二氧化碳对小鼠神经母细胞瘤细胞跨间皮细胞迁移影响的实验研究

目的 本实验研究不同气体条件对神经母细胞瘤细胞跨间皮细胞迁移的影响,探讨CO2气腹对腹腔肿瘤细胞迁移影响的潜在机制.方法 经0.125%胰酶预处理后,通过腹腔灌洗分离培养C57/BL6小鼠腹膜间皮细胞.间皮细胞纯化通过细胞形态学及免疫组化方法(小鼠间皮细胞角蛋白特异性抗体AE1/AE3)鉴定.MTT实验确定细胞活力.使用Transwell系统培养连续间皮细胞层,分别暴露于100%CO2及5%CO2 2 h,经荧光染色后的小鼠神经母细胞瘤细胞(Neuro2a)加入至Transwell系统上室,细胞迁移数目经多功能检测仪进行测定.结果 MTT实验提示,间皮细胞于5%CO2及100%CO2暴露后4 h、6 h、10 h及24 h后两组细胞活力分别为0.82±0.28比0.62±0.22、0.87士0.24比0.62±0.28、0.88±0.69比0.69±0.81及1.05±0.86比0.97±0.25,差别无统计学意义.迁移实验表明,间皮细胞于100%CO2中暴露后,细胞屏障功能下降,Neuro2a迁移数目增加258.56±71.08比77.05±27.89(P＜0.05).结论 100%CO2利于神经母细胞瘤细胞跨间皮细胞迁移.因此,小鼠模型中发现的CO2气腹后神经母细胞瘤转移增加可能与间皮细胞屏障削弱有关.

Abstract：

Objective This study was to assess the effect of CO2 pneumoperitoneum on transepithelial neuroblastoma cell migration. Methods Purification of primary murine peritoneal mesothelial cells was achieved by sequential, peritoneal lavage after 0. 125% trypsin pretreatment. Purity of the mesothelial cell culture was confirmed by cell morphology and immunohistochemical staining for specific cytokeratine (AE1/AE3). In all experiments vitality of the cells was confirmed by MTT assay. Monolayers of mesothelial cells were established on transwell systems. Following incubation with 100% CO2 or 5% CO2 for 2 h, fluorescent stained Neuro2a (neuroblastoma) cells were added to the upper chamber and their migration to the lower chamber was measured by multi - detection reader. Results The conversion of MTT was nearly same 4h, 6 h, 10 h and 24 h after 5% CO2 or 100% CO2 exposition,0. 82 ± 0. 28 VS 0. 62 ± 0. 22,0. 87 ± 0. 24 VS 0. 62 ± 0. 28, 0. 88 ± 0. 69 VS 0. 69 ± 0. 81 and 1. 05 ± 0. 86 VS 0. 97 ± 0. 25 respectively. Migration studies showed that the barrier function of the mesothelial monolayer decreased. A significantly increased migration of neuroblastoma cells was found after 100% CO2 exposure 258. 56 ± 71. 08 VS 77. 05 ± 27. 89 (P＜0. 05). Conclusions 100% CO2 facilitated transepithelial neuroblastoma cell migration. Thus, the increased neuroblastoma metastasis observed after CO2 pneumoperitoneum in mice might be related to an impaired mesothelial barrier function.     

二氧化碳对小鼠神经母细胞瘤细胞跨间皮细胞迁移影响的实验研究

Objective This study was to assess the effect of CO2 pneumoperitoneum on transepithelial neuroblastoma cell migration. Methods Purification of primary murine peritoneal mesothelial cells was achieved by sequential, peritoneal lavage after 0. 125% trypsin pretreatment. Purity of the mesothelial cell culture was confirmed by cell morphology and immunohistochemical staining for specific cytokeratine (AE1/AE3). In all experiments vitality of the cells was confirmed by MTT assay. Monolayers of mesothelial cells were established on transwell systems. Following incubation with 100% CO2 or 5% CO2 for 2 h, fluorescent stained Neuro2a (neuroblastoma) cells were added to the upper chamber and their migration to the lower chamber was measured by multi - detection reader. Results The conversion of MTT was nearly same 4h, 6 h, 10 h and 24 h after 5% CO2 or 100% CO2 exposition,0. 82 ± 0. 28 VS 0. 62 ± 0. 22,0. 87 ± 0. 24 VS 0. 62 ± 0. 28, 0. 88 ± 0. 69 VS 0. 69 ± 0. 81 and 1. 05 ± 0. 86 VS 0. 97 ± 0. 25 respectively. Migration studies showed that the barrier function of the mesothelial monolayer decreased. A significantly increased migration of neuroblastoma cells was found after 100% CO2 exposure 258. 56 ± 71. 08 VS 77. 05 ± 27. 89 (P＜0. 05). Conclusions 100% CO2 facilitated transepithelial neuroblastoma cell migration. Thus, the increased neuroblastoma metastasis observed after CO2 pneumoperitoneum in mice might be related to an impaired mesothelial barrier function.     

