The use of narrow band imaging (NBI) during flexible endoscopic evaluation of swallowing (FEES) is recognised as an emerging technology to improve the contrast of the test fluid during endoscopic dysphagia evaluation. This study tested the hypothesis that the use of NBI in FEES would improve the detection of laryngeal penetration and aspiration in patients with unilateral vocal fold paralysis/paresis (UVFP), a typically difficult population in which to detect the presence of aspiration with FEES. Twenty-one consecutive outpatients with UVFP were evaluated with FEES using white light (WL) and NBI under 150 test conditions (75 WL & 75 NBI). Three speech pathologists, highly experienced in FEES using WL but novices to using NBI, rated laryngeal penetration and aspiration for green dyed thin fluid (5 ml and 90 ml) and mildly thick fluid (5 ml) milk, and were compared to two raters more experienced in using NBI during FEES. Laryngeal penetration and aspiration were significantly higher for larger volumes (90 ml) (p less then 0.05). With NBI-naïve raters, there was a trend towards lower intra-rater and inter-rater reliability compared to WL on all bolus trials reaching significance on mildly thick fluid (p less then 0.01). There was lower rater confidence when using NBI compared to WL in NBI-naïve raters to detect aspiration (p less then 0.01). Sensitivity was lower regardless of NBI experience; 80.77-84.21% with WL compared to 46.15-50.00% with NBI. Findings indicate that the improved contrast of a dyed opaque milk trial under WL may negate the potential benefits of using NBI to increase the contrast of the test fluid and supports the use of an opaque test fluid such as milk. NBI may also not be as useful to clinicians with no experience with the altered light condition, and can result in lower sensitivity in even the experienced user.
Expression of Mc4r in peripheral organs indicates it has broader roles in organ homeostasis and regeneration. However, the expression and function of Mc4r in the mouse limb and digit has not been fully investigated. Our previous work showed that Mc4r-/- **** fail to regenerate the digit, but whether activation of MC4R signaling could rescue digit regeneration, or stimulate proximal digit regeneration is not clear.
We analyzed the expression dynamics of Mc4r in the embryonic and postnatal mouse limb and digit using the Mc4r-gfp ****. https://www.selleckchem.com/products/Pomalidomide(CC-4047).html We found that Mc4r-GFP is mainly expressed in the limb nerves, and in the limb muscles that are undergoing secondary myogenesis. Expression of Mc4r-GFP in the adult mouse digit is restricted to the nail matrix. We also examined the effect of α-MSH on mouse digit regeneration. We found that administration of α-MSH in the Mc4r+/- **** rescue the delayed regeneration of distal digit tip. α-MSH could rescue distal digit regeneration in denervated hindlimbs. In addition, α-MSH could stimulate regeneration of the proximally amputated digit, which is non-regenerative.
Mc4r expression in the mouse limb and digit is closely related to nerve tissues, and α-MSH/MC4R signaling has a neurotrophic role in mouse digit tip regeneration.
Mc4r expression in the mouse limb and digit is closely related to nerve tissues, and α-MSH/MC4R signaling has a neurotrophic role in mouse digit tip regeneration.Cyclooxygenase (COX) plays a critical role in synaptic plasticity. Therefore, long-term administration of acetylsalicylic acid (ASA) and its main metabolite, salicylate, as a COX inhibitor may impair synaptic plasticity and subsequently memory formation. Although different studies have tried to explain the effects of ASA and sodium salicylate (SS) on learning and memory, the results are contradictory and the mechanisms are not exactly known. The present study was designed to investigate the effects of long-term low-dose (equivalent to prophylactic dose) and short-term high-dose (equivalent to analgesic dose) administration of ASA and SS respectively, on spatial learning and memory and hippocampal synaptic plasticity. Animals were treated with a low dose of ASA (2 mg/ml solvated in drinking water, 6 weeks) or a high dose of SS, a metabolite of ASA, (300 mg/kg, 3 days, twice-daily, i.p). Spatial memory and synaptic plasticity were assessed by water maze performance and in vivo field potential recording from CA1, respectively. Animals treated with ASA but not SS showed a significant increase in escape latency and distance moved. Furthermore, in the probe test, animals treated with both drugs spent less time in the target quadrant zone. The paired-pulse ratio (PPR) at 20-ms