Evaluation and monitoring of the water quality of an Argentinian urban river applying multivariate statistics.

In this work, we present the water quality assessment of an urban river, the San Luis River, located in San Luis Province, Argentina. The San Luis River flows through two developing cities; hence, urban anthropic activities affect its water quality. The river was sampled spatially and temporally, evaluating ten physicochemical variables on each water sample. These data were used to calculate a Simplified Index of Water Quality in order to estimate river water quality and infer possible contamination sources. Data were statistically analyzed with the opensource software R, 4.1.0 version. Principal component analysis, cluster analysis, correlation matrices, and heatmap analysis were performed. Results indicated that water quality decreases in areas where anthropogenic activities take place. Robust inferential statistical analysis was performed, employing an alternative of multivariate analysis of variance (MANOVA), MANOVA.wide function. The most statistically relevant physicochemical variables associated with water quality decrease were used to develop a multiple linear regression model to estimate organic matter, reducing the variables necessary for continuous monitoring of the river and, hence, reducing costs. Given the limited information available in the region about the characteristics and recovery of this specific river category, the model developed is of vital importance since it can quickly detect anthropic alterations and contribute to the environmental management of the rivers. This model was also used to estimate organic matter at sites located in other similar rivers, obtaining satisfactory results.

Oregano Essential Oil Interactions with Photogenerated Singlet Molecular Oxygen.

Essential oils are a mixture of volatile compounds, products of the secondary metabolism of plants. Once extracted, they can be deteriorated losing their organoleptic and therapeutic properties due to various environmental factors, being light exposure in aerobic conditions the main cause. In this work, the oregano essential oil extraction and characterization from Origanum vulgare plants grown in the experimental field of the FTU-UNSL and its photodegradation in MeOH:H2 O 60:40 v/v solvent were studied. Characterization by EIMS and NIST Mass Spectrometry indicates the main compounds of oregano essential oil, quantified in the extracted oil by GC-MS, are carvacrol (7.14%) and thymol (47.37%). Degradation of essential oil and its two major components can be caused by reactive oxygen species photogenerated from endogenous sensitizers as riboflavin. Our results suggest degradation occurs involving singlet molecular oxygen. Interaction of carvacrol and thymol with singlet oxygen is mainly a physical process, while essential oil has an important reactive component, which indicates there might be other constituents which could contribute to reactive photoprotection. The effect of simultaneous presence of oregano essential oil and tryptophan amino acid-used as a photooxidizable model under riboflavin-photosensitizing conditions-was studied in order to evaluate the possible photoprotection exerted by the essential oil.

Experimental and Theoretical Study of the Stability of the Complex Fisetin-Cu(II) and A Comparative Study of Free Ligand and Complex Interaction with Molecular Singlet Oxygen.

In this work, the flavonol fisetin was selected in order to study its reactivity against Cu(II), a metal ion of interest in biological media and industry. The stoichiometry and apparent formation constant of the complex in ethanolic medium at 25°C were evaluated using spectrophotometric techniques. The resulting stoichiometry was a 1:1 ligand:metal complex, and a log K = 5.17 ± 0.12 was determined. Since two possible chelation sites can be proposed for the complex formation, quantum chemistry calculations were performed on these structures. Calculations suggest that the hydroxyl-keto site is more stable for the complex formation than the catechol site. Flavonoids could exert protection against oxidative damage caused by reactive oxygen species, and this biological activity could be affected by chelation with metal ions. This led us to perform a study on the interaction of both, free flavonoid and complex, with reactive oxygen species. Our results showed both compounds quench molecular singlet oxygen photogenerated with visible light, mainly in a physical fashion. In order to analyze a possible protective effect of flavonoid and its complex against oxidative damage in biological environments, the amino acid tryptophan was selected as a model oxidation system. Free flavonoid does not have a marked protective effect, whereas its complex showed a relevant protective effect.

From San Luis, A Few Words of Gratitude.

The Photochemical Research Group from San Luis (Argentina) highlights the contributions of Dr. Norman Andino García to the development of the group as a way to show him our gratitude for all his support.