氧化亚氮气腹对新生猪循环、呼吸功能影响的实验研究

目的 建立新生猪气腹模型,观察人工N2O气腹时新生猪血流动力学及呼吸指标的变化规律.方法 乳猪14头,年龄7～14 d,体重2～4 kg.分为2组,对照组(CON组)7头,N2O气腹组(N2O组)7头,监测时间点为麻醉稳定后气腹开始前5 min,气腹开始后15 min、30 min、60min、120min,放气后60min.监测指标为:心率(HR)、每搏输出量指数(SVI)、心输出量指数(CI)、平均动脉压(MAP)、中心静脉压(CVP)、平均肺动脉压(MPAP)、系统血管阻力指数(SVRI)、左室内压变化速率(dP/dtmax)、动脉血二氧化碳分压(PaCO2)、动脉血氧分压(PaO2)、动脉血氧饱和度(SaO2)、血碳酸氢根离子浓度(HCO3-)及血酸碱度(pH).结果 CON组血流动力学及呼吸参数基本维持恒定.与CON组对比,N2O组MPAP(26.29±2.57)及SVRI(2923.00±115.70)增加,差异有统计学意义(P＜0.05);HR(113.57±3.23)、dP/dtmax(432.43±36.61)、MAP(75.00±4.27)、SVI(15.00±0.76)及CI(1.98±0.11)下降,差异有统计学意义(P＜0.05);PaCO2(41.00±2.20)及PaO2(172.14±1.57)升高,差异有统计学意义(P＜0.05).结论 2hN2O气腹对健康新生猪循环功能产生一定影响.

Abstract：

Objective To study the influence of nitric oxide (N2O) pneumoperitoneum on the circulatory and respiratory systems of piglets.Methods Fourteen piglets,which weighted 2-4 kilograms and aged 7-14 days old,were equally and randomly divided into control group and N2O pneumoperitoneum group.On the anesthetized piglets of the N2O group,N2O pneumoperitoneum was induced by inflate the peritoneal cavity with N2O.Monitoring parameters included heart rate (HR),stroke volume index (SVI),cardiac index (CI),mean arterial pressure (MAP),central venous pressure (CVP),mean pulmonary arterial pressure (MPAP),systemic vascular resistance index (SVRI),dP/dtmax,partial pressure of carbon dioxide in arterial blood (PaCO2),partial pressure of oxygen in arterial blood (PaO2),arterial oxygen saturation (SaO2),concentration of HCO3- (HCO3-) in arterial blood and blood pH value (pH).The monitoring parameters were collected 5 minutes before N2O pneumoperitoneum inflation,15,30,60,and 120 min after N2 O pneumoperitoneum inflation and 60 min after pneumoperitoneum deflation.Results Hemodynamic and respiratory parameters of the control piglets were constantly normal.Compared with the control piglets,MPAP (26.29±2.57),PaCO2 (41.00±2.20),PaO2 (172.14± 1.57) and SVRI (2923.00 ± 115.70) of the N2O pneumoperitoneum piglets increased (P＜0.05).HR (113.57 ± 3.23),dP/dtmax (432.43±36.61),MAP (75.00 ± 4.27),SVI ( 15.00±0.76) and CI (1.98±0.11) of N2O pneumoperitoneum piglets decreased (P＜0.05).Conclusions Two hours' N2O pneumoperitoneum changes some circulatory parameters of piglets.     

