In the absence of mitogen, administration of Dexamethasone (Dex) induces apoptosis, or programmed-cell death in the Nb2 lymphoma cell. Addition of prolactin (Prl), on the other hand, blocks this effect. As a model for apoptosis, we were able to investigate this Dex-Prl interaction by means of a morphological approach: one that could be visualized under a light microscope. This approach allowed us to achieve several aims. First, we were able to develop a method of cell quantification befitting a morphological study based upon the hemacytometer. Second, with Trypan Blue exclusion, we were able to verify Dex/Prl-responsiveness in the Nb2 cells. Third, we were able to refine and characterize the TUNEL (Tdt-dependent dUTP-biotin Nick End Labeling) assay as a means of detecting apoptosis in both log phase and synchronized cells. With the synchronized cells, we observed that the time frame of apoptosis onset as measured by Trypan Blue and the TUNEL assay, occurred between 6 and 8 hours. Fourth, using immunocytochemistry (ICC), we were able to characterize and establish specificity of affinity purified polyclonal rabbit antibodies directed against the signal proteins, glucocorticoid receptor (GR), STATSb, NFkB and lkBα. Fifth, we were able to examine how these signal proteins changed in response to Dex treatment using ICC. According to our results, the percentage of positively stained cells for each of these signal proteins remained constant for each time point and treatment.

No description available.

Myocardial ischemia activates a phospholipase A2 that targets plasmalogen phospholipids and liberates 1-0-alkenyl-Iysoplasmenylcholine (LPLC) in preference to 1-0- acyl-Iysophosphatidylcholine (LPC). Although LPC is a pro arrhythmic ischemic metabolite, the effect of LPLC on cardiac electrophysiology is unknown. At the lowest doses investigated, LPLC induced spontaneous contractions in otherwise quiescent rabbit ventricular myocytes significantly faster than LPC. Spontaneous contractions developed with median times of 16.4 (n = 64), 27.4 (n = 36), and >60 min (n = 25) during exposure to 5, 2.5, and 1 JlM LPLC compared with 38.0 (n = 48) and >60 min (n = 29) for 5 and 2.5 JlM LPC, respectively. Median times for 10 JlM lysolipids were not different. To characterize the mechanism of spontaneous activity, membrane potential (Em) and whole-cell currents were measured. LPLC caused an abrupt and sustained depolarization of Em by z 50 m V and culminated in the loss of excitability (n = 7). Voltage-clamp analysis of steady-state currents revealed an inward current at the normal resting Em that reversed at - 18.5 ± 0.9 m V (n = 12). The reversal potential of this current was insensitive to Ca-channel blockade by Cd2+ (n = 3), or by lowering bath [Cl-]. However, a lO-fold reduction in bath [Na+] caused repolarization and reduced the inward current by 56.6 ± 3.6% at -83 m V (n = 4). In contrast, Na-channel blockade by tetrodotoxin (n = 4) or saxitoxin (n =3) failed to inhibit membrane depolarization or the current induced by LPLC. Two lanthanides were studied to determine if the LPLC current was mediated by stretch-activated channels (SACs). Gd3+ ( 100 IlM), a known SAC blocker, and La3+ (100 IlM), devoid of SAC blocking activity, inhibited the LPLC-induced current by 80.2 ± 8.3% (n = 7) and 80.7 ± 8.3 % (n = 6), respectively, at -83 mY. Exposure to hypertonic bathing medium and cell shrinkage failed to restore Em (n = 5) or inhibit the LPLC-induced current (n = 2), which confirmed that lanthanides were not acting through inhibition of SACs. Consistent with the effects on membrane current, pretreatment with 100 IlM Gd3+ or La3+ but not Cd2+, significantly delayed spontaneous activity in 5 IlM LPLC (median times: Gd3+, 55.4 min (n = 35); La3+, 53.0 min (n = 38); Cd2+, 17.4 min (n = 19)). Lanthanides increase phospholipid ordering and may oppose membrane perturbations induced by LPLC. LPLC may contribute to ventricular dysrhythmias during ischemia.

