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Abstract Background The over-expression of transforming growth factor β-1(TGF-β1) has been reported to cause hydrocephalus, glia activation, and vascular amyloidβ (Aβ) deposition in mouse brains. Since these phenomena partially mimic the cerebral amyloid angiopathy (CAA) concomitant to Alzheimer's disease, the findings in TGF-β1 over-expressing mice prompted the hypothesis that CAA could be caused or enhanced by the abnormal production of TGF-β1. This idea was in accordance with the view that chronic inflammation contributes to Alzheimer's disease, and drew attention to the therapeutic potential of anti-inflammatory drugs for the treatment of Aβ-elicited CAA. We thus studied the effect of anti-inflammatory drug administration in TGF-β1-induced pathology. Methods Two-month-old TGF-β1 mice and littermate controls were orally administered pioglitazone, a peroxisome proliferator-activated receptor-γ agonist, or ibuprofen, a non steroidal anti-inflammatory agent, for two months. Glia activation was assessed by immunohistochemistry and western blot analysis; Aβ precursor protein (APP) by western blot analysis; Aβ deposition by immunohistochemistry, thioflavin-S staining and ELISA; and hydrocephalus by measurements of ventricle size on autoradiographies of brain sections. Results are expressed as means ± SD. Data comparisons were carried with the Student's T test when two groups were compared, or ANOVA analysis when more than three groups were analyzed. Results Animals displayed glia activation, hydrocephalus and a robust thioflavin-S-positive vascular deposition. Unexpectedly, these deposits contained no Aβ or serum amyloid P component, a common constituent of amyloid deposits. The thioflavin-S-positive material thus remains to be identified. Pioglitazone decreased glia activation and basal levels of Aβ42- with no change in APP contents – while it increased hydrocephalus, and had no effect on the thioflavin-S deposits. Ibuprofen mimicked the reduction of glia activation caused by pioglitazone and the lack of effect on the thioflavin-S-labeled deposits. Conclusions i) TGF-β1 over-expressing mice may not be an appropriate model of Aβ-elicited CAA; and ii) pioglitazone has paradoxical effects on TGF-β1-induced pathology suggesting that anti-inflammatory therapy may reduce the damage resulting from active glia, but not from vascular alterations or hydrocephalus. Identification of the thioflavin-S-positive material will facilitate the full appraisal of the clinical implication of the effects of anti-inflammatory drugs, and provide a more thorough understanding of TGF-β1 actions in brain.

Abstract: A mass balance is formulated to evaluate the mobilization of chlorinated ethene compounds (CE) from the rock matrix of a fractured mudstone aquifer under pre‐ and postbioremediation conditions. The analysis relies on a sparse number of monitoring locations and is constrained by a detailed description of the groundwater flow regime. Groundwater flow modeling developed under the site characterization identified groundwater fluxes to formulate the CE mass balance in the rock volume exposed to the injected remediation amendments. Differences in the CE fluxes into and out of the rock volume identify the total CE mobilized from diffusion, desorption, and nonaqueous phase liquid dissolution under pre‐ and postinjection conditions. The initial CE mass in the rock matrix prior to remediation is estimated using analyses of CE in rock core. The CE mass mobilized per year under preinjection conditions is small relative to the total CE mass in the rock, indicating that current pump‐and‐treat and natural attenuation conditions are likely to require hundreds of years to achieve groundwater concentrations that meet regulatory guidelines. The postinjection CE mobilization rate increased by approximately an order of magnitude over the 5 years of monitoring after the amendment injection. This rate is likely to decrease and additional remediation applications over several decades would still be needed to reduce CE mass in the rock matrix to levels where groundwater concentrations in fractures achieve regulatory standards. [ABSTRACT FROM AUTHOR]

