The effect of exercise on anxiety- and depression-like behavior of aged rats.

We investigated the effects of exercise in multiple sessions on anxiety- and depression-like behavior during aging, and the role of serotonin and serotonin 1A receptors in this process. Both 24-month-old (aged) and 6-month-old (adult) female rats were divided into five groups; aged control, adult control, aged + serotonin re-uptake inhibitors (SSRIs), aged + exercise, and aged + SSRIs + exercise. After exercise, all groups were evaluated using the open field arena, elevated plus maze and forced swim tests. We assessed serum corticosterone levels; number of amygdala, hippocampus and prefrontal cortex cells; tissue serotonin and serotonin 1A (5-HT1A) levels. In the open field test, aged rats exhibited a significant increase in locomotor activity compared to the SSRIs and SSRIs + exercise groups. During the elevated plus maze test, aged rats were observed less frequently in the open arms of assembly compared to adults. The duration increased in the exercise group and remained unchanged in the SSRIs group. In the forced swim test, the aged rats were more immobile compared to adults; no change was observed in the immobility time between these groups. The tissue serotonin levels in amygdala and hippocampus were higher in SSRIs + exercise group compared to the aged, exercised and SSRIs groups. The number of cells in the hippocampus, prefrontal cortex and amygdala decreased in the aged group compared to adult rats; increased numbers of cell were observed in exercise, SSRIs and SSRIs + exercise groups compared to aged rats. Exercise in multiple sessions may increase the number of cells in the hippocampus, prefrontal cortex and amygdala, which may reduce senile anxiety and depression. Also, serotonin and serotonin 1A receptors may play role in depression-like behavior.

Effects of smoking on thiol/disulfide homeostasis.

OBJECTIVE: Cigarette smoking is an important risk factor for many diseases. This study aimed to evaluate whether cigarette smoking is associated with changes in the thiol/disulfide homeostasis (TDH), a novel biomarker of systemic oxidative stress. PATIENTS AND METHODS: Eighty-four smokers and 86 non-smoking healthy volunteers were enrolled. Serum native thiol, disulfide and total thiol levels, disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios were analyzed using a new colorimetric method. Carbon monoxide (CO) levels were measured by a piCO smokerlyzer instrument. RESULTS: The native, total, and native/total thiol levels of smoking patients were significantly lower (p<0.001 for each), and disulfide, disulfide/native thiol, and disulfide/total thiol levels were significantly higher in smokers than the healthy controls (p<0.001 for each). The CO levels of all study participants were negatively correlated with native thiol (r= -0.627, p<0.001), total thiol (r= -0.569, p<0.001), native thiol/total thiol (r= -0.515, p<0.001), and positively correlated with disulfide (r=0.398, p<0.001), disulfide/native thiol (r=0.515, p<0.001) and disulfide/total thiol (r=0.515, p<0.001) levels. CONCLUSIONS: To our knowledge, this investigation is the first in the literature that investigated TDH in cigarette smokers. Our results show that cigarette smoking may lead to oxidative stress and TDH shifts through disulfide side compared to the healthy group. Further studies with larger sample size are needed to confirm our results for showing the changes in TDH to contribute to the clinical practice.

The effect of 8-week different-intensity walking exercises on serum hepcidin, IL-6, and iron metabolism in pre-menopausal women.

Objective Hepcidin may be an important mediator in exercise-induced iron deficiency. Despite the studies investigating acute exercise effects on hepcidin and markers of iron metabolism, we found no studies examining the chronic effects of walking exercises (WE) on hepcidin and markers of iron metabolism in premenopausal women. The chronic effects of two 8-week different-intensity WE on hepcidin, interleukin 6 (IL-6), and markers of iron metabolism in pre-menopausal women were examined. Methods Exercise groups (EG) [moderate tempo walking group (MTWG), n = 11; brisk walking group (BWG), n = 11] walked 3 days/week, starting from 30 to 51 min. Control group (CG; n = 8) did not perform any exercises. BWG walked at ∼70%-75%; MTWG at ∼50%-55% of HRRmax. VO2max, hepcidin, IL-6, and iron metabolism markers were determined before and after the intervention. Results VO2max increased in both EGs, favoring the BWG. Hepcidin increased in the BWG (p < 0.01) and CG (p < 0.05). IL-6 decreased in the BWG and the MTWG (p < 0.05; p < 0.01). While iron, ferritin, transferrin, and transferrin saturation levels did not change in any group, total iron binding capacity (p < 0.05), red blood cells (p < 0.05), and hematocrit (p < 0.01) increased only in the BWG. Conclusion Both WE types may be useful to prevent inflammation. However, brisk walking is advisable due to the positive changes in VO2max and some iron metabolism parameters, which may contribute to prevent iron deficiency. The increase in hepcidin levels remains unclear and necessitates further studies.

