Mechanical model testing of rebreathing potential in infant bedding materials

Rebreathing of expired air may be a lethal hazard for prone sleeping infants. This paper describes a mechanical model to simulate infant breathing, and examines the effects of bedding on exhaled air retention. Under simulated rebreathing conditions, the model allows the monitoring of raised carbon dioxide (CO2) inside an artificial lung-trachea system. Resulting levels of CO2 (although probably exaggerated in the mechanical model compared with an infant, due to the model's fixed breathing rate and volume) suggest that common bedding materials vary widely in inherent rebreathing potential. In face down tests, maximum airway CO2 ranged from less than 5% on sheets and waterproof mattresses to over 25% on sheepskins, bean bag cushions, and some pillows and comforters. Concentrations of CO2 decreased with increasing head angle of the doll, away from the face down position. Recreations of 29 infant death scenes also showed large CO2 increases on some bedding materials, suggesting these infants could have died while rebreathing.     

Treatment of respiratory failure in an infant with bronchopulmonary dysplasia infected with respiratory syncytial virus using inhaled nitric oxide and high frequency ventilation

A 2-month-old, former 28-week premature infant with brochopulmonary dysplasia infected with respiratory syncytial virus was treated with nitric oxide and high frequency oscillatory ventilation after conventional therapy failed. Nitric oxide and high frequency oscillatory ventilation rapidly improved oxygenation allowing recovery without the need for extracorporeal membrane oxygenation. This treatment regimen should be considered as an option in high-risk infants with respiratory syncytial virus infection who meet extracorporeal membrane oxygenation criteria.     

人类风湿性关节炎滑膜-软骨-NOD．scid小鼠嵌合体模型的建立

目的:建立能反应自身免疫特点的类风湿性关节炎动物模型,为进一步研究该病发病机制奠定基础。方法:实验于2006-03/12在南方医科大学实验动物中心完成。①实验材料:SPF级2～4个月龄NOD.scid小鼠20只,体质量17～22g,雌雄各半;人类风湿性关节炎滑膜组织(佛山市第一人民医院风湿科提供,患者知情同意);骨关节炎滑膜及正常软骨(南方医院创伤骨科提供,患者及供者知情同意)。②实验分组:将小鼠随机分为2组,类风湿性关节炎滑膜组和骨关节炎滑膜组,雌雄不限,每组10只。③实验过程:每组小鼠背部皮下植入的正常软骨组织,随后将类风湿性关节炎滑膜和骨关节炎滑膜植入软骨之上。④造模10周后麻醉下处死小鼠,用放射免疫法检测血清中肿瘤坏死因子α含量,移植物进行组织病理学观察,并进行组织学积分。结果:①模型鼠一般情况:实验期间NOD.scid小鼠无手摸皮骨感、活动度差、毛稀疏等典型移植物抗宿主疾病表现,模型鼠在SPF环境下10周存活率100%。②肿瘤坏死因子α含量:类风湿性关节炎滑膜组鼠血清中肿瘤坏死因子α放射含量类风湿性关节炎组明显高于骨关节炎组[(0.80±0.06),(0.70±0.03)μg/L,t=4.466,P<0.001]。③组织病理学观察:苏木精-伊红染色,骨关节炎滑膜组只见少量的滑膜细胞增生和炎症细胞,移植的滑膜组织主要被纤维组织形成的条索状物代替,无明显地软骨被侵蚀破坏发生;类风湿性关节炎滑膜组可明显见到大量的滑膜细胞增生和生化中心形成,病变部位的组织结构间质变为疏松,变为境界不清晰的颗粒状或块状无结构强嗜酸性红染物质;软骨边缘被滑膜组织侵蚀破坏明显;类风湿性关节炎滑膜组滑膜增生、软骨侵蚀和软骨降解积分均高于骨关节炎滑膜组(P<0.04)。结论:在NOD.scid体内可成功建立类风湿性关节炎动物模型。     