长时间人工气腹对心功能不全新生猪循环功能影响的实验研究

目的 建立新生猪气腹及心功能不全模型,观察长时间CO2及N2O气腹时心功能不全新生猪血流动力学指标的变化规律,比较膨腹气体对有合并症的新生机体进行长时间充填时的优劣.方法 乳猪14头,年龄7～14 d,体重2～4 kg.分为2组,心功能不全CO2气腹组(CO2-HF)7头,心功能不全N2O气腹组(N2O-HF)7头.CO2-HF及N2O-HF组进行4 h气腹,监测时间点为麻醉稳定后气腹开始前5 min,气腹开始后15、60、120、180、240 min,放气后30min.监测指标为:心率(HR)、每搏输出量指数(SVI)、心输出量指数(CI)、平均动脉压(MAP)、中心静脉压(CVP)、平均肺动脉压(MPAP)、系统血管阻力指数(SVRI)、左室内压变化速率(dP/dtmax).结果 与成模前相比,两组成模时HR、SVI及CI降低,差异有统计学意义(P＜0.05);MPAP升高及SVRI增加,差异有统计学意义(P＜0.05);dP/dtmax、MAP及CVP无明显改变.随后两组HR无明显改变,两组CI继续下降,两组MPAP继续升高,两组CVP升高,差异有统计学意义(P＜0.05).CO2-HF组MAP及dP/dtmax下降、SVI继续降低,SVRI继续增加,差异具有统计学差异(P＜0.05).结论 心功能不全新生猪进行长时间气体充填时CO2气腹对心功能影响明显,导致心肌收缩力明显下降及系统血管阻力明显增加;心功能不全新生猪进行长时间N2O气腹充填时心功能无进一步下降趋势.

Abstract：

Objective This experiment established a pneumoperitoneum model and acute cardiac failure model in piglets. It studies changes of hemodynamics of extended artificial pneumoperitoneum with CO2 and N2O in piglets with cardiac dysfunction. Methods Fourteen piglets (2-4 kilogram in weight,7-14 days of age) were divided into two groups: cardiac failure & CO2 group (CO2-HF) and cardiac failure & N2O group (N2O-HF). Both group underwent 4 hours of pneumoperitoneum. Measurements were carried out 5min before anaesthesia, 15,60,120, 180,240 min after establishing pneumoperitoneum and 30 min after deflation. Investigation included heart rete, stroke volume index, cardiac index, mean arterial pressure, central venous pressure, mean pulmonary arterial pressure, systemic vascular resistance index and dP/dtmax. Results In CO2-HF and N2O-HF groups,compared to the preoperative baseline, HR, SVI and CI decreased (P＜0. 05 ), while MPAP and SVRI increased (P＜0. 05). There was no statistical alteration in dP/dtmax, MAP and CVP. Post-operatively, HR were stable in both groups, CI decreased further, MPAP increased further and CVP increased(P＜0. 05). In CO2-HF group, MAP and dP/dtmax decreased,SVI decreased further and SVRI increased further(P＜0. 05). Conclusions Cardiac contractility decreased and systemic vascular resistance index increased significantly during extended CO2 pneumoperitoneum in piglets with compromised heart function. There was no deterioration of heart function with extended N2O pneumoperitoneum in piglets with heart failure.     

Clinical feature analysis of subdural effusion/hematoma after shunt use of adjustable valves in children with hydrocephalus北大核心CSCD

