Changes In Plasma Cortisol Research Articles

Recombinant Bacillus subtilis expressing functional peptide and its effect on blunt snout bream (Megalobrama amblycephala) in two state of stress

This study was conducted to investigate the effects of recombinant Bacillus subtilis CM66-P4' (secreting P4, which related to previous research in this laboratory) on the antioxidant capacity and immune function of blunt snout bream (Megalobrama amblycephala) through in vitro and in vivo experiment. The culture experiment was divided into 3 groups, including control group (CG, with no additional bacteria), original bacteria group (OBG, with 2×109 CFU/kg Bacillus subtilis CM66) and recombinant bacteria group (RBG, with 2×109 CFU/kg Bacillus subtilis CM66-P4'). After 8 weeks of feeding, a part of the fish were subjected to fishing stress, and the rest were subjected to starvation stress test. Blood samples were collected for the determination of immune and stress-related indexes. The hepatocytes were divided into control group (CG) and experiment group with P4 peptide (LTG and HTG). The cells were collected after starvation treatment and the expression of related genes was detected. The results showed as follows: compared with the CG group, the gene expressions of hepatocytic hsp60 and hsp70 in the LTG and HTG groups were significantly suppressed after 24 h starvation stress (P < 0.05). The content of MDA, the activities of AKP and ALT in OBG group were significantly changed after 30 days starvation (P < 0.05), while the indexes in RBG group had no significant change. The changes of plasma cortisol, malondialdehyde (MDA) and Immunoglobulin M (IgM) in CG and OBG groups were significantly changed at 4 h after fishing stress (P < 0.05), while the indexes in RBG group was not. In conclusion, this study confirmed that Bacillus subtilis CM66-P4' has great potential in preventing adverse effects of stress on aquatic livestock.

Abstract 57: Macrolides for KCNJ5–mutated Aldosterone-Producing Adenoma (MAPA): a Study for Personalized Management of Primary Aldosteronism

Background: Somatic mutations in the KCNJ5 potassium channel involve up to 70% of the patients presenting with primary aldosteronism (PA) caused by an aldosterone-producing adenoma (APA). Macrolides corrected the altered function of the two common mutations G151R and L168R, in vitro suggesting their potential usefulness for personalized management of patients with KCNJ5-mutated APA. Hence, we investigated if the macrolide roxithromycin that restored the KCNJ5 channel function could lower plasma aldosterone and blood pressure (BP) in KCNJ5-mutated APA patients. Methods and Design: In a within-patient study we assessed changes of plasma aldosterone, active renin, cortisol and BP induced by an oral roxithromycin (150-300 mg) challenge, in consenting consecutive hypertensive patients. In parallel, we investigated the vascular and BP effects of macrolides ex vivo and in vivo in mice. Results: We recruited 425 consecutive patients: 19 had G151R - or L168R - mutated APA, 27 KCNJ5 wild-type APA, and the rest had no identifiable cause of hypertension. Roxithromycin lowered the plasma aldosterone concentration (p&lt;0.001), not BP, in the G151R- and L168R-mutated APA patients, but not in the wild-type. However, an aldosterone-independent BP decrease was seen in the much larger cohort of hypertensive patients without PA. In mice experiments, studies showed that this was accounted far by a significant anti-hypertensive effect of macrolides that involved an endothelium-NO-dependent vasodilatory action. Conclusions: The roxithromycin-induced fall of plasma aldosterone concentration might be a marker of the presence of KCNJ5-mutated APA. Moreover, our studies unveiled an anti-hypertensive effect of macrolides that involves endothelium- and NO-dependent vasodilation.

Does local anaesthetic reduce pain in rubber ring castration of neonatal lambs?

PICO Question In lambs less than 7 days old undergoing castration with rubber rings does administration of local anaesthetic compared to no local anaesthetic result in a reduction of pain-related behaviours? Clinical bottom line Category of research Treatment. Number and type of study designs reviewed Six studies were appraised; all were controlled clinical or field trials. Strength of evidence Moderate. Outcomes reported Local anaesthetic administered to lambs castrated with rubber rings resulted in the demonstration of fewer pain related behaviours and also diminished the increases in plasma cortisol in the immediate post-castration period when compared to lambs castrated without local anaesthetic. Local anaesthetic administered at least 15 minutes before rubber ring castration may significantly reduce behavioural signs of pain and plasma cortisol changes. Conclusion In lambs less than 7 days old undergoing castration with rubber rings, local anaesthetic reduces markers of pain when compared to lambs castrated without local anaesthetic. How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.

