Attenuation Of Stress Response Research Articles

Comparison of Magnesium Sulphate and Dexmedetomidine for Attenuation of Stress Response in Patients undergoing Laparoscopic Cholecystectomy under General Anaesthesia by Measuring Biochemical Markers of Stress Response: A Prospective Randomized Study

Background: Laryngoscopy, endotracheal intubation, pneumoperitoneum creation and extubation is stressful event marked by hemodynamic changes during laparoscopic procedures. This increases secretion of many biochemical stress markers for example, cortisol levels, TNF-alpha levels, CRP levels, blood Sugar levels. Aim of the study was to compare magnesium sulphate and dexmedetomidine for attenuation of stress response in patients undergoing laparoscopic cholecystectomy under general anaesthesia by measuring biochemical markers of stress response.
 Methods: 60 patients, age between 18 to 60 years of either sex, who were undergoing Laparoscopic cholecystectomy randomized into two groups of 30 patients each by computer generated random number. Group M- received magnesium sulphate 50 mg/kg and group D - received dexmedetomidine 1 µg/kg.
 Results: The demographic data were comparable in both groups. Cortisol levels rise in both the groups but significantly more in group M than group D at 30 minute (p-value < 0.001) and 4 hours (p-value < 0.001). CRP levels rise in both the groups but significantly more in group M than group D at 30 min (p-value 0.013) and 4 hours (p-value 0.020). Blood sugar levels rise in both the groups but significantly more in group M than group D at 30 min, 4 hours and 24 hours (p-value <0.001). TNF-alpha levels rise in both the groups but significantly more in group M than group D at 30 min (p-value 0.005) and 4 hours (p-value 0.007).
 Conclusion: We conclude that biochemical stress marker levels (Cortisol levels, TNF-alpha, levels, CRP levels, Blood Sugar levels) were more increased in the magnesium sulphate group compared with the dexmedetomidine group. Heart rate and Mean arterial pressure were higher in the Magnesium sulphate group than the Dexmedetomidine group. Dexmedetomidine is better than magnesium sulphate in attenuating the stress of surgery in patients undergoing laparoscopic cholecystectomy.

Efficacy and safety of dexmedetomidine in attenuating stress response to skull pin holder application in patients undergoing craniotomy

Background: Skull pin holder application during craniotomy can evoke stress response, which might lead to sudden rise in blood pressure (BP), causing intracranial hemorrhage, cerebral edema, and prolonged hospital stay. Dexmedetomidine has been shown to blunt the sympathoadrenal response to surgery. Aims and Objectives: The present study was undertaken to assess the efficacy and safety of dexmedetomidine in attenuating stress responses to skull pin holder application as compared to normal saline. Materials and Methods: After obtaining approval from the institutional ethics committee and written informed consent, patients of either sex undergoing elective craniotomy at the attached hospitals of Bangalore Medical College and Research Institute, Bengaluru, India, were randomized in a 1:1 ratio to receive normal saline or dexmedetomidine as premedication. Hemodynamic parameters, i.e., heart rate (HR), systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP), were monitored at various time points until 30 min after skull pin application. Data were analyzed using the chi-squared test, repeated measure ANOVA, unpaired t-test, and Mann–Whitney U test, wherever applicable. Results: A total of 52 patients were included in the study, with 26 patients in each group. All the baseline parameters were matched. As a stress response, a significant increase in HR was seen after intubation (90.69 bpm) and skull pin insertion (87.92 bpm) in the normal saline group. However, there was no significant variation in HR in the dexmedetomidine group over 30 min (69.19 bpm–74.15 bpm). Dexmedetomidine reduced HR significantly as compared to normal saline after intubation (P = 0.03). Dexmedetomidine lowered SBP and DBP as compared to baseline throughout 30 min without any excursions during intubation and skull pin insertion. The SBP was significantly lower in the dexmedetomidine group after intubation as compared to saline (P = 0.02). Although a reduction in SBP was noted after skull pin insertion in the dexmedetomidine group, it was not statistically significant than saline. No significant difference was noted in DBP, MAP, or blood glucose between the two groups. No incidents of hypotension and bradycardia were noted. Conclusion: Dexmedetomidine maintained basal HR throughout 30 min without any variations in response to intubation and skull pin insertion. It also reduced SBP and DBP over 30 min. HR and SBP were significantly lower in the dexmedetomidine group as compared to saline after intubation. The same effect was noted in the dexmedetomidine group as compared to saline after skull pin insertion, but it was not statistically significant.

