Central pontine myelinolysis. A case report with typical neuropathological findings

A case of central pontine myelinolysis (CPM) in an alcoholic patient with severe electrolyte changes is presented. Data in the literature suggest that it is safe to correct severe symptomatic hyponatremia to a value of 125-130 mEq/1 in 24 h. At the present time acute severe hyponatremia carries a bad prognosis if not treated with hypertonic NaCl solution. Electrolyte abnormalities are not the sole cause of CPM.

A 24-m3 direct heat-sink calorimeter with on-line data acquisition, processing, and control

The construction and performance of a 24-m3 direct heat-sink calorimeter for continuous measurement of evaporative and sensible heat loss in human subjects are described. Extensive use of real-time processing for compensation of physical time constants and delays made it possible to solve response-time and stability problems associated with the large volume. The performance characteristics of the calorimeter are 1) a linear response between 0 and 320 W (471 g . h-1) for evaporative heat with a precision of 4.0-0.6% in the range 25-100 W, 2) a linear response between 0 and 280 W for sensible heat with a precision of 1.4-0.2% in the range 50-200 W, 3) a stability corresponding to a drift of less than 0.6 W (24 and 72 h) on both evaporative and sensible heat outputs and 24- and 72-h standard deviations (values every 2 min) of 0.3 and 0.4 W for evaporative heat and 0.6 and 0.7 W for sensible heat, 4) response times (95%) of 15 min for both evaporative and sensible heat, 5) independency on the position of the calibration source within the chamber, 6) no measurable "cross talk" between evaporative and sensible heat inputs, 7) negligible dependency of the external air humidity between 14 and 70%, and 8) operating temperature range from 18 to 30 degrees C. More than 40 experiments of 25-h duration with human subjects have been carried out. In no case was any discomfort recorded. An example of the 25-h continuous evaporative and sensible heat output tracing of one experiment is given.

Interfacial Charge Separartion in the Photoreduction of Water: Effects of Colloidal Silica

It has been confirmed that colloidal silica can retard reverse electron transfer in the photochemical system water/ tris (2,2′- bipyridine )ruthenium dication/triethanolamine/zwitterionic viologen . However, the beneficial effect of silica diminishes as the concentration of the electron donor ( triethanolamine ) increases. Substantially higher yields of hydrogen have been obtained with 2,2′,6,6′-tetramethyl-1,1′- di (3-sulfonatopropyl)-4,4′-bipyridinediium which is more stable and has a more favourable potential than previously used electron-transfer agents.

Liver attenuation values at computed tomography related to liver copper content

Forty-three patients were examined with computed tomography of the liver and liver biopsies with measurement of hepatic copper content. All recorded liver attenuation values were within normal range, even in patients with markedly elevated hepatic copper content. No statistically significant correlation between the liver attenuation values and the copper concentrations in liver tissue was demonstrated. At present, therefore, computed tomography has no place in monitoring the development of copper accumulation.

A long-term follow-up study of the hepatic copper and serum ceruloplasmin concentrations in patients with chronic liver disease

Hepatic copper content, measured by neutron activation analysis, has been studied in 70 patients during a median observation period of 3 years. In 15 patients with chronic active hepatitis the median hepatic copper content was 39 micrograms/g dry weight at the start and 28 micrograms/g dry weight at the end of the observation period, during which the clinical condition was improved in most patients. The hepatic copper content did not change significantly (41 versus 54 micrograms/g dry weight) in 28 patients with hepatobiliary disorders associated with inflammatory bowel disease. In 27 patients with primary biliary cirrhosis the median hepatic copper concentration was initially 176 micrograms/g dry weight, and at the follow up 186 micrograms/g dry weight. Serum ceruloplasmin was elevated in most of the patients with hepatobiliary disorders associated with inflammatory bowel disease and in all the patients with primary biliary cirrhosis and remained at high levels throughout the observation period. In primary biliary cirrhosis the hepatic copper content was correlated with bilirubin and alkaline phosphatases but not with ceruloplasmin, coagulation factors, or aminotransferases. Ceruloplasmin was not significantly correlated with other "liver tests". We conclude that the hepatic copper content and serum ceruloplasmin were remarkably constant during 3 years of observation in various liver disorders. Our study gave no evidence of a hepatotoxic effect of copper, since no relation between the initial hepatic copper concentration and the clinical course could be detected.

