Delayed-type hypersensitivity to a nonionic, radiopaque contrast medium

BACKGROUND: True allergic reactions to iodinated radiocontrast media are rare, and only a few well-documented cases of delayed-type hypersensitivity reactions caused by contrast media have been described. METHODS: We report a 61-year-old patient in whom percutaneous transluminal coronary angioplasty (PTCA) was performed with iopamidol, a nonionic contrast medium. Seven days later, the patient developed generalized maculopapular exanthema. Repeated patch tests with several iodinated agents were performed. RESULTS: A first patch test with iopamidol was positive. Repetition of the patch tests showed positive results to iopamidol as well as to iohexol and ioversol, two other nonionic contrast media, but not to other iodinated substances. Three months later, PTCA was repeated, and iopamidol was used again. Despite premedication, pruritic macular exanthema developed 1 day later. Whether iopamidol or trometamol -- an additive substance in the contrast medium -- was causative could not be determined, since a third set of patch tests was negative. CONCLUSIONS: Delayed-type hypersensitivity reactions to iodinated contrast media are rare. We recommend that patients with delayed exanthematous reactions undergo patch or intradermal tests with different contrast media and their additives, and that readings be performed immediately and later at days 2 and 3.     

Effects of iodinated contrast agents in MR imaging

At least two classes of mRNA for the GH receptor (GHR) and GH binding protein (GH BP) with different 5' untranslated first exons exist in the rat. One such class, the GHR1 is predominantly expressed in the liver of female rats. The hepatic expression of the GHR1 mRNA in normal and hypophsectomized rats of both sexes was studied by employing an RNase protection/solution hybridization assay. Normal females expressed 10-fold more GHR1 mRNA than males, hypophysectomy of female rats decreased the GHR1 level to that observed in male rats. Continuous GH treatment of hypophysectomized male and female rats for 6 days increased the expression of GHR1 mRNA to levels found in normal females, whereas intermittent GH treatment without effect. Bovine GH(bGH) induced the GHR1 expression in a time- and dose-dependent manner in primary cultures of adult rat hepatocytes as determined by solution hybridization. Maximal induction was achieved after 72 h of treatment with 50 ng bGH/ml medium. Female enriched expression of receptor and binding protein mRNAs raises the possibility that they participate in determining the ability of the liver to respond differently to the male and female GH secretory patterns. Our in vitro model utilizing cultures of primary adult rat hepatocytes could be used to address this issue as well as explore a hormonal interplay in regulation of GHR1 expression.     

Pulmonary hypertension. Response of vasoactive peptides to a nonionic contrast medium in patients undergoing pulmonary angiography

A 46-years-old male was admitted to our hospital because of productive cough and infiltrates on the chest roentogenogram. The patient had a history of left upper bullectomy ten years prior to the admission. The CT scan of the chest on admission showed infiltrats with cavitation in the left apex and multiple bullae in almost whole lung. Microscopical examination of smears of sputum and bronchoalveolar lavage fluid revealed acid-fast bacilli. They were identified as Mycobacterium szulgai by DNA-DNA hybridization method. The patient was treated with isoniazid, streptomycin and rifampicin. After treatment for about a month, the culture of sputum converted to negative for M. szulgai. After about three months hospitalization, the infiltrates decreased and the cavity wall became thin, and no recurrence sign has been observed after the discharge. There are a few case reports of pulmonary infection due to M. szulgai associated with bullous disease of the lung in Japan.     

Stability of iodinated contrast media in UV-laser irradiation and toxicity of the photoproducts]