Oral Clonidine versus Ivabradine for Attenuating Stress Response in Functional Endoscopic Sinus Surgery: A Randomised Placebo-controlled Study

Introduction: Peri-anaesthetic haemodynamic alterations, such as hypertension and tachycardia, can cause increased bleeding during Functional Endoscopic Sinus Surgery (FESS), impairing the visibility of the surgical field and resulting in scarring, adhesions, and prolonged surgery time. Various strategies involving pharmacological techniques have been used to mitigate these unfavourable reflexes. Alpha-2 agonists, such as Clonidine, are currently being employed to attenuate sympathoadrenal stimulation caused by tracheal intubation and surgery. Ivabradine is a new drug that selectively lowers Heart Rate (HR) by inhibiting cardiac funny current channels. Aim: To compare the effects of premedication with oral Clonidine versus oral Ivabradine on attenuating haemodynamic stress response and improving the quality of the surgical field in FESS. Materials and Methods: The present randomised, placebocontrolled, double-blind study was conducted in the Department of Anaesthesiology and Intensive care at Rajendra Hospital, Government Medical College, Patiala, Punjab, India from April 2021 to December 2022 on 90 American Soceity of Anaesthelogists ( ASA) Physical status I and II adult patients (aged 18-60 years) undergoing FESS. Group A (n=30) received oral Ivabradine 5 mg, Group B (n=30) received oral Clonidine 0.2 mg, and Group C (n=30) received oral placebo tablets 2 hours before surgery. Haemodynamic parameters, including HR and Mean Arterial Pressure (MAP), quality of the intraoperative surgical field, postoperative sedation score, Visual Analogue Scale (VAS) score, time to analgesia request, blood loss, and adverse effects, were recorded. Descriptive statistics were used to calculate mean±Standard Deviation (SD) and percentage. Analysis of Variance (ANOVA), Tukey post-hoc test, Kruskal-wallis H test, and Pearson’s Chi-square were applied as appropriate. Results: The mean ages were 33.87±12.84, 35.03±12.93, and 40.9±14.46 years for Groups A, B, and C, respectively. The mean weights were 60.5±8.91, 57.83±5.66, and 57.9±5.42 kg, and the mean duration of surgery was 88.67±4.29, 88.8±4.29, and 88.03±3.93 minutes for Groups A, B, and C, respectively. There were no significant differences in terms of gender, ASA score, and type of surgery between the groups. Baseline HR and MAP were comparable among the groups. HR was significantly lower in both Groups A and B compared to Group C at all time intervals (p-value <0.001). Both drugs significantly attenuated tachycardia and hypertension in response to cardiovascular stress induced by laryngoscopy, endotracheal intubation, and extubation. However, Group B showed significantly better control of MAP throughout the intraoperative period and at extubation. The average category scale score, estimated blood loss, and postoperative VAS Score were all significantly lower in Group B than in Group A. Postoperative sedation scores were significantly higher in Group B, and the time to first rescue analgesic was longest in Group B (p<0.05). No significant side effects were observed. Conclusion: Both Clonidine and Ivabradine effectively attenuated the haemodynamic stress response. Clonidine provided better control of MAP, resulting in reduced bleeding, improved operative field visibility, and lower postoperative analgesic requirements compared to Ivabradine.

NUCB2/nesfatin-1 in the acute stress response of obese women with high and low anxiety

