ABSTRACT
OBJECTIVE To reveal the role of the basal forebrain(BF)GABAergic neurons in the regulation of isoflurane anesthesia and to elucidate the underlying neural pathways.METHODS The activity of BF GABAer-gic neurons was monitored during isoflurane anesthesia using a genetically encoded calcium indicator in Vgat-Cre mice of both sexes.The activity of BF GABAer-gic neurons was manipulated by chemogenetic and opto-genetic approaches.Sensitivity,induction time and emer-gence time of isoflurane anesthesia were estimated by righting reflex.The electroencephalogram(EEG)power and burst-suppression were monitored by EEG recording.The effects of activation of GABAergic BF-thalamic reticu-lar nucleus(TRN)pathway on isoflurane anesthesia were investigated with optogenetics.RESULTS The activity of BF GABAergic neurons was generally inhibited during isoflurane anesthesia,obviously decreased during the induction of anesthesia and gradually restored during the emergence from anesthesia.Activation of BF GABAergic neurons with chemogenetics and optogenetics promoted behavioral emergence from isoflurane anesthesia,with decreased sensitivity to isoflurane,delayed induction and accelerated emergence from isoflurane anesthesia.Optogenetic activation of BF GABAergic neurons prom-oted cortical activity during isoflurane anesthesia,with decreased EEG delta power and burst suppression ratio during 0.8%and 1.4%isoflurane anesthesia,respectively.Similar to the effects of activating BF GABAergic cell bod-ies,photostimulation of BF GABAergic terminals in the TRN also strongly promoted cortical activation and behav-ioral emergence from isoflurane anesthesia.CONCLU-SION The GABAergic neurons in the BF is a key neural substrate for general anesthesia regulation that facilitates behavioral and cortical emergence from general anesthe-sia via the BF-TRN pathway.
ABSTRACT
Objective To evaluate the efficacy of an airway topical anesthesia catheter for topical anesthesia using a spray-as-you-go technique via the fiberoptic bronchoscope (FOB).Methods Forty American Society of Anesthesiologists physical status Ⅰ-Ⅲ patients with obstructive sleep apnea syndrome,aged 20-64 yr,with body mass index of 23-35 kg/m2,with no upper respiratory tract infection within 1 week before operation,scheduled for elective uvulopalatopharyngoplasty,were divided into 2 groups (n =20 each) using a random number table:routine control group (group C) and FOB-airway topical anesthesia catheter group (group F).In group C,the pharynx and larynx were sprayed with lidocaine FOB by using a laryngo-tracheal mucosal atomization device,and cricothyroid membrane puncture was performed and then lidocaine was injected.In group F,airway topical anesthesia was performed using a spray-as-you-go technique via the FOB with an airway topical anesthesia catheter spraying lidocaine via the nose.At 5 min after topical anesthesia of the airway,FOB-guided intubation was performed,and dexmedetomidine was intravenously infused at 0.1 μg · kg-1 · min-1 for sedation in both groups.Ramsay sedation scores were assessed after topical anesthesia and before intubation.The scores for the intubating condition and tolerance of tracheal tube were assessed during FOB-guided intubation.Successful intubation and the development of responses to intubation and hypoxemia were recorded.The patients were followed up one day after the end of operation,and parents' satisfaction with the procedure of intubation was recorded.Results Compared with group C,the intubating condition score,tolerance of tracheal tube score,success rate of intubation at first attempt and rate of parents' satisfaction with the procedure of intubation were significantly increased,and the incidence of responses to intubation was decreased (P＜0.05),and no significant change was found in Ramsay sedation scores before intubation and incidence of hyoxemia in group F (P＞0.05).Conclusion When the FOB is used to guide awake nasotracheal intubation,the airway topical anesthesia catheter provides better efficacy,better intubating conditions,and fewer side effects when applied for topical anesthesia using a spray-as-you-go technique via the FOB,it can be easily accepted by the patients and the efficacy is better that of routine airway topical anesthesia.
ABSTRACT
Objective To evaluate the efficacy of T-joint endoscopy mask for fiberoptic bronchoscopy (FOB)-guided awake nasotracheal intubation in patients with cervical spinal cord injury.Methods Forty patients of both sexes aged 21-64 yr with fracture of cervical spine complicated by spinal cord injury scheduled for anterior decompression and interbody fusion under general anesthesia were randomly divided into 2 groups according to the technique for awake nasotracheal intubation (n =20 each):group nasal catheter and group T-joint endoscopy mask.Topical anesthesia of nasal cavity,pharynx,larynx and trachea with 2％ lidocaine was conducted and then remifentanil was continuously infused at 0.05-0.15 μg· kg-1 · min-1 in both groups.The incidence of hypoxemia and intubation time were recorded.Arterial blood samples were obtained for determination of PaO2 and PaCO2 before topical anesthesia (baseline),immediately before and 1 min after placement of FOB and immediately after nasotracheal intubation was accomplished.Results The incidence of hypoxemia was significantly lower in group Tjoint endoscopy mask (0) than in group nasal catheter (25％) (P ＜ 0.05).The PaO2 during nasotracheal intubation was significantly higher in group T-joint endoscopy mask than in group nasal catheter (P ＜ 0.05).There was no significant difference in PaCO2 and intubation time between the 2 groups (P ＞ 0.05).Conclusion T-joint endoscopy mask facilitates awake nasotracheal intubation without affecting oxygen inhalation in patients with cervical spinal cord injuries.