Effects of voluntary and involuntary exercise on cognitive functions, and VEGF and BDNF levels in adolescent rats.

Regular treadmill running during adolescence improves learning and memory in rats. During adolescence, the baseline level of stress is thought to be greater than during other periods of life. We investigated the effects of voluntary and involuntary exercise on the prefrontal cortex and hippocampus, vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF) levels, and spatial learning, memory and anxiety in adolescent male and female rats. The voluntary exercise group was given free access to a running wheel for 6 weeks. The involuntary exercise group was forced to run on a treadmill for 30 min at 8 m/min 5 days/week for 6 weeks. Improved learning was demonstrated in both exercise groups compared to controls. Neuron density in the CA1 region of the hippocampus, dentate gyrus and prefrontal cortex were increased. Hippocampal VEGF and BDNF levels were increased in both exercise groups compared to controls. In females, anxiety and corticosterone levels were decreased; BDNF and VEGF levels were higher in the voluntary exercise group than in the involuntary exercise group. The adolescent hippocampus is affected favorably by regular exercise. Although no difference was found in anxiety levels as a result of involuntary exercise in males, females showed increased anxiety levels, and decreased VEGF and BDNF levels in the prefrontal cortex after involuntary exercise.

The effects of resveratrol on chronic constriction injury of sciatic nerve in rats.

The aim of this study was to investigate the effects of resveratrol (RVT) in chronic constriction injury (CCI) of sciatic nerve by behavioral, histomorphological and immunohistochemical evaluations in rats. In this study, male Wistar rats were divided into three groups: sham (n=7), CCI+saline (n=7) and CCI+RVT (n=7). After inducing CCI, treatment with 10mg/kg/day of RVT or saline for 14 days was given. Locomotor function was assessed with rota-rod and open field tests. Morphologic alterations of sciatic nerve were assessed histologically by light and electron microscopy. Immunohistochemistry for insulin-like growth factor-1 (IGF-1) were performed. RVT treatment prevented motor impairment and histomorphological alterations caused by chronic constriction injury of sciatic nerve. IGF-1 immunoreactivity was significantly higher in RVT treated group then CCI induced group and positive correlated with morphometric parameters. These results indicate that RVT may reduce CCI induced damage and this effect may be mediated through the restoration of IGF-1 immunoreactivity.

Anxiety- and depression-like behavior are correlated with leptin and leptin receptor expression in prefrontal cortex of streptozotocin-induced diabetic rats.

Anxiety and depression are common in diabetics. Diabetes also may cause reduced leptin levels in the blood. We investigated the relation between diabetes induced anxiety- and depression-like behavior, and leptin and leptin receptor expression levels in diabetic rats. The anxiety- and depression-like behaviors of rats were assessed 4 weeks after intraperitoneal injection of streptozotocin. Diabetic rats exhibited greater anxiety-like behavior; they spent more time in closed branches of the elevated plus maze test and less time in the center cells of the open field arena. Increased depression-like behavior was observed in diabetic rats using the Porsolt swim test. Prefrontal cortex (PFC), blood leptin levels and PFC neuron numbers were decreased, and leptin receptor expression and apoptosis were increased in diabetic rats. Blood corticosterone levels also were increased in diabetic rats. These results indicate that reduction of leptin up-regulates leptin receptor expression and may affect PFC neurons, which eventually triggers anxiety- and depression-like behaviors in diabetic rats.

Wireless transmission of ultrasonic waveforms for monitoring drug tablet properties and defects.

