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Roux-en-Y gastric bypass (RYGB) surgery has historically been the bariatric procedure of choice by many surgeons. However, sleeve gastrectomy (SG) and laparoscopic adjustable gastric banding (LAGB) procedures may be preferred for certain patient populations. This study analyzed recovery time and effectiveness of three bariatric surgery types to determine the surgical method associated with the most weight loss and the shortest amount of hospitalized recovery time. Two hundred consecutive bariatric surgery patients were divided into three cohorts: RYGB, LAGB, and SG. Patient records were analyzed for weight loss, complications, and length of stay postoperatively. Of 200 patients, 17 did not present to the office for recommended follow-up appointments; thus, there was insufficient follow-up documentation (n = 183). RYGB was the most common operation (51.0%) followed by SG. Bivariate analysis showed a positive correlation between increased BMI and surgeon choice of RYGB or SG (χ2 = 27.646; p = 0.002). In this study, RYGB was associated with longer hospitalization (χ2 = 168.786; p < 0.001). RYGB and SG resulted in more weight loss than LAGB (p < 0.001; p < 0.001, respectively). Thus, it can be concluded that SG would be the most effective method with the least amount of recovery time.
Protease-activated Receptor-1 (PAR-1) is a G protein-coupled receptor activated by the serine protease thrombin. Neurons and glial cells express PAR-1, and dysregulation of thrombin and/or PAR-1 is implicated in inflammatory disorders, neurodegenerative diseases, and spinal cord injury. We confirmed PAR-1 localization on rat Schwann cells using immunocytochemistry and confirmed gene expression with RT- qPCR (reverse transcription quantitative real-time PCR). We hypothesized that PAR-1 activation may involve a feedback mechanism, by which initial activation modulates PAR-1 mRNA levels, protein expression, and therefore future sensitivity of the cell to PAR-1 activation. Schwann cells were treated with 100 nM of the synthetic peptide SFLLRNP to activate PAR-1, and RT- qPCR was conducted for PAR-1 mRNA following incubations of 0, 4, 8, or 12 h. We demonstrate that PAR-1 mRNA levels are stable following PAR-1 activation in Schwann cells, indicating that other mechanisms may be responsible for the PAR-1 mRNA dysregulation observed in injury and disease. Our results also suggest that, in Schwann cells, there is no de novo synthesis of PAR-1 to replace internalized receptors in the period soon after (∼30 min after) extended periods of activation. Understanding the mechanisms underlying PAR-1 expression is essential since disruption of PAR-1 signaling in the nervous system can contribute to disease states.
Alliaria petiolata (garlic mustard) is a biennial plant that is invasive in woodland areas in the Midwestern and Northeastern United States. Garlic mustard has been shown in previous studies to inhibit fungal and microbial growth. It therefore seems plausible that garlic mustard may alter the metabolic function of the soil microbial community and may impact these communities early during its biennial life-cycle. To address whether either of these possibilities occur, garlic mustard and a common native woodland plant, Ageratina altissima (white snakeroot), were grown from seed in soil collected from Iowa woodland plots free of garlic mustard in a controlled environment. After three months of growth, the soil was analyzed with Biolog EcoPlates to determine if garlic mustard seedlings impacted the metabolic profile of the soil microbial community differently than white snakeroot. An ANOSIM determined that garlic mustard and white snakeroot treatments had different effects on metabolic profiles of the soil microbial communities (p = 0.001, R = 0.301), and that garlic mustard depressed the metabolic potential of the soil microbial community. Additionally, the extent to which garlic mustard inhibits native plant growth while also stimulating the growth of subsequent generations of garlic mustard was studied. The growth of white snakeroot and garlic mustard were compared when grown in soil collected from woodland garlic mustard infestations to plants grown in woodland soil lacking garlic mustard. Wilcoxon Signed-Rank tests indicate that white snakeroot growth was positively impacted by soil history, while garlic mustard was not (p = 0.05; p = 0.60, respectively). We conclude that garlic mustard has the potential to alter the function and possibly the composition of the soil microbial communities, while surprisingly increasing the growth of white snakeroot seedlings. Furthermore, it seems that garlic mustard can elicit effects during its first three months of growth, suggesting that this plant should be targeted for removal early during its biennial life-cycle. Future studies should examine these findings in the field.
The symbiotic relationship between an animal and its gut microbiota is known to influence host neural function and behavior. The mechanisms by which gut microbiota influence brain function are not well understood. This study measures the impact of gut microbiota on olfactory behavior of Drosophila larvae and explores possible mechanisms by which gut microbiota communicate with neural circuits. The microbiota load in Drosophila larvae was altered by treating them with antibiotics or probiotics. Control larvae and larvae with altered microbiota loads were subjected to olfactory assays to analyze the chemotaxis response of larvae to odorants. Larvae treated with antibiotics had reduced microbiota load and exhibited reduced chemotaxis response toward odorants compared to control animals. This behavioral phenotype was partially rescued in larvae treated with probiotics that resulted in partial recovery of microbiota loads. Expression levels of several olfactory genes in larvae subjected to different treatments were analyzed. The results suggest that the expression of certain components of the GABA signaling pathway is sensitive to microbiota load. The study concludes that the microbiota influences homeostatic mechanisms in the host that control GABA production and GABA-receptor expression, which are known to impact host olfactory behavior. These results have implications for understanding the bidirectional communication between a host organism and its microbiota as well as for understanding the modulation of olfactory neuron function.