ABSTRACT
Objective To construct F344 rat bone marrow mesenchymal stem cell line (MSC) modified with human hepatocyte growth factor (hHGF) gene.Methods Recombinant virus containing hHGF was obtained by transfecting the packaging cell line 293 FT with lentiviral vector pLV/EF1α-hHGF-IRES-eGFP.MSCs derived from F344 rat bone marrow were then tranfected with packed lentiviral vector.Purified MSCs expressing hHGF was obtained by screening culture with G418.MSCs and MSCs transfected with empty vector were used as control.The expression of hHGF protein was detected by Western blot (eGFP-MSCs).The hHGF-transfected MSCs were cultured in osteoblast-inducing culture medium and osteoblast phenotype was assayed by alizarin Red staining.The cells were also cultured in adipogenesis medium and stained with Oil Red O for identification.Results The expression of hHGF protein was significantly up-regulated in the hHGF-MSCs as compared with MSCs and eGFP-MSCs.hHGF-MSCs readily differentiated into mineralizing cells or adipocytes when incubated in differentiation medium.Conclusion A F344 rat MSC line that stably expresses HGF is successfully established.
ABSTRACT
Objective To investigate the effect of human hepatocyte growth factor (hHGF) genetic modification on the ameliorating effects of mesenchymal stem cells (MSCs) implantation on pulmonary microvascular rarefaction in a rat model of pulmonary hypertension (PH).Methods MSCs were obtained from F344 rats and transduced with lentiviral vector modified with human HGF (hHGF-MSCs) or empty vector (EGFP-MSCs).Sixty-six 7 week old male F344 rats weighing 180-250 g were used in this study.PH was induced by left pneumonectomy and subcutaneous monocrotaline (MCT) 60 mg/kg injected at 2 weeks after operation.The animals with PH were randomly divided into 3 groups:control group (group C),EGFP-MSCs group (group E) and HGF-MSCs group (group H).Groups H and E received hHGF-MSCs or EGFP-MSCs 5 × 105 in DMEM 1 ml iv at 3 weeks after subcutaneous MCT injection,while group C received plain DMEM 1 ml.Mean pulmonary arterial pressure (mPAP) was measured and right ventricular hypertrophy and angiogenesis in the lung were assessed and the content of rat HGF (rHGF) and hHGF protein in lung tissue and pulmonary capillary density (by immuno-histochemistry) was measured at 2 weeks after MSCs implantation.The survival rates within 45 days after MCT administration were compared among the 3 groups.Results No hHGF was detected in groups C and E.Both hHGF-MSCs and EGFP-MSCs significantly reduced MPAP and right ventricular hypertrophy and increased pulmonary capillary density and survival rates in groups H and E as compared with group C and the efficacy of hHGF-MSCs was significantly greater than that of EGFP-MSCs.Barium angiography revealed that distal pulmonary vasculature was significantly increased in group H as compared with groups E and C.The survival of the rats receiving hHGF-MSCs was significantly longer in group H than that in groups E and C.Conclusion hHGF genetic modification can improve the ameliorating effects of MSCs implantation on PH-related microvascular rarefaction.
ABSTRACT
Objective To investigate the effect of transplantation of bone marrow mesenchymal stem cells (MSCs) genetically modified with human hepatocyte growth factor gene (hHGF) on angiogenesis in the rat lung.Methods Twenty F344 rats,aged 2 months,weighing 200-250 g,were randomly divided into 2 groups ( n =10 each):HGF group and control group (group C).MSCs genetically modified with hHGF was injected through the external jugular vein in group HGF.While the equal volume of DMEM culture medium (1 ml) was given instead in group C.The mean pulmonary artery pressure was detected at 28 days after transplantation.Then the rats were sacrificed and the lungs were removed for determination of the content of hHGF,expression of proliferating cell nuclear antigen (to reflect the degree of endothelial cell proliferation showed by the small pulmonary vessels) and Ⅷ factor (to reflect the density of the small pulmonary vessels),and microscopic examination.Results Compared with group C,no significant change was found in mean pulmonary artery pressure ( P ＞ 0.05),while the content of hHGF,degree of endothelial cell proliferation,and density of the small pulmonary vessels were significantly increased in group HGF ( P ＜ 0.01).No change was found in the structure of the small pulmonary vessels in group HGF.Conclusion Transplantation of MSCs genetically modified with hHGF can promote angiogenesis in the rat lung.
ABSTRACT
Objective To investgate the changes in the expression of hepatocyte growth factor (HGF)and c-met in the lungs in a rat model of pulmonary hypertension.Methods Eighty 7 week old male SD rats weighing 180-250 g were randomly divided into 2 groups ( n =40 each ):control group (group C) and pulmonary hypertension group (group PH).Pulmonary hypertension was induced by left pneumonectomy and subcutaneous monocrotaline (MCT) 60 mg/kg 2 weeks later.Pulmonary artery pressure and the ratio between the weight of right ventricle and left ventricle + interventricular septum ( RV/LV + S) were measured at 7,14,21 and 28 d after MCT administration.HGF and c-met protein and mRNA expression and TGF-β content in the lung tissue were determined.Results Pulmonary hypertension and right ventricular hypertrophy associated with hypertrophy of pulmonary artery tunica media and muscularization of small pulmonary arteries developed after MCT administration in PH group.In PH group HGF protein and mRNA expression in the lungs was significantly down-regulated as compared with group C.There were no significant differences in c-met protein and mRNA expression in the lungs between the 2 groups.The TGF-β content in the lungs was significantly increased in group PH as compared with group C.Conclusion Decrease in HGF production in the lungs plays an important role in the pulmonary hypertension.Increasing of pulmonary TGF-β may play an important role in the down-regulation of pulmonary HGF expression during pulmonary hypertension.