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INTRODUCTION: This systematic review examined the effect of neutralizing agents on bond strength after irrigation with sodium hypochlorite and their existing protocols in literature. METHODS: This present study adhered to the PRISMA guidelines and was registered at PROSPERO. Five electronic databases were searched (sept-2020/jan-2021) in English, Spanish, and Portuguese, without any restrictions on publication date. Cases reports, editorials and literature reviews were not included. The risk of bias was assessed using the Cochrane Collaboration tool. From the initial 7,147 studies, 2,745 were removed as duplicates and 4,382 were excluded after a title/abstract screen. RESULTS: Seventeen in vitro studies were included. The results showed that the higher the concentration of sodium hypochlorite, the lower the bond strength at dentine/restoration interface (p⟨0.01). Among the studies, sodium ascorbate was the most widely used neutralizer and showed the most significant results in increasing bond strength (p⟨0.01). The bond strength values were found to increase with longer application time of the neutralizing substances (p⟨0.01). CONCLUSIONS: The use of sodium ascorbate as a neutralizing agent can reverse the negative effects of the sodium hypochlorite and improve the bond strength between dentine and resin cement, however, it isn't possible to determine the best protocol for use.
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Recubrimiento Dental Adhesivo , Hipoclorito de Sodio/química , Hipoclorito de Sodio/farmacología , Cementos de Resina/química , Ácido Ascórbico/química , Ácido Ascórbico/farmacología , Dentina , Ensayo de MaterialesRESUMEN
Ammoniacal thiosulfate has been used lately as an alternative lixiviant for leaching gold from sulfides ores which are not amenable for cyanidation. However, the oxidation of the sulfide minerals generates products that inhibit the dissolution of gold and can promote the degradation of the leaching solution. The complexity of the ammoniacal thiosulfate leaching system has prevented the unification and clarification of the mechanisms of oxidation of sulfide ores used for gold extraction. In this study, a method combining polarization curves, Electrochemical impedance spectroscopy (EIS), and in situ Raman spectroscopy was implemented to investigate the oxidation process of high-purity pyrite. Pyrite samples were dispersed in carbon paste electrode (CPE-Py). The polarization curves of CPE-Py exhibited an increase in current values for overpotentials greater than 0.1 V, indicating the initiation of mineral oxidation processes. Subsequently, a maximum current was observed initially, followed by subsequent decrease, indicating the occurrence of passivation processes on the electrode surface. Hydrodynamic polarization curves demonstrated that the overpotential at which the passivation process occurs is independent of mass transport, suggesting that the passivation products were formed through solid-state transformation. Impedance spectra revealed that at overpotentials below 0.1 V, a partially resolved capacitive semicircle was observed, which was associated with the resistance encountered when charge was transferred between the solution and the surface layer interface. This resistance decreased as the polarization overpotential increased, implying a decrease in charge transfer kinetics. At higher overpotentials (0.3 V-0.4 V), a second capacitive semicircle appeared, linked to the oxidation of one or several species present in the mineral. In situ Raman spectroscopy was utilized to identify the oxidation species of pyrite in ammonia-thiosulfate ((NH4)2S2O3) leaching solution at a pH = 10.2. The composition of the species varied depending on the applied anodic potential. At low anodic potentials (0.1 V), Fe(OH)2 and thiosulfate (S2O32-) were formed, while at high anodic potentials (0.4 V), iron products such as Fe3O4 and γ-FeOOH, as well as sulfide species including thiosulfate, tetrathionates and sulfates (S2O32-, S4O6-2 and SO42-) were formed.
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Ethylmalonic encephalopathy (EE) is a severe inherited metabolic disorder that causes tissue accumulation of hydrogen sulfide (sulfide) and thiosulfate in patients. Although symptoms are predominantly neurological, chronic hemorrhagic diarrhea associated with intestinal mucosa abnormalities is also commonly observed. Considering that the pathophysiology of intestinal alterations in EE is virtually unknown and that sulfide and thiosulfate are highly reactive molecules, the effects of these metabolites were investigated on bioenergetic production and transfer in the intestine of rats. We observed that sulfide reduced NADH- and FADH2-linked mitochondrial respiration in the intestine, which was avoided by reduced glutathione (GSH) but not by melatonin. Thiosulfate did not change respiration. Moreover, both metabolites markedly reduced the activity of total, cytosolic and mitochondrial isoforms of creatine kinase (CK) in rat intestine. Noteworthy, the addition of GSH but not melatonin, apocynin, and Trolox (hydrosoluble vitamin E) prevented the change in the activities of total CK and its isoforms caused by sulfide and thiosulfate, suggesting a direct protein modification on CK structure by these metabolites. Sulfide further increased thiol content in the intestine, suggesting a modulation in the redox state of these groups. Finally, sulfide and thiosulfate decreased the viability of Caco-2 intestinal cells. Our data suggest that bioenergetic impairment caused by sulfide and thiosulfate is a mechanism involved in the gastrointestinal abnormalities found in EE.