NUCB2/nesfatin-1 is an anorexigenic peptide hormone first known for its effects on energy homeostasis. More recently, a growing evidence suggests a role of NUCB2/nesfatin-1 in emotion regulation, particularly in the modulation of anxiety, depression and emotional stress response. Since stress-related mood disorders are often comorbid with obesity, we investigated the effect of acute psychosocial stress on circulating NUCB2/nesfatin-1 in obese women and normal-weight controls and its association with symptoms of anxiety. Forty women, 20 obese and 20 normal-weight controls, (aged between 27 and 46 years) were exposed to the Trier Social Stress Test (TSST). We assessed changes of plasma NUCB2/nesfatin-1, salivary cortisol, heart rate and subjective emotional state. Symptoms of anxiety (GAD-7), depressiveness (PHQ-9), perceived stress (PSQ-20), disordered eating (EDE-Q, EDI-2) and health-related quality of life (SF-8) were measured psychometrically. Obese women were further subdivided in a high and low anxiety group. Women with obesity displayed higher psychopathology compared to normal-weight controls. The TSST induced a biological and psychological stress response in both groups (p < 0.001). In normal-weight controls NUCB2/nesfatin-1 increased in response to stress (p = 0.011) and decreased during recovery (p < 0.050), while in obese women only the decrease during recovery was significant (p = 0.002). Obese women with high anxiety displayed higher NUCB2/nesfatin-1 levels than those in the low anxiety group (TSST: +34 %, p = 0.008; control condition: +52 %, p = 0.013).Our data substantiate the involvement of NUCB2/nesfatin-1 in the modulation of stress and anxiety. It remains unclear whether the attenuated stress response in obese subjects is due to metabolic changes or mental comorbidity.

A COMPARATIVE STUDY OF INTRAVENOUS DEXMEDETOMIDINE, ESMOLOL AND FENTANYL FOR ATTENUATION OF HEMODYNAMIC RESPONSES TO LARYNGOSCOPY AND ENDOTRACHEAL INTUBATION IN PATIENTS UNDERGOING LAPAROSCOPIC CHOLECYSTECTOMY UNDER GENERAL ANAESTHESIA

The aim is to evaluate and compare the relative efficacy of intravenous dexmedetomidine, Esmolol and Fentanyl for attenuation of stress responses following laryngoscopy and endotracheal intubation in adult patients undergoing laparoscopic cholecystectomy under general anaesthesia

Loss of regulation of protein synthesis and turnover underpins an attenuated stress response in senescent human mesenchymal stem cells

Cells respond to stress by synthesizing chaperone proteins that seek to correct protein misfolding and maintain function. However, abrogation of protein homeostasis is a hallmark of aging, leading to loss of function and the formation of proteotoxic aggregates characteristic of pathology. Consequently, discovering the underlying molecular causes of this deterioration in proteostasis is key to designing effective interventions to disease or to maintaining cell health in regenerative medicine strategies. Here, we examined primary human mesenchymal stem cells, cultured to a point of replicative senescence and subjected to heat shock, as an invitro model of the aging stress response. Multi -omics analysis showed how homeostasis components were reduced in senescent cells, caused by dysregulation of a functional network of chaperones, thereby limiting proteostatic competence. Time-resolved analysis of the primary response factors, including those regulating heat shock protein 70 kDa (HSPA1A), revealed that regulatory control is essentially translational. Senescent cells have a reduced capacity for chaperone protein translation and misfolded protein (MFP) turnover, driven by downregulation of ribosomal proteins and loss of the E3 ubiquitin ligase CHIP (C-terminus of HSP70 interacting protein) which marks MFPs for degradation. This limits the cell's stress response and subsequent recovery. A kinetic model recapitulated these reduced capacities and predicted an accumulation of MFP, a hypothesis supported by evidence of systematic changes to the proteomic fold state. These results thus establish a specific loss of regulatory capacity at the protein, rather than transcript, level and uncover underlying systematic links between aging and loss of protein homeostasis.

Radical Cystectomy as a Cause of an Increased Neuroendocrine Response

The present study compared the neuroendocrine response in patients undergoing conventional cystectomy with two postoperative pain management techniques: epidural analgesia (EA) and intermittent opioid analgesia (IOA) on adrenocorticotropic hormone (ACTH), cortisol, glucose levels for 48 hours. We hypothesize that appropriate analgesic regime can attenuate stress response reaction. Forty-four patients scheduled for radical conventional cystectomy were assigned to one of the two study groups: group A (n=22) with EA, group B (n=22) with IOA. The surgical stress factor induced significant hypothalamic-pituitary-adrenal (HPA) axis responses in both groups. The ACTH and cortisol levels were higher than baseline for both groups, but more significantly in group B. Blood glucose level was elevated few hours after the surgical intervention and was back to baseline level by the following morning. The results suggest that EA might have more advantages associated with reduced postoperative pain and attenuated neuroendocrine response when open access is the preferred operative technique. There is a need of randomized multicentre trials to evaluate the quality of life, the survival and the role of pain management at least 12 months after radical cystectomy.

Focus on host/organ unregulated response: a common cause of critical illness.