This investigation involved the functional characterization of four Nb2 sub lines (Nb2-U- 17, Nb2-l l , SFJCD l , and D5) for their mitogenic and apoptotic responses to DEX ± PRL treatment. Many protein factors have been implicated to be crucial in controlling the apoptotic and mitogenic pathways. In conjunction with functional studies, an immunocytochemical investigation of four protein signals (NFKB, IKBa, STAT 5b, and the GR) was undertaken in an attempt to establish a relationship between the functional responsiveness of a given cell line and the concentration of a particular protein marker. Comparison of the functional data obtained for the four lines reveals marked differences in behavior in response to DEX ± PRL. The Nb2-l l and U-17 sublines were dependent upon prolactin for proliferation and were sensitive to DEX induced cytolysis/apoptosis in the absence of PRL. Co-incubation of DEX and PRL resulted in both an inhibition of apoptosis by PRL and an inhibition of mitogenesis by DEX. On the other hand, the SFJCDI (SF) and 05 sublines proliferated in the absence of prolactin and were resistant. to the anti-mitogenic and cytolytic/apoptotic effects of DEX. The differences in functional behavior between the mitogen-dependent and -independent cell lines could not be correlated with the expression of a particular protein marker.

Consistent with previous studies, we demonstrated that dexamethasone (Dex) caused cytolysis/apoptosis in log phase Nb2 lymphoma cells, while prolactin (Prl) inhibited this effect. The Nb2 model was used to investigate the mechanisms of apoptosis control with the aid of immunocytochemistry (ICC). We established with absorption the specificity of staining due to Fas, Fas Ligand, Bcl-2, and Bax antibodies (the specificity of anti-p53 could not be verified). Dex-induced cytolysis/apoptosis was detected in synchronized (G⁰/G¹) cells after 6 and 8 hours of Dex exposure. A novel, computerized technique was used to quantitate the proportion of cells immunostained for the signals of interest in Nb2 cells in log phase a G⁰/G¹ after up to 8 hours of Dex exposure. We observed Fas, Fas Ligand, Bcl-2, Bax, and p53 in high proportions (72%-86%) of log phase Nb2 cells. Neither synchrony in G⁰/G¹ nor exposure of synchronized cells to Dex for up to 8 hours altered the proportion of immunostained cells. This study has raised provocative issues regarding the resistance of Nb2 cells to Fas mediated apoptosis, the phenotype of the p53 protein in Nb2 cells, and the possible interaction of various signals that modulate apoptosis.

The patch clamp method was used to evaluate the effects of 3,5,3'-triiodo-L-thyronine (T3) and carboxyl modification on adult rabbit ventricular Na+ channels. In contrast to TTX-sensitive Na+ channels, Ca2+ block of cardiac Na+ channels was not prevented by selective carboxyl modification by trimethyloxonium (TMO) or water soluble carbodiimide (WSC). In 2 mM Ca2+, TMO-treated patches exhibited 3 discrete conductance (γNa) levels. An abbreviation of mean open time (MOT) accompanied each decrease in γNa. The effects on channel gating of elevating external Ca2+ differed from those of TMO pretreatment. Ensemble averages after TMO showed a shortening of the time to peak current and an acceleration of the rate of current decay. WSC caused a decrease in γNa and an abbreviation of MOT at all potentials tested. We conclude that alteration of the surface potential by a single carboxyl modification is inadequate to explain the effects of TMO and WSC. Physiological concentrations of T3 increased bursting as measured by the ratio of long events (LE) to the total number of events. In the cell-attached patch configuration, addition of 5 nM T3 to the pipette increased the %LE at all potentials examined. The increase had a biphasic voltage-dependence and peaked at -50 mV. A similar increase in the %LE occurred with 50 nM T3 suggesting saturation at ≤5 nM. LEs sometimes were grouped into runs, but the more usual pattern suggested that modal shifts occurred in ~1 s. Addition of T3 to the bath but not the pipette in cell-attached patches failed to alter the MOT, unitary current, or %LE. Na+ channel gating also was unaffected by patch excision or by addition of T3 to the cytoplasmic face of inside-out patches. Nevertheless, with T3 in the pipette, patch excision to the inside-out configuration caused a dramatic increase in the %LE, especially near the threshold potential, and an increase in the MOT. These results suggested that T3 was not membrane permeable during the time scale of the experiments and that T3's action required close proximity to the extracellular face of the Na+ channel.