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Sulfuro de Hidrógeno , Humanos , Ratas , Animales , Ratas Wistar , Tiosulfatos/farmacología , Células CACO-2 , Metabolismo Energético , Sulfuros , Intestinos , Diarrea , Isoformas de Proteínas/metabolismoRESUMEN
Sexual reversal methods are commonly used in plant breeding programs, allowing male flowers from female plants or vice versa. This work evaluated sexual reversal methods in female Cannabis plants and their effect on gas exchange activity. Plants treated with 1, methyl-cyclopropene (1-MCP), and aminoetoxyvinylglycine (AVG) showed differences in net photosynthesis (A) and stomatal conductance (gs) between the periods before and after sexual reversal treatments. Quantum yield (Qy), electron transport rate (ETR), and non-photochemical quenching (NPQ) did not show a relationship to the treatments, an increase in Qy and ETR, and a reduction in NPQ were observed after applying treatments. 1-MCP, AVG, and STS (silver thiosulfate) were effective in sexual reversal, while photoperiod changes did not induce the formation of male flowers. Induction of sexual reversion in Cannabis plants did not generate variations in energy dissipation mechanisms through photosystems.
Los métodos de reversión sexual se utilizan comúnmente en los programas de fitomejoramiento, permitiendo la formación de flores masculinas a partir de plantas femeninas y viceversa. Este trabajo tuvo como objetivo evaluar métodos de reversión sexual en plantas femeninas de Cannabis y su efecto sobre el intercambio de gases. Plantas tratadas con 1-metil-ciclopropano (1-MCP) y aminoetoxivinilglicina (AVG) mostraron diferencias en fotosíntesis neta (A) y conductancia estomática (gs) entre los periodos antes y después de los tratamientos de reversión sexual. El rendimiento cuántico (Qy), la tasa de transporte de electrones (ETR) y la disipación no fotoquímica (NPQ) no mostraron relación con los tratamientos, se observó un incremento en Qy y ETR y una reducción en NPQ después de la aplicación de los tratamientos. 1-MCP, AVG y STS (tiosulfato de plata) fueron efectivos en la reversión sexual, mientras que los cambios en el fotoperiodo no indujeron la formación de flores masculinas. La inducción de la reversión sexual en plantas de Cannabis no generó variaciones en los mecanismos que disipan la energía a través de los fotosistemas.
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Fotosíntesis , Cannabis/crecimiento & desarrollo , Procedimientos de Reasignación de Sexo/métodos , Cannabis/metabolismo , Gases/metabolismoRESUMEN
PURPOSE: This study aimed to investigate the effects of AGE on microvascular reactivity, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in older individuals at high risk for cardiovascular disease (CVD). Urinary thiosulfate was also investigated as an indirect marker of endogenous hydrogen sulfide (H2S) synthesis. The study was conducted in a randomized, double-blind, crossover, and placebo-controlled way. METHODS: Twenty-eight participants (14 male), 67 ± 6 years old with CVD risk factors, ingested 2.4 g of AGE or placebo (PLA). Near-infrared spectroscopy evaluated tissue oxygen saturation (StO2) during a vascular occlusion test (30 s baseline, 5 min occlusion, and 2 min reperfusion). The upslope of StO2 signal after cuff release was calculated to measure microvascular reactivity. Urinary thiosulfate levels were measured using a high-performance liquid chromatography system. RESULTS: The upslope of StO2 was significantly faster after AGE (1.01 ± 0.37% s-1) intake compared to PLA (0.83 ± 0.35% s-1; P < 0.001; d = 0.50). Relative changes in Δ% SBP from pre- to post-AGE intake (- 5.17 ± 5.77%) was significantly different compared to Δ% PLA (0.32 ± 5.99%; P = 0.001; d = 0.93). No significant changes in urinary thiosulfate concentrations were observed between interventions. Moreover, no significant gender effect in any parameter assessed was found. CONCLUSION: This study demonstrated that a single dose of AGE improved microvascular reactivity in older adults at risk of CVD despite such an effect was not linked with urinary thiosulfate levels. This trial was registered at clinicaltrials.gov as NCT04008693 (May 19, 2020).
