Relative contributions of the nucleus raphe magnus and adjacent medullary reticular formation to the inhibition by stimulation in the periaqueductal gray of a spinal nociceptive reflex in the pentobarbital-anesthetized rat

Ammonia intoxication decreases the hyperpolarizing action of postsynaptic inhibition. This study examines the metabolic state of the spinal cord during this effect of ammonia intoxication on spinal motoneurons. ATP, ADP, AMP, the adenylate energy charge, glucose, PCr, pyruvate, alpha-ketoglutarate and glutamate were unchanged during the effect of ammonia on the hyperpolarizing action of postsynaptic inhibition. NH4+, glutamine and lactate were increased. Ammonia intoxication affected postsynaptic inhibition without changes of the resting membrane potential, the neuron input resistance, the action potential and EPSPs. The encephalopathy caused by ammonia intoxication is known to occur without an alteration of the tissue energy state. The effect of ammonia intoxication on postsynaptic inhibition can be considered as a cause of the encephalopathy because postsynaptic inhibition is altered without a change of the tissue energy state, the resting membrane potential, the whole neuron resistance, the action potential and EPSPs.     

Inhibition of nucleotide excision repair and sensitisation of cells to DNA cross-linking anticancer drugs by F 11782, a novel fluorinated epipodophylloid

F 11782, or 2',3'-bis-pentafluorophenoxyacetyl-4',6'-ethylidene-beta-D-glucoside of 4'-phosphate-4'-dimethylepipodophyllotoxin 2-N-methyl glucamine salt, a novel dual catalytic inhibitor of topoisomerases I and II, was identified as a potent inhibitor of nucleotide excision repair (NER) by screening procedures using the in vitro 3D (DNA damage detection) assay. F 11782 was then shown predominantly to inhibit the incision rather than the repair synthesis step, using two new methodologies derived from this 3D assay, effectively ruling out any inhibition of polymerases delta/var epsilon. Moreover, data from two other in vitro assays showed an absence of any effect of F 11782 on: (i) the DNA damage binding of the XPA-RPA complex, and (ii) on SV40 large T-antigen helicase activity. Therefore, the inhibitory activity of F 11782 on NER may involve an inhibition of the ERCC1-XPF or XPG endonuclease activity. Moreover, inhibition of DNA repair by F 11782 was confirmed in human A549 cells by monitoring unscheduled DNA synthesis following mechlorethamine treatment. Such an inhibition provides an explanation for the highly synergistic cytotoxicity observed against cultured A549 lung tumour cells, when F 11782 was combined with cross-linking agents, such as cisplatin or mitomycin C. These results emphasise the unique mode of action of this novel molecule in inhibiting NER and provide a basis for its evaluation in clinical trials in combination with DNA cross-linking agents.     

钩端螺旋体病人血清抗体的SPA-ELISA检测法

用酶标葡萄球菌A 蛋白作ELISA 检测临床确诊、显凝试验为阳性的钩端螺旋体病人血清59份,同时用40份健康人血清与酶标抗体作ELISA进行比较。两种方法都有较高的敏感性和特异性,而酶标葡萄球菌A 蛋白具有制备简单,标记步骤简便,比较稳定和易被推广等优点,可替代酶标抗体在ELISA中应用。     

Effects of morphine on spontaneous multiple-unit activity: possible relation to mechanisms of analgesia and reward.

The effects of morphine (15 mg/kg) on multiple-unit activity in the awake rat were investigated at brain sites previously characterized by their ability to support stimulation-produced analgesia (SPA) and intracranial self-stimulation (ICSS). Of the SPA and SPA + ICSS sites, most of which were located in the periaqueductal gray matter, 91% showed increased multiple-unit activity after morphine administration (median increase = 80%). In contrast, only 50% of the ICSS-only sites, most of which were located in the lateral hypothalamus, and only 29% of sites supporting neither behavior showed this effect. All increases in multiple-unit activity were at least partly reversed by naloxone (1 mg/kg). Latencies to their onset and to analgesia measured by the tail-flick method were significantly correlated. A significant negative correlation was found between ICSS current thresholds and increases in multiple-unit activity after morphine at ICSS-only sites. These data lend further support to the suggestion that morphine exerts its analgesic action by activating an endogenous analgesic system and that the periaqueductal gray constitutes an important part of such a system. Furthermore, it is suggested that morphine's excitatory effect at self-stimulation loci may reflect its rewarding properties.     