Solar reduction of water. I. Competition between light-induced hydrogen formation and hydrogenation of methylviologen in the system water-Tris(2,2'-bipyridine)ruthenium dication-ethylenediaminetetraacetic acid-platinum

The light-induced formation of hydrogen in the system H2O-Ru(bpy)32+-mv2+-edta-Pt (mv, inethylviologen) is accompanied by the hydrogenation of mv2+ to give the 1-methyl-4-(1'-methylpiperidin-4'-yl)pyridinium cation (1). The production of hydrogen is decreased by factors that favour the formation of this cation. The extent of hydrogenation depends on the pH of the mixture, the amount and type of catalyst present, and the partial pressure of hydrogen during irradiation.

Solar reduction of water. II. Inhibition of the hydrogenation of methyl viologen in the system water-Tris(2,2'-bipyridine)ruthenium(II) dication-ethylenediaminetetraacetic acid-platinum by sulfur compounds

The light-induced formation of hydrogen in the system H2O-Ru(bpy)32+-mv2+-edta-Pt is accompanied by the hydrogenation of mv2+. This hydrogenation process is suppressed by the addition of cysteine or glutathione. Substantial increases in the turnover numbers of mv2+ and the yields and rates of hydrogen production are achieved.

Light-induced electron-transfer reactions involving the tris(2,2'-bipyridine)ruthenium dication and related complexes. I. The bis(2,2'-bipyridine)(diethyl 2,2'-bipyridine-4,4'-dicarboxylate)ruthenium dication

Irradiation of the bis(2,2'-bipyridine)(diethyl 2,2'-bipyridine-4,4'- dicarboxylate)ruthenium(II) dication (2c) in water, in the presence of ethylenediaminetetraacetic acid, methyl viologen and a platinum catalyst, produces hydrogen at about one-tenth the rate observed with Ru(bpy)32+. This decrease is ascribed to electron withdrawal by the ester group in (2c) and to bimolecular quenching of photo-excited (2c) by water (rate constant 9.3 × 104 1. mol-1 s-1), which follows (in ethanol) Stern-Volmer kinetics (KSV 9.5 x 10-2 1. mol-1).

Liver copper content in patients with inflammatory bowel disease and associated liver disorders

In 45 patients with inflammatory bowel disease (9 with Crohn's disease and 36 with ulcerative colitis) and associated liver disorders, increased liver copper content (above 100 microgram/g dry weight) was found in 14 (31%). These patients represented about 50% of the patients with either biliary cirrhosis or pericholangitis. Four of the patients had levels regarded as compatible with hepatolenticular degeneration (greater than 250 microgram/g dry weight). In patients with chronic active hepatitis or non-specific changes in liver tissue, normal levels were found. The patients with Crohn's disease also had normal levels. Plasma ceruloplasmin was normal or increased in all. Determination of urinary copper output gave little diagnostic information. Alkaline phosphatases were markedly increased in most of the patients with increased liver copper concentration. In patients with ulcerative colitis and enhanced alkaline phosphatases, elevated liver copper content should be suspected and chelation therapy should be considered.

Energy Transfer in Monolayer Assemblies of Surfactant Ruthenium Complexes

Energy transfer in monolayer assemblies has been studied with bis(2,2'-bipyridyl)(dioctadecyl 2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) perchlorate (1) as acceptor and bis(2,2'-bipyridyl)- (4,4'-dieicosyl-2,2'-bipyridyl)ruthenium(II) perchlorate (2), bis(2,2'-bipyridyl)(4-eicosyl-4'-methyl- 2,2'-bipyridyl)ruthenium(II) perchlorate (3), or bis(o-phenanthroline)(4,4'-dioctadecyl-2,2'-bipyridyl)- ruthenium(II) (4) as donor. Forster theory was used to analyse transfer rate constants, obtained by measuring the reduction in intensity of the donor luminescence in the presence of acceptors. This luminescence quenching involves energy transfer and not electron transfer because of the sensitized luminescence intensity of the acceptor. The efficiency of energy transfer depends on the relative orientations of the alkyl chains. The observed rates of transfer greatly exceed the efficiency predicted from the Forster theory for the distance between the chromophores; it is suggested that the alkyl chains take part in the transfer of excitation energy. This effect can be largely suppressed by the insertion of a 'spacer' monolayer of cadmium arachidate between donor and acceptor layers.