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Enfermedades Cardiovasculares , Ajo , Sulfuro de Hidrógeno , Anciano , Enfermedades Cardiovasculares/prevención & control , Humanos , Sulfuro de Hidrógeno/metabolismo , Masculino , Microcirculación/fisiología , Persona de Mediana Edad , Músculo Esquelético/metabolismo , Consumo de Oxígeno/fisiología , Extractos Vegetales/metabolismo , Poliésteres/metabolismo , Tiosulfatos/metabolismoRESUMEN
The present work is related to the treatment of crushed waste of printed circuit boards (WPCBs) from electrical and electronic devices (WEEE), carrying out the recovery of copper in solution. In the first stage, the studied material was characterized by AAS, SEM-EDS, and XRD. The results revealed significantly high amounts of copper (744.42 mg/g), compared with the rest of the metals present in the sample, mainly iron and zinc. In the second stage of the work, alkali dynamic leaching experiments were carried out in the S2O3−2− O2 medium, evaluating important kinetic variables in order to verify the controlling step of the system and adjust the data to a kinetic model. According to the results obtained from the various experimental tests executed, it was found that in the studied system of S2O3−2− O2, the leaching of copper was preferably adjusted to the model of spherical particles with a shrinking core finding a mixed chemical−diffusive control, with values of Ea = 25.78 kJ/mol and n = 0.22 (for the leaching reagent), indicating that the reaction was controlled by the oxygen transport to the solid−liquid interface and also by the chemical reaction in the surface of particles, obtaining up to 99.82% copper in solution.
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Introduction: Our study evaluated the impact of sodium thiosulfate (ST) irrigation, subsequent to sodium hypochlorite (NaOCl) and just before root canal filling, on the filling quality (interfacial adaptation and penetration segment) of an epoxy resin-based root canal sealer. Methods and Materials: Twenty single-rooted human teeth were prepared with the ProTaper system. The specimens were then divided into the following groups: 5.25% NaOCl irrigation (NaOCl group) and 5.25% NaOCl irrigation+0.5% sodium thiosulfate (NaOCl+ST group). The root canals were filled using single-cone technique with ProTaper F3 cones and AH-Plus sealer, labeled with rhodamine B dye to allow analysis under a confocal laser scanning microscopy (CLSM). All samples were sectioned at 2, 4, and 6 mm from the apex and prepared for CLSM analysis. The percentage of voids, gaps and dentinal sealer penetration segment of the canal were calculated at the apical, middle and coronal thirds. The non-parametric Mann-Whitney statistical test was used at 5% significance level. Results: Higher percentage of gaps and voids were observed at all root thirds of the NaOCl group when compared to the NaOCl+ST group (P<0.05). There was a significant increase in the penetration segment of NaOCl+ST group at the coronal and middle root third when compared to the NaOCl group (P<0.05). Conclusion: Our in vitro results showed that the use of ST as an antioxidant agent after NaOCl irrigation promoted a better interfacial adaptation and penetration of epoxy resin-based root canal fillings.
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The pathogen Xylella fastidiosa belongs to the Xanthomonadaceae family, a large group of Gram-negative bacteria that cause diseases in many economically important crops. A predicted gene, annotated as glutaredoxin-like protein (glp), was found to be highly conserved among the genomes of different genera within this family and highly expressed in X. fastidiosa. Analysis of the GLP protein sequences revealed three protein domains: one similar to monothiol glutaredoxins (Grx), an Fe-S cluster and a thiosulfate sulfurtransferase/rhodanese domain (Tst/Rho), which is generally involved in sulfur metabolism and cyanide detoxification. To characterize the biochemical properties of GLP, we expressed and purified the X. fastidiosa recombinant GLP enzyme. Grx activity and Fe-S cluster formation were not observed, while an evaluation of Tst/Rho enzymatic activity revealed that GLP can detoxify cyanide and transfer inorganic sulfur to acceptor molecules in vitro. The biological activity of GLP relies on the cysteine residues in the Grx and Tst/Rho domains (Cys33 and Cys266, respectively), and structural analysis showed that GLP and GLPC266S were able to form high molecular weight oligomers (> 600 kDa), while replacement of Cys33 with Ser destabilized the quaternary structure. In vivo heterologous enzyme expression experiments in Escherichia coli revealed that GLP can protect bacteria against high concentrations of cyanide and hydrogen peroxide. Finally, phylogenetic analysis showed that homologous glp genes are distributed across Gram-negative bacterial families with conservation of the N- to C-domain order. However, no eukaryotic organism contains this enzyme. Altogether, these results suggest that GLP is an important enzyme with cyanide-decomposing and sulfurtransferase functions in bacteria, whose presence in eukaryotes we could not observe, representing a promising biological target for new pharmaceuticals.