Fertilization potential of human sperm is correlated with endogenous platelet-activating factor content

Purpose: Platelet-activating factor (PAF) is a potent signaling phospholipid that is found in mammalian sperm and has a positive correlation with fertility. Whereas PAF is present in human sperm, there are no relational reports on its content and the cells fertilization potential. Therefore, the study objective was to determine if PAF content in capacitated-induced sperm is related to fertilization potential as determined by the sperm penetration assay (SPA). Methods: Endogenous sperm lipids were measured for PAF content by a specific radioimmunoassay following insemination of zona pellucida-free hamster ova. Data were analyzed by regression analysis and Student's t test. Results: Regression analysis revealed a positive and significant relation (R ² = 0.806; P < 0.05) between PAF content in human sperm and SPA outcome (pass: 5.0; fail: <5.0, penetrations/ova). Patients that passed (22.61 ± 5.21 picomoles/10⁶) the SPA had significantly (P < 0.01) higher PAF levels in their sperm than patients that failed (12.91 ± 1.76 picomoles/10⁶ cells) the test. Conclusions: PAF content in capacitated-induced sperm has a significant and positive relationship with fertilization potential. Fertilization potential may be predicted by measuring PAF levels in capacitation-induced human sperm. Determining PAF content in capacitated human sperm may be a beneficial diagnostic tool for the infertility specialist.     

Automated radiosynthesis of [18F]SPA‐RQ for imaging human brain NK1 receptors with PET

[¹⁸F]SPA‐RQ is an effective radioligand for imaging brain neurokinin type‐1 (NK₁) receptors in clinical research and drug discovery with positron emission tomography. For the automated regular production of [¹⁸F]SPA‐RQ for clinical use in the USA under an IND we chose to use a modified commercial synthesis module (TRACERlab FX_F‐N; GE Medical Systems) with an auxiliary custom‐made robotic cooling–heating reactor, after evaluating several alternative radiosynthesis conditions. The automated radiosynthesis and its quality control are described here. [¹⁸F]SPA‐RQ was regularly obtained within 150 min from the start of radiosynthesis in high radiochemical purity (>99%) and chemical purity and with an overall decay‐corrected radiochemical yield of 15±2% (mean±S.D.; n=10) from cyclotron‐produced [¹⁸F]fluoride ion. The specific radioactivity of [¹⁸F]SPA‐RQ at the end of synthesis ranged from 644 to 2140 mCi/µmol (23.8–79.2 GBq/µmol). Copyright © 2005 John Wiley & Sons, Ltd.     

Contribution of alpha4beta1 integrin to the antiallergic effect of levocabastine

Levocabastine is an antiallergic drug acting as a histamine H1-receptor antagonist. In allergic conjunctivitis (AC), it may also antagonize up-regulation of the intercellular adhesion molecule-1 (ICAM-1) expressed on epithelial conjunctival cells. However, little is known about its effects on eosinophils, important effector cells in AC. The adhesion molecule integrin alpha(4)beta(1) is expressed in eosinophils; it interacts with the vascular cell adhesion molecule-1 (VCAM-1) and fibronectin (FN) in vascular endothelial cells and contributes to eosinophil activation and infiltration in AC. This study provides evidence that in a scintillation proximity assay levocabastine (IC(50) 406 microM), but not the first-generation antihistamine chlorpheniramine, displaced (125)I-FN binding to human integrin alpha(4)beta(1) and, in flow cytometry analysis, levocabastine antagonized the binding of a primary antibody to integrin alpha(4) expressed on the Jurkat cell surface. Levocabastine, but not chlorpheniramine, binds the alpha(4)beta(1) integrin and prevents eosinophil adhesion to VCAM-1, FN or human umbilical vascular endothelial cells (HUVEC) in vitro. Similarly, levocabastine affects alpha(L)beta(2)/ICAM-1-mediated adhesion of Jurkat cells. In a model of AC levocabastine eye drops reduced the clinical aspects of the late-phase reaction and the conjunctival expression of alpha(4)beta(1) integrin by reducing infiltrated eosinophils. We propose that blockade of integrin-mediated cell adhesion might be a target of the antiallergic action of levocabastine and may play a role in preventing eosinophil adhesion and infiltration in AC.     

