[Primary mucinous carcinoma of the eyelid. Case report]. / Carcinome mucineux primitif palpébral. À propos d'un cas.

Primary cutaneous mucinous carcinoma, a tumor of the sweat glands, is a rare tumor localized to the eyelid in 40% of cases. We report a case of a primary cutaneous mucinous carcinoma of the upper eyelid in a 53-year-old Caucasian male who appeared to have a chalazion. Histology showed rows and lobules of epithelial cells with discretely anisonucleotic nuclei and few mitotic figures scattered throughout the tumor cells, surrounded by a mucoid substance. Immunohistochemical analysis was cytokeratin 7 positive and cytokeratin 20 negative, and imaging and endoscopic screening were negative for metastasis, favoring the diagnosis of primary cutaneous mucinous carcinoma. Despite a high recurrence rate of about 35%, this type of tumor displays an indolent course, and metastatic spread is very rare.

Nitrogen potential recovery and concentration of ammonia from swine manure using electrodialysis coupled with air stripping.

The practice of intensive animal production in certain areas has resulted in excessive manure production for the available regional land base. Consequently, there is a need to develop treatment technologies to recover the valuable nutrients that manure contains so that the resulting product can be transported and used as fertilizer on agricultural land. The project presented here used electrodialysis in a dilution/concentration configuration to transfer the manure ammonia in the diluate solution by electromigration to an adjacent solution separated by an ion-exchange membrane under the driving force of an electrical potential. Then, air stripping from the electrodialysis-obtained concentrate solution without pH modification was used to isolate the ammonia in an acidic solution. An optimal process operating voltage of 17.5 V was first determined on the basis of current efficiency and total energy consumption. During the process, the swine manure pH varied from 8.5 to 8.2, values favourable for NH(4)(+) electromigration. Total ammonia nitrogen reached 21,352 mg/L in the concentrate solution, representing approximately seven times the concentration in the swine manure. Further increases in concentration were limited by water transfer from the diluate solution due to electroosmosis and osmosis. Applying vacuum to the concentrate reservoir was found to be more efficient than direct concentrate solution aeration for NH(3) recuperation in the acid trap, given that the ammonia recuperated under vacuum represented 14.5% of the theoretical value of the NH(3) present in the concentrate solution as compared to 6.2% for aeration. However, an excessively low concentrate solution pH (8.6-8.3) limited NH(3)volatilization toward the acid trap. These results suggest that the concentrate solution pH needs to be raised to promote the volatile NH(3) form of total ammonia nitrogen.

Protection of pancreatic INS-1 ß-cells from glucose- and fructose-induced cell death by inhibiting mitochondrial permeability transition with cyclosporin A or metformin.

Hyperglycemia is detrimental to ß-cell viability, playing a major role in the progression of ß-cell loss in diabetes mellitus. The permeability transition pore (PTP) is a mitochondrial channel involved in cell death. Recent evidence suggests that PTP inhibitors prevent hyperglycemia-induced cell death in human endothelial cells. In this work, we have examined the involvement of PTP opening in INS-1 cell death induced by high levels of glucose or fructose. PTP regulation was studied by measuring the calcium retention capacity in permeabilized INS-1 cells and by confocal microscopy in intact INS-1 cells. Cell death was analyzed by flow cytometry. We first reported that metformin and cyclosporin A (CsA) prevented Ca²+-induced PTP opening in permeabilized and intact INS-1 cells. We then showed that incubation of INS-1 cells in the presence of 30 mM glucose or 2.5 mM fructose induced PTP opening and led to cell death. As both metformin and CsA prevented glucose- and fructose- induced PTP opening, and hampered glucose- and fructose- induced cell death, we conclude that PTP opening is involved in high glucose- and high fructose- induced INS-1 cell death. We therefore suggest that preventing PTP opening might be a new approach to preserve ß-cell viability.

Fouling characterization of electrodialysis membranes used for the recovery and concentration of ammonia from swine manure.

The aim of the present study was to: (1) identify the nature of fouling for ED membranes (AMX and CMB, from Tokuyama Soda, Japan) used for the isolation and concentration of total NH(3)-N from swine manure, (2) determine the effect of fouling on membrane integrity, (3) establish the relation between fouling type and manure composition, and (4) estimate the efficiency of a two-step cleaning procedure to restore membranes properties. After processing 10 batches of swine manure (or 240 L/m(2)), the average current density as well as the membranes electrical conductivity and ion-exchange capacity decreased. The decline in process performance was associated with membrane fouling, since a significant deposit, possibly calcium carbonate and silica colloidal particles, was observed on the fouled AMX membranes. The electrical conductivity and ion-exchange capacity of the CMB membrane was completely restored by a two-step cleaning procedure using 0.5% NaOH and 1% HCl. However, for the electrical conductivity of the AMX membranes it was only partially recovered. The on-line cleaning procedure efficiency was assessed by measuring the stack average current density and the decrease of manure conductivity during 1h tests. Values for the cleaned membranes were, respectively, 95% and 91% the ones measured with the new membranes, and were significantly higher than for the fouled membranes.

