Azo dyes decolorization under high alkalinity and salinity conditions by Halomonas sp. in batch and packed bed reactor.

Biodecolorization and biodegradation of azo dyes are a challenge due to their recalcitrance and the characteristics of textile effluents. This study presents the use of Halomonas sp. in the decolorization of azo dyes Reactive Black 5 (RB5), Remazol Brilliant Violet 5R (RV5), and Reactive Orange 16 (RO16) under high alkalinity and salinity conditions. Firstly, the effect of air supply, pH, salinity and dye concentration was evaluated. Halomonas sp. was able to remove above 84% of all dyes in a wide range of pH (6-11) and salt concentrations (2-10%). The decolorization efficiency of RB5, RV5, and RO16 was found to be ≥ 90% after 24, 13 and 3 h, respectively, at 50 mg L-1 of dyes. The process was monitored by HPLC-DAD, finding a reduction of dyes along the time. Further, Halomonas sp. was immobilized in volcanic rocks and used in a packed bed reactor for 72 days, achieving a removal rate of 3.48, 5.73, and 8.52 mg L-1 h-1, for RB5, RV5 and RO16, respectively, at 11.8 h. The study has confirmed the potential of Halomonas sp. to decolorize azo dyes under high salinity and alkalinity conditions and opened a scope for future research in the treatment of textile effluents.

Damage costs produced by electric power plants: an externality valuation in the Mexico City Metropolitan Area.

This paper presents an estimate of the externalities produced in the Mexico City Metropolitan Area (MCMA) through the impacts on health caused by secondary pollutants attributed to seven electric power plants located outside this area. An original method was developed to make possible a simplified application of the impact pathway approach to estimate the damage costs in the specified area. Our estimate shows that the annual costs attributed to secondary pollutants total 71 million USD (min/max 20/258 million USD). Finally, this paper discusses basic ideas on the implications for energy policy arising from this exercise in externality valuation.

Liposomal gD ectodomain (gD1-306) vaccine protects against HSV2 genital or rectal infection of female and male mice.

Herpes simplex virus type 2 (HSV2) is the most common causative agent of genital herpes, with infection rates as high as 1 in 6 adults. The present studies were done to evaluate the efficacy of a liposomal HSV2 gD(1-306) vaccine (L-gD(1-306)-HD) in an acute murine HSV2 infection model of intravaginal (female) or intrarectal (male or female) challenge. Two doses of L-gD(1-306)-HD containing 60 microg gD(1-306)-HD and 15 microg monophosphoryl lipid A (MPL) per dose provided protection against HSV2 intravaginal challenge (86-100% survival, P< or =0.0003 vs. control liposomes; P=0.06 vs. L-gD(1-306)-HD without MPL). Both male and female mice (BALB/c and C57BL/6) immunized with L-gD(1-306)-HD/MPL were significantly protected against HSV2 intrarectal challenge, with higher survival rates compared to controls (71-100%, P< or =0.007). L-gD(1-306)-HD/MPL also provided increased survival when compared to a liposomal peptide vaccine, L-gD(264-285)-HD/MPL (male BALB/c, P

Extraction and determination of ellagic acid contentin chestnut bark and fruit.

Chestnuts are an important economic resource in the chestnut growing regions, not only for the fruit, but also for the wood. The content of ellagic acid (EA), a naturally occurring inhibitor of carcinogenesis, was determined in chestnut fruits and bark. EA was extracted with methanol and free ellagic acid was determined by HPLC with UV detection, both in the crude extract and after hydrolysis. The concentration of EA was generally increased after hydrolysis due to the presence of ellagitannins in the crude extract. The concentration varied between 0.71 and 21.6mgg(-1) (d.w.) in un-hydrolyzed samples, and between 2.83 and 18.4mgg(-1) (d.w.) in hydrolyzed samples. In chestnut fruits, traces of EA were present in the seed, with higher concentrations in the pellicle and pericarp. However, all fruit tissues had lower concentrations of EA than had the bark. The concentration of EA in the hydrolyzed samples showed a non-linear correlation with the concentration in the unhydrolyzed extracts.

