sai suraj - Academia.edu (original) (raw)

Papers by sai suraj

Research paper thumbnail of KEYWORDSLaryngoscopy, Intubation, Esmolol, Propofol

Research paper thumbnail of KEYWORDSClonidine, Dexmedetomidine, Ropivacaine, Supraclavicular Brachial Plexus Block

Research paper thumbnail of Role of timing of fentanyl administration in attenuating cardiovascular response to laryngoscopy and endotracheal intubation

MedPulse International Journal of Anesthesiology, 2019

We have previously reported that the activation of Toll-like receptor 4 (TLR4) by lipopolysacchar... more We have previously reported that the activation of Toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) induced rapid death of primary cultured rat microglia. However, a subpopulation of microglia survived much longer than two days, in which time all control cells had died. These surviving microglia may have neuroprotective functions because the neurons remained viable in co-cultures with these microglia. Moreover, the LPS-stimulated microglia may produce GM-CSF to promote survival. However, signaling mechanism of TLR4-mediated microglial long-term survival remains unknown. Therefore, in this study, we investigated TLR4 signaling pathways that control microglial survival, focusing on p38 MAP kinase and NF-κB, which are known to be important for innate immune response and control of apoptosis. Furthermore, we examined the involvement of GM-CSF receptor downstream signaling intermediates, JAK2 and STAT5, which are known to regulate the transcription of survival genes. LPS stimulation resulted in the phosphorylation of p38 MAP kinase, NF-κB and STAT5 in primary rat microglia. Moreover, a p38 MAP kinase inhibitor, SB202190, and a NF-κB inhibitor, BAY11-7082, suppressed LPS-stimulated microglial survival. Inhibition of JAK2 by NVP-BSK805 also inhibited the survival of these microglia. These results suggest that p38 and/or NF-κB pathways may play important roles in TLR4-mediated microglial survival. Furthermore, microglia-producing GM-CSF may activate cytoprotective JAK2/STAT5 signals to support their survival.

Research paper thumbnail of KEYWORDSPropofol-thiopentone, Propofol-ketamine, Haemodynamics

Research paper thumbnail of A Comparitive Evaluation of 0.75% Ropivacaine with Clonidine and 0.75% Ropivacaine with Dexmedetomidine in Supraclavicular Brachial Plexus Block- a Prospective Randomised Double-Blind Study

Journal of Evidence Based Medicine and Healthcare, 2018

BACKGROUND Brachial plexus blockade is considered as cornerstone of regional anaesthesia practice... more BACKGROUND Brachial plexus blockade is considered as cornerstone of regional anaesthesia practice. Ropivacaine is a new amide, long acting, pure S (-) enantiomer and local anaesthetic. This study was done to compare clonidine and dexmedetomidine as an adjuvant to 0.75% ropivacaine in supraclavicular brachial plexus block. MATERIALS AND METHODS A prospective randomised double-blind study was done in 80 patients of American Society of Anesthesiologist (ASA) grade I and II undergoing elective upper limb surgeries under supraclavicular block. Patients were randomised into 2 groups. Group 1 (n=40) received 30 mL of 0.75% ropivacaine with clonidine 1 mcg/kg and group 2 (n=40) received 30 mL of 0.75% ropivacaine with dexmedetomidine 1 mcg/kg. Onset and recovery time of sensory and motor block, duration of analgesia and quality of block, haemodynamic variables and level of sedation were studied in two groups. RESULTS Sensory and motor block onset times were shorter in group 2 (onset of sensory block was 4.9 ± 1.08 minutes and onset of motor block was 8.9 ± 1.41 minutes) than in group 1 (onset of sensory block was 10.7 ± 4.05 minutes and onset of motor block took 12.1 ± 4.11 minutes) (p value <0.0001). Sensory and motor block durations and duration of analgesia were longer in group 2 than in group 1 (p<0.0001). Blood pressure and heart rate were lower in group 2 as compared to group 1 (p value <0.0001). The number of patients achieving grade 4 quality of block was higher in group 2 as compared to group 1. CONCLUSION Dexmedetomidine (1 mcg/kg) hastens the onset of sensory and motor block, prolongs the duration of sensory and motor block, enhances the quality of block and sedation and also prolongs duration of analgesia as compared with clonidine (1 mcg/kg) when used as an adjuvant to 0.75% ropivacaine in supraclavicular block.