许旺细胞基膜管与骨骼肌基膜管两种桥接体对大鼠脊髓损伤修复效果的比较

目的:比较许旺细胞基膜管与骨骼肌基膜管两种桥接体对脊髓损伤的修复效果。方法:实验于2005-08/2006-01在大连医科大学动物实验中心完成。①选取3月龄SD大鼠40只,随机数字表法分成4组:正常对照组、假手术组、许旺细胞基膜管移植组、骨骼肌基膜管移植组,10只/组。②许旺细胞基膜管移植组动物麻醉后,沿左上肢屈侧切开,取正中神经节段约1.0cm,经蒸馏水浸泡、液氮冷冻、生理盐水浸润再复温,挤出胞浆和崩解组织,修整成待移植的许旺细胞基膜管。骨骼肌基膜管移植组动物于左上肢三角肌取材后按类似过程制成待移植的骨骼肌基膜管。③除正常对照组外,其余各组均建立脊髓损伤模型。鼠尾呈痉挛性扑动,麻醉苏醒后左下肢完全瘫痪标志造模成功。④许旺细胞基膜管移植组将许旺细胞基膜管按走行方向植入脊髓切损处。骨骼肌基膜管移植组同法植入骨骼肌基膜管。假手术组、正常对照组不进行任何材料移植。观察动物存活情况、一般状态、伤口愈合、后肢溃疡情况及运动功能恢复等情况。⑤术后通过斜板试验观察大鼠左后肢负重功能恢复情况;并进行动物行为测试评分(满分7分,左后肢失去负重和行走功能为0分);测定皮层体感诱发电位;组织学观察和计算机图像分析半薄切片中轴突数目、直径以及石蜡切片中脊神经节细胞数。结果:40只大鼠全部进入结果分析。①移植术后一般情况:术后3周许旺细胞基膜管移植组、骨骼肌基膜管移植组左后肢有不同程度的运动功能恢复。术后8周动物全部存活,切口愈合较好。非正常对照组动物均发生胸腰段脊柱轻度侧弯畸形。②术后斜板试验结果:与正常对照组大鼠跌落时的木板倾斜度数比较,术后8周许旺细胞基膜管移植组、骨骼肌基膜管移植组大鼠跌落时的木板倾斜度数明显高于假手术组(t=2.378,P<0.05),但低于正常对照组(t=2.421,P<0.05)。③术后行为学测试结果:术后8周许旺细胞基膜管移植组、骨骼肌基膜管移植组行为评分与正常对照组基本相似(t=2.034,P>0.05),明显高于假手术组(t=3.647,P<0.01)。④术后皮层体感诱发电位检测结果:正常对照组可记录到潜伏期为(16.15±1.23)ms、波幅为(30.76±2.61)μV的皮层体感诱发电位波形。术后6周许旺细胞基膜管移植组潜伏期延长、波幅降低,但均优于骨骼肌基膜管移植组[(21.48±2.17),(26.72±1.83)ms;(23.74±2.02),(19.14±1.38)μV;P均<0.05];而假手术组未记录到相应皮层体感诱发电位波形。⑤术后大体及组织学观察结果:许旺细胞基膜管移植组其基膜管与脊髓交界处无明显瘢痕组织形成,移植物中再生轴索较多,辣根过氧化物酶示踪在宿主-移植物交界面头侧的正常脊髓前角内见较多标记神经元,再生轴突直径较粗,髓鞘较厚。骨骼肌基膜管移植组情况与其基本相似,但骨骼肌基膜管与脊髓交界处有少许瘢痕组织形成。⑥术后8周末轴突数目、轴突直径和脊神经节细胞数计算机图像分析结果:许旺细胞基膜管移植组的轴突数目、轴突直径和脊神经节细胞数目与正常对照组基本相似(t=2.116,P>0.05),但明显高于骨骼肌基膜管移植组、假手术组(t=2.494,P<0.05;t=3.573,P<0.01)。结论:许旺细胞基膜管比骨骼肌基膜管更适宜作为治疗脊髓损伤的桥接体材料。     