Effect of Cu(2+)-complexation on the scavenging ability of chrysin towards photogenerated singlet molecular oxygen (O2((1)Δg)). Possible biological implications.

Visible-light irradiation of aqueous-ethanolic solutions of Riboflavin (Rf) in the individual presence of the flavone chrysin (Chr) and its complex with Cu(2+) ([Chr2Cu]; 2:1 L:M) generates singlet molecular oxygen O2((1)Δg), that concomitantly interact with both flavone derivatives. Overall (kt) and reactive (kr) rate constants in the order of 10(7)M(-1)s(-1) were determined for the process. Metal chelation greatly enhances the scavenging ability of [Chr2Cu] towards O2((1)Δg) through a mechanism dominated, in >80%, by the physical component. In this way, practically all O2((1)Δg) is deactivated by the complex without significant loss of the quencher. The isolated flavone quenches O2((1)Δg) in a prevailing reactive fashion. The very low value exhibited by [Chr2Cu] for the kr/kt ratio constitutes a positive quality for antioxidative protectors in biological media, where elevated local concentration and high reactivity of significant molecules make them initial targets for O2((1)Δg) aggression. Finally, two interesting properties in the field of free radicals scavenging by [Chr2Cu] must be mentioned. In first place metal chelation itself, in the obvious sense of free metal ion withdrawal from the oxidizable medium, prevents the initiation of a free radical-mediated oxidation processes through mechanisms of Fenton or lipid peroxidation. In addition, the incorporation of Cu adds to [Chr2Cu] the ability of a free radical scavenger, already described for similar Cu-chelate compounds. This collection of beneficial properties positions the complex as a remarkably promising bioprotector towards ROS-mediated oxidation. A quantification of the efficiency on the initial anti-oxidative effect exerted by Chr and [Chr2Cu] towards tryptophan was carried out. The amino acid is an archetypal molecular model, commonly employed to monitor oxidative degradation of proteinaceous media. It was efficiently photoprotected against O2((1)Δg)-mediated photooxidation by [Chr2Cu].

Scavenging of photogenerated ROS by Oxicams. Possible biological and environmental implications.

The profusely employed drugs Piroxicam (Piro), Tenoxicam (Teno) and Meloxicam (Melo) belonging to the non-steroidal antiinflammatory drug (NSAID) family of the Oxicams (Oxis) were studied in the frame of two specific conditions: (a) their ROS scavenging ability, in relation to a possible biological antioxidant action and (b) their photodegradability under environmental conditions, in the context of Oxi-contaminated waters. Singlet molecular oxygen (O2((1)Δg)) and superoxide radical anion (O2(-)) were photogenerated through Riboflavin (Rf, vitamin B2)-photosensitization in aqueous and aqueous-methanolic solutions in the presence of Oxi concentrations in the range 50-500 µM. The visible-light absorber vitamin is currently present in all types of natural waters and constitutes the most frequent endogenous photosensitizer in mammals. Hence, it was employed in order to mimic both natural sceneries of interest. All three Oxis quench O2((1)Δg) with rate constants in the order of 10(8)M(-1)s(-1) showing a significant photodegradation efficiency given by a dominant reactive fashion for deactivation of the oxidative species. Although this is not a desirable property in the context of photoprotection upon prolonged photoirradiation, constitutes in fact a promissory aspect for the degradation NSAIDs, in waste waters. Indirect evidence indicates that Melo is also oxidized through a O2(-)-mediated component. The simultaneous presence of Piro plus tryptophan or tyrosine under Rf-photosensitizing conditions, which has taken the amino acids as photooxidizable model residues in a proteinaceous environment, indicates that the NSAID induces a protection of the biomolecules against photodynamic degradation.

The employment of a removable chitosan-derivatized polymeric sensitizer in the photooxidation of polyhydroxylated water-pollutants.