Welfare effects of environmental hypercapnia quantified by indicators based on morphology and allostatic load in Atlantic salmon (Salmo salar)

Water supply is a limited resource in most salmon hatcheries, which is compensated by reduced water flow and oxygenation. However, reduced water exchange can lead to accumulation of CO2, resulting in environmental hypercapnia, which may have negative impacts on fish welfare. Thus, environmental hypercapnia can be a common welfare problem for salmon in hatcheries, and particularly in recirculating systems (RAS).In this experiment, Atlantic salmon were exposed to chronic environmental hypercapnia during the last 68 days of the freshwater phase, whereupon effects on physiological stress coping mechanisms and morphological welfare indicators were investigated. Effects on stress coping mechanisms were quantified by measuring changes in brain serotonergic chemistry and plasma cortisol at basal levels and in response to a standardized acute stress test. The results show that exposure to elevated CO2 saturation in the water compromised stress responsiveness of brainstem serotonergic activity, altered osmotic homeostasis, and suppressed growth indicating that fish experience allostatic overload. However, no effects on morphological welfare indicators were observed. This accentuates the need for physiological measures, including physiological responses to controlled challenges to activate the stress axis, when investigating the welfare status of fish reared in systems with potential high CO2.

Change in plasma cortisol and glucose levels of Oncorhynchus keta according to water temperature

Chum salmon (Oncorhynchus keta) is a species of anadromous salmonid inhabiting coastal rivers in the North Pacific and the Arctic in the Bering and is the most widely distributed among Pacific salmon species. It is an important fish species in Korea as the salmon releasing project is being actively carried out. This study was conducted to investigate changes in the physiological activity of O. keta according to water temperature. Three experiments were conducted according to the water temperature and period, and the plasma concentrations of cortisol and glucose were analyzed from the blood samples of the experimental groups. Experiment I is a short-term water temperature experiment, in which water temperature stimulation was given for 4 hours at water temperatures of 12°C, 16°C (control), 20°C, and 24°C, and a recovery period was given for 4 hours. Experiment II is an experiment in which water temperature stimulation was given for 24 hours, 48 hours, and 72 hours at a high temperature of 24°C, and a recovery period was given for 12 hours, respectively. Experiment III is a long-term water temperature experiment, in which the water temperature was 12°C, 16°C (control), 20°C, and 24°C for 8 weeks. As a result of the experiment, in Experiment I, there was no significant difference in the survival rate between the experimental groups, but the concentration of cortisol and glucose in the plasma according to the set water temperature showed a significant difference. In Experiment II, there was no significant trend according to the maintenance time of the high-temperature state, but as the temperature increased, the plasma cortisol and glucose levels significantly increased compared to the control group. In Experiment III, all of the experimental group C (24°C) died in the 1st week, and there was no significant difference in the plasma glucose at the 1st and 8th weeks among the remaining experimental groups.

Comparative assessment of plasma cortisol and fecal corticoid metabolites (FCM) of Atlantic salmon (Salmo salar L.) subjected to acute- and long-term stress