Abstract: Field characterization of a trichloroethene (TCE) source area in fractured mudstones produced a detailed understanding of the geology, contaminant distribution in fractures and the rock matrix, and hydraulic and transport properties. Groundwater flow and chemical transport modeling that synthesized the field characterization information proved critical for designing bioremediation of the source area. The planned bioremediation involved injecting emulsified vegetable oil and bacteria to enhance the naturally occurring biodegradation of TCE. The flow and transport modeling showed that injection will spread amendments widely over a zone of lower‐permeability fractures, with long residence times expected because of small velocities after injection and sorption of emulsified vegetable oil onto solids. Amendments transported out of this zone will be diluted by groundwater flux from other areas, limiting bioremediation effectiveness downgradient. At nearby pumping wells, further dilution is expected to make bioremediation effects undetectable in the pumped water. The results emphasize that in fracture‐dominated flow regimes, the extent of injected amendments cannot be conceptualized using simple homogeneous models of groundwater flow commonly adopted to design injections in unconsolidated porous media (e.g., radial diverging or dipole flow regimes). Instead, it is important to synthesize site characterization information using a groundwater flow model that includes discrete features representing high‐ and low‐permeability fractures. This type of model accounts for the highly heterogeneous hydraulic conductivity and groundwater fluxes in fractured‐rock aquifers, and facilitates designing injection strategies that target specific volumes of the aquifer and maximize the distribution of amendments over these volumes. [ABSTRACT FROM AUTHOR]

Major challenges exist in delineating bedrock fracture zones because these cause abrupt changes in geological and hydrogeological properties over small distances. Borehole observations cannot sufficiently capture heterogeneity in these systems. Geophysical techniques offer the potential to image properties and processes in between boreholes. We used three-dimensional cross borehole electrical resistivity tomography ( ERT) in a 9 m (diameter) × 15 m well field to capture high-resolution flow and transport processes in a fractured mudstone contaminated by chlorinated solvents, primarily trichloroethylene. Conductive (sodium bromide) and resistive (deionized water) injections were monitored in seven boreholes. Electrode arrays with isolation packers and fluid sampling ports were designed to enable acquisition of ERT measurements during pulsed tracer injections. Fracture zone locations and hydraulic pathways inferred from hydraulic head drawdown data were compared with electrical conductivity distributions from ERT measurements. Static ERT imaging has limited resolution to decipher individual fractures; however, these images showed alternating conductive and resistive zones, consistent with alternating laminated and massive mudstone units at the site. Tracer evolution and migration was clearly revealed in time-lapse ERT images and supported by in situ borehole vertical apparent conductivity profiles collected during the pulsed tracer test. While water samples provided important local information at the extraction borehole, ERT delineated tracer migration over spatial scales capturing the primary hydrogeological heterogeneity controlling flow and transport. The fate of these tracer injections at this scale could not have been quantified using borehole logging and/or borehole sampling methods alone. [ABSTRACT FROM AUTHOR]

Rates of trichloroethene (TCE) mass transformed by naturally occurring biodegradation processes in a fractured rock aquifer underlying a former Naval Air Warfare Center (NAWC) site in West Trenton, New Jersey, were estimated. The methodology included (1) dividing the site into eight elements of equal size and vertically integrating observed concentrations of two daughter products of TCE biodegradation- cis-dichloroethene ( cis-DCE) and chloride-using water chemistry data from a network of 88 observation wells; (2) summing the molar mass of cis-DCE, the first biodegradation product of TCE, to provide a probable underestimate of reductive biodegradation of TCE, (3) summing the molar mass of chloride, the final product of chlorinated ethene degradation, to provide a probable overestimate of overall biodegradation. Finally, lower and higher estimates of aquifer porosities and groundwater residence times were used to estimate a range of overall transformation rates. The highest TCE transformation rates estimated using this procedure for the combined overburden and bedrock aquifers was 945 kg/yr, and the lowest was 37 kg/yr. However, hydrologic considerations suggest that approximately 100 to 500 kg/yr is the probable range for overall TCE transformation rates in this system. Estimated rates of TCE transformation were much higher in shallow overburden sediments (approximately 100 to 500 kg/yr) than in the deeper bedrock aquifer (approximately 20 to 0.15 kg/yr), which reflects the higher porosity and higher contaminant mass present in the overburden. By way of comparison, pump-and-treat operations at the NAWC site are estimated to have removed between 1,073 and 1,565 kg/yr of TCE between 1996 and 2009. © 2012 Wiley Periodicals, Inc.* [ABSTRACT FROM AUTHOR]