inter-pulse intervals (IPI) as an index of short-term plasticity in both treated groups was significantly higher than of the control group. Interestingly, none of the administered drugs affected long-term potentiation (LTP). These data suggested that long-term inhibition of COX disrupted memory acquisition and retrieval. Interestingly, cognitive impairments happened along with short-term but not long-term synaptic plasticity disturbance.The generation of a reactive nitrenium ion by microsomal/mitochondrial cytochrome P450 (CYPs) from clozapine (CLZ) has been suggested as the main cause of cardiotoxicity by this drug. Previous studies indicated that thymoquinone (TQ) as an active constituent of Nigella sativa has pharmacological effects such as antioxidant, reactive oxygen species (ROS) scavenger, and inhibitory effect on CYPs enzymes. Therefore, we hypothesized that TQ with these pharmacological effects can reduce CLZ-induced toxicity in isolated cardiomyocytes and mitochondria. Rat left ventricular cardiomyocytes and mitochondria were isolated by collagenase perfusion and differential centrifugation respectively. Then, isolated cardiomyocytes and mitochondria were pretreated with different concentrations of TQ (1, 5, and 10 μmol/l) for 30 min and then followed by exposure to CLZ (50 μmol/l) for 6 h. After 6 h of incubation, using biochemical evaluations and flow cytometric analysis, the parameters of cellular toxicity including cytotoxicity, the level of oxidized/reduced glutathione (GSH/GSSG), malondialdehyde (MDA), reactive oxygen species (ROS) formation, lysosomal membrane integrity, mitochondria membrane potential (ΔΨm) collapse, and mitochondrial toxicity including succinate dehydrogenase (SDH) activity and mitochondrial swelling were analyzed. We observed a significant toxicity in isolated cardiomyocytes and mitochondria after exposure with CLZ which was related to ROS formation, oxidative stress, GSH depletion, lysosomal and mitochondrial damages, and mitochondrial dysfunction and swelling, while TQ pretreatment reverted the above toxic effect of CLZ on isolated cardiomyocytes and mitochondria. Our results indicate that TQ prevents and reverses CLZ-induced cytotoxicity and mitochondrial damages in isolated cardiomyocytes and mitochondria, providing an experimental basis for clinical treatment on CLZ-induced cardiotoxicity.
The use of narrow band imaging (NBI) during flexible endoscopic evaluation of swallowing (FEES) is recognised as an emerging technology to improve the contrast of the test fluid during endoscopic dysphagia evaluation. This study tested the hypothesis that the use of NBI in FEES would improve the detection of laryngeal penetration and aspiration in patients with unilateral vocal fold paralysis/paresis (UVFP), a typically difficult population in which to detect the presence of aspiration with FEES. Twenty-one consecutive outpatients with UVFP were evaluated with FEES using white light (WL) and NBI under 150 test conditions (75 WL & 75 NBI). Three speech pathologists, highly experienced in FEES using WL but novices to using NBI, rated laryngeal penetration and aspiration for green dyed thin fluid (5 ml and 90 ml) and mildly thick fluid (5 ml) milk, and were compared to two raters more experienced in using NBI during FEES. Laryngeal penetration and aspiration were significantly higher for larger volumes (90 ml) (p less then 0.05). With NBI-naïve raters, there was a trend towards lower intra-rater and inter-rater reliability compared to WL on all bolus trials reaching significance on mildly thick fluid (p less then 0.01). There was lower rater confidence when using NBI compared to WL in NBI-naïve raters to detect aspiration (p less then 0.01). Sensitivity was lower regardless of NBI experience; 80.77-84.21% with WL compared to 46.15-50.00% with NBI. Findings indicate that the improved contrast of a dyed opaque milk trial under WL may negate the potential benefits of using NBI to increase the contrast of the test fluid and supports the use of an opaque test fluid such as milk. NBI may also not be as useful to clinicians with no experience with the altered light condition, and can result in lower sensitivity in even the experienced user.
Expression of Mc4r in peripheral organs indicates it has broader roles in organ homeostasis and regeneration. However, the expression and function of Mc4r in the mouse limb and digit has not been fully investigated. Our previous work showed that Mc4r-/- mice fail to regenerate the digit, but whether activation of MC4R signaling could rescue digit regeneration, or stimulate proximal digit regeneration is not clear.