Focus on host/organ unregulated response: a common cause of critical illness.

A randomized comparative study of preoperative fentanyl and dexmedetomidine nebulization on the hemodynamic response to endotracheal intubation

Background: Intense sympathetic activity is linked to laryngoscopy and endotracheal intubation, which could lead to intraoperative problems. We undertook this study to compare the effects of preoperative nebulized Fentanyl and Dexmedetomidine on hemodynamic response to laryngoscopy and endotracheal intubation, taking advantage of their high bioavailability and better absorption through nasal mucosa. Aim and Objectives: The objectives of the study were (i) to compare the effect of preoperative nebulization on the hemodynamic response to laryngoscopy and intubation; and (ii) to assess intraoperative requirement of anesthetic agents. Materials and Methods: This prospective, randomized, and comparative study was conducted among 100 American Society of Anesthesiologists (ASA) I, II patients (of either gender) undergoing elective surgeries and requiring tracheal intubation, were randomized in two groups. Group A was given Fentanyl Nebulization (2 μg/kg in 4 ml of 0.9% saline) and Group B was given Dexmedetomidine nebulization (1 μg/kg in 4 ml of 0.9% saline) 10 min before anesthesia induction. Hemodynamic parameters were noted before and immediately after induction, 1 min, 5 min and 10 min after intubation. The main goal was to assess how Fentanyl and dexmedetomidine nebulization affect the laryngoscopy and intubation-induced stress response. The secondary outcome was to assess the intraoperative requirement of anesthetic agents, observe adverse effects of study drug and sedation score. Results: Dexmedetomidine nebulization was found to be more effective in blunting rise in heart rate post laryngoscopy compared to Fentanyl Nebulization (P &lt; 0.0001) as well as in MAP after 10 min of intubation (P &lt; 0.0001). Requirement of propofol was seen to be significantly reduced in Group B compared to Group A (P &lt; 0.05). Sedation scores were significantly higher in Group B (P &lt; 0.05). No evidence of side effects was observed in any group. Conclusion: Nebulisation of dexmedetomidine was found to be more effective in attenuation of stress response of laryngoscopy and intubation compared to nebulisation of fentanyl, with stable intraoperative hemodynamic and no significant side effects.

Gill Oxidative Stress Protection through the Use of Phytogenics and Galactomannan Oligosaccharides as Functional Additives in Practical Diets for European Sea Bass (Dicentrarchus labrax) Juveniles.

The aim of the present study is to evaluate the potential of two functional additives as gill endogenous antioxidant capacity boosters in European sea-bass juveniles fed low-FM/FO diets when challenged against physical and biological stressors. For that purpose, two isoenergetic and isonitrogenous diets with low FM (10%) and FO (6%) contents were supplemented with 5000 ppm plant-derived galactomannan-oligosaccharides (GMOS) or 200 ppm of a mixture of garlic and labiate plant essential oils (PHYTO). A control diet was void from supplementation. Fish were fed the experimental diet for nine weeks and subjected to a confinement stress challenge (C challenge) or a confinement stress challenge combined with an exposure to the pathogen Vibrio anguillarum (CI challenge). Both GMOS and PHYTO diets attenuated fish stress response, inducing lower circulating plasma cortisol and down-regulating nfκβ2 and gr relative gene-expression levels in the gill. This attenuated stress response was associated with a minor energetic metabolism response in relation to the down-regulation of nd5 and coxi gene expression.

Interactions between symptoms and psychological status in irritable bowel syndrome: An exploratory study of the impact of a probiotic combination.

Stress is an exacerbator of irritable bowel syndrome (IBS) symptoms, and anxiety and depression are co-morbidities. Bifidobacterium longum strains 1714® and 35642® attenuate stress responses in healthy people and reduce symptoms in IBS, respectively. Here, we explore relationships between the psychological and visceral effects of the two strains (COMBO) in IBS subjects and biomarkers of stress and inflammation. We recruited 40 patients with IBS (Rome III) and mild to moderate anxiety (HADS-A) and/or depression (HADS-D) and 57 asymptomatic female controls with low or moderate stress. IBS patients were fed COMBO (1 × 109 cfu/day) for 8 weeks with an 8-week washout. IBS symptoms, psychometric measures, salivary cortisol awakening response (CAR), and plasma inflammatory biomarkers were assessed every 4 weeks. Compared to healthy controls, IBS subjects had a blunted CAR. Treatment with COMBO restored CAR and improved IBS symptoms compared to baseline during the treatment phase. The COMBO reduced HADS-D, HADS-A score, and TNF-α, while sleep quality improved significantly from baseline to the end of the intervention. Surprisingly, these parameters improved further once treatment ended and maintained this improvement by Week 16. These findings suggest that the stress response is a major driver of IBS symptoms. The time course of the beneficial effect of COMBO on IBS symptoms suggests that this is achieved through a restoration of the stress response. In contrast, the time course of the effects of COMBO on anxiety and depression in IBS paralleled an anti-inflammatory effect as indicated by a reduction in circulating levels of TNF-α.

