Analysis of cell cycle phases and proliferative capacity in mice bearing melanoma maintained on different dietary proteins

Background Diet seems to represent, directly or indirectly, 35% of all cancer reports. In this study, the influence of dietary protein on the growth of melanoma B16F10 was evaluated through analyses of cell cycle phases and proliferative capacity. Methods Flow cytometry and argyrophilic nucleolar organizer regions (AgNORs) technique were applied in mice bearing B16F10 melanoma cells fed on different dietary proteins. All data were submitted to statistical analyses. Results The G0/G1 phase increased for the animal groups fed bovine collagen hydrolysate (BCH) or BCH-P1 + whey protein isolate (WPI), compared with mice receiving only WPI, for all dietary groups treated and nontreated with paclitaxel. Mice that received BCH + WPI treated with paclitaxel showed the highest percentage of apoptosis compared with WPI group. AgNORs, total nucleolar organizer regions (NORs)/cells and dot number/cell for all dietary protein groups nontreated with paclitaxel were higher than for the WPI. The only two dietary protein groups treated with paclitaxel that presented higher total NORs and dot number/cell than the WPI group were BCH + WPI and BCH-P1 + WPI. Conclusions A significantly lower proliferative capacity and larger number of cells in the G0/G1 phase were observed for the dietary protein groups combining the two collagen hydrolysates, BCH or BCH-P1 with WPI, treated with paclitaxel. Castro GA, Maria DA, Rodrigues CJ, Sgarbieri VC. Analysis of cell cycle phases and proliferative capacity in mice bearing melanoma maintained on different dietary proteins.

Effect of low-dose combined oral contraceptive on aerobic capacity and anaerobic threshold level in active and sedentary young women

Background: The purpose of this study was to evaluate the effect of long-term use of oral contraceptives (DC) containing 0.20 mg of ethinylestradiol (EE) combined with 0.15 mg of gestodene (GEST) on the peak aerobic capacity and at the anaerobic threshold (AT) level in active and sedentary young women. Study Design: Eighty-eight women (23 +/- 2.1 years old) were divided into four groups active-OC (G1), active-NOC (G2), sedentary-OC (G3) and sedentary-NOC (G4) and were submitted to a continuous ergospirometric incremental test on a cycloergometer with 20 to 25 W min(-1) increments. Data were analyzed by two-way ANOVA with Tukey post hoc test. Level of significance was set at 5%. Results: The OC use effect for the variables relative and absolute oxygen uptake VO(2) mL kg(-1) min(-1); VO(2), L min(-1), respectively), carbon dioxide output (VCO(2), L min(-1)), ventilation (VE, L min(-1)), heart rate (HR, bpm), respiratory exchange ratio (RER) and power output (W) data, as well as the interaction between OC use and exercise effect on the peak of test and at the AT level did not differ significantly between the active groups (G1 and G2) and the sedentary groups (G3 and G4). As to the exercise effect, for all variables studied, it was noted that the active groups presented higher values for the variables VO(2), VCO(2), VE and power output (p<.05) than the sedentary groups. The RER and HR were similar (p>.05) at the peak and at the AT level between G1 vs. G3 and G2 vs. G4. Conclusions: Long-term use of OC containing EE 0.20 mg plus GEST 0.15 mg does not affect aerobic capacity at the peak and at the AT level of exercise tests. (C) 2010 Elsevier Inc. All rights reserved.

Thermostable variants of the recombinant xylanase A from Bacillus subtilis produced by directed evolution show reduced heat capacity changes

Directed evolution techniques have been used to improve the thermal stability of the xylanase A from Bacillus subtilis (XylA). Two generations of random mutant libraries generated by error prone PCR coupled with a single generation of DNA shuffling produced a series of mutant proteins with increasing thermostability. The most Thermostable XylA variant from the third generation contained four mutations Q7H, G13R, S22P, and S179C that showed an increase in melting temperature of 20 degrees C. The thermodynamic properties Of a representative subset of nine XylA variants showing a range of thermostabilities were measured by thermal denaturation as monitored by the change in the far ultraviolet circular dichroism signal. Analysis of the data from these thermostable variants demonstrated a correlation between the decrease in the heat capacity change (Delta C(p)) with an increase in the midpoint of the transition temperature (T(m)) on transition from the native to the unfolded state. This result could not be interpreted within the context of the changes in accessible surface area of the protein on transition from the native to unfolded states. Since all the mutations are located at the surface of the protein, these results suggest that an explanation of the decrease in Delta C(p) on should include effects arising from the prot inlsolvent interface.

