Correction: An impedimetric immunosensor for diagnosis of Brazilian spotted fever in blood plasma.

Correction for 'An impedimetric immunosensor for diagnosis of Brazilian spotted fever in blood plasma' by Marx Osório Araújo Pereira et al., Anal. Methods, 2024, https://doi.org/10.1039/d3ay01308a.

An impedimetric immunosensor for diagnosis of Brazilian spotted fever in blood plasma.

Brazilian spotted fever (BSF) is a serious disease of medical importance due to its rapid evolution and high lethality. The effectiveness of the treatment mainly depends on the rapid diagnosis, which is currently performed by indirect immunofluorescence and PCR tests, which require high costs and laboratory structure. In order to propose an alternative methodology, we sought to develop an impedimetric immunosensor (IM) based on the immobilization of specific IgY antibodies for IgG anti Rickettsia rickettsii, using blood plasma from capybara (Hydrochoerus hydrochaeris), for characterization, validation and applications of the ready IM. IM selectivity was observed when comparing capybara reagent IgG (IgGcr) readings with non-reagent IgG (IgGnr). A reagent IgG calibration curve was obtained, from which the limits of detection (LOD) and quantification (LOQ) of 1.3 ng mL-1 and 4.4 ng mL-1 were calculated, respectively. The accuracy tests showed that different concentrations of IgGcr showed a maximum deviation of 20.0%, with CI between 90.00% and 95.00%. Intermediate precision tests showed a relative standard deviation of 2.09% for researcher 1 and 2.61% for researcher 2, and the F test showed no significant difference between the recovery values found between the two analysts, since Fcal 1.56 < 5.05 and P-value 0.48 > 0, 05. Therefore, an impedimetric immunosensor was developed to detect anti BSF IgG in capybara blood plasma, which greatly contributes to the improvement of diagnostic tests, cost reduction and ease of execution.

LQFM289: Electrochemical and Computational Studies of a New Trimetozine Analogue for Anxiety Treatment.

This study employs electrochemical and Density Functional Theory (DFT) calculation approaches to investigate the potential of a novel analogue of trimetozine (TMZ) antioxidant profile. The correlation between oxidative stress and psychological disorders indicates that antioxidants may be an effective alternative treatment option. Butylatedhydroxytoluene (BHT) is a synthetic antioxidant widely used in industry. The BHT-TMZ compound derived from molecular hybridization, known as LQFM289, has shown promising results in early trials, and this study aims to elucidate its electrochemical properties to further support its potential as a therapeutic agent. The electrochemical behavior of LQFM289 was investigated using voltammetry and a mechanism for the redox process was proposed based on the compound's behavior. LQFM289 exhibits two distinct oxidation peaks: the first peak, Ep1a ≈ 0.49, corresponds to the oxidation of the phenolic fraction (BHT), and the second peak, Ep2a ≈ 1.2 V (vs. Ag/AgCl/KClsat), denotes the oxidation of the amino group from morpholine. Electroanalysis was used to identify the redox potentials of the compound, providing insight into its reactivity and stability in different environments. A redox mechanism was proposed based on the resulting peak potentials. The DFT calculation elucidates the electronic structure of LQFM289, resembling the precursors of molecular hybridization (BHT and TMZ), which may also dictate the pharmacophoric performance.

DNA-Based Electrodes and Computational Approaches on the Intercalation Study of Antitumoral Drugs.