Farmed Atlantic salmon (Salmo salar L.) are subject to a variety of stressors throughout production. Elevations of cortisol level in the blood are one of the major endocrine primary stress responses in vertebrates and are widely used as stress indicator. However, blood sampling is invasive and stressful procedures. Cortisol instantly released into the blood at sampling can easily interfere with the initial stress response of interest. Fecal corticoid metabolites (FCM) have been suggested for a less invasive assessment of stress in fish. In the present study, we evaluated stress responses by using plasma cortisol and FCM as stress indicators in Atlantic salmon. Atlantic salmon (with average weight 42 g) were exposed to 3 different stressors: 1) parr-smolt transformation; 2) infestation with salmon lice (Lepeophtheirus salmonis) for two-weeks; 3) infection with infectious salmon anaemia virus (ISAV) for four weeks. The results demonstrated that FCM levels correlated well with the plasma cortisol levels at single-point sampling during long-term stress (p < 0.05). Significant increases of both plasma cortisol and FCM were found two weeks after initiated 24 h light. Each tank was sampled twice, with around 40-min interval. The chasing during the first sampling was used as an acute stressor. The effects of sampling procedures on plasma cortisol and FCM levels are compared. Blood and feces were analyzed by an Enzyme-Linked Immunosorbent Assay (ELISA). Plasma cortisol and FCM levels increased within 40 min after fish perceived an acute stressor when the average weight of fish was below 100 g. Attenuated cortisol stress responses to acute stress were found after fish experiencing long-term stress. Collectively, FCM reflects changes in plasma cortisol and can be an alternative to analysis of plasma cortisol in Atlantic salmon, complementing evidence of using FCM as stress indicators for monitoring and improving fish welfare. The results highlight that standard sampling procedures and good experimental designs should be established to ensure robust and repeatable results in the study of stress based on the FCM measurement. Future study will investigate representative timepoints for FCM sampling, with particular attention to the types of stress and sizes of the fish.

A Preliminary Comparison of Beef Carcases Stunned using DTS: Diathermic Syncope® or Captive Bolt in Terms of Selected Meat Quality Attributes and Plasma Biomarker Concentrations

A novel technology for inducing unconsciousness prior to slaughter has been developed (DTS). For commercial reasons meat quality attributes are important, and impacts on endocrine responses provide an indication of animal welfare. We compared endocrine, ultimate pH and meat quality (after 1 and 10 weeks of storage) attributes of cattle carcases processed using DTS with those processed using penetrative captive bolt (CB). There were no significant differences between treatments in the change in plasma cortisol, adrenocorticotropic hormone, β-endorphin and catecholamines between baseline and immediately post-slaughter, and no significant differences in terms of pH at 24 h post slaughter. There were no significant differences in pH, shear force, TBARS or drip loss between DTS and CB samples of round and loin at week 1 and week 10 post slaughter; DTS meat was yellower at quartering (MINOLTA b* P &lt; 0.05). At week 1, DTS loins were redder (MINOLTA a*, P &lt; 0.05) and yellower (MINOLTA b*, P &lt; 0.05), while DTS rounds were lighter (MINOLTA L*, P &lt; 0.05), than CB. At week 10, there were no significant meat color differences between treatments. Processing cattle using DTS results in endocrine changes and meat quality attributes that are comparable to CB.

The effect of transdermal flunixin meglumine on blood cortisol levels in dairy calves after cautery disbudding with local anesthesia

The objective of this study was to evaluate the effect of the nonsteroidal anti-inflammatory drug transdermal flunixin meglumine (Finadyne Transdermal) on plasma cortisol, average daily weight gain, and standing and lying behavior of calves, when given at the time of disbudding combined with local anesthesia. A sedative was not used to minimize pharmacological interactions. Seventy-one female Holstein Friesian calves aged 13 ± 2 d, with an average weight of 48.9 ± 4.26 kg were enrolled in the study. All calves were randomly assigned to one of 3 treatment groups: (1) control group (CON, n = 27), (2) 1-flunixin group (1-FLU, n = 26) with a single administration of transdermal flunixin meglumine at disbudding, and (3) 2-flunixin group (2-FLU, n = 24) with 2 administrations of transdermal flunixin meglumine, the first treatment at disbudding and the second 6h after disbudding. Although the CON group received a placebo, 1-FLU and 2-FLU received flunixin meglumine transdermally. To account for plasma cortisol changes due to manipulation and handling of the calves, a sham disbudding procedure was performed one week before disbudding took place. Sham disbudding was conducted by using a cold cautery dehorner applied to each horn bud for 10 s. Disbudding was performed in a similar way by using a hot cautery dehorner. Plasma samples were collected to measure the stress biomarker cortisol at 7 different time points. Body weights were measured 4 times in 2 wk. Standing and lying behavior was assessed via 3-dimensional accelerometer. During sham disbudding and disbudding mean plasma cortisol concentrations were 6.09 ± 2.5 ng/mL and 5.16 ± 2.8 ng/mL, respectively. Treatment tended to have an effect on plasma cortisol concentrations during sham disbudding and had an effect on plasma cortisol concentrations during disbudding. Plasma cortisol concentrations were affected by treatment 2 h after disbudding in comparison to CON group. Furthermore, there was a significant effect on plasma cortisol concentrations 6 h after disbudding in contrast to CON. A return to baseline plasma cortisol levels (initial concentrations) was not achieved in CON during disbudding. There was no statistical difference between average daily weight gain and the treatment procedure. Total lying time was not affected by treatment after disbudding. In conclusion, transdermal flunixin meglumine given at the time of disbudding combined with local anesthesia decreased concentrations of the stress biomarker cortisol, but a second dose 6 h after disbudding had no further effect on plasma cortisol levels.