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Cianuros/metabolismo , Glutarredoxinas/metabolismo , Estrés Oxidativo , Sulfurtransferasas/metabolismo , Xylella/enzimología , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Glutarredoxinas/genética , Modelos Moleculares , Filogenia , Conformación Proteica , Sulfurtransferasas/genética , Tiosulfato Azufretransferasa/metabolismoRESUMEN
Resumen La calcifilaxis es un síndrome caracterizado por la calcificación de la pared media de las arteriolas de pequeño y mediano calibre de dermis y tejido celular subcutáneo, que se caracteriza clínicamente por úlceras necróticas, intensamente dolorosas, que afectan sobre todo miembros inferiores. Existen factores de riesgo para su desarrollo, como insuficiencia renal crónica, hiperparatiroidismo, sexo femenino, raza caucásica, diabetes, uso de anticoagulantes, entre otros. Si bien no existe un protocolo estandarizado para su tratamiento, se ha propuesto el uso del tiosulfato sódico como primera elección. Se presenta el caso de una paciente de sexo femenino de 75 años de edad con diagnóstico de calcifilaxis.
Abstract Calciphylaxis is a syndrome characterized by calciphication of the media of small and medium vessels of dermis and subcutaneous celular tissue, clinically characterized by extremely painful, necrotic ulcers, that affects especially lower limbs. There are risk factors for its development, such as renal failure, hyperparathyroidism, female gender, caucasian race, diabetes, use of anticoagulants, among others. Although there is not a standarized protocol for the treatment, it has been proposed the use of sodium thiosulfate as first line. We report a case of a woman of 75 years old with calciphylaxis.
RESUMEN
Abstract Introduction: Calciphylaxis is an infrequent disease that almost exclusively affects patients with chronic kidney disease, although cases have been observed in patients without renal function impairment. The diagnosis is mainly made by clinical manifestations and subsequently confirmed by radiological and histological study. The optimal treatment is not known, although there is a consensus that a multifactorial approach is required. Clinical Case: A 68-year-old woman on hemodialysis for 2 years, who presented a painful nodular lesion in the left thigh, a skin biopsy was performed resulting in a diagnosis of calciphylaxis. Treatment and Outcome: Treatment was started with intravenous sodium thiosulfate. Pamidronate is added intravenously, three months later, due to an unfavorable evolution. After 6 months of treatment, improvement in nodular lesions and healing of the ulcerated lesion was observed to be generally well tolerated treatment. Conclusion: The combined treatment of sodium thiosulfate, pamidronate and calcitomimetics has been effectiveand safe for the treatment of calciphylaxis, inducing complete remission.
Resumen: Introducción: La calcifilaxis es una enfermedad infrecuente que afecta casi exclusivamente a pacientes con insuficiencia renal, aunque se han observado casos en pacientes sin deterioro de la función renal. El diagnóstico es clínico confirmándose con estudio radiológico e histológico. No se conoce con exactitud el tratamiento óptimo, aunque hay consenso en que se requiere un abordaje multifactorial. Caso Clínico: Mujer de 68 años en hemodiálisis desde hace 2 años, que presenta una lesión nodular dolorosa en muslo izquierdo, resultando un diagnostico compatible con calcifilaxis, tras biopsia cutánea. Tratamiento y resultado: Inicia tratamiento con tiosulfato de sodio vía venosa. Tres meses más tarde y ante la evolución desfavorable, se añade al tratamiento pamidronato vía intravenosa. Tras 6 meses de tratamiento se observa mejoría de las lesiones nodulares y cicatrización de la lesión ulcerada, habiéndose experimentado buena tolerancia. Conclusión: El tratamiento combinado de tiosulfato de sodio, pamidronato y calcimiméticos ha resultado efectivo y seguro para el tratamiento de la calcifilaxis, induciendo su remisión completa.