The binding between anticancer drugs and double-stranded DNA (dsDNA) is a key issue to understand their mechanism of action, and many chemical methods have been explored on this task. Molecular docking techniques successfully predict the affinity of small molecules into the DNA binding sites. In turn, various DNA-targeted drugs are electroactive; in this regard, their electrochemical behavior may change according to the nature and strength of interaction with DNA. A carbon paste electrode (CPE) modified with calf thymus ds-DNA (CPDE) and computational methods were used to evaluate the drug-DNA intercalation of doxorubicin (DOX), daunorubicin (DAU), idarubicin (IDA), dacarbazine (DAR), mitoxantrone (MIT), and methotrexate (MTX), aiming to evaluate eventual correlations. CPE and CPDE were immersed in pH 7 0.1 mM solutions of each drug with different incubation times. As expected, the CPDE response for all DNA-targeted drugs was higher than that of CPE, evidencing the drug-DNA interaction. A peak current increase of up to 10-fold was observed; the lowest increase was seen for MTX, and the highest increase for MIT. Although this increase in the sensitivity is certainly tied to preconcentration effects of DNA, the data did not agree entirely with docking studies, evidencing the participation of other factors, such as viscosity, interfacial electrostatic interactions, and coefficient of diffusion.

Salivary nitrite and systemic biomarkers in obese individuals with periodontitis submitted to FMD.

The objective of this 9-month clinical study is to assess the impact of one-stage full-mouth disinfection (FMD) on salivary nitrite levels and systemic biomarkers and its correlation with total subgingival bacterial load in obese and non-obese patients with periodontitis. In total, 94 patients (55 obese and 39 non-obese) were initially evaluated, seven were lost during follow-up, resulting in 87 individuals at the end of the study. Outcomes were assessed at baseline, 3, 6, and 9 months post periodontal treatment by FMD. Salivary nitrite levels were determined using Griess reagent. Blood samples were collected to determine C-Reactive Protein (CRP), alkaline phosphatase and fasting blood glucose. Real-time PCR was used to determine the total subgingival bacterial load. FMD protocol resulted in increased salivary nitrite levels at 6- and 9-months post-treatment in the non-obese group (p<0.05). In obese individuals, FMD treatment led to an increase in salivary nitrite levels at 6 months (p<0.05); however, at 9 months, the nitrite levels returned to baseline levels. For both groups, the highest nitrite values were observed at 6 months. In addition, in both groups, FMD was associated with a decrease in biomarkers related to systemic inflammation and cardiovascular diseases, such as CRP (p<0.05) and alkaline phosphatase (p<0.05), and had no impact on the fasting blood glucose. This study demonstrates that obese patients with periodontitis present similar salivary nitrite levels when compared with non-obese individuals. FMD protocol resulted in increases in salivary nitrite levels and was associated with a positive impact on systemic biomarkers, regardless of obesity status.

Salivary nitrite and systemic biomarkers in obese individuals with periodontitis submitted to FMD

Abstract The objective of this 9-month clinical study is to assess the impact of one-stage full-mouth disinfection (FMD) on salivary nitrite levels and systemic biomarkers and its correlation with total subgingival bacterial load in obese and non-obese patients with periodontitis. In total, 94 patients (55 obese and 39 non-obese) were initially evaluated, seven were lost during follow-up, resulting in 87 individuals at the end of the study. Outcomes were assessed at baseline, 3, 6, and 9 months post periodontal treatment by FMD. Salivary nitrite levels were determined using Griess reagent. Blood samples were collected to determine C-Reactive Protein (CRP), alkaline phosphatase and fasting blood glucose. Real-time PCR was used to determine the total subgingival bacterial load. FMD protocol resulted in increased salivary nitrite levels at 6- and 9-months post-treatment in the non-obese group (p<0.05). In obese individuals, FMD treatment led to an increase in salivary nitrite levels at 6 months (p<0.05); however, at 9 months, the nitrite levels returned to baseline levels. For both groups, the highest nitrite values were observed at 6 months. In addition, in both groups, FMD was associated with a decrease in biomarkers related to systemic inflammation and cardiovascular diseases, such as CRP (p<0.05) and alkaline phosphatase (p<0.05), and had no impact on the fasting blood glucose. This study demonstrates that obese patients with periodontitis present similar salivary nitrite levels when compared with non-obese individuals. FMD protocol resulted in increases in salivary nitrite levels and was associated with a positive impact on systemic biomarkers, regardless of obesity status.