Objective To analyze the clinical data of children with hydrocephalus suffering from subdural effusion/hematoma after shunt(SEHS) with adjustable valves, and to provide reference for postoperative follow - up. Methods A total of 102 children with hydrocephalus treated with adjustable valves in the Department of Neurosurgery, Wuhan Children's Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from August 2017 to September 2021 were enrolled and studied retrospectively. There were 16 cases with SEHS, 11 of whom were male and 5 were female. The age ranged from 3 months to 13 years (median;2. 5 years). The age, clinical manifestations, the time of SEHS occurrence, treatment methods (pressure regulation only or combined with drilling and drainage), and prognosis of the patients were analyzed. The pressure adjustment treatment was to increase the by 10-20 mmH2O (1 mmH2O =0.0098 kPa) each time and the patients were followed up 2-4 weeks after the adjustment. If SEHS didn't improve according to the follow - up results, pressure regulation combined with drilling and drainage was recommended. Results Of the 16 patients with SEHS, 3 cases were over 3 years old, and the other 13 cases were 3 years old or below. Eleven cases were treated by pressure regulation only, and 5 cases who were all aged 3 years received pressure regulation combined with drilling and drainage. Symptoms occurred in 2 patients, including vomiting in 1 case, and head and limb shaking in the other case. Fourteen cases were asymptomatic. The time from shunt operation to the occurrence of SEHS was 1 month in 5 cases, who were all cured by pressure regulation only. SEHS occurred in 5 cases > 1-3 months after shunt surgery, and 2 cases of them were treated by pressure regulation combined with drilling and drainage. Three cases had SEHS > 3-6 months after shunt surgery, and 1 case of them was treated by pressure regulation combined with drilling and drainage. SEHS occurred in 3 cases more than 6 months after shunt surgery, and 1 case of them was treated by pressure regulation combined with drilling and drainage. For the patients who received pressure regulation combined with drilling and drainage, the time from shunt operation to the occurrence of SEHS was 1 month and 21 days, 2 months and 7 days, 4. 5 months, 7. 5 months, and 25. 0 months, respectively. The time from the occurrence of SEHS to the last reexamination with no SEHS detected was 1 month in 7 cases (all were cured by pressure regulation only); >1-3 months in 5 cases (3 cases were treated by pressure regulation combined with drilling and drainage); more than 3 months in 4 cases (2 cases were treated by pressure regulation combined with drilling and drainage). For the patients who received pressure regulation combined with drilling and drainage, the time from the occurrence of SEHS to the last reexamination with no SEHS detected was 1 month and 14 days, 2. 0 months, 3. 0 months, 7. 0 months and 8. 0 months, respectively. Except for 2 cases who experienced pressure regulating valve failure, all other cases were cured. Six cases were unilateral SEHS, and the SEHS volume was about 11 to 75 mL (median;39. 0 mL). Ten cases were bilateral SEHS, and the SEHS volume was about 23-380 mL (median; 158. 2 mL). The 6 cases were all cured by pressure regulation, and 5 cases of them had SEHS at the shunt tube insertion side. Conclusions SEHS in children with hydrocephalus is generally asymptomatic and rarely causes clinical symptoms. SEHS mostly occurs within 6 months after operation, especially within 3 months. SEHS found in 1 month after surgery can be cured by increasing the shunt valve pressure only. Therefore, SEHS can be cured by pressure regulation only by shortening follow - up and identifying SEHS early after shunt operation. This will also reduce the probability that patients require the drilling and drainage operation. © 2022 ＣｈｉｎＪＡｐｐｌＣｌｉｎＰｅｄｉａｔ. All rights reserved.     

Effect of epigallocatechin-3-gallate (EGCG) on the expressions of nuclear faclor-E2 related factor2 (Nrf2)and γ-glutamylcystein synthase (γ-GCS) in renal tubular epithelial cells of rats with oxidative Stress

Objective To investigate the mechanism of antioxygen reaction of epigallocatechin-3-gallate (EGCG) in renal tubular epithelial cells of rats with oxidative stress induced by H2O2. Methods Cultured cells were divided into control group, H2O2 group and EGCG group. Cell survival was observed with MTT. The expressions of Nrf2 mRNA and -γ-GCS mRNA in cultured cells were examined by real time quantitative PCR. Immunohistochemistry and western blotting were used to detecte the expressions of Nrf2 and γ-GCS protein. Results The survival rate of tubular cells was 97. 61 ± 6.33 in control group. There was a significant decrease in H2 O2 group (56. 38 ± 5.57) (P < 0.01), while increased when the EGCG concentration were 5,10,20 mg/L(77.42 ±5.31,83.27 ±5.94,90.24 ±5.72) (P <0.05,P <0.01). EGCG up-regulated the expressions of Nrf2 and γ-GCS mRNA and protein in renal tubular epithelial cells with dose depen-dentment. Conclusion The expressions of Nrf2 and-γ-GCS increase in renal tubular epithelial cells with oxidative stress. Resulting from suppression of oxidative stress,EGCG exerts protective effect on NRK,and this antioxidative effect may be partly induced by activating the Nrf2 signal pathway.     