Use of electrodialysis and reverse osmosis for the recovery and concentration of ammonia from swine manure.

This project aimed at producing a concentrated nitrogen fertilizer from liquid swine manure using electrodialysis (ED) and reverse osmosis (RO), as a mean to help resolve the excess nutrient problem faced by many swine producers, and offer an alternative to chemical nitrogen fertilizer production. Different types of ED membranes were evaluated based on the NH4+ transfer rate, current efficiency and membrane stability. A combination of CMB/AMX membranes was retained due to its high NH4+ transfer rate and chemical stability. The maximum total ammonia concentration (NH3-N) achievable by ED was limited by water transport from the manure to the concentrate compartment, and ammonia volatilization (17%) from the open concentrate compartment. Results suggested that, under the conditions of this experiment, a maximum total NH3-N concentration of about 16g/L could be reached with the ED system. An ED concentrate (8.7g/L of total NH3-N) was also fed to TFC-HF reverse osmosis membranes. A mass balance analysis revealed that the RO permeate, which represented 49.6% of the initial volume, contained 8.6% of the ammonia. However, the RO concentrate contained only 66.6% of the initial total NH3-N, suggesting that 21.2% of the ammonia was volatilized during the concentration test with RO membranes. Ammonia concentration in the RO concentrate reached approximately 13g/L, which is similar to the maximum concentration that could be achieved by ED. These results suggest that the use of ED and RO membranes to recover and concentrate ammonia is potentially interesting but the process must include an approach to minimize ammonia volatilization or trap volatilized ammonia.

A review of classification algorithms for EEG-based brain-computer interfaces.

In this paper we review classification algorithms used to design brain-computer interface (BCI) systems based on electroencephalography (EEG). We briefly present the commonly employed algorithms and describe their critical properties. Based on the literature, we compare them in terms of performance and provide guidelines to choose the suitable classification algorithm(s) for a specific BCI.

Chronic consumption of ethanol leads to substantial cell damage in cultured rat astrocytes in conditions promoting acetaldehyde accumulation.

AIMS: This study aimed at comparing the cerebral cytotoxicity of ethanol and its main metabolite acetaldehyde after acute or chronic exposures of rat astrocytes in primary culture. METHODS: Cytotoxicity was evaluated on the cell reduction of viability (MTT reduction test) and on the characterization of DNA damage by single cell gel electrophoresis (or comet assay). RESULTS: Changes in astrocyte survival and in DNA integrity only occurred when the astrocytes were chronically exposed to ethanol (20 mM; 3, 6 or 9 days). On the other hand, viability and DNA integrity were deeply affected by acute exposure to acetaldehyde. Both effects were dependent on the concentration of acetaldehyde. The cytotoxic effect of acetaldehyde was also indirectly evaluated after modifications of the normal ethanol metabolism by the use of different inducers or inhibitors. In presence of ethanol, the concomitant induction of catalase (i.e. by glucose oxidase) and inhibition of aldehyde dehydrogenase (i.e. by methylene blue) led to acetaldehyde accumulation within cells. It was followed by both a reduction in viability and a substantial increase in DNA strand breaks. CONCLUSIONS: These data were thus consistent with a possible predominant role of acetaldehyde during brain ethanol metabolism. On the other hand, the effects observed after AMT could also suggest a possible direct ethanol effect and a role for free radical attacks. These data were thus consistent with a possible predominant role of acetaldehyde during brain ethanol metabolism. On the other hand, the effects observed after AMT could also suggest a possible direct ethanol effect and a role for free radical attacks.

Amino porphyrins as photoinhibitors of Gram-positive and -negative bacteria.

Twenty four aminoporphyrin derivatives have been tested in vitro for their antibacterial photoactivity against Escherichia coli and Staphylococcus aureus. Two of these compounds, bearing polyamine units, exhibited a significant activity especially against Gram-negative bacteria (E. coli).

Ethanol can modify the effects of certain free radical-generating systems on astrocytes.