Effects of dietary glycine administration on biochemical responses to ammonia toxicity in common carp, Cyprinus carpio

The benefits of dietary glycine supplementation were investigated in common carp, Cyprinus carpio, following an acute ammonia challenge. Fish were fed diets supplemented with glycine (0, 2.5, 5 and 10 g/kg; named C, 2.5G, 5G and 10G, respectively) for 3 weeks, followed by 3-h exposure to 0.5 mg/L unionized ammonia nitrogen. Plasma immunoglobulin levels showed no changes in relation to ammonia challenge or dietary glycine supplementation. Dietary glycine significantly decreased plasma glucose, but increased plasma total antioxidant capacity (TAC) and glutathione (GSH). Ammonia exposure significantly increased plasma glucose and alternative complement, but decreased plasma GSH and TAC levels. Dietary glycine and ammonia exposure induced interaction effects on plasma ammonia, urea, cortisol, lysozyme, alanine aminotransferase (ALT), aspartate aminotransferase (AST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and malondialdehyde (MDA). Before ammonia exposure, glycine administration significantly decreased plasma ammonia and urea; after ammonia exposure, glycine supplementation significantly mitigated hyperammonaemia, but stimulated uraemia. Dietary glycine induced no changes in plasma cortisol before ammonia challenge, but decreased it after the ammonia challenge. Dietary glycine had no significant effects on ALT, AST, SOD and MDA, decreased CAT, but increased GPx and GST, before ammonia exposure. Moreover, dietary glycine mitigated the ammonia-induced elevations in ALT, AST, SOD, CAT, GPx, GST and MDA. Among the treatments, 10G exhibited the lowest ammonia-induced changes in the tested parameters; thus, it is recommended to use 10 g glycine per kg diet for 3 weeks to mitigate ammonia-induced stress, oxidative stress and hepatic damages in common carp.

Survival and Physiological Recovery after Capture by Hookline: The Case Study of the Blackspot Seabream (Pagellus bogaraveo)

Evaluating the survival of discarded species is gaining momentum after the new European Common Fisheries Policy (Article 15 of the European Regulation No. 1380/2013). This regulation introduced a discard ban, with an exemption for those species with demonstrated high survival rates after their capture and release. Candidate species should be evaluated for each fishing gear and geographical area. In this study, we assessed not only survival, but also physiological recovery rates of blackspot seabream (Pagellus bogaraveo) below commercial size captured with a hookline called “voracera” in the Strait of Gibraltar (SW Atlantic waters of Europe). Experiments onboard a commercial fishing vessel were paralleled with studies in controlled ground-based facilities, where the capture process was mimicked, and physiological recovery markers were described. Our results confirmed that hookline capture induced acute stress responses in the target species, such as changes in plasma cortisol, lactate, glucose, and osmolality. However, 90.6% of the blackspot seabreams below commercial size captured with this fishing gear managed to survive, and evidenced physiological recovery responses 5 h after capture, with complete homeostatic recovery occurring within the first 24 h. Based on this study, the European Commission approved an exemption from the discard (EU Commission Delegated Regulation 6794/2018). Thus, the robust methodology described herein can be an important tool to mitigate the problem of discards in Europe.