La actuación del Cuerpo de Sanidad de la Armada en la Batalla de Trafalgar / Navy health coros performance in the Battle of Trafalgar

Estudiamos en este artículo la Sanidad de la Armada Española en el siglo XVIII, el Colegio de Cirujanos de Cádiz y su contribución sanitaria a la Batalla de Trafalgar

We review the spanish Navy Health coros along the XVIIIth century, the Surgeon´s college of Cadiz and its contribution to the Battle of Trafalgar

Two cases of catastrophic antiphospholipid syndrome.

Catastrophic antiphospholipid syndrome (CAPS) is a rare complication of antiphospholipid syndrome. It is a disseminated severe vascular pathology which presents with multi-organic dysfunction that progresses rapidly. Prognosis ends up being fatal in half of the cases. It may appear during pregnancy, surgery, infection, or after suspension of anticoagulation therapy. We studied two female patients with CAPS who survived after treatment with anticoagulation therapy and intravenous corticosteroids. The evolution of our two patients, after 17 months of follow-up under oral anticoagulant treatment was favourable and they are currently asymptomatic. In these patients the early diagnosis and treatment were essential to enhance their possibilities of survival.

[The gas-liquid cromatography with mass spectrometry for the identification of yeasts]. / La cromatografía gas-líquido con espectrometría de masas en la identificación de levaduras.

Methods based on gas chromatography, have been used for identification of the yeasts. In order to know the value of the patterns obtained by this method, we have used this technique and mass spectrometry on 44 strains belonging to 16 genus and 21 species of collection yeasts, identifying the corresponding peaks to 22 fatty acids methyl esters by means of the reaction times of the corresponding standards and the confirmation of molecular weigh by mass spectrometry. The correlation coefficient was of 0.848965. The chromatographic technique seems of great utility for the determination of lipidotypes.

Aislamiento e identificación de una cepa de Nocardia en un paciente con infección respiratoria / Isolation and identification of an strain of Nocardia in a patient with a respiratory infection

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Resveratrol is a potent inhibitor of the dioxygenase activity of lipoxygenase.

Resveratrol is a naturally occurring phytoalexin, present in grapes and other food products, with important antioxidant properties. Although still under debate, it is generally assumed that resveratrol has protective effects against heart diseases and probably tumor development. Lipoxygenase is a dioxygenase with peroxidase activity involved in the synthesis of mediators in inflammatory, atherosclerotic, and carcinogenic processes. Lipoxygenase activity is also involved in the generation of flavors and aromas in foods from animal or vegetal sources. The results presented here show that resveratrol was a potent inhibitor of the dioxygenase activity of lipoxygenase, with an IC(50) = 13 microM. Simultaneously, resveratrol was oxidized by the peroxidase activity of lipoxygenase with a V(max) = 0.28 microM min(-1) and a k(M) = 16.6 microM. Furthermore, oxidized resveratrol was as efficient a lipoxygenase inhibitor as in its reduced form. From the data obtained it can be concluded that both resveratrol and its oxidized form can act as inhibitors of the dioxygenase activity of lipoxygenase. In contrast, the hydroperoxidase activity of lipoxygenase was not inhibited by resveratrol. These results suggest that resveratrol may be used as an antioxidant food additive and as a pharmacological agent to prevent the generation of eicosanoids involved in pathological processes.

The use of fluorescein 5'-isothiocyanate for studies of structural and molecular mechanisms of soybean lipoxygenase.

Incubation of fluorescein 5'-isothiocyanate (FITC) with soybean lipoxygenase produces the coupling of 1 mol of fluorophore to 1 mol of enzyme. Derivatized lipoxygenase lost 40% activity through a mixed-type inhibitory mechanism. The quenching by IK of the fluorescence of FITC-labeled lipoxygenase shows that the fluorophore is located near the surface of the protein. The partial impediment of the FITC labeling when the substrate is present in the medium, together with data of the tryptic digestion, suggests that FITC is attached via the access channel of substrate to the catalytic site. Labeling does not induce appreciable modification of the enzyme specificity, suggesting that the position of substrate in the active site is not modified by the labeling. The results obtained strongly suggest that FITC labels soybean lipoxygenase specifically at a lysyl residue which contributes to fixation of the carboxylic end of the substrate to the active center. The experimental data obtained from the quenching of FITC fluorescence by NDGA reveal that this molecule interacts with the protein near the catalytic site.

[Virulence plasmid in Yersinia enterocolitica O:3 of murine origin]. / Plásmido de virulencia en yersinia enterocolitica O:3 de origen murino.