The central nervous system is vulnerable to oxidative stress, especially when a toxicant can modify the physiological balance between anti- and pro-oxidant mechanisms. Among brain cells, astrocytes seem less vulnerable than neurons, but their impairment can dramatically affect neurons because of their protective role toward neurons. Ethanol is able to stimulate the formation of reactive oxygen species and modify the activity of most of the antioxidant agents. However, ethanol can react with the OH* radical to form the alpha-hydroxyethyl radical, which is considered to be less toxic. Ethanol also can stimulate H2O2 degradation through catalase activation. This study, therefore, sought to determine whether ethanol affected the sensitivity of astrocytes exposed to various free radical-generating systems. The cellular impact of such exposure was assessed by assays exploring cytotoxicity (i.e., NR (neutral red) and MMT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetiazolium bromide) reduction assays) and genotoxicity (comet assay) induced by these treatments. DNA alterations were evaluated by single-cell gel electrophoresis (comet assay), considered a precocious biomarker of intracellular alterations. After concomitant exposure to H2O2 and ethanol, the viability of astrocytes decreased significantly whereas the mean percentage of DNA in the tail increased,reflecting DNA damage (H2O2 was either directly added to the culture medium or endogenously produced from menadione). Ethanol also reduced the loss of viability and DNA alterations after exposure to OH* radicals produced by a Fenton system. The exposure to a xanthine/xanthine oxidase system had the same effect.

Impact of ethanol and acetaldehyde on DNA and cell viability of cultured neurones.

Ethanol consumption has long been associated with brain damage. However, the mechanism underlying this deleterious effect remains unclear. Among different hypotheses, acetaldehyde is regarded by certain authors as playing a major role in the expression of ethanol toxicity, but there are still some uncertainties about the exact nature of its implication. We therefore tried to characterize the profile of the alterations of neuronal viability and DNA integrity obtained after either a direct exposure to ethanol or to acetaldehyde. Ethanol at concentrations within the range of blood alcohol levels in intoxicated humans (< or = 100 mmol/L) induced DNA alterations without any apparent effect on cell viability. Acetaldehyde (< or = 1000 micromol/L) can also induce DNA alterations but with a different profile of the DNA cellular alterations. The comparison between the distributions of the comet tail DNA indicated that ethanol induced strong breaks (tail DNA > or = 60 a.u.) generation whereas acetaldehyde rather induced lower breaks (20 < or = tail DNA < or = 50 a.u.) formation but affecting a greater number of neurones. Acetaldehyde had thus a different genotoxic potential which may suggest a different mode of action or a different cellular target. Furthermore, when a single 100 mmol/L ethanol exposure did not lead to any loss of cell viability, the addition of an inhibitor of aldehyde dehydrogenase was followed by a significant loss in viability. In contrast, the inhibition of catalase, which suppresses acetaldehyde synthesis, led to no reduced viability in the same exposure conditions. ROS also reduced viability, but this was observed only after both cytochrome P450 stimulation and catalase inhibition. These combined results could suggest that acetaldehyde may play a significant role in the expression of ethanol toxicity in brain.

Acute exposure of cultured neurones to ethanol results in reversible DNA single-strand breaks; whereas chronic exposure causes loss of cell viability.

AIMS: Ethanol can create progressive neuropathological and functional alterations of neurones. However, the influence of exposure duration is still debated. It is difficult to specify the level of alcohol consumption leading to alcohol-induced brain damage. Moreover, the mechanism of toxicity is assumed to combine direct and metabolically induced effects, although numerous uncertainties remain. Finally, the genotoxic power of ethanol has not fully been investigated in the brain. In the experiment reported herein, primary cultures of neurones were exposed either chronically or acutely to doses of ethanol within the range of blood alcohol levels in intoxicated humans. The impact on the integrity of neurones was assessed by cytotoxicity tests and DNA alterations by single-cell gel electrophoresis (Comet assay) and flow cytometry. Chronic ethanol exposure, even at a low dose, was more harmful to neurones than acute exposure. Both significant reductions in cell viability and DNA alterations were observed in this condition. On the other hand, DNA repair capacities seemed to be preserved as long as the viability measured by specific tests was not affected. Instead, neurones entered a death cell process compatible with apoptosis.

[French Guyana's case of renal pseudotumor caused by actinomycosis]. / Un cas guyanais d'actinomycose rénale pseudotumorale.

We report one case of renal pseudotumor caused by actinomycosis with cutaneous fistula in a young French Guyana's boy. Diagnosis before surgery and histology is difficult. CT is the best examination to evaluate the extent of the disease. A short review of the literature is presented.

Effect of added salt and increase in ionic strength on skim milk electroacidification performances.