The geometric and mechanical properties of pharmaceutical materials are crucial to their structural, functional and therapeutic effectiveness. The implementation of automated and convenient quality monitoring procedures is an attempt to balance control of quality against the level of testing; within acceptable levels of probability and costs. The capability of rapid/extensive inspections with minimal time and manufacturing interruption make non-contact quality monitoring systems a desirable approach to optimize this balance. In the current study, a wireless transceiver proof of concept system developed for the real-time quality monitoring of tablets during compaction is presented and demonstrated. The effectiveness of ultrasonic wave transmission through the punch-tablet interface is the boundary condition that dictates the viability of the acoustic in-die compaction monitoring approach. These measurements in the current experimental set-up can be used in determining various mechanical and geometric properties of a compact, such as the tablet thickness, mass density, elasticity and/or integrity of the tablet core, and bonding quality between layers depending on the given parameters, as it is compacted. In the current study, it is demonstrated that the reflection of an ultrasonic pulse generated by a transducer embedded in an upper punch from the lower punch-tablet interface can be acquired by the same transducer in the upper punch and the analog waveform can be transmitted to a computer by means of wireless communications for further signal processing and property extraction. The evolution of apparent Young's moduli of a powder bed during a full-compaction cycle is derived from the ultrasonic time of flight of an acoustic waveform acquired during compaction in-die.

Non-destructive determination of anisotropic mechanical properties of pharmaceutical solid dosage forms.

The mechanical property anisotropy of compacts made from four commercially available pharmaceutical excipient powders (microcrystalline cellulose, lactose monohydrate, ascorbic acid, and aspartame) was evaluated. The speed of pressure (longitudinal) waves in the uni-axially compressed cubic compacts of each excipient in the three principle directions was determined using a contact ultrasonic method. Average Young's moduli of each compact in the axial (x) and radial (y and z) directions were characterized. The contact ultrasonic measurements revealed that average Young's modulus values vary with different testing orientations which indicate Young's modulus anisotropy in the compacts. The extent of Young's modulus anisotropy was quantified by using a dimensionless ratio and was found to be significantly different for each material (microcrystalline cellulose>lactose>aspartame>ascorbic acid). It is also observed that using the presented contact method, compacts at high solid fraction (0.857-0.859) could be differentiated than those at the solid fraction of 0.85 in their groups. The presented contact ultrasonic method is an attractive tool since it has the advantages of being sensitive to solid fraction ratio, non-destructive, requiring small amount of material and rapid. It is noteworthy that, since the approach provides insight into the performance of common pharmaceutical materials and fosters increased process knowledge, it can be applied to broaden the understanding of the effect of the mechanical properties on the performance (e.g., disintegration profiles) of solid oral dosage forms.

Continuous hypoxic culturing maintains activation of Notch and allows long-term propagation of human embryonic stem cells without spontaneous differentiation.

OBJECTIVE: The maintenance of pluripotency of human embryonic stem cells (hESCs) requires a high efficiency of self-renewal. During in vitro propagation, however, hESCs have a propensity to differentiate spontaneously. In this study, we assessed the nature of hESC responses to hypoxic conditions. MATERIALS AND METHODS: Human embryonic stem cells were grown in normoxic and hypoxic conditions, and the cells expressing Oct4 and stage-specific embryonic antigen-1 were identified by indirect immunofluorescence. The transcriptional expression of Nanog, Notch1, and Oct4 was determined by a real-time reverse transcription-polymerase chain reaction, and the inhibition of Notch-mediated signalling was achieved with a gamma-secretase inhibitor. RESULTS: In contrast to culture at 21% oxygen, where the colonies displayed a marked degree of differentiation, we found that during exposure to 5% oxygen, the hESC colonies displayed a homogenous and flat morphology that was consistent with the presence of Oct4-positive phenotype, indicating no spontaneous differentiation. When cultured at 5% oxygen for either 4 weeks or up to 18 months, high levels of Nanog and Notch1 transcriptional expression were detected, albeit the expression was significantly lower during longer exposure. The suppression of differentiation was rapidly reversed on transfer of the hypoxic cultures to normoxic conditions. Looking into the molecular mechanisms of the maintenance of self-renewal at low oxygen tensions, we found that inhibition of Notch signalling fully abrogated the hypoxic induction of undifferentiated phenotype. CONCLUSION: Our data, thus, indicate that hypoxic exposure has the capacity to sustain long-term self-renewal of hESCs and that this effect is mediated through activation of Notch.

Kinetic analysis of recombinant mammalian alpha(1) and alpha(1)beta glycine receptor channels.