Resumo O objetivo deste estudo clínico, é avaliar o impacto da desinfecção bucal completa (DBC) nos níveis de nitrito salivar e biomarcadores sistêmicos e sua correlação com a carga bacteriana subgengival total em pacientes obesos e não obesos com periodontite. No total, 94 pacientes (55 obesos e 39 não obesos) foram avaliados inicialmente, sete foram perdidos durante o estudo, resultando em 87 indivíduos ao final. Os resultados foram avaliados no início do estudo, 3, 6 e 9 meses após o tratamento periodontal por DBC. Os níveis de nitrito salivar foram determinados usando o reagente de Griess. Amostras de sangue foram coletadas para determinação da Proteína C Reativa (PCR), fosfatase alcalina e glicemia de jejum. A PCR em tempo real foi usada para determinar a carga bacteriana subgengival total. O protocolo de DBC resultou em níveis aumentados de nitrito salivar em 6 e 9 meses após o tratamento no grupo de não obesos (p <0,05). Em indivíduos obesos, o tratamento da DBC levou a um aumento nos níveis de nitrito salivar em 6 meses (p <0,05); no entanto, aos 9 meses, os níveis de nitrito voltaram aos níveis basais. Para ambos os grupos, os maiores valores de nitrito foram observados aos 6 meses. Além disso, em ambos os grupos, a DBC foi associada à diminuição dos biomarcadores relacionados à inflamação sistêmica e doenças cardiovasculares, como PCR (p <0,05) e fosfatase alcalina (p <0,05), e não teve impacto na glicemia de jejum. Este estudo demonstra que pacientes obesos com periodontite apresentam níveis de nitrito salivar semelhantes quando comparados a indivíduos não obesos. O protocolo de DBC resultou em aumentos nos níveis de nitrito salivar e foi associado a um impacto positivo nos biomarcadores sistêmicos, independentemente do status de obesidade.

Hybrid Routing, Modulation, Spectrum and Core Allocation Based on Mapping Scheme.

With the persistently growing popularity of internet traffic, telecom operators are forced to provide high-capacity, cost-efficient, and performance-adaptive connectivity solutions to fulfill the requirements and increase their returns. However, optical networks that make up the core of the Internet gradually reached physical transmission limits. In an attempt to provide new solutions emerged, the Space-Division Multiplexing Elastic Optical Network emerged as one of the best ways to deal with the network depletion. However, it is necessary to establish lightpaths using routing, modulation, spectrum, and core allocation (RMSCA) algorithms to establish connections in these networks. This article proposes a crosstalk-aware RMSCA algorithm that uses a multi-path and mapping scheme for improving resource allocation. The results show that the proposed algorithm decreases the blocking ratio by up to four orders of magnitude compared with other RMSCA algorithms in the literature.

Physicochemical Investigation of Psoralen Binding to Double Stranded DNA through Electroanalytical and Cheminformatic Approaches.

This work showcased the first physicochemical investigation of psoralen (PSO) binding to double stranded DNA (dsDNA) through electroanalytical methods. Results evidenced that PSO presents one non-reversible anodic peak at electric potential (Epa) ≈ 1.42 V, which is associated with its oxidation and the formation of an epoxide derivative. Moreover, PSO analytical signal (i.e., faradaic current) decreases linearly with the addition of dsDNA, while the electric potential associated to PSO oxidation shifts towards more positive values, indicating thence that dsDNA addition hinders PSO oxidation. These findings were corroborated by the chemoinformatic study, which evidenced that PSO intercalated noncovalently at first between base-pairs of the DNA duplex, and then irreversibly formed adducts with both DNA strands, leading up to the formation of a cross-link which bridges the DNA helix, which explains the linear dependence between the faradaic current generated by PSO oxidation and the concentration of DNA in the test-solution, as well as the dependence between Ep and the addition of dsDNA solution. Therefore, the findings herein reported evidence of the applicability of electroanalytical approaches, such as voltammetry in the study of DNA intercalating agents.

Electrochemical Characterization of Central Action Tricyclic Drugs by Voltammetric Techniques and Density Functional Theory Calculations.

