Cytotoxicity assays to evaluate tannery effluents treated by photoelectrooxidation.

The advanced oxidation process (AOP) is used to increase the treatment efficiency of effluents however, it is necessary to compare the toxicity of treated and untreated effluents to evaluate if the decontamination process does not cause any biological harm. Cultured cells have been previously used to assess the genotoxic and cytotoxic potential of various compounds. Hence, the aim of this work was to assess the applicability of cytotoxicity assays to evaluate the toxicity related to the AOP treatment. Samples of an industrial effluent were collected after their treatment by a conventional method. Cytotoxicity of standard and AOP treated effluents was assessed in CRIB and HEp-2 cell line using the MTT and neutral red assays. We observed decrease at cell viability in the both assays (50% MTT and 13% NRU) when cells were exposed to the AOP treatment in the highest concentration. Thus, cytotoxic assays in cultured cells can be explored as an useful method to evaluate toxicity as well as to optimize effluents treatment process.

Cytotoxicity assays to evaluate tannery effluents treated by photoelectrooxidation / Ensaios de citotoxicidade na avaliação de efluentes de curtume tratados por fotoeletrooxidação

The advanced oxidation process (AOP) is used to increase the treatment efficiency of effluents however, it is necessary to compare the toxicity of treated and untreated effluents to evaluate if the decontamination process does not cause any biological harm. Cultured cells have been previously used to assess the genotoxic and cytotoxic potential of various compounds. Hence, the aim of this work was to assess the applicability of cytotoxicity assays to evaluate the toxicity related to the AOP treatment. Samples of an industrial effluent were collected after their treatment by a conventional method. Cytotoxicity of standard and AOP treated effluents was assessed in CRIB and HEp-2 cell line using the MTT and neutral red assays. We observed decrease at cell viability in the both assays (50% MTT and 13% NRU) when cells were exposed to the AOP treatment in the highest concentration. Thus, cytotoxic assays in cultured cells can be explored as an useful method to evaluate toxicity as well as to optimize effluents treatment process.

Resumo O processo de oxidação avançada (POA) tem sido usado para aumentar a eficiência do tratamento de efluentes; no entanto, é necessário comparar a toxicidade de efluentes tratados e não tratados para avaliar se o processo de descontaminação não é capaz de causar algum risco biológico. Cultivos celulares têm sido utilizados para avaliar o potencial genotóxico e citotóxico de vários compostos. Assim, o objetivo deste trabalho foi avaliar a aplicabilidade de ensaios de citotoxicidade para avaliar a toxicidade relacionada ao tratamento com POA. As amostras de um efluente industrial foram recolhidas após o tratamento por um método convencional. A citotoxicidade dos efluentes padrão e tratado com POA foi avaliada nas linhagens celulares CRIB e HEp-2 usando os ensaios do MTT e do vermelho neutro. Observou-se diminuição da viabilidade celular em ambos os ensaios (50% MTT e 13% VN) quando as células foram expostas à concentração mais elevada do efluente tratado com POA. Assim, os ensaios de citotoxicidade em cultivos celulares podem ser explorados como um método útil para avaliar a toxicidade, bem como para otimizar os processos de tratamento de efluentes.

Cytotoxicity assays to evaluate tannery effluents treated by photoelectrooxidation

The advanced oxidation process (AOP) is used to increase the treatment efficiency of effluents however, it is necessary to compare the toxicity of treated and untreated effluents to evaluate if the decontamination process does not cause any biological harm. Cultured cells have been previously used to assess the genotoxic and cytotoxic potential of various compounds. Hence, the aim of this work was to assess the applicability of cytotoxicity assays to evaluate the toxicity related to the AOP treatment. Samples of an industrial effluent were collected after their treatment by a conventional method. Cytotoxicity of standard and AOP treated effluents was assessed in CRIB and HEp-2 cell line using the MTT and neutral red assays. We observed decrease at cell viability in the both assays (50% MTT and 13% NRU) when cells were exposed to the AOP treatment in the highest concentration. Thus, cytotoxic assays in cultured cells can be explored as an useful method to evaluate toxicity as well as to optimize effluents treatment process.