Asunto(s)
Anciano , Femenino , Humanos , Tiosulfatos/administración & dosificación , Calcifilaxia/tratamiento farmacológico , Pamidronato/administración & dosificación , Fallo Renal Crónico/complicaciones , Calcifilaxia/etiología , Calcifilaxia/patología , Quelantes/administración & dosificación , Diálisis Renal/métodos , Resultado del Tratamiento , Quimioterapia Combinada , Administración Intravenosa , Fallo Renal Crónico/terapiaRESUMEN
Sulfite oxidase, molybdenum cofactor, and ETHE1 deficiencies are autosomal recessive disorders that affect the metabolism of sulfur-containing amino acids. Patients with these disorders present severe neurological dysfunction and basal ganglia abnormalities, accompanied by high levels of thiosulfate in biological fluids and tissues. Aiming to better elucidate the pathophysiology of basal ganglia damage in these disorders, we evaluated the in vivo effects of thiosulfate administration on bioenergetics, oxidative stress, and neural damage in rat striatum. The in vitro effect of thiosulfate on creatine kinase (CK) activity was also studied. In vivo findings showed that thiosulfate administration decreased the activities of CK and citrate synthase, and increased the activity of catalase 30 min after administration. Activities of other antioxidant enzymes, citric acid cycle, and respiratory chain complex enzymes, as well as glutathione concentrations and markers of neural damage, were not altered by thiosulfate 30 min or 7 days after its administration. Thiosulfate also decreased the activity of CK in vitro in striatum of rats, which was prevented by the thiol reducing agents dithiothreitol (DTT), the antioxidants glutathione (GSH), melatonin, trolox (hydrosoluble analogue of vitamin E), and lipoic acid. DTT and GSH further prevented thiosulfate-induced decrease of the activity of a purified CK in a medium devoid of biological samples. These data suggest that thiosulfate inhibits CK activity by altering critical sulfhydryl groups of this enzyme. It may be also presumed that bioenergetics impairment and ROS generation induced by thiosulfate are mechanisms underlying the neuropathophysiology of disorders in which this metabolite accumulates.
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Cuerpo Estriado/efectos de los fármacos , Creatina Quinasa/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/metabolismo , Glutatión/metabolismo , Tiosulfatos/farmacología , Análisis de Varianza , Animales , Catalasa/metabolismo , Ciclo del Ácido Cítrico/efectos de los fármacos , Complejo I de Transporte de Electrón/metabolismo , Glutamato Deshidrogenasa/metabolismo , Masculino , Oxidación-Reducción/efectos de los fármacos , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismoRESUMEN
INTRODUCTION: Calciphylaxis is an infrequent disease that almost exclusively affects patients with chronic kidney disease, although cases have been observed in patients without renal function impairment. The diagnosis is mainly made by clinical manifestations and subsequently confirmed by radiological and histological study. The optimal treatment is not known, although there is a consensus that a multifactorial approach is required. CLINICAL CASE: A 68-year-old woman on hemodialysis for 2 years, who presented a painful nodular lesion in the left thigh, a skin biopsy was performed resulting in a diagnosis of calciphylaxis. TREATMENT AND OUTCOME: Treatment was started with intravenous sodium thiosulfate. Pamidronate is added intravenously, three months later, due to an unfavorable evolution. After 6 months of treatment, improvement in nodular lesions and healing of the ulcerated lesion was observed to be generally well tolerated treatment. CONCLUSION: The combined treatment of sodium thiosulfate, pamidronate and calcitomimetics has been effectiveand safe for the treatment of calciphylaxis, inducing complete remission.
INTRODUCCIÓN: La calcifilaxis es una enfermedad infrecuente que afecta casi exclusivamente a pacientes con insuficiencia renal, aunque se han observado casos en pacientes sin deterioro de la función renal. El diagnóstico es clínico confirmándose con estudio radiológico e histológico. No se conoce con exactitud el tratamiento óptimo, aunque hay consenso en que se requiere un abordaje multifactorial. CASO CLÍNICO: Mujer de 68 años en hemodiálisis desde hace 2 años, que presenta una lesión nodular dolorosa en muslo izquierdo, resultando un diagnostico compatible con calcifilaxis, tras biopsia cutánea. TRATAMIENTO Y RESULTADO: Inicia tratamiento con tiosulfato de sodio vía venosa. Tres meses más tarde y ante la evolución desfavorable, se añade al tratamiento pamidronato vía intravenosa. Tras 6 meses de tratamiento se observa mejoría de las lesiones nodulares y cicatrización de la lesión ulcerada, habiéndose experimentado buena tolerancia. CONCLUSIÓN: El tratamiento combinado de tiosulfato de sodio, pamidronato y calcimiméticos ha resultado efectivo y seguro para el tratamiento de la calcifilaxis, induciendo su remisión completa.
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Calcifilaxia/tratamiento farmacológico , Fallo Renal Crónico/complicaciones , Pamidronato/administración & dosificación , Tiosulfatos/administración & dosificación , Administración Intravenosa , Anciano , Calcifilaxia/etiología , Calcifilaxia/patología , Quelantes/administración & dosificación , Quimioterapia Combinada , Femenino , Humanos , Fallo Renal Crónico/terapia , Diálisis Renal/métodos , Resultado del TratamientoRESUMEN
Calciphylaxis is vasculopathy characterized by ischemia and painful skin necrosis due to calcification and intimal fibroplasia of thrombosis of the panicular arterioles. It most frequently compromises patients with terminal chronic renal failure and has a high mortality rate. Biopsy of skin lesions is used as a diagnostic method. No specific laboratory findings have been recorded. Skin lesions usually begin in the extremities like a painful purplish mottling similar to "livedo reticularis". The natural evolution is to ulcers and bedsores. The first line of treatment involves the care of skin lesions and antibiotic therapy. Sodium thiosulfate is used as treatment due to its antioxidant activity and as a chelating. Two clinical cases are here reported.
