Long-term efficacy of percutaneous tibial nerve stimulation for faecal incontinence and a new approach for partial responders.

BACKGROUND: The aim of the present study was to evaluate the long-term efficacy of percutaneous tibial nerve stimulation (PTNS) for patients with faecal incontinence (FI) refractory to conservative treatment. Secondary aims were to identify predictors of response and validate new treatment pathways for partial responders. METHODS: A prospective, interventional study was carried out in a specialist defecatory disorder unit from a university hospital between January 2010 and June 2017 on patients > 18 years old with FI refractory to conservative treatment. Thirty-minute PTNS sessions were performed in three phases (weekly, biweekly and monthly) up to a year, with clinical reassessment at 3, 6, 12 and 36 months. Patients were classified as optimal responders when their pretreatment Wexner score decreased > 50%; partial responders when it decreased 25-50%; and insufficient responders if it decreased < 25%. Only optimal and partial responders progressed into successive phases. RESULTS: Between 2010 and 2017, 139 patients (110 women, median age 63 years [range 22-82 years]) were recruited. After the first phase, 4 patients were optimal responders, 93 were partial responders and 36 were insufficient responders. At 6 and 12 months, 66 and 89 patients respectively were optimal responders, with an optimal response rate of 64% at the end of treatment. A total of 93.3% patients with a partial response initially finally became optimal responders. Furthermore, at 36 months, 71.9% of patients were still optimal responders without supplementary treatment, although their quality of life did not improve significantly. Baseline Wexner scores ≤ 10 and symptom duration < 1 year were identified as predictive factors for positive responses to PTNS. CONCLUSIONS: Patients undergoing PTNS for 1 year following this protocol had optimal long-term responses. PTNS sessions for up to 1 year in patients who were partial responders prevents a high percentage of them from needing more invasive treatments, and maintains long-term continence in patients who were optimal responders.

Solución de St Marks como alternativa al manejo de la hiponatremia en la fístula ileal / St Marks solution as an alternative to the management of hyponatremia in ileal fistula

Las fístulas, especialmente las de alto débito, frecuentemente precisan hidratación y reposición electrolítica agresiva, destacando las pérdidas de sodio como principal complicación hidroelectrolítica.Varón de 53 años intervenido en julio de 2017 y que en noviembre 2018 ingresó para reconstrucción del tránsito intestinal. Tras varias intervenciones quirúrgicas apareció una fístula pioestercoracea de alto débito a nivel de íleo. El manejo de la fístula fue conservador con nutrición parenteral total individualizada lográndose balance hidroelectrolítico óptimo. Posteriormente el paciente perdió tanto el acceso venoso central como los periféricos, siendo imposible la canalización de una vía periférica en varios días. Durante este periodo el paciente desarrolló una hiponatremia severa que desde el servicio de Farmacia fue abordada por la vía oral con una solución de hidratación específica, como la solución de St Marks, que se caracteriza por su alto contenido en sodio y bajo en potasio para evitar hiperpotasemias que pueden dar lugar en estos pacientes. Con el tratamiento instaurado se logró recuperar las cifras de natremia evitando complicaciones neurológicas hasta que finalmente se canalizó una vía periférica. En nuestro paciente esta solución resultó ser efectiva logrando remontar drásticamente las cifras de natremia cercana a valores normales. Así pues, la solución de St Marks puede ser una alternativa a la vía intravenosa cuando no esté disponible o ser incluso complementaria a ésta. (AU)

Fistulas, especially those with high output, frequently require hydration and aggressive electrolyte replacement, highlighting sodium losses as the main hydroelectrolytic complication.53-year-old man who underwent surgery in July 2017 and who was admitted in November 2018 for intestinal transit reconstruction. After several surgical interventions, a high-output piostercoraceous fistula appeared at the ileus level. Management of the fistula was conservative with individualized total parenteral nutrition, achieving optimal fluid and electrolyte balance. Subsequently, the patient lost both the central and peripheral venous access, being several days without vascular access. During this period, the patient developed severe hyponatremia that the Pharmacy service treated orally with a specific hydration solution, St Marks’s solution, which is characterized by its high sodium and low potassium content to avoid hyperkalemias that can give rise in these patients. With the established treatment, it was possible to recover the levels of natraemia avoiding neurological complications until finally peripheral venous catheterization was placed. In our patient, this solution turned out to be effective, managing to drastically raise the levels of natraemia close to normal values. Thus, the St Marks solution can be an alternative to the intravenous access when it is not available or even be complementary to it. (AU)