Resumo O processo de oxidação avançada (POA) tem sido usado para aumentar a eficiência do tratamento de efluentes; no entanto, é necessário comparar a toxicidade de efluentes tratados e não tratados para avaliar se o processo de descontaminação não é capaz de causar algum risco biológico. Cultivos celulares têm sido utilizados para avaliar o potencial genotóxico e citotóxico de vários compostos. Assim, o objetivo deste trabalho foi avaliar a aplicabilidade de ensaios de citotoxicidade para avaliar a toxicidade relacionada ao tratamento com POA. As amostras de um efluente industrial foram recolhidas após o tratamento por um método convencional. A citotoxicidade dos efluentes padrão e tratado com POA foi avaliada nas linhagens celulares CRIB e HEp-2 usando os ensaios do MTT e do vermelho neutro. Observou-se diminuição da viabilidade celular em ambos os ensaios (50% MTT e 13% VN) quando as células foram expostas à concentração mais elevada do efluente tratado com POA. Assim, os ensaios de citotoxicidade em cultivos celulares podem ser explorados como um método útil para avaliar a toxicidade, bem como para otimizar os processos de tratamento de efluentes.

Extracellular DNA traps in bronchoalveolar fluid from a murine eosinophilic pulmonary response.

Asthma is associated with a loss of the structural integrity of airway epithelium and dysfunction of the physical barrier, which protects airways from external harmful factors. Granulocyte activation causes the formation of extracellular traps, releasing web-like structures of DNA and proteins, being important to kill pathogens extracellularly. We investigated whether eosinophils infiltrating airways in an experimental model of asthma would induce eosinophil extracellular traps (EETs) in bronchoalveolar lavage fluid and lung tissue. We showed that an ovalbumin (OVA) asthma protocol presented a significant increase in eosinophil counts with increased extracellular DNA in bronchoalveolar lavage fluid as well as in lung tissue, confirming the presence of DNA traps colocalized with eosinophil peroxidase. EETs formation was reversed by DNase treatment. With these approaches, we demonstrated for the first time that OVA-challenged mice release extracellular DNA traps, which could aggravate pulmonary dysfunction.

Contradirectional couplers in silicon-on-insulator rib waveguides.

We demonstrate contradirectional couplers in silicon-on-insulator rib waveguides using a CMOS compatible technology, in which a periodic dielectric perturbation is introduced in the coupling region between two different-sized rib waveguides. This structure enables high fabrication tolerances for narrow-bandwidth add-drop filters, using commercially available deep-ultraviolet lithography, that do not suffer from having a free spectral range. The simulation using coupled-mode theory and mode-profile calculations shows good agreement with experiment. A narrow bandwidth of 0.35 nm and a low loss of less than 1 dB have been achieved experimentally.

Fractures of the scapula.

The scapula connects the arm with the chest wall and is therefore of great importance for a free range of shoulder of motion. For a long-term scapular fractures had been treated predominantly conservative. However, clinical studies of the past decades revealed that some fracture patterns deserve operative treatment to prevent unfavorable functional outcome and chronic state of pain. Scapular fractures are predominantly acquired during high-energy trauma and these patients' presents with a mean of 3.9 associated injuries in the emergency department. Injuries to the head, chest and ipsilateral upper extremity are most common. As some of these injuries are possibly life threatening they are treated first. Scapular fractures are only very seldom surgical emergencies. Therefore they are treated during the phase of reconvalescence in polytraumatized patients. Decision-making should be based on a thoroughgoing diagnostics, including conventional x-rays and a CT-scan, epically in cases of glenoid neck or cavity fractures. All fracture patterns should be identified to there full extend and put into the context of the scapular suspensory complex. The OTA lately presented a new and comprehensive system for classification of the scapular fractures. It is divided in two levels. Level one for the general orthopedic or trauma surgeon and Level two for the advanced upper Extremity or Shoulder surgeon. This classification scheme allows an easy access to understanding of the severity and prognostics of scapular fractures. As a general guideline surgery is indicated if a double disruption of the Scapula suspensory system, a relevant malposition or dysintegrity of the glenoid (articular surface) or a displacement of the lateral column is present.

Co-entrapment of Trichoderma harzianum and Glomus sp. within alginate beads: impact on the arbuscular mycorrhizal fungi life cycle.