BACKGROUND: While elevated levels of serum creatinine have been shown to be a risk factor for diminished survival after stroke, it is unknown how renal replacement therapy may affect the outcome. METHODS: Strokes occurring in 26 consecutive patients undergoing hemodialysis at our institution were reviewed and clinical and laboratory variables and outcome were compared with those of patients who had a stroke but had normal renal function. RESULTS: Twenty-four strokes in the patients undergoing hemodialysis were ischemic while only 2 were hemorrhagic. Virtually all the patients had hypertension, half had diabetes mellitus, and most had some prior evidence of cardiovascular disease at the time of their stroke. Fifty percent of the patients undergoing hemodialysis had a good outcome (defined as being discharged home) while the remainder had a poor outcome (defined as dying or being discharged to a nursing facility). The combined presence of hypertension and coronary artery disease had a sensitivity of 91.2% for identifying patients with a poor outcome, while male sex, the presence of coronary artery disease, and the combined presence of hypertension, coronary artery disease, and/or congestive heart failure had sensitivities greater than 80% but low specificity. The outcome of patients undergoing hemodialysis was comparable with that of a control group of patients who had a stroke but had normal renal function, although the length of hospital stay was greater (mean [+/-SEM] 29.8+/-6.4 days vs 12.7+/-1.1 days, respectively; P<.01). CONCLUSIONS: Hospitalized patients undergoing hemodialysis in whom stroke occurs appear to have as good an outcome as that of patients with normal renal function, although they are hospitalized longer. In addition, certain clinical variables seem to be associated with a worse outcome. Aggressive measures to prevent and treat stroke seem as warranted for patients undergoing hemodialysis as for patients with normal renal function, although interventions to reduce the length of hospital stay are needed.     

Structural changes in the renal proximal tubular cells induced by iodinated contrast media

Bilateral femurs of 12-week-old female Sprague-Dawley rats were fractured, and the fractured femurs were harvested 36 h, 3, 7, 10, and 14 days after the fracture. Localization of cell proliferation in the fracture calluses was investigated using immunohistochemistry with antiproliferating cell nuclear antigen (PCNA) monoclonal antibodies. Thirty-six hours after the fracture, many PCNA-positive cells were observed in the whole callus. The change was not limited to mesenchymal cells at the fracture site where the inflammatory reaction had occurred, but extended in the periosteum along almost the entire femoral diaphysis where intramembranous ossification was initiated. On day 3, periosteal cells or premature osteoblasts in the newly formed trabecular bone during intramembranous ossification still displayed intense staining. On day 7, many premature chondrocytes and proliferating chondrocytes were PCNA positive. Endochondral ossification appeared on days 10 and 14, and the premature osteoblasts and endothelial cells in the endochondral ossification front were stained with anti-PCNA antibodies. Quantification of PCNA-positive cells was carried out using an image analysis computer system, obtaining a PCNA score for each cellular event. The highest score was observed in the periosteum early after the fracture near the fracture site. Immunohistochemistry using anti-PCNA antibodies showed that the distribution of proliferating cells and the degree of cell proliferation varied according to the time lag after the fracture, suggesting the existence of local regulatory factors such as growth factors, and that significant cell proliferation was observed at the beginning of each cellular event.     

含离子液体介质中铜纳米粒子的制备及其影响因素

在含有离子液体[BMIm]PF6、[PMIm]PF6和[C6MIm]PF6的介质中,通过还原Cu2+制备铜纳米粒子.通过TEM和XRD分析,对比研究了Cu2+浓度、还原剂种类以及离子液体[BMIm]PF6、[PMIm]PF6和[C6MIm]PF6对所制备的铜纳米粒子的粒径和形貌的影响.结果表明:Cu2+浓度对铜纳米粒子的粒径和形貌没有明显的影响;离子液体的类型对铜纳米粒子的粒径也没有明显的影响,但对形貌有一定的影响;还原剂对铜纳米粒子的粒径及形貌影响较大.     

Responses of tumor cell pseudopod protrusion to changes in medium osmolality

The potential involvement of osmotically generated force in protrusion of tumor cell pseudopods was examined during a micropipette assay. Experiments were performed on single A2058 melanoma cells activated by a micropipette filled with soluble type IV collagen. Previous observations suggested that tumor cell pseudopod protrusion induced by type IV collagen took place in distinct, separable phases: an initial bleb (first phase) caused by localized Ca2+-activated actin filament severing resulting in an osmotic flux followed by an extension with an irregular shape (second phase) which required G protein-mediated actin polymerization (Dong et al., 1994, Microvasc. Res., 47:55-67). Presently we studied cell pseudopod protrusion in response to the changes in chemoattractant osmolality. Reduction of attractant osmolality by 20-25% from its baseline value (297 mmol/ kg) resulted in an increase in pseudopod length by 50% apparent in the initial phase. Increases in attractant osmolality by 25-30% from the baseline value arrested pseudopod protrusion significantly during both initial and later phases. Using a dual-pipette method, such osmotic influence on the cell pseudopod protrusion was shown to be only a local effect in a small region where the cell surface was stimulated by the micropipette. While forces derived from actin polymerization and osmotic pressure have been proposed to cause protrusion in general, our results suggested that osmotically generated force is more apparent in the initial phase of the pseudopod formation.     