This work details the study of the redox behavior of the drugs cyclobenzaprine (CBP), amitriptyline (AMP) and nortriptyline (NOR) through voltammetric methods and computational chemistry. Results obtained in this study show that the amine moiety of each compound is more likely to undergo oxidation at 1a at Ep1a ≈ 0.69, 0.79, 0.93 V (vs. Ag/AgCl/KClsat) for CBP, AMP and NOR, respectively. Moreover, CBP presented a second peak, 2a at Ep2a ≈ 0.98 V (vs. Ag/AgCl/KClsat) at pH 7.0. Furthermore, the electronic structure calculation results corroborate the electrochemical assays regarding the HOMO energies of the lowest energy conformers of each molecule. The mechanism for each anodic process is proposed according to electroanalytical and computational chemistry findings, which show evidence that the methods herein employed may be a valuable alternative to study the redox behavior of structurally similar drugs.

Voltammetric Evaluation of Diclofenac Tablets Samples through Carbon Black-Based Electrodes.

Diclofenac (DIC) is a non-steroidal anti-inflammatory drug of wide use around the world. Electroanalytical methods display a high analytical potential for application in pharmaceutical samples but the drawbacks concerning electrode fouling and reproducibility are of major concern. Henceforth, the aim of this work was to propose the use of alternative low-cost carbon black (CB) and ionic liquid (IL) matrix to modify the surface of pencil graphite electrodes (PGE) in order to quantify DIC in raw materials, intermediates, and final products, as well as in stability assays of tablets. The proposed method using CB+IL/PGE displayed good recovery (99.4%) as well as limits of detection (LOD) of 0.08 µmol L-1 and limits of quantification (LOQ) of 0.28 µmol L-1. CB+IL/PGE response was five times greater than the unmodified PGE. CB+IL-PGE stands as an interesting alternative for DIC assessment in different pharmaceutical samples.

Salivary arginase activity after mechanical-chemical therapy / Atividade de arginase salivar após tratamento mecânico-químico

Introduction: Salivary components can be used as biomarkers for diagnosing and monitoring oral diseases. There is evidence that one potential biomarker, arginase, is associated with the inflammatory processes of periodontal disease, and its enzymatic activity is reduced according to the improvement in the clinical parameters after treatment. Objective: The present study aimed to evaluate the salivary arginase activity in gingivitis and periodontitis patients treated with full-mouth mechanical procedures combined with the adjunctive use of essential oils or chlorhexidine mouthwash, respectively. Material and method: Twenty-six gingivitis and 16 periodontitis patients received complete periodontal examinations at the baseline and 3 months after therapy, in which the periodontal probing depth, clinical attachment loss, plaque index, and gingival index measurements were taken. At these same appointments, the salivary total protein level and salivary arginase activity were also established via spectrophotometry. Result: There were improvements in all of the clinical parameters (p < 0.05) evaluated from the baseline to 3 months in both groups. In addition, the salivary arginase activity and total protein levels were reduced after the gingivitis treatment. Conclusion: Similar to the clinical results, both therapeutic protocols positively affected the salivary arginase activity; however, further studies are necessary to clarify its potential as a salivary biomarker for periodontal monitoring.

Introdução: Componentes salivares podem ser usados como biomarcadores para diagnóstico e monitoramento de doenças orais. Há evidências de que um potencial biomarcador, arginase, está associado com os processos inflamatórios da doença periodontal, e após o tratamento sua atividade enzimática é reduzida em concordância com a melhora nos parâmetros clínicos. Objetivo: O presente estudo objetivou avaliar a atividade da arginase salivar em pacientes com gengivite e periodontite tratados com procedimentos mecânicos em estágio único combinados ao uso coadjuvante de enxaguatórios com óleos essenciais ou clorexidina, respectivamente. Material e método: Vinte e seis pacientes com gengivite e 16 pacientes com periodontite receberam exame periodontal completo antes e 3 meses após a terapia, em que mensurações de profundidade de sondagem, perda de inserção clínica, índice de placa e índice gengival foram realizadas. Nestas mesmas consultas os níveis de proteína total e a atividade de arginase salivar foram estabelecidos via espectrofotometria. Resultado: Todos os parâmetros clínicos melhoraram, em ambos os grupos, do exame inicial para o de 3 meses (p < 0,05). Adicionalmente, após tratamento para gengivite houve redução da atividade de arginase salivar e do nível de proteína total. Conclusão: Semelhante aos resultados clínicos, ambos os protocolos terapêuticos afetaram positivamente a atividade da arginase salivar; entretanto, estudos futuros são necessários para clarificar seu potencial como biomarcador salivar para o monitoramento periodontal.