AIMS: This study was performed to explore the compatibility and applicability of plant beneficial micro-organisms (i.e. Trichoderma harzianum MUCL 29707 and Glomus sp. MUCL 41833) co-entrapped in alginate beads. METHODS AND RESULTS: Spores of Glomus sp. and conidia of T. harzianum were immobilized in alginate beads and the impacts of the saprotrophic fungi on the presymbiotic and symbiotic phase of the arbuscular mycorrhizal (AM) fungi evaluated under strict in vitro culture conditions. Our results demonstrated the capacity of both micro-organisms in combination to regrowth outside the calcium alginate coating. The presence of T. harzianum did not hinder the AM fungal development but rather stimulated its spore production and fitness. CONCLUSIONS: The combination of T. harzianum MUCL 29707 with Glomus sp. MUCL 41833 in alginate beads may represent a reliable alternative inoculum formulation for application in sustainable agriculture. SIGNIFICANCE AND IMPACT OF THE STUDY: The entrapment in the alginate beads of two fungi (i.e. a saprotroph and a symbiont) having beneficial effects on plants represents a promising formulation for the development of inoculants adapted to field application.

Hexagonal micron scale pillars influence epithelial cell adhesion, morphology, proliferation, migration, and cytoskeletal arrangement.

A desirable attribute of implants penetrating epithelium is the inhibition of downward epithelial migration. Simple grooved topographies can inhibit this migration either directly or indirectly by promoting connective tissue attachment, but few studies have focused on the direct effect of geometrically complex topographies on epithelial behavior. Therefore, we examined the influence of novel topographies comprising square floors surrounded by six-sided pillars on periodontal ligament epithelial cell adhesion, morphology, cytoskeletal organization, and migration. Relative to cells on smooth surface, epithelial cells on the pillar substrata adhered closely, exhibited reduced proliferation, had a reduced velocity, but higher persistence. Vinculin staining demonstrated that cells formed mature adhesions on the pillar tops, but smaller punctate adhesion in the gaps and on the pillar walls. Overall more mature adhesions were found on pillars compared to smooth surfaces, which may account for the reduced speed of migration limited on the pillars. F-actin stress fibers were predominantly found on pillar tops within 6 h, whereas microtubules (MTs) had a tendency to form in the gaps between the six-sided pillars. In conclusion, microfabricated pillars altered epithelial migration in ways that could prove useful in inhibition of epithelial downward migration on transmucosal implants.

Identification of the intermittency-I route to chaos in oscillating CO oxidation on zeolite-supported Pd.

For the oscillating oxidation of CO on a zeolite-supported palladium catalyst the transition to chaos could be observed in a very narrow region of the CO concentration in the feed. The reaction was carried out under the conditions of a continuous stirred tank reactor. A careful choice of the method for time series analysis led to the unambiguous identification of the intermittency-I route to chaos in the catalytic system despite the rather limited number of data points which can be acquired under normal pressure conditions. The route to chaos could be derived from the variation of the Fourier spectrum and the Poincare section as a function of the CO concentration in the feed. The embedding dimensions for the observed chaotic attractors of dE > or = 10 are much higher than the embedding dimensions obtained during UHV single crystal studies. High embedding dimensions indicate that the dynamic behaviour of the system has to be simulated with a distributed model which describes the collective behaviour of many Pd particles in the zeolite crystallite.

Identification of a highly conserved sequence at the N-terminus of the epithelial Na+ channel alpha subunit involved in gating.

The epithelial Na+ channel (ENaC) is responsible for Na+ reabsorption in aldosterone target tissues such as distal nephron and colon. ENaC is a heterotetramer composed of three homologous subunits, alpha, beta, and gammaENaC. Mutations leading to loss of function or reduced channel activity have been identified in all three subunits in patients with pseudohypoaldosteronism type-1. One missense mutation substituting a glycine (G95S) which is completely conserved throughout the gene family reduced ENaC open probability, Po. In this study we have performed systematic alanine substitutions of 28 residues of alphaENaC encompassing the glycine (G95). This screen identified a stretch of ten consecutive amino acids (alphaT92-alphaC101) which, when mutated, lead to a decrease in Na+ current (I(Na)) expressed with no significant changes in channel surface expression. This inhibitory effect was strongest for G95 and for two additional highly conserved amino acids--H94 and R98. The R98A mutant led to an important reduction in channel Po with no change in single-channel conductance, indicating that the segment encompassing H94, G95 and R98 is involved in modulation of channel gating kinetics.

