15 research outputs found
Tensiomyographic Characteristics of Rectus Femoris after a Single Bout of Intense Exercise
It is not well known how local fatigue can impair the contractile
properties of skeletal muscle, so the aim of this study was to determine the Tensiomyographic (TMG)
characteristics of Rectus Femoris (RF) after a single bout of intense exercise. Approach: Twelve
healthy male volunteers (mean±SEM; age, 24.16±0.62 years, height 172.02±1.21 cm, body mass
71.84±2.19 kg, BMI 24.42±0.70 kg m-1) were recruited. Results: In session 1, a graded exercise test
on cycle ergometer was performed in order to determine subject’s maximal oxygen uptake (VO2max)
and power at this key point (pVO2max). In a second testing session, TMG rest values were assessed and
then all subjects carried out 2 min of cycling at pVO2max after which TMG analysis was applied again.
The results showed subject’s VO2max values of 53.44±2.67 ml kg-1 min-1, reaching a mean pVO2max of
270.83±8.61 W. Maximal radial displacement (Dm) and time from the onset of electrical stimulus to
10% of Dm (Td) were significantly lower at post-test (from 7.577.57±0.92-4.37±0.67 mm; p = 0.01,
for Dm and from 25.25±0.57-22.44±0.89 ms; p≤0.05, for Td). Conclusion/Recommendations: It can
be concluded that a brief and intense exercise consisting in 2 min of cycling at PVO2max provokes a
reduction in contractile properties of RF considering TMG parameters such as Dm and Td. More
studies are needed to clarify the role of muscle fatigue on temporal TMG parameters
Cardiovascular risk factors, caloric intake and practice of physical activity in college students. A preliminary study.
The aim of this investigation were to determine the level of physical activity practice and to define the presence of cardiovascular risk factors associated with body composition and caloric intake in college students. A total of 81 college students (38 and 41 females and males, respectively) were submitted to a complete evaluation that consisted of an analysis of food-intake behavior, measures of several body composition variables (height, weight, body mass index, fat and muscle mass, waist and hip circumferences, waist-hip ratio, and sum of 6 skinfolds), blood pressure assessment, and physical activity level calculation. The results show sex differences in blood pressure and body composition variables; although an optimal food-intake patterns, a high level of physical activity practice and the absence of cardiovascular risk factors seem to generate healthy profiles in this population. Key words:cardiovascular risk factors, food-intake patterns, physical activity, college students
Health related quality of life and depression in women with Fibromialgia syndrome: effects of a long-term exercise program
Benefits on health related quality of life and depression by using a long-term exercise program in women with fibromialgia syndrome
A Hyperactive Signalosome in Acute Myeloid Leukemia Drives Addiction to a Tumor-Specific Hsp90 Species
Acute myeloid leukemia (AML) is a heterogeneous and fatal disease with an urgent need for improved therapeutic regimens given that most patients die from relapsed disease. Irrespective of mutation status, the development of aggressive leukemias is enabled by increasing dependence on signaling networks. We demonstrate that a hyperactive signalosome drives addiction of AML cells to a tumor-specific Hsp90 species (teHsp90). Through genetic, environmental, and pharmacologic perturbations, we demonstrate a direct and quantitative link between hyperactivated signaling pathways and apoptotic sensitivity of AML to teHsp90 inhibition. Specifically, we find that hyperactive JAK-STAT and PI3K-AKT signaling networks are maintained by teHsp90 and, in fact, gradual activation of these networks drives tumors increasingly dependent on teHsp90. Thus, although clinically aggressive AML survives via signalosome activation, this addiction creates a vulnerability that can be exploited with Hsp90-directed therapy
Structure–Activity Relationship in a Purine-Scaffold Compound Series with Selectivity for the Endoplasmic Reticulum Hsp90 Paralog Grp94
Grp94 is involved in the regulation
of a restricted number of proteins
and represents a potential target in a host of diseases, including
cancer, septic shock, autoimmune diseases, chronic inflammatory conditions,
diabetes, coronary thrombosis, and stroke. We have recently identified
a novel allosteric pocket located in the Grp94 N-terminal binding
site that can be used to design ligands with a 2-log selectivity over
the other Hsp90 paralogs. Here we perform extensive SAR investigations
in this ligand series and rationalize the affinity and paralog selectivity
of choice derivatives by molecular modeling. We then use this to design <b>18c</b>, a derivative with good potency for Grp94 (IC<sub>50</sub> = 0.22 ÎĽM) and selectivity over other paralogs (>100- and
33-fold for Hsp90α/β and Trap-1, respectively). The paralog
selectivity and target-mediated activity of <b>18c</b> was confirmed
in cells through several functional readouts. Compound <b>18c</b> was also inert when tested against a large panel of kinases. We
show that <b>18c</b> has biological activity in several cellular
models of inflammation and cancer and also present here for the first
time the in vivo profile of a Grp94 inhibitor