腹腔镜下处理输卵管积水对体外受精胚胎移植结局的影响

目的探讨腹腔镜下处理输卵管积水对体外受精胚胎移植(in vitro fertilization and embryo transfer, IVF-ET)结局的影响.方法 2002～2005年在我院行IVF-ET伴输卵管积水的53例分3个研究组:①未处理组17例,仅行IVF-ET,未对积水进行处理;②直接切除组17例,行IVF-ET术前在腹腔镜下处理输卵管积水;③失败后切除组19例,IVF-ET失败后腹腔镜下处理输卵管积水后再行IVF-ET.结果未处理组新鲜移植周期妊娠率15.8%(3/19),解冻周期妊娠率10.5%(2/19),平均周期妊娠率13.2%(5/38),累积活胎率17.6%(3/17);直接切除组分别为36.8%(7/19),23.1%(3/13),30.3%(10/32),41.7%(8/17);失败后切除组分别为16.7%(2/12),58.3%(14/24),44.4%(16/36),73.7%(14/19).失败后切除组的解冻周期妊娠率、平均周期妊娠率及累积活胎率均高于未处理组(χ2＝10.374,P＝0.001;χ2＝8.903,P＝0.003;χ2＝11.305,P＝0.001),直接切除组平均周期妊娠率及累积活胎率呈高于未处理组的趋势(χ2＝3.377,P＝0.066;χ2＝3.360,P＝0.067).结论输卵管积水降低IVF-ET的妊娠率,妊娠结局不良,腹腔镜下处理输卵管积水后再行IVF-ET提高妊娠率,获得良好的妊娠结局.     

可溶性fms-样酪氨酸激酶受体-1不同基因片段对视网膜新生血管的抑制作用

Objective To investigate the inhibitory effects of fms-like typrosine kinase receptor sFh-1 on retinal neovascularization (RNV). Methods Recombinant lentivirus sFh-1 ( 2-3 ) and sFh-1 ( 2-4 )expressing the sFh-1 (2-3) and (2-4) immunoglobulin-like regions of sFh-1 were constructed. 96 seven-dayold C57/6J mice were randomly divided into 4 groups with 24 mice in each group. Group 1 : normal control;group 2: experimental control; group 3: sFlt-1(2-3); group 4: sFlt-1(2-4). The mice in group 2-4 were exposed to hyperoxia with (75±2)% O2 for 5 days and then returned to normoxia with 21% O2 ; the mice     

Seminal Fluid and the Expression of MHC Class I Antigens in the Placenta of the Rat

PROBLEM : To determine whether seminal fluid influences the expression of MHC class I antigens on the surface of basal trophoblast cells in the placenta of the rat. METHODS : Transfer of DA × DA embryos into a WF (allogeneic) or DA (syngeneic) recipient made pseudopregnant by hormonal treatment followed by mating with a vasectomized male (seminal fluid) or by mechanical stimulation (no seminal fluid). Antigen expression was determined by electron microscopic immunocytochemistry using the appropriate gold-labeled monoclonal antibodies. RESULTS : Seminal fluid did not affect the expression of MHC class I antigens on the surface of the basal trophoblast in either allogeneic or syngeneic matings. CONCLUSIONS : The suppression of the expression of paternal class I antigens on the surface of the basal trophoblast cells in allogeneic pregnancies most likely occurs at the genome level shortly after fertilization.     

Genetically modified fibroblasts induce angiogenesis in the rat epigastric island flap

Methods: Gene therapy was tested for inducing functional angiogenesis in the superficial rat epigastric island flap to allow earlier pedicle division. Autologous rat fibroblasts were grown, harvested, cultured and retrovirally transfected to produce platelet-derived growth factor AA (PDGF-AA), an angiogenetically active protein. Stable gene expression was monitored by PDGF-AA enzyme-linked immunosorbent assay (ELISA). One hundred and eighty animals were divided into three groups (I–III) and a bilateral flap created in each animal. In all experiments, the right-sided flap was subjected to experimental treatment and the left-sided flap served as control (1 ml saline 0.9%). During flap elevation, group I received 5×10⁶ GMFB (genetically modified fibroblasts) plus 1 ml Dul-becco's modified Eagle's medium. Group II was treated with 5×10⁶ NMFB (non-modified fibroblasts) plus 1 ml medium and group III received 1 ml medium only. The flaps were sutured back and the vascular pedicle was bilaterally ligated and divided in each of ten animals during the following 6 days. After 7 days, the flaps were harvested, the amount of necrosis measured and histologically examined. Results: The GMFB produced up to 560 times more PDGF-AA than the NMFB, measured by ELISA. The GMFB-treated flaps tolerated surgical division of the vascular pedicle significantly earlier than groups II and III. Histologically, fibroblasts persisted in all flaps of groups I and II, without major inflammatory reaction. In all GMFB-treated flaps, massive angiogenesis could be demonstrated. Conclusion: By means of retroviral gene transfer, autologous rat fibroblasts can be genetically modified for stable expression of the PDGF-A gene to produce high amounts of PDGF-AA, which is angiogenetically active. After injection into the panniculus carnosus, these cells induce functional angiogenesis to permit earlier division of the vascular pedicle in this flap model. Received: 5 January 1998 / Accepted: 17 June 1998     