Vólvulo de ciego y colon derecho: una causa infrecuente de obstrucción intestinal / Cecal and right colon volvulus: a infrequent cause of intestinal obstruction

El vólvulo de ciego es infrecuente en Occidente y representa únicamente el 1% de los casos de oclusión intestinal en el adulto. Los pacientes con esta entidad presentan habitualmente un cuadro clínico de dolor abdominal intermitente, vómitos y ausencia de gases y heces por el recto. Presentamos el caso de un paciente intervenido quirúrgicamente por un cuadro oclusivo originado por un vólvulo de ciego y todo colon ascendente con compromiso vascular. El objetivo de presentar este caso clínico es describir las características de esta inusual patología, analizar las causas y exponer las estrategias de tratamiento

The cecal volvulus is common in the West and represents only 1% of cases of intestinal obstruction in adults. Usually patients suffering from this condition present a clinical chart of intermittent abdominal pain, vomits and non-excretion of feces from the rectum. We report the case of a patient who underwent surgery due to an occlusive syndrome is presented, where a volvulus of cecum and right colon with vascular this unusual pathology, analyze the causes and exposing treatment strategies

Oxidative stress, progressive damage in the substantia nigra and plasma dopamine oxidation, in rats chronically exposed to ozone.

The purpose of our work was to determine the effects of oxidative stress on the neurodegeneration process in the substantia nigra, and to evaluate dopamine-oxidation metabolites in the plasma using a cyclic voltammetry (CV) technique. We have also studied the correlation between the increases in oxidized dopamine-species levels with the severity of lipid-peroxidation in the plasma. Sixty-four male Wistar rats were divided into four experimental groups and received air (Group I, control) or ozone (0.25 ppm) daily by inhalation for 4h for 15 (Group II), 30 (Group III), and 60 (Group IV) days. The brains were processed for immunohistochemical location of dopamine and p53 in the substantia nigra. Plasma collected from these animals was assayed for oxidized dopamine products using CV and lipid-peroxidation levels were measured. Our results indicate that chronic exposure to low O(3) doses causes that the number of dopaminergic neurons decreased, and p53-immunoreactive cells increases until 30 days; which was a function of the time of exposure to ozone. Oxidative stress produces a significant increase in the levels of the dopamine quinones (DAQs) that correlated well (r=0.962) with lipid peroxides in the plasma during the study period. These results suggest that DAQ could be a reliable, peripheral oxidative indicator of nigral dopaminergic damage in the brain.

Density Functional Study of 2-[(R-Phenyl)amine]-1,4-naphthalenediones.

The molecular and electronic structures of a series of 2-[(R-phenyl)amine]-1,4-naphthalenediones (R = m-Me, p-Me, m-Et, p-CF3, p-Hex, p-Et, m-F, m-Cl, p-OMe, p-COMe, p-Bu, m-COOH, p-Cl, p-COOH, p-Br, m-NO2, m-CN, and p-NO2) and their anions are investigated in the framework of density functional theory. The calculations are of all-electron type using a double zeta valence polarization basis set optimized for density functional theory methods. The theoretical study shows that all compounds are nonplanar. The nonplanarity can be rationalized in terms of occupied π orbitals. A linear correlation between the measured half-wave potentials and the calculated gas-phase electron affinities is found. It holds for local as well as generalized gradient corrected functionals. Structural parameters, harmonic vibrational frequencies, and adiabatic and vertical electron affinities as well as orbital and spin density plots of the studied compounds are presented.

Relationship between molecular structure and electron targets in the electroreduction of benzocarbazolediones and anilinenaphthoquinones. Experimental and theoretical study.