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Calcifilaxia/diagnóstico , Fallo Renal Crónico/complicaciones , Adulto , Calcifilaxia/etiología , Calcifilaxia/terapia , Terapia Combinada , Desbridamiento , Femenino , Humanos , Persona de Mediana EdadRESUMEN
La calcifilaxis es una vasculopatía caracterizada por isquemia y necrosis cutánea dolorosa debida a calcificación, fibroplastia de la íntima y trombosis de las arteriolas paniculares. Compromete más frecuentemente a pacientes con insuficiencia renal crónica terminal y tiene muy elevada mortalidad. La biopsia de las lesiones cutáneas se utiliza como método diagnóstico. No se han registrado hallazgos específicos de laboratorio. Las lesiones cutáneas generalmente comienzan en las extremidades a modo de moteado violáceo doloroso similar al livedo reticularis. La evolución natural es hacia úlceras y escaras. La primera línea de tratamiento consiste en el cuidado de las lesiones cutáneas y antibioticoterapia. El tiosulfato sódico se utiliza como tratamiento debido a su actividad como antioxidante y quelante. Se presentan dos casos clínicos.
Calciphylaxis is vasculopathy characterized by ischemia and painful skin necrosis due to calcification and intimal fibroplasia of thrombosis of the panicular arterioles. It most frequently compromises patients with terminal chronic renal failure and has a high mortality rate. Biopsy of skin lesions is used as a diagnostic method. No specific laboratory findings have been recorded. Skin lesions usually begin in the extremities like a painful purplish mottling similar to "livedo reticularis". The natural evolution is to ulcers and bedsores. The first line of treatment involves the care of skin lesions and antibiotic therapy. Sodium thiosulfate is used as treatment due to its antioxidant activity and as a chelating. Two clinical cases are here reported.
Asunto(s)
Humanos , Femenino , Adulto , Persona de Mediana Edad , Calcifilaxia/diagnóstico , Fallo Renal Crónico/complicaciones , Calcifilaxia/etiología , Calcifilaxia/terapia , Terapia Combinada , DesbridamientoRESUMEN
Patients with sulfite oxidase (SO) deficiency present severe brain abnormalities, whose pathophysiology is not yet elucidated. We evaluated the effects of sulfite and thiosulfate, metabolites accumulated in SO deficiency, on creatine kinase (CK) activity, mitochondrial respiration and redox status in hippocampus, striatum and cerebellum of developing rats. Our in vitro results showed that sulfite and thiosulfate decreased CK activity, whereas sulfite also increased malondialdehyde (MDA) levels in all brain structures evaluated. Sulfite further diminished mitochondrial respiration and increased DCFH oxidation and hydrogen peroxide production in hippocampus. Sulfite-induced CK activity decrease was prevented by melatonin (MEL), resveratrol (RSV), and dithiothreitol while increase of MDA levels was prevented by MEL and RSV. Regarding the antioxidant system, sulfite increased glutathione concentrations in hippocampus and striatum. In addition, sulfite decreased the activities of glutathione peroxidase in all brain structures, of glutathione S-transferase in hippocampus and cerebellum, and of glutathione reductase in cerebellum. In vivo experiments performed with intrahippocampal administration of sulfite demonstrated that this metabolite increased superoxide dismutase activity without altering other biochemical parameters in rat hippocampus. Our data suggest that impairment of energy metabolism and redox status may be important pathomechanisms involved in brain damage observed in individuals with SO deficiency.