Research paper thumbnail of KEYWORDSLaryngoscopy, Intubation, Esmolol, Propofol

Research paper thumbnail of KEYWORDSClonidine, Dexmedetomidine, Ropivacaine, Supraclavicular Brachial Plexus Block

Research paper thumbnail of Role of timing of fentanyl administration in attenuating cardiovascular response to laryngoscopy and endotracheal intubation

MedPulse International Journal of Anesthesiology, 2019

We have previously reported that the activation of Toll-like receptor 4 (TLR4) by lipopolysacchar... more We have previously reported that the activation of Toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) induced rapid death of primary cultured rat microglia. However, a subpopulation of microglia survived much longer than two days, in which time all control cells had died. These surviving microglia may have neuroprotective functions because the neurons remained viable in co-cultures with these microglia. Moreover, the LPS-stimulated microglia may produce GM-CSF to promote survival. However, signaling mechanism of TLR4-mediated microglial long-term survival remains unknown. Therefore, in this study, we investigated TLR4 signaling pathways that control microglial survival, focusing on p38 MAP kinase and NF-κB, which are known to be important for innate immune response and control of apoptosis. Furthermore, we examined the involvement of GM-CSF receptor downstream signaling intermediates, JAK2 and STAT5, which are known to regulate the transcription of survival genes. LPS stimulation resulted in the phosphorylation of p38 MAP kinase, NF-κB and STAT5 in primary rat microglia. Moreover, a p38 MAP kinase inhibitor, SB202190, and a NF-κB inhibitor, BAY11-7082, suppressed LPS-stimulated microglial survival. Inhibition of JAK2 by NVP-BSK805 also inhibited the survival of these microglia. These results suggest that p38 and/or NF-κB pathways may play important roles in TLR4-mediated microglial survival. Furthermore, microglia-producing GM-CSF may activate cytoprotective JAK2/STAT5 signals to support their survival.

Research paper thumbnail of KEYWORDSPropofol-thiopentone, Propofol-ketamine, Haemodynamics

Research paper thumbnail of A Comparitive Evaluation of 0.75% Ropivacaine with Clonidine and 0.75% Ropivacaine with Dexmedetomidine in Supraclavicular Brachial Plexus Block- a Prospective Randomised Double-Blind Study

Journal of Evidence Based Medicine and Healthcare, 2018

BACKGROUND Brachial plexus blockade is considered as cornerstone of regional anaesthesia practice... more BACKGROUND Brachial plexus blockade is considered as cornerstone of regional anaesthesia practice. Ropivacaine is a new amide, long acting, pure S (-) enantiomer and local anaesthetic. This study was done to compare clonidine and dexmedetomidine as an adjuvant to 0.75% ropivacaine in supraclavicular brachial plexus block. MATERIALS AND METHODS A prospective randomised double-blind study was done in 80 patients of American Society of Anesthesiologist (ASA) grade I and II undergoing elective upper limb surgeries under supraclavicular block. Patients were randomised into 2 groups. Group 1 (n=40) received 30 mL of 0.75% ropivacaine with clonidine 1 mcg/kg and group 2 (n=40) received 30 mL of 0.75% ropivacaine with dexmedetomidine 1 mcg/kg. Onset and recovery time of sensory and motor block, duration of analgesia and quality of block, haemodynamic variables and level of sedation were studied in two groups. RESULTS Sensory and motor block onset times were shorter in group 2 (onset of sensory block was 4.9 ± 1.08 minutes and onset of motor block was 8.9 ± 1.41 minutes) than in group 1 (onset of sensory block was 10.7 ± 4.05 minutes and onset of motor block took 12.1 ± 4.11 minutes) (p value <0.0001). Sensory and motor block durations and duration of analgesia were longer in group 2 than in group 1 (p<0.0001). Blood pressure and heart rate were lower in group 2 as compared to group 1 (p value <0.0001). The number of patients achieving grade 4 quality of block was higher in group 2 as compared to group 1. CONCLUSION Dexmedetomidine (1 mcg/kg) hastens the onset of sensory and motor block, prolongs the duration of sensory and motor block, enhances the quality of block and sedation and also prolongs duration of analgesia as compared with clonidine (1 mcg/kg) when used as an adjuvant to 0.75% ropivacaine in supraclavicular block.