We report the synthesis and voltamperometric reduction of 5H-benzo[b]carbazole-6,11-dione (BCD) and its 2-R-substituted derivatives (R = -OMe, -Me, -COMe, -CF(3)). The electrochemical behavior of BCDs was compared to that of the 2-[(R-phenyl)amine]-1,4-naphthalenediones (PANs) previously studied. Like PANs, BCDs exhibit two reduction waves in acetonitrile. The first reduction step for the BCDs represents formation of the radical anion, and the half-wave potential (E(1/2)) values for this step are less negative than for that of the PANs. The second reduction wave, corresponding to the formation of dianion hydroquinone, has E(1/2) values that shift to more negative potentials. A good linear Hammett-Zuman (E(1/2) vs sigma(p)) relationship, similar to that for the PAN series, was also obtained for the BCDs. However, unlike the PANs, in the BCDs, the first reduction wave was more susceptible to the effect of the substituent groups than was the second wave, suggesting that the ordering of the two successive one-electron reductions in BCDs is opposite that in PANs. This is explained by the fact that the electron delocalizations in the two systems are different; in the case of BCDs there is an extra aromatic indole ring, which resists loss of its aromatic character. The electronic structures of BCD compounds were, therefore, investigated within the framework of the density functional theory, using the B3LYP hybrid functional with a double zeta split valence basis set. Our theoretical calculations show that the O(1).H-N hydrogen bond, analogous to that previously described for the PAN series, is not observed in the BCDs. Laplacians of the critical points (nabla(2)rho) and the natural charges for the C-O bonds indicate that the first reduction wave for the BCDs corresponds to the C(4)-O(2) carbonyl, while in the PAN series the first one-electron transfer occurred at the C(1)-O(1) carbonyl. Natural bond orbital analysis showed that, in all the BCDs, the lowest unoccupied molecular orbital (LUMO) is located at C(4), whereas for the PANs, the LUMO is found at C(1). The good correlation between the LUMO energy values and the E(1/2) potentials (wave I) established that the first one-electron addition takes place at the LUMO. Analysis of the molecular geometry confirmed that, in both series of compounds, the effect of the substituent groups is mainly on the C(4)-O(2) carbonyl. These results explain the fact that reduction of the C(4)-O(2) carbonyl (voltammetric wave II in the PANs and voltammetric wave I in the BCDs) is more susceptible to the effect of the substituent groups than is reduction of the C(1)-O(1) carbonyl (wave I in the PANs and wave II in the BCDs).

Molecular structure of substituted phenylamine alpha-OMe- and alpha-OH-p-benzoquinone derivatives. Synthesis and correlation of spectroscopic, electrochemical, and theoretical parameters.

Thirteen C(6) para-substituted anilinebenzoquinones derived from perezone (PZ) (2-(1,5-dimethyl-4-hexenyl)-3-hydroxy-5-methyl-1,4-benzoquinone) were prepared to analyze the effect of the substituents on quinone electronic properties. The effect of a hydrogen bond between the alpha-hydroxy and carbonyl C(4)-O(4) groups was determined in perezone derivatives by substituting electron-donor and electron-acceptor groups such as -OMe, -Me, -Br, and -CN and comparing the -OH (APZs) and -OMe (APZms) derivatives. Reduction potentials of these compounds were measured using cyclic voltammetry in anhydrous acetonitrile. The typical behavior of quinones, with or without alpha-phenolic protons, in an aprotic medium was not observed for APZs due to the presence of coupled, self-protonation reactions. The self-protonation process gives rise to an initial wave, corresponding to the irreversible reduction reaction of quinone (HQ) to hydroquinone (HQH(2)), and to a second electron transfer, attributed to the reversible reduction of perezonate (Q(-)) formed during the self-protonation process. This reaction is favored by the acidity of the alpha-OH located at the quinone ring. To control the coupled chemical reaction, we considered both methylation of the -OH group (APZms) and addition of a strong base, tetramethylammonium phenolate (Me(4)N(+)C(6)H(5)O(-)), to completely deprotonate the APZs. Methylation led to recovery of reversible, bi-electronic behavior (Q/Q(*)(-) and Q(*)(-)/Q(2)(-)), indicating the nonacidic properties of the NH group. The addition of a strong base resulted in reduction of perezonate (Q(-)) obtained from the acid-base reaction of APZs with Me(4)N(+)C(6)H(5)O(-) to produce the dianion radical (Q(*)(2)(-)). Although the nitrogen atom interferes with direct conjugation between both rings by binding the quinone with the para-substituted ring, the UV-vis spectra of these compounds showed the existence of intramolecular electronic transfer from the respective aniline to the quinone moiety. (13)C NMR chemical shifts of the quinone atoms provided additional evidence for this electron transfer. These findings were also supported by linear variation in cathodic peak potentials (E(pc)) vs Hammett sigma(p) constants associated with the different electrochemical transformations: Q/Q(*)(-), Q(*)(-)/Q(2)(-) for APZms or HQ/HQH(2) and Q(-)/Q(*)(2)(-) for APZs. The electronic properties of model anilinebenzoquinones were determined at a B3LYP/6-31G(d,p) level of theory within the framework of the density functional theory. Our theoretical calculations predicted that all the compounds are floppy molecules with a low rotational C-N barrier, in which the degree of conjugation of the lone nitrogen pair with the quinone system depends on the magnitude of the electronic effect of the substituents of the aniline ring. Natural charges show that C(1) is more positive than C(4) although the LUMO orbital is located at C(4). Hence, if the natural charge distribution in the molecule controls the first electron addition, this should occur at carbon atom C(1). If the process is controlled by the LUMO orbitals, however, electron addition would first occur at C(4). For the APZms series susceptibility of the first reduction wave to the substitution effect (rho(pi) = 147 mV) is lower than that of the second reduction wave (rho(pi) = 156 mV). Thus, the first, one-electron transfer in the quinone system is controlled by the natural charge distribution of the molecule and therefore takes place at C(1).

