The present study aimed to analyze age-related changes to motor coordination, balance, spinal cord oxidative biomarkers in 3-, 6-, 18-, 24-, and 30-month-old rats. The effects of low-intensity exercise on these parameters were also analyzed in 6-, 18-, and 24-month-old rats. Body weight, blood glucose, total cholesterol, and high-density lipoprotein (HDL) cholesterol were assessed for all rats. The soleus muscle weight/body weight ratio was used to estimate skeletal muscle mass loss. Body weight increased until 24 months; only 30-month-old rats exhibited decreased blood glucose and increased total cholesterol and HDL cholesterol. The soleus muscle weight/body weight ratio increased until 18 months, followed by a small decrease in old rats. Exercise did not change any of these parameters. Stride length and step length increased from adult to middle age, but decreased at old age. Stride width increased while the sciatic functional index decreased in old rats. Performance in the balance beam test declined with age. While gait did not change, balance improved after exercise. Aging increased superoxide anion generation, hydrogen peroxide levels, total antioxidant capacity, and superoxide dismutase activity while total thiol decreased and lipid hydroperoxides did not change. Exercise did not significantly change this scenario. Thus, aging increased oxidative stress in the spinal cord, which may be associated with age-induced changes in gait and balance. Regular low-intensity exercise is a good alternative for improving age-induced changes in balance, while beneficial effects on gait and spinal cord oxidative biomarkers cannot be ruled out because of the small number of rats investigated (n=5 or 6/group).
Objective
Oxidative stress plays an important role in neuropathic pain. Spinal manipulative therapy (SMT) can exert beneficial effects in pain outcomes in humans and animal models. SMT can also modulate oxidative stress markers in both humans and animals. We aimed to determine the effect of Impulse®-assisted SMT (ISMT) on nociception and oxidative stress biomarkers in the spinal cord and sciatic nerve of rats with neuropathic pain (NP).
Methods
NP was induced by chronic constriction injury (CCI) of the sciatic nerve. Animals were randomly assigned to naive, sham (rats with sciatic nerve exposure but without ligatures) and CCI, with and without ISMT. ISMT was applied onto the skin area corresponding to the spinous process of L4-L5, 3 times/week, for 2 weeks. Mechanical threshold, latency to paw withdrawal to thermal stimulus and oxidative stress biomarkers in spinal cord and sciatic nerve were the main outcomes evaluated.
Results
ISMT significantly increased mechanical threshold and withdrawal latency after CCI. In the spinal cord, ISMT prevented the increase of pro-oxidative superoxide anion generation and hydrogen peroxide levels. Lipid hydroperoxide levels both in the spinal cord and in the sciatic nerve were attenuated by ISMT. Total antioxidant capacity increased in the spinal cord and sciatic nerve of CCI rats with and without ISMT. CCI and ISMT did not significantly change the total thiol content of the spinal cord.
Conclusions
Our findings suggest reduced oxidative stress in the spinal cord and/or nerve may be an important mechanism underlying a therapeutic effect of SMT to manage NP non-pharmacologically.
Antimicrobial resistance (AMR) is currently discussed as an important issue worldwide, and the presence of antimicrobial residues (ARs) and antimicrobial resistance genes (ARGs) in the environment, especially in the water sources, is a challenge for public health. This study was conducted to evaluate the occurrence and diversity of AR and ARG in water sources from an urban center, in Southern Brazil. A total of thirty-two water samples from drinking water treatment plants ( 24) and sewage systems (8) were collected during two annual samplings, winter and summer. The PCR was performed by 18 ARGs, and the detection of 47 ARs was performed by LC-MS/MS. All sewage samples presented carbapenemases, ESBL, and mcr-1 genes as well as quinolones and sulfamethoxazole residues. In drinking water, we just detected bla TEM and tetB genes and doxycycline residues in samples before treatment. This study provides data about AR and ARG in drinking water and sewage systems showing that these sources are important reservoirs of both. The limited effectiveness of wastewater treatment processes to remove mainly AR demonstrates the need to implement better protocols of disinfection, in order to limit the spread of AMR in the environment.
KeywordsContaminant emerging concern (CEC) • Drinking water treatment plant (DWTP) • Wastewater treatment plant (WWTP) • Antimicrobial resistance genes (ARG) • Antimicrobial residues (AR)
The Contaminants of Emerging Concern (CECs), including pesticides, have been a trending topic and Brazil is the country with the highest usage of pesticides worldwide. This study aimed to measure the presence of pesticide residues in the water from different sources in the city of Porto Alegre. We analyzed 55 samples from drinking water treatment plants, public water sites, and sewage treatment plants from winter 2018 to summer 2020 by solid‐phase extraction and high‐performance liquid chromatography–electrospray ionization mass spectrometry. Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility) and 15 of them were detected in different water samples, including seven insecticides, five antifungals, and three herbicides, with a wide range of toxicity levels and noticeable seasonal differences. For the worst‐case scenario evaluation, 20 out of 22 (90.9%) samples exceeded the Risk Quotient of 1. The sum of pesticide concentrations exceeded 100 ng L−1 in 66.7% of samples in February 19 and in 75% of samples in February 20 and the total pesticide concentration has reached the worrisome mark of 1615 and 954.96 ng L−1 respectively. Therefore, our results make evident the need to promote public policies to achieve better water quality monitoring.
Practitioner Points
Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility).
A total of 55 different water samples were analyzed, and 15 pesticides were detected and five quantified.
For the worst‐case scenario evaluation, 20 out of 21 samples exceeded the Risk Quotient of 1 on Feb/20.
The pesticide concentrations sum exceeded 100 ng L−1 in 66.7% of samples on February 19 and in 75% of samples on February 20.
It is mandatory to improve water monitoring to guide the development of public policies concerning its quality.
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