Warm-Up Intensity and Time Course Effects on Jump Performance.

Jump performance is affected by warm-up intensity and body temperature, but the time course effects have not been thoroughly investigated. The purpose of this study was to investigate time course effects on jump performance after warm-up at different intensities. Nine male athletes (age: 20.9 ± 1.0 years; height: 1.75 ± 0.03 m; weight: 66.4 ± 6.3 kg; mean ± SD) volunteered for this study. The participants performed three warm-ups at different intensities: 15 min at 80% VO2 max, 15 min at 60% VO2 max, and no warm-up (control). After each warm-up, counter movement jump (CMJ) height, vastus lateralis temperature, heart rate and subjective fatigue level were measured at three intervals: immediately after warm-up, 10 min after, and 20 min after, respectively. Significant main effects and interactions were found for muscle temperature (intensity: p < 0.01, η2p = 0.909; time: p < 0.01, η2p = 0.898; interaction: p < 0.01, η2p = 0.917). There was a significant increase of muscle temperature from the baseline after warm-up, which lasted for 20 min after warm-up with 80% VO2 max and 60% VO2 max (p < 0.01). Muscle temperature was significantly higher with warm-up at 80% VO2 max than other conditions (P < 0.01). Significant main effects and interactions for CMJ height were found (intensity: p < 0.01, η2p = 0.762; time: p < 0.01, η2p = 0.810; interaction: p < 0.01, η2p = 0.696). Compared with the control conditions, CMJ height after 80% VO2 max and 60% VO2 max warm-ups were significantly higher (p < 0.01 and p < 0.05, respectively). CMJ height at 20 min after warm-up was significantly higher for 80% VO2 max warm-up than for 60% VO2 max warm-up (p < 0.01). However, CMJ height at 10 min after 60% VO2 max warm-up was not significantly different from the baseline (p < 0.05). These results showed that both high and moderate intensity warm-up can maintain an increase in muscle temperature for 20 min. Jump performance after high-intensity warm-up was increased for 20 min compared to a moderate intensity warm-up.

Warm-Up Intensity and Time-Course Effects on Jump Height under Cold Conditions.

With this study, we aimed to investigate the effects of different warm-up intensities on counter-movement jump (CMJ) performance over time under cold conditions. Eleven male collegiate athletes volunteered. The participants performed high-intensity warm-up (HWU) at 80% VO2max and moderate-intensity warm-up (MWU) at 60% VO2max for 15 min on a bicycle ergometer in a laboratory room at 10 °C. CMJ height, vastus lateralis muscle temperature, heart rate, and perceived fatigue were measured before warm-up (Pre), immediately after (Post 0), 10 min after (Post 10), and 20 min after (Post 20). Significant main effects and interactions were found for CMJ height (time, p < 0.001 and ηp2 = 0.859; interaction, p = 0.007 and ηp2 = 0.327). HWU significantly increased CMJ height at Post 0 to Post 20 compared to that at Pre (p < 0.01), whereas MWU increased CMJ height at Post 0 only compared to that at Pre (p < 0.001). The results indicate that HWU achieved an increase in CMJ height for 20 min. MWU changed CMJ height instantly, but the change did not last compared to HWU in a cold environment.

Clinical significance of thallium-201 SPECT after postoperative radiotherapy in patients with glioblastoma multiforme.

To assess the clinical significance of 201Tl-SPECT after postoperative radiotherapy in patients with glioblastoma multiforme (GM). Eighteen patients with macroscopically residual GM who underwent 201Tl-SPECT just after postoperative radiotherapy were analyzed. Fifteen patients (83%) received radiotherapy with a total dose of 60 Gy in conventional fractionation, and the remaining three patients were treated with 72 Gy with hyperfractionation schedules. Sixteen patients (89%) were treated with chemotherapy that consisted of procarbazine, nimustine (ACNU) and vincristine. Concerning 201Tl-SPECT, we calculated the radioactivity ratio of the tumors to contralateral normal brain (T/N ratio) on early and delayed images after 111 MBq 201Tl chloride injections. The median follow-up of all 18 patients was 14.7 months (range, 2.7-38.0 months). At the time of this analysis, 15 patients (83%) had died, and the 1-year overall survival and the median survival time were 67% and 16.2 months, respectively. Fifteen patients (83%) had disease recurrence, and the 1-year progression-free survival (PFS) rate and the median time to progression in all 18 patients were 29% and 7.6 months, respectively. Patients with a high early T/N ratio had a significantly poorer PFS than those with a low T/N ratio (P = 0.0131). On univariate analysis, early T/N ratio alone had a significant impact on PFS, and on mutivariate analysis, early T/N ratio alone was a significant prognostic factor for PFS. 201Tl-SPECT after postoperative radiotherapy was predictive of PFS in patients with macroscopically residual GM.