Functional expression of a pseudohypoaldosteronism type I mutated epithelial Na+ channel lacking the pore-forming region of its alpha subunit.

The autosomal recessive form of type I pseudohypoaldosteronism (PHA-I) is an inherited salt-losing syndrome resulting from diminution-of-function mutations in the 3 subunits of the epithelial Na+ channel (ENaC). A PHA-I stop mutation (alpha(R508stop)) of the ENaC alpha subunit is predicted to lack the second transmembrane domain and the intracellular COOH-terminus, regions of the protein involved in pore function. Nonetheless, we observed a measurable Na+ current in Xenopus laevis oocytes that coexpress the beta and gamma subunits with the truncated alpha subunit. The mutant alpha was coassembled with beta and gamma subunits and was present at the cell surface at a lower density, consistent with the lower Na+ current seen in oocytes with the truncated alpha subunit. The single-channel Na+ conductance for the mutant channel was only slightly decreased, and the appearance of the macroscopic currents was delayed by 48 hours with respect to wild-type. Our data suggest novel roles for the alpha subunit in the assembly and targeting of an active channel to the cell surface, and suggest that channel pores consisting of only the beta and gamma subunits can provide significant residual activity. This activity may be sufficient to explain the absence of a severe pulmonary phenotype in patients with PHA-I.

Sensitivity of fibroblasts and their cytoskeletons to substratum topographies: topographic guidance and topographic compensation by micromachined grooves of different dimensions.

Fibroblasts alter their shape, orientation, and direction of movement to align with the direction of micromachined grooves, exhibiting a phenomenon termed topographic guidance. In this study we examined the ability of the microtubule and actin microfilament bundle systems, either in combination with or independently from each other, to affect alignment of human gingival fibroblasts on sets of micromachined grooves of different dimensions. To assess specifically the role of microtubules and actin microfilament bundles, we examined cell alignment, over time, in the presence or absence of specific inhibitors of microtubules (colcemid) and actin microfilament bundles (cytochalasin B). Using time-lapse videomicroscopy, computer-assisted morphometry and confocal microscopy of the cytoskeleton we found that the dimensions of the grooves influenced the kinetics of cell alignment irrespective of whether cytoskeletons were intact or disturbed. Either an intact microtubule or an intact actin microfilament-bundle system could produce cell alignment with an appropriate substratum. Cells with intact microtubules aligned to smaller topographic features than cells deficient in microtubules. Moreover, cells deficient in microtubules required significantly more time to become aligned. An unexpected finding was that very narrow 0.5-microm-wide and 0.5-microm-deep grooves aligned cells deficient in actin microfilament bundles (cytochalasin B-treated) better than untreated control cells but failed to align cells deficient in microtubules yet containing microfilament bundles (colcemid treated). Thus, the microtubule system appeared to be the principal but not sole cytoskeletal substratum-response mechanism affecting topographic guidance of human gingival fibroblasts. This study also demonstrated that micromachined substrata can be useful in dissecting the role of microtubules and actin microfilament bundles in cell behaviors such as contact guidance and cell migration without the use of drugs such as cytochalasin and colcemid.

A mutation causing pseudohypoaldosteronism type 1 identifies a conserved glycine that is involved in the gating of the epithelial sodium channel.

Pseudohypoaldosteronism type 1 (PHA-1) is an inherited disease characterized by severe neonatal salt-wasting and caused by mutations in subunits of the amiloride-sensitive epithelial sodium channel (ENaC). A missense mutation (G37S) of the human ENaC beta subunit that causes loss of ENaC function and PHA-1 replaces a glycine that is conserved in the N-terminus of all members of the ENaC gene family. We now report an investigation of the mechanism of channel inactivation by this mutation. Homologous mutations, introduced into alpha, beta or gamma subunits, all significantly reduce macroscopic sodium channel currents recorded in Xenopus laevis oocytes. Quantitative determination of the number of channel molecules present at the cell surface showed no significant differences in surface expression of mutant compared with wild-type channels. Single channel conductances and ion selectivities of the mutant channels were identical to that of wild-type. These results suggest that the decrease in macroscopic Na currents is due to a decrease in channel open probability (P(o)), suggesting that mutations of a conserved glycine in the N-terminus of ENaC subunits change ENaC channel gating, which would explain the disease pathophysiology. Single channel recordings of channels containing the mutant alpha subunit (alphaG95S) directly demonstrate a striking reduction in P(o). We propose that this mutation favors a gating mode characterized by short-open and long-closed times. We suggest that determination of the gating mode of ENaC is a key regulator of channel activity.