Until the mid to late 1800's, the cerebral hemispheres were considered to be only the sites of mentation and intellectual activity. On the basis of his observations of epileptic patients, HughIings Jackson (cited from Walshe, l935a) theorized that the cerebral hemispheres were also sites of motor control and sensory experience. The electrical excitability of the cerebrum was first demonstrated by Fritsch and Hitzig in 1870. Since then the motor representation of the various muscles has been mapped out and the types of movement in response to stimulation of the motor cortex and the pyramidal tract have been thoroughly studied. Mammalian muscles contain sensory receptors which supply the central nervous system information on muscle length and rate of change of muscle length. One important feature of muscle spindle receptors is that they receive an efferent (gamma) innervation from the central nervous system through which their sensitivity to stretch can be changed. There is little direct evidence for pyramidal and cortical control of the gamma motor system on the basis of experiments using electrical stimulation. Most of the evidence for the control of the gamma motor system by the cortex and pyramidal tract stems from studies in which the motor cortex or pyramidal tract are ablated or lesioned and the resulting changes in posture are observed. The basis of these posture changes is the stretch or myotatic reflex (Liddell and Sherrington, 1924, 1925). When the muscle belly or tendon is lengthened, the receptor region of the muscle spindle is stretched. This results in a volley of Ia impulses being sent into the spinal cord to the motoneurons of the stretched muscle. As a result of the Ia excitation, the motoneurons discharge causing the stretched muscle to contract, tending to return to its original length. Sherrington (1898, 1915, 1924) demonstrated the stretch reflex to be the basis of posture and resistance to gravity. Here the stretch is due to gravity and the resulting contraction of the extensor muscles results in the maintenance of an upright posture. The sensitivity of the spindle to stretch, hence the response of the muscles to stretch, can be influenced by the presence or absence of gamma motor activity. An increase of gamma motor activity can result in an increased stretch reflex and pathologically to rigidity or spasticity, while a decrease in gamma activity can result in hypotonus. The literature in this area is confusing. The clinical data suffers from the lack of precision in lesion localization and absence of detailed histological follow-up of the patients. Though the ability to produce more discrete lesions is greater in experimental animals, damage to areas peripheral to the intended lesion site cannot be prevented. Thus, these lesions are not truly restricted to a well defined site. Furthermore, in many studies there have not been adequate descriptions of the areas lesioned or ablated (Fulton, 1935). The purpose of the present experiments was to study the effect of electrical stimulation of the motor cortex and pyramidal tract on the gamma motor system of the cat.

BACKGROUND: The growth in popularity of women's soccer has led to an increased interest in the physical, physiological, and technical demands for these athletes. To meet these demands, optimal preparation and recovery are necessary. One growing area of interest in athletic performance is the role that sleep may have in preparation and recovery. However, details about sport-specific benefits of sleep are limited, particularly in female collegiate athletes. Athletes in the collegiate setting may suffer from lack of sleep due to the stresses of academics and athletics. Moreover, measurement of sleep in elite college soccer players using actigraphy does not exist in the literature. PURPOSE: To evaluate the relationship between sleep quantity and quality and soccer-specific performance variables in an elite group of female soccer players. METHODS: Eight NCAA college-aged competitive Division I women's soccer players (18-23 yrs) participated in the study. Global Positioning Systems (GPS), heart rate monitoring and video analysis technologies were used during matches along with 24-hour actigraphy through the season. Actigraphy was also used to measure sleep quantity and quality. Data were collected for all 26 matches but only four competitive matches were included in the analysis as they met the following requirements: an evening match beginning at 1900 EST, time zones were not traveled across, goal differential was no more than two points (indicating a high level of competition) and for players' data to be included they must have played at least 45 minutes of the 90-minute match. The night prior to the match was included for the data analyses of sleep quantity and quality. A multivariate analysis of variance (MANOVA) was utilized to determine whether the vectors of the means in groups of variables were significant. Paired t-tests were used to analyze if differences in variables of performance existed after the "best" and "worst" nights of sleep for quantity and quality. Significance was set at p[less than]0.05. RESULTS: Mean sleep quantity and quality for the "best" (575.0 ± 38.4 minutes, 91.9 ± 2.6% of time in bed spent sleeping) and "worst" (416 ± 57.6 minutes, 76.2 ± 12.1% of time in bed spent sleeping) nights were significantly different. The MANOVAs were not significantly different for the physiological and physical variables for quantity and quality of sleep. No differences in performance variables were observed after "best" and "worst" quantity sleep matches. However, differences existed between "best" and "worst" quality of sleep. Percent time spent exercising above 85% of the maximal heart rate (HRmax) was significantly lower after the "best" night of sleep (30.2 ± 13.5 vs. 47.9 ± 24.3%). Heart rate exertion was higher after the "best" night of sleep (518.5 ± 193.1 vs. 387.6 ± 148.9 AU) meaning the athletes were exercising at higher heart rates throughout the match without spending as much time in the anaerobic zone ([greater than]85%HRmax). High metabolic load distance (distance running at speeds greater than 19 km/hr and distance accelerating or decelerating quickly ([greater than]2 m/s^2) was lower after the "best" quality night (11.8 ± 3.6 vs. 16.3 ± 6.0 yds/min) and the number of decelerations was higher after the "best" quality night (69.7 ± 28.1 vs. 50.6 ± 25.9) indicating less stress on the body. CONCLUSION: Quality of sleep is important for reducing the time spent exercising in the anaerobic zone ([greater than]85% HRmax). However the time spent exercising at high heart rates below the ventilatory threshold may be increased after a night of better sleep quality, indicating an increased aerobic capacity during a competitive women's soccer match. / A Thesis submitted to the Department of Nutrition, Food and Exercise Sciences in partial fulfillment of the Master of Science. / Fall Semester 2015. / October 21, 2015. / Performance, Sleep, Soccer / Includes bibliographical references. / Lynn Panton, Professor Directing Thesis; Mark Kasper, Committee Member; Michael Ormsbee, Committee Member; Gershon Tenenbaum, Committee Member.