A Comparative Study of Intravenous Dexmedetomidine with Local Infiltration of Ropivacaine in Attenuation of Stress Response to Skull Pin Insertion in Craniotomies.

Objective Skull pin insertion in patients undergoing craniotomies elicits hemodynamic and neuroendocrine stress response that may be deleterious to the patient. Various drugs and techniques have been documented in literature to abate this stress response. Against this background, we aimed to compare the efficacy of intravenous dexmedetomidine and local infiltration of ropivacaine for attenuation of stress response to pin insertion in craniotomies. Methods Eighty-eight adult patients undergoing craniotomy under general anesthesia from March 2019 to April 2020 requiring application of head holder were randomized into two equal groups. After intubation, 0.75 µg kg -1 of dexmedetomidine over 10 minutes through infusion was given in group D, while local infiltration at pin sites was done with 0.5% ropivacaine, 2 mL at each site in group R. Hemodynamic parameters and levels of serum cortisol, prolactin, and blood glucose were measured before and after pin insertion. Unpaired t -test for continuous variables and Mann-Whitney U test was used for nonnormally distributed variables. Results Heart rate was statistically similar between the two groups at all the observed time points. The difference in mean arterial pressure values between the two groups was found to be statistically significant only from 10 to 20 minutes after pin insertion being statistically similar at rest of the time points. Levels of serum glucose, cortisol, and prolactin values 30 minutes after pin insertion were statistically similar between both groups. Conclusion We concluded that both interventions are equally efficacious in attenuation of hemodynamic and stress response to head holder application in patients undergoing craniotomies.

Intranasal administration of neuropeptide Y significantly antagonized stress-induced colonic dysmotility via central GABAA receptors in male rats.

Stress plays a major role in the pathogenesis of many diseases. Central neuropeptide Y (NPY) counteracts the biological actions of corticotropin-releasing factor (CRF) and attenuates stress responses. Intracerebroventricular (ICV) administration of NPY significantly antagonized the inhibitory effects of chronic complicated stress (CCS) on gastrointestinal (GI) dysmotility in rats. However, ICV administration is an invasive technique. The effect of intranasal administration of NPY on the hypothalamus-pituitary-adrenal (HPA) axis and GI motility in CCS conditions have not been studied, and the inhibitory mechanism of NPY on CRF through the γ-aminobutyric acid (GABA)A receptor needs to be further investigated. A CCS rat model was set up, and NPY was intranasally administered every day before the stress loading. Furthermore, ICV administration of a GABAA receptor antagonist was performed daily. Hypothalamic CRF and NPY expressions were evaluated, serum corticosterone and NPY levels were analyzed, and colonic motor functions were assessed. CCS rats showed significantly increased CRF expression and corticosterone levels, which resulted in enhanced colonic motor functions. Intranasal NPY significantly increased hypothalamic NPY mRNA expression and reduced CRF mRNA expression and plasma corticosterone levels, helping to restore colonic motor functions. However, ICV administration of the GABAA receptor antagonist significantly abolished these effects induced by NPY. In conclusion, intranasal administration of NPY upregulates the hypothalamic NPY system. NPY may, through the GABAA receptor, significantly antagonize overexpressed central CRF and attenuate HPA axis activity in CCS conditions, influencing and helping to restore colonic motor function.