Rapid responses of plants to temperature changes.

Temperature is one of the main environmental factors that affect plant metabolism. Considering that plants are sessile, their survival depends on the efficient activation of resistance responses to thermal stress. In this comprehensive review, we discuss recent work on rapid biochemical and physiological adjustments, herein referred to as those occurring during the first few hours or a few days after the beginning of the change in the ambient temperature. The short-term metabolic modulation after plant exposure to heat and cold, including chilling and freezing, is discussed. Effects on photosynthesis, cell membranes, antioxidant system, production of heat shock proteins and nitric oxide, as well as an overview of signaling events to heat or cold stress are presented. In addition, we also discuss the acclimation process that occurs when the plant acquires resistance to an increase or decrease in temperature, adjusting its homeostasis and steady-state physiology to the new temperatures. Finally, we present studies with tropical plants that aim at elucidating the effects of temperature and the identification of the resilience levels of these plants to the expected climate changes, and which seek the development of techniques for germplasm conservation of endangered species.

Evidence of metabolic microevolution of the limpet Nacella concinna to naturally high heavy metal levels in Antarctica.

The gastropod Nacella concinna is the most conspicuous macroinvertebrate of the intertidal zone of the Antarctic Peninsula and adjacent islands. Naturally high levels of copper and cadmium in coastal marine ecosystems are accumulated in N. concinna tissues. We aimed to study the effects of metal cations on N. concinna arginase in the context of possible adaptive microevolution. Gills and muscle had the highest argininolytic activity, which was concentrated in the cytosol in both tissues. Gills had the highest levels of arginase and may be involved in the systemic control of l-arginine levels. The relatively high argininolytic activity of the N. concinna muscular foot, with KM=25.3±3.4mmolL-1, may be involved in the control of l-arginine levels during phosphagen breakdown. N. concinna arginases showed the following preferences for metal cations: Ni2+>Mn2+>Co2+>Cu2+ in muscle and Mn2+>Cu2+ in gills. Cu2+ activation is a unique characteristic of N. concinna arginases, as copper is a potent arginase inhibitor. Cu2+ partly neutralized N. concinna arginase inhibition by Cd2+, worked synergistically in muscle arginase activation by Co2+ and neutralized muscle arginase activation by Ni2+. Mn2+ was able to activate muscle arginase in the presence of Fe3+ and Pb2+. The selection of arginases that are activated by Cu2+ and resistant to inhibition by Cd2+ in the presence of Cu2+ over evolutionary timescales may have favored N. concinna occupation of copper- and cadmium-rich niches.

High and Low Salt Intake during Pregnancy: Impact on Cardiac and Renal Structure in Newborns.