The known O2((1)∆g)-sensitizer system Chitosan bounded Rose Bengal (CH-RB), with Rose Bengal (RB) immobilized by irreversible covalent bonding to the polymer Chitosan (CH), soluble in aquous acidic medium, was employed in the photodegradation of three tri-hydroxy benzene water-contaminants (THBs). The system sensitizes the O2((1)∆g)-mediated photodegradation of THBs by a process kinetically favored, as compared to that employing free RB dissolved in the same solvent. Additionally the free xanthene dye, degradable by O2((1)∆g) through self-sensitization upon prolonged light-exposure, is considerably protected when bonded to CH-polymer. The polymeric sensitizer, totally insoluble in neutral medium, can be removed from the solution after the photodegradative cycle by precipitation through a simple pH change. This fact constitutes an interesting aspect in the context of photoremediation of confined polluted waters. In other words, the sensitizing system could be useful for avoiding to dissolve dyestuffs in the polluted waters, in order to act as conventional sunlight-absorbing dye-sensitizers. In parallel the interaction CH-O2((1)∆g) in acidic solution was evaluated. The polymer quenches the oxidative species with a rate constant 2.4 × 10(8) M(-1) s(-1) being the process mostly attributable to a physical interaction. This fact promotes the photoprotection of the bonded dye in the CH-RB polymer.

Quistes vellosos eruptivos con compromiso facial: presentación de un caso / Eruptive vellus hair cyst with facial involvement: case report

Los quistes vellosos eruptivos se presentan como lesiones de 1 a 4 mm, aspecto papular, color piel, rojizo a amarillento de etiología desconocida, localizados en tórax anterior o extremidades, con menor frecuencia pueden observarse en cara, cuello, abdomen y glúteos. Representan una patología poco frecuente derivada del infundíbulo piloso que puede ocurrir esporádicamente o ser heredada de forma autosómica dominante. Aunque su principal importancia radica en el diagnóstico diferencial, la dificultad en el manejo terapéutico es otro reto en esta entidad. Se presenta un caso de quistes vellosos eruptivos con compromiso extenso en el cual consideramos de interés peculiar, la localización facial.

Eruptive vellus hair cysts are papular lesions of 1-4 mm, skin color, reddish to yellowish, of unknown etiology, located on anterior chest or extremities. Less frequent locations may be seen on face, neck, abdomen and buttocks. It is an unusual condition resulting from hair infundibulum that may occur sporadically or being inherited in autosomal dominant manner. Although its main importance lies in the differential diagnosis, therapeutic approach is another challenge in this entity. A case of eruptive vellus cyst with extensive involvement is presented, emphasizing facial location of the lesions.

The NSAIDs indomethacin and diflunisal as scavengers of photogenerated reactive oxygen species.

Diflunisal (DFNS) and Indomethacin (IMTC) are two profusely employed NSAIDs that provide anti-inflammatory and analgesic effects in humans. The scavenging of reactive oxygen species (ROS) by both NSAIDs was systematically studied in pH 7 aqueous solution. The ROS O2 ((1)Δg), O2(•-) and H2O2, generated by visible light irradiation of Riboflavin (Rf) in the presence of DFNS and IMTC, are deactivated by the NSAIDs. The ROS scavenging action by both NSAIDs constitutes an interesting result and adds one more positive aspect to the beneficial actions attributed to these drugs. Nevertheless it should be taken into account that several NSAIDs, in particular IMTC, have been connected to the pathogenesis of gastric mucosal lesions, which in some cases includes ROS generating-ability. DFNS quenches ROS in a dominant physical fashion. It constitutes an excellent protective-antioxidant provided that is practically not destroyed/oxidized after the ROS scavenging action. IMTC, being also an efficient interceptor of ROS, belong to the so-called group of sacrificial-ROS quenchers: It is easily degraded by the oxidative species in the scavenging action. Although this property is negative in the context of prolonged ROS elimination, exhibits a promissory aspect for the degradation of pharmaceutical contaminants, such as NSAIDs, in waste waters.

A comparative photochemical study on the behavior of 3,3'-dihydroxyflavone and its complex with La(III) as generators and quenchers of reactive oxygen species.

