Lupus anticoagulant IgG's (LA) are not directed to phospholipids only, but to a complex of lipid-bound human prothrombin.

Plasmas from 16 patients that were found to be positive both for anticardiolipin antibodies (ACA) and lupus anticoagulants (LA) were incubated with liposomes that contained anionic phospholipids. In 11 of these plasmas, ACA could be cosedimented with the liposomes in a dose-dependent manner, whereas LA activity of the remaining supernatant was unaffected. LA activity of purified total IgG from 6 patients was measured in three different coagulation tests, using normal plasmas from different species. Prolongation of the aPTT, KCT and dRVV clotting times was observed only with normal plasma from human origin, not with bovine, rat or sheep plasma. Highly purified coagulation factors Xa, Va and prothrombin, both of human and bovine origin, were used to establish for two patient IgG's the effect of LA on the rate of thrombin formation in the presence and absence of lipid vesicles composed of 20 mole% phosphatidylserine and 80 mole% phosphatidylcholine. A strong and dose dependent inhibition by LA was observed only when human prothrombin was used as substrate in the prothrombinase complex in the presence of lipids. No inhibition was found when bovine prothrombin was used as substrate. The inhibitory effect observed in the presence of human prothrombin was independent of the source of factors Xa and Va, and was not found in the absence of lipid. Preliminary binding studies suggest that LA only associate with a lipid surface, provided that human prothrombin and calcium ions are present. These data indicate that LA are not directed to phospholipids alone, but presumably recognize an epitope which becomes exposed upon Ca(2+)-mediated binding of human prothrombin to phospholipids.     

华蟾蜍毒素对离体豚鼠输精管的作用

华蟾蜍毒素(华蟾素)使离体豚鼠输精管产生剂量依赖性收缩反应,利血平化豚鼠输精管及冷藏输精管对华蟾素反应减弱。给酚妥拉明、维拉帕米后,输精管对华蟾素反应均受抑制,溴苄胺可使反应潜伏期缩短。结果提示华蟾素收缩输精管反应可能与其促进肾上腺素能神经末稍NA释放有关。     

Surgical sperm retrieval and intracytoplasmic sperm injection as treatment of obstructive azoospermia

Male genital tract obstructions may result from infections, previous inguinal and scrotal surgery (vasectomy) and congenital bilateral absence of the vas deferens (CBAVD). Microsurgery can sometimes be successful in treating the obstruction. In other cases and in cases of failed surgical intervention, the patient can be treated by microsurgical or percutaneous epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI). We present the results of 39 ICSI procedures for obstructive azoospermia in 24 couples. The aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD in nine and genital infections in four. Sperm retrieval was accomplished via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was only applied when PESA failed to produce enough spermatozoa for simultaneous ICSI. In six patients, the ICSI procedure was performed with cryopreserved spermatozoa after an initial PESA procedure. Fertilization occurred in 47% of the metaphase II oocytes; embryo transfer was performed in 92% of procedures and resulted in a clinical pregnancy in 13/39 procedures. Ongoing pregnancy was achieved in 10/39 procedures. One pregnancy was terminated early after prenatal investigation showed a cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine pregnancies resulted in the live birth of 10 children, without any congenital abnormalities. Epididymal and testicular retrieved spermatozoa were successfully used for ICSI to treat obstructive azoospermia, and resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI procedures, a success rate of 25.6% per treatment cycle and of 27.7% per embryo transfer.      

L1 knockout mice show dilated ventricles, vermis hypoplasia and impaired exploration patterns

L1 is a neural cell adhesion molecule mainly involved in axon guidance and neuronal migration during brain development. Mutations in the human L1 gene give rise to a complex clinical picture, with mental retardation, neurologic abnormalities and a variable degree of hydrocephalus. Recently, a transgenic mouse model with a targeted null mutation in the L1 gene was generated. These knockout (KO) mice show hypoplasia of the corticospinal tract. Here we have performed further studies of these KO mice including magnetic resonance imaging of the brain, neuropathological analysis and behavioral testing. The ventricular system was shown to be abnormal with dilatation of the lateral ventricles and the 4th ventricle, and an altered shape of the Sylvius aqueduct. Additionally, the cerebellar vermis of the KO mice is hypoplastic. Their exploratory behavior is characterized by stereotype peripheral circling reminiscent of that of rodents with induced cerebellar lesions.      