Significant microbial reductive dechlorination of [1,2 14C] cis-dichloroethene (DCE) was observed in anoxic microcosms prepared with unamended, fractured rock aquifer materials, which were colonized in situ at multiple depths in two boreholes at the Naval Air Warfare Center (NAWC) in West Trenton, New Jersey. The lack of significant reductive dechlorination in corresponding water-only treatments indicated that chlororespiration activity in unamended, fractured rock treatments was primarily associated with colonized core material. In these unamended fractured rock microcosms, activity was highest in the shallow zones and generally decreased with increasing depth. Electron-donor amendment (biostimulation) enhanced chlororespiration in some but not all treatments. In contrast, combining electron-donor amendment with KB1 amendment (bioaugmentation) enhanced chlororespiration in all treatments and substantially reduced the variability in chlororespiration activity both within and between treatments. These results indicate (1) that a potential for chlororespiration-based bioremediation exists at NAWC Trenton but is limited under nonengineered conditions, (2) that the limitation on chlororespiration activity is not entirely due to electron-donor availability, and (3) that a bioaugmentation approach can substantially enhance in situ bioremediation if the requisite amendments can be adequately distributed throughout the fractured rock matrix. © 2012 Wiley Periodicals, Inc.* [ABSTRACT FROM AUTHOR]

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A new method was developed for conducting aquifer tests in fractured-rock flow systems that have a pump-and-treat (P&T) operation for containing and removing groundwater contaminants. The method involves temporary shutdown of individual pumps in wells of the P&T system. Conducting aquifer tests in this manner has several advantages, including (1) no additional contaminated water is withdrawn, and (2) hydraulic containment of contaminants remains largely intact because pumping continues at most wells. The well-shutdown test method was applied at the former Naval Air Warfare Center (NAWC), West Trenton, New Jersey, where a P&T operation is designed to contain and remove trichloroethene and its daughter products in the dipping fractured sedimentary rocks underlying the site. The detailed site-scale subsurface geologic stratigraphy, a three-dimensional MODFLOW model, and inverse methods in UCODE_2005 were used to analyze the shutdown tests. In the model, a deterministic method was used for representing the highly heterogeneous hydraulic conductivity distribution and simulations were conducted using an equivalent porous media method. This approach was very successful for simulating the shutdown tests, contrary to a common perception that flow in fractured rocks must be simulated using a stochastic or discrete fracture representation of heterogeneity. Use of inverse methods to simultaneously calibrate the model to the multiple shutdown tests was integral to the effectiveness of the approach. [ABSTRACT FROM AUTHOR]

The hydrogeologic framework of fractured sedimentary bedrock at the former Naval Air Warfare Center (NAWC), 1 Trenton, New Jersey, a trichloroethylene (TCE)-contaminated site in the Newark Basin, is developed using an understanding of the geologic history of the strata, gamma-ray logs, and rock cores. NAWC is the newest field research site established as part of the U.S. Geological Survey Toxic Substances Hydrology Program, Department of Defense (DoD) Strategic Environmental Research and Development Program, and DoD Environmental Security Technology Certification Program to investigate contaminant remediation in fractured rock. Sedimentary bedrock at the NAWC research site comprises the Skunk Hollow, Byram, and Ewing Creek Members of the Lockatong Formation and Raven Rock Member of the Stockton Formation. Muds of the Lockatong Formation that were deposited in Van Houten cycles during the Triassic have lithified to form the bedrock that is typical of much of the Newark Basin. Four lithotypes formed from the sediments include black, carbon-rich laminated mudstone, dark-gray laminated mudstone, light-gray massive mudstone, and red massive mudstone. Diagenesis, tectonic compression, off-loading, and weathering have altered the rocks to give some strata greater hydraulic conductivity than other strata. Each stratum in the Lockatong Formation is 0.3 to 8 m thick, strikes N65°E, and dips 25° to 70°NW. The black, carbon-rich laminated mudstone tends to fracture easily, has a relatively high hydraulic conductivity and is associated with high natural gamma-ray count rates. The dark-gray laminated mudstone is less fractured and has a lower hydraulic conductivity than the black carbon-rich laminated mudstone. The light-gray and the red massive mudstones are highly indurated and tend to have the least fractures and a low hydraulic conductivity. The differences in gamma-ray count rates for different mudstones allow gamma-ray logs to be used to correlate and delineate the lithostratigraphy from multiple wells. Gamma-ray logs and rock cores were correlated to develop a 13-layer gamma-ray stratigraphy and 41-layer lithostratigraphy throughout the fractured sedimentary rock research site. Detailed hydrogeologic framework shows that black carbon-rich laminated mudstones are the most hydraulically conductive. Water-quality and aquifer-test data indicate that groundwater flow is greatest and TCE contamination is highest in the black, carbon- and clay-rich laminated mudstones. Large-scale groundwater flow at the NAWC research site can be modeled as highly anisotropic with the highest component of permeability occurring along bedding planes. [ABSTRACT FROM AUTHOR]

