Digital subtraction rotational angiography for aneurysms of the intracranial anterior circulation: injection method and optimization

PURPOSE: To optimize parameters of rotational angiography for examination of the internal carotid circulation; to compare rotational angiography with standard digital subtraction angiography (DSA) in the evaluation of aneurysms of the intracranial internal carotid circulation; and to determine tolerance and safety limits of prolonged internal carotid injection angiography. METHODS: Rotational angiograms were obtained during injection of the internal carotid circulation as part of the clinical angiographic evaluation of aneurysms in 41 patients. Injection rates, X-ray delays, and fields of view were studied retrospectively. Findings at rotational angiography and standard DSA were compared. Nonionic contrast material was injected over 6 seconds, and patients were studied before and after prolonged injection angiography by physical and laboratory examination, including measurement of blood pressure, pulse, and intracranial pressure. RESULTS: Vascular conspicuity was equivalent at carotid injection rates of 4 and 5 mL/s delivered over 6 seconds. At 3 mL/s, more image manipulation was required to see small vascular structures. One-second X-ray delay combined with 6-second injection duration provided the best arterial depiction of intracranial vessels from start to end of rotational angiography. Maximal rotational resolution was with a 17-cm field of view. Identification of aneurysms and small vessels was equivalent at all injection rates. Aneurysm detection was equivalent with rotational angiography and DSA. In 9 of 31 aneurysms, the neck was defined more clearly with rotational angiography than with DSA, compared with 2 of 31 that were seen better with DSA. Aneurysms of the intracranial internal carotid circulation were seen with rotational angiography and not DSA in 12 of 41 cases. No change was noted in clinical or laboratory findings. CONCLUSION: Rotational angiography provided better definition of the aneurysmal neck and greater clarity of aneurysms than did DSA; it also improved the level of confidence in predicting the presence or absence of aneurysms, especially in the anterior communicating artery; however, in our small series it did not significantly increase the detection of aneurysms. Prolonged injection angiography was well tolerated in all patients.     

Spatial location is critical for conditioning place preference with visual but not tactile stimuli.

The roles of visual, tactile, and spatial location cues were studied in 6 conditioned place preference (CPP) experiments with ethanol (2 g/kg) in mice (of the DBA/2J strain). Visual cues were effective conditioned stimuli (CSs) when consistently presented in the same spatial location, but not when the same cue was presented in two different locations during training. In contrast, tactile CSs were effective regardless of spatial location during training. Moreover, spatial location controlled CPP expression when visual cues were used but not when tactile cues were used. However, spatial location per se was not an effective CS. These studies suggest that CPP conditioned to tactile cues is mediated by brain systems different from those mediating CPP conditioned to visual-spatial cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis,characterization, and curing of o-and p-chlorophenol-furfural resins

Polycondensation of furfural, respectively, with o- and p-chlorophenols has been carried out under various reaction conditions. All the resin samples have been characterized by spectral studies, viscometric measurement and by the estimation of the number-average molecular weight. Thermogravimetric analysis (TGA) of selected resin samples has been carried out. The kinetics of curing reaction of selected resin samples has been investigated by differential scanning calorimetry (DSC). The properties of the glass laminates prepared using each of the two types of resins showed that the latter are much less suitable than phenol-furfural resin as matrices for the fabrication of laminates.     

Effects of suramin-related and other clinically therapeutic polyanions on protein kinase C activity

The mechanism of the antineoplastic effects of suramin may involve interference with signal transduction, but in general is not well understood. We examined several polyanions to determine their effects on the kinase activity of the protein kinase C (PKC) beta1 and other PKC isoforms. Similar to suramin, a phosphorothioate oligodeoxynucleotide 28-mer homopolymer of cytidine (SdC28) inhibited the phosphatidylserine and Ca2+-dependent phosphorylation of an epidermal growth factor receptor octapeptide substrate. The inhibition by suramin was mixed competitive/noncompetitive with respect to ATP, but uncompetitive with respect to substrate. In contrast, the inhibition by SdC28 was competitive with respect to substrate (Ki = 5.4 microM) and not competitive with respect to ATP. The PKC alpha and beta1 isoforms were inhibited to the same extent with SdC28, while PKC epsilon was not inhibited. SdC28, in the absence of lipid cofactor, stimulated substrate phosphorylation, and in the absence of substrate induced PKC beta1 autophosphorylation. Similar behavior was seen with another polyanion, the polysulfated carbohydrate pentosan polysulfate (polyxylyl hydrogen sulfate). H4, a bis-naphthalene disulfonate tetraanion structurally related to suramin, also inhibited kinase activity but was not competitive with respect to ATP. Dianions closely related to H4 failed to inhibit PKC beta1, suggesting that multiple (>2) negative charges are required. The interactions of polyanions with PKC are complex, and are dependent on the molecular structure of the polyanion, the presence of cofactors, and the PKC isoform.     