Effect of epigallocatechin-3-gallate (EGCG) on the expressions of nuclear faclor-E2 related factor2 (Nrf2)and γ-glutamylcystein synthase (γ-GCS) in renal tubular epithelial cells of rats with oxidative Stress

Objective To investigate the mechanism of antioxygen reaction of epigallocatechin-3-gallate (EGCG) in renal tubular epithelial cells of rats with oxidative stress induced by H2O2. Methods Cultured cells were divided into control group, H2O2 group and EGCG group. Cell survival was observed with MTT. The expressions of Nrf2 mRNA and -γ-GCS mRNA in cultured cells were examined by real time quantitative PCR. Immunohistochemistry and western blotting were used to detecte the expressions of Nrf2 and γ-GCS protein. Results The survival rate of tubular cells was 97. 61 ± 6.33 in control group. There was a significant decrease in H2 O2 group (56. 38 ± 5.57) (P < 0.01), while increased when the EGCG concentration were 5,10,20 mg/L(77.42 ±5.31,83.27 ±5.94,90.24 ±5.72) (P <0.05,P <0.01). EGCG up-regulated the expressions of Nrf2 and γ-GCS mRNA and protein in renal tubular epithelial cells with dose depen-dentment. Conclusion The expressions of Nrf2 and-γ-GCS increase in renal tubular epithelial cells with oxidative stress. Resulting from suppression of oxidative stress,EGCG exerts protective effect on NRK,and this antioxidative effect may be partly induced by activating the Nrf2 signal pathway.     

腔镜下腋、颈部入路胸锁乳突肌松解术矫正先天性肌性斜颈

Objective A transaxillary and transcervical endoscopy technique was developed for the release of the sternocleidomastoid muscle in congenital muscular torticollis. The efficacy of the op-eration was evaluated. Methods A total of 34 children with congenital torticollis were treated. The age ranged from 6 month to 14 years. A 5 nun trocar was inserted in the anterior axillary fold. A subcuta-neous tunnel perpendicular to the axis of the sternocleidomastoid was made, initially under direct vision and then endoscopically using a 5 mm endoscope. A subcutaneous space was established with CO2 in-flation at the pressure of 6 mm Hg. Another two 1.5～2 mm incisions were made besides sternocleido-mastoid for the introduction of mini forceps and electric knife, respectively. The sternocleidomastoid muscle and scalene were dissected out and divided with electrocautery. Lee's evaluation was carried out post-operatively. Results The operation was successfully completed under endoscope in all children. The mean operation time was 50 min ( range: 40～120 min). No injury of major nerve was encoun-tercel Haemorrage in one child required re-operation. Follow-up for 6 months to 3 years showed satis-factory cosmetic appearance and no recurrence. The results were classified as excellent in 88.2 %, good in 8.8%,and fair in 3.0%. The neck scars were not visible one month after surgery. Conclusions Transaxillary and transcervical endoscopic release of congenital torticollis is a safe and relatively quick procedure. It provides good access and good cosmetic outcomes. It avoids injury to neurovascular struc-tures.     

腔镜下腋、颈部入路胸锁乳突肌松解术矫正先天性肌性斜颈

Objective A transaxillary and transcervical endoscopy technique was developed for the release of the sternocleidomastoid muscle in congenital muscular torticollis. The efficacy of the op-eration was evaluated. Methods A total of 34 children with congenital torticollis were treated. The age ranged from 6 month to 14 years. A 5 nun trocar was inserted in the anterior axillary fold. A subcuta-neous tunnel perpendicular to the axis of the sternocleidomastoid was made, initially under direct vision and then endoscopically using a 5 mm endoscope. A subcutaneous space was established with CO2 in-flation at the pressure of 6 mm Hg. Another two 1.5～2 mm incisions were made besides sternocleido-mastoid for the introduction of mini forceps and electric knife, respectively. The sternocleidomastoid muscle and scalene were dissected out and divided with electrocautery. Lee's evaluation was carried out post-operatively. Results The operation was successfully completed under endoscope in all children. The mean operation time was 50 min ( range: 40～120 min). No injury of major nerve was encoun-tercel Haemorrage in one child required re-operation. Follow-up for 6 months to 3 years showed satis-factory cosmetic appearance and no recurrence. The results were classified as excellent in 88.2 %, good in 8.8%,and fair in 3.0%. The neck scars were not visible one month after surgery. Conclusions Transaxillary and transcervical endoscopic release of congenital torticollis is a safe and relatively quick procedure. It provides good access and good cosmetic outcomes. It avoids injury to neurovascular struc-tures.     

