses from viewing through the +2.00 D to the -2.00 D lenses was recorded by a computer. RESULTS: In both experiments, inward shifts of the dark focus were observed after the near task. In experiment 1, after the near task, static accommodative responses also showed a small but statistically significant inward shift. Neither postadaptation effect differed between refractive groups. The only difference between groups was that late-onset myopes had a lower slope of the accommodative stimulus/response function, both pre- and postadaptation. In experiment 2, both refractive groups showed the same results. After the near task, the duration for accommodation from near to far (relaxation) increased but the duration for accommodation from far to near (stimulation) did not change. CONCLUSIONS: Late-onset myopes have shallower accommodative stimulus/response functions. As suggested in a previous study, this may be due to their reduced sensitivity to defocus. In both emmetropes and late-onset myopes, the near task causes an increase in static accommodative responses. Although our results show it to be a small increase, it is consistent with predictions of Hung and Semmlow's model of accommodation. In both emmetropes and late-onset myopes, the near task also increases the duration for relaxing accommodation, but not for stimulating accommodation. This suggests there are two subsystems which may adapt to prolonged accommodation differently.

Oculomotor functions and late-onset myopia.

In order to elucidate the role of optical defocus in the development of late-onset myopia (LOM), we employed both theoretical and experimental approaches. In the theoretical study, which has been reported previously, we suggested a model in which an accommodative sensory operator was added to simulate the sensory part of the accommodation system. Results derived from the model showed that the sensory part might increase the system's threshold to the accommodative error (or defocus) signal. In this study, we measured the perceptual depth-of-focus and the system's threshold to the defocus signal for three refractive error groups: emmetropic (Emm), stable myopic (S.M.), and progressing myopic (P.M.). Results show that there are no significant differences in the perceptual depth-of-focus among the three groups. However, the defocus threshold values of the P.M. group are significantly higher than the values of the other two groups. This result in combination with our previous findings, leads us to suggest that individuals susceptible of developing myopia from sustained near-work have a specific oculomotor risk profile. Although we are still trying to determine the specific sequence of changes among dark-focus, AC/A ratio, the accommodative system's defocus threshold, and refractive error, we are convinced that the changes of oculomotor parameters underlie the type of myopia associated with near-work.

Integration of a sensory component into the accommodation model reveals differences between emmetropia and late-onset myopia.

PURPOSE: To evaluate the differences in accommodative function between subjects with emmetropia and those with late-onset myopia (LOM). METHODS: This study suggests a modified model of static accommodation, in which an accommodative sensory gain as a linear operator is added to simulate the sensory part of the system. Results derived from the model show that the sensory part not only affects the slope of the accommodative response function but also increases the system's effective threshold (ET) to the blur signal. This method expands the utility of using the control model to evaluate accommodation behavior. Thirteen emmetropic and 10 LOM subjects participated in this study. The subject's accommodative responses to one-, two-, three-, and four-diopter stimuli were measured by the Canon R-1 optometer, and the differences in dark focus, the slope of the accommodative response function, and the ET were compared between the emmetropic and the LOM subjects. RESULTS: The results show that although the dark-focus values and the slopes of the accommodative response function are not significantly different in emmetropia and LOM, the ETs are significantly different. CONCLUSIONS: The higher ET found among subjects with LOM suggests that either the blur (or the error) signal is degraded significantly in the sensory part of the system, the dead space as an internal threshold of the system is high, or both factors are important. On the basis of further analysis of the data, we speculate that the sensory system in LOM subjects was less sensitive to blur than that of the emmetropic subjects.

Neural network model of short-term horizontal disparity vergence dynamics.

We present a neural network model of short-term dynamics of the human horizontal vergence system (HVS) and compare its predictions qualitatively and quantitatively with a large variety of horizontal disparity vergence data. The model consists of seven functional stages, namely: (1) computation of instantaneous disparity; (2) generation of a disparity map; (3) conversion of the disparity into a velocity signal; (4) push-pull integration of velocity to generate a position signal; (5) conversion of the position signal to motoneuron/plant activity for each eye; (6) gating of velocity overdrive signal to motoneuron/plant system; and finally (7) discharge path for position cells. Closed-loop (normal binocular viewing) symmetric step and staircase disparity vergence data were collected from three subjects and model parameters were determined to quantitatively match each subject's data. The simulated closed-loop as well as open-loop (disparity clamped viewing) symmetric step, sinusoidal, pulse, staircase, square and ramp wave responses closely resemble experimental results either recorded in our laboratory or reported in the literature. Where possible, the firing pattern of the neurons in the model have been compared to actual cellular recordings reported in the literature. The model provides insights into neural correlates underlying the dynamics of vergence eye movements. It also makes novel predictions about the human vergence system.

Dark focus and dark vergence: an experimental verification of the configuration of the dual-interactive feedback model.