Bipolar-memibrane electroacidification (BMEA) technology which uses the property of bipolar membranes to split water and the demineralization action of cation-exchange membranes (CEM), was tested for the production of acid casein. BMEA has numerous advantages in comparison with conventional isoelectric precipitation processes of proteins used in the dairy industry. BMEA uses electricity to generate the desired ionic species to acidify the treated solutions. The process can be precisely controlled, as electro-acidification rate is regulated by the effective current density in the cell. Water dissociation at the bipolar membrane interface is continuous and avoids local excess of acid. In-situ generation of dangerous chemicals (acids and bases) reduces the risks associated with the handling, transportation, use and elimination of these products. The aim of this study was to evaluate the performance of BMEA in different conditions of added ionic strength (p(added) = 0, 0.25, 0.5 and 1.0 M) and added salt (CaCl2, NaCl and KCl). The combination of KCl and p(added) = 0.5 M gave the best results with a 45% decrease in energy consumption. The increased energy efficiency was the result of a decrease in the anode/cathode voltage difference. This was due to an increase of conductivity, produced by addition of salt, necessary to compensate for the lack of sufficiently mobile ions in the skim milk. However, the addition of salts, irrespective of type or ionic strength, increased the required operation time. The protein profile of isolates were similar under all experimental conditions, except at 1.0 M-CaCl2.

Bipolar membrane electroacidification of demineralized skim milk.

The aim of this study was to evaluate the effect of decreasing the mineral content of skim milk by electrodialysis (ED) prior to electroacidification with bipolar membrane (BMEA) on the performance of the process, the chemical composition, and the physicochemical and functional properties of the isolates produced. ED used to demineralize the skim milk solution was very efficient. However, the electroacidification parameters were influenced by the demineralization level of the skim milk solution: the energy efficiency was decreased with an increase in demineralization, but it was still possible to perform BMEA at a very low conductivity level. Moreover, the isolates produced by BMEA after electrodialysis demineralization at different rates showed similar chemical composition, except on potassium and lactose contents for 75% demineralized isolate. These isolates, except on protein load for 75% demineralization rate, showed similar physicochemical and functional properties, whatever the demineralization rate.

Acceleration of pH variation in cloudy apple juice using electrodialysis with bipolar membranes.

The purpose of this study was to accelerate pH variation in cloudy apple juice using electrodialysis (ED). The testing was conducted using two ED configurations. The bipolar and cationic membrane configuration showed that reducing the spacing from 8 to 0.75 mm had little effect on treatment time, whereas stacking eight bipolar membranes reduced acidification time by 30%, although the treatment still took too long (21 min). Furthermore, it was not possible to acidify apple juice to a pH of 2.0 to completely inhibit enzymatic browning. The bipolar and anionic membrane configuration helped to accelerate the acidification step by a factor of 3, increasing the yield from 3.3 to 10 L of juice/m(2) membrane/min. Moreover, treatment time was inversely proportional to the size of the membrane stack. The speed at which the pH of acidified juice returned to its initial value was, however, 4 times slower than the speed of acidification, giving a yield of 2.5 L of juice/m(2) membrane/min. By accelerating the acidification step, ED treatment with bipolar and anionic membranes results in more effective polyphenol oxidase activity and more rapid control of juice browning at pH 2.0. Also, the treatment has very little effect on the chemical composition and organoleptic quality of apple juice.

Effect of cationic membrane permselectivity on the efficiency of skim milk electroacidification.

Bipolar membrane electroacidification (BMEA) uses the property of bipolar membranes to split water and the demineralization action of cation-exchange membranes (CEM). As milk mineral salt content is very sensitive to ionic strength and pH changes, the aim of this study was to better understand the effect of changes in mineral content during pH decrease and demineralization of skim milk. The objectives were to investigate the effect of different cationic permselective membranes (CSV and CMX membranes) on skim milk cation migration and protein precipitation during BMEA. The permselectivity of both membranes tested does not influence the final efficiency of BMEA. The purity of the bovine milk casein isolates produced was similar to or higher (97-98% versus 93.4-96.7) than those of commercial isolates, due to a reduced ash content (1.2 versus 2.0-3. 8%) resulting from the CEM demineralizing phenomenon. For both membranes, the main ionic species to migrate was the potassium ions.

Effect of temperature on the separation of soybean 11 S and 7 S protein fractions during bipolar membrane electroacidification.