BACKGROUND: Pathogenic strains of Yersinia enterocolitica harbor a virulence plasmid of 45-48 megadalton that can be detected using different techniques. Rodents are important reservoirs of Y enterocolitica. AIM: To investigate the carrier status of Y enterocolitica in murine rodents. MATERIAL AND METHODS: Two hundred sixty-one mice and rats were captured in rural and urban areas of Valdivia. Y enterocolitica was cultured from viscera and fecal homogenates. Virulence plasmids were detected using crystal violet binding. RESULTS: Thirteen Y enterocolitica strains were isolated from 11 rodents. Ten strains belonged to the biotype 1 and three to the biotype 4, serotype O:3. The most frequently infected rodent species were R norvergicus (20%), followed by A longipilis (11%), A olivaceus (2%) and O longicaudatus (2%). CONCLUSIONS: Rodents, and specially the domestic rat, can be an important source of Y enterocolitica infection for human and susceptible animal species.

Are medical mailing lists reliable sources of professional advice?

Professional mailing lists are one of the more useful and popular medical resources on the Internet. Some concern has been raised about the reliability of these uncontrolled forums. We have studied some quality aspects of a subset of Internet mailing lists on nephrology. From November 1996 to March 1997 the mailing lists NEPHROL, PDIAL-L and HYPERTEL were studied. The subscribers that posted, and a representative sample of the total number of subscribers of each list, were searched in the Medline Silver-Platter database, and their individual impact factors were obtained from the Science Citation Index. In addition, the first authors of the original articles, and short communications from the more established nephrology journals, were searched similarly, in order to compare the mailing lists with the journals. NEPHROL was the most active list (7 postings/day on average). HYPERTEL had the best average impact factor among the subscribers who posted (6.6). In general, the journals showed higher average impact factors than the mailing lists, but without statistically significant differences. HYPERTEL, PDIAL-L and NEPHROL are high quality nephrology mailing lists, and can be considered as a complement to the specialized nephrology journals.

Immobilization of potato tuber lipoxygenase on oxirane acrylic beads.

In this study, lipoxygenase from potato tuber has been purified by a method involving hydrophobic chromatography and the purified enzyme immobilized by covalent coupling to oxirane acrylic beads. The immobilized lipoxygenase exhibited increased long-term stability without a significant modification of the kinetic parameters. The comparative study on the effects of inhibitors such as dithizone, NDGA, phenidone, and beta-mercaptoethanol on the free and immobilized enzyme highlighted the importance of the lipoxygenase--support interaction, concluding that the immobilization process could cause the protection of the iron atom in the enzyme. The enzymatic specificity was maintained for the immobilized lipoxygenase, and their stability increased as compared to the free enzyme, making if feasible to use the enzyme in a multistep reaction to produce large quantities of leukotriene A4 or other related compounds of interest in the chemical industry and medicine.

Hemolysins and verotoxin (VT) in enteric Escherichia coli isolated from pigs.

One hundred and three E. coli strains isolated from the intestinal contents of pigs were examined for hemolysis and verotoxin production on Vero monolayer cells. Hemolysins were produced by 18 (17.5%) strains;--hemolysin was produced by 6 strains of which 4 belonged to serotype O149:K91, K88ac;--hemolysin was produced by 8 strains which could no be serotyped; 1 strain produced-hemolysin and possessed fimbrial antigens K88; the remaining 3 strains were enterohemolytic and VT producers. Among the 85 non-hemolytic strains, 11 showed some antigenic properties. Only 3 could be serotyped (O64:K 'V142'; O157:K 'V17' and O149:K91); 4 had fimbrial antigens K88 and 1 strain was K99, and 3 possessed capsular antigen (K89). According to these results it is possible to conclude that both hemolytic and non-hemolytic E. coli strains could be pathogenic.

Chloracne in the 1990s.

BACKGROUND: Chloracne is a disease associated with toxicity of halogenated compounds used in some industrial processes. A patient affected by chloracne led us to study a total of nine cases from a single factory. METHODS: We studied the clinical features of nine patients exposed chronically to chlorobenzenes. On all of them blood samples were drawn and biopsies of affected skin and liver were taken. Their work environment was visited and studied. RESULTS: All nine patients were men and had polymorphic skin lesions, characterized mainly by comedones and cysts. They had chronic conjunctivitis and seven had cysts in the Meibomian glands. All of them had polyneuropathy and liver damage and seven had hypertriglyceridemia. Compounds known to cause chloracne were found in exceedingly high concentrations in the water used in the workplace. CONCLUSIONS: Every patient exposed to halogenated compounds with the cutaneous manifestations of chloracne should be carefully investigated for systemic complications (such as ophthalmic, neuropathic, hepatic, and lipoprotein abnormalities).