Based on the dual-interactive feedback model, dark focus and dark vergence designate a point on a line describing the response AC/A ratio. In order to verify the relationship between dark focus and dark vergence, we predicted the dark vergence from the measured dark focus when the measurements were based on the response-based calculated and gradient AC/A ratios. For 10 subjects, the correlations between predicted and measured dark vergence values were high. The prediction was better when using the gradient AC/A ratio.

Vitreous chamber elongation is responsible for myopia development in a young adult.

In this case report, we present 3 years of longitudinal, refractive component data for a young adult who became myopic and progressed in myopia (late-onset myopia, LOM) during that period. We found a high correlation between refractive error and axial length (AL). The axial elongation was a consequence of the change in the vitreous chamber depth (VCD). Furthermore, the change in AL and VCD corresponded quantitatively to the change in refractive error. Corneal curvature change was not correlated with refractive error change. These findings support the suggestion that VCD is the refractive component that changes in LOM development.

Accommodative vergence is driven by the phasic component of the accommodative controller.

Conflicting opinions exist as to whether the phasic (reflex) component alone or both the phasic and tonic (adaptive) components of the accommodation and vergence systems drive accommodative vergence and vergence accommodation crosslinks. In this study the dissociated phoria to a 2 D target was measured before and after accommodative adaptation to discriminate the two possibilities. Results showed a significant difference in the dark-focus of accommodation pre- and post-near-vision task, indicating that accommodative adaptation had occurred. No significant change occurred in dark-vergence or in the accommodative response to the 2 D target. However, a significant decrease was found in the dissociated phoria presumably because of decreased phasic accommodation and its stimulation of accommodative vergence after the adaptation. This result is consistent with a model in which the accommodative vergence crosslink is driven by phasic accommodation only.

Parameters of accommodative and vergence systems and the development of late-onset myopia.

PURPOSE: To evaluate whether the characteristics of the oculomotor system are related to the development of late-onset myopia. METHODS: Forty-four college students were followed for 2 to 3 years. When recruited, 33 of the 44 subjects had emmetropia whereas the remainder (N = 11) had late-onset myopia (LOM). For each subject, dark-focus, dark-vergence, response AC/A, and CA/C ratios, and manifest refraction were measured at 6-month intervals. RESULTS: The mean dark-focus and AC/A ratios for the subjects (N = 6) who started with emmetropia and became myopic were higher than for the subjects (N = 25) who remained emmetropic. These higher values presented before the refractions exceeded -0.50 D. Interestingly, 7 of 11 subjects with LOM whose myopia increased displayed higher mean AC/A and dark-vergence values and lower mean dark-focus values than the subjects who remained emmetropic. CONCLUSION: The lower dark-focus values found among subjects with LOM seems to be a consequence of the development of myopia. However, myopia might eventually develop in a person with emmetropia with a relatively high AC/A and/or dark-focus values. Therefore, AC/A and dark-focus values may be predictors of the development of myopia.

A method for correction of CA/C ratio based on linear model of accommodation and vergence.

Measurement of the response CA/C ratio has required that the target used to stimulate the vergence system provides no blur information to the accommodative system. Although several methods have been proposed to open the accommodative feedback loop, it is difficult to ensure that a vergence target produces no stimulus for accommodation. To avoid this problem, we have derived a formula based on a linear model of the accommodative and vergence systems that allows the CA/C ratio to be estimated when the accommodative loop is not opened completely. An experiment was conducted to verify the derived formula. Two targets, Snellen letters and a small point source, were used to provide different blur-inputs to the accommodative system. CA/C ratios were estimated from the formula using measures of accommodation and vergence obtained with these two targets for eight subjects and showed a high correlation. The formula, therefore, was shown to provide a consistent estimate of the CA/C even when the accommodative loop was not opened completely.

Illumination and errors in dispensing.

The relationship between the level of illumination and the prescription-dispensing error rate in a high-volume Army outpatient pharmacy was investigated. The prescription error rate was determined by direct, undisguised observation and retrospective prescription review under three levels of illumination (45, 102, and 146 foot-candles) during 21 consecutive weekdays. Illumination was controlled in the prescription-checking area of the pharmacy by using additional fluorescent lamps and filters. The three levels of illumination were randomly assigned to the 21 days to provide a total of 7 days of observations per level. The final sample consisted of 10,888 prescriptions dispensed by five pharmacists. The overall prescription error rate (including both content and labeling errors) was 3.39% (369 prescriptions). An illumination level of 146 foot-candles was associated with a significantly lower error rate (2.6%) than the baseline level of 45 foot-candles (3.8%). There was a linear relationship between each pharmacist's error rate and that pharmacist's corresponding daily prescription workload for all three illumination levels. The effect of the observer was minimal. The rate of prescription-dispensing errors was associated with the level of illumination. Ergonomics can affect the performance of professional tasks.