Preparation and Properties of Surfactant Complexes of Ruthenium(II)

New surfactant complexes RuM2L2+ have been prepared where M is 2,2'-bipyridyl or o-phenanthro- line and L is one of the 4-alkyl-4'-methyl-2,2'-bipyridyls (8a)-(8e), or one of the 4,4'-dialkyl-2,2'- bipyridyls (9a)-(9e), or 1,1'-(2,2'-bipyridyl-4,4'-diyl)bis(nonadecan-1-one). This diketone was pre- pared from 2,2'-bipyridyl-4,4'-dicarboxylic acid and dioctadecylcadmium; the dialkylbipyridyls were obtained by condensing 4,4'-dimethyl-2,2'-bipyridyl with 5-alkylthiopen-2-carbaldehydes, followed by desulfurization with W5 Raney nickel. Several properties of the new complexes have been compared with those of bis(2,Y-bipyridyl)(dioctadecyl 2,2'-bipyridyl-4,4'-dicarboxy1ate)ruthenium dication (2). Monolayers have been prepared and characterized by surface-pressure area curves; film com- pressibilities and stabilities are related to the lengths of the alkyl chains and to subphase composition. Absorption and emission spectra have been examined. The quantum yields and lifetimes of emission are similar in alcohol and water; with monolayer assemblies they are dependent on subphase com- position, and in the solid state they vary between 0.03-0.18 for Φ and 0.5-1.5 μs for τ, according to the chain lengths, which appear to affect crystal packing. Oxygen quenched the luminescence of solutions and supported monolayers reversibly; Stern- Volmer constants and bimolecular quenching constants are given for: diester complex (2), diketone complex (6), dialkylbipyridyl complexes (5). Except with (2) the original luminescence intensity was restored by drying. Hydrogen was not detected following irradiation with visible light of supported monolayers of pure complexes immersed in water.

Electrochemical synthesis of amino acids by reductive amination of keto acids. II. Reduction at platinum black and palladium black electrodes

2-Amino-2-phenylacetic acid, monoammonium glutamate, 2-aminobutyric acid, α-alanine and ammonium 5-amino-5-phenylvalerate have been prepared by electrochemical reductive amination of the corresponding keto acids (or their sodium salts) in aqueous ammonia. Platinum black, platinum black/Teflon composite on tantalum gauze and palladium black were used as electrodes. The yields ranged from 40% for α-alanine and ammonium 5-amino-5-phenylvalerate to 83% for 2-amino-2-phenylacetic acid, at ammonia concentrations from 4.7 to 15.5 M. The corresponding reduction potentials were all between -0.82 and -0.90 V relative to a saturated calomel electrode. Decreasing the ammonia concentration decreased both the yield and the current efficiency for reductive amination of 2-oxo-2-phenylacetic acid. ��� 2,5-Diphenylimidazol-4-ol was prepared and isolated from a concentrated solution of 2-oxo-2-phenylacetic acid in strong ammonia. Small amounts of this compound probably cause the yellow coloration observed during electrolysis of 2-oxo-2-phenylacetic acid.

Amplifications of phleomycin and bleomycin-induced antibiotic activity in Escherichia coli by aromatic cationic compounds

A wide range of aromatic compounds has been shown to amplify phleomycin-induced cell killing in Escherichia coli. They include acridines, acridinium chlorides, dihydroanthracenes, anthracenes, dianthracenes, phenanthridinium salts, phenazinium chlorides, phenoxazones, triphenyl methane dyes, benzoquinolizinium chloride, diphenylmethane derivatives, stilbene and diphenyl derivatives. Low concentrations of these amplifiers also amplified the DNA breakage and degradation effects of phleomycin. The minimum structural specification for activity as an amplifying agent is suggested. A representative sample of compounds effective as amplifiers of phleomycin also amplified the antibiotic effects of bleomycins B4 and B6. The amplifiers described are known to vary in their ability to penetrate and accumulate in different organisms or tissues. This suggests the possibility of developing a series of antibiotic regimes using these amplifiers (or the large number of derivative compounds also likely to be active) where the therapeutic index is determined by the properties of the amplifier chosen rather than of the phleomycin or the bleomycin.