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Cerebelo/efectos de los fármacos , Cuerpo Estriado/efectos de los fármacos , Transferencia de Energía/efectos de los fármacos , Hipocampo/efectos de los fármacos , Sulfitos/farmacología , Animales , Creatina Quinasa/metabolismo , Relación Dosis-Respuesta a Droga , Fluoresceínas/metabolismo , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Glutatión Transferasa/metabolismo , Peróxido de Hidrógeno/metabolismo , Técnicas In Vitro , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Oxidación-Reducción/efectos de los fármacos , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismoRESUMEN
INTRODUCTION: The aim of this study was to evaluate the efficacy of sodium thiosulfate (Na2S2O3) for restoring adhesion to pulp chamber dentin treated with sodium hypochlorite (NaOCl) and EDTA. METHODS: Sixty-three crowns of bovine incisors were cut to expose the dentin pulp chamber. The specimens were polished and randomly distributed into 9 groups (n = 7) according to the following protocols used: 0.9% sodium chloride for 30 minutes (negative control), 5.25% NaOCl for 30 minutes, 17% EDTA for 3 minutes, and 5.25% NaOCl for 1 minute (positive control). The other groups, after treatments with NaOCl and EDTA, were immersed in 0.5% or 5% Na2S2O3 for 1, 5, and 10 minutes or just immersed in an inert solution for 10 minutes (0.9% sodium chloride). After drying the specimens, Scotchbond Multi-Purpose (3M ESPE, St Paul, MN) was applied to the pulp chamber dentin followed by Filtek Z250 composite (3M ESPE). Six rectangular slabs were obtained from each specimen, and the dentin/resin interface was tested by using a universal testing machine. The resulting data were submitted to 1-way analysis of variance and the Duncan test (P = .05). RESULTS: There was a significant decrease in bond strength regarding NaOCl and EDTA (P < .05). When 5% Na2S2O3 was used for 10 minutes, the bond strength was found to be statistically equal to the negative control and higher than the positive control (P < .05). CONCLUSIONS: The use of Na2S2O3 can significantly increase the bond strength of composite resin to NaOCl/EDTA-treated dentin, allowing adhesive restorations to be immediately applied after endodontic treatment.
Asunto(s)
Recubrimientos Dentinarios/uso terapéutico , Dentina/efectos de los fármacos , Hipoclorito de Sodio/efectos adversos , Tiosulfatos/uso terapéutico , Grabado Ácido Dental , Adhesivos/química , Animales , Antioxidantes/farmacología , Bovinos , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Cavidad Pulpar/diagnóstico por imagen , Cavidad Pulpar/efectos de los fármacos , Cavidad Pulpar/ultraestructura , Análisis del Estrés Dental , Dentina/diagnóstico por imagen , Dentina/ultraestructura , Recubrimientos Dentinarios/química , Recubrimientos Dentinarios/farmacología , Ácido Edético/administración & dosificación , Ácido Edético/efectos adversos , Incisivo/diagnóstico por imagen , Incisivo/efectos de los fármacos , Irrigantes del Conducto Radicular/farmacología , Hipoclorito de Sodio/administración & dosificación , Tiosulfatos/administración & dosificación , Tiosulfatos/farmacologíaRESUMEN
Sulfite oxidase (SOX) deficiency is an inherited neurometabolic disorder biochemically characterized by tissue accumulation and high urinary excretion of sulfite and thiosulfate. Affected patients present severe neurological dysfunction accompanied by seizures, whose pathophysiology is poorly known. In the present study we evaluated the in vitro effects of sulfite and thiosulfate on important parameters of glutamatergic neurotransmission and redox homeostasis in rat cerebral cortex slices. We verified that sulfite, but not thiosulfate, significantly decreased glutamate uptake when cerebral cortex slices were exposed during 1h to these metabolites. We also observed that thiosulfate inhibited glutamine synthetase (GS) activity. A pronounced trend toward GS inhibition induced by sulfite was also found. Regarding redox homeostasis, sulfite, at the concentration of 10 µM, increased thiobarbituric acid-reactive substances and decreased glutathione concentrations after 1h of exposure. In contrast, thiosulfate did not alter these parameters. We also found that 500 µM sulfite increased sulfhydryl group content in rat cerebral cortex slices and increased GSH levels in a medium containing oxidized GSH (GSSG) and devoid of cortical slices, suggesting that sulfite reacts with disulfide bonds to generate sulfhydryl groups. Moreover, sulfite and thiosulfate did not alter the activities of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST) and glucose-6-phosphate dehydrogenase (G6PDH) after 1h of incubation. However, sulfite inhibited the activities of GPx, GST and G6PDH when cortical slices were exposed for 3h to sulfite. We finally verified that sulfite did not induce cell death after 1h of incubation. Our data show that sulfite impairs glutamatergic neurotransmission and redox homeostasis in cerebral cortex. Therefore, it may be presumed that these pathomechanisms contribute, at least in part, to the seizures observed in patients affected by SOX deficiency.