An Experimental and Theoretical Study of the Substituent Effects on the Redox Properties of 2-[(R-phenyl)amine]-1,4-naphthalenediones in Acetonitrile.

We synthesized and analyzed 19 compounds of 3'- (meta-) and 4'- (para-) substituted 2-[(R-phenyl)amine]-1,4-naphthalenediones (PANs) R = p-MeO, p-Me, p-Bu, p-Hex, p-Et, m-Me, m-Et, H, p-Cl, p-Br, m-F, m-Cl, p-COCH(3), m-CN, m-NO(2), m-COOH, and p-COOH. Despite the fact that the nitrogen atom, which binds the quinone with the meta- and para-substituted ring, interferes with the direct conjugation between both rings, the UV-vis spectra of these compounds show the existence of an intramolecular electronic transfer from the respective aniline to the p-naphthoquinone moiety. In accordance with this donor-acceptor character, the cyclic voltammograms of these compounds exhibit two, one-electron reduction waves corresponding to the formation of radical-anion and dianion, where the half-wave potential values vary linearly with the Hammett constants (sigma(x)). The analysis of the different voltammetric parameters (e.g., voltammetric function, anodic/cathodic peak currents ratio, and the separation between the anodic and cathodic potential peaks) show that with the exception of the carboxylic PAN derivatives, all compounds present the same reduction pathway. We investigated the molecular and electronic structures of these compounds using the semiempirical PM3 method and, within the framework of the Density Functional Theory, using the Becke 3LYP hybrid functional with a double zeta split valence basis set. Our theoretical calculations predict that, with the exception of the p-nitro compound, all the compounds are planar molecules where the conjugation degree of the nitrogen lone pair with the quinone system depends on the position and magnitude of the electronic effect of the substituent in the aniline ring. The Laplacians of the critical points (nabla(2)rho), for the C-O bonds, show that the first reduction wave corresponds to the carbonyl group in alpha-position to the aniline, and that the second one-electron transfer is due to the C(4)-O(2) carbonyl reduction. Thus, the higher reaction constant value (rho) obtained for the second one-electron transfer is due to the fact that the displacement of the nonshared electrons of the amino nitrogen merely modifies the electron density of C(4)-O(2) bond. The positive correlation between the LUMO energy values calculated for these compounds and the E(1/2) potentials corresponding to the C(1)-O(1) carbonyl reduction show that the electron addition takes place at the lowest unoccupied molecular orbital, supporting the fact that this wave is also prone to the substituent effect.

2,5-Diamino-p-benzoquinone Derivatives as Photosystem I Electron Acceptors: Synthesis and Electrochemical and Physicochemical Properties.

A series of 2,5-diamino-p-benzoquinone derivatives have been prepared and their physicochemical properties studied. The sensitivity of their photoreduction potential to 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, and KCN, as well as the photosystem I (PSI) activity, suggests that the reduction of 2,5-diamino-p-benzoquinone derivatives in the illuminated thylakoid is at the primary electron acceptor of PSI and it is reversible. The half-wave potentials of these compounds to their corresponding radical anions in an aprotic medium such as acetonitrile were found to be comparable with the midpoint potential values of the electron transport carriers at the reducing site of PSI. The strong reductant produced by PSI is really more accessible to the strong lipophilic electron acceptor. These lipophilic p-benzoquinone derivatives can reach the carriers inside the thylakoid membrane more easily than the ionic electron acceptor. The accepting electron properties of these compounds at PSI are similar to those of the bipyridinium herbicides.

Inhibition of oxygen evolution by zaluzanin C.

The inhibition of ATP synthesis, proton uptake, and electron transport (basal, phosphorylating, and uncoupled) from water to methylviologen by zaluzanin C indicates that it acts as an electron transport inhibitor. Uncoupled photosystem I electron transport rate was not affected by zaluzanin C; however, uncoupled photosystem II electron flow from water to 2,3,5,6-tetramethyl phenylenediamine and from water to silicomolybdate was inhibited, but electron transport from diphenylcarbazide to silicomolybdate was not affected. We conclude that the site of inhibition by zaluzanin C is located at the oxygen evolution level.