INTRODUCTION: Previous studies from our laboratory demonstrated that dietary salt overload and salt restriction during pregnancy were associated with cardiac and renal structural and/or functional alterations in adult offspring. The present study evaluated renal and cardiac structure and the local renin-angiotensin system in newborns from dams fed high-, normal- or low-salt diets during pregnancy. METHODS: Female Wistar rats were fed low- (LS, 0.15% NaCl), normal- (NS, 1.3% NaCl) or high- (HS, 8% NaCl) salt diets during pregnancy. Kidneys and hearts were collected from newborns (n = 6-8/group) during the first 24 hours after birth to evaluate possible changes in structure using stereology. Protein expression of renin-angiotensin system components was evaluated using an indirect enzyme-linked immunosorbent assay (ELISA). RESULTS: No differences between groups were observed in total renal volume, volume of renal compartments or number of glomeruli. The transverse diameter of the nuclei of cardiomyocytes was greater in HS than NS males in the left and right ventricles. Protein expression of the AT1 receptor was lower in the kidneys of the LS than in those of the NS and HS males but not females. Protein expression of the AT2 receptor was lower in the kidneys of the LS males and females than in those of the NS males and females. CONCLUSION: High salt intake during pregnancy induced left and right ventricular hypertrophy in male newborns. Salt restriction during pregnancy reduced the expression of renal angiotensin II receptors in newborns.

Nitrito salivar como indicador da condição periodontal: revisão de literatura / Salivary nitrite as periodontal status indicator: a literature review

Vários fatores biológicos têm sido estudados como biomarcadores da condição periodontal. O óxido nítrico (NO) faz parte de uma família de radicais livres envolvidos com a homeostasia, resposta imunológica, atividade cardiovascular e neurotransmissão. O NO pode ser produzido pelo organismo humano via óxido nítrico sintase (NOS) dependente ou via NOS independente. No mecanismo NOS independente a produção de NO envolve um ciclo entero-salivar de redução do nitrato (NO3-) em nitrito (NO2-) e a sua subsequente conversão em NO. Os estímulos inflamatórios presentes na doença periodontal também são capazes de induzir a formação de NO e há relatos na literatura de que o mesmo possa atuar interferindo na progressão da periodontite. No osso, assim como em outros tecidos, a produção de NO pode ser estimulada por lipopolisacarídeos (LPS) bacterianos. Nesse mecanismo tem sido sugerida uma importante participação das bactérias bucais. O objetivo deste trabalho foi avaliar por meio de revisão da literatura a relação do óxido nítrico, nitrato e nitrito com a condição periodontal e se procedimentos terapêuticos periodontais podem interferir com esses fatores. O óxido nítrico é um importante mediador de várias atividades biológicas. Os níveis de NO2- parecem estar aumentados na periodontite, comparativamente à gengivite e saúde gengival. Apesar da produção de NO ter um papel primário bactericida, é provável que essa produção em altas concentrações resulte em danos aos tecidos periodontais do hospedeiro. Nas lesões periodontais quantidades consideráveis de NO são geradas principalmente por macrófagos, neutrófilos polimorfonucleares, linfócitos e fibroblastos induzidos pelas citocinas e por LPS. A oferta dietética de NO3- influencia a síntese de NO e a produção de NO2-. Não está completamente elucidada a real influência do tratamento periodontal sobre os níveis de NO2.(AU)

Several biological factors have been studied as biomarkers of periodontal condition. Nitric oxide (NO) is part of a family of free radicals related to homeostasis, immunological response, cardiovascular activity, and neurotransmission. NO can be produced by human body via nitric oxide synthase (NOS) dependent or an pathway independent of NOS. In the independent pathway NO production involves an enterosalivary cycle by which nitrate (NO3-) is reduced to nitrite (NO2-) followed by its subsequent conversion to NO. The inflammatory stimuli present in periodontal disease are also able to induce the formation of NO and there are reports in the literature that the same may act by interfering on the progression of periodontitis. In bone, like other tissues, NOproduction may be stimulated by lipopolysaccharide (LPS) from bacteria. In this mechanism it has been suggested an important role of oral bacteria. The aim of this study was to evaluate through a literature review the relationship between NO, NO3- and NO2- and periodontal condition. Also whether periodontal therapeutic procedures can interfere in NO, NO3- and NO2- or not. NO is an important mediator in various biological activities. NO2- levels seem to be high in periodontitis when compared to gingivitis and gingival health. Although NOproduction has a bactericidal primary role, probably in high concentrations its production results in damage to host periodontal tissues. In periodontal lesions greater amounts of NO are generated primarily by macrophages, polymorphonuclear neutrophils, lymphocytes and fibroblasts and induced by cytokines and LPS. NO3-from diet influences the synthesis and production of NO and NO2-. It is not completely understood the real influence of periodontal treatment on the levels of NO2- (AU)

Metabolic responses of the Antarctic fishes Notothenia rossii and Notothenia coriiceps to sewage pollution.