To compare effects of pretreatment with two doses of dexmedetomidine on etomidate induced myoclonus and attenuation of stress response at intubation

Etomidate’s haemodynamic stability is due to its unique lack of effect on the sympathetic nervous system and on baroreceptor function. Even in cardiac patients an induction dose of etomidate results in very stable haemodynamics. Etomidate also has minimal effects on respiratory system as compared to other induction agents. Since it causes minimal histamine release, this gives an advantage in patients with reactive airway disease, making it less likely that they will have bronchospasm. However, pain on injection and myoclonus are two most common side effects of this drug. Pain on injection has disappeared after the new fat emulsion of etomidate, but the new solvent has not reduced the incidence of myoclonus.1): To compare the effects of pretreatment with two doses of Dexmedetomidine on the incidence of Etomidate induced myoclonus using numerical based grading; 2): To compare the effects of pretreatment with two doses of Dexmedetomidine on attenuation of stress response at laryngoscopy and intubation after induction with Etomidate.Study area: The proposed study was carried out in the Department of Anesthesiology and Intensive care at a tertiary care teaching hospital, after seeking clearance from the college ethical committee and obtaining written informed consent from patient. Study design: Prospective Interventional Randomized Comparative Study Study period: 1 year It was a prospective and interventional randomized comparative study where 180 patients with age group 18-65 years, of either sex,ASA grade I &amp; II, BMI, undergoing elective surgical procedures under general anaesthesia with endotracheal intubation were included in the study. They were divided into three groups where patients were randomly allocated into one of the three groups using Block Randomization with sealed envelope system. In Group 2 and 3, 78.3% and 76.6% patients did not have myoclonus during induction with etomidate. Stress response to intubation was suppressed by dexmedetomidine. Based on the observations of our study, we conclude that pretreatment with 0.5µg/kg and1µg/kg Dexmedetomidine significantly reduce etomidate induced myoclonus and stress response at intubation. However, dexmedetomidine in dose of 0.5µg/kg is associated with fewer side effects of bradycardia and hypotension.

Effect of single bolus dose of intravenous magnesium sulfate in attenuating hemodynamic stress response to laryngoscopy and nasotracheal intubation in maxillofacial surgeries

Background: Nasotracheal intubation alters respiratory and cardiovascular physiology by reflex response mediated by both sympathetic and parasympathetic nervous systems and by the physical presence of the nasotracheal tube. Hypertension and tachycardia are the most common responses to intubation mediated by sympathetic efferent through cardio accelerator nerve and sympathetic chain ganglia. MgSO4 inhibits catecholamine release from adrenergic nerve endings and adrenal medulla resulting in attenuation of stress response. Aims and Objectives: In this study, we observed the effects of MgSO4 on the hemodynamic stress response. Materials and Methods: This prospective randomized controlled study was conducted on 60 patients after approval of the Institutional Ethics and Scientific Review committee over the period of 1 year. They were divided into two groups, Group M (MgSO4 group) received 40 mg/kg of intravenous magnesium sulfate in 100 ml normal saline and Group C (control group) received normal saline 10 min before induction. Hemodynamic parameters (HR, SBP, DBP, and MAP) were recorded at baseline, just before induction and at 1, 3, 5, 10, 15, and 30 min after intubation and every 15 min till the end of surgery. Results: After conducting this study, we observed that heart rates at 1, 3, 5, and 10 were significantly lower in the M group as compared to the C group (P&lt;0.05). Systolic, diastolic, and mean blood pressure were also reduced significantly in the M group as compared to the C group (P&lt;0.05). Conclusion: Magnesium sulfate when used at the dose of 40 mg/kg attenuates the hemodynamic stress response during laryngoscopy and nasotracheal intubation.

Domestication of farmed fish via the attenuation of stress responses mediated by the hypothalamus-pituitary-inter-renal endocrine axis.

Human-directed domestication of terrestrial animals traditionally requires thousands of years for breeding. The most prominent behavioral features of domesticated animals include reduced aggression and enhanced tameness relative to their wild forebears, and such behaviors improve the social tolerance of domestic animals toward both humans and crowds of their own species. These behavioral responses are primarily mediated by the hypothalamic–pituitary–adrenal (inter-renal in fish) (HPA/I) endocrine axis, which is involved in the rapid conversion of neuronal-derived perceptual information into hormonal signals. Over recent decades, growing evidence implicating the attenuation of the HPA/I axis during the domestication of animals have been identified through comprehensive genomic analyses of the paleogenomic datasets of wild progenitors and their domestic congeners. Compared with that of terrestrial animals, domestication of most farmed fish species remains at early stages. The present review focuses on the application of HPI signaling attenuation to accelerate the domestication and genetic breeding of farmed fish. We anticipate that deeper understanding of HPI signaling and its implementation in the domestication of farmed fish will benefit genetic breeding to meet the global demands of the aquaculture industry.