Differential scanning calorimetric investigation of polymerisation of epoxy resin based on phenolphthalein with phthalic anhydride

Polymerisation of phenolphthalein-based epoxy resin with phthalic anhydride has been investigated by differential scanning calorimetry. The overall polymerisation kinetics were found to be independent of the concentration of phthalic anhydride and scan rate. The polymerisation was found to follow a simple Arrhenius-type temperature dependence up to about 80% completion.     

Carboxymethylation of Cassia tora gum

The preparation of carboxymethyl (CM)–Cassia tora gum (CTG) with monochloroacetic acid and sodium hydroxide was investigated under different reaction conditions. The carboxymethylation reaction was studied with respect to the degree of substitution of CM–CTG. The variables studied were the concentration of reactants, methanol–water ratio (solvent), reaction time, and reaction temperature. Carboxymethylation of CTG increased its solubility in cold water and the stability of its paste to microorganisms. Regardless of the degree of substitution of these products, their aqueous solutions were characterized by non‐Newtonian pseudoplastic behavior. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3216–3219, 2003     

Future directions for resuscitation research. III. External cardiopulmonary resuscitation advanced life support

This discussion about advanced cardiac life support (ACLS) reflects disappointment with the over 50% of out-of-hospital cardiopulmonary resuscitation (CPR) attempts that fail to achieve restoration of spontaneous circulation (ROSC). Hospital discharge rates are equally poor for in-hospital CPR attempts outside special care units. Early bystander CPR and early defibrillation (manual, semi-automatic or automatic) are the most effective methods for achieving ROSC from ventricular fibrillation (VF). Automated external defibrillation (AED), which is effective in the hands of first responders in the out-of-hospital setting, should also be used and evaluated in hospitals, inside and outside of special care units. The first countershock is most important. Biphasic waveforms seem to have advantages over monophasic ones. Tracheal intubation has obvious efficacy when the airway is threatened. Scientific documentation of specific types, doses, and timing of drug treatments (epinephrine, bicarbonate, lidocaine, bretylium) are weak. Clinical trials have failed so far to document anything statistically but a breakthrough effect. Interactions between catecholamines and buffers need further exploration. A major cause of unsuccessful attempts at ROSC is the underlying disease, which present ACLS guidelines do not consider adequately. Early thrombolysis and early coronary revascularization procedures should also be considered for selected victims of sudden cardiac death. Emergency cardiopulmonary bypass (CPB) could be a breakthrough measure, but cannot be initiated rapidly enough in the field due to technical limitations. Open-chest CPR by ambulance physicians deserves further trials. In searches for causes of VF, neurocardiology gives clues for new directions. Fibrillation and defibrillation thresholds are influenced by the peripheral sympathetic and parasympathetic nervous systems and impulses from the frontal cerebral cortex. CPR for cardiac arrest of the mother in advanced pregnancy requires modifications and outcome data. Until more recognizable critical factors for ROSC are identified, titrated sequencing of ACLS measures, based on physiologic rationale and sound judgement, rather than rigid standards, gives the best chance for achieving survival with good cerebral function.     

Compact planar multiband antenna for GPS, DCS, 2.4/5.8 GHz WLAN applications

A compact single-feed multiband planar antenna configuration suitable for GPS, DCS, 2.4/5.8 GHz WLAN applications is presented. The antenna has dimensions 38/spl times/3/spl times/1.6 mm and offers good radiation and reflection characteristics in the above frequency bands. The antenna has a simple geometry and can be easily fed using a 50 /spl Omega/ coaxial probe.