炼焦煤堆密度的影响因素分析

对炼焦过程中煤料堆密度的影响因素进行分析,对宝钢,用过的107种原料煤的粒度分布进行分析后证明均满足Rosin-Rammler分布。通过大量试验,研究水分、中位径、分布参数这三种备煤阶段可控制因素对装炉煤堆密度的影响,并对影响因素进行方差分析,结果表明,这三种因素对于装炉煤堆密度影响显著。设计17组试验,对试验结果采用多项式逐步回归法得到堆密度预测模型,经验证,该模型准确性高。对顶装煤炼焦工艺,备煤阶段应该控制装炉煤水分在不发生逸散情况下尽量低,在保证配煤均匀的前提下煤料细度要适度低并且不要破碎过细,使装炉煤中位径保持较高水平。     

Effects of iodinated contrast media on pulmonary airway resistance in anesthetized guinea pigs

RATIONALE AND OBJECTIVES: Bronchospasm is occasionally observed following iodinated X-ray contrast medium administration. We performed an in vivo study in guinea pigs to investigate the effects of a number of iodinated contrast media on pulmonary airway resistance and the mechanisms underlying the potential bronchoconstrictor effect. METHODS: The contrast media studied were the pharmaceutical formulations of iomeprol (400 mg I/ml), iopamidol (370 mg I/ml), and iohexol (350 mg I/ml), which are nonionic, triiodinated contrast media; diatrizoate (370 mg I/ml), an ionic, triiodinated contrast medium; iotrolan (300 mg I/ml), a nonionic, hexaiodinated contrast medium; and iocarmate (280 mg I/ml) and ioxaglate (320 mg I/ml), which are both hexaiodinated and ionic contrast media. Each contrast medium was administered intravenously at 2 g I/kg. Changes in pulmonary airway resistance were evaluated by measuring intratracheal pressure at the moment of maximum insufflation, or maximal insufflation pressure (MIP), in anesthetized guinea pigs submitted to forced ventilation. RESULTS: All contrast media except ioxaglate caused mean increases of MIP of no more than 20%. By contrast, ioxaglate caused a marked bronchoconstrictor effect, increasing MIP by 242% +/- 46%. Of the drugs tested for antagonistic action on this increase in MIP, salbutamol inhibited almost completely the increase in MIP for the first 40 min posttreatment. Similarly, lysine acetylsalicylate and indomethacin consistently reduced MIP after contrast media administration to levels only 30% and 14% above those of baseline precontrast media, respectively. Promethazine had only a minor inhibitory effect, and the response to prednisolone varied. CONCLUSION: There was no apparent relationship between the size of the increase in airway resistance and the charge or molecular weight of the contrast agent molecule or the pharmaceutical formulation. The increase induced by ioxaglate must be attributed to inherent molecular toxicity mediated through a direct action on the production of bradykinin and/or the prostanoid products of the cyclooxygenase pathway, rather than through a direct action on the release of histamine.     

The haemodynamic effects of iodinated water soluble radiographic contrast media: a review

All classes of iodinated water-soluble radiographic contrast media (RCM) are vasoactive with the iso-osmolar dimers inducing the least changes in the vascular tone. The mechanisms responsible for RCM-induced changes in the vascular tone are not fully understood and could be multifactorial. A direct effect on the vascular smooth muscle cells causing alterations in the ion exchanges across the cell membrane is thought to be an important factor in RCM-induced vasodilatation. The release of the endogenous vasoactive mediators adenosine and endothelin may also play a crucial role in the haemodynamic effects of RCM particularly in the kidney. In addition, the effects of RCM on blood rheology can cause a reduction in the blood flow in the microcirculation. The purpose of this review is to discuss the pathophysiology of the haemodynamic effects of RCM and to offer some insight into the biology of the endothelium and vascular smooth muscle cells as well as the pharmacology of the important vasoactive mediators endothelin and adenosine.     