Pre-breeding androgen and glucocorticoid profiles in the eastern hellbender salamander (Cryptobranchus alleganiensis alleganiensis)

Seasonally breeding species exhibit cyclical changes in circulating steroid hormone profiles that correspond with changes to their reproductive behavior and ecology. Such information is critical to the conservation of imperiled and data-deficient species, such as the eastern hellbender salamander (Cryptobranchus alleganiensis alleganiensis). We determined changes in plasma testosterone (T), dihydrotestosterone (DHT), 11-ketotestosterone (11-KT), 11-ketoandrostenedione (11-KA), dehydroepiandrosterone (DHEA), cortisol, corticosterone, and progesterone (P4) during a four-month period preceding breeding in adult male and female eastern hellbenders. This pre-breeding period is characterized by increased diel movement and aggression by both sexes, follicular development and yolk production in females, and sperm production, territoriality, and nest site establishment in males. In both males and females, we observed a progressive increase in circulating T and DHT during the pre-reproductive season, both peaking in August (17 days before breeding), but concentrations of both hormones were higher in males. Conversely, 11-KT was higher in females, but did not vary significantly by date. These results suggest that T and DHT are the predominant androgens in eastern hellbenders and are likely important regulators of reproductive processes in both males and females. The detection of significant quantities of DHT and 11-KT in females is particularly interesting, considering that unlike T, neither of these androgens can be converted to estrogens. Therefore, it seems possible that aggression or some aspect of reproduction in the female eastern hellbender may be directly mediated by androgen signaling. Baseline cortisol did not vary throughout the pre-breeding period but was higher in females than males, and also became highly variable in females leading up to breeding. Progesterone, 11-KA, DHEA, and corticosterone were rarely or never detected, and thus, do not appear to be important during the pre-reproductive season. This study provides a physiological framework for future studies of hellbender reproductive biology, which could ultimately be important for their conservation.

Caffeine coingested with carbohydrate on performance recovery in national-level paddlers: a randomized, double-blind, crossover, placebo-controlled trial.

Caffeine enhances muscle glycogen resynthesis postexercise; however, the next-day effects on recovery are unknown. The present study aimed to examine the effects of carbohydrate (CHO) supplementation with or without caffeine (CAF) 24-h following exhaustive exercise on time trial performance in elite paddling athletes. Nine highly trained male paddlers (21±2 y) completed three experimental trials in a randomized, double-blind, crossover manner. Following an exhaustive exercise session (20-km timed paddle) participants ingested: 1) 0.6 g/kg of carbohydrate (CHO); 2) 0.6 g/kg of carbohydrate with 6 mg/kg of caffeine (CAF+CHO); or 3) placebo (PLA), at four time-points (immediately after, and 2, 6, and 12-h postexercise) in addition to their typical dietary intake. After 24 h, 5 attempts of on-water 500-m paddling time-trial was performed, and the average time was recorded. Blood samples were taken at rest and following both the 20-km and the 5×500 m exercise to determine changes in plasma cortisol, insulin, and glucose. There was a significant main effect of condition (P<0.001), with post-hoc analysis revealing that both CHO conditions (CHO: 98.7±2.8 s, P=0.0003; CAF+CHO: 97.9±2.3 s, P=0.0002) were significantly faster compared to PLA (101.0±3.1 s); however, CAF did not augment time trial performance compared to CHO (P=0.16). There was no significant condition by time interactions for glucose, cortisol, or insulin before and after the 20-km depleting exercise and 500-m time trial. In elite male paddlers, CHO, independent of caffeine, enhanced time trial performance 24 hours following exhaustive exercise.