Push-pull integrate-optics Mach-Zehnder interferometer with domain inversion in one branch.

We report on a push-pull integrated-optics Mach-Zehnder interferometer having one domain-inverted branch and one noninverted branch. It is fabricated in the c(+) side of a LiNbO(3) substrate. We achieve ferroelectric domain inversion in one branch of the waveguide by doping it more heavily with Ti than the other branch and by using a high-temperature treatment that raises the temperature above the doped Curie temperature of the one branch but not of the other. The cumulative electro-optic effect of the inverted branch is found to be opposite that in the noninverted branch when both are subjected to the same electric field.

Correlation of clinical signs with nerve conduction tests in the diagnosis of carpal tunnel syndrome.

In order to establish the need for nerve conduction studies, a prospective study has been performed on 112 patients with symptoms of carpal tunnel syndrome (172 symptomatic hands), seeking correlation with 11 clinical criteria taken either singly or in combination. Even when the patient presents with a typical clinical presentation of carpal tunnel syndrome the diagnosis is only confirmed electrophysiologically in 61% of cases. Analysis of the sensitivity and specificity of various clinical tests and diagnostic manoeuvres has shown their mediocre reliability in establishing the diagnosis with a sensitivity of 58% and a specificity of 54% for Phalen's test.

Size and status of metastases after inductive chemotherapy of germ-cell tumors. Indication for salvage operation.

Secondary resection of metastases remaining after inductive chemotherapy of advanced germ-cell tumors has thus far been obligatory. The absence of malignant components in one-third of all residual tumors and the high risk of the operation have led several authors to reconsider the criteria for this approach. In a retrospective study of 153 cases (127 evaluable) we investigated the histology of the primary tumor and the size of the residual tumor with regard to residual histology and outcome. Patients were divided into the following three groups according to the histology of the primary tumor: group I, pure seminoma (16 patients); group II, nonseminoma without teratoma (32 patients); and group III, nonseminoma with teratoma (79 patients). Among the 16 purely seminomatous tumors, the residual masses ranged from 2 to 12 cm; 12 consisted of necrotic tissue only, 3 contained malignant germ-cell elements, and 1 contained adult teratoma. The residuals of primarily teratoma-free nonseminomas measured 2-16 cm; the smallest residual tumor containing active malignant elements measured 4 cm, and the diameter of the largest necrotic residue was 6 cm. Four residuals contained mature teratoma. The size of residuals from teratomatous primary tumors was 3-24 cm; the smallest malignant tumor measured 5 cm, and the diameter of the largest purely necrotic mass was 8 cm. According to our results, a secondary operation may be omitted if the residual mass of a primary seminoma is smaller than 5 cm or if that of a primary nonseminoma without teratoma is less than 3 cm in diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Calculation of the effective index for nonguiding regions: reply to comment.

Here we point out that in their comment Bastiaansen et al. Appl. Opt. 33, this issue (1994)] overlooked both the context of and the assumptions in Jaeger and Lai's paper [Appl. Opt. 31, 7183-7190 (1992)]. This omission appears to have resulted in their applying the Jaeger and Lai method inappropriately to a particular rib waveguide structure, yielding strange results. Therefore we present the underlying theory and ad hoc a simple and theoretically consistent method for applying it to rib waveguides. We demonstrate that good results may be obtained for a weakly guiding rib waveguide structure when field separability may be assumed, i.e., one that better meets the assumptions; this structure was chosen because numerical results were available for comparison.

Integrated optics pockels cell-choice of crystal cut and waveguide orientation.

Several benefits are realized when one chooses az-propagating waveguide in a y-cut substrate of lithiumniobate for use in an integrated optics Pockels cell: (1)waveguide can be biased by controlling its length; (2) polarizationstate is nearly uniform over the entire outputplane of the waveguide; (3) temperature change does notsignificantly affect the bias of the waveguide; (4) opticaldamage is negligible; and (5) waveguide fabrication is very simple.