Sulfamethoxazole is Metabolized and Mineralized at Extremely Low Concentrations.

The presence of organic micropollutants in water and sediments motivates investigation of their biotransformation at environmentally low concentrations, usually in the range of µg L-1. Many are biotransformed by cometabolic mechanisms; however, there is scarce information concerning their direct metabolization in this concentration range. Threshold concentrations for microbial assimilation have been reported in both pure and mixed cultures from different origins. The literature suggests a range value for bacterial growth of 1-100 µg L-1 for isolated aerobic heterotrophs in the presence of a single substrate. We aimed to investigate, as a model case, the threshold level for sulfamethoxazole (SMX) metabolization in pure cultures of Microbacterium strain BR1. Previous research with this strain has covered the milligram L-1 range. In this study, acclimated cultures were exposed to concentrations from 0.1 to 25 µg L-1 of 14C-labeled SMX, and the 14C-CO2 produced was trapped and quantified over 24 h. Interestingly, SMX removal was rapid, with 98% removed within 2 h. In contrast, mineralization was slower, with a consistent percentage of 60.0 ± 0.7% found at all concentrations. Mineralization rates increased with rising concentrations. Therefore, this study shows that bacteria are capable of the direct metabolization of organic micropollutants at extremely low concentrations (sub µg L-1).

Hypertrophy of Lumbopelvic Muscles in Inactive Women: A 36-Week Pilates Study.

BACKGROUND: The use of Pilates in various fields of sport sciences and rehabilitation is increasing; however, little is known about the muscle adaptations induced by this training method. HYPOTHESIS: A standardized Pilates training program for beginners (9 months; 2 sessions of 55 minutes per week) will increase the muscle volume and reduce potential side-to-side asymmetries of the quadratus lumborum, iliopsoas, piriformis, and gluteus muscles (gluteus maximus, medius, and minimus). STUDY DESIGN: Controlled laboratory study. LEVEL OF EVIDENCE: Level 3. METHOD: A total of 12 inactive, healthy women (35.7 ± 5.4 years) without previous experience in Pilates were randomly selected to participate in a supervised Pilates program (36 weeks, twice weekly). Muscle volume (cm3) was determined using magnetic resonance imaging at the beginning and end of the intervention program. Side-to-side asymmetry was calculated as [(left - right volume) × 100/right volume]. RESULTS: Small, nonsignificant (P > 0.05) differences in the volume of the quadratus lumborum, iliopsoas, piriformis, and gluteus muscles were observed between pre- and post-Pilates program timepoints. Before and after Pilates, side-to-side asymmetry was less than 6% and nonsignificant in all muscles analyzed. CONCLUSION: Modern Pilates performed twice weekly for 9 months did not elicit substantial changes in the volume and degree of asymmetry of the selected lumbopelvic muscles in inactive women. CLINICAL RELEVANCE: The benefits of Pilates in rehabilitation or training are likely elicited by neuromuscular rather than morphological adaptations. Pilates has no significant impact on muscle volume and does not alter side-to-side ratios in muscle volume (degree of asymmetry) of the lumbopelvic muscles.

Micronuclei in bone marrow and liver in relation to hepatic metabolism and antioxidant response due to coexposure to chloroform, dichloromethane, and toluene in the rat model.

Genotoxicity in cells may occur in different ways, direct interaction, production of electrophilic metabolites, and secondary genotoxicity via oxidative stress. Chloroform, dichloromethane, and toluene are primarily metabolized in liver by CYP2E1, producing reactive electrophilic metabolites, and may also produce oxidative stress via the uncoupled CYP2E1 catalytic cycle. Additionally, GSTT1 also participates in dichloromethane activation. Despite the oxidative metabolism of these compounds and the production of oxidative adducts, their genotoxicity in the bone marrow micronucleus test is unclear. The objective of this work was to analyze whether the oxidative metabolism induced by the coexposure to these compounds would account for increased micronucleus frequency. We used an approach including the analysis of phase I, phase II, and antioxidant enzymes, oxidative stress biomarkers, and micronuclei in bone marrow (MNPCE) and hepatocytes (MNHEP). Rats were administered different doses of an artificial mixture of CLF/DCM/TOL, under two regimes. After one administration MNPCE frequency increased in correlation with induced GSTT1 activity and no oxidative stress occurred. Conversely, after three-day treatments oxidative stress was observed, without genotoxicity. The effects observed indicate that MNPCE by the coexposure to these VOCs could be increased via inducing the activity of metabolism enzymes.

Marked effects of Pilates on the abdominal muscles: a longitudinal magnetic resonance imaging study.

PURPOSE: The study's purpose was to analyze the effects of Pilates on the volume of the rectus abdominis (RA), obliques, and transversus abdominis, with the last two considered conjointly (OT). METHODS: The volume of OT and RA were determined using magnetic resonance imaging in nine nonactive healthy women, before and after 36 wk of a standardized Pilates training program (Modern Pilates). RESULTS: The volume of the dominant OT was increased by 8% (P < 0.05) with training, whereas the nondominant OT volume remained unchanged (+2%, P = 0.58). The total volume of RA increased by 21% after Pilates (P < 0.05) because of a similar increase of dominant and nondominant RA volume (21% and 20%, respectively, P < 0.05). Before Pilates, the volume of the OT was 8% greater in the nondominant compared with the dominant side (P < 0.01). This asymmetry was compensated by Pilates training (2%, P = 0.43). No side-to-side asymmetries in RA muscle volumes were observed either before (2%, P = 0.51) or after (1%, P = 0.81) Pilates. CONCLUSIONS: The present study reveals the existence of asymmetries in the muscles of the abdominal wall in nonactive healthy women. Pilates practice twice a week for 9 months elicits hypertrophy of the abdominal wall muscles, particularly of the RA, and eliminates preexisting asymmetries of the OT. Modern Pilates can be recommended as an effective method to reinforce the muscles of the abdominal wall and to compensate preexisting asymmetric developments.