The present study aimed to assess the sewage effects of the Brazilian Antarctic Station Comandante Ferraz, Admiralty Bay, King George Island, on the hepatic metabolism (energetic, antioxidant, and arginase levels) and levels of plasma constituents of two Antarctic fish species Notothenia rossii and N. coriiceps. The bioassays were conducted under controlled temperature (0 °C) and salinity (35 psu), exposing the fish for 96 h, to sewage effluent diluted in seawater to 0.5 % (v/v). Liver homogenates were tested for the specific activities of the enzymes glucose-6-phosphatase (G6Pase), glycogen phosphorylase (GPase), hexokinase, citrate synthase, lactate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, superoxide dismutase, glutathione reductase, catalase, and arginase. Plasma levels of glucose, triacylglycerides, cholesterol, total protein, albumin, chloride, magnesium, calcium, and inorganic phosphate were also determined. In N. rossii, the decrease in citrate synthase and the increase in G6Pase and GPase suggested that the sewage effluent activated glycogenolysis and hepatic gluconeogenesis, whereas is N. coriiceps, only G6Pase levels were increased. In N. rossii, sewage effluent induced hypertriglyceridemia without modulating glucose plasma levels, in contrast to N. coriiceps, which developed hypoglycemia without elevating plasma triglyceride levels. The decrease in glutathione reductase levels in N. coriiceps and in superoxide dismutase and catalase in N. rossii suggest that these two species are susceptible to oxidative stress stemming from the production of reactive oxygen species. An increase in magnesium in N. rossii and a decrease in N. coriiceps showed that sewage effluent compromised the control of plasma levels of this cation. Although phylogenetically close, both species of Antarctic fish exhibited different metabolic responses to the sewage effluent, with N. coriiceps showing greater susceptibility to the toxic effects of the pollutants. The present study suggests that the biochemical responses of these two species are potential indicators of metabolic changes caused by sewage effluents.

Interactions of temperature, salinity and diesel oil on antioxidant defense enzymes of the limpet Nacella concinna.

The intertidal and subtidal environments in the Antarctic Peninsula are vulnerable to pollutants, such as diesel oil, a commonly used fuel. Nacella concinna is capable of accumulating polycyclic aromatic hydrocarbons and is a potential biomonitor of diesel oil contamination. This work investigates the interaction of diesel oil, temperature and salinity on the activity of antioxidants enzymes defense of the gills, foot muscle and digestive glands. Upregulation of superoxide dismutase occurred in the three tissues by warming. The foot muscle catalase and the gill glutathione reductase were upregulated only by diesel. The inability to upregulate catalase and glutathione S-transferase in the digestive gland, as well as the increase of lipoperoxidation, suggested that this gland is more susceptible to the deleterious effects from oxidative stress.

Periodontal Therapy Effects on Nitrite Related to Oral Bacteria: A 6-Month Randomized Clinical Trial.