腔镜下腋、颈部入路胸锁乳突肌松解术矫正先天性肌性斜颈

Objective A transaxillary and transcervical endoscopy technique was developed for the release of the sternocleidomastoid muscle in congenital muscular torticollis. The efficacy of the op-eration was evaluated. Methods A total of 34 children with congenital torticollis were treated. The age ranged from 6 month to 14 years. A 5 nun trocar was inserted in the anterior axillary fold. A subcuta-neous tunnel perpendicular to the axis of the sternocleidomastoid was made, initially under direct vision and then endoscopically using a 5 mm endoscope. A subcutaneous space was established with CO2 in-flation at the pressure of 6 mm Hg. Another two 1.5～2 mm incisions were made besides sternocleido-mastoid for the introduction of mini forceps and electric knife, respectively. The sternocleidomastoid muscle and scalene were dissected out and divided with electrocautery. Lee's evaluation was carried out post-operatively. Results The operation was successfully completed under endoscope in all children. The mean operation time was 50 min ( range: 40～120 min). No injury of major nerve was encoun-tercel Haemorrage in one child required re-operation. Follow-up for 6 months to 3 years showed satis-factory cosmetic appearance and no recurrence. The results were classified as excellent in 88.2 %, good in 8.8%,and fair in 3.0%. The neck scars were not visible one month after surgery. Conclusions Transaxillary and transcervical endoscopic release of congenital torticollis is a safe and relatively quick procedure. It provides good access and good cosmetic outcomes. It avoids injury to neurovascular struc-tures.     

肌松药对新生儿及婴儿腹腔镜手术操作空间的影响

目的观察新生儿及3个月以内婴儿腹腔镜手术中，使用肌松药对手术操作空间的影响。方法将40例腹腔镜手术患儿，随机分为对照组（Ⅰ组）和肌松组（II组），每组各20例，分别予5mmHg和10mmHg气腹压力建立人工C02气腹，并记录气腹前、5mmHg及10mmHg气腹压力下两组患儿腹围的变化。结果气腹前Ⅰ组腹围（31．90±2．15）cm，Ⅱ组腹围（32．25±2．37）cm，t=0．489，P=0．628，两组腹围比较，差异无统计学意义（P〉0．05）；气腹压力5mmHg时，Ⅰ组腹围（33．98±2．27）cm，Ⅱ组腹围（35．61±2．52）cm，t=2．150，P=0．038，Ⅱ组腹围值高于Ⅰ组（P〈0．05）。气腹压力10mmHg时，Ⅰ组腹围（35．13±2．34）cm，Ⅱ组腹围（36．95±2．53）cm，t=2．364，P=0．023，Ⅱ组腹围值亦高于Ⅰ组（P〈0．05）。结论在相同气腹压力下，肌松药的使用可有效增加腹腔容积，从而降低对CO2气腹压力的需求，并进一步降低CO2气腹对呼吸循环功能的影响。     

CO2气腹对新生猪呼吸和循环功能的影响

目的 建立新生猪气腹模型,观察CO2气腹中初生乳猪呼吸和循环功能相关指标的变化规律.方法 乳猪共14头,年龄7～14d,体重2～4kg.分为2组:CO2气腹组7头,对照组7头.麻醉后监测心率、动脉压、中心静脉压、心输出量、每搏输出量,全身血管阻力、左心室内压变化速度、动脉血气.监测时间为麻醉稳定后手术开始前5min,手术开始后15min、60min、120min,关腹后60min.结果 与对照组相比,实验组心率、全身血管阻力及左室内压变化速度增加,差异有统计学意义(P＜0.05).与对照组相比较,气腹后心输出量、每搏输出量下降,差异有统计学意义(P＜0.05).平均动脉压有升高趋势,但统计学意义不大.中心静脉压无明显变化.PaCO2增高(P＜0.05)、伴有pH下降,表现为轻度的呼吸性酸中毒,CO2气腹不引起新生猪血氧分压下降及血氧饱和度下降.结论 健康乳猪在严密监测下可以耐受短时间气腹.     