焦炭硫分影响因素分析

简要归纳了国内目前焦炭硫分预测方法,指出了不足。通过32个单种煤硫分形态与焦炭硫分关系研究,分析了硫分形态对焦炭硫分的影响;通过分析炼焦过程炼焦煤硫分变化,提出传统室式炼焦过程脱硫反应和固硫反应并存,煤气中H2具有脱硫功能,灰中CaO和MgO是固硫剂;60个样品试验数据的回归分析结果表明,煤的全硫和灰中(CaO+MgO)含量是影响焦炭硫分的主要因素。     

Aspirin and fraxiparine in the prevention of laser induced thrombosis in the presence of iodinated contrast media

The purpose of this study was to investigate the thromboembolic properties of ionic and nonionic contrast media in rats pretreated with aspirin and/or fraxiparine using an experimental model of laser induced thrombosis in the mesenteric microvessels of 17 groups of five male Wistar rats each. Two ionic (ioxaglate and diatrizoate) and two nonionic contrast media (iopamidol and iohexol), alone or associated with antithrombotic drugs (aspirin and/or fraxiparine) were studied. To evaluate the effects of these substances in this model, the number of laser beams needed to induce platelet thrombus formation, the number of emboli detached from the thrombus and the duration of embolization were quantified. Platelet aggregation induced by ADP, induced hemorrhagic time (IHT) and haemoglobin loss level were also determined. Both contrast media injected at 3 ml/kg caused a significant increase in the number of emboli and the duration of embolization (p<0.05). Pretreatment with aspirin and/or fraxiparine in the presence of ionic contrast media showed antithrombotic activities equal to those obtained when they were tested alone (p<0.05), while in the presence of nonionic contrast media, these drugs only neutralised the prothrombotic effects. There were no differences with the NaCl treated group (p>0.05). The ionic contrast media, and to a lesser extent the nonionic contrast medium: iohexol, inhibited platelet aggregation, while iopamidol behaved as an activator. The antithrombotic drugs tested in this study prevent the prothrombotic activities of contrast media therefore suggesting their use before radiographic procedures.     

Comparison of cardiovascular response to ionic and nonionic magnetic resonance susceptibility contrast agents

RATIONALE AND OBJECTIVES: Bolus injection of magnetic resonance (MR) contrast media has been used in recent years to exploit the diagnostic advantage of newer fast MR imaging sequences. The bolus effects of three equimolar dosages of ionic and nonionic magnetic susceptibility contrast agents on several cardiovascular functional parameters are investigated in normal rats and in rats subjected to acute myocardial infarction. These results are related to the osmolalities of the injected solutions. METHODS: Four groups of rats were examined (n = 10 rats per group). Twenty normal rats were studied. Acute myocardial infarction was produced by ligating the anterior branch of the left coronary artery for 2 hours in another 20 rats. Sequential equimolar doses of 0.1, 0.3, and 0.5 mmol/kg of ionic dysprosium diethylenetriamine pentaacetic acid dimeglumine ([NMG]2DyDTPA) or nonionic dysporosium diethylenetriamine pentaacetic acid-bis-methylamide (DyDTPA-BMA) (sprodiamide injection) were administered intravenously into the left jugular vein as a bolus. Hemodynamic parameters (heart rate, left ventricular pressures, rate of rise of left ventricular pressure [+/- dP/dt], and electrocardiogram as well as central and peripheral pressures) were continuously monitored for 15 minutes after each dose. Left ventricular developed pressure and rate pressure product, as indicators of myocardial oxygen consumption, were calculated. Osmolalities of the injected solutions were determined from freezing-point depression and correlated with the observed hemodynamic alterations. RESULTS: Bolus administration of 0.1, 0.3, and 0.5 mmol/kg DyDTPA-BMA produced no significant effect on the various hemodynamic parameters. (NMG)2DyDTPA caused dose-dependent attenuations in heart rate, left ventricular pressures, +/- dP/dt, rate pressure product and arterial blood pressures in both normal and infarcted rats. The magnitude of the response was dose dependent. Significant correlations were observed between osmolality and peak change of hemodynamic variables (r values between 0.99-1.00) after the administration of (NMG)2DyDTPA, but not after the injection of DyDTPA-BMA. CONCLUSIONS: Bolus administration of (NMG)2DyDTPA resulted in transient negative inotropic and chronotropic effects and hypotension in both healthy and infarcted animals. DyDTPA-BMA, administered as a bolus even at high doses, caused no appreciable hemodynamic alterations.     