Relationship among eccentric hip and knee torques, symptom severity and functional capacity in females with patellofemoral pain syndrome

Objective: To determine the relationships between eccentric hip and knee torques, symptom severity and functional capacity in females with patellofemoral pain syndrome (PFPS). Design: Within-subject correlational study. Setting: University biomechanics laboratory. Participants: 10 females diagnosed with PFPS. Main outcome measures: Eccentric strength of the hip abductors and lateral rotators, and knee extensors were assessed using an isokinetic dynamometer. A 10-cm visual analog scale was used to determine usual knee pain in the last week. The Anterior Knee Pain Scale (AKPS) was used to determine the functional capacity of the patients. Results: The study found that the greater the eccentric knee extensor and hip lateral rotator torques, the higher the functional capacity of the patients (p = 0.02, r = 0.72; p = 0.02, r = 0.72). It was also shown that the greater hip lateral rotator torque, the less the usual pain reported in the last week (p = 0.004, r = -0.84). Despite the lack of statistical significance (p = 0.11), it was also found a modest negative relationship between the eccentric knee extensor torque and the usual pain reported in the last week (r = -0.56) that was considered clinically meaningful (d = 1.4). Conclusions: This study showed that eccentric knee extensor and hip lateral rotator torques were associated with functional capacity and pain level in females with PFPS. Further investigations should be carried out to verify the effects of an intervention program focused on the eccentric action of these muscles with respect to the symptoms in patients with PFPS. (C) 2011 Elsevier Ltd. All rights reserved.

Characterisation of Leucaena condensed tannins by size and protein precipitation capacity

The ability of differently sized condensed tannins from the genus Leucaena, a fodder tree-legume, to bind protein at different pH values was evaluated to characterise their potential biological effects. Two factors affecting the ability of condensed tannin to bind protein, its major biological activity, have been purported to be the condensed tannin size and the pH of the reaction environment. To test these hypotheses, the protein-precipitating capacities of condensed tannin extracted from four Leucaena genotypes, L leucocephala (UHK636), L pallida (CQ3439), L trichandra (CP146568) and L collinsii (OFI52/88), were assessed. Condensed tannin from L leucocephala had approximately 50% of the ability to precipitate protein on a gg(-1) basis than L pallida or L trichandra, while L collinsii gave no measurable ability to precipitate protein (reaction environment pH 5.0). Increasing or decreasing the pH of the reaction solution away from pH 5.0 (approximately the isoelectric point of the protein) reduced the ability of condensed tannin from all the species to precipitate protein, the decrease being higher at pH 2.5 than at pH 7.5. Condensed tannins from each Leucaena species were also separated by size exclusion chromatography, and the fractions examined for protein-precipitating capacity. In general, it was found that the larger-sized condensed tannin of the accessions L pallida and L trichandra could precipitate more protein than the smaller-sized condensed tannin. This pattern was not found for L leucocephala. (C) 2001 Society of Chemical Industry.

Relationships between crude protein and mineral concentrations in alfalfa and value of alfalfa silage as a mineral source for periparturient cows

One hundred and eight samples from three cultivars of alfalfa were obtained from three cuttings in 1996-1998 to evaluate the relationship between crude protein (CP) and mineral concentrations of alfalfa with cutting and maturation. The CP content drastically decreased from 27.9 to 11.4% on DM with maturity. Highly positive correlations were observed between CP and K in the first and the second cutting of alfalfa. The Ca content remained almost constant throughout the growth period. Four multiparous Holstein cows were assigned an alfalfa silage diet or an orchardgrass silage diet from 3 weeks prepartum to 1 week postpartum to examine the effect on the mineral balance. In the prepartum and postpartum diet, the roughage to concentrate ratio was 70:30 and 50:50, with alfalfa being 50 and 100% of the roughage, respectively. The alfalfa contained 1.93% of K. No metabolic disorders occurred, but the body weight decreased drastically from 1 to 6 days postpartum with each diet because of the high milk production immediately after the parturition. Positive retention of N, Ca, P, Mg, and K was observed prepartum, whereas the cows had negative N and mineral retention from 2 to 4 days postpartum. The Ca and P absorption, and Mg retention of cows with the alfalfa diet were higher than with the grass diet. The plasma Ca and inorganic P were not affected by diet, but the plasma PTH at parturition and plasma hydroxyproline from 1 week prepartum to 1 week postpartum were higher with the alfalfa diet. These results suggest that the low K alfalfa is suitable not only to prevent the incidence of milk fever but also to increase Ca, P and Mg utilization of periparturient cows, but the mineral supplementation is needed for the postpartum cows immediately after the parturition. (C) 2001 Elsevier Science B.V. All rights reserved.