The flowpath dependent approaches that are typically employed to assess biodegradation of chloroethene contaminants in unconsolidated aquifers are problematic in fractured rock settings, due to difficulties defining discrete groundwater flowpaths in such systems. In this study, the variation in the potential for chloroethene biodegradation with depth was evaluated in a fractured rock aquifer using two flowpath independent lines of field evidence: (1) the presence of the three biochemical prerequisites [electron donor(s), chloroethene electron acceptor(s), and chlororespiring microorganism(s)] for efficient chloroethene chlororespiration and (2) the in situ accumulation of chloroethene reductive dechlorination daughter products. The validity of this approach was assessed by comparing field results with the results of [1, 2-14C] cis-DCE microcosm experiments. Microcosms were prepared with depth-specific core material, which was crushed and emplaced in discrete packer intervals for 1 year to allow colonization by the indigenous microbial community. Packer intervals characterized by significant electron donor concentrations, elevated numbers of chlororespiring microorganisms, and high reductive dechlorination product to parent contaminant ratios correlated well with the production of 14C-labeled reductive dechlorination products in the microcosm experiments. These results indicate that, in the absence of information on discrete groundwater flowpaths, a modified approach emphasizing flowpath independent lines of evidence can provide insight into the temporal and spatial variability of contaminant biodegradation in fractured rock systems. [ABSTRACT FROM AUTHOR]

The bioavailability of total organic carbon (TOC) was examined in ground water from two hydrologically distinct aquifers using biochemical indicators widely employed in chemical oceanography. Concentrations of total hydrolyzable neutral sugars (THNS), total hydrolyzable amino acids (THAA), and carbon-normalized percentages of TOC present as THNS and THAA (referred to as “yields”) were assessed as indicators of bioavailability. A shallow coastal plain aquifer in Kings Bay, Georgia, was characterized by relatively high concentrations (425 to 1492 μM; 5.1 to 17.9 mg/L) of TOC but relatively low THNS and THAA yields (∼0.2%–1.0%). These low yields are consistent with the highly biodegraded nature of TOC mobilized from relatively ancient (Pleistocene) sediments overlying the aquifer. In contrast, a shallow fractured rock aquifer in West Trenton, New Jersey, exhibited lower TOC concentrations (47 to 325 μM; 0.6 to 3.9 mg/L) but higher THNS and THAA yields (∼1% to 4%). These higher yields were consistent with the younger, and thus more bioavailable, TOC being mobilized from modern soils overlying the aquifer. Consistent with these apparent differences in TOC bioavailability, no significant correlation between TOC and dissolved inorganic carbon (DIC), a product of organic carbon mineralization, was observed at Kings Bay, whereas a strong correlation was observed at West Trenton. In contrast to TOC, THNS and THAA concentrations were observed to correlate with DIC at the Kings Bay site. These observations suggest that biochemical indicators such as THNS and THAA may provide information concerning the bioavailability of organic carbon present in ground water that is not available from TOC measurements alone. [ABSTRACT FROM AUTHOR]

