The effects of flexibility training on exercise-induced muscle damage in young men with limited hamstrings flexibility.

Adaptations to 6 weeks of supervised hamstring stretching training and its potential impact on symptoms of eccentric exercise-induced muscle damage (EIMD) were studied in 10 young, untrained men with limited hamstrings flexibility. Participants performed unilateral flexibility training (experimental leg; EL) on an isokinetic dynamometer, while the contralateral limb acted as control (CL). Hip range of motion (ROM), passive, isometric, and concentric torques, active optimum angle, and biceps femoris and semitendinosus muscle thickness and ultrasound echo intensity were assessed both before and after the training. Additionally, muscle soreness was assessed before and after an acute eccentric exercise bout in both legs (EL and CL) at post-training only. Hip ROM increased (P < .001) only in EL after the training (EL = 10.6° vs CL = 1.6°), but no changes (P > .05) in other criterion measurements were observed. After a bout of eccentric exercise at the end of the program, isometric and dynamic peak torques and muscle soreness ratings were significantly altered at all time points equally in EL and CL. Also, active optimum angle was reduced immediately, 48 and 72 hours post-exercise, and hip ROM was reduced at 48 and 72 hours equally in EL and CL. Finally, biceps femoris muscle thickness was significantly increased at all time points, and semitendinosus thickness and echo intensity significantly increased at 72 hours, with no significant differences between legs. The stretching training protocol significantly increased hip ROM; however, it did not induce a protective effect on EIMD in men with tight hamstrings.

Proliferative indices and oncoprotein expression in benign and malignant breast biopsies.

BACKGROUND: Prognostic factors are used routinely in the management of breast cancer. However, their potential for identifying precursor malignant lesions has not been assessed. METHODS: We have examined 285 breast biopsy specimens (140 benign, 145 malignant) for DNA ploidy, S-phase fraction, Ki-67 nuclear antigen proliferative indices, and HER-2/neu and epidermal growth factor receptor oncoproteins. RESULTS: When proliferative indices were compared between the benign and malignant groups, differences were noted for DNA ploidy, S-phase fraction, and cell cycling index (p < 0.0005). When the benign nonproliferative specimens were compared with the atypical/proliferative benign specimens, proliferative indices failed to show any differences. When the specific subset of proliferative/atypical benign breast tissue was compared with the malignant specimens, DNA index, S-phase fraction, and cell cycling index showed significant differences. The mean for epidermal growth factor receptor was greater in the non-proliferative group but not statistically significant (p < 0.1). HER-2/neu oncoprotein failed to show any differences between the benign and malignant groups. Within the atypical benign group, Ki-67 correlated strongly with S-phase fraction and HER-2/neu (p < 0.01). CONCLUSIONS: We have demonstrated that proliferative indices can differentiate between benign and malignant breast tissues but not among specific subgroups. In addition, epidermal growth factor may differentiate between nonproliferative and proliferative/atypical benign biopsy results. Oncoprotein determination, ploidy, and DNA proliferative indices may be useful in defining malignant and benign breast disease but are not useful in distinguishing between benign and malignant breast disease with an increased likelihood for malignant transformation.