Local and systemic impact of pnemoperitoneum on prepuberal rats

Pneumoperitoneum (PN) and the gas used to insufflate the abdominal cavity during laparoscopy seem to be responsible for local and systemic modifications. The aim of this study was to verify the effects of intra-abdominal carbon dioxide (CO₂) and air insufflation on the peritoneum, as well as the cortico-surrenal response in prepuberal rats. Sixty prepuberal rats were divided into three groups: in the first (S, n = 36), PN was induced with CO₂, whereas in the second (A, n = 14), it was induced with filtered room air; in both conditions, insufflation lasted 30 min at a pressure of 10–12 mmHg. The third group (C, n = 10), underwent general anesthesia only. Two hours after inducing anaesthesia, 12 rats in group S, 6 in group A and 6 in group C were killed and the remaining, after 24 h; specimens of the visceral and the parietal peritoneum were obtained for histological examination, blood sample was taken for cortisol and DHEA-S assays at the different study periods. At the histological examination performed 2 h later, the groups S and A presented inflammatory cell infiltrate in the parietal and visceral peritoneum; this finding was even more marked in group A, which presented also congestion, hemorrhage and disruption of the cell line. Twenty-four hours after the experiment, the peritoneum of the two insufflated groups presented chronic infiltrate and reactive mesothelial cells with congestion, which was more evident in group A, but totally absent in group C. Cortisol levels were significantly higher in groups S and A (2.15:1 ratio) killed 2 h later compared to those killed 24 h later and to the control group. DHEA-S levels were not significantly different between the groups. Our results demonstrate that the chemical, physical and molecular impact of CO₂ on the peritoneum causes inflammation and tissue damage, this was even more evident 24 h after our experiment and in the air insufflated group. PN induced a significant variation in blood cortisol levels at 2 h. The CO₂ insufflation should be limited in patients with pre-existing peritoneal damage.     

无创正压通气在重症支气管哮喘治疗中的应用

目的 观察在常规治疗的基础上加用无创正压通气(NIPPV)对儿童重症支气管哮喘(哮喘)的治疗作用.方法 选取急性发作期重症哮喘患儿40例.随机分为NIPPV组20例和对照组20例.NIPPV组在解痉平喘、抗感染、祛痰、纠正酸碱和水电解质平衡等综合治疗基础上,于发病24 h内予NIPPV治疗;对照组除上述基础治疗外予鼻导管吸氧.监测2组治疗前及治疗4 h、8 h、12 h 及24 h心率、动脉血pH、动脉血氧分压 [pa(O2)]、动脉血二氧化碳分压[pa(CO2)]、血氧饱和度(SpO2)水平.结果 治疗后对照组和NIPPV组心率、动脉血pH值、pa(O2)、pa(CO2)及SpO2水平均较治疗前明显改善,并且随治疗时间的延长而改善有所增加,差异均有统计学意义(Pa<0.01).治疗后,NIPPV组较对照组改善更明显,NIPPV组在治疗4 h、8 h的心率[(119±10)次·min-1、(97±12)次·min-1]、动脉血pH(7.28±0.06、7.34±0.04)、pa(O2)[(67±6) mmHg、(81±5) mmHg](1 mmHg=0.133 kPa)、pa(CO2)[(40±9) mmHg、(31±9) mmHg]、SpO2[(96.23±1.83)%、(98.04±1.32)%]较对照组心率[(125±11)次·min-1、(104±10)次·min-1]、动脉血pH(7.22±0.08、7.29±0.07)、pa(O2)[62±6) mmHg、(76±4) mmHg]、pa(CO2)[(46±9) mmHg、(37±7) mmHg]及SpO2 [(95.05±1.69)%、(97.01±1.41)%]均明显改善,差异均有统计学意义(Pa<0.05).48 h后NIPPV组患儿全部脱机成功,且无严重并发症发生.结论 早期应用NIPPV配合常规药物治疗有助于减缓重症哮喘的病情恶化,可提高急性发作的治疗效果,是抢救重症哮喘的一种安全有效的方法.     

Tissue oxygen available as a criterion for the effectiveness of continuous positive pressure breathing.