Acyclic retinoid, a novel synthetic retinoid, induces growth inhibition, apoptosis, and changes in mRNA expression of cell cycle- and differentiation-related molecules in human colon carcinoma cells.

Acyclic retinoid (ACR), a novel synthetic retinoid, has been demonstrated by us to inhibit the in vitro growth of human hepatoma cells, and this effect was associated with modification of cell cycle control molecules, suggesting that this agent may be useful in the chemoprevention and therapy of various types of malignancies. However, whether or not ACR exerts anticancer activities on human colon carcinoma cells has not yet been elucidated. The purpose of this study was to examine the inhibitory effects of ACR in human colon carcinoma cells and to characterize the molecular mechanism of action of this agent. ACR inhibited the growth of the HCT116 and SW480 human colon carcinoma cell lines with IC50 values of about 30 and 60 microM, respectively. ACR also induced G1-phase cell cycle arrest and apoptosis in these cell lines. When the HCT116 cells were treated with 5-25 microM ACR, there was a marked decrease in the cellular levels of cyclin D1 mRNA and an approximate 2.5- to 3-fold increase in those of p21CIP1 mRNA, and this induction occurred via a p53-independent mechanism. Furthermore, ACR induced a dose-dependent mRNA elevation of differentiation markers at concentrations of ACR that affect the levels of expression of p21CIP1. These novel results suggest that ACR inhibits cell proliferation by inducing G1 arrest and apoptosis and that cyclin D1 and p21CIP1 play critical roles in the molecular mechanisms of growth inhibition and differentiation induced by ACR. Collectively, these findings provide further evidence that ACR may be a potential agent for the chemoprevention and therapy of human colon cancer.

Anthraquinone derivative emodin inhibits tumor-associated angiogenesis through inhibition of extracellular signal-regulated kinase 1/2 phosphorylation.

An anthraquinone derivative, emodin, suppresses tumor development both in vitro and in vivo. In this study, we examined the anti-angiogenic activity of emodin and its modifying effect on the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. In cell cultures, emodin inhibited endothelial cell proliferation, migration, and tube formation in a dose-dependent manner. In addition, the mouse dorsal air sac assay revealed the vivo anti-angiogenic potential of emodin. Matrix metalloproteinase-9 (MMP-9) expression, which is critical for the angiogenic process, including migration and tube formation, decreased after exposure to emodin, as determined by polymerase chain reaction with reverse transcription (RT-PCR) and gelatin zymography. Moreover, the phosphorylation of ERK 1/2 decreased after exposure to emodin in a dose-dependent manner. These observations suggest that emodin has the potential to inhibit several angiogenic processes and that these effects may be related to suppression of the phosphorylation of ERK 1/2.

Reduced expression level of mgmt mRNA and beta-catenin gene mutation in rat colon tumors.

BACKGROUND: O6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair protein and protects DNA from the biological effects of alkylating carcinogens. The purpose of this study was to investigate the association between the mRNA expression level of the Mgmt gene and mutation of the beta-catenin gene in rat colon tumors induced by azoxymethane (AOM) plus dextran sulfate sodium (DSS). MATERIALS AND METHODS: Eleven tumor samples from rat colon treated by AOM plus DSS were examined. Mutation of the beta-catenin gene was identified by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. The expression level of Mgmt mRNA was determined by reverse transcription-PCR (RT-PCR). RESULTS: Four out of five adeno-carcinoma samples bearing beta-catenin gene mutation (5 out of 11, 45%) displayed a decrease in expression levels of Mgmt mRNA (p<0.02). CONCLUSION: These results suggest that the reduced expression of Mgmt mRNA and beta-catenin gene mutation may contribute to the development of rat colon tumors.

Clinical significance of HIF-1alpha expression in patients with esophageal cancer treated with concurrent chemoradiotherapy.