Cytokine production by the human bladder carcinoma cell line T24 in the presence of bacillus Calmette-Guerin (BCG)

Summary The study was initiated as an in vitro approach to the situation existing during intravesical bacillus Calmette-Guerin (BCG) instillation in patients with superficial bladder cancer. Cytokine secretion of a human bladder carcinoma cell line T24 treated with BCG was investigated. A 24-h treatment of T24 cells with BCG resulted in a tenfold higher secretion of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF) when compared with T24 cells treated with Escherichia coli, Streptococcus faecalis or a cell wall preparation of Nocardia rubra (N-CWS). No secretion of IL-1 and IL-2 was detected. Pre-exposing T24 cells to BCG for various periods of time indicated that a minimum exposure time of 0.5–1 h was required to upregulate IL-6 and TNF production. Extending the BCG pre-exposure time to 2 and 3 h further increased the rate of cytokine production. No significant difference was found, however, between the rate of secretion initiated after a 2-h or 3-h pre-exposure period. The amounts of these cytokines secreted in the presence of BCG-conditioned medium did not differ significantly from the constitutively secreted amounts, excluding an effect of products possibly secreted by BCG on the upregulation of IL-6 and TNF. In addition, upregulation of cytokine production appeared to be dependent on the concentration of BCG. The results suggest that cytokines may be produced by urothelial tumor cells after intravesical instillation in patients with superficial bladder cancer, which may play a role in the mode of action of BCG.     

维生素D_3对报告载体荧光素酶表达的作用

目的：　研究１,２５－二羟维生素Ｄ３ 对结肠癌细胞系Ｃａｃｏ－２ 细胞中报告基因表达的作用,并探讨在报告载体ｐＧＬ２ 序列中存在潜在的抑制性维生素Ｄ应答元件（ＶＤＲＥ）的可能性。方法：　采用磷酸钙沉淀法将报告载体转染入Ｃａｃｏ－２ 细胞。Ｃａｃｏ－２细胞经不同浓度１,２５－二羟维生素Ｄ３ 处理后测定细胞裂解液中表达的荧光素酶活性。结果：　应用ｐＧＬ２ 报告载体时,当用ｐＳＧ５－ＶＤＲ表达载体共转染后,１,２５－二羟维生素Ｄ３显著地抑制Ｃａｃｏ－２ 细胞荧光素酶的表达（Ｐ＜ ０．０５）;而未使用该表达载体共转染则无抑制作用（Ｐ＞ ０．０５）。应用ｐＧＬ３ 报告载体时,不同浓度的１,２５－二羟维生素Ｄ３ 对ｐＬＧ３转染后Ｃａｃｏ－２ 细胞表达的荧光素酶活性均无显著抑制作用（Ｐ＞ ０．０５）,该作用不依赖是否存在有ｐＳＧ５－ＶＤＲ表达载体共转染。结论：１,２５－二羟维生素Ｄ３ 对报告载体ＰＧＬ２ 荧光素酶表达具有抑制作用,而对ｐＧＬ３ 则否;类似人类ＰＴＨ基因中的潜在抑制性ＶＤＲＥ存在于报告载体ｐＧＬ２,在ｐＧＬ３ 中该ＶＤＲＥ业已改变。     

A quality assessment tool to evaluate tocolytic studies

Over the past 15 years, the use of β-agonists has declined worldwide. Following the Royal College of Obstetricians and Gynaecologists guidelines in 2002, clinicians in the UK and beyond were faced with the dilemma of continuing to use β-agonists, desist from using tocolytic therapy completely or choosing to change to atosiban or calcium channel blockers (CCBs). While grade A level 1 evidence exists to show that atosiban is significantly more efficacious than placebo and significantly safer than β-agonists for the treatment of spontaneous preterm labour, the evidence for CCBs, such as nifedipine, is much less robust and no placebo-controlled trials have been performed. Published studies on nifedipine are largely investigator-led studies of small sample size, which lack sufficient power. As a result, most of the evidence has been based on meta-analyses of these studies, which look retrospectively at pooled data and are only as good as the quality of the studies included. In light of this, a tool was developed to produce a systematic review of studies on tocolytic effectiveness, which can and should be applied to all tocolytics and which considered both method- and topic-specific markers of quality. In the process of applying this tool to nifedipine, an extensive literature search identified 31 studies for a systematic review of the quality of nifedipine studies assessed by eight paired reviewers with wide experience in the subject of spontaneous preterm labour and preterm birth. Forty topic- and method-specific items of quality were assessed. The paucity of good quality studies of nifedipine used for the treatment of spontaneous preterm labour should be highlighted in meta-analyses or systematic reviews, which measure efficacy and should limit and influence the degree to which recommendations and guidelines are made on the basis of such studies.