To analyze the influence of the beta-subunit on the kinetic properties of GlyR channel currents, alpha(1)-subunits and alpha(1)beta-subunits were transiently expressed in HEK 293 cells. A piezo dimorph was used for fast application of glycine to outside-out patches. The rise time of activation was dose dependent for both receptors and decreased with increasing glycine concentrations. Subunit composition had no effect on the time course of activation. Coexpression of alpha(1)- and beta-subunits resulted in a significantly lower EC(50) and a reduced slope of the dose-response curve of glycine compared with expression of alpha(1)-subunits alone. For both receptor subtypes, the time course of desensitization was concentration dependent. Desensitization was best fitted with a single time constant at 10-30 micro M, with two at 0.1 mM, and at saturating concentrations (0.3-3 mM) with three time constants. Desensitization of homomeric alpha(1)-receptor channels was significantly slower than that of alpha(1)beta-receptor channels. The time course of current decay after the end of glycine pulses was tested at different pulse durations of 1 mM glycine. It was best fitted with two time constants for both alpha(1) and alpha(1)beta GlyR channels, and increased significantly with increasing pulse duration.

Interferon-gamma cooperates with retinoic acid and phorbol ester to induce differentiation and growth inhibition of human neuroblastoma cells.

The prognosis of patients with advanced stages of neuroblastoma with N-myc amplification remains poor despite escalated therapy, a situation that has called for alternative therapeutic approaches. Neuroblastoma cells, which represent immature peripheral neuronal cells, treated with certain physiologic and nonphysiologic agents such as retinoic acid (RA), phorbol esters and interferons (IFN) in vitro undergo cellular differentiation and stop to divide, a process that mimics normal neuronal development. Such "differentiation therapy" using RA after autologous bone marrow transplantation has recently given encouraging results in neuroblastoma patients with advanced disease. Considering approaches for improved differentiation therapy, we investigated possible synergistic effects of combining agents known to influence neuroblastoma growth and differentiation in vitro. Our results show that combined treatment with IFN-gamma and RA or the phorbol ester 12-O-tetradecanoyl-phorbol acetate (TPA) had synergistic or enhancing effects on morphologic differentiation and neurite outgrowth in 5 of 5 neuroblastoma cell lines, 3 of which expressed very high levels of N-myc mRNA due to N-myc amplification. The combinations RA+IFN-gamma or TPA+IFN-gamma also enhanced induced growth inhibition in all 5 cell lines, in several cases resulting in complete growth arrest under conditions where cells stimulated with either agent alone continued to grow. The phenotypic effects of the combined RA+IFN-gamma or TPA+IFN-gamma treatments were in most, but not all, investigated cases accompanied by moderate reductions in N-myc expression, suggesting that the cooperative signals may counteract N-Myc activity at several levels. The cooperativity between IFN-gamma and other differentiation signals may be relevant for approaches to improve the therapy for high-risk neuroblastoma with N-myc-amplification.

c-Myc hot spot mutations in lymphomas result in inefficient ubiquitination and decreased proteasome-mediated turnover.

The c-myc proto-oncogene encodes a short-lived transcription factor that plays an important role in cell cycle regulation, differentiation and apoptosis. c-myc is often rearranged in tumors resulting in deregulated expression. In addition, mutations in the coding region of c-myc are frequently found in human lymphomas, a hot spot being the Thr58 phosphorylation site, a mutation shown to enhance the transforming capacity of c-Myc. It is, however, still unclear in what way this mutation affects c-Myc activity. Our results show that proteasome-mediated turnover of c-Myc is substantially impaired in Burkitt's lymphoma cells with mutated Thr58 or other mutations that abolish Thr58 phosphorylation, whereas endogenous or ectopically expressed wild type c-Myc proteins turn over at normal rates in these cells. Myc Thr58 mutants expressed ectopically in other cell types also exhibit reduced proteasome-mediated degradation, which correlates with a substantial decrease in their ubiquitination. These results suggest that ubiquitin/proteasome-mediated degradation of c-Myc is triggered by Thr58 phosphorylation revealing a new important level of control of c-Myc activity. Mutation of Thr58 in lymphoma thus escapes this regulation resulting in accumulation of c-Myc protein, likely as part of the tumor progression. (Blood. 2000;95:2104-2110)