Magnetization Transfer and T2 Relaxation Components in Tissue

T₂ relaxation makes an important contribution to tissue contrast in magnetic resonance (MR) imaging. Many tissues are known to exhibit multicomponent T₂ relaxation that suggests some compartmental segregation of mobile protons on a T₂ timescale. Magnetization transfer (MT) is another relaxation mechanism that can be used to produce tissue contrast in MR imaging. The MT process depends strongly on water-macromolecular interactions. To investigate the relationship between multicomponent T₂ relaxation and the MT process, multiecho T₂ measurements have been combined with MT measurements for freshly excised samples of cardiac muscle, striated muscle, and white matter. For muscle, short T₂ components show greater MT than long T₂ components, consistent with the belief that they represent distinct water environments. For white matter, quantitative MT measurements were identical for the two major T₂ components, apparently because of exchange between the T₂ compartments on a timescale characteristic of the MT experiment. Implications for accurate modeling of MT in tissue and the use of MT for MR image contrast are discussed.     

环隙气升式反应器在非牛顿流体体系中的应用──反应器特性研究和体积氧传递系数的关联

以羧甲基纤维素钠（ＣＭＣ）水溶液模拟非牛顿型发酵介质，在内径为０．１５ｍ，高为０．９７５ｍ的环隙气升式反应器内，考察了液体流变性质和导流筒结构对气液传质的影响，提出了体积氧传递系数（ＫＬａ）的经验关联式。实验表明：对于较高粘度的假塑性流体，反应器内部采用整体式导流筒结构，将有利于传质和混合，其性能优于采用开窗式导流筒或无导流筒的反应器。     

玻璃熔窑蜂窝状窑顶的节能机理及效果

根据窑顶辐射率，内表面积和角系数的变化，窑顶，胸墙和玻璃液面温度的改变，以及火焰－窑顶－胸墙－玻璃液面四者之间的辐射热交换，阐明了熔窑蜂状窑顶的节能机理。用计算机通过实例计算，定量表明了蜂窝状窑顶的节能效果。     

Maintenance and synthesis of proteins for an anucleate axon

The anucleate (distal) segment of a crayfish medial giant axon (MGA) remains intact for months in vivo after severing the axon from its cell body, a phenomenon referred to as long-term survival (LTS). We collected axoplasm from chronic anucleate MGAs by perfusing 2-cm lengths of axons with an intracellular saline. This axoperfusate was analyzed by SDS-PAGE and silver stained. Axoperfusate proteins from intact MGAs and from chronic anucleate MGAs exhibiting LTS for up to 6 months were the same. Furthermore, immunoreactive levels of actin and β-tubulin were similar in axoperfusates from intact and chronic anucleate MGAs. This maintenance of proteins in chronic anucleate MGAs must be due to a lack of protein degradation and/or to local protein synthesis by a source other than the cell body. To investigate local protein synthesis in vitro, we added [³⁵S]-methionine to the extracellular saline surrounding intact and chronic anucleate MGAs. After 4- to 6-h incubations, radiolabelled proteins were detected in axoperfusates analyzed by SDS-PAGE and fluorography. The similarity between radiolabelled proteins in axoperfusates and MGA glial sheaths indicated a glial origin for the radiolabelled axoperfusate proteins. Various observations and control experiments suggested that glial-axonal protein transfer occurred by a physiological process. Glial-axonal protein transfer may contribute to the maintenance of proteins during LTS of chronic anucleate MGAs.     

Magnetization transfer imaging of multiple sclerosis

While conventional magnetic resonance imaging (MRI) measures signal primarily from the hydrogen nuclei of water, magnetization transfer (MT) MRI indirectly detects macromolecular associated hydrogen nuclei via their magnetic interaction with the observable water. In the normal adult CNS, white matter exhibits the largest MT effect due to the macromolecular content of the highly structured and lipid rich myelin. Pathologies which alter the structural integrity and the relative macromolecular-water composition, such as multiple sclerosis (MS), therefore show abnormal MT. Conventional MRI, which has a high MS lesion detection sensitivity but poor specificity in terms of differentiating the pathological state of a plaque, can thus be supplemented by MT to provide more specific information on the extent of demyelination and axonal loss. In this paper we review the basic concepts of MT imaging and its role in MS lesion characterization.Financial support was provided by the Medical Research Council of Canada, Fonds de la Recherche en Santé du Québec, and the Killam Foundation.