骨形态发生蛋白在大段同种异体骨移植中的表达

目的:通过动物实验来探讨骨形态发生蛋白在大段同种异体骨移植愈合中的表达及其意义。方法:实验于2005-10/2006-01在南京军区总院动物实验中心完成。①24只新西兰大白兔随机分为实验组和对照组各12只。实验组,手术移植用梯度降温深低温保存的同种异体兔股骨半髁植入,以金属螺钉固定;对照组将取下的自体股骨半髁原位植入,用与实验组相同的内固定方法固定。②术后4,8,12周取标本行大体标本观察,苏木精-伊红及骨形态发生蛋白免疫组织化学染色,观察骨形态发生蛋白在大段同种异体骨愈合过程的表达情况。结果:24只兔均进入结果分析。①两组移植骨段大体观察:第12周,实验组与对照组移植骨段已与宿主完全连接成一整体,外周骨痂已塑形。②两组自体骨与异体骨苏木精-伊红染色结果:第12周,实验组自体骨与异体骨间见较多成熟骨小梁,自体骨与异体骨连接处髓腔基本融合,于异体骨外侧新形成皮质骨结构。对照组已形成新皮质结构,有大量成熟的骨小梁结构,髓腔基本融合。③骨形态发生蛋白免疫组织化学染色结果:第4周:实验组皮质骨外周见较强的骨形态发生蛋白表达,阳性染色主要位于不成熟的骨细胞、成骨细胞、软骨细胞的胞浆及其分泌的基质中,表明骨形态发生蛋白通过“旁分泌”和“自分泌”的形式使得间质细胞分化为软骨细胞和骨细胞。对照组骨折断端两侧均有骨形态发生蛋白表达。第8周:异体皮质骨周围的骨痂中可见阳性表达,新形成的管状结构中呈“镶边”样排列的成骨细胞为阳性表达,其周围尚有一些软骨细胞核阳性表达。对照组与实验组相似,新生血管和新骨生成较实验组为多。第12周:实验组及对照组骨形态发生蛋白表达均较少。深低温保存的同种异体骨移植过程中骨形态发生蛋白表达与自体骨相似。骨形态发生蛋白染色在新生骨及其周围类基质表达阳性。结论:①骨形态发生蛋白在同种异体骨移植愈合早期起重要作用,其通过“旁分泌”和“自分泌”的形式使得间质细胞分化为软骨细胞和骨细胞,从而促使新骨形成。②大段同种异体骨移植愈合早期(4周)过程中骨诱导与骨吸收同时存在时,骨形态发生蛋白发生重要作用。     

人心脏型脂肪酸结合蛋白的纯化与鉴定

目的:以往的心脏型脂肪酸结合蛋白多来自牛、鼠等动物心肌组织,本实验构建了人左心室心肌组织纯化心脏型脂肪酸结合蛋白的新方法。方法:实验于2005-01/03在南京医科大学第一附属医院心血管病研究所完成。①实验材料:人心室肌由南京医科大学第一附属医院心血管病研究所提供。②实验过程:取20g人左心室肌在缓冲液中匀浆,多步骤离心后以(NH4)2SO4进行盐析→再次离心→沉淀缓冲液重悬透析得蛋白粗提液→Sephadex G-75凝胶过滤→电泳确定主要蛋白条带的收集管号合并收集→QSepharose Fast Flow阴离子交换层析→聚乙二醇浓缩→缓冲液透析得人心脏型脂肪酸结合蛋白。③实验评估:以SIGMA公司人心脏型脂肪酸结合蛋白为对照标准品;以Tricine-SDS-PAGE电泳鉴定相对分子质量;以鼠抗人脂肪酸结合蛋白单克隆抗体及羊抗鼠IgG对其进行Western印迹检测鉴定其特异性。结果:①Sephadex G-75凝胶过滤柱层析结果:各组分经Tricine-SDS-PAGE电泳检测证实,部分收集管中存在相对分子质量约14400的人心脏型脂肪酸结合蛋白。②阴离子交换柱层析结果:在洗脱液NaCl浓度达6mmol/L时,出现蛋白峰,人心脏型脂肪酸结合蛋白被洗脱;NaCl浓度达20mmol/L时,蛋白峰降至基线,蛋白洗脱结束。③纯化的人心脏型脂肪酸结合蛋白鉴定结果:经电泳显示其相对分子质量约为14000,纯度约为90%;Western印迹证实其可被抗人脂肪酸结合蛋白单克隆抗体特异识别,与对照标准品SIGMA公司人心脏型脂肪酸结合蛋白结果一致。实验从20g湿重心室肌中共纯化得到15.4mg心脏型脂肪酸结合蛋白,得率为0.77mg/g。结论:Sephadex G-75凝胶过滤柱层析及阴离子交换柱层析相结合,可用于人心脏型脂肪酸结合蛋白的纯化。     