The purpose of this study was to evaluate the effect of temperature (10 and 27 degrees C) on the efficiency of bipolar membrane electroacidification (BMEA) to fractionate soybean proteins. BMEA is a technology derived from electrodialysis, based on the isoelectric precipitation of proteins. It appears that temperature has a significant effect on the selective precipitation of the soybean protein fractions, mainly 11 S and 7 S, during BMEA. At 27 degrees C, the precipitation profile of the four protein fractions is situated in a pH range from 6.6 to 4.4, with no possibility of separating any of theses fractions. However, at 10 degrees C, the 11 S globulin precipitates at a higher pH than at 27 degrees C, pH 6.7 vs 5.9, allowing the fractionation of 11 S from the other fractions. Using electroacidification it is possible to obtain a precipitate solution enriched in the 11 S fraction (71.8% of 11 S and 10.8% of 7 S) and a supernatant solution enriched in the 7 S fraction (46.6% of 7 S and 4.6% of 11S).

Bipolar membrane electroacidification to produce bovine milk casein isolate.

Bipolar membrane electroacidification (BMEA) has been developed previously (Bazinet et al., Report for the Canadian Electricity Association 9326 U 987, 1996; Bazinet et al., J. Agric. Food Chem. 1997, 45, 2419-2425, 3788-3794) and has been used for isoelectric precipitation of soybean proteins. The purpose of this study was to validate the feasibility of BMEA for the precipitation of milk casein and to investigate the effect of flow rate. High-purity isolates containing 1.23 and 2.00% ash and 85.4 and 91.6% total protein were obtained with flow rates of 0.2 and 1.2 gal/min. The molecular composition profiles of the isolates obtained by HPLC showed that only caseins were precipitated. However, except for protein precipitation curves, the flow rate did not influence the final composition and purity of the isolates. These results showed that BMEA is a new alternative process for the production of high-purity bovine milk casein isolate.

The monolayer technique as a tool to study the energetics of protein-protein interactions.

In this paper, we explore the possibility of using the monolayer technique and hydrophobic homopolypeptides to study the energetics of protein stability. We have studied the stabilization of the bilayer state of poly-L-alanine in its alpha-helical conformation at the air-water interface by measuring compression and expansion surface pressure (II)-residual area (A) isotherms at 22 +/- 2 degrees C. The Gibbs free energy of stabilization per alanyl residue transferred from the water exposed state in the monolayer to the inside of the bilayer was calculated from the surface area of the hysteresis loops obtained during compression-expansion cycles performed during the monolayer to bilayer transition. Using atomic solvation parameters and the water accessible surface area per atom group for an alanyl residue in a standard alpha-helix, we have dissected the free energy of stabilization per alanyl residue into the change of solvation free energy (delta Gs) upon transfer from the water surface to the inside of the bilayer state, and the free energy associated to the formation of hydrophobic van der Waals interactions (delta GvdW) in the bilayer. We estimate a value of 25 +/- 4 cal/(mol A2) for the hydrophobic interaction, as defined by the sum of delta Gs and delta GvdW per unit of hydrophobic (aliphatic) accessible surface area in an alanyl residue.

Effect of inoculation techniques and relative humidity on the growth of molds on the surfaces of yellow layer cakes.

FOUR INOCULATION TECHNIQUES WERE COMPARED FOR INITIATION OF GROWTH ON CAKE SURFACES: spot, air cabinet, spray (atomizer), and talc addition methods. Molds were isolated from commercial cakes and were identified as Aspergillus sydowii, Aspergillus ochraceus, Penicillium funiculosum, and Eurotium herbariorum. Cake surfaces were inoculated with mold spores and incubated under three equilibrium relative humidity (ERH) levels: 97, 85, and 75%. Random contamination by spores in a ventilated air cabinet was the simplest method of inoculation, but standard deviations in the inoculation rates (20% on a relative scale) were almost twice those observed with the other methods. The spot method was the most reproducible. Cake samples inoculated in the air cabinet had colony counts 10 times lower than those obtained for potato dextrose agar plates at 97% ERH, which was not the case with the spray and talc methods. Growth of molds was much slower in the samples incubated in 75% relative humidity, with all methods. Colony counts were generally similar in systems adjusted at 85 to 97% ERH but were lower for samples incubated at 75% ERH. In comparisons of the shelf life estimates obtained by the various inoculation methods, a correlation coefficient (r) of 0.70 was obtained between the spot method and the other methods of inoculation, while talc, air cabinet, and spray shelf life data were correlated better (r approximately 0.97). The spot method appeared to be the method of choice in consideration of ease of use, precision, and the ability to enable the study of the effects of the environment on mold-free shelf life as well as on the rate of growth of molds on cakes.