Background: The over-expression of transforming growth factor β-1(TGF-β1) has been reported to cause hydrocephalus, glia activation, and vascular amyloidβ (Aβ) deposition in mouse brains. Since these phenomena partially mimic the cerebral amyloid angiopathy (CAA) concomitant to Alzheimer's disease, the findings in TGF-β1 over-expressing mice prompted the hypothesis that CAA could be caused or enhanced by the abnormal production of TGF-β1. This idea was in accordance with the view that chronic inflammation contributes to Alzheimer's disease, and drew attention to the therapeutic potential of anti-inflammatory drugs for the treatment of Aβ-elicited CAA. We thus studied the effect of anti-inflammatory drug administration in TGF-β1- induced pathology. Methods: Two-month-old TGF-β1 mice and littermate controls were orally administered pioglitazone, a peroxisome proliferator-activated receptor-γ agonist, or ibuprofen, a non steroidal anti-inflammatory agent, for two months. Glia activation was assessed by immunohistochemistry and western blot analysis; Aβ precursor protein (APP) by western blot analysis; Aβ deposition by immunohistochemistry, thioflavin-S staining and ELISA; and hydrocephalus by measurements of ventricle size on autoradiographies of brain sections. Results are expressed as means ± SD. Data comparisons were carried with the Student's T test when two groups were compared, or ANOVA analysis when more than three groups were analyzed. Results: Animals displayed glia activation, hydrocephalus and a robust thioflavin-S-positive vascular deposition. Unexpectedly, these deposits contained no Aβ or serum amyloid P component, a common constituent of amyloid deposits. The thioflavin-Spositive material thus remains to be identified. Pioglitazone decreased glia activation and basal levels of Aβ42- with no change in APP contents - while it increased hydrocephalus, and had no effect on the thioflavin-S deposits. Ibuprofen mimicked the reduction of glia activation caused by pioglitazone and the lack of effect on the thioflavin-S-labeled deposits. Conclusions: i) TGF-β1 over-expressing mice may not be an appropriate model of Aβ-elicited CAA; and ii) pioglitazone has paradoxical effects on TGF-β1-induced pathology suggesting that anti-inflammatory therapy may reduce the damage resulting from active glia, but not from vascular alterations or hydrocephalus. Identification of the thioflavin-S-positive material will facilitate the full appraisal of the clinical implication of the effects of anti-inflammatory drugs, and provide a more thorough understanding of TGF-β1 actions in brain. [ABSTRACT FROM AUTHOR]

Evaluates the effect of falipamil on persistent atrial fibrillation induced by atrial pacing. Administration of the drug by slow intravenous injection; Similarity of the atrial anti-arrhythmic properties of falipamil to those of Class IA anti-arrhythmic agents; Justification of pacing-induced atrial fibrillation either because of the presence of documented atrial fibrillation or flutter or because of the possible involvement of the arrhythmia in the symptoms.

The article presents information on a study regarding the effects of a single intravenous injection of flecainide on acute episodes of supraventricular tachyarrhythmias. For this study, thirty patients were studied. Flecainide is a newly introduced antiarrhythmic agent. There are reports on its efficacy in the prevention of supraventricular and ventricular arrhythmias. The authors noted effects of flecainide on anterograde conduction through the atrioventricular node and retrograde conduction through accessory pathways, confirming multiple sites of action of flecainide in reentrant arrhythmias.

Although the influence of the autonomic nervous system on anterograde atrioventricular nodal coduction is well established, its effect on retrograde atrioventricular nodal conduction has not been examined systematically. Since retrograde atrioventricular nodal conduction in subjects with normal anterograde conduction may vary from intact retrograde conduction to complete retrograde block when assessed during ventricular pacing, in this study patients with (a) intact retrograde atrioventricular nodal conduction (group 1) were studied during parasympathetic (vagal) stimulation by carotid sinus pressure and during sympathetic inhibition (propranolol 0.2 mg·kg−1 intravenously) and (b) retrograde atrioventricular nodal block (group 2) were studied during vagal blockade (atropine 0.04 mg·kg−1 intravenously) and during sympathetic stimulation (isoproterenol 1-4 μg·min−1 infusion). In both groups changes in sinus cycle length and anterograde atrioventricular nodal conduction were measured. In group 1 vagal stimulation by carotid sinus pressure in 20 patients caused the cycle length at which retrograde atrioventricular nodal block was induced to be significantly lengthened from a mean(SD) of 375(59) to 451(51) ms in six patients; caused complete retrograde block in 10 patients; and had no effect in four patients. Sympathetic inhibition by propranolol in another 15 patients delayed the onset of pacing induced retorgrade atrioventricular nodal block from a mean(SD) of 340(60) to 418(80) ms in 11 patients; caused complete retrograde atrioventricular nodal block in three patients; and had no effect in one patient. In group 2 vagal blockade by atropine caused a 1 : 1 retrograde response during ventricular pacing up to a mean(SD) cycle length of 470(135) ms in six out of eight patients. The infusion of isoproterenol caused the retrograde atrioventricular nodal block to be abolished and 1 : 1 conduction to be resumed up to a ventricular pacing mean(SD) cycle length of 364(57) ms in six out of eight patients. It is concluded that (a) the autonomic nervous system modulates retrograde atrioventricular nodal conduction in a similar manner to its anterograde counterpart and (b) that since retrograde atrioventricular nodal conduction was reversible after the administration of either atropine or isoproterenol retrograde atrioventricular nodal block may be dynamic (physiological) rather than fixed (anatomical) in nature. [ABSTRACT FROM PUBLISHER]