AIM: We investigated whether hypoxia-inducible factor-1α (HIF-1 α) expression in pretreatment biopsies of esophageal cancer is predictive of clinical outcome in patients with esophageal cancer undergoing concurrent chemoradiotherapy (CRT). PATIENTS AND METHODS: A total of 25 patients were reviewed. Radiotherapy was administered to total doses of 40-66.6 Gy (median: 66.6 Gy) with a single fraction of 1.8-2 Gy. Cisplatin (80 mg/m2 on day 1) and 5-fluorouracil (800 mg/m2 on days 2-6) were administered concurrently with radiotherapy, every 3-4 weeks to a total of 1-2 courses. Tissue samples from esophageal cancer were obtained from all 25 patients by biopsy before concurrent CRT, and semiquantitative analyses of HIF-1α expression were performed using immunohistochemical staining. RESULTS: High HIF-1α expression was observed in 11 out of 25 patients (42.7%), and HIF-1α expression was significantly correlated with initial response to CRT (p=0.0027). Patients with high HIF-1α expression had significantly poorer local control (LC) (5-year LC: 42.7%) than those with low expression (5-year LC: 72.5%; p=0.0322). Patients with high HIF-1α expression also had significantly lower recurrence-free survival (RFS) (5-year RFS: 18.2%) compared to those with low HIF-1α expression (5-year RFS: 39.8%; p=0.0009), and on multivariate analysis, HIF-1α (p=0.001) and number of chemotherapy courses (p=0.010) were independent prognostic factors for RFS. CONCLUSION: HIF-1α expression is significantly correlated with initial response to concurrent CRT, and is predictive of RFS for patients with esophageal cancer receiving concurrent CRT.

Clinical significance of GLUT-1 expression in patients with esophageal cancer treated with concurrent chemoradiotherapy.

This study aimed to investigate whether glucose transporter-1 (GLUT-1) expression in a pretreatment esophageal cancer biopsy was predictive of clinical outcomes in patients with esophageal cancer undergoing concurrent chemoradiotherapy (CRT). A total of 25 patients with esophageal cancer treated with concurrent CRT were reviewed. Radiotherapy was administered up to total doses of 40-66.6 Gy (median 66.6 Gy) with a single fraction of 1.8-2 Gy. Regarding chemotherapy, cisplatin (80 mg/m(2) on day 1) and 5-fluorouracil (800 mg/m(2) on days 2-6) were used concurrently with radiotherapy, every 3-4 weeks for a total of 1-2 courses. Tissue samples from esophageal carcinoma were obtained from the 25 patients by biopsy prior to concurrent CRT, and a semiquantitative analysis of GLUT-1 expression was performed using immunohistochemical staining. High GLUT-1 expression was observed in 7 of 25 (28%) patients, and GLUT-1 expression was significantly correlated with clinical T stage (p=0.0454), clinical N stage (p=0.0324) and initial response to CRT (p=0.0185). Patients with a high GLUT-1 expression had significantly poorer local control (LC) (5-year LC 28.6%) than those with a low expression (5-year LC 73.4%, p<005). Multivariate analysis revealed that GLUT-1 and the number of chemotherapy courses were independent prognostic factors for LC. Patients with a high GLUT-1 expression had significantly lower recurrence-free survival (RFS) compared to those with a low GLUT-1 expression (p=0.0405). Multivariate analysis revealed that GLUT-1, the number of chemotherapy courses and clinical M stage were independent prognostic factors for RFS. GLUT-1 expression was significantly correlated with clinical T stage, clinical N stage and initial response to concurrent CRT, and was predictive of LC and RFS for patients with esophageal cancer treated with concurrent CRT.

Inhibitory effect of rice bran-derived crude glycosphingolipid on colon preneoplastic biomarker lesions induced by azoxymethane in male F344 rats.

The aim of the present study was to examine whether crude glycosphingolipid (cGSL) has short-term chemopreventive effects on the preneoplastic biomarker lesions involved in carcinogen-induced rat colon carcinogenesis. We also examined whether cGSL affects cell proliferation and apoptosis in these lesions. The crude preparation was obtained by the simple ethanol extraction method. Five-week-old male F344 rats were divided into 6 groups. Rats in groups 1-4 were given subcutaneous injections of azoxymethane (AOM) (20 mg/kg body weight) once a week for 2 weeks. Starting 1 week before the first injection of AOM, the rats in groups 2, 3 and 4 were fed a diet containing 250, 1,000 and 3,000 ppm cGSL, respectively, for 5 weeks. The experiment was terminated 5 weeks after the start date, and the number of aberrant crypt foci (ACF) and mucin-depleted foci (MDF) was counted. Dietary cGSL significantly inhibited the induction of ACF (group 3, P<0.01; group 4, P<0.05) and MDF (groups 2 and 3, P<0.001; group 4, P<0.05) as compared to group 1 treated with AOM alone. In groups 3 and 4, proliferating cell nuclear antigen-positive indices of epithelial cells were significantly lower than in group 1 (group 3, P<0.05; group 4, P<0.005). Caspase-3-positive indices were significantly higher in groups 3 and 4 than in group 1 (group 3, P<0.01; group 4, P<0.001). These results suggest that dietary cGSL had a potent chemopreventive effect in the present short-term colon carcinogenesis bioassays, and that this effect may be associated with the inhibition of ACF and MDF and the induction of apoptosis.