A 1:1 complex between 3,3'-dihydroxyflavone (DHF) and La(III) (DHF-La(III)) is formed in methanolic solution with the relatively high apparent stability constant value of 2.3×10(6) and a calculated standard entropy change of 88.2 J mol(-1) K(-1), both at 25 °C. The photophysical properties of the complex and the free flavonoid are discussed in comparison to the well known related compound 3-hydroxyflavone. The ligand photogenerates O2((1)Δg) by energy transfer from its excited triplet state ((3)DHF(*)) to dissolved ground state oxygen, with a quantum yield of 0.13. (3)DHF(*) is quenched by La(III) with a rate constant close to the diffusion-controlled value. The respective abilities of the free flavonoid and DHF-La(III) as quenchers of the riboflavin-photogenerated reactive oxygen species singlet molecular oxygen (O2((1)Δg)) and superoxide radical anion (O2(-)) have been investigated. Both individual compounds were photoirradiated with visible light in the presence of the flavin as the only light-absorbing compound. A detailed kinetics and mechanistic study employing polarographic monitoring of oxygen uptake and time resolved detection of O2((1)Δg) phosphorescence indicates that DHF and the complex react with O2((1)Δg) and O2(-) by a non simple mechanism. The former deactivates O2((1)Δg) in a predominant physical fashion, a fact that constitutes a desirable property for antioxidants. It was found that metal chelation greatly enhances the ability of DHF as an overall O2((1)Δg) quencher.

On the generation and quenching of reactive-oxygen-species by aqueous vitamin B2 and serotonin under visible-light irradiation.

It is well known that endogenous daylight-absorbing compounds produce the sensitized photodegradation of biologically relevant substrates. In this context the photostability of a mixture of the indole neurotransmitter serotonin (Sero) and vitamin B2 (riboflavin, Rf) upon visible-light irradiation and the possible role of Sero and related compounds as generators or deactivators of reactive oxygen species (ROS) was investigated through a kinetic and mechanistic study. The work was done at pH 7 and under experimental conditions in which only the vitamin absorbs photoirradiation. Tryptamine (Trpa) and 5-hydroxyindole (OHIn) were included in the study as model compounds for the neurotransmitter. The visible light irradiation of aqueous Rf in the individual presence of Sero, Trpa and 5-OHIn, under aerobic conditions, induce degradative processes on the indole derivatives (In-der). At least two different mechanisms operate. Our analysis shows that the main reaction pathway is an electron-transfer-mediated quenching of triplet excited Rf ((3)Rf(*)) by the In-der. It produces the species Rf(-)/RfH() and the In-der radical cation that could react to form phenoxy and α-amino radicals. In a further reaction step the species O(2)(-) and OH() could be produced. In parallel, energy transfer from (3)Rf(*) to dissolved oxygen would generate O(2)((1)Δ(g)). Within the frame of the proposed mechanism, results suggest that Rf-sensitized degradation of Sero occurs via the mentioned ROS and non-oxygenated radical-mediated processes. The indole compound quenches O(2)((1)Δ(g)) in a dominant physical fashion. This fact constitutes a desirable property in antioxidants, provided that the quenching process practically does not eliminate the scavenger. Sero exerts a photoprotective effect towards tryptophan through the combined quenching of O(2)((1)Δ(g)) and (3)Rf(*), the latter excited species responsible for the generation of ROS. The amino acid can be taken as a target model of oxidizable biological substrates, particularly proteins.

Effects of simvastatin on cytokines secretion from mononuclear cells from critically ill patients with acute kidney injury.