Effects of dietary phytol supplementation on growth performance, immunological parameters, antioxidant and stress responses to ammonia exposure in common carp, Cyprinus carpio (Linnaeus, 1758)

The present study aimed to investigate the effects of dietary phytol on growth performance, humoral immune parameters, antioxidant and biochemical responses of common carp, Cyprinus carpio, to ammonia toxicity. Diets containing four concentrations of phytol (mg kg−1): 0 (CTRL), 125 (PH125), 250 (PH250), and 500 (PH500) were fed to the fish (average weight: 26 ± 0.5 g) for 78 days; then the fish were exposed to 0.5 mg L−1 unionized ammonia nitrogen. According to the results, growth performance and survival were similar among the treatments. Dietary phytol supplementation significantly increased plasma total immunoglobulin (Ig) and complement (ACH50); the highest ACH50 levels were observed in PH250 and PH500 treatments, as the highest globulin and Ig levels were observed in PH250 treatment. In addition, PH250 and PH500 treatments presented significantly higher plasma lysozyme activity compared to CTRL, with the highest activity in PH250 treatment. Dietary phytol induced no changes in plasma cortisol, alanine aminotransferase and aspartate amino transferase, and hepatic malondialdehyde levels before ammonia exposure; whereas, it increased hepatic superoxide dismutase (PH125, PH250, PH500), catalase (PH250, PH500), glutathione peroxidase (PH125), plasma total antioxidant capacity (PH125, PH250, PH500) and decreased plasma glucose (PH125, PH250), and malondialdehyde (PH125, PH250). Ammonia exposure led to elevations in plasma cortisol, glucose, alanine aminotransferase, aspartate amino transferase, malondialdehyde and hepatic antioxidant enzymes and malondialdehyde levels; but decreased plasma total antioxidant capacity. Dietary phytol mitigated the changes in plasma cortisol, glucose, malondialdehyde, alanine aminotransferase, aspartate aminotransferase, total antioxidant capacity, and hepatic malondialdehyde levels, particularly at 125 and 250 mg kg−1 levels. On the other hand, the phytol-treated fish exhibited higher elevation in hepatic antioxidant enzymes after ammonia exposure, compared to CTRL. In conclusion, the present results indicate phytol is an immunostimulant in common carp and can stimulate antioxidant system to protect the fish against oxidative stress caused by ammonia exposure.

The Effect of Continuous Stress on Spatial Learning and Memory, Anxiety-Like Behavior, and Depression in Male NMRI Mice

The present study examined the effect of continuous immobilization stress on anxiety-like behavior, spatial learning and memory, and a forced swim test in NMRI male mice. The plasma cortisol changes and the brain-derived neurotrophic factor (BDNF) were also evaluated. The male NMRI mice were divided into control and stress groups (n = 10/group). The stress group was placed in restrained PVC tube for 360 min. Twenty-four hours later, the mice were tested for spatial learning and memory, anxiety-like behavior, and depression using the Barnes maze, an elevated plus maze, and a forced swim test, respectively. Also, the plasma cortisol level and the brain BDNF content were assessed by the ELISA method. Results indicated that the mice in the stress group had an elevated plasma cortisol level. There were no differences between the stress and control groups in the time taken and the distance traveled to reach the target hole. The animals in the stress group spent more time in the open arms of the maze and in entering the open arms, compared to the control group. Continuous immobilization stress caused a significant decrease in swim time for the animals in the stress group, compared to the control group. The brain BDNF concentration also found to be significantly in the stress group than the control group. In conclusion, acute sustained stress increases the brain BDNF level. It can facilitate anxiety-like behavior and depression, which may be due to a plasma glucocorticoid increment. However, the stress does not affect spatial learning and memory.

High hydrostatic pressure effects on arginine vasotocin levels in fish

The present study investigates the response of the hormone arginine vasotocin (AVT), the non-mammalian antidiuretic hormone, to the acclimation of fish to high hydrostatic pressure (5.1 MPa). Two fish species with different osmoregulatory strategies, the lesser spotted dogfish Scyliorhinus canicula, a marine osmoconforming chondrichthyan species adapted for migration to deep waters, and the rainbow trout Oncorhynchus mykiss, a pressure-sensitive freshwater species, were selected for study. Fish were exposed to hydrostatic pressures of either 0.1 (control) or 5.1 MPa in hydrostatic chambers for up to 2 wk at their appropriate salinities. Plasma cortisol was measured in trout, and plasma chloride, sodium and potassium were measured in both fish species. A transient high level of plasma AVT was found in dogfish and in trout after 1 and 3 d of exposure to high hydrostatic pressure, which returned to basal levels by 14 d of exposure. In contrast, pituitary AVT content was reduced after short-term exposure in dogfish, while in trout, lower expression was found in high pressure than in control conditions, independently of exposure time. In dogfish, pituitary AVT levels recovered by 14 d under high hydrostatic pressure. No changes in plasma cortisol (trout) or ions (both species) were observed. These initial increases of the AVT release from the pituitary during fish acclimation to high pressure suggest that it works as a physiological short-term response to reduce water loss and equilibrate ion osmotic balance.