Hemin and hemeprotein bleaching during linoleic acid oxidation by lipoxygenases.

Hemin and hemoglobin are bleached by lipoxygenases, type 1 (from soybean) or type 2 (from platelets), during linoleic acid oxidation. This process has been found to be related to the inhibition of the lipoxygenase activity, measured as hydroperoxide generation and to produce oxodienes as well. All these parameters have been determined simultaneously from measurements of the absorbance at 234, 285, 375 and 410 nm to detect hydroperoxides, oxodienes, hemin and hemoglobin, respectively, using a diode array spectrophotometer. The inhibition of lipoxygenase activity by these pigments has been found to be competitive with linoleic acid, showing an increase of 4-7-fold of the Km value of linoleic acid in the presence of concentrations of hemin and hemoglobin as low as 0.2 and 0.02 microM, respectively, for the case of platelet lipoxygenase activity. The concentrations of hemin and of hemoglobin producing the inhibition of 50% of lipoxygenase activity are: 0.25 and 0.02 microM for the platelet isoenzyme, and 1.4 and 0.18 microM for the soybean isoenzyme, respectively. From the quenching of the intrinsic fluorescence of soybean lipoxygenase activity by hemin, we have obtained a dissociation constant of hemin-soybean lipoxygenase of 0.5 microM. The results obtained in this paper for the cooxidation process of hemin and hemoglobin by lipoxygenase can be rationalized in terms of hemin binding at or near to the catalytic center, resulting in a lesser binding of linoleic acid and an enhanced release of radicals, and pigment bleaching by radicals and lipid hydroperoxides.

Local anesthetic-divalent cation binding center interaction.

This communication explicitly considers the possibility that local anesthetics interact with divalent cation binding centers, such as chlortetracycline, quin 2, ethyleneglycol bis (B-aminoethyl ether)-N-N,N',N'-tetraacetic acid (EGTA), ethylenediamine tetraacetic acid (EDTA) and ATP. Alterations of local anesthetic fluorescence spectra have been found in the presence of EGTA, EDTA and ATP. On the other hand, the fluorescence of chlortetracycline is enhanced and that of quin 2 is quenched by local anesthetics. The spectrofluorometric evidence presented in this paper clearly indicates that local anesthetics and these divalent cation chelators interact in solution. The fluorescence alterations observed do not derive from parallel changes of their respective absorption spectra, thus, they appear to be due to quantum yield changes. On the basis of the spectral perturbations observed, it is likely that local anesthetics interact with M2+ binding centers via their electron defective aromatic ring. From the association constants obtained in this study, we make an estimation of the free energy of this interaction ranging from -2.8 to -4.0 kcal/mole in the following experimental conditions: pH 7.4 at an ionic strength of 0.1 at 25 degrees. The relevance of these results to define the physical-chemical characteristics of the local anesthetic receptor site is briefly discussed. It is suggested that local anesthetics can bind strongly to Ca2+ and Mg2+ binding centers, provided that a hydrophobic region is located nearby.

Comparative fluorescence properties of lipoxygenases.

1. Lipoxygenases purified from tomato, rat liver and soybean show a fluorescence band centered at 648 nm, which is likely to derive from Tyr and Trp. 2. The intensity of this fluorescence range from 0.7 to 1.0% of the intensity of their major intrinsic fluorescence band (lambda max = 343 nm) in all these lipoxygenases. 3. At inhibitory concentrations, ditizone partly quenches the fluorescence of the lipoxygenases above 600 nm. 4. Saturating concentrations of linoleic acid produce 79% quenching of the fluorescence at 648 nm of soybean lipoxygenase inactivated by treatment with 1 mM dithiothreitol. From these data we have obtained an apparent Kd for linoleic acid-lipoxygenase complex dissociation of 34 +/- 3 microM. 5. It is suggested that the fluorescence above 600 nm reveals the presence of aromatic amino acids located near or at the catalytic center.