Comparision of intravenous magnesium sulphate and lignocaine in attenuation of pressor response to laryngoscopy and endotracheal intubation

Endotracheal intubation and laryngoscopy are noxious stimuli and provoke cardiovascular and autonomic responses because of sympathoadrenal stimulation. Attenuation of significant increases in heart rate and blood pressure decreases the risk of complications.Various pharmacological and non-pharmacological methods have been tried to attenuate hemodynamic response to laryngoscopy and endotracheal intubation. None of the approaches have proved to be ideal.In view of it present study was undertaken to evaluate and compare effects of intravenous magnesium sulphate 30mg/kg and lignocaine 2mg/kg in attenuation of pressor response to laryngoscopy and endotracheal intubation.Prospective randomized controlled study was conducted in which 60 American society of Anesthesiologist 1 patients, aged 18-60yrs, undergoing elective surgery under general anesthesia were selected. Patients were randomized into 2 groups: Group 1 with thirty patients who received MgSO4 30mg/kg and Group 2 with thirty patients who received lignocaine 2 mg/kg intravenous bolus. Anesthesia was induced using premedication glycopyrolate, midazolam, ondansetron injection Fentanyl was administered as analgesic agent. Study drug Injection mgso4 was administered 90sec before induction with injection propofol as induction agent followed by injection succinylscoline to facilitate intubation. Laryngoscopy and intubation response in both groups were studied by recording Heart Rate (HR), blood pressure (BP), at baseline,after administering drug, at laryngoscopy, after intubation, 1min,3min,5minsafter intubation.Study revealed that Group 1 patients had significant decreasing trend in HR and MAP recorded till 5mins after intubation. Mgso4 has vasodilator properties and significantly suppresses release of catecholamines and hence can attenuate stress response to laryngoscopy and endotracheal intubation better than lignocaine.

EFFECTS OF CAFFEINE ON BLOOD PRESSURE AND HEART RATE VARIABILITY AT REST AND DURING COLD PRESSOR TEST

Objective: Caffeine is the most widely consumed pharmacologically active substance in the world and is found in a variety of foods, and beverages. Even though the acute and long-term effects on the cardiovascular system are widely studied, the accumulated effects of caffeine and physiological stress are not clear. This study aimed to characterize the acute effects of caffeine on blood pressure (BP), heart rate (HR), and heart rate variability (HRV) at rest and during a cold pressor test (CPT) in healthy individuals. Design and method: Nineteen normotensive male participants (25 ± 2 years, BMI 24 ± 3) were enrolled in this double-blinded, placebo-controlled trial. Participants randomly received both a placebo (PL) and a caffeinated (3 mg/kg) drink (CAF) on two separate days. Before and following a 45-minute wash-in period BP, HR, and HRV were measured at supine rest and during a CPT. During the CPT, participants immersed their right hand into cold water (5C) for two minutes. Results: There were no significant differences in resting systolic (130 ± 13 mmHg vs. 125 ± 12 mmHg, p = .187), and diastolic (76 ± 7 mmHg vs. 73 ± 8 mmHg, p = .236) BP, as well as in HR (61 ± 10 bpm vs. 60 ± 8 bpm, p = .531), RMSSD (74 ± 36 ms vs. 83 ± 40 ms, p = .217), and Mean RR (1014 ± 155 ms vs. 1034 ± 140 ms, p = .570) between CAF and PL. The same was true for systolic (152 ± 14 mmHg vs. 151 ± 14 mmHg, p = .785) and diastolic (95 ± 11 mmHg vs. 96 ± 13 mmHg, p = .236) BP during CPT. However, CAF supplementation resulted in a significantly lower HR (62 ± 8 bpm vs. 73 ± 18 bpm, p = .013), and a significantly higher RMSSD (83 ± 51 ms vs. 55 ± 28 ms, p = .004), and Mean RR (1005 ± 158 ms vs. 867 ± 152 ms, p &lt; .001) during CPT compared to PL. Conclusions: The often reported acute increase in BP after caffeine supplementation could not be confirmed in this cohort of normotensive young adults. Caffeine supplementation neither increased nor blunted BP response during the CPT. However, HR was significantly lower, and parasympathetic HRV indices were significantly higher during the CPT after consuming CAF. Thus, caffeine seems to attenuate stress response with a shift in sympathovagal control toward enhanced parasympathetic activity.