Bispecific T-cells Expressing Polyclonal Repertoire of Endogenous γδ T-cell Receptors and Introduced CD19-specific Chimeric Antigen Receptor

Even though other γδ T-cell subsets exhibit antitumor activity, adoptive transfer of γδ Tcells is currently limited to one subset (expressing Vγ9Vδ2 T-cell receptor (TCR)) due to dependence on aminobisphosphonates as the only clinically appealing reagent for propagating γδ T cells. Therefore, we developed an approach to propagate polyclonal γδ T cells and rendered them bispecific through expression of a CD19-specific chimeric antigen receptor (CAR). Peripheral blood mononuclear cells (PBMC) were electroporated with Sleeping Beauty (SB) transposon and transposase to enforce expression of CAR in multiple γδ T-cell subsets. CAR⁺γδ T cells were expanded on CD19⁺ artificial antigen-presenting cells (aAPC), which resulted in >10⁹ CAR⁺γδ T cells from <10⁶ total cells. Digital multiplex assay detected TCR mRNA coding for Vδ1, Vδ2, and Vδ3 with Vγ2, Vγ7, Vγ8, Vγ9, and Vγ10 alleles. Polyclonal CAR⁺γδ T cells were functional when TCRγδ and CAR were stimulated and displayed enhanced killing of CD19⁺ tumor cell lines compared with CAR^negγδ T cells. CD19⁺ leukemia xenografts in mice were reduced with CAR⁺γδ T cells compared with control mice. Since CAR, SB, and aAPC have been adapted for human application, clinical trials can now focus on the therapeutic potential of polyclonal γδ T cells.     

The effect of interleukin 3 and GM-CSA-2 on megakaryocyte and myeloid clonal colony formation

Two separate helper T cell-derived lymphokines, interleukin 3 and granulocyte-macrophage colony-stimulating activity-2, were found to stimulate a broad and similar range of hemopoietic colonies in in vitro soft agar cultures including granulocyte, macrophage, granulocyte- macrophage, megakaryocyte, and mixed megakaryocyte colonies. Both lymphokines were potent stimulators of in vitro megakaryocyte colony formation. At plateau levels of IL-3, megakaryocyte colony formation was increased by biologic activity in pokeweed mitogen spleen- conditioned media.     

Hysteroscopic resection of vaginal septum in an adolescent virgin with obstructed hemivagina

This article reports on one patient with a double uterus, unilateral vaginal obstruction, with hemi-haematocolpos and ipsilateral renal agenesis. Early accurate diagnosis followed by the excision of the obstructing vaginal septum offers complete relief of symptoms, while preserving reproductive capacity. Unlike conventional excision of vaginal septum, we used resectoscope excision with cutting electrode under continuous pure distilled water irrigation. The postoperative course was uneventful, and haematocolpos and severe dysmenorrhoea disappeared. The resected vaginal area revealed re-epithelialization by hysteroscope follow-up one year after resection. With advancements in resectoscopic operation, evaluation and treatment of vaginal disorders in babies and virgins is very feasible.      

Cystic teratoma of the ovary: CT detection

Computed tomography (CT) was performed in 38 patients with 41 benign cystic teratomas of the ovary and two patients with malignant transformation. CT depicted all tumors. The presence of fat in 40 of 43 cases (93%), tooth or calcification in 24 of 43 (56%), Rokitansky protuberance in 35 of 43 (81%), tufts of hair in 28 of 43 (65%), and a fat-fluid level in five of 43 (12%) allowed a definite diagnosis of ovarian cystic teratoma in 42 of 43 cases (98%). In the two cases of malignancy, single large (greater than 10 cm) plugs (with uptake of contrast medium in one) with a cauliflower appearance and an irregular border forming an obtuse angle with the inner wall of the cyst suggested malignant transformation. In three cases of benign cystic teratoma, a mucinous tumor (one benign, one borderline, one malignant) arising in the same ovary was seen at pathologic examination but was only diagnosed with the help of CT in two of three cases. Thickening of the tube was noted in two cases of torsion of the adnexa. CT findings were compared with findings at radiography of the abdomen and hysterosalpingography in 30 cases, ultrasound in 31, and magnetic resonance imaging in three. This study demonstrated that CT was the best procedure for imaging cystic teratomas of the ovary.