探讨外周血IgM、TNF-α、SPA及IL-10表达在院内获得性肺炎患者治疗及预后中的评价影响

目的探讨外周血肺炎支原体抗体(mycoplasma pneumoniae Immunoglobulin M,MP-IgM)、肿瘤坏死因子(tumor necrosis factor-α,TNF-α)、肺表面活性蛋白A(pulmonary surfactant protein A,SPA)及白细胞介素-10(interleukin 10,IL-10)表达在院内获得性肺炎患者治疗及预后中的评价意义。方法选取2016年1月至2017年12月本院确诊的100例院内获得性肺炎患者为观察组给予对症治疗,选取同期健康体检患者50例为对照组。分别检测患者外周静脉血中MP-IgM、TNF-α、SPA及IL-10表达水平。结果与对照组相比,观察组患者血清内TNF-α、SPA及IL-10表达水平显著升高,血清MP-IgM呈明显阳性,随着疾病程度的加重,表现更为明显(P<0.05);观察组血清内TNF-α、SPA及IL-10表达水平治疗后显著降低,血清MP-IgM阳性减少(P<0.05)。院内获得性肺炎患者体内TNF-α、SPA及IL-10含量,MP-IgM阳性率与疾病严重程度存在显著的正性相关关系,P<0.05。经ROC分析可知,MP-IgM、TNF-α、SPA及IL-10这4项生物学标志物并联试验灵敏度为92.00%,串联试验特异性为100.00%,显著大于各单项生物学标志物检测(P<0.05)。结论外周静脉血中MP-IgM、TNF-α、SPA及IL-10表达在院内获得性肺炎患者体内异常升高,给予药物治疗后患者病情缓解,外周静脉血中MP-IgM、TNF-α、SPA及IL-10变化有利于监测在院内获得性肺炎患者的病情程度和治疗,值得推广研究。     

Heparin-induced coagulopathy associated with staphylococcal protein A immunoadsorption treatment columns: an in vitro and in vivo analysis

BACKGROUND: The staphylococcal protein A (SPA) column used to treat refractory autoimmune and alloimmune thrombocytopenia and rheumatoid arthritis patients is primed with heparin to prevent possible fibrin clot formation when the patient's plasma is passed through the column. A BMT patient with refractory alloimmune thrombocytopenia had prolonged activated partial thromboplastin times (aPTTs) at the end of SPA column treatments. This observation led to in vivo and in vitro analysis of the kinetics of heparin elution from the SPA column. STUDY DESIGN AND METHODS: Two patients with refractory rheumatoid arthritis, who were treated on five occasions with the SPA column (as a part of a national trial) primed with 5000 U of heparin, were monitored for aPTT and heparin in their plasma. In addition, two in vitro analyses were performed with FFP for heparin elution from the SPA column. RESULTS: The in vivo studies showed the presence of 0.3 to 1.5 U per mL of heparin in patients' plasma at the end of the SPA column treatments that corresponded with the prolonged aPTTs. The in vitro studies showed that 82 to 85 percent heparin (approx. 4400 U) was eluted from the SPA column during rather than before the procedure. CONCLUSION: Patients undergoing SPA column treatments, especially those with thrombocytopenia, may be at increased risk of bleeding as a result of the presence of a significant amount of heparin in their circulation during the entire period of SPA column treatment.     

Electrophysiologic evidence for a direct connection between the periaqueductal gray and the nucleus gigantocellularis in the rat

Although stimulation of the periaqueductal gray (PAG) and microinjection of opiates or opioids into the PAG was reported to affect the activity of nucleus gigantocellularis (NGC) neurons, it is not known whether a direct pathway exists between these brain regions. The purpose of this investigation was to electrophysiologically test this possibility by attempting to antidromically activate PAG neurons from the NGC. Seventy neurons in the PAG of urethane-anesthetized rats were activated by electrical stimulation in the NGC and classified on the basis of the antidromicity criteria of constant latency, high following frequency, and collision. Of these neurons, 50 (71%) were classified as being transsynaptically activated, and 20 (29%) were classified as being antidromically activated. Ten neurons demonstrated collision between spontaneous action potentials and stimulation-evoked action potentials. Although most of the responses could not be tested with all criteria, the data support the existence of a monosynaptic pathway from the PAG to the NGC.