The article explores on the electrophysiological properties of the accessory pathways (AP) in patients with Wolff-Parkinson-White Syndrome. Topics mentioned include the durations of the retrograde effective refractory periods of the APs, the response of the AP to an abrupt cycle length and the dependency of the cycle length in the cardiac tissue of the human beings.

Accurate localization of accessory pathways (AP) in the Wolff-Parkinson-White (WPW) syndrome requires detailed atrial .mapping. Coronary sinus catheterization is so far the most accurate method of left atrial mapping, but It can be technically difficult in some patients. We evaluated the feasibility of left atrial mapping from the left pulmonary artery in 24 patients with WPW syndrome. All patients except one underwent surgical cryoablation of their AP and the results of intraoperative mapping are available for comparison. Mapping in sinus rhythm showed recording of atria/activity in the distal left pulmonary artery occurred 56 ± 20 ms after activation of high right atrium and 24 ± 4 ms after activation in the His bundle area, but coincident with left atrial activation in the distal coronary sinus (56 ± 20 and 53 ± 13, respectively). Mapping during ventricular pacing or orthodromic tachycardia could differentiate patients as having a right sided, left sided or paraseptal first site of activation. Eleven patients had a left lateral AP, four had a left posterior AP, five had left posteroseptal AP and one had a left anterior AP. The remaining three patients had a right sided AP. Intraoperative results correlated with pre-operative findings in 22 out of 23 (95%) patients who underwent surgical ablation of AP. Thus, recordings form the left pulmonary artery reflect left atrial activity and may be of aid in localizing an AP, especially when coronary sinus recordings cannot be obtained. This technique, however,should not replace the more accurate method of coronary sinus mapping. [ABSTRACT FROM AUTHOR]

The properties of the atrioventricular (AV) nodal conduction and effective refractory period in man are generally evaluated at a constant basic cycle length (CL) and, in most cases, they demonstrate an inverse relationship to the drive cycle. The response of AV node to abrupt change in CL is less defined. We therefore studied the effects of abrupt changes in CL on AV nodal conduction time and refractoriness in 18 patients. AV nodal conduction time, and effective and functional refractory periods were measured during: (1) a constant long CL, (2) a constant short CL, and (3) after an abrupt increase m CL just prior to the introduction of extrastimuli. In 10 of the 18 patients a constant long CL of 600 ms, a constant short CL of 400 ms and a sudden short to long change in CL (400 to 600 ms) were tested. AV nodal conduction times (A2H2) were measured at the shortest and longest comparable A1A2 intervals. The mean value of the shortest A2H2 intervals for constant CL of 600 ms was 144 ± 18 ms; for a constant CL of 400 his it was 162 ± 17 ms; after a sudden short-to-long change in CL (400 to 600 ms) it was 142 ± 14 ms. The mean value of the longest A2H2 intervals at a constant CL of 600 ms was 185 ± 18 ms; at a constant CL of 400 ms it was 236 ± 26 ms (p < 0.01) and after a short-to-long change in CL (400 to 600 ms) 199 ± 21 ms. AV nodal effective refractory periods measured at the same three CLs had mean values of 279 ± 13 ms; 300 ± 15 ms and 294 ± 13 ms, respectively. Similar results were obtained when other CLs such as 700 to 900, 500 to 900, and 400 to 700 ms were tested. The data suggest that after abrupt short-to-long changes in CL, AV nodal function curves shift from long constant CL toward short constant CL as the coupling intervals decrease, indicating u cumulative pattern. Although the return to baseline conduction time after the fast basic rate is known to be slow, the limitation of this effect to the very early premature beat in the human has not been reported previously. [ABSTRACT FROM AUTHOR]