BACKGROUND: Frailty syndrome is a geriatric medical condition characterized by diminished muscular strength and endurance, weight loss, and weakened physiologic function. Frailty syndrome tends to manifest itself amongst morbidities and, consequently, individual health complications are regularly targeted by clinicians with the physical state of frailty often left untreated. A majority of nursing home residents are believed to suffer from frailty syndrome; therefore, this group of older adults deserves our attention. Unloaded whole body vibration training (WBVT) has been shown to improve strength and functional performance in higher functioning older adults without frailty syndrome. PURPOSE: To determine and compare the effects of 12 weeks of WBVT to standard care alone (CON) on body composition, strength, functional performance, and inflammation in 20 (16 female) pre-frail and frail skilled nursing home residents (82 ± 5 years). METHODS: This was a non-randomized controlled trial. Participants were recruited from three skilled nursing facilities in Tallahassee, FL. Participants (WBVT: n=14; CON: n=11) were screened for frailty syndrome using the FRAIL scale. Handgrip (HG) and isometric knee extension strength (KE) were measured using a hand and mechanical push-pull dynamometer. Bioelectrical impedance was used to determine lean mass (LM), fat mass (FM), skeletal muscle index (SMI), and phase angle (PA; a measure of tissue health). Inflammation was assessed using an enzyme-linked immunosorbent assay to measure resting serum concentrations of C-reactive protein (CRP). The short physical performance battery (SPPB) and timed up-and-go (TUG) were used to assess functionality. Participants were assigned to either 12 weeks of WBVT (2x/wk) or CON. WBVT consisted of 3x10 of 4 lower body exercises with 50 seconds of vertical vibration (25-40 Hz) per set. CON continued with day-to-day activities and followed doctor’s orders. One-way analysis of variance (ANOVA) was used to analyze baseline data between the WBVT and CON groups. Dependent variables were analyzed using a 2 x 2 (group x time) factorial ANOVA with repeated measures on the last factor. When a significant group-by-time interaction and/or time effect was identified, between-groups and within-group comparisons were performed using independent and paired t-tests. Significance was set at p≤0.05. RESULTS: Twenty participants completed the intervention (WBVT: n=10; CON: n=10). The FRAIL Scale identified 5 participants as pre-frail (WBVT: n=4) and 15 as frail (CON: n=9). Sarcopenia (low SMI and HG or SPPB) was identified in 9 participants (WBVT: n=6), of which 4 were obese (WBVT: n=3). BMI classification ranged from underweight to stage-3 obesity (15.3-38.2 kg/m2). Hypertension (85%), depression (75%), Alzheimer’s or dementia (50%), and diabetes mellitus (55%) were the most frequent medical conditions reported. Nineteen participants were treated with polypharmacy (>5 drugs) and all required assistive devices for ambulation. All WBVT participants completed the 24 exercise sessions. There were no differences between groups in baseline measures of body composition, strength, functional performance, and inflammation. There was no significant change in LM, FM, PA, or CRP in either group. There were significant time effects on body mass (F1,18=8.869, p=0.008, η2=0.330) and BMI (F1,18, p=0.014, η2=0.293). The standard care group increased their body mass (p=0.022) and BMI (p=0.028), but neither body mass nor BMI were different between groups post-intervention (p>0.05). There was a significant group-by-time interaction (F1,18=5.434, p=0.032, η2=0.232) for KE. WBVT significantly improved KE (p=0.003), but KE was not different between groups post-intervention (p>0.05). There was a significant group-by-time interaction for SPPB performance (F1,18=4.84, p=0.041, η2 = 0.212). Total SPPB score improved by 15.6% following WBVT (p=0.089) with a magnitude of change in the WBVT (∆ SPPB=+0.7 units) that was greater (p=0.041) than CON (∆ SPPB=-0.4 units). CONCLUSION: WBVT in pre-frail and frail skilled nursing home residents was well tolerated and occurred without adverse health complications. WBVT can be used in skilled nursing facilities to counteract losses in leg strength and some measures of physical function. WBVT interventions of longer frequency and duration could demonstrate to be useful for greater improvements in strength and functional performance. / A Dissertation submitted to the Department of Nutrition, Food & Exercise Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2017. / June 23, 2017. / Aging, Frailty, Functional Performance, Older Adults, Sarcopenia, Whole Body Vibration / Includes bibliographical references. / Lynn B. Panton, Professor Directing Dissertation; Robert Contreras, University Representative; Jeong-Su Kim, Committee Member; Arturo Figueroa, Committee Member.