PURPOSE: To assess the in vitro effects of simvastatin on IL-10 and TNF-α secretion from peripheral blood mononuclear cells (PBMC) of critically ill patients with and without acute kidney injury (AKI). METHODS: PBMC were collected from 63 patients admitted to the intensive care unit (ICU) and from 20 healthy controls. Patients were divided in 3 subgroups: with AKI, with sepsis and without AKI and with AKI and sepsis. After isolation by ficoll-gradient centrifugation cells were incubated in vitro with LPS 1 ng/mL, simvastatin (10(-8)M) and with LPS plus simvastatin for 24h. TNF-α and IL-10 concentrations on cells surnatant were determined by ELISA. RESULTS: Cells isolated from critically ill patients showed a decreased spontaneous production of TNF-α and IL-10 compared to healthy controls (6.7 (0.2-12) vs 103 (64-257) pg/mL and (20 (13-58) vs 315 (105-510) pg/mL, respectively, p<0.05). Under LPS-stimulus, IL-10 production remains lower in patients compared to healthy control (451 (176-850) vs 1150 (874-1521) pg/mL, p<0.05) but TNF-α production was higher (641 (609-841) vs 406 (201-841) pg/mL, p<0.05). The simultaneous incubation with LPS and simvastatin caused decreased IL-10 production in cells from patients compared to control (337 (135-626) vs 540 (345-871) pg/mL, p<0.05) and increased TNF-α release (711 (619-832) vs 324 (155-355) pg/mL, p<0.05). Comparison between subgroups showed that the results observed in TNF-α and IL-10 production by PBMC from critically ill patients was independent of AKI occurrence. CONCLUSIONS: The PBMC treatment with simvastatin resulted in attenuation on pro-inflammatory cytokine spontaneous production that was no longer observed when these cells were submitted to a second inflammatory stimulus. Our study shows an imbalance between pro and anti-inflammatory cytokine production in PBMC from critically ill patients regardless the presence of AKI.

Specific treatment of Prader-Willi syndrome through cyclical rehabilitation programmes.

PURPOSE: To evaluate retrospectively the efficiency of our rehabilitation programme for patients with Prader-Willi Syndrome. In total, 49 patients were examined, 21 female and 28 male, the youngest in their late teens. Prader-Willi syndrome is generally characterised by cognitive impairment, behavioural abnormalities, and hyperphagia. Patients are usually considerably adverse to any form of physical exercise, and despite hormonal therapy, weight control in adult patients can be difficult. METHODS: Four times a year, disease-specific residential programmes were organised, each lasting 4 weeks. The patients were restricted to a 1500 Kcal diet. In addition, they were required to do 6.5 h of physical exercise daily, stamina being built up by using music therapy, psychomotor therapy, education and entertainment activities. RESULTS: BMI decreased by 2.1 average points in every residential session. For three patients who attended our treatments regularly, a reduction of 8.9 points over 6 years was recorded. An attendance of at least three sessions per year seemed to be necessary to substantially reduce weight. CONCLUSIONS: A multidisciplinary approach and a daily calorie-counted diet can lead to significant weight loss in teenage and adult PWS patients. This approach would also be suitable in treating patients with other obesity syndromes with mental retardation.

Estratégias para melhorar a adesão do paciente - propostas para pacientes refratários / Strategies to improve patient compliance - proposals for refractory patients

Existe uma reconhecida dificuldade de adesão de uma parcela de pacientes em tratamento para transtornos decorrentes do uso de álcool e outras drogas. Objetivos: as práticas diárias aliada à sensibilidade dos profissionais induziram a busca por soluções no sentido de promover esta aderência. Metodologia: Assim, algumas estratégias para melhorar a adesão dos pacientes ao tratamento neste serviço foram elaboradas: a sala de orientação e o GAEP – Grupo de Apoio Estratégico ao Paciente. A sala de orientação recebe toda a demanda das pessoas que procuram o serviço pela primeira vez, como também dos pacientes já matriculados em variadas situações. Desta forma é possível oferecer imediatamente a escuta diferenciada e o melhor encaminhamento para cada caso. O GAEP recebe os pacientes refratários e cronificados, e, através de abordagem diretiva e focada na aderência, avalia as necessidades específicas de cada paciente. Resultados: A taxa de abandono precoce diminuiu de 40% para 19 % entre 2005 e 2010. Os pacientes crônicos, com dificuldades de adesão ao tratamento passaram a aderir em 48%. Conclusão: O trabalho em equipe multiprofissional é valorizado neste artigo, pois permite recriar metodologias de atendimento de acordo com as peculiaridades da população atendida