As little as 3-5 cm H2O increase in proximal airway pressure applied to normal lung reduces cardiac output. It is postulated that decreased pulmonary compliance in respiratory distress syndrome (RDS) acts as a barrier thus offsetting this effect. Since cardiac output is not routinely measured, severe reduction in it could accompany regression of disease while maintaining the same airway pressure. This study was undertaken to determine whether tissue oxygen available (O2a) could be used to detect changes in perfusion during continuous positive pressure breating (CPPB). CPPB was evaluated in 10 normal rabbits (CL = 9.5 +/- 1.8 cc/g at 25 cm H2O) and in 10 pulmonary-damaged rabbits (CL = 5.5 +/- 1.4 cc/g at 25 cm H2O) produced by subjecting them to 100% O2. Airway pressure was increased from 0-15 cm H2O in 3 cm H2O increments at 10-min intervals. O2a and PaO2 were monitored continuously. In the normal group, O2a decreased at 3 cm H2O airway pressure, reaching 22% of control at 12 cm H2O, at which pressure PaO2 decreased. Breathing 100% O2 at this airway pressure increased PaO2 to 408 mm Hg, whereas O2a returned to 45% of control. In the experimental group, O2a decreased at 9 cm H2O airway pressure, at 12 cm H2O it was 36% of control at which pressure PaO2 decreased slightly. Breathing 100% O2 at this airway pressure increased PaO2 to 316 mm Hg, and increased O2a to 200% of control. These data indicate that with excessive airway pressure, muscle hypoxia may exist during systemic hyperoxemia and that a low compliance lung exerts a protective effect on O2a. Since changes in cardiac output during CPPB are compliance dependent, and since O2a is perfusion dependent, tissue oxygen available could provide a means of selecting optimal airway pressure during CPPB.     

Carbon dioxide modifies the morphology and function of mesothelial cells and facilitates transepithelial neuroblastoma cell migration

Background

The response of mesothelial cells to surgical trauma and bacterial contamination is poorly defined. We have recently shown that CO₂ pneumoperitoneum increases systemic metastasis of neuroblastoma cells in a murine model. Thus, we hypothesized that CO₂ alters the morphology and function of mesothelial cells and facilitates transmesothelial tumor cell migration.

Materials and methods

Murine mesothelial cells were exposed to 100% CO₂ and 5% CO₂ as control. Scanning electron microscopy (SEM) investigations, as well as LPS-induced granulocyte-colony stimulating factor (G-CSF) production and mitochondrial activity (MTT assay) were measured. Transmesothelial migration of neuroblastoma cells (Neuro2a) was determined using a transwell chamber system.

Results

CO₂ incubation was associated with a significant destruction of the microvillar formation in SEM. Migration studies showed that the barrier function of the mesothelial monolayer decreased. A significantly increased migration of neuroblastoma cells was identified after 100% CO₂ exposure (P < 0.05). Although the conversion of MTT as an indicator of mitochondrial activity was only slightly and not significantly reduced after CO₂ incubation, the release of G-CSF induced by LPS was completely blocked during the incubation with 100% CO₂ (P < 0.05). The capacity of G-CSF release recovered after the incubation.

Conclusion

We observed that peritoneal mesothelial cells lose their typical cell morphology by CO₂ incubation, which is accompanied by facilitated migration of neuroblastoma cells. Moreover, the synthesis of immunological factors is blocked, but this effect is not long lasting. These mechanisms may explain an increased metastasis rate of neuroblastoma cells after CO₂ pneumoperitoneum, which was recently observed in a murine model.     

The effects of lung distension, oxygenation, and gestational age on fetal behavior and breathing movements in sheep

Lung distension with 100% O2 at a continuous positive airway pressure of 30 cm H2O may induce continuous fetal breathing movements (FBM) in sheep. The objectives of this study were 1) to investigate the relative roles of lung distension and oxygenation and 2) to test the hypothesis that FBM can be induced during labor, when normally they are greatly reduced or absent. We studied 13 chronically instrumented, unanesthetized fetal sheep between 128 and 144 d of gestation (term = 147 +/- 2 d). Each fetus was instrumented to record sleep states, diaphragm electromyogram, blood pressure, arterial pH, and blood gas tensions. The fetal lungs were distended via an in situ endotracheal tube with four different concentrations of O2 (0, 21, 50 and 100%) at a continuous positive airway pressure of 10, 20 and 30 cm H2O in a randomized order. No change in any recorded physiologic variable was observed at 129 +/- 1 or 132 +/- 1 d of gestation. At 135 +/- 1 and 138 +/- 1 d, in response to a continuous positive airway pressure of 30 cm H2O and 100% O2, pH decreased (p = 0.0004 and 0.005, respectively) and arterial O2 tension increased (p = 0.004 and 0.02, respectively). However, increases in 1) breathing time, 2) breathing time/low-voltage electrocortical activity ratio, 3) duration of arousal, and 4) length of single breathing epochs were observed only at 138 +/- 1 d. Lung distension with N2 resulted in a decrease in FBM. Six fetuses were studied during labor.(ABSTRACT TRUNCATED AT 250 WORDS)