BACKGROUND: Nitrite is a biologic factor relevant to oral and systemic homeostasis. Through an oral bacteria reduction process, it was suggested that periodontal therapy and chlorhexidine (CHX) rinse could affect nitrite levels, leading to negative effects, such as an increase in blood pressure. This 6-month randomized clinical trial evaluated the effects of periodontal therapeutic protocols on salivary nitrite and its relation to subgingival bacteria. METHODS: One hundred patients with periodontitis were allocated randomly to debridement procedures in four weekly sections (quadrant scaling [QS]) or within 24 hours (full-mouth scaling [FMS]) in conjunction with a 60-day CHX (QS + CHX and FMS + CHX), placebo (QS + placebo and FMS + placebo), or no mouthrinse (QS + none and FMS + none) use. Real-time polymerase chain reaction determined total bacterial, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Streptococcus oralis, and Actinomyces naeslundii levels. Salivary nitrite concentration was determined with Griess reagent. Data were analyzed statistically at baseline and 3 and 6 months by analysis of variance, Kruskal-Wallis, Mann-Whitney U, and Spearman correlation tests (P <0.05). RESULTS: Nitrite concentrations did not tend to change over time. Regarding CHX use, there was a negative correlation between nitrite and total bacterial load at 6 months (FMS + CHX) and one positive correlation between P. gingivalis and nitrite at baseline (QS + CHX). Independently of rinse type, in the FMS group, nitrite correlated negatively with several microbial parameters and also with a higher percentage of deep periodontal pockets. CONCLUSIONS: The relationship between nitrite and bacterial levels appears weak. Short-term scaling exhibited a greater influence on nitrite concentrations then long-term CHX use.

Effect of temperature acclimation on the liver antioxidant defence system of the Antarctic nototheniids Notothenia coriiceps and Notothenia rossii.

The aim of this study was to determine whether endemic Antarctic nototheniid fish are able to adjust their liver antioxidant defence system in response to the temperature increase. The activity of the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) enzymes as well as the content of non-enzymatic oxidative stress markers such as reduced glutathione (GSH), lipid peroxidation (LPO) and protein carbonyl (PC) were measured in the liver of two Antarctic fish species, Notothenia rossii and Notothenia coriiceps after 1, 3 and 6days of exposure to temperatures of 0°C and 8°C. The GST activity showed a downregulation in N. rossii after 6days of exposure to the increased temperature. The activity profiles of GST and GR in N. rossii and of GPx in N. coriiceps also changed as a consequence of heating to 8°C. The GSH content increased by heating to 8°C after 3days in N. coriiceps and after 6days in N. rossii. The content of malondialdehyde (MDA), a LPO marker, showed a negative modulation by the heating to 8°C in N. rossii after 3days of exposure to temperatures. Present results show that heating to 8°C influenced the levels and profiles of the antioxidant enzymes and defences over time in the nototheniid fish N. rossii and N. coriiceps.

Reduction of salivary arginine catabolic activity through periodontal therapy.

OBJECTIVE: Salivary enzymes may be used to diagnose periodontal conditions. Salivary arginase activity (SAA) is related to susceptibility to bacterial infection. Therefore, the aim of this controlled interventional study was to determine the SAA before and after non-surgical periodontal therapy. METHOD AND MATERIALS: Eighty-nine subjects were selected: 31 periodontally healthy patients (controls), 27 gingivitis patients, and 31 chronic periodontitis patients. Plaque and Gingival Indices, probing depth, and clinical attachment level were monitored. The presence of Campylobacter rectus, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Prevotella intermedia was evaluated by polymerase chain reaction. Salivary total protein level and SAA were also established by spectrophotometry. Clinical and arginase data were analyzed using the Wilcoxon, Mann-Withney, and Kruskal-Wallis tests (P < .05). For microbial data, the chi-square test was used. The Pearson correlation test was also used between each parameter evaluated. RESULTS: After therapy, due to a significant reduction in SAA, the values observed for the gingivitis and periodontitis groups were similar to those found in the healthy group. Interestingly, after therapy, SAA followed the same positive pattern showed by the overall improvement of clinical parameters (gingivitis and periodontitis groups mean values, pre- > posttherapy) and by the reduction of target pathogens (gingivitis group T forsythia, pre- > posttherapy; periodontitis group P. gingivalis, T. denticola, P. intermedia, and T. forsythia, pre- > posttherapy). CONCLUSION: Based on the reduction of SAA after therapy, in accordance with the expected reduction in clinical and microbiologic parameters, it was concluded that SAA has the potential to serve as a reliable method to access to the therapeutic response of chronic periodontitis subjects treated with nonsurgical periodontal therapy.