Perioperative probiotic treatment decreased the incidence of postoperative cognitive impairment in elderly patients following non-cardiac surgery: A randomised double-blind and placebo-controlled trial.

Given that population aging is a global health challenge, the high prevalence of postoperative neurocognitive impairment in elderly patients necessitates the development of novel simple and effective prevention methods. To evaluate the effects of perioperative application of oral probiotic as a prophylaxis for cognitive impairment in elderly patients following non-cardiac surgery. This randomised double-blind and placebo-controlled trial included 120 elderly patients (in a modified intention-to-treat analysis) scheduled for elective orthopaedic or colorectal surgery. Patients were assigned to receive either probiotics or a placebo from hospital admission until discharge. The primary endpoint was the incidence of postoperative cognitive impairment, defined as a decrease of ≥3 points in the Mini-Mental State Examination (MMSE) scores from admission baseline to the 7th day post-surgery. Secondary endpoints included changes in plasma interleukin-6 (IL-6) and cortisol, postoperative pain intensity, postoperative sleep quality, gastrointestinal function recovery, and faecal microbiota composition. The incidence of postoperative cognitive impairment in the probiotic group was significantly lower than in the control group (3 of 59 patients [5.1%] vs. 10 of 61 patients [16.4%], P=0.046). In addition, compared to pre-surgery, the levels of plasma IL-6 and cortisol in the probiotic group decreased more than in the control group 5-7 days after surgery (IL-6:-117.90±49.15 vs.-14.93±15.21, P=0.044; cortisol:-158.70±53.52 vs. 40.98±72.48, P=0.010). Relative abundance at the genus level in the faeces of the probiotic group also changed more than in that of the control group during the perioperative period. In contrast, postoperative pain intensity, sleep quality, and gastrointestinal function recovery did not differ significantly between the two groups. Perioperative application of oral probiotic prevents postoperative cognitive impairment in elderly patients following non-cardiac surgery, possibly via the limitation of peripheral inflammation and the stress response.

Physiological responses of farmed Atlantic salmon and two cohabitant species of cleaner fish to progressive hypoxia

To mitigate salmon lice infestations in Atlantic salmon (Salmo salar) sea cages, deployment of cleaner fish have become a widespread strategy. However, species of cleaner fish may experience poor welfare in the highly fluctuating farm environment owing to differences in physiological adaptations and niche requirements. In particular, occurrences of reduced oxygen levels are common in salmon cages. The purpose of this study was therefore to compare hypoxia responses of Atlantic salmon and two commonly used cleaner fish species, the lumpfish (Cyclopterus lumpus) and the ballan wrasse (Labrus bergylta). We used respirometry to measure metabolic rates (MO2) during progressive hypoxia down to 20% oxygen saturation. In addition, we also measured key haematological parameters before, during and after hypoxia exposure. While all fish survived exposure down to 20% oxygen saturation, distinct differences in metabolic and haematological responses were found, reflecting species specific adaptations and lifestyles. In Atlantic salmon, MO2 was independent of ambient oxygen levels until 27% saturation, after which it decreased linearly. In lumpfish, MO2 steadily decreased throughout the hypoxia trial. In ballan wrasse, MO2 was notably lower than in the other species and unaffected by the levels of hypoxia encountered. Hypoxia induced changes in plasma cortisol, plasma lactate and plasma osmolality were substantially greater in Atlantic salmon compared to both cleaner fish species. This suggests that similar magnitudes of hypoxia exposure were more stressful to Atlantic salmon. Hence, neither cleaner fish species should be in immediate danger as long as hypoxia levels that are known to be detrimental to Atlantic salmon are avoided. However, lumpfish had markedly reduced activity levels at the early onset of progressive hypoxia, and is therefore likely to require near normoxic conditions to efficiently function as cleaner fish.