Asunto(s)
Corteza Cerebral/efectos de los fármacos , Ácido Glutámico/metabolismo , Glutatión/metabolismo , Neurotransmisores/metabolismo , Sulfitos/farmacología , Animales , Relación Dosis-Respuesta a Droga , Glucosafosfato Deshidrogenasa/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Técnicas In Vitro , L-Lactato Deshidrogenasa/metabolismo , Estrés Oxidativo/efectos de los fármacos , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Tritio/metabolismoRESUMEN
BACKGROUND: Calciphylaxis is a rare and severe disease with an annual incidence of around 1 % in dialysis patients. The main study aim was to determine its incidence in Martinique, where there is a significant population of patients on dialysis. PATIENTS AND METHODS: All patients diagnosed with calciphylaxis between 2006 and 2012 and living in Martinique were included, retrospectively. Social, demographic, biological, anatomic, pathological, histological and outcome data were analysed. RESULTS: Fifteen patients were included (8 women, 7 men). The incidence of calciphylaxis in this population was about 4.62/1,000,000 inhabitants per year. All patients presented very painful skin ulcerations and necrosis, chiefly on the lower extremities in 53.3 % of cases. All patients were on haemodialysis and two had undergone renal transplantation. Fourteen of the 15 patients were presenting secondary hyperparathyroidism, 12 had hypertension, 9 peripheral arterial disease, 8 obesity and 8 diabetes mellitus. Raised calcium and phosphorus were noted in 8 patients, with hypoalbuminaemia in 9 patients. Treatment with sodium thiosulfate was given for 8 patients, and was beneficial for all after a mean duration of 3.4 months. After 6 months of follow-up, 8 of the 15 patients were cured, 1 showed improvement and 6 had died. CONCLUSION: To our knowledge, this is the first study to examine the incidence of calciphylaxis in the general population. The relatively large number of patients could be accounted for by the high number of comorbidities in end-stage renal disease patients in Martinique, including obesity, diabetes, hypertension and arteritis. Treatment with sodium thiosulfate was beneficial for 8 patients.
Asunto(s)
Calcifilaxia/epidemiología , Amputación Quirúrgica , Calcifilaxia/etiología , Calcifilaxia/terapia , Femenino , Humanos , Hiperparatiroidismo Secundario/complicaciones , Incidencia , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/cirugía , Fallo Renal Crónico/terapia , Trasplante de Riñón , Úlcera de la Pierna/etiología , Masculino , Martinica/epidemiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Pronóstico , Diálisis Renal , Estudios Retrospectivos , Tiosulfatos/uso terapéuticoRESUMEN
PURPOSE: To determine the percentage of tumoral necrosis and volume after cyanogenic chemotherapy. METHODS: Histopathological findings of 20 Swiss mice inoculated subcutaneously in the left abdominal wall with 0.05 ml of cell suspension containing 2.5 x 105 viable cells of the Ehrlich tumor were evaluated. The tumor response to cyanogenic chemotherapy was determined using a system that comprises two inhibition factors of tumor growth by calculating the percentage of necrosis in the tumor tissue and calculation of tumor volume in treated animals relative to that in control animals. The importance of this system has been validated by the correlation between tumor inhibition in the groups treated with the respective percentages of necrosis. RESULTS: While the control group presented an average of 13.48 ± 14.71% necrosis and average tumor volume of 16.18 ± 10.94, the treated group had an average of 42.02 ± 11.58 and 6.8 ± 3.57, respectively. The tumor inhibition was significantly associated with treatment (p=0.0189). The analysis of necrosis percentage showed a significant prognostic importance (p=0.0001). CONCLUSION: It is concluded that the effect of cyanogenic chemotherapy showed strong inhibitory action of tumor growth, as well as an increase in its area of necrosis.(AU)
Asunto(s)
Animales , Necrosis/patología , Neoplasias/patología , Quimioterapia , HidrógenoRESUMEN
PURPOSE: To determine the percentage of tumoral necrosis and volume after cyanogenic chemotherapy. METHODS: Histopathological findings of 20 Swiss mice inoculated subcutaneously in the left abdominal wall with 0.05 ml of cell suspension containing 2.5 x 105 viable cells of the Ehrlich tumor were evaluated. The tumor response to cyanogenic chemotherapy was determined using a system that comprises two inhibition factors of tumor growth by calculating the percentage of necrosis in the tumor tissue and calculation of tumor volume in treated animals relative to that in control animals. The importance of this system has been validated by the correlation between tumor inhibition in the groups treated with the respective percentages of necrosis. RESULTS: While the control group presented an average of 13.48 ± 14.71% necrosis and average tumor volume of 16.18 ± 10.94, the treated group had an average of 42.02 ± 11.58 and 6.8 ± 3.57, respectively. The tumor inhibition was significantly associated with treatment (p=0.0189). The analysis of necrosis percentage showed a significant prognostic importance (p=0.0001). CONCLUSION: It is concluded that the effect of cyanogenic chemotherapy showed strong inhibitory action of tumor growth, as well as an increase in its area of necrosis. .