影响加压送风系统运行效果的因素分析

在调查部分在用高层建筑疏散通道上防火门平时使用情况的基础上,分析了在火灾时其对加压送风防烟系统运行效果的影响,认为疏散通道上防火门平时的开闭状况对加压送风防烟系统运行效果会产生较大影响。     

冷轧带钢边部减薄及其影响因素分析

冷轧带钢生产中普遍存在的边部减薄现象,直接影响切边量大小,降低了成材率。为了减小边部减薄,对其形成机理进行了详细论述,并利用非线性有限元软件MARC,建立了模拟四辊冷轧机轧制过程的弹塑性有限元仿真模型。将轧制力模拟结果与实测值对比表明该模型是精确可靠的。利用此模型,系统分析了压下率、摩擦因数以及带钢入口厚度、入口宽度等因素对边部减薄的影响规律。分析结果表明,随着压下率、摩擦因数、带钢入口厚度的增大,边部减薄随之加剧,随着带钢入口宽度的增大,边部减薄先增大后减小。     

Precipitation of a cholegraphic contrast medium in a dog

Following intravenous injection of medium for cholegraphy, calcium salt was precipitated in the tubules of rats and a 'gallstone' containing contrast medium developed in a dog. A review is given of biotransformation of contrast media in the biliary and urinary tracts.     

Effect of contrast medium on corpus cavernosum smooth muscle

OBJECTIVE: To study the molecular basis of complete androgen insensitivity syndrome (AIS). STUDY DESIGN: The coding region of the human androgen receptor (hAR) gene in two women with AIS was amplified with polymerase chain reaction using 12 pairs of oligonucleotide primers and then sequenced with a dye terminator method. RESULTS: Both patients had mutation in exon E of the androgen-binding domain. In one patient, codon 732 GAC (aspartic acid) was changed to ACC (asparagine), and her CAG polyglutamine tract had 27 repeats. In the other patient, codon 765 GCC (alanine) was changed to ACC (threonine), and her CAG polyglutamine tract in exon A had 19 repeats. CONCLUSION: Except for CAG polyglutamine polymorphism, these two missense mutations were the only differences detected in the coding region of the hAR gene. Both mutations involved the CpG sequence, which has been regarded as a mutation hotspot. To the best of our knowledge, these two mutations have not been observed before in Chinese women. Elucidation of the molecular defects of AIS patients would be very helpful for genetic counseling and prenatal diagnosis.     

四流中间包流场影响因素分析与优化

采用正交试验法建立1:2.5水力学模型,选取L12(22×31)混合正交表设计12组水模试验方案,对水模试验结果进行极差分析,分析挡墙类型、挡墙导孔孔径和挡墙导孔倾角对中间包流场特性的影响大小,并找出合理的控流装置配置.结果表明,挡墙导流孔倾角对中间包流场特性影响最大,其次是导流孔孔径和挡墙类型.采用Y型挡墙,挡墙导孔...     

Intravascular electrically induced thrombosis in the dog. Thrombus detection by ionic and nonionic contrast media

Proliferative activity of bone marrow clonogenic stromal precursor cells was studied by using the thymidine "suicide" method in vitro. Crude bone marrow stromal clonogenic cells failed to proliferate in vivo. But 24 hours after the explantation they entered the S-period and formed colonies of fibroblasts in monolayer cultures. 39+/-4% of these clonogenic cells were subject to thymidine "suicide". It follows that, in difference from cells-precursors in the crude bone marrow, clonogenic stromal cells were actively proliferating in monolayer cultures.