Leech (Myzobdella lugubris) infestations in largemouth bass (Micropterus salmoides) in Back Bay, Virginia, USA.

Back Bay is an oligohaline, coastal bay in southeast Virginia, USA. Since 2004, leeches have been observed in the oral cavities of largemouth bass (Micropterus salmoides) in this body of water. Leeches (Myzobdella lugubris) have previously been documented in the oral cavities of largemouth bass in the Currituck Sound, which is confluent with Back Bay on its southern border. Supplemental stocking of largemouth bass in Back Bay since 2009 has resulted in an increasing population; however, concern exists that leech infestation may be negatively affecting health of larger fish, which are still less abundant than expected. Despite the wide distribution of this leech, there is little available literature regarding its health impacts on hosts. In this study, we examine potential impacts of oral leech infestations on stress markers and haematological parameters of largemouth bass in Back Bay. No significant changes in plasma glucose or cortisol were observed between leech-infested and uninfested fish, and haematological parameters were not significantly different between the groups. Further, there was no evidence of systemic infections associated with leech infestation.

Strengthening sleep-autonomic interaction via acoustic enhancement of slow oscillations.

Slow-wave sleep (SWS) is important for overall health since it affects many physiological processes including cardio-metabolic function. Sleep and autonomic nervous system (ANS) activity are closely coupled at anatomical and physiological levels. Sleep-related changes in autonomic function are likely the main pathway through which SWS affects many systems within the body. There are characteristic changes in ANS activity across sleep stages. Notably, in non-rapid eye-movement sleep, the progression into SWS is characterized by increased parasympathetic activity, an important measure of cardiovascular health. Experimental manipulations that enhance slow-wave activity (SWA, 0.5-4 Hz) can improve sleep-mediated memory and immune function. However, effects of SWA enhancement on autonomic regulation have not been investigated. Here, we employed an adaptive algorithm to deliver 50 ms sounds phase-locked to slow-waves, with regular pauses in stimulation (~5 s ON/~5 s OFF), in healthy young adults. We sought to determine whether acoustic enhancement of SWA altered parasympathetic activity during SWS assessed with heart rate variability (HRV), and evening-to-morning changes in HRV, plasma cortisol, and blood pressure. Stimulation, compared with a sham condition, increased SWA during ON versus OFF intervals. This ON/OFF SWA enhancement was associated with a reduction in evening-to-morning change of cortisol levels and indices of sympathetic activity. Furthermore, the enhancement of SWA in ON intervals during sleep cycles 2-3 was accompanied by an increase in parasympathetic activity (high-frequency, HRV). Together these findings suggest that acoustic enhancement of SWA has a positive effect on autonomic function in sleep. Approaches to strengthen brain-heart interaction during sleep could have important implications for cardiovascular health.

The influence of tropical thermal stress on the seasonal and diurnal variations in the physiological and oxidative status of Karan Fries heifers

ABSTRACT The changes in plasma cortisol, oxidative status, skin temperature and physiological responses of Karan Fries heifers were monitored during thermoneutral (TN; THI = 73), hot-dry (HD; THI = 83) and hot-humid (HH; THI = 85) seasons. Six heifers (age = 14-I8 months) were followed during each season. All the physiological measures viz. rectal temperature (RT), respiration rate (RR) and pulse rate (PR) displayed a diurnal rhythm and were higher (p < 0.05) in the evening as compared to the morning with maximum variations seen in HH season. The skin temperature (dorsal, abdomen and ear) increased (p ˂ 0.05) in hot seasons mainly in HD as compared to TN season. A significant (p < 0.05) increase was observed in the concentration of plasma cortisol, superoxide dismutase (SOD) and malondialdehyde (MDA) during hot seasons compared to TN season. All the recorded physiological and oxidative parameters were positively correlated with the temperature-humidity index (THI). However, the dry matter intake was negatively correlated with THI during all seasons. The results reveal that the heifers exhibited more signs of heat stress during HD and HH seasons which were reflected by higher concentrations of cortisol, SOD, MDA and more deviation in the normal daily rhythm of various physiological functions.