We analyzed the expression dynamics of Mc4r in the embryonic and postnatal mouse limb and digit using the Mc4r-gfp mice. https://www.selleckchem.com/products/Pomalidomide(CC-4047).html We found that Mc4r-GFP is mainly expressed in the limb nerves, and in the limb muscles that are undergoing secondary myogenesis. Expression of Mc4r-GFP in the adult mouse digit is restricted to the nail matrix. We also examined the effect of α-MSH on mouse digit regeneration. We found that administration of α-MSH in the Mc4r+/- mice rescue the delayed regeneration of distal digit tip. α-MSH could rescue distal digit regeneration in denervated hindlimbs. In addition, α-MSH could stimulate regeneration of the proximally amputated digit, which is non-regenerative.
Mc4r expression in the mouse limb and digit is closely related to nerve tissues, and α-MSH/MC4R signaling has a neurotrophic role in mouse digit tip regeneration.
Mc4r expression in the mouse limb and digit is closely related to nerve tissues, and α-MSH/MC4R signaling has a neurotrophic role in mouse digit tip regeneration.Cyclooxygenase (COX) plays a critical role in synaptic plasticity. Therefore, long-term administration of acetylsalicylic acid (ASA) and its main metabolite, salicylate, as a COX inhibitor may impair synaptic plasticity and subsequently memory formation. Although different studies have tried to explain the effects of ASA and sodium salicylate (SS) on learning and memory, the results are contradictory and the mechanisms are not exactly known. The present study was designed to investigate the effects of long-term low-dose (equivalent to prophylactic dose) and short-term high-dose (equivalent to analgesic dose) administration of ASA and SS respectively, on spatial learning and memory and hippocampal synaptic plasticity. Animals were treated with a low dose of ASA (2 mg/ml solvated in drinking water, 6 weeks) or a high dose of SS, a metabolite of ASA, (300 mg/kg, 3 days, twice-daily, i.p). Spatial memory and synaptic plasticity were assessed by water maze performance and in vivo field potential recording from CA1, respectively. Animals treated with ASA but not SS showed a significant increase in escape latency and distance moved. Furthermore, in the probe test, animals treated with both drugs spent less time in the target quadrant zone. The paired-pulse ratio (PPR) at 20-ms inter-pulse intervals (IPI) as an index of short-term plasticity in both treated groups was significantly higher than of the control group. Interestingly, none of the administered drugs affected long-term potentiation (LTP). These data suggested that long-term inhibition of COX disrupted memory acquisition and retrieval. Interestingly, cognitive impairments happened along with short-term but not long-term synaptic plasticity disturbance.The generation of a reactive nitrenium ion by microsomal/mitochondrial cytochrome P450 (CYPs) from clozapine (CLZ) has been suggested as the main cause of cardiotoxicity by this drug. Previous studies indicated that thymoquinone (TQ) as an active constituent of Nigella sativa has pharmacological effects such as antioxidant, reactive oxygen species (ROS) scavenger, and inhibitory effect on CYPs enzymes. Therefore, we hypothesized that TQ with these pharmacological effects can reduce CLZ-induced toxicity in isolated cardiomyocytes and mitochondria. Rat left ventricular cardiomyocytes and mitochondria were isolated by collagenase perfusion and differential centrifugation respectively. Then, isolated cardiomyocytes and mitochondria were pretreated with different concentrations of TQ (1, 5, and 10 μmol/l) for 30 min and then followed by exposure to CLZ (50 μmol/l) for 6 h. After 6 h of incubation, using biochemical evaluations and flow cytometric analysis, the parameters of cellular toxicity including cytotoxicity, the level of oxidized/reduced glutathione (GSH/GSSG), malondialdehyde (MDA), reactive oxygen species (ROS) formation, lysosomal membrane integrity, mitochondria membrane potential (ΔΨm) collapse, and mitochondrial toxicity including succinate dehydrogenase (SDH) activity and mitochondrial swelling were analyzed. We observed a significant toxicity in isolated cardiomyocytes and mitochondria after exposure with CLZ which was related to ROS formation, oxidative stress, GSH depletion, lysosomal and mitochondrial damages, and mitochondrial dysfunction and swelling, while TQ pretreatment reverted the above toxic effect of CLZ on isolated cardiomyocytes and mitochondria. Our results indicate that TQ prevents and reverses CLZ-induced cytotoxicity and mitochondrial damages in isolated cardiomyocytes and mitochondria, providing an experimental basis for clinical treatment on CLZ-induced cardiotoxicity.
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