Armadillidium vulgare is a terrestrial isopod that defends itself by conglobation, or rolling into a ball. Conglobation was elicited by placing woodlice on a platform heated to 40°C, the lowest temperature that elicited a response yet did not harm the woodlice. Woodlice were examined to determine whether habituation to heat occurred. This was accomplished by testing whether conglobation would decrease after exposure to heat over a series of trials. Each control woodlouse was exposed (n = 50) to a heat stimulus. Two trials per woodlouse were conducted, with a 38 min interval between trials. Each experimental woodlouse (n = 50) was exposed to the heat stimulus over a series of 20 consecutive trials with a two min interval between each trial. The variable was presence or absence of repeated trials. Control woodlice showed no significant difference in the frequency of conglobation between the first and the last trial. However, conglobation significantly declined in successive trials of experimental woodlice, indicating that habituation occurred. Dishabituation was examined by presenting the heat stimulus in intervals ranging from four to twelve min, extending each successive interval by two min. Control woodlice continued to respond every time they were exposed to heat. When the interval was lengthened to twelve min, 96% of the experimental woodlice recovered the conglobation response. Experimental woodlice still conglobated significantly (p < 0.001) less than control woodlice after a 4 min interval, but there were no significant differences in any subsequent trials (p > 0.348). The ability to habituate to innocuous stimuli is adaptive in nature where stimulus filtering allows animals to respond to biologically relevant stimuli. The data show that woodlice are able to habituate to a stimulus and then dishabituate, thus demonstrating non associative learning in crustaceans.
Water pollution caused by increasing pharmaceutical and pesticide use has the potential to negatively affect aquatic ecosystems through the effects of individual chemicals and potentially synergistic mixtures. However, mixtures' synergistic effects are less well understood than the individual effects of their constituents. One mechanism for synergism is enzyme inhibition. The antidepressant fluoxetine inhibits cytochrome P450 enzymes (CYPs) in several taxa, including humans, fish, and polychaetes. CYPs are also used by macroinvertebrates to detoxify neonicotinoid insecticides, which can have detrimental impacts on aquatic macroinvertebrate communities. We hypothesized that fluoxetine inhibits invertebrates' ability to detoxify neonicotinoids, resulting in synergistic toxicity to aquatic macroinvertebrates. Acute (24-hour) immobilization assays with the water flea Daphnia magna were used to assess the toxicity of fluoxetine, the neonicotinoid imidacloprid, and a mixture of the two. Individual dose-response curves revealed an EC50 of 5.43 mg/L for fluoxetine and 10 mg/L for imidacloprid. A fluoxetine/imidacloprid mixture immobilized significantly fewer D. magna than did the individual chemicals, suggesting that these chemicals may interact antagonistically in D. magna. However, mixtures of imidacloprid and prochloraz, a known inhibitor of D. magna CYPs, also exhibited a near-significant antagonistic interaction. These antagonisms could stem from imidacloprid's inhibition of feeding in D. magna or fluoxetine's inhibition of imidacloprid's target receptor. Even if fluoxetine and imidacloprid are not synergistically toxic, they could still individually impact macroinvertebrates. Moreover, diversity in the invertebrate community suggests that research in additional species is warranted.
Antibiotic resistance in the environment occurs naturally in bacteria, and is a growing problem due to the use of antibiotics both in human and animal medicine. β-lactamases are the most studied group of antibiotic resistant genes, as these enzymes hydrolyze penicillin, ampicillin, and other β-lactam antibiotics. The purpose of this study was to determine if there was a statistically significant difference between numbers of copies of β-lactamase genes (bla1, bla-TEM, bla-SHV) from ampicillin-resistant bacteria in soil samples from a horse pasture and a crop field. Colony counts suggested there was a significant difference (p < 0.05) in ampicillin-resistant bacteria between the two soil samples. Upon completion of PCR and gel electrophoresis, there was no statistically significant difference in the presence of bla1 and bla-TEM (p > 0.05) in bacteria from each soil sample, but there was a significant difference in the presence of bla-SHV (p = 0.0061). A significant difference in ampicillin-resistant colonies and bacteria with bla-SHV suggests that ampicillin used in the horses may be selecting for ampicillin resistance in the soil bacteria. There may also be high concentrations of other ampicillin-resistant genes present in agricultural rich soils, particularly in animal pastures. Future studies need to be undertaken to document the level of antibiotic resistance found in animal pastures to understand the impact this may have on animal and human health.
Respiratory muscle resistance training (RMRT) is the practice of breathing through a respiratory mouth-device designed to restrict airflow to the user, increase airway resistance and subsequently increase the work necessary for the respiratory muscles to inspire and expire. During periods of exercise, there is an elevation in blood lactate levels as well as H+, which is a major contributing factor to exercise fatigue. The resultant elevated plasma acidity is compensated by an increased ventilation rate, which leads to increased expiration and removal of carbon dioxide (CO2) from the body. It was hypothesized that healthy college students that undergo four weeks of RMRT exercise will have improved oxygen consumption at the point of lactate threshold (VO2LT) during a graded exercise running test. The experimental group used an Expand-a-Lung RMRT device 5 times a week and tested weekly for four weeks by using near-infrared spectroscopy (NIRS) with a BSX Insight blood oxygenation sensor to measure the amount of oxygen-saturated hemoglobin (%SmO2) in the calf muscle. Our preliminary results show some improvement in ventilation in the experimental group, with tidal volume significantly increasing the most. The VO2 at lactate threshold did show an increase, providing support for our original hypothesis.
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