The electrocardiographic characteristics of spontaneous escape rhythm during complete heart block induced by transcatheter ablation of the atrioventricular junction was prospectively studied in 21 patients by periodically interrupting temporary pacing. The data derived from 13 of these 21 patients, in whom conduction recurred after the procedure, were analyzed. An escape rhythm was present In 12 patients 8.2 ± 5.8 minutes after shock delivery at a cycle length of 1985 ± 974 ms. The escape QRS had a configuration of right bundle branch block with left axis deviation in 9 patients, of right bundle branch block with normal axis in 1, of left bundle branch block with left axis deviation in 1, and 2 distinct morphologies in the remaining patient. After resumption of conduction, the conducted complexes were identical to the escape complexes in six patients, different only in axis in four patients, and different in morphology in two patients. This suggests that in the majority of patients the escape rhythm seen during transient heart block, induced by transcatheter ablation of the atrioventricular junction, presents a right bundle branch morphology with or without a left axis deviation, and most likely originates from an area above, or close to, the site of the anatomical damage. [ABSTRACT FROM AUTHOR]

We report on two patients out of a series of 22 who underwent transcatheter ablation of the atrioventricular (AV) junction. The procedure failed to induce permanent complete heart block in 15 patients, 12 of whom were in sinus rhythm with 1:1 AV conduction before hospital discharge. Of the 12 patients, two (16.6%) were found to be in high degree heart block, one month later. We discuss the mechanism of late occurrence of high degree heart block and we emphasize the need for systematic implantation of permanent ventricular or dual chamber pacemakers, despite failure transcatheter ablation of the AV junction. [ABSTRACT FROM AUTHOR]

In hernodialysis (HD) patients, serum prealbumin (TBPA) is correlated to nutritional status and outcome despite usually elevated serum levels. The purpose of this work was to study the role of TBPA-retinol-binding-protein (RBP)-retinol complex changes in the elevation of serum TBPA in HD patients. Serum TBPA, RBP, and retinol were measured in 30 otherwise healthy HD patients (15 men, 15 women) and in 30 healthy volunteers (15 men, 15 women). The dependence of TBPA on RBP was studied by covariance and regression methods. TBPA (p < 0.05), RBP (p < 0.0 1), and retinol (p < 0.05) were elevated in HD patients. Elevated TBPA was associated with a decrease of TBPA free from RBP (p < 0.01). The decrease of free TBPA may explain the reduction of TBPA breakdown and its elevation in HD patients. [ABSTRACT FROM AUTHOR]

On October 17, 1961, at the opening of the 22nd Communist Party Congress in Moscow, leader of the Communist Party Congress in Moscow in 1961 Nikita Khrushchev made the following announcement: "The tests of new nuclear weapons are proceeding successfully. We shall probably complete these by 30 or 31 October by a blast of fifty megatons." As if the undercurrent of a myth was moving through Khrushchev's words-a myth which continues to be relived in the U.S. on Halloween-the U.S. reaction to Khrushchev's speech, as faithfully reported by the Press, was mainly expressed in terms of Halloween and the myth attached to it.

This article focuses on the Halloween of the year 1963. On Halloween 1963 the world was confronted with the U.S. - Soviet Union clash and a showdown at Berlin, East Germany. Also with a call for war in Algeria, which became an undeclared border war. Then the New York Herald Tribune of October 12, 1963 spoke of `the treacherous October tidings pushing the United States and Russia in an eyeball con&ontation that could lead to conflict'. On October 23, 1963 the same New York Herald Tribune had the following heading: `On anniversary of missiles crisis gun play on high seas of Cuba.' The same issue contained a cartoon where U.S. President John F. Kennedy was riding through the sky on a broom,clad as a witch.