Purpose. The primary purpose was to determine the effect of sleep time on performance during a 3-day multistage ultra-endurance triathlon (stage 1: 10km swim, 144.8km bike; stage 2: 275.8km bike; stage 3: 84.4km run). Methods. Eighteen triathletes (age: 37±7.9y; height: 175±7cm; weight: 70±9kg) partook in sleep analysis pre, during, and post triathlon using an actigraphy wristband. Participants wore the band to record sleep time for five days (1-2 days pre-race, 3 race days, 1-day post-race), except during racing. Bands were collected before each stage to download the previous night’s data, then re-distributed after each stage. Performance times were recorded after each stage and following total completion of the race. The data were analyzed via linear regression. Results. Using a one-way repeated measures analysis of variance, total minutes of sleep (mean±SD; pre-race: 393.9±81.1min, pre-stage 1: 342.0±90.2min, pre-stage 2: 347.5±54.6min, pre-stage 3: 299.7±107.0min, post-race: 308.8±86.3min) significantly decreased over time (p<0.05). Using a hierarchal regression, a p value approaching significance was found in pre-stage 2, sleep latency, when added to the prediction model of stage 2 performance. This p value approaching significance may have explained 6.1% of the variation in stage 2 performance (R2=0.061, p=0.064). A p-value approaching significance was found in stage 1 performance time when added to the prediction model of pre-stage 2 sleep latency. This p value approaching significance may have explained 10.3% of the variation in pre-stage 2 sleep latency (R2=0.103, p=0.58). Finally, significance was found in stage 2 performance time, when added to the prediction model of pre-stage 3 minutes of sleep. This model explained 48.1% of the variance in pre-stage 3 minutes of sleep (R2=0.48, p=0.002). Total race sleep time (Pre-stage 1, 2, and 3) was averaged; 33% of the variation in total finishing time can be predicted by average total racing sleep time (R2=0.33, p=0.015). No additional relationships were seen. A cutoff value was found at 401.6 min of average total race-night sleep time, indicating the top 25% of race finishers slept for ≥401.6 min. Conclusions. We found at specific time points, sleep latency may have been associated with changes in performance time, and exercise performance may have been associated with changes in minutes of sleep and sleep latency. Additionally, based on our results, average total race-night sleep time of roughly 402 min (6.7h/night) leads to faster finishing time in the Ultraman Florida. / A Thesis submitted to the Department of Nutrition, Food and Exercise Sciences in partial fulfillment of the requirements for the degree of Master of Science. / Spring Semester 2018. / March 21, 2018. / Includes bibliographical references. / Michael Ormsbee, Professor Directing Thesis; Lynn Panton, Committee Member; Graig Chow, Committee Member.