Yolk corticosterone and progesterone levels in Greater Rhea (Rhea americana) eggs vary in a changing social environment.

Maternal hormones in avian egg yolks may signal and prepare offspring for the prevailing conditions. However, this adjustment requires some degree of flexibility in regulating yolk hormone deposition. The Greater Rhea (Rhea americana) has a particular mating system that combines mixed polygyny and polyandry, communal nesting, and exclusive paternal care of chicks. In this species, we previously found that yolk hormone deposition varies among eggs of different captive populations and could influence chicks' physiology and behavior. However, it is still unknown whether females can modify yolk hormone deposition in a changing social environment. Using a captive population of Greater Rheas, in this study, we quantified yolk hormone levels before and after a reduction in the number of females present in the population. We found that females deposited on average higher yolk corticosterone and lower yolk progesterone after the change in their social environment. Since corticosterone deposited into the yolk comes exclusively from the female's plasma, our results suggest that females had, on average, higher plasma corticosterone levels. The change in the number of females may increase the events of male-male competitions, courtships, and matings, leading to an increase of corticosterone in the females' plasma and then into their eggs. Since we previously found that higher yolk corticosterone and lower yolk progesterone were associated with the production of chicks that have an attenuated stress response, the present study results suggest that yolk hormone deposition is mediated by flexible mechanisms that could adjust development to the prevailing conditions.

Effects of intravenous dexmedetomidine on perioperative haemodynamics and quality of emergence in patients undergoing head and neck surgery following general anaesthesia—a comparative randomized, double-blind placebo-controlled study

BackgroundDexmedetomidine is a widely used alpha-2 adrenoreceptor agonist in perioperative patient care. Its postsynaptic activation of the receptors in the central nervous system is responsible for reduced neuronal firing with resultant sedation, anxiolysis, analgesia, hypotension and bradycardia leading to effective stress response attenuation seen during laryngoscopy and orotracheal intubation. Major head and neck surgeries demand nasotracheal intubation which is more stressful than orotracheal as it traverses through the nasopharynx which is very pain-sensitive. This is to protect the airway in the immediate postoperative period from oedema or haematoma in the oral cavity or neck. Though its stress response attenuation, haemodynamic stability during the intraoperative period following orotracheal intubation has been well studied, its role in the prevention of emergence delirium and tube tolerance following nasotracheal intubation in major head and neck surgery is not found in the literature. Our aim was to evaluate whether dexmedetomidine effectively attenuates the stress response following nasotracheal intubation, perioperative haemodynamic fluctuations and quality of emergence in patients undergoing head and neck oncosurgeries.MethodsA total of 150 patients were randomly assigned to one of the two groups; group D (dexmedetomidine group) and group S (control group with saline). Group D patients received a bolus dose of dexmedetomidine 1 μg/kg in 10 ml saline over 10 mts before induction of GA followed by an infusion at 0.4 μ/kg/h during surgery. Statistical analysis was done using SPSS version 11.0 (SPSS Ltd., Chicago, IL). Categorical data were represented using frequencies and percentages. Continuous variables were represented using mean and standard deviation. The association between categorical variables was assessed using the chi-square or Fisher’s exact test, and continuous variables following normality assumption with respect to the two groups were assessed using an independent sample t-test. P value < 0.05 was considered to be statistically significant.ResultsPatients in the D group showed statistically significant attenuation of heart rate (P < 0.05) and blood pressure (P < 0.05) throughout the surgical period compared to saline. Also, there was a significant reduction in blood loss (P = 0.042), cough score (P = 0.001) and sedation score (P = 0.001) in the D group.ConclusionsWe conclude that a bolus dose of dexmedetomidine 1 μg/kg given 10 min before induction of anaesthesia followed by an infusion at 0.4 μg/kg/h during surgery effectively attenuates the haemodynamic responses during nasotracheal intubation and provides smooth emergence as evidenced by reduced coughing, agitation and arousable sedation without respiratory depression which facilitates tube tolerance following major head and neck oncosurgeries. Blood loss was also found to be significantly reduced.